diff --git a/.config/nextest.toml b/.config/nextest.toml
new file mode 100644
index 000000000..2a4cd2cb9
--- /dev/null
+++ b/.config/nextest.toml
@@ -0,0 +1,3 @@
+# Minimum cargo-nextest for this repository: GHSA-vc25-qg58-w57c is fixed in 0.9.150 and CI
+# installs exactly that version, so an older nextest refuses to run (exit 92 REQUIRED_VERSION_NOT_MET).
+nextest-version = "0.9.150"
diff --git a/.github/workflows/packaging-lint.yml b/.github/workflows/packaging-lint.yml
index 1353830f8..b903f82ea 100644
--- a/.github/workflows/packaging-lint.yml
+++ b/.github/workflows/packaging-lint.yml
@@ -22,3 +22,27 @@ jobs:
   lint:
     # Intentionally tracked at @main (not SHA-pinned) so org-wide CI improvements, security fixes, and build optimizations propagate without PR churn across all craftapp repos.
     uses: storytold/craft-common-actions/.github/workflows/packaging-lint.yml@main
+
+  windows-install-policy:
+    timeout-minutes: 10
+    name: Windows installation policy (no app build)
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - name: Install the pinned packaging toolchain
+        shell: pwsh
+        run: |
+          $tools = Join-Path $env:RUNNER_TEMP 'craft-install-policy-wix'
+          dotnet tool install --tool-path $tools wix --version 5.0.2
+          if ($LASTEXITCODE -ne 0) { throw 'WiX installation failed.' }
+          $tools >> $env:GITHUB_PATH
+          $policy = Get-Content -Raw -LiteralPath packaging/windows/install-policy.json | ConvertFrom-Json
+          foreach ($extension in @($policy.extensions)) {
+            & (Join-Path $tools 'wix.exe') extension add -g "WixToolset.$extension.wixext/5.0.2"
+            if ($LASTEXITCODE -ne 0) { throw "WiX extension $extension installation failed." }
+          }
+      - name: Build and check non-executable installer fixtures
+        shell: pwsh
+        run: ./packaging/windows/test-install-policy.ps1 -OutputDirectory (Join-Path $env:RUNNER_TEMP 'craft-install-policy-tests')
diff --git a/.github/workflows/windows-arm64.yml b/.github/workflows/windows-arm64.yml
index a074e6dbe..4499e3fdc 100644
--- a/.github/workflows/windows-arm64.yml
+++ b/.github/workflows/windows-arm64.yml
@@ -28,8 +28,10 @@ permissions:
 
 jobs:
   windows-arm64:
-    # Intentionally tracked at @main (not SHA-pinned) so org-wide CI improvements, security fixes, and build optimizations propagate without PR churn across all craftapp repos.
-    uses: storytold/craft-common-actions/.github/workflows/windows-arm64.yml@main
+    # Immutable supporting workflow revision until the new install contract lands upstream.
+    uses: storytold/craft-common-actions/.github/workflows/windows-arm64.yml@8bb4e5ab95443171104ad88113fe1ef9b0e5ce3f
     with:
       app-name: effectcraft
       app-dir: EffectCraft
+      install-relative-path: Programs/ArtCraft/EffectCraft
+      install-scope: perUser
diff --git a/CLAUDE.md b/CLAUDE.md
index e52386942..21f2df36b 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -22,6 +22,7 @@ EffectCraft is a clean-room, open-source, pure-Rust motion graphics and visual e
 - **Everything is agent-drivable:** every interactive widget registers an automation id; UI state is serde.
 - **Community links** (Help menu, About, header Discord button): https://discord.gg/artcraft, https://getartcraft.com, https://getartcraft.com/apps/effectcraft, https://github.com/storytold/effectcraft.
 - **Quality gates** before every commit: `cargo xtask ci` (fmt, clippy -D warnings, tests, layers, assets, wasm).
+- **New workspace crates** must include `[lints] workspace = true` in `Cargo.toml` to inherit `[workspace.lints]`. Production crate roots must declare the required crate-level lint attributes before modules or other crate items; crate-level `//!` documentation may precede them.
 - **Commits:** one task id per commit (`M6.3: trim paths`). Only green states.
 
 ## Running and looking at the app
diff --git a/Cargo.lock b/Cargo.lock
index a4bcdf006..a6611ffba 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -860,6 +860,15 @@ dependencies = [
  "error-code",
 ]
 
+[[package]]
+name = "cobs"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fa961b519f0b462e3a3b4a34b64d119eeaca1d59af726fe450bbba07a9fc0a1"
+dependencies = [
+ "thiserror 2.0.21",
+]
+
 [[package]]
 name = "codespan-reporting"
 version = "0.13.1"
@@ -1038,34 +1047,81 @@ dependencies = [
 [[package]]
 name = "craft-docpath"
 version = "0.1.0"
-source = "git+https://github.com/storytold/craft-libs?rev=512b54355cd1418f4e8c56a3fbd7483c3c274bf3#512b54355cd1418f4e8c56a3fbd7483c3c274bf3"
+source = "git+https://github.com/storytold/craft-libs?rev=92d392cff132eaf53e13afff77f38b5c11b73aa0#92d392cff132eaf53e13afff77f38b5c11b73aa0"
+
+[[package]]
+name = "craft-fonts-build"
+version = "0.1.0"
+source = "git+https://github.com/storytold/craft-libs?rev=92d392cff132eaf53e13afff77f38b5c11b73aa0#92d392cff132eaf53e13afff77f38b5c11b73aa0"
+
+[[package]]
+name = "craft-i18n"
+version = "0.1.0"
+source = "git+https://github.com/storytold/craft-libs?rev=92d392cff132eaf53e13afff77f38b5c11b73aa0#92d392cff132eaf53e13afff77f38b5c11b73aa0"
+dependencies = [
+ "fixed_decimal",
+ "icu_decimal",
+ "icu_locale_core",
+ "icu_locale_fallback",
+ "icu_normalizer",
+ "icu_plurals",
+ "icu_properties",
+ "icu_provider",
+ "icu_provider_adapters",
+ "icu_provider_blob",
+ "log",
+ "objc2-foundation 0.3.2",
+ "sys-locale",
+ "unicode-bidi",
+ "windows-registry",
+ "writeable",
+]
 
 [[package]]
 name = "craft-pdf"
 version = "0.1.0"
-source = "git+https://github.com/storytold/craft-libs?rev=512b54355cd1418f4e8c56a3fbd7483c3c274bf3#512b54355cd1418f4e8c56a3fbd7483c3c274bf3"
+source = "git+https://github.com/storytold/craft-libs?rev=92d392cff132eaf53e13afff77f38b5c11b73aa0#92d392cff132eaf53e13afff77f38b5c11b73aa0"
 dependencies = [
  "hayro-syntax",
  "thiserror 2.0.21",
 ]
 
+[[package]]
+name = "craft-quit"
+version = "0.1.0"
+source = "git+https://github.com/storytold/craft-libs?rev=92d392cff132eaf53e13afff77f38b5c11b73aa0#92d392cff132eaf53e13afff77f38b5c11b73aa0"
+dependencies = [
+ "dispatch2",
+ "egui",
+ "objc2 0.6.5",
+ "objc2-app-kit 0.3.2",
+]
+
 [[package]]
 name = "craft-ui"
 version = "0.1.0"
-source = "git+https://github.com/storytold/craft-libs?rev=512b54355cd1418f4e8c56a3fbd7483c3c274bf3#512b54355cd1418f4e8c56a3fbd7483c3c274bf3"
+source = "git+https://github.com/storytold/craft-libs?rev=92d392cff132eaf53e13afff77f38b5c11b73aa0#92d392cff132eaf53e13afff77f38b5c11b73aa0"
 dependencies = [
+ "craft-fonts-build",
+ "craft-i18n",
  "egui",
+ "epaint",
+ "js-sys",
  "log",
  "objc2 0.6.5",
  "objc2-app-kit 0.3.2",
  "objc2-foundation 0.3.2",
  "serde",
+ "skrifa",
+ "wasm-bindgen",
+ "wasm-bindgen-futures",
+ "web-sys",
 ]
 
 [[package]]
 name = "craft-update"
 version = "0.1.0"
-source = "git+https://github.com/storytold/craft-libs?rev=512b54355cd1418f4e8c56a3fbd7483c3c274bf3#512b54355cd1418f4e8c56a3fbd7483c3c274bf3"
+source = "git+https://github.com/storytold/craft-libs?rev=92d392cff132eaf53e13afff77f38b5c11b73aa0#92d392cff132eaf53e13afff77f38b5c11b73aa0"
 dependencies = [
  "chrono",
  "dunce",
@@ -1284,7 +1340,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "cpal",
  "craft-update",
@@ -1310,7 +1366,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-automation"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-engine",
  "effectcraft-host",
@@ -1322,14 +1378,14 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-av1enc"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "filmcraft-av1",
 ]
 
 [[package]]
 name = "effectcraft-cli"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "cpu-time",
  "effectcraft-automation",
@@ -1345,7 +1401,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-color"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "proptest",
  "serde",
@@ -1353,7 +1409,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-effects"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "chrono",
  "effectcraft-color",
@@ -1371,7 +1427,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-engine"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "chrono",
  "craft-docpath",
@@ -1406,7 +1462,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-export"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-av1enc",
  "effectcraft-color",
@@ -1436,7 +1492,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-expr"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "boa_engine",
  "effectcraft-color",
@@ -1453,7 +1509,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-geom"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "proptest",
  "serde",
@@ -1461,7 +1517,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-gpu"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "bytemuck",
  "effectcraft-color",
@@ -1483,14 +1539,14 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-hevcenc"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "filmcraft-hevc",
 ]
 
 [[package]]
 name = "effectcraft-host"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-engine",
  "effectcraft-export",
@@ -1515,7 +1571,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-interchange"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-keyframe",
@@ -1534,7 +1590,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-keyframe"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-geom",
@@ -1546,7 +1602,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-lottie"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "craft-docpath",
  "effectcraft-color",
@@ -1564,7 +1620,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-media"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "craft-docpath",
  "effectcraft-model",
@@ -1593,7 +1649,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-model"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-geom",
  "image",
@@ -1606,14 +1662,14 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-opusenc"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "filmcraft-opus",
 ]
 
 [[package]]
 name = "effectcraft-path"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-geom",
  "effectcraft-keyframe",
@@ -1625,7 +1681,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-pdf"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "craft-pdf",
  "effectcraft-raster",
@@ -1641,7 +1697,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-plugin"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-effects",
  "effectcraft-keyframe",
@@ -1653,7 +1709,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-project"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-geom",
@@ -1666,14 +1722,14 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-psd"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "miniz_oxide 0.9.1",
 ]
 
 [[package]]
 name = "effectcraft-raster"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-geom",
@@ -1682,7 +1738,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-render"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-effects",
@@ -1704,7 +1760,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-script"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "boa_engine",
  "effectcraft-engine",
@@ -1722,7 +1778,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-segment"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "miniz_oxide 0.9.1",
  "ndarray",
@@ -1731,7 +1787,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-svg"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-geom",
  "effectcraft-path",
@@ -1743,7 +1799,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-text"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-keyframe",
  "harfrust",
@@ -1755,7 +1811,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-time"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "proptest",
  "serde",
@@ -1763,7 +1819,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-track"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-raster",
  "effectcraft-segment",
@@ -1775,9 +1831,10 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-ui-egui"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "chrono",
+ "craft-quit",
  "craft-ui",
  "craft-update",
  "effectcraft-color",
@@ -1809,11 +1866,11 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-vp9enc"
-version = "0.17.0"
+version = "0.18.0"
 
 [[package]]
 name = "effectcraft-web"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "effectcraft-engine",
  "effectcraft-export",
@@ -2447,6 +2504,17 @@ version = "0.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "aedcfb3409746eddb02b9e19ebda1c3394f759a152e48ee875a0844d1b955484"
 
+[[package]]
+name = "fixed_decimal"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2214fb00f669ee96bee5bb29dfb1ddabe058b2bc426817efc79afa03c9bc55ae"
+dependencies = [
+ "displaydoc",
+ "smallvec",
+ "writeable",
+]
+
 [[package]]
 name = "fixedbitset"
 version = "0.5.7"
@@ -2871,7 +2939,7 @@ checksum = "9f4d0e94ddd48749f06bbe4e5389fb9799a0c45bcaf00495042076ef05e3241a"
 [[package]]
 name = "hayro-jbig2"
 version = "0.3.0"
-source = "git+https://github.com/storytold/craft-libs?rev=512b54355cd1418f4e8c56a3fbd7483c3c274bf3#512b54355cd1418f4e8c56a3fbd7483c3c274bf3"
+source = "git+https://github.com/storytold/craft-libs?rev=92d392cff132eaf53e13afff77f38b5c11b73aa0#92d392cff132eaf53e13afff77f38b5c11b73aa0"
 dependencies = [
  "hayro-ccitt",
 ]
@@ -2885,7 +2953,7 @@ checksum = "c75ab947623ef4ccaa7acf0579edf7cbb5a73838e3839a7be73335e522f433a1"
 [[package]]
 name = "hayro-syntax"
 version = "0.7.2"
-source = "git+https://github.com/storytold/craft-libs?rev=512b54355cd1418f4e8c56a3fbd7483c3c274bf3#512b54355cd1418f4e8c56a3fbd7483c3c274bf3"
+source = "git+https://github.com/storytold/craft-libs?rev=92d392cff132eaf53e13afff77f38b5c11b73aa0#92d392cff132eaf53e13afff77f38b5c11b73aa0"
 dependencies = [
  "hayro-jbig2",
  "hayro-jpeg2000",
@@ -2943,6 +3011,23 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "icu_decimal"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9eb8f655bba2d0c0459e43a5b0e6cd3cd388109898fb3d85d048165e8b0abd08"
+dependencies = [
+ "displaydoc",
+ "fixed_decimal",
+ "icu_locale_core",
+ "icu_pattern",
+ "icu_plurals",
+ "icu_provider",
+ "serde",
+ "writeable",
+ "zerovec",
+]
+
 [[package]]
 name = "icu_locale_core"
 version = "2.3.0"
@@ -2951,11 +3036,32 @@ checksum = "d56e28588da92eee5c3201a6eff33fabdd49b62269c8938d4ff050ce4d900deb"
 dependencies = [
  "displaydoc",
  "litemap",
+ "serde",
  "tinystr",
  "writeable",
  "zerovec",
 ]
 
+[[package]]
+name = "icu_locale_fallback"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "251af8e57c9400e3eb58242fe5b8b1152b2a64fdf4cf632f923c38ccee6f2fa9"
+dependencies = [
+ "icu_locale_core",
+ "icu_locale_fallback_data",
+ "icu_provider",
+ "potential_utf",
+ "tinystr",
+ "zerovec",
+]
+
+[[package]]
+name = "icu_locale_fallback_data"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "decf2a22ec8fa68f1a0c1129a3f8583f8f8bc24e8b9ccbe98ead99f62a4dc3a8"
+
 [[package]]
 name = "icu_normalizer"
 version = "2.3.0"
@@ -2968,6 +3074,7 @@ dependencies = [
  "icu_provider",
  "smallvec",
  "utf16_iter",
+ "utf8_iter",
  "write16",
  "zerovec",
 ]
@@ -2978,6 +3085,32 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1563da1ed3e0b3bf3d74c9b85917ac9c56464d2f57242270c09c9e752f8021a0"
 
+[[package]]
+name = "icu_pattern"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b3db611446bd92c246b03e4aa0bafa71ddb194af431ddbb42b9d70e4bfce1a0"
+dependencies = [
+ "displaydoc",
+ "either",
+ "serde",
+ "writeable",
+ "zerovec",
+]
+
+[[package]]
+name = "icu_plurals"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e475e6766ef87b1d3c1f97be6363995b0bfaeddbc789671615df598a97ff0593"
+dependencies = [
+ "displaydoc",
+ "fixed_decimal",
+ "icu_provider",
+ "serde",
+ "zerovec",
+]
+
 [[package]]
 name = "icu_properties"
 version = "2.3.0"
@@ -3007,6 +3140,9 @@ checksum = "d27bbb9d3abbefac45d55f647c9de1d44aafcd1186eb91879afef17c396c3e73"
 dependencies = [
  "displaydoc",
  "icu_locale_core",
+ "postcard",
+ "serde",
+ "stable_deref_trait",
  "writeable",
  "yoke",
  "zerofrom",
@@ -3014,6 +3150,30 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "icu_provider_adapters"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df887bc4f55dbc773c7c45a0c7dfa75be886f7b7812830a71ab7271cc1801820"
+dependencies = [
+ "icu_locale_fallback",
+ "icu_provider",
+]
+
+[[package]]
+name = "icu_provider_blob"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5916b44fac319d3f58e4d8d805a627df19e27937b582cd99fcde3bb6b7ce1b0e"
+dependencies = [
+ "icu_provider",
+ "postcard",
+ "serde",
+ "writeable",
+ "zerotrie",
+ "zerovec",
+]
+
 [[package]]
 name = "idna"
 version = "1.1.0"
@@ -3329,6 +3489,9 @@ name = "litemap"
 version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "47d9d19d1d6efa0109d2f65ff4c85cddd50bd572e5a00127ab10987290bcefae"
+dependencies = [
+ "serde_core",
+]
 
 [[package]]
 name = "litrs"
@@ -4321,12 +4484,24 @@ dependencies = [
  "portable-atomic",
 ]
 
+[[package]]
+name = "postcard"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6764c3b5dd454e283a30e6dfe78e9b31096d9e32036b5d1eaac7a6119ccb9a24"
+dependencies = [
+ "cobs",
+ "serde",
+]
+
 [[package]]
 name = "potential_utf"
 version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d83eb9bc6d8e5cf568e7a1101d60ee05e81ed50ea106026f3d18deeb046d7661"
 dependencies = [
+ "serde_core",
+ "writeable",
  "zerovec",
 ]
 
@@ -5407,7 +5582,10 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8eab9a99a024a169fe8a903cf9d4a3b3601109bcc13bd9e3c6fff259138626c4"
 dependencies = [
+ "js-sys",
  "libc",
+ "wasm-bindgen",
+ "web-sys",
 ]
 
 [[package]]
@@ -5579,6 +5757,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b1e27c91459209c2986af3dcf603a5a74a4368754ce37414f59acc971167f643"
 dependencies = [
  "displaydoc",
+ "serde_core",
  "zerovec",
 ]
 
@@ -6624,6 +6803,17 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "windows-registry"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "02752bf7fbdcce7f2a27a742f798510f3e5ad88dbe84871e5168e2120c3d5720"
+dependencies = [
+ "windows-link",
+ "windows-result 0.4.1",
+ "windows-strings",
+]
+
 [[package]]
 name = "windows-result"
 version = "0.1.2"
@@ -6937,6 +7127,9 @@ name = "writeable"
 version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3ad82d2a33cdc9674dc7465672f271e096168fcdbe0f799d9e6db8c5892679dc"
+dependencies = [
+ "either",
+]
 
 [[package]]
 name = "x11-dl"
@@ -7003,7 +7196,7 @@ checksum = "e450f9b2ed1dff33c94c12589a87338689467b9c4f5d8a5710bd09a847d2c8a7"
 
 [[package]]
 name = "xtask"
-version = "0.17.0"
+version = "0.18.0"
 dependencies = [
  "chrono",
  "serde_json",
@@ -7193,8 +7386,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4ea269c3bd32f0a32c321907a2ae912ba6f4649bb0fc764a15627e99a7095a3f"
 dependencies = [
  "displaydoc",
+ "litemap",
+ "serde_core",
  "yoke",
  "zerofrom",
+ "zerovec",
 ]
 
 [[package]]
@@ -7203,6 +7399,7 @@ version = "0.11.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bb0464e17806c1d976d5cba29399c7f08e516e279e2ba493f63123b5fca67dd8"
 dependencies = [
+ "serde",
  "yoke",
  "zerofrom",
  "zerovec-derive",
diff --git a/Cargo.toml b/Cargo.toml
index fe6d2ddcc..aa917fc63 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,16 +4,17 @@ members = ["crates/*", "apps/*", "xtask"]
 default-members = ["crates/*", "apps/*"]
 
 [workspace.package]
-version = "0.17.0"
+version = "0.18.0"
 edition = "2024"
 license = "MIT OR Apache-2.0"
 rust-version = "1.95"
 repository = "https://github.com/storytold/effectcraft"
 
 [workspace.dependencies]
-craft-pdf = { git = "https://github.com/storytold/craft-libs", rev = "512b54355cd1418f4e8c56a3fbd7483c3c274bf3", version = "=0.1.0", default-features = false, features = ["read"] }
-craft-docpath = { version = "0.1.0", git = "https://github.com/storytold/craft-libs", rev = "512b54355cd1418f4e8c56a3fbd7483c3c274bf3" }
-craft-update = { git = "https://github.com/storytold/craft-libs", version = "=0.1.0", rev = "512b54355cd1418f4e8c56a3fbd7483c3c274bf3", features = ["egui"] }
+craft-pdf = { git = "https://github.com/storytold/craft-libs", rev = "92d392cff132eaf53e13afff77f38b5c11b73aa0", version = "=0.1.0", default-features = false, features = ["read"] }
+craft-docpath = { version = "0.1.0", git = "https://github.com/storytold/craft-libs", rev = "92d392cff132eaf53e13afff77f38b5c11b73aa0" }
+craft-quit = { version = "0.1.0", git = "https://github.com/storytold/craft-libs", rev = "92d392cff132eaf53e13afff77f38b5c11b73aa0" }
+craft-update = { git = "https://github.com/storytold/craft-libs", version = "=0.1.0", rev = "92d392cff132eaf53e13afff77f38b5c11b73aa0", features = ["egui"] }
 # internal
 effectcraft-time = { path = "crates/time" }
 effectcraft-geom = { path = "crates/geom" }
@@ -108,7 +109,7 @@ pollster = "1"
 # ui
 # Shared frontend components; keep this dependency above the engine boundary.
 # Shared UI and the complete egui family select reviewed immutable commits below.
-craft-ui = { version = "0.1.0", git = "https://github.com/storytold/craft-libs", rev = "512b54355cd1418f4e8c56a3fbd7483c3c274bf3", features = ["serde"] }
+craft-ui = { version = "0.1.0", git = "https://github.com/storytold/craft-libs", rev = "92d392cff132eaf53e13afff77f38b5c11b73aa0", features = ["serde"] }
 # `default_fonts` and `monochrome_emoji_fonts` are explicit: the app's `FontDefinitions::default()`
 # and its `✔`/`▣` chrome glyphs need both, and kittest's own dev-dependencies do not propagate.
 egui = { version = "0.37", default-features = false, features = ["default_fonts", "monochrome_emoji_fonts"] }
@@ -135,9 +136,11 @@ sys-locale = "0.3"
 unsafe_code = "forbid"
 
 [workspace.lints.clippy]
+cognitive_complexity = "deny"
+too_many_arguments = "deny"
+wildcard_imports = "deny"
 dbg_macro = "warn"
 todo = "warn"
-too_many_arguments = "allow"
 needless_range_loop = "allow"
 type_complexity = "allow"
 
@@ -220,8 +223,8 @@ lto = "thin"
 codegen-units = 1
 
 [patch.crates-io]
-hayro-syntax = { git = "https://github.com/storytold/craft-libs", rev = "512b54355cd1418f4e8c56a3fbd7483c3c274bf3", version = "=0.7.2" }
-hayro-jbig2 = { git = "https://github.com/storytold/craft-libs", rev = "512b54355cd1418f4e8c56a3fbd7483c3c274bf3", version = "=0.3.0" }
+hayro-syntax = { git = "https://github.com/storytold/craft-libs", rev = "92d392cff132eaf53e13afff77f38b5c11b73aa0", version = "=0.7.2" }
+hayro-jbig2 = { git = "https://github.com/storytold/craft-libs", rev = "92d392cff132eaf53e13afff77f38b5c11b73aa0", version = "=0.3.0" }
 ecolor = { git = "https://github.com/storytold/egui.git", rev = "6d518fc799681571963842f95b55a6b68431b15a" }
 emath = { git = "https://github.com/storytold/egui.git", rev = "6d518fc799681571963842f95b55a6b68431b15a" }
 epaint = { git = "https://github.com/storytold/egui.git", rev = "6d518fc799681571963842f95b55a6b68431b15a" }
diff --git a/README.md b/README.md
index 5fa28f0bb..81d42360c 100644
--- a/README.md
+++ b/README.md
@@ -275,9 +275,13 @@ send us right now.
 | arm64 (Snapdragon and other ARM PCs) | `effectcraft-<ver>-windows-arm64.msi` | `effectcraft-<ver>-windows-arm64-portable.zip` |
 | x86 (32-bit) | `effectcraft-<ver>-windows-x86.msi` | `effectcraft-<ver>-windows-x86-portable.zip` |
 
-Installers and executables are code-signed. The installer asks where to install EffectCraft
-(Program Files by default), and later versions install into the same folder. To install silently
+Installers and executables are code-signed. The installer asks who to install EffectCraft for and where. By default it installs for your
+account only, into `%LOCALAPPDATA%\Programs\ArtCraft\EffectCraft`, without an administrator prompt;
+"Everyone on this computer" installs into `C:\Program Files\ArtCraft\EffectCraft` (`Program Files (x86)` for the 32-bit build). Later versions
+install into the same folder. To install silently
 into a folder of your choice: `msiexec /i effectcraft-<ver>-windows-x64.msi /qn INSTALLFOLDER="D:\Apps\EffectCraft"`.
+A silent install is per-user by default. `INSTALLFOLDER` chooses the folder, not who it is installed for;
+add `ALLUSERS=1`, from an elevated terminal or deployment tool, for an all-users install.
 
 ### macOS
 
diff --git a/apps/effectcraft-cli/tests/it/qa_template.rs b/apps/effectcraft-cli/tests/it/qa_template.rs
index 8cb533fda..ffbdb94e9 100644
--- a/apps/effectcraft-cli/tests/it/qa_template.rs
+++ b/apps/effectcraft-cli/tests/it/qa_template.rs
@@ -152,6 +152,13 @@ fn essential_graphics_template_via_script_and_commands() {
     assert_eq!(image::open(&frames[0]).unwrap().to_rgba8(), edit);
     assert_eq!(std::fs::read(dir.join("lt.ectemplate")).unwrap(), original_template);
 
+    invalid_template_values_fail_cleanly(&dir);
+    template_usage_errors(&dir);
+    rational_template_keeps_exact_rate(&dir, &original_template);
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+fn invalid_template_values_fail_cleanly(dir: &PathBuf) {
     // Invalid values fail before the queue creates an output directory, or frame rendering
     // overwrites an existing output. A JSON object and existing control names are required.
     for (name, values, expected) in [
@@ -164,25 +171,27 @@ fn essential_graphics_template_via_script_and_commands() {
         std::fs::write(dir.join(&values_file), values).unwrap();
         let output_dir = dir.join(format!("failed-{name}"));
         let out = output_dir.join("frame_[#####].png");
-        let (code, error) = cli(&dir, &["render", "--template", "lt.ectemplate", "--values", &values_file, "--out", out.to_str().unwrap()]);
+        let (code, error) = cli(dir, &["render", "--template", "lt.ectemplate", "--values", &values_file, "--out", out.to_str().unwrap()]);
         assert_eq!(code, 1, "{name}: {error}");
         assert!(error["error"].as_str().unwrap().contains(expected), "{name}: {error}");
         assert!(!output_dir.exists(), "{name}: invalid input created render output");
         std::fs::write(dir.join("untouched.png"), b"existing output").unwrap();
-        let (code, error) = cli(&dir, &["render-frame", "--template", "lt.ectemplate", "--values", &values_file, "--out", "untouched.png"]);
+        let (code, error) = cli(dir, &["render-frame", "--template", "lt.ectemplate", "--values", &values_file, "--out", "untouched.png"]);
         assert_eq!(code, 1, "{name}: {error}");
         assert_eq!(std::fs::read(dir.join("untouched.png")).unwrap(), b"existing output");
     }
-    let (code, error) = cli(&dir, &["render-frame", "--template", "lt.ectemplate", "--values", "missing-values.json", "--out", "missing.png"]);
+    let (code, error) = cli(dir, &["render-frame", "--template", "lt.ectemplate", "--values", "missing-values.json", "--out", "missing.png"]);
     assert_eq!(code, 1, "{error}");
     assert!(error["error"].as_str().unwrap().contains("cannot read values"), "{error}");
     assert!(!dir.join("missing.png").exists());
     std::fs::write(dir.join("large-values.json"), vec![b' '; 1024 * 1024 + 1]).unwrap();
-    let (code, error) = cli(&dir, &["render-frame", "--template", "lt.ectemplate", "--values", "large-values.json", "--out", "large.png"]);
+    let (code, error) = cli(dir, &["render-frame", "--template", "lt.ectemplate", "--values", "large-values.json", "--out", "large.png"]);
     assert_eq!(code, 1, "{error}");
     assert!(error["error"].as_str().unwrap().contains("exceeds 1 MiB"), "{error}");
     assert!(!dir.join("large.png").exists());
+}
 
+fn template_usage_errors(dir: &PathBuf) {
     for args in [
         vec!["render-frame", "--values", "values.json"],
         vec!["info", "--template", "lt.ectemplate"],
@@ -191,10 +200,12 @@ fn essential_graphics_template_via_script_and_commands() {
         vec!["render", "--template", "lt.ectemplate", "--queue"],
         vec!["render-frame", "--template", "lt.ectemplate", "--bridge", "1"],
     ] {
-        let output = Command::new(crate::binary()).current_dir(&dir).args(&args).output().unwrap();
+        let output = Command::new(crate::binary()).current_dir(dir).args(&args).output().unwrap();
         assert_eq!(output.status.code(), Some(2), "{args:?}: {}", String::from_utf8_lossy(&output.stderr));
     }
+}
 
+fn rational_template_keeps_exact_rate(dir: &PathBuf, original_template: &[u8]) {
     // File-loaded templates can use exact rational rates that comp.new's float parser rounds.
     // Preserve that rate, Tick duration, work area, background and locked source layers.
     let mut project = effectcraft_engine::project::Project::from_json(&std::fs::read_to_string(dir.join("t.ecproj")).unwrap()).unwrap();
@@ -207,13 +218,13 @@ fn essential_graphics_template_via_script_and_commands() {
     comp.background = [0.08, 0.16, 0.24];
     comp.layers.first_mut().unwrap().switches.locked = true;
     std::fs::write(dir.join("rational.ecproj"), project.to_json()).unwrap();
-    ok(&dir, &["exec", "essential.exportTemplate", r#"{"comp":"Lower Third","path":"rational.ectemplate"}"#, "rational.ecproj"]);
+    ok(dir, &["exec", "essential.exportTemplate", r#"{"comp":"Lower Third","path":"rational.ectemplate"}"#, "rational.ecproj"]);
     let rational_template = std::fs::read(dir.join("rational.ectemplate")).unwrap();
-    let rational = ok(&dir, &["render-frame", "--template", "rational.ectemplate", "--frame", "5", "--out", "rational.png"]);
+    let rational = ok(dir, &["render-frame", "--template", "rational.ectemplate", "--frame", "5", "--out", "rational.png"]);
     assert!((rational["time"].as_f64().unwrap() - 5.0 / rate.as_f64()).abs() < 1e-9, "{rational}");
     assert_eq!((rational["width"].as_u64().unwrap(), rational["height"].as_u64().unwrap()), (320, 90));
     let output = dir.join("rational-work-area/frame_[#####].png");
-    ok(&dir, &["render", "--template", "rational.ectemplate", "--work-area", "--out", output.to_str().unwrap(), "--format", "png", "--resolution", "0.05"]);
+    ok(dir, &["render", "--template", "rational.ectemplate", "--work-area", "--out", output.to_str().unwrap(), "--format", "png", "--resolution", "0.05"]);
     let count = std::fs::read_dir(dir.join("rational-work-area"))
         .unwrap()
         .filter_map(Result::ok)
@@ -222,8 +233,8 @@ fn essential_graphics_template_via_script_and_commands() {
     assert_eq!(count, 4, "the template's exact work area contains frames 3 through 6");
     assert_eq!(std::fs::read(dir.join("rational.ectemplate")).unwrap(), rational_template);
     assert_eq!(std::fs::read(dir.join("lt.ectemplate")).unwrap(), original_template);
-    let _ = std::fs::remove_dir_all(&dir);
 }
+
 fn template_output_alias_fixture(case: &str) -> PathBuf {
     let dir = std::env::temp_dir().join(format!("ec-qa-template-output-{case}-{}", std::process::id()));
     let _ = std::fs::remove_dir_all(&dir);
diff --git a/apps/effectcraft-web/src/files.rs b/apps/effectcraft-web/src/files.rs
index 206314e4b..f6aac5aa4 100644
--- a/apps/effectcraft-web/src/files.rs
+++ b/apps/effectcraft-web/src/files.rs
@@ -151,6 +151,10 @@ impl Services for WebServices {
     fn is_dir(&self, _path: &str) -> bool {
         false
     }
+    /// The table's keys are the paths themselves.
+    fn full_path(&self, path: &str) -> Option<String> {
+        Some(path.to_string())
+    }
 }
 
 /// Media import from the table (the bytes are also handed to the media pool, which decodes them).
diff --git a/apps/effectcraft-web/src/frames.rs b/apps/effectcraft-web/src/frames.rs
index c7f350526..69089e308 100644
--- a/apps/effectcraft-web/src/frames.rs
+++ b/apps/effectcraft-web/src/frames.rs
@@ -311,10 +311,11 @@ pub fn stats() -> Value {
     })
 }
 
+type PendingFrameCheck = (js_sys::Function, js_sys::Function, (u32, u32, Vec<u8>), f64);
+
 thread_local! {
     /// `workerFrameCheck` promises waiting for their frame: id → (resolve, reject, local frame).
-    #[allow(clippy::type_complexity)]
-    static CHECKS: RefCell<std::collections::HashMap<u64, (js_sys::Function, js_sys::Function, (u32, u32, Vec<u8>), f64)>> = RefCell::new(Default::default());
+    static CHECKS: RefCell<std::collections::HashMap<u64, PendingFrameCheck>> = RefCell::new(Default::default());
 }
 
 /// `effectcraft.workerFrameCheck({time?, scale?, backend?})`: render the active comp's frame in
diff --git a/apps/effectcraft/src/main.rs b/apps/effectcraft/src/main.rs
index 6df015290..64ab5443d 100644
--- a/apps/effectcraft/src/main.rs
+++ b/apps/effectcraft/src/main.rs
@@ -9,8 +9,8 @@
 //!
 //! `--control <port>` (or `EFFECTCRAFT_CONTROL_PORT`) starts a localhost JSON-lines control server;
 //! see `effectcraft_ui_egui::control` for the methods.
-#![cfg_attr(all(target_os = "windows", not(debug_assertions)), windows_subsystem = "windows")]
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+#![cfg_attr(all(target_os = "windows", not(debug_assertions)), windows_subsystem = "windows")]
 
 // Built everywhere so its tests run on every platform; only Linux AppImages use it.
 mod appearance;
@@ -365,14 +365,11 @@ fn main() -> eframe::Result {
             }))
         }),
     );
-    match &result {
-        Ok(()) => log::info!("the window closed"),
-        Err(e) => {
-            if on_gl {
-                launch_guard::opengl_failed(effectcraft_host::config_dir().as_deref());
-            }
-            startup_failed(e, !on_gl && cfg!(not(target_os = "macos")));
+    if let Err(e) = &result {
+        if on_gl {
+            launch_guard::opengl_failed(effectcraft_host::config_dir().as_deref());
         }
+        startup_failed(e, !on_gl && cfg!(not(target_os = "macos")));
     }
     result
 }
@@ -455,7 +452,8 @@ struct Desktop {
 }
 
 impl eframe::App for Desktop {
-    /// The desktop host's logic tick: update the macOS menu bar, run the shared app tick and close the IME pass.
+    /// The desktop host's logic tick: update the macOS menu bar, run the shared app tick, close the IME pass, show the
+    /// file dialogs asked for and, last, hand a close to the platform quit.
     fn logic(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame) {
         #[cfg(target_os = "macos")]
         self.menu.update(&mut self.app, ctx);
@@ -464,6 +462,7 @@ impl eframe::App for Desktop {
         if let Some(asked) = &self.file_dialogs {
             sheet_dialogs::show_asked(asked, frame, ctx);
         }
+        effectcraft_ui_egui::panels::unsaved::quit_on_close(ctx);
     }
 
     fn ui(&mut self, ui: &mut egui::Ui, frame: &mut eframe::Frame) {
@@ -484,6 +483,9 @@ impl eframe::App for Desktop {
     }
 
     fn on_exit(&mut self) {
+        // On macOS the app quits through `-[NSApplication terminate:]`, and the process ends
+        // before `eframe::run_native` returns (#341).
+        log::info!("the window is closing");
         self.launch.exited();
         self.window.save(self.app.session.config.as_deref());
         self.app.on_exit();
diff --git a/apps/effectcraft/tests/args.rs b/apps/effectcraft/tests/args.rs
index 41281eb23..62c591b45 100644
--- a/apps/effectcraft/tests/args.rs
+++ b/apps/effectcraft/tests/args.rs
@@ -1,6 +1,4 @@
 //! The desktop binary rejects a bad command line before it starts anything (#997).
-// Integration tests: unwrapping and panicking on failure is fine here.
-#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
 
 use std::path::PathBuf;
 use std::process::{Command, Stdio};
diff --git a/clippy.toml b/clippy.toml
index 4b6c79f55..3522a15b6 100644
--- a/clippy.toml
+++ b/clippy.toml
@@ -2,3 +2,7 @@ allow-unwrap-in-tests = true
 allow-expect-in-tests = true
 allow-panic-in-tests = true
 allow-indexing-slicing-in-tests = true
+disallowed-types = [
+    { path = "egui::ComboBox", reason = "use craft_ui::ComboBox: egui's combo box menu can't grow back while open (egui#5225)" },
+]
+cognitive-complexity-threshold = 30
diff --git a/crates/automation/tests/qa/compositing.rs b/crates/automation/tests/qa/compositing.rs
index 52d5e4fb2..da78ae116 100644
--- a/crates/automation/tests/qa/compositing.rs
+++ b/crates/automation/tests/qa/compositing.rs
@@ -7,6 +7,10 @@ use serde_json::{Value, json};
 
 use crate::harness::{Img, Qa, coverage, luma, mean_diff};
 
+fn lum(i: &Img, x: u32, y: u32) -> f64 {
+    luma(i.get_pixel(x, y))
+}
+
 fn px(img: &Img, x: u32, y: u32) -> [u8; 4] {
     img.get_pixel(x, y).0
 }
@@ -25,13 +29,12 @@ fn write_sequence(qa: &Qa) -> String {
     qa.path("seq/ball_000.png")
 }
 
-#[test]
-fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
-    let mut qa = Qa::new("compositing");
-
+/// Import the sequence (reinterpreted at 12 fps) and a PSD written by the app; returns the
+/// sequence item and the PSD's composition.
+fn import_footage(qa: &mut Qa) -> (Value, Value) {
     // Footage: the sequence, and a layered PSD written by the app itself (Save Frame As ▸
     // Photoshop Layers) from a small comp.
-    let seq = write_sequence(&qa);
+    let seq = write_sequence(qa);
     let imp = qa.exec("file.import", json!({"paths": [seq]}));
     let seq_item = imp["items"][0].clone();
     let project = qa.tool("get_project", json!({}));
@@ -55,10 +58,14 @@ fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
     let pc = qa.tool("get_comp", json!({"comp": psd_comp.clone()}));
     let names: Vec<&str> = pc["layers"].as_array().unwrap().iter().map(|l| l["name"].as_str().unwrap()).collect();
     assert_eq!(names, ["Bar", "Gray"], "the PSD's layers, top first: {pc}");
+    (seq_item, psd_comp)
+}
 
+/// The main comp: the sequence plays, then a Screen-blended PSD; returns the Normal-mode frame.
+fn main_comp_and_blend(qa: &mut Qa, seq_item: &Value, psd_comp: &Value) -> Img {
     // The main comp.
-    let main = qa.exec("comp.new", json!({"name": "Main", "width": 160, "height": 90, "frameRate": 12, "duration": 1}))["comp"].clone();
-    qa.exec("layer.addItem", json!({"item": seq_item}));
+    qa.exec("comp.new", json!({"name": "Main", "width": 160, "height": 90, "frameRate": 12, "duration": 1}));
+    qa.exec("layer.addItem", json!({"item": seq_item.clone()}));
     let a = qa.frame(None, 0.0);
     let b = qa.frame(None, 0.5);
     assert!(mean_diff(&a, &b) > 1.0, "the sequence plays");
@@ -75,7 +82,10 @@ fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
     for c in 0..3 {
         assert!(s[c] > n[c] && s[c] > [32, 64, 96][c], "Screen brightens channel {c}: {s:?}");
     }
+    normal
+}
 
+fn track_matte(qa: &mut Qa) {
     // Track matte: a magenta solid seen only through text.
     qa.exec("layer.newText", json!({"text": "MATTE", "name": "Matte", "size": 40, "fill": "#ffffff"}));
     qa.exec("layer.newSolid", json!({"name": "Fill", "color": "#ff00ff", "width": 160, "height": 90}));
@@ -91,7 +101,9 @@ fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
     let fill = info["layers"].as_array().unwrap().iter().find(|l| l["name"] == "Fill").unwrap().clone();
     assert_eq!(fill["trackMatte"]["kind"], "Alpha Matte");
     qa.exec("layer.setSwitch", json!({"layers": ["Fill", "Matte"], "switch": "video", "value": false}));
+}
 
+fn adjustment_layer(qa: &mut Qa, normal: &Img) {
     // Adjustment layer: Lumetri exposure, inside a feathered, expanded elliptical mask; then Glow.
     qa.exec("layer.newAdjustment", json!({"name": "Grade"}));
     let fx = qa.exec("effect.apply", json!({"effect": "Lumetri Color", "layers": ["Grade"]}));
@@ -103,7 +115,6 @@ fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
     let mk = qa.exec("layer.addMask", json!({"layer": "Grade", "shape": "ellipse", "rect": [40, 20, 80, 50]}));
     assert!(mk["mask"].is_u64(), "{mk}");
     let hard = qa.frame(None, 0.5);
-    let lum = |i: &Img, x, y| luma(i.get_pixel(x, y));
     assert!(lum(&hard, 80, 45) > lum(&before, 80, 45) - 1.0 && lum(&hard, 5, 5) < lum(&before, 5, 5) - 10.0, "the mask limits the grade to the ellipse");
     qa.exec("layer.mask.set", json!({"layer": "Grade", "field": "expansion", "value": 8}));
     let grown = qa.frame(None, 0.5);
@@ -116,7 +127,7 @@ fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
         }
         n
     };
-    assert!(bright(&grown, &normal) > bright(&hard, &normal) + 100, "expansion grows the graded area");
+    assert!(bright(&grown, normal) > bright(&hard, normal) + 100, "expansion grows the graded area");
     qa.exec("layer.mask.set", json!({"layer": "Grade", "field": "feather", "value": 20}));
     let soft = qa.frame(None, 0.5);
     // At the ellipse's edge (x = 40 − 8): feathered is in between none and full.
@@ -125,7 +136,10 @@ fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
     qa.exec("effect.apply", json!({"effect": "Glow", "layers": ["Grade"]}));
     let glow = qa.frame(None, 0.5);
     assert!(mean_diff(&soft, &glow) > 0.5, "Glow changes the frame");
+}
 
+/// The 3D stage with depth of field and a light; returns the stage comp.
+fn stage_3d(qa: &mut Qa) -> Value {
     // 3D stage: a near and a far card, a camera with depth of field, a light.
     let stage = qa.exec("comp.new", json!({"name": "Stage", "width": 160, "height": 90, "frameRate": 12, "duration": 1}))["comp"].clone();
     qa.exec("layer.newSolid", json!({"name": "Near", "color": "#ff4040", "width": 40, "height": 40}));
@@ -155,7 +169,10 @@ fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
     let advanced = qa.frame(None, 0.0);
     assert!(mean_diff(&classic, &advanced) > 0.2, "Advanced 3D renders the stage its own way");
     assert!(lum(&advanced, 50, 45) > 60.0, "Advanced 3D still lights the card");
+    stage
+}
 
+fn alpha_renders(qa: &mut Qa, stage: &Value) {
     // Renders with alpha: the stage has no background layer, so most of it is transparent.
     let mov = qa.path("stage.mov");
     let webm = qa.path("stage.webm");
@@ -165,7 +182,7 @@ fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
     assert!(done["items"].as_array().unwrap().iter().all(|i| i["status"] == "Done"), "{done}");
     let reference = qa.tool("render_frame", json!({"comp": stage.clone(), "time": 0, "transparent": true, "inline": false}));
     assert_eq!(reference["width"], 160);
-    let refa = alpha_frame(&mut qa, stage.clone());
+    let refa = alpha_frame(qa, stage.clone());
     assert!(px(&refa, 2, 2)[3] < 40 && px(&refa, 50, 45)[3] == 255, "render_frame transparent keeps alpha: {:?} {:?}", px(&refa, 2, 2), px(&refa, 50, 45));
     // ProRes 4444 carries alpha in the frame; WebM VP9 as a second VP9 stream in BlockAdditions
     // (AlphaMode 1), which FilmCraft's Matroska reader decodes into the frame's alpha plane.
@@ -174,14 +191,24 @@ fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
         assert_eq!(r["errors"], json!([]));
         assert_eq!(r["unlabeledAlpha"], r["items"], "{path}: the importer sees an alpha channel");
         let c = qa.exec("file.newCompFromSelection", json!({}))["comps"][0].clone();
-        let f = alpha_frame(&mut qa, c.clone());
+        let f = alpha_frame(qa, c.clone());
         // The opaque card decodes to the stage's colours (lossy codecs, so loosely).
         let (got, want) = (px(&f, 50, 45), px(&refa, 50, 45));
         assert!((0..3).all(|c| got[c].abs_diff(want[c]) < 12), "{path} decodes to the stage: {got:?} vs {want:?}");
         assert!(mean_diff(&qa.frame(Some(c.clone()), 0.0), &qa.frame(Some(stage.clone()), 0.0)) < 8.0, "{path} composites like the stage");
         assert!(px(&f, 2, 2)[3] < 40 && px(&f, 50, 45)[3] > 250, "{path}: transparent corners, opaque card: {:?} {:?}", px(&f, 2, 2), px(&f, 50, 45));
     }
-    let _ = main;
+}
+
+#[test]
+fn compositing_matte_blend_adjustment_3d_and_alpha_renders() {
+    let mut qa = Qa::new("compositing");
+    let (seq_item, psd_comp) = import_footage(&mut qa);
+    let normal = main_comp_and_blend(&mut qa, &seq_item, &psd_comp);
+    track_matte(&mut qa);
+    adjustment_layer(&mut qa, &normal);
+    let stage = stage_3d(&mut qa);
+    alpha_renders(&mut qa, &stage);
 }
 
 fn alpha_frame(qa: &mut Qa, comp: Value) -> Img {
diff --git a/crates/av1enc/src/cdf.rs b/crates/av1enc/src/cdf.rs
index 0466a1592..777164d1a 100644
--- a/crates/av1enc/src/cdf.rs
+++ b/crates/av1enc/src/cdf.rs
@@ -2,7 +2,15 @@
 //! init_coeff_cdfs that its syntax uses). Layout as in filmcraft-av1: each innermost array
 //! holds N cumulative values (the last is 32768) plus the adaptation counter.
 
-use crate::tables::*;
+use crate::tables::{
+    DEFAULT_ANGLE_DELTA_CDF, DEFAULT_COEFF_BASE_CDF, DEFAULT_COEFF_BASE_EOB_CDF, DEFAULT_COEFF_BR_CDF, DEFAULT_DC_SIGN_CDF, DEFAULT_DRL_MODE_CDF,
+    DEFAULT_EOB_EXTRA_CDF, DEFAULT_EOB_PT_16_CDF, DEFAULT_EOB_PT_32_CDF, DEFAULT_EOB_PT_64_CDF, DEFAULT_EOB_PT_128_CDF, DEFAULT_EOB_PT_256_CDF,
+    DEFAULT_EOB_PT_512_CDF, DEFAULT_EOB_PT_1024_CDF, DEFAULT_INTER_TX_TYPE_SET3_CDF, DEFAULT_INTRA_TX_TYPE_SET2_CDF, DEFAULT_IS_INTER_CDF, DEFAULT_MV_BIT_CDF,
+    DEFAULT_MV_CLASS_CDF, DEFAULT_MV_CLASS0_BIT_CDF, DEFAULT_MV_CLASS0_FR_CDF, DEFAULT_MV_FR_CDF, DEFAULT_MV_JOINT_CDF, DEFAULT_MV_SIGN_CDF,
+    DEFAULT_NEW_MV_CDF, DEFAULT_PARTITION_W8_CDF, DEFAULT_PARTITION_W16_CDF, DEFAULT_PARTITION_W32_CDF, DEFAULT_PARTITION_W64_CDF, DEFAULT_REF_MV_CDF,
+    DEFAULT_SINGLE_REF_CDF, DEFAULT_SKIP_CDF, DEFAULT_TXB_SKIP_CDF, DEFAULT_UV_MODE_CFL_ALLOWED_CDF, DEFAULT_UV_MODE_CFL_NOT_ALLOWED_CDF, DEFAULT_Y_MODE_CDF,
+    DEFAULT_ZERO_MV_CDF,
+};
 
 #[derive(Clone)]
 pub(crate) struct Cdfs {
diff --git a/crates/av1enc/src/decide.rs b/crates/av1enc/src/decide.rs
index 494e914c0..9bbd56823 100644
--- a/crates/av1enc/src/decide.rs
+++ b/crates/av1enc/src/decide.rs
@@ -3,8 +3,12 @@
 //! processes, so the reconstruction built here is exactly what a decoder produces; the syntax
 //! is written afterwards by `writer.rs`.
 
-use crate::pred::*;
-use crate::tables::*;
+use crate::pred::{INTRA_MODES_USED, InterBlock, IntraEdge, Plane, edges, predict_inter, predict_intra, subpel_plane};
+use crate::tables::{
+    AC_QLOOKUP, BLOCK_8X8, BLOCK_64X64, DC_PRED, DC_QLOOKUP, DCT_DCT, DEFAULT_SCAN_4X4, DEFAULT_SCAN_8X8, DEFAULT_SCAN_16X16, DEFAULT_SCAN_32X32, MODE_TO_TXFM,
+    NEWMV, NUM_4X4_BLOCKS_WIDE, PARTITION_SPLIT, PARTITION_SUBSIZE, TX_4X4, TX_8X8, TX_16X16, TX_32X32, TX_64X64, TX_SET_DCTONLY, TX_SET_INTER_3,
+    TX_SET_INTRA_2, TX_SIZE_SQR_UP, TX_TYPE_IN_SET_INTER, TX_TYPE_IN_SET_INTRA,
+};
 use crate::transform::{forward_2d, inverse_2d};
 
 /// Decisions for one coded block.
@@ -100,6 +104,17 @@ pub(crate) fn intra_uv_tx_type(uv_mode: usize, uv_tx: usize) -> usize {
     if tx_in_set(tx_set(uv_tx, false), false, t) { t } else { DCT_DCT }
 }
 
+/// Geometry and coding mode of one square transform block.
+#[derive(Clone, Copy)]
+struct TransformBlock {
+    plane: usize,
+    x: usize,
+    y: usize,
+    log2: u32,
+    tx_type: usize,
+    intra: bool,
+}
+
 struct TxResult {
     levels: Vec<i32>,
     nonzero: bool,
@@ -107,6 +122,38 @@ struct TxResult {
     bits: f64,
 }
 
+/// The output and scratch buffers of one reconstruction, each `n * n` entries long.
+struct ReconBuffers<'a> {
+    deq: &'a mut [i32],
+    resid: &'a mut [i32],
+    recon: &'a mut [u16],
+}
+
+/// Outcome of trying one transform block; the levels and the reconstruction stay in `TxScratch`.
+#[derive(Clone, Copy)]
+struct TxEval {
+    nonzero: bool,
+    dist: f64,
+    bits: f64,
+}
+
+/// Buffers of the transform path, sized for the largest coded transform block (32x32). Only the
+/// first `n * n` entries are used; they are reused across candidates instead of being allocated.
+struct TxScratch {
+    res: [i32; 1024],
+    coef: [f32; 1024],
+    levels: [i32; 1024],
+    deq: [i32; 1024],
+    resid: [i32; 1024],
+    recon: [u16; 1024],
+}
+
+impl Default for TxScratch {
+    fn default() -> Self {
+        TxScratch { res: [0; 1024], coef: [0.0; 1024], levels: [0; 1024], deq: [0; 1024], resid: [0; 1024], recon: [0; 1024] }
+    }
+}
+
 /// Saved encoder state of a block area (reconstruction, BlockDecoded flags).
 struct Snapshot {
     planes: [Vec<u16>; 3],
@@ -131,6 +178,8 @@ pub(crate) struct Decider<'a> {
     lambda_sad: f64,
     /// Half-sample interpolations of the reference luma (visible area): (8, 0), (0, 8), (8, 8).
     half: [Vec<u16>; 3],
+    /// Transform buffers, taken out while a block is being tried (see `code_tx`).
+    scratch: Option<Box<TxScratch>>,
 }
 
 const MODE_BITS_INTRA: f64 = 3.0;
@@ -166,6 +215,7 @@ impl<'a> Decider<'a> {
                 Some(rf) => [(8, 0), (0, 8), (8, 8)].map(|(fx, fy)| subpel_plane(&rf.planes[0], g.width, g.height, fx, fy, bd)),
                 None => Default::default(),
             },
+            scratch: None,
         }
     }
 
@@ -324,8 +374,10 @@ impl<'a> Decider<'a> {
         let log2 = (n4 * 4).trailing_zeros();
         let (sbr, sbc) = ((r & 15) as isize, (c & 15) as isize);
         let bd = self.bd;
-        let mut pred = vec![0u16; 32 * 32];
-        let mut best_pred = vec![0u16; 32 * 32];
+        let mut pred = [0u16; 32 * 32];
+        let mut best_pred = [0u16; 32 * 32];
+        let mut best_levels = [0i32; 32 * 32];
+        let mut best_recon = [0u16; 32 * 32];
         let n = 1usize << log2;
         // luma
         let e = IntraEdge {
@@ -343,26 +395,26 @@ impl<'a> Decider<'a> {
         let ed = edges(&self.rec[0], &e);
         // modes ranked by SATD, then a rate-distortion choice of mode and transform type among
         // the best three
-        let mut ranked: Vec<(f64, usize)> = INTRA_MODES_USED
-            .iter()
-            .map(|&mode| {
-                predict_intra(&ed, &e, mode, &mut pred);
-                let sad = self.satd(0, c * 4, r * 4, n, &pred[..n * n]) as f64;
-                (sad + self.lambda_sad * if mode == DC_PRED { 1.0 } else { MODE_BITS_INTRA }, mode)
-            })
-            .collect();
+        let mut ranked: [(f64, usize); INTRA_MODES_USED.len()] = INTRA_MODES_USED.map(|mode| {
+            predict_intra(&ed, &e, mode, &mut pred);
+            let sad = self.satd(0, c * 4, r * 4, n, &pred[..n * n]) as f64;
+            (sad + self.lambda_sad * if mode == DC_PRED { 1.0 } else { MODE_BITS_INTRA }, mode)
+        });
         ranked.sort_by(|a, b| a.0.total_cmp(&b.0));
         let tx_y = tx_size_for(log2);
-        let mut best: Option<(f64, usize, usize, TxResult, Option<Vec<u16>>)> = None;
+        let mut best: Option<(f64, usize, usize, TxEval, bool)> = None;
+        let mut sc = self.scratch.take().unwrap_or_default();
         for &(_, mode) in ranked.iter().take(3) {
             predict_intra(&ed, &e, mode, &mut pred);
-            let mut types = vec![DCT_DCT];
+            let mut types = [DCT_DCT; 2];
+            let mut n_types = 1;
             let alt = MODE_TO_TXFM[mode] as usize;
             if alt != DCT_DCT && tx_in_set(tx_set(tx_y, false), false, alt) {
-                types.push(alt);
+                types[1] = alt;
+                n_types = 2;
             }
-            for &t in &types {
-                let (res, recon) = self.try_tx(0, c * 4, r * 4, log2, t, &pred[..n * n], true);
+            for &t in &types[..n_types] {
+                let (res, has_recon) = self.try_tx(&mut sc, TransformBlock { plane: 0, x: c * 4, y: r * 4, log2, tx_type: t, intra: true }, &pred[..n * n]);
                 let type_bits = if !res.nonzero || tx_set(tx_y, false) == TX_SET_DCTONLY {
                     0.0
                 } else if t == DCT_DCT {
@@ -374,18 +426,24 @@ impl<'a> Decider<'a> {
                 let cost = res.dist + self.lambda * (res.bits + type_bits + mode_bits);
                 if best.as_ref().is_none_or(|b| cost < b.0) {
                     best_pred[..n * n].copy_from_slice(&pred[..n * n]);
-                    best = Some((cost, mode, t, res, recon));
+                    best_levels[..n * n].copy_from_slice(&sc.levels[..n * n]);
+                    if has_recon {
+                        best_recon[..n * n].copy_from_slice(&sc.recon[..n * n]);
+                    }
+                    best = Some((cost, mode, t, res, has_recon));
                 }
             }
         }
+        self.scratch = Some(sc);
         // Every ranked mode tries DCT_DCT, so `best` is always set; without a candidate the block
         // can't be coded intra (an infinite cost keeps it from being chosen).
-        let Some((_, y_mode, tx_type_y, ty, recon)) = best else {
+        let Some((_, y_mode, tx_type_y, ty, has_recon)) = best else {
             let leaf =
                 Leaf { bsize, is_inter: false, y_mode: DC_PRED, uv_mode: DC_PRED, tx_type_y: DCT_DCT, mv: [0, 0], skip: true, coefs: Default::default() };
             return (leaf, f64::INFINITY);
         };
-        self.put(0, c * 4, r * 4, n, recon.as_deref().unwrap_or(&best_pred[..n * n]));
+        self.put(0, c * 4, r * 4, n, if has_recon { &best_recon[..n * n] } else { &best_pred[..n * n] });
+        let ty = TxResult { levels: best_levels[..n * n].to_vec(), nonzero: ty.nonzero, dist: ty.dist, bits: ty.bits };
         let tx_type_y = if ty.nonzero { tx_type_y } else { DCT_DCT };
         self.mark_decoded(0, r, c, n4);
         // chroma (one mode for both planes)
@@ -422,7 +480,7 @@ impl<'a> Decider<'a> {
         let uv_type = intra_uv_tx_type(uv_mode, uv_tx);
         let mut code_uv = |i: usize| {
             predict_intra(&ced[i], &ce[i], uv_mode, &mut pred);
-            let t = self.code_tx(1 + i, c * 2, r * 2, clog2, uv_type, &pred[..cn * cn], true);
+            let t = self.code_tx(TransformBlock { plane: 1 + i, x: c * 2, y: r * 2, log2: clog2, tx_type: uv_type, intra: true }, &pred[..cn * cn]);
             self.mark_decoded(1 + i, r, c, n4);
             t
         };
@@ -450,13 +508,17 @@ impl<'a> Decider<'a> {
             let (vw, vh) = self.g.visible(p);
             let pn = n >> s;
             let (x, y) = ((c * 4) >> s, (r * 4) >> s);
-            predict_inter(&refr.planes[p], vw as i32 - 1, vh as i32 - 1, x, y, pn, pn, mv, s, self.bd, &mut pred[..pn * pn]);
+            predict_inter(
+                &refr.planes[p],
+                &InterBlock { last_x: vw as i32 - 1, last_y: vh as i32 - 1, x, y, width: pn, height: pn, mv, subsampling: s, bit_depth: self.bd },
+                &mut pred[..pn * pn],
+            );
             if bsize == BLOCK_64X64 {
                 // coded as a skip block: the prediction is the reconstruction
                 dist += self.sse(p, x, y, pn, &pred[..pn * pn]);
                 self.put(p, x, y, pn, &pred[..pn * pn]);
             } else {
-                let t = self.code_tx(p, x, y, log2 - s as u32, DCT_DCT, &pred[..pn * pn], false);
+                let t = self.code_tx(TransformBlock { plane: p, x, y, log2: log2 - s as u32, tx_type: DCT_DCT, intra: false }, &pred[..pn * pn]);
                 dist += t.dist;
                 tx.push(t);
             }
@@ -771,32 +833,38 @@ impl<'a> Decider<'a> {
 
     /// Transform, quantise and reconstruct one square transform block of `plane` at (x, y)
     /// over the prediction `pred`; the reconstruction is written to `rec`.
-    fn code_tx(&mut self, p: usize, x: usize, y: usize, log2: u32, tx_type: usize, pred: &[u16], intra: bool) -> TxResult {
-        let (res, recon) = self.try_tx(p, x, y, log2, tx_type, pred, intra);
+    fn code_tx(&mut self, block: TransformBlock, pred: &[u16]) -> TxResult {
+        let TransformBlock { plane: p, x, y, log2, .. } = block;
+        let mut sc = self.scratch.take().unwrap_or_default();
+        let (res, has_recon) = self.try_tx(&mut sc, block, pred);
         let n = 1usize << log2;
-        self.put(p, x, y, n, recon.as_deref().unwrap_or(pred));
-        res
+        self.put(p, x, y, n, if has_recon { &sc.recon[..n * n] } else { pred });
+        let levels = sc.levels[..n * n].to_vec();
+        self.scratch = Some(sc);
+        TxResult { levels, nonzero: res.nonzero, dist: res.dist, bits: res.bits }
     }
 
-    /// Transform and quantise one block; returns the result and its reconstruction (None: the
-    /// prediction) without writing it.
-    fn try_tx(&self, p: usize, x: usize, y: usize, log2: u32, tx_type: usize, pred: &[u16], intra: bool) -> (TxResult, Option<Vec<u16>>) {
+    /// Transform and quantise one block without writing it. The levels are left in `sc.levels`;
+    /// the flag tells whether `sc.recon` holds the reconstruction (false: it is the prediction).
+    fn try_tx(&self, sc: &mut TxScratch, block: TransformBlock, pred: &[u16]) -> (TxEval, bool) {
+        let TransformBlock { plane: p, x, y, log2, tx_type, intra } = block;
         let n = 1usize << log2;
+        let nn = n * n;
         let tx_sz = tx_size_for(log2);
         let bd = self.bd;
         let src = &self.src[p];
-        let mut res = vec![0i32; n * n];
+        let TxScratch { res, coef, levels, deq, resid, recon } = sc;
+        let (res, coef, levels) = (&mut res[..nn], &mut coef[..nn], &mut levels[..nn]);
         for i in 0..n {
             let row = &src.row(y + i)[x..x + n];
             for j in 0..n {
                 res[i * n + j] = row[j] as i32 - pred[i * n + j] as i32;
             }
         }
-        let mut coef = vec![0f32; n * n];
-        forward_2d(&res, &mut coef, n, tx_type);
+        forward_2d(res, coef, n, tx_type);
         // dead-zone quantiser: rounding offset below one half
         let rnd = if intra { 0.38f32 } else { 0.30f32 };
-        let mut levels = vec![0i32; n * n];
+        levels.fill(0);
         let mut nonzero = false;
         for (k, (&cf, l)) in coef.iter().zip(levels.iter_mut()).enumerate() {
             let q = if k == 0 { self.dc_q } else { self.ac_q };
@@ -808,23 +876,26 @@ impl<'a> Decider<'a> {
         }
         let zero_dist = self.sse(p, x, y, n, pred);
         if !nonzero {
-            return (TxResult { levels, nonzero, dist: zero_dist, bits: 1.0 }, None);
+            return (TxEval { nonzero, dist: zero_dist, bits: 1.0 }, false);
         }
-        let recon = self.reconstruct(&levels, tx_sz, tx_type, pred, n, bd);
-        let dist = self.sse(p, x, y, n, &recon);
-        let bits = estimate_bits(&levels, tx_sz);
+        let recon = &mut recon[..nn];
+        self.reconstruct(levels, ReconBuffers { deq: &mut deq[..nn], resid: &mut resid[..nn], recon }, tx_sz, tx_type, pred, bd);
+        let dist = self.sse(p, x, y, n, recon);
+        let bits = estimate_bits(levels, tx_sz);
         if dist + self.lambda * bits >= zero_dist + self.lambda {
-            levels.iter_mut().for_each(|l| *l = 0);
-            return (TxResult { levels, nonzero: false, dist: zero_dist, bits: 1.0 }, None);
+            levels.fill(0);
+            return (TxEval { nonzero: false, dist: zero_dist, bits: 1.0 }, false);
         }
-        (TxResult { levels, nonzero: true, dist, bits }, Some(recon))
+        (TxEval { nonzero: true, dist, bits }, true)
     }
 
-    /// Dequantisation (7.12.3) and the inverse transform, added to the prediction.
-    fn reconstruct(&self, levels: &[i32], tx_sz: usize, tx_type: usize, pred: &[u16], n: usize, bd: u32) -> Vec<u16> {
+    /// Dequantisation (7.12.3) and the inverse transform, added to the prediction; the result is
+    /// written to `recon`. `deq` and `resid` are scratch buffers of `n * n` entries.
+    fn reconstruct(&self, levels: &[i32], bufs: ReconBuffers, tx_sz: usize, tx_type: usize, pred: &[u16], bd: u32) {
+        let ReconBuffers { deq, resid, recon } = bufs;
         let denom: i64 = if tx_sz == TX_32X32 { 2 } else { 1 };
         let lim = 1i64 << (7 + bd);
-        let mut deq = vec![0i32; n * n];
+        deq.fill(0);
         for (k, (&l, d)) in levels.iter().zip(deq.iter_mut()).enumerate() {
             if l == 0 {
                 continue;
@@ -834,10 +905,11 @@ impl<'a> Decider<'a> {
             let mag = (dq.abs() & 0xFF_FFFF) / denom;
             *d = (if dq < 0 { -mag } else { mag }).clamp(-lim, lim - 1) as i32;
         }
-        let mut resid = vec![0i32; n * n];
-        inverse_2d(&deq, &mut resid, tx_sz, tx_type, bd);
+        inverse_2d(deq, resid, tx_sz, tx_type, bd);
         let max = (1i32 << bd) - 1;
-        pred.iter().zip(&resid).map(|(&p, &r)| (p as i32 + r).clamp(0, max) as u16).collect()
+        for ((o, &p), &r) in recon.iter_mut().zip(pred).zip(resid.iter()) {
+            *o = (p as i32 + r).clamp(0, max) as u16;
+        }
     }
 }
 
diff --git a/crates/av1enc/src/lib.rs b/crates/av1enc/src/lib.rs
index 6b1edfbe8..3fcf446bb 100644
--- a/crates/av1enc/src/lib.rs
+++ b/crates/av1enc/src/lib.rs
@@ -409,11 +409,13 @@ impl Encoder {
         };
         let bd = self.cfg.bit_depth as u32;
         let mut cache: Vec<(u32, u64)> = vec![(0, sse(&rec[0]))];
+        // one working copy of the luma plane for all candidate levels
+        let mut planes = [rec[0].clone(), Plane::new(0, 0), Plane::new(0, 0)];
         let mut eval = |lvl: u32| -> u64 {
             if let Some(&(_, e)) = cache.iter().find(|(l, _)| *l == lvl) {
                 return e;
             }
-            let mut planes = [rec[0].clone(), Plane::new(0, 0), Plane::new(0, 0)];
+            planes[0].data.copy_from_slice(&rec[0].data);
             loop_filter(&mut planes, info, [lvl; 4], bd, true, sb_row_step);
             let e = sse(&planes[0]);
             cache.push((lvl, e));
diff --git a/crates/av1enc/src/loopfilter.rs b/crates/av1enc/src/loopfilter.rs
index 2add41edc..cf350fbd2 100644
--- a/crates/av1enc/src/loopfilter.rs
+++ b/crates/av1enc/src/loopfilter.rs
@@ -3,7 +3,7 @@
 //! is 0 in the frames this encoder writes.
 
 use crate::pred::Plane;
-use crate::tables::*;
+use crate::tables::{MAX_LOOP_FILTER, NUM_4X4_BLOCKS_HIGH, NUM_4X4_BLOCKS_WIDE, SUBSAMPLED_SIZE, TX_HEIGHT, TX_WIDTH};
 
 /// Mode info the loop filter reads (per 4x4 luma unit, row stride `mi_cols`), and the
 /// transform size per 4x4 unit of each plane (`LoopfilterTxSizes`, row stride `mi_cols + 32`).
@@ -39,7 +39,7 @@ pub(crate) fn loop_filter(planes: &mut [Plane; 3], info: &LfInfo, level: [u32; 4
                 }
                 let mut col = 0;
                 while col < info.mi_cols {
-                    edge(pl, info, level, bit_depth, plane, pass, row, col);
+                    edge(pl, info, level, bit_depth, plane, pass, (row, col));
                     col += step;
                 }
                 row += step;
@@ -48,7 +48,8 @@ pub(crate) fn loop_filter(planes: &mut [Plane; 3], info: &LfInfo, level: [u32; 4
     }
 }
 
-fn edge(pl: &mut Plane, info: &LfInfo, level: [u32; 4], bd: u32, plane: usize, pass: usize, row: usize, col: usize) {
+fn edge(pl: &mut Plane, info: &LfInfo, level: [u32; 4], bd: u32, plane: usize, pass: usize, position: (usize, usize)) {
+    let (row, col) = position;
     let s = (plane > 0) as usize;
     let (dx, dy) = if pass == 0 { (1usize, 0usize) } else { (0, 1) };
     let x = col * 4;
@@ -88,13 +89,24 @@ fn edge(pl: &mut Plane, info: &LfInfo, level: [u32; 4], bd: u32, plane: usize, p
     let limit = lvl.max(1);
     let blimit = 2 * (lvl + 2) + limit;
     let thresh = lvl >> 4;
+    let strength = FilterStrength { limit, blimit, thresh };
     for k in 0..4 {
-        sample_filter(pl, xp + dy * k, yp + dx * k, plane, limit, blimit, thresh, dx as isize, dy as isize, filter_size, bd);
+        sample_filter(pl, (xp + dy * k, yp + dx * k), plane, &strength, (dx as isize, dy as isize), filter_size, bd);
     }
 }
 
+/// Thresholds derived from the loop-filter level (spec 7.14.4).
+struct FilterStrength {
+    limit: i32,
+    blimit: i32,
+    thresh: i32,
+}
+
 #[inline]
-fn sample_filter(pl: &mut Plane, x: usize, y: usize, plane: usize, limit: i32, blimit: i32, thresh: i32, dx: isize, dy: isize, filter_size: usize, bd: u32) {
+fn sample_filter(pl: &mut Plane, position: (usize, usize), plane: usize, strength: &FilterStrength, direction: (isize, isize), filter_size: usize, bd: u32) {
+    let (x, y) = position;
+    let (dx, dy) = direction;
+    let FilterStrength { limit, blimit, thresh } = *strength;
     let stride = pl.stride as isize;
     let step = dy * stride + dx;
     let base = y as isize * stride + x as isize;
diff --git a/crates/av1enc/src/pred.rs b/crates/av1enc/src/pred.rs
index d61a6fa94..7b354af1f 100644
--- a/crates/av1enc/src/pred.rs
+++ b/crates/av1enc/src/pred.rs
@@ -2,7 +2,10 @@
 //! modes plus V_PRED / H_PRED without edge filtering, 7.11.3 block inter prediction without
 //! reference scaling) so that the encoder predicts exactly like a decoder.
 
-use crate::tables::*;
+use crate::tables::{
+    DC_PRED, EIGHTTAP, H_PRED, PAETH_PRED, SM_WEIGHTS_TX_4X4, SM_WEIGHTS_TX_8X8, SM_WEIGHTS_TX_16X16, SM_WEIGHTS_TX_32X32, SMOOTH_H_PRED, SMOOTH_PRED,
+    SMOOTH_V_PRED, SUBPEL_FILTERS, V_PRED,
+};
 use crate::transform::round2;
 
 /// A plane buffer (padded to whole superblocks).
@@ -184,19 +187,20 @@ pub(crate) fn predict_intra(ed: &Edges, e: &IntraEdge, mode: usize, pred: &mut [
 /// final rounding is the identity) of the `w x h` block at plane position (x, y) displaced by
 /// `mv` (1/8 luma sample units, [row, col]). `last_x` / `last_y` are the largest sample
 /// coordinates of the reference plane; the result goes to `pred` (row stride `w`).
-pub(crate) fn predict_inter(
-    refp: &Plane,
-    last_x: i32,
-    last_y: i32,
-    x: usize,
-    y: usize,
-    w: usize,
-    h: usize,
-    mv: [i32; 2],
-    ss: usize,
-    bit_depth: u32,
-    pred: &mut [u16],
-) {
+pub(crate) struct InterBlock {
+    pub last_x: i32,
+    pub last_y: i32,
+    pub x: usize,
+    pub y: usize,
+    pub width: usize,
+    pub height: usize,
+    pub mv: [i32; 2],
+    pub subsampling: usize,
+    pub bit_depth: u32,
+}
+
+pub(crate) fn predict_inter(refp: &Plane, block: &InterBlock, pred: &mut [u16]) {
+    let InterBlock { last_x, last_y, x, y, width: w, height: h, mv, subsampling: ss, bit_depth } = *block;
     // positions in 1/16 sample units ((startX >> 6) & 15 is the filter phase)
     let px = ((x as i32) << 4) + ((2 * mv[1]) >> ss);
     let py = ((y as i32) << 4) + ((2 * mv[0]) >> ss);
@@ -340,7 +344,11 @@ mod tests {
             for (bx, by) in [(0i32, 0i32), (8, 8), (24, 16), (-5, 20), (30, -3)] {
                 let mut pred = vec![0u16; 64];
                 let mv = [by * 8 + fy as i32 / 2, bx * 8 + fx as i32 / 2];
-                predict_inter(&p, w as i32 - 1, h as i32 - 1, 0, 0, 8, 8, mv, 0, 8, &mut pred);
+                predict_inter(
+                    &p,
+                    &InterBlock { last_x: w as i32 - 1, last_y: h as i32 - 1, x: 0, y: 0, width: 8, height: 8, mv, subsampling: 0, bit_depth: 8 },
+                    &mut pred,
+                );
                 for r in 0..8 {
                     for c in 0..8 {
                         let (x, y) = ((bx + c).clamp(0, w as i32 - 1), (by + r).clamp(0, h as i32 - 1));
diff --git a/crates/av1enc/src/transform.rs b/crates/av1enc/src/transform.rs
index 90042e26a..048bfc0db 100644
--- a/crates/av1enc/src/transform.rs
+++ b/crates/av1enc/src/transform.rs
@@ -4,7 +4,7 @@
 
 use std::sync::OnceLock;
 
-use crate::tables::*;
+use crate::tables::{ADST_ADST, ADST_DCT, COS128_LOOKUP, DCT_ADST, DCT_DCT, TRANSFORM_ROW_SHIFT, TX_WIDTH_LOG2};
 
 #[inline(always)]
 fn round2_64(x: i64, n: u32) -> i32 {
@@ -71,6 +71,12 @@ fn inverse_dct(t: &mut [i32], n: u32, r: u32) {
     for i in 0..len {
         t[i] = copy[brev(n, i)];
     }
+    inverse_dct_initial_stages(t, n, r);
+    inverse_dct_final_stages(t, n, r);
+}
+
+/// Rotate the high-frequency branches before the four-point core.
+fn inverse_dct_initial_stages(t: &mut [i32], n: u32, r: u32) {
     if n >= 5 {
         for i in 0..8 {
             bf(t, 16 + i, 31 - i, 6 + ((brev(3, 7 - i) as i32) << 3), false);
@@ -103,6 +109,10 @@ fn inverse_dct(t: &mut [i32], n: u32, r: u32) {
             }
         }
     }
+}
+
+/// Evaluate the four-point core and merge progressively larger branches.
+fn inverse_dct_final_stages(t: &mut [i32], n: u32, r: u32) {
     for i in 0..2 {
         bf(t, 2 * i, 2 * i + 1, 32 + 16 * i as i32, i == 0);
     }
@@ -454,6 +464,7 @@ pub(crate) fn forward_2d(residual: &[i32], out: &mut [f32], n: usize, tx_type: u
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::tables::{TX_4X4, TX_8X8, TX_16X16, TX_32X32};
 
     /// forward (float) then the normative inverse reproduces the residual: the forward basis
     /// and scale match the decoder's inverse transforms for every supported size and type.
diff --git a/crates/av1enc/src/writer.rs b/crates/av1enc/src/writer.rs
index 54c545fa4..a10bd2e9a 100644
--- a/crates/av1enc/src/writer.rs
+++ b/crates/av1enc/src/writer.rs
@@ -8,7 +8,15 @@ use crate::cdf::Cdfs;
 use crate::decide::{FrameGeom, Leaf, Node, intra_uv_tx_type, scan_for, tx_in_set, tx_set, tx_size_for};
 use crate::loopfilter::LfInfo;
 use crate::symbol::SymbolWriter;
-use crate::tables::*;
+use crate::tables::{
+    ADST_ADST, ADST_DCT, ALTREF_FRAME, ALTREF2_FRAME, BLOCK_8X8, BLOCK_64X64, BR_CDF_SIZE, BWDREF_FRAME, CLASS0_SIZE, COEFF_BASE_CTX_OFFSET, COEFF_BASE_RANGE,
+    D67_PRED, DC_PRED, DCT_ADST, DCT_DCT, DEFAULT_INTRA_FRAME_Y_MODE_CDF, GLOBALMV, GOLDEN_FRAME, INTRA_FRAME, INTRA_MODE_CONTEXT, LAST_FRAME, LAST2_FRAME,
+    LAST3_FRAME, MAG_REF_OFFSET_WITH_TX_CLASS, MAX_ANGLE_DELTA, MAX_REF_MV_STACK_SIZE, MI_HEIGHT_LOG2, MI_WIDTH_LOG2, MV_BORDER, MV_CLASS_0, NEARESTMV, NEARMV,
+    NEWMV, NUM_4X4_BLOCKS_HIGH, NUM_4X4_BLOCKS_WIDE, NUM_BASE_LEVELS, PARTITION_HORZ, PARTITION_HORZ_4, PARTITION_HORZ_A, PARTITION_HORZ_B, PARTITION_NONE,
+    PARTITION_SPLIT, PARTITION_SUBSIZE, PARTITION_VERT, PARTITION_VERT_4, PARTITION_VERT_A, PARTITION_VERT_B, REF_CAT_LEVEL, SIG_REF_DIFF_OFFSET, SIZE_GROUP,
+    SUBSAMPLED_SIZE, TX_32X32, TX_CLASS_2D, TX_HEIGHT, TX_HEIGHT_LOG2, TX_SIZE_SQR, TX_SIZE_SQR_UP, TX_TYPE_INTER_INV_SET3, TX_TYPE_INTRA_INV_SET2, TX_WIDTH,
+    TX_WIDTH_LOG2, V_PRED,
+};
 
 type MvP = [i32; 2];
 
@@ -62,6 +70,8 @@ pub(crate) struct TileWriter<'a> {
     left_dc: [Vec<u8>; 3],
     /// LoopfilterTxSizes per plane (row stride mi_cols + 32).
     lf_tx: [Vec<u8>; 3],
+    /// Scratch for the levels coded so far in `coeffs`.
+    quant: Vec<i32>,
     // current block
     r: usize,
     c: usize,
@@ -114,6 +124,7 @@ impl<'a> TileWriter<'a> {
             left_level: std::array::from_fn(|_| vec![0; g.mi_rows + 64]),
             left_dc: std::array::from_fn(|_| vec![0; g.mi_rows + 64]),
             lf_tx: std::array::from_fn(|_| vec![0; (g.mi_cols + 32) * (g.mi_rows + 32)]),
+            quant: Vec::new(),
             r: 0,
             c: 0,
             bsize: 0,
@@ -181,10 +192,10 @@ impl<'a> TileWriter<'a> {
             self.sw.symbol(partition, cdf);
         } else if has_cols || has_rows {
             assert!(split, "blocks crossing the frame edge are split");
-            let pcdf: Vec<u16> = match bsl {
-                2 => self.cdf.partition_w16[ctx].to_vec(),
-                3 => self.cdf.partition_w32[ctx].to_vec(),
-                _ => self.cdf.partition_w64[ctx].to_vec(),
+            let pcdf: &[u16] = match bsl {
+                2 => &self.cdf.partition_w16[ctx],
+                3 => &self.cdf.partition_w32[ctx],
+                _ => &self.cdf.partition_w64[ctx],
             };
             let pr = |k: usize| pcdf[k] as i32 - if k == 0 { 0 } else { pcdf[k - 1] as i32 };
             let psum = if has_cols {
@@ -455,23 +466,7 @@ impl<'a> TileWriter<'a> {
             }
         } else {
             if plane == 0 {
-                // transform_type( )
-                let set = tx_set(tx_sz, b.is_inter);
-                let t = b.tx_type_y;
-                if set > 0 && self.qidx > 0 {
-                    let sqr = TX_SIZE_SQR[tx_sz] as usize;
-                    if b.is_inter {
-                        // The decision only picks types of this set (DCT_DCT otherwise).
-                        let s = TX_TYPE_INTER_INV_SET3.iter().position(|&v| v as usize == t).unwrap_or_default();
-                        self.sw.symbol(s, &mut self.cdf.inter_tx_type_set3[sqr]);
-                    } else {
-                        let s = TX_TYPE_INTRA_INV_SET2.iter().position(|&v| v as usize == t).unwrap_or_default();
-                        self.sw.symbol(s, &mut self.cdf.intra_tx_type_set2[sqr][b.y_mode]);
-                    }
-                } else {
-                    assert_eq!(t, DCT_DCT);
-                }
-                self.set_tx_types(x4, y4, tx_sz, t);
+                self.write_transform_type(x4, y4, tx_sz, b);
             }
             let plane_tx_type = self.compute_tx_type(plane, tx_sz, x4, y4, b);
             debug_assert!(plane_tx_type == DCT_DCT || matches!(plane_tx_type, ADST_DCT | DCT_ADST | ADST_ADST));
@@ -501,7 +496,9 @@ impl<'a> TileWriter<'a> {
             let height = TX_HEIGHT[tx_sz] as usize;
             let width = 1usize << bwl;
             // Quant[] as the decoder sees it while parsing: the levels coded so far (capped)
-            let mut quant = vec![0i32; width * height];
+            let mut quant = std::mem::take(&mut self.quant);
+            quant.clear();
+            quant.resize(width * height, 0);
             for c in (0..eob).rev() {
                 let pos = scan[c] as usize;
                 let a = levels[pos].unsigned_abs().min(15) as i32;
@@ -526,6 +523,7 @@ impl<'a> TileWriter<'a> {
                 }
                 quant[pos] = a;
             }
+            self.quant = quant;
             for c in 0..eob {
                 let pos = scan[c] as usize;
                 let v = levels[pos];
@@ -571,6 +569,26 @@ impl<'a> TileWriter<'a> {
         }
     }
 
+    fn write_transform_type(&mut self, x4: usize, y4: usize, tx_sz: usize, b: &Leaf) {
+        // transform_type( )
+        let set = tx_set(tx_sz, b.is_inter);
+        let t = b.tx_type_y;
+        if set > 0 && self.qidx > 0 {
+            let sqr = TX_SIZE_SQR[tx_sz] as usize;
+            if b.is_inter {
+                // The decision only picks types of this set (DCT_DCT otherwise).
+                let s = TX_TYPE_INTER_INV_SET3.iter().position(|&v| v as usize == t).unwrap_or_default();
+                self.sw.symbol(s, &mut self.cdf.inter_tx_type_set3[sqr]);
+            } else {
+                let s = TX_TYPE_INTRA_INV_SET2.iter().position(|&v| v as usize == t).unwrap_or_default();
+                self.sw.symbol(s, &mut self.cdf.intra_tx_type_set2[sqr][b.y_mode]);
+            }
+        } else {
+            assert_eq!(t, DCT_DCT);
+        }
+        self.set_tx_types(x4, y4, tx_sz, t);
+    }
+
     fn set_tx_types(&mut self, x4: usize, y4: usize, tx_sz: usize, t: usize) {
         for i in 0..(TX_WIDTH[tx_sz] as usize >> 2) {
             for j in 0..(TX_HEIGHT[tx_sz] as usize >> 2) {
diff --git a/crates/effects/src/channel3d.rs b/crates/effects/src/channel3d.rs
index ea194f6da..08241107c 100644
--- a/crates/effects/src/channel3d.rs
+++ b/crates/effects/src/channel3d.rs
@@ -686,384 +686,4 @@ pub fn specs() -> Vec<EffectSpec> {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::{EffectEnv, EffectHost, LayerPixels, run_fx};
-    use effectcraft_raster::channels3d::crypto_float;
-
-    /// A 20×10 layer: left half object 1 at depth 100, right half object 2 at depth 500; the
-    /// top-right corner is background. Cryptomatte: "left" / "right".
-    struct AuxHost(Arc<AuxChannels>);
-    impl EffectHost for AuxHost {
-        fn layer(&self, _: u64, _: bool) -> Option<LayerPixels> {
-            None
-        }
-        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
-            None
-        }
-        fn aux(&self) -> Option<Arc<AuxChannels>> {
-            Some(self.0.clone())
-        }
-    }
-
-    fn scene() -> AuxHost {
-        let (w, h) = (20usize, 10usize);
-        let mut a = AuxChannels::new(w as u32, h as u32, 1.0);
-        let (mut z, mut id, mut r, mut g) = (vec![0.0; w * h], vec![0.0; w * h], vec![0.0; w * h], vec![0.0; w * h]);
-        let (hl, hr) = (crypto_hash("left"), crypto_hash("right"));
-        for y in 0..h {
-            for x in 0..w {
-                let i = y * w + x;
-                if x >= 15 && y < 3 {
-                    z[i] = BACKGROUND_DEPTH;
-                } else if x < 10 {
-                    z[i] = 100.0;
-                    id[i] = 1.0;
-                    r[i] = crypto_float(hl);
-                    g[i] = 1.0;
-                } else {
-                    z[i] = 500.0;
-                    id[i] = 2.0;
-                    r[i] = crypto_float(hr);
-                    g[i] = 1.0;
-                }
-            }
-        }
-        a.channels = vec![("Z".into(), z), ("ObjectID".into(), id), ("CryptoObject00.R".into(), r), ("CryptoObject00.G".into(), g)];
-        a.manifests = vec![("CryptoObject".into(), vec![("left".into(), hl), ("right".into(), hr)])];
-        AuxHost(Arc::new(a))
-    }
-
-    fn img() -> Image {
-        Image::filled(20, 10, [0.5, 0.5, 0.5, 1.0])
-    }
-
-    fn run(id: &str, vals: &[(&str, Value)], host: &AuxHost) -> Image {
-        run_fx(id, vals, img(), 0.0, EffectEnv { host: Some(host), ..Default::default() }).img
-    }
-
-    #[test]
-    fn passes_through_without_aux_channels() {
-        for s in specs() {
-            let out = run_fx(s.id, &[], img(), 0.0, EffectEnv::default());
-            assert_eq!(out.img.data, img().data, "{}", s.id);
-        }
-    }
-
-    #[test]
-    fn depth_matte_thresholds() {
-        let h = scene();
-        let o = run("ec.3d.depthmatte", &[("depth", num(300.0))], &h);
-        assert_eq!(o.get(2, 5)[3], 0.0);
-        assert_eq!(o.get(12, 5)[3], 1.0);
-        let inv = run("ec.3d.depthmatte", &[("depth", num(300.0)), ("invert", Value::Bool(true))], &h);
-        assert_eq!(inv.get(2, 5)[3], 1.0);
-        assert_eq!(inv.get(12, 5)[3], 0.0);
-        // Feather: a ramp of 800 units centred on 300 → depth 100 at 0.25, 500 at 0.75.
-        let f = run("ec.3d.depthmatte", &[("depth", num(300.0)), ("feather", num(800.0))], &h);
-        assert!((f.get(2, 5)[3] - 0.25).abs() < 1e-5 && (f.get(12, 5)[3] - 0.75).abs() < 1e-5);
-    }
-
-    #[test]
-    fn channel_extract_maps_depth_and_ids() {
-        let h = scene();
-        let o = run("ec.3d.channelextract", &[("blackPoint", num(0.0)), ("whitePoint", num(1000.0))], &h);
-        assert!((o.get(2, 5)[0] - 0.1).abs() < 1e-6 && (o.get(12, 5)[0] - 0.5).abs() < 1e-6);
-        assert_eq!(o.get(17, 1)[0], 1.0);
-        let ids = run("ec.3d.channelextract", &[("channel", Value::Enum(1)), ("whitePoint", num(2.0))], &h);
-        assert_eq!(ids.get(2, 5)[0], 0.5);
-        // Invert Depth Map flips the ramp; without Clamp Output values run past 1.
-        let inv = run("ec.3d.channelextract", &[("blackPoint", num(0.0)), ("whitePoint", num(1000.0)), ("invertDepthMap", Value::Bool(true))], &h);
-        assert!((inv.get(2, 5)[0] - 0.9).abs() < 1e-6);
-        let raw = run("ec.3d.channelextract", &[("blackPoint", num(0.0)), ("whitePoint", num(100.0)), ("clampOutput", Value::Bool(false))], &h);
-        assert!(raw.get(12, 5)[0] > 1.5);
-    }
-
-    #[test]
-    fn id_matte_and_identifier() {
-        let h = scene();
-        let o = run("ec.3d.idmatte", &[("idSelection", num(2.0))], &h);
-        assert_eq!(o.get(2, 5)[3], 0.0);
-        assert_eq!(o.get(12, 5)[3], 1.0);
-        let l = run("ec.3d.identifier", &[("display", Value::Enum(1)), ("id", num(1.0))], &h);
-        assert_eq!(l.get(2, 5)[0], 1.0);
-        assert_eq!(l.get(12, 5)[0], 0.0);
-        let c = run("ec.3d.identifier", &[], &h);
-        assert_ne!(c.get(2, 5), c.get(12, 5));
-    }
-
-    /// The parallel aux image (rank planes resolved once) is bit-identical to the per-pixel
-    /// reduction over `crypto_ranks` it replaces.
-    #[test]
-    fn crypto_aux_image_matches_the_per_pixel_reduction() {
-        let (w, h) = (7u32, 5u32);
-        let n = (w * h) as usize;
-        let mut a = AuxChannels::new(w, h, 1.0);
-        let ids = [crypto_hash("cube"), crypto_hash("sphere"), crypto_hash("ring")].map(effectcraft_raster::channels3d::crypto_float);
-        for (k, ch) in ["00.R", "00.G", "00.B", "00.A", "01.R", "01.G", "01.B", "01.A"].iter().enumerate() {
-            let v: Vec<f32> = (0..n).map(|i| if k % 2 == 0 { ids[(i + k) % 3] } else { ((i * 7 + k * 3) % 11) as f32 / 10.0 }).collect();
-            a.channels.push((format!("CryptoObject{ch}"), v));
-        }
-        let sel = vec![crypto_hash("sphere"), crypto_hash("ring")];
-        let img = crypto_aux_image(&a, "CryptoObject", &sel);
-        for i in 0..n {
-            let ranks = a.crypto_ranks("CryptoObject", i);
-            let m: f32 = ranks.iter().filter(|(id, c)| *c > 0.0 && sel.contains(&id.to_bits())).map(|(_, c)| *c).sum::<f32>().clamp(0.0, 1.0);
-            let mut c = [0.0f32; 3];
-            for (id, cov) in &ranks {
-                let k = id_color(*id);
-                for j in 0..3 {
-                    c[j] += k[j] * cov;
-                }
-            }
-            let want = [c[0], c[1], c[2], m];
-            assert_eq!(img.data[i].map(f32::to_bits), want.map(f32::to_bits), "pixel {i}");
-        }
-    }
-
-    /// The lookup before #473, kept as the reference: the rank channels formatted and searched
-    /// by name for every pixel.
-    fn ranks_by_name(a: &AuxChannels, layer: &str, i: usize) -> Vec<(f32, f32)> {
-        let mut out = vec![];
-        for k in 0.. {
-            let get = |c: &str| a.get(&format!("{layer}{k:02}.{c}"));
-            let (Some(r), Some(g)) = (get("R"), get("G")) else { break };
-            out.push((r[i], g[i]));
-            if let (Some(b), Some(al)) = (get("B"), get("A")) {
-                out.push((b[i], al[i]));
-            }
-        }
-        out
-    }
-
-    /// The reduction before #473 over those ranks: (ID colours, selection coverage).
-    fn reduce_by_name(a: &AuxChannels, layer: &str, sel: &[u32], i: usize) -> ([f32; 3], f32) {
-        let ranks = ranks_by_name(a, layer, i);
-        let m: f32 = ranks.iter().filter(|(id, c)| *c > 0.0 && sel.contains(&id.to_bits())).map(|(_, c)| *c).sum::<f32>().clamp(0.0, 1.0);
-        let mut c = [0.0f32; 3];
-        for (id, cov) in &ranks {
-            let k = id_color(*id);
-            for j in 0..3 {
-                c[j] += k[j] * cov;
-            }
-        }
-        (c, m)
-    }
-
-    /// A 6×2 Cryptomatte layer with awkward values: NaN, ±inf, negative and -0.0 coverage, NaN
-    /// and -0.0 IDs; rank 01 has no B/A pair, rank 02 is missing, so rank 03 (filled with values
-    /// that would change every pixel) must be ignored as before.
-    fn edge_aux(with_rank_after_gap: bool) -> AuxChannels {
-        let (w, h) = (6u32, 2u32);
-        let nan_payload = f32::from_bits(0x7fc0_1234);
-        let (hs, hc) = (crypto_float(crypto_hash("sphere")), crypto_float(crypto_hash("cube")));
-        let cov = [f32::NAN, f32::INFINITY, f32::NEG_INFINITY, -0.5, -0.0, 0.0, 0.25, 1.0, 2.0, f32::MIN_POSITIVE, nan_payload, 0.5];
-        let ids = [hs, f32::NAN, hc, -0.0, 0.0, nan_payload, hs, hc, f32::NAN, hs, hc, -0.0];
-        let rot = |v: &[f32; 12], k: usize| -> Vec<f32> { (0..12).map(|i| v[(i + k) % 12]).collect() };
-        let mut a = AuxChannels::new(w, h, 1.0);
-        let mut push = |n: &str, v: Vec<f32>| a.channels.push((format!("CryptoObject{n}"), v));
-        push("00.R", rot(&ids, 0));
-        push("00.G", rot(&cov, 0));
-        push("00.B", rot(&ids, 3));
-        push("00.A", rot(&cov, 5));
-        push("01.R", rot(&ids, 7));
-        push("01.G", rot(&cov, 2));
-        if with_rank_after_gap {
-            push("03.R", vec![hs; 12]);
-            push("03.G", vec![1.0; 12]);
-            push("03.B", vec![hc; 12]);
-            push("03.A", vec![1.0; 12]);
-        }
-        a
-    }
-
-    /// The memo hands out exactly `id_color`'s bits for every rank and pixel of the edge values
-    /// (NaN IDs with and without a payload, -0.0 and 0.0 are keyed by their bits).
-    #[test]
-    fn id_color_memo_matches_id_color() {
-        let a = edge_aux(true);
-        let planes = a.crypto_rank_planes("CryptoObject");
-        let mut memo = IdColorMemo::default();
-        for i in 0..12 {
-            for (r, (id, _)) in planes.iter().enumerate() {
-                assert_eq!(memo.get(r, id[i]).map(f32::to_bits), id_color(id[i]).map(f32::to_bits), "pixel {i} rank {r}");
-            }
-        }
-    }
-
-    fn edge_selection() -> Vec<u32> {
-        vec![crypto_hash("sphere"), f32::NAN.to_bits(), 0x7fc0_1234, (-0.0f32).to_bits()]
-    }
-
-    /// Edge values give bit-identical results to the lookup by name, the missing B/A pair is
-    /// skipped and a rank after a gap is ignored.
-    #[test]
-    fn crypto_aux_image_is_bit_exact_on_edge_values() {
-        let sel = edge_selection();
-        let a = edge_aux(true);
-        assert_eq!(a.crypto_rank_planes("CryptoObject").len(), 3, "00.R/G, 00.B/A, 01.R/G; not 03 after the gap");
-        let img = crypto_aux_image(&a, "CryptoObject", &sel);
-        let without_gap_rank = crypto_aux_image(&edge_aux(false), "CryptoObject", &sel);
-        for i in 0..12 {
-            let (c, m) = reduce_by_name(&a, "CryptoObject", &sel, i);
-            let want = [c[0], c[1], c[2], m];
-            assert_eq!(img.data[i].map(f32::to_bits), want.map(f32::to_bits), "pixel {i}");
-            assert_eq!(img.data[i].map(f32::to_bits), without_gap_rank.data[i].map(f32::to_bits), "pixel {i}: the rank after the gap was used");
-        }
-    }
-
-    /// Without the ID colours the matte (A) is bit-identical and the RGB is 0, on the edge values.
-    #[test]
-    fn crypto_aux_image_without_colors_keeps_the_matte() {
-        let a = edge_aux(true);
-        let sel = edge_selection();
-        let full = crypto_aux_image(&a, "CryptoObject", &sel);
-        let matte = crypto_aux_image_with(&a, "CryptoObject", &sel, CryptoAux::MatteOnly);
-        for (f, m) in full.data.iter().zip(&matte.data) {
-            assert_eq!(f[3].to_bits(), m[3].to_bits());
-            assert_eq!(m[..3], [0.0; 3]);
-        }
-    }
-
-    /// Only the Colors display without Matte Only reads the ID colours.
-    #[test]
-    fn crypto_aux_for_display_reads_colors_only_for_the_colors_display() {
-        assert_eq!(CryptoAux::for_display(0, false), CryptoAux::ColorsAndMatte);
-        assert_eq!(CryptoAux::for_display(0, true), CryptoAux::MatteOnly);
-        for display in [1, 2, 3, u32::MAX] {
-            for matte_only in [false, true] {
-                assert_eq!(CryptoAux::for_display(display, matte_only), CryptoAux::MatteOnly, "display {display}");
-            }
-        }
-    }
-
-    /// The CPU effect on a 20×10 layer over the 6×2 edge aux: pixels inside the aux area match
-    /// the lookup by name bit for bit in every display mode, pixels outside it (no aux index)
-    /// get an empty matte and no ID colour.
-    #[test]
-    fn cryptomatte_cpu_path_is_bit_exact_inside_and_outside_the_aux_area() {
-        let a = edge_aux(true);
-        let host = AuxHost(Arc::new(a.clone()));
-        let names = "sphere, <7fc00000>, <7fc01234>, <80000000>";
-        assert_eq!(selection_hashes(names, None), edge_selection());
-        let src = img().data[0];
-        for (display, matte_only) in [(0, false), (1, false), (2, false), (0, true)] {
-            let out = run(
-                "ec.3d.cryptomatte",
-                &[("selection", Value::Str(names.into())), ("display", Value::Enum(display)), ("matteOnly", Value::Bool(matte_only))],
-                &host,
-            );
-            let expect = |c: [f32; 3], m: f32| -> [f32; 4] {
-                if matte_only {
-                    return [m; 4];
-                }
-                match display {
-                    0 => {
-                        let c = c.map(|v| v * (1.0 - 0.5 * m) + 0.5 * m);
-                        [c[0], c[1], c[2], 1.0]
-                    }
-                    1 => src.map(|v| v * m),
-                    _ => [src[0] * (1.0 - 0.5 * m) + 0.5 * m * src[3], src[1] * (1.0 - 0.5 * m) + 0.5 * m * src[3], src[2] * (1.0 - 0.5 * m), src[3]],
-                }
-            };
-            for (x, y) in [(0u32, 0u32), (1, 0), (5, 0), (0, 1), (3, 1), (5, 1)] {
-                let (c, m) = reduce_by_name(&a, "CryptoObject", &edge_selection(), (y * 6 + x) as usize);
-                assert_eq!(
-                    out.get(x as i64, y as i64).map(f32::to_bits),
-                    expect(c, m).map(f32::to_bits),
-                    "display {display} matteOnly {matte_only} at ({x}, {y})"
-                );
-            }
-            for (x, y) in [(6u32, 0u32), (19, 0), (0, 2), (12, 9)] {
-                assert_eq!(
-                    out.get(x as i64, y as i64).map(f32::to_bits),
-                    expect([0.0; 3], 0.0).map(f32::to_bits),
-                    "display {display} matteOnly {matte_only} outside the aux at ({x}, {y})"
-                );
-            }
-        }
-    }
-
-    #[test]
-    fn cryptomatte_selects_by_name_and_wildcard() {
-        let h = scene();
-        let m = run("ec.3d.cryptomatte", &[("selection", Value::Str("right".into())), ("matteOnly", Value::Bool(true))], &h);
-        assert_eq!(m.get(2, 5)[3], 0.0);
-        assert_eq!(m.get(12, 5)[3], 1.0);
-        let w = run("ec.3d.cryptomatte", &[("selection", Value::Str("l*".into())), ("display", Value::Enum(1))], &h);
-        assert_eq!(w.get(2, 5)[3], 1.0);
-        assert_eq!(w.get(12, 5)[3], 0.0);
-        assert!(wild("*ight", "right") && wild("r*t", "right") && !wild("x*", "right"));
-        let hex = format!("<{:08x}>", crypto_hash("left"));
-        assert_eq!(selection_hashes(&hex, None), vec![crypto_hash("left")]);
-    }
-
-    /// #473: a name with a comma in it (Blender allows `Green, Glossy`) is selected when it is
-    /// quoted or its comma escaped, instead of being cut into two names that match nothing.
-    #[test]
-    fn cryptomatte_selection_keeps_quoted_names_with_commas_whole() {
-        let manifest = vec![("Green, Glossy".to_string(), 7), ("Green".to_string(), 1), ("Glossy".to_string(), 2), ("ring".to_string(), 3)];
-        let m = Some(manifest.as_slice());
-        assert_eq!(selection_hashes(r#""Green, Glossy""#, m), vec![7]);
-        assert_eq!(selection_hashes("'Green, Glossy', ring", m), vec![7, 3]);
-        assert_eq!(selection_hashes(r"Green\, Glossy", m), vec![7]);
-        assert_eq!(selection_hashes(r#"ring , "Green, Glossy""#, m), vec![3, 7]);
-        // Without a manifest the whole name is hashed.
-        assert_eq!(selection_hashes(r#""Green, Glossy""#, None), vec![crypto_hash("Green, Glossy")]);
-        // Plain lists, apostrophes inside names and an unclosed quote still parse.
-        assert_eq!(selection_hashes("Green, Glossy", m), vec![1, 2]);
-        assert_eq!(selection_names("Bob's mat, ring"), vec!["Bob's mat", "ring"]);
-        assert_eq!(selection_names(r#""Green, Glossy"#), vec!["Green, Glossy"]);
-        assert_eq!(selection_names(r#"say \"hi\""#), vec![r#"say "hi""#]);
-    }
-
-    #[test]
-    fn fog_and_depth_of_field_follow_depth() {
-        let h = scene();
-        let f = run("ec.3d.fog3d", &[("fogColor", col(1.0, 0.0, 0.0)), ("fogEndDepth", num(1000.0)), ("scatteringDensity", num(0.0))], &h);
-        // Linear fog: 10 % at depth 100, 50 % at 500, full on the background.
-        assert!((f.get(2, 5)[0] - 0.55).abs() < 1e-4, "{:?}", f.get(2, 5));
-        assert!((f.get(12, 5)[0] - 0.75).abs() < 1e-4);
-        assert!((f.get(17, 1)[0] - 1.0).abs() < 1e-4 && f.get(17, 1)[1] < 1e-4);
-        assert!((dof_radius(100.0, 100.0, 0.0, 10.0, 50.0)).abs() < 1e-6);
-        assert!((dof_radius(200.0, 100.0, 0.0, 10.0, 50.0) - 10.0).abs() < 1e-6);
-        assert_eq!(dof_radius(140.0, 100.0, 100.0, 10.0, 50.0), 0.0);
-        // A sharp edge at the far object blurs when focused near.
-        let mut pic = Image::new(20, 10);
-        for y in 0..10 {
-            for x in 0..20 {
-                let v = if x % 2 == 0 { 1.0 } else { 0.0 };
-                pic.set(x, y, [v, v, v, 1.0]);
-            }
-        }
-        let env = EffectEnv { host: Some(&h), ..Default::default() };
-        let d = run_fx("ec.3d.depthoffield", &[("focalPlane", num(100.0)), ("maximumRadius", num(4.0))], pic.clone(), 0.0, env).img;
-        assert_eq!(d.get(4, 5), pic.get(4, 5));
-        assert!((d.get(12, 5)[0] - 0.5).abs() < 0.3 && d.get(12, 5) != pic.get(12, 5));
-    }
-
-    #[test]
-    fn extractor_maps_named_channels() {
-        let h = scene();
-        let o = run("ec.3d.extractor", &[("red", Value::Str("Z".into())), ("whitePoint", num(1000.0))], &h);
-        assert!((o.get(2, 5)[0] - 0.1).abs() < 1e-6);
-        assert!((o.get(2, 5)[1] - 0.0005).abs() < 1e-6);
-        // Without aux: the layer's own channels can be swapped.
-        let s = run_fx("ec.3d.extractor", &[("red", Value::Str("A".into()))], Image::filled(2, 2, [0.2, 0.3, 0.4, 1.0]), 0.0, EffectEnv::default());
-        assert_eq!(s.img.get(0, 0), [1.0, 0.3, 0.4, 1.0]);
-    }
-
-    #[test]
-    fn channel_extract_antialias_averages_sub_pixels() {
-        // Depth at twice the layer resolution, alternating 0 / 1000 per aux column.
-        let mut a = AuxChannels::new(40, 20, 2.0);
-        a.channels = vec![("Z".into(), (0..800).map(|i| if i % 2 == 0 { 0.0 } else { 1000.0 }).collect())];
-        let host = AuxHost(Arc::new(a));
-        let vals = [("blackPoint", num(0.0)), ("whitePoint", num(1000.0))];
-        let hard = run("ec.3d.channelextract", &vals, &host);
-        let v = hard.get(5, 5)[0];
-        assert!(v == 0.0 || v == 1.0, "{v}");
-        let soft = run("ec.3d.channelextract", &[vals.as_slice(), &[("antialias", Value::Bool(true))]].concat(), &host);
-        assert!((soft.get(5, 5)[0] - 0.5).abs() < 1e-5, "{:?}", soft.get(5, 5));
-    }
-}
+mod tests;
diff --git a/crates/effects/src/channel3d/tests.rs b/crates/effects/src/channel3d/tests.rs
new file mode 100644
index 000000000..4fc84440e
--- /dev/null
+++ b/crates/effects/src/channel3d/tests.rs
@@ -0,0 +1,375 @@
+use super::*;
+use crate::{EffectEnv, EffectHost, LayerPixels, run_fx};
+use effectcraft_raster::channels3d::crypto_float;
+
+/// A 20×10 layer: left half object 1 at depth 100, right half object 2 at depth 500; the
+/// top-right corner is background. Cryptomatte: "left" / "right".
+struct AuxHost(Arc<AuxChannels>);
+impl EffectHost for AuxHost {
+    fn layer(&self, _: u64, _: bool) -> Option<LayerPixels> {
+        None
+    }
+    fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+        None
+    }
+    fn aux(&self) -> Option<Arc<AuxChannels>> {
+        Some(self.0.clone())
+    }
+}
+
+fn scene() -> AuxHost {
+    let (w, h) = (20usize, 10usize);
+    let mut a = AuxChannels::new(w as u32, h as u32, 1.0);
+    let (mut z, mut id, mut r, mut g) = (vec![0.0; w * h], vec![0.0; w * h], vec![0.0; w * h], vec![0.0; w * h]);
+    let (hl, hr) = (crypto_hash("left"), crypto_hash("right"));
+    for y in 0..h {
+        for x in 0..w {
+            let i = y * w + x;
+            if x >= 15 && y < 3 {
+                z[i] = BACKGROUND_DEPTH;
+            } else if x < 10 {
+                z[i] = 100.0;
+                id[i] = 1.0;
+                r[i] = crypto_float(hl);
+                g[i] = 1.0;
+            } else {
+                z[i] = 500.0;
+                id[i] = 2.0;
+                r[i] = crypto_float(hr);
+                g[i] = 1.0;
+            }
+        }
+    }
+    a.channels = vec![("Z".into(), z), ("ObjectID".into(), id), ("CryptoObject00.R".into(), r), ("CryptoObject00.G".into(), g)];
+    a.manifests = vec![("CryptoObject".into(), vec![("left".into(), hl), ("right".into(), hr)])];
+    AuxHost(Arc::new(a))
+}
+
+fn img() -> Image {
+    Image::filled(20, 10, [0.5, 0.5, 0.5, 1.0])
+}
+
+fn run(id: &str, vals: &[(&str, Value)], host: &AuxHost) -> Image {
+    run_fx(id, vals, img(), 0.0, EffectEnv { host: Some(host), ..Default::default() }).img
+}
+
+#[test]
+fn passes_through_without_aux_channels() {
+    for s in specs() {
+        let out = run_fx(s.id, &[], img(), 0.0, EffectEnv::default());
+        assert_eq!(out.img.data, img().data, "{}", s.id);
+    }
+}
+
+#[test]
+fn depth_matte_thresholds() {
+    let h = scene();
+    let o = run("ec.3d.depthmatte", &[("depth", num(300.0))], &h);
+    assert_eq!(o.get(2, 5)[3], 0.0);
+    assert_eq!(o.get(12, 5)[3], 1.0);
+    let inv = run("ec.3d.depthmatte", &[("depth", num(300.0)), ("invert", Value::Bool(true))], &h);
+    assert_eq!(inv.get(2, 5)[3], 1.0);
+    assert_eq!(inv.get(12, 5)[3], 0.0);
+    // Feather: a ramp of 800 units centred on 300 → depth 100 at 0.25, 500 at 0.75.
+    let f = run("ec.3d.depthmatte", &[("depth", num(300.0)), ("feather", num(800.0))], &h);
+    assert!((f.get(2, 5)[3] - 0.25).abs() < 1e-5 && (f.get(12, 5)[3] - 0.75).abs() < 1e-5);
+}
+
+#[test]
+fn channel_extract_maps_depth_and_ids() {
+    let h = scene();
+    let o = run("ec.3d.channelextract", &[("blackPoint", num(0.0)), ("whitePoint", num(1000.0))], &h);
+    assert!((o.get(2, 5)[0] - 0.1).abs() < 1e-6 && (o.get(12, 5)[0] - 0.5).abs() < 1e-6);
+    assert_eq!(o.get(17, 1)[0], 1.0);
+    let ids = run("ec.3d.channelextract", &[("channel", Value::Enum(1)), ("whitePoint", num(2.0))], &h);
+    assert_eq!(ids.get(2, 5)[0], 0.5);
+    // Invert Depth Map flips the ramp; without Clamp Output values run past 1.
+    let inv = run("ec.3d.channelextract", &[("blackPoint", num(0.0)), ("whitePoint", num(1000.0)), ("invertDepthMap", Value::Bool(true))], &h);
+    assert!((inv.get(2, 5)[0] - 0.9).abs() < 1e-6);
+    let raw = run("ec.3d.channelextract", &[("blackPoint", num(0.0)), ("whitePoint", num(100.0)), ("clampOutput", Value::Bool(false))], &h);
+    assert!(raw.get(12, 5)[0] > 1.5);
+}
+
+#[test]
+fn id_matte_and_identifier() {
+    let h = scene();
+    let o = run("ec.3d.idmatte", &[("idSelection", num(2.0))], &h);
+    assert_eq!(o.get(2, 5)[3], 0.0);
+    assert_eq!(o.get(12, 5)[3], 1.0);
+    let l = run("ec.3d.identifier", &[("display", Value::Enum(1)), ("id", num(1.0))], &h);
+    assert_eq!(l.get(2, 5)[0], 1.0);
+    assert_eq!(l.get(12, 5)[0], 0.0);
+    let c = run("ec.3d.identifier", &[], &h);
+    assert_ne!(c.get(2, 5), c.get(12, 5));
+}
+
+/// The parallel aux image (rank planes resolved once) is bit-identical to the per-pixel
+/// reduction over `crypto_ranks` it replaces.
+#[test]
+fn crypto_aux_image_matches_the_per_pixel_reduction() {
+    let (w, h) = (7u32, 5u32);
+    let n = (w * h) as usize;
+    let mut a = AuxChannels::new(w, h, 1.0);
+    let ids = [crypto_hash("cube"), crypto_hash("sphere"), crypto_hash("ring")].map(effectcraft_raster::channels3d::crypto_float);
+    for (k, ch) in ["00.R", "00.G", "00.B", "00.A", "01.R", "01.G", "01.B", "01.A"].iter().enumerate() {
+        let v: Vec<f32> = (0..n).map(|i| if k % 2 == 0 { ids[(i + k) % 3] } else { ((i * 7 + k * 3) % 11) as f32 / 10.0 }).collect();
+        a.channels.push((format!("CryptoObject{ch}"), v));
+    }
+    let sel = vec![crypto_hash("sphere"), crypto_hash("ring")];
+    let img = crypto_aux_image(&a, "CryptoObject", &sel);
+    for i in 0..n {
+        let ranks = a.crypto_ranks("CryptoObject", i);
+        let m: f32 = ranks.iter().filter(|(id, c)| *c > 0.0 && sel.contains(&id.to_bits())).map(|(_, c)| *c).sum::<f32>().clamp(0.0, 1.0);
+        let mut c = [0.0f32; 3];
+        for (id, cov) in &ranks {
+            let k = id_color(*id);
+            for j in 0..3 {
+                c[j] += k[j] * cov;
+            }
+        }
+        let want = [c[0], c[1], c[2], m];
+        assert_eq!(img.data[i].map(f32::to_bits), want.map(f32::to_bits), "pixel {i}");
+    }
+}
+
+/// The lookup before #473, kept as the reference: the rank channels formatted and searched
+/// by name for every pixel.
+fn ranks_by_name(a: &AuxChannels, layer: &str, i: usize) -> Vec<(f32, f32)> {
+    let mut out = vec![];
+    for k in 0.. {
+        let get = |c: &str| a.get(&format!("{layer}{k:02}.{c}"));
+        let (Some(r), Some(g)) = (get("R"), get("G")) else { break };
+        out.push((r[i], g[i]));
+        if let (Some(b), Some(al)) = (get("B"), get("A")) {
+            out.push((b[i], al[i]));
+        }
+    }
+    out
+}
+
+/// The reduction before #473 over those ranks: (ID colours, selection coverage).
+fn reduce_by_name(a: &AuxChannels, layer: &str, sel: &[u32], i: usize) -> ([f32; 3], f32) {
+    let ranks = ranks_by_name(a, layer, i);
+    let m: f32 = ranks.iter().filter(|(id, c)| *c > 0.0 && sel.contains(&id.to_bits())).map(|(_, c)| *c).sum::<f32>().clamp(0.0, 1.0);
+    let mut c = [0.0f32; 3];
+    for (id, cov) in &ranks {
+        let k = id_color(*id);
+        for j in 0..3 {
+            c[j] += k[j] * cov;
+        }
+    }
+    (c, m)
+}
+
+/// A 6×2 Cryptomatte layer with awkward values: NaN, ±inf, negative and -0.0 coverage, NaN
+/// and -0.0 IDs; rank 01 has no B/A pair, rank 02 is missing, so rank 03 (filled with values
+/// that would change every pixel) must be ignored as before.
+fn edge_aux(with_rank_after_gap: bool) -> AuxChannels {
+    let (w, h) = (6u32, 2u32);
+    let nan_payload = f32::from_bits(0x7fc0_1234);
+    let (hs, hc) = (crypto_float(crypto_hash("sphere")), crypto_float(crypto_hash("cube")));
+    let cov = [f32::NAN, f32::INFINITY, f32::NEG_INFINITY, -0.5, -0.0, 0.0, 0.25, 1.0, 2.0, f32::MIN_POSITIVE, nan_payload, 0.5];
+    let ids = [hs, f32::NAN, hc, -0.0, 0.0, nan_payload, hs, hc, f32::NAN, hs, hc, -0.0];
+    let rot = |v: &[f32; 12], k: usize| -> Vec<f32> { (0..12).map(|i| v[(i + k) % 12]).collect() };
+    let mut a = AuxChannels::new(w, h, 1.0);
+    let mut push = |n: &str, v: Vec<f32>| a.channels.push((format!("CryptoObject{n}"), v));
+    push("00.R", rot(&ids, 0));
+    push("00.G", rot(&cov, 0));
+    push("00.B", rot(&ids, 3));
+    push("00.A", rot(&cov, 5));
+    push("01.R", rot(&ids, 7));
+    push("01.G", rot(&cov, 2));
+    if with_rank_after_gap {
+        push("03.R", vec![hs; 12]);
+        push("03.G", vec![1.0; 12]);
+        push("03.B", vec![hc; 12]);
+        push("03.A", vec![1.0; 12]);
+    }
+    a
+}
+
+/// The memo hands out exactly `id_color`'s bits for every rank and pixel of the edge values
+/// (NaN IDs with and without a payload, -0.0 and 0.0 are keyed by their bits).
+#[test]
+fn id_color_memo_matches_id_color() {
+    let a = edge_aux(true);
+    let planes = a.crypto_rank_planes("CryptoObject");
+    let mut memo = IdColorMemo::default();
+    for i in 0..12 {
+        for (r, (id, _)) in planes.iter().enumerate() {
+            assert_eq!(memo.get(r, id[i]).map(f32::to_bits), id_color(id[i]).map(f32::to_bits), "pixel {i} rank {r}");
+        }
+    }
+}
+
+fn edge_selection() -> Vec<u32> {
+    vec![crypto_hash("sphere"), f32::NAN.to_bits(), 0x7fc0_1234, (-0.0f32).to_bits()]
+}
+
+/// Edge values give bit-identical results to the lookup by name, the missing B/A pair is
+/// skipped and a rank after a gap is ignored.
+#[test]
+fn crypto_aux_image_is_bit_exact_on_edge_values() {
+    let sel = edge_selection();
+    let a = edge_aux(true);
+    assert_eq!(a.crypto_rank_planes("CryptoObject").len(), 3, "00.R/G, 00.B/A, 01.R/G; not 03 after the gap");
+    let img = crypto_aux_image(&a, "CryptoObject", &sel);
+    let without_gap_rank = crypto_aux_image(&edge_aux(false), "CryptoObject", &sel);
+    for i in 0..12 {
+        let (c, m) = reduce_by_name(&a, "CryptoObject", &sel, i);
+        let want = [c[0], c[1], c[2], m];
+        assert_eq!(img.data[i].map(f32::to_bits), want.map(f32::to_bits), "pixel {i}");
+        assert_eq!(img.data[i].map(f32::to_bits), without_gap_rank.data[i].map(f32::to_bits), "pixel {i}: the rank after the gap was used");
+    }
+}
+
+/// Without the ID colours the matte (A) is bit-identical and the RGB is 0, on the edge values.
+#[test]
+fn crypto_aux_image_without_colors_keeps_the_matte() {
+    let a = edge_aux(true);
+    let sel = edge_selection();
+    let full = crypto_aux_image(&a, "CryptoObject", &sel);
+    let matte = crypto_aux_image_with(&a, "CryptoObject", &sel, CryptoAux::MatteOnly);
+    for (f, m) in full.data.iter().zip(&matte.data) {
+        assert_eq!(f[3].to_bits(), m[3].to_bits());
+        assert_eq!(m[..3], [0.0; 3]);
+    }
+}
+
+/// Only the Colors display without Matte Only reads the ID colours.
+#[test]
+fn crypto_aux_for_display_reads_colors_only_for_the_colors_display() {
+    assert_eq!(CryptoAux::for_display(0, false), CryptoAux::ColorsAndMatte);
+    assert_eq!(CryptoAux::for_display(0, true), CryptoAux::MatteOnly);
+    for display in [1, 2, 3, u32::MAX] {
+        for matte_only in [false, true] {
+            assert_eq!(CryptoAux::for_display(display, matte_only), CryptoAux::MatteOnly, "display {display}");
+        }
+    }
+}
+
+/// The CPU effect on a 20×10 layer over the 6×2 edge aux: pixels inside the aux area match
+/// the lookup by name bit for bit in every display mode, pixels outside it (no aux index)
+/// get an empty matte and no ID colour.
+#[test]
+fn cryptomatte_cpu_path_is_bit_exact_inside_and_outside_the_aux_area() {
+    let a = edge_aux(true);
+    let host = AuxHost(Arc::new(a.clone()));
+    let names = "sphere, <7fc00000>, <7fc01234>, <80000000>";
+    assert_eq!(selection_hashes(names, None), edge_selection());
+    let src = img().data[0];
+    for (display, matte_only) in [(0, false), (1, false), (2, false), (0, true)] {
+        let out = run(
+            "ec.3d.cryptomatte",
+            &[("selection", Value::Str(names.into())), ("display", Value::Enum(display)), ("matteOnly", Value::Bool(matte_only))],
+            &host,
+        );
+        let expect = |c: [f32; 3], m: f32| -> [f32; 4] {
+            if matte_only {
+                return [m; 4];
+            }
+            match display {
+                0 => {
+                    let c = c.map(|v| v * (1.0 - 0.5 * m) + 0.5 * m);
+                    [c[0], c[1], c[2], 1.0]
+                }
+                1 => src.map(|v| v * m),
+                _ => [src[0] * (1.0 - 0.5 * m) + 0.5 * m * src[3], src[1] * (1.0 - 0.5 * m) + 0.5 * m * src[3], src[2] * (1.0 - 0.5 * m), src[3]],
+            }
+        };
+        for (x, y) in [(0u32, 0u32), (1, 0), (5, 0), (0, 1), (3, 1), (5, 1)] {
+            let (c, m) = reduce_by_name(&a, "CryptoObject", &edge_selection(), (y * 6 + x) as usize);
+            assert_eq!(out.get(x as i64, y as i64).map(f32::to_bits), expect(c, m).map(f32::to_bits), "display {display} matteOnly {matte_only} at ({x}, {y})");
+        }
+        for (x, y) in [(6u32, 0u32), (19, 0), (0, 2), (12, 9)] {
+            assert_eq!(
+                out.get(x as i64, y as i64).map(f32::to_bits),
+                expect([0.0; 3], 0.0).map(f32::to_bits),
+                "display {display} matteOnly {matte_only} outside the aux at ({x}, {y})"
+            );
+        }
+    }
+}
+
+#[test]
+fn cryptomatte_selects_by_name_and_wildcard() {
+    let h = scene();
+    let m = run("ec.3d.cryptomatte", &[("selection", Value::Str("right".into())), ("matteOnly", Value::Bool(true))], &h);
+    assert_eq!(m.get(2, 5)[3], 0.0);
+    assert_eq!(m.get(12, 5)[3], 1.0);
+    let w = run("ec.3d.cryptomatte", &[("selection", Value::Str("l*".into())), ("display", Value::Enum(1))], &h);
+    assert_eq!(w.get(2, 5)[3], 1.0);
+    assert_eq!(w.get(12, 5)[3], 0.0);
+    assert!(wild("*ight", "right") && wild("r*t", "right") && !wild("x*", "right"));
+    let hex = format!("<{:08x}>", crypto_hash("left"));
+    assert_eq!(selection_hashes(&hex, None), vec![crypto_hash("left")]);
+}
+
+/// #473: a name with a comma in it (Blender allows `Green, Glossy`) is selected when it is
+/// quoted or its comma escaped, instead of being cut into two names that match nothing.
+#[test]
+fn cryptomatte_selection_keeps_quoted_names_with_commas_whole() {
+    let manifest = vec![("Green, Glossy".to_string(), 7), ("Green".to_string(), 1), ("Glossy".to_string(), 2), ("ring".to_string(), 3)];
+    let m = Some(manifest.as_slice());
+    assert_eq!(selection_hashes(r#""Green, Glossy""#, m), vec![7]);
+    assert_eq!(selection_hashes("'Green, Glossy', ring", m), vec![7, 3]);
+    assert_eq!(selection_hashes(r"Green\, Glossy", m), vec![7]);
+    assert_eq!(selection_hashes(r#"ring , "Green, Glossy""#, m), vec![3, 7]);
+    // Without a manifest the whole name is hashed.
+    assert_eq!(selection_hashes(r#""Green, Glossy""#, None), vec![crypto_hash("Green, Glossy")]);
+    // Plain lists, apostrophes inside names and an unclosed quote still parse.
+    assert_eq!(selection_hashes("Green, Glossy", m), vec![1, 2]);
+    assert_eq!(selection_names("Bob's mat, ring"), vec!["Bob's mat", "ring"]);
+    assert_eq!(selection_names(r#""Green, Glossy"#), vec!["Green, Glossy"]);
+    assert_eq!(selection_names(r#"say \"hi\""#), vec![r#"say "hi""#]);
+}
+
+#[test]
+fn fog_and_depth_of_field_follow_depth() {
+    let h = scene();
+    let f = run("ec.3d.fog3d", &[("fogColor", col(1.0, 0.0, 0.0)), ("fogEndDepth", num(1000.0)), ("scatteringDensity", num(0.0))], &h);
+    // Linear fog: 10 % at depth 100, 50 % at 500, full on the background.
+    assert!((f.get(2, 5)[0] - 0.55).abs() < 1e-4, "{:?}", f.get(2, 5));
+    assert!((f.get(12, 5)[0] - 0.75).abs() < 1e-4);
+    assert!((f.get(17, 1)[0] - 1.0).abs() < 1e-4 && f.get(17, 1)[1] < 1e-4);
+    assert!((dof_radius(100.0, 100.0, 0.0, 10.0, 50.0)).abs() < 1e-6);
+    assert!((dof_radius(200.0, 100.0, 0.0, 10.0, 50.0) - 10.0).abs() < 1e-6);
+    assert_eq!(dof_radius(140.0, 100.0, 100.0, 10.0, 50.0), 0.0);
+    // A sharp edge at the far object blurs when focused near.
+    let mut pic = Image::new(20, 10);
+    for y in 0..10 {
+        for x in 0..20 {
+            let v = if x % 2 == 0 { 1.0 } else { 0.0 };
+            pic.set(x, y, [v, v, v, 1.0]);
+        }
+    }
+    let env = EffectEnv { host: Some(&h), ..Default::default() };
+    let d = run_fx("ec.3d.depthoffield", &[("focalPlane", num(100.0)), ("maximumRadius", num(4.0))], pic.clone(), 0.0, env).img;
+    assert_eq!(d.get(4, 5), pic.get(4, 5));
+    assert!((d.get(12, 5)[0] - 0.5).abs() < 0.3 && d.get(12, 5) != pic.get(12, 5));
+}
+
+#[test]
+fn extractor_maps_named_channels() {
+    let h = scene();
+    let o = run("ec.3d.extractor", &[("red", Value::Str("Z".into())), ("whitePoint", num(1000.0))], &h);
+    assert!((o.get(2, 5)[0] - 0.1).abs() < 1e-6);
+    assert!((o.get(2, 5)[1] - 0.0005).abs() < 1e-6);
+    // Without aux: the layer's own channels can be swapped.
+    let s = run_fx("ec.3d.extractor", &[("red", Value::Str("A".into()))], Image::filled(2, 2, [0.2, 0.3, 0.4, 1.0]), 0.0, EffectEnv::default());
+    assert_eq!(s.img.get(0, 0), [1.0, 0.3, 0.4, 1.0]);
+}
+
+#[test]
+fn channel_extract_antialias_averages_sub_pixels() {
+    // Depth at twice the layer resolution, alternating 0 / 1000 per aux column.
+    let mut a = AuxChannels::new(40, 20, 2.0);
+    a.channels = vec![("Z".into(), (0..800).map(|i| if i % 2 == 0 { 0.0 } else { 1000.0 }).collect())];
+    let host = AuxHost(Arc::new(a));
+    let vals = [("blackPoint", num(0.0)), ("whitePoint", num(1000.0))];
+    let hard = run("ec.3d.channelextract", &vals, &host);
+    let v = hard.get(5, 5)[0];
+    assert!(v == 0.0 || v == 1.0, "{v}");
+    let soft = run("ec.3d.channelextract", &[vals.as_slice(), &[("antialias", Value::Bool(true))]].concat(), &host);
+    assert!((soft.get(5, 5)[0] - 0.5).abs() < 1e-5, "{:?}", soft.get(5, 5));
+}
diff --git a/crates/effects/src/color2.rs b/crates/effects/src/color2.rs
index 9547fd775..25203cd7a 100644
--- a/crates/effects/src/color2.rs
+++ b/crates/effects/src/color2.rs
@@ -1129,347 +1129,4 @@ pub fn specs() -> Vec<EffectSpec> {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::{Params, find};
-
-    fn run(id: &str, img: &Image, over: &[(&str, Value)]) -> Image {
-        let s = find(id).unwrap();
-        let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-        for (k, v) in over {
-            params.values.insert(k.to_string(), v.clone());
-        }
-        let ctx =
-            EffectCtx { params: &params, time: 0.0, layer_size: [img.width as f64, img.height as f64], seed: 1, adjustment: false, env: Default::default() };
-        (s.render)(&ctx, Buf { img: img.clone(), offset: [0.0, 0.0], scale: 1.0 }).img
-    }
-
-    fn ramp() -> Image {
-        let mut img = Image::new(16, 8);
-        for y in 0..8 {
-            for x in 0..16 {
-                let v = x as f32 / 15.0;
-                let a = if y == 0 { 0.5 } else { 1.0 };
-                img.set(x, y, [v * a, (1.0 - v) * a, 0.3 * a, a]);
-            }
-        }
-        img
-    }
-
-    fn close(a: &Image, b: &Image, eps: f32) -> bool {
-        a.data.iter().zip(&b.data).all(|(p, q)| (0..4).all(|i| (p[i] - q[i]).abs() <= eps))
-    }
-
-    #[test]
-    fn curve_parsing() {
-        assert!(Curve::parse("0,0 1,1").is_none());
-        assert!(Curve::parse("garbage").is_none());
-        let c = Curve::parse("1,1; 0,0 0.5,0.7").unwrap();
-        assert_eq!(c.xs, vec![0.0, 0.5, 1.0]);
-        assert!((c.eval(0.5) - 0.7).abs() < 1e-3);
-        // Monotone: never decreases.
-        let mut last = -1.0;
-        for i in 0..=100 {
-            let v = c.eval(i as f32 / 100.0);
-            assert!(v >= last - 1e-6);
-            last = v;
-        }
-    }
-
-    #[test]
-    fn curves_identity_is_identity() {
-        let img = ramp();
-        assert_eq!(run("ec.color.curves", &img, &[]), img);
-        let explicit = run("ec.color.curves", &img, &[("rgb", Value::Str("0,0 0.25,0.25 1,1".into()))]);
-        assert!(close(&explicit, &img, 1e-4));
-    }
-
-    #[test]
-    fn curves_midpoint_brightens() {
-        let img = Image::filled(4, 4, [0.5, 0.5, 0.5, 1.0]);
-        let out = run("ec.color.curves", &img, &[("rgb", Value::Str("0,0 0.5,0.75 1,1".into()))]);
-        assert!((out.data[0][0] - 0.75).abs() < 1e-3);
-        let red = run("ec.color.curves", &img, &[("red", Value::Str("0,1 1,1".into()))]);
-        assert!((red.data[0][0] - 1.0).abs() < 1e-4 && (red.data[0][1] - 0.5).abs() < 1e-6);
-    }
-
-    /// After Effects 2026, 32 bpc project, Levels (Individual Controls) with RGB Input Black 0.1,
-    /// Input White 0.9, Gamma 1.5, Output Black 0.05, Output White 0.95, Red Gamma 0.8, Green
-    /// Input White 0.8, Blue Output Black 0.2, both clips "Off for 32 bpc Color", on grey steps:
-    /// the channel controls run first, nothing clips (8-bit captures clamp the results).
-    #[test]
-    fn levels_ic_matches_after_effects_in_32_bpc() {
-        let steps = [0, 16, 32, 64, 96, 128, 160, 192, 224, 255];
-        let ae = [
-            [0, 0, 70],
-            [0, 0, 88],
-            [0, 52, 104],
-            [61, 108, 132],
-            [102, 150, 158],
-            [138, 187, 181],
-            [171, 220, 203],
-            [203, 250, 223],
-            [233, 255, 243],
-            [255, 255, 255],
-        ];
-        let mut img = Image::new(10, 1);
-        for (x, v) in steps.iter().enumerate() {
-            let v = *v as f32 / 255.0;
-            img.set(x as u32, 0, [v, v, v, 1.0]);
-        }
-        let vals = [
-            ("rgb/rgbInBlack", Value::Scalar(0.1)),
-            ("rgb/rgbInWhite", Value::Scalar(0.9)),
-            ("rgb/rgbGamma", Value::Scalar(1.5)),
-            ("rgb/rgbOutBlack", Value::Scalar(0.05)),
-            ("rgb/rgbOutWhite", Value::Scalar(0.95)),
-            ("red/redGamma", Value::Scalar(0.8)),
-            ("green/greenInWhite", Value::Scalar(0.8)),
-            ("blue/blueOutBlack", Value::Scalar(0.2)),
-        ];
-        let s = find("ec.color.levelsic").unwrap();
-        let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-        for (k, v) in &vals {
-            params.values.insert(k.to_string(), v.clone());
-        }
-        let render = |float_depth: bool| {
-            let env = crate::EffectEnv { float_depth, ..Default::default() };
-            let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [10.0, 1.0], seed: 1, adjustment: false, env };
-            (s.render)(&ctx, Buf { img: img.clone(), offset: [0.0, 0.0], scale: 1.0 }).img
-        };
-        let out = render(true);
-        for (x, want) in ae.iter().enumerate() {
-            let p = out.get(x as i64, 0);
-            for c in 0..3 {
-                let got = p[c].clamp(0.0, 1.0) * 255.0;
-                assert!((got - want[c] as f32).abs() <= 2.0, "step {} channel {c}: {got} vs AE {}", steps[x], want[c]);
-            }
-        }
-        // In 8 / 16 bpc "Off for 32 bpc Color" clips: black stops at Output Black.
-        let clipped = render(false);
-        assert!((clipped.get(0, 0)[0] - 0.05).abs() < 1e-5, "{:?}", clipped.get(0, 0));
-    }
-
-    /// After Effects 2026 (cases 962 / 963): Curves through RGB (0,0) (125,199)
-    /// (255,255) and Red (0,0) (128,44) (255,255) on grey steps 0..255, 8-bit results.
-    #[test]
-    fn curves_follow_a_natural_spline_as_in_after_effects() {
-        let steps = [0u8, 16, 32, 64, 96, 128, 160, 192, 224, 255];
-        let mut img = Image::new(10, 1);
-        for (x, v) in steps.iter().enumerate() {
-            let v = *v as f32 / 255.0;
-            img.set(x as u32, 0, [v, v, v, 1.0]);
-        }
-        let p = |pts: &[(f32, f32)]| Value::Str(pts.iter().map(|(x, y)| format!("{},{}", x / 255.0, y / 255.0)).collect::<Vec<_>>().join(" "));
-        let rgb = run("ec.color.curves", &img, &[("rgb", p(&[(0.0, 0.0), (125.0, 199.0), (255.0, 255.0)]))]);
-        let red = run("ec.color.curves", &img, &[("red", p(&[(0.0, 0.0), (128.0, 44.0), (255.0, 255.0)]))]);
-        let ae_rgb = [0, 30, 59, 115, 164, 202, 227, 242, 250, 255];
-        let ae_red = [0, 0, 1, 6, 19, 44, 83, 135, 194, 255];
-        for x in 0..10 {
-            let g = (rgb.get(x as i64, 0)[1] * 255.0).round() as i32;
-            let r = (red.get(x as i64, 0)[0] * 255.0).round() as i32;
-            assert!((g - ae_rgb[x]).abs() <= 1, "RGB step {}: {g} vs AE {}", steps[x], ae_rgb[x]);
-            assert!((r - ae_red[x]).abs() <= 1, "Red step {}: {r} vs AE {}", steps[x], ae_red[x]);
-        }
-    }
-
-    #[test]
-    fn levels_ic_identity_and_red_only() {
-        let img = ramp();
-        assert_eq!(run("ec.color.levelsic", &img, &[]), img);
-        let out = run("ec.color.levelsic", &img, &[("red/redOutWhite", num(0.5))]);
-        let p = out.get(15, 3);
-        assert!((p[0] - 0.5).abs() < 1e-4 && (p[1] - 0.0).abs() < 1e-4);
-    }
-
-    #[test]
-    fn auto_levels_stretches_low_contrast() {
-        let mut img = Image::new(32, 4);
-        for y in 0..4 {
-            for x in 0..32 {
-                let v = 0.4 + 0.2 * x as f32 / 31.0;
-                img.set(x, y, [v, v, v, 1.0]);
-            }
-        }
-        let out = run("ec.color.autolevels", &img, &[("blackClip", num(0.0)), ("whiteClip", num(0.0))]);
-        let lo = out.data.iter().map(|p| p[0]).fold(1.0, f32::min);
-        let hi = out.data.iter().map(|p| p[0]).fold(0.0, f32::max);
-        assert!(lo < 0.02 && hi > 0.98, "{lo} {hi}");
-        let ac = run("ec.color.autocontrast", &img, &[("blackClip", num(0.0)), ("whiteClip", num(0.0))]);
-        assert!(ac.data.iter().map(|p| p[0]).fold(0.0, f32::max) > 0.98);
-    }
-
-    #[test]
-    fn auto_color_neutralises_cast() {
-        let mut img = Image::new(16, 4);
-        for y in 0..4 {
-            for x in 0..16 {
-                let v = x as f32 / 15.0;
-                img.set(x, y, [v * 0.6 + 0.1, v * 0.9, v * 0.5, 1.0]);
-            }
-        }
-        let out = run("ec.color.autocolor", &img, &[]);
-        let p = out.get(8, 1);
-        assert!((p[0] - p[1]).abs() < 0.08 && (p[1] - p[2]).abs() < 0.08, "{p:?}");
-    }
-
-    #[test]
-    fn equalize_flattens_histogram() {
-        let mut img = Image::new(64, 1);
-        for x in 0..64 {
-            let v = if x < 48 { 0.1 + x as f32 * 0.001 } else { 0.9 };
-            img.set(x, 0, [v, v, v, 1.0]);
-        }
-        let out = run("ec.color.equalize", &img, &[]);
-        // The crowded dark values are spread across the range.
-        assert!(out.get(47, 0)[0] > 0.6, "{}", out.get(47, 0)[0]);
-        assert!(out.get(0, 0)[0] < 0.1);
-        assert_eq!(run("ec.color.equalize", &img, &[("amount", num(0.0))]), img);
-    }
-
-    #[test]
-    fn selective_color_zero_is_identity_and_reds_respond() {
-        let img = ramp();
-        assert_eq!(run("ec.color.selectivecolor", &img, &[]), img);
-        let red = Image::filled(2, 2, [1.0, 0.1, 0.1, 1.0]);
-        let out = run("ec.color.selectivecolor", &red, &[("details/reds/redsCyan", num(100.0)), ("method", Value::Enum(1))]);
-        assert!(out.data[0][0] < 0.3, "{:?}", out.data[0]);
-        let blue = Image::filled(2, 2, [0.1, 0.1, 1.0, 1.0]);
-        assert_eq!(run("ec.color.selectivecolor", &blue, &[("details/reds/redsCyan", num(100.0))]), blue);
-    }
-
-    #[test]
-    fn color_offset_full_turn_is_identity() {
-        let img = ramp();
-        let out = run("ec.color.cccoloroffset", &img, &[("redPhase", num(360.0)), ("greenPhase", num(720.0))]);
-        assert_eq!(out, img);
-        let out = run("ec.color.cccoloroffset", &img, &[("redPhase", num(180.0))]);
-        assert!((out.get(0, 3)[0] - 0.5).abs() < 1e-4);
-    }
-
-    #[test]
-    fn broadcast_reduces_unsafe_color() {
-        let img = Image::filled(2, 2, [1.0, 1.0, 0.0, 1.0]);
-        let out = run("ec.color.broadcast", &img, &[]);
-        assert!(out.data[0][0] < 1.0);
-        let key = run("ec.color.broadcast", &img, &[("howToMakeSafe", Value::Enum(2))]);
-        assert_eq!(key.data[0][3], 0.0);
-        let gray = Image::filled(2, 2, [0.5, 0.5, 0.5, 1.0]);
-        assert_eq!(run("ec.color.broadcast", &gray, &[]), gray);
-    }
-
-    #[test]
-    fn color_balance_hls_zero_identity_and_hue_shift() {
-        let img = ramp();
-        assert_eq!(run("ec.color.colorbalancehls", &img, &[]), img);
-        let red = Image::filled(1, 1, [1.0, 0.0, 0.0, 1.0]);
-        let out = run("ec.color.colorbalancehls", &red, &[("hue", num(120.0))]);
-        assert!(out.data[0][1] > 0.99 && out.data[0][0] < 0.01);
-    }
-
-    #[test]
-    fn color_link_fills_with_average_keeping_alpha() {
-        let mut img = Image::new(2, 1);
-        img.set(0, 0, [1.0, 0.0, 0.0, 1.0]);
-        img.set(1, 0, [0.0, 0.0, 0.5, 0.5]);
-        let out = run("ec.color.colorlink", &img, &[]);
-        assert!((out.data[1][3] - 0.5).abs() < 1e-5);
-        let (c, _) = unpremul(out.data[0]);
-        assert!((c[0] - 2.0 / 3.0).abs() < 1e-3 && (c[2] - 1.0 / 3.0).abs() < 1e-3, "{c:?}");
-    }
-
-    #[test]
-    fn cc_kernel_identity_and_toner_duotone() {
-        let img = ramp();
-        assert_eq!(run("ec.color.cckernel", &img, &[]), img);
-        let g = Image::filled(1, 1, [0.5, 0.5, 0.5, 1.0]);
-        let t = run("ec.color.cctoner", &g, &[("tones", Value::Enum(0)), ("highlights", col(1.0, 0.0, 0.0))]);
-        assert!((t.data[0][0] - 0.5).abs() < 1e-3 && t.data[0][1] < 1e-3);
-    }
-
-    #[test]
-    fn shadow_highlight_lifts_shadows() {
-        let img = Image::filled(8, 8, [0.1, 0.1, 0.1, 1.0]);
-        let out = run("ec.color.shadowhighlight", &img, &[("autoAmounts", Value::Bool(false))]);
-        assert!(out.data[0][0] > 0.15);
-    }
-
-    #[test]
-    fn levels_ic_clip_popups() {
-        let img = Image::filled(2, 2, [0.9, 0.9, 0.9, 1.0]);
-        let lv = [("rgb/rgbInWhite", num(0.5))];
-        assert!((run("ec.color.levelsic", &img, &lv).data[0][0] - 1.0).abs() < 1e-6);
-        let off = [("rgb/rgbInWhite", num(0.5)), ("clipToOutputWhite", Value::Enum(0))];
-        assert!(run("ec.color.levelsic", &img, &off).data[0][0] > 1.5);
-    }
-
-    /// A host whose other layers and other frames are a fixed image.
-    struct ImgHost(Image);
-    impl crate::EffectHost for ImgHost {
-        fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
-            Some(crate::LayerPixels { buf: Buf { img: self.0.clone(), offset: [0.0; 2], scale: 1.0 }, size: [2.0, 2.0] })
-        }
-        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
-            None
-        }
-        fn self_at(&self, _: f64, _: usize) -> Option<Buf> {
-            Some(Buf { img: self.0.clone(), offset: [0.0; 2], scale: 1.0 })
-        }
-    }
-
-    fn run_host(id: &str, img: &Image, over: &[(&str, Value)], host: &ImgHost) -> Image {
-        let env = crate::EffectEnv { host: Some(host), frame_rate: 10.0, ..Default::default() };
-        crate::run_fx(id, over, img.clone(), 1.0, env).img
-    }
-
-    #[test]
-    fn color_link_samples_clip_and_source_layer() {
-        let mut img = Image::new(5, 1);
-        for (x, v) in [0.0f32, 0.1, 0.2, 0.3, 1.0].iter().enumerate() {
-            img.set(x as u32, 0, [*v, *v, *v, 1.0]);
-        }
-        // Median ignores the outlier the average follows.
-        let med = run("ec.color.colorlink", &img, &[("sampleSource", Value::Enum(1))]);
-        assert!((med.data[0][0] - 0.2).abs() < 1e-5);
-        // Brightest with 20 % clip skips the brightest pixel.
-        let br = run("ec.color.colorlink", &img, &[("sampleSource", Value::Enum(2)), ("clip", num(20.0))]);
-        assert!((br.data[0][0] - 0.3).abs() < 1e-5);
-        // Min Alpha of a half-transparent source layer sets the alpha.
-        let host = ImgHost(Image::filled(2, 2, [0.25, 0.25, 0.25, 0.5]));
-        let out = run_host("ec.color.colorlink", &img, &[("sourceLayer", Value::Layer(Some(9))), ("sampleSource", Value::Enum(9))], &host);
-        assert!((out.data[4][3] - 0.5).abs() < 1e-5);
-        // Average of the source layer (not the effect's own pixels).
-        let out = run_host("ec.color.colorlink", &img, &[("sourceLayer", Value::Layer(Some(9)))], &host);
-        assert!((out.data[4][0] - 0.5).abs() < 1e-5);
-    }
-
-    #[test]
-    fn auto_levels_temporal_smoothing_reads_neighbour_frames() {
-        let mut img = Image::new(4, 1);
-        for x in 0..4 {
-            let v = 0.3 + 0.1 * x as f32;
-            img.set(x, 0, [v, v, v, 1.0]);
-        }
-        let wide = ImgHost(ramp());
-        let p0 = [("blackClip", num(0.0)), ("whiteClip", num(0.0))];
-        let alone = run_host("ec.color.autolevels", &img, &p0, &wide);
-        let smooth = run_host("ec.color.autolevels", &img, &[p0[0].clone(), p0[1].clone(), ("temporalSmoothing", num(0.2))], &wide);
-        // Alone the frame is stretched to full range; with full-range neighbours much less.
-        assert!(alone.data[0][0] < 0.01);
-        assert!(smooth.data[0][0] > 0.1, "{:?}", smooth.data[0]);
-    }
-
-    #[test]
-    fn shadow_highlight_clip_keeps_the_tonal_range() {
-        let img = ramp();
-        let lift = [("autoAmounts", Value::Bool(false)), ("shadowAmount", num(80.0))];
-        let unclipped = run(
-            "ec.color.shadowhighlight",
-            &img,
-            &[lift[0].clone(), lift[1].clone(), ("moreOptions/blackClip", num(0.0)), ("moreOptions/whiteClip", num(0.0))],
-        );
-        let clipped = run("ec.color.shadowhighlight", &img, &[lift[0].clone(), lift[1].clone(), ("moreOptions/blackClip", num(1.0))]);
-        let min = |im: &Image| im.data.iter().filter(|p| p[3] > 0.99).map(|p| luminance(p[0], p[1], p[2])).fold(f32::MAX, f32::min);
-        assert!(min(&clipped) < min(&unclipped));
-    }
-}
+mod tests;
diff --git a/crates/effects/src/color2/tests.rs b/crates/effects/src/color2/tests.rs
new file mode 100644
index 000000000..5f57692a0
--- /dev/null
+++ b/crates/effects/src/color2/tests.rs
@@ -0,0 +1,338 @@
+use super::*;
+use crate::{Params, find};
+
+fn run(id: &str, img: &Image, over: &[(&str, Value)]) -> Image {
+    let s = find(id).unwrap();
+    let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+    for (k, v) in over {
+        params.values.insert(k.to_string(), v.clone());
+    }
+    let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [img.width as f64, img.height as f64], seed: 1, adjustment: false, env: Default::default() };
+    (s.render)(&ctx, Buf { img: img.clone(), offset: [0.0, 0.0], scale: 1.0 }).img
+}
+
+fn ramp() -> Image {
+    let mut img = Image::new(16, 8);
+    for y in 0..8 {
+        for x in 0..16 {
+            let v = x as f32 / 15.0;
+            let a = if y == 0 { 0.5 } else { 1.0 };
+            img.set(x, y, [v * a, (1.0 - v) * a, 0.3 * a, a]);
+        }
+    }
+    img
+}
+
+fn close(a: &Image, b: &Image, eps: f32) -> bool {
+    a.data.iter().zip(&b.data).all(|(p, q)| (0..4).all(|i| (p[i] - q[i]).abs() <= eps))
+}
+
+#[test]
+fn curve_parsing() {
+    assert!(Curve::parse("0,0 1,1").is_none());
+    assert!(Curve::parse("garbage").is_none());
+    let c = Curve::parse("1,1; 0,0 0.5,0.7").unwrap();
+    assert_eq!(c.xs, vec![0.0, 0.5, 1.0]);
+    assert!((c.eval(0.5) - 0.7).abs() < 1e-3);
+    // Monotone: never decreases.
+    let mut last = -1.0;
+    for i in 0..=100 {
+        let v = c.eval(i as f32 / 100.0);
+        assert!(v >= last - 1e-6);
+        last = v;
+    }
+}
+
+#[test]
+fn curves_identity_is_identity() {
+    let img = ramp();
+    assert_eq!(run("ec.color.curves", &img, &[]), img);
+    let explicit = run("ec.color.curves", &img, &[("rgb", Value::Str("0,0 0.25,0.25 1,1".into()))]);
+    assert!(close(&explicit, &img, 1e-4));
+}
+
+#[test]
+fn curves_midpoint_brightens() {
+    let img = Image::filled(4, 4, [0.5, 0.5, 0.5, 1.0]);
+    let out = run("ec.color.curves", &img, &[("rgb", Value::Str("0,0 0.5,0.75 1,1".into()))]);
+    assert!((out.data[0][0] - 0.75).abs() < 1e-3);
+    let red = run("ec.color.curves", &img, &[("red", Value::Str("0,1 1,1".into()))]);
+    assert!((red.data[0][0] - 1.0).abs() < 1e-4 && (red.data[0][1] - 0.5).abs() < 1e-6);
+}
+
+/// After Effects 2026, 32 bpc project, Levels (Individual Controls) with RGB Input Black 0.1,
+/// Input White 0.9, Gamma 1.5, Output Black 0.05, Output White 0.95, Red Gamma 0.8, Green
+/// Input White 0.8, Blue Output Black 0.2, both clips "Off for 32 bpc Color", on grey steps:
+/// the channel controls run first, nothing clips (8-bit captures clamp the results).
+#[test]
+fn levels_ic_matches_after_effects_in_32_bpc() {
+    let steps = [0, 16, 32, 64, 96, 128, 160, 192, 224, 255];
+    let ae = [
+        [0, 0, 70],
+        [0, 0, 88],
+        [0, 52, 104],
+        [61, 108, 132],
+        [102, 150, 158],
+        [138, 187, 181],
+        [171, 220, 203],
+        [203, 250, 223],
+        [233, 255, 243],
+        [255, 255, 255],
+    ];
+    let mut img = Image::new(10, 1);
+    for (x, v) in steps.iter().enumerate() {
+        let v = *v as f32 / 255.0;
+        img.set(x as u32, 0, [v, v, v, 1.0]);
+    }
+    let vals = [
+        ("rgb/rgbInBlack", Value::Scalar(0.1)),
+        ("rgb/rgbInWhite", Value::Scalar(0.9)),
+        ("rgb/rgbGamma", Value::Scalar(1.5)),
+        ("rgb/rgbOutBlack", Value::Scalar(0.05)),
+        ("rgb/rgbOutWhite", Value::Scalar(0.95)),
+        ("red/redGamma", Value::Scalar(0.8)),
+        ("green/greenInWhite", Value::Scalar(0.8)),
+        ("blue/blueOutBlack", Value::Scalar(0.2)),
+    ];
+    let s = find("ec.color.levelsic").unwrap();
+    let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+    for (k, v) in &vals {
+        params.values.insert(k.to_string(), v.clone());
+    }
+    let render = |float_depth: bool| {
+        let env = crate::EffectEnv { float_depth, ..Default::default() };
+        let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [10.0, 1.0], seed: 1, adjustment: false, env };
+        (s.render)(&ctx, Buf { img: img.clone(), offset: [0.0, 0.0], scale: 1.0 }).img
+    };
+    let out = render(true);
+    for (x, want) in ae.iter().enumerate() {
+        let p = out.get(x as i64, 0);
+        for c in 0..3 {
+            let got = p[c].clamp(0.0, 1.0) * 255.0;
+            assert!((got - want[c] as f32).abs() <= 2.0, "step {} channel {c}: {got} vs AE {}", steps[x], want[c]);
+        }
+    }
+    // In 8 / 16 bpc "Off for 32 bpc Color" clips: black stops at Output Black.
+    let clipped = render(false);
+    assert!((clipped.get(0, 0)[0] - 0.05).abs() < 1e-5, "{:?}", clipped.get(0, 0));
+}
+
+/// After Effects 2026 (cases 962 / 963): Curves through RGB (0,0) (125,199)
+/// (255,255) and Red (0,0) (128,44) (255,255) on grey steps 0..255, 8-bit results.
+#[test]
+fn curves_follow_a_natural_spline_as_in_after_effects() {
+    let steps = [0u8, 16, 32, 64, 96, 128, 160, 192, 224, 255];
+    let mut img = Image::new(10, 1);
+    for (x, v) in steps.iter().enumerate() {
+        let v = *v as f32 / 255.0;
+        img.set(x as u32, 0, [v, v, v, 1.0]);
+    }
+    let p = |pts: &[(f32, f32)]| Value::Str(pts.iter().map(|(x, y)| format!("{},{}", x / 255.0, y / 255.0)).collect::<Vec<_>>().join(" "));
+    let rgb = run("ec.color.curves", &img, &[("rgb", p(&[(0.0, 0.0), (125.0, 199.0), (255.0, 255.0)]))]);
+    let red = run("ec.color.curves", &img, &[("red", p(&[(0.0, 0.0), (128.0, 44.0), (255.0, 255.0)]))]);
+    let ae_rgb = [0, 30, 59, 115, 164, 202, 227, 242, 250, 255];
+    let ae_red = [0, 0, 1, 6, 19, 44, 83, 135, 194, 255];
+    for x in 0..10 {
+        let g = (rgb.get(x as i64, 0)[1] * 255.0).round() as i32;
+        let r = (red.get(x as i64, 0)[0] * 255.0).round() as i32;
+        assert!((g - ae_rgb[x]).abs() <= 1, "RGB step {}: {g} vs AE {}", steps[x], ae_rgb[x]);
+        assert!((r - ae_red[x]).abs() <= 1, "Red step {}: {r} vs AE {}", steps[x], ae_red[x]);
+    }
+}
+
+#[test]
+fn levels_ic_identity_and_red_only() {
+    let img = ramp();
+    assert_eq!(run("ec.color.levelsic", &img, &[]), img);
+    let out = run("ec.color.levelsic", &img, &[("red/redOutWhite", num(0.5))]);
+    let p = out.get(15, 3);
+    assert!((p[0] - 0.5).abs() < 1e-4 && (p[1] - 0.0).abs() < 1e-4);
+}
+
+#[test]
+fn auto_levels_stretches_low_contrast() {
+    let mut img = Image::new(32, 4);
+    for y in 0..4 {
+        for x in 0..32 {
+            let v = 0.4 + 0.2 * x as f32 / 31.0;
+            img.set(x, y, [v, v, v, 1.0]);
+        }
+    }
+    let out = run("ec.color.autolevels", &img, &[("blackClip", num(0.0)), ("whiteClip", num(0.0))]);
+    let lo = out.data.iter().map(|p| p[0]).fold(1.0, f32::min);
+    let hi = out.data.iter().map(|p| p[0]).fold(0.0, f32::max);
+    assert!(lo < 0.02 && hi > 0.98, "{lo} {hi}");
+    let ac = run("ec.color.autocontrast", &img, &[("blackClip", num(0.0)), ("whiteClip", num(0.0))]);
+    assert!(ac.data.iter().map(|p| p[0]).fold(0.0, f32::max) > 0.98);
+}
+
+#[test]
+fn auto_color_neutralises_cast() {
+    let mut img = Image::new(16, 4);
+    for y in 0..4 {
+        for x in 0..16 {
+            let v = x as f32 / 15.0;
+            img.set(x, y, [v * 0.6 + 0.1, v * 0.9, v * 0.5, 1.0]);
+        }
+    }
+    let out = run("ec.color.autocolor", &img, &[]);
+    let p = out.get(8, 1);
+    assert!((p[0] - p[1]).abs() < 0.08 && (p[1] - p[2]).abs() < 0.08, "{p:?}");
+}
+
+#[test]
+fn equalize_flattens_histogram() {
+    let mut img = Image::new(64, 1);
+    for x in 0..64 {
+        let v = if x < 48 { 0.1 + x as f32 * 0.001 } else { 0.9 };
+        img.set(x, 0, [v, v, v, 1.0]);
+    }
+    let out = run("ec.color.equalize", &img, &[]);
+    // The crowded dark values are spread across the range.
+    assert!(out.get(47, 0)[0] > 0.6, "{}", out.get(47, 0)[0]);
+    assert!(out.get(0, 0)[0] < 0.1);
+    assert_eq!(run("ec.color.equalize", &img, &[("amount", num(0.0))]), img);
+}
+
+#[test]
+fn selective_color_zero_is_identity_and_reds_respond() {
+    let img = ramp();
+    assert_eq!(run("ec.color.selectivecolor", &img, &[]), img);
+    let red = Image::filled(2, 2, [1.0, 0.1, 0.1, 1.0]);
+    let out = run("ec.color.selectivecolor", &red, &[("details/reds/redsCyan", num(100.0)), ("method", Value::Enum(1))]);
+    assert!(out.data[0][0] < 0.3, "{:?}", out.data[0]);
+    let blue = Image::filled(2, 2, [0.1, 0.1, 1.0, 1.0]);
+    assert_eq!(run("ec.color.selectivecolor", &blue, &[("details/reds/redsCyan", num(100.0))]), blue);
+}
+
+#[test]
+fn color_offset_full_turn_is_identity() {
+    let img = ramp();
+    let out = run("ec.color.cccoloroffset", &img, &[("redPhase", num(360.0)), ("greenPhase", num(720.0))]);
+    assert_eq!(out, img);
+    let out = run("ec.color.cccoloroffset", &img, &[("redPhase", num(180.0))]);
+    assert!((out.get(0, 3)[0] - 0.5).abs() < 1e-4);
+}
+
+#[test]
+fn broadcast_reduces_unsafe_color() {
+    let img = Image::filled(2, 2, [1.0, 1.0, 0.0, 1.0]);
+    let out = run("ec.color.broadcast", &img, &[]);
+    assert!(out.data[0][0] < 1.0);
+    let key = run("ec.color.broadcast", &img, &[("howToMakeSafe", Value::Enum(2))]);
+    assert_eq!(key.data[0][3], 0.0);
+    let gray = Image::filled(2, 2, [0.5, 0.5, 0.5, 1.0]);
+    assert_eq!(run("ec.color.broadcast", &gray, &[]), gray);
+}
+
+#[test]
+fn color_balance_hls_zero_identity_and_hue_shift() {
+    let img = ramp();
+    assert_eq!(run("ec.color.colorbalancehls", &img, &[]), img);
+    let red = Image::filled(1, 1, [1.0, 0.0, 0.0, 1.0]);
+    let out = run("ec.color.colorbalancehls", &red, &[("hue", num(120.0))]);
+    assert!(out.data[0][1] > 0.99 && out.data[0][0] < 0.01);
+}
+
+#[test]
+fn color_link_fills_with_average_keeping_alpha() {
+    let mut img = Image::new(2, 1);
+    img.set(0, 0, [1.0, 0.0, 0.0, 1.0]);
+    img.set(1, 0, [0.0, 0.0, 0.5, 0.5]);
+    let out = run("ec.color.colorlink", &img, &[]);
+    assert!((out.data[1][3] - 0.5).abs() < 1e-5);
+    let (c, _) = unpremul(out.data[0]);
+    assert!((c[0] - 2.0 / 3.0).abs() < 1e-3 && (c[2] - 1.0 / 3.0).abs() < 1e-3, "{c:?}");
+}
+
+#[test]
+fn cc_kernel_identity_and_toner_duotone() {
+    let img = ramp();
+    assert_eq!(run("ec.color.cckernel", &img, &[]), img);
+    let g = Image::filled(1, 1, [0.5, 0.5, 0.5, 1.0]);
+    let t = run("ec.color.cctoner", &g, &[("tones", Value::Enum(0)), ("highlights", col(1.0, 0.0, 0.0))]);
+    assert!((t.data[0][0] - 0.5).abs() < 1e-3 && t.data[0][1] < 1e-3);
+}
+
+#[test]
+fn shadow_highlight_lifts_shadows() {
+    let img = Image::filled(8, 8, [0.1, 0.1, 0.1, 1.0]);
+    let out = run("ec.color.shadowhighlight", &img, &[("autoAmounts", Value::Bool(false))]);
+    assert!(out.data[0][0] > 0.15);
+}
+
+#[test]
+fn levels_ic_clip_popups() {
+    let img = Image::filled(2, 2, [0.9, 0.9, 0.9, 1.0]);
+    let lv = [("rgb/rgbInWhite", num(0.5))];
+    assert!((run("ec.color.levelsic", &img, &lv).data[0][0] - 1.0).abs() < 1e-6);
+    let off = [("rgb/rgbInWhite", num(0.5)), ("clipToOutputWhite", Value::Enum(0))];
+    assert!(run("ec.color.levelsic", &img, &off).data[0][0] > 1.5);
+}
+
+/// A host whose other layers and other frames are a fixed image.
+struct ImgHost(Image);
+impl crate::EffectHost for ImgHost {
+    fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
+        Some(crate::LayerPixels { buf: Buf { img: self.0.clone(), offset: [0.0; 2], scale: 1.0 }, size: [2.0, 2.0] })
+    }
+    fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+        None
+    }
+    fn self_at(&self, _: f64, _: usize) -> Option<Buf> {
+        Some(Buf { img: self.0.clone(), offset: [0.0; 2], scale: 1.0 })
+    }
+}
+
+fn run_host(id: &str, img: &Image, over: &[(&str, Value)], host: &ImgHost) -> Image {
+    let env = crate::EffectEnv { host: Some(host), frame_rate: 10.0, ..Default::default() };
+    crate::run_fx(id, over, img.clone(), 1.0, env).img
+}
+
+#[test]
+fn color_link_samples_clip_and_source_layer() {
+    let mut img = Image::new(5, 1);
+    for (x, v) in [0.0f32, 0.1, 0.2, 0.3, 1.0].iter().enumerate() {
+        img.set(x as u32, 0, [*v, *v, *v, 1.0]);
+    }
+    // Median ignores the outlier the average follows.
+    let med = run("ec.color.colorlink", &img, &[("sampleSource", Value::Enum(1))]);
+    assert!((med.data[0][0] - 0.2).abs() < 1e-5);
+    // Brightest with 20 % clip skips the brightest pixel.
+    let br = run("ec.color.colorlink", &img, &[("sampleSource", Value::Enum(2)), ("clip", num(20.0))]);
+    assert!((br.data[0][0] - 0.3).abs() < 1e-5);
+    // Min Alpha of a half-transparent source layer sets the alpha.
+    let host = ImgHost(Image::filled(2, 2, [0.25, 0.25, 0.25, 0.5]));
+    let out = run_host("ec.color.colorlink", &img, &[("sourceLayer", Value::Layer(Some(9))), ("sampleSource", Value::Enum(9))], &host);
+    assert!((out.data[4][3] - 0.5).abs() < 1e-5);
+    // Average of the source layer (not the effect's own pixels).
+    let out = run_host("ec.color.colorlink", &img, &[("sourceLayer", Value::Layer(Some(9)))], &host);
+    assert!((out.data[4][0] - 0.5).abs() < 1e-5);
+}
+
+#[test]
+fn auto_levels_temporal_smoothing_reads_neighbour_frames() {
+    let mut img = Image::new(4, 1);
+    for x in 0..4 {
+        let v = 0.3 + 0.1 * x as f32;
+        img.set(x, 0, [v, v, v, 1.0]);
+    }
+    let wide = ImgHost(ramp());
+    let p0 = [("blackClip", num(0.0)), ("whiteClip", num(0.0))];
+    let alone = run_host("ec.color.autolevels", &img, &p0, &wide);
+    let smooth = run_host("ec.color.autolevels", &img, &[p0[0].clone(), p0[1].clone(), ("temporalSmoothing", num(0.2))], &wide);
+    // Alone the frame is stretched to full range; with full-range neighbours much less.
+    assert!(alone.data[0][0] < 0.01);
+    assert!(smooth.data[0][0] > 0.1, "{:?}", smooth.data[0]);
+}
+
+#[test]
+fn shadow_highlight_clip_keeps_the_tonal_range() {
+    let img = ramp();
+    let lift = [("autoAmounts", Value::Bool(false)), ("shadowAmount", num(80.0))];
+    let unclipped =
+        run("ec.color.shadowhighlight", &img, &[lift[0].clone(), lift[1].clone(), ("moreOptions/blackClip", num(0.0)), ("moreOptions/whiteClip", num(0.0))]);
+    let clipped = run("ec.color.shadowhighlight", &img, &[lift[0].clone(), lift[1].clone(), ("moreOptions/blackClip", num(1.0))]);
+    let min = |im: &Image| im.data.iter().filter(|p| p[3] > 0.99).map(|p| luminance(p[0], p[1], p[2])).fold(f32::MAX, f32::min);
+    assert!(min(&clipped) < min(&unclipped));
+}
diff --git a/crates/effects/src/color_fx.rs b/crates/effects/src/color_fx.rs
index 06884017c..3a52e7a54 100644
--- a/crates/effects/src/color_fx.rs
+++ b/crates/effects/src/color_fx.rs
@@ -1215,524 +1215,4 @@ pub fn specs() -> Vec<EffectSpec> {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::{EffectEnv, run_fx};
-    use effectcraft_raster::Image;
-
-    fn px(id: &str, vals: &[(&str, Value)], c: [f32; 4]) -> [f32; 4] {
-        run_fx(id, vals, Image::filled(2, 2, c), 0.0, EffectEnv::default()).img.get(0, 0)
-    }
-    fn close(a: [f32; 4], b: [f32; 4], eps: f32) -> bool {
-        a.iter().zip(b).all(|(x, y)| (x - y).abs() <= eps)
-    }
-
-    /// Projects saved before Use Legacy / the Photo Filter menu existed keep rendering as before.
-    #[test]
-    fn old_saves_get_legacy_values_for_added_params() {
-        use effectcraft_project::build::Ids;
-        let mut next = 1;
-        for (id, param, want) in
-            [("ec.color.brightnesscontrast", "useLegacy", Value::Bool(true)), ("ec.color.photofilter", "filter", Value::Enum(PHOTO_FILTER_CUSTOM))]
-        {
-            let spec = crate::find(id).unwrap();
-            let mut g = crate::instantiate(spec, &mut Ids(&mut next), spec.name, [10.0, 10.0]);
-            g.children.retain(|c| c.match_id() != param);
-            crate::migrate::upgrade_instance(spec, &mut g, &mut Ids(&mut next), [10.0, 10.0]);
-            assert_eq!(g.get(param).unwrap().value, want, "{id}");
-        }
-    }
-
-    /// After Effects 2026 renders of full-frame solids with Tint at its defaults (sRGB working
-    /// space, not linearised, 32 bpc, 8-bit capture): Rec. 601 weights on the encoded values.
-    #[test]
-    fn tint_defaults_match_after_effects_greys() {
-        for (c, want) in [([1.0, 0.0, 0.0], 76.0), ([0.0, 1.0, 0.0], 150.0), ([0.0, 0.0, 1.0], 29.0), ([0.5, 0.5, 0.5], 128.0)] {
-            let o = px("ec.color.tint", &[], [c[0], c[1], c[2], 1.0]);
-            let want = want / 255.0;
-            assert!(close(o, [want, want, want, 1.0], 1.0 / 255.0), "{c:?}: {o:?} vs {want}");
-        }
-    }
-
-    #[test]
-    fn colorama_reads_get_phase_from() {
-        // Same intensity, different red: Intensity gives one colour, Red gives two.
-        let a = [0.6, 0.2, 0.2, 1.0];
-        let b = [0.2, 0.2, 0.6, 1.0];
-        let red = |c| px("ec.color.colorama", &[("inputPhase/mode", Value::Enum(1))], c);
-        assert!(!close(red(a), red(b), 1e-3));
-        // Zero maps everything to the start of the cycle (red).
-        assert!(close(px("ec.color.colorama", &[("inputPhase/mode", Value::Enum(9))], b), [1.0, 0.0, 0.0, 1.0], 1e-5));
-        // Interpolate Palette off posterizes: two nearby inputs land on the same colour.
-        let off = |v: f32| px("ec.color.colorama", &[("outputCycle/interpolatePalette", Value::Bool(false))], [v, v, v, 1.0]);
-        assert_eq!(off(0.20), off(0.22));
-    }
-
-    #[test]
-    fn brightness_contrast_modern_keeps_black_and_white_and_legacy_is_linear() {
-        let bc = |vals: &[(&str, Value)], v: f32| px("ec.color.brightnesscontrast", vals, [v, v, v, 1.0])[0];
-        let up = [("brightness", num(50.0)), ("contrast", num(40.0))];
-        assert_eq!(bc(&up, 0.0), 0.0);
-        assert!((bc(&up, 1.0) - 1.0).abs() < 1e-6);
-        assert!(bc(&up, 0.4) > 0.4);
-        let legacy = [("brightness", num(50.0)), ("useLegacy", Value::Bool(true))];
-        assert!((bc(&legacy, 0.2) - 0.7).abs() < 1e-5);
-        assert!((bc(&legacy, 0.0) - 0.5).abs() < 1e-5);
-    }
-
-    /// After Effects non-legacy ramps (kasper9n, #681). B0 C-100 matched B0 C-50 and is omitted.
-    #[test]
-    fn brightness_contrast_modern_matches_ae_ramp_samples() {
-        let u8 = |v: f32| (v * 255.0).round() as i32;
-        let go = |b: f64, c: f64, x: u8| {
-            u8(px("ec.color.brightnesscontrast", &[("brightness", num(b)), ("contrast", num(c))], [x as f32 / 255.0, x as f32 / 255.0, x as f32 / 255.0, 1.0])
-                [0])
-        };
-        // (brightness, contrast, input, AE 8-bit)
-        let samples: &[(f64, f64, u8, u8)] = &[
-            (0.0, 100.0, 64, 40),
-            (0.0, 100.0, 128, 129),
-            (0.0, 100.0, 192, 217),
-            (0.0, 50.0, 64, 53),
-            (0.0, 50.0, 192, 205),
-            (0.0, -50.0, 64, 77),
-            (100.0, 0.0, 128, 209),
-            (50.0, 0.0, 128, 171),
-            (106.0, -18.0, 128, 214),
-        ];
-        for &(b, c, x, ae) in samples {
-            let got = go(b, c, x);
-            assert!((got - ae as i32).abs() <= 10, "B{b} C{c} in {x}: got {got} AE {ae}");
-        }
-        // Old g=4 S-curve put Contrast 100 at ~8/255 here.
-        assert!(go(0.0, 100.0, 64) >= 30);
-    }
-
-    /// After Effects 2026: Tritone Highlights [1, 1, 0.8], Midtones [0.6, 0.2, 0.2], Shadows
-    /// [0, 0, 0.3]. On a red solid with Blend With Original 25 (case 718) AE gives (132, 23, 46);
-    /// on a grey ramp (case 815) levels 0, 63.9, 127.6, 191.4 give (0, 0, 77), (77, 26, 64),
-    /// (153, 51, 51), (204, 153, 128).
-    #[test]
-    fn tritone_matches_after_effects() {
-        let colours = [
-            ("highlights", Value::Color([1.0, 1.0, 0.8, 1.0])),
-            ("midtones", Value::Color([0.6, 0.2, 0.2, 1.0])),
-            ("shadows", Value::Color([0.0, 0.0, 0.3, 1.0])),
-        ];
-        let near = |o: [f32; 4], ae: [f32; 3]| (0..3).all(|i| (o[i] * 255.0 - ae[i]).abs() <= 1.0);
-        let mut red = colours.to_vec();
-        red.push(("blend", num(25.0)));
-        let o = px("ec.color.tritone", &red, [1.0, 0.0, 0.0, 1.0]);
-        assert!(near(o, [132.0, 23.0, 46.0]), "{:?}", o.map(|v| v * 255.0));
-        for (level, ae) in [(0.1f32, [0.0, 0.0, 77.0]), (63.9, [77.0, 26.0, 64.0]), (127.6, [153.0, 51.0, 51.0]), (191.4, [204.0, 153.0, 128.0])] {
-            let v = level / 255.0;
-            let o = px("ec.color.tritone", &colours, [v, v, v, 1.0]);
-            assert!(near(o, ae), "level {level}: {:?} vs {ae:?}", o.map(|v| v * 255.0));
-        }
-    }
-
-    /// After Effects 2026, Tint Color [1, 0.5, 0]: a red solid at Reds 10 (case 717) and yellow
-    /// and white solids at the default sliders (case 825).
-    #[test]
-    fn black_white_tint_matches_after_effects() {
-        let tint = [("tint", Value::Bool(true)), ("tintColor", Value::Color([1.0, 0.5, 0.0, 1.0]))];
-        let near = |o: [f32; 4], ae: [f32; 3]| (0..3).all(|i| (o[i] * 255.0 - ae[i]).abs() <= 1.5);
-        let mut reds = tint.to_vec();
-        reds.push(("reds", num(10.0)));
-        let o = px("ec.color.blackwhite", &reds, [1.0, 0.0, 0.0, 1.0]);
-        assert!(near(o, [43.0, 21.0, 0.0]), "{:?}", o.map(|v| v * 255.0));
-        let o = px("ec.color.blackwhite", &tint, [1.0, 1.0, 0.0, 1.0]);
-        assert!(near(o, [255.0, 129.0, 2.0]), "{:?}", o.map(|v| v * 255.0));
-        let o = px("ec.color.blackwhite", &tint, [1.0, 1.0, 1.0, 1.0]);
-        assert!(near(o, [255.0, 255.0, 255.0]), "{:?}", o.map(|v| v * 255.0));
-        // Hostile grays stay finite.
-        for g in [f32::NAN, -1.0, 0.0, 4.0] {
-            assert!(bw_tint([1.0, 0.5, 0.0], g).iter().all(|v| v.is_finite()));
-        }
-    }
-
-    /// After Effects 2026 ramps (RENDERER round 2, session R8): negative Brightness and Contrast
-    /// are the inverses of the positive curves. (brightness, contrast, input, AE 8-bit)
-    #[test]
-    fn negative_brightness_and_contrast_invert_the_positive_curves() {
-        let go = |b: f64, c: f64, x: u8| {
-            let v = x as f32 / 255.0;
-            (px("ec.color.brightnesscontrast", &[("brightness", num(b)), ("contrast", num(c))], [v, v, v, 1.0])[0] * 255.0).round() as i32
-        };
-        let samples: &[(f64, f64, u8, u8)] = &[
-            (-40.0, 0.0, 64, 50),
-            (-40.0, 0.0, 128, 99),
-            (-40.0, 0.0, 191, 155),
-            (-40.0, 0.0, 234, 207),
-            (0.0, -50.0, 21, 28),
-            (0.0, -50.0, 64, 76),
-            (0.0, -50.0, 191, 179),
-            (0.0, -50.0, 234, 227),
-            (40.0, 0.0, 128, 162),
-            (0.0, 50.0, 64, 52),
-        ];
-        for &(b, c, x, ae) in samples {
-            let got = go(b, c, x);
-            assert!((got - ae as i32).abs() <= 7, "B{b} C{c} in {x}: got {got} AE {ae}");
-        }
-    }
-
-    /// #1463: Black & White's sliders set the gray of each pure hue and blend between
-    /// neighbouring hues; neutral pixels keep their value, overbright ones too, and an overbright
-    /// colour stays finite (it used to divide by zero).
-    #[test]
-    fn black_white_sliders_set_the_gray_of_each_hue() {
-        let bw = |vals: &[(&str, Value)], c: [f32; 3]| px("ec.color.blackwhite", vals, [c[0], c[1], c[2], 1.0]);
-        let gray = |v: f32| [v, v, v, 1.0];
-        // The defaults: Reds 40, Yellows 60, Greens 40, Cyans 60, Blues 20, Magentas 80 (%).
-        let hues = [
-            ([1.0, 0.0, 0.0], 0.4),
-            ([1.0, 1.0, 0.0], 0.6),
-            ([0.0, 1.0, 0.0], 0.4),
-            ([0.0, 1.0, 1.0], 0.6),
-            ([0.0, 0.0, 1.0], 0.2),
-            ([1.0, 0.0, 1.0], 0.8),
-            // Half as bright, half the gray; orange is halfway from Reds to Yellows.
-            ([0.5, 0.0, 0.0], 0.2),
-            ([1.0, 0.5, 0.0], 0.5),
-            // Neutral pixels keep their value.
-            ([0.3, 0.3, 0.3], 0.3),
-            ([4.0, 4.0, 4.0], 4.0),
-            // An overbright red: its smallest channel plus its chroma at Reds' 40 %.
-            ([1.5, 0.5, 0.5], 0.9),
-        ];
-        for (c, want) in hues {
-            let o = bw(&[], c);
-            assert!(close(o, gray(want), 1e-5), "{c:?}: {o:?}, want {want}");
-        }
-        assert!(close(bw(&[("reds", num(120.0))], [1.0, 0.0, 0.0]), gray(1.2), 1e-5));
-        assert!(close(bw(&[("reds", num(-200.0))], [1.0, 0.0, 0.0]), gray(0.0), 1e-5));
-        assert!(close(bw(&[("blues", num(300.0))], [0.1, 0.1, 0.3]), gray(0.7), 1e-5));
-    }
-
-    /// #1463: faint colour noise stays faint. The shadows of compressed footage carry a code or
-    /// two of colour noise, which Black & White turned into bright and black blocks (the HSL
-    /// saturation it scaled is near 1 for any tinted near-black pixel). At 8, 16 and 32 bpc the
-    /// gray of a dark ramp with ±2 steps of colour noise stays within 2 steps of the clean ramp's.
-    #[test]
-    fn black_white_keeps_faint_colour_noise_faint() {
-        // A step of 8 bpc, of 16 bpc (After Effects' 0..32768), and a small 32-bpc float one.
-        for step in [1.0 / 255.0, 1.0 / 32768.0, 1e-3_f32] {
-            let (w, h) = (64u32, 4u32);
-            let (mut clean, mut noisy) = (Image::new(w, h), Image::new(w, h));
-            for y in 0..h {
-                for x in 0..w {
-                    // A dark ramp up to a quarter gray, in whole steps...
-                    let v = (x as f32 / w as f32 * 0.25 / step).round() * step;
-                    // ...and up to ±2 steps of noise per channel, mixed differently in each pixel.
-                    let n = |k: u32| (((x * 7 + y * 13 + k * 2) % 5) as f32 - 2.0) * step;
-                    clean.set(x, y, [v, v, v, 1.0]);
-                    noisy.set(x, y, [(v + n(0)).max(0.0), (v + n(1)).max(0.0), (v + n(2)).max(0.0), 1.0]);
-                }
-            }
-            let bw = |img| run_fx("ec.color.blackwhite", &[], img, 0.0, EffectEnv::default()).img;
-            let (a, b) = (bw(clean), bw(noisy));
-            let worst = a.data.iter().zip(&b.data).map(|(p, q)| (p[0] - q[0]).abs()).fold(0.0, f32::max);
-            assert!(worst <= 2.0 * step + 1e-6, "step {step}: the noise moved the gray by {} steps", worst / step);
-        }
-    }
-
-    #[test]
-    fn levels_clips_black_and_white_independently() {
-        let lv = |vals: &[(&str, Value)], v: f32| px("ec.color.levels", vals, [v, v, v, 1.0])[0];
-        let base = [("inBlack", num(0.2)), ("inWhite", num(0.6)), ("outBlack", num(0.1)), ("outWhite", num(0.9))];
-        assert!((lv(&base, 0.9) - 0.9).abs() < 1e-5);
-        let mut no_white = base.to_vec();
-        no_white.push(("clipToOutputWhite", Value::Enum(0)));
-        assert!(lv(&no_white, 0.9) > 0.9);
-        assert!((lv(&no_white, 0.0) - 0.1).abs() < 1e-5);
-        // The hidden switch of older projects turns both off.
-        let mut legacy = base.to_vec();
-        legacy.push(("noClip", Value::Bool(true)));
-        assert!(lv(&legacy, 0.9) > 0.9);
-    }
-
-    #[test]
-    fn exposure_individual_channels_and_bypass() {
-        let g = [0.5, 0.5, 0.5, 1.0];
-        let one = px("ec.color.exposure", &[("channels", Value::Enum(1)), ("red/redExposure", num(1.0))], g);
-        assert!(one[0] > 0.6 && (one[1] - 0.5).abs() < 1e-5 && (one[2] - 0.5).abs() < 1e-5);
-        // Master values are ignored in Individual Channels mode.
-        assert!(close(px("ec.color.exposure", &[("channels", Value::Enum(1)), ("master/exposure", num(2.0))], g), g, 1e-5));
-        // Bypass Linear Light Conversion: +1 stop doubles the raw value.
-        let raw = px("ec.color.exposure", &[("master/exposure", num(1.0)), ("bypassLinearLight", Value::Bool(true))], [0.25, 0.25, 0.25, 1.0]);
-        assert!((raw[0] - 0.5).abs() < 1e-5);
-        // Negative results are mirrored, not clipped.
-        let neg = px(
-            "ec.color.exposure",
-            &[("master/offset", num(-0.5)), ("bypassLinearLight", Value::Bool(true)), ("master/gamma", num(2.0))],
-            [0.25, 0.25, 0.25, 1.0],
-        );
-        assert!((neg[0] + 0.5).abs() < 1e-4, "{neg:?}");
-    }
-
-    /// After Effects' Exposure ranges for all twelve sliders; a saved value outside them (a gamma
-    /// of 0.05, valid before, as in Photoshop) survives loading and still renders.
-    #[test]
-    fn exposure_has_after_effects_ranges_and_keeps_old_values() {
-        use effectcraft_project::build::Ids;
-        let spec = crate::find("ec.color.exposure").unwrap();
-        let want = [(-100.0, 100.0, -4.0, 4.0, 2), (-2.0, 2.0, -0.5, 0.5, 4), (0.1, 10.0, 0.1, 10.0, 2)];
-        let sliders: Vec<_> = spec
-            .params
-            .iter()
-            .filter_map(|p| match p.ui {
-                ParamUi::Slider { min, max, slider_min, slider_max, decimals } => Some((p.id, (min, max, slider_min, slider_max, decimals))),
-                _ => None,
-            })
-            .collect();
-        assert_eq!(sliders.len(), 12);
-        for (i, (id, r)) in sliders.iter().enumerate() {
-            assert_eq!(*r, want[i % 3], "{id}");
-        }
-        let mut next = 1;
-        let mut g = crate::instantiate(spec, &mut Ids(&mut next), spec.name, [10.0, 10.0]);
-        let gamma = g.prop_mut("master/gamma").unwrap();
-        gamma.value = num(0.05);
-        gamma.ui = slider(0.01, 9.99, 0.1, 3.0, 2);
-        crate::migrate::upgrade_instance(spec, &mut g, &mut Ids(&mut next), [10.0, 10.0]);
-        let gamma = g.prop_mut("master/gamma").unwrap();
-        assert_eq!(gamma.value, num(0.05));
-        assert!(matches!(gamma.ui, ParamUi::Slider { min, .. } if min == 0.1));
-        let o = px("ec.color.exposure", &[("master/gamma", num(0.05)), ("bypassLinearLight", Value::Bool(true))], [0.5, 0.5, 0.5, 1.0]);
-        assert!((o[0] - 0.5f32.powf(20.0)).abs() < 1e-9, "{o:?}");
-    }
-
-    /// Exposure on a red [1, 0, 0] solid against After Effects 2026 renders (sRGB working space,
-    /// not linearised, 32 bpc, 8-bit captures): the linear-light conversion is a pure 2.2 power.
-    /// The piecewise sRGB curve gave 2 / 7 / 39 for the three smallest Offsets.
-    #[test]
-    fn exposure_matches_after_effects_gamma_2_2() {
-        let red = [1.0, 0.0, 0.0, 1.0];
-        let code = |o: [f32; 4], i: usize| o[i] * 255.0;
-        // Master Offset only: G and B carry the curve; R goes over 1 (255 in the 8-bit capture).
-        for (offset, ae) in [(0.0005, 8.0), (0.002, 15.0), (0.02, 43.0), (0.1, 90.0)] {
-            let o = px("ec.color.exposure", &[("master/offset", num(offset))], red);
-            for i in [1, 2] {
-                assert!((code(o, i) - ae).abs() <= 1.0, "offset {offset}: {} vs AE {ae}", code(o, i));
-            }
-            assert!(o[0] >= 1.0, "{o:?}");
-        }
-        // Exposure −2.25: AE 126; with Bypass Linear Light Conversion (gain on encoded values) 54.
-        let o = px("ec.color.exposure", &[("master/exposure", num(-2.25))], red);
-        assert!((code(o, 0) - 126.0).abs() <= 1.0 && o[1] == 0.0, "{o:?}");
-        let o = px("ec.color.exposure", &[("master/exposure", num(-2.25)), ("bypassLinearLight", Value::Bool(true))], red);
-        assert!((code(o, 0) - 54.0).abs() <= 1.0 && o[1] == 0.0, "{o:?}");
-        // Default settings leave 32-bpc values alone, negative and over-range ones included.
-        let hdr = [-0.25, 0.5, 2.0, 1.0];
-        assert!(close(px("ec.color.exposure", &[], hdr), hdr, 1e-5));
-        // A negative Offset pushes black below zero, mirrored, rather than clipping or NaN.
-        let o = px("ec.color.exposure", &[("master/offset", num(-0.02))], [0.0, 0.0, 0.0, 1.0]);
-        assert!((o[0] + 0.02f32.powf(1.0 / 2.2)).abs() < 1e-5, "{o:?}");
-    }
-
-    #[test]
-    fn change_to_color_change_modes_tolerances_and_matte() {
-        let red = [0.8, 0.1, 0.1, 1.0];
-        let green = [0.1, 0.8, 0.1, 1.0];
-        let base = [("from", col(0.8, 0.1, 0.1)), ("to", col(0.1, 0.1, 0.8))];
-        // Hue only: red turns blue with its own lightness / saturation; green is untouched.
-        let o = px("ec.color.changetocolor", &base, red);
-        assert!(o[2] > 0.7 && o[0] < 0.2, "{o:?}");
-        assert!(close(px("ec.color.changetocolor", &base, green), green, 1e-5));
-        // The matte is white where matched, black elsewhere.
-        let mut m = base.to_vec();
-        m.push(("viewCorrectionMatte", Value::Bool(true)));
-        assert!(close(px("ec.color.changetocolor", &m, red), [1.0, 1.0, 1.0, 1.0], 1e-5));
-        assert!(close(px("ec.color.changetocolor", &m, green), [0.0, 0.0, 0.0, 1.0], 1e-5));
-        // A lightness tolerance of 0 rejects a lighter red.
-        let mut strict = m.clone();
-        strict.push(("toleranceGroup/lightness", num(0.0)));
-        strict.push(("softness", num(0.0)));
-        assert!(close(px("ec.color.changetocolor", &strict, [1.0, 0.5, 0.5, 1.0]), [0.0, 0.0, 0.0, 1.0], 1e-5));
-        // Hue, Lightness & Saturation, set: a matched pixel becomes the To colour.
-        let mut all = base.to_vec();
-        all.push(("change", Value::Enum(3)));
-        assert!(close(px("ec.color.changetocolor", &all, red), [0.1, 0.1, 0.8, 1.0], 1e-4));
-    }
-
-    #[test]
-    fn leave_color_tolerance_softness_and_match_mode() {
-        let green = [0.1, 0.8, 0.1, 1.0];
-        let lc = |vals: &[(&str, Value)]| {
-            let mut v = vec![("amount", num(100.0))];
-            v.extend_from_slice(vals);
-            px("ec.color.leavecolor", &v, green)
-        };
-        let g = luminance(0.1, 0.8, 0.1);
-        assert!(close(lc(&[]), [g, g, g, 1.0], 1e-5));
-        assert!(close(lc(&[("tolerance", num(100.0))]), green, 1e-6));
-        // Softness keeps part of the colour.
-        let s = lc(&[("tolerance", num(10.0)), ("edgeSoftness", num(100.0))]);
-        assert!(s[1] > g + 0.05 && s[1] < 0.8);
-        // Using Hue: a dark red still matches pure red.
-        let dark = px("ec.color.leavecolor", &[("amount", num(100.0)), ("tolerance", num(5.0)), ("matchColors", Value::Enum(1))], [0.4, 0.0, 0.0, 1.0]);
-        assert!(close(dark, [0.4, 0.0, 0.0, 1.0], 1e-6));
-    }
-
-    #[test]
-    fn photo_filter_presets_and_custom() {
-        let g = [0.5, 0.5, 0.5, 1.0];
-        let cool = px("ec.color.photofilter", &[("filter", Value::Enum(3)), ("preserveLuminosity", Value::Bool(false))], g);
-        assert!(cool[2] > cool[0], "a cooling filter is blue: {cool:?}");
-        let custom = |c| px("ec.color.photofilter", &[("filter", Value::Enum(PHOTO_FILTER_CUSTOM)), ("color", c)], g);
-        assert!(custom(col(0.0, 1.0, 0.0))[1] > custom(col(1.0, 0.0, 0.0))[1]);
-        // The Color swatch is ignored by the presets.
-        let warm = |c| px("ec.color.photofilter", &[("color", c)], g);
-        assert_eq!(warm(col(0.0, 1.0, 0.0)), warm(col(1.0, 0.0, 0.0)));
-    }
-
-    #[test]
-    fn color_balance_preserve_luminosity_and_black_stretch() {
-        let g = [0.5, 0.5, 0.5, 1.0];
-        let o = px("ec.color.colorbalance", &[("midRed", num(60.0)), ("preserveLuminosity", Value::Bool(true))], g);
-        assert!((luminance(o[0], o[1], o[2]) - 0.5).abs() < 1e-4 && o[0] > o[2]);
-        let dark = [0.1, 0.1, 0.1, 1.0];
-        assert!(px("ec.color.gammapedestalgain", &[("blackStretch", num(4.0))], dark)[0] > 0.15);
-        assert!(close(px("ec.color.gammapedestalgain", &[], dark), dark, 1e-6));
-    }
-
-    #[test]
-    fn levels_channel_controls_act_on_their_channel() {
-        let g = [0.5, 0.5, 0.5, 1.0];
-        assert!(close(px("ec.color.levels", &[("channel", Value::Enum(1))], g), g, 1e-6), "the popup alone changes nothing");
-        let r = px("ec.color.levels", &[("redOutWhite", num(0.5))], g);
-        assert!(close(r, [0.25, 0.5, 0.5, 1.0], 1e-5), "{r:?}");
-        let b = px("ec.color.levels", &[("blueGamma", num(2.0)), ("inWhite", num(0.5))], [0.25, 0.25, 0.25, 1.0]);
-        assert!(close(b, [0.5, 0.5, 0.5f32.sqrt(), 1.0], 1e-5), "RGB first, then blue: {b:?}");
-        let a = px("ec.color.levels", &[("alphaOutWhite", num(0.5))], [0.5, 0.5, 0.5, 1.0]);
-        assert!(close(a, [0.25, 0.25, 0.25, 0.5], 1e-5), "{a:?}");
-        // Per-channel clipping follows its own popups.
-        let hot = [0.9, 0.9, 0.9, 1.0];
-        let c = px("ec.color.levels", &[("greenInWhite", num(0.5))], hot)[1];
-        let nc = px("ec.color.levels", &[("greenInWhite", num(0.5)), ("greenClipToOutputWhite", Value::Enum(0))], hot)[1];
-        assert!((c - 1.0).abs() < 1e-6 && (nc - 1.8).abs() < 1e-5, "{c} {nc}");
-    }
-
-    #[test]
-    fn hue_saturation_ranges_adjust_their_hues_only() {
-        let red = [0.8, 0.1, 0.1, 1.0];
-        let blue = [0.1, 0.1, 0.8, 1.0];
-        let grey = [0.5, 0.5, 0.5, 1.0];
-        let v = [("redsSaturation", num(-100.0))];
-        let r = px("ec.color.huesaturation", &v, red);
-        assert!((r[0] - r[1]).abs() < 1e-4, "reds desaturated: {r:?}");
-        assert!(close(px("ec.color.huesaturation", &v, blue), blue, 1e-5));
-        assert!(close(px("ec.color.huesaturation", &v, grey), grey, 1e-5));
-        // Blues hue +120°: blue becomes red.
-        let b = px("ec.color.huesaturation", &[("bluesHue", num(120.0))], blue);
-        assert!(b[0] > 0.7 && b[2] < 0.2, "{b:?}");
-        // Fall-off: a hue 15° past the range end (Reds: −15..15, fall-off 30) gets half.
-        let orange_ish = {
-            let (r, g, b) = hsl_to_rgb(30.0 / 360.0, 0.8, 0.5);
-            [r, g, b, 1.0]
-        };
-        let o = px("ec.color.huesaturation", &[("redsLightness", num(100.0))], orange_ish);
-        let (_, _, l) = rgb_to_hsl(o[0], o[1], o[2]);
-        assert!((l - 0.75).abs() < 0.01, "half weight: {l}");
-        // Moving the range changes which hues it takes.
-        let o2 = px("ec.color.huesaturation", &[("redsLightness", num(100.0)), ("redsRangeEnd", num(40.0))], orange_ish);
-        assert!(rgb_to_hsl(o2[0], o2[1], o2[2]).2 > 0.99);
-        let params = crate::Params { values: [("redsHue".to_string(), num(10.0))].into_iter().collect() };
-        let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [1.0, 1.0], seed: 0, adjustment: false, env: Default::default() };
-        assert!(!huesat_ranges_identity(&ctx));
-    }
-
-    #[test]
-    fn fill_mask_all_masks_feather_and_invert() {
-        let sq = |x0: f64, x1: f64| crate::MaskShape {
-            name: String::new(),
-            points: vec![[x0, 0.0], [x1, 0.0], [x1, 10.0], [x0, 10.0]],
-            closed: true,
-            inverted: false,
-        };
-        let masks = [sq(0.0, 5.0), sq(15.0, 20.0)];
-        let env = EffectEnv { masks: &masks, ..Default::default() };
-        let grey = Image::filled(20, 10, [0.5, 0.5, 0.5, 1.0]);
-        let run = |vals: &[(&str, Value)]| run_fx("ec.generate.fill", vals, grey.clone(), 0.0, env).img;
-        let one = run(&[("fillMask", num(1.0))]);
-        assert_eq!(one.get(2, 5), [1.0, 0.0, 0.0, 1.0]);
-        assert_eq!(one.get(10, 5), [0.5, 0.5, 0.5, 1.0]);
-        assert_eq!(one.get(17, 5), [0.5, 0.5, 0.5, 1.0]);
-        let all = run(&[("allMasks", Value::Bool(true))]);
-        assert_eq!(all.get(17, 5), [1.0, 0.0, 0.0, 1.0]);
-        let inv = run(&[("fillMask", num(1.0)), ("invert", Value::Bool(true))]);
-        assert_eq!(inv.get(2, 5), [0.5, 0.5, 0.5, 1.0]);
-        assert_eq!(inv.get(10, 5), [1.0, 0.0, 0.0, 1.0]);
-        let soft = run(&[("fillMask", num(1.0)), ("horizontalFeather", num(6.0))]);
-        let v = soft.get(6, 5)[1];
-        assert!(v > 0.05 && v < 0.5, "feathered edge {v}");
-        // Without masks, Fill fills the layer as before.
-        let plain = run_fx("ec.generate.fill", &[("fillMask", num(1.0))], grey.clone(), 0.0, EffectEnv::default()).img;
-        assert_eq!(plain.get(10, 5), [1.0, 0.0, 0.0, 1.0]);
-    }
-
-    /// After Effects 2026: Fill (0, 0.5, 1) at Opacity 50 % on an opaque layer (a Gradient Ramp
-    /// on a red solid) renders premultiplied (0, 0.251, 0.502) at alpha 0.502 everywhere: the
-    /// fill colour at half the layer's alpha, nothing of the ramp left.
-    #[test]
-    fn fill_opacity_is_the_layers_opacity_as_in_after_effects() {
-        let mut img = Image::new(16, 4);
-        for x in 0..16 {
-            let v = x as f32 / 15.0;
-            for y in 0..4 {
-                img.set(x, y, [v, 0.0, 0.0, 1.0]);
-            }
-        }
-        let vals = [("color", Value::Color([0.0, 0.5, 1.0, 1.0])), ("opacity", num(50.0))];
-        let out = run_fx("ec.generate.fill", &vals, img, 0.0, EffectEnv::default()).img;
-        for x in [0, 7, 15] {
-            let p = out.get(x, 2);
-            let ae = [0.0, 0.251, 0.502, 0.502];
-            assert!(p.iter().zip(ae).all(|(v, a)| (v - a).abs() < 1.0 / 255.0), "x {x}: {p:?} vs AE {ae:?}");
-        }
-        // A half-transparent pixel ends at a quarter alpha, still the fill colour.
-        let half = run_fx("ec.generate.fill", &vals, Image::filled(2, 2, [0.2, 0.2, 0.2, 0.5]), 0.0, EffectEnv::default()).img;
-        assert_eq!(half.get(0, 0), [0.0, 0.125, 0.25, 0.25]);
-    }
-
-    #[test]
-    fn colorama_palettes_modify_selection_masking_and_add_phase() {
-        let grey = [0.5, 0.5, 0.5, 1.0];
-        let red = [1.0, 0.0, 0.0, 1.0];
-        // Ramp Grayscale: intensity 0.5 maps to mid grey.
-        let g = px("ec.color.colorama", &[("outputCycle/usePresetPalette", Value::Enum(1))], grey);
-        assert!((g[0] - 0.5).abs() < 0.01 && (g[0] - g[2]).abs() < 1e-5, "{g:?}");
-        // Custom palette: two stops, black at 0 and blue at 0.5.
-        let custom = [("outputCycle/usePresetPalette", Value::Enum(8)), ("outputCycle/palette", Value::Str("0:0,0,0 0.5:0,0,1".into()))];
-        let c = px("ec.color.colorama", &custom, grey);
-        assert!(c[2] > 0.99 && c[0] < 0.01, "{c:?}");
-        // Modify Lightness keeps the hue of the pixel (red stays red).
-        let l = px("ec.color.colorama", &[("modify/modify", Value::Enum(5)), ("outputCycle/usePresetPalette", Value::Enum(1))], red);
-        assert!(l[0] > l[1] + 0.2 && l[1] < 0.01 + l[2] + 1e-4, "{l:?}");
-        // Pixel Selection: only colours near Matching Color change.
-        let sel = [
-            ("pixelSelection/matchingMode", Value::Enum(1)),
-            ("pixelSelection/matchingColor", col(1.0, 0.0, 0.0)),
-            ("pixelSelection/matchingTolerance", num(10.0)),
-        ];
-        assert!(close(px("ec.color.colorama", &sel, grey), grey, 1e-6));
-        assert!(!close(px("ec.color.colorama", &sel, red), red, 1e-3));
-        // Composite Over Layer off: unselected pixels vanish.
-        let mut off = sel.to_vec();
-        off.push(("masking/compositeOverLayer", Value::Bool(false)));
-        assert_eq!(px("ec.color.colorama", &off, grey)[3], 0.0);
-        // Modify Alpha takes the palette alpha.
-        let alpha = [
-            ("outputCycle/usePresetPalette", Value::Enum(8)),
-            ("outputCycle/palette", Value::Str("0:1,1,1,0.25".into())),
-            ("modify/modifyAlpha", Value::Bool(true)),
-        ];
-        assert!((px("ec.color.colorama", &alpha, grey)[3] - 0.25).abs() < 1e-5);
-        // Palette parsing and evaluation.
-        let p = ColoramaPalette::parse("0.5:0,0,1 0:1,0,0").unwrap();
-        assert_eq!(p.eval(0.25, true), [0.5, 0.0, 0.5, 1.0]);
-        assert_eq!(p.eval(0.75, true), [0.5, 0.0, 0.5, 1.0], "wraps around");
-        assert_eq!(p.eval(0.25, false), [1.0, 0.0, 0.0, 1.0]);
-    }
-}
+mod tests;
diff --git a/crates/effects/src/color_fx/tests.rs b/crates/effects/src/color_fx/tests.rs
new file mode 100644
index 000000000..2f3370204
--- /dev/null
+++ b/crates/effects/src/color_fx/tests.rs
@@ -0,0 +1,508 @@
+use super::*;
+use crate::{EffectEnv, run_fx};
+use effectcraft_raster::Image;
+
+fn px(id: &str, vals: &[(&str, Value)], c: [f32; 4]) -> [f32; 4] {
+    run_fx(id, vals, Image::filled(2, 2, c), 0.0, EffectEnv::default()).img.get(0, 0)
+}
+fn close(a: [f32; 4], b: [f32; 4], eps: f32) -> bool {
+    a.iter().zip(b).all(|(x, y)| (x - y).abs() <= eps)
+}
+
+/// Projects saved before Use Legacy / the Photo Filter menu existed keep rendering as before.
+#[test]
+fn old_saves_get_legacy_values_for_added_params() {
+    use effectcraft_project::build::Ids;
+    let mut next = 1;
+    for (id, param, want) in
+        [("ec.color.brightnesscontrast", "useLegacy", Value::Bool(true)), ("ec.color.photofilter", "filter", Value::Enum(PHOTO_FILTER_CUSTOM))]
+    {
+        let spec = crate::find(id).unwrap();
+        let mut g = crate::instantiate(spec, &mut Ids(&mut next), spec.name, [10.0, 10.0]);
+        g.children.retain(|c| c.match_id() != param);
+        crate::migrate::upgrade_instance(spec, &mut g, &mut Ids(&mut next), [10.0, 10.0]);
+        assert_eq!(g.get(param).unwrap().value, want, "{id}");
+    }
+}
+
+/// After Effects 2026 renders of full-frame solids with Tint at its defaults (sRGB working
+/// space, not linearised, 32 bpc, 8-bit capture): Rec. 601 weights on the encoded values.
+#[test]
+fn tint_defaults_match_after_effects_greys() {
+    for (c, want) in [([1.0, 0.0, 0.0], 76.0), ([0.0, 1.0, 0.0], 150.0), ([0.0, 0.0, 1.0], 29.0), ([0.5, 0.5, 0.5], 128.0)] {
+        let o = px("ec.color.tint", &[], [c[0], c[1], c[2], 1.0]);
+        let want = want / 255.0;
+        assert!(close(o, [want, want, want, 1.0], 1.0 / 255.0), "{c:?}: {o:?} vs {want}");
+    }
+}
+
+#[test]
+fn colorama_reads_get_phase_from() {
+    // Same intensity, different red: Intensity gives one colour, Red gives two.
+    let a = [0.6, 0.2, 0.2, 1.0];
+    let b = [0.2, 0.2, 0.6, 1.0];
+    let red = |c| px("ec.color.colorama", &[("inputPhase/mode", Value::Enum(1))], c);
+    assert!(!close(red(a), red(b), 1e-3));
+    // Zero maps everything to the start of the cycle (red).
+    assert!(close(px("ec.color.colorama", &[("inputPhase/mode", Value::Enum(9))], b), [1.0, 0.0, 0.0, 1.0], 1e-5));
+    // Interpolate Palette off posterizes: two nearby inputs land on the same colour.
+    let off = |v: f32| px("ec.color.colorama", &[("outputCycle/interpolatePalette", Value::Bool(false))], [v, v, v, 1.0]);
+    assert_eq!(off(0.20), off(0.22));
+}
+
+#[test]
+fn brightness_contrast_modern_keeps_black_and_white_and_legacy_is_linear() {
+    let bc = |vals: &[(&str, Value)], v: f32| px("ec.color.brightnesscontrast", vals, [v, v, v, 1.0])[0];
+    let up = [("brightness", num(50.0)), ("contrast", num(40.0))];
+    assert_eq!(bc(&up, 0.0), 0.0);
+    assert!((bc(&up, 1.0) - 1.0).abs() < 1e-6);
+    assert!(bc(&up, 0.4) > 0.4);
+    let legacy = [("brightness", num(50.0)), ("useLegacy", Value::Bool(true))];
+    assert!((bc(&legacy, 0.2) - 0.7).abs() < 1e-5);
+    assert!((bc(&legacy, 0.0) - 0.5).abs() < 1e-5);
+}
+
+/// After Effects non-legacy ramps (kasper9n, #681). B0 C-100 matched B0 C-50 and is omitted.
+#[test]
+fn brightness_contrast_modern_matches_ae_ramp_samples() {
+    let u8 = |v: f32| (v * 255.0).round() as i32;
+    let go = |b: f64, c: f64, x: u8| {
+        u8(px("ec.color.brightnesscontrast", &[("brightness", num(b)), ("contrast", num(c))], [x as f32 / 255.0, x as f32 / 255.0, x as f32 / 255.0, 1.0])[0])
+    };
+    // (brightness, contrast, input, AE 8-bit)
+    let samples: &[(f64, f64, u8, u8)] = &[
+        (0.0, 100.0, 64, 40),
+        (0.0, 100.0, 128, 129),
+        (0.0, 100.0, 192, 217),
+        (0.0, 50.0, 64, 53),
+        (0.0, 50.0, 192, 205),
+        (0.0, -50.0, 64, 77),
+        (100.0, 0.0, 128, 209),
+        (50.0, 0.0, 128, 171),
+        (106.0, -18.0, 128, 214),
+    ];
+    for &(b, c, x, ae) in samples {
+        let got = go(b, c, x);
+        assert!((got - ae as i32).abs() <= 10, "B{b} C{c} in {x}: got {got} AE {ae}");
+    }
+    // Old g=4 S-curve put Contrast 100 at ~8/255 here.
+    assert!(go(0.0, 100.0, 64) >= 30);
+}
+
+/// After Effects 2026: Tritone Highlights [1, 1, 0.8], Midtones [0.6, 0.2, 0.2], Shadows
+/// [0, 0, 0.3]. On a red solid with Blend With Original 25 (case 718) AE gives (132, 23, 46);
+/// on a grey ramp (case 815) levels 0, 63.9, 127.6, 191.4 give (0, 0, 77), (77, 26, 64),
+/// (153, 51, 51), (204, 153, 128).
+#[test]
+fn tritone_matches_after_effects() {
+    let colours =
+        [("highlights", Value::Color([1.0, 1.0, 0.8, 1.0])), ("midtones", Value::Color([0.6, 0.2, 0.2, 1.0])), ("shadows", Value::Color([0.0, 0.0, 0.3, 1.0]))];
+    let near = |o: [f32; 4], ae: [f32; 3]| (0..3).all(|i| (o[i] * 255.0 - ae[i]).abs() <= 1.0);
+    let mut red = colours.to_vec();
+    red.push(("blend", num(25.0)));
+    let o = px("ec.color.tritone", &red, [1.0, 0.0, 0.0, 1.0]);
+    assert!(near(o, [132.0, 23.0, 46.0]), "{:?}", o.map(|v| v * 255.0));
+    for (level, ae) in [(0.1f32, [0.0, 0.0, 77.0]), (63.9, [77.0, 26.0, 64.0]), (127.6, [153.0, 51.0, 51.0]), (191.4, [204.0, 153.0, 128.0])] {
+        let v = level / 255.0;
+        let o = px("ec.color.tritone", &colours, [v, v, v, 1.0]);
+        assert!(near(o, ae), "level {level}: {:?} vs {ae:?}", o.map(|v| v * 255.0));
+    }
+}
+
+/// After Effects 2026, Tint Color [1, 0.5, 0]: a red solid at Reds 10 (case 717) and yellow
+/// and white solids at the default sliders (case 825).
+#[test]
+fn black_white_tint_matches_after_effects() {
+    let tint = [("tint", Value::Bool(true)), ("tintColor", Value::Color([1.0, 0.5, 0.0, 1.0]))];
+    let near = |o: [f32; 4], ae: [f32; 3]| (0..3).all(|i| (o[i] * 255.0 - ae[i]).abs() <= 1.5);
+    let mut reds = tint.to_vec();
+    reds.push(("reds", num(10.0)));
+    let o = px("ec.color.blackwhite", &reds, [1.0, 0.0, 0.0, 1.0]);
+    assert!(near(o, [43.0, 21.0, 0.0]), "{:?}", o.map(|v| v * 255.0));
+    let o = px("ec.color.blackwhite", &tint, [1.0, 1.0, 0.0, 1.0]);
+    assert!(near(o, [255.0, 129.0, 2.0]), "{:?}", o.map(|v| v * 255.0));
+    let o = px("ec.color.blackwhite", &tint, [1.0, 1.0, 1.0, 1.0]);
+    assert!(near(o, [255.0, 255.0, 255.0]), "{:?}", o.map(|v| v * 255.0));
+    // Hostile grays stay finite.
+    for g in [f32::NAN, -1.0, 0.0, 4.0] {
+        assert!(bw_tint([1.0, 0.5, 0.0], g).iter().all(|v| v.is_finite()));
+    }
+}
+
+/// After Effects 2026 ramps (RENDERER round 2, session R8): negative Brightness and Contrast
+/// are the inverses of the positive curves. (brightness, contrast, input, AE 8-bit)
+#[test]
+fn negative_brightness_and_contrast_invert_the_positive_curves() {
+    let go = |b: f64, c: f64, x: u8| {
+        let v = x as f32 / 255.0;
+        (px("ec.color.brightnesscontrast", &[("brightness", num(b)), ("contrast", num(c))], [v, v, v, 1.0])[0] * 255.0).round() as i32
+    };
+    let samples: &[(f64, f64, u8, u8)] = &[
+        (-40.0, 0.0, 64, 50),
+        (-40.0, 0.0, 128, 99),
+        (-40.0, 0.0, 191, 155),
+        (-40.0, 0.0, 234, 207),
+        (0.0, -50.0, 21, 28),
+        (0.0, -50.0, 64, 76),
+        (0.0, -50.0, 191, 179),
+        (0.0, -50.0, 234, 227),
+        (40.0, 0.0, 128, 162),
+        (0.0, 50.0, 64, 52),
+    ];
+    for &(b, c, x, ae) in samples {
+        let got = go(b, c, x);
+        assert!((got - ae as i32).abs() <= 7, "B{b} C{c} in {x}: got {got} AE {ae}");
+    }
+}
+
+/// #1463: Black & White's sliders set the gray of each pure hue and blend between
+/// neighbouring hues; neutral pixels keep their value, overbright ones too, and an overbright
+/// colour stays finite (it used to divide by zero).
+#[test]
+fn black_white_sliders_set_the_gray_of_each_hue() {
+    let bw = |vals: &[(&str, Value)], c: [f32; 3]| px("ec.color.blackwhite", vals, [c[0], c[1], c[2], 1.0]);
+    let gray = |v: f32| [v, v, v, 1.0];
+    // The defaults: Reds 40, Yellows 60, Greens 40, Cyans 60, Blues 20, Magentas 80 (%).
+    let hues = [
+        ([1.0, 0.0, 0.0], 0.4),
+        ([1.0, 1.0, 0.0], 0.6),
+        ([0.0, 1.0, 0.0], 0.4),
+        ([0.0, 1.0, 1.0], 0.6),
+        ([0.0, 0.0, 1.0], 0.2),
+        ([1.0, 0.0, 1.0], 0.8),
+        // Half as bright, half the gray; orange is halfway from Reds to Yellows.
+        ([0.5, 0.0, 0.0], 0.2),
+        ([1.0, 0.5, 0.0], 0.5),
+        // Neutral pixels keep their value.
+        ([0.3, 0.3, 0.3], 0.3),
+        ([4.0, 4.0, 4.0], 4.0),
+        // An overbright red: its smallest channel plus its chroma at Reds' 40 %.
+        ([1.5, 0.5, 0.5], 0.9),
+    ];
+    for (c, want) in hues {
+        let o = bw(&[], c);
+        assert!(close(o, gray(want), 1e-5), "{c:?}: {o:?}, want {want}");
+    }
+    assert!(close(bw(&[("reds", num(120.0))], [1.0, 0.0, 0.0]), gray(1.2), 1e-5));
+    assert!(close(bw(&[("reds", num(-200.0))], [1.0, 0.0, 0.0]), gray(0.0), 1e-5));
+    assert!(close(bw(&[("blues", num(300.0))], [0.1, 0.1, 0.3]), gray(0.7), 1e-5));
+}
+
+/// #1463: faint colour noise stays faint. The shadows of compressed footage carry a code or
+/// two of colour noise, which Black & White turned into bright and black blocks (the HSL
+/// saturation it scaled is near 1 for any tinted near-black pixel). At 8, 16 and 32 bpc the
+/// gray of a dark ramp with ±2 steps of colour noise stays within 2 steps of the clean ramp's.
+#[test]
+fn black_white_keeps_faint_colour_noise_faint() {
+    // A step of 8 bpc, of 16 bpc (After Effects' 0..32768), and a small 32-bpc float one.
+    for step in [1.0 / 255.0, 1.0 / 32768.0, 1e-3_f32] {
+        let (w, h) = (64u32, 4u32);
+        let (mut clean, mut noisy) = (Image::new(w, h), Image::new(w, h));
+        for y in 0..h {
+            for x in 0..w {
+                // A dark ramp up to a quarter gray, in whole steps...
+                let v = (x as f32 / w as f32 * 0.25 / step).round() * step;
+                // ...and up to ±2 steps of noise per channel, mixed differently in each pixel.
+                let n = |k: u32| (((x * 7 + y * 13 + k * 2) % 5) as f32 - 2.0) * step;
+                clean.set(x, y, [v, v, v, 1.0]);
+                noisy.set(x, y, [(v + n(0)).max(0.0), (v + n(1)).max(0.0), (v + n(2)).max(0.0), 1.0]);
+            }
+        }
+        let bw = |img| run_fx("ec.color.blackwhite", &[], img, 0.0, EffectEnv::default()).img;
+        let (a, b) = (bw(clean), bw(noisy));
+        let worst = a.data.iter().zip(&b.data).map(|(p, q)| (p[0] - q[0]).abs()).fold(0.0, f32::max);
+        assert!(worst <= 2.0 * step + 1e-6, "step {step}: the noise moved the gray by {} steps", worst / step);
+    }
+}
+
+#[test]
+fn levels_clips_black_and_white_independently() {
+    let lv = |vals: &[(&str, Value)], v: f32| px("ec.color.levels", vals, [v, v, v, 1.0])[0];
+    let base = [("inBlack", num(0.2)), ("inWhite", num(0.6)), ("outBlack", num(0.1)), ("outWhite", num(0.9))];
+    assert!((lv(&base, 0.9) - 0.9).abs() < 1e-5);
+    let mut no_white = base.to_vec();
+    no_white.push(("clipToOutputWhite", Value::Enum(0)));
+    assert!(lv(&no_white, 0.9) > 0.9);
+    assert!((lv(&no_white, 0.0) - 0.1).abs() < 1e-5);
+    // The hidden switch of older projects turns both off.
+    let mut legacy = base.to_vec();
+    legacy.push(("noClip", Value::Bool(true)));
+    assert!(lv(&legacy, 0.9) > 0.9);
+}
+
+#[test]
+fn exposure_individual_channels_and_bypass() {
+    let g = [0.5, 0.5, 0.5, 1.0];
+    let one = px("ec.color.exposure", &[("channels", Value::Enum(1)), ("red/redExposure", num(1.0))], g);
+    assert!(one[0] > 0.6 && (one[1] - 0.5).abs() < 1e-5 && (one[2] - 0.5).abs() < 1e-5);
+    // Master values are ignored in Individual Channels mode.
+    assert!(close(px("ec.color.exposure", &[("channels", Value::Enum(1)), ("master/exposure", num(2.0))], g), g, 1e-5));
+    // Bypass Linear Light Conversion: +1 stop doubles the raw value.
+    let raw = px("ec.color.exposure", &[("master/exposure", num(1.0)), ("bypassLinearLight", Value::Bool(true))], [0.25, 0.25, 0.25, 1.0]);
+    assert!((raw[0] - 0.5).abs() < 1e-5);
+    // Negative results are mirrored, not clipped.
+    let neg =
+        px("ec.color.exposure", &[("master/offset", num(-0.5)), ("bypassLinearLight", Value::Bool(true)), ("master/gamma", num(2.0))], [0.25, 0.25, 0.25, 1.0]);
+    assert!((neg[0] + 0.5).abs() < 1e-4, "{neg:?}");
+}
+
+/// After Effects' Exposure ranges for all twelve sliders; a saved value outside them (a gamma
+/// of 0.05, valid before, as in Photoshop) survives loading and still renders.
+#[test]
+fn exposure_has_after_effects_ranges_and_keeps_old_values() {
+    use effectcraft_project::build::Ids;
+    let spec = crate::find("ec.color.exposure").unwrap();
+    let want = [(-100.0, 100.0, -4.0, 4.0, 2), (-2.0, 2.0, -0.5, 0.5, 4), (0.1, 10.0, 0.1, 10.0, 2)];
+    let sliders: Vec<_> = spec
+        .params
+        .iter()
+        .filter_map(|p| match p.ui {
+            ParamUi::Slider { min, max, slider_min, slider_max, decimals } => Some((p.id, (min, max, slider_min, slider_max, decimals))),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(sliders.len(), 12);
+    for (i, (id, r)) in sliders.iter().enumerate() {
+        assert_eq!(*r, want[i % 3], "{id}");
+    }
+    let mut next = 1;
+    let mut g = crate::instantiate(spec, &mut Ids(&mut next), spec.name, [10.0, 10.0]);
+    let gamma = g.prop_mut("master/gamma").unwrap();
+    gamma.value = num(0.05);
+    gamma.ui = slider(0.01, 9.99, 0.1, 3.0, 2);
+    crate::migrate::upgrade_instance(spec, &mut g, &mut Ids(&mut next), [10.0, 10.0]);
+    let gamma = g.prop_mut("master/gamma").unwrap();
+    assert_eq!(gamma.value, num(0.05));
+    assert!(matches!(gamma.ui, ParamUi::Slider { min, .. } if min == 0.1));
+    let o = px("ec.color.exposure", &[("master/gamma", num(0.05)), ("bypassLinearLight", Value::Bool(true))], [0.5, 0.5, 0.5, 1.0]);
+    assert!((o[0] - 0.5f32.powf(20.0)).abs() < 1e-9, "{o:?}");
+}
+
+/// Exposure on a red [1, 0, 0] solid against After Effects 2026 renders (sRGB working space,
+/// not linearised, 32 bpc, 8-bit captures): the linear-light conversion is a pure 2.2 power.
+/// The piecewise sRGB curve gave 2 / 7 / 39 for the three smallest Offsets.
+#[test]
+fn exposure_matches_after_effects_gamma_2_2() {
+    let red = [1.0, 0.0, 0.0, 1.0];
+    let code = |o: [f32; 4], i: usize| o[i] * 255.0;
+    // Master Offset only: G and B carry the curve; R goes over 1 (255 in the 8-bit capture).
+    for (offset, ae) in [(0.0005, 8.0), (0.002, 15.0), (0.02, 43.0), (0.1, 90.0)] {
+        let o = px("ec.color.exposure", &[("master/offset", num(offset))], red);
+        for i in [1, 2] {
+            assert!((code(o, i) - ae).abs() <= 1.0, "offset {offset}: {} vs AE {ae}", code(o, i));
+        }
+        assert!(o[0] >= 1.0, "{o:?}");
+    }
+    // Exposure −2.25: AE 126; with Bypass Linear Light Conversion (gain on encoded values) 54.
+    let o = px("ec.color.exposure", &[("master/exposure", num(-2.25))], red);
+    assert!((code(o, 0) - 126.0).abs() <= 1.0 && o[1] == 0.0, "{o:?}");
+    let o = px("ec.color.exposure", &[("master/exposure", num(-2.25)), ("bypassLinearLight", Value::Bool(true))], red);
+    assert!((code(o, 0) - 54.0).abs() <= 1.0 && o[1] == 0.0, "{o:?}");
+    // Default settings leave 32-bpc values alone, negative and over-range ones included.
+    let hdr = [-0.25, 0.5, 2.0, 1.0];
+    assert!(close(px("ec.color.exposure", &[], hdr), hdr, 1e-5));
+    // A negative Offset pushes black below zero, mirrored, rather than clipping or NaN.
+    let o = px("ec.color.exposure", &[("master/offset", num(-0.02))], [0.0, 0.0, 0.0, 1.0]);
+    assert!((o[0] + 0.02f32.powf(1.0 / 2.2)).abs() < 1e-5, "{o:?}");
+}
+
+#[test]
+fn change_to_color_change_modes_tolerances_and_matte() {
+    let red = [0.8, 0.1, 0.1, 1.0];
+    let green = [0.1, 0.8, 0.1, 1.0];
+    let base = [("from", col(0.8, 0.1, 0.1)), ("to", col(0.1, 0.1, 0.8))];
+    // Hue only: red turns blue with its own lightness / saturation; green is untouched.
+    let o = px("ec.color.changetocolor", &base, red);
+    assert!(o[2] > 0.7 && o[0] < 0.2, "{o:?}");
+    assert!(close(px("ec.color.changetocolor", &base, green), green, 1e-5));
+    // The matte is white where matched, black elsewhere.
+    let mut m = base.to_vec();
+    m.push(("viewCorrectionMatte", Value::Bool(true)));
+    assert!(close(px("ec.color.changetocolor", &m, red), [1.0, 1.0, 1.0, 1.0], 1e-5));
+    assert!(close(px("ec.color.changetocolor", &m, green), [0.0, 0.0, 0.0, 1.0], 1e-5));
+    // A lightness tolerance of 0 rejects a lighter red.
+    let mut strict = m.clone();
+    strict.push(("toleranceGroup/lightness", num(0.0)));
+    strict.push(("softness", num(0.0)));
+    assert!(close(px("ec.color.changetocolor", &strict, [1.0, 0.5, 0.5, 1.0]), [0.0, 0.0, 0.0, 1.0], 1e-5));
+    // Hue, Lightness & Saturation, set: a matched pixel becomes the To colour.
+    let mut all = base.to_vec();
+    all.push(("change", Value::Enum(3)));
+    assert!(close(px("ec.color.changetocolor", &all, red), [0.1, 0.1, 0.8, 1.0], 1e-4));
+}
+
+#[test]
+fn leave_color_tolerance_softness_and_match_mode() {
+    let green = [0.1, 0.8, 0.1, 1.0];
+    let lc = |vals: &[(&str, Value)]| {
+        let mut v = vec![("amount", num(100.0))];
+        v.extend_from_slice(vals);
+        px("ec.color.leavecolor", &v, green)
+    };
+    let g = luminance(0.1, 0.8, 0.1);
+    assert!(close(lc(&[]), [g, g, g, 1.0], 1e-5));
+    assert!(close(lc(&[("tolerance", num(100.0))]), green, 1e-6));
+    // Softness keeps part of the colour.
+    let s = lc(&[("tolerance", num(10.0)), ("edgeSoftness", num(100.0))]);
+    assert!(s[1] > g + 0.05 && s[1] < 0.8);
+    // Using Hue: a dark red still matches pure red.
+    let dark = px("ec.color.leavecolor", &[("amount", num(100.0)), ("tolerance", num(5.0)), ("matchColors", Value::Enum(1))], [0.4, 0.0, 0.0, 1.0]);
+    assert!(close(dark, [0.4, 0.0, 0.0, 1.0], 1e-6));
+}
+
+#[test]
+fn photo_filter_presets_and_custom() {
+    let g = [0.5, 0.5, 0.5, 1.0];
+    let cool = px("ec.color.photofilter", &[("filter", Value::Enum(3)), ("preserveLuminosity", Value::Bool(false))], g);
+    assert!(cool[2] > cool[0], "a cooling filter is blue: {cool:?}");
+    let custom = |c| px("ec.color.photofilter", &[("filter", Value::Enum(PHOTO_FILTER_CUSTOM)), ("color", c)], g);
+    assert!(custom(col(0.0, 1.0, 0.0))[1] > custom(col(1.0, 0.0, 0.0))[1]);
+    // The Color swatch is ignored by the presets.
+    let warm = |c| px("ec.color.photofilter", &[("color", c)], g);
+    assert_eq!(warm(col(0.0, 1.0, 0.0)), warm(col(1.0, 0.0, 0.0)));
+}
+
+#[test]
+fn color_balance_preserve_luminosity_and_black_stretch() {
+    let g = [0.5, 0.5, 0.5, 1.0];
+    let o = px("ec.color.colorbalance", &[("midRed", num(60.0)), ("preserveLuminosity", Value::Bool(true))], g);
+    assert!((luminance(o[0], o[1], o[2]) - 0.5).abs() < 1e-4 && o[0] > o[2]);
+    let dark = [0.1, 0.1, 0.1, 1.0];
+    assert!(px("ec.color.gammapedestalgain", &[("blackStretch", num(4.0))], dark)[0] > 0.15);
+    assert!(close(px("ec.color.gammapedestalgain", &[], dark), dark, 1e-6));
+}
+
+#[test]
+fn levels_channel_controls_act_on_their_channel() {
+    let g = [0.5, 0.5, 0.5, 1.0];
+    assert!(close(px("ec.color.levels", &[("channel", Value::Enum(1))], g), g, 1e-6), "the popup alone changes nothing");
+    let r = px("ec.color.levels", &[("redOutWhite", num(0.5))], g);
+    assert!(close(r, [0.25, 0.5, 0.5, 1.0], 1e-5), "{r:?}");
+    let b = px("ec.color.levels", &[("blueGamma", num(2.0)), ("inWhite", num(0.5))], [0.25, 0.25, 0.25, 1.0]);
+    assert!(close(b, [0.5, 0.5, 0.5f32.sqrt(), 1.0], 1e-5), "RGB first, then blue: {b:?}");
+    let a = px("ec.color.levels", &[("alphaOutWhite", num(0.5))], [0.5, 0.5, 0.5, 1.0]);
+    assert!(close(a, [0.25, 0.25, 0.25, 0.5], 1e-5), "{a:?}");
+    // Per-channel clipping follows its own popups.
+    let hot = [0.9, 0.9, 0.9, 1.0];
+    let c = px("ec.color.levels", &[("greenInWhite", num(0.5))], hot)[1];
+    let nc = px("ec.color.levels", &[("greenInWhite", num(0.5)), ("greenClipToOutputWhite", Value::Enum(0))], hot)[1];
+    assert!((c - 1.0).abs() < 1e-6 && (nc - 1.8).abs() < 1e-5, "{c} {nc}");
+}
+
+#[test]
+fn hue_saturation_ranges_adjust_their_hues_only() {
+    let red = [0.8, 0.1, 0.1, 1.0];
+    let blue = [0.1, 0.1, 0.8, 1.0];
+    let grey = [0.5, 0.5, 0.5, 1.0];
+    let v = [("redsSaturation", num(-100.0))];
+    let r = px("ec.color.huesaturation", &v, red);
+    assert!((r[0] - r[1]).abs() < 1e-4, "reds desaturated: {r:?}");
+    assert!(close(px("ec.color.huesaturation", &v, blue), blue, 1e-5));
+    assert!(close(px("ec.color.huesaturation", &v, grey), grey, 1e-5));
+    // Blues hue +120°: blue becomes red.
+    let b = px("ec.color.huesaturation", &[("bluesHue", num(120.0))], blue);
+    assert!(b[0] > 0.7 && b[2] < 0.2, "{b:?}");
+    // Fall-off: a hue 15° past the range end (Reds: −15..15, fall-off 30) gets half.
+    let orange_ish = {
+        let (r, g, b) = hsl_to_rgb(30.0 / 360.0, 0.8, 0.5);
+        [r, g, b, 1.0]
+    };
+    let o = px("ec.color.huesaturation", &[("redsLightness", num(100.0))], orange_ish);
+    let (_, _, l) = rgb_to_hsl(o[0], o[1], o[2]);
+    assert!((l - 0.75).abs() < 0.01, "half weight: {l}");
+    // Moving the range changes which hues it takes.
+    let o2 = px("ec.color.huesaturation", &[("redsLightness", num(100.0)), ("redsRangeEnd", num(40.0))], orange_ish);
+    assert!(rgb_to_hsl(o2[0], o2[1], o2[2]).2 > 0.99);
+    let params = crate::Params { values: [("redsHue".to_string(), num(10.0))].into_iter().collect() };
+    let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [1.0, 1.0], seed: 0, adjustment: false, env: Default::default() };
+    assert!(!huesat_ranges_identity(&ctx));
+}
+
+#[test]
+fn fill_mask_all_masks_feather_and_invert() {
+    let sq =
+        |x0: f64, x1: f64| crate::MaskShape { name: String::new(), points: vec![[x0, 0.0], [x1, 0.0], [x1, 10.0], [x0, 10.0]], closed: true, inverted: false };
+    let masks = [sq(0.0, 5.0), sq(15.0, 20.0)];
+    let env = EffectEnv { masks: &masks, ..Default::default() };
+    let grey = Image::filled(20, 10, [0.5, 0.5, 0.5, 1.0]);
+    let run = |vals: &[(&str, Value)]| run_fx("ec.generate.fill", vals, grey.clone(), 0.0, env).img;
+    let one = run(&[("fillMask", num(1.0))]);
+    assert_eq!(one.get(2, 5), [1.0, 0.0, 0.0, 1.0]);
+    assert_eq!(one.get(10, 5), [0.5, 0.5, 0.5, 1.0]);
+    assert_eq!(one.get(17, 5), [0.5, 0.5, 0.5, 1.0]);
+    let all = run(&[("allMasks", Value::Bool(true))]);
+    assert_eq!(all.get(17, 5), [1.0, 0.0, 0.0, 1.0]);
+    let inv = run(&[("fillMask", num(1.0)), ("invert", Value::Bool(true))]);
+    assert_eq!(inv.get(2, 5), [0.5, 0.5, 0.5, 1.0]);
+    assert_eq!(inv.get(10, 5), [1.0, 0.0, 0.0, 1.0]);
+    let soft = run(&[("fillMask", num(1.0)), ("horizontalFeather", num(6.0))]);
+    let v = soft.get(6, 5)[1];
+    assert!(v > 0.05 && v < 0.5, "feathered edge {v}");
+    // Without masks, Fill fills the layer as before.
+    let plain = run_fx("ec.generate.fill", &[("fillMask", num(1.0))], grey.clone(), 0.0, EffectEnv::default()).img;
+    assert_eq!(plain.get(10, 5), [1.0, 0.0, 0.0, 1.0]);
+}
+
+/// After Effects 2026: Fill (0, 0.5, 1) at Opacity 50 % on an opaque layer (a Gradient Ramp
+/// on a red solid) renders premultiplied (0, 0.251, 0.502) at alpha 0.502 everywhere: the
+/// fill colour at half the layer's alpha, nothing of the ramp left.
+#[test]
+fn fill_opacity_is_the_layers_opacity_as_in_after_effects() {
+    let mut img = Image::new(16, 4);
+    for x in 0..16 {
+        let v = x as f32 / 15.0;
+        for y in 0..4 {
+            img.set(x, y, [v, 0.0, 0.0, 1.0]);
+        }
+    }
+    let vals = [("color", Value::Color([0.0, 0.5, 1.0, 1.0])), ("opacity", num(50.0))];
+    let out = run_fx("ec.generate.fill", &vals, img, 0.0, EffectEnv::default()).img;
+    for x in [0, 7, 15] {
+        let p = out.get(x, 2);
+        let ae = [0.0, 0.251, 0.502, 0.502];
+        assert!(p.iter().zip(ae).all(|(v, a)| (v - a).abs() < 1.0 / 255.0), "x {x}: {p:?} vs AE {ae:?}");
+    }
+    // A half-transparent pixel ends at a quarter alpha, still the fill colour.
+    let half = run_fx("ec.generate.fill", &vals, Image::filled(2, 2, [0.2, 0.2, 0.2, 0.5]), 0.0, EffectEnv::default()).img;
+    assert_eq!(half.get(0, 0), [0.0, 0.125, 0.25, 0.25]);
+}
+
+#[test]
+fn colorama_palettes_modify_selection_masking_and_add_phase() {
+    let grey = [0.5, 0.5, 0.5, 1.0];
+    let red = [1.0, 0.0, 0.0, 1.0];
+    // Ramp Grayscale: intensity 0.5 maps to mid grey.
+    let g = px("ec.color.colorama", &[("outputCycle/usePresetPalette", Value::Enum(1))], grey);
+    assert!((g[0] - 0.5).abs() < 0.01 && (g[0] - g[2]).abs() < 1e-5, "{g:?}");
+    // Custom palette: two stops, black at 0 and blue at 0.5.
+    let custom = [("outputCycle/usePresetPalette", Value::Enum(8)), ("outputCycle/palette", Value::Str("0:0,0,0 0.5:0,0,1".into()))];
+    let c = px("ec.color.colorama", &custom, grey);
+    assert!(c[2] > 0.99 && c[0] < 0.01, "{c:?}");
+    // Modify Lightness keeps the hue of the pixel (red stays red).
+    let l = px("ec.color.colorama", &[("modify/modify", Value::Enum(5)), ("outputCycle/usePresetPalette", Value::Enum(1))], red);
+    assert!(l[0] > l[1] + 0.2 && l[1] < 0.01 + l[2] + 1e-4, "{l:?}");
+    // Pixel Selection: only colours near Matching Color change.
+    let sel = [
+        ("pixelSelection/matchingMode", Value::Enum(1)),
+        ("pixelSelection/matchingColor", col(1.0, 0.0, 0.0)),
+        ("pixelSelection/matchingTolerance", num(10.0)),
+    ];
+    assert!(close(px("ec.color.colorama", &sel, grey), grey, 1e-6));
+    assert!(!close(px("ec.color.colorama", &sel, red), red, 1e-3));
+    // Composite Over Layer off: unselected pixels vanish.
+    let mut off = sel.to_vec();
+    off.push(("masking/compositeOverLayer", Value::Bool(false)));
+    assert_eq!(px("ec.color.colorama", &off, grey)[3], 0.0);
+    // Modify Alpha takes the palette alpha.
+    let alpha = [
+        ("outputCycle/usePresetPalette", Value::Enum(8)),
+        ("outputCycle/palette", Value::Str("0:1,1,1,0.25".into())),
+        ("modify/modifyAlpha", Value::Bool(true)),
+    ];
+    assert!((px("ec.color.colorama", &alpha, grey)[3] - 0.25).abs() < 1e-5);
+    // Palette parsing and evaluation.
+    let p = ColoramaPalette::parse("0.5:0,0,1 0:1,0,0").unwrap();
+    assert_eq!(p.eval(0.25, true), [0.5, 0.0, 0.5, 1.0]);
+    assert_eq!(p.eval(0.75, true), [0.5, 0.0, 0.5, 1.0], "wraps around");
+    assert_eq!(p.eval(0.25, false), [1.0, 0.0, 0.0, 1.0]);
+}
diff --git a/crates/effects/src/distort.rs b/crates/effects/src/distort.rs
index 534da8061..916e162f6 100644
--- a/crates/effects/src/distort.rs
+++ b/crates/effects/src/distort.rs
@@ -275,27 +275,70 @@ pub fn transform_shutter(ctx: &EffectCtx) -> Option<(f64, f64, u32)> {
     (angle > 0.0).then_some((angle, phase, n.clamp(2, 64)))
 }
 
-fn transform_matrix(pr: &crate::Params, b: &Buf) -> Mat3 {
-    let anchor = b.to_px(pr.v2("anchor"));
-    let pos = b.to_px(pr.v2("position"));
+/// The Transform effect's matrix in buffer pixels (`to_px` maps layer pixels into the buffer),
+/// as After Effects 2026 draws it (cases 723, 819, 820): `position + K · R · S · (p − anchor)`
+/// with the skew `K = rot(−axis) · shearY(tan skew) · rot(axis)` applied after the rotation.
+pub fn transform_matrix_px(pr: &crate::Params, to_px: impl Fn([f64; 2]) -> (f64, f64)) -> Mat3 {
+    let anchor = to_px(pr.v2("anchor"));
+    let pos = to_px(pr.v2("position"));
     let sh = pr.f("scaleHeight");
     let sw = if pr.b("uniform") { sh } else { pr.f("scaleWidth") };
+    let axis = pr.f("skewAxis");
+    let k = pr.f("skew").clamp(-85.0, 85.0).to_radians().tan();
+    let k = if k.is_finite() { k } else { 0.0 };
+    let skew = Mat3::rotate_deg(-axis) * Mat3([[1.0, 0.0, 0.0], [k, 1.0, 0.0], [0.0, 0.0, 1.0]]) * Mat3::rotate_deg(axis);
     Mat3::translate(vec2(pos.0, pos.1))
+        * skew
         * Mat3::rotate_deg(pr.f("rotation"))
-        * Mat3::skew_deg(pr.f("skew"), pr.f("skewAxis"))
         * Mat3::scale(vec2(sw / 100.0, sh / 100.0))
         * Mat3::translate(vec2(-anchor.0, -anchor.1))
 }
 
+fn transform_matrix(pr: &crate::Params, b: &Buf) -> Mat3 {
+    transform_matrix_px(pr, |p| b.to_px(p))
+}
+
+/// The transparent margins (left, top, right, bottom) a `w` x `h` buffer needs so its warp by
+/// any of `ms` stays on it: After Effects draws Transform's result outside the layer's bounds
+/// (case 723). Each side grows by its own overshoot; the grown buffer is capped at 16 384 px a
+/// side and 16 Mpx in all (the margins shrink in proportion), so a layer moved far away costs
+/// a bounded allocation.
+pub fn transform_grow(ms: &[Mat3], w: u32, h: u32) -> [u32; 4] {
+    const SIDE: f64 = 16_384.0;
+    const AREA: f64 = 16_777_216.0;
+    let (wf, hf) = (w as f64, h as f64);
+    let mut m = [0.0f64; 4];
+    for mat in ms {
+        for (x, y) in [(0.0, 0.0), (wf, 0.0), (0.0, hf), (wf, hf)] {
+            let q = mat.apply(vec2(x, y));
+            if q.x.is_finite() && q.y.is_finite() {
+                m = [m[0].max(-q.x), m[1].max(-q.y), m[2].max(q.x - wf), m[3].max(q.y - hf)];
+            }
+        }
+    }
+    let m = m.map(|v| v.ceil().max(0.0));
+    let fit = |len: f64, a: f64, b: f64| -> f64 {
+        let room = (SIDE - len).max(0.0);
+        if a + b > room && a + b > 0.0 { room / (a + b) } else { 1.0 }
+    };
+    let kx = fit(wf, m[0], m[2]);
+    let ky = fit(hf, m[1], m[3]);
+    let area = |k: f64| (wf + (m[0] + m[2]) * kx * k) * (hf + (m[1] + m[3]) * ky * k);
+    let k = if area(1.0) > AREA && area(1.0) > wf * hf {
+        // Shrink both margins by the same factor until the area fits.
+        let (mut lo, mut hi) = (0.0f64, 1.0f64);
+        for _ in 0..40 {
+            let mid = (lo + hi) / 2.0;
+            if area(mid) > AREA { hi = mid } else { lo = mid }
+        }
+        lo
+    } else {
+        1.0
+    };
+    [m[0] * kx * k, m[1] * ky * k, m[2] * kx * k, m[3] * ky * k].map(|v| v.floor().clamp(0.0, SIDE) as u32)
+}
+
 fn transform(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let anchor = b.to_px(ctx.params.v2("anchor"));
-    let pos = b.to_px(ctx.params.v2("position"));
-    let uniform = ctx.params.b("uniform");
-    let sh = ctx.params.f("scaleHeight");
-    let sw = if uniform { sh } else { ctx.params.f("scaleWidth") };
-    let skew = ctx.params.f("skew");
-    let skew_axis = ctx.params.f("skewAxis");
-    let rot = ctx.params.f("rotation");
     let opacity = ctx.params.f("opacity") as f32 / 100.0;
     let sampling = if ctx.params.e("sampling") == 1 { effectcraft_raster::Sampling::Bicubic } else { effectcraft_raster::Sampling::Bilinear };
     // Motion blur: the transform at Samples instants across the shutter, averaged (the
@@ -304,33 +347,35 @@ fn transform(ctx: &EffectCtx, mut b: Buf) -> Buf {
         && let Some(host) = ctx.env.host
     {
         let fd = 1.0 / ctx.fps();
-        let mut acc = Image::new(b.img.width, b.img.height);
-        let mut count = 0.0f32;
-        for k in 0..n {
-            let t = ctx.time + (phase + angle * k as f64 / (n - 1) as f64) / 360.0 * fd;
-            let Some(pr) = host.params_at(t) else { continue };
-            let mut one = Image::new(b.img.width, b.img.height);
-            let op = pr.f("opacity") as f32 / 100.0;
-            effectcraft_raster::composite_warp(
-                &mut one,
-                &b.img,
-                &transform_matrix(&pr, &b),
-                &effectcraft_raster::WarpOpts { opacity: op, sampling, ..Default::default() },
-            );
-            acc.data.iter_mut().zip(&one.data).for_each(|(a, o)| (0..4).for_each(|c| a[c] += o[c]));
-            count += 1.0;
-        }
-        if count > 0.0 {
+        let samples: Vec<crate::Params> = (0..n).filter_map(|k| host.params_at(ctx.time + (phase + angle * k as f64 / (n - 1) as f64) / 360.0 * fd)).collect();
+        if !samples.is_empty() {
+            if !ctx.adjustment {
+                let ms: Vec<Mat3> = samples.iter().map(|pr| transform_matrix(pr, &b)).collect();
+                b.pad_sides(transform_grow(&ms, b.img.width, b.img.height));
+            }
+            let mut acc = Image::new(b.img.width, b.img.height);
+            for pr in &samples {
+                let mut one = Image::new(b.img.width, b.img.height);
+                let op = pr.f("opacity") as f32 / 100.0;
+                effectcraft_raster::composite_warp(
+                    &mut one,
+                    &b.img,
+                    &transform_matrix(pr, &b),
+                    &effectcraft_raster::WarpOpts { opacity: op, sampling, ..Default::default() },
+                );
+                acc.data.iter_mut().zip(&one.data).for_each(|(a, o)| (0..4).for_each(|c| a[c] += o[c]));
+            }
+            let count = samples.len() as f32;
             acc.data.iter_mut().for_each(|p| p.iter_mut().for_each(|v| *v /= count));
             b.img = acc;
             return b;
         }
     }
-    let m = Mat3::translate(vec2(pos.0, pos.1))
-        * Mat3::rotate_deg(rot)
-        * Mat3::skew_deg(skew, skew_axis)
-        * Mat3::scale(vec2(sw / 100.0, sh / 100.0))
-        * Mat3::translate(vec2(-anchor.0, -anchor.1));
+    if !ctx.adjustment {
+        let m = transform_matrix(ctx.params, &b);
+        b.pad_sides(transform_grow(&[m], b.img.width, b.img.height));
+    }
+    let m = transform_matrix(ctx.params, &b);
     let mut out = Image::new(b.img.width, b.img.height);
     effectcraft_raster::composite_warp(&mut out, &b.img, &m, &effectcraft_raster::WarpOpts { opacity, sampling, ..Default::default() });
     b.img = out;
@@ -576,6 +621,144 @@ mod tests {
         }
     }
 
+    /// After Effects 2026 (cases 723, 819, 820): a grey 960 × 540 solid centred in a 1920 × 1080
+    /// comp with Transform. The skew applies after the rotation, and the result is drawn outside
+    /// the layer's bounds. Points are comp pixels sampled from AE's renders (at least 3 px from
+    /// an edge; true = the solid covers it), half where the old order and clipping differed.
+    #[test]
+    fn transform_matches_after_effects() {
+        let solid = Image::filled(960, 540, [0.5, 0.5, 0.5, 1.0]);
+        let p2 = |x: f64, y: f64| Value::Vec2([x, y]);
+        let cases: [(&str, Vec<(&str, Value)>, &[(u32, u32, bool)]); 3] = [
+            (
+                "723",
+                vec![
+                    ("anchor", p2(400.0, 200.0)),
+                    ("position", p2(500.0, 300.0)),
+                    ("uniform", Value::Bool(false)),
+                    ("scaleHeight", num(80.0)),
+                    ("scaleWidth", num(120.0)),
+                    ("skew", num(10.0)),
+                    ("skewAxis", num(20.0)),
+                    ("rotation", num(30.0)),
+                ],
+                &[
+                    (1465, 954, true),
+                    (1127, 821, true),
+                    (1378, 846, true),
+                    (1416, 878, true),
+                    (1486, 850, true),
+                    (492, 467, true),
+                    (706, 239, true),
+                    (1402, 1021, true),
+                    (518, 440, true),
+                    (1218, 882, true),
+                    (454, 448, true),
+                    (1473, 920, true),
+                    (1048, 654, true),
+                    (1050, 486, true),
+                    (1060, 736, true),
+                    (932, 804, true),
+                    (1074, 562, true),
+                    (653, 591, true),
+                    (1353, 466, false),
+                    (88, 1021, false),
+                    (1855, 886, false),
+                    (1796, 401, false),
+                    (497, 913, false),
+                    (1445, 515, false),
+                ],
+            ),
+            (
+                "819",
+                vec![("skew", num(15.0)), ("skewAxis", num(60.0))],
+                &[
+                    (465, 367, true),
+                    (554, 793, false),
+                    (481, 529, true),
+                    (1451, 599, true),
+                    (428, 575, true),
+                    (432, 600, true),
+                    (463, 444, true),
+                    (759, 803, false),
+                    (445, 684, true),
+                    (1411, 757, true),
+                    (915, 784, false),
+                    (480, 737, true),
+                    (758, 620, true),
+                    (975, 705, true),
+                    (1289, 376, true),
+                    (575, 420, true),
+                    (1015, 507, true),
+                    (1377, 448, true),
+                    (1679, 171, false),
+                    (194, 435, false),
+                    (413, 159, false),
+                    (327, 741, false),
+                    (1824, 138, false),
+                    (1093, 29, false),
+                ],
+            ),
+            (
+                "820",
+                vec![
+                    ("skew", num(15.0)),
+                    ("skewAxis", num(60.0)),
+                    ("rotation", num(-25.0)),
+                    ("uniform", Value::Bool(false)),
+                    ("scaleWidth", num(130.0)),
+                    ("scaleHeight", num(70.0)),
+                    ("anchor", p2(100.0, 50.0)),
+                ],
+                &[
+                    (1674, 566, true),
+                    (1425, 317, false),
+                    (1788, 278, true),
+                    (1530, 390, true),
+                    (1531, 652, true),
+                    (1589, 545, true),
+                    (1890, 441, true),
+                    (1724, 400, true),
+                    (1657, 511, true),
+                    (1895, 261, true),
+                    (1697, 344, true),
+                    (933, 840, true),
+                    (1413, 467, true),
+                    (1295, 691, true),
+                    (1353, 548, true),
+                    (1293, 548, true),
+                    (1103, 551, true),
+                    (973, 758, true),
+                    (446, 484, false),
+                    (1009, 420, false),
+                    (144, 761, false),
+                    (1812, 111, false),
+                    (1241, 10, false),
+                    (900, 854, false),
+                ],
+            ),
+        ];
+        for (case, set, pts) in cases {
+            let o = run("ec.distort.transform", &set, solid.clone());
+            for &(x, y, inside) in pts {
+                // Comp pixel → layer pixel (the solid's top-left sits at 480, 270) → buffer.
+                let (bx, by) = o.to_px([x as f64 + 0.5 - 480.0, y as f64 + 0.5 - 270.0]);
+                let a = if bx >= 0.0 && by >= 0.0 && bx < o.img.width as f64 && by < o.img.height as f64 { o.img.get(bx as i64, by as i64)[3] } else { 0.0 };
+                assert_eq!(a > 0.5, inside, "case {case}: comp pixel ({x}, {y}) alpha {a}");
+            }
+        }
+        // A huge scale stays within the buffer cap.
+        let o = run("ec.distort.transform", &[("scaleHeight", num(100_000.0))], Image::filled(8, 8, [1.0; 4]));
+        assert!(o.img.width <= 16_384 && o.img.height <= 16_384);
+        // A layer moved far right grows the buffer on that side only, within 16 Mpx.
+        let o = run("ec.distort.transform", &[("position", p2(960.0 + 2000.0, 540.0))], Image::filled(1920, 1080, [1.0; 4]));
+        assert_eq!((o.offset[0], o.img.height), (0.0, 1080), "only the right side grows");
+        assert!(o.img.width >= 1920 + 2000 && o.img.width as u64 * o.img.height as u64 <= 16_777_216, "{} x {}", o.img.width, o.img.height);
+        assert!(o.img.get(2000 + 960, 540)[3] > 0.99 && o.img.get(10, 540)[3] < 0.01);
+        let o = run("ec.distort.transform", &[("position", p2(40_000.0, 30_000.0))], Image::filled(1920, 1080, [1.0; 4]));
+        assert!(o.img.width as u64 * o.img.height as u64 <= 16_777_216, "{} x {}", o.img.width, o.img.height);
+    }
+
     #[test]
     fn transform_sampling_bicubic_differs_from_bilinear() {
         let im = img(32, 32);
diff --git a/crates/effects/src/distort3.rs b/crates/effects/src/distort3.rs
index cb389d901..a02ab5743 100644
--- a/crates/effects/src/distort3.rs
+++ b/crates/effects/src/distort3.rs
@@ -1084,337 +1084,4 @@ pub fn specs() -> Vec<EffectSpec> {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::{EffectEnv, MaskShape, Params};
-
-    fn img(w: u32, h: u32) -> Image {
-        crate::util::gen_image(w, h, |x, y| [x as f32 / w as f32, y as f32 / h as f32, ((x * 7 + y * 3) % 11) as f32 / 11.0, 1.0])
-    }
-
-    /// Run with Point defaults scaled to the layer (like `instantiate`).
-    fn run(id: &str, set: &[(&str, Value)], im: Image, masks: &[MaskShape]) -> Buf {
-        let s = crate::find(id).unwrap();
-        let ls = [im.width as f64, im.height as f64];
-        let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-        for ps in &s.params {
-            if let (ParamUi::Point, Value::Vec2(v)) = (&ps.ui, &ps.default) {
-                params.values.insert(ps.id.to_string(), Value::Vec2([v[0] * ls[0], v[1] * ls[1]]));
-            }
-        }
-        for (k, v) in set {
-            assert!(params.values.contains_key(*k), "{id}: {k}");
-            params.values.insert(k.to_string(), v.clone());
-        }
-        let env = EffectEnv { masks, ..Default::default() };
-        let ctx = EffectCtx { params: &params, time: 0.5, layer_size: ls, seed: 1, adjustment: false, env };
-        crate::apply(s, &ctx, Buf { img: im, offset: [0.0, 0.0], scale: 1.0 })
-    }
-
-    fn maxd(a: &Image, b: &Image) -> f32 {
-        assert_eq!((a.width, a.height), (b.width, b.height));
-        a.data.iter().zip(&b.data).map(|(p, q)| (0..4).map(|i| (p[i] - q[i]).abs()).fold(0.0, f32::max)).fold(0.0, f32::max)
-    }
-
-    fn rect_mask(x0: f64, y0: f64, x1: f64, y1: f64) -> MaskShape {
-        MaskShape { name: "m".into(), points: vec![[x0, y0], [x1, y0], [x1, y1], [x0, y1]], closed: true, inverted: false }
-    }
-
-    #[test]
-    fn identity_at_neutral_settings() {
-        let im = img(40, 30);
-        let cases: &[(&str, Vec<(&str, Value)>)] = &[
-            ("ec.distort.ccbender", vec![]),
-            ("ec.distort.ccpowerpin", vec![]),
-            ("ec.distort.ccripplepulse", vec![]),
-            ("ec.distort.ccslant", vec![]),
-            ("ec.distort.ccsmear", vec![("reach", num(0.0))]),
-            ("ec.distort.ccsplit", vec![("split", num(0.0))]),
-            ("ec.distort.ccsplit2", vec![("split1", num(0.0)), ("split2", num(0.0))]),
-            ("ec.distort.smear", vec![]),
-            ("ec.distort.reshape", vec![]),
-            ("ec.distort.twirllegacy", vec![]),
-            ("ec.distort.warp", vec![("warpStyle", Value::Enum(5))]),
-            ("ec.distort.upscale", vec![]),
-        ];
-        for (id, set) in cases {
-            let o = run(id, set, im.clone(), &[]);
-            assert!(maxd(&o.img, &im) < 1e-5, "{id} not identity");
-            assert_eq!(o.offset, [0.0, 0.0], "{id}");
-        }
-        // Power pin with perspective 0 at default corners is also identity.
-        let o = run("ec.distort.ccpowerpin", &[("perspective", num(0.0))], im.clone(), &[]);
-        assert!(maxd(&o.img, &im) < 1e-4);
-    }
-
-    #[test]
-    fn all_deterministic() {
-        let im = img(36, 28);
-        let masks = [rect_mask(8.0, 8.0, 16.0, 16.0), rect_mask(12.0, 10.0, 22.0, 20.0), rect_mask(2.0, 2.0, 34.0, 26.0)];
-        let cases: &[(&str, Vec<(&str, Value)>)] = &[
-            ("ec.distort.ccbender", vec![("amount", num(40.0)), ("style", Value::Enum(3))]),
-            ("ec.distort.ccblobbylize", vec![]),
-            ("ec.distort.ccpowerpin", vec![("topLeft", pt(5.0, 3.0)), ("perspective", num(40.0))]),
-            ("ec.distort.ccripplepulse", vec![("pulseLevel", num(80.0))]),
-            ("ec.distort.ccslant", vec![("slant", num(30.0)), ("stretching", Value::Bool(true))]),
-            ("ec.distort.ccsmear", vec![]),
-            ("ec.distort.ccsplit", vec![]),
-            ("ec.distort.ccsplit2", vec![("split2", num(10.0))]),
-            ("ec.distort.smear", vec![("sourceMask", Value::Enum(1)), ("boundaryMask", Value::Enum(3)), ("maskOffset", pt(4.0, 2.0))]),
-            ("ec.distort.reshape", vec![("sourceMask", Value::Enum(1)), ("destinationMask", Value::Enum(2)), ("boundaryMask", Value::Enum(3))]),
-            ("ec.distort.twirllegacy", vec![("angle", num(90.0))]),
-            ("ec.distort.warp", vec![("bend", num(50.0)), ("horizontalDistortion", num(20.0))]),
-            ("ec.distort.upscale", vec![("scale", num(200.0))]),
-        ];
-        for (id, set) in cases {
-            let a = run(id, set, im.clone(), &masks);
-            let b = run(id, set, im.clone(), &masks);
-            assert_eq!(a.img, b.img, "{id}");
-            assert!(a.img.data.iter().all(|p| p.iter().all(|v| v.is_finite())), "{id}");
-            assert!(a.img.width != im.width || a.img.height != im.height || maxd(&a.img, &im) > 1e-3, "{id} did nothing");
-        }
-    }
-
-    #[test]
-    fn blobbylize_defaults_match_ae() {
-        let s = crate::find("ec.distort.ccblobbylize").unwrap();
-        let default = |id: &str| s.params.iter().find(|p| p.id == id).unwrap().default.clone();
-        assert_eq!(default("property"), Value::Enum(0), "Property defaults to Red");
-        assert_eq!(default("softness"), num(20.0));
-        assert_eq!(default("cutAway"), num(25.0));
-        assert_eq!(default("lightHeight"), num(65.0));
-        assert_eq!(default("lightPosition"), pt(0.5, 0.5));
-        assert_eq!(default("ambient"), num(75.0));
-        assert_eq!(default("diffuse"), num(25.0));
-        assert_eq!(default("specular"), num(100.0));
-        assert_eq!(default("roughness"), num(0.025));
-        assert_eq!(default("metal"), num(100.0));
-    }
-
-    #[test]
-    fn blobbylize_cut_away_thresholds_a_height_ramp() {
-        // AE oracle: Cut Away is a linear height threshold with a ~1 px antialiased edge.
-        let im = crate::util::gen_image(1920, 8, |x, _| {
-            let h = x as f32 / 1920.0;
-            [h, h, h, 1.0]
-        });
-        let o = run("ec.distort.ccblobbylize", &[("property", Value::Enum(0)), ("softness", num(0.0)), ("cutAway", num(25.0))], im, &[]);
-        assert_eq!(o.img.get(400, 4)[3], 0.0, "below Cut Away must be transparent");
-        assert_eq!(o.img.get(560, 4)[3], 1.0, "above Cut Away must be opaque");
-        let edge = o.img.get(480, 4)[3];
-        assert!((0.45..=0.55).contains(&edge), "edge alpha {edge} is not a one-pixel threshold");
-        let partial = (450..510).filter(|&x| (0.001..0.999).contains(&o.img.get(x, 4)[3])).count();
-        assert!(partial <= 2, "{partial} antialiased columns instead of one");
-    }
-
-    #[test]
-    fn blobbylize_cut_away_100_is_empty() {
-        // Regression: the old clamp to 0.99 left the top of the ramp opaque at Cut Away 100.
-        let im = crate::util::gen_image(1920, 8, |x, _| {
-            let h = x as f32 / 1920.0;
-            [h, h, h, 1.0]
-        });
-        let o = run("ec.distort.ccblobbylize", &[("property", Value::Enum(0)), ("softness", num(0.0)), ("cutAway", num(100.0))], im, &[]);
-        assert!(o.img.data.iter().all(|p| p[3] == 0.0), "Cut Away 100 left opaque pixels");
-    }
-
-    #[test]
-    fn blobbylize_cut_away_100_clears_an_opaque_edge() {
-        // An opaque source reaches h = 1 on the high side of an edge; the gradient antialias
-        // used to leave m = 0.5 there, so Cut Away 100 still produced visible pixels.
-        let im = crate::util::gen_image(64, 8, |x, _| if x < 32 { [1.0; 4] } else { [0.0; 4] });
-        let o = run("ec.distort.ccblobbylize", &[("property", Value::Enum(3)), ("softness", num(0.0)), ("cutAway", num(100.0))], im, &[]);
-        assert!(o.img.data.iter().all(|p| p[3] == 0.0), "Cut Away 100 left an opaque edge");
-    }
-
-    #[test]
-    fn blobbylize_softness_warps_a_step_matte_inward() {
-        // AE oracle T2: a self alpha step at x = 960, Softness 20, Cut Away 0 puts the matte
-        // edge at about x = 946, not at the source edge. The PR's matte-preserving version
-        // left it at 960; the effect must warp the source matte.
-        let im = crate::util::gen_image(1920, 32, |x, _| if x < 960 { [1.0; 4] } else { [0.0; 4] });
-        let o = run(
-            "ec.distort.ccblobbylize",
-            &[
-                ("property", Value::Enum(3)),
-                ("softness", num(20.0)),
-                ("cutAway", num(0.0)),
-                ("ambient", num(100.0)),
-                ("diffuse", num(0.0)),
-                ("specular", num(0.0)),
-                ("metal", num(0.0)),
-            ],
-            im,
-            &[],
-        );
-        assert!(o.img.get(945, 16)[3] > 0.95, "the matte did not move inward: {}", o.img.get(945, 16)[3]);
-        assert!(o.img.get(949, 16)[3] < 0.05, "source alpha leaked past the warped edge");
-        assert_eq!(o.img.get(960, 16)[3], 0.0, "the source matte was preserved instead of warped");
-    }
-
-    /// A text layer's buffer: 20 × 10 opaque pixels at (90, 45)–(110, 55) of its comp-sized
-    /// (200 × 100) layer bounds, after `id` with `set`.
-    fn on_text(id: &str, set: &[(&str, Value)]) -> Buf {
-        let s = crate::find(id).unwrap();
-        let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-        for (k, v) in set {
-            assert!(params.values.contains_key(*k), "{id}: {k}");
-            params.values.insert(k.to_string(), v.clone());
-        }
-        let mut im = Image::new(20, 10);
-        im.data.iter_mut().for_each(|p| *p = [1.0; 4]);
-        let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [200.0, 100.0], seed: 1, adjustment: false, env: Default::default() };
-        crate::apply(s, &ctx, Buf { img: im, offset: [-90.0, -45.0], scale: 1.0 })
-    }
-
-    /// Alpha at layer point `p` (0 outside the buffer).
-    fn alpha_at(b: &Buf, p: [f64; 2]) -> f32 {
-        let (x, y) = b.to_px(p);
-        b.img.get(x.floor() as i64, y.floor() as i64)[3]
-    }
-
-    /// #659: CC Smear and CC Tiler on a text layer reach past the text's box to the layer bounds
-    /// (comp-sized, as in After Effects), not cut off where the glyphs end.
-    #[test]
-    fn effects_on_text_reach_past_its_box() {
-        let smear = on_text("ec.distort.ccsmear", &[("from", pt(100.0, 50.0)), ("to", pt(140.0, 50.0)), ("reach", num(100.0)), ("radius", num(30.0))]);
-        assert!(alpha_at(&smear, [130.0, 50.0]) > 0.9, "the smear is cut off at the text's box");
-        assert!(smear.img.width < 200, "it grows only as far as pixels move");
-        let tiles = on_text("ec.distort.cctiler", &[("scale", num(50.0)), ("center", pt(100.0, 50.0))]);
-        assert!(alpha_at(&tiles, [100.0, 50.0]) > 0.9);
-        assert!(alpha_at(&tiles, [2.0, 50.0]) > 0.9, "tiles fill the layer bounds");
-        assert!(alpha_at(&tiles, [50.0, 50.0]) < 0.1);
-        // A footage layer's buffer is its bounds already: no change.
-        let o = run("ec.distort.ccsmear", &[], img(40, 30), &[]);
-        assert_eq!((o.img.width, o.img.height, o.offset), (40, 30, [0.0, 0.0]));
-    }
-
-    #[test]
-    fn every_warp_style_runs_and_bends() {
-        let im = img(40, 30);
-        for s in 0..WARP_STYLES.len() as u32 {
-            for axis in 0..2 {
-                let o = run("ec.distort.warp", &[("warpStyle", Value::Enum(s)), ("warpAxis", Value::Enum(axis)), ("bend", num(50.0))], im.clone(), &[]);
-                let pad = o.offset[0] as u32;
-                // The layer centre's neighbourhood is still made of source pixels.
-                assert!(o.img.get(pad as i64 + 20, pad as i64 + 15)[3] > 0.5, "style {s}");
-                assert!(o.img.width > im.width);
-            }
-        }
-        // Arc with positive bend raises the middle of the layer: the top edge in the middle
-        // moves up (opaque pixels above the original top).
-        let o = run("ec.distort.warp", &[("warpStyle", Value::Enum(3)), ("bend", num(50.0))], im.clone(), &[]);
-        let pad = o.offset[1] as i64;
-        assert!(o.img.get(o.offset[0] as i64 + 20, pad - 3)[3] > 0.5);
-        assert!(o.img.get(o.offset[0] as i64 + 1, pad - 3)[3] < 0.5);
-    }
-
-    #[test]
-    fn power_pin_moves_corners() {
-        let im = img(20, 20);
-        // Pin to the right half: output x in 10..20 shows the whole layer squeezed.
-        let set = [("topLeft", pt(10.0, 0.0)), ("bottomLeft", pt(10.0, 20.0))];
-        let o = run("ec.distort.ccpowerpin", &set, im.clone(), &[]);
-        assert_eq!(o.img.get(3, 10)[3], 0.0);
-        let px = o.img.get(15, 10);
-        assert!((px[0] - 0.5).abs() < 0.1, "{px:?}");
-    }
-
-    #[test]
-    fn power_pin_unstretch_expands_pinned_region() {
-        let im = crate::util::gen_image(24, 16, |_, _| [1.0, 0.0, 0.0, 1.0]);
-        let inset = [("topLeft", pt(6.0, 4.0)), ("topRight", pt(18.0, 4.0)), ("bottomRight", pt(18.0, 12.0)), ("bottomLeft", pt(6.0, 12.0))];
-        let opaque = |o: &Buf| o.img.data.iter().filter(|p| p[3] > 0.99).count();
-        let off = run("ec.distort.ccpowerpin", &inset, im.clone(), &[]);
-        assert_eq!(opaque(&off), 96);
-        let mut set = inset.to_vec();
-        set.push(("unstretch", Value::Bool(true)));
-        let on = run("ec.distort.ccpowerpin", &set, im.clone(), &[]);
-        assert_eq!(opaque(&on), 24 * 16);
-        assert!(on.img.get(0, 0)[3] > 0.99);
-        // Default corners are the identity either way.
-        let id = run("ec.distort.ccpowerpin", &[("unstretch", Value::Bool(true))], im.clone(), &[]);
-        assert!(maxd(&id.img, &im) < 1e-4);
-    }
-
-    #[test]
-    fn split_opens_a_gap() {
-        let im = img(40, 30);
-        let o = run("ec.distort.ccsplit", &[("split", num(40.0))], im.clone(), &[]);
-        assert_eq!(o.img.get(20, 15)[3], 0.0);
-        assert_eq!(o.img.get(2, 2), im.get(2, 2));
-    }
-
-    #[test]
-    fn slant_shears_from_floor() {
-        let im = img(20, 20);
-        let o = run("ec.distort.ccslant", &[("slant", num(50.0))], im.clone(), &[]);
-        let pad = o.offset[0] as i64;
-        // Bottom row stays put; the top row shifts right by ~10 px.
-        assert!((o.img.get(pad + 5, pad + 19)[0] - im.get(5, 19)[0]).abs() < 0.05);
-        assert!((o.img.get(pad + 15, pad)[0] - im.get(5, 0)[0]).abs() < 0.08);
-    }
-
-    #[test]
-    fn reshape_moves_source_to_destination() {
-        // A bright square at the source mask; reshape to a shifted destination mask.
-        let im = crate::util::gen_image(40, 40, |x, y| if (10..20).contains(&x) && (10..20).contains(&y) { [1.0; 4] } else { [0.0, 0.0, 0.0, 1.0] });
-        let masks = [rect_mask(10.0, 10.0, 20.0, 20.0), rect_mask(16.0, 10.0, 26.0, 20.0), rect_mask(0.0, 0.0, 40.0, 40.0)];
-        let o = run("ec.distort.reshape", &[("sourceMask", Value::Enum(1)), ("destinationMask", Value::Enum(2)), ("boundaryMask", Value::Enum(3))], im, &masks);
-        assert!(o.img.get(24, 15)[0] > 0.8, "{:?}", o.img.get(24, 15));
-        assert!(o.img.get(11, 15)[0] < 0.3, "{:?}", o.img.get(11, 15));
-    }
-
-    #[test]
-    fn reshape_correspondence_points_steer_the_match() {
-        // Matching outlines with a zero pair change nothing; a quarter-turn offset twists.
-        let im = img(40, 40);
-        let masks = [rect_mask(10.0, 10.0, 30.0, 30.0), rect_mask(10.0, 10.0, 30.0, 30.0), rect_mask(0.0, 0.0, 40.0, 40.0)];
-        let base = [("sourceMask", Value::Enum(1)), ("destinationMask", Value::Enum(2)), ("boundaryMask", Value::Enum(3))];
-        let same = run("ec.distort.reshape", &[base.as_slice(), &[("correspondencePoints", Value::Str("0,0".into()))]].concat(), im.clone(), &masks);
-        assert!(maxd(&same.img, &im) < 1e-3, "matching outlines: no change");
-        let twisted = run("ec.distort.reshape", &[base.as_slice(), &[("correspondencePoints", Value::Str("0.25,0".into()))]].concat(), im.clone(), &masks);
-        assert!(maxd(&twisted.img, &im) > 0.1);
-        // Fraction mapping.
-        assert!((map_fraction(&[(0.0, 0.0), (0.5, 0.25)], 0.125, true) - 0.25).abs() < 1e-9);
-        assert!((map_fraction(&[(0.2, 0.0)], 0.9, true) - 0.1).abs() < 1e-9);
-        assert!((map_fraction(&[(0.5, 0.5)], 0.25, false) - 0.25).abs() < 1e-9);
-    }
-
-    #[test]
-    fn upscale_grows_about_centre() {
-        let im = img(20, 10);
-        let o = run("ec.distort.upscale", &[("scale", num(200.0)), ("detail", num(0.0))], im.clone(), &[]);
-        assert_eq!((o.img.width, o.img.height), (40, 20));
-        // Grown about the layer centre: layer point (0,0) now sits at buffer pixel (10,5), so the
-        // centre (10,5) lands in the middle of the 40×20 buffer.
-        assert_eq!(o.offset, [10.0, 5.0]);
-        let c = o.img.sample_bilinear(20.0, 10.0);
-        assert!((c[0] - im.sample_bilinear(10.0, 5.0)[0]).abs() < 0.03);
-    }
-
-    #[test]
-    fn twirl_legacy_rotates_inside_radius() {
-        let im = img(40, 40);
-        let o = run("ec.distort.twirllegacy", &[("angle", num(180.0)), ("radius", num(100.0))], im.clone(), &[]);
-        assert!(maxd(&o.img, &im) > 0.1);
-        // Corners lie outside the radius.
-        assert_eq!(o.img.get(0, 0), im.get(0, 0));
-    }
-
-    #[test]
-    fn half_resolution_matches_scaled_geometry() {
-        // Bender at scale 0.5: the buffer is half size, parameters in layer pixels.
-        let s = crate::find("ec.distort.ccbender").unwrap();
-        let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-        params.values.insert("amount".into(), num(30.0));
-        params.values.insert("top".into(), pt(20.0, 0.0));
-        params.values.insert("base".into(), pt(20.0, 40.0));
-        let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [40.0, 40.0], seed: 1, adjustment: false, env: Default::default() };
-        let full = crate::apply(s, &ctx, Buf { img: img(40, 40), offset: [0.0; 2], scale: 1.0 });
-        let half = crate::apply(s, &ctx, Buf { img: effectcraft_raster::resample(&img(40, 40), 20, 20), offset: [0.0; 2], scale: 0.5 });
-        let a = full.img.sample_bilinear(20.0, 4.0)[3];
-        let b = half.img.sample_bilinear(10.0, 2.0)[3];
-        assert!((a - b).abs() < 0.3);
-    }
-}
+mod tests;
diff --git a/crates/effects/src/distort3/tests.rs b/crates/effects/src/distort3/tests.rs
new file mode 100644
index 000000000..b50d6b450
--- /dev/null
+++ b/crates/effects/src/distort3/tests.rs
@@ -0,0 +1,332 @@
+use super::*;
+use crate::{EffectEnv, MaskShape, Params};
+
+fn img(w: u32, h: u32) -> Image {
+    crate::util::gen_image(w, h, |x, y| [x as f32 / w as f32, y as f32 / h as f32, ((x * 7 + y * 3) % 11) as f32 / 11.0, 1.0])
+}
+
+/// Run with Point defaults scaled to the layer (like `instantiate`).
+fn run(id: &str, set: &[(&str, Value)], im: Image, masks: &[MaskShape]) -> Buf {
+    let s = crate::find(id).unwrap();
+    let ls = [im.width as f64, im.height as f64];
+    let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+    for ps in &s.params {
+        if let (ParamUi::Point, Value::Vec2(v)) = (&ps.ui, &ps.default) {
+            params.values.insert(ps.id.to_string(), Value::Vec2([v[0] * ls[0], v[1] * ls[1]]));
+        }
+    }
+    for (k, v) in set {
+        assert!(params.values.contains_key(*k), "{id}: {k}");
+        params.values.insert(k.to_string(), v.clone());
+    }
+    let env = EffectEnv { masks, ..Default::default() };
+    let ctx = EffectCtx { params: &params, time: 0.5, layer_size: ls, seed: 1, adjustment: false, env };
+    crate::apply(s, &ctx, Buf { img: im, offset: [0.0, 0.0], scale: 1.0 })
+}
+
+fn maxd(a: &Image, b: &Image) -> f32 {
+    assert_eq!((a.width, a.height), (b.width, b.height));
+    a.data.iter().zip(&b.data).map(|(p, q)| (0..4).map(|i| (p[i] - q[i]).abs()).fold(0.0, f32::max)).fold(0.0, f32::max)
+}
+
+fn rect_mask(x0: f64, y0: f64, x1: f64, y1: f64) -> MaskShape {
+    MaskShape { name: "m".into(), points: vec![[x0, y0], [x1, y0], [x1, y1], [x0, y1]], closed: true, inverted: false }
+}
+
+#[test]
+fn identity_at_neutral_settings() {
+    let im = img(40, 30);
+    let cases: &[(&str, Vec<(&str, Value)>)] = &[
+        ("ec.distort.ccbender", vec![]),
+        ("ec.distort.ccpowerpin", vec![]),
+        ("ec.distort.ccripplepulse", vec![]),
+        ("ec.distort.ccslant", vec![]),
+        ("ec.distort.ccsmear", vec![("reach", num(0.0))]),
+        ("ec.distort.ccsplit", vec![("split", num(0.0))]),
+        ("ec.distort.ccsplit2", vec![("split1", num(0.0)), ("split2", num(0.0))]),
+        ("ec.distort.smear", vec![]),
+        ("ec.distort.reshape", vec![]),
+        ("ec.distort.twirllegacy", vec![]),
+        ("ec.distort.warp", vec![("warpStyle", Value::Enum(5))]),
+        ("ec.distort.upscale", vec![]),
+    ];
+    for (id, set) in cases {
+        let o = run(id, set, im.clone(), &[]);
+        assert!(maxd(&o.img, &im) < 1e-5, "{id} not identity");
+        assert_eq!(o.offset, [0.0, 0.0], "{id}");
+    }
+    // Power pin with perspective 0 at default corners is also identity.
+    let o = run("ec.distort.ccpowerpin", &[("perspective", num(0.0))], im.clone(), &[]);
+    assert!(maxd(&o.img, &im) < 1e-4);
+}
+
+#[test]
+fn all_deterministic() {
+    let im = img(36, 28);
+    let masks = [rect_mask(8.0, 8.0, 16.0, 16.0), rect_mask(12.0, 10.0, 22.0, 20.0), rect_mask(2.0, 2.0, 34.0, 26.0)];
+    let cases: &[(&str, Vec<(&str, Value)>)] = &[
+        ("ec.distort.ccbender", vec![("amount", num(40.0)), ("style", Value::Enum(3))]),
+        ("ec.distort.ccblobbylize", vec![]),
+        ("ec.distort.ccpowerpin", vec![("topLeft", pt(5.0, 3.0)), ("perspective", num(40.0))]),
+        ("ec.distort.ccripplepulse", vec![("pulseLevel", num(80.0))]),
+        ("ec.distort.ccslant", vec![("slant", num(30.0)), ("stretching", Value::Bool(true))]),
+        ("ec.distort.ccsmear", vec![]),
+        ("ec.distort.ccsplit", vec![]),
+        ("ec.distort.ccsplit2", vec![("split2", num(10.0))]),
+        ("ec.distort.smear", vec![("sourceMask", Value::Enum(1)), ("boundaryMask", Value::Enum(3)), ("maskOffset", pt(4.0, 2.0))]),
+        ("ec.distort.reshape", vec![("sourceMask", Value::Enum(1)), ("destinationMask", Value::Enum(2)), ("boundaryMask", Value::Enum(3))]),
+        ("ec.distort.twirllegacy", vec![("angle", num(90.0))]),
+        ("ec.distort.warp", vec![("bend", num(50.0)), ("horizontalDistortion", num(20.0))]),
+        ("ec.distort.upscale", vec![("scale", num(200.0))]),
+    ];
+    for (id, set) in cases {
+        let a = run(id, set, im.clone(), &masks);
+        let b = run(id, set, im.clone(), &masks);
+        assert_eq!(a.img, b.img, "{id}");
+        assert!(a.img.data.iter().all(|p| p.iter().all(|v| v.is_finite())), "{id}");
+        assert!(a.img.width != im.width || a.img.height != im.height || maxd(&a.img, &im) > 1e-3, "{id} did nothing");
+    }
+}
+
+#[test]
+fn blobbylize_defaults_match_ae() {
+    let s = crate::find("ec.distort.ccblobbylize").unwrap();
+    let default = |id: &str| s.params.iter().find(|p| p.id == id).unwrap().default.clone();
+    assert_eq!(default("property"), Value::Enum(0), "Property defaults to Red");
+    assert_eq!(default("softness"), num(20.0));
+    assert_eq!(default("cutAway"), num(25.0));
+    assert_eq!(default("lightHeight"), num(65.0));
+    assert_eq!(default("lightPosition"), pt(0.5, 0.5));
+    assert_eq!(default("ambient"), num(75.0));
+    assert_eq!(default("diffuse"), num(25.0));
+    assert_eq!(default("specular"), num(100.0));
+    assert_eq!(default("roughness"), num(0.025));
+    assert_eq!(default("metal"), num(100.0));
+}
+
+#[test]
+fn blobbylize_cut_away_thresholds_a_height_ramp() {
+    // AE oracle: Cut Away is a linear height threshold with a ~1 px antialiased edge.
+    let im = crate::util::gen_image(1920, 8, |x, _| {
+        let h = x as f32 / 1920.0;
+        [h, h, h, 1.0]
+    });
+    let o = run("ec.distort.ccblobbylize", &[("property", Value::Enum(0)), ("softness", num(0.0)), ("cutAway", num(25.0))], im, &[]);
+    assert_eq!(o.img.get(400, 4)[3], 0.0, "below Cut Away must be transparent");
+    assert_eq!(o.img.get(560, 4)[3], 1.0, "above Cut Away must be opaque");
+    let edge = o.img.get(480, 4)[3];
+    assert!((0.45..=0.55).contains(&edge), "edge alpha {edge} is not a one-pixel threshold");
+    let partial = (450..510).filter(|&x| (0.001..0.999).contains(&o.img.get(x, 4)[3])).count();
+    assert!(partial <= 2, "{partial} antialiased columns instead of one");
+}
+
+#[test]
+fn blobbylize_cut_away_100_is_empty() {
+    // Regression: the old clamp to 0.99 left the top of the ramp opaque at Cut Away 100.
+    let im = crate::util::gen_image(1920, 8, |x, _| {
+        let h = x as f32 / 1920.0;
+        [h, h, h, 1.0]
+    });
+    let o = run("ec.distort.ccblobbylize", &[("property", Value::Enum(0)), ("softness", num(0.0)), ("cutAway", num(100.0))], im, &[]);
+    assert!(o.img.data.iter().all(|p| p[3] == 0.0), "Cut Away 100 left opaque pixels");
+}
+
+#[test]
+fn blobbylize_cut_away_100_clears_an_opaque_edge() {
+    // An opaque source reaches h = 1 on the high side of an edge; the gradient antialias
+    // used to leave m = 0.5 there, so Cut Away 100 still produced visible pixels.
+    let im = crate::util::gen_image(64, 8, |x, _| if x < 32 { [1.0; 4] } else { [0.0; 4] });
+    let o = run("ec.distort.ccblobbylize", &[("property", Value::Enum(3)), ("softness", num(0.0)), ("cutAway", num(100.0))], im, &[]);
+    assert!(o.img.data.iter().all(|p| p[3] == 0.0), "Cut Away 100 left an opaque edge");
+}
+
+#[test]
+fn blobbylize_softness_warps_a_step_matte_inward() {
+    // AE oracle T2: a self alpha step at x = 960, Softness 20, Cut Away 0 puts the matte
+    // edge at about x = 946, not at the source edge. The PR's matte-preserving version
+    // left it at 960; the effect must warp the source matte.
+    let im = crate::util::gen_image(1920, 32, |x, _| if x < 960 { [1.0; 4] } else { [0.0; 4] });
+    let o = run(
+        "ec.distort.ccblobbylize",
+        &[
+            ("property", Value::Enum(3)),
+            ("softness", num(20.0)),
+            ("cutAway", num(0.0)),
+            ("ambient", num(100.0)),
+            ("diffuse", num(0.0)),
+            ("specular", num(0.0)),
+            ("metal", num(0.0)),
+        ],
+        im,
+        &[],
+    );
+    assert!(o.img.get(945, 16)[3] > 0.95, "the matte did not move inward: {}", o.img.get(945, 16)[3]);
+    assert!(o.img.get(949, 16)[3] < 0.05, "source alpha leaked past the warped edge");
+    assert_eq!(o.img.get(960, 16)[3], 0.0, "the source matte was preserved instead of warped");
+}
+
+/// A text layer's buffer: 20 × 10 opaque pixels at (90, 45)–(110, 55) of its comp-sized
+/// (200 × 100) layer bounds, after `id` with `set`.
+fn on_text(id: &str, set: &[(&str, Value)]) -> Buf {
+    let s = crate::find(id).unwrap();
+    let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+    for (k, v) in set {
+        assert!(params.values.contains_key(*k), "{id}: {k}");
+        params.values.insert(k.to_string(), v.clone());
+    }
+    let mut im = Image::new(20, 10);
+    im.data.iter_mut().for_each(|p| *p = [1.0; 4]);
+    let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [200.0, 100.0], seed: 1, adjustment: false, env: Default::default() };
+    crate::apply(s, &ctx, Buf { img: im, offset: [-90.0, -45.0], scale: 1.0 })
+}
+
+/// Alpha at layer point `p` (0 outside the buffer).
+fn alpha_at(b: &Buf, p: [f64; 2]) -> f32 {
+    let (x, y) = b.to_px(p);
+    b.img.get(x.floor() as i64, y.floor() as i64)[3]
+}
+
+/// #659: CC Smear and CC Tiler on a text layer reach past the text's box to the layer bounds
+/// (comp-sized, as in After Effects), not cut off where the glyphs end.
+#[test]
+fn effects_on_text_reach_past_its_box() {
+    let smear = on_text("ec.distort.ccsmear", &[("from", pt(100.0, 50.0)), ("to", pt(140.0, 50.0)), ("reach", num(100.0)), ("radius", num(30.0))]);
+    assert!(alpha_at(&smear, [130.0, 50.0]) > 0.9, "the smear is cut off at the text's box");
+    assert!(smear.img.width < 200, "it grows only as far as pixels move");
+    let tiles = on_text("ec.distort.cctiler", &[("scale", num(50.0)), ("center", pt(100.0, 50.0))]);
+    assert!(alpha_at(&tiles, [100.0, 50.0]) > 0.9);
+    assert!(alpha_at(&tiles, [2.0, 50.0]) > 0.9, "tiles fill the layer bounds");
+    assert!(alpha_at(&tiles, [50.0, 50.0]) < 0.1);
+    // A footage layer's buffer is its bounds already: no change.
+    let o = run("ec.distort.ccsmear", &[], img(40, 30), &[]);
+    assert_eq!((o.img.width, o.img.height, o.offset), (40, 30, [0.0, 0.0]));
+}
+
+#[test]
+fn every_warp_style_runs_and_bends() {
+    let im = img(40, 30);
+    for s in 0..WARP_STYLES.len() as u32 {
+        for axis in 0..2 {
+            let o = run("ec.distort.warp", &[("warpStyle", Value::Enum(s)), ("warpAxis", Value::Enum(axis)), ("bend", num(50.0))], im.clone(), &[]);
+            let pad = o.offset[0] as u32;
+            // The layer centre's neighbourhood is still made of source pixels.
+            assert!(o.img.get(pad as i64 + 20, pad as i64 + 15)[3] > 0.5, "style {s}");
+            assert!(o.img.width > im.width);
+        }
+    }
+    // Arc with positive bend raises the middle of the layer: the top edge in the middle
+    // moves up (opaque pixels above the original top).
+    let o = run("ec.distort.warp", &[("warpStyle", Value::Enum(3)), ("bend", num(50.0))], im.clone(), &[]);
+    let pad = o.offset[1] as i64;
+    assert!(o.img.get(o.offset[0] as i64 + 20, pad - 3)[3] > 0.5);
+    assert!(o.img.get(o.offset[0] as i64 + 1, pad - 3)[3] < 0.5);
+}
+
+#[test]
+fn power_pin_moves_corners() {
+    let im = img(20, 20);
+    // Pin to the right half: output x in 10..20 shows the whole layer squeezed.
+    let set = [("topLeft", pt(10.0, 0.0)), ("bottomLeft", pt(10.0, 20.0))];
+    let o = run("ec.distort.ccpowerpin", &set, im.clone(), &[]);
+    assert_eq!(o.img.get(3, 10)[3], 0.0);
+    let px = o.img.get(15, 10);
+    assert!((px[0] - 0.5).abs() < 0.1, "{px:?}");
+}
+
+#[test]
+fn power_pin_unstretch_expands_pinned_region() {
+    let im = crate::util::gen_image(24, 16, |_, _| [1.0, 0.0, 0.0, 1.0]);
+    let inset = [("topLeft", pt(6.0, 4.0)), ("topRight", pt(18.0, 4.0)), ("bottomRight", pt(18.0, 12.0)), ("bottomLeft", pt(6.0, 12.0))];
+    let opaque = |o: &Buf| o.img.data.iter().filter(|p| p[3] > 0.99).count();
+    let off = run("ec.distort.ccpowerpin", &inset, im.clone(), &[]);
+    assert_eq!(opaque(&off), 96);
+    let mut set = inset.to_vec();
+    set.push(("unstretch", Value::Bool(true)));
+    let on = run("ec.distort.ccpowerpin", &set, im.clone(), &[]);
+    assert_eq!(opaque(&on), 24 * 16);
+    assert!(on.img.get(0, 0)[3] > 0.99);
+    // Default corners are the identity either way.
+    let id = run("ec.distort.ccpowerpin", &[("unstretch", Value::Bool(true))], im.clone(), &[]);
+    assert!(maxd(&id.img, &im) < 1e-4);
+}
+
+#[test]
+fn split_opens_a_gap() {
+    let im = img(40, 30);
+    let o = run("ec.distort.ccsplit", &[("split", num(40.0))], im.clone(), &[]);
+    assert_eq!(o.img.get(20, 15)[3], 0.0);
+    assert_eq!(o.img.get(2, 2), im.get(2, 2));
+}
+
+#[test]
+fn slant_shears_from_floor() {
+    let im = img(20, 20);
+    let o = run("ec.distort.ccslant", &[("slant", num(50.0))], im.clone(), &[]);
+    let pad = o.offset[0] as i64;
+    // Bottom row stays put; the top row shifts right by ~10 px.
+    assert!((o.img.get(pad + 5, pad + 19)[0] - im.get(5, 19)[0]).abs() < 0.05);
+    assert!((o.img.get(pad + 15, pad)[0] - im.get(5, 0)[0]).abs() < 0.08);
+}
+
+#[test]
+fn reshape_moves_source_to_destination() {
+    // A bright square at the source mask; reshape to a shifted destination mask.
+    let im = crate::util::gen_image(40, 40, |x, y| if (10..20).contains(&x) && (10..20).contains(&y) { [1.0; 4] } else { [0.0, 0.0, 0.0, 1.0] });
+    let masks = [rect_mask(10.0, 10.0, 20.0, 20.0), rect_mask(16.0, 10.0, 26.0, 20.0), rect_mask(0.0, 0.0, 40.0, 40.0)];
+    let o = run("ec.distort.reshape", &[("sourceMask", Value::Enum(1)), ("destinationMask", Value::Enum(2)), ("boundaryMask", Value::Enum(3))], im, &masks);
+    assert!(o.img.get(24, 15)[0] > 0.8, "{:?}", o.img.get(24, 15));
+    assert!(o.img.get(11, 15)[0] < 0.3, "{:?}", o.img.get(11, 15));
+}
+
+#[test]
+fn reshape_correspondence_points_steer_the_match() {
+    // Matching outlines with a zero pair change nothing; a quarter-turn offset twists.
+    let im = img(40, 40);
+    let masks = [rect_mask(10.0, 10.0, 30.0, 30.0), rect_mask(10.0, 10.0, 30.0, 30.0), rect_mask(0.0, 0.0, 40.0, 40.0)];
+    let base = [("sourceMask", Value::Enum(1)), ("destinationMask", Value::Enum(2)), ("boundaryMask", Value::Enum(3))];
+    let same = run("ec.distort.reshape", &[base.as_slice(), &[("correspondencePoints", Value::Str("0,0".into()))]].concat(), im.clone(), &masks);
+    assert!(maxd(&same.img, &im) < 1e-3, "matching outlines: no change");
+    let twisted = run("ec.distort.reshape", &[base.as_slice(), &[("correspondencePoints", Value::Str("0.25,0".into()))]].concat(), im.clone(), &masks);
+    assert!(maxd(&twisted.img, &im) > 0.1);
+    // Fraction mapping.
+    assert!((map_fraction(&[(0.0, 0.0), (0.5, 0.25)], 0.125, true) - 0.25).abs() < 1e-9);
+    assert!((map_fraction(&[(0.2, 0.0)], 0.9, true) - 0.1).abs() < 1e-9);
+    assert!((map_fraction(&[(0.5, 0.5)], 0.25, false) - 0.25).abs() < 1e-9);
+}
+
+#[test]
+fn upscale_grows_about_centre() {
+    let im = img(20, 10);
+    let o = run("ec.distort.upscale", &[("scale", num(200.0)), ("detail", num(0.0))], im.clone(), &[]);
+    assert_eq!((o.img.width, o.img.height), (40, 20));
+    // Grown about the layer centre: layer point (0,0) now sits at buffer pixel (10,5), so the
+    // centre (10,5) lands in the middle of the 40×20 buffer.
+    assert_eq!(o.offset, [10.0, 5.0]);
+    let c = o.img.sample_bilinear(20.0, 10.0);
+    assert!((c[0] - im.sample_bilinear(10.0, 5.0)[0]).abs() < 0.03);
+}
+
+#[test]
+fn twirl_legacy_rotates_inside_radius() {
+    let im = img(40, 40);
+    let o = run("ec.distort.twirllegacy", &[("angle", num(180.0)), ("radius", num(100.0))], im.clone(), &[]);
+    assert!(maxd(&o.img, &im) > 0.1);
+    // Corners lie outside the radius.
+    assert_eq!(o.img.get(0, 0), im.get(0, 0));
+}
+
+#[test]
+fn half_resolution_matches_scaled_geometry() {
+    // Bender at scale 0.5: the buffer is half size, parameters in layer pixels.
+    let s = crate::find("ec.distort.ccbender").unwrap();
+    let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+    params.values.insert("amount".into(), num(30.0));
+    params.values.insert("top".into(), pt(20.0, 0.0));
+    params.values.insert("base".into(), pt(20.0, 40.0));
+    let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [40.0, 40.0], seed: 1, adjustment: false, env: Default::default() };
+    let full = crate::apply(s, &ctx, Buf { img: img(40, 40), offset: [0.0; 2], scale: 1.0 });
+    let half = crate::apply(s, &ctx, Buf { img: effectcraft_raster::resample(&img(40, 40), 20, 20), offset: [0.0; 2], scale: 0.5 });
+    let a = full.img.sample_bilinear(20.0, 4.0)[3];
+    let b = half.img.sample_bilinear(10.0, 2.0)[3];
+    assert!((a - b).abs() < 0.3);
+}
diff --git a/crates/effects/src/generate2.rs b/crates/effects/src/generate2.rs
index fcb05d6e2..b4781b793 100644
--- a/crates/effects/src/generate2.rs
+++ b/crates/effects/src/generate2.rs
@@ -692,18 +692,33 @@ impl BoltCfg<'_> {
     }
 }
 
-/// Grow a bolt from `a` to `z` by midpoint displacement (`depth` levels), forking at random.
-/// Segments go to `out` with their intensity; `mains` marks the main core's segments.
-#[allow(clippy::too_many_arguments)]
-fn bolt(cfg: &BoltCfg, a: (f64, f64), z: (f64, f64), depth: u32, inten: f32, main: bool, rng: &mut Rng, out: &mut Vec<Seg>, mains: &mut Vec<bool>) {
-    if out.len() > 20_000 {
+/// One branch's geometry and recursive growth state.
+struct BoltBranch {
+    start: (f64, f64),
+    end: (f64, f64),
+    depth: u32,
+    intensity: f32,
+    main: bool,
+}
+
+/// Segments and their matching main-core flags, kept in the same traversal order.
+#[derive(Default)]
+struct BoltOutput {
+    segments: Vec<Seg>,
+    mains: Vec<bool>,
+}
+
+/// Grow a branch by midpoint displacement, recursively appending its segments and forks.
+fn bolt(cfg: &BoltCfg, branch: BoltBranch, rng: &mut Rng, output: &mut BoltOutput) {
+    let BoltBranch { start: a, end: z, depth, intensity: inten, main } = branch;
+    if output.segments.len() > 20_000 {
         return;
     }
     let (dx, dy) = (z.0 - a.0, z.1 - a.1);
     let len = (dx * dx + dy * dy).sqrt();
     if depth == 0 || len < 1.0 {
-        out.push((a, z, inten));
-        mains.push(main);
+        output.segments.push((a, z, inten));
+        output.mains.push(main);
         return;
     }
     let (nx, ny) = (-dy / len.max(1e-9), dx / len.max(1e-9));
@@ -725,8 +740,8 @@ fn bolt(cfg: &BoltCfg, a: (f64, f64), z: (f64, f64), depth: u32, inten: f32, mai
     if cfg.obstacle > 0.0 && !main && cfg.alpha_at(m) > 0.5 && rng.f() < cfg.obstacle / 10.0 {
         return;
     }
-    bolt(cfg, a, m, depth - 1, inten, main, rng, out, mains);
-    bolt(cfg, m, z, depth - 1, inten, main, rng, out, mains);
+    bolt(cfg, BoltBranch { start: a, end: m, depth: depth - 1, intensity: inten, main }, rng, output);
+    bolt(cfg, BoltBranch { start: m, end: z, depth: depth - 1, intensity: inten, main }, rng, output);
     if rng.f() < cfg.fork && inten > cfg.term && len >= cfg.min_fork {
         let ang = rng.s() * 0.7;
         let (s, c) = ang.sin_cos();
@@ -734,7 +749,7 @@ fn bolt(cfg: &BoltCfg, a: (f64, f64), z: (f64, f64), depth: u32, inten: f32, mai
         let k = 1.2;
         // Fork Strength 50 % keeps the decayed intensity; Fork Variation randomises it.
         let fi = inten * (1.0 - cfg.decay) * cfg.fork_strength * 2.0 * if cfg.fork_var > 0.0 { 1.0 - cfg.fork_var * rng.f() as f32 } else { 1.0 };
-        bolt(cfg, m, (m.0 + fx * k, m.1 + fy * k), depth.saturating_sub(1), fi.min(1.0), false, rng, out, mains);
+        bolt(cfg, BoltBranch { start: m, end: (m.0 + fx * k, m.1 + fy * k), depth: depth.saturating_sub(1), intensity: fi.min(1.0), main: false }, rng, output);
     }
 }
 
@@ -772,10 +787,9 @@ pub fn lightning_segments(ctx: &EffectCtx, b: &Buf) -> Vec<Seg> {
         fork_strength: (g("expertSettings/forkStrength", 50.0) / 100.0).clamp(0.0, 1.0) as f32,
         fork_var: (g("expertSettings/forkVariation", 0.0) / 100.0).clamp(0.0, 1.0) as f32,
     };
-    let mut segs = Vec::new();
-    let mut mains = Vec::new();
+    let mut output = BoltOutput::default();
     let (h, w) = (b.img.height as f64, b.img.width as f64);
-    let mut go = |a, z, depth, cfg: &BoltCfg, rng: &mut Rng| bolt(cfg, a, z, depth, 1.0, true, rng, &mut segs, &mut mains);
+    let mut go = |a, z, depth, cfg: &BoltCfg, rng: &mut Rng| bolt(cfg, BoltBranch { start: a, end: z, depth, intensity: 1.0, main: true }, rng, &mut output);
     // LIGHTNING_TYPES order.
     match kind {
         // Direction: travels toward the Direction point and beyond.
@@ -811,6 +825,7 @@ pub fn lightning_segments(ctx: &EffectCtx, b: &Buf) -> Vec<Seg> {
         // Strike.
         _ => go(o, d, depth, &cfg, &mut rng),
     }
+    let BoltOutput { segments: mut segs, mains } = output;
     let dist = |p: (f64, f64)| ((p.0 - o.0).powi(2) + (p.1 - o.1).powi(2)).sqrt();
     let far = segs.iter().map(|(_, z, _)| dist(*z)).fold(1e-9, f64::max);
     // Decay Main Core: the whole bolt fades with distance from the origin.
@@ -1223,315 +1238,4 @@ pub fn specs() -> Vec<EffectSpec> {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::Params;
-    use effectcraft_raster::Image;
-
-    fn run(id: &str, set: &[(&str, Value)], img: Image) -> Buf {
-        let s = crate::find(id).unwrap();
-        let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-        let ls = [img.width as f64, img.height as f64];
-        for p in &s.params {
-            if let (ParamUi::Point, Value::Vec2(v)) = (&p.ui, &p.default) {
-                params.values.insert(p.id.to_string(), Value::Vec2([v[0] * ls[0], v[1] * ls[1]]));
-            }
-        }
-        for (k, v) in set {
-            params.values.insert(k.to_string(), v.clone());
-        }
-        let ctx = EffectCtx { params: &params, time: 0.5, layer_size: ls, seed: 3, adjustment: false, env: Default::default() };
-        crate::apply(s, &ctx, Buf { img, offset: [0.0, 0.0], scale: 1.0 })
-    }
-
-    #[test]
-    fn cell_pattern_is_deterministic_and_seeded() {
-        let a = run("ec.generate.cellpattern", &[("size", num(10.0))], Image::new(40, 30));
-        let b2 = run("ec.generate.cellpattern", &[("size", num(10.0))], Image::new(40, 30));
-        assert_eq!(a.img, b2.img);
-        let c = run("ec.generate.cellpattern", &[("size", num(10.0)), ("evolutionOptions/randomSeed", num(5.0))], Image::new(40, 30));
-        assert_ne!(a.img, c.img);
-        assert!(a.img.data.iter().all(|p| p[3] == 1.0 && (0.0..=1.0).contains(&p[0])));
-    }
-
-    #[test]
-    fn ellipse_ring_coverage() {
-        let o = run("ec.generate.ellipse", &[("width", num(40.0)), ("height", num(40.0)), ("thickness", num(6.0))], Image::new(64, 64));
-        // Ring passes through (32 + 20, 32); centre is empty.
-        assert!(o.img.get(51, 32)[3] > 0.9, "{:?}", o.img.get(51, 32));
-        assert!(o.img.get(32, 32)[3] < 1e-3);
-        assert!(o.img.get(2, 2)[3] < 1e-3);
-    }
-
-    #[test]
-    fn lightning_is_deterministic_per_conductivity() {
-        let a = run("ec.generate.advancedlightning", &[], Image::new(64, 48));
-        let b2 = run("ec.generate.advancedlightning", &[], Image::new(64, 48));
-        assert_eq!(a.img, b2.img);
-        assert!(a.img.data.iter().any(|p| p[3] > 0.5));
-        let c = run("ec.generate.advancedlightning", &[("conductivityState", num(11.0))], Image::new(64, 48));
-        assert_ne!(a.img, c.img);
-    }
-
-    #[test]
-    fn beam_draws_between_points() {
-        let o = run("ec.generate.beam", &[("length", num(100.0)), ("softness", num(0.0))], Image::new(64, 32));
-        assert!(o.img.get(32, 16)[3] > 0.99);
-        assert!(o.img.get(32, 2)[3] < 1e-3);
-        assert!(o.img.get(2, 16)[3] < 1e-3);
-    }
-
-    #[test]
-    fn cell_pattern_tiles() {
-        // 4×4-cell tiles of 8 px: the pattern repeats every 32 px.
-        let set = [
-            ("size", num(8.0)),
-            ("tilingOptions/enableTiling", Value::Bool(true)),
-            ("tilingOptions/cellsHorizontal", num(4.0)),
-            ("tilingOptions/cellsVertical", num(4.0)),
-        ];
-        let o = run("ec.generate.cellpattern", &set, Image::new(64, 64));
-        for (x, y) in [(3, 5), (10, 20), (17, 2)] {
-            let (a, b2) = (o.img.get(x, y), o.img.get(x + 32, y + 32));
-            assert!((a[0] - b2[0]).abs() < 1e-4, "{x},{y}: {a:?} vs {b2:?}");
-        }
-    }
-
-    #[test]
-    fn radio_waves_expansion_velocity_and_star() {
-        let r = |set: &[(&str, Value)], t: f64| {
-            let s = crate::find("ec.generate.radiowaves").unwrap();
-            let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-            params.values.insert("producerPoint".into(), Value::Vec2([32.0, 32.0]));
-            for (k, v) in set {
-                params.values.insert(k.to_string(), v.clone());
-            }
-            let ctx = EffectCtx { params: &params, time: t, layer_size: [64.0, 64.0], seed: 3, adjustment: false, env: Default::default() };
-            crate::apply(s, &ctx, Buf { img: Image::new(64, 64), offset: [0.0, 0.0], scale: 1.0 })
-        };
-        // One wave born at t = 0, 0.2 s old: radius = Expansion × age = 20 px.
-        let base = [("waveMotion/expansion", num(100.0)), ("waveMotion/frequency", num(0.5))];
-        let o = r(&base, 0.2);
-        assert!(o.img.get(52, 32)[3] > 0.9, "{:?}", o.img.get(52, 32));
-        assert!(o.img.get(32, 32)[3] < 0.01);
-        // Velocity moves the wave toward Direction (90° = right).
-        let mut moving = base.to_vec();
-        moving.push(("waveMotion/velocity", num(50.0)));
-        let o = r(&moving, 0.2);
-        assert!(o.img.get(62, 32)[3] > 0.9 && o.img.get(52, 32)[3] < 0.5, "{:?}", o.img.get(62, 32));
-        // A 4-point star: the outline dips toward the centre between the points.
-        let mut star = base.to_vec();
-        star.extend([("polygon/sides", num(4.0)), ("polygon/star", Value::Bool(true)), ("polygon/starDepth", num(-0.5))]);
-        let o = r(&star, 0.2);
-        assert!(o.img.get(32, 12)[3] > 0.9, "point straight up");
-        // Between points (45°) the outline sits near half the radius.
-        assert!(o.img.get(39, 24)[3] > 0.5, "{:?}", o.img.get(39, 24));
-        assert!(o.img.get(46, 18)[3] < 0.01, "no circle there");
-    }
-
-    #[test]
-    fn lightning_alpha_obstacle_and_expert_settings() {
-        let sum = |i: &Image| i.data.iter().map(|p| p[3]).sum::<f32>();
-        let alpha_in = |img: &Image, src: &Image| img.data.iter().zip(&src.data).filter(|(_, s)| s[3] > 0.5).map(|(p, _)| p[3]).sum::<f32>();
-        // A wall of opaque pixels across the middle of the bolt's path.
-        let mut wall = Image::new(64, 48);
-        for y in 0..48 {
-            for x in 0..64 {
-                if (18..30).contains(&y) && x < 50 {
-                    wall.set(x, y, [0.0, 0.0, 0.0, 1.0]);
-                }
-            }
-        }
-        let opts = |o: f64| {
-            vec![("alphaObstacle", num(o)), ("compositeOnOriginal", Value::Bool(false)), ("glowSettings/glowRadius", num(0.0)), ("forking", num(60.0))]
-        };
-        let free = run("ec.generate.advancedlightning", &opts(0.0), wall.clone());
-        let avoid = run("ec.generate.advancedlightning", &opts(10.0), wall.clone());
-        assert!(alpha_in(&avoid.img, &wall) < alpha_in(&free.img, &wall), "{} vs {}", alpha_in(&avoid.img, &wall), alpha_in(&free.img, &wall));
-        // Fractal Type, Core Drain, Fork Strength, Termination Threshold, Min Fork Distance.
-        let base = run("ec.generate.advancedlightning", &[], Image::new(64, 48));
-        for (id, v) in [
-            ("expertSettings/fractalType", Value::Enum(2)),
-            ("expertSettings/coreDrain", num(100.0)),
-            ("expertSettings/forkStrength", num(100.0)),
-            ("expertSettings/forkVariation", num(100.0)),
-        ] {
-            assert_ne!(run("ec.generate.advancedlightning", &[(id, v)], Image::new(64, 48)).img, base.img, "{id}");
-        }
-        let drained = run("ec.generate.advancedlightning", &[("expertSettings/coreDrain", num(100.0))], Image::new(64, 48));
-        assert!(sum(&drained.img) < sum(&base.img));
-        let no_forks = run("ec.generate.advancedlightning", &[("expertSettings/minForkDistance", num(1000.0))], Image::new(64, 48));
-        let term = run("ec.generate.advancedlightning", &[("expertSettings/terminationThreshold", num(100.0))], Image::new(64, 48));
-        assert_eq!(no_forks.img, term.img, "no forks either way");
-        assert!(sum(&no_forks.img) < sum(&base.img));
-    }
-
-    #[test]
-    fn lightning_types_and_decay_main_core() {
-        let a = run("ec.generate.advancedlightning", &[], Image::new(64, 48));
-        let strike = run("ec.generate.advancedlightning", &[("lightningType", Value::Enum(1))], Image::new(64, 48));
-        assert_eq!(a.img, strike.img, "Strike is the default");
-        for t in 0..8 {
-            let o = run("ec.generate.advancedlightning", &[("lightningType", Value::Enum(t))], Image::new(64, 48));
-            assert!(o.img.data.iter().any(|p| p[3] > 0.3), "type {t} draws");
-        }
-        let sum = |i: &Image| i.data.iter().map(|p| p[3]).sum::<f32>();
-        let d = run("ec.generate.advancedlightning", &[("decayMainCore", Value::Bool(true)), ("decay", num(0.9))], Image::new(64, 48));
-        let n = run("ec.generate.advancedlightning", &[("decay", num(0.9))], Image::new(64, 48));
-        assert!(sum(&d.img) < sum(&n.img));
-    }
-
-    #[test]
-    fn beam_3d_perspective_controls_thickness() {
-        // Short beam near the start: with 3D Perspective its thickness comes from its position
-        // (thin, near the start); without, its head takes the full ending thickness.
-        let set = |p: bool| {
-            vec![
-                ("length", num(20.0)),
-                ("time", num(0.0)),
-                ("softness", num(0.0)),
-                ("startThickness", num(2.0)),
-                ("endThickness", num(20.0)),
-                ("perspective3d", Value::Bool(p)),
-            ]
-        };
-        let on = run("ec.generate.beam", &set(true), Image::new(64, 32));
-        let off = run("ec.generate.beam", &set(false), Image::new(64, 32));
-        let sum = |i: &Image| i.data.iter().map(|p| p[3]).sum::<f32>();
-        assert!(sum(&off.img) > sum(&on.img) * 1.5, "{} {}", sum(&off.img), sum(&on.img));
-    }
-
-    #[test]
-    fn lens_flare_brightest_at_center() {
-        let o = run("ec.generate.lensflare", &[], Image::new(64, 64));
-        let c = o.img.get(16, 16)[0];
-        assert!(c > o.img.get(60, 4)[0]);
-        assert!(c > 0.5);
-    }
-
-    fn rw(set: &[(&str, Value)], t: f64, env: crate::EffectEnv) -> Image {
-        let mut v: Vec<(&str, Value)> =
-            vec![("producerPoint", Value::Vec2([32.0, 32.0])), ("waveMotion/frequency", num(0.5)), ("waveMotion/expansion", num(100.0))];
-        v.extend_from_slice(set);
-        crate::run_fx("ec.generate.radiowaves", &v, Image::new(64, 64), t, env).img
-    }
-
-    #[test]
-    fn signed_distance_of_a_square() {
-        let (w, h) = (20, 20);
-        let inside: Vec<bool> = (0..w * h).map(|i| (5..15).contains(&(i % w)) && (5..15).contains(&(i / w))).collect();
-        let d = crate::util::signed_distance(&inside, w, h);
-        assert!((d.get(10, 10) + 4.5).abs() < 1e-4, "{}", d.get(10, 10));
-        assert!((d.get(0, 10) - 4.5).abs() < 1e-4, "{}", d.get(0, 10));
-        assert!((d.get(0, 0) - (50f32.sqrt() - 0.5)).abs() < 1e-4);
-    }
-
-    #[test]
-    fn radio_waves_mask_contours_profile_reflection_and_birth() {
-        // Mask waves: a 10×10 square mask; after 0.1 s (10 px) the wave is 10 px outside it.
-        let sq = crate::MaskShape { name: String::new(), points: vec![[27.0, 27.0], [37.0, 27.0], [37.0, 37.0], [27.0, 37.0]], closed: true, inverted: false };
-        let masks = [sq];
-        let env = crate::EffectEnv { masks: &masks, ..Default::default() };
-        let m = rw(&[("waveType", Value::Enum(2)), ("waveMask/mask", num(1.0))], 0.1, env);
-        assert!(m.get(47, 32)[3] > 0.9, "{:?}", m.get(47, 32));
-        assert!(m.get(32, 32)[3] < 0.01 && m.get(40, 32)[3] < 0.01);
-        // Rounded corner: diagonal distance 10 from (37, 37).
-        assert!(m.get(44, 44)[3] > 0.5, "{:?}", m.get(44, 44));
-        // No mask chosen: nothing drawn.
-        assert!(rw(&[("waveType", Value::Enum(2))], 0.1, env).data.iter().all(|p| p[3] == 0.0));
-        // Image Contours: the bright square of a source layer.
-        struct Src;
-        impl crate::EffectHost for Src {
-            fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
-                let mut img = Image::new(64, 64);
-                for y in 27..37 {
-                    for x in 27..37 {
-                        img.set(x, y, [1.0, 1.0, 1.0, 1.0]);
-                    }
-                }
-                Some(crate::LayerPixels { buf: Buf { img, offset: [0.0; 2], scale: 1.0 }, size: [64.0, 64.0] })
-            }
-            fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
-                None
-            }
-            fn params_at(&self, t: f64) -> Option<Params> {
-                // Colour animates from red (born at 0) to green (born later).
-                let s = crate::find("ec.generate.radiowaves").unwrap();
-                let mut p = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-                p.values.insert("producerPoint".into(), Value::Vec2([32.0, 32.0]));
-                p.values.insert("waveMotion/frequency".into(), num(1.0));
-                p.values.insert("waveMotion/expansion".into(), num(20.0));
-                p.values.insert("waveStroke/color".into(), if t < 0.5 { col(1.0, 0.0, 0.0) } else { col(0.0, 1.0, 0.0) });
-                Some(p)
-            }
-        }
-        let env = crate::EffectEnv { host: Some(&Src), ..Default::default() };
-        let ic = rw(
-            &[
-                ("waveType", Value::Enum(1)),
-                ("imageContour/sourceLayer", Value::Layer(Some(1))),
-                ("imageContour/preBlur", num(0.0)),
-                ("imageContour/tolerance", num(0.0)),
-            ],
-            0.1,
-            env,
-        );
-        assert!(ic.get(47, 32)[3] > 0.9 && ic.get(32, 32)[3] < 0.01, "{:?}", ic.get(47, 32));
-        // Source Center off the square shifts the contour onto the producer point accordingly.
-        let sh = rw(
-            &[
-                ("waveType", Value::Enum(1)),
-                ("imageContour/sourceLayer", Value::Layer(Some(1))),
-                ("imageContour/sourceCenter", Value::Vec2([22.0, 32.0])),
-                ("imageContour/preBlur", num(0.0)),
-                ("imageContour/tolerance", num(0.0)),
-            ],
-            0.1,
-            env,
-        );
-        assert!(sh.get(57, 32)[3] > 0.9, "{:?}", sh.get(57, 32));
-        // Profile: Taper Both thins the stroke edges; Square is solid across.
-        let wide = [("waveStroke/startWidth", num(10.0)), ("waveStroke/endWidth", num(10.0))];
-        let sqr = rw(&wide, 0.2, crate::EffectEnv::default());
-        let mut tap = wide.to_vec();
-        tap.push(("waveStroke/profile", Value::Enum(3)));
-        let tap = rw(&tap, 0.2, crate::EffectEnv::default());
-        assert!(sqr.get(55, 32)[3] > 0.9 && tap.get(55, 32)[3] < 0.6, "{:?} {:?}", sqr.get(55, 32), tap.get(55, 32));
-        assert!(tap.get(52, 32)[3] > 0.8);
-        // Reflection: a fast wave bounces back off the right edge.
-        let fast = [("waveMotion/velocity", num(200.0)), ("waveMotion/expansion", num(10.0))];
-        let gone = rw(&fast, 0.3, crate::EffectEnv::default());
-        let mut rf = fast.to_vec();
-        rf.push(("waveMotion/reflection", Value::Bool(true)));
-        let back = rw(&rf, 0.3, crate::EffectEnv::default());
-        let sum = |i: &Image| i.data.iter().map(|p| p[3]).sum::<f32>();
-        assert!(sum(&back) > sum(&gone) + 5.0, "{} vs {}", sum(&back), sum(&gone));
-        // Parameters Are Set At Birth: the older wave keeps red, the newer one is green.
-        let both = rw(&[("parametersAreSetAt", Value::Enum(0)), ("waveMotion/frequency", num(1.0)), ("waveMotion/expansion", num(20.0))], 1.15, env);
-        let (old, new) = (both.get(55, 32), both.get(35, 32));
-        assert!(old[0] > 0.9 && old[1] < 0.1, "{old:?}");
-        assert!(new[1] > 0.9 && new[0] < 0.1, "{new:?}");
-    }
-
-    #[test]
-    fn cell_pattern_hq_variants_antialias() {
-        let s = crate::find("ec.generate.cellpattern").unwrap();
-        let r = |pat: u32| {
-            let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-            params.values.insert("cellPattern".into(), Value::Enum(pat));
-            params.values.insert("size".into(), num(12.0));
-            let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [48.0, 48.0], seed: 1, adjustment: false, env: Default::default() };
-            crate::apply(s, &ctx, Buf { img: Image::new(48, 48), offset: [0.0; 2], scale: 1.0 }).img
-        };
-        let distinct = |img: &Image| {
-            let mut v: Vec<u32> = img.data.iter().map(|p| (p[0] * 10000.0) as u32).collect();
-            v.sort_unstable();
-            v.dedup();
-            v.len()
-        };
-        let (std, hq) = (r(4), r(9));
-        assert_eq!(CELL_PATTERNS[9], "Crystallize HQ");
-        assert_ne!(std, hq);
-        assert!(distinct(&hq) > distinct(&std) * 2, "{} vs {}", distinct(&hq), distinct(&std));
-    }
-}
+mod tests;
diff --git a/crates/effects/src/generate2/tests.rs b/crates/effects/src/generate2/tests.rs
new file mode 100644
index 000000000..c2acff446
--- /dev/null
+++ b/crates/effects/src/generate2/tests.rs
@@ -0,0 +1,309 @@
+use super::*;
+use crate::Params;
+use effectcraft_raster::Image;
+
+fn run(id: &str, set: &[(&str, Value)], img: Image) -> Buf {
+    let s = crate::find(id).unwrap();
+    let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+    let ls = [img.width as f64, img.height as f64];
+    for p in &s.params {
+        if let (ParamUi::Point, Value::Vec2(v)) = (&p.ui, &p.default) {
+            params.values.insert(p.id.to_string(), Value::Vec2([v[0] * ls[0], v[1] * ls[1]]));
+        }
+    }
+    for (k, v) in set {
+        params.values.insert(k.to_string(), v.clone());
+    }
+    let ctx = EffectCtx { params: &params, time: 0.5, layer_size: ls, seed: 3, adjustment: false, env: Default::default() };
+    crate::apply(s, &ctx, Buf { img, offset: [0.0, 0.0], scale: 1.0 })
+}
+
+#[test]
+fn cell_pattern_is_deterministic_and_seeded() {
+    let a = run("ec.generate.cellpattern", &[("size", num(10.0))], Image::new(40, 30));
+    let b2 = run("ec.generate.cellpattern", &[("size", num(10.0))], Image::new(40, 30));
+    assert_eq!(a.img, b2.img);
+    let c = run("ec.generate.cellpattern", &[("size", num(10.0)), ("evolutionOptions/randomSeed", num(5.0))], Image::new(40, 30));
+    assert_ne!(a.img, c.img);
+    assert!(a.img.data.iter().all(|p| p[3] == 1.0 && (0.0..=1.0).contains(&p[0])));
+}
+
+#[test]
+fn ellipse_ring_coverage() {
+    let o = run("ec.generate.ellipse", &[("width", num(40.0)), ("height", num(40.0)), ("thickness", num(6.0))], Image::new(64, 64));
+    // Ring passes through (32 + 20, 32); centre is empty.
+    assert!(o.img.get(51, 32)[3] > 0.9, "{:?}", o.img.get(51, 32));
+    assert!(o.img.get(32, 32)[3] < 1e-3);
+    assert!(o.img.get(2, 2)[3] < 1e-3);
+}
+
+#[test]
+fn lightning_is_deterministic_per_conductivity() {
+    let a = run("ec.generate.advancedlightning", &[], Image::new(64, 48));
+    let b2 = run("ec.generate.advancedlightning", &[], Image::new(64, 48));
+    assert_eq!(a.img, b2.img);
+    assert!(a.img.data.iter().any(|p| p[3] > 0.5));
+    let c = run("ec.generate.advancedlightning", &[("conductivityState", num(11.0))], Image::new(64, 48));
+    assert_ne!(a.img, c.img);
+}
+
+#[test]
+fn beam_draws_between_points() {
+    let o = run("ec.generate.beam", &[("length", num(100.0)), ("softness", num(0.0))], Image::new(64, 32));
+    assert!(o.img.get(32, 16)[3] > 0.99);
+    assert!(o.img.get(32, 2)[3] < 1e-3);
+    assert!(o.img.get(2, 16)[3] < 1e-3);
+}
+
+#[test]
+fn cell_pattern_tiles() {
+    // 4×4-cell tiles of 8 px: the pattern repeats every 32 px.
+    let set = [
+        ("size", num(8.0)),
+        ("tilingOptions/enableTiling", Value::Bool(true)),
+        ("tilingOptions/cellsHorizontal", num(4.0)),
+        ("tilingOptions/cellsVertical", num(4.0)),
+    ];
+    let o = run("ec.generate.cellpattern", &set, Image::new(64, 64));
+    for (x, y) in [(3, 5), (10, 20), (17, 2)] {
+        let (a, b2) = (o.img.get(x, y), o.img.get(x + 32, y + 32));
+        assert!((a[0] - b2[0]).abs() < 1e-4, "{x},{y}: {a:?} vs {b2:?}");
+    }
+}
+
+#[test]
+fn radio_waves_expansion_velocity_and_star() {
+    let r = |set: &[(&str, Value)], t: f64| {
+        let s = crate::find("ec.generate.radiowaves").unwrap();
+        let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+        params.values.insert("producerPoint".into(), Value::Vec2([32.0, 32.0]));
+        for (k, v) in set {
+            params.values.insert(k.to_string(), v.clone());
+        }
+        let ctx = EffectCtx { params: &params, time: t, layer_size: [64.0, 64.0], seed: 3, adjustment: false, env: Default::default() };
+        crate::apply(s, &ctx, Buf { img: Image::new(64, 64), offset: [0.0, 0.0], scale: 1.0 })
+    };
+    // One wave born at t = 0, 0.2 s old: radius = Expansion × age = 20 px.
+    let base = [("waveMotion/expansion", num(100.0)), ("waveMotion/frequency", num(0.5))];
+    let o = r(&base, 0.2);
+    assert!(o.img.get(52, 32)[3] > 0.9, "{:?}", o.img.get(52, 32));
+    assert!(o.img.get(32, 32)[3] < 0.01);
+    // Velocity moves the wave toward Direction (90° = right).
+    let mut moving = base.to_vec();
+    moving.push(("waveMotion/velocity", num(50.0)));
+    let o = r(&moving, 0.2);
+    assert!(o.img.get(62, 32)[3] > 0.9 && o.img.get(52, 32)[3] < 0.5, "{:?}", o.img.get(62, 32));
+    // A 4-point star: the outline dips toward the centre between the points.
+    let mut star = base.to_vec();
+    star.extend([("polygon/sides", num(4.0)), ("polygon/star", Value::Bool(true)), ("polygon/starDepth", num(-0.5))]);
+    let o = r(&star, 0.2);
+    assert!(o.img.get(32, 12)[3] > 0.9, "point straight up");
+    // Between points (45°) the outline sits near half the radius.
+    assert!(o.img.get(39, 24)[3] > 0.5, "{:?}", o.img.get(39, 24));
+    assert!(o.img.get(46, 18)[3] < 0.01, "no circle there");
+}
+
+#[test]
+fn lightning_alpha_obstacle_and_expert_settings() {
+    let sum = |i: &Image| i.data.iter().map(|p| p[3]).sum::<f32>();
+    let alpha_in = |img: &Image, src: &Image| img.data.iter().zip(&src.data).filter(|(_, s)| s[3] > 0.5).map(|(p, _)| p[3]).sum::<f32>();
+    // A wall of opaque pixels across the middle of the bolt's path.
+    let mut wall = Image::new(64, 48);
+    for y in 0..48 {
+        for x in 0..64 {
+            if (18..30).contains(&y) && x < 50 {
+                wall.set(x, y, [0.0, 0.0, 0.0, 1.0]);
+            }
+        }
+    }
+    let opts =
+        |o: f64| vec![("alphaObstacle", num(o)), ("compositeOnOriginal", Value::Bool(false)), ("glowSettings/glowRadius", num(0.0)), ("forking", num(60.0))];
+    let free = run("ec.generate.advancedlightning", &opts(0.0), wall.clone());
+    let avoid = run("ec.generate.advancedlightning", &opts(10.0), wall.clone());
+    assert!(alpha_in(&avoid.img, &wall) < alpha_in(&free.img, &wall), "{} vs {}", alpha_in(&avoid.img, &wall), alpha_in(&free.img, &wall));
+    // Fractal Type, Core Drain, Fork Strength, Termination Threshold, Min Fork Distance.
+    let base = run("ec.generate.advancedlightning", &[], Image::new(64, 48));
+    for (id, v) in [
+        ("expertSettings/fractalType", Value::Enum(2)),
+        ("expertSettings/coreDrain", num(100.0)),
+        ("expertSettings/forkStrength", num(100.0)),
+        ("expertSettings/forkVariation", num(100.0)),
+    ] {
+        assert_ne!(run("ec.generate.advancedlightning", &[(id, v)], Image::new(64, 48)).img, base.img, "{id}");
+    }
+    let drained = run("ec.generate.advancedlightning", &[("expertSettings/coreDrain", num(100.0))], Image::new(64, 48));
+    assert!(sum(&drained.img) < sum(&base.img));
+    let no_forks = run("ec.generate.advancedlightning", &[("expertSettings/minForkDistance", num(1000.0))], Image::new(64, 48));
+    let term = run("ec.generate.advancedlightning", &[("expertSettings/terminationThreshold", num(100.0))], Image::new(64, 48));
+    assert_eq!(no_forks.img, term.img, "no forks either way");
+    assert!(sum(&no_forks.img) < sum(&base.img));
+}
+
+#[test]
+fn lightning_types_and_decay_main_core() {
+    let a = run("ec.generate.advancedlightning", &[], Image::new(64, 48));
+    let strike = run("ec.generate.advancedlightning", &[("lightningType", Value::Enum(1))], Image::new(64, 48));
+    assert_eq!(a.img, strike.img, "Strike is the default");
+    for t in 0..8 {
+        let o = run("ec.generate.advancedlightning", &[("lightningType", Value::Enum(t))], Image::new(64, 48));
+        assert!(o.img.data.iter().any(|p| p[3] > 0.3), "type {t} draws");
+    }
+    let sum = |i: &Image| i.data.iter().map(|p| p[3]).sum::<f32>();
+    let d = run("ec.generate.advancedlightning", &[("decayMainCore", Value::Bool(true)), ("decay", num(0.9))], Image::new(64, 48));
+    let n = run("ec.generate.advancedlightning", &[("decay", num(0.9))], Image::new(64, 48));
+    assert!(sum(&d.img) < sum(&n.img));
+}
+
+#[test]
+fn beam_3d_perspective_controls_thickness() {
+    // Short beam near the start: with 3D Perspective its thickness comes from its position
+    // (thin, near the start); without, its head takes the full ending thickness.
+    let set = |p: bool| {
+        vec![
+            ("length", num(20.0)),
+            ("time", num(0.0)),
+            ("softness", num(0.0)),
+            ("startThickness", num(2.0)),
+            ("endThickness", num(20.0)),
+            ("perspective3d", Value::Bool(p)),
+        ]
+    };
+    let on = run("ec.generate.beam", &set(true), Image::new(64, 32));
+    let off = run("ec.generate.beam", &set(false), Image::new(64, 32));
+    let sum = |i: &Image| i.data.iter().map(|p| p[3]).sum::<f32>();
+    assert!(sum(&off.img) > sum(&on.img) * 1.5, "{} {}", sum(&off.img), sum(&on.img));
+}
+
+#[test]
+fn lens_flare_brightest_at_center() {
+    let o = run("ec.generate.lensflare", &[], Image::new(64, 64));
+    let c = o.img.get(16, 16)[0];
+    assert!(c > o.img.get(60, 4)[0]);
+    assert!(c > 0.5);
+}
+
+fn rw(set: &[(&str, Value)], t: f64, env: crate::EffectEnv) -> Image {
+    let mut v: Vec<(&str, Value)> =
+        vec![("producerPoint", Value::Vec2([32.0, 32.0])), ("waveMotion/frequency", num(0.5)), ("waveMotion/expansion", num(100.0))];
+    v.extend_from_slice(set);
+    crate::run_fx("ec.generate.radiowaves", &v, Image::new(64, 64), t, env).img
+}
+
+#[test]
+fn signed_distance_of_a_square() {
+    let (w, h) = (20, 20);
+    let inside: Vec<bool> = (0..w * h).map(|i| (5..15).contains(&(i % w)) && (5..15).contains(&(i / w))).collect();
+    let d = crate::util::signed_distance(&inside, w, h);
+    assert!((d.get(10, 10) + 4.5).abs() < 1e-4, "{}", d.get(10, 10));
+    assert!((d.get(0, 10) - 4.5).abs() < 1e-4, "{}", d.get(0, 10));
+    assert!((d.get(0, 0) - (50f32.sqrt() - 0.5)).abs() < 1e-4);
+}
+
+#[test]
+fn radio_waves_mask_contours_profile_reflection_and_birth() {
+    // Mask waves: a 10×10 square mask; after 0.1 s (10 px) the wave is 10 px outside it.
+    let sq = crate::MaskShape { name: String::new(), points: vec![[27.0, 27.0], [37.0, 27.0], [37.0, 37.0], [27.0, 37.0]], closed: true, inverted: false };
+    let masks = [sq];
+    let env = crate::EffectEnv { masks: &masks, ..Default::default() };
+    let m = rw(&[("waveType", Value::Enum(2)), ("waveMask/mask", num(1.0))], 0.1, env);
+    assert!(m.get(47, 32)[3] > 0.9, "{:?}", m.get(47, 32));
+    assert!(m.get(32, 32)[3] < 0.01 && m.get(40, 32)[3] < 0.01);
+    // Rounded corner: diagonal distance 10 from (37, 37).
+    assert!(m.get(44, 44)[3] > 0.5, "{:?}", m.get(44, 44));
+    // No mask chosen: nothing drawn.
+    assert!(rw(&[("waveType", Value::Enum(2))], 0.1, env).data.iter().all(|p| p[3] == 0.0));
+    // Image Contours: the bright square of a source layer.
+    struct Src;
+    impl crate::EffectHost for Src {
+        fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
+            let mut img = Image::new(64, 64);
+            for y in 27..37 {
+                for x in 27..37 {
+                    img.set(x, y, [1.0, 1.0, 1.0, 1.0]);
+                }
+            }
+            Some(crate::LayerPixels { buf: Buf { img, offset: [0.0; 2], scale: 1.0 }, size: [64.0, 64.0] })
+        }
+        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+            None
+        }
+        fn params_at(&self, t: f64) -> Option<Params> {
+            // Colour animates from red (born at 0) to green (born later).
+            let s = crate::find("ec.generate.radiowaves").unwrap();
+            let mut p = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+            p.values.insert("producerPoint".into(), Value::Vec2([32.0, 32.0]));
+            p.values.insert("waveMotion/frequency".into(), num(1.0));
+            p.values.insert("waveMotion/expansion".into(), num(20.0));
+            p.values.insert("waveStroke/color".into(), if t < 0.5 { col(1.0, 0.0, 0.0) } else { col(0.0, 1.0, 0.0) });
+            Some(p)
+        }
+    }
+    let env = crate::EffectEnv { host: Some(&Src), ..Default::default() };
+    let ic = rw(
+        &[
+            ("waveType", Value::Enum(1)),
+            ("imageContour/sourceLayer", Value::Layer(Some(1))),
+            ("imageContour/preBlur", num(0.0)),
+            ("imageContour/tolerance", num(0.0)),
+        ],
+        0.1,
+        env,
+    );
+    assert!(ic.get(47, 32)[3] > 0.9 && ic.get(32, 32)[3] < 0.01, "{:?}", ic.get(47, 32));
+    // Source Center off the square shifts the contour onto the producer point accordingly.
+    let sh = rw(
+        &[
+            ("waveType", Value::Enum(1)),
+            ("imageContour/sourceLayer", Value::Layer(Some(1))),
+            ("imageContour/sourceCenter", Value::Vec2([22.0, 32.0])),
+            ("imageContour/preBlur", num(0.0)),
+            ("imageContour/tolerance", num(0.0)),
+        ],
+        0.1,
+        env,
+    );
+    assert!(sh.get(57, 32)[3] > 0.9, "{:?}", sh.get(57, 32));
+    // Profile: Taper Both thins the stroke edges; Square is solid across.
+    let wide = [("waveStroke/startWidth", num(10.0)), ("waveStroke/endWidth", num(10.0))];
+    let sqr = rw(&wide, 0.2, crate::EffectEnv::default());
+    let mut tap = wide.to_vec();
+    tap.push(("waveStroke/profile", Value::Enum(3)));
+    let tap = rw(&tap, 0.2, crate::EffectEnv::default());
+    assert!(sqr.get(55, 32)[3] > 0.9 && tap.get(55, 32)[3] < 0.6, "{:?} {:?}", sqr.get(55, 32), tap.get(55, 32));
+    assert!(tap.get(52, 32)[3] > 0.8);
+    // Reflection: a fast wave bounces back off the right edge.
+    let fast = [("waveMotion/velocity", num(200.0)), ("waveMotion/expansion", num(10.0))];
+    let gone = rw(&fast, 0.3, crate::EffectEnv::default());
+    let mut rf = fast.to_vec();
+    rf.push(("waveMotion/reflection", Value::Bool(true)));
+    let back = rw(&rf, 0.3, crate::EffectEnv::default());
+    let sum = |i: &Image| i.data.iter().map(|p| p[3]).sum::<f32>();
+    assert!(sum(&back) > sum(&gone) + 5.0, "{} vs {}", sum(&back), sum(&gone));
+    // Parameters Are Set At Birth: the older wave keeps red, the newer one is green.
+    let both = rw(&[("parametersAreSetAt", Value::Enum(0)), ("waveMotion/frequency", num(1.0)), ("waveMotion/expansion", num(20.0))], 1.15, env);
+    let (old, new) = (both.get(55, 32), both.get(35, 32));
+    assert!(old[0] > 0.9 && old[1] < 0.1, "{old:?}");
+    assert!(new[1] > 0.9 && new[0] < 0.1, "{new:?}");
+}
+
+#[test]
+fn cell_pattern_hq_variants_antialias() {
+    let s = crate::find("ec.generate.cellpattern").unwrap();
+    let r = |pat: u32| {
+        let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+        params.values.insert("cellPattern".into(), Value::Enum(pat));
+        params.values.insert("size".into(), num(12.0));
+        let ctx = EffectCtx { params: &params, time: 0.0, layer_size: [48.0, 48.0], seed: 1, adjustment: false, env: Default::default() };
+        crate::apply(s, &ctx, Buf { img: Image::new(48, 48), offset: [0.0; 2], scale: 1.0 }).img
+    };
+    let distinct = |img: &Image| {
+        let mut v: Vec<u32> = img.data.iter().map(|p| (p[0] * 10000.0) as u32).collect();
+        v.sort_unstable();
+        v.dedup();
+        v.len()
+    };
+    let (std, hq) = (r(4), r(9));
+    assert_eq!(CELL_PATTERNS[9], "Crystallize HQ");
+    assert_ne!(std, hq);
+    assert!(distinct(&hq) > distinct(&std) * 2, "{} vs {}", distinct(&hq), distinct(&std));
+}
diff --git a/crates/effects/src/generate3.rs b/crates/effects/src/generate3.rs
index 9e22ac8ae..a61c3f769 100644
--- a/crates/effects/src/generate3.rs
+++ b/crates/effects/src/generate3.rs
@@ -17,2430 +17,26 @@ use rayon::prelude::*;
 use crate::util::{Plane, gauss_plane, hash1, layer_or_self, morph_frac, poly_length, premul, smoothstep, unpremul};
 use crate::{Buf, EffectCtx, EffectSpec, Params, col, num, p, popup, slider};
 
-fn spec(id: &'static str, name: &'static str, params: Vec<crate::ParamSpec>, render: crate::RenderFn) -> EffectSpec {
-    EffectSpec { id, name, category: "Generate", params, render, gpu: false, float: true }
-}
-
-fn pt(x: f64, y: f64) -> Value {
-    Value::Vec2([x, y])
-}
-
-fn pct() -> ParamUi {
-    slider(0.0, 100.0, 0.0, 100.0, 1)
-}
-
-// ---------------------------------------------------------------- shared rasterisation
-
-/// A round-capped line segment in buffer pixels with radius `r` and intensity `v`.
-#[derive(Clone, Copy, Debug)]
-pub struct Seg {
-    pub a: [f64; 2],
-    pub b: [f64; 2],
-    pub r: f64,
-    pub v: f32,
-}
-
-/// Rasterise segments into a coverage plane (max-combined). `hardness` (0..1) is the fraction
-/// of the radius that is fully opaque; the rest falls off smoothly.
-pub(crate) fn raster_segs(w: usize, h: usize, segs: &[Seg], hardness: f64) -> Plane {
-    let mut out = Plane::new(w, h);
-    if w == 0 || h == 0 || segs.is_empty() {
-        return out;
-    }
-    let mut buckets: Vec<Vec<u32>> = vec![Vec::new(); h];
-    for (i, s) in segs.iter().enumerate() {
-        let pad = s.r + 1.0;
-        let y0 = (s.a[1].min(s.b[1]) - pad).floor().max(0.0) as usize;
-        let y1 = (s.a[1].max(s.b[1]) + pad).ceil().min(h as f64);
-        if y1 <= 0.0 || y0 >= h {
-            continue;
-        }
-        for row in buckets.iter_mut().take(y1 as usize).skip(y0) {
-            row.push(i as u32);
-        }
-    }
-    let hard = hardness.clamp(0.0, 1.0);
-    out.data.par_chunks_mut(w).enumerate().for_each(|(y, row)| {
-        let py = y as f64 + 0.5;
-        for &i in &buckets[y] {
-            let s = segs[i as usize];
-            let pad = s.r + 1.0;
-            let x0 = (s.a[0].min(s.b[0]) - pad).floor().max(0.0) as usize;
-            let x1 = ((s.a[0].max(s.b[0]) + pad).ceil().max(0.0) as usize).min(w);
-            let (dx, dy) = (s.b[0] - s.a[0], s.b[1] - s.a[1]);
-            let l2 = dx * dx + dy * dy;
-            let inner = s.r * hard - 0.5;
-            let outer = s.r + 0.5;
-            for (x, o) in row.iter_mut().enumerate().take(x1).skip(x0) {
-                let px = x as f64 + 0.5;
-                let t = if l2 > 1e-12 { (((px - s.a[0]) * dx + (py - s.a[1]) * dy) / l2).clamp(0.0, 1.0) } else { 0.0 };
-                let d = ((px - s.a[0] - dx * t).powi(2) + (py - s.a[1] - dy * t).powi(2)).sqrt();
-                if d >= outer {
-                    continue;
-                }
-                let c = if d <= inner { 1.0 } else { 1.0 - smoothstep(inner as f32, outer as f32, d as f32) } * s.v;
-                if c > *o {
-                    *o = c;
-                }
-            }
-        }
-    });
-    out
-}
-
-/// Segments along a polyline (buffer px).
-pub fn poly_segs(pts: &[[f64; 2]], closed: bool, r: f64, v: f32, out: &mut Vec<Seg>) {
-    let n = pts.len();
-    if n == 1 {
-        out.push(Seg { a: pts[0], b: pts[0], r, v });
-    }
-    if n < 2 {
-        return;
-    }
-    let segs = if closed { n } else { n - 1 };
-    for i in 0..segs {
-        out.push(Seg { a: pts[i], b: pts[(i + 1) % n], r, v });
-    }
-}
-
-/// Portion `[s0, s1]` (arc length) of a polyline.
-pub(crate) fn trim_poly(pts: &[[f64; 2]], closed: bool, s0: f64, s1: f64) -> Vec<[f64; 2]> {
-    let n = pts.len();
-    let mut out = Vec::new();
-    if n < 2 || s1 <= s0 {
-        return out;
-    }
-    let segs = if closed { n } else { n - 1 };
-    let mut acc = 0.0;
-    for i in 0..segs {
-        let (a, b) = (pts[i], pts[(i + 1) % n]);
-        let l = ((b[0] - a[0]).powi(2) + (b[1] - a[1]).powi(2)).sqrt();
-        let (e0, e1) = (acc, acc + l);
-        acc = e1;
-        if e1 < s0 || e0 > s1 || l <= 0.0 {
-            continue;
-        }
-        let at = |s: f64| {
-            let t = ((s - e0) / l).clamp(0.0, 1.0);
-            [a[0] + (b[0] - a[0]) * t, a[1] + (b[1] - a[1]) * t]
-        };
-        let p0 = at(s0.max(e0));
-        if out.last() != Some(&p0) {
-            out.push(p0);
-        }
-        out.push(at(s1.min(e1)));
-    }
-    out
-}
-
-/// How painted coverage meets the layer: 0 On Original Image, 1 On Transparent, 2 Reveal
-/// Original Image.
-pub(crate) fn paint(img: &mut Image, cov: &Plane, color: [f32; 4], opacity: f32, style: u32) {
-    img.data.par_iter_mut().zip(cov.data.par_iter()).for_each(|(px, &c)| {
-        let a = (c * opacity * color[3]).clamp(0.0, 1.0);
-        let s = [color[0] * a, color[1] * a, color[2] * a, a];
-        *px = match style {
-            1 => s,
-            2 => [px[0] * a, px[1] * a, px[2] * a, px[3] * a],
-            _ => over(*px, s),
-        };
-    });
-}
-
-/// Coverage of a plan-drawn generator: round-capped segments rasterised by `raster_segs`
-/// with `hardness`, or the union of convex polygons (`raster_convex`).
-#[derive(Clone, Debug)]
-pub enum Coverage {
-    Segs { segs: Vec<Seg>, hardness: f64 },
-    Convex(Vec<Vec<[f64; 2]>>),
-}
-
-impl Coverage {
-    fn raster(&self, w: usize, h: usize) -> Plane {
-        match self {
-            Coverage::Segs { segs, hardness } => raster_segs(w, h, segs, *hardness),
-            Coverage::Convex(polys) => raster_convex(w, h, polys),
-        }
-    }
-}
-
-/// Stroke, Scribble, Vegas and Write-on, shared with the GPU compositor (effectcraft-gpu
-/// `fx_gen2`): the coverage and how it is painted. `style` 0–2 as `paint` (On Original
-/// Image, On Transparent, Reveal Original Image), 3 = under the layer (Vegas' Composite Under).
-#[derive(Clone, Debug)]
-pub struct PaintPlan {
-    pub cov: Coverage,
-    pub color: [f32; 4],
-    pub opacity: f32,
-    pub style: u32,
-}
-
-/// Draw a [`PaintPlan`].
-fn draw_paint(b: &mut Buf, plan: &PaintPlan) {
-    let cov = plan.cov.raster(b.img.width as usize, b.img.height as usize);
-    if plan.style == 3 {
-        let color = plan.color;
-        b.img.data.par_iter_mut().zip(cov.data.par_iter()).for_each(|(px, &c)| {
-            let a = c * color[3];
-            *px = over([color[0] * a, color[1] * a, color[2] * a, a], *px);
-        });
-    } else {
-        paint(&mut b.img, &cov, plan.color, plan.opacity, plan.style);
-    }
-}
-
-/// Generators drawn from a plan that need the layer's own pixels (`b.img`) to build it.
-pub fn plan_reads_pixels(id: &str, ctx: &EffectCtx) -> bool {
-    match id {
-        // Image Contours read the layer itself when no (resolvable) Input Layer is chosen.
-        "ec.generate.vegas" => ctx.params.e("stroke") == 0,
-        "ec.generate.paintbucket" | "ec.generate.eyedropperfill" => true,
-        "ec.generate.advancedlightning" => ctx.params.f("alphaObstacle").clamp(-10.0, 10.0) != 0.0,
-        _ => false,
-    }
-}
-
-/// [`PaintPlan`] of Stroke, Scribble, Vegas or Write-on on `b`'s geometry (`b.img` is read
-/// only when [`plan_reads_pixels`]). `None`: Scribble without a usable mask (the layer is
-/// cleared when it composites On Transparent, else kept).
-pub fn paint_plan(id: &str, ctx: &EffectCtx, b: &Buf) -> Option<PaintPlan> {
-    match id {
-        "ec.generate.stroke" => Some(stroke_plan(ctx, b)),
-        "ec.generate.scribble" => scribble_plan(ctx, b),
-        "ec.generate.vegas" => Some(vegas_plan(ctx, b)),
-        "ec.generate.writeon" => Some(write_on_plan(ctx, b)),
-        _ => None,
-    }
-}
-
-/// Scribble's Composite as a `paint` style.
-pub fn scribble_style(ctx: &EffectCtx) -> u32 {
-    match ctx.params.e("composite") {
-        0 => 0,
-        2 => 2,
-        _ => 1,
-    }
-}
-
-#[inline]
-fn over(dst: Px, src: Px) -> Px {
-    let k = 1.0 - src[3];
-    [src[0] + dst[0] * k, src[1] + dst[1] * k, src[2] + dst[2] * k, src[3] + dst[3] * k]
-}
-
-/// Mask `idx` (1-based; 0 = none) mapped to buffer pixels.
-pub(crate) fn mask_px(ctx: &EffectCtx, b: &Buf, idx: usize) -> Option<(Vec<[f64; 2]>, bool, bool)> {
-    let m = ctx.env.masks.get(idx.checked_sub(1)?)?;
-    if m.points.is_empty() {
-        return None;
-    }
-    Some((m.points.iter().map(|&q| [q[0] * b.scale + b.offset[0], q[1] * b.scale + b.offset[1]]).collect(), m.closed, m.inverted))
-}
-
-/// All masks mapped to buffer pixels.
-fn all_masks_px(ctx: &EffectCtx, b: &Buf) -> Vec<(Vec<[f64; 2]>, bool, bool)> {
-    (1..=ctx.env.masks.len()).filter_map(|i| mask_px(ctx, b, i)).collect()
-}
-
-/// Chaikin corner cutting (open polyline, endpoints kept).
-fn chaikin(pts: &[[f64; 2]], iters: usize) -> Vec<[f64; 2]> {
-    let mut cur = pts.to_vec();
-    for _ in 0..iters {
-        if cur.len() < 3 {
-            return cur;
-        }
-        let mut nx = Vec::with_capacity(cur.len() * 2);
-        nx.push(cur[0]);
-        for w in cur.windows(2) {
-            let (a, b) = (w[0], w[1]);
-            nx.push([a[0] * 0.75 + b[0] * 0.25, a[1] * 0.75 + b[1] * 0.25]);
-            nx.push([a[0] * 0.25 + b[0] * 0.75, a[1] * 0.25 + b[1] * 0.75]);
-        }
-        nx.push(*cur.last().unwrap_or(&[0.0; 2]));
-        cur = nx;
-    }
-    cur
-}
-
-// ---------------------------------------------------------------- Fractal
-
-#[derive(Clone, Copy)]
-struct FracSet {
-    /// Mandelbrot iterations start at the Julia centre (the "Over Julia" set choices).
-    over_julia: bool,
-    julia: bool,
-    inverse: bool,
-}
-
-/// Smooth escape count, or `None` inside the set.
-fn escape(z0: (f64, f64), c: (f64, f64), power: u32, limit: f64, max_iter: u32) -> Option<f64> {
-    let (mut x, mut y) = z0;
-    let lim2 = limit * limit;
-    for i in 0..max_iter {
-        let (nx, ny) = match power {
-            3 => (x * x * x - 3.0 * x * y * y, 3.0 * x * x * y - y * y * y),
-            4 => {
-                let (a, b) = (x * x - y * y, 2.0 * x * y);
-                (a * a - b * b, 2.0 * a * b)
-            }
-            _ => (x * x - y * y, 2.0 * x * y),
-        };
-        x = nx + c.0;
-        y = ny + c.1;
-        let m2 = x * x + y * y;
-        if m2 > lim2 {
-            let lz = m2.ln() * 0.5;
-            let nu = (lz / limit.max(1.0001).ln()).max(1e-9).ln() / (power as f64).ln();
-            return Some((i as f64 + 1.0 - nu).max(0.0));
-        }
-    }
-    None
-}
-
-/// Fractal Set Choice options.
-pub(crate) const FRACTAL_SETS: [&str; 6] =
-    ["Mandelbrot", "Mandelbrot Inverse", "Mandelbrot Over Julia", "Mandelbrot Inverse Over Julia", "Julia", "Julia Inverse"];
-/// Fractal Palette options.
-pub(crate) const FRACTAL_PALETTES: [&str; 4] = ["Lightness Gradient", "Hue Wheel", "Black And White", "Solid Color"];
-/// Fractal Oversample Method options.
-pub(crate) const FRACTAL_OVERSAMPLE: [&str; 2] = ["Edge Detect-Fast-May Miss Pixels", "Brute Force-Slow-Every Pixel"];
-
-fn fractal(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let pr = ctx.params;
-    let set_choice = pr.e("setChoice");
-    let power = 2 + pr.e("equation").min(2);
-    let mc = (pr.f("mandelbrot/mandelbrotX"), pr.f("mandelbrot/mandelbrotY"));
-    let mmag = pr.f("mandelbrot/mandelbrotMagnification");
-    let mlim = pr.f("mandelbrot/mandelbrotEscapeLimit").max(1.01);
-    let jc = (pr.f("julia/juliaX"), pr.f("julia/juliaY"));
-    let jmag = pr.f("julia/juliaMagnification");
-    let jlim = pr.f("julia/juliaEscapeLimit").max(1.01);
-    let post = (pr.f("postInversionOffset/postInversionX"), pr.f("postInversionOffset/postInversionY"));
-    let overlay = pr.b("fractalColor/overlay");
-    let transparency = pr.b("fractalColor/transparency");
-    let transparent_inside = transparency || overlay;
-    let palette = pr.e("fractalColor/palette");
-    let hue = (pr.f("fractalColor/hue") / 360.0) as f32;
-    let steps = pr.f("fractalColor/cycleSteps").max(1.0);
-    let cyc_off = pr.f("fractalColor/cycleOffset") / 360.0;
-    let edge = pr.b("fractalColor/edgeHighlight");
-    let every = pr.e("highQualitySettings/samplingMethod") == 1;
-    let factor = pr.f("highQualitySettings/samplingFactor").round().clamp(1.0, 9.0) as usize;
-    let (w, h) = (b.img.width as usize, b.img.height as usize);
-    let lw = ctx.layer_size[0].max(1.0);
-    let lh = ctx.layer_size[1].max(1.0);
-    let inv = 1.0 / b.scale.max(1e-9);
-    let (off_x, off_y) = (b.offset[0], b.offset[1]);
-    // FRACTAL_SETS order.
-    let set = |julia, inverse, over_julia| FracSet { over_julia, julia, inverse };
-    let sets: (FracSet, Option<FracSet>) = match set_choice {
-        1 => (set(false, true, false), None),
-        2 => (set(false, false, true), None),
-        3 => (set(false, true, true), None),
-        4 => (set(true, false, false), None),
-        5 => (set(true, true, false), None),
-        _ => (set(false, false, false), None),
-    };
-    let iter_for = |mag: f64| (96.0 + 48.0 * mag.max(0.0)).clamp(64.0, 3000.0) as u32;
-    let eval_set = |s: FracSet, lx: f64, ly: f64| -> Option<f64> {
-        let (center, mag, lim) = if s.julia { (jc, jmag, jlim) } else { (mc, mmag, mlim) };
-        let span = 3.5 / 2f64.powf(mag);
-        let mut u = (lx - lw * 0.5) / lw * span + center.0;
-        let mut v = (ly - lh * 0.5) / lw * span + center.1;
-        if s.inverse {
-            let d = (u * u + v * v).max(1e-12);
-            u = u / d + post.0;
-            v = -v / d + post.1;
-        }
-        if s.julia {
-            escape((u, v), mc, power, lim, iter_for(mag))
-        } else {
-            let z0 = if s.over_julia { jc } else { (0.0, 0.0) };
-            escape(z0, (u, v), power, lim, iter_for(mag))
-        }
-    };
-    let eval = |lx: f64, ly: f64| -> Option<f64> {
-        let a = eval_set(sets.0, lx, ly);
-        match (a, sets.1) {
-            (None, Some(s2)) => eval_set(s2, lx, ly),
-            _ => a,
-        }
-    };
-    let shade = |n: Option<f64>| -> Px {
-        // Solid Color: only the inside of the set is drawn (Transparency flips the sides).
-        if palette == 3 {
-            let (r, g, bl) = hsl_to_rgb(hue, 1.0, 0.5);
-            return if n.is_none() != transparency { [r, g, bl, 1.0] } else { [0.0; 4] };
-        }
-        let Some(n) = n else {
-            return if transparent_inside { [0.0; 4] } else { [0.0, 0.0, 0.0, 1.0] };
-        };
-        let u = n / steps + cyc_off;
-        let band = (u.rem_euclid(1.0)) as f32;
-        let (r, g, bl) = match palette {
-            // Hue Wheel: the full hue circle at full saturation and brightness.
-            1 => hsl_to_rgb((hue + band).rem_euclid(1.0), 1.0, 0.5),
-            // Black And White: alternating bands.
-            2 => {
-                let v = if (u.floor() as i64).rem_euclid(2) == 0 { 0.0 } else { 1.0 };
-                (v, v, v)
-            }
-            // Lightness Gradient: black → hue → white, the hue moving 45° each cycle.
-            _ => hsl_to_rgb((hue + u.floor() as f32 * 0.125).rem_euclid(1.0), 0.85, band.clamp(0.0, 1.0)),
-        };
-        let mut c = [r, g, bl];
-        if edge && n.fract() < 0.12 {
-            c = [c[0] * 0.4 + 0.6, c[1] * 0.4 + 0.6, c[2] * 0.4 + 0.6];
-        }
-        [c[0], c[1], c[2], 1.0]
-    };
-    // First pass: one sample per pixel.
-    let mut first: Vec<Option<f64>> = vec![None; w * h];
-    first.par_chunks_mut(w.max(1)).enumerate().for_each(|(y, row)| {
-        for (x, v) in row.iter_mut().enumerate() {
-            *v = eval((x as f64 + 0.5 - off_x) * inv, (y as f64 + 0.5 - off_y) * inv);
-        }
-    });
-    let src = if overlay { Some(b.img.clone()) } else { None };
-    b.img.rows_mut().for_each(|(y, row)| {
-        for (x, px) in row.iter_mut().enumerate() {
-            let here = first[y * w + x];
-            let needs_ss = factor > 1
-                && (every || {
-                    let mut diff = false;
-                    for (dx, dy) in [(-1i64, 0i64), (1, 0), (0, -1), (0, 1)] {
-                        let (nx, ny) = (x as i64 + dx, y as i64 + dy);
-                        if nx < 0 || ny < 0 || nx >= w as i64 || ny >= h as i64 {
-                            continue;
-                        }
-                        let o = first[ny as usize * w + nx as usize];
-                        diff |= match (here, o) {
-                            (Some(a), Some(c)) => (a - c).abs() > steps * 0.25,
-                            (None, None) => false,
-                            _ => true,
-                        };
-                    }
-                    diff
-                });
-            let c = if needs_ss {
-                let mut acc = [0.0f32; 4];
-                for sy in 0..factor {
-                    for sx in 0..factor {
-                        let fx = x as f64 + (sx as f64 + 0.5) / factor as f64;
-                        let fy = y as f64 + (sy as f64 + 0.5) / factor as f64;
-                        let s = shade(eval((fx - off_x) * inv, (fy - off_y) * inv));
-                        let a = s[3];
-                        for k in 0..3 {
-                            acc[k] += s[k] * a;
-                        }
-                        acc[3] += a;
-                    }
-                }
-                let n = (factor * factor) as f32;
-                [acc[0] / n, acc[1] / n, acc[2] / n, acc[3] / n]
-            } else {
-                let s = shade(here);
-                [s[0] * s[3], s[1] * s[3], s[2] * s[3], s[3]]
-            };
-            *px = match &src {
-                Some(o) => over(o.data[y * w + x], c),
-                None => c,
-            };
-        }
-    });
-    b
-}
-
-// ---------------------------------------------------------------- Scribble
-
-/// Scan runs (start, end along direction `d`) of the fill region on the line `n·p = s`.
-#[allow(clippy::too_many_arguments)]
-fn scan_runs(polys: &[(Vec<[f64; 2]>, bool, bool)], fill: u32, ew: f64, d: [f64; 2], n: [f64; 2], s: f64, out: &mut Vec<(f64, f64)>) {
-    out.clear();
-    for (pts, _closed, inverted) in polys {
-        let m = pts.len();
-        if m < 2 {
-            continue;
-        }
-        // Crossings: (t along d, |sin| of crossing angle).
-        let mut xs: Vec<(f64, f64)> = Vec::new();
-        for i in 0..m {
-            let (a, b) = (pts[i], pts[(i + 1) % m]);
-            let (na, nb) = (a[0] * n[0] + a[1] * n[1] - s, b[0] * n[0] + b[1] * n[1] - s);
-            if (na > 0.0) == (nb > 0.0) {
-                continue;
-            }
-            let t = na / (na - nb);
-            let q = [a[0] + (b[0] - a[0]) * t, a[1] + (b[1] - a[1]) * t];
-            let (ex, ey) = (b[0] - a[0], b[1] - a[1]);
-            let el = (ex * ex + ey * ey).sqrt().max(1e-9);
-            let sin = ((ex * n[0] + ey * n[1]) / el).abs().max(0.2);
-            xs.push((q[0] * d[0] + q[1] * d[1], sin));
-        }
-        xs.sort_by(|a, b| a.0.total_cmp(&b.0));
-        // Signed area decides which side is "left".
-        let area: f64 = (0..m).map(|i| pts[i][0] * pts[(i + 1) % m][1] - pts[(i + 1) % m][0] * pts[i][1]).sum();
-        let left_is_inside = area < 0.0;
-        let mode = match fill {
-            4 => {
-                if left_is_inside {
-                    2
-                } else {
-                    3
-                }
-            }
-            5 => {
-                if left_is_inside {
-                    3
-                } else {
-                    2
-                }
-            }
-            f => f,
-        };
-        let mode = if *inverted && mode == 0 { 6 } else { mode };
-        for (k, &(t, sin)) in xs.iter().enumerate() {
-            let entering = k % 2 == 0;
-            let l = ew / sin;
-            match mode {
-                0 if entering && k + 1 < xs.len() => {
-                    out.push((t, xs[k + 1].0));
-                }
-                1 => out.push((t - l * 0.5, t + l * 0.5)),
-                2 => out.push(if entering { (t, t + l) } else { (t - l, t) }),
-                3 => out.push(if entering { (t - l, t) } else { (t, t + l) }),
-                _ => {}
-            }
-        }
-        if mode == 6 {
-            // Inverted Inside: outside of the polygon within the bounds.
-            let lo = pts.iter().map(|q| q[0] * d[0] + q[1] * d[1]).fold(f64::INFINITY, f64::min) - ew;
-            let hi = pts.iter().map(|q| q[0] * d[0] + q[1] * d[1]).fold(f64::NEG_INFINITY, f64::max) + ew;
-            let mut cur = lo;
-            for pair in xs.chunks(2) {
-                out.push((cur, pair[0].0));
-                cur = pair.get(1).map(|v| v.0).unwrap_or(hi);
-            }
-            out.push((cur, hi));
-        }
-    }
-    out.sort_by(|a, b| a.0.total_cmp(&b.0));
-    // Merge overlaps.
-    let mut merged: Vec<(f64, f64)> = Vec::with_capacity(out.len());
-    for &(a, b) in out.iter() {
-        if let Some(last) = merged.last_mut()
-            && a <= last.1
-        {
-            last.1 = last.1.max(b);
-            continue;
-        }
-        merged.push((a, b));
-    }
-    *out = merged;
-}
-
-/// End Cap and Join options (Scribble's Edge Options).
-const END_CAPS: [&str; 3] = ["Round", "Butt", "Projecting"];
-const JOINS: [&str; 3] = ["Round", "Miter", "Bevel"];
-
-/// Convex polygons whose union is the stroke of the polylines `lines` with half width `r`:
-/// one quad per segment, plus the joins (Round discs, Miter wedges up to `miter_limit` × the
-/// half width, Bevel triangles) and the caps (Round discs, Butt none, Projecting square ends).
-pub(crate) fn stroke_outline(lines: &[Vec<[f64; 2]>], r: f64, cap: u32, join: u32, miter_limit: f64) -> Vec<Vec<[f64; 2]>> {
-    let disc = |c: [f64; 2]| -> Vec<[f64; 2]> {
-        (0..16).map(|k| (k as f64 / 16.0 * std::f64::consts::TAU).sin_cos()).map(|(s, co)| [c[0] + co * r, c[1] + s * r]).collect()
-    };
-    let mut out = Vec::new();
-    for l in lines {
-        let pts: Vec<[f64; 2]> = l.iter().copied().fold(Vec::new(), |mut v, p| {
-            if v.last().is_none_or(|q: &[f64; 2]| (q[0] - p[0]).hypot(q[1] - p[1]) > 1e-9) {
-                v.push(p);
-            }
-            v
-        });
-        if pts.len() < 2 {
-            if let (Some(p), 0) = (pts.first(), cap) {
-                out.push(disc(*p));
-            }
-            continue;
-        }
-        let dir = |a: [f64; 2], b: [f64; 2]| {
-            let (dx, dy) = (b[0] - a[0], b[1] - a[1]);
-            let l = dx.hypot(dy).max(1e-12);
-            [dx / l, dy / l]
-        };
-        let n = pts.len();
-        for k in 0..n - 1 {
-            let (mut a, mut b) = (pts[k], pts[k + 1]);
-            let d = dir(a, b);
-            // Projecting caps extend the end segments by the half width.
-            if cap == 2 && k == 0 {
-                a = [a[0] - d[0] * r, a[1] - d[1] * r];
-            }
-            if cap == 2 && k == n - 2 {
-                b = [b[0] + d[0] * r, b[1] + d[1] * r];
-            }
-            let nn = [-d[1] * r, d[0] * r];
-            out.push(vec![[a[0] + nn[0], a[1] + nn[1]], [b[0] + nn[0], b[1] + nn[1]], [b[0] - nn[0], b[1] - nn[1]], [a[0] - nn[0], a[1] - nn[1]]]);
-        }
-        // Joins.
-        for k in 1..n - 1 {
-            let (p, d0, d1) = (pts[k], dir(pts[k - 1], pts[k]), dir(pts[k], pts[k + 1]));
-            let cross = d0[0] * d1[1] - d0[1] * d1[0];
-            if cross.abs() < 1e-9 && d0[0] * d1[0] + d0[1] * d1[1] > 0.0 {
-                continue;
-            }
-            if join == 0 {
-                out.push(disc(p));
-                continue;
-            }
-            // The outer side of the turn.
-            let s = if cross > 0.0 { -1.0 } else { 1.0 };
-            let o0 = [p[0] - d0[1] * r * s, p[1] + d0[0] * r * s];
-            let o1 = [p[0] - d1[1] * r * s, p[1] + d1[0] * r * s];
-            let bevel = vec![p, o0, o1];
-            if join == 1 {
-                // Miter point: where the two offset edges meet.
-                let bis = [d0[0] - d1[0], d0[1] - d1[1]];
-                let bl = bis[0].hypot(bis[1]);
-                let cos_half = ((1.0 + d0[0] * d1[0] + d0[1] * d1[1]) * 0.5).max(0.0).sqrt();
-                let len = if cos_half > 1e-6 { r / cos_half } else { f64::INFINITY };
-                if bl > 1e-9 && len <= miter_limit * r {
-                    let m = [p[0] + (o0[0] + o1[0] - 2.0 * p[0]) * 0.5, p[1] + (o0[1] + o1[1] - 2.0 * p[1]) * 0.5];
-                    let ml = (m[0] - p[0]).hypot(m[1] - p[1]).max(1e-12);
-                    let tip = [p[0] + (m[0] - p[0]) / ml * len, p[1] + (m[1] - p[1]) / ml * len];
-                    out.push(vec![p, o0, tip, o1]);
-                    continue;
-                }
-            }
-            out.push(bevel);
-        }
-        if cap == 0 {
-            out.push(disc(pts[0]));
-            out.push(disc(pts[n - 1]));
-        }
-    }
-    out
-}
-
-/// Coverage (union, 4×4 samples per pixel) of convex polygons on a `w`×`h` grid.
-pub(crate) fn raster_convex(w: usize, h: usize, polys: &[Vec<[f64; 2]>]) -> Plane {
-    let mut out = Plane::new(w, h);
-    let inside = |poly: &[[f64; 2]], x: f64, y: f64| {
-        let n = poly.len();
-        let mut sign = 0.0;
-        for i in 0..n {
-            let (a, b) = (poly[i], poly[(i + 1) % n]);
-            let c = (b[0] - a[0]) * (y - a[1]) - (b[1] - a[1]) * (x - a[0]);
-            if c.abs() < 1e-12 {
-                continue;
-            }
-            if sign == 0.0 {
-                sign = c.signum();
-            } else if c.signum() != sign {
-                return false;
-            }
-        }
-        true
-    };
-    for poly in polys {
-        if poly.len() < 3 {
-            continue;
-        }
-        let (mut x0, mut y0, mut x1, mut y1) = (f64::INFINITY, f64::INFINITY, f64::NEG_INFINITY, f64::NEG_INFINITY);
-        for p in poly {
-            x0 = x0.min(p[0]);
-            y0 = y0.min(p[1]);
-            x1 = x1.max(p[0]);
-            y1 = y1.max(p[1]);
-        }
-        let (xa, xb) = (x0.floor().max(0.0) as usize, (x1.ceil().max(0.0) as usize).min(w));
-        let (ya, yb) = (y0.floor().max(0.0) as usize, (y1.ceil().max(0.0) as usize).min(h));
-        for y in ya..yb {
-            for x in xa..xb {
-                let mut hit = 0;
-                for sy in 0..4 {
-                    for sx in 0..4 {
-                        if inside(poly, x as f64 + (sx as f64 + 0.5) / 4.0, y as f64 + (sy as f64 + 0.5) / 4.0) {
-                            hit += 1;
-                        }
-                    }
-                }
-                let v = &mut out.data[y * w + x];
-                *v = v.max(hit as f32 / 16.0);
-            }
-        }
-    }
-    out
-}
-
-fn scribble(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    match scribble_plan(ctx, &b) {
-        Some(plan) => draw_paint(&mut b, &plan),
-        None if scribble_style(ctx) == 1 => b.img = Image::new(b.img.width, b.img.height),
-        None => {}
-    }
-    b
-}
-
-fn scribble_plan(ctx: &EffectCtx, b: &Buf) -> Option<PaintPlan> {
-    let pr = ctx.params;
-    let which = pr.e("scribble");
-    let polys: Vec<_> = if which == 0 { mask_px(ctx, b, pr.f("mask").round().max(1.0) as usize).into_iter().collect() } else { all_masks_px(ctx, b) };
-    let polys: Vec<_> = polys.into_iter().filter(|p| p.0.len() >= 3).map(|(p, c, i)| (p, c, i && which == 2)).collect();
-    let style = scribble_style(ctx);
-    if polys.is_empty() {
-        return None;
-    }
-    let sc = b.scale;
-    let fill = pr.e("fillType");
-    let ew = pr.f("edgeOptions/edgeWidth").max(0.1) * sc;
-    let ang = pr.f("angle").to_radians();
-    let d = [ang.cos(), ang.sin()];
-    let n = [-d[1], d[0]];
-    let width = (pr.f("strokeWidth") * sc).max(0.1);
-    let curv = pr.f("strokeOptions/curviness") / 100.0;
-    let curv_var = pr.f("strokeOptions/curvinessVariation") / 100.0;
-    let spacing = (pr.f("strokeOptions/spacing") * sc).max(0.75).max(width * 0.25);
-    let spacing_var = pr.f("strokeOptions/spacingVariation") / 100.0;
-    let overlap = pr.f("strokeOptions/pathOverlap") / 100.0;
-    let overlap_var = pr.f("strokeOptions/pathOverlapVariation") / 100.0;
-    let start = pr.f("start").clamp(0.0, 100.0) / 100.0;
-    let end = pr.f("end").clamp(0.0, 100.0) / 100.0;
-    let sequential = pr.b("fillPathsSequentially");
-    let wiggle = pr.e("wiggleType");
-    let wps = pr.f("wigglesPerSecond").max(0.0);
-    let seed = pr.f("randomSeed") as i64 as u32 ^ ctx.seed;
-    let (step, frac) = match wiggle {
-        0 => (0u32, 0.0f32),
-        1 => ((ctx.time * wps).floor().max(0.0) as u32, 0.0),
-        _ => {
-            let u = (ctx.time * wps).max(0.0);
-            (u.floor() as u32, smoothstep(0.0, 1.0, u.fract() as f32))
-        }
-    };
-    let rnd = |i: u32, k: u32| {
-        let a = hash1(i, k.wrapping_mul(31).wrapping_add(step.wrapping_mul(7919)), seed) * 2.0 - 1.0;
-        if frac > 0.0 {
-            let c = hash1(i, k.wrapping_mul(31).wrapping_add((step + 1).wrapping_mul(7919)), seed) * 2.0 - 1.0;
-            a + (c - a) * frac
-        } else {
-            a
-        }
-    };
-    let groups: Vec<Vec<(Vec<[f64; 2]>, bool, bool)>> =
-        if which == 0 || sequential { vec![polys.clone()] } else { polys.iter().map(|p| vec![p.clone()]).collect() };
-    // Per group a zig-zag polyline (in buffer px).
-    let mut lines: Vec<Vec<Vec<[f64; 2]>>> = Vec::new();
-    let mut runs = Vec::new();
-    for (gi, g) in groups.iter().enumerate() {
-        let mut nmin = f64::INFINITY;
-        let mut nmax = f64::NEG_INFINITY;
-        for (pts, _, _) in g {
-            for q in pts {
-                let v = q[0] * n[0] + q[1] * n[1];
-                nmin = nmin.min(v);
-                nmax = nmax.max(v);
-            }
-        }
-        nmin -= ew;
-        nmax += ew;
-        // Chains of zig-zags: each run joins the nearest chain that ended on the previous
-        // scan line (so separate regions get separate strokes).
-        let mut chains: Vec<(Vec<[f64; 2]>, u32)> = Vec::new();
-        let mut s = nmin + spacing * 0.5;
-        let mut li = 0u32;
-        let reach = spacing * 3.0 + ew;
-        while s < nmax && li < 20_000 {
-            scan_runs(g, fill, ew, d, n, s, &mut runs);
-            for (ri, &(a, bb)) in runs.iter().enumerate() {
-                let k = (gi as u32) << 20 | ri as u32;
-                let ov = spacing * (overlap + overlap_var * rnd(li, k * 4) as f64 * 0.5).max(-0.45);
-                let ov2 = spacing * (overlap + overlap_var * rnd(li, k * 4 + 1) as f64 * 0.5).max(-0.45);
-                let (a, bb) = (a - ov, bb + ov2);
-                if bb <= a {
-                    continue;
-                }
-                let at = |t: f64| [d[0] * t + n[0] * s, d[1] * t + n[1] * s];
-                let (pa, pb) = (at(a), at(bb));
-                let dist = |p: [f64; 2], q: [f64; 2]| ((p[0] - q[0]).powi(2) + (p[1] - q[1]).powi(2)).sqrt();
-                let best = chains
-                    .iter()
-                    .enumerate()
-                    .filter(|(_, c)| li > 0 && c.1 == li - 1)
-                    .map(|(i, c)| {
-                        let last = *c.0.last().unwrap_or(&pa);
-                        (i, dist(last, pa).min(dist(last, pb)))
-                    })
-                    .filter(|&(_, dd)| dd < reach)
-                    .min_by(|x, y| x.1.total_cmp(&y.1));
-                match best {
-                    Some((ci, _)) => {
-                        let last = *chains[ci].0.last().unwrap_or(&pa);
-                        let (p0, p1, dir) = if dist(last, pa) <= dist(last, pb) { (pa, pb, -1.0) } else { (pb, pa, 1.0) };
-                        // Curved turn: an extra point pushed past the edge.
-                        let c = (curv + curv_var * rnd(li, k * 4 + 2) as f64 * 0.5).max(0.0);
-                        let mid = [(last[0] + p0[0]) * 0.5 + d[0] * dir * c * spacing, (last[1] + p0[1]) * 0.5 + d[1] * dir * c * spacing];
-                        let ch = &mut chains[ci];
-                        ch.0.extend([mid, p0, p1]);
-                        ch.1 = li;
-                    }
-                    None => chains.push((vec![pa, pb], li)),
-                }
-            }
-            s += spacing * (1.0 + spacing_var * rnd(li, 3) as f64 * 0.5).max(0.25);
-            li += 1;
-        }
-        lines.push(chains.into_iter().map(|(z, _)| if curv > 0.0 { chaikin(&z, 2) } else { z }).collect());
-    }
-    let r = width * 0.5;
-    // Start / End Apply To: all of a mask's strokes as one path, or each stroke on its own.
-    let each = pr.e("startEndApplyTo") == 1;
-    let mut parts: Vec<Vec<[f64; 2]>> = Vec::new();
-    for group in &lines {
-        let lens: Vec<f64> = group.iter().map(|l| poly_length(l, false)).collect();
-        let total: f64 = lens.iter().sum();
-        let (g0, g1) = (total * start, total * end);
-        let mut acc = 0.0;
-        for (l, len) in group.iter().zip(lens) {
-            let part =
-                if each { trim_poly(l, false, len * start, len * end) } else { trim_poly(l, false, (g0 - acc).clamp(0.0, len), (g1 - acc).clamp(0.0, len)) };
-            acc += len;
-            parts.push(part);
-        }
-    }
-    let cap = pr.e("edgeOptions/endCap");
-    let join = pr.e("edgeOptions/join");
-    let cov = if cap == 0 && join == 0 {
-        let mut segs = Vec::new();
-        for part in &parts {
-            poly_segs(part, false, r, 1.0, &mut segs);
-        }
-        Coverage::Segs { segs, hardness: 0.9 }
-    } else {
-        Coverage::Convex(stroke_outline(&parts, r, cap, join, pr.f("edgeOptions/miterLimit").max(1.0)))
-    };
-    Some(PaintPlan { cov, color: pr.color("color"), opacity: (pr.f("opacity") / 100.0) as f32, style })
-}
-
-// ---------------------------------------------------------------- Stroke
-
-fn stroke(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let plan = stroke_plan(ctx, &b);
-    draw_paint(&mut b, &plan);
-    b
-}
-
-fn stroke_plan(ctx: &EffectCtx, b: &Buf) -> PaintPlan {
-    let pr = ctx.params;
-    let all = pr.b("allMasks");
-    let polys: Vec<_> = if all { all_masks_px(ctx, b) } else { mask_px(ctx, b, pr.f("path").round() as usize).into_iter().collect() };
-    let style = pr.e("paintStyle");
-    let size = (pr.f("brushSize") * b.scale).max(0.1);
-    let r = size * 0.5;
-    let hard = pr.f("brushHardness") / 100.0;
-    let start = pr.f("start").clamp(0.0, 100.0) / 100.0;
-    let end = pr.f("end").clamp(0.0, 100.0) / 100.0;
-    let spacing = pr.f("spacing") / 100.0;
-    let sequential = pr.b("strokeSequentially");
-    let lens: Vec<f64> = polys.iter().map(|(p, c, _)| poly_length(p, *c)).collect();
-    let total: f64 = lens.iter().sum();
-    let mut segs = Vec::new();
-    let mut acc = 0.0;
-    for ((pts, closed, _), &len) in polys.iter().zip(&lens) {
-        let (s0, s1) = if all && sequential {
-            let (g0, g1) = (total * start, total * end);
-            ((g0 - acc).clamp(0.0, len), (g1 - acc).clamp(0.0, len))
-        } else {
-            (len * start, len * end)
-        };
-        acc += len;
-        if s1 <= s0 {
-            continue;
-        }
-        if spacing <= 0.5 {
-            let part = trim_poly(pts, *closed, s0, s1);
-            poly_segs(&part, false, r, 1.0, &mut segs);
-        } else {
-            let step = (size * spacing).max(0.5);
-            let mut s = s0;
-            while s <= s1 + 1e-9 && segs.len() < 200_000 {
-                let (q, _) = crate::util::poly_point_at(pts, *closed, s);
-                segs.push(Seg { a: q, b: q, r, v: 1.0 });
-                s += step;
-            }
-        }
-    }
-    PaintPlan { cov: Coverage::Segs { segs, hardness: hard }, color: pr.color("color"), opacity: (pr.f("opacity") / 100.0) as f32, style }
-}
-
-// ---------------------------------------------------------------- Vegas
-
-/// Marching-squares iso-contours of `pl` at `thr`, chained into polylines (closed flag).
-fn contours(pl: &Plane, thr: f32) -> Vec<(Vec<[f64; 2]>, bool)> {
-    use std::collections::HashMap;
-    let (w, h) = (pl.w, pl.h);
-    if w < 2 || h < 2 {
-        return Vec::new();
-    }
-    // Edge key: horizontal edge (x,y)-(x+1,y) = 2*(y*w+x), vertical (x,y)-(x,y+1) = 2*(y*w+x)+1.
-    let hk = |x: usize, y: usize| 2 * (y * w + x) as u64;
-    let vk = |x: usize, y: usize| 2 * (y * w + x) as u64 + 1;
-    let mut pos: HashMap<u64, [f64; 2]> = HashMap::new();
-    let mut adj: HashMap<u64, Vec<u64>> = HashMap::new();
-    let v = |x: usize, y: usize| pl.data[y * w + x];
-    let interp = |a: f32, b: f32| if (b - a).abs() > 1e-9 { ((thr - a) / (b - a)).clamp(0.0, 1.0) as f64 } else { 0.5 };
-    for y in 0..h - 1 {
-        for x in 0..w - 1 {
-            let (a, bb, c, d) = (v(x, y), v(x + 1, y), v(x + 1, y + 1), v(x, y + 1));
-            let idx = (a > thr) as u8 | ((bb > thr) as u8) << 1 | ((c > thr) as u8) << 2 | ((d > thr) as u8) << 3;
-            if idx == 0 || idx == 15 {
-                continue;
-            }
-            // Edge points (pixel centres at +0.5).
-            let top = (hk(x, y), [x as f64 + 0.5 + interp(a, bb), y as f64 + 0.5]);
-            let right = (vk(x + 1, y), [x as f64 + 1.5, y as f64 + 0.5 + interp(bb, c)]);
-            let bottom = (hk(x, y + 1), [x as f64 + 0.5 + interp(d, c), y as f64 + 1.5]);
-            let left = (vk(x, y), [x as f64 + 0.5, y as f64 + 0.5 + interp(a, d)]);
-            let pairs: &[(usize, usize)] = match idx {
-                1 | 14 => &[(3, 0)],
-                2 | 13 => &[(0, 1)],
-                3 | 12 => &[(3, 1)],
-                4 | 11 => &[(1, 2)],
-                5 => &[(3, 0), (1, 2)],
-                6 | 9 => &[(0, 2)],
-                7 | 8 => &[(3, 2)],
-                10 => &[(0, 1), (2, 3)],
-                _ => &[],
-            };
-            let e = [top, right, bottom, left];
-            for &(i, j) in pairs {
-                pos.insert(e[i].0, e[i].1);
-                pos.insert(e[j].0, e[j].1);
-                adj.entry(e[i].0).or_default().push(e[j].0);
-                adj.entry(e[j].0).or_default().push(e[i].0);
-            }
-        }
-    }
-    let mut keys: Vec<u64> = adj.keys().copied().collect();
-    keys.sort_unstable();
-    // Start open chains at endpoints (degree 1) first, then closed loops.
-    keys.sort_by_key(|k| adj[k].len() != 1);
-    let mut used: std::collections::HashSet<(u64, u64)> = std::collections::HashSet::new();
-    let mut out = Vec::new();
-    for &k0 in &keys {
-        for &first in &adj[&k0] {
-            if used.contains(&(k0.min(first), k0.max(first))) {
-                continue;
-            }
-            let mut chain = vec![pos[&k0]];
-            let (mut prev, mut cur) = (k0, first);
-            used.insert((prev.min(cur), prev.max(cur)));
-            let mut closed = false;
-            loop {
-                chain.push(pos[&cur]);
-                if cur == k0 {
-                    closed = true;
-                    chain.pop();
-                    break;
-                }
-                let next = adj[&cur].iter().copied().find(|&n| n != prev && !used.contains(&(cur.min(n), cur.max(n))));
-                match next {
-                    Some(n) => {
-                        used.insert((cur.min(n), cur.max(n)));
-                        prev = cur;
-                        cur = n;
-                    }
-                    None => break,
-                }
-            }
-            if chain.len() >= 2 {
-                out.push((chain, closed));
-            }
-        }
-    }
-    out
-}
-
-fn vegas(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let plan = vegas_plan(ctx, &b);
-    draw_paint(&mut b, &plan);
-    b
-}
-
-fn vegas_plan(ctx: &EffectCtx, b: &Buf) -> PaintPlan {
-    let pr = ctx.params;
-    let (w, h) = (b.img.width as usize, b.img.height as usize);
-    let sc = b.scale;
-    let paths: Vec<(Vec<[f64; 2]>, bool)> = if pr.e("stroke") == 1 {
-        mask_px(ctx, b, pr.f("path").round() as usize).map(|(p, c, _)| vec![(p, c)]).unwrap_or_default()
-    } else {
-        let src = layer_or_self(ctx, b, "inputLayer", true, pr.e("ifLayerSizesDiffer") == 1);
-        let ch = pr.e("channel");
-        let inv = pr.b("invertInput");
-        let mut pl = Plane::from_image(&src, |px| {
-            let (c, a) = unpremul(px);
-            let v = match ch {
-                1 => c[0],
-                2 => c[1],
-                3 => c[2],
-                4 => a,
-                _ => luminance(c[0], c[1], c[2]) * a,
-            };
-            if inv { 1.0 - v } else { v }
-        });
-        let blur = pr.f("preBlur") * sc;
-        if blur > 0.05 {
-            pl = gauss_plane(&pl, blur, blur);
-        }
-        let mut cs = contours(&pl, (pr.f("threshold") / 100.0) as f32);
-        // Simplify by tolerance (drop points closer than tol × size).
-        let tol = pr.f("tolerance").max(0.0) * (w.max(h) as f64) * 0.1;
-        if tol > 0.0 {
-            for (c, _) in cs.iter_mut() {
-                let mut keep: Vec<[f64; 2]> = Vec::with_capacity(c.len());
-                for &q in c.iter() {
-                    if keep.last().is_none_or(|l: &[f64; 2]| ((l[0] - q[0]).powi(2) + (l[1] - q[1]).powi(2)).sqrt() >= tol) {
-                        keep.push(q);
-                    }
-                }
-                *c = keep;
-            }
-        }
-        cs.sort_by(|a, b| poly_length(&b.0, b.1).total_cmp(&poly_length(&a.0, a.1)));
-        if pr.e("renderMode") == 1 {
-            let sel = (pr.f("selectedContour").round().max(1.0) as usize) - 1;
-            cs.into_iter().skip(sel).take(1).collect()
-        } else {
-            cs
-        }
-    };
-    let nseg = pr.f("segments").round().clamp(1.0, 1000.0) as usize;
-    // Shorter Contours Have Fewer Segments: segment count scales with contour length.
-    let fewer = pr.e("stroke") == 0 && pr.e("shorterContoursHave") == 1;
-    let longest = paths.iter().map(|(p, c)| poly_length(p, *c)).fold(0.0, f64::max);
-    let seg_len = pr.f("length").clamp(0.0, 1.0);
-    let bunched = pr.e("segmentDistribution") == 0;
-    let rot = pr.f("rotation") / 360.0;
-    let random_phase = pr.b("randomPhase");
-    let seed = pr.f("randomSeed") as i64 as u32 ^ ctx.seed;
-    let width = (pr.f("width") * sc).max(0.1);
-    let hard = pr.f("hardness").clamp(0.0, 1.0);
-    let (o0, om, o1, mp) = (pr.f("startOpacity") as f32, pr.f("midpointOpacity") as f32, pr.f("endOpacity") as f32, pr.f("midpointPosition").clamp(0.01, 0.99));
-    let mut segs = Vec::new();
-    for (ci, (pts, closed)) in paths.iter().enumerate() {
-        let len = poly_length(pts, *closed);
-        if len <= 0.0 {
-            continue;
-        }
-        let phase = rot + if random_phase { hash1(ci as u32, 1, seed) as f64 } else { 0.0 };
-        let nseg = if fewer && longest > 0.0 { ((nseg as f64 * len / longest).round() as usize).max(1) } else { nseg };
-        let each = len / nseg as f64 * seg_len;
-        for i in 0..nseg {
-            let base = if bunched { (i as f64 + (hash1(ci as u32, i as u32 + 7, seed) as f64 - 0.5) * 0.8) / nseg as f64 } else { i as f64 / nseg as f64 };
-            let s0 = (base + phase).rem_euclid(1.0) * len;
-            // Sub-sample the segment so opacity can ramp along it.
-            let sub = 12usize;
-            let mut prev: Option<[f64; 2]> = None;
-            for k in 0..=sub {
-                let f = k as f64 / sub as f64;
-                let mut s = s0 + each * f;
-                if *closed {
-                    s = s.rem_euclid(len);
-                } else if s > len {
-                    break;
-                }
-                let (q, _) = crate::util::poly_point_at(pts, *closed, s);
-                let op = if f < mp { o0 + (om - o0) * (f / mp) as f32 } else { om + (o1 - om) * ((f - mp) / (1.0 - mp)) as f32 };
-                if let Some(pv) = prev
-                    && ((pv[0] - q[0]).powi(2) + (pv[1] - q[1]).powi(2)) < (each * 0.5).powi(2) + 4.0
-                {
-                    segs.push(Seg { a: pv, b: q, r: width * 0.5, v: op.clamp(0.0, 1.0) });
-                }
-                prev = Some(q);
-            }
-        }
-    }
-    let style = match pr.e("blendMode") {
-        1 => 0,
-        2 => 3,
-        3 => 2,
-        _ => 1,
-    };
-    PaintPlan { cov: Coverage::Segs { segs, hardness: hard }, color: pr.color("color"), opacity: 1.0, style }
-}
-
-// ---------------------------------------------------------------- Write-on / Glue Gun
-
-/// Write-on draws a stroke along the animated Brush Position, as in After Effects: a dab every
-/// Brush Spacing seconds from the layer's start up to now, each one lasting Stroke Length
-/// seconds (0: for ever). The dabs' positions come from the host's parameters at their times;
-/// with Paint Time Properties ▸ Opacity or Brush Time Properties ▸ Size each dab keeps its own
-/// opacity or size, else the current ones apply to every dab. (Colour and hardness are one per
-/// stroke: the current ones.) Without a host (or dabs) the current dab draws. Deterministic.
-fn write_on(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let plan = write_on_plan(ctx, &b);
-    draw_paint(&mut b, &plan);
-    b
-}
-
-/// The most dabs one Write-on frame draws; longer strokes lay them further apart, joined.
-const WRITE_ON_MAX_DABS: i64 = 4096;
-
-fn write_on_plan(ctx: &EffectCtx, b: &Buf) -> PaintPlan {
-    let pr = ctx.params;
-    let own_opacity = pr.e("paintTimeProperties") == 1;
-    let own_size = matches!(pr.e("brushTimeProperties"), 1 | 3);
-    let opacity = |p: &Params| (p.f("brushOpacity") / 100.0).clamp(0.0, 1.0) as f32;
-    let radius = |p: &Params| (p.f("brushSize") * b.scale * 0.5).max(0.05);
-    let dab = |p: &Params| {
-        let q = b.to_px(p.v2("brushPosition"));
-        ([q.0, q.1], radius(if own_size { p } else { pr }), if own_opacity { opacity(p) } else { 1.0 })
-    };
-    let mut segs = vec![];
-    let t = ctx.time;
-    let spacing = pr.f("brushSpacing").max(0.001);
-    let life = pr.f("strokeLength").max(0.0);
-    if let Some(host) = ctx.env.host
-        && t.is_finite()
-        && t >= 0.0
-    {
-        let start = if life > 0.0 { (t - life).max(0.0) } else { 0.0 };
-        let k0 = (start / spacing - 1e-9).ceil().max(0.0) as i64;
-        let k1 = (t / spacing + 1e-9).floor().max(0.0) as i64;
-        let n = k1.saturating_sub(k0).saturating_add(1);
-        let stride = (n / WRITE_ON_MAX_DABS).saturating_add(1).max(1);
-        let mut prev: Option<[f64; 2]> = None;
-        let mut k = k0;
-        while k <= k1 {
-            let tk = k as f64 * spacing;
-            let at = if (tk - t).abs() < 1e-9 { Some(dab(pr)) } else { host.params_at(tk).map(|p| dab(&p)) };
-            if let Some((q, r, v)) = at {
-                // Dabs laid further apart than the brush spacing are joined into a line.
-                let a = if stride > 1 { prev.unwrap_or(q) } else { q };
-                segs.push(Seg { a, b: q, r, v });
-                prev = Some(q);
-            }
-            k = k.saturating_add(stride);
-        }
-    }
-    if segs.is_empty() {
-        let (q, r, v) = dab(pr);
-        segs.push(Seg { a: q, b: q, r, v });
-    }
-    PaintPlan {
-        cov: Coverage::Segs { segs, hardness: pr.f("brushHardness") / 100.0 },
-        color: pr.color("color"),
-        opacity: if own_opacity { 1.0 } else { opacity(pr) },
-        style: pr.e("paintStyle"),
-    }
-}
-
-fn glue_gun(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let pr = ctx.params;
-    let q = b.to_px(pr.v2("brushPosition"));
-    let rad = (pr.f("strokeWidth") * b.scale * 0.5).max(0.5);
-    let density = pr.f("density").max(0.0);
-    let refl = pr.f("reflection").to_radians();
-    let strength = (pr.f("strength") / 100.0) as f32;
-    let glue_only = pr.e("style") == 1;
-    let src = b.img.clone();
-    let light = [refl.cos() * 0.6, -refl.sin() * 0.6, 0.53];
-    let beads = (density.round() as usize).clamp(1, 32);
-    let seed = ctx.seed;
-    let centers: Vec<([f64; 2], f64)> = (0..beads)
-        .map(|i| {
-            let a = hash1(i as u32, 1, seed) as f64 * 2.0 * PI;
-            let d = if i == 0 { 0.0 } else { hash1(i as u32, 2, seed) as f64 * rad * 0.35 };
-            ([q.0 + a.cos() * d, q.1 + a.sin() * d], rad * (0.75 + 0.25 * hash1(i as u32, 3, seed) as f64))
-        })
-        .collect();
-    b.img.rows_mut().for_each(|(y, row)| {
-        for (x, px) in row.iter_mut().enumerate() {
-            let (fx, fy) = (x as f64 + 0.5, y as f64 + 0.5);
-            // Height field: union of hemispheres.
-            let mut best = (0.0f64, [0.0f64; 2], 1.0f64);
-            for &(c, r) in &centers {
-                let (dx, dy) = ((fx - c[0]) / r, (fy - c[1]) / r);
-                let d2 = dx * dx + dy * dy;
-                if d2 < 1.0 {
-                    let hgt = (1.0 - d2).sqrt();
-                    if hgt > best.0 {
-                        best = (hgt, [dx, dy], r);
-                    }
-                }
-            }
-            if best.0 <= 0.0 {
-                if glue_only {
-                    *px = [0.0; 4];
-                }
-                continue;
-            }
-            let nrm = [best.1[0], best.1[1], best.0];
-            let ndl = (nrm[0] * light[0] + nrm[1] * light[1] + nrm[2] * light[2]).max(0.0);
-            let spec = ndl.powi(24) as f32;
-            // Refraction: look through the bead.
-            let s = src.sample_bilinear_clamped(fx - nrm[0] * best.2 * 0.5 * strength as f64, fy - nrm[1] * best.2 * 0.5 * strength as f64);
-            let edge = smoothstep(0.0, 0.15, best.0 as f32);
-            let shade = 0.65 + 0.35 * ndl as f32;
-            let g = [s[0] * shade + spec, s[1] * shade + spec, s[2] * shade + spec, s[3].max(0.6)];
-            let gp = [g[0].min(g[3] + spec), g[1].min(g[3] + spec), g[2].min(g[3] + spec), g[3].min(1.0)];
-            let base = if glue_only { [0.0; 4] } else { *px };
-            *px = crate::util::lerp4(base, gp, edge * strength.clamp(0.0, 1.0).max(0.3));
-            px[3] = px[3].clamp(0.0, 1.0);
-        }
-    });
-    b
-}
-
-// ---------------------------------------------------------------- Paint Bucket
-
-/// Paint Bucket's filled region (1 inside) on `b`: the flood fill from the Fill Point over the
-/// layer's pixels (shared with the GPU compositor, which reads the layer back for it).
-pub fn paint_bucket_region(ctx: &EffectCtx, b: &Buf) -> Plane {
-    let pr = ctx.params;
-    let (w, h) = (b.img.width as usize, b.img.height as usize);
-    let fp = b.to_px(pr.v2("fillPoint"));
-    let (sx, sy) = (fp.0.floor() as i64, fp.1.floor() as i64);
-    let sel = pr.e("fillSelector");
-    let tol = (pr.f("tolerance") / 255.0) as f32;
-    let key = |p: Px| -> [f32; 4] {
-        let (c, a) = unpremul(p);
-        match sel {
-            1 => [c[0], c[1], c[2], 0.0],
-            2 => [0.0, 0.0, 0.0, if a <= 1e-3 { 0.0 } else { 1.0 }],
-            3 | 4 => [0.0, 0.0, 0.0, a],
-            _ => p,
-        }
-    };
-    let mut region = Plane::new(w, h);
-    if sx >= 0 && sy >= 0 && (sx as usize) < w && (sy as usize) < h {
-        let seed = key(b.img.data[sy as usize * w + sx as usize]);
-        let within = |i: usize| {
-            let k = key(b.img.data[i]);
-            if sel == 2 {
-                return k[3] == seed[3];
-            }
-            (0..4).all(|j| (k[j] - seed[j]).abs() <= tol + 1e-6)
-        };
-        let mut seen = vec![false; w * h];
-        let mut stack = vec![(sx as usize, sy as usize)];
-        while let Some((x, y)) = stack.pop() {
-            let row = y * w;
-            if seen[row + x] || !within(row + x) {
-                continue;
-            }
-            let mut l = x;
-            while l > 0 && !seen[row + l - 1] && within(row + l - 1) {
-                l -= 1;
-            }
-            let mut r = x;
-            while r + 1 < w && !seen[row + r + 1] && within(row + r + 1) {
-                r += 1;
-            }
-            for i in l..=r {
-                seen[row + i] = true;
-                region.data[row + i] = 1.0;
-                if y > 0 && !seen[row - w + i] {
-                    stack.push((i, y - 1));
-                }
-                if y + 1 < h && !seen[row + w + i] {
-                    stack.push((i, y + 1));
-                }
-            }
-        }
-    }
-    region
-}
-
-fn paint_bucket(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let pr = ctx.params;
-    let (w, h) = (b.img.width as usize, b.img.height as usize);
-    if w == 0 || h == 0 {
-        return b;
-    }
-    let region = paint_bucket_region(ctx, &b);
-    if pr.b("viewThreshold") {
-        b.img.data.par_iter_mut().zip(region.data.par_iter()).for_each(|(px, &v)| *px = [v, v, v, 1.0]);
-        return b;
-    }
-    let sc = b.scale;
-    let mut cov = match pr.e("stroke") {
-        1 => {
-            let s = pr.f("featherSoftness") * sc * 0.5;
-            if s > 0.05 { gauss_plane(&region, s, s) } else { region.clone() }
-        }
-        2 => morph_frac(&region, pr.f("spreadRadius") * sc, true),
-        3 => morph_frac(&region, pr.f("spreadRadius") * sc, false),
-        4 => {
-            let r = pr.f("strokeWidth") * sc;
-            let out = morph_frac(&region, r * 0.5, true);
-            let inn = morph_frac(&region, r * 0.5, false);
-            out.zip_map(&inn, |a, b| (a - b).max(0.0))
-        }
-        _ => gauss_plane(&region, 0.5, 0.5),
-    };
-    if pr.e("stroke") == 0 {
-        // Antialias: keep the hard interior, soften only the boundary.
-        cov = cov.zip_map(&region, |a, r| if r > 0.0 { a.max(0.5) } else { a });
-    }
-    let color = pr.color("color");
-    let op = (pr.f("opacity") / 100.0) as f32;
-    let mode = pr.e("blendingMode");
-    b.img.data.par_iter_mut().zip(cov.data.par_iter()).for_each(|(px, &c)| {
-        let k = (c * op * color[3]).clamp(0.0, 1.0);
-        if k <= 0.0 {
-            if mode == 9 {
-                *px = [0.0; 4];
-            }
-            return;
-        }
-        let (dc, da) = unpremul(*px);
-        let fc = [color[0], color[1], color[2]];
-        let mixed = match mode {
-            1 => [dc[0] + fc[0], dc[1] + fc[1], dc[2] + fc[2]],
-            2 => [dc[0] * fc[0], dc[1] * fc[1], dc[2] * fc[2]],
-            3 => [1.0 - (1.0 - dc[0]) * (1.0 - fc[0]), 1.0 - (1.0 - dc[1]) * (1.0 - fc[1]), 1.0 - (1.0 - dc[2]) * (1.0 - fc[2])],
-            4..=7 => {
-                let (dh, ds, dl) = rgb_to_hsl(dc[0], dc[1], dc[2]);
-                let (fh, fs, fl) = rgb_to_hsl(fc[0], fc[1], fc[2]);
-                let (r, g, bl) = match mode {
-                    4 => hsl_to_rgb(fh, ds, dl),
-                    5 => hsl_to_rgb(dh, fs, dl),
-                    6 => hsl_to_rgb(fh, fs, dl),
-                    _ => hsl_to_rgb(dh, ds, fl),
-                };
-                [r, g, bl]
-            }
-            _ => fc,
-        };
-        *px = match mode {
-            8 => over(premul(fc, k), *px),
-            9 => premul(fc, k),
-            0 => over(*px, premul(fc, k)),
-            _ => {
-                if da <= 1e-6 {
-                    return;
-                }
-                let c3 = crate::util::lerp3(dc, mixed, k);
-                premul(c3, da)
-            }
-        };
-    });
-    b
-}
-
-// ---------------------------------------------------------------- Eyedropper Fill
-
-fn eyedropper_fill(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let pr = ctx.params;
-    let fill = eyedropper_color(ctx, &b);
-    let keep_alpha = pr.b("maintainOriginalAlpha");
-    let blend = (pr.f("blendWithOriginal") / 100.0) as f32;
-    b.img.data.par_iter_mut().for_each(|px| {
-        let a = if keep_alpha { px[3] } else { fill[3] };
-        let f = premul([fill[0], fill[1], fill[2]], a);
-        *px = crate::util::lerp4(f, *px, blend);
-    });
-    b
-}
-
-/// Eyedropper Fill's sampled colour (straight RGB, alpha) from the layer's pixels (shared with
-/// the GPU compositor, which reads the layer back for it).
-pub fn eyedropper_color(ctx: &EffectCtx, b: &Buf) -> Px {
-    let pr = ctx.params;
-    let (w, h) = (b.img.width as i64, b.img.height as i64);
-    let c = b.to_px(pr.v2("samplePoint"));
-    let r = (pr.f("sampleRadius") * b.scale).max(0.0);
-    let mode = pr.e("averagePixelColors");
-    let (cx, cy) = (c.0.floor() as i64, c.1.floor() as i64);
-    let ri = r.ceil() as i64;
-    let mut acc = [0.0f64; 4];
-    let mut n = 0.0f64;
-    for y in (cy - ri).max(0)..=(cy + ri).min(h - 1) {
-        for x in (cx - ri).max(0)..=(cx + ri).min(w - 1) {
-            if ((x - cx).pow(2) + (y - cy).pow(2)) as f64 > r * r + 0.5 {
-                continue;
-            }
-            let px = b.img.data[(y * w + x) as usize];
-            match mode {
-                0 => {
-                    if px[3] > 1e-4 {
-                        let (s, _) = unpremul(px);
-                        for k in 0..3 {
-                            acc[k] += s[k] as f64;
-                        }
-                        acc[3] += 1.0;
-                        n += 1.0;
-                    }
-                }
-                1 => {
-                    let (s, _) = unpremul(px);
-                    for k in 0..3 {
-                        acc[k] += s[k] as f64;
-                    }
-                    acc[3] += 1.0;
-                    n += 1.0;
-                }
-                2 => {
-                    for k in 0..3 {
-                        acc[k] += px[k] as f64;
-                    }
-                    acc[3] += 1.0;
-                    n += 1.0;
-                }
-                _ => {
-                    for k in 0..4 {
-                        acc[k] += px[k] as f64;
-                    }
-                    n += 1.0;
-                }
-            }
-        }
-    }
-    if n > 0.0 {
-        if mode == 3 {
-            let a = (acc[3] / n) as f32;
-            let s = if a > 1e-6 { [(acc[0] / n) as f32 / a, (acc[1] / n) as f32 / a, (acc[2] / n) as f32 / a] } else { [0.0; 3] };
-            [s[0], s[1], s[2], a]
-        } else {
-            [(acc[0] / n) as f32, (acc[1] / n) as f32, (acc[2] / n) as f32, 1.0]
-        }
-    } else {
-        [0.0, 0.0, 0.0, 0.0]
-    }
-}
-
-// ---------------------------------------------------------------- CC Threads
-
-fn threads(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let pr = ctx.params;
-    let sc = b.scale;
-    let tw = (pr.f("width") * sc).max(1.0);
-    let th = (pr.f("height") * sc).max(1.0);
-    let overlaps = pr.f("overlaps").round().clamp(1.0, 20.0) as i64;
-    let ang = pr.f("direction").to_radians();
-    let (sn, cs) = ang.sin_cos();
-    let c = b.to_px(pr.v2("center"));
-    let coverage = (pr.f("coverage") / 100.0).clamp(0.0, 1.0);
-    let shadow = (pr.f("shadowing") / 100.0) as f32;
-    let texture = (pr.f("texture") / 100.0) as f32;
-    let src = b.img.clone();
-    let to_px = |u: f64, v: f64| (c.0 + u * cs - v * sn, c.1 + u * sn + v * cs);
-    b.img.rows_mut().for_each(|(y, row)| {
-        for (x, px) in row.iter_mut().enumerate() {
-            let (dx, dy) = (x as f64 + 0.5 - c.0, y as f64 + 0.5 - c.1);
-            let u = dx * cs + dy * sn;
-            let v = -dx * sn + dy * cs;
-            let (ci, cj) = ((u / tw).floor() as i64, (v / th).floor() as i64);
-            let (fu, fv) = (u / tw - ci as f64, v / th - cj as f64);
-            // Horizontal thread j occupies the band |fv-0.5| < coverage/2; vertical thread i the
-            // band |fu-0.5| < coverage/2.
-            let in_h = (fv - 0.5).abs() < coverage * 0.5;
-            let in_v = (fu - 0.5).abs() < coverage * 0.5;
-            // Twill: horizontal is on top when (i + j) mod (2·overlaps) < overlaps.
-            let h_top = (ci + cj).rem_euclid(2 * overlaps) < overlaps;
-            let which = match (in_h, in_v) {
-                (true, true) => Some(h_top),
-                (true, false) => Some(true),
-                (false, true) => Some(false),
-                _ => None,
-            };
-            let Some(horizontal) = which else {
-                *px = [0.0; 4];
-                continue;
-            };
-            // Thread colour: the source sampled along the thread centre line.
-            let (sx, sy) = if horizontal { to_px(u, (cj as f64 + 0.5) * th) } else { to_px((ci as f64 + 0.5) * tw, v) };
-            let s = src.sample_bilinear_clamped(sx, sy);
-            // Round profile across the thread + darkening where it dives under its neighbour.
-            let across = if horizontal { (fv - 0.5) / (coverage * 0.5).max(1e-6) } else { (fu - 0.5) / (coverage * 0.5).max(1e-6) };
-            let along = if horizontal { fu } else { fv };
-            let profile = (1.0 - across * across).max(0.0).sqrt() as f32;
-            let dive = 1.0 - (along - 0.5).abs() as f32 * 2.0;
-            let shade = 1.0 - shadow * (1.0 - profile) * 0.8 - shadow * 0.25 * (1.0 - dive) * if horizontal == h_top { 0.0 } else { 1.0 };
-            let fib =
-                if texture > 0.0 { 1.0 - texture * 0.3 * hash1((along * 64.0) as u32, (across * 8.0 + 8.0) as u32, ci as u32 ^ (cj as u32) << 8) } else { 1.0 };
-            let k = (shade * fib).max(0.0);
-            *px = [s[0] * k, s[1] * k, s[2] * k, s[3]];
-        }
-    });
-    b
-}
-
-// ---------------------------------------------------------------- Audio Spectrum / Waveform
-
-/// In-place iterative radix-2 FFT (`re`, `im` lengths a power of two).
-pub(crate) fn fft(re: &mut [f64], im: &mut [f64]) {
-    let n = re.len();
-    if n < 2 {
-        return;
-    }
-    let mut j = 0;
-    for i in 1..n {
-        let mut bit = n >> 1;
-        while j & bit != 0 {
-            j ^= bit;
-            bit >>= 1;
-        }
-        j |= bit;
-        if i < j {
-            re.swap(i, j);
-            im.swap(i, j);
-        }
-    }
-    let mut len = 2;
-    while len <= n {
-        let ang = -2.0 * PI / len as f64;
-        let (ws, wc) = ang.sin_cos();
-        for start in (0..n).step_by(len) {
-            let (mut cr, mut ci) = (1.0, 0.0);
-            for k in 0..len / 2 {
-                let (a, bb) = (start + k, start + k + len / 2);
-                let tr = re[bb] * cr - im[bb] * ci;
-                let ti = re[bb] * ci + im[bb] * cr;
-                re[bb] = re[a] - tr;
-                im[bb] = im[a] - ti;
-                re[a] += tr;
-                im[a] += ti;
-                let ncr = cr * wc - ci * ws;
-                ci = cr * ws + ci * wc;
-                cr = ncr;
-            }
-        }
-        len <<= 1;
-    }
-}
-
-const AUDIO_RATE: u32 = 48_000;
-
-/// Fetch mono (or one channel) samples of the audio layer around the current time.
-fn audio_window(ctx: &EffectCtx, dur_ms: f64, offset_ms: f64, channel: u32) -> Option<Vec<f64>> {
-    let id = ctx.params.get("audioLayer")?.as_layer()?;
-    let host = ctx.env.host?;
-    let dur = (dur_ms / 1000.0).max(0.001);
-    let frames = ((dur * AUDIO_RATE as f64) as usize).clamp(16, 1 << 16);
-    let start = ctx.env.comp_time + offset_ms / 1000.0 - dur * 0.5;
-    let s = host.audio(id, start, frames, AUDIO_RATE)?;
-    Some(
-        (0..frames)
-            .map(|i| {
-                let (l, r) = (*s.get(2 * i).unwrap_or(&0.0) as f64, *s.get(2 * i + 1).unwrap_or(&0.0) as f64);
-                match channel {
-                    1 => l,
-                    2 => r,
-                    _ => (l + r) * 0.5,
-                }
-            })
-            .collect(),
-    )
-}
-
-/// The drawing baseline: a polyline in buffer px (mask path or start→end line), sampled at
-/// parameter u∈[0,1] → (point, unit normal).
-struct Baseline {
-    pts: Vec<[f64; 2]>,
-    closed: bool,
-    len: f64,
-    polar: bool,
-    center: [f64; 2],
-    radius: f64,
-}
-
-impl Baseline {
-    fn new(ctx: &EffectCtx, b: &Buf) -> Baseline {
-        let pr = ctx.params;
-        let polar = pr.b("usePolarPath");
-        let (pts, closed) = match mask_px(ctx, b, pr.f("path").round() as usize) {
-            Some((p, c, _)) if !polar => (p, c),
-            _ => {
-                let s = b.to_px(pr.v2("startPoint"));
-                let e = b.to_px(pr.v2("endPoint"));
-                (vec![[s.0, s.1], [e.0, e.1]], false)
-            }
-        };
-        let len = poly_length(&pts, closed);
-        let center = pts[0];
-        let radius = if pts.len() > 1 { ((pts[1][0] - pts[0][0]).powi(2) + (pts[1][1] - pts[0][1]).powi(2)).sqrt() } else { 1.0 };
-        Baseline { pts, closed, len, polar, center, radius }
-    }
-    fn at(&self, u: f64) -> ([f64; 2], [f64; 2]) {
-        if self.polar {
-            let a = u * 2.0 * PI - PI * 0.5;
-            let (s, c) = a.sin_cos();
-            return ([self.center[0] + c * self.radius * 0.5, self.center[1] + s * self.radius * 0.5], [c, s]);
-        }
-        let (q, d) = crate::util::poly_point_at(&self.pts, self.closed, u * self.len);
-        (q, [d[1], -d[0]])
-    }
-}
-
-/// Draw line/dot marks with core (inside colour) and soft halo (outside colour).
-fn draw_marks(b: &mut Buf, segs_core: &[Seg], thickness: f64, softness: f64, inside: [f32; 4], outside: [f32; 4], composite: bool) {
-    let (w, h) = (b.img.width as usize, b.img.height as usize);
-    let core = raster_segs(w, h, segs_core, 1.0);
-    let halo_segs: Vec<Seg> = segs_core.iter().map(|s| Seg { r: s.r + thickness * softness.max(0.0) + 0.5, ..*s }).collect();
-    let halo = if softness > 0.0 { raster_segs(w, h, &halo_segs, 0.0) } else { core.clone() };
-    b.img.data.par_iter_mut().enumerate().for_each(|(i, px)| {
-        let (c, hl) = (core.data[i], halo.data[i]);
-        let a = c.max(hl);
-        let base = if composite { *px } else { [0.0; 4] };
-        if a <= 0.0 {
-            *px = base;
-            return;
-        }
-        let t = if a > 0.0 { c / a } else { 0.0 };
-        let col = crate::util::lerp3([outside[0], outside[1], outside[2]], [inside[0], inside[1], inside[2]], t);
-        *px = over(base, premul(col, a));
-    });
-}
-
-/// Audio Spectrum / Audio Waveform, shared with the GPU compositor (effectcraft-gpu `fx_gen2`):
-/// the marks (the audio analysis runs on the CPU) and how `draw_marks` colours them.
-#[derive(Clone, Debug)]
-pub struct MarksPlan {
-    pub segs: Vec<Seg>,
-    pub thickness: f64,
-    pub softness: f64,
-    pub inside: [f32; 4],
-    pub outside: [f32; 4],
-    pub composite: bool,
-}
-
-/// [`MarksPlan`] of Audio Spectrum or Audio Waveform on `b`'s geometry (`None` = no audio:
-/// the layer passes through).
-pub fn marks_plan(id: &str, ctx: &EffectCtx, b: &Buf) -> Option<MarksPlan> {
-    match id {
-        "ec.generate.audiospectrum" => spectrum_plan(ctx, b),
-        "ec.generate.audiowaveform" => waveform_plan(ctx, b),
-        _ => None,
-    }
-}
-
-fn marks(ctx: &EffectCtx, segs: Vec<Seg>, thick: f64, soft: f64) -> MarksPlan {
-    let pr = ctx.params;
-    MarksPlan {
-        segs,
-        thickness: thick,
-        softness: soft * 2.0,
-        inside: pr.color("insideColor"),
-        outside: pr.color("outsideColor"),
-        composite: pr.b("compositeOnOriginal"),
-    }
-}
-
-fn audio_spectrum(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    if let Some(m) = spectrum_plan(ctx, &b) {
-        draw_marks(&mut b, &m.segs, m.thickness, m.softness, m.inside, m.outside, m.composite);
-    }
-    b
-}
-
-fn audio_waveform(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    if let Some(m) = waveform_plan(ctx, &b) {
-        draw_marks(&mut b, &m.segs, m.thickness, m.softness, m.inside, m.outside, m.composite);
-    }
-    b
-}
-
-fn compute_fft_mags(samples: &[f64]) -> (usize, f64, Vec<f64>) {
-    let m = samples.len();
-    let n = m.next_power_of_two().max(64);
-    let mut re = vec![0.0; n];
-    let mut im = vec![0.0; n];
-    let denom = (m.max(2) - 1) as f64;
-    for (i, s) in samples.iter().enumerate() {
-        let w = 0.5 - 0.5 * (2.0 * PI * i as f64 / denom).cos();
-        if let Some(r) = re.get_mut(i) {
-            *r = s * w;
-        }
-    }
-    fft(&mut re, &mut im);
-    let hz_per_bin = AUDIO_RATE as f64 / n as f64;
-    let scale = 4.0 / m.max(1) as f64;
-    let num_bins = n / 2 + 1;
-    let mut mags = Vec::with_capacity(num_bins);
-    for k in 0..num_bins {
-        let r = re.get(k).copied().unwrap_or(0.0);
-        let im_val = im.get(k).copied().unwrap_or(0.0);
-        let mag = (r * r + im_val * im_val).sqrt() * scale;
-        mags.push(mag);
-    }
-    (n, hz_per_bin, mags)
-}
-
-fn spectrum_plan(ctx: &EffectCtx, b: &Buf) -> Option<MarksPlan> {
-    let pr = ctx.params;
-    let samples = audio_window(ctx, pr.f("audioDuration"), pr.f("audioOffset"), 0)?;
-    let (_n, hz_per_bin, mags) = compute_fft_mags(&samples);
-
-    let bands = pr.f("frequencyBands").round().clamp(1.0, 4096.0) as usize;
-    let f0 = pr.f("startFrequency").max(0.0);
-    let f1 = pr.f("endFrequency").max(f0 + 1.0);
-    let max_bin = mags.len().saturating_sub(1);
-
-    let get_band_mag = |fc: f64| -> f64 {
-        if mags.is_empty() || hz_per_bin <= 0.0 {
-            return 0.0;
-        }
-        let k_float = (fc / hz_per_bin).clamp(0.0, max_bin as f64);
-        let k0 = (k_float.floor() as usize).min(max_bin.saturating_sub(1));
-        let k1 = (k0 + 1).min(max_bin);
-        let frac = (k_float - k0 as f64).clamp(0.0, 1.0);
-        let m0 = mags.get(k0).copied().unwrap_or(0.0);
-        let m1 = mags.get(k1).copied().unwrap_or(0.0);
-        m0 * (1.0 - frac) + m1 * frac
-    };
-
-    let max_h = pr.f("maximumHeight") * b.scale;
-    let thick = (pr.f("thickness") * b.scale).max(0.1);
-    let soft = pr.f("softness") / 100.0;
-    let disp = pr.e("displayOptions");
-    let side = pr.e("sideOptions");
-    let base = Baseline::new(ctx, b);
-    let mut tops = Vec::with_capacity(bands);
-    let mut segs = Vec::new();
-    for i in 0..bands {
-        let u = if bands > 1 { i as f64 / (bands - 1) as f64 } else { 0.5 };
-        let fc = f0 + (f1 - f0) * u;
-        let v = get_band_mag(fc);
-        let hgt = if (v * max_h).is_finite() { (v * max_h).clamp(0.0, max_h.max(0.0)) } else { 0.0 };
-        let (q, nrm) = base.at(u);
-        let (ua, ub) = match side {
-            0 => (0.0, hgt),
-            1 => (-hgt, 0.0),
-            _ => (-hgt, hgt),
-        };
-        let pa = [q[0] + nrm[0] * ua, q[1] + nrm[1] * ua];
-        let pb = [q[0] + nrm[0] * ub, q[1] + nrm[1] * ub];
-        match disp {
-            0 => segs.push(Seg { a: pa, b: pb, r: thick * 0.5, v: 1.0 }),
-            _ => tops.push((pa, pb)),
-        }
-    }
-    if disp == 1 {
-        for w2 in tops.windows(2) {
-            segs.push(Seg { a: w2[0].1, b: w2[1].1, r: thick * 0.5, v: 1.0 });
-            if side == 2 {
-                segs.push(Seg { a: w2[0].0, b: w2[1].0, r: thick * 0.5, v: 1.0 });
-            }
-        }
-    } else if disp == 2 {
-        for &(pa, pb) in &tops {
-            segs.push(Seg { a: pb, b: pb, r: thick * 0.5, v: 1.0 });
-            if side == 2 {
-                segs.push(Seg { a: pa, b: pa, r: thick * 0.5, v: 1.0 });
-            }
-        }
-    }
-    Some(marks(ctx, segs, thick, soft))
-}
-
-fn waveform_plan(ctx: &EffectCtx, b: &Buf) -> Option<MarksPlan> {
-    let pr = ctx.params;
-    let samples = audio_window(ctx, pr.f("audioDuration"), pr.f("audioOffset"), pr.e("waveformOptions"))?;
-    let count = pr.f("displayedSamples").round().clamp(2.0, 4096.0) as usize;
-    let max_h = pr.f("maximumHeight") * b.scale;
-    let thick = (pr.f("thickness") * b.scale).max(0.1);
-    let soft = pr.f("softness") / 100.0;
-    let disp = pr.e("displayOptions");
-    let base = Baseline::new(ctx, b);
-    let m = samples.len();
-    let mut pts = Vec::with_capacity(count);
-    let mut segs = Vec::new();
-    for i in 0..count {
-        let u = i as f64 / (count - 1) as f64;
-        let a = ((u * (m - 1) as f64) as usize).min(m - 1);
-        let bnd = (((i + 1) as f64 / count as f64 * (m - 1) as f64) as usize).clamp(a, m - 1);
-        // Peak with sign of the window for a stable digital display.
-        let (mut lo, mut hi) = (0.0f64, 0.0f64);
-        for s in &samples[a..=bnd] {
-            lo = lo.min(*s);
-            hi = hi.max(*s);
-        }
-        let (q, nrm) = base.at(u);
-        match disp {
-            0 => segs.push(Seg {
-                a: [q[0] + nrm[0] * lo * max_h, q[1] + nrm[1] * lo * max_h],
-                b: [q[0] + nrm[0] * hi * max_h, q[1] + nrm[1] * hi * max_h],
-                r: thick * 0.5,
-                v: 1.0,
-            }),
-            _ => {
-                let v = samples[a] * max_h;
-                pts.push([q[0] + nrm[0] * v, q[1] + nrm[1] * v]);
-            }
-        }
-    }
-    if disp == 1 {
-        poly_segs(&pts, false, thick * 0.5, 1.0, &mut segs);
-    } else if disp == 2 {
-        segs.extend(pts.iter().map(|&q| Seg { a: q, b: q, r: thick * 0.5, v: 1.0 }));
-    }
-    Some(marks(ctx, segs, thick, soft))
-}
-
-// ---------------------------------------------------------------- registry
-
-pub fn specs() -> Vec<EffectSpec> {
-    let ang = || ParamUi::Angle;
-    let check = |id: &'static str, name: &'static str, v: bool| p(id, name, Value::Bool(v), ParamUi::Checkbox);
-    let paint_style = || popup(&["On Original Image", "On Transparent", "Reveal Original Image"]);
-    let mask_idx = |id: &'static str, name: &'static str, d: f64| p(id, name, num(d), ParamUi::Mask);
-    let display = || popup(&["Digital", "Analog lines", "Analog dots"]);
-    vec![
-        spec(
-            "ec.generate.fractal",
-            "Fractal",
-            vec![
-                p("setChoice", "Set Choice", Value::Enum(0), popup(&FRACTAL_SETS)),
-                p("equation", "Equation", Value::Enum(0), popup(&["z = z^2 + c", "z = z^3 + c", "z = z^4 + c"])),
-                p("mandelbrot/mandelbrotX", "X (Real)", num(-0.74), slider(-2.0, 2.0, -2.0, 2.0, 4)),
-                p("mandelbrot/mandelbrotY", "Y (Imaginary)", num(0.15), slider(-2.0, 2.0, -2.0, 2.0, 4)),
-                p("mandelbrot/mandelbrotMagnification", "Magnification", num(0.0), slider(-5.0, 30.0, -5.0, 30.0, 2)),
-                p("mandelbrot/mandelbrotEscapeLimit", "Escape Limit", num(4.0), slider(1.0, 1000.0, 1.0, 100.0, 1)),
-                p("julia/juliaX", "X (Real)", num(0.0), slider(-2.0, 2.0, -2.0, 2.0, 4)),
-                p("julia/juliaY", "Y (Imaginary)", num(0.0), slider(-2.0, 2.0, -2.0, 2.0, 4)),
-                p("julia/juliaMagnification", "Magnification", num(0.0), slider(-5.0, 30.0, -5.0, 30.0, 2)),
-                p("julia/juliaEscapeLimit", "Escape Limit", num(4.0), slider(1.0, 1000.0, 1.0, 100.0, 1)),
-                p("postInversionOffset/postInversionX", "X Offset", num(0.0), slider(-2.0, 2.0, -2.0, 2.0, 4)),
-                p("postInversionOffset/postInversionY", "Y Offset", num(0.0), slider(-2.0, 2.0, -2.0, 2.0, 4)),
-                check("fractalColor/overlay", "Overlay", false),
-                check("fractalColor/transparency", "Transparency", false),
-                p("fractalColor/palette", "Palette", Value::Enum(0), popup(&FRACTAL_PALETTES)),
-                p("fractalColor/hue", "Hue", num(0.0), ang()),
-                p("fractalColor/cycleSteps", "Cycle Steps", num(32.0), slider(1.0, 1000.0, 1.0, 256.0, 0)),
-                p("fractalColor/cycleOffset", "Cycle Offset", num(0.0), ang()),
-                check("fractalColor/edgeHighlight", "Edge Highlight", false),
-                p("highQualitySettings/samplingMethod", "Oversample Method", Value::Enum(0), popup(&FRACTAL_OVERSAMPLE)),
-                p("highQualitySettings/samplingFactor", "Oversample Factor", num(2.0), slider(1.0, 9.0, 1.0, 9.0, 0)),
-            ],
-            fractal,
-        ),
-        spec(
-            "ec.generate.scribble",
-            "Scribble",
-            vec![
-                p("scribble", "Scribble", Value::Enum(0), popup(&["Single Mask", "All Masks", "All Masks Using Modes"])),
-                mask_idx("mask", "Mask", 1.0),
-                p("fillType", "Fill Type", Value::Enum(0), popup(&["Inside", "Centered Edge", "Inside Edge", "Outside Edge", "Left Edge", "Right Edge"])),
-                p("edgeOptions/edgeWidth", "Edge Width", num(10.0), slider(0.0, 1000.0, 0.0, 100.0, 1)),
-                p("edgeOptions/endCap", "End Cap", Value::Enum(0), popup(&END_CAPS)),
-                p("edgeOptions/join", "Join", Value::Enum(0), popup(&JOINS)),
-                p("edgeOptions/miterLimit", "Miter Limit", num(4.0), slider(1.0, 100.0, 1.0, 20.0, 1)),
-                p("color", "Color", col(1.0, 0.0, 0.0), ParamUi::Color),
-                p("opacity", "Opacity", num(100.0), pct()),
-                p("angle", "Angle", num(45.0), ang()),
-                p("strokeWidth", "Stroke Width", num(2.0), slider(0.1, 50.0, 0.1, 50.0, 1)),
-                p("strokeOptions/curviness", "Curviness", num(50.0), pct()),
-                p("strokeOptions/curvinessVariation", "Curviness Variation", num(50.0), pct()),
-                p("strokeOptions/spacing", "Spacing", num(5.0), slider(0.1, 100.0, 0.1, 50.0, 1)),
-                p("strokeOptions/spacingVariation", "Spacing Variation", num(50.0), pct()),
-                p("strokeOptions/pathOverlap", "Path Overlap", num(0.0), slider(-100.0, 100.0, -100.0, 100.0, 1)),
-                p("strokeOptions/pathOverlapVariation", "Path Overlap Variation", num(50.0), pct()),
-                p("start", "Start", num(0.0), pct()),
-                p("end", "End", num(100.0), pct()),
-                p("startEndApplyTo", "Start/End Apply To", Value::Enum(0), popup(&["All Strokes", "Each Stroke"])),
-                check("fillPathsSequentially", "Fill Paths Sequentially", true),
-                p("wiggleType", "Wiggle Type", Value::Enum(1), popup(&["Static", "Jumpy", "Smooth"])),
-                p("wigglesPerSecond", "Wiggles/Second", num(5.0), slider(0.0, 100.0, 0.0, 30.0, 2)),
-                p("randomSeed", "Random Seed", num(1.0), slider(0.0, 10000.0, 0.0, 100.0, 0)),
-                p("composite", "Composite", Value::Enum(1), popup(&["On Original Image", "On Transparent", "Reveal Original Image"])),
-            ],
-            scribble,
-        ),
-        spec(
-            "ec.generate.stroke",
-            "Stroke",
-            vec![
-                mask_idx("path", "Path", 1.0),
-                check("allMasks", "All Masks", false),
-                check("strokeSequentially", "Stroke Sequentially", true),
-                p("color", "Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("brushSize", "Brush Size", num(2.0), slider(0.0, 50.0, 0.0, 50.0, 1)),
-                p("brushHardness", "Brush Hardness", num(75.0), pct()),
-                p("opacity", "Opacity", num(100.0), pct()),
-                p("start", "Start", num(0.0), pct()),
-                p("end", "End", num(100.0), pct()),
-                p("spacing", "Spacing", num(15.0), slider(0.0, 100.0, 0.0, 100.0, 1)),
-                p("paintStyle", "Paint Style", Value::Enum(0), paint_style()),
-            ],
-            stroke,
-        ),
-        spec(
-            "ec.generate.vegas",
-            "Vegas",
-            vec![
-                p("stroke", "Stroke", Value::Enum(0), popup(&["Image Contours", "Mask/Path"])),
-                p("inputLayer", "Image Contours: Input Layer", Value::Layer(None), ParamUi::Layer),
-                check("invertInput", "Image Contours: Invert Input", false),
-                p("ifLayerSizesDiffer", "Image Contours: If Layer Sizes Differ", Value::Enum(0), popup(&["Center", "Stretch to Fit"])),
-                p("channel", "Image Contours: Channel", Value::Enum(0), popup(&["Intensity", "Red", "Green", "Blue", "Alpha"])),
-                p("threshold", "Image Contours: Threshold", num(50.0), pct()),
-                p("preBlur", "Image Contours: Pre-Blur", num(1.0), slider(0.0, 100.0, 0.0, 20.0, 1)),
-                p("tolerance", "Image Contours: Tolerance", num(0.01), slider(0.0, 1.0, 0.0, 0.1, 3)),
-                p("renderMode", "Image Contours: Render", Value::Enum(0), popup(&["All Contours", "Selected Contour"])),
-                p("selectedContour", "Image Contours: Selected Contour", num(1.0), slider(1.0, 1000.0, 1.0, 20.0, 0)),
-                p("shorterContoursHave", "Image Contours: Shorter Contours Have", Value::Enum(0), popup(&["Same Number of Segments", "Fewer Segments"])),
-                mask_idx("path", "Mask/Path: Path", 1.0),
-                p("segments", "Segments: Segments", num(32.0), slider(1.0, 1000.0, 1.0, 100.0, 0)),
-                p("length", "Segments: Length", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("segmentDistribution", "Segments: Segment Distribution", Value::Enum(0), popup(&["Bunched", "Even"])),
-                p("rotation", "Segments: Rotation", num(0.0), ang()),
-                check("randomPhase", "Segments: Random Phase", false),
-                p("randomSeed", "Segments: Random Seed", num(1.0), slider(1.0, 10000.0, 1.0, 100.0, 0)),
-                p("blendMode", "Rendering: Blend Mode", Value::Enum(1), popup(&["Transparent", "Over", "Under", "Stencil"])),
-                p("color", "Rendering: Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("width", "Rendering: Width", num(2.0), slider(0.0, 100.0, 0.0, 20.0, 2)),
-                p("hardness", "Rendering: Hardness", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("startOpacity", "Rendering: Start Opacity", num(1.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("midpointOpacity", "Rendering: Mid-point Opacity", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("midpointPosition", "Rendering: Mid-point Position", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("endOpacity", "Rendering: End Opacity", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
-            ],
-            vegas,
-        ),
-        spec(
-            "ec.generate.writeon",
-            "Write-on",
-            vec![
-                p("brushPosition", "Brush Position", pt(0.5, 0.5), ParamUi::Point),
-                p("color", "Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("brushSize", "Brush Size", num(6.0), slider(0.0, 50.0, 0.0, 50.0, 1)),
-                p("brushHardness", "Brush Hardness", num(75.0), pct()),
-                p("brushOpacity", "Brush Opacity", num(100.0), pct()),
-                p("strokeLength", "Stroke Length (secs)", num(0.0), slider(0.0, 30.0, 0.0, 30.0, 1)),
-                p("brushSpacing", "Brush Spacing (secs)", num(0.001), slider(0.001, 5.0, 0.001, 5.0, 3)),
-                p("paintTimeProperties", "Paint Time Properties", Value::Enum(0), popup(&["None", "Opacity", "Color"])),
-                p("brushTimeProperties", "Brush Time Properties", Value::Enum(0), popup(&["None", "Size", "Hardness", "Size & Hardness"])),
-                p("paintStyle", "Paint Style", Value::Enum(0), paint_style()),
-            ],
-            write_on,
-        ),
-        spec(
-            "ec.generate.paintbucket",
-            "Paint Bucket",
-            vec![
-                p("fillPoint", "Fill Point", pt(0.5, 0.5), ParamUi::Point),
-                p("fillSelector", "Fill Selector", Value::Enum(0), popup(&["Color & Alpha", "Straight Color", "Transparency", "Opacity", "Alpha Channel"])),
-                p("tolerance", "Tolerance", num(10.0), slider(0.0, 255.0, 0.0, 100.0, 1)),
-                check("viewThreshold", "View Threshold", false),
-                p("stroke", "Stroke", Value::Enum(0), popup(&["Antialias", "Feather", "Spread", "Choke", "Stroke"])),
-                p("featherSoftness", "Feather Softness", num(10.0), slider(0.0, 100.0, 0.0, 50.0, 1)),
-                p("spreadRadius", "Spread Radius", num(3.0), slider(0.0, 100.0, 0.0, 20.0, 1)),
-                p("strokeWidth", "Stroke Width", num(2.0), slider(0.0, 100.0, 0.0, 20.0, 1)),
-                p("color", "Color", col(1.0, 0.0, 0.0), ParamUi::Color),
-                p("opacity", "Opacity", num(100.0), pct()),
-                p(
-                    "blendingMode",
-                    "Blending Mode",
-                    Value::Enum(0),
-                    popup(&["Normal", "Add", "Multiply", "Screen", "Hue", "Saturation", "Color", "Luminosity", "Behind", "Fill Only"]),
-                ),
-            ],
-            paint_bucket,
-        ),
-        spec(
-            "ec.generate.eyedropperfill",
-            "Eyedropper Fill",
-            vec![
-                p("samplePoint", "Sample Point", pt(0.5, 0.5), ParamUi::Point),
-                p("sampleRadius", "Sample Radius", num(0.0), slider(0.0, 1000.0, 0.0, 100.0, 1)),
-                p("averagePixelColors", "Average Pixel Colors", Value::Enum(0), popup(&["Skip Empty", "All", "All Premultiplied", "Including Alpha"])),
-                check("maintainOriginalAlpha", "Maintain Original Alpha", false),
-                p("blendWithOriginal", "Blend With Original", num(0.0), pct()),
-            ],
-            eyedropper_fill,
-        ),
-        spec(
-            "ec.generate.ccgluegun",
-            "CC Glue Gun",
-            vec![
-                p("brushPosition", "Brush Position", pt(0.5, 0.5), ParamUi::Point),
-                p("strokeWidth", "Stroke Width", num(25.0), slider(0.0, 500.0, 0.0, 100.0, 1)),
-                p("density", "Density", num(5.0), slider(0.0, 32.0, 0.0, 32.0, 1)),
-                p("timeSpan", "Time Span (sec)", num(1.0), slider(0.0, 60.0, 0.0, 10.0, 2)),
-                p("reflection", "Reflection", num(45.0), ang()),
-                p("strength", "Strength", num(100.0), pct()),
-                p("style", "Style", Value::Enum(0), popup(&["Over Layer", "Glue Only"])),
-            ],
-            glue_gun,
-        ),
-        spec(
-            "ec.generate.ccthreads",
-            "CC Threads",
-            vec![
-                p("width", "Width", num(50.0), slider(1.0, 1000.0, 1.0, 200.0, 1)),
-                p("height", "Height", num(50.0), slider(1.0, 1000.0, 1.0, 200.0, 1)),
-                p("overlaps", "Overlaps", num(1.0), slider(1.0, 20.0, 1.0, 10.0, 0)),
-                p("direction", "Direction", num(0.0), ang()),
-                p("center", "Center", pt(0.5, 0.5), ParamUi::Point),
-                p("coverage", "Coverage", num(80.0), pct()),
-                p("shadowing", "Shadowing", num(50.0), pct()),
-                p("texture", "Texture", num(10.0), pct()),
-            ],
-            threads,
-        ),
-        spec(
-            "ec.generate.audiospectrum",
-            "Audio Spectrum",
-            vec![
-                p("audioLayer", "Audio Layer", Value::Layer(None), ParamUi::Layer),
-                p("startPoint", "Start Point", pt(0.1, 0.5), ParamUi::Point),
-                p("endPoint", "End Point", pt(0.9, 0.5), ParamUi::Point),
-                mask_idx("path", "Path", 0.0),
-                check("usePolarPath", "Use Polar Path", false),
-                p("startFrequency", "Start Frequency", num(20.0), slider(1.0, 20000.0, 1.0, 2000.0, 0)),
-                p("endFrequency", "End Frequency", num(2000.0), slider(1.0, 20000.0, 1.0, 10000.0, 0)),
-                p("frequencyBands", "Frequency bands", num(64.0), slider(1.0, 4096.0, 1.0, 256.0, 0)),
-                p("maximumHeight", "Maximum Height", num(50.0), slider(0.0, 10000.0, 0.0, 500.0, 1)),
-                p("audioDuration", "Audio Duration (milliseconds)", num(90.0), slider(1.0, 30000.0, 1.0, 1000.0, 1)),
-                p("audioOffset", "Audio Offset (milliseconds)", num(0.0), slider(-30000.0, 30000.0, -1000.0, 1000.0, 1)),
-                p("thickness", "Thickness", num(3.0), slider(0.0, 1000.0, 0.0, 50.0, 2)),
-                p("softness", "Softness", num(50.0), pct()),
-                p("insideColor", "Inside Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("outsideColor", "Outside Color", col(0.2, 0.4, 1.0), ParamUi::Color),
-                check("blendOverlappingColors", "Blend Overlapping Colors", true),
-                p("hueInterpolation", "Hue Interpolation", num(0.0), ang()),
-                check("dynamicHuePhase", "Dynamic Hue Phase", false),
-                check("colorSymmetry", "Color Symmetry", false),
-                p("displayOptions", "Display Options", Value::Enum(0), display()),
-                p("sideOptions", "Side Options", Value::Enum(0), popup(&["Side A", "Side B", "Side A & B"])),
-                check("durationAveraging", "Duration Averaging", false),
-                check("compositeOnOriginal", "Composite On Original", false),
-            ],
-            audio_spectrum,
-        ),
-        spec(
-            "ec.generate.audiowaveform",
-            "Audio Waveform",
-            vec![
-                p("audioLayer", "Audio Layer", Value::Layer(None), ParamUi::Layer),
-                p("startPoint", "Start Point", pt(0.1, 0.5), ParamUi::Point),
-                p("endPoint", "End Point", pt(0.9, 0.5), ParamUi::Point),
-                mask_idx("path", "Path", 0.0),
-                check("usePolarPath", "Use Polar Path", false),
-                p("displayedSamples", "Displayed Samples", num(200.0), slider(2.0, 4096.0, 2.0, 1000.0, 0)),
-                p("maximumHeight", "Maximum Height", num(100.0), slider(0.0, 10000.0, 0.0, 500.0, 1)),
-                p("audioDuration", "Audio Duration (milliseconds)", num(200.0), slider(1.0, 30000.0, 1.0, 1000.0, 1)),
-                p("audioOffset", "Audio Offset (milliseconds)", num(0.0), slider(-30000.0, 30000.0, -1000.0, 1000.0, 1)),
-                p("thickness", "Thickness", num(2.0), slider(0.0, 1000.0, 0.0, 50.0, 2)),
-                p("softness", "Softness", num(10.0), pct()),
-                p("randomSeed", "Random Seed (Analog)", num(1.0), slider(1.0, 10000.0, 1.0, 100.0, 0)),
-                p("insideColor", "Inside Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("outsideColor", "Outside Color", col(0.2, 0.4, 1.0), ParamUi::Color),
-                p("waveformOptions", "Waveform Options", Value::Enum(0), popup(&["Mono", "Left", "Right"])),
-                p("displayOptions", "Display Options", Value::Enum(1), display()),
-                check("compositeOnOriginal", "Composite On Original", false),
-            ],
-            audio_waveform,
-        ),
-    ]
-}
+mod audio;
+mod common;
+mod fill;
+mod fractal;
+mod paths;
+mod raster;
+mod registry;
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::{EffectEnv, EffectHost, LayerPixels, MaskShape, Params};
+pub(crate) use audio::fft;
+pub use audio::{MarksPlan, marks_plan};
+pub use fill::{eyedropper_color, paint_bucket_region};
+#[cfg(test)]
+use paths::contours;
+pub use paths::{Coverage, PaintPlan, paint_plan, plan_reads_pixels, scribble_style};
+pub use raster::{Seg, poly_segs};
+pub(crate) use raster::{mask_px, raster_segs};
+#[cfg(test)]
+pub(crate) use raster::{raster_convex, stroke_outline};
+pub use registry::specs;
 
-    /// Run with point defaults scaled to the layer size.
-    pub(crate) fn run_env(id: &str, set: &[(&str, Value)], img: Image, time: f64, env: EffectEnv) -> Buf {
-        let s = crate::find(id).unwrap();
-        let ls = [img.width as f64, img.height as f64];
-        let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-        for p in &s.params {
-            if let (ParamUi::Point, Value::Vec2(v)) = (&p.ui, &p.default) {
-                params.values.insert(p.id.to_string(), Value::Vec2([v[0] * ls[0], v[1] * ls[1]]));
-            }
-        }
-        for (k, v) in set {
-            assert!(params.values.contains_key(*k), "{id}: unknown {k}");
-            params.values.insert(k.to_string(), v.clone());
-        }
-        let ctx = EffectCtx { params: &params, time, layer_size: ls, seed: 3, adjustment: false, env };
-        crate::apply(s, &ctx, Buf { img, offset: [0.0, 0.0], scale: 1.0 })
-    }
-
-    fn run(id: &str, set: &[(&str, Value)], img: Image) -> Buf {
-        run_env(id, set, img, 0.5, EffectEnv::default())
-    }
-
-    fn square_mask() -> Vec<MaskShape> {
-        vec![MaskShape { name: "Mask 1".into(), points: vec![[16.0, 16.0], [48.0, 16.0], [48.0, 48.0], [16.0, 48.0]], closed: true, inverted: false }]
-    }
-
-    fn alpha_sum(img: &Image, x0: usize, y0: usize, x1: usize, y1: usize) -> f32 {
-        let mut s = 0.0;
-        for y in y0..y1 {
-            for x in x0..x1 {
-                s += img.data[y * img.width as usize + x][3];
-            }
-        }
-        s
-    }
-
-    #[test]
-    fn audio_spectrum_linear_frequency_and_linear_amplitude() {
-        let host = Tone; // Tone produces 440 Hz
-        let env = EffectEnv { host: Some(&host), comp_time: 1.0, ..Default::default() };
-        let img = Image::new(200, 100);
-        let out = run_env(
-            "ec.generate.audiospectrum",
-            &[
-                ("audioLayer", Value::Layer(Some(1))),
-                ("startPoint", Value::Vec2([0.0, 50.0])),
-                ("endPoint", Value::Vec2([200.0, 50.0])),
-                ("startFrequency", num(20.0)),
-                ("endFrequency", num(2000.0)),
-                ("frequencyBands", num(100.0)),
-                ("maximumHeight", num(40.0)),
-                ("thickness", num(2.0)),
-                ("softness", num(0.0)),
-            ],
-            img,
-            1.0,
-            env,
-        );
-        // Verify 440 Hz tone produces a peak above baseline, while high frequencies have zero bar height
-        let peak_zone = alpha_sum(&out.img, 36, 10, 48, 48);
-        let high_zone = alpha_sum(&out.img, 120, 10, 150, 48);
-        let silent_zone = alpha_sum(&out.img, 170, 10, 195, 48);
-        assert!(peak_zone > 5.0, "peak zone has energy: {peak_zone}");
-        assert!(peak_zone > high_zone * 2.0, "linear peak is distinctly taller than far frequencies: {peak_zone} vs {high_zone}");
-        assert_eq!(silent_zone, 0.0, "silent end has zero height, not boosted by dB scale");
-    }
-
-    #[test]
-    fn fractal_deterministic_and_has_inside_set() {
-        let img = Image::new(64, 48);
-        let a = run("ec.generate.fractal", &[], img.clone());
-        let b = run("ec.generate.fractal", &[], img.clone());
-        assert_eq!(a.img.data, b.img.data);
-        // The default view contains the main cardioid (black, opaque) and escaped (coloured) points.
-        assert!(a.img.data.iter().any(|p| p[3] > 0.99 && p[0] + p[1] + p[2] < 0.01));
-        assert!(a.img.data.iter().any(|p| p[0] + p[1] + p[2] > 0.3));
-        let t = run("ec.generate.fractal", &[("fractalColor/transparency", Value::Bool(true))], img);
-        assert!(t.img.data.iter().any(|p| p[3] == 0.0));
-    }
-
-    #[test]
-    fn fractal_palettes_and_set_choices() {
-        let img = Image::new(64, 48);
-        // Solid Color: only the inside of the set is drawn; Transparency flips it.
-        let solid = run("ec.generate.fractal", &[("fractalColor/palette", Value::Enum(3))], img.clone());
-        assert!(solid.img.data.iter().any(|p| p[3] == 0.0) && solid.img.data.iter().any(|p| p[3] > 0.99 && p[0] > 0.9));
-        let flipped = run("ec.generate.fractal", &[("fractalColor/palette", Value::Enum(3)), ("fractalColor/transparency", Value::Bool(true))], img.clone());
-        for (a, b) in solid.img.data.iter().zip(&flipped.img.data) {
-            assert!((a[3] > 0.5) != (b[3] > 0.5) || (a[3] - 0.5).abs() < 0.49);
-        }
-        // Black And White: escaped pixels are pure black or white (away from supersampled edges).
-        let bw = run("ec.generate.fractal", &[("fractalColor/palette", Value::Enum(2)), ("highQualitySettings/samplingFactor", num(1.0))], img.clone());
-        assert!(bw.img.data.iter().all(|p| p[0] == p[1] && p[1] == p[2] && (p[0] == 0.0 || p[0] == 1.0)));
-        // Mandelbrot Over Julia depends on the Julia centre.
-        let o1 = run("ec.generate.fractal", &[("setChoice", Value::Enum(2)), ("julia/juliaX", num(0.3))], img.clone());
-        let o2 = run("ec.generate.fractal", &[("setChoice", Value::Enum(2)), ("julia/juliaX", num(-0.2))], img.clone());
-        assert_ne!(o1.img.data, o2.img.data);
-        let plain = run("ec.generate.fractal", &[("julia/juliaX", num(0.3))], img);
-        assert_ne!(o1.img.data, plain.img.data);
-    }
-
-    #[test]
-    fn scribble_fills_mask_and_animates() {
-        let masks = square_mask();
-        let env = EffectEnv { masks: &masks, ..Default::default() };
-        let img = Image::filled(64, 64, [0.0, 0.0, 1.0, 1.0]);
-        let a = run_env("ec.generate.scribble", &[], img.clone(), 0.5, env);
-        let b = run_env("ec.generate.scribble", &[], img.clone(), 0.5, env);
-        assert_eq!(a.img.data, b.img.data);
-        let inside = alpha_sum(&a.img, 18, 18, 46, 46);
-        let outside = alpha_sum(&a.img, 0, 0, 10, 64);
-        assert!(inside > 100.0 && outside < 1.0, "{inside} {outside}");
-        let c = run_env("ec.generate.scribble", &[], img.clone(), 1.5, env);
-        assert_ne!(a.img.data, c.img.data, "jumpy wiggle changes over time");
-        let s = run_env("ec.generate.scribble", &[("wiggleType", Value::Enum(0))], img.clone(), 0.5, env);
-        let s2 = run_env("ec.generate.scribble", &[("wiggleType", Value::Enum(0))], img.clone(), 3.5, env);
-        assert_eq!(s.img.data, s2.img.data, "static wiggle is constant");
-        let half = run_env("ec.generate.scribble", &[("end", num(50.0))], img, 0.5, env);
-        assert!(alpha_sum(&half.img, 0, 0, 64, 64) < alpha_sum(&a.img, 0, 0, 64, 64));
-    }
-
-    #[test]
-    fn scribble_edge_types() {
-        let masks = square_mask();
-        let env = EffectEnv { masks: &masks, ..Default::default() };
-        let img = Image::new(64, 64);
-        let o = run_env("ec.generate.scribble", &[("fillType", Value::Enum(3)), ("edgeOptions/edgeWidth", num(6.0))], img, 0.5, env);
-        // Outside edge: paint near the border outside, nothing in the centre.
-        assert!(alpha_sum(&o.img, 26, 26, 38, 38) < 0.5);
-        assert!(alpha_sum(&o.img, 8, 8, 16, 56) > 5.0);
-    }
-
-    #[test]
-    fn stroke_draws_along_mask() {
-        let masks = square_mask();
-        let env = EffectEnv { masks: &masks, ..Default::default() };
-        let img = Image::new(64, 64);
-        let a = run_env("ec.generate.stroke", &[("brushSize", num(4.0)), ("paintStyle", Value::Enum(1))], img.clone(), 0.0, env);
-        assert!(a.img.get(32, 16)[3] > 0.9, "on the top edge");
-        assert!(a.img.get(32, 32)[3] < 0.01, "centre empty");
-        let b = run_env("ec.generate.stroke", &[("brushSize", num(4.0)), ("end", num(25.0))], img.clone(), 0.0, env);
-        assert!(b.img.get(32, 16)[3] > 0.9 && b.img.get(48, 32)[3] < 0.01, "first quarter only");
-        let d = run_env("ec.generate.stroke", &[("brushSize", num(4.0)), ("spacing", num(300.0))], img, 0.0, env);
-        assert!(alpha_sum(&d.img, 0, 0, 64, 64) < alpha_sum(&a.img, 0, 0, 64, 64), "spaced dabs");
-        // No masks: unchanged.
-        let src = Image::filled(8, 8, [0.2, 0.3, 0.4, 1.0]);
-        assert_eq!(run("ec.generate.stroke", &[], src.clone()).img.data, src.data);
-    }
-
-    #[test]
-    fn vegas_traces_contours() {
-        let mut img = Image::new(64, 64);
-        for y in 16..48 {
-            for x in 16..48 {
-                img.set(x, y, [1.0, 1.0, 1.0, 1.0]);
-            }
-        }
-        let a = run(
-            "ec.generate.vegas",
-            &[("blendMode", Value::Enum(0)), ("length", num(1.0)), ("midpointOpacity", num(1.0)), ("endOpacity", num(1.0))],
-            img.clone(),
-        );
-        let b = run(
-            "ec.generate.vegas",
-            &[("blendMode", Value::Enum(0)), ("length", num(1.0)), ("midpointOpacity", num(1.0)), ("endOpacity", num(1.0))],
-            img.clone(),
-        );
-        assert_eq!(a.img.data, b.img.data);
-        assert!(alpha_sum(&a.img, 14, 14, 50, 50) > 50.0, "edges drawn");
-        assert!(alpha_sum(&a.img, 26, 26, 38, 38) < 0.5, "interior untouched");
-        let r = run("ec.generate.vegas", &[("blendMode", Value::Enum(0)), ("rotation", num(90.0))], img);
-        assert_ne!(r.img.data, a.img.data);
-    }
-
-    #[test]
-    fn contours_of_square_are_closed() {
-        let mut pl = Plane::new(20, 20);
-        for y in 5..15 {
-            for x in 5..15 {
-                pl.data[y * 20 + x] = 1.0;
-            }
-        }
-        let c = contours(&pl, 0.5);
-        assert_eq!(c.len(), 1);
-        assert!(c[0].1);
-        let l = poly_length(&c[0].0, true);
-        assert!((l - 40.0).abs() < 4.0, "{l}");
-    }
-
-    #[test]
-    fn write_on_and_glue_gun_draw_at_brush() {
-        let img = Image::new(32, 32);
-        let a = run("ec.generate.writeon", &[], img.clone());
-        assert!(a.img.get(16, 16)[3] > 0.9 && a.img.get(2, 2)[3] == 0.0);
-        assert_eq!(a.img.data, run("ec.generate.writeon", &[], img.clone()).img.data);
-        let src = Image::filled(32, 32, [0.5, 0.2, 0.1, 1.0]);
-        let g = run("ec.generate.ccgluegun", &[], src.clone());
-        assert_eq!(g.img.data, run("ec.generate.ccgluegun", &[], src.clone()).img.data);
-        assert_ne!(g.img.get(16, 16), src.get(16, 16));
-        assert_eq!(g.img.get(0, 0), src.get(0, 0));
-    }
-
-    /// #536: an animated Brush Position draws a stroke that stays (Stroke Length 0), expires
-    /// after Stroke Length, and lays its dabs Brush Spacing seconds apart.
-    #[test]
-    fn write_on_accumulates_a_stroke_along_the_animated_brush() {
-        // Brush Position from [8, 16] at 0 s to [56, 16] at 1 s; red, hard, 6 px.
-        struct Brush(Vec<(&'static str, Value)>);
-        impl Brush {
-            fn at(&self, t: f64) -> Vec<(&'static str, Value)> {
-                let mut v = self.0.clone();
-                v.push(("brushPosition", Value::Vec2([8.0 + 48.0 * t.clamp(0.0, 1.0), 16.0])));
-                v
-            }
-        }
-        impl EffectHost for Brush {
-            fn layer(&self, _: u64, _: bool) -> Option<LayerPixels> {
-                None
-            }
-            fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
-                None
-            }
-            fn params_at(&self, t: f64) -> Option<Params> {
-                let s = crate::find("ec.generate.writeon").unwrap();
-                let mut p = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-                for (k, v) in self.at(t) {
-                    p.values.insert(k.to_string(), v);
-                }
-                Some(p)
-            }
-        }
-        let render = |extra: &[(&'static str, Value)], t: f64| {
-            let mut set = vec![("color", col(1.0, 0.0, 0.0)), ("brushSize", num(6.0)), ("brushHardness", num(100.0)), ("brushSpacing", num(0.05))];
-            set.extend(extra.iter().cloned());
-            let host = Brush(set);
-            let env = EffectEnv { host: Some(&host), ..Default::default() };
-            let at = host.at(t);
-            run_env("ec.generate.writeon", &at, Image::new(64, 32), t, env).img
-        };
-        let on = |img: &Image, x: i64| img.get(x, 16)[3] > 0.9;
-        let half = render(&[], 0.5);
-        assert!(on(&half, 8) && on(&half, 20) && on(&half, 32) && !on(&half, 44) && !on(&half, 56));
-        let end = render(&[], 1.0);
-        assert!([8, 20, 32, 44, 56].iter().all(|x| on(&end, *x)));
-        // Stroke Length 0.25 s: only the last quarter second's trail.
-        let trail = render(&[("strokeLength", num(0.25))], 1.0);
-        assert!(!on(&trail, 8) && !on(&trail, 32) && on(&trail, 48) && on(&trail, 56));
-        // Brush Spacing 0.5 s: three separate marks.
-        let spaced = render(&[("brushSpacing", num(0.5))], 1.0);
-        assert!(on(&spaced, 8) && on(&spaced, 32) && on(&spaced, 56) && !on(&spaced, 20) && !on(&spaced, 44));
-        // Paint Time Properties ▸ Opacity: each dab keeps the opacity it was laid with.
-        struct Fade;
-        impl EffectHost for Fade {
-            fn layer(&self, _: u64, _: bool) -> Option<LayerPixels> {
-                None
-            }
-            fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
-                None
-            }
-            fn params_at(&self, t: f64) -> Option<Params> {
-                let mut p = Brush(vec![("brushHardness", num(100.0)), ("brushSpacing", num(0.05)), ("paintTimeProperties", Value::Enum(1))]).params_at(t)?;
-                p.values.insert("brushOpacity".into(), num(if t < 0.5 { 100.0 } else { 20.0 }));
-                Some(p)
-            }
-        }
-        let p1 = Fade.params_at(1.0).unwrap();
-        let set: Vec<(&str, Value)> = p1.values.iter().map(|(k, v)| (k.as_str(), v.clone())).collect();
-        let faded = run_env("ec.generate.writeon", &set, Image::new(64, 32), 1.0, EffectEnv { host: Some(&Fade), ..Default::default() }).img;
-        assert!(faded.get(8, 16)[3] > 0.9 && (faded.get(56, 16)[3] - 0.2).abs() < 0.05, "{:?} {:?}", faded.get(8, 16), faded.get(56, 16));
-    }
-
-    #[test]
-    fn paint_bucket_fills_enclosed_region_only() {
-        let mut img = Image::filled(32, 32, [1.0, 1.0, 1.0, 1.0]);
-        for i in 8..24 {
-            for &(x, y) in &[(i, 8), (i, 23), (8, i), (23, i)] {
-                img.set(x, y, [0.0, 0.0, 0.0, 1.0]);
-            }
-        }
-        let out = run("ec.generate.paintbucket", &[], img.clone());
-        let inside = out.img.get(16, 16);
-        assert!(inside[0] > 0.99 && inside[1] < 0.01, "{inside:?}");
-        assert_eq!(out.img.get(2, 2), [1.0, 1.0, 1.0, 1.0], "outside untouched");
-        assert_eq!(out.img.get(8, 16), [0.0, 0.0, 0.0, 1.0], "border untouched");
-        assert_eq!(out.img.data, run("ec.generate.paintbucket", &[], img).img.data);
-    }
-
-    #[test]
-    fn eyedropper_fill_uses_sample() {
-        let mut img = Image::filled(16, 16, [0.0, 0.0, 1.0, 1.0]);
-        img.set(8, 8, [1.0, 0.0, 0.0, 1.0]);
-        let out = run("ec.generate.eyedropperfill", &[], img.clone());
-        assert!(out.img.data.iter().all(|p| *p == [1.0, 0.0, 0.0, 1.0]));
-        let blended = run("ec.generate.eyedropperfill", &[("blendWithOriginal", num(100.0))], img.clone());
-        assert_eq!(blended.img.data, img.data);
-    }
-
-    #[test]
-    fn threads_weave_is_deterministic_and_gappy() {
-        let src = Image::filled(64, 64, [0.4, 0.6, 0.2, 1.0]);
-        let a = run("ec.generate.ccthreads", &[("width", num(16.0)), ("height", num(16.0)), ("coverage", num(50.0))], src.clone());
-        assert_eq!(a.img.data, run("ec.generate.ccthreads", &[("width", num(16.0)), ("height", num(16.0)), ("coverage", num(50.0))], src).img.data);
-        assert!(a.img.data.iter().any(|p| p[3] == 0.0), "gaps between threads");
-        assert!(a.img.data.iter().any(|p| p[3] > 0.99), "threads");
-    }
-
-    struct Tone;
-    impl EffectHost for Tone {
-        fn layer(&self, _: u64, _: bool) -> Option<LayerPixels> {
-            None
-        }
-        fn audio(&self, _: u64, start: f64, frames: usize, rate: u32) -> Option<Vec<f32>> {
-            Some(
-                (0..frames)
-                    .flat_map(|i| {
-                        let t = start + i as f64 / rate as f64;
-                        let v = (2.0 * PI * 440.0 * t).sin() as f32 * 0.8;
-                        [v, v]
-                    })
-                    .collect(),
-            )
-        }
-    }
-
-    #[test]
-    fn audio_effects_without_audio_pass_through() {
-        let src = Image::filled(16, 16, [0.3, 0.3, 0.3, 1.0]);
-        for id in ["ec.generate.audiospectrum", "ec.generate.audiowaveform"] {
-            assert_eq!(run(id, &[], src.clone()).img.data, src.data, "{id}");
-        }
-    }
-
-    #[test]
-    fn audio_effects_draw_with_host() {
-        let host = Tone;
-        let env = EffectEnv { host: Some(&host), comp_time: 1.0, ..Default::default() };
-        let img = Image::new(96, 64);
-        for id in ["ec.generate.audiospectrum", "ec.generate.audiowaveform"] {
-            let a = run_env(id, &[("audioLayer", Value::Layer(Some(1)))], img.clone(), 1.0, env);
-            let b = run_env(id, &[("audioLayer", Value::Layer(Some(1)))], img.clone(), 1.0, env);
-            assert_eq!(a.img.data, b.img.data, "{id}");
-            assert!(alpha_sum(&a.img, 0, 0, 96, 64) > 10.0, "{id} drew nothing");
-        }
-    }
-
-    #[test]
-    fn fft_finds_tone() {
-        let n = 256;
-        let mut re: Vec<f64> = (0..n).map(|i| (2.0 * PI * 8.0 * i as f64 / n as f64).cos()).collect();
-        let mut im = vec![0.0; n];
-        fft(&mut re, &mut im);
-        let mags: Vec<f64> = (0..n / 2).map(|k| (re[k] * re[k] + im[k] * im[k]).sqrt()).collect();
-        let peak = mags.iter().enumerate().max_by(|a, b| a.1.total_cmp(b.1)).unwrap().0;
-        assert_eq!(peak, 8);
-    }
-
-    #[test]
-    fn stroke_outline_caps_and_joins() {
-        let line = vec![vec![[10.0, 10.0], [30.0, 10.0]]];
-        let cov = |cap: u32| raster_convex(40, 20, &stroke_outline(&line, 3.0, cap, 0, 4.0));
-        // Round caps reach 3 px past the ends (on the axis), Butt stops there, Projecting is square.
-        let (round, butt, proj) = (cov(0), cov(1), cov(2));
-        assert!(round.get(8, 10) > 0.9 && butt.get(8, 10) < 0.1 && proj.get(8, 10) > 0.9);
-        assert!(proj.get(7, 7) > 0.9 && round.get(7, 7) < 0.5, "square corner");
-        // A right-angle turn: Miter fills the outer corner, Bevel cuts it.
-        let corner = vec![vec![[5.0, 30.0], [30.0, 30.0], [30.0, 5.0]]];
-        let j = |join: u32| raster_convex(40, 40, &stroke_outline(&corner, 3.0, 1, join, 4.0));
-        let (miter, bevel) = (j(1), j(2));
-        assert!(miter.get(32, 32) > 0.9 && bevel.get(32, 32) < 0.1, "{} {}", miter.get(32, 32), bevel.get(32, 32));
-        // A tight miter limit falls back to a bevel.
-        let limited = raster_convex(40, 40, &stroke_outline(&corner, 3.0, 1, 1, 1.0));
-        assert!(limited.get(32, 32) < 0.1);
-    }
-
-    #[test]
-    fn scribble_caps_and_start_end_apply_to() {
-        let masks = square_mask();
-        let env = EffectEnv { masks: &masks, ..Default::default() };
-        let img = Image::new(64, 64);
-        let base = [("wiggleType", Value::Enum(0)), ("strokeWidth", num(3.0))];
-        let round = run_env("ec.generate.scribble", &base, img.clone(), 0.0, env);
-        let butt = run_env(
-            "ec.generate.scribble",
-            &[base.as_slice(), &[("edgeOptions/endCap", Value::Enum(1)), ("edgeOptions/join", Value::Enum(2))]].concat(),
-            img.clone(),
-            0.0,
-            env,
-        );
-        assert_ne!(round.img.data, butt.img.data);
-        // Each Stroke: every stroke is trimmed on its own, so the half-way image has ink all over.
-        let two = vec![
-            crate::MaskShape { name: String::new(), points: vec![[4.0, 4.0], [28.0, 4.0], [28.0, 60.0], [4.0, 60.0]], closed: true, inverted: false },
-            crate::MaskShape { name: String::new(), points: vec![[36.0, 4.0], [60.0, 4.0], [60.0, 60.0], [36.0, 60.0]], closed: true, inverted: false },
-        ];
-        let env2 = EffectEnv { masks: &two, ..Default::default() };
-        let seq = [("scribble", Value::Enum(1)), ("end", num(50.0))];
-        let all = run_env("ec.generate.scribble", &[base.as_slice(), &seq].concat(), img.clone(), 0.0, env2);
-        let each = run_env("ec.generate.scribble", &[base.as_slice(), &seq, &[("startEndApplyTo", Value::Enum(1))]].concat(), img, 0.0, env2);
-        assert_ne!(all.img.data, each.img.data);
-    }
-}
+#[cfg(test)]
+mod tests;
diff --git a/crates/effects/src/generate3/audio.rs b/crates/effects/src/generate3/audio.rs
new file mode 100644
index 000000000..6c8d66e4a
--- /dev/null
+++ b/crates/effects/src/generate3/audio.rs
@@ -0,0 +1,314 @@
+use super::raster::{Seg, mask_px, over, poly_segs, raster_segs};
+use super::{Buf, EffectCtx, IndexedParallelIterator, IntoParallelRefMutIterator, PI, ParallelIterator, poly_length, premul};
+
+// ---------------------------------------------------------------- Audio Spectrum / Waveform
+
+/// In-place iterative radix-2 FFT (`re`, `im` lengths a power of two).
+pub(crate) fn fft(re: &mut [f64], im: &mut [f64]) {
+    let n = re.len();
+    if n < 2 {
+        return;
+    }
+    let mut j = 0;
+    for i in 1..n {
+        let mut bit = n >> 1;
+        while j & bit != 0 {
+            j ^= bit;
+            bit >>= 1;
+        }
+        j |= bit;
+        if i < j {
+            re.swap(i, j);
+            im.swap(i, j);
+        }
+    }
+    let mut len = 2;
+    while len <= n {
+        let ang = -2.0 * PI / len as f64;
+        let (ws, wc) = ang.sin_cos();
+        for start in (0..n).step_by(len) {
+            let (mut cr, mut ci) = (1.0, 0.0);
+            for k in 0..len / 2 {
+                let (a, bb) = (start + k, start + k + len / 2);
+                let tr = re[bb] * cr - im[bb] * ci;
+                let ti = re[bb] * ci + im[bb] * cr;
+                re[bb] = re[a] - tr;
+                im[bb] = im[a] - ti;
+                re[a] += tr;
+                im[a] += ti;
+                let ncr = cr * wc - ci * ws;
+                ci = cr * ws + ci * wc;
+                cr = ncr;
+            }
+        }
+        len <<= 1;
+    }
+}
+
+const AUDIO_RATE: u32 = 48_000;
+
+/// Fetch mono (or one channel) samples of the audio layer around the current time.
+fn audio_window(ctx: &EffectCtx, dur_ms: f64, offset_ms: f64, channel: u32) -> Option<Vec<f64>> {
+    let id = ctx.params.get("audioLayer")?.as_layer()?;
+    let host = ctx.env.host?;
+    let dur = (dur_ms / 1000.0).max(0.001);
+    let frames = ((dur * AUDIO_RATE as f64) as usize).clamp(16, 1 << 16);
+    let start = ctx.env.comp_time + offset_ms / 1000.0 - dur * 0.5;
+    let s = host.audio(id, start, frames, AUDIO_RATE)?;
+    Some(
+        (0..frames)
+            .map(|i| {
+                let (l, r) = (*s.get(2 * i).unwrap_or(&0.0) as f64, *s.get(2 * i + 1).unwrap_or(&0.0) as f64);
+                match channel {
+                    1 => l,
+                    2 => r,
+                    _ => (l + r) * 0.5,
+                }
+            })
+            .collect(),
+    )
+}
+
+/// The drawing baseline: a polyline in buffer px (mask path or start→end line), sampled at
+/// parameter u∈[0,1] → (point, unit normal).
+struct Baseline {
+    pts: Vec<[f64; 2]>,
+    closed: bool,
+    len: f64,
+    polar: bool,
+    center: [f64; 2],
+    radius: f64,
+}
+
+impl Baseline {
+    fn new(ctx: &EffectCtx, b: &Buf) -> Baseline {
+        let pr = ctx.params;
+        let polar = pr.b("usePolarPath");
+        let (pts, closed) = match mask_px(ctx, b, pr.f("path").round() as usize) {
+            Some((p, c, _)) if !polar => (p, c),
+            _ => {
+                let s = b.to_px(pr.v2("startPoint"));
+                let e = b.to_px(pr.v2("endPoint"));
+                (vec![[s.0, s.1], [e.0, e.1]], false)
+            }
+        };
+        let len = poly_length(&pts, closed);
+        let center = pts[0];
+        let radius = if pts.len() > 1 { ((pts[1][0] - pts[0][0]).powi(2) + (pts[1][1] - pts[0][1]).powi(2)).sqrt() } else { 1.0 };
+        Baseline { pts, closed, len, polar, center, radius }
+    }
+    fn at(&self, u: f64) -> ([f64; 2], [f64; 2]) {
+        if self.polar {
+            let a = u * 2.0 * PI - PI * 0.5;
+            let (s, c) = a.sin_cos();
+            return ([self.center[0] + c * self.radius * 0.5, self.center[1] + s * self.radius * 0.5], [c, s]);
+        }
+        let (q, d) = crate::util::poly_point_at(&self.pts, self.closed, u * self.len);
+        (q, [d[1], -d[0]])
+    }
+}
+
+/// Draw line/dot marks with core (inside colour) and soft halo (outside colour).
+fn draw_marks(b: &mut Buf, segs_core: &[Seg], thickness: f64, softness: f64, inside: [f32; 4], outside: [f32; 4], composite: bool) {
+    let (w, h) = (b.img.width as usize, b.img.height as usize);
+    let core = raster_segs(w, h, segs_core, 1.0);
+    let halo_segs: Vec<Seg> = segs_core.iter().map(|s| Seg { r: s.r + thickness * softness.max(0.0) + 0.5, ..*s }).collect();
+    let halo = if softness > 0.0 { raster_segs(w, h, &halo_segs, 0.0) } else { core.clone() };
+    b.img.data.par_iter_mut().enumerate().for_each(|(i, px)| {
+        let (c, hl) = (core.data[i], halo.data[i]);
+        let a = c.max(hl);
+        let base = if composite { *px } else { [0.0; 4] };
+        if a <= 0.0 {
+            *px = base;
+            return;
+        }
+        let t = if a > 0.0 { c / a } else { 0.0 };
+        let col = crate::util::lerp3([outside[0], outside[1], outside[2]], [inside[0], inside[1], inside[2]], t);
+        *px = over(base, premul(col, a));
+    });
+}
+
+/// Audio Spectrum / Audio Waveform, shared with the GPU compositor (effectcraft-gpu `fx_gen2`):
+/// the marks (the audio analysis runs on the CPU) and how `draw_marks` colours them.
+#[derive(Clone, Debug)]
+pub struct MarksPlan {
+    pub segs: Vec<Seg>,
+    pub thickness: f64,
+    pub softness: f64,
+    pub inside: [f32; 4],
+    pub outside: [f32; 4],
+    pub composite: bool,
+}
+
+/// [`MarksPlan`] of Audio Spectrum or Audio Waveform on `b`'s geometry (`None` = no audio:
+/// the layer passes through).
+pub fn marks_plan(id: &str, ctx: &EffectCtx, b: &Buf) -> Option<MarksPlan> {
+    match id {
+        "ec.generate.audiospectrum" => spectrum_plan(ctx, b),
+        "ec.generate.audiowaveform" => waveform_plan(ctx, b),
+        _ => None,
+    }
+}
+
+fn marks(ctx: &EffectCtx, segs: Vec<Seg>, thick: f64, soft: f64) -> MarksPlan {
+    let pr = ctx.params;
+    MarksPlan {
+        segs,
+        thickness: thick,
+        softness: soft * 2.0,
+        inside: pr.color("insideColor"),
+        outside: pr.color("outsideColor"),
+        composite: pr.b("compositeOnOriginal"),
+    }
+}
+
+pub(super) fn audio_spectrum(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    if let Some(m) = spectrum_plan(ctx, &b) {
+        draw_marks(&mut b, &m.segs, m.thickness, m.softness, m.inside, m.outside, m.composite);
+    }
+    b
+}
+
+pub(super) fn audio_waveform(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    if let Some(m) = waveform_plan(ctx, &b) {
+        draw_marks(&mut b, &m.segs, m.thickness, m.softness, m.inside, m.outside, m.composite);
+    }
+    b
+}
+
+fn compute_fft_mags(samples: &[f64]) -> (usize, f64, Vec<f64>) {
+    let m = samples.len();
+    let n = m.next_power_of_two().max(64);
+    let mut re = vec![0.0; n];
+    let mut im = vec![0.0; n];
+    let denom = (m.max(2) - 1) as f64;
+    for (i, s) in samples.iter().enumerate() {
+        let w = 0.5 - 0.5 * (2.0 * PI * i as f64 / denom).cos();
+        if let Some(r) = re.get_mut(i) {
+            *r = s * w;
+        }
+    }
+    fft(&mut re, &mut im);
+    let hz_per_bin = AUDIO_RATE as f64 / n as f64;
+    let scale = 4.0 / m.max(1) as f64;
+    let num_bins = n / 2 + 1;
+    let mut mags = Vec::with_capacity(num_bins);
+    for k in 0..num_bins {
+        let r = re.get(k).copied().unwrap_or(0.0);
+        let im_val = im.get(k).copied().unwrap_or(0.0);
+        let mag = (r * r + im_val * im_val).sqrt() * scale;
+        mags.push(mag);
+    }
+    (n, hz_per_bin, mags)
+}
+
+fn spectrum_plan(ctx: &EffectCtx, b: &Buf) -> Option<MarksPlan> {
+    let pr = ctx.params;
+    let samples = audio_window(ctx, pr.f("audioDuration"), pr.f("audioOffset"), 0)?;
+    let (_n, hz_per_bin, mags) = compute_fft_mags(&samples);
+
+    let bands = pr.f("frequencyBands").round().clamp(1.0, 4096.0) as usize;
+    let f0 = pr.f("startFrequency").max(0.0);
+    let f1 = pr.f("endFrequency").max(f0 + 1.0);
+    let max_bin = mags.len().saturating_sub(1);
+
+    let get_band_mag = |fc: f64| -> f64 {
+        if mags.is_empty() || hz_per_bin <= 0.0 {
+            return 0.0;
+        }
+        let k_float = (fc / hz_per_bin).clamp(0.0, max_bin as f64);
+        let k0 = (k_float.floor() as usize).min(max_bin.saturating_sub(1));
+        let k1 = (k0 + 1).min(max_bin);
+        let frac = (k_float - k0 as f64).clamp(0.0, 1.0);
+        let m0 = mags.get(k0).copied().unwrap_or(0.0);
+        let m1 = mags.get(k1).copied().unwrap_or(0.0);
+        m0 * (1.0 - frac) + m1 * frac
+    };
+
+    let max_h = pr.f("maximumHeight") * b.scale;
+    let thick = (pr.f("thickness") * b.scale).max(0.1);
+    let soft = pr.f("softness") / 100.0;
+    let disp = pr.e("displayOptions");
+    let side = pr.e("sideOptions");
+    let base = Baseline::new(ctx, b);
+    let mut tops = Vec::with_capacity(bands);
+    let mut segs = Vec::new();
+    for i in 0..bands {
+        let u = if bands > 1 { i as f64 / (bands - 1) as f64 } else { 0.5 };
+        let fc = f0 + (f1 - f0) * u;
+        let v = get_band_mag(fc);
+        let hgt = if (v * max_h).is_finite() { (v * max_h).clamp(0.0, max_h.max(0.0)) } else { 0.0 };
+        let (q, nrm) = base.at(u);
+        let (ua, ub) = match side {
+            0 => (0.0, hgt),
+            1 => (-hgt, 0.0),
+            _ => (-hgt, hgt),
+        };
+        let pa = [q[0] + nrm[0] * ua, q[1] + nrm[1] * ua];
+        let pb = [q[0] + nrm[0] * ub, q[1] + nrm[1] * ub];
+        match disp {
+            0 => segs.push(Seg { a: pa, b: pb, r: thick * 0.5, v: 1.0 }),
+            _ => tops.push((pa, pb)),
+        }
+    }
+    if disp == 1 {
+        for w2 in tops.windows(2) {
+            segs.push(Seg { a: w2[0].1, b: w2[1].1, r: thick * 0.5, v: 1.0 });
+            if side == 2 {
+                segs.push(Seg { a: w2[0].0, b: w2[1].0, r: thick * 0.5, v: 1.0 });
+            }
+        }
+    } else if disp == 2 {
+        for &(pa, pb) in &tops {
+            segs.push(Seg { a: pb, b: pb, r: thick * 0.5, v: 1.0 });
+            if side == 2 {
+                segs.push(Seg { a: pa, b: pa, r: thick * 0.5, v: 1.0 });
+            }
+        }
+    }
+    Some(marks(ctx, segs, thick, soft))
+}
+
+fn waveform_plan(ctx: &EffectCtx, b: &Buf) -> Option<MarksPlan> {
+    let pr = ctx.params;
+    let samples = audio_window(ctx, pr.f("audioDuration"), pr.f("audioOffset"), pr.e("waveformOptions"))?;
+    let count = pr.f("displayedSamples").round().clamp(2.0, 4096.0) as usize;
+    let max_h = pr.f("maximumHeight") * b.scale;
+    let thick = (pr.f("thickness") * b.scale).max(0.1);
+    let soft = pr.f("softness") / 100.0;
+    let disp = pr.e("displayOptions");
+    let base = Baseline::new(ctx, b);
+    let m = samples.len();
+    let mut pts = Vec::with_capacity(count);
+    let mut segs = Vec::new();
+    for i in 0..count {
+        let u = i as f64 / (count - 1) as f64;
+        let a = ((u * (m - 1) as f64) as usize).min(m - 1);
+        let bnd = (((i + 1) as f64 / count as f64 * (m - 1) as f64) as usize).clamp(a, m - 1);
+        // Peak with sign of the window for a stable digital display.
+        let (mut lo, mut hi) = (0.0f64, 0.0f64);
+        for s in &samples[a..=bnd] {
+            lo = lo.min(*s);
+            hi = hi.max(*s);
+        }
+        let (q, nrm) = base.at(u);
+        match disp {
+            0 => segs.push(Seg {
+                a: [q[0] + nrm[0] * lo * max_h, q[1] + nrm[1] * lo * max_h],
+                b: [q[0] + nrm[0] * hi * max_h, q[1] + nrm[1] * hi * max_h],
+                r: thick * 0.5,
+                v: 1.0,
+            }),
+            _ => {
+                let v = samples[a] * max_h;
+                pts.push([q[0] + nrm[0] * v, q[1] + nrm[1] * v]);
+            }
+        }
+    }
+    if disp == 1 {
+        poly_segs(&pts, false, thick * 0.5, 1.0, &mut segs);
+    } else if disp == 2 {
+        segs.extend(pts.iter().map(|&q| Seg { a: q, b: q, r: thick * 0.5, v: 1.0 }));
+    }
+    Some(marks(ctx, segs, thick, soft))
+}
diff --git a/crates/effects/src/generate3/common.rs b/crates/effects/src/generate3/common.rs
new file mode 100644
index 000000000..7e341ad8d
--- /dev/null
+++ b/crates/effects/src/generate3/common.rs
@@ -0,0 +1,13 @@
+use super::{EffectSpec, ParamUi, Value, slider};
+
+pub(super) fn spec(id: &'static str, name: &'static str, params: Vec<crate::ParamSpec>, render: crate::RenderFn) -> EffectSpec {
+    EffectSpec { id, name, category: "Generate", params, render, gpu: false, float: true }
+}
+
+pub(super) fn pt(x: f64, y: f64) -> Value {
+    Value::Vec2([x, y])
+}
+
+pub(super) fn pct() -> ParamUi {
+    slider(0.0, 100.0, 0.0, 100.0, 1)
+}
diff --git a/crates/effects/src/generate3/fill.rs b/crates/effects/src/generate3/fill.rs
new file mode 100644
index 000000000..5df782a89
--- /dev/null
+++ b/crates/effects/src/generate3/fill.rs
@@ -0,0 +1,337 @@
+use super::raster::over;
+use super::{
+    Buf, EffectCtx, IndexedParallelIterator, IntoParallelRefIterator, IntoParallelRefMutIterator, PI, ParallelIterator, Plane, Px, gauss_plane, hash1,
+    hsl_to_rgb, morph_frac, premul, rgb_to_hsl, smoothstep, unpremul,
+};
+
+pub(super) fn glue_gun(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let pr = ctx.params;
+    let q = b.to_px(pr.v2("brushPosition"));
+    let rad = (pr.f("strokeWidth") * b.scale * 0.5).max(0.5);
+    let density = pr.f("density").max(0.0);
+    let refl = pr.f("reflection").to_radians();
+    let strength = (pr.f("strength") / 100.0) as f32;
+    let glue_only = pr.e("style") == 1;
+    let src = b.img.clone();
+    let light = [refl.cos() * 0.6, -refl.sin() * 0.6, 0.53];
+    let beads = (density.round() as usize).clamp(1, 32);
+    let seed = ctx.seed;
+    let centers: Vec<([f64; 2], f64)> = (0..beads)
+        .map(|i| {
+            let a = hash1(i as u32, 1, seed) as f64 * 2.0 * PI;
+            let d = if i == 0 { 0.0 } else { hash1(i as u32, 2, seed) as f64 * rad * 0.35 };
+            ([q.0 + a.cos() * d, q.1 + a.sin() * d], rad * (0.75 + 0.25 * hash1(i as u32, 3, seed) as f64))
+        })
+        .collect();
+    b.img.rows_mut().for_each(|(y, row)| {
+        for (x, px) in row.iter_mut().enumerate() {
+            let (fx, fy) = (x as f64 + 0.5, y as f64 + 0.5);
+            // Height field: union of hemispheres.
+            let mut best = (0.0f64, [0.0f64; 2], 1.0f64);
+            for &(c, r) in &centers {
+                let (dx, dy) = ((fx - c[0]) / r, (fy - c[1]) / r);
+                let d2 = dx * dx + dy * dy;
+                if d2 < 1.0 {
+                    let hgt = (1.0 - d2).sqrt();
+                    if hgt > best.0 {
+                        best = (hgt, [dx, dy], r);
+                    }
+                }
+            }
+            if best.0 <= 0.0 {
+                if glue_only {
+                    *px = [0.0; 4];
+                }
+                continue;
+            }
+            let nrm = [best.1[0], best.1[1], best.0];
+            let ndl = (nrm[0] * light[0] + nrm[1] * light[1] + nrm[2] * light[2]).max(0.0);
+            let spec = ndl.powi(24) as f32;
+            // Refraction: look through the bead.
+            let s = src.sample_bilinear_clamped(fx - nrm[0] * best.2 * 0.5 * strength as f64, fy - nrm[1] * best.2 * 0.5 * strength as f64);
+            let edge = smoothstep(0.0, 0.15, best.0 as f32);
+            let shade = 0.65 + 0.35 * ndl as f32;
+            let g = [s[0] * shade + spec, s[1] * shade + spec, s[2] * shade + spec, s[3].max(0.6)];
+            let gp = [g[0].min(g[3] + spec), g[1].min(g[3] + spec), g[2].min(g[3] + spec), g[3].min(1.0)];
+            let base = if glue_only { [0.0; 4] } else { *px };
+            *px = crate::util::lerp4(base, gp, edge * strength.clamp(0.0, 1.0).max(0.3));
+            px[3] = px[3].clamp(0.0, 1.0);
+        }
+    });
+    b
+}
+
+// ---------------------------------------------------------------- Paint Bucket
+
+/// Paint Bucket's filled region (1 inside) on `b`: the flood fill from the Fill Point over the
+/// layer's pixels (shared with the GPU compositor, which reads the layer back for it).
+pub fn paint_bucket_region(ctx: &EffectCtx, b: &Buf) -> Plane {
+    let pr = ctx.params;
+    let (w, h) = (b.img.width as usize, b.img.height as usize);
+    let fp = b.to_px(pr.v2("fillPoint"));
+    let (sx, sy) = (fp.0.floor() as i64, fp.1.floor() as i64);
+    let sel = pr.e("fillSelector");
+    let tol = (pr.f("tolerance") / 255.0) as f32;
+    let key = |p: Px| -> [f32; 4] {
+        let (c, a) = unpremul(p);
+        match sel {
+            1 => [c[0], c[1], c[2], 0.0],
+            2 => [0.0, 0.0, 0.0, if a <= 1e-3 { 0.0 } else { 1.0 }],
+            3 | 4 => [0.0, 0.0, 0.0, a],
+            _ => p,
+        }
+    };
+    let mut region = Plane::new(w, h);
+    if sx >= 0 && sy >= 0 && (sx as usize) < w && (sy as usize) < h {
+        let seed = key(b.img.data[sy as usize * w + sx as usize]);
+        let within = |i: usize| {
+            let k = key(b.img.data[i]);
+            if sel == 2 {
+                return k[3] == seed[3];
+            }
+            (0..4).all(|j| (k[j] - seed[j]).abs() <= tol + 1e-6)
+        };
+        let mut seen = vec![false; w * h];
+        let mut stack = vec![(sx as usize, sy as usize)];
+        while let Some((x, y)) = stack.pop() {
+            let row = y * w;
+            if seen[row + x] || !within(row + x) {
+                continue;
+            }
+            let mut l = x;
+            while l > 0 && !seen[row + l - 1] && within(row + l - 1) {
+                l -= 1;
+            }
+            let mut r = x;
+            while r + 1 < w && !seen[row + r + 1] && within(row + r + 1) {
+                r += 1;
+            }
+            for i in l..=r {
+                seen[row + i] = true;
+                region.data[row + i] = 1.0;
+                if y > 0 && !seen[row - w + i] {
+                    stack.push((i, y - 1));
+                }
+                if y + 1 < h && !seen[row + w + i] {
+                    stack.push((i, y + 1));
+                }
+            }
+        }
+    }
+    region
+}
+
+pub(super) fn paint_bucket(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let pr = ctx.params;
+    let (w, h) = (b.img.width as usize, b.img.height as usize);
+    if w == 0 || h == 0 {
+        return b;
+    }
+    let region = paint_bucket_region(ctx, &b);
+    if pr.b("viewThreshold") {
+        b.img.data.par_iter_mut().zip(region.data.par_iter()).for_each(|(px, &v)| *px = [v, v, v, 1.0]);
+        return b;
+    }
+    let sc = b.scale;
+    let mut cov = match pr.e("stroke") {
+        1 => {
+            let s = pr.f("featherSoftness") * sc * 0.5;
+            if s > 0.05 { gauss_plane(&region, s, s) } else { region.clone() }
+        }
+        2 => morph_frac(&region, pr.f("spreadRadius") * sc, true),
+        3 => morph_frac(&region, pr.f("spreadRadius") * sc, false),
+        4 => {
+            let r = pr.f("strokeWidth") * sc;
+            let out = morph_frac(&region, r * 0.5, true);
+            let inn = morph_frac(&region, r * 0.5, false);
+            out.zip_map(&inn, |a, b| (a - b).max(0.0))
+        }
+        _ => gauss_plane(&region, 0.5, 0.5),
+    };
+    if pr.e("stroke") == 0 {
+        // Antialias: keep the hard interior, soften only the boundary.
+        cov = cov.zip_map(&region, |a, r| if r > 0.0 { a.max(0.5) } else { a });
+    }
+    let color = pr.color("color");
+    let op = (pr.f("opacity") / 100.0) as f32;
+    let mode = pr.e("blendingMode");
+    b.img.data.par_iter_mut().zip(cov.data.par_iter()).for_each(|(px, &c)| {
+        let k = (c * op * color[3]).clamp(0.0, 1.0);
+        if k <= 0.0 {
+            if mode == 9 {
+                *px = [0.0; 4];
+            }
+            return;
+        }
+        let (dc, da) = unpremul(*px);
+        let fc = [color[0], color[1], color[2]];
+        let mixed = match mode {
+            1 => [dc[0] + fc[0], dc[1] + fc[1], dc[2] + fc[2]],
+            2 => [dc[0] * fc[0], dc[1] * fc[1], dc[2] * fc[2]],
+            3 => [1.0 - (1.0 - dc[0]) * (1.0 - fc[0]), 1.0 - (1.0 - dc[1]) * (1.0 - fc[1]), 1.0 - (1.0 - dc[2]) * (1.0 - fc[2])],
+            4..=7 => {
+                let (dh, ds, dl) = rgb_to_hsl(dc[0], dc[1], dc[2]);
+                let (fh, fs, fl) = rgb_to_hsl(fc[0], fc[1], fc[2]);
+                let (r, g, bl) = match mode {
+                    4 => hsl_to_rgb(fh, ds, dl),
+                    5 => hsl_to_rgb(dh, fs, dl),
+                    6 => hsl_to_rgb(fh, fs, dl),
+                    _ => hsl_to_rgb(dh, ds, fl),
+                };
+                [r, g, bl]
+            }
+            _ => fc,
+        };
+        *px = match mode {
+            8 => over(premul(fc, k), *px),
+            9 => premul(fc, k),
+            0 => over(*px, premul(fc, k)),
+            _ => {
+                if da <= 1e-6 {
+                    return;
+                }
+                let c3 = crate::util::lerp3(dc, mixed, k);
+                premul(c3, da)
+            }
+        };
+    });
+    b
+}
+
+// ---------------------------------------------------------------- Eyedropper Fill
+
+pub(super) fn eyedropper_fill(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let pr = ctx.params;
+    let fill = eyedropper_color(ctx, &b);
+    let keep_alpha = pr.b("maintainOriginalAlpha");
+    let blend = (pr.f("blendWithOriginal") / 100.0) as f32;
+    b.img.data.par_iter_mut().for_each(|px| {
+        let a = if keep_alpha { px[3] } else { fill[3] };
+        let f = premul([fill[0], fill[1], fill[2]], a);
+        *px = crate::util::lerp4(f, *px, blend);
+    });
+    b
+}
+
+/// Eyedropper Fill's sampled colour (straight RGB, alpha) from the layer's pixels (shared with
+/// the GPU compositor, which reads the layer back for it).
+pub fn eyedropper_color(ctx: &EffectCtx, b: &Buf) -> Px {
+    let pr = ctx.params;
+    let (w, h) = (b.img.width as i64, b.img.height as i64);
+    let c = b.to_px(pr.v2("samplePoint"));
+    let r = (pr.f("sampleRadius") * b.scale).max(0.0);
+    let mode = pr.e("averagePixelColors");
+    let (cx, cy) = (c.0.floor() as i64, c.1.floor() as i64);
+    let ri = r.ceil() as i64;
+    let mut acc = [0.0f64; 4];
+    let mut n = 0.0f64;
+    for y in (cy - ri).max(0)..=(cy + ri).min(h - 1) {
+        for x in (cx - ri).max(0)..=(cx + ri).min(w - 1) {
+            if ((x - cx).pow(2) + (y - cy).pow(2)) as f64 > r * r + 0.5 {
+                continue;
+            }
+            let px = b.img.data[(y * w + x) as usize];
+            match mode {
+                0 => {
+                    if px[3] > 1e-4 {
+                        let (s, _) = unpremul(px);
+                        for k in 0..3 {
+                            acc[k] += s[k] as f64;
+                        }
+                        acc[3] += 1.0;
+                        n += 1.0;
+                    }
+                }
+                1 => {
+                    let (s, _) = unpremul(px);
+                    for k in 0..3 {
+                        acc[k] += s[k] as f64;
+                    }
+                    acc[3] += 1.0;
+                    n += 1.0;
+                }
+                2 => {
+                    for k in 0..3 {
+                        acc[k] += px[k] as f64;
+                    }
+                    acc[3] += 1.0;
+                    n += 1.0;
+                }
+                _ => {
+                    for k in 0..4 {
+                        acc[k] += px[k] as f64;
+                    }
+                    n += 1.0;
+                }
+            }
+        }
+    }
+    if n > 0.0 {
+        if mode == 3 {
+            let a = (acc[3] / n) as f32;
+            let s = if a > 1e-6 { [(acc[0] / n) as f32 / a, (acc[1] / n) as f32 / a, (acc[2] / n) as f32 / a] } else { [0.0; 3] };
+            [s[0], s[1], s[2], a]
+        } else {
+            [(acc[0] / n) as f32, (acc[1] / n) as f32, (acc[2] / n) as f32, 1.0]
+        }
+    } else {
+        [0.0, 0.0, 0.0, 0.0]
+    }
+}
+
+// ---------------------------------------------------------------- CC Threads
+
+pub(super) fn threads(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let pr = ctx.params;
+    let sc = b.scale;
+    let tw = (pr.f("width") * sc).max(1.0);
+    let th = (pr.f("height") * sc).max(1.0);
+    let overlaps = pr.f("overlaps").round().clamp(1.0, 20.0) as i64;
+    let ang = pr.f("direction").to_radians();
+    let (sn, cs) = ang.sin_cos();
+    let c = b.to_px(pr.v2("center"));
+    let coverage = (pr.f("coverage") / 100.0).clamp(0.0, 1.0);
+    let shadow = (pr.f("shadowing") / 100.0) as f32;
+    let texture = (pr.f("texture") / 100.0) as f32;
+    let src = b.img.clone();
+    let to_px = |u: f64, v: f64| (c.0 + u * cs - v * sn, c.1 + u * sn + v * cs);
+    b.img.rows_mut().for_each(|(y, row)| {
+        for (x, px) in row.iter_mut().enumerate() {
+            let (dx, dy) = (x as f64 + 0.5 - c.0, y as f64 + 0.5 - c.1);
+            let u = dx * cs + dy * sn;
+            let v = -dx * sn + dy * cs;
+            let (ci, cj) = ((u / tw).floor() as i64, (v / th).floor() as i64);
+            let (fu, fv) = (u / tw - ci as f64, v / th - cj as f64);
+            // Horizontal thread j occupies the band |fv-0.5| < coverage/2; vertical thread i the
+            // band |fu-0.5| < coverage/2.
+            let in_h = (fv - 0.5).abs() < coverage * 0.5;
+            let in_v = (fu - 0.5).abs() < coverage * 0.5;
+            // Twill: horizontal is on top when (i + j) mod (2·overlaps) < overlaps.
+            let h_top = (ci + cj).rem_euclid(2 * overlaps) < overlaps;
+            let which = match (in_h, in_v) {
+                (true, true) => Some(h_top),
+                (true, false) => Some(true),
+                (false, true) => Some(false),
+                _ => None,
+            };
+            let Some(horizontal) = which else {
+                *px = [0.0; 4];
+                continue;
+            };
+            // Thread colour: the source sampled along the thread centre line.
+            let (sx, sy) = if horizontal { to_px(u, (cj as f64 + 0.5) * th) } else { to_px((ci as f64 + 0.5) * tw, v) };
+            let s = src.sample_bilinear_clamped(sx, sy);
+            // Round profile across the thread + darkening where it dives under its neighbour.
+            let across = if horizontal { (fv - 0.5) / (coverage * 0.5).max(1e-6) } else { (fu - 0.5) / (coverage * 0.5).max(1e-6) };
+            let along = if horizontal { fu } else { fv };
+            let profile = (1.0 - across * across).max(0.0).sqrt() as f32;
+            let dive = 1.0 - (along - 0.5).abs() as f32 * 2.0;
+            let shade = 1.0 - shadow * (1.0 - profile) * 0.8 - shadow * 0.25 * (1.0 - dive) * if horizontal == h_top { 0.0 } else { 1.0 };
+            let fib =
+                if texture > 0.0 { 1.0 - texture * 0.3 * hash1((along * 64.0) as u32, (across * 8.0 + 8.0) as u32, ci as u32 ^ (cj as u32) << 8) } else { 1.0 };
+            let k = (shade * fib).max(0.0);
+            *px = [s[0] * k, s[1] * k, s[2] * k, s[3]];
+        }
+    });
+    b
+}
diff --git a/crates/effects/src/generate3/fractal.rs b/crates/effects/src/generate3/fractal.rs
new file mode 100644
index 000000000..05a76d5f0
--- /dev/null
+++ b/crates/effects/src/generate3/fractal.rs
@@ -0,0 +1,193 @@
+use super::raster::over;
+use super::{Buf, EffectCtx, IndexedParallelIterator, ParallelIterator, ParallelSliceMut, Px, hsl_to_rgb};
+
+// ---------------------------------------------------------------- Fractal
+
+#[derive(Clone, Copy)]
+struct FracSet {
+    /// Mandelbrot iterations start at the Julia centre (the "Over Julia" set choices).
+    over_julia: bool,
+    julia: bool,
+    inverse: bool,
+}
+
+/// Smooth escape count, or `None` inside the set.
+fn escape(z0: (f64, f64), c: (f64, f64), power: u32, limit: f64, max_iter: u32) -> Option<f64> {
+    let (mut x, mut y) = z0;
+    let lim2 = limit * limit;
+    for i in 0..max_iter {
+        let (nx, ny) = match power {
+            3 => (x * x * x - 3.0 * x * y * y, 3.0 * x * x * y - y * y * y),
+            4 => {
+                let (a, b) = (x * x - y * y, 2.0 * x * y);
+                (a * a - b * b, 2.0 * a * b)
+            }
+            _ => (x * x - y * y, 2.0 * x * y),
+        };
+        x = nx + c.0;
+        y = ny + c.1;
+        let m2 = x * x + y * y;
+        if m2 > lim2 {
+            let lz = m2.ln() * 0.5;
+            let nu = (lz / limit.max(1.0001).ln()).max(1e-9).ln() / (power as f64).ln();
+            return Some((i as f64 + 1.0 - nu).max(0.0));
+        }
+    }
+    None
+}
+
+/// Fractal Set Choice options.
+pub(crate) const FRACTAL_SETS: [&str; 6] =
+    ["Mandelbrot", "Mandelbrot Inverse", "Mandelbrot Over Julia", "Mandelbrot Inverse Over Julia", "Julia", "Julia Inverse"];
+
+/// Fractal Palette options.
+pub(crate) const FRACTAL_PALETTES: [&str; 4] = ["Lightness Gradient", "Hue Wheel", "Black And White", "Solid Color"];
+
+/// Fractal Oversample Method options.
+pub(crate) const FRACTAL_OVERSAMPLE: [&str; 2] = ["Edge Detect-Fast-May Miss Pixels", "Brute Force-Slow-Every Pixel"];
+
+pub(super) fn fractal(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let pr = ctx.params;
+    let set_choice = pr.e("setChoice");
+    let power = 2 + pr.e("equation").min(2);
+    let mc = (pr.f("mandelbrot/mandelbrotX"), pr.f("mandelbrot/mandelbrotY"));
+    let mmag = pr.f("mandelbrot/mandelbrotMagnification");
+    let mlim = pr.f("mandelbrot/mandelbrotEscapeLimit").max(1.01);
+    let jc = (pr.f("julia/juliaX"), pr.f("julia/juliaY"));
+    let jmag = pr.f("julia/juliaMagnification");
+    let jlim = pr.f("julia/juliaEscapeLimit").max(1.01);
+    let post = (pr.f("postInversionOffset/postInversionX"), pr.f("postInversionOffset/postInversionY"));
+    let overlay = pr.b("fractalColor/overlay");
+    let transparency = pr.b("fractalColor/transparency");
+    let transparent_inside = transparency || overlay;
+    let palette = pr.e("fractalColor/palette");
+    let hue = (pr.f("fractalColor/hue") / 360.0) as f32;
+    let steps = pr.f("fractalColor/cycleSteps").max(1.0);
+    let cyc_off = pr.f("fractalColor/cycleOffset") / 360.0;
+    let edge = pr.b("fractalColor/edgeHighlight");
+    let every = pr.e("highQualitySettings/samplingMethod") == 1;
+    let factor = pr.f("highQualitySettings/samplingFactor").round().clamp(1.0, 9.0) as usize;
+    let (w, h) = (b.img.width as usize, b.img.height as usize);
+    let lw = ctx.layer_size[0].max(1.0);
+    let lh = ctx.layer_size[1].max(1.0);
+    let inv = 1.0 / b.scale.max(1e-9);
+    let (off_x, off_y) = (b.offset[0], b.offset[1]);
+    // FRACTAL_SETS order.
+    let set = |julia, inverse, over_julia| FracSet { over_julia, julia, inverse };
+    let sets: (FracSet, Option<FracSet>) = match set_choice {
+        1 => (set(false, true, false), None),
+        2 => (set(false, false, true), None),
+        3 => (set(false, true, true), None),
+        4 => (set(true, false, false), None),
+        5 => (set(true, true, false), None),
+        _ => (set(false, false, false), None),
+    };
+    let iter_for = |mag: f64| (96.0 + 48.0 * mag.max(0.0)).clamp(64.0, 3000.0) as u32;
+    let eval_set = |s: FracSet, lx: f64, ly: f64| -> Option<f64> {
+        let (center, mag, lim) = if s.julia { (jc, jmag, jlim) } else { (mc, mmag, mlim) };
+        let span = 3.5 / 2f64.powf(mag);
+        let mut u = (lx - lw * 0.5) / lw * span + center.0;
+        let mut v = (ly - lh * 0.5) / lw * span + center.1;
+        if s.inverse {
+            let d = (u * u + v * v).max(1e-12);
+            u = u / d + post.0;
+            v = -v / d + post.1;
+        }
+        if s.julia {
+            escape((u, v), mc, power, lim, iter_for(mag))
+        } else {
+            let z0 = if s.over_julia { jc } else { (0.0, 0.0) };
+            escape(z0, (u, v), power, lim, iter_for(mag))
+        }
+    };
+    let eval = |lx: f64, ly: f64| -> Option<f64> {
+        let a = eval_set(sets.0, lx, ly);
+        match (a, sets.1) {
+            (None, Some(s2)) => eval_set(s2, lx, ly),
+            _ => a,
+        }
+    };
+    let shade = |n: Option<f64>| -> Px {
+        // Solid Color: only the inside of the set is drawn (Transparency flips the sides).
+        if palette == 3 {
+            let (r, g, bl) = hsl_to_rgb(hue, 1.0, 0.5);
+            return if n.is_none() != transparency { [r, g, bl, 1.0] } else { [0.0; 4] };
+        }
+        let Some(n) = n else {
+            return if transparent_inside { [0.0; 4] } else { [0.0, 0.0, 0.0, 1.0] };
+        };
+        let u = n / steps + cyc_off;
+        let band = (u.rem_euclid(1.0)) as f32;
+        let (r, g, bl) = match palette {
+            // Hue Wheel: the full hue circle at full saturation and brightness.
+            1 => hsl_to_rgb((hue + band).rem_euclid(1.0), 1.0, 0.5),
+            // Black And White: alternating bands.
+            2 => {
+                let v = if (u.floor() as i64).rem_euclid(2) == 0 { 0.0 } else { 1.0 };
+                (v, v, v)
+            }
+            // Lightness Gradient: black → hue → white, the hue moving 45° each cycle.
+            _ => hsl_to_rgb((hue + u.floor() as f32 * 0.125).rem_euclid(1.0), 0.85, band.clamp(0.0, 1.0)),
+        };
+        let mut c = [r, g, bl];
+        if edge && n.fract() < 0.12 {
+            c = [c[0] * 0.4 + 0.6, c[1] * 0.4 + 0.6, c[2] * 0.4 + 0.6];
+        }
+        [c[0], c[1], c[2], 1.0]
+    };
+    // First pass: one sample per pixel.
+    let mut first: Vec<Option<f64>> = vec![None; w * h];
+    first.par_chunks_mut(w.max(1)).enumerate().for_each(|(y, row)| {
+        for (x, v) in row.iter_mut().enumerate() {
+            *v = eval((x as f64 + 0.5 - off_x) * inv, (y as f64 + 0.5 - off_y) * inv);
+        }
+    });
+    let src = if overlay { Some(b.img.clone()) } else { None };
+    b.img.rows_mut().for_each(|(y, row)| {
+        for (x, px) in row.iter_mut().enumerate() {
+            let here = first[y * w + x];
+            let needs_ss = factor > 1
+                && (every || {
+                    let mut diff = false;
+                    for (dx, dy) in [(-1i64, 0i64), (1, 0), (0, -1), (0, 1)] {
+                        let (nx, ny) = (x as i64 + dx, y as i64 + dy);
+                        if nx < 0 || ny < 0 || nx >= w as i64 || ny >= h as i64 {
+                            continue;
+                        }
+                        let o = first[ny as usize * w + nx as usize];
+                        diff |= match (here, o) {
+                            (Some(a), Some(c)) => (a - c).abs() > steps * 0.25,
+                            (None, None) => false,
+                            _ => true,
+                        };
+                    }
+                    diff
+                });
+            let c = if needs_ss {
+                let mut acc = [0.0f32; 4];
+                for sy in 0..factor {
+                    for sx in 0..factor {
+                        let fx = x as f64 + (sx as f64 + 0.5) / factor as f64;
+                        let fy = y as f64 + (sy as f64 + 0.5) / factor as f64;
+                        let s = shade(eval((fx - off_x) * inv, (fy - off_y) * inv));
+                        let a = s[3];
+                        for k in 0..3 {
+                            acc[k] += s[k] * a;
+                        }
+                        acc[3] += a;
+                    }
+                }
+                let n = (factor * factor) as f32;
+                [acc[0] / n, acc[1] / n, acc[2] / n, acc[3] / n]
+            } else {
+                let s = shade(here);
+                [s[0] * s[3], s[1] * s[3], s[2] * s[3], s[3]]
+            };
+            *px = match &src {
+                Some(o) => over(o.data[y * w + x], c),
+                None => c,
+            };
+        }
+    });
+    b
+}
diff --git a/crates/effects/src/generate3/paths.rs b/crates/effects/src/generate3/paths.rs
new file mode 100644
index 000000000..319368a82
--- /dev/null
+++ b/crates/effects/src/generate3/paths.rs
@@ -0,0 +1,556 @@
+use super::raster::{Seg, all_masks_px, chaikin, mask_px, over, poly_segs, raster_convex, raster_segs, scan_runs, stroke_outline, trim_poly};
+use super::{
+    Buf, EffectCtx, Image, IndexedParallelIterator, IntoParallelRefIterator, IntoParallelRefMutIterator, ParallelIterator, Params, Plane, gauss_plane, hash1,
+    layer_or_self, luminance, poly_length, smoothstep, unpremul,
+};
+
+/// How painted coverage meets the layer: 0 On Original Image, 1 On Transparent, 2 Reveal
+/// Original Image.
+pub(crate) fn paint(img: &mut Image, cov: &Plane, color: [f32; 4], opacity: f32, style: u32) {
+    img.data.par_iter_mut().zip(cov.data.par_iter()).for_each(|(px, &c)| {
+        let a = (c * opacity * color[3]).clamp(0.0, 1.0);
+        let s = [color[0] * a, color[1] * a, color[2] * a, a];
+        *px = match style {
+            1 => s,
+            2 => [px[0] * a, px[1] * a, px[2] * a, px[3] * a],
+            _ => over(*px, s),
+        };
+    });
+}
+
+/// Coverage of a plan-drawn generator: round-capped segments rasterised by `raster_segs`
+/// with `hardness`, or the union of convex polygons (`raster_convex`).
+#[derive(Clone, Debug)]
+pub enum Coverage {
+    Segs { segs: Vec<Seg>, hardness: f64 },
+    Convex(Vec<Vec<[f64; 2]>>),
+}
+
+impl Coverage {
+    fn raster(&self, w: usize, h: usize) -> Plane {
+        match self {
+            Coverage::Segs { segs, hardness } => raster_segs(w, h, segs, *hardness),
+            Coverage::Convex(polys) => raster_convex(w, h, polys),
+        }
+    }
+}
+
+/// Stroke, Scribble, Vegas and Write-on, shared with the GPU compositor (effectcraft-gpu
+/// `fx_gen2`): the coverage and how it is painted. `style` 0–2 as `paint` (On Original
+/// Image, On Transparent, Reveal Original Image), 3 = under the layer (Vegas' Composite Under).
+#[derive(Clone, Debug)]
+pub struct PaintPlan {
+    pub cov: Coverage,
+    pub color: [f32; 4],
+    pub opacity: f32,
+    pub style: u32,
+}
+
+/// Draw a [`PaintPlan`].
+fn draw_paint(b: &mut Buf, plan: &PaintPlan) {
+    let cov = plan.cov.raster(b.img.width as usize, b.img.height as usize);
+    if plan.style == 3 {
+        let color = plan.color;
+        b.img.data.par_iter_mut().zip(cov.data.par_iter()).for_each(|(px, &c)| {
+            let a = c * color[3];
+            *px = over([color[0] * a, color[1] * a, color[2] * a, a], *px);
+        });
+    } else {
+        paint(&mut b.img, &cov, plan.color, plan.opacity, plan.style);
+    }
+}
+
+/// Generators drawn from a plan that need the layer's own pixels (`b.img`) to build it.
+pub fn plan_reads_pixels(id: &str, ctx: &EffectCtx) -> bool {
+    match id {
+        // Image Contours read the layer itself when no (resolvable) Input Layer is chosen.
+        "ec.generate.vegas" => ctx.params.e("stroke") == 0,
+        "ec.generate.paintbucket" | "ec.generate.eyedropperfill" => true,
+        "ec.generate.advancedlightning" => ctx.params.f("alphaObstacle").clamp(-10.0, 10.0) != 0.0,
+        _ => false,
+    }
+}
+
+/// [`PaintPlan`] of Stroke, Scribble, Vegas or Write-on on `b`'s geometry (`b.img` is read
+/// only when [`plan_reads_pixels`]). `None`: Scribble without a usable mask (the layer is
+/// cleared when it composites On Transparent, else kept).
+pub fn paint_plan(id: &str, ctx: &EffectCtx, b: &Buf) -> Option<PaintPlan> {
+    match id {
+        "ec.generate.stroke" => Some(stroke_plan(ctx, b)),
+        "ec.generate.scribble" => scribble_plan(ctx, b),
+        "ec.generate.vegas" => Some(vegas_plan(ctx, b)),
+        "ec.generate.writeon" => Some(write_on_plan(ctx, b)),
+        _ => None,
+    }
+}
+
+/// Scribble's Composite as a `paint` style.
+pub fn scribble_style(ctx: &EffectCtx) -> u32 {
+    match ctx.params.e("composite") {
+        0 => 0,
+        2 => 2,
+        _ => 1,
+    }
+}
+
+pub(super) fn scribble(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    match scribble_plan(ctx, &b) {
+        Some(plan) => draw_paint(&mut b, &plan),
+        None if scribble_style(ctx) == 1 => b.img = Image::new(b.img.width, b.img.height),
+        None => {}
+    }
+    b
+}
+
+fn scribble_plan(ctx: &EffectCtx, b: &Buf) -> Option<PaintPlan> {
+    let pr = ctx.params;
+    let which = pr.e("scribble");
+    let polys: Vec<_> = if which == 0 { mask_px(ctx, b, pr.f("mask").round().max(1.0) as usize).into_iter().collect() } else { all_masks_px(ctx, b) };
+    let polys: Vec<_> = polys.into_iter().filter(|p| p.0.len() >= 3).map(|(p, c, i)| (p, c, i && which == 2)).collect();
+    let style = scribble_style(ctx);
+    if polys.is_empty() {
+        return None;
+    }
+    let sc = b.scale;
+    let fill = pr.e("fillType");
+    let ew = pr.f("edgeOptions/edgeWidth").max(0.1) * sc;
+    let ang = pr.f("angle").to_radians();
+    let d = [ang.cos(), ang.sin()];
+    let n = [-d[1], d[0]];
+    let width = (pr.f("strokeWidth") * sc).max(0.1);
+    let curv = pr.f("strokeOptions/curviness") / 100.0;
+    let curv_var = pr.f("strokeOptions/curvinessVariation") / 100.0;
+    let spacing = (pr.f("strokeOptions/spacing") * sc).max(0.75).max(width * 0.25);
+    let spacing_var = pr.f("strokeOptions/spacingVariation") / 100.0;
+    let overlap = pr.f("strokeOptions/pathOverlap") / 100.0;
+    let overlap_var = pr.f("strokeOptions/pathOverlapVariation") / 100.0;
+    let start = pr.f("start").clamp(0.0, 100.0) / 100.0;
+    let end = pr.f("end").clamp(0.0, 100.0) / 100.0;
+    let sequential = pr.b("fillPathsSequentially");
+    let wiggle = pr.e("wiggleType");
+    let wps = pr.f("wigglesPerSecond").max(0.0);
+    let seed = pr.f("randomSeed") as i64 as u32 ^ ctx.seed;
+    let (step, frac) = match wiggle {
+        0 => (0u32, 0.0f32),
+        1 => ((ctx.time * wps).floor().max(0.0) as u32, 0.0),
+        _ => {
+            let u = (ctx.time * wps).max(0.0);
+            (u.floor() as u32, smoothstep(0.0, 1.0, u.fract() as f32))
+        }
+    };
+    let rnd = |i: u32, k: u32| {
+        let a = hash1(i, k.wrapping_mul(31).wrapping_add(step.wrapping_mul(7919)), seed) * 2.0 - 1.0;
+        if frac > 0.0 {
+            let c = hash1(i, k.wrapping_mul(31).wrapping_add((step + 1).wrapping_mul(7919)), seed) * 2.0 - 1.0;
+            a + (c - a) * frac
+        } else {
+            a
+        }
+    };
+    let groups: Vec<Vec<(Vec<[f64; 2]>, bool, bool)>> =
+        if which == 0 || sequential { vec![polys.clone()] } else { polys.iter().map(|p| vec![p.clone()]).collect() };
+    // Per group a zig-zag polyline (in buffer px).
+    let mut lines: Vec<Vec<Vec<[f64; 2]>>> = Vec::new();
+    let mut runs = Vec::new();
+    for (gi, g) in groups.iter().enumerate() {
+        let mut nmin = f64::INFINITY;
+        let mut nmax = f64::NEG_INFINITY;
+        for (pts, _, _) in g {
+            for q in pts {
+                let v = q[0] * n[0] + q[1] * n[1];
+                nmin = nmin.min(v);
+                nmax = nmax.max(v);
+            }
+        }
+        nmin -= ew;
+        nmax += ew;
+        // Chains of zig-zags: each run joins the nearest chain that ended on the previous
+        // scan line (so separate regions get separate strokes).
+        let mut chains: Vec<(Vec<[f64; 2]>, u32)> = Vec::new();
+        let mut s = nmin + spacing * 0.5;
+        let mut li = 0u32;
+        let reach = spacing * 3.0 + ew;
+        while s < nmax && li < 20_000 {
+            scan_runs(g, fill, ew, d, n, s, &mut runs);
+            for (ri, &(a, bb)) in runs.iter().enumerate() {
+                let k = (gi as u32) << 20 | ri as u32;
+                let ov = spacing * (overlap + overlap_var * rnd(li, k * 4) as f64 * 0.5).max(-0.45);
+                let ov2 = spacing * (overlap + overlap_var * rnd(li, k * 4 + 1) as f64 * 0.5).max(-0.45);
+                let (a, bb) = (a - ov, bb + ov2);
+                if bb <= a {
+                    continue;
+                }
+                let at = |t: f64| [d[0] * t + n[0] * s, d[1] * t + n[1] * s];
+                let (pa, pb) = (at(a), at(bb));
+                let dist = |p: [f64; 2], q: [f64; 2]| ((p[0] - q[0]).powi(2) + (p[1] - q[1]).powi(2)).sqrt();
+                let best = chains
+                    .iter()
+                    .enumerate()
+                    .filter(|(_, c)| li > 0 && c.1 == li - 1)
+                    .map(|(i, c)| {
+                        let last = *c.0.last().unwrap_or(&pa);
+                        (i, dist(last, pa).min(dist(last, pb)))
+                    })
+                    .filter(|&(_, dd)| dd < reach)
+                    .min_by(|x, y| x.1.total_cmp(&y.1));
+                match best {
+                    Some((ci, _)) => {
+                        let last = *chains[ci].0.last().unwrap_or(&pa);
+                        let (p0, p1, dir) = if dist(last, pa) <= dist(last, pb) { (pa, pb, -1.0) } else { (pb, pa, 1.0) };
+                        // Curved turn: an extra point pushed past the edge.
+                        let c = (curv + curv_var * rnd(li, k * 4 + 2) as f64 * 0.5).max(0.0);
+                        let mid = [(last[0] + p0[0]) * 0.5 + d[0] * dir * c * spacing, (last[1] + p0[1]) * 0.5 + d[1] * dir * c * spacing];
+                        let ch = &mut chains[ci];
+                        ch.0.extend([mid, p0, p1]);
+                        ch.1 = li;
+                    }
+                    None => chains.push((vec![pa, pb], li)),
+                }
+            }
+            s += spacing * (1.0 + spacing_var * rnd(li, 3) as f64 * 0.5).max(0.25);
+            li += 1;
+        }
+        lines.push(chains.into_iter().map(|(z, _)| if curv > 0.0 { chaikin(&z, 2) } else { z }).collect());
+    }
+    let r = width * 0.5;
+    // Start / End Apply To: all of a mask's strokes as one path, or each stroke on its own.
+    let each = pr.e("startEndApplyTo") == 1;
+    let mut parts: Vec<Vec<[f64; 2]>> = Vec::new();
+    for group in &lines {
+        let lens: Vec<f64> = group.iter().map(|l| poly_length(l, false)).collect();
+        let total: f64 = lens.iter().sum();
+        let (g0, g1) = (total * start, total * end);
+        let mut acc = 0.0;
+        for (l, len) in group.iter().zip(lens) {
+            let part =
+                if each { trim_poly(l, false, len * start, len * end) } else { trim_poly(l, false, (g0 - acc).clamp(0.0, len), (g1 - acc).clamp(0.0, len)) };
+            acc += len;
+            parts.push(part);
+        }
+    }
+    let cap = pr.e("edgeOptions/endCap");
+    let join = pr.e("edgeOptions/join");
+    let cov = if cap == 0 && join == 0 {
+        let mut segs = Vec::new();
+        for part in &parts {
+            poly_segs(part, false, r, 1.0, &mut segs);
+        }
+        Coverage::Segs { segs, hardness: 0.9 }
+    } else {
+        Coverage::Convex(stroke_outline(&parts, r, cap, join, pr.f("edgeOptions/miterLimit").max(1.0)))
+    };
+    Some(PaintPlan { cov, color: pr.color("color"), opacity: (pr.f("opacity") / 100.0) as f32, style })
+}
+
+// ---------------------------------------------------------------- Stroke
+
+pub(super) fn stroke(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let plan = stroke_plan(ctx, &b);
+    draw_paint(&mut b, &plan);
+    b
+}
+
+fn stroke_plan(ctx: &EffectCtx, b: &Buf) -> PaintPlan {
+    let pr = ctx.params;
+    let all = pr.b("allMasks");
+    let polys: Vec<_> = if all { all_masks_px(ctx, b) } else { mask_px(ctx, b, pr.f("path").round() as usize).into_iter().collect() };
+    let style = pr.e("paintStyle");
+    let size = (pr.f("brushSize") * b.scale).max(0.1);
+    let r = size * 0.5;
+    let hard = pr.f("brushHardness") / 100.0;
+    let start = pr.f("start").clamp(0.0, 100.0) / 100.0;
+    let end = pr.f("end").clamp(0.0, 100.0) / 100.0;
+    let spacing = pr.f("spacing") / 100.0;
+    let sequential = pr.b("strokeSequentially");
+    let lens: Vec<f64> = polys.iter().map(|(p, c, _)| poly_length(p, *c)).collect();
+    let total: f64 = lens.iter().sum();
+    let mut segs = Vec::new();
+    let mut acc = 0.0;
+    for ((pts, closed, _), &len) in polys.iter().zip(&lens) {
+        let (s0, s1) = if all && sequential {
+            let (g0, g1) = (total * start, total * end);
+            ((g0 - acc).clamp(0.0, len), (g1 - acc).clamp(0.0, len))
+        } else {
+            (len * start, len * end)
+        };
+        acc += len;
+        if s1 <= s0 {
+            continue;
+        }
+        if spacing <= 0.5 {
+            let part = trim_poly(pts, *closed, s0, s1);
+            poly_segs(&part, false, r, 1.0, &mut segs);
+        } else {
+            let step = (size * spacing).max(0.5);
+            let mut s = s0;
+            while s <= s1 + 1e-9 && segs.len() < 200_000 {
+                let (q, _) = crate::util::poly_point_at(pts, *closed, s);
+                segs.push(Seg { a: q, b: q, r, v: 1.0 });
+                s += step;
+            }
+        }
+    }
+    PaintPlan { cov: Coverage::Segs { segs, hardness: hard }, color: pr.color("color"), opacity: (pr.f("opacity") / 100.0) as f32, style }
+}
+
+// ---------------------------------------------------------------- Vegas
+
+/// Marching-squares iso-contours of `pl` at `thr`, chained into polylines (closed flag).
+pub(super) fn contours(pl: &Plane, thr: f32) -> Vec<(Vec<[f64; 2]>, bool)> {
+    use std::collections::HashMap;
+    let (w, h) = (pl.w, pl.h);
+    if w < 2 || h < 2 {
+        return Vec::new();
+    }
+    // Edge key: horizontal edge (x,y)-(x+1,y) = 2*(y*w+x), vertical (x,y)-(x,y+1) = 2*(y*w+x)+1.
+    let hk = |x: usize, y: usize| 2 * (y * w + x) as u64;
+    let vk = |x: usize, y: usize| 2 * (y * w + x) as u64 + 1;
+    let mut pos: HashMap<u64, [f64; 2]> = HashMap::new();
+    let mut adj: HashMap<u64, Vec<u64>> = HashMap::new();
+    let v = |x: usize, y: usize| pl.data[y * w + x];
+    let interp = |a: f32, b: f32| if (b - a).abs() > 1e-9 { ((thr - a) / (b - a)).clamp(0.0, 1.0) as f64 } else { 0.5 };
+    for y in 0..h - 1 {
+        for x in 0..w - 1 {
+            let (a, bb, c, d) = (v(x, y), v(x + 1, y), v(x + 1, y + 1), v(x, y + 1));
+            let idx = (a > thr) as u8 | ((bb > thr) as u8) << 1 | ((c > thr) as u8) << 2 | ((d > thr) as u8) << 3;
+            if idx == 0 || idx == 15 {
+                continue;
+            }
+            // Edge points (pixel centres at +0.5).
+            let top = (hk(x, y), [x as f64 + 0.5 + interp(a, bb), y as f64 + 0.5]);
+            let right = (vk(x + 1, y), [x as f64 + 1.5, y as f64 + 0.5 + interp(bb, c)]);
+            let bottom = (hk(x, y + 1), [x as f64 + 0.5 + interp(d, c), y as f64 + 1.5]);
+            let left = (vk(x, y), [x as f64 + 0.5, y as f64 + 0.5 + interp(a, d)]);
+            let pairs: &[(usize, usize)] = match idx {
+                1 | 14 => &[(3, 0)],
+                2 | 13 => &[(0, 1)],
+                3 | 12 => &[(3, 1)],
+                4 | 11 => &[(1, 2)],
+                5 => &[(3, 0), (1, 2)],
+                6 | 9 => &[(0, 2)],
+                7 | 8 => &[(3, 2)],
+                10 => &[(0, 1), (2, 3)],
+                _ => &[],
+            };
+            let e = [top, right, bottom, left];
+            for &(i, j) in pairs {
+                pos.insert(e[i].0, e[i].1);
+                pos.insert(e[j].0, e[j].1);
+                adj.entry(e[i].0).or_default().push(e[j].0);
+                adj.entry(e[j].0).or_default().push(e[i].0);
+            }
+        }
+    }
+    let mut keys: Vec<u64> = adj.keys().copied().collect();
+    keys.sort_unstable();
+    // Start open chains at endpoints (degree 1) first, then closed loops.
+    keys.sort_by_key(|k| adj[k].len() != 1);
+    let mut used: std::collections::HashSet<(u64, u64)> = std::collections::HashSet::new();
+    let mut out = Vec::new();
+    for &k0 in &keys {
+        for &first in &adj[&k0] {
+            if used.contains(&(k0.min(first), k0.max(first))) {
+                continue;
+            }
+            let mut chain = vec![pos[&k0]];
+            let (mut prev, mut cur) = (k0, first);
+            used.insert((prev.min(cur), prev.max(cur)));
+            let mut closed = false;
+            loop {
+                chain.push(pos[&cur]);
+                if cur == k0 {
+                    closed = true;
+                    chain.pop();
+                    break;
+                }
+                let next = adj[&cur].iter().copied().find(|&n| n != prev && !used.contains(&(cur.min(n), cur.max(n))));
+                match next {
+                    Some(n) => {
+                        used.insert((cur.min(n), cur.max(n)));
+                        prev = cur;
+                        cur = n;
+                    }
+                    None => break,
+                }
+            }
+            if chain.len() >= 2 {
+                out.push((chain, closed));
+            }
+        }
+    }
+    out
+}
+
+pub(super) fn vegas(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let plan = vegas_plan(ctx, &b);
+    draw_paint(&mut b, &plan);
+    b
+}
+
+fn vegas_plan(ctx: &EffectCtx, b: &Buf) -> PaintPlan {
+    let pr = ctx.params;
+    let (w, h) = (b.img.width as usize, b.img.height as usize);
+    let sc = b.scale;
+    let paths: Vec<(Vec<[f64; 2]>, bool)> = if pr.e("stroke") == 1 {
+        mask_px(ctx, b, pr.f("path").round() as usize).map(|(p, c, _)| vec![(p, c)]).unwrap_or_default()
+    } else {
+        let src = layer_or_self(ctx, b, "inputLayer", true, pr.e("ifLayerSizesDiffer") == 1);
+        let ch = pr.e("channel");
+        let inv = pr.b("invertInput");
+        let mut pl = Plane::from_image(&src, |px| {
+            let (c, a) = unpremul(px);
+            let v = match ch {
+                1 => c[0],
+                2 => c[1],
+                3 => c[2],
+                4 => a,
+                _ => luminance(c[0], c[1], c[2]) * a,
+            };
+            if inv { 1.0 - v } else { v }
+        });
+        let blur = pr.f("preBlur") * sc;
+        if blur > 0.05 {
+            pl = gauss_plane(&pl, blur, blur);
+        }
+        let mut cs = contours(&pl, (pr.f("threshold") / 100.0) as f32);
+        // Simplify by tolerance (drop points closer than tol × size).
+        let tol = pr.f("tolerance").max(0.0) * (w.max(h) as f64) * 0.1;
+        if tol > 0.0 {
+            for (c, _) in cs.iter_mut() {
+                let mut keep: Vec<[f64; 2]> = Vec::with_capacity(c.len());
+                for &q in c.iter() {
+                    if keep.last().is_none_or(|l: &[f64; 2]| ((l[0] - q[0]).powi(2) + (l[1] - q[1]).powi(2)).sqrt() >= tol) {
+                        keep.push(q);
+                    }
+                }
+                *c = keep;
+            }
+        }
+        cs.sort_by(|a, b| poly_length(&b.0, b.1).total_cmp(&poly_length(&a.0, a.1)));
+        if pr.e("renderMode") == 1 {
+            let sel = (pr.f("selectedContour").round().max(1.0) as usize) - 1;
+            cs.into_iter().skip(sel).take(1).collect()
+        } else {
+            cs
+        }
+    };
+    let nseg = pr.f("segments").round().clamp(1.0, 1000.0) as usize;
+    // Shorter Contours Have Fewer Segments: segment count scales with contour length.
+    let fewer = pr.e("stroke") == 0 && pr.e("shorterContoursHave") == 1;
+    let longest = paths.iter().map(|(p, c)| poly_length(p, *c)).fold(0.0, f64::max);
+    let seg_len = pr.f("length").clamp(0.0, 1.0);
+    let bunched = pr.e("segmentDistribution") == 0;
+    let rot = pr.f("rotation") / 360.0;
+    let random_phase = pr.b("randomPhase");
+    let seed = pr.f("randomSeed") as i64 as u32 ^ ctx.seed;
+    let width = (pr.f("width") * sc).max(0.1);
+    let hard = pr.f("hardness").clamp(0.0, 1.0);
+    let (o0, om, o1, mp) = (pr.f("startOpacity") as f32, pr.f("midpointOpacity") as f32, pr.f("endOpacity") as f32, pr.f("midpointPosition").clamp(0.01, 0.99));
+    let mut segs = Vec::new();
+    for (ci, (pts, closed)) in paths.iter().enumerate() {
+        let len = poly_length(pts, *closed);
+        if len <= 0.0 {
+            continue;
+        }
+        let phase = rot + if random_phase { hash1(ci as u32, 1, seed) as f64 } else { 0.0 };
+        let nseg = if fewer && longest > 0.0 { ((nseg as f64 * len / longest).round() as usize).max(1) } else { nseg };
+        let each = len / nseg as f64 * seg_len;
+        for i in 0..nseg {
+            let base = if bunched { (i as f64 + (hash1(ci as u32, i as u32 + 7, seed) as f64 - 0.5) * 0.8) / nseg as f64 } else { i as f64 / nseg as f64 };
+            let s0 = (base + phase).rem_euclid(1.0) * len;
+            // Sub-sample the segment so opacity can ramp along it.
+            let sub = 12usize;
+            let mut prev: Option<[f64; 2]> = None;
+            for k in 0..=sub {
+                let f = k as f64 / sub as f64;
+                let mut s = s0 + each * f;
+                if *closed {
+                    s = s.rem_euclid(len);
+                } else if s > len {
+                    break;
+                }
+                let (q, _) = crate::util::poly_point_at(pts, *closed, s);
+                let op = if f < mp { o0 + (om - o0) * (f / mp) as f32 } else { om + (o1 - om) * ((f - mp) / (1.0 - mp)) as f32 };
+                if let Some(pv) = prev
+                    && ((pv[0] - q[0]).powi(2) + (pv[1] - q[1]).powi(2)) < (each * 0.5).powi(2) + 4.0
+                {
+                    segs.push(Seg { a: pv, b: q, r: width * 0.5, v: op.clamp(0.0, 1.0) });
+                }
+                prev = Some(q);
+            }
+        }
+    }
+    let style = match pr.e("blendMode") {
+        1 => 0,
+        2 => 3,
+        3 => 2,
+        _ => 1,
+    };
+    PaintPlan { cov: Coverage::Segs { segs, hardness: hard }, color: pr.color("color"), opacity: 1.0, style }
+}
+
+// ---------------------------------------------------------------- Write-on / Glue Gun
+
+/// Write-on draws a stroke along the animated Brush Position, as in After Effects: a dab every
+/// Brush Spacing seconds from the layer's start up to now, each one lasting Stroke Length
+/// seconds (0: for ever). The dabs' positions come from the host's parameters at their times;
+/// with Paint Time Properties ▸ Opacity or Brush Time Properties ▸ Size each dab keeps its own
+/// opacity or size, else the current ones apply to every dab. (Colour and hardness are one per
+/// stroke: the current ones.) Without a host (or dabs) the current dab draws. Deterministic.
+pub(super) fn write_on(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let plan = write_on_plan(ctx, &b);
+    draw_paint(&mut b, &plan);
+    b
+}
+
+/// The most dabs one Write-on frame draws; longer strokes lay them further apart, joined.
+const WRITE_ON_MAX_DABS: i64 = 4096;
+
+fn write_on_plan(ctx: &EffectCtx, b: &Buf) -> PaintPlan {
+    let pr = ctx.params;
+    let own_opacity = pr.e("paintTimeProperties") == 1;
+    let own_size = matches!(pr.e("brushTimeProperties"), 1 | 3);
+    let opacity = |p: &Params| (p.f("brushOpacity") / 100.0).clamp(0.0, 1.0) as f32;
+    let radius = |p: &Params| (p.f("brushSize") * b.scale * 0.5).max(0.05);
+    let dab = |p: &Params| {
+        let q = b.to_px(p.v2("brushPosition"));
+        ([q.0, q.1], radius(if own_size { p } else { pr }), if own_opacity { opacity(p) } else { 1.0 })
+    };
+    let mut segs = vec![];
+    let t = ctx.time;
+    let spacing = pr.f("brushSpacing").max(0.001);
+    let life = pr.f("strokeLength").max(0.0);
+    if let Some(host) = ctx.env.host
+        && t.is_finite()
+        && t >= 0.0
+    {
+        let start = if life > 0.0 { (t - life).max(0.0) } else { 0.0 };
+        let k0 = (start / spacing - 1e-9).ceil().max(0.0) as i64;
+        let k1 = (t / spacing + 1e-9).floor().max(0.0) as i64;
+        let n = k1.saturating_sub(k0).saturating_add(1);
+        let stride = (n / WRITE_ON_MAX_DABS).saturating_add(1).max(1);
+        let mut prev: Option<[f64; 2]> = None;
+        let mut k = k0;
+        while k <= k1 {
+            let tk = k as f64 * spacing;
+            let at = if (tk - t).abs() < 1e-9 { Some(dab(pr)) } else { host.params_at(tk).map(|p| dab(&p)) };
+            if let Some((q, r, v)) = at {
+                // Dabs laid further apart than the brush spacing are joined into a line.
+                let a = if stride > 1 { prev.unwrap_or(q) } else { q };
+                segs.push(Seg { a, b: q, r, v });
+                prev = Some(q);
+            }
+            k = k.saturating_add(stride);
+        }
+    }
+    if segs.is_empty() {
+        let (q, r, v) = dab(pr);
+        segs.push(Seg { a: q, b: q, r, v });
+    }
+    PaintPlan {
+        cov: Coverage::Segs { segs, hardness: pr.f("brushHardness") / 100.0 },
+        color: pr.color("color"),
+        opacity: if own_opacity { 1.0 } else { opacity(pr) },
+        style: pr.e("paintStyle"),
+    }
+}
diff --git a/crates/effects/src/generate3/raster.rs b/crates/effects/src/generate3/raster.rs
new file mode 100644
index 000000000..1b85818d0
--- /dev/null
+++ b/crates/effects/src/generate3/raster.rs
@@ -0,0 +1,368 @@
+use super::{Buf, EffectCtx, IndexedParallelIterator, ParallelIterator, ParallelSliceMut, Plane, Px, smoothstep};
+
+// ---------------------------------------------------------------- shared rasterisation
+
+/// A round-capped line segment in buffer pixels with radius `r` and intensity `v`.
+#[derive(Clone, Copy, Debug)]
+pub struct Seg {
+    pub a: [f64; 2],
+    pub b: [f64; 2],
+    pub r: f64,
+    pub v: f32,
+}
+
+/// Rasterise segments into a coverage plane (max-combined). `hardness` (0..1) is the fraction
+/// of the radius that is fully opaque; the rest falls off smoothly.
+pub(crate) fn raster_segs(w: usize, h: usize, segs: &[Seg], hardness: f64) -> Plane {
+    let mut out = Plane::new(w, h);
+    if w == 0 || h == 0 || segs.is_empty() {
+        return out;
+    }
+    let mut buckets: Vec<Vec<u32>> = vec![Vec::new(); h];
+    for (i, s) in segs.iter().enumerate() {
+        let pad = s.r + 1.0;
+        let y0 = (s.a[1].min(s.b[1]) - pad).floor().max(0.0) as usize;
+        let y1 = (s.a[1].max(s.b[1]) + pad).ceil().min(h as f64);
+        if y1 <= 0.0 || y0 >= h {
+            continue;
+        }
+        for row in buckets.iter_mut().take(y1 as usize).skip(y0) {
+            row.push(i as u32);
+        }
+    }
+    let hard = hardness.clamp(0.0, 1.0);
+    out.data.par_chunks_mut(w).enumerate().for_each(|(y, row)| {
+        let py = y as f64 + 0.5;
+        for &i in &buckets[y] {
+            let s = segs[i as usize];
+            let pad = s.r + 1.0;
+            let x0 = (s.a[0].min(s.b[0]) - pad).floor().max(0.0) as usize;
+            let x1 = ((s.a[0].max(s.b[0]) + pad).ceil().max(0.0) as usize).min(w);
+            let (dx, dy) = (s.b[0] - s.a[0], s.b[1] - s.a[1]);
+            let l2 = dx * dx + dy * dy;
+            let inner = s.r * hard - 0.5;
+            let outer = s.r + 0.5;
+            for (x, o) in row.iter_mut().enumerate().take(x1).skip(x0) {
+                let px = x as f64 + 0.5;
+                let t = if l2 > 1e-12 { (((px - s.a[0]) * dx + (py - s.a[1]) * dy) / l2).clamp(0.0, 1.0) } else { 0.0 };
+                let d = ((px - s.a[0] - dx * t).powi(2) + (py - s.a[1] - dy * t).powi(2)).sqrt();
+                if d >= outer {
+                    continue;
+                }
+                let c = if d <= inner { 1.0 } else { 1.0 - smoothstep(inner as f32, outer as f32, d as f32) } * s.v;
+                if c > *o {
+                    *o = c;
+                }
+            }
+        }
+    });
+    out
+}
+
+/// Segments along a polyline (buffer px).
+pub fn poly_segs(pts: &[[f64; 2]], closed: bool, r: f64, v: f32, out: &mut Vec<Seg>) {
+    let n = pts.len();
+    if n == 1 {
+        out.push(Seg { a: pts[0], b: pts[0], r, v });
+    }
+    if n < 2 {
+        return;
+    }
+    let segs = if closed { n } else { n - 1 };
+    for i in 0..segs {
+        out.push(Seg { a: pts[i], b: pts[(i + 1) % n], r, v });
+    }
+}
+
+/// Portion `[s0, s1]` (arc length) of a polyline.
+pub(crate) fn trim_poly(pts: &[[f64; 2]], closed: bool, s0: f64, s1: f64) -> Vec<[f64; 2]> {
+    let n = pts.len();
+    let mut out = Vec::new();
+    if n < 2 || s1 <= s0 {
+        return out;
+    }
+    let segs = if closed { n } else { n - 1 };
+    let mut acc = 0.0;
+    for i in 0..segs {
+        let (a, b) = (pts[i], pts[(i + 1) % n]);
+        let l = ((b[0] - a[0]).powi(2) + (b[1] - a[1]).powi(2)).sqrt();
+        let (e0, e1) = (acc, acc + l);
+        acc = e1;
+        if e1 < s0 || e0 > s1 || l <= 0.0 {
+            continue;
+        }
+        let at = |s: f64| {
+            let t = ((s - e0) / l).clamp(0.0, 1.0);
+            [a[0] + (b[0] - a[0]) * t, a[1] + (b[1] - a[1]) * t]
+        };
+        let p0 = at(s0.max(e0));
+        if out.last() != Some(&p0) {
+            out.push(p0);
+        }
+        out.push(at(s1.min(e1)));
+    }
+    out
+}
+
+#[inline]
+pub(super) fn over(dst: Px, src: Px) -> Px {
+    let k = 1.0 - src[3];
+    [src[0] + dst[0] * k, src[1] + dst[1] * k, src[2] + dst[2] * k, src[3] + dst[3] * k]
+}
+
+/// Mask `idx` (1-based; 0 = none) mapped to buffer pixels.
+pub(crate) fn mask_px(ctx: &EffectCtx, b: &Buf, idx: usize) -> Option<(Vec<[f64; 2]>, bool, bool)> {
+    let m = ctx.env.masks.get(idx.checked_sub(1)?)?;
+    if m.points.is_empty() {
+        return None;
+    }
+    Some((m.points.iter().map(|&q| [q[0] * b.scale + b.offset[0], q[1] * b.scale + b.offset[1]]).collect(), m.closed, m.inverted))
+}
+
+/// All masks mapped to buffer pixels.
+pub(super) fn all_masks_px(ctx: &EffectCtx, b: &Buf) -> Vec<(Vec<[f64; 2]>, bool, bool)> {
+    (1..=ctx.env.masks.len()).filter_map(|i| mask_px(ctx, b, i)).collect()
+}
+
+/// Chaikin corner cutting (open polyline, endpoints kept).
+pub(super) fn chaikin(pts: &[[f64; 2]], iters: usize) -> Vec<[f64; 2]> {
+    let mut cur = pts.to_vec();
+    for _ in 0..iters {
+        if cur.len() < 3 {
+            return cur;
+        }
+        let mut nx = Vec::with_capacity(cur.len() * 2);
+        nx.push(cur[0]);
+        for w in cur.windows(2) {
+            let (a, b) = (w[0], w[1]);
+            nx.push([a[0] * 0.75 + b[0] * 0.25, a[1] * 0.75 + b[1] * 0.25]);
+            nx.push([a[0] * 0.25 + b[0] * 0.75, a[1] * 0.25 + b[1] * 0.75]);
+        }
+        nx.push(*cur.last().unwrap_or(&[0.0; 2]));
+        cur = nx;
+    }
+    cur
+}
+
+// ---------------------------------------------------------------- Scribble
+
+/// Scan runs (start, end along direction `d`) of the fill region on the line `n·p = s`.
+pub(super) fn scan_runs(polys: &[(Vec<[f64; 2]>, bool, bool)], fill: u32, ew: f64, d: [f64; 2], n: [f64; 2], s: f64, out: &mut Vec<(f64, f64)>) {
+    out.clear();
+    for (pts, _closed, inverted) in polys {
+        let m = pts.len();
+        if m < 2 {
+            continue;
+        }
+        // Crossings: (t along d, |sin| of crossing angle).
+        let mut xs: Vec<(f64, f64)> = Vec::new();
+        for i in 0..m {
+            let (a, b) = (pts[i], pts[(i + 1) % m]);
+            let (na, nb) = (a[0] * n[0] + a[1] * n[1] - s, b[0] * n[0] + b[1] * n[1] - s);
+            if (na > 0.0) == (nb > 0.0) {
+                continue;
+            }
+            let t = na / (na - nb);
+            let q = [a[0] + (b[0] - a[0]) * t, a[1] + (b[1] - a[1]) * t];
+            let (ex, ey) = (b[0] - a[0], b[1] - a[1]);
+            let el = (ex * ex + ey * ey).sqrt().max(1e-9);
+            let sin = ((ex * n[0] + ey * n[1]) / el).abs().max(0.2);
+            xs.push((q[0] * d[0] + q[1] * d[1], sin));
+        }
+        xs.sort_by(|a, b| a.0.total_cmp(&b.0));
+        // Signed area decides which side is "left".
+        let area: f64 = (0..m).map(|i| pts[i][0] * pts[(i + 1) % m][1] - pts[(i + 1) % m][0] * pts[i][1]).sum();
+        let left_is_inside = area < 0.0;
+        let mode = match fill {
+            4 => {
+                if left_is_inside {
+                    2
+                } else {
+                    3
+                }
+            }
+            5 => {
+                if left_is_inside {
+                    3
+                } else {
+                    2
+                }
+            }
+            f => f,
+        };
+        let mode = if *inverted && mode == 0 { 6 } else { mode };
+        for (k, &(t, sin)) in xs.iter().enumerate() {
+            let entering = k % 2 == 0;
+            let l = ew / sin;
+            match mode {
+                0 if entering && k + 1 < xs.len() => {
+                    out.push((t, xs[k + 1].0));
+                }
+                1 => out.push((t - l * 0.5, t + l * 0.5)),
+                2 => out.push(if entering { (t, t + l) } else { (t - l, t) }),
+                3 => out.push(if entering { (t - l, t) } else { (t, t + l) }),
+                _ => {}
+            }
+        }
+        if mode == 6 {
+            // Inverted Inside: outside of the polygon within the bounds.
+            let lo = pts.iter().map(|q| q[0] * d[0] + q[1] * d[1]).fold(f64::INFINITY, f64::min) - ew;
+            let hi = pts.iter().map(|q| q[0] * d[0] + q[1] * d[1]).fold(f64::NEG_INFINITY, f64::max) + ew;
+            let mut cur = lo;
+            for pair in xs.chunks(2) {
+                out.push((cur, pair[0].0));
+                cur = pair.get(1).map(|v| v.0).unwrap_or(hi);
+            }
+            out.push((cur, hi));
+        }
+    }
+    out.sort_by(|a, b| a.0.total_cmp(&b.0));
+    // Merge overlaps.
+    let mut merged: Vec<(f64, f64)> = Vec::with_capacity(out.len());
+    for &(a, b) in out.iter() {
+        if let Some(last) = merged.last_mut()
+            && a <= last.1
+        {
+            last.1 = last.1.max(b);
+            continue;
+        }
+        merged.push((a, b));
+    }
+    *out = merged;
+}
+
+/// End Cap and Join options (Scribble's Edge Options).
+pub(super) const END_CAPS: [&str; 3] = ["Round", "Butt", "Projecting"];
+
+pub(super) const JOINS: [&str; 3] = ["Round", "Miter", "Bevel"];
+
+/// Convex polygons whose union is the stroke of the polylines `lines` with half width `r`:
+/// one quad per segment, plus the joins (Round discs, Miter wedges up to `miter_limit` × the
+/// half width, Bevel triangles) and the caps (Round discs, Butt none, Projecting square ends).
+pub(crate) fn stroke_outline(lines: &[Vec<[f64; 2]>], r: f64, cap: u32, join: u32, miter_limit: f64) -> Vec<Vec<[f64; 2]>> {
+    let disc = |c: [f64; 2]| -> Vec<[f64; 2]> {
+        (0..16).map(|k| (k as f64 / 16.0 * std::f64::consts::TAU).sin_cos()).map(|(s, co)| [c[0] + co * r, c[1] + s * r]).collect()
+    };
+    let mut out = Vec::new();
+    for l in lines {
+        let pts: Vec<[f64; 2]> = l.iter().copied().fold(Vec::new(), |mut v, p| {
+            if v.last().is_none_or(|q: &[f64; 2]| (q[0] - p[0]).hypot(q[1] - p[1]) > 1e-9) {
+                v.push(p);
+            }
+            v
+        });
+        if pts.len() < 2 {
+            if let (Some(p), 0) = (pts.first(), cap) {
+                out.push(disc(*p));
+            }
+            continue;
+        }
+        let dir = |a: [f64; 2], b: [f64; 2]| {
+            let (dx, dy) = (b[0] - a[0], b[1] - a[1]);
+            let l = dx.hypot(dy).max(1e-12);
+            [dx / l, dy / l]
+        };
+        let n = pts.len();
+        for k in 0..n - 1 {
+            let (mut a, mut b) = (pts[k], pts[k + 1]);
+            let d = dir(a, b);
+            // Projecting caps extend the end segments by the half width.
+            if cap == 2 && k == 0 {
+                a = [a[0] - d[0] * r, a[1] - d[1] * r];
+            }
+            if cap == 2 && k == n - 2 {
+                b = [b[0] + d[0] * r, b[1] + d[1] * r];
+            }
+            let nn = [-d[1] * r, d[0] * r];
+            out.push(vec![[a[0] + nn[0], a[1] + nn[1]], [b[0] + nn[0], b[1] + nn[1]], [b[0] - nn[0], b[1] - nn[1]], [a[0] - nn[0], a[1] - nn[1]]]);
+        }
+        // Joins.
+        for k in 1..n - 1 {
+            let (p, d0, d1) = (pts[k], dir(pts[k - 1], pts[k]), dir(pts[k], pts[k + 1]));
+            let cross = d0[0] * d1[1] - d0[1] * d1[0];
+            if cross.abs() < 1e-9 && d0[0] * d1[0] + d0[1] * d1[1] > 0.0 {
+                continue;
+            }
+            if join == 0 {
+                out.push(disc(p));
+                continue;
+            }
+            // The outer side of the turn.
+            let s = if cross > 0.0 { -1.0 } else { 1.0 };
+            let o0 = [p[0] - d0[1] * r * s, p[1] + d0[0] * r * s];
+            let o1 = [p[0] - d1[1] * r * s, p[1] + d1[0] * r * s];
+            let bevel = vec![p, o0, o1];
+            if join == 1 {
+                // Miter point: where the two offset edges meet.
+                let bis = [d0[0] - d1[0], d0[1] - d1[1]];
+                let bl = bis[0].hypot(bis[1]);
+                let cos_half = ((1.0 + d0[0] * d1[0] + d0[1] * d1[1]) * 0.5).max(0.0).sqrt();
+                let len = if cos_half > 1e-6 { r / cos_half } else { f64::INFINITY };
+                if bl > 1e-9 && len <= miter_limit * r {
+                    let m = [p[0] + (o0[0] + o1[0] - 2.0 * p[0]) * 0.5, p[1] + (o0[1] + o1[1] - 2.0 * p[1]) * 0.5];
+                    let ml = (m[0] - p[0]).hypot(m[1] - p[1]).max(1e-12);
+                    let tip = [p[0] + (m[0] - p[0]) / ml * len, p[1] + (m[1] - p[1]) / ml * len];
+                    out.push(vec![p, o0, tip, o1]);
+                    continue;
+                }
+            }
+            out.push(bevel);
+        }
+        if cap == 0 {
+            out.push(disc(pts[0]));
+            out.push(disc(pts[n - 1]));
+        }
+    }
+    out
+}
+
+/// Coverage (union, 4×4 samples per pixel) of convex polygons on a `w`×`h` grid.
+pub(crate) fn raster_convex(w: usize, h: usize, polys: &[Vec<[f64; 2]>]) -> Plane {
+    let mut out = Plane::new(w, h);
+    let inside = |poly: &[[f64; 2]], x: f64, y: f64| {
+        let n = poly.len();
+        let mut sign = 0.0;
+        for i in 0..n {
+            let (a, b) = (poly[i], poly[(i + 1) % n]);
+            let c = (b[0] - a[0]) * (y - a[1]) - (b[1] - a[1]) * (x - a[0]);
+            if c.abs() < 1e-12 {
+                continue;
+            }
+            if sign == 0.0 {
+                sign = c.signum();
+            } else if c.signum() != sign {
+                return false;
+            }
+        }
+        true
+    };
+    for poly in polys {
+        if poly.len() < 3 {
+            continue;
+        }
+        let (mut x0, mut y0, mut x1, mut y1) = (f64::INFINITY, f64::INFINITY, f64::NEG_INFINITY, f64::NEG_INFINITY);
+        for p in poly {
+            x0 = x0.min(p[0]);
+            y0 = y0.min(p[1]);
+            x1 = x1.max(p[0]);
+            y1 = y1.max(p[1]);
+        }
+        let (xa, xb) = (x0.floor().max(0.0) as usize, (x1.ceil().max(0.0) as usize).min(w));
+        let (ya, yb) = (y0.floor().max(0.0) as usize, (y1.ceil().max(0.0) as usize).min(h));
+        for y in ya..yb {
+            for x in xa..xb {
+                let mut hit = 0;
+                for sy in 0..4 {
+                    for sx in 0..4 {
+                        if inside(poly, x as f64 + (sx as f64 + 0.5) / 4.0, y as f64 + (sy as f64 + 0.5) / 4.0) {
+                            hit += 1;
+                        }
+                    }
+                }
+                let v = &mut out.data[y * w + x];
+                *v = v.max(hit as f32 / 16.0);
+            }
+        }
+    }
+    out
+}
diff --git a/crates/effects/src/generate3/registry.rs b/crates/effects/src/generate3/registry.rs
new file mode 100644
index 000000000..06c2b35fb
--- /dev/null
+++ b/crates/effects/src/generate3/registry.rs
@@ -0,0 +1,265 @@
+use super::audio::{audio_spectrum, audio_waveform};
+use super::common::{pct, pt, spec};
+use super::fill::{eyedropper_fill, glue_gun, paint_bucket, threads};
+use super::fractal::{FRACTAL_OVERSAMPLE, FRACTAL_PALETTES, FRACTAL_SETS, fractal};
+use super::paths::{scribble, stroke, vegas, write_on};
+use super::raster::{END_CAPS, JOINS};
+use super::{EffectSpec, ParamUi, Value, col, num, p, popup, slider};
+
+// ---------------------------------------------------------------- registry
+
+pub fn specs() -> Vec<EffectSpec> {
+    let ang = || ParamUi::Angle;
+    let check = |id: &'static str, name: &'static str, v: bool| p(id, name, Value::Bool(v), ParamUi::Checkbox);
+    let paint_style = || popup(&["On Original Image", "On Transparent", "Reveal Original Image"]);
+    let mask_idx = |id: &'static str, name: &'static str, d: f64| p(id, name, num(d), ParamUi::Mask);
+    let display = || popup(&["Digital", "Analog lines", "Analog dots"]);
+    vec![
+        spec(
+            "ec.generate.fractal",
+            "Fractal",
+            vec![
+                p("setChoice", "Set Choice", Value::Enum(0), popup(&FRACTAL_SETS)),
+                p("equation", "Equation", Value::Enum(0), popup(&["z = z^2 + c", "z = z^3 + c", "z = z^4 + c"])),
+                p("mandelbrot/mandelbrotX", "X (Real)", num(-0.74), slider(-2.0, 2.0, -2.0, 2.0, 4)),
+                p("mandelbrot/mandelbrotY", "Y (Imaginary)", num(0.15), slider(-2.0, 2.0, -2.0, 2.0, 4)),
+                p("mandelbrot/mandelbrotMagnification", "Magnification", num(0.0), slider(-5.0, 30.0, -5.0, 30.0, 2)),
+                p("mandelbrot/mandelbrotEscapeLimit", "Escape Limit", num(4.0), slider(1.0, 1000.0, 1.0, 100.0, 1)),
+                p("julia/juliaX", "X (Real)", num(0.0), slider(-2.0, 2.0, -2.0, 2.0, 4)),
+                p("julia/juliaY", "Y (Imaginary)", num(0.0), slider(-2.0, 2.0, -2.0, 2.0, 4)),
+                p("julia/juliaMagnification", "Magnification", num(0.0), slider(-5.0, 30.0, -5.0, 30.0, 2)),
+                p("julia/juliaEscapeLimit", "Escape Limit", num(4.0), slider(1.0, 1000.0, 1.0, 100.0, 1)),
+                p("postInversionOffset/postInversionX", "X Offset", num(0.0), slider(-2.0, 2.0, -2.0, 2.0, 4)),
+                p("postInversionOffset/postInversionY", "Y Offset", num(0.0), slider(-2.0, 2.0, -2.0, 2.0, 4)),
+                check("fractalColor/overlay", "Overlay", false),
+                check("fractalColor/transparency", "Transparency", false),
+                p("fractalColor/palette", "Palette", Value::Enum(0), popup(&FRACTAL_PALETTES)),
+                p("fractalColor/hue", "Hue", num(0.0), ang()),
+                p("fractalColor/cycleSteps", "Cycle Steps", num(32.0), slider(1.0, 1000.0, 1.0, 256.0, 0)),
+                p("fractalColor/cycleOffset", "Cycle Offset", num(0.0), ang()),
+                check("fractalColor/edgeHighlight", "Edge Highlight", false),
+                p("highQualitySettings/samplingMethod", "Oversample Method", Value::Enum(0), popup(&FRACTAL_OVERSAMPLE)),
+                p("highQualitySettings/samplingFactor", "Oversample Factor", num(2.0), slider(1.0, 9.0, 1.0, 9.0, 0)),
+            ],
+            fractal,
+        ),
+        spec(
+            "ec.generate.scribble",
+            "Scribble",
+            vec![
+                p("scribble", "Scribble", Value::Enum(0), popup(&["Single Mask", "All Masks", "All Masks Using Modes"])),
+                mask_idx("mask", "Mask", 1.0),
+                p("fillType", "Fill Type", Value::Enum(0), popup(&["Inside", "Centered Edge", "Inside Edge", "Outside Edge", "Left Edge", "Right Edge"])),
+                p("edgeOptions/edgeWidth", "Edge Width", num(10.0), slider(0.0, 1000.0, 0.0, 100.0, 1)),
+                p("edgeOptions/endCap", "End Cap", Value::Enum(0), popup(&END_CAPS)),
+                p("edgeOptions/join", "Join", Value::Enum(0), popup(&JOINS)),
+                p("edgeOptions/miterLimit", "Miter Limit", num(4.0), slider(1.0, 100.0, 1.0, 20.0, 1)),
+                p("color", "Color", col(1.0, 0.0, 0.0), ParamUi::Color),
+                p("opacity", "Opacity", num(100.0), pct()),
+                p("angle", "Angle", num(45.0), ang()),
+                p("strokeWidth", "Stroke Width", num(2.0), slider(0.1, 50.0, 0.1, 50.0, 1)),
+                p("strokeOptions/curviness", "Curviness", num(50.0), pct()),
+                p("strokeOptions/curvinessVariation", "Curviness Variation", num(50.0), pct()),
+                p("strokeOptions/spacing", "Spacing", num(5.0), slider(0.1, 100.0, 0.1, 50.0, 1)),
+                p("strokeOptions/spacingVariation", "Spacing Variation", num(50.0), pct()),
+                p("strokeOptions/pathOverlap", "Path Overlap", num(0.0), slider(-100.0, 100.0, -100.0, 100.0, 1)),
+                p("strokeOptions/pathOverlapVariation", "Path Overlap Variation", num(50.0), pct()),
+                p("start", "Start", num(0.0), pct()),
+                p("end", "End", num(100.0), pct()),
+                p("startEndApplyTo", "Start/End Apply To", Value::Enum(0), popup(&["All Strokes", "Each Stroke"])),
+                check("fillPathsSequentially", "Fill Paths Sequentially", true),
+                p("wiggleType", "Wiggle Type", Value::Enum(1), popup(&["Static", "Jumpy", "Smooth"])),
+                p("wigglesPerSecond", "Wiggles/Second", num(5.0), slider(0.0, 100.0, 0.0, 30.0, 2)),
+                p("randomSeed", "Random Seed", num(1.0), slider(0.0, 10000.0, 0.0, 100.0, 0)),
+                p("composite", "Composite", Value::Enum(1), popup(&["On Original Image", "On Transparent", "Reveal Original Image"])),
+            ],
+            scribble,
+        ),
+        spec(
+            "ec.generate.stroke",
+            "Stroke",
+            vec![
+                mask_idx("path", "Path", 1.0),
+                check("allMasks", "All Masks", false),
+                check("strokeSequentially", "Stroke Sequentially", true),
+                p("color", "Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("brushSize", "Brush Size", num(2.0), slider(0.0, 50.0, 0.0, 50.0, 1)),
+                p("brushHardness", "Brush Hardness", num(75.0), pct()),
+                p("opacity", "Opacity", num(100.0), pct()),
+                p("start", "Start", num(0.0), pct()),
+                p("end", "End", num(100.0), pct()),
+                p("spacing", "Spacing", num(15.0), slider(0.0, 100.0, 0.0, 100.0, 1)),
+                p("paintStyle", "Paint Style", Value::Enum(0), paint_style()),
+            ],
+            stroke,
+        ),
+        spec(
+            "ec.generate.vegas",
+            "Vegas",
+            vec![
+                p("stroke", "Stroke", Value::Enum(0), popup(&["Image Contours", "Mask/Path"])),
+                p("inputLayer", "Image Contours: Input Layer", Value::Layer(None), ParamUi::Layer),
+                check("invertInput", "Image Contours: Invert Input", false),
+                p("ifLayerSizesDiffer", "Image Contours: If Layer Sizes Differ", Value::Enum(0), popup(&["Center", "Stretch to Fit"])),
+                p("channel", "Image Contours: Channel", Value::Enum(0), popup(&["Intensity", "Red", "Green", "Blue", "Alpha"])),
+                p("threshold", "Image Contours: Threshold", num(50.0), pct()),
+                p("preBlur", "Image Contours: Pre-Blur", num(1.0), slider(0.0, 100.0, 0.0, 20.0, 1)),
+                p("tolerance", "Image Contours: Tolerance", num(0.01), slider(0.0, 1.0, 0.0, 0.1, 3)),
+                p("renderMode", "Image Contours: Render", Value::Enum(0), popup(&["All Contours", "Selected Contour"])),
+                p("selectedContour", "Image Contours: Selected Contour", num(1.0), slider(1.0, 1000.0, 1.0, 20.0, 0)),
+                p("shorterContoursHave", "Image Contours: Shorter Contours Have", Value::Enum(0), popup(&["Same Number of Segments", "Fewer Segments"])),
+                mask_idx("path", "Mask/Path: Path", 1.0),
+                p("segments", "Segments: Segments", num(32.0), slider(1.0, 1000.0, 1.0, 100.0, 0)),
+                p("length", "Segments: Length", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("segmentDistribution", "Segments: Segment Distribution", Value::Enum(0), popup(&["Bunched", "Even"])),
+                p("rotation", "Segments: Rotation", num(0.0), ang()),
+                check("randomPhase", "Segments: Random Phase", false),
+                p("randomSeed", "Segments: Random Seed", num(1.0), slider(1.0, 10000.0, 1.0, 100.0, 0)),
+                p("blendMode", "Rendering: Blend Mode", Value::Enum(1), popup(&["Transparent", "Over", "Under", "Stencil"])),
+                p("color", "Rendering: Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("width", "Rendering: Width", num(2.0), slider(0.0, 100.0, 0.0, 20.0, 2)),
+                p("hardness", "Rendering: Hardness", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("startOpacity", "Rendering: Start Opacity", num(1.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("midpointOpacity", "Rendering: Mid-point Opacity", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("midpointPosition", "Rendering: Mid-point Position", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("endOpacity", "Rendering: End Opacity", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
+            ],
+            vegas,
+        ),
+        spec(
+            "ec.generate.writeon",
+            "Write-on",
+            vec![
+                p("brushPosition", "Brush Position", pt(0.5, 0.5), ParamUi::Point),
+                p("color", "Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("brushSize", "Brush Size", num(6.0), slider(0.0, 50.0, 0.0, 50.0, 1)),
+                p("brushHardness", "Brush Hardness", num(75.0), pct()),
+                p("brushOpacity", "Brush Opacity", num(100.0), pct()),
+                p("strokeLength", "Stroke Length (secs)", num(0.0), slider(0.0, 30.0, 0.0, 30.0, 1)),
+                p("brushSpacing", "Brush Spacing (secs)", num(0.001), slider(0.001, 5.0, 0.001, 5.0, 3)),
+                p("paintTimeProperties", "Paint Time Properties", Value::Enum(0), popup(&["None", "Opacity", "Color"])),
+                p("brushTimeProperties", "Brush Time Properties", Value::Enum(0), popup(&["None", "Size", "Hardness", "Size & Hardness"])),
+                p("paintStyle", "Paint Style", Value::Enum(0), paint_style()),
+            ],
+            write_on,
+        ),
+        spec(
+            "ec.generate.paintbucket",
+            "Paint Bucket",
+            vec![
+                p("fillPoint", "Fill Point", pt(0.5, 0.5), ParamUi::Point),
+                p("fillSelector", "Fill Selector", Value::Enum(0), popup(&["Color & Alpha", "Straight Color", "Transparency", "Opacity", "Alpha Channel"])),
+                p("tolerance", "Tolerance", num(10.0), slider(0.0, 255.0, 0.0, 100.0, 1)),
+                check("viewThreshold", "View Threshold", false),
+                p("stroke", "Stroke", Value::Enum(0), popup(&["Antialias", "Feather", "Spread", "Choke", "Stroke"])),
+                p("featherSoftness", "Feather Softness", num(10.0), slider(0.0, 100.0, 0.0, 50.0, 1)),
+                p("spreadRadius", "Spread Radius", num(3.0), slider(0.0, 100.0, 0.0, 20.0, 1)),
+                p("strokeWidth", "Stroke Width", num(2.0), slider(0.0, 100.0, 0.0, 20.0, 1)),
+                p("color", "Color", col(1.0, 0.0, 0.0), ParamUi::Color),
+                p("opacity", "Opacity", num(100.0), pct()),
+                p(
+                    "blendingMode",
+                    "Blending Mode",
+                    Value::Enum(0),
+                    popup(&["Normal", "Add", "Multiply", "Screen", "Hue", "Saturation", "Color", "Luminosity", "Behind", "Fill Only"]),
+                ),
+            ],
+            paint_bucket,
+        ),
+        spec(
+            "ec.generate.eyedropperfill",
+            "Eyedropper Fill",
+            vec![
+                p("samplePoint", "Sample Point", pt(0.5, 0.5), ParamUi::Point),
+                p("sampleRadius", "Sample Radius", num(0.0), slider(0.0, 1000.0, 0.0, 100.0, 1)),
+                p("averagePixelColors", "Average Pixel Colors", Value::Enum(0), popup(&["Skip Empty", "All", "All Premultiplied", "Including Alpha"])),
+                check("maintainOriginalAlpha", "Maintain Original Alpha", false),
+                p("blendWithOriginal", "Blend With Original", num(0.0), pct()),
+            ],
+            eyedropper_fill,
+        ),
+        spec(
+            "ec.generate.ccgluegun",
+            "CC Glue Gun",
+            vec![
+                p("brushPosition", "Brush Position", pt(0.5, 0.5), ParamUi::Point),
+                p("strokeWidth", "Stroke Width", num(25.0), slider(0.0, 500.0, 0.0, 100.0, 1)),
+                p("density", "Density", num(5.0), slider(0.0, 32.0, 0.0, 32.0, 1)),
+                p("timeSpan", "Time Span (sec)", num(1.0), slider(0.0, 60.0, 0.0, 10.0, 2)),
+                p("reflection", "Reflection", num(45.0), ang()),
+                p("strength", "Strength", num(100.0), pct()),
+                p("style", "Style", Value::Enum(0), popup(&["Over Layer", "Glue Only"])),
+            ],
+            glue_gun,
+        ),
+        spec(
+            "ec.generate.ccthreads",
+            "CC Threads",
+            vec![
+                p("width", "Width", num(50.0), slider(1.0, 1000.0, 1.0, 200.0, 1)),
+                p("height", "Height", num(50.0), slider(1.0, 1000.0, 1.0, 200.0, 1)),
+                p("overlaps", "Overlaps", num(1.0), slider(1.0, 20.0, 1.0, 10.0, 0)),
+                p("direction", "Direction", num(0.0), ang()),
+                p("center", "Center", pt(0.5, 0.5), ParamUi::Point),
+                p("coverage", "Coverage", num(80.0), pct()),
+                p("shadowing", "Shadowing", num(50.0), pct()),
+                p("texture", "Texture", num(10.0), pct()),
+            ],
+            threads,
+        ),
+        spec(
+            "ec.generate.audiospectrum",
+            "Audio Spectrum",
+            vec![
+                p("audioLayer", "Audio Layer", Value::Layer(None), ParamUi::Layer),
+                p("startPoint", "Start Point", pt(0.1, 0.5), ParamUi::Point),
+                p("endPoint", "End Point", pt(0.9, 0.5), ParamUi::Point),
+                mask_idx("path", "Path", 0.0),
+                check("usePolarPath", "Use Polar Path", false),
+                p("startFrequency", "Start Frequency", num(20.0), slider(1.0, 20000.0, 1.0, 2000.0, 0)),
+                p("endFrequency", "End Frequency", num(2000.0), slider(1.0, 20000.0, 1.0, 10000.0, 0)),
+                p("frequencyBands", "Frequency bands", num(64.0), slider(1.0, 4096.0, 1.0, 256.0, 0)),
+                p("maximumHeight", "Maximum Height", num(50.0), slider(0.0, 10000.0, 0.0, 500.0, 1)),
+                p("audioDuration", "Audio Duration (milliseconds)", num(90.0), slider(1.0, 30000.0, 1.0, 1000.0, 1)),
+                p("audioOffset", "Audio Offset (milliseconds)", num(0.0), slider(-30000.0, 30000.0, -1000.0, 1000.0, 1)),
+                p("thickness", "Thickness", num(3.0), slider(0.0, 1000.0, 0.0, 50.0, 2)),
+                p("softness", "Softness", num(50.0), pct()),
+                p("insideColor", "Inside Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("outsideColor", "Outside Color", col(0.2, 0.4, 1.0), ParamUi::Color),
+                check("blendOverlappingColors", "Blend Overlapping Colors", true),
+                p("hueInterpolation", "Hue Interpolation", num(0.0), ang()),
+                check("dynamicHuePhase", "Dynamic Hue Phase", false),
+                check("colorSymmetry", "Color Symmetry", false),
+                p("displayOptions", "Display Options", Value::Enum(0), display()),
+                p("sideOptions", "Side Options", Value::Enum(0), popup(&["Side A", "Side B", "Side A & B"])),
+                check("durationAveraging", "Duration Averaging", false),
+                check("compositeOnOriginal", "Composite On Original", false),
+            ],
+            audio_spectrum,
+        ),
+        spec(
+            "ec.generate.audiowaveform",
+            "Audio Waveform",
+            vec![
+                p("audioLayer", "Audio Layer", Value::Layer(None), ParamUi::Layer),
+                p("startPoint", "Start Point", pt(0.1, 0.5), ParamUi::Point),
+                p("endPoint", "End Point", pt(0.9, 0.5), ParamUi::Point),
+                mask_idx("path", "Path", 0.0),
+                check("usePolarPath", "Use Polar Path", false),
+                p("displayedSamples", "Displayed Samples", num(200.0), slider(2.0, 4096.0, 2.0, 1000.0, 0)),
+                p("maximumHeight", "Maximum Height", num(100.0), slider(0.0, 10000.0, 0.0, 500.0, 1)),
+                p("audioDuration", "Audio Duration (milliseconds)", num(200.0), slider(1.0, 30000.0, 1.0, 1000.0, 1)),
+                p("audioOffset", "Audio Offset (milliseconds)", num(0.0), slider(-30000.0, 30000.0, -1000.0, 1000.0, 1)),
+                p("thickness", "Thickness", num(2.0), slider(0.0, 1000.0, 0.0, 50.0, 2)),
+                p("softness", "Softness", num(10.0), pct()),
+                p("randomSeed", "Random Seed (Analog)", num(1.0), slider(1.0, 10000.0, 1.0, 100.0, 0)),
+                p("insideColor", "Inside Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("outsideColor", "Outside Color", col(0.2, 0.4, 1.0), ParamUi::Color),
+                p("waveformOptions", "Waveform Options", Value::Enum(0), popup(&["Mono", "Left", "Right"])),
+                p("displayOptions", "Display Options", Value::Enum(1), display()),
+                check("compositeOnOriginal", "Composite On Original", false),
+            ],
+            audio_waveform,
+        ),
+    ]
+}
diff --git a/crates/effects/src/generate3/tests.rs b/crates/effects/src/generate3/tests.rs
new file mode 100644
index 000000000..0edad2f2d
--- /dev/null
+++ b/crates/effects/src/generate3/tests.rs
@@ -0,0 +1,397 @@
+use super::*;
+use crate::{EffectEnv, EffectHost, LayerPixels, MaskShape, Params};
+
+/// Run with point defaults scaled to the layer size.
+pub(crate) fn run_env(id: &str, set: &[(&str, Value)], img: Image, time: f64, env: EffectEnv) -> Buf {
+    let s = crate::find(id).unwrap();
+    let ls = [img.width as f64, img.height as f64];
+    let mut params = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+    for p in &s.params {
+        if let (ParamUi::Point, Value::Vec2(v)) = (&p.ui, &p.default) {
+            params.values.insert(p.id.to_string(), Value::Vec2([v[0] * ls[0], v[1] * ls[1]]));
+        }
+    }
+    for (k, v) in set {
+        assert!(params.values.contains_key(*k), "{id}: unknown {k}");
+        params.values.insert(k.to_string(), v.clone());
+    }
+    let ctx = EffectCtx { params: &params, time, layer_size: ls, seed: 3, adjustment: false, env };
+    crate::apply(s, &ctx, Buf { img, offset: [0.0, 0.0], scale: 1.0 })
+}
+
+fn run(id: &str, set: &[(&str, Value)], img: Image) -> Buf {
+    run_env(id, set, img, 0.5, EffectEnv::default())
+}
+
+fn square_mask() -> Vec<MaskShape> {
+    vec![MaskShape { name: "Mask 1".into(), points: vec![[16.0, 16.0], [48.0, 16.0], [48.0, 48.0], [16.0, 48.0]], closed: true, inverted: false }]
+}
+
+fn alpha_sum(img: &Image, x0: usize, y0: usize, x1: usize, y1: usize) -> f32 {
+    let mut s = 0.0;
+    for y in y0..y1 {
+        for x in x0..x1 {
+            s += img.data[y * img.width as usize + x][3];
+        }
+    }
+    s
+}
+
+#[test]
+fn audio_spectrum_linear_frequency_and_linear_amplitude() {
+    let host = Tone; // Tone produces 440 Hz
+    let env = EffectEnv { host: Some(&host), comp_time: 1.0, ..Default::default() };
+    let img = Image::new(200, 100);
+    let out = run_env(
+        "ec.generate.audiospectrum",
+        &[
+            ("audioLayer", Value::Layer(Some(1))),
+            ("startPoint", Value::Vec2([0.0, 50.0])),
+            ("endPoint", Value::Vec2([200.0, 50.0])),
+            ("startFrequency", num(20.0)),
+            ("endFrequency", num(2000.0)),
+            ("frequencyBands", num(100.0)),
+            ("maximumHeight", num(40.0)),
+            ("thickness", num(2.0)),
+            ("softness", num(0.0)),
+        ],
+        img,
+        1.0,
+        env,
+    );
+    // Verify 440 Hz tone produces a peak above baseline, while high frequencies have zero bar height
+    let peak_zone = alpha_sum(&out.img, 36, 10, 48, 48);
+    let high_zone = alpha_sum(&out.img, 120, 10, 150, 48);
+    let silent_zone = alpha_sum(&out.img, 170, 10, 195, 48);
+    assert!(peak_zone > 5.0, "peak zone has energy: {peak_zone}");
+    assert!(peak_zone > high_zone * 2.0, "linear peak is distinctly taller than far frequencies: {peak_zone} vs {high_zone}");
+    assert_eq!(silent_zone, 0.0, "silent end has zero height, not boosted by dB scale");
+}
+
+#[test]
+fn fractal_deterministic_and_has_inside_set() {
+    let img = Image::new(64, 48);
+    let a = run("ec.generate.fractal", &[], img.clone());
+    let b = run("ec.generate.fractal", &[], img.clone());
+    assert_eq!(a.img.data, b.img.data);
+    // The default view contains the main cardioid (black, opaque) and escaped (coloured) points.
+    assert!(a.img.data.iter().any(|p| p[3] > 0.99 && p[0] + p[1] + p[2] < 0.01));
+    assert!(a.img.data.iter().any(|p| p[0] + p[1] + p[2] > 0.3));
+    let t = run("ec.generate.fractal", &[("fractalColor/transparency", Value::Bool(true))], img);
+    assert!(t.img.data.iter().any(|p| p[3] == 0.0));
+}
+
+#[test]
+fn fractal_palettes_and_set_choices() {
+    let img = Image::new(64, 48);
+    // Solid Color: only the inside of the set is drawn; Transparency flips it.
+    let solid = run("ec.generate.fractal", &[("fractalColor/palette", Value::Enum(3))], img.clone());
+    assert!(solid.img.data.iter().any(|p| p[3] == 0.0) && solid.img.data.iter().any(|p| p[3] > 0.99 && p[0] > 0.9));
+    let flipped = run("ec.generate.fractal", &[("fractalColor/palette", Value::Enum(3)), ("fractalColor/transparency", Value::Bool(true))], img.clone());
+    for (a, b) in solid.img.data.iter().zip(&flipped.img.data) {
+        assert!((a[3] > 0.5) != (b[3] > 0.5) || (a[3] - 0.5).abs() < 0.49);
+    }
+    // Black And White: escaped pixels are pure black or white (away from supersampled edges).
+    let bw = run("ec.generate.fractal", &[("fractalColor/palette", Value::Enum(2)), ("highQualitySettings/samplingFactor", num(1.0))], img.clone());
+    assert!(bw.img.data.iter().all(|p| p[0] == p[1] && p[1] == p[2] && (p[0] == 0.0 || p[0] == 1.0)));
+    // Mandelbrot Over Julia depends on the Julia centre.
+    let o1 = run("ec.generate.fractal", &[("setChoice", Value::Enum(2)), ("julia/juliaX", num(0.3))], img.clone());
+    let o2 = run("ec.generate.fractal", &[("setChoice", Value::Enum(2)), ("julia/juliaX", num(-0.2))], img.clone());
+    assert_ne!(o1.img.data, o2.img.data);
+    let plain = run("ec.generate.fractal", &[("julia/juliaX", num(0.3))], img);
+    assert_ne!(o1.img.data, plain.img.data);
+}
+
+#[test]
+fn scribble_fills_mask_and_animates() {
+    let masks = square_mask();
+    let env = EffectEnv { masks: &masks, ..Default::default() };
+    let img = Image::filled(64, 64, [0.0, 0.0, 1.0, 1.0]);
+    let a = run_env("ec.generate.scribble", &[], img.clone(), 0.5, env);
+    let b = run_env("ec.generate.scribble", &[], img.clone(), 0.5, env);
+    assert_eq!(a.img.data, b.img.data);
+    let inside = alpha_sum(&a.img, 18, 18, 46, 46);
+    let outside = alpha_sum(&a.img, 0, 0, 10, 64);
+    assert!(inside > 100.0 && outside < 1.0, "{inside} {outside}");
+    let c = run_env("ec.generate.scribble", &[], img.clone(), 1.5, env);
+    assert_ne!(a.img.data, c.img.data, "jumpy wiggle changes over time");
+    let s = run_env("ec.generate.scribble", &[("wiggleType", Value::Enum(0))], img.clone(), 0.5, env);
+    let s2 = run_env("ec.generate.scribble", &[("wiggleType", Value::Enum(0))], img.clone(), 3.5, env);
+    assert_eq!(s.img.data, s2.img.data, "static wiggle is constant");
+    let half = run_env("ec.generate.scribble", &[("end", num(50.0))], img, 0.5, env);
+    assert!(alpha_sum(&half.img, 0, 0, 64, 64) < alpha_sum(&a.img, 0, 0, 64, 64));
+}
+
+#[test]
+fn scribble_edge_types() {
+    let masks = square_mask();
+    let env = EffectEnv { masks: &masks, ..Default::default() };
+    let img = Image::new(64, 64);
+    let o = run_env("ec.generate.scribble", &[("fillType", Value::Enum(3)), ("edgeOptions/edgeWidth", num(6.0))], img, 0.5, env);
+    // Outside edge: paint near the border outside, nothing in the centre.
+    assert!(alpha_sum(&o.img, 26, 26, 38, 38) < 0.5);
+    assert!(alpha_sum(&o.img, 8, 8, 16, 56) > 5.0);
+}
+
+#[test]
+fn stroke_draws_along_mask() {
+    let masks = square_mask();
+    let env = EffectEnv { masks: &masks, ..Default::default() };
+    let img = Image::new(64, 64);
+    let a = run_env("ec.generate.stroke", &[("brushSize", num(4.0)), ("paintStyle", Value::Enum(1))], img.clone(), 0.0, env);
+    assert!(a.img.get(32, 16)[3] > 0.9, "on the top edge");
+    assert!(a.img.get(32, 32)[3] < 0.01, "centre empty");
+    let b = run_env("ec.generate.stroke", &[("brushSize", num(4.0)), ("end", num(25.0))], img.clone(), 0.0, env);
+    assert!(b.img.get(32, 16)[3] > 0.9 && b.img.get(48, 32)[3] < 0.01, "first quarter only");
+    let d = run_env("ec.generate.stroke", &[("brushSize", num(4.0)), ("spacing", num(300.0))], img, 0.0, env);
+    assert!(alpha_sum(&d.img, 0, 0, 64, 64) < alpha_sum(&a.img, 0, 0, 64, 64), "spaced dabs");
+    // No masks: unchanged.
+    let src = Image::filled(8, 8, [0.2, 0.3, 0.4, 1.0]);
+    assert_eq!(run("ec.generate.stroke", &[], src.clone()).img.data, src.data);
+}
+
+#[test]
+fn vegas_traces_contours() {
+    let mut img = Image::new(64, 64);
+    for y in 16..48 {
+        for x in 16..48 {
+            img.set(x, y, [1.0, 1.0, 1.0, 1.0]);
+        }
+    }
+    let a =
+        run("ec.generate.vegas", &[("blendMode", Value::Enum(0)), ("length", num(1.0)), ("midpointOpacity", num(1.0)), ("endOpacity", num(1.0))], img.clone());
+    let b =
+        run("ec.generate.vegas", &[("blendMode", Value::Enum(0)), ("length", num(1.0)), ("midpointOpacity", num(1.0)), ("endOpacity", num(1.0))], img.clone());
+    assert_eq!(a.img.data, b.img.data);
+    assert!(alpha_sum(&a.img, 14, 14, 50, 50) > 50.0, "edges drawn");
+    assert!(alpha_sum(&a.img, 26, 26, 38, 38) < 0.5, "interior untouched");
+    let r = run("ec.generate.vegas", &[("blendMode", Value::Enum(0)), ("rotation", num(90.0))], img);
+    assert_ne!(r.img.data, a.img.data);
+}
+
+#[test]
+fn contours_of_square_are_closed() {
+    let mut pl = Plane::new(20, 20);
+    for y in 5..15 {
+        for x in 5..15 {
+            pl.data[y * 20 + x] = 1.0;
+        }
+    }
+    let c = contours(&pl, 0.5);
+    assert_eq!(c.len(), 1);
+    assert!(c[0].1);
+    let l = poly_length(&c[0].0, true);
+    assert!((l - 40.0).abs() < 4.0, "{l}");
+}
+
+#[test]
+fn write_on_and_glue_gun_draw_at_brush() {
+    let img = Image::new(32, 32);
+    let a = run("ec.generate.writeon", &[], img.clone());
+    assert!(a.img.get(16, 16)[3] > 0.9 && a.img.get(2, 2)[3] == 0.0);
+    assert_eq!(a.img.data, run("ec.generate.writeon", &[], img.clone()).img.data);
+    let src = Image::filled(32, 32, [0.5, 0.2, 0.1, 1.0]);
+    let g = run("ec.generate.ccgluegun", &[], src.clone());
+    assert_eq!(g.img.data, run("ec.generate.ccgluegun", &[], src.clone()).img.data);
+    assert_ne!(g.img.get(16, 16), src.get(16, 16));
+    assert_eq!(g.img.get(0, 0), src.get(0, 0));
+}
+
+/// #536: an animated Brush Position draws a stroke that stays (Stroke Length 0), expires
+/// after Stroke Length, and lays its dabs Brush Spacing seconds apart.
+#[test]
+fn write_on_accumulates_a_stroke_along_the_animated_brush() {
+    // Brush Position from [8, 16] at 0 s to [56, 16] at 1 s; red, hard, 6 px.
+    struct Brush(Vec<(&'static str, Value)>);
+    impl Brush {
+        fn at(&self, t: f64) -> Vec<(&'static str, Value)> {
+            let mut v = self.0.clone();
+            v.push(("brushPosition", Value::Vec2([8.0 + 48.0 * t.clamp(0.0, 1.0), 16.0])));
+            v
+        }
+    }
+    impl EffectHost for Brush {
+        fn layer(&self, _: u64, _: bool) -> Option<LayerPixels> {
+            None
+        }
+        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+            None
+        }
+        fn params_at(&self, t: f64) -> Option<Params> {
+            let s = crate::find("ec.generate.writeon").unwrap();
+            let mut p = Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+            for (k, v) in self.at(t) {
+                p.values.insert(k.to_string(), v);
+            }
+            Some(p)
+        }
+    }
+    let render = |extra: &[(&'static str, Value)], t: f64| {
+        let mut set = vec![("color", col(1.0, 0.0, 0.0)), ("brushSize", num(6.0)), ("brushHardness", num(100.0)), ("brushSpacing", num(0.05))];
+        set.extend(extra.iter().cloned());
+        let host = Brush(set);
+        let env = EffectEnv { host: Some(&host), ..Default::default() };
+        let at = host.at(t);
+        run_env("ec.generate.writeon", &at, Image::new(64, 32), t, env).img
+    };
+    let on = |img: &Image, x: i64| img.get(x, 16)[3] > 0.9;
+    let half = render(&[], 0.5);
+    assert!(on(&half, 8) && on(&half, 20) && on(&half, 32) && !on(&half, 44) && !on(&half, 56));
+    let end = render(&[], 1.0);
+    assert!([8, 20, 32, 44, 56].iter().all(|x| on(&end, *x)));
+    // Stroke Length 0.25 s: only the last quarter second's trail.
+    let trail = render(&[("strokeLength", num(0.25))], 1.0);
+    assert!(!on(&trail, 8) && !on(&trail, 32) && on(&trail, 48) && on(&trail, 56));
+    // Brush Spacing 0.5 s: three separate marks.
+    let spaced = render(&[("brushSpacing", num(0.5))], 1.0);
+    assert!(on(&spaced, 8) && on(&spaced, 32) && on(&spaced, 56) && !on(&spaced, 20) && !on(&spaced, 44));
+    // Paint Time Properties ▸ Opacity: each dab keeps the opacity it was laid with.
+    struct Fade;
+    impl EffectHost for Fade {
+        fn layer(&self, _: u64, _: bool) -> Option<LayerPixels> {
+            None
+        }
+        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+            None
+        }
+        fn params_at(&self, t: f64) -> Option<Params> {
+            let mut p = Brush(vec![("brushHardness", num(100.0)), ("brushSpacing", num(0.05)), ("paintTimeProperties", Value::Enum(1))]).params_at(t)?;
+            p.values.insert("brushOpacity".into(), num(if t < 0.5 { 100.0 } else { 20.0 }));
+            Some(p)
+        }
+    }
+    let p1 = Fade.params_at(1.0).unwrap();
+    let set: Vec<(&str, Value)> = p1.values.iter().map(|(k, v)| (k.as_str(), v.clone())).collect();
+    let faded = run_env("ec.generate.writeon", &set, Image::new(64, 32), 1.0, EffectEnv { host: Some(&Fade), ..Default::default() }).img;
+    assert!(faded.get(8, 16)[3] > 0.9 && (faded.get(56, 16)[3] - 0.2).abs() < 0.05, "{:?} {:?}", faded.get(8, 16), faded.get(56, 16));
+}
+
+#[test]
+fn paint_bucket_fills_enclosed_region_only() {
+    let mut img = Image::filled(32, 32, [1.0, 1.0, 1.0, 1.0]);
+    for i in 8..24 {
+        for &(x, y) in &[(i, 8), (i, 23), (8, i), (23, i)] {
+            img.set(x, y, [0.0, 0.0, 0.0, 1.0]);
+        }
+    }
+    let out = run("ec.generate.paintbucket", &[], img.clone());
+    let inside = out.img.get(16, 16);
+    assert!(inside[0] > 0.99 && inside[1] < 0.01, "{inside:?}");
+    assert_eq!(out.img.get(2, 2), [1.0, 1.0, 1.0, 1.0], "outside untouched");
+    assert_eq!(out.img.get(8, 16), [0.0, 0.0, 0.0, 1.0], "border untouched");
+    assert_eq!(out.img.data, run("ec.generate.paintbucket", &[], img).img.data);
+}
+
+#[test]
+fn eyedropper_fill_uses_sample() {
+    let mut img = Image::filled(16, 16, [0.0, 0.0, 1.0, 1.0]);
+    img.set(8, 8, [1.0, 0.0, 0.0, 1.0]);
+    let out = run("ec.generate.eyedropperfill", &[], img.clone());
+    assert!(out.img.data.iter().all(|p| *p == [1.0, 0.0, 0.0, 1.0]));
+    let blended = run("ec.generate.eyedropperfill", &[("blendWithOriginal", num(100.0))], img.clone());
+    assert_eq!(blended.img.data, img.data);
+}
+
+#[test]
+fn threads_weave_is_deterministic_and_gappy() {
+    let src = Image::filled(64, 64, [0.4, 0.6, 0.2, 1.0]);
+    let a = run("ec.generate.ccthreads", &[("width", num(16.0)), ("height", num(16.0)), ("coverage", num(50.0))], src.clone());
+    assert_eq!(a.img.data, run("ec.generate.ccthreads", &[("width", num(16.0)), ("height", num(16.0)), ("coverage", num(50.0))], src).img.data);
+    assert!(a.img.data.iter().any(|p| p[3] == 0.0), "gaps between threads");
+    assert!(a.img.data.iter().any(|p| p[3] > 0.99), "threads");
+}
+
+struct Tone;
+impl EffectHost for Tone {
+    fn layer(&self, _: u64, _: bool) -> Option<LayerPixels> {
+        None
+    }
+    fn audio(&self, _: u64, start: f64, frames: usize, rate: u32) -> Option<Vec<f32>> {
+        Some(
+            (0..frames)
+                .flat_map(|i| {
+                    let t = start + i as f64 / rate as f64;
+                    let v = (2.0 * PI * 440.0 * t).sin() as f32 * 0.8;
+                    [v, v]
+                })
+                .collect(),
+        )
+    }
+}
+
+#[test]
+fn audio_effects_without_audio_pass_through() {
+    let src = Image::filled(16, 16, [0.3, 0.3, 0.3, 1.0]);
+    for id in ["ec.generate.audiospectrum", "ec.generate.audiowaveform"] {
+        assert_eq!(run(id, &[], src.clone()).img.data, src.data, "{id}");
+    }
+}
+
+#[test]
+fn audio_effects_draw_with_host() {
+    let host = Tone;
+    let env = EffectEnv { host: Some(&host), comp_time: 1.0, ..Default::default() };
+    let img = Image::new(96, 64);
+    for id in ["ec.generate.audiospectrum", "ec.generate.audiowaveform"] {
+        let a = run_env(id, &[("audioLayer", Value::Layer(Some(1)))], img.clone(), 1.0, env);
+        let b = run_env(id, &[("audioLayer", Value::Layer(Some(1)))], img.clone(), 1.0, env);
+        assert_eq!(a.img.data, b.img.data, "{id}");
+        assert!(alpha_sum(&a.img, 0, 0, 96, 64) > 10.0, "{id} drew nothing");
+    }
+}
+
+#[test]
+fn fft_finds_tone() {
+    let n = 256;
+    let mut re: Vec<f64> = (0..n).map(|i| (2.0 * PI * 8.0 * i as f64 / n as f64).cos()).collect();
+    let mut im = vec![0.0; n];
+    fft(&mut re, &mut im);
+    let mags: Vec<f64> = (0..n / 2).map(|k| (re[k] * re[k] + im[k] * im[k]).sqrt()).collect();
+    let peak = mags.iter().enumerate().max_by(|a, b| a.1.total_cmp(b.1)).unwrap().0;
+    assert_eq!(peak, 8);
+}
+
+#[test]
+fn stroke_outline_caps_and_joins() {
+    let line = vec![vec![[10.0, 10.0], [30.0, 10.0]]];
+    let cov = |cap: u32| raster_convex(40, 20, &stroke_outline(&line, 3.0, cap, 0, 4.0));
+    // Round caps reach 3 px past the ends (on the axis), Butt stops there, Projecting is square.
+    let (round, butt, proj) = (cov(0), cov(1), cov(2));
+    assert!(round.get(8, 10) > 0.9 && butt.get(8, 10) < 0.1 && proj.get(8, 10) > 0.9);
+    assert!(proj.get(7, 7) > 0.9 && round.get(7, 7) < 0.5, "square corner");
+    // A right-angle turn: Miter fills the outer corner, Bevel cuts it.
+    let corner = vec![vec![[5.0, 30.0], [30.0, 30.0], [30.0, 5.0]]];
+    let j = |join: u32| raster_convex(40, 40, &stroke_outline(&corner, 3.0, 1, join, 4.0));
+    let (miter, bevel) = (j(1), j(2));
+    assert!(miter.get(32, 32) > 0.9 && bevel.get(32, 32) < 0.1, "{} {}", miter.get(32, 32), bevel.get(32, 32));
+    // A tight miter limit falls back to a bevel.
+    let limited = raster_convex(40, 40, &stroke_outline(&corner, 3.0, 1, 1, 1.0));
+    assert!(limited.get(32, 32) < 0.1);
+}
+
+#[test]
+fn scribble_caps_and_start_end_apply_to() {
+    let masks = square_mask();
+    let env = EffectEnv { masks: &masks, ..Default::default() };
+    let img = Image::new(64, 64);
+    let base = [("wiggleType", Value::Enum(0)), ("strokeWidth", num(3.0))];
+    let round = run_env("ec.generate.scribble", &base, img.clone(), 0.0, env);
+    let butt = run_env(
+        "ec.generate.scribble",
+        &[base.as_slice(), &[("edgeOptions/endCap", Value::Enum(1)), ("edgeOptions/join", Value::Enum(2))]].concat(),
+        img.clone(),
+        0.0,
+        env,
+    );
+    assert_ne!(round.img.data, butt.img.data);
+    // Each Stroke: every stroke is trimmed on its own, so the half-way image has ink all over.
+    let two = vec![
+        crate::MaskShape { name: String::new(), points: vec![[4.0, 4.0], [28.0, 4.0], [28.0, 60.0], [4.0, 60.0]], closed: true, inverted: false },
+        crate::MaskShape { name: String::new(), points: vec![[36.0, 4.0], [60.0, 4.0], [60.0, 60.0], [36.0, 60.0]], closed: true, inverted: false },
+    ];
+    let env2 = EffectEnv { masks: &two, ..Default::default() };
+    let seq = [("scribble", Value::Enum(1)), ("end", num(50.0))];
+    let all = run_env("ec.generate.scribble", &[base.as_slice(), &seq].concat(), img.clone(), 0.0, env2);
+    let each = run_env("ec.generate.scribble", &[base.as_slice(), &seq, &[("startEndApplyTo", Value::Enum(1))]].concat(), img, 0.0, env2);
+    assert_ne!(all.img.data, each.img.data);
+}
diff --git a/crates/effects/src/lib.rs b/crates/effects/src/lib.rs
index cc0aad515..204e651ec 100644
--- a/crates/effects/src/lib.rs
+++ b/crates/effects/src/lib.rs
@@ -78,7 +78,7 @@ pub use color_fx::{
 pub use color_fx::{COLORAMA_PRESETS, ColoramaPalette};
 pub use color2::{Curve, auto_correct_settings, color_link_mode, color_link_sample, equalize_tables, luma_clip_points, shadow_highlight_amounts};
 pub use color3::OffsetCurve;
-pub use distort::transform_shutter;
+pub use distort::{transform_grow, transform_matrix_px, transform_shutter};
 pub use distort2::{MAGNIFY_MODES, bezier_grid, parse_mesh};
 pub use distort3::{RESHAPE_POINTS, ReshapeSetup, SmearSetup, cc_smear_pad, reshape_setup, smear_setup, warp_inverse_map};
 pub use distort4::liquify_mesh;
@@ -86,7 +86,10 @@ use effectcraft_keyframe::Value;
 use effectcraft_project::build::Ids;
 use effectcraft_project::{GroupKind, ParamUi, PropGroup, Property};
 pub use effectcraft_raster::{AuxChannels, Image};
-pub use misc::{INVERT_ALPHA, INVERT_CHANNELS, glow_ab_t, glow_operation};
+pub use misc::{
+    GLOW_GAIN, GLOW_KNEE, INVERT_ALPHA, INVERT_CHANNELS, glow_ab_t, glow_operation, glow_sigma, radial_wipe_sigma, radial_wipe_wedge, venetian_cover,
+    venetian_origin,
+};
 pub use sim::particle_state;
 pub use sim3::{PgBlit, PgPlan, playground_plan, playground_state};
 pub use stylize2::strobe_on;
@@ -104,7 +107,7 @@ pub use transition::place_layer;
 // effectcraft-gpu fx_noise.
 pub use keying2::{InnerOuterPlan, inner_outer_plan};
 pub use noise::remove_grain_level;
-pub use noise3::{FractalGpu, fractal_gpu};
+pub use noise3::{FractalGpu, NOISE_CELL, fractal_gpu};
 pub use stylize3::{BumpLight, bump_layer_id};
 pub use textfx::{TextLayer, text_layer};
 pub use time_fx::{PixelMotion, TimewarpPlan, TwStep, pmb_plan, posterized_time, time_frames, timewarp_crop, timewarp_plan};
@@ -287,6 +290,27 @@ impl Buf {
         self.offset[0] += origin[0] * self.scale;
         self.offset[1] += origin[1] * self.scale;
     }
+    /// Grow by transparent pixels: `sides` = left, top, right, bottom. Content keeps its place.
+    pub fn pad_sides(&mut self, sides: [u32; 4]) {
+        let [l, t, r, b] = sides;
+        if l == 0 && t == 0 && r == 0 && b == 0 {
+            return;
+        }
+        let (Some(w), Some(h)) = (self.img.width.checked_add(l).and_then(|v| v.checked_add(r)), self.img.height.checked_add(t).and_then(|v| v.checked_add(b)))
+        else {
+            return;
+        };
+        let mut out = Image::new(w, h);
+        let (sw, ow) = (self.img.width as usize, w as usize);
+        for y in 0..self.img.height as usize {
+            let at = (y + t as usize) * ow + l as usize;
+            let (Some(src), Some(dst)) = (self.img.data.get(y * sw..(y + 1) * sw), out.data.get_mut(at..at + sw)) else { continue };
+            dst.copy_from_slice(src);
+        }
+        self.img = out;
+        self.offset[0] += l as f64;
+        self.offset[1] += t as f64;
+    }
     /// Grow by `pad` transparent pixels on every side.
     pub fn pad(&mut self, pad: u32) {
         if pad == 0 {
diff --git a/crates/effects/src/misc.rs b/crates/effects/src/misc.rs
index 7468c6b84..e1f41954c 100644
--- a/crates/effects/src/misc.rs
+++ b/crates/effects/src/misc.rs
@@ -142,6 +142,28 @@ pub fn glow_ab_t(l: f32, looping: u32, loops: f32, phase: f32, mid: f32) -> f32
     t.max(0.0).powf(0.5f32.ln() / m.ln())
 }
 
+/// Glow's blur: a Gaussian of σ = 0.384 × Glow Radius. Fitted to After Effects 2026 (cases
+/// 807 and 808, Glow Radius 10 and 30 on a grey solid): the edge profile of the glow's
+/// coverage is an erfc step of that σ within 1.7/255 (it was σ = radius / 2).
+pub fn glow_sigma(radius: f64) -> f64 {
+    (radius * 0.384).max(0.5)
+}
+
+/// Glow's bright pass for the original colours, per channel of the straight colour `v`:
+/// `8 × (v − threshold + 0.0611)`, nothing below. Fitted to After Effects 2026 renders of grey
+/// 0.65 / 0.8 / 0.9 / 1, orange and light-blue solids at Threshold 40 / 60 / 80 % and Radius 10
+/// / 30 (36 channel values, exact to the 8-bit capture): the glow is linear in each channel,
+/// its gain is the same at every threshold and radius, and channels below the threshold add
+/// nothing (an orange solid glows red only).
+pub fn glow_bright_channel(v: f32, thr: f32) -> f32 {
+    (GLOW_GAIN * (v - thr + GLOW_KNEE)).max(0.0)
+}
+
+/// [`glow_bright_channel`]'s gain and threshold offset. `kernels.wgsl` repeats both as literals;
+/// the GPU test `glow_constants_match_the_cpu` checks that they are these.
+pub const GLOW_GAIN: f32 = 8.0;
+pub const GLOW_KNEE: f32 = 0.0611;
+
 /// Glow Operation options (blend modes the glow is applied with).
 pub const GLOW_OPERATIONS: [&str; 17] = [
     "Normal",
@@ -205,23 +227,31 @@ fn glow(ctx: &EffectCtx, mut b: Buf) -> Buf {
         // Glow Based On: brightness from the colours, or from the alpha channel.
         let l = if alpha_based { a } else { luminance(px[0] / a, px[1] / a, px[2] / a) };
         let k = ((l - thr) / (1.0 - thr).max(1e-3)).clamp(0.0, 1.0);
+        // Based on the colour channels, the glow's coverage is the layer's whole alpha, below
+        // the threshold too: After Effects darkens what lies under a dim layer's edge (glow_alpha).
+        let ga = if alpha_based { k * a } else { a };
         if let Some(map) = &arbitrary {
             let t = glow_ab_t(l, looping, loops, phase, mid);
             let c = map.iter().map(|cv| cv.as_ref().map_or(t, |cv| cv.eval(t))).collect::<Vec<f32>>();
-            *px = [c[0] * k * a, c[1] * k * a, c[2] * k * a, k * a];
+            *px = [c[0] * k * a, c[1] * k * a, c[2] * k * a, ga];
         } else if use_colors {
             let t = glow_ab_t(l, looping, loops, phase, mid);
             let c = [ca[0] + (cb[0] - ca[0]) * t, ca[1] + (cb[1] - ca[1]) * t, ca[2] + (cb[2] - ca[2]) * t];
-            *px = [c[0] * k * a, c[1] * k * a, c[2] * k * a, k * a];
+            *px = [c[0] * k * a, c[1] * k * a, c[2] * k * a, ga];
+        } else if alpha_based {
+            *px = [px[0] * k, px[1] * k, px[2] * k, ga];
         } else {
-            *px = px.map(|v| v * k);
+            // Original colours: each channel of the straight colour against the threshold.
+            let c = [px[0] / a, px[1] / a, px[2] / a].map(|v| glow_bright_channel(v, thr) * a);
+            *px = [c[0], c[1], c[2], ga];
         }
     });
-    let s = (radius / 2.0).max(0.5);
+    let s = glow_sigma(radius);
     let blurred = gaussian_blur(&bright, s * kx, s * ky, false);
     let mode = ctx.params.e("operation");
     b.img.data.par_iter_mut().zip(blurred.data.par_iter()).for_each(|(o, g)| {
-        let g = g.map(|v| v * intensity);
+        // Intensity scales the glow's colour; with the colour channels its coverage stays.
+        let g = [g[0] * intensity, g[1] * intensity, g[2] * intensity, if alpha_based { g[3] * intensity } else { g[3] }];
         match mode {
             // Behind: the glow shows only where the original is transparent.
             1 => {
@@ -525,22 +555,67 @@ fn linear_wipe(ctx: &EffectCtx, mut b: Buf) -> Buf {
     b
 }
 
+/// Standard normal CDF Φ (Abramowitz & Stegun 7.1.26 erf, |error| < 1.5e-7).
+fn norm_cdf(z: f64) -> f64 {
+    let x = z.abs() / std::f64::consts::SQRT_2;
+    let t = 1.0 / (1.0 + 0.327_591_1 * x);
+    let poly = t * (0.254_829_592 + t * (-0.284_496_736 + t * (1.421_413_741 + t * (-1.453_152_027 + t * 1.061_405_429))));
+    let erf = 1.0 - poly * (-x * x).exp();
+    if z >= 0.0 { 0.5 * (1.0 + erf) } else { 0.5 * (1.0 - erf) }
+}
+
+/// Radial Wipe's wiped wedge relative to the Start Angle: (first ray, span), degrees clockwise
+/// from up. Clockwise (0) wipes from the start angle on, Counterclockwise (1) back from it,
+/// Both (2) half each way.
+pub fn radial_wipe_wedge(wipe: u32, done: f64) -> (f64, f64) {
+    let span = done.clamp(0.0, 1.0) * 360.0;
+    match wipe {
+        1 => (-span, span),
+        2 => (-span / 2.0, span),
+        _ => (0.0, span),
+    }
+}
+
+/// Radial Wipe's feather: a Gaussian of σ = 0.4 × Feather pixels across both edges of the wedge
+/// (After Effects 2026, Feather 20: the edge profile is the same width in pixels at every
+/// radius, σ = 8.0 px, mean error 0.0002 over the frame).
+pub fn radial_wipe_sigma(feather: f64) -> f64 {
+    feather.max(0.0) * 0.4
+}
+
+/// Visible fraction of a pixel at `(ux, uy)` from the centre (y down) for a wiped wedge from
+/// `ray0` (absolute degrees clockwise from up) over `span` degrees: the signed distance to the
+/// wedge's nearer edge, through the feather's Gaussian.
+pub fn radial_wipe_alpha(ux: f64, uy: f64, ray0: f64, span: f64, sigma: f64) -> f64 {
+    let a = (ux.atan2(-uy).to_degrees() - ray0).rem_euclid(360.0);
+    let wiped = a < span;
+    let ray_dist = |deg: f64| {
+        let (s, c) = deg.to_radians().sin_cos();
+        // Ray direction (sin, −cos) in y-down pixels.
+        let along = ux * s - uy * c;
+        if along > 0.0 { (ux * c + uy * s).abs() } else { ux.hypot(uy) }
+    };
+    let d = ray_dist(ray0).min(ray_dist(ray0 + span));
+    let sd = if wiped { -d } else { d };
+    if sigma < 1e-3 {
+        return if wiped { 0.0 } else { 1.0 };
+    }
+    norm_cdf(sd / sigma)
+}
+
 fn radial_wipe(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let done = ctx.params.f("completion") / 100.0;
+    let done = (ctx.params.f("completion") / 100.0).clamp(0.0, 1.0);
+    if done <= 0.0 {
+        return b;
+    }
     let start = ctx.params.f("startAngle");
     let c = b.to_px(ctx.params.v2("center"));
-    let dir = ctx.params.e("wipe");
-    let feather = (ctx.params.f("feather")).max(0.01);
+    let (w0, span) = radial_wipe_wedge(ctx.params.e("wipe"), done);
+    let sigma = radial_wipe_sigma(ctx.params.f("feather")) * b.scale;
+    let full = done >= 1.0;
     b.img.rows_mut().for_each(|(y, row)| {
         for (x, px) in row.iter_mut().enumerate() {
-            let a = ((x as f64 + 0.5 - c.0).atan2(-(y as f64 + 0.5 - c.1)).to_degrees() - start).rem_euclid(360.0);
-            // Both: the wipe opens in both directions from the start angle at once.
-            let (a, edge) = match dir {
-                1 => (360.0 - a, done * 360.0),
-                2 => (a.min(360.0 - a), done * 180.0),
-                _ => (a, done * 360.0),
-            };
-            let k = ((a - edge) / feather + 0.5).clamp(0.0, 1.0) as f32;
+            let k = if full { 0.0 } else { radial_wipe_alpha(x as f64 + 0.5 - c.0, y as f64 + 0.5 - c.1, start + w0, span, sigma) as f32 };
             for ch in px.iter_mut() {
                 *ch *= k;
             }
@@ -549,16 +624,49 @@ fn radial_wipe(ctx: &EffectCtx, mut b: Buf) -> Buf {
     b
 }
 
+/// Venetian Blinds: how much of a pixel at phase `d` (0..`width`) a band of `done × width`
+/// covers, its two edges softened by a Gaussian of σ = Feather / 2 (σ in the units of `width`).
+/// Fitted to After Effects 2026 (Completion 40, Direction 30, Width 50, Feather 5 on 960 × 540
+/// and 480 × 270 layers): band from phase 0 to done × width, both edges Gaussian, within 6/255.
+pub fn venetian_cover(d: f64, width: f64, done: f64, sigma: f64) -> f64 {
+    let band = done * width;
+    if sigma < 1e-3 {
+        return if d < band { 1.0 } else { 0.0 };
+    }
+    // Wider than a few blinds the stripes blur into an even veil.
+    if sigma > 8.0 * width {
+        return done.clamp(0.0, 1.0);
+    }
+    let n = ((4.0 * sigma / width).ceil() as i64 + 1).clamp(1, 40);
+    let mut t = 0.0;
+    for k in -n..=n {
+        let u = d + k as f64 * width;
+        t += norm_cdf(u / sigma) - norm_cdf((u - band) / sigma);
+    }
+    t.clamp(0.0, 1.0)
+}
+
+/// Venetian Blinds' phase origin in layer pixels: the layer centre plus 0.6 px (fitted to the
+/// AE renders above; the stripes are measured from the layer's centre, not its corner).
+pub fn venetian_origin(layer_size: [f64; 2]) -> [f64; 2] {
+    [layer_size[0] / 2.0 + 0.6, layer_size[1] / 2.0 + 0.6]
+}
+
 fn venetian(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let done = ctx.params.f("completion") / 100.0;
+    let done = (ctx.params.f("completion") / 100.0).clamp(0.0, 1.0);
+    if done <= 0.0 {
+        return b;
+    }
     let ang = ctx.params.f("direction").to_radians();
     let width = (ctx.params.f("width") * b.scale).max(1.0);
-    let feather = (ctx.params.f("feather") * b.scale).max(0.001);
+    let sigma = ctx.params.f("feather").max(0.0) * b.scale / 2.0;
     let (dx, dy) = (ang.cos(), ang.sin());
+    let (ox, oy) = b.to_px(venetian_origin(ctx.layer_size));
     b.img.rows_mut().for_each(|(y, row)| {
+        let ry = (y as f64 + 0.5 - oy) * dy;
         for (x, px) in row.iter_mut().enumerate() {
-            let d = ((x as f64 + 0.5) * dx + (y as f64 + 0.5) * dy).rem_euclid(width);
-            let k = ((d - done * width) / feather + 0.5).clamp(0.0, 1.0) as f32;
+            let d = ((x as f64 + 0.5 - ox) * dx + ry).rem_euclid(width);
+            let k = (1.0 - venetian_cover(d, width, done, sigma)) as f32;
             for c in px.iter_mut() {
                 *c *= k;
             }
@@ -807,6 +915,189 @@ mod tests {
         img
     }
 
+    /// After Effects 2026 (cases 524, 807, 808, 809): Glow on a 50 % grey solid, which is below
+    /// the 60 % threshold, still covers a blurred copy of the layer's alpha with black, so the
+    /// red layer underneath darkens outside the edge. The halo is the same at Intensity 1 and 3
+    /// and with Composite Original On Top or Behind; its width follows Glow Radius.
+    #[test]
+    fn glow_halo_matches_after_effects() {
+        let grey = effectcraft_raster::Image::filled(200, 120, [0.5, 0.5, 0.5, 1.0]);
+        // AE's red under the halo at 0.5, 1.5, 3.5, 5.5 and 7.5 px outside the left edge
+        // (radius 10) and at 0.5, 5.5, 10.5, 20.5 px (radius 30); halo alpha = 1 − red.
+        let r10 = [(0.5, 140.0), (1.5, 165.0), (3.5, 208.0), (5.5, 234.0), (7.5, 248.0)];
+        let r30 = [(0.5, 132.0), (5.5, 173.0), (10.5, 208.0), (20.5, 245.0)];
+        for (radius, intensity, operation, profile) in [(10.0, 1.0, 1, &r10[..]), (10.0, 3.0, 1, &r10[..]), (10.0, 1.0, 0, &r10[..]), (30.0, 1.0, 1, &r30[..])]
+        {
+            let set = [
+                ("based", Value::Enum(1)),
+                ("threshold", num(60.0)),
+                ("radius", num(radius)),
+                ("intensity", num(intensity)),
+                ("operation", Value::Enum(operation)),
+            ];
+            let o = run_fx("ec.stylize.glow", &set, grey.clone(), 0.0, EffectEnv::default());
+            for &(d, red) in profile {
+                // Layer x = −d (pixel centre), mid-height; over AE's red: R = 1 − α, colour 0.
+                let (bx, by) = o.to_px([-d, 60.0]);
+                let p = o.img.get(bx.floor() as i64, by.floor() as i64);
+                let ae = 1.0 - red / 255.0;
+                assert!((p[3] - ae).abs() < 3.0 / 255.0, "radius {radius} intensity {intensity} op {operation} at {d} px: alpha {} vs AE {ae}", p[3]);
+                assert!(p[0].abs() < 1e-6, "the halo is black: {p:?}");
+            }
+        }
+    }
+
+    /// After Effects 2026, Glow at Threshold 60 %, Radius 10, Intensity 0.25 on 200 × 200
+    /// solids over red: the glow 1.5 px outside the left edge, premultiplied (the green / blue
+    /// channels of the render, where the red background adds nothing), and its alpha 0.353.
+    #[test]
+    fn glow_brightness_matches_after_effects() {
+        // (solid colour, channel, AE glow value 0..255)
+        let cases = [
+            ([0.65, 0.65, 0.65], 1, 20.0),
+            ([0.8, 0.8, 0.8], 1, 47.0),
+            ([0.9, 0.9, 0.9], 1, 65.0),
+            ([1.0, 1.0, 1.0], 1, 83.0),
+            ([1.0, 0.5, 0.0], 1, 0.0),
+            ([0.2, 0.6, 1.0], 1, 11.0),
+            ([0.2, 0.6, 1.0], 2, 83.0),
+        ];
+        for (c, ch, ae) in cases {
+            let img = effectcraft_raster::Image::filled(200, 200, [c[0], c[1], c[2], 1.0]);
+            let set = [("threshold", num(60.0)), ("radius", num(10.0)), ("intensity", num(0.25))];
+            let o = run_fx("ec.stylize.glow", &set, img, 0.0, EffectEnv::default());
+            let (bx, by) = o.to_px([-1.5, 100.0]);
+            let p = o.img.get(bx.floor() as i64, by.floor() as i64);
+            assert!((p[ch] * 255.0 - ae).abs() <= 2.5, "{c:?} channel {ch}: {} vs AE {ae}", p[ch] * 255.0);
+            assert!((p[3] - 0.353).abs() < 3.0 / 255.0, "{c:?}: alpha {}", p[3]);
+        }
+        // Intensity scales the colour linearly: white at Intensity 1 is 3.7 × its alpha.
+        let white = effectcraft_raster::Image::filled(200, 200, [1.0, 1.0, 1.0, 1.0]);
+        let o = run_fx("ec.stylize.glow", &[("threshold", num(60.0)), ("radius", num(10.0))], white, 0.0, EffectEnv::default());
+        let (bx, by) = o.to_px([-1.5, 100.0]);
+        let p = o.img.get(bx.floor() as i64, by.floor() as i64);
+        assert!((p[1] / p[3] - 3.69).abs() < 0.05, "{p:?}");
+    }
+
+    /// After Effects 2026: Radial Blur keeps the layer's edges. Zoom 20 on a flat grey 960 × 540
+    /// solid (case 713) leaves it flat and opaque to the edge (EffectCraft faded the edges toward
+    /// transparency, letting the red layer below show through); on a full-frame horizontal ramp
+    /// (case 829, centre [960, 540]) row 540 reads 2/255 at x = 2 and 253/255 at x = 1917.
+    #[test]
+    fn radial_blur_keeps_the_layer_edges_as_after_effects() {
+        let zoom = |c: [f64; 2]| [("amount", num(20.0)), ("type", Value::Enum(1)), ("center", Value::Vec2(c))];
+        let grey = effectcraft_raster::Image::filled(960, 540, [0.5, 0.5, 0.5, 1.0]);
+        let o = run_fx("ec.blur.radial", &zoom([600.0, 300.0]), grey, 0.0, EffectEnv::default());
+        for (x, y) in [(0, 270), (1, 270), (959, 270), (480, 0), (480, 539), (0, 0), (959, 539)] {
+            let p = o.img.get(x, y);
+            assert!((p[3] - 1.0).abs() < 1e-4 && (p[0] - 0.5).abs() < 1e-4, "({x}, {y}): {p:?}");
+        }
+        let mut ramp = effectcraft_raster::Image::new(1920, 1080);
+        ramp.rows_mut().for_each(|(_, row)| {
+            for (x, px) in row.iter_mut().enumerate() {
+                let v = (x as f32 + 0.5) / 1920.0;
+                *px = [v, v, v, 1.0];
+            }
+        });
+        let o = run_fx("ec.blur.radial", &zoom([960.0, 540.0]), ramp, 0.0, EffectEnv::default());
+        for (x, ae) in [(2, 2.0), (1917, 253.0)] {
+            let p = o.img.get(x, 540);
+            assert!((p[0] * 255.0 - ae).abs() <= 2.0 && (p[3] - 1.0).abs() < 1e-4, "x {x}: {p:?} vs AE {ae}");
+        }
+    }
+
+    /// After Effects 2026, Venetian Blinds Completion 40, Direction 30, Width 50, Feather 5 on
+    /// an opaque 480 × 270 layer: alpha (0..255) along row y = 135. The transparent band starts
+    /// at the layer centre's phase, both edges are Gaussian (σ = Feather / 2).
+    #[test]
+    fn venetian_blinds_match_after_effects() {
+        let img = effectcraft_raster::Image::filled(480, 270, [0.5, 0.5, 0.5, 1.0]);
+        let vals = [("completion", Value::Scalar(40.0)), ("direction", Value::Scalar(30.0)), ("width", Value::Scalar(50.0)), ("feather", Value::Scalar(5.0))];
+        let o = run_fx("ec.transition.venetian", &vals, img, 0.0, EffectEnv::default());
+        let ae = [
+            (200, 5.0),
+            (203, 47.0),
+            (206, 145.0),
+            (209, 228.0),
+            (212, 253.0),
+            (224, 255.0),
+            (236, 238.0),
+            (239, 168.0),
+            (242, 66.0),
+            (245, 10.0),
+            (251, 0.0),
+            (257, 2.0),
+            (260, 31.0),
+        ];
+        for (x, a) in ae {
+            let got = o.img.get(x, 135)[3] * 255.0;
+            assert!((got - a).abs() <= 6.0, "x {x}: alpha {got} vs AE {a}");
+        }
+        // No completion leaves the layer; full completion clears it; no feather is a hard edge.
+        let full = [("completion", Value::Scalar(100.0)), ("feather", Value::Scalar(5.0))];
+        let img = effectcraft_raster::Image::filled(40, 20, [0.5, 0.5, 0.5, 1.0]);
+        assert!(run_fx("ec.transition.venetian", &full, img.clone(), 0.0, EffectEnv::default()).img.data.iter().all(|p| p[3] < 1e-4));
+        assert_eq!(run_fx("ec.transition.venetian", &[("completion", Value::Scalar(0.0))], img.clone(), 0.0, EffectEnv::default()).img, img);
+        let hard = run_fx(
+            "ec.transition.venetian",
+            &[("completion", Value::Scalar(50.0)), ("width", Value::Scalar(10.0)), ("feather", Value::Scalar(0.0))],
+            img,
+            0.0,
+            EffectEnv::default(),
+        );
+        assert!(hard.img.data.iter().all(|p| p[3] == 0.0 || p[3] == 1.0));
+        // A feather far wider than the blinds is an even veil.
+        assert_eq!(venetian_cover(3.0, 10.0, 0.5, 1e9), 0.5);
+    }
+
+    /// After Effects 2026, Radial Wipe Completion 40, Start Angle 30, Wipe Counterclockwise,
+    /// Feather 20, centre (800, 500): visible fraction at pixel offsets from the centre on both
+    /// edges (8-bit captures of dark steps, so ±0.05).
+    #[test]
+    fn radial_wipe_feather_matches_after_effects() {
+        let img = effectcraft_raster::Image::filled(400, 300, [1.0, 1.0, 1.0, 1.0]);
+        let vals = [
+            ("completion", Value::Scalar(40.0)),
+            ("startAngle", Value::Scalar(30.0)),
+            ("center", Value::Vec2([200.0, 150.0])),
+            ("wipe", Value::Enum(1)),
+            ("feather", Value::Scalar(20.0)),
+        ];
+        let o = run_fx("ec.transition.radialwipe", &vals, img.clone(), 0.0, EffectEnv::default());
+        let ae = [
+            ((-50, 34), 0.922),
+            ((-52, 30), 0.797),
+            ((-54, 26), 0.609),
+            ((-55, 24), 0.5),
+            ((-56, 22), 0.406),
+            ((-57, 19), 0.266),
+            ((-58, 15), 0.125),
+            ((-104, 60), 0.951),
+            ((-108, 53), 0.732),
+            ((-111, 45), 0.341),
+            ((-114, 37), 0.062),
+            ((22, -56), 0.156),
+            ((26, -54), 0.312),
+            ((30, -52), 0.531),
+            ((34, -50), 0.729),
+            ((37, -47), 0.875),
+            ((53, -108), 0.177),
+            ((67, -99), 0.875),
+        ];
+        for ((dx, dy), a) in ae {
+            let got = o.img.get(200 + dx, 150 + dy)[3];
+            assert!((got - a).abs() < 0.05, "offset ({dx}, {dy}): {got} vs AE {a}");
+        }
+        // 0 % leaves the layer, 100 % clears it, Feather 0 is a hard edge.
+        let at = |c: f64, f: f64| {
+            let v = [("completion", Value::Scalar(c)), ("feather", Value::Scalar(f))];
+            run_fx("ec.transition.radialwipe", &v, img.clone(), 0.0, EffectEnv::default()).img
+        };
+        assert_eq!(at(0.0, 20.0), img);
+        assert!(at(100.0, 20.0).data.iter().all(|p| p[3] == 0.0));
+        assert!(at(50.0, 0.0).data.iter().all(|p| p[3] == 0.0 || p[3] == 1.0));
+    }
+
     #[test]
     fn glow_operation_and_arbitrary_map() {
         // Pixels addressed in layer space (Glow pads its buffer).
diff --git a/crates/effects/src/noise3.rs b/crates/effects/src/noise3.rs
index bf1f05ed6..49f200553 100644
--- a/crates/effects/src/noise3.rs
+++ b/crates/effects/src/noise3.rs
@@ -60,6 +60,11 @@ pub const BLEND_NORMAL: u32 = 1;
 /// Index of "Soft Linear" in [`NOISE_TYPES`] (the default, and the GPU path's interpolation).
 pub const NOISE_SOFT_LINEAR: u32 = 2;
 
+/// Lattice cell of Fractal / Turbulent Noise in pixels per percent of Scale: After Effects 2026
+/// draws Block noise at Scale 100 in 66.67 px cells (and Soft Linear noise has the matching
+/// correlation length), not 100 px.
+pub const NOISE_CELL: f64 = 2.0 / 3.0;
+
 fn spec(id: &'static str, name: &'static str, params: Vec<ParamSpec>, render: crate::RenderFn) -> EffectSpec {
     EffectSpec { id, name, category: "Noise & Grain", params, render, gpu: false, float: true }
 }
@@ -236,7 +241,7 @@ impl Fractal {
             overflow: pr.e("overflow"),
             invert: pr.b("invert"),
             rot: rot.sin_cos(),
-            size: [(sw * b.scale).max(1.0) as f32, (sh * b.scale).max(1.0) as f32],
+            size: [(sw * NOISE_CELL * b.scale).max(1.0) as f32, (sh * NOISE_CELL * b.scale).max(1.0) as f32],
             origin: [ox as f32, oy as f32],
             center: [cx as f32, cy as f32],
             perspective: pr.b("transform/perspectiveOffset"),
@@ -535,14 +540,34 @@ mod tests {
 
     #[test]
     fn noise_types_differ_and_block_is_piecewise_constant() {
-        let a = run("ec.noise.fractal", &[("noiseType", Value::Enum(0)), ("complexity", num(1.0)), ("transform/scale", num(10.0))]);
-        // Block noise: neighbours inside one 10 px cell share a value.
+        let a = run("ec.noise.fractal", &[("noiseType", Value::Enum(0)), ("complexity", num(1.0)), ("transform/scale", num(15.0))]);
+        // Block noise: neighbours inside one 10 px cell (Scale 15) share a value.
         assert_eq!(a.get(4, 4), a.get(5, 5));
         let others: Vec<Image> = (1..4).map(|t| run("ec.noise.fractal", &[("noiseType", Value::Enum(t)), ("transform/scale", num(10.0))])).collect();
         assert_ne!(others[0], others[1]);
         assert_ne!(others[1], others[2]);
     }
 
+    /// After Effects 2026 (R9): Block noise at Scale 100, Complexity 1 changes value every
+    /// 66.67 px along a row.
+    #[test]
+    fn block_noise_cells_are_two_thirds_of_scale_as_in_after_effects() {
+        let img = run_fx(
+            "ec.noise.fractal",
+            &[("noiseType", Value::Enum(0)), ("complexity", num(1.0)), ("blendingMode", Value::Enum(BLEND_NONE))],
+            Image::filled(400, 8, [0.0, 0.0, 0.0, 1.0]),
+            0.0,
+            EffectEnv::default(),
+        )
+        .img;
+        let changes: Vec<i64> = (1..400).filter(|&x| img.get(x, 4) != img.get(x - 1, 4)).collect();
+        assert!(changes.len() >= 4, "{changes:?}");
+        for w in changes.windows(2) {
+            let d = (w[1] - w[0]) as f64;
+            assert!((d - 200.0 / 3.0).abs() <= 1.0, "cell width {d}: {changes:?}");
+        }
+    }
+
     #[test]
     fn scale_width_height_apply_without_uniform_scaling() {
         let base = &[("complexity", num(1.0)), ("transform/scale", num(8.0))];
diff --git a/crates/effects/src/object_matte.rs b/crates/effects/src/object_matte.rs
index d98ec73ad..e61357c9f 100644
--- a/crates/effects/src/object_matte.rs
+++ b/crates/effects/src/object_matte.rs
@@ -358,20 +358,24 @@ pub enum FrameMatte {
     Outside,
 }
 
-/// The matte of layer frame `f` on the layer grid of `img` (the effect's input on that frame at
-/// `scale`), computing what is missing. `frame(g)`: the input on frame g on the same grid.
-#[allow(clippy::too_many_arguments)]
+/// The layer grid and timing used to compute one object matte.
+pub struct MatteFrame<'a> {
+    pub layer_size: [f64; 2],
+    pub fps: f64,
+    pub frame: i64,
+    pub scale: f64,
+    pub img: &'a Image,
+}
+
+/// Compute the object's alpha for one layer frame, loading other frames on the same grid as needed.
 pub fn frame_matte(
     params: &Params,
-    layer_size: [f64; 2],
-    fps: f64,
-    f: i64,
-    scale: f64,
-    img: &Image,
+    input: &MatteFrame<'_>,
     model: Option<Arc<dyn MaskModel>>,
     frame: &mut dyn FnMut(i64) -> Option<Arc<Image>>,
     cancel: &dyn Fn() -> bool,
 ) -> FrameMatte {
+    let MatteFrame { layer_size, fps, frame: f, scale, img } = *input;
     let Some(chain) = chain(params, layer_size, fps, f, scale, model) else { return FrameMatte::NoPrompt };
     if !chain.data.in_span(f) {
         return FrameMatte::Outside;
@@ -408,7 +412,7 @@ fn render(ctx: &EffectCtx, buf: Buf) -> Buf {
     if let Some(a) = frozen_alpha(ctx.params, layer_size, fps, f, w, h, model.as_deref()) {
         return compose(&buf, Some(&a), w, h, b(ctx.params, "invert"), param(ctx.params, "view").map(Value::as_enum).unwrap_or(0) == 1);
     }
-    let alpha = match frame_matte(ctx.params, layer_size, fps, f, sc, &img, model, &mut frame, &|| false) {
+    let alpha = match frame_matte(ctx.params, &MatteFrame { layer_size, fps, frame: f, scale: sc, img: &img }, model, &mut frame, &|| false) {
         FrameMatte::Alpha(a) if a.len() == w * h => Some(a),
         FrameMatte::NoPrompt => return buf,
         _ => None,
@@ -608,7 +612,11 @@ mod tests {
         assert_ne!(seed(&p, [100.0, 80.0], 25.0, Some(stub.as_ref())), seed(&p, [100.0, 80.0], 25.0, None));
         let img = frame_at(0);
         let mut frame = |g: i64| Some(Arc::new(frame_at(g)));
-        let FrameMatte::Alpha(a) = frame_matte(&p, [100.0, 80.0], 25.0, 0, 1.0, &img, Some(stub.clone()), &mut frame, &|| false) else { panic!("no matte") };
+        let FrameMatte::Alpha(a) =
+            frame_matte(&p, &MatteFrame { layer_size: [100.0, 80.0], fps: 25.0, frame: 0, scale: 1.0, img: &img }, Some(stub.clone()), &mut frame, &|| false)
+        else {
+            panic!("no matte")
+        };
         assert!(a[40 * 100 + 40] > 0.5 && a[5 * 100 + 5] < 0.5);
         assert_eq!(stub.calls.load(std::sync::atomic::Ordering::Relaxed), 1);
         assert_eq!(*stub.bbox.lock().unwrap(), None);
@@ -634,7 +642,11 @@ mod tests {
         let stub = Arc::new(Stub::default());
         let img = frame_at(0);
         let mut frame = |g: i64| Some(Arc::new(frame_at(g)));
-        let FrameMatte::Alpha(a) = frame_matte(&p, [100.0, 80.0], 25.0, 0, 1.0, &img, Some(stub.clone()), &mut frame, &|| false) else { panic!("no matte") };
+        let FrameMatte::Alpha(a) =
+            frame_matte(&p, &MatteFrame { layer_size: [100.0, 80.0], fps: 25.0, frame: 0, scale: 1.0, img: &img }, Some(stub.clone()), &mut frame, &|| false)
+        else {
+            panic!("no matte")
+        };
         assert_eq!(*stub.bbox.lock().unwrap(), Some([74.0, 54.0, 100.0, 80.0]));
         assert!(a[70 * 100 + 90] > 0.5 && a[40 * 100 + 40] < 0.5);
         // At half resolution the box is scaled with the frame (another Input Key, so the
@@ -643,7 +655,8 @@ mod tests {
         p.values.insert(INPUT_KEY.into(), Value::Str("half".into()));
         let half = effectcraft_raster::resample(&img, 50, 40);
         let mut frame = |g: i64| Some(Arc::new(effectcraft_raster::resample(&frame_at(g), 50, 40)));
-        let _ = frame_matte(&p, [100.0, 80.0], 25.0, 0, 0.5, &half, Some(stub.clone()), &mut frame, &|| false);
+        let _ =
+            frame_matte(&p, &MatteFrame { layer_size: [100.0, 80.0], fps: 25.0, frame: 0, scale: 0.5, img: &half }, Some(stub.clone()), &mut frame, &|| false);
         assert_eq!(*stub.bbox.lock().unwrap(), Some([37.0, 27.0, 50.0, 40.0]));
     }
 
diff --git a/crates/effects/src/ocio.rs b/crates/effects/src/ocio.rs
index df579964f..2daa9857d 100644
--- a/crates/effects/src/ocio.rs
+++ b/crates/effects/src/ocio.rs
@@ -37,1802 +37,31 @@ use crate::util::unpremul;
 use crate::utility::{Lut, parse_cube};
 use crate::{Buf, EffectCtx, EffectSpec, num, p, popup, slider};
 
-type M3 = [[f64; 3]; 3];
+mod cdl;
+mod effects;
+mod lut;
+mod program;
+mod registry;
+mod space;
 
-pub(crate) const D65: [f64; 2] = [0.3127, 0.3290];
-const ACES_WHITE: [f64; 2] = [0.32168, 0.33767];
-const AP0: [[f64; 2]; 3] = [[0.7347, 0.2653], [0.0, 1.0], [0.0001, -0.0770]];
-const AP1: [[f64; 2]; 3] = [[0.713, 0.293], [0.165, 0.830], [0.128, 0.044]];
-pub(crate) const REC709: [[f64; 2]; 3] = [[0.640, 0.330], [0.300, 0.600], [0.150, 0.060]];
-pub(crate) const REC2020: [[f64; 2]; 3] = [[0.708, 0.292], [0.170, 0.797], [0.131, 0.046]];
-pub(crate) const P3: [[f64; 2]; 3] = [[0.680, 0.320], [0.265, 0.690], [0.150, 0.060]];
-const IDENTITY: M3 = [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]];
-
-/// Transfer functions (encoded ↔ linear).
-#[derive(Clone, Copy, Debug, PartialEq)]
-pub enum Tf {
-    Linear,
-    Srgb,
-    Gamma(f64),
-    AcesCct,
-    /// ACEScc (Academy S-2014-003), the pure-log grading encoding.
-    AcesCc,
-    /// SMPTE ST 2084 with 1.0 = 100 cd/m².
-    Pq,
-}
-
-/// ACEScc: the lowest code value (linear 0 and below) and the end of its toe (linear 2⁻¹⁵).
-const ACESCC_MIN: f64 = (-16.0 + 9.72) / 17.52;
-const ACESCC_TOE: f64 = (-15.0 + 9.72) / 17.52;
-
-impl Tf {
-    pub fn decode(self, v: f64) -> f64 {
-        match self {
-            Tf::Linear => v,
-            Tf::Srgb => {
-                let a = v.abs();
-                let l = if a <= 0.04045 { a / 12.92 } else { ((a + 0.055) / 1.055).powf(2.4) };
-                l.copysign(v)
-            }
-            Tf::Gamma(g) => v.abs().powf(g).copysign(v),
-            Tf::AcesCct => {
-                if v <= 0.155_251_141_552_511 {
-                    (v - 0.072_905_534_195_835_5) / 10.540_237_741_654_5
-                } else if v < (65504f64.log2() + 9.72) / 17.52 {
-                    2f64.powf(v * 17.52 - 9.72)
-                } else {
-                    65504.0
-                }
-            }
-            Tf::AcesCc => {
-                if v < ACESCC_TOE {
-                    (2f64.powf(v * 17.52 - 9.72) - 2f64.powi(-16)) * 2.0
-                } else if v < (65504f64.log2() + 9.72) / 17.52 {
-                    2f64.powf(v * 17.52 - 9.72)
-                } else {
-                    65504.0
-                }
-            }
-            Tf::Pq => {
-                let (m1, m2, c1, c2, c3) = pq_consts();
-                let e = v.max(0.0).powf(1.0 / m2);
-                let l = ((e - c1).max(0.0) / (c2 - c3 * e)).powf(1.0 / m1);
-                l * 100.0
-            }
-        }
-    }
-    pub fn encode(self, v: f64) -> f64 {
-        match self {
-            Tf::Linear => v,
-            Tf::Srgb => {
-                let a = v.abs();
-                let e = if a <= 0.003_130_8 { a * 12.92 } else { 1.055 * a.powf(1.0 / 2.4) - 0.055 };
-                e.copysign(v)
-            }
-            Tf::Gamma(g) => v.abs().powf(1.0 / g).copysign(v),
-            Tf::AcesCct => {
-                if v <= 0.007_812_5 {
-                    10.540_237_741_654_5 * v + 0.072_905_534_195_835_5
-                } else {
-                    (v.log2() + 9.72) / 17.52
-                }
-            }
-            Tf::AcesCc => {
-                if v <= 0.0 {
-                    ACESCC_MIN
-                } else if v < 2f64.powi(-15) {
-                    ((2f64.powi(-16) + v * 0.5).log2() + 9.72) / 17.52
-                } else {
-                    (v.log2() + 9.72) / 17.52
-                }
-            }
-            Tf::Pq => {
-                let (m1, m2, c1, c2, c3) = pq_consts();
-                let y = (v / 100.0).max(0.0).powf(m1);
-                ((c1 + c2 * y) / (1.0 + c3 * y)).powf(m2)
-            }
-        }
-    }
-}
-
-fn pq_consts() -> (f64, f64, f64, f64, f64) {
-    (2610.0 / 16384.0, 2523.0 / 4096.0 * 128.0, 3424.0 / 4096.0, 2413.0 / 4096.0 * 32.0, 2392.0 / 4096.0 * 32.0)
-}
-
-/// A colour space of the built-in config.
-#[derive(Clone, Copy, Debug)]
-pub struct Space {
-    pub name: &'static str,
-    /// Primaries and white (None = CIE XYZ itself).
-    pub prims: Option<([[f64; 2]; 3], [f64; 2])>,
-    pub tf: Tf,
-    /// Passes data through untouched.
-    pub raw: bool,
-}
-
-pub(crate) const fn sp(name: &'static str, prims: [[f64; 2]; 3], white: [f64; 2], tf: Tf) -> Space {
-    Space { name, prims: Some((prims, white)), tf, raw: false }
-}
-
-/// The built-in configuration's colour spaces, in popup order.
-pub(crate) const ACES2065_1: Space = sp("ACES2065-1", AP0, ACES_WHITE, Tf::Linear);
-pub(crate) const ACES_CG: Space = sp("ACEScg", AP1, ACES_WHITE, Tf::Linear);
-const ACES_CCT: Space = sp("ACEScct", AP1, ACES_WHITE, Tf::AcesCct);
-
-pub const SPACES: &[Space] = &[
-    ACES2065_1,
-    ACES_CG,
-    ACES_CCT,
-    sp("Linear Rec.709 (sRGB)", REC709, D65, Tf::Linear),
-    sp("sRGB", REC709, D65, Tf::Srgb),
-    sp("Gamma 2.4 Rec.709", REC709, D65, Tf::Gamma(2.4)),
-    sp("Linear Rec.2020", REC2020, D65, Tf::Linear),
-    sp("Gamma 2.4 Rec.2020", REC2020, D65, Tf::Gamma(2.4)),
-    sp("Linear P3-D65", P3, D65, Tf::Linear),
-    sp("Display P3", P3, D65, Tf::Srgb),
-    Space { name: "CIE-XYZ-D65", prims: None, tf: Tf::Linear, raw: false },
-    Space { name: "Raw", prims: None, tf: Tf::Linear, raw: true },
-];
-
-pub fn space_names() -> Vec<&'static str> {
-    SPACES.iter().map(|s| s.name).collect()
-}
+pub use cdl::Cdl;
+pub(crate) use effects::CUSTOM_CONFIG_FX;
+#[cfg(test)]
+pub use effects::parse_looks;
+pub use effects::{color_stabilizer_maps, warning};
+#[cfg(test)]
+use effects::{tonemap, tonemap_inv};
+pub use lut::{FileXform, load_file};
+#[cfg(test)]
+pub use lut::{parse_file, parse_spi1d, parse_spi3d, parse_spimtx};
+pub use program::{ColorOp, Straight, color_program};
+pub use registry::specs;
+#[cfg(test)]
+use space::M3;
+pub(crate) use space::{ACES_CG, ACES2065_1, D65, P3, REC709, REC2020, sp};
+#[cfg(test)]
+pub use space::{SPACES, Xform, bradford, space_by_name};
+pub use space::{Space, Tf, matrix};
 
 #[cfg(test)]
-pub fn space_by_name(n: &str) -> Option<&'static Space> {
-    SPACES.iter().find(|s| s.name.eq_ignore_ascii_case(n))
-}
-
-/// Bradford chromatic adaptation from white `src` to white `dst` (xy).
-pub fn bradford(src: [f64; 2], dst: [f64; 2]) -> M3 {
-    if src == dst {
-        return IDENTITY;
-    }
-    const MB: M3 = [[0.8951, 0.2664, -0.1614], [-0.7502, 1.7135, 0.0367], [0.0389, -0.0685, 1.0296]];
-    let xyz = |c: [f64; 2]| [c[0] / c[1], 1.0, (1.0 - c[0] - c[1]) / c[1]];
-    let s = mul_vec(&MB, xyz(src));
-    let d = mul_vec(&MB, xyz(dst));
-    let diag = [[d[0] / s[0], 0.0, 0.0], [0.0, d[1] / s[1], 0.0], [0.0, 0.0, d[2] / s[2]]];
-    mul(&invert(&MB), &mul(&diag, &MB))
-}
-
-impl Space {
-    /// Linear RGB → XYZ D65 (Bradford-adapted when `adapt`, else the space's own white).
-    pub fn to_ref(self, adapt: bool) -> M3 {
-        match self.prims {
-            None => IDENTITY,
-            Some((p, w)) => {
-                let m = rgb_to_xyz(p, w);
-                if adapt { mul(&bradford(w, D65), &m) } else { m }
-            }
-        }
-    }
-}
-
-/// Linear-RGB matrix from space `a` to space `b`.
-pub fn matrix(a: &Space, b: &Space) -> M3 {
-    mul(&invert(&b.to_ref(true)), &a.to_ref(true))
-}
-
-/// A compiled colour-space conversion.
-#[derive(Clone, Copy, Debug)]
-pub struct Xform {
-    dec: Tf,
-    m: [[f32; 3]; 3],
-    ident: bool,
-    enc: Tf,
-}
-
-impl Xform {
-    pub fn new(a: &Space, b: &Space) -> Xform {
-        if a.raw || b.raw {
-            return Xform { dec: Tf::Linear, m: IDENTITY.map(|r| r.map(|v| v as f32)), ident: true, enc: Tf::Linear };
-        }
-        let m = matrix(a, b);
-        let ident = (0..3).all(|i| (0..3).all(|j| (m[i][j] - IDENTITY[i][j]).abs() < 1e-12));
-        Xform { dec: a.tf, m: m.map(|r| r.map(|v| v as f32)), ident, enc: b.tf }
-    }
-    #[inline]
-    pub fn apply(&self, c: [f32; 3]) -> [f32; 3] {
-        let l = c.map(|v| self.dec.decode(v as f64) as f32);
-        let l = if self.ident { l } else { [0, 1, 2].map(|i| self.m[i][0] * l[0] + self.m[i][1] * l[1] + self.m[i][2] * l[2]) };
-        l.map(|v| self.enc.encode(v as f64) as f32)
-    }
-}
-
-// ---------------------------------------------------------------- ASC CDL
-
-/// An ASC Colour Decision List correction.
-#[derive(Clone, Copy, Debug, PartialEq)]
-pub struct Cdl {
-    pub slope: [f64; 3],
-    pub offset: [f64; 3],
-    pub power: [f64; 3],
-    pub sat: f64,
-}
-
-impl Default for Cdl {
-    fn default() -> Self {
-        Cdl { slope: [1.0; 3], offset: [0.0; 3], power: [1.0; 3], sat: 1.0 }
-    }
-}
-
-const LUMA: [f64; 3] = [0.2126, 0.7152, 0.0722];
-
-impl Cdl {
-    /// Forward CDL. `clamp` = the v1.2 style (results clamped to 0..1 after SOP and saturation).
-    pub fn apply(&self, c: [f64; 3], clamp: bool) -> [f64; 3] {
-        let mut o = [0.0; 3];
-        for i in 0..3 {
-            let v = c[i] * self.slope[i] + self.offset[i];
-            o[i] = if clamp {
-                v.clamp(0.0, 1.0).powf(self.power[i])
-            } else if v >= 0.0 {
-                v.powf(self.power[i])
-            } else {
-                v
-            };
-        }
-        let l = o[0] * LUMA[0] + o[1] * LUMA[1] + o[2] * LUMA[2];
-        let o = o.map(|v| l + self.sat * (v - l));
-        if clamp { o.map(|v| v.clamp(0.0, 1.0)) } else { o }
-    }
-    /// Exact inverse of [`Cdl::apply`] (inside the clamped range).
-    pub fn invert(&self, c: [f64; 3], clamp: bool) -> [f64; 3] {
-        let c = if clamp { c.map(|v| v.clamp(0.0, 1.0)) } else { c };
-        let l = c[0] * LUMA[0] + c[1] * LUMA[1] + c[2] * LUMA[2];
-        let s = if self.sat.abs() < 1e-9 { 1e-9 } else { self.sat };
-        let o = c.map(|v| l + (v - l) / s);
-        let mut r = [0.0; 3];
-        for i in 0..3 {
-            let v = if clamp { o[i].clamp(0.0, 1.0) } else { o[i] };
-            let pw = self.power[i].max(1e-9);
-            let u = if v >= 0.0 { v.powf(1.0 / pw) } else { v };
-            let sl = if self.slope[i].abs() < 1e-9 { 1e-9 } else { self.slope[i] };
-            r[i] = (u - self.offset[i]) / sl;
-        }
-        if clamp { r.map(|v| v.clamp(0.0, 1.0)) } else { r }
-    }
-}
-
-fn tag<'a>(xml: &'a str, name: &str) -> Option<&'a str> {
-    let open = xml.find(&format!("<{name}"))?;
-    let gt = open + xml[open..].find('>')?;
-    if xml[..gt].ends_with('/') {
-        return Some("");
-    }
-    let close = xml[gt..].find(&format!("</{name}>"))? + gt;
-    Some(&xml[gt + 1..close])
-}
-
-fn nums3(s: &str) -> Option<[f64; 3]> {
-    let v: Vec<f64> = s.split_whitespace().filter_map(|t| t.parse().ok()).collect();
-    (v.len() >= 3).then(|| [v[0], v[1], v[2]])
-}
-
-fn parse_cc(block: &str) -> Cdl {
-    let mut c = Cdl::default();
-    if let Some(s) = tag(block, "Slope").and_then(nums3) {
-        c.slope = s;
-    }
-    if let Some(s) = tag(block, "Offset").and_then(nums3) {
-        c.offset = s;
-    }
-    if let Some(s) = tag(block, "Power").and_then(nums3) {
-        c.power = s;
-    }
-    if let Some(s) = tag(block, "Saturation").and_then(|t| t.trim().parse().ok()) {
-        c.sat = s;
-    }
-    c
-}
-
-/// Parse ASC CDL XML (`.cc`, `.ccc`, `.cdl`): every `<ColorCorrection>` with its `id`.
-pub fn parse_cdl_xml(xml: &str) -> Vec<(String, Cdl)> {
-    let mut out = vec![];
-    let mut rest = xml;
-    while let Some(i) = rest.find("<ColorCorrection") {
-        let after = &rest[i..];
-        let head_end = after.find('>').unwrap_or(after.len());
-        let head = &after[..head_end];
-        let id = head
-            .find("id=")
-            .and_then(|k| {
-                let q = head[k + 3..].chars().next()?;
-                let s = &head[k + 4..];
-                s.find(q).map(|e| s[..e].to_string())
-            })
-            .unwrap_or_default();
-        let end = after.find("</ColorCorrection>").map(|e| e + "</ColorCorrection>".len()).unwrap_or(after.len());
-        out.push((id, parse_cc(&after[..end])));
-        rest = &after[end..];
-    }
-    out
-}
-
-// ---------------------------------------------------------------- LUT files
-
-/// A loaded transform file.
-#[derive(Clone, Debug)]
-pub enum FileXform {
-    /// A lattice/1D LUT with an optional per-channel piecewise-linear shaper (cineSpace pre-LUT).
-    Lut { lut: Lut, shaper: Option<[Vec<(f32, f32)>; 3]> },
-    /// CDL corrections by id (in file order).
-    Cdl(Vec<(String, Cdl)>),
-    /// A matrix with offset (Sony Imageworks `.spimtx`), as a MatrixTransform's.
-    Matrix { m: [f64; 16], offset: [f64; 4] },
-}
-
-/// Parse a Sony Imageworks `.spimtx` matrix: three rows of four numbers, three matrix columns
-/// and an offset in 16-bit code values (÷ 65535).
-pub fn parse_spimtx(text: &str) -> Option<FileXform> {
-    let v: Vec<f64> = text.split_whitespace().map(|t| t.parse().ok()).collect::<Option<_>>()?;
-    if v.len() != 12 || v.iter().any(|x| !x.is_finite()) {
-        return None;
-    }
-    let mut m = [0.0; 16];
-    let mut offset = [0.0; 4];
-    for (r, row) in v.as_chunks::<4>().0.iter().enumerate() {
-        m[r * 4..r * 4 + 3].copy_from_slice(&row[..3]);
-        offset[r] = row[3] / 65535.0;
-    }
-    m[15] = 1.0;
-    Some(FileXform::Matrix { m, offset })
-}
-
-/// Parse a Sony Imageworks `.spi1d` 1D LUT: `From <min> <max>`, `Length <n>`, `Components
-/// <1 | 3>`, then `{` the values `}`.
-pub fn parse_spi1d(text: &str) -> Option<Lut> {
-    let (mut from, mut len, mut comps) = ([0.0f32, 1.0], 0usize, 1usize);
-    let mut values: Vec<f32> = vec![];
-    let mut body = false;
-    for line in text.lines().map(str::trim).filter(|l| !l.is_empty()) {
-        if body {
-            if line.starts_with('}') {
-                break;
-            }
-            for t in line.split_whitespace() {
-                values.push(t.parse().ok()?);
-            }
-            continue;
-        }
-        let mut t = line.split_whitespace();
-        match t.next()? {
-            "{" => body = true,
-            "From" => from = [t.next()?.parse().ok()?, t.next()?.parse().ok()?],
-            "Length" => len = t.next()?.parse().ok()?,
-            "Components" => comps = t.next()?.parse().ok()?,
-            _ => {}
-        }
-    }
-    // A 1D table is interpolated by index, so cap it like the lattices (2²⁴ entries).
-    if !(2..=1 << 24).contains(&len)
-        || !matches!(comps, 1 | 3)
-        || values.len() != len.checked_mul(comps)?
-        || from[1] <= from[0]
-        || from.iter().any(|v| !v.is_finite())
-    {
-        return None;
-    }
-    let d1 = values.chunks_exact(comps).map(|c| if comps == 3 { [c[0], c[1], c[2]] } else { [c[0]; 3] }).collect();
-    Some(Lut { n1: len, d1, n3: 0, d3: vec![], dmin: [from[0]; 3], dmax: [from[1]; 3] })
-}
-
-/// Parse a Sony Imageworks `.spi3d` lattice: `SPILUT 1.0`, `3 3`, the sizes, then one
-/// `r g b  R G B` line per lattice point (indices, then the colour).
-pub fn parse_spi3d(text: &str) -> Option<Lut> {
-    let mut lines = text.lines().map(str::trim).filter(|l| !l.is_empty());
-    if !lines.next()?.starts_with("SPILUT") {
-        return None;
-    }
-    lines.next()?;
-    let size: Vec<usize> = lines.next()?.split_whitespace().map(|t| t.parse().ok()).collect::<Option<_>>()?;
-    let n = *size.first()?;
-    if size.len() != 3 || size.iter().any(|s| *s != n) || !(2..=129).contains(&n) {
-        return None;
-    }
-    let mut d3 = vec![[0.0f32; 3]; n * n * n];
-    let mut seen = 0usize;
-    for line in lines {
-        let v: Vec<&str> = line.split_whitespace().collect();
-        let [r, g, b, cr, cg, cb] = v.as_slice() else { return None };
-        let (r, g, b): (usize, usize, usize) = (r.parse().ok()?, g.parse().ok()?, b.parse().ok()?);
-        if r >= n || g >= n || b >= n {
-            return None;
-        }
-        // Our lattice is red fastest.
-        *d3.get_mut(r + g * n + b * n * n)? = [cr.parse().ok()?, cg.parse().ok()?, cb.parse().ok()?];
-        seen += 1;
-    }
-    (seen == n * n * n).then_some(Lut { n1: 0, d1: vec![], n3: n, d3, dmin: [0.0; 3], dmax: [1.0; 3] })
-}
-
-/// Parse an Autodesk `.3dl` lattice (integers, blue fastest; an optional input-mesh line).
-pub fn parse_3dl(text: &str) -> Option<Lut> {
-    let mut mesh: Option<Vec<f64>> = None;
-    let mut rows: Vec<[f64; 3]> = vec![];
-    let mut out_bits: Option<u32> = None;
-    for line in text.lines() {
-        let l = line.trim();
-        if l.is_empty() || l.starts_with('#') || l.starts_with('<') {
-            continue;
-        }
-        if l.starts_with(|c: char| c.is_ascii_alphabetic()) {
-            // "Mesh <in bits> <out bits>" (Lustre header); other keywords are ignored.
-            let t: Vec<&str> = l.split_whitespace().collect();
-            if t[0].eq_ignore_ascii_case("mesh") && t.len() >= 3 {
-                out_bits = t[2].parse().ok();
-            }
-            continue;
-        }
-        let v: Vec<f64> = l.split_whitespace().filter_map(|t| t.parse().ok()).collect();
-        if v.len() > 3 && mesh.is_none() && rows.is_empty() {
-            mesh = Some(v);
-        } else if v.len() == 3 {
-            rows.push([v[0], v[1], v[2]]);
-        } else {
-            return None;
-        }
-    }
-    let is_cube = |k: usize| {
-        let n = (k as f64).cbrt().round() as usize;
-        n * n * n == k
-    };
-    // A 3-entry input mesh (3³ lattice) looks like a data row: tell them apart by the count.
-    if mesh.is_none() && !is_cube(rows.len()) && rows.len() == 28 {
-        mesh = Some(rows.remove(0).to_vec());
-    }
-    let n = match &mesh {
-        Some(m) => m.len(),
-        None => (rows.len() as f64).cbrt().round() as usize,
-    };
-    if n < 2 || rows.len() != n * n * n {
-        return None;
-    }
-    let maxv = rows.iter().flat_map(|r| r.iter()).fold(0.0f64, |m, &v| m.max(v));
-    let out_max = match out_bits {
-        Some(b) if b > 0 && b < 32 => (1u64 << b) as f64 - 1.0,
-        _ => [255.0, 1023.0, 4095.0, 65535.0].into_iter().find(|&m| maxv <= m).unwrap_or(maxv.max(1.0)),
-    };
-    // .3dl rows: red slowest, blue fastest. Our lattice is red fastest.
-    let mut d3 = vec![[0.0f32; 3]; n * n * n];
-    for (k, r) in rows.iter().enumerate() {
-        let (ri, gi, bi) = (k / (n * n), (k / n) % n, k % n);
-        d3[ri + gi * n + bi * n * n] = r.map(|v| (v / out_max) as f32);
-    }
-    Some(Lut { n1: 0, d1: vec![], n3: n, d3, dmin: [0.0; 3], dmax: [1.0; 3] })
-}
-
-/// Parse a cineSpace `.csp` LUT (1D or 3D, with its three pre-LUT shapers).
-pub fn parse_csp(text: &str) -> Option<(Lut, [Vec<(f32, f32)>; 3])> {
-    let mut lines = text.lines().map(str::trim).filter(|l| !l.is_empty());
-    if !lines.next()?.starts_with("CSPLUTV100") {
-        return None;
-    }
-    let kind = lines.next()?;
-    let mut lines = lines.peekable();
-    if lines.peek().is_some_and(|l| l.starts_with("BEGIN METADATA")) {
-        for l in lines.by_ref() {
-            if l.starts_with("END METADATA") {
-                break;
-            }
-        }
-    }
-    let nums = |l: &str| -> Option<Vec<f32>> { l.split_whitespace().map(|t| t.parse().ok()).collect() };
-    let mut shaper: [Vec<(f32, f32)>; 3] = Default::default();
-    for ch in shaper.iter_mut() {
-        let n: usize = lines.next()?.parse().ok()?;
-        let ins = nums(lines.next()?)?;
-        let outs = nums(lines.next()?)?;
-        if ins.len() != n || outs.len() != n || n < 2 {
-            return None;
-        }
-        *ch = ins.into_iter().zip(outs).collect();
-    }
-    if kind.starts_with("3D") {
-        let sz = nums(lines.next()?)?;
-        if sz.len() != 3 || sz[0] != sz[1] || sz[1] != sz[2] {
-            return None;
-        }
-        let n = sz[0] as usize;
-        let mut d3 = Vec::with_capacity(n * n * n);
-        for _ in 0..n * n * n {
-            let v = nums(lines.next()?)?;
-            if v.len() != 3 {
-                return None;
-            }
-            d3.push([v[0], v[1], v[2]]);
-        }
-        (n >= 2).then_some((Lut { n1: 0, d1: vec![], n3: n, d3, dmin: [0.0; 3], dmax: [1.0; 3] }, shaper))
-    } else {
-        let n: usize = lines.next()?.parse().ok()?;
-        let mut d1 = Vec::with_capacity(n);
-        for _ in 0..n {
-            let v = nums(lines.next()?)?;
-            if v.len() != 3 {
-                return None;
-            }
-            d1.push([v[0], v[1], v[2]]);
-        }
-        (n >= 2).then_some((Lut { n1: n, d1, n3: 0, d3: vec![], dmin: [0.0; 3], dmax: [1.0; 3] }, shaper))
-    }
-}
-
-fn shape(curve: &[(f32, f32)], x: f32) -> f32 {
-    if curve.len() < 2 {
-        return x;
-    }
-    let i = curve.partition_point(|p| p.0 < x).clamp(1, curve.len() - 1);
-    let (a, b) = (curve[i - 1], curve[i]);
-    let t = ((x - a.0) / (b.0 - a.0).max(1e-12)).clamp(0.0, 1.0);
-    a.1 + (b.1 - a.1) * t
-}
-
-fn shape_inv(curve: &[(f32, f32)], y: f32) -> f32 {
-    let flipped: Vec<(f32, f32)> = curve.iter().map(|&(a, b)| (b, a)).collect();
-    shape(&flipped, y)
-}
-
-/// Parse transform text by its format (detected from `ext` or the content).
-pub fn parse_file(text: &str, ext: &str) -> Option<FileXform> {
-    let ext = ext.to_ascii_lowercase();
-    if ext == "cc" || ext == "ccc" || ext == "cdl" || text.contains("<ColorCorrection") {
-        let v = parse_cdl_xml(text);
-        return (!v.is_empty()).then_some(FileXform::Cdl(v));
-    }
-    if ext == "csp" || text.trim_start().starts_with("CSPLUTV100") {
-        return parse_csp(text).map(|(lut, s)| FileXform::Lut { lut, shaper: Some(s) });
-    }
-    if ext == "spimtx" {
-        return parse_spimtx(text);
-    }
-    if ext == "spi1d" || text.trim_start().starts_with("Version") {
-        return parse_spi1d(text).map(|lut| FileXform::Lut { lut, shaper: None });
-    }
-    if ext == "spi3d" || text.trim_start().starts_with("SPILUT") {
-        return parse_spi3d(text).map(|lut| FileXform::Lut { lut, shaper: None });
-    }
-    if ext == "cube" || text.contains("LUT_3D_SIZE") || text.contains("LUT_1D_SIZE") {
-        return parse_cube(text).map(|lut| FileXform::Lut { lut, shaper: None });
-    }
-    parse_3dl(text).map(|lut| FileXform::Lut { lut, shaper: None })
-}
-
-type FileCache = Mutex<HashMap<String, Option<Arc<FileXform>>>>;
-
-/// Load (and cache) a transform from a file path or inline content.
-pub fn load_file(src: &str) -> Option<Arc<FileXform>> {
-    let src_t = src.trim();
-    if src_t.is_empty() {
-        return None;
-    }
-    static CACHE: OnceLock<FileCache> = OnceLock::new();
-    let cache = CACHE.get_or_init(|| Mutex::new(HashMap::new()));
-    if let Ok(m) = cache.lock()
-        && let Some(v) = m.get(src)
-    {
-        return v.clone();
-    }
-    let inline = src.contains('\n');
-    let parsed = if inline {
-        parse_file(src, "")
-    } else {
-        let ext = std::path::Path::new(src_t).extension().and_then(std::ffi::OsStr::to_str).unwrap_or("");
-        std::fs::read_to_string(src_t).ok().and_then(|t| parse_file(&t, ext))
-    }
-    .map(Arc::new);
-    if let Ok(mut m) = cache.lock() {
-        m.insert(src.to_string(), parsed.clone());
-    }
-    parsed
-}
-
-impl FileXform {
-    pub fn apply(&self, c: [f32; 3], interp: u32, inverse: bool, ccc_id: &str) -> [f32; 3] {
-        match self {
-            FileXform::Cdl(list) => {
-                let cdl = list.iter().find(|(id, _)| !ccc_id.is_empty() && id == ccc_id).or(list.first()).map(|(_, c)| *c).unwrap_or_default();
-                let c64 = c.map(|v| v as f64);
-                let o = if inverse { cdl.invert(c64, true) } else { cdl.apply(c64, true) };
-                o.map(|v| v as f32)
-            }
-            FileXform::Matrix { m, offset } => crate::ocio_config::matrix_apply(m, offset, c.map(|v| v as f64), inverse).map(|v| v as f32),
-            FileXform::Lut { lut, shaper } => {
-                let fwd = |c: [f32; 3]| {
-                    let c = match shaper {
-                        Some(s) => [shape(&s[0], c[0]), shape(&s[1], c[1]), shape(&s[2], c[2])],
-                        None => c,
-                    };
-                    lut.apply_interp(c, interp)
-                };
-                if !inverse {
-                    return fwd(c);
-                }
-                if lut.n3 == 0 {
-                    // 1D: invert each channel exactly through the (monotone) tables.
-                    let mut x = c;
-                    if lut.n1 > 1 {
-                        x = [0, 1, 2].map(|i| {
-                            let curve: Vec<(f32, f32)> =
-                                (0..lut.n1).map(|k| (lut.d1[k][i], lut.dmin[i] + (lut.dmax[i] - lut.dmin[i]) * k as f32 / (lut.n1 - 1) as f32)).collect();
-                            shape(&curve, c[i])
-                        });
-                    }
-                    if let Some(s) = shaper {
-                        x = [shape_inv(&s[0], x[0]), shape_inv(&s[1], x[1]), shape_inv(&s[2], x[2])];
-                    }
-                    return x;
-                }
-                // 3D: damped fixed-point (Newton with an identity Jacobian) from the target.
-                let mut x = c;
-                for _ in 0..40 {
-                    let y = fwd(x);
-                    let e = [c[0] - y[0], c[1] - y[1], c[2] - y[2]];
-                    if e.iter().all(|v| v.abs() < 1e-6) {
-                        break;
-                    }
-                    x = [x[0] + e[0], x[1] + e[1], x[2] + e[2]];
-                }
-                x
-            }
-        }
-    }
-}
-
-// ---------------------------------------------------------------- displays, views and looks
-
-/// Displays of the built-in config: (name, display primaries/white, encoding).
-pub const DISPLAYS: &[(&str, [[f64; 2]; 3], Tf)] =
-    &[("sRGB", REC709, Tf::Srgb), ("Rec.1886 Rec.709", REC709, Tf::Gamma(2.4)), ("Display P3", P3, Tf::Srgb), ("Rec.2100-PQ", REC2020, Tf::Pq)];
-
-pub const VIEWS: &[&str] = &["Standard", "Tone Mapped", "Raw"];
-
-/// Configuration popup: the built-in config, or a custom `.ocio` file (Config File: a path or
-/// the config's text; spaces chosen by name, see [`crate::ocio_config`]).
-pub const CONFIGS: &[&str] = &["Built-in (EffectCraft minimal)", "Custom (.ocio file)"];
-
-/// Built-in looks: CDLs applied in ACEScct.
-pub fn looks() -> Vec<(&'static str, Cdl)> {
-    let grey = 0.413_588_402_492_442_1; // ACEScct of 0.18
-    let c = |slope: [f64; 3], offset: [f64; 3], sat: f64| Cdl { slope, offset, power: [1.0; 3], sat };
-    vec![
-        ("Warm", c([1.04, 1.0, 0.94], [0.0; 3], 1.0)),
-        ("Cool", c([0.95, 1.0, 1.06], [0.0; 3], 1.0)),
-        ("High Contrast", c([1.25; 3], [grey * (1.0 - 1.25); 3], 1.0)),
-        ("Low Contrast", c([0.8; 3], [grey * (1.0 - 0.8); 3], 1.0)),
-        ("Desaturated", c([1.0; 3], [0.0; 3], 0.6)),
-        ("Vivid", c([1.0; 3], [0.0; 3], 1.3)),
-    ]
-}
-
-/// Extended Reinhard roll-off (white point 16): maps 0..∞ into 0..1, ≈ identity near 0.
-fn tonemap(v: f64) -> f64 {
-    let w2 = 256.0;
-    if v <= 0.0 { v } else { v * (1.0 + v / w2) / (1.0 + v) }
-}
-
-fn tonemap_inv(y: f64) -> f64 {
-    if y <= 0.0 {
-        return y;
-    }
-    // Solve v² / w² + v (1 − y) − y = 0.
-    let (a, b, c) = (1.0 / 256.0, 1.0 - y, -y);
-    (-b + (b * b - 4.0 * a * c).sqrt()) / (2.0 * a)
-}
-
-/// Display transform of an input-space colour (`inverse`: display code values → input space).
-pub fn display_xform(input: &Space, display: usize, view: usize, inverse: bool) -> impl Fn([f32; 3]) -> [f32; 3] + Sync {
-    let (_, prims, tf) = DISPLAYS[display.min(DISPLAYS.len() - 1)];
-    let disp = Space { name: "display", prims: Some((prims, D65)), tf: Tf::Linear, raw: false };
-    let raw = view == 2 || input.raw;
-    let m_in = Xform::new(&Space { tf: Tf::Linear, ..*input }, &disp);
-    let m_out = Xform::new(&disp, &Space { tf: Tf::Linear, ..*input });
-    let in_tf = input.tf;
-    move |c: [f32; 3]| {
-        if raw {
-            return c;
-        }
-        if !inverse {
-            let lin = c.map(|v| in_tf.decode(v as f64) as f32);
-            let d = m_in.apply(lin);
-            d.map(|v| {
-                let v = v as f64;
-                let v = if view == 1 { tonemap(v) } else { v };
-                tf.encode(v) as f32
-            })
-        } else {
-            let d = c.map(|v| {
-                let l = tf.decode(v as f64);
-                (if view == 1 { tonemap_inv(l) } else { l }) as f32
-            });
-            m_out.apply(d).map(|v| in_tf.encode(v as f64) as f32)
-        }
-    }
-}
-
-// ---------------------------------------------------------------- effects
-
-fn spec(id: &'static str, name: &'static str, cat: &'static str, params: Vec<crate::ParamSpec>, render: crate::RenderFn) -> EffectSpec {
-    EffectSpec { id, name, category: cat, params, render, gpu: false, float: true }
-}
-
-fn space_param(id: &'static str, name: &'static str, default: u32) -> crate::ParamSpec {
-    p(id, name, Value::Enum(default), popup(&space_names()))
-}
-
-fn direction() -> crate::ParamSpec {
-    p("direction", "Direction", Value::Enum(0), popup(&["Forward", "Inverse"]))
-}
-
-fn map_px(b: &mut Buf, f: impl Fn([f32; 3]) -> [f32; 3] + Sync) {
-    b.img.data.par_iter_mut().for_each(|px| {
-        let (c, a) = unpremul(*px);
-        if a <= 0.0 {
-            return;
-        }
-        let o = f(c);
-        *px = [o[0] * a, o[1] * a, o[2] * a, a];
-    });
-}
-
-fn space_at(i: u32) -> &'static Space {
-    &SPACES[(i as usize).min(SPACES.len() - 1)]
-}
-
-/// The effects that take Configuration ▸ Custom (a `.ocio` file).
-pub(crate) const CUSTOM_CONFIG_FX: [&str; 2] = ["ec.color.ociocolorspace", "ec.color.ociodisplay"];
-
-/// Effect `id`'s transform under Configuration ▸ Custom: the config's conversion from the source
-/// space to the destination space (Color Space Transform) or through a display's view (Display
-/// Transform), see [`crate::ocio_config`]. `Ok(None)` with the built-in configuration; an error
-/// (the pixels pass through) when the config can't be read or has no such colour space.
-fn custom_xf(id: &str, pr: &crate::Params) -> Result<Option<crate::ocio_config::Xf>, String> {
-    use crate::ocio_config::Xf;
-    if !CUSTOM_CONFIG_FX.contains(&id) || pr.e("config") != 1 {
-        return Ok(None);
-    }
-    let cfg = crate::ocio_config::load_config(pr.s("configFile")).map_err(|e| format!("Can't read the OCIO config: {e}"))?;
-    // A space by its typed name, else by the built-in popup's name.
-    let space = |name: &str, popup: u32| {
-        let name = if name.trim().is_empty() { space_at(popup).name } else { name.trim() };
-        cfg.space(name).ok_or_else(|| format!("The OCIO config has no color space `{name}`"))
-    };
-    let a = space(pr.s("sourceName"), pr.e("source"))?;
-    let inverse = pr.e("direction") == 1;
-    if id == "ec.color.ociodisplay" {
-        let (dn, vn) = display_view_names(pr);
-        let xf = cfg.display_path(a, dn, vn);
-        return Ok(Some(if inverse { Xf::Inverse(Box::new(xf)) } else { xf }));
-    }
-    let z = space(pr.s("destinationName"), pr.e("destination"))?;
-    // Inverse: the conversion the other way (OCIO's inverse ColorSpaceTransform).
-    Ok(Some(if inverse { cfg.path(z, a) } else { cfg.path(a, z) }))
-}
-
-/// The display and view a Display Transform names: the typed names, else the popups'.
-fn display_view_names(pr: &crate::Params) -> (&str, &str) {
-    let display = DISPLAYS.get(pr.e("display") as usize).map_or("", |d| d.0);
-    let view = VIEWS.get(pr.e("view") as usize).copied().unwrap_or("");
-    let typed = |k: &str, popup| if pr.s(k).trim().is_empty() { popup } else { pr.s(k).trim() };
-    (typed("displayName", display), typed("viewName", view))
-}
-
-/// Effect Controls' warning for effect `id`: a custom OCIO configuration that can't be read, has
-/// no such colour space, display or view, or uses transforms EffectCraft can't apply (colours
-/// pass through those steps, #410). `None` when the effect renders as asked.
-pub fn warning(id: &str, pr: &crate::Params) -> Option<String> {
-    let xf = match custom_xf(id, pr) {
-        Ok(x) => x?,
-        Err(e) => return Some(format!("{e}: the colors pass through.")),
-    };
-    let mut notes = vec![];
-    if id == "ec.color.ociodisplay"
-        && let Ok(cfg) = crate::ocio_config::load_config(pr.s("configFile"))
-    {
-        let (dn, vn) = display_view_names(pr);
-        if let Some((d, v)) = cfg.view(dn, vn)
-            && (!d.eq_ignore_ascii_case(dn) || !v.name.eq_ignore_ascii_case(vn))
-        {
-            notes.push(format!("The OCIO config has no display `{dn}` with a view `{vn}`: showing {d} / {}.", v.name));
-        }
-    }
-    let missing = xf.unsupported_list();
-    if !missing.is_empty() {
-        notes.push(format!("Not supported, the colors pass through: {}.", missing.join(", ")));
-    }
-    (!notes.is_empty()).then(|| notes.join(" "))
-}
-
-/// Configuration ▸ Custom: render through the config's transform. `false` with the built-in
-/// configuration (the caller renders it).
-fn custom_render(id: &str, ctx: &EffectCtx, b: &mut Buf) -> bool {
-    match custom_xf(id, ctx.params) {
-        Ok(None) => false,
-        Ok(Some(xf)) => {
-            map_px(b, |c| xf.apply(c.map(|v| v as f64), false).map(|v| v as f32));
-            true
-        }
-        // A config that can't be read, or an unknown space: the pixels pass through.
-        Err(_) => true,
-    }
-}
-
-fn ocio_cst(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    if custom_render("ec.color.ociocolorspace", ctx, &mut b) {
-        return b;
-    }
-    let (a, z) = (space_at(ctx.params.e("source")), space_at(ctx.params.e("destination")));
-    let (a, z) = if ctx.params.e("direction") == 1 { (z, a) } else { (a, z) };
-    if a.name == z.name {
-        return b;
-    }
-    let x = Xform::new(a, z);
-    map_px(&mut b, |c| x.apply(c));
-    b
-}
-
-fn cdl_from_params(pr: &crate::Params) -> Cdl {
-    Cdl {
-        slope: [pr.f("slopeRed"), pr.f("slopeGreen"), pr.f("slopeBlue")],
-        offset: [pr.f("offsetRed"), pr.f("offsetGreen"), pr.f("offsetBlue")],
-        power: [pr.f("powerRed").max(0.0), pr.f("powerGreen").max(0.0), pr.f("powerBlue").max(0.0)],
-        sat: pr.f("saturation").max(0.0),
-    }
-}
-
-fn ocio_cdl(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let cdl = cdl_from_params(ctx.params);
-    if cdl == Cdl::default() {
-        return b;
-    }
-    let clamp = ctx.params.e("style") == 0;
-    let inv = ctx.params.e("direction") == 1;
-    map_px(&mut b, |c| {
-        let c = c.map(|v| v as f64);
-        let o = if inv { cdl.invert(c, clamp) } else { cdl.apply(c, clamp) };
-        o.map(|v| v as f32)
-    });
-    b
-}
-
-fn ocio_display(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    if custom_render("ec.color.ociodisplay", ctx, &mut b) {
-        return b;
-    }
-    let input = space_at(ctx.params.e("source"));
-    let f = display_xform(input, ctx.params.e("display") as usize, ctx.params.e("view") as usize, ctx.params.e("direction") == 1);
-    map_px(&mut b, f);
-    b
-}
-
-fn ocio_file(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let Some(x) = load_file(ctx.params.s("file")) else { return b };
-    let interp = match ctx.params.e("interpolation") {
-        0 => 0,
-        1 => 1,
-        _ => 2,
-    };
-    let inv = ctx.params.e("direction") == 1;
-    let id = ctx.params.s("cccId").to_string();
-    map_px(&mut b, |c| x.apply(c, interp, inv, &id));
-    b
-}
-
-/// Parse a looks string: comma/space separated names, `-Name` = inverse.
-pub fn parse_looks(s: &str) -> Vec<(Cdl, bool)> {
-    let all = looks();
-    s.split([',', ':'])
-        .map(str::trim)
-        .filter(|t| !t.is_empty())
-        .filter_map(|t| {
-            let (inv, n) = match t.strip_prefix('-') {
-                Some(r) => (true, r.trim()),
-                None => (false, t.trim_start_matches('+').trim()),
-            };
-            all.iter().find(|(name, _)| name.eq_ignore_ascii_case(n)).map(|(_, c)| (*c, inv))
-        })
-        .collect()
-}
-
-fn ocio_look(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let mut list = parse_looks(ctx.params.s("looks"));
-    let pick = ctx.params.e("look");
-    if pick > 0
-        && let Some((_, c)) = looks().get(pick as usize - 1)
-    {
-        list.insert(0, (*c, false));
-    }
-    if list.is_empty() {
-        return b;
-    }
-    let (src, dst) = (space_at(ctx.params.e("source")), space_at(ctx.params.e("destination")));
-    let inv = ctx.params.e("direction") == 1;
-    let cct = &ACES_CCT;
-    let (a, z) = if inv { (dst, src) } else { (src, dst) };
-    let to_p = Xform::new(a, cct);
-    let from_p = Xform::new(cct, z);
-    if inv {
-        list.reverse();
-    }
-    map_px(&mut b, |c| {
-        let mut v = to_p.apply(c).map(|x| x as f64);
-        for (cdl, li) in &list {
-            v = if *li != inv { cdl.invert(v, false) } else { cdl.apply(v, false) };
-        }
-        from_p.apply(v.map(|x| x as f32))
-    });
-    b
-}
-
-// ---- Color Profile Converter (Utility)
-
-pub const PROFILES: &[&str] = &["Project Working Space", "sRGB IEC61966-2.1", "HDTV (Rec. 709)", "Rec. 2020", "Display P3", "ACEScg", "ACES2065-1"];
-
-fn profile(ctx: &EffectCtx, i: u32) -> (Space, bool) {
-    let ws = |cs: ColorSpace| match cs {
-        ColorSpace::Srgb => sp("sRGB", REC709, D65, Tf::Srgb),
-        ColorSpace::Rec709 => sp("Rec.709", REC709, D65, Tf::Gamma(2.4)),
-        ColorSpace::Rec2020 => sp("Rec.2020", REC2020, D65, Tf::Gamma(2.4)),
-        ColorSpace::DisplayP3 => sp("Display P3", P3, D65, Tf::Srgb),
-        ColorSpace::AcesCg => ACES_CG,
-        ColorSpace::Aces2065 => ACES2065_1,
-        // HDR encodings are output spaces, never a working space.
-        ColorSpace::Rec2100Pq | ColorSpace::Rec2100Hlg => sp("Rec.2020", REC2020, D65, Tf::Gamma(2.4)),
-    };
-    match i {
-        0 => (ws(ctx.env.working_space.unwrap_or(ColorSpace::Srgb)), ctx.env.working_linear),
-        1 => (ws(ColorSpace::Srgb), false),
-        2 => (ws(ColorSpace::Rec709), false),
-        3 => (ws(ColorSpace::Rec2020), false),
-        4 => (ws(ColorSpace::DisplayP3), false),
-        5 => (ACES_CG, true),
-        _ => (ACES2065_1, true),
-    }
-}
-
-/// Gamut compression for the perceptual intent: pull out-of-gamut (negative) colours toward
-/// their luminance just enough to bring every channel to ≥ 0, rolling off smoothly.
-fn compress_gamut(c: [f64; 3], luma: [f64; 3]) -> [f64; 3] {
-    let l = c[0] * luma[0] + c[1] * luma[1] + c[2] * luma[2];
-    if l <= 0.0 {
-        return c.map(|v| v.max(0.0));
-    }
-    let mn = c.iter().cloned().fold(f64::INFINITY, f64::min);
-    if mn >= 0.0 {
-        return c;
-    }
-    // Fraction of the way toward grey that reaches zero on the most negative channel.
-    let t = (l / (l - mn)).clamp(0.0, 1.0);
-    c.map(|v| l + (v - l) * t)
-}
-
-fn profile_converter(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let (inp, in_lin_default) = profile(ctx, ctx.params.e("inputProfile"));
-    let (out, out_lin_default) = profile(ctx, ctx.params.e("outputProfile"));
-    let in_lin = ctx.params.b("linearizeInputProfile") || in_lin_default && ctx.params.e("inputProfile") == 0;
-    let out_lin = ctx.params.b("linearizeOutputProfile") || out_lin_default && ctx.params.e("outputProfile") == 0;
-    let intent = ctx.params.e("intent");
-    let dec = if in_lin { Tf::Linear } else { inp.tf };
-    let enc = if out_lin { Tf::Linear } else { out.tf };
-    // Absolute colorimetric keeps the source white (no adaptation); the others adapt.
-    let m = if intent == 3 { mul(&invert(&out.to_ref(false)), &inp.to_ref(false)) } else { matrix(&inp, &out) };
-    let identity = dec == enc && (0..3).all(|i| (0..3).all(|j| (m[i][j] - IDENTITY[i][j]).abs() < 1e-9));
-    if identity {
-        return b;
-    }
-    let out_luma = out.to_ref(true)[1];
-    map_px(&mut b, |c| {
-        let l = c.map(|v| dec.decode(v as f64));
-        let mut o = mul_vec(&m, l);
-        match intent {
-            0 => o = compress_gamut(o, out_luma),
-            2 => o = o.map(|v| v.max(0.0)),
-            _ => {}
-        }
-        o.map(|v| enc.encode(v) as f32)
-    });
-    b
-}
-
-// ---- Colour programs (the GPU compositor's colour-management kernels)
-
-/// One per-pixel step of a colour transform, in the order the CPU effect applies them (see
-/// [`color_program`]).
-#[derive(Clone, Debug)]
-pub enum ColorOp {
-    /// Transfer function, encoded → linear.
-    Decode(Tf),
-    /// Transfer function, linear → encoded.
-    Encode(Tf),
-    /// Linear-RGB matrix.
-    Matrix([[f32; 3]; 3]),
-    /// ASC CDL (forward or exact inverse; `clamp` = the v1.2 style).
-    Cdl { cdl: Cdl, clamp: bool, inverse: bool },
-    /// The Tone Mapped view's roll-off (or its inverse).
-    Tonemap { inverse: bool },
-    /// Color Profile Converter's perceptual gamut compression toward luminance `luma`.
-    Gamut([f64; 3]),
-    /// Negative channels to 0 (the saturation intent).
-    Max0,
-    /// A LUT (0 nearest, 1 trilinear, 2 tetrahedral) with an optional per-channel shaper, forward
-    /// or inverse (as `FileXform::apply`).
-    Lut { lut: Arc<Lut>, shaper: Option<Arc<[Vec<(f32, f32)>; 3]>>, interp: u32, inverse: bool },
-    /// `m × (c + pre) + post` (a custom config's MatrixTransform and RangeTransform).
-    Affine { m: [[f32; 3]; 3], pre: [f32; 3], post: [f32; 3] },
-    /// `max(c, 0) ^ p` per channel (ExponentTransform).
-    Pow([f32; 3]),
-    /// LogTransform / LogAffineTransform, forward or inverse (as `ocio_config::Xf::apply`).
-    LogAffine { base: f32, log_slope: [f32; 3], log_offset: [f32; 3], lin_slope: [f32; 3], lin_offset: [f32; 3], inverse: bool },
-    /// ExponentWithLinearTransform, forward (decode) or inverse (as
-    /// [`crate::ocio_config::moncurve`]).
-    MonCurve { gamma: [f32; 3], offset: [f32; 3], inverse: bool, mirror: bool },
-    /// Clamp each channel to `lo..=hi` (a clamping RangeTransform; ±`f32::MAX` = unbounded).
-    Clamp { lo: [f32; 3], hi: [f32; 3] },
-}
-
-/// The ops of a matrix-and-offset transform (MatrixTransform, `.spimtx`), forward or inverse
-/// (as [`crate::ocio_config::matrix_apply`]).
-fn matrix_ops(m: &[f64; 16], offset: &[f64; 4], inverse: bool, ops: &mut Vec<ColorOp>) {
-    if !inverse {
-        let m = [0, 1, 2].map(|r| [m[r * 4] as f32, m[r * 4 + 1] as f32, m[r * 4 + 2] as f32]);
-        ops.push(ColorOp::Affine { m, pre: [0.0; 3], post: [offset[0] as f32, offset[1] as f32, offset[2] as f32] });
-    } else if let Some(inv) = crate::ocio_config::mat3_inverse(m) {
-        let m = inv.map(|r| r.map(|v| v as f32));
-        ops.push(ColorOp::Affine { m, pre: [-offset[0] as f32, -offset[1] as f32, -offset[2] as f32], post: [0.0; 3] });
-    }
-}
-
-/// The ops of a LUT / CDL / matrix file transform (as [`FileXform::apply`]).
-fn file_ops(x: &FileXform, interp: u32, inverse: bool, ccc_id: &str, ops: &mut Vec<ColorOp>) {
-    match x {
-        FileXform::Cdl(list) => {
-            let cdl = list.iter().find(|(i, _)| !ccc_id.is_empty() && i == ccc_id).or(list.first()).map(|(_, c)| *c).unwrap_or_default();
-            ops.push(ColorOp::Cdl { cdl, clamp: true, inverse });
-        }
-        FileXform::Lut { lut, shaper } => {
-            ops.push(ColorOp::Lut { lut: Arc::new(lut.clone()), shaper: shaper.clone().map(Arc::new), interp, inverse });
-        }
-        FileXform::Matrix { m, offset } => matrix_ops(m, offset, inverse, ops),
-    }
-}
-
-/// The ops of a custom config's transform `x` (as `Xf::apply`).
-fn config_xf_ops(x: &crate::ocio_config::Xf, inverse: bool, ops: &mut Vec<ColorOp>) {
-    use crate::ocio_config::Xf;
-    let f3 = |v: &[f64; 3]| v.map(|x| x as f32);
-    match x {
-        Xf::Inverse(x) => config_xf_ops(x, !inverse, ops),
-        Xf::Matrix { m, offset } => matrix_ops(m, offset, inverse, ops),
-        Xf::File { xf: Some(x), interp, ccc, .. } => file_ops(x, *interp, inverse, ccc, ops),
-        Xf::ExponentLinear { gamma, offset, mirror } => ops.push(ColorOp::MonCurve { gamma: f3(gamma), offset: f3(offset), inverse, mirror: *mirror }),
-        // A BuiltinTransform's curve: forward decodes.
-        Xf::Curve(tf) => ops.push(if inverse { ColorOp::Encode(*tf) } else { ColorOp::Decode(*tf) }),
-        Xf::Named(_) => {}
-        Xf::File { xf: None, .. } | Xf::Unsupported(_) => {}
-        Xf::Exponent(e) => ops.push(ColorOp::Pow([0, 1, 2].map(|k| (if inverse { 1.0 / e[k].max(1e-9) } else { e[k] }) as f32))),
-        Xf::Log { base } => {
-            ops.push(ColorOp::LogAffine { base: *base as f32, log_slope: [1.0; 3], log_offset: [0.0; 3], lin_slope: [1.0; 3], lin_offset: [0.0; 3], inverse })
-        }
-        Xf::LogAffine { base, log_slope, log_offset, lin_slope, lin_offset } => ops.push(ColorOp::LogAffine {
-            base: *base as f32,
-            log_slope: f3(log_slope),
-            log_offset: f3(log_offset),
-            lin_slope: f3(lin_slope),
-            lin_offset: f3(lin_offset),
-            inverse,
-        }),
-        Xf::Cdl(cdl) => ops.push(ColorOp::Cdl { cdl: *cdl, clamp: true, inverse }),
-        Xf::Range(r) => {
-            let (k, off, lo, hi) = r.parts(inverse);
-            let k = k as f32;
-            ops.push(ColorOp::Affine { m: [[k, 0.0, 0.0], [0.0, k, 0.0], [0.0, 0.0, k]], pre: [0.0; 3], post: [off as f32; 3] });
-            if lo.is_finite() || hi.is_finite() {
-                let bound = |v: f64| (v as f32).clamp(-f32::MAX, f32::MAX);
-                ops.push(ColorOp::Clamp { lo: [bound(lo); 3], hi: [bound(hi); 3] });
-            }
-        }
-        Xf::Group(list) => {
-            if inverse {
-                list.iter().rev().for_each(|x| config_xf_ops(x, true, ops));
-            } else {
-                list.iter().for_each(|x| config_xf_ops(x, false, ops));
-            }
-        }
-    }
-}
-
-/// How a colour program meets premultiplied pixels.
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum Straight {
-    /// `unpremul` (colour 0 below alpha 1e-6); fully transparent pixels untouched (OCIO effects).
-    Unpremul,
-    /// Colour ÷ alpha; fully transparent pixels untouched (`Image::map_straight`, Apply Color LUT).
-    Divide,
-}
-
-fn xform_ops(x: &Xform, ops: &mut Vec<ColorOp>) {
-    if x.dec != Tf::Linear {
-        ops.push(ColorOp::Decode(x.dec));
-    }
-    if !x.ident {
-        ops.push(ColorOp::Matrix(x.m));
-    }
-    if x.enc != Tf::Linear {
-        ops.push(ColorOp::Encode(x.enc));
-    }
-}
-
-/// Effect `id`'s per-pixel transform as a list of [`ColorOp`]s that reproduces the CPU effect
-/// (empty = the layer passes through; custom OCIO configs compile their transforms too). `None`
-/// for another effect.
-pub fn color_program(id: &str, ctx: &EffectCtx) -> Option<(Vec<ColorOp>, Straight)> {
-    let pr = ctx.params;
-    let mut ops = vec![];
-    // Configuration ▸ Custom compiles the config's transforms (a config that can't be read, or
-    // names unknown spaces, passes the pixels through).
-    match custom_xf(id, pr) {
-        Ok(None) => {}
-        Ok(Some(xf)) => {
-            config_xf_ops(&xf, false, &mut ops);
-            return Some((ops, Straight::Unpremul));
-        }
-        Err(_) => return Some((ops, Straight::Unpremul)),
-    }
-    match id {
-        "ec.utility.applylut" => {
-            if let Some(lut) = crate::utility::load_lut(pr.s("lut")) {
-                ops.push(ColorOp::Lut { lut, shaper: None, interp: 2, inverse: false });
-            }
-            return Some((ops, Straight::Divide));
-        }
-        "ec.color.ociocolorspace" => {
-            let (a, z) = (space_at(pr.e("source")), space_at(pr.e("destination")));
-            let (a, z) = if pr.e("direction") == 1 { (z, a) } else { (a, z) };
-            if a.name != z.name {
-                xform_ops(&Xform::new(a, z), &mut ops);
-            }
-        }
-        "ec.color.ociocdl" => {
-            let cdl = cdl_from_params(pr);
-            if cdl != Cdl::default() {
-                ops.push(ColorOp::Cdl { cdl, clamp: pr.e("style") == 0, inverse: pr.e("direction") == 1 });
-            }
-        }
-        "ec.color.ociodisplay" => {
-            let input = space_at(pr.e("source"));
-            let (display, view, inverse) = (pr.e("display") as usize, pr.e("view") as usize, pr.e("direction") == 1);
-            let (_, prims, tf) = DISPLAYS[display.min(DISPLAYS.len() - 1)];
-            if view != 2 && !input.raw {
-                let disp = Space { name: "display", prims: Some((prims, D65)), tf: Tf::Linear, raw: false };
-                let lin = Space { tf: Tf::Linear, ..*input };
-                if !inverse {
-                    ops.push(ColorOp::Decode(input.tf));
-                    xform_ops(&Xform::new(&lin, &disp), &mut ops);
-                    if view == 1 {
-                        ops.push(ColorOp::Tonemap { inverse: false });
-                    }
-                    ops.push(ColorOp::Encode(tf));
-                } else {
-                    ops.push(ColorOp::Decode(tf));
-                    if view == 1 {
-                        ops.push(ColorOp::Tonemap { inverse: true });
-                    }
-                    xform_ops(&Xform::new(&disp, &lin), &mut ops);
-                    ops.push(ColorOp::Encode(input.tf));
-                }
-            }
-        }
-        "ec.color.ociofile" => {
-            if let Some(x) = load_file(pr.s("file")) {
-                let interp = match pr.e("interpolation") {
-                    0 => 0,
-                    1 => 1,
-                    _ => 2,
-                };
-                file_ops(&x, interp, pr.e("direction") == 1, pr.s("cccId"), &mut ops);
-            }
-        }
-        "ec.color.ociolook" => {
-            let mut list = parse_looks(pr.s("looks"));
-            let pick = pr.e("look");
-            if pick > 0
-                && let Some((_, c)) = looks().get(pick as usize - 1)
-            {
-                list.insert(0, (*c, false));
-            }
-            if !list.is_empty() {
-                let (src, dst) = (space_at(pr.e("source")), space_at(pr.e("destination")));
-                let inv = pr.e("direction") == 1;
-                let cct = &ACES_CCT;
-                let (a, z) = if inv { (dst, src) } else { (src, dst) };
-                if inv {
-                    list.reverse();
-                }
-                xform_ops(&Xform::new(a, cct), &mut ops);
-                for (cdl, li) in &list {
-                    ops.push(ColorOp::Cdl { cdl: *cdl, clamp: false, inverse: *li != inv });
-                }
-                xform_ops(&Xform::new(cct, z), &mut ops);
-            }
-        }
-        "ec.utility.colorprofileconverter" => {
-            let (inp, in_lin_default) = profile(ctx, pr.e("inputProfile"));
-            let (out, out_lin_default) = profile(ctx, pr.e("outputProfile"));
-            let in_lin = pr.b("linearizeInputProfile") || in_lin_default && pr.e("inputProfile") == 0;
-            let out_lin = pr.b("linearizeOutputProfile") || out_lin_default && pr.e("outputProfile") == 0;
-            let intent = pr.e("intent");
-            let dec = if in_lin { Tf::Linear } else { inp.tf };
-            let enc = if out_lin { Tf::Linear } else { out.tf };
-            let m = if intent == 3 { mul(&invert(&out.to_ref(false)), &inp.to_ref(false)) } else { matrix(&inp, &out) };
-            let identity = dec == enc && (0..3).all(|i| (0..3).all(|j| (m[i][j] - IDENTITY[i][j]).abs() < 1e-9));
-            if !identity {
-                ops.push(ColorOp::Decode(dec));
-                ops.push(ColorOp::Matrix(m.map(|r| r.map(|v| v as f32))));
-                match intent {
-                    0 => ops.push(ColorOp::Gamut(out.to_ref(true)[1])),
-                    2 => ops.push(ColorOp::Max0),
-                    _ => {}
-                }
-                ops.push(ColorOp::Encode(enc));
-            }
-        }
-        _ => return None,
-    }
-    Some((ops, Straight::Unpremul))
-}
-
-// ---- Color Stabilizer
-
-/// Mean straight colour of a square (half-size `r` layer pixels) around layer point `pt`.
-fn sample_mean(b: &Buf, pt: [f64; 2], r: f64) -> [f64; 3] {
-    let (cx, cy) = b.to_px(pt);
-    let rr = (r * b.scale).max(0.5);
-    let (x0, x1) = ((cx - rr).floor().max(0.0) as i64, ((cx + rr).ceil() as i64).min(b.img.width as i64));
-    let (y0, y1) = ((cy - rr).floor().max(0.0) as i64, ((cy + rr).ceil() as i64).min(b.img.height as i64));
-    let mut acc = [0.0f64; 4];
-    for y in y0..y1 {
-        for x in x0..x1 {
-            let p = b.img.get(x, y);
-            for k in 0..4 {
-                acc[k] += p[k] as f64;
-            }
-        }
-    }
-    if acc[3] <= 1e-9 {
-        return [0.0; 3];
-    }
-    [acc[0] / acc[3], acc[1] / acc[3], acc[2] / acc[3]]
-}
-
-/// Monotone piecewise-quadratic curve through (0,0), three samples and (1,1) (linear between
-/// them is enough for a stabiliser and stays monotone).
-fn curve3(xs: [f64; 3], ys: [f64; 3], v: f64) -> f64 {
-    let mut pts = vec![(0.0, 0.0)];
-    let mut pairs: Vec<(f64, f64)> = xs.iter().cloned().zip(ys.iter().cloned()).collect();
-    pairs.sort_by(|a, b| a.0.total_cmp(&b.0));
-    for (x, y) in pairs {
-        if pts.last().is_some_and(|l| x > l.0 + 1e-4) && x < 1.0 - 1e-4 {
-            pts.push((x, y));
-        }
-    }
-    pts.push((1.0, 1.0));
-    let i = pts.partition_point(|p| p.0 < v).clamp(1, pts.len() - 1);
-    let (a, c) = (pts[i - 1], pts[i]);
-    a.1 + (c.1 - a.1) * (v - a.0) / (c.0 - a.0).max(1e-9)
-}
-
-/// Color Stabilizer's correction of buffer `b` as one piecewise-linear map per channel (points
-/// with increasing x; the end segments extend), the same maps `color_stabilizer` applies.
-/// `None` without a host or reference frame (the layer passes through). (The GPU effect.)
-pub fn color_stabilizer_maps(ctx: &EffectCtx, b: &Buf) -> Option<[Vec<(f64, f64)>; 3]> {
-    let reference = ctx.env.host?.self_at(ctx.params.f("referenceFrame"), ctx.env.effect_index)?;
-    let r = ctx.params.f("sampleSize").max(0.5);
-    let pts = [ctx.params.v2("blackPoint"), ctx.params.v2("midPoint"), ctx.params.v2("whitePoint")];
-    let cur = pts.map(|pt| sample_mean(b, pt, r));
-    let refv = pts.map(|pt| sample_mean(&reference, pt, r));
-    let mode = ctx.params.e("stabilize");
-    Some([0, 1, 2].map(|k| {
-        let offset = |c0: f64, r0: f64| vec![(0.0, r0 - c0), (1.0, 1.0 + r0 - c0)];
-        match mode {
-            0 => offset(cur[0][k], refv[0][k]),
-            1 => {
-                let (c0, c1, r0, r1) = (cur[0][k], cur[2][k], refv[0][k], refv[2][k]);
-                if (c1 - c0).abs() < 1e-6 {
-                    offset(c0, r0)
-                } else if c0 < c1 {
-                    vec![(c0, r0), (c1, r1)]
-                } else {
-                    vec![(c1, r1), (c0, r0)]
-                }
-            }
-            _ => {
-                let mut v = vec![(0.0, 0.0)];
-                let mut pairs: Vec<(f64, f64)> = (0..3).map(|i| (cur[i][k], refv[i][k])).collect();
-                pairs.sort_by(|a, b| a.0.total_cmp(&b.0));
-                for (x, y) in pairs {
-                    if v.last().is_some_and(|l| x > l.0 + 1e-4) && x < 1.0 - 1e-4 {
-                        v.push((x, y));
-                    }
-                }
-                v.push((1.0, 1.0));
-                v
-            }
-        }
-    }))
-}
-
-fn color_stabilizer(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let Some(host) = ctx.env.host else { return b };
-    let Some(reference) = host.self_at(ctx.params.f("referenceFrame"), ctx.env.effect_index) else { return b };
-    let r = ctx.params.f("sampleSize").max(0.5);
-    let pts = [ctx.params.v2("blackPoint"), ctx.params.v2("midPoint"), ctx.params.v2("whitePoint")];
-    let cur = pts.map(|pt| sample_mean(&b, pt, r));
-    let refv = pts.map(|pt| sample_mean(&reference, pt, r));
-    let mode = ctx.params.e("stabilize");
-    map_px(&mut b, |c| {
-        [0, 1, 2].map(|k| {
-            let v = c[k] as f64;
-            let o = match mode {
-                // Brightness: one sample (black point) — offset each channel.
-                0 => v + refv[0][k] - cur[0][k],
-                // Levels: black and white samples — linear map per channel.
-                1 => {
-                    let (c0, c1, r0, r1) = (cur[0][k], cur[2][k], refv[0][k], refv[2][k]);
-                    if (c1 - c0).abs() < 1e-6 { v + r0 - c0 } else { r0 + (v - c0) * (r1 - r0) / (c1 - c0) }
-                }
-                // Curves: three samples — a curve through them per channel.
-                _ => curve3([cur[0][k], cur[1][k], cur[2][k]], [refv[0][k], refv[1][k], refv[2][k]], v),
-            };
-            o as f32
-        })
-    });
-    b
-}
-
-fn sl(lo: f64, hi: f64, smin: f64, smax: f64) -> ParamUi {
-    slider(lo, hi, smin, smax, 3)
-}
-
-pub fn specs() -> Vec<EffectSpec> {
-    let cc = "Color Correction";
-    let srgb = SPACES.iter().position(|s| s.name == "sRGB").unwrap_or(0) as u32;
-    let lin709 = SPACES.iter().position(|s| s.name == "Linear Rec.709 (sRGB)").unwrap_or(0) as u32;
-    let acescg = SPACES.iter().position(|s| s.name == "ACEScg").unwrap_or(0) as u32;
-    let mut look_opts = vec!["None"];
-    look_opts.extend(looks().iter().map(|(n, _)| *n));
-    vec![
-        spec(
-            "ec.color.ociocdl",
-            "OCIO CDL Transform",
-            cc,
-            vec![
-                p("slopeRed", "Slope Red", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
-                p("slopeGreen", "Slope Green", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
-                p("slopeBlue", "Slope Blue", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
-                p("offsetRed", "Offset Red", num(0.0), sl(-100.0, 100.0, -1.0, 1.0)),
-                p("offsetGreen", "Offset Green", num(0.0), sl(-100.0, 100.0, -1.0, 1.0)),
-                p("offsetBlue", "Offset Blue", num(0.0), sl(-100.0, 100.0, -1.0, 1.0)),
-                p("powerRed", "Power Red", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
-                p("powerGreen", "Power Green", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
-                p("powerBlue", "Power Blue", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
-                p("saturation", "Saturation", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
-                p("style", "Style", Value::Enum(0), popup(&["ASC CDL v1.2", "No Clamp"])),
-                direction(),
-            ],
-            ocio_cdl,
-        ),
-        spec(
-            "ec.color.ociocolorspace",
-            "OCIO Color Space Transform",
-            cc,
-            vec![
-                p("config", "Configuration", Value::Enum(0), popup(CONFIGS)),
-                p("configFile", "Config File (.ocio)", Value::Str(String::new()), crate::file_ui(&["ocio"])),
-                space_param("source", "Source", lin709),
-                p("sourceName", "Source (config name)", Value::Str(String::new()), ParamUi::Text),
-                space_param("destination", "Destination", srgb),
-                p("destinationName", "Destination (config name)", Value::Str(String::new()), ParamUi::Text),
-                direction(),
-            ],
-            ocio_cst,
-        ),
-        spec(
-            "ec.color.ociodisplay",
-            "OCIO Display Transform",
-            cc,
-            vec![
-                p("config", "Configuration", Value::Enum(0), popup(CONFIGS)),
-                p("configFile", "Config File (.ocio)", Value::Str(String::new()), crate::file_ui(&["ocio"])),
-                space_param("source", "Input Color Space", lin709),
-                p("sourceName", "Source (config name)", Value::Str(String::new()), ParamUi::Text),
-                p("display", "Display Device", Value::Enum(0), popup(&DISPLAYS.iter().map(|d| d.0).collect::<Vec<_>>())),
-                p("displayName", "Display (config name)", Value::Str(String::new()), ParamUi::Text),
-                p("view", "View Transform", Value::Enum(0), popup(VIEWS)),
-                p("viewName", "View (config name)", Value::Str(String::new()), ParamUi::Text),
-                direction(),
-            ],
-            ocio_display,
-        ),
-        // `file`: a path to a .cube/.3dl/.csp/.cc/.ccc/.cdl file, or the file's text itself.
-        spec(
-            "ec.color.ociofile",
-            "OCIO File Transform",
-            cc,
-            vec![
-                p("file", "File", Value::Str(String::new()), crate::file_ui(&["cube", "3dl", "csp", "cc", "ccc", "cdl", "spi1d", "spi3d", "spimtx"])),
-                p("cccId", "CCC ID", Value::Str(String::new()), ParamUi::Text),
-                p("interpolation", "Interpolation", Value::Enum(3), popup(&["Nearest", "Linear", "Tetrahedral", "Best"])),
-                direction(),
-            ],
-            ocio_file,
-        ),
-        spec(
-            "ec.color.ociolook",
-            "OCIO Look Transform",
-            cc,
-            vec![
-                p("config", "Configuration", Value::Enum(0), popup(&["Built-in (EffectCraft minimal)"])),
-                space_param("source", "Source", acescg),
-                space_param("destination", "Destination", acescg),
-                p("look", "Look", Value::Enum(0), popup(&look_opts)),
-                p("looks", "Looks", Value::Str(String::new()), ParamUi::Text),
-                direction(),
-            ],
-            ocio_look,
-        ),
-        spec(
-            "ec.color.colorstabilizer",
-            "Color Stabilizer",
-            cc,
-            vec![
-                // The pivot frame (After Effects' Set Frame button stores it).
-                p("referenceFrame", "Reference Frame (s)", num(0.0), slider(-100000.0, 100000.0, 0.0, 60.0, 2)),
-                p("stabilize", "Stabilize", Value::Enum(0), popup(&["Brightness", "Levels", "Curves"])),
-                p("blackPoint", "Black Point", Value::Vec2([0.25, 0.75]), ParamUi::Point),
-                p("midPoint", "Mid Point", Value::Vec2([0.5, 0.5]), ParamUi::Point),
-                p("whitePoint", "White Point", Value::Vec2([0.75, 0.25]), ParamUi::Point),
-                p("sampleSize", "Sample Size", num(5.0), slider(1.0, 100.0, 1.0, 50.0, 0)),
-            ],
-            color_stabilizer,
-        ),
-        spec(
-            "ec.utility.colorprofileconverter",
-            "Color Profile Converter",
-            "Utility",
-            vec![
-                p("inputProfile", "Input Profile", Value::Enum(0), popup(PROFILES)),
-                p("linearizeInputProfile", "Linearize Input Profile", Value::Bool(false), ParamUi::Checkbox),
-                p("outputProfile", "Output Profile", Value::Enum(1), popup(PROFILES)),
-                p("linearizeOutputProfile", "Linearize Output Profile", Value::Bool(false), ParamUi::Checkbox),
-                p("intent", "Intent", Value::Enum(1), popup(&["Perceptual", "Relative Colorimetric", "Saturation", "Absolute Colorimetric"])),
-                // Our built-in profiles share a zero black point and none is scene-referred, so
-                // these two are kept for compatibility and do not change the result.
-                p("useBlackPointCompensation", "Use Black Point Compensation", Value::Bool(true), ParamUi::Checkbox),
-                p("sceneRefCompensation", "Scene-ref. Profile Compensation", Value::Enum(2), popup(&["On", "Off", "Use Project Setting"])),
-            ],
-            profile_converter,
-        ),
-    ]
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::{EffectEnv, EffectHost, Image, LayerPixels, run_fx};
-
-    fn close(a: M3, b: M3, tol: f64) {
-        for i in 0..3 {
-            for j in 0..3 {
-                assert!((a[i][j] - b[i][j]).abs() < tol, "{a:?} vs {b:?}");
-            }
-        }
-    }
-
-    #[test]
-    fn aces_matrices_match_published_values() {
-        let ap0 = space_by_name("ACES2065-1").unwrap();
-        let ap1 = space_by_name("ACEScg").unwrap();
-        // Academy S-2014-004 AP0 → AP1.
-        close(
-            matrix(ap0, ap1),
-            [
-                [1.451_439_316_1, -0.236_510_746_9, -0.214_928_569_3],
-                [-0.076_553_773_4, 1.176_229_699_8, -0.099_675_926_4],
-                [0.008_316_148_4, -0.006_032_449_8, 0.997_716_301_4],
-            ],
-            2e-4,
-        );
-        // ACEScg → linear Rec.709 with Bradford adaptation (published ACES config value).
-        let lin = space_by_name("Linear Rec.709 (sRGB)").unwrap();
-        close(matrix(ap1, lin), [[1.705_05, -0.621_79, -0.083_26], [-0.130_26, 1.140_80, -0.010_55], [-0.024_00, -0.128_97, 1.152_97]], 2e-3);
-        // White maps to white.
-        let w = mul_vec(&matrix(ap1, lin), [1.0, 1.0, 1.0]);
-        assert!(w.iter().all(|v| (v - 1.0).abs() < 1e-3), "{w:?}");
-    }
-
-    #[test]
-    fn transfer_functions_round_trip() {
-        for tf in [Tf::Srgb, Tf::Gamma(2.4), Tf::AcesCct, Tf::Pq] {
-            for v in [0.0, 0.001, 0.18, 0.5, 1.0, 4.0] {
-                let r = tf.decode(tf.encode(v));
-                assert!((r - v).abs() < 1e-6 * v.max(1.0), "{tf:?} {v} {r}");
-            }
-        }
-        // ACEScct of 18 % grey (S-2016-001).
-        assert!((Tf::AcesCct.encode(0.18) - 0.413_588).abs() < 1e-5);
-        // PQ: 100 nits (1.0) encodes to ≈ 0.508.
-        assert!((Tf::Pq.encode(1.0) - 0.508).abs() < 1e-3);
-    }
-
-    #[test]
-    fn color_space_transform_effect_round_trips() {
-        let img = Image::filled(4, 4, [0.2, 0.5, 0.7, 1.0]);
-        let srgb = SPACES.iter().position(|s| s.name == "sRGB").unwrap() as u32;
-        let cg = SPACES.iter().position(|s| s.name == "ACEScg").unwrap() as u32;
-        let a = run_fx("ec.color.ociocolorspace", &[("source", Value::Enum(srgb)), ("destination", Value::Enum(cg))], img.clone(), 0.0, EffectEnv::default());
-        assert_ne!(a.img.data, img.data);
-        let b = run_fx("ec.color.ociocolorspace", &[("source", Value::Enum(cg)), ("destination", Value::Enum(srgb))], a.img.clone(), 0.0, EffectEnv::default());
-        let c = run_fx(
-            "ec.color.ociocolorspace",
-            &[("source", Value::Enum(srgb)), ("destination", Value::Enum(cg)), ("direction", Value::Enum(1))],
-            a.img,
-            0.0,
-            EffectEnv::default(),
-        );
-        for (x, y) in b.img.data.iter().zip(&img.data).chain(c.img.data.iter().zip(&img.data)) {
-            assert!((0..4).all(|k| (x[k] - y[k]).abs() < 1e-4), "{x:?} {y:?}");
-        }
-    }
-
-    #[test]
-    fn cdl_math() {
-        let cdl = Cdl { slope: [1.2, 1.0, 0.8], offset: [0.05, 0.0, -0.02], power: [1.1, 1.0, 0.9], sat: 0.8 };
-        let c = [0.3, 0.5, 0.7];
-        // Hand computation of the v1.2 formula.
-        let sop = [(0.3f64 * 1.2 + 0.05).powf(1.1), 0.5, (0.7f64 * 0.8 - 0.02).powf(0.9)];
-        let l = sop[0] * 0.2126 + sop[1] * 0.7152 + sop[2] * 0.0722;
-        let want = sop.map(|v| l + 0.8 * (v - l));
-        let got = cdl.apply(c, true);
-        for k in 0..3 {
-            assert!((got[k] - want[k]).abs() < 1e-12);
-        }
-        let back = cdl.invert(got, true);
-        for k in 0..3 {
-            assert!((back[k] - c[k]).abs() < 1e-9);
-        }
-        // v1.2 clamps, No Clamp keeps negatives.
-        let neg = Cdl { offset: [-0.5; 3], ..Cdl::default() };
-        assert_eq!(neg.apply([0.2; 3], true), [0.0; 3]);
-        assert!((neg.apply([0.2; 3], false)[0] + 0.3).abs() < 1e-12);
-        let img = Image::filled(2, 2, [0.3, 0.5, 0.7, 1.0]);
-        let out = run_fx("ec.color.ociocdl", &[("slopeRed", num(1.2)), ("offsetRed", num(0.05)), ("powerRed", num(1.1))], img, 0.0, EffectEnv::default());
-        let r = (0.3f64 * 1.2 + 0.05).powf(1.1);
-        assert!((out.img.get(0, 0)[0] as f64 - r).abs() < 1e-5);
-    }
-
-    fn identity_lattice(n: usize, f: impl Fn([f32; 3]) -> [f32; 3]) -> Vec<[f32; 3]> {
-        let mut v = vec![];
-        for b in 0..n {
-            for g in 0..n {
-                for r in 0..n {
-                    let s = (n - 1) as f32;
-                    v.push(f([r as f32 / s, g as f32 / s, b as f32 / s]));
-                }
-            }
-        }
-        v
-    }
-
-    /// Sony Imageworks `.spi1d`, `.spi3d` and `.spimtx` (Blender's configs use them, #410), and
-    /// malformed ones rejected without panicking.
-    #[test]
-    fn spi_files_parse() {
-        let spi1d = "Version 1\nFrom 0.0 2.0\nLength 3\nComponents 1\n{\n0.0\n0.25\n1.0\n}\n";
-        let x = parse_file(spi1d, "spi1d").unwrap();
-        let o = x.apply([1.0, 0.5, 2.0], 1, false, "");
-        assert!((o[0] - 0.25).abs() < 1e-6 && (o[1] - 0.125).abs() < 1e-6 && (o[2] - 1.0).abs() < 1e-6, "{o:?}");
-        let back = x.apply(o, 1, true, "");
-        assert!((back[0] - 1.0).abs() < 1e-5 && (back[2] - 2.0).abs() < 1e-5, "{back:?}");
-        let three = parse_spi1d("Version 1\nFrom 0 1\nLength 2\nComponents 3\n{\n0 0 0\n1 0.5 2\n}\n").unwrap();
-        assert_eq!(three.d1, vec![[0.0; 3], [1.0, 0.5, 2.0]]);
-        let mut spi3d = String::from("SPILUT 1.0\n3 3\n2 2 2\n");
-        for (r, g, b) in (0..8).map(|i| (i & 1, (i >> 1) & 1, i >> 2)) {
-            spi3d += &format!("{r} {g} {b} {} {} {}\n", r as f32 * 0.5, g, b);
-        }
-        let x = parse_file(&spi3d, "spi3d").unwrap();
-        let o = x.apply([1.0, 0.5, 0.25], 1, false, "");
-        assert!((o[0] - 0.5).abs() < 1e-6 && (o[1] - 0.5).abs() < 1e-6 && (o[2] - 0.25).abs() < 1e-6, "{o:?}");
-        let m = parse_file("2 0 0 6553.5\n0 1 0 0\n0 0 1 0\n", "spimtx").unwrap();
-        let o = m.apply([0.25, 0.5, 1.0], 1, false, "");
-        assert!((o[0] - 0.6).abs() < 1e-6 && o[1] == 0.5 && o[2] == 1.0, "{o:?}");
-        assert!((m.apply(o, 1, true, "")[0] - 0.25).abs() < 1e-6);
-        for bad in [
-            "Version 1\nFrom 0 1\nLength 99999999999\nComponents 1\n{\n0\n}\n",
-            "Version 1\nFrom 1 0\nLength 2\nComponents 1\n{\n0\n1\n}\n",
-            "Version 1\nFrom 0 1\nLength 3\nComponents 1\n{\n0\n1\n}\n",
-            "Version 1\nFrom 0 1\nLength 2\nComponents 2\n{\n0 0\n1 1\n}\n",
-        ] {
-            assert!(parse_spi1d(bad).is_none(), "{bad}");
-        }
-        assert!(parse_spi3d("SPILUT 1.0\n3 3\n4000 4000 4000\n").is_none());
-        assert!(parse_spi3d("SPILUT 1.0\n3 3\n2 2 2\n9 0 0 1 1 1\n").is_none());
-        assert!(parse_spi3d("SPILUT 1.0\n3 3\n2 2 2\n0 0 0 1 1 1\n").is_none(), "incomplete lattice");
-        assert!(parse_spimtx("1 0 0\n0 1 0\n").is_none());
-        assert!(parse_spimtx("NaN 0 0 0 0 1 0 0 0 0 1 0").is_none());
-    }
-
-    #[test]
-    fn lut_files_parse_and_interpolate() {
-        // .cube with a non-linear lattice: trilinear between lattice points.
-        let f = |c: [f32; 3]| [c[0] * c[0], c[1], 1.0 - c[2]];
-        let mut cube = String::from("LUT_3D_SIZE 3\n");
-        for r in identity_lattice(3, f) {
-            cube += &format!("{} {} {}\n", r[0], r[1], r[2]);
-        }
-        let Some(FileXform::Lut { lut, .. }) = parse_file(&cube, "cube") else { panic!() };
-        // Trilinear between 0.5 (0.25) and 1.0 (1.0) at 0.75 → 0.625.
-        let o = lut.apply_interp([0.75, 0.3, 0.2], 1);
-        assert!((o[0] - 0.625).abs() < 1e-6 && (o[1] - 0.3).abs() < 1e-6 && (o[2] - 0.8).abs() < 1e-6, "{o:?}");
-        // Nearest snaps.
-        assert_eq!(lut.apply_interp([0.74, 0.0, 0.0], 0)[0], 0.25);
-        // .3dl (blue fastest, 10-bit integers, mesh line).
-        let mut tdl = String::from("0 511 1023\n");
-        for r in 0..3 {
-            for g in 0..3 {
-                for b in 0..3 {
-                    let v = [r, g, b].map(|i| i as f64 * 511.5);
-                    tdl += &format!("{} {} {}\n", v[0].round(), v[1].round(), (1023.0 - v[2]).round());
-                }
-            }
-        }
-        let Some(FileXform::Lut { lut, .. }) = parse_file(&tdl, "3dl") else { panic!() };
-        let o = lut.apply_interp([0.25, 0.5, 0.25], 1);
-        assert!((o[0] - 0.25).abs() < 2e-3 && (o[1] - 0.5).abs() < 2e-3 && (o[2] - 0.75).abs() < 2e-3, "{o:?}");
-        // .csp with a squaring pre-LUT on red and an identity 2³ lattice.
-        let mut csp = String::from("CSPLUTV100\n3D\n\n3\n0 0.5 1\n0 0.25 1\n2\n0 1\n0 1\n2\n0 1\n0 1\n\n2 2 2\n");
-        for r in identity_lattice(2, |c| c) {
-            csp += &format!("{} {} {}\n", r[0], r[1], r[2]);
-        }
-        let x = parse_file(&csp, "csp").unwrap();
-        let o = x.apply([0.5, 0.4, 0.6], 2, false, "");
-        assert!((o[0] - 0.25).abs() < 1e-6 && (o[1] - 0.4).abs() < 1e-6, "{o:?}");
-        let inv = x.apply(o, 2, true, "");
-        assert!((inv[0] - 0.5).abs() < 1e-4, "{inv:?}");
-        // CDL collection: pick by id.
-        let ccc = r#"<ColorCorrectionCollection><ColorCorrection id="a"><SOPNode><Slope>2 2 2</Slope><Offset>0 0 0</Offset><Power>1 1 1</Power></SOPNode></ColorCorrection>
-            <ColorCorrection id='b'><SOPNode><Slope>0.5 0.5 0.5</Slope></SOPNode><SatNode><Saturation>1</Saturation></SatNode></ColorCorrection></ColorCorrectionCollection>"#;
-        let x = parse_file(ccc, "ccc").unwrap();
-        assert!((x.apply([0.4; 3], 2, false, "b")[0] - 0.2).abs() < 1e-6);
-        assert!((x.apply([0.4; 3], 2, false, "a")[0] - 0.8).abs() < 1e-6);
-        assert!((x.apply([0.4; 3], 2, false, "")[0] - 0.8).abs() < 1e-6);
-        // Effect with inline content; inverse of a 3D lattice.
-        let img = Image::filled(2, 2, [0.6, 0.3, 0.2, 1.0]);
-        let out = run_fx("ec.color.ociofile", &[("file", Value::Str(cube.clone()))], img.clone(), 0.0, EffectEnv::default());
-        let back = run_fx("ec.color.ociofile", &[("file", Value::Str(cube)), ("direction", Value::Enum(1))], out.img, 0.0, EffectEnv::default());
-        assert!((back.img.get(0, 0)[0] - 0.6).abs() < 1e-3, "{:?}", back.img.get(0, 0));
-        assert!(parse_file("garbage", "3dl").is_none());
-    }
-
-    #[test]
-    fn display_and_look_transforms() {
-        // Linear 0.18 through the sRGB display / Standard view = sRGB encoding of 0.18.
-        let img = Image::filled(2, 2, [0.18, 0.18, 0.18, 1.0]);
-        let out = run_fx("ec.color.ociodisplay", &[], img.clone(), 0.0, EffectEnv::default());
-        assert!((out.img.get(0, 0)[0] as f64 - Tf::Srgb.encode(0.18)).abs() < 1e-5);
-        let back = run_fx("ec.color.ociodisplay", &[("direction", Value::Enum(1))], out.img, 0.0, EffectEnv::default());
-        assert!((back.img.get(0, 0)[0] - 0.18).abs() < 1e-5);
-        // Tone mapped view keeps highlights below 1.
-        let hot = Image::filled(1, 1, [8.0, 8.0, 8.0, 1.0]);
-        let tm = run_fx("ec.color.ociodisplay", &[("view", Value::Enum(1))], hot, 0.0, EffectEnv::default());
-        assert!(tm.img.get(0, 0)[0] < 1.0);
-        assert!((tonemap_inv(tonemap(3.0)) - 3.0).abs() < 1e-9);
-        // Looks: Warm raises red over blue; its inverse undoes it.
-        let grey = Image::filled(1, 1, [0.18, 0.18, 0.18, 1.0]);
-        let w = run_fx("ec.color.ociolook", &[("looks", Value::Str("Warm".into()))], grey.clone(), 0.0, EffectEnv::default());
-        let px = w.img.get(0, 0);
-        assert!(px[0] > px[2]);
-        let u = run_fx("ec.color.ociolook", &[("looks", Value::Str("-Warm".into()))], w.img, 0.0, EffectEnv::default());
-        assert!((u.img.get(0, 0)[0] - 0.18).abs() < 1e-4 && (u.img.get(0, 0)[2] - 0.18).abs() < 1e-4);
-        assert_eq!(parse_looks("Warm, -Cool, nope").len(), 2);
-    }
-
-    #[test]
-    fn profile_converter_converts_and_round_trips() {
-        let img = Image::filled(2, 2, [0.8, 0.4, 0.1, 1.0]);
-        // sRGB → Rec. 2020 (relative), then back.
-        let a = run_fx(
-            "ec.utility.colorprofileconverter",
-            &[("inputProfile", Value::Enum(1)), ("outputProfile", Value::Enum(3))],
-            img.clone(),
-            0.0,
-            EffectEnv::default(),
-        );
-        assert_ne!(a.img.data, img.data);
-        let b = run_fx(
-            "ec.utility.colorprofileconverter",
-            &[("inputProfile", Value::Enum(3)), ("outputProfile", Value::Enum(1))],
-            a.img,
-            0.0,
-            EffectEnv::default(),
-        );
-        assert!((0..3).all(|k| (b.img.get(0, 0)[k] - img.get(0, 0)[k]).abs() < 1e-4));
-        // Same profile both sides: identity. Working space defaults to sRGB.
-        let c = run_fx(
-            "ec.utility.colorprofileconverter",
-            &[("inputProfile", Value::Enum(0)), ("outputProfile", Value::Enum(1))],
-            img.clone(),
-            0.0,
-            EffectEnv::default(),
-        );
-        assert_eq!(c.img.data, img.data);
-        // Perceptual pulls out-of-gamut colours inside: saturated Rec.2020 green into sRGB.
-        let g = Image::filled(1, 1, [0.0, 1.0, 0.0, 1.0]);
-        let rel = run_fx(
-            "ec.utility.colorprofileconverter",
-            &[("inputProfile", Value::Enum(3)), ("outputProfile", Value::Enum(1))],
-            g.clone(),
-            0.0,
-            EffectEnv::default(),
-        );
-        assert!(rel.img.get(0, 0)[0] < 0.0);
-        let per = run_fx(
-            "ec.utility.colorprofileconverter",
-            &[("inputProfile", Value::Enum(3)), ("outputProfile", Value::Enum(1)), ("intent", Value::Enum(0))],
-            g,
-            0.0,
-            EffectEnv::default(),
-        );
-        assert!(per.img.get(0, 0).iter().all(|v| *v >= -1e-6));
-    }
-
-    struct RefHost(Image);
-    impl EffectHost for RefHost {
-        fn layer(&self, _: u64, _: bool) -> Option<LayerPixels> {
-            None
-        }
-        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
-            None
-        }
-        fn self_at(&self, _: f64, _: usize) -> Option<Buf> {
-            Some(Buf { img: self.0.clone(), offset: [0.0; 2], scale: 1.0 })
-        }
-    }
-
-    #[test]
-    fn color_stabilizer_matches_the_reference_frame() {
-        let mk = |k: f32, o: f32| {
-            let mut img = Image::new(40, 40);
-            for y in 0..40 {
-                for x in 0..40 {
-                    let v = (x as f32 / 40.0) * k + o;
-                    img.set(x, y, [v, v * 0.9, v * 0.8, 1.0]);
-                }
-            }
-            img
-        };
-        let reference = mk(1.0, 0.0);
-        let flicker = mk(0.8, 0.1);
-        let host = RefHost(reference.clone());
-        let env = EffectEnv { host: Some(&host), ..Default::default() };
-        let pts = [("blackPoint", Value::Vec2([5.0, 20.0])), ("midPoint", Value::Vec2([20.0, 20.0])), ("whitePoint", Value::Vec2([35.0, 20.0]))];
-        let mut vals: Vec<(&str, Value)> = pts.to_vec();
-        vals.push(("stabilize", Value::Enum(1)));
-        vals.push(("sampleSize", num(1.0)));
-        let out = run_fx("ec.color.colorstabilizer", &vals, flicker.clone(), 0.0, env);
-        for x in [5i64, 20, 35] {
-            let (o, r) = (out.img.get(x, 20), reference.get(x, 20));
-            assert!((o[0] - r[0]).abs() < 0.01, "x {x}: {o:?} vs {r:?}");
-        }
-        // Deterministic, and a no-op without a host.
-        let again = run_fx("ec.color.colorstabilizer", &vals, flicker.clone(), 0.0, env);
-        assert_eq!(out.img.data, again.img.data);
-        let none = run_fx("ec.color.colorstabilizer", &vals, flicker.clone(), 0.0, EffectEnv::default());
-        assert_eq!(none.img.data, flicker.data);
-        // Brightness mode corrects an offset at the black point.
-        let lifted = mk(1.0, 0.1);
-        let mut vals2: Vec<(&str, Value)> = pts.to_vec();
-        vals2.push(("sampleSize", num(1.0)));
-        let b = run_fx("ec.color.colorstabilizer", &vals2, lifted, 0.0, env);
-        assert!((b.img.get(5, 20)[0] - reference.get(5, 20)[0]).abs() < 0.01);
-    }
-}
+mod tests;
diff --git a/crates/effects/src/ocio/cdl.rs b/crates/effects/src/ocio/cdl.rs
new file mode 100644
index 000000000..dba8c68fe
--- /dev/null
+++ b/crates/effects/src/ocio/cdl.rs
@@ -0,0 +1,115 @@
+use super::{ParamUi, slider};
+
+// ---------------------------------------------------------------- ASC CDL
+
+/// An ASC Colour Decision List correction.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct Cdl {
+    pub slope: [f64; 3],
+    pub offset: [f64; 3],
+    pub power: [f64; 3],
+    pub sat: f64,
+}
+
+impl Default for Cdl {
+    fn default() -> Self {
+        Cdl { slope: [1.0; 3], offset: [0.0; 3], power: [1.0; 3], sat: 1.0 }
+    }
+}
+
+const LUMA: [f64; 3] = [0.2126, 0.7152, 0.0722];
+
+impl Cdl {
+    /// Forward CDL. `clamp` = the v1.2 style (results clamped to 0..1 after SOP and saturation).
+    pub fn apply(&self, c: [f64; 3], clamp: bool) -> [f64; 3] {
+        let mut o = [0.0; 3];
+        for i in 0..3 {
+            let v = c[i] * self.slope[i] + self.offset[i];
+            o[i] = if clamp {
+                v.clamp(0.0, 1.0).powf(self.power[i])
+            } else if v >= 0.0 {
+                v.powf(self.power[i])
+            } else {
+                v
+            };
+        }
+        let l = o[0] * LUMA[0] + o[1] * LUMA[1] + o[2] * LUMA[2];
+        let o = o.map(|v| l + self.sat * (v - l));
+        if clamp { o.map(|v| v.clamp(0.0, 1.0)) } else { o }
+    }
+    /// Exact inverse of [`Cdl::apply`] (inside the clamped range).
+    pub fn invert(&self, c: [f64; 3], clamp: bool) -> [f64; 3] {
+        let c = if clamp { c.map(|v| v.clamp(0.0, 1.0)) } else { c };
+        let l = c[0] * LUMA[0] + c[1] * LUMA[1] + c[2] * LUMA[2];
+        let s = if self.sat.abs() < 1e-9 { 1e-9 } else { self.sat };
+        let o = c.map(|v| l + (v - l) / s);
+        let mut r = [0.0; 3];
+        for i in 0..3 {
+            let v = if clamp { o[i].clamp(0.0, 1.0) } else { o[i] };
+            let pw = self.power[i].max(1e-9);
+            let u = if v >= 0.0 { v.powf(1.0 / pw) } else { v };
+            let sl = if self.slope[i].abs() < 1e-9 { 1e-9 } else { self.slope[i] };
+            r[i] = (u - self.offset[i]) / sl;
+        }
+        if clamp { r.map(|v| v.clamp(0.0, 1.0)) } else { r }
+    }
+}
+
+fn tag<'a>(xml: &'a str, name: &str) -> Option<&'a str> {
+    let open = xml.find(&format!("<{name}"))?;
+    let gt = open + xml[open..].find('>')?;
+    if xml[..gt].ends_with('/') {
+        return Some("");
+    }
+    let close = xml[gt..].find(&format!("</{name}>"))? + gt;
+    Some(&xml[gt + 1..close])
+}
+
+fn nums3(s: &str) -> Option<[f64; 3]> {
+    let v: Vec<f64> = s.split_whitespace().filter_map(|t| t.parse().ok()).collect();
+    (v.len() >= 3).then(|| [v[0], v[1], v[2]])
+}
+
+fn parse_cc(block: &str) -> Cdl {
+    let mut c = Cdl::default();
+    if let Some(s) = tag(block, "Slope").and_then(nums3) {
+        c.slope = s;
+    }
+    if let Some(s) = tag(block, "Offset").and_then(nums3) {
+        c.offset = s;
+    }
+    if let Some(s) = tag(block, "Power").and_then(nums3) {
+        c.power = s;
+    }
+    if let Some(s) = tag(block, "Saturation").and_then(|t| t.trim().parse().ok()) {
+        c.sat = s;
+    }
+    c
+}
+
+/// Parse ASC CDL XML (`.cc`, `.ccc`, `.cdl`): every `<ColorCorrection>` with its `id`.
+pub fn parse_cdl_xml(xml: &str) -> Vec<(String, Cdl)> {
+    let mut out = vec![];
+    let mut rest = xml;
+    while let Some(i) = rest.find("<ColorCorrection") {
+        let after = &rest[i..];
+        let head_end = after.find('>').unwrap_or(after.len());
+        let head = &after[..head_end];
+        let id = head
+            .find("id=")
+            .and_then(|k| {
+                let q = head[k + 3..].chars().next()?;
+                let s = &head[k + 4..];
+                s.find(q).map(|e| s[..e].to_string())
+            })
+            .unwrap_or_default();
+        let end = after.find("</ColorCorrection>").map(|e| e + "</ColorCorrection>".len()).unwrap_or(after.len());
+        out.push((id, parse_cc(&after[..end])));
+        rest = &after[end..];
+    }
+    out
+}
+
+pub(super) fn sl(lo: f64, hi: f64, smin: f64, smax: f64) -> ParamUi {
+    slider(lo, hi, smin, smax, 3)
+}
diff --git a/crates/effects/src/ocio/effects.rs b/crates/effects/src/ocio/effects.rs
new file mode 100644
index 000000000..5df24096d
--- /dev/null
+++ b/crates/effects/src/ocio/effects.rs
@@ -0,0 +1,467 @@
+use super::cdl::Cdl;
+use super::lut::load_file;
+use super::space::{ACES_CCT, ACES_CG, ACES2065_1, D65, IDENTITY, P3, REC709, REC2020, SPACES, Space, Tf, Xform, matrix, sp, space_names};
+use super::{Buf, ColorSpace, EffectCtx, EffectSpec, IntoParallelRefMutIterator, ParallelIterator, Value, invert, mul, mul_vec, p, popup, unpremul};
+
+// ---------------------------------------------------------------- displays, views and looks
+
+/// Displays of the built-in config: (name, display primaries/white, encoding).
+pub const DISPLAYS: &[(&str, [[f64; 2]; 3], Tf)] =
+    &[("sRGB", REC709, Tf::Srgb), ("Rec.1886 Rec.709", REC709, Tf::Gamma(2.4)), ("Display P3", P3, Tf::Srgb), ("Rec.2100-PQ", REC2020, Tf::Pq)];
+
+pub const VIEWS: &[&str] = &["Standard", "Tone Mapped", "Raw"];
+
+/// Configuration popup: the built-in config, or a custom `.ocio` file (Config File: a path or
+/// the config's text; spaces chosen by name, see [`crate::ocio_config`]).
+pub const CONFIGS: &[&str] = &["Built-in (EffectCraft minimal)", "Custom (.ocio file)"];
+
+/// Built-in looks: CDLs applied in ACEScct.
+pub fn looks() -> Vec<(&'static str, Cdl)> {
+    let grey = 0.413_588_402_492_442_1; // ACEScct of 0.18
+    let c = |slope: [f64; 3], offset: [f64; 3], sat: f64| Cdl { slope, offset, power: [1.0; 3], sat };
+    vec![
+        ("Warm", c([1.04, 1.0, 0.94], [0.0; 3], 1.0)),
+        ("Cool", c([0.95, 1.0, 1.06], [0.0; 3], 1.0)),
+        ("High Contrast", c([1.25; 3], [grey * (1.0 - 1.25); 3], 1.0)),
+        ("Low Contrast", c([0.8; 3], [grey * (1.0 - 0.8); 3], 1.0)),
+        ("Desaturated", c([1.0; 3], [0.0; 3], 0.6)),
+        ("Vivid", c([1.0; 3], [0.0; 3], 1.3)),
+    ]
+}
+
+/// Extended Reinhard roll-off (white point 16): maps 0..∞ into 0..1, ≈ identity near 0.
+pub(super) fn tonemap(v: f64) -> f64 {
+    let w2 = 256.0;
+    if v <= 0.0 { v } else { v * (1.0 + v / w2) / (1.0 + v) }
+}
+
+pub(super) fn tonemap_inv(y: f64) -> f64 {
+    if y <= 0.0 {
+        return y;
+    }
+    // Solve v² / w² + v (1 − y) − y = 0.
+    let (a, b, c) = (1.0 / 256.0, 1.0 - y, -y);
+    (-b + (b * b - 4.0 * a * c).sqrt()) / (2.0 * a)
+}
+
+/// Display transform of an input-space colour (`inverse`: display code values → input space).
+pub fn display_xform(input: &Space, display: usize, view: usize, inverse: bool) -> impl Fn([f32; 3]) -> [f32; 3] + Sync {
+    let (_, prims, tf) = DISPLAYS[display.min(DISPLAYS.len() - 1)];
+    let disp = Space { name: "display", prims: Some((prims, D65)), tf: Tf::Linear, raw: false };
+    let raw = view == 2 || input.raw;
+    let m_in = Xform::new(&Space { tf: Tf::Linear, ..*input }, &disp);
+    let m_out = Xform::new(&disp, &Space { tf: Tf::Linear, ..*input });
+    let in_tf = input.tf;
+    move |c: [f32; 3]| {
+        if raw {
+            return c;
+        }
+        if !inverse {
+            let lin = c.map(|v| in_tf.decode(v as f64) as f32);
+            let d = m_in.apply(lin);
+            d.map(|v| {
+                let v = v as f64;
+                let v = if view == 1 { tonemap(v) } else { v };
+                tf.encode(v) as f32
+            })
+        } else {
+            let d = c.map(|v| {
+                let l = tf.decode(v as f64);
+                (if view == 1 { tonemap_inv(l) } else { l }) as f32
+            });
+            m_out.apply(d).map(|v| in_tf.encode(v as f64) as f32)
+        }
+    }
+}
+
+// ---------------------------------------------------------------- effects
+
+pub(super) fn spec(id: &'static str, name: &'static str, cat: &'static str, params: Vec<crate::ParamSpec>, render: crate::RenderFn) -> EffectSpec {
+    EffectSpec { id, name, category: cat, params, render, gpu: false, float: true }
+}
+
+pub(super) fn space_param(id: &'static str, name: &'static str, default: u32) -> crate::ParamSpec {
+    p(id, name, Value::Enum(default), popup(&space_names()))
+}
+
+pub(super) fn direction() -> crate::ParamSpec {
+    p("direction", "Direction", Value::Enum(0), popup(&["Forward", "Inverse"]))
+}
+
+fn map_px(b: &mut Buf, f: impl Fn([f32; 3]) -> [f32; 3] + Sync) {
+    b.img.data.par_iter_mut().for_each(|px| {
+        let (c, a) = unpremul(*px);
+        if a <= 0.0 {
+            return;
+        }
+        let o = f(c);
+        *px = [o[0] * a, o[1] * a, o[2] * a, a];
+    });
+}
+
+pub(super) fn space_at(i: u32) -> &'static Space {
+    &SPACES[(i as usize).min(SPACES.len() - 1)]
+}
+
+/// The effects that take Configuration ▸ Custom (a `.ocio` file).
+pub(crate) const CUSTOM_CONFIG_FX: [&str; 2] = ["ec.color.ociocolorspace", "ec.color.ociodisplay"];
+
+/// Effect `id`'s transform under Configuration ▸ Custom: the config's conversion from the source
+/// space to the destination space (Color Space Transform) or through a display's view (Display
+/// Transform), see [`crate::ocio_config`]. `Ok(None)` with the built-in configuration; an error
+/// (the pixels pass through) when the config can't be read or has no such colour space.
+pub(super) fn custom_xf(id: &str, pr: &crate::Params) -> Result<Option<crate::ocio_config::Xf>, String> {
+    use crate::ocio_config::Xf;
+    if !CUSTOM_CONFIG_FX.contains(&id) || pr.e("config") != 1 {
+        return Ok(None);
+    }
+    let cfg = crate::ocio_config::load_config(pr.s("configFile")).map_err(|e| format!("Can't read the OCIO config: {e}"))?;
+    // A space by its typed name, else by the built-in popup's name.
+    let space = |name: &str, popup: u32| {
+        let name = if name.trim().is_empty() { space_at(popup).name } else { name.trim() };
+        cfg.space(name).ok_or_else(|| format!("The OCIO config has no color space `{name}`"))
+    };
+    let a = space(pr.s("sourceName"), pr.e("source"))?;
+    let inverse = pr.e("direction") == 1;
+    if id == "ec.color.ociodisplay" {
+        let (dn, vn) = display_view_names(pr);
+        let xf = cfg.display_path(a, dn, vn);
+        return Ok(Some(if inverse { Xf::Inverse(Box::new(xf)) } else { xf }));
+    }
+    let z = space(pr.s("destinationName"), pr.e("destination"))?;
+    // Inverse: the conversion the other way (OCIO's inverse ColorSpaceTransform).
+    Ok(Some(if inverse { cfg.path(z, a) } else { cfg.path(a, z) }))
+}
+
+/// The display and view a Display Transform names: the typed names, else the popups'.
+fn display_view_names(pr: &crate::Params) -> (&str, &str) {
+    let display = DISPLAYS.get(pr.e("display") as usize).map_or("", |d| d.0);
+    let view = VIEWS.get(pr.e("view") as usize).copied().unwrap_or("");
+    let typed = |k: &str, popup| if pr.s(k).trim().is_empty() { popup } else { pr.s(k).trim() };
+    (typed("displayName", display), typed("viewName", view))
+}
+
+/// Effect Controls' warning for effect `id`: a custom OCIO configuration that can't be read, has
+/// no such colour space, display or view, or uses transforms EffectCraft can't apply (colours
+/// pass through those steps, #410). `None` when the effect renders as asked.
+pub fn warning(id: &str, pr: &crate::Params) -> Option<String> {
+    let xf = match custom_xf(id, pr) {
+        Ok(x) => x?,
+        Err(e) => return Some(format!("{e}: the colors pass through.")),
+    };
+    let mut notes = vec![];
+    if id == "ec.color.ociodisplay"
+        && let Ok(cfg) = crate::ocio_config::load_config(pr.s("configFile"))
+    {
+        let (dn, vn) = display_view_names(pr);
+        if let Some((d, v)) = cfg.view(dn, vn)
+            && (!d.eq_ignore_ascii_case(dn) || !v.name.eq_ignore_ascii_case(vn))
+        {
+            notes.push(format!("The OCIO config has no display `{dn}` with a view `{vn}`: showing {d} / {}.", v.name));
+        }
+    }
+    let missing = xf.unsupported_list();
+    if !missing.is_empty() {
+        notes.push(format!("Not supported, the colors pass through: {}.", missing.join(", ")));
+    }
+    (!notes.is_empty()).then(|| notes.join(" "))
+}
+
+/// Configuration ▸ Custom: render through the config's transform. `false` with the built-in
+/// configuration (the caller renders it).
+fn custom_render(id: &str, ctx: &EffectCtx, b: &mut Buf) -> bool {
+    match custom_xf(id, ctx.params) {
+        Ok(None) => false,
+        Ok(Some(xf)) => {
+            map_px(b, |c| xf.apply(c.map(|v| v as f64), false).map(|v| v as f32));
+            true
+        }
+        // A config that can't be read, or an unknown space: the pixels pass through.
+        Err(_) => true,
+    }
+}
+
+pub(super) fn ocio_cst(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    if custom_render("ec.color.ociocolorspace", ctx, &mut b) {
+        return b;
+    }
+    let (a, z) = (space_at(ctx.params.e("source")), space_at(ctx.params.e("destination")));
+    let (a, z) = if ctx.params.e("direction") == 1 { (z, a) } else { (a, z) };
+    if a.name == z.name {
+        return b;
+    }
+    let x = Xform::new(a, z);
+    map_px(&mut b, |c| x.apply(c));
+    b
+}
+
+pub(super) fn cdl_from_params(pr: &crate::Params) -> Cdl {
+    Cdl {
+        slope: [pr.f("slopeRed"), pr.f("slopeGreen"), pr.f("slopeBlue")],
+        offset: [pr.f("offsetRed"), pr.f("offsetGreen"), pr.f("offsetBlue")],
+        power: [pr.f("powerRed").max(0.0), pr.f("powerGreen").max(0.0), pr.f("powerBlue").max(0.0)],
+        sat: pr.f("saturation").max(0.0),
+    }
+}
+
+pub(super) fn ocio_cdl(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let cdl = cdl_from_params(ctx.params);
+    if cdl == Cdl::default() {
+        return b;
+    }
+    let clamp = ctx.params.e("style") == 0;
+    let inv = ctx.params.e("direction") == 1;
+    map_px(&mut b, |c| {
+        let c = c.map(|v| v as f64);
+        let o = if inv { cdl.invert(c, clamp) } else { cdl.apply(c, clamp) };
+        o.map(|v| v as f32)
+    });
+    b
+}
+
+pub(super) fn ocio_display(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    if custom_render("ec.color.ociodisplay", ctx, &mut b) {
+        return b;
+    }
+    let input = space_at(ctx.params.e("source"));
+    let f = display_xform(input, ctx.params.e("display") as usize, ctx.params.e("view") as usize, ctx.params.e("direction") == 1);
+    map_px(&mut b, f);
+    b
+}
+
+pub(super) fn ocio_file(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let Some(x) = load_file(ctx.params.s("file")) else { return b };
+    let interp = match ctx.params.e("interpolation") {
+        0 => 0,
+        1 => 1,
+        _ => 2,
+    };
+    let inv = ctx.params.e("direction") == 1;
+    let id = ctx.params.s("cccId").to_string();
+    map_px(&mut b, |c| x.apply(c, interp, inv, &id));
+    b
+}
+
+/// Parse a looks string: comma/space separated names, `-Name` = inverse.
+pub fn parse_looks(s: &str) -> Vec<(Cdl, bool)> {
+    let all = looks();
+    s.split([',', ':'])
+        .map(str::trim)
+        .filter(|t| !t.is_empty())
+        .filter_map(|t| {
+            let (inv, n) = match t.strip_prefix('-') {
+                Some(r) => (true, r.trim()),
+                None => (false, t.trim_start_matches('+').trim()),
+            };
+            all.iter().find(|(name, _)| name.eq_ignore_ascii_case(n)).map(|(_, c)| (*c, inv))
+        })
+        .collect()
+}
+
+pub(super) fn ocio_look(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let mut list = parse_looks(ctx.params.s("looks"));
+    let pick = ctx.params.e("look");
+    if pick > 0
+        && let Some((_, c)) = looks().get(pick as usize - 1)
+    {
+        list.insert(0, (*c, false));
+    }
+    if list.is_empty() {
+        return b;
+    }
+    let (src, dst) = (space_at(ctx.params.e("source")), space_at(ctx.params.e("destination")));
+    let inv = ctx.params.e("direction") == 1;
+    let cct = &ACES_CCT;
+    let (a, z) = if inv { (dst, src) } else { (src, dst) };
+    let to_p = Xform::new(a, cct);
+    let from_p = Xform::new(cct, z);
+    if inv {
+        list.reverse();
+    }
+    map_px(&mut b, |c| {
+        let mut v = to_p.apply(c).map(|x| x as f64);
+        for (cdl, li) in &list {
+            v = if *li != inv { cdl.invert(v, false) } else { cdl.apply(v, false) };
+        }
+        from_p.apply(v.map(|x| x as f32))
+    });
+    b
+}
+
+// ---- Color Profile Converter (Utility)
+
+pub const PROFILES: &[&str] = &["Project Working Space", "sRGB IEC61966-2.1", "HDTV (Rec. 709)", "Rec. 2020", "Display P3", "ACEScg", "ACES2065-1"];
+
+pub(super) fn profile(ctx: &EffectCtx, i: u32) -> (Space, bool) {
+    let ws = |cs: ColorSpace| match cs {
+        ColorSpace::Srgb => sp("sRGB", REC709, D65, Tf::Srgb),
+        ColorSpace::Rec709 => sp("Rec.709", REC709, D65, Tf::Gamma(2.4)),
+        ColorSpace::Rec2020 => sp("Rec.2020", REC2020, D65, Tf::Gamma(2.4)),
+        ColorSpace::DisplayP3 => sp("Display P3", P3, D65, Tf::Srgb),
+        ColorSpace::AcesCg => ACES_CG,
+        ColorSpace::Aces2065 => ACES2065_1,
+        // HDR encodings are output spaces, never a working space.
+        ColorSpace::Rec2100Pq | ColorSpace::Rec2100Hlg => sp("Rec.2020", REC2020, D65, Tf::Gamma(2.4)),
+    };
+    match i {
+        0 => (ws(ctx.env.working_space.unwrap_or(ColorSpace::Srgb)), ctx.env.working_linear),
+        1 => (ws(ColorSpace::Srgb), false),
+        2 => (ws(ColorSpace::Rec709), false),
+        3 => (ws(ColorSpace::Rec2020), false),
+        4 => (ws(ColorSpace::DisplayP3), false),
+        5 => (ACES_CG, true),
+        _ => (ACES2065_1, true),
+    }
+}
+
+/// Gamut compression for the perceptual intent: pull out-of-gamut (negative) colours toward
+/// their luminance just enough to bring every channel to ≥ 0, rolling off smoothly.
+fn compress_gamut(c: [f64; 3], luma: [f64; 3]) -> [f64; 3] {
+    let l = c[0] * luma[0] + c[1] * luma[1] + c[2] * luma[2];
+    if l <= 0.0 {
+        return c.map(|v| v.max(0.0));
+    }
+    let mn = c.iter().cloned().fold(f64::INFINITY, f64::min);
+    if mn >= 0.0 {
+        return c;
+    }
+    // Fraction of the way toward grey that reaches zero on the most negative channel.
+    let t = (l / (l - mn)).clamp(0.0, 1.0);
+    c.map(|v| l + (v - l) * t)
+}
+
+pub(super) fn profile_converter(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let (inp, in_lin_default) = profile(ctx, ctx.params.e("inputProfile"));
+    let (out, out_lin_default) = profile(ctx, ctx.params.e("outputProfile"));
+    let in_lin = ctx.params.b("linearizeInputProfile") || in_lin_default && ctx.params.e("inputProfile") == 0;
+    let out_lin = ctx.params.b("linearizeOutputProfile") || out_lin_default && ctx.params.e("outputProfile") == 0;
+    let intent = ctx.params.e("intent");
+    let dec = if in_lin { Tf::Linear } else { inp.tf };
+    let enc = if out_lin { Tf::Linear } else { out.tf };
+    // Absolute colorimetric keeps the source white (no adaptation); the others adapt.
+    let m = if intent == 3 { mul(&invert(&out.to_ref(false)), &inp.to_ref(false)) } else { matrix(&inp, &out) };
+    let identity = dec == enc && (0..3).all(|i| (0..3).all(|j| (m[i][j] - IDENTITY[i][j]).abs() < 1e-9));
+    if identity {
+        return b;
+    }
+    let out_luma = out.to_ref(true)[1];
+    map_px(&mut b, |c| {
+        let l = c.map(|v| dec.decode(v as f64));
+        let mut o = mul_vec(&m, l);
+        match intent {
+            0 => o = compress_gamut(o, out_luma),
+            2 => o = o.map(|v| v.max(0.0)),
+            _ => {}
+        }
+        o.map(|v| enc.encode(v) as f32)
+    });
+    b
+}
+
+// ---- Color Stabilizer
+
+/// Mean straight colour of a square (half-size `r` layer pixels) around layer point `pt`.
+fn sample_mean(b: &Buf, pt: [f64; 2], r: f64) -> [f64; 3] {
+    let (cx, cy) = b.to_px(pt);
+    let rr = (r * b.scale).max(0.5);
+    let (x0, x1) = ((cx - rr).floor().max(0.0) as i64, ((cx + rr).ceil() as i64).min(b.img.width as i64));
+    let (y0, y1) = ((cy - rr).floor().max(0.0) as i64, ((cy + rr).ceil() as i64).min(b.img.height as i64));
+    let mut acc = [0.0f64; 4];
+    for y in y0..y1 {
+        for x in x0..x1 {
+            let p = b.img.get(x, y);
+            for k in 0..4 {
+                acc[k] += p[k] as f64;
+            }
+        }
+    }
+    if acc[3] <= 1e-9 {
+        return [0.0; 3];
+    }
+    [acc[0] / acc[3], acc[1] / acc[3], acc[2] / acc[3]]
+}
+
+/// Monotone piecewise-quadratic curve through (0,0), three samples and (1,1) (linear between
+/// them is enough for a stabiliser and stays monotone).
+fn curve3(xs: [f64; 3], ys: [f64; 3], v: f64) -> f64 {
+    let mut pts = vec![(0.0, 0.0)];
+    let mut pairs: Vec<(f64, f64)> = xs.iter().cloned().zip(ys.iter().cloned()).collect();
+    pairs.sort_by(|a, b| a.0.total_cmp(&b.0));
+    for (x, y) in pairs {
+        if pts.last().is_some_and(|l| x > l.0 + 1e-4) && x < 1.0 - 1e-4 {
+            pts.push((x, y));
+        }
+    }
+    pts.push((1.0, 1.0));
+    let i = pts.partition_point(|p| p.0 < v).clamp(1, pts.len() - 1);
+    let (a, c) = (pts[i - 1], pts[i]);
+    a.1 + (c.1 - a.1) * (v - a.0) / (c.0 - a.0).max(1e-9)
+}
+
+/// Color Stabilizer's correction of buffer `b` as one piecewise-linear map per channel (points
+/// with increasing x; the end segments extend), the same maps `color_stabilizer` applies.
+/// `None` without a host or reference frame (the layer passes through). (The GPU effect.)
+pub fn color_stabilizer_maps(ctx: &EffectCtx, b: &Buf) -> Option<[Vec<(f64, f64)>; 3]> {
+    let reference = ctx.env.host?.self_at(ctx.params.f("referenceFrame"), ctx.env.effect_index)?;
+    let r = ctx.params.f("sampleSize").max(0.5);
+    let pts = [ctx.params.v2("blackPoint"), ctx.params.v2("midPoint"), ctx.params.v2("whitePoint")];
+    let cur = pts.map(|pt| sample_mean(b, pt, r));
+    let refv = pts.map(|pt| sample_mean(&reference, pt, r));
+    let mode = ctx.params.e("stabilize");
+    Some([0, 1, 2].map(|k| {
+        let offset = |c0: f64, r0: f64| vec![(0.0, r0 - c0), (1.0, 1.0 + r0 - c0)];
+        match mode {
+            0 => offset(cur[0][k], refv[0][k]),
+            1 => {
+                let (c0, c1, r0, r1) = (cur[0][k], cur[2][k], refv[0][k], refv[2][k]);
+                if (c1 - c0).abs() < 1e-6 {
+                    offset(c0, r0)
+                } else if c0 < c1 {
+                    vec![(c0, r0), (c1, r1)]
+                } else {
+                    vec![(c1, r1), (c0, r0)]
+                }
+            }
+            _ => {
+                let mut v = vec![(0.0, 0.0)];
+                let mut pairs: Vec<(f64, f64)> = (0..3).map(|i| (cur[i][k], refv[i][k])).collect();
+                pairs.sort_by(|a, b| a.0.total_cmp(&b.0));
+                for (x, y) in pairs {
+                    if v.last().is_some_and(|l| x > l.0 + 1e-4) && x < 1.0 - 1e-4 {
+                        v.push((x, y));
+                    }
+                }
+                v.push((1.0, 1.0));
+                v
+            }
+        }
+    }))
+}
+
+pub(super) fn color_stabilizer(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let Some(host) = ctx.env.host else { return b };
+    let Some(reference) = host.self_at(ctx.params.f("referenceFrame"), ctx.env.effect_index) else { return b };
+    let r = ctx.params.f("sampleSize").max(0.5);
+    let pts = [ctx.params.v2("blackPoint"), ctx.params.v2("midPoint"), ctx.params.v2("whitePoint")];
+    let cur = pts.map(|pt| sample_mean(&b, pt, r));
+    let refv = pts.map(|pt| sample_mean(&reference, pt, r));
+    let mode = ctx.params.e("stabilize");
+    map_px(&mut b, |c| {
+        [0, 1, 2].map(|k| {
+            let v = c[k] as f64;
+            let o = match mode {
+                // Brightness: one sample (black point) — offset each channel.
+                0 => v + refv[0][k] - cur[0][k],
+                // Levels: black and white samples — linear map per channel.
+                1 => {
+                    let (c0, c1, r0, r1) = (cur[0][k], cur[2][k], refv[0][k], refv[2][k]);
+                    if (c1 - c0).abs() < 1e-6 { v + r0 - c0 } else { r0 + (v - c0) * (r1 - r0) / (c1 - c0) }
+                }
+                // Curves: three samples — a curve through them per channel.
+                _ => curve3([cur[0][k], cur[1][k], cur[2][k]], [refv[0][k], refv[1][k], refv[2][k]], v),
+            };
+            o as f32
+        })
+    });
+    b
+}
diff --git a/crates/effects/src/ocio/lut.rs b/crates/effects/src/ocio/lut.rs
new file mode 100644
index 000000000..8a6481eb6
--- /dev/null
+++ b/crates/effects/src/ocio/lut.rs
@@ -0,0 +1,331 @@
+use super::cdl::{Cdl, parse_cdl_xml};
+use super::{Arc, HashMap, Lut, Mutex, OnceLock, parse_cube};
+
+// ---------------------------------------------------------------- LUT files
+
+/// A loaded transform file.
+#[derive(Clone, Debug)]
+pub enum FileXform {
+    /// A lattice/1D LUT with an optional per-channel piecewise-linear shaper (cineSpace pre-LUT).
+    Lut { lut: Lut, shaper: Option<[Vec<(f32, f32)>; 3]> },
+    /// CDL corrections by id (in file order).
+    Cdl(Vec<(String, Cdl)>),
+    /// A matrix with offset (Sony Imageworks `.spimtx`), as a MatrixTransform's.
+    Matrix { m: [f64; 16], offset: [f64; 4] },
+}
+
+/// Parse a Sony Imageworks `.spimtx` matrix: three rows of four numbers, three matrix columns
+/// and an offset in 16-bit code values (÷ 65535).
+pub fn parse_spimtx(text: &str) -> Option<FileXform> {
+    let v: Vec<f64> = text.split_whitespace().map(|t| t.parse().ok()).collect::<Option<_>>()?;
+    if v.len() != 12 || v.iter().any(|x| !x.is_finite()) {
+        return None;
+    }
+    let mut m = [0.0; 16];
+    let mut offset = [0.0; 4];
+    for (r, row) in v.as_chunks::<4>().0.iter().enumerate() {
+        m[r * 4..r * 4 + 3].copy_from_slice(&row[..3]);
+        offset[r] = row[3] / 65535.0;
+    }
+    m[15] = 1.0;
+    Some(FileXform::Matrix { m, offset })
+}
+
+/// Parse a Sony Imageworks `.spi1d` 1D LUT: `From <min> <max>`, `Length <n>`, `Components
+/// <1 | 3>`, then `{` the values `}`.
+pub fn parse_spi1d(text: &str) -> Option<Lut> {
+    let (mut from, mut len, mut comps) = ([0.0f32, 1.0], 0usize, 1usize);
+    let mut values: Vec<f32> = vec![];
+    let mut body = false;
+    for line in text.lines().map(str::trim).filter(|l| !l.is_empty()) {
+        if body {
+            if line.starts_with('}') {
+                break;
+            }
+            for t in line.split_whitespace() {
+                values.push(t.parse().ok()?);
+            }
+            continue;
+        }
+        let mut t = line.split_whitespace();
+        match t.next()? {
+            "{" => body = true,
+            "From" => from = [t.next()?.parse().ok()?, t.next()?.parse().ok()?],
+            "Length" => len = t.next()?.parse().ok()?,
+            "Components" => comps = t.next()?.parse().ok()?,
+            _ => {}
+        }
+    }
+    // A 1D table is interpolated by index, so cap it like the lattices (2²⁴ entries).
+    if !(2..=1 << 24).contains(&len)
+        || !matches!(comps, 1 | 3)
+        || values.len() != len.checked_mul(comps)?
+        || from[1] <= from[0]
+        || from.iter().any(|v| !v.is_finite())
+    {
+        return None;
+    }
+    let d1 = values.chunks_exact(comps).map(|c| if comps == 3 { [c[0], c[1], c[2]] } else { [c[0]; 3] }).collect();
+    Some(Lut { n1: len, d1, n3: 0, d3: vec![], dmin: [from[0]; 3], dmax: [from[1]; 3] })
+}
+
+/// Parse a Sony Imageworks `.spi3d` lattice: `SPILUT 1.0`, `3 3`, the sizes, then one
+/// `r g b  R G B` line per lattice point (indices, then the colour).
+pub fn parse_spi3d(text: &str) -> Option<Lut> {
+    let mut lines = text.lines().map(str::trim).filter(|l| !l.is_empty());
+    if !lines.next()?.starts_with("SPILUT") {
+        return None;
+    }
+    lines.next()?;
+    let size: Vec<usize> = lines.next()?.split_whitespace().map(|t| t.parse().ok()).collect::<Option<_>>()?;
+    let n = *size.first()?;
+    if size.len() != 3 || size.iter().any(|s| *s != n) || !(2..=129).contains(&n) {
+        return None;
+    }
+    let mut d3 = vec![[0.0f32; 3]; n * n * n];
+    let mut seen = 0usize;
+    for line in lines {
+        let v: Vec<&str> = line.split_whitespace().collect();
+        let [r, g, b, cr, cg, cb] = v.as_slice() else { return None };
+        let (r, g, b): (usize, usize, usize) = (r.parse().ok()?, g.parse().ok()?, b.parse().ok()?);
+        if r >= n || g >= n || b >= n {
+            return None;
+        }
+        // Our lattice is red fastest.
+        *d3.get_mut(r + g * n + b * n * n)? = [cr.parse().ok()?, cg.parse().ok()?, cb.parse().ok()?];
+        seen += 1;
+    }
+    (seen == n * n * n).then_some(Lut { n1: 0, d1: vec![], n3: n, d3, dmin: [0.0; 3], dmax: [1.0; 3] })
+}
+
+/// Parse an Autodesk `.3dl` lattice (integers, blue fastest; an optional input-mesh line).
+pub fn parse_3dl(text: &str) -> Option<Lut> {
+    let mut mesh: Option<Vec<f64>> = None;
+    let mut rows: Vec<[f64; 3]> = vec![];
+    let mut out_bits: Option<u32> = None;
+    for line in text.lines() {
+        let l = line.trim();
+        if l.is_empty() || l.starts_with('#') || l.starts_with('<') {
+            continue;
+        }
+        if l.starts_with(|c: char| c.is_ascii_alphabetic()) {
+            // "Mesh <in bits> <out bits>" (Lustre header); other keywords are ignored.
+            let t: Vec<&str> = l.split_whitespace().collect();
+            if t[0].eq_ignore_ascii_case("mesh") && t.len() >= 3 {
+                out_bits = t[2].parse().ok();
+            }
+            continue;
+        }
+        let v: Vec<f64> = l.split_whitespace().filter_map(|t| t.parse().ok()).collect();
+        if v.len() > 3 && mesh.is_none() && rows.is_empty() {
+            mesh = Some(v);
+        } else if v.len() == 3 {
+            rows.push([v[0], v[1], v[2]]);
+        } else {
+            return None;
+        }
+    }
+    let is_cube = |k: usize| {
+        let n = (k as f64).cbrt().round() as usize;
+        n * n * n == k
+    };
+    // A 3-entry input mesh (3³ lattice) looks like a data row: tell them apart by the count.
+    if mesh.is_none() && !is_cube(rows.len()) && rows.len() == 28 {
+        mesh = Some(rows.remove(0).to_vec());
+    }
+    let n = match &mesh {
+        Some(m) => m.len(),
+        None => (rows.len() as f64).cbrt().round() as usize,
+    };
+    if n < 2 || rows.len() != n * n * n {
+        return None;
+    }
+    let maxv = rows.iter().flat_map(|r| r.iter()).fold(0.0f64, |m, &v| m.max(v));
+    let out_max = match out_bits {
+        Some(b) if b > 0 && b < 32 => (1u64 << b) as f64 - 1.0,
+        _ => [255.0, 1023.0, 4095.0, 65535.0].into_iter().find(|&m| maxv <= m).unwrap_or(maxv.max(1.0)),
+    };
+    // .3dl rows: red slowest, blue fastest. Our lattice is red fastest.
+    let mut d3 = vec![[0.0f32; 3]; n * n * n];
+    for (k, r) in rows.iter().enumerate() {
+        let (ri, gi, bi) = (k / (n * n), (k / n) % n, k % n);
+        d3[ri + gi * n + bi * n * n] = r.map(|v| (v / out_max) as f32);
+    }
+    Some(Lut { n1: 0, d1: vec![], n3: n, d3, dmin: [0.0; 3], dmax: [1.0; 3] })
+}
+
+/// Parse a cineSpace `.csp` LUT (1D or 3D, with its three pre-LUT shapers).
+pub fn parse_csp(text: &str) -> Option<(Lut, [Vec<(f32, f32)>; 3])> {
+    let mut lines = text.lines().map(str::trim).filter(|l| !l.is_empty());
+    if !lines.next()?.starts_with("CSPLUTV100") {
+        return None;
+    }
+    let kind = lines.next()?;
+    let mut lines = lines.peekable();
+    if lines.peek().is_some_and(|l| l.starts_with("BEGIN METADATA")) {
+        for l in lines.by_ref() {
+            if l.starts_with("END METADATA") {
+                break;
+            }
+        }
+    }
+    let nums = |l: &str| -> Option<Vec<f32>> { l.split_whitespace().map(|t| t.parse().ok()).collect() };
+    let mut shaper: [Vec<(f32, f32)>; 3] = Default::default();
+    for ch in shaper.iter_mut() {
+        let n: usize = lines.next()?.parse().ok()?;
+        let ins = nums(lines.next()?)?;
+        let outs = nums(lines.next()?)?;
+        if ins.len() != n || outs.len() != n || n < 2 {
+            return None;
+        }
+        *ch = ins.into_iter().zip(outs).collect();
+    }
+    if kind.starts_with("3D") {
+        let sz = nums(lines.next()?)?;
+        if sz.len() != 3 || sz[0] != sz[1] || sz[1] != sz[2] {
+            return None;
+        }
+        let n = sz[0] as usize;
+        let mut d3 = Vec::with_capacity(n * n * n);
+        for _ in 0..n * n * n {
+            let v = nums(lines.next()?)?;
+            if v.len() != 3 {
+                return None;
+            }
+            d3.push([v[0], v[1], v[2]]);
+        }
+        (n >= 2).then_some((Lut { n1: 0, d1: vec![], n3: n, d3, dmin: [0.0; 3], dmax: [1.0; 3] }, shaper))
+    } else {
+        let n: usize = lines.next()?.parse().ok()?;
+        let mut d1 = Vec::with_capacity(n);
+        for _ in 0..n {
+            let v = nums(lines.next()?)?;
+            if v.len() != 3 {
+                return None;
+            }
+            d1.push([v[0], v[1], v[2]]);
+        }
+        (n >= 2).then_some((Lut { n1: n, d1, n3: 0, d3: vec![], dmin: [0.0; 3], dmax: [1.0; 3] }, shaper))
+    }
+}
+
+fn shape(curve: &[(f32, f32)], x: f32) -> f32 {
+    if curve.len() < 2 {
+        return x;
+    }
+    let i = curve.partition_point(|p| p.0 < x).clamp(1, curve.len() - 1);
+    let (a, b) = (curve[i - 1], curve[i]);
+    let t = ((x - a.0) / (b.0 - a.0).max(1e-12)).clamp(0.0, 1.0);
+    a.1 + (b.1 - a.1) * t
+}
+
+fn shape_inv(curve: &[(f32, f32)], y: f32) -> f32 {
+    let flipped: Vec<(f32, f32)> = curve.iter().map(|&(a, b)| (b, a)).collect();
+    shape(&flipped, y)
+}
+
+/// Parse transform text by its format (detected from `ext` or the content).
+pub fn parse_file(text: &str, ext: &str) -> Option<FileXform> {
+    let ext = ext.to_ascii_lowercase();
+    if ext == "cc" || ext == "ccc" || ext == "cdl" || text.contains("<ColorCorrection") {
+        let v = parse_cdl_xml(text);
+        return (!v.is_empty()).then_some(FileXform::Cdl(v));
+    }
+    if ext == "csp" || text.trim_start().starts_with("CSPLUTV100") {
+        return parse_csp(text).map(|(lut, s)| FileXform::Lut { lut, shaper: Some(s) });
+    }
+    if ext == "spimtx" {
+        return parse_spimtx(text);
+    }
+    if ext == "spi1d" || text.trim_start().starts_with("Version") {
+        return parse_spi1d(text).map(|lut| FileXform::Lut { lut, shaper: None });
+    }
+    if ext == "spi3d" || text.trim_start().starts_with("SPILUT") {
+        return parse_spi3d(text).map(|lut| FileXform::Lut { lut, shaper: None });
+    }
+    if ext == "cube" || text.contains("LUT_3D_SIZE") || text.contains("LUT_1D_SIZE") {
+        return parse_cube(text).map(|lut| FileXform::Lut { lut, shaper: None });
+    }
+    parse_3dl(text).map(|lut| FileXform::Lut { lut, shaper: None })
+}
+
+type FileCache = Mutex<HashMap<String, Option<Arc<FileXform>>>>;
+
+/// Load (and cache) a transform from a file path or inline content.
+pub fn load_file(src: &str) -> Option<Arc<FileXform>> {
+    let src_t = src.trim();
+    if src_t.is_empty() {
+        return None;
+    }
+    static CACHE: OnceLock<FileCache> = OnceLock::new();
+    let cache = CACHE.get_or_init(|| Mutex::new(HashMap::new()));
+    if let Ok(m) = cache.lock()
+        && let Some(v) = m.get(src)
+    {
+        return v.clone();
+    }
+    let inline = src.contains('\n');
+    let parsed = if inline {
+        parse_file(src, "")
+    } else {
+        let ext = std::path::Path::new(src_t).extension().and_then(std::ffi::OsStr::to_str).unwrap_or("");
+        std::fs::read_to_string(src_t).ok().and_then(|t| parse_file(&t, ext))
+    }
+    .map(Arc::new);
+    if let Ok(mut m) = cache.lock() {
+        m.insert(src.to_string(), parsed.clone());
+    }
+    parsed
+}
+
+impl FileXform {
+    pub fn apply(&self, c: [f32; 3], interp: u32, inverse: bool, ccc_id: &str) -> [f32; 3] {
+        match self {
+            FileXform::Cdl(list) => {
+                let cdl = list.iter().find(|(id, _)| !ccc_id.is_empty() && id == ccc_id).or(list.first()).map(|(_, c)| *c).unwrap_or_default();
+                let c64 = c.map(|v| v as f64);
+                let o = if inverse { cdl.invert(c64, true) } else { cdl.apply(c64, true) };
+                o.map(|v| v as f32)
+            }
+            FileXform::Matrix { m, offset } => crate::ocio_config::matrix_apply(m, offset, c.map(|v| v as f64), inverse).map(|v| v as f32),
+            FileXform::Lut { lut, shaper } => {
+                let fwd = |c: [f32; 3]| {
+                    let c = match shaper {
+                        Some(s) => [shape(&s[0], c[0]), shape(&s[1], c[1]), shape(&s[2], c[2])],
+                        None => c,
+                    };
+                    lut.apply_interp(c, interp)
+                };
+                if !inverse {
+                    return fwd(c);
+                }
+                if lut.n3 == 0 {
+                    // 1D: invert each channel exactly through the (monotone) tables.
+                    let mut x = c;
+                    if lut.n1 > 1 {
+                        x = [0, 1, 2].map(|i| {
+                            let curve: Vec<(f32, f32)> =
+                                (0..lut.n1).map(|k| (lut.d1[k][i], lut.dmin[i] + (lut.dmax[i] - lut.dmin[i]) * k as f32 / (lut.n1 - 1) as f32)).collect();
+                            shape(&curve, c[i])
+                        });
+                    }
+                    if let Some(s) = shaper {
+                        x = [shape_inv(&s[0], x[0]), shape_inv(&s[1], x[1]), shape_inv(&s[2], x[2])];
+                    }
+                    return x;
+                }
+                // 3D: damped fixed-point (Newton with an identity Jacobian) from the target.
+                let mut x = c;
+                for _ in 0..40 {
+                    let y = fwd(x);
+                    let e = [c[0] - y[0], c[1] - y[1], c[2] - y[2]];
+                    if e.iter().all(|v| v.abs() < 1e-6) {
+                        break;
+                    }
+                    x = [x[0] + e[0], x[1] + e[1], x[2] + e[2]];
+                }
+                x
+            }
+        }
+    }
+}
diff --git a/crates/effects/src/ocio/program.rs b/crates/effects/src/ocio/program.rs
new file mode 100644
index 000000000..a223dc7b4
--- /dev/null
+++ b/crates/effects/src/ocio/program.rs
@@ -0,0 +1,252 @@
+use super::cdl::Cdl;
+use super::effects::{DISPLAYS, cdl_from_params, custom_xf, looks, parse_looks, profile, space_at};
+use super::lut::{FileXform, load_file};
+use super::space::{ACES_CCT, D65, IDENTITY, Space, Tf, Xform, matrix};
+use super::{Arc, EffectCtx, Lut, invert, mul};
+
+// ---- Colour programs (the GPU compositor's colour-management kernels)
+
+/// One per-pixel step of a colour transform, in the order the CPU effect applies them (see
+/// [`color_program`]).
+#[derive(Clone, Debug)]
+pub enum ColorOp {
+    /// Transfer function, encoded → linear.
+    Decode(Tf),
+    /// Transfer function, linear → encoded.
+    Encode(Tf),
+    /// Linear-RGB matrix.
+    Matrix([[f32; 3]; 3]),
+    /// ASC CDL (forward or exact inverse; `clamp` = the v1.2 style).
+    Cdl { cdl: Cdl, clamp: bool, inverse: bool },
+    /// The Tone Mapped view's roll-off (or its inverse).
+    Tonemap { inverse: bool },
+    /// Color Profile Converter's perceptual gamut compression toward luminance `luma`.
+    Gamut([f64; 3]),
+    /// Negative channels to 0 (the saturation intent).
+    Max0,
+    /// A LUT (0 nearest, 1 trilinear, 2 tetrahedral) with an optional per-channel shaper, forward
+    /// or inverse (as `FileXform::apply`).
+    Lut { lut: Arc<Lut>, shaper: Option<Arc<[Vec<(f32, f32)>; 3]>>, interp: u32, inverse: bool },
+    /// `m × (c + pre) + post` (a custom config's MatrixTransform and RangeTransform).
+    Affine { m: [[f32; 3]; 3], pre: [f32; 3], post: [f32; 3] },
+    /// `max(c, 0) ^ p` per channel (ExponentTransform).
+    Pow([f32; 3]),
+    /// LogTransform / LogAffineTransform, forward or inverse (as `ocio_config::Xf::apply`).
+    LogAffine { base: f32, log_slope: [f32; 3], log_offset: [f32; 3], lin_slope: [f32; 3], lin_offset: [f32; 3], inverse: bool },
+    /// ExponentWithLinearTransform, forward (decode) or inverse (as
+    /// [`crate::ocio_config::moncurve`]).
+    MonCurve { gamma: [f32; 3], offset: [f32; 3], inverse: bool, mirror: bool },
+    /// Clamp each channel to `lo..=hi` (a clamping RangeTransform; ±`f32::MAX` = unbounded).
+    Clamp { lo: [f32; 3], hi: [f32; 3] },
+}
+
+/// The ops of a matrix-and-offset transform (MatrixTransform, `.spimtx`), forward or inverse
+/// (as [`crate::ocio_config::matrix_apply`]).
+fn matrix_ops(m: &[f64; 16], offset: &[f64; 4], inverse: bool, ops: &mut Vec<ColorOp>) {
+    if !inverse {
+        let m = [0, 1, 2].map(|r| [m[r * 4] as f32, m[r * 4 + 1] as f32, m[r * 4 + 2] as f32]);
+        ops.push(ColorOp::Affine { m, pre: [0.0; 3], post: [offset[0] as f32, offset[1] as f32, offset[2] as f32] });
+    } else if let Some(inv) = crate::ocio_config::mat3_inverse(m) {
+        let m = inv.map(|r| r.map(|v| v as f32));
+        ops.push(ColorOp::Affine { m, pre: [-offset[0] as f32, -offset[1] as f32, -offset[2] as f32], post: [0.0; 3] });
+    }
+}
+
+/// The ops of a LUT / CDL / matrix file transform (as [`FileXform::apply`]).
+fn file_ops(x: &FileXform, interp: u32, inverse: bool, ccc_id: &str, ops: &mut Vec<ColorOp>) {
+    match x {
+        FileXform::Cdl(list) => {
+            let cdl = list.iter().find(|(i, _)| !ccc_id.is_empty() && i == ccc_id).or(list.first()).map(|(_, c)| *c).unwrap_or_default();
+            ops.push(ColorOp::Cdl { cdl, clamp: true, inverse });
+        }
+        FileXform::Lut { lut, shaper } => {
+            ops.push(ColorOp::Lut { lut: Arc::new(lut.clone()), shaper: shaper.clone().map(Arc::new), interp, inverse });
+        }
+        FileXform::Matrix { m, offset } => matrix_ops(m, offset, inverse, ops),
+    }
+}
+
+/// The ops of a custom config's transform `x` (as `Xf::apply`).
+fn config_xf_ops(x: &crate::ocio_config::Xf, inverse: bool, ops: &mut Vec<ColorOp>) {
+    use crate::ocio_config::Xf;
+    let f3 = |v: &[f64; 3]| v.map(|x| x as f32);
+    match x {
+        Xf::Inverse(x) => config_xf_ops(x, !inverse, ops),
+        Xf::Matrix { m, offset } => matrix_ops(m, offset, inverse, ops),
+        Xf::File { xf: Some(x), interp, ccc, .. } => file_ops(x, *interp, inverse, ccc, ops),
+        Xf::ExponentLinear { gamma, offset, mirror } => ops.push(ColorOp::MonCurve { gamma: f3(gamma), offset: f3(offset), inverse, mirror: *mirror }),
+        // A BuiltinTransform's curve: forward decodes.
+        Xf::Curve(tf) => ops.push(if inverse { ColorOp::Encode(*tf) } else { ColorOp::Decode(*tf) }),
+        Xf::Named(_) => {}
+        Xf::File { xf: None, .. } | Xf::Unsupported(_) => {}
+        Xf::Exponent(e) => ops.push(ColorOp::Pow([0, 1, 2].map(|k| (if inverse { 1.0 / e[k].max(1e-9) } else { e[k] }) as f32))),
+        Xf::Log { base } => {
+            ops.push(ColorOp::LogAffine { base: *base as f32, log_slope: [1.0; 3], log_offset: [0.0; 3], lin_slope: [1.0; 3], lin_offset: [0.0; 3], inverse })
+        }
+        Xf::LogAffine { base, log_slope, log_offset, lin_slope, lin_offset } => ops.push(ColorOp::LogAffine {
+            base: *base as f32,
+            log_slope: f3(log_slope),
+            log_offset: f3(log_offset),
+            lin_slope: f3(lin_slope),
+            lin_offset: f3(lin_offset),
+            inverse,
+        }),
+        Xf::Cdl(cdl) => ops.push(ColorOp::Cdl { cdl: *cdl, clamp: true, inverse }),
+        Xf::Range(r) => {
+            let (k, off, lo, hi) = r.parts(inverse);
+            let k = k as f32;
+            ops.push(ColorOp::Affine { m: [[k, 0.0, 0.0], [0.0, k, 0.0], [0.0, 0.0, k]], pre: [0.0; 3], post: [off as f32; 3] });
+            if lo.is_finite() || hi.is_finite() {
+                let bound = |v: f64| (v as f32).clamp(-f32::MAX, f32::MAX);
+                ops.push(ColorOp::Clamp { lo: [bound(lo); 3], hi: [bound(hi); 3] });
+            }
+        }
+        Xf::Group(list) => {
+            if inverse {
+                list.iter().rev().for_each(|x| config_xf_ops(x, true, ops));
+            } else {
+                list.iter().for_each(|x| config_xf_ops(x, false, ops));
+            }
+        }
+    }
+}
+
+/// How a colour program meets premultiplied pixels.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Straight {
+    /// `unpremul` (colour 0 below alpha 1e-6); fully transparent pixels untouched (OCIO effects).
+    Unpremul,
+    /// Colour ÷ alpha; fully transparent pixels untouched (`Image::map_straight`, Apply Color LUT).
+    Divide,
+}
+
+fn xform_ops(x: &Xform, ops: &mut Vec<ColorOp>) {
+    if x.dec != Tf::Linear {
+        ops.push(ColorOp::Decode(x.dec));
+    }
+    if !x.ident {
+        ops.push(ColorOp::Matrix(x.m));
+    }
+    if x.enc != Tf::Linear {
+        ops.push(ColorOp::Encode(x.enc));
+    }
+}
+
+/// Effect `id`'s per-pixel transform as a list of [`ColorOp`]s that reproduces the CPU effect
+/// (empty = the layer passes through; custom OCIO configs compile their transforms too). `None`
+/// for another effect.
+pub fn color_program(id: &str, ctx: &EffectCtx) -> Option<(Vec<ColorOp>, Straight)> {
+    let pr = ctx.params;
+    let mut ops = vec![];
+    // Configuration ▸ Custom compiles the config's transforms (a config that can't be read, or
+    // names unknown spaces, passes the pixels through).
+    match custom_xf(id, pr) {
+        Ok(None) => {}
+        Ok(Some(xf)) => {
+            config_xf_ops(&xf, false, &mut ops);
+            return Some((ops, Straight::Unpremul));
+        }
+        Err(_) => return Some((ops, Straight::Unpremul)),
+    }
+    match id {
+        "ec.utility.applylut" => {
+            if let Some(lut) = crate::utility::load_lut(pr.s("lut")) {
+                ops.push(ColorOp::Lut { lut, shaper: None, interp: 2, inverse: false });
+            }
+            return Some((ops, Straight::Divide));
+        }
+        "ec.color.ociocolorspace" => {
+            let (a, z) = (space_at(pr.e("source")), space_at(pr.e("destination")));
+            let (a, z) = if pr.e("direction") == 1 { (z, a) } else { (a, z) };
+            if a.name != z.name {
+                xform_ops(&Xform::new(a, z), &mut ops);
+            }
+        }
+        "ec.color.ociocdl" => {
+            let cdl = cdl_from_params(pr);
+            if cdl != Cdl::default() {
+                ops.push(ColorOp::Cdl { cdl, clamp: pr.e("style") == 0, inverse: pr.e("direction") == 1 });
+            }
+        }
+        "ec.color.ociodisplay" => {
+            let input = space_at(pr.e("source"));
+            let (display, view, inverse) = (pr.e("display") as usize, pr.e("view") as usize, pr.e("direction") == 1);
+            let (_, prims, tf) = DISPLAYS[display.min(DISPLAYS.len() - 1)];
+            if view != 2 && !input.raw {
+                let disp = Space { name: "display", prims: Some((prims, D65)), tf: Tf::Linear, raw: false };
+                let lin = Space { tf: Tf::Linear, ..*input };
+                if !inverse {
+                    ops.push(ColorOp::Decode(input.tf));
+                    xform_ops(&Xform::new(&lin, &disp), &mut ops);
+                    if view == 1 {
+                        ops.push(ColorOp::Tonemap { inverse: false });
+                    }
+                    ops.push(ColorOp::Encode(tf));
+                } else {
+                    ops.push(ColorOp::Decode(tf));
+                    if view == 1 {
+                        ops.push(ColorOp::Tonemap { inverse: true });
+                    }
+                    xform_ops(&Xform::new(&disp, &lin), &mut ops);
+                    ops.push(ColorOp::Encode(input.tf));
+                }
+            }
+        }
+        "ec.color.ociofile" => {
+            if let Some(x) = load_file(pr.s("file")) {
+                let interp = match pr.e("interpolation") {
+                    0 => 0,
+                    1 => 1,
+                    _ => 2,
+                };
+                file_ops(&x, interp, pr.e("direction") == 1, pr.s("cccId"), &mut ops);
+            }
+        }
+        "ec.color.ociolook" => {
+            let mut list = parse_looks(pr.s("looks"));
+            let pick = pr.e("look");
+            if pick > 0
+                && let Some((_, c)) = looks().get(pick as usize - 1)
+            {
+                list.insert(0, (*c, false));
+            }
+            if !list.is_empty() {
+                let (src, dst) = (space_at(pr.e("source")), space_at(pr.e("destination")));
+                let inv = pr.e("direction") == 1;
+                let cct = &ACES_CCT;
+                let (a, z) = if inv { (dst, src) } else { (src, dst) };
+                if inv {
+                    list.reverse();
+                }
+                xform_ops(&Xform::new(a, cct), &mut ops);
+                for (cdl, li) in &list {
+                    ops.push(ColorOp::Cdl { cdl: *cdl, clamp: false, inverse: *li != inv });
+                }
+                xform_ops(&Xform::new(cct, z), &mut ops);
+            }
+        }
+        "ec.utility.colorprofileconverter" => {
+            let (inp, in_lin_default) = profile(ctx, pr.e("inputProfile"));
+            let (out, out_lin_default) = profile(ctx, pr.e("outputProfile"));
+            let in_lin = pr.b("linearizeInputProfile") || in_lin_default && pr.e("inputProfile") == 0;
+            let out_lin = pr.b("linearizeOutputProfile") || out_lin_default && pr.e("outputProfile") == 0;
+            let intent = pr.e("intent");
+            let dec = if in_lin { Tf::Linear } else { inp.tf };
+            let enc = if out_lin { Tf::Linear } else { out.tf };
+            let m = if intent == 3 { mul(&invert(&out.to_ref(false)), &inp.to_ref(false)) } else { matrix(&inp, &out) };
+            let identity = dec == enc && (0..3).all(|i| (0..3).all(|j| (m[i][j] - IDENTITY[i][j]).abs() < 1e-9));
+            if !identity {
+                ops.push(ColorOp::Decode(dec));
+                ops.push(ColorOp::Matrix(m.map(|r| r.map(|v| v as f32))));
+                match intent {
+                    0 => ops.push(ColorOp::Gamut(out.to_ref(true)[1])),
+                    2 => ops.push(ColorOp::Max0),
+                    _ => {}
+                }
+                ops.push(ColorOp::Encode(enc));
+            }
+        }
+        _ => return None,
+    }
+    Some((ops, Straight::Unpremul))
+}
diff --git a/crates/effects/src/ocio/registry.rs b/crates/effects/src/ocio/registry.rs
new file mode 100644
index 000000000..cd3bd02a7
--- /dev/null
+++ b/crates/effects/src/ocio/registry.rs
@@ -0,0 +1,129 @@
+use super::cdl::sl;
+use super::effects::{
+    CONFIGS, DISPLAYS, PROFILES, VIEWS, color_stabilizer, direction, looks, ocio_cdl, ocio_cst, ocio_display, ocio_file, ocio_look, profile_converter,
+    space_param, spec,
+};
+use super::space::SPACES;
+use super::{EffectSpec, ParamUi, Value, num, p, popup, slider};
+
+pub fn specs() -> Vec<EffectSpec> {
+    let cc = "Color Correction";
+    let srgb = SPACES.iter().position(|s| s.name == "sRGB").unwrap_or(0) as u32;
+    let lin709 = SPACES.iter().position(|s| s.name == "Linear Rec.709 (sRGB)").unwrap_or(0) as u32;
+    let acescg = SPACES.iter().position(|s| s.name == "ACEScg").unwrap_or(0) as u32;
+    let mut look_opts = vec!["None"];
+    look_opts.extend(looks().iter().map(|(n, _)| *n));
+    vec![
+        spec(
+            "ec.color.ociocdl",
+            "OCIO CDL Transform",
+            cc,
+            vec![
+                p("slopeRed", "Slope Red", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
+                p("slopeGreen", "Slope Green", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
+                p("slopeBlue", "Slope Blue", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
+                p("offsetRed", "Offset Red", num(0.0), sl(-100.0, 100.0, -1.0, 1.0)),
+                p("offsetGreen", "Offset Green", num(0.0), sl(-100.0, 100.0, -1.0, 1.0)),
+                p("offsetBlue", "Offset Blue", num(0.0), sl(-100.0, 100.0, -1.0, 1.0)),
+                p("powerRed", "Power Red", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
+                p("powerGreen", "Power Green", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
+                p("powerBlue", "Power Blue", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
+                p("saturation", "Saturation", num(1.0), sl(0.0, 100.0, 0.0, 4.0)),
+                p("style", "Style", Value::Enum(0), popup(&["ASC CDL v1.2", "No Clamp"])),
+                direction(),
+            ],
+            ocio_cdl,
+        ),
+        spec(
+            "ec.color.ociocolorspace",
+            "OCIO Color Space Transform",
+            cc,
+            vec![
+                p("config", "Configuration", Value::Enum(0), popup(CONFIGS)),
+                p("configFile", "Config File (.ocio)", Value::Str(String::new()), crate::file_ui(&["ocio"])),
+                space_param("source", "Source", lin709),
+                p("sourceName", "Source (config name)", Value::Str(String::new()), ParamUi::Text),
+                space_param("destination", "Destination", srgb),
+                p("destinationName", "Destination (config name)", Value::Str(String::new()), ParamUi::Text),
+                direction(),
+            ],
+            ocio_cst,
+        ),
+        spec(
+            "ec.color.ociodisplay",
+            "OCIO Display Transform",
+            cc,
+            vec![
+                p("config", "Configuration", Value::Enum(0), popup(CONFIGS)),
+                p("configFile", "Config File (.ocio)", Value::Str(String::new()), crate::file_ui(&["ocio"])),
+                space_param("source", "Input Color Space", lin709),
+                p("sourceName", "Source (config name)", Value::Str(String::new()), ParamUi::Text),
+                p("display", "Display Device", Value::Enum(0), popup(&DISPLAYS.iter().map(|d| d.0).collect::<Vec<_>>())),
+                p("displayName", "Display (config name)", Value::Str(String::new()), ParamUi::Text),
+                p("view", "View Transform", Value::Enum(0), popup(VIEWS)),
+                p("viewName", "View (config name)", Value::Str(String::new()), ParamUi::Text),
+                direction(),
+            ],
+            ocio_display,
+        ),
+        // `file`: a path to a .cube/.3dl/.csp/.cc/.ccc/.cdl file, or the file's text itself.
+        spec(
+            "ec.color.ociofile",
+            "OCIO File Transform",
+            cc,
+            vec![
+                p("file", "File", Value::Str(String::new()), crate::file_ui(&["cube", "3dl", "csp", "cc", "ccc", "cdl", "spi1d", "spi3d", "spimtx"])),
+                p("cccId", "CCC ID", Value::Str(String::new()), ParamUi::Text),
+                p("interpolation", "Interpolation", Value::Enum(3), popup(&["Nearest", "Linear", "Tetrahedral", "Best"])),
+                direction(),
+            ],
+            ocio_file,
+        ),
+        spec(
+            "ec.color.ociolook",
+            "OCIO Look Transform",
+            cc,
+            vec![
+                p("config", "Configuration", Value::Enum(0), popup(&["Built-in (EffectCraft minimal)"])),
+                space_param("source", "Source", acescg),
+                space_param("destination", "Destination", acescg),
+                p("look", "Look", Value::Enum(0), popup(&look_opts)),
+                p("looks", "Looks", Value::Str(String::new()), ParamUi::Text),
+                direction(),
+            ],
+            ocio_look,
+        ),
+        spec(
+            "ec.color.colorstabilizer",
+            "Color Stabilizer",
+            cc,
+            vec![
+                // The pivot frame (After Effects' Set Frame button stores it).
+                p("referenceFrame", "Reference Frame (s)", num(0.0), slider(-100000.0, 100000.0, 0.0, 60.0, 2)),
+                p("stabilize", "Stabilize", Value::Enum(0), popup(&["Brightness", "Levels", "Curves"])),
+                p("blackPoint", "Black Point", Value::Vec2([0.25, 0.75]), ParamUi::Point),
+                p("midPoint", "Mid Point", Value::Vec2([0.5, 0.5]), ParamUi::Point),
+                p("whitePoint", "White Point", Value::Vec2([0.75, 0.25]), ParamUi::Point),
+                p("sampleSize", "Sample Size", num(5.0), slider(1.0, 100.0, 1.0, 50.0, 0)),
+            ],
+            color_stabilizer,
+        ),
+        spec(
+            "ec.utility.colorprofileconverter",
+            "Color Profile Converter",
+            "Utility",
+            vec![
+                p("inputProfile", "Input Profile", Value::Enum(0), popup(PROFILES)),
+                p("linearizeInputProfile", "Linearize Input Profile", Value::Bool(false), ParamUi::Checkbox),
+                p("outputProfile", "Output Profile", Value::Enum(1), popup(PROFILES)),
+                p("linearizeOutputProfile", "Linearize Output Profile", Value::Bool(false), ParamUi::Checkbox),
+                p("intent", "Intent", Value::Enum(1), popup(&["Perceptual", "Relative Colorimetric", "Saturation", "Absolute Colorimetric"])),
+                // Our built-in profiles share a zero black point and none is scene-referred, so
+                // these two are kept for compatibility and do not change the result.
+                p("useBlackPointCompensation", "Use Black Point Compensation", Value::Bool(true), ParamUi::Checkbox),
+                p("sceneRefCompensation", "Scene-ref. Profile Compensation", Value::Enum(2), popup(&["On", "Off", "Use Project Setting"])),
+            ],
+            profile_converter,
+        ),
+    ]
+}
diff --git a/crates/effects/src/ocio/space.rs b/crates/effects/src/ocio/space.rs
new file mode 100644
index 000000000..1a1d8f69b
--- /dev/null
+++ b/crates/effects/src/ocio/space.rs
@@ -0,0 +1,214 @@
+use super::{invert, mul, mul_vec, rgb_to_xyz};
+
+pub(super) type M3 = [[f64; 3]; 3];
+
+pub(crate) const D65: [f64; 2] = [0.3127, 0.3290];
+
+const ACES_WHITE: [f64; 2] = [0.32168, 0.33767];
+
+const AP0: [[f64; 2]; 3] = [[0.7347, 0.2653], [0.0, 1.0], [0.0001, -0.0770]];
+
+const AP1: [[f64; 2]; 3] = [[0.713, 0.293], [0.165, 0.830], [0.128, 0.044]];
+
+pub(crate) const REC709: [[f64; 2]; 3] = [[0.640, 0.330], [0.300, 0.600], [0.150, 0.060]];
+
+pub(crate) const REC2020: [[f64; 2]; 3] = [[0.708, 0.292], [0.170, 0.797], [0.131, 0.046]];
+
+pub(crate) const P3: [[f64; 2]; 3] = [[0.680, 0.320], [0.265, 0.690], [0.150, 0.060]];
+
+pub(super) const IDENTITY: M3 = [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]];
+
+/// Transfer functions (encoded ↔ linear).
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum Tf {
+    Linear,
+    Srgb,
+    Gamma(f64),
+    AcesCct,
+    /// ACEScc (Academy S-2014-003), the pure-log grading encoding.
+    AcesCc,
+    /// SMPTE ST 2084 with 1.0 = 100 cd/m².
+    Pq,
+}
+
+/// ACEScc: the lowest code value (linear 0 and below) and the end of its toe (linear 2⁻¹⁵).
+const ACESCC_MIN: f64 = (-16.0 + 9.72) / 17.52;
+
+const ACESCC_TOE: f64 = (-15.0 + 9.72) / 17.52;
+
+impl Tf {
+    pub fn decode(self, v: f64) -> f64 {
+        match self {
+            Tf::Linear => v,
+            Tf::Srgb => {
+                let a = v.abs();
+                let l = if a <= 0.04045 { a / 12.92 } else { ((a + 0.055) / 1.055).powf(2.4) };
+                l.copysign(v)
+            }
+            Tf::Gamma(g) => v.abs().powf(g).copysign(v),
+            Tf::AcesCct => {
+                if v <= 0.155_251_141_552_511 {
+                    (v - 0.072_905_534_195_835_5) / 10.540_237_741_654_5
+                } else if v < (65504f64.log2() + 9.72) / 17.52 {
+                    2f64.powf(v * 17.52 - 9.72)
+                } else {
+                    65504.0
+                }
+            }
+            Tf::AcesCc => {
+                if v < ACESCC_TOE {
+                    (2f64.powf(v * 17.52 - 9.72) - 2f64.powi(-16)) * 2.0
+                } else if v < (65504f64.log2() + 9.72) / 17.52 {
+                    2f64.powf(v * 17.52 - 9.72)
+                } else {
+                    65504.0
+                }
+            }
+            Tf::Pq => {
+                let (m1, m2, c1, c2, c3) = pq_consts();
+                let e = v.max(0.0).powf(1.0 / m2);
+                let l = ((e - c1).max(0.0) / (c2 - c3 * e)).powf(1.0 / m1);
+                l * 100.0
+            }
+        }
+    }
+    pub fn encode(self, v: f64) -> f64 {
+        match self {
+            Tf::Linear => v,
+            Tf::Srgb => {
+                let a = v.abs();
+                let e = if a <= 0.003_130_8 { a * 12.92 } else { 1.055 * a.powf(1.0 / 2.4) - 0.055 };
+                e.copysign(v)
+            }
+            Tf::Gamma(g) => v.abs().powf(1.0 / g).copysign(v),
+            Tf::AcesCct => {
+                if v <= 0.007_812_5 {
+                    10.540_237_741_654_5 * v + 0.072_905_534_195_835_5
+                } else {
+                    (v.log2() + 9.72) / 17.52
+                }
+            }
+            Tf::AcesCc => {
+                if v <= 0.0 {
+                    ACESCC_MIN
+                } else if v < 2f64.powi(-15) {
+                    ((2f64.powi(-16) + v * 0.5).log2() + 9.72) / 17.52
+                } else {
+                    (v.log2() + 9.72) / 17.52
+                }
+            }
+            Tf::Pq => {
+                let (m1, m2, c1, c2, c3) = pq_consts();
+                let y = (v / 100.0).max(0.0).powf(m1);
+                ((c1 + c2 * y) / (1.0 + c3 * y)).powf(m2)
+            }
+        }
+    }
+}
+
+fn pq_consts() -> (f64, f64, f64, f64, f64) {
+    (2610.0 / 16384.0, 2523.0 / 4096.0 * 128.0, 3424.0 / 4096.0, 2413.0 / 4096.0 * 32.0, 2392.0 / 4096.0 * 32.0)
+}
+
+/// A colour space of the built-in config.
+#[derive(Clone, Copy, Debug)]
+pub struct Space {
+    pub name: &'static str,
+    /// Primaries and white (None = CIE XYZ itself).
+    pub prims: Option<([[f64; 2]; 3], [f64; 2])>,
+    pub tf: Tf,
+    /// Passes data through untouched.
+    pub raw: bool,
+}
+
+pub(crate) const fn sp(name: &'static str, prims: [[f64; 2]; 3], white: [f64; 2], tf: Tf) -> Space {
+    Space { name, prims: Some((prims, white)), tf, raw: false }
+}
+
+/// The built-in configuration's colour spaces, in popup order.
+pub(crate) const ACES2065_1: Space = sp("ACES2065-1", AP0, ACES_WHITE, Tf::Linear);
+
+pub(crate) const ACES_CG: Space = sp("ACEScg", AP1, ACES_WHITE, Tf::Linear);
+
+pub(super) const ACES_CCT: Space = sp("ACEScct", AP1, ACES_WHITE, Tf::AcesCct);
+
+pub const SPACES: &[Space] = &[
+    ACES2065_1,
+    ACES_CG,
+    ACES_CCT,
+    sp("Linear Rec.709 (sRGB)", REC709, D65, Tf::Linear),
+    sp("sRGB", REC709, D65, Tf::Srgb),
+    sp("Gamma 2.4 Rec.709", REC709, D65, Tf::Gamma(2.4)),
+    sp("Linear Rec.2020", REC2020, D65, Tf::Linear),
+    sp("Gamma 2.4 Rec.2020", REC2020, D65, Tf::Gamma(2.4)),
+    sp("Linear P3-D65", P3, D65, Tf::Linear),
+    sp("Display P3", P3, D65, Tf::Srgb),
+    Space { name: "CIE-XYZ-D65", prims: None, tf: Tf::Linear, raw: false },
+    Space { name: "Raw", prims: None, tf: Tf::Linear, raw: true },
+];
+
+pub fn space_names() -> Vec<&'static str> {
+    SPACES.iter().map(|s| s.name).collect()
+}
+
+#[cfg(test)]
+pub fn space_by_name(n: &str) -> Option<&'static Space> {
+    SPACES.iter().find(|s| s.name.eq_ignore_ascii_case(n))
+}
+
+/// Bradford chromatic adaptation from white `src` to white `dst` (xy).
+pub fn bradford(src: [f64; 2], dst: [f64; 2]) -> M3 {
+    if src == dst {
+        return IDENTITY;
+    }
+    const MB: M3 = [[0.8951, 0.2664, -0.1614], [-0.7502, 1.7135, 0.0367], [0.0389, -0.0685, 1.0296]];
+    let xyz = |c: [f64; 2]| [c[0] / c[1], 1.0, (1.0 - c[0] - c[1]) / c[1]];
+    let s = mul_vec(&MB, xyz(src));
+    let d = mul_vec(&MB, xyz(dst));
+    let diag = [[d[0] / s[0], 0.0, 0.0], [0.0, d[1] / s[1], 0.0], [0.0, 0.0, d[2] / s[2]]];
+    mul(&invert(&MB), &mul(&diag, &MB))
+}
+
+impl Space {
+    /// Linear RGB → XYZ D65 (Bradford-adapted when `adapt`, else the space's own white).
+    pub fn to_ref(self, adapt: bool) -> M3 {
+        match self.prims {
+            None => IDENTITY,
+            Some((p, w)) => {
+                let m = rgb_to_xyz(p, w);
+                if adapt { mul(&bradford(w, D65), &m) } else { m }
+            }
+        }
+    }
+}
+
+/// Linear-RGB matrix from space `a` to space `b`.
+pub fn matrix(a: &Space, b: &Space) -> M3 {
+    mul(&invert(&b.to_ref(true)), &a.to_ref(true))
+}
+
+/// A compiled colour-space conversion.
+#[derive(Clone, Copy, Debug)]
+pub struct Xform {
+    pub(super) dec: Tf,
+    pub(super) m: [[f32; 3]; 3],
+    pub(super) ident: bool,
+    pub(super) enc: Tf,
+}
+
+impl Xform {
+    pub fn new(a: &Space, b: &Space) -> Xform {
+        if a.raw || b.raw {
+            return Xform { dec: Tf::Linear, m: IDENTITY.map(|r| r.map(|v| v as f32)), ident: true, enc: Tf::Linear };
+        }
+        let m = matrix(a, b);
+        let ident = (0..3).all(|i| (0..3).all(|j| (m[i][j] - IDENTITY[i][j]).abs() < 1e-12));
+        Xform { dec: a.tf, m: m.map(|r| r.map(|v| v as f32)), ident, enc: b.tf }
+    }
+    #[inline]
+    pub fn apply(&self, c: [f32; 3]) -> [f32; 3] {
+        let l = c.map(|v| self.dec.decode(v as f64) as f32);
+        let l = if self.ident { l } else { [0, 1, 2].map(|i| self.m[i][0] * l[0] + self.m[i][1] * l[1] + self.m[i][2] * l[2]) };
+        l.map(|v| self.enc.encode(v as f64) as f32)
+    }
+}
diff --git a/crates/effects/src/ocio/tests.rs b/crates/effects/src/ocio/tests.rs
new file mode 100644
index 000000000..edbc6eff2
--- /dev/null
+++ b/crates/effects/src/ocio/tests.rs
@@ -0,0 +1,313 @@
+use super::*;
+use crate::{EffectEnv, EffectHost, Image, LayerPixels, run_fx};
+
+fn close(a: M3, b: M3, tol: f64) {
+    for i in 0..3 {
+        for j in 0..3 {
+            assert!((a[i][j] - b[i][j]).abs() < tol, "{a:?} vs {b:?}");
+        }
+    }
+}
+
+#[test]
+fn aces_matrices_match_published_values() {
+    let ap0 = space_by_name("ACES2065-1").unwrap();
+    let ap1 = space_by_name("ACEScg").unwrap();
+    // Academy S-2014-004 AP0 → AP1.
+    close(
+        matrix(ap0, ap1),
+        [
+            [1.451_439_316_1, -0.236_510_746_9, -0.214_928_569_3],
+            [-0.076_553_773_4, 1.176_229_699_8, -0.099_675_926_4],
+            [0.008_316_148_4, -0.006_032_449_8, 0.997_716_301_4],
+        ],
+        2e-4,
+    );
+    // ACEScg → linear Rec.709 with Bradford adaptation (published ACES config value).
+    let lin = space_by_name("Linear Rec.709 (sRGB)").unwrap();
+    close(matrix(ap1, lin), [[1.705_05, -0.621_79, -0.083_26], [-0.130_26, 1.140_80, -0.010_55], [-0.024_00, -0.128_97, 1.152_97]], 2e-3);
+    // White maps to white.
+    let w = mul_vec(&matrix(ap1, lin), [1.0, 1.0, 1.0]);
+    assert!(w.iter().all(|v| (v - 1.0).abs() < 1e-3), "{w:?}");
+}
+
+#[test]
+fn transfer_functions_round_trip() {
+    for tf in [Tf::Srgb, Tf::Gamma(2.4), Tf::AcesCct, Tf::Pq] {
+        for v in [0.0, 0.001, 0.18, 0.5, 1.0, 4.0] {
+            let r = tf.decode(tf.encode(v));
+            assert!((r - v).abs() < 1e-6 * v.max(1.0), "{tf:?} {v} {r}");
+        }
+    }
+    // ACEScct of 18 % grey (S-2016-001).
+    assert!((Tf::AcesCct.encode(0.18) - 0.413_588).abs() < 1e-5);
+    // PQ: 100 nits (1.0) encodes to ≈ 0.508.
+    assert!((Tf::Pq.encode(1.0) - 0.508).abs() < 1e-3);
+}
+
+#[test]
+fn color_space_transform_effect_round_trips() {
+    let img = Image::filled(4, 4, [0.2, 0.5, 0.7, 1.0]);
+    let srgb = SPACES.iter().position(|s| s.name == "sRGB").unwrap() as u32;
+    let cg = SPACES.iter().position(|s| s.name == "ACEScg").unwrap() as u32;
+    let a = run_fx("ec.color.ociocolorspace", &[("source", Value::Enum(srgb)), ("destination", Value::Enum(cg))], img.clone(), 0.0, EffectEnv::default());
+    assert_ne!(a.img.data, img.data);
+    let b = run_fx("ec.color.ociocolorspace", &[("source", Value::Enum(cg)), ("destination", Value::Enum(srgb))], a.img.clone(), 0.0, EffectEnv::default());
+    let c = run_fx(
+        "ec.color.ociocolorspace",
+        &[("source", Value::Enum(srgb)), ("destination", Value::Enum(cg)), ("direction", Value::Enum(1))],
+        a.img,
+        0.0,
+        EffectEnv::default(),
+    );
+    for (x, y) in b.img.data.iter().zip(&img.data).chain(c.img.data.iter().zip(&img.data)) {
+        assert!((0..4).all(|k| (x[k] - y[k]).abs() < 1e-4), "{x:?} {y:?}");
+    }
+}
+
+#[test]
+fn cdl_math() {
+    let cdl = Cdl { slope: [1.2, 1.0, 0.8], offset: [0.05, 0.0, -0.02], power: [1.1, 1.0, 0.9], sat: 0.8 };
+    let c = [0.3, 0.5, 0.7];
+    // Hand computation of the v1.2 formula.
+    let sop = [(0.3f64 * 1.2 + 0.05).powf(1.1), 0.5, (0.7f64 * 0.8 - 0.02).powf(0.9)];
+    let l = sop[0] * 0.2126 + sop[1] * 0.7152 + sop[2] * 0.0722;
+    let want = sop.map(|v| l + 0.8 * (v - l));
+    let got = cdl.apply(c, true);
+    for k in 0..3 {
+        assert!((got[k] - want[k]).abs() < 1e-12);
+    }
+    let back = cdl.invert(got, true);
+    for k in 0..3 {
+        assert!((back[k] - c[k]).abs() < 1e-9);
+    }
+    // v1.2 clamps, No Clamp keeps negatives.
+    let neg = Cdl { offset: [-0.5; 3], ..Cdl::default() };
+    assert_eq!(neg.apply([0.2; 3], true), [0.0; 3]);
+    assert!((neg.apply([0.2; 3], false)[0] + 0.3).abs() < 1e-12);
+    let img = Image::filled(2, 2, [0.3, 0.5, 0.7, 1.0]);
+    let out = run_fx("ec.color.ociocdl", &[("slopeRed", num(1.2)), ("offsetRed", num(0.05)), ("powerRed", num(1.1))], img, 0.0, EffectEnv::default());
+    let r = (0.3f64 * 1.2 + 0.05).powf(1.1);
+    assert!((out.img.get(0, 0)[0] as f64 - r).abs() < 1e-5);
+}
+
+fn identity_lattice(n: usize, f: impl Fn([f32; 3]) -> [f32; 3]) -> Vec<[f32; 3]> {
+    let mut v = vec![];
+    for b in 0..n {
+        for g in 0..n {
+            for r in 0..n {
+                let s = (n - 1) as f32;
+                v.push(f([r as f32 / s, g as f32 / s, b as f32 / s]));
+            }
+        }
+    }
+    v
+}
+
+/// Sony Imageworks `.spi1d`, `.spi3d` and `.spimtx` (Blender's configs use them, #410), and
+/// malformed ones rejected without panicking.
+#[test]
+fn spi_files_parse() {
+    let spi1d = "Version 1\nFrom 0.0 2.0\nLength 3\nComponents 1\n{\n0.0\n0.25\n1.0\n}\n";
+    let x = parse_file(spi1d, "spi1d").unwrap();
+    let o = x.apply([1.0, 0.5, 2.0], 1, false, "");
+    assert!((o[0] - 0.25).abs() < 1e-6 && (o[1] - 0.125).abs() < 1e-6 && (o[2] - 1.0).abs() < 1e-6, "{o:?}");
+    let back = x.apply(o, 1, true, "");
+    assert!((back[0] - 1.0).abs() < 1e-5 && (back[2] - 2.0).abs() < 1e-5, "{back:?}");
+    let three = parse_spi1d("Version 1\nFrom 0 1\nLength 2\nComponents 3\n{\n0 0 0\n1 0.5 2\n}\n").unwrap();
+    assert_eq!(three.d1, vec![[0.0; 3], [1.0, 0.5, 2.0]]);
+    let mut spi3d = String::from("SPILUT 1.0\n3 3\n2 2 2\n");
+    for (r, g, b) in (0..8).map(|i| (i & 1, (i >> 1) & 1, i >> 2)) {
+        spi3d += &format!("{r} {g} {b} {} {} {}\n", r as f32 * 0.5, g, b);
+    }
+    let x = parse_file(&spi3d, "spi3d").unwrap();
+    let o = x.apply([1.0, 0.5, 0.25], 1, false, "");
+    assert!((o[0] - 0.5).abs() < 1e-6 && (o[1] - 0.5).abs() < 1e-6 && (o[2] - 0.25).abs() < 1e-6, "{o:?}");
+    let m = parse_file("2 0 0 6553.5\n0 1 0 0\n0 0 1 0\n", "spimtx").unwrap();
+    let o = m.apply([0.25, 0.5, 1.0], 1, false, "");
+    assert!((o[0] - 0.6).abs() < 1e-6 && o[1] == 0.5 && o[2] == 1.0, "{o:?}");
+    assert!((m.apply(o, 1, true, "")[0] - 0.25).abs() < 1e-6);
+    for bad in [
+        "Version 1\nFrom 0 1\nLength 99999999999\nComponents 1\n{\n0\n}\n",
+        "Version 1\nFrom 1 0\nLength 2\nComponents 1\n{\n0\n1\n}\n",
+        "Version 1\nFrom 0 1\nLength 3\nComponents 1\n{\n0\n1\n}\n",
+        "Version 1\nFrom 0 1\nLength 2\nComponents 2\n{\n0 0\n1 1\n}\n",
+    ] {
+        assert!(parse_spi1d(bad).is_none(), "{bad}");
+    }
+    assert!(parse_spi3d("SPILUT 1.0\n3 3\n4000 4000 4000\n").is_none());
+    assert!(parse_spi3d("SPILUT 1.0\n3 3\n2 2 2\n9 0 0 1 1 1\n").is_none());
+    assert!(parse_spi3d("SPILUT 1.0\n3 3\n2 2 2\n0 0 0 1 1 1\n").is_none(), "incomplete lattice");
+    assert!(parse_spimtx("1 0 0\n0 1 0\n").is_none());
+    assert!(parse_spimtx("NaN 0 0 0 0 1 0 0 0 0 1 0").is_none());
+}
+
+#[test]
+fn lut_files_parse_and_interpolate() {
+    // .cube with a non-linear lattice: trilinear between lattice points.
+    let f = |c: [f32; 3]| [c[0] * c[0], c[1], 1.0 - c[2]];
+    let mut cube = String::from("LUT_3D_SIZE 3\n");
+    for r in identity_lattice(3, f) {
+        cube += &format!("{} {} {}\n", r[0], r[1], r[2]);
+    }
+    let Some(FileXform::Lut { lut, .. }) = parse_file(&cube, "cube") else { panic!() };
+    // Trilinear between 0.5 (0.25) and 1.0 (1.0) at 0.75 → 0.625.
+    let o = lut.apply_interp([0.75, 0.3, 0.2], 1);
+    assert!((o[0] - 0.625).abs() < 1e-6 && (o[1] - 0.3).abs() < 1e-6 && (o[2] - 0.8).abs() < 1e-6, "{o:?}");
+    // Nearest snaps.
+    assert_eq!(lut.apply_interp([0.74, 0.0, 0.0], 0)[0], 0.25);
+    // .3dl (blue fastest, 10-bit integers, mesh line).
+    let mut tdl = String::from("0 511 1023\n");
+    for r in 0..3 {
+        for g in 0..3 {
+            for b in 0..3 {
+                let v = [r, g, b].map(|i| i as f64 * 511.5);
+                tdl += &format!("{} {} {}\n", v[0].round(), v[1].round(), (1023.0 - v[2]).round());
+            }
+        }
+    }
+    let Some(FileXform::Lut { lut, .. }) = parse_file(&tdl, "3dl") else { panic!() };
+    let o = lut.apply_interp([0.25, 0.5, 0.25], 1);
+    assert!((o[0] - 0.25).abs() < 2e-3 && (o[1] - 0.5).abs() < 2e-3 && (o[2] - 0.75).abs() < 2e-3, "{o:?}");
+    // .csp with a squaring pre-LUT on red and an identity 2³ lattice.
+    let mut csp = String::from("CSPLUTV100\n3D\n\n3\n0 0.5 1\n0 0.25 1\n2\n0 1\n0 1\n2\n0 1\n0 1\n\n2 2 2\n");
+    for r in identity_lattice(2, |c| c) {
+        csp += &format!("{} {} {}\n", r[0], r[1], r[2]);
+    }
+    let x = parse_file(&csp, "csp").unwrap();
+    let o = x.apply([0.5, 0.4, 0.6], 2, false, "");
+    assert!((o[0] - 0.25).abs() < 1e-6 && (o[1] - 0.4).abs() < 1e-6, "{o:?}");
+    let inv = x.apply(o, 2, true, "");
+    assert!((inv[0] - 0.5).abs() < 1e-4, "{inv:?}");
+    // CDL collection: pick by id.
+    let ccc = r#"<ColorCorrectionCollection><ColorCorrection id="a"><SOPNode><Slope>2 2 2</Slope><Offset>0 0 0</Offset><Power>1 1 1</Power></SOPNode></ColorCorrection>
+            <ColorCorrection id='b'><SOPNode><Slope>0.5 0.5 0.5</Slope></SOPNode><SatNode><Saturation>1</Saturation></SatNode></ColorCorrection></ColorCorrectionCollection>"#;
+    let x = parse_file(ccc, "ccc").unwrap();
+    assert!((x.apply([0.4; 3], 2, false, "b")[0] - 0.2).abs() < 1e-6);
+    assert!((x.apply([0.4; 3], 2, false, "a")[0] - 0.8).abs() < 1e-6);
+    assert!((x.apply([0.4; 3], 2, false, "")[0] - 0.8).abs() < 1e-6);
+    // Effect with inline content; inverse of a 3D lattice.
+    let img = Image::filled(2, 2, [0.6, 0.3, 0.2, 1.0]);
+    let out = run_fx("ec.color.ociofile", &[("file", Value::Str(cube.clone()))], img.clone(), 0.0, EffectEnv::default());
+    let back = run_fx("ec.color.ociofile", &[("file", Value::Str(cube)), ("direction", Value::Enum(1))], out.img, 0.0, EffectEnv::default());
+    assert!((back.img.get(0, 0)[0] - 0.6).abs() < 1e-3, "{:?}", back.img.get(0, 0));
+    assert!(parse_file("garbage", "3dl").is_none());
+}
+
+#[test]
+fn display_and_look_transforms() {
+    // Linear 0.18 through the sRGB display / Standard view = sRGB encoding of 0.18.
+    let img = Image::filled(2, 2, [0.18, 0.18, 0.18, 1.0]);
+    let out = run_fx("ec.color.ociodisplay", &[], img.clone(), 0.0, EffectEnv::default());
+    assert!((out.img.get(0, 0)[0] as f64 - Tf::Srgb.encode(0.18)).abs() < 1e-5);
+    let back = run_fx("ec.color.ociodisplay", &[("direction", Value::Enum(1))], out.img, 0.0, EffectEnv::default());
+    assert!((back.img.get(0, 0)[0] - 0.18).abs() < 1e-5);
+    // Tone mapped view keeps highlights below 1.
+    let hot = Image::filled(1, 1, [8.0, 8.0, 8.0, 1.0]);
+    let tm = run_fx("ec.color.ociodisplay", &[("view", Value::Enum(1))], hot, 0.0, EffectEnv::default());
+    assert!(tm.img.get(0, 0)[0] < 1.0);
+    assert!((tonemap_inv(tonemap(3.0)) - 3.0).abs() < 1e-9);
+    // Looks: Warm raises red over blue; its inverse undoes it.
+    let grey = Image::filled(1, 1, [0.18, 0.18, 0.18, 1.0]);
+    let w = run_fx("ec.color.ociolook", &[("looks", Value::Str("Warm".into()))], grey.clone(), 0.0, EffectEnv::default());
+    let px = w.img.get(0, 0);
+    assert!(px[0] > px[2]);
+    let u = run_fx("ec.color.ociolook", &[("looks", Value::Str("-Warm".into()))], w.img, 0.0, EffectEnv::default());
+    assert!((u.img.get(0, 0)[0] - 0.18).abs() < 1e-4 && (u.img.get(0, 0)[2] - 0.18).abs() < 1e-4);
+    assert_eq!(parse_looks("Warm, -Cool, nope").len(), 2);
+}
+
+#[test]
+fn profile_converter_converts_and_round_trips() {
+    let img = Image::filled(2, 2, [0.8, 0.4, 0.1, 1.0]);
+    // sRGB → Rec. 2020 (relative), then back.
+    let a = run_fx(
+        "ec.utility.colorprofileconverter",
+        &[("inputProfile", Value::Enum(1)), ("outputProfile", Value::Enum(3))],
+        img.clone(),
+        0.0,
+        EffectEnv::default(),
+    );
+    assert_ne!(a.img.data, img.data);
+    let b =
+        run_fx("ec.utility.colorprofileconverter", &[("inputProfile", Value::Enum(3)), ("outputProfile", Value::Enum(1))], a.img, 0.0, EffectEnv::default());
+    assert!((0..3).all(|k| (b.img.get(0, 0)[k] - img.get(0, 0)[k]).abs() < 1e-4));
+    // Same profile both sides: identity. Working space defaults to sRGB.
+    let c = run_fx(
+        "ec.utility.colorprofileconverter",
+        &[("inputProfile", Value::Enum(0)), ("outputProfile", Value::Enum(1))],
+        img.clone(),
+        0.0,
+        EffectEnv::default(),
+    );
+    assert_eq!(c.img.data, img.data);
+    // Perceptual pulls out-of-gamut colours inside: saturated Rec.2020 green into sRGB.
+    let g = Image::filled(1, 1, [0.0, 1.0, 0.0, 1.0]);
+    let rel = run_fx(
+        "ec.utility.colorprofileconverter",
+        &[("inputProfile", Value::Enum(3)), ("outputProfile", Value::Enum(1))],
+        g.clone(),
+        0.0,
+        EffectEnv::default(),
+    );
+    assert!(rel.img.get(0, 0)[0] < 0.0);
+    let per = run_fx(
+        "ec.utility.colorprofileconverter",
+        &[("inputProfile", Value::Enum(3)), ("outputProfile", Value::Enum(1)), ("intent", Value::Enum(0))],
+        g,
+        0.0,
+        EffectEnv::default(),
+    );
+    assert!(per.img.get(0, 0).iter().all(|v| *v >= -1e-6));
+}
+
+struct RefHost(Image);
+impl EffectHost for RefHost {
+    fn layer(&self, _: u64, _: bool) -> Option<LayerPixels> {
+        None
+    }
+    fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+        None
+    }
+    fn self_at(&self, _: f64, _: usize) -> Option<Buf> {
+        Some(Buf { img: self.0.clone(), offset: [0.0; 2], scale: 1.0 })
+    }
+}
+
+#[test]
+fn color_stabilizer_matches_the_reference_frame() {
+    let mk = |k: f32, o: f32| {
+        let mut img = Image::new(40, 40);
+        for y in 0..40 {
+            for x in 0..40 {
+                let v = (x as f32 / 40.0) * k + o;
+                img.set(x, y, [v, v * 0.9, v * 0.8, 1.0]);
+            }
+        }
+        img
+    };
+    let reference = mk(1.0, 0.0);
+    let flicker = mk(0.8, 0.1);
+    let host = RefHost(reference.clone());
+    let env = EffectEnv { host: Some(&host), ..Default::default() };
+    let pts = [("blackPoint", Value::Vec2([5.0, 20.0])), ("midPoint", Value::Vec2([20.0, 20.0])), ("whitePoint", Value::Vec2([35.0, 20.0]))];
+    let mut vals: Vec<(&str, Value)> = pts.to_vec();
+    vals.push(("stabilize", Value::Enum(1)));
+    vals.push(("sampleSize", num(1.0)));
+    let out = run_fx("ec.color.colorstabilizer", &vals, flicker.clone(), 0.0, env);
+    for x in [5i64, 20, 35] {
+        let (o, r) = (out.img.get(x, 20), reference.get(x, 20));
+        assert!((o[0] - r[0]).abs() < 0.01, "x {x}: {o:?} vs {r:?}");
+    }
+    // Deterministic, and a no-op without a host.
+    let again = run_fx("ec.color.colorstabilizer", &vals, flicker.clone(), 0.0, env);
+    assert_eq!(out.img.data, again.img.data);
+    let none = run_fx("ec.color.colorstabilizer", &vals, flicker.clone(), 0.0, EffectEnv::default());
+    assert_eq!(none.img.data, flicker.data);
+    // Brightness mode corrects an offset at the black point.
+    let lifted = mk(1.0, 0.1);
+    let mut vals2: Vec<(&str, Value)> = pts.to_vec();
+    vals2.push(("sampleSize", num(1.0)));
+    let b = run_fx("ec.color.colorstabilizer", &vals2, lifted, 0.0, env);
+    assert!((b.img.get(5, 20)[0] - reference.get(5, 20)[0]).abs() < 0.01);
+}
diff --git a/crates/effects/src/ocio_config.rs b/crates/effects/src/ocio_config.rs
index 41c74b4e4..af860c2fc 100644
--- a/crates/effects/src/ocio_config.rs
+++ b/crates/effects/src/ocio_config.rs
@@ -1331,401 +1331,4 @@ pub fn load_config(src: &str) -> Result<Arc<Config>, String> {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    const CONFIG: &str = r#"
-ocio_profile_version: 2
-
-name: Test Config   # a comment
-search_path: "luts:other"
-roles:
-  scene_linear: lin
-  color_timing: "log2"
-
-displays:
-  sRGB:
-    - !<View> {name: Standard, colorspace: gamma22}
-    - !<View> {name: Raw, colorspace: raw}
-
-colorspaces:
-  - !<ColorSpace>
-    name: lin
-    family: ""
-    description: |
-      The reference.
-      Linear.
-    isdata: false
-
-  - !<ColorSpace>
-    name: gamma22
-    aliases: [g22, "gamma 2.2"]
-    to_scene_reference: !<ExponentTransform> {value: [2.2, 2.2, 2.2, 1]}
-
-  - !<ColorSpace>
-    name: half
-    from_reference: !<MatrixTransform> {matrix: [0.5, 0, 0, 0,
-                                                0, 0.5, 0, 0,
-                                                0, 0, 0.5, 0,
-                                                0, 0, 0, 1], offset: [0.1, 0.1, 0.1, 0]}
-
-  - !<ColorSpace>
-    name: log2
-    from_reference: !<GroupTransform>
-      children:
-        - !<MatrixTransform> {matrix: [2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 1]}
-        - !<LogTransform> {base: 2}
-
-  - !<ColorSpace>
-    name: affine
-    to_reference: !<LogAffineTransform> {base: 10, logSideSlope: 0.5, logSideOffset: 0.2, linSideSlope: 2, linSideOffset: 0.01, direction: inverse}
-
-  - !<ColorSpace>
-    name: lut
-    to_reference: !<FileTransform> {src: double.cube, interpolation: linear}
-
-  - !<ColorSpace>
-    name: raw
-    isdata: true
-
-  - !<ColorSpace>
-    name: weird
-    to_reference: !<ExposureContrastTransform> {exposure: 1}
-"#;
-
-    fn close(a: [f64; 3], b: [f64; 3], tol: f64) -> bool {
-        (0..3).all(|i| (a[i] - b[i]).abs() < tol)
-    }
-
-    fn temp_dir(name: &str) -> PathBuf {
-        let dir = std::env::temp_dir().join(format!("ec-ocio-{name}-{}", std::process::id()));
-        std::fs::create_dir_all(dir.join("luts")).unwrap();
-        dir
-    }
-
-    #[test]
-    fn yaml_subset() {
-        let y = parse_yaml("a: 1\nb:\n  - x\n  - {k: [1, 2], s: 'q: r'}\nc: !<T> {v: 3}\nd:\n- 4\n- 5\n");
-        assert_eq!(y.get("a").and_then(Yaml::str), Some("1"));
-        assert_eq!(y.get("b").unwrap().seq().len(), 2);
-        assert_eq!(y.get("b").unwrap().seq()[1].get("k").unwrap().nums(), vec![1.0, 2.0]);
-        assert_eq!(y.get("b").unwrap().seq()[1].get("s").and_then(Yaml::str), Some("q: r"));
-        assert_eq!(y.get("c").unwrap().tag(), Some("T"));
-        assert_eq!(y.get("c").unwrap().get("v").and_then(Yaml::str), Some("3"));
-        assert_eq!(y.get("d").unwrap().seq().len(), 2, "a sequence at the key's indent");
-    }
-
-    /// Hostile nesting (flow brackets and block indentation) is cut off instead of exhausting
-    /// the stack.
-    #[test]
-    fn yaml_nesting_is_bounded() {
-        let flow = format!("a: {}\nb: 1\n", "[".repeat(200_000));
-        assert!(matches!(parse_yaml(&flow), Yaml::Map(_)));
-        let block: String = (0..2_000).map(|i| format!("{}k{i}:\n", " ".repeat(i))).collect();
-        assert!(matches!(parse_yaml(&block), Yaml::Map(_)));
-        let dashes: String = (0..2_000).map(|i| format!("{}- x{i}:\n", " ".repeat(2 * i))).collect();
-        let _ = parse_yaml(&dashes);
-        assert!(Config::parse(&flow, Path::new(".")).is_err());
-    }
-
-    #[test]
-    fn parses_spaces_roles_displays_and_converts() {
-        let dir = temp_dir("basic");
-        // A 1D LUT that doubles (0..1 → 0..2).
-        std::fs::write(dir.join("luts/double.cube"), "LUT_1D_SIZE 2\nDOMAIN_MIN 0 0 0\nDOMAIN_MAX 1 1 1\n0 0 0\n2 2 2\n").unwrap();
-        let c = Config::parse(CONFIG, &dir).unwrap();
-        assert_eq!(c.name, "Test Config");
-        assert_eq!(c.search_path, vec!["luts", "other"]);
-        assert_eq!(c.space_names(), vec!["lin", "gamma22", "half", "log2", "affine", "lut", "raw", "weird"]);
-        // Roles and aliases resolve.
-        assert_eq!(c.space("scene_linear").unwrap().name, "lin");
-        assert_eq!(c.space("G22").unwrap().name, "gamma22");
-        assert_eq!(c.space("gamma 2.2").unwrap().name, "gamma22");
-        assert_eq!(c.view("sRGB", "Standard").unwrap().1.colorspace, "gamma22");
-        let sp = |n: &str| c.space(n).unwrap();
-        // gamma22 → lin: decode with the exponent.
-        let g = c.convert(sp("gamma22"), sp("lin"), [0.5, 0.25, 1.0]);
-        assert!(close(g, [0.5f64.powf(2.2), 0.25f64.powf(2.2), 1.0], 1e-9), "{g:?}");
-        // lin → gamma22: the inverse (only to_reference given).
-        let back = c.convert(sp("lin"), sp("gamma22"), g);
-        assert!(close(back, [0.5, 0.25, 1.0], 1e-9), "{back:?}");
-        // The display's view is that conversion.
-        assert!(close(c.display_path(sp("lin"), "sRGB", "Standard").apply(g, false), [0.5, 0.25, 1.0], 1e-9));
-        // lin → half: matrix and offset; and back through the inverse matrix.
-        let h = c.convert(sp("lin"), sp("half"), [0.4, 0.6, 1.0]);
-        assert!(close(h, [0.3, 0.4, 0.6], 1e-9), "{h:?}");
-        assert!(close(c.convert(sp("half"), sp("lin"), h), [0.4, 0.6, 1.0], 1e-9));
-        // lin → log2: a group (×2 then log2): 0.5 → 0; 2 → 2.
-        let l = c.convert(sp("lin"), sp("log2"), [0.5, 2.0, 4.0]);
-        assert!(close(l, [0.0, 2.0, 3.0], 1e-9), "{l:?}");
-        assert!(close(c.convert(sp("log2"), sp("lin"), l), [0.5, 2.0, 4.0], 1e-9));
-        // LogAffine (inverse direction as to_reference) round-trips.
-        let a = c.convert(sp("lin"), sp("affine"), [0.18, 0.5, 1.0]);
-        let expect = [0.18f64, 0.5, 1.0].map(|v| 0.5 * (2.0 * v + 0.01).log10() + 0.2);
-        assert!(close(a, expect, 1e-9), "{a:?} vs {expect:?}");
-        assert!(close(c.convert(sp("affine"), sp("lin"), a), [0.18, 0.5, 1.0], 1e-9));
-        // FileTransform found on the search path.
-        let f = c.convert(sp("lut"), sp("lin"), [0.25, 0.5, 0.0]);
-        assert!(close(f, [0.5, 1.0, 0.0], 1e-6), "{f:?}");
-        // Data spaces pass through; unsupported transforms are reported.
-        assert_eq!(c.convert(sp("raw"), sp("gamma22"), [0.3, 0.3, 0.3]), [0.3, 0.3, 0.3]);
-        assert_eq!(c.unsupported(), vec!["ExposureContrastTransform".to_string()]);
-        assert_eq!(c.path(sp("lin"), sp("weird")).unsupported_list(), vec!["ExposureContrastTransform".to_string()]);
-        assert!(c.path(sp("lin"), sp("half")).unsupported_list().is_empty());
-        // Loading from a file path (cached), and errors.
-        std::fs::write(dir.join("config.ocio"), CONFIG).unwrap();
-        let loaded = load_config(&dir.join("config.ocio").to_string_lossy()).unwrap();
-        assert_eq!(loaded.spaces.len(), 8);
-        assert!(load_config("/no/such/config.ocio").is_err());
-        assert!(Config::parse("just: text\n", &dir).is_err());
-    }
-
-    /// The OCIO Color Space and Display Transform effects with Configuration ▸ Custom.
-    #[test]
-    fn effects_use_a_custom_config() {
-        use effectcraft_keyframe::Value;
-        let cfg = "ocio_profile_version: 1\nroles:\n  default: lin\ndisplays:\n  Monitor:\n    - !<View> {name: Video, colorspace: g2}\ncolorspaces:\n  - !<ColorSpace>\n    name: lin\n  - !<ColorSpace>\n    name: g2\n    to_reference: !<ExponentTransform> {value: [2, 2, 2, 1]}\n";
-        let img = crate::Image::filled(2, 2, [0.5, 0.25, 1.0, 1.0]);
-        let fx = |id: &str, extra: &[(&str, Value)]| {
-            let mut v = vec![("config", Value::Enum(1)), ("configFile", Value::Str(cfg.into()))];
-            v.extend(extra.iter().cloned());
-            crate::run_fx(id, &v, img.clone(), 0.0, crate::EffectEnv::default()).img.data[0]
-        };
-        let o = fx("ec.color.ociocolorspace", &[("sourceName", Value::Str("g2".into())), ("destinationName", Value::Str("default".into()))]);
-        assert!((o[0] - 0.25).abs() < 1e-6 && (o[1] - 0.0625).abs() < 1e-6 && (o[2] - 1.0).abs() < 1e-6, "{o:?}");
-        // Inverse direction.
-        let o = fx(
-            "ec.color.ociocolorspace",
-            &[("sourceName", Value::Str("g2".into())), ("destinationName", Value::Str("lin".into())), ("direction", Value::Enum(1))],
-        );
-        assert!((o[0] - 0.5f32.sqrt()).abs() < 1e-6, "{o:?}");
-        // Display ▸ view → its colour space.
-        let o = fx(
-            "ec.color.ociodisplay",
-            &[("sourceName", Value::Str("lin".into())), ("displayName", Value::Str("Monitor".into())), ("viewName", Value::Str("Video".into()))],
-        );
-        assert!((o[0] - 0.5f32.sqrt()).abs() < 1e-6, "{o:?}");
-        // An unreadable config leaves pixels alone.
-        let o = crate::run_fx(
-            "ec.color.ociocolorspace",
-            &[("config", Value::Enum(1)), ("configFile", Value::Str("/missing.ocio".into()))],
-            img.clone(),
-            0.0,
-            crate::EffectEnv::default(),
-        );
-        assert_eq!(o.img.data, img.data);
-    }
-
-    /// A config laid out like Blender 4.x / 5.x's (written for this test): the reference space is
-    /// CIE XYZ with the E white, the D65 spaces adapt through a `.spimtx` matrix, sRGB is a
-    /// ColorSpaceTransform plus an ExponentWithLinearTransform, the display-referred spaces meet
-    /// the scene through the default view transform, and a log space uses an
-    /// AllocationTransform.
-    fn blender_like(dir: &Path) -> Config {
-        use effectcraft_color::space::{invert, rgb_to_xyz};
-        let e_to_d65 = crate::ocio::bradford([1.0 / 3.0, 1.0 / 3.0], D65);
-        let rows = |m: [[f64; 3]; 3], sep: &str, end: &str| m.iter().map(|r| format!("{}{sep}{}{sep}{}{end}", r[0], r[1], r[2])).collect::<Vec<_>>();
-        std::fs::write(dir.join("luts/e_to_d65.spimtx"), rows(e_to_d65, " ", " 0\n").concat()).unwrap();
-        let xyz_to_709 = rows(invert(&rgb_to_xyz(REC709, D65)), ", ", ", 0").join(", ");
-        let text = format!(
-            r#"ocio_profile_version: 2.4
-search_path: luts
-roles:
-  reference: Linear CIE-XYZ E
-  scene_linear: Linear Rec.709
-  cie_xyz_d65_interchange: XYZ D65 Display
-default_view_transform: Standard
-view_transforms:
-  - !<ViewTransform>
-    name: Standard
-    from_scene_reference: !<FileTransform> {{src: e_to_d65.spimtx, interpolation: linear}}
-displays:
-  sRGB:
-    - !<View> {{name: Standard, colorspace: sRGB}}
-    - !<View> {{name: Display, view_transform: Standard, display_colorspace: sRGB Display}}
-    - !<View> {{name: Log, colorspace: Log Encoding}}
-    - !<View> {{name: Log Brighter, colorspace: Log Encoding, looks: +Brighter}}
-    - !<View> {{name: Log Darker, colorspace: Log Encoding, looks: "-Brighter, Missing"}}
-    - !<View> {{name: Raw, colorspace: Non-Color}}
-display_colorspaces:
-  - !<ColorSpace>
-    name: XYZ D65 Display
-    isdata: false
-  - !<ColorSpace>
-    name: sRGB Display
-    from_display_reference: !<GroupTransform>
-      children:
-        - !<ColorSpaceTransform> {{src: cie_xyz_d65_interchange, dst: Linear Rec.709}}
-        - !<ExponentWithLinearTransform> {{gamma: 2.4, offset: 0.055, direction: inverse}}
-colorspaces:
-  - !<ColorSpace>
-    name: Linear CIE-XYZ E
-    aliases: [Linear CIE-XYZ I-E]
-  - !<ColorSpace>
-    name: Linear CIE-XYZ D65
-    from_scene_reference: !<FileTransform> {{src: e_to_d65.spimtx, interpolation: linear}}
-  - !<ColorSpace>
-    name: Linear Rec.709
-    from_scene_reference: !<GroupTransform>
-      children:
-        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ I-E, dst: Linear CIE-XYZ D65}}
-        - !<MatrixTransform> {{matrix: [{xyz_to_709}, 0, 0, 0, 1]}}
-  - !<ColorSpace>
-    name: sRGB
-    from_scene_reference: !<GroupTransform>
-      children:
-        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Linear Rec.709}}
-        - !<ExponentWithLinearTransform> {{gamma: 2.4, offset: 0.055, direction: inverse}}
-  - !<ColorSpace>
-    name: Log Encoding
-    from_scene_reference: !<GroupTransform>
-      children:
-        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Linear Rec.709}}
-        - !<AllocationTransform> {{allocation: lg2, vars: [-12, 12]}}
-  - !<ColorSpace>
-    name: ACEScg
-    from_scene_reference: !<GroupTransform>
-      children:
-        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Linear CIE-XYZ D65}}
-        - !<BuiltinTransform> {{style: "UTILITY - ACES-AP1_to_CIE-XYZ-D65_BFD", direction: inverse}}
-  - !<ColorSpace>
-    name: Clipped
-    from_scene_reference: !<GroupTransform>
-      children:
-        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Linear Rec.709}}
-        - !<RangeTransform> {{min_in_value: 0, min_out_value: 0}}
-  - !<ColorSpace>
-    name: Graded
-    from_scene_reference: !<GroupTransform>
-      children:
-        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Linear Rec.709}}
-        - !<GradingToneTransform>
-         shadows: {{rgb: [0.2, 0.2, 0.2], master: 0.35, start: 0.4, pivot: 0.1}}
-  - !<ColorSpace>
-    name: Loop
-    from_scene_reference: !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Loop}}
-  - !<ColorSpace>
-    name: Fan
-    from_scene_reference: !<GroupTransform>
-      children:
-        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Fan}}
-        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Fan}}
-        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Fan}}
-  - !<ColorSpace>
-    name: Non-Color
-    isdata: true
-looks:
-  - !<Look>
-    name: Brighter
-    process_space: Log Encoding
-    transform: !<CDLTransform> {{offset: [0.05, 0.05, 0.05]}}
-"#
-        );
-        Config::parse(&text, dir).unwrap()
-    }
-
-    /// The sRGB encoding (IEC 61966-2-1).
-    fn srgb(v: f64) -> f64 {
-        if v <= 0.003_130_8 { v * 12.92 } else { 1.055 * v.powf(1.0 / 2.4) - 0.055 }
-    }
-
-    /// #410: with Blender's config, Linear Rec.709 → sRGB got no sRGB curve and a blue cast:
-    /// ColorSpaceTransform and ExponentWithLinearTransform passed colours through, so the
-    /// colours stayed in the E-white XYZ reference. Every route to sRGB now encodes greys to
-    /// neutral sRGB values (0.18 → 0.4614).
-    #[test]
-    fn blender_like_config_converts_linear_rec709_to_srgb() {
-        let dir = temp_dir("blender");
-        let c = blender_like(&dir);
-        assert!(c.unsupported().iter().all(|t| t == "GradingToneTransform"), "{:?}", c.unsupported());
-        let sp = |n: &str| c.space(n).unwrap();
-        let lin = sp("scene_linear");
-        let routes = [
-            ("Color Space Transform", c.path(lin, sp("sRGB"))),
-            ("display-referred sRGB", c.path(lin, sp("sRGB Display"))),
-            ("v1 view", c.display_path(lin, "sRGB", "Standard")),
-            ("v2 view", c.display_path(lin, "sRGB", "Display")),
-        ];
-        for (route, x) in &routes {
-            assert!(x.unsupported_list().is_empty(), "{route}: {:?}", x.unsupported_list());
-            for v in [0.0, 0.001, 0.18, 0.5, 1.0, 4.0] {
-                let o = x.apply([v; 3], false);
-                assert!(close(o, [srgb(v); 3], 2e-5), "{route}: {v} → {o:?}, want {}", srgb(v));
-            }
-            let red = x.apply([1.0, 0.0, 0.0], false);
-            assert!(close(red, [1.0, 0.0, 0.0], 1e-4), "{route}: red {red:?}");
-            // And back.
-            assert!(close(x.apply([srgb(0.18); 3], true), [0.18; 3], 1e-6), "{route}");
-        }
-        // AllocationTransform lg2 and a look in its process space; data passes through.
-        let log = |v: f64| (v.log2() + 12.0) / 24.0;
-        let o = c.display_path(lin, "sRGB", "Log").apply([0.18; 3], false);
-        assert!(close(o, [log(0.18); 3], 1e-6), "{o:?}");
-        let o = c.display_path(lin, "sRGB", "Log Brighter").apply([0.18; 3], false);
-        assert!(close(o, [log(0.18) + 0.05; 3], 1e-6), "{o:?}");
-        let darker = c.display_path(lin, "sRGB", "Log Darker");
-        assert!(close(darker.apply([0.18; 3], false), [log(0.18) - 0.05; 3], 1e-6));
-        assert_eq!(darker.unsupported_list(), vec!["Look `Missing` (not in the config)".to_string()]);
-        assert_eq!(c.display_path(lin, "sRGB", "Raw").apply([0.3, 2.0, -1.0], false), [0.3, 2.0, -1.0]);
-        // BuiltinTransform: the built-in config's Linear Rec.709 → ACEScg.
-        let want = crate::ocio::Xform::new(&sp_builtin("Linear Rec.709 (sRGB)"), &sp_builtin("ACEScg")).apply([1.0, 0.25, 0.0]);
-        let got = c.convert(lin, sp("ACEScg"), [1.0, 0.25, 0.0]);
-        assert!(close(got, want.map(f64::from), 1e-4), "{got:?} vs {want:?}");
-        // RangeTransform with only a minimum clamps below and shifts nothing.
-        let o = c.convert(lin, sp("Clipped"), [-0.5, 0.5, 2.0]);
-        assert!(close(o, [0.0, 0.5, 2.0], 1e-6), "{o:?}");
-        // Unsupported steps are listed (and pass through); loops stop.
-        assert_eq!(c.path(lin, sp("Graded")).unsupported_list(), vec!["GradingToneTransform".to_string()]);
-        assert!(c.path(lin, sp("Loop")).unsupported_list()[0].contains("nested"));
-        let fan = c.path(lin, sp("Fan"));
-        assert!(!fan.unsupported_list().is_empty());
-        assert!(matches!(&fan, Xf::Group(v) if v.len() <= MAX_OPS + 1));
-    }
-
-    fn sp_builtin(name: &str) -> Space {
-        *crate::ocio::SPACES.iter().find(|s| s.name == name).unwrap()
-    }
-
-    /// ExponentWithLinearTransform is the sRGB curve at gamma 2.4 / offset 0.055, continuous at
-    /// its break point and inverted exactly; mirror mirrors negatives.
-    #[test]
-    fn moncurve_matches_srgb_and_inverts() {
-        for v in [-0.2, 0.0, 0.002, 0.039, 0.0393, 0.2, 0.5, 1.0, 3.0] {
-            let lin = moncurve(v, 2.4, 0.055, false, false);
-            assert!((moncurve(lin, 2.4, 0.055, true, false) - v).abs() < 1e-12, "{v}");
-            if v >= 0.0 {
-                assert!((moncurve(srgb(v), 2.4, 0.055, false, false) - v).abs() < 2e-5, "{v}");
-            }
-        }
-        let xb = 0.055 / 1.4;
-        assert!((moncurve(xb - 1e-12, 2.4, 0.055, false, false) - moncurve(xb + 1e-12, 2.4, 0.055, false, false)).abs() < 1e-9);
-        assert_eq!(moncurve(-0.5, 2.4, 0.055, false, true), -moncurve(0.5, 2.4, 0.055, false, false));
-        assert_eq!(moncurve(-0.5, 1.0, 0.0, false, false), 0.0);
-    }
-
-    #[test]
-    fn builtin_styles() {
-        for style in ["IDENTITY", "DISPLAY - CIE-XYZ-D65_to_sRGB", "display - cie-xyz-d65_to_rec.2100-pq", "ACEScc_to_ACES2065-1", "ACEScct_to_ACES2065-1"] {
-            assert!(builtin(style).is_some(), "{style}");
-        }
-        assert!(builtin("ACES-OUTPUT - ACES2065-1_to_CIE-XYZ-D65 - SDR-VIDEO_1.0").is_none());
-        // D65 white in XYZ is display white.
-        let xyz = rgb_white_xyz();
-        for style in ["DISPLAY - CIE-XYZ-D65_to_sRGB", "DISPLAY - CIE-XYZ-D65_to_REC.1886-REC.709", "DISPLAY - CIE-XYZ-D65_to_DisplayP3"] {
-            let o = builtin(style).unwrap().apply(xyz, false);
-            assert!(close(o, [1.0; 3], 1e-6), "{style}: {o:?}");
-        }
-        // PQ: 1.0 = 100 nits → code value ≈ 0.508.
-        let pq = builtin("DISPLAY - CIE-XYZ-D65_to_REC.2100-PQ").unwrap().apply(xyz, false);
-        assert!((pq[0] - 0.508).abs() < 1e-3, "{pq:?}");
-        // ACEScc and ACEScct of 0.18 (ACES2065-1 grey stays grey).
-        for (style, code) in [("ACEScc_to_ACES2065-1", 0.413_588_402_492_442_1), ("ACEScct_to_ACES2065-1", 0.413_588_402_492_442_1)] {
-            let o = builtin(style).unwrap().apply([code; 3], false);
-            assert!(close(o, [0.18; 3], 1e-6), "{style}: {o:?}");
-        }
-    }
-
-    fn rgb_white_xyz() -> [f64; 3] {
-        [D65[0] / D65[1], 1.0, (1.0 - D65[0] - D65[1]) / D65[1]]
-    }
-}
+mod tests;
diff --git a/crates/effects/src/ocio_config/tests.rs b/crates/effects/src/ocio_config/tests.rs
new file mode 100644
index 000000000..f534fe0e2
--- /dev/null
+++ b/crates/effects/src/ocio_config/tests.rs
@@ -0,0 +1,394 @@
+use super::*;
+
+const CONFIG: &str = r#"
+ocio_profile_version: 2
+
+name: Test Config   # a comment
+search_path: "luts:other"
+roles:
+  scene_linear: lin
+  color_timing: "log2"
+
+displays:
+  sRGB:
+    - !<View> {name: Standard, colorspace: gamma22}
+    - !<View> {name: Raw, colorspace: raw}
+
+colorspaces:
+  - !<ColorSpace>
+    name: lin
+    family: ""
+    description: |
+      The reference.
+      Linear.
+    isdata: false
+
+  - !<ColorSpace>
+    name: gamma22
+    aliases: [g22, "gamma 2.2"]
+    to_scene_reference: !<ExponentTransform> {value: [2.2, 2.2, 2.2, 1]}
+
+  - !<ColorSpace>
+    name: half
+    from_reference: !<MatrixTransform> {matrix: [0.5, 0, 0, 0,
+                                                0, 0.5, 0, 0,
+                                                0, 0, 0.5, 0,
+                                                0, 0, 0, 1], offset: [0.1, 0.1, 0.1, 0]}
+
+  - !<ColorSpace>
+    name: log2
+    from_reference: !<GroupTransform>
+      children:
+        - !<MatrixTransform> {matrix: [2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 1]}
+        - !<LogTransform> {base: 2}
+
+  - !<ColorSpace>
+    name: affine
+    to_reference: !<LogAffineTransform> {base: 10, logSideSlope: 0.5, logSideOffset: 0.2, linSideSlope: 2, linSideOffset: 0.01, direction: inverse}
+
+  - !<ColorSpace>
+    name: lut
+    to_reference: !<FileTransform> {src: double.cube, interpolation: linear}
+
+  - !<ColorSpace>
+    name: raw
+    isdata: true
+
+  - !<ColorSpace>
+    name: weird
+    to_reference: !<ExposureContrastTransform> {exposure: 1}
+"#;
+
+fn close(a: [f64; 3], b: [f64; 3], tol: f64) -> bool {
+    (0..3).all(|i| (a[i] - b[i]).abs() < tol)
+}
+
+fn temp_dir(name: &str) -> PathBuf {
+    let dir = std::env::temp_dir().join(format!("ec-ocio-{name}-{}", std::process::id()));
+    std::fs::create_dir_all(dir.join("luts")).unwrap();
+    dir
+}
+
+#[test]
+fn yaml_subset() {
+    let y = parse_yaml("a: 1\nb:\n  - x\n  - {k: [1, 2], s: 'q: r'}\nc: !<T> {v: 3}\nd:\n- 4\n- 5\n");
+    assert_eq!(y.get("a").and_then(Yaml::str), Some("1"));
+    assert_eq!(y.get("b").unwrap().seq().len(), 2);
+    assert_eq!(y.get("b").unwrap().seq()[1].get("k").unwrap().nums(), vec![1.0, 2.0]);
+    assert_eq!(y.get("b").unwrap().seq()[1].get("s").and_then(Yaml::str), Some("q: r"));
+    assert_eq!(y.get("c").unwrap().tag(), Some("T"));
+    assert_eq!(y.get("c").unwrap().get("v").and_then(Yaml::str), Some("3"));
+    assert_eq!(y.get("d").unwrap().seq().len(), 2, "a sequence at the key's indent");
+}
+
+/// Hostile nesting (flow brackets and block indentation) is cut off instead of exhausting
+/// the stack.
+#[test]
+fn yaml_nesting_is_bounded() {
+    let flow = format!("a: {}\nb: 1\n", "[".repeat(200_000));
+    assert!(matches!(parse_yaml(&flow), Yaml::Map(_)));
+    let block: String = (0..2_000).map(|i| format!("{}k{i}:\n", " ".repeat(i))).collect();
+    assert!(matches!(parse_yaml(&block), Yaml::Map(_)));
+    let dashes: String = (0..2_000).map(|i| format!("{}- x{i}:\n", " ".repeat(2 * i))).collect();
+    let _ = parse_yaml(&dashes);
+    assert!(Config::parse(&flow, Path::new(".")).is_err());
+}
+
+#[test]
+fn parses_spaces_roles_displays_and_converts() {
+    let dir = temp_dir("basic");
+    // A 1D LUT that doubles (0..1 → 0..2).
+    std::fs::write(dir.join("luts/double.cube"), "LUT_1D_SIZE 2\nDOMAIN_MIN 0 0 0\nDOMAIN_MAX 1 1 1\n0 0 0\n2 2 2\n").unwrap();
+    let c = Config::parse(CONFIG, &dir).unwrap();
+    assert_eq!(c.name, "Test Config");
+    assert_eq!(c.search_path, vec!["luts", "other"]);
+    assert_eq!(c.space_names(), vec!["lin", "gamma22", "half", "log2", "affine", "lut", "raw", "weird"]);
+    // Roles and aliases resolve.
+    assert_eq!(c.space("scene_linear").unwrap().name, "lin");
+    assert_eq!(c.space("G22").unwrap().name, "gamma22");
+    assert_eq!(c.space("gamma 2.2").unwrap().name, "gamma22");
+    assert_eq!(c.view("sRGB", "Standard").unwrap().1.colorspace, "gamma22");
+    let sp = |n: &str| c.space(n).unwrap();
+    // gamma22 → lin: decode with the exponent.
+    let g = c.convert(sp("gamma22"), sp("lin"), [0.5, 0.25, 1.0]);
+    assert!(close(g, [0.5f64.powf(2.2), 0.25f64.powf(2.2), 1.0], 1e-9), "{g:?}");
+    // lin → gamma22: the inverse (only to_reference given).
+    let back = c.convert(sp("lin"), sp("gamma22"), g);
+    assert!(close(back, [0.5, 0.25, 1.0], 1e-9), "{back:?}");
+    // The display's view is that conversion.
+    assert!(close(c.display_path(sp("lin"), "sRGB", "Standard").apply(g, false), [0.5, 0.25, 1.0], 1e-9));
+    // lin → half: matrix and offset; and back through the inverse matrix.
+    let h = c.convert(sp("lin"), sp("half"), [0.4, 0.6, 1.0]);
+    assert!(close(h, [0.3, 0.4, 0.6], 1e-9), "{h:?}");
+    assert!(close(c.convert(sp("half"), sp("lin"), h), [0.4, 0.6, 1.0], 1e-9));
+    // lin → log2: a group (×2 then log2): 0.5 → 0; 2 → 2.
+    let l = c.convert(sp("lin"), sp("log2"), [0.5, 2.0, 4.0]);
+    assert!(close(l, [0.0, 2.0, 3.0], 1e-9), "{l:?}");
+    assert!(close(c.convert(sp("log2"), sp("lin"), l), [0.5, 2.0, 4.0], 1e-9));
+    // LogAffine (inverse direction as to_reference) round-trips.
+    let a = c.convert(sp("lin"), sp("affine"), [0.18, 0.5, 1.0]);
+    let expect = [0.18f64, 0.5, 1.0].map(|v| 0.5 * (2.0 * v + 0.01).log10() + 0.2);
+    assert!(close(a, expect, 1e-9), "{a:?} vs {expect:?}");
+    assert!(close(c.convert(sp("affine"), sp("lin"), a), [0.18, 0.5, 1.0], 1e-9));
+    // FileTransform found on the search path.
+    let f = c.convert(sp("lut"), sp("lin"), [0.25, 0.5, 0.0]);
+    assert!(close(f, [0.5, 1.0, 0.0], 1e-6), "{f:?}");
+    // Data spaces pass through; unsupported transforms are reported.
+    assert_eq!(c.convert(sp("raw"), sp("gamma22"), [0.3, 0.3, 0.3]), [0.3, 0.3, 0.3]);
+    assert_eq!(c.unsupported(), vec!["ExposureContrastTransform".to_string()]);
+    assert_eq!(c.path(sp("lin"), sp("weird")).unsupported_list(), vec!["ExposureContrastTransform".to_string()]);
+    assert!(c.path(sp("lin"), sp("half")).unsupported_list().is_empty());
+    // Loading from a file path (cached), and errors.
+    std::fs::write(dir.join("config.ocio"), CONFIG).unwrap();
+    let loaded = load_config(&dir.join("config.ocio").to_string_lossy()).unwrap();
+    assert_eq!(loaded.spaces.len(), 8);
+    assert!(load_config("/no/such/config.ocio").is_err());
+    assert!(Config::parse("just: text\n", &dir).is_err());
+}
+
+/// The OCIO Color Space and Display Transform effects with Configuration ▸ Custom.
+#[test]
+fn effects_use_a_custom_config() {
+    use effectcraft_keyframe::Value;
+    let cfg = "ocio_profile_version: 1\nroles:\n  default: lin\ndisplays:\n  Monitor:\n    - !<View> {name: Video, colorspace: g2}\ncolorspaces:\n  - !<ColorSpace>\n    name: lin\n  - !<ColorSpace>\n    name: g2\n    to_reference: !<ExponentTransform> {value: [2, 2, 2, 1]}\n";
+    let img = crate::Image::filled(2, 2, [0.5, 0.25, 1.0, 1.0]);
+    let fx = |id: &str, extra: &[(&str, Value)]| {
+        let mut v = vec![("config", Value::Enum(1)), ("configFile", Value::Str(cfg.into()))];
+        v.extend(extra.iter().cloned());
+        crate::run_fx(id, &v, img.clone(), 0.0, crate::EffectEnv::default()).img.data[0]
+    };
+    let o = fx("ec.color.ociocolorspace", &[("sourceName", Value::Str("g2".into())), ("destinationName", Value::Str("default".into()))]);
+    assert!((o[0] - 0.25).abs() < 1e-6 && (o[1] - 0.0625).abs() < 1e-6 && (o[2] - 1.0).abs() < 1e-6, "{o:?}");
+    // Inverse direction.
+    let o =
+        fx("ec.color.ociocolorspace", &[("sourceName", Value::Str("g2".into())), ("destinationName", Value::Str("lin".into())), ("direction", Value::Enum(1))]);
+    assert!((o[0] - 0.5f32.sqrt()).abs() < 1e-6, "{o:?}");
+    // Display ▸ view → its colour space.
+    let o = fx(
+        "ec.color.ociodisplay",
+        &[("sourceName", Value::Str("lin".into())), ("displayName", Value::Str("Monitor".into())), ("viewName", Value::Str("Video".into()))],
+    );
+    assert!((o[0] - 0.5f32.sqrt()).abs() < 1e-6, "{o:?}");
+    // An unreadable config leaves pixels alone.
+    let o = crate::run_fx(
+        "ec.color.ociocolorspace",
+        &[("config", Value::Enum(1)), ("configFile", Value::Str("/missing.ocio".into()))],
+        img.clone(),
+        0.0,
+        crate::EffectEnv::default(),
+    );
+    assert_eq!(o.img.data, img.data);
+}
+
+/// A config laid out like Blender 4.x / 5.x's (written for this test): the reference space is
+/// CIE XYZ with the E white, the D65 spaces adapt through a `.spimtx` matrix, sRGB is a
+/// ColorSpaceTransform plus an ExponentWithLinearTransform, the display-referred spaces meet
+/// the scene through the default view transform, and a log space uses an
+/// AllocationTransform.
+fn blender_like(dir: &Path) -> Config {
+    use effectcraft_color::space::{invert, rgb_to_xyz};
+    let e_to_d65 = crate::ocio::bradford([1.0 / 3.0, 1.0 / 3.0], D65);
+    let rows = |m: [[f64; 3]; 3], sep: &str, end: &str| m.iter().map(|r| format!("{}{sep}{}{sep}{}{end}", r[0], r[1], r[2])).collect::<Vec<_>>();
+    std::fs::write(dir.join("luts/e_to_d65.spimtx"), rows(e_to_d65, " ", " 0\n").concat()).unwrap();
+    let xyz_to_709 = rows(invert(&rgb_to_xyz(REC709, D65)), ", ", ", 0").join(", ");
+    let text = format!(
+        r#"ocio_profile_version: 2.4
+search_path: luts
+roles:
+  reference: Linear CIE-XYZ E
+  scene_linear: Linear Rec.709
+  cie_xyz_d65_interchange: XYZ D65 Display
+default_view_transform: Standard
+view_transforms:
+  - !<ViewTransform>
+    name: Standard
+    from_scene_reference: !<FileTransform> {{src: e_to_d65.spimtx, interpolation: linear}}
+displays:
+  sRGB:
+    - !<View> {{name: Standard, colorspace: sRGB}}
+    - !<View> {{name: Display, view_transform: Standard, display_colorspace: sRGB Display}}
+    - !<View> {{name: Log, colorspace: Log Encoding}}
+    - !<View> {{name: Log Brighter, colorspace: Log Encoding, looks: +Brighter}}
+    - !<View> {{name: Log Darker, colorspace: Log Encoding, looks: "-Brighter, Missing"}}
+    - !<View> {{name: Raw, colorspace: Non-Color}}
+display_colorspaces:
+  - !<ColorSpace>
+    name: XYZ D65 Display
+    isdata: false
+  - !<ColorSpace>
+    name: sRGB Display
+    from_display_reference: !<GroupTransform>
+      children:
+        - !<ColorSpaceTransform> {{src: cie_xyz_d65_interchange, dst: Linear Rec.709}}
+        - !<ExponentWithLinearTransform> {{gamma: 2.4, offset: 0.055, direction: inverse}}
+colorspaces:
+  - !<ColorSpace>
+    name: Linear CIE-XYZ E
+    aliases: [Linear CIE-XYZ I-E]
+  - !<ColorSpace>
+    name: Linear CIE-XYZ D65
+    from_scene_reference: !<FileTransform> {{src: e_to_d65.spimtx, interpolation: linear}}
+  - !<ColorSpace>
+    name: Linear Rec.709
+    from_scene_reference: !<GroupTransform>
+      children:
+        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ I-E, dst: Linear CIE-XYZ D65}}
+        - !<MatrixTransform> {{matrix: [{xyz_to_709}, 0, 0, 0, 1]}}
+  - !<ColorSpace>
+    name: sRGB
+    from_scene_reference: !<GroupTransform>
+      children:
+        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Linear Rec.709}}
+        - !<ExponentWithLinearTransform> {{gamma: 2.4, offset: 0.055, direction: inverse}}
+  - !<ColorSpace>
+    name: Log Encoding
+    from_scene_reference: !<GroupTransform>
+      children:
+        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Linear Rec.709}}
+        - !<AllocationTransform> {{allocation: lg2, vars: [-12, 12]}}
+  - !<ColorSpace>
+    name: ACEScg
+    from_scene_reference: !<GroupTransform>
+      children:
+        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Linear CIE-XYZ D65}}
+        - !<BuiltinTransform> {{style: "UTILITY - ACES-AP1_to_CIE-XYZ-D65_BFD", direction: inverse}}
+  - !<ColorSpace>
+    name: Clipped
+    from_scene_reference: !<GroupTransform>
+      children:
+        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Linear Rec.709}}
+        - !<RangeTransform> {{min_in_value: 0, min_out_value: 0}}
+  - !<ColorSpace>
+    name: Graded
+    from_scene_reference: !<GroupTransform>
+      children:
+        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Linear Rec.709}}
+        - !<GradingToneTransform>
+         shadows: {{rgb: [0.2, 0.2, 0.2], master: 0.35, start: 0.4, pivot: 0.1}}
+  - !<ColorSpace>
+    name: Loop
+    from_scene_reference: !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Loop}}
+  - !<ColorSpace>
+    name: Fan
+    from_scene_reference: !<GroupTransform>
+      children:
+        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Fan}}
+        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Fan}}
+        - !<ColorSpaceTransform> {{src: Linear CIE-XYZ E, dst: Fan}}
+  - !<ColorSpace>
+    name: Non-Color
+    isdata: true
+looks:
+  - !<Look>
+    name: Brighter
+    process_space: Log Encoding
+    transform: !<CDLTransform> {{offset: [0.05, 0.05, 0.05]}}
+"#
+    );
+    Config::parse(&text, dir).unwrap()
+}
+
+/// The sRGB encoding (IEC 61966-2-1).
+fn srgb(v: f64) -> f64 {
+    if v <= 0.003_130_8 { v * 12.92 } else { 1.055 * v.powf(1.0 / 2.4) - 0.055 }
+}
+
+/// #410: with Blender's config, Linear Rec.709 → sRGB got no sRGB curve and a blue cast:
+/// ColorSpaceTransform and ExponentWithLinearTransform passed colours through, so the
+/// colours stayed in the E-white XYZ reference. Every route to sRGB now encodes greys to
+/// neutral sRGB values (0.18 → 0.4614).
+#[test]
+fn blender_like_config_converts_linear_rec709_to_srgb() {
+    let dir = temp_dir("blender");
+    let c = blender_like(&dir);
+    assert!(c.unsupported().iter().all(|t| t == "GradingToneTransform"), "{:?}", c.unsupported());
+    let sp = |n: &str| c.space(n).unwrap();
+    let lin = sp("scene_linear");
+    let routes = [
+        ("Color Space Transform", c.path(lin, sp("sRGB"))),
+        ("display-referred sRGB", c.path(lin, sp("sRGB Display"))),
+        ("v1 view", c.display_path(lin, "sRGB", "Standard")),
+        ("v2 view", c.display_path(lin, "sRGB", "Display")),
+    ];
+    for (route, x) in &routes {
+        assert!(x.unsupported_list().is_empty(), "{route}: {:?}", x.unsupported_list());
+        for v in [0.0, 0.001, 0.18, 0.5, 1.0, 4.0] {
+            let o = x.apply([v; 3], false);
+            assert!(close(o, [srgb(v); 3], 2e-5), "{route}: {v} → {o:?}, want {}", srgb(v));
+        }
+        let red = x.apply([1.0, 0.0, 0.0], false);
+        assert!(close(red, [1.0, 0.0, 0.0], 1e-4), "{route}: red {red:?}");
+        // And back.
+        assert!(close(x.apply([srgb(0.18); 3], true), [0.18; 3], 1e-6), "{route}");
+    }
+    // AllocationTransform lg2 and a look in its process space; data passes through.
+    let log = |v: f64| (v.log2() + 12.0) / 24.0;
+    let o = c.display_path(lin, "sRGB", "Log").apply([0.18; 3], false);
+    assert!(close(o, [log(0.18); 3], 1e-6), "{o:?}");
+    let o = c.display_path(lin, "sRGB", "Log Brighter").apply([0.18; 3], false);
+    assert!(close(o, [log(0.18) + 0.05; 3], 1e-6), "{o:?}");
+    let darker = c.display_path(lin, "sRGB", "Log Darker");
+    assert!(close(darker.apply([0.18; 3], false), [log(0.18) - 0.05; 3], 1e-6));
+    assert_eq!(darker.unsupported_list(), vec!["Look `Missing` (not in the config)".to_string()]);
+    assert_eq!(c.display_path(lin, "sRGB", "Raw").apply([0.3, 2.0, -1.0], false), [0.3, 2.0, -1.0]);
+    // BuiltinTransform: the built-in config's Linear Rec.709 → ACEScg.
+    let want = crate::ocio::Xform::new(&sp_builtin("Linear Rec.709 (sRGB)"), &sp_builtin("ACEScg")).apply([1.0, 0.25, 0.0]);
+    let got = c.convert(lin, sp("ACEScg"), [1.0, 0.25, 0.0]);
+    assert!(close(got, want.map(f64::from), 1e-4), "{got:?} vs {want:?}");
+    // RangeTransform with only a minimum clamps below and shifts nothing.
+    let o = c.convert(lin, sp("Clipped"), [-0.5, 0.5, 2.0]);
+    assert!(close(o, [0.0, 0.5, 2.0], 1e-6), "{o:?}");
+    // Unsupported steps are listed (and pass through); loops stop.
+    assert_eq!(c.path(lin, sp("Graded")).unsupported_list(), vec!["GradingToneTransform".to_string()]);
+    assert!(c.path(lin, sp("Loop")).unsupported_list()[0].contains("nested"));
+    let fan = c.path(lin, sp("Fan"));
+    assert!(!fan.unsupported_list().is_empty());
+    assert!(matches!(&fan, Xf::Group(v) if v.len() <= MAX_OPS + 1));
+}
+
+fn sp_builtin(name: &str) -> Space {
+    *crate::ocio::SPACES.iter().find(|s| s.name == name).unwrap()
+}
+
+/// ExponentWithLinearTransform is the sRGB curve at gamma 2.4 / offset 0.055, continuous at
+/// its break point and inverted exactly; mirror mirrors negatives.
+#[test]
+fn moncurve_matches_srgb_and_inverts() {
+    for v in [-0.2, 0.0, 0.002, 0.039, 0.0393, 0.2, 0.5, 1.0, 3.0] {
+        let lin = moncurve(v, 2.4, 0.055, false, false);
+        assert!((moncurve(lin, 2.4, 0.055, true, false) - v).abs() < 1e-12, "{v}");
+        if v >= 0.0 {
+            assert!((moncurve(srgb(v), 2.4, 0.055, false, false) - v).abs() < 2e-5, "{v}");
+        }
+    }
+    let xb = 0.055 / 1.4;
+    assert!((moncurve(xb - 1e-12, 2.4, 0.055, false, false) - moncurve(xb + 1e-12, 2.4, 0.055, false, false)).abs() < 1e-9);
+    assert_eq!(moncurve(-0.5, 2.4, 0.055, false, true), -moncurve(0.5, 2.4, 0.055, false, false));
+    assert_eq!(moncurve(-0.5, 1.0, 0.0, false, false), 0.0);
+}
+
+#[test]
+fn builtin_styles() {
+    for style in ["IDENTITY", "DISPLAY - CIE-XYZ-D65_to_sRGB", "display - cie-xyz-d65_to_rec.2100-pq", "ACEScc_to_ACES2065-1", "ACEScct_to_ACES2065-1"] {
+        assert!(builtin(style).is_some(), "{style}");
+    }
+    assert!(builtin("ACES-OUTPUT - ACES2065-1_to_CIE-XYZ-D65 - SDR-VIDEO_1.0").is_none());
+    // D65 white in XYZ is display white.
+    let xyz = rgb_white_xyz();
+    for style in ["DISPLAY - CIE-XYZ-D65_to_sRGB", "DISPLAY - CIE-XYZ-D65_to_REC.1886-REC.709", "DISPLAY - CIE-XYZ-D65_to_DisplayP3"] {
+        let o = builtin(style).unwrap().apply(xyz, false);
+        assert!(close(o, [1.0; 3], 1e-6), "{style}: {o:?}");
+    }
+    // PQ: 1.0 = 100 nits → code value ≈ 0.508.
+    let pq = builtin("DISPLAY - CIE-XYZ-D65_to_REC.2100-PQ").unwrap().apply(xyz, false);
+    assert!((pq[0] - 0.508).abs() < 1e-3, "{pq:?}");
+    // ACEScc and ACEScct of 0.18 (ACES2065-1 grey stays grey).
+    for (style, code) in [("ACEScc_to_ACES2065-1", 0.413_588_402_492_442_1), ("ACEScct_to_ACES2065-1", 0.413_588_402_492_442_1)] {
+        let o = builtin(style).unwrap().apply([code; 3], false);
+        assert!(close(o, [0.18; 3], 1e-6), "{style}: {o:?}");
+    }
+}
+
+fn rgb_white_xyz() -> [f64; 3] {
+    [D65[0] / D65[1], 1.0, (1.0 - D65[0] - D65[1]) / D65[1]]
+}
diff --git a/crates/effects/src/puppet/mod.rs b/crates/effects/src/puppet.rs
similarity index 100%
rename from crates/effects/src/puppet/mod.rs
rename to crates/effects/src/puppet.rs
diff --git a/crates/effects/src/roto.rs b/crates/effects/src/roto.rs
index 4917cc231..2467a719d 100644
--- a/crates/effects/src/roto.rs
+++ b/crates/effects/src/roto.rs
@@ -634,7 +634,7 @@ fn render(ctx: &EffectCtx, buf: Buf) -> Buf {
     let (w, h) = (img.width as usize, img.height as usize);
     let mp = matte_params(ctx.params);
     let mut rgb = rb::rgb_of(&img);
-    let map = refine::decontaminate(&mut rgb, &alpha, &band, w, h, &mp, rr * sc, sc);
+    let map = refine::decontaminate(&mut rgb, &alpha, &band, (w, h), &mp, rr * sc, sc);
     let view_map = b(ctx.params, "refineEdgeMatte/decontamination/viewDecontaminationMap");
     let (ox, oy) = (buf.offset[0].round() as i64, buf.offset[1].round() as i64);
     for y in 0..h {
diff --git a/crates/effects/src/sim.rs b/crates/effects/src/sim.rs
index 1bb82f46e..3a0743af2 100644
--- a/crates/effects/src/sim.rs
+++ b/crates/effects/src/sim.rs
@@ -18,2016 +18,25 @@ use crate::generate::value_noise;
 use crate::util::{SimCache, hash1, params_key, params_key_except, unpremul};
 use crate::{Buf, EffectCtx, EffectSpec, col, num, p, popup, slider};
 
-pub(crate) fn spec(id: &'static str, name: &'static str, params: Vec<crate::ParamSpec>, render: crate::RenderFn) -> EffectSpec {
-    EffectSpec { id, name, category: "Simulation", params, render, gpu: false, float: true }
-}
-
-pub(crate) fn pt(x: f64, y: f64) -> Value {
-    Value::Vec2([x, y])
-}
-
-pub(crate) fn pct() -> ParamUi {
-    slider(0.0, 100.0, 0.0, 100.0, 1)
-}
-
-/// Deterministic hash → [0, 1).
-#[inline]
-pub(crate) fn h(i: u32, k: u32, seed: u32) -> f32 {
-    hash1(i, k, seed)
-}
-
-/// Signed hash → [-1, 1).
-#[inline]
-pub(crate) fn hs(i: u32, k: u32, seed: u32) -> f32 {
-    hash1(i, k, seed) * 2.0 - 1.0
-}
-
-// ------------------------------------------------------------------ band rasteriser
-
-const BAND: usize = 16;
-
-/// How rasterised items combine with what is already in the target.
-#[derive(Clone, Copy, PartialEq, Eq, Debug)]
-pub enum Acc {
-    /// Premultiplied "over" (later items on top).
-    Over,
-    /// Additive (glows, light).
-    Add,
-}
-
-/// Rasterise many small items into `img` (buffer pixels). `bbox` gives an item's pixel bounds
-/// `[x0, y0, x1, y1]` (or `None` to skip), `shade` its premultiplied colour at a pixel centre.
-/// Items are bucketed into horizontal bands rendered in parallel; within a band they are drawn
-/// in slice order.
-pub(crate) fn raster<T: Sync>(
-    img: &mut Image,
-    items: &[T],
-    bbox: impl Fn(&T) -> Option<[f32; 4]> + Sync,
-    shade: impl Fn(&T, f32, f32) -> Option<Px> + Sync,
-    acc: Acc,
-) {
-    let (w, hgt) = (img.width as usize, img.height as usize);
-    if w == 0 || hgt == 0 || items.is_empty() {
-        return;
-    }
-    let nb = hgt.div_ceil(BAND);
-    let boxes: Vec<Option<[i32; 4]>> = items
-        .par_iter()
-        .map(|it| {
-            let b = bbox(it)?;
-            if !(b[0].is_finite() && b[1].is_finite() && b[2].is_finite() && b[3].is_finite()) {
-                return None;
-            }
-            let x0 = b[0].floor().max(0.0) as i32;
-            let y0 = b[1].floor().max(0.0) as i32;
-            let x1 = (b[2].ceil() as i32).min(w as i32 - 1);
-            let y1 = (b[3].ceil() as i32).min(hgt as i32 - 1);
-            if x1 < x0 || y1 < y0 || b[2] < 0.0 || b[3] < 0.0 {
-                return None;
-            }
-            Some([x0, y0, x1, y1])
-        })
-        .collect();
-    let mut buckets: Vec<Vec<u32>> = vec![Vec::new(); nb];
-    for (i, b) in boxes.iter().enumerate() {
-        if let Some(b) = b {
-            for band in (b[1] as usize / BAND)..=(b[3] as usize / BAND).min(nb - 1) {
-                buckets[band].push(i as u32);
-            }
-        }
-    }
-    img.data.par_chunks_mut(w * BAND).enumerate().for_each(|(band, chunk)| {
-        let by0 = band * BAND;
-        let rows = chunk.len() / w;
-        for &i in &buckets[band] {
-            let Some(b) = boxes[i as usize] else { continue };
-            let it = &items[i as usize];
-            let ya = (b[1] as usize).max(by0);
-            let yb = (b[3] as usize).min(by0 + rows - 1);
-            for y in ya..=yb {
-                let row = &mut chunk[(y - by0) * w..(y - by0 + 1) * w];
-                for x in b[0] as usize..=b[2] as usize {
-                    if let Some(c) = shade(it, x as f32 + 0.5, y as f32 + 0.5) {
-                        let d = &mut row[x];
-                        match acc {
-                            Acc::Over => {
-                                let k = 1.0 - c[3];
-                                *d = [c[0] + d[0] * k, c[1] + d[1] * k, c[2] + d[2] * k, c[3] + d[3] * k];
-                            }
-                            Acc::Add => {
-                                *d = [d[0] + c[0], d[1] + c[1], d[2] + c[2], (d[3] + c[3]).min(1.0)];
-                            }
-                        }
-                    }
-                }
-            }
-        }
-    });
-}
-
-// ------------------------------------------------------------------ sprites
-
-#[derive(Clone, Copy, PartialEq, Debug)]
-pub enum Shape {
-    /// Soft round dot (Gaussian-like falloff).
-    Soft,
-    /// Hard anti-aliased disc.
-    Disc,
-    /// Lit sphere (upper-left light, specular).
-    Sphere,
-    /// Disc fading linearly to its rim.
-    Faded,
-    /// Thin ring with a highlight.
-    Bubble,
-    /// Four-point star.
-    Star,
-    /// Rotated square (angle in `rot`).
-    Square,
-    /// Triangle (angle in `rot`).
-    Tri,
-    /// Segment from (x, y) by (dx, dy), half-width `r`.
-    Line { dx: f32, dy: f32 },
-}
-
-/// A particle sprite in buffer pixels; `c` is straight colour + opacity.
-#[derive(Clone, Copy, Debug)]
-pub struct Sprite {
-    pub x: f32,
-    pub y: f32,
-    pub r: f32,
-    pub c: [f32; 4],
-    pub shape: Shape,
-    pub rot: f32,
-}
-
-impl Sprite {
-    pub(crate) fn new(x: f32, y: f32, r: f32, c: [f32; 4], shape: Shape) -> Sprite {
-        Sprite { x, y, r, c, shape, rot: 0.0 }
-    }
-}
-
-/// Where a sprite's colour comes from when it depends on the layer's pixels (resolved by
-/// [`SpritePlan::resolve`] on the CPU, per pixel by the GPU compositor). Positions are buffer
-/// pixels.
-#[derive(Clone, Copy, Debug)]
-pub enum Tint {
-    /// The sprite's own colour.
-    Fixed,
-    /// CC Rainfall's refracting drops: where the layer shows (alpha > 0), colour × (layer
-    /// colour × 0.6 + 0.5) sampled at (x, y).
-    Refract { x: f64, y: f64 },
-    /// CC Star Burst: the layer's colour at (x, y), opacity × its alpha (none where clear).
-    Source { x: f64, y: f64 },
-    /// CC Hair: the root's colour at (x, y) mixed with the hair colour (`inherit` = 1 keeps the
-    /// root's), × `shade`, + `spec`; no strand where the root's alpha is below ½.
-    Root { x: f64, y: f64, hair: [f32; 3], inherit: f32, shade: f32, spec: f32 },
-}
-
-/// How a sprite layer meets the original layer.
-#[derive(Clone, Copy, Debug, PartialEq)]
-pub enum Post {
-    /// `combine` with this mode (0 Composite … 5 sprites only).
-    Combine(u32),
-    /// The sprites alone.
-    Replace,
-    /// The sprites, mixed toward the original by this fraction.
-    Lerp(f32),
-    /// The sprites over opaque black.
-    OverBlack,
-}
-
-/// What a sprite-drawing effect draws this frame: built on the CPU (closed-form or from the
-/// simulation state), rasterised by [`SpritePlan::finish`] or the GPU compositor.
-#[derive(Clone, Debug)]
-pub struct SpritePlan {
-    pub sprites: Vec<Sprite>,
-    /// Per sprite (empty = all [`Tint::Fixed`]).
-    pub tints: Vec<Tint>,
-    pub acc: Acc,
-    pub post: Post,
-}
-
-impl SpritePlan {
-    /// Resolve layer-dependent colours against the layer `src`.
-    pub fn resolve(&mut self, src: &Image) {
-        let tints = std::mem::take(&mut self.tints);
-        self.sprites.par_iter_mut().zip(tints.par_iter()).for_each(|(sp, t)| match *t {
-            Tint::Fixed => {}
-            Tint::Refract { x, y } => {
-                let (sc, sa) = unpremul(src.sample_bilinear(x, y));
-                if sa > 0.0 {
-                    let c = sp.c;
-                    sp.c = [(sc[0] * 0.6 + 0.5) * c[0], (sc[1] * 0.6 + 0.5) * c[1], (sc[2] * 0.6 + 0.5) * c[2], c[3]];
-                }
-            }
-            Tint::Source { x, y } => {
-                let (c, a) = unpremul(src.sample_bilinear(x, y));
-                sp.c = if a <= 0.0 { [0.0; 4] } else { [c[0], c[1], c[2], a * sp.c[3]] };
-            }
-            Tint::Root { x, y, hair, inherit, shade, spec } => {
-                let root = src.sample_bilinear(x, y);
-                if root[3] < 0.5 {
-                    sp.c = [0.0; 4];
-                    return;
-                }
-                let (rc, _) = unpremul(root);
-                let base: [f32; 3] = std::array::from_fn(|k| rc[k] + (hair[k] - rc[k]) * (1.0 - inherit));
-                sp.c = [base[0] * shade + spec, base[1] * shade + spec, base[2] * shade + spec, sp.c[3]];
-            }
-        });
-    }
-
-    /// Rasterise (after [`SpritePlan::resolve`]) and meet the original layer `b`.
-    pub fn finish(&self, b: Buf) -> Buf {
-        let fx = splat(b.img.width, b.img.height, &self.sprites, self.acc);
-        self.finish_with(b, fx)
-    }
-
-    /// [`finish`](Self::finish) with a prepared sprite image (the motion-blurred average of
-    /// several frames, #1195).
-    pub fn finish_with(&self, b: Buf, fx: Image) -> Buf {
-        self.post.apply(b, fx)
-    }
-}
-
-impl Post {
-    /// Meet the sprite image `fx` with the original layer `b` (see [`SpritePlan::finish`]).
-    fn apply(self, mut b: Buf, fx: Image) -> Buf {
-        b.img = match self {
-            Post::Combine(m) => combine(&b.img, &fx, m),
-            Post::Replace => fx,
-            Post::Lerp(t) => {
-                let mut o = fx;
-                o.data.par_iter_mut().zip(b.img.data.par_iter()).for_each(|(o, s0)| *o = crate::util::lerp4(*o, *s0, t));
-                o
-            }
-            Post::OverBlack => combine(&Image::filled(b.img.width, b.img.height, [0.0, 0.0, 0.0, 1.0]), &fx, 0),
-        };
-        b
-    }
-}
-
-/// The sprite plan of a sprite-drawing simulation effect for buffer geometry `b` (its pixels
-/// are not read), `None` for other effects or settings drawn otherwise (the GPU compositor's
-/// render pass).
-pub fn sprite_plan(id: &str, ctx: &EffectCtx, b: &Buf) -> Option<SpritePlan> {
-    match id {
-        "ec.sim.ccrainfall" => Some(rainfall_plan(ctx, b)),
-        "ec.sim.ccsnowfall" => Some(snowfall_plan(ctx, b)),
-        "ec.sim.ccstarburst" => Some(star_burst_plan(ctx, b)),
-        "ec.sim.cchair" => crate::sim3::hair_plan(ctx, b),
-        "ec.sim.waveworld" => crate::sim2::wave_world_plan(ctx, b).and_then(|p| match p {
-            crate::sim2::WavePlan::Wire(sp) => Some(sp),
-            crate::sim2::WavePlan::Height { .. } => None,
-        }),
-        "ec.sim.foam" => crate::sim2::foam_plan(ctx, b),
-        "ec.sim.ccparticleworld" => particle_world_plan(ctx, b),
-        "ec.sim.ccparticlesystems2" => Some(particle_systems2_plan(ctx, b)),
-        _ => None,
-    }
-}
-
-fn sprite_bbox(s: &Sprite) -> Option<[f32; 4]> {
-    if s.c[3] <= 1e-5 || s.r <= 0.0 {
-        return None;
-    }
-    let r = s.r.max(0.5) + 1.0;
-    Some(match s.shape {
-        Shape::Line { dx, dy } => [s.x.min(s.x + dx) - r, s.y.min(s.y + dy) - r, s.x.max(s.x + dx) + r, s.y.max(s.y + dy) + r],
-        Shape::Star => [s.x - r * 2.0, s.y - r * 2.0, s.x + r * 2.0, s.y + r * 2.0],
-        _ => [s.x - r, s.y - r, s.x + r, s.y + r],
-    })
-}
-
-#[inline]
-fn aa(edge: f32) -> f32 {
-    (edge + 0.5).clamp(0.0, 1.0)
-}
-
-fn sprite_shade(s: &Sprite, x: f32, y: f32) -> Option<Px> {
-    // Sub-pixel sprites keep their energy: draw at radius 0.5 with reduced opacity.
-    let (r, fade) = if s.r < 0.5 { (0.5, s.r / 0.5) } else { (s.r, 1.0) };
-    let (dx, dy) = (x - s.x, y - s.y);
-    let mut rgb = [s.c[0], s.c[1], s.c[2]];
-    let cov = match s.shape {
-        Shape::Soft => {
-            let d2 = (dx * dx + dy * dy) / (r * r);
-            if d2 >= 1.0 {
-                return None;
-            }
-            let q = 1.0 - d2;
-            q * q
-        }
-        Shape::Disc => aa(r - (dx * dx + dy * dy).sqrt()),
-        Shape::Faded => {
-            let d = (dx * dx + dy * dy).sqrt() / r;
-            (1.0 - d).max(0.0).powf(1.5)
-        }
-        Shape::Sphere => {
-            let d = (dx * dx + dy * dy).sqrt();
-            let cv = aa(r - d);
-            if cv <= 0.0 {
-                return None;
-            }
-            let (nx, ny) = (dx / r, dy / r);
-            let nz = (1.0 - nx * nx - ny * ny).max(0.0).sqrt();
-            let (lx, ly, lz) = (-0.48, -0.58, 0.66);
-            let diff = (nx * lx + ny * ly + nz * lz).max(0.0);
-            let rz = 2.0 * diff * nz - lz;
-            let spec = rz.max(0.0).powi(20) * 0.6;
-            let k = 0.2 + 0.8 * diff;
-            rgb = [rgb[0] * k + spec, rgb[1] * k + spec, rgb[2] * k + spec];
-            cv
-        }
-        Shape::Bubble => {
-            let d = (dx * dx + dy * dy).sqrt() / r;
-            if d > 1.0 + 1.0 / r {
-                return None;
-            }
-            let ring = (1.0 - ((d - 0.9) / 0.12).powi(2)).max(0.0);
-            let hl = (1.0 - (((dx / r) + 0.4).powi(2) + ((dy / r) + 0.4).powi(2)) / 0.04).max(0.0);
-            (0.12 * (d <= 1.0) as u8 as f32 + ring * 0.8 + hl).min(1.0)
-        }
-        Shape::Star => {
-            let (sn, cs) = s.rot.sin_cos();
-            let (ux, uy) = ((dx * cs + dy * sn) / r, (-dx * sn + dy * cs) / r);
-            let d = (ux * ux + uy * uy).sqrt();
-            let core = (1.0 - d).max(0.0).powi(2);
-            let sx = (1.0 - ux.abs() / 2.0).max(0.0) * (1.0 - (uy.abs() * 6.0)).max(0.0);
-            let sy = (1.0 - uy.abs() / 2.0).max(0.0) * (1.0 - (ux.abs() * 6.0)).max(0.0);
-            (core + sx + sy).min(1.0)
-        }
-        Shape::Square => {
-            let (sn, cs) = s.rot.sin_cos();
-            let (ux, uy) = (dx * cs + dy * sn, -dx * sn + dy * cs);
-            let e = r * 0.75;
-            aa(e - ux.abs()) * aa(e - uy.abs())
-        }
-        Shape::Tri => {
-            let (sn, cs) = s.rot.sin_cos();
-            let (ux, uy) = (dx * cs + dy * sn, -dx * sn + dy * cs);
-            // Equilateral triangle with circumradius r: three half-planes.
-            let e = r * 0.5;
-            let mut m = f32::INFINITY;
-            for k in 0..3 {
-                let a = std::f32::consts::FRAC_PI_2 + k as f32 * std::f32::consts::TAU / 3.0;
-                let (ns, nc) = a.sin_cos();
-                m = m.min(e - (ux * nc + uy * ns));
-            }
-            aa(m)
-        }
-        Shape::Line { dx: lx, dy: ly } => {
-            let l2 = lx * lx + ly * ly;
-            let t = if l2 > 0.0 { ((dx * lx + dy * ly) / l2).clamp(0.0, 1.0) } else { 0.0 };
-            let (px, py) = (dx - lx * t, dy - ly * t);
-            aa(r - (px * px + py * py).sqrt())
-        }
-    };
-    let a = cov * s.c[3] * fade;
-    if a <= 1e-6 {
-        return None;
-    }
-    Some([rgb[0] * a, rgb[1] * a, rgb[2] * a, a])
-}
-
-/// Draw sprites into a new transparent image of `w`×`h`.
-pub(crate) fn splat(w: u32, hgt: u32, sprites: &[Sprite], acc: Acc) -> Image {
-    let mut img = Image::new(w, hgt);
-    raster(&mut img, sprites, sprite_bbox, sprite_shade, acc);
-    img
-}
-
-/// Combine an effect layer `fx` with the original `src` (both premultiplied, same size):
-/// 0 Composite (fx over src), 1 Screen, 2 Add, 3 Lighten, 4 Darken, 5 fx only.
-pub(crate) fn combine(src: &Image, fx: &Image, mode: u32) -> Image {
-    let mut out = fx.clone();
-    out.data.par_iter_mut().zip(src.data.par_iter()).for_each(|(o, s)| {
-        let f = *o;
-        *o = match mode {
-            0 => {
-                let k = 1.0 - f[3];
-                [f[0] + s[0] * k, f[1] + s[1] * k, f[2] + s[2] * k, f[3] + s[3] * k]
-            }
-            1 => [s[0] + f[0] - s[0] * f[0], s[1] + f[1] - s[1] * f[1], s[2] + f[2] - s[2] * f[2], s[3] + f[3] - s[3] * f[3]],
-            2 => [s[0] + f[0], s[1] + f[1], s[2] + f[2], (s[3] + f[3]).min(1.0)],
-            3 => [s[0].max(f[0]), s[1].max(f[1]), s[2].max(f[2]), s[3] + f[3] - s[3] * f[3]],
-            4 => {
-                let (fc, fa) = unpremul(f);
-                let m = |c: f32, k: usize| c - (c - c.min(fc[k] * s[3])) * fa;
-                [m(s[0], 0), m(s[1], 1), m(s[2], 2), s[3]]
-            }
-            _ => f,
-        };
-    });
-    out
-}
-
-// ------------------------------------------------------------------ CC Rainfall / CC Snowfall
-
-/// Shared weather layout: per-item depth factor `k` in (0, 1] (1 = nearest) from Scene Depth.
-#[inline]
-fn depth_k(z: f32, scene_depth: f32) -> f32 {
-    1.0 / (1.0 + z * scene_depth / 2500.0)
-}
-
-/// Wrap `v` into `[lo, lo + span)`.
-#[inline]
-fn wrap(v: f32, lo: f32, span: f32) -> f32 {
-    if span <= 0.0 { v } else { lo + (v - lo).rem_euclid(span) }
-}
-
-fn rainfall(ctx: &EffectCtx, b: Buf) -> Buf {
-    let mut plan = rainfall_plan(ctx, &b);
-    plan.resolve(&b.img);
-    plan.finish(b)
-}
-
-fn rainfall_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
-    let pr = ctx.params;
-    let n = pr.f("drops").clamp(0.0, 100_000.0) as u32;
-    let size = pr.f("size").max(0.0) as f32;
-    let depth = pr.f("sceneDepth").max(0.0) as f32;
-    let speed = pr.f("speed") as f32;
-    let wind = pr.f("wind") as f32;
-    let wvar = pr.f("windVariation") as f32 / 100.0;
-    let spread = pr.f("spread") as f32;
-    let color = pr.color("color");
-    let opacity = pr.f("opacity") as f32 / 100.0;
-    let mode = pr.e("transferMode");
-    let with_orig = pr.b("compositeWithOriginal");
-    let refract = pr.e("extras/appearance") == 0;
-    let off = pr.v2("extras/offset");
-    let seed = pr.f("extras/randomSeed") as u32 ^ ctx.seed.wrapping_mul(0x9e37);
-    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
-    let s = b.scale as f32;
-    let t = ctx.time as f32;
-    let (ox, oy) = (off[0] as f32 - lw * 0.5, off[1] as f32 - lh * 0.5);
-    let (sprites, tints): (Vec<Sprite>, Vec<Tint>) = (0..n)
-        .into_par_iter()
-        .map(|i| {
-            let z = h(i, 1, seed);
-            let k = depth_k(z, depth);
-            let vy = speed / 4000.0 * lh * 2.2 * k;
-            let w = wind / 1000.0 * lh * (1.0 + wvar * hs(i, 2, seed)) * k + spread * hs(i, 7, seed) * k;
-            let len = (vy * 0.04 * size.max(0.2)).max(1.0);
-            let lenx = w * 0.04 * size.max(0.2);
-            let margin = len + lenx.abs() + 4.0;
-            let y = wrap(h(i, 3, seed) * (lh + 2.0 * margin) + vy * t + oy, -margin, lh + 2.0 * margin);
-            let x = wrap(h(i, 4, seed) * (lw + 2.0 * margin) + w * t + ox, -margin, lw + 2.0 * margin);
-            let (bx, by) = b.to_px([x as f64, y as f64]);
-            let c = [color[0], color[1], color[2], opacity * (0.35 + 0.65 * k)];
-            // Refracting drops show the scene behind them, brightened and offset.
-            let tint = if refract { Tint::Refract { x: bx + 2.0 * s as f64, y: by } } else { Tint::Fixed };
-            let r = (size * 0.6 * k * s).max(0.25);
-            (Sprite::new(bx as f32, by as f32, r, c, Shape::Line { dx: -lenx * s, dy: -len * s }), tint)
-        })
-        .unzip();
-    SpritePlan { sprites, tints, acc: Acc::Over, post: weather_post(mode, with_orig) }
-}
-
-fn weather_post(mode: u32, with_orig: bool) -> Post {
-    if with_orig { Post::Combine(if mode == 1 { 3 } else { 0 }) } else { Post::Replace }
-}
-
-fn snowfall(ctx: &EffectCtx, b: Buf) -> Buf {
-    snowfall_plan(ctx, &b).finish(b)
-}
-
-fn snowfall_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
-    let pr = ctx.params;
-    let n = pr.f("flakes").clamp(0.0, 200_000.0) as u32;
-    let size = pr.f("size").max(0.0) as f32;
-    let svar = pr.f("sizeVariation") as f32 / 100.0;
-    let depth = pr.f("sceneDepth").max(0.0) as f32;
-    let speed = pr.f("speed") as f32;
-    let spvar = pr.f("speedVariation") as f32 / 100.0;
-    let wind = pr.f("wind") as f32;
-    let wvar = pr.f("windVariation") as f32 / 100.0;
-    let spread = pr.f("spread") as f32;
-    let wig = pr.f("wiggle/wiggleAmount") as f32;
-    let wigvar = pr.f("wiggle/wiggleAmountVariation") as f32 / 100.0;
-    let wfreq = pr.f("wiggle/wiggleFrequency") as f32;
-    let wfvar = pr.f("wiggle/wiggleFrequencyVariation") as f32 / 100.0;
-    let color = pr.color("color");
-    let opacity = pr.f("opacity") as f32 / 100.0;
-    let mode = pr.e("transferMode");
-    let with_orig = pr.b("compositeWithOriginal");
-    let off = pr.v2("extras/offset");
-    let seed = pr.f("extras/randomSeed") as u32 ^ ctx.seed.wrapping_mul(0x85eb);
-    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
-    let s = b.scale as f32;
-    let t = ctx.time as f32;
-    let (ox, oy) = (off[0] as f32 - lw * 0.5, off[1] as f32 - lh * 0.5);
-    let sprites: Vec<Sprite> = (0..n)
-        .into_par_iter()
-        .map(|i| {
-            let z = h(i, 1, seed);
-            let k = depth_k(z, depth);
-            let r = (size * 0.5 * k * (1.0 + svar * hs(i, 2, seed))).max(0.05);
-            let vy = speed * (lh / 600.0) * k * (1.0 + spvar * hs(i, 3, seed));
-            let vx = wind * (lh / 1200.0) * k * (1.0 + wvar * hs(i, 4, seed)) + spread * hs(i, 8, seed) * k;
-            let amp = wig * 2.0 * k * (1.0 + wigvar * hs(i, 5, seed));
-            let fr = wfreq * (1.0 + wfvar * hs(i, 6, seed));
-            let ph = h(i, 9, seed) * std::f32::consts::TAU;
-            let margin = r + amp.abs() + 2.0;
-            let y = wrap(h(i, 10, seed) * (lh + 2.0 * margin) + vy * t + oy, -margin, lh + 2.0 * margin);
-            let x = wrap(h(i, 11, seed) * (lw + 2.0 * margin) + vx * t + ox, -margin, lw + 2.0 * margin) + amp * (fr * t * std::f32::consts::TAU + ph).sin();
-            let (bx, by) = b.to_px([x as f64, y as f64]);
-            Sprite::new(bx as f32, by as f32, r * s, [color[0], color[1], color[2], opacity * (0.4 + 0.6 * k)], Shape::Soft)
-        })
-        .collect();
-    SpritePlan { sprites, tints: vec![], acc: Acc::Over, post: weather_post(mode, with_orig) }
-}
-
-// ------------------------------------------------------------------ CC Bubbles
-
-/// A CC Bubbles bubble in buffer pixels.
-#[derive(Clone, Copy, Debug)]
-pub struct Bubble {
-    pub x: f32,
-    pub y: f32,
-    pub r: f32,
-    /// Source sample centre (buffer px).
-    pub sx: f32,
-    pub sy: f32,
-}
-
-/// CC Bubbles' bubbles this frame (closed-form in time) for buffer geometry `b`.
-pub fn bubble_list(ctx: &EffectCtx, b: &Buf) -> Vec<Bubble> {
-    let pr = ctx.params;
-    let n = pr.f("bubbleAmount").clamp(0.0, 10_000.0) as u32;
-    let speed = pr.f("bubbleSpeed") as f32;
-    let wamp = pr.f("wobbleAmplitude") as f32;
-    let wfreq = pr.f("wobbleFrequency") as f32;
-    let bsize = pr.f("bubbleSize").max(0.0) as f32;
-    let seed = ctx.seed.wrapping_mul(0x27d4);
-    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
-    let s = b.scale as f32;
-    let t = ctx.time as f32;
-    let base = lw.min(lh) * 0.035 * bsize;
-    (0..n)
-        .map(|i| {
-            let r = base * (0.5 + h(i, 1, seed));
-            let travel = lh + 2.0 * r;
-            let v = speed * lh * 0.3 * (0.6 + 0.8 * h(i, 2, seed));
-            let y = lh + r - (h(i, 3, seed) * travel + v * t).rem_euclid(travel);
-            let x0 = h(i, 4, seed) * lw;
-            let x = x0 + wamp * (r / base.max(1e-3)) * (t * wfreq * std::f32::consts::TAU + h(i, 5, seed) * std::f32::consts::TAU).sin();
-            let (bx, by) = b.to_px([x as f64, y as f64]);
-            let (sx, sy) = b.to_px([x0 as f64, y as f64]);
-            Bubble { x: bx as f32, y: by as f32, r: r * s, sx: sx as f32, sy: sy as f32 }
-        })
-        .collect()
-}
-
-fn bubbles(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let pr = ctx.params;
-    let metal = pr.e("reflectionType") == 1;
-    let shading = pr.e("shadingType");
-    let list = bubble_list(ctx, &b);
-    let src = b.img.clone();
-    let mut out = Image::new(src.width, src.height);
-    raster(
-        &mut out,
-        &list,
-        |q| Some([q.x - q.r - 1.0, q.y - q.r - 1.0, q.x + q.r + 1.0, q.y + q.r + 1.0]),
-        |q, x, y| {
-            let (dx, dy) = ((x - q.x) / q.r.max(0.5), (y - q.y) / q.r.max(0.5));
-            let d2 = dx * dx + dy * dy;
-            let d = d2.sqrt();
-            let cov = aa((1.0 - d) * q.r);
-            if cov <= 0.0 {
-                return None;
-            }
-            // Liquid refracts (inverted, magnified), metal reflects (wide-angle mirror).
-            let k = if metal { 1.6 } else { -0.7 };
-            let nz = (1.0 - d2).max(0.0).sqrt();
-            let p = src.sample_bilinear((q.sx + dx * q.r * k) as f64, (q.sy + dy * q.r * k) as f64);
-            let (c, sa) = unpremul(p);
-            let mut c = if sa <= 0.0 { [0.6, 0.7, 0.8] } else { c };
-            let mut a = cov;
-            match shading {
-                1 => c = c.map(|v| v * 0.7 + 0.3 * (1.0 - nz)),
-                2 => c = c.map(|v| v * (0.5 + 0.5 * nz)),
-                3 => a *= nz.powf(0.5),
-                4 => a *= 1.0 - nz * 0.8,
-                _ => {}
-            }
-            let hl = (1.0 - ((dx + 0.35).powi(2) + (dy + 0.35).powi(2)) / 0.05).max(0.0) * 0.8;
-            let c = c.map(|v| v + hl);
-            Some([c[0] * a, c[1] * a, c[2] * a, a])
-        },
-        Acc::Over,
-    );
-    b.img = out;
-    b
-}
-
-// ------------------------------------------------------------------ CC Drizzle
-
-/// CC Drizzle's live drops this frame (buffer px: centre x, y, ring radius, amplitude);
-/// `None` = no drops yet (the layer passes through).
-pub fn drizzle_drops(ctx: &EffectCtx, b: &Buf) -> Option<Vec<[f32; 4]>> {
-    let pr = ctx.params;
-    let rate = pr.f("dripRate").max(0.0);
-    let life = pr.f("longevity").max(0.01);
-    let spreading = pr.f("spreading") as f32;
-    let height = pr.f("rippleHeight") as f32 / 100.0;
-    let seed = ctx.seed.wrapping_mul(0x165667b1);
-    let t = ctx.time;
-    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
-    let s = b.scale as f32;
-    if rate <= 0.0 || t < 0.0 {
-        return None;
-    }
-    // Drops born at k / rate with hashed positions; alive while younger than the longevity.
-    let k0 = ((t - life) * rate).floor().max(0.0) as u32;
-    let k1 = (t * rate).floor() as u32;
-    let mut drops = Vec::new();
-    for k in k0..=k1 {
-        let born = k as f64 / rate;
-        let age = (t - born) as f32;
-        if age < 0.0 || age as f64 >= life {
-            continue;
-        }
-        let (x, y) = b.to_px([(h(k, 1, seed) * lw) as f64, (h(k, 2, seed) * lh) as f64]);
-        let radius = spreading * age * lh / 400.0 * s;
-        let amp = height * (1.0 - age / life as f32) * (0.6 + 0.4 * h(k, 3, seed));
-        drops.push([x as f32, y as f32, radius, amp]);
-    }
-    Some(drops)
-}
-
-fn drizzle(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let pr = ctx.params;
-    let Some(drops) = drizzle_drops(ctx, &b) else { return b };
-    let rippling = (pr.f("rippling") / 360.0).max(0.05) as f32;
-    let disp = pr.f("displacement") as f32;
-    let li = pr.f("light/lightIntensity") as f32 / 100.0;
-    let lc = pr.color("light/lightColor");
-    let lheight = pr.f("light/lightHeight") as f32 / 100.0;
-    let ldir = (pr.f("light/lightDirection") as f32).to_radians();
-    let ambient = pr.f("shading/ambient") as f32 / 100.0;
-    let diffuse = pr.f("shading/diffuse") as f32 / 100.0;
-    let specular = pr.f("shading/specular") as f32 / 100.0;
-    let rough = pr.f("shading/roughness").max(0.001) as f32;
-    let lh = ctx.layer_size[1] as f32;
-    let s = b.scale as f32;
-    let wavelen = (lh * 0.04 * s).max(2.0) / rippling.clamp(0.25, 4.0);
-    let width = wavelen * (1.0 + rippling * 2.0);
-    let field = |x: f32, y: f32| -> f32 {
-        let mut v = 0.0;
-        for &[dx, dy, r, a] in &drops {
-            let d = ((x - dx).powi(2) + (y - dy).powi(2)).sqrt();
-            let u = (d - r) / width;
-            if u.abs() < 1.0 {
-                let env = 0.5 + 0.5 * (u * std::f32::consts::PI).cos();
-                v += a * env * ((d - r) / wavelen * std::f32::consts::TAU).cos();
-            }
-        }
-        v
-    };
-    let src = b.img.clone();
-    let (ls, lcs) = ldir.sin_cos();
-    let l = {
-        let v = [lcs, ls, lheight.max(0.05)];
-        let n = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt();
-        [v[0] / n, v[1] / n, v[2] / n]
-    };
-    b.img.rows_mut().for_each(|(y, row)| {
-        for (x, px) in row.iter_mut().enumerate() {
-            let (fx, fy) = (x as f32 + 0.5, y as f32 + 0.5);
-            let gx = field(fx + 1.0, fy) - field(fx - 1.0, fy);
-            let gy = field(fx, fy + 1.0) - field(fx, fy - 1.0);
-            if gx == 0.0 && gy == 0.0 {
-                continue;
-            }
-            let p = src.sample_bilinear_clamped((fx - gx * disp * s * 4.0) as f64, (fy - gy * disp * s * 4.0) as f64);
-            let n = {
-                let v = [-gx * 6.0, -gy * 6.0, 1.0];
-                let m = (v[0] * v[0] + v[1] * v[1] + 1.0).sqrt();
-                [v[0] / m, v[1] / m, v[2] / m]
-            };
-            let nl = (n[0] * l[0] + n[1] * l[1] + n[2] * l[2]).max(0.0);
-            let hz = (l[2] + 1.0) * 0.5;
-            let hv = {
-                let v = [l[0] * 0.5, l[1] * 0.5, hz];
-                let m = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt();
-                [v[0] / m, v[1] / m, v[2] / m]
-            };
-            let sp = (n[0] * hv[0] + n[1] * hv[1] + n[2] * hv[2]).max(0.0).powf(1.0 / rough) * specular * li;
-            let shade = 1.0 + (ambient + diffuse * nl - diffuse * l[2]) * li;
-            let a = p[3];
-            *px = [p[0] * shade + sp * lc[0] * a, p[1] * shade + sp * lc[1] * a, p[2] * shade + sp * lc[2] * a, a];
-        }
-    });
-    b
-}
-
-// ------------------------------------------------------------------ CC Star Burst
-
-fn star_burst(ctx: &EffectCtx, b: Buf) -> Buf {
-    let mut plan = star_burst_plan(ctx, &b);
-    plan.resolve(&b.img);
-    plan.finish(b)
-}
-
-fn star_burst_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
-    let pr = ctx.params;
-    let scatter = pr.f("scatter") as f32;
-    let speed = pr.f("speed") as f32;
-    let phase = pr.f("phase") as f32 / 360.0;
-    let spacing = pr.f("gridSpacing").max(1.0) as f32;
-    let size = pr.f("size") as f32 / 100.0;
-    let blend = pr.f("blendWithOriginal") as f32 / 100.0;
-    let seed = ctx.seed.wrapping_mul(0x3c6e);
-    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
-    let s = b.scale as f32;
-    let t = ctx.time as f32;
-    let nx = (lw / spacing).ceil().max(1.0) as u32;
-    let ny = (lh / spacing).ceil().max(1.0) as u32;
-    let (cx, cy) = (lw * 0.5, lh * 0.5);
-    let mut list: Vec<(f32, Sprite, Tint)> = (0..nx * ny)
-        .into_par_iter()
-        .map(|i| {
-            let (gx, gy) = ((i % nx) as f32 * spacing + spacing * 0.5, (i / nx) as f32 * spacing + spacing * 0.5);
-            let (sx, sy) = b.to_px([gx as f64, gy as f64]);
-            // Depth cycles towards the viewer: z in [0, 1), perspective 1 / (1 - 0.9 z).
-            let z = (h(i, 1, seed) + t * speed * 0.25 + phase).rem_euclid(1.0);
-            let persp = 1.0 / (1.0 - 0.9 * z);
-            let jx = hs(i, 2, seed) * scatter * 0.01 * lw * 0.5;
-            let jy = hs(i, 3, seed) * scatter * 0.01 * lh * 0.5;
-            let x = cx + (gx - cx + jx) * persp;
-            let y = cy + (gy - cy + jy) * persp;
-            let (bx, by) = b.to_px([x as f64, y as f64]);
-            let r = spacing * 0.5 * size * persp * s;
-            let fade = (z * 8.0).min(1.0) * ((1.0 - z) * 6.0).min(1.0);
-            // The layer's colour at the grid point (none where it is clear).
-            (z, Sprite::new(bx as f32, by as f32, r, [0.0, 0.0, 0.0, fade], Shape::Disc), Tint::Source { x: sx, y: sy })
-        })
-        .collect();
-    list.sort_by(|a, b| a.0.total_cmp(&b.0));
-    let (sprites, tints) = list.into_iter().map(|(_, s, t)| (s, t)).unzip();
-    SpritePlan { sprites, tints, acc: Acc::Over, post: if blend > 0.0 { Post::Lerp(blend) } else { Post::Replace } }
-}
-
-// ------------------------------------------------------------------ particle engine
-
-/// Steps per second of the stepped particle simulations.
-pub(crate) const SPS: f64 = 60.0;
-
-/// Number of whole steps reached at layer time `t`.
-pub(crate) fn steps_at(t: f64) -> u64 {
-    if t <= 0.0 { 0 } else { (t * SPS + 1e-6).floor() as u64 }
-}
-
-#[derive(Clone, Debug)]
-pub(crate) struct Particle {
-    pub p: [f32; 3],
-    pub v: [f32; 3],
-    pub age: f32,
-    pub life: f32,
-    /// Per-particle random in [0, 1) (size variation, colour jitter…).
-    pub rnd: f32,
-    pub id: u32,
-}
-
-#[derive(Clone, Debug, Default)]
-pub(crate) struct PState {
-    pub parts: Vec<Particle>,
-    pub carry: f64,
-    pub next_id: u32,
-}
-
-/// Physics configuration (world units; y down).
-#[derive(Clone, Copy, Debug)]
-pub(crate) struct Phys {
-    /// Particles per second.
-    pub rate: f64,
-    pub life: f32,
-    pub producer: [f32; 3],
-    pub radius: [f32; 3],
-    pub anim: u32,
-    pub speed: f32,
-    pub gravity: [f32; 3],
-    pub resistance: f32,
-    pub axis: [f32; 3],
-    pub extra: f32,
-    pub extra_angle: f32,
-    pub seed: u32,
-    pub max: usize,
-    /// 2D systems keep z = 0.
-    pub flat: bool,
-}
-
-pub(crate) const PW_ANIMS: &[&str] =
-    &["Explosive", "Direction Axis", "Cone Axis", "Viscouse", "Twirly", "Vortex", "Fire", "Jet Sideways", "Fractal Omni", "Fractal Uni"];
-
-fn norm3(v: [f32; 3]) -> [f32; 3] {
-    let l = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt();
-    if l > 1e-9 { [v[0] / l, v[1] / l, v[2] / l] } else { [0.0, -1.0, 0.0] }
-}
-
-fn rand_dir(i: u32, k: u32, seed: u32, flat: bool) -> [f32; 3] {
-    if flat {
-        let a = h(i, k, seed) * std::f32::consts::TAU;
-        return [a.cos(), a.sin(), 0.0];
-    }
-    let z = hs(i, k, seed);
-    let a = h(i, k + 1, seed) * std::f32::consts::TAU;
-    let r = (1.0 - z * z).max(0.0).sqrt();
-    [r * a.cos(), r * a.sin(), z]
-}
-
-impl Phys {
-    fn spawn(&self, id: u32) -> Particle {
-        let seed = self.seed;
-        let mut p = [0.0f32; 3];
-        // Uniform in the producer ellipsoid.
-        let u = rand_dir(id, 1, seed, self.flat);
-        let rr = h(id, 3, seed).powf(if self.flat { 0.5 } else { 1.0 / 3.0 });
-        for k in 0..3 {
-            p[k] = self.producer[k] + u[k] * self.radius[k] * rr;
-        }
-        if self.flat {
-            p[2] = 0.0;
-        }
-        let ax = norm3(self.axis);
-        let jitter = rand_dir(id, 5, seed, self.flat);
-        let dir = match self.anim {
-            1 | 9 => norm3([ax[0] + jitter[0] * 0.08, ax[1] + jitter[1] * 0.08, ax[2] + jitter[2] * 0.08]),
-            2 => {
-                let k = (self.extra_angle.to_radians() * 0.5).tan().abs().min(20.0);
-                norm3([ax[0] + jitter[0] * k * h(id, 8, seed), ax[1] + jitter[1] * k * h(id, 8, seed), ax[2] + jitter[2] * k * h(id, 8, seed)])
-            }
-            5 => [jitter[0], 0.0, if self.flat { 0.0 } else { jitter[2] }],
-            6 => norm3([jitter[0] * 0.25, -1.0, jitter[2] * 0.25]),
-            7 => norm3([1.0, jitter[1] * 0.05, jitter[2] * 0.05]),
-            _ => jitter,
-        };
-        let sp = self.speed * (0.5 + 0.5 * h(id, 9, seed));
-        let mut v = [dir[0] * sp, dir[1] * sp, dir[2] * sp];
-        if self.flat {
-            v[2] = 0.0;
-        }
-        let life = self.life * (0.8 + 0.4 * h(id, 10, seed));
-        Particle { p, v, age: 0.0, life, rnd: h(id, 11, seed), id }
-    }
-
-    pub(crate) fn step(&self, st: &mut PState, step: u64) {
-        let dt = (1.0 / SPS) as f32;
-        let t = step as f32 * dt;
-        let mut drag = self.resistance;
-        if self.anim == 3 {
-            drag += 3.0 * self.extra.max(0.1);
-        }
-        let damp = (-drag * dt).exp();
-        let seed = self.seed;
-        st.parts.par_iter_mut().for_each(|q| {
-            let mut a = self.gravity;
-            match self.anim {
-                4 => {
-                    // Twirly: swirl around the vertical axis through the producer.
-                    let (dx, dz) = (q.p[0] - self.producer[0], q.p[2] - self.producer[2]);
-                    let k = 4.0 * self.extra;
-                    a[0] += -dz * k;
-                    a[2] += dx * k;
-                    if self.flat {
-                        let dy = q.p[1] - self.producer[1];
-                        a[0] += -dy * k;
-                        a[1] += dx * k;
-                    }
-                }
-                5 => {
-                    // Vortex: strong tangential + inward pull.
-                    let (dx, dy) = (q.p[0] - self.producer[0], q.p[1] - self.producer[1]);
-                    let k = 6.0 * self.extra;
-                    a[0] += -dy * k - dx * 2.0;
-                    a[1] += dx * k - dy * 2.0;
-                }
-                6 => {
-                    // Fire: buoyant, flickering turbulence.
-                    let n = value_noise(q.p[0] * 8.0, q.p[1] * 8.0, t * 3.0, seed) - 0.5;
-                    a[0] += n * 4.0 * self.extra;
-                    a[1] -= self.gravity[1] * 1.5 + 0.3 * self.extra;
-                }
-                8 | 9 => {
-                    let f = 6.0 * self.extra;
-                    a[0] += (value_noise(q.p[0] * 5.0, q.p[1] * 5.0, q.p[2] * 5.0 + t, seed) - 0.5) * f;
-                    a[1] += (value_noise(q.p[0] * 5.0 + 17.0, q.p[1] * 5.0, q.p[2] * 5.0 + t, seed) - 0.5) * f;
-                    if !self.flat {
-                        a[2] += (value_noise(q.p[0] * 5.0, q.p[1] * 5.0 + 31.0, q.p[2] * 5.0 + t, seed) - 0.5) * f;
-                    }
-                }
-                _ => {}
-            }
-            for k in 0..3 {
-                q.v[k] = (q.v[k] + a[k] * dt) * damp;
-                q.p[k] += q.v[k] * dt;
-            }
-            if self.flat {
-                q.p[2] = 0.0;
-                q.v[2] = 0.0;
-            }
-            q.age += dt;
-        });
-        st.parts.retain(|q| q.age < q.life);
-        st.carry += self.rate / SPS;
-        let n = st.carry.floor() as u32;
-        st.carry -= n as f64;
-        for _ in 0..n {
-            if st.parts.len() >= self.max {
-                break;
-            }
-            let id = st.next_id;
-            st.next_id = st.next_id.wrapping_add(1);
-            // Sub-step birth offset keeps continuous streams smooth.
-            let mut q = self.spawn(id);
-            let frac = h(id, 12, seed) * dt;
-            for k in 0..3 {
-                q.p[k] += q.v[k] * frac;
-            }
-            q.age = frac;
-            st.parts.push(q);
-        }
-    }
-}
-
-impl Phys {
-    /// The backend description (per-step and per-spawn constants evaluated here, in f32).
-    pub(crate) fn desc(&self) -> crate::psim::EngineDesc {
-        let mut drag = self.resistance;
-        if self.anim == 3 {
-            drag += 3.0 * self.extra.max(0.1);
-        }
-        let dt = (1.0 / SPS) as f32;
-        crate::psim::EngineDesc {
-            life: self.life,
-            producer: self.producer,
-            radius: self.radius,
-            anim: self.anim,
-            speed: self.speed,
-            gravity: self.gravity,
-            axis: norm3(self.axis),
-            extra: self.extra,
-            cone: (self.extra_angle.to_radians() * 0.5).tan().abs().min(20.0),
-            damp: (-drag * dt).exp(),
-            seed: self.seed,
-            flat: self.flat,
-        }
-    }
-}
-
-/// The state at layer time `ctx.time` from the host's particle backend (GPU particles), or
-/// `None` (simulate on the CPU).
-fn accelerated(ctx: &EffectCtx, key: u64, phys: &Phys) -> Option<std::sync::Arc<PState>> {
-    let backend = ctx.env.host?.particles()?;
-    let steps = steps_at(ctx.time);
-    let births = crate::psim::births(phys.rate, steps, phys.max)?;
-    let req = crate::psim::SimRequest { key, steps, births: &births, system: crate::psim::ParticleSystem::Engine(phys.desc()) };
-    let parts = backend.simulate(&req)?;
-    Some(std::sync::Arc::new(PState {
-        parts: parts.into_iter().map(|q| Particle { p: q.p, v: q.v, age: q.age, life: q.life, rnd: q.rnd, id: q.id }).collect(),
-        carry: 0.0,
-        next_id: births.len() as u32,
-    }))
-}
-
-/// The live particles of a stepped particle effect (`ec.sim.ccparticleworld`,
-/// `ec.sim.ccparticlesystems2`) at `ctx.time`: from the host's particle backend when it has
-/// one (GPU particles), else from the CPU simulation. For comparing the two.
-pub fn particle_state(id: &str, ctx: &EffectCtx) -> Option<Vec<crate::psim::SimParticle>> {
-    let (phys, cache, salt) = match id {
-        "ec.sim.ccparticleworld" => (pw_phys(ctx), &PW_CACHE, 1),
-        "ec.sim.ccparticlesystems2" => (ps2_phys(ctx), &PS2_CACHE, 2),
-        _ => return None,
-    };
-    let key = sim_key(ctx, salt);
-    let st = accelerated(ctx, key, &phys).unwrap_or_else(|| simulate(cache, key, ctx.time, &phys));
-    Some(st.parts.iter().map(|q| crate::psim::SimParticle { p: q.p, v: q.v, age: q.age, life: q.life, rnd: q.rnd, id: q.id }).collect())
-}
-
-/// The simulation cache key of a stepped particle effect: every parameter but CC Particle World's
-/// Effect Camera, which only changes how the particles are seen (animating it doesn't restart
-/// the simulation).
-fn sim_key(ctx: &EffectCtx, salt: u64) -> u64 {
-    params_key_except(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, salt, &[PW_EFFECT_CAMERA])
-}
-
-/// Run a particle system to layer time `t` through `cache`.
-pub(crate) fn simulate(cache: &SimCache<PState>, key: u64, t: f64, phys: &Phys) -> std::sync::Arc<PState> {
-    cache.run(key, steps_at(t), PState::default, |st, i| phys.step(st, i))
-}
-
-pub(crate) const PARTICLE_TYPES: &[&str] =
-    &["Line", "Shaded Sphere", "Faded Sphere", "Bubble", "Star", "Motion Polygon", "Tri-Polygon", "Cube", "Textured Square"];
-
-/// Colour/size/opacity of a particle at its age.
-fn particle_look(q: &Particle, birth: [f32; 4], death: [f32; 4], bsize: f32, dsize: f32, svar: f32, max_op: f32) -> ([f32; 4], f32) {
-    let u = (q.age / q.life.max(1e-4)).clamp(0.0, 1.0);
-    let size = (bsize + (dsize - bsize) * u) * (1.0 + svar * (q.rnd * 2.0 - 1.0));
-    let fade = (u * 20.0).min(1.0) * ((1.0 - u) * 5.0).min(1.0);
-    let c = [birth[0] + (death[0] - birth[0]) * u, birth[1] + (death[1] - birth[1]) * u, birth[2] + (death[2] - birth[2]) * u, max_op * fade];
-    (c, size.max(0.0))
-}
-
-fn type_sprite(kind: u32, x: f32, y: f32, r: f32, c: [f32; 4], vx: f32, vy: f32, rot: f32) -> Sprite {
-    let vl = (vx * vx + vy * vy).sqrt().max(1e-6);
-    let shape = match kind {
-        0 => Shape::Line { dx: -vx / vl * r * 2.0, dy: -vy / vl * r * 2.0 },
-        1 => Shape::Sphere,
-        2 => Shape::Faded,
-        3 => Shape::Bubble,
-        4 => Shape::Star,
-        5 => Shape::Line { dx: -vx * 0.05, dy: -vy * 0.05 },
-        6 => Shape::Tri,
-        _ => Shape::Square,
-    };
-    let rr = match kind {
-        0 => (r * 0.08).max(0.5),
-        5 => r * 0.5,
-        _ => r,
-    };
-    Sprite { x, y, r: rr, c, shape, rot }
-}
-
-// ------------------------------------------------------------------ CC Particle World
-
-static PW_CACHE: SimCache<PState> = SimCache::new(6);
-
-/// CC Particle World's physics.
-fn pw_phys(ctx: &EffectCtx) -> Phys {
-    let pr = ctx.params;
-    Phys {
-        rate: pr.f("birthRate").max(0.0) * 120.0,
-        life: pr.f("longevity").max(0.0) as f32,
-        producer: [pr.f("producer/producerX") as f32, pr.f("producer/producerY") as f32, pr.f("producer/producerZ") as f32],
-        radius: [pr.f("producer/radiusX").max(0.0) as f32, pr.f("producer/radiusY").max(0.0) as f32, pr.f("producer/radiusZ").max(0.0) as f32],
-        anim: pr.e("physics/animation"),
-        speed: pr.f("physics/velocity") as f32 * 0.5,
-        gravity: {
-            let g = pr.f("physics/gravity") as f32;
-            let gv =
-                [pr.f("physics/gravityVector/gravityX") as f32, pr.f("physics/gravityVector/gravityY") as f32, pr.f("physics/gravityVector/gravityZ") as f32];
-            [gv[0] * g, gv[1] * g, gv[2] * g]
-        },
-        resistance: pr.f("physics/resistance").max(0.0) as f32,
-        axis: [pr.f("physics/directionAxis/axisX") as f32, pr.f("physics/directionAxis/axisY") as f32, pr.f("physics/directionAxis/axisZ") as f32],
-        extra: pr.f("physics/extra") as f32,
-        extra_angle: pr.f("physics/extraAngle") as f32,
-        seed: (pr.f("extras/randomSeed") as u32).wrapping_mul(0x9e3779b9) ^ ctx.seed,
-        max: 40_000,
-        flat: false,
-    }
-}
-
-fn particle_world(ctx: &EffectCtx, b: Buf) -> Buf {
-    // #1195: with the comp's motion-blur shutter open, particles draw as motion trails: the
-    // sprite fields of samples across the shutter are averaged, as Transform averages its
-    // matrix samples. (The GPU compositor runs this case on the CPU: catalog::gpu_supported.)
-    if let Some((angle, phase, n)) = ctx.env.shutter.filter(|(a, _, _)| *a > 0.0) {
-        let n = (n.clamp(2, 64) as usize).max(2);
-        let fd = 1.0 / ctx.fps().max(0.001);
-        let mut acc = Image::new(b.img.width, b.img.height);
-        let mut post: Option<Post> = None;
-        for k in 0..n {
-            let t = ctx.time + (phase + angle * k as f64 / (n - 1) as f64) / 360.0 * fd;
-            let sub = EffectCtx { params: ctx.params, time: t, layer_size: ctx.layer_size, seed: ctx.seed, adjustment: ctx.adjustment, env: ctx.env };
-            if let Some(plan) = particle_world_plan(&sub, &b) {
-                let fx = splat(b.img.width, b.img.height, &plan.sprites, plan.acc);
-                acc.data.iter_mut().zip(&fx.data).for_each(|(a, o)| (0..4).for_each(|c| a[c] += o[c]));
-                post.get_or_insert(plan.post);
-            }
-        }
-        acc.data.iter_mut().for_each(|p| p.iter_mut().for_each(|v| *v /= n as f32));
-        return match post {
-            Some(p) => p.apply(b, acc),
-            None => b,
-        };
-    }
-    match particle_world_plan(ctx, &b) {
-        Some(plan) => plan.finish(b),
-        None => b,
-    }
-}
-
-/// CC Particle World's Extras ▸ Effect Camera parameters (id prefix).
-const PW_EFFECT_CAMERA: &str = "extras/effectCamera/";
-/// Effect Camera ▸ FOV's default (degrees).
-const PW_FOV: f64 = 50.0;
-
-/// What CC Particle World sees its particles through.
-enum PwCamera {
-    /// Extras ▸ Effect Camera, in world units (layer widths): `dist` from the world origin (the
-    /// layer centre) along −z, the world turned by `rot` (`None` = not turned) about the origin,
-    /// `focal` the scale at unit depth; particles nearer than `near` aren't drawn.
-    Effect { rot: Option<[[f32; 3]; 3]>, dist: f32, focal: f32, near: f32 },
-    /// The comp's active camera layer, on buffer-world points (After Effects then ignores the
-    /// Effect Camera).
-    Comp(crate::card3d::Proj),
-}
-
-/// A particle as the camera sees it: depth (larger is farther), buffer pixel, size scale `k`
-/// (buffer pixels per world unit = `k · layer width · buffer scale`) and velocity in world units
-/// on screen (× the same factor for buffer pixels).
-struct PwSeen {
-    depth: f32,
-    x: f32,
-    y: f32,
-    k: f32,
-    v: [f32; 2],
-}
-
-impl PwCamera {
-    fn new(ctx: &EffectCtx, b: &Buf) -> PwCamera {
-        let [lw, lh] = ctx.layer_size;
-        if let Some(cam) = ctx.env.host.and_then(|h| h.comp_scene()).filter(|sc| sc.camera_layer).and_then(|sc| sc.camera) {
-            let c = [b.offset[0] + lw * 0.5 * b.scale, b.offset[1] + lh * 0.5 * b.scale];
-            return PwCamera::Comp(crate::card3d::comp_proj(&cam, c, b));
-        }
-        let f = |id: &str, d: f64| ctx.params.get(&format!("{PW_EFFECT_CAMERA}{id}")).map(Value::as_f64).filter(|v| v.is_finite()).unwrap_or(d);
-        // The camera keeps the origin's plane at the scale Distance gives it as FOV changes
-        // (moving in for a wider view), so FOV sets how strong the perspective is. Distance 2
-        // shows the origin's plane at the layer's own scale.
-        let half = |fov: f64| (fov.clamp(1.0, 179.0).to_radians() * 0.5).tan();
-        let zoom = half(PW_FOV) / half(f("fov", PW_FOV));
-        let dist = f("distance", 2.0).max(0.01) * zoom;
-        let a = [f("rotationX", 0.0), f("rotationY", 0.0), f("rotationZ", 0.0)];
-        let rot = (a != [0.0; 3]).then(|| {
-            let r = crate::card3d::rot_ordered(a[0].to_radians(), a[1].to_radians(), a[2].to_radians(), 0);
-            r.map(|row| row.map(|v| v as f32))
-        });
-        PwCamera::Effect { rot, dist: dist as f32, focal: (2.0 * zoom) as f32, near: (0.025 * dist) as f32 }
-    }
-
-    /// How the camera sees world point `p` moving at `v`; `None` behind or too close to it.
-    fn see(&self, p: [f32; 3], v: [f32; 3], lw: f32, lh: f32, b: &Buf) -> Option<PwSeen> {
-        match self {
-            PwCamera::Effect { rot, dist, focal, near } => {
-                let turn = |r: &[[f32; 3]; 3], q: [f32; 3]| r.map(|row| row[0] * q[0] + row[1] * q[1] + row[2] * q[2]);
-                let (p, v) = match rot {
-                    Some(r) => (turn(r, p), turn(r, v)),
-                    None => (p, v),
-                };
-                let zc = dist + p[2];
-                if zc.is_nan() || zc <= *near {
-                    return None;
-                }
-                let k = focal / zc;
-                let (x, y) = b.to_px([(lw * 0.5 + p[0] * lw * k) as f64, (lh * 0.5 + p[1] * lw * k) as f64]);
-                Some(PwSeen { depth: zc, x: x as f32, y: y as f32, k, v: [v[0], v[1]] })
-            }
-            PwCamera::Comp(proj) => {
-                let (s, lw, lh) = (b.scale, lw as f64, lh as f64);
-                let u = lw * s;
-                let at = [b.offset[0] + lw * 0.5 * s + p[0] as f64 * u, b.offset[1] + lh * 0.5 * s + p[1] as f64 * u, p[2] as f64 * u];
-                let seen = proj.view(at, [v[0] as f64, v[1] as f64, v[2] as f64])?;
-                let k = seen.scale;
-                Some(PwSeen {
-                    depth: seen.depth as f32,
-                    x: seen.at[0] as f32,
-                    y: seen.at[1] as f32,
-                    k: k as f32,
-                    v: [(seen.vel[0] / k) as f32, (seen.vel[1] / k) as f32],
-                })
-            }
-        }
-    }
-}
-
-/// CC Particle World's sprites (far to near), `None` before anything is born.
-fn particle_world_plan(ctx: &EffectCtx, b: &Buf) -> Option<SpritePlan> {
-    let pr = ctx.params;
-    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
-    let phys = pw_phys(ctx);
-    if phys.rate <= 0.0 && ctx.time <= 0.0 {
-        return None;
-    }
-    let key = sim_key(ctx, 1);
-    let st = accelerated(ctx, key, &phys).unwrap_or_else(|| simulate(&PW_CACHE, key, ctx.time, &phys));
-    let kind = pr.e("particle/particleType");
-    let birth = pr.color("particle/birthColor");
-    let death = pr.color("particle/deathColor");
-    let (bs, ds) = (pr.f("particle/birthSize") as f32, pr.f("particle/deathSize") as f32);
-    let svar = pr.f("particle/sizeVariation") as f32 / 100.0;
-    let max_op = pr.f("particle/maxOpacity") as f32 / 100.0;
-    let s = b.scale as f32;
-    let cam = PwCamera::new(ctx, b);
-    let mut list: Vec<(f32, Sprite)> = st
-        .parts
-        .par_iter()
-        .filter_map(|q| {
-            let PwSeen { depth, x, y, k, v } = cam.see(q.p, q.v, lw, lh, b)?;
-            let (c, size) = particle_look(q, birth, death, bs, ds, svar, max_op);
-            let r = size * 0.5 * lw * k * s * 0.25;
-            let sp = type_sprite(kind, x, y, r, c, v[0] * lw * k * s, v[1] * lw * k * s, (q.id % 628) as f32 * 0.01 + q.age * 2.0);
-            Some((depth, sp))
-        })
-        .collect();
-    list.sort_by(|a, b| b.0.total_cmp(&a.0));
-    let sprites: Vec<Sprite> = list.into_iter().map(|(_, s)| s).collect();
-    Some(particle_sprites(sprites, pr.e("particle/transferMode")))
-}
-
-/// The CC particle systems' sprites with their Transfer Mode (Composite, Screen, Add, Black
-/// Background).
-fn particle_sprites(sprites: Vec<Sprite>, mode: u32) -> SpritePlan {
-    // The particles replace the layer (After Effects shows no trace of the source in any
-    // Transfer Mode, which sets how the particles meet each other).
-    SpritePlan { sprites, tints: vec![], acc: if mode == 2 { Acc::Add } else { Acc::Over }, post: Post::Replace }
-}
-
-// ------------------------------------------------------------------ CC Particle Systems II
-
-static PS2_CACHE: SimCache<PState> = SimCache::new(6);
-
-/// CC Particle Systems II's physics.
-fn ps2_phys(ctx: &EffectCtx) -> Phys {
-    let pr = ctx.params;
-    let lh = ctx.layer_size[1] as f32;
-    let unit = lh.max(1.0);
-    let pos = pr.v2("producer/position");
-    let dir = (pr.f("physics/direction") as f32).to_radians();
-    Phys {
-        rate: pr.f("birthRate").max(0.0) * 60.0,
-        life: pr.f("longevity").max(0.0) as f32,
-        producer: [pos[0] as f32 / unit, pos[1] as f32 / unit, 0.0],
-        radius: [pr.f("producer/radiusX").max(0.0) as f32 / unit, pr.f("producer/radiusY").max(0.0) as f32 / unit, 0.0],
-        anim: [0u32, 1, 2, 3, 4, 5, 6, 7, 8, 9][pr.e("physics/animation").min(9) as usize],
-        speed: pr.f("physics/velocity") as f32 * 0.25,
-        gravity: [0.0, pr.f("physics/gravity") as f32 * 0.5, 0.0],
-        resistance: pr.f("physics/resistance").max(0.0) as f32,
-        // AE angles: 0° = up, clockwise.
-        axis: [dir.sin(), -dir.cos(), 0.0],
-        extra: pr.f("physics/extra") as f32,
-        extra_angle: 45.0 * pr.f("physics/extra") as f32,
-        seed: (pr.f("randomSeed") as u32).wrapping_mul(0x85ebca6b) ^ ctx.seed,
-        max: 40_000,
-        flat: true,
-    }
-}
-
-fn particle_systems2(ctx: &EffectCtx, b: Buf) -> Buf {
-    particle_systems2_plan(ctx, &b).finish(b)
-}
-
-/// CC Particle Systems II's sprites.
-fn particle_systems2_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
-    let pr = ctx.params;
-    let lh = ctx.layer_size[1] as f32;
-    let unit = lh.max(1.0);
-    let phys = ps2_phys(ctx);
-    let key = sim_key(ctx, 2);
-    let st = accelerated(ctx, key, &phys).unwrap_or_else(|| simulate(&PS2_CACHE, key, ctx.time, &phys));
-    let kind = pr.e("particle/particleType");
-    let birth = pr.color("particle/birthColor");
-    let death = pr.color("particle/deathColor");
-    let (bs, ds) = (pr.f("particle/birthSize") as f32, pr.f("particle/deathSize") as f32);
-    let svar = pr.f("particle/sizeVariation") as f32 / 100.0;
-    let max_op = pr.f("particle/maxOpacity") as f32 / 100.0;
-    let s = b.scale as f32;
-    let sprites: Vec<Sprite> = st
-        .parts
-        .iter()
-        .map(|q| {
-            let (bx, by) = b.to_px([(q.p[0] * unit) as f64, (q.p[1] * unit) as f64]);
-            let (c, size) = particle_look(q, birth, death, bs, ds, svar, max_op);
-            let r = size * unit * 0.02 * s;
-            type_sprite(kind, bx as f32, by as f32, r, c, q.v[0] * unit * s, q.v[1] * unit * s, (q.id % 628) as f32 * 0.01 + q.age * 2.0)
-        })
-        .collect();
-    particle_sprites(sprites, pr.e("particle/transferMode"))
-}
-
-// ------------------------------------------------------------------ CC Mr. Mercury
-
-static MERCURY_CACHE: SimCache<PState> = SimCache::new(6);
-
-/// A CC Mr. Mercury blob (buffer px).
-#[derive(Clone, Copy, Debug)]
-pub struct Blob {
-    pub x: f32,
-    pub y: f32,
-    pub r: f32,
-}
-
-/// CC Mr. Mercury's blobs this frame, from its particle simulation (for buffer geometry `b`).
-pub fn mercury_blobs(ctx: &EffectCtx, b: &Buf) -> Vec<Blob> {
-    let pr = ctx.params;
-    let lh = ctx.layer_size[1] as f32;
-    let unit = lh.max(1.0);
-    let pos = pr.v2("producer");
-    let dir = (pr.f("direction") as f32).to_radians();
-    let phys = Phys {
-        rate: pr.f("birthRate").max(0.0) * 10.0,
-        life: pr.f("longevity").max(0.0) as f32,
-        producer: [pos[0] as f32 / unit, pos[1] as f32 / unit, 0.0],
-        radius: [pr.f("radiusX").max(0.0) as f32 / unit, pr.f("radiusY").max(0.0) as f32 / unit, 0.0],
-        anim: [0u32, 1, 2, 3, 4, 5, 6, 7, 8, 9][pr.e("animation").min(9) as usize],
-        speed: pr.f("velocity") as f32 * 0.3,
-        gravity: [0.0, pr.f("gravity") as f32 * 0.5, 0.0],
-        resistance: pr.f("resistance").max(0.0) as f32,
-        axis: [dir.sin(), -dir.cos(), 0.0],
-        extra: pr.f("extra") as f32,
-        extra_angle: 45.0 * pr.f("extra") as f32,
-        seed: ctx.seed.wrapping_mul(0xc2b2ae35),
-        max: 4_000,
-        flat: true,
-    };
-    let st = simulate(&MERCURY_CACHE, params_key(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, 3), ctx.time, &phys);
-    let (bs, ds) = (pr.f("blobBirthSize") as f32, pr.f("blobDeathSize") as f32);
-    let s = b.scale as f32;
-    st.parts
-        .iter()
-        .map(|q| {
-            let u = (q.age / q.life.max(1e-4)).clamp(0.0, 1.0);
-            let size = bs + (ds - bs) * u;
-            let (bx, by) = b.to_px([(q.p[0] * unit) as f64, (q.p[1] * unit) as f64]);
-            Blob { x: bx as f32, y: by as f32, r: (size * unit * 0.08 * s).max(0.0) }
-        })
-        .filter(|q| q.r > 0.1)
-        .collect()
-}
-
-fn mr_mercury(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let pr = ctx.params;
-    let blobs = mercury_blobs(ctx, &b);
-    let influence = pr.f("blobInfluence") as f32 / 100.0;
-    let s = b.scale as f32;
-    let (w, hh) = (b.img.width, b.img.height);
-    // Field and gradient accumulate additively: [f, gx, gy, _].
-    let mut field = Image::new(w, hh);
-    let infl = 1.0 + influence;
-    raster(
-        &mut field,
-        &blobs,
-        |q| {
-            let e = q.r * 2.0 * infl;
-            Some([q.x - e, q.y - e, q.x + e, q.y + e])
-        },
-        |q, x, y| {
-            let (dx, dy) = (x - q.x, y - q.y);
-            let rr = q.r * 2.0 * infl;
-            let d2 = (dx * dx + dy * dy) / (rr * rr);
-            if d2 >= 1.0 {
-                return None;
-            }
-            let k = 1.0 - d2;
-            let f = k * k * k;
-            let g = -6.0 * k * k / (rr * rr);
-            Some([f, g * dx, g * dy, 0.0])
-        },
-        Acc::Add,
-    );
-    let thr = 0.35f32;
-    let ambient = pr.f("shading/ambient") as f32 / 100.0;
-    let diffuse = pr.f("shading/diffuse") as f32 / 100.0;
-    let specular = pr.f("shading/specular") as f32 / 100.0;
-    let rough = pr.f("shading/roughness").max(0.001) as f32;
-    let metal = pr.f("shading/metal") as f32 / 100.0;
-    let li = pr.f("light/lightIntensity") as f32 / 100.0;
-    let lc = pr.color("light/lightColor");
-    let ldir = (pr.f("light/lightDirection") as f32).to_radians();
-    let lheight = pr.f("light/lightHeight") as f32 / 100.0;
-    let l = norm3([ldir.sin(), -ldir.cos(), lheight.max(0.05)]);
-    let src = b.img.clone();
-    let mut out = Image::new(w, hh);
-    out.rows_mut().for_each(|(y, row)| {
-        for (x, px) in row.iter_mut().enumerate() {
-            let fv = field.data[y * w as usize + x];
-            let f = fv[0];
-            if f <= thr * 0.8 {
-                continue;
-            }
-            let cov = ((f - thr * 0.8) / (thr * 0.4)).clamp(0.0, 1.0);
-            let n = norm3([fv[1] * 3.0, fv[2] * 3.0, 1.0 / (1.0 + f)]);
-            // Refract the layer through the blob.
-            let sp = src.sample_bilinear_clamped(x as f64 + 0.5 - n[0] as f64 * 12.0 * s as f64, y as f64 + 0.5 - n[1] as f64 * 12.0 * s as f64);
-            let (c, sa) = unpremul(sp);
-            let base = if sa > 0.0 { c } else { [0.7, 0.7, 0.75] };
-            let nl = (n[0] * l[0] + n[1] * l[1] + n[2] * l[2]).max(0.0);
-            let hv = norm3([l[0], l[1], l[2] + 1.0]);
-            let spec = (n[0] * hv[0] + n[1] * hv[1] + n[2] * hv[2]).max(0.0).powf(1.0 / rough) * specular * li;
-            let shade = ambient + diffuse * nl * li;
-            let cc: [f32; 3] = std::array::from_fn(|k| base[k] * shade + spec * (lc[k] * (1.0 - metal) + base[k] * metal));
-            *px = [cc[0] * cov, cc[1] * cov, cc[2] * cov, cov];
-        }
-    });
-    b.img = out;
-    b
-}
-
-// ------------------------------------------------------------------ specs
-
-pub fn specs() -> Vec<EffectSpec> {
-    let transfer = || popup(&["Composite", "Lighten"]);
-    vec![
-        spec(
-            "ec.sim.ccrainfall",
-            "CC Rainfall",
-            vec![
-                p("drops", "Drops", num(5000.0), slider(0.0, 100_000.0, 0.0, 20_000.0, 0)),
-                p("size", "Size", num(1.0), slider(0.0, 50.0, 0.0, 10.0, 2)),
-                p("sceneDepth", "Scene Depth", num(5000.0), slider(0.0, 20_000.0, 0.0, 10_000.0, 0)),
-                p("speed", "Speed", num(4000.0), slider(0.0, 20_000.0, 0.0, 10_000.0, 0)),
-                p("wind", "Wind", num(0.0), slider(-10_000.0, 10_000.0, -2000.0, 2000.0, 1)),
-                p("windVariation", "Variation % (Wind)", num(0.0), pct()),
-                p("spread", "Spread", num(0.0), slider(0.0, 1000.0, 0.0, 100.0, 1)),
-                p("color", "Color", col(0.8, 0.8, 0.8), ParamUi::Color),
-                p("opacity", "Opacity", num(25.0), pct()),
-                p("transferMode", "Transfer Mode", Value::Enum(1), transfer()),
-                p("compositeWithOriginal", "Composite With Original", Value::Bool(true), ParamUi::Checkbox),
-                p("extras/appearance", "Appearance", Value::Enum(0), popup(&["Refracting", "Soft Solid"])),
-                p("extras/offset", "Offset", pt(0.5, 0.5), ParamUi::Point),
-                p("extras/randomSeed", "Random Seed", num(0.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
-            ],
-            rainfall,
-        ),
-        spec(
-            "ec.sim.ccsnowfall",
-            "CC Snowfall",
-            vec![
-                p("flakes", "Flakes", num(10_000.0), slider(0.0, 200_000.0, 0.0, 50_000.0, 0)),
-                p("size", "Size", num(3.0), slider(0.0, 50.0, 0.0, 20.0, 2)),
-                p("sizeVariation", "Variation % (Size)", num(50.0), pct()),
-                p("sceneDepth", "Scene Depth", num(5000.0), slider(0.0, 20_000.0, 0.0, 10_000.0, 0)),
-                p("speed", "Speed", num(100.0), slider(0.0, 5000.0, 0.0, 1000.0, 1)),
-                p("speedVariation", "Variation % (Speed)", num(50.0), pct()),
-                p("wind", "Wind", num(25.0), slider(-5000.0, 5000.0, -500.0, 500.0, 1)),
-                p("windVariation", "Variation % (Wind)", num(50.0), pct()),
-                p("spread", "Spread", num(0.0), slider(0.0, 1000.0, 0.0, 100.0, 1)),
-                p("wiggle/wiggleAmount", "Amount", num(2.0), slider(0.0, 100.0, 0.0, 20.0, 2)),
-                p("wiggle/wiggleAmountVariation", "Variation % (Amount)", num(50.0), pct()),
-                p("wiggle/wiggleFrequency", "Frequency", num(1.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
-                p("wiggle/wiggleFrequencyVariation", "Variation % (Frequency)", num(50.0), pct()),
-                p("color", "Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("opacity", "Opacity", num(100.0), pct()),
-                p("transferMode", "Transfer Mode", Value::Enum(0), transfer()),
-                p("compositeWithOriginal", "Composite With Original", Value::Bool(true), ParamUi::Checkbox),
-                p("extras/offset", "Offset", pt(0.5, 0.5), ParamUi::Point),
-                p("extras/randomSeed", "Random Seed", num(0.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
-            ],
-            snowfall,
-        ),
-        spec(
-            "ec.sim.ccbubbles",
-            "CC Bubbles",
-            vec![
-                p("bubbleAmount", "Bubble Amount", num(100.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
-                p("bubbleSpeed", "Bubble Speed", num(0.5), slider(-10.0, 10.0, -2.0, 2.0, 2)),
-                p("wobbleAmplitude", "Wobble Amplitude", num(5.0), slider(0.0, 500.0, 0.0, 100.0, 1)),
-                p("wobbleFrequency", "Wobble Frequency", num(1.0), slider(0.0, 50.0, 0.0, 10.0, 2)),
-                p("bubbleSize", "Bubble Size", num(1.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
-                p("reflectionType", "Reflection Type", Value::Enum(0), popup(&["Liquid", "Metal"])),
-                p("shadingType", "Shading Type", Value::Enum(0), popup(&["None", "Lighten", "Darken", "Fade Inwards", "Fade Outwards"])),
-            ],
-            bubbles,
-        ),
-        spec(
-            "ec.sim.ccdrizzle",
-            "CC Drizzle",
-            vec![
-                p("dripRate", "Drip Rate", num(10.0), slider(0.0, 200.0, 0.0, 50.0, 2)),
-                p("longevity", "Longevity (sec)", num(1.0), slider(0.0, 30.0, 0.0, 5.0, 2)),
-                p("rippling", "Rippling", num(360.0), ParamUi::Angle),
-                p("displacement", "Displacement", num(5.0), slider(0.0, 100.0, 0.0, 30.0, 2)),
-                p("rippleHeight", "Ripple Height", num(30.0), slider(0.0, 200.0, 0.0, 100.0, 1)),
-                p("spreading", "Spreading", num(100.0), slider(0.0, 1000.0, 0.0, 300.0, 1)),
-                p("light/lightIntensity", "Light Intensity", num(100.0), slider(0.0, 400.0, 0.0, 200.0, 1)),
-                p("light/lightColor", "Light Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("light/lightHeight", "Light Height", num(25.0), slider(-100.0, 100.0, -100.0, 100.0, 1)),
-                p("light/lightDirection", "Light Direction", num(-45.0), ParamUi::Angle),
-                p("shading/ambient", "Ambient", num(0.0), slider(-200.0, 200.0, -100.0, 100.0, 1)),
-                p("shading/diffuse", "Diffuse", num(0.0), slider(0.0, 200.0, 0.0, 100.0, 1)),
-                p("shading/specular", "Specular", num(20.0), slider(0.0, 200.0, 0.0, 100.0, 1)),
-                p("shading/roughness", "Roughness", num(0.05), slider(0.001, 1.0, 0.001, 0.5, 3)),
-            ],
-            drizzle,
-        ),
-        spec(
-            "ec.sim.ccstarburst",
-            "CC Star Burst",
-            vec![
-                p("scatter", "Scatter", num(100.0), slider(0.0, 1000.0, 0.0, 300.0, 1)),
-                p("speed", "Speed", num(1.0), slider(-10.0, 10.0, -4.0, 4.0, 2)),
-                p("phase", "Phase", num(0.0), ParamUi::Angle),
-                p("gridSpacing", "Grid Spacing", num(2.0), slider(1.0, 100.0, 1.0, 20.0, 0)),
-                p("size", "Size", num(100.0), slider(0.0, 1000.0, 0.0, 300.0, 1)),
-                p("blendWithOriginal", "Blend w. Original", num(0.0), pct()),
-            ],
-            star_burst,
-        ),
-        spec(
-            "ec.sim.ccparticleworld",
-            "CC Particle World",
-            vec![
-                p("birthRate", "Birth Rate", num(0.5), slider(0.0, 100.0, 0.0, 10.0, 2)),
-                p("longevity", "Longevity (sec)", num(1.0), slider(0.0, 100.0, 0.0, 10.0, 2)),
-                p("producer/producerX", "Position X", num(0.0), slider(-10.0, 10.0, -1.0, 1.0, 2)),
-                p("producer/producerY", "Position Y", num(0.0), slider(-10.0, 10.0, -1.0, 1.0, 2)),
-                p("producer/producerZ", "Position Z", num(0.0), slider(-10.0, 10.0, -1.0, 1.0, 2)),
-                p("producer/radiusX", "Radius X", num(0.025), slider(0.0, 10.0, 0.0, 1.0, 3)),
-                p("producer/radiusY", "Radius Y", num(0.025), slider(0.0, 10.0, 0.0, 1.0, 3)),
-                p("producer/radiusZ", "Radius Z", num(0.025), slider(0.0, 10.0, 0.0, 1.0, 3)),
-                p("physics/animation", "Animation", Value::Enum(0), popup(PW_ANIMS)),
-                p("physics/velocity", "Velocity", num(1.0), slider(-10.0, 10.0, 0.0, 5.0, 2)),
-                p("physics/inheritVelocity", "Inherit Velocity %", num(0.0), slider(-100.0, 100.0, -100.0, 100.0, 1)),
-                p("physics/gravity", "Gravity", num(0.5), slider(-10.0, 10.0, -2.0, 2.0, 3)),
-                p("physics/resistance", "Resistance", num(0.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
-                p("physics/extra", "Extra", num(1.0), slider(0.0, 10.0, 0.0, 2.0, 2)),
-                p("physics/extraAngle", "Extra Angle", num(360.0), ParamUi::Angle),
-                p("physics/directionAxis/axisX", "Axis X", num(0.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
-                p("physics/directionAxis/axisY", "Axis Y", num(-1.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
-                p("physics/directionAxis/axisZ", "Axis Z", num(0.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
-                p("physics/gravityVector/gravityX", "Gravity X", num(0.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
-                p("physics/gravityVector/gravityY", "Gravity Y", num(1.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
-                p("physics/gravityVector/gravityZ", "Gravity Z", num(0.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
-                p("particle/particleType", "Particle Type", Value::Enum(0), popup(PARTICLE_TYPES)),
-                p("particle/birthSize", "Birth Size", num(0.2), slider(0.0, 10.0, 0.0, 1.0, 3)),
-                p("particle/deathSize", "Death Size", num(0.2), slider(0.0, 10.0, 0.0, 1.0, 3)),
-                p("particle/sizeVariation", "Size Variation", num(0.0), pct()),
-                p("particle/maxOpacity", "Max Opacity", num(75.0), pct()),
-                p("particle/birthColor", "Birth Color", col(1.0, 1.0, 0.0), ParamUi::Color),
-                p("particle/deathColor", "Death Color", col(0.6, 0.0, 0.0), ParamUi::Color),
-                p("particle/transferMode", "Transfer Mode", Value::Enum(0), popup(&["Composite", "Screen", "Add", "Black Matte"])),
-                p("extras/effectCamera/distance", "Distance", num(2.0), slider(0.0, 100.0, 0.0, 10.0, 2)),
-                p("extras/effectCamera/rotationX", "Rotation X", num(0.0), ParamUi::Angle),
-                p("extras/effectCamera/rotationY", "Rotation Y", num(0.0), ParamUi::Angle),
-                p("extras/effectCamera/rotationZ", "Rotation Z", num(0.0), ParamUi::Angle),
-                p("extras/effectCamera/fov", "FOV", num(PW_FOV), slider(1.0, 179.0, 10.0, 120.0, 1)),
-                p("extras/randomSeed", "Random Seed", num(0.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
-            ],
-            particle_world,
-        ),
-        spec(
-            "ec.sim.ccparticlesystems2",
-            "CC Particle Systems II",
-            vec![
-                p("birthRate", "Birth Rate", num(2.0), slider(0.0, 100.0, 0.0, 20.0, 2)),
-                p("longevity", "Longevity (sec)", num(1.0), slider(0.0, 100.0, 0.0, 10.0, 2)),
-                p("producer/position", "Position", pt(0.5, 0.5), ParamUi::Point),
-                p("producer/radiusX", "Radius X", num(0.0), slider(0.0, 2000.0, 0.0, 200.0, 1)),
-                p("producer/radiusY", "Radius Y", num(0.0), slider(0.0, 2000.0, 0.0, 200.0, 1)),
-                p("physics/animation", "Animation", Value::Enum(0), popup(PW_ANIMS)),
-                p("physics/velocity", "Velocity", num(2.0), slider(-20.0, 20.0, 0.0, 10.0, 2)),
-                p("physics/inheritVelocity", "Inherit Velocity %", num(0.0), slider(-100.0, 100.0, -100.0, 100.0, 1)),
-                p("physics/gravity", "Gravity", num(1.0), slider(-20.0, 20.0, -5.0, 5.0, 2)),
-                p("physics/resistance", "Resistance", num(0.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
-                p("physics/direction", "Direction", num(0.0), ParamUi::Angle),
-                p("physics/extra", "Extra", num(1.0), slider(0.0, 10.0, 0.0, 2.0, 2)),
-                p("particle/particleType", "Particle Type", Value::Enum(0), popup(PARTICLE_TYPES)),
-                p("particle/birthSize", "Birth Size", num(0.5), slider(0.0, 20.0, 0.0, 5.0, 2)),
-                p("particle/deathSize", "Death Size", num(1.5), slider(0.0, 20.0, 0.0, 5.0, 2)),
-                p("particle/sizeVariation", "Size Variation", num(0.0), pct()),
-                p("particle/maxOpacity", "Max Opacity", num(75.0), pct()),
-                p("particle/birthColor", "Birth Color", col(1.0, 1.0, 0.0), ParamUi::Color),
-                p("particle/deathColor", "Death Color", col(0.6, 0.0, 0.0), ParamUi::Color),
-                p("particle/transferMode", "Transfer Mode", Value::Enum(0), popup(&["Composite", "Screen", "Add", "Black Matte"])),
-                p("randomSeed", "Random Seed", num(0.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
-            ],
-            particle_systems2,
-        ),
-        spec(
-            "ec.sim.ccmrmercury",
-            "CC Mr. Mercury",
-            vec![
-                p("radiusX", "Radius X", num(50.0), slider(0.0, 2000.0, 0.0, 300.0, 1)),
-                p("radiusY", "Radius Y", num(50.0), slider(0.0, 2000.0, 0.0, 300.0, 1)),
-                p("producer", "Producer", pt(0.5, 0.5), ParamUi::Point),
-                p("direction", "Direction", num(0.0), ParamUi::Angle),
-                p("velocity", "Velocity", num(1.0), slider(-20.0, 20.0, 0.0, 5.0, 2)),
-                p("birthRate", "Birth Rate", num(1.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
-                p("longevity", "Longevity (sec)", num(2.0), slider(0.0, 100.0, 0.0, 10.0, 2)),
-                p("gravity", "Gravity", num(0.5), slider(-20.0, 20.0, -5.0, 5.0, 2)),
-                p("resistance", "Resistance", num(0.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
-                p("extra", "Extra", num(1.0), slider(0.0, 10.0, 0.0, 2.0, 2)),
-                p("animation", "Animation", Value::Enum(0), popup(PW_ANIMS)),
-                p("blobInfluence", "Blob Influence", num(100.0), slider(0.0, 400.0, 0.0, 200.0, 1)),
-                p("blobBirthSize", "Blob Birth Size", num(0.5), slider(0.0, 10.0, 0.0, 2.0, 2)),
-                p("blobDeathSize", "Blob Death Size", num(0.25), slider(0.0, 10.0, 0.0, 2.0, 2)),
-                p("light/lightIntensity", "Light Intensity", num(100.0), slider(0.0, 400.0, 0.0, 200.0, 1)),
-                p("light/lightColor", "Light Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("light/lightHeight", "Light Height", num(50.0), slider(-100.0, 100.0, -100.0, 100.0, 1)),
-                p("light/lightDirection", "Light Direction", num(-45.0), ParamUi::Angle),
-                p("shading/ambient", "Ambient", num(0.0), slider(-200.0, 200.0, -100.0, 100.0, 1)),
-                p("shading/diffuse", "Diffuse", num(75.0), slider(0.0, 200.0, 0.0, 100.0, 1)),
-                p("shading/specular", "Specular", num(50.0), slider(0.0, 200.0, 0.0, 100.0, 1)),
-                p("shading/roughness", "Roughness", num(0.05), slider(0.001, 1.0, 0.001, 0.5, 3)),
-                p("shading/metal", "Metal", num(100.0), pct()),
-            ],
-            mr_mercury,
-        ),
-    ]
-}
+mod common;
+mod engine;
+mod particle_fx;
+mod registry;
+mod sprites;
+mod weather;
+
+pub(crate) use common::{h, hs, pct, pt, spec};
+pub use engine::particle_state;
+#[cfg(test)]
+pub(crate) use engine::{PState, PW_ANIMS, Phys, simulate};
+#[cfg(test)]
+use engine::{PW_EFFECT_CAMERA, sim_key};
+pub(crate) use engine::{SPS, steps_at};
+pub use particle_fx::{Blob, mercury_blobs};
+pub use registry::{specs, sprite_plan};
+pub use sprites::{Acc, Post, Shape, Sprite, SpritePlan, Tint};
+pub(crate) use sprites::{combine, raster, splat};
+pub use weather::{Bubble, bubble_list, drizzle_drops};
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::{EffectEnv, run_fx};
-
-    fn grey(w: u32, hh: u32) -> Image {
-        Image::filled(w, hh, [0.2, 0.2, 0.2, 1.0])
-    }
-
-    fn ramp(w: u32, hh: u32) -> Image {
-        let mut img = Image::new(w, hh);
-        for y in 0..hh {
-            for x in 0..w {
-                img.set(x, y, [x as f32 / w as f32, y as f32 / hh as f32, 0.4, 1.0]);
-            }
-        }
-        img
-    }
-
-    fn run(id: &str, vals: &[(&str, Value)], img: Image, t: f64) -> Image {
-        run_fx(id, vals, img, t, EffectEnv::default()).img
-    }
-
-    fn diff(a: &Image, b: &Image) -> f32 {
-        a.data.iter().zip(&b.data).map(|(p, q)| (0..4).map(|k| (p[k] - q[k]).abs()).sum::<f32>()).sum()
-    }
-
-    /// Centre of mass (luminance-weighted difference from `base`), `[-1, -1]` when equal.
-    fn mass(img: &Image, base: &Image) -> [f32; 2] {
-        let (mut m, mut sx, mut sy) = (0.0, 0.0, 0.0);
-        for y in 0..img.height {
-            for x in 0..img.width {
-                let i = img.idx(x, y);
-                let d: f32 = (0..3).map(|k| (img.data[i][k] - base.data[i][k]).abs()).sum();
-                m += d;
-                sx += d * x as f32;
-                sy += d * y as f32;
-            }
-        }
-        if m > 0.0 { [sx / m, sy / m] } else { [-1.0; 2] }
-    }
-
-    /// [`mass`] in y.
-    fn mass_y(img: &Image, base: &Image) -> f32 {
-        mass(img, base)[1]
-    }
-
-    #[test]
-    fn rasteriser_over_and_add() {
-        let s = [Sprite::new(5.0, 5.0, 2.0, [1.0, 0.0, 0.0, 1.0], Shape::Disc)];
-        let img = splat(10, 40, &s, Acc::Over);
-        assert!(img.get(5, 5)[0] > 0.99 && img.get(9, 30)[3] == 0.0);
-        let two = [s[0], s[0]];
-        let add = splat(10, 40, &two, Acc::Add);
-        assert!(add.get(5, 5)[0] > 1.9);
-        // Items spanning band boundaries are drawn in every band.
-        let tall = [Sprite::new(5.0, 16.0, 6.0, [0.0, 1.0, 0.0, 1.0], Shape::Square)];
-        let t = splat(10, 40, &tall, Acc::Over);
-        assert!(t.get(5, 13)[1] > 0.9 && t.get(5, 18)[1] > 0.9);
-    }
-
-    #[test]
-    fn rainfall_deterministic_and_falls() {
-        let vals = [("drops", num(200.0)), ("opacity", num(100.0)), ("extras/appearance", Value::Enum(1)), ("color", col(1.0, 1.0, 1.0))];
-        let a = run("ec.sim.ccrainfall", &vals, grey(40, 40), 0.5);
-        let b = run("ec.sim.ccrainfall", &vals, grey(40, 40), 0.5);
-        assert_eq!(a, b);
-        assert!(diff(&a, &grey(40, 40)) > 1.0, "drops visible");
-        let none = run("ec.sim.ccrainfall", &[("drops", num(0.0))], grey(40, 40), 0.5);
-        assert_eq!(none, grey(40, 40));
-        let later = run("ec.sim.ccrainfall", &vals, grey(40, 40), 0.52);
-        assert!(diff(&a, &later) > 0.1, "rain moves");
-    }
-
-    #[test]
-    fn snowfall_deterministic_and_moves() {
-        let vals = [("flakes", num(300.0))];
-        let a = run("ec.sim.ccsnowfall", &vals, grey(40, 40), 1.0);
-        assert_eq!(a, run("ec.sim.ccsnowfall", &vals, grey(40, 40), 1.0));
-        assert!(diff(&a, &grey(40, 40)) > 1.0);
-        assert!(diff(&a, &run("ec.sim.ccsnowfall", &vals, grey(40, 40), 1.2)) > 0.1);
-        let off = run("ec.sim.ccsnowfall", &[("flakes", num(300.0)), ("compositeWithOriginal", Value::Bool(false))], grey(40, 40), 1.0);
-        assert!(off.data.iter().any(|p| p[3] == 0.0), "without original the background is transparent");
-    }
-
-    #[test]
-    fn bubbles_rise() {
-        let vals = [("bubbleAmount", num(30.0)), ("bubbleSize", num(3.0))];
-        let a = run("ec.sim.ccbubbles", &vals, ramp(40, 40), 0.3);
-        assert_eq!(a, run("ec.sim.ccbubbles", &vals, ramp(40, 40), 0.3));
-        assert!(a.data.iter().any(|p| p[3] > 0.5));
-        let none = run("ec.sim.ccbubbles", &[("bubbleAmount", num(0.0))], ramp(40, 40), 0.3);
-        assert!(none.data.iter().all(|p| p[3] == 0.0), "bubbles replace the layer");
-        // A single slow bubble moves up over a short time.
-        let one = [("bubbleAmount", num(1.0)), ("bubbleSize", num(4.0)), ("wobbleAmplitude", num(0.0)), ("bubbleSpeed", num(0.2))];
-        let blank = Image::new(40, 40);
-        let y0 = mass_y(&run("ec.sim.ccbubbles", &one, ramp(40, 40), 0.0), &blank);
-        let y1 = mass_y(&run("ec.sim.ccbubbles", &one, ramp(40, 40), 0.1), &blank);
-        assert!(y0 >= 0.0 && y1 >= 0.0 && (y1 < y0 || y0 < 8.0), "{y0} -> {y1}");
-    }
-
-    #[test]
-    fn drizzle_ripples() {
-        let a = run("ec.sim.ccdrizzle", &[], ramp(48, 48), 0.6);
-        assert_eq!(a, run("ec.sim.ccdrizzle", &[], ramp(48, 48), 0.6));
-        assert!(diff(&a, &ramp(48, 48)) > 0.1);
-        let none = run("ec.sim.ccdrizzle", &[("dripRate", num(0.0))], ramp(48, 48), 0.6);
-        assert_eq!(none, ramp(48, 48));
-    }
-
-    #[test]
-    fn star_burst_moves_stars() {
-        let a = run("ec.sim.ccstarburst", &[("gridSpacing", num(4.0))], ramp(40, 40), 0.5);
-        assert_eq!(a, run("ec.sim.ccstarburst", &[("gridSpacing", num(4.0))], ramp(40, 40), 0.5));
-        assert!(a.data.iter().any(|p| p[3] > 0.0));
-        let b = run("ec.sim.ccstarburst", &[("gridSpacing", num(4.0))], ramp(40, 40), 0.9);
-        assert!(diff(&a, &b) > 0.5);
-        let full = run("ec.sim.ccstarburst", &[("blendWithOriginal", num(100.0))], ramp(40, 40), 0.5);
-        assert!(diff(&full, &ramp(40, 40)) < 1e-3);
-    }
-
-    fn pw_vals(seed: f64) -> Vec<(&'static str, Value)> {
-        vec![
-            ("birthRate", num(1.0)),
-            ("extras/randomSeed", num(seed)),
-            ("particle/particleType", Value::Enum(2)),
-            ("particle/birthSize", num(0.3)),
-            ("particle/deathSize", num(0.3)),
-        ]
-    }
-
-    /// #1195: with the comp's shutter open, the particles smear across it: the average of the
-    /// sampled sprite fields differs from the sharp frame, touches more pixels and keeps the
-    /// alpha energy.
-    #[test]
-    fn particle_world_motion_blur_trails() {
-        let v = pw_vals(21.0);
-        let blank = Image::new(40, 40);
-        let sharp = run("ec.sim.ccparticleworld", &v, blank.clone(), 2.0);
-        let blurred = crate::run_fx(
-            "ec.sim.ccparticleworld",
-            &v,
-            blank.clone(),
-            2.0,
-            EffectEnv { frame_rate: 10.0, shutter: Some((360.0, -180.0, 8)), ..Default::default() },
-        )
-        .img;
-        assert!(sharp.data.iter().any(|p| p[3] > 0.0), "sharp frame has particles");
-        assert_ne!(sharp.data, blurred.data, "the shutter smears the particles");
-        let lit = |img: &Image| img.data.iter().filter(|p| p[3] > 0.005).count();
-        let sum = |img: &Image| img.data.iter().map(|p| p[3]).sum::<f32>();
-        assert!(lit(&blurred) > lit(&sharp), "trails light more pixels: {} vs {}", lit(&blurred), lit(&sharp));
-        let (sa, ba) = (sum(&sharp), sum(&blurred));
-        assert!((ba - sa).abs() < sa * 0.6 + 1.0, "alpha energy roughly kept: {ba} vs {sa}");
-    }
-
-    #[test]
-    fn particle_world_seek_consistent() {
-        let v = pw_vals(11.0);
-        let direct = run("ec.sim.ccparticleworld", &v, Image::new(40, 40), 2.0);
-        let v2 = pw_vals(12.0);
-        let _ = run("ec.sim.ccparticleworld", &v2, Image::new(40, 40), 1.0);
-        let stepped = run("ec.sim.ccparticleworld", &v2, Image::new(40, 40), 2.0);
-        let direct2 = run("ec.sim.ccparticleworld", &v2, Image::new(40, 40), 2.0);
-        assert_eq!(stepped, direct2);
-        assert!(direct.data.iter().any(|p| p[3] > 0.0), "particles alive");
-        // Before birth nothing is drawn.
-        let t0 = run("ec.sim.ccparticleworld", &v, Image::new(40, 40), 0.0);
-        assert!(t0.data.iter().all(|p| p[3] == 0.0));
-    }
-
-    #[test]
-    fn engine_resume_equals_from_scratch() {
-        for anim in 0..PW_ANIMS.len() as u32 {
-            let phys = Phys {
-                rate: 90.0,
-                life: 1.5,
-                producer: [0.0; 3],
-                radius: [0.05; 3],
-                anim,
-                speed: 0.5,
-                gravity: [0.0, 0.5, 0.0],
-                resistance: 0.2,
-                axis: [0.0, -1.0, 0.0],
-                extra: 1.0,
-                extra_angle: 60.0,
-                seed: 9,
-                max: 10_000,
-                flat: anim % 2 == 0,
-            };
-            let a: SimCache<PState> = SimCache::new(2);
-            let b: SimCache<PState> = SimCache::new(2);
-            let direct = simulate(&a, 1, 2.0, &phys);
-            let _ = simulate(&b, 1, 1.0, &phys);
-            let _ = simulate(&b, 1, 0.37, &phys);
-            let resumed = simulate(&b, 1, 2.0, &phys);
-            assert_eq!(direct.parts.len(), resumed.parts.len(), "anim {anim}");
-            assert!(direct.parts.iter().zip(&resumed.parts).all(|(p, q)| p.p == q.p && p.v == q.v && p.id == q.id), "anim {anim}");
-            assert!(!direct.parts.is_empty());
-        }
-    }
-
-    #[test]
-    fn particle_world_gravity_pulls_down() {
-        let base = |g: f64| {
-            vec![
-                ("birthRate", num(2.0)),
-                ("physics/velocity", num(0.2)),
-                ("physics/gravity", num(g)),
-                ("particle/particleType", Value::Enum(2)),
-                ("particle/birthSize", num(0.2)),
-                ("particle/deathSize", num(0.2)),
-                ("longevity", num(3.0)),
-            ]
-        };
-        let blank = Image::new(48, 48);
-        let up = mass_y(&run("ec.sim.ccparticleworld", &base(0.0), blank.clone(), 1.0), &blank);
-        let down = mass_y(&run("ec.sim.ccparticleworld", &base(2.0), blank.clone(), 1.0), &blank);
-        assert!(down > up + 2.0, "{up} {down}");
-    }
-
-    /// A comp whose camera is `camera` ([`crate::CompScene::camera`]); `layer`: a camera layer
-    /// (else the comp's default view).
-    struct Comp {
-        camera: [[f64; 4]; 3],
-        layer: bool,
-    }
-    impl crate::EffectHost for Comp {
-        fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
-            None
-        }
-        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
-            None
-        }
-        fn comp_scene(&self) -> Option<crate::CompScene> {
-            Some(crate::CompScene { camera: Some(self.camera), camera_layer: self.layer, light: None })
-        }
-    }
-
-    /// A camera `d` px in front of layer point `c` looking at it, moved right by `dx` px and
-    /// zoomed by `zoom` (1 = identity on the layer plane): `c + zoom·d·(p − c − dx) / (z + d)`.
-    fn cam(c: [f64; 2], d: f64, dx: f64, zoom: f64) -> [[f64; 4]; 3] {
-        let k = zoom * d;
-        [[k, 0.0, c[0], d * c[0] - k * (c[0] + dx)], [0.0, k, c[1], d * c[1] - k * c[1]], [0.0, 0.0, 1.0, d]]
-    }
-
-    fn pw_in(comp: &Comp, vals: &[(&str, Value)]) -> Image {
-        run_fx("ec.sim.ccparticleworld", vals, Image::new(48, 48), 1.0, EffectEnv { host: Some(comp), ..Default::default() }).img
-    }
-
-    fn finite(img: &Image) -> bool {
-        img.data.iter().all(|p| p.iter().all(|c| c.is_finite()))
-    }
-
-    /// #397: with a camera layer in the comp, the particles are seen through it.
-    #[test]
-    fn particle_world_follows_the_comp_camera() {
-        let v = pw_vals(3.0);
-        let blank = Image::new(48, 48);
-        let here = Comp { camera: cam([24.0, 24.0], 96.0, 0.0, 1.0), layer: true };
-        let base = pw_in(&here, &v);
-        assert!(base.data.iter().any(|p| p[3] > 0.0), "particles alive");
-        // Moving the camera right moves the particles left.
-        let moved = pw_in(&Comp { camera: cam([24.0, 24.0], 96.0, 8.0, 1.0), ..here }, &v);
-        let (a, b) = (mass(&base, &blank), mass(&moved, &blank));
-        assert!(b[0] < a[0] - 4.0 && (b[1] - a[1]).abs() < 2.0, "{a:?} -> {b:?}");
-        // Zooming in spreads them out.
-        let zoomed = pw_in(&Comp { camera: cam([24.0, 24.0], 96.0, 0.0, 2.0), ..here }, &v);
-        let cover = |i: &Image| i.data.iter().filter(|p| p[3] > 0.01).count();
-        assert!(cover(&zoomed) > cover(&base), "{} {}", cover(&zoomed), cover(&base));
-        // The Effect Camera is ignored then.
-        let mut turned = v.clone();
-        turned.push(("extras/effectCamera/rotationY", num(60.0)));
-        assert_eq!(pw_in(&here, &turned), base);
-        // The comp's default view (no camera layer) leaves it to the Effect Camera.
-        let default_view = Comp { layer: false, ..here };
-        assert_eq!(pw_in(&default_view, &v), run("ec.sim.ccparticleworld", &v, blank.clone(), 1.0));
-        // A camera facing away, or a degenerate one, draws nothing and never NaN.
-        for camera in [[[96.0, 0.0, 24.0, 0.0], [0.0, 96.0, 24.0, 0.0], [0.0, 0.0, -1.0, -96.0]], [[0.0; 4]; 3], [[f64::NAN; 4]; 3]] {
-            assert_eq!(pw_in(&Comp { camera, layer: true }, &v), blank);
-        }
-        // A camera among the particles draws the ones in front of it.
-        let inside = pw_in(&Comp { camera: cam([24.0, 24.0], 1.0, 0.0, 1.0), ..here }, &v);
-        assert!(finite(&inside));
-    }
-
-    /// Extras ▸ Effect Camera: the defaults are the fixed camera Particle World always had.
-    #[test]
-    fn particle_world_effect_camera() {
-        let v = pw_vals(5.0);
-        let base = run("ec.sim.ccparticleworld", &v, Image::new(48, 48), 1.0);
-        let with = |extra: &[(&'static str, Value)]| {
-            let mut w = v.clone();
-            w.extend_from_slice(extra);
-            run("ec.sim.ccparticleworld", &w, Image::new(48, 48), 1.0)
-        };
-        // Missing parameters (projects saved before) read as the defaults.
-        let spec = crate::find("ec.sim.ccparticleworld").unwrap();
-        let mut params = crate::Params { values: spec.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-        params.values.retain(|k, _| !k.starts_with(PW_EFFECT_CAMERA));
-        for (k, val) in &v {
-            params.values.insert(k.to_string(), val.clone());
-        }
-        let ctx = EffectCtx { params: &params, time: 1.0, layer_size: [48.0, 48.0], seed: 1, adjustment: false, env: EffectEnv::default() };
-        assert_eq!(crate::apply(spec, &ctx, Buf { img: Image::new(48, 48), offset: [0.0; 2], scale: 1.0 }).img, base);
-        assert_eq!(with(&[("extras/effectCamera/fov", num(f64::NAN))]), base);
-        // Turning or pulling back the camera changes the view.
-        let turned = with(&[("extras/effectCamera/rotationY", num(60.0))]);
-        assert!(diff(&turned, &base) > 1.0);
-        let cover = |i: &Image| i.data.iter().filter(|p| p[3] > 0.01).count();
-        let far = with(&[("extras/effectCamera/distance", num(4.0))]);
-        assert!(cover(&far) < cover(&base), "{} {}", cover(&far), cover(&base));
-        assert!(diff(&with(&[("extras/effectCamera/fov", num(120.0))]), &base) > 0.1);
-        // Extremes never panic or produce NaN.
-        for extra in [
-            ("extras/effectCamera/distance", num(0.0)),
-            ("extras/effectCamera/distance", num(-5.0)),
-            ("extras/effectCamera/fov", num(0.0)),
-            ("extras/effectCamera/fov", num(180.0)),
-            ("extras/effectCamera/rotationX", num(1e12)),
-        ] {
-            assert!(finite(&with(std::slice::from_ref(&extra))), "{extra:?}");
-        }
-        // Moving the camera doesn't restart the simulation.
-        let key = |pr: &crate::Params| {
-            sim_key(&EffectCtx { params: pr, time: 1.0, layer_size: [48.0, 48.0], seed: 1, adjustment: false, env: EffectEnv::default() }, 1)
-        };
-        let mut moved = params.clone();
-        moved.values.insert("extras/effectCamera/rotationZ".into(), num(30.0));
-        assert_eq!(key(&params), key(&moved));
-        moved.values.insert("extras/randomSeed".into(), num(9.0));
-        assert_ne!(key(&params), key(&moved));
-    }
-
-    #[test]
-    fn particle_systems2_seek_and_direction() {
-        let v = vec![
-            ("producer/position", pt(24.0, 24.0)),
-            ("birthRate", num(3.0)),
-            ("physics/gravity", num(0.0)),
-            ("physics/velocity", num(1.0)),
-            ("physics/animation", Value::Enum(1)),
-        ];
-        let _ = run("ec.sim.ccparticlesystems2", &v, Image::new(48, 48), 0.5);
-        let a = run("ec.sim.ccparticlesystems2", &v, Image::new(48, 48), 1.0);
-        let mut v2 = v.clone();
-        v2.push(("randomSeed", num(0.0)));
-        assert_eq!(a, run("ec.sim.ccparticlesystems2", &v2, Image::new(48, 48), 1.0));
-        // Direction 0° (up): particles above the producer.
-        let blank = Image::new(48, 48);
-        let y = mass_y(&a, &blank);
-        assert!((0.0..24.0).contains(&y), "{y}");
-        // The particles replace the layer: with none born it is empty.
-        let none = run("ec.sim.ccparticlesystems2", &[("birthRate", num(0.0))], grey(20, 20), 1.0);
-        assert_eq!(none, Image::new(20, 20));
-    }
-
-    /// CC Particle World and CC Particle Systems II replace their layer with the particles, in
-    /// every Transfer Mode (which only sets how particles meet each other). SceneYard frames from
-    /// After Effects 2026 show no trace of the source solid: "Task Preparation UI" (black solids
-    /// under fireworks hid a white page), "Burnout matchstick" (a red rectangle around the
-    /// flame), "Documentary Man Falling" (a black block over the light).
-    #[test]
-    fn cc_particles_replace_their_layer() {
-        let red = || {
-            let mut img = Image::new(48, 48);
-            img.data.iter_mut().for_each(|p| *p = [0.7, 0.1, 0.1, 1.0]);
-            img
-        };
-        for id in ["ec.sim.ccparticlesystems2", "ec.sim.ccparticleworld"] {
-            for mode in 0..4 {
-                let v = vec![("birthRate", num(3.0)), ("particle/transferMode", Value::Enum(mode))];
-                let _ = run(id, &v, red(), 0.5);
-                let out = run(id, &v, red(), 1.0);
-                // No source left: the corners, far from the producer, are clear.
-                for (x, y) in [(0, 0), (47, 0), (0, 47), (47, 47)] {
-                    assert!(out.get(x, y)[3] < 1e-6, "{id} mode {mode} ({x},{y}): {:?}", out.get(x, y));
-                }
-                assert!(out.data.iter().any(|p| p[3] > 0.05), "{id} mode {mode}: particles drawn");
-            }
-        }
-    }
-
-    #[test]
-    fn mercury_blobs_and_seek() {
-        let v = vec![("producer", pt(24.0, 16.0)), ("radiusX", num(5.0)), ("radiusY", num(5.0)), ("birthRate", num(3.0))];
-        let _ = run("ec.sim.ccmrmercury", &v, ramp(48, 48), 0.7);
-        let a = run("ec.sim.ccmrmercury", &v, ramp(48, 48), 1.4);
-        let mut v2 = v.clone();
-        v2.push(("shading/metal", num(100.0)));
-        let b = run("ec.sim.ccmrmercury", &v2, ramp(48, 48), 1.4);
-        assert_eq!(a, b);
-        assert!(a.data.iter().any(|p| p[3] > 0.5), "blobs visible");
-        let none = run("ec.sim.ccmrmercury", &[("birthRate", num(0.0))], ramp(48, 48), 1.4);
-        assert!(none.data.iter().all(|p| p[3] == 0.0));
-    }
-
-    #[test]
-    fn half_resolution_scales_sprites() {
-        // Downsampled buffers render the same layout at half size.
-        let s = crate::find("ec.sim.ccsnowfall").unwrap();
-        let mut params = crate::Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
-        params.values.insert("flakes".into(), num(50.0));
-        params.values.insert("offset".into(), pt(20.0, 20.0));
-        let ctx = EffectCtx { params: &params, time: 0.5, layer_size: [40.0, 40.0], seed: 1, adjustment: false, env: EffectEnv::default() };
-        let full = crate::apply(s, &ctx, Buf { img: grey(40, 40), offset: [0.0; 2], scale: 1.0 });
-        let half = crate::apply(s, &ctx, Buf { img: grey(20, 20), offset: [0.0; 2], scale: 0.5 });
-        let sum = |i: &Image| i.data.iter().map(|p| p[0]).sum::<f32>() / i.data.len() as f32;
-        assert!((sum(&full.img) - sum(&half.img)).abs() < 0.05, "{} {}", sum(&full.img), sum(&half.img));
-    }
-}
+mod tests;
diff --git a/crates/effects/src/sim/common.rs b/crates/effects/src/sim/common.rs
new file mode 100644
index 000000000..294d787f1
--- /dev/null
+++ b/crates/effects/src/sim/common.rs
@@ -0,0 +1,25 @@
+use super::{EffectSpec, ParamUi, Value, hash1, slider};
+
+pub(crate) fn spec(id: &'static str, name: &'static str, params: Vec<crate::ParamSpec>, render: crate::RenderFn) -> EffectSpec {
+    EffectSpec { id, name, category: "Simulation", params, render, gpu: false, float: true }
+}
+
+pub(crate) fn pt(x: f64, y: f64) -> Value {
+    Value::Vec2([x, y])
+}
+
+pub(crate) fn pct() -> ParamUi {
+    slider(0.0, 100.0, 0.0, 100.0, 1)
+}
+
+/// Deterministic hash → [0, 1).
+#[inline]
+pub(crate) fn h(i: u32, k: u32, seed: u32) -> f32 {
+    hash1(i, k, seed)
+}
+
+/// Signed hash → [-1, 1).
+#[inline]
+pub(crate) fn hs(i: u32, k: u32, seed: u32) -> f32 {
+    hash1(i, k, seed) * 2.0 - 1.0
+}
diff --git a/crates/effects/src/sim/engine.rs b/crates/effects/src/sim/engine.rs
new file mode 100644
index 000000000..b379636ce
--- /dev/null
+++ b/crates/effects/src/sim/engine.rs
@@ -0,0 +1,288 @@
+use super::common::{h, hs};
+use super::particle_fx::{PS2_CACHE, PW_CACHE, ps2_phys, pw_phys};
+use super::sprites::{Shape, Sprite};
+use super::{Buf, EffectCtx, Image, IntoParallelRefMutIterator, ParallelIterator, SimCache, params_key_except, value_noise};
+
+// ------------------------------------------------------------------ particle engine
+
+/// Steps per second of the stepped particle simulations.
+pub(crate) const SPS: f64 = 60.0;
+
+/// Number of whole steps reached at layer time `t`.
+pub(crate) fn steps_at(t: f64) -> u64 {
+    if t <= 0.0 { 0 } else { (t * SPS + 1e-6).floor() as u64 }
+}
+
+#[derive(Clone, Debug)]
+pub(crate) struct Particle {
+    pub p: [f32; 3],
+    pub v: [f32; 3],
+    pub age: f32,
+    pub life: f32,
+    /// Per-particle random in [0, 1) (size variation, colour jitter…).
+    pub rnd: f32,
+    pub id: u32,
+}
+
+#[derive(Clone, Debug, Default)]
+pub(crate) struct PState {
+    pub parts: Vec<Particle>,
+    pub carry: f64,
+    pub next_id: u32,
+}
+
+/// Physics configuration (world units; y down).
+#[derive(Clone, Copy, Debug)]
+pub(crate) struct Phys {
+    /// Particles per second.
+    pub rate: f64,
+    pub life: f32,
+    pub producer: [f32; 3],
+    pub radius: [f32; 3],
+    pub anim: u32,
+    pub speed: f32,
+    pub gravity: [f32; 3],
+    pub resistance: f32,
+    pub axis: [f32; 3],
+    pub extra: f32,
+    pub extra_angle: f32,
+    pub seed: u32,
+    pub max: usize,
+    /// 2D systems keep z = 0.
+    pub flat: bool,
+}
+
+pub(crate) const PW_ANIMS: &[&str] =
+    &["Explosive", "Direction Axis", "Cone Axis", "Viscouse", "Twirly", "Vortex", "Fire", "Jet Sideways", "Fractal Omni", "Fractal Uni"];
+
+pub(super) fn norm3(v: [f32; 3]) -> [f32; 3] {
+    let l = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt();
+    if l > 1e-9 { [v[0] / l, v[1] / l, v[2] / l] } else { [0.0, -1.0, 0.0] }
+}
+
+fn rand_dir(i: u32, k: u32, seed: u32, flat: bool) -> [f32; 3] {
+    if flat {
+        let a = h(i, k, seed) * std::f32::consts::TAU;
+        return [a.cos(), a.sin(), 0.0];
+    }
+    let z = hs(i, k, seed);
+    let a = h(i, k + 1, seed) * std::f32::consts::TAU;
+    let r = (1.0 - z * z).max(0.0).sqrt();
+    [r * a.cos(), r * a.sin(), z]
+}
+
+impl Phys {
+    fn spawn(&self, id: u32) -> Particle {
+        let seed = self.seed;
+        let mut p = [0.0f32; 3];
+        // Uniform in the producer ellipsoid.
+        let u = rand_dir(id, 1, seed, self.flat);
+        let rr = h(id, 3, seed).powf(if self.flat { 0.5 } else { 1.0 / 3.0 });
+        for k in 0..3 {
+            p[k] = self.producer[k] + u[k] * self.radius[k] * rr;
+        }
+        if self.flat {
+            p[2] = 0.0;
+        }
+        let ax = norm3(self.axis);
+        let jitter = rand_dir(id, 5, seed, self.flat);
+        let dir = match self.anim {
+            1 | 9 => norm3([ax[0] + jitter[0] * 0.08, ax[1] + jitter[1] * 0.08, ax[2] + jitter[2] * 0.08]),
+            2 => {
+                let k = (self.extra_angle.to_radians() * 0.5).tan().abs().min(20.0);
+                norm3([ax[0] + jitter[0] * k * h(id, 8, seed), ax[1] + jitter[1] * k * h(id, 8, seed), ax[2] + jitter[2] * k * h(id, 8, seed)])
+            }
+            5 => [jitter[0], 0.0, if self.flat { 0.0 } else { jitter[2] }],
+            6 => norm3([jitter[0] * 0.25, -1.0, jitter[2] * 0.25]),
+            7 => norm3([1.0, jitter[1] * 0.05, jitter[2] * 0.05]),
+            _ => jitter,
+        };
+        let sp = self.speed * (0.5 + 0.5 * h(id, 9, seed));
+        let mut v = [dir[0] * sp, dir[1] * sp, dir[2] * sp];
+        if self.flat {
+            v[2] = 0.0;
+        }
+        let life = self.life * (0.8 + 0.4 * h(id, 10, seed));
+        Particle { p, v, age: 0.0, life, rnd: h(id, 11, seed), id }
+    }
+
+    pub(crate) fn step(&self, st: &mut PState, step: u64) {
+        let dt = (1.0 / SPS) as f32;
+        let t = step as f32 * dt;
+        let mut drag = self.resistance;
+        if self.anim == 3 {
+            drag += 3.0 * self.extra.max(0.1);
+        }
+        let damp = (-drag * dt).exp();
+        let seed = self.seed;
+        st.parts.par_iter_mut().for_each(|q| {
+            let mut a = self.gravity;
+            match self.anim {
+                4 => {
+                    // Twirly: swirl around the vertical axis through the producer.
+                    let (dx, dz) = (q.p[0] - self.producer[0], q.p[2] - self.producer[2]);
+                    let k = 4.0 * self.extra;
+                    a[0] += -dz * k;
+                    a[2] += dx * k;
+                    if self.flat {
+                        let dy = q.p[1] - self.producer[1];
+                        a[0] += -dy * k;
+                        a[1] += dx * k;
+                    }
+                }
+                5 => {
+                    // Vortex: strong tangential + inward pull.
+                    let (dx, dy) = (q.p[0] - self.producer[0], q.p[1] - self.producer[1]);
+                    let k = 6.0 * self.extra;
+                    a[0] += -dy * k - dx * 2.0;
+                    a[1] += dx * k - dy * 2.0;
+                }
+                6 => {
+                    // Fire: buoyant, flickering turbulence.
+                    let n = value_noise(q.p[0] * 8.0, q.p[1] * 8.0, t * 3.0, seed) - 0.5;
+                    a[0] += n * 4.0 * self.extra;
+                    a[1] -= self.gravity[1] * 1.5 + 0.3 * self.extra;
+                }
+                8 | 9 => {
+                    let f = 6.0 * self.extra;
+                    a[0] += (value_noise(q.p[0] * 5.0, q.p[1] * 5.0, q.p[2] * 5.0 + t, seed) - 0.5) * f;
+                    a[1] += (value_noise(q.p[0] * 5.0 + 17.0, q.p[1] * 5.0, q.p[2] * 5.0 + t, seed) - 0.5) * f;
+                    if !self.flat {
+                        a[2] += (value_noise(q.p[0] * 5.0, q.p[1] * 5.0 + 31.0, q.p[2] * 5.0 + t, seed) - 0.5) * f;
+                    }
+                }
+                _ => {}
+            }
+            for k in 0..3 {
+                q.v[k] = (q.v[k] + a[k] * dt) * damp;
+                q.p[k] += q.v[k] * dt;
+            }
+            if self.flat {
+                q.p[2] = 0.0;
+                q.v[2] = 0.0;
+            }
+            q.age += dt;
+        });
+        st.parts.retain(|q| q.age < q.life);
+        st.carry += self.rate / SPS;
+        let n = st.carry.floor() as u32;
+        st.carry -= n as f64;
+        for _ in 0..n {
+            if st.parts.len() >= self.max {
+                break;
+            }
+            let id = st.next_id;
+            st.next_id = st.next_id.wrapping_add(1);
+            // Sub-step birth offset keeps continuous streams smooth.
+            let mut q = self.spawn(id);
+            let frac = h(id, 12, seed) * dt;
+            for k in 0..3 {
+                q.p[k] += q.v[k] * frac;
+            }
+            q.age = frac;
+            st.parts.push(q);
+        }
+    }
+}
+
+impl Phys {
+    /// The backend description (per-step and per-spawn constants evaluated here, in f32).
+    pub(crate) fn desc(&self) -> crate::psim::EngineDesc {
+        let mut drag = self.resistance;
+        if self.anim == 3 {
+            drag += 3.0 * self.extra.max(0.1);
+        }
+        let dt = (1.0 / SPS) as f32;
+        crate::psim::EngineDesc {
+            life: self.life,
+            producer: self.producer,
+            radius: self.radius,
+            anim: self.anim,
+            speed: self.speed,
+            gravity: self.gravity,
+            axis: norm3(self.axis),
+            extra: self.extra,
+            cone: (self.extra_angle.to_radians() * 0.5).tan().abs().min(20.0),
+            damp: (-drag * dt).exp(),
+            seed: self.seed,
+            flat: self.flat,
+        }
+    }
+}
+
+/// The state at layer time `ctx.time` from the host's particle backend (GPU particles), or
+/// `None` (simulate on the CPU).
+pub(super) fn accelerated(ctx: &EffectCtx, key: u64, phys: &Phys) -> Option<std::sync::Arc<PState>> {
+    let backend = ctx.env.host?.particles()?;
+    let steps = steps_at(ctx.time);
+    let births = crate::psim::births(phys.rate, steps, phys.max)?;
+    let req = crate::psim::SimRequest { key, steps, births: &births, system: crate::psim::ParticleSystem::Engine(phys.desc()) };
+    let parts = backend.simulate(&req)?;
+    Some(std::sync::Arc::new(PState {
+        parts: parts.into_iter().map(|q| Particle { p: q.p, v: q.v, age: q.age, life: q.life, rnd: q.rnd, id: q.id }).collect(),
+        carry: 0.0,
+        next_id: births.len() as u32,
+    }))
+}
+
+/// The live particles of a stepped particle effect (`ec.sim.ccparticleworld`,
+/// `ec.sim.ccparticlesystems2`) at `ctx.time`: from the host's particle backend when it has
+/// one (GPU particles), else from the CPU simulation. For comparing the two.
+pub fn particle_state(id: &str, ctx: &EffectCtx) -> Option<Vec<crate::psim::SimParticle>> {
+    let (phys, cache, salt) = match id {
+        "ec.sim.ccparticleworld" => (pw_phys(ctx), &PW_CACHE, 1),
+        "ec.sim.ccparticlesystems2" => (ps2_phys(ctx), &PS2_CACHE, 2),
+        _ => return None,
+    };
+    let key = sim_key(ctx, salt);
+    let st = accelerated(ctx, key, &phys).unwrap_or_else(|| simulate(cache, key, ctx.time, &phys));
+    Some(st.parts.iter().map(|q| crate::psim::SimParticle { p: q.p, v: q.v, age: q.age, life: q.life, rnd: q.rnd, id: q.id }).collect())
+}
+
+/// The simulation cache key of a stepped particle effect: every parameter but CC Particle World's
+/// Effect Camera, which only changes how the particles are seen (animating it doesn't restart
+/// the simulation).
+pub(super) fn sim_key(ctx: &EffectCtx, salt: u64) -> u64 {
+    params_key_except(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, salt, &[PW_EFFECT_CAMERA])
+}
+
+/// Run a particle system to layer time `t` through `cache`.
+pub(crate) fn simulate(cache: &SimCache<PState>, key: u64, t: f64, phys: &Phys) -> std::sync::Arc<PState> {
+    cache.run(key, steps_at(t), PState::default, |st, i| phys.step(st, i))
+}
+
+pub(crate) const PARTICLE_TYPES: &[&str] =
+    &["Line", "Shaded Sphere", "Faded Sphere", "Bubble", "Star", "Motion Polygon", "Tri-Polygon", "Cube", "Textured Square"];
+
+/// Colour/size/opacity of a particle at its age.
+pub(super) fn particle_look(q: &Particle, birth: [f32; 4], death: [f32; 4], bsize: f32, dsize: f32, svar: f32, max_op: f32) -> ([f32; 4], f32) {
+    let u = (q.age / q.life.max(1e-4)).clamp(0.0, 1.0);
+    let size = (bsize + (dsize - bsize) * u) * (1.0 + svar * (q.rnd * 2.0 - 1.0));
+    let fade = (u * 20.0).min(1.0) * ((1.0 - u) * 5.0).min(1.0);
+    let c = [birth[0] + (death[0] - birth[0]) * u, birth[1] + (death[1] - birth[1]) * u, birth[2] + (death[2] - birth[2]) * u, max_op * fade];
+    (c, size.max(0.0))
+}
+
+pub(super) fn type_sprite(kind: u32, x: f32, y: f32, r: f32, c: [f32; 4], velocity: [f32; 2], rot: f32) -> Sprite {
+    let [vx, vy] = velocity;
+    let vl = (vx * vx + vy * vy).sqrt().max(1e-6);
+    let shape = match kind {
+        0 => Shape::Line { dx: -vx / vl * r * 2.0, dy: -vy / vl * r * 2.0 },
+        1 => Shape::Sphere,
+        2 => Shape::Faded,
+        3 => Shape::Bubble,
+        4 => Shape::Star,
+        5 => Shape::Line { dx: -vx * 0.05, dy: -vy * 0.05 },
+        6 => Shape::Tri,
+        _ => Shape::Square,
+    };
+    let rr = match kind {
+        0 => (r * 0.08).max(0.5),
+        5 => r * 0.5,
+        _ => r,
+    };
+    Sprite { x, y, r: rr, c, shape, rot }
+}
+
+/// CC Particle World's Extras ▸ Effect Camera parameters (id prefix).
+pub(super) const PW_EFFECT_CAMERA: &str = "extras/effectCamera/";
diff --git a/crates/effects/src/sim/particle_fx.rs b/crates/effects/src/sim/particle_fx.rs
new file mode 100644
index 000000000..6b6c27b01
--- /dev/null
+++ b/crates/effects/src/sim/particle_fx.rs
@@ -0,0 +1,367 @@
+use super::engine::{PState, PW_EFFECT_CAMERA, Phys, accelerated, norm3, particle_look, sim_key, simulate, type_sprite};
+use super::sprites::{Acc, Post, Sprite, SpritePlan, raster, splat};
+use super::{Buf, EffectCtx, Image, IntoParallelRefIterator, ParallelIterator, SimCache, Value, params_key, unpremul};
+
+// ------------------------------------------------------------------ CC Particle World
+
+pub(super) static PW_CACHE: SimCache<PState> = SimCache::new(6);
+
+/// CC Particle World's physics.
+pub(super) fn pw_phys(ctx: &EffectCtx) -> Phys {
+    let pr = ctx.params;
+    Phys {
+        rate: pr.f("birthRate").max(0.0) * 120.0,
+        life: pr.f("longevity").max(0.0) as f32,
+        producer: [pr.f("producer/producerX") as f32, pr.f("producer/producerY") as f32, pr.f("producer/producerZ") as f32],
+        radius: [pr.f("producer/radiusX").max(0.0) as f32, pr.f("producer/radiusY").max(0.0) as f32, pr.f("producer/radiusZ").max(0.0) as f32],
+        anim: pr.e("physics/animation"),
+        speed: pr.f("physics/velocity") as f32 * 0.5,
+        gravity: {
+            let g = pr.f("physics/gravity") as f32;
+            let gv =
+                [pr.f("physics/gravityVector/gravityX") as f32, pr.f("physics/gravityVector/gravityY") as f32, pr.f("physics/gravityVector/gravityZ") as f32];
+            [gv[0] * g, gv[1] * g, gv[2] * g]
+        },
+        resistance: pr.f("physics/resistance").max(0.0) as f32,
+        axis: [pr.f("physics/directionAxis/axisX") as f32, pr.f("physics/directionAxis/axisY") as f32, pr.f("physics/directionAxis/axisZ") as f32],
+        extra: pr.f("physics/extra") as f32,
+        extra_angle: pr.f("physics/extraAngle") as f32,
+        seed: (pr.f("extras/randomSeed") as u32).wrapping_mul(0x9e3779b9) ^ ctx.seed,
+        max: 40_000,
+        flat: false,
+    }
+}
+
+pub(super) fn particle_world(ctx: &EffectCtx, b: Buf) -> Buf {
+    // #1195: with the comp's motion-blur shutter open, particles draw as motion trails: the
+    // sprite fields of samples across the shutter are averaged, as Transform averages its
+    // matrix samples. (The GPU compositor runs this case on the CPU: catalog::gpu_supported.)
+    if let Some((angle, phase, n)) = ctx.env.shutter.filter(|(a, _, _)| *a > 0.0) {
+        let n = (n.clamp(2, 64) as usize).max(2);
+        let fd = 1.0 / ctx.fps().max(0.001);
+        let mut acc = Image::new(b.img.width, b.img.height);
+        let mut post: Option<Post> = None;
+        for k in 0..n {
+            let t = ctx.time + (phase + angle * k as f64 / (n - 1) as f64) / 360.0 * fd;
+            let sub = EffectCtx { params: ctx.params, time: t, layer_size: ctx.layer_size, seed: ctx.seed, adjustment: ctx.adjustment, env: ctx.env };
+            if let Some(plan) = particle_world_plan(&sub, &b) {
+                let fx = splat(b.img.width, b.img.height, &plan.sprites, plan.acc);
+                acc.data.iter_mut().zip(&fx.data).for_each(|(a, o)| (0..4).for_each(|c| a[c] += o[c]));
+                post.get_or_insert(plan.post);
+            }
+        }
+        acc.data.iter_mut().for_each(|p| p.iter_mut().for_each(|v| *v /= n as f32));
+        return match post {
+            Some(p) => p.apply(b, acc),
+            None => b,
+        };
+    }
+    match particle_world_plan(ctx, &b) {
+        Some(plan) => plan.finish(b),
+        None => b,
+    }
+}
+
+/// Effect Camera ▸ FOV's default (degrees).
+pub(super) const PW_FOV: f64 = 50.0;
+
+/// What CC Particle World sees its particles through.
+enum PwCamera {
+    /// Extras ▸ Effect Camera, in world units (layer widths): `dist` from the world origin (the
+    /// layer centre) along −z, the world turned by `rot` (`None` = not turned) about the origin,
+    /// `focal` the scale at unit depth; particles nearer than `near` aren't drawn.
+    Effect { rot: Option<[[f32; 3]; 3]>, dist: f32, focal: f32, near: f32 },
+    /// The comp's active camera layer, on buffer-world points (After Effects then ignores the
+    /// Effect Camera).
+    Comp(crate::card3d::Proj),
+}
+
+/// A particle as the camera sees it: depth (larger is farther), buffer pixel, size scale `k`
+/// (buffer pixels per world unit = `k · layer width · buffer scale`) and velocity in world units
+/// on screen (× the same factor for buffer pixels).
+struct PwSeen {
+    depth: f32,
+    x: f32,
+    y: f32,
+    k: f32,
+    v: [f32; 2],
+}
+
+impl PwCamera {
+    fn new(ctx: &EffectCtx, b: &Buf) -> PwCamera {
+        let [lw, lh] = ctx.layer_size;
+        if let Some(cam) = ctx.env.host.and_then(|h| h.comp_scene()).filter(|sc| sc.camera_layer).and_then(|sc| sc.camera) {
+            let c = [b.offset[0] + lw * 0.5 * b.scale, b.offset[1] + lh * 0.5 * b.scale];
+            return PwCamera::Comp(crate::card3d::comp_proj(&cam, c, b));
+        }
+        let f = |id: &str, d: f64| ctx.params.get(&format!("{PW_EFFECT_CAMERA}{id}")).map(Value::as_f64).filter(|v| v.is_finite()).unwrap_or(d);
+        // The camera keeps the origin's plane at the scale Distance gives it as FOV changes
+        // (moving in for a wider view), so FOV sets how strong the perspective is. Distance 2
+        // shows the origin's plane at the layer's own scale.
+        let half = |fov: f64| (fov.clamp(1.0, 179.0).to_radians() * 0.5).tan();
+        let zoom = half(PW_FOV) / half(f("fov", PW_FOV));
+        let dist = f("distance", 2.0).max(0.01) * zoom;
+        let a = [f("rotationX", 0.0), f("rotationY", 0.0), f("rotationZ", 0.0)];
+        let rot = (a != [0.0; 3]).then(|| {
+            let r = crate::card3d::rot_ordered(a[0].to_radians(), a[1].to_radians(), a[2].to_radians(), 0);
+            r.map(|row| row.map(|v| v as f32))
+        });
+        PwCamera::Effect { rot, dist: dist as f32, focal: (2.0 * zoom) as f32, near: (0.025 * dist) as f32 }
+    }
+
+    /// How the camera sees world point `p` moving at `v`; `None` behind or too close to it.
+    fn see(&self, p: [f32; 3], v: [f32; 3], lw: f32, lh: f32, b: &Buf) -> Option<PwSeen> {
+        match self {
+            PwCamera::Effect { rot, dist, focal, near } => {
+                let turn = |r: &[[f32; 3]; 3], q: [f32; 3]| r.map(|row| row[0] * q[0] + row[1] * q[1] + row[2] * q[2]);
+                let (p, v) = match rot {
+                    Some(r) => (turn(r, p), turn(r, v)),
+                    None => (p, v),
+                };
+                let zc = dist + p[2];
+                if zc.is_nan() || zc <= *near {
+                    return None;
+                }
+                let k = focal / zc;
+                let (x, y) = b.to_px([(lw * 0.5 + p[0] * lw * k) as f64, (lh * 0.5 + p[1] * lw * k) as f64]);
+                Some(PwSeen { depth: zc, x: x as f32, y: y as f32, k, v: [v[0], v[1]] })
+            }
+            PwCamera::Comp(proj) => {
+                let (s, lw, lh) = (b.scale, lw as f64, lh as f64);
+                let u = lw * s;
+                let at = [b.offset[0] + lw * 0.5 * s + p[0] as f64 * u, b.offset[1] + lh * 0.5 * s + p[1] as f64 * u, p[2] as f64 * u];
+                let seen = proj.view(at, [v[0] as f64, v[1] as f64, v[2] as f64])?;
+                let k = seen.scale;
+                Some(PwSeen {
+                    depth: seen.depth as f32,
+                    x: seen.at[0] as f32,
+                    y: seen.at[1] as f32,
+                    k: k as f32,
+                    v: [(seen.vel[0] / k) as f32, (seen.vel[1] / k) as f32],
+                })
+            }
+        }
+    }
+}
+
+/// CC Particle World's sprites (far to near), `None` before anything is born.
+pub(super) fn particle_world_plan(ctx: &EffectCtx, b: &Buf) -> Option<SpritePlan> {
+    let pr = ctx.params;
+    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
+    let phys = pw_phys(ctx);
+    if phys.rate <= 0.0 && ctx.time <= 0.0 {
+        return None;
+    }
+    let key = sim_key(ctx, 1);
+    let st = accelerated(ctx, key, &phys).unwrap_or_else(|| simulate(&PW_CACHE, key, ctx.time, &phys));
+    let kind = pr.e("particle/particleType");
+    let birth = pr.color("particle/birthColor");
+    let death = pr.color("particle/deathColor");
+    let (bs, ds) = (pr.f("particle/birthSize") as f32, pr.f("particle/deathSize") as f32);
+    let svar = pr.f("particle/sizeVariation") as f32 / 100.0;
+    let max_op = pr.f("particle/maxOpacity") as f32 / 100.0;
+    let s = b.scale as f32;
+    let cam = PwCamera::new(ctx, b);
+    let mut list: Vec<(f32, Sprite)> = st
+        .parts
+        .par_iter()
+        .filter_map(|q| {
+            let PwSeen { depth, x, y, k, v } = cam.see(q.p, q.v, lw, lh, b)?;
+            let (c, size) = particle_look(q, birth, death, bs, ds, svar, max_op);
+            let r = size * 0.5 * lw * k * s * 0.25;
+            let sp = type_sprite(kind, x, y, r, c, [v[0] * lw * k * s, v[1] * lw * k * s], (q.id % 628) as f32 * 0.01 + q.age * 2.0);
+            Some((depth, sp))
+        })
+        .collect();
+    list.sort_by(|a, b| b.0.total_cmp(&a.0));
+    let sprites: Vec<Sprite> = list.into_iter().map(|(_, s)| s).collect();
+    Some(particle_sprites(sprites, pr.e("particle/transferMode")))
+}
+
+/// The CC particle systems' sprites with their Transfer Mode (Composite, Screen, Add, Black
+/// Background).
+fn particle_sprites(sprites: Vec<Sprite>, mode: u32) -> SpritePlan {
+    // The particles replace the layer (After Effects shows no trace of the source in any
+    // Transfer Mode, which sets how the particles meet each other).
+    SpritePlan { sprites, tints: vec![], acc: if mode == 2 { Acc::Add } else { Acc::Over }, post: Post::Replace }
+}
+
+// ------------------------------------------------------------------ CC Particle Systems II
+
+pub(super) static PS2_CACHE: SimCache<PState> = SimCache::new(6);
+
+/// CC Particle Systems II's physics.
+pub(super) fn ps2_phys(ctx: &EffectCtx) -> Phys {
+    let pr = ctx.params;
+    let lh = ctx.layer_size[1] as f32;
+    let unit = lh.max(1.0);
+    let pos = pr.v2("producer/position");
+    let dir = (pr.f("physics/direction") as f32).to_radians();
+    Phys {
+        rate: pr.f("birthRate").max(0.0) * 60.0,
+        life: pr.f("longevity").max(0.0) as f32,
+        producer: [pos[0] as f32 / unit, pos[1] as f32 / unit, 0.0],
+        radius: [pr.f("producer/radiusX").max(0.0) as f32 / unit, pr.f("producer/radiusY").max(0.0) as f32 / unit, 0.0],
+        anim: [0u32, 1, 2, 3, 4, 5, 6, 7, 8, 9][pr.e("physics/animation").min(9) as usize],
+        speed: pr.f("physics/velocity") as f32 * 0.25,
+        gravity: [0.0, pr.f("physics/gravity") as f32 * 0.5, 0.0],
+        resistance: pr.f("physics/resistance").max(0.0) as f32,
+        // AE angles: 0° = up, clockwise.
+        axis: [dir.sin(), -dir.cos(), 0.0],
+        extra: pr.f("physics/extra") as f32,
+        extra_angle: 45.0 * pr.f("physics/extra") as f32,
+        seed: (pr.f("randomSeed") as u32).wrapping_mul(0x85ebca6b) ^ ctx.seed,
+        max: 40_000,
+        flat: true,
+    }
+}
+
+pub(super) fn particle_systems2(ctx: &EffectCtx, b: Buf) -> Buf {
+    particle_systems2_plan(ctx, &b).finish(b)
+}
+
+/// CC Particle Systems II's sprites.
+pub(super) fn particle_systems2_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
+    let pr = ctx.params;
+    let lh = ctx.layer_size[1] as f32;
+    let unit = lh.max(1.0);
+    let phys = ps2_phys(ctx);
+    let key = sim_key(ctx, 2);
+    let st = accelerated(ctx, key, &phys).unwrap_or_else(|| simulate(&PS2_CACHE, key, ctx.time, &phys));
+    let kind = pr.e("particle/particleType");
+    let birth = pr.color("particle/birthColor");
+    let death = pr.color("particle/deathColor");
+    let (bs, ds) = (pr.f("particle/birthSize") as f32, pr.f("particle/deathSize") as f32);
+    let svar = pr.f("particle/sizeVariation") as f32 / 100.0;
+    let max_op = pr.f("particle/maxOpacity") as f32 / 100.0;
+    let s = b.scale as f32;
+    let sprites: Vec<Sprite> = st
+        .parts
+        .iter()
+        .map(|q| {
+            let (bx, by) = b.to_px([(q.p[0] * unit) as f64, (q.p[1] * unit) as f64]);
+            let (c, size) = particle_look(q, birth, death, bs, ds, svar, max_op);
+            let r = size * unit * 0.02 * s;
+            type_sprite(kind, bx as f32, by as f32, r, c, [q.v[0] * unit * s, q.v[1] * unit * s], (q.id % 628) as f32 * 0.01 + q.age * 2.0)
+        })
+        .collect();
+    particle_sprites(sprites, pr.e("particle/transferMode"))
+}
+
+// ------------------------------------------------------------------ CC Mr. Mercury
+
+static MERCURY_CACHE: SimCache<PState> = SimCache::new(6);
+
+/// A CC Mr. Mercury blob (buffer px).
+#[derive(Clone, Copy, Debug)]
+pub struct Blob {
+    pub x: f32,
+    pub y: f32,
+    pub r: f32,
+}
+
+/// CC Mr. Mercury's blobs this frame, from its particle simulation (for buffer geometry `b`).
+pub fn mercury_blobs(ctx: &EffectCtx, b: &Buf) -> Vec<Blob> {
+    let pr = ctx.params;
+    let lh = ctx.layer_size[1] as f32;
+    let unit = lh.max(1.0);
+    let pos = pr.v2("producer");
+    let dir = (pr.f("direction") as f32).to_radians();
+    let phys = Phys {
+        rate: pr.f("birthRate").max(0.0) * 10.0,
+        life: pr.f("longevity").max(0.0) as f32,
+        producer: [pos[0] as f32 / unit, pos[1] as f32 / unit, 0.0],
+        radius: [pr.f("radiusX").max(0.0) as f32 / unit, pr.f("radiusY").max(0.0) as f32 / unit, 0.0],
+        anim: [0u32, 1, 2, 3, 4, 5, 6, 7, 8, 9][pr.e("animation").min(9) as usize],
+        speed: pr.f("velocity") as f32 * 0.3,
+        gravity: [0.0, pr.f("gravity") as f32 * 0.5, 0.0],
+        resistance: pr.f("resistance").max(0.0) as f32,
+        axis: [dir.sin(), -dir.cos(), 0.0],
+        extra: pr.f("extra") as f32,
+        extra_angle: 45.0 * pr.f("extra") as f32,
+        seed: ctx.seed.wrapping_mul(0xc2b2ae35),
+        max: 4_000,
+        flat: true,
+    };
+    let st = simulate(&MERCURY_CACHE, params_key(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, 3), ctx.time, &phys);
+    let (bs, ds) = (pr.f("blobBirthSize") as f32, pr.f("blobDeathSize") as f32);
+    let s = b.scale as f32;
+    st.parts
+        .iter()
+        .map(|q| {
+            let u = (q.age / q.life.max(1e-4)).clamp(0.0, 1.0);
+            let size = bs + (ds - bs) * u;
+            let (bx, by) = b.to_px([(q.p[0] * unit) as f64, (q.p[1] * unit) as f64]);
+            Blob { x: bx as f32, y: by as f32, r: (size * unit * 0.08 * s).max(0.0) }
+        })
+        .filter(|q| q.r > 0.1)
+        .collect()
+}
+
+pub(super) fn mr_mercury(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let pr = ctx.params;
+    let blobs = mercury_blobs(ctx, &b);
+    let influence = pr.f("blobInfluence") as f32 / 100.0;
+    let s = b.scale as f32;
+    let (w, hh) = (b.img.width, b.img.height);
+    // Field and gradient accumulate additively: [f, gx, gy, _].
+    let mut field = Image::new(w, hh);
+    let infl = 1.0 + influence;
+    raster(
+        &mut field,
+        &blobs,
+        |q| {
+            let e = q.r * 2.0 * infl;
+            Some([q.x - e, q.y - e, q.x + e, q.y + e])
+        },
+        |q, x, y| {
+            let (dx, dy) = (x - q.x, y - q.y);
+            let rr = q.r * 2.0 * infl;
+            let d2 = (dx * dx + dy * dy) / (rr * rr);
+            if d2 >= 1.0 {
+                return None;
+            }
+            let k = 1.0 - d2;
+            let f = k * k * k;
+            let g = -6.0 * k * k / (rr * rr);
+            Some([f, g * dx, g * dy, 0.0])
+        },
+        Acc::Add,
+    );
+    let thr = 0.35f32;
+    let ambient = pr.f("shading/ambient") as f32 / 100.0;
+    let diffuse = pr.f("shading/diffuse") as f32 / 100.0;
+    let specular = pr.f("shading/specular") as f32 / 100.0;
+    let rough = pr.f("shading/roughness").max(0.001) as f32;
+    let metal = pr.f("shading/metal") as f32 / 100.0;
+    let li = pr.f("light/lightIntensity") as f32 / 100.0;
+    let lc = pr.color("light/lightColor");
+    let ldir = (pr.f("light/lightDirection") as f32).to_radians();
+    let lheight = pr.f("light/lightHeight") as f32 / 100.0;
+    let l = norm3([ldir.sin(), -ldir.cos(), lheight.max(0.05)]);
+    let src = b.img.clone();
+    let mut out = Image::new(w, hh);
+    out.rows_mut().for_each(|(y, row)| {
+        for (x, px) in row.iter_mut().enumerate() {
+            let fv = field.data[y * w as usize + x];
+            let f = fv[0];
+            if f <= thr * 0.8 {
+                continue;
+            }
+            let cov = ((f - thr * 0.8) / (thr * 0.4)).clamp(0.0, 1.0);
+            let n = norm3([fv[1] * 3.0, fv[2] * 3.0, 1.0 / (1.0 + f)]);
+            // Refract the layer through the blob.
+            let sp = src.sample_bilinear_clamped(x as f64 + 0.5 - n[0] as f64 * 12.0 * s as f64, y as f64 + 0.5 - n[1] as f64 * 12.0 * s as f64);
+            let (c, sa) = unpremul(sp);
+            let base = if sa > 0.0 { c } else { [0.7, 0.7, 0.75] };
+            let nl = (n[0] * l[0] + n[1] * l[1] + n[2] * l[2]).max(0.0);
+            let hv = norm3([l[0], l[1], l[2] + 1.0]);
+            let spec = (n[0] * hv[0] + n[1] * hv[1] + n[2] * hv[2]).max(0.0).powf(1.0 / rough) * specular * li;
+            let shade = ambient + diffuse * nl * li;
+            let cc: [f32; 3] = std::array::from_fn(|k| base[k] * shade + spec * (lc[k] * (1.0 - metal) + base[k] * metal));
+            *px = [cc[0] * cov, cc[1] * cov, cc[2] * cov, cov];
+        }
+    });
+    b.img = out;
+    b
+}
diff --git a/crates/effects/src/sim/registry.rs b/crates/effects/src/sim/registry.rs
new file mode 100644
index 000000000..f29eb2653
--- /dev/null
+++ b/crates/effects/src/sim/registry.rs
@@ -0,0 +1,229 @@
+use super::common::{pct, pt, spec};
+use super::engine::{PARTICLE_TYPES, PW_ANIMS};
+use super::particle_fx::{PW_FOV, mr_mercury, particle_systems2, particle_systems2_plan, particle_world, particle_world_plan};
+use super::sprites::SpritePlan;
+use super::weather::{bubbles, drizzle, rainfall, rainfall_plan, snowfall, snowfall_plan, star_burst, star_burst_plan};
+use super::{Buf, EffectCtx, EffectSpec, ParamUi, Value, col, num, p, popup, slider};
+
+/// The sprite plan of a sprite-drawing simulation effect for buffer geometry `b` (its pixels
+/// are not read), `None` for other effects or settings drawn otherwise (the GPU compositor's
+/// render pass).
+pub fn sprite_plan(id: &str, ctx: &EffectCtx, b: &Buf) -> Option<SpritePlan> {
+    match id {
+        "ec.sim.ccrainfall" => Some(rainfall_plan(ctx, b)),
+        "ec.sim.ccsnowfall" => Some(snowfall_plan(ctx, b)),
+        "ec.sim.ccstarburst" => Some(star_burst_plan(ctx, b)),
+        "ec.sim.cchair" => crate::sim3::hair_plan(ctx, b),
+        "ec.sim.waveworld" => crate::sim2::wave_world_plan(ctx, b).and_then(|p| match p {
+            crate::sim2::WavePlan::Wire(sp) => Some(sp),
+            crate::sim2::WavePlan::Height { .. } => None,
+        }),
+        "ec.sim.foam" => crate::sim2::foam_plan(ctx, b),
+        "ec.sim.ccparticleworld" => particle_world_plan(ctx, b),
+        "ec.sim.ccparticlesystems2" => Some(particle_systems2_plan(ctx, b)),
+        _ => None,
+    }
+}
+
+// ------------------------------------------------------------------ specs
+
+pub fn specs() -> Vec<EffectSpec> {
+    let transfer = || popup(&["Composite", "Lighten"]);
+    vec![
+        spec(
+            "ec.sim.ccrainfall",
+            "CC Rainfall",
+            vec![
+                p("drops", "Drops", num(5000.0), slider(0.0, 100_000.0, 0.0, 20_000.0, 0)),
+                p("size", "Size", num(1.0), slider(0.0, 50.0, 0.0, 10.0, 2)),
+                p("sceneDepth", "Scene Depth", num(5000.0), slider(0.0, 20_000.0, 0.0, 10_000.0, 0)),
+                p("speed", "Speed", num(4000.0), slider(0.0, 20_000.0, 0.0, 10_000.0, 0)),
+                p("wind", "Wind", num(0.0), slider(-10_000.0, 10_000.0, -2000.0, 2000.0, 1)),
+                p("windVariation", "Variation % (Wind)", num(0.0), pct()),
+                p("spread", "Spread", num(0.0), slider(0.0, 1000.0, 0.0, 100.0, 1)),
+                p("color", "Color", col(0.8, 0.8, 0.8), ParamUi::Color),
+                p("opacity", "Opacity", num(25.0), pct()),
+                p("transferMode", "Transfer Mode", Value::Enum(1), transfer()),
+                p("compositeWithOriginal", "Composite With Original", Value::Bool(true), ParamUi::Checkbox),
+                p("extras/appearance", "Appearance", Value::Enum(0), popup(&["Refracting", "Soft Solid"])),
+                p("extras/offset", "Offset", pt(0.5, 0.5), ParamUi::Point),
+                p("extras/randomSeed", "Random Seed", num(0.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
+            ],
+            rainfall,
+        ),
+        spec(
+            "ec.sim.ccsnowfall",
+            "CC Snowfall",
+            vec![
+                p("flakes", "Flakes", num(10_000.0), slider(0.0, 200_000.0, 0.0, 50_000.0, 0)),
+                p("size", "Size", num(3.0), slider(0.0, 50.0, 0.0, 20.0, 2)),
+                p("sizeVariation", "Variation % (Size)", num(50.0), pct()),
+                p("sceneDepth", "Scene Depth", num(5000.0), slider(0.0, 20_000.0, 0.0, 10_000.0, 0)),
+                p("speed", "Speed", num(100.0), slider(0.0, 5000.0, 0.0, 1000.0, 1)),
+                p("speedVariation", "Variation % (Speed)", num(50.0), pct()),
+                p("wind", "Wind", num(25.0), slider(-5000.0, 5000.0, -500.0, 500.0, 1)),
+                p("windVariation", "Variation % (Wind)", num(50.0), pct()),
+                p("spread", "Spread", num(0.0), slider(0.0, 1000.0, 0.0, 100.0, 1)),
+                p("wiggle/wiggleAmount", "Amount", num(2.0), slider(0.0, 100.0, 0.0, 20.0, 2)),
+                p("wiggle/wiggleAmountVariation", "Variation % (Amount)", num(50.0), pct()),
+                p("wiggle/wiggleFrequency", "Frequency", num(1.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
+                p("wiggle/wiggleFrequencyVariation", "Variation % (Frequency)", num(50.0), pct()),
+                p("color", "Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("opacity", "Opacity", num(100.0), pct()),
+                p("transferMode", "Transfer Mode", Value::Enum(0), transfer()),
+                p("compositeWithOriginal", "Composite With Original", Value::Bool(true), ParamUi::Checkbox),
+                p("extras/offset", "Offset", pt(0.5, 0.5), ParamUi::Point),
+                p("extras/randomSeed", "Random Seed", num(0.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
+            ],
+            snowfall,
+        ),
+        spec(
+            "ec.sim.ccbubbles",
+            "CC Bubbles",
+            vec![
+                p("bubbleAmount", "Bubble Amount", num(100.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
+                p("bubbleSpeed", "Bubble Speed", num(0.5), slider(-10.0, 10.0, -2.0, 2.0, 2)),
+                p("wobbleAmplitude", "Wobble Amplitude", num(5.0), slider(0.0, 500.0, 0.0, 100.0, 1)),
+                p("wobbleFrequency", "Wobble Frequency", num(1.0), slider(0.0, 50.0, 0.0, 10.0, 2)),
+                p("bubbleSize", "Bubble Size", num(1.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
+                p("reflectionType", "Reflection Type", Value::Enum(0), popup(&["Liquid", "Metal"])),
+                p("shadingType", "Shading Type", Value::Enum(0), popup(&["None", "Lighten", "Darken", "Fade Inwards", "Fade Outwards"])),
+            ],
+            bubbles,
+        ),
+        spec(
+            "ec.sim.ccdrizzle",
+            "CC Drizzle",
+            vec![
+                p("dripRate", "Drip Rate", num(10.0), slider(0.0, 200.0, 0.0, 50.0, 2)),
+                p("longevity", "Longevity (sec)", num(1.0), slider(0.0, 30.0, 0.0, 5.0, 2)),
+                p("rippling", "Rippling", num(360.0), ParamUi::Angle),
+                p("displacement", "Displacement", num(5.0), slider(0.0, 100.0, 0.0, 30.0, 2)),
+                p("rippleHeight", "Ripple Height", num(30.0), slider(0.0, 200.0, 0.0, 100.0, 1)),
+                p("spreading", "Spreading", num(100.0), slider(0.0, 1000.0, 0.0, 300.0, 1)),
+                p("light/lightIntensity", "Light Intensity", num(100.0), slider(0.0, 400.0, 0.0, 200.0, 1)),
+                p("light/lightColor", "Light Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("light/lightHeight", "Light Height", num(25.0), slider(-100.0, 100.0, -100.0, 100.0, 1)),
+                p("light/lightDirection", "Light Direction", num(-45.0), ParamUi::Angle),
+                p("shading/ambient", "Ambient", num(0.0), slider(-200.0, 200.0, -100.0, 100.0, 1)),
+                p("shading/diffuse", "Diffuse", num(0.0), slider(0.0, 200.0, 0.0, 100.0, 1)),
+                p("shading/specular", "Specular", num(20.0), slider(0.0, 200.0, 0.0, 100.0, 1)),
+                p("shading/roughness", "Roughness", num(0.05), slider(0.001, 1.0, 0.001, 0.5, 3)),
+            ],
+            drizzle,
+        ),
+        spec(
+            "ec.sim.ccstarburst",
+            "CC Star Burst",
+            vec![
+                p("scatter", "Scatter", num(100.0), slider(0.0, 1000.0, 0.0, 300.0, 1)),
+                p("speed", "Speed", num(1.0), slider(-10.0, 10.0, -4.0, 4.0, 2)),
+                p("phase", "Phase", num(0.0), ParamUi::Angle),
+                p("gridSpacing", "Grid Spacing", num(2.0), slider(1.0, 100.0, 1.0, 20.0, 0)),
+                p("size", "Size", num(100.0), slider(0.0, 1000.0, 0.0, 300.0, 1)),
+                p("blendWithOriginal", "Blend w. Original", num(0.0), pct()),
+            ],
+            star_burst,
+        ),
+        spec(
+            "ec.sim.ccparticleworld",
+            "CC Particle World",
+            vec![
+                p("birthRate", "Birth Rate", num(0.5), slider(0.0, 100.0, 0.0, 10.0, 2)),
+                p("longevity", "Longevity (sec)", num(1.0), slider(0.0, 100.0, 0.0, 10.0, 2)),
+                p("producer/producerX", "Position X", num(0.0), slider(-10.0, 10.0, -1.0, 1.0, 2)),
+                p("producer/producerY", "Position Y", num(0.0), slider(-10.0, 10.0, -1.0, 1.0, 2)),
+                p("producer/producerZ", "Position Z", num(0.0), slider(-10.0, 10.0, -1.0, 1.0, 2)),
+                p("producer/radiusX", "Radius X", num(0.025), slider(0.0, 10.0, 0.0, 1.0, 3)),
+                p("producer/radiusY", "Radius Y", num(0.025), slider(0.0, 10.0, 0.0, 1.0, 3)),
+                p("producer/radiusZ", "Radius Z", num(0.025), slider(0.0, 10.0, 0.0, 1.0, 3)),
+                p("physics/animation", "Animation", Value::Enum(0), popup(PW_ANIMS)),
+                p("physics/velocity", "Velocity", num(1.0), slider(-10.0, 10.0, 0.0, 5.0, 2)),
+                p("physics/inheritVelocity", "Inherit Velocity %", num(0.0), slider(-100.0, 100.0, -100.0, 100.0, 1)),
+                p("physics/gravity", "Gravity", num(0.5), slider(-10.0, 10.0, -2.0, 2.0, 3)),
+                p("physics/resistance", "Resistance", num(0.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
+                p("physics/extra", "Extra", num(1.0), slider(0.0, 10.0, 0.0, 2.0, 2)),
+                p("physics/extraAngle", "Extra Angle", num(360.0), ParamUi::Angle),
+                p("physics/directionAxis/axisX", "Axis X", num(0.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
+                p("physics/directionAxis/axisY", "Axis Y", num(-1.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
+                p("physics/directionAxis/axisZ", "Axis Z", num(0.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
+                p("physics/gravityVector/gravityX", "Gravity X", num(0.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
+                p("physics/gravityVector/gravityY", "Gravity Y", num(1.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
+                p("physics/gravityVector/gravityZ", "Gravity Z", num(0.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
+                p("particle/particleType", "Particle Type", Value::Enum(0), popup(PARTICLE_TYPES)),
+                p("particle/birthSize", "Birth Size", num(0.2), slider(0.0, 10.0, 0.0, 1.0, 3)),
+                p("particle/deathSize", "Death Size", num(0.2), slider(0.0, 10.0, 0.0, 1.0, 3)),
+                p("particle/sizeVariation", "Size Variation", num(0.0), pct()),
+                p("particle/maxOpacity", "Max Opacity", num(75.0), pct()),
+                p("particle/birthColor", "Birth Color", col(1.0, 1.0, 0.0), ParamUi::Color),
+                p("particle/deathColor", "Death Color", col(0.6, 0.0, 0.0), ParamUi::Color),
+                p("particle/transferMode", "Transfer Mode", Value::Enum(0), popup(&["Composite", "Screen", "Add", "Black Matte"])),
+                p("extras/effectCamera/distance", "Distance", num(2.0), slider(0.0, 100.0, 0.0, 10.0, 2)),
+                p("extras/effectCamera/rotationX", "Rotation X", num(0.0), ParamUi::Angle),
+                p("extras/effectCamera/rotationY", "Rotation Y", num(0.0), ParamUi::Angle),
+                p("extras/effectCamera/rotationZ", "Rotation Z", num(0.0), ParamUi::Angle),
+                p("extras/effectCamera/fov", "FOV", num(PW_FOV), slider(1.0, 179.0, 10.0, 120.0, 1)),
+                p("extras/randomSeed", "Random Seed", num(0.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
+            ],
+            particle_world,
+        ),
+        spec(
+            "ec.sim.ccparticlesystems2",
+            "CC Particle Systems II",
+            vec![
+                p("birthRate", "Birth Rate", num(2.0), slider(0.0, 100.0, 0.0, 20.0, 2)),
+                p("longevity", "Longevity (sec)", num(1.0), slider(0.0, 100.0, 0.0, 10.0, 2)),
+                p("producer/position", "Position", pt(0.5, 0.5), ParamUi::Point),
+                p("producer/radiusX", "Radius X", num(0.0), slider(0.0, 2000.0, 0.0, 200.0, 1)),
+                p("producer/radiusY", "Radius Y", num(0.0), slider(0.0, 2000.0, 0.0, 200.0, 1)),
+                p("physics/animation", "Animation", Value::Enum(0), popup(PW_ANIMS)),
+                p("physics/velocity", "Velocity", num(2.0), slider(-20.0, 20.0, 0.0, 10.0, 2)),
+                p("physics/inheritVelocity", "Inherit Velocity %", num(0.0), slider(-100.0, 100.0, -100.0, 100.0, 1)),
+                p("physics/gravity", "Gravity", num(1.0), slider(-20.0, 20.0, -5.0, 5.0, 2)),
+                p("physics/resistance", "Resistance", num(0.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
+                p("physics/direction", "Direction", num(0.0), ParamUi::Angle),
+                p("physics/extra", "Extra", num(1.0), slider(0.0, 10.0, 0.0, 2.0, 2)),
+                p("particle/particleType", "Particle Type", Value::Enum(0), popup(PARTICLE_TYPES)),
+                p("particle/birthSize", "Birth Size", num(0.5), slider(0.0, 20.0, 0.0, 5.0, 2)),
+                p("particle/deathSize", "Death Size", num(1.5), slider(0.0, 20.0, 0.0, 5.0, 2)),
+                p("particle/sizeVariation", "Size Variation", num(0.0), pct()),
+                p("particle/maxOpacity", "Max Opacity", num(75.0), pct()),
+                p("particle/birthColor", "Birth Color", col(1.0, 1.0, 0.0), ParamUi::Color),
+                p("particle/deathColor", "Death Color", col(0.6, 0.0, 0.0), ParamUi::Color),
+                p("particle/transferMode", "Transfer Mode", Value::Enum(0), popup(&["Composite", "Screen", "Add", "Black Matte"])),
+                p("randomSeed", "Random Seed", num(0.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
+            ],
+            particle_systems2,
+        ),
+        spec(
+            "ec.sim.ccmrmercury",
+            "CC Mr. Mercury",
+            vec![
+                p("radiusX", "Radius X", num(50.0), slider(0.0, 2000.0, 0.0, 300.0, 1)),
+                p("radiusY", "Radius Y", num(50.0), slider(0.0, 2000.0, 0.0, 300.0, 1)),
+                p("producer", "Producer", pt(0.5, 0.5), ParamUi::Point),
+                p("direction", "Direction", num(0.0), ParamUi::Angle),
+                p("velocity", "Velocity", num(1.0), slider(-20.0, 20.0, 0.0, 5.0, 2)),
+                p("birthRate", "Birth Rate", num(1.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
+                p("longevity", "Longevity (sec)", num(2.0), slider(0.0, 100.0, 0.0, 10.0, 2)),
+                p("gravity", "Gravity", num(0.5), slider(-20.0, 20.0, -5.0, 5.0, 2)),
+                p("resistance", "Resistance", num(0.0), slider(0.0, 20.0, 0.0, 5.0, 2)),
+                p("extra", "Extra", num(1.0), slider(0.0, 10.0, 0.0, 2.0, 2)),
+                p("animation", "Animation", Value::Enum(0), popup(PW_ANIMS)),
+                p("blobInfluence", "Blob Influence", num(100.0), slider(0.0, 400.0, 0.0, 200.0, 1)),
+                p("blobBirthSize", "Blob Birth Size", num(0.5), slider(0.0, 10.0, 0.0, 2.0, 2)),
+                p("blobDeathSize", "Blob Death Size", num(0.25), slider(0.0, 10.0, 0.0, 2.0, 2)),
+                p("light/lightIntensity", "Light Intensity", num(100.0), slider(0.0, 400.0, 0.0, 200.0, 1)),
+                p("light/lightColor", "Light Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("light/lightHeight", "Light Height", num(50.0), slider(-100.0, 100.0, -100.0, 100.0, 1)),
+                p("light/lightDirection", "Light Direction", num(-45.0), ParamUi::Angle),
+                p("shading/ambient", "Ambient", num(0.0), slider(-200.0, 200.0, -100.0, 100.0, 1)),
+                p("shading/diffuse", "Diffuse", num(75.0), slider(0.0, 200.0, 0.0, 100.0, 1)),
+                p("shading/specular", "Specular", num(50.0), slider(0.0, 200.0, 0.0, 100.0, 1)),
+                p("shading/roughness", "Roughness", num(0.05), slider(0.001, 1.0, 0.001, 0.5, 3)),
+                p("shading/metal", "Metal", num(100.0), pct()),
+            ],
+            mr_mercury,
+        ),
+    ]
+}
diff --git a/crates/effects/src/sim/sprites.rs b/crates/effects/src/sim/sprites.rs
new file mode 100644
index 000000000..78c405abd
--- /dev/null
+++ b/crates/effects/src/sim/sprites.rs
@@ -0,0 +1,361 @@
+use super::{Buf, Image, IndexedParallelIterator, IntoParallelRefIterator, IntoParallelRefMutIterator, ParallelIterator, ParallelSliceMut, Px, unpremul};
+
+// ------------------------------------------------------------------ band rasteriser
+
+const BAND: usize = 16;
+
+/// How rasterised items combine with what is already in the target.
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub enum Acc {
+    /// Premultiplied "over" (later items on top).
+    Over,
+    /// Additive (glows, light).
+    Add,
+}
+
+/// Rasterise many small items into `img` (buffer pixels). `bbox` gives an item's pixel bounds
+/// `[x0, y0, x1, y1]` (or `None` to skip), `shade` its premultiplied colour at a pixel centre.
+/// Items are bucketed into horizontal bands rendered in parallel; within a band they are drawn
+/// in slice order.
+pub(crate) fn raster<T: Sync>(
+    img: &mut Image,
+    items: &[T],
+    bbox: impl Fn(&T) -> Option<[f32; 4]> + Sync,
+    shade: impl Fn(&T, f32, f32) -> Option<Px> + Sync,
+    acc: Acc,
+) {
+    let (w, hgt) = (img.width as usize, img.height as usize);
+    if w == 0 || hgt == 0 || items.is_empty() {
+        return;
+    }
+    let nb = hgt.div_ceil(BAND);
+    let boxes: Vec<Option<[i32; 4]>> = items
+        .par_iter()
+        .map(|it| {
+            let b = bbox(it)?;
+            if !(b[0].is_finite() && b[1].is_finite() && b[2].is_finite() && b[3].is_finite()) {
+                return None;
+            }
+            let x0 = b[0].floor().max(0.0) as i32;
+            let y0 = b[1].floor().max(0.0) as i32;
+            let x1 = (b[2].ceil() as i32).min(w as i32 - 1);
+            let y1 = (b[3].ceil() as i32).min(hgt as i32 - 1);
+            if x1 < x0 || y1 < y0 || b[2] < 0.0 || b[3] < 0.0 {
+                return None;
+            }
+            Some([x0, y0, x1, y1])
+        })
+        .collect();
+    let mut buckets: Vec<Vec<u32>> = vec![Vec::new(); nb];
+    for (i, b) in boxes.iter().enumerate() {
+        if let Some(b) = b {
+            for band in (b[1] as usize / BAND)..=(b[3] as usize / BAND).min(nb - 1) {
+                buckets[band].push(i as u32);
+            }
+        }
+    }
+    img.data.par_chunks_mut(w * BAND).enumerate().for_each(|(band, chunk)| {
+        let by0 = band * BAND;
+        let rows = chunk.len() / w;
+        for &i in &buckets[band] {
+            let Some(b) = boxes[i as usize] else { continue };
+            let it = &items[i as usize];
+            let ya = (b[1] as usize).max(by0);
+            let yb = (b[3] as usize).min(by0 + rows - 1);
+            for y in ya..=yb {
+                let row = &mut chunk[(y - by0) * w..(y - by0 + 1) * w];
+                for x in b[0] as usize..=b[2] as usize {
+                    if let Some(c) = shade(it, x as f32 + 0.5, y as f32 + 0.5) {
+                        let d = &mut row[x];
+                        match acc {
+                            Acc::Over => {
+                                let k = 1.0 - c[3];
+                                *d = [c[0] + d[0] * k, c[1] + d[1] * k, c[2] + d[2] * k, c[3] + d[3] * k];
+                            }
+                            Acc::Add => {
+                                *d = [d[0] + c[0], d[1] + c[1], d[2] + c[2], (d[3] + c[3]).min(1.0)];
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    });
+}
+
+// ------------------------------------------------------------------ sprites
+
+#[derive(Clone, Copy, PartialEq, Debug)]
+pub enum Shape {
+    /// Soft round dot (Gaussian-like falloff).
+    Soft,
+    /// Hard anti-aliased disc.
+    Disc,
+    /// Lit sphere (upper-left light, specular).
+    Sphere,
+    /// Disc fading linearly to its rim.
+    Faded,
+    /// Thin ring with a highlight.
+    Bubble,
+    /// Four-point star.
+    Star,
+    /// Rotated square (angle in `rot`).
+    Square,
+    /// Triangle (angle in `rot`).
+    Tri,
+    /// Segment from (x, y) by (dx, dy), half-width `r`.
+    Line { dx: f32, dy: f32 },
+}
+
+/// A particle sprite in buffer pixels; `c` is straight colour + opacity.
+#[derive(Clone, Copy, Debug)]
+pub struct Sprite {
+    pub x: f32,
+    pub y: f32,
+    pub r: f32,
+    pub c: [f32; 4],
+    pub shape: Shape,
+    pub rot: f32,
+}
+
+impl Sprite {
+    pub(crate) fn new(x: f32, y: f32, r: f32, c: [f32; 4], shape: Shape) -> Sprite {
+        Sprite { x, y, r, c, shape, rot: 0.0 }
+    }
+}
+
+/// Where a sprite's colour comes from when it depends on the layer's pixels (resolved by
+/// [`SpritePlan::resolve`] on the CPU, per pixel by the GPU compositor). Positions are buffer
+/// pixels.
+#[derive(Clone, Copy, Debug)]
+pub enum Tint {
+    /// The sprite's own colour.
+    Fixed,
+    /// CC Rainfall's refracting drops: where the layer shows (alpha > 0), colour × (layer
+    /// colour × 0.6 + 0.5) sampled at (x, y).
+    Refract { x: f64, y: f64 },
+    /// CC Star Burst: the layer's colour at (x, y), opacity × its alpha (none where clear).
+    Source { x: f64, y: f64 },
+    /// CC Hair: the root's colour at (x, y) mixed with the hair colour (`inherit` = 1 keeps the
+    /// root's), × `shade`, + `spec`; no strand where the root's alpha is below ½.
+    Root { x: f64, y: f64, hair: [f32; 3], inherit: f32, shade: f32, spec: f32 },
+}
+
+/// How a sprite layer meets the original layer.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum Post {
+    /// `combine` with this mode (0 Composite … 5 sprites only).
+    Combine(u32),
+    /// The sprites alone.
+    Replace,
+    /// The sprites, mixed toward the original by this fraction.
+    Lerp(f32),
+    /// The sprites over opaque black.
+    OverBlack,
+}
+
+/// What a sprite-drawing effect draws this frame: built on the CPU (closed-form or from the
+/// simulation state), rasterised by [`SpritePlan::finish`] or the GPU compositor.
+#[derive(Clone, Debug)]
+pub struct SpritePlan {
+    pub sprites: Vec<Sprite>,
+    /// Per sprite (empty = all [`Tint::Fixed`]).
+    pub tints: Vec<Tint>,
+    pub acc: Acc,
+    pub post: Post,
+}
+
+impl SpritePlan {
+    /// Resolve layer-dependent colours against the layer `src`.
+    pub fn resolve(&mut self, src: &Image) {
+        let tints = std::mem::take(&mut self.tints);
+        self.sprites.par_iter_mut().zip(tints.par_iter()).for_each(|(sp, t)| match *t {
+            Tint::Fixed => {}
+            Tint::Refract { x, y } => {
+                let (sc, sa) = unpremul(src.sample_bilinear(x, y));
+                if sa > 0.0 {
+                    let c = sp.c;
+                    sp.c = [(sc[0] * 0.6 + 0.5) * c[0], (sc[1] * 0.6 + 0.5) * c[1], (sc[2] * 0.6 + 0.5) * c[2], c[3]];
+                }
+            }
+            Tint::Source { x, y } => {
+                let (c, a) = unpremul(src.sample_bilinear(x, y));
+                sp.c = if a <= 0.0 { [0.0; 4] } else { [c[0], c[1], c[2], a * sp.c[3]] };
+            }
+            Tint::Root { x, y, hair, inherit, shade, spec } => {
+                let root = src.sample_bilinear(x, y);
+                if root[3] < 0.5 {
+                    sp.c = [0.0; 4];
+                    return;
+                }
+                let (rc, _) = unpremul(root);
+                let base: [f32; 3] = std::array::from_fn(|k| rc[k] + (hair[k] - rc[k]) * (1.0 - inherit));
+                sp.c = [base[0] * shade + spec, base[1] * shade + spec, base[2] * shade + spec, sp.c[3]];
+            }
+        });
+    }
+
+    /// Rasterise (after [`SpritePlan::resolve`]) and meet the original layer `b`.
+    pub fn finish(&self, b: Buf) -> Buf {
+        let fx = splat(b.img.width, b.img.height, &self.sprites, self.acc);
+        self.finish_with(b, fx)
+    }
+
+    /// [`finish`](Self::finish) with a prepared sprite image (the motion-blurred average of
+    /// several frames, #1195).
+    pub fn finish_with(&self, b: Buf, fx: Image) -> Buf {
+        self.post.apply(b, fx)
+    }
+}
+
+impl Post {
+    /// Meet the sprite image `fx` with the original layer `b` (see [`SpritePlan::finish`]).
+    pub(super) fn apply(self, mut b: Buf, fx: Image) -> Buf {
+        b.img = match self {
+            Post::Combine(m) => combine(&b.img, &fx, m),
+            Post::Replace => fx,
+            Post::Lerp(t) => {
+                let mut o = fx;
+                o.data.par_iter_mut().zip(b.img.data.par_iter()).for_each(|(o, s0)| *o = crate::util::lerp4(*o, *s0, t));
+                o
+            }
+            Post::OverBlack => combine(&Image::filled(b.img.width, b.img.height, [0.0, 0.0, 0.0, 1.0]), &fx, 0),
+        };
+        b
+    }
+}
+
+fn sprite_bbox(s: &Sprite) -> Option<[f32; 4]> {
+    if s.c[3] <= 1e-5 || s.r <= 0.0 {
+        return None;
+    }
+    let r = s.r.max(0.5) + 1.0;
+    Some(match s.shape {
+        Shape::Line { dx, dy } => [s.x.min(s.x + dx) - r, s.y.min(s.y + dy) - r, s.x.max(s.x + dx) + r, s.y.max(s.y + dy) + r],
+        Shape::Star => [s.x - r * 2.0, s.y - r * 2.0, s.x + r * 2.0, s.y + r * 2.0],
+        _ => [s.x - r, s.y - r, s.x + r, s.y + r],
+    })
+}
+
+#[inline]
+pub(super) fn aa(edge: f32) -> f32 {
+    (edge + 0.5).clamp(0.0, 1.0)
+}
+
+fn sprite_shade(s: &Sprite, x: f32, y: f32) -> Option<Px> {
+    // Sub-pixel sprites keep their energy: draw at radius 0.5 with reduced opacity.
+    let (r, fade) = if s.r < 0.5 { (0.5, s.r / 0.5) } else { (s.r, 1.0) };
+    let (dx, dy) = (x - s.x, y - s.y);
+    let mut rgb = [s.c[0], s.c[1], s.c[2]];
+    let cov = match s.shape {
+        Shape::Soft => {
+            let d2 = (dx * dx + dy * dy) / (r * r);
+            if d2 >= 1.0 {
+                return None;
+            }
+            let q = 1.0 - d2;
+            q * q
+        }
+        Shape::Disc => aa(r - (dx * dx + dy * dy).sqrt()),
+        Shape::Faded => {
+            let d = (dx * dx + dy * dy).sqrt() / r;
+            (1.0 - d).max(0.0).powf(1.5)
+        }
+        Shape::Sphere => {
+            let d = (dx * dx + dy * dy).sqrt();
+            let cv = aa(r - d);
+            if cv <= 0.0 {
+                return None;
+            }
+            let (nx, ny) = (dx / r, dy / r);
+            let nz = (1.0 - nx * nx - ny * ny).max(0.0).sqrt();
+            let (lx, ly, lz) = (-0.48, -0.58, 0.66);
+            let diff = (nx * lx + ny * ly + nz * lz).max(0.0);
+            let rz = 2.0 * diff * nz - lz;
+            let spec = rz.max(0.0).powi(20) * 0.6;
+            let k = 0.2 + 0.8 * diff;
+            rgb = [rgb[0] * k + spec, rgb[1] * k + spec, rgb[2] * k + spec];
+            cv
+        }
+        Shape::Bubble => {
+            let d = (dx * dx + dy * dy).sqrt() / r;
+            if d > 1.0 + 1.0 / r {
+                return None;
+            }
+            let ring = (1.0 - ((d - 0.9) / 0.12).powi(2)).max(0.0);
+            let hl = (1.0 - (((dx / r) + 0.4).powi(2) + ((dy / r) + 0.4).powi(2)) / 0.04).max(0.0);
+            (0.12 * (d <= 1.0) as u8 as f32 + ring * 0.8 + hl).min(1.0)
+        }
+        Shape::Star => {
+            let (sn, cs) = s.rot.sin_cos();
+            let (ux, uy) = ((dx * cs + dy * sn) / r, (-dx * sn + dy * cs) / r);
+            let d = (ux * ux + uy * uy).sqrt();
+            let core = (1.0 - d).max(0.0).powi(2);
+            let sx = (1.0 - ux.abs() / 2.0).max(0.0) * (1.0 - (uy.abs() * 6.0)).max(0.0);
+            let sy = (1.0 - uy.abs() / 2.0).max(0.0) * (1.0 - (ux.abs() * 6.0)).max(0.0);
+            (core + sx + sy).min(1.0)
+        }
+        Shape::Square => {
+            let (sn, cs) = s.rot.sin_cos();
+            let (ux, uy) = (dx * cs + dy * sn, -dx * sn + dy * cs);
+            let e = r * 0.75;
+            aa(e - ux.abs()) * aa(e - uy.abs())
+        }
+        Shape::Tri => {
+            let (sn, cs) = s.rot.sin_cos();
+            let (ux, uy) = (dx * cs + dy * sn, -dx * sn + dy * cs);
+            // Equilateral triangle with circumradius r: three half-planes.
+            let e = r * 0.5;
+            let mut m = f32::INFINITY;
+            for k in 0..3 {
+                let a = std::f32::consts::FRAC_PI_2 + k as f32 * std::f32::consts::TAU / 3.0;
+                let (ns, nc) = a.sin_cos();
+                m = m.min(e - (ux * nc + uy * ns));
+            }
+            aa(m)
+        }
+        Shape::Line { dx: lx, dy: ly } => {
+            let l2 = lx * lx + ly * ly;
+            let t = if l2 > 0.0 { ((dx * lx + dy * ly) / l2).clamp(0.0, 1.0) } else { 0.0 };
+            let (px, py) = (dx - lx * t, dy - ly * t);
+            aa(r - (px * px + py * py).sqrt())
+        }
+    };
+    let a = cov * s.c[3] * fade;
+    if a <= 1e-6 {
+        return None;
+    }
+    Some([rgb[0] * a, rgb[1] * a, rgb[2] * a, a])
+}
+
+/// Draw sprites into a new transparent image of `w`×`h`.
+pub(crate) fn splat(w: u32, hgt: u32, sprites: &[Sprite], acc: Acc) -> Image {
+    let mut img = Image::new(w, hgt);
+    raster(&mut img, sprites, sprite_bbox, sprite_shade, acc);
+    img
+}
+
+/// Combine an effect layer `fx` with the original `src` (both premultiplied, same size):
+/// 0 Composite (fx over src), 1 Screen, 2 Add, 3 Lighten, 4 Darken, 5 fx only.
+pub(crate) fn combine(src: &Image, fx: &Image, mode: u32) -> Image {
+    let mut out = fx.clone();
+    out.data.par_iter_mut().zip(src.data.par_iter()).for_each(|(o, s)| {
+        let f = *o;
+        *o = match mode {
+            0 => {
+                let k = 1.0 - f[3];
+                [f[0] + s[0] * k, f[1] + s[1] * k, f[2] + s[2] * k, f[3] + s[3] * k]
+            }
+            1 => [s[0] + f[0] - s[0] * f[0], s[1] + f[1] - s[1] * f[1], s[2] + f[2] - s[2] * f[2], s[3] + f[3] - s[3] * f[3]],
+            2 => [s[0] + f[0], s[1] + f[1], s[2] + f[2], (s[3] + f[3]).min(1.0)],
+            3 => [s[0].max(f[0]), s[1].max(f[1]), s[2].max(f[2]), s[3] + f[3] - s[3] * f[3]],
+            4 => {
+                let (fc, fa) = unpremul(f);
+                let m = |c: f32, k: usize| c - (c - c.min(fc[k] * s[3])) * fa;
+                [m(s[0], 0), m(s[1], 1), m(s[2], 2), s[3]]
+            }
+            _ => f,
+        };
+    });
+    out
+}
diff --git a/crates/effects/src/sim/tests.rs b/crates/effects/src/sim/tests.rs
new file mode 100644
index 000000000..c6f83ab4e
--- /dev/null
+++ b/crates/effects/src/sim/tests.rs
@@ -0,0 +1,407 @@
+use super::*;
+use crate::{EffectEnv, run_fx};
+
+fn grey(w: u32, hh: u32) -> Image {
+    Image::filled(w, hh, [0.2, 0.2, 0.2, 1.0])
+}
+
+fn ramp(w: u32, hh: u32) -> Image {
+    let mut img = Image::new(w, hh);
+    for y in 0..hh {
+        for x in 0..w {
+            img.set(x, y, [x as f32 / w as f32, y as f32 / hh as f32, 0.4, 1.0]);
+        }
+    }
+    img
+}
+
+fn run(id: &str, vals: &[(&str, Value)], img: Image, t: f64) -> Image {
+    run_fx(id, vals, img, t, EffectEnv::default()).img
+}
+
+fn diff(a: &Image, b: &Image) -> f32 {
+    a.data.iter().zip(&b.data).map(|(p, q)| (0..4).map(|k| (p[k] - q[k]).abs()).sum::<f32>()).sum()
+}
+
+/// Centre of mass (luminance-weighted difference from `base`), `[-1, -1]` when equal.
+fn mass(img: &Image, base: &Image) -> [f32; 2] {
+    let (mut m, mut sx, mut sy) = (0.0, 0.0, 0.0);
+    for y in 0..img.height {
+        for x in 0..img.width {
+            let i = img.idx(x, y);
+            let d: f32 = (0..3).map(|k| (img.data[i][k] - base.data[i][k]).abs()).sum();
+            m += d;
+            sx += d * x as f32;
+            sy += d * y as f32;
+        }
+    }
+    if m > 0.0 { [sx / m, sy / m] } else { [-1.0; 2] }
+}
+
+/// [`mass`] in y.
+fn mass_y(img: &Image, base: &Image) -> f32 {
+    mass(img, base)[1]
+}
+
+#[test]
+fn rasteriser_over_and_add() {
+    let s = [Sprite::new(5.0, 5.0, 2.0, [1.0, 0.0, 0.0, 1.0], Shape::Disc)];
+    let img = splat(10, 40, &s, Acc::Over);
+    assert!(img.get(5, 5)[0] > 0.99 && img.get(9, 30)[3] == 0.0);
+    let two = [s[0], s[0]];
+    let add = splat(10, 40, &two, Acc::Add);
+    assert!(add.get(5, 5)[0] > 1.9);
+    // Items spanning band boundaries are drawn in every band.
+    let tall = [Sprite::new(5.0, 16.0, 6.0, [0.0, 1.0, 0.0, 1.0], Shape::Square)];
+    let t = splat(10, 40, &tall, Acc::Over);
+    assert!(t.get(5, 13)[1] > 0.9 && t.get(5, 18)[1] > 0.9);
+}
+
+#[test]
+fn rainfall_deterministic_and_falls() {
+    let vals = [("drops", num(200.0)), ("opacity", num(100.0)), ("extras/appearance", Value::Enum(1)), ("color", col(1.0, 1.0, 1.0))];
+    let a = run("ec.sim.ccrainfall", &vals, grey(40, 40), 0.5);
+    let b = run("ec.sim.ccrainfall", &vals, grey(40, 40), 0.5);
+    assert_eq!(a, b);
+    assert!(diff(&a, &grey(40, 40)) > 1.0, "drops visible");
+    let none = run("ec.sim.ccrainfall", &[("drops", num(0.0))], grey(40, 40), 0.5);
+    assert_eq!(none, grey(40, 40));
+    let later = run("ec.sim.ccrainfall", &vals, grey(40, 40), 0.52);
+    assert!(diff(&a, &later) > 0.1, "rain moves");
+}
+
+#[test]
+fn snowfall_deterministic_and_moves() {
+    let vals = [("flakes", num(300.0))];
+    let a = run("ec.sim.ccsnowfall", &vals, grey(40, 40), 1.0);
+    assert_eq!(a, run("ec.sim.ccsnowfall", &vals, grey(40, 40), 1.0));
+    assert!(diff(&a, &grey(40, 40)) > 1.0);
+    assert!(diff(&a, &run("ec.sim.ccsnowfall", &vals, grey(40, 40), 1.2)) > 0.1);
+    let off = run("ec.sim.ccsnowfall", &[("flakes", num(300.0)), ("compositeWithOriginal", Value::Bool(false))], grey(40, 40), 1.0);
+    assert!(off.data.iter().any(|p| p[3] == 0.0), "without original the background is transparent");
+}
+
+#[test]
+fn bubbles_rise() {
+    let vals = [("bubbleAmount", num(30.0)), ("bubbleSize", num(3.0))];
+    let a = run("ec.sim.ccbubbles", &vals, ramp(40, 40), 0.3);
+    assert_eq!(a, run("ec.sim.ccbubbles", &vals, ramp(40, 40), 0.3));
+    assert!(a.data.iter().any(|p| p[3] > 0.5));
+    let none = run("ec.sim.ccbubbles", &[("bubbleAmount", num(0.0))], ramp(40, 40), 0.3);
+    assert!(none.data.iter().all(|p| p[3] == 0.0), "bubbles replace the layer");
+    // A single slow bubble moves up over a short time.
+    let one = [("bubbleAmount", num(1.0)), ("bubbleSize", num(4.0)), ("wobbleAmplitude", num(0.0)), ("bubbleSpeed", num(0.2))];
+    let blank = Image::new(40, 40);
+    let y0 = mass_y(&run("ec.sim.ccbubbles", &one, ramp(40, 40), 0.0), &blank);
+    let y1 = mass_y(&run("ec.sim.ccbubbles", &one, ramp(40, 40), 0.1), &blank);
+    assert!(y0 >= 0.0 && y1 >= 0.0 && (y1 < y0 || y0 < 8.0), "{y0} -> {y1}");
+}
+
+#[test]
+fn drizzle_ripples() {
+    let a = run("ec.sim.ccdrizzle", &[], ramp(48, 48), 0.6);
+    assert_eq!(a, run("ec.sim.ccdrizzle", &[], ramp(48, 48), 0.6));
+    assert!(diff(&a, &ramp(48, 48)) > 0.1);
+    let none = run("ec.sim.ccdrizzle", &[("dripRate", num(0.0))], ramp(48, 48), 0.6);
+    assert_eq!(none, ramp(48, 48));
+}
+
+#[test]
+fn star_burst_moves_stars() {
+    let a = run("ec.sim.ccstarburst", &[("gridSpacing", num(4.0))], ramp(40, 40), 0.5);
+    assert_eq!(a, run("ec.sim.ccstarburst", &[("gridSpacing", num(4.0))], ramp(40, 40), 0.5));
+    assert!(a.data.iter().any(|p| p[3] > 0.0));
+    let b = run("ec.sim.ccstarburst", &[("gridSpacing", num(4.0))], ramp(40, 40), 0.9);
+    assert!(diff(&a, &b) > 0.5);
+    let full = run("ec.sim.ccstarburst", &[("blendWithOriginal", num(100.0))], ramp(40, 40), 0.5);
+    assert!(diff(&full, &ramp(40, 40)) < 1e-3);
+}
+
+fn pw_vals(seed: f64) -> Vec<(&'static str, Value)> {
+    vec![
+        ("birthRate", num(1.0)),
+        ("extras/randomSeed", num(seed)),
+        ("particle/particleType", Value::Enum(2)),
+        ("particle/birthSize", num(0.3)),
+        ("particle/deathSize", num(0.3)),
+    ]
+}
+
+/// #1195: with the comp's shutter open, the particles smear across it: the average of the
+/// sampled sprite fields differs from the sharp frame, touches more pixels and keeps the
+/// alpha energy.
+#[test]
+fn particle_world_motion_blur_trails() {
+    let v = pw_vals(21.0);
+    let blank = Image::new(40, 40);
+    let sharp = run("ec.sim.ccparticleworld", &v, blank.clone(), 2.0);
+    let blurred = crate::run_fx(
+        "ec.sim.ccparticleworld",
+        &v,
+        blank.clone(),
+        2.0,
+        EffectEnv { frame_rate: 10.0, shutter: Some((360.0, -180.0, 8)), ..Default::default() },
+    )
+    .img;
+    assert!(sharp.data.iter().any(|p| p[3] > 0.0), "sharp frame has particles");
+    assert_ne!(sharp.data, blurred.data, "the shutter smears the particles");
+    let lit = |img: &Image| img.data.iter().filter(|p| p[3] > 0.005).count();
+    let sum = |img: &Image| img.data.iter().map(|p| p[3]).sum::<f32>();
+    assert!(lit(&blurred) > lit(&sharp), "trails light more pixels: {} vs {}", lit(&blurred), lit(&sharp));
+    let (sa, ba) = (sum(&sharp), sum(&blurred));
+    assert!((ba - sa).abs() < sa * 0.6 + 1.0, "alpha energy roughly kept: {ba} vs {sa}");
+}
+
+#[test]
+fn particle_world_seek_consistent() {
+    let v = pw_vals(11.0);
+    let direct = run("ec.sim.ccparticleworld", &v, Image::new(40, 40), 2.0);
+    let v2 = pw_vals(12.0);
+    let _ = run("ec.sim.ccparticleworld", &v2, Image::new(40, 40), 1.0);
+    let stepped = run("ec.sim.ccparticleworld", &v2, Image::new(40, 40), 2.0);
+    let direct2 = run("ec.sim.ccparticleworld", &v2, Image::new(40, 40), 2.0);
+    assert_eq!(stepped, direct2);
+    assert!(direct.data.iter().any(|p| p[3] > 0.0), "particles alive");
+    // Before birth nothing is drawn.
+    let t0 = run("ec.sim.ccparticleworld", &v, Image::new(40, 40), 0.0);
+    assert!(t0.data.iter().all(|p| p[3] == 0.0));
+}
+
+#[test]
+fn engine_resume_equals_from_scratch() {
+    for anim in 0..PW_ANIMS.len() as u32 {
+        let phys = Phys {
+            rate: 90.0,
+            life: 1.5,
+            producer: [0.0; 3],
+            radius: [0.05; 3],
+            anim,
+            speed: 0.5,
+            gravity: [0.0, 0.5, 0.0],
+            resistance: 0.2,
+            axis: [0.0, -1.0, 0.0],
+            extra: 1.0,
+            extra_angle: 60.0,
+            seed: 9,
+            max: 10_000,
+            flat: anim % 2 == 0,
+        };
+        let a: SimCache<PState> = SimCache::new(2);
+        let b: SimCache<PState> = SimCache::new(2);
+        let direct = simulate(&a, 1, 2.0, &phys);
+        let _ = simulate(&b, 1, 1.0, &phys);
+        let _ = simulate(&b, 1, 0.37, &phys);
+        let resumed = simulate(&b, 1, 2.0, &phys);
+        assert_eq!(direct.parts.len(), resumed.parts.len(), "anim {anim}");
+        assert!(direct.parts.iter().zip(&resumed.parts).all(|(p, q)| p.p == q.p && p.v == q.v && p.id == q.id), "anim {anim}");
+        assert!(!direct.parts.is_empty());
+    }
+}
+
+#[test]
+fn particle_world_gravity_pulls_down() {
+    let base = |g: f64| {
+        vec![
+            ("birthRate", num(2.0)),
+            ("physics/velocity", num(0.2)),
+            ("physics/gravity", num(g)),
+            ("particle/particleType", Value::Enum(2)),
+            ("particle/birthSize", num(0.2)),
+            ("particle/deathSize", num(0.2)),
+            ("longevity", num(3.0)),
+        ]
+    };
+    let blank = Image::new(48, 48);
+    let up = mass_y(&run("ec.sim.ccparticleworld", &base(0.0), blank.clone(), 1.0), &blank);
+    let down = mass_y(&run("ec.sim.ccparticleworld", &base(2.0), blank.clone(), 1.0), &blank);
+    assert!(down > up + 2.0, "{up} {down}");
+}
+
+/// A comp whose camera is `camera` ([`crate::CompScene::camera`]); `layer`: a camera layer
+/// (else the comp's default view).
+struct Comp {
+    camera: [[f64; 4]; 3],
+    layer: bool,
+}
+impl crate::EffectHost for Comp {
+    fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
+        None
+    }
+    fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+        None
+    }
+    fn comp_scene(&self) -> Option<crate::CompScene> {
+        Some(crate::CompScene { camera: Some(self.camera), camera_layer: self.layer, light: None })
+    }
+}
+
+/// A camera `d` px in front of layer point `c` looking at it, moved right by `dx` px and
+/// zoomed by `zoom` (1 = identity on the layer plane): `c + zoom·d·(p − c − dx) / (z + d)`.
+fn cam(c: [f64; 2], d: f64, dx: f64, zoom: f64) -> [[f64; 4]; 3] {
+    let k = zoom * d;
+    [[k, 0.0, c[0], d * c[0] - k * (c[0] + dx)], [0.0, k, c[1], d * c[1] - k * c[1]], [0.0, 0.0, 1.0, d]]
+}
+
+fn pw_in(comp: &Comp, vals: &[(&str, Value)]) -> Image {
+    run_fx("ec.sim.ccparticleworld", vals, Image::new(48, 48), 1.0, EffectEnv { host: Some(comp), ..Default::default() }).img
+}
+
+fn finite(img: &Image) -> bool {
+    img.data.iter().all(|p| p.iter().all(|c| c.is_finite()))
+}
+
+/// #397: with a camera layer in the comp, the particles are seen through it.
+#[test]
+fn particle_world_follows_the_comp_camera() {
+    let v = pw_vals(3.0);
+    let blank = Image::new(48, 48);
+    let here = Comp { camera: cam([24.0, 24.0], 96.0, 0.0, 1.0), layer: true };
+    let base = pw_in(&here, &v);
+    assert!(base.data.iter().any(|p| p[3] > 0.0), "particles alive");
+    // Moving the camera right moves the particles left.
+    let moved = pw_in(&Comp { camera: cam([24.0, 24.0], 96.0, 8.0, 1.0), ..here }, &v);
+    let (a, b) = (mass(&base, &blank), mass(&moved, &blank));
+    assert!(b[0] < a[0] - 4.0 && (b[1] - a[1]).abs() < 2.0, "{a:?} -> {b:?}");
+    // Zooming in spreads them out.
+    let zoomed = pw_in(&Comp { camera: cam([24.0, 24.0], 96.0, 0.0, 2.0), ..here }, &v);
+    let cover = |i: &Image| i.data.iter().filter(|p| p[3] > 0.01).count();
+    assert!(cover(&zoomed) > cover(&base), "{} {}", cover(&zoomed), cover(&base));
+    // The Effect Camera is ignored then.
+    let mut turned = v.clone();
+    turned.push(("extras/effectCamera/rotationY", num(60.0)));
+    assert_eq!(pw_in(&here, &turned), base);
+    // The comp's default view (no camera layer) leaves it to the Effect Camera.
+    let default_view = Comp { layer: false, ..here };
+    assert_eq!(pw_in(&default_view, &v), run("ec.sim.ccparticleworld", &v, blank.clone(), 1.0));
+    // A camera facing away, or a degenerate one, draws nothing and never NaN.
+    for camera in [[[96.0, 0.0, 24.0, 0.0], [0.0, 96.0, 24.0, 0.0], [0.0, 0.0, -1.0, -96.0]], [[0.0; 4]; 3], [[f64::NAN; 4]; 3]] {
+        assert_eq!(pw_in(&Comp { camera, layer: true }, &v), blank);
+    }
+    // A camera among the particles draws the ones in front of it.
+    let inside = pw_in(&Comp { camera: cam([24.0, 24.0], 1.0, 0.0, 1.0), ..here }, &v);
+    assert!(finite(&inside));
+}
+
+/// Extras ▸ Effect Camera: the defaults are the fixed camera Particle World always had.
+#[test]
+fn particle_world_effect_camera() {
+    let v = pw_vals(5.0);
+    let base = run("ec.sim.ccparticleworld", &v, Image::new(48, 48), 1.0);
+    let with = |extra: &[(&'static str, Value)]| {
+        let mut w = v.clone();
+        w.extend_from_slice(extra);
+        run("ec.sim.ccparticleworld", &w, Image::new(48, 48), 1.0)
+    };
+    // Missing parameters (projects saved before) read as the defaults.
+    let spec = crate::find("ec.sim.ccparticleworld").unwrap();
+    let mut params = crate::Params { values: spec.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+    params.values.retain(|k, _| !k.starts_with(PW_EFFECT_CAMERA));
+    for (k, val) in &v {
+        params.values.insert(k.to_string(), val.clone());
+    }
+    let ctx = EffectCtx { params: &params, time: 1.0, layer_size: [48.0, 48.0], seed: 1, adjustment: false, env: EffectEnv::default() };
+    assert_eq!(crate::apply(spec, &ctx, Buf { img: Image::new(48, 48), offset: [0.0; 2], scale: 1.0 }).img, base);
+    assert_eq!(with(&[("extras/effectCamera/fov", num(f64::NAN))]), base);
+    // Turning or pulling back the camera changes the view.
+    let turned = with(&[("extras/effectCamera/rotationY", num(60.0))]);
+    assert!(diff(&turned, &base) > 1.0);
+    let cover = |i: &Image| i.data.iter().filter(|p| p[3] > 0.01).count();
+    let far = with(&[("extras/effectCamera/distance", num(4.0))]);
+    assert!(cover(&far) < cover(&base), "{} {}", cover(&far), cover(&base));
+    assert!(diff(&with(&[("extras/effectCamera/fov", num(120.0))]), &base) > 0.1);
+    // Extremes never panic or produce NaN.
+    for extra in [
+        ("extras/effectCamera/distance", num(0.0)),
+        ("extras/effectCamera/distance", num(-5.0)),
+        ("extras/effectCamera/fov", num(0.0)),
+        ("extras/effectCamera/fov", num(180.0)),
+        ("extras/effectCamera/rotationX", num(1e12)),
+    ] {
+        assert!(finite(&with(std::slice::from_ref(&extra))), "{extra:?}");
+    }
+    // Moving the camera doesn't restart the simulation.
+    let key =
+        |pr: &crate::Params| sim_key(&EffectCtx { params: pr, time: 1.0, layer_size: [48.0, 48.0], seed: 1, adjustment: false, env: EffectEnv::default() }, 1);
+    let mut moved = params.clone();
+    moved.values.insert("extras/effectCamera/rotationZ".into(), num(30.0));
+    assert_eq!(key(&params), key(&moved));
+    moved.values.insert("extras/randomSeed".into(), num(9.0));
+    assert_ne!(key(&params), key(&moved));
+}
+
+#[test]
+fn particle_systems2_seek_and_direction() {
+    let v = vec![
+        ("producer/position", pt(24.0, 24.0)),
+        ("birthRate", num(3.0)),
+        ("physics/gravity", num(0.0)),
+        ("physics/velocity", num(1.0)),
+        ("physics/animation", Value::Enum(1)),
+    ];
+    let _ = run("ec.sim.ccparticlesystems2", &v, Image::new(48, 48), 0.5);
+    let a = run("ec.sim.ccparticlesystems2", &v, Image::new(48, 48), 1.0);
+    let mut v2 = v.clone();
+    v2.push(("randomSeed", num(0.0)));
+    assert_eq!(a, run("ec.sim.ccparticlesystems2", &v2, Image::new(48, 48), 1.0));
+    // Direction 0° (up): particles above the producer.
+    let blank = Image::new(48, 48);
+    let y = mass_y(&a, &blank);
+    assert!((0.0..24.0).contains(&y), "{y}");
+    // The particles replace the layer: with none born it is empty.
+    let none = run("ec.sim.ccparticlesystems2", &[("birthRate", num(0.0))], grey(20, 20), 1.0);
+    assert_eq!(none, Image::new(20, 20));
+}
+
+/// CC Particle World and CC Particle Systems II replace their layer with the particles, in
+/// every Transfer Mode (which only sets how particles meet each other). SceneYard frames from
+/// After Effects 2026 show no trace of the source solid: "Task Preparation UI" (black solids
+/// under fireworks hid a white page), "Burnout matchstick" (a red rectangle around the
+/// flame), "Documentary Man Falling" (a black block over the light).
+#[test]
+fn cc_particles_replace_their_layer() {
+    let red = || {
+        let mut img = Image::new(48, 48);
+        img.data.iter_mut().for_each(|p| *p = [0.7, 0.1, 0.1, 1.0]);
+        img
+    };
+    for id in ["ec.sim.ccparticlesystems2", "ec.sim.ccparticleworld"] {
+        for mode in 0..4 {
+            let v = vec![("birthRate", num(3.0)), ("particle/transferMode", Value::Enum(mode))];
+            let _ = run(id, &v, red(), 0.5);
+            let out = run(id, &v, red(), 1.0);
+            // No source left: the corners, far from the producer, are clear.
+            for (x, y) in [(0, 0), (47, 0), (0, 47), (47, 47)] {
+                assert!(out.get(x, y)[3] < 1e-6, "{id} mode {mode} ({x},{y}): {:?}", out.get(x, y));
+            }
+            assert!(out.data.iter().any(|p| p[3] > 0.05), "{id} mode {mode}: particles drawn");
+        }
+    }
+}
+
+#[test]
+fn mercury_blobs_and_seek() {
+    let v = vec![("producer", pt(24.0, 16.0)), ("radiusX", num(5.0)), ("radiusY", num(5.0)), ("birthRate", num(3.0))];
+    let _ = run("ec.sim.ccmrmercury", &v, ramp(48, 48), 0.7);
+    let a = run("ec.sim.ccmrmercury", &v, ramp(48, 48), 1.4);
+    let mut v2 = v.clone();
+    v2.push(("shading/metal", num(100.0)));
+    let b = run("ec.sim.ccmrmercury", &v2, ramp(48, 48), 1.4);
+    assert_eq!(a, b);
+    assert!(a.data.iter().any(|p| p[3] > 0.5), "blobs visible");
+    let none = run("ec.sim.ccmrmercury", &[("birthRate", num(0.0))], ramp(48, 48), 1.4);
+    assert!(none.data.iter().all(|p| p[3] == 0.0));
+}
+
+#[test]
+fn half_resolution_scales_sprites() {
+    // Downsampled buffers render the same layout at half size.
+    let s = crate::find("ec.sim.ccsnowfall").unwrap();
+    let mut params = crate::Params { values: s.params.iter().map(|p| (p.id.to_string(), p.default.clone())).collect() };
+    params.values.insert("flakes".into(), num(50.0));
+    params.values.insert("offset".into(), pt(20.0, 20.0));
+    let ctx = EffectCtx { params: &params, time: 0.5, layer_size: [40.0, 40.0], seed: 1, adjustment: false, env: EffectEnv::default() };
+    let full = crate::apply(s, &ctx, Buf { img: grey(40, 40), offset: [0.0; 2], scale: 1.0 });
+    let half = crate::apply(s, &ctx, Buf { img: grey(20, 20), offset: [0.0; 2], scale: 0.5 });
+    let sum = |i: &Image| i.data.iter().map(|p| p[0]).sum::<f32>() / i.data.len() as f32;
+    assert!((sum(&full.img) - sum(&half.img)).abs() < 0.05, "{} {}", sum(&full.img), sum(&half.img));
+}
diff --git a/crates/effects/src/sim/weather.rs b/crates/effects/src/sim/weather.rs
new file mode 100644
index 000000000..b93c0e48b
--- /dev/null
+++ b/crates/effects/src/sim/weather.rs
@@ -0,0 +1,352 @@
+use super::common::{h, hs};
+use super::sprites::{Acc, Post, Shape, Sprite, SpritePlan, Tint, aa, raster};
+use super::{Buf, EffectCtx, Image, IntoParallelIterator, ParallelIterator, unpremul};
+
+// ------------------------------------------------------------------ CC Rainfall / CC Snowfall
+
+/// Shared weather layout: per-item depth factor `k` in (0, 1] (1 = nearest) from Scene Depth.
+#[inline]
+fn depth_k(z: f32, scene_depth: f32) -> f32 {
+    1.0 / (1.0 + z * scene_depth / 2500.0)
+}
+
+/// Wrap `v` into `[lo, lo + span)`.
+#[inline]
+fn wrap(v: f32, lo: f32, span: f32) -> f32 {
+    if span <= 0.0 { v } else { lo + (v - lo).rem_euclid(span) }
+}
+
+pub(super) fn rainfall(ctx: &EffectCtx, b: Buf) -> Buf {
+    let mut plan = rainfall_plan(ctx, &b);
+    plan.resolve(&b.img);
+    plan.finish(b)
+}
+
+pub(super) fn rainfall_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
+    let pr = ctx.params;
+    let n = pr.f("drops").clamp(0.0, 100_000.0) as u32;
+    let size = pr.f("size").max(0.0) as f32;
+    let depth = pr.f("sceneDepth").max(0.0) as f32;
+    let speed = pr.f("speed") as f32;
+    let wind = pr.f("wind") as f32;
+    let wvar = pr.f("windVariation") as f32 / 100.0;
+    let spread = pr.f("spread") as f32;
+    let color = pr.color("color");
+    let opacity = pr.f("opacity") as f32 / 100.0;
+    let mode = pr.e("transferMode");
+    let with_orig = pr.b("compositeWithOriginal");
+    let refract = pr.e("extras/appearance") == 0;
+    let off = pr.v2("extras/offset");
+    let seed = pr.f("extras/randomSeed") as u32 ^ ctx.seed.wrapping_mul(0x9e37);
+    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
+    let s = b.scale as f32;
+    let t = ctx.time as f32;
+    let (ox, oy) = (off[0] as f32 - lw * 0.5, off[1] as f32 - lh * 0.5);
+    let (sprites, tints): (Vec<Sprite>, Vec<Tint>) = (0..n)
+        .into_par_iter()
+        .map(|i| {
+            let z = h(i, 1, seed);
+            let k = depth_k(z, depth);
+            let vy = speed / 4000.0 * lh * 2.2 * k;
+            let w = wind / 1000.0 * lh * (1.0 + wvar * hs(i, 2, seed)) * k + spread * hs(i, 7, seed) * k;
+            let len = (vy * 0.04 * size.max(0.2)).max(1.0);
+            let lenx = w * 0.04 * size.max(0.2);
+            let margin = len + lenx.abs() + 4.0;
+            let y = wrap(h(i, 3, seed) * (lh + 2.0 * margin) + vy * t + oy, -margin, lh + 2.0 * margin);
+            let x = wrap(h(i, 4, seed) * (lw + 2.0 * margin) + w * t + ox, -margin, lw + 2.0 * margin);
+            let (bx, by) = b.to_px([x as f64, y as f64]);
+            let c = [color[0], color[1], color[2], opacity * (0.35 + 0.65 * k)];
+            // Refracting drops show the scene behind them, brightened and offset.
+            let tint = if refract { Tint::Refract { x: bx + 2.0 * s as f64, y: by } } else { Tint::Fixed };
+            let r = (size * 0.6 * k * s).max(0.25);
+            (Sprite::new(bx as f32, by as f32, r, c, Shape::Line { dx: -lenx * s, dy: -len * s }), tint)
+        })
+        .unzip();
+    SpritePlan { sprites, tints, acc: Acc::Over, post: weather_post(mode, with_orig) }
+}
+
+fn weather_post(mode: u32, with_orig: bool) -> Post {
+    if with_orig { Post::Combine(if mode == 1 { 3 } else { 0 }) } else { Post::Replace }
+}
+
+pub(super) fn snowfall(ctx: &EffectCtx, b: Buf) -> Buf {
+    snowfall_plan(ctx, &b).finish(b)
+}
+
+pub(super) fn snowfall_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
+    let pr = ctx.params;
+    let n = pr.f("flakes").clamp(0.0, 200_000.0) as u32;
+    let size = pr.f("size").max(0.0) as f32;
+    let svar = pr.f("sizeVariation") as f32 / 100.0;
+    let depth = pr.f("sceneDepth").max(0.0) as f32;
+    let speed = pr.f("speed") as f32;
+    let spvar = pr.f("speedVariation") as f32 / 100.0;
+    let wind = pr.f("wind") as f32;
+    let wvar = pr.f("windVariation") as f32 / 100.0;
+    let spread = pr.f("spread") as f32;
+    let wig = pr.f("wiggle/wiggleAmount") as f32;
+    let wigvar = pr.f("wiggle/wiggleAmountVariation") as f32 / 100.0;
+    let wfreq = pr.f("wiggle/wiggleFrequency") as f32;
+    let wfvar = pr.f("wiggle/wiggleFrequencyVariation") as f32 / 100.0;
+    let color = pr.color("color");
+    let opacity = pr.f("opacity") as f32 / 100.0;
+    let mode = pr.e("transferMode");
+    let with_orig = pr.b("compositeWithOriginal");
+    let off = pr.v2("extras/offset");
+    let seed = pr.f("extras/randomSeed") as u32 ^ ctx.seed.wrapping_mul(0x85eb);
+    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
+    let s = b.scale as f32;
+    let t = ctx.time as f32;
+    let (ox, oy) = (off[0] as f32 - lw * 0.5, off[1] as f32 - lh * 0.5);
+    let sprites: Vec<Sprite> = (0..n)
+        .into_par_iter()
+        .map(|i| {
+            let z = h(i, 1, seed);
+            let k = depth_k(z, depth);
+            let r = (size * 0.5 * k * (1.0 + svar * hs(i, 2, seed))).max(0.05);
+            let vy = speed * (lh / 600.0) * k * (1.0 + spvar * hs(i, 3, seed));
+            let vx = wind * (lh / 1200.0) * k * (1.0 + wvar * hs(i, 4, seed)) + spread * hs(i, 8, seed) * k;
+            let amp = wig * 2.0 * k * (1.0 + wigvar * hs(i, 5, seed));
+            let fr = wfreq * (1.0 + wfvar * hs(i, 6, seed));
+            let ph = h(i, 9, seed) * std::f32::consts::TAU;
+            let margin = r + amp.abs() + 2.0;
+            let y = wrap(h(i, 10, seed) * (lh + 2.0 * margin) + vy * t + oy, -margin, lh + 2.0 * margin);
+            let x = wrap(h(i, 11, seed) * (lw + 2.0 * margin) + vx * t + ox, -margin, lw + 2.0 * margin) + amp * (fr * t * std::f32::consts::TAU + ph).sin();
+            let (bx, by) = b.to_px([x as f64, y as f64]);
+            Sprite::new(bx as f32, by as f32, r * s, [color[0], color[1], color[2], opacity * (0.4 + 0.6 * k)], Shape::Soft)
+        })
+        .collect();
+    SpritePlan { sprites, tints: vec![], acc: Acc::Over, post: weather_post(mode, with_orig) }
+}
+
+// ------------------------------------------------------------------ CC Bubbles
+
+/// A CC Bubbles bubble in buffer pixels.
+#[derive(Clone, Copy, Debug)]
+pub struct Bubble {
+    pub x: f32,
+    pub y: f32,
+    pub r: f32,
+    /// Source sample centre (buffer px).
+    pub sx: f32,
+    pub sy: f32,
+}
+
+/// CC Bubbles' bubbles this frame (closed-form in time) for buffer geometry `b`.
+pub fn bubble_list(ctx: &EffectCtx, b: &Buf) -> Vec<Bubble> {
+    let pr = ctx.params;
+    let n = pr.f("bubbleAmount").clamp(0.0, 10_000.0) as u32;
+    let speed = pr.f("bubbleSpeed") as f32;
+    let wamp = pr.f("wobbleAmplitude") as f32;
+    let wfreq = pr.f("wobbleFrequency") as f32;
+    let bsize = pr.f("bubbleSize").max(0.0) as f32;
+    let seed = ctx.seed.wrapping_mul(0x27d4);
+    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
+    let s = b.scale as f32;
+    let t = ctx.time as f32;
+    let base = lw.min(lh) * 0.035 * bsize;
+    (0..n)
+        .map(|i| {
+            let r = base * (0.5 + h(i, 1, seed));
+            let travel = lh + 2.0 * r;
+            let v = speed * lh * 0.3 * (0.6 + 0.8 * h(i, 2, seed));
+            let y = lh + r - (h(i, 3, seed) * travel + v * t).rem_euclid(travel);
+            let x0 = h(i, 4, seed) * lw;
+            let x = x0 + wamp * (r / base.max(1e-3)) * (t * wfreq * std::f32::consts::TAU + h(i, 5, seed) * std::f32::consts::TAU).sin();
+            let (bx, by) = b.to_px([x as f64, y as f64]);
+            let (sx, sy) = b.to_px([x0 as f64, y as f64]);
+            Bubble { x: bx as f32, y: by as f32, r: r * s, sx: sx as f32, sy: sy as f32 }
+        })
+        .collect()
+}
+
+pub(super) fn bubbles(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let pr = ctx.params;
+    let metal = pr.e("reflectionType") == 1;
+    let shading = pr.e("shadingType");
+    let list = bubble_list(ctx, &b);
+    let src = b.img.clone();
+    let mut out = Image::new(src.width, src.height);
+    raster(
+        &mut out,
+        &list,
+        |q| Some([q.x - q.r - 1.0, q.y - q.r - 1.0, q.x + q.r + 1.0, q.y + q.r + 1.0]),
+        |q, x, y| {
+            let (dx, dy) = ((x - q.x) / q.r.max(0.5), (y - q.y) / q.r.max(0.5));
+            let d2 = dx * dx + dy * dy;
+            let d = d2.sqrt();
+            let cov = aa((1.0 - d) * q.r);
+            if cov <= 0.0 {
+                return None;
+            }
+            // Liquid refracts (inverted, magnified), metal reflects (wide-angle mirror).
+            let k = if metal { 1.6 } else { -0.7 };
+            let nz = (1.0 - d2).max(0.0).sqrt();
+            let p = src.sample_bilinear((q.sx + dx * q.r * k) as f64, (q.sy + dy * q.r * k) as f64);
+            let (c, sa) = unpremul(p);
+            let mut c = if sa <= 0.0 { [0.6, 0.7, 0.8] } else { c };
+            let mut a = cov;
+            match shading {
+                1 => c = c.map(|v| v * 0.7 + 0.3 * (1.0 - nz)),
+                2 => c = c.map(|v| v * (0.5 + 0.5 * nz)),
+                3 => a *= nz.powf(0.5),
+                4 => a *= 1.0 - nz * 0.8,
+                _ => {}
+            }
+            let hl = (1.0 - ((dx + 0.35).powi(2) + (dy + 0.35).powi(2)) / 0.05).max(0.0) * 0.8;
+            let c = c.map(|v| v + hl);
+            Some([c[0] * a, c[1] * a, c[2] * a, a])
+        },
+        Acc::Over,
+    );
+    b.img = out;
+    b
+}
+
+// ------------------------------------------------------------------ CC Drizzle
+
+/// CC Drizzle's live drops this frame (buffer px: centre x, y, ring radius, amplitude);
+/// `None` = no drops yet (the layer passes through).
+pub fn drizzle_drops(ctx: &EffectCtx, b: &Buf) -> Option<Vec<[f32; 4]>> {
+    let pr = ctx.params;
+    let rate = pr.f("dripRate").max(0.0);
+    let life = pr.f("longevity").max(0.01);
+    let spreading = pr.f("spreading") as f32;
+    let height = pr.f("rippleHeight") as f32 / 100.0;
+    let seed = ctx.seed.wrapping_mul(0x165667b1);
+    let t = ctx.time;
+    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
+    let s = b.scale as f32;
+    if rate <= 0.0 || t < 0.0 {
+        return None;
+    }
+    // Drops born at k / rate with hashed positions; alive while younger than the longevity.
+    let k0 = ((t - life) * rate).floor().max(0.0) as u32;
+    let k1 = (t * rate).floor() as u32;
+    let mut drops = Vec::new();
+    for k in k0..=k1 {
+        let born = k as f64 / rate;
+        let age = (t - born) as f32;
+        if age < 0.0 || age as f64 >= life {
+            continue;
+        }
+        let (x, y) = b.to_px([(h(k, 1, seed) * lw) as f64, (h(k, 2, seed) * lh) as f64]);
+        let radius = spreading * age * lh / 400.0 * s;
+        let amp = height * (1.0 - age / life as f32) * (0.6 + 0.4 * h(k, 3, seed));
+        drops.push([x as f32, y as f32, radius, amp]);
+    }
+    Some(drops)
+}
+
+pub(super) fn drizzle(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let pr = ctx.params;
+    let Some(drops) = drizzle_drops(ctx, &b) else { return b };
+    let rippling = (pr.f("rippling") / 360.0).max(0.05) as f32;
+    let disp = pr.f("displacement") as f32;
+    let li = pr.f("light/lightIntensity") as f32 / 100.0;
+    let lc = pr.color("light/lightColor");
+    let lheight = pr.f("light/lightHeight") as f32 / 100.0;
+    let ldir = (pr.f("light/lightDirection") as f32).to_radians();
+    let ambient = pr.f("shading/ambient") as f32 / 100.0;
+    let diffuse = pr.f("shading/diffuse") as f32 / 100.0;
+    let specular = pr.f("shading/specular") as f32 / 100.0;
+    let rough = pr.f("shading/roughness").max(0.001) as f32;
+    let lh = ctx.layer_size[1] as f32;
+    let s = b.scale as f32;
+    let wavelen = (lh * 0.04 * s).max(2.0) / rippling.clamp(0.25, 4.0);
+    let width = wavelen * (1.0 + rippling * 2.0);
+    let field = |x: f32, y: f32| -> f32 {
+        let mut v = 0.0;
+        for &[dx, dy, r, a] in &drops {
+            let d = ((x - dx).powi(2) + (y - dy).powi(2)).sqrt();
+            let u = (d - r) / width;
+            if u.abs() < 1.0 {
+                let env = 0.5 + 0.5 * (u * std::f32::consts::PI).cos();
+                v += a * env * ((d - r) / wavelen * std::f32::consts::TAU).cos();
+            }
+        }
+        v
+    };
+    let src = b.img.clone();
+    let (ls, lcs) = ldir.sin_cos();
+    let l = {
+        let v = [lcs, ls, lheight.max(0.05)];
+        let n = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt();
+        [v[0] / n, v[1] / n, v[2] / n]
+    };
+    b.img.rows_mut().for_each(|(y, row)| {
+        for (x, px) in row.iter_mut().enumerate() {
+            let (fx, fy) = (x as f32 + 0.5, y as f32 + 0.5);
+            let gx = field(fx + 1.0, fy) - field(fx - 1.0, fy);
+            let gy = field(fx, fy + 1.0) - field(fx, fy - 1.0);
+            if gx == 0.0 && gy == 0.0 {
+                continue;
+            }
+            let p = src.sample_bilinear_clamped((fx - gx * disp * s * 4.0) as f64, (fy - gy * disp * s * 4.0) as f64);
+            let n = {
+                let v = [-gx * 6.0, -gy * 6.0, 1.0];
+                let m = (v[0] * v[0] + v[1] * v[1] + 1.0).sqrt();
+                [v[0] / m, v[1] / m, v[2] / m]
+            };
+            let nl = (n[0] * l[0] + n[1] * l[1] + n[2] * l[2]).max(0.0);
+            let hz = (l[2] + 1.0) * 0.5;
+            let hv = {
+                let v = [l[0] * 0.5, l[1] * 0.5, hz];
+                let m = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt();
+                [v[0] / m, v[1] / m, v[2] / m]
+            };
+            let sp = (n[0] * hv[0] + n[1] * hv[1] + n[2] * hv[2]).max(0.0).powf(1.0 / rough) * specular * li;
+            let shade = 1.0 + (ambient + diffuse * nl - diffuse * l[2]) * li;
+            let a = p[3];
+            *px = [p[0] * shade + sp * lc[0] * a, p[1] * shade + sp * lc[1] * a, p[2] * shade + sp * lc[2] * a, a];
+        }
+    });
+    b
+}
+
+// ------------------------------------------------------------------ CC Star Burst
+
+pub(super) fn star_burst(ctx: &EffectCtx, b: Buf) -> Buf {
+    let mut plan = star_burst_plan(ctx, &b);
+    plan.resolve(&b.img);
+    plan.finish(b)
+}
+
+pub(super) fn star_burst_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
+    let pr = ctx.params;
+    let scatter = pr.f("scatter") as f32;
+    let speed = pr.f("speed") as f32;
+    let phase = pr.f("phase") as f32 / 360.0;
+    let spacing = pr.f("gridSpacing").max(1.0) as f32;
+    let size = pr.f("size") as f32 / 100.0;
+    let blend = pr.f("blendWithOriginal") as f32 / 100.0;
+    let seed = ctx.seed.wrapping_mul(0x3c6e);
+    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
+    let s = b.scale as f32;
+    let t = ctx.time as f32;
+    let nx = (lw / spacing).ceil().max(1.0) as u32;
+    let ny = (lh / spacing).ceil().max(1.0) as u32;
+    let (cx, cy) = (lw * 0.5, lh * 0.5);
+    let mut list: Vec<(f32, Sprite, Tint)> = (0..nx * ny)
+        .into_par_iter()
+        .map(|i| {
+            let (gx, gy) = ((i % nx) as f32 * spacing + spacing * 0.5, (i / nx) as f32 * spacing + spacing * 0.5);
+            let (sx, sy) = b.to_px([gx as f64, gy as f64]);
+            // Depth cycles towards the viewer: z in [0, 1), perspective 1 / (1 - 0.9 z).
+            let z = (h(i, 1, seed) + t * speed * 0.25 + phase).rem_euclid(1.0);
+            let persp = 1.0 / (1.0 - 0.9 * z);
+            let jx = hs(i, 2, seed) * scatter * 0.01 * lw * 0.5;
+            let jy = hs(i, 3, seed) * scatter * 0.01 * lh * 0.5;
+            let x = cx + (gx - cx + jx) * persp;
+            let y = cy + (gy - cy + jy) * persp;
+            let (bx, by) = b.to_px([x as f64, y as f64]);
+            let r = spacing * 0.5 * size * persp * s;
+            let fade = (z * 8.0).min(1.0) * ((1.0 - z) * 6.0).min(1.0);
+            // The layer's colour at the grid point (none where it is clear).
+            (z, Sprite::new(bx as f32, by as f32, r, [0.0, 0.0, 0.0, fade], Shape::Disc), Tint::Source { x: sx, y: sy })
+        })
+        .collect();
+    list.sort_by(|a, b| a.0.total_cmp(&b.0));
+    let (sprites, tints) = list.into_iter().map(|(_, s, t)| (s, t)).unzip();
+    SpritePlan { sprites, tints, acc: Acc::Over, post: if blend > 0.0 { Post::Lerp(blend) } else { Post::Replace } }
+}
diff --git a/crates/effects/src/sim2.rs b/crates/effects/src/sim2.rs
index 939c36757..497b60f16 100644
--- a/crates/effects/src/sim2.rs
+++ b/crates/effects/src/sim2.rs
@@ -16,2683 +16,28 @@ use crate::sim::{Acc, Post, Shape, Sprite, SpritePlan, h, hs, pct, pt, raster, s
 use crate::util::{Plane, SimCache, gauss_plane, layer_or_self, params_key, unpremul};
 use crate::{Buf, EffectCtx, EffectSpec, col, num, p, popup, slider};
 
-// ------------------------------------------------------------------ 3D pieces
-
-pub(crate) type M3 = [[f64; 3]; 3];
-
-fn mat_mul(a: &M3, b: &M3) -> M3 {
-    std::array::from_fn(|i| std::array::from_fn(|j| (0..3).map(|k| a[i][k] * b[k][j]).sum()))
-}
-
-/// Rotation from Euler angles (radians), applied X then Y then Z.
-fn rot_xyz(x: f64, y: f64, z: f64) -> M3 {
-    let (sx, cx) = x.sin_cos();
-    let (sy, cy) = y.sin_cos();
-    let (sz, cz) = z.sin_cos();
-    let rx = [[1.0, 0.0, 0.0], [0.0, cx, -sx], [0.0, sx, cx]];
-    let ry = [[cy, 0.0, sy], [0.0, 1.0, 0.0], [-sy, 0.0, cy]];
-    let rz = [[cz, -sz, 0.0], [sz, cz, 0.0], [0.0, 0.0, 1.0]];
-    mat_mul(&rz, &mat_mul(&ry, &rx))
-}
-
-/// Rotation by `angle` about unit `axis` (Rodrigues).
-pub(crate) fn rot_axis(axis: [f64; 3], angle: f64) -> M3 {
-    let l = (axis[0] * axis[0] + axis[1] * axis[1] + axis[2] * axis[2]).sqrt();
-    if l < 1e-12 || angle == 0.0 {
-        return [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]];
-    }
-    let (x, y, z) = (axis[0] / l, axis[1] / l, axis[2] / l);
-    let (s, c) = angle.sin_cos();
-    let t = 1.0 - c;
-    [
-        [t * x * x + c, t * x * y - s * z, t * x * z + s * y],
-        [t * x * y + s * z, t * y * y + c, t * y * z - s * x],
-        [t * x * z - s * y, t * y * z + s * x, t * z * z + c],
-    ]
-}
-
-fn inv3(m: &M3) -> Option<M3> {
-    let det = m[0][0] * (m[1][1] * m[2][2] - m[1][2] * m[2][1]) - m[0][1] * (m[1][0] * m[2][2] - m[1][2] * m[2][0])
-        + m[0][2] * (m[1][0] * m[2][1] - m[1][1] * m[2][0]);
-    if det.abs() < 1e-12 {
-        return None;
-    }
-    let d = 1.0 / det;
-    Some([
-        [(m[1][1] * m[2][2] - m[1][2] * m[2][1]) * d, (m[0][2] * m[2][1] - m[0][1] * m[2][2]) * d, (m[0][1] * m[1][2] - m[0][2] * m[1][1]) * d],
-        [(m[1][2] * m[2][0] - m[1][0] * m[2][2]) * d, (m[0][0] * m[2][2] - m[0][2] * m[2][0]) * d, (m[0][2] * m[1][0] - m[0][0] * m[1][2]) * d],
-        [(m[1][0] * m[2][1] - m[1][1] * m[2][0]) * d, (m[0][1] * m[2][0] - m[0][0] * m[2][1]) * d, (m[0][0] * m[1][1] - m[0][1] * m[1][0]) * d],
-    ])
-}
-
-/// Perspective camera looking down +z at the layer plane z = 0, `d` pixels away, centred on
-/// `c` (buffer pixels): screen = c + (P - c) · d / (d + z).
-#[derive(Clone, Copy)]
-struct Cam {
-    c: [f64; 2],
-    d: f64,
-}
-
-impl Cam {
-    fn proj(self) -> Proj {
-        Proj::simple(self.c, self.d)
-    }
-}
-
-/// A planar textured piece ready to draw.
-#[derive(Clone, Copy, Debug)]
-pub struct Piece {
-    /// Screen (buffer px, homogeneous) → piece-local (a, b, w).
-    pub inv: [[f64; 3]; 3],
-    /// Rest centre of the piece in texture pixels.
-    pub c0: [f32; 2],
-    /// Convex polygon (texture pixels), counter-clockwise in y-down space.
-    pub poly: [[f32; 2]; 6],
-    pub n: u8,
-    pub bbox: [f32; 4],
-    pub shade: f32,
-    /// Lighting: colour multiplier and additive specular highlight.
-    pub tint: [f32; 3],
-    pub spec: [f32; 3],
-    pub alpha: f32,
-    /// Flat straight colour instead of the texture.
-    pub flat: Option<[f32; 3]>,
-    /// Facing away from the camera (draw the back texture).
-    pub back: bool,
-    /// Back faces sample their texture mirrored about the piece centre: 0 no, 1 vertically
-    /// (flipped about the X axis), 2 horizontally (about the Y axis).
-    pub back_mirror: u8,
-    depth: f64,
-}
-
-/// A piece texture: the layer itself or another image (buffer-aligned).
-#[derive(Clone, Debug)]
-pub enum PieceTex {
-    Layer,
-    Image(Image),
-}
-
-/// What a piece-drawing effect (Card Dance, Shatter, Card Wipe) draws this frame: pieces sorted
-/// far to near over a transparent frame, textured by `front` (and `back` for pieces facing
-/// away; none = they take `front`).
-#[derive(Clone, Debug)]
-pub struct PiecePlan {
-    pub pieces: Vec<Piece>,
-    pub front: PieceTex,
-    pub back: Option<PieceTex>,
-}
-
-impl PiecePlan {
-    /// Rasterise over a transparent frame of the layer `b`'s size.
-    pub fn finish(&self, mut b: Buf) -> Buf {
-        let mut out = Image::new(b.img.width, b.img.height);
-        let front = match &self.front {
-            PieceTex::Layer => &b.img,
-            PieceTex::Image(i) => i,
-        };
-        let back = self.back.as_ref().map(|t| match t {
-            PieceTex::Layer => &b.img,
-            PieceTex::Image(i) => i,
-        });
-        draw_pieces(&mut out, &self.pieces, front, back);
-        b.img = out;
-        b
-    }
-}
-
-/// The piece plan of Card Dance, Shatter (Rendered view) or Card Wipe for layer `b` (its pixels
-/// may be read: gradient maps and textures default to the layer), `None` for other effects or
-/// views drawn otherwise.
-pub fn piece_plan(id: &str, ctx: &EffectCtx, b: &Buf) -> Option<PiecePlan> {
-    match id {
-        "ec.sim.carddance" => Some(card_dance_plan(ctx, b)),
-        "ec.sim.shatter" if ctx.params.e("view") == 0 => match shatter_impl(ctx, b) {
-            ShatterPlan::Pieces(plan) => Some(plan),
-            ShatterPlan::Wire(_) => None,
-        },
-        "ec.transition.cardwipe" => crate::transition::card_wipe_plan(ctx, b),
-        _ => None,
-    }
-}
-
-impl Piece {
-    /// Place polygon `poly` (texture px, around rest centre `c0`) with rotation `r` and its
-    /// centre at 3D `pos` (buffer px; z away from the camera), seen through `cam`.
-    pub(crate) fn new(poly: &[[f32; 2]], c0: [f32; 2], r: &M3, pos: [f64; 3], cam: impl Into<Proj>) -> Option<Piece> {
-        let cam: Proj = cam.into();
-        let n = poly.len().min(6);
-        if n < 3 {
-            return None;
-        }
-        let m = &cam.m;
-        let row = |i: usize| -> [f64; 3] {
-            [
-                m[i][0] * r[0][0] + m[i][1] * r[1][0] + m[i][2] * r[2][0],
-                m[i][0] * r[0][1] + m[i][1] * r[1][1] + m[i][2] * r[2][1],
-                m[i][0] * pos[0] + m[i][1] * pos[1] + m[i][2] * pos[2] + m[i][3],
-            ]
-        };
-        let hm: M3 = [row(0), row(1), row(2)];
-        let mut bb = [f32::INFINITY, f32::INFINITY, f32::NEG_INFINITY, f32::NEG_INFINITY];
-        for v in &poly[..n] {
-            let (a, b) = ((v[0] - c0[0]) as f64, (v[1] - c0[1]) as f64);
-            let w = hm[2][0] * a + hm[2][1] * b + hm[2][2];
-            if w < cam.near {
-                return None;
-            }
-            let sx = ((hm[0][0] * a + hm[0][1] * b + hm[0][2]) / w) as f32;
-            let sy = ((hm[1][0] * a + hm[1][1] * b + hm[1][2]) / w) as f32;
-            bb = [bb[0].min(sx), bb[1].min(sy), bb[2].max(sx), bb[3].max(sy)];
-        }
-        let inv = inv3(&hm)?;
-        let mut pp = [[0.0f32; 2]; 6];
-        pp[..n].copy_from_slice(&poly[..n]);
-        // Normalise winding so "inside" is cross >= 0 for every edge.
-        let area: f32 = (0..n).map(|i| pp[i][0] * pp[(i + 1) % n][1] - pp[(i + 1) % n][0] * pp[i][1]).sum();
-        if area < 0.0 {
-            pp[..n].reverse();
-        }
-        // The front faces -z at rest; it faces the camera when its normal points at the eye.
-        let eye = cam.eye();
-        let nrm = [-r[0][2], -r[1][2], -r[2][2]];
-        let to_eye = [eye[0] - pos[0], eye[1] - pos[1], eye[2] - pos[2]];
-        let facing = nrm[0] * to_eye[0] + nrm[1] * to_eye[1] + nrm[2] * to_eye[2];
-        let depth = hm[2][2];
-        Some(Piece {
-            inv,
-            c0,
-            poly: pp,
-            n: n as u8,
-            bbox: [bb[0] - 1.0, bb[1] - 1.0, bb[2] + 1.0, bb[3] + 1.0],
-            shade: 1.0,
-            tint: [1.0; 3],
-            spec: [0.0; 3],
-            alpha: 1.0,
-            flat: None,
-            back: facing < 0.0,
-            back_mirror: 0,
-            depth,
-        })
-    }
-
-    /// Lambert factor of the piece normal against a light shining along +z.
-    fn facing(r: &M3) -> f32 {
-        r[2][2].abs() as f32
-    }
-
-    /// Light the piece (rotation `r`, centre `pos`) with Lighting / Material.
-    pub(crate) fn light(&mut self, l: &Lighting, r: &M3, pos: [f64; 3], eye: [f64; 3]) {
-        let (t, s) = l.shade([-r[0][2], -r[1][2], -r[2][2]], pos, eye);
-        self.tint = t;
-        self.spec = s;
-    }
-}
-
-impl From<Cam> for Proj {
-    fn from(c: Cam) -> Proj {
-        c.proj()
-    }
-}
-
-/// Draw pieces (already sorted far → near) over `out`.
-pub(crate) fn draw_pieces(out: &mut Image, pieces: &[Piece], front: &Image, back: Option<&Image>) {
-    raster(
-        out,
-        pieces,
-        |q| Some(q.bbox),
-        |q, x, y| {
-            let (xf, yf) = (x as f64, y as f64);
-            let m = &q.inv;
-            let w = m[2][0] * xf + m[2][1] * yf + m[2][2];
-            if w.abs() < 1e-12 {
-                return None;
-            }
-            let u = ((m[0][0] * xf + m[0][1] * yf + m[0][2]) / w) as f32 + q.c0[0];
-            let v = ((m[1][0] * xf + m[1][1] * yf + m[1][2]) / w) as f32 + q.c0[1];
-            let n = q.n as usize;
-            let mut md = f32::INFINITY;
-            for i in 0..n {
-                let a = q.poly[i];
-                let b = q.poly[(i + 1) % n];
-                let (ex, ey) = (b[0] - a[0], b[1] - a[1]);
-                let l = (ex * ex + ey * ey).sqrt().max(1e-6);
-                md = md.min((ex * (v - a[1]) - ey * (u - a[0])) / l);
-            }
-            // Coverage extends half a pixel past the edge so abutting pieces leave no seams.
-            let cov = (md + 1.0).clamp(0.0, 1.0);
-            if cov <= 0.0 {
-                return None;
-            }
-            let (c, a) = match q.flat {
-                Some(c) => (c, 1.0),
-                None => {
-                    let tex = if q.back { back.unwrap_or(front) } else { front };
-                    let (u, v) = match (q.back, q.back_mirror) {
-                        (true, 1) => (u, 2.0 * q.c0[1] - v),
-                        (true, 2) => (2.0 * q.c0[0] - u, v),
-                        _ => (u, v),
-                    };
-                    unpremul(tex.sample_bilinear(u as f64, v as f64))
-                }
-            };
-            let a = a * cov * q.alpha;
-            if a <= 1e-6 {
-                return None;
-            }
-            let k = q.shade;
-            let o: [f32; 3] = std::array::from_fn(|i| c[i] * k * q.tint[i] + q.spec[i]);
-            Some([o[0] * a, o[1] * a, o[2] * a, a])
-        },
-        Acc::Over,
-    );
-}
-
-pub(crate) fn sort_far_first(pieces: &mut [Piece]) {
-    pieces.sort_by(|a, b| b.depth.total_cmp(&a.depth));
-}
-
-// ------------------------------------------------------------------ CC Ball Action
-
-fn ball_action(ctx: &EffectCtx, b: Buf) -> Buf {
-    ball_action_plan(ctx, &b).finish(b)
-}
-
-/// CC Ball Action's balls (far to near), coloured by the layer's pixels.
-fn ball_action_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
-    let pr = ctx.params;
-    let scatter = pr.f("scatter") as f32;
-    let axis = pr.e("rotationAxis");
-    let rot = pr.f("rotation").to_radians();
-    let twist_prop = pr.e("twistProperty");
-    let twist = pr.f("twistAngle").to_radians();
-    let spacing = pr.f("gridSpacing").max(1.0) as f32;
-    let size = pr.f("ballSize") as f32 / 100.0;
-    let instab = pr.f("instabilityState").to_radians() as f32;
-    let seed = ctx.seed.wrapping_mul(0x2545f491);
-    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
-    let s = b.scale as f32;
-    let nx = (lw / spacing).ceil().max(1.0) as u32;
-    let ny = (lh / spacing).ceil().max(1.0) as u32;
-    let d = 2.0 * lw.max(lh) as f64;
-    let (cx, cy) = (lw as f64 * 0.5, lh as f64 * 0.5);
-    let src = &b.img;
-    let ax: [f64; 3] = match axis {
-        0 => [1.0, 0.0, 0.0],
-        1 => [0.0, 1.0, 0.0],
-        2 => [0.0, 0.0, 1.0],
-        3 => [1.0, 1.0, 0.0],
-        4 => [1.0, 0.0, 1.0],
-        5 => [0.0, 1.0, 1.0],
-        _ => [1.0, 1.0, 1.0],
-    };
-    let maxr = ((lw * lw + lh * lh).sqrt() * 0.5).max(1.0);
-    let mut balls: Vec<(f64, Sprite)> = (0..nx * ny)
-        .into_par_iter()
-        .filter_map(|i| {
-            let gx = (i % nx) as f32 * spacing + spacing * 0.5;
-            let gy = (i / nx) as f32 * spacing + spacing * 0.5;
-            let (sx, sy) = b.to_px([gx as f64, gy as f64]);
-            let (c, a) = unpremul(src.sample_bilinear(sx, sy));
-            if a <= 0.0 || size <= 0.0 {
-                return None;
-            }
-            let tp = match twist_prop {
-                0 => gx / lw.max(1.0),
-                1 => gy / lh.max(1.0),
-                2 => ((gx - cx as f32).hypot(gy - cy as f32)) / maxr,
-                _ => crate::util::rgb3([c[0], c[1], c[2], 0.0]).iter().sum::<f32>() / 3.0,
-            } as f64;
-            let ang = rot + twist * tp;
-            // Scatter: random 3D offsets whose direction drifts with the instability state.
-            let ph = h(i, 1, seed) * std::f32::consts::TAU + instab;
-            let sc = scatter * h(i, 2, seed);
-            let off = [(sc * ph.cos()) as f64, (sc * ph.sin()) as f64, (scatter * hs(i, 3, seed)) as f64];
-            let p0 = [gx as f64 - cx + off[0], gy as f64 - cy + off[1], off[2]];
-            let m = rot_axis(ax, ang);
-            let q: [f64; 3] = std::array::from_fn(|k| m[k][0] * p0[0] + m[k][1] * p0[1] + m[k][2] * p0[2]);
-            if d + q[2] <= d * 0.05 {
-                return None;
-            }
-            let persp = d / (d + q[2]);
-            let (bx, by) = b.to_px([cx + q[0] * persp, cy + q[1] * persp]);
-            let r = spacing * 0.5 * size * persp as f32 * s;
-            Some((q[2], Sprite::new(bx as f32, by as f32, r, [c[0], c[1], c[2], a], Shape::Sphere)))
-        })
-        .collect();
-    balls.sort_by(|a, b| b.0.total_cmp(&a.0));
-    let sprites: Vec<Sprite> = balls.into_iter().map(|(_, s)| s).collect();
-    SpritePlan { sprites, tints: vec![], acc: Acc::Over, post: Post::Replace }
-}
-
-// ------------------------------------------------------------------ CC Pixel Polly
-
-fn pixel_polly(ctx: &EffectCtx, b: Buf) -> Buf {
-    match pixel_polly_plan(ctx, &b) {
-        Some(plan) => plan.finish(b),
-        None => b,
-    }
-}
-
-/// CC Pixel Polly's pieces, `None` before Start Time (the layer as is).
-fn pixel_polly_plan(ctx: &EffectCtx, b: &Buf) -> Option<PiecePlan> {
-    let pr = ctx.params;
-    let t = ctx.time - pr.f("startTime");
-    if t <= 0.0 {
-        return None;
-    }
-    let force = pr.f("force");
-    let gravity = pr.f("gravity");
-    let spin = pr.f("spinning").to_radians();
-    let fc = pr.v2("forceCenter");
-    let dir_rand = pr.f("directionRandomness") / 100.0;
-    let spd_rand = pr.f("speedRandomness") / 100.0;
-    let g = pr.f("gridSpacing").max(1.0);
-    let object = pr.e("object");
-    let depth_sort = pr.b("enableDepthSort");
-    let seed = ctx.seed.wrapping_mul(0x632be5ab);
-    let [lw, lh] = ctx.layer_size;
-    let s = b.scale;
-    let cam = Cam { c: [b.offset[0] + lw * 0.5 * s, b.offset[1] + lh * 0.5 * s], d: 2.0 * lw.max(lh) * s };
-    let nx = (lw / g).ceil().max(1.0) as u32;
-    let ny = (lh / g).ceil().max(1.0) as u32;
-    let tri = object <= 1;
-    let textured = object == 1 || object == 3;
-    let maxd = lw.max(lh);
-    let src = &b.img;
-    let per = if tri { 2 } else { 1 };
-    let mut pieces: Vec<Piece> = (0..nx * ny * per)
-        .into_par_iter()
-        .filter_map(|i| {
-            let cell = i / per;
-            let (x0, y0) = ((cell % nx) as f64 * g, (cell / nx) as f64 * g);
-            let poly: Vec<[f64; 2]> = if !tri {
-                vec![[x0, y0], [x0 + g, y0], [x0 + g, y0 + g], [x0, y0 + g]]
-            } else if i % 2 == 0 {
-                vec![[x0, y0], [x0 + g, y0], [x0, y0 + g]]
-            } else {
-                vec![[x0 + g, y0], [x0 + g, y0 + g], [x0, y0 + g]]
-            };
-            let c = [poly.iter().map(|v| v[0]).sum::<f64>() / poly.len() as f64, poly.iter().map(|v| v[1]).sum::<f64>() / poly.len() as f64];
-            let (dx, dy) = (c[0] - fc[0], c[1] - fc[1]);
-            let dist = (dx * dx + dy * dy).sqrt().max(1e-6);
-            let ang = dy.atan2(dx) + dir_rand * std::f64::consts::PI * hs(i, 1, seed) as f64;
-            let speed = force / 100.0 * 0.6 * maxd / (1.0 + dist / (0.5 * maxd)) * (1.0 + spd_rand * hs(i, 2, seed) as f64);
-            let vz = -speed * 0.5 * h(i, 3, seed) as f64;
-            let pos = [c[0] + ang.cos() * speed * t, c[1] + ang.sin() * speed * t + 0.5 * gravity * 0.5 * lh * t * t, vz * t];
-            let axis = [hs(i, 4, seed) as f64, hs(i, 5, seed) as f64, hs(i, 6, seed) as f64];
-            let r = rot_axis(axis, t * (std::f64::consts::PI * h(i, 7, seed) as f64 + spin));
-            let tex: Vec<[f32; 2]> = poly.iter().map(|v| [(v[0] * s + b.offset[0]) as f32, (v[1] * s + b.offset[1]) as f32]).collect();
-            let c0 = [(c[0] * s + b.offset[0]) as f32, (c[1] * s + b.offset[1]) as f32];
-            let posb = [pos[0] * s + b.offset[0], pos[1] * s + b.offset[1], pos[2] * s];
-            let mut pc = Piece::new(&tex, c0, &r, posb, cam)?;
-            pc.shade = 0.35 + 0.65 * Piece::facing(&r);
-            if !textured {
-                let (cc, a) = unpremul(src.sample_bilinear(c0[0] as f64, c0[1] as f64));
-                if a <= 0.0 {
-                    return None;
-                }
-                pc.flat = Some(cc);
-                pc.alpha = a;
-            }
-            Some(pc)
-        })
-        .collect();
-    if depth_sort {
-        sort_far_first(&mut pieces);
-    }
-    Some(PiecePlan { pieces, front: PieceTex::Layer, back: None })
-}
-
-// ------------------------------------------------------------------ CC Scatterize
-
-fn scatterize(ctx: &EffectCtx, b: Buf) -> Buf {
-    match scatterize_plan(ctx, &b) {
-        Some(plan) => plan.finish(b),
-        None => b,
-    }
-}
-
-/// CC Scatterize's pixel dots, `None` when nothing moves (the layer as is).
-fn scatterize_plan(ctx: &EffectCtx, b: &Buf) -> Option<SpritePlan> {
-    let pr = ctx.params;
-    let scatter = pr.f("scatter") as f32;
-    let right = pr.f("rightTwist").to_radians();
-    let left = pr.f("leftTwist").to_radians();
-    if scatter == 0.0 && right == 0.0 && left == 0.0 {
-        return None;
-    }
-    let add = pr.e("transferMode") == 1;
-    let seed = ctx.seed.wrapping_mul(0x7feb352d);
-    let s = b.scale;
-    let (w, hh) = (b.img.width, b.img.height);
-    let (cx, cy) = (b.offset[0] + ctx.layer_size[0] * 0.5 * s, b.offset[1] + ctx.layer_size[1] * 0.5 * s);
-    let half = (ctx.layer_size[0] * 0.5 * s).max(1.0);
-    let d = 2.0 * ctx.layer_size[0].max(ctx.layer_size[1]) * s;
-    let src = &b.img;
-    let sprites: Vec<Sprite> = (0..w * hh)
-        .into_par_iter()
-        .filter_map(|i| {
-            let px = src.data[i as usize];
-            if px[3] <= 0.0 {
-                return None;
-            }
-            let (x, y) = ((i % w) as f64 + 0.5, (i / w) as f64 + 0.5);
-            // Twist about the horizontal axis through the centre, growing towards each side.
-            let k = ((x - cx) / half).abs().min(1.0);
-            let ang = if x < cx { left } else { right } * k;
-            let (sa, ca) = ang.sin_cos();
-            let (yy, zz) = ((y - cy) * ca, (y - cy) * sa);
-            let persp = d / (d + zz).max(d * 0.05);
-            let jx = hs(i, 1, seed) * scatter * s as f32;
-            let jy = hs(i, 2, seed) * scatter * s as f32;
-            let sx = cx + (x - cx) * persp + jx as f64;
-            let sy = cy + yy * persp + jy as f64;
-            let (c, a) = unpremul(px);
-            Some(Sprite::new(sx as f32, sy as f32, 0.6 * persp as f32, [c[0], c[1], c[2], a], Shape::Disc))
-        })
-        .collect();
-    Some(SpritePlan { sprites, tints: vec![], acc: if add { Acc::Add } else { Acc::Over }, post: Post::Replace })
-}
-
-/// What a particle effect that reads the layer's pixels draws this frame (CC Ball Action, CC
-/// Pixel Polly, CC Scatterize, Shatter's wireframe views), for layer `b`; `None` for other
-/// effects or a frame showing the layer as is.
-pub enum PixelPlan {
-    Sprites(SpritePlan),
-    Pieces(PiecePlan),
-}
-
-/// The [`PixelPlan`] of effect `id` for layer `b` (its pixels are read).
-pub fn pixel_plan(id: &str, ctx: &EffectCtx, b: &Buf) -> Option<PixelPlan> {
-    match id {
-        "ec.sim.ccballaction" => Some(PixelPlan::Sprites(ball_action_plan(ctx, b))),
-        "ec.sim.ccpixelpolly" => pixel_polly_plan(ctx, b).map(PixelPlan::Pieces),
-        "ec.sim.ccscatterize" => scatterize_plan(ctx, b).map(PixelPlan::Sprites),
-        "ec.sim.shatter" => Some(match shatter_impl(ctx, b) {
-            ShatterPlan::Pieces(plan) => PixelPlan::Pieces(plan),
-            ShatterPlan::Wire(plan) => PixelPlan::Sprites(plan),
-        }),
-        _ => None,
-    }
-}
-
-// ------------------------------------------------------------------ Card Dance
-
-const CD_SOURCES: &[&str] = &["None", "Intensity 1", "Red 1", "Green 1", "Blue 1", "Alpha 1", "Intensity 2", "Red 2", "Green 2", "Blue 2", "Alpha 2"];
-/// (param id prefix, twirl-down group match id) per transformed card property.
-const CD_PROPS: [(&str, &str); 8] = [
-    ("xPos", "xPosition"),
-    ("yPos", "yPosition"),
-    ("zPos", "zPosition"),
-    ("xRot", "xRotation"),
-    ("yRot", "yRotation"),
-    ("zRot", "zRotation"),
-    ("xScale", "xScale"),
-    ("yScale", "yScale"),
-];
-
-fn card_source(src: u32, g1: [f32; 4], g2: [f32; 4]) -> f32 {
-    let (c1, a1) = unpremul(g1);
-    let (c2, a2) = unpremul(g2);
-    let lum = |c: [f32; 3]| effectcraft_color::luminance(c[0], c[1], c[2]);
-    match src {
-        1 => lum(c1),
-        2 => c1[0],
-        3 => c1[1],
-        4 => c1[2],
-        5 => a1,
-        6 => lum(c2),
-        7 => c2[0],
-        8 => c2[1],
-        9 => c2[2],
-        10 => a2,
-        _ => 0.0,
-    }
-}
-
-fn card_dance(ctx: &EffectCtx, b: Buf) -> Buf {
-    card_dance_plan(ctx, &b).finish(b)
-}
-
-fn card_dance_plan(ctx: &EffectCtx, b: &Buf) -> PiecePlan {
-    let pr = ctx.params;
-    let rows = pr.f("rows").clamp(1.0, 1000.0) as u32;
-    let cols = if pr.e("rowsColumns") == 1 { rows } else { pr.f("columns").clamp(1.0, 1000.0) as u32 };
-    let g1 = layer_or_self(ctx, b, "gradientLayer1", true, true);
-    let g2 = layer_or_self(ctx, b, "gradientLayer2", true, true);
-    let back = ctx.layer_param("backLayer", true).map(|o| crate::util::fit_layer(ctx, b, &o, true));
-    let [lw, lh] = ctx.layer_size;
-    let s = b.scale;
-    let (cw, ch) = (lw / cols as f64, lh / rows as f64);
-    let cam = crate::card3d::projection(ctx, b);
-    let eye = cam.eye();
-    let light = Lighting::from(ctx, b);
-    let props: Vec<(u32, f64, f64)> =
-        CD_PROPS.iter().map(|(id, g)| (pr.e(&format!("{g}/{id}Source")), pr.f(&format!("{g}/{id}Multiplier")), pr.f(&format!("{g}/{id}Offset")))).collect();
-    let mut pieces: Vec<Piece> = (0..rows * cols)
-        .into_par_iter()
-        .filter_map(|i| {
-            let (cx0, cy0) = ((i % cols) as f64 * cw, (i / cols) as f64 * ch);
-            let c = [cx0 + cw * 0.5, cy0 + ch * 0.5];
-            let (bx, by) = (c[0] * s + b.offset[0], c[1] * s + b.offset[1]);
-            let (gp1, gp2) = (g1.sample_bilinear(bx, by), g2.sample_bilinear(bx, by));
-            let val = |k: usize| {
-                let (sr, m, o) = props[k];
-                o + m * card_source(sr, gp1, gp2) as f64
-            };
-            let (sx, sy) = (val(6), val(7));
-            let r = rot_xyz(val(3).to_radians(), val(4).to_radians(), val(5).to_radians());
-            let rs: M3 = std::array::from_fn(|k| [r[k][0] * sx, r[k][1] * sy, r[k][2]]);
-            let pos = [bx + val(0) * cw * s, by + val(1) * ch * s, val(2) * cw.max(ch) * s];
-            let (tx0, ty0) = ((cx0 * s + b.offset[0]) as f32, (cy0 * s + b.offset[1]) as f32);
-            let (tw, th) = ((cw * s) as f32, (ch * s) as f32);
-            let poly = [[tx0, ty0], [tx0 + tw, ty0], [tx0 + tw, ty0 + th], [tx0, ty0 + th]];
-            let mut pc = Piece::new(&poly, [bx as f32, by as f32], &rs, pos, cam)?;
-            pc.light(&light, &r, pos, eye);
-            Some(pc)
-        })
-        .collect();
-    sort_far_first(&mut pieces);
-    PiecePlan { pieces, front: PieceTex::Layer, back: back.map(PieceTex::Image) }
-}
-
-// ------------------------------------------------------------------ Shatter
-
-/// Shatter's Pattern options; the last, Custom, takes its pieces from Custom Shatter Map.
-const SHATTER_PATTERNS: &[&str] = &["Bricks", "Glass", "Hexagons", "Squares", "Triangles", "Custom"];
-
-/// Pattern cells (polygons in pattern space, before rotation) covering `[x0, x1]×[y0, y1]`.
-fn pattern_cells(kind: u32, cell: f64, x0: f64, y0: f64, x1: f64, y1: f64, seed: u32) -> Vec<Vec<[f64; 2]>> {
-    let mut out = Vec::new();
-    let i0 = (x0 / cell).floor() as i64 - 1;
-    let i1 = (x1 / cell).ceil() as i64 + 1;
-    let j0 = (y0 / cell).floor() as i64 - 1;
-    let j1 = (y1 / cell).ceil() as i64 + 1;
-    match kind {
-        0 => {
-            let bh = cell * 0.5;
-            let r0 = (y0 / bh).floor() as i64 - 1;
-            let r1 = (y1 / bh).ceil() as i64 + 1;
-            for r in r0..=r1 {
-                let sh = if r.rem_euclid(2) == 1 { cell * 0.5 } else { 0.0 };
-                for i in i0..=i1 {
-                    let (x, y) = (i as f64 * cell + sh, r as f64 * bh);
-                    out.push(vec![[x, y], [x + cell, y], [x + cell, y + bh], [x, y + bh]]);
-                }
-            }
-        }
-        1 => {
-            // Jittered lattice split into triangles along a random diagonal.
-            let jit = |i: i64, j: i64| -> [f64; 2] {
-                let (a, b) = (i as u32, j as u32);
-                [i as f64 * cell + hs(a, b.wrapping_add(17), seed) as f64 * cell * 0.35, j as f64 * cell + hs(a, b.wrapping_add(91), seed) as f64 * cell * 0.35]
-            };
-            for j in j0..=j1 {
-                for i in i0..=i1 {
-                    let (p00, p10, p11, p01) = (jit(i, j), jit(i + 1, j), jit(i + 1, j + 1), jit(i, j + 1));
-                    if h(i as u32, j as u32, seed ^ 0x55) < 0.5 {
-                        out.push(vec![p00, p10, p11]);
-                        out.push(vec![p00, p11, p01]);
-                    } else {
-                        out.push(vec![p00, p10, p01]);
-                        out.push(vec![p10, p11, p01]);
-                    }
-                }
-            }
-        }
-        2 => {
-            let r = cell / 3f64.sqrt();
-            let dx = 1.5 * r;
-            let dy = 3f64.sqrt() * r;
-            let c0 = (x0 / dx).floor() as i64 - 1;
-            let c1 = (x1 / dx).ceil() as i64 + 1;
-            let rr0 = (y0 / dy).floor() as i64 - 1;
-            let rr1 = (y1 / dy).ceil() as i64 + 1;
-            for ci in c0..=c1 {
-                for rj in rr0..=rr1 {
-                    let cx = ci as f64 * dx;
-                    let cy = (rj as f64 + if ci.rem_euclid(2) == 1 { 0.5 } else { 0.0 }) * dy;
-                    out.push(
-                        (0..6)
-                            .map(|k| {
-                                let a = k as f64 * std::f64::consts::PI / 3.0;
-                                [cx + r * a.cos(), cy + r * a.sin()]
-                            })
-                            .collect(),
-                    );
-                }
-            }
-        }
-        3 => {
-            for j in j0..=j1 {
-                for i in i0..=i1 {
-                    let (x, y) = (i as f64 * cell, j as f64 * cell);
-                    out.push(vec![[x, y], [x + cell, y], [x + cell, y + cell], [x, y + cell]]);
-                }
-            }
-        }
-        _ => {
-            for j in j0..=j1 {
-                for i in i0..=i1 {
-                    let (x, y) = (i as f64 * cell, j as f64 * cell);
-                    if (i + j).rem_euclid(2) == 0 {
-                        out.push(vec![[x, y], [x + cell, y], [x, y + cell]]);
-                        out.push(vec![[x + cell, y], [x + cell, y + cell], [x, y + cell]]);
-                    } else {
-                        out.push(vec![[x, y], [x + cell, y], [x + cell, y + cell]]);
-                        out.push(vec![[x, y], [x + cell, y + cell], [x, y + cell]]);
-                    }
-                }
-            }
-        }
-    }
-    out
-}
-
-/// `∫0^t e^{-ks} ds` and `∫0^t ∫0^u e^{-ks} ds du` (drag-damped ballistic factors).
-fn drag_factors(k: f64, t: f64) -> (f64, f64) {
-    if k < 1e-6 {
-        (t, 0.5 * t * t)
-    } else {
-        let e = (-k * t).exp();
-        ((1.0 - e) / k, t / k - (1.0 - e) / (k * k))
-    }
-}
-/// Shatter's Front / Side / Back Mode options.
-const SHATTER_TEXTURE_MODES: [&str; 3] = ["Color", "Layer", "Tinted Layer"];
-
-/// One face's texture: a flat colour, a layer, or a layer tinted by the Textures colour.
-struct Face {
-    mode: u32,
-    img: Option<Image>,
-}
-
-impl Face {
-    fn from(ctx: &EffectCtx, b: &Buf, mode: &str, layer: &str, default_mode: u32) -> Face {
-        let mode = ctx.params.get(mode).map(|v| v.as_enum()).unwrap_or(default_mode);
-        // A face layer of None is the effect's own layer.
-        let img = (mode != 0).then(|| layer_or_self(ctx, b, layer, true, true));
-        Face { mode, img }
-    }
-}
-
-/// Group key of a Custom Shatter Map colour (pieces of one colour break as one).
-fn map_key(c: [f32; 4]) -> u32 {
-    let (c, a) = unpremul(c);
-    if a < 0.5 {
-        return u32::MAX;
-    }
-    let q = |v: f32| ((v.clamp(0.0, 1.0) * 15.0).round() as u32) & 15;
-    q(c[0]) << 8 | q(c[1]) << 4 | q(c[2])
-}
-
-fn shatter(ctx: &EffectCtx, b: Buf) -> Buf {
-    match shatter_impl(ctx, &b) {
-        ShatterPlan::Pieces(plan) => plan.finish(b),
-        ShatterPlan::Wire(plan) => plan.finish(b),
-    }
-}
-
-/// What Shatter draws: the pieces (Rendered view) or the wireframe lines.
-enum ShatterPlan {
-    Pieces(PiecePlan),
-    Wire(SpritePlan),
-}
-
-fn shatter_impl(ctx: &EffectCtx, b: &Buf) -> ShatterPlan {
-    let pr = ctx.params;
-    let view = pr.e("view");
-    let render = pr.e("render");
-    let kind = pr.e("shape/pattern");
-    let custom = kind as usize == SHATTER_PATTERNS.len() - 1;
-    let reps = pr.f("shape/repetitions").clamp(1.0, 500.0);
-    let dir = pr.f("shape/direction").to_radians();
-    let origin = pr.v2("shape/origin");
-    let forces = [
-        (pr.v2("force1/force1Position"), pr.f("force1/force1Depth"), pr.f("force1/force1Radius"), pr.f("force1/force1Strength")),
-        (pr.v2("force2/force2Position"), pr.f("force2/force2Depth"), pr.f("force2/force2Radius"), pr.f("force2/force2Strength")),
-    ];
-    let rot_speed = pr.f("physics/rotationSpeed");
-    let tumble = pr.e("physics/tumbleAxis");
-    let randomness = pr.f("physics/randomness");
-    let k = pr.f("physics/viscosity").max(0.0) * 5.0;
-    let mass_var = pr.f("physics/massVariance") / 100.0;
-    let gravity = pr.f("physics/gravity");
-    let gdir = pr.f("physics/gravityDirection").to_radians();
-    let ginc = pr.f("physics/gravityInclination").to_radians();
-    let seed = (pr.f("randomSeed") as u32).wrapping_mul(0x9e3779b1) ^ ctx.seed;
-    let [lw, lh] = ctx.layer_size;
-    let s = b.scale;
-    let t = ctx.time.max(0.0);
-    let unit = lw * 0.1;
-    let cell = lw / reps;
-    let extrude = pr.f("shape/extrusionDepth").max(0.0) * cell * s;
-    let cam = crate::card3d::projection(ctx, b);
-    let eye = cam.eye();
-    let light = Lighting::from(ctx, b);
-    // Gradient: with a gradient layer only pieces at least as bright as 1 − Shatter Threshold
-    // (Invert Gradient: as dark) break.
-    let gradient = ctx.layer_param("gradient/gradientLayer", true).map(|o| crate::util::fit_layer(ctx, b, &o, true));
-    let threshold = pr.get("gradient/shatterThreshold").map(Value::as_f64).unwrap_or(0.0) / 100.0;
-    let invert_gradient = pr.b("gradient/invertGradient");
-    // Textures.
-    let tex_color = pr.get("textures/color").map(|v| v.as_color()).unwrap_or([1.0; 4]);
-    let tex_opacity = pr.get("textures/opacity").map(Value::as_f64).unwrap_or(1.0).clamp(0.0, 1.0) as f32;
-    let front = Face::from(ctx, b, "textures/frontMode", "textures/frontLayer", 1);
-    let side = Face::from(ctx, b, "textures/sideMode", "textures/sideLayer", 0);
-    let backf = Face::from(ctx, b, "textures/backMode", "textures/backLayer", 1);
-    let custom_map = custom.then(|| layer_or_self(ctx, b, "shape/customShatterMap", true, true));
-    let white_fixed = pr.b("shape/whiteTilesFixed");
-    let (sd, cd) = dir.sin_cos();
-    let to_layer = |q: [f64; 2]| [origin[0] + q[0] * cd - q[1] * sd, origin[1] + q[0] * sd + q[1] * cd];
-    // Pattern-space bounds of the layer rectangle.
-    let corners = [[0.0, 0.0], [lw, 0.0], [lw, lh], [0.0, lh]].map(|c: [f64; 2]| {
-        let (dx, dy) = (c[0] - origin[0], c[1] - origin[1]);
-        [dx * cd + dy * sd, -dx * sd + dy * cd]
-    });
-    let (px0, px1) = (corners.iter().map(|c| c[0]).fold(f64::INFINITY, f64::min), corners.iter().map(|c| c[0]).fold(f64::NEG_INFINITY, f64::max));
-    let (py0, py1) = (corners.iter().map(|c| c[1]).fold(f64::INFINITY, f64::min), corners.iter().map(|c| c[1]).fold(f64::NEG_INFINITY, f64::max));
-    // Custom Shatter Map: square cells grouped by the map's colour.
-    let cells = pattern_cells(if custom { 3 } else { kind }, cell, px0, py0, px1, py1, seed);
-    let polys: Vec<Vec<[f64; 2]>> = cells.iter().map(|poly| poly.iter().map(|&q| to_layer(q)).collect()).collect();
-    let centre = |lp: &[[f64; 2]]| [lp.iter().map(|v| v[0]).sum::<f64>() / lp.len() as f64, lp.iter().map(|v| v[1]).sum::<f64>() / lp.len() as f64];
-    let keys: Vec<u32> = match &custom_map {
-        Some(m) => polys
-            .iter()
-            .map(|lp| {
-                let c = centre(lp);
-                map_key(m.sample_bilinear(c[0] * s + b.offset[0], c[1] * s + b.offset[1]))
-            })
-            .collect(),
-        None => (0..polys.len() as u32).collect(),
-    };
-    // Group centres (custom map) — each group moves as one rigid piece.
-    let mut groups: std::collections::HashMap<u32, ([f64; 2], f64)> = std::collections::HashMap::new();
-    for (lp, &key) in polys.iter().zip(&keys) {
-        let c = centre(lp);
-        let e = groups.entry(key).or_insert(([0.0; 2], 0.0));
-        e.0[0] += c[0];
-        e.0[1] += c[1];
-        e.1 += 1.0;
-    }
-    let g3 = [gdir.sin() * ginc.cos() * gravity * unit, -gdir.cos() * ginc.cos() * gravity * unit, ginc.sin() * gravity * unit];
-    let mut pieces: Vec<Piece> = polys
-        .par_iter()
-        .zip(keys.par_iter())
-        .flat_map_iter(|(lp, &key)| {
-            let mut out: Vec<Piece> = vec![];
-            let (mnx, mxx) = (lp.iter().map(|v| v[0]).fold(f64::INFINITY, f64::min), lp.iter().map(|v| v[0]).fold(f64::NEG_INFINITY, f64::max));
-            let (mny, mxy) = (lp.iter().map(|v| v[1]).fold(f64::INFINITY, f64::min), lp.iter().map(|v| v[1]).fold(f64::NEG_INFINITY, f64::max));
-            if mxx < 0.0 || mxy < 0.0 || mnx > lw || mny > lh || key == u32::MAX {
-                return out.into_iter();
-            }
-            let pc_c = centre(lp);
-            let (gsum, gn) = groups[&key];
-            let gc = [gsum[0] / gn, gsum[1] / gn];
-            let i = key;
-            // Broken when inside a force sphere (centred `depth` in front of the layer).
-            let mut v = [0.0f64; 3];
-            let mut broken = false;
-            for (fp, fd, fr, fs) in forces {
-                let rad = fr * lw;
-                if rad <= 0.0 {
-                    continue;
-                }
-                let dv = [gc[0] - fp[0], gc[1] - fp[1], fd * lw];
-                let dist = (dv[0] * dv[0] + dv[1] * dv[1] + dv[2] * dv[2]).sqrt();
-                if dist < rad {
-                    broken = true;
-                    let f = fs * (1.0 - dist / rad) * unit / dist.max(1e-6);
-                    for q in 0..3 {
-                        v[q] += dv[q] * f;
-                    }
-                }
-            }
-            if broken && let Some(g) = &gradient {
-                let (c, _) = unpremul(g.sample_bilinear(gc[0] * s + b.offset[0], gc[1] * s + b.offset[1]));
-                let mut l = effectcraft_color::luminance(c[0], c[1], c[2]).clamp(0.0, 1.0) as f64;
-                if invert_gradient {
-                    l = 1.0 - l;
-                }
-                broken = threshold > 0.0 && l >= 1.0 - threshold;
-            }
-            if broken && custom && white_fixed && key == 0xfff {
-                broken = false;
-            }
-            if (broken && render == 1) || (!broken && render == 2) {
-                return out.into_iter();
-            }
-            let mut gpos = [gc[0], gc[1], 0.0];
-            let mut r = rot_axis([1.0, 0.0, 0.0], 0.0);
-            let moving = broken && t > 0.0;
-            if moving {
-                let mass = 1.0 + mass_var * hs(i, 1, seed) as f64;
-                for q in 0..3 {
-                    v[q] = v[q] / mass + randomness * unit * hs(i, 2 + q as u32, seed) as f64 * 2.0;
-                }
-                let (f1, f2) = drag_factors(k, t);
-                for q in 0..3 {
-                    gpos[q] += v[q] * f1 + g3[q] * f2;
-                }
-                let axis = match tumble {
-                    1 => [0.0, 0.0, 0.0],
-                    2 => [1.0, 0.0, 0.0],
-                    3 => [0.0, 1.0, 0.0],
-                    4 => [0.0, 0.0, 1.0],
-                    5 => [hs(i, 6, seed) as f64, hs(i, 7, seed) as f64, 0.0],
-                    6 => [hs(i, 6, seed) as f64, 0.0, hs(i, 8, seed) as f64],
-                    7 => [0.0, hs(i, 7, seed) as f64, hs(i, 8, seed) as f64],
-                    _ => [hs(i, 6, seed) as f64, hs(i, 7, seed) as f64, hs(i, 8, seed) as f64],
-                };
-                let speed = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt() / unit;
-                let omega = rot_speed * std::f64::consts::TAU * (0.5 + h(i, 9, seed) as f64) * speed.min(10.0);
-                r = rot_axis(axis, omega * f1);
-            }
-            // The piece's centre: its offset from the group centre, rotated with the group.
-            let off = [pc_c[0] - gc[0], pc_c[1] - gc[1], 0.0];
-            let pos: [f64; 3] = std::array::from_fn(|q| gpos[q] + (0..3).map(|k| r[q][k] * off[k]).sum::<f64>());
-            let tex: Vec<[f32; 2]> = lp.iter().map(|v| [(v[0] * s + b.offset[0]) as f32, (v[1] * s + b.offset[1]) as f32]).collect();
-            let c0 = [(pc_c[0] * s + b.offset[0]) as f32, (pc_c[1] * s + b.offset[1]) as f32];
-            let posb = [pos[0] * s + b.offset[0], pos[1] * s + b.offset[1], pos[2] * s];
-            let Some(mut pc) = Piece::new(&tex, c0, &r, posb, cam) else { return out.into_iter() };
-            pc.light(&light, &r, posb, eye);
-            pc.alpha = tex_opacity;
-            let face = if pc.back { &backf } else { &front };
-            if face.mode == 0 {
-                pc.flat = Some([tex_color[0], tex_color[1], tex_color[2]]);
-            } else if face.mode == 2 {
-                pc.tint = std::array::from_fn(|q| pc.tint[q] * tex_color[q]);
-            }
-            // Extrusion: the sides of a moving piece, from its front outline back by the depth.
-            if moving && extrude > 0.0 {
-                let nb = [r[0][2], r[1][2], r[2][2]];
-                let n = tex.len();
-                for e in 0..n {
-                    let (a, bv) = (tex[e], tex[(e + 1) % n]);
-                    let ed = [(bv[0] - a[0]) as f64, (bv[1] - a[1]) as f64];
-                    let len = (ed[0] * ed[0] + ed[1] * ed[1]).sqrt();
-                    if len < 1e-6 {
-                        continue;
-                    }
-                    let ew: [f64; 3] = std::array::from_fn(|q| (r[q][0] * ed[0] + r[q][1] * ed[1]) / len);
-                    let third = [ew[1] * nb[2] - ew[2] * nb[1], ew[2] * nb[0] - ew[0] * nb[2], ew[0] * nb[1] - ew[1] * nb[0]];
-                    let rs: M3 = std::array::from_fn(|q| [ew[q], nb[q], third[q]]);
-                    // Side centre in world: edge midpoint (world) plus half the depth backwards.
-                    let mid = [((a[0] + bv[0]) * 0.5 - c0[0]) as f64, ((a[1] + bv[1]) * 0.5 - c0[1]) as f64];
-                    let mw: [f64; 3] = std::array::from_fn(|q| posb[q] + r[q][0] * mid[0] + r[q][1] * mid[1] + nb[q] * extrude * 0.5);
-                    let (hl, hd) = ((len * 0.5) as f32, (extrude * 0.5) as f32);
-                    let cs = [(a[0] + bv[0]) * 0.5, (a[1] + bv[1]) * 0.5];
-                    let quad = [[cs[0] - hl, cs[1] - hd], [cs[0] + hl, cs[1] - hd], [cs[0] + hl, cs[1] + hd], [cs[0] - hl, cs[1] + hd]];
-                    if let Some(mut sp) = Piece::new(&quad, cs, &rs, mw, cam) {
-                        sp.light(&light, &rs, mw, eye);
-                        sp.alpha = tex_opacity;
-                        let colour = match (&side.img, side.mode) {
-                            (Some(img), m) if m != 0 => {
-                                let (c, _) = unpremul(img.sample_bilinear(cs[0] as f64, cs[1] as f64));
-                                if m == 2 { std::array::from_fn(|q| c[q] * tex_color[q]) } else { c }
-                            }
-                            _ => [tex_color[0], tex_color[1], tex_color[2]],
-                        };
-                        sp.flat = Some(colour);
-                        out.push(sp);
-                    }
-                }
-            }
-            out.push(pc);
-            out.into_iter()
-        })
-        .collect();
-    sort_far_first(&mut pieces);
-    if view == 0 {
-        let tex = |i: &Option<Image>| i.clone().map(PieceTex::Image);
-        let front_t = tex(&front.img).unwrap_or(PieceTex::Layer);
-        let back_t = tex(&backf.img).unwrap_or_else(|| front_t.clone());
-        return ShatterPlan::Pieces(PiecePlan { pieces, front: front_t, back: Some(back_t) });
-    }
-    {
-        // Wireframes: piece outlines (front view: at rest; otherwise animated), plus forces.
-        let animated = view == 2 || view == 4;
-        let mut lines = Vec::new();
-        for pc in &pieces {
-            let n = pc.n as usize;
-            let pts: Vec<[f32; 2]> = if animated {
-                let fw = inv3(&pc.inv);
-                match fw {
-                    Some(m) => pc.poly[..n]
-                        .iter()
-                        .map(|v| {
-                            let (a, bb) = ((v[0] - pc.c0[0]) as f64, (v[1] - pc.c0[1]) as f64);
-                            let w = m[2][0] * a + m[2][1] * bb + m[2][2];
-                            [((m[0][0] * a + m[0][1] * bb + m[0][2]) / w) as f32, ((m[1][0] * a + m[1][1] * bb + m[1][2]) / w) as f32]
-                        })
-                        .collect(),
-                    None => continue,
-                }
-            } else {
-                pc.poly[..n].to_vec()
-            };
-            for e in 0..n {
-                let (a, c) = (pts[e], pts[(e + 1) % n]);
-                lines.push(Sprite::new(a[0], a[1], 0.5, [0.75, 0.85, 1.0, 1.0], Shape::Line { dx: c[0] - a[0], dy: c[1] - a[1] }));
-            }
-        }
-        if view >= 3 {
-            for (fp, _, fr, _) in forces {
-                let (fx, fy) = b.to_px(fp);
-                let rad = fr * lw * s;
-                for k in 0..64 {
-                    let (a0, a1) = (k as f64 / 64.0 * std::f64::consts::TAU, (k + 1) as f64 / 64.0 * std::f64::consts::TAU);
-                    let (x0, y0) = (fx + rad * a0.cos(), fy + rad * a0.sin());
-                    let (x1, y1) = (fx + rad * a1.cos(), fy + rad * a1.sin());
-                    lines.push(Sprite::new(x0 as f32, y0 as f32, 0.5, [1.0, 0.3, 0.3, 1.0], Shape::Line { dx: (x1 - x0) as f32, dy: (y1 - y0) as f32 }));
-                }
-            }
-        }
-        ShatterPlan::Wire(SpritePlan { sprites: lines, tints: vec![], acc: Acc::Over, post: Post::Replace })
-    }
-}
-
-// ------------------------------------------------------------------ Caustics
-
-/// Sample with repeat mode: 0 Once (transparent outside), 1 Tiled, 2 Reflected.
-fn sample_repeat(img: &Image, x: f64, y: f64, mode: u32) -> Px {
-    let (w, hh) = (img.width as f64, img.height as f64);
-    match mode {
-        1 => img.sample_bilinear_clamped(x.rem_euclid(w), y.rem_euclid(hh)),
-        2 => {
-            let m = |v: f64, n: f64| {
-                let r = v.rem_euclid(2.0 * n);
-                if r > n { 2.0 * n - r } else { r }
-            };
-            img.sample_bilinear_clamped(m(x, w), m(y, hh))
-        }
-        _ => img.sample_bilinear(x, y),
-    }
-}
-
-/// Everything Caustics' per-pixel pass needs, prepared on the CPU (the other layers it reads
-/// and the parameter conversions); the layer's own pixels are not read.
-pub struct CausticsSetup {
-    /// The Bottom layer fitted to the buffer, `None` = the layer itself.
-    pub bottom: Option<Image>,
-    /// Gaussian σ (buffer px) blurring the bottom (transparent edges), 0 = none.
-    pub bottom_sigma: f64,
-    /// The water surface's height field (smoothed luminance), `None` = flat.
-    pub height: Option<Plane>,
-    /// The Sky layer fitted to the buffer.
-    pub sky: Option<Image>,
-    pub scaling: f64,
-    pub repeat: u32,
-    pub wave_h: f64,
-    /// Displacement per unit of height gradient.
-    pub k: f64,
-    /// Layer centre (buffer px).
-    pub cx: f64,
-    pub cy: f64,
-    /// Layer width (buffer px).
-    pub lw: f64,
-    pub surf: [f32; 4],
-    pub surf_op: f32,
-    pub cstr: f32,
-    pub lc: [f32; 4],
-    pub li: f32,
-    /// Light position (buffer px) and height (layer widths); `point` = from the position to
-    /// each pixel, else one direction from above the layer centre.
-    pub lx: f64,
-    pub ly: f64,
-    pub lheight: f64,
-    pub point: bool,
-    pub ambient: f32,
-    pub diffuse: f32,
-    pub specular: f32,
-    pub sharp: f32,
-    pub sky_scaling: f64,
-    pub sky_repeat: u32,
-    pub sky_int: f32,
-    pub convergence: f64,
-}
-
-/// Caustics' setup for layer geometry `b` (see [`CausticsSetup`]).
-pub fn caustics_setup(ctx: &EffectCtx, b: &Buf) -> CausticsSetup {
-    let pr = ctx.params;
-    let s = b.scale;
-    let bottom = ctx.layer_param("bottom/bottom", true).map(|o| crate::util::fit_layer(ctx, b, &o, pr.e("bottom/bottomSizeDiffers") == 1));
-    let blur = pr.f("bottom/blur") * s;
-    let wave_h = pr.f("water/waveHeight");
-    let smoothing = pr.f("water/smoothing") * s;
-    let depth = pr.f("water/waterDepth");
-    let ior = pr.f("water/refractiveIndex").max(1.0);
-    let lpos = pr.v2("lighting/lightPosition");
-    // Height field of the water surface (luminance of the chosen layer; none = flat).
-    let height = ctx.layer_param("water/waterSurface", true).map(|o| {
-        let img = crate::util::fit_layer(ctx, b, &o, true);
-        let pl = Plane::luma(&img);
-        if smoothing > 0.05 { gauss_plane(&pl, smoothing * 0.5, smoothing * 0.5) } else { pl }
-    });
-    let lw = ctx.layer_size[0] * s;
-    let k = wave_h * depth * (1.0 - 1.0 / ior) * lw * 2.0;
-    let (cx, cy) = (b.offset[0] + ctx.layer_size[0] * 0.5 * s, b.offset[1] + ctx.layer_size[1] * 0.5 * s);
-    let (lx, ly) = b.to_px(lpos);
-    let (lc, li, lheight) = (pr.color("lighting/lightColor"), pr.f("lighting/lightIntensity") as f32, pr.f("lighting/lightHeight").max(0.01));
-    // Light Type: Distant Source (one direction, from the light position above the layer
-    // centre), Point Source (from the light position to each pixel) or First Comp Light.
-    let light_type = pr.e("lighting/lightType");
-    let comp_light = if light_type == 2 { ctx.env.host.and_then(|h| h.comp_scene()).and_then(|sc| sc.light) } else { None };
-    let (lc, li, lx, ly, lheight, point) = match (light_type, comp_light) {
-        (2, Some(l)) => {
-            let c = [l.color[0], l.color[1], l.color[2], 1.0];
-            // Comp space: z away from the viewer; the light above the water is at −z.
-            let (px, py) = (l.pos[0] * s + b.offset[0], l.pos[1] * s + b.offset[1]);
-            (c, li, px, py, (-l.pos[2] / ctx.layer_size[0].max(1.0)).max(0.01), l.kind == 1)
-        }
-        (2, None) => (lc, 0.0, lx, ly, lheight, false),
-        (1, _) => (lc, li, lx, ly, lheight, true),
-        _ => (lc, li, lx, ly, lheight, false),
-    };
-    // Sky: the layer the water surface reflects (Surface Opacity 1 = a mirror of it).
-    let sky = ctx.layer_param("sky/sky", true).map(|o| crate::util::fit_layer(ctx, b, &o, pr.e("sky/skySizeDiffers") == 1));
-    CausticsSetup {
-        bottom,
-        bottom_sigma: if blur > 0.05 { blur * 0.5 } else { 0.0 },
-        height,
-        sky,
-        scaling: pr.f("bottom/scaling").max(0.01),
-        repeat: pr.e("bottom/repeatMode"),
-        wave_h,
-        k,
-        cx,
-        cy,
-        lw,
-        surf: pr.color("water/surfaceColor"),
-        surf_op: pr.f("water/surfaceOpacity") as f32,
-        cstr: pr.f("water/causticsStrength") as f32,
-        lc,
-        li,
-        lx,
-        ly,
-        lheight,
-        point,
-        ambient: pr.f("lighting/ambientLight") as f32,
-        diffuse: pr.f("material/diffuse") as f32,
-        specular: pr.f("material/specular") as f32,
-        sharp: pr.f("material/highlightSharpness").max(1.0) as f32,
-        sky_scaling: pr.get("sky/scaling").map(Value::as_f64).unwrap_or(1.0).max(0.01),
-        sky_repeat: pr.e("sky/repeatMode"),
-        sky_int: pr.get("sky/intensity").map(Value::as_f64).unwrap_or(0.3) as f32,
-        convergence: pr.get("sky/convergence").map(Value::as_f64).unwrap_or(0.5).clamp(0.0, 1.0),
-    }
-}
-
-fn caustics(ctx: &EffectCtx, mut b: Buf) -> Buf {
-    let st = caustics_setup(ctx, &b);
-    let mut bottom = st.bottom.clone().unwrap_or_else(|| b.img.clone());
-    if st.bottom_sigma > 0.0 {
-        bottom = effectcraft_raster::gaussian_blur(&bottom, st.bottom_sigma, st.bottom_sigma, false);
-    }
-    let CausticsSetup {
-        scaling,
-        repeat,
-        wave_h,
-        k,
-        cx,
-        cy,
-        lw,
-        surf,
-        surf_op,
-        cstr,
-        lc,
-        li,
-        lx,
-        ly,
-        lheight,
-        point,
-        ambient,
-        diffuse,
-        specular,
-        sharp,
-        sky_scaling,
-        sky_repeat,
-        sky_int,
-        convergence,
-        ..
-    } = st;
-    let (height, sky) = (&st.height, &st.sky);
-    let (w, hh) = (b.img.width as usize, b.img.height as usize);
-    let norm3 = |v: [f64; 3]| {
-        let n = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt().max(1e-12);
-        [(v[0] / n) as f32, (v[1] / n) as f32, (v[2] / n) as f32]
-    };
-    let lv_at = |x: f64, y: f64| {
-        if point {
-            norm3([(lx - x) / lw.max(1.0), (ly - y) / lw.max(1.0), lheight])
-        } else {
-            norm3([(lx - cx) / lw.max(1.0), (ly - cy) / lw.max(1.0), lheight])
-        }
-    };
-    let grad = |x: usize, y: usize| -> (f64, f64) {
-        match height {
-            Some(pl) => {
-                let gx = (pl.get_clamped(x as i64 + 1, y as i64) - pl.get_clamped(x as i64 - 1, y as i64)) as f64 * 0.5;
-                let gy = (pl.get_clamped(x as i64, y as i64 + 1) - pl.get_clamped(x as i64, y as i64 - 1)) as f64 * 0.5;
-                (gx, gy)
-            }
-            None => (0.0, 0.0),
-        }
-    };
-    // Displacement and its Jacobian (caustic focusing) per pixel.
-    let disp: Vec<(f64, f64)> = (0..w * hh)
-        .into_par_iter()
-        .map(|i| {
-            let (gx, gy) = grad(i % w, i / w);
-            (-gx * k, -gy * k)
-        })
-        .collect();
-    b.img.rows_mut().for_each(|(y, row)| {
-        for (x, px) in row.iter_mut().enumerate() {
-            let i = y * w + x;
-            let (dx, dy) = disp[i];
-            let d = |xx: usize, yy: usize| disp[yy.min(hh - 1) * w + xx.min(w - 1)];
-            let (dxr, _) = d(x + 1, y);
-            let (_, dyd) = d(x, y + 1);
-            let (dxl, _) = d(x.saturating_sub(1), y);
-            let (_, dyu) = d(x, y.saturating_sub(1));
-            let jac = (1.0 + (dxr - dxl) * 0.5) * (1.0 + (dyd - dyu) * 0.5);
-            let focus = ((1.0 / jac.abs().max(0.2)) as f32 - 1.0).clamp(-1.0, 4.0);
-            let sx = cx + (x as f64 + 0.5 + dx - cx) / scaling;
-            let sy = cy + (y as f64 + 0.5 + dy - cy) / scaling;
-            let p = sample_repeat(&bottom, sx, sy, repeat);
-            let (c, a) = unpremul(p);
-            let (gx, gy) = grad(x, y);
-            let n = {
-                let v = [-gx * wave_h * 20.0, -gy * wave_h * 20.0, 1.0];
-                let m = (v[0] * v[0] + v[1] * v[1] + 1.0).sqrt();
-                [(v[0] / m) as f32, (v[1] / m) as f32, (v[2] / m) as f32]
-            };
-            let lv = lv_at(x as f64 + 0.5, y as f64 + 0.5);
-            let nl = (n[0] * lv[0] + n[1] * lv[1] + n[2] * lv[2]).max(0.0);
-            let hv = {
-                let v = [lv[0], lv[1], lv[2] + 1.0];
-                let m = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt();
-                [v[0] / m, v[1] / m, v[2] / m]
-            };
-            let spec = (n[0] * hv[0] + n[1] * hv[1] + n[2] * hv[2]).max(0.0).powf(sharp) * specular * li;
-            let light = ambient + diffuse * li * nl + cstr * focus * li;
-            // The surface: its colour lit like the water, or the sky it reflects (sampled along
-            // the surface normal; Convergence pulls the reflection towards the pixel itself).
-            let surface: [f32; 3] = match &sky {
-                Some(sk) => {
-                    let reach = (1.0 - convergence) * lw * 0.5;
-                    let (rx, ry) = (x as f64 + 0.5 + n[0] as f64 * reach, y as f64 + 0.5 + n[1] as f64 * reach);
-                    let (rx, ry) = (cx + (rx - cx) / sky_scaling, cy + (ry - cy) / sky_scaling);
-                    let (sc, _) = unpremul(sample_repeat(sk, rx, ry, sky_repeat));
-                    std::array::from_fn(|q| sc[q] * sky_int * 3.0 * surf[q])
-                }
-                None => std::array::from_fn(|q| surf[q] * (ambient + diffuse * li * nl)),
-            };
-            let cc: [f32; 3] = std::array::from_fn(|q| {
-                let base = c[q] * light * lc[q];
-                base * (1.0 - surf_op) + surface[q] * surf_op + spec * lc[q]
-            });
-            let a = (a + surf_op * (1.0 - a)).min(1.0);
-            *px = [cc[0] * a, cc[1] * a, cc[2] * a, a];
-        }
-    });
-    b
-}
-
-// ------------------------------------------------------------------ Wave World
-
-/// Wave World's simulated surface: an `nx` × `ny` grid of heights `u` and velocities `v`.
-#[derive(Clone, Debug)]
-pub struct Waves {
-    pub nx: usize,
-    pub ny: usize,
-    pub u: Vec<f32>,
-    pub v: Vec<f32>,
-}
-
-struct Producer {
-    ring: bool,
-    pos: [f32; 2],
-    len: f32,
-    width: f32,
-    angle: f32,
-    amp: f32,
-    freq: f32,
-    phase: f32,
-}
-
-impl Producer {
-    /// Weight of a grid point (layer-fraction coordinates, x in widths, y in widths).
-    fn weight(&self, x: f32, y: f32) -> f32 {
-        let (dx, dy) = (x - self.pos[0], y - self.pos[1]);
-        let (sa, ca) = self.angle.sin_cos();
-        let (u, v) = (dx * ca + dy * sa, -dx * sa + dy * ca);
-        let d = if self.ring {
-            let (a, bb) = ((self.len * 0.5).max(1e-3), (self.width * 0.5).max(1e-3));
-            ((u / a).powi(2) + (v / bb).powi(2)).sqrt()
-        } else {
-            let l = (self.len * 0.5).max(1e-3);
-            let wd = (self.width * 0.5).max(1e-3);
-            (u.abs() / l).max(v.abs() / wd)
-        };
-        (1.0 - d).clamp(0.0, 1.0).min(1.0)
-    }
-}
-
-static WAVE_CACHE: SimCache<Waves> = SimCache::new(4);
-
-/// What Wave World draws: the Height Map view of the simulated surface (grid heights and,
-/// with a ground layer, water depths per grid point), or the wireframe preview's lines.
-pub enum WavePlan {
-    Height { st: std::sync::Arc<Waves>, depth: Option<Vec<f32>> },
-    Wire(crate::sim::SpritePlan),
-}
-
-fn wave_world(ctx: &EffectCtx, b: Buf) -> Buf {
-    match wave_world_impl(ctx, &b, false) {
-        Ok(img) => Buf { img, ..b },
-        Err(WavePlan::Wire(plan)) => plan.finish(b),
-        Err(WavePlan::Height { .. }) => b,
-    }
-}
-
-/// Wave World's simulation state for the frame, as a [`WavePlan`] (its pixels are not read).
-pub fn wave_world_plan(ctx: &EffectCtx, b: &Buf) -> Option<WavePlan> {
-    wave_world_impl(ctx, b, true).err()
-}
-
-fn wave_world_impl(ctx: &EffectCtx, b: &Buf, plan_only: bool) -> Result<Image, WavePlan> {
-    let pr = ctx.params;
-    let [lw, lh] = ctx.layer_size;
-    let res = pr.f("simulation/gridResolution").clamp(1.0, 400.0) as usize;
-    let res = if pr.b("simulation/gridResDownsamples") { ((res as f64) * b.scale).round().max(1.0) as usize } else { res };
-    let nx = res.max(2) + 1;
-    let ny = ((res as f64 * lh / lw.max(1.0)).round() as usize).max(2) + 1;
-    let speed = pr.f("simulation/waveSpeed").max(0.0) as f32;
-    let damping = pr.f("simulation/damping").max(0.0) as f32;
-    let reflect = pr.e("simulation/reflectEdges");
-    let preroll = pr.f("simulation/preRoll").max(0.0);
-    let prods: Vec<Producer> = [1, 2]
-        .iter()
-        .map(|k| {
-            let pos = pr.v2(&format!("producer{k}/producer{k}Position"));
-            Producer {
-                ring: pr.e(&format!("producer{k}/producer{k}Type")) == 0,
-                pos: [(pos[0] / lw.max(1.0)) as f32, (pos[1] / lw.max(1.0)) as f32],
-                len: pr.f(&format!("producer{k}/producer{k}Length")) as f32,
-                width: pr.f(&format!("producer{k}/producer{k}Width")) as f32,
-                angle: (pr.f(&format!("producer{k}/producer{k}Angle")) as f32).to_radians(),
-                amp: pr.f(&format!("producer{k}/producer{k}Amplitude")) as f32,
-                freq: pr.f(&format!("producer{k}/producer{k}Frequency")) as f32,
-                phase: (pr.f(&format!("producer{k}/producer{k}Phase")) as f32).to_radians(),
-            }
-        })
-        .collect();
-    let sps = crate::sim::SPS as f32;
-    // Wave speed in layer widths per second → cells per second; sub-steps keep it stable.
-    let cps = speed * (nx - 1) as f32;
-    let sub = ((cps * 2.0 / sps).ceil() as usize).clamp(1, 64);
-    let dt = 1.0 / (sps * sub as f32);
-    let cell = 1.0 / (nx - 1) as f32;
-    let weights: Vec<Vec<f32>> = prods.iter().map(|p| (0..nx * ny).map(|i| p.weight((i % nx) as f32 * cell, (i / nx) as f32 * cell)).collect()).collect();
-    // Ground: the ground layer's first frame, its luminance an elevation (× Steepness). Where
-    // it rises above Height the grid is dry (a wall the waves reflect from); shallow water
-    // slows the waves by Wave Strength.
-    let ground = pr.get("ground/ground").and_then(Value::as_layer).and_then(|id| {
-        let host = ctx.env.host?;
-        host.layer_at(id, ctx.env.comp_time - ctx.time, true)
-    });
-    let steep = pr.get("ground/steepness").map(Value::as_f64).unwrap_or(0.25) as f32;
-    let level = pr.get("ground/height").map(Value::as_f64).unwrap_or(0.25) as f32;
-    let wave_strength = pr.f("ground/waveStrength").clamp(0.0, 1.0) as f32;
-    // Water depth per grid point (None without ground: deep everywhere).
-    let depth: Option<Vec<f32>> = ground.as_ref().map(|lp| {
-        let (gw, gh) = (lp.size[0].max(1.0), lp.size[1].max(1.0));
-        (0..nx * ny)
-            .map(|i| {
-                let (fx, fy) = ((i % nx) as f64 / (nx - 1) as f64, (i / nx) as f64 / (ny - 1) as f64);
-                let (c, a) = unpremul(lp.buf.img.sample_bilinear_clamped(fx * gw * lp.buf.scale + lp.buf.offset[0], fy * gh * lp.buf.scale + lp.buf.offset[1]));
-                level - steep * effectcraft_color::luminance(c[0], c[1], c[2]) * a
-            })
-            .collect()
-    });
-    let speed_k: Vec<f32> = match &depth {
-        Some(d) => d.iter().map(|&v| if v <= 0.0 { 0.0 } else { 1.0 - wave_strength * (1.0 - (v / level.max(1e-3)).clamp(0.0, 1.0).sqrt()) }).collect(),
-        None => vec![1.0; nx * ny],
-    };
-    let mut key =
-        params_key(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: if pr.b("simulation/gridResDownsamples") { b.scale } else { 1.0 } }, 4);
-    if let Some(d) = &depth {
-        key ^= d.iter().fold(0u64, |a, v| a.rotate_left(3) ^ v.to_bits() as u64);
-    }
-    let steps = crate::sim::steps_at(ctx.time + preroll);
-    let st = WAVE_CACHE.run(
-        key,
-        steps,
-        || Waves { nx, ny, u: vec![0.0; nx * ny], v: vec![0.0; nx * ny] },
-        |w, step| {
-            for k in 0..sub {
-                let t = (step as f32 + k as f32 / sub as f32) / sps - preroll as f32;
-                let c2 = cps * cps;
-                let mut acc = vec![0.0f32; nx * ny];
-                for y in 0..ny {
-                    for x in 0..nx {
-                        let i = y * nx + x;
-                        let g = |xx: usize, yy: usize| w.u[yy * nx + xx];
-                        let l = g(x.saturating_sub(1), y) + g((x + 1).min(nx - 1), y) + g(x, y.saturating_sub(1)) + g(x, (y + 1).min(ny - 1)) - 4.0 * w.u[i];
-                        acc[i] = c2 * speed_k[i] * speed_k[i] * l - damping * 4.0 * w.v[i];
-                    }
-                }
-                for i in 0..nx * ny {
-                    w.v[i] += acc[i] * dt;
-                    w.u[i] += w.v[i] * dt;
-                }
-                // Producers drive the surface.
-                for (p, wt) in prods.iter().zip(&weights) {
-                    if p.amp == 0.0 {
-                        continue;
-                    }
-                    let target = p.amp * (std::f32::consts::TAU * p.freq * t + p.phase).sin();
-                    for i in 0..nx * ny {
-                        if wt[i] > 0.0 {
-                            w.u[i] += (target - w.u[i]) * wt[i];
-                            w.v[i] *= 1.0 - wt[i];
-                        }
-                    }
-                }
-                // Dry ground holds the surface flat.
-                for i in 0..nx * ny {
-                    if speed_k[i] <= 0.0 {
-                        w.u[i] = 0.0;
-                        w.v[i] = 0.0;
-                    }
-                }
-                // Edges: reflective ones mirror; the others absorb in a thin sponge layer.
-                let refl = |side: u32| reflect == 5 || reflect == side;
-                let sponge = 4usize.min(nx / 4).max(1);
-                for y in 0..ny {
-                    for x in 0..nx {
-                        let i = y * nx + x;
-                        let mut f = 1.0f32;
-                        if !refl(1) && x < sponge {
-                            f = f.min(x as f32 / sponge as f32);
-                        }
-                        if !refl(3) && nx - 1 - x < sponge {
-                            f = f.min((nx - 1 - x) as f32 / sponge as f32);
-                        }
-                        if !refl(2) && y < sponge {
-                            f = f.min(y as f32 / sponge as f32);
-                        }
-                        if !refl(4) && ny - 1 - y < sponge {
-                            f = f.min((ny - 1 - y) as f32 / sponge as f32);
-                        }
-                        if f < 1.0 {
-                            let k = 0.85 + 0.15 * f;
-                            w.u[i] *= k;
-                            w.v[i] *= k;
-                        }
-                    }
-                }
-            }
-        },
-    );
-    let s = b.scale;
-    let (bw, bh) = (b.img.width, b.img.height);
-    let sample = |x: f64, y: f64| -> f32 {
-        let gx = (x / lw.max(1.0) * (st.nx - 1) as f64).clamp(0.0, (st.nx - 1) as f64);
-        let gy = (y / lw.max(1.0) * (st.nx - 1) as f64).clamp(0.0, (st.ny - 1) as f64);
-        let (x0, y0) = (gx.floor() as usize, gy.floor() as usize);
-        let (x1, y1) = ((x0 + 1).min(st.nx - 1), (y0 + 1).min(st.ny - 1));
-        let (tx, ty) = ((gx - x0 as f64) as f32, (gy - y0 as f64) as f32);
-        let g = |xx: usize, yy: usize| st.u[yy * st.nx + xx];
-        let a = g(x0, y0) + (g(x1, y0) - g(x0, y0)) * tx;
-        let c = g(x0, y1) + (g(x1, y1) - g(x0, y1)) * tx;
-        a + (c - a) * ty
-    };
-    if plan_only && pr.e("view") == 1 {
-        return Err(WavePlan::Height { st, depth });
-    }
-    if pr.e("view") == 1 {
-        let mut img = Image::new(bw, bh);
-        let bright = pr.f("heightMapControls/brightness") as f32;
-        let contrast = pr.f("heightMapControls/contrast") as f32;
-        let gamma = pr.f("heightMapControls/gamma").max(0.01) as f32;
-        let alpha = 1.0 - pr.f("heightMapControls/transparency") as f32;
-        let dry_transparent = pr.e("heightMapControls/renderDryAreasAs") == 1;
-        let dry_at = |x: f64, y: f64| -> bool {
-            let Some(d) = &depth else { return false };
-            let gx = (x / lw.max(1.0) * (st.nx - 1) as f64).round().clamp(0.0, (st.nx - 1) as f64) as usize;
-            let gy = (y / lw.max(1.0) * (st.nx - 1) as f64).round().clamp(0.0, (st.ny - 1) as f64) as usize;
-            d[gy * st.nx + gx] <= 0.0
-        };
-        img.rows_mut().for_each(|(y, row)| {
-            for (x, px) in row.iter_mut().enumerate() {
-                let lx = (x as f64 + 0.5 - b.offset[0]) / s;
-                let ly = (y as f64 + 0.5 - b.offset[1]) / s;
-                let v = (bright + contrast * sample(lx, ly)).clamp(0.0, 1.0).powf(1.0 / gamma);
-                let al = if dry_transparent && dry_at(lx, ly) { 0.0 } else { alpha };
-                *px = [v * al, v * al, v * al, al];
-            }
-        });
-        Ok(img)
-    } else {
-        // Wireframe preview: the grid turned by Horizontal Rotation about the vertical axis,
-        // tilted by Vertical Rotation, heights scaled by Vertical Scale.
-        let hr = pr.f("wireframeControls/horizontalRotation").to_radians();
-        let vr = pr.get("wireframeControls/verticalRotation").map(Value::as_f64).unwrap_or(53.0).to_radians();
-        let vs = pr.get("wireframeControls/verticalScale").map(Value::as_f64).unwrap_or(0.5);
-        let (sh, ch) = hr.sin_cos();
-        let (sv, cv) = vr.sin_cos();
-        let to = |x: usize, y: usize| -> [f32; 2] {
-            // Grid point relative to the layer centre (layer px), height in layer px.
-            let gx = x as f64 / (st.nx - 1) as f64 * lw - lw * 0.5;
-            let gy = y as f64 / (st.nx - 1) as f64 * lw - (st.ny - 1) as f64 / (st.nx - 1) as f64 * lw * 0.5;
-            let hgt = st.u[y * st.nx + x] as f64 * vs * lh * 0.5;
-            let (rx, ry) = (gx * ch - gy * sh, gx * sh + gy * ch);
-            let (px, py) = b.to_px([lw * 0.5 + rx, lh * 0.5 + ry * cv - hgt * sv]);
-            [px as f32, py as f32]
-        };
-        let mut lines = Vec::new();
-        for y in 0..st.ny {
-            for x in 0..st.nx {
-                let a = to(x, y);
-                if x + 1 < st.nx {
-                    let c = to(x + 1, y);
-                    lines.push(Sprite::new(a[0], a[1], 0.4, [0.4, 0.9, 0.4, 1.0], Shape::Line { dx: c[0] - a[0], dy: c[1] - a[1] }));
-                }
-                if y + 1 < st.ny {
-                    let c = to(x, y + 1);
-                    lines.push(Sprite::new(a[0], a[1], 0.4, [0.4, 0.9, 0.4, 1.0], Shape::Line { dx: c[0] - a[0], dy: c[1] - a[1] }));
-                }
-            }
-        }
-        let plan = crate::sim::SpritePlan { sprites: lines, tints: vec![], acc: Acc::Over, post: crate::sim::Post::OverBlack };
-        if plan_only {
-            return Err(WavePlan::Wire(plan));
-        }
-        Ok(plan.finish(Buf { img: Image::new(bw, bh), offset: b.offset, scale: b.scale }).img)
-    }
-}
-
-// ------------------------------------------------------------------ Foam
-
-#[derive(Clone, Debug)]
-struct FoamBubble {
-    p: [f32; 2],
-    v: [f32; 2],
-    age: f32,
-    size: f32,
-    /// Spin (radians) for Physical Orientation.
-    spin: f32,
-    id: u32,
-}
-
-#[derive(Clone, Debug, Default)]
-struct FoamState {
-    b: Vec<FoamBubble>,
-    carry: f32,
-    next: u32,
-}
-
-static FOAM_CACHE: SimCache<FoamState> = SimCache::new(4);
-
-/// Foam steps once per frame at 30 frames per second.
-const FOAM_FPS: f64 = 30.0;
-
-/// Foam's Bubble Texture options (the last uses Bubble Texture Layer).
-const FOAM_TEXTURES: [&str; 6] = ["Default Bubble", "Spit", "Bubblegum", "Dishwater", "Milky", "User Defined"];
-
-/// Age (in simulation steps) at which bubble `id` pops: its lifespan, shortened at random for
-/// frail bubbles (`frailty` 0 = every bubble reaches `lifespan`, 1 = uniformly early).
-fn foam_pop_age(id: u32, lifespan: f32, frailty: f32, seed: u32) -> f32 {
-    lifespan * (1.0 - frailty * (hs(id, 11, seed) * 0.5 + 0.5))
-}
-
-/// Foam: bubbles born in the producer rectangle grow to their size, drift with the wind,
-/// turbulence and the Flow Map (bubbles run downhill on its luminance), repel and stick to each
-/// other, wobble, and pop at the end of their (Strength-shortened) lifespan, pushing their
-/// neighbours away at Pop Velocity. Rendered bubbles use a built-in texture or the Bubble
-/// Texture Layer, oriented by Bubble Orientation, and reflect the Environment Map.
-fn foam(ctx: &EffectCtx, b: Buf) -> Buf {
-    foam_full_plan(ctx, &b).finish(b)
-}
-
-/// Foam's bubbles as sprites, `None` when it draws more than sprites (a User Defined bubble
-/// texture, an Environment Map reflection or the Draft + Flow Map view's flow map).
-pub(crate) fn foam_plan(ctx: &EffectCtx, b: &Buf) -> Option<crate::sim::SpritePlan> {
-    let plan = foam_full_plan(ctx, b);
-    (plan.user.is_none() && plan.env.is_none() && plan.flow.is_none()).then_some(plan.sprites)
-}
-
-/// A bubble disc filled by Foam's User Defined texture (buffer px; `rot` radians).
-#[derive(Clone, Copy, Debug)]
-pub struct FoamDisc {
-    pub x: f64,
-    pub y: f64,
-    pub r: f32,
-    pub rot: f32,
-    pub fade: f32,
-}
-
-/// Foam's Environment Map reflection: the map fitted to the buffer, Reflection Convergence and
-/// Strength, and the bubble discs reflecting it (`rot` and `fade` unused).
-pub struct FoamEnv {
-    pub img: Image,
-    pub conv: f64,
-    pub strength: f32,
-    pub discs: Vec<FoamDisc>,
-}
-
-/// What Foam draws this frame over a transparent frame of the layer's size: the bubble sprites,
-/// then the User Defined texture's discs, the Environment Map's reflections and (Draft + Flow
-/// Map) the flow map under it all, each `foam_disc`-composited in bubble order.
-pub struct FoamPlan {
-    pub sprites: crate::sim::SpritePlan,
-    pub user: Option<(crate::LayerPixels, Vec<FoamDisc>)>,
-    pub env: Option<FoamEnv>,
-    /// The flow map fitted to the buffer.
-    pub flow: Option<Image>,
-}
-
-impl FoamPlan {
-    pub fn finish(&self, b: Buf) -> Buf {
-        let mut out = splat(b.img.width, b.img.height, &self.sprites.sprites, self.sprites.acc);
-        // User Defined: the texture layer fills each bubble's disc.
-        if let Some((tex, discs)) = &self.user {
-            for d in discs {
-                let (rot, fade) = (d.rot, d.fade);
-                foam_disc(&mut out, d.x, d.y, d.r as f64, |u, v| {
-                    // u, v in −1..1 across the bubble, rotated into the texture.
-                    let (sr, cr) = rot.sin_cos();
-                    let (tu, tv) = (u as f32 * cr + v as f32 * sr, -u as f32 * sr + v as f32 * cr);
-                    let (x, y) = ((tu as f64 * 0.5 + 0.5) * tex.size[0], (tv as f64 * 0.5 + 0.5) * tex.size[1]);
-                    let px = tex.buf.img.sample_bilinear(x * tex.buf.scale + tex.buf.offset[0], y * tex.buf.scale + tex.buf.offset[1]);
-                    px.map(|c| c * fade)
-                });
-            }
-        }
-        // Environment Map: each bubble reflects the map along its sphere normal (Reflection
-        // Convergence pulls the reflection towards the bubble's own spot of the map).
-        if let Some(env) = &self.env {
-            let (conv, strength) = (env.conv, env.strength);
-            let (w, h) = (b.img.width as f64, b.img.height as f64);
-            for d in &env.discs {
-                let (bx, by) = (d.x, d.y);
-                foam_disc(&mut out, bx, by, d.r as f64, |u, v| {
-                    // Sphere normal; the reflection looks across the whole map, or (convergence 1)
-                    // just behind the bubble.
-                    let (ex, ey) =
-                        if conv >= 1.0 { (bx, by) } else { (bx * conv + (u * 0.5 + 0.5) * w * (1.0 - conv), by * conv + (v * 0.5 + 0.5) * h * (1.0 - conv)) };
-                    let e = env.img.sample_bilinear(ex, ey);
-                    let rim = ((u * u + v * v) as f32).min(1.0);
-                    let k = strength * (0.3 + 0.7 * rim);
-                    [e[0] * k, e[1] * k, e[2] * k, 0.0]
-                });
-            }
-        }
-        // Draft + Flow Map shows the flow map under the bubbles.
-        if let Some(fm) = &self.flow {
-            out.data.par_iter_mut().zip(fm.data.par_iter()).for_each(|(o, f)| {
-                let k = 1.0 - o[3];
-                for c in 0..4 {
-                    o[c] += f[c] * 0.5 * k;
-                }
-            });
-        }
-        Buf { img: out, ..b }
-    }
-}
-
-/// Foam's [`FoamPlan`] for layer geometry `b` (its size; its pixels are not read).
-pub fn foam_full_plan(ctx: &EffectCtx, b: &Buf) -> FoamPlan {
-    let pr = ctx.params;
-    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
-    let unit = lw * 0.01;
-    let prod = pr.v2("producer/producerPoint");
-    let (psx, psy) = (pr.f("producer/producerXSize") as f32 * lw, pr.f("producer/producerYSize") as f32 * lh);
-    let porient = (pr.f("producer/producerOrientation") as f32).to_radians();
-    let rate = pr.f("producer/productionRate").max(0.0) as f32;
-    let size = pr.f("bubbles/size").max(0.0) as f32;
-    let size_var = pr.f("bubbles/sizeVariance") as f32;
-    let lifespan = pr.f("bubbles/lifespan").max(1.0) as f32;
-    let growth = pr.f("bubbles/growthSpeed").max(0.0001) as f32;
-    // Strength: weaker bubbles tend to pop before their lifespan (at 20 or more every bubble
-    // lives the full lifespan); each bubble gets its own pop age.
-    let frailty = 1.0 - (pr.f("bubbles/strength") as f32 / 20.0).clamp(0.0, 1.0);
-    let init_speed = pr.f("physics/initialSpeed") as f32;
-    let init_dir = (pr.f("physics/initialDirection") as f32).to_radians();
-    let wind = pr.f("physics/windSpeed") as f32;
-    let wind_dir = (pr.f("physics/windDirection") as f32).to_radians();
-    let turb = pr.f("physics/turbulence") as f32;
-    let wobble = pr.f("physics/wobbleAmount").max(0.0) as f32;
-    let repulsion = pr.f("physics/repulsion") as f32;
-    let pop_velocity = pr.f("physics/popVelocity") as f32;
-    let viscosity = pr.f("physics/viscosity").clamp(0.0, 1.0) as f32;
-    let sticky = pr.f("physics/stickiness").clamp(0.0, 1.0) as f32;
-    let universe = pr.f("universeSize").max(0.01) as f32;
-    let seed = (pr.f("randomSeed") as u32).wrapping_mul(0x68e31da4) ^ ctx.seed;
-    let wvec = [wind_dir.sin() * wind * unit, -wind_dir.cos() * wind * unit];
-    // Flow Map: the map layer's first frame, its luminance a height field (Fits the layer or
-    // the whole universe).
-    let flow = pr.get("flowMap/flowMap").and_then(Value::as_layer).and_then(|id| {
-        let host = ctx.env.host?;
-        let me = pr.get(&crate::layer_source_id("flowMap/flowMap")).is_none_or(|v| v.as_enum() != 0);
-        host.layer_at(id, ctx.env.comp_time - ctx.time, me)
-    });
-    let steep = pr.f("flowMap/flowMapSteepness") as f32;
-    let fits_universe = pr.e("flowMap/flowMapFits") == 1;
-    let substeps = match pr.e("flowMap/simulationQuality") {
-        1 => 2,
-        2 => 4,
-        _ => 1,
-    };
-    let height = flow.as_ref().map(|lp| {
-        let img = &lp.buf.img;
-        let pl = Plane::from_image(img, |px| {
-            let (c, a) = unpremul(px);
-            effectcraft_color::luminance(c[0], c[1], c[2]) * a
-        });
-        (pl, lp.buf.scale, lp.buf.offset, lp.size)
-    });
-    let (ux0, uy0) = (-(universe - 1.0) * 0.5 * lw, -(universe - 1.0) * 0.5 * lh);
-    let (ux1, uy1) = (lw - ux0, lh - uy0);
-    // Height at a layer point (0..1).
-    let h_at = |x: f32, y: f32| -> f32 {
-        let Some((pl, s, off, size)) = &height else { return 0.0 };
-        let (fx, fy) = if fits_universe { ((x - ux0) / (ux1 - ux0), (y - uy0) / (uy1 - uy0)) } else { (x / lw, y / lh) };
-        pl.sample(fx as f64 * size[0] * s + off[0], fy as f64 * size[1] * s + off[1])
-    };
-    let mut key = params_key(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, 5);
-    if let Some((pl, ..)) = &height {
-        key ^= pl.data.iter().step_by(5).fold(0u64, |a, v| a.rotate_left(3) ^ v.to_bits() as u64);
-    }
-    let steps = if ctx.time <= 0.0 { 0 } else { (ctx.time * FOAM_FPS + 1e-6).floor() as u64 };
-    let rad = |q: &FoamBubble| q.size * unit * 3.0 * (q.age * growth).min(1.0);
-    let st = FOAM_CACHE.run(key, steps, FoamState::default, |st, step| {
-        let t = step as f32 / FOAM_FPS as f32;
-        // Births.
-        st.carry += rate;
-        let n = st.carry.floor() as u32;
-        st.carry -= n as f32;
-        for _ in 0..n {
-            if st.b.len() >= 3000 {
-                break;
-            }
-            let id = st.next;
-            st.next = st.next.wrapping_add(1);
-            let (ux, uy) = (hs(id, 1, seed) * 0.5 * psx, hs(id, 2, seed) * 0.5 * psy);
-            let (so, co) = porient.sin_cos();
-            let p = [prod[0] as f32 + ux * co - uy * so, prod[1] as f32 + ux * so + uy * co];
-            let v = [init_dir.sin() * init_speed * unit, -init_dir.cos() * init_speed * unit];
-            let sz = (size * (1.0 + size_var * hs(id, 3, seed))).max(0.01);
-            st.b.push(FoamBubble { p, v, age: 0.0, size: sz, spin: hs(id, 12, seed) * std::f32::consts::PI, id });
-        }
-        for _ in 0..substeps {
-            let k = 1.0 / substeps as f32;
-            // Forces: drift towards the wind, turbulence, viscosity, the flow map's slope.
-            for q in st.b.iter_mut() {
-                let n1 = value_noise(q.p[0] / (lw * 0.15), q.p[1] / (lw * 0.15), t * 0.5, seed) - 0.5;
-                let n2 = value_noise(q.p[0] / (lw * 0.15) + 19.0, q.p[1] / (lw * 0.15), t * 0.5, seed) - 0.5;
-                for c in 0..2 {
-                    q.v[c] += (wvec[c] - q.v[c]) * 0.1 * k;
-                    q.v[c] *= 1.0 - viscosity * 0.5 * k;
-                }
-                q.v[0] += n1 * turb * unit * k;
-                q.v[1] += n2 * turb * unit * k;
-                if height.is_some() && steep != 0.0 {
-                    let e = unit.max(1.0);
-                    let gx = (h_at(q.p[0] + e, q.p[1]) - h_at(q.p[0] - e, q.p[1])) / (2.0 * e);
-                    let gy = (h_at(q.p[0], q.p[1] + e) - h_at(q.p[0], q.p[1] - e)) / (2.0 * e);
-                    // Downhill: from light (high) to dark (low).
-                    q.v[0] -= gx * steep * lw * 0.5 * k;
-                    q.v[1] -= gy * steep * lw * 0.5 * k;
-                }
-                // Physical Orientation: bubbles roll with their sideways motion.
-                q.spin += q.v[0] / (rad(q).max(0.5)) * k;
-            }
-            // Repulsion between overlapping bubbles (grid hashed, deterministic order).
-            if repulsion > 0.0 && st.b.len() > 1 {
-                let maxr = st.b.iter().map(rad).fold(0.0f32, f32::max).max(1.0);
-                let cs = maxr * 2.0;
-                let mut grid: std::collections::HashMap<(i32, i32), Vec<usize>> = std::collections::HashMap::new();
-                for (i, q) in st.b.iter().enumerate() {
-                    grid.entry(((q.p[0] / cs).floor() as i32, (q.p[1] / cs).floor() as i32)).or_default().push(i);
-                }
-                let mut push = vec![[0.0f32; 2]; st.b.len()];
-                for (i, q) in st.b.iter().enumerate() {
-                    let (gx, gy) = ((q.p[0] / cs).floor() as i32, (q.p[1] / cs).floor() as i32);
-                    for dy in -1..=1 {
-                        for dx in -1..=1 {
-                            let Some(list) = grid.get(&(gx + dx, gy + dy)) else { continue };
-                            for &j in list {
-                                if j <= i {
-                                    continue;
-                                }
-                                let o = &st.b[j];
-                                let (ddx, ddy) = (o.p[0] - q.p[0], o.p[1] - q.p[1]);
-                                let d = (ddx * ddx + ddy * ddy).sqrt().max(1e-4);
-                                let overlap = rad(q) + rad(o) - d;
-                                if overlap > 0.0 {
-                                    let f = overlap * 0.5 * repulsion.min(4.0) * (1.0 - sticky * 0.5) / d * k;
-                                    push[i][0] -= ddx * f;
-                                    push[i][1] -= ddy * f;
-                                    push[j][0] += ddx * f;
-                                    push[j][1] += ddy * f;
-                                }
-                            }
-                        }
-                    }
-                }
-                for (q, d) in st.b.iter_mut().zip(&push) {
-                    q.p[0] += d[0].clamp(-maxr, maxr);
-                    q.p[1] += d[1].clamp(-maxr, maxr);
-                }
-            }
-            for q in st.b.iter_mut() {
-                q.p[0] += q.v[0] * k;
-                q.p[1] += q.v[1] * k;
-            }
-        }
-        for q in st.b.iter_mut() {
-            q.age += 1.0;
-        }
-        // Pops: bubbles past their pop age burst, pushing their neighbours away.
-        let popped: Vec<([f32; 2], f32)> = st.b.iter().filter(|q| q.age >= foam_pop_age(q.id, lifespan, frailty, seed)).map(|q| (q.p, rad(q))).collect();
-        if pop_velocity != 0.0 {
-            for (pp, pr_) in &popped {
-                let reach = (pr_ * 3.0).max(unit);
-                for q in st.b.iter_mut() {
-                    let (dx, dy) = (q.p[0] - pp[0], q.p[1] - pp[1]);
-                    let d = (dx * dx + dy * dy).sqrt();
-                    if d > 1e-4 && d < reach {
-                        let f = pop_velocity * unit * (1.0 - d / reach) / d;
-                        q.v[0] += dx * f;
-                        q.v[1] += dy * f;
-                    }
-                }
-            }
-        }
-        st.b.retain(|q| q.age < foam_pop_age(q.id, lifespan, frailty, seed) && q.p[0] > ux0 && q.p[0] < ux1 && q.p[1] > uy0 && q.p[1] < uy1);
-    });
-    let view = pr.e("view");
-    let zoom = pr.f("zoom").max(0.01) as f32;
-    let zoom_producer = pr.b("producer/zoomProducerPoint");
-    let texture = pr.e("rendering/bubbleTexture");
-    let orient = pr.e("rendering/bubbleOrientation");
-    let blend = pr.e("rendering/blendMode");
-    let s = b.scale as f32;
-    // Zoom centres on the layer, or on the producer with Zoom Producer Point.
-    let (cx, cy) = if zoom_producer { (prod[0] as f32, prod[1] as f32) } else { (lw * 0.5, lh * 0.5) };
-    let mut order: Vec<&FoamBubble> = st.b.iter().collect();
-    if blend == 2 {
-        // Solid New on Top: oldest first.
-        order.sort_by(|a, c| c.age.total_cmp(&a.age).then(a.id.cmp(&c.id)));
-    } else if blend == 1 {
-        order.sort_by(|a, c| a.age.total_cmp(&c.age).then(a.id.cmp(&c.id)));
-    }
-    // Where a bubble is drawn: buffer centre, radius, rotation (radians).
-    let place = |q: &FoamBubble| {
-        let wob = if wobble > 0.0 { 1.0 + wobble * 0.15 * ((q.age * 0.35) + hs(q.id, 13, seed) * 6.0).sin() } else { 1.0 };
-        let r = rad(q) * wob * zoom * s;
-        let (bx, by) = b.to_px([(cx + (q.p[0] - cx) * zoom) as f64, (cy + (q.p[1] - cy) * zoom) as f64]);
-        let rot = match orient {
-            1 => q.spin,
-            2 => q.v[1].atan2(q.v[0]),
-            _ => 0.0,
-        };
-        (bx, by, r, rot)
-    };
-    let user_tex = (view == 2 && texture == 5).then(|| ctx.layer_param("rendering/bubbleTextureLayer", true)).flatten();
-    let sprites: Vec<Sprite> = order
-        .iter()
-        .filter(|_| user_tex.is_none())
-        .map(|q| {
-            let (bx, by, r, rot) = place(q);
-            let fade = ((foam_pop_age(q.id, lifespan, frailty, seed) - q.age) / 5.0).clamp(0.0, 1.0);
-            // Draft and Draft + Flow Map show the wireframe-style bubbles.
-            let mut sp = if view != 2 {
-                Sprite::new(bx as f32, by as f32, r, [0.55, 0.75, 1.0, fade], Shape::Bubble)
-            } else {
-                let (c, shape) = match texture {
-                    1 => ([0.95, 0.95, 0.92], Shape::Faded),
-                    2 => ([1.0, 0.6, 0.8], Shape::Bubble),
-                    3 => ([0.8, 0.85, 0.75], Shape::Bubble),
-                    4 => ([0.97, 0.97, 0.95], Shape::Sphere),
-                    _ => ([1.0, 1.0, 1.0], Shape::Bubble),
-                };
-                Sprite::new(bx as f32, by as f32, r, [c[0], c[1], c[2], fade], shape)
-            };
-            sp.rot = rot;
-            sp
-        })
-        .collect();
-    let acc = if blend == 0 && view == 2 { Acc::Add } else { Acc::Over };
-    let disc = |q: &&FoamBubble| {
-        let (x, y, r, rot) = place(q);
-        let fade = ((foam_pop_age(q.id, lifespan, frailty, seed) - q.age) / 5.0).clamp(0.0, 1.0);
-        FoamDisc { x, y, r, rot, fade }
-    };
-    let user = user_tex.map(|tex| (tex, order.iter().map(disc).collect()));
-    let strength = pr.f("rendering/reflectionStrength").clamp(0.0, 1.0) as f32;
-    let env = if view == 2
-        && strength > 0.0
-        && let Some(env) = ctx.layer_param("rendering/environmentMap", true)
-    {
-        Some(FoamEnv {
-            img: crate::util::fit_layer(ctx, b, &env, true),
-            conv: pr.f("rendering/reflectionConvergence").clamp(0.0, 1.0),
-            strength,
-            discs: order.iter().map(disc).collect(),
-        })
-    } else {
-        None
-    };
-    let flow = if view == 1
-        && let Some(lp) = &flow
-    {
-        Some(crate::util::fit_layer(ctx, b, lp, true))
-    } else {
-        None
-    };
-    FoamPlan { sprites: crate::sim::SpritePlan { sprites, tints: vec![], acc, post: crate::sim::Post::Replace }, user, env, flow }
-}
-
-/// Add `f(u, v)` (premultiplied; u, v ∈ −1..1 across the disc) over the disc of radius `r` at
-/// (`x`, `y`) with anti-aliased edges ("over" for opaque texels, additive for alpha 0).
-fn foam_disc(out: &mut Image, x: f64, y: f64, r: f64, f: impl Fn(f64, f64) -> Px) {
-    if r <= 0.0 {
-        return;
-    }
-    let (x0, x1) = ((x - r - 1.0).floor().max(0.0) as i64, (x + r + 1.0).ceil().min(out.width as f64) as i64);
-    let (y0, y1) = ((y - r - 1.0).floor().max(0.0) as i64, (y + r + 1.0).ceil().min(out.height as f64) as i64);
-    for py in y0..y1 {
-        for px in x0..x1 {
-            let (u, v) = ((px as f64 + 0.5 - x) / r, (py as f64 + 0.5 - y) / r);
-            let d = (u * u + v * v).sqrt();
-            let cov = ((1.0 - d) * r + 0.5).clamp(0.0, 1.0) as f32;
-            if cov <= 0.0 {
-                continue;
-            }
-            let s = f(u.clamp(-1.0, 1.0), v.clamp(-1.0, 1.0)).map(|c| c * cov);
-            let o = out.get(px, py);
-            let k = 1.0 - s[3];
-            out.set(px as u32, py as u32, [s[0] + o[0] * k, s[1] + o[1] * k, s[2] + o[2] * k, (s[3] + o[3] * k).min(1.0)]);
-        }
-    }
-}
-
-// ------------------------------------------------------------------ specs
-
-fn producer_params(k: u32, amp: f64, pos: (f64, f64)) -> Vec<crate::ParamSpec> {
-    let ids: [&'static str; 8] = match k {
-        1 => [
-            "producer1/producer1Type",
-            "producer1/producer1Position",
-            "producer1/producer1Length",
-            "producer1/producer1Width",
-            "producer1/producer1Angle",
-            "producer1/producer1Amplitude",
-            "producer1/producer1Frequency",
-            "producer1/producer1Phase",
-        ],
-        _ => [
-            "producer2/producer2Type",
-            "producer2/producer2Position",
-            "producer2/producer2Length",
-            "producer2/producer2Width",
-            "producer2/producer2Angle",
-            "producer2/producer2Amplitude",
-            "producer2/producer2Frequency",
-            "producer2/producer2Phase",
-        ],
-    };
-    vec![
-        p(ids[0], "Type", Value::Enum(0), popup(&["Ring", "Line"])),
-        p(ids[1], "Position", pt(pos.0, pos.1), ParamUi::Point),
-        p(ids[2], "Height/Length", num(0.1), slider(0.0, 2.0, 0.0, 1.0, 3)),
-        p(ids[3], "Width", num(0.1), slider(0.0, 2.0, 0.0, 1.0, 3)),
-        p(ids[4], "Angle", num(0.0), ParamUi::Angle),
-        p(ids[5], "Amplitude", num(amp), slider(-5.0, 5.0, -1.0, 1.0, 3)),
-        p(ids[6], "Frequency", num(1.0), slider(0.0, 30.0, 0.0, 5.0, 3)),
-        p(ids[7], "Phase", num(0.0), ParamUi::Angle),
-    ]
-}
-
-fn card_dance_params() -> Vec<crate::ParamSpec> {
-    let mut v = vec![
-        p("rowsColumns", "Rows & Columns", Value::Enum(0), popup(&["Independent", "Columns Follows Rows"])),
-        p("rows", "Rows", num(10.0), slider(1.0, 1000.0, 1.0, 100.0, 0)),
-        p("columns", "Columns", num(10.0), slider(1.0, 1000.0, 1.0, 100.0, 0)),
-        p("backLayer", "Back Layer", Value::Layer(None), ParamUi::Layer),
-        p("gradientLayer1", "Gradient Layer 1", Value::Layer(None), ParamUi::Layer),
-        p("gradientLayer2", "Gradient Layer 2", Value::Layer(None), ParamUi::Layer),
-    ];
-    let names: [[&'static str; 4]; 8] = [
-        ["xPosition/xPosSource", "xPosition/xPosMultiplier", "xPosition/xPosOffset", "X Position"],
-        ["yPosition/yPosSource", "yPosition/yPosMultiplier", "yPosition/yPosOffset", "Y Position"],
-        ["zPosition/zPosSource", "zPosition/zPosMultiplier", "zPosition/zPosOffset", "Z Position"],
-        ["xRotation/xRotSource", "xRotation/xRotMultiplier", "xRotation/xRotOffset", "X Rotation"],
-        ["yRotation/yRotSource", "yRotation/yRotMultiplier", "yRotation/yRotOffset", "Y Rotation"],
-        ["zRotation/zRotSource", "zRotation/zRotMultiplier", "zRotation/zRotOffset", "Z Rotation"],
-        ["xScale/xScaleSource", "xScale/xScaleMultiplier", "xScale/xScaleOffset", "X Scale"],
-        ["yScale/yScaleSource", "yScale/yScaleMultiplier", "yScale/yScaleOffset", "Y Scale"],
-    ];
-    debug_assert_eq!(names.len(), CD_PROPS.len());
-    for (i, n) in names.iter().enumerate() {
-        let rot = (3..6).contains(&i);
-        let scale = i >= 6;
-        let (lo, hi) = if rot { (-3600.0, 3600.0) } else { (-100.0, 100.0) };
-        v.push(p(n[0], "Source", Value::Enum(0), popup(CD_SOURCES)));
-        v.push(p(n[1], "Multiplier", num(0.0), slider(lo, hi, if rot { -360.0 } else { -10.0 }, if rot { 360.0 } else { 10.0 }, 2)));
-        v.push(p(n[2], "Offset", num(if scale { 1.0 } else { 0.0 }), slider(lo, hi, if rot { -360.0 } else { -10.0 }, if rot { 360.0 } else { 10.0 }, 2)));
-    }
-    v.extend(crate::card3d::camera_params(2.0));
-    v.extend(crate::card3d::lighting_params(1.0, 0.25));
-    v.extend(crate::card3d::material_params(0.75));
-    v
-}
-
-pub fn specs() -> Vec<EffectSpec> {
-    vec![
-        spec(
-            "ec.sim.ccballaction",
-            "CC Ball Action",
-            vec![
-                p("scatter", "Scatter", num(0.0), slider(0.0, 2000.0, 0.0, 300.0, 1)),
-                p("rotationAxis", "Rotation Axis", Value::Enum(0), popup(&["X Axis", "Y Axis", "Z Axis", "XY Axis", "XZ Axis", "YZ Axis", "XYZ Axis"])),
-                p("rotation", "Rotation", num(0.0), ParamUi::Angle),
-                p("twistProperty", "Twist Property", Value::Enum(0), popup(&["X Axis", "Y Axis", "Radius", "Brightness"])),
-                p("twistAngle", "Twist Angle", num(0.0), ParamUi::Angle),
-                p("gridSpacing", "Grid Spacing", num(4.0), slider(1.0, 200.0, 1.0, 50.0, 0)),
-                p("ballSize", "Ball Size", num(40.0), slider(0.0, 400.0, 0.0, 200.0, 1)),
-                p("instabilityState", "Instability State", num(0.0), ParamUi::Angle),
-            ],
-            ball_action,
-        ),
-        spec(
-            "ec.sim.ccpixelpolly",
-            "CC Pixel Polly",
-            vec![
-                p("force", "Force", num(100.0), slider(-1000.0, 1000.0, -300.0, 300.0, 1)),
-                p("gravity", "Gravity", num(1.0), slider(-20.0, 20.0, -5.0, 5.0, 2)),
-                p("spinning", "Spinning", num(0.0), ParamUi::Angle),
-                p("forceCenter", "Force Center", pt(0.5, 0.5), ParamUi::Point),
-                p("directionRandomness", "Direction Randomness", num(10.0), pct()),
-                p("speedRandomness", "Speed Randomness", num(10.0), pct()),
-                p("gridSpacing", "Grid Spacing", num(10.0), slider(1.0, 500.0, 2.0, 100.0, 0)),
-                p("object", "Object", Value::Enum(0), popup(&["Polygon", "Textured Polygon", "Square", "Textured Square"])),
-                p("enableDepthSort", "Enable Depth Sort", Value::Bool(true), ParamUi::Checkbox),
-                p("startTime", "Start Time (sec)", num(0.0), slider(-1000.0, 1000.0, 0.0, 10.0, 2)),
-            ],
-            pixel_polly,
-        ),
-        spec(
-            "ec.sim.ccscatterize",
-            "CC Scatterize",
-            vec![
-                p("scatter", "Scatter", num(0.0), slider(0.0, 1000.0, 0.0, 200.0, 1)),
-                p("rightTwist", "Right Twist", num(0.0), ParamUi::Angle),
-                p("leftTwist", "Left Twist", num(0.0), ParamUi::Angle),
-                p("transferMode", "Transfer Mode", Value::Enum(0), popup(&["Composite", "Add"])),
-            ],
-            scatterize,
-        ),
-        spec("ec.sim.carddance", "Card Dance", card_dance_params(), card_dance),
-        spec(
-            "ec.sim.caustics",
-            "Caustics",
-            vec![
-                p("bottom/bottom", "Bottom", Value::Layer(None), ParamUi::Layer),
-                p("bottom/scaling", "Scaling", num(1.0), slider(0.01, 10.0, 0.1, 3.0, 3)),
-                p("bottom/repeatMode", "Repeat Mode", Value::Enum(2), popup(&["Once", "Tiled", "Reflected"])),
-                p("bottom/bottomSizeDiffers", "If Layer Size Differs", Value::Enum(1), popup(&["Center", "Stretch to Fit"])),
-                p("bottom/blur", "Blur", num(0.0), slider(0.0, 100.0, 0.0, 20.0, 1)),
-                p("water/waterSurface", "Water Surface", Value::Layer(None), ParamUi::Layer),
-                p("water/waveHeight", "Wave Height", num(0.2), slider(-1.0, 1.0, -1.0, 1.0, 3)),
-                p("water/smoothing", "Smoothing", num(5.0), slider(0.0, 100.0, 0.0, 50.0, 1)),
-                p("water/waterDepth", "Water Depth", num(0.1), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("water/refractiveIndex", "Refractive Index", num(1.2), slider(1.0, 3.0, 1.0, 2.0, 3)),
-                p("water/surfaceColor", "Surface Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("water/surfaceOpacity", "Surface Opacity", num(0.3), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("water/causticsStrength", "Caustics Strength", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("sky/sky", "Sky", Value::Layer(None), ParamUi::Layer),
-                p("sky/scaling", "Scaling", num(1.0), slider(0.01, 10.0, 0.1, 3.0, 3)),
-                p("sky/repeatMode", "Repeat Mode", Value::Enum(2), popup(&["Once", "Tiled", "Reflected"])),
-                p("sky/skySizeDiffers", "If Layer Size Differs", Value::Enum(1), popup(&["Center", "Stretch to Fit"])),
-                p("sky/intensity", "Intensity", num(0.3), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("sky/convergence", "Convergence", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("lighting/lightType", "Light Type", Value::Enum(0), popup(&crate::card3d::LIGHT_TYPES)),
-                p("lighting/lightIntensity", "Light Intensity", num(1.0), slider(0.0, 4.0, 0.0, 2.0, 2)),
-                p("lighting/lightColor", "Light Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("lighting/lightPosition", "Light Position", pt(0.0, 0.0), ParamUi::Point),
-                p("lighting/lightHeight", "Light Height", num(1.0), slider(0.0, 10.0, 0.0, 4.0, 2)),
-                p("lighting/ambientLight", "Ambient Light", num(0.35), slider(0.0, 2.0, 0.0, 1.0, 2)),
-                p("material/diffuse", "Diffuse Reflection", num(0.75), slider(0.0, 2.0, 0.0, 1.0, 2)),
-                p("material/specular", "Specular Reflection", num(0.2), slider(0.0, 2.0, 0.0, 1.0, 2)),
-                p("material/highlightSharpness", "Highlight Sharpness", num(15.0), slider(1.0, 100.0, 1.0, 100.0, 1)),
-            ],
-            caustics,
-        ),
-        spec(
-            "ec.sim.waveworld",
-            "Wave World",
-            {
-                let mut v = vec![
-                    p("view", "View", Value::Enum(0), popup(&["Wireframe Preview", "Height Map"])),
-                    p("wireframeControls/horizontalRotation", "Horizontal Rotation", num(0.0), ParamUi::Angle),
-                    p("wireframeControls/verticalRotation", "Vertical Rotation", num(53.0), slider(0.0, 90.0, 0.0, 90.0, 1)),
-                    p("wireframeControls/verticalScale", "Vertical Scale", num(0.5), slider(0.0, 10.0, 0.0, 2.0, 3)),
-                    p("heightMapControls/brightness", "Brightness", num(0.5), slider(-1.0, 2.0, 0.0, 1.0, 3)),
-                    p("heightMapControls/contrast", "Contrast", num(0.75), slider(0.0, 4.0, 0.0, 2.0, 3)),
-                    p("heightMapControls/gamma", "Gamma Adjustment", num(1.0), slider(0.01, 10.0, 0.2, 5.0, 3)),
-                    p("heightMapControls/renderDryAreasAs", "Render Dry Areas As", Value::Enum(0), popup(&["Solid", "Transparent"])),
-                    p("heightMapControls/transparency", "Transparency", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                    p("simulation/gridResolution", "Grid Resolution", num(60.0), slider(1.0, 400.0, 1.0, 200.0, 0)),
-                    p("simulation/gridResDownsamples", "Grid Res Downsamples", Value::Bool(false), ParamUi::Checkbox),
-                    p("simulation/waveSpeed", "Wave Speed", num(0.2), slider(0.0, 5.0, 0.0, 1.0, 3)),
-                    p("simulation/damping", "Damping", num(0.05), slider(0.0, 5.0, 0.0, 1.0, 3)),
-                    p("simulation/reflectEdges", "Reflect Edges", Value::Enum(0), popup(&["None", "Left", "Top", "Right", "Bottom", "All"])),
-                    p("simulation/preRoll", "Pre-roll (seconds)", num(0.0), slider(0.0, 30.0, 0.0, 10.0, 2)),
-                    p("ground/ground", "Ground", Value::Layer(None), ParamUi::Layer),
-                    p("ground/steepness", "Steepness", num(0.25), slider(0.0, 2.0, 0.0, 1.0, 3)),
-                    p("ground/height", "Height", num(0.25), slider(0.0, 2.0, 0.0, 1.0, 3)),
-                    p("ground/waveStrength", "Wave Strength", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                ];
-                v.extend(producer_params(1, 0.5, (0.5, 0.5)));
-                v.extend(producer_params(2, 0.0, (0.25, 0.25)));
-                v
-            },
-            wave_world,
-        ),
-        spec(
-            "ec.sim.shatter",
-            "Shatter",
-            vec![
-                p(
-                    "view",
-                    "View",
-                    Value::Enum(1),
-                    popup(&["Rendered", "Wireframe Front View", "Wireframe", "Wireframe Front View + Forces", "Wireframe + Forces"]),
-                ),
-                p("render", "Render", Value::Enum(0), popup(&["All", "Layer", "Pieces"])),
-                p("shape/pattern", "Pattern", Value::Enum(0), popup(SHATTER_PATTERNS)),
-                p("shape/repetitions", "Repetitions", num(10.0), slider(1.0, 500.0, 1.0, 100.0, 2)),
-                p("shape/direction", "Direction", num(0.0), ParamUi::Angle),
-                p("shape/origin", "Origin", pt(0.5, 0.5), ParamUi::Point),
-                p("shape/customShatterMap", "Custom Shatter Map", Value::Layer(None), ParamUi::Layer),
-                p("shape/whiteTilesFixed", "White Tiles Fixed", Value::Bool(false), ParamUi::Checkbox),
-                p("shape/extrusionDepth", "Extrusion Depth", num(0.05), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("force1/force1Position", "Position", pt(0.5, 0.5), ParamUi::Point),
-                p("force1/force1Depth", "Depth", num(0.1), slider(-1.0, 1.0, -1.0, 1.0, 3)),
-                p("force1/force1Radius", "Radius", num(0.4), slider(0.0, 4.0, 0.0, 2.0, 3)),
-                p("force1/force1Strength", "Strength", num(5.0), slider(-20.0, 20.0, -10.0, 10.0, 2)),
-                p("force2/force2Position", "Position", pt(0.25, 0.25), ParamUi::Point),
-                p("force2/force2Depth", "Depth", num(0.1), slider(-1.0, 1.0, -1.0, 1.0, 3)),
-                p("force2/force2Radius", "Radius", num(0.0), slider(0.0, 4.0, 0.0, 2.0, 3)),
-                p("force2/force2Strength", "Strength", num(5.0), slider(-20.0, 20.0, -10.0, 10.0, 2)),
-                p("physics/rotationSpeed", "Rotation Speed", num(0.2), slider(0.0, 5.0, 0.0, 1.0, 3)),
-                p("physics/tumbleAxis", "Tumble Axis", Value::Enum(0), popup(&["Free", "None", "X", "Y", "Z", "XY", "XZ", "YZ"])),
-                p("physics/randomness", "Randomness", num(0.1), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("physics/viscosity", "Viscosity", num(0.1), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("physics/massVariance", "Mass Variance", num(30.0), pct()),
-                p("physics/gravity", "Gravity", num(3.0), slider(0.0, 100.0, 0.0, 10.0, 2)),
-                p("physics/gravityDirection", "Gravity Direction", num(180.0), ParamUi::Angle),
-                p("physics/gravityInclination", "Gravity Inclination", num(0.0), slider(-90.0, 90.0, -90.0, 90.0, 1)),
-                p("gradient/shatterThreshold", "Shatter Threshold", num(0.0), slider(0.0, 100.0, 0.0, 100.0, 1)),
-                p("gradient/gradientLayer", "Gradient Layer", Value::Layer(None), ParamUi::Layer),
-                p("gradient/invertGradient", "Invert Gradient", Value::Bool(false), ParamUi::Checkbox),
-                p("textures/color", "Color", col(1.0, 1.0, 1.0), ParamUi::Color),
-                p("textures/opacity", "Opacity", num(1.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("textures/frontMode", "Front Mode", Value::Enum(1), popup(&SHATTER_TEXTURE_MODES)),
-                p("textures/sideMode", "Side Mode", Value::Enum(0), popup(&SHATTER_TEXTURE_MODES)),
-                p("textures/backMode", "Back Mode", Value::Enum(1), popup(&SHATTER_TEXTURE_MODES)),
-                p("textures/frontLayer", "Front Layer", Value::Layer(None), ParamUi::Layer),
-                p("textures/sideLayer", "Side Layer", Value::Layer(None), ParamUi::Layer),
-                p("textures/backLayer", "Back Layer", Value::Layer(None), ParamUi::Layer),
-            ]
-            .into_iter()
-            .chain(crate::card3d::camera_params(4.0))
-            .chain(crate::card3d::lighting_params(1.0, 0.25))
-            .chain(crate::card3d::material_params(0.75))
-            .chain([p("randomSeed", "Random Seed", num(0.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0))])
-            .collect(),
-            shatter,
-        ),
-        spec(
-            "ec.sim.foam",
-            "Foam",
-            vec![
-                p("view", "View", Value::Enum(0), popup(&["Draft", "Draft + Flow Map", "Rendered"])),
-                p("producer/producerPoint", "Producer Point", pt(0.5, 0.5), ParamUi::Point),
-                p("producer/producerXSize", "Producer X Size", num(0.05), slider(0.0, 2.0, 0.0, 1.0, 3)),
-                p("producer/producerYSize", "Producer Y Size", num(0.05), slider(0.0, 2.0, 0.0, 1.0, 3)),
-                p("producer/producerOrientation", "Producer Orientation", num(0.0), ParamUi::Angle),
-                p("producer/zoomProducerPoint", "Zoom Producer Point", Value::Bool(false), ParamUi::Checkbox),
-                p("producer/productionRate", "Production Rate", num(1.0), slider(0.0, 50.0, 0.0, 10.0, 3)),
-                p("bubbles/size", "Size", num(0.5), slider(0.0, 10.0, 0.0, 2.0, 3)),
-                p("bubbles/sizeVariance", "Size Variance", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("bubbles/lifespan", "Lifespan", num(300.0), slider(1.0, 30_000.0, 1.0, 1000.0, 1)),
-                p("bubbles/growthSpeed", "Bubble Growth Speed", num(0.1), slider(0.0001, 10.0, 0.0001, 1.0, 3)),
-                p("bubbles/strength", "Strength", num(10.0), slider(0.0, 100.0, 0.0, 20.0, 2)),
-                p("physics/initialSpeed", "Initial Speed", num(0.0), slider(-100.0, 100.0, -10.0, 10.0, 3)),
-                p("physics/initialDirection", "Initial Direction", num(0.0), ParamUi::Angle),
-                p("physics/windSpeed", "Wind Speed", num(0.5), slider(-100.0, 100.0, -10.0, 10.0, 3)),
-                p("physics/windDirection", "Wind Direction", num(90.0), ParamUi::Angle),
-                p("physics/turbulence", "Turbulence", num(0.5), slider(0.0, 10.0, 0.0, 2.0, 3)),
-                p("physics/wobbleAmount", "Wobble Amount", num(0.05), slider(0.0, 10.0, 0.0, 2.0, 3)),
-                p("physics/repulsion", "Repulsion", num(1.0), slider(0.0, 10.0, 0.0, 2.0, 3)),
-                p("physics/popVelocity", "Pop Velocity", num(1.0), slider(-100.0, 100.0, -10.0, 10.0, 3)),
-                p("physics/viscosity", "Viscosity", num(0.1), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("physics/stickiness", "Stickiness", num(0.75), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("zoom", "Zoom", num(1.0), slider(0.01, 50.0, 0.1, 5.0, 3)),
-                p("universeSize", "Universe Size", num(1.0), slider(0.01, 10.0, 0.5, 3.0, 3)),
-                p("rendering/blendMode", "Blend Mode", Value::Enum(0), popup(&["Transparent", "Solid Old on Top", "Solid New on Top"])),
-                p("rendering/bubbleTexture", "Bubble Texture", Value::Enum(0), popup(&FOAM_TEXTURES)),
-                p("rendering/bubbleTextureLayer", "Bubble Texture Layer", Value::Layer(None), ParamUi::Layer),
-                p("rendering/bubbleOrientation", "Bubble Orientation", Value::Enum(0), popup(&["Fixed", "Physical Orientation", "Bubble Velocity"])),
-                p("rendering/environmentMap", "Environment Map", Value::Layer(None), ParamUi::Layer),
-                p("rendering/reflectionStrength", "Reflection Strength", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("rendering/reflectionConvergence", "Reflection Convergence", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
-                p("flowMap/flowMap", "Flow Map", Value::Layer(None), ParamUi::Layer),
-                p("flowMap/flowMapSteepness", "Flow Map Steepness", num(0.05), slider(-100.0, 100.0, -1.0, 1.0, 3)),
-                p("flowMap/flowMapFits", "Flow Map Fits", Value::Enum(0), popup(&["Background", "Universe"])),
-                p("flowMap/simulationQuality", "Simulation Quality", Value::Enum(0), popup(&["Normal", "High", "Intense"])),
-                p("randomSeed", "Random Seed", num(1.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
-            ],
-            foam,
-        ),
-    ]
-}
+mod foam;
+mod pieces;
+mod pixels;
+mod registry;
+mod shatter;
+mod surfaces;
+
+pub(crate) use foam::foam_plan;
+#[cfg(test)]
+use foam::foam_pop_age;
+pub use foam::{FoamDisc, FoamEnv, FoamPlan, foam_full_plan};
+#[cfg(test)]
+use pieces::Cam;
+#[cfg(test)]
+pub(crate) use pieces::draw_pieces;
+pub use pieces::{Piece, PiecePlan, PieceTex, piece_plan};
+pub(crate) use pieces::{rot_axis, sort_far_first};
+pub use pixels::{PixelPlan, pixel_plan};
+pub use registry::specs;
+#[cfg(test)]
+use shatter::SHATTER_PATTERNS;
+pub use surfaces::{CausticsSetup, WavePlan, Waves, caustics_setup, wave_world_plan};
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::{EffectEnv, run_fx};
-
-    fn ramp(w: u32, hh: u32) -> Image {
-        let mut img = Image::new(w, hh);
-        for y in 0..hh {
-            for x in 0..w {
-                img.set(x, y, [x as f32 / w as f32, y as f32 / hh as f32, 0.4, 1.0]);
-            }
-        }
-        img
-    }
-
-    fn run(id: &str, vals: &[(&str, Value)], img: Image, t: f64) -> Image {
-        run_fx(id, vals, img, t, EffectEnv::default()).img
-    }
-
-    fn max_diff(a: &Image, b: &Image) -> f32 {
-        a.data.iter().zip(&b.data).map(|(p, q)| (0..4).map(|k| (p[k] - q[k]).abs()).fold(0.0, f32::max)).fold(0.0, f32::max)
-    }
-
-    fn sum_diff(a: &Image, b: &Image) -> f32 {
-        a.data.iter().zip(&b.data).map(|(p, q)| (0..4).map(|k| (p[k] - q[k]).abs()).sum::<f32>()).sum()
-    }
-
-    #[test]
-    fn piece_at_rest_is_identity() {
-        let src = ramp(16, 16);
-        let cam = Cam { c: [8.0, 8.0], d: 64.0 };
-        let id = rot_axis([1.0, 0.0, 0.0], 0.0);
-        let pc = Piece::new(&[[0.0, 0.0], [16.0, 0.0], [16.0, 16.0], [0.0, 16.0]], [8.0, 8.0], &id, [8.0, 8.0, 0.0], cam).unwrap();
-        let mut out = Image::new(16, 16);
-        draw_pieces(&mut out, &[pc], &src, None);
-        assert!(max_diff(&out, &src) < 1e-4);
-    }
-
-    #[test]
-    fn ball_action_draws_balls() {
-        let v = [("ballSize", num(80.0))];
-        let a = run("ec.sim.ccballaction", &v, ramp(32, 32), 0.0);
-        assert_eq!(a, run("ec.sim.ccballaction", &v, ramp(32, 32), 0.0));
-        assert!(a.data.iter().any(|p| p[3] > 0.9) && a.data.iter().any(|p| p[3] == 0.0), "balls with gaps");
-        let none = run("ec.sim.ccballaction", &[("ballSize", num(0.0))], ramp(32, 32), 0.0);
-        assert!(none.data.iter().all(|p| p[3] == 0.0));
-        let sc = run("ec.sim.ccballaction", &[("ballSize", num(80.0)), ("scatter", num(20.0))], ramp(32, 32), 0.0);
-        assert!(sum_diff(&a, &sc) > 1.0);
-    }
-
-    #[test]
-    fn pixel_polly_breaks_after_start() {
-        let v = [("forceCenter", pt(16.0, 16.0)), ("gridSpacing", num(4.0))];
-        let before = run("ec.sim.ccpixelpolly", &v, ramp(32, 32), 0.0);
-        assert_eq!(before, ramp(32, 32), "intact before the start time");
-        let a = run("ec.sim.ccpixelpolly", &v, ramp(32, 32), 0.5);
-        assert_eq!(a, run("ec.sim.ccpixelpolly", &v, ramp(32, 32), 0.5));
-        assert!(sum_diff(&a, &ramp(32, 32)) > 10.0);
-        let tex = run("ec.sim.ccpixelpolly", &[("forceCenter", pt(16.0, 16.0)), ("gridSpacing", num(4.0)), ("object", Value::Enum(3))], ramp(32, 32), 0.5);
-        assert!(sum_diff(&a, &tex) > 0.1);
-    }
-
-    #[test]
-    fn scatterize_identity_and_scatter() {
-        assert_eq!(run("ec.sim.ccscatterize", &[], ramp(24, 24), 0.0), ramp(24, 24));
-        let a = run("ec.sim.ccscatterize", &[("scatter", num(5.0))], ramp(24, 24), 0.0);
-        assert_eq!(a, run("ec.sim.ccscatterize", &[("scatter", num(5.0))], ramp(24, 24), 0.0));
-        assert!(sum_diff(&a, &ramp(24, 24)) > 1.0);
-        let tw = run("ec.sim.ccscatterize", &[("leftTwist", num(80.0)), ("rightTwist", num(80.0))], ramp(24, 24), 0.0);
-        assert!(sum_diff(&tw, &ramp(24, 24)) > 1.0);
-    }
-
-    #[test]
-    fn card_dance_identity_and_rotation() {
-        let src = ramp(30, 20);
-        let a = run("ec.sim.carddance", &[], src.clone(), 0.0);
-        assert!(max_diff(&a, &src) < 0.02, "flat cards reproduce the layer: {}", max_diff(&a, &src));
-        let r = run("ec.sim.carddance", &[("yRotation/yRotSource", Value::Enum(1)), ("yRotation/yRotMultiplier", num(90.0))], src.clone(), 0.0);
-        assert_eq!(r, run("ec.sim.carddance", &[("yRotation/yRotSource", Value::Enum(1)), ("yRotation/yRotMultiplier", num(90.0))], src.clone(), 0.0));
-        assert!(sum_diff(&r, &src) > 5.0);
-        let z = run("ec.sim.carddance", &[("zPosition/zPosOffset", num(-1.0))], src.clone(), 0.0);
-        assert!(sum_diff(&z, &src) > 5.0, "cards pulled towards the camera grow");
-    }
-
-    #[test]
-    fn shatter_at_rest_then_breaks() {
-        let v = [("view", Value::Enum(0)), ("force1/force1Position", pt(16.0, 16.0)), ("shape/origin", pt(16.0, 16.0))];
-        let src = ramp(32, 32);
-        let t0 = run("ec.sim.shatter", &v, src.clone(), 0.0);
-        assert!(max_diff(&t0, &src) < 0.03, "{}", max_diff(&t0, &src));
-        let t1 = run("ec.sim.shatter", &v, src.clone(), 0.5);
-        assert_eq!(t1, run("ec.sim.shatter", &v, src.clone(), 0.5));
-        assert!(sum_diff(&t1, &src) > 10.0);
-        for pat in 0..SHATTER_PATTERNS.len() as u32 {
-            let vv =
-                [("view", Value::Enum(0)), ("shape/pattern", Value::Enum(pat)), ("force1/force1Position", pt(16.0, 16.0)), ("shape/origin", pt(16.0, 16.0))];
-            let r = run("ec.sim.shatter", &vv, src.clone(), 0.0);
-            assert!(max_diff(&r, &src) < 0.05, "pattern {pat} tiles the layer: {}", max_diff(&r, &src));
-        }
-        let wire = run("ec.sim.shatter", &[("shape/repetitions", num(3.0))], src.clone(), 0.0);
-        assert!(wire.data.iter().any(|p| p[3] > 0.5) && wire.data.iter().any(|p| p[3] == 0.0));
-        let layer_only =
-            run("ec.sim.shatter", &[("view", Value::Enum(0)), ("render", Value::Enum(1)), ("force1/force1Position", pt(16.0, 16.0))], src.clone(), 0.5);
-        assert!(layer_only.get(16, 16)[3] == 0.0, "broken centre removed");
-    }
-
-    #[test]
-    fn caustics_flat_water() {
-        let src = ramp(24, 24);
-        let a = run(
-            "ec.sim.caustics",
-            &[
-                ("water/surfaceOpacity", num(0.0)),
-                ("lighting/ambientLight", num(0.0)),
-                ("material/diffuse", num(1.0)),
-                ("lighting/lightHeight", num(1000.0)),
-                ("material/specular", num(0.0)),
-            ],
-            src.clone(),
-            0.0,
-        );
-        assert!(max_diff(&a, &src) < 0.01, "flat water, light overhead = bottom: {}", max_diff(&a, &src));
-        let b = run("ec.sim.caustics", &[], src.clone(), 0.0);
-        assert_eq!(b, run("ec.sim.caustics", &[], src.clone(), 0.0));
-        assert!(sum_diff(&b, &src) > 0.1);
-    }
-
-    #[test]
-    fn caustics_sky_and_light_types() {
-        let src = Image::filled(32, 32, [0.5, 0.5, 0.5, 1.0]);
-        let env = EffectEnv { host: Some(&FoamHost), ..Default::default() };
-        let run_h = |vals: &[(&str, Value)]| run_fx("ec.sim.caustics", vals, src.clone(), 0.0, env).img;
-        // A mirror-like surface shows the (green) sky.
-        let mirror = [("water/surfaceOpacity", num(1.0)), ("sky/sky", Value::Layer(Some(2))), ("sky/intensity", num(1.0))];
-        let p = run_h(&mirror).get(16, 16);
-        assert!(p[1] > p[0] + 0.3 && p[1] > p[2] + 0.3, "{p:?}");
-        // Point Source lights pixels by their own direction to the light: the image is no
-        // longer uniform; Distant Source lights the flat water evenly.
-        let lit = |t: u32| {
-            run_h(&[
-                ("lighting/lightType", Value::Enum(t)),
-                ("lighting/lightPosition", pt(0.0, 0.0)),
-                ("lighting/lightHeight", num(0.2)),
-                ("water/surfaceOpacity", num(0.0)),
-            ])
-        };
-        let (distant, point) = (lit(0), lit(1));
-        assert!((distant.get(2, 2)[0] - distant.get(30, 30)[0]).abs() < 1e-5);
-        assert!(point.get(2, 2)[0] > point.get(30, 30)[0] + 0.02, "{:?} {:?}", point.get(2, 2), point.get(30, 30));
-        // First Comp Light without a comp light: ambient only.
-        let none = run_h(&[("lighting/lightType", Value::Enum(2)), ("water/surfaceOpacity", num(0.0))]);
-        assert!(none.get(16, 16)[0] < distant.get(16, 16)[0]);
-    }
-
-    #[test]
-    fn wave_world_wireframe_controls_ground_and_dry_areas() {
-        let base = [("producer1/producer1Position", pt(8.0, 16.0)), ("simulation/gridResolution", num(24.0))];
-        let wire = |extra: &[(&str, Value)]| run("ec.sim.waveworld", &[base.as_slice(), extra].concat(), Image::new(32, 32), 0.5);
-        assert_ne!(wire(&[]), wire(&[("wireframeControls/horizontalRotation", num(40.0))]));
-        assert_ne!(wire(&[]), wire(&[("wireframeControls/verticalScale", num(3.0))]));
-        // Ground (left dark, right light): the light side rises above the water and is dry.
-        let env = EffectEnv { host: Some(&FoamHost), ..Default::default() };
-        let hm = |extra: &[(&str, Value)]| {
-            let mut v: Vec<(&str, Value)> = base.to_vec();
-            v.extend([("view", Value::Enum(1)), ("ground/ground", Value::Layer(Some(1))), ("ground/steepness", num(0.5)), ("ground/height", num(0.25))]);
-            v.extend_from_slice(extra);
-            run_fx("ec.sim.waveworld", &v, Image::new(32, 32), 1.0, env).img
-        };
-        let solid = hm(&[]);
-        let clear = hm(&[("heightMapControls/renderDryAreasAs", Value::Enum(1))]);
-        assert!(solid.get(30, 16)[3] > 0.99 && clear.get(30, 16)[3] == 0.0);
-        assert!(clear.get(4, 16)[3] > 0.99, "wet side stays");
-        // Dry ground stays flat: mid grey (brightness 0.5) there.
-        assert!((solid.get(30, 16)[0] - 0.5).abs() < 1e-4);
-        // Wave Strength slows waves over shallow water: the surface differs.
-        assert_ne!(hm(&[]), hm(&[("ground/waveStrength", num(1.0))]));
-    }
-
-    #[test]
-    fn wave_world_seek_and_waves() {
-        let v = vec![("view", Value::Enum(1)), ("producer1/producer1Position", pt(16.0, 16.0)), ("simulation/gridResolution", num(24.0))];
-        let _ = run("ec.sim.waveworld", &v, Image::new(32, 32), 0.5);
-        let a = run("ec.sim.waveworld", &v, Image::new(32, 32), 1.0);
-        let mut v2 = v.clone();
-        v2.push(("heightMapControls/transparency", num(0.0)));
-        assert_eq!(a, run("ec.sim.waveworld", &v2, Image::new(32, 32), 1.0));
-        // Waves spread: some pixels differ from the flat-water grey.
-        assert!(a.data.iter().any(|p| (p[0] - 0.5).abs() > 0.05), "waves");
-        let flat = run("ec.sim.waveworld", &[("view", Value::Enum(1)), ("producer1/producer1Amplitude", num(0.0))], Image::new(32, 32), 1.0);
-        assert!(flat.data.iter().all(|p| (p[0] - 0.5).abs() < 1e-5));
-        let wire =
-            run("ec.sim.waveworld", &[("producer1/producer1Position", pt(16.0, 16.0)), ("simulation/gridResolution", num(10.0))], Image::new(32, 32), 0.3);
-        assert!(wire.data.iter().any(|p| p[1] > 0.3));
-    }
-
-    #[test]
-    fn wave_world_steps_match_direct() {
-        // Fresh caches: resumed simulation equals simulation from scratch.
-        let v = vec![
-            ("view", Value::Enum(1)),
-            ("producer1/producer1Position", pt(16.0, 16.0)),
-            ("simulation/gridResolution", num(20.0)),
-            ("simulation/damping", num(0.07)),
-        ];
-        let a = run("ec.sim.waveworld", &v, Image::new(32, 32), 1.3);
-        let mut v2 = v.clone();
-        v2.push(("simulation/damping", num(0.07000001)));
-        // Different key: computed from scratch at 1.3 directly vs via 0.4 (both fresh keys).
-        let _ = run("ec.sim.waveworld", &v2, Image::new(32, 32), 0.4);
-        let b = run("ec.sim.waveworld", &v2, Image::new(32, 32), 1.3);
-        assert!(max_diff(&a, &b) < 1e-3, "{}", max_diff(&a, &b));
-    }
-
-    #[test]
-    fn foam_bubbles_drift_and_seek() {
-        let v = vec![("producer/producerPoint", pt(16.0, 16.0)), ("view", Value::Enum(2)), ("producer/productionRate", num(2.0))];
-        let none = run("ec.sim.foam", &v, Image::new(32, 32), 0.0);
-        assert!(none.data.iter().all(|p| p[3] == 0.0));
-        let _ = run("ec.sim.foam", &v, Image::new(32, 32), 0.6);
-        let a = run("ec.sim.foam", &v, Image::new(32, 32), 1.2);
-        let mut v2 = v.clone();
-        v2.push(("randomSeed", num(1.0)));
-        assert_eq!(a, run("ec.sim.foam", &v2, Image::new(32, 32), 1.2));
-        assert!(a.data.iter().any(|p| p[3] > 0.05), "bubbles");
-        let draft = run("ec.sim.foam", &[("producer/producerPoint", pt(16.0, 16.0)), ("producer/productionRate", num(2.0))], Image::new(32, 32), 1.0);
-        assert!(draft.data.iter().any(|p| p[3] > 0.05));
-    }
-
-    #[test]
-    fn foam_strength_controls_early_popping() {
-        // Strong bubbles all live their full lifespan; weak ones pop at random earlier.
-        assert_eq!(foam_pop_age(7, 300.0, 0.0, 1), 300.0);
-        let early = (0..200).filter(|&id| foam_pop_age(id, 300.0, 1.0, 1) < 150.0).count();
-        assert!(early > 60 && early < 140, "{early}");
-        let count = |strength: f64| {
-            let v = vec![
-                ("producer/producerPoint", pt(16.0, 16.0)),
-                ("producer/productionRate", num(3.0)),
-                ("bubbles/lifespan", num(40.0)),
-                ("bubbles/strength", num(strength)),
-                ("physics/windSpeed", num(0.0)),
-            ];
-            run("ec.sim.foam", &v, Image::new(32, 32), 1.5).data.iter().map(|p| p[3]).sum::<f32>()
-        };
-        assert!(count(0.0) < count(20.0) * 0.9, "{} vs {}", count(0.0), count(20.0));
-    }
-
-    /// A host with a comp camera (identity, or tilted) and a first comp light.
-    struct Scene {
-        camera: Option<[[f64; 4]; 3]>,
-        light: Option<crate::CompLight>,
-        layer: Option<Image>,
-    }
-    impl crate::EffectHost for Scene {
-        fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
-            let img = self.layer.clone()?;
-            let size = [img.width as f64, img.height as f64];
-            Some(crate::LayerPixels { buf: Buf { img, offset: [0.0; 2], scale: 1.0 }, size })
-        }
-        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
-            None
-        }
-        fn comp_scene(&self) -> Option<crate::CompScene> {
-            Some(crate::CompScene { camera: self.camera, camera_layer: true, light: self.light })
-        }
-    }
-
-    fn run_env(id: &str, vals: &[(&str, Value)], img: Image, t: f64, host: &Scene) -> Image {
-        run_fx(id, vals, img, t, EffectEnv { host: Some(host), ..Default::default() }).img
-    }
-
-    #[test]
-    fn card_dance_camera_systems() {
-        let src = ramp(40, 30);
-        // Camera Position: rotating the camera changes the view; zero rotation is the layer.
-        let r = run("ec.sim.carddance", &[("cameraPosition/yRotation", num(30.0))], src.clone(), 0.0);
-        assert!(sum_diff(&r, &src) > 10.0);
-        let order = run("ec.sim.carddance", &[("cameraPosition/yRotation", num(30.0)), ("cameraPosition/xRotation", num(30.0))], src.clone(), 0.0);
-        let order2 = run(
-            "ec.sim.carddance",
-            &[("cameraPosition/yRotation", num(30.0)), ("cameraPosition/xRotation", num(30.0)), ("cameraPosition/transformOrder", Value::Enum(5))],
-            src.clone(),
-            0.0,
-        );
-        assert!(sum_diff(&order, &order2) > 1.0, "Transform Order matters");
-        // X, Y Position moves the view: the layer shifts by the offset.
-        let moved = run("ec.sim.carddance", &[("cameraPosition/xyPosition", pt(30.0, 15.0))], src.clone(), 0.0);
-        assert!((moved.get(25, 10)[0] - src.get(15, 10)[0]).abs() < 0.03, "{:?} {:?}", moved.get(25, 10), src.get(15, 10));
-        // Corner Pins: the layer's corners land on the pins.
-        let pins = [
-            ("cameraSystem", Value::Enum(1)),
-            ("cornerPins/upperLeftCorner", pt(10.0, 5.0)),
-            ("cornerPins/upperRightCorner", pt(30.0, 5.0)),
-            ("cornerPins/lowerLeftCorner", pt(10.0, 25.0)),
-            ("cornerPins/lowerRightCorner", pt(30.0, 25.0)),
-        ];
-        let cp = run("ec.sim.carddance", &pins, src.clone(), 0.0);
-        assert_eq!(cp.get(3, 3)[3], 0.0, "outside the pinned quad");
-        assert!(cp.get(20, 15)[3] > 0.99);
-        assert!((cp.get(20, 15)[0] - src.get(20, 15)[0]).abs() < 0.05, "centre maps to centre");
-        // Comp Camera: the identity camera reproduces the layer; a camera that doubles x moves it.
-        let ident = Scene { camera: Some([[1.0, 0.0, 0.0, 0.0], [0.0, 1.0, 0.0, 0.0], [0.0, 0.0, 0.002, 1.0]]), light: None, layer: None };
-        let cc = run_env("ec.sim.carddance", &[("cameraSystem", Value::Enum(2))], src.clone(), 0.0, &ident);
-        assert!(max_diff(&cc, &src) < 0.02, "{}", max_diff(&cc, &src));
-        let half = Scene { camera: Some([[0.5, 0.0, 0.0, 0.0], [0.0, 0.5, 0.0, 0.0], [0.0, 0.0, 0.002, 1.0]]), ..ident };
-        let cc = run_env("ec.sim.carddance", &[("cameraSystem", Value::Enum(2))], src.clone(), 0.0, &half);
-        assert_eq!(cc.get(35, 25)[3], 0.0, "half-size view leaves the far corner empty");
-    }
-
-    #[test]
-    fn card_dance_lighting_and_material() {
-        let src = Image::filled(40, 30, [0.5, 0.5, 0.5, 1.0]);
-        let tilt = [("rows", num(1.0)), ("columns", num(1.0)), ("yRotation/yRotSource", Value::Enum(0)), ("yRotation/yRotOffset", num(60.0))];
-        let lit = |extra: &[(&str, Value)]| {
-            let mut v: Vec<(&str, Value)> = tilt.to_vec();
-            v.extend_from_slice(extra);
-            run("ec.sim.carddance", &v, src.clone(), 0.0).get(20, 15)
-        };
-        let base = lit(&[]);
-        // Tilted cards facing away from a frontal light get darker than flat ones.
-        assert!(base[0] < 0.45, "{base:?}");
-        // Light colour tints; intensity brightens; ambient alone lights evenly.
-        let red = lit(&[("lighting/lightColor", col(1.0, 0.0, 0.0))]);
-        assert!(red[0] > red[1] + 0.05);
-        assert!(lit(&[("lighting/lightIntensity", num(2.0))])[0] > base[0]);
-        let amb = lit(&[("lighting/ambientLight", num(1.0)), ("material/diffuse", num(0.0))]);
-        assert!((amb[0] - 0.5).abs() < 1e-3);
-        // A light placed to the side (Point Source) changes the shading of the tilted card.
-        let side = lit(&[("lighting/lightType", Value::Enum(1)), ("lighting/lightPosition", pt(200.0, 15.0)), ("lighting/lightDepth", num(0.2))]);
-        assert!((side[0] - base[0]).abs() > 0.02, "{side:?} vs {base:?}");
-        // Specular adds a highlight on flat, frontally lit cards.
-        let flat = run("ec.sim.carddance", &[("material/specular", num(0.5))], src.clone(), 0.0).get(20, 15);
-        assert!(flat[0] > 0.9, "{flat:?}");
-        // First Comp Light: no light in the comp → ambient only; a light from the host is used.
-        let none = Scene { camera: None, light: None, layer: None };
-        let a = run_env("ec.sim.carddance", &[("lighting/lightType", Value::Enum(2))], src.clone(), 0.0, &none).get(20, 15);
-        assert!((a[0] - 0.5 * (0.25 + 0.75)).abs() < 1e-3, "{a:?}");
-        let blue = Scene { light: Some(crate::CompLight { pos: [20.0, 15.0, -100.0], dir: [0.0, 0.0, 1.0], color: [0.0, 0.0, 1.0], kind: 0 }), ..none };
-        let a = run_env("ec.sim.carddance", &[("lighting/lightType", Value::Enum(2))], src.clone(), 0.0, &blue).get(20, 15);
-        assert!(a[2] > a[0] + 0.2, "{a:?}");
-    }
-
-    #[test]
-    fn shatter_custom_map_gradient_textures_and_extrusion() {
-        let src = ramp(32, 32);
-        let base = [("view", Value::Enum(0)), ("force1/force1Position", pt(16.0, 16.0)), ("force1/force1Radius", num(2.0)), ("shape/origin", pt(16.0, 16.0))];
-        let with = |extra: &[(&str, Value)], t: f64, host: Option<&Scene>| {
-            let mut v: Vec<(&str, Value)> = base.to_vec();
-            v.extend_from_slice(extra);
-            match host {
-                Some(h) => run_env("ec.sim.shatter", &v, src.clone(), t, h),
-                None => run("ec.sim.shatter", &v, src.clone(), t),
-            }
-        };
-        // Custom Shatter Map: a map white on the left and black on the right; with White Tiles
-        // Fixed the left half stays put while the right half breaks away.
-        let mut map = Image::new(32, 32);
-        for y in 0..32 {
-            for x in 0..32 {
-                map.set(x, y, if x < 16 { [1.0; 4] } else { [0.0, 0.0, 0.0, 1.0] });
-            }
-        }
-        let host = Scene { camera: None, light: None, layer: Some(map) };
-        let custom = [("shape/pattern", Value::Enum(5)), ("shape/customShatterMap", Value::Layer(Some(1))), ("shape/whiteTilesFixed", Value::Bool(true))];
-        let at_rest = with(&custom, 0.0, Some(&host));
-        assert!(max_diff(&at_rest, &src) < 0.05, "custom pieces tile the layer: {}", max_diff(&at_rest, &src));
-        let broke = with(&custom, 1.0, Some(&host));
-        assert!(max_diff_region(&broke, &src, 0..12) < 0.05, "white tiles fixed");
-        assert!(sum_diff_region(&broke, &src, 20..32) > 5.0, "black group moved");
-        // Gradient: a black gradient layer with threshold 50 % keeps everything together.
-        let black = Scene { camera: None, light: None, layer: Some(Image::filled(32, 32, [0.0, 0.0, 0.0, 1.0])) };
-        let g = with(&[("gradient/gradientLayer", Value::Layer(Some(1))), ("gradient/shatterThreshold", num(50.0))], 1.0, Some(&black));
-        assert!(max_diff(&g, &src) < 0.05);
-        let gi = with(
-            &[("gradient/gradientLayer", Value::Layer(Some(1))), ("gradient/shatterThreshold", num(50.0)), ("gradient/invertGradient", Value::Bool(true))],
-            1.0,
-            Some(&black),
-        );
-        assert!(sum_diff(&gi, &src) > 10.0);
-        // Textures: Front Mode Color paints the pieces flat; Opacity fades them.
-        let flat = with(&[("textures/frontMode", Value::Enum(0)), ("textures/color", col(0.0, 1.0, 0.0))], 0.0, None);
-        let p = flat.get(16, 16);
-        assert!(p[1] > 0.95 && p[0] < 0.05, "{p:?}");
-        let half = with(&[("textures/opacity", num(0.5)), ("shape/repetitions", num(2.0))], 0.0, None);
-        assert!((half.get(8, 4)[3] - 0.5).abs() < 0.02, "{:?}", half.get(8, 4));
-        // Extrusion: thicker pieces cover more once they tumble.
-        let cover = |d: f64| {
-            with(&[("shape/extrusionDepth", num(d)), ("textures/sideMode", Value::Enum(0)), ("textures/color", col(1.0, 1.0, 1.0))], 0.6, None)
-                .data
-                .iter()
-                .map(|p| p[3])
-                .sum::<f32>()
-        };
-        assert!(cover(1.0) > cover(0.0) + 1.0, "{} vs {}", cover(1.0), cover(0.0));
-        // Deterministic and seek-consistent.
-        assert_eq!(with(&custom, 0.7, Some(&host)), with(&custom, 0.7, Some(&host)));
-    }
-
-    fn max_diff_region(a: &Image, b: &Image, xs: std::ops::Range<u32>) -> f32 {
-        let mut m = 0.0f32;
-        for y in 0..a.height {
-            for x in xs.clone() {
-                let (p, q) = (a.get(x as i64, y as i64), b.get(x as i64, y as i64));
-                m = (0..4).map(|k| (p[k] - q[k]).abs()).fold(m, f32::max);
-            }
-        }
-        m
-    }
-
-    fn sum_diff_region(a: &Image, b: &Image, xs: std::ops::Range<u32>) -> f32 {
-        let mut s = 0.0;
-        for y in 0..a.height {
-            for x in xs.clone() {
-                let (p, q) = (a.get(x as i64, y as i64), b.get(x as i64, y as i64));
-                s += (0..4).map(|k| (p[k] - q[k]).abs()).sum::<f32>();
-            }
-        }
-        s
-    }
-
-    /// Layer 1 = a left-dark, right-light ramp; layer 2 = solid green.
-    struct FoamHost;
-    impl crate::EffectHost for FoamHost {
-        fn layer(&self, id: u64, _: bool) -> Option<crate::LayerPixels> {
-            let img = if id == 1 { ramp(32, 32) } else { Image::filled(32, 32, [0.0, 1.0, 0.0, 1.0]) };
-            Some(crate::LayerPixels { buf: Buf { img, offset: [0.0; 2], scale: 1.0 }, size: [32.0, 32.0] })
-        }
-        fn layer_at(&self, id: u64, _: f64, me: bool) -> Option<crate::LayerPixels> {
-            self.layer(id, me)
-        }
-        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
-            None
-        }
-    }
-
-    #[test]
-    fn foam_flow_map_pop_velocity_wobble_textures_and_reflection() {
-        let base = vec![
-            ("producer/producerPoint", pt(16.0, 16.0)),
-            ("producer/productionRate", num(2.0)),
-            ("physics/windSpeed", num(0.0)),
-            ("physics/turbulence", num(0.0)),
-            ("view", Value::Enum(2)),
-        ];
-        let with = |extra: &[(&str, Value)], t: f64| {
-            let mut v = base.clone();
-            v.extend_from_slice(extra);
-            run_fx("ec.sim.foam", &v, Image::new(32, 32), t, EffectEnv { host: Some(&FoamHost), ..Default::default() }).img
-        };
-        let cx = |img: &Image| {
-            let (mut s, mut n) = (0.0, 0.0);
-            for y in 0..32 {
-                for x in 0..32 {
-                    let a = img.get(x, y)[3];
-                    s += a * x as f32;
-                    n += a;
-                }
-            }
-            s / n.max(1e-6)
-        };
-        // Flow map: bubbles run downhill (towards the dark left side).
-        let still = with(&[], 1.0);
-        let flowing = with(&[("flowMap/flowMap", Value::Layer(Some(1))), ("flowMap/flowMapSteepness", num(1.0))], 1.0);
-        assert!(cx(&flowing) < cx(&still) - 1.0, "{} vs {}", cx(&flowing), cx(&still));
-        let hq =
-            with(&[("flowMap/flowMap", Value::Layer(Some(1))), ("flowMap/flowMapSteepness", num(1.0)), ("flowMap/simulationQuality", Value::Enum(2))], 1.0);
-        assert_eq!(
-            hq,
-            with(&[("flowMap/flowMap", Value::Layer(Some(1))), ("flowMap/flowMapSteepness", num(1.0)), ("flowMap/simulationQuality", Value::Enum(2))], 1.0)
-        );
-        // Pop velocity scatters the survivors when short-lived bubbles pop.
-        let short = [("bubbles/lifespan", num(8.0)), ("bubbles/strength", num(0.0))];
-        let a = with(&[short.as_slice(), &[("physics/popVelocity", num(0.0))]].concat(), 1.0);
-        let b2 = with(&[short.as_slice(), &[("physics/popVelocity", num(20.0))]].concat(), 1.0);
-        assert_ne!(a, b2);
-        // Wobble changes the drawn bubbles.
-        assert_ne!(with(&[("physics/wobbleAmount", num(0.0))], 1.0), with(&[("physics/wobbleAmount", num(3.0))], 1.0));
-        // User Defined texture: bubbles show the texture layer (green).
-        let tex = with(&[("rendering/bubbleTexture", Value::Enum(5)), ("rendering/bubbleTextureLayer", Value::Layer(Some(2)))], 1.0);
-        assert!(tex.data.iter().any(|p| p[1] > 0.5 && p[0] < 0.1));
-        // Environment map: reflections tint the bubbles.
-        let refl = with(&[("rendering/environmentMap", Value::Layer(Some(2))), ("rendering/reflectionStrength", num(1.0))], 1.0);
-        let g = |i: &Image| i.data.iter().map(|p| p[1] - p[0]).sum::<f32>();
-        assert!(g(&refl) > g(&still) + 1.0);
-        // Zoom Producer Point zooms about the producer instead of the layer centre.
-        let off = [("producer/producerPoint", pt(8.0, 8.0)), ("zoom", num(2.0))];
-        let z1 = with(&off, 1.0);
-        let z2 = with(&[off.as_slice(), &[("producer/zoomProducerPoint", Value::Bool(true))]].concat(), 1.0);
-        assert!((cx(&z2) - 8.0).abs() < 2.0 && cx(&z1) < 4.0, "{} vs {}", cx(&z2), cx(&z1));
-    }
-}
+mod tests;
diff --git a/crates/effects/src/sim2/foam.rs b/crates/effects/src/sim2/foam.rs
new file mode 100644
index 000000000..fc187d191
--- /dev/null
+++ b/crates/effects/src/sim2/foam.rs
@@ -0,0 +1,411 @@
+use super::{
+    Acc, Buf, EffectCtx, Image, IndexedParallelIterator, IntoParallelRefIterator, IntoParallelRefMutIterator, ParallelIterator, Plane, Px, Shape, SimCache,
+    Sprite, Value, hs, params_key, splat, unpremul, value_noise,
+};
+
+// ------------------------------------------------------------------ Foam
+
+#[derive(Clone, Debug)]
+struct FoamBubble {
+    p: [f32; 2],
+    v: [f32; 2],
+    age: f32,
+    size: f32,
+    /// Spin (radians) for Physical Orientation.
+    spin: f32,
+    id: u32,
+}
+
+#[derive(Clone, Debug, Default)]
+struct FoamState {
+    b: Vec<FoamBubble>,
+    carry: f32,
+    next: u32,
+}
+
+static FOAM_CACHE: SimCache<FoamState> = SimCache::new(4);
+
+/// Foam steps once per frame at 30 frames per second.
+const FOAM_FPS: f64 = 30.0;
+
+/// Foam's Bubble Texture options (the last uses Bubble Texture Layer).
+pub(super) const FOAM_TEXTURES: [&str; 6] = ["Default Bubble", "Spit", "Bubblegum", "Dishwater", "Milky", "User Defined"];
+
+/// Age (in simulation steps) at which bubble `id` pops: its lifespan, shortened at random for
+/// frail bubbles (`frailty` 0 = every bubble reaches `lifespan`, 1 = uniformly early).
+pub(super) fn foam_pop_age(id: u32, lifespan: f32, frailty: f32, seed: u32) -> f32 {
+    lifespan * (1.0 - frailty * (hs(id, 11, seed) * 0.5 + 0.5))
+}
+
+/// Foam: bubbles born in the producer rectangle grow to their size, drift with the wind,
+/// turbulence and the Flow Map (bubbles run downhill on its luminance), repel and stick to each
+/// other, wobble, and pop at the end of their (Strength-shortened) lifespan, pushing their
+/// neighbours away at Pop Velocity. Rendered bubbles use a built-in texture or the Bubble
+/// Texture Layer, oriented by Bubble Orientation, and reflect the Environment Map.
+pub(super) fn foam(ctx: &EffectCtx, b: Buf) -> Buf {
+    foam_full_plan(ctx, &b).finish(b)
+}
+
+/// Foam's bubbles as sprites, `None` when it draws more than sprites (a User Defined bubble
+/// texture, an Environment Map reflection or the Draft + Flow Map view's flow map).
+pub(crate) fn foam_plan(ctx: &EffectCtx, b: &Buf) -> Option<crate::sim::SpritePlan> {
+    let plan = foam_full_plan(ctx, b);
+    (plan.user.is_none() && plan.env.is_none() && plan.flow.is_none()).then_some(plan.sprites)
+}
+
+/// A bubble disc filled by Foam's User Defined texture (buffer px; `rot` radians).
+#[derive(Clone, Copy, Debug)]
+pub struct FoamDisc {
+    pub x: f64,
+    pub y: f64,
+    pub r: f32,
+    pub rot: f32,
+    pub fade: f32,
+}
+
+/// Foam's Environment Map reflection: the map fitted to the buffer, Reflection Convergence and
+/// Strength, and the bubble discs reflecting it (`rot` and `fade` unused).
+pub struct FoamEnv {
+    pub img: Image,
+    pub conv: f64,
+    pub strength: f32,
+    pub discs: Vec<FoamDisc>,
+}
+
+/// What Foam draws this frame over a transparent frame of the layer's size: the bubble sprites,
+/// then the User Defined texture's discs, the Environment Map's reflections and (Draft + Flow
+/// Map) the flow map under it all, each `foam_disc`-composited in bubble order.
+pub struct FoamPlan {
+    pub sprites: crate::sim::SpritePlan,
+    pub user: Option<(crate::LayerPixels, Vec<FoamDisc>)>,
+    pub env: Option<FoamEnv>,
+    /// The flow map fitted to the buffer.
+    pub flow: Option<Image>,
+}
+
+impl FoamPlan {
+    pub fn finish(&self, b: Buf) -> Buf {
+        let mut out = splat(b.img.width, b.img.height, &self.sprites.sprites, self.sprites.acc);
+        // User Defined: the texture layer fills each bubble's disc.
+        if let Some((tex, discs)) = &self.user {
+            for d in discs {
+                let (rot, fade) = (d.rot, d.fade);
+                foam_disc(&mut out, d.x, d.y, d.r as f64, |u, v| {
+                    // u, v in −1..1 across the bubble, rotated into the texture.
+                    let (sr, cr) = rot.sin_cos();
+                    let (tu, tv) = (u as f32 * cr + v as f32 * sr, -u as f32 * sr + v as f32 * cr);
+                    let (x, y) = ((tu as f64 * 0.5 + 0.5) * tex.size[0], (tv as f64 * 0.5 + 0.5) * tex.size[1]);
+                    let px = tex.buf.img.sample_bilinear(x * tex.buf.scale + tex.buf.offset[0], y * tex.buf.scale + tex.buf.offset[1]);
+                    px.map(|c| c * fade)
+                });
+            }
+        }
+        // Environment Map: each bubble reflects the map along its sphere normal (Reflection
+        // Convergence pulls the reflection towards the bubble's own spot of the map).
+        if let Some(env) = &self.env {
+            let (conv, strength) = (env.conv, env.strength);
+            let (w, h) = (b.img.width as f64, b.img.height as f64);
+            for d in &env.discs {
+                let (bx, by) = (d.x, d.y);
+                foam_disc(&mut out, bx, by, d.r as f64, |u, v| {
+                    // Sphere normal; the reflection looks across the whole map, or (convergence 1)
+                    // just behind the bubble.
+                    let (ex, ey) =
+                        if conv >= 1.0 { (bx, by) } else { (bx * conv + (u * 0.5 + 0.5) * w * (1.0 - conv), by * conv + (v * 0.5 + 0.5) * h * (1.0 - conv)) };
+                    let e = env.img.sample_bilinear(ex, ey);
+                    let rim = ((u * u + v * v) as f32).min(1.0);
+                    let k = strength * (0.3 + 0.7 * rim);
+                    [e[0] * k, e[1] * k, e[2] * k, 0.0]
+                });
+            }
+        }
+        // Draft + Flow Map shows the flow map under the bubbles.
+        if let Some(fm) = &self.flow {
+            out.data.par_iter_mut().zip(fm.data.par_iter()).for_each(|(o, f)| {
+                let k = 1.0 - o[3];
+                for c in 0..4 {
+                    o[c] += f[c] * 0.5 * k;
+                }
+            });
+        }
+        Buf { img: out, ..b }
+    }
+}
+
+/// Foam's [`FoamPlan`] for layer geometry `b` (its size; its pixels are not read).
+pub fn foam_full_plan(ctx: &EffectCtx, b: &Buf) -> FoamPlan {
+    let pr = ctx.params;
+    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
+    let unit = lw * 0.01;
+    let prod = pr.v2("producer/producerPoint");
+    let (psx, psy) = (pr.f("producer/producerXSize") as f32 * lw, pr.f("producer/producerYSize") as f32 * lh);
+    let porient = (pr.f("producer/producerOrientation") as f32).to_radians();
+    let rate = pr.f("producer/productionRate").max(0.0) as f32;
+    let size = pr.f("bubbles/size").max(0.0) as f32;
+    let size_var = pr.f("bubbles/sizeVariance") as f32;
+    let lifespan = pr.f("bubbles/lifespan").max(1.0) as f32;
+    let growth = pr.f("bubbles/growthSpeed").max(0.0001) as f32;
+    // Strength: weaker bubbles tend to pop before their lifespan (at 20 or more every bubble
+    // lives the full lifespan); each bubble gets its own pop age.
+    let frailty = 1.0 - (pr.f("bubbles/strength") as f32 / 20.0).clamp(0.0, 1.0);
+    let init_speed = pr.f("physics/initialSpeed") as f32;
+    let init_dir = (pr.f("physics/initialDirection") as f32).to_radians();
+    let wind = pr.f("physics/windSpeed") as f32;
+    let wind_dir = (pr.f("physics/windDirection") as f32).to_radians();
+    let turb = pr.f("physics/turbulence") as f32;
+    let wobble = pr.f("physics/wobbleAmount").max(0.0) as f32;
+    let repulsion = pr.f("physics/repulsion") as f32;
+    let pop_velocity = pr.f("physics/popVelocity") as f32;
+    let viscosity = pr.f("physics/viscosity").clamp(0.0, 1.0) as f32;
+    let sticky = pr.f("physics/stickiness").clamp(0.0, 1.0) as f32;
+    let universe = pr.f("universeSize").max(0.01) as f32;
+    let seed = (pr.f("randomSeed") as u32).wrapping_mul(0x68e31da4) ^ ctx.seed;
+    let wvec = [wind_dir.sin() * wind * unit, -wind_dir.cos() * wind * unit];
+    // Flow Map: the map layer's first frame, its luminance a height field (Fits the layer or
+    // the whole universe).
+    let flow = pr.get("flowMap/flowMap").and_then(Value::as_layer).and_then(|id| {
+        let host = ctx.env.host?;
+        let me = pr.get(&crate::layer_source_id("flowMap/flowMap")).is_none_or(|v| v.as_enum() != 0);
+        host.layer_at(id, ctx.env.comp_time - ctx.time, me)
+    });
+    let steep = pr.f("flowMap/flowMapSteepness") as f32;
+    let fits_universe = pr.e("flowMap/flowMapFits") == 1;
+    let substeps = match pr.e("flowMap/simulationQuality") {
+        1 => 2,
+        2 => 4,
+        _ => 1,
+    };
+    let height = flow.as_ref().map(|lp| {
+        let img = &lp.buf.img;
+        let pl = Plane::from_image(img, |px| {
+            let (c, a) = unpremul(px);
+            effectcraft_color::luminance(c[0], c[1], c[2]) * a
+        });
+        (pl, lp.buf.scale, lp.buf.offset, lp.size)
+    });
+    let (ux0, uy0) = (-(universe - 1.0) * 0.5 * lw, -(universe - 1.0) * 0.5 * lh);
+    let (ux1, uy1) = (lw - ux0, lh - uy0);
+    // Height at a layer point (0..1).
+    let h_at = |x: f32, y: f32| -> f32 {
+        let Some((pl, s, off, size)) = &height else { return 0.0 };
+        let (fx, fy) = if fits_universe { ((x - ux0) / (ux1 - ux0), (y - uy0) / (uy1 - uy0)) } else { (x / lw, y / lh) };
+        pl.sample(fx as f64 * size[0] * s + off[0], fy as f64 * size[1] * s + off[1])
+    };
+    let mut key = params_key(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, 5);
+    if let Some((pl, ..)) = &height {
+        key ^= pl.data.iter().step_by(5).fold(0u64, |a, v| a.rotate_left(3) ^ v.to_bits() as u64);
+    }
+    let steps = if ctx.time <= 0.0 { 0 } else { (ctx.time * FOAM_FPS + 1e-6).floor() as u64 };
+    let rad = |q: &FoamBubble| q.size * unit * 3.0 * (q.age * growth).min(1.0);
+    let st = FOAM_CACHE.run(key, steps, FoamState::default, |st, step| {
+        let t = step as f32 / FOAM_FPS as f32;
+        // Births.
+        st.carry += rate;
+        let n = st.carry.floor() as u32;
+        st.carry -= n as f32;
+        for _ in 0..n {
+            if st.b.len() >= 3000 {
+                break;
+            }
+            let id = st.next;
+            st.next = st.next.wrapping_add(1);
+            let (ux, uy) = (hs(id, 1, seed) * 0.5 * psx, hs(id, 2, seed) * 0.5 * psy);
+            let (so, co) = porient.sin_cos();
+            let p = [prod[0] as f32 + ux * co - uy * so, prod[1] as f32 + ux * so + uy * co];
+            let v = [init_dir.sin() * init_speed * unit, -init_dir.cos() * init_speed * unit];
+            let sz = (size * (1.0 + size_var * hs(id, 3, seed))).max(0.01);
+            st.b.push(FoamBubble { p, v, age: 0.0, size: sz, spin: hs(id, 12, seed) * std::f32::consts::PI, id });
+        }
+        for _ in 0..substeps {
+            let k = 1.0 / substeps as f32;
+            // Forces: drift towards the wind, turbulence, viscosity, the flow map's slope.
+            for q in st.b.iter_mut() {
+                let n1 = value_noise(q.p[0] / (lw * 0.15), q.p[1] / (lw * 0.15), t * 0.5, seed) - 0.5;
+                let n2 = value_noise(q.p[0] / (lw * 0.15) + 19.0, q.p[1] / (lw * 0.15), t * 0.5, seed) - 0.5;
+                for c in 0..2 {
+                    q.v[c] += (wvec[c] - q.v[c]) * 0.1 * k;
+                    q.v[c] *= 1.0 - viscosity * 0.5 * k;
+                }
+                q.v[0] += n1 * turb * unit * k;
+                q.v[1] += n2 * turb * unit * k;
+                if height.is_some() && steep != 0.0 {
+                    let e = unit.max(1.0);
+                    let gx = (h_at(q.p[0] + e, q.p[1]) - h_at(q.p[0] - e, q.p[1])) / (2.0 * e);
+                    let gy = (h_at(q.p[0], q.p[1] + e) - h_at(q.p[0], q.p[1] - e)) / (2.0 * e);
+                    // Downhill: from light (high) to dark (low).
+                    q.v[0] -= gx * steep * lw * 0.5 * k;
+                    q.v[1] -= gy * steep * lw * 0.5 * k;
+                }
+                // Physical Orientation: bubbles roll with their sideways motion.
+                q.spin += q.v[0] / (rad(q).max(0.5)) * k;
+            }
+            // Repulsion between overlapping bubbles (grid hashed, deterministic order).
+            if repulsion > 0.0 && st.b.len() > 1 {
+                let maxr = st.b.iter().map(rad).fold(0.0f32, f32::max).max(1.0);
+                let cs = maxr * 2.0;
+                let mut grid: std::collections::HashMap<(i32, i32), Vec<usize>> = std::collections::HashMap::new();
+                for (i, q) in st.b.iter().enumerate() {
+                    grid.entry(((q.p[0] / cs).floor() as i32, (q.p[1] / cs).floor() as i32)).or_default().push(i);
+                }
+                let mut push = vec![[0.0f32; 2]; st.b.len()];
+                for (i, q) in st.b.iter().enumerate() {
+                    let (gx, gy) = ((q.p[0] / cs).floor() as i32, (q.p[1] / cs).floor() as i32);
+                    for dy in -1..=1 {
+                        for dx in -1..=1 {
+                            let Some(list) = grid.get(&(gx + dx, gy + dy)) else { continue };
+                            for &j in list {
+                                if j <= i {
+                                    continue;
+                                }
+                                let o = &st.b[j];
+                                let (ddx, ddy) = (o.p[0] - q.p[0], o.p[1] - q.p[1]);
+                                let d = (ddx * ddx + ddy * ddy).sqrt().max(1e-4);
+                                let overlap = rad(q) + rad(o) - d;
+                                if overlap > 0.0 {
+                                    let f = overlap * 0.5 * repulsion.min(4.0) * (1.0 - sticky * 0.5) / d * k;
+                                    push[i][0] -= ddx * f;
+                                    push[i][1] -= ddy * f;
+                                    push[j][0] += ddx * f;
+                                    push[j][1] += ddy * f;
+                                }
+                            }
+                        }
+                    }
+                }
+                for (q, d) in st.b.iter_mut().zip(&push) {
+                    q.p[0] += d[0].clamp(-maxr, maxr);
+                    q.p[1] += d[1].clamp(-maxr, maxr);
+                }
+            }
+            for q in st.b.iter_mut() {
+                q.p[0] += q.v[0] * k;
+                q.p[1] += q.v[1] * k;
+            }
+        }
+        for q in st.b.iter_mut() {
+            q.age += 1.0;
+        }
+        // Pops: bubbles past their pop age burst, pushing their neighbours away.
+        let popped: Vec<([f32; 2], f32)> = st.b.iter().filter(|q| q.age >= foam_pop_age(q.id, lifespan, frailty, seed)).map(|q| (q.p, rad(q))).collect();
+        if pop_velocity != 0.0 {
+            for (pp, pr_) in &popped {
+                let reach = (pr_ * 3.0).max(unit);
+                for q in st.b.iter_mut() {
+                    let (dx, dy) = (q.p[0] - pp[0], q.p[1] - pp[1]);
+                    let d = (dx * dx + dy * dy).sqrt();
+                    if d > 1e-4 && d < reach {
+                        let f = pop_velocity * unit * (1.0 - d / reach) / d;
+                        q.v[0] += dx * f;
+                        q.v[1] += dy * f;
+                    }
+                }
+            }
+        }
+        st.b.retain(|q| q.age < foam_pop_age(q.id, lifespan, frailty, seed) && q.p[0] > ux0 && q.p[0] < ux1 && q.p[1] > uy0 && q.p[1] < uy1);
+    });
+    let view = pr.e("view");
+    let zoom = pr.f("zoom").max(0.01) as f32;
+    let zoom_producer = pr.b("producer/zoomProducerPoint");
+    let texture = pr.e("rendering/bubbleTexture");
+    let orient = pr.e("rendering/bubbleOrientation");
+    let blend = pr.e("rendering/blendMode");
+    let s = b.scale as f32;
+    // Zoom centres on the layer, or on the producer with Zoom Producer Point.
+    let (cx, cy) = if zoom_producer { (prod[0] as f32, prod[1] as f32) } else { (lw * 0.5, lh * 0.5) };
+    let mut order: Vec<&FoamBubble> = st.b.iter().collect();
+    if blend == 2 {
+        // Solid New on Top: oldest first.
+        order.sort_by(|a, c| c.age.total_cmp(&a.age).then(a.id.cmp(&c.id)));
+    } else if blend == 1 {
+        order.sort_by(|a, c| a.age.total_cmp(&c.age).then(a.id.cmp(&c.id)));
+    }
+    // Where a bubble is drawn: buffer centre, radius, rotation (radians).
+    let place = |q: &FoamBubble| {
+        let wob = if wobble > 0.0 { 1.0 + wobble * 0.15 * ((q.age * 0.35) + hs(q.id, 13, seed) * 6.0).sin() } else { 1.0 };
+        let r = rad(q) * wob * zoom * s;
+        let (bx, by) = b.to_px([(cx + (q.p[0] - cx) * zoom) as f64, (cy + (q.p[1] - cy) * zoom) as f64]);
+        let rot = match orient {
+            1 => q.spin,
+            2 => q.v[1].atan2(q.v[0]),
+            _ => 0.0,
+        };
+        (bx, by, r, rot)
+    };
+    let user_tex = (view == 2 && texture == 5).then(|| ctx.layer_param("rendering/bubbleTextureLayer", true)).flatten();
+    let sprites: Vec<Sprite> = order
+        .iter()
+        .filter(|_| user_tex.is_none())
+        .map(|q| {
+            let (bx, by, r, rot) = place(q);
+            let fade = ((foam_pop_age(q.id, lifespan, frailty, seed) - q.age) / 5.0).clamp(0.0, 1.0);
+            // Draft and Draft + Flow Map show the wireframe-style bubbles.
+            let mut sp = if view != 2 {
+                Sprite::new(bx as f32, by as f32, r, [0.55, 0.75, 1.0, fade], Shape::Bubble)
+            } else {
+                let (c, shape) = match texture {
+                    1 => ([0.95, 0.95, 0.92], Shape::Faded),
+                    2 => ([1.0, 0.6, 0.8], Shape::Bubble),
+                    3 => ([0.8, 0.85, 0.75], Shape::Bubble),
+                    4 => ([0.97, 0.97, 0.95], Shape::Sphere),
+                    _ => ([1.0, 1.0, 1.0], Shape::Bubble),
+                };
+                Sprite::new(bx as f32, by as f32, r, [c[0], c[1], c[2], fade], shape)
+            };
+            sp.rot = rot;
+            sp
+        })
+        .collect();
+    let acc = if blend == 0 && view == 2 { Acc::Add } else { Acc::Over };
+    let disc = |q: &&FoamBubble| {
+        let (x, y, r, rot) = place(q);
+        let fade = ((foam_pop_age(q.id, lifespan, frailty, seed) - q.age) / 5.0).clamp(0.0, 1.0);
+        FoamDisc { x, y, r, rot, fade }
+    };
+    let user = user_tex.map(|tex| (tex, order.iter().map(disc).collect()));
+    let strength = pr.f("rendering/reflectionStrength").clamp(0.0, 1.0) as f32;
+    let env = if view == 2
+        && strength > 0.0
+        && let Some(env) = ctx.layer_param("rendering/environmentMap", true)
+    {
+        Some(FoamEnv {
+            img: crate::util::fit_layer(ctx, b, &env, true),
+            conv: pr.f("rendering/reflectionConvergence").clamp(0.0, 1.0),
+            strength,
+            discs: order.iter().map(disc).collect(),
+        })
+    } else {
+        None
+    };
+    let flow = if view == 1
+        && let Some(lp) = &flow
+    {
+        Some(crate::util::fit_layer(ctx, b, lp, true))
+    } else {
+        None
+    };
+    FoamPlan { sprites: crate::sim::SpritePlan { sprites, tints: vec![], acc, post: crate::sim::Post::Replace }, user, env, flow }
+}
+
+/// Add `f(u, v)` (premultiplied; u, v ∈ −1..1 across the disc) over the disc of radius `r` at
+/// (`x`, `y`) with anti-aliased edges ("over" for opaque texels, additive for alpha 0).
+fn foam_disc(out: &mut Image, x: f64, y: f64, r: f64, f: impl Fn(f64, f64) -> Px) {
+    if r <= 0.0 {
+        return;
+    }
+    let (x0, x1) = ((x - r - 1.0).floor().max(0.0) as i64, (x + r + 1.0).ceil().min(out.width as f64) as i64);
+    let (y0, y1) = ((y - r - 1.0).floor().max(0.0) as i64, (y + r + 1.0).ceil().min(out.height as f64) as i64);
+    for py in y0..y1 {
+        for px in x0..x1 {
+            let (u, v) = ((px as f64 + 0.5 - x) / r, (py as f64 + 0.5 - y) / r);
+            let d = (u * u + v * v).sqrt();
+            let cov = ((1.0 - d) * r + 0.5).clamp(0.0, 1.0) as f32;
+            if cov <= 0.0 {
+                continue;
+            }
+            let s = f(u.clamp(-1.0, 1.0), v.clamp(-1.0, 1.0)).map(|c| c * cov);
+            let o = out.get(px, py);
+            let k = 1.0 - s[3];
+            out.set(px as u32, py as u32, [s[0] + o[0] * k, s[1] + o[1] * k, s[2] + o[2] * k, (s[3] + o[3] * k).min(1.0)]);
+        }
+    }
+}
diff --git a/crates/effects/src/sim2/pieces.rs b/crates/effects/src/sim2/pieces.rs
new file mode 100644
index 000000000..bff5943c0
--- /dev/null
+++ b/crates/effects/src/sim2/pieces.rs
@@ -0,0 +1,277 @@
+use super::shatter::{ShatterPlan, card_dance_plan, shatter_impl};
+use super::{Acc, Buf, EffectCtx, Image, Lighting, Proj, raster, unpremul};
+
+// ------------------------------------------------------------------ 3D pieces
+
+pub(crate) type M3 = [[f64; 3]; 3];
+
+fn mat_mul(a: &M3, b: &M3) -> M3 {
+    std::array::from_fn(|i| std::array::from_fn(|j| (0..3).map(|k| a[i][k] * b[k][j]).sum()))
+}
+
+/// Rotation from Euler angles (radians), applied X then Y then Z.
+pub(super) fn rot_xyz(x: f64, y: f64, z: f64) -> M3 {
+    let (sx, cx) = x.sin_cos();
+    let (sy, cy) = y.sin_cos();
+    let (sz, cz) = z.sin_cos();
+    let rx = [[1.0, 0.0, 0.0], [0.0, cx, -sx], [0.0, sx, cx]];
+    let ry = [[cy, 0.0, sy], [0.0, 1.0, 0.0], [-sy, 0.0, cy]];
+    let rz = [[cz, -sz, 0.0], [sz, cz, 0.0], [0.0, 0.0, 1.0]];
+    mat_mul(&rz, &mat_mul(&ry, &rx))
+}
+
+/// Rotation by `angle` about unit `axis` (Rodrigues).
+pub(crate) fn rot_axis(axis: [f64; 3], angle: f64) -> M3 {
+    let l = (axis[0] * axis[0] + axis[1] * axis[1] + axis[2] * axis[2]).sqrt();
+    if l < 1e-12 || angle == 0.0 {
+        return [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]];
+    }
+    let (x, y, z) = (axis[0] / l, axis[1] / l, axis[2] / l);
+    let (s, c) = angle.sin_cos();
+    let t = 1.0 - c;
+    [
+        [t * x * x + c, t * x * y - s * z, t * x * z + s * y],
+        [t * x * y + s * z, t * y * y + c, t * y * z - s * x],
+        [t * x * z - s * y, t * y * z + s * x, t * z * z + c],
+    ]
+}
+
+pub(super) fn inv3(m: &M3) -> Option<M3> {
+    let det = m[0][0] * (m[1][1] * m[2][2] - m[1][2] * m[2][1]) - m[0][1] * (m[1][0] * m[2][2] - m[1][2] * m[2][0])
+        + m[0][2] * (m[1][0] * m[2][1] - m[1][1] * m[2][0]);
+    if det.abs() < 1e-12 {
+        return None;
+    }
+    let d = 1.0 / det;
+    Some([
+        [(m[1][1] * m[2][2] - m[1][2] * m[2][1]) * d, (m[0][2] * m[2][1] - m[0][1] * m[2][2]) * d, (m[0][1] * m[1][2] - m[0][2] * m[1][1]) * d],
+        [(m[1][2] * m[2][0] - m[1][0] * m[2][2]) * d, (m[0][0] * m[2][2] - m[0][2] * m[2][0]) * d, (m[0][2] * m[1][0] - m[0][0] * m[1][2]) * d],
+        [(m[1][0] * m[2][1] - m[1][1] * m[2][0]) * d, (m[0][1] * m[2][0] - m[0][0] * m[2][1]) * d, (m[0][0] * m[1][1] - m[0][1] * m[1][0]) * d],
+    ])
+}
+
+/// Perspective camera looking down +z at the layer plane z = 0, `d` pixels away, centred on
+/// `c` (buffer pixels): screen = c + (P - c) · d / (d + z).
+#[derive(Clone, Copy)]
+pub(super) struct Cam {
+    pub(super) c: [f64; 2],
+    pub(super) d: f64,
+}
+
+impl Cam {
+    fn proj(self) -> Proj {
+        Proj::simple(self.c, self.d)
+    }
+}
+
+/// A planar textured piece ready to draw.
+#[derive(Clone, Copy, Debug)]
+pub struct Piece {
+    /// Screen (buffer px, homogeneous) → piece-local (a, b, w).
+    pub inv: [[f64; 3]; 3],
+    /// Rest centre of the piece in texture pixels.
+    pub c0: [f32; 2],
+    /// Convex polygon (texture pixels), counter-clockwise in y-down space.
+    pub poly: [[f32; 2]; 6],
+    pub n: u8,
+    pub bbox: [f32; 4],
+    pub shade: f32,
+    /// Lighting: colour multiplier and additive specular highlight.
+    pub tint: [f32; 3],
+    pub spec: [f32; 3],
+    pub alpha: f32,
+    /// Flat straight colour instead of the texture.
+    pub flat: Option<[f32; 3]>,
+    /// Facing away from the camera (draw the back texture).
+    pub back: bool,
+    /// Back faces sample their texture mirrored about the piece centre: 0 no, 1 vertically
+    /// (flipped about the X axis), 2 horizontally (about the Y axis).
+    pub back_mirror: u8,
+    depth: f64,
+}
+
+/// A piece texture: the layer itself or another image (buffer-aligned).
+#[derive(Clone, Debug)]
+pub enum PieceTex {
+    Layer,
+    Image(Image),
+}
+
+/// What a piece-drawing effect (Card Dance, Shatter, Card Wipe) draws this frame: pieces sorted
+/// far to near over a transparent frame, textured by `front` (and `back` for pieces facing
+/// away; none = they take `front`).
+#[derive(Clone, Debug)]
+pub struct PiecePlan {
+    pub pieces: Vec<Piece>,
+    pub front: PieceTex,
+    pub back: Option<PieceTex>,
+}
+
+impl PiecePlan {
+    /// Rasterise over a transparent frame of the layer `b`'s size.
+    pub fn finish(&self, mut b: Buf) -> Buf {
+        let mut out = Image::new(b.img.width, b.img.height);
+        let front = match &self.front {
+            PieceTex::Layer => &b.img,
+            PieceTex::Image(i) => i,
+        };
+        let back = self.back.as_ref().map(|t| match t {
+            PieceTex::Layer => &b.img,
+            PieceTex::Image(i) => i,
+        });
+        draw_pieces(&mut out, &self.pieces, front, back);
+        b.img = out;
+        b
+    }
+}
+
+/// The piece plan of Card Dance, Shatter (Rendered view) or Card Wipe for layer `b` (its pixels
+/// may be read: gradient maps and textures default to the layer), `None` for other effects or
+/// views drawn otherwise.
+pub fn piece_plan(id: &str, ctx: &EffectCtx, b: &Buf) -> Option<PiecePlan> {
+    match id {
+        "ec.sim.carddance" => Some(card_dance_plan(ctx, b)),
+        "ec.sim.shatter" if ctx.params.e("view") == 0 => match shatter_impl(ctx, b) {
+            ShatterPlan::Pieces(plan) => Some(plan),
+            ShatterPlan::Wire(_) => None,
+        },
+        "ec.transition.cardwipe" => crate::transition::card_wipe_plan(ctx, b),
+        _ => None,
+    }
+}
+
+impl Piece {
+    /// Place polygon `poly` (texture px, around rest centre `c0`) with rotation `r` and its
+    /// centre at 3D `pos` (buffer px; z away from the camera), seen through `cam`.
+    pub(crate) fn new(poly: &[[f32; 2]], c0: [f32; 2], r: &M3, pos: [f64; 3], cam: impl Into<Proj>) -> Option<Piece> {
+        let cam: Proj = cam.into();
+        let n = poly.len().min(6);
+        if n < 3 {
+            return None;
+        }
+        let m = &cam.m;
+        let row = |i: usize| -> [f64; 3] {
+            [
+                m[i][0] * r[0][0] + m[i][1] * r[1][0] + m[i][2] * r[2][0],
+                m[i][0] * r[0][1] + m[i][1] * r[1][1] + m[i][2] * r[2][1],
+                m[i][0] * pos[0] + m[i][1] * pos[1] + m[i][2] * pos[2] + m[i][3],
+            ]
+        };
+        let hm: M3 = [row(0), row(1), row(2)];
+        let mut bb = [f32::INFINITY, f32::INFINITY, f32::NEG_INFINITY, f32::NEG_INFINITY];
+        for v in &poly[..n] {
+            let (a, b) = ((v[0] - c0[0]) as f64, (v[1] - c0[1]) as f64);
+            let w = hm[2][0] * a + hm[2][1] * b + hm[2][2];
+            if w < cam.near {
+                return None;
+            }
+            let sx = ((hm[0][0] * a + hm[0][1] * b + hm[0][2]) / w) as f32;
+            let sy = ((hm[1][0] * a + hm[1][1] * b + hm[1][2]) / w) as f32;
+            bb = [bb[0].min(sx), bb[1].min(sy), bb[2].max(sx), bb[3].max(sy)];
+        }
+        let inv = inv3(&hm)?;
+        let mut pp = [[0.0f32; 2]; 6];
+        pp[..n].copy_from_slice(&poly[..n]);
+        // Normalise winding so "inside" is cross >= 0 for every edge.
+        let area: f32 = (0..n).map(|i| pp[i][0] * pp[(i + 1) % n][1] - pp[(i + 1) % n][0] * pp[i][1]).sum();
+        if area < 0.0 {
+            pp[..n].reverse();
+        }
+        // The front faces -z at rest; it faces the camera when its normal points at the eye.
+        let eye = cam.eye();
+        let nrm = [-r[0][2], -r[1][2], -r[2][2]];
+        let to_eye = [eye[0] - pos[0], eye[1] - pos[1], eye[2] - pos[2]];
+        let facing = nrm[0] * to_eye[0] + nrm[1] * to_eye[1] + nrm[2] * to_eye[2];
+        let depth = hm[2][2];
+        Some(Piece {
+            inv,
+            c0,
+            poly: pp,
+            n: n as u8,
+            bbox: [bb[0] - 1.0, bb[1] - 1.0, bb[2] + 1.0, bb[3] + 1.0],
+            shade: 1.0,
+            tint: [1.0; 3],
+            spec: [0.0; 3],
+            alpha: 1.0,
+            flat: None,
+            back: facing < 0.0,
+            back_mirror: 0,
+            depth,
+        })
+    }
+
+    /// Lambert factor of the piece normal against a light shining along +z.
+    pub(super) fn facing(r: &M3) -> f32 {
+        r[2][2].abs() as f32
+    }
+
+    /// Light the piece (rotation `r`, centre `pos`) with Lighting / Material.
+    pub(crate) fn light(&mut self, l: &Lighting, r: &M3, pos: [f64; 3], eye: [f64; 3]) {
+        let (t, s) = l.shade([-r[0][2], -r[1][2], -r[2][2]], pos, eye);
+        self.tint = t;
+        self.spec = s;
+    }
+}
+
+impl From<Cam> for Proj {
+    fn from(c: Cam) -> Proj {
+        c.proj()
+    }
+}
+
+/// Draw pieces (already sorted far → near) over `out`.
+pub(crate) fn draw_pieces(out: &mut Image, pieces: &[Piece], front: &Image, back: Option<&Image>) {
+    raster(
+        out,
+        pieces,
+        |q| Some(q.bbox),
+        |q, x, y| {
+            let (xf, yf) = (x as f64, y as f64);
+            let m = &q.inv;
+            let w = m[2][0] * xf + m[2][1] * yf + m[2][2];
+            if w.abs() < 1e-12 {
+                return None;
+            }
+            let u = ((m[0][0] * xf + m[0][1] * yf + m[0][2]) / w) as f32 + q.c0[0];
+            let v = ((m[1][0] * xf + m[1][1] * yf + m[1][2]) / w) as f32 + q.c0[1];
+            let n = q.n as usize;
+            let mut md = f32::INFINITY;
+            for i in 0..n {
+                let a = q.poly[i];
+                let b = q.poly[(i + 1) % n];
+                let (ex, ey) = (b[0] - a[0], b[1] - a[1]);
+                let l = (ex * ex + ey * ey).sqrt().max(1e-6);
+                md = md.min((ex * (v - a[1]) - ey * (u - a[0])) / l);
+            }
+            // Coverage extends half a pixel past the edge so abutting pieces leave no seams.
+            let cov = (md + 1.0).clamp(0.0, 1.0);
+            if cov <= 0.0 {
+                return None;
+            }
+            let (c, a) = match q.flat {
+                Some(c) => (c, 1.0),
+                None => {
+                    let tex = if q.back { back.unwrap_or(front) } else { front };
+                    let (u, v) = match (q.back, q.back_mirror) {
+                        (true, 1) => (u, 2.0 * q.c0[1] - v),
+                        (true, 2) => (2.0 * q.c0[0] - u, v),
+                        _ => (u, v),
+                    };
+                    unpremul(tex.sample_bilinear(u as f64, v as f64))
+                }
+            };
+            let a = a * cov * q.alpha;
+            if a <= 1e-6 {
+                return None;
+            }
+            let k = q.shade;
+            let o: [f32; 3] = std::array::from_fn(|i| c[i] * k * q.tint[i] + q.spec[i]);
+            Some([o[0] * a, o[1] * a, o[2] * a, a])
+        },
+        Acc::Over,
+    );
+}
+
+pub(crate) fn sort_far_first(pieces: &mut [Piece]) {
+    pieces.sort_by(|a, b| b.depth.total_cmp(&a.depth));
+}
diff --git a/crates/effects/src/sim2/pixels.rs b/crates/effects/src/sim2/pixels.rs
new file mode 100644
index 000000000..2cda428db
--- /dev/null
+++ b/crates/effects/src/sim2/pixels.rs
@@ -0,0 +1,228 @@
+use super::pieces::{Cam, Piece, PiecePlan, PieceTex, rot_axis, sort_far_first};
+use super::shatter::{ShatterPlan, shatter_impl};
+use super::{Acc, Buf, EffectCtx, IntoParallelIterator, ParallelIterator, Post, Shape, Sprite, SpritePlan, h, hs, unpremul};
+
+// ------------------------------------------------------------------ CC Ball Action
+
+pub(super) fn ball_action(ctx: &EffectCtx, b: Buf) -> Buf {
+    ball_action_plan(ctx, &b).finish(b)
+}
+
+/// CC Ball Action's balls (far to near), coloured by the layer's pixels.
+fn ball_action_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
+    let pr = ctx.params;
+    let scatter = pr.f("scatter") as f32;
+    let axis = pr.e("rotationAxis");
+    let rot = pr.f("rotation").to_radians();
+    let twist_prop = pr.e("twistProperty");
+    let twist = pr.f("twistAngle").to_radians();
+    let spacing = pr.f("gridSpacing").max(1.0) as f32;
+    let size = pr.f("ballSize") as f32 / 100.0;
+    let instab = pr.f("instabilityState").to_radians() as f32;
+    let seed = ctx.seed.wrapping_mul(0x2545f491);
+    let (lw, lh) = (ctx.layer_size[0] as f32, ctx.layer_size[1] as f32);
+    let s = b.scale as f32;
+    let nx = (lw / spacing).ceil().max(1.0) as u32;
+    let ny = (lh / spacing).ceil().max(1.0) as u32;
+    let d = 2.0 * lw.max(lh) as f64;
+    let (cx, cy) = (lw as f64 * 0.5, lh as f64 * 0.5);
+    let src = &b.img;
+    let ax: [f64; 3] = match axis {
+        0 => [1.0, 0.0, 0.0],
+        1 => [0.0, 1.0, 0.0],
+        2 => [0.0, 0.0, 1.0],
+        3 => [1.0, 1.0, 0.0],
+        4 => [1.0, 0.0, 1.0],
+        5 => [0.0, 1.0, 1.0],
+        _ => [1.0, 1.0, 1.0],
+    };
+    let maxr = ((lw * lw + lh * lh).sqrt() * 0.5).max(1.0);
+    let mut balls: Vec<(f64, Sprite)> = (0..nx * ny)
+        .into_par_iter()
+        .filter_map(|i| {
+            let gx = (i % nx) as f32 * spacing + spacing * 0.5;
+            let gy = (i / nx) as f32 * spacing + spacing * 0.5;
+            let (sx, sy) = b.to_px([gx as f64, gy as f64]);
+            let (c, a) = unpremul(src.sample_bilinear(sx, sy));
+            if a <= 0.0 || size <= 0.0 {
+                return None;
+            }
+            let tp = match twist_prop {
+                0 => gx / lw.max(1.0),
+                1 => gy / lh.max(1.0),
+                2 => ((gx - cx as f32).hypot(gy - cy as f32)) / maxr,
+                _ => crate::util::rgb3([c[0], c[1], c[2], 0.0]).iter().sum::<f32>() / 3.0,
+            } as f64;
+            let ang = rot + twist * tp;
+            // Scatter: random 3D offsets whose direction drifts with the instability state.
+            let ph = h(i, 1, seed) * std::f32::consts::TAU + instab;
+            let sc = scatter * h(i, 2, seed);
+            let off = [(sc * ph.cos()) as f64, (sc * ph.sin()) as f64, (scatter * hs(i, 3, seed)) as f64];
+            let p0 = [gx as f64 - cx + off[0], gy as f64 - cy + off[1], off[2]];
+            let m = rot_axis(ax, ang);
+            let q: [f64; 3] = std::array::from_fn(|k| m[k][0] * p0[0] + m[k][1] * p0[1] + m[k][2] * p0[2]);
+            if d + q[2] <= d * 0.05 {
+                return None;
+            }
+            let persp = d / (d + q[2]);
+            let (bx, by) = b.to_px([cx + q[0] * persp, cy + q[1] * persp]);
+            let r = spacing * 0.5 * size * persp as f32 * s;
+            Some((q[2], Sprite::new(bx as f32, by as f32, r, [c[0], c[1], c[2], a], Shape::Sphere)))
+        })
+        .collect();
+    balls.sort_by(|a, b| b.0.total_cmp(&a.0));
+    let sprites: Vec<Sprite> = balls.into_iter().map(|(_, s)| s).collect();
+    SpritePlan { sprites, tints: vec![], acc: Acc::Over, post: Post::Replace }
+}
+
+// ------------------------------------------------------------------ CC Pixel Polly
+
+pub(super) fn pixel_polly(ctx: &EffectCtx, b: Buf) -> Buf {
+    match pixel_polly_plan(ctx, &b) {
+        Some(plan) => plan.finish(b),
+        None => b,
+    }
+}
+
+/// CC Pixel Polly's pieces, `None` before Start Time (the layer as is).
+fn pixel_polly_plan(ctx: &EffectCtx, b: &Buf) -> Option<PiecePlan> {
+    let pr = ctx.params;
+    let t = ctx.time - pr.f("startTime");
+    if t <= 0.0 {
+        return None;
+    }
+    let force = pr.f("force");
+    let gravity = pr.f("gravity");
+    let spin = pr.f("spinning").to_radians();
+    let fc = pr.v2("forceCenter");
+    let dir_rand = pr.f("directionRandomness") / 100.0;
+    let spd_rand = pr.f("speedRandomness") / 100.0;
+    let g = pr.f("gridSpacing").max(1.0);
+    let object = pr.e("object");
+    let depth_sort = pr.b("enableDepthSort");
+    let seed = ctx.seed.wrapping_mul(0x632be5ab);
+    let [lw, lh] = ctx.layer_size;
+    let s = b.scale;
+    let cam = Cam { c: [b.offset[0] + lw * 0.5 * s, b.offset[1] + lh * 0.5 * s], d: 2.0 * lw.max(lh) * s };
+    let nx = (lw / g).ceil().max(1.0) as u32;
+    let ny = (lh / g).ceil().max(1.0) as u32;
+    let tri = object <= 1;
+    let textured = object == 1 || object == 3;
+    let maxd = lw.max(lh);
+    let src = &b.img;
+    let per = if tri { 2 } else { 1 };
+    let mut pieces: Vec<Piece> = (0..nx * ny * per)
+        .into_par_iter()
+        .filter_map(|i| {
+            let cell = i / per;
+            let (x0, y0) = ((cell % nx) as f64 * g, (cell / nx) as f64 * g);
+            let poly: Vec<[f64; 2]> = if !tri {
+                vec![[x0, y0], [x0 + g, y0], [x0 + g, y0 + g], [x0, y0 + g]]
+            } else if i % 2 == 0 {
+                vec![[x0, y0], [x0 + g, y0], [x0, y0 + g]]
+            } else {
+                vec![[x0 + g, y0], [x0 + g, y0 + g], [x0, y0 + g]]
+            };
+            let c = [poly.iter().map(|v| v[0]).sum::<f64>() / poly.len() as f64, poly.iter().map(|v| v[1]).sum::<f64>() / poly.len() as f64];
+            let (dx, dy) = (c[0] - fc[0], c[1] - fc[1]);
+            let dist = (dx * dx + dy * dy).sqrt().max(1e-6);
+            let ang = dy.atan2(dx) + dir_rand * std::f64::consts::PI * hs(i, 1, seed) as f64;
+            let speed = force / 100.0 * 0.6 * maxd / (1.0 + dist / (0.5 * maxd)) * (1.0 + spd_rand * hs(i, 2, seed) as f64);
+            let vz = -speed * 0.5 * h(i, 3, seed) as f64;
+            let pos = [c[0] + ang.cos() * speed * t, c[1] + ang.sin() * speed * t + 0.5 * gravity * 0.5 * lh * t * t, vz * t];
+            let axis = [hs(i, 4, seed) as f64, hs(i, 5, seed) as f64, hs(i, 6, seed) as f64];
+            let r = rot_axis(axis, t * (std::f64::consts::PI * h(i, 7, seed) as f64 + spin));
+            let tex: Vec<[f32; 2]> = poly.iter().map(|v| [(v[0] * s + b.offset[0]) as f32, (v[1] * s + b.offset[1]) as f32]).collect();
+            let c0 = [(c[0] * s + b.offset[0]) as f32, (c[1] * s + b.offset[1]) as f32];
+            let posb = [pos[0] * s + b.offset[0], pos[1] * s + b.offset[1], pos[2] * s];
+            let mut pc = Piece::new(&tex, c0, &r, posb, cam)?;
+            pc.shade = 0.35 + 0.65 * Piece::facing(&r);
+            if !textured {
+                let (cc, a) = unpremul(src.sample_bilinear(c0[0] as f64, c0[1] as f64));
+                if a <= 0.0 {
+                    return None;
+                }
+                pc.flat = Some(cc);
+                pc.alpha = a;
+            }
+            Some(pc)
+        })
+        .collect();
+    if depth_sort {
+        sort_far_first(&mut pieces);
+    }
+    Some(PiecePlan { pieces, front: PieceTex::Layer, back: None })
+}
+
+// ------------------------------------------------------------------ CC Scatterize
+
+pub(super) fn scatterize(ctx: &EffectCtx, b: Buf) -> Buf {
+    match scatterize_plan(ctx, &b) {
+        Some(plan) => plan.finish(b),
+        None => b,
+    }
+}
+
+/// CC Scatterize's pixel dots, `None` when nothing moves (the layer as is).
+fn scatterize_plan(ctx: &EffectCtx, b: &Buf) -> Option<SpritePlan> {
+    let pr = ctx.params;
+    let scatter = pr.f("scatter") as f32;
+    let right = pr.f("rightTwist").to_radians();
+    let left = pr.f("leftTwist").to_radians();
+    if scatter == 0.0 && right == 0.0 && left == 0.0 {
+        return None;
+    }
+    let add = pr.e("transferMode") == 1;
+    let seed = ctx.seed.wrapping_mul(0x7feb352d);
+    let s = b.scale;
+    let (w, hh) = (b.img.width, b.img.height);
+    let (cx, cy) = (b.offset[0] + ctx.layer_size[0] * 0.5 * s, b.offset[1] + ctx.layer_size[1] * 0.5 * s);
+    let half = (ctx.layer_size[0] * 0.5 * s).max(1.0);
+    let d = 2.0 * ctx.layer_size[0].max(ctx.layer_size[1]) * s;
+    let src = &b.img;
+    let sprites: Vec<Sprite> = (0..w * hh)
+        .into_par_iter()
+        .filter_map(|i| {
+            let px = src.data[i as usize];
+            if px[3] <= 0.0 {
+                return None;
+            }
+            let (x, y) = ((i % w) as f64 + 0.5, (i / w) as f64 + 0.5);
+            // Twist about the horizontal axis through the centre, growing towards each side.
+            let k = ((x - cx) / half).abs().min(1.0);
+            let ang = if x < cx { left } else { right } * k;
+            let (sa, ca) = ang.sin_cos();
+            let (yy, zz) = ((y - cy) * ca, (y - cy) * sa);
+            let persp = d / (d + zz).max(d * 0.05);
+            let jx = hs(i, 1, seed) * scatter * s as f32;
+            let jy = hs(i, 2, seed) * scatter * s as f32;
+            let sx = cx + (x - cx) * persp + jx as f64;
+            let sy = cy + yy * persp + jy as f64;
+            let (c, a) = unpremul(px);
+            Some(Sprite::new(sx as f32, sy as f32, 0.6 * persp as f32, [c[0], c[1], c[2], a], Shape::Disc))
+        })
+        .collect();
+    Some(SpritePlan { sprites, tints: vec![], acc: if add { Acc::Add } else { Acc::Over }, post: Post::Replace })
+}
+
+/// What a particle effect that reads the layer's pixels draws this frame (CC Ball Action, CC
+/// Pixel Polly, CC Scatterize, Shatter's wireframe views), for layer `b`; `None` for other
+/// effects or a frame showing the layer as is.
+pub enum PixelPlan {
+    Sprites(SpritePlan),
+    Pieces(PiecePlan),
+}
+
+/// The [`PixelPlan`] of effect `id` for layer `b` (its pixels are read).
+pub fn pixel_plan(id: &str, ctx: &EffectCtx, b: &Buf) -> Option<PixelPlan> {
+    match id {
+        "ec.sim.ccballaction" => Some(PixelPlan::Sprites(ball_action_plan(ctx, b))),
+        "ec.sim.ccpixelpolly" => pixel_polly_plan(ctx, b).map(PixelPlan::Pieces),
+        "ec.sim.ccscatterize" => scatterize_plan(ctx, b).map(PixelPlan::Sprites),
+        "ec.sim.shatter" => Some(match shatter_impl(ctx, b) {
+            ShatterPlan::Pieces(plan) => PixelPlan::Pieces(plan),
+            ShatterPlan::Wire(plan) => PixelPlan::Sprites(plan),
+        }),
+        _ => None,
+    }
+}
diff --git a/crates/effects/src/sim2/registry.rs b/crates/effects/src/sim2/registry.rs
new file mode 100644
index 000000000..333916a16
--- /dev/null
+++ b/crates/effects/src/sim2/registry.rs
@@ -0,0 +1,288 @@
+use super::foam::{FOAM_TEXTURES, foam};
+use super::pixels::{ball_action, pixel_polly, scatterize};
+use super::shatter::{CD_PROPS, CD_SOURCES, SHATTER_PATTERNS, SHATTER_TEXTURE_MODES, card_dance, shatter};
+use super::surfaces::{caustics, wave_world};
+use super::{EffectSpec, ParamUi, Value, col, num, p, pct, popup, pt, slider, spec};
+
+// ------------------------------------------------------------------ specs
+
+fn producer_params(k: u32, amp: f64, pos: (f64, f64)) -> Vec<crate::ParamSpec> {
+    let ids: [&'static str; 8] = match k {
+        1 => [
+            "producer1/producer1Type",
+            "producer1/producer1Position",
+            "producer1/producer1Length",
+            "producer1/producer1Width",
+            "producer1/producer1Angle",
+            "producer1/producer1Amplitude",
+            "producer1/producer1Frequency",
+            "producer1/producer1Phase",
+        ],
+        _ => [
+            "producer2/producer2Type",
+            "producer2/producer2Position",
+            "producer2/producer2Length",
+            "producer2/producer2Width",
+            "producer2/producer2Angle",
+            "producer2/producer2Amplitude",
+            "producer2/producer2Frequency",
+            "producer2/producer2Phase",
+        ],
+    };
+    vec![
+        p(ids[0], "Type", Value::Enum(0), popup(&["Ring", "Line"])),
+        p(ids[1], "Position", pt(pos.0, pos.1), ParamUi::Point),
+        p(ids[2], "Height/Length", num(0.1), slider(0.0, 2.0, 0.0, 1.0, 3)),
+        p(ids[3], "Width", num(0.1), slider(0.0, 2.0, 0.0, 1.0, 3)),
+        p(ids[4], "Angle", num(0.0), ParamUi::Angle),
+        p(ids[5], "Amplitude", num(amp), slider(-5.0, 5.0, -1.0, 1.0, 3)),
+        p(ids[6], "Frequency", num(1.0), slider(0.0, 30.0, 0.0, 5.0, 3)),
+        p(ids[7], "Phase", num(0.0), ParamUi::Angle),
+    ]
+}
+
+fn card_dance_params() -> Vec<crate::ParamSpec> {
+    let mut v = vec![
+        p("rowsColumns", "Rows & Columns", Value::Enum(0), popup(&["Independent", "Columns Follows Rows"])),
+        p("rows", "Rows", num(10.0), slider(1.0, 1000.0, 1.0, 100.0, 0)),
+        p("columns", "Columns", num(10.0), slider(1.0, 1000.0, 1.0, 100.0, 0)),
+        p("backLayer", "Back Layer", Value::Layer(None), ParamUi::Layer),
+        p("gradientLayer1", "Gradient Layer 1", Value::Layer(None), ParamUi::Layer),
+        p("gradientLayer2", "Gradient Layer 2", Value::Layer(None), ParamUi::Layer),
+    ];
+    let names: [[&'static str; 4]; 8] = [
+        ["xPosition/xPosSource", "xPosition/xPosMultiplier", "xPosition/xPosOffset", "X Position"],
+        ["yPosition/yPosSource", "yPosition/yPosMultiplier", "yPosition/yPosOffset", "Y Position"],
+        ["zPosition/zPosSource", "zPosition/zPosMultiplier", "zPosition/zPosOffset", "Z Position"],
+        ["xRotation/xRotSource", "xRotation/xRotMultiplier", "xRotation/xRotOffset", "X Rotation"],
+        ["yRotation/yRotSource", "yRotation/yRotMultiplier", "yRotation/yRotOffset", "Y Rotation"],
+        ["zRotation/zRotSource", "zRotation/zRotMultiplier", "zRotation/zRotOffset", "Z Rotation"],
+        ["xScale/xScaleSource", "xScale/xScaleMultiplier", "xScale/xScaleOffset", "X Scale"],
+        ["yScale/yScaleSource", "yScale/yScaleMultiplier", "yScale/yScaleOffset", "Y Scale"],
+    ];
+    debug_assert_eq!(names.len(), CD_PROPS.len());
+    for (i, n) in names.iter().enumerate() {
+        let rot = (3..6).contains(&i);
+        let scale = i >= 6;
+        let (lo, hi) = if rot { (-3600.0, 3600.0) } else { (-100.0, 100.0) };
+        v.push(p(n[0], "Source", Value::Enum(0), popup(CD_SOURCES)));
+        v.push(p(n[1], "Multiplier", num(0.0), slider(lo, hi, if rot { -360.0 } else { -10.0 }, if rot { 360.0 } else { 10.0 }, 2)));
+        v.push(p(n[2], "Offset", num(if scale { 1.0 } else { 0.0 }), slider(lo, hi, if rot { -360.0 } else { -10.0 }, if rot { 360.0 } else { 10.0 }, 2)));
+    }
+    v.extend(crate::card3d::camera_params(2.0));
+    v.extend(crate::card3d::lighting_params(1.0, 0.25));
+    v.extend(crate::card3d::material_params(0.75));
+    v
+}
+
+pub fn specs() -> Vec<EffectSpec> {
+    vec![
+        spec(
+            "ec.sim.ccballaction",
+            "CC Ball Action",
+            vec![
+                p("scatter", "Scatter", num(0.0), slider(0.0, 2000.0, 0.0, 300.0, 1)),
+                p("rotationAxis", "Rotation Axis", Value::Enum(0), popup(&["X Axis", "Y Axis", "Z Axis", "XY Axis", "XZ Axis", "YZ Axis", "XYZ Axis"])),
+                p("rotation", "Rotation", num(0.0), ParamUi::Angle),
+                p("twistProperty", "Twist Property", Value::Enum(0), popup(&["X Axis", "Y Axis", "Radius", "Brightness"])),
+                p("twistAngle", "Twist Angle", num(0.0), ParamUi::Angle),
+                p("gridSpacing", "Grid Spacing", num(4.0), slider(1.0, 200.0, 1.0, 50.0, 0)),
+                p("ballSize", "Ball Size", num(40.0), slider(0.0, 400.0, 0.0, 200.0, 1)),
+                p("instabilityState", "Instability State", num(0.0), ParamUi::Angle),
+            ],
+            ball_action,
+        ),
+        spec(
+            "ec.sim.ccpixelpolly",
+            "CC Pixel Polly",
+            vec![
+                p("force", "Force", num(100.0), slider(-1000.0, 1000.0, -300.0, 300.0, 1)),
+                p("gravity", "Gravity", num(1.0), slider(-20.0, 20.0, -5.0, 5.0, 2)),
+                p("spinning", "Spinning", num(0.0), ParamUi::Angle),
+                p("forceCenter", "Force Center", pt(0.5, 0.5), ParamUi::Point),
+                p("directionRandomness", "Direction Randomness", num(10.0), pct()),
+                p("speedRandomness", "Speed Randomness", num(10.0), pct()),
+                p("gridSpacing", "Grid Spacing", num(10.0), slider(1.0, 500.0, 2.0, 100.0, 0)),
+                p("object", "Object", Value::Enum(0), popup(&["Polygon", "Textured Polygon", "Square", "Textured Square"])),
+                p("enableDepthSort", "Enable Depth Sort", Value::Bool(true), ParamUi::Checkbox),
+                p("startTime", "Start Time (sec)", num(0.0), slider(-1000.0, 1000.0, 0.0, 10.0, 2)),
+            ],
+            pixel_polly,
+        ),
+        spec(
+            "ec.sim.ccscatterize",
+            "CC Scatterize",
+            vec![
+                p("scatter", "Scatter", num(0.0), slider(0.0, 1000.0, 0.0, 200.0, 1)),
+                p("rightTwist", "Right Twist", num(0.0), ParamUi::Angle),
+                p("leftTwist", "Left Twist", num(0.0), ParamUi::Angle),
+                p("transferMode", "Transfer Mode", Value::Enum(0), popup(&["Composite", "Add"])),
+            ],
+            scatterize,
+        ),
+        spec("ec.sim.carddance", "Card Dance", card_dance_params(), card_dance),
+        spec(
+            "ec.sim.caustics",
+            "Caustics",
+            vec![
+                p("bottom/bottom", "Bottom", Value::Layer(None), ParamUi::Layer),
+                p("bottom/scaling", "Scaling", num(1.0), slider(0.01, 10.0, 0.1, 3.0, 3)),
+                p("bottom/repeatMode", "Repeat Mode", Value::Enum(2), popup(&["Once", "Tiled", "Reflected"])),
+                p("bottom/bottomSizeDiffers", "If Layer Size Differs", Value::Enum(1), popup(&["Center", "Stretch to Fit"])),
+                p("bottom/blur", "Blur", num(0.0), slider(0.0, 100.0, 0.0, 20.0, 1)),
+                p("water/waterSurface", "Water Surface", Value::Layer(None), ParamUi::Layer),
+                p("water/waveHeight", "Wave Height", num(0.2), slider(-1.0, 1.0, -1.0, 1.0, 3)),
+                p("water/smoothing", "Smoothing", num(5.0), slider(0.0, 100.0, 0.0, 50.0, 1)),
+                p("water/waterDepth", "Water Depth", num(0.1), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("water/refractiveIndex", "Refractive Index", num(1.2), slider(1.0, 3.0, 1.0, 2.0, 3)),
+                p("water/surfaceColor", "Surface Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("water/surfaceOpacity", "Surface Opacity", num(0.3), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("water/causticsStrength", "Caustics Strength", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("sky/sky", "Sky", Value::Layer(None), ParamUi::Layer),
+                p("sky/scaling", "Scaling", num(1.0), slider(0.01, 10.0, 0.1, 3.0, 3)),
+                p("sky/repeatMode", "Repeat Mode", Value::Enum(2), popup(&["Once", "Tiled", "Reflected"])),
+                p("sky/skySizeDiffers", "If Layer Size Differs", Value::Enum(1), popup(&["Center", "Stretch to Fit"])),
+                p("sky/intensity", "Intensity", num(0.3), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("sky/convergence", "Convergence", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("lighting/lightType", "Light Type", Value::Enum(0), popup(&crate::card3d::LIGHT_TYPES)),
+                p("lighting/lightIntensity", "Light Intensity", num(1.0), slider(0.0, 4.0, 0.0, 2.0, 2)),
+                p("lighting/lightColor", "Light Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("lighting/lightPosition", "Light Position", pt(0.0, 0.0), ParamUi::Point),
+                p("lighting/lightHeight", "Light Height", num(1.0), slider(0.0, 10.0, 0.0, 4.0, 2)),
+                p("lighting/ambientLight", "Ambient Light", num(0.35), slider(0.0, 2.0, 0.0, 1.0, 2)),
+                p("material/diffuse", "Diffuse Reflection", num(0.75), slider(0.0, 2.0, 0.0, 1.0, 2)),
+                p("material/specular", "Specular Reflection", num(0.2), slider(0.0, 2.0, 0.0, 1.0, 2)),
+                p("material/highlightSharpness", "Highlight Sharpness", num(15.0), slider(1.0, 100.0, 1.0, 100.0, 1)),
+            ],
+            caustics,
+        ),
+        spec(
+            "ec.sim.waveworld",
+            "Wave World",
+            {
+                let mut v = vec![
+                    p("view", "View", Value::Enum(0), popup(&["Wireframe Preview", "Height Map"])),
+                    p("wireframeControls/horizontalRotation", "Horizontal Rotation", num(0.0), ParamUi::Angle),
+                    p("wireframeControls/verticalRotation", "Vertical Rotation", num(53.0), slider(0.0, 90.0, 0.0, 90.0, 1)),
+                    p("wireframeControls/verticalScale", "Vertical Scale", num(0.5), slider(0.0, 10.0, 0.0, 2.0, 3)),
+                    p("heightMapControls/brightness", "Brightness", num(0.5), slider(-1.0, 2.0, 0.0, 1.0, 3)),
+                    p("heightMapControls/contrast", "Contrast", num(0.75), slider(0.0, 4.0, 0.0, 2.0, 3)),
+                    p("heightMapControls/gamma", "Gamma Adjustment", num(1.0), slider(0.01, 10.0, 0.2, 5.0, 3)),
+                    p("heightMapControls/renderDryAreasAs", "Render Dry Areas As", Value::Enum(0), popup(&["Solid", "Transparent"])),
+                    p("heightMapControls/transparency", "Transparency", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                    p("simulation/gridResolution", "Grid Resolution", num(60.0), slider(1.0, 400.0, 1.0, 200.0, 0)),
+                    p("simulation/gridResDownsamples", "Grid Res Downsamples", Value::Bool(false), ParamUi::Checkbox),
+                    p("simulation/waveSpeed", "Wave Speed", num(0.2), slider(0.0, 5.0, 0.0, 1.0, 3)),
+                    p("simulation/damping", "Damping", num(0.05), slider(0.0, 5.0, 0.0, 1.0, 3)),
+                    p("simulation/reflectEdges", "Reflect Edges", Value::Enum(0), popup(&["None", "Left", "Top", "Right", "Bottom", "All"])),
+                    p("simulation/preRoll", "Pre-roll (seconds)", num(0.0), slider(0.0, 30.0, 0.0, 10.0, 2)),
+                    p("ground/ground", "Ground", Value::Layer(None), ParamUi::Layer),
+                    p("ground/steepness", "Steepness", num(0.25), slider(0.0, 2.0, 0.0, 1.0, 3)),
+                    p("ground/height", "Height", num(0.25), slider(0.0, 2.0, 0.0, 1.0, 3)),
+                    p("ground/waveStrength", "Wave Strength", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                ];
+                v.extend(producer_params(1, 0.5, (0.5, 0.5)));
+                v.extend(producer_params(2, 0.0, (0.25, 0.25)));
+                v
+            },
+            wave_world,
+        ),
+        spec(
+            "ec.sim.shatter",
+            "Shatter",
+            vec![
+                p(
+                    "view",
+                    "View",
+                    Value::Enum(1),
+                    popup(&["Rendered", "Wireframe Front View", "Wireframe", "Wireframe Front View + Forces", "Wireframe + Forces"]),
+                ),
+                p("render", "Render", Value::Enum(0), popup(&["All", "Layer", "Pieces"])),
+                p("shape/pattern", "Pattern", Value::Enum(0), popup(SHATTER_PATTERNS)),
+                p("shape/repetitions", "Repetitions", num(10.0), slider(1.0, 500.0, 1.0, 100.0, 2)),
+                p("shape/direction", "Direction", num(0.0), ParamUi::Angle),
+                p("shape/origin", "Origin", pt(0.5, 0.5), ParamUi::Point),
+                p("shape/customShatterMap", "Custom Shatter Map", Value::Layer(None), ParamUi::Layer),
+                p("shape/whiteTilesFixed", "White Tiles Fixed", Value::Bool(false), ParamUi::Checkbox),
+                p("shape/extrusionDepth", "Extrusion Depth", num(0.05), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("force1/force1Position", "Position", pt(0.5, 0.5), ParamUi::Point),
+                p("force1/force1Depth", "Depth", num(0.1), slider(-1.0, 1.0, -1.0, 1.0, 3)),
+                p("force1/force1Radius", "Radius", num(0.4), slider(0.0, 4.0, 0.0, 2.0, 3)),
+                p("force1/force1Strength", "Strength", num(5.0), slider(-20.0, 20.0, -10.0, 10.0, 2)),
+                p("force2/force2Position", "Position", pt(0.25, 0.25), ParamUi::Point),
+                p("force2/force2Depth", "Depth", num(0.1), slider(-1.0, 1.0, -1.0, 1.0, 3)),
+                p("force2/force2Radius", "Radius", num(0.0), slider(0.0, 4.0, 0.0, 2.0, 3)),
+                p("force2/force2Strength", "Strength", num(5.0), slider(-20.0, 20.0, -10.0, 10.0, 2)),
+                p("physics/rotationSpeed", "Rotation Speed", num(0.2), slider(0.0, 5.0, 0.0, 1.0, 3)),
+                p("physics/tumbleAxis", "Tumble Axis", Value::Enum(0), popup(&["Free", "None", "X", "Y", "Z", "XY", "XZ", "YZ"])),
+                p("physics/randomness", "Randomness", num(0.1), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("physics/viscosity", "Viscosity", num(0.1), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("physics/massVariance", "Mass Variance", num(30.0), pct()),
+                p("physics/gravity", "Gravity", num(3.0), slider(0.0, 100.0, 0.0, 10.0, 2)),
+                p("physics/gravityDirection", "Gravity Direction", num(180.0), ParamUi::Angle),
+                p("physics/gravityInclination", "Gravity Inclination", num(0.0), slider(-90.0, 90.0, -90.0, 90.0, 1)),
+                p("gradient/shatterThreshold", "Shatter Threshold", num(0.0), slider(0.0, 100.0, 0.0, 100.0, 1)),
+                p("gradient/gradientLayer", "Gradient Layer", Value::Layer(None), ParamUi::Layer),
+                p("gradient/invertGradient", "Invert Gradient", Value::Bool(false), ParamUi::Checkbox),
+                p("textures/color", "Color", col(1.0, 1.0, 1.0), ParamUi::Color),
+                p("textures/opacity", "Opacity", num(1.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("textures/frontMode", "Front Mode", Value::Enum(1), popup(&SHATTER_TEXTURE_MODES)),
+                p("textures/sideMode", "Side Mode", Value::Enum(0), popup(&SHATTER_TEXTURE_MODES)),
+                p("textures/backMode", "Back Mode", Value::Enum(1), popup(&SHATTER_TEXTURE_MODES)),
+                p("textures/frontLayer", "Front Layer", Value::Layer(None), ParamUi::Layer),
+                p("textures/sideLayer", "Side Layer", Value::Layer(None), ParamUi::Layer),
+                p("textures/backLayer", "Back Layer", Value::Layer(None), ParamUi::Layer),
+            ]
+            .into_iter()
+            .chain(crate::card3d::camera_params(4.0))
+            .chain(crate::card3d::lighting_params(1.0, 0.25))
+            .chain(crate::card3d::material_params(0.75))
+            .chain([p("randomSeed", "Random Seed", num(0.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0))])
+            .collect(),
+            shatter,
+        ),
+        spec(
+            "ec.sim.foam",
+            "Foam",
+            vec![
+                p("view", "View", Value::Enum(0), popup(&["Draft", "Draft + Flow Map", "Rendered"])),
+                p("producer/producerPoint", "Producer Point", pt(0.5, 0.5), ParamUi::Point),
+                p("producer/producerXSize", "Producer X Size", num(0.05), slider(0.0, 2.0, 0.0, 1.0, 3)),
+                p("producer/producerYSize", "Producer Y Size", num(0.05), slider(0.0, 2.0, 0.0, 1.0, 3)),
+                p("producer/producerOrientation", "Producer Orientation", num(0.0), ParamUi::Angle),
+                p("producer/zoomProducerPoint", "Zoom Producer Point", Value::Bool(false), ParamUi::Checkbox),
+                p("producer/productionRate", "Production Rate", num(1.0), slider(0.0, 50.0, 0.0, 10.0, 3)),
+                p("bubbles/size", "Size", num(0.5), slider(0.0, 10.0, 0.0, 2.0, 3)),
+                p("bubbles/sizeVariance", "Size Variance", num(0.5), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("bubbles/lifespan", "Lifespan", num(300.0), slider(1.0, 30_000.0, 1.0, 1000.0, 1)),
+                p("bubbles/growthSpeed", "Bubble Growth Speed", num(0.1), slider(0.0001, 10.0, 0.0001, 1.0, 3)),
+                p("bubbles/strength", "Strength", num(10.0), slider(0.0, 100.0, 0.0, 20.0, 2)),
+                p("physics/initialSpeed", "Initial Speed", num(0.0), slider(-100.0, 100.0, -10.0, 10.0, 3)),
+                p("physics/initialDirection", "Initial Direction", num(0.0), ParamUi::Angle),
+                p("physics/windSpeed", "Wind Speed", num(0.5), slider(-100.0, 100.0, -10.0, 10.0, 3)),
+                p("physics/windDirection", "Wind Direction", num(90.0), ParamUi::Angle),
+                p("physics/turbulence", "Turbulence", num(0.5), slider(0.0, 10.0, 0.0, 2.0, 3)),
+                p("physics/wobbleAmount", "Wobble Amount", num(0.05), slider(0.0, 10.0, 0.0, 2.0, 3)),
+                p("physics/repulsion", "Repulsion", num(1.0), slider(0.0, 10.0, 0.0, 2.0, 3)),
+                p("physics/popVelocity", "Pop Velocity", num(1.0), slider(-100.0, 100.0, -10.0, 10.0, 3)),
+                p("physics/viscosity", "Viscosity", num(0.1), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("physics/stickiness", "Stickiness", num(0.75), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("zoom", "Zoom", num(1.0), slider(0.01, 50.0, 0.1, 5.0, 3)),
+                p("universeSize", "Universe Size", num(1.0), slider(0.01, 10.0, 0.5, 3.0, 3)),
+                p("rendering/blendMode", "Blend Mode", Value::Enum(0), popup(&["Transparent", "Solid Old on Top", "Solid New on Top"])),
+                p("rendering/bubbleTexture", "Bubble Texture", Value::Enum(0), popup(&FOAM_TEXTURES)),
+                p("rendering/bubbleTextureLayer", "Bubble Texture Layer", Value::Layer(None), ParamUi::Layer),
+                p("rendering/bubbleOrientation", "Bubble Orientation", Value::Enum(0), popup(&["Fixed", "Physical Orientation", "Bubble Velocity"])),
+                p("rendering/environmentMap", "Environment Map", Value::Layer(None), ParamUi::Layer),
+                p("rendering/reflectionStrength", "Reflection Strength", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("rendering/reflectionConvergence", "Reflection Convergence", num(0.0), slider(0.0, 1.0, 0.0, 1.0, 3)),
+                p("flowMap/flowMap", "Flow Map", Value::Layer(None), ParamUi::Layer),
+                p("flowMap/flowMapSteepness", "Flow Map Steepness", num(0.05), slider(-100.0, 100.0, -1.0, 1.0, 3)),
+                p("flowMap/flowMapFits", "Flow Map Fits", Value::Enum(0), popup(&["Background", "Universe"])),
+                p("flowMap/simulationQuality", "Simulation Quality", Value::Enum(0), popup(&["Normal", "High", "Intense"])),
+                p("randomSeed", "Random Seed", num(1.0), slider(0.0, 10_000.0, 0.0, 1000.0, 0)),
+            ],
+            foam,
+        ),
+    ]
+}
diff --git a/crates/effects/src/sim2/shatter.rs b/crates/effects/src/sim2/shatter.rs
new file mode 100644
index 000000000..844fbb4b3
--- /dev/null
+++ b/crates/effects/src/sim2/shatter.rs
@@ -0,0 +1,484 @@
+use super::pieces::{M3, Piece, PiecePlan, PieceTex, inv3, rot_axis, rot_xyz, sort_far_first};
+use super::{
+    Acc, Buf, EffectCtx, Image, IndexedParallelIterator, IntoParallelIterator, IntoParallelRefIterator, Lighting, ParallelIterator, Post, Shape, Sprite,
+    SpritePlan, Value, h, hs, layer_or_self, unpremul,
+};
+
+// ------------------------------------------------------------------ Card Dance
+
+pub(super) const CD_SOURCES: &[&str] =
+    &["None", "Intensity 1", "Red 1", "Green 1", "Blue 1", "Alpha 1", "Intensity 2", "Red 2", "Green 2", "Blue 2", "Alpha 2"];
+
+/// (param id prefix, twirl-down group match id) per transformed card property.
+pub(super) const CD_PROPS: [(&str, &str); 8] = [
+    ("xPos", "xPosition"),
+    ("yPos", "yPosition"),
+    ("zPos", "zPosition"),
+    ("xRot", "xRotation"),
+    ("yRot", "yRotation"),
+    ("zRot", "zRotation"),
+    ("xScale", "xScale"),
+    ("yScale", "yScale"),
+];
+
+fn card_source(src: u32, g1: [f32; 4], g2: [f32; 4]) -> f32 {
+    let (c1, a1) = unpremul(g1);
+    let (c2, a2) = unpremul(g2);
+    let lum = |c: [f32; 3]| effectcraft_color::luminance(c[0], c[1], c[2]);
+    match src {
+        1 => lum(c1),
+        2 => c1[0],
+        3 => c1[1],
+        4 => c1[2],
+        5 => a1,
+        6 => lum(c2),
+        7 => c2[0],
+        8 => c2[1],
+        9 => c2[2],
+        10 => a2,
+        _ => 0.0,
+    }
+}
+
+pub(super) fn card_dance(ctx: &EffectCtx, b: Buf) -> Buf {
+    card_dance_plan(ctx, &b).finish(b)
+}
+
+pub(super) fn card_dance_plan(ctx: &EffectCtx, b: &Buf) -> PiecePlan {
+    let pr = ctx.params;
+    let rows = pr.f("rows").clamp(1.0, 1000.0) as u32;
+    let cols = if pr.e("rowsColumns") == 1 { rows } else { pr.f("columns").clamp(1.0, 1000.0) as u32 };
+    let g1 = layer_or_self(ctx, b, "gradientLayer1", true, true);
+    let g2 = layer_or_self(ctx, b, "gradientLayer2", true, true);
+    let back = ctx.layer_param("backLayer", true).map(|o| crate::util::fit_layer(ctx, b, &o, true));
+    let [lw, lh] = ctx.layer_size;
+    let s = b.scale;
+    let (cw, ch) = (lw / cols as f64, lh / rows as f64);
+    let cam = crate::card3d::projection(ctx, b);
+    let eye = cam.eye();
+    let light = Lighting::from(ctx, b);
+    let props: Vec<(u32, f64, f64)> =
+        CD_PROPS.iter().map(|(id, g)| (pr.e(&format!("{g}/{id}Source")), pr.f(&format!("{g}/{id}Multiplier")), pr.f(&format!("{g}/{id}Offset")))).collect();
+    let mut pieces: Vec<Piece> = (0..rows * cols)
+        .into_par_iter()
+        .filter_map(|i| {
+            let (cx0, cy0) = ((i % cols) as f64 * cw, (i / cols) as f64 * ch);
+            let c = [cx0 + cw * 0.5, cy0 + ch * 0.5];
+            let (bx, by) = (c[0] * s + b.offset[0], c[1] * s + b.offset[1]);
+            let (gp1, gp2) = (g1.sample_bilinear(bx, by), g2.sample_bilinear(bx, by));
+            let val = |k: usize| {
+                let (sr, m, o) = props[k];
+                o + m * card_source(sr, gp1, gp2) as f64
+            };
+            let (sx, sy) = (val(6), val(7));
+            let r = rot_xyz(val(3).to_radians(), val(4).to_radians(), val(5).to_radians());
+            let rs: M3 = std::array::from_fn(|k| [r[k][0] * sx, r[k][1] * sy, r[k][2]]);
+            let pos = [bx + val(0) * cw * s, by + val(1) * ch * s, val(2) * cw.max(ch) * s];
+            let (tx0, ty0) = ((cx0 * s + b.offset[0]) as f32, (cy0 * s + b.offset[1]) as f32);
+            let (tw, th) = ((cw * s) as f32, (ch * s) as f32);
+            let poly = [[tx0, ty0], [tx0 + tw, ty0], [tx0 + tw, ty0 + th], [tx0, ty0 + th]];
+            let mut pc = Piece::new(&poly, [bx as f32, by as f32], &rs, pos, cam)?;
+            pc.light(&light, &r, pos, eye);
+            Some(pc)
+        })
+        .collect();
+    sort_far_first(&mut pieces);
+    PiecePlan { pieces, front: PieceTex::Layer, back: back.map(PieceTex::Image) }
+}
+
+// ------------------------------------------------------------------ Shatter
+
+/// Shatter's Pattern options; the last, Custom, takes its pieces from Custom Shatter Map.
+pub(super) const SHATTER_PATTERNS: &[&str] = &["Bricks", "Glass", "Hexagons", "Squares", "Triangles", "Custom"];
+
+/// Pattern cells (polygons in pattern space, before rotation) covering `[x0, x1]×[y0, y1]`.
+fn pattern_cells(kind: u32, cell: f64, x0: f64, y0: f64, x1: f64, y1: f64, seed: u32) -> Vec<Vec<[f64; 2]>> {
+    let mut out = Vec::new();
+    let i0 = (x0 / cell).floor() as i64 - 1;
+    let i1 = (x1 / cell).ceil() as i64 + 1;
+    let j0 = (y0 / cell).floor() as i64 - 1;
+    let j1 = (y1 / cell).ceil() as i64 + 1;
+    match kind {
+        0 => {
+            let bh = cell * 0.5;
+            let r0 = (y0 / bh).floor() as i64 - 1;
+            let r1 = (y1 / bh).ceil() as i64 + 1;
+            for r in r0..=r1 {
+                let sh = if r.rem_euclid(2) == 1 { cell * 0.5 } else { 0.0 };
+                for i in i0..=i1 {
+                    let (x, y) = (i as f64 * cell + sh, r as f64 * bh);
+                    out.push(vec![[x, y], [x + cell, y], [x + cell, y + bh], [x, y + bh]]);
+                }
+            }
+        }
+        1 => {
+            // Jittered lattice split into triangles along a random diagonal.
+            let jit = |i: i64, j: i64| -> [f64; 2] {
+                let (a, b) = (i as u32, j as u32);
+                [i as f64 * cell + hs(a, b.wrapping_add(17), seed) as f64 * cell * 0.35, j as f64 * cell + hs(a, b.wrapping_add(91), seed) as f64 * cell * 0.35]
+            };
+            for j in j0..=j1 {
+                for i in i0..=i1 {
+                    let (p00, p10, p11, p01) = (jit(i, j), jit(i + 1, j), jit(i + 1, j + 1), jit(i, j + 1));
+                    if h(i as u32, j as u32, seed ^ 0x55) < 0.5 {
+                        out.push(vec![p00, p10, p11]);
+                        out.push(vec![p00, p11, p01]);
+                    } else {
+                        out.push(vec![p00, p10, p01]);
+                        out.push(vec![p10, p11, p01]);
+                    }
+                }
+            }
+        }
+        2 => {
+            let r = cell / 3f64.sqrt();
+            let dx = 1.5 * r;
+            let dy = 3f64.sqrt() * r;
+            let c0 = (x0 / dx).floor() as i64 - 1;
+            let c1 = (x1 / dx).ceil() as i64 + 1;
+            let rr0 = (y0 / dy).floor() as i64 - 1;
+            let rr1 = (y1 / dy).ceil() as i64 + 1;
+            for ci in c0..=c1 {
+                for rj in rr0..=rr1 {
+                    let cx = ci as f64 * dx;
+                    let cy = (rj as f64 + if ci.rem_euclid(2) == 1 { 0.5 } else { 0.0 }) * dy;
+                    out.push(
+                        (0..6)
+                            .map(|k| {
+                                let a = k as f64 * std::f64::consts::PI / 3.0;
+                                [cx + r * a.cos(), cy + r * a.sin()]
+                            })
+                            .collect(),
+                    );
+                }
+            }
+        }
+        3 => {
+            for j in j0..=j1 {
+                for i in i0..=i1 {
+                    let (x, y) = (i as f64 * cell, j as f64 * cell);
+                    out.push(vec![[x, y], [x + cell, y], [x + cell, y + cell], [x, y + cell]]);
+                }
+            }
+        }
+        _ => {
+            for j in j0..=j1 {
+                for i in i0..=i1 {
+                    let (x, y) = (i as f64 * cell, j as f64 * cell);
+                    if (i + j).rem_euclid(2) == 0 {
+                        out.push(vec![[x, y], [x + cell, y], [x, y + cell]]);
+                        out.push(vec![[x + cell, y], [x + cell, y + cell], [x, y + cell]]);
+                    } else {
+                        out.push(vec![[x, y], [x + cell, y], [x + cell, y + cell]]);
+                        out.push(vec![[x, y], [x + cell, y + cell], [x, y + cell]]);
+                    }
+                }
+            }
+        }
+    }
+    out
+}
+
+/// `∫0^t e^{-ks} ds` and `∫0^t ∫0^u e^{-ks} ds du` (drag-damped ballistic factors).
+fn drag_factors(k: f64, t: f64) -> (f64, f64) {
+    if k < 1e-6 {
+        (t, 0.5 * t * t)
+    } else {
+        let e = (-k * t).exp();
+        ((1.0 - e) / k, t / k - (1.0 - e) / (k * k))
+    }
+}
+
+/// Shatter's Front / Side / Back Mode options.
+pub(super) const SHATTER_TEXTURE_MODES: [&str; 3] = ["Color", "Layer", "Tinted Layer"];
+
+/// One face's texture: a flat colour, a layer, or a layer tinted by the Textures colour.
+struct Face {
+    mode: u32,
+    img: Option<Image>,
+}
+
+impl Face {
+    fn from(ctx: &EffectCtx, b: &Buf, mode: &str, layer: &str, default_mode: u32) -> Face {
+        let mode = ctx.params.get(mode).map(|v| v.as_enum()).unwrap_or(default_mode);
+        // A face layer of None is the effect's own layer.
+        let img = (mode != 0).then(|| layer_or_self(ctx, b, layer, true, true));
+        Face { mode, img }
+    }
+}
+
+/// Group key of a Custom Shatter Map colour (pieces of one colour break as one).
+fn map_key(c: [f32; 4]) -> u32 {
+    let (c, a) = unpremul(c);
+    if a < 0.5 {
+        return u32::MAX;
+    }
+    let q = |v: f32| ((v.clamp(0.0, 1.0) * 15.0).round() as u32) & 15;
+    q(c[0]) << 8 | q(c[1]) << 4 | q(c[2])
+}
+
+pub(super) fn shatter(ctx: &EffectCtx, b: Buf) -> Buf {
+    match shatter_impl(ctx, &b) {
+        ShatterPlan::Pieces(plan) => plan.finish(b),
+        ShatterPlan::Wire(plan) => plan.finish(b),
+    }
+}
+
+/// What Shatter draws: the pieces (Rendered view) or the wireframe lines.
+pub(super) enum ShatterPlan {
+    Pieces(PiecePlan),
+    Wire(SpritePlan),
+}
+
+pub(super) fn shatter_impl(ctx: &EffectCtx, b: &Buf) -> ShatterPlan {
+    let pr = ctx.params;
+    let view = pr.e("view");
+    let render = pr.e("render");
+    let kind = pr.e("shape/pattern");
+    let custom = kind as usize == SHATTER_PATTERNS.len() - 1;
+    let reps = pr.f("shape/repetitions").clamp(1.0, 500.0);
+    let dir = pr.f("shape/direction").to_radians();
+    let origin = pr.v2("shape/origin");
+    let forces = [
+        (pr.v2("force1/force1Position"), pr.f("force1/force1Depth"), pr.f("force1/force1Radius"), pr.f("force1/force1Strength")),
+        (pr.v2("force2/force2Position"), pr.f("force2/force2Depth"), pr.f("force2/force2Radius"), pr.f("force2/force2Strength")),
+    ];
+    let rot_speed = pr.f("physics/rotationSpeed");
+    let tumble = pr.e("physics/tumbleAxis");
+    let randomness = pr.f("physics/randomness");
+    let k = pr.f("physics/viscosity").max(0.0) * 5.0;
+    let mass_var = pr.f("physics/massVariance") / 100.0;
+    let gravity = pr.f("physics/gravity");
+    let gdir = pr.f("physics/gravityDirection").to_radians();
+    let ginc = pr.f("physics/gravityInclination").to_radians();
+    let seed = (pr.f("randomSeed") as u32).wrapping_mul(0x9e3779b1) ^ ctx.seed;
+    let [lw, lh] = ctx.layer_size;
+    let s = b.scale;
+    let t = ctx.time.max(0.0);
+    let unit = lw * 0.1;
+    let cell = lw / reps;
+    let extrude = pr.f("shape/extrusionDepth").max(0.0) * cell * s;
+    let cam = crate::card3d::projection(ctx, b);
+    let eye = cam.eye();
+    let light = Lighting::from(ctx, b);
+    // Gradient: with a gradient layer only pieces at least as bright as 1 − Shatter Threshold
+    // (Invert Gradient: as dark) break.
+    let gradient = ctx.layer_param("gradient/gradientLayer", true).map(|o| crate::util::fit_layer(ctx, b, &o, true));
+    let threshold = pr.get("gradient/shatterThreshold").map(Value::as_f64).unwrap_or(0.0) / 100.0;
+    let invert_gradient = pr.b("gradient/invertGradient");
+    // Textures.
+    let tex_color = pr.get("textures/color").map(|v| v.as_color()).unwrap_or([1.0; 4]);
+    let tex_opacity = pr.get("textures/opacity").map(Value::as_f64).unwrap_or(1.0).clamp(0.0, 1.0) as f32;
+    let front = Face::from(ctx, b, "textures/frontMode", "textures/frontLayer", 1);
+    let side = Face::from(ctx, b, "textures/sideMode", "textures/sideLayer", 0);
+    let backf = Face::from(ctx, b, "textures/backMode", "textures/backLayer", 1);
+    let custom_map = custom.then(|| layer_or_self(ctx, b, "shape/customShatterMap", true, true));
+    let white_fixed = pr.b("shape/whiteTilesFixed");
+    let (sd, cd) = dir.sin_cos();
+    let to_layer = |q: [f64; 2]| [origin[0] + q[0] * cd - q[1] * sd, origin[1] + q[0] * sd + q[1] * cd];
+    // Pattern-space bounds of the layer rectangle.
+    let corners = [[0.0, 0.0], [lw, 0.0], [lw, lh], [0.0, lh]].map(|c: [f64; 2]| {
+        let (dx, dy) = (c[0] - origin[0], c[1] - origin[1]);
+        [dx * cd + dy * sd, -dx * sd + dy * cd]
+    });
+    let (px0, px1) = (corners.iter().map(|c| c[0]).fold(f64::INFINITY, f64::min), corners.iter().map(|c| c[0]).fold(f64::NEG_INFINITY, f64::max));
+    let (py0, py1) = (corners.iter().map(|c| c[1]).fold(f64::INFINITY, f64::min), corners.iter().map(|c| c[1]).fold(f64::NEG_INFINITY, f64::max));
+    // Custom Shatter Map: square cells grouped by the map's colour.
+    let cells = pattern_cells(if custom { 3 } else { kind }, cell, px0, py0, px1, py1, seed);
+    let polys: Vec<Vec<[f64; 2]>> = cells.iter().map(|poly| poly.iter().map(|&q| to_layer(q)).collect()).collect();
+    let centre = |lp: &[[f64; 2]]| [lp.iter().map(|v| v[0]).sum::<f64>() / lp.len() as f64, lp.iter().map(|v| v[1]).sum::<f64>() / lp.len() as f64];
+    let keys: Vec<u32> = match &custom_map {
+        Some(m) => polys
+            .iter()
+            .map(|lp| {
+                let c = centre(lp);
+                map_key(m.sample_bilinear(c[0] * s + b.offset[0], c[1] * s + b.offset[1]))
+            })
+            .collect(),
+        None => (0..polys.len() as u32).collect(),
+    };
+    // Group centres (custom map) — each group moves as one rigid piece.
+    let mut groups: std::collections::HashMap<u32, ([f64; 2], f64)> = std::collections::HashMap::new();
+    for (lp, &key) in polys.iter().zip(&keys) {
+        let c = centre(lp);
+        let e = groups.entry(key).or_insert(([0.0; 2], 0.0));
+        e.0[0] += c[0];
+        e.0[1] += c[1];
+        e.1 += 1.0;
+    }
+    let g3 = [gdir.sin() * ginc.cos() * gravity * unit, -gdir.cos() * ginc.cos() * gravity * unit, ginc.sin() * gravity * unit];
+    let mut pieces: Vec<Piece> = polys
+        .par_iter()
+        .zip(keys.par_iter())
+        .flat_map_iter(|(lp, &key)| {
+            let mut out: Vec<Piece> = vec![];
+            let (mnx, mxx) = (lp.iter().map(|v| v[0]).fold(f64::INFINITY, f64::min), lp.iter().map(|v| v[0]).fold(f64::NEG_INFINITY, f64::max));
+            let (mny, mxy) = (lp.iter().map(|v| v[1]).fold(f64::INFINITY, f64::min), lp.iter().map(|v| v[1]).fold(f64::NEG_INFINITY, f64::max));
+            if mxx < 0.0 || mxy < 0.0 || mnx > lw || mny > lh || key == u32::MAX {
+                return out.into_iter();
+            }
+            let pc_c = centre(lp);
+            let (gsum, gn) = groups[&key];
+            let gc = [gsum[0] / gn, gsum[1] / gn];
+            let i = key;
+            // Broken when inside a force sphere (centred `depth` in front of the layer).
+            let mut v = [0.0f64; 3];
+            let mut broken = false;
+            for (fp, fd, fr, fs) in forces {
+                let rad = fr * lw;
+                if rad <= 0.0 {
+                    continue;
+                }
+                let dv = [gc[0] - fp[0], gc[1] - fp[1], fd * lw];
+                let dist = (dv[0] * dv[0] + dv[1] * dv[1] + dv[2] * dv[2]).sqrt();
+                if dist < rad {
+                    broken = true;
+                    let f = fs * (1.0 - dist / rad) * unit / dist.max(1e-6);
+                    for q in 0..3 {
+                        v[q] += dv[q] * f;
+                    }
+                }
+            }
+            if broken && let Some(g) = &gradient {
+                let (c, _) = unpremul(g.sample_bilinear(gc[0] * s + b.offset[0], gc[1] * s + b.offset[1]));
+                let mut l = effectcraft_color::luminance(c[0], c[1], c[2]).clamp(0.0, 1.0) as f64;
+                if invert_gradient {
+                    l = 1.0 - l;
+                }
+                broken = threshold > 0.0 && l >= 1.0 - threshold;
+            }
+            if broken && custom && white_fixed && key == 0xfff {
+                broken = false;
+            }
+            if (broken && render == 1) || (!broken && render == 2) {
+                return out.into_iter();
+            }
+            let mut gpos = [gc[0], gc[1], 0.0];
+            let mut r = rot_axis([1.0, 0.0, 0.0], 0.0);
+            let moving = broken && t > 0.0;
+            if moving {
+                let mass = 1.0 + mass_var * hs(i, 1, seed) as f64;
+                for q in 0..3 {
+                    v[q] = v[q] / mass + randomness * unit * hs(i, 2 + q as u32, seed) as f64 * 2.0;
+                }
+                let (f1, f2) = drag_factors(k, t);
+                for q in 0..3 {
+                    gpos[q] += v[q] * f1 + g3[q] * f2;
+                }
+                let axis = match tumble {
+                    1 => [0.0, 0.0, 0.0],
+                    2 => [1.0, 0.0, 0.0],
+                    3 => [0.0, 1.0, 0.0],
+                    4 => [0.0, 0.0, 1.0],
+                    5 => [hs(i, 6, seed) as f64, hs(i, 7, seed) as f64, 0.0],
+                    6 => [hs(i, 6, seed) as f64, 0.0, hs(i, 8, seed) as f64],
+                    7 => [0.0, hs(i, 7, seed) as f64, hs(i, 8, seed) as f64],
+                    _ => [hs(i, 6, seed) as f64, hs(i, 7, seed) as f64, hs(i, 8, seed) as f64],
+                };
+                let speed = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt() / unit;
+                let omega = rot_speed * std::f64::consts::TAU * (0.5 + h(i, 9, seed) as f64) * speed.min(10.0);
+                r = rot_axis(axis, omega * f1);
+            }
+            // The piece's centre: its offset from the group centre, rotated with the group.
+            let off = [pc_c[0] - gc[0], pc_c[1] - gc[1], 0.0];
+            let pos: [f64; 3] = std::array::from_fn(|q| gpos[q] + (0..3).map(|k| r[q][k] * off[k]).sum::<f64>());
+            let tex: Vec<[f32; 2]> = lp.iter().map(|v| [(v[0] * s + b.offset[0]) as f32, (v[1] * s + b.offset[1]) as f32]).collect();
+            let c0 = [(pc_c[0] * s + b.offset[0]) as f32, (pc_c[1] * s + b.offset[1]) as f32];
+            let posb = [pos[0] * s + b.offset[0], pos[1] * s + b.offset[1], pos[2] * s];
+            let Some(mut pc) = Piece::new(&tex, c0, &r, posb, cam) else { return out.into_iter() };
+            pc.light(&light, &r, posb, eye);
+            pc.alpha = tex_opacity;
+            let face = if pc.back { &backf } else { &front };
+            if face.mode == 0 {
+                pc.flat = Some([tex_color[0], tex_color[1], tex_color[2]]);
+            } else if face.mode == 2 {
+                pc.tint = std::array::from_fn(|q| pc.tint[q] * tex_color[q]);
+            }
+            // Extrusion: the sides of a moving piece, from its front outline back by the depth.
+            if moving && extrude > 0.0 {
+                let nb = [r[0][2], r[1][2], r[2][2]];
+                let n = tex.len();
+                for e in 0..n {
+                    let (a, bv) = (tex[e], tex[(e + 1) % n]);
+                    let ed = [(bv[0] - a[0]) as f64, (bv[1] - a[1]) as f64];
+                    let len = (ed[0] * ed[0] + ed[1] * ed[1]).sqrt();
+                    if len < 1e-6 {
+                        continue;
+                    }
+                    let ew: [f64; 3] = std::array::from_fn(|q| (r[q][0] * ed[0] + r[q][1] * ed[1]) / len);
+                    let third = [ew[1] * nb[2] - ew[2] * nb[1], ew[2] * nb[0] - ew[0] * nb[2], ew[0] * nb[1] - ew[1] * nb[0]];
+                    let rs: M3 = std::array::from_fn(|q| [ew[q], nb[q], third[q]]);
+                    // Side centre in world: edge midpoint (world) plus half the depth backwards.
+                    let mid = [((a[0] + bv[0]) * 0.5 - c0[0]) as f64, ((a[1] + bv[1]) * 0.5 - c0[1]) as f64];
+                    let mw: [f64; 3] = std::array::from_fn(|q| posb[q] + r[q][0] * mid[0] + r[q][1] * mid[1] + nb[q] * extrude * 0.5);
+                    let (hl, hd) = ((len * 0.5) as f32, (extrude * 0.5) as f32);
+                    let cs = [(a[0] + bv[0]) * 0.5, (a[1] + bv[1]) * 0.5];
+                    let quad = [[cs[0] - hl, cs[1] - hd], [cs[0] + hl, cs[1] - hd], [cs[0] + hl, cs[1] + hd], [cs[0] - hl, cs[1] + hd]];
+                    if let Some(mut sp) = Piece::new(&quad, cs, &rs, mw, cam) {
+                        sp.light(&light, &rs, mw, eye);
+                        sp.alpha = tex_opacity;
+                        let colour = match (&side.img, side.mode) {
+                            (Some(img), m) if m != 0 => {
+                                let (c, _) = unpremul(img.sample_bilinear(cs[0] as f64, cs[1] as f64));
+                                if m == 2 { std::array::from_fn(|q| c[q] * tex_color[q]) } else { c }
+                            }
+                            _ => [tex_color[0], tex_color[1], tex_color[2]],
+                        };
+                        sp.flat = Some(colour);
+                        out.push(sp);
+                    }
+                }
+            }
+            out.push(pc);
+            out.into_iter()
+        })
+        .collect();
+    sort_far_first(&mut pieces);
+    if view == 0 {
+        let tex = |i: &Option<Image>| i.clone().map(PieceTex::Image);
+        let front_t = tex(&front.img).unwrap_or(PieceTex::Layer);
+        let back_t = tex(&backf.img).unwrap_or_else(|| front_t.clone());
+        return ShatterPlan::Pieces(PiecePlan { pieces, front: front_t, back: Some(back_t) });
+    }
+    {
+        // Wireframes: piece outlines (front view: at rest; otherwise animated), plus forces.
+        let animated = view == 2 || view == 4;
+        let mut lines = Vec::new();
+        for pc in &pieces {
+            let n = pc.n as usize;
+            let pts: Vec<[f32; 2]> = if animated {
+                let fw = inv3(&pc.inv);
+                match fw {
+                    Some(m) => pc.poly[..n]
+                        .iter()
+                        .map(|v| {
+                            let (a, bb) = ((v[0] - pc.c0[0]) as f64, (v[1] - pc.c0[1]) as f64);
+                            let w = m[2][0] * a + m[2][1] * bb + m[2][2];
+                            [((m[0][0] * a + m[0][1] * bb + m[0][2]) / w) as f32, ((m[1][0] * a + m[1][1] * bb + m[1][2]) / w) as f32]
+                        })
+                        .collect(),
+                    None => continue,
+                }
+            } else {
+                pc.poly[..n].to_vec()
+            };
+            for e in 0..n {
+                let (a, c) = (pts[e], pts[(e + 1) % n]);
+                lines.push(Sprite::new(a[0], a[1], 0.5, [0.75, 0.85, 1.0, 1.0], Shape::Line { dx: c[0] - a[0], dy: c[1] - a[1] }));
+            }
+        }
+        if view >= 3 {
+            for (fp, _, fr, _) in forces {
+                let (fx, fy) = b.to_px(fp);
+                let rad = fr * lw * s;
+                for k in 0..64 {
+                    let (a0, a1) = (k as f64 / 64.0 * std::f64::consts::TAU, (k + 1) as f64 / 64.0 * std::f64::consts::TAU);
+                    let (x0, y0) = (fx + rad * a0.cos(), fy + rad * a0.sin());
+                    let (x1, y1) = (fx + rad * a1.cos(), fy + rad * a1.sin());
+                    lines.push(Sprite::new(x0 as f32, y0 as f32, 0.5, [1.0, 0.3, 0.3, 1.0], Shape::Line { dx: (x1 - x0) as f32, dy: (y1 - y0) as f32 }));
+                }
+            }
+        }
+        ShatterPlan::Wire(SpritePlan { sprites: lines, tints: vec![], acc: Acc::Over, post: Post::Replace })
+    }
+}
diff --git a/crates/effects/src/sim2/surfaces.rs b/crates/effects/src/sim2/surfaces.rs
new file mode 100644
index 000000000..7c3c032f0
--- /dev/null
+++ b/crates/effects/src/sim2/surfaces.rs
@@ -0,0 +1,524 @@
+use super::{Acc, Buf, EffectCtx, Image, IntoParallelIterator, ParallelIterator, Plane, Px, Shape, SimCache, Sprite, Value, gauss_plane, params_key, unpremul};
+
+// ------------------------------------------------------------------ Caustics
+
+/// Sample with repeat mode: 0 Once (transparent outside), 1 Tiled, 2 Reflected.
+fn sample_repeat(img: &Image, x: f64, y: f64, mode: u32) -> Px {
+    let (w, hh) = (img.width as f64, img.height as f64);
+    match mode {
+        1 => img.sample_bilinear_clamped(x.rem_euclid(w), y.rem_euclid(hh)),
+        2 => {
+            let m = |v: f64, n: f64| {
+                let r = v.rem_euclid(2.0 * n);
+                if r > n { 2.0 * n - r } else { r }
+            };
+            img.sample_bilinear_clamped(m(x, w), m(y, hh))
+        }
+        _ => img.sample_bilinear(x, y),
+    }
+}
+
+/// Everything Caustics' per-pixel pass needs, prepared on the CPU (the other layers it reads
+/// and the parameter conversions); the layer's own pixels are not read.
+pub struct CausticsSetup {
+    /// The Bottom layer fitted to the buffer, `None` = the layer itself.
+    pub bottom: Option<Image>,
+    /// Gaussian σ (buffer px) blurring the bottom (transparent edges), 0 = none.
+    pub bottom_sigma: f64,
+    /// The water surface's height field (smoothed luminance), `None` = flat.
+    pub height: Option<Plane>,
+    /// The Sky layer fitted to the buffer.
+    pub sky: Option<Image>,
+    pub scaling: f64,
+    pub repeat: u32,
+    pub wave_h: f64,
+    /// Displacement per unit of height gradient.
+    pub k: f64,
+    /// Layer centre (buffer px).
+    pub cx: f64,
+    pub cy: f64,
+    /// Layer width (buffer px).
+    pub lw: f64,
+    pub surf: [f32; 4],
+    pub surf_op: f32,
+    pub cstr: f32,
+    pub lc: [f32; 4],
+    pub li: f32,
+    /// Light position (buffer px) and height (layer widths); `point` = from the position to
+    /// each pixel, else one direction from above the layer centre.
+    pub lx: f64,
+    pub ly: f64,
+    pub lheight: f64,
+    pub point: bool,
+    pub ambient: f32,
+    pub diffuse: f32,
+    pub specular: f32,
+    pub sharp: f32,
+    pub sky_scaling: f64,
+    pub sky_repeat: u32,
+    pub sky_int: f32,
+    pub convergence: f64,
+}
+
+/// Caustics' setup for layer geometry `b` (see [`CausticsSetup`]).
+pub fn caustics_setup(ctx: &EffectCtx, b: &Buf) -> CausticsSetup {
+    let pr = ctx.params;
+    let s = b.scale;
+    let bottom = ctx.layer_param("bottom/bottom", true).map(|o| crate::util::fit_layer(ctx, b, &o, pr.e("bottom/bottomSizeDiffers") == 1));
+    let blur = pr.f("bottom/blur") * s;
+    let wave_h = pr.f("water/waveHeight");
+    let smoothing = pr.f("water/smoothing") * s;
+    let depth = pr.f("water/waterDepth");
+    let ior = pr.f("water/refractiveIndex").max(1.0);
+    let lpos = pr.v2("lighting/lightPosition");
+    // Height field of the water surface (luminance of the chosen layer; none = flat).
+    let height = ctx.layer_param("water/waterSurface", true).map(|o| {
+        let img = crate::util::fit_layer(ctx, b, &o, true);
+        let pl = Plane::luma(&img);
+        if smoothing > 0.05 { gauss_plane(&pl, smoothing * 0.5, smoothing * 0.5) } else { pl }
+    });
+    let lw = ctx.layer_size[0] * s;
+    let k = wave_h * depth * (1.0 - 1.0 / ior) * lw * 2.0;
+    let (cx, cy) = (b.offset[0] + ctx.layer_size[0] * 0.5 * s, b.offset[1] + ctx.layer_size[1] * 0.5 * s);
+    let (lx, ly) = b.to_px(lpos);
+    let (lc, li, lheight) = (pr.color("lighting/lightColor"), pr.f("lighting/lightIntensity") as f32, pr.f("lighting/lightHeight").max(0.01));
+    // Light Type: Distant Source (one direction, from the light position above the layer
+    // centre), Point Source (from the light position to each pixel) or First Comp Light.
+    let light_type = pr.e("lighting/lightType");
+    let comp_light = if light_type == 2 { ctx.env.host.and_then(|h| h.comp_scene()).and_then(|sc| sc.light) } else { None };
+    let (lc, li, lx, ly, lheight, point) = match (light_type, comp_light) {
+        (2, Some(l)) => {
+            let c = [l.color[0], l.color[1], l.color[2], 1.0];
+            // Comp space: z away from the viewer; the light above the water is at −z.
+            let (px, py) = (l.pos[0] * s + b.offset[0], l.pos[1] * s + b.offset[1]);
+            (c, li, px, py, (-l.pos[2] / ctx.layer_size[0].max(1.0)).max(0.01), l.kind == 1)
+        }
+        (2, None) => (lc, 0.0, lx, ly, lheight, false),
+        (1, _) => (lc, li, lx, ly, lheight, true),
+        _ => (lc, li, lx, ly, lheight, false),
+    };
+    // Sky: the layer the water surface reflects (Surface Opacity 1 = a mirror of it).
+    let sky = ctx.layer_param("sky/sky", true).map(|o| crate::util::fit_layer(ctx, b, &o, pr.e("sky/skySizeDiffers") == 1));
+    CausticsSetup {
+        bottom,
+        bottom_sigma: if blur > 0.05 { blur * 0.5 } else { 0.0 },
+        height,
+        sky,
+        scaling: pr.f("bottom/scaling").max(0.01),
+        repeat: pr.e("bottom/repeatMode"),
+        wave_h,
+        k,
+        cx,
+        cy,
+        lw,
+        surf: pr.color("water/surfaceColor"),
+        surf_op: pr.f("water/surfaceOpacity") as f32,
+        cstr: pr.f("water/causticsStrength") as f32,
+        lc,
+        li,
+        lx,
+        ly,
+        lheight,
+        point,
+        ambient: pr.f("lighting/ambientLight") as f32,
+        diffuse: pr.f("material/diffuse") as f32,
+        specular: pr.f("material/specular") as f32,
+        sharp: pr.f("material/highlightSharpness").max(1.0) as f32,
+        sky_scaling: pr.get("sky/scaling").map(Value::as_f64).unwrap_or(1.0).max(0.01),
+        sky_repeat: pr.e("sky/repeatMode"),
+        sky_int: pr.get("sky/intensity").map(Value::as_f64).unwrap_or(0.3) as f32,
+        convergence: pr.get("sky/convergence").map(Value::as_f64).unwrap_or(0.5).clamp(0.0, 1.0),
+    }
+}
+
+pub(super) fn caustics(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    let st = caustics_setup(ctx, &b);
+    let mut bottom = st.bottom.clone().unwrap_or_else(|| b.img.clone());
+    if st.bottom_sigma > 0.0 {
+        bottom = effectcraft_raster::gaussian_blur(&bottom, st.bottom_sigma, st.bottom_sigma, false);
+    }
+    let CausticsSetup {
+        scaling,
+        repeat,
+        wave_h,
+        k,
+        cx,
+        cy,
+        lw,
+        surf,
+        surf_op,
+        cstr,
+        lc,
+        li,
+        lx,
+        ly,
+        lheight,
+        point,
+        ambient,
+        diffuse,
+        specular,
+        sharp,
+        sky_scaling,
+        sky_repeat,
+        sky_int,
+        convergence,
+        ..
+    } = st;
+    let (height, sky) = (&st.height, &st.sky);
+    let (w, hh) = (b.img.width as usize, b.img.height as usize);
+    let norm3 = |v: [f64; 3]| {
+        let n = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt().max(1e-12);
+        [(v[0] / n) as f32, (v[1] / n) as f32, (v[2] / n) as f32]
+    };
+    let lv_at = |x: f64, y: f64| {
+        if point {
+            norm3([(lx - x) / lw.max(1.0), (ly - y) / lw.max(1.0), lheight])
+        } else {
+            norm3([(lx - cx) / lw.max(1.0), (ly - cy) / lw.max(1.0), lheight])
+        }
+    };
+    let grad = |x: usize, y: usize| -> (f64, f64) {
+        match height {
+            Some(pl) => {
+                let gx = (pl.get_clamped(x as i64 + 1, y as i64) - pl.get_clamped(x as i64 - 1, y as i64)) as f64 * 0.5;
+                let gy = (pl.get_clamped(x as i64, y as i64 + 1) - pl.get_clamped(x as i64, y as i64 - 1)) as f64 * 0.5;
+                (gx, gy)
+            }
+            None => (0.0, 0.0),
+        }
+    };
+    // Displacement and its Jacobian (caustic focusing) per pixel.
+    let disp: Vec<(f64, f64)> = (0..w * hh)
+        .into_par_iter()
+        .map(|i| {
+            let (gx, gy) = grad(i % w, i / w);
+            (-gx * k, -gy * k)
+        })
+        .collect();
+    b.img.rows_mut().for_each(|(y, row)| {
+        for (x, px) in row.iter_mut().enumerate() {
+            let i = y * w + x;
+            let (dx, dy) = disp[i];
+            let d = |xx: usize, yy: usize| disp[yy.min(hh - 1) * w + xx.min(w - 1)];
+            let (dxr, _) = d(x + 1, y);
+            let (_, dyd) = d(x, y + 1);
+            let (dxl, _) = d(x.saturating_sub(1), y);
+            let (_, dyu) = d(x, y.saturating_sub(1));
+            let jac = (1.0 + (dxr - dxl) * 0.5) * (1.0 + (dyd - dyu) * 0.5);
+            let focus = ((1.0 / jac.abs().max(0.2)) as f32 - 1.0).clamp(-1.0, 4.0);
+            let sx = cx + (x as f64 + 0.5 + dx - cx) / scaling;
+            let sy = cy + (y as f64 + 0.5 + dy - cy) / scaling;
+            let p = sample_repeat(&bottom, sx, sy, repeat);
+            let (c, a) = unpremul(p);
+            let (gx, gy) = grad(x, y);
+            let n = {
+                let v = [-gx * wave_h * 20.0, -gy * wave_h * 20.0, 1.0];
+                let m = (v[0] * v[0] + v[1] * v[1] + 1.0).sqrt();
+                [(v[0] / m) as f32, (v[1] / m) as f32, (v[2] / m) as f32]
+            };
+            let lv = lv_at(x as f64 + 0.5, y as f64 + 0.5);
+            let nl = (n[0] * lv[0] + n[1] * lv[1] + n[2] * lv[2]).max(0.0);
+            let hv = {
+                let v = [lv[0], lv[1], lv[2] + 1.0];
+                let m = (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]).sqrt();
+                [v[0] / m, v[1] / m, v[2] / m]
+            };
+            let spec = (n[0] * hv[0] + n[1] * hv[1] + n[2] * hv[2]).max(0.0).powf(sharp) * specular * li;
+            let light = ambient + diffuse * li * nl + cstr * focus * li;
+            // The surface: its colour lit like the water, or the sky it reflects (sampled along
+            // the surface normal; Convergence pulls the reflection towards the pixel itself).
+            let surface: [f32; 3] = match &sky {
+                Some(sk) => {
+                    let reach = (1.0 - convergence) * lw * 0.5;
+                    let (rx, ry) = (x as f64 + 0.5 + n[0] as f64 * reach, y as f64 + 0.5 + n[1] as f64 * reach);
+                    let (rx, ry) = (cx + (rx - cx) / sky_scaling, cy + (ry - cy) / sky_scaling);
+                    let (sc, _) = unpremul(sample_repeat(sk, rx, ry, sky_repeat));
+                    std::array::from_fn(|q| sc[q] * sky_int * 3.0 * surf[q])
+                }
+                None => std::array::from_fn(|q| surf[q] * (ambient + diffuse * li * nl)),
+            };
+            let cc: [f32; 3] = std::array::from_fn(|q| {
+                let base = c[q] * light * lc[q];
+                base * (1.0 - surf_op) + surface[q] * surf_op + spec * lc[q]
+            });
+            let a = (a + surf_op * (1.0 - a)).min(1.0);
+            *px = [cc[0] * a, cc[1] * a, cc[2] * a, a];
+        }
+    });
+    b
+}
+
+// ------------------------------------------------------------------ Wave World
+
+/// Wave World's simulated surface: an `nx` × `ny` grid of heights `u` and velocities `v`.
+#[derive(Clone, Debug)]
+pub struct Waves {
+    pub nx: usize,
+    pub ny: usize,
+    pub u: Vec<f32>,
+    pub v: Vec<f32>,
+}
+
+struct Producer {
+    ring: bool,
+    pos: [f32; 2],
+    len: f32,
+    width: f32,
+    angle: f32,
+    amp: f32,
+    freq: f32,
+    phase: f32,
+}
+
+impl Producer {
+    /// Weight of a grid point (layer-fraction coordinates, x in widths, y in widths).
+    fn weight(&self, x: f32, y: f32) -> f32 {
+        let (dx, dy) = (x - self.pos[0], y - self.pos[1]);
+        let (sa, ca) = self.angle.sin_cos();
+        let (u, v) = (dx * ca + dy * sa, -dx * sa + dy * ca);
+        let d = if self.ring {
+            let (a, bb) = ((self.len * 0.5).max(1e-3), (self.width * 0.5).max(1e-3));
+            ((u / a).powi(2) + (v / bb).powi(2)).sqrt()
+        } else {
+            let l = (self.len * 0.5).max(1e-3);
+            let wd = (self.width * 0.5).max(1e-3);
+            (u.abs() / l).max(v.abs() / wd)
+        };
+        (1.0 - d).clamp(0.0, 1.0).min(1.0)
+    }
+}
+
+static WAVE_CACHE: SimCache<Waves> = SimCache::new(4);
+
+/// What Wave World draws: the Height Map view of the simulated surface (grid heights and,
+/// with a ground layer, water depths per grid point), or the wireframe preview's lines.
+pub enum WavePlan {
+    Height { st: std::sync::Arc<Waves>, depth: Option<Vec<f32>> },
+    Wire(crate::sim::SpritePlan),
+}
+
+pub(super) fn wave_world(ctx: &EffectCtx, b: Buf) -> Buf {
+    match wave_world_impl(ctx, &b, false) {
+        Ok(img) => Buf { img, ..b },
+        Err(WavePlan::Wire(plan)) => plan.finish(b),
+        Err(WavePlan::Height { .. }) => b,
+    }
+}
+
+/// Wave World's simulation state for the frame, as a [`WavePlan`] (its pixels are not read).
+pub fn wave_world_plan(ctx: &EffectCtx, b: &Buf) -> Option<WavePlan> {
+    wave_world_impl(ctx, b, true).err()
+}
+
+fn wave_world_impl(ctx: &EffectCtx, b: &Buf, plan_only: bool) -> Result<Image, WavePlan> {
+    let pr = ctx.params;
+    let [lw, lh] = ctx.layer_size;
+    let res = pr.f("simulation/gridResolution").clamp(1.0, 400.0) as usize;
+    let res = if pr.b("simulation/gridResDownsamples") { ((res as f64) * b.scale).round().max(1.0) as usize } else { res };
+    let nx = res.max(2) + 1;
+    let ny = ((res as f64 * lh / lw.max(1.0)).round() as usize).max(2) + 1;
+    let speed = pr.f("simulation/waveSpeed").max(0.0) as f32;
+    let damping = pr.f("simulation/damping").max(0.0) as f32;
+    let reflect = pr.e("simulation/reflectEdges");
+    let preroll = pr.f("simulation/preRoll").max(0.0);
+    let prods: Vec<Producer> = [1, 2]
+        .iter()
+        .map(|k| {
+            let pos = pr.v2(&format!("producer{k}/producer{k}Position"));
+            Producer {
+                ring: pr.e(&format!("producer{k}/producer{k}Type")) == 0,
+                pos: [(pos[0] / lw.max(1.0)) as f32, (pos[1] / lw.max(1.0)) as f32],
+                len: pr.f(&format!("producer{k}/producer{k}Length")) as f32,
+                width: pr.f(&format!("producer{k}/producer{k}Width")) as f32,
+                angle: (pr.f(&format!("producer{k}/producer{k}Angle")) as f32).to_radians(),
+                amp: pr.f(&format!("producer{k}/producer{k}Amplitude")) as f32,
+                freq: pr.f(&format!("producer{k}/producer{k}Frequency")) as f32,
+                phase: (pr.f(&format!("producer{k}/producer{k}Phase")) as f32).to_radians(),
+            }
+        })
+        .collect();
+    let sps = crate::sim::SPS as f32;
+    // Wave speed in layer widths per second → cells per second; sub-steps keep it stable.
+    let cps = speed * (nx - 1) as f32;
+    let sub = ((cps * 2.0 / sps).ceil() as usize).clamp(1, 64);
+    let dt = 1.0 / (sps * sub as f32);
+    let cell = 1.0 / (nx - 1) as f32;
+    let weights: Vec<Vec<f32>> = prods.iter().map(|p| (0..nx * ny).map(|i| p.weight((i % nx) as f32 * cell, (i / nx) as f32 * cell)).collect()).collect();
+    // Ground: the ground layer's first frame, its luminance an elevation (× Steepness). Where
+    // it rises above Height the grid is dry (a wall the waves reflect from); shallow water
+    // slows the waves by Wave Strength.
+    let ground = pr.get("ground/ground").and_then(Value::as_layer).and_then(|id| {
+        let host = ctx.env.host?;
+        host.layer_at(id, ctx.env.comp_time - ctx.time, true)
+    });
+    let steep = pr.get("ground/steepness").map(Value::as_f64).unwrap_or(0.25) as f32;
+    let level = pr.get("ground/height").map(Value::as_f64).unwrap_or(0.25) as f32;
+    let wave_strength = pr.f("ground/waveStrength").clamp(0.0, 1.0) as f32;
+    // Water depth per grid point (None without ground: deep everywhere).
+    let depth: Option<Vec<f32>> = ground.as_ref().map(|lp| {
+        let (gw, gh) = (lp.size[0].max(1.0), lp.size[1].max(1.0));
+        (0..nx * ny)
+            .map(|i| {
+                let (fx, fy) = ((i % nx) as f64 / (nx - 1) as f64, (i / nx) as f64 / (ny - 1) as f64);
+                let (c, a) = unpremul(lp.buf.img.sample_bilinear_clamped(fx * gw * lp.buf.scale + lp.buf.offset[0], fy * gh * lp.buf.scale + lp.buf.offset[1]));
+                level - steep * effectcraft_color::luminance(c[0], c[1], c[2]) * a
+            })
+            .collect()
+    });
+    let speed_k: Vec<f32> = match &depth {
+        Some(d) => d.iter().map(|&v| if v <= 0.0 { 0.0 } else { 1.0 - wave_strength * (1.0 - (v / level.max(1e-3)).clamp(0.0, 1.0).sqrt()) }).collect(),
+        None => vec![1.0; nx * ny],
+    };
+    let mut key =
+        params_key(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: if pr.b("simulation/gridResDownsamples") { b.scale } else { 1.0 } }, 4);
+    if let Some(d) = &depth {
+        key ^= d.iter().fold(0u64, |a, v| a.rotate_left(3) ^ v.to_bits() as u64);
+    }
+    let steps = crate::sim::steps_at(ctx.time + preroll);
+    let st = WAVE_CACHE.run(
+        key,
+        steps,
+        || Waves { nx, ny, u: vec![0.0; nx * ny], v: vec![0.0; nx * ny] },
+        |w, step| {
+            for k in 0..sub {
+                let t = (step as f32 + k as f32 / sub as f32) / sps - preroll as f32;
+                let c2 = cps * cps;
+                let mut acc = vec![0.0f32; nx * ny];
+                for y in 0..ny {
+                    for x in 0..nx {
+                        let i = y * nx + x;
+                        let g = |xx: usize, yy: usize| w.u[yy * nx + xx];
+                        let l = g(x.saturating_sub(1), y) + g((x + 1).min(nx - 1), y) + g(x, y.saturating_sub(1)) + g(x, (y + 1).min(ny - 1)) - 4.0 * w.u[i];
+                        acc[i] = c2 * speed_k[i] * speed_k[i] * l - damping * 4.0 * w.v[i];
+                    }
+                }
+                for i in 0..nx * ny {
+                    w.v[i] += acc[i] * dt;
+                    w.u[i] += w.v[i] * dt;
+                }
+                // Producers drive the surface.
+                for (p, wt) in prods.iter().zip(&weights) {
+                    if p.amp == 0.0 {
+                        continue;
+                    }
+                    let target = p.amp * (std::f32::consts::TAU * p.freq * t + p.phase).sin();
+                    for i in 0..nx * ny {
+                        if wt[i] > 0.0 {
+                            w.u[i] += (target - w.u[i]) * wt[i];
+                            w.v[i] *= 1.0 - wt[i];
+                        }
+                    }
+                }
+                // Dry ground holds the surface flat.
+                for i in 0..nx * ny {
+                    if speed_k[i] <= 0.0 {
+                        w.u[i] = 0.0;
+                        w.v[i] = 0.0;
+                    }
+                }
+                // Edges: reflective ones mirror; the others absorb in a thin sponge layer.
+                let refl = |side: u32| reflect == 5 || reflect == side;
+                let sponge = 4usize.min(nx / 4).max(1);
+                for y in 0..ny {
+                    for x in 0..nx {
+                        let i = y * nx + x;
+                        let mut f = 1.0f32;
+                        if !refl(1) && x < sponge {
+                            f = f.min(x as f32 / sponge as f32);
+                        }
+                        if !refl(3) && nx - 1 - x < sponge {
+                            f = f.min((nx - 1 - x) as f32 / sponge as f32);
+                        }
+                        if !refl(2) && y < sponge {
+                            f = f.min(y as f32 / sponge as f32);
+                        }
+                        if !refl(4) && ny - 1 - y < sponge {
+                            f = f.min((ny - 1 - y) as f32 / sponge as f32);
+                        }
+                        if f < 1.0 {
+                            let k = 0.85 + 0.15 * f;
+                            w.u[i] *= k;
+                            w.v[i] *= k;
+                        }
+                    }
+                }
+            }
+        },
+    );
+    let s = b.scale;
+    let (bw, bh) = (b.img.width, b.img.height);
+    let sample = |x: f64, y: f64| -> f32 {
+        let gx = (x / lw.max(1.0) * (st.nx - 1) as f64).clamp(0.0, (st.nx - 1) as f64);
+        let gy = (y / lw.max(1.0) * (st.nx - 1) as f64).clamp(0.0, (st.ny - 1) as f64);
+        let (x0, y0) = (gx.floor() as usize, gy.floor() as usize);
+        let (x1, y1) = ((x0 + 1).min(st.nx - 1), (y0 + 1).min(st.ny - 1));
+        let (tx, ty) = ((gx - x0 as f64) as f32, (gy - y0 as f64) as f32);
+        let g = |xx: usize, yy: usize| st.u[yy * st.nx + xx];
+        let a = g(x0, y0) + (g(x1, y0) - g(x0, y0)) * tx;
+        let c = g(x0, y1) + (g(x1, y1) - g(x0, y1)) * tx;
+        a + (c - a) * ty
+    };
+    if plan_only && pr.e("view") == 1 {
+        return Err(WavePlan::Height { st, depth });
+    }
+    if pr.e("view") == 1 {
+        let mut img = Image::new(bw, bh);
+        let bright = pr.f("heightMapControls/brightness") as f32;
+        let contrast = pr.f("heightMapControls/contrast") as f32;
+        let gamma = pr.f("heightMapControls/gamma").max(0.01) as f32;
+        let alpha = 1.0 - pr.f("heightMapControls/transparency") as f32;
+        let dry_transparent = pr.e("heightMapControls/renderDryAreasAs") == 1;
+        let dry_at = |x: f64, y: f64| -> bool {
+            let Some(d) = &depth else { return false };
+            let gx = (x / lw.max(1.0) * (st.nx - 1) as f64).round().clamp(0.0, (st.nx - 1) as f64) as usize;
+            let gy = (y / lw.max(1.0) * (st.nx - 1) as f64).round().clamp(0.0, (st.ny - 1) as f64) as usize;
+            d[gy * st.nx + gx] <= 0.0
+        };
+        img.rows_mut().for_each(|(y, row)| {
+            for (x, px) in row.iter_mut().enumerate() {
+                let lx = (x as f64 + 0.5 - b.offset[0]) / s;
+                let ly = (y as f64 + 0.5 - b.offset[1]) / s;
+                let v = (bright + contrast * sample(lx, ly)).clamp(0.0, 1.0).powf(1.0 / gamma);
+                let al = if dry_transparent && dry_at(lx, ly) { 0.0 } else { alpha };
+                *px = [v * al, v * al, v * al, al];
+            }
+        });
+        Ok(img)
+    } else {
+        // Wireframe preview: the grid turned by Horizontal Rotation about the vertical axis,
+        // tilted by Vertical Rotation, heights scaled by Vertical Scale.
+        let hr = pr.f("wireframeControls/horizontalRotation").to_radians();
+        let vr = pr.get("wireframeControls/verticalRotation").map(Value::as_f64).unwrap_or(53.0).to_radians();
+        let vs = pr.get("wireframeControls/verticalScale").map(Value::as_f64).unwrap_or(0.5);
+        let (sh, ch) = hr.sin_cos();
+        let (sv, cv) = vr.sin_cos();
+        let to = |x: usize, y: usize| -> [f32; 2] {
+            // Grid point relative to the layer centre (layer px), height in layer px.
+            let gx = x as f64 / (st.nx - 1) as f64 * lw - lw * 0.5;
+            let gy = y as f64 / (st.nx - 1) as f64 * lw - (st.ny - 1) as f64 / (st.nx - 1) as f64 * lw * 0.5;
+            let hgt = st.u[y * st.nx + x] as f64 * vs * lh * 0.5;
+            let (rx, ry) = (gx * ch - gy * sh, gx * sh + gy * ch);
+            let (px, py) = b.to_px([lw * 0.5 + rx, lh * 0.5 + ry * cv - hgt * sv]);
+            [px as f32, py as f32]
+        };
+        let mut lines = Vec::new();
+        for y in 0..st.ny {
+            for x in 0..st.nx {
+                let a = to(x, y);
+                if x + 1 < st.nx {
+                    let c = to(x + 1, y);
+                    lines.push(Sprite::new(a[0], a[1], 0.4, [0.4, 0.9, 0.4, 1.0], Shape::Line { dx: c[0] - a[0], dy: c[1] - a[1] }));
+                }
+                if y + 1 < st.ny {
+                    let c = to(x, y + 1);
+                    lines.push(Sprite::new(a[0], a[1], 0.4, [0.4, 0.9, 0.4, 1.0], Shape::Line { dx: c[0] - a[0], dy: c[1] - a[1] }));
+                }
+            }
+        }
+        let plan = crate::sim::SpritePlan { sprites: lines, tints: vec![], acc: Acc::Over, post: crate::sim::Post::OverBlack };
+        if plan_only {
+            return Err(WavePlan::Wire(plan));
+        }
+        Ok(plan.finish(Buf { img: Image::new(bw, bh), offset: b.offset, scale: b.scale }).img)
+    }
+}
diff --git a/crates/effects/src/sim2/tests.rs b/crates/effects/src/sim2/tests.rs
new file mode 100644
index 000000000..2ef35b122
--- /dev/null
+++ b/crates/effects/src/sim2/tests.rs
@@ -0,0 +1,485 @@
+use super::*;
+use crate::{EffectEnv, run_fx};
+
+fn ramp(w: u32, hh: u32) -> Image {
+    let mut img = Image::new(w, hh);
+    for y in 0..hh {
+        for x in 0..w {
+            img.set(x, y, [x as f32 / w as f32, y as f32 / hh as f32, 0.4, 1.0]);
+        }
+    }
+    img
+}
+
+fn run(id: &str, vals: &[(&str, Value)], img: Image, t: f64) -> Image {
+    run_fx(id, vals, img, t, EffectEnv::default()).img
+}
+
+fn max_diff(a: &Image, b: &Image) -> f32 {
+    a.data.iter().zip(&b.data).map(|(p, q)| (0..4).map(|k| (p[k] - q[k]).abs()).fold(0.0, f32::max)).fold(0.0, f32::max)
+}
+
+fn sum_diff(a: &Image, b: &Image) -> f32 {
+    a.data.iter().zip(&b.data).map(|(p, q)| (0..4).map(|k| (p[k] - q[k]).abs()).sum::<f32>()).sum()
+}
+
+#[test]
+fn piece_at_rest_is_identity() {
+    let src = ramp(16, 16);
+    let cam = Cam { c: [8.0, 8.0], d: 64.0 };
+    let id = rot_axis([1.0, 0.0, 0.0], 0.0);
+    let pc = Piece::new(&[[0.0, 0.0], [16.0, 0.0], [16.0, 16.0], [0.0, 16.0]], [8.0, 8.0], &id, [8.0, 8.0, 0.0], cam).unwrap();
+    let mut out = Image::new(16, 16);
+    draw_pieces(&mut out, &[pc], &src, None);
+    assert!(max_diff(&out, &src) < 1e-4);
+}
+
+#[test]
+fn ball_action_draws_balls() {
+    let v = [("ballSize", num(80.0))];
+    let a = run("ec.sim.ccballaction", &v, ramp(32, 32), 0.0);
+    assert_eq!(a, run("ec.sim.ccballaction", &v, ramp(32, 32), 0.0));
+    assert!(a.data.iter().any(|p| p[3] > 0.9) && a.data.iter().any(|p| p[3] == 0.0), "balls with gaps");
+    let none = run("ec.sim.ccballaction", &[("ballSize", num(0.0))], ramp(32, 32), 0.0);
+    assert!(none.data.iter().all(|p| p[3] == 0.0));
+    let sc = run("ec.sim.ccballaction", &[("ballSize", num(80.0)), ("scatter", num(20.0))], ramp(32, 32), 0.0);
+    assert!(sum_diff(&a, &sc) > 1.0);
+}
+
+#[test]
+fn pixel_polly_breaks_after_start() {
+    let v = [("forceCenter", pt(16.0, 16.0)), ("gridSpacing", num(4.0))];
+    let before = run("ec.sim.ccpixelpolly", &v, ramp(32, 32), 0.0);
+    assert_eq!(before, ramp(32, 32), "intact before the start time");
+    let a = run("ec.sim.ccpixelpolly", &v, ramp(32, 32), 0.5);
+    assert_eq!(a, run("ec.sim.ccpixelpolly", &v, ramp(32, 32), 0.5));
+    assert!(sum_diff(&a, &ramp(32, 32)) > 10.0);
+    let tex = run("ec.sim.ccpixelpolly", &[("forceCenter", pt(16.0, 16.0)), ("gridSpacing", num(4.0)), ("object", Value::Enum(3))], ramp(32, 32), 0.5);
+    assert!(sum_diff(&a, &tex) > 0.1);
+}
+
+#[test]
+fn scatterize_identity_and_scatter() {
+    assert_eq!(run("ec.sim.ccscatterize", &[], ramp(24, 24), 0.0), ramp(24, 24));
+    let a = run("ec.sim.ccscatterize", &[("scatter", num(5.0))], ramp(24, 24), 0.0);
+    assert_eq!(a, run("ec.sim.ccscatterize", &[("scatter", num(5.0))], ramp(24, 24), 0.0));
+    assert!(sum_diff(&a, &ramp(24, 24)) > 1.0);
+    let tw = run("ec.sim.ccscatterize", &[("leftTwist", num(80.0)), ("rightTwist", num(80.0))], ramp(24, 24), 0.0);
+    assert!(sum_diff(&tw, &ramp(24, 24)) > 1.0);
+}
+
+#[test]
+fn card_dance_identity_and_rotation() {
+    let src = ramp(30, 20);
+    let a = run("ec.sim.carddance", &[], src.clone(), 0.0);
+    assert!(max_diff(&a, &src) < 0.02, "flat cards reproduce the layer: {}", max_diff(&a, &src));
+    let r = run("ec.sim.carddance", &[("yRotation/yRotSource", Value::Enum(1)), ("yRotation/yRotMultiplier", num(90.0))], src.clone(), 0.0);
+    assert_eq!(r, run("ec.sim.carddance", &[("yRotation/yRotSource", Value::Enum(1)), ("yRotation/yRotMultiplier", num(90.0))], src.clone(), 0.0));
+    assert!(sum_diff(&r, &src) > 5.0);
+    let z = run("ec.sim.carddance", &[("zPosition/zPosOffset", num(-1.0))], src.clone(), 0.0);
+    assert!(sum_diff(&z, &src) > 5.0, "cards pulled towards the camera grow");
+}
+
+#[test]
+fn shatter_at_rest_then_breaks() {
+    let v = [("view", Value::Enum(0)), ("force1/force1Position", pt(16.0, 16.0)), ("shape/origin", pt(16.0, 16.0))];
+    let src = ramp(32, 32);
+    let t0 = run("ec.sim.shatter", &v, src.clone(), 0.0);
+    assert!(max_diff(&t0, &src) < 0.03, "{}", max_diff(&t0, &src));
+    let t1 = run("ec.sim.shatter", &v, src.clone(), 0.5);
+    assert_eq!(t1, run("ec.sim.shatter", &v, src.clone(), 0.5));
+    assert!(sum_diff(&t1, &src) > 10.0);
+    for pat in 0..SHATTER_PATTERNS.len() as u32 {
+        let vv = [("view", Value::Enum(0)), ("shape/pattern", Value::Enum(pat)), ("force1/force1Position", pt(16.0, 16.0)), ("shape/origin", pt(16.0, 16.0))];
+        let r = run("ec.sim.shatter", &vv, src.clone(), 0.0);
+        assert!(max_diff(&r, &src) < 0.05, "pattern {pat} tiles the layer: {}", max_diff(&r, &src));
+    }
+    let wire = run("ec.sim.shatter", &[("shape/repetitions", num(3.0))], src.clone(), 0.0);
+    assert!(wire.data.iter().any(|p| p[3] > 0.5) && wire.data.iter().any(|p| p[3] == 0.0));
+    let layer_only =
+        run("ec.sim.shatter", &[("view", Value::Enum(0)), ("render", Value::Enum(1)), ("force1/force1Position", pt(16.0, 16.0))], src.clone(), 0.5);
+    assert!(layer_only.get(16, 16)[3] == 0.0, "broken centre removed");
+}
+
+#[test]
+fn caustics_flat_water() {
+    let src = ramp(24, 24);
+    let a = run(
+        "ec.sim.caustics",
+        &[
+            ("water/surfaceOpacity", num(0.0)),
+            ("lighting/ambientLight", num(0.0)),
+            ("material/diffuse", num(1.0)),
+            ("lighting/lightHeight", num(1000.0)),
+            ("material/specular", num(0.0)),
+        ],
+        src.clone(),
+        0.0,
+    );
+    assert!(max_diff(&a, &src) < 0.01, "flat water, light overhead = bottom: {}", max_diff(&a, &src));
+    let b = run("ec.sim.caustics", &[], src.clone(), 0.0);
+    assert_eq!(b, run("ec.sim.caustics", &[], src.clone(), 0.0));
+    assert!(sum_diff(&b, &src) > 0.1);
+}
+
+#[test]
+fn caustics_sky_and_light_types() {
+    let src = Image::filled(32, 32, [0.5, 0.5, 0.5, 1.0]);
+    let env = EffectEnv { host: Some(&FoamHost), ..Default::default() };
+    let run_h = |vals: &[(&str, Value)]| run_fx("ec.sim.caustics", vals, src.clone(), 0.0, env).img;
+    // A mirror-like surface shows the (green) sky.
+    let mirror = [("water/surfaceOpacity", num(1.0)), ("sky/sky", Value::Layer(Some(2))), ("sky/intensity", num(1.0))];
+    let p = run_h(&mirror).get(16, 16);
+    assert!(p[1] > p[0] + 0.3 && p[1] > p[2] + 0.3, "{p:?}");
+    // Point Source lights pixels by their own direction to the light: the image is no
+    // longer uniform; Distant Source lights the flat water evenly.
+    let lit = |t: u32| {
+        run_h(&[
+            ("lighting/lightType", Value::Enum(t)),
+            ("lighting/lightPosition", pt(0.0, 0.0)),
+            ("lighting/lightHeight", num(0.2)),
+            ("water/surfaceOpacity", num(0.0)),
+        ])
+    };
+    let (distant, point) = (lit(0), lit(1));
+    assert!((distant.get(2, 2)[0] - distant.get(30, 30)[0]).abs() < 1e-5);
+    assert!(point.get(2, 2)[0] > point.get(30, 30)[0] + 0.02, "{:?} {:?}", point.get(2, 2), point.get(30, 30));
+    // First Comp Light without a comp light: ambient only.
+    let none = run_h(&[("lighting/lightType", Value::Enum(2)), ("water/surfaceOpacity", num(0.0))]);
+    assert!(none.get(16, 16)[0] < distant.get(16, 16)[0]);
+}
+
+#[test]
+fn wave_world_wireframe_controls_ground_and_dry_areas() {
+    let base = [("producer1/producer1Position", pt(8.0, 16.0)), ("simulation/gridResolution", num(24.0))];
+    let wire = |extra: &[(&str, Value)]| run("ec.sim.waveworld", &[base.as_slice(), extra].concat(), Image::new(32, 32), 0.5);
+    assert_ne!(wire(&[]), wire(&[("wireframeControls/horizontalRotation", num(40.0))]));
+    assert_ne!(wire(&[]), wire(&[("wireframeControls/verticalScale", num(3.0))]));
+    // Ground (left dark, right light): the light side rises above the water and is dry.
+    let env = EffectEnv { host: Some(&FoamHost), ..Default::default() };
+    let hm = |extra: &[(&str, Value)]| {
+        let mut v: Vec<(&str, Value)> = base.to_vec();
+        v.extend([("view", Value::Enum(1)), ("ground/ground", Value::Layer(Some(1))), ("ground/steepness", num(0.5)), ("ground/height", num(0.25))]);
+        v.extend_from_slice(extra);
+        run_fx("ec.sim.waveworld", &v, Image::new(32, 32), 1.0, env).img
+    };
+    let solid = hm(&[]);
+    let clear = hm(&[("heightMapControls/renderDryAreasAs", Value::Enum(1))]);
+    assert!(solid.get(30, 16)[3] > 0.99 && clear.get(30, 16)[3] == 0.0);
+    assert!(clear.get(4, 16)[3] > 0.99, "wet side stays");
+    // Dry ground stays flat: mid grey (brightness 0.5) there.
+    assert!((solid.get(30, 16)[0] - 0.5).abs() < 1e-4);
+    // Wave Strength slows waves over shallow water: the surface differs.
+    assert_ne!(hm(&[]), hm(&[("ground/waveStrength", num(1.0))]));
+}
+
+#[test]
+fn wave_world_seek_and_waves() {
+    let v = vec![("view", Value::Enum(1)), ("producer1/producer1Position", pt(16.0, 16.0)), ("simulation/gridResolution", num(24.0))];
+    let _ = run("ec.sim.waveworld", &v, Image::new(32, 32), 0.5);
+    let a = run("ec.sim.waveworld", &v, Image::new(32, 32), 1.0);
+    let mut v2 = v.clone();
+    v2.push(("heightMapControls/transparency", num(0.0)));
+    assert_eq!(a, run("ec.sim.waveworld", &v2, Image::new(32, 32), 1.0));
+    // Waves spread: some pixels differ from the flat-water grey.
+    assert!(a.data.iter().any(|p| (p[0] - 0.5).abs() > 0.05), "waves");
+    let flat = run("ec.sim.waveworld", &[("view", Value::Enum(1)), ("producer1/producer1Amplitude", num(0.0))], Image::new(32, 32), 1.0);
+    assert!(flat.data.iter().all(|p| (p[0] - 0.5).abs() < 1e-5));
+    let wire = run("ec.sim.waveworld", &[("producer1/producer1Position", pt(16.0, 16.0)), ("simulation/gridResolution", num(10.0))], Image::new(32, 32), 0.3);
+    assert!(wire.data.iter().any(|p| p[1] > 0.3));
+}
+
+#[test]
+fn wave_world_steps_match_direct() {
+    // Fresh caches: resumed simulation equals simulation from scratch.
+    let v = vec![
+        ("view", Value::Enum(1)),
+        ("producer1/producer1Position", pt(16.0, 16.0)),
+        ("simulation/gridResolution", num(20.0)),
+        ("simulation/damping", num(0.07)),
+    ];
+    let a = run("ec.sim.waveworld", &v, Image::new(32, 32), 1.3);
+    let mut v2 = v.clone();
+    v2.push(("simulation/damping", num(0.07000001)));
+    // Different key: computed from scratch at 1.3 directly vs via 0.4 (both fresh keys).
+    let _ = run("ec.sim.waveworld", &v2, Image::new(32, 32), 0.4);
+    let b = run("ec.sim.waveworld", &v2, Image::new(32, 32), 1.3);
+    assert!(max_diff(&a, &b) < 1e-3, "{}", max_diff(&a, &b));
+}
+
+#[test]
+fn foam_bubbles_drift_and_seek() {
+    let v = vec![("producer/producerPoint", pt(16.0, 16.0)), ("view", Value::Enum(2)), ("producer/productionRate", num(2.0))];
+    let none = run("ec.sim.foam", &v, Image::new(32, 32), 0.0);
+    assert!(none.data.iter().all(|p| p[3] == 0.0));
+    let _ = run("ec.sim.foam", &v, Image::new(32, 32), 0.6);
+    let a = run("ec.sim.foam", &v, Image::new(32, 32), 1.2);
+    let mut v2 = v.clone();
+    v2.push(("randomSeed", num(1.0)));
+    assert_eq!(a, run("ec.sim.foam", &v2, Image::new(32, 32), 1.2));
+    assert!(a.data.iter().any(|p| p[3] > 0.05), "bubbles");
+    let draft = run("ec.sim.foam", &[("producer/producerPoint", pt(16.0, 16.0)), ("producer/productionRate", num(2.0))], Image::new(32, 32), 1.0);
+    assert!(draft.data.iter().any(|p| p[3] > 0.05));
+}
+
+#[test]
+fn foam_strength_controls_early_popping() {
+    // Strong bubbles all live their full lifespan; weak ones pop at random earlier.
+    assert_eq!(foam_pop_age(7, 300.0, 0.0, 1), 300.0);
+    let early = (0..200).filter(|&id| foam_pop_age(id, 300.0, 1.0, 1) < 150.0).count();
+    assert!(early > 60 && early < 140, "{early}");
+    let count = |strength: f64| {
+        let v = vec![
+            ("producer/producerPoint", pt(16.0, 16.0)),
+            ("producer/productionRate", num(3.0)),
+            ("bubbles/lifespan", num(40.0)),
+            ("bubbles/strength", num(strength)),
+            ("physics/windSpeed", num(0.0)),
+        ];
+        run("ec.sim.foam", &v, Image::new(32, 32), 1.5).data.iter().map(|p| p[3]).sum::<f32>()
+    };
+    assert!(count(0.0) < count(20.0) * 0.9, "{} vs {}", count(0.0), count(20.0));
+}
+
+/// A host with a comp camera (identity, or tilted) and a first comp light.
+struct Scene {
+    camera: Option<[[f64; 4]; 3]>,
+    light: Option<crate::CompLight>,
+    layer: Option<Image>,
+}
+impl crate::EffectHost for Scene {
+    fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
+        let img = self.layer.clone()?;
+        let size = [img.width as f64, img.height as f64];
+        Some(crate::LayerPixels { buf: Buf { img, offset: [0.0; 2], scale: 1.0 }, size })
+    }
+    fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+        None
+    }
+    fn comp_scene(&self) -> Option<crate::CompScene> {
+        Some(crate::CompScene { camera: self.camera, camera_layer: true, light: self.light })
+    }
+}
+
+fn run_env(id: &str, vals: &[(&str, Value)], img: Image, t: f64, host: &Scene) -> Image {
+    run_fx(id, vals, img, t, EffectEnv { host: Some(host), ..Default::default() }).img
+}
+
+#[test]
+fn card_dance_camera_systems() {
+    let src = ramp(40, 30);
+    // Camera Position: rotating the camera changes the view; zero rotation is the layer.
+    let r = run("ec.sim.carddance", &[("cameraPosition/yRotation", num(30.0))], src.clone(), 0.0);
+    assert!(sum_diff(&r, &src) > 10.0);
+    let order = run("ec.sim.carddance", &[("cameraPosition/yRotation", num(30.0)), ("cameraPosition/xRotation", num(30.0))], src.clone(), 0.0);
+    let order2 = run(
+        "ec.sim.carddance",
+        &[("cameraPosition/yRotation", num(30.0)), ("cameraPosition/xRotation", num(30.0)), ("cameraPosition/transformOrder", Value::Enum(5))],
+        src.clone(),
+        0.0,
+    );
+    assert!(sum_diff(&order, &order2) > 1.0, "Transform Order matters");
+    // X, Y Position moves the view: the layer shifts by the offset.
+    let moved = run("ec.sim.carddance", &[("cameraPosition/xyPosition", pt(30.0, 15.0))], src.clone(), 0.0);
+    assert!((moved.get(25, 10)[0] - src.get(15, 10)[0]).abs() < 0.03, "{:?} {:?}", moved.get(25, 10), src.get(15, 10));
+    // Corner Pins: the layer's corners land on the pins.
+    let pins = [
+        ("cameraSystem", Value::Enum(1)),
+        ("cornerPins/upperLeftCorner", pt(10.0, 5.0)),
+        ("cornerPins/upperRightCorner", pt(30.0, 5.0)),
+        ("cornerPins/lowerLeftCorner", pt(10.0, 25.0)),
+        ("cornerPins/lowerRightCorner", pt(30.0, 25.0)),
+    ];
+    let cp = run("ec.sim.carddance", &pins, src.clone(), 0.0);
+    assert_eq!(cp.get(3, 3)[3], 0.0, "outside the pinned quad");
+    assert!(cp.get(20, 15)[3] > 0.99);
+    assert!((cp.get(20, 15)[0] - src.get(20, 15)[0]).abs() < 0.05, "centre maps to centre");
+    // Comp Camera: the identity camera reproduces the layer; a camera that doubles x moves it.
+    let ident = Scene { camera: Some([[1.0, 0.0, 0.0, 0.0], [0.0, 1.0, 0.0, 0.0], [0.0, 0.0, 0.002, 1.0]]), light: None, layer: None };
+    let cc = run_env("ec.sim.carddance", &[("cameraSystem", Value::Enum(2))], src.clone(), 0.0, &ident);
+    assert!(max_diff(&cc, &src) < 0.02, "{}", max_diff(&cc, &src));
+    let half = Scene { camera: Some([[0.5, 0.0, 0.0, 0.0], [0.0, 0.5, 0.0, 0.0], [0.0, 0.0, 0.002, 1.0]]), ..ident };
+    let cc = run_env("ec.sim.carddance", &[("cameraSystem", Value::Enum(2))], src.clone(), 0.0, &half);
+    assert_eq!(cc.get(35, 25)[3], 0.0, "half-size view leaves the far corner empty");
+}
+
+#[test]
+fn card_dance_lighting_and_material() {
+    let src = Image::filled(40, 30, [0.5, 0.5, 0.5, 1.0]);
+    let tilt = [("rows", num(1.0)), ("columns", num(1.0)), ("yRotation/yRotSource", Value::Enum(0)), ("yRotation/yRotOffset", num(60.0))];
+    let lit = |extra: &[(&str, Value)]| {
+        let mut v: Vec<(&str, Value)> = tilt.to_vec();
+        v.extend_from_slice(extra);
+        run("ec.sim.carddance", &v, src.clone(), 0.0).get(20, 15)
+    };
+    let base = lit(&[]);
+    // Tilted cards facing away from a frontal light get darker than flat ones.
+    assert!(base[0] < 0.45, "{base:?}");
+    // Light colour tints; intensity brightens; ambient alone lights evenly.
+    let red = lit(&[("lighting/lightColor", col(1.0, 0.0, 0.0))]);
+    assert!(red[0] > red[1] + 0.05);
+    assert!(lit(&[("lighting/lightIntensity", num(2.0))])[0] > base[0]);
+    let amb = lit(&[("lighting/ambientLight", num(1.0)), ("material/diffuse", num(0.0))]);
+    assert!((amb[0] - 0.5).abs() < 1e-3);
+    // A light placed to the side (Point Source) changes the shading of the tilted card.
+    let side = lit(&[("lighting/lightType", Value::Enum(1)), ("lighting/lightPosition", pt(200.0, 15.0)), ("lighting/lightDepth", num(0.2))]);
+    assert!((side[0] - base[0]).abs() > 0.02, "{side:?} vs {base:?}");
+    // Specular adds a highlight on flat, frontally lit cards.
+    let flat = run("ec.sim.carddance", &[("material/specular", num(0.5))], src.clone(), 0.0).get(20, 15);
+    assert!(flat[0] > 0.9, "{flat:?}");
+    // First Comp Light: no light in the comp → ambient only; a light from the host is used.
+    let none = Scene { camera: None, light: None, layer: None };
+    let a = run_env("ec.sim.carddance", &[("lighting/lightType", Value::Enum(2))], src.clone(), 0.0, &none).get(20, 15);
+    assert!((a[0] - 0.5 * (0.25 + 0.75)).abs() < 1e-3, "{a:?}");
+    let blue = Scene { light: Some(crate::CompLight { pos: [20.0, 15.0, -100.0], dir: [0.0, 0.0, 1.0], color: [0.0, 0.0, 1.0], kind: 0 }), ..none };
+    let a = run_env("ec.sim.carddance", &[("lighting/lightType", Value::Enum(2))], src.clone(), 0.0, &blue).get(20, 15);
+    assert!(a[2] > a[0] + 0.2, "{a:?}");
+}
+
+#[test]
+fn shatter_custom_map_gradient_textures_and_extrusion() {
+    let src = ramp(32, 32);
+    let base = [("view", Value::Enum(0)), ("force1/force1Position", pt(16.0, 16.0)), ("force1/force1Radius", num(2.0)), ("shape/origin", pt(16.0, 16.0))];
+    let with = |extra: &[(&str, Value)], t: f64, host: Option<&Scene>| {
+        let mut v: Vec<(&str, Value)> = base.to_vec();
+        v.extend_from_slice(extra);
+        match host {
+            Some(h) => run_env("ec.sim.shatter", &v, src.clone(), t, h),
+            None => run("ec.sim.shatter", &v, src.clone(), t),
+        }
+    };
+    // Custom Shatter Map: a map white on the left and black on the right; with White Tiles
+    // Fixed the left half stays put while the right half breaks away.
+    let mut map = Image::new(32, 32);
+    for y in 0..32 {
+        for x in 0..32 {
+            map.set(x, y, if x < 16 { [1.0; 4] } else { [0.0, 0.0, 0.0, 1.0] });
+        }
+    }
+    let host = Scene { camera: None, light: None, layer: Some(map) };
+    let custom = [("shape/pattern", Value::Enum(5)), ("shape/customShatterMap", Value::Layer(Some(1))), ("shape/whiteTilesFixed", Value::Bool(true))];
+    let at_rest = with(&custom, 0.0, Some(&host));
+    assert!(max_diff(&at_rest, &src) < 0.05, "custom pieces tile the layer: {}", max_diff(&at_rest, &src));
+    let broke = with(&custom, 1.0, Some(&host));
+    assert!(max_diff_region(&broke, &src, 0..12) < 0.05, "white tiles fixed");
+    assert!(sum_diff_region(&broke, &src, 20..32) > 5.0, "black group moved");
+    // Gradient: a black gradient layer with threshold 50 % keeps everything together.
+    let black = Scene { camera: None, light: None, layer: Some(Image::filled(32, 32, [0.0, 0.0, 0.0, 1.0])) };
+    let g = with(&[("gradient/gradientLayer", Value::Layer(Some(1))), ("gradient/shatterThreshold", num(50.0))], 1.0, Some(&black));
+    assert!(max_diff(&g, &src) < 0.05);
+    let gi = with(
+        &[("gradient/gradientLayer", Value::Layer(Some(1))), ("gradient/shatterThreshold", num(50.0)), ("gradient/invertGradient", Value::Bool(true))],
+        1.0,
+        Some(&black),
+    );
+    assert!(sum_diff(&gi, &src) > 10.0);
+    // Textures: Front Mode Color paints the pieces flat; Opacity fades them.
+    let flat = with(&[("textures/frontMode", Value::Enum(0)), ("textures/color", col(0.0, 1.0, 0.0))], 0.0, None);
+    let p = flat.get(16, 16);
+    assert!(p[1] > 0.95 && p[0] < 0.05, "{p:?}");
+    let half = with(&[("textures/opacity", num(0.5)), ("shape/repetitions", num(2.0))], 0.0, None);
+    assert!((half.get(8, 4)[3] - 0.5).abs() < 0.02, "{:?}", half.get(8, 4));
+    // Extrusion: thicker pieces cover more once they tumble.
+    let cover = |d: f64| {
+        with(&[("shape/extrusionDepth", num(d)), ("textures/sideMode", Value::Enum(0)), ("textures/color", col(1.0, 1.0, 1.0))], 0.6, None)
+            .data
+            .iter()
+            .map(|p| p[3])
+            .sum::<f32>()
+    };
+    assert!(cover(1.0) > cover(0.0) + 1.0, "{} vs {}", cover(1.0), cover(0.0));
+    // Deterministic and seek-consistent.
+    assert_eq!(with(&custom, 0.7, Some(&host)), with(&custom, 0.7, Some(&host)));
+}
+
+fn max_diff_region(a: &Image, b: &Image, xs: std::ops::Range<u32>) -> f32 {
+    let mut m = 0.0f32;
+    for y in 0..a.height {
+        for x in xs.clone() {
+            let (p, q) = (a.get(x as i64, y as i64), b.get(x as i64, y as i64));
+            m = (0..4).map(|k| (p[k] - q[k]).abs()).fold(m, f32::max);
+        }
+    }
+    m
+}
+
+fn sum_diff_region(a: &Image, b: &Image, xs: std::ops::Range<u32>) -> f32 {
+    let mut s = 0.0;
+    for y in 0..a.height {
+        for x in xs.clone() {
+            let (p, q) = (a.get(x as i64, y as i64), b.get(x as i64, y as i64));
+            s += (0..4).map(|k| (p[k] - q[k]).abs()).sum::<f32>();
+        }
+    }
+    s
+}
+
+/// Layer 1 = a left-dark, right-light ramp; layer 2 = solid green.
+struct FoamHost;
+impl crate::EffectHost for FoamHost {
+    fn layer(&self, id: u64, _: bool) -> Option<crate::LayerPixels> {
+        let img = if id == 1 { ramp(32, 32) } else { Image::filled(32, 32, [0.0, 1.0, 0.0, 1.0]) };
+        Some(crate::LayerPixels { buf: Buf { img, offset: [0.0; 2], scale: 1.0 }, size: [32.0, 32.0] })
+    }
+    fn layer_at(&self, id: u64, _: f64, me: bool) -> Option<crate::LayerPixels> {
+        self.layer(id, me)
+    }
+    fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+        None
+    }
+}
+
+#[test]
+fn foam_flow_map_pop_velocity_wobble_textures_and_reflection() {
+    let base = vec![
+        ("producer/producerPoint", pt(16.0, 16.0)),
+        ("producer/productionRate", num(2.0)),
+        ("physics/windSpeed", num(0.0)),
+        ("physics/turbulence", num(0.0)),
+        ("view", Value::Enum(2)),
+    ];
+    let with = |extra: &[(&str, Value)], t: f64| {
+        let mut v = base.clone();
+        v.extend_from_slice(extra);
+        run_fx("ec.sim.foam", &v, Image::new(32, 32), t, EffectEnv { host: Some(&FoamHost), ..Default::default() }).img
+    };
+    let cx = |img: &Image| {
+        let (mut s, mut n) = (0.0, 0.0);
+        for y in 0..32 {
+            for x in 0..32 {
+                let a = img.get(x, y)[3];
+                s += a * x as f32;
+                n += a;
+            }
+        }
+        s / n.max(1e-6)
+    };
+    // Flow map: bubbles run downhill (towards the dark left side).
+    let still = with(&[], 1.0);
+    let flowing = with(&[("flowMap/flowMap", Value::Layer(Some(1))), ("flowMap/flowMapSteepness", num(1.0))], 1.0);
+    assert!(cx(&flowing) < cx(&still) - 1.0, "{} vs {}", cx(&flowing), cx(&still));
+    let hq = with(&[("flowMap/flowMap", Value::Layer(Some(1))), ("flowMap/flowMapSteepness", num(1.0)), ("flowMap/simulationQuality", Value::Enum(2))], 1.0);
+    assert_eq!(
+        hq,
+        with(&[("flowMap/flowMap", Value::Layer(Some(1))), ("flowMap/flowMapSteepness", num(1.0)), ("flowMap/simulationQuality", Value::Enum(2))], 1.0)
+    );
+    // Pop velocity scatters the survivors when short-lived bubbles pop.
+    let short = [("bubbles/lifespan", num(8.0)), ("bubbles/strength", num(0.0))];
+    let a = with(&[short.as_slice(), &[("physics/popVelocity", num(0.0))]].concat(), 1.0);
+    let b2 = with(&[short.as_slice(), &[("physics/popVelocity", num(20.0))]].concat(), 1.0);
+    assert_ne!(a, b2);
+    // Wobble changes the drawn bubbles.
+    assert_ne!(with(&[("physics/wobbleAmount", num(0.0))], 1.0), with(&[("physics/wobbleAmount", num(3.0))], 1.0));
+    // User Defined texture: bubbles show the texture layer (green).
+    let tex = with(&[("rendering/bubbleTexture", Value::Enum(5)), ("rendering/bubbleTextureLayer", Value::Layer(Some(2)))], 1.0);
+    assert!(tex.data.iter().any(|p| p[1] > 0.5 && p[0] < 0.1));
+    // Environment map: reflections tint the bubbles.
+    let refl = with(&[("rendering/environmentMap", Value::Layer(Some(2))), ("rendering/reflectionStrength", num(1.0))], 1.0);
+    let g = |i: &Image| i.data.iter().map(|p| p[1] - p[0]).sum::<f32>();
+    assert!(g(&refl) > g(&still) + 1.0);
+    // Zoom Producer Point zooms about the producer instead of the layer centre.
+    let off = [("producer/producerPoint", pt(8.0, 8.0)), ("zoom", num(2.0))];
+    let z1 = with(&off, 1.0);
+    let z2 = with(&[off.as_slice(), &[("producer/zoomProducerPoint", Value::Bool(true))]].concat(), 1.0);
+    assert!((cx(&z2) - 8.0).abs() < 2.0 && cx(&z1) < 4.0, "{} vs {}", cx(&z2), cx(&z1));
+}
diff --git a/crates/effects/src/sim3.rs b/crates/effects/src/sim3.rs
index 35c758faa..88a16d981 100644
--- a/crates/effects/src/sim3.rs
+++ b/crates/effects/src/sim3.rs
@@ -575,7 +575,8 @@ fn mapper_from(ctx: &EffectCtx, group: &str, ephemeral: bool) -> Option<Mapper>
 
 /// Draw a map layer frame as a particle: centred on (x, y) buffer px, rotated `angle` degrees
 /// and scaled, over `out`.
-fn blit_layer(out: &mut Image, lp: &crate::LayerPixels, x: f64, y: f64, angle: f64, scale: [f64; 2], buf_scale: f64, alpha: f32) {
+fn blit_layer(out: &mut Image, lp: &crate::LayerPixels, position: [f64; 2], angle: f64, scale: [f64; 2], buf_scale: f64, alpha: f32) {
+    let [x, y] = position;
     let (w, h) = (lp.size[0] * scale[0].abs() * buf_scale, lp.size[1] * scale[1].abs() * buf_scale);
     let r = (w * w + h * h).sqrt() * 0.5 + 1.0;
     let (x0, x1) = ((x - r).floor().max(0.0) as i64, (x + r).ceil().min(out.width as f64) as i64);
@@ -925,7 +926,7 @@ impl PgPlan {
     pub fn finish(&self, mut b: Buf) -> Buf {
         let mut fx = splat(b.img.width, b.img.height, &self.sprites.sprites, self.sprites.acc);
         for q in &self.blits {
-            blit_layer(&mut fx, &self.frames[q.frame], q.x, q.y, q.angle, q.scale, b.scale, q.alpha);
+            blit_layer(&mut fx, &self.frames[q.frame], [q.x, q.y], q.angle, q.scale, b.scale, q.alpha);
         }
         // Particles replace the layer's own pixels.
         b.img = combine(&b.img, &fx, 5);
@@ -1176,379 +1177,4 @@ pub fn specs() -> Vec<EffectSpec> {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::{EffectEnv, MaskShape, run_fx};
-
-    fn run(vals: &[(&str, Value)], t: f64) -> Image {
-        run_fx("ec.sim.particleplayground", vals, Image::filled(80, 60, [0.2, 0.2, 0.2, 1.0]), t, EffectEnv::default()).img
-    }
-
-    fn cannon(t: f64) -> Image {
-        run(&[("cannon/cannonPosition", Value::Vec2([40.0, 50.0])), ("cannon/velocity", num(60.0)), ("gravity/gravityForce", num(30.0))], t)
-    }
-
-    #[test]
-    fn cannon_stream_is_seek_consistent() {
-        let a = cannon(1.0);
-        // Particles replace the layer: some coverage, mostly transparent, red.
-        let cov: f32 = a.data.iter().map(|p| p[3]).sum();
-        assert!(cov > 5.0, "{cov}");
-        assert!(a.data.iter().any(|p| p[3] > 0.5 && p[0] > 0.5 && p[1] < 0.1));
-        // Seek back and forth: the same frame every time.
-        let _ = cannon(2.0);
-        let b = cannon(1.0);
-        assert_eq!(a.data, b.data);
-        let c = cannon(0.5);
-        assert_ne!(a.data, c.data);
-        // Nothing has been fired at time 0.
-        let z = cannon(0.0);
-        assert!(z.data.iter().all(|p| p[3] == 0.0));
-    }
-
-    #[test]
-    fn grid_falls_with_gravity_and_bounces_off_a_wall() {
-        let grid = |t: f64, env: EffectEnv| {
-            run_fx(
-                "ec.sim.particleplayground",
-                &[
-                    ("cannonEnabled", Value::Bool(false)),
-                    ("grid/gridPosition", Value::Vec2([40.0, 10.0])),
-                    ("grid/gridWidth", num(40.0)),
-                    ("grid/gridHeight", num(0.0)),
-                    ("grid/particlesAcross", num(5.0)),
-                    ("grid/particlesDown", num(1.0)),
-                    ("gravity/gravityForce", num(100.0)),
-                    ("wall/wallBoundary", num(1.0)),
-                ],
-                Image::new(80, 60),
-                t,
-                env,
-            )
-            .img
-        };
-        // Alpha-weighted mean height of the particles.
-        let row_of = |img: &Image| {
-            let (mut s, mut n) = (0.0f64, 0.0f64);
-            for y in 0..60 {
-                for x in 0..80 {
-                    let a = img.get(x, y)[3] as f64;
-                    s += (y as f64 + 0.5) * a;
-                    n += a;
-                }
-            }
-            (s / n.max(1e-9)).round() as i64
-        };
-        let t0 = grid(0.0, EffectEnv::default());
-        let t1 = grid(0.5, EffectEnv::default());
-        assert_eq!(row_of(&t0), 10);
-        // ½ g t² = 12.5 px.
-        assert!((row_of(&t1) - 22).abs() <= 2, "{}", row_of(&t1));
-        // A wall (mask 1) whose floor is at y = 15 keeps them above it.
-        let masks = [MaskShape { name: "w".into(), points: vec![[0.0, 0.0], [80.0, 0.0], [80.0, 15.0], [0.0, 15.0]], closed: true, inverted: false }];
-        let env = EffectEnv { masks: &masks, ..Default::default() };
-        let w = grid(1.5, env);
-        assert!(row_of(&w) <= 16, "{}", row_of(&w));
-    }
-
-    #[test]
-    fn repel_spreads_particles() {
-        let spread = |force: f64| {
-            let img = run(
-                &[
-                    ("cannonEnabled", Value::Bool(false)),
-                    ("grid/gridPosition", Value::Vec2([40.0, 30.0])),
-                    ("grid/gridWidth", num(6.0)),
-                    ("grid/gridHeight", num(6.0)),
-                    ("grid/particlesAcross", num(3.0)),
-                    ("grid/particlesDown", num(3.0)),
-                    ("gravity/gravityForce", num(0.0)),
-                    ("repel/repelForce", num(force)),
-                    ("repel/repelForceRadius", num(20.0)),
-                ],
-                0.5,
-            );
-            let (mut x0, mut x1) = (80, 0);
-            for y in 0..60 {
-                for x in 0..80 {
-                    if img.get(x, y)[3] > 0.3 {
-                        x0 = x0.min(x);
-                        x1 = x1.max(x);
-                    }
-                }
-            }
-            x1 - x0
-        };
-        assert!(spread(0.2) > spread(0.0) + 4, "{} vs {}", spread(0.2), spread(0.0));
-    }
-
-    #[test]
-    fn property_mapper_and_layer_map_read_layers() {
-        // Without a host, the layer-based features are inert (deterministic output).
-        let a = run(
-            &[
-                ("persistentPropertyMapper/mapRedTo", Value::Enum(8)),
-                ("persistentPropertyMapper/redMin", num(-50.0)),
-                ("persistentPropertyMapper/redMax", num(50.0)),
-            ],
-            0.7,
-        );
-        let b = run(
-            &[
-                ("persistentPropertyMapper/mapRedTo", Value::Enum(8)),
-                ("persistentPropertyMapper/redMin", num(-50.0)),
-                ("persistentPropertyMapper/redMax", num(50.0)),
-            ],
-            0.7,
-        );
-        assert_eq!(a.data, b.data);
-        let st =
-            Pg { persistent: Some(mapper(Image::filled(4, 4, [1.0, 0.0, 0.5, 1.0]), [(15, 0, 0.0, 120.0), (0, 0, 0.0, 1.0), (9, 0, 0.0, 2.0)])), ..bare(1) };
-        let mut s = PgState::default();
-        s.parts.push(PgParticle::new([1.0, 1.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID));
-        st.step(&mut s);
-        // Red 1 → X speed 120 px/s; blue 0.5 → scale 1.
-        assert!((s.parts[0].v[0] - 120.0).abs() < 1e-3);
-        assert!((s.parts[0].scale[0] - 1.0).abs() < 1e-3);
-    }
-
-    /// A Pg with nothing switched on.
-    fn bare(seed: u32) -> Pg {
-        Pg {
-            cannon: false,
-            pos: [0.0; 2],
-            barrel_angle: 0.0,
-            barrel_radius: 0.0,
-            rate: 0.0,
-            dir_spread: 0.0,
-            vel: 0.0,
-            vel_spread: 0.0,
-            color: [1.0; 4],
-            radius: 2.0,
-            cannon_text: vec![],
-            pex_radius: 0.0,
-            pex_dispersion: 0.0,
-            pex_affects: Affects::default(),
-            gravity: [0.0; 2],
-            grav_spread: 0.0,
-            grav_affects: Affects::default(),
-            repel: 0.0,
-            repel_radius: 0.0,
-            repel_affects: Affects::default(),
-            wall: None,
-            wall_affects: Affects::default(),
-            persistent: None,
-            ephemeral: None,
-            seed,
-            bounds: [-1e6, -1e6, 1e6, 1e6],
-        }
-    }
-
-    fn mapper(img: Image, chans: [(u32, u32, f32, f32); 3]) -> Mapper {
-        Mapper { map: MapImg { img, k: [1.0; 2], o: [0.0; 2] }, chans, affects: Affects::default() }
-    }
-
-    #[test]
-    fn barrel_radius_square_or_disc() {
-        let pg = |r: f32| Pg { cannon: true, barrel_radius: r, ..bare(3) };
-        let (sq, disc) = (pg(10.0), pg(-10.0));
-        let mut corner = false;
-        for id in 0..400 {
-            let a = sq.spawn(id).p;
-            assert!(a[0].abs() <= 10.0 && a[1].abs() <= 10.0);
-            // A square barrel fills its corners (both offsets in use, not a line).
-            corner |= a[0].abs() > 7.5 && a[1].abs() > 7.5;
-            let b = disc.spawn(id).p;
-            assert!(b[0].hypot(b[1]) <= 10.0 + 1e-4);
-        }
-        assert!(corner);
-        // Radius 0: every particle starts at the cannon position.
-        assert_eq!(pg(0.0).spawn(5).p, [0.0, 0.0]);
-    }
-
-    #[test]
-    fn mapper_drives_position_and_opacity_in_ae_order() {
-        let st =
-            Pg { persistent: Some(mapper(Image::filled(4, 4, [1.0, 0.5, 0.25, 1.0]), [(12, 0, 0.0, 30.0), (20, 0, 0.0, 1.0), (4, 0, 0.0, 1.0)])), ..bare(1) };
-        assert_eq!(MAP_TARGETS[12], "X");
-        assert_eq!(MAP_TARGETS[20], "Opacity");
-        assert_eq!(MAP_TARGETS[26], "Scale Speed");
-        let mut s = PgState::default();
-        s.parts.push(PgParticle::new([1.0, 1.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID));
-        st.step(&mut s);
-        assert!((s.parts[0].p[0] - 30.0).abs() < 1e-3, "{:?}", s.parts[0].p);
-        assert!((s.parts[0].c[3] - 0.5).abs() < 1e-3);
-        assert!((s.parts[0].friction - 0.25).abs() < 1e-3);
-    }
-
-    #[test]
-    fn ephemeral_mapper_holds_for_one_step_with_operators() {
-        // Ephemeral X Speed = 60 px/s (Set): the particle moves, but keeps no velocity.
-        let st = Pg { ephemeral: Some(mapper(Image::filled(4, 4, [1.0, 1.0, 1.0, 1.0]), [(15, 0, 0.0, 60.0), (0, 0, 0.0, 1.0), (0, 0, 0.0, 1.0)])), ..bare(1) };
-        let mut s = PgState::default();
-        s.parts.push(PgParticle::new([1.0, 1.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID));
-        st.step(&mut s);
-        assert!((s.parts[0].p[0] - 2.0).abs() < 1e-4, "{:?}", s.parts[0].p);
-        assert!(s.parts[0].v[0].abs() < 1e-4);
-        // Operators: Add / Multiply / Max on the particle's own value.
-        let op = |o: u32, cur: f32| {
-            let m = mapper(Image::filled(4, 4, [1.0, 1.0, 1.0, 1.0]), [(21, o, 0.0, 3.0), (0, 0, 0.0, 1.0), (0, 0, 0.0, 1.0)]);
-            let mut q = PgParticle::new([1.0, 1.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID);
-            q.mass = cur;
-            m.apply(&mut q);
-            q.mass
-        };
-        assert_eq!(MAP_OPERATORS[1], "Add");
-        assert!((op(1, 2.0) - 5.0).abs() < 1e-5);
-        assert!((op(4, 2.0) - 6.0).abs() < 1e-5);
-        assert!((op(6, 5.0) - 5.0).abs() < 1e-5);
-        assert!((op(2, 5.0) - 2.0).abs() < 1e-5, "Difference");
-    }
-
-    #[test]
-    fn affects_select_by_source_age_and_characters() {
-        let mut q = PgParticle::new([0.0; 2], [0.0; 2], [1.0; 4], 2.0, 0, SRC_CANNON);
-        let a = Affects { from: 2, ..Default::default() };
-        assert_eq!(a.weight(&q), 0.0, "grid only");
-        q.src = SRC_GRID;
-        assert_eq!(a.weight(&q), 1.0);
-        let older = Affects { age: 1.0, ..Default::default() };
-        q.age = 0.5;
-        assert_eq!(older.weight(&q), 0.0);
-        q.age = 1.5;
-        assert_eq!(older.weight(&q), 1.0);
-        let younger = Affects { age: -1.0, feather: 1.0, ..Default::default() };
-        q.age = 1.0;
-        assert!((younger.weight(&q) - 0.5).abs() < 1e-5, "feathered");
-        let chars = Affects { chars: vec!['A', 'B'], ..Default::default() };
-        q.ch = 'B' as u32;
-        assert_eq!(chars.weight(&q), 1.0);
-        q.ch = 'C' as u32;
-        assert_eq!(chars.weight(&q), 0.0);
-        // Gravity restricted to the cannon leaves grid particles in place.
-        let st = Pg { gravity: [0.0, 100.0], grav_affects: Affects { from: 1, ..Default::default() }, ..bare(1) };
-        let mut s = PgState::default();
-        s.parts.push(PgParticle::new([5.0, 5.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID));
-        s.parts.push(PgParticle::new([5.0, 5.0], [0.0; 2], [1.0; 4], 2.0, 1, SRC_CANNON));
-        for _ in 0..10 {
-            st.step(&mut s);
-        }
-        assert_eq!(s.parts[0].p, [5.0, 5.0]);
-        assert!(s.parts[1].p[1] > 5.0);
-    }
-
-    #[test]
-    fn particle_exploder_bursts_big_particles() {
-        let st = Pg { pex_radius: 2.0, pex_dispersion: 30.0, ..bare(1) };
-        let mut s = PgState::default();
-        s.parts.push(PgParticle::new([50.0, 50.0], [0.0; 2], [1.0; 4], 6.0, 0, SRC_GRID));
-        s.next_id = 1;
-        st.step(&mut s);
-        assert_eq!(s.parts.len(), 9, "(6/2)² new particles");
-        assert!(s.parts.iter().all(|q| q.r == 2.0 && q.src == SRC_PARTICLE_EXPLODER));
-        st.step(&mut s);
-        assert_eq!(s.parts.len(), 9, "new particles do not burst again");
-        // Lifespan from a mapper removes particles once they are older.
-        let life = Pg { persistent: Some(mapper(Image::filled(4, 4, [1.0; 4]), [(22, 0, 0.0, 0.05), (0, 0, 0.0, 1.0), (0, 0, 0.0, 1.0)])), ..bare(1) };
-        let mut s = PgState::default();
-        s.parts.push(PgParticle::new([1.0, 1.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID));
-        for _ in 0..2 {
-            life.step(&mut s);
-        }
-        assert_eq!(s.parts.len(), 1);
-        for _ in 0..3 {
-            life.step(&mut s);
-        }
-        assert!(s.parts.is_empty());
-    }
-
-    #[test]
-    fn text_particles_draw_characters() {
-        let grid = |text: &str| {
-            run(
-                &[
-                    ("cannonEnabled", Value::Bool(false)),
-                    ("grid/gridPosition", Value::Vec2([40.0, 30.0])),
-                    ("grid/gridWidth", num(40.0)),
-                    ("grid/gridHeight", num(0.0)),
-                    ("grid/particlesAcross", num(3.0)),
-                    ("grid/particlesDown", num(1.0)),
-                    ("grid/gridParticleRadius", num(16.0)),
-                    ("gravity/gravityForce", num(0.0)),
-                    ("options/gridText", Value::Str(text.into())),
-                ],
-                0.1,
-            )
-        };
-        let dots = grid("");
-        let text = grid("I-O");
-        assert_ne!(dots.data, text.data);
-        // "I" is a vertical bar: ink above and below the grid point, not a round dot.
-        assert!(text.get(20, 26)[3] > 0.3 && text.get(20, 34)[3] > 0.3, "{:?}", text.get(20, 26));
-        // A space leaves its grid point empty.
-        let gap = grid("I O");
-        assert!(gap.get(40, 30)[3] < 0.05);
-        // Cannon text: particles carry the characters in order.
-        let pg = Pg { cannon_text: vec!['A', 'B'], ..bare(1) };
-        assert_eq!(pg.spawn(0).ch, 'A' as u32);
-        assert_eq!(pg.spawn(3).ch, 'B' as u32);
-    }
-
-    #[test]
-    fn layer_map_shows_the_map_layer_at_its_time_offset() {
-        /// A 6×6 map layer whose colour encodes the comp time it was fetched at.
-        struct Clock;
-        impl crate::EffectHost for Clock {
-            fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
-                None
-            }
-            fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
-                None
-            }
-            fn layer_at(&self, _: u64, t: f64, _: bool) -> Option<crate::LayerPixels> {
-                let v = (t as f32 / 4.0).clamp(0.0, 1.0);
-                Some(crate::LayerPixels { buf: Buf { img: Image::filled(6, 6, [v, 0.0, 1.0 - v, 1.0]), offset: [0.0; 2], scale: 1.0 }, size: [6.0, 6.0] })
-            }
-        }
-        let render = |kind: u32, offset: f64| {
-            let vals = [
-                ("cannonEnabled", Value::Bool(false)),
-                ("grid/gridPosition", Value::Vec2([40.0, 30.0])),
-                ("grid/particlesAcross", num(1.0)),
-                ("grid/particlesDown", num(1.0)),
-                ("gravity/gravityForce", num(0.0)),
-                ("layerMap/layerMapLayer", Value::Layer(Some(9))),
-                ("layerMap/timeOffsetType", Value::Enum(kind)),
-                ("layerMap/timeOffset", num(offset)),
-            ];
-            let env = EffectEnv { host: Some(&Clock), comp_time: 1.0, frame_rate: 10.0, ..Default::default() };
-            run_fx("ec.sim.particleplayground", &vals, Image::filled(80, 60, [0.2, 0.2, 0.2, 1.0]), 1.0, env).img
-        };
-        // The particle is a 6×6 copy of the map layer.
-        let rel = render(0, 1.0);
-        assert!(rel.get(40, 30)[3] > 0.99 && rel.get(46, 30)[3] < 0.01);
-        assert!((rel.get(40, 30)[0] - 0.5).abs() < 1e-3, "relative: now + 1 s = 2 s");
-        let abs = render(1, 3.0);
-        assert!((abs.get(40, 30)[0] - 0.75).abs() < 1e-3, "absolute: 3 s");
-    }
-
-    #[test]
-    fn cc_hair_grows_from_opaque_pixels() {
-        let mut img = Image::new(60, 60);
-        for y in 20..40 {
-            for x in 20..40 {
-                img.set(x, y, [0.8, 0.6, 0.4, 1.0]);
-            }
-        }
-        let out = run_fx("ec.sim.cchair", &[("length", num(12.0)), ("density", num(300.0))], img.clone(), 0.0, EffectEnv::default());
-        // Hair reaches beyond the square (above it: hair leans up, then droops).
-        let outside: f32 = (0..60).flat_map(|x| (0..20).map(move |y| (x, y))).map(|(x, y)| out.img.get(x, y)[3]).sum();
-        assert!(outside > 1.0, "{outside}");
-        // Nothing grows from transparent areas far away.
-        assert_eq!(out.img.get(2, 58)[3], 0.0);
-        let again = run_fx("ec.sim.cchair", &[("length", num(12.0)), ("density", num(300.0))], img.clone(), 3.0, EffectEnv::default());
-        assert_eq!(out.img.data, again.img.data);
-        let none = run_fx("ec.sim.cchair", &[("length", num(0.0))], img.clone(), 0.0, EffectEnv::default());
-        assert_eq!(none.img.data, img.data);
-    }
-}
+mod tests;
diff --git a/crates/effects/src/sim3/tests.rs b/crates/effects/src/sim3/tests.rs
new file mode 100644
index 000000000..ffce0ae6d
--- /dev/null
+++ b/crates/effects/src/sim3/tests.rs
@@ -0,0 +1,372 @@
+use super::*;
+use crate::{EffectEnv, MaskShape, run_fx};
+
+fn run(vals: &[(&str, Value)], t: f64) -> Image {
+    run_fx("ec.sim.particleplayground", vals, Image::filled(80, 60, [0.2, 0.2, 0.2, 1.0]), t, EffectEnv::default()).img
+}
+
+fn cannon(t: f64) -> Image {
+    run(&[("cannon/cannonPosition", Value::Vec2([40.0, 50.0])), ("cannon/velocity", num(60.0)), ("gravity/gravityForce", num(30.0))], t)
+}
+
+#[test]
+fn cannon_stream_is_seek_consistent() {
+    let a = cannon(1.0);
+    // Particles replace the layer: some coverage, mostly transparent, red.
+    let cov: f32 = a.data.iter().map(|p| p[3]).sum();
+    assert!(cov > 5.0, "{cov}");
+    assert!(a.data.iter().any(|p| p[3] > 0.5 && p[0] > 0.5 && p[1] < 0.1));
+    // Seek back and forth: the same frame every time.
+    let _ = cannon(2.0);
+    let b = cannon(1.0);
+    assert_eq!(a.data, b.data);
+    let c = cannon(0.5);
+    assert_ne!(a.data, c.data);
+    // Nothing has been fired at time 0.
+    let z = cannon(0.0);
+    assert!(z.data.iter().all(|p| p[3] == 0.0));
+}
+
+#[test]
+fn grid_falls_with_gravity_and_bounces_off_a_wall() {
+    let grid = |t: f64, env: EffectEnv| {
+        run_fx(
+            "ec.sim.particleplayground",
+            &[
+                ("cannonEnabled", Value::Bool(false)),
+                ("grid/gridPosition", Value::Vec2([40.0, 10.0])),
+                ("grid/gridWidth", num(40.0)),
+                ("grid/gridHeight", num(0.0)),
+                ("grid/particlesAcross", num(5.0)),
+                ("grid/particlesDown", num(1.0)),
+                ("gravity/gravityForce", num(100.0)),
+                ("wall/wallBoundary", num(1.0)),
+            ],
+            Image::new(80, 60),
+            t,
+            env,
+        )
+        .img
+    };
+    // Alpha-weighted mean height of the particles.
+    let row_of = |img: &Image| {
+        let (mut s, mut n) = (0.0f64, 0.0f64);
+        for y in 0..60 {
+            for x in 0..80 {
+                let a = img.get(x, y)[3] as f64;
+                s += (y as f64 + 0.5) * a;
+                n += a;
+            }
+        }
+        (s / n.max(1e-9)).round() as i64
+    };
+    let t0 = grid(0.0, EffectEnv::default());
+    let t1 = grid(0.5, EffectEnv::default());
+    assert_eq!(row_of(&t0), 10);
+    // ½ g t² = 12.5 px.
+    assert!((row_of(&t1) - 22).abs() <= 2, "{}", row_of(&t1));
+    // A wall (mask 1) whose floor is at y = 15 keeps them above it.
+    let masks = [MaskShape { name: "w".into(), points: vec![[0.0, 0.0], [80.0, 0.0], [80.0, 15.0], [0.0, 15.0]], closed: true, inverted: false }];
+    let env = EffectEnv { masks: &masks, ..Default::default() };
+    let w = grid(1.5, env);
+    assert!(row_of(&w) <= 16, "{}", row_of(&w));
+}
+
+#[test]
+fn repel_spreads_particles() {
+    let spread = |force: f64| {
+        let img = run(
+            &[
+                ("cannonEnabled", Value::Bool(false)),
+                ("grid/gridPosition", Value::Vec2([40.0, 30.0])),
+                ("grid/gridWidth", num(6.0)),
+                ("grid/gridHeight", num(6.0)),
+                ("grid/particlesAcross", num(3.0)),
+                ("grid/particlesDown", num(3.0)),
+                ("gravity/gravityForce", num(0.0)),
+                ("repel/repelForce", num(force)),
+                ("repel/repelForceRadius", num(20.0)),
+            ],
+            0.5,
+        );
+        let (mut x0, mut x1) = (80, 0);
+        for y in 0..60 {
+            for x in 0..80 {
+                if img.get(x, y)[3] > 0.3 {
+                    x0 = x0.min(x);
+                    x1 = x1.max(x);
+                }
+            }
+        }
+        x1 - x0
+    };
+    assert!(spread(0.2) > spread(0.0) + 4, "{} vs {}", spread(0.2), spread(0.0));
+}
+
+#[test]
+fn property_mapper_and_layer_map_read_layers() {
+    // Without a host, the layer-based features are inert (deterministic output).
+    let a = run(
+        &[
+            ("persistentPropertyMapper/mapRedTo", Value::Enum(8)),
+            ("persistentPropertyMapper/redMin", num(-50.0)),
+            ("persistentPropertyMapper/redMax", num(50.0)),
+        ],
+        0.7,
+    );
+    let b = run(
+        &[
+            ("persistentPropertyMapper/mapRedTo", Value::Enum(8)),
+            ("persistentPropertyMapper/redMin", num(-50.0)),
+            ("persistentPropertyMapper/redMax", num(50.0)),
+        ],
+        0.7,
+    );
+    assert_eq!(a.data, b.data);
+    let st = Pg { persistent: Some(mapper(Image::filled(4, 4, [1.0, 0.0, 0.5, 1.0]), [(15, 0, 0.0, 120.0), (0, 0, 0.0, 1.0), (9, 0, 0.0, 2.0)])), ..bare(1) };
+    let mut s = PgState::default();
+    s.parts.push(PgParticle::new([1.0, 1.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID));
+    st.step(&mut s);
+    // Red 1 → X speed 120 px/s; blue 0.5 → scale 1.
+    assert!((s.parts[0].v[0] - 120.0).abs() < 1e-3);
+    assert!((s.parts[0].scale[0] - 1.0).abs() < 1e-3);
+}
+
+/// A Pg with nothing switched on.
+fn bare(seed: u32) -> Pg {
+    Pg {
+        cannon: false,
+        pos: [0.0; 2],
+        barrel_angle: 0.0,
+        barrel_radius: 0.0,
+        rate: 0.0,
+        dir_spread: 0.0,
+        vel: 0.0,
+        vel_spread: 0.0,
+        color: [1.0; 4],
+        radius: 2.0,
+        cannon_text: vec![],
+        pex_radius: 0.0,
+        pex_dispersion: 0.0,
+        pex_affects: Affects::default(),
+        gravity: [0.0; 2],
+        grav_spread: 0.0,
+        grav_affects: Affects::default(),
+        repel: 0.0,
+        repel_radius: 0.0,
+        repel_affects: Affects::default(),
+        wall: None,
+        wall_affects: Affects::default(),
+        persistent: None,
+        ephemeral: None,
+        seed,
+        bounds: [-1e6, -1e6, 1e6, 1e6],
+    }
+}
+
+fn mapper(img: Image, chans: [(u32, u32, f32, f32); 3]) -> Mapper {
+    Mapper { map: MapImg { img, k: [1.0; 2], o: [0.0; 2] }, chans, affects: Affects::default() }
+}
+
+#[test]
+fn barrel_radius_square_or_disc() {
+    let pg = |r: f32| Pg { cannon: true, barrel_radius: r, ..bare(3) };
+    let (sq, disc) = (pg(10.0), pg(-10.0));
+    let mut corner = false;
+    for id in 0..400 {
+        let a = sq.spawn(id).p;
+        assert!(a[0].abs() <= 10.0 && a[1].abs() <= 10.0);
+        // A square barrel fills its corners (both offsets in use, not a line).
+        corner |= a[0].abs() > 7.5 && a[1].abs() > 7.5;
+        let b = disc.spawn(id).p;
+        assert!(b[0].hypot(b[1]) <= 10.0 + 1e-4);
+    }
+    assert!(corner);
+    // Radius 0: every particle starts at the cannon position.
+    assert_eq!(pg(0.0).spawn(5).p, [0.0, 0.0]);
+}
+
+#[test]
+fn mapper_drives_position_and_opacity_in_ae_order() {
+    let st = Pg { persistent: Some(mapper(Image::filled(4, 4, [1.0, 0.5, 0.25, 1.0]), [(12, 0, 0.0, 30.0), (20, 0, 0.0, 1.0), (4, 0, 0.0, 1.0)])), ..bare(1) };
+    assert_eq!(MAP_TARGETS[12], "X");
+    assert_eq!(MAP_TARGETS[20], "Opacity");
+    assert_eq!(MAP_TARGETS[26], "Scale Speed");
+    let mut s = PgState::default();
+    s.parts.push(PgParticle::new([1.0, 1.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID));
+    st.step(&mut s);
+    assert!((s.parts[0].p[0] - 30.0).abs() < 1e-3, "{:?}", s.parts[0].p);
+    assert!((s.parts[0].c[3] - 0.5).abs() < 1e-3);
+    assert!((s.parts[0].friction - 0.25).abs() < 1e-3);
+}
+
+#[test]
+fn ephemeral_mapper_holds_for_one_step_with_operators() {
+    // Ephemeral X Speed = 60 px/s (Set): the particle moves, but keeps no velocity.
+    let st = Pg { ephemeral: Some(mapper(Image::filled(4, 4, [1.0, 1.0, 1.0, 1.0]), [(15, 0, 0.0, 60.0), (0, 0, 0.0, 1.0), (0, 0, 0.0, 1.0)])), ..bare(1) };
+    let mut s = PgState::default();
+    s.parts.push(PgParticle::new([1.0, 1.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID));
+    st.step(&mut s);
+    assert!((s.parts[0].p[0] - 2.0).abs() < 1e-4, "{:?}", s.parts[0].p);
+    assert!(s.parts[0].v[0].abs() < 1e-4);
+    // Operators: Add / Multiply / Max on the particle's own value.
+    let op = |o: u32, cur: f32| {
+        let m = mapper(Image::filled(4, 4, [1.0, 1.0, 1.0, 1.0]), [(21, o, 0.0, 3.0), (0, 0, 0.0, 1.0), (0, 0, 0.0, 1.0)]);
+        let mut q = PgParticle::new([1.0, 1.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID);
+        q.mass = cur;
+        m.apply(&mut q);
+        q.mass
+    };
+    assert_eq!(MAP_OPERATORS[1], "Add");
+    assert!((op(1, 2.0) - 5.0).abs() < 1e-5);
+    assert!((op(4, 2.0) - 6.0).abs() < 1e-5);
+    assert!((op(6, 5.0) - 5.0).abs() < 1e-5);
+    assert!((op(2, 5.0) - 2.0).abs() < 1e-5, "Difference");
+}
+
+#[test]
+fn affects_select_by_source_age_and_characters() {
+    let mut q = PgParticle::new([0.0; 2], [0.0; 2], [1.0; 4], 2.0, 0, SRC_CANNON);
+    let a = Affects { from: 2, ..Default::default() };
+    assert_eq!(a.weight(&q), 0.0, "grid only");
+    q.src = SRC_GRID;
+    assert_eq!(a.weight(&q), 1.0);
+    let older = Affects { age: 1.0, ..Default::default() };
+    q.age = 0.5;
+    assert_eq!(older.weight(&q), 0.0);
+    q.age = 1.5;
+    assert_eq!(older.weight(&q), 1.0);
+    let younger = Affects { age: -1.0, feather: 1.0, ..Default::default() };
+    q.age = 1.0;
+    assert!((younger.weight(&q) - 0.5).abs() < 1e-5, "feathered");
+    let chars = Affects { chars: vec!['A', 'B'], ..Default::default() };
+    q.ch = 'B' as u32;
+    assert_eq!(chars.weight(&q), 1.0);
+    q.ch = 'C' as u32;
+    assert_eq!(chars.weight(&q), 0.0);
+    // Gravity restricted to the cannon leaves grid particles in place.
+    let st = Pg { gravity: [0.0, 100.0], grav_affects: Affects { from: 1, ..Default::default() }, ..bare(1) };
+    let mut s = PgState::default();
+    s.parts.push(PgParticle::new([5.0, 5.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID));
+    s.parts.push(PgParticle::new([5.0, 5.0], [0.0; 2], [1.0; 4], 2.0, 1, SRC_CANNON));
+    for _ in 0..10 {
+        st.step(&mut s);
+    }
+    assert_eq!(s.parts[0].p, [5.0, 5.0]);
+    assert!(s.parts[1].p[1] > 5.0);
+}
+
+#[test]
+fn particle_exploder_bursts_big_particles() {
+    let st = Pg { pex_radius: 2.0, pex_dispersion: 30.0, ..bare(1) };
+    let mut s = PgState::default();
+    s.parts.push(PgParticle::new([50.0, 50.0], [0.0; 2], [1.0; 4], 6.0, 0, SRC_GRID));
+    s.next_id = 1;
+    st.step(&mut s);
+    assert_eq!(s.parts.len(), 9, "(6/2)² new particles");
+    assert!(s.parts.iter().all(|q| q.r == 2.0 && q.src == SRC_PARTICLE_EXPLODER));
+    st.step(&mut s);
+    assert_eq!(s.parts.len(), 9, "new particles do not burst again");
+    // Lifespan from a mapper removes particles once they are older.
+    let life = Pg { persistent: Some(mapper(Image::filled(4, 4, [1.0; 4]), [(22, 0, 0.0, 0.05), (0, 0, 0.0, 1.0), (0, 0, 0.0, 1.0)])), ..bare(1) };
+    let mut s = PgState::default();
+    s.parts.push(PgParticle::new([1.0, 1.0], [0.0; 2], [1.0; 4], 2.0, 0, SRC_GRID));
+    for _ in 0..2 {
+        life.step(&mut s);
+    }
+    assert_eq!(s.parts.len(), 1);
+    for _ in 0..3 {
+        life.step(&mut s);
+    }
+    assert!(s.parts.is_empty());
+}
+
+#[test]
+fn text_particles_draw_characters() {
+    let grid = |text: &str| {
+        run(
+            &[
+                ("cannonEnabled", Value::Bool(false)),
+                ("grid/gridPosition", Value::Vec2([40.0, 30.0])),
+                ("grid/gridWidth", num(40.0)),
+                ("grid/gridHeight", num(0.0)),
+                ("grid/particlesAcross", num(3.0)),
+                ("grid/particlesDown", num(1.0)),
+                ("grid/gridParticleRadius", num(16.0)),
+                ("gravity/gravityForce", num(0.0)),
+                ("options/gridText", Value::Str(text.into())),
+            ],
+            0.1,
+        )
+    };
+    let dots = grid("");
+    let text = grid("I-O");
+    assert_ne!(dots.data, text.data);
+    // "I" is a vertical bar: ink above and below the grid point, not a round dot.
+    assert!(text.get(20, 26)[3] > 0.3 && text.get(20, 34)[3] > 0.3, "{:?}", text.get(20, 26));
+    // A space leaves its grid point empty.
+    let gap = grid("I O");
+    assert!(gap.get(40, 30)[3] < 0.05);
+    // Cannon text: particles carry the characters in order.
+    let pg = Pg { cannon_text: vec!['A', 'B'], ..bare(1) };
+    assert_eq!(pg.spawn(0).ch, 'A' as u32);
+    assert_eq!(pg.spawn(3).ch, 'B' as u32);
+}
+
+#[test]
+fn layer_map_shows_the_map_layer_at_its_time_offset() {
+    /// A 6×6 map layer whose colour encodes the comp time it was fetched at.
+    struct Clock;
+    impl crate::EffectHost for Clock {
+        fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
+            None
+        }
+        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+            None
+        }
+        fn layer_at(&self, _: u64, t: f64, _: bool) -> Option<crate::LayerPixels> {
+            let v = (t as f32 / 4.0).clamp(0.0, 1.0);
+            Some(crate::LayerPixels { buf: Buf { img: Image::filled(6, 6, [v, 0.0, 1.0 - v, 1.0]), offset: [0.0; 2], scale: 1.0 }, size: [6.0, 6.0] })
+        }
+    }
+    let render = |kind: u32, offset: f64| {
+        let vals = [
+            ("cannonEnabled", Value::Bool(false)),
+            ("grid/gridPosition", Value::Vec2([40.0, 30.0])),
+            ("grid/particlesAcross", num(1.0)),
+            ("grid/particlesDown", num(1.0)),
+            ("gravity/gravityForce", num(0.0)),
+            ("layerMap/layerMapLayer", Value::Layer(Some(9))),
+            ("layerMap/timeOffsetType", Value::Enum(kind)),
+            ("layerMap/timeOffset", num(offset)),
+        ];
+        let env = EffectEnv { host: Some(&Clock), comp_time: 1.0, frame_rate: 10.0, ..Default::default() };
+        run_fx("ec.sim.particleplayground", &vals, Image::filled(80, 60, [0.2, 0.2, 0.2, 1.0]), 1.0, env).img
+    };
+    // The particle is a 6×6 copy of the map layer.
+    let rel = render(0, 1.0);
+    assert!(rel.get(40, 30)[3] > 0.99 && rel.get(46, 30)[3] < 0.01);
+    assert!((rel.get(40, 30)[0] - 0.5).abs() < 1e-3, "relative: now + 1 s = 2 s");
+    let abs = render(1, 3.0);
+    assert!((abs.get(40, 30)[0] - 0.75).abs() < 1e-3, "absolute: 3 s");
+}
+
+#[test]
+fn cc_hair_grows_from_opaque_pixels() {
+    let mut img = Image::new(60, 60);
+    for y in 20..40 {
+        for x in 20..40 {
+            img.set(x, y, [0.8, 0.6, 0.4, 1.0]);
+        }
+    }
+    let out = run_fx("ec.sim.cchair", &[("length", num(12.0)), ("density", num(300.0))], img.clone(), 0.0, EffectEnv::default());
+    // Hair reaches beyond the square (above it: hair leans up, then droops).
+    let outside: f32 = (0..60).flat_map(|x| (0..20).map(move |y| (x, y))).map(|(x, y)| out.img.get(x, y)[3]).sum();
+    assert!(outside > 1.0, "{outside}");
+    // Nothing grows from transparent areas far away.
+    assert_eq!(out.img.get(2, 58)[3], 0.0);
+    let again = run_fx("ec.sim.cchair", &[("length", num(12.0)), ("density", num(300.0))], img.clone(), 3.0, EffectEnv::default());
+    assert_eq!(out.img.data, again.img.data);
+    let none = run_fx("ec.sim.cchair", &[("length", num(0.0))], img.clone(), 0.0, EffectEnv::default());
+    assert_eq!(none.img.data, img.data);
+}
diff --git a/crates/effects/src/warp_stab.rs b/crates/effects/src/warp_stab.rs
index f850bdcf3..226654a04 100644
--- a/crates/effects/src/warp_stab.rs
+++ b/crates/effects/src/warp_stab.rs
@@ -453,7 +453,7 @@ fn render(ctx: &EffectCtx, buf: Buf) -> Buf {
     });
     let need = need_m.into_inner().unwrap_or_else(std::sync::PoisonError::into_inner);
     if synth && need.iter().any(|w| *w > 0.0) {
-        synthesize(ctx, &a, k, &src_of, &crop, sc, &mut out, &need);
+        synthesize(ctx, &a, k, &SynthesisGrid { src_of: &src_of, crop: &crop, scale: sc }, &mut out, &need);
     }
     if b(ctx.params, "advanced/showTrackPoints") {
         let r = (2.5 * f(ctx.params, "advanced/trackPointSize") / 100.0 * sc).max(0.5);
@@ -465,19 +465,16 @@ fn render(ctx: &EffectCtx, buf: Buf) -> Buf {
     Buf { img: out, offset: [0.0; 2], scale: sc }
 }
 
-/// Fill the pixels flagged in `need` (weight = how much synthesized content they take) from
-/// neighbouring frames, nearest first.
-#[allow(clippy::too_many_arguments)]
-fn synthesize(
-    ctx: &EffectCtx,
-    a: &WarpAnalysis,
-    k: usize,
-    src_of: &(dyn Fn([f64; 2]) -> [f64; 2] + Sync),
-    crop: &[f64; 4],
-    sc: f64,
-    out: &mut Image,
-    need: &[f32],
-) {
+/// Maps an output sample into the uncropped source grid shared by neighbouring frames.
+struct SynthesisGrid<'a> {
+    src_of: &'a (dyn Fn([f64; 2]) -> [f64; 2] + Sync),
+    crop: &'a [f64; 4],
+    scale: f64,
+}
+
+/// Fill the pixels flagged in `need` from neighbouring frames, nearest first.
+fn synthesize(ctx: &EffectCtx, a: &WarpAnalysis, k: usize, grid: &SynthesisGrid<'_>, out: &mut Image, need: &[f32]) {
+    let SynthesisGrid { src_of, crop, scale: sc } = *grid;
     let Some(host) = ctx.env.host else { return };
     let n = a.frames.len();
     let range = ((f(ctx.params, "advanced/synthesizeInputRange").max(0.0) / a.frame_duration.max(1e-6)).round() as usize).min(60);
diff --git a/crates/engine/src/analysis.rs b/crates/engine/src/analysis.rs
new file mode 100644
index 000000000..fa2b8b4ec
--- /dev/null
+++ b/crates/engine/src/analysis.rs
@@ -0,0 +1,6 @@
+pub mod camera_track;
+pub mod mask_track;
+pub mod models;
+pub mod roto;
+pub mod tracking;
+pub mod warp;
diff --git a/crates/engine/src/camera_track.rs b/crates/engine/src/analysis/camera_track.rs
similarity index 100%
rename from crates/engine/src/camera_track.rs
rename to crates/engine/src/analysis/camera_track.rs
diff --git a/crates/engine/src/mask_track.rs b/crates/engine/src/analysis/mask_track.rs
similarity index 100%
rename from crates/engine/src/mask_track.rs
rename to crates/engine/src/analysis/mask_track.rs
diff --git a/crates/engine/src/models.rs b/crates/engine/src/analysis/models.rs
similarity index 100%
rename from crates/engine/src/models.rs
rename to crates/engine/src/analysis/models.rs
diff --git a/crates/engine/src/roto.rs b/crates/engine/src/analysis/roto.rs
similarity index 98%
rename from crates/engine/src/roto.rs
rename to crates/engine/src/analysis/roto.rs
index d9ce6e5af..813561969 100644
--- a/crates/engine/src/roto.rs
+++ b/crates/engine/src/analysis/roto.rs
@@ -450,7 +450,18 @@ async fn run_work(w: Work, shared: &RotoShared) {
             (RotoTask::Propagate, true) => om::ensure(&w.params, w.size, w.fps, *f, model.clone(), &mut get, &cancel).is_some(),
             (RotoTask::Freeze, true) => {
                 let img = get(*f);
-                match img.map(|img| (om::frame_matte(&w.params, w.size, w.fps, *f, 1.0, &img, model.clone(), &mut get, &cancel), img)) {
+                match img.map(|img| {
+                    (
+                        om::frame_matte(
+                            &w.params,
+                            &om::MatteFrame { layer_size: w.size, fps: w.fps, frame: *f, scale: 1.0, img: &img },
+                            model.clone(),
+                            &mut get,
+                            &cancel,
+                        ),
+                        img,
+                    )
+                }) {
                     Some((om::FrameMatte::Alpha(a), img)) => {
                         frozen.size = [img.width as usize, img.height as usize];
                         frozen.frames.insert(*f, fx::freeze_frame(&a, &[]));
diff --git a/crates/engine/src/tracking.rs b/crates/engine/src/analysis/tracking.rs
similarity index 100%
rename from crates/engine/src/tracking.rs
rename to crates/engine/src/analysis/tracking.rs
diff --git a/crates/engine/src/warp.rs b/crates/engine/src/analysis/warp.rs
similarity index 100%
rename from crates/engine/src/warp.rs
rename to crates/engine/src/analysis/warp.rs
diff --git a/crates/engine/src/background.rs b/crates/engine/src/background.rs
new file mode 100644
index 000000000..d4d404d95
--- /dev/null
+++ b/crates/engine/src/background.rs
@@ -0,0 +1,3 @@
+pub mod jobs;
+pub mod offload;
+pub mod remote;
diff --git a/crates/engine/src/jobs.rs b/crates/engine/src/background/jobs.rs
similarity index 100%
rename from crates/engine/src/jobs.rs
rename to crates/engine/src/background/jobs.rs
diff --git a/crates/engine/src/offload.rs b/crates/engine/src/background/offload.rs
similarity index 72%
rename from crates/engine/src/offload.rs
rename to crates/engine/src/background/offload.rs
index 135822d57..23cff4da6 100644
--- a/crates/engine/src/offload.rs
+++ b/crates/engine/src/background/offload.rs
@@ -992,317 +992,4 @@ pub(crate) fn merge_group(base: &PropGroup, live: &PropGroup, result: &PropGroup
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn round<T: Serialize + for<'de> Deserialize<'de>>(v: &T) -> String {
-        let a = serde_json::to_string(v).unwrap();
-        let back: T = serde_json::from_str(&a).unwrap();
-        let b = serde_json::to_string(&back).unwrap();
-        assert_eq!(a, b);
-        a
-    }
-
-    /// A group with properties `a` (uid 2) and `b` (uid 3) and a sub-group (uid 4) holding `c`
-    /// (uid 5).
-    fn group() -> PropGroup {
-        use effectcraft_keyframe::Value as KV;
-        use effectcraft_project::{Node, Property};
-        let mut sub = PropGroup::new(4, "sub", "Sub");
-        sub.children.push(Node::Prop(Property::new(5, "c", "C", KV::Scalar(0.0))));
-        let mut g = PropGroup::new(1, "fx", "Effect");
-        g.children.push(Node::Prop(Property::new(2, "a", "A", KV::Scalar(0.0))));
-        g.children.push(Node::Prop(Property::new(3, "b", "B", KV::Scalar(0.0))));
-        g.children.push(Node::Group(sub));
-        g
-    }
-
-    fn set(g: &mut PropGroup, uid: Uid, v: f64) {
-        g.find_mut(uid).unwrap().value = effectcraft_keyframe::Value::Scalar(v);
-    }
-
-    fn get(g: &PropGroup, uid: Uid) -> f64 {
-        match g.find(uid).unwrap().value {
-            effectcraft_keyframe::Value::Scalar(v) => v,
-            ref v => panic!("{v:?}"),
-        }
-    }
-
-    #[test]
-    fn analysis_results_merge_with_edits_made_meanwhile() {
-        use effectcraft_project::Node;
-        let base = group();
-        // The user changes `a` and switches the effect off; the analysis writes `b` and `c`.
-        let mut live = base.clone();
-        set(&mut live, 2, 1.0);
-        live.enabled = false;
-        let mut result = base.clone();
-        set(&mut result, 3, 2.0);
-        set(&mut result, 5, 3.0);
-        let m = merge_group(&base, &live, &result).unwrap();
-        assert_eq!((get(&m, 2), get(&m, 3), get(&m, 5), m.enabled), (1.0, 2.0, 3.0, false));
-        // Unchanged on either side: the other side wins whole.
-        assert_eq!(merge_group(&base, &base, &result).unwrap(), result);
-        assert_eq!(merge_group(&base, &live, &base).unwrap(), live);
-        // Both changed `b`, differently: a conflict (nothing is applied). The same way: fine.
-        let mut both = live.clone();
-        set(&mut both, 3, 9.0);
-        assert!(merge_group(&base, &both, &result).is_none());
-        set(&mut both, 3, 2.0);
-        assert_eq!(get(&merge_group(&base, &both, &result).unwrap(), 3), 2.0);
-        // The analysis adds a child (a result group) while the user edits `a`: both kept.
-        let mut added = result.clone();
-        added.children.push(Node::Group(PropGroup::new(6, "out", "Output")));
-        let m = merge_group(&base, &live, &added).unwrap();
-        assert!(m.find_group(6).is_some() && get(&m, 2) == 1.0);
-        // The analysis drops the sub-group the user didn't touch: dropped.
-        let mut dropped = result.clone();
-        dropped.children.retain(|n| !matches!(n, Node::Group(g) if g.uid == 4));
-        let m = merge_group(&base, &live, &dropped).unwrap();
-        assert!(m.find_group(4).is_none() && get(&m, 2) == 1.0);
-        // …but if the user changed something in it, that's a conflict.
-        let mut touched = live.clone();
-        set(&mut touched, 5, 7.0);
-        assert!(merge_group(&base, &touched, &dropped).is_none());
-    }
-
-    #[test]
-    fn protocol_round_trips() {
-        let mut s = Session::default();
-        s.execute("file.openDemoProject", serde_json::json!({})).unwrap();
-        let comp = s.active_comp_id().unwrap();
-        s.execute("renderQueue.add", serde_json::json!({})).unwrap();
-        let item = s.project.render_queue[0].clone();
-        let reqs = [
-            WorkerJob::Render { items: vec![vec![(item.clone(), "/out.gif".into())]] },
-            WorkerJob::Warp { comp, layer: LayerId(3), effect: 9 },
-            WorkerJob::WarpPlan { comp, layer: LayerId(3), effect: 9, time: Tick::from_seconds_f64(0.5) },
-            WorkerJob::RotoFreeze { comp, layer: LayerId(3), effect: 9 },
-            WorkerJob::Camera { comp, layer: LayerId(3), effect: 9 },
-            WorkerJob::RotoPropagate { comp, layer: LayerId(3), effect: 9, direction: crate::roto::Direction::Forward },
-            WorkerJob::Track {
-                comp,
-                layer: LayerId(1),
-                tracker: 4,
-                direction: crate::tracking::Direction::Backward,
-                settings: TrackerSettings::default(),
-                points: vec![PointValues {
-                    uid: 5,
-                    spec: effectcraft_track::PointSpec { center: [1.0, 2.0], feature_size: [3.0, 4.0], search_offset: [0.5, 0.0], search_size: [9.0, 9.0] },
-                    attach_offset: [0.25, -1.0],
-                }],
-                times: vec![Tick::ZERO, Tick::from_seconds_f64(0.5)],
-            },
-            WorkerJob::MaskTrack {
-                comp,
-                layer: LayerId(2),
-                mask: 7,
-                direction: crate::tracking::Direction::Forward,
-                path: ShapePath::ellipse([10.0, 20.0], 5.0, 6.0),
-                method: MaskMethod::Perspective,
-                times: vec![Tick::from_seconds_f64(1.0)],
-            },
-            WorkerJob::ContentFill {
-                plan: Box::new(crate::commands::content_fill::FillPlan {
-                    comp,
-                    layer: LayerId(2),
-                    name: "Clip".into(),
-                    width: 4,
-                    height: 3,
-                    times: vec![Tick::ZERO],
-                    method: "object".into(),
-                    lighting: 0.5,
-                    expand: 1,
-                    reference: Some((LayerId(1), Tick::ZERO)),
-                    dir: "/Fill/Clip_Fill_1".into(),
-                }),
-            },
-        ];
-        for job in reqs {
-            let kind = job.kind();
-            let req = WorkerRequest { id: 42, project: s.project.to_json(), files: footage_files(&s.project), job };
-            let t = round(&req);
-            assert!(t.contains("\"kind\":"), "{kind:?}");
-            let back: WorkerRequest = serde_json::from_str(&t).unwrap();
-            assert_eq!(back.job.kind(), kind);
-            assert_eq!(Project::from_json(&back.project).unwrap(), *s.project);
-        }
-        let g = s.active_comp().unwrap().layers[0].props.clone();
-        for r in [
-            WorkerReply::Render { state: JobState { current: Some(3), done: 4, total: 10, items_total: 1, ..Default::default() } },
-            WorkerReply::Item { update: ItemUpdate::Started { id: 3, unix: 1_700_000_000 } },
-            WorkerReply::Item { update: ItemUpdate::Finished { id: 3, status: RenderStatus::Failed("x".into()), seconds: 1.5, output: Some("/a.gif".into()) } },
-            WorkerReply::Progress { done: 1, total: 2 },
-            WorkerReply::WarpPlan {
-                key: [1, u64::MAX],
-                summary: Box::new(effectcraft_effects::warp_stab::PlanSummary {
-                    warps: vec![[[1.0, 0.0, 2.5], [0.0, 1.0, -1.0], [0.0, 0.0, 1.0]]],
-                    auto_scale: 1.08,
-                    crop: Some([1.0, 2.0, 300.0, 200.0]),
-                    valid_fraction: 0.9,
-                }),
-            },
-            WorkerReply::Group { comp, layer: LayerId(1), group: Box::new(g), message: "ok".into() },
-            WorkerReply::Segs { segs: vec![SegData::new(5, &effectcraft_track::roto::FrameSeg::empty(4, 3))] },
-            WorkerReply::Fill {
-                plan: Box::new(crate::commands::content_fill::FillPlan {
-                    comp,
-                    layer: LayerId(2),
-                    name: "Clip".into(),
-                    width: 4,
-                    height: 3,
-                    times: vec![Tick::ZERO],
-                    method: "object".into(),
-                    lighting: 0.5,
-                    expand: 1,
-                    reference: Some((LayerId(1), Tick::ZERO)),
-                    dir: "/Fill/Clip_Fill_1".into(),
-                }),
-                files: vec!["/Fill/Clip_Fill_1/fill_00000.png".into()],
-            },
-            WorkerReply::Failed { error: "boom".into() },
-            WorkerReply::Done,
-        ] {
-            let t = round(&r);
-            assert!(t.starts_with("{\"type\":"), "{t}");
-        }
-    }
-
-    /// An [`Offload`] that runs the job right away in a second session, through JSON (what a
-    /// Web Worker does, minus the threads).
-    struct Inline;
-    impl Offload for Inline {
-        fn start(&self, req: WorkerRequest, inbox: Arc<Inbox>) -> Result<(), String> {
-            let req: WorkerRequest = serde_json::from_str(&serde_json::to_string(&req).unwrap()).unwrap();
-            let mut w = Session { exporter: Some(Arc::new(crate::rq_tests::MockExporter { log: Default::default() })), ..Default::default() };
-            let post: Post = Rc::new(move |r| inbox.push(serde_json::from_str(&serde_json::to_string(&r).unwrap()).unwrap()));
-            run_request(&mut w, req, &post);
-            Ok(())
-        }
-        fn cancel(&self, _: u64) {}
-    }
-
-    #[test]
-    fn render_runs_through_the_offload() {
-        let mut s = Session {
-            exporter: Some(Arc::new(crate::rq_tests::MockExporter { log: Default::default() })),
-            offload: Some(Arc::new(Inline)),
-            ..Default::default()
-        };
-        s.execute("file.openDemoProject", serde_json::json!({})).unwrap();
-        s.execute("renderQueue.add", serde_json::json!({"output": "/x.gif"})).unwrap();
-        let ids = s.start_render(false).unwrap();
-        // (the inline offload has replied already; replies are applied when polled)
-        s.poll_render();
-        assert!(s.render_job.is_none());
-        let it = s.project.render_queue.iter().find(|i| i.id == ids[0]).unwrap();
-        assert_eq!(it.status, RenderStatus::Done, "{:?}", it.status);
-        assert!(it.last_output.as_deref().is_some_and(|o| o.ends_with("x.gif")));
-        // `wait` renders inline.
-        s.execute("renderQueue.add", serde_json::json!({"output": "/y.gif"})).unwrap();
-        s.start_render(true).unwrap();
-        assert!(s.render_job.is_none() || s.render_job.as_ref().unwrap().remote.is_none());
-    }
-
-    /// Runs jobs in a session sharing `footage` (the synthetic clip of the tracking tests).
-    struct InlineWith(Arc<dyn effectcraft_render::FootageSource>);
-    impl Offload for InlineWith {
-        fn start(&self, req: WorkerRequest, inbox: Arc<Inbox>) -> Result<(), String> {
-            let req: WorkerRequest = serde_json::from_str(&serde_json::to_string(&req).unwrap()).unwrap();
-            let mut w = Session { footage: self.0.clone(), ..Default::default() };
-            let post: Post = Rc::new(move |r| inbox.push(serde_json::from_str(&serde_json::to_string(&r).unwrap()).unwrap()));
-            run_request(&mut w, req, &post);
-            Ok(())
-        }
-        fn cancel(&self, _: u64) {}
-    }
-
-    /// Never replies (a job still running); records cancellations.
-    #[derive(Default)]
-    struct Hanging(Mutex<Vec<u64>>);
-    impl Offload for Hanging {
-        fn start(&self, _: WorkerRequest, _: Arc<Inbox>) -> Result<(), String> {
-            Ok(())
-        }
-        fn cancel(&self, id: u64) {
-            self.0.lock().unwrap().push(id);
-        }
-    }
-
-    fn pose(f: u32) -> ([f64; 2], f64, f64) {
-        ([150.0 + 2.0 * f as f64, 110.0 + 1.0 * f as f64], 0.0, 1.0)
-    }
-
-    #[test]
-    fn track_analysis_runs_through_the_offload_as_one_undo_step() {
-        let (mut s, clip, _) = crate::tests_track::setup(crate::tests_track::patch_frames(pose));
-        s.offload = Some(Arc::new(InlineWith(s.footage.clone())));
-        s.execute("track.motion", serde_json::json!({})).unwrap();
-        s.execute("track.setPoint", serde_json::json!({"point": 1, "center": pose(0).0, "featureSize": [36, 36], "searchSize": [80, 80]})).unwrap();
-        let undo = s.history.undo.len();
-        s.execute("track.analyze", serde_json::json!({"direction": "forward"})).unwrap();
-        assert!(s.is_tracking() && s.track_job.is_none(), "offloaded, not on a thread");
-        assert!(s.track_progress().is_some());
-        assert!(s.poll_offload());
-        assert!(!s.is_tracking() && s.offloaded.is_empty());
-        let l = s.active_comp().unwrap().layer(clip).unwrap();
-        let tp = l.trackers().next().unwrap().0.track_points().next().unwrap().clone();
-        let fc = tp.get("featureCenter").unwrap();
-        assert_eq!(fc.keys.len(), 25);
-        let v = fc.value_at(crate::tests_track::frame_time(12)).as_vec2();
-        assert!((v[0] - pose(12).0[0]).abs() < 0.3 && (v[1] - pose(12).0[1]).abs() < 0.3, "{v:?}");
-        assert_eq!(s.history.undo.len(), undo + 1);
-        assert_eq!(s.history.undo.last().unwrap().0, "Analyze Track");
-        assert!(s.events.iter().any(|e| matches!(e, Event::Toast { message, error: false } if message.starts_with("Tracked"))));
-        assert!(s.undo());
-        let l = s.active_comp().unwrap().layer(clip).unwrap();
-        assert!(l.trackers().next().unwrap().0.track_points().next().unwrap().get("featureCenter").unwrap().keys.is_empty());
-        // `wait` runs inline.
-        s.redo();
-        s.execute("track.analyze", serde_json::json!({"direction": "forward", "wait": true})).ok();
-        assert!(s.offloaded.is_empty());
-    }
-
-    #[test]
-    fn cancelling_offloaded_jobs() {
-        let (mut s, _, _) = crate::tests_track::setup(crate::tests_track::patch_frames(pose));
-        let off = Arc::new(Hanging::default());
-        s.offload = Some(off.clone());
-        s.exporter = Some(Arc::new(crate::rq_tests::MockExporter { log: Default::default() }));
-        // Analysis: stopping drops the job, nothing is written.
-        s.execute("track.motion", serde_json::json!({})).unwrap();
-        let rev = s.revision;
-        s.execute("track.analyze", serde_json::json!({})).unwrap();
-        assert!(s.is_tracking());
-        assert!(s.execute("track.analyze", serde_json::json!({})).is_err(), "one at a time");
-        assert!(s.stop_track());
-        s.poll_offload();
-        assert!(!s.is_tracking());
-        assert_eq!(off.0.lock().unwrap().len(), 1);
-        assert!(s.events.iter().any(|e| matches!(e, Event::Toast { message, .. } if message.contains("stopped"))));
-        assert!(s.revision > rev);
-        // Render: the queued items become User Stopped.
-        s.execute("renderQueue.add", serde_json::json!({"output": "/a.gif"})).unwrap();
-        let ids = s.start_render(false).unwrap();
-        assert!(s.is_rendering());
-        assert!(s.stop_render());
-        s.poll_render();
-        assert!(!s.is_rendering());
-        assert_eq!(off.0.lock().unwrap().len(), 2);
-        let it = s.project.render_queue.iter().find(|i| i.id == ids[0]).unwrap();
-        assert_eq!(it.status, RenderStatus::UserStopped);
-    }
-
-    #[test]
-    fn progress_hook_is_scoped() {
-        report(1, 2); // no hook: nothing happens
-        let seen = Rc::new(RefCell::new(vec![]));
-        let s2 = seen.clone();
-        effectcraft_render::passes::block_on(with_hook(Box::new(move |d, t| s2.borrow_mut().push((d, t))), async {
-            report(1, 3);
-            report(2, 3);
-        }));
-        report(3, 3);
-        assert_eq!(*seen.borrow(), vec![(1, 3), (2, 3)]);
-    }
-}
+mod tests;
diff --git a/crates/engine/src/background/offload/tests.rs b/crates/engine/src/background/offload/tests.rs
new file mode 100644
index 000000000..c08623189
--- /dev/null
+++ b/crates/engine/src/background/offload/tests.rs
@@ -0,0 +1,309 @@
+use super::*;
+
+fn round<T: Serialize + for<'de> Deserialize<'de>>(v: &T) -> String {
+    let a = serde_json::to_string(v).unwrap();
+    let back: T = serde_json::from_str(&a).unwrap();
+    let b = serde_json::to_string(&back).unwrap();
+    assert_eq!(a, b);
+    a
+}
+
+/// A group with properties `a` (uid 2) and `b` (uid 3) and a sub-group (uid 4) holding `c`
+/// (uid 5).
+fn group() -> PropGroup {
+    use effectcraft_keyframe::Value as KV;
+    use effectcraft_project::{Node, Property};
+    let mut sub = PropGroup::new(4, "sub", "Sub");
+    sub.children.push(Node::Prop(Property::new(5, "c", "C", KV::Scalar(0.0))));
+    let mut g = PropGroup::new(1, "fx", "Effect");
+    g.children.push(Node::Prop(Property::new(2, "a", "A", KV::Scalar(0.0))));
+    g.children.push(Node::Prop(Property::new(3, "b", "B", KV::Scalar(0.0))));
+    g.children.push(Node::Group(sub));
+    g
+}
+
+fn set(g: &mut PropGroup, uid: Uid, v: f64) {
+    g.find_mut(uid).unwrap().value = effectcraft_keyframe::Value::Scalar(v);
+}
+
+fn get(g: &PropGroup, uid: Uid) -> f64 {
+    match g.find(uid).unwrap().value {
+        effectcraft_keyframe::Value::Scalar(v) => v,
+        ref v => panic!("{v:?}"),
+    }
+}
+
+#[test]
+fn analysis_results_merge_with_edits_made_meanwhile() {
+    use effectcraft_project::Node;
+    let base = group();
+    // The user changes `a` and switches the effect off; the analysis writes `b` and `c`.
+    let mut live = base.clone();
+    set(&mut live, 2, 1.0);
+    live.enabled = false;
+    let mut result = base.clone();
+    set(&mut result, 3, 2.0);
+    set(&mut result, 5, 3.0);
+    let m = merge_group(&base, &live, &result).unwrap();
+    assert_eq!((get(&m, 2), get(&m, 3), get(&m, 5), m.enabled), (1.0, 2.0, 3.0, false));
+    // Unchanged on either side: the other side wins whole.
+    assert_eq!(merge_group(&base, &base, &result).unwrap(), result);
+    assert_eq!(merge_group(&base, &live, &base).unwrap(), live);
+    // Both changed `b`, differently: a conflict (nothing is applied). The same way: fine.
+    let mut both = live.clone();
+    set(&mut both, 3, 9.0);
+    assert!(merge_group(&base, &both, &result).is_none());
+    set(&mut both, 3, 2.0);
+    assert_eq!(get(&merge_group(&base, &both, &result).unwrap(), 3), 2.0);
+    // The analysis adds a child (a result group) while the user edits `a`: both kept.
+    let mut added = result.clone();
+    added.children.push(Node::Group(PropGroup::new(6, "out", "Output")));
+    let m = merge_group(&base, &live, &added).unwrap();
+    assert!(m.find_group(6).is_some() && get(&m, 2) == 1.0);
+    // The analysis drops the sub-group the user didn't touch: dropped.
+    let mut dropped = result.clone();
+    dropped.children.retain(|n| !matches!(n, Node::Group(g) if g.uid == 4));
+    let m = merge_group(&base, &live, &dropped).unwrap();
+    assert!(m.find_group(4).is_none() && get(&m, 2) == 1.0);
+    // …but if the user changed something in it, that's a conflict.
+    let mut touched = live.clone();
+    set(&mut touched, 5, 7.0);
+    assert!(merge_group(&base, &touched, &dropped).is_none());
+}
+
+#[test]
+fn protocol_round_trips() {
+    let mut s = Session::default();
+    s.execute("file.openDemoProject", serde_json::json!({})).unwrap();
+    let comp = s.active_comp_id().unwrap();
+    s.execute("renderQueue.add", serde_json::json!({})).unwrap();
+    let item = s.project.render_queue[0].clone();
+    let reqs = [
+        WorkerJob::Render { items: vec![vec![(item.clone(), "/out.gif".into())]] },
+        WorkerJob::Warp { comp, layer: LayerId(3), effect: 9 },
+        WorkerJob::WarpPlan { comp, layer: LayerId(3), effect: 9, time: Tick::from_seconds_f64(0.5) },
+        WorkerJob::RotoFreeze { comp, layer: LayerId(3), effect: 9 },
+        WorkerJob::Camera { comp, layer: LayerId(3), effect: 9 },
+        WorkerJob::RotoPropagate { comp, layer: LayerId(3), effect: 9, direction: crate::roto::Direction::Forward },
+        WorkerJob::Track {
+            comp,
+            layer: LayerId(1),
+            tracker: 4,
+            direction: crate::tracking::Direction::Backward,
+            settings: TrackerSettings::default(),
+            points: vec![PointValues {
+                uid: 5,
+                spec: effectcraft_track::PointSpec { center: [1.0, 2.0], feature_size: [3.0, 4.0], search_offset: [0.5, 0.0], search_size: [9.0, 9.0] },
+                attach_offset: [0.25, -1.0],
+            }],
+            times: vec![Tick::ZERO, Tick::from_seconds_f64(0.5)],
+        },
+        WorkerJob::MaskTrack {
+            comp,
+            layer: LayerId(2),
+            mask: 7,
+            direction: crate::tracking::Direction::Forward,
+            path: ShapePath::ellipse([10.0, 20.0], 5.0, 6.0),
+            method: MaskMethod::Perspective,
+            times: vec![Tick::from_seconds_f64(1.0)],
+        },
+        WorkerJob::ContentFill {
+            plan: Box::new(crate::commands::content_fill::FillPlan {
+                comp,
+                layer: LayerId(2),
+                name: "Clip".into(),
+                width: 4,
+                height: 3,
+                times: vec![Tick::ZERO],
+                method: "object".into(),
+                lighting: 0.5,
+                expand: 1,
+                reference: Some((LayerId(1), Tick::ZERO)),
+                dir: "/Fill/Clip_Fill_1".into(),
+            }),
+        },
+    ];
+    for job in reqs {
+        let kind = job.kind();
+        let req = WorkerRequest { id: 42, project: s.project.to_json(), files: footage_files(&s.project), job };
+        let t = round(&req);
+        assert!(t.contains("\"kind\":"), "{kind:?}");
+        let back: WorkerRequest = serde_json::from_str(&t).unwrap();
+        assert_eq!(back.job.kind(), kind);
+        assert_eq!(Project::from_json(&back.project).unwrap(), *s.project);
+    }
+    let g = s.active_comp().unwrap().layers[0].props.clone();
+    for r in [
+        WorkerReply::Render { state: JobState { current: Some(3), done: 4, total: 10, items_total: 1, ..Default::default() } },
+        WorkerReply::Item { update: ItemUpdate::Started { id: 3, unix: 1_700_000_000 } },
+        WorkerReply::Item { update: ItemUpdate::Finished { id: 3, status: RenderStatus::Failed("x".into()), seconds: 1.5, output: Some("/a.gif".into()) } },
+        WorkerReply::Progress { done: 1, total: 2 },
+        WorkerReply::WarpPlan {
+            key: [1, u64::MAX],
+            summary: Box::new(effectcraft_effects::warp_stab::PlanSummary {
+                warps: vec![[[1.0, 0.0, 2.5], [0.0, 1.0, -1.0], [0.0, 0.0, 1.0]]],
+                auto_scale: 1.08,
+                crop: Some([1.0, 2.0, 300.0, 200.0]),
+                valid_fraction: 0.9,
+            }),
+        },
+        WorkerReply::Group { comp, layer: LayerId(1), group: Box::new(g), message: "ok".into() },
+        WorkerReply::Segs { segs: vec![SegData::new(5, &effectcraft_track::roto::FrameSeg::empty(4, 3))] },
+        WorkerReply::Fill {
+            plan: Box::new(crate::commands::content_fill::FillPlan {
+                comp,
+                layer: LayerId(2),
+                name: "Clip".into(),
+                width: 4,
+                height: 3,
+                times: vec![Tick::ZERO],
+                method: "object".into(),
+                lighting: 0.5,
+                expand: 1,
+                reference: Some((LayerId(1), Tick::ZERO)),
+                dir: "/Fill/Clip_Fill_1".into(),
+            }),
+            files: vec!["/Fill/Clip_Fill_1/fill_00000.png".into()],
+        },
+        WorkerReply::Failed { error: "boom".into() },
+        WorkerReply::Done,
+    ] {
+        let t = round(&r);
+        assert!(t.starts_with("{\"type\":"), "{t}");
+    }
+}
+
+/// An [`Offload`] that runs the job right away in a second session, through JSON (what a
+/// Web Worker does, minus the threads).
+struct Inline;
+impl Offload for Inline {
+    fn start(&self, req: WorkerRequest, inbox: Arc<Inbox>) -> Result<(), String> {
+        let req: WorkerRequest = serde_json::from_str(&serde_json::to_string(&req).unwrap()).unwrap();
+        let mut w = Session { exporter: Some(Arc::new(crate::rq_tests::MockExporter { log: Default::default() })), ..Default::default() };
+        let post: Post = Rc::new(move |r| inbox.push(serde_json::from_str(&serde_json::to_string(&r).unwrap()).unwrap()));
+        run_request(&mut w, req, &post);
+        Ok(())
+    }
+    fn cancel(&self, _: u64) {}
+}
+
+#[test]
+fn render_runs_through_the_offload() {
+    let mut s =
+        Session { exporter: Some(Arc::new(crate::rq_tests::MockExporter { log: Default::default() })), offload: Some(Arc::new(Inline)), ..Default::default() };
+    s.execute("file.openDemoProject", serde_json::json!({})).unwrap();
+    s.execute("renderQueue.add", serde_json::json!({"output": "/x.gif"})).unwrap();
+    let ids = s.start_render(false).unwrap();
+    // (the inline offload has replied already; replies are applied when polled)
+    s.poll_render();
+    assert!(s.render_job.is_none());
+    let it = s.project.render_queue.iter().find(|i| i.id == ids[0]).unwrap();
+    assert_eq!(it.status, RenderStatus::Done, "{:?}", it.status);
+    assert!(it.last_output.as_deref().is_some_and(|o| o.ends_with("x.gif")));
+    // `wait` renders inline.
+    s.execute("renderQueue.add", serde_json::json!({"output": "/y.gif"})).unwrap();
+    s.start_render(true).unwrap();
+    assert!(s.render_job.is_none() || s.render_job.as_ref().unwrap().remote.is_none());
+}
+
+/// Runs jobs in a session sharing `footage` (the synthetic clip of the tracking tests).
+struct InlineWith(Arc<dyn effectcraft_render::FootageSource>);
+impl Offload for InlineWith {
+    fn start(&self, req: WorkerRequest, inbox: Arc<Inbox>) -> Result<(), String> {
+        let req: WorkerRequest = serde_json::from_str(&serde_json::to_string(&req).unwrap()).unwrap();
+        let mut w = Session { footage: self.0.clone(), ..Default::default() };
+        let post: Post = Rc::new(move |r| inbox.push(serde_json::from_str(&serde_json::to_string(&r).unwrap()).unwrap()));
+        run_request(&mut w, req, &post);
+        Ok(())
+    }
+    fn cancel(&self, _: u64) {}
+}
+
+/// Never replies (a job still running); records cancellations.
+#[derive(Default)]
+struct Hanging(Mutex<Vec<u64>>);
+impl Offload for Hanging {
+    fn start(&self, _: WorkerRequest, _: Arc<Inbox>) -> Result<(), String> {
+        Ok(())
+    }
+    fn cancel(&self, id: u64) {
+        self.0.lock().unwrap().push(id);
+    }
+}
+
+fn pose(f: u32) -> ([f64; 2], f64, f64) {
+    ([150.0 + 2.0 * f as f64, 110.0 + 1.0 * f as f64], 0.0, 1.0)
+}
+
+#[test]
+fn track_analysis_runs_through_the_offload_as_one_undo_step() {
+    let (mut s, clip, _) = crate::tests::track::setup(crate::tests::track::patch_frames(pose));
+    s.offload = Some(Arc::new(InlineWith(s.footage.clone())));
+    s.execute("track.motion", serde_json::json!({})).unwrap();
+    s.execute("track.setPoint", serde_json::json!({"point": 1, "center": pose(0).0, "featureSize": [36, 36], "searchSize": [80, 80]})).unwrap();
+    let undo = s.history.undo.len();
+    s.execute("track.analyze", serde_json::json!({"direction": "forward"})).unwrap();
+    assert!(s.is_tracking() && s.track_job.is_none(), "offloaded, not on a thread");
+    assert!(s.track_progress().is_some());
+    assert!(s.poll_offload());
+    assert!(!s.is_tracking() && s.offloaded.is_empty());
+    let l = s.active_comp().unwrap().layer(clip).unwrap();
+    let tp = l.trackers().next().unwrap().0.track_points().next().unwrap().clone();
+    let fc = tp.get("featureCenter").unwrap();
+    assert_eq!(fc.keys.len(), 25);
+    let v = fc.value_at(crate::tests::track::frame_time(12)).as_vec2();
+    assert!((v[0] - pose(12).0[0]).abs() < 0.3 && (v[1] - pose(12).0[1]).abs() < 0.3, "{v:?}");
+    assert_eq!(s.history.undo.len(), undo + 1);
+    assert_eq!(s.history.undo.last().unwrap().0, "Analyze Track");
+    assert!(s.events.iter().any(|e| matches!(e, Event::Toast { message, error: false } if message.starts_with("Tracked"))));
+    assert!(s.undo());
+    let l = s.active_comp().unwrap().layer(clip).unwrap();
+    assert!(l.trackers().next().unwrap().0.track_points().next().unwrap().get("featureCenter").unwrap().keys.is_empty());
+    // `wait` runs inline.
+    s.redo();
+    s.execute("track.analyze", serde_json::json!({"direction": "forward", "wait": true})).ok();
+    assert!(s.offloaded.is_empty());
+}
+
+#[test]
+fn cancelling_offloaded_jobs() {
+    let (mut s, _, _) = crate::tests::track::setup(crate::tests::track::patch_frames(pose));
+    let off = Arc::new(Hanging::default());
+    s.offload = Some(off.clone());
+    s.exporter = Some(Arc::new(crate::rq_tests::MockExporter { log: Default::default() }));
+    // Analysis: stopping drops the job, nothing is written.
+    s.execute("track.motion", serde_json::json!({})).unwrap();
+    let rev = s.revision;
+    s.execute("track.analyze", serde_json::json!({})).unwrap();
+    assert!(s.is_tracking());
+    assert!(s.execute("track.analyze", serde_json::json!({})).is_err(), "one at a time");
+    assert!(s.stop_track());
+    s.poll_offload();
+    assert!(!s.is_tracking());
+    assert_eq!(off.0.lock().unwrap().len(), 1);
+    assert!(s.events.iter().any(|e| matches!(e, Event::Toast { message, .. } if message.contains("stopped"))));
+    assert!(s.revision > rev);
+    // Render: the queued items become User Stopped.
+    s.execute("renderQueue.add", serde_json::json!({"output": "/a.gif"})).unwrap();
+    let ids = s.start_render(false).unwrap();
+    assert!(s.is_rendering());
+    assert!(s.stop_render());
+    s.poll_render();
+    assert!(!s.is_rendering());
+    assert_eq!(off.0.lock().unwrap().len(), 2);
+    let it = s.project.render_queue.iter().find(|i| i.id == ids[0]).unwrap();
+    assert_eq!(it.status, RenderStatus::UserStopped);
+}
+
+#[test]
+fn progress_hook_is_scoped() {
+    report(1, 2); // no hook: nothing happens
+    let seen = Rc::new(RefCell::new(vec![]));
+    let s2 = seen.clone();
+    effectcraft_render::passes::block_on(with_hook(Box::new(move |d, t| s2.borrow_mut().push((d, t))), async {
+        report(1, 3);
+        report(2, 3);
+    }));
+    report(3, 3);
+    assert_eq!(*seen.borrow(), vec![(1, 3), (2, 3)]);
+}
diff --git a/crates/engine/src/remote.rs b/crates/engine/src/background/remote.rs
similarity index 55%
rename from crates/engine/src/remote.rs
rename to crates/engine/src/background/remote.rs
index 66417ccee..6539ac767 100644
--- a/crates/engine/src/remote.rs
+++ b/crates/engine/src/background/remote.rs
@@ -472,331 +472,4 @@ impl FrameServer {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::Session;
-    use serde_json::json;
-
-    fn round<T: Serialize + for<'de> Deserialize<'de>>(v: &T) -> T {
-        serde_json::from_str(&serde_json::to_string(v).unwrap()).unwrap()
-    }
-
-    #[test]
-    fn diff_and_patch_round_trip() {
-        let a = json!({"a": 1, "b": [1, 2, {"c": null}], "d": {"e": "x", "f": [1]}, "g": null});
-        let b = json!({"a": 2, "b": [1, 3, {"c": 4}], "d": {"f": [1, 2]}, "g": null, "h": {"i": null}});
-        let ops = diff(&a, &b);
-        assert!(!ops.is_empty());
-        let mut x = a.clone();
-        patch(&mut x, &round(&ops)).unwrap();
-        assert_eq!(x, b);
-        // Removal and the reverse direction.
-        let mut y = b.clone();
-        patch(&mut y, &diff(&b, &a)).unwrap();
-        assert_eq!(y, a);
-        assert!(diff(&a, &a).is_empty());
-        // A whole-document change.
-        let mut z = json!(1);
-        patch(&mut z, &diff(&json!(1), &json!([1]))).unwrap();
-        assert_eq!(z, json!([1]));
-        // A patch for another document fails cleanly.
-        assert!(patch(&mut json!(3), &diff(&a, &b)).is_err());
-    }
-
-    fn server(s: &Session) -> FrameServer {
-        FrameServer::new(s.footage.clone(), s.expr.clone())
-    }
-
-    /// Pixels the page itself would render.
-    fn local(s: &Session, comp: ItemId, t: Tick, opts: RenderOpts) -> Vec<u8> {
-        let mut r = Renderer::new(&s.project, s.footage.as_ref(), opts);
-        r.expr = s.expr.as_deref();
-        rgba8_premultiplied(&r.comp_frame(comp, t))
-    }
-
-    /// Layer buffers through the disk store: a worker's slow buffers queue up as entries; the
-    /// page plans what another worker fetches before its frame (recent misses on disk); that
-    /// worker's mid-render lookups find them and the pixels match.
-    #[test]
-    fn layer_buffers_go_through_the_disk_store() {
-        use effectcraft_render::disk_cache::{DiskIndex, Kind, LayerPrefetch};
-        let mut s = Session::default();
-        s.execute("file.openDemoProject", json!({})).unwrap();
-        let comp = s.active_comp_id().unwrap();
-        let opts = RenderOpts { scale: 0.25, ..Default::default() };
-        let t = Tick::from_seconds_f64(1.0);
-        let req = |id: u64, layers: bool, prefetch: Vec<String>| {
-            round(&FrameMsg::Render { id, revision: s.revision, comp, time: t, opts: Box::new(opts), disk: None, layers, prefetch })
-        };
-        let worker = || {
-            let mut w = server(&s);
-            let store = Arc::new(PrefetchStore::new(64 << 20).with_min_ms(0));
-            w.set_layer_store(Some(store.clone()));
-            let mut m = Mirror::default();
-            assert!(w.handle(round(&m.sync(s.revision, &s.project).unwrap())).is_empty());
-            (w, store)
-        };
-        let unhex = |v: &[String]| v.iter().map(|k| u128::from_str_radix(k, 16).unwrap()).collect::<Vec<u128>>();
-        // Worker A: everything misses; its buffers queue up for the disk.
-        let (mut a, store_a) = worker();
-        let out = a.handle(req(1, true, vec![]));
-        let (FrameReply::Frame { layer_misses, layer_hits, .. }, Some(px_a)) = &out[0] else { panic!("{:?}", out[0].0) };
-        assert!(!layer_misses.is_empty() && layer_hits.is_empty());
-        let writes = store_a.take_writes();
-        assert!(!writes.is_empty());
-        assert!(writes.iter().all(|(k, _)| (*k >> 64) as u64 == a.salt()), "keys are salted per project");
-        let mut index = DiskIndex::default();
-        let mut disk = std::collections::HashMap::new();
-        for (k, e) in writes {
-            index.insert(Kind::Layer, k, e.len() as u64);
-            disk.insert(k, e);
-        }
-        index.insert(Kind::Frame, 1, 10);
-        // The page: recent misses that are on disk, most recent first.
-        let mut plan = LayerPrefetch::default();
-        plan.note_misses(unhex(layer_misses));
-        let keys = plan.plan(&index, 64);
-        assert!(!keys.is_empty() && keys.len() <= index.len());
-        // Worker B fetches them before its first frame: its lookups hit.
-        let (mut b, store_b) = worker();
-        for k in &keys {
-            assert!(store_b.provide(*k, &disk[k]));
-        }
-        assert!(!store_b.provide(1, b"damaged"));
-        let out = b.handle(req(1, true, keys.iter().map(|k| format!("{k:032x}")).collect()));
-        let (FrameReply::Frame { layer_misses: mb, layer_hits: hb, .. }, Some(px_b)) = &out[0] else { panic!("{:?}", out[0].0) };
-        assert_eq!(unhex(hb).len(), keys.len(), "every fetched buffer was used");
-        assert!(mb.len() < layer_misses.len());
-        assert_eq!(px_a, px_b);
-        assert_eq!(*px_b, local(&s, comp, t, opts));
-        // Nothing new to write: what B rendered itself was rendered by A too.
-        assert!(store_b.take_writes().iter().all(|(k, _)| disk.contains_key(k)));
-        // Without `layers` the store is not consulted.
-        let (mut c, store_c) = worker();
-        c.handle(req(1, false, vec![]));
-        assert!(store_c.take_misses().is_empty() && store_c.take_writes().is_empty());
-        // Purge empties the store.
-        b.handle(round(&FrameMsg::Purge));
-        assert!(!store_b.has(keys[0]));
-        // LRU across frames and layers in the shared index: a touched layer outlives the frame.
-        index.touch(Kind::Layer, keys[0]);
-        let order = index.lru_order();
-        assert_eq!(order.last(), Some(&(Kind::Layer, keys[0])));
-        assert!(order.iter().position(|e| *e == (Kind::Frame, 1)).unwrap() < order.len() - 1);
-    }
-
-    #[test]
-    fn replica_follows_edits_through_diffs_and_renders_the_same_frames() {
-        let mut s = Session::default();
-        s.execute("file.openDemoProject", json!({})).unwrap();
-        let comp = s.active_comp_id().unwrap();
-        let opts = RenderOpts { scale: 0.25, guides: true, ..Default::default() };
-        let mut m = Mirror::default();
-        let mut w = server(&s);
-        let send = |m: FrameMsg, w: &mut FrameServer| w.handle(round(&m));
-        // First sync: the whole project.
-        let first = m.sync(s.revision, &s.project).unwrap();
-        assert!(matches!(first, FrameMsg::Project { .. }));
-        assert!(send(first, &mut w).is_empty());
-        assert!(m.sync(s.revision, &s.project).is_none(), "nothing new");
-        let t = Tick::from_seconds_f64(1.0);
-        let render = |w: &mut FrameServer, rev: u64, id: u64| {
-            w.handle(round(&FrameMsg::Render { id, revision: rev, comp, time: t, opts: Box::new(opts), disk: None, layers: false, prefetch: vec![] }))
-        };
-        let out = render(&mut w, s.revision, 1);
-        let (FrameReply::Frame { id, width, height, .. }, Some(px)) = &out[0] else { panic!("{:?}", out[0].0) };
-        assert_eq!((*id, *width as usize * *height as usize * 4), (1, px.len()));
-        assert_eq!(*px, local(&s, comp, t, opts));
-        // An edit travels as a small diff; the replica renders the edited frame.
-        s.execute("layer.newSolid", json!({"color": "#ff8800", "name": "Orange"})).unwrap();
-        let msg = m.sync(s.revision, &s.project).unwrap();
-        let FrameMsg::Patch { ops, .. } = &msg else { panic!("expected a patch") };
-        assert!(!ops.is_empty() && serde_json::to_string(ops).unwrap().len() < s.project.to_json().len() / 2);
-        assert!(send(msg, &mut w).is_empty());
-        assert_eq!(**w.project().unwrap(), *s.project);
-        let out = render(&mut w, s.revision, 2);
-        assert_eq!(out[0].1.as_deref(), Some(&local(&s, comp, t, opts)[..]));
-        // A request for another revision is refused as stale.
-        let out = render(&mut w, s.revision + 7, 3);
-        assert!(matches!(out[0].0, FrameReply::Failed { id: 3, stale: true, .. }));
-        // A patch from the wrong base asks for a resync; the mirror then sends the project.
-        let bad = FrameMsg::Patch { from: 999, revision: 1000, ops: vec![] };
-        assert!(matches!(send(bad, &mut w)[0].0, FrameReply::Resync { .. }));
-        m.reset();
-        assert!(matches!(m.sync(s.revision, &s.project), Some(FrameMsg::Project { .. })));
-    }
-
-    #[test]
-    fn frame_messages_round_trip() {
-        for m in [
-            FrameMsg::Purge,
-            FrameMsg::Segs { segs: vec![SegData { key: 7, data: "AAAA".into() }] },
-            FrameMsg::Render {
-                id: 3,
-                revision: 4,
-                comp: ItemId(2),
-                time: Tick::from_seconds_f64(0.5),
-                opts: Box::new(RenderOpts { scale: 0.5, draft: true, roi: Some([1.0, 2.0, 3.0, 4.0]), ..Default::default() }),
-                disk: Some(format!("{:032x}", 0xabcdu128)),
-                layers: true,
-                prefetch: vec![format!("{:032x}", 7u128)],
-            },
-        ] {
-            let a = serde_json::to_string(&m).unwrap();
-            assert_eq!(serde_json::to_string(&round(&m)).unwrap(), a);
-            assert!(a.starts_with("{\"type\":"), "{a}");
-        }
-        for r in [
-            FrameReply::Frame { id: 1, width: 2, height: 3, ms: 4.5, passes: 2, gpu: true, layer_misses: vec!["0a".into()], layer_hits: vec![] },
-            FrameReply::Stored { key: "00ff".into(), bytes: 9, layer: false },
-            FrameReply::Stored { key: "00fe".into(), bytes: 8, layer: true },
-            FrameReply::Info { gpu: Some("Adapter (BrowserWebGpu)".into()), error: None },
-            FrameReply::Failed { id: 1, error: "x".into(), stale: true },
-            FrameReply::Resync { error: "y".into() },
-        ] {
-            assert_eq!(round(&r), r);
-        }
-    }
-
-    /// An accelerator with deferred readbacks: a GPU effect chain is "read back" one
-    /// [`Deferred::settle`] after it was first asked for (computed with the CPU effects, so the
-    /// finished frame equals the CPU render); until then it misses and returns its input.
-    #[derive(Default)]
-    struct Deferred {
-        ready: std::sync::Mutex<std::collections::HashSet<u64>>,
-        asked: std::sync::Mutex<std::collections::HashSet<u64>>,
-        gate: Arc<std::sync::atomic::AtomicBool>,
-        chains: std::sync::atomic::AtomicUsize,
-        auto: effectcraft_render::AutoPick,
-    }
-
-    impl Deferred {
-        fn settle(&self) {
-            let asked: Vec<u64> = self.asked.lock().unwrap().drain().collect();
-            self.ready.lock().unwrap().extend(asked);
-        }
-    }
-
-    impl Accelerator for Deferred {
-        fn name(&self) -> String {
-            "deferred".into()
-        }
-        fn comp_frame(&self, _: &Renderer, _: ItemId, _: Tick) -> Option<Image> {
-            None
-        }
-        fn supports_effect(&self, id: &str) -> bool {
-            effectcraft_effects::GPU_EFFECTS.contains(&id)
-        }
-        fn effects(&self, chain: &[effectcraft_render::FxStep], buf: &effectcraft_effects::Buf, levels: Option<f32>) -> Option<effectcraft_effects::Buf> {
-            use std::hash::{Hash, Hasher};
-            let mut h = std::collections::hash_map::DefaultHasher::new();
-            for s in chain {
-                s.spec.id.hash(&mut h);
-                s.ctx.time.to_bits().hash(&mut h);
-            }
-            (buf.img.width, buf.img.height).hash(&mut h);
-            for p in &buf.img.data {
-                for c in p {
-                    c.to_bits().hash(&mut h);
-                }
-            }
-            let key = h.finish();
-            if !self.ready.lock().unwrap().contains(&key) {
-                self.asked.lock().unwrap().insert(key);
-                self.gate.store(true, std::sync::atomic::Ordering::Relaxed);
-                return Some(buf.clone());
-            }
-            self.chains.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
-            let mut b = buf.clone();
-            for s in chain {
-                b = effectcraft_effects::apply(s.spec, &s.ctx, b);
-                if let Some(l) = levels {
-                    effectcraft_render::color::quantize(&mut b.img, l);
-                }
-            }
-            Some(b)
-        }
-        fn auto_pick(&self) -> Option<&effectcraft_render::AutoPick> {
-            Some(&self.auto)
-        }
-        fn frame_begin(&self) {
-            self.ready.lock().unwrap().clear();
-        }
-        fn pass_begin(&self) {
-            self.gate.store(false, std::sync::atomic::Ordering::Relaxed);
-        }
-        fn pass_missed(&self) -> bool {
-            self.gate.load(std::sync::atomic::Ordering::Relaxed)
-        }
-        fn miss_gate(&self) -> Option<Arc<std::sync::atomic::AtomicBool>> {
-            Some(self.gate.clone())
-        }
-    }
-
-    #[test]
-    fn deferred_readbacks_render_in_passes() {
-        let mut s = Session::default();
-        s.execute("file.openDemoProject", json!({})).unwrap();
-        let comp = s.active_comp_id().unwrap();
-        s.execute("layer.newSolid", json!({"color": "#3388ff", "name": "Blue", "width": 200, "height": 120})).unwrap();
-        s.execute("effect.apply", json!({"effect": "ec.blur.gaussian"})).unwrap();
-        s.execute("effect.apply", json!({"effect": "ec.stylize.glow"})).unwrap();
-        s.execute("layer.newSolid", json!({"color": "#ffcc00", "name": "Yellow", "width": 80, "height": 80})).unwrap();
-        s.execute("effect.apply", json!({"effect": "ec.color.levels"})).unwrap();
-        let opts = RenderOpts { scale: 0.25, backend: Backend::Gpu, ..Default::default() };
-        let t = Tick::from_seconds_f64(1.0);
-        let mut w = server(&s);
-        let acc = Arc::new(Deferred::default());
-        w.set_accel(Some(acc.clone()));
-        let mut m = Mirror::default();
-        w.handle(round(&m.sync(s.revision, &s.project).unwrap()));
-        let req = |id| round(&FrameMsg::Render { id, revision: s.revision, comp, time: t, opts: Box::new(opts), disk: None, layers: false, prefetch: vec![] });
-        assert!(w.handle(req(1)).is_empty() && w.waiting(), "the first pass misses");
-        let mut out = vec![];
-        for _ in 0..10 {
-            acc.settle();
-            out = w.resume();
-            if !w.waiting() {
-                break;
-            }
-        }
-        let (FrameReply::Frame { id: 1, passes, gpu: true, .. }, Some(px)) = &out[0] else { panic!("{:?}", out.first().map(|o| &o.0)) };
-        assert!(*passes >= 2, "{passes}");
-        assert!(acc.chains.load(std::sync::atomic::Ordering::Relaxed) >= 2);
-        // The same pixels as the CPU: no placeholder survived, in the frame or the layer cache.
-        assert_eq!(*px, local(&s, comp, t, RenderOpts { backend: Backend::Cpu, ..opts }));
-        let out = w.handle(req(2));
-        let out = if out.is_empty() {
-            acc.settle();
-            w.resume()
-        } else {
-            out
-        };
-        assert_eq!(out[0].1.as_deref(), Some(&px[..]));
-        // CPU requests never touch the accelerator; Auto times whole frames.
-        let cpu = RenderOpts { backend: Backend::Cpu, ..opts };
-        let out =
-            w.handle(round(&FrameMsg::Render { id: 3, revision: s.revision, comp, time: t, opts: Box::new(cpu), disk: None, layers: false, prefetch: vec![] }));
-        assert!(matches!(out[0].0, FrameReply::Frame { id: 3, passes: 1, gpu: false, .. }));
-        for id in 4..12 {
-            let auto = RenderOpts { backend: Backend::Auto, ..opts };
-            let mut out = w.handle(round(&FrameMsg::Render {
-                id,
-                revision: s.revision,
-                comp,
-                time: t,
-                opts: Box::new(auto),
-                disk: None,
-                layers: false,
-                prefetch: vec![],
-            }));
-            while w.waiting() {
-                acc.settle();
-                out = w.resume();
-            }
-            assert_eq!(out[0].1.as_deref(), Some(&px[..]), "frame {id}");
-        }
-        let st = acc.auto.stats(effectcraft_render::AutoKey::new(comp, opts.scale, false)).unwrap();
-        assert!(st.cpu_frames > 0 && st.gpu_frames > 0, "{st:?}");
-    }
-}
+mod tests;
diff --git a/crates/engine/src/background/remote/tests.rs b/crates/engine/src/background/remote/tests.rs
new file mode 100644
index 000000000..85f7a1807
--- /dev/null
+++ b/crates/engine/src/background/remote/tests.rs
@@ -0,0 +1,318 @@
+use super::*;
+use crate::Session;
+use serde_json::json;
+
+fn round<T: Serialize + for<'de> Deserialize<'de>>(v: &T) -> T {
+    serde_json::from_str(&serde_json::to_string(v).unwrap()).unwrap()
+}
+
+#[test]
+fn diff_and_patch_round_trip() {
+    let a = json!({"a": 1, "b": [1, 2, {"c": null}], "d": {"e": "x", "f": [1]}, "g": null});
+    let b = json!({"a": 2, "b": [1, 3, {"c": 4}], "d": {"f": [1, 2]}, "g": null, "h": {"i": null}});
+    let ops = diff(&a, &b);
+    assert!(!ops.is_empty());
+    let mut x = a.clone();
+    patch(&mut x, &round(&ops)).unwrap();
+    assert_eq!(x, b);
+    // Removal and the reverse direction.
+    let mut y = b.clone();
+    patch(&mut y, &diff(&b, &a)).unwrap();
+    assert_eq!(y, a);
+    assert!(diff(&a, &a).is_empty());
+    // A whole-document change.
+    let mut z = json!(1);
+    patch(&mut z, &diff(&json!(1), &json!([1]))).unwrap();
+    assert_eq!(z, json!([1]));
+    // A patch for another document fails cleanly.
+    assert!(patch(&mut json!(3), &diff(&a, &b)).is_err());
+}
+
+fn server(s: &Session) -> FrameServer {
+    FrameServer::new(s.footage.clone(), s.expr.clone())
+}
+
+/// Pixels the page itself would render.
+fn local(s: &Session, comp: ItemId, t: Tick, opts: RenderOpts) -> Vec<u8> {
+    let mut r = Renderer::new(&s.project, s.footage.as_ref(), opts);
+    r.expr = s.expr.as_deref();
+    rgba8_premultiplied(&r.comp_frame(comp, t))
+}
+
+/// Layer buffers through the disk store: a worker's slow buffers queue up as entries; the
+/// page plans what another worker fetches before its frame (recent misses on disk); that
+/// worker's mid-render lookups find them and the pixels match.
+#[test]
+fn layer_buffers_go_through_the_disk_store() {
+    use effectcraft_render::disk_cache::{DiskIndex, Kind, LayerPrefetch};
+    let mut s = Session::default();
+    s.execute("file.openDemoProject", json!({})).unwrap();
+    let comp = s.active_comp_id().unwrap();
+    let opts = RenderOpts { scale: 0.25, ..Default::default() };
+    let t = Tick::from_seconds_f64(1.0);
+    let req = |id: u64, layers: bool, prefetch: Vec<String>| {
+        round(&FrameMsg::Render { id, revision: s.revision, comp, time: t, opts: Box::new(opts), disk: None, layers, prefetch })
+    };
+    let worker = || {
+        let mut w = server(&s);
+        let store = Arc::new(PrefetchStore::new(64 << 20).with_min_ms(0));
+        w.set_layer_store(Some(store.clone()));
+        let mut m = Mirror::default();
+        assert!(w.handle(round(&m.sync(s.revision, &s.project).unwrap())).is_empty());
+        (w, store)
+    };
+    let unhex = |v: &[String]| v.iter().map(|k| u128::from_str_radix(k, 16).unwrap()).collect::<Vec<u128>>();
+    // Worker A: everything misses; its buffers queue up for the disk.
+    let (mut a, store_a) = worker();
+    let out = a.handle(req(1, true, vec![]));
+    let (FrameReply::Frame { layer_misses, layer_hits, .. }, Some(px_a)) = &out[0] else { panic!("{:?}", out[0].0) };
+    assert!(!layer_misses.is_empty() && layer_hits.is_empty());
+    let writes = store_a.take_writes();
+    assert!(!writes.is_empty());
+    assert!(writes.iter().all(|(k, _)| (*k >> 64) as u64 == a.salt()), "keys are salted per project");
+    let mut index = DiskIndex::default();
+    let mut disk = std::collections::HashMap::new();
+    for (k, e) in writes {
+        index.insert(Kind::Layer, k, e.len() as u64);
+        disk.insert(k, e);
+    }
+    index.insert(Kind::Frame, 1, 10);
+    // The page: recent misses that are on disk, most recent first.
+    let mut plan = LayerPrefetch::default();
+    plan.note_misses(unhex(layer_misses));
+    let keys = plan.plan(&index, 64);
+    assert!(!keys.is_empty() && keys.len() <= index.len());
+    // Worker B fetches them before its first frame: its lookups hit.
+    let (mut b, store_b) = worker();
+    for k in &keys {
+        assert!(store_b.provide(*k, &disk[k]));
+    }
+    assert!(!store_b.provide(1, b"damaged"));
+    let out = b.handle(req(1, true, keys.iter().map(|k| format!("{k:032x}")).collect()));
+    let (FrameReply::Frame { layer_misses: mb, layer_hits: hb, .. }, Some(px_b)) = &out[0] else { panic!("{:?}", out[0].0) };
+    assert_eq!(unhex(hb).len(), keys.len(), "every fetched buffer was used");
+    assert!(mb.len() < layer_misses.len());
+    assert_eq!(px_a, px_b);
+    assert_eq!(*px_b, local(&s, comp, t, opts));
+    // Nothing new to write: what B rendered itself was rendered by A too.
+    assert!(store_b.take_writes().iter().all(|(k, _)| disk.contains_key(k)));
+    // Without `layers` the store is not consulted.
+    let (mut c, store_c) = worker();
+    c.handle(req(1, false, vec![]));
+    assert!(store_c.take_misses().is_empty() && store_c.take_writes().is_empty());
+    // Purge empties the store.
+    b.handle(round(&FrameMsg::Purge));
+    assert!(!store_b.has(keys[0]));
+    // LRU across frames and layers in the shared index: a touched layer outlives the frame.
+    index.touch(Kind::Layer, keys[0]);
+    let order = index.lru_order();
+    assert_eq!(order.last(), Some(&(Kind::Layer, keys[0])));
+    assert!(order.iter().position(|e| *e == (Kind::Frame, 1)).unwrap() < order.len() - 1);
+}
+
+#[test]
+fn replica_follows_edits_through_diffs_and_renders_the_same_frames() {
+    let mut s = Session::default();
+    s.execute("file.openDemoProject", json!({})).unwrap();
+    let comp = s.active_comp_id().unwrap();
+    let opts = RenderOpts { scale: 0.25, guides: true, ..Default::default() };
+    let mut m = Mirror::default();
+    let mut w = server(&s);
+    let send = |m: FrameMsg, w: &mut FrameServer| w.handle(round(&m));
+    // First sync: the whole project.
+    let first = m.sync(s.revision, &s.project).unwrap();
+    assert!(matches!(first, FrameMsg::Project { .. }));
+    assert!(send(first, &mut w).is_empty());
+    assert!(m.sync(s.revision, &s.project).is_none(), "nothing new");
+    let t = Tick::from_seconds_f64(1.0);
+    let render = |w: &mut FrameServer, rev: u64, id: u64| {
+        w.handle(round(&FrameMsg::Render { id, revision: rev, comp, time: t, opts: Box::new(opts), disk: None, layers: false, prefetch: vec![] }))
+    };
+    let out = render(&mut w, s.revision, 1);
+    let (FrameReply::Frame { id, width, height, .. }, Some(px)) = &out[0] else { panic!("{:?}", out[0].0) };
+    assert_eq!((*id, *width as usize * *height as usize * 4), (1, px.len()));
+    assert_eq!(*px, local(&s, comp, t, opts));
+    // An edit travels as a small diff; the replica renders the edited frame.
+    s.execute("layer.newSolid", json!({"color": "#ff8800", "name": "Orange"})).unwrap();
+    let msg = m.sync(s.revision, &s.project).unwrap();
+    let FrameMsg::Patch { ops, .. } = &msg else { panic!("expected a patch") };
+    assert!(!ops.is_empty() && serde_json::to_string(ops).unwrap().len() < s.project.to_json().len() / 2);
+    assert!(send(msg, &mut w).is_empty());
+    assert_eq!(**w.project().unwrap(), *s.project);
+    let out = render(&mut w, s.revision, 2);
+    assert_eq!(out[0].1.as_deref(), Some(&local(&s, comp, t, opts)[..]));
+    // A request for another revision is refused as stale.
+    let out = render(&mut w, s.revision + 7, 3);
+    assert!(matches!(out[0].0, FrameReply::Failed { id: 3, stale: true, .. }));
+    // A patch from the wrong base asks for a resync; the mirror then sends the project.
+    let bad = FrameMsg::Patch { from: 999, revision: 1000, ops: vec![] };
+    assert!(matches!(send(bad, &mut w)[0].0, FrameReply::Resync { .. }));
+    m.reset();
+    assert!(matches!(m.sync(s.revision, &s.project), Some(FrameMsg::Project { .. })));
+}
+
+#[test]
+fn frame_messages_round_trip() {
+    for m in [
+        FrameMsg::Purge,
+        FrameMsg::Segs { segs: vec![SegData { key: 7, data: "AAAA".into() }] },
+        FrameMsg::Render {
+            id: 3,
+            revision: 4,
+            comp: ItemId(2),
+            time: Tick::from_seconds_f64(0.5),
+            opts: Box::new(RenderOpts { scale: 0.5, draft: true, roi: Some([1.0, 2.0, 3.0, 4.0]), ..Default::default() }),
+            disk: Some(format!("{:032x}", 0xabcdu128)),
+            layers: true,
+            prefetch: vec![format!("{:032x}", 7u128)],
+        },
+    ] {
+        let a = serde_json::to_string(&m).unwrap();
+        assert_eq!(serde_json::to_string(&round(&m)).unwrap(), a);
+        assert!(a.starts_with("{\"type\":"), "{a}");
+    }
+    for r in [
+        FrameReply::Frame { id: 1, width: 2, height: 3, ms: 4.5, passes: 2, gpu: true, layer_misses: vec!["0a".into()], layer_hits: vec![] },
+        FrameReply::Stored { key: "00ff".into(), bytes: 9, layer: false },
+        FrameReply::Stored { key: "00fe".into(), bytes: 8, layer: true },
+        FrameReply::Info { gpu: Some("Adapter (BrowserWebGpu)".into()), error: None },
+        FrameReply::Failed { id: 1, error: "x".into(), stale: true },
+        FrameReply::Resync { error: "y".into() },
+    ] {
+        assert_eq!(round(&r), r);
+    }
+}
+
+/// An accelerator with deferred readbacks: a GPU effect chain is "read back" one
+/// [`Deferred::settle`] after it was first asked for (computed with the CPU effects, so the
+/// finished frame equals the CPU render); until then it misses and returns its input.
+#[derive(Default)]
+struct Deferred {
+    ready: std::sync::Mutex<std::collections::HashSet<u64>>,
+    asked: std::sync::Mutex<std::collections::HashSet<u64>>,
+    gate: Arc<std::sync::atomic::AtomicBool>,
+    chains: std::sync::atomic::AtomicUsize,
+    auto: effectcraft_render::AutoPick,
+}
+
+impl Deferred {
+    fn settle(&self) {
+        let asked: Vec<u64> = self.asked.lock().unwrap().drain().collect();
+        self.ready.lock().unwrap().extend(asked);
+    }
+}
+
+impl Accelerator for Deferred {
+    fn name(&self) -> String {
+        "deferred".into()
+    }
+    fn comp_frame(&self, _: &Renderer, _: ItemId, _: Tick) -> Option<Image> {
+        None
+    }
+    fn supports_effect(&self, id: &str) -> bool {
+        effectcraft_effects::GPU_EFFECTS.contains(&id)
+    }
+    fn effects(&self, chain: &[effectcraft_render::FxStep], buf: &effectcraft_effects::Buf, levels: Option<f32>) -> Option<effectcraft_effects::Buf> {
+        use std::hash::{Hash, Hasher};
+        let mut h = std::collections::hash_map::DefaultHasher::new();
+        for s in chain {
+            s.spec.id.hash(&mut h);
+            s.ctx.time.to_bits().hash(&mut h);
+        }
+        (buf.img.width, buf.img.height).hash(&mut h);
+        for p in &buf.img.data {
+            for c in p {
+                c.to_bits().hash(&mut h);
+            }
+        }
+        let key = h.finish();
+        if !self.ready.lock().unwrap().contains(&key) {
+            self.asked.lock().unwrap().insert(key);
+            self.gate.store(true, std::sync::atomic::Ordering::Relaxed);
+            return Some(buf.clone());
+        }
+        self.chains.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+        let mut b = buf.clone();
+        for s in chain {
+            b = effectcraft_effects::apply(s.spec, &s.ctx, b);
+            if let Some(l) = levels {
+                effectcraft_render::color::quantize(&mut b.img, l);
+            }
+        }
+        Some(b)
+    }
+    fn auto_pick(&self) -> Option<&effectcraft_render::AutoPick> {
+        Some(&self.auto)
+    }
+    fn frame_begin(&self) {
+        self.ready.lock().unwrap().clear();
+    }
+    fn pass_begin(&self) {
+        self.gate.store(false, std::sync::atomic::Ordering::Relaxed);
+    }
+    fn pass_missed(&self) -> bool {
+        self.gate.load(std::sync::atomic::Ordering::Relaxed)
+    }
+    fn miss_gate(&self) -> Option<Arc<std::sync::atomic::AtomicBool>> {
+        Some(self.gate.clone())
+    }
+}
+
+#[test]
+fn deferred_readbacks_render_in_passes() {
+    let mut s = Session::default();
+    s.execute("file.openDemoProject", json!({})).unwrap();
+    let comp = s.active_comp_id().unwrap();
+    s.execute("layer.newSolid", json!({"color": "#3388ff", "name": "Blue", "width": 200, "height": 120})).unwrap();
+    s.execute("effect.apply", json!({"effect": "ec.blur.gaussian"})).unwrap();
+    s.execute("effect.apply", json!({"effect": "ec.stylize.glow"})).unwrap();
+    s.execute("layer.newSolid", json!({"color": "#ffcc00", "name": "Yellow", "width": 80, "height": 80})).unwrap();
+    s.execute("effect.apply", json!({"effect": "ec.color.levels"})).unwrap();
+    let opts = RenderOpts { scale: 0.25, backend: Backend::Gpu, ..Default::default() };
+    let t = Tick::from_seconds_f64(1.0);
+    let mut w = server(&s);
+    let acc = Arc::new(Deferred::default());
+    w.set_accel(Some(acc.clone()));
+    let mut m = Mirror::default();
+    w.handle(round(&m.sync(s.revision, &s.project).unwrap()));
+    let req = |id| round(&FrameMsg::Render { id, revision: s.revision, comp, time: t, opts: Box::new(opts), disk: None, layers: false, prefetch: vec![] });
+    assert!(w.handle(req(1)).is_empty() && w.waiting(), "the first pass misses");
+    let mut out = vec![];
+    for _ in 0..10 {
+        acc.settle();
+        out = w.resume();
+        if !w.waiting() {
+            break;
+        }
+    }
+    let (FrameReply::Frame { id: 1, passes, gpu: true, .. }, Some(px)) = &out[0] else { panic!("{:?}", out.first().map(|o| &o.0)) };
+    assert!(*passes >= 2, "{passes}");
+    assert!(acc.chains.load(std::sync::atomic::Ordering::Relaxed) >= 2);
+    // The same pixels as the CPU: no placeholder survived, in the frame or the layer cache.
+    assert_eq!(*px, local(&s, comp, t, RenderOpts { backend: Backend::Cpu, ..opts }));
+    let out = w.handle(req(2));
+    let out = if out.is_empty() {
+        acc.settle();
+        w.resume()
+    } else {
+        out
+    };
+    assert_eq!(out[0].1.as_deref(), Some(&px[..]));
+    // CPU requests never touch the accelerator; Auto times whole frames.
+    let cpu = RenderOpts { backend: Backend::Cpu, ..opts };
+    let out =
+        w.handle(round(&FrameMsg::Render { id: 3, revision: s.revision, comp, time: t, opts: Box::new(cpu), disk: None, layers: false, prefetch: vec![] }));
+    assert!(matches!(out[0].0, FrameReply::Frame { id: 3, passes: 1, gpu: false, .. }));
+    for id in 4..12 {
+        let auto = RenderOpts { backend: Backend::Auto, ..opts };
+        let mut out =
+            w.handle(round(&FrameMsg::Render { id, revision: s.revision, comp, time: t, opts: Box::new(auto), disk: None, layers: false, prefetch: vec![] }));
+        while w.waiting() {
+            acc.settle();
+            out = w.resume();
+        }
+        assert_eq!(out[0].1.as_deref(), Some(&px[..]), "frame {id}");
+    }
+    let st = acc.auto.stats(effectcraft_render::AutoKey::new(comp, opts.scale, false)).unwrap();
+    assert!(st.cpu_frames > 0 && st.gpu_frames > 0, "{st:?}");
+}
diff --git a/crates/engine/src/cmd.rs b/crates/engine/src/cmd.rs
new file mode 100644
index 000000000..cba6df6ef
--- /dev/null
+++ b/crates/engine/src/cmd.rs
@@ -0,0 +1,296 @@
+//! The command registry. Ids follow After Effects' menu structure; every menu item, panel button,
+//! shortcut and viewer/timeline gesture maps to one of these.
+
+mod align;
+mod align_data;
+mod anim;
+mod anim_presets;
+pub mod anim_tools;
+mod animation;
+pub(crate) mod app_more;
+mod autotrace;
+mod batch;
+mod camera_cmds;
+mod comp;
+pub(crate) mod comp_more;
+pub mod content_fill;
+mod create;
+mod edit;
+mod effect;
+pub use effect::CryptoProbeJob;
+pub(crate) use effect::{CryptoProbeSlot, crypto_probe_job, crypto_probe_ready, keep_crypto_probe, kept_crypto_probe};
+pub mod essential;
+pub mod expr_tools;
+mod file;
+pub(crate) mod file_more;
+mod focus;
+pub mod footage_panel;
+pub(crate) mod frame_export;
+mod frontend;
+mod help;
+mod import_project;
+mod key_labels;
+mod key_transform;
+mod keys_more;
+mod layer;
+mod layer_menu;
+mod layer_time;
+pub(crate) mod link;
+mod liquify;
+mod lottie;
+pub mod markers;
+mod mask;
+pub mod mask_interp;
+pub(crate) mod model3d;
+mod nav_more;
+pub mod paint;
+pub mod panels_cmds;
+pub(crate) mod path_nulls;
+mod paths;
+mod project_items;
+pub(crate) mod prop;
+mod prop_groups;
+mod proxy;
+pub mod puppet;
+mod query;
+mod quick_offset;
+mod relink;
+pub(crate) mod relink_moved;
+mod render_queue;
+pub(crate) mod rig3d;
+pub mod roto_cmds;
+mod scene_detect;
+pub mod scripts;
+mod settings;
+pub mod shape_stroke;
+pub mod shape_tool;
+mod stubs;
+mod styles;
+mod text_anim;
+pub mod text_edit;
+mod three_d;
+pub mod time;
+mod timeline;
+mod track;
+mod view;
+pub mod viewer_cmds;
+pub(crate) mod vpe;
+pub(crate) mod vr_editor;
+mod warp_cmds;
+pub(crate) mod watch_folder;
+#[cfg(test)]
+pub(crate) use app_more::report_text as report_text_for_tests;
+pub(crate) use app_more::view_command;
+#[cfg(test)]
+pub(crate) use file::open as open_for_tests;
+#[cfg(test)]
+pub(crate) use keys_more::amplitudes as amplitudes_for_tests;
+#[cfg(test)]
+pub(crate) use mask::split_segment as split_segment_for_tests;
+
+use std::sync::OnceLock;
+
+use effectcraft_project::{Comp, ItemId, Layer, LayerId};
+use effectcraft_time::Tick;
+use serde_json::Value;
+
+use crate::{EngineError, Result, Session};
+
+pub type Run = fn(&mut Session, &Value) -> Result<Value>;
+pub type Enabled = fn(&Session) -> std::result::Result<(), String>;
+
+/// Metadata + implementation for one command.
+pub struct CommandSpec {
+    pub id: &'static str,
+    pub label: &'static str,
+    /// Menu placement, e.g. `["Layer", "New"]`. Empty = not in menus.
+    pub menu: &'static [&'static str],
+    /// Default shortcut (egui-style names, `Cmd` = ⌘ on macOS / Ctrl elsewhere).
+    pub shortcut: Option<&'static str>,
+    /// Further default shortcuts (the menus and tooltips show `shortcut`).
+    pub alt_shortcuts: &'static [&'static str],
+    /// Parameter description for agents and the MCP schema.
+    pub params: &'static str,
+    pub enabled: Enabled,
+    pub run: Run,
+    /// Record in the journal (false for pure queries).
+    pub journal: bool,
+}
+
+#[macro_export]
+macro_rules! cmd {
+    // Several default shortcuts: `["PageDown", "Cmd+ArrowRight"]`.
+    ($id:literal, $label:literal, [$($m:literal),*], [$sc:literal, $($alt:literal),+], $params:literal, $en:expr, $run:expr) => {
+        $crate::commands::CommandSpec { alt_shortcuts: &[$($alt),+], ..$crate::cmd!($id, $label, [$($m),*], Some($sc), $params, $en, $run) }
+    };
+    ($id:literal, $label:literal, [$($m:literal),*], $sc:expr, $params:literal, $en:expr, $run:expr) => {
+        $crate::commands::CommandSpec {
+            id: $id,
+            label: $label,
+            menu: &[$($m),*],
+            shortcut: $sc,
+            alt_shortcuts: &[],
+            params: $params,
+            enabled: $en,
+            run: $run,
+            journal: true,
+        }
+    };
+}
+#[macro_export]
+macro_rules! query {
+    ($id:literal, $label:literal, $params:literal, $run:expr) => {
+        $crate::commands::CommandSpec {
+            id: $id,
+            label: $label,
+            menu: &[],
+            shortcut: None,
+            alt_shortcuts: &[],
+            params: $params,
+            enabled: $crate::commands::always,
+            run: $run,
+            journal: false,
+        }
+    };
+}
+
+mod enabled;
+mod params;
+mod schema;
+
+use super::commands;
+pub use enabled::always;
+pub(crate) use enabled::{has_comp, has_keys, has_layers, has_project_selection, not_yet, not_yet_run};
+pub use params::match_path_of;
+pub(crate) use params::{
+    b_p, bad, comp_id, f_p, frontend, layer_mut, layer_p, layers_p, merge_p, resolve_effect_path, resolve_layer, selectable, selected_leaf_props, str_p,
+    time_p, unlocked, visible_p,
+};
+pub use schema::{accepted_params, check_params, params_schema};
+
+pub fn command_specs() -> &'static [CommandSpec] {
+    static SPECS: OnceLock<Vec<CommandSpec>> = OnceLock::new();
+    SPECS.get_or_init(|| {
+        let mut v = Vec::new();
+        v.extend(file::specs());
+        v.extend(crate::models::specs());
+        v.extend(edit::specs());
+        v.extend(comp::specs());
+        v.extend(layer::specs());
+        v.extend(styles::specs());
+        v.extend(three_d::specs());
+        v.extend(model3d::specs());
+        v.extend(rig3d::specs());
+        v.extend(text_anim::specs());
+        v.extend(text_edit::specs());
+        v.extend(layer_time::specs());
+        v.extend(prop::specs());
+        v.extend(prop_groups::specs());
+        v.extend(project_items::specs());
+        v.extend(anim::specs());
+        v.extend(anim_tools::specs());
+        v.extend(link::specs());
+        v.extend(markers::specs());
+        v.extend(mask::specs());
+        v.extend(paths::specs());
+        v.extend(effect::specs());
+        v.extend(time::specs());
+        v.extend(nav_more::specs());
+        v.extend(render_queue::specs());
+        v.extend(help::specs());
+        v.extend(query::specs());
+        v.extend(batch::specs());
+        v.extend(layer_menu::specs());
+        v.extend(create::specs());
+        v.extend(animation::specs());
+        v.extend(anim_presets::specs());
+        v.extend(view::specs());
+        v.extend(viewer_cmds::specs());
+        v.extend(shape_stroke::specs());
+        v.extend(shape_tool::specs());
+        v.extend(focus::specs());
+        v.extend(key_labels::specs());
+        v.extend(key_transform::specs());
+        v.extend(quick_offset::specs());
+        v.extend(file_more::specs());
+        v.extend(relink::specs());
+        v.extend(relink_moved::specs());
+        v.extend(lottie::specs());
+        v.extend(import_project::specs());
+        v.extend(timeline::specs());
+        v.extend(comp_more::specs());
+        v.extend(frame_export::specs());
+        v.extend(watch_folder::specs());
+        v.extend(vpe::specs());
+        v.extend(path_nulls::specs());
+        v.extend(vr_editor::specs());
+        v.extend(frontend::specs());
+        v.extend(track::specs());
+        v.extend(mask_interp::specs());
+        v.extend(warp_cmds::specs());
+        v.extend(camera_cmds::specs());
+        v.extend(roto_cmds::specs());
+        v.extend(paint::specs());
+        v.extend(puppet::specs());
+        v.extend(liquify::specs());
+        v.extend(settings::specs());
+        v.extend(app_more::specs());
+        v.extend(keys_more::specs());
+        v.extend(essential::specs());
+        v.extend(expr_tools::specs());
+        v.extend(proxy::specs());
+        v.extend(scripts::specs());
+        v.extend(panels_cmds::specs());
+        v.extend(footage_panel::specs());
+        v.extend(autotrace::specs());
+        v.extend(scene_detect::specs());
+        v.extend(align_data::specs());
+        v.extend(align::specs());
+        v.extend(content_fill::specs());
+        v.extend(stubs::specs());
+        v.extend(crate::storage::specs());
+        v.extend(crate::learn::specs());
+        v.extend(crate::templates::specs());
+        v.extend(crate::preview::specs());
+        v
+    })
+}
+
+/// Set `footage` as the proxy of `item` (File ▸ Create Proxy's post-render action).
+pub(crate) fn proxy_set(s: &mut Session, item: ItemId, footage: effectcraft_project::Footage) -> Result<()> {
+    proxy::set_proxy_footage(s, &[item], footage)
+}
+
+/// (id, name) of the text animation presets.
+pub fn text_preset_list() -> Vec<(String, String)> {
+    text_anim::preset_names()
+}
+
+/// (id, name, category) of the built-in animation presets (Transitions…).
+pub fn builtin_preset_list() -> Vec<(String, String, String)> {
+    anim_presets::preset_names()
+}
+
+pub fn find(id: &str) -> Option<&'static CommandSpec> {
+    // Every command execution looks its spec up: index the ~2,000 ids once.
+    static INDEX: OnceLock<std::collections::HashMap<&'static str, usize>> = OnceLock::new();
+    let index = INDEX.get_or_init(|| {
+        let mut m = std::collections::HashMap::new();
+        for (i, c) in command_specs().iter().enumerate() {
+            m.entry(c.id).or_insert(i);
+        }
+        m
+    });
+    index.get(id).map(|&i| &command_specs()[i])
+}
+
+/// Font families available to text layers (bundled + scanned system fonts).
+/// Text animation presets: (id, name), for menus.
+pub fn text_presets() -> Vec<(String, String)> {
+    commands::text_preset_list()
+}
+
+/// Built-in animation presets (Effects & Presets ▸ * Animation Presets): (id, name, category).
+pub fn animation_presets() -> Vec<(String, String, String)> {
+    commands::builtin_preset_list()
+}
diff --git a/crates/engine/src/commands/align.rs b/crates/engine/src/cmd/align.rs
similarity index 100%
rename from crates/engine/src/commands/align.rs
rename to crates/engine/src/cmd/align.rs
diff --git a/crates/engine/src/commands/align_data.rs b/crates/engine/src/cmd/align_data.rs
similarity index 96%
rename from crates/engine/src/commands/align_data.rs
rename to crates/engine/src/cmd/align_data.rs
index 38d9e7841..99ed3d113 100644
--- a/crates/engine/src/commands/align_data.rs
+++ b/crates/engine/src/cmd/align_data.rs
@@ -72,9 +72,9 @@ pub fn parse_stamp(v: &Value, fps: f64) -> Option<Stamp> {
             }
             // ISO 8601: date [T| ] time [zone].
             if s.len() >= 10 && s.as_bytes()[4] == b'-' && s.as_bytes()[7] == b'-' {
-                let (y, m, d) = (s[0..4].parse::<i64>().ok()?, s[5..7].parse::<i64>().ok()?, s[8..10].parse::<i64>().ok()?);
+                let (y, m, d) = (s.get(0..4)?.parse::<i64>().ok()?, s.get(5..7)?.parse::<i64>().ok()?, s.get(8..10)?.parse::<i64>().ok()?);
                 let mut secs = days_from_civil(y, m, d)? as f64 * 86_400.0;
-                let rest = s[10..].trim_start_matches(['T', 't', ' ']);
+                let rest = s.get(10..)?.trim_start_matches(['T', 't', ' ']);
                 if !rest.is_empty() {
                     // Zone: Z or ±hh:mm / ±hhmm.
                     let (time, zone) = match rest.find(['Z', 'z', '+']).or_else(|| rest.rfind('-')) {
@@ -229,6 +229,12 @@ pub fn specs() -> Vec<CommandSpec> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn multibyte_date_is_rejected() {
+        assert_eq!(parse_stamp(&json!("2026-05-0é"), 25.0), None);
+        assert_eq!(parse_stamp(&json!("2026-05-01é"), 25.0), None);
+    }
+
     #[test]
     fn parses_timestamps() {
         let p = |v: Value| parse_stamp(&v, 25.0).unwrap();
diff --git a/crates/engine/src/commands/anim.rs b/crates/engine/src/cmd/anim.rs
similarity index 100%
rename from crates/engine/src/commands/anim.rs
rename to crates/engine/src/cmd/anim.rs
diff --git a/crates/engine/src/commands/anim_presets.rs b/crates/engine/src/cmd/anim_presets.rs
similarity index 100%
rename from crates/engine/src/commands/anim_presets.rs
rename to crates/engine/src/cmd/anim_presets.rs
diff --git a/crates/engine/src/commands/anim_tools.rs b/crates/engine/src/cmd/anim_tools.rs
similarity index 100%
rename from crates/engine/src/commands/anim_tools.rs
rename to crates/engine/src/cmd/anim_tools.rs
diff --git a/crates/engine/src/commands/animation.rs b/crates/engine/src/cmd/animation.rs
similarity index 100%
rename from crates/engine/src/commands/animation.rs
rename to crates/engine/src/cmd/animation.rs
diff --git a/crates/engine/src/commands/app_more.rs b/crates/engine/src/cmd/app_more.rs
similarity index 100%
rename from crates/engine/src/commands/app_more.rs
rename to crates/engine/src/cmd/app_more.rs
diff --git a/crates/engine/src/commands/autotrace.rs b/crates/engine/src/cmd/autotrace.rs
similarity index 100%
rename from crates/engine/src/commands/autotrace.rs
rename to crates/engine/src/cmd/autotrace.rs
diff --git a/crates/engine/src/commands/batch.rs b/crates/engine/src/cmd/batch.rs
similarity index 100%
rename from crates/engine/src/commands/batch.rs
rename to crates/engine/src/cmd/batch.rs
diff --git a/crates/engine/src/commands/camera_cmds.rs b/crates/engine/src/cmd/camera_cmds.rs
similarity index 100%
rename from crates/engine/src/commands/camera_cmds.rs
rename to crates/engine/src/cmd/camera_cmds.rs
diff --git a/crates/engine/src/commands/comp.rs b/crates/engine/src/cmd/comp.rs
similarity index 100%
rename from crates/engine/src/commands/comp.rs
rename to crates/engine/src/cmd/comp.rs
diff --git a/crates/engine/src/commands/comp_more.rs b/crates/engine/src/cmd/comp_more.rs
similarity index 100%
rename from crates/engine/src/commands/comp_more.rs
rename to crates/engine/src/cmd/comp_more.rs
diff --git a/crates/engine/src/commands/content_fill.rs b/crates/engine/src/cmd/content_fill.rs
similarity index 100%
rename from crates/engine/src/commands/content_fill.rs
rename to crates/engine/src/cmd/content_fill.rs
diff --git a/crates/engine/src/commands/create.rs b/crates/engine/src/cmd/create.rs
similarity index 100%
rename from crates/engine/src/commands/create.rs
rename to crates/engine/src/cmd/create.rs
diff --git a/crates/engine/src/commands/edit.rs b/crates/engine/src/cmd/edit.rs
similarity index 99%
rename from crates/engine/src/commands/edit.rs
rename to crates/engine/src/cmd/edit.rs
index d0dbabb5b..0130aff70 100644
--- a/crates/engine/src/commands/edit.rs
+++ b/crates/engine/src/cmd/edit.rs
@@ -847,10 +847,12 @@ pub(crate) fn disk_stats(s: &mut Session, _: &Value) -> Result<Value> {
         "layers": dc.keys(effectcraft_render::disk_cache::Kind::Layer).len(),
         "bytes": st.bytes,
         "maxBytes": st.max_bytes,
+        "limitBytes": st.limit_bytes,
         "hits": st.hits,
         "misses": st.misses,
         "writes": st.writes,
         "evictions": st.evictions,
+        "failed": st.failed,
     }))
 }
 
diff --git a/crates/engine/src/commands/effect.rs b/crates/engine/src/cmd/effect.rs
similarity index 71%
rename from crates/engine/src/commands/effect.rs
rename to crates/engine/src/cmd/effect.rs
index 4f263b6fb..0a1354fd6 100644
--- a/crates/engine/src/commands/effect.rs
+++ b/crates/engine/src/cmd/effect.rs
@@ -190,6 +190,7 @@ fn pick_color(s: &mut Session, p: &Value) -> Result<Value> {
 /// Cryptomatte layer, with the aux channels (for the manifest) and the effect's Selection.
 struct CryptoHit {
     at: (effectcraft_project::ItemId, LayerId, Tick),
+    probe: std::sync::Arc<CryptoProbe>,
     aux: std::sync::Arc<effectcraft_raster::AuxChannels>,
     layer: String,
     hash: u32,
@@ -210,13 +211,135 @@ impl CryptoHit {
     }
 }
 
-/// The ID under `{x, y}` (effect space, which is layer space on footage and precomp layers) for
-/// the Cryptomatte effect `{layer?, effect?}`, from the aux channels its render reads. The point
-/// snaps to the centre of the pixel the effect's input buffer samples in a render at `scale`
-/// (the viewer's resolution).
-fn crypto_hit(s: &Session, p: &Value, cmd: &str) -> Result<Option<CryptoHit>> {
+/// What a pick at one frame needs besides the point: the aux channels the Cryptomatte effect
+/// reads, its layer, and the effect's input buffer grid (scale, offset). Building it can render
+/// (a precomp's ID pass, the effects before the Cryptomatte effect); a point lookup in it is a
+/// few array reads. The session keeps the last one (see [`Session::crypto_probe_job`]).
+pub struct CryptoProbe {
+    key: ProbeKey,
+    grid: std::result::Result<ProbeGrid, String>,
+}
+
+#[derive(Clone)]
+struct ProbeGrid {
+    aux: std::sync::Arc<effectcraft_raster::AuxChannels>,
+    layer: String,
+    scale: f64,
+    offset: [f64; 2],
+}
+
+/// What a probe depends on: the project revision, the effect (and its index), the frame, the
+/// scale and the render prefs ([`Session::render_opts`]: nested switches, draft shadows).
+#[derive(Clone, Copy, PartialEq, Debug)]
+struct ProbeKey {
+    revision: u64,
+    at: (effectcraft_project::ItemId, LayerId, Uid, usize),
+    frame: ProbeFrame,
+    scale: f64,
+    prefs: (bool, bool),
+}
+
+/// The frame a probe reads. On footage whose masks and effects up to the Cryptomatte effect
+/// don't change over time, its source frame: a still has one, held or remapped frames share
+/// theirs. Otherwise the comp time.
+#[derive(Clone, Copy, PartialEq, Debug)]
+enum ProbeFrame {
+    Source(i64),
+    Comp(Tick),
+}
+
+/// The session's kept probe, and the generation of the latest request: a build stores its
+/// result only while no newer request or edit came since.
+#[derive(Default)]
+pub struct CryptoProbeSlot {
+    probe: Option<std::sync::Arc<CryptoProbe>>,
+    want: Option<ProbeKey>,
+    generation: u64,
+    /// Jobs run (each on its thread), and those that built (not cancelled before they began).
+    jobs: u64,
+    builds: u64,
+}
+
+impl CryptoProbeSlot {
+    /// Drop the kept probe and cancel builds in flight.
+    pub(crate) fn clear(&mut self) {
+        (self.probe, self.want) = (None, None);
+        self.generation += 1;
+    }
+    pub(crate) fn kept(&self) -> bool {
+        self.probe.is_some()
+    }
+    pub(crate) fn builds(&self) -> (u64, u64) {
+        (self.jobs, self.builds)
+    }
+}
+
+/// A probe built off the UI thread into the session's slot.
+pub type CryptoProbeJob = Box<dyn FnOnce() + Send>;
+
+const NO_CRYPTO: &str = "this layer has no Cryptomatte channels (a multi-layer OpenEXR with Cryptomatte, or a 3D precomp)";
+
+impl CryptoProbe {
+    /// `None` when `live` turns false between its stages (a newer request or an edit since):
+    /// a cancelled build stops early and lets go of what it read.
+    fn build(r: &effectcraft_render::Renderer, key: ProbeKey, time: Tick, live: &dyn Fn() -> bool) -> Option<CryptoProbe> {
+        let (cid, lid, _, pos) = key.at;
+        let build = || -> std::result::Result<Option<ProbeGrid>, String> {
+            let comp = r.project.comp(cid).ok_or("no composition")?;
+            let layer = comp.layer(lid).ok_or("no such layer")?;
+            let g = layer.effects().and_then(|fx| fx.groups().nth(pos)).ok_or("no such effect")?;
+            let ctx = effectcraft_render::EvalCtx { project: r.project, comp_id: cid, comp, time, expr: r.expr, footage: None };
+            let params = effectcraft_effects::flatten_params(g, &mut |pr| ctx.value(layer, pr));
+            let want = effectcraft_effects::CRYPTO_LAYERS.get(params.e("layer") as usize).copied().unwrap_or("CryptoAsset");
+            let aux = r.layer_aux(&ctx, layer).ok_or(NO_CRYPTO)?;
+            if !live() {
+                return Ok(None);
+            }
+            let layer_name = aux.resolve_crypto_layer(want).ok_or(NO_CRYPTO)?;
+            // The grid of the effect's input buffer (footage keeps native pixels from 3/4 scale
+            // up, proxies have their own size, earlier effects can pad it), rendered and cached.
+            if !live() {
+                return Ok(None);
+            }
+            let b = r.layer_input(&ctx, layer, pos).ok_or("this layer has no pixels")?;
+            Ok(Some(ProbeGrid { aux, layer: layer_name, scale: b.scale, offset: b.offset }))
+        };
+        // On another thread no command guard runs: a panic becomes the probe's error.
+        let grid = crate::guard::guarded("Reading the Cryptomatte IDs", || Ok(build())).unwrap_or_else(|e| Err(e.to_string()));
+        Some(CryptoProbe { key, grid: grid.transpose()? })
+    }
+}
+
+/// Whether a property in `g` other than `skip` changes over time (keyframes or an expression).
+fn moves(g: &PropGroup, skip: Option<Uid>) -> bool {
+    g.children.iter().any(|c| match c {
+        effectcraft_project::Node::Prop(p) => Some(p.uid) != skip && (p.is_animated() || p.has_expression()),
+        effectcraft_project::Node::Group(g) => moves(g, skip),
+    })
+}
+
+/// [`ProbeFrame`] of the effect at index `pos` of `layer`.
+fn probe_frame(ctx: &effectcraft_render::EvalCtx, layer: &Layer, pos: usize) -> ProbeFrame {
+    let comp = ProbeFrame::Comp(ctx.time);
+    let effectcraft_project::LayerSource::Footage { item } = layer.source else { return comp };
+    let Some(effectcraft_project::ItemKind::Footage(f)) = ctx.project.item(item).map(|i| &i.kind) else { return comp };
+    let fx = layer.effects().into_iter().flat_map(|fx| fx.groups().take(pos + 1));
+    let time_fx = |g: &PropGroup| matches!(&g.kind, GroupKind::Effect { effect } if effect.starts_with("ec.time."));
+    let still = f.kind == effectcraft_project::FootageKind::Still;
+    let blend = !still && ctx.comp.enable_frame_blending && layer.switches.frame_blend != effectcraft_project::FrameBlend::Off;
+    // The Cryptomatte effect's own Selection isn't read by the probe: animated, it keeps it.
+    let own = |i: usize, g: &PropGroup| if i == pos { g.prop("selection").map(|p| p.uid) } else { None };
+    if blend || layer.masks().is_some_and(|m| moves(m, None)) || fx.enumerate().any(|(i, g)| moves(g, own(i, g)) || time_fx(g)) {
+        return comp;
+    }
+    ProbeFrame::Source(if still { 0 } else { effectcraft_render::frame_position(ctx.source_time(layer), f.frame_rate).0 })
+}
+
+/// The Cryptomatte effect `{layer?, effect?, scale?, time?}` names: its probe key, the comp
+/// time, its layer, group and Selection property.
+#[allow(clippy::type_complexity)]
+fn probe_key<'a>(s: &'a Session, p: &Value, cmd: &str) -> Result<(ProbeKey, Tick, &'a Layer, &'a PropGroup, &'a effectcraft_project::Property)> {
     let (cid, lid, fx_uid) = find_fx(s, p, cmd)?;
-    let (Some(x), Some(y)) = (f_p(p, "x"), f_p(p, "y")) else { return Err(bad(cmd, "missing `x` / `y` (layer pixels)")) };
     let scale = f_p(p, "scale").unwrap_or(1.0);
     if !(scale.is_finite() && scale > 0.0 && scale <= 1.0) {
         return Err(bad(cmd, "`scale` is the preview's resolution factor, above 0 and at most 1"));
@@ -227,30 +350,175 @@ fn crypto_hit(s: &Session, p: &Value, cmd: &str) -> Result<Option<CryptoHit>> {
     let pos = fx.groups().position(|g| g.uid == fx_uid).ok_or_else(|| bad(cmd, "no such effect"))?;
     let g = fx.groups().nth(pos).ok_or_else(|| bad(cmd, "no such effect"))?;
     let prop = g.prop("selection").filter(|_| g.match_id == "ec.3d.cryptomatte").ok_or_else(|| bad(cmd, "not a Cryptomatte effect"))?;
-    let t = super::time_p(s, p, Some(comp));
-    let ctx = effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time: t, expr: s.expr.as_deref(), footage: None };
-    let params = effectcraft_effects::flatten_params(g, &mut |pr| ctx.value(layer, pr));
-    let r = s.renderer(effectcraft_render::RenderOpts { scale, ..Default::default() });
-    let aux = r.layer_aux(&ctx, layer);
-    let want = effectcraft_effects::CRYPTO_LAYERS.get(params.e("layer") as usize).copied().unwrap_or("CryptoAsset");
-    let Some((aux, layer_name)) = aux.and_then(|a| a.resolve_crypto_layer(want).map(|l| (a, l))) else {
-        return Err(bad(cmd, "this layer has no Cryptomatte channels (a multi-layer OpenEXR with Cryptomatte, or a 3D precomp)"));
+    let time = super::time_p(s, p, Some(comp));
+    let ctx = effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time, expr: s.expr.as_deref(), footage: None };
+    let frame = probe_frame(&ctx, layer, pos);
+    let o = s.render_opts(Default::default());
+    let prefs = (o.nested_switches, o.draft_shadows);
+    Ok((ProbeKey { revision: s.revision, at: (cid, lid, fx_uid, pos), frame, scale, prefs }, time, layer, g, prop))
+}
+
+/// The kept probe if it answers for the current revision, for [`keep_crypto_probe`] (taken
+/// before an undo, redo or history jump).
+pub(crate) fn kept_crypto_probe(s: &Session) -> Option<std::sync::Arc<CryptoProbe>> {
+    s.crypto_probe.lock().ok()?.probe.clone().filter(|p| p.key.revision == s.revision)
+}
+
+/// After an undo, redo or history jump from `before` (which dropped the probe): `kept`, the
+/// probe from before, still answers when only Cryptomatte Selections changed, which the probe
+/// doesn't read (undoing a pick, as the pick itself keeps it).
+pub(crate) fn keep_crypto_probe(s: &Session, kept: Option<std::sync::Arc<CryptoProbe>>, before: &effectcraft_project::Project) {
+    let Some(p) = kept else { return };
+    if !only_crypto_selections_differ(before, &s.project) {
+        return;
+    }
+    if let Ok(mut slot) = s.crypto_probe.lock()
+        && slot.probe.is_none()
+    {
+        slot.probe = Some(std::sync::Arc::new(CryptoProbe { key: ProbeKey { revision: s.revision, ..p.key }, grid: p.grid.clone() }));
+    }
+}
+
+/// Whether projects `a` and `b` differ at most in the Selections of Cryptomatte effects.
+fn only_crypto_selections_differ(a: &effectcraft_project::Project, b: &effectcraft_project::Project) -> bool {
+    let mut x = a.clone();
+    for (cid, it) in x.items.iter_mut() {
+        let effectcraft_project::ItemKind::Comp(c) = &mut it.kind else { continue };
+        let sels: Vec<(LayerId, Uid)> = c
+            .layers
+            .iter()
+            .flat_map(|l| {
+                l.effects()
+                    .into_iter()
+                    .flat_map(|fx| fx.groups())
+                    .filter(|g| g.match_id == "ec.3d.cryptomatte")
+                    .filter_map(move |g| g.get("selection").map(|p| (l.id, p.uid)))
+            })
+            .collect();
+        if sels.is_empty() {
+            continue;
+        }
+        let Some(bc) = b.comp(*cid) else { return false };
+        let c = std::sync::Arc::make_mut(c);
+        for (lid, uid) in sels {
+            let Some(src) = bc.layer(lid).and_then(|l| l.props.find(uid)) else { return false };
+            if let Some(dst) = c.layer_mut(lid).and_then(|l| l.props.find_mut(uid)) {
+                *dst = src.clone();
+            }
+        }
+    }
+    x.same_content(b)
+}
+
+/// The session's probe when it has `key`'s.
+fn cached_probe(s: &Session, key: ProbeKey) -> Option<std::sync::Arc<CryptoProbe>> {
+    s.crypto_probe.lock().ok()?.probe.clone().filter(|p| p.key == key)
+}
+
+/// [`Session::crypto_probe_ready`].
+pub(crate) fn crypto_probe_ready(s: &Session, p: &Value) -> Result<bool> {
+    let (key, ..) = probe_key(s, p, "effect.cryptomatteAt")?;
+    Ok(cached_probe(s, key).is_some())
+}
+
+/// [`Session::crypto_probe_job`].
+pub(crate) fn crypto_probe_job(s: &Session, p: &Value) -> Result<Option<CryptoProbeJob>> {
+    let (key, time, ..) = probe_key(s, p, "effect.cryptomatteAt")?;
+    let generation = {
+        let mut slot = s.crypto_probe.lock().map_err(|_| EngineError::Other("the Cryptomatte probe is unavailable".into()))?;
+        if slot.probe.as_ref().is_some_and(|p| p.key == key) {
+            return Ok(None);
+        }
+        // A request for another probe cancels the one in flight.
+        if slot.want != Some(key) {
+            (slot.want, slot.generation) = (Some(key), slot.generation + 1);
+        }
+        slot.generation
     };
-    // The grid of the effect's input buffer (footage keeps native pixels from 3/4 scale up,
-    // proxies have their own size, earlier effects can pad it), rendered and cached.
-    let b = r.layer_input(&ctx, layer, pos).ok_or_else(|| bad(cmd, "this layer has no pixels"))?;
+    let (project, footage, expr, cache, accel, slot) =
+        (s.project.clone(), s.footage.clone(), s.expr.clone(), s.layer_cache.clone(), s.accel.clone(), s.crypto_probe.clone());
+    let opts = s.render_opts(effectcraft_render::RenderOpts { scale: key.scale, ..Default::default() });
+    // The slot while this is still the newest request.
+    fn current(slot: &std::sync::Mutex<CryptoProbeSlot>, generation: u64) -> Option<std::sync::MutexGuard<'_, CryptoProbeSlot>> {
+        slot.lock().ok().filter(|s| s.generation == generation)
+    }
+    Ok(Some(Box::new(move || {
+        match slot.lock() {
+            Ok(mut s) if s.generation == generation => (s.jobs, s.builds) = (s.jobs + 1, s.builds + 1),
+            Ok(mut s) => return s.jobs += 1,
+            Err(_) => return,
+        }
+        let mut r = effectcraft_render::Renderer::new(&project, footage.as_ref(), opts);
+        r.expr = expr.as_deref();
+        r.cache = Some(&cache);
+        r.accel = accel.as_deref();
+        // Checked between its stages too: a superseded build stops at the next one.
+        let Some(probe) = CryptoProbe::build(&r, key, time, &|| current(&slot, generation).is_some()) else { return };
+        let probe = std::sync::Arc::new(probe);
+        // Only the newest request's result, and never over a newer probe.
+        if let Some(mut s) = current(&slot, generation)
+            && s.probe.as_ref().is_none_or(|p| p.key.revision <= key.revision)
+        {
+            s.probe = Some(probe);
+        }
+    })))
+}
+
+/// What a pick finds at a point.
+enum Hit {
+    /// `probeOnly` and the probe isn't built yet.
+    Pending,
+    Nothing,
+    Id(CryptoHit),
+}
+
+/// The ID under `{x, y}` (effect space, which is layer space on footage and precomp layers) for
+/// the Cryptomatte effect `{layer?, effect?}`, from the aux channels its render reads. The point
+/// snaps to the centre of the pixel the effect's input buffer samples in a render at `scale`
+/// (the viewer's resolution). Without a kept probe it builds one, unless `probeOnly`.
+fn crypto_hit(s: &Session, p: &Value, cmd: &str) -> Result<Hit> {
+    let (key, time, layer, g, prop) = probe_key(s, p, cmd)?;
+    let (Some(x), Some(y)) = (f_p(p, "x"), f_p(p, "y")) else { return Err(bad(cmd, "missing `x` / `y` (layer pixels)")) };
+    let probe = match cached_probe(s, key) {
+        Some(probe) => probe,
+        None if b_p(p, "probeOnly").unwrap_or(false) => return Ok(Hit::Pending),
+        None => {
+            let r = s.renderer(effectcraft_render::RenderOpts { scale: key.scale, ..Default::default() });
+            if let Ok(mut slot) = s.crypto_probe.lock() {
+                slot.clear();
+                slot.builds += 1;
+            }
+            // (Never cancelled here: nothing else runs on this thread.)
+            let Some(probe) = CryptoProbe::build(&r, key, time, &|| true).map(std::sync::Arc::new) else { return Ok(Hit::Pending) };
+            if let Ok(mut slot) = s.crypto_probe.lock() {
+                slot.probe = Some(probe.clone());
+            }
+            probe
+        }
+    };
+    let b = probe.grid.as_ref().map_err(|e| bad(cmd, e.clone()))?;
     let (bs, o) = (b.scale, b.offset);
     // The centre of its pixel under the point, at the aux point the effect reads there.
     let [ax, ay] = effectcraft_effects::aux_point(bs, o, [(x * bs + o[0]).floor() + 0.5, (y * bs + o[1]).floor() + 0.5]);
-    let Some(hash) = aux.index_at(ax, ay).and_then(|i| aux.crypto_id_at(&layer_name, i)) else { return Ok(None) };
-    let (selection, driven) = (params.s("selection").to_string(), prop.expr.as_ref().is_some_and(|e| e.enabled));
-    Ok(Some(CryptoHit { at: (cid, lid, t), aux, layer: layer_name, hash, selection, prop: prop.uid, driven }))
+    let Some(hash) = b.aux.index_at(ax, ay).and_then(|i| b.aux.crypto_id_at(&b.layer, i)) else { return Ok(Hit::Nothing) };
+    let (cid, lid, ..) = key.at;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let ctx = effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time, expr: s.expr.as_deref(), footage: None };
+    let selection = effectcraft_effects::flatten_params(g, &mut |pr| ctx.value(layer, pr)).s("selection").to_string();
+    let driven = prop.expr.as_ref().is_some_and(|e| e.enabled);
+    let (aux, layer_name) = (b.aux.clone(), b.layer.clone());
+    Ok(Hit::Id(CryptoHit { at: (cid, lid, time), probe: probe.clone(), aux, layer: layer_name, hash, selection, prop: prop.uid, driven }))
 }
 
 /// `effect.cryptomatteAt`: the ID under a point, for the viewer's hover hint. The first call per
-/// frame renders the effect's input to learn its pixel grid (cached afterwards).
+/// frame renders the effect's input to learn its pixel grid (kept afterwards); with `probeOnly`
+/// it answers `{pending: true}` instead.
 fn crypto_at(s: &mut Session, p: &Value) -> Result<Value> {
-    Ok(crypto_hit(s, p, "effect.cryptomatteAt")?.map_or(Value::Null, |h| h.reply(&h.selection)))
+    Ok(match crypto_hit(s, p, "effect.cryptomatteAt")? {
+        Hit::Pending => json!({"pending": true}),
+        Hit::Nothing => Value::Null,
+        Hit::Id(h) => h.reply(&h.selection),
+    })
 }
 
 /// The Cryptomatte eyedropper: replace the effect's Selection with the ID under a point, add it
@@ -264,7 +532,11 @@ fn pick_crypto(s: &mut Session, p: &Value) -> Result<Value> {
         "remove" => PickMode::Remove,
         m => return Err(bad(cmd, format!("unknown `mode` {m:?} (replace, add or remove)"))),
     };
-    let h = crypto_hit(s, p, cmd)?.ok_or_else(|| bad(cmd, "no Cryptomatte ID there (empty or outside the layer)"))?;
+    let h = match crypto_hit(s, p, cmd)? {
+        Hit::Id(h) => h,
+        Hit::Pending => return Ok(json!({"pending": true, "changed": false})),
+        Hit::Nothing => return Err(bad(cmd, "no Cryptomatte ID there (empty or outside the layer)")),
+    };
     if h.driven {
         return Err(bad(cmd, "the Selection is driven by an expression; disable it to pick"));
     }
@@ -274,6 +546,19 @@ fn pick_crypto(s: &mut Session, p: &Value) -> Result<Value> {
     if changed {
         let (cid, lid, t) = h.at;
         s.execute("prop.set", json!({"comp": cid.0, "layer": lid.0, "prop": h.prop, "value": sel, "time": t.seconds(), "timeBase": "comp"}))?;
+        // The step says what made it (Edit ▸ Undo Pick Cryptomatte, the History panel), not
+        // "Change Property" like any other edit. (A changed Selection is always a new step.)
+        if let Some(step) = s.history.undo.last_mut() {
+            step.0 = "Pick Cryptomatte".into();
+        }
+        // Only the Selection changed, which the probe doesn't read: the next hover keeps it.
+        // (The edit dropped it; a probe built since is newer.)
+        if let Ok(mut slot) = s.crypto_probe.lock()
+            && slot.probe.is_none()
+        {
+            let key = ProbeKey { revision: s.revision, ..h.probe.key };
+            slot.probe = Some(std::sync::Arc::new(CryptoProbe { key, grid: h.probe.grid.clone() }));
+        }
     }
     let mut out = h.reply(&sel);
     out["selection"] = json!(sel);
@@ -732,14 +1017,14 @@ pub fn specs() -> Vec<CommandSpec> {
             "Pick Cryptomatte",
             [],
             None,
-            "{layer?, effect?: index|uid|name, x, y (effect space), mode?: replace|add|remove (default replace), scale? (preview resolution, default 1), time?} → {name, hash, layer, selection, changed, selected} — edits the Cryptomatte effect's Selection with the ID under the point",
+            "{layer?, effect?: index|uid|name, x, y (effect space), mode?: replace|add|remove (default replace), scale? (preview resolution, default 1), time?, probeOnly?} → {name, hash, layer, selection, changed, selected} | {pending} — edits the Cryptomatte effect's Selection with the ID under the point",
             has_layers,
             pick_crypto
         ),
         crate::query!(
             "effect.cryptomatteAt",
             "Cryptomatte At",
-            "{layer?, effect?: index|uid|name, x, y (effect space), scale?, time?} → {name, hash, layer, selected} | null — the Cryptomatte ID under the point",
+            "{layer?, effect?: index|uid|name, x, y (effect space), scale?, time?, probeOnly?: bool (don't build the probe)} → {name, hash, layer, selected} | {pending} | null — the Cryptomatte ID under the point",
             crypto_at
         ),
         cmd!("effect.applyLast", "Last Effect", ["Effect"], Some("Cmd+Alt+Shift+E"), "{layers?}", has_layers, last),
diff --git a/crates/engine/src/cmd/enabled.rs b/crates/engine/src/cmd/enabled.rs
new file mode 100644
index 000000000..fb28b60c4
--- /dev/null
+++ b/crates/engine/src/cmd/enabled.rs
@@ -0,0 +1,38 @@
+use super::{EngineError, Result, Session, Value};
+
+// ---------- enablement ----------
+
+pub fn always(_: &Session) -> std::result::Result<(), String> {
+    Ok(())
+}
+
+pub(crate) fn has_comp(s: &Session) -> std::result::Result<(), String> {
+    s.active_comp().map(|_| ()).ok_or_else(|| "no composition is open".into())
+}
+
+pub(crate) fn has_layers(s: &Session) -> std::result::Result<(), String> {
+    has_comp(s)?;
+    if s.state.selected_layers.is_empty() { Err("select a layer first".into()) } else { Ok(()) }
+}
+
+pub(crate) fn has_keys(s: &Session) -> std::result::Result<(), String> {
+    has_comp(s)?;
+    if s.state.selected_keys.is_empty() { Err("select keyframes first".into()) } else { Ok(()) }
+}
+
+pub(crate) fn has_project_selection(s: &Session) -> std::result::Result<(), String> {
+    if s.state.project_selection.is_empty() { Err("select an item in the Project panel first".into()) } else { Ok(()) }
+}
+
+/// Disabled-command enablement (menu entries whose implementation lands with another milestone;
+/// none are left, kept for future stubs).
+#[allow(dead_code)]
+pub(crate) fn not_yet(_: &Session) -> std::result::Result<(), String> {
+    Err("not available yet in EffectCraft".into())
+}
+
+/// `run` of a not-yet-available command.
+#[allow(dead_code)]
+pub(crate) fn not_yet_run(_: &mut Session, _: &Value) -> Result<Value> {
+    Err(EngineError::Other("not available yet in EffectCraft".into()))
+}
diff --git a/crates/engine/src/commands/essential.rs b/crates/engine/src/cmd/essential.rs
similarity index 100%
rename from crates/engine/src/commands/essential.rs
rename to crates/engine/src/cmd/essential.rs
diff --git a/crates/engine/src/commands/expr_tools.rs b/crates/engine/src/cmd/expr_tools.rs
similarity index 100%
rename from crates/engine/src/commands/expr_tools.rs
rename to crates/engine/src/cmd/expr_tools.rs
diff --git a/crates/engine/src/commands/file.rs b/crates/engine/src/cmd/file.rs
similarity index 100%
rename from crates/engine/src/commands/file.rs
rename to crates/engine/src/cmd/file.rs
diff --git a/crates/engine/src/commands/file_more.rs b/crates/engine/src/cmd/file_more.rs
similarity index 96%
rename from crates/engine/src/commands/file_more.rs
rename to crates/engine/src/cmd/file_more.rs
index 74a86e1d8..c9d581581 100644
--- a/crates/engine/src/commands/file_more.rs
+++ b/crates/engine/src/cmd/file_more.rs
@@ -430,6 +430,20 @@ fn collect_files(s: &mut Session, p: &Value) -> Result<Value> {
 /// array or JSON lines of `{"command": id, "params": {…}}` (also accepts the control channel's
 /// `{"method": "engine.execute", "params": {"id", "params"}}`).
 fn run_script(s: &mut Session, p: &Value) -> Result<Value> {
+    // File ▸ Scripts ▸ Recent Script Files ▸ <script> (0 is the most recent).
+    if let Some(i) = p.get("recent") {
+        let i = i.as_u64().ok_or_else(|| bad("file.runScript", format!("`recent` must be an index, not {i}")))?;
+        let script = match s.prefs.recent_scripts.get(usize::try_from(i).unwrap_or(usize::MAX)) {
+            Some(x) => x.clone(),
+            None if s.prefs.recent_scripts.is_empty() => return Err(bad("file.runScript", "no recent script files")),
+            None => return Err(bad("file.runScript", format!("no recent script file #{i}"))),
+        };
+        let q = match script {
+            crate::prefs::RecentScript::Path(path) => json!({"path": path}),
+            crate::prefs::RecentScript::Name(name) => json!({"name": name}),
+        };
+        return run_script(s, &q);
+    }
     // File ▸ Scripts ▸ <installed or sample script>.
     if let Some(name) = str_p(p, "name")
         && p.get("path").is_none()
@@ -446,15 +460,22 @@ fn run_script(s: &mut Session, p: &Value) -> Result<Value> {
             return Err(bad("file.runScript", JSXBIN));
         }
         let bytes = s.services.read_file(path).map_err(|e| EngineError::Other(format!("cannot read {path}: {e}")))?;
+        let full = s.services.full_path(path);
         let code = String::from_utf8_lossy(&bytes).to_string();
         let name = std::path::Path::new(path).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| path.to_string());
         let out = run_js(s, &code, path, false)?;
-        return report_js(s, &name, out);
+        let result = report_js(s, &name, out)?;
+        if let Some(full) = full {
+            remember_script(s, crate::prefs::RecentScript::Path(full));
+        }
+        return Ok(result);
     }
+    let mut script_path = None;
     let steps: Vec<Value> = match (p.get("steps"), str_p(p, "path")) {
         (Some(Value::Array(a)), _) => a.clone(),
         (_, Some(path)) => {
             let bytes = s.services.read_file(path).map_err(|e| EngineError::Other(format!("cannot read {path}: {e}")))?;
+            script_path = s.services.full_path(path);
             let text = String::from_utf8_lossy(&bytes).to_string();
             match serde_json::from_str::<Value>(&text) {
                 Ok(Value::Array(a)) => a,
@@ -487,9 +508,19 @@ fn run_script(s: &mut Session, p: &Value) -> Result<Value> {
         let r = r.map_err(|e| EngineError::Other(format!("step {} ({id}): {e}", i + 1)))?;
         results.push(r);
     }
+    if let Some(path) = script_path {
+        remember_script(s, crate::prefs::RecentScript::Path(path));
+    }
     Ok(json!({"steps": results.len(), "results": results}))
 }
 
+/// Remember a script that runs for File ▸ Scripts ▸ Recent Script Files.
+pub(super) fn remember_script(s: &mut Session, script: crate::prefs::RecentScript) {
+    s.prefs.push_recent_script(script);
+    s.save_prefs();
+    s.prefs_revision += 1;
+}
+
 /// `.jsx` / `.js` (and `.jsxbin`, rejected) are JavaScript; `.json` / `.jsonl` / other files are
 /// command scripts.
 fn is_js_script(path: &str) -> bool {
@@ -1017,7 +1048,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Run Script File...",
             ["File", "Scripts"],
             None,
-            "{path (.jsx/.js JavaScript, or a .jsonl/.json command script) | name (an installed or sample script, see file.scripts.list) | steps: [{command, params}]}",
+            "{path (.jsx/.js JavaScript, or a .jsonl/.json command script) | name (an installed or sample script, see file.scripts.list) | recent: index (File ▸ Scripts ▸ Recent Script Files, 0 = the most recent) | steps: [{command, params}]}",
             always,
             run_script
         ),
diff --git a/crates/engine/src/commands/focus.rs b/crates/engine/src/cmd/focus.rs
similarity index 100%
rename from crates/engine/src/commands/focus.rs
rename to crates/engine/src/cmd/focus.rs
diff --git a/crates/engine/src/commands/footage_panel.rs b/crates/engine/src/cmd/footage_panel.rs
similarity index 100%
rename from crates/engine/src/commands/footage_panel.rs
rename to crates/engine/src/cmd/footage_panel.rs
diff --git a/crates/engine/src/commands/frame_export.rs b/crates/engine/src/cmd/frame_export.rs
similarity index 100%
rename from crates/engine/src/commands/frame_export.rs
rename to crates/engine/src/cmd/frame_export.rs
diff --git a/crates/engine/src/commands/frontend.rs b/crates/engine/src/cmd/frontend.rs
similarity index 100%
rename from crates/engine/src/commands/frontend.rs
rename to crates/engine/src/cmd/frontend.rs
diff --git a/crates/engine/src/commands/help.rs b/crates/engine/src/cmd/help.rs
similarity index 100%
rename from crates/engine/src/commands/help.rs
rename to crates/engine/src/cmd/help.rs
diff --git a/crates/engine/src/commands/import_project.rs b/crates/engine/src/cmd/import_project.rs
similarity index 100%
rename from crates/engine/src/commands/import_project.rs
rename to crates/engine/src/cmd/import_project.rs
diff --git a/crates/engine/src/commands/key_labels.rs b/crates/engine/src/cmd/key_labels.rs
similarity index 100%
rename from crates/engine/src/commands/key_labels.rs
rename to crates/engine/src/cmd/key_labels.rs
diff --git a/crates/engine/src/commands/key_transform.rs b/crates/engine/src/cmd/key_transform.rs
similarity index 100%
rename from crates/engine/src/commands/key_transform.rs
rename to crates/engine/src/cmd/key_transform.rs
diff --git a/crates/engine/src/commands/keys_more.rs b/crates/engine/src/cmd/keys_more.rs
similarity index 100%
rename from crates/engine/src/commands/keys_more.rs
rename to crates/engine/src/cmd/keys_more.rs
diff --git a/crates/engine/src/cmd/layer.rs b/crates/engine/src/cmd/layer.rs
new file mode 100644
index 000000000..f6d2feb04
--- /dev/null
+++ b/crates/engine/src/cmd/layer.rs
@@ -0,0 +1,212 @@
+//! Layer menu.
+
+use effectcraft_color::{BlendMode, Label};
+use effectcraft_keyframe::{Justify, TextDoc, Value as KV};
+use effectcraft_project::build::{self, Ids};
+use effectcraft_project::{
+    Comp, FootageKind, FrameBlend, GroupKind, ItemId, ItemKind, Layer, LayerId, LayerSource, MaskMode, MatteKind, Node, Project, PropGroup, Quality, Solid,
+    TrackMatte, limits,
+};
+use effectcraft_time::Tick;
+use serde_json::{Value, json};
+
+use super::{CommandSpec, b_p, bad, comp_id, f_p, has_comp, has_layers, layer_mut, layer_p, layers_p, merge_p, resolve_layer, str_p, unlocked};
+use crate::{EngineError, Result, Session, cmd};
+
+mod contents;
+mod create;
+mod parent;
+mod replace;
+mod select;
+mod switches;
+mod timing;
+mod transform;
+
+use contents::{add_mask, add_shape_item, mask_props, set_text};
+use create::{add_item, new_adjustment, new_null, new_shape, new_solid, new_text};
+pub(crate) use create::{color_p, index_p, insert_layer, insert_layer_at, place, position_p};
+pub(crate) use parent::parent_fixes;
+use parent::set_parent;
+use replace::{has_replace_source, replace_source};
+use select::{select, select_next, select_prev, select_step};
+use switches::{blend, rename, set_comment, set_switch, track_matte};
+use timing::{arrange, move_frames, precompose, slip, timing};
+use transform::{has_layer_settings, layer_settings, transform_op};
+pub(crate) use transform::{offset_position, transform_default, update_position};
+
+/// `p` with `key` set.
+fn with(p: &Value, key: &str, v: Value) -> Value {
+    let mut p = if p.is_object() { p.clone() } else { json!({}) };
+    p[key] = v;
+    p
+}
+
+pub fn specs() -> Vec<CommandSpec> {
+    vec![
+        cmd!(
+            "layer.newText",
+            "Text",
+            ["Layer", "New"],
+            Some("Cmd+Alt+Shift+T"),
+            "{text?, name? (layer name; default the text), position? [x,y], box? [x,y,w,h] (paragraph text, comp space), vertical?, edit? (start editing), font?, style?, size?, fill?, stroke?, applyFill?, applyStroke?, strokeWidth?, tracking?, leading?, baselineShift?, hScale?, vScale?, tsume?, fauxBold?, fauxItalic?, allCaps?, smallCaps?, baseline?, superscript?, subscript?, kerning?, ligatures?, justify?, indentLeft?, indentRight?, indentFirst?, spaceBefore?, spaceAfter?, direction?, composer?, hangingPunctuation?, strokeOverFill?} (attributes as layer.setText)",
+            has_comp,
+            new_text
+        ),
+        cmd!("layer.newSolid", "Solid...", ["Layer", "New"], Some("Cmd+Y"), "{name?, color? #hex|[r,g,b], width?, height?, pixelAspect?}", has_comp, new_solid),
+        cmd!("layer.newNull", "Null Object", ["Layer", "New"], Some("Cmd+Alt+Shift+Y"), "{name?}", has_comp, new_null),
+        cmd!(
+            "layer.newShape",
+            "Shape Layer",
+            ["Layer", "New"],
+            None,
+            "{kind?: rect|rounded|ellipse|star|polygon|none, name?, size?, fill?, fillType?, fillBlend?, fillOpacity?, stroke?, strokeType?, strokeBlend?, strokeOpacity?, strokeWidth?, position?}",
+            has_comp,
+            new_shape
+        ),
+        cmd!("layer.newAdjustment", "Adjustment Layer", ["Layer", "New"], Some("Cmd+Alt+Y"), "{name?}", has_comp, new_adjustment),
+        cmd!(
+            "layer.settings",
+            "Layer Settings...",
+            ["Layer"],
+            Some("Cmd+Shift+Y"),
+            "{layer?, name?, color?, width?, height?, pixelAspect?, affectAll?: bool (default true; false gives this layer its own copy of a solid other layers use)} → {layer, solid?}",
+            has_layer_settings,
+            layer_settings
+        ),
+        cmd!(
+            "layer.addItem",
+            "Add Footage to Comp",
+            ["File"],
+            Some("Cmd+/"),
+            "{item: id|name, time? (s, the In point), index? (1-based stack position; default above the selected layer), position? ([x, y] comp px; default the centre), duration? (s, for a still)}",
+            has_comp,
+            add_item
+        ),
+        cmd!(
+            "layer.replaceSource",
+            "Replace Layer Source",
+            [],
+            Some("Cmd+Alt+/"),
+            "{comp?, layers?, layer?, item?: id|name (default the Project panel selection), fixExpressions?: bool (accepted for After Effects compatibility)} → {layers, item}",
+            has_replace_source,
+            replace_source
+        ),
+        cmd!("layer.select", "Select Layers", [], None, "{layers: [id|name|#n], add?, toggle?}", has_comp, select),
+        cmd!("layer.selectNext", "Select Next Layer", [], Some("Cmd+ArrowDown"), "{add?}", has_comp, select_next),
+        cmd!("layer.selectPrevious", "Select Previous Layer", [], Some("Cmd+ArrowUp"), "{add?}", has_comp, select_prev),
+        cmd!("layer.extendSelectionNext", "Extend Selection to Next Layer", [], Some("Cmd+Shift+ArrowDown"), "{}", has_comp, |s, _| select_step(
+            s,
+            &json!({"add": true}),
+            1
+        )),
+        cmd!("layer.extendSelectionPrevious", "Extend Selection to Previous Layer", [], Some("Cmd+Shift+ArrowUp"), "{}", has_comp, |s, _| select_step(
+            s,
+            &json!({"add": true}),
+            -1
+        )),
+        cmd!(
+            "layer.setSwitch",
+            "Layer Switch",
+            [],
+            None,
+            "{layers?, switch: video|audio|solo|lock|shy|collapse|quality|fx|frameBlend|motionBlur|adjustment|threeD|guide|preserveTransparency, value?, merge?, others? (the named layers alone: the other layers get the opposite state, or come back)}",
+            has_layers,
+            set_switch
+        ),
+        cmd!("layer.rename", "Rename", [], Some("Enter"), "{layer?, name}", has_layers, rename),
+        cmd!("layer.setComment", "Layer Comment", [], None, "{layers?, comment}", has_layers, set_comment),
+        cmd!("layer.setBlendMode", "Blending Mode", [], None, "{layers?, mode?: Normal|Multiply|Screen|…, step?: ±1}", has_layers, blend),
+        cmd!(
+            "layer.setTrackMatte",
+            "Track Matte",
+            [],
+            None,
+            "{layer?, matte: layer|null, kind?: alpha|alphaInverted|luma|lumaInverted}",
+            has_layers,
+            track_matte
+        ),
+        cmd!("layer.setParent", "Parent", [], None, "{layers?, parent: layer|null, compensate?: bool}", has_layers, set_parent),
+        cmd!(
+            "layer.timing",
+            "Layer Timing",
+            [],
+            None,
+            "{layers?, op?: moveInToTime|moveOutToTime|moveInToStart|moveOutToEnd|trimInToTime|trimOutToTime, delta?, start?, in?, out?, inDelta?, outDelta? (seconds, per layer), merge?}",
+            has_layers,
+            timing
+        ),
+        cmd!("layer.moveInToStart", "Move Layer In Point to Beginning of Comp", [], Some("Alt+Home"), "{layers?}", has_layers, |s, p| timing(
+            s,
+            &with(p, "op", json!("moveInToStart"))
+        )),
+        cmd!("layer.moveOutToEnd", "Move Layer Out Point to End of Comp", [], Some("Alt+End"), "{layers?}", has_layers, |s, p| timing(
+            s,
+            &with(p, "op", json!("moveOutToEnd"))
+        )),
+        cmd!("layer.moveEarlier", "Move Layers 1 Frame Earlier", [], Some("Alt+PageUp"), "{layers?}", has_layers, |s, p| move_frames(s, p, -1)),
+        cmd!("layer.moveLater", "Move Layers 1 Frame Later", [], Some("Alt+PageDown"), "{layers?}", has_layers, |s, p| move_frames(s, p, 1)),
+        cmd!("layer.moveEarlier10", "Move Layers 10 Frames Earlier", [], Some("Alt+Shift+PageUp"), "{layers?}", has_layers, |s, p| move_frames(s, p, -10)),
+        cmd!("layer.moveLater10", "Move Layers 10 Frames Later", [], Some("Alt+Shift+PageDown"), "{layers?}", has_layers, |s, p| move_frames(s, p, 10)),
+        cmd!("layer.slip", "Slip Edit", [], None, "{layers?, delta? (seconds) | frames?, merge?}", has_layers, slip),
+        cmd!("layer.slipBack", "Slip Edit 1 Frame Earlier", [], None, "{layers?}", has_layers, |s, p| {
+            let mut p = p.clone();
+            p["frames"] = json!(-1);
+            slip(s, &p)
+        }),
+        cmd!("layer.slipForward", "Slip Edit 1 Frame Later", [], None, "{layers?}", has_layers, |s, p| {
+            let mut p = p.clone();
+            p["frames"] = json!(1);
+            slip(s, &p)
+        }),
+        cmd!("layer.arrange", "Arrange", ["Layer", "Arrange"], None, "{layers?, to: front|forward|backward|back, index?, above?: layer}", has_layers, arrange),
+        cmd!(
+            "layer.precompose",
+            "Pre-compose...",
+            ["Layer"],
+            Some("Cmd+Shift+C"),
+            "{layers?, name?, mode?: move|leave, adjustDuration?, open?}",
+            has_layers,
+            precompose
+        ),
+        cmd!(
+            "layer.addMask",
+            "New Mask",
+            ["Layer", "Mask"],
+            Some("Cmd+Shift+N"),
+            "{layer?, shape?: rect|ellipse|rounded|polygon|star, rect? [x,y,w,h] (layer space; a polygon or star fits its width), mode?}",
+            has_layers,
+            add_mask
+        ),
+        cmd!("layer.setMask", "Mask Mode", [], None, "{layer?, mask: index|uid|name, mode?, inverted?}", has_layers, mask_props),
+        cmd!(
+            "layer.addShapeItem",
+            "Add (Shape)",
+            [],
+            None,
+            "{layer?, kind: group|rect|ellipse|star|polygon|path|fill|stroke|gfill|gstroke|trim|repeater|round|offset|pucker|twist|zigzag|wiggle|merge|frontColor|bevelColor|sideColor|backColor, group?: uid|path} → {uid, path} (frontColor…backColor: the group's Front / Bevel / Side / Back item, which colours that surface of every extruded paint in the group in Advanced 3D)",
+            has_layers,
+            add_shape_item
+        ),
+        cmd!(
+            "layer.setText",
+            "Edit Text",
+            [],
+            None,
+            "{layer?, range?: [start, end] (characters; default all), text?, font?, style?, size?, fill?, stroke?, applyFill?, applyStroke?, strokeWidth?, tracking?, leading?: px|\"auto\", baselineShift? px, hScale? %, vScale? %, tsume? %, fauxBold?, fauxItalic?, allCaps?, smallCaps?, baseline?: normal|superscript|subscript, superscript?, subscript?, kerning?: metrics|optical|number, ligatures?, discretionaryLigatures? (OpenType), contextualAlternates?, stylisticAlternates?, stylisticSets?: [1–20], ss01?, ss02?, ss03?, ss04?, ss05?, ss06?, ss07?, ss08?, ss09?, ss10?, ss11?, ss12?, ss13?, ss14?, ss15?, ss16?, ss17?, ss18?, ss19?, ss20?, swash?, titling?, ordinals?, fractions?, allSmallCaps?, figureStyle?: default|lining|oldStyle, figureWidth?: default|proportional|tabular, figures?, variations?: {tag: value} (variable font axes; null resets), justify?: left|center|right|justifyLeft|justifyCenter|justifyRight|justifyAll, indentLeft?, indentRight?, indentFirst?, spaceBefore?, spaceAfter?, direction?: ltr|rtl, composer?: everyLine|singleLine, hangingPunctuation?, strokeOverFill?, box?: [x,y,w,h]|null (layer space), vertical?}",
+            has_layers,
+            set_text
+        ),
+        cmd!(
+            "layer.transform",
+            "Transform",
+            ["Layer", "Transform"],
+            None,
+            "{layers?, op: reset|center|fit|fitWidth|fitHeight|flipH|flipV}",
+            has_layers,
+            transform_op
+        ),
+    ]
+}
+
+#[allow(dead_code)]
+fn unused(_: &Comp) {}
diff --git a/crates/engine/src/cmd/layer/contents.rs b/crates/engine/src/cmd/layer/contents.rs
new file mode 100644
index 000000000..d8824fc9e
--- /dev/null
+++ b/crates/engine/src/cmd/layer/contents.rs
@@ -0,0 +1,208 @@
+use super::create::{apply_text_params, text_range_p};
+use super::{
+    EngineError, GroupKind, Ids, ItemId, KV, LayerId, MaskMode, Node, Project, PropGroup, Result, Session, TextDoc, Value, b_p, bad, build, json, layer_mut,
+    layer_p, merge_p, str_p,
+};
+
+pub(super) fn add_mask(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, lid) = layer_p(s, p, "layer.addMask")?;
+    let layer = s.project.comp(cid).and_then(|c| c.layer(lid)).ok_or(EngineError::NoComp)?.clone();
+    let (w, h) = effectcraft_render::source_size(&s.project, &layer);
+    let (w, h) = if w == 0 { (400.0, 300.0) } else { (w as f64, h as f64) };
+    let shape = str_p(p, "shape").unwrap_or("rect");
+    let r = p.get("rect").and_then(Value::as_array).map(|a| [0, 1, 2, 3].map(|i| a.get(i).and_then(Value::as_f64).unwrap_or(0.0)));
+    let (cx, cy, rw, rh) = match r {
+        Some([x, y, rw, rh]) => (x + rw / 2.0, y + rh / 2.0, rw, rh),
+        None => (if w > 0.0 { w / 2.0 } else { 0.0 }, h / 2.0, w * 0.6, h * 0.6),
+    };
+    // The shape tools' masks: rectangle, ellipse, rounded rectangle, polygon or star.
+    let path = crate::cmd::shape_tool::mask_path(shape, [cx, cy], [rw, rh])
+        .ok_or_else(|| bad("layer.addMask", format!("unknown shape `{shape}`; one of rect, ellipse, rounded, polygon, star")))?;
+    let mode = str_p(p, "mode").and_then(MaskMode::from_name).unwrap_or(MaskMode::Add);
+    let cycle = s.prefs.appearance.cycle_mask_colors;
+    let uid = s.edit("New Mask", None, |proj, _| {
+        let mut next = proj.next_id;
+        let l = layer_mut(proj, cid, lid)?;
+        let masks = l.props.sub_mut("masks").ok_or_else(|| bad("layer.addMask", "this layer can't have masks"))?;
+        let n = masks.children.len();
+        let g = build::mask(&mut Ids(&mut next), &format!("Mask {}", n + 1), path, mode, crate::prefs::mask_color(cycle, n));
+        let uid = g.uid;
+        masks.children.push(g.into());
+        proj.next_id = next;
+        Ok(uid)
+    })?;
+    Ok(json!({"mask": uid}))
+}
+
+pub(super) fn mask_props(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, lid) = layer_p(s, p, "layer.setMask")?;
+    let target = p.get("mask").cloned().unwrap_or(json!(1));
+    let mode = str_p(p, "mode").and_then(MaskMode::from_name);
+    let inverted = b_p(p, "inverted");
+    s.edit("Mask Settings", None, |proj, _| {
+        let l = layer_mut(proj, cid, lid)?;
+        let masks = l.props.sub_mut("masks").ok_or_else(|| bad("layer.setMask", "the layer has no masks (add one with layer.addMask)"))?;
+        let g = match &target {
+            Value::Number(n) => {
+                let n = n.as_u64().unwrap_or(1);
+                if let Some(i) = masks.children.iter().position(|c| c.uid() == n) {
+                    masks.children[i].as_group_mut()
+                } else {
+                    masks.children.get_mut(n.saturating_sub(1) as usize).and_then(|c| c.as_group_mut())
+                }
+            }
+            Value::String(name) => masks.children.iter_mut().find(|c| c.name() == name).and_then(|c| c.as_group_mut()),
+            _ => None,
+        }
+        .ok_or_else(|| bad("layer.setMask", "no such mask"))?;
+        if let GroupKind::Mask { mode: m, inverted: inv, .. } = &mut g.kind {
+            if let Some(mm) = mode {
+                *m = mm;
+            }
+            if let Some(i) = inverted {
+                *inv = i;
+            }
+        }
+        Ok(())
+    })?;
+    Ok(Value::Null)
+}
+
+pub(super) fn add_shape_item(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, lid) = layer_p(s, p, "layer.addShapeItem")?;
+    let kind = str_p(p, "kind").ok_or_else(|| bad("layer.addShapeItem", "missing `kind`"))?.to_string();
+    // `group`: a uid or a property path (`contents/group`).
+    let group_uid = match p.get("group") {
+        Some(Value::String(path)) => Some(
+            s.project
+                .comp(cid)
+                .and_then(|c| c.layer(lid))
+                .and_then(|l| l.props.group(path))
+                .map(|g| g.uid)
+                .ok_or_else(|| bad("layer.addShapeItem", format!("no group `{path}`")))?,
+        ),
+        v => v.and_then(Value::as_u64),
+    };
+    let uid = s.edit("Add Shape Item", None, |proj, _| {
+        let mut next = proj.next_id;
+        let mut ids = Ids(&mut next);
+        // Front / Bevel / Side / Back ▸ property: into the group's surface item (one per group).
+        if let Some((surface, prop)) = build::shape_surface_kind(&kind) {
+            let target = shape_item_target(proj, cid, lid, group_uid)?;
+            let item = match target.children.iter().position(|c| matches!(c, Node::Group(g) if g.match_id == surface)) {
+                Some(i) => i,
+                None => {
+                    let g = build::shape_surface(&mut ids, surface).ok_or_else(|| bad("layer.addShapeItem", format!("unknown kind `{kind}`")))?;
+                    target.children.push(g.into());
+                    target.children.len() - 1
+                }
+            };
+            let Some(Node::Group(g)) = target.children.get_mut(item) else { return Err(bad("layer.addShapeItem", "no such group")) };
+            if g.get(prop).is_none() {
+                let p = build::shape_surface_prop(&mut ids, prop).ok_or_else(|| bad("layer.addShapeItem", format!("unknown kind `{kind}`")))?;
+                g.children.push(p.into());
+            }
+            let uid = g.uid;
+            proj.next_id = next;
+            return Ok(uid);
+        }
+        let g = match kind.as_str() {
+            "group" => build::shape_group(&mut ids, "Group 1", vec![]),
+            "rect" | "rectangle" => build::shape_rect(&mut ids, [200.0, 200.0], [0.0, 0.0], 0.0),
+            "ellipse" => build::shape_ellipse(&mut ids, [200.0, 200.0], [0.0, 0.0]),
+            "star" => build::shape_star(&mut ids, true, 5.0, [0.0, 0.0], 100.0, 50.0),
+            "polygon" => build::shape_star(&mut ids, false, 5.0, [0.0, 0.0], 100.0, 0.0),
+            "fill" => build::shape_fill(&mut ids, [1.0, 0.0, 0.0, 1.0]),
+            "stroke" => build::shape_stroke(&mut ids, [1.0, 1.0, 1.0, 1.0], 2.0),
+            "path" => build::shape_path(&mut ids, Default::default()),
+            "gfill" | "gradientFill" => build::shape_gradient_fill(&mut ids, false, [-100.0, 0.0], [100.0, 0.0], Default::default()),
+            "gstroke" | "gradientStroke" => build::shape_gradient_stroke(&mut ids, false, [-100.0, 0.0], [100.0, 0.0], Default::default(), 2.0),
+            "trim" | "trimPaths" => build::shape_trim(&mut ids, 0.0, 100.0, 0.0),
+            "repeater" => build::shape_repeater(&mut ids, 3.0, [100.0, 0.0]),
+            k => build::shape_simple_op(&mut ids, k).ok_or_else(|| bad("layer.addShapeItem", format!("unknown kind `{k}`")))?,
+        };
+        let uid = g.uid;
+        proj.next_id = next;
+        shape_item_target(proj, cid, lid, group_uid)?.children.push(g.into());
+        Ok(uid)
+    })?;
+    // The new item's property path, ready for prop.set / add_keyframe (`contents/trim#2/end`).
+    let path = s.project.comp(cid).and_then(|c| c.layer(lid)).and_then(|l| l.props.match_path_of(uid));
+    Ok(json!({"uid": uid, "path": path}))
+}
+
+/// The contents a new shape item goes into: the shape group `group_uid` (its Contents), else the
+/// layer's Contents.
+fn shape_item_target(proj: &mut Project, cid: ItemId, lid: LayerId, group_uid: Option<u64>) -> Result<&mut PropGroup> {
+    let l = layer_mut(proj, cid, lid)?;
+    let contents = l.props.sub_mut("contents").ok_or_else(|| bad("layer.addShapeItem", "not a shape layer"))?;
+    Ok(match group_uid {
+        Some(u) => contents
+            .find_group_mut(u)
+            .and_then(|g| if g.match_id == "contents" { Some(g) } else { g.sub_mut("contents") })
+            .ok_or_else(|| bad("layer.addShapeItem", "no such group"))?,
+        None => contents,
+    })
+}
+
+/// `layer.setText`: sets a text layer's Source Text and/or character attributes at the CTI.
+///
+/// A `font` name is also added to the recent fonts and the preferences saved. With an empty
+/// `range` and no `text`, while that layer is being edited and its document is non-empty,
+/// recognised character attributes are also staged in the pending insertion style without
+/// changing existing characters. Paragraph/document attributes still apply through the edit;
+/// the session is bumped whenever this branch runs. Document changes use [`Session::edit`],
+/// merged by `merge_p`. With `text` given, a layer whose name is empty or starts with `Text`
+/// takes the new first line (up to 40 characters) when that line is non-empty. Replies `null`.
+pub(super) fn set_text(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, lid) = layer_p(s, p, "layer.setText")?;
+    // The Character panel's recent fonts (Settings ▸ Type ▸ Number of Recent Fonts to Display).
+    if let Some(f) = str_p(p, "font") {
+        s.prefs.push_recent_font(f);
+        s.save_prefs();
+    }
+    let t = s.time();
+    let range = text_range_p(p);
+    // Character attributes with only a caret (no selected text) set the insertion style.
+    if let Some(r) = range.clone().filter(|r| r.is_empty() && str_p(p, "text").is_none())
+        && s.state.text_edit.as_ref().is_some_and(|e| e.layer == lid)
+        && let Some(doc) = crate::cmd::text_edit::layer_doc(s, lid)
+        && doc.char_len() > 0
+        && let Some(obj) = p.as_object()
+        && let Some(e) = s.state.text_edit.as_mut()
+    {
+        let mut st = e.pending.clone().unwrap_or_else(|| doc.insertion_style(r.start));
+        let mut any = false;
+        for (k, v) in obj {
+            any |= effectcraft_keyframe::text_doc::apply_char_attr(&mut st, k, v).map_err(|m| bad("layer.setText", m))?;
+        }
+        if any {
+            e.pending = Some(st);
+        }
+        s.bump();
+    }
+    // A changed Source Text is handled by `Session::edit`: its boundary clamps the selection and
+    // starts a new IME epoch only when the CTI document actually changed, so an identical text
+    // write stays a no-op and keeps the editor's owner.
+    s.edit("Edit Text", merge_p(p), |proj, _| {
+        let l = layer_mut(proj, cid, lid)?;
+        let lt = l.layer_time(t);
+        let pr = l.props.prop_mut("text/sourceText").ok_or_else(|| bad("layer.setText", "not a text layer"))?;
+        let mut doc = match pr.value_at(lt) {
+            KV::Text(d) => *d,
+            KV::Str(t) => TextDoc::plain(&t),
+            _ => TextDoc::default(),
+        };
+        apply_text_params("layer.setText", p, &mut doc, range.clone())?;
+        pr.set_value_at(lt, KV::Text(Box::new(doc.clone())));
+        if let Some(first) = doc.text.lines().next()
+            && str_p(p, "text").is_some()
+            && !first.is_empty()
+            && (l.name.starts_with("Text") || l.name.is_empty())
+        {
+            l.name = first.chars().take(40).collect();
+        }
+        Ok(())
+    })?;
+    Ok(Value::Null)
+}
diff --git a/crates/engine/src/cmd/layer/create.rs b/crates/engine/src/cmd/layer/create.rs
new file mode 100644
index 000000000..7962c2485
--- /dev/null
+++ b/crates/engine/src/cmd/layer/create.rs
@@ -0,0 +1,315 @@
+use super::{
+    EngineError, Ids, ItemId, ItemKind, Justify, KV, Label, Layer, LayerId, LayerSource, Project, Result, Session, Solid, TextDoc, Tick, Value, b_p, bad,
+    build, comp_id, f_p, json, limits, str_p,
+};
+
+pub(crate) fn color_p(p: &Value, k: &str) -> Option<[f32; 3]> {
+    match p.get(k)? {
+        Value::String(s) => effectcraft_color::Rgba::from_hex(s).map(|c| [c.r, c.g, c.b]),
+        Value::Array(a) => {
+            let g = |i: usize| a.get(i).and_then(Value::as_f64).unwrap_or(0.0) as f32;
+            Some([g(0), g(1), g(2)])
+        }
+        _ => None,
+    }
+}
+
+/// Insert a new layer above the selection (or at the top) and select it.
+pub(crate) fn insert_layer(proj: &mut Project, st: &mut crate::EditorState, cid: ItemId, layer: Layer) -> Result<LayerId> {
+    insert_layer_at(proj, st, cid, layer, None)
+}
+
+/// `index`: an `index` parameter, the layer's 1-based place in the stack (1 = top; past the
+/// bottom = the bottom), as 0-based.
+pub(crate) fn index_p(p: &Value, cmd: &str) -> Result<Option<usize>> {
+    match p.get("index") {
+        None | Some(Value::Null) => Ok(None),
+        Some(v) => {
+            v.as_u64().filter(|i| *i >= 1).map(|i| Some(usize::try_from(i - 1).unwrap_or(usize::MAX))).ok_or_else(|| bad(cmd, "index: 1-based stack position"))
+        }
+    }
+}
+
+/// A `position` parameter: `[x, y]` in comp pixels (finite).
+pub(crate) fn position_p(p: &Value, cmd: &str) -> Result<Option<[f64; 2]>> {
+    match p.get("position") {
+        None | Some(Value::Null) => Ok(None),
+        Some(v) => v
+            .as_array()
+            .and_then(|a| Some([a.first()?.as_f64()?, a.get(1)?.as_f64()?]))
+            .filter(|c| c.iter().all(|x| x.is_finite()))
+            .map(Some)
+            .ok_or_else(|| bad(cmd, "position: [x, y] in comp pixels")),
+    }
+}
+
+/// Put a new layer's Position at `pos` (comp pixels).
+pub(crate) fn place(l: &mut Layer, pos: Option<[f64; 2]>) {
+    if let Some([x, y]) = pos
+        && let Some(pr) = l.props.prop_mut("transform/position")
+    {
+        let z = match pr.value {
+            KV::Vec3(v) => v[2],
+            _ => 0.0,
+        };
+        pr.value = KV::Vec3([x, y, z]);
+    }
+}
+
+/// [`insert_layer`] at stack position `at` (0 = top) instead of above the selected layer.
+pub(crate) fn insert_layer_at(proj: &mut Project, st: &mut crate::EditorState, cid: ItemId, mut layer: Layer, at: Option<usize>) -> Result<LayerId> {
+    // Text and shape layers in Advanced 3D comps get Geometry Options (extrusion, bevels).
+    if proj.comp(cid).is_some_and(|c| c.renderer == effectcraft_project::Renderer::Advanced3D) {
+        crate::cmd::model3d::add_geometry_options(&mut proj.next_id, &mut layer);
+    }
+    let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+    let at = match at {
+        Some(i) => i.min(comp.layers.len()),
+        None => st.selected_layers.first().and_then(|id| comp.layers.iter().position(|l| l.id == *id)).unwrap_or(0),
+    };
+    let id = layer.id;
+    comp.layers.insert(at, layer);
+    st.selected_layers = vec![id];
+    st.selected_props.clear();
+    st.selected_keys.clear();
+    Ok(id)
+}
+
+fn solids_folder(proj: &mut Project) -> ItemId {
+    proj.folder_named("Solids").unwrap_or_else(|| proj.add_item("Solids", Label::Yellow, None, ItemKind::Folder))
+}
+
+fn new_solid_like(s: &mut Session, p: &Value, adjustment: bool) -> Result<Value> {
+    let cid = comp_id(s, p)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
+    let color = color_p(p, "color").unwrap_or(if adjustment { [1.0, 1.0, 1.0] } else { [0.85, 0.2, 0.2] });
+    // 1 to 30,000 px a side (#788): the layer is sized from the same numbers as its solid.
+    let w = p.get("width").and_then(Value::as_u64).map(limits::size).unwrap_or(comp.width);
+    let h = p.get("height").and_then(Value::as_u64).map(limits::size).unwrap_or(comp.height);
+    let pixel_aspect = pixel_aspect_p(p)?.unwrap_or(comp.pixel_aspect);
+    let default_name = if adjustment { "Adjustment Layer 1".to_string() } else { "Solid 1".to_string() };
+    let name = str_p(p, "name").map(str::to_string).unwrap_or(default_name);
+    let id = s.edit(if adjustment { "New Adjustment Layer" } else { "New Solid" }, None, |proj, st| {
+        let folder = solids_folder(proj);
+        let sid = proj.add_item(&name, Label::Red, Some(folder), ItemKind::Solid(Solid { color, width: w, height: h, pixel_aspect }));
+        let mut l = build::layer(proj, &comp, &name, LayerSource::Solid { item: sid }, (w, h), None);
+        if adjustment {
+            l.switches.adjustment = true;
+            l.label = Label::Purple;
+        }
+        insert_layer(proj, st, cid, l)
+    })?;
+    Ok(json!({"layer": id.0}))
+}
+
+/// `pixelAspect` (a positive number), when given.
+pub(super) fn pixel_aspect_p(p: &Value) -> Result<Option<f64>> {
+    match p.get("pixelAspect").and_then(Value::as_f64) {
+        Some(v) if !(v.is_finite() && v > 0.0) => Err(bad("layer.settings", "`pixelAspect` must be a positive number")),
+        v => Ok(v.map(limits::pixel_aspect)),
+    }
+}
+
+pub(super) fn new_solid(s: &mut Session, p: &Value) -> Result<Value> {
+    new_solid_like(s, p, false)
+}
+
+pub(super) fn new_adjustment(s: &mut Session, p: &Value) -> Result<Value> {
+    new_solid_like(s, p, true)
+}
+
+/// Parameters of `layer.setText` / `layer.newText` that aren't text attributes.
+const NOT_ATTRS: &[&str] = &["layer", "layers", "comp", "merge", "text", "range", "position", "edit"];
+
+/// Apply `layer.setText` keys to `d`: `text` replaces characters `r` (or everything), then each
+/// character / paragraph / document attribute applies to `r` (or everything).
+pub(super) fn apply_text_params(cmd: &str, p: &Value, d: &mut TextDoc, r: Option<std::ops::Range<usize>>) -> Result<()> {
+    let mut r = r;
+    if let Some(t) = str_p(p, "text") {
+        match r.clone() {
+            Some(rr) => {
+                d.replace_range(rr.clone(), t, None);
+                r = Some(rr.start..rr.start + t.chars().count());
+            }
+            None => d.set_text(t),
+        }
+    }
+    let Some(obj) = p.as_object() else { return Ok(()) };
+    for (k, v) in obj {
+        if NOT_ATTRS.contains(&k.as_str()) {
+            continue;
+        }
+        if !d.set_attr(k, v, r.clone()).map_err(|e| bad(cmd, e))? {
+            return Err(bad(cmd, format!("unknown text attribute {k}")));
+        }
+    }
+    Ok(())
+}
+
+pub(super) fn text_range_p(p: &Value) -> Option<std::ops::Range<usize>> {
+    let a = p.get("range")?.as_array()?;
+    let g = |i: usize| a.get(i).and_then(Value::as_u64).map(|x| x as usize);
+    let (x, y) = (g(0)?, g(1).or(g(0))?);
+    Some(x.min(y)..x.max(y))
+}
+
+/// `layer.newText`: adds a Text layer to the comp at the CTI and returns `{layer}`.
+///
+/// The document starts as centre-justified "Text", with the optional text parameters applied.
+/// With `box` `[x, y, w, h]`, `(x, y)` is the paragraph box's top-left in comp space. Its width
+/// and height are `w.abs().max(1.0)` and `h.abs().max(1.0)`; the layer position is the box centre.
+/// It is left justified unless `justify` is given. The layer is named by `name`, else the first 40
+/// characters of the first text line, else "Text". `edit: true` also opens a new editing
+/// session with anchor `0` and the caret after the text, selecting all initial text so the next
+/// insertion replaces it. The session has `created: true`, so leaving it empty removes the layer.
+pub(super) fn new_text(s: &mut Session, p: &Value) -> Result<Value> {
+    let cid = comp_id(s, p)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
+    let mut doc = TextDoc { text: "Text".into(), justify: Justify::Center, ..Default::default() };
+    // A paragraph box given in comp space: the layer sits at its centre.
+    let bx = p.get("box").and_then(Value::as_array).map(|a| [0, 1, 2, 3].map(|i| a.get(i).and_then(Value::as_f64).unwrap_or(0.0)));
+    let mut q = p.clone();
+    if let Some(o) = q.as_object_mut() {
+        o.remove("box");
+        o.remove("name");
+    }
+    let layer_name = str_p(p, "name").map(str::to_string);
+    apply_text_params("layer.newText", &q, &mut doc, None)?;
+    let mut pos = position_p(p, "layer.newText")?;
+    if let Some([x, y, w, h]) = bx {
+        let (w, h) = (w.abs().max(1.0), h.abs().max(1.0));
+        doc.box_size = Some([w, h]);
+        doc.box_pos = [-w / 2.0, -h / 2.0];
+        pos = Some([x + w / 2.0, y + h / 2.0]);
+        if p.get("justify").is_none() {
+            doc.set_attr("justify", &json!("left"), None).map_err(|e| bad("layer.newText", e))?;
+        }
+    }
+    let edit = b_p(p, "edit").unwrap_or(false);
+    let id = s.edit("New Text Layer", None, |proj, st| {
+        let name: String = layer_name.clone().unwrap_or_else(|| doc.text.lines().next().unwrap_or("").chars().take(40).collect());
+        let mut l = build::layer(proj, &comp, if name.is_empty() { "Text" } else { &name }, LayerSource::Text, (comp.width, comp.height), None);
+        if let Some(pr) = l.props.prop_mut("text/sourceText") {
+            pr.value = KV::Text(Box::new(doc.clone()));
+        }
+        if let Some(pos) = pos
+            && let Some(pr) = l.props.prop_mut("transform/position")
+        {
+            pr.value = KV::Vec3([pos[0], pos[1], 0.0]);
+        }
+        let n = doc.char_len();
+        let id = insert_layer(proj, st, cid, l)?;
+        if edit {
+            st.text_edit = Some(crate::cmd::text_edit::TextEdit {
+                layer: id,
+                anchor: 0,
+                caret: n,
+                created: true,
+                session: crate::cmd::text_edit::next_edit_session(),
+                ..Default::default()
+            });
+        }
+        Ok(id)
+    })?;
+    Ok(json!({"layer": id.0}))
+}
+
+pub(super) fn new_shape(s: &mut Session, p: &Value) -> Result<Value> {
+    let cid = comp_id(s, p)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
+    let kind = str_p(p, "kind").unwrap_or("none").to_string();
+    let size = p
+        .get("size")
+        .and_then(Value::as_array)
+        .map(|a| [a.first().and_then(Value::as_f64).unwrap_or(200.0), a.get(1).and_then(Value::as_f64).unwrap_or(200.0)])
+        .unwrap_or([300.0, 300.0]);
+    // A fill, and a stroke only with a width (not the Tools bar's paint).
+    let paint = crate::cmd::shape_tool::paint_p(p, &Default::default(), "layer.newShape")?;
+    let pos = p
+        .get("position")
+        .and_then(|v| v.as_array())
+        .map(|a| [a.first().and_then(Value::as_f64).unwrap_or(0.0), a.get(1).and_then(Value::as_f64).unwrap_or(0.0)]);
+    let name = str_p(p, "name").unwrap_or("Shape Layer 1").to_string();
+    let id = s.edit("New Shape Layer", None, |proj, st| {
+        let lid = crate::cmd::shape_tool::new_shape_layer(proj, st, &comp, cid, Some(&name), pos)?;
+        let mut next = proj.next_id;
+        let g = crate::cmd::shape_tool::shape_group(&mut Ids(&mut next), &kind, size, &paint);
+        proj.next_id = next;
+        if let Some(g) = g {
+            crate::cmd::shape_tool::add_to_contents(proj, cid, lid, g, [0.0, 0.0], "layer.newShape")?;
+        }
+        Ok(lid)
+    })?;
+    Ok(json!({"layer": id.0}))
+}
+
+fn new_simple(s: &mut Session, p: &Value, src: LayerSource, name: &str, label: &str) -> Result<Value> {
+    let cid = comp_id(s, p)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
+    let name = str_p(p, "name").unwrap_or(name).to_string();
+    let id = s.edit(label, None, |proj, st| {
+        let l = build::layer(proj, &comp, &name, src, (comp.width, comp.height), None);
+        insert_layer(proj, st, cid, l)
+    })?;
+    Ok(json!({"layer": id.0}))
+}
+
+pub(super) fn new_null(s: &mut Session, p: &Value) -> Result<Value> {
+    new_simple(s, p, LayerSource::Null, "Null 1", "New Null Object")
+}
+
+pub(super) fn add_item(s: &mut Session, p: &Value) -> Result<Value> {
+    let cid = comp_id(s, p)?;
+    let item = match p.get("item") {
+        Some(Value::Number(n)) => ItemId(n.as_u64().unwrap_or(0)),
+        Some(Value::String(name)) => s.project.find_by_name(name).map(|i| i.id).ok_or_else(|| bad("layer.addItem", format!("no item `{name}`")))?,
+        _ => *s.state.project_selection.first().ok_or_else(|| bad("layer.addItem", "missing `item`"))?,
+    };
+    if s.project.comp_contains(item, cid) {
+        return Err(bad("layer.addItem", "a composition can't contain itself"));
+    }
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
+    let it = s.project.item(item).ok_or_else(|| bad("layer.addItem", "no such item"))?.clone();
+    let (src, size, dur) = match &it.kind {
+        ItemKind::Comp(c) => (LayerSource::Comp { item }, (c.width, c.height), Some(c.duration)),
+        ItemKind::Footage(f) if f.kind == effectcraft_project::FootageKind::Still => {
+            // `duration`, else Settings ▸ Import ▸ Still Footage: length of the composition or a
+            // duration.
+            let d = f_p(p, "duration")
+                .filter(|d| d.is_finite() && *d > 0.0)
+                .or((s.prefs.import.still_footage == "seconds").then_some(s.prefs.import.still_seconds))
+                .map(Tick::from_seconds_f64);
+            (LayerSource::Footage { item }, (f.width, f.height), d)
+        }
+        ItemKind::Footage(f) if f.kind == effectcraft_project::FootageKind::Data => {
+            return Err(bad("layer.addItem", "data files can't be layers; read them in expressions with footage(\"name\").sourceData"));
+        }
+        ItemKind::Footage(f) if f.kind == effectcraft_project::FootageKind::Model => {
+            return crate::cmd::model3d::new_model(
+                s,
+                &serde_json::json!({"comp": cid.0, "item": item.0, "time": f_p(p, "time"), "index": p.get("index"), "position": p.get("position")}),
+            );
+        }
+        ItemKind::Footage(f) => (LayerSource::Footage { item }, (f.width, f.height), Some(f.looped_duration())),
+        ItemKind::Solid(so) => (LayerSource::Solid { item }, (so.width, so.height), None),
+        ItemKind::Folder => return Err(bad("layer.addItem", "folders can't be layers")),
+    };
+    let index = index_p(p, "layer.addItem")?;
+    let position = position_p(p, "layer.addItem")?;
+    let fr = comp.frame_rate;
+    // Settings ▸ General ▸ Create Layers at Composition Start Time (off: at the current time).
+    let default_start = if s.prefs.general.create_layers_at_comp_start || s.active_comp_id() != Some(cid) { Tick::ZERO } else { s.time() };
+    let start = fr.snap_nearest(f_p(p, "time").map(Tick::from_seconds_f64).unwrap_or(default_start));
+    let id = s.edit("Add Footage to Comp", None, |proj, st| {
+        let mut l = build::layer(proj, &comp, &it.name, src, size, dur);
+        l.start_time = start;
+        l.in_point = start;
+        // Footage and precomps keep their full length past the comp's end (After Effects); items
+        // without a duration (solids, comp-length stills) end with the comp.
+        let end = dur.map_or((start + comp.duration).min(comp.duration), |d| start + d);
+        l.out_point = fr.snap_nearest(end).max(start + fr.frame_duration());
+        place(&mut l, position);
+        insert_layer_at(proj, st, cid, l, index)
+    })?;
+    Ok(json!({"layer": id.0}))
+}
diff --git a/crates/engine/src/cmd/layer/parent.rs b/crates/engine/src/cmd/layer/parent.rs
new file mode 100644
index 000000000..fbaec14e4
--- /dev/null
+++ b/crates/engine/src/cmd/layer/parent.rs
@@ -0,0 +1,453 @@
+use super::{Comp, EngineError, ItemId, KV, Layer, LayerId, PropGroup, Result, Session, Tick, Value, b_p, bad, layers_p, resolve_layer};
+
+/// Re-express a layer in its new parent space without moving its anchor.
+pub(crate) struct ParentFix {
+    pub layer: LayerId,
+    /// Maps Position from the old parent's space into the new one's.
+    m: effectcraft_geom::Mat3,
+    /// Added to Rotation.
+    rotation: f64,
+    /// Multiply Scale.
+    scale: [f64; 2],
+    /// 3D AV layers retain their world-space anchor, including Z.
+    position_3d: Option<effectcraft_geom::Mat4>,
+    /// A uniform relative parent transform can preserve static Orientation and Scale.
+    pose_3d: Option<([f64; 3], f64)>,
+}
+
+impl ParentFix {
+    /// Re-express the layer's Position, Rotation and Scale (every key) in the new parent's space.
+    pub fn apply(&self, l: &mut Layer) {
+        let Some(tr) = l.props.sub_mut("transform") else { return };
+        if let Some(m) = self.position_3d {
+            // Spatial Position speed measures distance along its path. Its parent-space
+            // unit changes even when the child's Orientation cannot be re-expressed.
+            let position_speed = uniform_parent_pose(m, [0.0; 3]).map(|(_, factor)| factor.abs());
+            let map_position = |v: &KV| {
+                let q = m.apply(effectcraft_geom::Vec3::from(v.as_vec3()));
+                KV::Vec3([q.x, q.y, q.z])
+            };
+            // Read all separated axes before writing any of them.
+            let names = ["positionX", "positionY", "positionZ"];
+            if tr.get("positionX").is_some() {
+                let axes = names.map(|name| tr.get(name).cloned());
+                let current = axes.each_ref().map(|pr| pr.as_ref().map(|pr| pr.value.as_f64()).unwrap_or(0.0));
+                let q = m.apply(effectcraft_geom::Vec3::from(current));
+                for (i, name) in names.into_iter().enumerate() {
+                    if let Some(pr) = tr.get_mut(name) {
+                        pr.value = KV::Scalar([q.x, q.y, q.z].get(i).copied().unwrap_or(0.0));
+                        for key in &mut pr.keys {
+                            let p = axes.each_ref().map(|axis| axis.as_ref().map(|axis| axis.value_at(key.time).as_f64()).unwrap_or(0.0));
+                            let q = m.apply(effectcraft_geom::Vec3::from(p));
+                            key.value = KV::Scalar([q.x, q.y, q.z].get(i).copied().unwrap_or(0.0));
+                        }
+                    }
+                }
+            }
+            if let Some(pr) = tr.get_mut("position") {
+                pr.value = map_position(&pr.value);
+                for key in &mut pr.keys {
+                    key.value = map_position(&key.value);
+                    // Spatial tangents are vectors, so the parent's translation is excluded.
+                    for tangent in [&mut key.spatial_in, &mut key.spatial_out] {
+                        let v = m.apply_vec(effectcraft_geom::Vec3::from(*tangent));
+                        *tangent = [v.x, v.y, v.z];
+                    }
+                }
+                if let Some(factor) = position_speed
+                    .filter(|_| pr.spatial)
+                    .filter(|factor| pr.keys.iter().flat_map(|key| key.in_ease.iter().chain(&key.out_ease)).all(|ease| (ease.speed * *factor).is_finite()))
+                {
+                    for key in &mut pr.keys {
+                        for ease in key.in_ease.iter_mut().chain(&mut key.out_ease) {
+                            ease.speed *= factor;
+                        }
+                    }
+                }
+            }
+            // Cameras and lights aim with Point of Interest: move it by the same parent-space
+            // change, so a two-node rig keeps its world frame (#1010, #1020).
+            if let Some(pr) = tr.get_mut("poi") {
+                pr.value = map_position(&pr.value);
+                for key in &mut pr.keys {
+                    key.value = map_position(&key.value);
+                    for tangent in [&mut key.spatial_in, &mut key.spatial_out] {
+                        let v = m.apply_vec(effectcraft_geom::Vec3::from(*tangent));
+                        *tangent = [v.x, v.y, v.z];
+                    }
+                }
+                if let Some(factor) = position_speed
+                    .filter(|_| pr.spatial)
+                    .filter(|factor| pr.keys.iter().flat_map(|key| key.in_ease.iter().chain(&key.out_ease)).all(|ease| (ease.speed * *factor).is_finite()))
+                {
+                    for key in &mut pr.keys {
+                        for ease in key.in_ease.iter_mut().chain(&mut key.out_ease) {
+                            ease.speed *= factor;
+                        }
+                    }
+                }
+            }
+            if let Some((orientation, factor)) = self.pose_3d {
+                if let Some(pr) = tr.get_mut("orientation") {
+                    pr.value = KV::Vec3(orientation);
+                }
+                if let Some(pr) = tr.get_mut("scale") {
+                    let scaled = |value: &KV| KV::Vec3(value.as_vec3().map(|v| v * factor));
+                    pr.value = scaled(&pr.value);
+                    for key in &mut pr.keys {
+                        key.value = scaled(&key.value);
+                        // Scale's temporal speeds use the same units as its values.
+                        for ease in key.in_ease.iter_mut().chain(&mut key.out_ease) {
+                            ease.speed *= factor;
+                        }
+                    }
+                }
+            }
+            return;
+        }
+        let map = |pr: &mut effectcraft_project::Property, f: &dyn Fn(&KV) -> KV| {
+            pr.value = f(&pr.value);
+            for key in &mut pr.keys {
+                key.value = f(&key.value);
+            }
+        };
+        let m = self.m;
+        if tr.get("positionX").is_some() {
+            // Separated dimensions: X and Y move together, key by key at the same times.
+            // Everything is read before anything is written.
+            let [x, y] = [tr.get("positionX"), tr.get("positionY")].map(|p| p.map(|p| p.value.as_f64()).unwrap_or(0.0));
+            let q = m.apply(effectcraft_geom::vec2(x, y));
+            let keys_x: Vec<(Tick, f64)> = tr.get("positionX").map(|p| p.keys.iter().map(|k| (k.time, k.value.as_f64())).collect()).unwrap_or_default();
+            let keys_y: Vec<(Tick, f64)> = tr.get("positionY").map(|p| p.keys.iter().map(|k| (k.time, k.value.as_f64())).collect()).unwrap_or_default();
+            let at = |keys: &[(Tick, f64)], name: &str, t: Tick, tr: &PropGroup| {
+                keys.iter().find(|k| k.0 == t).map(|k| k.1).unwrap_or_else(|| tr.get(name).map(|p| p.value_at(t).as_f64()).unwrap_or(0.0))
+            };
+            let (xs, ys): (Vec<f64>, Vec<f64>) = (
+                keys_x.iter().map(|&(t, x)| m.apply(effectcraft_geom::vec2(x, at(&keys_y, "positionY", t, tr))).x).collect(),
+                keys_y.iter().map(|&(t, y)| m.apply(effectcraft_geom::vec2(at(&keys_x, "positionX", t, tr), y)).y).collect(),
+            );
+            for (name, value, vals) in [("positionX", q.x, xs), ("positionY", q.y, ys)] {
+                if let Some(pr) = tr.get_mut(name) {
+                    pr.value = KV::Scalar(value);
+                    for (k, v) in pr.keys.iter_mut().zip(vals) {
+                        k.value = KV::Scalar(v);
+                    }
+                }
+            }
+        } else if let Some(pr) = tr.get_mut("position") {
+            map(pr, &|v| {
+                let c = v.as_vec3();
+                let q = m.apply(effectcraft_geom::vec2(c[0], c[1]));
+                KV::Vec3([q.x, q.y, c[2]])
+            });
+        }
+        let (dr, k) = (self.rotation, self.scale);
+        if let Some(pr) = tr.get_mut("rotation") {
+            map(pr, &|v| KV::Scalar(v.as_f64() + dr));
+        }
+        if let Some(pr) = tr.get_mut("scale") {
+            map(pr, &|v| {
+                let c = v.as_vec3();
+                KV::Vec3([c[0] * k[0], c[1] * k[1], c[2]])
+            });
+        }
+    }
+}
+
+/// A uniform factor commutes with authored axis Rotation and Scale; prepend its orthogonal
+/// rotation to static Orientation using the existing Rz * Ry * Rx order.
+fn uniform_parent_pose(m: effectcraft_geom::Mat4, orientation: [f64; 3]) -> Option<([f64; 3], f64)> {
+    use effectcraft_geom::{Mat4, Vec3, vec3};
+    if !orientation.iter().all(|v| v.is_finite()) {
+        return None;
+    }
+    let a = m.0;
+    let columns = [vec3(a[0][0], a[1][0], a[2][0]), vec3(a[0][1], a[1][1], a[2][1]), vec3(a[0][2], a[1][2], a[2][2])];
+    let magnitude = columns[0].x.hypot(columns[0].y).hypot(columns[0].z);
+    if !magnitude.is_finite() || magnitude <= 0.0 {
+        return None;
+    }
+    let c = columns.map(|c| c / magnitude);
+    if c.iter().any(|c| (c.dot(*c) - 1.0).abs() > 1e-9) || c[0].dot(c[1]).abs() > 1e-9 || c[0].dot(c[2]).abs() > 1e-9 || c[1].dot(c[2]).abs() > 1e-9 {
+        return None;
+    }
+    let cross = vec3(c[1].y * c[2].z - c[1].z * c[2].y, c[1].z * c[2].x - c[1].x * c[2].z, c[1].x * c[2].y - c[1].y * c[2].x);
+    let factor = if c[0].dot(cross) < 0.0 { -magnitude } else { magnitude };
+    let mut rotation = Mat4::IDENTITY;
+    for row in 0..3 {
+        for col in 0..3 {
+            rotation.0[row][col] = a[row][col] / factor;
+        }
+    }
+    if (0..3).all(|row| (0..3).all(|col| (rotation.0[row][col] - if row == col { 1.0 } else { 0.0 }).abs() < 1e-12)) {
+        return Some((orientation, factor));
+    }
+    let r = (rotation * Mat4::orientation(Vec3::from(orientation))).0;
+    // atan2 rather than asin: near ±90 degrees asin loses precision, while cos(y) stays exact.
+    let cy = r[0][0].hypot(r[1][0]);
+    let y = (-r[2][0]).atan2(cy);
+    let (x, z) = if cy > 1e-9 { (r[2][1].atan2(r[2][2]), r[1][0].atan2(r[0][0])) } else { ((-r[1][2]).atan2(r[1][1]), 0.0) };
+    Some(([x.to_degrees(), y.to_degrees(), z.to_degrees()], factor))
+}
+
+/// A parent change retains 2D transforms and the world-space anchor of 3D layers (Position,
+/// and Point of Interest for two-node cameras and lights). Position is
+/// re-expressed in the new parent's space (`None`: the composition), evaluated at the current
+/// time.
+pub(crate) fn parent_fixes(s: &Session, cid: ItemId, ids: &[LayerId], parent: Option<LayerId>) -> Vec<ParentFix> {
+    let Some(comp) = s.project.comp(cid) else { return vec![] };
+    let ectx =
+        effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time: s.time(), expr: s.expr.as_deref(), footage: Some(s.footage.as_ref()) };
+    let space = |id: Option<LayerId>| -> effectcraft_geom::Mat3 {
+        id.and_then(|i| comp.layer(i)).filter(|l| !l.is_3d()).map(|l| ectx.layer_to_comp(l).0).unwrap_or(effectcraft_geom::Mat3::IDENTITY)
+    };
+    let decompose = |m: &effectcraft_geom::Mat3| {
+        let a = m.0;
+        let sx = (a[0][0] * a[0][0] + a[1][0] * a[1][0]).sqrt();
+        let det = a[0][0] * a[1][1] - a[0][1] * a[1][0];
+        (a[1][0].atan2(a[0][0]).to_degrees(), sx, if sx > 1e-12 { det / sx } else { 0.0 })
+    };
+    let new_m = space(parent);
+    let Some(inv) = new_m.inverse() else { return vec![] };
+    let (rn, sxn, syn) = decompose(&new_m);
+    let mut fixes: Vec<_> = comp
+        .layers
+        .iter()
+        .filter(|l| ids.contains(&l.id) && !l.is_3d() && l.parent != parent)
+        .map(|l| {
+            let old_m = space(l.parent);
+            let (ro, sxo, syo) = decompose(&old_m);
+            let scale = [if sxn.abs() > 1e-12 { sxo / sxn } else { 1.0 }, if syn.abs() > 1e-12 { syo / syn } else { 1.0 }];
+            ParentFix { layer: l.id, m: inv * old_m, rotation: ro - rn, scale, position_3d: None, pose_3d: None }
+        })
+        .collect();
+    let space_3d = |id: Option<LayerId>| {
+        id.and_then(|id| comp.layer(id)).map_or(effectcraft_geom::Mat4::IDENTITY, |layer| {
+            // Parent transforms do not inherit the parent's source pixel-aspect stretch.
+            let world = ectx.world_matrix(layer);
+            let par = ectx.par_ratio(layer);
+            let a = layer.transform().map(|tr| ectx.v3(layer, tr, "anchor", [0.0; 3])).unwrap_or([0.0; 3]);
+            let anchor = effectcraft_geom::vec3(a[0], a[1], if layer.is_3d() { a[2] } else { 0.0 });
+            world
+                * effectcraft_geom::Mat4::translate(anchor)
+                * effectcraft_geom::Mat4::scale(effectcraft_geom::vec3(1.0 / par, 1.0, 1.0))
+                * effectcraft_geom::Mat4::translate(-anchor)
+        })
+    };
+    if let Some(inv) = space_3d(parent).inverse().filter(|m| m.0.iter().flatten().all(|v| v.is_finite())) {
+        // Cameras and lights compensate like 3D layers (Position, and Point of Interest for
+        // two-node rigs), so parenting keeps the world frame (#1010, #1020). They have no
+        // Scale, so `pose_3d` below stays `None` and Orientation is kept as authored.
+        for layer in comp.layers.iter().filter(|l| ids.contains(&l.id) && l.is_3d() && l.parent != parent) {
+            let m = inv * space_3d(layer.parent);
+            if m.0.iter().flatten().all(|v| v.is_finite()) {
+                let pose_3d = layer.transform().and_then(|tr| {
+                    let orientation = tr.get("orientation")?;
+                    let scale = tr.get("scale")?;
+                    // Animated Euler Orientation and auto-orient cannot be re-expressed by
+                    // prepending a constant Euler value. Expression-driven values stay authored.
+                    if !orientation.keys.is_empty()
+                        || orientation.expr.is_some()
+                        || scale.expr.is_some()
+                        || layer.auto_orient != effectcraft_project::AutoOrient::Off
+                    {
+                        return None;
+                    }
+                    let pose = uniform_parent_pose(m, orientation.value.as_vec3())?;
+                    let factor = pose.1;
+                    let values_finite = std::iter::once(&scale.value)
+                        .chain(scale.keys.iter().map(|key| &key.value))
+                        .all(|value| value.as_vec3().iter().all(|v| (v * factor).is_finite()));
+                    let speeds_finite = scale.keys.iter().flat_map(|key| key.in_ease.iter().chain(&key.out_ease)).all(|ease| (ease.speed * factor).is_finite());
+                    (values_finite && speeds_finite).then_some(pose)
+                });
+                fixes.push(ParentFix { layer: layer.id, m: effectcraft_geom::Mat3::IDENTITY, rotation: 0.0, scale: [1.0; 2], position_3d: Some(m), pose_3d });
+            }
+        }
+    }
+    fixes
+}
+
+/// Validate the proposed ancestor chain before any authored edit, including when compensation
+/// is disabled. Bound both unique ancestors and linear lookup/selection work on loaded graphs.
+fn check_parent_chain(comp: &Comp, ids: &[LayerId], parent: Option<LayerId>, max_visits: usize, max_work: usize) -> Result<()> {
+    let mut seen = std::collections::HashSet::new();
+    let mut work = 0usize;
+    let mut cur = parent;
+    while let Some(id) = cur {
+        if seen.len() >= max_visits {
+            return Err(bad("layer.setParent", "parent chain exceeds the safety visit limit"));
+        }
+        if !seen.insert(id) {
+            return Err(bad("layer.setParent", "parent chain contains an existing cycle"));
+        }
+        for selected in ids {
+            if work >= max_work {
+                return Err(bad("layer.setParent", "parent chain exceeds the safety work limit"));
+            }
+            work += 1;
+            if *selected == id {
+                return Err(bad("layer.setParent", "parenting would create a cycle"));
+            }
+        }
+        let mut ancestor = None;
+        for layer in &comp.layers {
+            if work >= max_work {
+                return Err(bad("layer.setParent", "parent chain exceeds the safety work limit"));
+            }
+            work += 1;
+            if layer.id == id {
+                ancestor = Some(layer);
+                break;
+            }
+        }
+        let layer = ancestor.ok_or_else(|| bad("layer.setParent", "parent chain refers to a missing layer"))?;
+        cur = layer.parent;
+    }
+    Ok(())
+}
+
+pub(super) fn set_parent(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, ids) = layers_p(s, p)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let parent = match p.get("parent") {
+        None | Some(Value::Null) => None,
+        Some(v) => Some(resolve_layer(comp, v).ok_or_else(|| bad("layer.setParent", "no such parent layer"))?),
+    };
+    // A loaded cycle need not include a selected child. Validate before compensation or edit;
+    // do not impose the renderer's 64-ancestor truncation as a new ordinary hierarchy limit.
+    check_parent_chain(comp, &ids, parent, 4096, 1_048_576)?;
+    // Like AE's pick-whip, parenting keeps the layer where it is: its transform is re-expressed
+    // in the new parent's space (Position, Rotation, Scale), unless `compensate: false`.
+    let compensate = b_p(p, "compensate").unwrap_or(true);
+    let fixes = if compensate { parent_fixes(s, cid, &ids, parent) } else { vec![] };
+    s.edit("Parent", None, |proj, _| {
+        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+            l.parent = parent;
+            if let Some(f) = fixes.iter().find(|f| f.layer == l.id) {
+                f.apply(l);
+            }
+        }
+        Ok(())
+    })?;
+    Ok(Value::Null)
+}
+
+#[cfg(test)]
+mod parent_chain_tests {
+    use super::super::json;
+    use super::*;
+    use std::sync::Arc;
+
+    fn fixture() -> (Session, u64, u64, u64) {
+        let mut s = Session::default();
+        s.execute("comp.new", json!({"name":"Parent safety","width":16,"height":16,"duration":1})).unwrap();
+        let a = s.execute("layer.newSolid", json!({"name":"A"})).unwrap()["layer"].as_u64().unwrap();
+        let b = s.execute("layer.newSolid", json!({"name":"B"})).unwrap()["layer"].as_u64().unwrap();
+        let c = s.execute("layer.newSolid", json!({"name":"C"})).unwrap()["layer"].as_u64().unwrap();
+        for id in [a, b, c] {
+            s.execute("prop.set", json!({"layer":id,"path":"transform/anchor","value":[0,0,0]})).unwrap();
+        }
+        s.execute("prop.set", json!({"layer":a,"path":"transform/position","value":[100,200,0]})).unwrap();
+        s.execute("prop.set", json!({"layer":c,"path":"transform/position","value":[10,20,0]})).unwrap();
+        s.history.undo.clear();
+        (s, a, b, c)
+    }
+    fn malformed_parent(s: &mut Session, child: u64, parent: u64) {
+        let cid = s.active_comp_id().unwrap();
+        Arc::make_mut(&mut s.project).comp_mut(cid).unwrap().layer_mut(LayerId(child)).unwrap().parent = Some(LayerId(parent));
+    }
+    fn assert_atomic_error(s: &mut Session, child: u64, parent: u64, compensate: bool, message: &str) {
+        let before = s.project.clone();
+        let revision = s.revision;
+        let undo = s.history.undo.len();
+        let err = s.execute("layer.setParent", json!({"layers":[child],"parent":parent,"compensate":compensate})).unwrap_err();
+        assert!(err.to_string().contains(message), "{err}");
+        assert!(Arc::ptr_eq(&before, &s.project));
+        assert_eq!(s.revision, revision);
+        assert_eq!(s.history.undo.len(), undo);
+    }
+    #[test]
+    fn loaded_cycle_excluding_selected_child_is_rejected_atomically() {
+        for compensate in [true, false] {
+            let (mut s, a, b, c) = fixture();
+            // Simulate a malformed loaded project. Never execute this on the unguarded baseline.
+            malformed_parent(&mut s, a, b);
+            malformed_parent(&mut s, b, a);
+            assert_atomic_error(&mut s, c, a, compensate, "existing cycle");
+        }
+    }
+    #[test]
+    fn dangling_loaded_parent_is_rejected_atomically() {
+        for compensate in [true, false] {
+            let (mut s, a, _, c) = fixture();
+            malformed_parent(&mut s, a, u64::MAX);
+            assert_atomic_error(&mut s, c, a, compensate, "missing layer");
+        }
+    }
+    #[test]
+    fn selected_descendant_and_direct_self_are_rejected() {
+        let (mut s, a, _, c) = fixture();
+        assert_atomic_error(&mut s, c, c, false, "create a cycle");
+        s.execute("layer.setParent", json!({"layers":[a],"parent":c,"compensate":false})).unwrap();
+        assert_atomic_error(&mut s, c, a, true, "create a cycle");
+    }
+    #[test]
+    fn ordinary_parent_and_unparent_keep_explicit_false_and_undo_semantics() {
+        for compensate in [true, false] {
+            let (mut s, a, _, c) = fixture();
+            let old = s.project.clone();
+            let world = |s: &Session| {
+                let cid = s.active_comp_id().unwrap();
+                let comp = s.active_comp().unwrap();
+                let ctx = effectcraft_render::EvalCtx::new(&s.project, cid, comp, s.time());
+                ctx.world_matrix(comp.layer(LayerId(c)).unwrap()).apply(effectcraft_geom::Vec3::ZERO)
+            };
+            let before = world(&s);
+            s.execute("layer.setParent", json!({"layers":[c],"parent":a,"compensate":compensate})).unwrap();
+            let expected = if compensate { before } else { before + effectcraft_geom::vec3(100.0, 200.0, 0.0) };
+            assert!((world(&s) - expected).length() < 1e-9);
+            assert_eq!(s.active_comp().unwrap().layer(LayerId(c)).unwrap().parent, Some(LayerId(a)));
+            assert_eq!(s.history.undo.len(), 1);
+            let parented = s.project.clone();
+            assert!(s.undo());
+            assert!(Arc::ptr_eq(&s.project, &old));
+            assert!(s.redo());
+            assert!(Arc::ptr_eq(&s.project, &parented));
+            s.execute("layer.setParent", json!({"layers":[c],"parent":null,"compensate":compensate})).unwrap();
+            assert_eq!(s.active_comp().unwrap().layer(LayerId(c)).unwrap().parent, None);
+            assert!(s.undo());
+            assert!(Arc::ptr_eq(&s.project, &parented));
+        }
+    }
+    #[test]
+    fn ancestor_and_lookup_work_budgets_fail_closed() {
+        let (mut s, a, b, c) = fixture();
+        malformed_parent(&mut s, a, b);
+        let comp = s.active_comp().unwrap();
+        // New solids are inserted above the selection: C,B,A. Walking A->B scans
+        // three then two layers, and compares the one selected child twice: seven work units.
+        assert_eq!(comp.layers.iter().map(|l| l.id).collect::<Vec<_>>(), vec![LayerId(c), LayerId(b), LayerId(a)]);
+        assert!(check_parent_chain(comp, &[LayerId(c)], Some(LayerId(a)), 2, 7).is_ok());
+        assert!(check_parent_chain(comp, &[LayerId(c)], Some(LayerId(a)), 2, 6).unwrap_err().to_string().contains("work limit"));
+        assert!(check_parent_chain(comp, &[LayerId(c)], Some(LayerId(a)), 2, 256).is_ok());
+        assert!(check_parent_chain(comp, &[LayerId(c)], Some(LayerId(a)), 1, 256).unwrap_err().to_string().contains("visit limit"));
+        assert!(check_parent_chain(comp, &[LayerId(c)], Some(LayerId(a)), 2, 1).unwrap_err().to_string().contains("work limit"));
+        assert!(check_parent_chain(comp, &[LayerId(c)], None, 0, 0).is_ok(), "unparenting does not traverse ancestors");
+    }
+
+    #[test]
+    fn well_formed_chain_beyond_renderer_depth_is_not_unnecessarily_rejected() {
+        let (s, _, _, c) = fixture();
+        let mut comp = s.active_comp().unwrap().clone();
+        let template = comp.layers.first().unwrap().clone();
+        for n in 0..80 {
+            let mut layer = template.clone();
+            layer.id = LayerId(10_000 + n);
+            layer.parent = (n < 79).then_some(LayerId(10_001 + n));
+            comp.layers.push(layer);
+        }
+        assert!(check_parent_chain(&comp, &[LayerId(c)], Some(LayerId(10_000)), 4096, 1_048_576).is_ok());
+    }
+}
diff --git a/crates/engine/src/cmd/layer/replace.rs b/crates/engine/src/cmd/layer/replace.rs
new file mode 100644
index 000000000..80e5be807
--- /dev/null
+++ b/crates/engine/src/cmd/layer/replace.rs
@@ -0,0 +1,101 @@
+use super::{
+    EngineError, FootageKind, Ids, ItemId, ItemKind, Layer, LayerSource, Project, Result, Session, Value, bad, build, has_comp, json, layer_mut, layers_p,
+    unlocked,
+};
+
+/// A layer whose source is an item (footage, precomposition or solid), as in After Effects'
+/// Replace Source. Text, shape, null, camera, light and 3D model layers have no AVItem source to
+/// replace.
+fn replaceable_layer(l: &Layer) -> bool {
+    matches!(l.source, LayerSource::Footage { .. } | LayerSource::Comp { .. } | LayerSource::Solid { .. })
+}
+
+/// The source a Project item gives a layer, or why it can't replace one.
+fn replacement_source(item: ItemId, it: &effectcraft_project::Item) -> Result<LayerSource> {
+    const CMD: &str = "layer.replaceSource";
+    match &it.kind {
+        ItemKind::Comp(_) => Ok(LayerSource::Comp { item }),
+        ItemKind::Footage(f) if f.kind == FootageKind::Data => {
+            Err(bad(CMD, "data files can't be layer sources; read them in expressions with footage(\"name\").sourceData"))
+        }
+        ItemKind::Footage(f) if f.kind == FootageKind::Model => Err(bad(CMD, "3D model items can't replace a 2D layer source; add them as 3D layers")),
+        ItemKind::Footage(_) => Ok(LayerSource::Footage { item }),
+        ItemKind::Solid(_) => Ok(LayerSource::Solid { item }),
+        ItemKind::Folder => Err(bad(CMD, "folders can't be layer sources")),
+    }
+}
+
+/// Whether a source brings audio properties (precompositions always can; footage when it has an
+/// audio stream).
+fn source_has_audio(project: &Project, source: &LayerSource) -> bool {
+    match source {
+        LayerSource::Comp { .. } => true,
+        LayerSource::Footage { item } => project.item(*item).is_some_and(|i| matches!(&i.kind, ItemKind::Footage(f) if f.has_audio)),
+        _ => false,
+    }
+}
+
+pub(super) fn has_replace_source(s: &Session) -> std::result::Result<(), String> {
+    has_comp(s)?;
+    let c = s.active_comp().ok_or("no composition")?;
+    if !s.state.selected_layers.iter().filter_map(|l| c.layer(*l)).any(replaceable_layer) {
+        return Err("select a footage, composition or solid layer".into());
+    }
+    if s.state.project_selection.is_empty() {
+        return Err("select a footage item, a composition or a solid in the Project panel".into());
+    }
+    Ok(())
+}
+
+/// Replace the source of the selected (or `layers`) AV layers with a Project item, as After
+/// Effects' Alt-drag and Ctrl+Alt+/ do. The layer keeps every property: name, timing, transforms,
+/// keyframes, expressions, effects, masks, switches, parenting and track matte. Only its source
+/// changes; precompositions bring their Essential Properties group through `sync_project`, and a
+/// source with audio adds an Audio group when the layer has none.
+pub(super) fn replace_source(s: &mut Session, p: &Value) -> Result<Value> {
+    const CMD: &str = "layer.replaceSource";
+    let (cid, ids) = layers_p(s, p)?;
+    let ids = unlocked(s, cid, ids, CMD)?;
+    if ids.is_empty() {
+        return Err(bad(CMD, "select a layer first"));
+    }
+    let item = match p.get("item") {
+        Some(Value::Number(n)) => ItemId(n.as_u64().ok_or_else(|| bad(CMD, "item: a project item id"))?),
+        Some(Value::String(name)) => s.project.find_by_name(name).map(|i| i.id).ok_or_else(|| bad(CMD, format!("no item `{name}`")))?,
+        _ => *s.state.project_selection.first().ok_or_else(|| bad(CMD, "select a footage item, a composition or a solid in the Project panel"))?,
+    };
+    let it = s.project.item(item).ok_or_else(|| bad(CMD, format!("no item {}", item.0)))?;
+    let source = replacement_source(item, it)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    for lid in &ids {
+        let l = comp.layer(*lid).ok_or_else(|| bad(CMD, "no such layer"))?;
+        if !replaceable_layer(l) {
+            return Err(bad(CMD, format!("“{}” has no source item to replace", l.name)));
+        }
+    }
+    if let LayerSource::Comp { item: new } = &source
+        && s.project.comp_contains(*new, cid)
+    {
+        return Err(bad(CMD, "a composition can't contain itself"));
+    }
+    let has_audio = source_has_audio(&s.project, &source);
+    let source_for_edit = source.clone();
+    s.edit("Replace Layer Source", None, |proj, _| {
+        for lid in &ids {
+            let needs_audio = has_audio && proj.comp(cid).and_then(|c| c.layer(*lid)).is_some_and(|l| l.props.sub("audio").is_none());
+            let audio = if needs_audio {
+                let mut next = Ids(&mut proj.next_id);
+                Some(build::audio(&mut next))
+            } else {
+                None
+            };
+            let l = layer_mut(proj, cid, *lid)?;
+            l.source = source_for_edit.clone();
+            if let Some(audio) = audio {
+                l.props.children.push(audio.into());
+            }
+        }
+        Ok(())
+    })?;
+    Ok(json!({"layers": ids.iter().map(|l| l.0).collect::<Vec<_>>(), "item": item.0}))
+}
diff --git a/crates/engine/src/cmd/layer/select.rs b/crates/engine/src/cmd/layer/select.rs
new file mode 100644
index 000000000..0edf7a72c
--- /dev/null
+++ b/crates/engine/src/cmd/layer/select.rs
@@ -0,0 +1,73 @@
+use super::{EngineError, LayerId, Result, Session, Value, b_p, comp_id, json, resolve_layer};
+
+pub(super) fn select(s: &mut Session, p: &Value) -> Result<Value> {
+    let cid = comp_id(s, p)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let ids: Vec<LayerId> = match p.get("layers").or(p.get("layer")) {
+        Some(Value::Array(a)) => a.iter().filter_map(|v| resolve_layer(comp, v)).collect(),
+        Some(v) => resolve_layer(comp, v).into_iter().collect(),
+        None => vec![],
+    };
+    let add = b_p(p, "add").unwrap_or(false);
+    let toggle = b_p(p, "toggle").unwrap_or(false);
+    if toggle {
+        for id in ids {
+            if let Some(i) = s.state.selected_layers.iter().position(|l| *l == id) {
+                s.state.selected_layers.remove(i);
+            } else {
+                s.state.selected_layers.push(id);
+            }
+        }
+    } else if add {
+        for id in ids {
+            if !s.state.selected_layers.contains(&id) {
+                s.state.selected_layers.push(id);
+            }
+        }
+    } else {
+        s.state.selected_layers = ids;
+        s.state.selected_props.clear();
+        s.state.selected_keys.clear();
+        let keep = s.state.selected_layers.clone();
+        s.state.selected_vertices.retain(|v| keep.contains(&v.layer));
+    }
+    Ok(json!(s.state.selected_layers.iter().map(|l| l.0).collect::<Vec<_>>()))
+}
+
+pub(super) fn select_step(s: &mut Session, p: &Value, dir: i64) -> Result<Value> {
+    let comp = s.active_comp().ok_or(EngineError::NoComp)?;
+    if comp.layers.is_empty() {
+        return Ok(Value::Null);
+    }
+    let cur = s.state.selected_layers.first().and_then(|id| comp.layers.iter().position(|l| l.id == *id));
+    let n = comp.layers.len() as i64;
+    // The next layer that can be selected (locked and hidden shy layers are stepped over); at
+    // the end of the stack the selection stays.
+    let start = match cur {
+        Some(i) => i as i64 + dir,
+        None if dir > 0 => 0,
+        None => n - 1,
+    };
+    let next = std::iter::successors(Some(start), |i| Some(i + dir))
+        .take_while(|i| (0..n).contains(i))
+        .find(|i| crate::cmd::selectable(comp, &comp.layers[*i as usize]));
+    let Some(i) = next.or(cur.map(|i| i as i64)) else { return Ok(Value::Null) };
+    let id = comp.layers[i as usize].id;
+    let add = b_p(p, "add").unwrap_or(false);
+    if add {
+        if !s.state.selected_layers.contains(&id) {
+            s.state.selected_layers.insert(0, id);
+        }
+    } else {
+        s.state.selected_layers = vec![id];
+    }
+    Ok(json!(id.0))
+}
+
+pub(super) fn select_next(s: &mut Session, p: &Value) -> Result<Value> {
+    select_step(s, p, 1)
+}
+
+pub(super) fn select_prev(s: &mut Session, p: &Value) -> Result<Value> {
+    select_step(s, p, -1)
+}
diff --git a/crates/engine/src/cmd/layer/switches.rs b/crates/engine/src/cmd/layer/switches.rs
new file mode 100644
index 000000000..38689afbb
--- /dev/null
+++ b/crates/engine/src/cmd/layer/switches.rs
@@ -0,0 +1,213 @@
+use super::{
+    BlendMode, EngineError, FrameBlend, ItemId, KV, Layer, LayerId, MatteKind, Quality, Result, Session, TrackMatte, Value, b_p, bad, json, layer_mut, layer_p,
+    layers_p, merge_p, resolve_layer, str_p,
+};
+
+pub(super) fn set_switch(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, ids) = layers_p(s, p)?;
+    let name = str_p(p, "switch").ok_or_else(|| bad("layer.setSwitch", "missing `switch`"))?.to_string();
+    let v = b_p(p, "value");
+    let label = format!("Layer Switch ({name})");
+    if b_p(p, "others") == Some(true) {
+        return set_switch_others(s, cid, &ids, &name, v, &label);
+    }
+    // `merge`: a switch dragged over several layers in the Timeline is one undo step.
+    let r = s.edit(&label, merge_p(p), |proj, _| {
+        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        let mut last = false;
+        // Toggle relative to the first layer so a multi-selection ends up consistent.
+        let first = comp.layers.iter().find(|l| ids.contains(&l.id)).map(|l| switch_value(l, &name)).unwrap_or(Some(false));
+        let Some(first) = first else { return Err(bad("layer.setSwitch", format!("unknown switch `{name}`"))) };
+        let target = v.unwrap_or(!first);
+        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+            set_switch_value(l, &name, target);
+            last = target;
+        }
+        Ok(last)
+    })?;
+    Ok(json!(r))
+}
+
+/// `layer.setSwitch {others: true}` (Alt-click on an A/V feature in the Timeline): the named
+/// layers stand alone, shown / heard / soloed / unlocked while every other layer the switch
+/// applies to is the opposite; when they already do, the other layers come back. `value` sets
+/// the other layers directly.
+fn set_switch_others(s: &mut Session, cid: ItemId, ids: &[LayerId], name: &str, value: Option<bool>, label: &str) -> Result<Value> {
+    let r = s.edit(label, None, |proj, _| {
+        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        // The state that sets a layer apart: unlocked for Lock, on for the rest.
+        let active = !matches!(name, "lock" | "locked");
+        // Track mattes keep their video off by design.
+        let mattes: Vec<LayerId> =
+            if matches!(name, "video" | "eye") { comp.layers.iter().filter_map(|l| l.track_matte.map(|m| m.layer)).collect() } else { Vec::new() };
+        let applies = |l: &Layer| match name {
+            "audio" => l.props.sub("audio").is_some(),
+            "lock" | "locked" => true,
+            // Every layer has a Video switch (it hides a null's outline in the viewer and turns a
+            // camera or light off), as the Timeline's eye cell shows; track mattes keep theirs off
+            // by design.
+            "video" | "eye" => !mattes.contains(&l.id),
+            _ => l.source.is_av() && !mattes.contains(&l.id),
+        };
+        let mut alone = true;
+        for l in comp.layers.iter().filter(|l| applies(l)) {
+            let Some(on) = switch_value(l, name) else { return Err(bad("layer.setSwitch", format!("unknown switch `{name}`"))) };
+            alone &= on == (ids.contains(&l.id) == active);
+        }
+        let others = value.unwrap_or(alone == active);
+        for l in comp.layers.iter_mut().filter(|l| applies(l)) {
+            let v = if ids.contains(&l.id) { active } else { others };
+            set_switch_value(l, name, v);
+        }
+        Ok(others)
+    })?;
+    Ok(json!(r))
+}
+
+fn switch_value(l: &Layer, name: &str) -> Option<bool> {
+    let sw = &l.switches;
+    Some(match name {
+        "video" | "eye" => sw.video,
+        "audio" => sw.audio,
+        "solo" => sw.solo,
+        "lock" | "locked" => sw.locked,
+        "shy" => sw.shy,
+        "collapse" => sw.collapse,
+        "quality" => sw.quality == Quality::Best,
+        "fx" | "effects" => sw.effects,
+        "frameBlend" => sw.frame_blend != FrameBlend::Off,
+        "motionBlur" => sw.motion_blur,
+        "adjustment" => sw.adjustment,
+        "threeD" | "3d" | "3D" => sw.three_d,
+        "guide" => sw.guide,
+        "preserveTransparency" => l.preserve_transparency,
+        _ => return None,
+    })
+}
+
+fn set_switch_value(l: &mut Layer, name: &str, v: bool) {
+    let sw = &mut l.switches;
+    match name {
+        "video" | "eye" => sw.video = v,
+        "audio" => sw.audio = v,
+        "solo" => sw.solo = v,
+        "lock" | "locked" => sw.locked = v,
+        "shy" => sw.shy = v,
+        "collapse" => sw.collapse = v,
+        "quality" => sw.quality = if v { Quality::Best } else { Quality::Draft },
+        "fx" | "effects" => sw.effects = v,
+        "frameBlend" => sw.frame_blend = if v { FrameBlend::FrameMix } else { FrameBlend::Off },
+        "motionBlur" => sw.motion_blur = v,
+        "adjustment" => sw.adjustment = v,
+        "threeD" | "3d" | "3D" => {
+            if sw.three_d && !v {
+                drop_3d_values(l);
+            }
+            l.switches.three_d = v;
+        }
+        "guide" => sw.guide = v,
+        "preserveTransparency" => l.preserve_transparency = v,
+        _ => {}
+    }
+}
+
+/// Turning the 3D switch off discards Z values, Orientation and X/Y Rotation (as in AE).
+fn drop_3d_values(l: &mut Layer) {
+    let Some(tr) = l.transform_mut() else { return };
+    for (m, keep) in [("position", 0.0), ("anchor", 0.0), ("scale", 100.0)] {
+        if let Some(pr) = tr.get_mut(m) {
+            let flat = |v: &mut KV| {
+                if let KV::Vec3(a) = v {
+                    a[2] = keep;
+                }
+            };
+            flat(&mut pr.value);
+            for k in &mut pr.keys {
+                flat(&mut k.value);
+            }
+        }
+    }
+    for (m, zero) in [("orientation", KV::Vec3([0.0; 3])), ("rotationX", KV::Scalar(0.0)), ("rotationY", KV::Scalar(0.0))] {
+        if let Some(pr) = tr.get_mut(m) {
+            pr.keys.clear();
+            pr.expr = None;
+            pr.value = zero;
+        }
+    }
+}
+
+pub(super) fn rename(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, lid) = layer_p(s, p, "layer.rename")?;
+    let name = str_p(p, "name").ok_or_else(|| bad("layer.rename", "missing `name`"))?.to_string();
+    s.edit("Rename Layer", None, |proj, _| {
+        layer_mut(proj, cid, lid)?.name = name.clone();
+        Ok(())
+    })?;
+    Ok(Value::Null)
+}
+
+/// The Timeline's Comment column.
+pub(super) fn set_comment(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, ids) = layers_p(s, p)?;
+    let text = str_p(p, "comment").ok_or_else(|| bad("layer.setComment", "missing `comment`"))?.to_string();
+    s.edit("Layer Comment", None, |proj, _| {
+        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+            l.comment = text.clone();
+        }
+        Ok(())
+    })?;
+    Ok(Value::Null)
+}
+
+pub(super) fn blend(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, ids) = layers_p(s, p)?;
+    let mode = str_p(p, "mode").and_then(BlendMode::from_name);
+    let step = p.get("step").and_then(Value::as_i64).unwrap_or(0);
+    if mode.is_none() && step == 0 {
+        return Err(bad("layer.setBlendMode", "need `mode` (e.g. Multiply) or `step` ±1"));
+    }
+    s.edit("Blending Mode", None, |proj, _| {
+        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+            l.blend_mode = match mode {
+                Some(m) => m,
+                None if step > 0 => l.blend_mode.next(),
+                None => l.blend_mode.previous(),
+            };
+        }
+        Ok(())
+    })?;
+    Ok(Value::Null)
+}
+
+pub(super) fn track_matte(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, lid) = layer_p(s, p, "layer.setTrackMatte")?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let matte = match p.get("matte") {
+        None | Some(Value::Null) => None,
+        Some(v) => Some(resolve_layer(comp, v).ok_or_else(|| bad("layer.setTrackMatte", "no such matte layer"))?),
+    };
+    let kind = str_p(p, "kind")
+        .map(|k| match k.to_ascii_lowercase().replace([' ', '_', '-'], "").as_str() {
+            "alphainverted" | "alphainv" => MatteKind::AlphaInverted,
+            "luma" => MatteKind::Luma,
+            "lumainverted" | "lumainv" => MatteKind::LumaInverted,
+            _ => MatteKind::Alpha,
+        })
+        .unwrap_or(MatteKind::Alpha);
+    s.edit("Track Matte", None, |proj, _| {
+        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        if let Some(m) = matte {
+            if m == lid {
+                return Err(bad("layer.setTrackMatte", "a layer can't be its own matte"));
+            }
+            if let Some(ml) = comp.layer_mut(m) {
+                ml.switches.video = false;
+            }
+        }
+        comp.layer_mut(lid).ok_or(EngineError::NoComp)?.track_matte = matte.map(|layer| TrackMatte { layer, kind });
+        Ok(())
+    })?;
+    Ok(Value::Null)
+}
diff --git a/crates/engine/src/cmd/layer/timing.rs b/crates/engine/src/cmd/layer/timing.rs
new file mode 100644
index 000000000..711eefee2
--- /dev/null
+++ b/crates/engine/src/cmd/layer/timing.rs
@@ -0,0 +1,286 @@
+use super::{
+    EngineError, ItemKind, Label, Layer, LayerId, LayerSource, Result, Session, Tick, Value, b_p, bad, build, f_p, json, layer_mut, layers_p, merge_p,
+    resolve_layer, str_p, unlocked, with,
+};
+
+pub(super) fn timing(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, ids) = layers_p(s, p)?;
+    let t = s.time();
+    let op = str_p(p, "op").unwrap_or("set").to_string();
+    // Layer times stay on frame boundaries of the comp (as in AE).
+    let fr = s.project.comp(cid).ok_or(EngineError::NoComp)?.frame_rate;
+    let snap = |k: &str| f_p(p, k).map(|v| fr.snap_nearest(Tick::from_seconds_f64(v)));
+    let (delta, start, inp, outp) = (snap("delta"), snap("start"), snap("in"), snap("out"));
+    // Relative trims: each layer moves its own in/out point by the same amount, so dragging an
+    // edge of several selected layers trims them all together (as in AE).
+    let (in_delta, out_delta) = (snap("inDelta"), snap("outDelta"));
+    s.edit("Layer Timing", merge_p(p), |proj, _| {
+        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        let fd = comp.frame_duration();
+        let comp_dur = comp.duration;
+        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+            let shift = |l: &mut Layer, d: Tick| {
+                l.start_time += d;
+                l.in_point += d;
+                l.out_point += d;
+            };
+            match op.as_str() {
+                "moveInToTime" => {
+                    let d = t - l.in_point;
+                    shift(l, d);
+                }
+                "moveOutToTime" => {
+                    let d = t - l.out_point;
+                    shift(l, d);
+                }
+                "moveInToStart" => {
+                    let d = Tick::ZERO - l.in_point;
+                    shift(l, d);
+                }
+                "moveOutToEnd" => {
+                    let d = comp_dur - l.out_point;
+                    shift(l, d);
+                }
+                "trimInToTime" => l.in_point = t.min(l.out_point - fd),
+                "trimOutToTime" => l.out_point = t.max(l.in_point + fd),
+                _ => {
+                    if let Some(d) = delta {
+                        shift(l, d);
+                    }
+                    if let Some(st) = start {
+                        let d = st - l.start_time;
+                        shift(l, d);
+                    }
+                    if let Some(i) = inp {
+                        l.in_point = i.min(l.out_point - fd);
+                    }
+                    if let Some(o) = outp {
+                        l.out_point = o.max(l.in_point + fd);
+                    }
+                    // Stops at the comp start/end (a point already past it doesn't jump onto
+                    // it), keeping at least one frame of layer.
+                    if let Some(d) = in_delta {
+                        l.in_point = (l.in_point + d).max(Tick::ZERO.min(l.in_point)).min(l.out_point - fd);
+                    }
+                    if let Some(d) = out_delta {
+                        l.out_point = (l.out_point + d).min(comp_dur.max(l.out_point)).max(l.in_point + fd);
+                    }
+                }
+            }
+        }
+        Ok(())
+    })?;
+    Ok(Value::Null)
+}
+
+/// Move the layers `frames` frames in time (Alt+Page Up / Page Down, with Shift ten frames).
+pub(super) fn move_frames(s: &mut Session, p: &Value, frames: i64) -> Result<Value> {
+    let (cid, _) = layers_p(s, p)?;
+    let delta = s.project.comp(cid).ok_or(EngineError::NoComp)?.frame_rate.tick_of(frames).seconds();
+    timing(s, &with(p, "delta", json!(delta)))
+}
+
+/// Slip edit: move a layer's source (footage or precomp) under its fixed in and out points, like
+/// dragging the source-duration bar in After Effects. `delta` in seconds or `frames`; positive
+/// moves the source later. Clamped so the source still covers the in–out span. Keyframes and
+/// layer markers are in layer time, so they travel with the source.
+pub(super) fn slip(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, ids) = layers_p(s, p)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let fr = comp.frame_rate;
+    let delta = match (p.get("frames").and_then(Value::as_i64), f_p(p, "delta")) {
+        (Some(f), _) => fr.tick_of(f),
+        (None, Some(d)) => fr.snap_nearest(Tick::from_seconds_f64(d)),
+        _ => return Err(bad("layer.slip", "delta (seconds) or frames required")),
+    };
+    // Allowed shift per layer: the source span [lo, hi] in comp time must keep covering in..out.
+    let mut shifts: Vec<(LayerId, Tick)> = Vec::new();
+    for l in comp.layers.iter().filter(|l| ids.contains(&l.id)) {
+        if l.props.get("timeRemap").is_some() {
+            continue;
+        }
+        let dur = match &l.source {
+            LayerSource::Footage { item } => match s.project.item(*item).map(|i| &i.kind) {
+                Some(ItemKind::Footage(f)) if f.kind != effectcraft_project::FootageKind::Still => Some(f.looped_duration()),
+                _ => None,
+            },
+            LayerSource::Comp { item } => s.project.comp(*item).map(|c| c.duration),
+            _ => None,
+        };
+        let Some(dur) = dur else { continue };
+        let (a, b) = (l.comp_time(Tick::ZERO), l.comp_time(dur));
+        let (lo, hi) = (a.min(b), a.max(b));
+        let (min_d, max_d) = (l.out_point - hi, l.in_point - lo);
+        if min_d > max_d {
+            continue;
+        }
+        shifts.push((l.id, delta.max(min_d).min(max_d)));
+    }
+    if shifts.is_empty() {
+        return Err(bad("layer.slip", "select a footage or precomp layer (without time remapping)"));
+    }
+    s.edit("Slip Edit", merge_p(p), |proj, _| {
+        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        for (id, d) in &shifts {
+            if let Some(l) = comp.layer_mut(*id) {
+                l.start_time += *d;
+            }
+        }
+        Ok(())
+    })?;
+    Ok(json!({"slipped": shifts.iter().map(|(id, d)| json!({"layer": id.0, "delta": d.seconds()})).collect::<Vec<_>>()}))
+}
+
+pub(super) fn arrange(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, ids) = layers_p(s, p)?;
+    let ids = unlocked(s, cid, ids, "layer.arrange")?;
+    let how = str_p(p, "to").unwrap_or("front").to_string();
+    let index = p.get("index").and_then(Value::as_u64).map(|i| i as usize);
+    // `above`: put the layers right above that one (the timeline's drag to reorder).
+    let above = match p.get("above") {
+        Some(v) => {
+            let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+            let a = resolve_layer(comp, v).ok_or_else(|| bad("layer.arrange", "no such layer for `above`"))?;
+            if ids.contains(&a) {
+                return Err(bad("layer.arrange", "`above` must be a layer that isn't being moved"));
+            }
+            Some(a)
+        }
+        None => None,
+    };
+    s.edit("Arrange Layers", None, |proj, _| {
+        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        // Bring Forward / Send Backward move each layer one step past the next layer that isn't
+        // moving (a run of selected layers moves as one; one already at the end stays).
+        if above.is_none() && index.is_none() && matches!(how.as_str(), "forward" | "backward") {
+            let picked = |l: &Layer| ids.contains(&l.id);
+            let n = comp.layers.len();
+            if how == "forward" {
+                for i in 1..n {
+                    if picked(&comp.layers[i]) && !picked(&comp.layers[i - 1]) {
+                        let run_end = (i..n).find(|j| !picked(&comp.layers[*j])).unwrap_or(n);
+                        comp.layers[i - 1..run_end].rotate_left(1);
+                    }
+                }
+            } else {
+                for i in (0..n.saturating_sub(1)).rev() {
+                    if picked(&comp.layers[i]) && !picked(&comp.layers[i + 1]) {
+                        let run_start = (0..=i).rev().find(|j| !picked(&comp.layers[*j])).map_or(0, |j| j + 1);
+                        comp.layers[run_start..=i + 1].rotate_right(1);
+                    }
+                }
+            }
+            return Ok(());
+        }
+        let mut picked: Vec<Layer> = Vec::new();
+        comp.layers.retain(|l| {
+            if ids.contains(&l.id) {
+                picked.push(l.clone());
+                false
+            } else {
+                true
+            }
+        });
+        let at = match (how.as_str(), index) {
+            _ if above.is_some() => comp.layers.iter().position(|l| Some(l.id) == above).unwrap_or(comp.layers.len()),
+            (_, Some(i)) => i.saturating_sub(1).min(comp.layers.len()),
+            ("back", _) => comp.layers.len(),
+            _ => 0,
+        };
+        for (k, l) in picked.into_iter().enumerate() {
+            comp.layers.insert((at + k).min(comp.layers.len()), l);
+        }
+        Ok(())
+    })?;
+    Ok(Value::Null)
+}
+
+/// Layer ▸ Pre-compose. `mode: move` (default; "Move all attributes into the new composition")
+/// nests the selected layers as they are; `mode: leave` ("Leave all attributes in", one footage,
+/// solid or precomp layer) nests only the layer's source, sized to it, and keeps the layer's
+/// transform, masks, effects and timing in the current comp. `adjustDuration` (move) trims the
+/// new comp to the selected layers' span; `open` opens the new comp.
+pub(super) fn precompose(s: &mut Session, p: &Value) -> Result<Value> {
+    let c = "layer.precompose";
+    let (cid, ids) = layers_p(s, p)?;
+    if ids.is_empty() {
+        return Err(bad(c, "no layers"));
+    }
+    let name = str_p(p, "name").unwrap_or("Pre-comp 1").to_string();
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
+    let leave = match str_p(p, "mode").unwrap_or("move") {
+        "move" => false,
+        "leave" => true,
+        x => return Err(bad(c, format!("mode: move|leave, got `{x}`"))),
+    };
+    let adjust = b_p(p, "adjustDuration").unwrap_or(false);
+    if leave {
+        let [lid] = ids[..] else { return Err(bad(c, "\"Leave all attributes\" needs exactly one layer")) };
+        let layer = comp.layer(lid).ok_or(EngineError::NoComp)?.clone();
+        let Some(src_item) = layer.source.item() else {
+            return Err(bad(c, "\"Leave all attributes\" is available for footage, solid and precomp layers only"));
+        };
+        let (w, h) = effectcraft_render::source_size(&s.project, &layer);
+        let (w, h) = if w == 0 || h == 0 { (comp.width, comp.height) } else { (w, h) };
+        let dur = match s.project.item(src_item).map(|i| &i.kind) {
+            Some(ItemKind::Comp(nc)) => nc.duration,
+            Some(ItemKind::Footage(f)) if f.duration > Tick(0) => f.duration,
+            _ => comp.duration,
+        };
+        let new = s.edit("Pre-compose", None, |proj, st| {
+            let mut inner = comp.nested_like(w, h, dur);
+            let mut il = build::layer(proj, &inner, &layer.name, layer.source.clone(), (w, h), Some(dur));
+            il.name = layer.name.clone();
+            inner.layers.push(il);
+            let iid = proj.add_item(&name, Label::Sandstone, None, ItemKind::Comp(inner.into()));
+            let l = layer_mut(proj, cid, lid)?;
+            l.source = LayerSource::Comp { item: iid };
+            l.name = name.clone();
+            st.selected_layers = vec![lid];
+            Ok((iid, lid))
+        })?;
+        if b_p(p, "open").unwrap_or(false) {
+            s.open_comp(new.0);
+        }
+        return Ok(json!({"comp": new.0.0, "layer": new.1.0}));
+    }
+    let span = {
+        let sel: Vec<&effectcraft_project::Layer> = comp.layers.iter().filter(|l| ids.contains(&l.id)).collect();
+        let a = sel.iter().map(|l| l.in_point).min().unwrap_or(Tick(0)).max(Tick(0));
+        let b = sel.iter().map(|l| l.out_point).max().unwrap_or(comp.duration).min(comp.duration);
+        (a, b)
+    };
+    let (offset, dur) = if adjust && span.1 > span.0 { (span.0, span.1 - span.0) } else { (Tick(0), comp.duration) };
+    let new = s.edit("Pre-compose", None, |proj, st| {
+        let mut inner = comp.nested_like(comp.width, comp.height, dur);
+        inner.layers = comp.layers.iter().filter(|l| ids.contains(&l.id)).cloned().collect();
+        for l in &mut inner.layers {
+            if l.parent.is_some_and(|p| !ids.contains(&p)) {
+                l.parent = None;
+            }
+            if l.track_matte.is_some_and(|m| !ids.contains(&m.layer)) {
+                l.track_matte = None;
+            }
+            l.start_time -= offset;
+            l.in_point -= offset;
+            l.out_point -= offset;
+        }
+        let iid = proj.add_item(&name, Label::Sandstone, None, ItemKind::Comp(inner.into()));
+        let mut l = build::layer(proj, &comp, &name, LayerSource::Comp { item: iid }, (comp.width, comp.height), Some(dur));
+        l.name = name.clone();
+        l.start_time = offset;
+        l.in_point = offset;
+        l.out_point = offset + dur;
+        let c = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        let at = c.layers.iter().position(|l| ids.contains(&l.id)).unwrap_or(0);
+        c.layers.retain(|l| !ids.contains(&l.id));
+        let lid = l.id;
+        c.layers.insert(at.min(c.layers.len()), l);
+        st.selected_layers = vec![lid];
+        Ok((iid, lid))
+    })?;
+    if b_p(p, "open").unwrap_or(false) {
+        s.open_comp(new.0);
+    }
+    Ok(json!({"comp": new.0.0, "layer": new.1.0}))
+}
diff --git a/crates/engine/src/cmd/layer/transform.rs b/crates/engine/src/cmd/layer/transform.rs
new file mode 100644
index 000000000..8b75dcbc8
--- /dev/null
+++ b/crates/engine/src/cmd/layer/transform.rs
@@ -0,0 +1,194 @@
+use super::create::{color_p, pixel_aspect_p};
+use super::{
+    EngineError, ItemKind, KV, LayerId, LayerSource, PropGroup, Result, Session, Tick, Value, bad, has_layers, json, layer_mut, layer_p, layers_p, limits,
+    str_p, unlocked,
+};
+
+/// Move Position by `(dx, dy)`, including every key. Separated dimensions move X and Y as well
+/// as the combined property the channels were split from.
+pub(crate) fn offset_position(tr: &mut PropGroup, dx: f64, dy: f64) {
+    if dx == 0.0 && dy == 0.0 {
+        return;
+    }
+    if tr.get("positionX").is_some() {
+        for (name, d) in [("positionX", dx), ("positionY", dy)] {
+            if let Some(pr) = tr.get_mut(name) {
+                pr.value = KV::Scalar(pr.value.as_f64() + d);
+                for k in &mut pr.keys {
+                    k.value = KV::Scalar(k.value.as_f64() + d);
+                }
+            }
+        }
+    }
+    if let Some(pr) = tr.get_mut("position") {
+        let shift = |v: &KV| match v {
+            KV::Vec2(a) => KV::Vec2([a[0] + dx, a[1] + dy]),
+            other => {
+                let a = other.as_vec3();
+                KV::Vec3([a[0] + dx, a[1] + dy, a[2]])
+            }
+        };
+        pr.value = shift(&pr.value);
+        for k in &mut pr.keys {
+            k.value = shift(&k.value);
+        }
+    }
+}
+
+/// Set a layer's Position at layer time `lt` to `f(current)`: X/Y/Z Position when its dimensions
+/// are separated.
+pub(crate) fn update_position(tr: &mut PropGroup, lt: Tick, f: impl Fn([f64; 3]) -> [f64; 3]) {
+    const SEPARATE: [&str; 3] = ["positionX", "positionY", "positionZ"];
+    if tr.get("positionX").is_some() {
+        let v = f(SEPARATE.map(|m| tr.get(m).map(|p| p.value_at(lt).as_f64()).unwrap_or(0.0)));
+        for (m, x) in SEPARATE.iter().zip(v) {
+            if let Some(pr) = tr.get_mut(m) {
+                pr.set_value_at(lt, KV::Scalar(x));
+            }
+        }
+    } else if let Some(pr) = tr.get_mut("position") {
+        let v = f(pr.value_at(lt).as_vec3());
+        pr.set_value_at(lt, KV::Vec3(v));
+    }
+}
+
+/// A Transform property's default (Reset) by match id: the anchor at the centre of the source
+/// (`w`×`h`), the position at the comp's (`cw`×`ch`), 100% scale and opacity, no rotation.
+pub(crate) fn transform_default(m: &str, (w, h): (f64, f64), (cw, ch): (f64, f64)) -> Option<KV> {
+    Some(match m {
+        "anchor" => KV::Vec3([w / 2.0, h / 2.0, 0.0]),
+        "position" => KV::Vec3([cw / 2.0, ch / 2.0, 0.0]),
+        "positionX" => KV::Scalar(cw / 2.0),
+        "positionY" => KV::Scalar(ch / 2.0),
+        "positionZ" | "rotation" | "rotationX" | "rotationY" => KV::Scalar(0.0),
+        "scale" => KV::Vec3([100.0; 3]),
+        "orientation" => KV::Vec3([0.0; 3]),
+        "opacity" => KV::Scalar(100.0),
+        _ => return None,
+    })
+}
+
+pub(super) fn transform_op(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, ids) = layers_p(s, p)?;
+    let ids = unlocked(s, cid, ids, "layer.transform")?;
+    let op = str_p(p, "op").unwrap_or("reset").to_string();
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
+    let t = s.time();
+    let sizes: Vec<(LayerId, (u32, u32))> =
+        comp.layers.iter().filter(|l| ids.contains(&l.id)).map(|l| (l.id, effectcraft_render::source_size(&s.project, l))).collect();
+    s.edit("Transform", None, |proj, _| {
+        for (lid, (w, h)) in &sizes {
+            let l = layer_mut(proj, cid, *lid)?;
+            let lt = l.layer_time(t);
+            let (cw, ch) = (comp.width as f64, comp.height as f64);
+            let (w, h) = (*w as f64, *h as f64);
+            let Some(tr) = l.transform_mut() else { continue };
+            let set = |tr: &mut PropGroup, m: &str, v: KV| {
+                if let Some(pr) = tr.get_mut(m) {
+                    pr.set_value_at(lt, v);
+                }
+            };
+            match op.as_str() {
+                "reset" => {
+                    for m in ["anchor", "scale", "rotation", "rotationX", "rotationY", "orientation", "opacity"] {
+                        if let Some(v) = transform_default(m, (w, h), (cw, ch)) {
+                            set(tr, m, v);
+                        }
+                    }
+                    update_position(tr, lt, |_| [cw / 2.0, ch / 2.0, 0.0]);
+                }
+                // Centred in the frame; a 3D layer keeps its depth.
+                "center" => update_position(tr, lt, |p| [cw / 2.0, ch / 2.0, p[2]]),
+                "fit" | "fitWidth" | "fitHeight" if w > 0.0 && h > 0.0 => {
+                    let (sx, sy) = match op.as_str() {
+                        "fitWidth" => (cw / w, cw / w),
+                        "fitHeight" => (ch / h, ch / h),
+                        _ => (cw / w, ch / h),
+                    };
+                    let z = |m: &str, d: f64| tr.get(m).map(|p| p.value_at(lt).as_vec3()[2]).unwrap_or(d);
+                    let (sz, az) = (z("scale", 100.0), z("anchor", 0.0));
+                    set(tr, "scale", KV::Vec3([sx * 100.0, sy * 100.0, sz]));
+                    update_position(tr, lt, |p| [cw / 2.0, ch / 2.0, p[2]]);
+                    set(tr, "anchor", KV::Vec3([w / 2.0, h / 2.0, az]));
+                }
+                "flipH" | "flipV" => {
+                    let cur = tr.get("scale").map(|p| p.value_at(lt).as_vec3()).unwrap_or([100.0; 3]);
+                    let v = if op == "flipH" { [-cur[0], cur[1], cur[2]] } else { [cur[0], -cur[1], cur[2]] };
+                    set(tr, "scale", KV::Vec3(v));
+                }
+                _ => {}
+            }
+        }
+        Ok(())
+    })?;
+    Ok(Value::Null)
+}
+
+/// Layer ▸ Layer Settings: cameras and lights open their own settings; solids (and adjustment
+/// layers, which are solids) edit their Solid Settings. With `affectAll: false`, a solid other
+/// layers also use is copied into a new solid for this layer instead of being changed for all of
+/// them (After Effects' "Affect all layers that use this solid"). `name` renames the layer and
+/// its solid.
+pub(super) fn layer_settings(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, lid) = layer_p(s, p, "layer.settings")?;
+    // Cameras and lights open their own settings (Camera Settings / Light Settings).
+    match s.project.comp(cid).and_then(|c| c.layer(lid)).map(|l| l.source.clone()) {
+        Some(LayerSource::Camera) => return s.execute("layer.cameraSettings", with_layer(p, lid)),
+        Some(LayerSource::Light { .. }) => return s.execute("layer.lightSettings", with_layer(p, lid)),
+        _ => {}
+    }
+    let color = color_p(p, "color");
+    let w = p.get("width").and_then(Value::as_u64).map(limits::size);
+    let h = p.get("height").and_then(Value::as_u64).map(limits::size);
+    let pixel_aspect = pixel_aspect_p(p)?;
+    let name = str_p(p, "name").map(str::trim).filter(|n| !n.is_empty()).map(str::to_string);
+    let affect_all = p.get("affectAll").and_then(Value::as_bool).unwrap_or(true);
+    let solid = s.edit("Layer Settings", None, |proj, _| {
+        let src = layer_mut(proj, cid, lid)?.source.clone();
+        if let Some(n) = &name {
+            layer_mut(proj, cid, lid)?.name = n.clone();
+        }
+        let LayerSource::Solid { item } = src else { return Ok(None) };
+        let shared = proj.comps().flat_map(|(_, c)| &c.layers).filter(|l| l.source == src).count() > 1;
+        let target = if shared && !affect_all {
+            // This layer gets its own copy of the solid.
+            let it = proj.item(item).ok_or_else(|| bad("layer.settings", "the layer's solid is missing"))?.clone();
+            let copy = proj.add_item(name.as_deref().unwrap_or(&it.name), it.label, it.parent, it.kind);
+            layer_mut(proj, cid, lid)?.source = LayerSource::Solid { item: copy };
+            copy
+        } else {
+            item
+        };
+        let it = proj.item_mut(target).ok_or_else(|| bad("layer.settings", "the layer's solid is missing"))?;
+        if let Some(n) = &name {
+            it.name = n.clone();
+        }
+        if let ItemKind::Solid(so) = &mut it.kind {
+            so.color = color.unwrap_or(so.color);
+            so.width = w.unwrap_or(so.width);
+            so.height = h.unwrap_or(so.height);
+            so.pixel_aspect = pixel_aspect.unwrap_or(so.pixel_aspect);
+        }
+        Ok(Some(target))
+    })?;
+    Ok(match solid {
+        Some(item) => json!({"layer": lid.0, "solid": item.0}),
+        None => json!({"layer": lid.0}),
+    })
+}
+
+/// Layer Settings applies to solids (and adjustment layers), nulls, cameras and lights.
+pub(super) fn has_layer_settings(s: &Session) -> std::result::Result<(), String> {
+    has_layers(s)?;
+    let l = s.active_comp().zip(s.state.selected_layers.first()).and_then(|(c, l)| c.layer(*l)).ok_or("select a layer first")?;
+    match l.source {
+        LayerSource::Solid { .. } | LayerSource::Null | LayerSource::Camera | LayerSource::Light { .. } => Ok(()),
+        _ => Err("this kind of layer has no settings".into()),
+    }
+}
+
+fn with_layer(p: &Value, lid: LayerId) -> Value {
+    let mut p = if p.is_object() { p.clone() } else { json!({}) };
+    p["layer"] = json!(lid.0);
+    p
+}
diff --git a/crates/engine/src/commands/layer_menu.rs b/crates/engine/src/cmd/layer_menu.rs
similarity index 100%
rename from crates/engine/src/commands/layer_menu.rs
rename to crates/engine/src/cmd/layer_menu.rs
diff --git a/crates/engine/src/commands/layer_time.rs b/crates/engine/src/cmd/layer_time.rs
similarity index 100%
rename from crates/engine/src/commands/layer_time.rs
rename to crates/engine/src/cmd/layer_time.rs
diff --git a/crates/engine/src/commands/link.rs b/crates/engine/src/cmd/link.rs
similarity index 100%
rename from crates/engine/src/commands/link.rs
rename to crates/engine/src/cmd/link.rs
diff --git a/crates/engine/src/commands/liquify.rs b/crates/engine/src/cmd/liquify.rs
similarity index 100%
rename from crates/engine/src/commands/liquify.rs
rename to crates/engine/src/cmd/liquify.rs
diff --git a/crates/engine/src/commands/lottie.rs b/crates/engine/src/cmd/lottie.rs
similarity index 100%
rename from crates/engine/src/commands/lottie.rs
rename to crates/engine/src/cmd/lottie.rs
diff --git a/crates/engine/src/commands/markers.rs b/crates/engine/src/cmd/markers.rs
similarity index 100%
rename from crates/engine/src/commands/markers.rs
rename to crates/engine/src/cmd/markers.rs
diff --git a/crates/engine/src/commands/mask.rs b/crates/engine/src/cmd/mask.rs
similarity index 100%
rename from crates/engine/src/commands/mask.rs
rename to crates/engine/src/cmd/mask.rs
diff --git a/crates/engine/src/commands/mask_interp.rs b/crates/engine/src/cmd/mask_interp.rs
similarity index 100%
rename from crates/engine/src/commands/mask_interp.rs
rename to crates/engine/src/cmd/mask_interp.rs
diff --git a/crates/engine/src/commands/model3d.rs b/crates/engine/src/cmd/model3d.rs
similarity index 100%
rename from crates/engine/src/commands/model3d.rs
rename to crates/engine/src/cmd/model3d.rs
diff --git a/crates/engine/src/commands/nav_more.rs b/crates/engine/src/cmd/nav_more.rs
similarity index 100%
rename from crates/engine/src/commands/nav_more.rs
rename to crates/engine/src/cmd/nav_more.rs
diff --git a/crates/engine/src/commands/paint.rs b/crates/engine/src/cmd/paint.rs
similarity index 100%
rename from crates/engine/src/commands/paint.rs
rename to crates/engine/src/cmd/paint.rs
diff --git a/crates/engine/src/commands/panels_cmds.rs b/crates/engine/src/cmd/panels_cmds.rs
similarity index 100%
rename from crates/engine/src/commands/panels_cmds.rs
rename to crates/engine/src/cmd/panels_cmds.rs
diff --git a/crates/engine/src/cmd/params.rs b/crates/engine/src/cmd/params.rs
new file mode 100644
index 000000000..7c4e1c292
--- /dev/null
+++ b/crates/engine/src/cmd/params.rs
@@ -0,0 +1,199 @@
+use super::{Comp, EngineError, ItemId, Layer, LayerId, Result, Session, Tick, Value};
+
+/// Hand a frontend-only command to the UI ([`crate::Event::Frontend`]).
+pub(crate) fn frontend(s: &mut Session, id: &str, p: &Value) -> Result<Value> {
+    s.events.push(crate::Event::Frontend { command: id.to_string(), params: p.clone() });
+    Ok(serde_json::json!({"frontend": id}))
+}
+
+/// Match path of a node (`transform/position`, `effects/#2/blurriness` style with `match#n`
+/// occurrences) so it can be found again on another layer.
+pub fn match_path_of(g: &effectcraft_project::PropGroup, uid: effectcraft_project::Uid) -> Option<String> {
+    for c in &g.children {
+        let nth = g.children.iter().take_while(|x| !std::ptr::eq(*x, c)).filter(|x| x.match_id() == c.match_id()).count() + 1;
+        let seg = if nth == 1 { c.match_id().to_string() } else { format!("{}#{nth}", c.match_id()) };
+        if c.uid() == uid {
+            return Some(seg);
+        }
+        if let effectcraft_project::Node::Group(sub) = c
+            && let Some(rest) = match_path_of(sub, uid)
+        {
+            return Some(format!("{seg}/{rest}"));
+        }
+    }
+    None
+}
+
+/// Turn `effects/<match name>[#n]/<property>` (as [`match_path_of`] writes it) into a uid path on
+/// `l`. Path parsing splits on `.`, which would cut a match name like `ec.control.slider` apart.
+/// Any other path, or an effect that is not on the layer, comes back unchanged.
+pub(crate) fn resolve_effect_path(l: &Layer, path: &str) -> String {
+    let Some((seg, tail)) = path.strip_prefix("effects/").and_then(|r| r.split_once('/')) else { return path.to_string() };
+    let (match_id, nth) = match seg.rsplit_once('#') {
+        Some((m, n)) if !m.is_empty() => match n.parse::<usize>() {
+            Ok(n) if n >= 1 => (m, n),
+            _ => (seg, 1),
+        },
+        _ => (seg, 1),
+    };
+    match l.effects().and_then(|fx| fx.groups().filter(|g| g.match_id == match_id).nth(nth - 1)) {
+        Some(g) => format!("effects/@{}/{tail}", g.uid),
+        None => path.to_string(),
+    }
+}
+
+/// Selected properties (leaves) of the active comp as (layer, uid); selected groups expand to
+/// their properties.
+pub(crate) fn selected_leaf_props(s: &Session) -> Vec<(LayerId, effectcraft_project::Uid)> {
+    let Some(comp) = s.active_comp() else { return vec![] };
+    let mut out = vec![];
+    for (lid, uid) in &s.state.selected_props {
+        let Some(l) = comp.layer(*lid) else { continue };
+        if l.props.find(*uid).is_some() {
+            out.push((*lid, *uid));
+        } else if let Some(g) = l.props.find_group(*uid) {
+            g.walk("", &mut |_, p| out.push((*lid, p.uid)));
+        }
+    }
+    out
+}
+
+// ---------- params ----------
+
+pub(crate) fn bad(cmd: &str, msg: impl Into<String>) -> EngineError {
+    EngineError::BadParams { cmd: cmd.into(), msg: msg.into() }
+}
+
+pub(crate) fn str_p<'a>(p: &'a Value, k: &str) -> Option<&'a str> {
+    p.get(k).and_then(Value::as_str)
+}
+
+pub(crate) fn f_p(p: &Value, k: &str) -> Option<f64> {
+    p.get(k).and_then(Value::as_f64)
+}
+
+pub(crate) fn b_p(p: &Value, k: &str) -> Option<bool> {
+    p.get(k).and_then(Value::as_bool)
+}
+
+pub(crate) fn merge_p(p: &Value) -> Option<&str> {
+    str_p(p, "merge")
+}
+
+/// `comp`: item id or name (an all-digit string that names no comp is taken as an id, as MCP
+/// clients often send numbers as strings); default the active comp.
+pub(crate) fn comp_id(s: &Session, p: &Value) -> Result<ItemId> {
+    let missing = |v: &Value| EngineError::NoSuchComp(v.to_string());
+    match p.get("comp") {
+        Some(v @ Value::Number(n)) => n.as_u64().map(ItemId).filter(|id| s.project.comp(*id).is_some()).ok_or_else(|| missing(v)),
+        Some(v @ Value::String(name)) => s
+            .project
+            .items
+            .values()
+            .find(|i| &i.name == name && i.as_comp().is_some())
+            .map(|i| i.id)
+            .or_else(|| digits_id(name).map(ItemId).filter(|id| s.project.comp(*id).is_some()))
+            .ok_or_else(|| missing(v)),
+        _ => s.active_comp_id().ok_or(EngineError::NoComp),
+    }
+}
+
+/// An all-ASCII-digit string as a number (`"98"` -> 98); anything else (names, `#n`, signs) is `None`.
+fn digits_id(s: &str) -> Option<u64> {
+    if s.is_empty() || !s.bytes().all(|b| b.is_ascii_digit()) {
+        return None;
+    }
+    s.parse().ok()
+}
+
+/// Resolve a layer reference: id (number), `#n` / index (1-based), or name. An all-digit string
+/// that names no layer is resolved as the number it spells.
+pub(crate) fn resolve_layer(comp: &Comp, v: &Value) -> Option<LayerId> {
+    match v {
+        Value::Number(n) => {
+            let id = n.as_u64()?;
+            if comp.layer(LayerId(id)).is_some() { Some(LayerId(id)) } else { comp.layers.get((id as usize).checked_sub(1)?).map(|l| l.id) }
+        }
+        Value::String(s) => {
+            if let Some(i) = s.strip_prefix('#').and_then(|i| i.parse::<usize>().ok()) {
+                return comp.layers.get(i.checked_sub(1)?).map(|l| l.id);
+            }
+            comp.layers.iter().find(|l| &l.name == s).map(|l| l.id).or_else(|| digits_id(s).and_then(|id| resolve_layer(comp, &Value::from(id))))
+        }
+        _ => None,
+    }
+}
+
+/// `layer` param or the first selected layer.
+pub(crate) fn layer_p(s: &Session, p: &Value, cmd: &str) -> Result<(ItemId, LayerId)> {
+    let cid = comp_id(s, p)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    if let Some(v) = p.get("layer") {
+        return resolve_layer(comp, v).map(|l| (cid, l)).ok_or_else(|| bad(cmd, format!("no layer {v}")));
+    }
+    s.state
+        .selected_layers
+        .first()
+        .copied()
+        .filter(|l| comp.layer(*l).is_some())
+        .map(|l| (cid, l))
+        .ok_or_else(|| bad(cmd, "no `layer` given and no layer selected"))
+}
+
+/// `layers` param (array) or the selection.
+pub(crate) fn layers_p(s: &Session, p: &Value) -> Result<(ItemId, Vec<LayerId>)> {
+    let cid = comp_id(s, p)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    // Explicit references that match no layer are an error (agents otherwise get a silent no-op).
+    let resolve =
+        |v: &Value| resolve_layer(comp, v).ok_or_else(|| EngineError::Other(format!("no layer {v} (use a layer id, \"#n\" or a name from comp.info)")));
+    if let Some(Value::Array(a)) = p.get("layers") {
+        return Ok((cid, a.iter().map(resolve).collect::<Result<_>>()?));
+    }
+    if let Some(v) = p.get("layer").filter(|v| !v.is_null()) {
+        return Ok((cid, vec![resolve(v)?]));
+    }
+    Ok((cid, s.state.selected_layers.iter().copied().filter(|l| comp.layer(*l).is_some()).collect()))
+}
+
+/// Whether a layer can be picked by the user (Select All, Ctrl+Up/Down, a Timeline click): not
+/// locked, and not hidden by the composition's Hide Shy Layers.
+pub(crate) fn selectable(comp: &Comp, l: &Layer) -> bool {
+    !(l.switches.locked || (comp.hide_shy && l.switches.shy))
+}
+
+/// The layers of `ids` a command may edit: locked layers are left alone, as in After Effects.
+/// An error when every one of them is locked.
+pub(crate) fn unlocked(s: &Session, cid: ItemId, ids: Vec<LayerId>, cmd: &str) -> Result<Vec<LayerId>> {
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let locked = |id: &LayerId| comp.layer(*id).is_some_and(|l| l.switches.locked);
+    match ids.iter().find(|id| locked(id)) {
+        Some(first) if ids.iter().all(locked) => {
+            let name = comp.layer(*first).map(|l| l.name.clone()).unwrap_or_default();
+            Err(bad(cmd, format!("“{name}” is locked (Layer ▸ Switches ▸ Unlock All Layers)")))
+        }
+        _ => Ok(ids.into_iter().filter(|id| !locked(id)).collect()),
+    }
+}
+
+/// `visible: [{layer, prop}]`: the properties the Timeline shows (J / K and Select All
+/// Keyframes use only those, as in After Effects). `None` when not given.
+pub(crate) fn visible_p(p: &Value) -> Option<Vec<(LayerId, effectcraft_project::Uid)>> {
+    let a = p.get("visible")?.as_array()?;
+    Some(a.iter().filter_map(|v| Some((LayerId(v.get("layer")?.as_u64()?), v.get("prop")?.as_u64()?))).collect())
+}
+
+/// `time` (seconds) or `frame` param, else the CTI.
+pub(crate) fn time_p(s: &Session, p: &Value, comp: Option<&Comp>) -> Tick {
+    if let Some(t) = f_p(p, "time") {
+        return Tick::from_seconds_f64(t);
+    }
+    if let (Some(f), Some(c)) = (p.get("frame").and_then(Value::as_i64), comp) {
+        return c.frame_rate.tick_of(f);
+    }
+    s.time()
+}
+
+pub(crate) fn layer_mut(p: &mut effectcraft_project::Project, cid: ItemId, lid: LayerId) -> Result<&mut Layer> {
+    p.comp_mut(cid).ok_or(EngineError::NoComp)?.layer_mut(lid).ok_or(EngineError::Project(effectcraft_project::ProjectError::NoLayer(lid)))
+}
diff --git a/crates/engine/src/commands/path_nulls.rs b/crates/engine/src/cmd/path_nulls.rs
similarity index 100%
rename from crates/engine/src/commands/path_nulls.rs
rename to crates/engine/src/cmd/path_nulls.rs
diff --git a/crates/engine/src/commands/paths.rs b/crates/engine/src/cmd/paths.rs
similarity index 98%
rename from crates/engine/src/commands/paths.rs
rename to crates/engine/src/cmd/paths.rs
index 96767d967..afd7aba12 100644
--- a/crates/engine/src/commands/paths.rs
+++ b/crates/engine/src/cmd/paths.rs
@@ -121,16 +121,16 @@ fn parametric_path(g: &PropGroup, lt: effectcraft_time::Tick) -> Option<ShapePat
     let path = match g.match_id.as_str() {
         "rect" => effectcraft_path::rect(v2("size", [100.0; 2]), v2("position", [0.0; 2]), f("roundness", 0.0)),
         "ellipse" => effectcraft_path::ellipse(v2("size", [100.0; 2]), v2("position", [0.0; 2])),
-        "star" => effectcraft_path::polystar(
-            g.prop("type").map_or(0, |pr| pr.value_at(lt).as_enum()) == 0,
-            f("points", 5.0),
-            v2("position", [0.0; 2]),
-            f("rotation", 0.0),
-            f("innerRadius", 50.0),
-            f("outerRadius", 100.0),
-            f("innerRoundness", 0.0),
-            f("outerRoundness", 0.0),
-        ),
+        "star" => effectcraft_path::polystar(effectcraft_path::Polystar {
+            star: g.prop("type").map_or(0, |pr| pr.value_at(lt).as_enum()) == 0,
+            points: f("points", 5.0),
+            pos: v2("position", [0.0; 2]),
+            rotation: f("rotation", 0.0),
+            inner: f("innerRadius", 50.0),
+            outer: f("outerRadius", 100.0),
+            inner_round: f("innerRoundness", 0.0),
+            outer_round: f("outerRoundness", 0.0),
+        }),
         _ => return None,
     };
     // A closed parametric shape is one subpath; anything else would not be this shape.
diff --git a/crates/engine/src/commands/project_items.rs b/crates/engine/src/cmd/project_items.rs
similarity index 100%
rename from crates/engine/src/commands/project_items.rs
rename to crates/engine/src/cmd/project_items.rs
diff --git a/crates/engine/src/commands/prop.rs b/crates/engine/src/cmd/prop.rs
similarity index 100%
rename from crates/engine/src/commands/prop.rs
rename to crates/engine/src/cmd/prop.rs
diff --git a/crates/engine/src/commands/prop_groups.rs b/crates/engine/src/cmd/prop_groups.rs
similarity index 100%
rename from crates/engine/src/commands/prop_groups.rs
rename to crates/engine/src/cmd/prop_groups.rs
diff --git a/crates/engine/src/commands/proxy.rs b/crates/engine/src/cmd/proxy.rs
similarity index 100%
rename from crates/engine/src/commands/proxy.rs
rename to crates/engine/src/cmd/proxy.rs
diff --git a/crates/engine/src/commands/puppet.rs b/crates/engine/src/cmd/puppet.rs
similarity index 100%
rename from crates/engine/src/commands/puppet.rs
rename to crates/engine/src/cmd/puppet.rs
diff --git a/crates/engine/src/commands/query.rs b/crates/engine/src/cmd/query.rs
similarity index 100%
rename from crates/engine/src/commands/query.rs
rename to crates/engine/src/cmd/query.rs
diff --git a/crates/engine/src/commands/quick_offset.rs b/crates/engine/src/cmd/quick_offset.rs
similarity index 100%
rename from crates/engine/src/commands/quick_offset.rs
rename to crates/engine/src/cmd/quick_offset.rs
diff --git a/crates/engine/src/commands/relink.rs b/crates/engine/src/cmd/relink.rs
similarity index 100%
rename from crates/engine/src/commands/relink.rs
rename to crates/engine/src/cmd/relink.rs
diff --git a/crates/engine/src/commands/relink_moved.rs b/crates/engine/src/cmd/relink_moved.rs
similarity index 100%
rename from crates/engine/src/commands/relink_moved.rs
rename to crates/engine/src/cmd/relink_moved.rs
diff --git a/crates/engine/src/commands/render_queue.rs b/crates/engine/src/cmd/render_queue.rs
similarity index 98%
rename from crates/engine/src/commands/render_queue.rs
rename to crates/engine/src/cmd/render_queue.rs
index 09a7c7d2f..1cda510e0 100644
--- a/crates/engine/src/commands/render_queue.rs
+++ b/crates/engine/src/cmd/render_queue.rs
@@ -205,23 +205,8 @@ fn apply_om_template(om: &mut OutputModule, t: &OutputModule) {
 /// The `format` parameter's values.
 const FORMATS: &str = "format: h264|hevc|av1|prores|uncompressed|webm|png|jpeg|tiff|exr|gif|wav|aiff";
 
-/// Apply Output Module parameters (`template` first). `roi`: the viewer's region of interest
-/// (captured by `crop.useRoi`).
-fn apply_output(om: &mut OutputModule, templates: &RenderTemplates, roi: Option<[f64; 4]>, p: &Value, cmd: &str) -> Result<bool> {
-    let mut any = false;
-    if let Some(t) = str_p(p, "template") {
-        let t = templates.output_module(t).ok_or_else(|| bad(cmd, format!("no Output Module template “{t}”")))?;
-        apply_om_template(om, &t);
-        any = true;
-    }
-    let before = om.clone();
-    if let Some(f) = str_p(p, "format") {
-        let f = OutputFormat::from_name(f).ok_or_else(|| bad(cmd, FORMATS))?;
-        om.set_format(f);
-    }
-    // Before Channels: the WebM codec decides whether alpha can be written, so an explicit
-    // `channels: rgba` with `webmCodec: av1` is refused rather than dropped (#166).
-    any |= apply_codec_options(om, p, cmd)?;
+/// `channels` (refusing RGBA where the format has no alpha) and `color`/`alphaMode`.
+fn apply_channels_and_alpha(om: &mut OutputModule, p: &Value, cmd: &str) -> Result<()> {
     if let Some(c) = str_p(p, "channels") {
         om.channels = match c.to_ascii_lowercase().replace([' ', '+'], "").as_str() {
             "rgb" => Channels::Rgb,
@@ -244,21 +229,11 @@ fn apply_output(om: &mut OutputModule, templates: &RenderTemplates, roi: Option<
             _ => return Err(bad(cmd, "color: straight|premultiplied")),
         };
     }
-    if let Some(q) = f_p(p, "quality") {
-        om.quality = q.clamp(1.0, 100.0) as u8;
-    }
-    if let Some(b) = f_p(p, "bitrate") {
-        om.bitrate_kbps = b.clamp(50.0, 500_000.0) as u32;
-    }
-    if let Some(b) = b_p(p, "webmBitrate") {
-        om.webm_bitrate = b;
-    }
-    if let Some(k) = p.get("keyframeInterval").and_then(Value::as_u64) {
-        om.keyframe_interval = k.min(100_000) as u32;
-    }
-    if let Some(pp) = str_p(p, "proresProfile") {
-        om.prores_profile = ProResProfile::from_name(pp).ok_or_else(|| bad(cmd, "proresProfile: proxy|lt|standard|hq|4444|4444xq"))?;
-    }
+    Ok(())
+}
+
+/// `crop` plus the flat dialog keys (`cropTop`… and `resizeWidth`/`resizeHeight`).
+fn apply_crop(om: &mut OutputModule, roi: Option<[f64; 4]>, p: &Value, cmd: &str) -> Result<()> {
     match p.get("crop") {
         Some(Value::Bool(b)) => om.crop.enabled = *b,
         Some(Value::Object(c)) => {
@@ -298,6 +273,11 @@ fn apply_output(om: &mut OutputModule, templates: &RenderTemplates, roi: Option<
             om.resize.enabled = true;
         }
     }
+    Ok(())
+}
+
+/// `resize` (bool or object).
+fn apply_resize(om: &mut OutputModule, p: &Value, cmd: &str) -> Result<()> {
     match p.get("resize") {
         Some(Value::Bool(b)) => om.resize.enabled = *b,
         Some(Value::Object(r)) => {
@@ -328,6 +308,44 @@ fn apply_output(om: &mut OutputModule, templates: &RenderTemplates, roi: Option<
         Some(Value::Null) | None => {}
         Some(_) => return Err(bad(cmd, "resize: bool or {enabled?, preset?, width?, height?, lockAspect?, quality?: low|high}")),
     }
+    Ok(())
+}
+
+/// Apply Output Module parameters (`template` first). `roi`: the viewer's region of interest
+/// (captured by `crop.useRoi`).
+fn apply_output(om: &mut OutputModule, templates: &RenderTemplates, roi: Option<[f64; 4]>, p: &Value, cmd: &str) -> Result<bool> {
+    let mut any = false;
+    if let Some(t) = str_p(p, "template") {
+        let t = templates.output_module(t).ok_or_else(|| bad(cmd, format!("no Output Module template “{t}”")))?;
+        apply_om_template(om, &t);
+        any = true;
+    }
+    let before = om.clone();
+    if let Some(f) = str_p(p, "format") {
+        let f = OutputFormat::from_name(f).ok_or_else(|| bad(cmd, FORMATS))?;
+        om.set_format(f);
+    }
+    // Before Channels: the WebM codec decides whether alpha can be written, so an explicit
+    // `channels: rgba` with `webmCodec: av1` is refused rather than dropped (#166).
+    any |= apply_codec_options(om, p, cmd)?;
+    apply_channels_and_alpha(om, p, cmd)?;
+    if let Some(q) = f_p(p, "quality") {
+        om.quality = q.clamp(1.0, 100.0) as u8;
+    }
+    if let Some(b) = f_p(p, "bitrate") {
+        om.bitrate_kbps = b.clamp(50.0, 500_000.0) as u32;
+    }
+    if let Some(b) = b_p(p, "webmBitrate") {
+        om.webm_bitrate = b;
+    }
+    if let Some(k) = p.get("keyframeInterval").and_then(Value::as_u64) {
+        om.keyframe_interval = k.min(100_000) as u32;
+    }
+    if let Some(pp) = str_p(p, "proresProfile") {
+        om.prores_profile = ProResProfile::from_name(pp).ok_or_else(|| bad(cmd, "proresProfile: proxy|lt|standard|hq|4444|4444xq"))?;
+    }
+    apply_crop(om, roi, p, cmd)?;
+    apply_resize(om, p, cmd)?;
     if let Some(a) = p.get("audio") {
         om.audio = match a {
             Value::Bool(true) => AudioOutput::On,
diff --git a/crates/engine/src/commands/rig3d.rs b/crates/engine/src/cmd/rig3d.rs
similarity index 100%
rename from crates/engine/src/commands/rig3d.rs
rename to crates/engine/src/cmd/rig3d.rs
diff --git a/crates/engine/src/commands/roto_cmds.rs b/crates/engine/src/cmd/roto_cmds.rs
similarity index 100%
rename from crates/engine/src/commands/roto_cmds.rs
rename to crates/engine/src/cmd/roto_cmds.rs
diff --git a/crates/engine/src/commands/scene_detect.rs b/crates/engine/src/cmd/scene_detect.rs
similarity index 100%
rename from crates/engine/src/commands/scene_detect.rs
rename to crates/engine/src/cmd/scene_detect.rs
diff --git a/crates/engine/src/cmd/schema.rs b/crates/engine/src/cmd/schema.rs
new file mode 100644
index 000000000..c74ab277e
--- /dev/null
+++ b/crates/engine/src/cmd/schema.rs
@@ -0,0 +1,119 @@
+use super::params::bad;
+use super::{CommandSpec, Result, Value};
+
+// ---------- parameter validation (agents) ----------
+
+/// Top-level keys accepted by a params doc such as `{layers: [id|name|#n], add?, toggle?}` or
+/// `{time? (s) | frame? | timecode?}`; `None` when the doc isn't a `{…}` key list.
+pub fn accepted_params(doc: &str) -> Option<Vec<String>> {
+    let body = doc.trim().strip_prefix('{')?;
+    // Top-level pieces up to the matching close brace, split at `,` and `|`; `:` starts a value.
+    let (mut keys, mut cur, mut depth, mut in_value) = (Vec::new(), String::new(), 0i32, false);
+    let push = |cur: &mut String, keys: &mut Vec<String>| {
+        let k: String = cur.trim().chars().take_while(|c| c.is_ascii_alphanumeric() || *c == '_').collect();
+        if !k.is_empty() && !keys.contains(&k) {
+            keys.push(k);
+        }
+        cur.clear();
+    };
+    for c in body.chars() {
+        match c {
+            '{' | '[' | '(' => depth += 1,
+            ']' | ')' => depth -= 1,
+            '}' if depth == 0 => {
+                push(&mut cur, &mut keys);
+                return Some(keys);
+            }
+            '}' => depth -= 1,
+            ',' if depth == 0 => {
+                push(&mut cur, &mut keys);
+                in_value = false;
+            }
+            '|' if depth == 0 && !in_value => push(&mut cur, &mut keys),
+            ':' if depth == 0 => {
+                push(&mut cur, &mut keys);
+                in_value = true;
+            }
+            _ if depth == 0 && !in_value => cur.push(c),
+            _ => {}
+        }
+    }
+    None
+}
+
+/// Top-level pieces of a params doc (split at depth-0 commas), e.g. `{layer?, path|prop, value}`
+/// → `["layer?", "path|prop", "value"]`.
+fn doc_pieces(doc: &str) -> Option<Vec<String>> {
+    let body = doc.trim().strip_prefix('{')?;
+    let (mut out, mut cur, mut depth) = (Vec::new(), String::new(), 0i32);
+    for c in body.chars() {
+        match c {
+            '{' | '[' | '(' => depth += 1,
+            ']' | ')' => depth -= 1,
+            '}' if depth == 0 => {
+                if !cur.trim().is_empty() {
+                    out.push(cur.trim().to_string());
+                }
+                return Some(out);
+            }
+            '}' => depth -= 1,
+            ',' if depth == 0 => {
+                if !cur.trim().is_empty() {
+                    out.push(cur.trim().to_string());
+                }
+                cur.clear();
+                continue;
+            }
+            _ => {}
+        }
+        cur.push(c);
+    }
+    None
+}
+
+/// The JSON Schema of a command's parameters, derived from its params doc: one property per
+/// accepted key (described by its piece of the doc), no others. MCP `describe_command` and
+/// `list_commands {schemas: true}` serve it.
+pub fn params_schema(spec: &CommandSpec) -> Value {
+    let mut props = serde_json::Map::new();
+    let mut required = vec![];
+    for piece in doc_pieces(spec.params).unwrap_or_default() {
+        let keys = accepted_params(&format!("{{{piece}}}")).unwrap_or_default();
+        let alternatives = keys.len() > 1;
+        for k in keys {
+            // `key?` is optional; so is any key with alternatives (`path|prop`).
+            let optional = alternatives || piece.contains(&format!("{k}?"));
+            if !optional && !required.contains(&k) {
+                required.push(k.clone());
+            }
+            props.insert(k, serde_json::json!({"description": piece}));
+        }
+    }
+    serde_json::json!({
+        "type": "object",
+        "description": spec.params,
+        "properties": props,
+        "required": required,
+        "additionalProperties": accepted_params(spec.params).is_none(),
+    })
+}
+
+/// Keys every command understands (comp targeting, gesture merging) and accepted aliases.
+const ALWAYS_OK: &[&str] = &["comp", "merge"];
+
+const ALIASES: &[(&str, &str)] = &[("layers", "layer"), ("layer", "layers"), ("time", "frame"), ("frameRate", "fps"), ("properties", "property")];
+
+/// Reject unknown top-level parameters (typos, guessed names) with the list of accepted keys.
+pub fn check_params(spec: &CommandSpec, params: &Value) -> Result<()> {
+    let (Some(obj), Some(accepted)) = (params.as_object(), accepted_params(spec.params)) else { return Ok(()) };
+    let ok = |k: &str| ALWAYS_OK.contains(&k) || accepted.iter().any(|a| a == k || ALIASES.iter().any(|(doc, alias)| doc == a && *alias == k));
+    let unknown: Vec<&str> = obj.keys().map(String::as_str).filter(|k| !ok(k)).collect();
+    if unknown.is_empty() {
+        return Ok(());
+    }
+    let list = if accepted.is_empty() { "none".to_string() } else { accepted.join(", ") };
+    Err(bad(
+        spec.id,
+        format!("unknown parameter(s) {}; accepted: {list} (doc: {})", unknown.iter().map(|k| format!("`{k}`")).collect::<Vec<_>>().join(", "), spec.params),
+    ))
+}
diff --git a/crates/engine/src/commands/scripts.rs b/crates/engine/src/cmd/scripts.rs
similarity index 74%
rename from crates/engine/src/commands/scripts.rs
rename to crates/engine/src/cmd/scripts.rs
index d352e636c..635429d6b 100644
--- a/crates/engine/src/commands/scripts.rs
+++ b/crates/engine/src/cmd/scripts.rs
@@ -235,13 +235,17 @@ fn uninstall(s: &mut Session, p: &Value) -> Result<Value> {
 }
 
 /// Run an installed or bundled script by name (File ▸ Scripts ▸ `<name>`). A ScriptUI panel run
-/// this way gets `this` = a floating palette-like panel window.
+/// this way gets `this` = a floating palette-like panel window. A script listed under File ▸
+/// Scripts runs before a panel of the same name.
 pub(crate) fn run_named(s: &mut Session, name: &str) -> Result<Value> {
-    let (panel, code) = script_code(s, name, None).ok_or_else(|| bad("file.runScript", format!("no installed or bundled script `{name}`")))?;
+    let found = script_code(s, name, Some(false)).or_else(|| script_code(s, name, None));
+    let (panel, code) = found.ok_or_else(|| bad("file.runScript", format!("no installed or bundled script `{name}`")))?;
     if panel {
         return open_panel(s, &json!({"name": name}));
     }
-    super::file_more::run_js_named(s, &code, name)
+    let result = super::file_more::run_js_named(s, &code, name)?;
+    super::file_more::remember_script(s, crate::prefs::RecentScript::Name(name.to_string()));
+    Ok(result)
 }
 
 /// The code a ScriptUI panel runs with: `this` is a dockable Panel titled after the script.
@@ -553,6 +557,175 @@ mod tests {
         let _ = std::fs::remove_dir_all(&root);
     }
 
+    /// File ▸ Scripts ▸ Recent Script Files: the ten scripts run last, newest first, kept in the
+    /// settings; Cmd+Alt+Shift+D runs the first one again.
+    #[test]
+    fn recent_script_files_run_again() {
+        use crate::prefs::{MAX_RECENT_SCRIPTS, PREFS_FILE, Prefs, RecentScript};
+        let (mut s, root) = session_in_tmp("recent");
+        assert_eq!(crate::menus::dynamic(&s, "recentScripts", &Default::default()), (vec![], Some("No Recent Script Files")));
+        assert!(bad_params(&s.execute("file.runScript", json!({"recent": 0}))));
+        assert_eq!(s.shortcuts().shortcut_of("file.runScript", &json!({"recent": 0})), Some("Cmd+Alt+Shift+D"));
+        let tool = root.join("Tool.jsx");
+        std::fs::write(&tool, "tool").unwrap();
+        let tool = tool.to_string_lossy().into_owned();
+        s.execute("file.runScript", json!({"path": tool})).unwrap();
+        s.execute("file.runScript", json!({"name": "Rename Layers.jsx"})).unwrap();
+        // A ScriptUI panel opened from File ▸ Scripts is not a recent script file.
+        std::fs::write(root.join("settings").join(PANELS_DIR).join("Panel.jsx"), "panel").unwrap();
+        s.execute("file.runScript", json!({"name": "Panel.jsx"})).unwrap();
+        let (path, name) = (RecentScript::Path(tool.clone()), RecentScript::Name("Rename Layers.jsx".into()));
+        assert_eq!(s.prefs.recent_scripts, [name.clone(), path.clone()]);
+        let (e, _) = crate::menus::dynamic(&s, "recentScripts", &Default::default());
+        assert_eq!(e.iter().map(|e| e.label.as_str()).collect::<Vec<_>>(), ["Rename Layers.jsx", "Tool.jsx"]);
+        assert_eq!((e[1].command.as_str(), &e[1].params), ("file.runScript", &json!({"recent": 1})));
+        // Running one again runs that file and moves it to the top.
+        assert_eq!(s.execute("file.runScript", json!({"recent": 1})).unwrap()["ran"], "tool");
+        assert_eq!(s.prefs.recent_scripts, [path.clone(), name.clone()]);
+        let sample = BUNDLED.iter().find(|b| b.0 == "Rename Layers.jsx").unwrap().3;
+        assert_eq!(s.execute("file.runScript", json!({"recent": 1})).unwrap()["ran"], sample);
+        assert!(bad_params(&s.execute("file.runScript", json!({"recent": 2}))));
+        assert!(bad_params(&s.execute("file.runScript", json!({"recent": "Tool.jsx"}))));
+        // A file named like a bundled script runs again as that file.
+        let local = root.join("Rename Layers.jsx");
+        std::fs::write(&local, "local").unwrap();
+        s.execute("file.runScript", json!({"path": local.to_string_lossy()})).unwrap();
+        assert_eq!(s.execute("file.runScript", json!({"recent": 0})).unwrap()["ran"], "local");
+        assert_eq!(s.execute("file.runScript", json!({"recent": 1})).unwrap()["ran"], sample);
+        // Ten at most, saved with the settings.
+        let mut last = String::new();
+        for i in 0..MAX_RECENT_SCRIPTS + 2 {
+            let f = root.join(format!("Step {i}.jsonl"));
+            std::fs::write(&f, "").unwrap();
+            last = f.to_string_lossy().into_owned();
+            s.execute("file.runScript", json!({"path": last})).unwrap();
+        }
+        assert_eq!(s.prefs.recent_scripts.len(), MAX_RECENT_SCRIPTS);
+        assert_eq!(s.prefs.recent_scripts[0], RecentScript::Path(last));
+        let saved = std::fs::read_to_string(root.join("settings").join(PREFS_FILE)).unwrap();
+        assert_eq!(Prefs::from_json(&saved).recent_scripts, s.prefs.recent_scripts);
+        let _ = std::fs::remove_dir_all(&root);
+    }
+
+    #[test]
+    fn recent_script_history_uses_the_selected_script() {
+        let (mut s, root) = session_in_tmp("recent-panel-collision");
+        let name = "Rename Layers.jsx";
+        std::fs::write(root.join("settings").join(PANELS_DIR).join(name), "panel").unwrap();
+        assert!(super::scripts(&s).iter().any(|entry| entry.name == name && !entry.panel));
+        assert!(script_code(&s, name, None).unwrap().0);
+        let sample = BUNDLED.iter().find(|b| b.0 == name).unwrap().3;
+        assert_eq!(s.execute("file.runScript", json!({"name": name})).unwrap()["ran"], sample);
+        assert!(super::open_panel_names(&s).is_empty(), "the listed script runs instead of the panel");
+        assert_eq!(s.prefs.recent_scripts, [crate::prefs::RecentScript::Name(name.to_string())]);
+        let _ = std::fs::remove_dir_all(root);
+    }
+
+    #[test]
+    fn recent_script_history_keeps_successful_entries_when_scripts_fail() {
+        fn fail_or_echo(_: &mut Session, request: &ScriptRequest) -> Value {
+            if request.code == "fail" { json!({"error": {"message": "script failed"}}) } else { json!({"ran": request.code}) }
+        }
+        let (mut s, root) = session_in_tmp("recent-failed");
+        s.script = Some(fail_or_echo);
+        let good = root.join("good.jsonl");
+        std::fs::write(&good, "[]").unwrap();
+        s.execute("file.runScript", json!({"path": good})).unwrap();
+        let remembered = s.prefs.recent_scripts.clone();
+        for (name, code) in [("parse.jsonl", "{"), ("step.jsonl", r#"{"command":"does.not.exist"}"#), ("missing-command.jsonl", "{}"), ("runtime.jsx", "fail")]
+        {
+            let path = root.join(name);
+            std::fs::write(&path, code).unwrap();
+            assert!(s.execute("file.runScript", json!({"path": path})).is_err(), "{name}");
+            assert_eq!(s.prefs.recent_scripts, remembered, "{name}");
+        }
+        std::fs::write(root.join("settings").join(SCRIPTS_DIR).join("Failed.jsx"), "fail").unwrap();
+        assert!(s.execute("file.runScript", json!({"name": "Failed.jsx"})).is_err());
+        assert_eq!(s.prefs.recent_scripts, remembered);
+        let _ = std::fs::remove_dir_all(root);
+    }
+
+    /// Reads relative paths from a working directory that a test can change.
+    struct InFolder(std::sync::Mutex<PathBuf>);
+
+    impl InFolder {
+        fn at(&self, path: &str) -> PathBuf {
+            self.0.lock().unwrap().join(path)
+        }
+    }
+
+    impl crate::Services for InFolder {
+        fn read_file(&self, path: &str) -> std::io::Result<Vec<u8>> {
+            std::fs::read(self.at(path))
+        }
+        fn write_file(&self, path: &str, data: &[u8]) -> std::io::Result<()> {
+            std::fs::write(self.at(path), data)
+        }
+        fn full_path(&self, path: &str) -> Option<String> {
+            Some(self.at(path).to_string_lossy().into_owned())
+        }
+    }
+
+    /// Reads from a folder but can't make paths absolute.
+    struct NoFullPath(PathBuf);
+
+    impl crate::Services for NoFullPath {
+        fn read_file(&self, path: &str) -> std::io::Result<Vec<u8>> {
+            std::fs::read(self.0.join(path))
+        }
+        fn write_file(&self, path: &str, data: &[u8]) -> std::io::Result<()> {
+            std::fs::write(self.0.join(path), data)
+        }
+        fn full_path(&self, _path: &str) -> Option<String> {
+            None
+        }
+    }
+
+    /// A script whose path can't be made absolute still runs, and Recent Script Files does not
+    /// keep its relative path.
+    #[test]
+    fn unresolved_script_paths_are_not_remembered() {
+        let (mut s, root) = session_in_tmp("recent-unresolved");
+        std::fs::write(root.join("Tool.jsx"), "a").unwrap();
+        std::fs::write(root.join("steps.jsonl"), "[]").unwrap();
+        s.services = Arc::new(NoFullPath(root.clone()));
+        assert_eq!(s.execute("file.runScript", json!({"path": "Tool.jsx"})).unwrap()["ran"], "a");
+        s.execute("file.runScript", json!({"path": "steps.jsonl"})).unwrap();
+        assert!(s.prefs.recent_scripts.is_empty(), "{:?}", s.prefs.recent_scripts);
+        let _ = std::fs::remove_dir_all(&root);
+    }
+
+    /// A script run from a relative path runs the same file again from Recent Script Files after
+    /// the working directory changes, and two scripts with the same file name show their paths.
+    #[test]
+    fn recent_script_files_keep_the_file_that_ran() {
+        let (mut s, root) = session_in_tmp("recent-relative");
+        let (a, b) = (root.join("a"), root.join("b"));
+        for (dir, code) in [(&a, "a"), (&b, "b")] {
+            std::fs::create_dir_all(dir).unwrap();
+            std::fs::write(dir.join("Tool.jsx"), code).unwrap();
+        }
+        let services = Arc::new(InFolder(std::sync::Mutex::new(a.clone())));
+        s.services = services.clone();
+        assert_eq!(s.execute("file.runScript", json!({"path": "Tool.jsx"})).unwrap()["ran"], "a");
+        *services.0.lock().unwrap() = b.clone();
+        assert_eq!(s.execute("file.runScript", json!({"recent": 0})).unwrap()["ran"], "a");
+        let (e, _) = crate::menus::dynamic(&s, "recentScripts", &Default::default());
+        assert_eq!(e.iter().map(|e| e.label.as_str()).collect::<Vec<_>>(), ["Tool.jsx"]);
+        assert_eq!(s.execute("file.runScript", json!({"path": "Tool.jsx"})).unwrap()["ran"], "b");
+        let (e, _) = crate::menus::dynamic(&s, "recentScripts", &Default::default());
+        let (a, b) = (a.join("Tool.jsx").to_string_lossy().into_owned(), b.join("Tool.jsx").to_string_lossy().into_owned());
+        assert_eq!(e.iter().map(|e| e.label.as_str()).collect::<Vec<_>>(), [b.as_str(), a.as_str()]);
+        let _ = std::fs::remove_dir_all(&root);
+    }
+
+    /// Native script paths are kept absolute.
+    #[test]
+    fn native_full_paths_are_absolute() {
+        use crate::Services;
+        assert!(crate::FsServices.full_path("Tool.jsx").is_some_and(|p| std::path::Path::new(&p).is_absolute()));
+    }
+
     #[test]
     fn only_scripts_are_read_or_removed() {
         // A settings file in the Scripts folder that is not a script (.jsx / .js).
diff --git a/crates/engine/src/commands/settings.rs b/crates/engine/src/cmd/settings.rs
similarity index 100%
rename from crates/engine/src/commands/settings.rs
rename to crates/engine/src/cmd/settings.rs
diff --git a/crates/engine/src/commands/shape_stroke.rs b/crates/engine/src/cmd/shape_stroke.rs
similarity index 100%
rename from crates/engine/src/commands/shape_stroke.rs
rename to crates/engine/src/cmd/shape_stroke.rs
diff --git a/crates/engine/src/commands/shape_tool.rs b/crates/engine/src/cmd/shape_tool.rs
similarity index 98%
rename from crates/engine/src/commands/shape_tool.rs
rename to crates/engine/src/cmd/shape_tool.rs
index a48c32b7f..e1f3607b1 100644
--- a/crates/engine/src/commands/shape_tool.rs
+++ b/crates/engine/src/cmd/shape_tool.rs
@@ -221,7 +221,16 @@ pub fn mask_path(kind: &str, centre: [f64; 2], size: [f64; 2]) -> Option<ShapePa
         "rounded" | "roundedRect" => effectcraft_path::rect(size, centre, roundness(size)),
         k => {
             let (star, points, outer, inner) = polystar_of(k, size)?;
-            effectcraft_path::polystar(star, points, centre, 0.0, inner, outer, 0.0, 0.0)
+            effectcraft_path::polystar(effectcraft_path::Polystar {
+                star,
+                points,
+                pos: centre,
+                rotation: 0.0,
+                inner,
+                outer,
+                inner_round: 0.0,
+                outer_round: 0.0,
+            })
         }
     };
     effectcraft_path::from_kurbo(&bez).into_iter().next()
diff --git a/crates/engine/src/commands/stubs.rs b/crates/engine/src/cmd/stubs.rs
similarity index 100%
rename from crates/engine/src/commands/stubs.rs
rename to crates/engine/src/cmd/stubs.rs
diff --git a/crates/engine/src/commands/styles.rs b/crates/engine/src/cmd/styles.rs
similarity index 100%
rename from crates/engine/src/commands/styles.rs
rename to crates/engine/src/cmd/styles.rs
diff --git a/crates/engine/src/commands/text_anim.rs b/crates/engine/src/cmd/text_anim.rs
similarity index 100%
rename from crates/engine/src/commands/text_anim.rs
rename to crates/engine/src/cmd/text_anim.rs
diff --git a/crates/engine/src/commands/text_edit.rs b/crates/engine/src/cmd/text_edit.rs
similarity index 100%
rename from crates/engine/src/commands/text_edit.rs
rename to crates/engine/src/cmd/text_edit.rs
diff --git a/crates/engine/src/commands/three_d.rs b/crates/engine/src/cmd/three_d.rs
similarity index 100%
rename from crates/engine/src/commands/three_d.rs
rename to crates/engine/src/cmd/three_d.rs
diff --git a/crates/engine/src/commands/time.rs b/crates/engine/src/cmd/time.rs
similarity index 100%
rename from crates/engine/src/commands/time.rs
rename to crates/engine/src/cmd/time.rs
diff --git a/crates/engine/src/commands/timeline.rs b/crates/engine/src/cmd/timeline.rs
similarity index 100%
rename from crates/engine/src/commands/timeline.rs
rename to crates/engine/src/cmd/timeline.rs
diff --git a/crates/engine/src/commands/track.rs b/crates/engine/src/cmd/track.rs
similarity index 100%
rename from crates/engine/src/commands/track.rs
rename to crates/engine/src/cmd/track.rs
diff --git a/crates/engine/src/commands/view.rs b/crates/engine/src/cmd/view.rs
similarity index 100%
rename from crates/engine/src/commands/view.rs
rename to crates/engine/src/cmd/view.rs
diff --git a/crates/engine/src/commands/viewer_cmds.rs b/crates/engine/src/cmd/viewer_cmds.rs
similarity index 100%
rename from crates/engine/src/commands/viewer_cmds.rs
rename to crates/engine/src/cmd/viewer_cmds.rs
diff --git a/crates/engine/src/commands/vpe.rs b/crates/engine/src/cmd/vpe.rs
similarity index 100%
rename from crates/engine/src/commands/vpe.rs
rename to crates/engine/src/cmd/vpe.rs
diff --git a/crates/engine/src/commands/vr_editor.rs b/crates/engine/src/cmd/vr_editor.rs
similarity index 100%
rename from crates/engine/src/commands/vr_editor.rs
rename to crates/engine/src/cmd/vr_editor.rs
diff --git a/crates/engine/src/commands/warp_cmds.rs b/crates/engine/src/cmd/warp_cmds.rs
similarity index 100%
rename from crates/engine/src/commands/warp_cmds.rs
rename to crates/engine/src/cmd/warp_cmds.rs
diff --git a/crates/engine/src/commands/watch_folder.rs b/crates/engine/src/cmd/watch_folder.rs
similarity index 100%
rename from crates/engine/src/commands/watch_folder.rs
rename to crates/engine/src/cmd/watch_folder.rs
diff --git a/crates/engine/src/commands/layer.rs b/crates/engine/src/commands/layer.rs
deleted file mode 100644
index ba4bdfb4a..000000000
--- a/crates/engine/src/commands/layer.rs
+++ /dev/null
@@ -1,2002 +0,0 @@
-//! Layer menu.
-
-use effectcraft_color::{BlendMode, Label};
-use effectcraft_keyframe::{Justify, TextDoc, Value as KV};
-use effectcraft_project::build::{self, Ids};
-use effectcraft_project::{
-    Comp, FootageKind, FrameBlend, GroupKind, ItemId, ItemKind, Layer, LayerId, LayerSource, MaskMode, MatteKind, Node, Project, PropGroup, Quality, Solid,
-    TrackMatte, limits,
-};
-use effectcraft_time::Tick;
-use serde_json::{Value, json};
-
-use super::{CommandSpec, b_p, bad, comp_id, f_p, has_comp, has_layers, layer_mut, layer_p, layers_p, merge_p, resolve_layer, str_p, unlocked};
-use crate::{EngineError, Result, Session, cmd};
-
-pub(crate) fn color_p(p: &Value, k: &str) -> Option<[f32; 3]> {
-    match p.get(k)? {
-        Value::String(s) => effectcraft_color::Rgba::from_hex(s).map(|c| [c.r, c.g, c.b]),
-        Value::Array(a) => {
-            let g = |i: usize| a.get(i).and_then(Value::as_f64).unwrap_or(0.0) as f32;
-            Some([g(0), g(1), g(2)])
-        }
-        _ => None,
-    }
-}
-
-/// Insert a new layer above the selection (or at the top) and select it.
-pub(crate) fn insert_layer(proj: &mut Project, st: &mut crate::EditorState, cid: ItemId, layer: Layer) -> Result<LayerId> {
-    insert_layer_at(proj, st, cid, layer, None)
-}
-
-/// `index`: an `index` parameter, the layer's 1-based place in the stack (1 = top; past the
-/// bottom = the bottom), as 0-based.
-pub(crate) fn index_p(p: &Value, cmd: &str) -> Result<Option<usize>> {
-    match p.get("index") {
-        None | Some(Value::Null) => Ok(None),
-        Some(v) => {
-            v.as_u64().filter(|i| *i >= 1).map(|i| Some(usize::try_from(i - 1).unwrap_or(usize::MAX))).ok_or_else(|| bad(cmd, "index: 1-based stack position"))
-        }
-    }
-}
-
-/// A `position` parameter: `[x, y]` in comp pixels (finite).
-pub(crate) fn position_p(p: &Value, cmd: &str) -> Result<Option<[f64; 2]>> {
-    match p.get("position") {
-        None | Some(Value::Null) => Ok(None),
-        Some(v) => v
-            .as_array()
-            .and_then(|a| Some([a.first()?.as_f64()?, a.get(1)?.as_f64()?]))
-            .filter(|c| c.iter().all(|x| x.is_finite()))
-            .map(Some)
-            .ok_or_else(|| bad(cmd, "position: [x, y] in comp pixels")),
-    }
-}
-
-/// Put a new layer's Position at `pos` (comp pixels).
-pub(crate) fn place(l: &mut Layer, pos: Option<[f64; 2]>) {
-    if let Some([x, y]) = pos
-        && let Some(pr) = l.props.prop_mut("transform/position")
-    {
-        let z = match pr.value {
-            KV::Vec3(v) => v[2],
-            _ => 0.0,
-        };
-        pr.value = KV::Vec3([x, y, z]);
-    }
-}
-
-/// [`insert_layer`] at stack position `at` (0 = top) instead of above the selected layer.
-pub(crate) fn insert_layer_at(proj: &mut Project, st: &mut crate::EditorState, cid: ItemId, mut layer: Layer, at: Option<usize>) -> Result<LayerId> {
-    // Text and shape layers in Advanced 3D comps get Geometry Options (extrusion, bevels).
-    if proj.comp(cid).is_some_and(|c| c.renderer == effectcraft_project::Renderer::Advanced3D) {
-        super::model3d::add_geometry_options(&mut proj.next_id, &mut layer);
-    }
-    let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-    let at = match at {
-        Some(i) => i.min(comp.layers.len()),
-        None => st.selected_layers.first().and_then(|id| comp.layers.iter().position(|l| l.id == *id)).unwrap_or(0),
-    };
-    let id = layer.id;
-    comp.layers.insert(at, layer);
-    st.selected_layers = vec![id];
-    st.selected_props.clear();
-    st.selected_keys.clear();
-    Ok(id)
-}
-
-fn solids_folder(proj: &mut Project) -> ItemId {
-    proj.folder_named("Solids").unwrap_or_else(|| proj.add_item("Solids", Label::Yellow, None, ItemKind::Folder))
-}
-
-fn new_solid_like(s: &mut Session, p: &Value, adjustment: bool) -> Result<Value> {
-    let cid = comp_id(s, p)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
-    let color = color_p(p, "color").unwrap_or(if adjustment { [1.0, 1.0, 1.0] } else { [0.85, 0.2, 0.2] });
-    // 1 to 30,000 px a side (#788): the layer is sized from the same numbers as its solid.
-    let w = p.get("width").and_then(Value::as_u64).map(limits::size).unwrap_or(comp.width);
-    let h = p.get("height").and_then(Value::as_u64).map(limits::size).unwrap_or(comp.height);
-    let pixel_aspect = pixel_aspect_p(p)?.unwrap_or(comp.pixel_aspect);
-    let default_name = if adjustment { "Adjustment Layer 1".to_string() } else { "Solid 1".to_string() };
-    let name = str_p(p, "name").map(str::to_string).unwrap_or(default_name);
-    let id = s.edit(if adjustment { "New Adjustment Layer" } else { "New Solid" }, None, |proj, st| {
-        let folder = solids_folder(proj);
-        let sid = proj.add_item(&name, Label::Red, Some(folder), ItemKind::Solid(Solid { color, width: w, height: h, pixel_aspect }));
-        let mut l = build::layer(proj, &comp, &name, LayerSource::Solid { item: sid }, (w, h), None);
-        if adjustment {
-            l.switches.adjustment = true;
-            l.label = Label::Purple;
-        }
-        insert_layer(proj, st, cid, l)
-    })?;
-    Ok(json!({"layer": id.0}))
-}
-
-/// `pixelAspect` (a positive number), when given.
-fn pixel_aspect_p(p: &Value) -> Result<Option<f64>> {
-    match p.get("pixelAspect").and_then(Value::as_f64) {
-        Some(v) if !(v.is_finite() && v > 0.0) => Err(bad("layer.settings", "`pixelAspect` must be a positive number")),
-        v => Ok(v.map(limits::pixel_aspect)),
-    }
-}
-
-fn new_solid(s: &mut Session, p: &Value) -> Result<Value> {
-    new_solid_like(s, p, false)
-}
-fn new_adjustment(s: &mut Session, p: &Value) -> Result<Value> {
-    new_solid_like(s, p, true)
-}
-
-/// Parameters of `layer.setText` / `layer.newText` that aren't text attributes.
-const NOT_ATTRS: &[&str] = &["layer", "layers", "comp", "merge", "text", "range", "position", "edit"];
-
-/// Apply `layer.setText` keys to `d`: `text` replaces characters `r` (or everything), then each
-/// character / paragraph / document attribute applies to `r` (or everything).
-fn apply_text_params(cmd: &str, p: &Value, d: &mut TextDoc, r: Option<std::ops::Range<usize>>) -> Result<()> {
-    let mut r = r;
-    if let Some(t) = str_p(p, "text") {
-        match r.clone() {
-            Some(rr) => {
-                d.replace_range(rr.clone(), t, None);
-                r = Some(rr.start..rr.start + t.chars().count());
-            }
-            None => d.set_text(t),
-        }
-    }
-    let Some(obj) = p.as_object() else { return Ok(()) };
-    for (k, v) in obj {
-        if NOT_ATTRS.contains(&k.as_str()) {
-            continue;
-        }
-        if !d.set_attr(k, v, r.clone()).map_err(|e| bad(cmd, e))? {
-            return Err(bad(cmd, format!("unknown text attribute {k}")));
-        }
-    }
-    Ok(())
-}
-
-fn text_range_p(p: &Value) -> Option<std::ops::Range<usize>> {
-    let a = p.get("range")?.as_array()?;
-    let g = |i: usize| a.get(i).and_then(Value::as_u64).map(|x| x as usize);
-    let (x, y) = (g(0)?, g(1).or(g(0))?);
-    Some(x.min(y)..x.max(y))
-}
-
-/// `layer.newText`: adds a Text layer to the comp at the CTI and returns `{layer}`.
-///
-/// The document starts as centre-justified "Text", with the optional text parameters applied.
-/// With `box` `[x, y, w, h]`, `(x, y)` is the paragraph box's top-left in comp space. Its width
-/// and height are `w.abs().max(1.0)` and `h.abs().max(1.0)`; the layer position is the box centre.
-/// It is left justified unless `justify` is given. The layer is named by `name`, else the first 40
-/// characters of the first text line, else "Text". `edit: true` also opens a new editing
-/// session with anchor `0` and the caret after the text, selecting all initial text so the next
-/// insertion replaces it. The session has `created: true`, so leaving it empty removes the layer.
-fn new_text(s: &mut Session, p: &Value) -> Result<Value> {
-    let cid = comp_id(s, p)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
-    let mut doc = TextDoc { text: "Text".into(), justify: Justify::Center, ..Default::default() };
-    // A paragraph box given in comp space: the layer sits at its centre.
-    let bx = p.get("box").and_then(Value::as_array).map(|a| [0, 1, 2, 3].map(|i| a.get(i).and_then(Value::as_f64).unwrap_or(0.0)));
-    let mut q = p.clone();
-    if let Some(o) = q.as_object_mut() {
-        o.remove("box");
-        o.remove("name");
-    }
-    let layer_name = str_p(p, "name").map(str::to_string);
-    apply_text_params("layer.newText", &q, &mut doc, None)?;
-    let mut pos = position_p(p, "layer.newText")?;
-    if let Some([x, y, w, h]) = bx {
-        let (w, h) = (w.abs().max(1.0), h.abs().max(1.0));
-        doc.box_size = Some([w, h]);
-        doc.box_pos = [-w / 2.0, -h / 2.0];
-        pos = Some([x + w / 2.0, y + h / 2.0]);
-        if p.get("justify").is_none() {
-            doc.set_attr("justify", &json!("left"), None).map_err(|e| bad("layer.newText", e))?;
-        }
-    }
-    let edit = b_p(p, "edit").unwrap_or(false);
-    let id = s.edit("New Text Layer", None, |proj, st| {
-        let name: String = layer_name.clone().unwrap_or_else(|| doc.text.lines().next().unwrap_or("").chars().take(40).collect());
-        let mut l = build::layer(proj, &comp, if name.is_empty() { "Text" } else { &name }, LayerSource::Text, (comp.width, comp.height), None);
-        if let Some(pr) = l.props.prop_mut("text/sourceText") {
-            pr.value = KV::Text(Box::new(doc.clone()));
-        }
-        if let Some(pos) = pos
-            && let Some(pr) = l.props.prop_mut("transform/position")
-        {
-            pr.value = KV::Vec3([pos[0], pos[1], 0.0]);
-        }
-        let n = doc.char_len();
-        let id = insert_layer(proj, st, cid, l)?;
-        if edit {
-            st.text_edit = Some(super::text_edit::TextEdit {
-                layer: id,
-                anchor: 0,
-                caret: n,
-                created: true,
-                session: super::text_edit::next_edit_session(),
-                ..Default::default()
-            });
-        }
-        Ok(id)
-    })?;
-    Ok(json!({"layer": id.0}))
-}
-
-fn new_shape(s: &mut Session, p: &Value) -> Result<Value> {
-    let cid = comp_id(s, p)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
-    let kind = str_p(p, "kind").unwrap_or("none").to_string();
-    let size = p
-        .get("size")
-        .and_then(Value::as_array)
-        .map(|a| [a.first().and_then(Value::as_f64).unwrap_or(200.0), a.get(1).and_then(Value::as_f64).unwrap_or(200.0)])
-        .unwrap_or([300.0, 300.0]);
-    // A fill, and a stroke only with a width (not the Tools bar's paint).
-    let paint = super::shape_tool::paint_p(p, &Default::default(), "layer.newShape")?;
-    let pos = p
-        .get("position")
-        .and_then(|v| v.as_array())
-        .map(|a| [a.first().and_then(Value::as_f64).unwrap_or(0.0), a.get(1).and_then(Value::as_f64).unwrap_or(0.0)]);
-    let name = str_p(p, "name").unwrap_or("Shape Layer 1").to_string();
-    let id = s.edit("New Shape Layer", None, |proj, st| {
-        let lid = super::shape_tool::new_shape_layer(proj, st, &comp, cid, Some(&name), pos)?;
-        let mut next = proj.next_id;
-        let g = super::shape_tool::shape_group(&mut Ids(&mut next), &kind, size, &paint);
-        proj.next_id = next;
-        if let Some(g) = g {
-            super::shape_tool::add_to_contents(proj, cid, lid, g, [0.0, 0.0], "layer.newShape")?;
-        }
-        Ok(lid)
-    })?;
-    Ok(json!({"layer": id.0}))
-}
-
-fn new_simple(s: &mut Session, p: &Value, src: LayerSource, name: &str, label: &str) -> Result<Value> {
-    let cid = comp_id(s, p)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
-    let name = str_p(p, "name").unwrap_or(name).to_string();
-    let id = s.edit(label, None, |proj, st| {
-        let l = build::layer(proj, &comp, &name, src, (comp.width, comp.height), None);
-        insert_layer(proj, st, cid, l)
-    })?;
-    Ok(json!({"layer": id.0}))
-}
-
-fn new_null(s: &mut Session, p: &Value) -> Result<Value> {
-    new_simple(s, p, LayerSource::Null, "Null 1", "New Null Object")
-}
-
-fn add_item(s: &mut Session, p: &Value) -> Result<Value> {
-    let cid = comp_id(s, p)?;
-    let item = match p.get("item") {
-        Some(Value::Number(n)) => ItemId(n.as_u64().unwrap_or(0)),
-        Some(Value::String(name)) => s.project.find_by_name(name).map(|i| i.id).ok_or_else(|| bad("layer.addItem", format!("no item `{name}`")))?,
-        _ => *s.state.project_selection.first().ok_or_else(|| bad("layer.addItem", "missing `item`"))?,
-    };
-    if s.project.comp_contains(item, cid) {
-        return Err(bad("layer.addItem", "a composition can't contain itself"));
-    }
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
-    let it = s.project.item(item).ok_or_else(|| bad("layer.addItem", "no such item"))?.clone();
-    let (src, size, dur) = match &it.kind {
-        ItemKind::Comp(c) => (LayerSource::Comp { item }, (c.width, c.height), Some(c.duration)),
-        ItemKind::Footage(f) if f.kind == effectcraft_project::FootageKind::Still => {
-            // `duration`, else Settings ▸ Import ▸ Still Footage: length of the composition or a
-            // duration.
-            let d = f_p(p, "duration")
-                .filter(|d| d.is_finite() && *d > 0.0)
-                .or((s.prefs.import.still_footage == "seconds").then_some(s.prefs.import.still_seconds))
-                .map(Tick::from_seconds_f64);
-            (LayerSource::Footage { item }, (f.width, f.height), d)
-        }
-        ItemKind::Footage(f) if f.kind == effectcraft_project::FootageKind::Data => {
-            return Err(bad("layer.addItem", "data files can't be layers; read them in expressions with footage(\"name\").sourceData"));
-        }
-        ItemKind::Footage(f) if f.kind == effectcraft_project::FootageKind::Model => {
-            return super::model3d::new_model(
-                s,
-                &serde_json::json!({"comp": cid.0, "item": item.0, "time": f_p(p, "time"), "index": p.get("index"), "position": p.get("position")}),
-            );
-        }
-        ItemKind::Footage(f) => (LayerSource::Footage { item }, (f.width, f.height), Some(f.looped_duration())),
-        ItemKind::Solid(so) => (LayerSource::Solid { item }, (so.width, so.height), None),
-        ItemKind::Folder => return Err(bad("layer.addItem", "folders can't be layers")),
-    };
-    let index = index_p(p, "layer.addItem")?;
-    let position = position_p(p, "layer.addItem")?;
-    let fr = comp.frame_rate;
-    // Settings ▸ General ▸ Create Layers at Composition Start Time (off: at the current time).
-    let default_start = if s.prefs.general.create_layers_at_comp_start || s.active_comp_id() != Some(cid) { Tick::ZERO } else { s.time() };
-    let start = fr.snap_nearest(f_p(p, "time").map(Tick::from_seconds_f64).unwrap_or(default_start));
-    let id = s.edit("Add Footage to Comp", None, |proj, st| {
-        let mut l = build::layer(proj, &comp, &it.name, src, size, dur);
-        l.start_time = start;
-        l.in_point = start;
-        // Footage and precomps keep their full length past the comp's end (After Effects); items
-        // without a duration (solids, comp-length stills) end with the comp.
-        let end = dur.map_or((start + comp.duration).min(comp.duration), |d| start + d);
-        l.out_point = fr.snap_nearest(end).max(start + fr.frame_duration());
-        place(&mut l, position);
-        insert_layer_at(proj, st, cid, l, index)
-    })?;
-    Ok(json!({"layer": id.0}))
-}
-
-/// A layer whose source is an item (footage, precomposition or solid), as in After Effects'
-/// Replace Source. Text, shape, null, camera, light and 3D model layers have no AVItem source to
-/// replace.
-fn replaceable_layer(l: &Layer) -> bool {
-    matches!(l.source, LayerSource::Footage { .. } | LayerSource::Comp { .. } | LayerSource::Solid { .. })
-}
-
-/// The source a Project item gives a layer, or why it can't replace one.
-fn replacement_source(item: ItemId, it: &effectcraft_project::Item) -> Result<LayerSource> {
-    const CMD: &str = "layer.replaceSource";
-    match &it.kind {
-        ItemKind::Comp(_) => Ok(LayerSource::Comp { item }),
-        ItemKind::Footage(f) if f.kind == FootageKind::Data => {
-            Err(bad(CMD, "data files can't be layer sources; read them in expressions with footage(\"name\").sourceData"))
-        }
-        ItemKind::Footage(f) if f.kind == FootageKind::Model => Err(bad(CMD, "3D model items can't replace a 2D layer source; add them as 3D layers")),
-        ItemKind::Footage(_) => Ok(LayerSource::Footage { item }),
-        ItemKind::Solid(_) => Ok(LayerSource::Solid { item }),
-        ItemKind::Folder => Err(bad(CMD, "folders can't be layer sources")),
-    }
-}
-
-/// Whether a source brings audio properties (precompositions always can; footage when it has an
-/// audio stream).
-fn source_has_audio(project: &Project, source: &LayerSource) -> bool {
-    match source {
-        LayerSource::Comp { .. } => true,
-        LayerSource::Footage { item } => project.item(*item).is_some_and(|i| matches!(&i.kind, ItemKind::Footage(f) if f.has_audio)),
-        _ => false,
-    }
-}
-
-fn has_replace_source(s: &Session) -> std::result::Result<(), String> {
-    has_comp(s)?;
-    let c = s.active_comp().ok_or("no composition")?;
-    if !s.state.selected_layers.iter().filter_map(|l| c.layer(*l)).any(replaceable_layer) {
-        return Err("select a footage, composition or solid layer".into());
-    }
-    if s.state.project_selection.is_empty() {
-        return Err("select a footage item, a composition or a solid in the Project panel".into());
-    }
-    Ok(())
-}
-
-/// Replace the source of the selected (or `layers`) AV layers with a Project item, as After
-/// Effects' Alt-drag and Ctrl+Alt+/ do. The layer keeps every property: name, timing, transforms,
-/// keyframes, expressions, effects, masks, switches, parenting and track matte. Only its source
-/// changes; precompositions bring their Essential Properties group through `sync_project`, and a
-/// source with audio adds an Audio group when the layer has none.
-fn replace_source(s: &mut Session, p: &Value) -> Result<Value> {
-    const CMD: &str = "layer.replaceSource";
-    let (cid, ids) = layers_p(s, p)?;
-    let ids = unlocked(s, cid, ids, CMD)?;
-    if ids.is_empty() {
-        return Err(bad(CMD, "select a layer first"));
-    }
-    let item = match p.get("item") {
-        Some(Value::Number(n)) => ItemId(n.as_u64().ok_or_else(|| bad(CMD, "item: a project item id"))?),
-        Some(Value::String(name)) => s.project.find_by_name(name).map(|i| i.id).ok_or_else(|| bad(CMD, format!("no item `{name}`")))?,
-        _ => *s.state.project_selection.first().ok_or_else(|| bad(CMD, "select a footage item, a composition or a solid in the Project panel"))?,
-    };
-    let it = s.project.item(item).ok_or_else(|| bad(CMD, format!("no item {}", item.0)))?;
-    let source = replacement_source(item, it)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
-    for lid in &ids {
-        let l = comp.layer(*lid).ok_or_else(|| bad(CMD, "no such layer"))?;
-        if !replaceable_layer(l) {
-            return Err(bad(CMD, format!("“{}” has no source item to replace", l.name)));
-        }
-    }
-    if let LayerSource::Comp { item: new } = &source
-        && s.project.comp_contains(*new, cid)
-    {
-        return Err(bad(CMD, "a composition can't contain itself"));
-    }
-    let has_audio = source_has_audio(&s.project, &source);
-    let source_for_edit = source.clone();
-    s.edit("Replace Layer Source", None, |proj, _| {
-        for lid in &ids {
-            let needs_audio = has_audio && proj.comp(cid).and_then(|c| c.layer(*lid)).is_some_and(|l| l.props.sub("audio").is_none());
-            let audio = if needs_audio {
-                let mut next = Ids(&mut proj.next_id);
-                Some(build::audio(&mut next))
-            } else {
-                None
-            };
-            let l = layer_mut(proj, cid, *lid)?;
-            l.source = source_for_edit.clone();
-            if let Some(audio) = audio {
-                l.props.children.push(audio.into());
-            }
-        }
-        Ok(())
-    })?;
-    Ok(json!({"layers": ids.iter().map(|l| l.0).collect::<Vec<_>>(), "item": item.0}))
-}
-
-fn select(s: &mut Session, p: &Value) -> Result<Value> {
-    let cid = comp_id(s, p)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
-    let ids: Vec<LayerId> = match p.get("layers").or(p.get("layer")) {
-        Some(Value::Array(a)) => a.iter().filter_map(|v| resolve_layer(comp, v)).collect(),
-        Some(v) => resolve_layer(comp, v).into_iter().collect(),
-        None => vec![],
-    };
-    let add = b_p(p, "add").unwrap_or(false);
-    let toggle = b_p(p, "toggle").unwrap_or(false);
-    if toggle {
-        for id in ids {
-            if let Some(i) = s.state.selected_layers.iter().position(|l| *l == id) {
-                s.state.selected_layers.remove(i);
-            } else {
-                s.state.selected_layers.push(id);
-            }
-        }
-    } else if add {
-        for id in ids {
-            if !s.state.selected_layers.contains(&id) {
-                s.state.selected_layers.push(id);
-            }
-        }
-    } else {
-        s.state.selected_layers = ids;
-        s.state.selected_props.clear();
-        s.state.selected_keys.clear();
-        let keep = s.state.selected_layers.clone();
-        s.state.selected_vertices.retain(|v| keep.contains(&v.layer));
-    }
-    Ok(json!(s.state.selected_layers.iter().map(|l| l.0).collect::<Vec<_>>()))
-}
-
-fn select_step(s: &mut Session, p: &Value, dir: i64) -> Result<Value> {
-    let comp = s.active_comp().ok_or(EngineError::NoComp)?;
-    if comp.layers.is_empty() {
-        return Ok(Value::Null);
-    }
-    let cur = s.state.selected_layers.first().and_then(|id| comp.layers.iter().position(|l| l.id == *id));
-    let n = comp.layers.len() as i64;
-    // The next layer that can be selected (locked and hidden shy layers are stepped over); at
-    // the end of the stack the selection stays.
-    let start = match cur {
-        Some(i) => i as i64 + dir,
-        None if dir > 0 => 0,
-        None => n - 1,
-    };
-    let next =
-        std::iter::successors(Some(start), |i| Some(i + dir)).take_while(|i| (0..n).contains(i)).find(|i| super::selectable(comp, &comp.layers[*i as usize]));
-    let Some(i) = next.or(cur.map(|i| i as i64)) else { return Ok(Value::Null) };
-    let id = comp.layers[i as usize].id;
-    let add = b_p(p, "add").unwrap_or(false);
-    if add {
-        if !s.state.selected_layers.contains(&id) {
-            s.state.selected_layers.insert(0, id);
-        }
-    } else {
-        s.state.selected_layers = vec![id];
-    }
-    Ok(json!(id.0))
-}
-
-fn select_next(s: &mut Session, p: &Value) -> Result<Value> {
-    select_step(s, p, 1)
-}
-fn select_prev(s: &mut Session, p: &Value) -> Result<Value> {
-    select_step(s, p, -1)
-}
-
-fn set_switch(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, ids) = layers_p(s, p)?;
-    let name = str_p(p, "switch").ok_or_else(|| bad("layer.setSwitch", "missing `switch`"))?.to_string();
-    let v = b_p(p, "value");
-    let label = format!("Layer Switch ({name})");
-    if b_p(p, "others") == Some(true) {
-        return set_switch_others(s, cid, &ids, &name, v, &label);
-    }
-    // `merge`: a switch dragged over several layers in the Timeline is one undo step.
-    let r = s.edit(&label, merge_p(p), |proj, _| {
-        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        let mut last = false;
-        // Toggle relative to the first layer so a multi-selection ends up consistent.
-        let first = comp.layers.iter().find(|l| ids.contains(&l.id)).map(|l| switch_value(l, &name)).unwrap_or(Some(false));
-        let Some(first) = first else { return Err(bad("layer.setSwitch", format!("unknown switch `{name}`"))) };
-        let target = v.unwrap_or(!first);
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
-            set_switch_value(l, &name, target);
-            last = target;
-        }
-        Ok(last)
-    })?;
-    Ok(json!(r))
-}
-
-/// `layer.setSwitch {others: true}` (Alt-click on an A/V feature in the Timeline): the named
-/// layers stand alone, shown / heard / soloed / unlocked while every other layer the switch
-/// applies to is the opposite; when they already do, the other layers come back. `value` sets
-/// the other layers directly.
-fn set_switch_others(s: &mut Session, cid: ItemId, ids: &[LayerId], name: &str, value: Option<bool>, label: &str) -> Result<Value> {
-    let r = s.edit(label, None, |proj, _| {
-        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        // The state that sets a layer apart: unlocked for Lock, on for the rest.
-        let active = !matches!(name, "lock" | "locked");
-        // Track mattes keep their video off by design.
-        let mattes: Vec<LayerId> =
-            if matches!(name, "video" | "eye") { comp.layers.iter().filter_map(|l| l.track_matte.map(|m| m.layer)).collect() } else { Vec::new() };
-        let applies = |l: &Layer| match name {
-            "audio" => l.props.sub("audio").is_some(),
-            "lock" | "locked" => true,
-            // Every layer has a Video switch (it hides a null's outline in the viewer and turns a
-            // camera or light off), as the Timeline's eye cell shows; track mattes keep theirs off
-            // by design.
-            "video" | "eye" => !mattes.contains(&l.id),
-            _ => l.source.is_av() && !mattes.contains(&l.id),
-        };
-        let mut alone = true;
-        for l in comp.layers.iter().filter(|l| applies(l)) {
-            let Some(on) = switch_value(l, name) else { return Err(bad("layer.setSwitch", format!("unknown switch `{name}`"))) };
-            alone &= on == (ids.contains(&l.id) == active);
-        }
-        let others = value.unwrap_or(alone == active);
-        for l in comp.layers.iter_mut().filter(|l| applies(l)) {
-            let v = if ids.contains(&l.id) { active } else { others };
-            set_switch_value(l, name, v);
-        }
-        Ok(others)
-    })?;
-    Ok(json!(r))
-}
-
-fn switch_value(l: &Layer, name: &str) -> Option<bool> {
-    let sw = &l.switches;
-    Some(match name {
-        "video" | "eye" => sw.video,
-        "audio" => sw.audio,
-        "solo" => sw.solo,
-        "lock" | "locked" => sw.locked,
-        "shy" => sw.shy,
-        "collapse" => sw.collapse,
-        "quality" => sw.quality == Quality::Best,
-        "fx" | "effects" => sw.effects,
-        "frameBlend" => sw.frame_blend != FrameBlend::Off,
-        "motionBlur" => sw.motion_blur,
-        "adjustment" => sw.adjustment,
-        "threeD" | "3d" | "3D" => sw.three_d,
-        "guide" => sw.guide,
-        "preserveTransparency" => l.preserve_transparency,
-        _ => return None,
-    })
-}
-
-fn set_switch_value(l: &mut Layer, name: &str, v: bool) {
-    let sw = &mut l.switches;
-    match name {
-        "video" | "eye" => sw.video = v,
-        "audio" => sw.audio = v,
-        "solo" => sw.solo = v,
-        "lock" | "locked" => sw.locked = v,
-        "shy" => sw.shy = v,
-        "collapse" => sw.collapse = v,
-        "quality" => sw.quality = if v { Quality::Best } else { Quality::Draft },
-        "fx" | "effects" => sw.effects = v,
-        "frameBlend" => sw.frame_blend = if v { FrameBlend::FrameMix } else { FrameBlend::Off },
-        "motionBlur" => sw.motion_blur = v,
-        "adjustment" => sw.adjustment = v,
-        "threeD" | "3d" | "3D" => {
-            if sw.three_d && !v {
-                drop_3d_values(l);
-            }
-            l.switches.three_d = v;
-        }
-        "guide" => sw.guide = v,
-        "preserveTransparency" => l.preserve_transparency = v,
-        _ => {}
-    }
-}
-
-/// Turning the 3D switch off discards Z values, Orientation and X/Y Rotation (as in AE).
-fn drop_3d_values(l: &mut Layer) {
-    let Some(tr) = l.transform_mut() else { return };
-    for (m, keep) in [("position", 0.0), ("anchor", 0.0), ("scale", 100.0)] {
-        if let Some(pr) = tr.get_mut(m) {
-            let flat = |v: &mut KV| {
-                if let KV::Vec3(a) = v {
-                    a[2] = keep;
-                }
-            };
-            flat(&mut pr.value);
-            for k in &mut pr.keys {
-                flat(&mut k.value);
-            }
-        }
-    }
-    for (m, zero) in [("orientation", KV::Vec3([0.0; 3])), ("rotationX", KV::Scalar(0.0)), ("rotationY", KV::Scalar(0.0))] {
-        if let Some(pr) = tr.get_mut(m) {
-            pr.keys.clear();
-            pr.expr = None;
-            pr.value = zero;
-        }
-    }
-}
-
-fn rename(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, lid) = layer_p(s, p, "layer.rename")?;
-    let name = str_p(p, "name").ok_or_else(|| bad("layer.rename", "missing `name`"))?.to_string();
-    s.edit("Rename Layer", None, |proj, _| {
-        layer_mut(proj, cid, lid)?.name = name.clone();
-        Ok(())
-    })?;
-    Ok(Value::Null)
-}
-
-/// The Timeline's Comment column.
-fn set_comment(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, ids) = layers_p(s, p)?;
-    let text = str_p(p, "comment").ok_or_else(|| bad("layer.setComment", "missing `comment`"))?.to_string();
-    s.edit("Layer Comment", None, |proj, _| {
-        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
-            l.comment = text.clone();
-        }
-        Ok(())
-    })?;
-    Ok(Value::Null)
-}
-
-fn blend(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, ids) = layers_p(s, p)?;
-    let mode = str_p(p, "mode").and_then(BlendMode::from_name);
-    let step = p.get("step").and_then(Value::as_i64).unwrap_or(0);
-    if mode.is_none() && step == 0 {
-        return Err(bad("layer.setBlendMode", "need `mode` (e.g. Multiply) or `step` ±1"));
-    }
-    s.edit("Blending Mode", None, |proj, _| {
-        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
-            l.blend_mode = match mode {
-                Some(m) => m,
-                None if step > 0 => l.blend_mode.next(),
-                None => l.blend_mode.previous(),
-            };
-        }
-        Ok(())
-    })?;
-    Ok(Value::Null)
-}
-
-fn track_matte(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, lid) = layer_p(s, p, "layer.setTrackMatte")?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
-    let matte = match p.get("matte") {
-        None | Some(Value::Null) => None,
-        Some(v) => Some(resolve_layer(comp, v).ok_or_else(|| bad("layer.setTrackMatte", "no such matte layer"))?),
-    };
-    let kind = str_p(p, "kind")
-        .map(|k| match k.to_ascii_lowercase().replace([' ', '_', '-'], "").as_str() {
-            "alphainverted" | "alphainv" => MatteKind::AlphaInverted,
-            "luma" => MatteKind::Luma,
-            "lumainverted" | "lumainv" => MatteKind::LumaInverted,
-            _ => MatteKind::Alpha,
-        })
-        .unwrap_or(MatteKind::Alpha);
-    s.edit("Track Matte", None, |proj, _| {
-        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        if let Some(m) = matte {
-            if m == lid {
-                return Err(bad("layer.setTrackMatte", "a layer can't be its own matte"));
-            }
-            if let Some(ml) = comp.layer_mut(m) {
-                ml.switches.video = false;
-            }
-        }
-        comp.layer_mut(lid).ok_or(EngineError::NoComp)?.track_matte = matte.map(|layer| TrackMatte { layer, kind });
-        Ok(())
-    })?;
-    Ok(Value::Null)
-}
-
-/// Re-express a layer in its new parent space without moving its anchor.
-pub(crate) struct ParentFix {
-    pub layer: LayerId,
-    /// Maps Position from the old parent's space into the new one's.
-    m: effectcraft_geom::Mat3,
-    /// Added to Rotation.
-    rotation: f64,
-    /// Multiply Scale.
-    scale: [f64; 2],
-    /// 3D AV layers retain their world-space anchor, including Z.
-    position_3d: Option<effectcraft_geom::Mat4>,
-    /// A uniform relative parent transform can preserve static Orientation and Scale.
-    pose_3d: Option<([f64; 3], f64)>,
-}
-
-impl ParentFix {
-    /// Re-express the layer's Position, Rotation and Scale (every key) in the new parent's space.
-    pub fn apply(&self, l: &mut Layer) {
-        let Some(tr) = l.props.sub_mut("transform") else { return };
-        if let Some(m) = self.position_3d {
-            // Spatial Position speed measures distance along its path. Its parent-space
-            // unit changes even when the child's Orientation cannot be re-expressed.
-            let position_speed = uniform_parent_pose(m, [0.0; 3]).map(|(_, factor)| factor.abs());
-            let map_position = |v: &KV| {
-                let q = m.apply(effectcraft_geom::Vec3::from(v.as_vec3()));
-                KV::Vec3([q.x, q.y, q.z])
-            };
-            // Read all separated axes before writing any of them.
-            let names = ["positionX", "positionY", "positionZ"];
-            if tr.get("positionX").is_some() {
-                let axes = names.map(|name| tr.get(name).cloned());
-                let current = axes.each_ref().map(|pr| pr.as_ref().map(|pr| pr.value.as_f64()).unwrap_or(0.0));
-                let q = m.apply(effectcraft_geom::Vec3::from(current));
-                for (i, name) in names.into_iter().enumerate() {
-                    if let Some(pr) = tr.get_mut(name) {
-                        pr.value = KV::Scalar([q.x, q.y, q.z].get(i).copied().unwrap_or(0.0));
-                        for key in &mut pr.keys {
-                            let p = axes.each_ref().map(|axis| axis.as_ref().map(|axis| axis.value_at(key.time).as_f64()).unwrap_or(0.0));
-                            let q = m.apply(effectcraft_geom::Vec3::from(p));
-                            key.value = KV::Scalar([q.x, q.y, q.z].get(i).copied().unwrap_or(0.0));
-                        }
-                    }
-                }
-            }
-            if let Some(pr) = tr.get_mut("position") {
-                pr.value = map_position(&pr.value);
-                for key in &mut pr.keys {
-                    key.value = map_position(&key.value);
-                    // Spatial tangents are vectors, so the parent's translation is excluded.
-                    for tangent in [&mut key.spatial_in, &mut key.spatial_out] {
-                        let v = m.apply_vec(effectcraft_geom::Vec3::from(*tangent));
-                        *tangent = [v.x, v.y, v.z];
-                    }
-                }
-                if let Some(factor) = position_speed
-                    .filter(|_| pr.spatial)
-                    .filter(|factor| pr.keys.iter().flat_map(|key| key.in_ease.iter().chain(&key.out_ease)).all(|ease| (ease.speed * *factor).is_finite()))
-                {
-                    for key in &mut pr.keys {
-                        for ease in key.in_ease.iter_mut().chain(&mut key.out_ease) {
-                            ease.speed *= factor;
-                        }
-                    }
-                }
-            }
-            // Cameras and lights aim with Point of Interest: move it by the same parent-space
-            // change, so a two-node rig keeps its world frame (#1010, #1020).
-            if let Some(pr) = tr.get_mut("poi") {
-                pr.value = map_position(&pr.value);
-                for key in &mut pr.keys {
-                    key.value = map_position(&key.value);
-                    for tangent in [&mut key.spatial_in, &mut key.spatial_out] {
-                        let v = m.apply_vec(effectcraft_geom::Vec3::from(*tangent));
-                        *tangent = [v.x, v.y, v.z];
-                    }
-                }
-                if let Some(factor) = position_speed
-                    .filter(|_| pr.spatial)
-                    .filter(|factor| pr.keys.iter().flat_map(|key| key.in_ease.iter().chain(&key.out_ease)).all(|ease| (ease.speed * *factor).is_finite()))
-                {
-                    for key in &mut pr.keys {
-                        for ease in key.in_ease.iter_mut().chain(&mut key.out_ease) {
-                            ease.speed *= factor;
-                        }
-                    }
-                }
-            }
-            if let Some((orientation, factor)) = self.pose_3d {
-                if let Some(pr) = tr.get_mut("orientation") {
-                    pr.value = KV::Vec3(orientation);
-                }
-                if let Some(pr) = tr.get_mut("scale") {
-                    let scaled = |value: &KV| KV::Vec3(value.as_vec3().map(|v| v * factor));
-                    pr.value = scaled(&pr.value);
-                    for key in &mut pr.keys {
-                        key.value = scaled(&key.value);
-                        // Scale's temporal speeds use the same units as its values.
-                        for ease in key.in_ease.iter_mut().chain(&mut key.out_ease) {
-                            ease.speed *= factor;
-                        }
-                    }
-                }
-            }
-            return;
-        }
-        let map = |pr: &mut effectcraft_project::Property, f: &dyn Fn(&KV) -> KV| {
-            pr.value = f(&pr.value);
-            for key in &mut pr.keys {
-                key.value = f(&key.value);
-            }
-        };
-        let m = self.m;
-        if tr.get("positionX").is_some() {
-            // Separated dimensions: X and Y move together, key by key at the same times.
-            // Everything is read before anything is written.
-            let [x, y] = [tr.get("positionX"), tr.get("positionY")].map(|p| p.map(|p| p.value.as_f64()).unwrap_or(0.0));
-            let q = m.apply(effectcraft_geom::vec2(x, y));
-            let keys_x: Vec<(Tick, f64)> = tr.get("positionX").map(|p| p.keys.iter().map(|k| (k.time, k.value.as_f64())).collect()).unwrap_or_default();
-            let keys_y: Vec<(Tick, f64)> = tr.get("positionY").map(|p| p.keys.iter().map(|k| (k.time, k.value.as_f64())).collect()).unwrap_or_default();
-            let at = |keys: &[(Tick, f64)], name: &str, t: Tick, tr: &PropGroup| {
-                keys.iter().find(|k| k.0 == t).map(|k| k.1).unwrap_or_else(|| tr.get(name).map(|p| p.value_at(t).as_f64()).unwrap_or(0.0))
-            };
-            let (xs, ys): (Vec<f64>, Vec<f64>) = (
-                keys_x.iter().map(|&(t, x)| m.apply(effectcraft_geom::vec2(x, at(&keys_y, "positionY", t, tr))).x).collect(),
-                keys_y.iter().map(|&(t, y)| m.apply(effectcraft_geom::vec2(at(&keys_x, "positionX", t, tr), y)).y).collect(),
-            );
-            for (name, value, vals) in [("positionX", q.x, xs), ("positionY", q.y, ys)] {
-                if let Some(pr) = tr.get_mut(name) {
-                    pr.value = KV::Scalar(value);
-                    for (k, v) in pr.keys.iter_mut().zip(vals) {
-                        k.value = KV::Scalar(v);
-                    }
-                }
-            }
-        } else if let Some(pr) = tr.get_mut("position") {
-            map(pr, &|v| {
-                let c = v.as_vec3();
-                let q = m.apply(effectcraft_geom::vec2(c[0], c[1]));
-                KV::Vec3([q.x, q.y, c[2]])
-            });
-        }
-        let (dr, k) = (self.rotation, self.scale);
-        if let Some(pr) = tr.get_mut("rotation") {
-            map(pr, &|v| KV::Scalar(v.as_f64() + dr));
-        }
-        if let Some(pr) = tr.get_mut("scale") {
-            map(pr, &|v| {
-                let c = v.as_vec3();
-                KV::Vec3([c[0] * k[0], c[1] * k[1], c[2]])
-            });
-        }
-    }
-}
-
-/// A uniform factor commutes with authored axis Rotation and Scale; prepend its orthogonal
-/// rotation to static Orientation using the existing Rz * Ry * Rx order.
-fn uniform_parent_pose(m: effectcraft_geom::Mat4, orientation: [f64; 3]) -> Option<([f64; 3], f64)> {
-    use effectcraft_geom::{Mat4, Vec3, vec3};
-    if !orientation.iter().all(|v| v.is_finite()) {
-        return None;
-    }
-    let a = m.0;
-    let columns = [vec3(a[0][0], a[1][0], a[2][0]), vec3(a[0][1], a[1][1], a[2][1]), vec3(a[0][2], a[1][2], a[2][2])];
-    let magnitude = columns[0].x.hypot(columns[0].y).hypot(columns[0].z);
-    if !magnitude.is_finite() || magnitude <= 0.0 {
-        return None;
-    }
-    let c = columns.map(|c| c / magnitude);
-    if c.iter().any(|c| (c.dot(*c) - 1.0).abs() > 1e-9) || c[0].dot(c[1]).abs() > 1e-9 || c[0].dot(c[2]).abs() > 1e-9 || c[1].dot(c[2]).abs() > 1e-9 {
-        return None;
-    }
-    let cross = vec3(c[1].y * c[2].z - c[1].z * c[2].y, c[1].z * c[2].x - c[1].x * c[2].z, c[1].x * c[2].y - c[1].y * c[2].x);
-    let factor = if c[0].dot(cross) < 0.0 { -magnitude } else { magnitude };
-    let mut rotation = Mat4::IDENTITY;
-    for row in 0..3 {
-        for col in 0..3 {
-            rotation.0[row][col] = a[row][col] / factor;
-        }
-    }
-    if (0..3).all(|row| (0..3).all(|col| (rotation.0[row][col] - if row == col { 1.0 } else { 0.0 }).abs() < 1e-12)) {
-        return Some((orientation, factor));
-    }
-    let r = (rotation * Mat4::orientation(Vec3::from(orientation))).0;
-    // atan2 rather than asin: near ±90 degrees asin loses precision, while cos(y) stays exact.
-    let cy = r[0][0].hypot(r[1][0]);
-    let y = (-r[2][0]).atan2(cy);
-    let (x, z) = if cy > 1e-9 { (r[2][1].atan2(r[2][2]), r[1][0].atan2(r[0][0])) } else { ((-r[1][2]).atan2(r[1][1]), 0.0) };
-    Some(([x.to_degrees(), y.to_degrees(), z.to_degrees()], factor))
-}
-
-/// A parent change retains 2D transforms and the world-space anchor of 3D layers (Position,
-/// and Point of Interest for two-node cameras and lights). Position is
-/// re-expressed in the new parent's space (`None`: the composition), evaluated at the current
-/// time.
-pub(crate) fn parent_fixes(s: &Session, cid: ItemId, ids: &[LayerId], parent: Option<LayerId>) -> Vec<ParentFix> {
-    let Some(comp) = s.project.comp(cid) else { return vec![] };
-    let ectx =
-        effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time: s.time(), expr: s.expr.as_deref(), footage: Some(s.footage.as_ref()) };
-    let space = |id: Option<LayerId>| -> effectcraft_geom::Mat3 {
-        id.and_then(|i| comp.layer(i)).filter(|l| !l.is_3d()).map(|l| ectx.layer_to_comp(l).0).unwrap_or(effectcraft_geom::Mat3::IDENTITY)
-    };
-    let decompose = |m: &effectcraft_geom::Mat3| {
-        let a = m.0;
-        let sx = (a[0][0] * a[0][0] + a[1][0] * a[1][0]).sqrt();
-        let det = a[0][0] * a[1][1] - a[0][1] * a[1][0];
-        (a[1][0].atan2(a[0][0]).to_degrees(), sx, if sx > 1e-12 { det / sx } else { 0.0 })
-    };
-    let new_m = space(parent);
-    let Some(inv) = new_m.inverse() else { return vec![] };
-    let (rn, sxn, syn) = decompose(&new_m);
-    let mut fixes: Vec<_> = comp
-        .layers
-        .iter()
-        .filter(|l| ids.contains(&l.id) && !l.is_3d() && l.parent != parent)
-        .map(|l| {
-            let old_m = space(l.parent);
-            let (ro, sxo, syo) = decompose(&old_m);
-            let scale = [if sxn.abs() > 1e-12 { sxo / sxn } else { 1.0 }, if syn.abs() > 1e-12 { syo / syn } else { 1.0 }];
-            ParentFix { layer: l.id, m: inv * old_m, rotation: ro - rn, scale, position_3d: None, pose_3d: None }
-        })
-        .collect();
-    let space_3d = |id: Option<LayerId>| {
-        id.and_then(|id| comp.layer(id)).map_or(effectcraft_geom::Mat4::IDENTITY, |layer| {
-            // Parent transforms do not inherit the parent's source pixel-aspect stretch.
-            let world = ectx.world_matrix(layer);
-            let par = ectx.par_ratio(layer);
-            let a = layer.transform().map(|tr| ectx.v3(layer, tr, "anchor", [0.0; 3])).unwrap_or([0.0; 3]);
-            let anchor = effectcraft_geom::vec3(a[0], a[1], if layer.is_3d() { a[2] } else { 0.0 });
-            world
-                * effectcraft_geom::Mat4::translate(anchor)
-                * effectcraft_geom::Mat4::scale(effectcraft_geom::vec3(1.0 / par, 1.0, 1.0))
-                * effectcraft_geom::Mat4::translate(-anchor)
-        })
-    };
-    if let Some(inv) = space_3d(parent).inverse().filter(|m| m.0.iter().flatten().all(|v| v.is_finite())) {
-        // Cameras and lights compensate like 3D layers (Position, and Point of Interest for
-        // two-node rigs), so parenting keeps the world frame (#1010, #1020). They have no
-        // Scale, so `pose_3d` below stays `None` and Orientation is kept as authored.
-        for layer in comp.layers.iter().filter(|l| ids.contains(&l.id) && l.is_3d() && l.parent != parent) {
-            let m = inv * space_3d(layer.parent);
-            if m.0.iter().flatten().all(|v| v.is_finite()) {
-                let pose_3d = layer.transform().and_then(|tr| {
-                    let orientation = tr.get("orientation")?;
-                    let scale = tr.get("scale")?;
-                    // Animated Euler Orientation and auto-orient cannot be re-expressed by
-                    // prepending a constant Euler value. Expression-driven values stay authored.
-                    if !orientation.keys.is_empty()
-                        || orientation.expr.is_some()
-                        || scale.expr.is_some()
-                        || layer.auto_orient != effectcraft_project::AutoOrient::Off
-                    {
-                        return None;
-                    }
-                    let pose = uniform_parent_pose(m, orientation.value.as_vec3())?;
-                    let factor = pose.1;
-                    let values_finite = std::iter::once(&scale.value)
-                        .chain(scale.keys.iter().map(|key| &key.value))
-                        .all(|value| value.as_vec3().iter().all(|v| (v * factor).is_finite()));
-                    let speeds_finite = scale.keys.iter().flat_map(|key| key.in_ease.iter().chain(&key.out_ease)).all(|ease| (ease.speed * factor).is_finite());
-                    (values_finite && speeds_finite).then_some(pose)
-                });
-                fixes.push(ParentFix { layer: layer.id, m: effectcraft_geom::Mat3::IDENTITY, rotation: 0.0, scale: [1.0; 2], position_3d: Some(m), pose_3d });
-            }
-        }
-    }
-    fixes
-}
-
-/// Validate the proposed ancestor chain before any authored edit, including when compensation
-/// is disabled. Bound both unique ancestors and linear lookup/selection work on loaded graphs.
-fn check_parent_chain(comp: &Comp, ids: &[LayerId], parent: Option<LayerId>, max_visits: usize, max_work: usize) -> Result<()> {
-    let mut seen = std::collections::HashSet::new();
-    let mut work = 0usize;
-    let mut cur = parent;
-    while let Some(id) = cur {
-        if seen.len() >= max_visits {
-            return Err(bad("layer.setParent", "parent chain exceeds the safety visit limit"));
-        }
-        if !seen.insert(id) {
-            return Err(bad("layer.setParent", "parent chain contains an existing cycle"));
-        }
-        for selected in ids {
-            if work >= max_work {
-                return Err(bad("layer.setParent", "parent chain exceeds the safety work limit"));
-            }
-            work += 1;
-            if *selected == id {
-                return Err(bad("layer.setParent", "parenting would create a cycle"));
-            }
-        }
-        let mut ancestor = None;
-        for layer in &comp.layers {
-            if work >= max_work {
-                return Err(bad("layer.setParent", "parent chain exceeds the safety work limit"));
-            }
-            work += 1;
-            if layer.id == id {
-                ancestor = Some(layer);
-                break;
-            }
-        }
-        let layer = ancestor.ok_or_else(|| bad("layer.setParent", "parent chain refers to a missing layer"))?;
-        cur = layer.parent;
-    }
-    Ok(())
-}
-
-fn set_parent(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, ids) = layers_p(s, p)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
-    let parent = match p.get("parent") {
-        None | Some(Value::Null) => None,
-        Some(v) => Some(resolve_layer(comp, v).ok_or_else(|| bad("layer.setParent", "no such parent layer"))?),
-    };
-    // A loaded cycle need not include a selected child. Validate before compensation or edit;
-    // do not impose the renderer's 64-ancestor truncation as a new ordinary hierarchy limit.
-    check_parent_chain(comp, &ids, parent, 4096, 1_048_576)?;
-    // Like AE's pick-whip, parenting keeps the layer where it is: its transform is re-expressed
-    // in the new parent's space (Position, Rotation, Scale), unless `compensate: false`.
-    let compensate = b_p(p, "compensate").unwrap_or(true);
-    let fixes = if compensate { parent_fixes(s, cid, &ids, parent) } else { vec![] };
-    s.edit("Parent", None, |proj, _| {
-        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
-            l.parent = parent;
-            if let Some(f) = fixes.iter().find(|f| f.layer == l.id) {
-                f.apply(l);
-            }
-        }
-        Ok(())
-    })?;
-    Ok(Value::Null)
-}
-
-fn timing(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, ids) = layers_p(s, p)?;
-    let t = s.time();
-    let op = str_p(p, "op").unwrap_or("set").to_string();
-    // Layer times stay on frame boundaries of the comp (as in AE).
-    let fr = s.project.comp(cid).ok_or(EngineError::NoComp)?.frame_rate;
-    let snap = |k: &str| f_p(p, k).map(|v| fr.snap_nearest(Tick::from_seconds_f64(v)));
-    let (delta, start, inp, outp) = (snap("delta"), snap("start"), snap("in"), snap("out"));
-    // Relative trims: each layer moves its own in/out point by the same amount, so dragging an
-    // edge of several selected layers trims them all together (as in AE).
-    let (in_delta, out_delta) = (snap("inDelta"), snap("outDelta"));
-    s.edit("Layer Timing", merge_p(p), |proj, _| {
-        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        let fd = comp.frame_duration();
-        let comp_dur = comp.duration;
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
-            let shift = |l: &mut Layer, d: Tick| {
-                l.start_time += d;
-                l.in_point += d;
-                l.out_point += d;
-            };
-            match op.as_str() {
-                "moveInToTime" => {
-                    let d = t - l.in_point;
-                    shift(l, d);
-                }
-                "moveOutToTime" => {
-                    let d = t - l.out_point;
-                    shift(l, d);
-                }
-                "moveInToStart" => {
-                    let d = Tick::ZERO - l.in_point;
-                    shift(l, d);
-                }
-                "moveOutToEnd" => {
-                    let d = comp_dur - l.out_point;
-                    shift(l, d);
-                }
-                "trimInToTime" => l.in_point = t.min(l.out_point - fd),
-                "trimOutToTime" => l.out_point = t.max(l.in_point + fd),
-                _ => {
-                    if let Some(d) = delta {
-                        shift(l, d);
-                    }
-                    if let Some(st) = start {
-                        let d = st - l.start_time;
-                        shift(l, d);
-                    }
-                    if let Some(i) = inp {
-                        l.in_point = i.min(l.out_point - fd);
-                    }
-                    if let Some(o) = outp {
-                        l.out_point = o.max(l.in_point + fd);
-                    }
-                    // Stops at the comp start/end (a point already past it doesn't jump onto
-                    // it), keeping at least one frame of layer.
-                    if let Some(d) = in_delta {
-                        l.in_point = (l.in_point + d).max(Tick::ZERO.min(l.in_point)).min(l.out_point - fd);
-                    }
-                    if let Some(d) = out_delta {
-                        l.out_point = (l.out_point + d).min(comp_dur.max(l.out_point)).max(l.in_point + fd);
-                    }
-                }
-            }
-        }
-        Ok(())
-    })?;
-    Ok(Value::Null)
-}
-
-/// `p` with `key` set.
-fn with(p: &Value, key: &str, v: Value) -> Value {
-    let mut p = if p.is_object() { p.clone() } else { json!({}) };
-    p[key] = v;
-    p
-}
-
-/// Move the layers `frames` frames in time (Alt+Page Up / Page Down, with Shift ten frames).
-fn move_frames(s: &mut Session, p: &Value, frames: i64) -> Result<Value> {
-    let (cid, _) = layers_p(s, p)?;
-    let delta = s.project.comp(cid).ok_or(EngineError::NoComp)?.frame_rate.tick_of(frames).seconds();
-    timing(s, &with(p, "delta", json!(delta)))
-}
-
-/// Slip edit: move a layer's source (footage or precomp) under its fixed in and out points, like
-/// dragging the source-duration bar in After Effects. `delta` in seconds or `frames`; positive
-/// moves the source later. Clamped so the source still covers the in–out span. Keyframes and
-/// layer markers are in layer time, so they travel with the source.
-fn slip(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, ids) = layers_p(s, p)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
-    let fr = comp.frame_rate;
-    let delta = match (p.get("frames").and_then(Value::as_i64), f_p(p, "delta")) {
-        (Some(f), _) => fr.tick_of(f),
-        (None, Some(d)) => fr.snap_nearest(Tick::from_seconds_f64(d)),
-        _ => return Err(bad("layer.slip", "delta (seconds) or frames required")),
-    };
-    // Allowed shift per layer: the source span [lo, hi] in comp time must keep covering in..out.
-    let mut shifts: Vec<(LayerId, Tick)> = Vec::new();
-    for l in comp.layers.iter().filter(|l| ids.contains(&l.id)) {
-        if l.props.get("timeRemap").is_some() {
-            continue;
-        }
-        let dur = match &l.source {
-            LayerSource::Footage { item } => match s.project.item(*item).map(|i| &i.kind) {
-                Some(ItemKind::Footage(f)) if f.kind != effectcraft_project::FootageKind::Still => Some(f.looped_duration()),
-                _ => None,
-            },
-            LayerSource::Comp { item } => s.project.comp(*item).map(|c| c.duration),
-            _ => None,
-        };
-        let Some(dur) = dur else { continue };
-        let (a, b) = (l.comp_time(Tick::ZERO), l.comp_time(dur));
-        let (lo, hi) = (a.min(b), a.max(b));
-        let (min_d, max_d) = (l.out_point - hi, l.in_point - lo);
-        if min_d > max_d {
-            continue;
-        }
-        shifts.push((l.id, delta.max(min_d).min(max_d)));
-    }
-    if shifts.is_empty() {
-        return Err(bad("layer.slip", "select a footage or precomp layer (without time remapping)"));
-    }
-    s.edit("Slip Edit", merge_p(p), |proj, _| {
-        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        for (id, d) in &shifts {
-            if let Some(l) = comp.layer_mut(*id) {
-                l.start_time += *d;
-            }
-        }
-        Ok(())
-    })?;
-    Ok(json!({"slipped": shifts.iter().map(|(id, d)| json!({"layer": id.0, "delta": d.seconds()})).collect::<Vec<_>>()}))
-}
-
-fn arrange(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, ids) = layers_p(s, p)?;
-    let ids = unlocked(s, cid, ids, "layer.arrange")?;
-    let how = str_p(p, "to").unwrap_or("front").to_string();
-    let index = p.get("index").and_then(Value::as_u64).map(|i| i as usize);
-    // `above`: put the layers right above that one (the timeline's drag to reorder).
-    let above = match p.get("above") {
-        Some(v) => {
-            let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
-            let a = resolve_layer(comp, v).ok_or_else(|| bad("layer.arrange", "no such layer for `above`"))?;
-            if ids.contains(&a) {
-                return Err(bad("layer.arrange", "`above` must be a layer that isn't being moved"));
-            }
-            Some(a)
-        }
-        None => None,
-    };
-    s.edit("Arrange Layers", None, |proj, _| {
-        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        // Bring Forward / Send Backward move each layer one step past the next layer that isn't
-        // moving (a run of selected layers moves as one; one already at the end stays).
-        if above.is_none() && index.is_none() && matches!(how.as_str(), "forward" | "backward") {
-            let picked = |l: &Layer| ids.contains(&l.id);
-            let n = comp.layers.len();
-            if how == "forward" {
-                for i in 1..n {
-                    if picked(&comp.layers[i]) && !picked(&comp.layers[i - 1]) {
-                        let run_end = (i..n).find(|j| !picked(&comp.layers[*j])).unwrap_or(n);
-                        comp.layers[i - 1..run_end].rotate_left(1);
-                    }
-                }
-            } else {
-                for i in (0..n.saturating_sub(1)).rev() {
-                    if picked(&comp.layers[i]) && !picked(&comp.layers[i + 1]) {
-                        let run_start = (0..=i).rev().find(|j| !picked(&comp.layers[*j])).map_or(0, |j| j + 1);
-                        comp.layers[run_start..=i + 1].rotate_right(1);
-                    }
-                }
-            }
-            return Ok(());
-        }
-        let mut picked: Vec<Layer> = Vec::new();
-        comp.layers.retain(|l| {
-            if ids.contains(&l.id) {
-                picked.push(l.clone());
-                false
-            } else {
-                true
-            }
-        });
-        let at = match (how.as_str(), index) {
-            _ if above.is_some() => comp.layers.iter().position(|l| Some(l.id) == above).unwrap_or(comp.layers.len()),
-            (_, Some(i)) => i.saturating_sub(1).min(comp.layers.len()),
-            ("back", _) => comp.layers.len(),
-            _ => 0,
-        };
-        for (k, l) in picked.into_iter().enumerate() {
-            comp.layers.insert((at + k).min(comp.layers.len()), l);
-        }
-        Ok(())
-    })?;
-    Ok(Value::Null)
-}
-
-/// Layer ▸ Pre-compose. `mode: move` (default; "Move all attributes into the new composition")
-/// nests the selected layers as they are; `mode: leave` ("Leave all attributes in", one footage,
-/// solid or precomp layer) nests only the layer's source, sized to it, and keeps the layer's
-/// transform, masks, effects and timing in the current comp. `adjustDuration` (move) trims the
-/// new comp to the selected layers' span; `open` opens the new comp.
-fn precompose(s: &mut Session, p: &Value) -> Result<Value> {
-    let c = "layer.precompose";
-    let (cid, ids) = layers_p(s, p)?;
-    if ids.is_empty() {
-        return Err(bad(c, "no layers"));
-    }
-    let name = str_p(p, "name").unwrap_or("Pre-comp 1").to_string();
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
-    let leave = match str_p(p, "mode").unwrap_or("move") {
-        "move" => false,
-        "leave" => true,
-        x => return Err(bad(c, format!("mode: move|leave, got `{x}`"))),
-    };
-    let adjust = b_p(p, "adjustDuration").unwrap_or(false);
-    if leave {
-        let [lid] = ids[..] else { return Err(bad(c, "\"Leave all attributes\" needs exactly one layer")) };
-        let layer = comp.layer(lid).ok_or(EngineError::NoComp)?.clone();
-        let Some(src_item) = layer.source.item() else {
-            return Err(bad(c, "\"Leave all attributes\" is available for footage, solid and precomp layers only"));
-        };
-        let (w, h) = effectcraft_render::source_size(&s.project, &layer);
-        let (w, h) = if w == 0 || h == 0 { (comp.width, comp.height) } else { (w, h) };
-        let dur = match s.project.item(src_item).map(|i| &i.kind) {
-            Some(ItemKind::Comp(nc)) => nc.duration,
-            Some(ItemKind::Footage(f)) if f.duration > Tick(0) => f.duration,
-            _ => comp.duration,
-        };
-        let new = s.edit("Pre-compose", None, |proj, st| {
-            let mut inner = comp.nested_like(w, h, dur);
-            let mut il = build::layer(proj, &inner, &layer.name, layer.source.clone(), (w, h), Some(dur));
-            il.name = layer.name.clone();
-            inner.layers.push(il);
-            let iid = proj.add_item(&name, Label::Sandstone, None, ItemKind::Comp(inner.into()));
-            let l = layer_mut(proj, cid, lid)?;
-            l.source = LayerSource::Comp { item: iid };
-            l.name = name.clone();
-            st.selected_layers = vec![lid];
-            Ok((iid, lid))
-        })?;
-        if b_p(p, "open").unwrap_or(false) {
-            s.open_comp(new.0);
-        }
-        return Ok(json!({"comp": new.0.0, "layer": new.1.0}));
-    }
-    let span = {
-        let sel: Vec<&effectcraft_project::Layer> = comp.layers.iter().filter(|l| ids.contains(&l.id)).collect();
-        let a = sel.iter().map(|l| l.in_point).min().unwrap_or(Tick(0)).max(Tick(0));
-        let b = sel.iter().map(|l| l.out_point).max().unwrap_or(comp.duration).min(comp.duration);
-        (a, b)
-    };
-    let (offset, dur) = if adjust && span.1 > span.0 { (span.0, span.1 - span.0) } else { (Tick(0), comp.duration) };
-    let new = s.edit("Pre-compose", None, |proj, st| {
-        let mut inner = comp.nested_like(comp.width, comp.height, dur);
-        inner.layers = comp.layers.iter().filter(|l| ids.contains(&l.id)).cloned().collect();
-        for l in &mut inner.layers {
-            if l.parent.is_some_and(|p| !ids.contains(&p)) {
-                l.parent = None;
-            }
-            if l.track_matte.is_some_and(|m| !ids.contains(&m.layer)) {
-                l.track_matte = None;
-            }
-            l.start_time -= offset;
-            l.in_point -= offset;
-            l.out_point -= offset;
-        }
-        let iid = proj.add_item(&name, Label::Sandstone, None, ItemKind::Comp(inner.into()));
-        let mut l = build::layer(proj, &comp, &name, LayerSource::Comp { item: iid }, (comp.width, comp.height), Some(dur));
-        l.name = name.clone();
-        l.start_time = offset;
-        l.in_point = offset;
-        l.out_point = offset + dur;
-        let c = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        let at = c.layers.iter().position(|l| ids.contains(&l.id)).unwrap_or(0);
-        c.layers.retain(|l| !ids.contains(&l.id));
-        let lid = l.id;
-        c.layers.insert(at.min(c.layers.len()), l);
-        st.selected_layers = vec![lid];
-        Ok((iid, lid))
-    })?;
-    if b_p(p, "open").unwrap_or(false) {
-        s.open_comp(new.0);
-    }
-    Ok(json!({"comp": new.0.0, "layer": new.1.0}))
-}
-
-fn add_mask(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, lid) = layer_p(s, p, "layer.addMask")?;
-    let layer = s.project.comp(cid).and_then(|c| c.layer(lid)).ok_or(EngineError::NoComp)?.clone();
-    let (w, h) = effectcraft_render::source_size(&s.project, &layer);
-    let (w, h) = if w == 0 { (400.0, 300.0) } else { (w as f64, h as f64) };
-    let shape = str_p(p, "shape").unwrap_or("rect");
-    let r = p.get("rect").and_then(Value::as_array).map(|a| [0, 1, 2, 3].map(|i| a.get(i).and_then(Value::as_f64).unwrap_or(0.0)));
-    let (cx, cy, rw, rh) = match r {
-        Some([x, y, rw, rh]) => (x + rw / 2.0, y + rh / 2.0, rw, rh),
-        None => (if w > 0.0 { w / 2.0 } else { 0.0 }, h / 2.0, w * 0.6, h * 0.6),
-    };
-    // The shape tools' masks: rectangle, ellipse, rounded rectangle, polygon or star.
-    let path = super::shape_tool::mask_path(shape, [cx, cy], [rw, rh])
-        .ok_or_else(|| bad("layer.addMask", format!("unknown shape `{shape}`; one of rect, ellipse, rounded, polygon, star")))?;
-    let mode = str_p(p, "mode").and_then(MaskMode::from_name).unwrap_or(MaskMode::Add);
-    let cycle = s.prefs.appearance.cycle_mask_colors;
-    let uid = s.edit("New Mask", None, |proj, _| {
-        let mut next = proj.next_id;
-        let l = layer_mut(proj, cid, lid)?;
-        let masks = l.props.sub_mut("masks").ok_or_else(|| bad("layer.addMask", "this layer can't have masks"))?;
-        let n = masks.children.len();
-        let g = build::mask(&mut Ids(&mut next), &format!("Mask {}", n + 1), path, mode, crate::prefs::mask_color(cycle, n));
-        let uid = g.uid;
-        masks.children.push(g.into());
-        proj.next_id = next;
-        Ok(uid)
-    })?;
-    Ok(json!({"mask": uid}))
-}
-
-fn mask_props(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, lid) = layer_p(s, p, "layer.setMask")?;
-    let target = p.get("mask").cloned().unwrap_or(json!(1));
-    let mode = str_p(p, "mode").and_then(MaskMode::from_name);
-    let inverted = b_p(p, "inverted");
-    s.edit("Mask Settings", None, |proj, _| {
-        let l = layer_mut(proj, cid, lid)?;
-        let masks = l.props.sub_mut("masks").ok_or_else(|| bad("layer.setMask", "the layer has no masks (add one with layer.addMask)"))?;
-        let g = match &target {
-            Value::Number(n) => {
-                let n = n.as_u64().unwrap_or(1);
-                if let Some(i) = masks.children.iter().position(|c| c.uid() == n) {
-                    masks.children[i].as_group_mut()
-                } else {
-                    masks.children.get_mut(n.saturating_sub(1) as usize).and_then(|c| c.as_group_mut())
-                }
-            }
-            Value::String(name) => masks.children.iter_mut().find(|c| c.name() == name).and_then(|c| c.as_group_mut()),
-            _ => None,
-        }
-        .ok_or_else(|| bad("layer.setMask", "no such mask"))?;
-        if let GroupKind::Mask { mode: m, inverted: inv, .. } = &mut g.kind {
-            if let Some(mm) = mode {
-                *m = mm;
-            }
-            if let Some(i) = inverted {
-                *inv = i;
-            }
-        }
-        Ok(())
-    })?;
-    Ok(Value::Null)
-}
-
-fn add_shape_item(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, lid) = layer_p(s, p, "layer.addShapeItem")?;
-    let kind = str_p(p, "kind").ok_or_else(|| bad("layer.addShapeItem", "missing `kind`"))?.to_string();
-    // `group`: a uid or a property path (`contents/group`).
-    let group_uid = match p.get("group") {
-        Some(Value::String(path)) => Some(
-            s.project
-                .comp(cid)
-                .and_then(|c| c.layer(lid))
-                .and_then(|l| l.props.group(path))
-                .map(|g| g.uid)
-                .ok_or_else(|| bad("layer.addShapeItem", format!("no group `{path}`")))?,
-        ),
-        v => v.and_then(Value::as_u64),
-    };
-    let uid = s.edit("Add Shape Item", None, |proj, _| {
-        let mut next = proj.next_id;
-        let mut ids = Ids(&mut next);
-        // Front / Bevel / Side / Back ▸ property: into the group's surface item (one per group).
-        if let Some((surface, prop)) = build::shape_surface_kind(&kind) {
-            let target = shape_item_target(proj, cid, lid, group_uid)?;
-            let item = match target.children.iter().position(|c| matches!(c, Node::Group(g) if g.match_id == surface)) {
-                Some(i) => i,
-                None => {
-                    let g = build::shape_surface(&mut ids, surface).ok_or_else(|| bad("layer.addShapeItem", format!("unknown kind `{kind}`")))?;
-                    target.children.push(g.into());
-                    target.children.len() - 1
-                }
-            };
-            let Some(Node::Group(g)) = target.children.get_mut(item) else { return Err(bad("layer.addShapeItem", "no such group")) };
-            if g.get(prop).is_none() {
-                let p = build::shape_surface_prop(&mut ids, prop).ok_or_else(|| bad("layer.addShapeItem", format!("unknown kind `{kind}`")))?;
-                g.children.push(p.into());
-            }
-            let uid = g.uid;
-            proj.next_id = next;
-            return Ok(uid);
-        }
-        let g = match kind.as_str() {
-            "group" => build::shape_group(&mut ids, "Group 1", vec![]),
-            "rect" | "rectangle" => build::shape_rect(&mut ids, [200.0, 200.0], [0.0, 0.0], 0.0),
-            "ellipse" => build::shape_ellipse(&mut ids, [200.0, 200.0], [0.0, 0.0]),
-            "star" => build::shape_star(&mut ids, true, 5.0, [0.0, 0.0], 100.0, 50.0),
-            "polygon" => build::shape_star(&mut ids, false, 5.0, [0.0, 0.0], 100.0, 0.0),
-            "fill" => build::shape_fill(&mut ids, [1.0, 0.0, 0.0, 1.0]),
-            "stroke" => build::shape_stroke(&mut ids, [1.0, 1.0, 1.0, 1.0], 2.0),
-            "path" => build::shape_path(&mut ids, Default::default()),
-            "gfill" | "gradientFill" => build::shape_gradient_fill(&mut ids, false, [-100.0, 0.0], [100.0, 0.0], Default::default()),
-            "gstroke" | "gradientStroke" => build::shape_gradient_stroke(&mut ids, false, [-100.0, 0.0], [100.0, 0.0], Default::default(), 2.0),
-            "trim" | "trimPaths" => build::shape_trim(&mut ids, 0.0, 100.0, 0.0),
-            "repeater" => build::shape_repeater(&mut ids, 3.0, [100.0, 0.0]),
-            k => build::shape_simple_op(&mut ids, k).ok_or_else(|| bad("layer.addShapeItem", format!("unknown kind `{k}`")))?,
-        };
-        let uid = g.uid;
-        proj.next_id = next;
-        shape_item_target(proj, cid, lid, group_uid)?.children.push(g.into());
-        Ok(uid)
-    })?;
-    // The new item's property path, ready for prop.set / add_keyframe (`contents/trim#2/end`).
-    let path = s.project.comp(cid).and_then(|c| c.layer(lid)).and_then(|l| l.props.match_path_of(uid));
-    Ok(json!({"uid": uid, "path": path}))
-}
-
-/// The contents a new shape item goes into: the shape group `group_uid` (its Contents), else the
-/// layer's Contents.
-fn shape_item_target(proj: &mut Project, cid: ItemId, lid: LayerId, group_uid: Option<u64>) -> Result<&mut PropGroup> {
-    let l = layer_mut(proj, cid, lid)?;
-    let contents = l.props.sub_mut("contents").ok_or_else(|| bad("layer.addShapeItem", "not a shape layer"))?;
-    Ok(match group_uid {
-        Some(u) => contents
-            .find_group_mut(u)
-            .and_then(|g| if g.match_id == "contents" { Some(g) } else { g.sub_mut("contents") })
-            .ok_or_else(|| bad("layer.addShapeItem", "no such group"))?,
-        None => contents,
-    })
-}
-
-/// `layer.setText`: sets a text layer's Source Text and/or character attributes at the CTI.
-///
-/// A `font` name is also added to the recent fonts and the preferences saved. With an empty
-/// `range` and no `text`, while that layer is being edited and its document is non-empty,
-/// recognised character attributes are also staged in the pending insertion style without
-/// changing existing characters. Paragraph/document attributes still apply through the edit;
-/// the session is bumped whenever this branch runs. Document changes use [`Session::edit`],
-/// merged by `merge_p`. With `text` given, a layer whose name is empty or starts with `Text`
-/// takes the new first line (up to 40 characters) when that line is non-empty. Replies `null`.
-fn set_text(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, lid) = layer_p(s, p, "layer.setText")?;
-    // The Character panel's recent fonts (Settings ▸ Type ▸ Number of Recent Fonts to Display).
-    if let Some(f) = str_p(p, "font") {
-        s.prefs.push_recent_font(f);
-        s.save_prefs();
-    }
-    let t = s.time();
-    let range = text_range_p(p);
-    // Character attributes with only a caret (no selected text) set the insertion style.
-    if let Some(r) = range.clone().filter(|r| r.is_empty() && str_p(p, "text").is_none())
-        && s.state.text_edit.as_ref().is_some_and(|e| e.layer == lid)
-        && let Some(doc) = super::text_edit::layer_doc(s, lid)
-        && doc.char_len() > 0
-        && let Some(obj) = p.as_object()
-        && let Some(e) = s.state.text_edit.as_mut()
-    {
-        let mut st = e.pending.clone().unwrap_or_else(|| doc.insertion_style(r.start));
-        let mut any = false;
-        for (k, v) in obj {
-            any |= effectcraft_keyframe::text_doc::apply_char_attr(&mut st, k, v).map_err(|m| bad("layer.setText", m))?;
-        }
-        if any {
-            e.pending = Some(st);
-        }
-        s.bump();
-    }
-    // A changed Source Text is handled by `Session::edit`: its boundary clamps the selection and
-    // starts a new IME epoch only when the CTI document actually changed, so an identical text
-    // write stays a no-op and keeps the editor's owner.
-    s.edit("Edit Text", merge_p(p), |proj, _| {
-        let l = layer_mut(proj, cid, lid)?;
-        let lt = l.layer_time(t);
-        let pr = l.props.prop_mut("text/sourceText").ok_or_else(|| bad("layer.setText", "not a text layer"))?;
-        let mut doc = match pr.value_at(lt) {
-            KV::Text(d) => *d,
-            KV::Str(t) => TextDoc::plain(&t),
-            _ => TextDoc::default(),
-        };
-        apply_text_params("layer.setText", p, &mut doc, range.clone())?;
-        pr.set_value_at(lt, KV::Text(Box::new(doc.clone())));
-        if let Some(first) = doc.text.lines().next()
-            && str_p(p, "text").is_some()
-            && !first.is_empty()
-            && (l.name.starts_with("Text") || l.name.is_empty())
-        {
-            l.name = first.chars().take(40).collect();
-        }
-        Ok(())
-    })?;
-    Ok(Value::Null)
-}
-
-/// Move Position by `(dx, dy)`, including every key. Separated dimensions move X and Y as well
-/// as the combined property the channels were split from.
-pub(crate) fn offset_position(tr: &mut PropGroup, dx: f64, dy: f64) {
-    if dx == 0.0 && dy == 0.0 {
-        return;
-    }
-    if tr.get("positionX").is_some() {
-        for (name, d) in [("positionX", dx), ("positionY", dy)] {
-            if let Some(pr) = tr.get_mut(name) {
-                pr.value = KV::Scalar(pr.value.as_f64() + d);
-                for k in &mut pr.keys {
-                    k.value = KV::Scalar(k.value.as_f64() + d);
-                }
-            }
-        }
-    }
-    if let Some(pr) = tr.get_mut("position") {
-        let shift = |v: &KV| match v {
-            KV::Vec2(a) => KV::Vec2([a[0] + dx, a[1] + dy]),
-            other => {
-                let a = other.as_vec3();
-                KV::Vec3([a[0] + dx, a[1] + dy, a[2]])
-            }
-        };
-        pr.value = shift(&pr.value);
-        for k in &mut pr.keys {
-            k.value = shift(&k.value);
-        }
-    }
-}
-
-/// Set a layer's Position at layer time `lt` to `f(current)`: X/Y/Z Position when its dimensions
-/// are separated.
-pub(crate) fn update_position(tr: &mut PropGroup, lt: Tick, f: impl Fn([f64; 3]) -> [f64; 3]) {
-    const SEPARATE: [&str; 3] = ["positionX", "positionY", "positionZ"];
-    if tr.get("positionX").is_some() {
-        let v = f(SEPARATE.map(|m| tr.get(m).map(|p| p.value_at(lt).as_f64()).unwrap_or(0.0)));
-        for (m, x) in SEPARATE.iter().zip(v) {
-            if let Some(pr) = tr.get_mut(m) {
-                pr.set_value_at(lt, KV::Scalar(x));
-            }
-        }
-    } else if let Some(pr) = tr.get_mut("position") {
-        let v = f(pr.value_at(lt).as_vec3());
-        pr.set_value_at(lt, KV::Vec3(v));
-    }
-}
-
-/// A Transform property's default (Reset) by match id: the anchor at the centre of the source
-/// (`w`×`h`), the position at the comp's (`cw`×`ch`), 100% scale and opacity, no rotation.
-pub(crate) fn transform_default(m: &str, (w, h): (f64, f64), (cw, ch): (f64, f64)) -> Option<KV> {
-    Some(match m {
-        "anchor" => KV::Vec3([w / 2.0, h / 2.0, 0.0]),
-        "position" => KV::Vec3([cw / 2.0, ch / 2.0, 0.0]),
-        "positionX" => KV::Scalar(cw / 2.0),
-        "positionY" => KV::Scalar(ch / 2.0),
-        "positionZ" | "rotation" | "rotationX" | "rotationY" => KV::Scalar(0.0),
-        "scale" => KV::Vec3([100.0; 3]),
-        "orientation" => KV::Vec3([0.0; 3]),
-        "opacity" => KV::Scalar(100.0),
-        _ => return None,
-    })
-}
-
-fn transform_op(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, ids) = layers_p(s, p)?;
-    let ids = unlocked(s, cid, ids, "layer.transform")?;
-    let op = str_p(p, "op").unwrap_or("reset").to_string();
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
-    let t = s.time();
-    let sizes: Vec<(LayerId, (u32, u32))> =
-        comp.layers.iter().filter(|l| ids.contains(&l.id)).map(|l| (l.id, effectcraft_render::source_size(&s.project, l))).collect();
-    s.edit("Transform", None, |proj, _| {
-        for (lid, (w, h)) in &sizes {
-            let l = layer_mut(proj, cid, *lid)?;
-            let lt = l.layer_time(t);
-            let (cw, ch) = (comp.width as f64, comp.height as f64);
-            let (w, h) = (*w as f64, *h as f64);
-            let Some(tr) = l.transform_mut() else { continue };
-            let set = |tr: &mut PropGroup, m: &str, v: KV| {
-                if let Some(pr) = tr.get_mut(m) {
-                    pr.set_value_at(lt, v);
-                }
-            };
-            match op.as_str() {
-                "reset" => {
-                    for m in ["anchor", "scale", "rotation", "rotationX", "rotationY", "orientation", "opacity"] {
-                        if let Some(v) = transform_default(m, (w, h), (cw, ch)) {
-                            set(tr, m, v);
-                        }
-                    }
-                    update_position(tr, lt, |_| [cw / 2.0, ch / 2.0, 0.0]);
-                }
-                // Centred in the frame; a 3D layer keeps its depth.
-                "center" => update_position(tr, lt, |p| [cw / 2.0, ch / 2.0, p[2]]),
-                "fit" | "fitWidth" | "fitHeight" if w > 0.0 && h > 0.0 => {
-                    let (sx, sy) = match op.as_str() {
-                        "fitWidth" => (cw / w, cw / w),
-                        "fitHeight" => (ch / h, ch / h),
-                        _ => (cw / w, ch / h),
-                    };
-                    let z = |m: &str, d: f64| tr.get(m).map(|p| p.value_at(lt).as_vec3()[2]).unwrap_or(d);
-                    let (sz, az) = (z("scale", 100.0), z("anchor", 0.0));
-                    set(tr, "scale", KV::Vec3([sx * 100.0, sy * 100.0, sz]));
-                    update_position(tr, lt, |p| [cw / 2.0, ch / 2.0, p[2]]);
-                    set(tr, "anchor", KV::Vec3([w / 2.0, h / 2.0, az]));
-                }
-                "flipH" | "flipV" => {
-                    let cur = tr.get("scale").map(|p| p.value_at(lt).as_vec3()).unwrap_or([100.0; 3]);
-                    let v = if op == "flipH" { [-cur[0], cur[1], cur[2]] } else { [cur[0], -cur[1], cur[2]] };
-                    set(tr, "scale", KV::Vec3(v));
-                }
-                _ => {}
-            }
-        }
-        Ok(())
-    })?;
-    Ok(Value::Null)
-}
-
-/// Layer ▸ Layer Settings: cameras and lights open their own settings; solids (and adjustment
-/// layers, which are solids) edit their Solid Settings. With `affectAll: false`, a solid other
-/// layers also use is copied into a new solid for this layer instead of being changed for all of
-/// them (After Effects' "Affect all layers that use this solid"). `name` renames the layer and
-/// its solid.
-fn layer_settings(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, lid) = layer_p(s, p, "layer.settings")?;
-    // Cameras and lights open their own settings (Camera Settings / Light Settings).
-    match s.project.comp(cid).and_then(|c| c.layer(lid)).map(|l| l.source.clone()) {
-        Some(LayerSource::Camera) => return s.execute("layer.cameraSettings", with_layer(p, lid)),
-        Some(LayerSource::Light { .. }) => return s.execute("layer.lightSettings", with_layer(p, lid)),
-        _ => {}
-    }
-    let color = color_p(p, "color");
-    let w = p.get("width").and_then(Value::as_u64).map(limits::size);
-    let h = p.get("height").and_then(Value::as_u64).map(limits::size);
-    let pixel_aspect = pixel_aspect_p(p)?;
-    let name = str_p(p, "name").map(str::trim).filter(|n| !n.is_empty()).map(str::to_string);
-    let affect_all = p.get("affectAll").and_then(Value::as_bool).unwrap_or(true);
-    let solid = s.edit("Layer Settings", None, |proj, _| {
-        let src = layer_mut(proj, cid, lid)?.source.clone();
-        if let Some(n) = &name {
-            layer_mut(proj, cid, lid)?.name = n.clone();
-        }
-        let LayerSource::Solid { item } = src else { return Ok(None) };
-        let shared = proj.comps().flat_map(|(_, c)| &c.layers).filter(|l| l.source == src).count() > 1;
-        let target = if shared && !affect_all {
-            // This layer gets its own copy of the solid.
-            let it = proj.item(item).ok_or_else(|| bad("layer.settings", "the layer's solid is missing"))?.clone();
-            let copy = proj.add_item(name.as_deref().unwrap_or(&it.name), it.label, it.parent, it.kind);
-            layer_mut(proj, cid, lid)?.source = LayerSource::Solid { item: copy };
-            copy
-        } else {
-            item
-        };
-        let it = proj.item_mut(target).ok_or_else(|| bad("layer.settings", "the layer's solid is missing"))?;
-        if let Some(n) = &name {
-            it.name = n.clone();
-        }
-        if let ItemKind::Solid(so) = &mut it.kind {
-            so.color = color.unwrap_or(so.color);
-            so.width = w.unwrap_or(so.width);
-            so.height = h.unwrap_or(so.height);
-            so.pixel_aspect = pixel_aspect.unwrap_or(so.pixel_aspect);
-        }
-        Ok(Some(target))
-    })?;
-    Ok(match solid {
-        Some(item) => json!({"layer": lid.0, "solid": item.0}),
-        None => json!({"layer": lid.0}),
-    })
-}
-
-/// Layer Settings applies to solids (and adjustment layers), nulls, cameras and lights.
-fn has_layer_settings(s: &Session) -> std::result::Result<(), String> {
-    has_layers(s)?;
-    let l = s.active_comp().zip(s.state.selected_layers.first()).and_then(|(c, l)| c.layer(*l)).ok_or("select a layer first")?;
-    match l.source {
-        LayerSource::Solid { .. } | LayerSource::Null | LayerSource::Camera | LayerSource::Light { .. } => Ok(()),
-        _ => Err("this kind of layer has no settings".into()),
-    }
-}
-
-fn with_layer(p: &Value, lid: LayerId) -> Value {
-    let mut p = if p.is_object() { p.clone() } else { json!({}) };
-    p["layer"] = json!(lid.0);
-    p
-}
-
-pub fn specs() -> Vec<CommandSpec> {
-    vec![
-        cmd!(
-            "layer.newText",
-            "Text",
-            ["Layer", "New"],
-            Some("Cmd+Alt+Shift+T"),
-            "{text?, name? (layer name; default the text), position? [x,y], box? [x,y,w,h] (paragraph text, comp space), vertical?, edit? (start editing), font?, style?, size?, fill?, stroke?, applyFill?, applyStroke?, strokeWidth?, tracking?, leading?, baselineShift?, hScale?, vScale?, tsume?, fauxBold?, fauxItalic?, allCaps?, smallCaps?, baseline?, superscript?, subscript?, kerning?, ligatures?, justify?, indentLeft?, indentRight?, indentFirst?, spaceBefore?, spaceAfter?, direction?, composer?, hangingPunctuation?, strokeOverFill?} (attributes as layer.setText)",
-            has_comp,
-            new_text
-        ),
-        cmd!("layer.newSolid", "Solid...", ["Layer", "New"], Some("Cmd+Y"), "{name?, color? #hex|[r,g,b], width?, height?, pixelAspect?}", has_comp, new_solid),
-        cmd!("layer.newNull", "Null Object", ["Layer", "New"], Some("Cmd+Alt+Shift+Y"), "{name?}", has_comp, new_null),
-        cmd!(
-            "layer.newShape",
-            "Shape Layer",
-            ["Layer", "New"],
-            None,
-            "{kind?: rect|rounded|ellipse|star|polygon|none, name?, size?, fill?, fillType?, fillBlend?, fillOpacity?, stroke?, strokeType?, strokeBlend?, strokeOpacity?, strokeWidth?, position?}",
-            has_comp,
-            new_shape
-        ),
-        cmd!("layer.newAdjustment", "Adjustment Layer", ["Layer", "New"], Some("Cmd+Alt+Y"), "{name?}", has_comp, new_adjustment),
-        cmd!(
-            "layer.settings",
-            "Layer Settings...",
-            ["Layer"],
-            Some("Cmd+Shift+Y"),
-            "{layer?, name?, color?, width?, height?, pixelAspect?, affectAll?: bool (default true; false gives this layer its own copy of a solid other layers use)} → {layer, solid?}",
-            has_layer_settings,
-            layer_settings
-        ),
-        cmd!(
-            "layer.addItem",
-            "Add Footage to Comp",
-            ["File"],
-            Some("Cmd+/"),
-            "{item: id|name, time? (s, the In point), index? (1-based stack position; default above the selected layer), position? ([x, y] comp px; default the centre), duration? (s, for a still)}",
-            has_comp,
-            add_item
-        ),
-        cmd!(
-            "layer.replaceSource",
-            "Replace Layer Source",
-            [],
-            Some("Cmd+Alt+/"),
-            "{comp?, layers?, layer?, item?: id|name (default the Project panel selection), fixExpressions?: bool (accepted for After Effects compatibility)} → {layers, item}",
-            has_replace_source,
-            replace_source
-        ),
-        cmd!("layer.select", "Select Layers", [], None, "{layers: [id|name|#n], add?, toggle?}", has_comp, select),
-        cmd!("layer.selectNext", "Select Next Layer", [], Some("Cmd+ArrowDown"), "{add?}", has_comp, select_next),
-        cmd!("layer.selectPrevious", "Select Previous Layer", [], Some("Cmd+ArrowUp"), "{add?}", has_comp, select_prev),
-        cmd!("layer.extendSelectionNext", "Extend Selection to Next Layer", [], Some("Cmd+Shift+ArrowDown"), "{}", has_comp, |s, _| select_step(
-            s,
-            &json!({"add": true}),
-            1
-        )),
-        cmd!("layer.extendSelectionPrevious", "Extend Selection to Previous Layer", [], Some("Cmd+Shift+ArrowUp"), "{}", has_comp, |s, _| select_step(
-            s,
-            &json!({"add": true}),
-            -1
-        )),
-        cmd!(
-            "layer.setSwitch",
-            "Layer Switch",
-            [],
-            None,
-            "{layers?, switch: video|audio|solo|lock|shy|collapse|quality|fx|frameBlend|motionBlur|adjustment|threeD|guide|preserveTransparency, value?, merge?, others? (the named layers alone: the other layers get the opposite state, or come back)}",
-            has_layers,
-            set_switch
-        ),
-        cmd!("layer.rename", "Rename", [], Some("Enter"), "{layer?, name}", has_layers, rename),
-        cmd!("layer.setComment", "Layer Comment", [], None, "{layers?, comment}", has_layers, set_comment),
-        cmd!("layer.setBlendMode", "Blending Mode", [], None, "{layers?, mode?: Normal|Multiply|Screen|…, step?: ±1}", has_layers, blend),
-        cmd!(
-            "layer.setTrackMatte",
-            "Track Matte",
-            [],
-            None,
-            "{layer?, matte: layer|null, kind?: alpha|alphaInverted|luma|lumaInverted}",
-            has_layers,
-            track_matte
-        ),
-        cmd!("layer.setParent", "Parent", [], None, "{layers?, parent: layer|null, compensate?: bool}", has_layers, set_parent),
-        cmd!(
-            "layer.timing",
-            "Layer Timing",
-            [],
-            None,
-            "{layers?, op?: moveInToTime|moveOutToTime|moveInToStart|moveOutToEnd|trimInToTime|trimOutToTime, delta?, start?, in?, out?, inDelta?, outDelta? (seconds, per layer), merge?}",
-            has_layers,
-            timing
-        ),
-        cmd!("layer.moveInToStart", "Move Layer In Point to Beginning of Comp", [], Some("Alt+Home"), "{layers?}", has_layers, |s, p| timing(
-            s,
-            &with(p, "op", json!("moveInToStart"))
-        )),
-        cmd!("layer.moveOutToEnd", "Move Layer Out Point to End of Comp", [], Some("Alt+End"), "{layers?}", has_layers, |s, p| timing(
-            s,
-            &with(p, "op", json!("moveOutToEnd"))
-        )),
-        cmd!("layer.moveEarlier", "Move Layers 1 Frame Earlier", [], Some("Alt+PageUp"), "{layers?}", has_layers, |s, p| move_frames(s, p, -1)),
-        cmd!("layer.moveLater", "Move Layers 1 Frame Later", [], Some("Alt+PageDown"), "{layers?}", has_layers, |s, p| move_frames(s, p, 1)),
-        cmd!("layer.moveEarlier10", "Move Layers 10 Frames Earlier", [], Some("Alt+Shift+PageUp"), "{layers?}", has_layers, |s, p| move_frames(s, p, -10)),
-        cmd!("layer.moveLater10", "Move Layers 10 Frames Later", [], Some("Alt+Shift+PageDown"), "{layers?}", has_layers, |s, p| move_frames(s, p, 10)),
-        cmd!("layer.slip", "Slip Edit", [], None, "{layers?, delta? (seconds) | frames?, merge?}", has_layers, slip),
-        cmd!("layer.slipBack", "Slip Edit 1 Frame Earlier", [], None, "{layers?}", has_layers, |s, p| {
-            let mut p = p.clone();
-            p["frames"] = json!(-1);
-            slip(s, &p)
-        }),
-        cmd!("layer.slipForward", "Slip Edit 1 Frame Later", [], None, "{layers?}", has_layers, |s, p| {
-            let mut p = p.clone();
-            p["frames"] = json!(1);
-            slip(s, &p)
-        }),
-        cmd!("layer.arrange", "Arrange", ["Layer", "Arrange"], None, "{layers?, to: front|forward|backward|back, index?, above?: layer}", has_layers, arrange),
-        cmd!(
-            "layer.precompose",
-            "Pre-compose...",
-            ["Layer"],
-            Some("Cmd+Shift+C"),
-            "{layers?, name?, mode?: move|leave, adjustDuration?, open?}",
-            has_layers,
-            precompose
-        ),
-        cmd!(
-            "layer.addMask",
-            "New Mask",
-            ["Layer", "Mask"],
-            Some("Cmd+Shift+N"),
-            "{layer?, shape?: rect|ellipse|rounded|polygon|star, rect? [x,y,w,h] (layer space; a polygon or star fits its width), mode?}",
-            has_layers,
-            add_mask
-        ),
-        cmd!("layer.setMask", "Mask Mode", [], None, "{layer?, mask: index|uid|name, mode?, inverted?}", has_layers, mask_props),
-        cmd!(
-            "layer.addShapeItem",
-            "Add (Shape)",
-            [],
-            None,
-            "{layer?, kind: group|rect|ellipse|star|polygon|path|fill|stroke|gfill|gstroke|trim|repeater|round|offset|pucker|twist|zigzag|wiggle|merge|frontColor|bevelColor|sideColor|backColor, group?: uid|path} → {uid, path} (frontColor…backColor: the group's Front / Bevel / Side / Back item, which colours that surface of every extruded paint in the group in Advanced 3D)",
-            has_layers,
-            add_shape_item
-        ),
-        cmd!(
-            "layer.setText",
-            "Edit Text",
-            [],
-            None,
-            "{layer?, range?: [start, end] (characters; default all), text?, font?, style?, size?, fill?, stroke?, applyFill?, applyStroke?, strokeWidth?, tracking?, leading?: px|\"auto\", baselineShift? px, hScale? %, vScale? %, tsume? %, fauxBold?, fauxItalic?, allCaps?, smallCaps?, baseline?: normal|superscript|subscript, superscript?, subscript?, kerning?: metrics|optical|number, ligatures?, discretionaryLigatures? (OpenType), contextualAlternates?, stylisticAlternates?, stylisticSets?: [1–20], ss01?, ss02?, ss03?, ss04?, ss05?, ss06?, ss07?, ss08?, ss09?, ss10?, ss11?, ss12?, ss13?, ss14?, ss15?, ss16?, ss17?, ss18?, ss19?, ss20?, swash?, titling?, ordinals?, fractions?, allSmallCaps?, figureStyle?: default|lining|oldStyle, figureWidth?: default|proportional|tabular, figures?, variations?: {tag: value} (variable font axes; null resets), justify?: left|center|right|justifyLeft|justifyCenter|justifyRight|justifyAll, indentLeft?, indentRight?, indentFirst?, spaceBefore?, spaceAfter?, direction?: ltr|rtl, composer?: everyLine|singleLine, hangingPunctuation?, strokeOverFill?, box?: [x,y,w,h]|null (layer space), vertical?}",
-            has_layers,
-            set_text
-        ),
-        cmd!(
-            "layer.transform",
-            "Transform",
-            ["Layer", "Transform"],
-            None,
-            "{layers?, op: reset|center|fit|fitWidth|fitHeight|flipH|flipV}",
-            has_layers,
-            transform_op
-        ),
-    ]
-}
-
-#[allow(dead_code)]
-fn unused(_: &Comp) {}
-
-#[cfg(test)]
-mod parent_chain_tests {
-    use super::*;
-    use std::sync::Arc;
-
-    fn fixture() -> (Session, u64, u64, u64) {
-        let mut s = Session::default();
-        s.execute("comp.new", json!({"name":"Parent safety","width":16,"height":16,"duration":1})).unwrap();
-        let a = s.execute("layer.newSolid", json!({"name":"A"})).unwrap()["layer"].as_u64().unwrap();
-        let b = s.execute("layer.newSolid", json!({"name":"B"})).unwrap()["layer"].as_u64().unwrap();
-        let c = s.execute("layer.newSolid", json!({"name":"C"})).unwrap()["layer"].as_u64().unwrap();
-        for id in [a, b, c] {
-            s.execute("prop.set", json!({"layer":id,"path":"transform/anchor","value":[0,0,0]})).unwrap();
-        }
-        s.execute("prop.set", json!({"layer":a,"path":"transform/position","value":[100,200,0]})).unwrap();
-        s.execute("prop.set", json!({"layer":c,"path":"transform/position","value":[10,20,0]})).unwrap();
-        s.history.undo.clear();
-        (s, a, b, c)
-    }
-    fn malformed_parent(s: &mut Session, child: u64, parent: u64) {
-        let cid = s.active_comp_id().unwrap();
-        Arc::make_mut(&mut s.project).comp_mut(cid).unwrap().layer_mut(LayerId(child)).unwrap().parent = Some(LayerId(parent));
-    }
-    fn assert_atomic_error(s: &mut Session, child: u64, parent: u64, compensate: bool, message: &str) {
-        let before = s.project.clone();
-        let revision = s.revision;
-        let undo = s.history.undo.len();
-        let err = s.execute("layer.setParent", json!({"layers":[child],"parent":parent,"compensate":compensate})).unwrap_err();
-        assert!(err.to_string().contains(message), "{err}");
-        assert!(Arc::ptr_eq(&before, &s.project));
-        assert_eq!(s.revision, revision);
-        assert_eq!(s.history.undo.len(), undo);
-    }
-    #[test]
-    fn loaded_cycle_excluding_selected_child_is_rejected_atomically() {
-        for compensate in [true, false] {
-            let (mut s, a, b, c) = fixture();
-            // Simulate a malformed loaded project. Never execute this on the unguarded baseline.
-            malformed_parent(&mut s, a, b);
-            malformed_parent(&mut s, b, a);
-            assert_atomic_error(&mut s, c, a, compensate, "existing cycle");
-        }
-    }
-    #[test]
-    fn dangling_loaded_parent_is_rejected_atomically() {
-        for compensate in [true, false] {
-            let (mut s, a, _, c) = fixture();
-            malformed_parent(&mut s, a, u64::MAX);
-            assert_atomic_error(&mut s, c, a, compensate, "missing layer");
-        }
-    }
-    #[test]
-    fn selected_descendant_and_direct_self_are_rejected() {
-        let (mut s, a, _, c) = fixture();
-        assert_atomic_error(&mut s, c, c, false, "create a cycle");
-        s.execute("layer.setParent", json!({"layers":[a],"parent":c,"compensate":false})).unwrap();
-        assert_atomic_error(&mut s, c, a, true, "create a cycle");
-    }
-    #[test]
-    fn ordinary_parent_and_unparent_keep_explicit_false_and_undo_semantics() {
-        for compensate in [true, false] {
-            let (mut s, a, _, c) = fixture();
-            let old = s.project.clone();
-            let world = |s: &Session| {
-                let cid = s.active_comp_id().unwrap();
-                let comp = s.active_comp().unwrap();
-                let ctx = effectcraft_render::EvalCtx::new(&s.project, cid, comp, s.time());
-                ctx.world_matrix(comp.layer(LayerId(c)).unwrap()).apply(effectcraft_geom::Vec3::ZERO)
-            };
-            let before = world(&s);
-            s.execute("layer.setParent", json!({"layers":[c],"parent":a,"compensate":compensate})).unwrap();
-            let expected = if compensate { before } else { before + effectcraft_geom::vec3(100.0, 200.0, 0.0) };
-            assert!((world(&s) - expected).length() < 1e-9);
-            assert_eq!(s.active_comp().unwrap().layer(LayerId(c)).unwrap().parent, Some(LayerId(a)));
-            assert_eq!(s.history.undo.len(), 1);
-            let parented = s.project.clone();
-            assert!(s.undo());
-            assert!(Arc::ptr_eq(&s.project, &old));
-            assert!(s.redo());
-            assert!(Arc::ptr_eq(&s.project, &parented));
-            s.execute("layer.setParent", json!({"layers":[c],"parent":null,"compensate":compensate})).unwrap();
-            assert_eq!(s.active_comp().unwrap().layer(LayerId(c)).unwrap().parent, None);
-            assert!(s.undo());
-            assert!(Arc::ptr_eq(&s.project, &parented));
-        }
-    }
-    #[test]
-    fn ancestor_and_lookup_work_budgets_fail_closed() {
-        let (mut s, a, b, c) = fixture();
-        malformed_parent(&mut s, a, b);
-        let comp = s.active_comp().unwrap();
-        // New solids are inserted above the selection: C,B,A. Walking A->B scans
-        // three then two layers, and compares the one selected child twice: seven work units.
-        assert_eq!(comp.layers.iter().map(|l| l.id).collect::<Vec<_>>(), vec![LayerId(c), LayerId(b), LayerId(a)]);
-        assert!(check_parent_chain(comp, &[LayerId(c)], Some(LayerId(a)), 2, 7).is_ok());
-        assert!(check_parent_chain(comp, &[LayerId(c)], Some(LayerId(a)), 2, 6).unwrap_err().to_string().contains("work limit"));
-        assert!(check_parent_chain(comp, &[LayerId(c)], Some(LayerId(a)), 2, 256).is_ok());
-        assert!(check_parent_chain(comp, &[LayerId(c)], Some(LayerId(a)), 1, 256).unwrap_err().to_string().contains("visit limit"));
-        assert!(check_parent_chain(comp, &[LayerId(c)], Some(LayerId(a)), 2, 1).unwrap_err().to_string().contains("work limit"));
-        assert!(check_parent_chain(comp, &[LayerId(c)], None, 0, 0).is_ok(), "unparenting does not traverse ancestors");
-    }
-
-    #[test]
-    fn well_formed_chain_beyond_renderer_depth_is_not_unnecessarily_rejected() {
-        let (s, _, _, c) = fixture();
-        let mut comp = s.active_comp().unwrap().clone();
-        let template = comp.layers.first().unwrap().clone();
-        for n in 0..80 {
-            let mut layer = template.clone();
-            layer.id = LayerId(10_000 + n);
-            layer.parent = (n < 79).then_some(LayerId(10_001 + n));
-            comp.layers.push(layer);
-        }
-        assert!(check_parent_chain(&comp, &[LayerId(c)], Some(LayerId(10_000)), 4096, 1_048_576).is_ok());
-    }
-}
diff --git a/crates/engine/src/commands/mod.rs b/crates/engine/src/commands/mod.rs
deleted file mode 100644
index 23388594b..000000000
--- a/crates/engine/src/commands/mod.rs
+++ /dev/null
@@ -1,613 +0,0 @@
-//! The command registry. Ids follow After Effects' menu structure; every menu item, panel button,
-//! shortcut and viewer/timeline gesture maps to one of these.
-
-mod align;
-mod align_data;
-mod anim;
-mod anim_presets;
-pub mod anim_tools;
-mod animation;
-pub(crate) mod app_more;
-mod autotrace;
-mod batch;
-mod camera_cmds;
-mod comp;
-pub(crate) mod comp_more;
-pub mod content_fill;
-mod create;
-mod edit;
-mod effect;
-pub mod essential;
-pub mod expr_tools;
-mod file;
-pub(crate) mod file_more;
-mod focus;
-pub mod footage_panel;
-pub(crate) mod frame_export;
-mod frontend;
-mod help;
-mod import_project;
-mod key_labels;
-mod key_transform;
-mod keys_more;
-mod layer;
-mod layer_menu;
-mod layer_time;
-pub(crate) mod link;
-mod liquify;
-mod lottie;
-pub mod markers;
-mod mask;
-pub mod mask_interp;
-pub(crate) mod model3d;
-mod nav_more;
-pub mod paint;
-pub mod panels_cmds;
-pub(crate) mod path_nulls;
-mod paths;
-mod project_items;
-pub(crate) mod prop;
-mod prop_groups;
-mod proxy;
-pub mod puppet;
-mod query;
-mod quick_offset;
-mod relink;
-pub(crate) mod relink_moved;
-mod render_queue;
-pub(crate) mod rig3d;
-pub mod roto_cmds;
-mod scene_detect;
-pub mod scripts;
-mod settings;
-pub mod shape_stroke;
-pub mod shape_tool;
-mod stubs;
-mod styles;
-mod text_anim;
-pub mod text_edit;
-mod three_d;
-pub mod time;
-mod timeline;
-mod track;
-mod view;
-pub mod viewer_cmds;
-pub(crate) mod vpe;
-pub(crate) mod vr_editor;
-mod warp_cmds;
-pub(crate) mod watch_folder;
-#[cfg(test)]
-pub(crate) use app_more::report_text as report_text_for_tests;
-pub(crate) use app_more::view_command;
-#[cfg(test)]
-pub(crate) use file::open as open_for_tests;
-#[cfg(test)]
-pub(crate) use keys_more::amplitudes as amplitudes_for_tests;
-#[cfg(test)]
-pub(crate) use mask::split_segment as split_segment_for_tests;
-
-use std::sync::OnceLock;
-
-use effectcraft_project::{Comp, ItemId, Layer, LayerId};
-use effectcraft_time::Tick;
-use serde_json::Value;
-
-use crate::{EngineError, Result, Session};
-
-pub type Run = fn(&mut Session, &Value) -> Result<Value>;
-pub type Enabled = fn(&Session) -> std::result::Result<(), String>;
-
-/// Metadata + implementation for one command.
-pub struct CommandSpec {
-    pub id: &'static str,
-    pub label: &'static str,
-    /// Menu placement, e.g. `["Layer", "New"]`. Empty = not in menus.
-    pub menu: &'static [&'static str],
-    /// Default shortcut (egui-style names, `Cmd` = ⌘ on macOS / Ctrl elsewhere).
-    pub shortcut: Option<&'static str>,
-    /// Further default shortcuts (the menus and tooltips show `shortcut`).
-    pub alt_shortcuts: &'static [&'static str],
-    /// Parameter description for agents and the MCP schema.
-    pub params: &'static str,
-    pub enabled: Enabled,
-    pub run: Run,
-    /// Record in the journal (false for pure queries).
-    pub journal: bool,
-}
-
-#[macro_export]
-macro_rules! cmd {
-    // Several default shortcuts: `["PageDown", "Cmd+ArrowRight"]`.
-    ($id:literal, $label:literal, [$($m:literal),*], [$sc:literal, $($alt:literal),+], $params:literal, $en:expr, $run:expr) => {
-        $crate::commands::CommandSpec { alt_shortcuts: &[$($alt),+], ..$crate::cmd!($id, $label, [$($m),*], Some($sc), $params, $en, $run) }
-    };
-    ($id:literal, $label:literal, [$($m:literal),*], $sc:expr, $params:literal, $en:expr, $run:expr) => {
-        $crate::commands::CommandSpec {
-            id: $id,
-            label: $label,
-            menu: &[$($m),*],
-            shortcut: $sc,
-            alt_shortcuts: &[],
-            params: $params,
-            enabled: $en,
-            run: $run,
-            journal: true,
-        }
-    };
-}
-#[macro_export]
-macro_rules! query {
-    ($id:literal, $label:literal, $params:literal, $run:expr) => {
-        $crate::commands::CommandSpec {
-            id: $id,
-            label: $label,
-            menu: &[],
-            shortcut: None,
-            alt_shortcuts: &[],
-            params: $params,
-            enabled: $crate::commands::always,
-            run: $run,
-            journal: false,
-        }
-    };
-}
-
-pub fn command_specs() -> &'static [CommandSpec] {
-    static SPECS: OnceLock<Vec<CommandSpec>> = OnceLock::new();
-    SPECS.get_or_init(|| {
-        let mut v = Vec::new();
-        v.extend(file::specs());
-        v.extend(crate::models::specs());
-        v.extend(edit::specs());
-        v.extend(comp::specs());
-        v.extend(layer::specs());
-        v.extend(styles::specs());
-        v.extend(three_d::specs());
-        v.extend(model3d::specs());
-        v.extend(rig3d::specs());
-        v.extend(text_anim::specs());
-        v.extend(text_edit::specs());
-        v.extend(layer_time::specs());
-        v.extend(prop::specs());
-        v.extend(prop_groups::specs());
-        v.extend(project_items::specs());
-        v.extend(anim::specs());
-        v.extend(anim_tools::specs());
-        v.extend(link::specs());
-        v.extend(markers::specs());
-        v.extend(mask::specs());
-        v.extend(paths::specs());
-        v.extend(effect::specs());
-        v.extend(time::specs());
-        v.extend(nav_more::specs());
-        v.extend(render_queue::specs());
-        v.extend(help::specs());
-        v.extend(query::specs());
-        v.extend(batch::specs());
-        v.extend(layer_menu::specs());
-        v.extend(create::specs());
-        v.extend(animation::specs());
-        v.extend(anim_presets::specs());
-        v.extend(view::specs());
-        v.extend(viewer_cmds::specs());
-        v.extend(shape_stroke::specs());
-        v.extend(shape_tool::specs());
-        v.extend(focus::specs());
-        v.extend(key_labels::specs());
-        v.extend(key_transform::specs());
-        v.extend(quick_offset::specs());
-        v.extend(file_more::specs());
-        v.extend(relink::specs());
-        v.extend(relink_moved::specs());
-        v.extend(lottie::specs());
-        v.extend(import_project::specs());
-        v.extend(timeline::specs());
-        v.extend(comp_more::specs());
-        v.extend(frame_export::specs());
-        v.extend(watch_folder::specs());
-        v.extend(vpe::specs());
-        v.extend(path_nulls::specs());
-        v.extend(vr_editor::specs());
-        v.extend(frontend::specs());
-        v.extend(track::specs());
-        v.extend(mask_interp::specs());
-        v.extend(warp_cmds::specs());
-        v.extend(camera_cmds::specs());
-        v.extend(roto_cmds::specs());
-        v.extend(paint::specs());
-        v.extend(puppet::specs());
-        v.extend(liquify::specs());
-        v.extend(settings::specs());
-        v.extend(app_more::specs());
-        v.extend(keys_more::specs());
-        v.extend(essential::specs());
-        v.extend(expr_tools::specs());
-        v.extend(proxy::specs());
-        v.extend(scripts::specs());
-        v.extend(panels_cmds::specs());
-        v.extend(footage_panel::specs());
-        v.extend(autotrace::specs());
-        v.extend(scene_detect::specs());
-        v.extend(align_data::specs());
-        v.extend(align::specs());
-        v.extend(content_fill::specs());
-        v.extend(stubs::specs());
-        v.extend(crate::storage::specs());
-        v.extend(crate::learn::specs());
-        v.extend(crate::templates::specs());
-        v.extend(crate::preview::specs());
-        v
-    })
-}
-
-/// Set `footage` as the proxy of `item` (File ▸ Create Proxy's post-render action).
-pub(crate) fn proxy_set(s: &mut Session, item: ItemId, footage: effectcraft_project::Footage) -> Result<()> {
-    proxy::set_proxy_footage(s, &[item], footage)
-}
-
-/// (id, name) of the text animation presets.
-pub fn text_preset_list() -> Vec<(String, String)> {
-    text_anim::preset_names()
-}
-
-/// (id, name, category) of the built-in animation presets (Transitions…).
-pub fn builtin_preset_list() -> Vec<(String, String, String)> {
-    anim_presets::preset_names()
-}
-
-pub fn find(id: &str) -> Option<&'static CommandSpec> {
-    // Every command execution looks its spec up: index the ~2,000 ids once.
-    static INDEX: OnceLock<std::collections::HashMap<&'static str, usize>> = OnceLock::new();
-    let index = INDEX.get_or_init(|| {
-        let mut m = std::collections::HashMap::new();
-        for (i, c) in command_specs().iter().enumerate() {
-            m.entry(c.id).or_insert(i);
-        }
-        m
-    });
-    index.get(id).map(|&i| &command_specs()[i])
-}
-
-// ---------- parameter validation (agents) ----------
-
-/// Top-level keys accepted by a params doc such as `{layers: [id|name|#n], add?, toggle?}` or
-/// `{time? (s) | frame? | timecode?}`; `None` when the doc isn't a `{…}` key list.
-pub fn accepted_params(doc: &str) -> Option<Vec<String>> {
-    let body = doc.trim().strip_prefix('{')?;
-    // Top-level pieces up to the matching close brace, split at `,` and `|`; `:` starts a value.
-    let (mut keys, mut cur, mut depth, mut in_value) = (Vec::new(), String::new(), 0i32, false);
-    let push = |cur: &mut String, keys: &mut Vec<String>| {
-        let k: String = cur.trim().chars().take_while(|c| c.is_ascii_alphanumeric() || *c == '_').collect();
-        if !k.is_empty() && !keys.contains(&k) {
-            keys.push(k);
-        }
-        cur.clear();
-    };
-    for c in body.chars() {
-        match c {
-            '{' | '[' | '(' => depth += 1,
-            ']' | ')' => depth -= 1,
-            '}' if depth == 0 => {
-                push(&mut cur, &mut keys);
-                return Some(keys);
-            }
-            '}' => depth -= 1,
-            ',' if depth == 0 => {
-                push(&mut cur, &mut keys);
-                in_value = false;
-            }
-            '|' if depth == 0 && !in_value => push(&mut cur, &mut keys),
-            ':' if depth == 0 => {
-                push(&mut cur, &mut keys);
-                in_value = true;
-            }
-            _ if depth == 0 && !in_value => cur.push(c),
-            _ => {}
-        }
-    }
-    None
-}
-
-/// Top-level pieces of a params doc (split at depth-0 commas), e.g. `{layer?, path|prop, value}`
-/// → `["layer?", "path|prop", "value"]`.
-fn doc_pieces(doc: &str) -> Option<Vec<String>> {
-    let body = doc.trim().strip_prefix('{')?;
-    let (mut out, mut cur, mut depth) = (Vec::new(), String::new(), 0i32);
-    for c in body.chars() {
-        match c {
-            '{' | '[' | '(' => depth += 1,
-            ']' | ')' => depth -= 1,
-            '}' if depth == 0 => {
-                if !cur.trim().is_empty() {
-                    out.push(cur.trim().to_string());
-                }
-                return Some(out);
-            }
-            '}' => depth -= 1,
-            ',' if depth == 0 => {
-                if !cur.trim().is_empty() {
-                    out.push(cur.trim().to_string());
-                }
-                cur.clear();
-                continue;
-            }
-            _ => {}
-        }
-        cur.push(c);
-    }
-    None
-}
-
-/// The JSON Schema of a command's parameters, derived from its params doc: one property per
-/// accepted key (described by its piece of the doc), no others. MCP `describe_command` and
-/// `list_commands {schemas: true}` serve it.
-pub fn params_schema(spec: &CommandSpec) -> Value {
-    let mut props = serde_json::Map::new();
-    let mut required = vec![];
-    for piece in doc_pieces(spec.params).unwrap_or_default() {
-        let keys = accepted_params(&format!("{{{piece}}}")).unwrap_or_default();
-        let alternatives = keys.len() > 1;
-        for k in keys {
-            // `key?` is optional; so is any key with alternatives (`path|prop`).
-            let optional = alternatives || piece.contains(&format!("{k}?"));
-            if !optional && !required.contains(&k) {
-                required.push(k.clone());
-            }
-            props.insert(k, serde_json::json!({"description": piece}));
-        }
-    }
-    serde_json::json!({
-        "type": "object",
-        "description": spec.params,
-        "properties": props,
-        "required": required,
-        "additionalProperties": accepted_params(spec.params).is_none(),
-    })
-}
-
-/// Keys every command understands (comp targeting, gesture merging) and accepted aliases.
-const ALWAYS_OK: &[&str] = &["comp", "merge"];
-const ALIASES: &[(&str, &str)] = &[("layers", "layer"), ("layer", "layers"), ("time", "frame"), ("frameRate", "fps"), ("properties", "property")];
-
-/// Reject unknown top-level parameters (typos, guessed names) with the list of accepted keys.
-pub fn check_params(spec: &CommandSpec, params: &Value) -> Result<()> {
-    let (Some(obj), Some(accepted)) = (params.as_object(), accepted_params(spec.params)) else { return Ok(()) };
-    let ok = |k: &str| ALWAYS_OK.contains(&k) || accepted.iter().any(|a| a == k || ALIASES.iter().any(|(doc, alias)| doc == a && *alias == k));
-    let unknown: Vec<&str> = obj.keys().map(String::as_str).filter(|k| !ok(k)).collect();
-    if unknown.is_empty() {
-        return Ok(());
-    }
-    let list = if accepted.is_empty() { "none".to_string() } else { accepted.join(", ") };
-    Err(bad(
-        spec.id,
-        format!("unknown parameter(s) {}; accepted: {list} (doc: {})", unknown.iter().map(|k| format!("`{k}`")).collect::<Vec<_>>().join(", "), spec.params),
-    ))
-}
-
-// ---------- enablement ----------
-
-pub fn always(_: &Session) -> std::result::Result<(), String> {
-    Ok(())
-}
-pub(crate) fn has_comp(s: &Session) -> std::result::Result<(), String> {
-    s.active_comp().map(|_| ()).ok_or_else(|| "no composition is open".into())
-}
-pub(crate) fn has_layers(s: &Session) -> std::result::Result<(), String> {
-    has_comp(s)?;
-    if s.state.selected_layers.is_empty() { Err("select a layer first".into()) } else { Ok(()) }
-}
-pub(crate) fn has_keys(s: &Session) -> std::result::Result<(), String> {
-    has_comp(s)?;
-    if s.state.selected_keys.is_empty() { Err("select keyframes first".into()) } else { Ok(()) }
-}
-
-pub(crate) fn has_project_selection(s: &Session) -> std::result::Result<(), String> {
-    if s.state.project_selection.is_empty() { Err("select an item in the Project panel first".into()) } else { Ok(()) }
-}
-
-/// Disabled-command enablement (menu entries whose implementation lands with another milestone;
-/// none are left, kept for future stubs).
-#[allow(dead_code)]
-pub(crate) fn not_yet(_: &Session) -> std::result::Result<(), String> {
-    Err("not available yet in EffectCraft".into())
-}
-
-/// `run` of a not-yet-available command.
-#[allow(dead_code)]
-pub(crate) fn not_yet_run(_: &mut Session, _: &Value) -> Result<Value> {
-    Err(EngineError::Other("not available yet in EffectCraft".into()))
-}
-
-/// Hand a frontend-only command to the UI ([`crate::Event::Frontend`]).
-pub(crate) fn frontend(s: &mut Session, id: &str, p: &Value) -> Result<Value> {
-    s.events.push(crate::Event::Frontend { command: id.to_string(), params: p.clone() });
-    Ok(serde_json::json!({"frontend": id}))
-}
-
-/// Match path of a node (`transform/position`, `effects/#2/blurriness` style with `match#n`
-/// occurrences) so it can be found again on another layer.
-pub fn match_path_of(g: &effectcraft_project::PropGroup, uid: effectcraft_project::Uid) -> Option<String> {
-    for c in &g.children {
-        let nth = g.children.iter().take_while(|x| !std::ptr::eq(*x, c)).filter(|x| x.match_id() == c.match_id()).count() + 1;
-        let seg = if nth == 1 { c.match_id().to_string() } else { format!("{}#{nth}", c.match_id()) };
-        if c.uid() == uid {
-            return Some(seg);
-        }
-        if let effectcraft_project::Node::Group(sub) = c
-            && let Some(rest) = match_path_of(sub, uid)
-        {
-            return Some(format!("{seg}/{rest}"));
-        }
-    }
-    None
-}
-
-/// Turn `effects/<match name>[#n]/<property>` (as [`match_path_of`] writes it) into a uid path on
-/// `l`. Path parsing splits on `.`, which would cut a match name like `ec.control.slider` apart.
-/// Any other path, or an effect that is not on the layer, comes back unchanged.
-pub(crate) fn resolve_effect_path(l: &Layer, path: &str) -> String {
-    let Some((seg, tail)) = path.strip_prefix("effects/").and_then(|r| r.split_once('/')) else { return path.to_string() };
-    let (match_id, nth) = match seg.rsplit_once('#') {
-        Some((m, n)) if !m.is_empty() => match n.parse::<usize>() {
-            Ok(n) if n >= 1 => (m, n),
-            _ => (seg, 1),
-        },
-        _ => (seg, 1),
-    };
-    match l.effects().and_then(|fx| fx.groups().filter(|g| g.match_id == match_id).nth(nth - 1)) {
-        Some(g) => format!("effects/@{}/{tail}", g.uid),
-        None => path.to_string(),
-    }
-}
-
-/// Selected properties (leaves) of the active comp as (layer, uid); selected groups expand to
-/// their properties.
-pub(crate) fn selected_leaf_props(s: &Session) -> Vec<(LayerId, effectcraft_project::Uid)> {
-    let Some(comp) = s.active_comp() else { return vec![] };
-    let mut out = vec![];
-    for (lid, uid) in &s.state.selected_props {
-        let Some(l) = comp.layer(*lid) else { continue };
-        if l.props.find(*uid).is_some() {
-            out.push((*lid, *uid));
-        } else if let Some(g) = l.props.find_group(*uid) {
-            g.walk("", &mut |_, p| out.push((*lid, p.uid)));
-        }
-    }
-    out
-}
-
-// ---------- params ----------
-
-pub(crate) fn bad(cmd: &str, msg: impl Into<String>) -> EngineError {
-    EngineError::BadParams { cmd: cmd.into(), msg: msg.into() }
-}
-pub(crate) fn str_p<'a>(p: &'a Value, k: &str) -> Option<&'a str> {
-    p.get(k).and_then(Value::as_str)
-}
-pub(crate) fn f_p(p: &Value, k: &str) -> Option<f64> {
-    p.get(k).and_then(Value::as_f64)
-}
-pub(crate) fn b_p(p: &Value, k: &str) -> Option<bool> {
-    p.get(k).and_then(Value::as_bool)
-}
-pub(crate) fn merge_p(p: &Value) -> Option<&str> {
-    str_p(p, "merge")
-}
-
-/// `comp`: item id or name (an all-digit string that names no comp is taken as an id, as MCP
-/// clients often send numbers as strings); default the active comp.
-pub(crate) fn comp_id(s: &Session, p: &Value) -> Result<ItemId> {
-    let missing = |v: &Value| EngineError::NoSuchComp(v.to_string());
-    match p.get("comp") {
-        Some(v @ Value::Number(n)) => n.as_u64().map(ItemId).filter(|id| s.project.comp(*id).is_some()).ok_or_else(|| missing(v)),
-        Some(v @ Value::String(name)) => s
-            .project
-            .items
-            .values()
-            .find(|i| &i.name == name && i.as_comp().is_some())
-            .map(|i| i.id)
-            .or_else(|| digits_id(name).map(ItemId).filter(|id| s.project.comp(*id).is_some()))
-            .ok_or_else(|| missing(v)),
-        _ => s.active_comp_id().ok_or(EngineError::NoComp),
-    }
-}
-
-/// An all-ASCII-digit string as a number (`"98"` -> 98); anything else (names, `#n`, signs) is `None`.
-fn digits_id(s: &str) -> Option<u64> {
-    if s.is_empty() || !s.bytes().all(|b| b.is_ascii_digit()) {
-        return None;
-    }
-    s.parse().ok()
-}
-
-/// Resolve a layer reference: id (number), `#n` / index (1-based), or name. An all-digit string
-/// that names no layer is resolved as the number it spells.
-pub(crate) fn resolve_layer(comp: &Comp, v: &Value) -> Option<LayerId> {
-    match v {
-        Value::Number(n) => {
-            let id = n.as_u64()?;
-            if comp.layer(LayerId(id)).is_some() { Some(LayerId(id)) } else { comp.layers.get((id as usize).checked_sub(1)?).map(|l| l.id) }
-        }
-        Value::String(s) => {
-            if let Some(i) = s.strip_prefix('#').and_then(|i| i.parse::<usize>().ok()) {
-                return comp.layers.get(i.checked_sub(1)?).map(|l| l.id);
-            }
-            comp.layers.iter().find(|l| &l.name == s).map(|l| l.id).or_else(|| digits_id(s).and_then(|id| resolve_layer(comp, &Value::from(id))))
-        }
-        _ => None,
-    }
-}
-
-/// `layer` param or the first selected layer.
-pub(crate) fn layer_p(s: &Session, p: &Value, cmd: &str) -> Result<(ItemId, LayerId)> {
-    let cid = comp_id(s, p)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
-    if let Some(v) = p.get("layer") {
-        return resolve_layer(comp, v).map(|l| (cid, l)).ok_or_else(|| bad(cmd, format!("no layer {v}")));
-    }
-    s.state
-        .selected_layers
-        .first()
-        .copied()
-        .filter(|l| comp.layer(*l).is_some())
-        .map(|l| (cid, l))
-        .ok_or_else(|| bad(cmd, "no `layer` given and no layer selected"))
-}
-
-/// `layers` param (array) or the selection.
-pub(crate) fn layers_p(s: &Session, p: &Value) -> Result<(ItemId, Vec<LayerId>)> {
-    let cid = comp_id(s, p)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
-    // Explicit references that match no layer are an error (agents otherwise get a silent no-op).
-    let resolve =
-        |v: &Value| resolve_layer(comp, v).ok_or_else(|| EngineError::Other(format!("no layer {v} (use a layer id, \"#n\" or a name from comp.info)")));
-    if let Some(Value::Array(a)) = p.get("layers") {
-        return Ok((cid, a.iter().map(resolve).collect::<Result<_>>()?));
-    }
-    if let Some(v) = p.get("layer").filter(|v| !v.is_null()) {
-        return Ok((cid, vec![resolve(v)?]));
-    }
-    Ok((cid, s.state.selected_layers.iter().copied().filter(|l| comp.layer(*l).is_some()).collect()))
-}
-
-/// Whether a layer can be picked by the user (Select All, Ctrl+Up/Down, a Timeline click): not
-/// locked, and not hidden by the composition's Hide Shy Layers.
-pub(crate) fn selectable(comp: &Comp, l: &Layer) -> bool {
-    !(l.switches.locked || (comp.hide_shy && l.switches.shy))
-}
-
-/// The layers of `ids` a command may edit: locked layers are left alone, as in After Effects.
-/// An error when every one of them is locked.
-pub(crate) fn unlocked(s: &Session, cid: ItemId, ids: Vec<LayerId>, cmd: &str) -> Result<Vec<LayerId>> {
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
-    let locked = |id: &LayerId| comp.layer(*id).is_some_and(|l| l.switches.locked);
-    match ids.iter().find(|id| locked(id)) {
-        Some(first) if ids.iter().all(locked) => {
-            let name = comp.layer(*first).map(|l| l.name.clone()).unwrap_or_default();
-            Err(bad(cmd, format!("“{name}” is locked (Layer ▸ Switches ▸ Unlock All Layers)")))
-        }
-        _ => Ok(ids.into_iter().filter(|id| !locked(id)).collect()),
-    }
-}
-
-/// `visible: [{layer, prop}]`: the properties the Timeline shows (J / K and Select All
-/// Keyframes use only those, as in After Effects). `None` when not given.
-pub(crate) fn visible_p(p: &Value) -> Option<Vec<(LayerId, effectcraft_project::Uid)>> {
-    let a = p.get("visible")?.as_array()?;
-    Some(a.iter().filter_map(|v| Some((LayerId(v.get("layer")?.as_u64()?), v.get("prop")?.as_u64()?))).collect())
-}
-
-/// `time` (seconds) or `frame` param, else the CTI.
-pub(crate) fn time_p(s: &Session, p: &Value, comp: Option<&Comp>) -> Tick {
-    if let Some(t) = f_p(p, "time") {
-        return Tick::from_seconds_f64(t);
-    }
-    if let (Some(f), Some(c)) = (p.get("frame").and_then(Value::as_i64), comp) {
-        return c.frame_rate.tick_of(f);
-    }
-    s.time()
-}
-
-pub(crate) fn layer_mut(p: &mut effectcraft_project::Project, cid: ItemId, lid: LayerId) -> Result<&mut Layer> {
-    p.comp_mut(cid).ok_or(EngineError::NoComp)?.layer_mut(lid).ok_or(EngineError::Project(effectcraft_project::ProjectError::NoLayer(lid)))
-}
diff --git a/crates/engine/src/doc_state.rs b/crates/engine/src/doc_state.rs
new file mode 100644
index 000000000..954a7d24e
--- /dev/null
+++ b/crates/engine/src/doc_state.rs
@@ -0,0 +1,197 @@
+use super::{Deserialize, ItemId, Layer, LayerId, Serialize, Tick, Uid, commands, mask_track, media_browser, roto, viewer};
+
+/// A keyframe reference: layer, property uid, key time (layer time).
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub struct KeyRef {
+    pub layer: LayerId,
+    pub prop: Uid,
+    pub time: Tick,
+}
+
+/// A keyframe drag in progress (`keys.move` steps sharing a merge key): the selection it
+/// started from and the total offset so far, so every step is applied to the keys as they were
+/// before the drag. A key passed over on the way is never overwritten; only the drop position
+/// counts, as in After Effects.
+#[derive(Clone, Debug)]
+pub struct KeyMove {
+    pub merge: String,
+    pub from: Vec<KeyRef>,
+    pub total: Tick,
+}
+
+/// Keyframes of one property on the keyframe clipboard.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct KeyClip {
+    pub layer: LayerId,
+    /// Match-id path relative to the layer (`transform/position`), portable between layers.
+    pub path: String,
+    /// Keys with times relative to the earliest copied key (layer time).
+    pub keys: Vec<effectcraft_keyframe::Keyframe>,
+}
+
+/// A selected mask vertex: layer, mask group uid, vertex index.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub struct VertexRef {
+    pub layer: LayerId,
+    pub mask: Uid,
+    pub index: usize,
+}
+
+/// One composition's selection. The active comp's copy lives in [`EditorState::selected_layers`]
+/// (and the property, key, and vertex lists); every other comp keeps its own here (#1001).
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
+pub struct CompSelection {
+    pub layers: Vec<LayerId>,
+    pub props: Vec<(LayerId, Uid)>,
+    pub keys: Vec<KeyRef>,
+    pub vertices: Vec<VertexRef>,
+}
+
+impl CompSelection {
+    pub(crate) fn is_empty(&self) -> bool {
+        self.layers.is_empty() && self.props.is_empty() && self.keys.is_empty() && self.vertices.is_empty()
+    }
+}
+
+/// Editing state that commands depend on (headless-relevant, serde for agents).
+#[derive(Clone, Debug, Default, Serialize, Deserialize)]
+pub struct EditorState {
+    pub active_comp: Option<ItemId>,
+    /// Open compositions (viewer/timeline tabs), in tab order.
+    pub open_comps: Vec<ItemId>,
+    /// Compositions that were active before the current one, most recent first (Shift+Esc).
+    #[serde(default)]
+    pub recent_comps: Vec<ItemId>,
+    /// Current time per comp (the CTI).
+    pub times: std::collections::BTreeMap<ItemId, Tick>,
+    /// Layer selection of the active comp. Other comps' selections are in [`Self::comp_selections`].
+    pub selected_layers: Vec<LayerId>,
+    /// Selections of comps that are not active, keyed by comp id (#1001).
+    #[serde(default)]
+    pub comp_selections: std::collections::BTreeMap<ItemId, CompSelection>,
+    /// Selected properties / groups (by uid) of selected layers.
+    pub selected_props: Vec<(LayerId, Uid)>,
+    pub selected_keys: Vec<KeyRef>,
+    pub project_selection: Vec<ItemId>,
+    /// Layer clipboard (serialized layers) and keyframe clipboard.
+    #[serde(skip)]
+    pub clipboard: Vec<Layer>,
+    /// Copied keyframes (times relative to the earliest copied key).
+    #[serde(skip)]
+    pub key_clipboard: Vec<KeyClip>,
+    /// The last copy was keyframes (Paste pastes keys at the CTI).
+    #[serde(skip)]
+    pub clip_is_keys: bool,
+    /// Values of selected unanimated properties (match path, value), copied with Edit ▸ Copy;
+    /// Paste sets the same properties of the selected layers.
+    #[serde(skip)]
+    pub value_clipboard: Vec<(String, effectcraft_keyframe::Value)>,
+    /// Copied effect instances, with comp-time key offsets from the earliest copied key.
+    /// Paste adds them to the selected layers at the destination comp's CTI.
+    #[serde(skip)]
+    pub effect_clipboard: Vec<effectcraft_project::PropGroup>,
+    /// Copied shape items (Edit ▸ Copy with groups, paths, paints or path operations selected in
+    /// a shape layer's Contents); Paste adds them to the selected shape layers.
+    #[serde(skip)]
+    pub contents_clipboard: Vec<effectcraft_project::PropGroup>,
+    /// Selected mask vertices (viewer Selection tool / pen).
+    #[serde(default)]
+    pub selected_vertices: Vec<VertexRef>,
+    pub snapping: bool,
+    /// Tools bar ▸ Snapping options (which features snap, Snap Edges Extended).
+    #[serde(default)]
+    pub snap_features: viewer::SnapFeatures,
+    /// Last applied effect id (Effect ▸ last effect).
+    pub last_effect: Option<String>,
+    /// Viewer region of interest `[x, y, w, h]` in comp pixels (Composition ▸ Crop Comp to Region
+    /// of Interest).
+    #[serde(default)]
+    pub region_of_interest: Option<[f64; 4]>,
+    /// Property-link clipboard (Edit ▸ Copy with Property Links / Copy Expression Only).
+    #[serde(skip)]
+    pub link_clipboard: Option<LinkClip>,
+    /// File ▸ Interpret Footage ▸ Remember Interpretation.
+    #[serde(skip)]
+    pub interpretation: Option<effectcraft_project::Footage>,
+    /// Viewer 3D view per comp (Active Camera / Front / … / Custom View 3 and edited view cameras).
+    #[serde(default)]
+    pub views3d: std::collections::BTreeMap<ItemId, effectcraft_render::three_d::Views3D>,
+    /// Tracker panel ▸ Current Track: (tracked layer, tracker group uid) in the active comp.
+    #[serde(default)]
+    pub current_track: Option<(LayerId, Uid)>,
+    /// Tracker panel ▸ Method in mask mode (Track Mask).
+    #[serde(default)]
+    pub mask_track_method: mask_track::MaskMethod,
+    /// 3D Camera Tracker: the selected track points (ids) in the viewer.
+    #[serde(default)]
+    pub camera_points: Vec<u32>,
+    /// Mask Interpolation panel options.
+    #[serde(default)]
+    pub mask_interp: commands::mask_interp::MaskInterpOptions,
+    /// Paint and Brushes panel options (Brush, Clone Stamp and Eraser tools).
+    #[serde(default)]
+    pub paint: commands::paint::PaintOptions,
+    /// Roto Brush and Refine Edge tool options.
+    #[serde(default)]
+    pub roto: roto::RotoOptions,
+    /// Puppet tool options for new meshes.
+    #[serde(default)]
+    pub puppet: commands::puppet::PuppetOptions,
+    /// The shape tools' and the Pen's options (Tool Creates Shape / Mask, Fill and Stroke).
+    #[serde(default)]
+    pub shape_tool: commands::shape_tool::ShapeTool,
+    /// View ▸ Switch View Layout: 1, 2 or 4 views side by side in the Composition viewer.
+    #[serde(default = "one_view")]
+    pub view_layout: u8,
+    /// View ▸ Switch View Layout ▸ Share View Options (grid, guides… in every view).
+    #[serde(default)]
+    pub share_view_options: bool,
+    /// Layer ▸ Mask ▸ Hide Locked Masks (viewer outlines).
+    #[serde(default)]
+    pub hide_locked_masks: bool,
+    /// On-canvas text editing (Type tool): the edited layer, selection and insertion style.
+    #[serde(default)]
+    pub text_edit: Option<commands::text_edit::TextEdit>,
+    /// Text copied while editing (with its formatting), for Paste / Paste Text Formatting Only.
+    #[serde(skip)]
+    pub text_clipboard: Option<effectcraft_keyframe::TextDoc>,
+    /// Composition viewer display options (Show Channel, exposure, snapshot, Fast Previews).
+    #[serde(default)]
+    pub viewer: commands::viewer_cmds::ViewOptions,
+    /// Essential Graphics panel ▸ Primary composition (`None` = the active comp).
+    #[serde(default)]
+    pub essential_primary: Option<ItemId>,
+    /// Essential Graphics panel ▸ Solo Supported Properties (the timeline shows only properties
+    /// Essential Graphics can expose).
+    #[serde(default)]
+    pub essential_solo: bool,
+    /// File ▸ Watch Folder: the folder being watched for projects to render (frontends call
+    /// `file.watchFolder.poll` periodically while it is set).
+    #[serde(default)]
+    pub watch_folder: Option<String>,
+    /// The Footage panel: the footage shown, its time and In/Out marks (source time).
+    #[serde(default)]
+    pub footage_panel: Option<commands::footage_panel::FootageView>,
+    /// Media Browser: the folder shown and the favourites.
+    #[serde(default)]
+    pub media_browser: media_browser::BrowserState,
+    /// Content-Aware Fill panel settings.
+    #[serde(default)]
+    pub content_fill: commands::content_fill::FillSettings,
+    /// View ▸ Split with New Locked Viewer: the second viewer's comp and 3D view.
+    #[serde(default)]
+    pub locked_viewer: Option<commands::viewer_cmds::LockedViewer>,
+}
+
+fn one_view() -> u8 {
+    1
+}
+
+/// What Copy with Property Links / Copy Expression Only put on the clipboard.
+#[derive(Clone, Debug, PartialEq)]
+pub enum LinkClip {
+    /// Expressions that link back to the source properties: (match path, expression text).
+    Links { relative: bool, links: Vec<(String, String)> },
+    /// Expressions only: (match path, expression).
+    Expressions(Vec<(String, effectcraft_project::Expression)>),
+}
diff --git a/crates/engine/src/error.rs b/crates/engine/src/error.rs
new file mode 100644
index 000000000..75e9e4467
--- /dev/null
+++ b/crates/engine/src/error.rs
@@ -0,0 +1,20 @@
+#[derive(Debug, thiserror::Error)]
+pub enum EngineError {
+    #[error("unknown command `{0}`")]
+    UnknownCommand(String),
+    #[error("command `{0}` is not available right now: {1}")]
+    Disabled(String, String),
+    #[error("invalid parameters for `{cmd}`: {msg}")]
+    BadParams { cmd: String, msg: String },
+    #[error("no active composition")]
+    NoComp,
+    /// A `comp` reference (name or id) that names no composition.
+    #[error("no composition {0}")]
+    NoSuchComp(String),
+    #[error("{0}")]
+    Project(#[from] effectcraft_project::ProjectError),
+    #[error("{0}")]
+    Other(String),
+}
+
+pub type Result<T> = std::result::Result<T, EngineError>;
diff --git a/crates/engine/src/event.rs b/crates/engine/src/event.rs
new file mode 100644
index 000000000..e1f5e0535
--- /dev/null
+++ b/crates/engine/src/event.rs
@@ -0,0 +1,32 @@
+use super::{ItemId, Serialize, Value};
+
+/// Events for frontends (drained each frame).
+#[derive(Clone, Debug, PartialEq, Serialize)]
+pub enum Event {
+    ProjectChanged {
+        revision: u64,
+    },
+    Toast {
+        message: String,
+        error: bool,
+    },
+    OpenComp(ItemId),
+    OpenUrl(String),
+    /// A frontend-only command (viewer zoom, panels, dialogs…) ran: the UI performs it. Headless
+    /// sessions ignore these.
+    Frontend {
+        command: String,
+        params: Value,
+    },
+    /// Drop cached frames / renders (Edit ▸ Purge).
+    PurgeCaches,
+    /// Put an image on the system clipboard (Composition ▸ Copy Frame to Clipboard): `rgba` is
+    /// `width` × `height` straight-alpha RGBA8 rows. Headless sessions ignore it; the pixels are
+    /// not serialized.
+    CopyImage {
+        width: u32,
+        height: u32,
+        #[serde(skip)]
+        rgba: Vec<u8>,
+    },
+}
diff --git a/crates/engine/src/fonts.rs b/crates/engine/src/fonts.rs
new file mode 100644
index 000000000..6b06d6f5b
--- /dev/null
+++ b/crates/engine/src/fonts.rs
@@ -0,0 +1,92 @@
+use super::prefs;
+
+pub fn text_families() -> Vec<String> {
+    effectcraft_text::families().into_iter().map(|(f, _)| f).collect()
+}
+
+/// The styles a family offers (its own faces, in weight order), for the style menus. A family
+/// that isn't installed offers the usual styles, which resolve to Inter's.
+pub fn font_styles(family: &str) -> Vec<String> {
+    effectcraft_text::families()
+        .into_iter()
+        .find(|(f, _)| f.eq_ignore_ascii_case(family))
+        .map(|(_, st)| st)
+        .filter(|st| !st.is_empty())
+        .unwrap_or_else(|| ["Regular", "Medium", "SemiBold", "Bold", "Italic"].iter().map(|s| s.to_string()).collect())
+}
+
+/// The OpenType feature tags (GSUB / GPOS) of the face a family + style resolves to.
+pub fn font_features(family: &str, style: &str) -> Vec<String> {
+    effectcraft_text::fonts::face(effectcraft_text::resolve(family, style).face).features()
+}
+
+/// One row of the Character panel's font menu.
+#[derive(Clone, Debug, PartialEq)]
+pub struct FontRow {
+    /// The family to apply (empty for the separator after the recent fonts).
+    pub family: String,
+    /// What the menu shows: the English family name, or the font's own-language name when
+    /// Settings ▸ Type ▸ Show Font Names in English is off.
+    pub display: String,
+    pub recent: bool,
+    /// A variable font (the menu's Variable Fonts filter keeps only these).
+    pub variable: bool,
+}
+
+/// Outline polylines of "Sample" set in `family` at `size` px (baseline at y = 0, y down), for
+/// the font menu's preview (Settings ▸ Type ▸ Show Font Preview).
+pub fn font_preview(family: &str, size: f64) -> Vec<Vec<[f32; 2]>> {
+    use kurbo::PathEl;
+    let st = effectcraft_keyframe::text_doc::CharStyle { font: family.to_string(), size, ..Default::default() };
+    let mut out = vec![];
+    let mut x = 0.0;
+    for ch in "Sample".chars() {
+        let (path, adv) = effectcraft_text::char_glyph_style(&st, ch);
+        let mut cur: Vec<[f32; 2]> = vec![];
+        let pt = |p: kurbo::Point| [(p.x + x) as f32, p.y as f32];
+        kurbo::flatten(&path, 0.2, |el| match el {
+            PathEl::MoveTo(p) => {
+                if cur.len() > 1 {
+                    out.push(std::mem::take(&mut cur));
+                }
+                cur = vec![pt(p)];
+            }
+            PathEl::LineTo(p) => cur.push(pt(p)),
+            PathEl::ClosePath => {
+                if let Some(f) = cur.first().copied() {
+                    cur.push(f);
+                }
+                if cur.len() > 1 {
+                    out.push(std::mem::take(&mut cur));
+                }
+            }
+            _ => {}
+        });
+        if cur.len() > 1 {
+            out.push(cur);
+        }
+        x += adv;
+    }
+    out
+}
+
+/// The Character panel's font menu: the recent fonts (Settings ▸ Type ▸ Number of Recent Fonts
+/// to Display), a separator, then every family. Each row says whether the family is variable,
+/// for the menu's Variable Fonts filter.
+pub fn font_menu(prefs: &prefs::Prefs) -> Vec<FontRow> {
+    let all = text_families();
+    let native = if prefs.type_.font_names_in_english { Default::default() } else { effectcraft_text::fonts::native_families() };
+    let variable = effectcraft_text::fonts::variable_families();
+    let row = |f: &String, recent: bool| FontRow {
+        family: f.clone(),
+        display: native.get(f).cloned().unwrap_or_else(|| f.clone()),
+        recent,
+        variable: variable.contains(f),
+    };
+    let mut out: Vec<FontRow> = prefs.recent_fonts_shown().iter().filter(|f| all.contains(f)).map(|f| row(f, true)).collect();
+    if !out.is_empty() {
+        out.push(FontRow { family: String::new(), display: "-".into(), recent: false, variable: false });
+    }
+    out.extend(all.iter().map(|f| row(f, false)));
+    out
+}
diff --git a/crates/engine/src/footage.rs b/crates/engine/src/footage.rs
new file mode 100644
index 000000000..21e67d8be
--- /dev/null
+++ b/crates/engine/src/footage.rs
@@ -0,0 +1,6 @@
+pub mod doc_path;
+pub mod footage_check;
+pub mod footage_reload;
+pub mod media_browser;
+pub mod media_cache;
+pub mod sequence;
diff --git a/crates/engine/src/doc_path.rs b/crates/engine/src/footage/doc_path.rs
similarity index 100%
rename from crates/engine/src/doc_path.rs
rename to crates/engine/src/footage/doc_path.rs
diff --git a/crates/engine/src/doc_path/tests.rs b/crates/engine/src/footage/doc_path/tests.rs
similarity index 100%
rename from crates/engine/src/doc_path/tests.rs
rename to crates/engine/src/footage/doc_path/tests.rs
diff --git a/crates/engine/src/footage_check.rs b/crates/engine/src/footage/footage_check.rs
similarity index 100%
rename from crates/engine/src/footage_check.rs
rename to crates/engine/src/footage/footage_check.rs
diff --git a/crates/engine/src/footage_reload.rs b/crates/engine/src/footage/footage_reload.rs
similarity index 100%
rename from crates/engine/src/footage_reload.rs
rename to crates/engine/src/footage/footage_reload.rs
diff --git a/crates/engine/src/media_browser.rs b/crates/engine/src/footage/media_browser.rs
similarity index 100%
rename from crates/engine/src/media_browser.rs
rename to crates/engine/src/footage/media_browser.rs
diff --git a/crates/engine/src/media_cache.rs b/crates/engine/src/footage/media_cache.rs
similarity index 100%
rename from crates/engine/src/media_cache.rs
rename to crates/engine/src/footage/media_cache.rs
diff --git a/crates/engine/src/sequence.rs b/crates/engine/src/footage/sequence.rs
similarity index 100%
rename from crates/engine/src/sequence.rs
rename to crates/engine/src/footage/sequence.rs
diff --git a/crates/engine/src/history.rs b/crates/engine/src/history.rs
index 6e3d928c5..ae314d65d 100644
--- a/crates/engine/src/history.rs
+++ b/crates/engine/src/history.rs
@@ -345,6 +345,7 @@ impl Session {
         let undo: Vec<(String, Arc<Project>)> = (0..k).map(|i| (a.label[new_line[i + 1]].clone(), a.state[new_line[i]].clone())).collect();
         let redo: Vec<(String, Arc<Project>)> = new_line[k + 1..].iter().rev().map(|&i| (a.label[i].clone(), a.state[i].clone())).collect();
         let edited = crate::commands::text_edit::active_editor_snapshot(self);
+        let probe = crate::commands::kept_crypto_probe(self);
         let cur = std::mem::replace(&mut self.project, a.state[target].clone());
         self.keep_view_settings(&cur);
         self.history.undo = undo;
@@ -353,6 +354,7 @@ impl Session {
         self.history.merge_key = None;
         self.sanitize_after_replacement(edited.as_ref());
         self.bump();
+        crate::commands::keep_crypto_probe(self, probe, &cur);
         true
     }
 }
diff --git a/crates/engine/src/home.rs b/crates/engine/src/home.rs
new file mode 100644
index 000000000..183461aa4
--- /dev/null
+++ b/crates/engine/src/home.rs
@@ -0,0 +1,4 @@
+pub mod demo;
+pub mod learn;
+pub mod links;
+pub mod templates;
diff --git a/crates/engine/src/demo.rs b/crates/engine/src/home/demo.rs
similarity index 95%
rename from crates/engine/src/demo.rs
rename to crates/engine/src/home/demo.rs
index df07f5204..656bd7708 100644
--- a/crates/engine/src/demo.rs
+++ b/crates/engine/src/home/demo.rs
@@ -130,8 +130,20 @@ fn solid_sized(p: &mut Project, comp: &Comp, folder: ItemId, name: &str, color:
     build::layer(p, comp, name, LayerSource::Solid { item: sid }, (w, h), None)
 }
 
+/// What `card` draws: name, gradient end colors (hex), size, position and Y rotation.
+#[derive(Clone, Copy)]
+struct CardSpec<'a> {
+    name: &'a str,
+    a: &'a str,
+    b: &'a str,
+    size: (u32, u32),
+    pos: [f64; 3],
+    rot_y: f64,
+}
+
 /// A 3D card: a solid with a diagonal gradient and a thin border grid.
-fn card(p: &mut Project, comp: &Comp, folder: ItemId, name: &str, a: &str, b: &str, size: (u32, u32), pos: [f64; 3], rot_y: f64) -> Layer {
+fn card(p: &mut Project, comp: &Comp, folder: ItemId, spec: &CardSpec) -> Layer {
+    let CardSpec { name, a, b, size, pos, rot_y } = *spec;
     let mut l = solid_sized(p, comp, folder, name, [1.0, 1.0, 1.0], size.0, size.1);
     let (w, h) = (size.0 as f64, size.1 as f64);
     effect(
@@ -192,11 +204,11 @@ fn showcase_3d(p: &mut Project, solids: ItemId) -> Comp {
     set(&mut floor, "materialOptions/specularIntensity", Value::Scalar(10.0));
 
     // Cards at different depths and angles; the centre pair intersects.
-    let left = card(p, &c, solids, "Card Blue", "#2E7BF0", "#7A4DFF", (520, 340), [520.0, 560.0, 120.0], 28.0);
-    let right = card(p, &c, solids, "Card Coral", "#FF6A5C", "#FFB347", (520, 340), [1420.0, 560.0, 260.0], -32.0);
-    let mut x1 = card(p, &c, solids, "Cross A", "#1FD1A5", "#2E7BF0", (460, 460), [960.0, 470.0, 520.0], 40.0);
+    let left = card(p, &c, solids, &CardSpec { name: "Card Blue", a: "#2E7BF0", b: "#7A4DFF", size: (520, 340), pos: [520.0, 560.0, 120.0], rot_y: 28.0 });
+    let right = card(p, &c, solids, &CardSpec { name: "Card Coral", a: "#FF6A5C", b: "#FFB347", size: (520, 340), pos: [1420.0, 560.0, 260.0], rot_y: -32.0 });
+    let mut x1 = card(p, &c, solids, &CardSpec { name: "Cross A", a: "#1FD1A5", b: "#2E7BF0", size: (460, 460), pos: [960.0, 470.0, 520.0], rot_y: 40.0 });
     set(&mut x1, "materialOptions/lightTransmission", Value::Scalar(30.0));
-    let x2 = card(p, &c, solids, "Cross B", "#F0E14A", "#FF6A5C", (460, 460), [960.0, 470.0, 520.0], -40.0);
+    let x2 = card(p, &c, solids, &CardSpec { name: "Cross B", a: "#F0E14A", b: "#FF6A5C", size: (460, 460), pos: [960.0, 470.0, 520.0], rot_y: -40.0 });
     // Hero title in 3D space, gently turning.
     let mut title = text_layer(
         p,
diff --git a/crates/engine/src/learn.rs b/crates/engine/src/home/learn.rs
similarity index 100%
rename from crates/engine/src/learn.rs
rename to crates/engine/src/home/learn.rs
diff --git a/crates/engine/src/links.rs b/crates/engine/src/home/links.rs
similarity index 100%
rename from crates/engine/src/links.rs
rename to crates/engine/src/home/links.rs
diff --git a/crates/engine/src/templates.rs b/crates/engine/src/home/templates.rs
similarity index 100%
rename from crates/engine/src/templates.rs
rename to crates/engine/src/home/templates.rs
diff --git a/crates/engine/src/interchange.rs b/crates/engine/src/interchange.rs
new file mode 100644
index 000000000..ec4cff579
--- /dev/null
+++ b/crates/engine/src/interchange.rs
@@ -0,0 +1,3 @@
+pub mod psd_import;
+pub mod vector;
+pub mod xml_project;
diff --git a/crates/engine/src/psd_import.rs b/crates/engine/src/interchange/psd_import.rs
similarity index 100%
rename from crates/engine/src/psd_import.rs
rename to crates/engine/src/interchange/psd_import.rs
diff --git a/crates/engine/src/vector.rs b/crates/engine/src/interchange/vector.rs
similarity index 100%
rename from crates/engine/src/vector.rs
rename to crates/engine/src/interchange/vector.rs
diff --git a/crates/engine/src/xml_project.rs b/crates/engine/src/interchange/xml_project.rs
similarity index 100%
rename from crates/engine/src/xml_project.rs
rename to crates/engine/src/interchange/xml_project.rs
diff --git a/crates/engine/src/lib.rs b/crates/engine/src/lib.rs
index 3c3cb868d..7be59c277 100644
--- a/crates/engine/src/lib.rs
+++ b/crates/engine/src/lib.rs
@@ -10,45 +10,20 @@
 
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
 
-pub mod autosave;
-pub mod camera_track;
-pub mod commands;
-pub mod config;
-pub mod demo;
-pub mod doc_path;
-pub mod footage_check;
-pub mod footage_reload;
-pub mod guard;
+mod analysis;
+mod background;
+pub mod cmd;
+mod footage;
 pub mod history;
-pub mod jobs;
-pub mod learn;
-pub mod links;
-pub mod logging;
-pub mod mask_track;
-pub mod media_browser;
-pub mod media_cache;
+mod home;
+mod interchange;
 pub mod menus;
-pub mod models;
-pub mod offload;
-pub mod perf;
-pub mod prefs;
 pub mod preview;
-pub mod psd_import;
-pub mod remote;
 pub mod render_queue;
-pub mod roto;
 pub mod scriptui;
-pub mod sequence;
-mod session_settings;
-pub mod shortcuts;
-pub mod storage;
-pub mod sysinfo;
-pub mod templates;
-pub mod tracking;
-pub mod vector;
+mod settings;
+mod system;
 pub mod viewer;
-pub mod warp;
-pub mod xml_project;
 
 use std::sync::Arc;
 
@@ -59,7 +34,17 @@ use effectcraft_time::Tick;
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 
-pub use commands::{CommandSpec, command_specs, find as find_command};
+pub use analysis::camera_track;
+pub use analysis::mask_track;
+pub use analysis::models;
+pub use analysis::roto;
+pub use analysis::tracking;
+pub use analysis::warp;
+pub use background::jobs;
+pub use background::offload;
+pub use background::remote;
+pub use cmd as commands;
+pub use cmd::{CommandSpec, command_specs, find as find_command};
 pub use effectcraft_color as color;
 pub use effectcraft_effects as effects;
 pub use effectcraft_geom as geom;
@@ -71,324 +56,45 @@ pub use effectcraft_segment as segment;
 pub use effectcraft_text as text;
 pub use effectcraft_time as time;
 pub use effectcraft_track as track;
+pub use footage::doc_path;
+pub use footage::footage_check;
+pub use footage::footage_reload;
+pub use footage::media_browser;
+pub use footage::media_cache;
+pub use footage::sequence;
 pub use history::{Branch, History, HistoryNode};
+pub use home::demo;
+pub use home::learn;
+pub use home::links;
+pub use home::templates;
+pub use interchange::psd_import;
+pub use interchange::vector;
+pub use interchange::xml_project;
 pub use render_queue::{ExportJob, ExportResult, Exporter, JobState};
+pub use settings::autosave;
+pub use settings::config;
+pub use settings::prefs;
+pub use settings::shortcuts;
+pub use system::guard;
+pub use system::logging;
+pub use system::perf;
+pub use system::storage;
+pub use system::sysinfo;
 
-#[derive(Debug, thiserror::Error)]
-pub enum EngineError {
-    #[error("unknown command `{0}`")]
-    UnknownCommand(String),
-    #[error("command `{0}` is not available right now: {1}")]
-    Disabled(String, String),
-    #[error("invalid parameters for `{cmd}`: {msg}")]
-    BadParams { cmd: String, msg: String },
-    #[error("no active composition")]
-    NoComp,
-    /// A `comp` reference (name or id) that names no composition.
-    #[error("no composition {0}")]
-    NoSuchComp(String),
-    #[error("{0}")]
-    Project(#[from] effectcraft_project::ProjectError),
-    #[error("{0}")]
-    Other(String),
-}
+mod doc_state;
+mod error;
+mod event;
+mod fonts;
+mod services;
+mod session;
 
-pub type Result<T> = std::result::Result<T, EngineError>;
-
-/// Host services (file access) injected by the frontend.
-pub trait Services: Send + Sync {
-    fn read_file(&self, path: &str) -> std::io::Result<Vec<u8>>;
-    fn write_file(&self, path: &str, data: &[u8]) -> std::io::Result<()>;
-    /// Whether a file exists (the background footage check after open).
-    fn exists(&self, path: &str) -> bool {
-        std::path::Path::new(path).exists()
-    }
-    /// A file's size and modification time (nanoseconds since 1970), to notice that it changed
-    /// on disk (Settings ▸ Import ▸ Reload Footage Changed on Disk); `None` when it can't be read.
-    fn stamp(&self, path: &str) -> Option<(u64, u128)> {
-        let meta = std::fs::metadata(path).ok()?;
-        let modified = meta.modified().ok()?.duration_since(std::time::UNIX_EPOCH).ok()?;
-        Some((meta.len(), modified.as_nanos()))
-    }
-    /// Keep a file the app made for itself (footage extracted from a template): like
-    /// [`Services::write_file`], creating its folder, but never offered as a download (web: it
-    /// goes to browser storage only).
-    fn store_file(&self, path: &str, data: &[u8]) -> std::io::Result<()> {
-        if let Some(d) = std::path::Path::new(path).parent().filter(|d| !d.as_os_str().is_empty()) {
-            let _ = std::fs::create_dir_all(d);
-        }
-        self.write_file(path, data)
-    }
-    /// The files in folder `dir` (full paths; no folders, no hidden files), for image-sequence
-    /// detection on import. Empty when it can't be read.
-    fn list_dir(&self, dir: &str) -> Vec<String> {
-        let Ok(rd) = std::fs::read_dir(if dir.is_empty() { "." } else { dir }) else { return vec![] };
-        rd.filter_map(|e| e.ok())
-            .filter(|e| e.file_type().is_ok_and(|t| t.is_file()) && !e.file_name().to_string_lossy().starts_with('.'))
-            .map(|e| e.path().to_string_lossy().to_string())
-            .collect()
-    }
-    /// Whether `path` is a folder (dropped or picked folders import their files).
-    fn is_dir(&self, path: &str) -> bool {
-        std::path::Path::new(path).is_dir()
-    }
-}
-
-/// Native filesystem.
-pub struct FsServices;
-impl Services for FsServices {
-    fn read_file(&self, path: &str) -> std::io::Result<Vec<u8>> {
-        std::fs::read(path)
-    }
-    fn write_file(&self, path: &str, data: &[u8]) -> std::io::Result<()> {
-        config::atomic_write(std::path::Path::new(path), data)
-    }
-}
-
-/// Imports media files into the project (implemented by the media layer).
-pub trait Importer: Send + Sync {
-    /// Probe one file and return footage metadata. Image sequences are the engine's
-    /// ([`sequence`]): it groups numbered stills and probes their first file here.
-    fn probe(&self, path: &str) -> std::result::Result<effectcraft_project::Footage, String>;
-    /// A footage file's bytes are now at `path` (extracted from a template): hosts whose media
-    /// layer reads from memory (the browser) register them; file-based ones need nothing.
-    fn register(&self, _path: &str, _data: &[u8]) {}
-    /// An image sequence's other frames (its first was probed) are footage now: hosts whose
-    /// media layer reads from memory (the browser) register them; file-based ones need nothing.
-    fn add_frames(&self, _paths: &[String]) {}
-}
-
-/// A keyframe reference: layer, property uid, key time (layer time).
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
-pub struct KeyRef {
-    pub layer: LayerId,
-    pub prop: Uid,
-    pub time: Tick,
-}
-
-/// A keyframe drag in progress (`keys.move` steps sharing a merge key): the selection it
-/// started from and the total offset so far, so every step is applied to the keys as they were
-/// before the drag. A key passed over on the way is never overwritten; only the drop position
-/// counts, as in After Effects.
-#[derive(Clone, Debug)]
-pub struct KeyMove {
-    pub merge: String,
-    pub from: Vec<KeyRef>,
-    pub total: Tick,
-}
-
-/// Keyframes of one property on the keyframe clipboard.
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct KeyClip {
-    pub layer: LayerId,
-    /// Match-id path relative to the layer (`transform/position`), portable between layers.
-    pub path: String,
-    /// Keys with times relative to the earliest copied key (layer time).
-    pub keys: Vec<effectcraft_keyframe::Keyframe>,
-}
-
-/// A selected mask vertex: layer, mask group uid, vertex index.
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
-pub struct VertexRef {
-    pub layer: LayerId,
-    pub mask: Uid,
-    pub index: usize,
-}
-
-/// One composition's selection. The active comp's copy lives in [`EditorState::selected_layers`]
-/// (and the property, key, and vertex lists); every other comp keeps its own here (#1001).
-#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
-pub struct CompSelection {
-    pub layers: Vec<LayerId>,
-    pub props: Vec<(LayerId, Uid)>,
-    pub keys: Vec<KeyRef>,
-    pub vertices: Vec<VertexRef>,
-}
-
-impl CompSelection {
-    fn is_empty(&self) -> bool {
-        self.layers.is_empty() && self.props.is_empty() && self.keys.is_empty() && self.vertices.is_empty()
-    }
-}
-
-/// Editing state that commands depend on (headless-relevant, serde for agents).
-#[derive(Clone, Debug, Default, Serialize, Deserialize)]
-pub struct EditorState {
-    pub active_comp: Option<ItemId>,
-    /// Open compositions (viewer/timeline tabs), in tab order.
-    pub open_comps: Vec<ItemId>,
-    /// Compositions that were active before the current one, most recent first (Shift+Esc).
-    #[serde(default)]
-    pub recent_comps: Vec<ItemId>,
-    /// Current time per comp (the CTI).
-    pub times: std::collections::BTreeMap<ItemId, Tick>,
-    /// Layer selection of the active comp. Other comps' selections are in [`Self::comp_selections`].
-    pub selected_layers: Vec<LayerId>,
-    /// Selections of comps that are not active, keyed by comp id (#1001).
-    #[serde(default)]
-    pub comp_selections: std::collections::BTreeMap<ItemId, CompSelection>,
-    /// Selected properties / groups (by uid) of selected layers.
-    pub selected_props: Vec<(LayerId, Uid)>,
-    pub selected_keys: Vec<KeyRef>,
-    pub project_selection: Vec<ItemId>,
-    /// Layer clipboard (serialized layers) and keyframe clipboard.
-    #[serde(skip)]
-    pub clipboard: Vec<Layer>,
-    /// Copied keyframes (times relative to the earliest copied key).
-    #[serde(skip)]
-    pub key_clipboard: Vec<KeyClip>,
-    /// The last copy was keyframes (Paste pastes keys at the CTI).
-    #[serde(skip)]
-    pub clip_is_keys: bool,
-    /// Values of selected unanimated properties (match path, value), copied with Edit ▸ Copy;
-    /// Paste sets the same properties of the selected layers.
-    #[serde(skip)]
-    pub value_clipboard: Vec<(String, effectcraft_keyframe::Value)>,
-    /// Copied effect instances, with comp-time key offsets from the earliest copied key.
-    /// Paste adds them to the selected layers at the destination comp's CTI.
-    #[serde(skip)]
-    pub effect_clipboard: Vec<effectcraft_project::PropGroup>,
-    /// Copied shape items (Edit ▸ Copy with groups, paths, paints or path operations selected in
-    /// a shape layer's Contents); Paste adds them to the selected shape layers.
-    #[serde(skip)]
-    pub contents_clipboard: Vec<effectcraft_project::PropGroup>,
-    /// Selected mask vertices (viewer Selection tool / pen).
-    #[serde(default)]
-    pub selected_vertices: Vec<VertexRef>,
-    pub snapping: bool,
-    /// Tools bar ▸ Snapping options (which features snap, Snap Edges Extended).
-    #[serde(default)]
-    pub snap_features: viewer::SnapFeatures,
-    /// Last applied effect id (Effect ▸ last effect).
-    pub last_effect: Option<String>,
-    /// Viewer region of interest `[x, y, w, h]` in comp pixels (Composition ▸ Crop Comp to Region
-    /// of Interest).
-    #[serde(default)]
-    pub region_of_interest: Option<[f64; 4]>,
-    /// Property-link clipboard (Edit ▸ Copy with Property Links / Copy Expression Only).
-    #[serde(skip)]
-    pub link_clipboard: Option<LinkClip>,
-    /// File ▸ Interpret Footage ▸ Remember Interpretation.
-    #[serde(skip)]
-    pub interpretation: Option<effectcraft_project::Footage>,
-    /// Viewer 3D view per comp (Active Camera / Front / … / Custom View 3 and edited view cameras).
-    #[serde(default)]
-    pub views3d: std::collections::BTreeMap<ItemId, effectcraft_render::three_d::Views3D>,
-    /// Tracker panel ▸ Current Track: (tracked layer, tracker group uid) in the active comp.
-    #[serde(default)]
-    pub current_track: Option<(LayerId, Uid)>,
-    /// Tracker panel ▸ Method in mask mode (Track Mask).
-    #[serde(default)]
-    pub mask_track_method: mask_track::MaskMethod,
-    /// 3D Camera Tracker: the selected track points (ids) in the viewer.
-    #[serde(default)]
-    pub camera_points: Vec<u32>,
-    /// Mask Interpolation panel options.
-    #[serde(default)]
-    pub mask_interp: commands::mask_interp::MaskInterpOptions,
-    /// Paint and Brushes panel options (Brush, Clone Stamp and Eraser tools).
-    #[serde(default)]
-    pub paint: commands::paint::PaintOptions,
-    /// Roto Brush and Refine Edge tool options.
-    #[serde(default)]
-    pub roto: roto::RotoOptions,
-    /// Puppet tool options for new meshes.
-    #[serde(default)]
-    pub puppet: commands::puppet::PuppetOptions,
-    /// The shape tools' and the Pen's options (Tool Creates Shape / Mask, Fill and Stroke).
-    #[serde(default)]
-    pub shape_tool: commands::shape_tool::ShapeTool,
-    /// View ▸ Switch View Layout: 1, 2 or 4 views side by side in the Composition viewer.
-    #[serde(default = "one_view")]
-    pub view_layout: u8,
-    /// View ▸ Switch View Layout ▸ Share View Options (grid, guides… in every view).
-    #[serde(default)]
-    pub share_view_options: bool,
-    /// Layer ▸ Mask ▸ Hide Locked Masks (viewer outlines).
-    #[serde(default)]
-    pub hide_locked_masks: bool,
-    /// On-canvas text editing (Type tool): the edited layer, selection and insertion style.
-    #[serde(default)]
-    pub text_edit: Option<commands::text_edit::TextEdit>,
-    /// Text copied while editing (with its formatting), for Paste / Paste Text Formatting Only.
-    #[serde(skip)]
-    pub text_clipboard: Option<effectcraft_keyframe::TextDoc>,
-    /// Composition viewer display options (Show Channel, exposure, snapshot, Fast Previews).
-    #[serde(default)]
-    pub viewer: commands::viewer_cmds::ViewOptions,
-    /// Essential Graphics panel ▸ Primary composition (`None` = the active comp).
-    #[serde(default)]
-    pub essential_primary: Option<ItemId>,
-    /// Essential Graphics panel ▸ Solo Supported Properties (the timeline shows only properties
-    /// Essential Graphics can expose).
-    #[serde(default)]
-    pub essential_solo: bool,
-    /// File ▸ Watch Folder: the folder being watched for projects to render (frontends call
-    /// `file.watchFolder.poll` periodically while it is set).
-    #[serde(default)]
-    pub watch_folder: Option<String>,
-    /// The Footage panel: the footage shown, its time and In/Out marks (source time).
-    #[serde(default)]
-    pub footage_panel: Option<commands::footage_panel::FootageView>,
-    /// Media Browser: the folder shown and the favourites.
-    #[serde(default)]
-    pub media_browser: media_browser::BrowserState,
-    /// Content-Aware Fill panel settings.
-    #[serde(default)]
-    pub content_fill: commands::content_fill::FillSettings,
-    /// View ▸ Split with New Locked Viewer: the second viewer's comp and 3D view.
-    #[serde(default)]
-    pub locked_viewer: Option<commands::viewer_cmds::LockedViewer>,
-}
-
-fn one_view() -> u8 {
-    1
-}
-
-/// `t` as a current time of `comp`: a frame within its duration.
-fn comp_frame_at(comp: &Comp, t: Tick) -> Tick {
-    comp.frame_rate.snap_nearest(t.min(comp.duration - comp.frame_duration()).max(Tick::ZERO))
-}
-
-/// What Copy with Property Links / Copy Expression Only put on the clipboard.
-#[derive(Clone, Debug, PartialEq)]
-pub enum LinkClip {
-    /// Expressions that link back to the source properties: (match path, expression text).
-    Links { relative: bool, links: Vec<(String, String)> },
-    /// Expressions only: (match path, expression).
-    Expressions(Vec<(String, effectcraft_project::Expression)>),
-}
-
-/// Events for frontends (drained each frame).
-#[derive(Clone, Debug, PartialEq, Serialize)]
-pub enum Event {
-    ProjectChanged {
-        revision: u64,
-    },
-    Toast {
-        message: String,
-        error: bool,
-    },
-    OpenComp(ItemId),
-    OpenUrl(String),
-    /// A frontend-only command (viewer zoom, panels, dialogs…) ran: the UI performs it. Headless
-    /// sessions ignore these.
-    Frontend {
-        command: String,
-        params: Value,
-    },
-    /// Drop cached frames / renders (Edit ▸ Purge).
-    PurgeCaches,
-    /// Put an image on the system clipboard (Composition ▸ Copy Frame to Clipboard): `rgba` is
-    /// `width` × `height` straight-alpha RGBA8 rows. Headless sessions ignore it; the pixels are
-    /// not serialized.
-    CopyImage {
-        width: u32,
-        height: u32,
-        #[serde(skip)]
-        rgba: Vec<u8>,
-    },
-}
+pub use cmd::{animation_presets, text_presets};
+pub use doc_state::{CompSelection, EditorState, KeyClip, KeyMove, KeyRef, LinkClip, VertexRef};
+pub use error::{EngineError, Result};
+pub use event::Event;
+pub use fonts::{FontRow, font_features, font_menu, font_preview, font_styles, text_families};
+pub use services::{FsServices, Importer, Services};
+pub use session::upgrade_effects;
 
 pub struct Session {
     pub project: Arc<Project>,
@@ -456,6 +162,10 @@ pub struct Session {
     pub journal: Vec<(String, Value)>,
     /// Processed-layer pixels reused across frames and edits (content-keyed, never stale).
     pub layer_cache: Arc<LayerCache>,
+    /// The last Cryptomatte pick probe (see [`Session::crypto_probe_job`]). Public only so that
+    /// other crates can build a `Session { .. }`; its type is crate-private.
+    #[doc(hidden)]
+    pub crypto_probe: Arc<std::sync::Mutex<commands::CryptoProbeSlot>>,
     /// The persistent disk cache (Settings ▸ Media & Disk Cache), when enabled.
     pub disk_cache: Option<Arc<effectcraft_render::disk_cache::DiskCache>>,
     /// Settings (Preferences).
@@ -496,6 +206,8 @@ pub struct Session {
     pub key_move: Option<KeyMove>,
     /// Reads the system's memory in the background for [`Session::memory_tick`].
     pub memory_watch: sysinfo::MemoryWatch,
+    /// Reads the disk cache's free disk space in the background for [`Session::memory_tick`].
+    pub disk_watch: sysinfo::DiskWatch,
     /// Switches Affect Nested Comps as last applied (a change empties the layer cache).
     pub applied_nested_switches: Option<bool>,
     /// Runs renders and analyses off the UI thread where there are no threads (the web app's
@@ -604,6 +316,7 @@ impl Default for Session {
             events: vec![],
             journal: vec![],
             layer_cache: Arc::new(LayerCache::default()),
+            crypto_probe: Default::default(),
             disk_cache: None,
             prefs: prefs::Prefs::default(),
             prefs_revision: 0,
@@ -621,6 +334,7 @@ impl Default for Session {
             sys_memory: None,
             key_move: None,
             memory_watch: Default::default(),
+            disk_watch: Default::default(),
             applied_nested_switches: None,
             offload: None,
             offloaded: vec![],
@@ -642,952 +356,7 @@ impl Default for Session {
     }
 }
 
-impl Session {
-    pub fn new() -> Session {
-        Session::default()
-    }
-
-    /// Run a command by id.
-    pub fn execute(&mut self, id: &str, params: Value) -> Result<Value> {
-        let spec = commands::find(id).ok_or_else(|| EngineError::UnknownCommand(id.to_string()))?;
-        if let Err(why) = (spec.enabled)(self) {
-            // Explicit targets (agents, scripts) don't need a UI selection.
-            let explicit = (["layer", "layers", "prop", "keys"].iter().any(|k| params.get(k).is_some()) && commands::has_comp(self).is_ok())
-                || ["item", "items"].iter().any(|k| params.get(k).is_some())
-                // An explicit composition (the enablement looks at the active one).
-                || params.get("comp").is_some_and(|c| !c.is_null() && self.resolve_comp(Some(c)).is_ok());
-            if !explicit {
-                return Err(EngineError::Disabled(id.to_string(), why));
-            }
-        }
-        // Last-resort guard: a panicking command reports an error instead of crashing the app.
-        let r = guard::guarded(&format!("command `{id}`"), || (spec.run)(self, &params))?;
-        self.learn_observe(id, &params);
-        if spec.journal {
-            self.journal.push((id.to_string(), params));
-            if self.journal.len() > 10_000 {
-                self.journal.drain(..1000);
-            }
-        }
-        Ok(r)
-    }
-
-    /// [`Session::execute`] for agents and scripts (MCP, CLI, control channel): unknown top-level
-    /// parameters are rejected with the accepted keys instead of being silently ignored.
-    pub fn execute_checked(&mut self, id: &str, params: Value) -> Result<Value> {
-        let spec = commands::find(id).ok_or_else(|| EngineError::UnknownCommand(id.to_string()))?;
-        commands::check_params(spec, &params)?;
-        self.execute(id, params)
-    }
-
-    /// [`Session::execute`] for a command a script asked for (the JavaScript engine's
-    /// `app.run`, ScriptUI callbacks…). The command and everything it runs count as the script's:
-    /// it may not change the settings that limit scripts (Settings ▸ Scripting & Expressions ▸
-    /// Application Scripting), which only the user can, from the UI, CLI or control channel.
-    pub fn execute_for_script(&mut self, id: &str, params: Value) -> Result<Value> {
-        self.script_calls.0 = self.script_calls.0.saturating_add(1);
-        let r = self.execute(id, params);
-        self.script_calls.0 = self.script_calls.0.saturating_sub(1);
-        r
-    }
-
-    /// Whether the command running was issued by a script ([`Session::execute_for_script`]).
-    pub fn running_for_script(&self) -> bool {
-        self.script_calls.0 > 0
-    }
-
-    /// Whether `id` names a known command whose `enabled` predicate returns `Ok` for this session;
-    /// an unknown id or a predicate error reads as disabled.
-    pub fn is_enabled(&self, id: &str) -> bool {
-        commands::find(id).is_some_and(|c| (c.enabled)(self).is_ok())
-    }
-
-    /// Apply an undoable edit. `merge`: consecutive edits with the same key fold into one step.
-    ///
-    /// Every edit is an external boundary for the on-canvas text editor: if it replaced the
-    /// document the editor is showing, the selection is clamped and the editor gets a fresh IME
-    /// epoch. The editor's own typing goes through `edit_text_doc`, which owns that
-    /// document and must not treat its own keystrokes as a replacement.
-    pub fn edit<T>(&mut self, label: &str, merge: Option<&str>, f: impl FnOnce(&mut Project, &mut EditorState) -> Result<T>) -> Result<T> {
-        let edited = commands::text_edit::active_editor_snapshot(self);
-        let out = self.edit_inner(label, merge, f)?;
-        commands::text_edit::after_external_change(self, edited.as_ref());
-        Ok(out)
-    }
-
-    /// [`Session::edit`] for the on-canvas editor's own text changes. Its document is the one
-    /// the editor owns, so a change here is typing, not a replacement behind the IME's back.
-    pub(crate) fn edit_text_doc<T>(&mut self, label: &str, merge: Option<&str>, f: impl FnOnce(&mut Project, &mut EditorState) -> Result<T>) -> Result<T> {
-        self.edit_inner(label, merge, f)
-    }
-
-    /// The shared body of [`Session::edit`] and [`Session::edit_text_doc`].
-    ///
-    /// Runs `f` on a clone of the project and editor state, then synchronizes derived data (global
-    /// light and Essential Graphics), queues invalidated Warp Stabilizer/camera-tracker work and
-    /// Roto Brush instances needing re-propagation in the `*_pending` lists. If the clone has the same
-    /// content the project and history are left as they were (only editor-state changes from `f`
-    /// are kept) and no revision is bumped; otherwise the previous project is recorded as an
-    /// undo step under `label`, unless it merges with the current merge key (then the redo branch
-    /// is dropped). An `Err` from `f` propagates with the session unchanged.
-    fn edit_inner<T>(&mut self, label: &str, merge: Option<&str>, f: impl FnOnce(&mut Project, &mut EditorState) -> Result<T>) -> Result<T> {
-        let before = self.project.clone();
-        let mut p = (*self.project).clone();
-        let mut st = self.state.clone();
-        let r = f(&mut p, &mut st)?;
-        // Layer styles: one Global Light per comp, whichever layer edited it.
-        effectcraft_project::styles::sync_global_light(&before, &mut p);
-        // Essential Properties of precomp layers follow their comps' Essential Graphics.
-        effectcraft_project::essential::sync_project(&before, &mut p);
-        // Warp Stabilizer analyses made from other frames are cleared (and queued again).
-        for w in warp::invalidate(&before, &mut p) {
-            if !self.warp_pending.contains(&w) {
-                self.warp_pending.push(w);
-            }
-        }
-        // So are 3D Camera Tracker tracks (and solves made with other settings).
-        for w in camera_track::invalidate(&before, &mut p) {
-            if !self.camera_pending.contains(&w) {
-                self.camera_pending.push(w);
-            }
-        }
-        // Roto Brush Input Keys follow the frames; edited instances propagate again.
-        for r in roto::sync(&before, &mut p) {
-            if !self.roto_pending.contains(&r) {
-                self.roto_pending.push(r);
-            }
-        }
-        // Nothing changed (a value set to what it already was): no undo step, not modified.
-        if p.same_content(&before) {
-            self.state = st;
-            return Ok(r);
-        }
-        let same = merge.is_some() && merge.map(str::to_string) == self.history.merge_key;
-        if !same {
-            // Undone steps aren't lost: they stay in the History panel as a branch.
-            let levels = self.prefs.general.undo_levels.max(1) as usize;
-            self.history.record(label, before, levels);
-        } else {
-            self.history.abandon_redo(&before);
-        }
-        self.history.merge_key = merge.map(str::to_string);
-        self.project = Arc::new(p);
-        self.state = st;
-        self.bump();
-        Ok(r)
-    }
-
-    /// Note a change to the on-canvas editor's committed text or session.
-    ///
-    /// Frontends compare this with [`commands::text_edit::ime_stamp_revision`]; an unrelated
-    /// project change must not advance it.
-    pub(crate) fn note_text_edit_change(&mut self) {
-        // Checked process-wide allocation: a stamp is never wrapped or reused. On exhaustion
-        // keep the previous value; an unavailable before/after pair then compares equal and
-        // earns no receipt instead of accepting a stale revision.
-        if let Some(revision) = commands::text_edit::next_ime_revision() {
-            self.ime_revision = self.ime_revision.max(revision);
-        }
-    }
-
-    pub fn bump(&mut self) {
-        self.revision += 1;
-        // Back at the saved state (undo, redo, a history jump or a rolled-back batch).
-        if Arc::ptr_eq(&self.project, &self.saved_project) {
-            self.saved_revision = self.revision;
-        }
-        self.refresh_disk_salt(false);
-        self.events.push(Event::ProjectChanged { revision: self.revision });
-    }
-
-    /// Salt the disk cache's layer keys with the project's footage files
-    /// ([`effectcraft_render::disk_cache::footage_salt`]). Taking it reads the size and time of
-    /// every file, every frame of an image sequence included, so it is taken again only when the
-    /// footage items changed, or with `force` (a project opened, footage reloaded, the disk cache
-    /// attached), not at every edit: with a few large sequences that cost each keystroke in a
-    /// text field over half a second (#1926).
-    pub fn refresh_disk_salt(&mut self, force: bool) -> Option<u64> {
-        use std::hash::{Hash, Hasher};
-        if self.disk_cache.is_none() {
-            self.disk_salt = None;
-            return None;
-        }
-        let mut h = std::collections::hash_map::DefaultHasher::new();
-        for (id, it) in &self.project.items {
-            if let effectcraft_project::ItemKind::Footage(f) = &it.kind {
-                id.hash(&mut h);
-                format!("{f:?}").hash(&mut h);
-            }
-        }
-        let footage = h.finish();
-        if let Some((seen, salt)) = self.disk_salt
-            && seen == footage
-            && !force
-        {
-            return Some(salt);
-        }
-        let salt = effectcraft_render::disk_cache::footage_salt(&self.project);
-        self.disk_salt = Some((footage, salt));
-        self.layer_cache.set_disk_salt(salt);
-        Some(salt)
-    }
-
-    /// Set a comp's Resolution. As in After Effects it is saved with the project (which becomes
-    /// modified) but is no undo step, and it changes no pixels: the comp's cached frames stay
-    /// valid ([`effectcraft_project::Comp::same_pixels`]).
-    pub fn set_resolution(&mut self, comp: ItemId, r: effectcraft_project::Resolution) -> Result<()> {
-        if self.project.comp(comp).ok_or(EngineError::NoComp)?.resolution == r {
-            return Ok(());
-        }
-        Arc::make_mut(&mut self.project).comp_mut(comp).ok_or(EngineError::NoComp)?.resolution = r;
-        self.bump();
-        Ok(())
-    }
-
-    /// Keep what lives outside the undo history (each comp's Resolution) as it is in `from`, the
-    /// project before undo, redo or a history jump restored another state.
-    pub(crate) fn keep_view_settings(&mut self, from: &Project) {
-        let keep: Vec<(ItemId, effectcraft_project::Resolution)> =
-            self.project.comps().filter_map(|(id, c)| from.comp(*id).map(|f| (*id, f.resolution)).filter(|(_, r)| *r != c.resolution)).collect();
-        if keep.is_empty() {
-            return;
-        }
-        let p = Arc::make_mut(&mut self.project);
-        for (id, r) in keep {
-            if let Some(c) = p.comp_mut(id) {
-                c.resolution = r;
-            }
-        }
-    }
-
-    /// Undoes one step: the current project goes onto the redo stack, per-comp Resolution is kept
-    /// as it was, the merge key is cleared, selections are sanitized for the replaced state (the
-    /// on-canvas editor gets a new IME epoch only when its own document changed) and the session is
-    /// bumped. Returns `false`, changing nothing, when there is nothing to undo.
-    pub fn undo(&mut self) -> bool {
-        let Some((label, p)) = self.history.undo.pop() else { return false };
-        let edited = commands::text_edit::active_editor_snapshot(self);
-        let cur = std::mem::replace(&mut self.project, p);
-        self.keep_view_settings(&cur);
-        self.history.redo.push((label, cur));
-        self.history.merge_key = None;
-        self.sanitize_after_replacement(edited.as_ref());
-        self.bump();
-        true
-    }
-
-    /// Redoes one step: the current project goes back onto the undo stack, per-comp Resolution is
-    /// kept, the merge key is cleared, selections are sanitized for the replaced state (a changed
-    /// text document starts a new IME epoch) and the session is bumped. Returns `false`, changing
-    /// nothing, when there is nothing to redo.
-    pub fn redo(&mut self) -> bool {
-        let Some((label, p)) = self.history.redo.pop() else { return false };
-        let edited = commands::text_edit::active_editor_snapshot(self);
-        let cur = std::mem::replace(&mut self.project, p);
-        self.keep_view_settings(&cur);
-        self.history.undo.push((label, cur));
-        self.history.merge_key = None;
-        self.sanitize_after_replacement(edited.as_ref());
-        self.bump();
-        true
-    }
-
-    /// Keep selections valid after the project was replaced by another state (undo, redo, a
-    /// history jump, a rollback): the same layer id can name a different document, so the
-    /// on-canvas editor gets a fresh IME epoch only when its own document changed.
-    ///
-    /// Normally `before` is [`commands::text_edit::active_editor_snapshot`] taken from the
-    /// state this call is about to replace. Atomic batch rollback is the exception: it has
-    /// already restored the pre-batch state and passes the snapshot of the failing intermediate
-    /// state, so a transient restart or component switch inside the batch still rejects reviving
-    /// the old composition. A restored state that still has the same composition, layer and
-    /// editor session and shows byte/style-equivalent text (an opacity or other property undo)
-    /// keeps the editor's owner and selection; a different document, comp, layer or session clamps the
-    /// selection and starts a new epoch. A closed editor stays closed, and a fallback comp's
-    /// matching layer id never inherits the old comp's session. `None` means no editor was open
-    /// when the snapshot was taken; if one is open after the replacement it is treated as an
-    /// unverified document replacement, so it never inherits an old composition.
-    pub fn sanitize_after_replacement(&mut self, before: Option<&commands::text_edit::EditorSnapshot>) {
-        self.sanitize_state();
-        commands::text_edit::after_replacement(self, before);
-    }
-
-    /// Drop selections that no longer exist. Each comp keeps its own selection (#1001); a layer id
-    /// counts only inside the comp that owns it, so the active comp never sees another comp's layers.
-    pub fn sanitize_state(&mut self) {
-        let p = self.project.clone();
-        self.state.open_comps.retain(|c| p.comp(*c).is_some());
-        self.state.comp_selections.retain(|cid, sel| {
-            let Some(c) = p.comp(*cid) else { return false };
-            let ids: Vec<LayerId> = c.layers.iter().map(|l| l.id).collect();
-            sel.layers.retain(|l| ids.contains(l));
-            sel.props.retain(|(l, _)| ids.contains(l));
-            sel.keys.retain(|k| ids.contains(&k.layer));
-            sel.vertices.retain(|v| ids.contains(&v.layer));
-            !sel.is_empty()
-        });
-        if self.state.active_comp.is_some_and(|c| p.comp(c).is_none()) {
-            self.clear_live_selection();
-            // A matching layer id in the fallback comp is not the document being edited.
-            self.state.text_edit = None;
-            self.state.active_comp = self.state.open_comps.first().copied();
-            if let Some(id) = self.state.active_comp {
-                self.recall_selection(id);
-            }
-        }
-        if let Some(c) = self.active_comp() {
-            let ids: Vec<LayerId> = c.layers.iter().map(|l| l.id).collect();
-            self.state.selected_layers.retain(|l| ids.contains(l));
-            self.state.selected_props.retain(|(l, _)| ids.contains(l));
-            self.state.selected_keys.retain(|k| ids.contains(&k.layer));
-            self.state.selected_vertices.retain(|v| ids.contains(&v.layer));
-        }
-        if let Some((l, t)) = self.state.current_track
-            && self.active_comp().and_then(|c| c.layer(l)).and_then(|l| l.tracker(t)).is_none()
-        {
-            self.state.current_track = None;
-        }
-        self.state.project_selection.retain(|i| p.item(*i).is_some());
-        commands::text_edit::sanitize(self);
-    }
-
-    pub fn is_dirty(&self) -> bool {
-        self.revision != self.saved_revision
-    }
-
-    /// The project as it is now is the saved one (after opening or saving it).
-    pub fn mark_saved(&mut self) {
-        self.saved_project = self.project.clone();
-        self.saved_revision = self.revision;
-    }
-
-    /// The project has changes its file doesn't (a session restored with unsaved changes): it
-    /// stays modified until it is saved, whatever is undone.
-    pub fn mark_unsaved(&mut self) {
-        self.saved_project = Arc::new(Project::default());
-        self.bump();
-    }
-
-    pub fn active_comp(&self) -> Option<&Comp> {
-        self.project.comp(self.state.active_comp?)
-    }
-    /// [`Session::active_comp`] as a shared snapshot (an `Arc` clone, not a deep copy).
-    pub fn active_comp_arc(&self) -> Option<std::sync::Arc<Comp>> {
-        self.project.comp_arc(self.state.active_comp?)
-    }
-    pub fn active_comp_id(&self) -> Option<ItemId> {
-        self.state.active_comp.filter(|c| self.project.comp(*c).is_some())
-    }
-
-    /// Current time of a comp.
-    pub fn time_of(&self, comp: ItemId) -> Tick {
-        self.state.times.get(&comp).copied().unwrap_or(Tick::ZERO)
-    }
-
-    /// Current time of the active comp.
-    pub fn time(&self) -> Tick {
-        self.state.active_comp.and_then(|c| self.state.times.get(&c).copied()).unwrap_or(Tick::ZERO)
-    }
-
-    /// Move the active comp's current time.
-    ///
-    /// Time is an external boundary for the on-canvas text editor too: an animated Source Text
-    /// can show a different document at another time. The document is snapshotted only while an
-    /// editor is open, so playback with no text editor does no text copying.
-    pub fn set_time(&mut self, t: Tick) {
-        if let Some(c) = self.state.active_comp {
-            let t = self.project.comp(c).map_or(t, |comp| comp_frame_at(comp, t));
-            let edited = commands::text_edit::active_editor_snapshot(self);
-            self.state.times.insert(c, t);
-            if self.prefs.general.sync_time_related_items {
-                // Direct call: this `set_time` owns the editor snapshot for both time changes,
-                // so a synced move does not take a second snapshot or start a second epoch.
-                self.sync_related_times_inner(c, t);
-            }
-            commands::text_edit::after_external_change(self, edited.as_ref());
-        }
-    }
-
-    /// Settings ▸ General ▸ Synchronize Time of All Related Items: moving the current time of
-    /// `comp` moves the current time of the comps nested in it (through their precomp layers'
-    /// timing) and of the comps it is nested in, so every related viewer shows the same moment.
-    pub fn sync_related_times(&mut self, comp: ItemId, t: Tick) {
-        // Moving a related comp can move the active one, so the editor's document is checked
-        // here too; the snapshot is skipped entirely when no text editor is open.
-        let edited = commands::text_edit::active_editor_snapshot(self);
-        self.sync_related_times_inner(comp, t);
-        commands::text_edit::after_external_change(self, edited.as_ref());
-    }
-
-    /// Sets the time of every comp related to `comp` through precomp layers: down into the comps
-    /// it nests (through each layer's timing) and up into the comps nesting it. A seen-set keeps
-    /// cycles and diamonds finite; each found time is clamped to its comp's last frame, snapped to
-    /// the nearest frame and stored in `state.times`. The caller owns the text-editor boundary.
-    fn sync_related_times_inner(&mut self, comp: ItemId, t: Tick) {
-        let mut seen = std::collections::BTreeSet::from([comp]);
-        let mut todo = vec![(comp, t)];
-        let mut found = vec![];
-        while let Some((cid, ct)) = todo.pop() {
-            if cid != comp {
-                found.push((cid, ct));
-            }
-            let Some(c) = self.project.comp(cid) else { continue };
-            // Down: the comps this one nests.
-            for l in &c.layers {
-                if let effectcraft_project::LayerSource::Comp { item } = &l.source
-                    && seen.insert(*item)
-                {
-                    todo.push((*item, l.layer_time(ct)));
-                }
-            }
-            // Up: the comps nesting this one.
-            for iid in self.project.items.keys() {
-                if let Some(pc) = self.project.comp(*iid)
-                    && let Some(l) = pc.layers.iter().find(|l| matches!(&l.source, effectcraft_project::LayerSource::Comp { item } if *item == cid))
-                    && seen.insert(*iid)
-                {
-                    todo.push((*iid, l.comp_time(ct)));
-                }
-            }
-        }
-        for (cid, ct) in found {
-            if let Some(c) = self.project.comp(cid) {
-                let ct = c.frame_rate.snap_nearest(ct.clamp(Tick::ZERO, (c.duration - c.frame_duration()).max(Tick::ZERO)));
-                self.state.times.insert(cid, ct);
-            }
-        }
-    }
-
-    /// Make `id` the active comp, parking the previous comp's selection and restoring this one's.
-    pub fn activate_comp(&mut self, id: ItemId) {
-        if self.project.comp(id).is_none() || self.state.active_comp == Some(id) {
-            return;
-        }
-        self.remember_selection();
-        self.state.active_comp = Some(id);
-        self.recall_selection(id);
-        self.state.current_track = None;
-        // A text-edit session belongs to the comp that owned it. Switching comps ends it; even
-        // a same-numbered layer in the new comp must not inherit the old IME composition.
-        self.state.text_edit = None;
-    }
-
-    /// Leave no comp active, keeping the one that was active in [`EditorState::comp_selections`].
-    pub fn activate_comp_none(&mut self) {
-        self.remember_selection();
-        self.state.active_comp = None;
-        self.clear_live_selection();
-        self.state.current_track = None;
-        self.state.text_edit = None;
-    }
-
-    fn remember_selection(&mut self) {
-        let Some(id) = self.state.active_comp else { return };
-        let sel = CompSelection {
-            layers: self.state.selected_layers.clone(),
-            props: self.state.selected_props.clone(),
-            keys: self.state.selected_keys.clone(),
-            vertices: self.state.selected_vertices.clone(),
-        };
-        if sel.is_empty() {
-            self.state.comp_selections.remove(&id);
-        } else {
-            self.state.comp_selections.insert(id, sel);
-        }
-    }
-
-    fn recall_selection(&mut self, id: ItemId) {
-        match self.state.comp_selections.remove(&id) {
-            Some(sel) => {
-                self.state.selected_layers = sel.layers;
-                self.state.selected_props = sel.props;
-                self.state.selected_keys = sel.keys;
-                self.state.selected_vertices = sel.vertices;
-            }
-            None => self.clear_live_selection(),
-        }
-    }
-
-    fn clear_live_selection(&mut self) {
-        self.state.selected_layers.clear();
-        self.state.selected_props.clear();
-        self.state.selected_keys.clear();
-        self.state.selected_vertices.clear();
-    }
-
-    /// Open a comp in the viewer/timeline and make it active.
-    pub fn open_comp(&mut self, id: ItemId) {
-        if self.project.comp(id).is_none() {
-            return;
-        }
-        if !self.state.open_comps.contains(&id) {
-            self.state.open_comps.push(id);
-        }
-        if self.state.active_comp != Some(id) {
-            let previous = self.state.active_comp;
-            self.state.recent_comps.retain(|c| *c != id && Some(*c) != previous);
-            if let Some(previous) = previous {
-                self.state.recent_comps.insert(0, previous);
-                self.state.recent_comps.truncate(32);
-            }
-        }
-        self.activate_comp(id);
-        self.events.push(Event::OpenComp(id));
-    }
-
-    /// The open compositions and their current times, as a project file records them
-    /// ([`effectcraft_project::SavedView`]).
-    pub fn saved_view(&self) -> effectcraft_project::SavedView {
-        let comp_times = self.state.times.iter().filter(|(id, _)| self.project.comp(**id).is_some()).map(|(id, t)| (*id, *t)).collect();
-        effectcraft_project::SavedView { active_comp: self.state.active_comp, open_comps: self.state.open_comps.clone(), comp_times }
-    }
-
-    /// Reopen the compositions a project file was saved with (#748), each at its saved current
-    /// time (#1714). Ids that no longer name a comp are skipped; with none left the project stays
-    /// on the comp [`Session::replace_project`] opened (its first), as files from before the view
-    /// was saved do.
-    pub fn restore_view(&mut self, view: &effectcraft_project::SavedView) {
-        for (id, t) in &view.comp_times {
-            if let Some(comp) = self.project.comp(*id) {
-                let t = comp_frame_at(comp, *t);
-                self.state.times.insert(*id, t);
-            }
-        }
-        let mut open: Vec<ItemId> = Vec::new();
-        for id in view.open_comps.iter().copied().filter(|id| self.project.comp(*id).is_some()) {
-            if !open.contains(&id) {
-                open.push(id);
-            }
-        }
-        let Some(active) = view.active_comp.filter(|id| self.project.comp(*id).is_some()).or_else(|| open.first().copied()) else { return };
-        self.state.open_comps = open;
-        self.open_comp(active);
-    }
-
-    pub fn toast(&mut self, msg: impl Into<String>) {
-        self.events.push(Event::Toast { message: msg.into(), error: false });
-    }
-
-    pub fn drain_events(&mut self) -> Vec<Event> {
-        std::mem::take(&mut self.events)
-    }
-
-    /// The 3D view camera of a comp's viewer (None = the active camera).
-    pub fn view_camera(&self, comp: ItemId) -> Option<effectcraft_render::three_d::CameraState> {
-        let c = self.project.comp(comp)?;
-        if !c.has_3d() {
-            return None;
-        }
-        self.state.views3d.get(&comp)?.override_camera(c.width as f64, c.height as f64)
-    }
-
-    /// Render a comp frame with the session's footage + expression hosts.
-    pub fn render(&self, comp: ItemId, t: Tick, opts: RenderOpts) -> Image {
-        self.renderer(opts).comp_frame(comp, t)
-    }
-
-    /// The renderer [`Session::render`] uses: the session's footage, expressions, layer cache and
-    /// accelerator, and the render prefs (nested switches, draft shadows) over `opts`.
-    pub fn renderer(&self, opts: RenderOpts) -> Renderer<'_> {
-        let opts = RenderOpts { nested_switches: self.prefs.general.switches_affect_nested_comps, draft_shadows: self.prefs.three_d.realtime_shadows, ..opts };
-        let mut r = Renderer::new(&self.project, self.footage.as_ref(), opts);
-        r.expr = self.expr.as_deref();
-        r.cache = Some(&self.layer_cache);
-        r.accel = self.accel.as_deref();
-        r
-    }
-
-    /// Resolve a comp reference (item id number or name; `None`/null = the active comp).
-    pub fn resolve_comp(&self, comp: Option<&Value>) -> Result<ItemId> {
-        let p = match comp {
-            Some(v) if !v.is_null() => serde_json::json!({ "comp": v }),
-            _ => serde_json::json!({}),
-        };
-        commands::comp_id(self, &p)
-    }
-
-    /// Render a comp frame (comp time `t`) as opaque 8-bit RGBA over the comp background, scaled
-    /// so the longest side is at most `max_side` pixels (0 = full size). Returns (width, height, rgba).
-    pub fn render_rgba8(&self, comp: ItemId, t: Tick, max_side: u32) -> Result<(u32, u32, Vec<u8>)> {
-        let c = self.project.comp(comp).ok_or(EngineError::NoComp)?;
-        let long = c.width.max(c.height).max(1) as f64;
-        let scale = if max_side == 0 { 1.0 } else { (max_side as f64 / long).min(1.0) };
-        let img = self.render(comp, t, RenderOpts { scale, backend: effectcraft_render::Backend::Auto, ..Default::default() });
-        Ok((img.width, img.height, img.to_rgba8_over(c.background)))
-    }
-
-    /// A Project panel thumbnail of an item (a comp at `t`, footage at its first frame), longest
-    /// side at most `max_side`, as a job that owns everything it reads: frontends run it off the
-    /// UI thread (a big comp takes far longer than a frame). `None` for items without pixels.
-    pub fn thumbnail_job(&self, item: ItemId, t: Tick, max_side: u32) -> Option<ThumbnailJob> {
-        let it = self.project.item(item)?;
-        let footage = self.footage.clone();
-        match &it.kind {
-            effectcraft_project::ItemKind::Comp(c) => {
-                let (project, expr, cache) = (self.project.clone(), self.expr.clone(), self.layer_cache.clone());
-                let long = c.width.max(c.height).max(1) as f64;
-                let scale = if max_side == 0 { 1.0 } else { (max_side as f64 / long).min(1.0) };
-                let opts = RenderOpts {
-                    scale,
-                    nested_switches: self.prefs.general.switches_affect_nested_comps,
-                    draft_shadows: self.prefs.three_d.realtime_shadows,
-                    ..Default::default()
-                };
-                let bg = c.background;
-                Some(Box::new(move || {
-                    let mut r = Renderer::new(&project, footage.as_ref(), opts);
-                    r.expr = expr.as_deref();
-                    r.cache = Some(&cache);
-                    let img = r.comp_frame(item, t);
-                    Some((img.width, img.height, img.to_rgba8_over(bg)))
-                }))
-            }
-            effectcraft_project::ItemKind::Footage(f) if f.has_video => {
-                let f = f.clone();
-                Some(Box::new(move || {
-                    let img = footage.frame(item, &f, Tick(0))?;
-                    // Point-sample down to at most `max_side` on the long side.
-                    let step = (img.width.max(img.height) as f32 / max_side.max(1) as f32).ceil().max(1.0) as u32;
-                    let (w, h) = (img.width.div_ceil(step), img.height.div_ceil(step));
-                    let full = img.to_rgba8();
-                    let mut px = Vec::with_capacity((w * h * 4) as usize);
-                    for y in 0..h {
-                        for x in 0..w {
-                            let i = (((y * step) * img.width + x * step) * 4) as usize;
-                            px.extend_from_slice(&full[i..i + 4]);
-                        }
-                    }
-                    Some((w, h, px))
-                }))
-            }
-            _ => None,
-        }
-    }
-
-    /// [`Session::render_rgba8`], or with `transparent` the frame's own straight alpha (what a
-    /// render with RGB + Alpha channels writes) instead of compositing over the background.
-    pub fn render_rgba8_alpha(&self, comp: ItemId, t: Tick, max_side: u32, transparent: bool) -> Result<(u32, u32, Vec<u8>)> {
-        if !transparent {
-            return self.render_rgba8(comp, t, max_side);
-        }
-        let c = self.project.comp(comp).ok_or(EngineError::NoComp)?;
-        let long = c.width.max(c.height).max(1) as f64;
-        let scale = if max_side == 0 { 1.0 } else { (max_side as f64 / long).min(1.0) };
-        let img = self.render(comp, t, RenderOpts { scale, backend: effectcraft_render::Backend::Auto, ..Default::default() });
-        Ok((img.width, img.height, img.to_rgba8()))
-    }
-
-    /// Make the media layer and the layer cache let go of what they decoded from `footage`'s
-    /// files (it keys frames by path, so an overwritten file would keep showing its old pixels).
-    pub(crate) fn forget_decoded(&self, footage: &effectcraft_project::Footage) {
-        for p in std::iter::once(&footage.path).chain(&footage.sequence) {
-            self.footage.forget(p);
-        }
-        self.layer_cache.clear();
-    }
-
-    /// Replace the whole project (open/new), resetting history and state.
-    pub fn replace_project(&mut self, mut p: Project, path: Option<String>) {
-        if self.stop_render()
-            && let Some(mut job) = self.render_job.take()
-        {
-            // Let the worker notice the cancel; its updates refer to the old project.
-            job.wait();
-        }
-        self.render_job = None;
-        self.stored_paths = Default::default();
-        self.stop_track();
-        self.track_job = None;
-        self.stop_mask_track();
-        self.mask_job = None;
-        self.stop_warp();
-        self.warp_job = None;
-        self.warp_pending.clear();
-        self.stop_camera();
-        self.camera_job = None;
-        self.camera_pending.clear();
-        self.stop_roto();
-        self.roto_job = None;
-        self.roto_pending.clear();
-        self.drop_tasks();
-        self.script_ui.project_epoch = self.script_ui.project_epoch.wrapping_add(1);
-        p.fix_next_id();
-        upgrade_effects(&mut p);
-        // The media layer keys decoded frames by path: files of the new project may have changed
-        // since an earlier project decoded them (#1070).
-        for it in p.items.values() {
-            if let effectcraft_project::ItemKind::Footage(f) = &it.kind {
-                self.forget_decoded(f);
-            }
-        }
-        self.layer_cache.clear();
-        self.project = Arc::new(p);
-        // Its files may have changed since they were last stamped.
-        self.disk_salt = None;
-        self.history = History::default();
-        self.state = EditorState { snapping: true, view_layout: 1, ..Default::default() };
-        self.path = path;
-        self.bump();
-        self.mark_saved();
-        let first = self.project.comps().next().map(|(id, _)| *id);
-        if let Some(c) = first {
-            self.open_comp(c);
-        }
-    }
-}
-
-/// Bring effect instances saved by earlier versions up to date with the effect registry
-/// (renamed / regrouped / added parameters, reordered popups; see
-/// [`effectcraft_effects::migrate`]), and a project from before
-/// [`effectcraft_project::SCHEMA_EFFECT_SPACE`] into effect space
-/// ([`effectcraft_effects::migrate::to_effect_space`]). Stamps the current schema.
-pub fn upgrade_effects(p: &mut Project) {
-    let to_effect_space = p.schema < effectcraft_project::SCHEMA_EFFECT_SPACE;
-    // Effect bounds per layer: (size, top-left in layer coordinates).
-    let mut bounds = std::collections::HashMap::new();
-    for (cid, c) in p.comps() {
-        for l in &c.layers {
-            bounds.insert((*cid, l.id), effectcraft_render::effect_bounds(p, c, l));
-        }
-    }
-    let mut next = p.next_id;
-    for (cid, it) in p.items.iter_mut() {
-        let effectcraft_project::ItemKind::Comp(c) = &mut it.kind else { continue };
-        for l in &mut std::sync::Arc::make_mut(c).layers {
-            let (size, origin) = bounds.get(&(*cid, l.id)).copied().unwrap_or(([100.0, 100.0], [0.0; 2]));
-            // Effect space starts at the bounds' top-left: positions move by minus that corner.
-            // Adjustment layers run their effects on the comp below as it is: nothing moves.
-            let shift = |o: [f64; 2]| [-o[0], -o[1]];
-            let d = if l.switches.adjustment { [0.0; 2] } else { shift(origin) };
-            let clone_d = |src: Option<u64>| match src {
-                Some(id) => bounds.get(&(*cid, effectcraft_project::LayerId(id))).map_or([0.0; 2], |b| shift(b.1)),
-                None => d,
-            };
-            let Some(fx) = l.props.sub_mut("effects") else { continue };
-            for n in &mut fx.children {
-                let effectcraft_project::Node::Group(g) = n else { continue };
-                let effectcraft_project::GroupKind::Effect { effect } = &g.kind else { continue };
-                if let Some(spec) = effectcraft_effects::find(effect) {
-                    effectcraft_effects::migrate::upgrade_instance(spec, g, &mut effectcraft_project::build::Ids(&mut next), size);
-                    if to_effect_space {
-                        effectcraft_effects::migrate::to_effect_space(spec, g, size, d, &clone_d);
-                    }
-                }
-            }
-        }
-    }
-    p.next_id = next;
-    p.schema = effectcraft_project::SCHEMA_VERSION;
-}
-
 #[cfg(test)]
 mod rq_tests;
 #[cfg(test)]
 mod tests;
-#[cfg(test)]
-mod tests_3d;
-#[cfg(test)]
-mod tests_anim_presets;
-#[cfg(test)]
-mod tests_anim_tools;
-#[cfg(test)]
-mod tests_camera_track;
-#[cfg(test)]
-mod tests_codec_options;
-#[cfg(test)]
-mod tests_color_view;
-#[cfg(test)]
-mod tests_crypto_pick;
-#[cfg(test)]
-mod tests_delete_keys;
-#[cfg(test)]
-mod tests_disk_cache;
-#[cfg(test)]
-mod tests_effects;
-#[cfg(test)]
-mod tests_essential;
-#[cfg(test)]
-mod tests_essential_more;
-#[cfg(test)]
-mod tests_face;
-#[cfg(test)]
-mod tests_fidelity;
-#[cfg(test)]
-mod tests_frame_export;
-#[cfg(test)]
-mod tests_fuzz_open;
-#[cfg(test)]
-mod tests_import_project;
-#[cfg(test)]
-mod tests_key_metadata_order;
-#[cfg(test)]
-mod tests_keylight;
-#[cfg(test)]
-mod tests_limits;
-#[cfg(test)]
-mod tests_lottie;
-#[cfg(test)]
-mod tests_m137;
-#[cfg(test)]
-mod tests_m145;
-#[cfg(test)]
-mod tests_markers;
-#[cfg(test)]
-mod tests_mask_warp;
-#[cfg(test)]
-mod tests_menu_cmds;
-#[cfg(test)]
-mod tests_model3d;
-#[cfg(test)]
-mod tests_motion_blur_depth;
-#[cfg(test)]
-mod tests_project_items;
-#[cfg(test)]
-mod tests_proxy;
-#[cfg(test)]
-mod tests_quick_offset;
-#[cfg(test)]
-mod tests_replace_source;
-#[cfg(test)]
-mod tests_rig3d;
-#[cfg(test)]
-mod tests_sequence;
-#[cfg(test)]
-mod tests_settings;
-#[cfg(test)]
-mod tests_shortcut_cmds;
-#[cfg(test)]
-mod tests_stubs;
-#[cfg(test)]
-mod tests_styles;
-#[cfg(test)]
-mod tests_tail;
-#[cfg(test)]
-mod tests_text;
-#[cfg(test)]
-mod tests_text_edit;
-#[cfg(test)]
-mod tests_timeline;
-#[cfg(test)]
-mod tests_timeline_interchange;
-#[cfg(test)]
-mod tests_track;
-#[cfg(test)]
-mod tests_vector_import;
-#[cfg(test)]
-mod tests_viewer;
-
-/// Font families available to text layers (bundled + scanned system fonts).
-/// Text animation presets: (id, name), for menus.
-pub fn text_presets() -> Vec<(String, String)> {
-    commands::text_preset_list()
-}
-
-/// Built-in animation presets (Effects & Presets ▸ * Animation Presets): (id, name, category).
-pub fn animation_presets() -> Vec<(String, String, String)> {
-    commands::builtin_preset_list()
-}
-
-pub fn text_families() -> Vec<String> {
-    effectcraft_text::families().into_iter().map(|(f, _)| f).collect()
-}
-
-/// The styles a family offers (its own faces, in weight order), for the style menus. A family
-/// that isn't installed offers the usual styles, which resolve to Inter's.
-pub fn font_styles(family: &str) -> Vec<String> {
-    effectcraft_text::families()
-        .into_iter()
-        .find(|(f, _)| f.eq_ignore_ascii_case(family))
-        .map(|(_, st)| st)
-        .filter(|st| !st.is_empty())
-        .unwrap_or_else(|| ["Regular", "Medium", "SemiBold", "Bold", "Italic"].iter().map(|s| s.to_string()).collect())
-}
-
-/// The OpenType feature tags (GSUB / GPOS) of the face a family + style resolves to.
-pub fn font_features(family: &str, style: &str) -> Vec<String> {
-    effectcraft_text::fonts::face(effectcraft_text::resolve(family, style).face).features()
-}
-
-/// One row of the Character panel's font menu.
-#[derive(Clone, Debug, PartialEq)]
-pub struct FontRow {
-    /// The family to apply (empty for the separator after the recent fonts).
-    pub family: String,
-    /// What the menu shows: the English family name, or the font's own-language name when
-    /// Settings ▸ Type ▸ Show Font Names in English is off.
-    pub display: String,
-    pub recent: bool,
-    /// A variable font (the menu's Variable Fonts filter keeps only these).
-    pub variable: bool,
-}
-
-/// Outline polylines of "Sample" set in `family` at `size` px (baseline at y = 0, y down), for
-/// the font menu's preview (Settings ▸ Type ▸ Show Font Preview).
-pub fn font_preview(family: &str, size: f64) -> Vec<Vec<[f32; 2]>> {
-    use kurbo::PathEl;
-    let st = effectcraft_keyframe::text_doc::CharStyle { font: family.to_string(), size, ..Default::default() };
-    let mut out = vec![];
-    let mut x = 0.0;
-    for ch in "Sample".chars() {
-        let (path, adv) = effectcraft_text::char_glyph_style(&st, ch);
-        let mut cur: Vec<[f32; 2]> = vec![];
-        let pt = |p: kurbo::Point| [(p.x + x) as f32, p.y as f32];
-        kurbo::flatten(&path, 0.2, |el| match el {
-            PathEl::MoveTo(p) => {
-                if cur.len() > 1 {
-                    out.push(std::mem::take(&mut cur));
-                }
-                cur = vec![pt(p)];
-            }
-            PathEl::LineTo(p) => cur.push(pt(p)),
-            PathEl::ClosePath => {
-                if let Some(f) = cur.first().copied() {
-                    cur.push(f);
-                }
-                if cur.len() > 1 {
-                    out.push(std::mem::take(&mut cur));
-                }
-            }
-            _ => {}
-        });
-        if cur.len() > 1 {
-            out.push(cur);
-        }
-        x += adv;
-    }
-    out
-}
-
-/// The Character panel's font menu: the recent fonts (Settings ▸ Type ▸ Number of Recent Fonts
-/// to Display), a separator, then every family. Each row says whether the family is variable,
-/// for the menu's Variable Fonts filter.
-pub fn font_menu(prefs: &prefs::Prefs) -> Vec<FontRow> {
-    let all = text_families();
-    let native = if prefs.type_.font_names_in_english { Default::default() } else { effectcraft_text::fonts::native_families() };
-    let variable = effectcraft_text::fonts::variable_families();
-    let row = |f: &String, recent: bool| FontRow {
-        family: f.clone(),
-        display: native.get(f).cloned().unwrap_or_else(|| f.clone()),
-        recent,
-        variable: variable.contains(f),
-    };
-    let mut out: Vec<FontRow> = prefs.recent_fonts_shown().iter().filter(|f| all.contains(f)).map(|f| row(f, true)).collect();
-    if !out.is_empty() {
-        out.push(FontRow { family: String::new(), display: "-".into(), recent: false, variable: false });
-    }
-    out.extend(all.iter().map(|f| row(f, false)));
-    out
-}
-#[cfg(test)]
-mod tests_history;
-#[cfg(test)]
-mod tests_models;
-#[cfg(test)]
-mod tests_paint;
-#[cfg(test)]
-mod tests_panels;
-#[cfg(test)]
-mod tests_roto;
-
-#[cfg(test)]
-mod tests_key_time;
diff --git a/crates/engine/src/menus.rs b/crates/engine/src/menus.rs
index aa2e4ffe1..df07c633b 100644
--- a/crates/engine/src/menus.rs
+++ b/crates/engine/src/menus.rs
@@ -61,6 +61,12 @@ fn file_name(p: &str) -> String {
     std::path::Path::new(p).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| p.to_string())
 }
 
+/// The labels of a recent-files list: `names[i]`, or the whole of `full[i]` when another entry
+/// has the same name, so entries for two files named `Tool.jsx` tell them apart.
+fn distinct_labels(names: Vec<String>, full: &[String]) -> Vec<String> {
+    names.iter().zip(full).map(|(n, f)| if names.iter().filter(|m| *m == n).count() > 1 { f.clone() } else { n.clone() }).collect()
+}
+
 fn dyn_entry(label: String, command: &str, params: Value) -> MenuEntry {
     MenuEntry { label, command: command.into(), params, shortcut: None, alt_shortcuts: vec![] }
 }
@@ -72,26 +78,34 @@ fn holder_of(s: &Session, keys: &str) -> Option<String> {
 }
 
 /// The entries of a `@dynamic:<name>` node, and the disabled placeholder shown when there are
-/// none: `recentProjects`, `recentFootage`, `recentPresets`, `history` (undo steps, newest
+/// none: `recentProjects`, `recentFootage`, `recentPresets`, `recentScripts` (File ▸ Scripts ▸
+/// Recent Script Files), `history` (undo steps, newest
 /// first), `view3dShortcuts`, `workspaceShortcuts`, `savedWorkspaces` (Window ▸ Workspace) and
 /// `openViewers` (open compositions other than the active one), `scripts` (File ▸ Scripts) and
 /// `scriptPanels` (ScriptUI panels).
 pub fn dynamic(s: &Session, name: &str, cx: &DynCtx) -> (Vec<MenuEntry>, Option<&'static str>) {
     use serde_json::json;
     let indexed = |list: &[String], cmd: &str, stem: bool| -> Vec<MenuEntry> {
-        list.iter()
-            .enumerate()
-            .map(|(i, p)| {
-                let n =
-                    if stem { std::path::Path::new(p).file_stem().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| p.clone()) } else { file_name(p) };
-                dyn_entry(n, cmd, json!({"index": i}))
-            })
-            .collect()
+        let names = list
+            .iter()
+            .map(
+                |p| if stem { std::path::Path::new(p).file_stem().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| p.clone()) } else { file_name(p) },
+            )
+            .collect();
+        distinct_labels(names, list).into_iter().enumerate().map(|(i, n)| dyn_entry(n, cmd, json!({"index": i}))).collect()
     };
     match name {
         "recentProjects" => (indexed(&s.prefs.recent_projects, "file.openRecent", false), Some("No Recent Projects")),
         "recentFootage" => (indexed(&s.prefs.recent_footage, "file.importRecent", false), Some("No Recent Footage")),
         "recentPresets" => (indexed(&s.prefs.recent_presets, "anim.applyRecentPreset", true), Some("No Recent Presets")),
+        "recentScripts" => {
+            let full: Vec<String> = s.prefs.recent_scripts.iter().map(|r| r.text().to_string()).collect();
+            let names = full.iter().map(|p| file_name(p)).collect();
+            (
+                distinct_labels(names, &full).into_iter().enumerate().map(|(i, n)| dyn_entry(n, "file.runScript", json!({"recent": i}))).collect(),
+                Some("No Recent Script Files"),
+            )
+        }
         "history" => (
             s.history.undo.iter().rev().enumerate().map(|(i, (l, _))| dyn_entry(format!("Undo {l}"), "edit.history", json!({"steps": i + 1}))).collect(),
             Some("No History"),
@@ -576,6 +590,8 @@ File
     Install Script File... | file.installScript
     Install ScriptUI Panel... | file.installScriptUIPanel
     Run Script File... | file.runScript
+    Recent Script Files
+      @dynamic:recentScripts
   ---
   Create Proxy
     Still... | file.createProxy {"kind":"still"}
diff --git a/crates/engine/src/prefs.rs b/crates/engine/src/prefs.rs
deleted file mode 100644
index 30b806683..000000000
--- a/crates/engine/src/prefs.rs
+++ /dev/null
@@ -1,1518 +0,0 @@
-//! Settings (After Effects' Preferences): a versioned serde model, addressed by dotted keys
-//! (`general.undoLevels`, `autoSave.intervalMinutes`, `labels.3.name`), plus the page schema the
-//! Settings dialog and agents (`prefs.pages`) are built from.
-//!
-//! Settings are stored as JSON (`prefs.json`) through the session's [`crate::config::ConfigStore`].
-//! Loading is forgiving: missing keys take their defaults, unknown keys (written by a newer
-//! version) are kept and written back, and older layouts are migrated ([`migrate`]).
-//!
-//! Every setting in [`pages`] says whether it already changes behaviour (`live`). Settings that
-//! don't yet are still shown (After Effects parity of the dialog) and are listed in
-//! `docs/preferences.md`; a test keeps that list in step with the schema.
-
-use std::collections::BTreeMap;
-
-use effectcraft_color::Label;
-use effectcraft_time::Tick;
-use serde::{Deserialize, Serialize};
-use serde_json::{Map, Value, json};
-
-/// Current settings layout version.
-pub const PREFS_VERSION: u32 = 2;
-/// Settings file name in the config store.
-pub const PREFS_FILE: &str = "prefs.json";
-
-/// Settings ▸ General ▸ Language: (label, `general.language` value).
-pub const LANGUAGES: &[(&str, &str)] = &[
-    ("Match System", "system"),
-    ("English", "en"),
-    // Alphabetical by the language's own name after English; Cyrillic, Georgian, then CJK names
-    // follow the Latin ones.
-    ("Čeština", "cs"),
-    ("Deutsch", "de"),
-    ("Español", "es"),
-    ("Français", "fr"),
-    ("Português (Brasil)", "pt-br"),
-    ("Русский", "ru"),
-    ("Українська", "uk"),
-    ("ქართული", "ka"),
-    ("日本語", "ja"),
-    ("简体中文", "zh-hans"),
-    ("繁體中文", "zh-hant"),
-];
-
-/// Settings ▸ Startup & Repair ▸ Window Graphics: (label, `startup.windowGraphics` value).
-pub const WINDOW_GRAPHICS: &[(&str, &str)] = &[("Automatic", "auto"), ("OpenGL (compatibility)", "gl")];
-
-/// Settings ▸ Appearance ▸ Appearance Mode: (label, `appearance.appearanceMode` value). Auto
-/// follows the operating system's light or dark appearance.
-pub const APPEARANCE_MODES: &[(&str, &str)] = &[("Sync with System", "auto"), ("Dark", "dark"), ("Light", "light")];
-
-/// The dark family of themes: (label, `appearance.darkTheme` value).
-pub const DARK_THEMES: &[(&str, &str)] = &[("Dark", "dark"), ("Darker", "darker")];
-
-/// The light family of themes: (label, `appearance.lightTheme` value).
-pub const LIGHT_THEMES: &[(&str, &str)] = &[("Light", "light")];
-
-/// Every theme (the legacy single-theme `appearance.theme`).
-pub const THEMES: &[(&str, &str)] = &[("Dark", "dark"), ("Darker", "darker"), ("Light", "light")];
-
-/// The settings whose value must be one of their choices.
-fn choices(key: &str) -> Option<&'static [(&'static str, &'static str)]> {
-    match key {
-        "general.language" => Some(LANGUAGES),
-        "startup.windowGraphics" => Some(WINDOW_GRAPHICS),
-        "appearance.appearanceMode" => Some(APPEARANCE_MODES),
-        "appearance.darkTheme" => Some(DARK_THEMES),
-        "appearance.lightTheme" => Some(LIGHT_THEMES),
-        "appearance.theme" => Some(THEMES),
-        _ => None,
-    }
-}
-
-fn is_choice(choices: &[(&str, &str)], v: &str) -> bool {
-    choices.iter().any(|(_, c)| *c == v)
-}
-
-/// Unknown keys inside a page, kept so a newer version's settings survive a round trip.
-type Extra = BTreeMap<String, Value>;
-
-macro_rules! page {
-    ($(#[$m:meta])* $name:ident { $($(#[$fm:meta])* $f:ident : $t:ty = $d:expr),* $(,)? }) => {
-        $(#[$m])*
-        #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-        #[serde(default, rename_all = "camelCase")]
-        pub struct $name {
-            $($(#[$fm])* pub $f: $t,)*
-            #[serde(flatten)]
-            pub extra: Extra,
-        }
-        impl Default for $name {
-            fn default() -> Self {
-                $name { $($f: $d,)* extra: Extra::new() }
-            }
-        }
-    };
-}
-
-page!(General {
-    /// Interface language: `system` (the operating system's, where EffectCraft has it, else
-    /// English), or a language code from `LANGUAGES`.
-    language: String = "system".into(),
-    /// Levels of Undo (1–99).
-    undo_levels: u32 = 32,
-    /// Path Point and Handle Size (px).
-    path_point_size: u32 = 5,
-    show_tool_tips: bool = true,
-    /// Create New Layers at Composition Start Time (off: at the current time).
-    create_layers_at_comp_start: bool = true,
-    switches_affect_nested_comps: bool = true,
-    /// Default Spatial Interpolation to Linear.
-    default_spatial_linear: bool = false,
-    preserve_constant_vertex_count: bool = true,
-    /// Synchronize Time of All Related Items.
-    sync_time_related_items: bool = true,
-    expression_pick_whip_compact: bool = true,
-    /// Create Split Layers Above Original Layer (After Effects' default).
-    create_split_layers_above: bool = true,
-    use_system_color_picker: bool = false,
-    /// Number of projects in File ▸ Open Recent.
-    recent_items: u32 = 10,
-});
-
-page!(Startup {
-    show_home_on_launch: bool = true,
-    show_home_on_open_project: bool = false,
-    /// After a crash, offer to open the most recent auto-save.
-    offer_crash_recovery: bool = true,
-    /// What the desktop window draws with, from the next launch: `auto` (the platform's best
-    /// graphics API) or `gl` (OpenGL, for drivers that crash with the others). A launch that
-    /// stops as its window opens switches it to `gl` (#243).
-    window_graphics: String = "auto".into(),
-});
-
-page!(ProjectPrefs {
-    /// Open a template project for File ▸ New ▸ New Project.
-    use_template: bool = false,
-    template_path: String = String::new(),
-});
-
-page!(AutoSave {
-    enabled: bool = true,
-    interval_minutes: u32 = 20,
-    max_versions: u32 = 5,
-    /// `nextToProject` (an "EffectCraft Auto-Save" folder beside the project) or `custom`.
-    location: String = "nextToProject".into(),
-    folder: String = String::new(),
-    save_on_render_start: bool = false,
-});
-
-page!(CompositionPrefs {
-    /// Motion path: `all`, `none`, `seconds`, `keyframes`.
-    motion_path: String = "keyframes".into(),
-    motion_path_seconds: f64 = 15.0,
-    motion_path_keyframes: u32 = 15,
-    show_rendering_progress: bool = true,
-    hardware_accelerate_panels: bool = true,
-});
-
-page!(Previews {
-    /// Largest downsampling while playing back: `1/2`, `1/4`, `1/8`.
-    adaptive_resolution_limit: String = "1/8".into(),
-    show_internal_wireframes: bool = false,
-    cache_frames_when_idle: bool = false,
-    fast_previews: bool = false,
-    /// `faster` or `moreAccurate`.
-    zoom_quality: String = "moreAccurate".into(),
-    show_gpu_info: bool = false,
-    /// The monitor's colour space for View ▸ Use Display Color Management: `srgb` or `p3`.
-    display_profile: String = "srgb".into(),
-});
-
-page!(Appearance {
-    /// The single theme before appearance modes (`dark`, `darker` or `light`), kept for older
-    /// settings files and automation: setting it picks its family's mode and theme. While the mode
-    /// is Dark or Light it mirrors the theme in use.
-    theme: String = "dark".into(),
-    /// `auto` (follow the operating system), `dark` or `light`. New installs stay Dark.
-    appearance_mode: String = "dark".into(),
-    /// The theme used in dark appearance: `dark` or `darker`.
-    dark_theme: String = "dark".into(),
-    /// The theme used in light appearance: `light`.
-    light_theme: String = "light".into(),
-    /// Theme shortcuts in the appearance context menu.
-    favorite_themes: Vec<String> = Vec::new(),
-    /// User interface brightness, -1 (darker) … 1 (lighter).
-    brightness: f64 = 0.0,
-    /// The size of the whole interface in percent (75–200), on top of the display's own scale.
-    ui_scale: u32 = 100,
-    use_label_color_for_handles: bool = true,
-    use_label_color_for_tabs: bool = true,
-    cycle_mask_colors: bool = true,
-    use_gradients: bool = true,
-    /// macOS: draw the menu bar inside the window instead of the system menu bar.
-    in_window_menu_bar_mac: bool = false,
-});
-
-page!(Grids {
-    grid_color: String = "#7a9cff".into(),
-    grid_spacing: f64 = 100.0,
-    grid_subdivisions: u32 = 4,
-    /// `lines`, `dashed` or `dots`.
-    grid_style: String = "lines".into(),
-    proportional_horizontal: u32 = 4,
-    proportional_vertical: u32 = 4,
-    guide_color: String = "#3cc8f0".into(),
-    guide_style: String = "lines".into(),
-    action_safe: f64 = 10.0,
-    title_safe: f64 = 20.0,
-});
-
-page!(TypePrefs {
-    /// `latin` or `southAsian` (South Asian and Middle Eastern).
-    text_engine: String = "latin".into(),
-    font_preview: bool = true,
-    recent_fonts: u32 = 10,
-    font_names_in_english: bool = false,
-});
-
-page!(Import {
-    /// Still footage duration: `compLength` or `seconds`.
-    still_footage: String = "compLength".into(),
-    still_seconds: f64 = 5.0,
-    sequence_fps: f64 = 30.0,
-    report_missing_frames: bool = true,
-    /// Automatically Reload Footage whose file another app changed (size or modification time),
-    /// checked every two seconds and when the window comes back to the front: `off`,
-    /// `nonSequence` (the default, as in After Effects: image sequences are left alone) or `all`.
-    auto_reload_footage: String = "nonSequence".into(),
-    /// Interpret unlabeled alpha as: `ask`, `guess`, `ignore`, `straight`, `premultiplied`.
-    unlabeled_alpha: String = "ask".into(),
-    /// Default drag import as: `footage`, `comp`, `compLayerSizes`.
-    drag_import_as: String = "footage".into(),
-});
-
-page!(Export {
-    default_output_folder: String = String::new(),
-    segment_sequences: bool = false,
-    segment_sequence_files: u32 = 700,
-    segment_movies: bool = false,
-    segment_movie_mb: u32 = 1024,
-    append_bits_to_name: bool = false,
-});
-
-page!(Audio {
-    /// Output device name (empty = the system default).
-    output_device: String = String::new(),
-    /// Output mapping: device channel for the left / right output (1-based).
-    output_left: u32 = 1,
-    output_right: u32 = 2,
-    preview_sample_rate: u32 = 48_000,
-});
-
-page!(Disk {
-    disk_cache_enabled: bool = true,
-    disk_cache_max_gb: u32 = 100,
-    disk_cache_folder: String = String::new(),
-    media_cache_folder: String = String::new(),
-    conformed_media_folder: String = String::new(),
-});
-
-page!(Memory {
-    ram_reserved_gb: u32 = 6,
-    /// Processed-layer cache budget (MB).
-    layer_cache_mb: u32 = 1024,
-    /// Decoded footage frame cache budget (MB).
-    media_cache_mb: u32 = 1024,
-    /// RAM preview (viewer frame) cache budget (MB).
-    preview_cache_mb: u32 = 3072,
-    reduce_cache_when_low: bool = true,
-});
-
-page!(Video {
-    enable_output: bool = false,
-    device: String = String::new(),
-    output_during_playback: bool = true,
-    mirror_on_monitor: bool = true,
-    disable_when_background: bool = false,
-});
-
-page!(ThreeD {
-    /// Default 3D renderer for new compositions: `classic` or `advanced`.
-    default_renderer: String = "classic".into(),
-    show_reference_axes: bool = true,
-    extended_viewer: bool = false,
-    realtime_shadows: bool = true,
-});
-
-page!(
-    /// Settings ▸ Roto Brush.
-    RotoPrefs {
-        /// The segmentation model Roto Brush 2.0 / 3.0 use: `classical` (built in) or a model id
-        /// from `effectcraft_segment::MODELS` (once installed).
-        model: String = "classical".into(),
-    }
-);
-
-page!(
-    /// Settings ▸ Face Tracking.
-    FacePrefs {
-        /// The model Track Mask ▸ Face Tracking uses: `classical` (built in) or a model id from
-        /// `effectcraft_segment::MODELS` (once installed).
-        model: String = "classical".into(),
-    }
-);
-
-page!(Scripting {
-    allow_scripts_write_files: bool = false,
-    warn_executing_files: bool = true,
-    enable_js_debugger: bool = false,
-    editor_font_size: u32 = 13,
-    syntax_highlighting: bool = true,
-    line_numbers: bool = true,
-    auto_complete: bool = true,
-    bracket_matching: bool = true,
-    word_wrap: bool = false,
-    error_banner: bool = true,
-});
-
-impl Scripting {
-    /// Whether `other` grants scripts the same as this: Application Scripting (file and network
-    /// access, the warning before executing files, the debugger). Scripts can't change these
-    /// ([`crate::Session::execute_for_script`]): a script could otherwise give itself the
-    /// access the user withheld.
-    pub fn same_permissions(&self, other: &Scripting) -> bool {
-        self.allow_scripts_write_files == other.allow_scripts_write_files
-            && self.warn_executing_files == other.warn_executing_files
-            && self.enable_js_debugger == other.enable_js_debugger
-    }
-
-    /// Take `from`'s Application Scripting settings (see [`Scripting::same_permissions`]).
-    pub fn keep_permissions(&mut self, from: &Scripting) {
-        self.allow_scripts_write_files = from.allow_scripts_write_files;
-        self.warn_executing_files = from.warn_executing_files;
-        self.enable_js_debugger = from.enable_js_debugger;
-    }
-}
-
-/// One editable label: name and `#rrggbb` colour.
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct LabelPref {
-    pub name: String,
-    pub color: String,
-}
-
-/// A Composition Settings preset the user saved (Composition Settings ▸ Preset ▸ Save): the
-/// frame size, pixel aspect and frame rate, as in After Effects' own presets.
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-#[serde(rename_all = "camelCase")]
-pub struct CompPreset {
-    pub name: String,
-    pub width: u32,
-    pub height: u32,
-    pub pixel_aspect: f64,
-    pub frame_rate: f64,
-}
-
-impl CompPreset {
-    /// Longest preset name kept.
-    pub const MAX_NAME: usize = 128;
-
-    /// Values a composition accepts (a hand-edited settings file can hold anything).
-    pub fn is_valid(&self) -> bool {
-        let size = 4..=30000;
-        !self.name.trim().is_empty()
-            && self.name.chars().count() <= Self::MAX_NAME
-            && size.contains(&self.width)
-            && size.contains(&self.height)
-            && self.pixel_aspect.is_finite()
-            && (0.01..=100.0).contains(&self.pixel_aspect)
-            && self.frame_rate.is_finite()
-            && (1.0..=999.0).contains(&self.frame_rate)
-    }
-}
-
-/// Saved composition presets, skipping entries that don't parse instead of losing the list.
-fn lenient_comp_presets<'de, D: serde::Deserializer<'de>>(d: D) -> Result<Vec<CompPreset>, D::Error> {
-    let v = Vec::<Value>::deserialize(d)?;
-    Ok(v.into_iter().filter_map(|x| serde_json::from_value(x).ok()).collect())
-}
-
-fn default_labels() -> Vec<LabelPref> {
-    Label::ALL.iter().skip(1).map(|l| LabelPref { name: l.name().to_string(), color: hex(l.rgb()) }).collect()
-}
-
-fn hex([r, g, b]: [u8; 3]) -> String {
-    format!("#{r:02x}{g:02x}{b:02x}")
-}
-
-fn parse_hex(s: &str) -> Option<[u8; 3]> {
-    let h = s.trim().trim_start_matches('#');
-    if h.len() != 6 {
-        return None;
-    }
-    let p = |i: usize| u8::from_str_radix(h.get(i..i + 2)?, 16).ok();
-    Some([p(0)?, p(2)?, p(4)?])
-}
-
-/// All settings.
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-#[serde(default, rename_all = "camelCase")]
-pub struct Prefs {
-    pub version: u32,
-    pub general: General,
-    pub startup: Startup,
-    pub project: ProjectPrefs,
-    pub auto_save: AutoSave,
-    pub composition: CompositionPrefs,
-    pub previews: Previews,
-    pub appearance: Appearance,
-    pub grids: Grids,
-    /// The 16 labels (Red … Dark Green), in order.
-    pub labels: Vec<LabelPref>,
-    #[serde(rename = "type")]
-    pub type_: TypePrefs,
-    pub import: Import,
-    pub export: Export,
-    pub audio: Audio,
-    pub disk: Disk,
-    pub memory: Memory,
-    pub video: Video,
-    #[serde(rename = "threeD")]
-    pub three_d: ThreeD,
-    pub scripting: Scripting,
-    pub roto: RotoPrefs,
-    pub face: FacePrefs,
-    /// File ▸ Open Recent, newest first.
-    pub recent_projects: Vec<String>,
-    /// File ▸ Import Recent Footage, newest first.
-    pub recent_footage: Vec<String>,
-    /// Animation ▸ Recent Animation Presets (`.ecpreset` paths or built-in preset ids), newest
-    /// first.
-    pub recent_presets: Vec<String>,
-    /// Character panel: recently used font families, newest first.
-    pub recent_fonts: Vec<String>,
-    /// Effects & Presets: the starred effects' ids, in the order starred.
-    pub effects_favorites: Vec<String>,
-    /// Preview panel: every shortcut's options.
-    pub preview: crate::preview::PreviewSettings,
-    /// View ▸ Simulate Output ▸ My Custom RGB.
-    pub custom_rgb: crate::viewer::CustomRgb,
-    /// Composition Settings presets the user saved, in the order saved.
-    #[serde(deserialize_with = "lenient_comp_presets")]
-    pub comp_presets: Vec<CompPreset>,
-    /// Top-level keys this version doesn't know (kept for newer versions).
-    #[serde(flatten)]
-    pub extra: Extra,
-}
-
-impl Default for Prefs {
-    fn default() -> Self {
-        Prefs {
-            version: PREFS_VERSION,
-            general: General::default(),
-            startup: Startup::default(),
-            project: ProjectPrefs::default(),
-            auto_save: AutoSave::default(),
-            composition: CompositionPrefs::default(),
-            previews: Previews::default(),
-            appearance: Appearance::default(),
-            grids: Grids::default(),
-            labels: default_labels(),
-            type_: TypePrefs::default(),
-            import: Import::default(),
-            export: Export::default(),
-            audio: Audio::default(),
-            disk: Disk::default(),
-            memory: Memory::default(),
-            video: Video::default(),
-            three_d: ThreeD::default(),
-            scripting: Scripting::default(),
-            roto: RotoPrefs::default(),
-            face: FacePrefs::default(),
-            recent_projects: vec![],
-            recent_footage: vec![],
-            recent_presets: vec![],
-            recent_fonts: vec![],
-            effects_favorites: vec![],
-            preview: crate::preview::PreviewSettings::default(),
-            custom_rgb: crate::viewer::CustomRgb::default(),
-            comp_presets: vec![],
-            extra: Extra::new(),
-        }
-    }
-}
-
-/// Bring an older settings document up to [`PREFS_VERSION`].
-///
-/// - version 0/1 (early builds) kept a flat object: `undoLevels`, `autoSaveEnabled`,
-///   `autoSaveMinutes`, `autoSaveVersions`, `labelNames` (array) and `theme` at the top level.
-pub fn migrate(mut v: Value) -> Value {
-    let Some(obj) = v.as_object_mut() else { return json!({}) };
-    let version = obj.get("version").and_then(Value::as_u64).unwrap_or(0);
-    if version < 2 {
-        let moved = |from: &str, page: &str, key: &str, obj: &mut Map<String, Value>| {
-            if let Some(x) = obj.remove(from) {
-                let p = obj.entry(page.to_string()).or_insert_with(|| json!({}));
-                if let Some(p) = p.as_object_mut() {
-                    p.entry(key.to_string()).or_insert(x);
-                }
-            }
-        };
-        moved("undoLevels", "general", "undoLevels", obj);
-        moved("autoSaveEnabled", "autoSave", "enabled", obj);
-        moved("autoSaveMinutes", "autoSave", "intervalMinutes", obj);
-        moved("autoSaveVersions", "autoSave", "maxVersions", obj);
-        moved("theme", "appearance", "theme", obj);
-        if let Some(Value::Array(names)) = obj.remove("labelNames") {
-            let mut labels = default_labels();
-            for (l, n) in labels.iter_mut().zip(names) {
-                if let Some(n) = n.as_str() {
-                    l.name = n.to_string();
-                }
-            }
-            obj.insert("labels".into(), serde_json::to_value(labels).unwrap_or_default());
-        }
-    }
-    // Settings saved before appearance modes had one theme: keep showing it, as a fixed Dark or
-    // Light mode, instead of switching established users to Auto.
-    if let Some(a) = obj.get_mut("appearance").and_then(Value::as_object_mut)
-        && !a.contains_key("appearanceMode")
-        && let Some(theme) = a.get("theme").and_then(Value::as_str).map(str::to_string)
-        && let Some((mode, slot)) = theme_family(&theme)
-    {
-        a.insert("appearanceMode".into(), json!(mode));
-        a.insert(slot.into(), json!(theme));
-    }
-    obj.insert("version".into(), json!(PREFS_VERSION));
-    v
-}
-
-/// The appearance mode and the per-mode setting a theme belongs to (`darker` → (`dark`,
-/// `darkTheme`)); `None` for an unknown theme.
-pub fn theme_family(theme: &str) -> Option<(&'static str, &'static str)> {
-    if is_choice(DARK_THEMES, theme) {
-        Some(("dark", "darkTheme"))
-    } else if is_choice(LIGHT_THEMES, theme) {
-        Some(("light", "lightTheme"))
-    } else {
-        None
-    }
-}
-
-impl Appearance {
-    /// Show the legacy single `theme`: fix the mode to its family and remember it as that
-    /// family's theme. An unknown theme changes nothing.
-    pub fn select_theme(&mut self) {
-        match theme_family(&self.theme) {
-            Some((mode, "darkTheme")) => {
-                self.appearance_mode = mode.into();
-                self.dark_theme = self.theme.clone();
-            }
-            Some((mode, _)) => {
-                self.appearance_mode = mode.into();
-                self.light_theme = self.theme.clone();
-            }
-            None => {}
-        }
-    }
-
-    /// The theme to show: the light or dark family's choice by the mode; Auto follows `system_light`
-    /// (`None` = the system said nothing: dark).
-    pub fn resolved_theme(&self, system_light: Option<bool>) -> &str {
-        let light = match self.appearance_mode.as_str() {
-            "light" => true,
-            "auto" => system_light == Some(true),
-            _ => false,
-        };
-        if light { &self.light_theme } else { &self.dark_theme }
-    }
-}
-
-impl Prefs {
-    /// Parse a settings document (migrating older layouts; unknown keys are kept, bad values
-    /// fall back to defaults).
-    pub fn from_json(text: &str) -> Prefs {
-        let v: Value = serde_json::from_str(text).unwrap_or_else(|_| json!({}));
-        let v = migrate(v);
-        let mut p: Prefs = match serde_json::from_value(v.clone()) {
-            Ok(p) => p,
-            // One bad value shouldn't lose everything: take each page that parses.
-            Err(_) => {
-                let mut base = serde_json::to_value(Prefs::default()).unwrap_or_default();
-                if let (Some(b), Some(o)) = (base.as_object_mut(), v.as_object()) {
-                    for (k, x) in o {
-                        let mut trial = b.clone();
-                        trial.insert(k.clone(), x.clone());
-                        if serde_json::from_value::<Prefs>(Value::Object(trial)).is_ok() {
-                            b.insert(k.clone(), x.clone());
-                        }
-                    }
-                }
-                serde_json::from_value(base).unwrap_or_default()
-            }
-        };
-        p.normalize();
-        p
-    }
-
-    pub fn to_json(&self) -> String {
-        serde_json::to_string_pretty(self).unwrap_or_default()
-    }
-
-    /// Clamp values into their valid ranges and fill missing labels.
-    pub fn normalize(&mut self) {
-        self.version = PREFS_VERSION;
-        self.comp_presets.retain(CompPreset::is_valid);
-        let mut seen = std::collections::HashSet::new();
-        self.effects_favorites.retain(|id| !id.is_empty() && seen.insert(id.clone()));
-        self.effects_favorites.truncate(MAX_EFFECTS_FAVORITES);
-        if !is_choice(WINDOW_GRAPHICS, &self.startup.window_graphics) {
-            self.startup.window_graphics = Startup::default().window_graphics;
-        }
-        let g = &mut self.general;
-        if !is_choice(LANGUAGES, &g.language) {
-            g.language = General::default().language;
-        }
-        g.undo_levels = g.undo_levels.clamp(1, 99);
-        g.path_point_size = g.path_point_size.clamp(3, 20);
-        g.recent_items = g.recent_items.clamp(1, 30);
-        let a = &mut self.auto_save;
-        a.interval_minutes = a.interval_minutes.clamp(1, 240);
-        a.max_versions = a.max_versions.clamp(1, 99);
-        let ap = &mut self.appearance;
-        let mut seen = std::collections::BTreeSet::new();
-        ap.favorite_themes.retain(|id| is_choice(THEMES, id) && seen.insert(id.clone()));
-        if !is_choice(APPEARANCE_MODES, &ap.appearance_mode) {
-            ap.appearance_mode = Appearance::default().appearance_mode;
-        }
-        if !is_choice(DARK_THEMES, &ap.dark_theme) {
-            ap.dark_theme = Appearance::default().dark_theme;
-        }
-        if !is_choice(LIGHT_THEMES, &ap.light_theme) {
-            ap.light_theme = Appearance::default().light_theme;
-        }
-        // The legacy single theme mirrors the theme a fixed mode shows (Auto depends on the
-        // system, so it keeps the last one).
-        match ap.appearance_mode.as_str() {
-            "dark" => ap.theme = ap.dark_theme.clone(),
-            "light" => ap.theme = ap.light_theme.clone(),
-            _ if !is_choice(THEMES, &ap.theme) => ap.theme = ap.dark_theme.clone(),
-            _ => {}
-        }
-        self.appearance.brightness = self.appearance.brightness.clamp(-1.0, 1.0);
-        self.appearance.ui_scale = self.appearance.ui_scale.clamp(75, 200);
-        let defaults = default_labels();
-        self.labels.truncate(defaults.len());
-        for d in defaults.iter().skip(self.labels.len()) {
-            self.labels.push(d.clone());
-        }
-        for (l, d) in self.labels.iter_mut().zip(&defaults) {
-            if parse_hex(&l.color).is_none() {
-                l.color = d.color.clone();
-            }
-        }
-        let m = &mut self.memory;
-        m.layer_cache_mb = m.layer_cache_mb.clamp(64, 1 << 20);
-        m.media_cache_mb = m.media_cache_mb.clamp(64, 1 << 20);
-        m.preview_cache_mb = m.preview_cache_mb.clamp(64, 1 << 20);
-        self.grids.grid_spacing = self.grids.grid_spacing.clamp(1.0, 10_000.0);
-        let n = self.general.recent_items as usize;
-        self.recent_projects.truncate(n);
-    }
-
-    /// The value at a dotted key (`general.undoLevels`, `labels.3.color`); `""` = everything.
-    pub fn get(&self, key: &str) -> Option<Value> {
-        let v = serde_json::to_value(self).ok()?;
-        if key.is_empty() {
-            return Some(v);
-        }
-        let ptr = format!("/{}", key.replace('.', "/"));
-        v.pointer(&ptr).cloned()
-    }
-
-    /// Set the value at a dotted key. The key must exist and the value must have its type.
-    pub fn set(&mut self, key: &str, value: Value) -> Result<(), String> {
-        if let Some(c) = choices(key)
-            && !value.as_str().is_some_and(|v| is_choice(c, v))
-        {
-            let all: Vec<&str> = c.iter().map(|(_, v)| *v).collect();
-            return Err(format!("`{key}` expects one of {}", all.join(", ")));
-        }
-        let favorites = if key == "appearance.favoriteThemes" {
-            Some(&value)
-        } else if key == "appearance" {
-            value.get("favoriteThemes")
-        } else {
-            None
-        };
-        if let Some(favorites) = favorites {
-            let values = favorites.as_array().ok_or("favorite themes must be a list")?;
-            let mut seen = std::collections::BTreeSet::new();
-            for value in values {
-                let id = value.as_str().ok_or("favorite theme must be a string")?;
-                if !is_choice(THEMES, id) || !seen.insert(id) {
-                    return Err("unknown or duplicate favorite theme".into());
-                }
-            }
-        }
-        // Older clients set the single theme (by key, or inside the page object): it still picks
-        // a visible theme, fixing the mode to its family.
-        let legacy_theme = key == "appearance.theme" || (key == "appearance" && value.get("theme").is_some() && value.get("appearanceMode").is_none());
-        let mut v = serde_json::to_value(&*self).map_err(|e| e.to_string())?;
-        let ptr = format!("/{}", key.replace('.', "/"));
-        let slot = v.pointer_mut(&ptr).ok_or_else(|| format!("unknown setting `{key}`"))?;
-        let value = coerce(slot, value).ok_or_else(|| format!("`{key}` expects a {}", kind_name(slot)))?;
-        *slot = value;
-        let mut next: Prefs = serde_json::from_value(v).map_err(|e| format!("`{key}`: {e}"))?;
-        let (a, b) = (&self.appearance, &next.appearance);
-        let only_theme_changed = a.theme != b.theme && a.appearance_mode == b.appearance_mode && a.dark_theme == b.dark_theme && a.light_theme == b.light_theme;
-        if legacy_theme || only_theme_changed {
-            next.appearance.select_theme();
-        }
-        next.normalize();
-        *self = next;
-        Ok(())
-    }
-
-    /// Reset one page (`general`, `labels`, `autoSave`…) or everything (`None`). Open Recent and
-    /// the saved composition presets are kept.
-    pub fn reset(&mut self, page: Option<&str>) -> Result<(), String> {
-        let d = Prefs::default();
-        let Some(page) = page else {
-            *self = Prefs {
-                recent_projects: std::mem::take(&mut self.recent_projects),
-                recent_footage: std::mem::take(&mut self.recent_footage),
-                recent_presets: std::mem::take(&mut self.recent_presets),
-                recent_fonts: std::mem::take(&mut self.recent_fonts),
-                effects_favorites: std::mem::take(&mut self.effects_favorites),
-                preview: std::mem::take(&mut self.preview),
-                comp_presets: std::mem::take(&mut self.comp_presets),
-                ..d
-            };
-            return Ok(());
-        };
-        let keys: Vec<&str> = match page {
-            "project" => vec!["project", "autoSave"],
-            p => vec![section_key(p).ok_or_else(|| format!("unknown settings page `{p}`"))?],
-        };
-        let dv = serde_json::to_value(&d).map_err(|e| e.to_string())?;
-        for k in keys {
-            if let Some(x) = dv.get(k) {
-                self.set(k, x.clone())?;
-            }
-        }
-        Ok(())
-    }
-
-    /// Display name of a label (Labels settings).
-    pub fn label_name(&self, l: Label) -> String {
-        match label_index(l) {
-            Some(i) => self.labels.get(i).map(|p| p.name.clone()).unwrap_or_else(|| l.name().to_string()),
-            None => l.name().to_string(),
-        }
-    }
-
-    /// sRGB colour of a label (Labels settings).
-    pub fn label_rgb(&self, l: Label) -> [u8; 3] {
-        label_index(l).and_then(|i| self.labels.get(i)).and_then(|p| parse_hex(&p.color)).unwrap_or(l.rgb())
-    }
-
-    /// A label by its built-in name or its (renamed) display name.
-    pub fn label_from_name(&self, s: &str) -> Option<Label> {
-        Label::from_name(s).or_else(|| Label::ALL.iter().skip(1).copied().find(|l| self.label_name(*l).eq_ignore_ascii_case(s)))
-    }
-
-    /// Remember a project in File ▸ Open Recent.
-    pub fn push_recent(&mut self, path: &str) {
-        self.recent_projects.retain(|p| p != path);
-        self.recent_projects.insert(0, path.to_string());
-        self.recent_projects.truncate(self.general.recent_items as usize);
-    }
-
-    /// Layer / media / preview cache budgets in bytes.
-    pub fn layer_cache_bytes(&self) -> usize {
-        (self.memory.layer_cache_mb as usize) << 20
-    }
-    pub fn media_cache_bytes(&self) -> usize {
-        (self.memory.media_cache_mb as usize) << 20
-    }
-    pub fn preview_cache_bytes(&self) -> usize {
-        (self.memory.preview_cache_mb as usize) << 20
-    }
-
-    /// The adaptive resolution limit as a render-scale floor (1/2 → 0.5).
-    pub fn adaptive_limit(&self) -> f64 {
-        match self.previews.adaptive_resolution_limit.as_str() {
-            "1/2" => 0.5,
-            "1/4" => 0.25,
-            _ => 0.125,
-        }
-    }
-
-    /// The Memory & CPU cache budgets in effect: the configured layer / footage / preview
-    /// budgets, scaled down so together they leave **RAM Reserved for Other Applications** free,
-    /// and halved while the system is low on memory when **Reduce Cache Size When System Is Low
-    /// on Memory** is on. `mem` = the system's memory (`None` = unknown: configured budgets).
-    /// In the browser the layer and footage caches also stay within [`WEB_LAYER_CACHE`] and
-    /// [`WEB_MEDIA_CACHE`].
-    pub fn cache_budgets(&self, mem: Option<crate::sysinfo::SysMemory>) -> CacheBudgets {
-        self.cache_budgets_in(mem, cfg!(target_arch = "wasm32"))
-    }
-
-    /// [`Prefs::cache_budgets`], in the browser's memory (`web`) or not.
-    pub(crate) fn cache_budgets_in(&self, mem: Option<crate::sysinfo::SysMemory>, web: bool) -> CacheBudgets {
-        let (mut l, mut m, mut p) = (self.layer_cache_bytes() as u64, self.media_cache_bytes() as u64, self.preview_cache_bytes() as u64);
-        if web {
-            (l, m) = (l.min(WEB_LAYER_CACHE), m.min(WEB_MEDIA_CACHE));
-        }
-        let floor = 64u64 << 20;
-        let mut capped = false;
-        let mut reduced = false;
-        if let Some(mem) = mem.filter(|m| m.total > 0) {
-            let reserved = (self.memory.ram_reserved_gb as u64) << 30;
-            let cap = mem.total.saturating_sub(reserved).max(3 * floor);
-            let sum = l + m + p;
-            if sum > cap {
-                let k = cap as f64 / sum as f64;
-                (l, m, p) = ((l as f64 * k) as u64, (m as f64 * k) as u64, (p as f64 * k) as u64);
-                capped = true;
-            }
-            if self.memory.reduce_cache_when_low && mem.is_low() {
-                (l, m, p) = (l / 2, m / 2, p / 2);
-                reduced = true;
-            }
-        }
-        CacheBudgets { layer: l.max(floor) as usize, media: m.max(floor) as usize, preview: p.max(floor) as usize, capped, reduced }
-    }
-
-    /// Composition ▸ Motion Path: the layer-time span of a motion path to draw around `now`
-    /// (layer time), for keyframes at `keys` (sorted). `None` = No Motion Path.
-    pub fn motion_path_span(&self, keys: &[Tick], now: Tick) -> Option<(Tick, Tick)> {
-        let (first, last) = (*keys.first()?, *keys.last()?);
-        let c = &self.composition;
-        match c.motion_path.as_str() {
-            "none" => None,
-            "seconds" => {
-                let half = Tick::from_seconds_f64(c.motion_path_seconds.max(0.0) / 2.0);
-                let (a, b) = ((now - half).max(first), (now + half).min(last));
-                (a < b).then_some((a, b))
-            }
-            "keyframes" => {
-                let n = (c.motion_path_keyframes.max(1) as usize).min(keys.len());
-                if n < 2 {
-                    return None;
-                }
-                // The n keyframes centred on the current time.
-                let at = keys.partition_point(|k| *k < now);
-                let start = at.saturating_sub(n / 2).min(keys.len() - n);
-                Some((keys[start], keys[start + n - 1]))
-            }
-            _ => Some((first, last)),
-        }
-    }
-
-    /// Previews ▸ Viewer Zoom Quality: smooth (bilinear) scaling of the viewer image, or nearest
-    /// neighbour ("Faster").
-    pub fn viewer_zoom_smooth(&self) -> bool {
-        self.previews.zoom_quality != "faster"
-    }
-
-    /// Import ▸ Interpret Unlabeled Alpha As, for footage whose file has an alpha channel that
-    /// doesn't state how it is stored. `None` = Ask User (keep straight and open Interpret
-    /// Footage); `guess` takes premultiplied for movies (codecs with alpha are usually written
-    /// premultiplied) and straight for stills.
-    pub fn unlabeled_alpha(&self, movie: bool) -> Option<effectcraft_project::AlphaMode> {
-        use effectcraft_project::AlphaMode::*;
-        Some(match self.import.unlabeled_alpha.as_str() {
-            "ignore" => Ignore,
-            "straight" => Straight,
-            "premultiplied" => Premultiplied,
-            "guess" if movie => Premultiplied,
-            "guess" => Straight,
-            _ => return None,
-        })
-    }
-
-    /// Import ▸ Default Drag Import As, as `file.import`'s `importAs`.
-    pub fn drag_import_as(&self) -> &'static str {
-        match self.import.drag_import_as.as_str() {
-            "comp" => "composition",
-            "compLayerSizes" => "compositionLayerSizes",
-            _ => "footage",
-        }
-    }
-
-    /// Export ▸ Append Bit Depth to File Name: `Comp 1.png` → `Comp 1_16bpc.png` (sequence frame
-    /// runs and folders are kept).
-    pub fn output_name(&self, path: &str, bits: u32) -> String {
-        if !self.export.append_bits_to_name {
-            return path.to_string();
-        }
-        let p = std::path::Path::new(path);
-        let (Some(stem), dir) = (p.file_stem().map(|s| s.to_string_lossy().to_string()), p.parent()) else { return path.to_string() };
-        let tag = format!("_{bits}bpc");
-        if stem.ends_with(&tag) {
-            return path.to_string();
-        }
-        let name = match p.extension() {
-            Some(e) => format!("{stem}{tag}.{}", e.to_string_lossy()),
-            None => format!("{stem}{tag}"),
-        };
-        match dir.filter(|d| !d.as_os_str().is_empty()) {
-            Some(d) => d.join(name).to_string_lossy().to_string(),
-            None => name,
-        }
-    }
-
-    /// Export ▸ Segment Sequences / Segment Movie Files: how many frames go in each segment of an
-    /// output of `frames` frames (`None` = one file / folder). Sequences split every Files per
-    /// Segment frames; movies every Segment Size MB at the output's data rate
-    /// (`bytes_per_frame`, estimated from the format's bitrate).
-    pub fn segment_frames(&self, frames: u64, sequence: bool, bytes_per_frame: f64) -> Option<u64> {
-        let e = &self.export;
-        let per = if sequence {
-            e.segment_sequences.then_some(e.segment_sequence_files.max(1) as u64)?
-        } else {
-            if !e.segment_movies || bytes_per_frame <= 0.0 {
-                return None;
-            }
-            (((e.segment_movie_mb.max(1) as f64) * 1_048_576.0 / bytes_per_frame).floor() as u64).max(1)
-        };
-        (per < frames).then_some(per)
-    }
-
-    /// Remember a font in the Character panel's recent fonts (Type ▸ Number of Recent Fonts).
-    pub fn push_recent_font(&mut self, family: &str) {
-        push_mru(&mut self.recent_fonts, family, 30);
-    }
-
-    /// Is effect `id` starred in Effects & Presets?
-    pub fn is_effect_favorite(&self, id: &str) -> bool {
-        self.effects_favorites.iter().any(|f| f == id)
-    }
-
-    /// Star effect `id` in Effects & Presets, or un-star it; true when it is starred now.
-    pub fn toggle_effect_favorite(&mut self, id: &str) -> bool {
-        if self.is_effect_favorite(id) {
-            self.effects_favorites.retain(|f| f != id);
-            false
-        } else {
-            self.effects_favorites.push(id.to_string());
-            self.effects_favorites.truncate(MAX_EFFECTS_FAVORITES);
-            self.is_effect_favorite(id)
-        }
-    }
-
-    /// The recent fonts the Character panel shows (at most Number of Recent Fonts to Display).
-    pub fn recent_fonts_shown(&self) -> &[String] {
-        let n = (self.type_.recent_fonts as usize).min(self.recent_fonts.len());
-        &self.recent_fonts[..n]
-    }
-
-    /// Remember imported footage for File ▸ Import Recent Footage.
-    pub fn push_recent_footage(&mut self, path: &str) {
-        push_mru(&mut self.recent_footage, path, self.general.recent_items as usize);
-    }
-
-    /// Remember an applied animation preset for Animation ▸ Recent Animation Presets.
-    pub fn push_recent_preset(&mut self, path: &str) {
-        push_mru(&mut self.recent_presets, path, self.general.recent_items as usize);
-    }
-}
-
-/// Most effects Effects & Presets keeps starred (a hand-edited settings file can hold more).
-const MAX_EFFECTS_FAVORITES: usize = 1000;
-
-fn push_mru(list: &mut Vec<String>, v: &str, max: usize) {
-    list.retain(|x| x != v);
-    list.insert(0, v.to_string());
-    list.truncate(max.max(1));
-}
-
-/// The most the layer cache holds in the browser. A wasm32 page addresses at most 4 GiB, which
-/// these caches share with the app and with the decoders' own decoded frames (FilmCraft keeps
-/// up to 384 MB per open movie): with the desktop's 1 GB defaults, eight stacked 1080p clips ran
-/// the page out of memory a few seconds into playback.
-pub const WEB_LAYER_CACHE: u64 = 512 << 20;
-
-/// The most the footage frame cache holds in the browser (see [`WEB_LAYER_CACHE`]).
-pub const WEB_MEDIA_CACHE: u64 = 256 << 20;
-
-/// Effective cache budgets in bytes (see [`Prefs::cache_budgets`]).
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize)]
-pub struct CacheBudgets {
-    pub layer: usize,
-    pub media: usize,
-    pub preview: usize,
-    /// Scaled down to leave the reserved RAM free.
-    pub capped: bool,
-    /// Halved because the system is low on memory.
-    pub reduced: bool,
-}
-
-/// Colour of the `k`-th mask of a layer: Appearance ▸ Cycle Mask Colors cycles through the mask
-/// colours, otherwise every new mask takes the first one.
-pub fn mask_color(cycle: bool, k: usize) -> [u8; 3] {
-    use effectcraft_project::build::MASK_COLORS;
-    if cycle { MASK_COLORS[k % MASK_COLORS.len()] } else { MASK_COLORS[0] }
-}
-
-fn label_index(l: Label) -> Option<usize> {
-    Label::ALL.iter().position(|x| *x == l).and_then(|i| i.checked_sub(1))
-}
-
-/// Settings key of a page id (`3d` → `threeD`).
-pub fn section_key(page: &str) -> Option<&'static str> {
-    Some(match page {
-        "general" => "general",
-        "startup" => "startup",
-        "project" => "project",
-        "autoSave" | "autosave" => "autoSave",
-        "composition" | "display" => "composition",
-        "previews" => "previews",
-        "appearance" => "appearance",
-        "grids" => "grids",
-        "labels" => "labels",
-        "type" => "type",
-        "import" => "import",
-        "export" => "export",
-        "audio" => "audio",
-        "disk" => "disk",
-        "memory" => "memory",
-        "video" => "video",
-        "3d" | "threeD" => "threeD",
-        "scripting" => "scripting",
-        "roto" => "roto",
-        "face" => "face",
-        _ => return None,
-    })
-}
-
-/// Settings page id for a page name, including older After Effects page names
-/// (Auto-Save → Project, Media & Disk Cache → Disk, Memory & Performance → Memory & CPU…).
-pub fn page_id(name: &str) -> Option<&'static str> {
-    let n = name.to_ascii_lowercase().replace([' ', '&', '-', '_'], "");
-    let id = match n.as_str() {
-        "general" => "general",
-        "startup" | "startuprepair" => "startup",
-        "project" | "autosave" | "newproject" => "project",
-        "composition" | "display" => "composition",
-        "previews" | "preview" => "previews",
-        "appearance" => "appearance",
-        "grids" | "gridsguides" => "grids",
-        "labels" => "labels",
-        "type" => "type",
-        "import" => "import",
-        "export" | "output" => "export",
-        "audio" | "audiohardware" | "audiooutputmapping" => "audio",
-        "disk" | "mediadiskcache" | "mediacache" => "disk",
-        "memory" | "memorycpu" | "memoryperformance" => "memory",
-        "video" | "videopreview" => "video",
-        "3d" | "threed" => "3d",
-        "scripting" | "scriptingexpressions" => "scripting",
-        "roto" | "rotobrush" | "models" => "roto",
-        "face" | "facetracking" => "face",
-        _ => return None,
-    };
-    Some(id)
-}
-
-fn kind_name(v: &Value) -> &'static str {
-    match v {
-        Value::Bool(_) => "boolean",
-        Value::Number(_) => "number",
-        Value::String(_) => "string",
-        Value::Array(_) => "list",
-        Value::Object(_) => "object",
-        Value::Null => "value",
-    }
-}
-
-/// `value` converted to the type of `slot` (numbers from strings, booleans from 0/1…).
-fn coerce(slot: &Value, value: Value) -> Option<Value> {
-    Some(match (slot, value) {
-        (Value::Bool(_), Value::Bool(b)) => json!(b),
-        (Value::Bool(_), Value::Number(n)) => json!(n.as_f64()? != 0.0),
-        (Value::Bool(_), Value::String(s)) => json!(matches!(s.as_str(), "true" | "on" | "1" | "yes")),
-        (Value::Number(cur), v) => {
-            let f = match &v {
-                Value::Number(n) => n.as_f64()?,
-                Value::String(s) => s.trim().parse().ok()?,
-                _ => return None,
-            };
-            if cur.is_u64() || cur.is_i64() { json!(f.round().max(0.0) as u64) } else { json!(f) }
-        }
-        (Value::String(_), Value::String(s)) => json!(s),
-        (Value::String(_), Value::Number(n)) => json!(n.to_string()),
-        (Value::Array(_), v @ Value::Array(_)) => v,
-        (Value::Object(_), v @ Value::Object(_)) => v,
-        _ => return None,
-    })
-}
-
-// ---------------------------------------------------------------- schema (Settings dialog)
-
-/// What a setting row edits.
-#[derive(Clone, Copy, Debug, PartialEq)]
-pub enum Kind {
-    Bool,
-    /// Integer with range and unit.
-    Int(i64, i64, &'static str),
-    /// Number with range and unit.
-    Float(f64, f64, &'static str),
-    /// One of (label, value).
-    Choice(&'static [(&'static str, &'static str)]),
-    Text,
-    /// A folder or file path (text + Choose…).
-    Path,
-    /// `#rrggbb`.
-    Color,
-    /// UI brightness slider.
-    Slider(f64, f64),
-}
-
-/// One row of a settings page.
-#[derive(Clone, Copy, Debug, PartialEq)]
-pub enum Item {
-    Section(&'static str),
-    Setting {
-        key: &'static str,
-        label: &'static str,
-        kind: Kind,
-        /// Changes behaviour today (false = shown for parity, listed in docs/preferences.md).
-        live: bool,
-    },
-    /// A button running a command (`params` is JSON).
-    Button {
-        label: &'static str,
-        command: &'static str,
-        params: &'static str,
-    },
-    /// The 16 label names and colours.
-    Labels,
-    /// Output device picker (device list from the host).
-    AudioDevices {
-        key: &'static str,
-    },
-    /// Read-only information line.
-    Note(&'static str),
-    /// The browser's storage manager (web app only, `storage.*`): usage and quota, persistent
-    /// storage, Clear buttons. Not shown where there is no browser storage.
-    BrowserStorage,
-    /// A task's trained models (`roto.models`, `face.models`): authors, licence, size, install,
-    /// choose.
-    Models(effectcraft_segment::Task),
-}
-
-/// One page of the Settings dialog.
-#[derive(Clone, Debug)]
-pub struct Page {
-    pub id: &'static str,
-    pub title: &'static str,
-    pub items: Vec<Item>,
-}
-
-const fn s(key: &'static str, label: &'static str, kind: Kind, live: bool) -> Item {
-    Item::Setting { key, label, kind, live }
-}
-
-const B: Kind = Kind::Bool;
-const ON_OFF_RES: &[(&str, &str)] = &[("1/2", "1/2"), ("1/4", "1/4"), ("1/8", "1/8")];
-const STYLES: &[(&str, &str)] = &[("Lines", "lines"), ("Dashed Lines", "dashed"), ("Dots", "dots")];
-
-/// The Settings pages in After Effects 2026 order.
-pub fn pages() -> Vec<Page> {
-    use Item::*;
-    vec![
-        Page {
-            id: "general",
-            title: "General",
-            items: vec![
-                s("general.language", "Language", Kind::Choice(LANGUAGES), true),
-                s("general.undoLevels", "Levels of Undo", Kind::Int(1, 99, ""), true),
-                s("general.pathPointSize", "Path Point and Handle Size", Kind::Int(3, 20, "px"), true),
-                s("general.recentItems", "Recent Projects Shown", Kind::Int(1, 30, ""), true),
-                Section("Options"),
-                s("general.showToolTips", "Show Tool Tips", B, true),
-                s("general.createLayersAtCompStart", "Create Layers at Composition Start Time", B, true),
-                s("general.switchesAffectNestedComps", "Switches Affect Nested Comps", B, true),
-                s("general.defaultSpatialLinear", "Default Spatial Interpolation to Linear", B, true),
-                s("general.preserveConstantVertexCount", "Preserve Constant Vertex and Feather Point Count when Editing Masks", B, true),
-                s("general.syncTimeRelatedItems", "Synchronize Time of All Related Items", B, true),
-                s("general.expressionPickWhipCompact", "Expression Pick Whip Writes Compact English", B, true),
-                s("general.createSplitLayersAbove", "Create Split Layers Above Original Layer", B, true),
-                s("general.useSystemColorPicker", "Use System Color Picker", B, false),
-                Note("EffectCraft always uses its own colour picker (the same on every platform and the web)."),
-            ],
-        },
-        Page {
-            id: "startup",
-            title: "Startup & Repair",
-            items: vec![
-                s("startup.showHomeOnLaunch", "Show Home Screen When Launching", B, true),
-                s("startup.showHomeOnOpenProject", "Show Home Screen When Opening a Project", B, true),
-                s("startup.offerCrashRecovery", "Offer to Open the Latest Auto-Save After a Crash", B, true),
-                s("startup.windowGraphics", "Window Graphics", Kind::Choice(WINDOW_GRAPHICS), true),
-                Note(
-                    "Window Graphics applies from the next launch. When the graphics driver stops EffectCraft as its window opens, the next launch switches to OpenGL.",
-                ),
-                Section("Repair"),
-                Button { label: "Reset Settings", command: "prefs.reset", params: "{}" },
-                Button { label: "Reset Keyboard Shortcuts", command: "shortcuts.reset", params: "{}" },
-                Button { label: "Empty Disk Cache", command: "edit.purge", params: r#"{"what":"disk"}"# },
-            ],
-        },
-        Page {
-            id: "project",
-            title: "Project",
-            items: vec![
-                Section("New Project"),
-                s("project.useTemplate", "New Project Loads Template", B, true),
-                s("project.templatePath", "Template Project", Kind::Path, true),
-                Section("Auto-Save"),
-                s("autoSave.enabled", "Automatically Save Projects", B, true),
-                s("autoSave.intervalMinutes", "Save Every", Kind::Int(1, 240, "Minutes"), true),
-                s("autoSave.maxVersions", "Maximum Project Versions", Kind::Int(1, 99, ""), true),
-                s("autoSave.location", "Auto-Save Location", Kind::Choice(&[("Next to Project", "nextToProject"), ("Custom Location", "custom")]), true),
-                s("autoSave.folder", "Custom Location", Kind::Path, true),
-                s("autoSave.saveOnRenderStart", "Save When Starting Render Queue", B, true),
-                Button { label: "Save Now", command: "file.autoSave", params: "{}" },
-            ],
-        },
-        Page {
-            id: "composition",
-            title: "Composition",
-            items: vec![
-                Section("Motion Path"),
-                s(
-                    "composition.motionPath",
-                    "Motion Path",
-                    Kind::Choice(&[
-                        ("All Keyframes", "all"),
-                        ("No Motion Path", "none"),
-                        ("No More Than (Seconds)", "seconds"),
-                        ("No More Than (Keyframes)", "keyframes"),
-                    ]),
-                    true,
-                ),
-                s("composition.motionPathSeconds", "Seconds", Kind::Float(0.0, 3600.0, "s"), true),
-                s("composition.motionPathKeyframes", "Keyframes", Kind::Int(1, 10_000, ""), true),
-                Section("Display"),
-                s("composition.showRenderingProgress", "Show Rendering Progress in Info Panel and Flowchart", B, true),
-                s("composition.hardwareAcceleratePanels", "Hardware Accelerate Composition, Layer and Footage Panels", B, false),
-                Note("Panels are always drawn by the GPU (wgpu)."),
-            ],
-        },
-        Page {
-            id: "previews",
-            title: "Previews",
-            items: vec![
-                s("previews.adaptiveResolutionLimit", "Adaptive Resolution Limit", Kind::Choice(ON_OFF_RES), true),
-                s("previews.showInternalWireframes", "Show Internal Wireframes", B, true),
-                s("previews.cacheFramesWhenIdle", "Cache Frames When Idle", B, true),
-                s("previews.fastPreviews", "Fast Previews (Draft 3D, Faster Effects)", B, true),
-                s("previews.zoomQuality", "Viewer Zoom Quality", Kind::Choice(&[("Faster", "faster"), ("More Accurate", "moreAccurate")]), true),
-                s("previews.displayProfile", "Display Color Space", Kind::Choice(&[("sRGB", "srgb"), ("Display P3", "p3")]), true),
-                Button { label: "GPU Information...", command: "app.gpuInfo", params: "{}" },
-            ],
-        },
-        Page {
-            id: "appearance",
-            title: "Appearance",
-            items: vec![
-                s("appearance.appearanceMode", "Appearance Mode", Kind::Choice(APPEARANCE_MODES), true),
-                s("appearance.lightTheme", "Light Theme", Kind::Choice(LIGHT_THEMES), true),
-                s("appearance.darkTheme", "Dark Theme", Kind::Choice(DARK_THEMES), true),
-                s("appearance.brightness", "Brightness", Kind::Slider(-1.0, 1.0), true),
-                s("appearance.uiScale", "UI Scale", Kind::Int(75, 200, "%"), true),
-                Section("Labels and Colors"),
-                s("appearance.useLabelColorForHandles", "Use Label Color for Layer Handles and Paths", B, true),
-                s("appearance.useLabelColorForTabs", "Use Label Color for Related Tabs", B, true),
-                s("appearance.cycleMaskColors", "Cycle Mask Colors", B, true),
-                s("appearance.useGradients", "Use Gradients", B, true),
-                Section("Menu Bar"),
-                s("appearance.inWindowMenuBarMac", "Use In-Window Menu Bar on macOS", B, true),
-            ],
-        },
-        Page {
-            id: "grids",
-            title: "Grids & Guides",
-            items: vec![
-                Section("Grid"),
-                s("grids.gridColor", "Color", Kind::Color, true),
-                s("grids.gridSpacing", "Gridline Every", Kind::Float(1.0, 10_000.0, "px"), true),
-                s("grids.gridSubdivisions", "Subdivisions", Kind::Int(1, 100, ""), true),
-                s("grids.gridStyle", "Style", Kind::Choice(STYLES), true),
-                Section("Proportional Grid"),
-                s("grids.proportionalHorizontal", "Horizontal", Kind::Int(1, 100, ""), true),
-                s("grids.proportionalVertical", "Vertical", Kind::Int(1, 100, ""), true),
-                Section("Guides"),
-                s("grids.guideColor", "Color", Kind::Color, true),
-                s("grids.guideStyle", "Style", Kind::Choice(STYLES), true),
-                Section("Safe Margins"),
-                s("grids.actionSafe", "Action-safe", Kind::Float(0.0, 50.0, "%"), true),
-                s("grids.titleSafe", "Title-safe", Kind::Float(0.0, 50.0, "%"), true),
-            ],
-        },
-        Page { id: "labels", title: "Labels", items: vec![Labels] },
-        Page {
-            id: "type",
-            title: "Type",
-            items: vec![
-                s("type.textEngine", "Text Engine", Kind::Choice(&[("Latin", "latin"), ("South Asian and Middle Eastern", "southAsian")]), true),
-                s("type.fontPreview", "Show Font Preview", B, true),
-                s("type.recentFonts", "Number of Recent Fonts to Display", Kind::Int(0, 30, ""), true),
-                s("type.fontNamesInEnglish", "Show Font Names in English", B, true),
-            ],
-        },
-        Page {
-            id: "import",
-            title: "Import",
-            items: vec![
-                s("import.stillFootage", "Still Footage", Kind::Choice(&[("Length of Composition", "compLength"), ("Duration (Seconds)", "seconds")]), true),
-                s("import.stillSeconds", "Still Duration", Kind::Float(0.04, 86_400.0, "s"), true),
-                s("import.sequenceFps", "Sequence Footage", Kind::Float(1.0, 999.0, "frames per second"), true),
-                s("import.reportMissingFrames", "Report Missing Frames", B, true),
-                s(
-                    "import.autoReloadFootage",
-                    "Automatically Reload Footage",
-                    Kind::Choice(&[("Off", "off"), ("Non-Sequence Footage", "nonSequence"), ("All Footage", "all")]),
-                    true,
-                ),
-                s(
-                    "import.unlabeledAlpha",
-                    "Interpret Unlabeled Alpha As",
-                    Kind::Choice(&[
-                        ("Ask User", "ask"),
-                        ("Guess", "guess"),
-                        ("Ignore", "ignore"),
-                        ("Straight", "straight"),
-                        ("Premultiplied", "premultiplied"),
-                    ]),
-                    true,
-                ),
-                s(
-                    "import.dragImportAs",
-                    "Default Drag Import As",
-                    Kind::Choice(&[("Footage", "footage"), ("Composition", "comp"), ("Composition - Retain Layer Sizes", "compLayerSizes")]),
-                    true,
-                ),
-            ],
-        },
-        Page {
-            id: "export",
-            title: "Export",
-            items: vec![
-                s("export.defaultOutputFolder", "Default Output Folder", Kind::Path, true),
-                s("export.segmentSequences", "Segment Sequences", B, true),
-                s("export.segmentSequenceFiles", "Files per Segment", Kind::Int(1, 100_000, "files"), true),
-                s("export.segmentMovies", "Segment Movie Files", B, true),
-                s("export.segmentMovieMb", "Segment Size", Kind::Int(1, 1_000_000, "MB"), true),
-                s("export.appendBitsToName", "Append Bit Depth to File Name", B, true),
-            ],
-        },
-        Page {
-            id: "audio",
-            title: "Audio",
-            items: vec![
-                Section("Audio Hardware"),
-                AudioDevices { key: "audio.outputDevice" },
-                s("audio.previewSampleRate", "Preview Sample Rate", Kind::Int(8_000, 192_000, "Hz"), true),
-                Section("Audio Output Mapping"),
-                s("audio.outputLeft", "Left", Kind::Int(1, 64, "channel"), true),
-                s("audio.outputRight", "Right", Kind::Int(1, 64, "channel"), true),
-            ],
-        },
-        Page {
-            id: "disk",
-            title: "Disk",
-            items: vec![
-                Section("Disk Cache"),
-                s("disk.diskCacheEnabled", "Enable Disk Cache", B, true),
-                s("disk.diskCacheMaxGb", "Maximum Disk Cache Size", Kind::Int(1, 100_000, "GB"), true),
-                s("disk.diskCacheFolder", "Disk Cache Folder", Kind::Path, true),
-                Button { label: "Empty Disk Cache", command: "edit.purge", params: r#"{"what":"disk"}"# },
-                BrowserStorage,
-                Section("Media Cache"),
-                s("disk.mediaCacheFolder", "Database and Cache Folder", Kind::Path, true),
-                s("disk.conformedMediaFolder", "Conformed Audio Folder", Kind::Path, true),
-            ],
-        },
-        Page {
-            id: "memory",
-            title: "Memory & CPU",
-            items: vec![
-                s("memory.ramReservedGb", "RAM Reserved for Other Applications", Kind::Int(0, 1024, "GB"), true),
-                Section("Cache Budgets"),
-                s("memory.layerCacheMb", "Layer Cache", Kind::Int(64, 1 << 20, "MB"), true),
-                s("memory.mediaCacheMb", "Footage Frame Cache", Kind::Int(64, 1 << 20, "MB"), true),
-                s("memory.previewCacheMb", "Preview (RAM) Cache", Kind::Int(64, 1 << 20, "MB"), true),
-                s("memory.reduceCacheWhenLow", "Reduce Cache Size When System Is Low on Memory", B, true),
-            ],
-        },
-        Page {
-            id: "video",
-            title: "Video",
-            items: vec![
-                s("video.enableOutput", "Enable Video Preview Output", B, true),
-                s("video.device", "Video Device", Kind::Choice(&[("Floating Window", ""), ("Full Screen", "fullscreen")]), true),
-                s("video.outputDuringPlayback", "Video Output During Playback", B, true),
-                s("video.mirrorOnMonitor", "Mirror on Computer Monitor", B, true),
-                s("video.disableWhenBackground", "Disable Video Output When in Background", B, true),
-            ],
-        },
-        Page {
-            id: "3d",
-            title: "3D",
-            items: vec![
-                s("threeD.defaultRenderer", "Default 3D Renderer", Kind::Choice(&[("Classic 3D", "classic"), ("Advanced 3D", "advanced")]), true),
-                s("threeD.showReferenceAxes", "Show 3D Reference Axes", B, true),
-                s("threeD.extendedViewer", "Extended Viewer", B, true),
-                s("threeD.realtimeShadows", "Realtime Shadows in Draft", B, true),
-            ],
-        },
-        Page {
-            id: "scripting",
-            title: "Scripting & Expressions",
-            items: vec![
-                Section("Application Scripting"),
-                s("scripting.allowScriptsWriteFiles", "Allow Scripts to Write Files and Access Network", B, true),
-                s("scripting.warnExecutingFiles", "Warn User When Executing Files", B, true),
-                s("scripting.enableJsDebugger", "Enable JavaScript Debugger", B, false),
-                Section("Expressions Editor"),
-                s("scripting.editorFontSize", "Font Size", Kind::Int(8, 40, "pt"), true),
-                s("scripting.syntaxHighlighting", "Syntax Highlighting", B, true),
-                s("scripting.lineNumbers", "Line Numbers", B, true),
-                s("scripting.autoComplete", "Auto-complete", B, true),
-                s("scripting.bracketMatching", "Bracket Matching", B, true),
-                s("scripting.wordWrap", "Word Wrap", B, true),
-                s("scripting.errorBanner", "Show Expression Error Banner", B, true),
-                Note("Expressions use the JavaScript engine. Script errors report their file and line in the Script Console; there is no step debugger."),
-            ],
-        },
-        Page {
-            id: "roto",
-            title: "Roto Brush",
-            items: vec![
-                Section("Segmentation Model"),
-                Note(
-                    "Roto Brush 2.0 and 3.0 use the model chosen here (Version 1.0 always uses the classic engine). Models are open source, downloaded only when you ask, and checked against their published SHA-256.",
-                ),
-                Models(effectcraft_segment::Task::Mask),
-            ],
-        },
-        Page {
-            id: "face",
-            title: "Face Tracking",
-            items: vec![
-                Section("Face Model"),
-                Note(
-                    "Face tracking in the Tracker panel (Outline Only and Detailed Features) uses the model chosen here. Models are open source, downloaded only when you ask, and checked against their published SHA-256.",
-                ),
-                Models(effectcraft_segment::Task::Face),
-            ],
-        },
-    ]
-}
-
-/// Keys of every setting that doesn't change behaviour yet (the TODO list in
-/// `docs/preferences.md`).
-pub fn todo_keys() -> Vec<&'static str> {
-    pages()
-        .into_iter()
-        .flat_map(|p| p.items)
-        .filter_map(|i| match i {
-            Item::Setting { key, live: false, .. } => Some(key),
-            _ => None,
-        })
-        .collect()
-}
-
-/// The schema as JSON (for `prefs.pages`).
-pub fn pages_json() -> Value {
-    let kind = |k: &Kind| -> Value {
-        match k {
-            Kind::Bool => json!({"type": "bool"}),
-            Kind::Int(a, b, u) => json!({"type": "int", "min": a, "max": b, "unit": u}),
-            Kind::Float(a, b, u) => json!({"type": "number", "min": a, "max": b, "unit": u}),
-            Kind::Choice(o) => json!({"type": "choice", "options": o.iter().map(|(l, v)| json!({"label": l, "value": v})).collect::<Vec<_>>()}),
-            Kind::Text => json!({"type": "text"}),
-            Kind::Path => json!({"type": "path"}),
-            Kind::Color => json!({"type": "color"}),
-            Kind::Slider(a, b) => json!({"type": "slider", "min": a, "max": b}),
-        }
-    };
-    let pages: Vec<Value> = pages()
-        .iter()
-        .map(|p| {
-            let items: Vec<Value> = p
-                .items
-                .iter()
-                .map(|i| match i {
-                    Item::Section(t) => json!({"section": t}),
-                    Item::Setting { key, label, kind: k, live } => {
-                        let mut o = kind(k);
-                        o["key"] = json!(key);
-                        o["label"] = json!(label);
-                        o["live"] = json!(live);
-                        o
-                    }
-                    Item::Button { label, command, params } => {
-                        json!({"button": label, "command": command, "params": serde_json::from_str::<Value>(params).unwrap_or_default()})
-                    }
-                    Item::Labels => json!({"labels": "labels.N.name / labels.N.color (N = 0..15)"}),
-                    Item::AudioDevices { key } => json!({"type": "device", "key": key, "label": "Default Output"}),
-                    Item::Note(t) => json!({"note": t}),
-                    Item::BrowserStorage => json!({"browserStorage": "storage.info / storage.persist / storage.clear (web app)"}),
-                    Item::Models(task) => {
-                        let p = if *task == effectcraft_segment::Task::Face { "face" } else { "roto" };
-                        json!({"models": format!("{p}.models / {p}.model.select / {p}.model.download / {p}.model.install / {p}.model.remove"), "key": format!("{p}.model")})
-                    }
-                })
-                .collect();
-            json!({"id": p.id, "title": p.title, "items": items})
-        })
-        .collect();
-    json!(pages)
-}
diff --git a/crates/engine/src/rq_tests.rs b/crates/engine/src/rq_tests.rs
index 81a187226..4c39cc89e 100644
--- a/crates/engine/src/rq_tests.rs
+++ b/crates/engine/src/rq_tests.rs
@@ -67,11 +67,11 @@ fn add_configure_render() {
     let r = s.execute("renderQueue.setOutputModule", json!({"item": id, "format": "png", "channels": "rgba"})).unwrap();
     assert!(r["outputPath"].as_str().unwrap().ends_with("_[#####].png"), "{r}");
     assert!(s.execute("renderQueue.setOutputModule", json!({"item": id, "format": "jpeg", "channels": "rgba"})).is_err());
-    let r = s.execute("renderQueue.setOutput", json!({"item": id, "path": crate::tests_stubs::tmp_out("rq/out.mov")})).unwrap();
+    let r = s.execute("renderQueue.setOutput", json!({"item": id, "path": crate::tests::stubs::tmp_out("rq/out.mov")})).unwrap();
     assert_eq!(r["output"]["format"], "ProRes", "Output To with .mov switches to ProRes");
-    assert_eq!(std::path::Path::new(r["outputPath"].as_str().unwrap()), std::path::PathBuf::from(crate::tests_stubs::tmp_out("rq/out.mov")));
+    assert_eq!(std::path::Path::new(r["outputPath"].as_str().unwrap()), std::path::PathBuf::from(crate::tests::stubs::tmp_out("rq/out.mov")));
     // A second item that fails, a third that is unqueued.
-    let b = s.execute("renderQueue.add", json!({"format": "gif", "output": crate::tests_stubs::tmp_out("rq/fail.gif")})).unwrap();
+    let b = s.execute("renderQueue.add", json!({"format": "gif", "output": crate::tests::stubs::tmp_out("rq/fail.gif")})).unwrap();
     let c = s.execute("renderQueue.add", json!({"output": "/tmp/rq/skip.mp4"})).unwrap();
     s.execute("renderQueue.setRender", json!({"item": c["item"], "render": false})).unwrap();
     assert_eq!(s.project.render_queue[2].status.label(), "Unqueued");
@@ -79,12 +79,12 @@ fn add_configure_render() {
     assert_eq!(r["items"].as_array().unwrap().len(), 2);
     assert_eq!(
         ex.log.lock().unwrap().iter().map(std::path::PathBuf::from).collect::<Vec<_>>(),
-        [std::path::PathBuf::from(crate::tests_stubs::tmp_out("rq/out.mov")), std::path::PathBuf::from(crate::tests_stubs::tmp_out("rq/fail.gif"))]
+        [std::path::PathBuf::from(crate::tests::stubs::tmp_out("rq/out.mov")), std::path::PathBuf::from(crate::tests::stubs::tmp_out("rq/fail.gif"))]
     );
     let q = &s.project.render_queue;
     assert_eq!(q[0].status.label(), "Done");
     assert!(q[0].started.is_some() && q[0].render_time.is_some());
-    assert_eq!(std::path::Path::new(q[0].last_output.as_deref().unwrap()), std::path::PathBuf::from(crate::tests_stubs::tmp_out("rq/out.mov")));
+    assert_eq!(std::path::Path::new(q[0].last_output.as_deref().unwrap()), std::path::PathBuf::from(crate::tests::stubs::tmp_out("rq/out.mov")));
     assert_eq!(q[1].status, RenderStatus::Failed("boom".into()));
     assert_eq!(q[2].status.label(), "Unqueued");
     let events = s.drain_events();
@@ -130,8 +130,8 @@ fn failure_toast_names_the_first_reason() {
     }
     let mut s = demo();
     s.exporter = Some(Arc::new(Failing));
-    s.execute("renderQueue.add", json!({"format": "gif", "output": crate::tests_stubs::tmp_out("rq/first.gif")})).unwrap();
-    s.execute("renderQueue.add", json!({"format": "gif", "output": crate::tests_stubs::tmp_out("rq/second.gif")})).unwrap();
+    s.execute("renderQueue.add", json!({"format": "gif", "output": crate::tests::stubs::tmp_out("rq/first.gif")})).unwrap();
+    s.execute("renderQueue.add", json!({"format": "gif", "output": crate::tests::stubs::tmp_out("rq/second.gif")})).unwrap();
     s.execute("renderQueue.render", json!({})).unwrap();
     let events = s.drain_events();
     let toast = events.iter().find_map(|e| if let Event::Toast { message, error: true } = e { Some(message.as_str()) } else { None });
diff --git a/crates/engine/src/services.rs b/crates/engine/src/services.rs
new file mode 100644
index 000000000..adbd3ab81
--- /dev/null
+++ b/crates/engine/src/services.rs
@@ -0,0 +1,72 @@
+use super::config;
+
+/// Host services (file access) injected by the frontend.
+pub trait Services: Send + Sync {
+    fn read_file(&self, path: &str) -> std::io::Result<Vec<u8>>;
+    fn write_file(&self, path: &str, data: &[u8]) -> std::io::Result<()>;
+    /// Whether a file exists (the background footage check after open).
+    fn exists(&self, path: &str) -> bool {
+        std::path::Path::new(path).exists()
+    }
+    /// A file's size and modification time (nanoseconds since 1970), to notice that it changed
+    /// on disk (Settings ▸ Import ▸ Reload Footage Changed on Disk); `None` when it can't be read.
+    fn stamp(&self, path: &str) -> Option<(u64, u128)> {
+        let meta = std::fs::metadata(path).ok()?;
+        let modified = meta.modified().ok()?.duration_since(std::time::UNIX_EPOCH).ok()?;
+        Some((meta.len(), modified.as_nanos()))
+    }
+    /// Keep a file the app made for itself (footage extracted from a template): like
+    /// [`Services::write_file`], creating its folder, but never offered as a download (web: it
+    /// goes to browser storage only).
+    fn store_file(&self, path: &str, data: &[u8]) -> std::io::Result<()> {
+        if let Some(d) = std::path::Path::new(path).parent().filter(|d| !d.as_os_str().is_empty()) {
+            let _ = std::fs::create_dir_all(d);
+        }
+        self.write_file(path, data)
+    }
+    /// The files in folder `dir` (full paths; no folders, no hidden files), for image-sequence
+    /// detection on import. Empty when it can't be read.
+    fn list_dir(&self, dir: &str) -> Vec<String> {
+        let Ok(rd) = std::fs::read_dir(if dir.is_empty() { "." } else { dir }) else { return vec![] };
+        rd.filter_map(|e| e.ok())
+            .filter(|e| e.file_type().is_ok_and(|t| t.is_file()) && !e.file_name().to_string_lossy().starts_with('.'))
+            .map(|e| e.path().to_string_lossy().to_string())
+            .collect()
+    }
+    /// Whether `path` is a folder (dropped or picked folders import their files).
+    fn is_dir(&self, path: &str) -> bool {
+        std::path::Path::new(path).is_dir()
+    }
+    /// `path` as a list of recent files keeps it (File ▸ Scripts ▸ Recent Script Files): a
+    /// relative path is made absolute against the working directory, so it opens the same file
+    /// after the working directory changes. `None` when the path can't be made absolute (the
+    /// working directory can't be read); the script is then not added to the list.
+    fn full_path(&self, path: &str) -> Option<String> {
+        std::path::absolute(path).ok().map(|p| p.to_string_lossy().into_owned())
+    }
+}
+
+/// Native filesystem.
+pub struct FsServices;
+
+impl Services for FsServices {
+    fn read_file(&self, path: &str) -> std::io::Result<Vec<u8>> {
+        std::fs::read(path)
+    }
+    fn write_file(&self, path: &str, data: &[u8]) -> std::io::Result<()> {
+        config::atomic_write(std::path::Path::new(path), data)
+    }
+}
+
+/// Imports media files into the project (implemented by the media layer).
+pub trait Importer: Send + Sync {
+    /// Probe one file and return footage metadata. Image sequences are the engine's
+    /// ([`sequence`]): it groups numbered stills and probes their first file here.
+    fn probe(&self, path: &str) -> std::result::Result<effectcraft_project::Footage, String>;
+    /// A footage file's bytes are now at `path` (extracted from a template): hosts whose media
+    /// layer reads from memory (the browser) register them; file-based ones need nothing.
+    fn register(&self, _path: &str, _data: &[u8]) {}
+    /// An image sequence's other frames (its first was probed) are footage now: hosts whose
+    /// media layer reads from memory (the browser) register them; file-based ones need nothing.
+    fn add_frames(&self, _paths: &[String]) {}
+}
diff --git a/crates/engine/src/session.rs b/crates/engine/src/session.rs
new file mode 100644
index 000000000..18b0ff4cf
--- /dev/null
+++ b/crates/engine/src/session.rs
@@ -0,0 +1,13 @@
+use super::doc_state::{CompSelection, EditorState};
+use super::error::{EngineError, Result};
+use super::event::Event;
+use super::{
+    Arc, Comp, History, Image, ItemId, LayerId, Project, RenderOpts, Renderer, Session, ThumbnailJob, Tick, Value, camera_track, commands, guard, roto, warp,
+};
+
+mod comps;
+mod dispatch;
+mod edit;
+mod render;
+
+pub use edit::upgrade_effects;
diff --git a/crates/engine/src/session/comps.rs b/crates/engine/src/session/comps.rs
new file mode 100644
index 000000000..ed3810e79
--- /dev/null
+++ b/crates/engine/src/session/comps.rs
@@ -0,0 +1,283 @@
+use super::{Comp, CompSelection, Event, ItemId, LayerId, Result, Session, Tick, Value, commands};
+
+/// `t` as a current time of `comp`: a frame within its duration.
+fn comp_frame_at(comp: &Comp, t: Tick) -> Tick {
+    comp.frame_rate.snap_nearest(t.min(comp.duration - comp.frame_duration()).max(Tick::ZERO))
+}
+
+impl Session {
+    /// Keep selections valid after the project was replaced by another state (undo, redo, a
+    /// history jump, a rollback): the same layer id can name a different document, so the
+    /// on-canvas editor gets a fresh IME epoch only when its own document changed.
+    ///
+    /// Normally `before` is [`commands::text_edit::active_editor_snapshot`] taken from the
+    /// state this call is about to replace. Atomic batch rollback is the exception: it has
+    /// already restored the pre-batch state and passes the snapshot of the failing intermediate
+    /// state, so a transient restart or component switch inside the batch still rejects reviving
+    /// the old composition. A restored state that still has the same composition, layer and
+    /// editor session and shows byte/style-equivalent text (an opacity or other property undo)
+    /// keeps the editor's owner and selection; a different document, comp, layer or session clamps the
+    /// selection and starts a new epoch. A closed editor stays closed, and a fallback comp's
+    /// matching layer id never inherits the old comp's session. `None` means no editor was open
+    /// when the snapshot was taken; if one is open after the replacement it is treated as an
+    /// unverified document replacement, so it never inherits an old composition.
+    pub fn sanitize_after_replacement(&mut self, before: Option<&commands::text_edit::EditorSnapshot>) {
+        self.sanitize_state();
+        commands::text_edit::after_replacement(self, before);
+    }
+
+    /// Drop selections that no longer exist. Each comp keeps its own selection (#1001); a layer id
+    /// counts only inside the comp that owns it, so the active comp never sees another comp's layers.
+    pub fn sanitize_state(&mut self) {
+        let p = self.project.clone();
+        self.state.open_comps.retain(|c| p.comp(*c).is_some());
+        self.state.comp_selections.retain(|cid, sel| {
+            let Some(c) = p.comp(*cid) else { return false };
+            let ids: Vec<LayerId> = c.layers.iter().map(|l| l.id).collect();
+            sel.layers.retain(|l| ids.contains(l));
+            sel.props.retain(|(l, _)| ids.contains(l));
+            sel.keys.retain(|k| ids.contains(&k.layer));
+            sel.vertices.retain(|v| ids.contains(&v.layer));
+            !sel.is_empty()
+        });
+        if self.state.active_comp.is_some_and(|c| p.comp(c).is_none()) {
+            self.clear_live_selection();
+            // A matching layer id in the fallback comp is not the document being edited.
+            self.state.text_edit = None;
+            self.state.active_comp = self.state.open_comps.first().copied();
+            if let Some(id) = self.state.active_comp {
+                self.recall_selection(id);
+            }
+        }
+        if let Some(c) = self.active_comp() {
+            let ids: Vec<LayerId> = c.layers.iter().map(|l| l.id).collect();
+            self.state.selected_layers.retain(|l| ids.contains(l));
+            self.state.selected_props.retain(|(l, _)| ids.contains(l));
+            self.state.selected_keys.retain(|k| ids.contains(&k.layer));
+            self.state.selected_vertices.retain(|v| ids.contains(&v.layer));
+        }
+        if let Some((l, t)) = self.state.current_track
+            && self.active_comp().and_then(|c| c.layer(l)).and_then(|l| l.tracker(t)).is_none()
+        {
+            self.state.current_track = None;
+        }
+        self.state.project_selection.retain(|i| p.item(*i).is_some());
+        commands::text_edit::sanitize(self);
+    }
+
+    pub fn active_comp(&self) -> Option<&Comp> {
+        self.project.comp(self.state.active_comp?)
+    }
+
+    /// [`Session::active_comp`] as a shared snapshot (an `Arc` clone, not a deep copy).
+    pub fn active_comp_arc(&self) -> Option<std::sync::Arc<Comp>> {
+        self.project.comp_arc(self.state.active_comp?)
+    }
+
+    pub fn active_comp_id(&self) -> Option<ItemId> {
+        self.state.active_comp.filter(|c| self.project.comp(*c).is_some())
+    }
+
+    /// Current time of a comp.
+    pub fn time_of(&self, comp: ItemId) -> Tick {
+        self.state.times.get(&comp).copied().unwrap_or(Tick::ZERO)
+    }
+
+    /// Current time of the active comp.
+    pub fn time(&self) -> Tick {
+        self.state.active_comp.and_then(|c| self.state.times.get(&c).copied()).unwrap_or(Tick::ZERO)
+    }
+
+    /// Move the active comp's current time.
+    ///
+    /// Time is an external boundary for the on-canvas text editor too: an animated Source Text
+    /// can show a different document at another time. The document is snapshotted only while an
+    /// editor is open, so playback with no text editor does no text copying.
+    pub fn set_time(&mut self, t: Tick) {
+        if let Some(c) = self.state.active_comp {
+            let t = self.project.comp(c).map_or(t, |comp| comp_frame_at(comp, t));
+            let edited = commands::text_edit::active_editor_snapshot(self);
+            self.state.times.insert(c, t);
+            if self.prefs.general.sync_time_related_items {
+                // Direct call: this `set_time` owns the editor snapshot for both time changes,
+                // so a synced move does not take a second snapshot or start a second epoch.
+                self.sync_related_times_inner(c, t);
+            }
+            commands::text_edit::after_external_change(self, edited.as_ref());
+        }
+    }
+
+    /// Settings ▸ General ▸ Synchronize Time of All Related Items: moving the current time of
+    /// `comp` moves the current time of the comps nested in it (through their precomp layers'
+    /// timing) and of the comps it is nested in, so every related viewer shows the same moment.
+    pub fn sync_related_times(&mut self, comp: ItemId, t: Tick) {
+        // Moving a related comp can move the active one, so the editor's document is checked
+        // here too; the snapshot is skipped entirely when no text editor is open.
+        let edited = commands::text_edit::active_editor_snapshot(self);
+        self.sync_related_times_inner(comp, t);
+        commands::text_edit::after_external_change(self, edited.as_ref());
+    }
+
+    /// Sets the time of every comp related to `comp` through precomp layers: down into the comps
+    /// it nests (through each layer's timing) and up into the comps nesting it. A seen-set keeps
+    /// cycles and diamonds finite; each found time is clamped to its comp's last frame, snapped to
+    /// the nearest frame and stored in `state.times`. The caller owns the text-editor boundary.
+    fn sync_related_times_inner(&mut self, comp: ItemId, t: Tick) {
+        let mut seen = std::collections::BTreeSet::from([comp]);
+        let mut todo = vec![(comp, t)];
+        let mut found = vec![];
+        while let Some((cid, ct)) = todo.pop() {
+            if cid != comp {
+                found.push((cid, ct));
+            }
+            let Some(c) = self.project.comp(cid) else { continue };
+            // Down: the comps this one nests.
+            for l in &c.layers {
+                if let effectcraft_project::LayerSource::Comp { item } = &l.source
+                    && seen.insert(*item)
+                {
+                    todo.push((*item, l.layer_time(ct)));
+                }
+            }
+            // Up: the comps nesting this one.
+            for iid in self.project.items.keys() {
+                if let Some(pc) = self.project.comp(*iid)
+                    && let Some(l) = pc.layers.iter().find(|l| matches!(&l.source, effectcraft_project::LayerSource::Comp { item } if *item == cid))
+                    && seen.insert(*iid)
+                {
+                    todo.push((*iid, l.comp_time(ct)));
+                }
+            }
+        }
+        for (cid, ct) in found {
+            if let Some(c) = self.project.comp(cid) {
+                let ct = c.frame_rate.snap_nearest(ct.clamp(Tick::ZERO, (c.duration - c.frame_duration()).max(Tick::ZERO)));
+                self.state.times.insert(cid, ct);
+            }
+        }
+    }
+
+    /// Make `id` the active comp, parking the previous comp's selection and restoring this one's.
+    pub fn activate_comp(&mut self, id: ItemId) {
+        if self.project.comp(id).is_none() || self.state.active_comp == Some(id) {
+            return;
+        }
+        self.remember_selection();
+        self.state.active_comp = Some(id);
+        self.recall_selection(id);
+        self.state.current_track = None;
+        // A text-edit session belongs to the comp that owned it. Switching comps ends it; even
+        // a same-numbered layer in the new comp must not inherit the old IME composition.
+        self.state.text_edit = None;
+    }
+
+    /// Leave no comp active, keeping the one that was active in [`EditorState::comp_selections`].
+    pub fn activate_comp_none(&mut self) {
+        self.remember_selection();
+        self.state.active_comp = None;
+        self.clear_live_selection();
+        self.state.current_track = None;
+        self.state.text_edit = None;
+    }
+
+    fn remember_selection(&mut self) {
+        let Some(id) = self.state.active_comp else { return };
+        let sel = CompSelection {
+            layers: self.state.selected_layers.clone(),
+            props: self.state.selected_props.clone(),
+            keys: self.state.selected_keys.clone(),
+            vertices: self.state.selected_vertices.clone(),
+        };
+        if sel.is_empty() {
+            self.state.comp_selections.remove(&id);
+        } else {
+            self.state.comp_selections.insert(id, sel);
+        }
+    }
+
+    fn recall_selection(&mut self, id: ItemId) {
+        match self.state.comp_selections.remove(&id) {
+            Some(sel) => {
+                self.state.selected_layers = sel.layers;
+                self.state.selected_props = sel.props;
+                self.state.selected_keys = sel.keys;
+                self.state.selected_vertices = sel.vertices;
+            }
+            None => self.clear_live_selection(),
+        }
+    }
+
+    fn clear_live_selection(&mut self) {
+        self.state.selected_layers.clear();
+        self.state.selected_props.clear();
+        self.state.selected_keys.clear();
+        self.state.selected_vertices.clear();
+    }
+
+    /// Open a comp in the viewer/timeline and make it active.
+    pub fn open_comp(&mut self, id: ItemId) {
+        if self.project.comp(id).is_none() {
+            return;
+        }
+        if !self.state.open_comps.contains(&id) {
+            self.state.open_comps.push(id);
+        }
+        if self.state.active_comp != Some(id) {
+            let previous = self.state.active_comp;
+            self.state.recent_comps.retain(|c| *c != id && Some(*c) != previous);
+            if let Some(previous) = previous {
+                self.state.recent_comps.insert(0, previous);
+                self.state.recent_comps.truncate(32);
+            }
+        }
+        self.activate_comp(id);
+        self.events.push(Event::OpenComp(id));
+    }
+
+    /// The open compositions and their current times, as a project file records them
+    /// ([`effectcraft_project::SavedView`]).
+    pub fn saved_view(&self) -> effectcraft_project::SavedView {
+        let comp_times = self.state.times.iter().filter(|(id, _)| self.project.comp(**id).is_some()).map(|(id, t)| (*id, *t)).collect();
+        effectcraft_project::SavedView { active_comp: self.state.active_comp, open_comps: self.state.open_comps.clone(), comp_times }
+    }
+
+    /// Reopen the compositions a project file was saved with (#748), each at its saved current
+    /// time (#1714). Ids that no longer name a comp are skipped; with none left the project stays
+    /// on the comp [`Session::replace_project`] opened (its first), as files from before the view
+    /// was saved do.
+    pub fn restore_view(&mut self, view: &effectcraft_project::SavedView) {
+        for (id, t) in &view.comp_times {
+            if let Some(comp) = self.project.comp(*id) {
+                let t = comp_frame_at(comp, *t);
+                self.state.times.insert(*id, t);
+            }
+        }
+        let mut open: Vec<ItemId> = Vec::new();
+        for id in view.open_comps.iter().copied().filter(|id| self.project.comp(*id).is_some()) {
+            if !open.contains(&id) {
+                open.push(id);
+            }
+        }
+        let Some(active) = view.active_comp.filter(|id| self.project.comp(*id).is_some()).or_else(|| open.first().copied()) else { return };
+        self.state.open_comps = open;
+        self.open_comp(active);
+    }
+
+    /// The 3D view camera of a comp's viewer (None = the active camera).
+    pub fn view_camera(&self, comp: ItemId) -> Option<effectcraft_render::three_d::CameraState> {
+        let c = self.project.comp(comp)?;
+        if !c.has_3d() {
+            return None;
+        }
+        self.state.views3d.get(&comp)?.override_camera(c.width as f64, c.height as f64)
+    }
+
+    /// Resolve a comp reference (item id number or name; `None`/null = the active comp).
+    pub fn resolve_comp(&self, comp: Option<&Value>) -> Result<ItemId> {
+        let p = match comp {
+            Some(v) if !v.is_null() => serde_json::json!({ "comp": v }),
+            _ => serde_json::json!({}),
+        };
+        commands::comp_id(self, &p)
+    }
+}
diff --git a/crates/engine/src/session/dispatch.rs b/crates/engine/src/session/dispatch.rs
new file mode 100644
index 000000000..36c7f0a51
--- /dev/null
+++ b/crates/engine/src/session/dispatch.rs
@@ -0,0 +1,70 @@
+use super::{EngineError, Event, Result, Session, Value, commands, guard};
+
+impl Session {
+    pub fn new() -> Session {
+        Session::default()
+    }
+
+    /// Run a command by id.
+    pub fn execute(&mut self, id: &str, params: Value) -> Result<Value> {
+        let spec = commands::find(id).ok_or_else(|| EngineError::UnknownCommand(id.to_string()))?;
+        if let Err(why) = (spec.enabled)(self) {
+            // Explicit targets (agents, scripts) don't need a UI selection.
+            let explicit = (["layer", "layers", "prop", "keys"].iter().any(|k| params.get(k).is_some()) && commands::has_comp(self).is_ok())
+                || ["item", "items"].iter().any(|k| params.get(k).is_some())
+                // An explicit composition (the enablement looks at the active one).
+                || params.get("comp").is_some_and(|c| !c.is_null() && self.resolve_comp(Some(c)).is_ok());
+            if !explicit {
+                return Err(EngineError::Disabled(id.to_string(), why));
+            }
+        }
+        // Last-resort guard: a panicking command reports an error instead of crashing the app.
+        let r = guard::guarded(&format!("command `{id}`"), || (spec.run)(self, &params))?;
+        self.learn_observe(id, &params);
+        if spec.journal {
+            self.journal.push((id.to_string(), params));
+            if self.journal.len() > 10_000 {
+                self.journal.drain(..1000);
+            }
+        }
+        Ok(r)
+    }
+
+    /// [`Session::execute`] for agents and scripts (MCP, CLI, control channel): unknown top-level
+    /// parameters are rejected with the accepted keys instead of being silently ignored.
+    pub fn execute_checked(&mut self, id: &str, params: Value) -> Result<Value> {
+        let spec = commands::find(id).ok_or_else(|| EngineError::UnknownCommand(id.to_string()))?;
+        commands::check_params(spec, &params)?;
+        self.execute(id, params)
+    }
+
+    /// [`Session::execute`] for a command a script asked for (the JavaScript engine's
+    /// `app.run`, ScriptUI callbacks…). The command and everything it runs count as the script's:
+    /// it may not change the settings that limit scripts (Settings ▸ Scripting & Expressions ▸
+    /// Application Scripting), which only the user can, from the UI, CLI or control channel.
+    pub fn execute_for_script(&mut self, id: &str, params: Value) -> Result<Value> {
+        self.script_calls.0 = self.script_calls.0.saturating_add(1);
+        let r = self.execute(id, params);
+        self.script_calls.0 = self.script_calls.0.saturating_sub(1);
+        r
+    }
+
+    /// Whether the command running was issued by a script ([`Session::execute_for_script`]).
+    pub fn running_for_script(&self) -> bool {
+        self.script_calls.0 > 0
+    }
+
+    /// Whether `id` names a known command whose `enabled` predicate returns `Ok` for this session;
+    /// an unknown id or a predicate error reads as disabled.
+    pub fn is_enabled(&self, id: &str) -> bool {
+        commands::find(id).is_some_and(|c| (c.enabled)(self).is_ok())
+    }
+
+    pub fn toast(&mut self, msg: impl Into<String>) {
+        self.events.push(Event::Toast { message: msg.into(), error: false });
+    }
+
+    pub fn drain_events(&mut self) -> Vec<Event> {
+        std::mem::take(&mut self.events)
+    }
+}
diff --git a/crates/engine/src/session/edit.rs b/crates/engine/src/session/edit.rs
new file mode 100644
index 000000000..c2590abc3
--- /dev/null
+++ b/crates/engine/src/session/edit.rs
@@ -0,0 +1,314 @@
+use super::{Arc, EditorState, EngineError, Event, History, ItemId, Project, Result, Session, camera_track, commands, roto, warp};
+
+impl Session {
+    /// Apply an undoable edit. `merge`: consecutive edits with the same key fold into one step.
+    ///
+    /// Every edit is an external boundary for the on-canvas text editor: if it replaced the
+    /// document the editor is showing, the selection is clamped and the editor gets a fresh IME
+    /// epoch. The editor's own typing goes through `edit_text_doc`, which owns that
+    /// document and must not treat its own keystrokes as a replacement.
+    pub fn edit<T>(&mut self, label: &str, merge: Option<&str>, f: impl FnOnce(&mut Project, &mut EditorState) -> Result<T>) -> Result<T> {
+        let edited = commands::text_edit::active_editor_snapshot(self);
+        let out = self.edit_inner(label, merge, f)?;
+        commands::text_edit::after_external_change(self, edited.as_ref());
+        Ok(out)
+    }
+
+    /// [`Session::edit`] for the on-canvas editor's own text changes. Its document is the one
+    /// the editor owns, so a change here is typing, not a replacement behind the IME's back.
+    pub(crate) fn edit_text_doc<T>(&mut self, label: &str, merge: Option<&str>, f: impl FnOnce(&mut Project, &mut EditorState) -> Result<T>) -> Result<T> {
+        self.edit_inner(label, merge, f)
+    }
+
+    /// The shared body of [`Session::edit`] and [`Session::edit_text_doc`].
+    ///
+    /// Runs `f` on a clone of the project and editor state, then synchronizes derived data (global
+    /// light and Essential Graphics), queues invalidated Warp Stabilizer/camera-tracker work and
+    /// Roto Brush instances needing re-propagation in the `*_pending` lists. If the clone has the same
+    /// content the project and history are left as they were (only editor-state changes from `f`
+    /// are kept) and no revision is bumped; otherwise the previous project is recorded as an
+    /// undo step under `label`, unless it merges with the current merge key (then the redo branch
+    /// is dropped). An `Err` from `f` propagates with the session unchanged.
+    fn edit_inner<T>(&mut self, label: &str, merge: Option<&str>, f: impl FnOnce(&mut Project, &mut EditorState) -> Result<T>) -> Result<T> {
+        let before = self.project.clone();
+        let mut p = (*self.project).clone();
+        let mut st = self.state.clone();
+        let r = f(&mut p, &mut st)?;
+        // Layer styles: one Global Light per comp, whichever layer edited it.
+        effectcraft_project::styles::sync_global_light(&before, &mut p);
+        // Essential Properties of precomp layers follow their comps' Essential Graphics.
+        effectcraft_project::essential::sync_project(&before, &mut p);
+        // Warp Stabilizer analyses made from other frames are cleared (and queued again).
+        for w in warp::invalidate(&before, &mut p) {
+            if !self.warp_pending.contains(&w) {
+                self.warp_pending.push(w);
+            }
+        }
+        // So are 3D Camera Tracker tracks (and solves made with other settings).
+        for w in camera_track::invalidate(&before, &mut p) {
+            if !self.camera_pending.contains(&w) {
+                self.camera_pending.push(w);
+            }
+        }
+        // Roto Brush Input Keys follow the frames; edited instances propagate again.
+        for r in roto::sync(&before, &mut p) {
+            if !self.roto_pending.contains(&r) {
+                self.roto_pending.push(r);
+            }
+        }
+        // Nothing changed (a value set to what it already was): no undo step, not modified.
+        if p.same_content(&before) {
+            self.state = st;
+            return Ok(r);
+        }
+        let same = merge.is_some() && merge.map(str::to_string) == self.history.merge_key;
+        if !same {
+            // Undone steps aren't lost: they stay in the History panel as a branch.
+            let levels = self.prefs.general.undo_levels.max(1) as usize;
+            self.history.record(label, before, levels);
+        } else {
+            self.history.abandon_redo(&before);
+        }
+        self.history.merge_key = merge.map(str::to_string);
+        self.project = Arc::new(p);
+        self.state = st;
+        self.bump();
+        Ok(r)
+    }
+
+    /// Note a change to the on-canvas editor's committed text or session.
+    ///
+    /// Frontends compare this with [`commands::text_edit::ime_stamp_revision`]; an unrelated
+    /// project change must not advance it.
+    pub(crate) fn note_text_edit_change(&mut self) {
+        // Checked process-wide allocation: a stamp is never wrapped or reused. On exhaustion
+        // keep the previous value; an unavailable before/after pair then compares equal and
+        // earns no receipt instead of accepting a stale revision.
+        if let Some(revision) = commands::text_edit::next_ime_revision() {
+            self.ime_revision = self.ime_revision.max(revision);
+        }
+    }
+
+    pub fn bump(&mut self) {
+        self.revision += 1;
+        // A Cryptomatte probe is keyed by the revision: an older one never answers again.
+        self.drop_crypto_probe();
+        // Back at the saved state (undo, redo, a history jump or a rolled-back batch).
+        if Arc::ptr_eq(&self.project, &self.saved_project) {
+            self.saved_revision = self.revision;
+        }
+        self.refresh_disk_salt(false);
+        self.events.push(Event::ProjectChanged { revision: self.revision });
+    }
+
+    /// Salt the disk cache's layer keys with the project's footage files
+    /// ([`effectcraft_render::disk_cache::footage_salt`]). Taking it reads the size and time of
+    /// every file, every frame of an image sequence included, so it is taken again only when the
+    /// footage items changed, or with `force` (a project opened, footage reloaded, the disk cache
+    /// attached), not at every edit: with a few large sequences that cost each keystroke in a
+    /// text field over half a second (#1926).
+    pub fn refresh_disk_salt(&mut self, force: bool) -> Option<u64> {
+        use std::hash::{Hash, Hasher};
+        if self.disk_cache.is_none() {
+            self.disk_salt = None;
+            return None;
+        }
+        let mut h = std::collections::hash_map::DefaultHasher::new();
+        for (id, it) in &self.project.items {
+            if let effectcraft_project::ItemKind::Footage(f) = &it.kind {
+                id.hash(&mut h);
+                format!("{f:?}").hash(&mut h);
+            }
+        }
+        let footage = h.finish();
+        if let Some((seen, salt)) = self.disk_salt
+            && seen == footage
+            && !force
+        {
+            return Some(salt);
+        }
+        let salt = effectcraft_render::disk_cache::footage_salt(&self.project);
+        self.disk_salt = Some((footage, salt));
+        self.layer_cache.set_disk_salt(salt);
+        Some(salt)
+    }
+
+    /// Set a comp's Resolution. As in After Effects it is saved with the project (which becomes
+    /// modified) but is no undo step, and it changes no pixels: the comp's cached frames stay
+    /// valid ([`effectcraft_project::Comp::same_pixels`]).
+    pub fn set_resolution(&mut self, comp: ItemId, r: effectcraft_project::Resolution) -> Result<()> {
+        if self.project.comp(comp).ok_or(EngineError::NoComp)?.resolution == r {
+            return Ok(());
+        }
+        Arc::make_mut(&mut self.project).comp_mut(comp).ok_or(EngineError::NoComp)?.resolution = r;
+        self.bump();
+        Ok(())
+    }
+
+    /// Keep what lives outside the undo history (each comp's Resolution) as it is in `from`, the
+    /// project before undo, redo or a history jump restored another state.
+    pub(crate) fn keep_view_settings(&mut self, from: &Project) {
+        let keep: Vec<(ItemId, effectcraft_project::Resolution)> =
+            self.project.comps().filter_map(|(id, c)| from.comp(*id).map(|f| (*id, f.resolution)).filter(|(_, r)| *r != c.resolution)).collect();
+        if keep.is_empty() {
+            return;
+        }
+        let p = Arc::make_mut(&mut self.project);
+        for (id, r) in keep {
+            if let Some(c) = p.comp_mut(id) {
+                c.resolution = r;
+            }
+        }
+    }
+
+    /// Undoes one step: the current project goes onto the redo stack, per-comp Resolution is kept
+    /// as it was, the merge key is cleared, selections are sanitized for the replaced state (the
+    /// on-canvas editor gets a new IME epoch only when its own document changed) and the session is
+    /// bumped. Returns `false`, changing nothing, when there is nothing to undo.
+    pub fn undo(&mut self) -> bool {
+        let Some((label, p)) = self.history.undo.pop() else { return false };
+        let edited = commands::text_edit::active_editor_snapshot(self);
+        let probe = commands::kept_crypto_probe(self);
+        let cur = std::mem::replace(&mut self.project, p);
+        self.keep_view_settings(&cur);
+        self.history.merge_key = None;
+        self.sanitize_after_replacement(edited.as_ref());
+        self.bump();
+        commands::keep_crypto_probe(self, probe, &cur);
+        self.history.redo.push((label, cur));
+        true
+    }
+
+    /// Redoes one step: the current project goes back onto the undo stack, per-comp Resolution is
+    /// kept, the merge key is cleared, selections are sanitized for the replaced state (a changed
+    /// text document starts a new IME epoch) and the session is bumped. Returns `false`, changing
+    /// nothing, when there is nothing to redo.
+    pub fn redo(&mut self) -> bool {
+        let Some((label, p)) = self.history.redo.pop() else { return false };
+        let edited = commands::text_edit::active_editor_snapshot(self);
+        let probe = commands::kept_crypto_probe(self);
+        let cur = std::mem::replace(&mut self.project, p);
+        self.keep_view_settings(&cur);
+        self.history.merge_key = None;
+        self.sanitize_after_replacement(edited.as_ref());
+        self.bump();
+        commands::keep_crypto_probe(self, probe, &cur);
+        self.history.undo.push((label, cur));
+        true
+    }
+
+    pub fn is_dirty(&self) -> bool {
+        self.revision != self.saved_revision
+    }
+
+    /// The project as it is now is the saved one (after opening or saving it).
+    pub fn mark_saved(&mut self) {
+        self.saved_project = self.project.clone();
+        self.saved_revision = self.revision;
+    }
+
+    /// The project has changes its file doesn't (a session restored with unsaved changes): it
+    /// stays modified until it is saved, whatever is undone.
+    pub fn mark_unsaved(&mut self) {
+        self.saved_project = Arc::new(Project::default());
+        self.bump();
+    }
+
+    /// Replace the whole project (open/new), resetting history and state.
+    pub fn replace_project(&mut self, mut p: Project, path: Option<String>) {
+        if self.stop_render()
+            && let Some(mut job) = self.render_job.take()
+        {
+            // Let the worker notice the cancel; its updates refer to the old project.
+            job.wait();
+        }
+        self.render_job = None;
+        self.stored_paths = Default::default();
+        self.stop_track();
+        self.track_job = None;
+        self.stop_mask_track();
+        self.mask_job = None;
+        self.stop_warp();
+        self.warp_job = None;
+        self.warp_pending.clear();
+        self.stop_camera();
+        self.camera_job = None;
+        self.camera_pending.clear();
+        self.stop_roto();
+        self.roto_job = None;
+        self.roto_pending.clear();
+        self.drop_tasks();
+        self.script_ui.project_epoch = self.script_ui.project_epoch.wrapping_add(1);
+        p.fix_next_id();
+        upgrade_effects(&mut p);
+        // The media layer keys decoded frames by path: files of the new project may have changed
+        // since an earlier project decoded them (#1070).
+        for it in p.items.values() {
+            if let effectcraft_project::ItemKind::Footage(f) = &it.kind {
+                self.forget_decoded(f);
+            }
+        }
+        self.layer_cache.clear();
+        self.project = Arc::new(p);
+        // Its files may have changed since they were last stamped.
+        self.disk_salt = None;
+        self.history = History::default();
+        self.state = EditorState { snapping: true, view_layout: 1, ..Default::default() };
+        self.path = path;
+        self.bump();
+        self.mark_saved();
+        let first = self.project.comps().next().map(|(id, _)| *id);
+        if let Some(c) = first {
+            self.open_comp(c);
+        }
+    }
+}
+
+/// Bring effect instances saved by earlier versions up to date with the effect registry
+/// (renamed / regrouped / added parameters, reordered popups; see
+/// [`effectcraft_effects::migrate`]), and a project from before
+/// [`effectcraft_project::SCHEMA_EFFECT_SPACE`] into effect space
+/// ([`effectcraft_effects::migrate::to_effect_space`]). Shape path operations get the
+/// properties added since ([`effectcraft_project::build::upgrade_shape_contents`]). Stamps the
+/// current schema.
+pub fn upgrade_effects(p: &mut Project) {
+    let to_effect_space = p.schema < effectcraft_project::SCHEMA_EFFECT_SPACE;
+    // Effect bounds per layer: (size, top-left in layer coordinates).
+    let mut bounds = std::collections::HashMap::new();
+    for (cid, c) in p.comps() {
+        for l in &c.layers {
+            bounds.insert((*cid, l.id), effectcraft_render::effect_bounds(p, c, l));
+        }
+    }
+    let mut next = p.next_id;
+    for (cid, it) in p.items.iter_mut() {
+        let effectcraft_project::ItemKind::Comp(c) = &mut it.kind else { continue };
+        for l in &mut std::sync::Arc::make_mut(c).layers {
+            let (size, origin) = bounds.get(&(*cid, l.id)).copied().unwrap_or(([100.0, 100.0], [0.0; 2]));
+            // Effect space starts at the bounds' top-left: positions move by minus that corner.
+            // Adjustment layers run their effects on the comp below as it is: nothing moves.
+            let shift = |o: [f64; 2]| [-o[0], -o[1]];
+            let d = if l.switches.adjustment { [0.0; 2] } else { shift(origin) };
+            let clone_d = |src: Option<u64>| match src {
+                Some(id) => bounds.get(&(*cid, effectcraft_project::LayerId(id))).map_or([0.0; 2], |b| shift(b.1)),
+                None => d,
+            };
+            if let Some(contents) = l.props.sub_mut("contents") {
+                effectcraft_project::build::upgrade_shape_contents(&mut effectcraft_project::build::Ids(&mut next), contents);
+            }
+            let Some(fx) = l.props.sub_mut("effects") else { continue };
+            for n in &mut fx.children {
+                let effectcraft_project::Node::Group(g) = n else { continue };
+                let effectcraft_project::GroupKind::Effect { effect } = &g.kind else { continue };
+                if let Some(spec) = effectcraft_effects::find(effect) {
+                    effectcraft_effects::migrate::upgrade_instance(spec, g, &mut effectcraft_project::build::Ids(&mut next), size);
+                    if to_effect_space {
+                        effectcraft_effects::migrate::to_effect_space(spec, g, size, d, &clone_d);
+                    }
+                }
+            }
+        }
+    }
+    p.next_id = next;
+    p.schema = effectcraft_project::SCHEMA_VERSION;
+}
diff --git a/crates/engine/src/session/render.rs b/crates/engine/src/session/render.rs
new file mode 100644
index 000000000..6f2d273ad
--- /dev/null
+++ b/crates/engine/src/session/render.rs
@@ -0,0 +1,140 @@
+use super::{EngineError, Image, ItemId, RenderOpts, Renderer, Result, Session, ThumbnailJob, Tick, Value, commands};
+
+impl Session {
+    /// Render a comp frame with the session's footage + expression hosts.
+    pub fn render(&self, comp: ItemId, t: Tick, opts: RenderOpts) -> Image {
+        self.renderer(opts).comp_frame(comp, t)
+    }
+
+    /// The renderer [`Session::render`] uses: the session's footage, expressions, layer cache and
+    /// accelerator, and the render prefs (nested switches, draft shadows) over `opts`.
+    pub fn renderer(&self, opts: RenderOpts) -> Renderer<'_> {
+        let mut r = Renderer::new(&self.project, self.footage.as_ref(), self.render_opts(opts));
+        r.expr = self.expr.as_deref();
+        r.cache = Some(&self.layer_cache);
+        r.accel = self.accel.as_deref();
+        r
+    }
+
+    /// `opts` with the render prefs (nested switches, draft shadows), as [`Session::renderer`].
+    pub fn render_opts(&self, opts: RenderOpts) -> RenderOpts {
+        RenderOpts { nested_switches: self.prefs.general.switches_affect_nested_comps, draft_shadows: self.prefs.three_d.realtime_shadows, ..opts }
+    }
+
+    /// Whether `effect.cryptomatteAt` with params `p` answers from the kept probe (a few array
+    /// reads; `probeOnly` queries answer `pending` until then). Changes nothing: ask it every
+    /// frame, and start [`Session::crypto_probe_job`] only when a build will actually run.
+    pub fn crypto_probe_ready(&self, p: &Value) -> Result<bool> {
+        commands::crypto_probe_ready(self, p)
+    }
+
+    /// For the Cryptomatte eyedropper: `None` when `effect.cryptomatteAt` with params `p` answers
+    /// from the kept probe, else a job that builds that probe (it may render a precomp's ID pass)
+    /// off the UI thread, for the next query to use. Asking for a job supersedes a build in
+    /// flight for another probe (it then stores nothing): ask only to run it.
+    pub fn crypto_probe_job(&self, p: &Value) -> Result<Option<commands::CryptoProbeJob>> {
+        commands::crypto_probe_job(self, p)
+    }
+
+    /// Let go of the kept Cryptomatte probe (and its aux channels), and cancel a build in
+    /// flight: the eyedropper was disarmed. Edits, footage changes and Open / New do it too.
+    pub fn drop_crypto_probe(&self) {
+        if let Ok(mut slot) = self.crypto_probe.lock() {
+            slot.clear();
+        }
+    }
+
+    /// Whether a Cryptomatte probe is kept, and how many were built so far (for tests).
+    #[doc(hidden)]
+    pub fn crypto_probe_stats(&self) -> (bool, u64) {
+        self.crypto_probe.lock().map_or((false, 0), |s| (s.kept(), s.builds().1))
+    }
+
+    /// How many probe jobs ran so far, built or cancelled before they began (for tests: each
+    /// is a thread in the eyedropper).
+    #[doc(hidden)]
+    pub fn crypto_probe_jobs(&self) -> u64 {
+        self.crypto_probe.lock().map_or(0, |s| s.builds().0)
+    }
+
+    /// Render a comp frame (comp time `t`) as opaque 8-bit RGBA over the comp background, scaled
+    /// so the longest side is at most `max_side` pixels (0 = full size). Returns (width, height, rgba).
+    pub fn render_rgba8(&self, comp: ItemId, t: Tick, max_side: u32) -> Result<(u32, u32, Vec<u8>)> {
+        let c = self.project.comp(comp).ok_or(EngineError::NoComp)?;
+        let long = c.width.max(c.height).max(1) as f64;
+        let scale = if max_side == 0 { 1.0 } else { (max_side as f64 / long).min(1.0) };
+        let img = self.render(comp, t, RenderOpts { scale, backend: effectcraft_render::Backend::Auto, ..Default::default() });
+        Ok((img.width, img.height, img.to_rgba8_over(c.background)))
+    }
+
+    /// A Project panel thumbnail of an item (a comp at `t`, footage at its first frame), longest
+    /// side at most `max_side`, as a job that owns everything it reads: frontends run it off the
+    /// UI thread (a big comp takes far longer than a frame). `None` for items without pixels.
+    pub fn thumbnail_job(&self, item: ItemId, t: Tick, max_side: u32) -> Option<ThumbnailJob> {
+        let it = self.project.item(item)?;
+        let footage = self.footage.clone();
+        match &it.kind {
+            effectcraft_project::ItemKind::Comp(c) => {
+                let (project, expr, cache) = (self.project.clone(), self.expr.clone(), self.layer_cache.clone());
+                let long = c.width.max(c.height).max(1) as f64;
+                let scale = if max_side == 0 { 1.0 } else { (max_side as f64 / long).min(1.0) };
+                let opts = RenderOpts {
+                    scale,
+                    nested_switches: self.prefs.general.switches_affect_nested_comps,
+                    draft_shadows: self.prefs.three_d.realtime_shadows,
+                    ..Default::default()
+                };
+                let bg = c.background;
+                Some(Box::new(move || {
+                    let mut r = Renderer::new(&project, footage.as_ref(), opts);
+                    r.expr = expr.as_deref();
+                    r.cache = Some(&cache);
+                    let img = r.comp_frame(item, t);
+                    Some((img.width, img.height, img.to_rgba8_over(bg)))
+                }))
+            }
+            effectcraft_project::ItemKind::Footage(f) if f.has_video => {
+                let f = f.clone();
+                Some(Box::new(move || {
+                    let img = footage.frame(item, &f, Tick(0))?;
+                    // Point-sample down to at most `max_side` on the long side.
+                    let step = (img.width.max(img.height) as f32 / max_side.max(1) as f32).ceil().max(1.0) as u32;
+                    let (w, h) = (img.width.div_ceil(step), img.height.div_ceil(step));
+                    let full = img.to_rgba8();
+                    let mut px = Vec::with_capacity((w * h * 4) as usize);
+                    for y in 0..h {
+                        for x in 0..w {
+                            let i = (((y * step) * img.width + x * step) * 4) as usize;
+                            px.extend_from_slice(&full[i..i + 4]);
+                        }
+                    }
+                    Some((w, h, px))
+                }))
+            }
+            _ => None,
+        }
+    }
+
+    /// [`Session::render_rgba8`], or with `transparent` the frame's own straight alpha (what a
+    /// render with RGB + Alpha channels writes) instead of compositing over the background.
+    pub fn render_rgba8_alpha(&self, comp: ItemId, t: Tick, max_side: u32, transparent: bool) -> Result<(u32, u32, Vec<u8>)> {
+        if !transparent {
+            return self.render_rgba8(comp, t, max_side);
+        }
+        let c = self.project.comp(comp).ok_or(EngineError::NoComp)?;
+        let long = c.width.max(c.height).max(1) as f64;
+        let scale = if max_side == 0 { 1.0 } else { (max_side as f64 / long).min(1.0) };
+        let img = self.render(comp, t, RenderOpts { scale, backend: effectcraft_render::Backend::Auto, ..Default::default() });
+        Ok((img.width, img.height, img.to_rgba8()))
+    }
+
+    /// Make the media layer and the layer cache let go of what they decoded from `footage`'s
+    /// files (it keys frames by path, so an overwritten file would keep showing its old pixels).
+    pub(crate) fn forget_decoded(&self, footage: &effectcraft_project::Footage) {
+        for p in std::iter::once(&footage.path).chain(&footage.sequence) {
+            self.footage.forget(p);
+        }
+        self.layer_cache.clear();
+        self.drop_crypto_probe();
+    }
+}
diff --git a/crates/engine/src/settings.rs b/crates/engine/src/settings.rs
new file mode 100644
index 000000000..5981d4591
--- /dev/null
+++ b/crates/engine/src/settings.rs
@@ -0,0 +1,5 @@
+pub mod autosave;
+pub mod config;
+pub mod prefs;
+pub(super) mod session_settings;
+pub mod shortcuts;
diff --git a/crates/engine/src/autosave.rs b/crates/engine/src/settings/autosave.rs
similarity index 100%
rename from crates/engine/src/autosave.rs
rename to crates/engine/src/settings/autosave.rs
diff --git a/crates/engine/src/config.rs b/crates/engine/src/settings/config.rs
similarity index 100%
rename from crates/engine/src/config.rs
rename to crates/engine/src/settings/config.rs
diff --git a/crates/engine/src/settings/prefs.rs b/crates/engine/src/settings/prefs.rs
new file mode 100644
index 000000000..d2db7cd55
--- /dev/null
+++ b/crates/engine/src/settings/prefs.rs
@@ -0,0 +1,132 @@
+//! Settings (After Effects' Preferences): a versioned serde model, addressed by dotted keys
+//! (`general.undoLevels`, `autoSave.intervalMinutes`, `labels.3.name`), plus the page schema the
+//! Settings dialog and agents (`prefs.pages`) are built from.
+//!
+//! Settings are stored as JSON (`prefs.json`) through the session's [`crate::config::ConfigStore`].
+//! Loading is forgiving: missing keys take their defaults, unknown keys (written by a newer
+//! version) are kept and written back, and older layouts are migrated ([`migrate`]).
+//!
+//! Every setting in [`pages`] says whether it already changes behaviour (`live`). Settings that
+//! don't yet are still shown (After Effects parity of the dialog) and are listed in
+//! `docs/preferences.md`; a test keeps that list in step with the schema.
+
+use std::collections::BTreeMap;
+
+use effectcraft_color::Label;
+use effectcraft_time::Tick;
+use serde::{Deserialize, Serialize};
+use serde_json::{Map, Value, json};
+
+mod choices;
+mod dialog;
+mod document;
+mod queries;
+mod recent;
+mod sections;
+
+pub use choices::{APPEARANCE_MODES, DARK_THEMES, LANGUAGES, LIGHT_THEMES, THEMES, WINDOW_GRAPHICS, theme_family};
+pub use dialog::{Item, Kind, Page, pages, pages_json, todo_keys};
+pub use document::{migrate, page_id, section_key};
+pub use queries::{CacheBudgets, WEB_LAYER_CACHE, WEB_MEDIA_CACHE, mask_color};
+pub use recent::{MAX_RECENT_SCRIPTS, RecentScript};
+pub use sections::{
+    Appearance, Audio, AutoSave, CompPreset, CompositionPrefs, Disk, Export, FacePrefs, General, Grids, Import, LabelPref, Memory, Previews, ProjectPrefs,
+    RotoPrefs, Scripting, Startup, ThreeD, TypePrefs, Video,
+};
+use sections::{Extra, default_labels, lenient_comp_presets};
+
+/// Current settings layout version.
+pub const PREFS_VERSION: u32 = 3;
+/// Settings file name in the config store.
+pub const PREFS_FILE: &str = "prefs.json";
+
+/// All settings.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[serde(default, rename_all = "camelCase")]
+pub struct Prefs {
+    pub version: u32,
+    pub general: General,
+    pub startup: Startup,
+    pub project: ProjectPrefs,
+    pub auto_save: AutoSave,
+    pub composition: CompositionPrefs,
+    pub previews: Previews,
+    pub appearance: Appearance,
+    pub grids: Grids,
+    /// The 16 labels (Red … Dark Green), in order.
+    pub labels: Vec<LabelPref>,
+    #[serde(rename = "type")]
+    pub type_: TypePrefs,
+    pub import: Import,
+    pub export: Export,
+    pub audio: Audio,
+    pub disk: Disk,
+    pub memory: Memory,
+    pub video: Video,
+    #[serde(rename = "threeD")]
+    pub three_d: ThreeD,
+    pub scripting: Scripting,
+    pub roto: RotoPrefs,
+    pub face: FacePrefs,
+    /// File ▸ Open Recent, newest first.
+    pub recent_projects: Vec<String>,
+    /// File ▸ Import Recent Footage, newest first.
+    pub recent_footage: Vec<String>,
+    /// Animation ▸ Recent Animation Presets (`.ecpreset` paths or built-in preset ids), newest
+    /// first.
+    pub recent_presets: Vec<String>,
+    /// File ▸ Scripts ▸ Recent Script Files, newest first, at most [`MAX_RECENT_SCRIPTS`].
+    pub recent_scripts: Vec<RecentScript>,
+    /// Character panel: recently used font families, newest first.
+    pub recent_fonts: Vec<String>,
+    /// Effects & Presets: the starred effects' ids, in the order starred.
+    pub effects_favorites: Vec<String>,
+    /// Preview panel: every shortcut's options.
+    pub preview: crate::preview::PreviewSettings,
+    /// View ▸ Simulate Output ▸ My Custom RGB.
+    pub custom_rgb: crate::viewer::CustomRgb,
+    /// Composition Settings presets the user saved, in the order saved.
+    #[serde(deserialize_with = "lenient_comp_presets")]
+    pub comp_presets: Vec<CompPreset>,
+    /// Top-level keys this version doesn't know (kept for newer versions).
+    #[serde(flatten)]
+    pub extra: Extra,
+}
+
+impl Default for Prefs {
+    fn default() -> Self {
+        Prefs {
+            version: PREFS_VERSION,
+            general: General::default(),
+            startup: Startup::default(),
+            project: ProjectPrefs::default(),
+            auto_save: AutoSave::default(),
+            composition: CompositionPrefs::default(),
+            previews: Previews::default(),
+            appearance: Appearance::default(),
+            grids: Grids::default(),
+            labels: default_labels(),
+            type_: TypePrefs::default(),
+            import: Import::default(),
+            export: Export::default(),
+            audio: Audio::default(),
+            disk: Disk::default(),
+            memory: Memory::default(),
+            video: Video::default(),
+            three_d: ThreeD::default(),
+            scripting: Scripting::default(),
+            roto: RotoPrefs::default(),
+            face: FacePrefs::default(),
+            recent_projects: vec![],
+            recent_footage: vec![],
+            recent_presets: vec![],
+            recent_scripts: vec![],
+            recent_fonts: vec![],
+            effects_favorites: vec![],
+            preview: crate::preview::PreviewSettings::default(),
+            custom_rgb: crate::viewer::CustomRgb::default(),
+            comp_presets: vec![],
+            extra: Extra::new(),
+        }
+    }
+}
diff --git a/crates/engine/src/settings/prefs/choices.rs b/crates/engine/src/settings/prefs/choices.rs
new file mode 100644
index 000000000..4145e0161
--- /dev/null
+++ b/crates/engine/src/settings/prefs/choices.rs
@@ -0,0 +1,63 @@
+/// Settings ▸ General ▸ Language: (label, `general.language` value).
+pub const LANGUAGES: &[(&str, &str)] = &[
+    ("Match System", "system"),
+    ("English", "en"),
+    // Alphabetical by the language's own name after English; Cyrillic, Georgian, then CJK names
+    // follow the Latin ones.
+    ("Čeština", "cs"),
+    ("Deutsch", "de"),
+    ("Español", "es"),
+    ("Français", "fr"),
+    ("Português (Brasil)", "pt-br"),
+    ("Русский", "ru"),
+    ("Українська", "uk"),
+    ("ქართული", "ka"),
+    ("日本語", "ja"),
+    ("简体中文", "zh-hans"),
+    ("繁體中文", "zh-hant"),
+];
+
+/// Settings ▸ Startup & Repair ▸ Window Graphics: (label, `startup.windowGraphics` value).
+pub const WINDOW_GRAPHICS: &[(&str, &str)] = &[("Automatic", "auto"), ("OpenGL (compatibility)", "gl")];
+
+/// Settings ▸ Appearance ▸ Appearance Mode: (label, `appearance.appearanceMode` value). Auto
+/// follows the operating system's light or dark appearance.
+pub const APPEARANCE_MODES: &[(&str, &str)] = &[("Sync with System", "auto"), ("Dark", "dark"), ("Light", "light")];
+
+/// The dark family of themes: (label, `appearance.darkTheme` value).
+pub const DARK_THEMES: &[(&str, &str)] = &[("Dark", "dark"), ("Darker", "darker")];
+
+/// The light family of themes: (label, `appearance.lightTheme` value).
+pub const LIGHT_THEMES: &[(&str, &str)] = &[("Light", "light")];
+
+/// Every theme (the legacy single-theme `appearance.theme`).
+pub const THEMES: &[(&str, &str)] = &[("Dark", "dark"), ("Darker", "darker"), ("Light", "light")];
+
+/// The settings whose value must be one of their choices.
+pub(super) fn choices(key: &str) -> Option<&'static [(&'static str, &'static str)]> {
+    match key {
+        "general.language" => Some(LANGUAGES),
+        "startup.windowGraphics" => Some(WINDOW_GRAPHICS),
+        "appearance.appearanceMode" => Some(APPEARANCE_MODES),
+        "appearance.darkTheme" => Some(DARK_THEMES),
+        "appearance.lightTheme" => Some(LIGHT_THEMES),
+        "appearance.theme" => Some(THEMES),
+        _ => None,
+    }
+}
+
+pub(super) fn is_choice(choices: &[(&str, &str)], v: &str) -> bool {
+    choices.iter().any(|(_, c)| *c == v)
+}
+
+/// The appearance mode and the per-mode setting a theme belongs to (`darker` → (`dark`,
+/// `darkTheme`)); `None` for an unknown theme.
+pub fn theme_family(theme: &str) -> Option<(&'static str, &'static str)> {
+    if is_choice(DARK_THEMES, theme) {
+        Some(("dark", "darkTheme"))
+    } else if is_choice(LIGHT_THEMES, theme) {
+        Some(("light", "lightTheme"))
+    } else {
+        None
+    }
+}
diff --git a/crates/engine/src/settings/prefs/dialog.rs b/crates/engine/src/settings/prefs/dialog.rs
new file mode 100644
index 000000000..e3f2006d8
--- /dev/null
+++ b/crates/engine/src/settings/prefs/dialog.rs
@@ -0,0 +1,430 @@
+use super::choices::{APPEARANCE_MODES, DARK_THEMES, LANGUAGES, LIGHT_THEMES, WINDOW_GRAPHICS};
+use super::{Value, json};
+
+// ---------------------------------------------------------------- schema (Settings dialog)
+
+/// What a setting row edits.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum Kind {
+    Bool,
+    /// Integer with range and unit.
+    Int(i64, i64, &'static str),
+    /// Number with range and unit.
+    Float(f64, f64, &'static str),
+    /// One of (label, value).
+    Choice(&'static [(&'static str, &'static str)]),
+    Text,
+    /// A folder or file path (text + Choose…).
+    Path,
+    /// `#rrggbb`.
+    Color,
+    /// UI brightness slider.
+    Slider(f64, f64),
+}
+
+/// One row of a settings page.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum Item {
+    Section(&'static str),
+    Setting {
+        key: &'static str,
+        label: &'static str,
+        kind: Kind,
+        /// Changes behaviour today (false = shown for parity, listed in docs/preferences.md).
+        live: bool,
+    },
+    /// A button running a command (`params` is JSON).
+    Button {
+        label: &'static str,
+        command: &'static str,
+        params: &'static str,
+    },
+    /// The 16 label names and colours.
+    Labels,
+    /// Output device picker (device list from the host).
+    AudioDevices {
+        key: &'static str,
+    },
+    /// Read-only information line.
+    Note(&'static str),
+    /// The browser's storage manager (web app only, `storage.*`): usage and quota, persistent
+    /// storage, Clear buttons. Not shown where there is no browser storage.
+    BrowserStorage,
+    /// A task's trained models (`roto.models`, `face.models`): authors, licence, size, install,
+    /// choose.
+    Models(effectcraft_segment::Task),
+}
+
+/// One page of the Settings dialog.
+#[derive(Clone, Debug)]
+pub struct Page {
+    pub id: &'static str,
+    pub title: &'static str,
+    pub items: Vec<Item>,
+}
+
+const fn s(key: &'static str, label: &'static str, kind: Kind, live: bool) -> Item {
+    Item::Setting { key, label, kind, live }
+}
+
+const B: Kind = Kind::Bool;
+
+const ON_OFF_RES: &[(&str, &str)] = &[("1/2", "1/2"), ("1/4", "1/4"), ("1/8", "1/8")];
+
+const STYLES: &[(&str, &str)] = &[("Lines", "lines"), ("Dashed Lines", "dashed"), ("Dots", "dots")];
+
+/// The Settings pages in After Effects 2026 order.
+pub fn pages() -> Vec<Page> {
+    use Item::*;
+    vec![
+        Page {
+            id: "general",
+            title: "General",
+            items: vec![
+                s("general.language", "Language", Kind::Choice(LANGUAGES), true),
+                s("general.undoLevels", "Levels of Undo", Kind::Int(1, 99, ""), true),
+                s("general.pathPointSize", "Path Point and Handle Size", Kind::Int(3, 20, "px"), true),
+                s("general.recentItems", "Recent Projects Shown", Kind::Int(1, 30, ""), true),
+                Section("Options"),
+                s("general.showToolTips", "Show Tool Tips", B, true),
+                s("general.createLayersAtCompStart", "Create Layers at Composition Start Time", B, true),
+                s("general.switchesAffectNestedComps", "Switches Affect Nested Comps", B, true),
+                s("general.defaultSpatialLinear", "Default Spatial Interpolation to Linear", B, true),
+                s("general.preserveConstantVertexCount", "Preserve Constant Vertex and Feather Point Count when Editing Masks", B, true),
+                s("general.syncTimeRelatedItems", "Synchronize Time of All Related Items", B, true),
+                s("general.expressionPickWhipCompact", "Expression Pick Whip Writes Compact English", B, true),
+                s("general.createSplitLayersAbove", "Create Split Layers Above Original Layer", B, true),
+                s("general.useSystemColorPicker", "Use System Color Picker", B, false),
+                Note("EffectCraft always uses its own colour picker (the same on every platform and the web)."),
+            ],
+        },
+        Page {
+            id: "startup",
+            title: "Startup & Repair",
+            items: vec![
+                s("startup.showHomeOnLaunch", "Show Home Screen When Launching", B, true),
+                s("startup.showHomeOnOpenProject", "Show Home Screen When Opening a Project", B, true),
+                s("startup.offerCrashRecovery", "Offer to Open the Latest Auto-Save After a Crash", B, true),
+                s("startup.windowGraphics", "Window Graphics", Kind::Choice(WINDOW_GRAPHICS), true),
+                Note(
+                    "Window Graphics applies from the next launch. When the graphics driver stops EffectCraft as its window opens, the next launch switches to OpenGL.",
+                ),
+                Section("Repair"),
+                Button { label: "Reset Settings", command: "prefs.reset", params: "{}" },
+                Button { label: "Reset Keyboard Shortcuts", command: "shortcuts.reset", params: "{}" },
+                Button { label: "Empty Disk Cache", command: "edit.purge", params: r#"{"what":"disk"}"# },
+            ],
+        },
+        Page {
+            id: "project",
+            title: "Project",
+            items: vec![
+                Section("New Project"),
+                s("project.useTemplate", "New Project Loads Template", B, true),
+                s("project.templatePath", "Template Project", Kind::Path, true),
+                Section("Auto-Save"),
+                s("autoSave.enabled", "Automatically Save Projects", B, true),
+                s("autoSave.intervalMinutes", "Save Every", Kind::Int(1, 240, "Minutes"), true),
+                s("autoSave.maxVersions", "Maximum Project Versions", Kind::Int(1, 99, ""), true),
+                s("autoSave.location", "Auto-Save Location", Kind::Choice(&[("Next to Project", "nextToProject"), ("Custom Location", "custom")]), true),
+                s("autoSave.folder", "Custom Location", Kind::Path, true),
+                s("autoSave.saveOnRenderStart", "Save When Starting Render Queue", B, true),
+                Button { label: "Save Now", command: "file.autoSave", params: "{}" },
+            ],
+        },
+        Page {
+            id: "composition",
+            title: "Composition",
+            items: vec![
+                Section("Motion Path"),
+                s(
+                    "composition.motionPath",
+                    "Motion Path",
+                    Kind::Choice(&[
+                        ("All Keyframes", "all"),
+                        ("No Motion Path", "none"),
+                        ("No More Than (Seconds)", "seconds"),
+                        ("No More Than (Keyframes)", "keyframes"),
+                    ]),
+                    true,
+                ),
+                s("composition.motionPathSeconds", "Seconds", Kind::Float(0.0, 3600.0, "s"), true),
+                s("composition.motionPathKeyframes", "Keyframes", Kind::Int(1, 10_000, ""), true),
+                Section("Display"),
+                s("composition.showRenderingProgress", "Show Rendering Progress in Info Panel and Flowchart", B, true),
+                s("composition.hardwareAcceleratePanels", "Hardware Accelerate Composition, Layer and Footage Panels", B, false),
+                Note("Panels are always drawn by the GPU (wgpu)."),
+            ],
+        },
+        Page {
+            id: "previews",
+            title: "Previews",
+            items: vec![
+                s("previews.adaptiveResolutionLimit", "Adaptive Resolution Limit", Kind::Choice(ON_OFF_RES), true),
+                s("previews.showInternalWireframes", "Show Internal Wireframes", B, true),
+                s("previews.cacheFramesWhenIdle", "Cache Frames When Idle", B, true),
+                s("previews.fastPreviews", "Fast Previews (Draft 3D, Faster Effects)", B, true),
+                s("previews.zoomQuality", "Viewer Zoom Quality", Kind::Choice(&[("Faster", "faster"), ("More Accurate", "moreAccurate")]), true),
+                s("previews.displayProfile", "Display Color Space", Kind::Choice(&[("sRGB", "srgb"), ("Display P3", "p3")]), true),
+                Button { label: "GPU Information...", command: "app.gpuInfo", params: "{}" },
+            ],
+        },
+        Page {
+            id: "appearance",
+            title: "Appearance",
+            items: vec![
+                s("appearance.appearanceMode", "Appearance Mode", Kind::Choice(APPEARANCE_MODES), true),
+                s("appearance.lightTheme", "Light Theme", Kind::Choice(LIGHT_THEMES), true),
+                s("appearance.darkTheme", "Dark Theme", Kind::Choice(DARK_THEMES), true),
+                s("appearance.brightness", "Brightness", Kind::Slider(-1.0, 1.0), true),
+                s("appearance.uiScale", "UI Scale", Kind::Int(75, 200, "%"), true),
+                Section("Labels and Colors"),
+                s("appearance.useLabelColorForHandles", "Use Label Color for Layer Handles and Paths", B, true),
+                s("appearance.useLabelColorForTabs", "Use Label Color for Related Tabs", B, true),
+                s("appearance.cycleMaskColors", "Cycle Mask Colors", B, true),
+                s("appearance.useGradients", "Use Gradients", B, true),
+                Section("Menu Bar"),
+                s("appearance.inWindowMenuBarMac", "Use In-Window Menu Bar on macOS", B, true),
+            ],
+        },
+        Page {
+            id: "grids",
+            title: "Grids & Guides",
+            items: vec![
+                Section("Grid"),
+                s("grids.gridColor", "Color", Kind::Color, true),
+                s("grids.gridSpacing", "Gridline Every", Kind::Float(1.0, 10_000.0, "px"), true),
+                s("grids.gridSubdivisions", "Subdivisions", Kind::Int(1, 100, ""), true),
+                s("grids.gridStyle", "Style", Kind::Choice(STYLES), true),
+                Section("Proportional Grid"),
+                s("grids.proportionalHorizontal", "Horizontal", Kind::Int(1, 100, ""), true),
+                s("grids.proportionalVertical", "Vertical", Kind::Int(1, 100, ""), true),
+                Section("Guides"),
+                s("grids.guideColor", "Color", Kind::Color, true),
+                s("grids.guideStyle", "Style", Kind::Choice(STYLES), true),
+                Section("Safe Margins"),
+                s("grids.actionSafe", "Action-safe", Kind::Float(0.0, 50.0, "%"), true),
+                s("grids.titleSafe", "Title-safe", Kind::Float(0.0, 50.0, "%"), true),
+            ],
+        },
+        Page { id: "labels", title: "Labels", items: vec![Labels] },
+        Page {
+            id: "type",
+            title: "Type",
+            items: vec![
+                s("type.textEngine", "Text Engine", Kind::Choice(&[("Latin", "latin"), ("South Asian and Middle Eastern", "southAsian")]), true),
+                s("type.fontPreview", "Show Font Preview", B, true),
+                s("type.recentFonts", "Number of Recent Fonts to Display", Kind::Int(0, 30, ""), true),
+                s("type.fontNamesInEnglish", "Show Font Names in English", B, true),
+            ],
+        },
+        Page {
+            id: "import",
+            title: "Import",
+            items: vec![
+                s("import.stillFootage", "Still Footage", Kind::Choice(&[("Length of Composition", "compLength"), ("Duration (Seconds)", "seconds")]), true),
+                s("import.stillSeconds", "Still Duration", Kind::Float(0.04, 86_400.0, "s"), true),
+                s("import.sequenceFps", "Sequence Footage", Kind::Float(1.0, 999.0, "frames per second"), true),
+                s("import.reportMissingFrames", "Report Missing Frames", B, true),
+                s(
+                    "import.autoReloadFootage",
+                    "Automatically Reload Footage",
+                    Kind::Choice(&[("Off", "off"), ("Non-Sequence Footage", "nonSequence"), ("All Footage", "all")]),
+                    true,
+                ),
+                s(
+                    "import.unlabeledAlpha",
+                    "Interpret Unlabeled Alpha As",
+                    Kind::Choice(&[
+                        ("Ask User", "ask"),
+                        ("Guess", "guess"),
+                        ("Ignore", "ignore"),
+                        ("Straight", "straight"),
+                        ("Premultiplied", "premultiplied"),
+                    ]),
+                    true,
+                ),
+                s(
+                    "import.dragImportAs",
+                    "Default Drag Import As",
+                    Kind::Choice(&[("Footage", "footage"), ("Composition", "comp"), ("Composition - Retain Layer Sizes", "compLayerSizes")]),
+                    true,
+                ),
+            ],
+        },
+        Page {
+            id: "export",
+            title: "Export",
+            items: vec![
+                s("export.defaultOutputFolder", "Default Output Folder", Kind::Path, true),
+                s("export.segmentSequences", "Segment Sequences", B, true),
+                s("export.segmentSequenceFiles", "Files per Segment", Kind::Int(1, 100_000, "files"), true),
+                s("export.segmentMovies", "Segment Movie Files", B, true),
+                s("export.segmentMovieMb", "Segment Size", Kind::Int(1, 1_000_000, "MB"), true),
+                s("export.appendBitsToName", "Append Bit Depth to File Name", B, true),
+            ],
+        },
+        Page {
+            id: "audio",
+            title: "Audio",
+            items: vec![
+                Section("Audio Hardware"),
+                AudioDevices { key: "audio.outputDevice" },
+                s("audio.previewSampleRate", "Preview Sample Rate", Kind::Int(8_000, 192_000, "Hz"), true),
+                Section("Audio Output Mapping"),
+                s("audio.outputLeft", "Left", Kind::Int(1, 64, "channel"), true),
+                s("audio.outputRight", "Right", Kind::Int(1, 64, "channel"), true),
+            ],
+        },
+        Page {
+            id: "disk",
+            title: "Disk",
+            items: vec![
+                Section("Disk Cache"),
+                s("disk.diskCacheEnabled", "Enable Disk Cache", B, true),
+                s("disk.diskCacheMaxGb", "Maximum Disk Cache Size", Kind::Int(1, 100_000, "GB"), true),
+                s("disk.diskCacheFolder", "Disk Cache Folder", Kind::Path, true),
+                Button { label: "Empty Disk Cache", command: "edit.purge", params: r#"{"what":"disk"}"# },
+                BrowserStorage,
+                Section("Media Cache"),
+                s("disk.mediaCacheFolder", "Database and Cache Folder", Kind::Path, true),
+                s("disk.conformedMediaFolder", "Conformed Audio Folder", Kind::Path, true),
+            ],
+        },
+        Page {
+            id: "memory",
+            title: "Memory & CPU",
+            items: vec![
+                s("memory.ramReservedGb", "RAM Reserved for Other Applications", Kind::Int(0, 1024, "GB"), true),
+                Section("Cache Budgets"),
+                s("memory.layerCacheMb", "Layer Cache", Kind::Int(64, 1 << 20, "MB"), true),
+                s("memory.mediaCacheMb", "Footage Frame Cache", Kind::Int(64, 1 << 20, "MB"), true),
+                s("memory.previewCacheMb", "Preview (RAM) Cache", Kind::Int(64, 1 << 20, "MB"), true),
+                s("memory.reduceCacheWhenLow", "Reduce Cache Size When System Is Low on Memory", B, true),
+            ],
+        },
+        Page {
+            id: "video",
+            title: "Video",
+            items: vec![
+                s("video.enableOutput", "Enable Video Preview Output", B, true),
+                s("video.device", "Video Device", Kind::Choice(&[("Floating Window", ""), ("Full Screen", "fullscreen")]), true),
+                s("video.outputDuringPlayback", "Video Output During Playback", B, true),
+                s("video.mirrorOnMonitor", "Mirror on Computer Monitor", B, true),
+                s("video.disableWhenBackground", "Disable Video Output When in Background", B, true),
+            ],
+        },
+        Page {
+            id: "3d",
+            title: "3D",
+            items: vec![
+                s("threeD.defaultRenderer", "Default 3D Renderer", Kind::Choice(&[("Classic 3D", "classic"), ("Advanced 3D", "advanced")]), true),
+                s("threeD.showReferenceAxes", "Show 3D Reference Axes", B, true),
+                s("threeD.extendedViewer", "Extended Viewer", B, true),
+                s("threeD.realtimeShadows", "Realtime Shadows in Draft", B, true),
+            ],
+        },
+        Page {
+            id: "scripting",
+            title: "Scripting & Expressions",
+            items: vec![
+                Section("Application Scripting"),
+                s("scripting.allowScriptsWriteFiles", "Allow Scripts to Write Files and Access Network", B, true),
+                s("scripting.warnExecutingFiles", "Warn User When Executing Files", B, true),
+                s("scripting.enableJsDebugger", "Enable JavaScript Debugger", B, false),
+                Section("Expressions Editor"),
+                s("scripting.editorFontSize", "Font Size", Kind::Int(8, 40, "pt"), true),
+                s("scripting.syntaxHighlighting", "Syntax Highlighting", B, true),
+                s("scripting.lineNumbers", "Line Numbers", B, true),
+                s("scripting.autoComplete", "Auto-complete", B, true),
+                s("scripting.bracketMatching", "Bracket Matching", B, true),
+                s("scripting.wordWrap", "Word Wrap", B, true),
+                s("scripting.errorBanner", "Show Expression Error Banner", B, true),
+                Note("Expressions use the JavaScript engine. Script errors report their file and line in the Script Console; there is no step debugger."),
+            ],
+        },
+        Page {
+            id: "roto",
+            title: "Roto Brush",
+            items: vec![
+                Section("Segmentation Model"),
+                Note(
+                    "Roto Brush 2.0 and 3.0 use the model chosen here (Version 1.0 always uses the classic engine). Models are open source, downloaded only when you ask, and checked against their published SHA-256.",
+                ),
+                Models(effectcraft_segment::Task::Mask),
+            ],
+        },
+        Page {
+            id: "face",
+            title: "Face Tracking",
+            items: vec![
+                Section("Face Model"),
+                Note(
+                    "Face tracking in the Tracker panel (Outline Only and Detailed Features) uses the model chosen here. Models are open source, downloaded only when you ask, and checked against their published SHA-256.",
+                ),
+                Models(effectcraft_segment::Task::Face),
+            ],
+        },
+    ]
+}
+
+/// Keys of every setting that doesn't change behaviour yet (the TODO list in
+/// `docs/preferences.md`).
+pub fn todo_keys() -> Vec<&'static str> {
+    pages()
+        .into_iter()
+        .flat_map(|p| p.items)
+        .filter_map(|i| match i {
+            Item::Setting { key, live: false, .. } => Some(key),
+            _ => None,
+        })
+        .collect()
+}
+
+/// The schema as JSON (for `prefs.pages`).
+pub fn pages_json() -> Value {
+    let kind = |k: &Kind| -> Value {
+        match k {
+            Kind::Bool => json!({"type": "bool"}),
+            Kind::Int(a, b, u) => json!({"type": "int", "min": a, "max": b, "unit": u}),
+            Kind::Float(a, b, u) => json!({"type": "number", "min": a, "max": b, "unit": u}),
+            Kind::Choice(o) => json!({"type": "choice", "options": o.iter().map(|(l, v)| json!({"label": l, "value": v})).collect::<Vec<_>>()}),
+            Kind::Text => json!({"type": "text"}),
+            Kind::Path => json!({"type": "path"}),
+            Kind::Color => json!({"type": "color"}),
+            Kind::Slider(a, b) => json!({"type": "slider", "min": a, "max": b}),
+        }
+    };
+    let pages: Vec<Value> = pages()
+        .iter()
+        .map(|p| {
+            let items: Vec<Value> = p
+                .items
+                .iter()
+                .map(|i| match i {
+                    Item::Section(t) => json!({"section": t}),
+                    Item::Setting { key, label, kind: k, live } => {
+                        let mut o = kind(k);
+                        o["key"] = json!(key);
+                        o["label"] = json!(label);
+                        o["live"] = json!(live);
+                        o
+                    }
+                    Item::Button { label, command, params } => {
+                        json!({"button": label, "command": command, "params": serde_json::from_str::<Value>(params).unwrap_or_default()})
+                    }
+                    Item::Labels => json!({"labels": "labels.N.name / labels.N.color (N = 0..15)"}),
+                    Item::AudioDevices { key } => json!({"type": "device", "key": key, "label": "Default Output"}),
+                    Item::Note(t) => json!({"note": t}),
+                    Item::BrowserStorage => json!({"browserStorage": "storage.info / storage.persist / storage.clear (web app)"}),
+                    Item::Models(task) => {
+                        let p = if *task == effectcraft_segment::Task::Face { "face" } else { "roto" };
+                        json!({"models": format!("{p}.models / {p}.model.select / {p}.model.download / {p}.model.install / {p}.model.remove"), "key": format!("{p}.model")})
+                    }
+                })
+                .collect();
+            json!({"id": p.id, "title": p.title, "items": items})
+        })
+        .collect();
+    json!(pages)
+}
diff --git a/crates/engine/src/settings/prefs/document.rs b/crates/engine/src/settings/prefs/document.rs
new file mode 100644
index 000000000..d82205352
--- /dev/null
+++ b/crates/engine/src/settings/prefs/document.rs
@@ -0,0 +1,325 @@
+use super::choices::{APPEARANCE_MODES, DARK_THEMES, LANGUAGES, LIGHT_THEMES, THEMES, WINDOW_GRAPHICS, choices, is_choice, theme_family};
+use super::recent::{MAX_EFFECTS_FAVORITES, MAX_RECENT_SCRIPTS};
+use super::sections::{CompPreset, default_labels, parse_hex};
+use super::{Appearance, General, Map, PREFS_VERSION, Prefs, Startup, Value, json};
+
+/// Bring an older settings document up to [`PREFS_VERSION`].
+///
+/// - version 0/1 (early builds) kept a flat object: `undoLevels`, `autoSaveEnabled`,
+///   `autoSaveMinutes`, `autoSaveVersions`, `labelNames` (array) and `theme` at the top level.
+/// - version 2 defaulted the disk cache to 100 GB, more than most laptops have free; the stored
+///   old default becomes the new one (a size the user chose is kept).
+pub fn migrate(mut v: Value) -> Value {
+    let Some(obj) = v.as_object_mut() else { return json!({}) };
+    let version = obj.get("version").and_then(Value::as_u64).unwrap_or(0);
+    if version < 2 {
+        let moved = |from: &str, page: &str, key: &str, obj: &mut Map<String, Value>| {
+            if let Some(x) = obj.remove(from) {
+                let p = obj.entry(page.to_string()).or_insert_with(|| json!({}));
+                if let Some(p) = p.as_object_mut() {
+                    p.entry(key.to_string()).or_insert(x);
+                }
+            }
+        };
+        moved("undoLevels", "general", "undoLevels", obj);
+        moved("autoSaveEnabled", "autoSave", "enabled", obj);
+        moved("autoSaveMinutes", "autoSave", "intervalMinutes", obj);
+        moved("autoSaveVersions", "autoSave", "maxVersions", obj);
+        moved("theme", "appearance", "theme", obj);
+        if let Some(Value::Array(names)) = obj.remove("labelNames") {
+            let mut labels = default_labels();
+            for (l, n) in labels.iter_mut().zip(names) {
+                if let Some(n) = n.as_str() {
+                    l.name = n.to_string();
+                }
+            }
+            obj.insert("labels".into(), serde_json::to_value(labels).unwrap_or_default());
+        }
+    }
+    if version < 3
+        && let Some(d) = obj.get_mut("disk").and_then(Value::as_object_mut)
+        && d.get("diskCacheMaxGb").and_then(Value::as_u64) == Some(100)
+    {
+        d.insert("diskCacheMaxGb".into(), json!(20));
+    }
+    // Settings saved before appearance modes had one theme: keep showing it, as a fixed Dark or
+    // Light mode, instead of switching established users to Auto.
+    if let Some(a) = obj.get_mut("appearance").and_then(Value::as_object_mut)
+        && !a.contains_key("appearanceMode")
+        && let Some(theme) = a.get("theme").and_then(Value::as_str).map(str::to_string)
+        && let Some((mode, slot)) = theme_family(&theme)
+    {
+        a.insert("appearanceMode".into(), json!(mode));
+        a.insert(slot.into(), json!(theme));
+    }
+    obj.insert("version".into(), json!(PREFS_VERSION));
+    v
+}
+
+impl Prefs {
+    /// Parse a settings document (migrating older layouts; unknown keys are kept, bad values
+    /// fall back to defaults).
+    pub fn from_json(text: &str) -> Prefs {
+        let v: Value = serde_json::from_str(text).unwrap_or_else(|_| json!({}));
+        let v = migrate(v);
+        let mut p: Prefs = match serde_json::from_value(v.clone()) {
+            Ok(p) => p,
+            // One bad value shouldn't lose everything: take each page that parses.
+            Err(_) => {
+                let mut base = serde_json::to_value(Prefs::default()).unwrap_or_default();
+                if let (Some(b), Some(o)) = (base.as_object_mut(), v.as_object()) {
+                    for (k, x) in o {
+                        let mut trial = b.clone();
+                        trial.insert(k.clone(), x.clone());
+                        if serde_json::from_value::<Prefs>(Value::Object(trial)).is_ok() {
+                            b.insert(k.clone(), x.clone());
+                        }
+                    }
+                }
+                serde_json::from_value(base).unwrap_or_default()
+            }
+        };
+        p.normalize();
+        p
+    }
+
+    pub fn to_json(&self) -> String {
+        serde_json::to_string_pretty(self).unwrap_or_default()
+    }
+
+    /// Clamp values into their valid ranges and fill missing labels.
+    pub fn normalize(&mut self) {
+        self.version = PREFS_VERSION;
+        self.comp_presets.retain(CompPreset::is_valid);
+        let mut seen = std::collections::HashSet::new();
+        self.effects_favorites.retain(|id| !id.is_empty() && seen.insert(id.clone()));
+        self.effects_favorites.truncate(MAX_EFFECTS_FAVORITES);
+        if !is_choice(WINDOW_GRAPHICS, &self.startup.window_graphics) {
+            self.startup.window_graphics = Startup::default().window_graphics;
+        }
+        let g = &mut self.general;
+        if !is_choice(LANGUAGES, &g.language) {
+            g.language = General::default().language;
+        }
+        g.undo_levels = g.undo_levels.clamp(1, 99);
+        g.path_point_size = g.path_point_size.clamp(3, 20);
+        g.recent_items = g.recent_items.clamp(1, 30);
+        let a = &mut self.auto_save;
+        a.interval_minutes = a.interval_minutes.clamp(1, 240);
+        a.max_versions = a.max_versions.clamp(1, 99);
+        let ap = &mut self.appearance;
+        let mut seen = std::collections::BTreeSet::new();
+        ap.favorite_themes.retain(|id| is_choice(THEMES, id) && seen.insert(id.clone()));
+        if !is_choice(APPEARANCE_MODES, &ap.appearance_mode) {
+            ap.appearance_mode = Appearance::default().appearance_mode;
+        }
+        if !is_choice(DARK_THEMES, &ap.dark_theme) {
+            ap.dark_theme = Appearance::default().dark_theme;
+        }
+        if !is_choice(LIGHT_THEMES, &ap.light_theme) {
+            ap.light_theme = Appearance::default().light_theme;
+        }
+        // The legacy single theme mirrors the theme a fixed mode shows (Auto depends on the
+        // system, so it keeps the last one).
+        match ap.appearance_mode.as_str() {
+            "dark" => ap.theme = ap.dark_theme.clone(),
+            "light" => ap.theme = ap.light_theme.clone(),
+            _ if !is_choice(THEMES, &ap.theme) => ap.theme = ap.dark_theme.clone(),
+            _ => {}
+        }
+        self.appearance.brightness = self.appearance.brightness.clamp(-1.0, 1.0);
+        self.appearance.ui_scale = self.appearance.ui_scale.clamp(75, 200);
+        let defaults = default_labels();
+        self.labels.truncate(defaults.len());
+        for d in defaults.iter().skip(self.labels.len()) {
+            self.labels.push(d.clone());
+        }
+        for (l, d) in self.labels.iter_mut().zip(&defaults) {
+            if parse_hex(&l.color).is_none() {
+                l.color = d.color.clone();
+            }
+        }
+        let m = &mut self.memory;
+        m.layer_cache_mb = m.layer_cache_mb.clamp(64, 1 << 20);
+        m.media_cache_mb = m.media_cache_mb.clamp(64, 1 << 20);
+        m.preview_cache_mb = m.preview_cache_mb.clamp(64, 1 << 20);
+        self.grids.grid_spacing = self.grids.grid_spacing.clamp(1.0, 10_000.0);
+        let n = self.general.recent_items as usize;
+        self.recent_projects.truncate(n);
+        self.recent_scripts.truncate(MAX_RECENT_SCRIPTS);
+    }
+
+    /// The value at a dotted key (`general.undoLevels`, `labels.3.color`); `""` = everything.
+    pub fn get(&self, key: &str) -> Option<Value> {
+        let v = serde_json::to_value(self).ok()?;
+        if key.is_empty() {
+            return Some(v);
+        }
+        let ptr = format!("/{}", key.replace('.', "/"));
+        v.pointer(&ptr).cloned()
+    }
+
+    /// Set the value at a dotted key. The key must exist and the value must have its type.
+    pub fn set(&mut self, key: &str, value: Value) -> Result<(), String> {
+        if let Some(c) = choices(key)
+            && !value.as_str().is_some_and(|v| is_choice(c, v))
+        {
+            let all: Vec<&str> = c.iter().map(|(_, v)| *v).collect();
+            return Err(format!("`{key}` expects one of {}", all.join(", ")));
+        }
+        let favorites = if key == "appearance.favoriteThemes" {
+            Some(&value)
+        } else if key == "appearance" {
+            value.get("favoriteThemes")
+        } else {
+            None
+        };
+        if let Some(favorites) = favorites {
+            let values = favorites.as_array().ok_or("favorite themes must be a list")?;
+            let mut seen = std::collections::BTreeSet::new();
+            for value in values {
+                let id = value.as_str().ok_or("favorite theme must be a string")?;
+                if !is_choice(THEMES, id) || !seen.insert(id) {
+                    return Err("unknown or duplicate favorite theme".into());
+                }
+            }
+        }
+        // Older clients set the single theme (by key, or inside the page object): it still picks
+        // a visible theme, fixing the mode to its family.
+        let legacy_theme = key == "appearance.theme" || (key == "appearance" && value.get("theme").is_some() && value.get("appearanceMode").is_none());
+        let mut v = serde_json::to_value(&*self).map_err(|e| e.to_string())?;
+        let ptr = format!("/{}", key.replace('.', "/"));
+        let slot = v.pointer_mut(&ptr).ok_or_else(|| format!("unknown setting `{key}`"))?;
+        let value = coerce(slot, value).ok_or_else(|| format!("`{key}` expects a {}", kind_name(slot)))?;
+        *slot = value;
+        let mut next: Prefs = serde_json::from_value(v).map_err(|e| format!("`{key}`: {e}"))?;
+        let (a, b) = (&self.appearance, &next.appearance);
+        let only_theme_changed = a.theme != b.theme && a.appearance_mode == b.appearance_mode && a.dark_theme == b.dark_theme && a.light_theme == b.light_theme;
+        if legacy_theme || only_theme_changed {
+            next.appearance.select_theme();
+        }
+        next.normalize();
+        *self = next;
+        Ok(())
+    }
+
+    /// Reset one page (`general`, `labels`, `autoSave`…) or everything (`None`). Open Recent and
+    /// the saved composition presets are kept.
+    pub fn reset(&mut self, page: Option<&str>) -> Result<(), String> {
+        let d = Prefs::default();
+        let Some(page) = page else {
+            *self = Prefs {
+                recent_projects: std::mem::take(&mut self.recent_projects),
+                recent_footage: std::mem::take(&mut self.recent_footage),
+                recent_presets: std::mem::take(&mut self.recent_presets),
+                recent_scripts: std::mem::take(&mut self.recent_scripts),
+                recent_fonts: std::mem::take(&mut self.recent_fonts),
+                effects_favorites: std::mem::take(&mut self.effects_favorites),
+                preview: std::mem::take(&mut self.preview),
+                comp_presets: std::mem::take(&mut self.comp_presets),
+                ..d
+            };
+            return Ok(());
+        };
+        let keys: Vec<&str> = match page {
+            "project" => vec!["project", "autoSave"],
+            p => vec![section_key(p).ok_or_else(|| format!("unknown settings page `{p}`"))?],
+        };
+        let dv = serde_json::to_value(&d).map_err(|e| e.to_string())?;
+        for k in keys {
+            if let Some(x) = dv.get(k) {
+                self.set(k, x.clone())?;
+            }
+        }
+        Ok(())
+    }
+}
+
+/// Settings key of a page id (`3d` → `threeD`).
+pub fn section_key(page: &str) -> Option<&'static str> {
+    Some(match page {
+        "general" => "general",
+        "startup" => "startup",
+        "project" => "project",
+        "autoSave" | "autosave" => "autoSave",
+        "composition" | "display" => "composition",
+        "previews" => "previews",
+        "appearance" => "appearance",
+        "grids" => "grids",
+        "labels" => "labels",
+        "type" => "type",
+        "import" => "import",
+        "export" => "export",
+        "audio" => "audio",
+        "disk" => "disk",
+        "memory" => "memory",
+        "video" => "video",
+        "3d" | "threeD" => "threeD",
+        "scripting" => "scripting",
+        "roto" => "roto",
+        "face" => "face",
+        _ => return None,
+    })
+}
+
+/// Settings page id for a page name, including older After Effects page names
+/// (Auto-Save → Project, Media & Disk Cache → Disk, Memory & Performance → Memory & CPU…).
+pub fn page_id(name: &str) -> Option<&'static str> {
+    let n = name.to_ascii_lowercase().replace([' ', '&', '-', '_'], "");
+    let id = match n.as_str() {
+        "general" => "general",
+        "startup" | "startuprepair" => "startup",
+        "project" | "autosave" | "newproject" => "project",
+        "composition" | "display" => "composition",
+        "previews" | "preview" => "previews",
+        "appearance" => "appearance",
+        "grids" | "gridsguides" => "grids",
+        "labels" => "labels",
+        "type" => "type",
+        "import" => "import",
+        "export" | "output" => "export",
+        "audio" | "audiohardware" | "audiooutputmapping" => "audio",
+        "disk" | "mediadiskcache" | "mediacache" => "disk",
+        "memory" | "memorycpu" | "memoryperformance" => "memory",
+        "video" | "videopreview" => "video",
+        "3d" | "threed" => "3d",
+        "scripting" | "scriptingexpressions" => "scripting",
+        "roto" | "rotobrush" | "models" => "roto",
+        "face" | "facetracking" => "face",
+        _ => return None,
+    };
+    Some(id)
+}
+
+fn kind_name(v: &Value) -> &'static str {
+    match v {
+        Value::Bool(_) => "boolean",
+        Value::Number(_) => "number",
+        Value::String(_) => "string",
+        Value::Array(_) => "list",
+        Value::Object(_) => "object",
+        Value::Null => "value",
+    }
+}
+
+/// `value` converted to the type of `slot` (numbers from strings, booleans from 0/1…).
+fn coerce(slot: &Value, value: Value) -> Option<Value> {
+    Some(match (slot, value) {
+        (Value::Bool(_), Value::Bool(b)) => json!(b),
+        (Value::Bool(_), Value::Number(n)) => json!(n.as_f64()? != 0.0),
+        (Value::Bool(_), Value::String(s)) => json!(matches!(s.as_str(), "true" | "on" | "1" | "yes")),
+        (Value::Number(cur), v) => {
+            let f = match &v {
+                Value::Number(n) => n.as_f64()?,
+                Value::String(s) => s.trim().parse().ok()?,
+                _ => return None,
+            };
+            if cur.is_u64() || cur.is_i64() { json!(f.round().max(0.0) as u64) } else { json!(f) }
+        }
+        (Value::String(_), Value::String(s)) => json!(s),
+        (Value::String(_), Value::Number(n)) => json!(n.to_string()),
+        (Value::Array(_), v @ Value::Array(_)) => v,
+        (Value::Object(_), v @ Value::Object(_)) => v,
+        _ => return None,
+    })
+}
diff --git a/crates/engine/src/settings/prefs/queries.rs b/crates/engine/src/settings/prefs/queries.rs
new file mode 100644
index 000000000..74be30f8f
--- /dev/null
+++ b/crates/engine/src/settings/prefs/queries.rs
@@ -0,0 +1,208 @@
+use super::sections::parse_hex;
+use super::{Label, Prefs, Serialize, Tick};
+
+impl Prefs {
+    /// Display name of a label (Labels settings).
+    pub fn label_name(&self, l: Label) -> String {
+        match label_index(l) {
+            Some(i) => self.labels.get(i).map(|p| p.name.clone()).unwrap_or_else(|| l.name().to_string()),
+            None => l.name().to_string(),
+        }
+    }
+
+    /// sRGB colour of a label (Labels settings).
+    pub fn label_rgb(&self, l: Label) -> [u8; 3] {
+        label_index(l).and_then(|i| self.labels.get(i)).and_then(|p| parse_hex(&p.color)).unwrap_or(l.rgb())
+    }
+
+    /// A label by its built-in name or its (renamed) display name.
+    pub fn label_from_name(&self, s: &str) -> Option<Label> {
+        Label::from_name(s).or_else(|| Label::ALL.iter().skip(1).copied().find(|l| self.label_name(*l).eq_ignore_ascii_case(s)))
+    }
+
+    /// Layer / media / preview cache budgets in bytes.
+    pub fn layer_cache_bytes(&self) -> usize {
+        (self.memory.layer_cache_mb as usize) << 20
+    }
+
+    pub fn media_cache_bytes(&self) -> usize {
+        (self.memory.media_cache_mb as usize) << 20
+    }
+
+    pub fn preview_cache_bytes(&self) -> usize {
+        (self.memory.preview_cache_mb as usize) << 20
+    }
+
+    /// The adaptive resolution limit as a render-scale floor (1/2 → 0.5).
+    pub fn adaptive_limit(&self) -> f64 {
+        match self.previews.adaptive_resolution_limit.as_str() {
+            "1/2" => 0.5,
+            "1/4" => 0.25,
+            _ => 0.125,
+        }
+    }
+
+    /// The Memory & CPU cache budgets in effect: the configured layer / footage / preview
+    /// budgets, scaled down so together they leave **RAM Reserved for Other Applications** free,
+    /// and halved while the system is low on memory when **Reduce Cache Size When System Is Low
+    /// on Memory** is on. `mem` = the system's memory (`None` = unknown: configured budgets).
+    /// In the browser the layer and footage caches also stay within [`WEB_LAYER_CACHE`] and
+    /// [`WEB_MEDIA_CACHE`].
+    pub fn cache_budgets(&self, mem: Option<crate::sysinfo::SysMemory>) -> CacheBudgets {
+        self.cache_budgets_in(mem, cfg!(target_arch = "wasm32"))
+    }
+
+    /// [`Prefs::cache_budgets`], in the browser's memory (`web`) or not.
+    pub(crate) fn cache_budgets_in(&self, mem: Option<crate::sysinfo::SysMemory>, web: bool) -> CacheBudgets {
+        let (mut l, mut m, mut p) = (self.layer_cache_bytes() as u64, self.media_cache_bytes() as u64, self.preview_cache_bytes() as u64);
+        if web {
+            (l, m) = (l.min(WEB_LAYER_CACHE), m.min(WEB_MEDIA_CACHE));
+        }
+        let floor = 64u64 << 20;
+        let mut capped = false;
+        let mut reduced = false;
+        if let Some(mem) = mem.filter(|m| m.total > 0) {
+            let reserved = (self.memory.ram_reserved_gb as u64) << 30;
+            let cap = mem.total.saturating_sub(reserved).max(3 * floor);
+            let sum = l + m + p;
+            if sum > cap {
+                let k = cap as f64 / sum as f64;
+                (l, m, p) = ((l as f64 * k) as u64, (m as f64 * k) as u64, (p as f64 * k) as u64);
+                capped = true;
+            }
+            if self.memory.reduce_cache_when_low && mem.is_low() {
+                (l, m, p) = (l / 2, m / 2, p / 2);
+                reduced = true;
+            }
+        }
+        CacheBudgets { layer: l.max(floor) as usize, media: m.max(floor) as usize, preview: p.max(floor) as usize, capped, reduced }
+    }
+
+    /// Composition ▸ Motion Path: the layer-time span of a motion path to draw around `now`
+    /// (layer time), for keyframes at `keys` (sorted). `None` = No Motion Path.
+    pub fn motion_path_span(&self, keys: &[Tick], now: Tick) -> Option<(Tick, Tick)> {
+        let (first, last) = (*keys.first()?, *keys.last()?);
+        let c = &self.composition;
+        match c.motion_path.as_str() {
+            "none" => None,
+            "seconds" => {
+                let half = Tick::from_seconds_f64(c.motion_path_seconds.max(0.0) / 2.0);
+                let (a, b) = ((now - half).max(first), (now + half).min(last));
+                (a < b).then_some((a, b))
+            }
+            "keyframes" => {
+                let n = (c.motion_path_keyframes.max(1) as usize).min(keys.len());
+                if n < 2 {
+                    return None;
+                }
+                // The n keyframes centred on the current time.
+                let at = keys.partition_point(|k| *k < now);
+                let start = at.saturating_sub(n / 2).min(keys.len() - n);
+                Some((keys[start], keys[start + n - 1]))
+            }
+            _ => Some((first, last)),
+        }
+    }
+
+    /// Previews ▸ Viewer Zoom Quality: smooth (bilinear) scaling of the viewer image, or nearest
+    /// neighbour ("Faster").
+    pub fn viewer_zoom_smooth(&self) -> bool {
+        self.previews.zoom_quality != "faster"
+    }
+
+    /// Import ▸ Interpret Unlabeled Alpha As, for footage whose file has an alpha channel that
+    /// doesn't state how it is stored. `None` = Ask User (keep straight and open Interpret
+    /// Footage); `guess` takes premultiplied for movies (codecs with alpha are usually written
+    /// premultiplied) and straight for stills.
+    pub fn unlabeled_alpha(&self, movie: bool) -> Option<effectcraft_project::AlphaMode> {
+        use effectcraft_project::AlphaMode::*;
+        Some(match self.import.unlabeled_alpha.as_str() {
+            "ignore" => Ignore,
+            "straight" => Straight,
+            "premultiplied" => Premultiplied,
+            "guess" if movie => Premultiplied,
+            "guess" => Straight,
+            _ => return None,
+        })
+    }
+
+    /// Import ▸ Default Drag Import As, as `file.import`'s `importAs`.
+    pub fn drag_import_as(&self) -> &'static str {
+        match self.import.drag_import_as.as_str() {
+            "comp" => "composition",
+            "compLayerSizes" => "compositionLayerSizes",
+            _ => "footage",
+        }
+    }
+
+    /// Export ▸ Append Bit Depth to File Name: `Comp 1.png` → `Comp 1_16bpc.png` (sequence frame
+    /// runs and folders are kept).
+    pub fn output_name(&self, path: &str, bits: u32) -> String {
+        if !self.export.append_bits_to_name {
+            return path.to_string();
+        }
+        let p = std::path::Path::new(path);
+        let (Some(stem), dir) = (p.file_stem().map(|s| s.to_string_lossy().to_string()), p.parent()) else { return path.to_string() };
+        let tag = format!("_{bits}bpc");
+        if stem.ends_with(&tag) {
+            return path.to_string();
+        }
+        let name = match p.extension() {
+            Some(e) => format!("{stem}{tag}.{}", e.to_string_lossy()),
+            None => format!("{stem}{tag}"),
+        };
+        match dir.filter(|d| !d.as_os_str().is_empty()) {
+            Some(d) => d.join(name).to_string_lossy().to_string(),
+            None => name,
+        }
+    }
+
+    /// Export ▸ Segment Sequences / Segment Movie Files: how many frames go in each segment of an
+    /// output of `frames` frames (`None` = one file / folder). Sequences split every Files per
+    /// Segment frames; movies every Segment Size MB at the output's data rate
+    /// (`bytes_per_frame`, estimated from the format's bitrate).
+    pub fn segment_frames(&self, frames: u64, sequence: bool, bytes_per_frame: f64) -> Option<u64> {
+        let e = &self.export;
+        let per = if sequence {
+            e.segment_sequences.then_some(e.segment_sequence_files.max(1) as u64)?
+        } else {
+            if !e.segment_movies || bytes_per_frame <= 0.0 {
+                return None;
+            }
+            (((e.segment_movie_mb.max(1) as f64) * 1_048_576.0 / bytes_per_frame).floor() as u64).max(1)
+        };
+        (per < frames).then_some(per)
+    }
+}
+
+/// The most the layer cache holds in the browser. A wasm32 page addresses at most 4 GiB, which
+/// these caches share with the app and with the decoders' own decoded frames (FilmCraft keeps
+/// up to 384 MB per open movie): with the desktop's 1 GB defaults, eight stacked 1080p clips ran
+/// the page out of memory a few seconds into playback.
+pub const WEB_LAYER_CACHE: u64 = 512 << 20;
+
+/// The most the footage frame cache holds in the browser (see [`WEB_LAYER_CACHE`]).
+pub const WEB_MEDIA_CACHE: u64 = 256 << 20;
+
+/// Effective cache budgets in bytes (see [`Prefs::cache_budgets`]).
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize)]
+pub struct CacheBudgets {
+    pub layer: usize,
+    pub media: usize,
+    pub preview: usize,
+    /// Scaled down to leave the reserved RAM free.
+    pub capped: bool,
+    /// Halved because the system is low on memory.
+    pub reduced: bool,
+}
+
+/// Colour of the `k`-th mask of a layer: Appearance ▸ Cycle Mask Colors cycles through the mask
+/// colours, otherwise every new mask takes the first one.
+pub fn mask_color(cycle: bool, k: usize) -> [u8; 3] {
+    use effectcraft_project::build::MASK_COLORS;
+    if cycle { MASK_COLORS[k % MASK_COLORS.len()] } else { MASK_COLORS[0] }
+}
+
+fn label_index(l: Label) -> Option<usize> {
+    Label::ALL.iter().position(|x| *x == l).and_then(|i| i.checked_sub(1))
+}
diff --git a/crates/engine/src/settings/prefs/recent.rs b/crates/engine/src/settings/prefs/recent.rs
new file mode 100644
index 000000000..2b12499f4
--- /dev/null
+++ b/crates/engine/src/settings/prefs/recent.rs
@@ -0,0 +1,87 @@
+use serde::{Deserialize, Serialize};
+
+use super::Prefs;
+
+impl Prefs {
+    /// Remember a project in File ▸ Open Recent.
+    pub fn push_recent(&mut self, path: &str) {
+        self.recent_projects.retain(|p| p != path);
+        self.recent_projects.insert(0, path.to_string());
+        self.recent_projects.truncate(self.general.recent_items as usize);
+    }
+
+    /// Remember a font in the Character panel's recent fonts (Type ▸ Number of Recent Fonts).
+    pub fn push_recent_font(&mut self, family: &str) {
+        push_mru(&mut self.recent_fonts, family, 30);
+    }
+
+    /// Is effect `id` starred in Effects & Presets?
+    pub fn is_effect_favorite(&self, id: &str) -> bool {
+        self.effects_favorites.iter().any(|f| f == id)
+    }
+
+    /// Star effect `id` in Effects & Presets, or un-star it; true when it is starred now.
+    pub fn toggle_effect_favorite(&mut self, id: &str) -> bool {
+        if self.is_effect_favorite(id) {
+            self.effects_favorites.retain(|f| f != id);
+            false
+        } else {
+            self.effects_favorites.push(id.to_string());
+            self.effects_favorites.truncate(MAX_EFFECTS_FAVORITES);
+            self.is_effect_favorite(id)
+        }
+    }
+
+    /// The recent fonts the Character panel shows (at most Number of Recent Fonts to Display).
+    pub fn recent_fonts_shown(&self) -> &[String] {
+        let n = (self.type_.recent_fonts as usize).min(self.recent_fonts.len());
+        &self.recent_fonts[..n]
+    }
+
+    /// Remember imported footage for File ▸ Import Recent Footage.
+    pub fn push_recent_footage(&mut self, path: &str) {
+        push_mru(&mut self.recent_footage, path, self.general.recent_items as usize);
+    }
+
+    /// Remember an applied animation preset for Animation ▸ Recent Animation Presets.
+    pub fn push_recent_preset(&mut self, path: &str) {
+        push_mru(&mut self.recent_presets, path, self.general.recent_items as usize);
+    }
+
+    /// Remember a script that ran for File ▸ Scripts ▸ Recent Script Files.
+    pub fn push_recent_script(&mut self, script: RecentScript) {
+        self.recent_scripts.retain(|x| *x != script);
+        self.recent_scripts.insert(0, script);
+        self.recent_scripts.truncate(MAX_RECENT_SCRIPTS);
+    }
+}
+
+/// Most scripts File ▸ Scripts ▸ Recent Script Files lists.
+pub const MAX_RECENT_SCRIPTS: usize = 10;
+
+/// A File ▸ Scripts ▸ Recent Script Files entry, stored as the `file.runScript` parameter that
+/// ran it: `{"path": …}` for a script file, `{"name": …}` for an installed or bundled script.
+#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub enum RecentScript {
+    Path(String),
+    Name(String),
+}
+
+impl RecentScript {
+    /// The file's path or the script's name.
+    pub fn text(&self) -> &str {
+        match self {
+            RecentScript::Path(s) | RecentScript::Name(s) => s,
+        }
+    }
+}
+
+/// Most effects Effects & Presets keeps starred (a hand-edited settings file can hold more).
+pub(super) const MAX_EFFECTS_FAVORITES: usize = 1000;
+
+fn push_mru(list: &mut Vec<String>, v: &str, max: usize) {
+    list.retain(|x| x != v);
+    list.insert(0, v.to_string());
+    list.truncate(max.max(1));
+}
diff --git a/crates/engine/src/settings/prefs/sections.rs b/crates/engine/src/settings/prefs/sections.rs
new file mode 100644
index 000000000..e0bea8b85
--- /dev/null
+++ b/crates/engine/src/settings/prefs/sections.rs
@@ -0,0 +1,352 @@
+use super::choices::theme_family;
+use super::{BTreeMap, Deserialize, Label, Serialize, Value};
+
+/// Unknown keys inside a page, kept so a newer version's settings survive a round trip.
+pub(super) type Extra = BTreeMap<String, Value>;
+
+macro_rules! page {
+    ($(#[$m:meta])* $name:ident { $($(#[$fm:meta])* $f:ident : $t:ty = $d:expr),* $(,)? }) => {
+        $(#[$m])*
+        #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+        #[serde(default, rename_all = "camelCase")]
+        pub struct $name {
+            $($(#[$fm])* pub $f: $t,)*
+            #[serde(flatten)]
+            pub extra: Extra,
+        }
+        impl Default for $name {
+            fn default() -> Self {
+                $name { $($f: $d,)* extra: Extra::new() }
+            }
+        }
+    };
+}
+
+page!(General {
+    /// Interface language: `system` (the operating system's, where EffectCraft has it, else
+    /// English), or a language code from `LANGUAGES`.
+    language: String = "system".into(),
+    /// Levels of Undo (1–99).
+    undo_levels: u32 = 32,
+    /// Path Point and Handle Size (px).
+    path_point_size: u32 = 5,
+    show_tool_tips: bool = true,
+    /// Create New Layers at Composition Start Time (off: at the current time).
+    create_layers_at_comp_start: bool = true,
+    switches_affect_nested_comps: bool = true,
+    /// Default Spatial Interpolation to Linear.
+    default_spatial_linear: bool = false,
+    preserve_constant_vertex_count: bool = true,
+    /// Synchronize Time of All Related Items.
+    sync_time_related_items: bool = true,
+    expression_pick_whip_compact: bool = true,
+    /// Create Split Layers Above Original Layer (After Effects' default).
+    create_split_layers_above: bool = true,
+    use_system_color_picker: bool = false,
+    /// Number of projects in File ▸ Open Recent.
+    recent_items: u32 = 10,
+});
+
+page!(Startup {
+    show_home_on_launch: bool = true,
+    show_home_on_open_project: bool = false,
+    /// After a crash, offer to open the most recent auto-save.
+    offer_crash_recovery: bool = true,
+    /// What the desktop window draws with, from the next launch: `auto` (the platform's best
+    /// graphics API) or `gl` (OpenGL, for drivers that crash with the others). A launch that
+    /// stops as its window opens switches it to `gl` (#243).
+    window_graphics: String = "auto".into(),
+});
+
+page!(ProjectPrefs {
+    /// Open a template project for File ▸ New ▸ New Project.
+    use_template: bool = false,
+    template_path: String = String::new(),
+});
+
+page!(AutoSave {
+    enabled: bool = true,
+    interval_minutes: u32 = 20,
+    max_versions: u32 = 5,
+    /// `nextToProject` (an "EffectCraft Auto-Save" folder beside the project) or `custom`.
+    location: String = "nextToProject".into(),
+    folder: String = String::new(),
+    save_on_render_start: bool = false,
+});
+
+page!(CompositionPrefs {
+    /// Motion path: `all`, `none`, `seconds`, `keyframes`.
+    motion_path: String = "keyframes".into(),
+    motion_path_seconds: f64 = 15.0,
+    motion_path_keyframes: u32 = 15,
+    show_rendering_progress: bool = true,
+    hardware_accelerate_panels: bool = true,
+});
+
+page!(Previews {
+    /// Largest downsampling while playing back: `1/2`, `1/4`, `1/8`.
+    adaptive_resolution_limit: String = "1/8".into(),
+    show_internal_wireframes: bool = false,
+    cache_frames_when_idle: bool = false,
+    fast_previews: bool = false,
+    /// `faster` or `moreAccurate`.
+    zoom_quality: String = "moreAccurate".into(),
+    show_gpu_info: bool = false,
+    /// The monitor's colour space for View ▸ Use Display Color Management: `srgb` or `p3`.
+    display_profile: String = "srgb".into(),
+});
+
+page!(Appearance {
+    /// The single theme before appearance modes (`dark`, `darker` or `light`), kept for older
+    /// settings files and automation: setting it picks its family's mode and theme. While the mode
+    /// is Dark or Light it mirrors the theme in use.
+    theme: String = "dark".into(),
+    /// `auto` (follow the operating system), `dark` or `light`. New installs stay Dark.
+    appearance_mode: String = "dark".into(),
+    /// The theme used in dark appearance: `dark` or `darker`.
+    dark_theme: String = "dark".into(),
+    /// The theme used in light appearance: `light`.
+    light_theme: String = "light".into(),
+    /// Theme shortcuts in the appearance context menu.
+    favorite_themes: Vec<String> = Vec::new(),
+    /// User interface brightness, -1 (darker) … 1 (lighter).
+    brightness: f64 = 0.0,
+    /// The size of the whole interface in percent (75–200), on top of the display's own scale.
+    ui_scale: u32 = 100,
+    use_label_color_for_handles: bool = true,
+    use_label_color_for_tabs: bool = true,
+    cycle_mask_colors: bool = true,
+    use_gradients: bool = true,
+    /// macOS: draw the menu bar inside the window instead of the system menu bar.
+    in_window_menu_bar_mac: bool = false,
+});
+
+page!(Grids {
+    grid_color: String = "#7a9cff".into(),
+    grid_spacing: f64 = 100.0,
+    grid_subdivisions: u32 = 4,
+    /// `lines`, `dashed` or `dots`.
+    grid_style: String = "lines".into(),
+    proportional_horizontal: u32 = 4,
+    proportional_vertical: u32 = 4,
+    guide_color: String = "#3cc8f0".into(),
+    guide_style: String = "lines".into(),
+    action_safe: f64 = 10.0,
+    title_safe: f64 = 20.0,
+});
+
+page!(TypePrefs {
+    /// `latin` or `southAsian` (South Asian and Middle Eastern).
+    text_engine: String = "latin".into(),
+    font_preview: bool = true,
+    recent_fonts: u32 = 10,
+    font_names_in_english: bool = false,
+});
+
+page!(Import {
+    /// Still footage duration: `compLength` or `seconds`.
+    still_footage: String = "compLength".into(),
+    still_seconds: f64 = 5.0,
+    sequence_fps: f64 = 30.0,
+    report_missing_frames: bool = true,
+    /// Automatically Reload Footage whose file another app changed (size or modification time),
+    /// checked every two seconds and when the window comes back to the front: `off`,
+    /// `nonSequence` (the default, as in After Effects: image sequences are left alone) or `all`.
+    auto_reload_footage: String = "nonSequence".into(),
+    /// Interpret unlabeled alpha as: `ask`, `guess`, `ignore`, `straight`, `premultiplied`.
+    unlabeled_alpha: String = "ask".into(),
+    /// Default drag import as: `footage`, `comp`, `compLayerSizes`.
+    drag_import_as: String = "footage".into(),
+});
+
+page!(Export {
+    default_output_folder: String = String::new(),
+    segment_sequences: bool = false,
+    segment_sequence_files: u32 = 700,
+    segment_movies: bool = false,
+    segment_movie_mb: u32 = 1024,
+    append_bits_to_name: bool = false,
+});
+
+page!(Audio {
+    /// Output device name (empty = the system default).
+    output_device: String = String::new(),
+    /// Output mapping: device channel for the left / right output (1-based).
+    output_left: u32 = 1,
+    output_right: u32 = 2,
+    preview_sample_rate: u32 = 48_000,
+});
+
+page!(Disk {
+    disk_cache_enabled: bool = true,
+    disk_cache_max_gb: u32 = 20,
+    disk_cache_folder: String = String::new(),
+    media_cache_folder: String = String::new(),
+    conformed_media_folder: String = String::new(),
+});
+
+page!(Memory {
+    ram_reserved_gb: u32 = 6,
+    /// Processed-layer cache budget (MB).
+    layer_cache_mb: u32 = 1024,
+    /// Decoded footage frame cache budget (MB).
+    media_cache_mb: u32 = 1024,
+    /// RAM preview (viewer frame) cache budget (MB).
+    preview_cache_mb: u32 = 3072,
+    reduce_cache_when_low: bool = true,
+});
+
+page!(Video {
+    enable_output: bool = false,
+    device: String = String::new(),
+    output_during_playback: bool = true,
+    mirror_on_monitor: bool = true,
+    disable_when_background: bool = false,
+});
+
+page!(ThreeD {
+    /// Default 3D renderer for new compositions: `classic` or `advanced`.
+    default_renderer: String = "classic".into(),
+    show_reference_axes: bool = true,
+    extended_viewer: bool = false,
+    realtime_shadows: bool = true,
+});
+
+page!(
+    /// Settings ▸ Roto Brush.
+    RotoPrefs {
+        /// The segmentation model Roto Brush 2.0 / 3.0 use: `classical` (built in) or a model id
+        /// from `effectcraft_segment::MODELS` (once installed).
+        model: String = "classical".into(),
+    }
+);
+
+page!(
+    /// Settings ▸ Face Tracking.
+    FacePrefs {
+        /// The model Track Mask ▸ Face Tracking uses: `classical` (built in) or a model id from
+        /// `effectcraft_segment::MODELS` (once installed).
+        model: String = "classical".into(),
+    }
+);
+
+page!(Scripting {
+    allow_scripts_write_files: bool = false,
+    warn_executing_files: bool = true,
+    enable_js_debugger: bool = false,
+    editor_font_size: u32 = 13,
+    syntax_highlighting: bool = true,
+    line_numbers: bool = true,
+    auto_complete: bool = true,
+    bracket_matching: bool = true,
+    word_wrap: bool = false,
+    error_banner: bool = true,
+});
+
+impl Scripting {
+    /// Whether `other` grants scripts the same as this: Application Scripting (file and network
+    /// access, the warning before executing files, the debugger). Scripts can't change these
+    /// ([`crate::Session::execute_for_script`]): a script could otherwise give itself the
+    /// access the user withheld.
+    pub fn same_permissions(&self, other: &Scripting) -> bool {
+        self.allow_scripts_write_files == other.allow_scripts_write_files
+            && self.warn_executing_files == other.warn_executing_files
+            && self.enable_js_debugger == other.enable_js_debugger
+    }
+
+    /// Take `from`'s Application Scripting settings (see [`Scripting::same_permissions`]).
+    pub fn keep_permissions(&mut self, from: &Scripting) {
+        self.allow_scripts_write_files = from.allow_scripts_write_files;
+        self.warn_executing_files = from.warn_executing_files;
+        self.enable_js_debugger = from.enable_js_debugger;
+    }
+}
+
+/// One editable label: name and `#rrggbb` colour.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct LabelPref {
+    pub name: String,
+    pub color: String,
+}
+
+/// A Composition Settings preset the user saved (Composition Settings ▸ Preset ▸ Save): the
+/// frame size, pixel aspect and frame rate, as in After Effects' own presets.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct CompPreset {
+    pub name: String,
+    pub width: u32,
+    pub height: u32,
+    pub pixel_aspect: f64,
+    pub frame_rate: f64,
+}
+
+impl CompPreset {
+    /// Longest preset name kept.
+    pub const MAX_NAME: usize = 128;
+
+    /// Values a composition accepts (a hand-edited settings file can hold anything).
+    pub fn is_valid(&self) -> bool {
+        let size = 4..=30000;
+        !self.name.trim().is_empty()
+            && self.name.chars().count() <= Self::MAX_NAME
+            && size.contains(&self.width)
+            && size.contains(&self.height)
+            && self.pixel_aspect.is_finite()
+            && (0.01..=100.0).contains(&self.pixel_aspect)
+            && self.frame_rate.is_finite()
+            && (1.0..=999.0).contains(&self.frame_rate)
+    }
+}
+
+/// Saved composition presets, skipping entries that don't parse instead of losing the list.
+pub(super) fn lenient_comp_presets<'de, D: serde::Deserializer<'de>>(d: D) -> Result<Vec<CompPreset>, D::Error> {
+    let v = Vec::<Value>::deserialize(d)?;
+    Ok(v.into_iter().filter_map(|x| serde_json::from_value(x).ok()).collect())
+}
+
+pub(super) fn default_labels() -> Vec<LabelPref> {
+    Label::ALL.iter().skip(1).map(|l| LabelPref { name: l.name().to_string(), color: hex(l.rgb()) }).collect()
+}
+
+fn hex([r, g, b]: [u8; 3]) -> String {
+    format!("#{r:02x}{g:02x}{b:02x}")
+}
+
+pub(super) fn parse_hex(s: &str) -> Option<[u8; 3]> {
+    let h = s.trim().trim_start_matches('#');
+    if h.len() != 6 {
+        return None;
+    }
+    let p = |i: usize| u8::from_str_radix(h.get(i..i + 2)?, 16).ok();
+    Some([p(0)?, p(2)?, p(4)?])
+}
+
+impl Appearance {
+    /// Show the legacy single `theme`: fix the mode to its family and remember it as that
+    /// family's theme. An unknown theme changes nothing.
+    pub fn select_theme(&mut self) {
+        match theme_family(&self.theme) {
+            Some((mode, "darkTheme")) => {
+                self.appearance_mode = mode.into();
+                self.dark_theme = self.theme.clone();
+            }
+            Some((mode, _)) => {
+                self.appearance_mode = mode.into();
+                self.light_theme = self.theme.clone();
+            }
+            None => {}
+        }
+    }
+
+    /// The theme to show: the light or dark family's choice by the mode; Auto follows `system_light`
+    /// (`None` = the system said nothing: dark).
+    pub fn resolved_theme(&self, system_light: Option<bool>) -> &str {
+        let light = match self.appearance_mode.as_str() {
+            "light" => true,
+            "auto" => system_light == Some(true),
+            _ => false,
+        };
+        if light { &self.light_theme } else { &self.dark_theme }
+    }
+}
diff --git a/crates/engine/src/session_settings.rs b/crates/engine/src/settings/session_settings.rs
similarity index 92%
rename from crates/engine/src/session_settings.rs
rename to crates/engine/src/settings/session_settings.rs
index a56d1849b..609ad5987 100644
--- a/crates/engine/src/session_settings.rs
+++ b/crates/engine/src/settings/session_settings.rs
@@ -82,7 +82,9 @@ impl Session {
     /// Take the latest reading of the system's memory and start the next one in the background
     /// (desktop frontends call this every few seconds; it never waits for the system), then
     /// re-apply the cache budgets when the reading changes them. Returns the effective budgets.
+    /// The disk cache's free disk space is read the same way (it keeps a reserve free).
     pub fn memory_tick(&mut self) -> crate::prefs::CacheBudgets {
+        self.poll_disk_space();
         let before = self.prefs.cache_budgets(self.sys_memory);
         self.sys_memory = self.memory_watch.latest().or(self.sys_memory);
         self.memory_watch.poll();
@@ -98,6 +100,19 @@ impl Session {
         after
     }
 
+    /// Read the disk cache's free disk space in the background and apply it there (the reserve
+    /// it keeps free): the free space and the cache's size are taken at the same moment, and the
+    /// reader holds its own cache, so a reading never reaches another folder's.
+    fn poll_disk_space(&mut self) {
+        if let Some(dc) = &self.disk_cache {
+            let dc = dc.clone();
+            self.disk_watch.poll_with("ec-disk-space", move || {
+                dc.set_disk_space(crate::sysinfo::disk_space(dc.folder()));
+                Some(())
+            });
+        }
+    }
+
     /// Apply Settings ▸ Media & Disk Cache ▸ Disk Cache: open (or close) the persistent cache
     /// and attach it to the layer cache. Without a folder setting the platform cache folder is
     /// used, but only by frontends with a settings store (headless sessions stay off disk).
@@ -113,6 +128,7 @@ impl Session {
         // (no file system in the browser: the disk cache stays off there)
         let Some(folder) = folder.filter(|_| d.disk_cache_enabled && !cfg!(target_arch = "wasm32")) else {
             self.disk_cache = None;
+            self.disk_watch = Default::default();
             self.layer_cache.set_disk(None);
             return;
         };
@@ -120,23 +136,31 @@ impl Session {
         // opens a disk cache (often the platform folder, through a settings store) would take
         // over the store of a roto test running beside it. Serialise them with the roto tests.
         #[cfg(test)]
-        crate::tests_roto::hold_roto_cache_test_lock();
+        crate::tests::roto::hold_roto_cache_test_lock();
         let dc = match &self.disk_cache {
             Some(c) if c.folder() == folder.as_path() => {
                 c.set_max_bytes(max);
                 c.clone()
             }
+            // A new folder: the free-space reading was for the old one (a reader still running
+            // holds the old watcher's state, so it can't write into the new one).
             _ => match DiskCache::open(&folder, max) {
-                Ok(c) => c,
+                Ok(c) => {
+                    self.disk_watch = Default::default();
+                    c
+                }
                 Err(e) => {
                     log::warn!("disk cache at {}: {e}", folder.display());
                     self.disk_cache = None;
+                    self.disk_watch = Default::default();
                     self.layer_cache.set_disk(None);
                     return;
                 }
             },
         };
         self.disk_cache = Some(dc.clone());
+        // The reserve applies from the start (a new folder's watcher is idle).
+        self.poll_disk_space();
         let salt = self.refresh_disk_salt(true).unwrap_or_default();
         self.layer_cache.set_disk(Some((dc.clone(), salt)));
         // Roto Brush / Object Matte segmentations persist there too (held weakly: switching the
diff --git a/crates/engine/src/shortcuts.rs b/crates/engine/src/settings/shortcuts.rs
similarity index 96%
rename from crates/engine/src/shortcuts.rs
rename to crates/engine/src/settings/shortcuts.rs
index 3d4ab3661..2eb6fa680 100644
--- a/crates/engine/src/shortcuts.rs
+++ b/crates/engine/src/settings/shortcuts.rs
@@ -105,6 +105,21 @@ pub fn bindables(ui: &[UiCommand]) -> Vec<Bindable> {
             &mut out,
         );
     }
+    // File ▸ Scripts ▸ Recent Script Files lists its scripts at run time; the first one, the most
+    // recent, has a key.
+    let recent = json!({"recent": 0});
+    push(
+        Bindable {
+            key: binding_key("file.runScript", &recent),
+            command: "file.runScript".into(),
+            params: recent,
+            label: "Run Most Recent Script File".into(),
+            path: vec!["File".into(), "Scripts".into(), "Recent Script Files".into()],
+            scope: APP_SCOPE.into(),
+            defaults: normalize("Cmd+Alt+Shift+D").into_iter().collect(),
+        },
+        &mut out,
+    );
     for c in crate::command_specs() {
         if !c.journal || entries.iter().any(|(_, e)| e.command == c.id) {
             continue;
diff --git a/crates/engine/src/system.rs b/crates/engine/src/system.rs
new file mode 100644
index 000000000..d292e1232
--- /dev/null
+++ b/crates/engine/src/system.rs
@@ -0,0 +1,5 @@
+pub mod guard;
+pub mod logging;
+pub mod perf;
+pub mod storage;
+pub mod sysinfo;
diff --git a/crates/engine/src/guard.rs b/crates/engine/src/system/guard.rs
similarity index 100%
rename from crates/engine/src/guard.rs
rename to crates/engine/src/system/guard.rs
diff --git a/crates/engine/src/logging.rs b/crates/engine/src/system/logging.rs
similarity index 100%
rename from crates/engine/src/logging.rs
rename to crates/engine/src/system/logging.rs
diff --git a/crates/engine/src/perf.rs b/crates/engine/src/system/perf.rs
similarity index 100%
rename from crates/engine/src/perf.rs
rename to crates/engine/src/system/perf.rs
diff --git a/crates/engine/src/storage.rs b/crates/engine/src/system/storage.rs
similarity index 100%
rename from crates/engine/src/storage.rs
rename to crates/engine/src/system/storage.rs
diff --git a/crates/engine/src/sysinfo.rs b/crates/engine/src/system/sysinfo.rs
similarity index 60%
rename from crates/engine/src/sysinfo.rs
rename to crates/engine/src/system/sysinfo.rs
index de39974da..bfb471e92 100644
--- a/crates/engine/src/sysinfo.rs
+++ b/crates/engine/src/system/sysinfo.rs
@@ -1,11 +1,12 @@
 //! Host information for Settings ▸ Memory & CPU (RAM reserved for other applications, reducing
-//! caches when the system is low on memory) and Help ▸ System Compatibility Report.
+//! caches when the system is low on memory), the disk cache's free-space reserve and Help ▸
+//! System Compatibility Report.
 //!
 //! Pure Rust and dependency-free: the values come from the operating system's own reporting
-//! (`/proc/meminfo` on Linux, `sysctl`/`vm_stat` on macOS, `wmic`/PowerShell on Windows). Every
-//! query may fail (sandboxes, the web): callers treat `None` as "unknown" and keep their
-//! configured budgets. The periodic reading behind the cache budgets runs on a background
-//! thread ([`MemoryWatch`]): on Windows it starts PowerShell, which takes about a second.
+//! (`/proc/meminfo` on Linux, `sysctl`/`vm_stat` on macOS, `df` on Unix, `wmic`/PowerShell on
+//! Windows). Every query may fail (sandboxes, the web): callers treat `None` as "unknown" and
+//! keep their configured budgets. The periodic readings behind the cache budgets run on a
+//! background thread ([`Watch`]): on Windows they start PowerShell, which takes about a second.
 
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex, PoisonError};
@@ -27,47 +28,74 @@ impl SysMemory {
     }
 }
 
-/// The system's memory, read in the background: [`MemoryWatch::poll`] starts a reading (unless
-/// one is running) and [`MemoryWatch::latest`] returns the last one without waiting.
-#[derive(Clone, Default)]
-pub struct MemoryWatch {
-    latest: Arc<Mutex<Option<SysMemory>>>,
+/// A system value read in the background: [`Watch::poll_with`] starts a reading (unless one is
+/// running) and [`Watch::latest`] returns the last one without waiting.
+#[derive(Clone)]
+pub struct Watch<T> {
+    latest: Arc<Mutex<Option<T>>>,
     busy: Arc<AtomicBool>,
 }
 
-impl MemoryWatch {
-    /// Start a new reading in the background (no threads on the web: read inline, it is
-    /// unknown there anyway).
-    pub fn poll(&self) {
+impl<T> Default for Watch<T> {
+    fn default() -> Self {
+        Watch { latest: Arc::new(Mutex::new(None)), busy: Arc::new(AtomicBool::new(false)) }
+    }
+}
+
+/// The system's memory ([`memory`]).
+pub type MemoryWatch = Watch<SysMemory>;
+/// The disk cache's free-space reading ([`disk_space`]): the reader applies it to its cache
+/// itself, so only the busy guard is used.
+pub type DiskWatch = Watch<()>;
+
+impl<T: Copy + Send + 'static> Watch<T> {
+    /// Start a new reading in the background on a thread called `name` (no threads on the web:
+    /// read inline, it is unknown there anyway).
+    pub fn poll_with(&self, name: &str, read: impl FnOnce() -> Option<T> + Send + 'static) {
         if self.busy.swap(true, Ordering::AcqRel) {
             return;
         }
         let (latest, busy) = (self.latest.clone(), self.busy.clone());
         let read = move || {
-            if let Some(m) = memory() {
-                *latest.lock().unwrap_or_else(PoisonError::into_inner) = Some(m);
-            }
+            // A failed reading clears the last one: a stale value is worse than none.
+            *latest.lock().unwrap_or_else(PoisonError::into_inner) = read();
             busy.store(false, Ordering::Release);
         };
         #[cfg(not(target_arch = "wasm32"))]
-        if std::thread::Builder::new().name("ec-memory".into()).spawn(read).is_err() {
+        if std::thread::Builder::new().name(name.into()).spawn(read).is_err() {
             self.busy.store(false, Ordering::Release);
         }
         #[cfg(target_arch = "wasm32")]
-        read();
+        {
+            let _ = name;
+            read();
+        }
     }
 
-    /// The last reading (`None` until one finished).
-    pub fn latest(&self) -> Option<SysMemory> {
+    /// The last reading (`None` until one finished or when the last one failed).
+    pub fn latest(&self) -> Option<T> {
         *self.latest.lock().unwrap_or_else(PoisonError::into_inner)
     }
 }
 
+impl MemoryWatch {
+    /// Start a new reading of the system's memory in the background.
+    pub fn poll(&self) {
+        self.poll_with("ec-memory", memory);
+    }
+}
+
 #[cfg(not(target_arch = "wasm32"))]
 #[allow(dead_code)]
 fn run(cmd: &str, args: &[&str]) -> Option<String> {
+    run_env(cmd, args, &[])
+}
+
+#[cfg(not(target_arch = "wasm32"))]
+#[allow(dead_code)]
+fn run_env(cmd: &str, args: &[&str], env: &[(&str, &std::ffi::OsStr)]) -> Option<String> {
     let mut c = std::process::Command::new(cmd);
-    c.args(args);
+    c.args(args).envs(env.iter().copied());
     // A console program started from the windowed app would flash a console window.
     #[cfg(target_os = "windows")]
     std::os::windows::process::CommandExt::creation_flags(&mut c, 0x0800_0000); // CREATE_NO_WINDOW
@@ -139,6 +167,46 @@ pub fn memory() -> Option<SysMemory> {
     None
 }
 
+/// Parse `df -Pk` output: the disk's total and available bytes.
+pub fn parse_df(text: &str) -> Option<(u64, u64)> {
+    let line = text.lines().skip(1).find(|l| !l.trim().is_empty())?;
+    let f: Vec<&str> = line.split_whitespace().collect();
+    // A full disk into its root-reserved blocks reports negative numbers (Linux): none free.
+    let num = |v: &str| match v.strip_prefix('-') {
+        Some(d) => d.parse::<u64>().ok().map(|_| 0),
+        None => v.parse::<u64>().ok(),
+    };
+    // Size, used, available and capacity follow the device name (which may contain spaces).
+    let i = (0..f.len().saturating_sub(3))
+        .find(|&i| f.get(i + 3).is_some_and(|c| c.ends_with('%')) && f.get(i..i + 3).is_some_and(|n| n.iter().all(|v| num(v).is_some())))?;
+    let kb = |j: usize| f.get(j).and_then(|v| num(v)).map(|v| v.saturating_mul(1024));
+    Some((kb(i)?, kb(i + 2)?))
+}
+
+/// Total and available bytes of the disk holding `path`, when the system reports them.
+pub fn disk_space(path: &std::path::Path) -> Option<(u64, u64)> {
+    #[cfg(any(target_os = "linux", target_os = "macos", target_os = "freebsd"))]
+    {
+        return parse_df(&run("df", &["-Pk", &path.to_string_lossy()])?);
+    }
+    #[cfg(target_os = "windows")]
+    {
+        // The path goes through the environment: no quoting.
+        let text = run_env(
+            "powershell",
+            &["-NoProfile", "-Command", "$d=[IO.DriveInfo]::new($env:EC_DISK_PATH); \"$($d.TotalSize) $($d.AvailableFreeSpace)\""],
+            &[("EC_DISK_PATH", path.as_os_str())],
+        )?;
+        let mut it = text.split_whitespace().filter_map(|v| v.parse::<u64>().ok());
+        return Some((it.next()?, it.next()?));
+    }
+    #[allow(unreachable_code)]
+    {
+        let _ = path;
+        None
+    }
+}
+
 /// CPU model name.
 pub fn cpu_name() -> Option<String> {
     #[cfg(target_os = "linux")]
@@ -225,6 +293,42 @@ mod tests {
         assert_eq!(m.available, 1000);
     }
 
+    #[test]
+    fn a_failed_reading_clears_the_last_one() {
+        let w = Watch::<u64>::default();
+        let wait = || {
+            for _ in 0..500 {
+                if !w.busy.load(Ordering::Acquire) {
+                    return;
+                }
+                std::thread::sleep(std::time::Duration::from_millis(2));
+            }
+            panic!("the reading never finished");
+        };
+        w.poll_with("ec-test", || Some(7));
+        wait();
+        assert_eq!(w.latest(), Some(7));
+        w.poll_with("ec-test", || None);
+        wait();
+        assert_eq!(w.latest(), None);
+    }
+
+    #[test]
+    fn parses_df() {
+        let linux = "Filesystem     1024-blocks      Used Available Capacity Mounted on\n/dev/nvme0n1p2   488281250 123456789 364824461      26% /\n";
+        assert_eq!(parse_df(linux), Some((488_281_250 * 1024, 364_824_461 * 1024)));
+        // macOS: a device name with spaces and a mount point with spaces.
+        let mac = "Filesystem 1024-blocks Used Available Capacity  Mounted on\nmap auto_home 0 0 0 100% /System/Volumes/Data/home\n";
+        assert_eq!(parse_df(mac), Some((0, 0)));
+        let spaced = "Filesystem 1024-blocks Used Available Capacity Mounted on\n//nas/My Share 1000 400 600 40% /Volumes/My Share\n";
+        assert_eq!(parse_df(spaced), Some((1000 * 1024, 600 * 1024)));
+        // A full disk into its reserved blocks: nothing available.
+        let full = "Filesystem 1024-blocks Used Available Capacity Mounted on\n/dev/sda2 1000 1010 -10 101% /\n";
+        assert_eq!(parse_df(full), Some((1000 * 1024, 0)));
+        assert_eq!(parse_df("Filesystem 1024-blocks\n"), None);
+        assert_eq!(parse_df(""), None);
+    }
+
     #[test]
     fn parses_proc_meminfo_and_vm_stat() {
         let m = parse_meminfo("MemTotal:       16000000 kB\nMemFree:  1000 kB\nMemAvailable:    8000000 kB\n").unwrap();
diff --git a/crates/engine/src/tests.rs b/crates/engine/src/tests.rs
index b3f0602b3..579d3d30d 100644
--- a/crates/engine/src/tests.rs
+++ b/crates/engine/src/tests.rs
@@ -1,735 +1,53 @@
-use serde_json::json;
-
-use crate::Session;
-
-fn demo() -> Session {
-    let mut s = Session::default();
-    s.execute("file.openDemoProject", json!({})).unwrap();
-    s
-}
-
-#[test]
-fn demo_opens_and_renders() {
-    let s = demo();
-    let cid = s.active_comp_id().unwrap();
-    let img = s.render(cid, s.time(), effectcraft_render::RenderOpts { scale: 0.25, ..Default::default() });
-    assert_eq!((img.width, img.height), (480, 270));
-    let lit = img.data.iter().filter(|p| p[3] > 0.99).count();
-    assert!(lit > 100_000, "{lit}");
-}
-
-/// The session's layer cache never changes pixels: scrubbing the demo (including back and
-/// forth, and across an edit made through a command) matches cache-less renders exactly.
-#[test]
-fn demo_layer_cache_is_transparent() {
-    let mut s = demo();
-    let cid = s.active_comp_id().unwrap();
-    let opts = effectcraft_render::RenderOpts { scale: 0.25, ..Default::default() };
-    let uncached = |s: &Session, t: f64| {
-        let mut r = effectcraft_render::Renderer::new(&s.project, s.footage.as_ref(), opts);
-        r.expr = s.expr.as_deref();
-        r.comp_frame(cid, effectcraft_time::Tick::from_seconds_f64(t))
-    };
-    let check = |s: &Session, t: f64| {
-        let a = s.render(cid, effectcraft_time::Tick::from_seconds_f64(t), opts);
-        let b = uncached(s, t);
-        assert!(a.data.iter().zip(&b.data).all(|(p, q)| (0..4).all(|c| (p[c] - q[c]).abs() < 1e-6)), "t={t}");
-    };
-    for t in [0.5, 1.0, 3.0, 3.0334, 6.0, 3.0, 0.5] {
-        check(&s, t);
-    }
-    assert!(s.layer_cache.stats().hits > 0);
-    // Edit the title's glow through the command layer, then scrub again.
-    let title = s.project.comp(cid).unwrap().layers.iter().find(|l| l.name == "EFFECTCRAFT").map(|l| l.id.0).unwrap();
-    s.execute("prop.set", json!({"layer": title, "path": "effects/#1/radius", "value": 5.0})).unwrap();
-    for t in [3.0, 0.5] {
-        check(&s, t);
-    }
-}
-
-/// `layer.addItem` puts the layer at `index` (1-based) in the stack and starts it at `time`, as a
-/// drop in the Timeline does (#89).
-#[test]
-fn add_item_at_a_stack_index_and_time() {
-    let mut s = Session::default();
-    let clip = s.execute("comp.new", json!({"name": "Clip", "width": 16, "height": 16, "frameRate": 30, "duration": 1})).unwrap()["comp"].as_u64().unwrap();
-    s.execute("comp.new", json!({"name": "Main", "width": 32, "height": 32, "frameRate": 30, "duration": 4})).unwrap();
-    for name in ["C", "B", "A"] {
-        s.execute("layer.newSolid", json!({"name": name})).unwrap();
-    }
-    let names = |s: &Session| s.active_comp().unwrap().layers.iter().map(|l| l.name.clone()).collect::<Vec<_>>();
-    s.execute("layer.addItem", json!({"item": clip, "index": 2, "time": 1.01})).unwrap();
-    assert_eq!(names(&s), ["A", "Clip", "B", "C"]);
-    let l = &s.active_comp().unwrap().layers[1];
-    assert_eq!(l.in_point, effectcraft_time::Tick::from_seconds_f64(1.0), "on the nearest frame");
-    // Past the bottom: the bottom.
-    s.execute("layer.addItem", json!({"item": clip, "index": 99})).unwrap();
-    assert_eq!(names(&s).last().map(String::as_str), Some("Clip 2"));
-    assert!(s.execute("layer.addItem", json!({"item": clip, "index": 0})).is_err(), "1-based");
-}
-
-/// Files dropped on the Timeline or the Composition viewer (`file.import {addToComp}`) become
-/// layers of the comp that was active, one under the other, where they were dropped (#85, #89).
-#[test]
-fn imported_files_go_into_the_comp_where_they_were_dropped() {
-    use effectcraft_project::{Footage, FootageKind};
-    struct Probe;
-    impl crate::Importer for Probe {
-        fn probe(&self, path: &str) -> Result<Footage, String> {
-            Ok(Footage { path: path.into(), kind: FootageKind::Still, width: 64, height: 32, has_video: true, ..Default::default() })
-        }
-    }
-    let mut s = Session { importer: Some(std::sync::Arc::new(Probe)), ..Default::default() };
-    s.execute("comp.new", json!({"name": "Main", "width": 320, "height": 180, "frameRate": 30, "duration": 4})).unwrap();
-    s.execute("layer.newSolid", json!({"name": "Bg"})).unwrap();
-    let params = json!({"paths": ["/drop/a.png", "/drop/b.png"], "addToComp": true, "position": [40.0, 50.0], "index": 1, "time": 1.0});
-    s.execute("file.import", params).unwrap();
-    let comp = s.active_comp().unwrap();
-    assert_eq!(comp.layers.iter().map(|l| l.name.as_str()).collect::<Vec<_>>(), ["a.png", "b.png", "Bg"]);
-    for l in &comp.layers[..2] {
-        assert_eq!(l.props.prop("transform/position").map(|p| p.value.clone()), Some(effectcraft_keyframe::Value::Vec3([40.0, 50.0, 0.0])));
-        assert_eq!(l.in_point, effectcraft_time::Tick::from_seconds_f64(1.0));
-    }
-    // Without `addToComp` they only import.
-    s.execute("file.import", json!({"paths": ["/drop/c.png"]})).unwrap();
-    assert_eq!(s.active_comp().unwrap().layers.len(), 3);
-    assert!(s.execute("layer.addItem", json!({"item": "a.png", "position": [1.0]})).is_err(), "position needs x and y");
-}
-
-/// #270: files dropped or picked in the Import dialog (`file.import {background}`) are probed in
-/// a background job that says which file it is reading and how many are left; then they arrive
-/// in one undo step, all selected, with a count. The same file imported again arrives again.
-#[test]
-fn background_imports_report_progress_and_select_what_arrived() {
-    use effectcraft_project::{Footage, FootageKind, ItemId};
-    use std::sync::Arc;
-    use std::sync::atomic::{AtomicUsize, Ordering};
-    /// Probes file k once `allow` > k (a slow video; 5 s at most, so an import that waits for it
-    /// fails the test instead of hanging it); `.xyz` files fail.
-    struct Gated {
-        started: AtomicUsize,
-        allow: Arc<AtomicUsize>,
-    }
-    impl crate::Importer for Gated {
-        fn probe(&self, path: &str) -> Result<Footage, String> {
-            let k = self.started.fetch_add(1, Ordering::SeqCst);
-            let until = std::time::Instant::now() + std::time::Duration::from_secs(5);
-            while self.allow.load(Ordering::SeqCst) <= k && std::time::Instant::now() < until {
-                std::thread::sleep(std::time::Duration::from_millis(1));
-            }
-            if path.ends_with(".xyz") {
-                return Err("unsupported file".into());
-            }
-            Ok(Footage { path: path.into(), kind: FootageKind::Still, width: 64, height: 32, has_video: true, ..Default::default() })
-        }
-    }
-    let allow = Arc::new(AtomicUsize::new(1));
-    let mut s = Session { importer: Some(Arc::new(Gated { started: AtomicUsize::new(0), allow: allow.clone() })), ..Default::default() };
-    s.execute("comp.new", json!({"name": "Main", "width": 320, "height": 180, "frameRate": 30, "duration": 4})).unwrap();
-    let undo = s.history.undo.len();
-    let r = s.execute("file.import", json!({"paths": ["/drop/a.png", "/drop/b.png", "/drop/a.png"], "background": true})).unwrap();
-    let job = r["job"].as_str().unwrap().to_string();
-    // The first file is through; the second is being read.
-    let running = |s: &mut Session| s.execute("jobs.list", json!({})).unwrap()["running"].as_array().unwrap().clone();
-    let deadline = std::time::Instant::now() + std::time::Duration::from_secs(10);
-    while running(&mut s)[0]["done"] != json!(1) && std::time::Instant::now() < deadline {
-        std::thread::sleep(std::time::Duration::from_millis(2));
-    }
-    let row = running(&mut s)[0].clone();
-    assert_eq!(row["id"], json!(job));
-    assert_eq!(row["label"], json!("Importing 3 files"));
-    assert_eq!(row["message"], json!("b.png (2 of 3)"));
-    assert_eq!((row["done"].as_u64(), row["total"].as_u64()), (Some(1), Some(3)));
-    assert!(s.project.items.values().all(|i| i.name != "a.png"), "nothing is added before the import finishes");
-    allow.store(usize::MAX, Ordering::SeqCst);
-    s.execute("jobs.wait", json!({})).unwrap();
-    let names = |s: &Session, ids: &[ItemId]| ids.iter().map(|i| s.project.item(*i).unwrap().name.clone()).collect::<Vec<_>>();
-    assert_eq!(names(&s, &s.state.project_selection), ["a.png", "b.png", "a.png"], "everything imported is selected, the same file twice too");
-    assert_eq!(s.history.undo.len(), undo + 1, "one undo step");
-    let rec = s.job_log.last().unwrap();
-    assert_eq!((rec.status.as_str(), rec.message.as_str()), ("done", "Imported 3 items"));
-    assert!(s.drain_events().iter().any(|e| matches!(e, crate::Event::Toast { message, .. } if message == "Imported 3 items")));
-    // Dropped on the viewer: they become layers too; a file that can't be read is reported.
-    s.execute("file.import", json!({"paths": ["/drop/c.png", "/drop/d.xyz"], "background": true, "addToComp": true, "position": [10.0, 20.0]})).unwrap();
-    s.execute("jobs.wait", json!({})).unwrap();
-    assert_eq!(s.active_comp().unwrap().layers.iter().map(|l| l.name.as_str()).collect::<Vec<_>>(), ["c.png"]);
-    assert_eq!(s.job_log.last().unwrap().message, "Imported 1 item. /drop/d.xyz: unsupported file");
-    // Agents and scripts import at once by default.
-    let r = s.execute("file.import", json!({"paths": ["/drop/e.png"]})).unwrap();
-    assert_eq!(r["items"].as_array().map(Vec::len), Some(1));
-}
-
-/// Audio, Lock and Shy don't change pixels: toggling them keeps the cached layers (#103).
-#[test]
-fn audio_lock_and_shy_keep_cached_layers() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"name": "C", "width": 160, "height": 90, "frameRate": 30, "duration": 1})).unwrap();
-    s.execute("layer.newSolid", json!({"color": "#3080ff", "width": 80, "height": 40})).unwrap();
-    s.execute("effect.apply", json!({"layer": "#1", "effect": "Gaussian Blur"})).unwrap();
-    s.execute("prop.set", json!({"layer": "#1", "path": "effects/#1/blurriness", "value": 12})).unwrap();
-    let cid = s.active_comp_id().unwrap();
-    let t = s.time();
-    s.render(cid, t, Default::default());
-    let before = s.layer_cache.stats();
-    for sw in ["audio", "lock", "shy"] {
-        s.execute("layer.setSwitch", json!({"layers": ["#1"], "switch": sw, "value": sw != "audio"})).unwrap();
-    }
-    s.render(cid, t, Default::default());
-    let after = s.layer_cache.stats();
-    assert_eq!(after.misses, before.misses, "no layer rendered again");
-    assert!(after.hits > before.hits);
-}
-
-#[test]
-fn every_command_has_unique_id_and_runs_or_reports() {
-    let mut ids = std::collections::HashSet::new();
-    for c in crate::command_specs() {
-        assert!(ids.insert(c.id), "duplicate {}", c.id);
-    }
-    assert!(ids.len() >= 90, "{}", ids.len());
-}
-
-#[test]
-fn layer_workflow_with_undo() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"name": "Test", "width": 640, "height": 360, "frameRate": 30, "duration": 4})).unwrap();
-    let r = s.execute("layer.newSolid", json!({"color": "#336699"})).unwrap();
-    let lid = r["layer"].as_u64().unwrap();
-    s.execute("prop.set", json!({"layer": lid, "path": "transform/opacity", "value": 50})).unwrap();
-    let tree = s.execute("layer.tree", json!({"layer": lid})).unwrap();
-    assert!(tree.to_string().contains("\"value\":50.0"));
-    s.execute("prop.toggleAnimation", json!({"layer": lid, "path": "transform/position"})).unwrap();
-    s.execute("time.set", json!({"time": 2.0})).unwrap();
-    s.execute("prop.set", json!({"layer": lid, "path": "transform/position", "value": [100, 100]})).unwrap();
-    let comp = s.active_comp().unwrap();
-    let pos = comp.layers[0].props.prop("transform/position").unwrap();
-    assert_eq!(pos.keys.len(), 2);
-    s.execute("prop.select", json!({"layer": lid, "path": "transform/position"})).unwrap();
-    assert_eq!(s.state.selected_keys.len(), 2);
-    s.execute("keys.easyEase", json!({})).unwrap();
-    s.execute("keys.move", json!({"delta": 0.5})).unwrap();
-    let pos = s.active_comp().unwrap().layers[0].props.prop("transform/position").unwrap().clone();
-    assert!((pos.keys[0].time.seconds() - 0.5).abs() < 0.02);
-    assert_eq!(pos.keys[0].out_interp, effectcraft_keyframe::Interp::Bezier);
-    // undo back to before the move
-    s.execute("edit.undo", json!({})).unwrap();
-    let pos = s.active_comp().unwrap().layers[0].props.prop("transform/position").unwrap().clone();
-    assert!(pos.keys[0].time.seconds().abs() < 0.02);
-    s.execute("effect.apply", json!({"layer": lid, "effect": "Gaussian Blur"})).unwrap();
-    s.execute("prop.set", json!({"layer": lid, "path": "effects/#1/blurriness", "value": 12})).unwrap();
-    // Applying selects the new effect (Edit ▸ Duplicate would duplicate it); select the layer.
-    s.execute("layer.select", json!({"layers": [lid]})).unwrap();
-    s.execute("edit.duplicate", json!({})).unwrap();
-    assert_eq!(s.active_comp().unwrap().layers.len(), 2);
-    s.execute("layer.precompose", json!({"layers": [1, 2], "name": "Pre"})).unwrap();
-    assert_eq!(s.active_comp().unwrap().layers.len(), 1);
-}
-
-#[test]
-fn text_shape_mask_matte_parent() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"width": 800, "height": 450, "duration": 3})).unwrap();
-    let t = s.execute("layer.newText", json!({"text": "Hello", "size": 90})).unwrap()["layer"].as_u64().unwrap();
-    s.execute("layer.addTextAnimator", json!({"layer": t, "properties": ["position", "opacity"]})).unwrap();
-    let sh = s.execute("layer.newShape", json!({"kind": "star", "fill": "#ffcc00"})).unwrap()["layer"].as_u64().unwrap();
-    s.execute("layer.addShapeItem", json!({"layer": sh, "kind": "trim"})).unwrap();
-    s.execute("layer.addMask", json!({"layer": sh, "shape": "ellipse"})).unwrap();
-    s.execute("layer.setMask", json!({"layer": sh, "mask": 1, "mode": "Subtract", "inverted": true})).unwrap();
-    s.execute("layer.setTrackMatte", json!({"layer": sh, "matte": t, "kind": "luma"})).unwrap();
-    s.execute("layer.setParent", json!({"layers": [sh], "parent": t})).unwrap();
-    assert!(s.execute("layer.setParent", json!({"layers": [t], "parent": sh})).is_err());
-    s.execute("layer.setBlendMode", json!({"layers": [sh], "mode": "Screen"})).unwrap();
-    s.execute("layer.setSwitch", json!({"layers": [sh], "switch": "threeD"})).unwrap();
-    let cid = s.active_comp_id().unwrap();
-    let _ = s.render(cid, s.time(), Default::default());
-    let info = s.execute("comp.info", json!({})).unwrap();
-    assert_eq!(info["layers"].as_array().unwrap().len(), 2);
-}
-
-/// The toolbar's Fill / Stroke change a selected shape layer's paint (#205): a shape drawn
-/// without a stroke gets one, later edits change it, and the Contents "Add:" items (#206) include
-/// an empty Path and a Gradient Stroke that render.
-#[test]
-fn toolbar_fill_and_stroke_paint_selected_shape_layers() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"width": 400, "height": 300, "duration": 2})).unwrap();
-    let sh = s.execute("layer.newShape", json!({"kind": "rect", "fill": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
-    let paint = |s: &mut Session| s.execute("shape.fillStroke", json!({})).unwrap();
-    assert_eq!(paint(&mut s)["stroke"], serde_json::Value::Null, "drawn without a stroke");
-    s.execute("shape.fillStroke", json!({"stroke": "#00ff00", "strokeWidth": 6})).unwrap();
-    let p = paint(&mut s);
-    assert_eq!((p["stroke"][1].as_f64(), p["strokeWidth"].as_f64()), (Some(1.0), Some(6.0)), "{p}");
-    s.execute("shape.fillStroke", json!({"fill": "#0000ff", "strokeWidth": 3})).unwrap();
-    let p = paint(&mut s);
-    assert_eq!((p["fill"][2].as_f64(), p["strokeWidth"].as_f64()), (Some(1.0), Some(3.0)), "{p}");
-    // One stroke, before the fill (paths, stroke, fill), and each change is one undo step.
-    let l = s.active_comp().unwrap().layer(effectcraft_project::LayerId(sh)).unwrap().clone();
-    let group = l.props.group("contents/group").unwrap();
-    let order: Vec<&str> = group.sub("contents").unwrap().groups().map(|g| g.match_id.as_str()).collect();
-    assert_eq!(order, ["rect", "stroke", "fill"]);
-    s.execute("edit.undo", json!({})).unwrap();
-    assert_eq!(paint(&mut s)["strokeWidth"].as_f64(), Some(6.0));
-    // Only shape layers.
-    s.execute("layer.newSolid", json!({"color": "#808080"})).unwrap();
-    assert!(s.execute("shape.fillStroke", json!({"fill": "#ffffff"})).is_err());
-    for kind in ["path", "gstroke"] {
-        let r = s.execute("layer.addShapeItem", json!({"layer": sh, "kind": kind})).unwrap();
-        assert!(r["path"].as_str().is_some_and(|p| p.starts_with("contents/")), "{r}");
-    }
-    let cid = s.active_comp_id().unwrap();
-    let _ = s.render(cid, s.time(), Default::default());
-}
-
-/// The toolbar's Fill Options / Stroke Options change a selected shape layer's paint kind (#732):
-/// None switches the fill off, a gradient turns the Fill into a Gradient Fill that keeps its
-/// opacity, Solid Color turns it back, and a Stroke kind adds a stroke where there is none.
-#[test]
-fn toolbar_fill_and_stroke_kinds_change_selected_shape_layers() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"width": 400, "height": 300, "duration": 2})).unwrap();
-    let sh = s.execute("layer.newShape", json!({"kind": "rect", "fill": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
-    let items = |s: &Session| -> Vec<(String, bool)> {
-        let l = s.active_comp().unwrap().layer(effectcraft_project::LayerId(sh)).unwrap();
-        l.props.group("contents/group/contents").unwrap().groups().map(|g| (g.match_id.clone(), g.enabled)).collect()
-    };
-    let kinds = |s: &mut Session| {
-        let p = s.execute("shape.fillStroke", json!({})).unwrap();
-        (p["fillType"].as_str().unwrap().to_string(), p["strokeType"].as_str().unwrap().to_string())
-    };
-    assert_eq!(kinds(&mut s), ("solid".into(), "none".into()));
-    let cid = s.active_comp_id().unwrap();
-    let centre = |s: &Session| s.render(cid, s.time(), Default::default()).get(200, 150);
-    let red = centre(&s);
-    // None switches the fill off: nothing is drawn, and the item stays.
-    s.execute("shape.fillStroke", json!({"fillType": "none"})).unwrap();
-    assert_eq!(items(&s), [("rect".into(), true), ("fill".into(), false)]);
-    assert_eq!(kinds(&mut s).0, "none");
-    assert_ne!(centre(&s), red, "the fill is off");
-    // A radial gradient: the Fill becomes a Gradient Fill (switched on) that keeps its opacity.
-    s.execute("shape.fillStroke", json!({"fillType": "solid", "fill": "#ff0000"})).unwrap();
-    assert_eq!(centre(&s), red);
-    let opacity = |s: &Session, m: &str| {
-        let l = s.active_comp().unwrap().layer(effectcraft_project::LayerId(sh)).unwrap();
-        l.props.group(&format!("contents/group/contents/{m}")).unwrap().get("opacity").unwrap().value.as_f64()
-    };
-    s.execute("prop.set", json!({"layer": sh, "path": "contents/group/contents/fill/opacity", "value": 40})).unwrap();
-    s.execute("shape.fillStroke", json!({"fillType": "radial"})).unwrap();
-    assert_eq!(items(&s), [("rect".into(), true), ("gfill".into(), true)]);
-    assert_eq!((kinds(&mut s).0.as_str(), opacity(&s, "gfill")), ("radial", 40.0));
-    s.execute("shape.fillStroke", json!({"fillType": "linear"})).unwrap();
-    assert_eq!(kinds(&mut s).0, "linear");
-    s.execute("shape.fillStroke", json!({"fillType": "solid", "fill": "#00ff00"})).unwrap();
-    assert_eq!(items(&s), [("rect".into(), true), ("fill".into(), true)]);
-    assert_eq!(opacity(&s, "fill"), 40.0);
-    // A Stroke kind adds a stroke (before the fill); None switches it off again; undo is per step.
-    s.execute("shape.fillStroke", json!({"strokeType": "linear"})).unwrap();
-    assert_eq!(items(&s), [("rect".into(), true), ("gstroke".into(), true), ("fill".into(), true)]);
-    s.execute("shape.fillStroke", json!({"strokeType": "none"})).unwrap();
-    assert_eq!(kinds(&mut s), ("solid".into(), "none".into()));
-    s.execute("edit.undo", json!({})).unwrap();
-    assert_eq!(kinds(&mut s), ("solid".into(), "linear".into()));
-    assert!(s.execute("shape.fillStroke", json!({"fillType": "plaid"})).is_err());
-}
-
-/// Selecting a mask in the Timeline (its row or its Mask Path) selects all of its points, so the
-/// viewer drags the whole mask (#203); a shape's Path item works the same way.
-#[test]
-fn selecting_a_mask_selects_its_points() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"width": 400, "height": 300, "duration": 2})).unwrap();
-    let l = s.execute("layer.newSolid", json!({"color": "#808080"})).unwrap()["layer"].as_u64().unwrap();
-    let m1 = s.execute("layer.addMask", json!({"layer": l, "shape": "rect"})).unwrap()["mask"].as_u64().unwrap();
-    let m2 = s.execute("layer.addMask", json!({"layer": l, "shape": "ellipse"})).unwrap()["mask"].as_u64().unwrap();
-    let points = |s: &Session, m: u64| s.state.selected_vertices.iter().filter(|v| v.mask == m).count();
-    s.execute("prop.select", json!({"layer": l, "prop": m1, "selectKeys": false})).unwrap();
-    assert_eq!((points(&s, m1), s.state.selected_vertices.len()), (4, 4));
-    // Mask Path selects them too; Shift-adding another mask keeps the first.
-    let path = s.active_comp().unwrap().layer(effectcraft_project::LayerId(l)).unwrap().props.find_group(m2).unwrap().get("path").unwrap().uid;
-    s.execute("prop.select", json!({"layer": l, "prop": path, "add": true})).unwrap();
-    assert_eq!((points(&s, m1), points(&s, m2)), (4, 4));
-    // Another mask replaces them; another property deselects them.
-    s.execute("prop.select", json!({"layer": l, "prop": m2})).unwrap();
-    assert_eq!((points(&s, m1), points(&s, m2)), (0, 4));
-    // Delete removes the selected mask (not only its points).
-    s.execute("edit.clear", json!({})).unwrap();
-    let masks = |s: &Session| s.active_comp().unwrap().layer(effectcraft_project::LayerId(l)).unwrap().masks().unwrap().children.len();
-    assert_eq!(masks(&s), 1);
-    s.execute("prop.select", json!({"layer": l, "path": "transform/opacity"})).unwrap();
-    assert!(s.state.selected_vertices.is_empty());
-    let sh = s.execute("layer.newShape", json!({"kind": "star"})).unwrap()["layer"].as_u64().unwrap();
-    let star = s.execute("layer.addShapeItem", json!({"layer": sh, "kind": "path"})).unwrap()["uid"].as_u64().unwrap();
-    s.execute("prop.select", json!({"layer": sh, "prop": star})).unwrap();
-    assert_eq!(s.state.selected_vertices.len(), 0, "an empty Path has no points");
-}
-
-#[test]
-fn save_and_open_roundtrip() {
-    let mut s = demo();
-    let dir = std::env::temp_dir().join(format!("ec-test-{}", std::process::id()));
-    std::fs::create_dir_all(&dir).unwrap();
-    let path = dir.join("demo.ecproj").to_string_lossy().to_string();
-    s.execute("file.saveAs", json!({"path": path})).unwrap();
-    let before = s.project.clone();
-    let mut s2 = Session::default();
-    s2.execute("file.open", json!({"path": path})).unwrap();
-    assert_eq!(*before, *s2.project);
-    let _ = std::fs::remove_dir_all(dir);
-}
-
-#[test]
-fn help_links_emit_urls() {
-    let mut s = Session::default();
-    let r = s.execute("help.discord", json!({})).unwrap();
-    assert_eq!(r["url"], "https://discord.gg/artcraft");
-    assert!(s.drain_events().iter().any(|e| matches!(e, crate::Event::OpenUrl(u) if u.contains("discord"))));
-    assert_eq!(s.execute("help.github", json!({})).unwrap()["url"], "https://github.com/storytold/effectcraft");
-}
-
-#[test]
-fn time_navigation() {
-    let mut s = demo();
-    s.execute("time.start", json!({})).unwrap();
-    let r = s.execute("time.nextKey", json!({})).unwrap();
-    assert!(r["time"].as_f64().unwrap() > 0.0);
-    s.execute("time.set", json!({"frame": 45})).unwrap();
-    assert_eq!(s.execute("time.step", json!({"frames": 5})).unwrap()["frame"], 50);
-}
-
-#[test]
-fn time_navigation_per_property() {
-    let mut s = demo();
-    // An animated property and the comp times of its keys.
-    let comp = s.active_comp().unwrap().clone();
-    let mut found = None;
-    for l in &comp.layers {
-        l.props.walk("", &mut |_, pr| {
-            if found.is_none() && pr.keys.len() >= 2 {
-                found = Some((pr.uid, pr.keys.iter().map(|k| l.comp_time(k.time)).collect::<Vec<_>>()));
-            }
-        });
-    }
-    let (uid, times) = found.expect("demo has an animated property");
-    s.set_time(effectcraft_time::Tick::ZERO);
-    let half = comp.frame_duration().0 / 2;
-    let expect = times.iter().copied().filter(|t| t.0 > half).min().unwrap();
-    s.execute("time.go", json!({"to": "nextKey", "prop": uid})).unwrap();
-    let snap = |t| comp.frame_rate.snap(t);
-    assert_eq!(s.time(), snap(expect));
-    // Going back from past the last key lands on the last key.
-    s.set_time(comp.duration);
-    s.execute("time.go", json!({"to": "prevKey", "prop": uid})).unwrap();
-    assert_eq!(s.time(), snap(*times.iter().max().unwrap()));
-}
-
-#[test]
-fn set_text_paragraph_fill_and_leading() {
-    use effectcraft_keyframe::{Justify, Value as KValue};
-    let mut s = demo();
-    let t = s.execute("layer.newText", json!({"text": "Hi"})).unwrap()["layer"].as_u64().unwrap();
-    let doc = |s: &Session| {
-        let l = s.active_comp().unwrap().layer(crate::project::LayerId(t)).unwrap().clone();
-        match &l.props.prop("text/sourceText").unwrap().value {
-            KValue::Text(d) => (**d).clone(),
-            v => panic!("{v:?}"),
-        }
-    };
-    for (key, j) in [
-        ("justifyLeft", Justify::JustifyLastLeft),
-        ("justifyCenter", Justify::JustifyLastCenter),
-        ("justifyRight", Justify::JustifyLastRight),
-        ("justifyAll", Justify::JustifyAll),
-        ("center", Justify::Center),
-    ] {
-        s.execute("layer.setText", json!({"layer": t, "justify": key})).unwrap();
-        assert_eq!(doc(&s).justify, j, "{key}");
-    }
-    s.execute("layer.setText", json!({"layer": t, "leading": 50, "applyFill": false, "applyStroke": true})).unwrap();
-    let d = doc(&s);
-    assert_eq!((d.leading, d.apply_fill, d.apply_stroke), (Some(50.0), false, true));
-    s.execute("layer.setText", json!({"layer": t, "leading": "auto"})).unwrap();
-    assert_eq!(doc(&s).leading, None);
-    s.execute("layer.setText", json!({"layer": t, "hScale": 120, "vScale": 80, "baselineShift": 4, "smallCaps": true, "strokeOverFill": true})).unwrap();
-    let d = doc(&s);
-    assert_eq!((d.h_scale, d.v_scale, d.baseline_shift, d.small_caps, d.stroke_over_fill), (120.0, 80.0, 4.0, true, true));
-}
-
-#[test]
-fn property_groups_report_actionable_errors() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"name": "T"})).unwrap();
-    let l = s.execute("layer.newText", json!({"text": "Hi"})).unwrap()["layer"].as_u64().unwrap();
-    let uid = s.active_comp().unwrap().layer(crate::project::LayerId(l)).unwrap().props.group("text/pathOptions").unwrap().uid;
-    for selector in [json!({"path": "text"}), json!({"path": "text/pathOptions"}), json!({"path": format!("@{uid}")}), json!({"prop": uid})] {
-        let mut params = selector;
-        params["layer"] = json!(l);
-        for cmd in ["prop.get", "prop.set"] {
-            let err = s.execute(cmd, params.clone()).unwrap_err().to_string();
-            assert!(err.contains("is a property group"), "{cmd}: {err}");
-            assert!(err.contains("get_layer"), "{cmd}: {err}");
-        }
-    }
-    assert!(s.execute("prop.get", json!({"layer": l, "path": "text/sourceText"})).is_ok());
-    let err = s.execute("prop.get", json!({"layer": l, "path": "missing"})).unwrap_err().to_string();
-    assert!(err.contains("no property `missing`"), "{err}");
-}
-
-#[test]
-fn prop_get_and_render_rgba8() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"name": "T", "width": 320, "height": 180, "duration": 2.0, "frameRate": 30})).unwrap();
-    let l = s.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
-    s.execute("prop.addKey", json!({"layer": l, "path": "transform/position", "time": 0.0, "value": [0, 0]})).unwrap();
-    s.execute("prop.addKey", json!({"layer": l, "path": "transform/position", "time": 1.0, "value": [100, 50]})).unwrap();
-    let v = s.execute("prop.get", json!({"layer": l, "path": "transform/position", "time": 1.0})).unwrap();
-    assert_eq!(v["animated"], true);
-    assert_eq!(v["keys"].as_array().unwrap().len(), 2);
-    assert_eq!(v["value"][0].as_f64().unwrap(), 100.0);
-    let cid = s.resolve_comp(Some(&json!("T"))).unwrap();
-    let (w, h, rgba) = s.render_rgba8(cid, effectcraft_time::Tick::ZERO, 160).unwrap();
-    assert_eq!((w, h), (160, 90));
-    assert_eq!(rgba.len(), (w * h * 4) as usize);
-}
-
-#[test]
-fn params_docs_parse() {
-    use crate::commands::accepted_params;
-    let k = |d: &str| accepted_params(d).unwrap();
-    assert_eq!(k("{layers: [id|name|#n], add?, toggle?}"), ["layers", "add", "toggle"]);
-    assert_eq!(k("{time? (s) | frame? | timecode?}"), ["time", "frame", "timecode"]);
-    assert_eq!(k("{interpolation?|in?|out?: linear|bezier|hold, autoBezier?}"), ["interpolation", "in", "out", "autoBezier"]);
-    assert_eq!(k("{keys: [{layer, prop, time}], add?}"), ["keys", "add"]);
-    assert_eq!(k("{label: Red|Yellow|Aqua|…, layers?}"), ["label", "layers"]);
-    assert_eq!(k("{name?, background? [r,g,b]|#hex, open?}"), ["name", "background", "open"]);
-    assert!(k("{}").is_empty());
-    assert!(accepted_params("free text").is_none());
-    // Every registered command documents its params as a parseable key list.
-    for c in crate::command_specs() {
-        assert!(accepted_params(c.params).is_some(), "{}: {}", c.id, c.params);
-    }
-}
-
-#[test]
-fn execute_checked_rejects_unknown_params() {
-    let mut s = demo();
-    let e = s.execute_checked("layer.select", json!({"index": 2})).unwrap_err().to_string();
-    assert!(e.contains("`index`") && e.contains("layers, add, toggle"), "{e}");
-    s.execute_checked("layer.select", json!({"layers": ["#2"]})).unwrap();
-    assert_eq!(s.state.selected_layers.len(), 1);
-    // Aliases and always-accepted keys.
-    s.execute_checked("layer.select", json!({"layer": "#1", "comp": s.active_comp_id().unwrap().0})).unwrap();
-    s.execute_checked("time.set", json!({"frame": 3})).unwrap();
-    assert!(s.execute_checked("edit.undo", json!({"steps": 2})).is_err());
-    // Non-object params are not validated; the unchecked path stays lenient.
-    s.execute("layer.select", json!({"layers": ["#1"], "index": 2})).unwrap();
-}
-
-#[test]
-fn layer_tree_paths_resolve() {
-    let mut s = demo();
-    s.execute("effect.apply", json!({"layer": 1, "effect": "Gaussian Blur"})).unwrap();
-    let comp = s.execute("comp.info", json!({})).unwrap();
-    let mut checked = 0;
-    for l in comp["layers"].as_array().unwrap() {
-        let tree = s.execute("layer.tree", json!({"layer": l["id"]})).unwrap();
-        let mut stack = vec![tree["properties"].clone()];
-        while let Some(n) = stack.pop() {
-            if let Some(ch) = n["children"].as_array() {
-                stack.extend(ch.iter().cloned());
-                continue;
-            }
-            let path = n["path"].as_str().unwrap();
-            let got = s.execute("prop.get", json!({"layer": l["id"], "path": path})).unwrap();
-            assert_eq!(got["uid"], n["uid"], "path {path} on layer {}", l["name"]);
-            checked += 1;
-        }
-    }
-    assert!(checked > 20, "{checked}");
-}
-
-#[test]
-fn comp_settings_anchor_start_timecode_renderer() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"name": "A", "width": 100, "height": 100, "duration": 2.0})).unwrap();
-    let l = s.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
-    s.execute("prop.addKey", json!({"layer": l, "path": "transform/position", "time": 0.0, "value": [10, 20]})).unwrap();
-    let pos = |s: &Session| {
-        let pr = s.active_comp().unwrap().layer(crate::project::LayerId(l)).unwrap().props.prop("transform/position").unwrap().clone();
-        pr.keys[0].value.components()
-    };
-    // Center anchor: grow by 100x50 → shift by half.
-    s.execute("comp.settings", json!({"width": 200, "height": 150})).unwrap();
-    assert_eq!(pos(&s)[..2], [60.0, 45.0]);
-    // Top-left anchor: no shift. Bottom-right: full shift.
-    s.execute("comp.settings", json!({"width": 300, "anchor": 0})).unwrap();
-    assert_eq!(pos(&s)[..2], [60.0, 45.0]);
-    s.execute("comp.settings", json!({"width": 200, "height": 100, "anchor": 8})).unwrap();
-    assert_eq!(pos(&s)[..2], [-40.0, -5.0]);
-    s.execute("comp.settings", json!({"startTimecode": "0:00:01:00", "renderer": "advanced3D"})).unwrap();
-    let c = s.active_comp().unwrap();
-    assert_eq!(c.display_start, c.frame_rate.tick_of(30));
-    assert_eq!(c.renderer, crate::project::Renderer::Advanced3D);
-}
-
-/// `advanced3D` is a value of `renderer`, not a key: comp.new / comp.settings don't advertise it
-/// in their schemas and reject it as unknown instead of ignoring it (#177).
-#[test]
-fn renderer_values_are_not_parameter_keys() {
-    let mut s = Session::default();
-    for (id, p) in [("comp.new", json!({"name": "A"})), ("comp.settings", json!({}))] {
-        let spec = crate::command_specs().iter().find(|c| c.id == id).unwrap();
-        let keys = crate::commands::accepted_params(spec.params).unwrap();
-        assert!(keys.contains(&"renderer".to_string()) && !keys.contains(&"advanced3D".to_string()), "{id}: {keys:?}");
-        let mut bad = p.clone();
-        bad["advanced3D"] = json!(true);
-        let e = s.execute_checked(id, bad).unwrap_err().to_string();
-        assert!(e.contains("unknown parameter(s) `advanced3D`"), "{id}: {e}");
-        let mut good = p;
-        good["renderer"] = json!("advanced3D");
-        s.execute_checked(id, good).unwrap();
-        assert_eq!(s.active_comp().unwrap().renderer, crate::project::Renderer::Advanced3D, "{id}");
-        s.execute("comp.renderer", json!({"renderer": "classic3d"})).unwrap();
-    }
-}
-
-#[test]
-fn comp_rejects_zero_and_negative_frame_rates() {
-    let mut s = Session::default();
-    for fps in [0.0, -30.0, 0.0001] {
-        assert!(s.execute("comp.new", json!({"frameRate": fps})).is_err(), "{fps}");
-    }
-    s.execute("comp.new", json!({"frameRate": 30, "duration": 1})).unwrap();
-    assert!(s.execute("comp.settings", json!({"frameRate": 0})).is_err());
-    assert_eq!(s.active_comp().unwrap().frame_rate, crate::time::FrameRate::FPS_30);
-}
-
-#[test]
-fn render_queue_add_accepts_documented_settings_when_checked() {
-    let mut s = demo();
-    let r = s.execute_checked(
-        "renderQueue.add",
-        json!({"format": "gif", "output": "/tmp/x.gif", "resolution": "quarter", "timeSpan": "custom", "start": 0.0, "end": 0.5, "quality": "draft", "loop": true}),
-    );
-    // Without an exporter the add itself still succeeds (rendering is what needs one).
-    assert!(r.is_ok(), "{r:?}");
-    assert!(s.execute_checked("renderQueue.add", json!({"bogus": 1})).is_err());
-}
-
-#[test]
-fn new_text_rejects_malformed_positions_without_creating_a_layer() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"name": "C", "width": 64, "height": 64, "duration": 1})).unwrap();
-    for position in [json!([]), json!([10]), json!(["x", 20]), json!([null, 20])] {
-        let err = s.execute("layer.newText", json!({"text": "Hello", "position": position})).unwrap_err();
-        assert!(err.to_string().contains("position: [x, y]"), "{err}");
-        assert!(s.active_comp().unwrap().layers.is_empty());
-    }
-    s.execute("layer.newText", json!({"name": "Valid", "text": "Hello", "position": [10, 20]})).unwrap();
-    assert_eq!(s.active_comp().unwrap().layers[0].props.prop("transform/position").unwrap().value, effectcraft_keyframe::Value::Vec3([10.0, 20.0, 0.0]));
-    s.execute("layer.newText", json!({"text": "No explicit position"})).unwrap();
-    assert_eq!(s.active_comp().unwrap().layers.len(), 2);
-}
-
-/// The active comp and the open comp tabs are saved with the project and restored on open (#748).
-#[test]
-fn reopening_a_project_restores_its_active_comp() {
-    use effectcraft_project::ItemId;
-    let dir = std::env::temp_dir().join(format!("ec-test-748-{}", std::process::id()));
-    std::fs::create_dir_all(&dir).unwrap();
-    let path = dir.join("view.ecproj").to_string_lossy().to_string();
-    let mut s = Session::default();
-    let a = s.execute("comp.new", json!({"name": "CompA"})).unwrap()["comp"].as_u64().unwrap();
-    let b = s.execute("comp.new", json!({"name": "CompB"})).unwrap()["comp"].as_u64().unwrap();
-    let c = s.execute("comp.new", json!({"name": "CompC"})).unwrap()["comp"].as_u64().unwrap();
-    s.execute("comp.open", json!({"comp": "CompB"})).unwrap();
-    s.state.open_comps.retain(|id| id.0 != c);
-    s.execute("file.saveAs", json!({"path": path})).unwrap();
-    let mut s2 = Session::default();
-    s2.execute("file.open", json!({"path": path})).unwrap();
-    assert_eq!(s2.state.active_comp, Some(ItemId(b)));
-    assert_eq!(s2.state.open_comps, vec![ItemId(a), ItemId(b)]);
-    assert!(!s2.is_dirty());
-
-    // A file from before the view was saved opens on its first comp, as it always did.
-    let text = std::fs::read_to_string(&path).unwrap();
-    let mut old: serde_json::Value = serde_json::from_str(&text).unwrap();
-    let obj = old.as_object_mut().unwrap();
-    obj.remove("activeComp");
-    obj.remove("openComps");
-    std::fs::write(&path, serde_json::to_string_pretty(&old).unwrap()).unwrap();
-    let mut s3 = Session::default();
-    s3.execute("file.open", json!({"path": path})).unwrap();
-    assert_eq!((s3.state.active_comp, s3.state.open_comps.clone()), (Some(ItemId(a)), vec![ItemId(a)]));
-
-    // Ids that no longer name a comp (edited by hand, or written by another tool) fall back.
-    obj_set(&mut old, json!(999), json!([999, b, "x"]));
-    std::fs::write(&path, serde_json::to_string_pretty(&old).unwrap()).unwrap();
-    let mut s4 = Session::default();
-    s4.execute("file.open", json!({"path": path})).unwrap();
-    assert_eq!((s4.state.active_comp, s4.state.open_comps.clone()), (Some(ItemId(b)), vec![ItemId(b)]));
-    obj_set(&mut old, json!(999), json!([]));
-    std::fs::write(&path, serde_json::to_string_pretty(&old).unwrap()).unwrap();
-    let mut s5 = Session::default();
-    s5.execute("file.open", json!({"path": path})).unwrap();
-    assert_eq!((s5.state.active_comp, s5.state.open_comps.clone()), (Some(ItemId(a)), vec![ItemId(a)]));
-
-    // XML copies carry it too.
-    let xml = dir.join("view.ecprojx").to_string_lossy().to_string();
-    s.execute("file.saveAs", json!({"path": xml})).unwrap();
-    let mut s6 = Session::default();
-    s6.execute("file.open", json!({"path": xml})).unwrap();
-    assert_eq!(s6.state.active_comp, Some(ItemId(b)));
-    let _ = std::fs::remove_dir_all(dir);
-
-    fn obj_set(v: &mut serde_json::Value, active: serde_json::Value, open: serde_json::Value) {
-        let o = v.as_object_mut().unwrap();
-        o.insert("activeComp".into(), active);
-        o.insert("openComps".into(), open);
-    }
-}
-
-/// Layer times are saved as exact ticks and read back unchanged, and each comp reopens at the
-/// current time it was saved at, not at 0, where a layer starting later shows nothing (#1714).
-#[test]
-fn reopening_a_project_restores_layer_times_and_current_time() {
-    use effectcraft_project::ItemId;
-    use effectcraft_time::{FrameRate, Tick};
-    let dir = std::env::temp_dir().join(format!("ec-test-1714-{}", std::process::id()));
-    std::fs::create_dir_all(&dir).unwrap();
-    let path = dir.join("times.ecproj").to_string_lossy().to_string();
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"name": "C", "width": 108, "height": 192, "duration": 60})).unwrap();
-    s.execute("layer.newSolid", json!({"name": "crown"})).unwrap();
-    let cid = s.active_comp_id().unwrap();
-    let comp = std::sync::Arc::make_mut(&mut s.project).comp_mut(cid).unwrap();
-    comp.frame_rate = FrameRate::FPS_59_94;
-    // The layer from the issue: 34f, 315f and 3033f at 59.94 fps.
-    let l = comp.layers.first_mut().unwrap();
-    (l.start_time, l.in_point, l.out_point) = (Tick(144_086_342_400), Tick(1_334_917_584_000), Tick(12_853_349_308_800));
-    s.execute("time.set", json!({"time": 6.0})).unwrap();
-    let t = s.time();
-    // A second comp keeps its own time.
-    let b = ItemId(s.execute("comp.new", json!({"name": "B"})).unwrap()["comp"].as_u64().unwrap());
-    s.execute("time.set", json!({"time": 2.0})).unwrap();
-    let tb = s.time();
-    s.execute("comp.open", json!({"comp": "C"})).unwrap();
-    s.execute("file.saveAs", json!({"path": path})).unwrap();
-
-    let mut s2 = Session::default();
-    s2.execute("file.open", json!({"path": path})).unwrap();
-    let l = s2.project.comp(cid).unwrap().layers.first().unwrap();
-    assert_eq!((l.start_time, l.in_point, l.out_point), (Tick(144_086_342_400), Tick(1_334_917_584_000), Tick(12_853_349_308_800)));
-    assert_eq!((s2.time(), s2.state.times.get(&b).copied()), (t, Some(tb)));
-    assert!(l.in_point <= s2.time() && s2.time() < l.out_point, "the layer shows at the reopened time");
-    assert!(!s2.is_dirty());
-
-    // Hand-edited times past the end or before the start land on the last or first frame.
-    let mut file: serde_json::Value = serde_json::from_str(&std::fs::read_to_string(&path).unwrap()).unwrap();
-    file["compTimes"] = json!({cid.0.to_string(): i64::MAX, b.0.to_string(): -5});
-    std::fs::write(&path, file.to_string()).unwrap();
-    let mut s3 = Session::default();
-    s3.execute("file.open", json!({"path": path})).unwrap();
-    let c = s3.project.comp(cid).unwrap();
-    assert_eq!(s3.time(), c.frame_rate.snap_nearest(c.duration - c.frame_duration()));
-    assert_eq!(s3.time(), c.frame_rate.snap_nearest(c.duration - c.frame_duration()));
-    assert_eq!(s3.state.times.get(&b).copied(), Some(Tick::ZERO));
-}
+mod anim_presets;
+mod anim_tools;
+mod camera_track;
+mod codec_options;
+mod color_view;
+mod crypto_pick;
+mod delete_keys;
+mod disk_cache;
+mod effects;
+mod essential;
+mod essential_more;
+mod face;
+mod fidelity;
+mod frame_export;
+mod fuzz_open;
+mod history;
+mod import_project;
+mod key_metadata_order;
+mod key_time;
+mod keylight;
+mod limits;
+mod lottie;
+mod m137;
+mod m145;
+mod markers;
+mod mask_warp;
+mod menu_cmds;
+mod model3d;
+mod models;
+mod motion_blur_depth;
+mod paint;
+mod panels;
+mod project_items;
+mod proxy;
+mod quick_offset;
+mod replace_source;
+mod rig3d;
+pub(crate) mod roto;
+mod sequence;
+mod session;
+mod settings;
+mod shortcut_cmds;
+pub(crate) mod stubs;
+mod styles;
+mod tail;
+mod text;
+mod text_edit;
+mod three_d;
+mod timeline;
+mod timeline_interchange;
+pub(crate) mod track;
+mod vector_import;
+mod viewer;
diff --git a/crates/engine/src/tests_anim_presets.rs b/crates/engine/src/tests/anim_presets.rs
similarity index 100%
rename from crates/engine/src/tests_anim_presets.rs
rename to crates/engine/src/tests/anim_presets.rs
diff --git a/crates/engine/src/tests_anim_tools.rs b/crates/engine/src/tests/anim_tools.rs
similarity index 99%
rename from crates/engine/src/tests_anim_tools.rs
rename to crates/engine/src/tests/anim_tools.rs
index 69b6afa06..06d194001 100644
--- a/crates/engine/src/tests_anim_tools.rs
+++ b/crates/engine/src/tests/anim_tools.rs
@@ -3,7 +3,7 @@
 use effectcraft_keyframe::evaluate;
 use serde_json::json;
 
-use crate::tests_timeline::{animate, prop, setup};
+use crate::tests::timeline::{animate, prop, setup};
 
 fn select(s: &mut crate::Session, layer: u64, path: &str) {
     s.execute("prop.select", json!({"layer": layer, "path": path})).unwrap();
diff --git a/crates/engine/src/tests_camera_track.rs b/crates/engine/src/tests/camera_track.rs
similarity index 87%
rename from crates/engine/src/tests_camera_track.rs
rename to crates/engine/src/tests/camera_track.rs
index 5bd5539c1..3ca8578a9 100644
--- a/crates/engine/src/tests_camera_track.rs
+++ b/crates/engine/src/tests/camera_track.rs
@@ -3,7 +3,7 @@
 
 use effectcraft_effects::camera_tracker as ct;
 use effectcraft_geom::vec3;
-use effectcraft_project::LayerId;
+use effectcraft_project::{Comp, Layer, LayerId, PropGroup};
 use effectcraft_raster::Image;
 use effectcraft_render::EvalCtx;
 use effectcraft_render::three_d::camera::active_camera;
@@ -11,7 +11,8 @@ use effectcraft_track::camtrack::linalg::{self, M3, V3};
 use serde_json::{Value, json};
 
 use crate::Session;
-use crate::tests_track::{H, W, frame_time, setup, texture};
+use crate::camera_track::Placed;
+use crate::tests::track::{H, W, frame_time, setup, texture};
 
 const F: f64 = 260.0;
 
@@ -77,10 +78,9 @@ fn status(s: &mut Session) -> Value {
     s.execute("camera.solveStatus", json!({})).unwrap()
 }
 
-#[test]
-fn track_camera_solves_and_creates_layers_on_the_plane() {
-    let (mut s, clip) = tracked(json!({}));
-    let st = status(&mut s);
+/// Solved with a sane error and focal length; returns the Camera Tracker effect group.
+fn assert_solved(s: &mut Session, clip: LayerId) -> PropGroup {
+    let st = status(s);
     assert_eq!(st["solved"], true, "{st}");
     let err = st["averageError"].as_f64().unwrap();
     assert!(err < 0.5, "average error {err}");
@@ -90,9 +90,12 @@ fn track_camera_solves_and_creates_layers_on_the_plane() {
     // Method Used / Average Error are reported in the effect.
     let g = s.active_comp().unwrap().layer(clip).unwrap().effects().unwrap().groups().next().unwrap().clone();
     assert!(matches!(g.prop(ct::METHOD_USED).map(|p| &p.value), Some(effectcraft_keyframe::Value::Str(m)) if !m.is_empty()));
+    g
+}
 
-    // Pick floor points on frame 12 (their 3D positions lie on y = 1.5 in the true scene: the
-    // ones seen below the horizon at the bottom of the frame).
+/// Pick floor points on frame 12 (their 3D positions lie on y = 1.5 in the true scene: the
+/// ones seen below the horizon at the bottom of the frame).
+fn select_floor_points(s: &mut Session) -> Vec<u64> {
     s.execute("time.set", json!({"time": frame_time(12).seconds()})).unwrap();
     let pts = s.execute("camera.points", json!({})).unwrap();
     let list = pts["points"].as_array().unwrap();
@@ -101,32 +104,19 @@ fn track_camera_solves_and_creates_layers_on_the_plane() {
     assert!(floor.len() >= 3, "{floor:?}");
     s.execute("camera.selectPoints", json!({"points": floor})).unwrap();
     assert_eq!(s.state.camera_points.len(), floor.len());
+    floor
+}
 
-    // Create Solid and Camera: one undo step, camera + solid.
-    let r = s.execute_checked("camera.createFromSolve", json!({"kind": "solid"})).unwrap();
-    let cam = LayerId(r["camera"].as_u64().unwrap());
-    let solid = LayerId(r["layers"][0].as_u64().unwrap());
-    let comp = s.active_comp().unwrap().clone();
-    assert!(comp.layer(cam).unwrap().is_camera());
-    assert_eq!(comp.layer(cam).unwrap().name, "3D Tracker Camera");
-    assert_eq!(comp.layers[0].id, cam);
-    let sl = comp.layer(solid).unwrap();
-    assert!(sl.switches.three_d);
-    assert!(sl.name.starts_with("Track Solid"));
-    // The camera is keyed on every frame.
-    assert_eq!(comp.layer(cam).unwrap().props.prop("transform/position").unwrap().keys.len(), 25);
-
-    // Every solved point projects through the created camera exactly where the solve puts it,
-    // and onto its tracked position (the footage fills the comp, so layer pixels are comp
-    // pixels): within 1 px for 95 % of the observations (the rest are the solve's outliers:
-    // features on occlusion edges), 0.5 px on average.
+/// Every solved point projects through the created camera exactly where the solve puts it,
+/// and onto its tracked position (the footage fills the comp, so layer pixels are comp
+/// pixels): within 1 px for 95 % of the observations (the rest are the solve's outliers:
+/// features on occlusion edges), 0.5 px on average.
+fn assert_reprojection(s: &Session, comp: &Comp, pl: &Placed, g: &PropGroup) {
     let cid = s.active_comp_id().unwrap();
-    let uid = g.uid;
-    let pl = crate::camera_track::placed(&s.project, cid, clip, uid).unwrap();
-    let tracks = ct::tracks(&crate::camera_track::static_params(&g)).unwrap();
+    let tracks = ct::tracks(&crate::camera_track::static_params(g)).unwrap();
     let mut errs = vec![];
     for k in [0u32, 6, 12, 18, 24] {
-        let ctx = EvalCtx::new(&s.project, cid, &comp, frame_time(k));
+        let ctx = EvalCtx::new(&s.project, cid, comp, frame_time(k));
         let camst = active_camera(&ctx);
         for sp in pl.solve.visible(k as usize) {
             let Some(obs) = tracks.track(sp.id).and_then(|t| t.at(k)) else { continue };
@@ -142,34 +132,31 @@ fn track_camera_solves_and_creates_layers_on_the_plane() {
     let p95 = errs[errs.len() * 95 / 100];
     let mean = errs.iter().sum::<f64>() / errs.len() as f64;
     assert!(p95 < 1.0 && mean < 0.5, "p95 {p95} px, mean {mean} px");
+}
 
-    // The solid lies on the selected points' plane.
+/// The solid lies on the selected points' plane and faces the camera.
+fn assert_solid_on_plane(s: &Session, comp: &Comp, sl: &Layer, pl: &Placed, size: f64) {
+    let cid = s.active_comp_id().unwrap();
     let tr = sl.props.sub("transform").unwrap();
     let pos = tr.get("position").unwrap().value.as_vec3();
     let ori = tr.get("orientation").unwrap().value.as_vec3();
     let normal = linalg::mv(&linalg::from_euler_xyz(ori), [0.0, 0.0, -1.0]);
-    let size = r["target"]["size"].as_f64().unwrap();
     for id in &s.state.camera_points {
         let w = pl.to_world(pl.solve.point(*id).unwrap().pos);
         let d = linalg::dot(linalg::sub(w, pos), normal).abs();
         assert!(d < 0.05 * size.max(1.0) + 1.0, "point {id} is {d} px off the plane");
     }
-    // The solid faces the camera.
-    let ctx = EvalCtx::new(&s.project, cid, &comp, frame_time(12));
+    let ctx = EvalCtx::new(&s.project, cid, comp, frame_time(12));
     let eye = active_camera(&ctx).eye;
     assert!(linalg::dot(normal, linalg::sub([eye.x, eye.y, eye.z], pos)) > 0.0);
+}
 
-    // Undo removes both layers; redo brings them back.
-    let before = comp.layers.len();
-    assert!(s.undo());
-    assert_eq!(s.active_comp().unwrap().layers.len(), before - 2);
-    assert!(s.redo());
-    assert_eq!(s.active_comp().unwrap().layers.len(), before);
-
-    // A second create reuses the camera: Create Multiple Nulls and Camera.
+/// A second create reuses the camera (Create Multiple Nulls and Camera), then Text and
+/// Shadow Catcher (+ light).
+fn assert_create_kinds(s: &mut Session, cam: LayerId, n_floor: usize) {
     let r = s.execute_checked("camera.createFromSolve", json!({"kind": "null", "multiple": true})).unwrap();
     assert_eq!(r["camera"].as_u64().unwrap(), cam.0);
-    assert_eq!(r["layers"].as_array().unwrap().len(), floor.len());
+    assert_eq!(r["layers"].as_array().unwrap().len(), n_floor);
     // Text and Shadow Catcher (+ light).
     let r = s.execute_checked("camera.createFromSolve", json!({"kind": "text"})).unwrap();
     assert_eq!(r["layers"].as_array().unwrap().len(), 1);
@@ -180,11 +167,12 @@ fn track_camera_solves_and_creates_layers_on_the_plane() {
     assert_eq!(comp.layer(ids[0]).unwrap().props.prop("materialOptions/acceptsShadows").unwrap().value.as_enum(), 2);
     assert!(comp.layer(ids[1]).unwrap().is_light());
     assert!(s.execute_checked("camera.createFromSolve", json!({"kind": "teapot"})).is_err());
+}
 
-    // Set Ground Plane and Origin: the target becomes the origin; a null created there sits at
-    // (0, 0, 0) lying on the X-Z plane (its front facing up, −y).
+/// Set Ground Plane and Origin, then an explicit target.
+fn assert_ground_and_target(s: &mut Session) {
     s.execute_checked("camera.setGroundPlane", json!({})).unwrap();
-    assert_eq!(status(&mut s)["groundPlane"], true);
+    assert_eq!(status(s)["groundPlane"], true);
     let r = s.execute_checked("camera.createFromSolve", json!({"kind": "null"})).unwrap();
     let null = LayerId(r["layers"][0].as_u64().unwrap());
     let tr = s.active_comp().unwrap().layer(null).unwrap().props.sub("transform").unwrap().clone();
@@ -203,6 +191,44 @@ fn track_camera_solves_and_creates_layers_on_the_plane() {
     assert!(linalg::norm(linalg::sub(pos, [10.0, 0.0, 20.0])) < 1e-6, "{pos:?}");
     let front = linalg::mv(&linalg::from_euler_xyz(tr.get("orientation").unwrap().value.as_vec3()), [0.0, 0.0, -1.0]);
     assert!(linalg::norm(linalg::sub(front, [0.0, 0.0, -1.0])) < 1e-6, "{front:?}");
+}
+
+#[test]
+fn track_camera_solves_and_creates_layers_on_the_plane() {
+    let (mut s, clip) = tracked(json!({}));
+    let g = assert_solved(&mut s, clip);
+    let floor = select_floor_points(&mut s);
+
+    // Create Solid and Camera: one undo step, camera + solid.
+    let r = s.execute_checked("camera.createFromSolve", json!({"kind": "solid"})).unwrap();
+    let cam = LayerId(r["camera"].as_u64().unwrap());
+    let solid = LayerId(r["layers"][0].as_u64().unwrap());
+    let comp = s.active_comp().unwrap().clone();
+    assert!(comp.layer(cam).unwrap().is_camera());
+    assert_eq!(comp.layer(cam).unwrap().name, "3D Tracker Camera");
+    assert_eq!(comp.layers[0].id, cam);
+    let sl = comp.layer(solid).unwrap();
+    assert!(sl.switches.three_d);
+    assert!(sl.name.starts_with("Track Solid"));
+    // The camera is keyed on every frame.
+    assert_eq!(comp.layer(cam).unwrap().props.prop("transform/position").unwrap().keys.len(), 25);
+
+    let cid = s.active_comp_id().unwrap();
+    let uid = g.uid;
+    let pl = crate::camera_track::placed(&s.project, cid, clip, uid).unwrap();
+    assert_reprojection(&s, &comp, &pl, &g);
+    assert_solid_on_plane(&s, &comp, sl, &pl, r["target"]["size"].as_f64().unwrap());
+
+    // Undo removes both layers; redo brings them back.
+    let before = comp.layers.len();
+    assert!(s.undo());
+    assert_eq!(s.active_comp().unwrap().layers.len(), before - 2);
+    assert!(s.redo());
+    assert_eq!(s.active_comp().unwrap().layers.len(), before);
+
+    assert_create_kinds(&mut s, cam, floor.len());
+
+    assert_ground_and_target(&mut s);
 
     // Serde keeps the analysis.
     let back = effectcraft_project::Project::from_json(&s.project.to_json()).unwrap();
diff --git a/crates/engine/src/tests_codec_options.rs b/crates/engine/src/tests/codec_options.rs
similarity index 100%
rename from crates/engine/src/tests_codec_options.rs
rename to crates/engine/src/tests/codec_options.rs
diff --git a/crates/engine/src/tests_color_view.rs b/crates/engine/src/tests/color_view.rs
similarity index 100%
rename from crates/engine/src/tests_color_view.rs
rename to crates/engine/src/tests/color_view.rs
diff --git a/crates/engine/src/tests/crypto_pick.rs b/crates/engine/src/tests/crypto_pick.rs
new file mode 100644
index 000000000..eacae55af
--- /dev/null
+++ b/crates/engine/src/tests/crypto_pick.rs
@@ -0,0 +1,787 @@
+//! `effect.pickCryptomatte` / `effect.cryptomatteAt` (#473): the Cryptomatte eyedropper reads the
+//! aux channels the effect renders from (footage at its source time, a 3D precomp's generated
+//! pass) and edits the Selection text in one undo step.
+
+use std::sync::Arc;
+
+use effectcraft_project::{Footage, FootageKind, ItemId};
+use effectcraft_raster::channels3d::{crypto_float, crypto_hash};
+use effectcraft_raster::{AuxChannels, Image};
+use effectcraft_time::{FrameRate, Tick};
+use serde_json::{Value, json};
+
+use crate::Session;
+use crate::render::FootageSource;
+
+const COMMA: &str = "Green, \"Glossy\"";
+
+/// 8 × 4 footage with a 16 × 8 Cryptomatte (two aux pixels per layer pixel). Layer pixels in x:
+/// 0-1 `left` (0.6) over `right` (0.4); 2-3 `left` (0.3) under the comma name (0.7), ranks out of
+/// order; 4-5 `star*`; 6 an ID missing from the manifest; 7 a 0.5 / 0.5 tie of `left` and
+/// `right`. Rows 3+ are empty. From 1 s of source time `late` replaces columns 0-1.
+struct Crypto;
+
+fn aux_at(t: Tick) -> AuxChannels {
+    let (w, h) = (16usize, 8usize);
+    let mut planes = vec![vec![0.0f32; w * h]; 4];
+    for (i, x) in (0..w * h).map(|i| (i, i % w)).filter(|(i, _)| i / w < 6) {
+        let late = if t >= Tick::from_seconds_f64(1.0) { "late" } else { "left" };
+        let (a, ca, b, cb) = match x {
+            0..4 => (late, 0.6, "right", 0.4),
+            4..8 => ("left", 0.3, COMMA, 0.7),
+            8..12 => ("star*", 1.0, "", 0.0),
+            12..14 => ("ghost", 1.0, "", 0.0),
+            _ => ("left", 0.5, "right", 0.5),
+        };
+        for (k, v) in [crypto_float(crypto_hash(a)), ca, crypto_float(crypto_hash(b)), cb].into_iter().enumerate() {
+            planes[k][i] = v;
+        }
+    }
+    let mut aux = AuxChannels::new(w as u32, h as u32, 1.0);
+    for (k, c) in ["R", "G", "B", "A"].iter().enumerate() {
+        aux.channels.push((format!("CryptoObject00.{c}"), planes[k].clone()));
+    }
+    aux.manifests = vec![("CryptoObject".into(), ["left", "right", "late", COMMA, "star*"].iter().map(|n| (n.to_string(), crypto_hash(n))).collect())];
+    aux
+}
+
+impl FootageSource for Crypto {
+    fn frame(&self, _: ItemId, f: &Footage, _: Tick) -> Option<Arc<Image>> {
+        Some(Arc::new(Image::new(f.width, f.height)))
+    }
+    fn aux(&self, _: ItemId, _: &Footage, t: Tick) -> Option<Arc<AuxChannels>> {
+        Some(Arc::new(aux_at(t)))
+    }
+}
+
+struct Probe;
+impl crate::Importer for Probe {
+    fn probe(&self, path: &str) -> Result<Footage, String> {
+        let duration = Tick::from_seconds_f64(2.0);
+        // A half-size proxy of the EXR.
+        let (width, height) = if path.contains("proxy") { (4, 2) } else { (8, 4) };
+        Ok(Footage {
+            path: path.into(),
+            kind: FootageKind::Video,
+            width,
+            height,
+            has_video: true,
+            frame_rate: FrameRate::from_f64(24.0),
+            duration,
+            ..Default::default()
+        })
+    }
+}
+
+fn session() -> Session {
+    let mut s = Session { footage: Arc::new(Crypto), importer: Some(Arc::new(Probe)), ..Default::default() };
+    let item = s.execute("file.import", json!({"paths": ["/renders/crypto.exr"]})).unwrap()["items"][0].clone();
+    s.execute("comp.new", json!({"name": "C", "width": 8, "height": 4, "frameRate": 24, "duration": 2})).unwrap();
+    s.execute("layer.addItem", json!({"item": item})).unwrap();
+    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
+    s
+}
+
+fn pick(s: &mut Session, x: f64, mode: &str) -> Value {
+    s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": x, "y": 1.5, "mode": mode})).unwrap()
+}
+
+fn selection(s: &Session) -> String {
+    let l = &s.active_comp().unwrap().layers[0];
+    let g = l.effects().unwrap().groups().next().unwrap();
+    match &g.prop("selection").unwrap().value {
+        effectcraft_keyframe::Value::Str(t) => t.clone(),
+        v => panic!("{v:?}"),
+    }
+}
+
+#[test]
+fn picks_replace_add_and_remove_in_one_undo_step_each() {
+    let mut s = session();
+    let steps = s.history.undo.len();
+    let r = pick(&mut s, 0.5, "replace");
+    assert_eq!((r["name"].as_str(), r["selection"].as_str(), r["changed"].as_bool()), (Some("left"), Some("left"), Some(true)), "{r}");
+    assert_eq!(r["hash"], format!("{:08x}", crypto_hash("left")));
+    assert_eq!(s.history.undo.len(), steps + 1);
+    // The highest coverage wins even when it is not rank 0; the name is quoted.
+    assert_eq!(pick(&mut s, 2.5, "add")["selection"], r#"left, "Green, \"Glossy\"""#);
+    // Adding it again changes nothing and leaves no undo step.
+    let again = pick(&mut s, 3.5, "add");
+    assert_eq!((again["changed"].as_bool(), s.history.undo.len()), (Some(false), steps + 2));
+    // A `*` name and an unnamed ID go in as hashes; a tie goes to rank 0.
+    pick(&mut s, 4.5, "add");
+    assert_eq!(pick(&mut s, 6.5, "add")["selection"], format!(r#"left, "Green, \"Glossy\"", <{:08x}>, <{:08x}>"#, crypto_hash("star*"), crypto_hash("ghost")));
+    assert_eq!(s.execute("effect.cryptomatteAt", json!({"effect": 1, "x": 7.5, "y": 0.5})).unwrap()["name"], "left");
+    let r = pick(&mut s, 0.0, "remove");
+    assert_eq!(r["selection"], format!(r#""Green, \"Glossy\"", <{:08x}>, <{:08x}>"#, crypto_hash("star*"), crypto_hash("ghost")));
+    assert_eq!(r["selected"], false);
+    // The text parses back to exactly the picked IDs.
+    let manifest = aux_at(Tick::ZERO).manifests[0].1.clone();
+    let got = effectcraft_effects::selection_hashes(&selection(&s), Some(&manifest));
+    assert_eq!(got, [COMMA, "star*", "ghost"].map(crypto_hash));
+    assert_eq!(s.history.undo.len(), steps + 5);
+    s.execute("edit.undo", json!({})).unwrap();
+    assert!(selection(&s).starts_with("left, "), "{}", selection(&s));
+    pick(&mut s, 2.0, "replace");
+    assert_eq!(selection(&s), r#""Green, \"Glossy\"""#);
+    // The same selection with other spacing: no change, no undo step.
+    s.execute_checked("prop.set", json!({"path": "effects/#1/selection", "value": " \"Green, \\\"Glossy\\\"\" "})).unwrap();
+    let n = s.history.undo.len();
+    assert_eq!((pick(&mut s, 2.0, "replace")["changed"].as_bool(), s.history.undo.len()), (Some(false), n));
+}
+
+#[test]
+fn bad_points_layers_and_modes_are_errors_and_change_nothing() {
+    let mut s = session();
+    let at = |s: &mut Session, x: f64, y: f64| s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": x, "y": y}));
+    for (x, y) in [(-0.1, 1.0), (8.0, 1.0), (1.0, 4.0), (1.0, 3.5), (1e300, -1e300)] {
+        assert!(at(&mut s, x, y).is_err(), "{x},{y}");
+        assert_eq!(s.execute("effect.cryptomatteAt", json!({"effect": 1, "x": x, "y": y})).unwrap(), Value::Null);
+    }
+    assert!(s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 1, "y": 1, "mode": "toggle"})).is_err());
+    assert!(s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 1})).is_err());
+    for scale in [0.0, -1.0, 2.0] {
+        assert!(s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 1, "y": 1, "scale": scale})).is_err(), "{scale}");
+    }
+    s.execute_checked("effect.apply", json!({"effect": "Gaussian Blur"})).unwrap();
+    assert!(s.execute_checked("effect.pickCryptomatte", json!({"effect": 2, "x": 1, "y": 1})).is_err(), "not a Cryptomatte effect");
+    assert_eq!(selection(&s), "");
+    // A layer without aux channels.
+    s.execute("layer.newSolid", json!({"name": "S"})).unwrap();
+    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
+    let e = s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 1, "y": 1})).unwrap_err().to_string();
+    assert!(e.contains("no Cryptomatte channels"), "{e}");
+    // An expression-driven Selection would ignore the edit.
+    let mut s = session();
+    s.execute_checked("prop.setExpression", json!({"path": "effects/#1/selection", "expression": "\"right\""})).unwrap();
+    assert!(s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 1, "y": 1})).is_err());
+    assert_eq!(s.execute("effect.cryptomatteAt", json!({"effect": 1, "x": 1, "y": 1})).unwrap()["selected"], false);
+}
+
+/// The pick reads the frame the render shows: Time Remap's source time, not the layer time.
+#[test]
+fn time_remap_picks_the_shown_source_frame() {
+    let mut s = session();
+    assert_eq!(pick(&mut s, 0.5, "replace")["name"], "left");
+    s.execute_checked("layer.enableTimeRemap", json!({})).unwrap();
+    s.execute_checked("prop.set", json!({"path": "timeRemap", "value": 1.5})).unwrap();
+    assert_eq!(pick(&mut s, 0.5, "replace")["name"], "late");
+}
+
+/// A precomp of a 3D comp: the generated CryptoObject pass names its layers.
+#[test]
+fn picks_on_a_precomp_of_a_3d_comp() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "Outer", "width": 40, "height": 20, "frameRate": 24, "duration": 1})).unwrap();
+    let l = s.execute("layer.newSolid", json!({"name": "Red, Ball", "width": 40, "height": 20})).unwrap()["layer"].clone();
+    s.execute("layer.setSwitch", json!({"layers": [l], "switch": "threeD", "value": true})).unwrap();
+    s.execute("layer.precompose", json!({"layers": [l], "name": "Inner"})).unwrap();
+    s.execute("layer.select", json!({"layers": [s.active_comp().unwrap().layers[0].id.0]})).ok();
+    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
+    let r = s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 20, "y": 10})).unwrap();
+    assert_eq!((r["name"].as_str(), r["selection"].as_str()), (Some("Red, Ball"), Some("\"Red, Ball\"")), "{r}");
+}
+
+/// The matte the rendered Cryptomatte effect gives the picked ID at the buffer pixel under
+/// `{x, y}`: the pick has to name the ID the effect's own input buffer samples there.
+fn rendered_matte_of_pick(s: &mut Session, x: f64, y: f64, scale: f64) -> (String, f32) {
+    let r = s.execute_checked("effect.pickCryptomatte", json!({"effect": "Cryptomatte", "x": x, "y": y, "scale": scale, "mode": "replace"})).unwrap();
+    let fx = s.active_comp().unwrap().layers[0].effects().unwrap().groups().position(|g| g.match_id == "ec.3d.cryptomatte").unwrap() + 1;
+    s.execute_checked("prop.set", json!({"path": format!("effects/#{fx}/matteOnly"), "value": true})).unwrap();
+    let (cid, comp) = (s.active_comp_id().unwrap(), s.active_comp().unwrap());
+    let layer = &comp.layers[0];
+    let ctx = effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time: Tick::ZERO, expr: None, footage: None };
+    let buf = s.renderer(effectcraft_render::RenderOpts { scale, ..Default::default() }).content_buf(&ctx, layer).unwrap();
+    let (px, py) = buf.to_px([x, y]);
+    let m = buf.img.get(px.floor() as i64, py.floor() as i64)[0];
+    (r["name"].as_str().unwrap_or("?").to_string(), m)
+}
+
+/// Between 3/4 and full resolution footage keeps its native pixels: at 0.8 the effect samples
+/// layer pixel 2 (the comma name, 0.7) at x = 2.2, not the 0.8-grid pixel snapped back to 1.
+#[test]
+fn pick_at_scale_0_8_matches_the_native_buffer_the_effect_renders() {
+    let mut s = session();
+    let (name, m) = rendered_matte_of_pick(&mut s, 2.2, 1.5, 0.8);
+    assert!(m >= 0.5, "picked {name:?}, but the render gives it matte {m} there");
+    assert_eq!(name, COMMA);
+}
+
+/// A half-size proxy renders a buffer at 0.5 layer pixels per pixel even at full resolution:
+/// x = 6.5 lies in buffer pixel 3, which samples layer x = 7 (the `left` / `right` tie).
+#[test]
+fn pick_on_a_proxy_matches_the_proxy_sized_buffer() {
+    let mut s = session();
+    let item = *s.project.items.iter().find(|(_, i)| matches!(i.kind, effectcraft_project::ItemKind::Footage(_))).unwrap().0;
+    s.execute("file.setProxy", json!({"item": item.0, "path": "/renders/crypto_proxy.exr"})).unwrap();
+    let (name, m) = rendered_matte_of_pick(&mut s, 6.5, 1.5, 1.0);
+    assert!(m >= 0.5, "picked {name:?}, but the render gives it matte {m} there");
+    assert_eq!(name, "left");
+}
+
+/// 1920-px footage with `left` up to x = 120 and `right` after it, and a 104-px proxy.
+struct Edge;
+impl FootageSource for Edge {
+    fn frame(&self, _: ItemId, f: &Footage, _: Tick) -> Option<Arc<Image>> {
+        Some(Arc::new(Image::new(f.width, f.height)))
+    }
+    fn aux(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<AuxChannels>> {
+        let (w, h) = (1920usize, 40usize);
+        let mut aux = AuxChannels::new(w as u32, h as u32, 1.0);
+        let ids = (0..w * h).map(|i| crypto_float(crypto_hash(if i % w < 120 { "left" } else { "right" }))).collect();
+        aux.channels = vec![("CryptoObject00.R".into(), ids), ("CryptoObject00.G".into(), vec![1.0; w * h])];
+        aux.manifests = vec![("CryptoObject".into(), ["left", "right"].iter().map(|n| (n.to_string(), crypto_hash(n))).collect())];
+        Some(Arc::new(aux))
+    }
+}
+
+/// Proxy buffer pixel 6's centre maps to layer x = 6.5 / (104 / 1920): 120.0 by division, but
+/// 119.99999999999999 by the reciprocal the effect multiplies with. The pick must agree.
+#[test]
+fn pick_maps_pixel_centres_bit_exactly_as_the_effect() {
+    let mut s = Session { footage: Arc::new(Edge), ..Default::default() };
+    let at = |path: &str, width| Footage {
+        path: path.into(),
+        kind: FootageKind::Video,
+        width,
+        height: 40,
+        has_video: true,
+        frame_rate: FrameRate::from_f64(24.0),
+        duration: Tick::from_seconds_f64(2.0),
+        ..Default::default()
+    };
+    s.importer = Some(Arc::new(EdgeProbe(at("/renders/edge.exr", 1920), at("/renders/edge_proxy.exr", 104))));
+    let item = s.execute("file.import", json!({"paths": ["/renders/edge.exr"]})).unwrap()["items"][0].clone();
+    s.execute("comp.new", json!({"name": "C", "width": 1920, "height": 40, "frameRate": 24, "duration": 2})).unwrap();
+    s.execute("layer.addItem", json!({"item": item})).unwrap();
+    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
+    s.execute("file.setProxy", json!({"item": item, "path": "/renders/edge_proxy.exr"})).unwrap();
+    let (name, m) = rendered_matte_of_pick(&mut s, 118.0, 5.0, 1.0);
+    assert_eq!((name.as_str(), m), ("left", 1.0));
+}
+
+struct EdgeProbe(Footage, Footage);
+impl crate::Importer for EdgeProbe {
+    fn probe(&self, path: &str) -> Result<Footage, String> {
+        Ok(if path.contains("proxy") { self.1.clone() } else { self.0.clone() })
+    }
+}
+
+/// Footage whose decoded frames are `num / den` of the probed size (a file re-rendered at another
+/// resolution, a relinked file): the render stretches them over the layer.
+struct OffNominal(u32, u32);
+impl FootageSource for OffNominal {
+    fn frame(&self, _: ItemId, f: &Footage, _: Tick) -> Option<Arc<Image>> {
+        Some(Arc::new(Image::new(f.width * self.0 / self.1, f.height * self.0 / self.1)))
+    }
+    fn aux(&self, _: ItemId, _: &Footage, t: Tick) -> Option<Arc<AuxChannels>> {
+        Some(Arc::new(aux_at(t)))
+    }
+}
+
+/// Points along rows `ys` where the picked ID isn't lit in the rendered matte under the point.
+fn mismatches(s: &mut Session, scales: &[f64], xs: impl Iterator<Item = f64> + Clone, ys: &[f64]) -> Vec<String> {
+    let mut bad = vec![];
+    for &scale in scales {
+        for (x, &y) in ys.iter().flat_map(|y| xs.clone().map(move |x| (x, y))) {
+            if s.execute("effect.cryptomatteAt", json!({"effect": "Cryptomatte", "x": x, "y": y, "scale": scale})).unwrap().is_null() {
+                continue;
+            }
+            let (name, m) = rendered_matte_of_pick(s, x, y, scale);
+            if m < 0.5 {
+                bad.push(format!("scale {scale} ({x:.2}, {y}): picked {name:?}, matte {m}"));
+            }
+        }
+    }
+    bad
+}
+
+const PREVIEW_SCALES: [f64; 7] = [1.0, 0.8, 0.75, 0.74, 0.5, 0.33, 0.25];
+
+/// The pick follows the decoded frame's real size, not the footage's nominal one.
+#[test]
+fn pick_matches_the_render_when_frames_decode_off_nominal_size() {
+    for (num, den) in [(2, 1), (1, 2), (3, 4)] {
+        let mut s = Session { footage: Arc::new(OffNominal(num, den)), importer: Some(Arc::new(Probe)), ..Default::default() };
+        let item = s.execute("file.import", json!({"paths": ["/renders/crypto.exr"]})).unwrap()["items"][0].clone();
+        s.execute("comp.new", json!({"name": "C", "width": 8, "height": 4, "frameRate": 24, "duration": 2})).unwrap();
+        s.execute("layer.addItem", json!({"item": item})).unwrap();
+        s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
+        let bad = mismatches(&mut s, &PREVIEW_SCALES, (0..80).map(|i| i as f64 * 0.1 + 0.05), &[0.3, 1.7, 2.6]);
+        assert!(bad.is_empty(), "decode {num}/{den}: {} mismatches:\n{}", bad.len(), bad.join("\n"));
+    }
+}
+
+/// A precomp of a 3D comp, with and without Preserve Resolution (drawn at full size below full
+/// resolution), behind a disabled effect: the pick names the ID the rendered matte shows.
+#[test]
+fn pick_matches_the_render_on_precomps_with_and_without_preserve_resolution() {
+    for preserve in [false, true] {
+        let mut s = Session::default();
+        s.execute("comp.new", json!({"name": "Outer", "width": 40, "height": 20, "frameRate": 24, "duration": 2})).unwrap();
+        let a = s.execute("layer.newSolid", json!({"name": "A", "width": 40, "height": 20})).unwrap()["layer"].clone();
+        let b = s.execute("layer.newSolid", json!({"name": "B", "width": 7, "height": 20})).unwrap()["layer"].clone();
+        s.execute_checked("prop.set", json!({"layer": b, "path": "transform/position", "value": [3.5, 10, -10]})).unwrap();
+        s.execute("layer.setSwitch", json!({"layers": [a, b], "switch": "threeD", "value": true})).unwrap();
+        s.execute("layer.precompose", json!({"layers": [a, b], "name": "Inner"})).unwrap();
+        let inner = *s.project.items.iter().find(|(_, i)| i.name == "Inner").unwrap().0;
+        s.execute_checked("comp.settings", json!({"comp": inner.0, "preserveResolution": preserve})).unwrap();
+        s.execute("layer.select", json!({"layers": [s.active_comp().unwrap().layers[0].id.0]})).ok();
+        s.execute_checked("effect.apply", json!({"effect": "Gaussian Blur"})).unwrap();
+        s.execute_checked("effect.toggle", json!({"effect": 1, "value": false})).unwrap();
+        s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
+        let bad = mismatches(&mut s, &PREVIEW_SCALES, (0..93).map(|i| i as f64 * 0.15 + 0.05), &[10.0]);
+        assert!(bad.is_empty(), "preserve {preserve}: {} mismatches:\n{}", bad.len(), bad.join("\n"));
+    }
+}
+
+/// `w` × `h` footage whose Cryptomatte has an ID per 37 × 29 px cell (`c<col>_<row>`, all in the
+/// manifest), one aux pixel per layer pixel. Built once, as the media pool keeps decoded aux.
+struct Cells(u32, u32, std::sync::OnceLock<Arc<AuxChannels>>);
+impl Cells {
+    fn name(x: usize, y: usize) -> String {
+        format!("c{}_{}", x / 37, y / 29)
+    }
+}
+impl FootageSource for Cells {
+    fn frame(&self, _: ItemId, f: &Footage, _: Tick) -> Option<Arc<Image>> {
+        Some(Arc::new(Image::new(f.width, f.height)))
+    }
+    fn aux(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<AuxChannels>> {
+        Some(self.2.get_or_init(|| Arc::new(self.build())).clone())
+    }
+}
+impl Cells {
+    fn build(&self) -> AuxChannels {
+        let (w, h) = (self.0 as usize, self.1 as usize);
+        let ids = (0..w * h).map(|i| crypto_float(crypto_hash(&Cells::name(i % w, i / w)))).collect();
+        let mut aux = AuxChannels::new(w as u32, h as u32, 1.0);
+        aux.channels = vec![("CryptoObject00.R".into(), ids), ("CryptoObject00.G".into(), vec![1.0; w * h])];
+        let names = (0..w.div_ceil(37)).flat_map(|x| (0..h.div_ceil(29)).map(move |y| Cells::name(x * 37, y * 29)));
+        aux.manifests = vec![("CryptoObject".into(), names.map(|n| (n.clone(), crypto_hash(&n))).collect())];
+        aux
+    }
+}
+
+struct CellsProbe(u32, u32);
+impl crate::Importer for CellsProbe {
+    fn probe(&self, path: &str) -> Result<Footage, String> {
+        // `…_proxy` is a half-size proxy (rounded up); `…still…` a still image.
+        let (width, height) = if path.contains("proxy") { (self.0.div_ceil(2), self.1.div_ceil(2)) } else { (self.0, self.1) };
+        let (frame_rate, duration) = (FrameRate::from_f64(24.0), Tick::from_seconds_f64(2.0));
+        let kind = if path.contains("still") { FootageKind::Still } else { FootageKind::Video };
+        Ok(Footage { path: path.into(), kind, width, height, has_video: true, frame_rate, duration, ..Default::default() })
+    }
+}
+
+fn cells_session(w: u32, h: u32, blur: bool) -> Session {
+    cells_session_at(w, h, blur, "/renders/cells.exr")
+}
+
+fn cells_session_at(w: u32, h: u32, blur: bool, path: &str) -> Session {
+    let mut s = Session { footage: Arc::new(Cells(w, h, Default::default())), importer: Some(Arc::new(CellsProbe(w, h))), ..Default::default() };
+    let item = s.execute("file.import", json!({"paths": [path]})).unwrap()["items"][0].clone();
+    s.execute("comp.new", json!({"name": "C", "width": w, "height": h, "frameRate": 24, "duration": 2})).unwrap();
+    s.execute("layer.addItem", json!({"item": item})).unwrap();
+    if blur {
+        s.execute_checked("effect.apply", json!({"effect": "Gaussian Blur"})).unwrap();
+        s.execute_checked("prop.set", json!({"path": "effects/#1/blurriness", "value": 40.0})).unwrap();
+    }
+    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
+    s
+}
+
+/// Hover latency of `effect.cryptomatteAt` (dev profile): the first call after the viewer's frame
+/// and the next ones, on footage (1080p, 4K, 4K behind a blur) and a 1080p 3D precomp. Run with
+/// `--ignored --nocapture`; it measures, it doesn't assert.
+#[test]
+#[ignore]
+fn hover_latency() {
+    let mut cases: Vec<(&str, Session)> = vec![
+        ("footage 1920x1080", cells_session(1920, 1080, false)),
+        ("footage 3840x2160", cells_session(3840, 2160, false)),
+        ("footage 3840x2160 + blur 40", cells_session(3840, 2160, true)),
+    ];
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "Outer", "width": 1920, "height": 1080, "frameRate": 24, "duration": 2})).unwrap();
+    let a = s.execute("layer.newSolid", json!({"name": "A", "width": 1920, "height": 1080})).unwrap()["layer"].clone();
+    let b = s.execute("layer.newSolid", json!({"name": "B", "width": 400, "height": 1080})).unwrap()["layer"].clone();
+    s.execute("layer.setSwitch", json!({"layers": [a, b], "switch": "threeD", "value": true})).unwrap();
+    s.execute("layer.precompose", json!({"layers": [a, b], "name": "Inner"})).unwrap();
+    s.execute("layer.select", json!({"layers": [s.active_comp().unwrap().layers[0].id.0]})).ok();
+    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
+    cases.push(("3D precomp 1920x1080", s));
+    for (name, mut s) in cases {
+        let cid = s.active_comp_id().unwrap();
+        let _ = s.render(cid, Tick::ZERO, effectcraft_render::RenderOpts::default());
+        let ms: Vec<String> = (0..6)
+            .map(|i| {
+                let t0 = std::time::Instant::now();
+                let r = s.execute("effect.cryptomatteAt", json!({"effect": "Cryptomatte", "x": 100.0 + 40.0 * i as f64, "y": 500.0})).unwrap();
+                assert!(!r.is_null(), "{name}");
+                format!("{:.3}", t0.elapsed().as_secs_f64() * 1e3)
+            })
+            .collect();
+        eprintln!("HOVER {name}: first {} ms, then {} ms", ms[0], ms[1..].join(" / "));
+    }
+}
+
+/// The hover's probe: built off the thread that asks, kept while only the Selection changes,
+/// rebuilt when anything it reads changes, and a job finished for an older state is not used.
+#[test]
+fn hover_probe_is_built_by_a_job_kept_across_picks_and_dropped_on_other_edits() {
+    let mut s = session();
+    let q = json!({"effect": 1, "x": 0.5, "y": 1.5});
+    let job = s.crypto_probe_job(&q).unwrap().expect("nothing built yet");
+    std::thread::spawn(job).join().unwrap();
+    assert!(s.crypto_probe_job(&q).unwrap().is_none(), "built");
+    assert_eq!(s.execute("effect.cryptomatteAt", q.clone()).unwrap()["name"], "left");
+    // Another scale or time is another probe.
+    assert!(s.crypto_probe_job(&json!({"effect": 1, "x": 0.5, "y": 1.5, "scale": 0.5})).unwrap().is_some());
+    assert!(s.crypto_probe_job(&json!({"effect": 1, "x": 0.5, "y": 1.5, "time": 1.0})).unwrap().is_some());
+    // A pick edits only the Selection: the probe stays.
+    pick(&mut s, 0.5, "replace");
+    assert!(s.crypto_probe_job(&q).unwrap().is_none(), "kept across the pick");
+    assert_eq!(s.execute("effect.cryptomatteAt", q.clone()).unwrap()["selected"], true);
+    // Other edits rebuild it, and the answer follows them.
+    s.execute_checked("layer.enableTimeRemap", json!({})).unwrap();
+    s.execute_checked("prop.set", json!({"path": "timeRemap", "value": 1.5})).unwrap();
+    let stale = s.crypto_probe_job(&q).unwrap().expect("time remap changed it");
+    assert_eq!(s.execute("effect.cryptomatteAt", q.clone()).unwrap()["name"], "late");
+    // A job that finishes after the next edit doesn't answer for it.
+    s.execute_checked("prop.set", json!({"path": "timeRemap", "value": 0.5})).unwrap();
+    stale();
+    assert!(s.crypto_probe_job(&q).unwrap().is_some(), "stale job result is not used");
+    assert_eq!(s.execute("effect.cryptomatteAt", q.clone()).unwrap()["name"], "left");
+    // Errors are kept too, and still errors.
+    s.execute("layer.newSolid", json!({"name": "S"})).unwrap();
+    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
+    let solid = json!({"effect": 1, "x": 1, "y": 1});
+    s.crypto_probe_job(&solid).unwrap().expect("solid")();
+    assert!(s.crypto_probe_job(&solid).unwrap().is_none());
+    assert!(s.execute("effect.cryptomatteAt", solid).unwrap_err().to_string().contains("no Cryptomatte channels"));
+}
+
+/// Picks on 1080p, 4K and odd-sized footage, at the viewer's resolutions and on a half-size proxy,
+/// name the ID the rendered matte shows under the point (points next to cell edges).
+#[test]
+fn picks_match_the_render_at_1080p_4k_odd_sizes_and_on_proxies() {
+    for (w, h) in [(1920, 1080), (3840, 2160), (1919, 1079)] {
+        let mut s = cells_session(w, h, false);
+        let (wl, hl) = (f64::from(w), f64::from(h));
+        let xs = [36.6, 37.2, 0.4, wl / 2.0 + 0.3, wl - 0.6, wl - 37.4];
+        let ys = [28.7, 29.1, hl - 0.5, hl / 3.0];
+        let mut bad = mismatches(&mut s, &[1.0, 0.5, 0.33, 0.25], xs.iter().copied(), &ys);
+        let item = *s.project.items.iter().find(|(_, i)| matches!(i.kind, effectcraft_project::ItemKind::Footage(_))).unwrap().0;
+        s.execute("file.setProxy", json!({"item": item.0, "path": "/renders/cells_proxy.exr"})).unwrap();
+        bad.extend(mismatches(&mut s, &[1.0, 0.5, 0.33, 0.25], xs.iter().copied(), &ys).into_iter().map(|b| format!("proxy {b}")));
+        assert!(bad.is_empty(), "{w}x{h}: {} mismatches:\n{}", bad.len(), bad.join("\n"));
+    }
+}
+
+/// The kept probe, and the aux channels it holds, go when the eyedropper is disarmed, when its
+/// layer or effect is deleted, on Open / New, and when its footage changes.
+#[test]
+fn hover_probe_is_released_on_disarm_delete_open_and_footage_changes() {
+    let q = json!({"effect": "Cryptomatte", "x": 100.0, "y": 100.0});
+    let ends: [(&str, fn(&mut Session)); 5] = [
+        ("disarm", |s| s.drop_crypto_probe()),
+        ("layer delete", |s| {
+            let lid = s.active_comp().unwrap().layers[0].id.0;
+            s.execute_checked("edit.clear", json!({"layers": [lid]})).unwrap();
+        }),
+        ("effect delete", |s| {
+            s.execute_checked("effect.remove", json!({"effect": "Cryptomatte"})).unwrap();
+        }),
+        ("open / new", |s| s.replace_project(effectcraft_project::Project::default(), None)),
+        ("footage change", |s| {
+            let f = s.project.items.values().find_map(|i| match &i.kind {
+                effectcraft_project::ItemKind::Footage(f) => Some(f.clone()),
+                _ => None,
+            });
+            s.forget_decoded(&f.unwrap());
+        }),
+    ];
+    for (what, end) in ends {
+        let mut s = cells_session(640, 360, false);
+        let aux = s.footage.aux(ItemId(0), &Footage::default(), Tick::ZERO).unwrap();
+        let unpinned = Arc::strong_count(&aux);
+        assert!(!s.execute("effect.cryptomatteAt", q.clone()).unwrap().is_null());
+        assert!(s.crypto_probe_stats().0 && Arc::strong_count(&aux) > unpinned, "{what}: kept");
+        end(&mut s);
+        assert!(!s.crypto_probe_stats().0, "{what}: the probe is gone");
+        assert_eq!(Arc::strong_count(&aux), unpinned, "{what}: its aux channels are let go");
+    }
+}
+
+/// A probe is keyed by the frame it reads: on a still, or footage held by Time Remap, every comp
+/// time shares one; each footage frame has its own, and so does each comp time once something
+/// before the Cryptomatte effect is animated.
+#[test]
+fn hover_probe_is_keyed_by_the_source_frame() {
+    let builds = |s: &mut Session, times: &[f64]| -> Vec<u64> {
+        let b = s.crypto_probe_stats().1;
+        times
+            .iter()
+            .map(|t| {
+                let r = s.execute("effect.cryptomatteAt", json!({"effect": "Cryptomatte", "x": 40.0, "y": 30.0, "time": t})).unwrap();
+                assert_eq!(r["name"], "c1_1");
+                s.crypto_probe_stats().1 - b
+            })
+            .collect()
+    };
+    let f = 1.0 / 24.0;
+    let mut s = cells_session_at(320, 180, false, "/renders/still.exr");
+    assert_eq!(builds(&mut s, &[0.0, f, 0.5, 1.9]), [1, 1, 1, 1], "a still: one probe");
+    let mut s = cells_session(320, 180, false);
+    assert_eq!(builds(&mut s, &[0.0, f * 0.4, f, f * 1.5, 0.0]), [1, 1, 2, 2, 3], "footage: a probe per frame");
+    s.execute_checked("layer.enableTimeRemap", json!({})).unwrap();
+    s.execute_checked("prop.toggleAnimation", json!({"path": "timeRemap", "value": false})).unwrap();
+    s.execute_checked("prop.set", json!({"path": "timeRemap", "value": 0.5})).unwrap();
+    assert_eq!(builds(&mut s, &[0.0, f, 1.2]), [1, 1, 1], "held by Time Remap: one source frame");
+    let mut s = cells_session_at(320, 180, true, "/renders/still.exr");
+    assert_eq!(builds(&mut s, &[0.0, f]), [1, 1], "a still blur");
+    s.execute_checked("prop.addKey", json!({"path": "effects/#1/blurriness", "time": 0.0, "value": 2.0})).unwrap();
+    s.execute_checked("prop.addKey", json!({"path": "effects/#1/blurriness", "time": 1.0, "value": 6.0})).unwrap();
+    assert_eq!(builds(&mut s, &[0.0, f, f]), [1, 2, 2], "an animated blur before it: per comp time");
+}
+
+/// Probes of two Cryptomatte effects (on two footage layers) at the same revision and frame
+/// don't answer for each other.
+#[test]
+fn hover_probes_are_per_layer_and_effect() {
+    /// `…late…` files have the IDs [`Crypto`] has from 1 s.
+    struct ByFile;
+    impl FootageSource for ByFile {
+        fn frame(&self, _: ItemId, f: &Footage, _: Tick) -> Option<Arc<Image>> {
+            Some(Arc::new(Image::new(f.width, f.height)))
+        }
+        fn aux(&self, _: ItemId, f: &Footage, t: Tick) -> Option<Arc<AuxChannels>> {
+            Some(Arc::new(aux_at(if f.path.contains("late") { Tick::from_seconds_f64(1.0) } else { t })))
+        }
+    }
+    let mut s = Session { footage: Arc::new(ByFile), importer: Some(Arc::new(Probe)), ..Default::default() };
+    let items = s.execute("file.import", json!({"paths": ["/renders/crypto.exr", "/renders/late.exr"]})).unwrap()["items"].clone();
+    s.execute("comp.new", json!({"name": "C", "width": 8, "height": 4, "frameRate": 24, "duration": 2})).unwrap();
+    let layers: Vec<Value> = (0..2).map(|i| s.execute("layer.addItem", json!({"item": items[i]})).unwrap()["layer"].clone()).collect();
+    for l in &layers {
+        s.execute_checked("effect.apply", json!({"layers": [l], "effect": "Cryptomatte"})).unwrap();
+    }
+    let on = |l: &Value| json!({"layer": l, "effect": 1, "x": 0.5, "y": 1.5});
+    for (l, want) in [(&layers[0], "left"), (&layers[1], "late"), (&layers[0], "left")] {
+        assert_eq!(s.execute("effect.cryptomatteAt", on(l)).unwrap()["name"], want);
+    }
+}
+
+/// [`Crypto`]'s IDs, counting the reads, and holding them while `hold` is set (a build caught
+/// in the middle).
+#[derive(Default)]
+struct Gate {
+    reads: std::sync::atomic::AtomicUsize,
+    hold: std::sync::atomic::AtomicBool,
+    entered: std::sync::atomic::AtomicBool,
+    /// Picture frames read (the effect's input render).
+    frames: std::sync::atomic::AtomicUsize,
+}
+impl FootageSource for Gate {
+    fn frame(&self, _: ItemId, f: &Footage, _: Tick) -> Option<Arc<Image>> {
+        self.frames.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
+        Some(Arc::new(Image::new(f.width, f.height)))
+    }
+    fn aux(&self, _: ItemId, _: &Footage, t: Tick) -> Option<Arc<AuxChannels>> {
+        use std::sync::atomic::Ordering::SeqCst;
+        self.reads.fetch_add(1, SeqCst);
+        self.entered.store(true, SeqCst);
+        while self.hold.load(SeqCst) {
+            std::thread::sleep(std::time::Duration::from_millis(1));
+        }
+        Some(Arc::new(aux_at(t)))
+    }
+}
+
+/// Only the newest request's build is kept: a job that finishes late doesn't evict a newer probe,
+/// a job superseded before it runs doesn't build, one superseded (or outdated by an edit) while
+/// it builds stores nothing, and `probeOnly` never builds on the asking thread.
+#[test]
+fn hover_probe_builds_store_only_the_newest_and_never_build_for_probe_only() {
+    use std::sync::atomic::Ordering::SeqCst;
+    let gate = Arc::new(Gate::default());
+    let mut s = session();
+    s.footage = gate.clone();
+    let at = |t: f64| json!({"effect": 1, "x": 0.5, "y": 1.5, "time": t});
+    let reads = || gate.reads.load(SeqCst);
+    // A late job for another frame doesn't evict the probe built since.
+    let job0 = s.crypto_probe_job(&at(0.0)).unwrap().unwrap();
+    s.execute("effect.cryptomatteAt", at(1.0)).unwrap();
+    assert!(s.crypto_probe_job(&at(1.0)).unwrap().is_none());
+    job0();
+    assert!(s.crypto_probe_job(&at(1.0)).unwrap().is_none(), "the late job evicted the newer probe");
+    // A request for another probe cancels the earlier job: it doesn't even build.
+    let (old, new) = (s.crypto_probe_job(&at(0.5)).unwrap().unwrap(), s.crypto_probe_job(&at(0.25)).unwrap().unwrap());
+    let before = reads();
+    old();
+    assert_eq!(reads(), before, "a superseded job doesn't build");
+    new();
+    assert!(reads() > before);
+    assert!(s.crypto_probe_job(&at(0.25)).unwrap().is_none(), "the newest request's probe is kept");
+    // The same request again doesn't cancel the job in flight.
+    let (a, b) = (s.crypto_probe_job(&at(1.5)).unwrap().unwrap(), s.crypto_probe_job(&at(1.5)).unwrap().unwrap());
+    a();
+    drop(b);
+    assert!(s.crypto_probe_job(&at(1.5)).unwrap().is_none());
+    // Superseded, or outdated by an edit, while it builds: it stores nothing.
+    for edit in [false, true] {
+        let job = s.crypto_probe_job(&at(0.75)).unwrap().unwrap();
+        gate.hold.store(true, SeqCst);
+        gate.entered.store(false, SeqCst);
+        let run = std::thread::spawn(job);
+        while !gate.entered.load(SeqCst) {
+            std::thread::sleep(std::time::Duration::from_millis(1));
+        }
+        if edit {
+            s.execute_checked("prop.set", json!({"path": "effects/#1/matteOnly", "value": true})).unwrap();
+        } else {
+            drop(s.crypto_probe_job(&at(0.8)).unwrap());
+        }
+        gate.hold.store(false, SeqCst);
+        run.join().unwrap();
+        let stored = if edit { s.crypto_probe_stats().0 } else { s.crypto_probe_job(&at(0.75)).unwrap().is_none() };
+        assert!(!stored, "edit {edit}: the outdated build was stored");
+    }
+    // `probeOnly`: pending without a probe, and nothing built.
+    let before = reads();
+    let mut q = at(0.0);
+    q["probeOnly"] = json!(true);
+    assert_eq!(s.execute("effect.cryptomatteAt", q.clone()).unwrap(), json!({"pending": true}));
+    q["mode"] = json!("add");
+    assert_eq!(s.execute("effect.pickCryptomatte", q.clone()).unwrap()["pending"], true);
+    assert_eq!(reads(), before, "nothing built for probeOnly");
+    s.crypto_probe_job(&q).unwrap().unwrap()();
+    assert_eq!(s.execute("effect.pickCryptomatte", q.clone()).unwrap()["selection"], "left");
+}
+
+/// A build cancelled while it reads the IDs (a newer request, disarming, an edit, another
+/// project) stops before it renders the effect's input, so the next build isn't kept waiting.
+#[test]
+fn a_cancelled_build_stops_before_rendering_its_input() {
+    use std::sync::atomic::Ordering::SeqCst;
+    let cancels: [(&str, fn(&mut Session)); 4] = [
+        ("newer request", |s| drop(s.crypto_probe_job(&json!({"effect": 1, "x": 0.5, "y": 1.5, "time": 1.5})).unwrap())),
+        ("disarm", |s| s.drop_crypto_probe()),
+        ("edit", |s| drop(s.execute_checked("prop.set", json!({"path": "effects/#1/matteOnly", "value": true})).unwrap())),
+        ("project switch", |s| s.replace_project(effectcraft_project::Project::default(), None)),
+    ];
+    for (what, cancel) in [("not cancelled", None), ("newer request", Some(0)), ("disarm", Some(1)), ("edit", Some(2)), ("project switch", Some(3))] {
+        let gate = Arc::new(Gate::default());
+        let mut s = session();
+        s.footage = gate.clone();
+        let job = s.crypto_probe_job(&json!({"effect": 1, "x": 0.5, "y": 1.5, "time": 0.5})).unwrap().unwrap();
+        gate.hold.store(true, SeqCst);
+        let run = std::thread::spawn(job);
+        while !gate.entered.load(SeqCst) {
+            std::thread::sleep(std::time::Duration::from_millis(1));
+        }
+        if let Some(k) = cancel {
+            cancels[k].1(&mut s);
+        }
+        gate.hold.store(false, SeqCst);
+        run.join().unwrap();
+        let rendered = gate.frames.load(SeqCst) > 0;
+        assert_eq!(rendered, cancel.is_none(), "{what}: the input was rendered: {rendered}");
+    }
+}
+
+/// The probe doesn't read the Cryptomatte effect's own Selection: keyframed, a still keeps one
+/// probe for every comp time (an animated effect before it still makes one per time).
+#[test]
+fn an_animated_selection_keeps_one_probe_on_a_still() {
+    let mut s = cells_session_at(320, 180, false, "/renders/still.exr");
+    for (t, v) in [(0.0, "c1_1"), (1.0, "c2_2")] {
+        s.execute_checked("prop.addKey", json!({"path": "effects/#1/selection", "time": t, "value": v})).unwrap();
+    }
+    let b = s.crypto_probe_stats().1;
+    for t in [0.0, 1.0 / 24.0, 0.5, 1.5] {
+        assert_eq!(s.execute("effect.cryptomatteAt", json!({"effect": "Cryptomatte", "x": 40.0, "y": 30.0, "time": t})).unwrap()["name"], "c1_1");
+    }
+    assert_eq!(s.crypto_probe_stats().1 - b, 1, "one probe for the still");
+}
+
+/// A panic while a probe is built on another thread becomes the probe's error: the job returns,
+/// the hover reports it, and it isn't retried for that frame.
+#[test]
+fn a_panicking_probe_build_becomes_an_error() {
+    struct Broken;
+    impl FootageSource for Broken {
+        fn frame(&self, _: ItemId, f: &Footage, _: Tick) -> Option<Arc<Image>> {
+            Some(Arc::new(Image::new(f.width, f.height)))
+        }
+        fn aux(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<AuxChannels>> {
+            panic!("a broken EXR reader")
+        }
+    }
+    let mut s = Session { footage: Arc::new(Broken), importer: Some(Arc::new(Probe)), ..Default::default() };
+    let item = s.execute("file.import", json!({"paths": ["/renders/crypto.exr"]})).unwrap()["items"][0].clone();
+    s.execute("comp.new", json!({"name": "C", "width": 8, "height": 4, "frameRate": 24, "duration": 2})).unwrap();
+    s.execute("layer.addItem", json!({"item": item})).unwrap();
+    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
+    let q = json!({"effect": 1, "x": 0.5, "y": 1.5, "probeOnly": true});
+    let job = s.crypto_probe_job(&q).unwrap().unwrap();
+    assert!(std::thread::spawn(job).join().is_ok(), "the job caught the panic");
+    assert!(s.crypto_probe_job(&q).unwrap().is_none(), "the error is kept");
+    let e = s.execute("effect.cryptomatteAt", q).unwrap_err().to_string();
+    assert!(e.contains("Reading the Cryptomatte IDs failed") && e.contains("a broken EXR reader"), "{e}");
+}
+
+/// Asking whether the probe is built changes nothing: asked for other frames while a build runs
+/// (the eyedropper's hover while a click waits), it doesn't cancel that build.
+#[test]
+fn asking_whether_a_probe_is_ready_cancels_no_build() {
+    let s = session();
+    let at = |t: f64| json!({"effect": 1, "x": 0.5, "y": 1.5, "time": t, "probeOnly": true});
+    let job = s.crypto_probe_job(&at(0.0)).unwrap().unwrap();
+    for t in [1.0, 0.5, 1.0, 0.25] {
+        assert!(!s.crypto_probe_ready(&at(t)).unwrap());
+    }
+    job();
+    assert!(s.crypto_probe_ready(&at(0.0)).unwrap(), "the build was cancelled");
+    assert!(s.crypto_probe_job(&at(0.0)).unwrap().is_none());
+}
+
+/// The probe renders with the render prefs (nested switches, draft shadows): changing them asks
+/// for a new one.
+#[test]
+fn a_render_prefs_change_asks_for_a_new_probe() {
+    let mut s = session();
+    let q = json!({"effect": 1, "x": 0.5, "y": 1.5});
+    s.crypto_probe_job(&q).unwrap().unwrap()();
+    assert!(s.crypto_probe_ready(&q).unwrap());
+    s.prefs.three_d.realtime_shadows = !s.prefs.three_d.realtime_shadows;
+    assert!(!s.crypto_probe_ready(&q).unwrap(), "draft shadows changed");
+    s.crypto_probe_job(&q).unwrap().unwrap()();
+    s.prefs.general.switches_affect_nested_comps = !s.prefs.general.switches_affect_nested_comps;
+    assert!(!s.crypto_probe_ready(&q).unwrap(), "nested switches changed");
+}
+
+/// A pick is an undo step named for it, and undoing, redoing or jumping over picks keeps the
+/// probe (only the Selection changed); undoing any other edit doesn't.
+#[test]
+fn undoing_picks_keeps_the_probe_and_the_step_says_pick() {
+    let mut s = session();
+    let q = json!({"effect": 1, "x": 0.5, "y": 1.5, "probeOnly": true});
+    s.crypto_probe_job(&q).unwrap().unwrap()();
+    let before = crate::history::state_id(&s.project);
+    pick(&mut s, 0.5, "replace");
+    assert_eq!(s.history.undo.last().unwrap().0, "Pick Cryptomatte");
+    pick(&mut s, 4.5, "add");
+    for (what, cmd) in [("undo", "edit.undo"), ("undo", "edit.undo"), ("redo", "edit.redo")] {
+        s.execute_checked(cmd, json!({})).unwrap();
+        assert!(s.crypto_probe_ready(&q).unwrap(), "{what} {}: probe dropped", selection(&s));
+    }
+    assert_eq!(s.execute("effect.cryptomatteAt", q.clone()).unwrap()["selected"], true);
+    assert!(s.goto_history(&before) && selection(&s).is_empty());
+    assert!(s.crypto_probe_ready(&q).unwrap(), "history jump: probe dropped");
+    s.execute_checked("prop.set", json!({"path": "transform/opacity", "value": 50})).unwrap();
+    s.crypto_probe_job(&q).unwrap().unwrap()();
+    s.execute_checked("edit.undo", json!({})).unwrap();
+    assert!(!s.crypto_probe_ready(&q).unwrap(), "an undone opacity change needs a new probe");
+}
diff --git a/crates/engine/src/tests_delete_keys.rs b/crates/engine/src/tests/delete_keys.rs
similarity index 100%
rename from crates/engine/src/tests_delete_keys.rs
rename to crates/engine/src/tests/delete_keys.rs
diff --git a/crates/engine/src/tests_disk_cache.rs b/crates/engine/src/tests/disk_cache.rs
similarity index 98%
rename from crates/engine/src/tests_disk_cache.rs
rename to crates/engine/src/tests/disk_cache.rs
index 3091964ad..119699aa8 100644
--- a/crates/engine/src/tests_disk_cache.rs
+++ b/crates/engine/src/tests/disk_cache.rs
@@ -30,12 +30,12 @@ fn project(s: &mut Session) -> effectcraft_project::ItemId {
 
 #[test]
 fn disk_cache_settings_persistence_and_invalidation() {
-    crate::tests_roto::hold_roto_cache_test_lock();
+    crate::tests::roto::hold_roto_cache_test_lock();
     let dir = folder("persist");
     let mut s = session(&dir);
     let st = s.execute_checked("cache.diskStats", json!({})).unwrap();
     assert_eq!(st["enabled"], json!(true));
-    assert_eq!(st["maxBytes"], json!(100u64 << 30));
+    assert_eq!(st["maxBytes"], json!(20u64 << 30));
     let cid = project(&mut s);
     let t = s.time();
     let first = s.render(cid, t, RenderOpts::default());
diff --git a/crates/engine/src/tests_effects.rs b/crates/engine/src/tests/effects.rs
similarity index 100%
rename from crates/engine/src/tests_effects.rs
rename to crates/engine/src/tests/effects.rs
diff --git a/crates/engine/src/tests_essential.rs b/crates/engine/src/tests/essential.rs
similarity index 100%
rename from crates/engine/src/tests_essential.rs
rename to crates/engine/src/tests/essential.rs
diff --git a/crates/engine/src/tests_essential_more.rs b/crates/engine/src/tests/essential_more.rs
similarity index 100%
rename from crates/engine/src/tests_essential_more.rs
rename to crates/engine/src/tests/essential_more.rs
diff --git a/crates/engine/src/tests_face.rs b/crates/engine/src/tests/face.rs
similarity index 99%
rename from crates/engine/src/tests_face.rs
rename to crates/engine/src/tests/face.rs
index 9e713ff8b..2a45da98f 100644
--- a/crates/engine/src/tests_face.rs
+++ b/crates/engine/src/tests/face.rs
@@ -6,7 +6,7 @@ use effectcraft_track::face::{FaceParams, LANDMARKS, MEASUREMENTS, render_synthe
 use serde_json::json;
 
 use crate::mask_track::MaskMethod;
-use crate::tests_track::{H, W, frame_time, setup};
+use crate::tests::track::{H, W, frame_time, setup};
 
 fn face(f: u32) -> FaceParams {
     let t = f as f64;
diff --git a/crates/engine/src/tests_fidelity.rs b/crates/engine/src/tests/fidelity.rs
similarity index 100%
rename from crates/engine/src/tests_fidelity.rs
rename to crates/engine/src/tests/fidelity.rs
diff --git a/crates/engine/src/tests_frame_export.rs b/crates/engine/src/tests/frame_export.rs
similarity index 100%
rename from crates/engine/src/tests_frame_export.rs
rename to crates/engine/src/tests/frame_export.rs
diff --git a/crates/engine/src/tests_fuzz_open.rs b/crates/engine/src/tests/fuzz_open.rs
similarity index 100%
rename from crates/engine/src/tests_fuzz_open.rs
rename to crates/engine/src/tests/fuzz_open.rs
diff --git a/crates/engine/src/tests_history.rs b/crates/engine/src/tests/history.rs
similarity index 100%
rename from crates/engine/src/tests_history.rs
rename to crates/engine/src/tests/history.rs
diff --git a/crates/engine/src/tests_import_project.rs b/crates/engine/src/tests/import_project.rs
similarity index 100%
rename from crates/engine/src/tests_import_project.rs
rename to crates/engine/src/tests/import_project.rs
diff --git a/crates/engine/src/tests_key_metadata_order.rs b/crates/engine/src/tests/key_metadata_order.rs
similarity index 100%
rename from crates/engine/src/tests_key_metadata_order.rs
rename to crates/engine/src/tests/key_metadata_order.rs
diff --git a/crates/engine/src/tests_key_time.rs b/crates/engine/src/tests/key_time.rs
similarity index 99%
rename from crates/engine/src/tests_key_time.rs
rename to crates/engine/src/tests/key_time.rs
index d42d6d4a0..b5ec3a159 100644
--- a/crates/engine/src/tests_key_time.rs
+++ b/crates/engine/src/tests/key_time.rs
@@ -4,7 +4,7 @@ use effectcraft_project::LayerId;
 use effectcraft_time::Tick;
 use serde_json::{Value, json};
 
-use crate::{Session, tests_timeline::prop};
+use crate::{Session, tests::timeline::prop};
 
 fn offset_layer(start: f64, stretch: f64) -> (Session, u64) {
     let mut s = Session::default();
diff --git a/crates/engine/src/tests_keylight.rs b/crates/engine/src/tests/keylight.rs
similarity index 100%
rename from crates/engine/src/tests_keylight.rs
rename to crates/engine/src/tests/keylight.rs
diff --git a/crates/engine/src/tests_limits.rs b/crates/engine/src/tests/limits.rs
similarity index 100%
rename from crates/engine/src/tests_limits.rs
rename to crates/engine/src/tests/limits.rs
diff --git a/crates/engine/src/tests_lottie.rs b/crates/engine/src/tests/lottie.rs
similarity index 100%
rename from crates/engine/src/tests_lottie.rs
rename to crates/engine/src/tests/lottie.rs
diff --git a/crates/engine/src/tests_m137.rs b/crates/engine/src/tests/m137.rs
similarity index 100%
rename from crates/engine/src/tests_m137.rs
rename to crates/engine/src/tests/m137.rs
diff --git a/crates/engine/src/tests_m145.rs b/crates/engine/src/tests/m145.rs
similarity index 99%
rename from crates/engine/src/tests_m145.rs
rename to crates/engine/src/tests/m145.rs
index 68b897617..831a05ead 100644
--- a/crates/engine/src/tests_m145.rs
+++ b/crates/engine/src/tests/m145.rs
@@ -345,7 +345,7 @@ fn render_queue_uses_default_folder_bit_depth_names_and_segments() {
 fn every_wired_setting_is_live_and_display_only_ones_are_documented() {
     let todo = crate::prefs::todo_keys();
     assert_eq!(todo, ["general.useSystemColorPicker", "composition.hardwareAcceleratePanels", "scripting.enableJsDebugger"]);
-    let docs = include_str!("../../../docs/preferences.md");
+    let docs = include_str!("../../../../docs/preferences.md");
     assert!(docs.contains("### Display-only settings"));
     assert!(!docs.contains("Not wired yet"));
 }
@@ -708,6 +708,11 @@ fn dynamic_menus_and_window_viewer_labels() {
     s.prefs.push_recent("/p/One.ecproj");
     let (e, _) = crate::menus::dynamic(&s, "recentProjects", &Default::default());
     assert_eq!((e[0].label.as_str(), e[0].command.as_str()), ("One.ecproj", "file.openRecent"));
+    // Two projects with the same file name show their paths.
+    s.prefs.push_recent("/q/One.ecproj");
+    s.prefs.push_recent("/p/Two.ecproj");
+    let (e, _) = crate::menus::dynamic(&s, "recentProjects", &Default::default());
+    assert_eq!(e.iter().map(|e| e.label.as_str()).collect::<Vec<_>>(), ["Two.ecproj", "/q/One.ecproj", "/p/One.ecproj"]);
     assert_eq!(crate::menus::dynamic(&s, "history", &Default::default()).0.len(), s.history.undo.len());
     let a = solid(&mut s, "#ff0000");
     s.state.selected_layers = vec![LayerId(a)];
diff --git a/crates/engine/src/tests_markers.rs b/crates/engine/src/tests/markers.rs
similarity index 99%
rename from crates/engine/src/tests_markers.rs
rename to crates/engine/src/tests/markers.rs
index afe4b9890..66aac5694 100644
--- a/crates/engine/src/tests_markers.rs
+++ b/crates/engine/src/tests/markers.rs
@@ -3,7 +3,7 @@
 
 use serde_json::json;
 
-use crate::tests_timeline::setup;
+use crate::tests::timeline::setup;
 
 #[test]
 fn comp_marker_dialog_fields_and_undo() {
diff --git a/crates/engine/src/tests_mask_warp.rs b/crates/engine/src/tests/mask_warp.rs
similarity index 98%
rename from crates/engine/src/tests_mask_warp.rs
rename to crates/engine/src/tests/mask_warp.rs
index 137feb1cb..adcea44be 100644
--- a/crates/engine/src/tests_mask_warp.rs
+++ b/crates/engine/src/tests/mask_warp.rs
@@ -11,7 +11,7 @@ use effectcraft_track::Homography;
 use serde_json::json;
 
 use crate::Session;
-use crate::tests_track::{FPS, H, W, frame_time, patch_frames, rotating_pose, setup, texture};
+use crate::tests::track::{FPS, H, W, frame_time, patch_frames, rotating_pose, setup, texture};
 
 fn pose_h(f: u32) -> Homography {
     let (c, rot, sc) = rotating_pose(f);
@@ -239,6 +239,28 @@ fn set_param(s: &mut Session, layer: LayerId, path: &str, v: serde_json::Value)
     s.execute("prop.set", json!({"layer": layer.0, "path": format!("effects/#1/{path}"), "value": v})).unwrap();
 }
 
+/// Stabilize, Crop, Auto-scale (the default) hides the borders; Crop leaves an opaque centre.
+fn assert_crop_framing(s: &mut Session, clip: LayerId) {
+    set_param(s, clip, "borders/framing", json!(2));
+    let st = s.execute("warp.status", json!({})).unwrap();
+    assert!(st["autoScale"].as_f64().unwrap() > 100.5, "{st}");
+    for f in 0..25 {
+        assert_eq!(transparent(&render(s, f)), 0, "frame {f}");
+    }
+    set_param(s, clip, "borders/framing", json!(1));
+    let st = s.execute("warp.status", json!({})).unwrap();
+    let crop: [f64; 4] = serde_json::from_value(st["crop"].clone()).unwrap();
+    for f in [0, 9, 24] {
+        let img = render(s, f);
+        for y in (crop[1].ceil() as u32 + 1)..(crop[3].floor() as u32 - 1) {
+            for x in (crop[0].ceil() as u32 + 1)..(crop[2].floor() as u32 - 1) {
+                assert!(img.get(x as i64, y as i64)[3] > 0.99, "frame {f} ({x}, {y})");
+            }
+        }
+        assert!(img.get(0, 0)[3] < 0.01);
+    }
+}
+
 #[test]
 fn warp_stabilizer_analyzes_and_stabilizes() {
     let (mut s, clip, solid) = setup(shaky);
@@ -289,25 +311,7 @@ fn warp_stabilizer_analyzes_and_stabilizes() {
     }
     set_param(&mut s, clip, "stabilization/result", json!(0));
 
-    // Stabilize, Crop, Auto-scale (the default) hides the borders; Crop leaves an opaque centre.
-    set_param(&mut s, clip, "borders/framing", json!(2));
-    let st = s.execute("warp.status", json!({})).unwrap();
-    assert!(st["autoScale"].as_f64().unwrap() > 100.5, "{st}");
-    for f in 0..25 {
-        assert_eq!(transparent(&render(&s, f)), 0, "frame {f}");
-    }
-    set_param(&mut s, clip, "borders/framing", json!(1));
-    let st = s.execute("warp.status", json!({})).unwrap();
-    let crop: [f64; 4] = serde_json::from_value(st["crop"].clone()).unwrap();
-    for f in [0, 9, 24] {
-        let img = render(&s, f);
-        for y in (crop[1].ceil() as u32 + 1)..(crop[3].floor() as u32 - 1) {
-            for x in (crop[0].ceil() as u32 + 1)..(crop[2].floor() as u32 - 1) {
-                assert!(img.get(x as i64, y as i64)[3] > 0.99, "frame {f} ({x}, {y})");
-            }
-        }
-        assert!(img.get(0, 0)[3] < 0.01);
-    }
+    assert_crop_framing(&mut s, clip);
     // Synthesize Edges fills most of the borders from neighbouring frames.
     set_param(&mut s, clip, "borders/framing", json!(3));
     let synth: usize = (0..25).map(|f| transparent(&render(&s, f))).sum();
diff --git a/crates/engine/src/tests_menu_cmds.rs b/crates/engine/src/tests/menu_cmds.rs
similarity index 99%
rename from crates/engine/src/tests_menu_cmds.rs
rename to crates/engine/src/tests/menu_cmds.rs
index 5131bf3f4..eb99d809f 100644
--- a/crates/engine/src/tests_menu_cmds.rs
+++ b/crates/engine/src/tests/menu_cmds.rs
@@ -641,7 +641,7 @@ fn work_area_stays_ordered_when_the_start_passes_the_end() {
 
 #[test]
 fn label_group_purge_and_edit_original() {
-    crate::tests_roto::hold_roto_cache_test_lock();
+    crate::tests::roto::hold_roto_cache_test_lock();
     let mut s = comp();
     let a = solid(&mut s, "#ff0000");
     let b = solid(&mut s, "#00ff00");
diff --git a/crates/engine/src/tests_model3d.rs b/crates/engine/src/tests/model3d.rs
similarity index 100%
rename from crates/engine/src/tests_model3d.rs
rename to crates/engine/src/tests/model3d.rs
diff --git a/crates/engine/src/tests_models.rs b/crates/engine/src/tests/models.rs
similarity index 98%
rename from crates/engine/src/tests_models.rs
rename to crates/engine/src/tests/models.rs
index 66111eb34..21d316e75 100644
--- a/crates/engine/src/tests_models.rs
+++ b/crates/engine/src/tests/models.rs
@@ -28,7 +28,7 @@ fn wait_loaded(s: &mut Session, task: Task) {
 
 #[test]
 fn models_are_listed_chosen_and_verified() {
-    crate::tests_roto::hold_roto_cache_test_lock();
+    crate::tests::roto::hold_roto_cache_test_lock();
     let (mut s, d) = session("list");
     std::fs::create_dir_all(&d).unwrap();
     let bogus = d.join("bogus.bin");
diff --git a/crates/engine/src/tests_motion_blur_depth.rs b/crates/engine/src/tests/motion_blur_depth.rs
similarity index 100%
rename from crates/engine/src/tests_motion_blur_depth.rs
rename to crates/engine/src/tests/motion_blur_depth.rs
diff --git a/crates/engine/src/tests_paint.rs b/crates/engine/src/tests/paint.rs
similarity index 100%
rename from crates/engine/src/tests_paint.rs
rename to crates/engine/src/tests/paint.rs
diff --git a/crates/engine/src/tests_panels.rs b/crates/engine/src/tests/panels.rs
similarity index 100%
rename from crates/engine/src/tests_panels.rs
rename to crates/engine/src/tests/panels.rs
diff --git a/crates/engine/src/tests_project_items.rs b/crates/engine/src/tests/project_items.rs
similarity index 100%
rename from crates/engine/src/tests_project_items.rs
rename to crates/engine/src/tests/project_items.rs
diff --git a/crates/engine/src/tests_proxy.rs b/crates/engine/src/tests/proxy.rs
similarity index 100%
rename from crates/engine/src/tests_proxy.rs
rename to crates/engine/src/tests/proxy.rs
diff --git a/crates/engine/src/tests_quick_offset.rs b/crates/engine/src/tests/quick_offset.rs
similarity index 100%
rename from crates/engine/src/tests_quick_offset.rs
rename to crates/engine/src/tests/quick_offset.rs
diff --git a/crates/engine/src/tests_replace_source.rs b/crates/engine/src/tests/replace_source.rs
similarity index 100%
rename from crates/engine/src/tests_replace_source.rs
rename to crates/engine/src/tests/replace_source.rs
diff --git a/crates/engine/src/tests_rig3d.rs b/crates/engine/src/tests/rig3d.rs
similarity index 90%
rename from crates/engine/src/tests_rig3d.rs
rename to crates/engine/src/tests/rig3d.rs
index d3b965107..d801a743a 100644
--- a/crates/engine/src/tests_rig3d.rs
+++ b/crates/engine/src/tests/rig3d.rs
@@ -49,45 +49,38 @@ fn camera(s: &mut Session) -> u64 {
     s.execute("layer.newCamera", json!({"name": "Cam", "position": [320, 180, -800], "poi": [320, 180, 0], "zoom": 900})).unwrap()["layer"].as_u64().unwrap()
 }
 
-#[test]
-fn stereo_rig_builds_eye_comps_and_glasses() {
-    let mut s = session();
-    let src = cid(&s);
-    let cam = camera(&mut s);
-    let items_before = s.project.items.len();
-    let r = s.execute("camera.stereoRig", json!({"sceneDepth": 4})).unwrap();
-    assert_eq!(s.project.items.len(), items_before + 3, "left, right and stereo comps");
-    assert_eq!(r["master"].as_u64(), Some(cam));
-    // Controls on a hidden null in the source comp.
-    let ctl = layer_in(&s, src, r["controls"].as_u64().unwrap());
+/// Controls on a hidden null in the source comp.
+fn assert_stereo_controls(ctl: &Layer) {
     assert_eq!(ctl.name, "Stereo 3D Controls");
     assert!(!ctl.switches.video);
     let fx = ctl.effects().unwrap().groups().next().unwrap().clone();
     assert!(matches!(&fx.kind, GroupKind::Effect { effect } if effect == effectcraft_effects::controls::STEREO_CONTROLS));
     assert_eq!(fx.get("sceneDepth").unwrap().value, KV::Scalar(4.0));
-    // Eye comps: an eye camera (two-node, linked by expressions) and the collapsed source comp.
-    let d = 0.04 * 640.0;
-    for (key, name, x) in [("leftComp", "Scene Left Eye", 320.0 - d / 2.0), ("rightComp", "Scene Right Eye", 320.0 + d / 2.0)] {
-        let ec = ItemId(r[key].as_u64().unwrap());
-        assert_eq!(s.project.item(ec).unwrap().name, name);
-        let c = s.project.comp(ec).unwrap();
-        assert_eq!((c.width, c.height), (640, 360));
-        assert_eq!(c.layers.len(), 2);
-        let cam = &c.layers[0];
-        assert!(cam.is_camera() && effectcraft_render::three_d::camera::is_two_node(cam));
-        assert!(close3(v3(cam, "transform/position"), [x, 180.0, -800.0], 1e-6), "{:?}", v3(cam, "transform/position"));
-        // Parallel eyes (no convergence): each looks straight ahead.
-        assert!(close3(v3(cam, "transform/poi"), [x, 180.0, 0.0], 1e-6), "{:?}", v3(cam, "transform/poi"));
-        assert_eq!(cam.props.prop("cameraOptions/zoom").unwrap().value, KV::Scalar(900.0));
-        for p in ["transform/position", "transform/poi", "cameraOptions/zoom"] {
-            let e = cam.props.prop(p).unwrap().expr.clone().unwrap();
-            assert!(e.text.contains("comp(\"Scene\")") && e.text.contains("Cam"), "{p}: {}", e.text);
-        }
-        let nest = &c.layers[1];
-        assert_eq!(nest.source, LayerSource::Comp { item: src });
-        assert!(nest.switches.collapse && nest.switches.three_d);
+}
+
+/// An eye comp: an eye camera (two-node, linked by expressions) at `x` and the collapsed source comp.
+fn assert_eye_comp(s: &Session, src: ItemId, ec: ItemId, name: &str, x: f64) {
+    assert_eq!(s.project.item(ec).unwrap().name, name);
+    let c = s.project.comp(ec).unwrap();
+    assert_eq!((c.width, c.height), (640, 360));
+    assert_eq!(c.layers.len(), 2);
+    let cam = &c.layers[0];
+    assert!(cam.is_camera() && effectcraft_render::three_d::camera::is_two_node(cam));
+    assert!(close3(v3(cam, "transform/position"), [x, 180.0, -800.0], 1e-6), "{:?}", v3(cam, "transform/position"));
+    // Parallel eyes (no convergence): each looks straight ahead.
+    assert!(close3(v3(cam, "transform/poi"), [x, 180.0, 0.0], 1e-6), "{:?}", v3(cam, "transform/poi"));
+    assert_eq!(cam.props.prop("cameraOptions/zoom").unwrap().value, KV::Scalar(900.0));
+    for p in ["transform/position", "transform/poi", "cameraOptions/zoom"] {
+        let e = cam.props.prop(p).unwrap().expr.clone().unwrap();
+        assert!(e.text.contains("comp(\"Scene\")") && e.text.contains("Cam"), "{p}: {}", e.text);
     }
-    // The stereo comp: left eye on top with 3D Glasses fed by both eyes; right eye hidden.
+    let nest = &c.layers[1];
+    assert_eq!(nest.source, LayerSource::Comp { item: src });
+    assert!(nest.switches.collapse && nest.switches.three_d);
+}
+
+/// The stereo comp: left eye on top with 3D Glasses fed by both eyes; right eye hidden.
+fn assert_stereo_comp(s: &Session, r: &serde_json::Value) {
     let oc = ItemId(r["stereoComp"].as_u64().unwrap());
     let out = s.project.comp(oc).unwrap();
     assert_eq!(s.project.item(oc).unwrap().name, "Scene Stereo 3D");
@@ -98,6 +91,23 @@ fn stereo_rig_builds_eye_comps_and_glasses() {
     assert!(matches!(&g.kind, GroupKind::Effect { effect } if effect == "ec.perspective.3dglasses"));
     assert_eq!(g.get("leftView").unwrap().value, KV::Layer(Some(l)));
     assert_eq!(g.get("rightView").unwrap().value, KV::Layer(Some(rr)));
+}
+
+#[test]
+fn stereo_rig_builds_eye_comps_and_glasses() {
+    let mut s = session();
+    let src = cid(&s);
+    let cam = camera(&mut s);
+    let items_before = s.project.items.len();
+    let r = s.execute("camera.stereoRig", json!({"sceneDepth": 4})).unwrap();
+    assert_eq!(s.project.items.len(), items_before + 3, "left, right and stereo comps");
+    assert_eq!(r["master"].as_u64(), Some(cam));
+    assert_stereo_controls(&layer_in(&s, src, r["controls"].as_u64().unwrap()));
+    let d = 0.04 * 640.0;
+    for (key, name, x) in [("leftComp", "Scene Left Eye", 320.0 - d / 2.0), ("rightComp", "Scene Right Eye", 320.0 + d / 2.0)] {
+        assert_eye_comp(&s, src, ItemId(r[key].as_u64().unwrap()), name, x);
+    }
+    assert_stereo_comp(&s, &r);
     // One undo step; redo; serde.
     let json = serde_json::to_string(&*s.project).unwrap();
     let back: Project = serde_json::from_str(&json).unwrap();
diff --git a/crates/engine/src/tests_roto.rs b/crates/engine/src/tests/roto.rs
similarity index 99%
rename from crates/engine/src/tests_roto.rs
rename to crates/engine/src/tests/roto.rs
index 33500b4ec..423af1d2f 100644
--- a/crates/engine/src/tests_roto.rs
+++ b/crates/engine/src/tests/roto.rs
@@ -8,7 +8,7 @@ use effectcraft_track::roto::rle;
 use serde_json::{Value, json};
 
 use crate::Session;
-use crate::tests_track::{H, W, frame_time, setup};
+use crate::tests::track::{H, W, frame_time, setup};
 
 /// Keep cache/model mutation tests from clearing segmentations under another fixture.
 /// Libtest runs each test on its own thread; the guard lives until that thread exits.
diff --git a/crates/engine/src/tests_sequence.rs b/crates/engine/src/tests/sequence.rs
similarity index 100%
rename from crates/engine/src/tests_sequence.rs
rename to crates/engine/src/tests/sequence.rs
diff --git a/crates/engine/src/tests/session.rs b/crates/engine/src/tests/session.rs
new file mode 100644
index 000000000..b5d1cbb5f
--- /dev/null
+++ b/crates/engine/src/tests/session.rs
@@ -0,0 +1,760 @@
+use serde_json::json;
+
+use crate::Session;
+
+fn demo() -> Session {
+    let mut s = Session::default();
+    s.execute("file.openDemoProject", json!({})).unwrap();
+    s
+}
+
+#[test]
+fn demo_opens_and_renders() {
+    let s = demo();
+    let cid = s.active_comp_id().unwrap();
+    let img = s.render(cid, s.time(), effectcraft_render::RenderOpts { scale: 0.25, ..Default::default() });
+    assert_eq!((img.width, img.height), (480, 270));
+    let lit = img.data.iter().filter(|p| p[3] > 0.99).count();
+    assert!(lit > 100_000, "{lit}");
+}
+
+/// The session's layer cache never changes pixels: scrubbing the demo (including back and
+/// forth, and across an edit made through a command) matches cache-less renders exactly.
+#[test]
+fn demo_layer_cache_is_transparent() {
+    let mut s = demo();
+    let cid = s.active_comp_id().unwrap();
+    let opts = effectcraft_render::RenderOpts { scale: 0.25, ..Default::default() };
+    let uncached = |s: &Session, t: f64| {
+        let mut r = effectcraft_render::Renderer::new(&s.project, s.footage.as_ref(), opts);
+        r.expr = s.expr.as_deref();
+        r.comp_frame(cid, effectcraft_time::Tick::from_seconds_f64(t))
+    };
+    let check = |s: &Session, t: f64| {
+        let a = s.render(cid, effectcraft_time::Tick::from_seconds_f64(t), opts);
+        let b = uncached(s, t);
+        assert!(a.data.iter().zip(&b.data).all(|(p, q)| (0..4).all(|c| (p[c] - q[c]).abs() < 1e-6)), "t={t}");
+    };
+    for t in [0.5, 1.0, 3.0, 3.0334, 6.0, 3.0, 0.5] {
+        check(&s, t);
+    }
+    assert!(s.layer_cache.stats().hits > 0);
+    // Edit the title's glow through the command layer, then scrub again.
+    let title = s.project.comp(cid).unwrap().layers.iter().find(|l| l.name == "EFFECTCRAFT").map(|l| l.id.0).unwrap();
+    s.execute("prop.set", json!({"layer": title, "path": "effects/#1/radius", "value": 5.0})).unwrap();
+    for t in [3.0, 0.5] {
+        check(&s, t);
+    }
+}
+
+/// `layer.addItem` puts the layer at `index` (1-based) in the stack and starts it at `time`, as a
+/// drop in the Timeline does (#89).
+#[test]
+fn add_item_at_a_stack_index_and_time() {
+    let mut s = Session::default();
+    let clip = s.execute("comp.new", json!({"name": "Clip", "width": 16, "height": 16, "frameRate": 30, "duration": 1})).unwrap()["comp"].as_u64().unwrap();
+    s.execute("comp.new", json!({"name": "Main", "width": 32, "height": 32, "frameRate": 30, "duration": 4})).unwrap();
+    for name in ["C", "B", "A"] {
+        s.execute("layer.newSolid", json!({"name": name})).unwrap();
+    }
+    let names = |s: &Session| s.active_comp().unwrap().layers.iter().map(|l| l.name.clone()).collect::<Vec<_>>();
+    s.execute("layer.addItem", json!({"item": clip, "index": 2, "time": 1.01})).unwrap();
+    assert_eq!(names(&s), ["A", "Clip", "B", "C"]);
+    let l = &s.active_comp().unwrap().layers[1];
+    assert_eq!(l.in_point, effectcraft_time::Tick::from_seconds_f64(1.0), "on the nearest frame");
+    // Past the bottom: the bottom.
+    s.execute("layer.addItem", json!({"item": clip, "index": 99})).unwrap();
+    assert_eq!(names(&s).last().map(String::as_str), Some("Clip 2"));
+    assert!(s.execute("layer.addItem", json!({"item": clip, "index": 0})).is_err(), "1-based");
+}
+
+/// Files dropped on the Timeline or the Composition viewer (`file.import {addToComp}`) become
+/// layers of the comp that was active, one under the other, where they were dropped (#85, #89).
+#[test]
+fn imported_files_go_into_the_comp_where_they_were_dropped() {
+    use effectcraft_project::{Footage, FootageKind};
+    struct Probe;
+    impl crate::Importer for Probe {
+        fn probe(&self, path: &str) -> Result<Footage, String> {
+            Ok(Footage { path: path.into(), kind: FootageKind::Still, width: 64, height: 32, has_video: true, ..Default::default() })
+        }
+    }
+    let mut s = Session { importer: Some(std::sync::Arc::new(Probe)), ..Default::default() };
+    s.execute("comp.new", json!({"name": "Main", "width": 320, "height": 180, "frameRate": 30, "duration": 4})).unwrap();
+    s.execute("layer.newSolid", json!({"name": "Bg"})).unwrap();
+    let params = json!({"paths": ["/drop/a.png", "/drop/b.png"], "addToComp": true, "position": [40.0, 50.0], "index": 1, "time": 1.0});
+    s.execute("file.import", params).unwrap();
+    let comp = s.active_comp().unwrap();
+    assert_eq!(comp.layers.iter().map(|l| l.name.as_str()).collect::<Vec<_>>(), ["a.png", "b.png", "Bg"]);
+    for l in &comp.layers[..2] {
+        assert_eq!(l.props.prop("transform/position").map(|p| p.value.clone()), Some(effectcraft_keyframe::Value::Vec3([40.0, 50.0, 0.0])));
+        assert_eq!(l.in_point, effectcraft_time::Tick::from_seconds_f64(1.0));
+    }
+    // Without `addToComp` they only import.
+    s.execute("file.import", json!({"paths": ["/drop/c.png"]})).unwrap();
+    assert_eq!(s.active_comp().unwrap().layers.len(), 3);
+    assert!(s.execute("layer.addItem", json!({"item": "a.png", "position": [1.0]})).is_err(), "position needs x and y");
+}
+
+/// #270: files dropped or picked in the Import dialog (`file.import {background}`) are probed in
+/// a background job that says which file it is reading and how many are left; then they arrive
+/// in one undo step, all selected, with a count. The same file imported again arrives again.
+#[test]
+fn background_imports_report_progress_and_select_what_arrived() {
+    use effectcraft_project::{Footage, FootageKind, ItemId};
+    use std::sync::Arc;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+    /// Probes file k once `allow` > k (a slow video; 5 s at most, so an import that waits for it
+    /// fails the test instead of hanging it); `.xyz` files fail.
+    struct Gated {
+        started: AtomicUsize,
+        allow: Arc<AtomicUsize>,
+    }
+    impl crate::Importer for Gated {
+        fn probe(&self, path: &str) -> Result<Footage, String> {
+            let k = self.started.fetch_add(1, Ordering::SeqCst);
+            let until = std::time::Instant::now() + std::time::Duration::from_secs(5);
+            while self.allow.load(Ordering::SeqCst) <= k && std::time::Instant::now() < until {
+                std::thread::sleep(std::time::Duration::from_millis(1));
+            }
+            if path.ends_with(".xyz") {
+                return Err("unsupported file".into());
+            }
+            Ok(Footage { path: path.into(), kind: FootageKind::Still, width: 64, height: 32, has_video: true, ..Default::default() })
+        }
+    }
+    let allow = Arc::new(AtomicUsize::new(1));
+    let mut s = Session { importer: Some(Arc::new(Gated { started: AtomicUsize::new(0), allow: allow.clone() })), ..Default::default() };
+    s.execute("comp.new", json!({"name": "Main", "width": 320, "height": 180, "frameRate": 30, "duration": 4})).unwrap();
+    let undo = s.history.undo.len();
+    let r = s.execute("file.import", json!({"paths": ["/drop/a.png", "/drop/b.png", "/drop/a.png"], "background": true})).unwrap();
+    let job = r["job"].as_str().unwrap().to_string();
+    // The first file is through; the second is being read.
+    let running = |s: &mut Session| s.execute("jobs.list", json!({})).unwrap()["running"].as_array().unwrap().clone();
+    let deadline = std::time::Instant::now() + std::time::Duration::from_secs(10);
+    while running(&mut s)[0]["done"] != json!(1) && std::time::Instant::now() < deadline {
+        std::thread::sleep(std::time::Duration::from_millis(2));
+    }
+    let row = running(&mut s)[0].clone();
+    assert_eq!(row["id"], json!(job));
+    assert_eq!(row["label"], json!("Importing 3 files"));
+    assert_eq!(row["message"], json!("b.png (2 of 3)"));
+    assert_eq!((row["done"].as_u64(), row["total"].as_u64()), (Some(1), Some(3)));
+    assert!(s.project.items.values().all(|i| i.name != "a.png"), "nothing is added before the import finishes");
+    allow.store(usize::MAX, Ordering::SeqCst);
+    s.execute("jobs.wait", json!({})).unwrap();
+    let names = |s: &Session, ids: &[ItemId]| ids.iter().map(|i| s.project.item(*i).unwrap().name.clone()).collect::<Vec<_>>();
+    assert_eq!(names(&s, &s.state.project_selection), ["a.png", "b.png", "a.png"], "everything imported is selected, the same file twice too");
+    assert_eq!(s.history.undo.len(), undo + 1, "one undo step");
+    let rec = s.job_log.last().unwrap();
+    assert_eq!((rec.status.as_str(), rec.message.as_str()), ("done", "Imported 3 items"));
+    assert!(s.drain_events().iter().any(|e| matches!(e, crate::Event::Toast { message, .. } if message == "Imported 3 items")));
+    // Dropped on the viewer: they become layers too; a file that can't be read is reported.
+    s.execute("file.import", json!({"paths": ["/drop/c.png", "/drop/d.xyz"], "background": true, "addToComp": true, "position": [10.0, 20.0]})).unwrap();
+    s.execute("jobs.wait", json!({})).unwrap();
+    assert_eq!(s.active_comp().unwrap().layers.iter().map(|l| l.name.as_str()).collect::<Vec<_>>(), ["c.png"]);
+    assert_eq!(s.job_log.last().unwrap().message, "Imported 1 item. /drop/d.xyz: unsupported file");
+    // Agents and scripts import at once by default.
+    let r = s.execute("file.import", json!({"paths": ["/drop/e.png"]})).unwrap();
+    assert_eq!(r["items"].as_array().map(Vec::len), Some(1));
+}
+
+/// Audio, Lock and Shy don't change pixels: toggling them keeps the cached layers (#103).
+#[test]
+fn audio_lock_and_shy_keep_cached_layers() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "C", "width": 160, "height": 90, "frameRate": 30, "duration": 1})).unwrap();
+    s.execute("layer.newSolid", json!({"color": "#3080ff", "width": 80, "height": 40})).unwrap();
+    s.execute("effect.apply", json!({"layer": "#1", "effect": "Gaussian Blur"})).unwrap();
+    s.execute("prop.set", json!({"layer": "#1", "path": "effects/#1/blurriness", "value": 12})).unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let t = s.time();
+    s.render(cid, t, Default::default());
+    let before = s.layer_cache.stats();
+    for sw in ["audio", "lock", "shy"] {
+        s.execute("layer.setSwitch", json!({"layers": ["#1"], "switch": sw, "value": sw != "audio"})).unwrap();
+    }
+    s.render(cid, t, Default::default());
+    let after = s.layer_cache.stats();
+    assert_eq!(after.misses, before.misses, "no layer rendered again");
+    assert!(after.hits > before.hits);
+}
+
+#[test]
+fn every_command_has_unique_id_and_runs_or_reports() {
+    let mut ids = std::collections::HashSet::new();
+    for c in crate::command_specs() {
+        assert!(ids.insert(c.id), "duplicate {}", c.id);
+    }
+    assert!(ids.len() >= 90, "{}", ids.len());
+}
+
+#[test]
+fn layer_workflow_with_undo() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "Test", "width": 640, "height": 360, "frameRate": 30, "duration": 4})).unwrap();
+    let r = s.execute("layer.newSolid", json!({"color": "#336699"})).unwrap();
+    let lid = r["layer"].as_u64().unwrap();
+    s.execute("prop.set", json!({"layer": lid, "path": "transform/opacity", "value": 50})).unwrap();
+    let tree = s.execute("layer.tree", json!({"layer": lid})).unwrap();
+    assert!(tree.to_string().contains("\"value\":50.0"));
+    s.execute("prop.toggleAnimation", json!({"layer": lid, "path": "transform/position"})).unwrap();
+    s.execute("time.set", json!({"time": 2.0})).unwrap();
+    s.execute("prop.set", json!({"layer": lid, "path": "transform/position", "value": [100, 100]})).unwrap();
+    let comp = s.active_comp().unwrap();
+    let pos = comp.layers[0].props.prop("transform/position").unwrap();
+    assert_eq!(pos.keys.len(), 2);
+    s.execute("prop.select", json!({"layer": lid, "path": "transform/position"})).unwrap();
+    assert_eq!(s.state.selected_keys.len(), 2);
+    s.execute("keys.easyEase", json!({})).unwrap();
+    s.execute("keys.move", json!({"delta": 0.5})).unwrap();
+    let pos = s.active_comp().unwrap().layers[0].props.prop("transform/position").unwrap().clone();
+    assert!((pos.keys[0].time.seconds() - 0.5).abs() < 0.02);
+    assert_eq!(pos.keys[0].out_interp, effectcraft_keyframe::Interp::Bezier);
+    // undo back to before the move
+    s.execute("edit.undo", json!({})).unwrap();
+    let pos = s.active_comp().unwrap().layers[0].props.prop("transform/position").unwrap().clone();
+    assert!(pos.keys[0].time.seconds().abs() < 0.02);
+    s.execute("effect.apply", json!({"layer": lid, "effect": "Gaussian Blur"})).unwrap();
+    s.execute("prop.set", json!({"layer": lid, "path": "effects/#1/blurriness", "value": 12})).unwrap();
+    // Applying selects the new effect (Edit ▸ Duplicate would duplicate it); select the layer.
+    s.execute("layer.select", json!({"layers": [lid]})).unwrap();
+    s.execute("edit.duplicate", json!({})).unwrap();
+    assert_eq!(s.active_comp().unwrap().layers.len(), 2);
+    s.execute("layer.precompose", json!({"layers": [1, 2], "name": "Pre"})).unwrap();
+    assert_eq!(s.active_comp().unwrap().layers.len(), 1);
+}
+
+#[test]
+fn text_shape_mask_matte_parent() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"width": 800, "height": 450, "duration": 3})).unwrap();
+    let t = s.execute("layer.newText", json!({"text": "Hello", "size": 90})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("layer.addTextAnimator", json!({"layer": t, "properties": ["position", "opacity"]})).unwrap();
+    let sh = s.execute("layer.newShape", json!({"kind": "star", "fill": "#ffcc00"})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("layer.addShapeItem", json!({"layer": sh, "kind": "trim"})).unwrap();
+    s.execute("layer.addMask", json!({"layer": sh, "shape": "ellipse"})).unwrap();
+    s.execute("layer.setMask", json!({"layer": sh, "mask": 1, "mode": "Subtract", "inverted": true})).unwrap();
+    s.execute("layer.setTrackMatte", json!({"layer": sh, "matte": t, "kind": "luma"})).unwrap();
+    s.execute("layer.setParent", json!({"layers": [sh], "parent": t})).unwrap();
+    assert!(s.execute("layer.setParent", json!({"layers": [t], "parent": sh})).is_err());
+    s.execute("layer.setBlendMode", json!({"layers": [sh], "mode": "Screen"})).unwrap();
+    s.execute("layer.setSwitch", json!({"layers": [sh], "switch": "threeD"})).unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let _ = s.render(cid, s.time(), Default::default());
+    let info = s.execute("comp.info", json!({})).unwrap();
+    assert_eq!(info["layers"].as_array().unwrap().len(), 2);
+}
+
+/// The toolbar's Fill / Stroke change a selected shape layer's paint (#205): a shape drawn
+/// without a stroke gets one, later edits change it, and the Contents "Add:" items (#206) include
+/// an empty Path and a Gradient Stroke that render.
+#[test]
+fn toolbar_fill_and_stroke_paint_selected_shape_layers() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"width": 400, "height": 300, "duration": 2})).unwrap();
+    let sh = s.execute("layer.newShape", json!({"kind": "rect", "fill": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
+    let paint = |s: &mut Session| s.execute("shape.fillStroke", json!({})).unwrap();
+    assert_eq!(paint(&mut s)["stroke"], serde_json::Value::Null, "drawn without a stroke");
+    s.execute("shape.fillStroke", json!({"stroke": "#00ff00", "strokeWidth": 6})).unwrap();
+    let p = paint(&mut s);
+    assert_eq!((p["stroke"][1].as_f64(), p["strokeWidth"].as_f64()), (Some(1.0), Some(6.0)), "{p}");
+    s.execute("shape.fillStroke", json!({"fill": "#0000ff", "strokeWidth": 3})).unwrap();
+    let p = paint(&mut s);
+    assert_eq!((p["fill"][2].as_f64(), p["strokeWidth"].as_f64()), (Some(1.0), Some(3.0)), "{p}");
+    // One stroke, before the fill (paths, stroke, fill), and each change is one undo step.
+    let l = s.active_comp().unwrap().layer(effectcraft_project::LayerId(sh)).unwrap().clone();
+    let group = l.props.group("contents/group").unwrap();
+    let order: Vec<&str> = group.sub("contents").unwrap().groups().map(|g| g.match_id.as_str()).collect();
+    assert_eq!(order, ["rect", "stroke", "fill"]);
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(paint(&mut s)["strokeWidth"].as_f64(), Some(6.0));
+    // Only shape layers.
+    s.execute("layer.newSolid", json!({"color": "#808080"})).unwrap();
+    assert!(s.execute("shape.fillStroke", json!({"fill": "#ffffff"})).is_err());
+    for kind in ["path", "gstroke"] {
+        let r = s.execute("layer.addShapeItem", json!({"layer": sh, "kind": kind})).unwrap();
+        assert!(r["path"].as_str().is_some_and(|p| p.starts_with("contents/")), "{r}");
+    }
+    let cid = s.active_comp_id().unwrap();
+    let _ = s.render(cid, s.time(), Default::default());
+}
+
+/// A Wiggle Paths saved without Spatial Phase gets the property, at 0°, after Temporal Phase when
+/// the project opens.
+#[test]
+fn opening_a_wiggle_paths_without_spatial_phase_adds_it() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"width": 400, "height": 300, "duration": 2})).unwrap();
+    let sh = s.execute("layer.newShape", json!({"kind": "rect", "fill": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
+    let uid = s.execute("layer.addShapeItem", json!({"layer": sh, "kind": "wiggle"})).unwrap()["uid"].as_u64().unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let mut old = effectcraft_project::Project::from_json(&s.project.to_file_json().unwrap()).unwrap();
+    let l = old.comp_mut(cid).unwrap().layer_mut(effectcraft_project::LayerId(sh)).unwrap();
+    let g = l.props.find_group_mut(uid).unwrap();
+    g.children.retain(|c| c.match_id() != "spatialPhase");
+    assert_eq!(g.children.len(), 7);
+    let next = old.next_id;
+    s.replace_project(old, None);
+    let l = s.active_comp().unwrap().layer(effectcraft_project::LayerId(sh)).unwrap().clone();
+    let g = l.props.find_group(uid).unwrap();
+    let ids: Vec<&str> = g.children.iter().map(|c| c.match_id()).collect();
+    assert_eq!(ids, ["size", "detail", "points", "speed", "correlation", "phase", "spatialPhase", "seed"]);
+    let sp = g.get("spatialPhase").unwrap();
+    assert_eq!((sp.name.as_str(), &sp.value), ("Spatial Phase", &effectcraft_keyframe::Value::Scalar(0.0)));
+    assert!(sp.uid >= next && s.project.next_id > sp.uid, "a fresh uid: {} (next {next})", sp.uid);
+}
+
+/// The toolbar's Fill Options / Stroke Options change a selected shape layer's paint kind (#732):
+/// None switches the fill off, a gradient turns the Fill into a Gradient Fill that keeps its
+/// opacity, Solid Color turns it back, and a Stroke kind adds a stroke where there is none.
+#[test]
+fn toolbar_fill_and_stroke_kinds_change_selected_shape_layers() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"width": 400, "height": 300, "duration": 2})).unwrap();
+    let sh = s.execute("layer.newShape", json!({"kind": "rect", "fill": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
+    let items = |s: &Session| -> Vec<(String, bool)> {
+        let l = s.active_comp().unwrap().layer(effectcraft_project::LayerId(sh)).unwrap();
+        l.props.group("contents/group/contents").unwrap().groups().map(|g| (g.match_id.clone(), g.enabled)).collect()
+    };
+    let kinds = |s: &mut Session| {
+        let p = s.execute("shape.fillStroke", json!({})).unwrap();
+        (p["fillType"].as_str().unwrap().to_string(), p["strokeType"].as_str().unwrap().to_string())
+    };
+    assert_eq!(kinds(&mut s), ("solid".into(), "none".into()));
+    let cid = s.active_comp_id().unwrap();
+    let centre = |s: &Session| s.render(cid, s.time(), Default::default()).get(200, 150);
+    let red = centre(&s);
+    // None switches the fill off: nothing is drawn, and the item stays.
+    s.execute("shape.fillStroke", json!({"fillType": "none"})).unwrap();
+    assert_eq!(items(&s), [("rect".into(), true), ("fill".into(), false)]);
+    assert_eq!(kinds(&mut s).0, "none");
+    assert_ne!(centre(&s), red, "the fill is off");
+    // A radial gradient: the Fill becomes a Gradient Fill (switched on) that keeps its opacity.
+    s.execute("shape.fillStroke", json!({"fillType": "solid", "fill": "#ff0000"})).unwrap();
+    assert_eq!(centre(&s), red);
+    let opacity = |s: &Session, m: &str| {
+        let l = s.active_comp().unwrap().layer(effectcraft_project::LayerId(sh)).unwrap();
+        l.props.group(&format!("contents/group/contents/{m}")).unwrap().get("opacity").unwrap().value.as_f64()
+    };
+    s.execute("prop.set", json!({"layer": sh, "path": "contents/group/contents/fill/opacity", "value": 40})).unwrap();
+    s.execute("shape.fillStroke", json!({"fillType": "radial"})).unwrap();
+    assert_eq!(items(&s), [("rect".into(), true), ("gfill".into(), true)]);
+    assert_eq!((kinds(&mut s).0.as_str(), opacity(&s, "gfill")), ("radial", 40.0));
+    s.execute("shape.fillStroke", json!({"fillType": "linear"})).unwrap();
+    assert_eq!(kinds(&mut s).0, "linear");
+    s.execute("shape.fillStroke", json!({"fillType": "solid", "fill": "#00ff00"})).unwrap();
+    assert_eq!(items(&s), [("rect".into(), true), ("fill".into(), true)]);
+    assert_eq!(opacity(&s, "fill"), 40.0);
+    // A Stroke kind adds a stroke (before the fill); None switches it off again; undo is per step.
+    s.execute("shape.fillStroke", json!({"strokeType": "linear"})).unwrap();
+    assert_eq!(items(&s), [("rect".into(), true), ("gstroke".into(), true), ("fill".into(), true)]);
+    s.execute("shape.fillStroke", json!({"strokeType": "none"})).unwrap();
+    assert_eq!(kinds(&mut s), ("solid".into(), "none".into()));
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(kinds(&mut s), ("solid".into(), "linear".into()));
+    assert!(s.execute("shape.fillStroke", json!({"fillType": "plaid"})).is_err());
+}
+
+/// Selecting a mask in the Timeline (its row or its Mask Path) selects all of its points, so the
+/// viewer drags the whole mask (#203); a shape's Path item works the same way.
+#[test]
+fn selecting_a_mask_selects_its_points() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"width": 400, "height": 300, "duration": 2})).unwrap();
+    let l = s.execute("layer.newSolid", json!({"color": "#808080"})).unwrap()["layer"].as_u64().unwrap();
+    let m1 = s.execute("layer.addMask", json!({"layer": l, "shape": "rect"})).unwrap()["mask"].as_u64().unwrap();
+    let m2 = s.execute("layer.addMask", json!({"layer": l, "shape": "ellipse"})).unwrap()["mask"].as_u64().unwrap();
+    let points = |s: &Session, m: u64| s.state.selected_vertices.iter().filter(|v| v.mask == m).count();
+    s.execute("prop.select", json!({"layer": l, "prop": m1, "selectKeys": false})).unwrap();
+    assert_eq!((points(&s, m1), s.state.selected_vertices.len()), (4, 4));
+    // Mask Path selects them too; Shift-adding another mask keeps the first.
+    let path = s.active_comp().unwrap().layer(effectcraft_project::LayerId(l)).unwrap().props.find_group(m2).unwrap().get("path").unwrap().uid;
+    s.execute("prop.select", json!({"layer": l, "prop": path, "add": true})).unwrap();
+    assert_eq!((points(&s, m1), points(&s, m2)), (4, 4));
+    // Another mask replaces them; another property deselects them.
+    s.execute("prop.select", json!({"layer": l, "prop": m2})).unwrap();
+    assert_eq!((points(&s, m1), points(&s, m2)), (0, 4));
+    // Delete removes the selected mask (not only its points).
+    s.execute("edit.clear", json!({})).unwrap();
+    let masks = |s: &Session| s.active_comp().unwrap().layer(effectcraft_project::LayerId(l)).unwrap().masks().unwrap().children.len();
+    assert_eq!(masks(&s), 1);
+    s.execute("prop.select", json!({"layer": l, "path": "transform/opacity"})).unwrap();
+    assert!(s.state.selected_vertices.is_empty());
+    let sh = s.execute("layer.newShape", json!({"kind": "star"})).unwrap()["layer"].as_u64().unwrap();
+    let star = s.execute("layer.addShapeItem", json!({"layer": sh, "kind": "path"})).unwrap()["uid"].as_u64().unwrap();
+    s.execute("prop.select", json!({"layer": sh, "prop": star})).unwrap();
+    assert_eq!(s.state.selected_vertices.len(), 0, "an empty Path has no points");
+}
+
+#[test]
+fn save_and_open_roundtrip() {
+    let mut s = demo();
+    let dir = std::env::temp_dir().join(format!("ec-test-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("demo.ecproj").to_string_lossy().to_string();
+    s.execute("file.saveAs", json!({"path": path})).unwrap();
+    let before = s.project.clone();
+    let mut s2 = Session::default();
+    s2.execute("file.open", json!({"path": path})).unwrap();
+    assert_eq!(*before, *s2.project);
+    let _ = std::fs::remove_dir_all(dir);
+}
+
+#[test]
+fn help_links_emit_urls() {
+    let mut s = Session::default();
+    let r = s.execute("help.discord", json!({})).unwrap();
+    assert_eq!(r["url"], "https://discord.gg/artcraft");
+    assert!(s.drain_events().iter().any(|e| matches!(e, crate::Event::OpenUrl(u) if u.contains("discord"))));
+    assert_eq!(s.execute("help.github", json!({})).unwrap()["url"], "https://github.com/storytold/effectcraft");
+}
+
+#[test]
+fn time_navigation() {
+    let mut s = demo();
+    s.execute("time.start", json!({})).unwrap();
+    let r = s.execute("time.nextKey", json!({})).unwrap();
+    assert!(r["time"].as_f64().unwrap() > 0.0);
+    s.execute("time.set", json!({"frame": 45})).unwrap();
+    assert_eq!(s.execute("time.step", json!({"frames": 5})).unwrap()["frame"], 50);
+}
+
+#[test]
+fn time_navigation_per_property() {
+    let mut s = demo();
+    // An animated property and the comp times of its keys.
+    let comp = s.active_comp().unwrap().clone();
+    let mut found = None;
+    for l in &comp.layers {
+        l.props.walk("", &mut |_, pr| {
+            if found.is_none() && pr.keys.len() >= 2 {
+                found = Some((pr.uid, pr.keys.iter().map(|k| l.comp_time(k.time)).collect::<Vec<_>>()));
+            }
+        });
+    }
+    let (uid, times) = found.expect("demo has an animated property");
+    s.set_time(effectcraft_time::Tick::ZERO);
+    let half = comp.frame_duration().0 / 2;
+    let expect = times.iter().copied().filter(|t| t.0 > half).min().unwrap();
+    s.execute("time.go", json!({"to": "nextKey", "prop": uid})).unwrap();
+    let snap = |t| comp.frame_rate.snap(t);
+    assert_eq!(s.time(), snap(expect));
+    // Going back from past the last key lands on the last key.
+    s.set_time(comp.duration);
+    s.execute("time.go", json!({"to": "prevKey", "prop": uid})).unwrap();
+    assert_eq!(s.time(), snap(*times.iter().max().unwrap()));
+}
+
+#[test]
+fn set_text_paragraph_fill_and_leading() {
+    use effectcraft_keyframe::{Justify, Value as KValue};
+    let mut s = demo();
+    let t = s.execute("layer.newText", json!({"text": "Hi"})).unwrap()["layer"].as_u64().unwrap();
+    let doc = |s: &Session| {
+        let l = s.active_comp().unwrap().layer(crate::project::LayerId(t)).unwrap().clone();
+        match &l.props.prop("text/sourceText").unwrap().value {
+            KValue::Text(d) => (**d).clone(),
+            v => panic!("{v:?}"),
+        }
+    };
+    for (key, j) in [
+        ("justifyLeft", Justify::JustifyLastLeft),
+        ("justifyCenter", Justify::JustifyLastCenter),
+        ("justifyRight", Justify::JustifyLastRight),
+        ("justifyAll", Justify::JustifyAll),
+        ("center", Justify::Center),
+    ] {
+        s.execute("layer.setText", json!({"layer": t, "justify": key})).unwrap();
+        assert_eq!(doc(&s).justify, j, "{key}");
+    }
+    s.execute("layer.setText", json!({"layer": t, "leading": 50, "applyFill": false, "applyStroke": true})).unwrap();
+    let d = doc(&s);
+    assert_eq!((d.leading, d.apply_fill, d.apply_stroke), (Some(50.0), false, true));
+    s.execute("layer.setText", json!({"layer": t, "leading": "auto"})).unwrap();
+    assert_eq!(doc(&s).leading, None);
+    s.execute("layer.setText", json!({"layer": t, "hScale": 120, "vScale": 80, "baselineShift": 4, "smallCaps": true, "strokeOverFill": true})).unwrap();
+    let d = doc(&s);
+    assert_eq!((d.h_scale, d.v_scale, d.baseline_shift, d.small_caps, d.stroke_over_fill), (120.0, 80.0, 4.0, true, true));
+}
+
+#[test]
+fn property_groups_report_actionable_errors() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "T"})).unwrap();
+    let l = s.execute("layer.newText", json!({"text": "Hi"})).unwrap()["layer"].as_u64().unwrap();
+    let uid = s.active_comp().unwrap().layer(crate::project::LayerId(l)).unwrap().props.group("text/pathOptions").unwrap().uid;
+    for selector in [json!({"path": "text"}), json!({"path": "text/pathOptions"}), json!({"path": format!("@{uid}")}), json!({"prop": uid})] {
+        let mut params = selector;
+        params["layer"] = json!(l);
+        for cmd in ["prop.get", "prop.set"] {
+            let err = s.execute(cmd, params.clone()).unwrap_err().to_string();
+            assert!(err.contains("is a property group"), "{cmd}: {err}");
+            assert!(err.contains("get_layer"), "{cmd}: {err}");
+        }
+    }
+    assert!(s.execute("prop.get", json!({"layer": l, "path": "text/sourceText"})).is_ok());
+    let err = s.execute("prop.get", json!({"layer": l, "path": "missing"})).unwrap_err().to_string();
+    assert!(err.contains("no property `missing`"), "{err}");
+}
+
+#[test]
+fn prop_get_and_render_rgba8() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "T", "width": 320, "height": 180, "duration": 2.0, "frameRate": 30})).unwrap();
+    let l = s.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("prop.addKey", json!({"layer": l, "path": "transform/position", "time": 0.0, "value": [0, 0]})).unwrap();
+    s.execute("prop.addKey", json!({"layer": l, "path": "transform/position", "time": 1.0, "value": [100, 50]})).unwrap();
+    let v = s.execute("prop.get", json!({"layer": l, "path": "transform/position", "time": 1.0})).unwrap();
+    assert_eq!(v["animated"], true);
+    assert_eq!(v["keys"].as_array().unwrap().len(), 2);
+    assert_eq!(v["value"][0].as_f64().unwrap(), 100.0);
+    let cid = s.resolve_comp(Some(&json!("T"))).unwrap();
+    let (w, h, rgba) = s.render_rgba8(cid, effectcraft_time::Tick::ZERO, 160).unwrap();
+    assert_eq!((w, h), (160, 90));
+    assert_eq!(rgba.len(), (w * h * 4) as usize);
+}
+
+#[test]
+fn params_docs_parse() {
+    use crate::commands::accepted_params;
+    let k = |d: &str| accepted_params(d).unwrap();
+    assert_eq!(k("{layers: [id|name|#n], add?, toggle?}"), ["layers", "add", "toggle"]);
+    assert_eq!(k("{time? (s) | frame? | timecode?}"), ["time", "frame", "timecode"]);
+    assert_eq!(k("{interpolation?|in?|out?: linear|bezier|hold, autoBezier?}"), ["interpolation", "in", "out", "autoBezier"]);
+    assert_eq!(k("{keys: [{layer, prop, time}], add?}"), ["keys", "add"]);
+    assert_eq!(k("{label: Red|Yellow|Aqua|…, layers?}"), ["label", "layers"]);
+    assert_eq!(k("{name?, background? [r,g,b]|#hex, open?}"), ["name", "background", "open"]);
+    assert!(k("{}").is_empty());
+    assert!(accepted_params("free text").is_none());
+    // Every registered command documents its params as a parseable key list.
+    for c in crate::command_specs() {
+        assert!(accepted_params(c.params).is_some(), "{}: {}", c.id, c.params);
+    }
+}
+
+#[test]
+fn execute_checked_rejects_unknown_params() {
+    let mut s = demo();
+    let e = s.execute_checked("layer.select", json!({"index": 2})).unwrap_err().to_string();
+    assert!(e.contains("`index`") && e.contains("layers, add, toggle"), "{e}");
+    s.execute_checked("layer.select", json!({"layers": ["#2"]})).unwrap();
+    assert_eq!(s.state.selected_layers.len(), 1);
+    // Aliases and always-accepted keys.
+    s.execute_checked("layer.select", json!({"layer": "#1", "comp": s.active_comp_id().unwrap().0})).unwrap();
+    s.execute_checked("time.set", json!({"frame": 3})).unwrap();
+    assert!(s.execute_checked("edit.undo", json!({"steps": 2})).is_err());
+    // Non-object params are not validated; the unchecked path stays lenient.
+    s.execute("layer.select", json!({"layers": ["#1"], "index": 2})).unwrap();
+}
+
+#[test]
+fn layer_tree_paths_resolve() {
+    let mut s = demo();
+    s.execute("effect.apply", json!({"layer": 1, "effect": "Gaussian Blur"})).unwrap();
+    let comp = s.execute("comp.info", json!({})).unwrap();
+    let mut checked = 0;
+    for l in comp["layers"].as_array().unwrap() {
+        let tree = s.execute("layer.tree", json!({"layer": l["id"]})).unwrap();
+        let mut stack = vec![tree["properties"].clone()];
+        while let Some(n) = stack.pop() {
+            if let Some(ch) = n["children"].as_array() {
+                stack.extend(ch.iter().cloned());
+                continue;
+            }
+            let path = n["path"].as_str().unwrap();
+            let got = s.execute("prop.get", json!({"layer": l["id"], "path": path})).unwrap();
+            assert_eq!(got["uid"], n["uid"], "path {path} on layer {}", l["name"]);
+            checked += 1;
+        }
+    }
+    assert!(checked > 20, "{checked}");
+}
+
+#[test]
+fn comp_settings_anchor_start_timecode_renderer() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "A", "width": 100, "height": 100, "duration": 2.0})).unwrap();
+    let l = s.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("prop.addKey", json!({"layer": l, "path": "transform/position", "time": 0.0, "value": [10, 20]})).unwrap();
+    let pos = |s: &Session| {
+        let pr = s.active_comp().unwrap().layer(crate::project::LayerId(l)).unwrap().props.prop("transform/position").unwrap().clone();
+        pr.keys[0].value.components()
+    };
+    // Center anchor: grow by 100x50 → shift by half.
+    s.execute("comp.settings", json!({"width": 200, "height": 150})).unwrap();
+    assert_eq!(pos(&s)[..2], [60.0, 45.0]);
+    // Top-left anchor: no shift. Bottom-right: full shift.
+    s.execute("comp.settings", json!({"width": 300, "anchor": 0})).unwrap();
+    assert_eq!(pos(&s)[..2], [60.0, 45.0]);
+    s.execute("comp.settings", json!({"width": 200, "height": 100, "anchor": 8})).unwrap();
+    assert_eq!(pos(&s)[..2], [-40.0, -5.0]);
+    s.execute("comp.settings", json!({"startTimecode": "0:00:01:00", "renderer": "advanced3D"})).unwrap();
+    let c = s.active_comp().unwrap();
+    assert_eq!(c.display_start, c.frame_rate.tick_of(30));
+    assert_eq!(c.renderer, crate::project::Renderer::Advanced3D);
+}
+
+/// `advanced3D` is a value of `renderer`, not a key: comp.new / comp.settings don't advertise it
+/// in their schemas and reject it as unknown instead of ignoring it (#177).
+#[test]
+fn renderer_values_are_not_parameter_keys() {
+    let mut s = Session::default();
+    for (id, p) in [("comp.new", json!({"name": "A"})), ("comp.settings", json!({}))] {
+        let spec = crate::command_specs().iter().find(|c| c.id == id).unwrap();
+        let keys = crate::commands::accepted_params(spec.params).unwrap();
+        assert!(keys.contains(&"renderer".to_string()) && !keys.contains(&"advanced3D".to_string()), "{id}: {keys:?}");
+        let mut bad = p.clone();
+        bad["advanced3D"] = json!(true);
+        let e = s.execute_checked(id, bad).unwrap_err().to_string();
+        assert!(e.contains("unknown parameter(s) `advanced3D`"), "{id}: {e}");
+        let mut good = p;
+        good["renderer"] = json!("advanced3D");
+        s.execute_checked(id, good).unwrap();
+        assert_eq!(s.active_comp().unwrap().renderer, crate::project::Renderer::Advanced3D, "{id}");
+        s.execute("comp.renderer", json!({"renderer": "classic3d"})).unwrap();
+    }
+}
+
+#[test]
+fn comp_rejects_zero_and_negative_frame_rates() {
+    let mut s = Session::default();
+    for fps in [0.0, -30.0, 0.0001] {
+        assert!(s.execute("comp.new", json!({"frameRate": fps})).is_err(), "{fps}");
+    }
+    s.execute("comp.new", json!({"frameRate": 30, "duration": 1})).unwrap();
+    assert!(s.execute("comp.settings", json!({"frameRate": 0})).is_err());
+    assert_eq!(s.active_comp().unwrap().frame_rate, crate::time::FrameRate::FPS_30);
+}
+
+#[test]
+fn render_queue_add_accepts_documented_settings_when_checked() {
+    let mut s = demo();
+    let r = s.execute_checked(
+        "renderQueue.add",
+        json!({"format": "gif", "output": "/tmp/x.gif", "resolution": "quarter", "timeSpan": "custom", "start": 0.0, "end": 0.5, "quality": "draft", "loop": true}),
+    );
+    // Without an exporter the add itself still succeeds (rendering is what needs one).
+    assert!(r.is_ok(), "{r:?}");
+    assert!(s.execute_checked("renderQueue.add", json!({"bogus": 1})).is_err());
+}
+
+#[test]
+fn new_text_rejects_malformed_positions_without_creating_a_layer() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "C", "width": 64, "height": 64, "duration": 1})).unwrap();
+    for position in [json!([]), json!([10]), json!(["x", 20]), json!([null, 20])] {
+        let err = s.execute("layer.newText", json!({"text": "Hello", "position": position})).unwrap_err();
+        assert!(err.to_string().contains("position: [x, y]"), "{err}");
+        assert!(s.active_comp().unwrap().layers.is_empty());
+    }
+    s.execute("layer.newText", json!({"name": "Valid", "text": "Hello", "position": [10, 20]})).unwrap();
+    assert_eq!(s.active_comp().unwrap().layers[0].props.prop("transform/position").unwrap().value, effectcraft_keyframe::Value::Vec3([10.0, 20.0, 0.0]));
+    s.execute("layer.newText", json!({"text": "No explicit position"})).unwrap();
+    assert_eq!(s.active_comp().unwrap().layers.len(), 2);
+}
+
+/// The active comp and the open comp tabs are saved with the project and restored on open (#748).
+#[test]
+fn reopening_a_project_restores_its_active_comp() {
+    use effectcraft_project::ItemId;
+    let dir = std::env::temp_dir().join(format!("ec-test-748-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("view.ecproj").to_string_lossy().to_string();
+    let mut s = Session::default();
+    let a = s.execute("comp.new", json!({"name": "CompA"})).unwrap()["comp"].as_u64().unwrap();
+    let b = s.execute("comp.new", json!({"name": "CompB"})).unwrap()["comp"].as_u64().unwrap();
+    let c = s.execute("comp.new", json!({"name": "CompC"})).unwrap()["comp"].as_u64().unwrap();
+    s.execute("comp.open", json!({"comp": "CompB"})).unwrap();
+    s.state.open_comps.retain(|id| id.0 != c);
+    s.execute("file.saveAs", json!({"path": path})).unwrap();
+    let mut s2 = Session::default();
+    s2.execute("file.open", json!({"path": path})).unwrap();
+    assert_eq!(s2.state.active_comp, Some(ItemId(b)));
+    assert_eq!(s2.state.open_comps, vec![ItemId(a), ItemId(b)]);
+    assert!(!s2.is_dirty());
+
+    // A file from before the view was saved opens on its first comp, as it always did.
+    let text = std::fs::read_to_string(&path).unwrap();
+    let mut old: serde_json::Value = serde_json::from_str(&text).unwrap();
+    let obj = old.as_object_mut().unwrap();
+    obj.remove("activeComp");
+    obj.remove("openComps");
+    std::fs::write(&path, serde_json::to_string_pretty(&old).unwrap()).unwrap();
+    let mut s3 = Session::default();
+    s3.execute("file.open", json!({"path": path})).unwrap();
+    assert_eq!((s3.state.active_comp, s3.state.open_comps.clone()), (Some(ItemId(a)), vec![ItemId(a)]));
+
+    // Ids that no longer name a comp (edited by hand, or written by another tool) fall back.
+    obj_set(&mut old, json!(999), json!([999, b, "x"]));
+    std::fs::write(&path, serde_json::to_string_pretty(&old).unwrap()).unwrap();
+    let mut s4 = Session::default();
+    s4.execute("file.open", json!({"path": path})).unwrap();
+    assert_eq!((s4.state.active_comp, s4.state.open_comps.clone()), (Some(ItemId(b)), vec![ItemId(b)]));
+    obj_set(&mut old, json!(999), json!([]));
+    std::fs::write(&path, serde_json::to_string_pretty(&old).unwrap()).unwrap();
+    let mut s5 = Session::default();
+    s5.execute("file.open", json!({"path": path})).unwrap();
+    assert_eq!((s5.state.active_comp, s5.state.open_comps.clone()), (Some(ItemId(a)), vec![ItemId(a)]));
+
+    // XML copies carry it too.
+    let xml = dir.join("view.ecprojx").to_string_lossy().to_string();
+    s.execute("file.saveAs", json!({"path": xml})).unwrap();
+    let mut s6 = Session::default();
+    s6.execute("file.open", json!({"path": xml})).unwrap();
+    assert_eq!(s6.state.active_comp, Some(ItemId(b)));
+    let _ = std::fs::remove_dir_all(dir);
+
+    fn obj_set(v: &mut serde_json::Value, active: serde_json::Value, open: serde_json::Value) {
+        let o = v.as_object_mut().unwrap();
+        o.insert("activeComp".into(), active);
+        o.insert("openComps".into(), open);
+    }
+}
+
+/// Layer times are saved as exact ticks and read back unchanged, and each comp reopens at the
+/// current time it was saved at, not at 0, where a layer starting later shows nothing (#1714).
+#[test]
+fn reopening_a_project_restores_layer_times_and_current_time() {
+    use effectcraft_project::ItemId;
+    use effectcraft_time::{FrameRate, Tick};
+    let dir = std::env::temp_dir().join(format!("ec-test-1714-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("times.ecproj").to_string_lossy().to_string();
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "C", "width": 108, "height": 192, "duration": 60})).unwrap();
+    s.execute("layer.newSolid", json!({"name": "crown"})).unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let comp = std::sync::Arc::make_mut(&mut s.project).comp_mut(cid).unwrap();
+    comp.frame_rate = FrameRate::FPS_59_94;
+    // The layer from the issue: 34f, 315f and 3033f at 59.94 fps.
+    let l = comp.layers.first_mut().unwrap();
+    (l.start_time, l.in_point, l.out_point) = (Tick(144_086_342_400), Tick(1_334_917_584_000), Tick(12_853_349_308_800));
+    s.execute("time.set", json!({"time": 6.0})).unwrap();
+    let t = s.time();
+    // A second comp keeps its own time.
+    let b = ItemId(s.execute("comp.new", json!({"name": "B"})).unwrap()["comp"].as_u64().unwrap());
+    s.execute("time.set", json!({"time": 2.0})).unwrap();
+    let tb = s.time();
+    s.execute("comp.open", json!({"comp": "C"})).unwrap();
+    s.execute("file.saveAs", json!({"path": path})).unwrap();
+
+    let mut s2 = Session::default();
+    s2.execute("file.open", json!({"path": path})).unwrap();
+    let l = s2.project.comp(cid).unwrap().layers.first().unwrap();
+    assert_eq!((l.start_time, l.in_point, l.out_point), (Tick(144_086_342_400), Tick(1_334_917_584_000), Tick(12_853_349_308_800)));
+    assert_eq!((s2.time(), s2.state.times.get(&b).copied()), (t, Some(tb)));
+    assert!(l.in_point <= s2.time() && s2.time() < l.out_point, "the layer shows at the reopened time");
+    assert!(!s2.is_dirty());
+
+    // Hand-edited times past the end or before the start land on the last or first frame.
+    let mut file: serde_json::Value = serde_json::from_str(&std::fs::read_to_string(&path).unwrap()).unwrap();
+    file["compTimes"] = json!({cid.0.to_string(): i64::MAX, b.0.to_string(): -5});
+    std::fs::write(&path, file.to_string()).unwrap();
+    let mut s3 = Session::default();
+    s3.execute("file.open", json!({"path": path})).unwrap();
+    let c = s3.project.comp(cid).unwrap();
+    assert_eq!(s3.time(), c.frame_rate.snap_nearest(c.duration - c.frame_duration()));
+    assert_eq!(s3.time(), c.frame_rate.snap_nearest(c.duration - c.frame_duration()));
+    assert_eq!(s3.state.times.get(&b).copied(), Some(Tick::ZERO));
+}
diff --git a/crates/engine/src/tests_settings.rs b/crates/engine/src/tests/settings.rs
similarity index 99%
rename from crates/engine/src/tests_settings.rs
rename to crates/engine/src/tests/settings.rs
index c35d4f3a4..81bed3c43 100644
--- a/crates/engine/src/tests_settings.rs
+++ b/crates/engine/src/tests/settings.rs
@@ -71,6 +71,14 @@ fn prefs_migrate_old_layout_and_keep_unknown_keys() {
     assert_eq!(Prefs::from_json("not json"), Prefs::default());
 }
 
+#[test]
+fn prefs_migrate_old_disk_cache_default() {
+    // The old 100 GB default becomes 20 GB; a size the user chose stays (#2551).
+    assert_eq!(Prefs::from_json(r#"{"version": 2, "disk": {"diskCacheMaxGb": 100}}"#).disk.disk_cache_max_gb, 20);
+    assert_eq!(Prefs::from_json(r#"{"version": 2, "disk": {"diskCacheMaxGb": 50}}"#).disk.disk_cache_max_gb, 50);
+    assert_eq!(Prefs::from_json(r#"{"version": 3, "disk": {"diskCacheMaxGb": 100}}"#).disk.disk_cache_max_gb, 100);
+}
+
 #[test]
 fn prefs_set_validates_keys_types_and_ranges() {
     let mut p = Prefs::default();
@@ -181,7 +189,7 @@ fn every_schema_key_exists_and_docs_list_the_todo_settings() {
             assert!(ids.contains(&page), "{path:?} opens unknown page {page}");
         }
     }
-    let docs = include_str!("../../../docs/preferences.md");
+    let docs = include_str!("../../../../docs/preferences.md");
     for k in crate::prefs::todo_keys() {
         assert!(docs.contains(&format!("`{k}`")), "docs/preferences.md must list the not-yet-wired setting `{k}`");
     }
diff --git a/crates/engine/src/tests_shortcut_cmds.rs b/crates/engine/src/tests/shortcut_cmds.rs
similarity index 100%
rename from crates/engine/src/tests_shortcut_cmds.rs
rename to crates/engine/src/tests/shortcut_cmds.rs
diff --git a/crates/engine/src/tests_stubs.rs b/crates/engine/src/tests/stubs.rs
similarity index 100%
rename from crates/engine/src/tests_stubs.rs
rename to crates/engine/src/tests/stubs.rs
diff --git a/crates/engine/src/tests_styles.rs b/crates/engine/src/tests/styles.rs
similarity index 100%
rename from crates/engine/src/tests_styles.rs
rename to crates/engine/src/tests/styles.rs
diff --git a/crates/engine/src/tests_tail.rs b/crates/engine/src/tests/tail.rs
similarity index 100%
rename from crates/engine/src/tests_tail.rs
rename to crates/engine/src/tests/tail.rs
diff --git a/crates/engine/src/tests_text.rs b/crates/engine/src/tests/text.rs
similarity index 99%
rename from crates/engine/src/tests_text.rs
rename to crates/engine/src/tests/text.rs
index 84f88fd33..3980c7bb5 100644
--- a/crates/engine/src/tests_text.rs
+++ b/crates/engine/src/tests/text.rs
@@ -198,7 +198,7 @@ fn cached_text_presets_keep_the_catalog_and_application_independent() {
 #[ignore = "warm text-preset listing benchmark"]
 fn text_preset_listing_benchmark() {
     let old = || {
-        let v: serde_json::Value = serde_json::from_str(include_str!("../presets/text_animators.json")).unwrap();
+        let v: serde_json::Value = serde_json::from_str(include_str!("../../presets/text_animators.json")).unwrap();
         let presets = v["presets"].as_array().unwrap().clone();
         presets.iter().map(|p| (p["id"].as_str().unwrap().to_string(), p["name"].as_str().unwrap().to_string())).collect::<Vec<_>>()
     };
diff --git a/crates/engine/src/tests_text_edit.rs b/crates/engine/src/tests/text_edit.rs
similarity index 100%
rename from crates/engine/src/tests_text_edit.rs
rename to crates/engine/src/tests/text_edit.rs
diff --git a/crates/engine/src/tests_3d.rs b/crates/engine/src/tests/three_d.rs
similarity index 100%
rename from crates/engine/src/tests_3d.rs
rename to crates/engine/src/tests/three_d.rs
diff --git a/crates/engine/src/tests_timeline.rs b/crates/engine/src/tests/timeline.rs
similarity index 100%
rename from crates/engine/src/tests_timeline.rs
rename to crates/engine/src/tests/timeline.rs
diff --git a/crates/engine/src/tests_timeline_interchange.rs b/crates/engine/src/tests/timeline_interchange.rs
similarity index 100%
rename from crates/engine/src/tests_timeline_interchange.rs
rename to crates/engine/src/tests/timeline_interchange.rs
diff --git a/crates/engine/src/tests_track.rs b/crates/engine/src/tests/track.rs
similarity index 100%
rename from crates/engine/src/tests_track.rs
rename to crates/engine/src/tests/track.rs
diff --git a/crates/engine/src/tests_vector_import.rs b/crates/engine/src/tests/vector_import.rs
similarity index 95%
rename from crates/engine/src/tests_vector_import.rs
rename to crates/engine/src/tests/vector_import.rs
index 63513b910..9cfb94ecc 100644
--- a/crates/engine/src/tests_vector_import.rs
+++ b/crates/engine/src/tests/vector_import.rs
@@ -2,7 +2,7 @@
 
 use effectcraft_color::BlendMode;
 use effectcraft_keyframe::Value as KV;
-use effectcraft_project::{ItemKind, LayerSource, MaskMode};
+use effectcraft_project::{Comp, ItemKind, Layer, LayerSource, MaskMode};
 use effectcraft_psd::write::*;
 use effectcraft_psd::{DValue, Descriptor, Rect};
 use serde_json::json;
@@ -74,22 +74,8 @@ pub(crate) fn sample_psd() -> Vec<u8> {
     write(&d)
 }
 
-#[test]
-fn psd_imports_as_composition() {
-    let path = tmp("sample.psd");
-    std::fs::write(&path, sample_psd()).unwrap();
-    let mut s = Session::default();
-    let r = s.execute_checked("file.import", json!({"paths": [path], "importAs": "composition"})).unwrap();
-    assert_eq!(r["errors"], json!([]), "{r}");
-    let cid = effectcraft_project::ItemId(r["comps"][0].as_u64().unwrap());
-    assert_eq!(s.state.active_comp, Some(cid));
-    assert_eq!(s.project.item(cid).unwrap().name, "sample");
-    let c = s.project.comp(cid).unwrap().clone();
-    assert_eq!((c.width, c.height), (120, 80));
-    let names: Vec<&str> = c.layers.iter().map(|l| l.name.as_str()).collect();
-    assert_eq!(names, ["Title", "Hue Shift", "Vector Masked", "Clipped", "Base", "Group A", "Background"]);
-    // Text layer: editable text, positioned at the type origin.
-    let title = &c.layers[0];
+/// Text layer: editable text, positioned at the type origin.
+fn assert_title_layer(title: &Layer) {
     assert!(matches!(title.source, LayerSource::Text));
     let Some(KV::Text(doc)) = title.props.prop("text/sourceText").map(|p| p.value.clone()) else { panic!("text") };
     assert_eq!(doc.text, "Hello PSD");
@@ -97,14 +83,18 @@ fn psd_imports_as_composition() {
     assert_eq!(doc.font, "Inter");
     assert_eq!(doc.style, "Bold");
     assert_eq!(title.props.prop("transform/position").unwrap().value.as_vec2(), [8.0, 70.0]);
-    // Adjustment layer with Hue/Saturation.
-    let hue = &c.layers[1];
+}
+
+/// Adjustment layer with Hue/Saturation.
+fn assert_hue_layer(hue: &Layer) {
     assert!(hue.switches.adjustment);
     let fx = hue.effects().unwrap().groups().next().unwrap();
     assert_eq!(fx.get("hue").unwrap().value.as_f64(), 40.0);
     assert_eq!(fx.get("saturation").unwrap().value.as_f64(), 10.0);
-    // Vector mask → mask; Stroke style.
-    let vm = &c.layers[2];
+}
+
+/// Vector mask → mask; Stroke style.
+fn assert_vector_mask_layer(vm: &Layer) {
     let m = vm.masks().unwrap().groups().next().unwrap();
     assert!(matches!(m.kind, effectcraft_project::GroupKind::Mask { mode: MaskMode::Add, .. }));
     let Some(KV::Path(p)) = m.get("path").map(|p| p.value.clone()) else { panic!("mask path") };
@@ -113,19 +103,23 @@ fn psd_imports_as_composition() {
     let st = vm.props.group("layerStyles/stroke").unwrap();
     assert_eq!(st.get("size").unwrap().value.as_f64(), 2.0);
     assert_eq!(st.get("position").unwrap().value, KV::Enum(1));
-    // Clipped → preserve transparency; opacity and blend mode.
+}
+
+/// Clipped → preserve transparency (opacity, blend mode); drop shadow.
+fn assert_clipped_and_shadow(c: &Comp) {
     let clipped = &c.layers[3];
     assert!(clipped.preserve_transparency);
     assert_eq!(clipped.blend_mode, BlendMode::Screen);
     assert!((clipped.props.prop("transform/opacity").unwrap().value.as_f64() - 128.0 / 255.0 * 100.0).abs() < 1e-9);
-    // Drop shadow.
     let ds = c.layers[4].props.group("layerStyles/dropShadow").unwrap();
     assert_eq!(ds.get("distance").unwrap().value.as_f64(), 9.0);
     assert_eq!(ds.get("angle").unwrap().value.as_f64(), 45.0);
     assert_eq!(ds.get("useGlobalLight").unwrap().value, KV::Bool(false));
     assert_eq!(ds.get("opacity").unwrap().value.as_f64(), 60.0);
-    // Group → collapsed precomp (pass through) with its layers.
-    let g = &c.layers[5];
+}
+
+/// Group → collapsed precomp (pass through) with its layers; footage items name their Photoshop layer.
+fn assert_group_precomp(s: &Session, g: &Layer) {
     assert!(g.switches.collapse);
     let LayerSource::Comp { item } = g.source else { panic!("precomp") };
     let inner = s.project.comp(item).unwrap();
@@ -140,6 +134,27 @@ fn psd_imports_as_composition() {
     assert_eq!((sl.name.as_str(), sl.layer_size), ("Masked Square", false));
     assert_eq!((f.width, f.height), (120, 80));
     assert_eq!(s.project.item(item).unwrap().name, "Masked Square/sample.psd");
+}
+
+#[test]
+fn psd_imports_as_composition() {
+    let path = tmp("sample.psd");
+    std::fs::write(&path, sample_psd()).unwrap();
+    let mut s = Session::default();
+    let r = s.execute_checked("file.import", json!({"paths": [path], "importAs": "composition"})).unwrap();
+    assert_eq!(r["errors"], json!([]), "{r}");
+    let cid = effectcraft_project::ItemId(r["comps"][0].as_u64().unwrap());
+    assert_eq!(s.state.active_comp, Some(cid));
+    assert_eq!(s.project.item(cid).unwrap().name, "sample");
+    let c = s.project.comp(cid).unwrap().clone();
+    assert_eq!((c.width, c.height), (120, 80));
+    let names: Vec<&str> = c.layers.iter().map(|l| l.name.as_str()).collect();
+    assert_eq!(names, ["Title", "Hue Shift", "Vector Masked", "Clipped", "Base", "Group A", "Background"]);
+    assert_title_layer(&c.layers[0]);
+    assert_hue_layer(&c.layers[1]);
+    assert_vector_mask_layer(&c.layers[2]);
+    assert_clipped_and_shadow(&c);
+    assert_group_precomp(&s, &c.layers[5]);
     // One undo step removes everything.
     s.execute("edit.undo", json!({})).unwrap();
     assert!(s.project.comp(cid).is_none());
diff --git a/crates/engine/src/tests_viewer.rs b/crates/engine/src/tests/viewer.rs
similarity index 100%
rename from crates/engine/src/tests_viewer.rs
rename to crates/engine/src/tests/viewer.rs
diff --git a/crates/engine/src/tests_crypto_pick.rs b/crates/engine/src/tests_crypto_pick.rs
deleted file mode 100644
index 799027c7e..000000000
--- a/crates/engine/src/tests_crypto_pick.rs
+++ /dev/null
@@ -1,336 +0,0 @@
-//! `effect.pickCryptomatte` / `effect.cryptomatteAt` (#473): the Cryptomatte eyedropper reads the
-//! aux channels the effect renders from (footage at its source time, a 3D precomp's generated
-//! pass) and edits the Selection text in one undo step.
-
-use std::sync::Arc;
-
-use effectcraft_project::{Footage, FootageKind, ItemId};
-use effectcraft_raster::channels3d::{crypto_float, crypto_hash};
-use effectcraft_raster::{AuxChannels, Image};
-use effectcraft_time::{FrameRate, Tick};
-use serde_json::{Value, json};
-
-use crate::Session;
-use crate::render::FootageSource;
-
-const COMMA: &str = "Green, \"Glossy\"";
-
-/// 8 × 4 footage with a 16 × 8 Cryptomatte (two aux pixels per layer pixel). Layer pixels in x:
-/// 0-1 `left` (0.6) over `right` (0.4); 2-3 `left` (0.3) under the comma name (0.7), ranks out of
-/// order; 4-5 `star*`; 6 an ID missing from the manifest; 7 a 0.5 / 0.5 tie of `left` and
-/// `right`. Rows 3+ are empty. From 1 s of source time `late` replaces columns 0-1.
-struct Crypto;
-
-fn aux_at(t: Tick) -> AuxChannels {
-    let (w, h) = (16usize, 8usize);
-    let mut planes = vec![vec![0.0f32; w * h]; 4];
-    for (i, x) in (0..w * h).map(|i| (i, i % w)).filter(|(i, _)| i / w < 6) {
-        let late = if t >= Tick::from_seconds_f64(1.0) { "late" } else { "left" };
-        let (a, ca, b, cb) = match x {
-            0..4 => (late, 0.6, "right", 0.4),
-            4..8 => ("left", 0.3, COMMA, 0.7),
-            8..12 => ("star*", 1.0, "", 0.0),
-            12..14 => ("ghost", 1.0, "", 0.0),
-            _ => ("left", 0.5, "right", 0.5),
-        };
-        for (k, v) in [crypto_float(crypto_hash(a)), ca, crypto_float(crypto_hash(b)), cb].into_iter().enumerate() {
-            planes[k][i] = v;
-        }
-    }
-    let mut aux = AuxChannels::new(w as u32, h as u32, 1.0);
-    for (k, c) in ["R", "G", "B", "A"].iter().enumerate() {
-        aux.channels.push((format!("CryptoObject00.{c}"), planes[k].clone()));
-    }
-    aux.manifests = vec![("CryptoObject".into(), ["left", "right", "late", COMMA, "star*"].iter().map(|n| (n.to_string(), crypto_hash(n))).collect())];
-    aux
-}
-
-impl FootageSource for Crypto {
-    fn frame(&self, _: ItemId, f: &Footage, _: Tick) -> Option<Arc<Image>> {
-        Some(Arc::new(Image::new(f.width, f.height)))
-    }
-    fn aux(&self, _: ItemId, _: &Footage, t: Tick) -> Option<Arc<AuxChannels>> {
-        Some(Arc::new(aux_at(t)))
-    }
-}
-
-struct Probe;
-impl crate::Importer for Probe {
-    fn probe(&self, path: &str) -> Result<Footage, String> {
-        let duration = Tick::from_seconds_f64(2.0);
-        // A half-size proxy of the EXR.
-        let (width, height) = if path.contains("proxy") { (4, 2) } else { (8, 4) };
-        Ok(Footage {
-            path: path.into(),
-            kind: FootageKind::Video,
-            width,
-            height,
-            has_video: true,
-            frame_rate: FrameRate::from_f64(24.0),
-            duration,
-            ..Default::default()
-        })
-    }
-}
-
-fn session() -> Session {
-    let mut s = Session { footage: Arc::new(Crypto), importer: Some(Arc::new(Probe)), ..Default::default() };
-    let item = s.execute("file.import", json!({"paths": ["/renders/crypto.exr"]})).unwrap()["items"][0].clone();
-    s.execute("comp.new", json!({"name": "C", "width": 8, "height": 4, "frameRate": 24, "duration": 2})).unwrap();
-    s.execute("layer.addItem", json!({"item": item})).unwrap();
-    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
-    s
-}
-
-fn pick(s: &mut Session, x: f64, mode: &str) -> Value {
-    s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": x, "y": 1.5, "mode": mode})).unwrap()
-}
-
-fn selection(s: &Session) -> String {
-    let l = &s.active_comp().unwrap().layers[0];
-    let g = l.effects().unwrap().groups().next().unwrap();
-    match &g.prop("selection").unwrap().value {
-        effectcraft_keyframe::Value::Str(t) => t.clone(),
-        v => panic!("{v:?}"),
-    }
-}
-
-#[test]
-fn picks_replace_add_and_remove_in_one_undo_step_each() {
-    let mut s = session();
-    let steps = s.history.undo.len();
-    let r = pick(&mut s, 0.5, "replace");
-    assert_eq!((r["name"].as_str(), r["selection"].as_str(), r["changed"].as_bool()), (Some("left"), Some("left"), Some(true)), "{r}");
-    assert_eq!(r["hash"], format!("{:08x}", crypto_hash("left")));
-    assert_eq!(s.history.undo.len(), steps + 1);
-    // The highest coverage wins even when it is not rank 0; the name is quoted.
-    assert_eq!(pick(&mut s, 2.5, "add")["selection"], r#"left, "Green, \"Glossy\"""#);
-    // Adding it again changes nothing and leaves no undo step.
-    let again = pick(&mut s, 3.5, "add");
-    assert_eq!((again["changed"].as_bool(), s.history.undo.len()), (Some(false), steps + 2));
-    // A `*` name and an unnamed ID go in as hashes; a tie goes to rank 0.
-    pick(&mut s, 4.5, "add");
-    assert_eq!(pick(&mut s, 6.5, "add")["selection"], format!(r#"left, "Green, \"Glossy\"", <{:08x}>, <{:08x}>"#, crypto_hash("star*"), crypto_hash("ghost")));
-    assert_eq!(s.execute("effect.cryptomatteAt", json!({"effect": 1, "x": 7.5, "y": 0.5})).unwrap()["name"], "left");
-    let r = pick(&mut s, 0.0, "remove");
-    assert_eq!(r["selection"], format!(r#""Green, \"Glossy\"", <{:08x}>, <{:08x}>"#, crypto_hash("star*"), crypto_hash("ghost")));
-    assert_eq!(r["selected"], false);
-    // The text parses back to exactly the picked IDs.
-    let manifest = aux_at(Tick::ZERO).manifests[0].1.clone();
-    let got = effectcraft_effects::selection_hashes(&selection(&s), Some(&manifest));
-    assert_eq!(got, [COMMA, "star*", "ghost"].map(crypto_hash));
-    assert_eq!(s.history.undo.len(), steps + 5);
-    s.execute("edit.undo", json!({})).unwrap();
-    assert!(selection(&s).starts_with("left, "), "{}", selection(&s));
-    pick(&mut s, 2.0, "replace");
-    assert_eq!(selection(&s), r#""Green, \"Glossy\"""#);
-    // The same selection with other spacing: no change, no undo step.
-    s.execute_checked("prop.set", json!({"path": "effects/#1/selection", "value": " \"Green, \\\"Glossy\\\"\" "})).unwrap();
-    let n = s.history.undo.len();
-    assert_eq!((pick(&mut s, 2.0, "replace")["changed"].as_bool(), s.history.undo.len()), (Some(false), n));
-}
-
-#[test]
-fn bad_points_layers_and_modes_are_errors_and_change_nothing() {
-    let mut s = session();
-    let at = |s: &mut Session, x: f64, y: f64| s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": x, "y": y}));
-    for (x, y) in [(-0.1, 1.0), (8.0, 1.0), (1.0, 4.0), (1.0, 3.5), (1e300, -1e300)] {
-        assert!(at(&mut s, x, y).is_err(), "{x},{y}");
-        assert_eq!(s.execute("effect.cryptomatteAt", json!({"effect": 1, "x": x, "y": y})).unwrap(), Value::Null);
-    }
-    assert!(s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 1, "y": 1, "mode": "toggle"})).is_err());
-    assert!(s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 1})).is_err());
-    for scale in [0.0, -1.0, 2.0] {
-        assert!(s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 1, "y": 1, "scale": scale})).is_err(), "{scale}");
-    }
-    s.execute_checked("effect.apply", json!({"effect": "Gaussian Blur"})).unwrap();
-    assert!(s.execute_checked("effect.pickCryptomatte", json!({"effect": 2, "x": 1, "y": 1})).is_err(), "not a Cryptomatte effect");
-    assert_eq!(selection(&s), "");
-    // A layer without aux channels.
-    s.execute("layer.newSolid", json!({"name": "S"})).unwrap();
-    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
-    let e = s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 1, "y": 1})).unwrap_err().to_string();
-    assert!(e.contains("no Cryptomatte channels"), "{e}");
-    // An expression-driven Selection would ignore the edit.
-    let mut s = session();
-    s.execute_checked("prop.setExpression", json!({"path": "effects/#1/selection", "expression": "\"right\""})).unwrap();
-    assert!(s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 1, "y": 1})).is_err());
-    assert_eq!(s.execute("effect.cryptomatteAt", json!({"effect": 1, "x": 1, "y": 1})).unwrap()["selected"], false);
-}
-
-/// The pick reads the frame the render shows: Time Remap's source time, not the layer time.
-#[test]
-fn time_remap_picks_the_shown_source_frame() {
-    let mut s = session();
-    assert_eq!(pick(&mut s, 0.5, "replace")["name"], "left");
-    s.execute_checked("layer.enableTimeRemap", json!({})).unwrap();
-    s.execute_checked("prop.set", json!({"path": "timeRemap", "value": 1.5})).unwrap();
-    assert_eq!(pick(&mut s, 0.5, "replace")["name"], "late");
-}
-
-/// A precomp of a 3D comp: the generated CryptoObject pass names its layers.
-#[test]
-fn picks_on_a_precomp_of_a_3d_comp() {
-    let mut s = Session::default();
-    s.execute("comp.new", json!({"name": "Outer", "width": 40, "height": 20, "frameRate": 24, "duration": 1})).unwrap();
-    let l = s.execute("layer.newSolid", json!({"name": "Red, Ball", "width": 40, "height": 20})).unwrap()["layer"].clone();
-    s.execute("layer.setSwitch", json!({"layers": [l], "switch": "threeD", "value": true})).unwrap();
-    s.execute("layer.precompose", json!({"layers": [l], "name": "Inner"})).unwrap();
-    s.execute("layer.select", json!({"layers": [s.active_comp().unwrap().layers[0].id.0]})).ok();
-    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
-    let r = s.execute_checked("effect.pickCryptomatte", json!({"effect": 1, "x": 20, "y": 10})).unwrap();
-    assert_eq!((r["name"].as_str(), r["selection"].as_str()), (Some("Red, Ball"), Some("\"Red, Ball\"")), "{r}");
-}
-
-/// The matte the rendered Cryptomatte effect gives the picked ID at the buffer pixel under
-/// `{x, y}`: the pick has to name the ID the effect's own input buffer samples there.
-fn rendered_matte_of_pick(s: &mut Session, x: f64, y: f64, scale: f64) -> (String, f32) {
-    let r = s.execute_checked("effect.pickCryptomatte", json!({"effect": "Cryptomatte", "x": x, "y": y, "scale": scale, "mode": "replace"})).unwrap();
-    let fx = s.active_comp().unwrap().layers[0].effects().unwrap().groups().position(|g| g.match_id == "ec.3d.cryptomatte").unwrap() + 1;
-    s.execute_checked("prop.set", json!({"path": format!("effects/#{fx}/matteOnly"), "value": true})).unwrap();
-    let (cid, comp) = (s.active_comp_id().unwrap(), s.active_comp().unwrap());
-    let layer = &comp.layers[0];
-    let ctx = effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time: Tick::ZERO, expr: None, footage: None };
-    let buf = s.renderer(effectcraft_render::RenderOpts { scale, ..Default::default() }).content_buf(&ctx, layer).unwrap();
-    let (px, py) = buf.to_px([x, y]);
-    let m = buf.img.get(px.floor() as i64, py.floor() as i64)[0];
-    (r["name"].as_str().unwrap_or("?").to_string(), m)
-}
-
-/// Between 3/4 and full resolution footage keeps its native pixels: at 0.8 the effect samples
-/// layer pixel 2 (the comma name, 0.7) at x = 2.2, not the 0.8-grid pixel snapped back to 1.
-#[test]
-fn pick_at_scale_0_8_matches_the_native_buffer_the_effect_renders() {
-    let mut s = session();
-    let (name, m) = rendered_matte_of_pick(&mut s, 2.2, 1.5, 0.8);
-    assert!(m >= 0.5, "picked {name:?}, but the render gives it matte {m} there");
-    assert_eq!(name, COMMA);
-}
-
-/// A half-size proxy renders a buffer at 0.5 layer pixels per pixel even at full resolution:
-/// x = 6.5 lies in buffer pixel 3, which samples layer x = 7 (the `left` / `right` tie).
-#[test]
-fn pick_on_a_proxy_matches_the_proxy_sized_buffer() {
-    let mut s = session();
-    let item = *s.project.items.iter().find(|(_, i)| matches!(i.kind, effectcraft_project::ItemKind::Footage(_))).unwrap().0;
-    s.execute("file.setProxy", json!({"item": item.0, "path": "/renders/crypto_proxy.exr"})).unwrap();
-    let (name, m) = rendered_matte_of_pick(&mut s, 6.5, 1.5, 1.0);
-    assert!(m >= 0.5, "picked {name:?}, but the render gives it matte {m} there");
-    assert_eq!(name, "left");
-}
-
-/// 1920-px footage with `left` up to x = 120 and `right` after it, and a 104-px proxy.
-struct Edge;
-impl FootageSource for Edge {
-    fn frame(&self, _: ItemId, f: &Footage, _: Tick) -> Option<Arc<Image>> {
-        Some(Arc::new(Image::new(f.width, f.height)))
-    }
-    fn aux(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<AuxChannels>> {
-        let (w, h) = (1920usize, 40usize);
-        let mut aux = AuxChannels::new(w as u32, h as u32, 1.0);
-        let ids = (0..w * h).map(|i| crypto_float(crypto_hash(if i % w < 120 { "left" } else { "right" }))).collect();
-        aux.channels = vec![("CryptoObject00.R".into(), ids), ("CryptoObject00.G".into(), vec![1.0; w * h])];
-        aux.manifests = vec![("CryptoObject".into(), ["left", "right"].iter().map(|n| (n.to_string(), crypto_hash(n))).collect())];
-        Some(Arc::new(aux))
-    }
-}
-
-/// Proxy buffer pixel 6's centre maps to layer x = 6.5 / (104 / 1920): 120.0 by division, but
-/// 119.99999999999999 by the reciprocal the effect multiplies with. The pick must agree.
-#[test]
-fn pick_maps_pixel_centres_bit_exactly_as_the_effect() {
-    let mut s = Session { footage: Arc::new(Edge), ..Default::default() };
-    let at = |path: &str, width| Footage {
-        path: path.into(),
-        kind: FootageKind::Video,
-        width,
-        height: 40,
-        has_video: true,
-        frame_rate: FrameRate::from_f64(24.0),
-        duration: Tick::from_seconds_f64(2.0),
-        ..Default::default()
-    };
-    s.importer = Some(Arc::new(EdgeProbe(at("/renders/edge.exr", 1920), at("/renders/edge_proxy.exr", 104))));
-    let item = s.execute("file.import", json!({"paths": ["/renders/edge.exr"]})).unwrap()["items"][0].clone();
-    s.execute("comp.new", json!({"name": "C", "width": 1920, "height": 40, "frameRate": 24, "duration": 2})).unwrap();
-    s.execute("layer.addItem", json!({"item": item})).unwrap();
-    s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
-    s.execute("file.setProxy", json!({"item": item, "path": "/renders/edge_proxy.exr"})).unwrap();
-    let (name, m) = rendered_matte_of_pick(&mut s, 118.0, 5.0, 1.0);
-    assert_eq!((name.as_str(), m), ("left", 1.0));
-}
-
-struct EdgeProbe(Footage, Footage);
-impl crate::Importer for EdgeProbe {
-    fn probe(&self, path: &str) -> Result<Footage, String> {
-        Ok(if path.contains("proxy") { self.1.clone() } else { self.0.clone() })
-    }
-}
-
-/// Footage whose decoded frames are `num / den` of the probed size (a file re-rendered at another
-/// resolution, a relinked file): the render stretches them over the layer.
-struct OffNominal(u32, u32);
-impl FootageSource for OffNominal {
-    fn frame(&self, _: ItemId, f: &Footage, _: Tick) -> Option<Arc<Image>> {
-        Some(Arc::new(Image::new(f.width * self.0 / self.1, f.height * self.0 / self.1)))
-    }
-    fn aux(&self, _: ItemId, _: &Footage, t: Tick) -> Option<Arc<AuxChannels>> {
-        Some(Arc::new(aux_at(t)))
-    }
-}
-
-/// Points along rows `ys` where the picked ID isn't lit in the rendered matte under the point.
-fn mismatches(s: &mut Session, scales: &[f64], xs: impl Iterator<Item = f64> + Clone, ys: &[f64]) -> Vec<String> {
-    let mut bad = vec![];
-    for &scale in scales {
-        for (x, &y) in ys.iter().flat_map(|y| xs.clone().map(move |x| (x, y))) {
-            if s.execute("effect.cryptomatteAt", json!({"effect": "Cryptomatte", "x": x, "y": y, "scale": scale})).unwrap().is_null() {
-                continue;
-            }
-            let (name, m) = rendered_matte_of_pick(s, x, y, scale);
-            if m < 0.5 {
-                bad.push(format!("scale {scale} ({x:.2}, {y}): picked {name:?}, matte {m}"));
-            }
-        }
-    }
-    bad
-}
-
-const PREVIEW_SCALES: [f64; 7] = [1.0, 0.8, 0.75, 0.74, 0.5, 0.33, 0.25];
-
-/// The pick follows the decoded frame's real size, not the footage's nominal one.
-#[test]
-fn pick_matches_the_render_when_frames_decode_off_nominal_size() {
-    for (num, den) in [(2, 1), (1, 2), (3, 4)] {
-        let mut s = Session { footage: Arc::new(OffNominal(num, den)), importer: Some(Arc::new(Probe)), ..Default::default() };
-        let item = s.execute("file.import", json!({"paths": ["/renders/crypto.exr"]})).unwrap()["items"][0].clone();
-        s.execute("comp.new", json!({"name": "C", "width": 8, "height": 4, "frameRate": 24, "duration": 2})).unwrap();
-        s.execute("layer.addItem", json!({"item": item})).unwrap();
-        s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
-        let bad = mismatches(&mut s, &PREVIEW_SCALES, (0..80).map(|i| i as f64 * 0.1 + 0.05), &[0.3, 1.7, 2.6]);
-        assert!(bad.is_empty(), "decode {num}/{den}: {} mismatches:\n{}", bad.len(), bad.join("\n"));
-    }
-}
-
-/// A precomp of a 3D comp, with and without Preserve Resolution (drawn at full size below full
-/// resolution), behind a disabled effect: the pick names the ID the rendered matte shows.
-#[test]
-fn pick_matches_the_render_on_precomps_with_and_without_preserve_resolution() {
-    for preserve in [false, true] {
-        let mut s = Session::default();
-        s.execute("comp.new", json!({"name": "Outer", "width": 40, "height": 20, "frameRate": 24, "duration": 2})).unwrap();
-        let a = s.execute("layer.newSolid", json!({"name": "A", "width": 40, "height": 20})).unwrap()["layer"].clone();
-        let b = s.execute("layer.newSolid", json!({"name": "B", "width": 7, "height": 20})).unwrap()["layer"].clone();
-        s.execute_checked("prop.set", json!({"layer": b, "path": "transform/position", "value": [3.5, 10, -10]})).unwrap();
-        s.execute("layer.setSwitch", json!({"layers": [a, b], "switch": "threeD", "value": true})).unwrap();
-        s.execute("layer.precompose", json!({"layers": [a, b], "name": "Inner"})).unwrap();
-        let inner = *s.project.items.iter().find(|(_, i)| i.name == "Inner").unwrap().0;
-        s.execute_checked("comp.settings", json!({"comp": inner.0, "preserveResolution": preserve})).unwrap();
-        s.execute("layer.select", json!({"layers": [s.active_comp().unwrap().layers[0].id.0]})).ok();
-        s.execute_checked("effect.apply", json!({"effect": "Gaussian Blur"})).unwrap();
-        s.execute_checked("effect.toggle", json!({"effect": 1, "value": false})).unwrap();
-        s.execute_checked("effect.apply", json!({"effect": "Cryptomatte"})).unwrap();
-        let bad = mismatches(&mut s, &PREVIEW_SCALES, (0..93).map(|i| i as f64 * 0.15 + 0.05), &[10.0]);
-        assert!(bad.is_empty(), "preserve {preserve}: {} mismatches:\n{}", bad.len(), bad.join("\n"));
-    }
-}
diff --git a/crates/export/src/encode.rs b/crates/export/src/encode.rs
index e4a45561d..e48bc4bb1 100644
--- a/crates/export/src/encode.rs
+++ b/crates/export/src/encode.rs
@@ -26,9 +26,49 @@ pub(crate) struct Packet {
     pub(crate) cto: i32,
 }
 
-pub(crate) trait VideoEncoder {
+/// A frame for the movie encoder: 8-bit RGBA, or 8-bit 4:2:0 planes already converted on the
+/// render threads (for encoders whose [`VideoEncoder::takes_yuv420`] is true).
+pub(crate) enum Pixels {
+    Rgba(Vec<u8>),
+    Yuv420(Yuv420),
+}
+
+/// BT.709 limited-range 8-bit 4:2:0 planes ([`rgba_to_yuv420`], or Y then U and V from the
+/// accelerator).
+pub(crate) enum Yuv420 {
+    Planes { y: Vec<u8>, u: Vec<u8>, v: Vec<u8> },
+    Packed(Vec<u8>),
+}
+
+impl Yuv420 {
+    fn from_rgba(rgba: &[u8], w: usize, h: usize) -> Yuv420 {
+        let (mut y, mut u, mut v) = (vec![], vec![], vec![]);
+        rgba_to_yuv420(rgba, w, h, &mut y, &mut u, &mut v);
+        Yuv420::Planes { y, u, v }
+    }
+    fn slices(&self, w: usize, h: usize) -> (&[u8], &[u8], &[u8]) {
+        match self {
+            Yuv420::Planes { y, u, v } => (y, u, v),
+            Yuv420::Packed(p) => {
+                let (cw, ch) = (w.div_ceil(2), h.div_ceil(2));
+                let (y, uv) = p.split_at(w * h);
+                let (u, v) = uv.split_at(cw * ch);
+                (y, u, v)
+            }
+        }
+    }
+}
+
+pub(crate) trait VideoEncoder: Send {
     fn sample_entry(&self) -> SampleEntry;
     fn encode(&mut self, rgba: &[u8], index: u64) -> Result<Vec<Packet>>;
+    /// Whether frames should come as [`Pixels::Yuv420`] (converted while other frames render).
+    fn takes_yuv420(&self) -> bool {
+        false
+    }
+    fn encode_yuv420(&mut self, _frame: &Yuv420, _index: u64) -> Result<Vec<Packet>> {
+        Err(ExportError::Unsupported("this encoder takes RGBA frames".into()))
+    }
     fn flush(&mut self) -> Result<Vec<Packet>>;
     /// Edit-list media start (B-frame delay) in the track timescale.
     fn media_start(&self) -> Option<i64> {
@@ -73,9 +113,22 @@ impl VideoEncoder for H264 {
         SampleEntry::avc(cfg, self.w as u16, self.h as u16)
     }
     fn encode(&mut self, rgba: &[u8], index: u64) -> Result<Vec<Packet>> {
-        rgba_to_yuv420(rgba, self.w as usize, self.h as usize, &mut self.y, &mut self.u, &mut self.v);
-        let cw = (self.w as usize).div_ceil(2);
-        let frame = filmcraft_h264enc::YuvFrame { y: &self.y, u: &self.u, v: &self.v, y_stride: self.w as usize, uv_stride: cw };
+        let (mut y, mut u, mut v) = (std::mem::take(&mut self.y), std::mem::take(&mut self.u), std::mem::take(&mut self.v));
+        rgba_to_yuv420(rgba, self.w as usize, self.h as usize, &mut y, &mut u, &mut v);
+        let planes = Yuv420::Planes { y, u, v };
+        let r = self.encode_yuv420(&planes, index);
+        if let Yuv420::Planes { y, u, v } = planes {
+            (self.y, self.u, self.v) = (y, u, v);
+        }
+        r
+    }
+    fn takes_yuv420(&self) -> bool {
+        true
+    }
+    fn encode_yuv420(&mut self, p: &Yuv420, index: u64) -> Result<Vec<Packet>> {
+        let (w, cw) = (self.w as usize, (self.w as usize).div_ceil(2));
+        let (y, u, v) = p.slices(w, self.h as usize);
+        let frame = filmcraft_h264enc::YuvFrame { y, u, v, y_stride: w, uv_stride: cw };
         let ps = self.enc.try_encode(&frame, index as i64 * self.rate.den).map_err(enc)?;
         Ok(self.packets(ps))
     }
@@ -88,33 +141,7 @@ impl VideoEncoder for H264 {
     }
 }
 
-/// BT.709 limited-range 8-bit 4:2:0 from RGBA8 (2×2 chroma average; alpha ignored).
-pub(crate) fn rgba_to_yuv420(rgba: &[u8], w: usize, h: usize, y: &mut Vec<u8>, u: &mut Vec<u8>, v: &mut Vec<u8>) {
-    let (cw, ch) = (w.div_ceil(2), h.div_ceil(2));
-    y.resize(w * h, 0);
-    u.resize(cw * ch, 0);
-    v.resize(cw * ch, 0);
-    y.par_chunks_mut(w * 2).zip(u.par_chunks_mut(cw).zip(v.par_chunks_mut(cw))).enumerate().for_each(|(cy, (yr, (ur, vr)))| {
-        let rows = yr.len() / w;
-        let mut acc = vec![(0f32, 0f32, 0f32); cw];
-        for dy in 0..rows {
-            let src = &rgba[(cy * 2 + dy) * w * 4..][..w * 4];
-            for x in 0..w {
-                let (r, g, b) = (src[x * 4] as f32 / 255.0, src[x * 4 + 1] as f32 / 255.0, src[x * 4 + 2] as f32 / 255.0);
-                let l = 0.2126 * r + 0.7152 * g + 0.0722 * b;
-                yr[dy * w + x] = (16.0 + 219.0 * l).round().clamp(1.0, 254.0) as u8;
-                let a = &mut acc[x / 2];
-                a.0 += (b - l) / 1.8556;
-                a.1 += (r - l) / 1.5748;
-                a.2 += 1.0;
-            }
-        }
-        for (cx, a) in acc.iter().enumerate() {
-            ur[cx] = (128.0 + 224.0 * a.0 / a.2).round().clamp(1.0, 254.0) as u8;
-            vr[cx] = (128.0 + 224.0 * a.1 / a.2).round().clamp(1.0, 254.0) as u8;
-        }
-    });
-}
+pub(crate) use effectcraft_raster::yuv::rgba_to_yuv420;
 
 // ---------------------------------------------------------------- ProRes
 
@@ -265,15 +292,41 @@ pub(crate) async fn movie(job: &Cx<'_>, comp: &Comp, w: u32, h: u32, st: &mut St
     };
     let brand = if matches!(fmt, OutputFormat::ProRes | OutputFormat::Uncompressed) { Brand::Mov } else { Brand::Mp4 };
     let batch = batch_size();
-    let render = |_: u64, img: effectcraft_raster::Image| -> Vec<u8> { job.pixels(&img, comp, channels, w, h) };
+    let yuv = venc.takes_yuv420();
+    let render = |_: u64, img: effectcraft_raster::Image| -> Pixels {
+        let px = job.pixels(&img, comp, channels, w, h);
+        if yuv { Pixels::Yuv420(Yuv420::from_rgba(&px, w as usize, h as usize)) } else { Pixels::Rgba(px) }
+    };
+    // H.264 frames the accelerator can convert itself come back as planes (12 MB instead of
+    // 133 MB of RGBA f32 read back at 4K); everything else renders and converts as before.
+    // Deferred readbacks (a browser worker) keep their pass-based path: no blocking there.
+    let gpu_yuv = yuv && channels == Channels::Rgb && !job.deferred();
+    let batch_frames = async |ks: Vec<u64>| -> Vec<Pixels> {
+        if gpu_yuv { job.h264_frames(comp, ks, w, h, |p| Pixels::Yuv420(Yuv420::Packed(p)), render) } else { job.frames(comp, ks, render).await }
+    };
+    let encode = |venc: &mut Box<dyn VideoEncoder>, px: &Pixels, index: u64| match px {
+        Pixels::Rgba(rgba) => venc.encode(rgba, index),
+        Pixels::Yuv420(planes) => venc.encode_yuv420(planes, index),
+    };
+
+    let beside = crate::pipeline::Beside::shared();
+    let total = st.total;
 
     // Encode the first batch before creating tracks: encoders finalise their config on frame 1.
-    let first_end = batch.min(st.total);
-    let first: Vec<Vec<u8>> = job.frames(comp, (0..first_end).collect(), render).await;
-    let mut pending = Vec::new();
-    for (k, px) in first.iter().enumerate() {
-        pending.extend(venc.encode(px, k as u64)?);
-    }
+    // Each batch encodes while the next one renders.
+    let first_end = batch.min(total);
+    let first: Vec<Pixels> = batch_frames((0..first_end).collect()).await;
+    let next_end = (first_end + batch).min(total);
+    let (pending, mut ready) = job
+        .beside(beside, batch_frames((first_end..next_end).collect()), || -> Result<Vec<Packet>> {
+            let mut pending = Vec::new();
+            for (k, px) in first.iter().enumerate() {
+                pending.extend(encode(&mut venc, px, k as u64)?);
+            }
+            Ok(pending)
+        })
+        .await?;
+    let pending = pending?;
     drop(first);
     st.advance(first_end)?;
 
@@ -351,19 +404,25 @@ pub(crate) async fn movie(job: &Cx<'_>, comp: &Comp, w: u32, h: u32, st: &mut St
         }
         Ok(())
     };
-    let total = st.total;
     let frame_end_time = |k: u64| -> Tick { if k >= total { span_end } else { job.settings.frame_time(comp, k) } };
     write_video(&mut mux, pending)?;
     write_audio_until(&mut mux, frame_end_time(first_end), &mut cursor)?;
     let mut i = first_end;
     while i < total {
         let end = (i + batch).min(total);
-        let frames: Vec<Vec<u8>> = job.frames(comp, (i..end).collect(), render).await;
-        for (k, px) in frames.iter().enumerate() {
-            let ps = venc.encode(px, i + k as u64)?;
-            write_video(&mut mux, ps)?;
-        }
-        write_audio_until(&mut mux, frame_end_time(end), &mut cursor)?;
+        let next_end = (end + batch).min(total);
+        let frames = std::mem::take(&mut ready);
+        let (done, next) = job
+            .beside(beside, batch_frames((end..next_end).collect()), || -> Result<()> {
+                for (k, px) in frames.iter().enumerate() {
+                    let ps = encode(&mut venc, px, i + k as u64)?;
+                    write_video(&mut mux, ps)?;
+                }
+                write_audio_until(&mut mux, frame_end_time(end), &mut cursor)
+            })
+            .await?;
+        done?;
+        ready = next;
         st.advance(end - i)?;
         i = end;
     }
@@ -382,8 +441,74 @@ pub(crate) async fn movie(job: &Cx<'_>, comp: &Comp, w: u32, h: u32, st: &mut St
 
 #[cfg(test)]
 mod tests {
+    use effectcraft_raster::yuv::{UNIT8, round_pos};
+
     use super::*;
 
+    /// The conversion as first written (per-pixel division and `f32::round`).
+    fn yuv420_reference(rgba: &[u8], w: usize, h: usize) -> (Vec<u8>, Vec<u8>, Vec<u8>) {
+        let (cw, ch) = (w.div_ceil(2), h.div_ceil(2));
+        let (mut y, mut u, mut v) = (vec![0u8; w * h], vec![0u8; cw * ch], vec![0u8; cw * ch]);
+        for cy in 0..ch {
+            let mut acc = vec![(0f32, 0f32, 0f32); cw];
+            for row in cy * 2..(cy * 2 + 2).min(h) {
+                for x in 0..w {
+                    let s = &rgba[(row * w + x) * 4..];
+                    let (r, g, b) = (s[0] as f32 / 255.0, s[1] as f32 / 255.0, s[2] as f32 / 255.0);
+                    let l = 0.2126 * r + 0.7152 * g + 0.0722 * b;
+                    y[row * w + x] = (16.0 + 219.0 * l).round().clamp(1.0, 254.0) as u8;
+                    let a = &mut acc[x / 2];
+                    a.0 += (b - l) / 1.8556;
+                    a.1 += (r - l) / 1.5748;
+                    a.2 += 1.0;
+                }
+            }
+            for (cx, a) in acc.iter().enumerate() {
+                u[cy * cw + cx] = (128.0 + 224.0 * a.0 / a.2).round().clamp(1.0, 254.0) as u8;
+                v[cy * cw + cx] = (128.0 + 224.0 * a.1 / a.2).round().clamp(1.0, 254.0) as u8;
+            }
+        }
+        (y, u, v)
+    }
+
+    #[test]
+    fn round_pos_is_round() {
+        for i in 0..2_000_000u32 {
+            let v = i as f32 * 0.000_25;
+            assert_eq!(round_pos(v).to_bits(), v.round().to_bits(), "{v}");
+            let n = f32::from_bits(v.to_bits().wrapping_sub(1)).max(0.0);
+            assert_eq!(round_pos(n).to_bits(), n.round().to_bits(), "{n}");
+        }
+        for k in 0..1024u32 {
+            for v in [k as f32 + 0.5, f32::from_bits((k as f32 + 0.5).to_bits() - 1), f32::from_bits((k as f32 + 0.5).to_bits() + 1)] {
+                assert_eq!(round_pos(v), v.round(), "{v}");
+            }
+        }
+        for (i, u) in UNIT8.iter().enumerate() {
+            assert_eq!(u.to_bits(), (i as f32 / 255.0).to_bits());
+        }
+    }
+
+    #[test]
+    fn yuv420_matches_the_reference() {
+        // Every 8-bit level in every channel, odd sizes, and pseudo-random pixels.
+        for (w, h) in [(1, 1), (2, 2), (3, 5), (17, 9), (64, 33)] {
+            let mut rgba = vec![0u8; w * h * 4];
+            let mut seed = (w * 31 + h) as u32;
+            for (i, b) in rgba.iter_mut().enumerate() {
+                seed = seed.wrapping_mul(1_664_525).wrapping_add(1_013_904_223);
+                *b = if i % 7 == 0 { (i / 4 % 256) as u8 } else { (seed >> 24) as u8 };
+            }
+            let (mut y, mut u, mut v) = (vec![], vec![], vec![]);
+            rgba_to_yuv420(&rgba, w, h, &mut y, &mut u, &mut v);
+            assert_eq!((y, u, v), yuv420_reference(&rgba, w, h), "{w}x{h}");
+        }
+        let grey: Vec<u8> = (0..=255u8).flat_map(|g| [g, g, g, 255, g, 255 - g, g / 2, 255]).collect();
+        let (mut y, mut u, mut v) = (vec![], vec![], vec![]);
+        rgba_to_yuv420(&grey, 512, 1, &mut y, &mut u, &mut v);
+        assert_eq!((y, u, v), yuv420_reference(&grey, 512, 1));
+    }
+
     #[test]
     fn yuv_of_primaries() {
         let rgba = [255u8, 255, 255, 255, 0, 0, 0, 255, 255, 0, 0, 255, 0, 255, 0, 255];
diff --git a/crates/export/src/lib.rs b/crates/export/src/lib.rs
index 9af195204..7ea28b571 100644
--- a/crates/export/src/lib.rs
+++ b/crates/export/src/lib.rs
@@ -270,7 +270,7 @@ async fn sequence(cx: &Cx<'_>, comp: &Comp, w: u32, h: u32, st: &mut State<'_>)
                 let path = sequence_path(cx.path, f0 + k as i64);
                 // Encode in memory first: the storage hook decides where it fits.
                 let mut buf = std::io::Cursor::new(Vec::new());
-                write_still(cx, &mut buf, fmt, &img, comp, channels, w, h, cx.output.quality)?;
+                write_still(cx, &mut buf, &img, comp, StillOutput { format: fmt, channels, size: (w, h), quality: cx.output.quality })?;
                 let data = buf.into_inner();
                 let path = cx.place(&path, data.len() as u64);
                 let mut f = cx.create(&path)?;
@@ -287,18 +287,15 @@ async fn sequence(cx: &Cx<'_>, comp: &Comp, w: u32, h: u32, st: &mut State<'_>)
     Ok(Report { path: sequence_path(cx.path, f0), frames: 0, width: w, height: h, seconds: 0.0, bytes, audio: false, log: None, overflow: vec![] })
 }
 
-#[allow(clippy::too_many_arguments)]
-fn write_still<W: std::io::Write + std::io::Seek>(
-    cx: &Cx,
-    file: &mut W,
-    fmt: OutputFormat,
-    img: &Image,
-    comp: &Comp,
+struct StillOutput {
+    format: OutputFormat,
     channels: Channels,
-    w: u32,
-    h: u32,
+    size: (u32, u32),
     quality: u8,
-) -> Result<()> {
+}
+
+fn write_still<W: std::io::Write + std::io::Seek>(cx: &Cx, file: &mut W, img: &Image, comp: &Comp, output: StillOutput) -> Result<()> {
+    let StillOutput { format: fmt, channels, size: (w, h), quality } = output;
     use image::{ExtendedColorType, ImageEncoder, ImageFormat};
     match fmt {
         OutputFormat::ExrSequence => {
diff --git a/crates/export/src/pipeline.rs b/crates/export/src/pipeline.rs
index 9fd131474..ae52d3478 100644
--- a/crates/export/src/pipeline.rs
+++ b/crates/export/src/pipeline.rs
@@ -91,6 +91,24 @@ pub(crate) fn map_frames_while<I: Send, T: Send>(
     out
 }
 
+/// Threads that encode one batch of frames while the next renders ([`Cx::frames_beside`]).
+/// Their own pool: the encoder's parallel steps (colour conversion) would otherwise queue behind
+/// the render's work in the global pool. `None` where threads can't be started (a browser
+/// without them): encoding and rendering then take turns.
+pub(crate) struct Beside(Option<rayon::ThreadPool>);
+
+impl Beside {
+    fn new() -> Beside {
+        Beside(rayon::ThreadPoolBuilder::new().thread_name(|i| format!("export-encode-{i}")).build().ok())
+    }
+
+    /// The process's encode threads, started by the first movie export and shared by all.
+    pub fn shared() -> &'static Beside {
+        static SHARED: std::sync::OnceLock<Beside> = std::sync::OnceLock::new();
+        SHARED.get_or_init(Beside::new)
+    }
+}
+
 /// A job being exported: the job, the project with the Render Settings overrides applied, the
 /// job's layer cache and per-frame timing for the render log.
 pub(crate) struct Cx<'a> {
@@ -214,6 +232,52 @@ impl<'a> Cx<'a> {
         map_frames_while(ks, self.gpu_cap(), gpu_live, |k| self.frame(comp, k), f)
     }
 
+    /// [`Cx::frames`] for `ks` while `encode` runs beside them on `beside`'s threads, so the
+    /// render threads don't wait for the (largely sequential) encoder of the previous batch.
+    /// With deferred readbacks, or where no encode thread could be started, `encode` runs first.
+    #[cfg(test)]
+    pub async fn frames_beside<T: Send, A: Send>(
+        &self,
+        beside: &Beside,
+        comp: &Comp,
+        ks: Vec<u64>,
+        f: impl Fn(u64, Image) -> T + Sync + Send,
+        encode: impl FnOnce() -> A + Send,
+    ) -> crate::Result<(A, Vec<T>)> {
+        self.beside(beside, self.frames(comp, ks, f), encode).await
+    }
+
+    /// Run `encode` on `beside`'s threads while `frames` renders the next batch. With deferred
+    /// readbacks, or where no encode thread could be started, `encode` runs first.
+    pub async fn beside<T: Send, A: Send>(
+        &self,
+        beside: &Beside,
+        frames: impl std::future::Future<Output = Vec<T>>,
+        encode: impl FnOnce() -> A + Send,
+    ) -> crate::Result<(A, Vec<T>)> {
+        match &beside.0 {
+            Some(pool) if !self.deferred() => {
+                let mut done = None;
+                let frames = pool.in_place_scope(|s| {
+                    s.spawn(|_| done = Some(std::panic::catch_unwind(std::panic::AssertUnwindSafe(encode))));
+                    effectcraft_render::passes::block_on(frames)
+                });
+                match done {
+                    Some(Ok(a)) => Ok((a, frames)),
+                    Some(Err(panic)) => {
+                        let why = panic.downcast_ref::<&str>().map(|s| s.to_string()).or_else(|| panic.downcast_ref::<String>().cloned()).unwrap_or_default();
+                        Err(crate::ExportError::Encode(format!("the encoder stopped unexpectedly: {why}")))
+                    }
+                    None => Err(crate::ExportError::Encode("the encoder stopped unexpectedly".into())),
+                }
+            }
+            _ => {
+                let a = encode();
+                Ok((a, frames.await))
+            }
+        }
+    }
+
     /// GPU frames rendered at once (#879), decided once per batch: with a GPU accelerator every
     /// frame in flight holds its own working textures, so a whole batch rendered at once can
     /// exhaust VRAM (or shared memory, which crashes instead of falling back). `None` when the
@@ -252,6 +316,63 @@ impl<'a> Cx<'a> {
         img
     }
 
+    /// Output frame `i` as the H.264 export's 4:2:0 planes at `w`×`h`, rendered and converted
+    /// by the accelerator ([`effectcraft_render::Accelerator::comp_frame_yuv420`]). Only for
+    /// frames that need nothing done after the render (progressive, at the project's depth, no
+    /// crop or resize, rendered at exactly `w`×`h`). `None`: render it with [`Cx::frame`].
+    pub fn yuv420_frame(&self, comp: &Comp, i: u64, w: u32, h: u32) -> Option<Vec<u8>> {
+        if self.deferred() {
+            return None;
+        }
+        let FrameSample::Progressive(t) = self.job.settings.sample(comp, i) else { return None };
+        let depth = self.job.settings.color_depth;
+        if depth != ColorDepth::Current && depth.resolve(self.project.settings.bit_depth).levels().is_some() {
+            return None;
+        }
+        let om = self.job.output;
+        let scale = self.job.settings.resolution.clamp(0.01, 4.0);
+        let size = |n: u32| ((n as f64 * scale).round() as u32).max(1);
+        if om.resize.enabled || (size(comp.width), size(comp.height)) != (w, h) || om.crop.edges(w, h, scale) != (0, 0, 0, 0) {
+            return None;
+        }
+        let t0 = Instant::now();
+        let r = self.renderer();
+        let planes = r.active_accel()?.comp_frame_yuv420(&r, self.job.comp, t, comp.background)?;
+        let (cw, ch) = (w.div_ceil(2) as usize, h.div_ceil(2) as usize);
+        if planes.len() != w as usize * h as usize + 2 * cw * ch {
+            return None;
+        }
+        if let Some(ft) = &self.frame_times {
+            ft.lock().unwrap_or_else(|e| e.into_inner()).push((i, t0.elapsed().as_secs_f64()));
+        }
+        Some(planes)
+    }
+
+    /// Output frames `ks` for the H.264 encoder: the accelerator's planes
+    /// ([`Cx::yuv420_frame`]) where it can, otherwise `fallback` of the frame rendered as usual.
+    pub(crate) fn h264_frames<T: Send>(
+        &self,
+        comp: &Comp,
+        ks: Vec<u64>,
+        w: u32,
+        h: u32,
+        planes: impl Fn(Vec<u8>) -> T + Sync + Send,
+        fallback: impl Fn(u64, Image) -> T + Sync + Send,
+    ) -> Vec<T> {
+        // As in `frames`: once the GPU has stopped for good, the rest render in parallel.
+        let gpu_live = || self.job.accel.is_none_or(|a| a.available());
+        map_frames_while(
+            ks,
+            self.gpu_cap(),
+            gpu_live,
+            |k| self.yuv420_frame(comp, k, w, h).ok_or_else(|| self.frame(comp, k)),
+            |k, r| match r {
+                Ok(p) => planes(p),
+                Err(img) => fallback(k, img),
+            },
+        )
+    }
+
     /// Output Module ▸ Crop, then Resize.
     fn crop_resize(&self, img: Image) -> Image {
         let om = self.job.output;
@@ -706,6 +827,45 @@ mod tests {
         assert!(stats.hits >= 9, "{stats:?}");
     }
 
+    #[test]
+    fn frames_render_beside_the_encoder() {
+        use effectcraft_project::render_queue::{OutputFormat, OutputModule, RenderSettings};
+        use effectcraft_render::NoFootage;
+        use effectcraft_time::FrameRate;
+        let mut p = Project::default();
+        let comp = Comp::new(32, 16, FrameRate::FPS_25, Tick::from_seconds_f64(1.0));
+        let cid = p.add_item("Comp", effectcraft_color::Label::Sandstone, None, effectcraft_project::ItemKind::Comp(comp.into()));
+        let (settings, output) = (RenderSettings::default(), OutputModule::for_format(OutputFormat::H264));
+        let job = Job {
+            project: &p,
+            footage: &NoFootage,
+            expr: None,
+            accel: None,
+            comp: cid,
+            settings: &settings,
+            output: &output,
+            path: "/c/out.mp4",
+            sink: None,
+            nested_switches: true,
+            options: Default::default(),
+        };
+        let cx = Cx::new(&job);
+        let comp = cx.comp().unwrap();
+        use effectcraft_render::passes::block_on;
+        let want = block_on(cx.frames(comp, (0..6).collect(), |k, img| (k, img.width, img.height)));
+        // On threads of their own, and taking turns (no threads): the same frames, in order.
+        for beside in [Beside::shared(), &Beside(None)] {
+            let (a, frames) = block_on(cx.frames_beside(beside, comp, (0..6).collect(), |k, img| (k, img.width, img.height), || 7)).unwrap();
+            assert_eq!((a, &frames), (7, &want));
+        }
+        // A panicking encoder fails the export instead of taking the render thread down.
+        let r = block_on(cx.frames_beside(Beside::shared(), comp, vec![0], |k, _| k, || -> u32 { panic!("encoder bug") }));
+        match r {
+            Err(crate::ExportError::Encode(e)) => assert!(e.contains("encoder bug"), "{e}"),
+            other => panic!("{:?}", other.map(|(a, f)| (a, f.len()))),
+        }
+    }
+
     #[test]
     fn interleave_takes_alternate_lines() {
         let a = Image::filled(3, 4, [1.0, 0.0, 0.0, 1.0]);
diff --git a/crates/export/tests/it/h264_gpu_yuv.rs b/crates/export/tests/it/h264_gpu_yuv.rs
new file mode 100644
index 000000000..59e670779
--- /dev/null
+++ b/crates/export/tests/it/h264_gpu_yuv.rs
@@ -0,0 +1,180 @@
+//! H.264 export with an accelerator that converts frames to 4:2:0 itself
+//! (`Accelerator::comp_frame_yuv420`): the file is the same as the CPU conversion's, and frames
+//! the accelerator can't take (odd sizes, crop) fall back to the RGBA path.
+
+use std::path::{Path, PathBuf};
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+use effectcraft_color::Label;
+use effectcraft_export::render_queue::{OutputFormat, OutputModule, RenderSettings, TimeSpan};
+use effectcraft_export::{Job, export};
+use effectcraft_project::{Comp, ItemId, ItemKind, LayerSource, Project, Solid, build};
+use effectcraft_raster::Image;
+use effectcraft_render::{Accelerator, NoFootage, Renderer};
+use effectcraft_time::{FrameRate, Tick};
+
+/// Renders on the CPU; converts to 4:2:0 with the export's own function when `yuv` is set.
+/// `deferred`: claims deferred readbacks (a browser worker's GPU), whose frames render in passes.
+/// `stop_after`: the device stops for good after that many planes (`available` turns false).
+struct Fake {
+    yuv: bool,
+    yuv_frames: AtomicUsize,
+    deferred: bool,
+    stop_after: usize,
+    /// Frames asking for planes right now, and the most at once after the stop.
+    asking: AtomicUsize,
+    most_after_stop: AtomicUsize,
+}
+
+impl Fake {
+    fn new(yuv: bool, deferred: bool, stop_after: usize) -> Self {
+        Fake { yuv, yuv_frames: AtomicUsize::new(0), deferred, stop_after, asking: AtomicUsize::new(0), most_after_stop: AtomicUsize::new(0) }
+    }
+}
+
+impl Accelerator for Fake {
+    fn name(&self) -> String {
+        "fake".into()
+    }
+    fn comp_frame(&self, r: &Renderer, comp: ItemId, t: Tick) -> Option<Image> {
+        Some(r.comp_frame_cpu(comp, t))
+    }
+    fn comp_frame_yuv420(&self, r: &Renderer, comp: ItemId, t: Tick, bg: [f32; 3]) -> Option<Vec<u8>> {
+        if !self.yuv {
+            return None;
+        }
+        if self.yuv_frames.fetch_add(1, Ordering::SeqCst) >= self.stop_after {
+            self.yuv_frames.fetch_sub(1, Ordering::SeqCst);
+            // Stopped: every frame still asks first, so asks that overlap are frames rendering at once.
+            let now = self.asking.fetch_add(1, Ordering::SeqCst) + 1;
+            self.most_after_stop.fetch_max(now, Ordering::SeqCst);
+            std::thread::sleep(std::time::Duration::from_millis(30));
+            self.asking.fetch_sub(1, Ordering::SeqCst);
+            return None;
+        }
+        Some(effectcraft_raster::yuv::yuv420_over(&r.comp_frame_cpu(comp, t), bg))
+    }
+    fn available(&self) -> bool {
+        self.yuv_frames.load(Ordering::SeqCst) < self.stop_after
+    }
+    fn miss_gate(&self) -> Option<std::sync::Arc<std::sync::atomic::AtomicBool>> {
+        self.deferred.then(Default::default)
+    }
+    fn supports_effect(&self, _id: &str) -> bool {
+        false
+    }
+    fn effects(&self, _chain: &[effectcraft_render::FxStep], _buf: &effectcraft_effects::Buf, _levels: Option<f32>) -> Option<effectcraft_effects::Buf> {
+        None
+    }
+}
+
+fn out_dir(name: &str) -> PathBuf {
+    let d = Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/export").join(name);
+    let _ = std::fs::remove_dir_all(&d);
+    std::fs::create_dir_all(&d).expect("mkdir");
+    d
+}
+
+fn project() -> (Project, ItemId) {
+    let mut p = Project::default();
+    p.settings.gpu_acceleration = true;
+    let mut comp = Comp::new(64, 48, FrameRate::new(10, 1), Tick::from_seconds_f64(0.6));
+    comp.background = [0.1, 0.1, 0.4];
+    let sid = p.add_item("Red", Label::Red, None, ItemKind::Solid(Solid { color: [1.0, 0.2, 0.0], width: 30, height: 20, pixel_aspect: 1.0 }));
+    let mut l = build::layer(&mut p, &comp, "Red", LayerSource::Solid { item: sid }, (30, 20), None);
+    l.in_point = comp.frame_rate.tick_of(2);
+    comp.layers.push(l);
+    let cid = p.add_item("Comp 1", Label::Sandstone, None, ItemKind::Comp(comp.into()));
+    (p, cid)
+}
+
+fn run(p: &Project, cid: ItemId, accel: Option<&dyn Accelerator>, s: &RenderSettings, path: &Path) -> Vec<u8> {
+    let om = OutputModule { bitrate_kbps: 4000, ..OutputModule::for_format(OutputFormat::H264) };
+    let path = path.to_string_lossy().to_string();
+    let job = Job {
+        project: p,
+        footage: &NoFootage,
+        expr: None,
+        accel,
+        comp: cid,
+        settings: s,
+        output: &om,
+        path: &path,
+        sink: None,
+        options: Default::default(),
+        nested_switches: true,
+    };
+    export(&job, &mut |_| true).expect("export");
+    std::fs::read(&path).expect("read")
+}
+
+#[test]
+fn accelerator_planes_encode_like_the_cpu_conversion() {
+    let d = out_dir("h264-gpu-yuv");
+    let (mut p, cid) = project();
+    // Across more than one 16-frame batch so the second batch renders beside the encoder.
+    p.comp_mut(cid).unwrap().duration = Tick::from_seconds_f64(2.0);
+    let s = RenderSettings { time_span: TimeSpan::LengthOfComp, ..Default::default() };
+    let yuv = Fake::new(true, false, usize::MAX);
+    let rgba = Fake::new(false, false, usize::MAX);
+    let yuv_mp4 = d.join("yuv.mp4");
+    let a = run(&p, cid, Some(&yuv), &s, &yuv_mp4);
+    let b = run(&p, cid, Some(&rgba), &s, &d.join("rgba.mp4"));
+    let c = run(&p, cid, None, &s, &d.join("cpu.mp4"));
+    assert_eq!(yuv.yuv_frames.load(Ordering::SeqCst), 20, "every frame came from the accelerator");
+    assert!(a == b && b == c, "the three files differ");
+    let f = effectcraft_media::probe(&yuv_mp4).expect("probe yuv.mp4");
+    assert_eq!((f.width, f.height), (64, 48));
+    assert_eq!(f.frame_rate.frame_at(f.duration - Tick(1)) + 1, 20);
+    let pool = effectcraft_media::MediaPool::new();
+    for k in 0..20 {
+        let img = pool.frame_at(&f, f.frame_rate.tick_of(k)).expect("decode frame");
+        assert_eq!((img.width, img.height), (64, 48));
+    }
+}
+
+#[test]
+fn frames_the_accelerator_cannot_take_fall_back_to_rgba() {
+    let d = out_dir("h264-gpu-yuv-fallback");
+    let (p, cid) = project();
+    let base = RenderSettings { time_span: TimeSpan::LengthOfComp, ..Default::default() };
+    // Renders at 62×47, encodes at 62×46 (the codec size): planes of the render would not fit.
+    let odd = RenderSettings { resolution: 31.0 / 32.0, ..base.clone() };
+    let yuv = Fake::new(true, false, usize::MAX);
+    let a = run(&p, cid, Some(&yuv), &odd, &d.join("yuv.mp4"));
+    let c = run(&p, cid, None, &odd, &d.join("cpu.mp4"));
+    assert_eq!(yuv.yuv_frames.load(Ordering::SeqCst), 0);
+    assert!(a == c);
+}
+
+/// With deferred readbacks the export keeps rendering frames in passes (`Cx::frames`), never
+/// through the blocking per-frame path the planes use.
+#[test]
+fn deferred_accelerators_keep_the_pass_based_path() {
+    let d = out_dir("h264-gpu-yuv-deferred");
+    let (p, cid) = project();
+    let s = RenderSettings { time_span: TimeSpan::LengthOfComp, ..Default::default() };
+    let deferred = Fake::new(true, true, usize::MAX);
+    let a = run(&p, cid, Some(&deferred), &s, &d.join("deferred.mp4"));
+    let c = run(&p, cid, None, &s, &d.join("cpu.mp4"));
+    assert_eq!(deferred.yuv_frames.load(Ordering::SeqCst), 0, "no planes asked for");
+    assert!(a == c);
+}
+
+/// An accelerator that stops for good mid-export (`available` false): the frames left render
+/// on the CPU side by side, not one at a time under the GPU's frames-in-flight cap (as
+/// `Cx::frames` does), and the file is still the CPU's.
+#[test]
+fn frames_after_the_accelerator_stops_render_on_the_cpu() {
+    let d = out_dir("h264-gpu-yuv-stops");
+    let (p, cid) = project();
+    let s = RenderSettings { time_span: TimeSpan::LengthOfComp, ..Default::default() };
+    let stops = Fake::new(true, false, 1);
+    // Enough threads for frames to overlap wherever the machine runs it.
+    let pool = rayon::ThreadPoolBuilder::new().num_threads(4).build().unwrap();
+    let a = pool.install(|| run(&p, cid, Some(&stops), &s, &d.join("stops.mp4")));
+    let c = run(&p, cid, None, &s, &d.join("cpu.mp4"));
+    assert_eq!(stops.yuv_frames.load(Ordering::SeqCst), 1, "planes only until the stop");
+    assert!(stops.most_after_stop.load(Ordering::SeqCst) > 1, "frames after the stop rendered one at a time");
+    assert!(a == c);
+}
diff --git a/crates/export/tests/it/main.rs b/crates/export/tests/it/main.rs
index 0f89a641d..9b37d1809 100644
--- a/crates/export/tests/it/main.rs
+++ b/crates/export/tests/it/main.rs
@@ -1,9 +1,11 @@
 //! The crate's integration tests, one binary (each module is a former `tests/<name>.rs`).
 
 mod audio_sample_positions;
+mod h264_gpu_yuv;
 mod hevc_av1_roundtrip;
 #[cfg(not(target_arch = "wasm32"))]
 mod mov_audio_sample_positions;
+mod movie_bytes;
 mod ms_rounded_footage;
 #[cfg(not(target_arch = "wasm32"))]
 mod native_audio_sample_positions;
diff --git a/crates/export/tests/it/movie_bytes.rs b/crates/export/tests/it/movie_bytes.rs
new file mode 100644
index 000000000..5f1f8eb6b
--- /dev/null
+++ b/crates/export/tests/it/movie_bytes.rs
@@ -0,0 +1,104 @@
+//! Movie exports pinned byte for byte: a comp longer than one render batch, with a rotating
+//! stroked ring (mostly transparent, bilinear), a fading half-transparent solid at a fractional
+//! position and a Screen-mode shape, in 8 bpc. The comp is at most four macroblock rows high,
+//! so the H.264 encoder writes one slice per frame on any number of cores. The hashes are those of the files written before
+//! frames rendered while the previous batch encoded, before transparent source tiles were
+//! skipped and before blended pixels were quantised as they were drawn: those changes must not
+//! move a single byte.
+
+use effectcraft_color::{BlendMode, Label};
+use effectcraft_export::render_queue::{OutputFormat, OutputModule, RenderSettings, TimeSpan};
+use effectcraft_export::{Job, Sink, export};
+use effectcraft_keyframe::{Keyframe, Value};
+use effectcraft_project::build::{self, Ids};
+use effectcraft_project::{Comp, ItemId, ItemKind, LayerSource, Project, Solid};
+use effectcraft_render::NoFootage;
+use effectcraft_time::{FrameRate, Tick};
+
+fn fnv1a(data: &[u8]) -> u64 {
+    data.iter().fold(0xcbf2_9ce4_8422_2325u64, |h, &b| (h ^ b as u64).wrapping_mul(0x100_0000_01b3))
+}
+
+fn project() -> (Project, ItemId) {
+    let mut p = Project::default();
+    let mut comp = Comp::new(160, 64, FrameRate::new(30, 1), Tick::from_seconds_f64(2.0));
+    comp.background = [0.05, 0.1, 0.3];
+    let t = Tick::from_seconds_f64;
+
+    let sid = p.add_item("Half", Label::Red, None, ItemKind::Solid(Solid { color: [0.9, 0.5, 0.1], width: 70, height: 40, pixel_aspect: 1.0 }));
+    let mut solid = build::layer(&mut p, &comp, "Half", LayerSource::Solid { item: sid }, (70, 40), None);
+    if let Some(pr) = solid.props.prop_mut("transform/position") {
+        pr.value = Value::Vec3([60.25, 36.5, 0.0]);
+    }
+    if let Some(pr) = solid.props.prop_mut("transform/opacity") {
+        pr.keys = vec![Keyframe::new(t(0.0), Value::Scalar(20.0)), Keyframe::new(t(2.0), Value::Scalar(70.0))];
+    }
+
+    let mut ring = build::layer(&mut p, &comp, "Ring", LayerSource::Shape, (160, 64), None);
+    let mut box_ = build::layer(&mut p, &comp, "Box", LayerSource::Shape, (160, 64), None);
+    let mut next = p.next_id;
+    {
+        let mut ids = Ids(&mut next);
+        let e = build::shape_ellipse(&mut ids, [56.0, 56.0], [0.0, 0.0]);
+        let s = build::shape_stroke(&mut ids, [0.3, 0.8, 1.0, 1.0], 3.0);
+        let g = build::shape_group(&mut ids, "Ring", vec![e, s]);
+        if let Some(c) = ring.props.sub_mut("contents") {
+            c.children.push(g.into());
+        }
+        let r = build::shape_rect(&mut ids, [30.0, 20.0], [25.0, -10.0], 4.0);
+        let f = build::shape_fill(&mut ids, [0.2, 1.0, 0.4, 0.8]);
+        let g = build::shape_group(&mut ids, "Box", vec![r, f]);
+        if let Some(c) = box_.props.sub_mut("contents") {
+            c.children.push(g.into());
+        }
+    }
+    p.next_id = next;
+    if let Some(pr) = ring.props.prop_mut("transform/rotation") {
+        pr.keys = vec![Keyframe::new(t(0.0), Value::Scalar(0.0)), Keyframe::new(t(2.0), Value::Scalar(130.0))];
+    }
+    if let Some(pr) = box_.props.prop_mut("transform/position") {
+        pr.keys = vec![Keyframe::new(t(0.0), Value::Vec3([70.0, 30.0, 0.0])), Keyframe::new(t(2.0), Value::Vec3([95.5, 38.25, 0.0]))];
+    }
+    box_.blend_mode = BlendMode::Screen;
+
+    comp.layers = vec![box_, ring, solid];
+    let cid = p.add_item("Comp 1", Label::Sandstone, None, ItemKind::Comp(comp.into()));
+    (p, cid)
+}
+
+fn export_bytes(format: OutputFormat, name: &str) -> Vec<u8> {
+    let (p, cid) = project();
+    let settings = RenderSettings { time_span: TimeSpan::LengthOfComp, ..Default::default() };
+    let om = OutputModule::for_format(format);
+    let out = std::sync::Arc::new(std::sync::Mutex::new(Vec::new()));
+    let file = out.clone();
+    let sink: &Sink = &move |_: &str, data: Vec<u8>| *file.lock().unwrap() = data;
+    let job = Job {
+        project: &p,
+        footage: &NoFootage,
+        expr: None,
+        accel: None,
+        comp: cid,
+        settings: &settings,
+        output: &om,
+        path: name,
+        sink: Some(sink),
+        options: Default::default(),
+        nested_switches: true,
+    };
+    let r = export(&job, &mut |_| true).expect("export");
+    assert_eq!(r.frames, 60);
+    std::mem::take(&mut *out.lock().unwrap())
+}
+
+#[test]
+fn h264_movie_bytes_are_pinned() {
+    let data = export_bytes(OutputFormat::H264, "/out/pinned.mp4");
+    assert_eq!((data.len(), fnv1a(&data)), (104_161, 10_466_446_817_305_548_344), "H.264 MP4");
+}
+
+#[test]
+fn prores_movie_bytes_are_pinned() {
+    let data = export_bytes(OutputFormat::ProRes, "/out/pinned.mov");
+    assert_eq!((data.len(), fnv1a(&data)), (270_094, 8_038_709_743_204_075_800), "ProRes MOV");
+}
diff --git a/crates/export/tests/it/render_settings.rs b/crates/export/tests/it/render_settings.rs
index 9e9a0a18f..465d8e5fe 100644
--- a/crates/export/tests/it/render_settings.rs
+++ b/crates/export/tests/it/render_settings.rs
@@ -45,7 +45,7 @@ fn custom(start: f64, end: f64) -> RenderSettings {
 }
 
 fn run_with(p: &Project, cid: ItemId, s: &RenderSettings, om: &OutputModule, path: &str, options: JobOptions, cancel: bool) -> (Result<Report, String>, Files) {
-    run_on(p, cid, s, om, path, options, None, cancel)
+    run_on(p, cid, s, om, path, options, (None, cancel))
 }
 
 /// [`run_with`] with an accelerator.
@@ -56,9 +56,9 @@ fn run_on(
     om: &OutputModule,
     path: &str,
     options: JobOptions,
-    accel: Option<&dyn Accelerator>,
-    cancel: bool,
+    execution: (Option<&dyn Accelerator>, bool),
 ) -> (Result<Report, String>, Files) {
+    let (accel, cancel) = execution;
     let files: Files = Default::default();
     let f = files.clone();
     let sink: Box<Sink> = Box::new(move |path: &str, data: Vec<u8>| f.lock().unwrap().push((path.to_string(), data)));
@@ -456,7 +456,7 @@ fn a_job_renders_on_one_compositor() {
     let om = OutputModule::for_format(OutputFormat::PngSequence);
     let s = custom(0.0, 0.4);
     let render = |p: &Project, accel: &GreenAccel, path: &str| {
-        let (r, files) = run_on(p, cid, &s, &om, path, JobOptions::default(), Some(accel), false);
+        let (r, files) = run_on(p, cid, &s, &om, path, JobOptions::default(), (Some(accel), false));
         r.expect("export");
         (0..10).map(|i| png(&files, i)).collect::<Vec<_>>()
     };
diff --git a/crates/expr/src/host.rs b/crates/expr/src/host.rs
index f98b895a5..a25fbc4f0 100644
--- a/crates/expr/src/host.rs
+++ b/crates/expr/src/host.rs
@@ -313,6 +313,32 @@ impl<'a> Resolver<'a> {
         self.try_resolve(req).unwrap_or(Resp::Null)
     }
 
+    /// Resolve an ancestor from its UID path while preserving child indexing.
+    fn ancestor(&self, comp: u64, layer: u64, path: &str, up: i64) -> Option<Resp> {
+        let l = self.layer(comp, layer)?;
+        // The node's full `@uid/@uid/…` path from the layer: its ancestors are its prefixes.
+        let uid = match self.prop(comp, layer, path) {
+            Some((_, p)) => p.uid,
+            None => l.props.node(path)?.uid(),
+        };
+        let full = l.props.path_of(uid)?;
+        let segs: Vec<&str> = full.split('/').collect();
+        let up = usize::try_from(up).ok().filter(|u| *u >= 1 && *u <= segs.len())?;
+        if up == segs.len() {
+            return Some(Resp::Str("layer".into()));
+        }
+        let keep = segs.len() - up;
+        let group_path = segs.get(..keep)?.join("/");
+        let parent = match keep {
+            1 => &l.props,
+            _ => l.props.group(&segs.get(..keep - 1)?.join("/"))?,
+        };
+        let uid = segs.get(keep - 1)?.strip_prefix('@')?.parse::<u64>().ok()?;
+        let index = parent.children.iter().position(|c| c.uid() == uid)?;
+        let n = parent.children.get(index)?;
+        Some(node_resp(group_path, n, index + 1))
+    }
+
     fn try_resolve(&self, req: &Req) -> Option<Resp> {
         let project = self.ctx.project;
         Some(match req {
@@ -373,30 +399,7 @@ impl<'a> Resolver<'a> {
                 let path = if group.is_empty() { format!("@{}", n.uid()) } else { format!("{group}/@{}", n.uid()) };
                 node_resp(path, n, index)
             }
-            Req::Ancestor { comp, layer, path, up } => {
-                let l = self.layer(*comp, *layer)?;
-                // The node's full `@uid/@uid/…` path from the layer: its ancestors are its prefixes.
-                let uid = match self.prop(*comp, *layer, path) {
-                    Some((_, p)) => p.uid,
-                    None => l.props.node(path)?.uid(),
-                };
-                let full = l.props.path_of(uid)?;
-                let segs: Vec<&str> = full.split('/').collect();
-                let up = usize::try_from(*up).ok().filter(|u| *u >= 1 && *u <= segs.len())?;
-                if up == segs.len() {
-                    return Some(Resp::Str("layer".into()));
-                }
-                let keep = segs.len() - up;
-                let group_path = segs.get(..keep)?.join("/");
-                let parent = match keep {
-                    1 => &l.props,
-                    _ => l.props.group(&segs.get(..keep - 1)?.join("/"))?,
-                };
-                let uid = segs.get(keep - 1)?.strip_prefix('@')?.parse::<u64>().ok()?;
-                let index = parent.children.iter().position(|c| c.uid() == uid)?;
-                let n = parent.children.get(index)?;
-                node_resp(group_path, n, index + 1)
-            }
+            Req::Ancestor { comp, layer, path, up } => return self.ancestor(*comp, *layer, path, *up),
             Req::PropInfo { comp, layer, path } => {
                 let (l, p) = self.prop(*comp, *layer, path)?;
                 let dims = prop_dims(l, p);
diff --git a/crates/expr/src/lib.rs b/crates/expr/src/lib.rs
index 4963810c4..c77af5b37 100644
--- a/crates/expr/src/lib.rs
+++ b/crates/expr/src/lib.rs
@@ -93,7 +93,7 @@ impl ExprHost for Expressions {
             return Ok([v.first().copied().unwrap_or(100.0), v.get(1).copied().unwrap_or(100.0), v.get(2).copied().unwrap_or(100.0)]);
         };
         let value = prop.value_at(layer.layer_time(ctx.time));
-        let out = evaluate_out(self, ctx, layer, prop, &value, &e.text, [index as f64 + 1.0, total as f64], selector)?;
+        let out = evaluate_out(self, ctx, layer, prop, &value, &e.text, TextSelector { index_total: [index as f64 + 1.0, total as f64], value: selector })?;
         let num = |o: &runtime::Out| match o {
             runtime::Out::Num(x) => Some(*x),
             runtime::Out::Bool(b) => Some(if *b { 100.0 } else { 0.0 }),
@@ -124,13 +124,17 @@ impl Drop for FrameGuard {
 /// Evaluate `text` as the expression of `prop` on `layer` at `ctx.time`, given its keyframed
 /// `value`. Other properties' expressions are evaluated through `host`.
 pub fn evaluate(host: &dyn ExprHost, ctx: &EvalCtx, layer: &Layer, prop: &Property, value: &Value, text: &str) -> Result<Value, String> {
-    let out = evaluate_out(host, ctx, layer, prop, value, text, [1.0, 1.0], [100.0; 3])?;
+    let out = evaluate_out(host, ctx, layer, prop, value, text, TextSelector { index_total: [1.0, 1.0], value: [100.0; 3] })?;
     runtime::to_value(&out, value)
 }
 
-/// Run an expression and return the raw script result. `text_sel` / `selector` are the text
-/// Expression Selector's `[textIndex, textTotal]` and `selectorValue`.
-#[allow(clippy::too_many_arguments)]
+/// Expression Selector state: `[textIndex, textTotal]` and `selectorValue`.
+struct TextSelector {
+    index_total: [f64; 2],
+    value: [f64; 3],
+}
+
+/// Run an expression and return the raw script result.
 fn evaluate_out(
     host: &dyn ExprHost,
     ctx: &EvalCtx,
@@ -138,9 +142,9 @@ fn evaluate_out(
     prop: &Property,
     value: &Value,
     text: &str,
-    text_sel: [f64; 2],
-    selector: [f64; 3],
+    text_selector: TextSelector,
 ) -> Result<runtime::Out, String> {
+    let TextSelector { index_total: text_sel, value: selector } = text_selector;
     let owner = Owner { comp: ctx.comp_id.0, layer: layer.id.0, uid: prop.uid, time: ctx.time, text: text.to_string() };
     let (depth, cycle) = FRAMES.with(|f| {
         let f = f.borrow();
diff --git a/crates/gpu/src/bokeh.rs b/crates/gpu/src/bokeh.rs
index ac07448c9..39dc0bdea 100644
--- a/crates/gpu/src/bokeh.rs
+++ b/crates/gpu/src/bokeh.rs
@@ -26,7 +26,7 @@ pub(crate) fn apply(e: &mut Enc, src: &GpuImage, d: &PlaneDof) -> Option<GpuImag
         padded
     };
     let prefix = e.image(w + 1, h);
-    e.dispatch("bokeh_prefix", &Params::default(), &boosted, None, &prefix, None, (h.div_ceil(64), 1));
+    e.dispatch("bokeh_prefix", &Params::default(), crate::context::KernelImages { src: &boosted, aux: None, out: &prefix }, None, (h.div_ceil(64), 1));
     // Radius map, then every level's spans.
     let mut data: Vec<f32> = d.radius.as_ref().clone();
     let mut levels = vec![];
diff --git a/crates/gpu/src/classic3d.rs b/crates/gpu/src/classic3d.rs
index 7ee2988f9..65dc52a6e 100644
--- a/crates/gpu/src/classic3d.rs
+++ b/crates/gpu/src/classic3d.rs
@@ -126,6 +126,10 @@ const LIGHT_BYTES: usize = 6 * 16;
 /// Composite a prepared Classic 3D run over `canvas`. `None` when it cannot run here (the
 /// caller draws it on the CPU).
 pub(crate) fn draw_run(e: &mut Enc, run: &Run3d, canvas: &GpuImage) -> Option<GpuImage> {
+    // FXC (DirectX 12) may fail to build the kernel (#613): the caller renders the run on the CPU.
+    if !e.g.has_kernel("classic3d") {
+        return None;
+    }
     let (w, h) = (canvas.width, canvas.height);
     let boxes: Vec<[i64; 4]> = run.planes.iter().filter(|p| p.draw).map(|p| p.bbox).collect();
     if boxes.is_empty() {
@@ -214,7 +218,14 @@ pub(crate) fn draw_run(e: &mut Enc, run: &Run3d, canvas: &GpuImage) -> Option<Gp
     let mut p = Params::default();
     p.u[0] = [run.planes.len() as u32, run.lights.len() as u32, run.casters.len() as u32, 0];
     let out = e.scratch(w, h);
-    e.dispatch_ext("classic3d", &p, &atlas, Some(canvas), &out, Some(&mb), (w.div_ceil(16), h.div_ceil(16)), Some([&pb, &gb, &lb, &cb]));
+    e.dispatch_ext(
+        "classic3d",
+        &p,
+        crate::context::KernelImages { src: &atlas, aux: Some(canvas), out: &out },
+        Some(&mb),
+        (w.div_ceil(16), h.div_ceil(16)),
+        Some([&pb, &gb, &lb, &cb]),
+    );
     Some(out)
 }
 
diff --git a/crates/gpu/src/context.rs b/crates/gpu/src/context.rs
index 122bd53f4..bcd929304 100644
--- a/crates/gpu/src/context.rs
+++ b/crates/gpu/src/context.rs
@@ -30,7 +30,8 @@ const ENTRIES: &[&str] = &[
 const EFFECT_ENTRIES: &[&str] = &["box_h", "box_v", "directional", "glow_bright", "glow_combine", "shadow_make", "shadow_combine", "pointwise"];
 
 /// Entry points that also bind group 1 (four read-only storage buffers; see
-/// [`Enc::dispatch_ext`]).
+/// [`Enc::dispatch_ext`]). Like the effect kernels, one that fails to build (FXC on DirectX 12
+/// can't unroll `classic3d`'s loops, #613) leaves its work to the CPU.
 const EXT_ENTRIES: &[&str] = &["classic3d"];
 
 /// Pixel format of every working texture: premultiplied RGBA, 32-bit float (32 bpc headroom;
@@ -384,6 +385,12 @@ pub struct GpuContext {
     pub(crate) particle_states: crate::particles::StatesCell,
     /// Deferred readbacks (a browser worker's WebGPU device), see [`crate::deferred`].
     pub(crate) deferred: Option<Arc<crate::deferred::Deferred>>,
+    /// The adapter is a software rasteriser (llvmpipe, WARP): its float maths follows the
+    /// CPU's exactly, so the YUV tests hold it to exact parity.
+    #[cfg_attr(not(test), allow(dead_code))]
+    pub(crate) software: bool,
+    /// Export frame → YUV 4:2:0 kernel (built on first use).
+    pub(crate) yuv: std::sync::OnceLock<Result<crate::yuv::YuvPipe, String>>,
     readbacks: Arc<crate::readback::Readbacks>,
 }
 
@@ -437,7 +444,7 @@ pub(crate) fn init_resource<T>(device: &wgpu::Device, label: &str, create: impl
 /// Browser scope completion is asynchronous. Preserve the existing browser constructor;
 /// never block its event loop or introduce a guard across an asynchronous boundary here.
 #[cfg(target_arch = "wasm32")]
-fn init_resource<T>(_device: &wgpu::Device, _label: &str, create: impl FnOnce() -> T) -> Result<T, String> {
+pub(crate) fn init_resource<T>(_device: &wgpu::Device, _label: &str, create: impl FnOnce() -> T) -> Result<T, String> {
     Ok(create())
 }
 
@@ -616,15 +623,21 @@ impl GpuContext {
             })
         };
         // The compositor's own kernels are required; an effect kernel that doesn't build is
-        // left out, and its effects render on the CPU (see `Enc::take_missing`).
-        let mut pipelines = ENTRIES
-            .iter()
-            .chain(crate::adv3d::SKY_KERNELS)
-            .map(|e| (e, &layout))
-            .chain(EXT_ENTRIES.iter().map(|e| (e, &layout_ext)))
-            .map(|(e, layout)| Ok((*e, build(e, layout)?)))
-            .collect::<Result<HashMap<_, _>, String>>()?;
+        // left out, and its effects render on the CPU (see `Enc::take_missing`). So is a
+        // missing Classic 3D kernel: its 3D runs render on the CPU.
+        let mut pipelines = ENTRIES.iter().chain(crate::adv3d::SKY_KERNELS).map(|e| Ok((*e, build(e, &layout)?))).collect::<Result<HashMap<_, _>, String>>()?;
         let mut unavailable = vec![];
+        for e in EXT_ENTRIES {
+            match build(e, &layout_ext) {
+                Ok(p) => {
+                    pipelines.insert(*e, p);
+                }
+                Err(why) => {
+                    log::warn!("gpu {name}: kernel {e} unavailable, its 3D layers render on the CPU: {why}");
+                    unavailable.push((*e, why));
+                }
+            }
+        }
         for e in EFFECT_ENTRIES
             .iter()
             .chain(crate::fx_color::KERNELS)
@@ -731,6 +744,8 @@ impl GpuContext {
             transfers: Default::default(),
             zeros: Default::default(),
             adv3d: std::sync::OnceLock::new(),
+            yuv: std::sync::OnceLock::new(),
+            software: info.device_type == wgpu::DeviceType::Cpu,
             adv3d_raster: adv3d_unsupported.is_none(),
             particles: Default::default(),
             particle_states: Default::default(),
@@ -746,6 +761,18 @@ impl GpuContext {
         self.readbacks.check()
     }
 
+    /// Export frame → YUV 4:2:0 kernel, initialized once and `None` when shader or pipeline creation fails.
+    pub(crate) fn yuv_pipe(&self) -> Option<&crate::yuv::YuvPipe> {
+        self.yuv
+            .get_or_init(|| {
+                crate::yuv::YuvPipe::new(&self.device).inspect_err(|e| {
+                    log::warn!(target: "effectcraft_gpu", "yuv420 kernel unavailable: {e}");
+                })
+            })
+            .as_ref()
+            .ok()
+    }
+
     /// A notification hook for the owner of a shared device's error/loss handlers.
     /// Invoke it with diagnostic context when the host observes a device failure.
     /// It retires this context and settles pending readbacks without replacing any
@@ -907,6 +934,11 @@ impl GpuContext {
         &self.unavailable
     }
 
+    /// Whether kernel `entry` was built (an effect or Classic 3D kernel can be missing, #613).
+    pub(crate) fn has_kernel(&self, entry: &str) -> bool {
+        self.pipelines.contains_key(entry)
+    }
+
     /// Leave kernel `entry` out, as if it had failed to build (tests of the CPU fallback).
     #[cfg(test)]
     pub(crate) fn drop_kernel(&mut self, entry: &'static str) {
@@ -914,6 +946,49 @@ impl GpuContext {
         self.unavailable.push((entry, "dropped by a test".into()));
     }
 
+    /// A copy of this context sharing the same [`wgpu::Device`] and [`wgpu::Queue`] with
+    /// kernel `entry` left out, as if it had failed to build (tests of the CPU fallback
+    /// without opening a second device on `llvmpipe`).
+    #[cfg(test)]
+    pub(crate) fn without_kernel(&self, entry: &'static str) -> GpuContext {
+        let mut pipelines = self.pipelines.clone();
+        pipelines.remove(entry);
+        let mut unavailable = self.unavailable.clone();
+        unavailable.push((entry, "dropped by a test".into()));
+        GpuContext {
+            device: self.device.clone(),
+            queue: self.queue.clone(),
+            name: self.name.clone(),
+            max_dim: self.max_dim,
+            median_kernel: self.median_kernel,
+            bgl: self.bgl.clone(),
+            bgl_ext: self.bgl_ext.clone(),
+            pipelines,
+            unavailable,
+            display_bgl: self.display_bgl.clone(),
+            display: self.display.clone(),
+            display_mip: self.display_mip.clone(),
+            dummy_tex: self.dummy_tex.clone(),
+            dummy: self.dummy.clone(),
+            dummy_buf: self.dummy_buf.clone(),
+            uploads: Mutex::new(Uploads::default()),
+            upload_budget: std::sync::atomic::AtomicUsize::new(UPLOAD_BUDGET),
+            upload_full_warned: Default::default(),
+            pool: self.pool.clone(),
+            staging: Default::default(),
+            transfers: Default::default(),
+            zeros: Default::default(),
+            adv3d: std::sync::OnceLock::new(),
+            adv3d_raster: self.adv3d_raster,
+            particles: Default::default(),
+            particle_states: Default::default(),
+            deferred: self.deferred.clone(),
+            readbacks: self.readbacks.clone(),
+            software: self.software,
+            yuv: std::sync::OnceLock::new(),
+        }
+    }
+
     /// Bytes of readback staging buffers kept for reuse (tests).
     #[cfg(test)]
     pub(crate) fn staging_bytes(&self) -> u64 {
@@ -1089,6 +1164,13 @@ pub(crate) struct Enc<'g> {
     owner: u64,
 }
 
+/// Images bound to a compute kernel's source, optional auxiliary and output slots.
+pub(crate) struct KernelImages<'a> {
+    pub src: &'a GpuImage,
+    pub aux: Option<&'a GpuImage>,
+    pub out: &'a GpuImage,
+}
+
 impl Drop for Enc<'_> {
     fn drop(&mut self) {
         // Unsubmitted work is discarded, so nothing recorded will read pooled textures.
@@ -1162,32 +1244,21 @@ impl<'g> Enc<'g> {
     }
 
     /// Run kernel `entry` writing `out` (dispatched over `groups` workgroups).
-    pub fn dispatch(
-        &mut self,
-        entry: &str,
-        p: &Params,
-        src: &GpuImage,
-        aux: Option<&GpuImage>,
-        out: &GpuImage,
-        data: Option<&wgpu::Buffer>,
-        groups: (u32, u32),
-    ) {
-        self.dispatch_ext(entry, p, src, aux, out, data, groups, None);
+    pub fn dispatch(&mut self, entry: &str, p: &Params, images: KernelImages<'_>, data: Option<&wgpu::Buffer>, groups: (u32, u32)) {
+        self.dispatch_ext(entry, p, images, data, groups, None);
     }
 
     /// [`Enc::dispatch`] for the kernels in `EXT_ENTRIES`, with their group 1 storage buffers.
-    #[allow(clippy::too_many_arguments)]
     pub fn dispatch_ext(
         &mut self,
         entry: &str,
         p: &Params,
-        src: &GpuImage,
-        aux: Option<&GpuImage>,
-        out: &GpuImage,
+        images: KernelImages<'_>,
         data: Option<&wgpu::Buffer>,
         groups: (u32, u32),
         ext: Option<[&wgpu::Buffer; 4]>,
     ) {
+        let KernelImages { src, aux, out } = images;
         let g = self.g;
         let Some(pipe) = g.pipelines.get(entry) else {
             if !g.unavailable.iter().any(|(e, _)| *e == entry) {
@@ -1243,7 +1314,7 @@ impl<'g> Enc<'g> {
     /// Per-pixel kernel over `out`'s size (16×16 workgroups).
     pub fn pixels(&mut self, entry: &str, p: &Params, src: &GpuImage, aux: Option<&GpuImage>, out: &GpuImage, data: Option<&wgpu::Buffer>) {
         let groups = (out.width.div_ceil(16), out.height.div_ceil(16));
-        self.dispatch(entry, p, src, aux, out, data, groups);
+        self.dispatch(entry, p, KernelImages { src, aux, out }, data, groups);
     }
 
     /// Copy `src` into a larger zeroed image at (`x`, `y`) (Buf::pad).
diff --git a/crates/gpu/src/effects.rs b/crates/gpu/src/effects.rs
index 5041582f9..1e97b7eab 100644
--- a/crates/gpu/src/effects.rs
+++ b/crates/gpu/src/effects.rs
@@ -2,7 +2,6 @@
 //! radii, parameter conversions), with the pixel loops as compute kernels.
 
 use effectcraft_effects::{Buf, EffectCtx};
-use effectcraft_geom::{Mat3, vec2};
 use effectcraft_raster::Sampling;
 use effectcraft_render::FxStep;
 
@@ -27,6 +26,24 @@ impl GBuf {
         (p[0] * self.scale + self.offset[0], p[1] * self.scale + self.offset[1])
     }
 
+    /// Buf::pad_sides: grow by transparent pixels (left, top, right, bottom).
+    pub fn pad_sides(&mut self, e: &mut Enc, sides: [u32; 4]) -> Option<()> {
+        let [l, t, r, b] = sides;
+        if l == 0 && t == 0 && r == 0 && b == 0 {
+            return Some(());
+        }
+        let (w, h) = (self.img.width.checked_add(l)?.checked_add(r)?, self.img.height.checked_add(t)?.checked_add(b)?);
+        if !e.g.fits(w, h) {
+            return None;
+        }
+        let out = e.image(w, h);
+        e.copy_into(&self.img, &out, l, t);
+        self.img = out;
+        self.offset[0] += l as f64;
+        self.offset[1] += t as f64;
+        Some(())
+    }
+
     /// Buf::pad: grow by `pad` transparent pixels on every side.
     pub fn pad(&mut self, e: &mut Enc, pad: u32) -> Option<()> {
         if pad == 0 {
@@ -234,7 +251,13 @@ pub(crate) fn box_passes(e: &mut Enc, img: &GpuImage, rx: &[usize], ry: &[usize]
         let mut p = Params::default();
         p.u[0] = [r as u32, repeat as u32, block, 0];
         let out = e.scratch(cur.width, cur.height);
-        e.dispatch(if vertical { "box_v" } else { "box_h" }, &p, &cur, None, &out, None, (lines.div_ceil(64), n.div_ceil(block)));
+        e.dispatch(
+            if vertical { "box_v" } else { "box_h" },
+            &p,
+            crate::context::KernelImages { src: &cur, aux: None, out: &out },
+            None,
+            (lines.div_ceil(64), n.div_ceil(block)),
+        );
         cur = out;
     }
     cur
@@ -333,10 +356,11 @@ fn glow(e: &mut Enc, ctx: &EffectCtx, mut b: GBuf) -> Option<GBuf> {
     p.f[2] = cb;
     let bright = e.image(b.img.width, b.img.height);
     e.pixels("glow_bright", &p, &b.img, None, &bright, None);
-    let s = (radius / 2.0).max(0.5);
+    let s = effectcraft_effects::glow_sigma(radius);
     let blurred = gaussian_blur(e, &bright, s * kx, s * ky, false);
     let mut p = Params::default();
     p.u[0][0] = ctx.params.e("operation").min(2);
+    p.u[0][1] = (ctx.params.e("based") == 0) as u32;
     p.f[0][0] = intensity;
     let out = e.scratch(b.img.width, b.img.height);
     e.pixels("glow_combine", &p, &b.img, Some(&blurred), &out, None);
@@ -378,19 +402,17 @@ fn transform(e: &mut Enc, ctx: &EffectCtx, mut b: GBuf) -> Option<GBuf> {
     if ctx.env.host.is_some() && effectcraft_effects::transform_shutter(ctx).is_some() {
         return None;
     }
-    let anchor = b.to_px(ctx.params.v2("anchor"));
-    let pos = b.to_px(ctx.params.v2("position"));
-    let sh = ctx.params.f("scaleHeight");
-    let sw = if ctx.params.b("uniform") { sh } else { ctx.params.f("scaleWidth") };
     let opacity = ctx.params.f("opacity") as f32 / 100.0;
-    let m = Mat3::translate(vec2(pos.0, pos.1))
-        * Mat3::rotate_deg(ctx.params.f("rotation"))
-        * Mat3::skew_deg(ctx.params.f("skew"), ctx.params.f("skewAxis"))
-        * Mat3::scale(vec2(sw / 100.0, sh / 100.0))
-        * Mat3::translate(vec2(-anchor.0, -anchor.1));
+    // As distort::transform: After Effects' matrix, drawn outside the layer's bounds.
+    if !ctx.adjustment {
+        let m = effectcraft_effects::transform_matrix_px(ctx.params, |p| b.to_px(p));
+        let sides = effectcraft_effects::transform_grow(&[m], b.img.width, b.img.height);
+        b.pad_sides(e, sides)?;
+    }
+    let m = effectcraft_effects::transform_matrix_px(ctx.params, |p| b.to_px(p));
     let sampling = if ctx.params.e("sampling") == 1 { Sampling::Bicubic } else { Sampling::Bilinear };
     let empty = e.image(b.img.width, b.img.height);
-    b.img = ops::warp(e, &empty, &b.img, &m, sampling, effectcraft_color::BlendMode::Normal, opacity, 0, None);
+    b.img = ops::warp(e, &empty, &b.img, &m, ops::WarpOptions { sampling, mode: effectcraft_color::BlendMode::Normal, opacity, seed: 0 }, None);
     Some(b)
 }
 
@@ -537,9 +559,19 @@ fn pointwise(e: &mut Enc, id: &str, ctx: &EffectCtx, b: GBuf) -> Option<GBuf> {
             let sub = (f("subSettings/subScaling") / 100.0).clamp(0.1, 1.0);
             p.u[0] = [10, kind, octaves.ceil() as u32, f("evolutionOptions/seed") as u32 ^ 0x51ed];
             p.u[1] = [pr.b("invert") as u32, pr.e("overflow"), mode, 0];
-            p.f[0] = [f("contrast") as f32 / 100.0, f("brightness") as f32 / 100.0, (sw * b.scale).max(1.0) as f32, (octaves - octaves.floor()) as f32];
+            p.f[0] = [
+                f("contrast") as f32 / 100.0,
+                f("brightness") as f32 / 100.0,
+                (sw * effectcraft_effects::NOISE_CELL * b.scale).max(1.0) as f32,
+                (octaves - octaves.floor()) as f32,
+            ];
             p.f[1] = [ox as f32, oy as f32, sr, cr];
-            p.f[2] = [f("evolution") as f32 / 360.0, f("blend") as f32 / 100.0, (f("opacity") as f32 / 100.0).clamp(0.0, 1.0), (sh * b.scale).max(1.0) as f32];
+            p.f[2] = [
+                f("evolution") as f32 / 360.0,
+                f("blend") as f32 / 100.0,
+                (f("opacity") as f32 / 100.0).clamp(0.0, 1.0),
+                (sh * effectcraft_effects::NOISE_CELL * b.scale).max(1.0) as f32,
+            ];
             p.f[3] = [(f("subSettings/subInfluence") as f32 / 100.0).clamp(0.0, 1.0), 1.0 / sub as f32, 0.0, 0.0];
         }
         _ => return None,
diff --git a/crates/gpu/src/fx_depth.rs b/crates/gpu/src/fx_depth.rs
index 1bb0e49e1..eb2a96adb 100644
--- a/crates/gpu/src/fx_depth.rs
+++ b/crates/gpu/src/fx_depth.rs
@@ -280,7 +280,7 @@ fn cryptomatte(e: &mut Enc, ctx: &EffectCtx, b: GBuf, a: &AuxChannels) -> Option
     // cores with the rank planes resolved once.
     // The ID colours are only read by the Colors display; Matte, Preview and Matte Only need the
     // matte alone.
-    // `tests_fx_depth::cryptomatte_every_display_matches_the_cpu` guards this against the shader.
+    // `tests::fx_depth::cryptomatte_every_display_matches_the_cpu` guards this against the shader.
     let what = effectcraft_effects::CryptoAux::for_display(pr.e("display"), pr.b("matteOnly"));
     let img = effectcraft_effects::crypto_aux_image_with(a, &layer, &sel, what);
     let tex = e.g.upload_image(&img)?;
diff --git a/crates/gpu/src/fx_generate.rs b/crates/gpu/src/fx_generate.rs
index 0089dd4f4..d0c96a029 100644
--- a/crates/gpu/src/fx_generate.rs
+++ b/crates/gpu/src/fx_generate.rs
@@ -165,7 +165,7 @@ fn camera_lens(e: &mut Enc, ctx: &EffectCtx, mut b: GBuf) -> Option<GBuf> {
             return None;
         }
         let pre = e.image(w + 1, h);
-        e.dispatch("gen_row_prefix", &Params::default(), &src, None, &pre, None, (h.div_ceil(64), 1));
+        e.dispatch("gen_row_prefix", &Params::default(), crate::context::KernelImages { src: &src, aux: None, out: &pre }, None, (h.div_ceil(64), 1));
         Some(pre)
     } else {
         None
@@ -207,55 +207,53 @@ fn linear_wipe(e: &mut Enc, ctx: &EffectCtx, b: GBuf) -> Option<GBuf> {
 }
 
 fn venetian(e: &mut Enc, ctx: &EffectCtx, b: GBuf) -> Option<GBuf> {
-    let done = ctx.params.f("completion") / 100.0;
+    let done = (ctx.params.f("completion") / 100.0).clamp(0.0, 1.0);
+    if done <= 0.0 {
+        return Some(b);
+    }
     let ang = ctx.params.f("direction").to_radians();
     let width = (ctx.params.f("width") * b.scale).max(1.0);
-    let feather = (ctx.params.f("feather") * b.scale).max(0.001);
+    let sigma = ctx.params.f("feather").max(0.0) * b.scale / 2.0;
+    // The CPU's even veil and term count (effects::venetian_cover).
+    if sigma > 8.0 * width {
+        return None;
+    }
     let (dx, dy) = (ang.cos(), ang.sin());
-    let mut data = Vec::with_capacity((6 * b.img.width + 2 * b.img.height) as usize);
+    let (ox, oy) = b.to_px(effectcraft_effects::venetian_origin(ctx.layer_size));
+    let mut data = Vec::with_capacity((4 * b.img.width + 2 * b.img.height) as usize);
     for x in 0..b.img.width {
-        let cx = ((x as f64 + 0.5) * dx).rem_euclid(width);
-        data.extend(hl(cx - done * width));
-        data.extend(hl(cx - width - done * width));
+        let cx = ((x as f64 + 0.5 - ox) * dx).rem_euclid(width);
+        data.extend(hl(cx));
         data.extend(hl(cx - width));
     }
     for y in 0..b.img.height {
-        data.extend(hl(((y as f64 + 0.5) * dy).rem_euclid(width)));
+        data.extend(hl(((y as f64 + 0.5 - oy) * dy).rem_euclid(width)));
     }
     let mut p = Params::default();
-    p.u[0][0] = 6 * b.img.width;
-    p.f[0][0] = feather as f32;
+    p.u[0][0] = 4 * b.img.width;
+    p.u[0][1] = if sigma < 1e-3 { 0 } else { ((4.0 * sigma / width).ceil() as u32 + 1).clamp(1, 40) };
+    p.f[0] = [width as f32, (done * width) as f32, sigma as f32, 0.0];
     run(e, "gen_venetian", &p, b, None, Some(&data))
 }
 
 fn radial_wipe(e: &mut Enc, ctx: &EffectCtx, b: GBuf) -> Option<GBuf> {
-    let done = ctx.params.f("completion") / 100.0;
+    let done = (ctx.params.f("completion") / 100.0).clamp(0.0, 1.0);
+    if done <= 0.0 {
+        return Some(b);
+    }
     let start = ctx.params.f("startAngle");
     let c = b.to_px(ctx.params.v2("center"));
-    let dir = ctx.params.e("wipe");
-    let feather = ctx.params.f("feather").max(0.01);
-    let edge = if dir == 2 { done * 180.0 } else { done * 360.0 };
-    // Rotations: the start angle, and the start angle ± the edge (where the wipe's edge lies).
-    let rots = [start, start + edge, start - edge].map(|r| r.to_radians().sin_cos());
-    let mut data = Vec::with_capacity(9 * (b.img.width + b.img.height) as usize);
-    for x in 0..b.img.width {
-        let ux = x as f64 + 0.5 - c.0;
-        for (s, co) in rots {
-            data.extend(hl(ux * co));
-            data.push((ux * s) as f32);
-        }
-    }
-    for y in 0..b.img.height {
-        let uy = -(y as f64 + 0.5 - c.1);
-        for (s, co) in rots {
-            data.extend(hl(uy * s));
-            data.push((uy * co) as f32);
-        }
-    }
+    let (w0, span) = effectcraft_effects::radial_wipe_wedge(ctx.params.e("wipe"), done);
+    let sigma = effectcraft_effects::radial_wipe_sigma(ctx.params.f("feather")) * b.scale;
+    let ray0 = start + w0;
+    let (s0, c0) = ray0.to_radians().sin_cos();
+    let (s1, c1) = (ray0 + span).to_radians().sin_cos();
     let mut p = Params::default();
-    p.u[0] = [9 * b.img.width, dir.min(2), 0, 0];
-    p.f[0] = [edge as f32, feather as f32, 0.0, 0.0];
-    run(e, "gen_radial_wipe", &p, b, None, Some(&data))
+    p.u[0] = [(done >= 1.0) as u32, (sigma < 1e-3) as u32, 0, 0];
+    p.f[0] = [c.0 as f32, c.1 as f32, sigma.max(1e-3) as f32, ray0.rem_euclid(360.0) as f32];
+    p.f[1] = [s0 as f32, c0 as f32, s1 as f32, c1 as f32];
+    p.f[2][0] = span as f32;
+    run(e, "gen_radial_wipe", &p, b, None, None)
 }
 
 fn gradient_wipe(e: &mut Enc, ctx: &EffectCtx, b: GBuf) -> Option<GBuf> {
diff --git a/crates/gpu/src/fx_noise.rs b/crates/gpu/src/fx_noise.rs
index b954f8cf3..22f23fd86 100644
--- a/crates/gpu/src/fx_noise.rs
+++ b/crates/gpu/src/fx_noise.rs
@@ -214,7 +214,7 @@ pub(crate) fn median_image(e: &mut Enc, img: &GpuImage, r: usize, straight: bool
     let seg = (4 * r as u32).clamp(32, 512).min(q.width);
     let out = e.scratch(q.width, q.height);
     let groups = (q.height.div_ceil(e.g.median_kernel.rows_per_workgroup()), q.width.div_ceil(seg));
-    e.dispatch("fxn_median_huang", &with_u0([r as u32, seg, 0, 0]), &q, None, &out, Some(&levels), groups);
+    e.dispatch("fxn_median_huang", &with_u0([r as u32, seg, 0, 0]), crate::context::KernelImages { src: &q, aux: None, out: &out }, Some(&levels), groups);
     out
 }
 
diff --git a/crates/gpu/src/fx_stylize.rs b/crates/gpu/src/fx_stylize.rs
index d53367e76..cc9045a41 100644
--- a/crates/gpu/src/fx_stylize.rs
+++ b/crates/gpu/src/fx_stylize.rs
@@ -879,7 +879,7 @@ fn corner_pin(e: &mut Enc, ctx: &EffectCtx, mut b: GBuf) -> Option<GBuf> {
     let o = b.to_px([0.0, 0.0]);
     let m = quad * Mat3::scale(vec2(1.0 / (w * b.scale), 1.0 / (h * b.scale))) * Mat3::translate(vec2(-o.0, -o.1));
     let empty = e.image(b.img.width, b.img.height);
-    b.img = ops::warp(e, &empty, &b.img, &m, Sampling::Bilinear, BlendMode::Normal, 1.0, 0, None);
+    b.img = ops::warp(e, &empty, &b.img, &m, ops::WarpOptions { sampling: Sampling::Bilinear, mode: BlendMode::Normal, opacity: 1.0, seed: 0 }, None);
     Some(b)
 }
 
@@ -937,11 +937,12 @@ pub(crate) fn glow(e: &mut Enc, ctx: &EffectCtx, mut b: GBuf) -> Option<GBuf> {
         p.f[2] = ctx.params.color("colorB");
         e.pixels("glow_bright", &p, &b.img, None, &bright, None);
     }
-    let s = (radius / 2.0).max(0.5);
+    let s = effectcraft_effects::glow_sigma(radius);
     let blurred = gaussian_blur(e, &bright, s * kx, s * ky, false);
     let operation = ctx.params.e("operation");
     let glow_op = effectcraft_effects::glow_operation(ctx);
     let mut p = Params::default();
+    p.u[0][1] = (ctx.params.e("based") == 0) as u32;
     p.f[0][0] = intensity;
     let out = e.scratch(b.img.width, b.img.height);
     if operation == 0 && glow_op != BlendMode::Add {
@@ -963,15 +964,7 @@ pub(crate) fn transform_blur(ctx: &EffectCtx) -> bool {
 
 /// distort::transform_matrix.
 fn transform_matrix(pr: &effectcraft_effects::Params, b: &GBuf) -> Mat3 {
-    let anchor = b.to_px(pr.v2("anchor"));
-    let pos = b.to_px(pr.v2("position"));
-    let sh = pr.f("scaleHeight");
-    let sw = if pr.b("uniform") { sh } else { pr.f("scaleWidth") };
-    Mat3::translate(vec2(pos.0, pos.1))
-        * Mat3::rotate_deg(pr.f("rotation"))
-        * Mat3::skew_deg(pr.f("skew"), pr.f("skewAxis"))
-        * Mat3::scale(vec2(sw / 100.0, sh / 100.0))
-        * Mat3::translate(vec2(-anchor.0, -anchor.1))
+    effectcraft_effects::transform_matrix_px(pr, |p| b.to_px(p))
 }
 
 /// distort::transform's motion blur: the transform at Samples instants across the shutter,
@@ -981,15 +974,24 @@ pub(crate) fn transform(e: &mut Enc, ctx: &EffectCtx, mut b: GBuf) -> Option<GBu
     let host = ctx.env.host?;
     let sampling = if ctx.params.e("sampling") == 1 { Sampling::Bicubic } else { Sampling::Bilinear };
     let fd = 1.0 / ctx.fps();
+    let samples: Vec<effectcraft_effects::Params> =
+        (0..n).filter_map(|k| host.params_at(ctx.time + (phase + angle * k as f64 / (n - 1) as f64) / 360.0 * fd)).collect();
+    if samples.is_empty() {
+        // The CPU renders the frame sharp.
+        return None;
+    }
+    if !ctx.adjustment {
+        let ms: Vec<Mat3> = samples.iter().map(|pr| transform_matrix(pr, &b)).collect();
+        let sides = effectcraft_effects::transform_grow(&ms, b.img.width, b.img.height);
+        b.pad_sides(e, sides)?;
+    }
     let (w, h) = (b.img.width, b.img.height);
     let mut acc = e.image(w, h);
     let mut count = 0u32;
-    for k in 0..n {
-        let t = ctx.time + (phase + angle * k as f64 / (n - 1) as f64) / 360.0 * fd;
-        let Some(pr) = host.params_at(t) else { continue };
+    for pr in &samples {
         let op = pr.f("opacity") as f32 / 100.0;
         let empty = e.image(w, h);
-        let one = ops::warp(e, &empty, &b.img, &transform_matrix(&pr, &b), sampling, BlendMode::Normal, op, 0, None);
+        let one = ops::warp(e, &empty, &b.img, &transform_matrix(pr, &b), ops::WarpOptions { sampling, mode: BlendMode::Normal, opacity: op, seed: 0 }, None);
         let sum = e.image(w, h);
         e.pixels("fxs_add", &Params::default(), &acc, Some(&one), &sum, None);
         acc = sum;
diff --git a/crates/gpu/src/fx_vr.rs b/crates/gpu/src/fx_vr.rs
index e719d606f..438eeb661 100644
--- a/crates/gpu/src/fx_vr.rs
+++ b/crates/gpu/src/fx_vr.rs
@@ -181,7 +181,13 @@ fn sphere_blur(e: &mut Enc, img: &GpuImage, sigma: f64) -> GpuImage {
         let mut p = Params::default();
         p.u[0][0] = 256;
         let out = e.scratch(cur.width, cur.height);
-        e.dispatch("fxv_box_h", &p, &cur, None, &out, Some(&buf), (cur.height.div_ceil(64), cur.width.div_ceil(256)));
+        e.dispatch(
+            "fxv_box_h",
+            &p,
+            crate::context::KernelImages { src: &cur, aux: None, out: &out },
+            Some(&buf),
+            (cur.height.div_ceil(64), cur.width.div_ceil(256)),
+        );
         cur = out;
     }
     for &r in &radii {
@@ -192,7 +198,13 @@ fn sphere_blur(e: &mut Enc, img: &GpuImage, sigma: f64) -> GpuImage {
         let mut p = Params::default();
         p.u[0] = [block, r as u32, 0, 0];
         let out = e.scratch(cur.width, cur.height);
-        e.dispatch("fxv_box_v", &p, &cur, None, &out, None, (cur.width.div_ceil(64), cur.height.div_ceil(block)));
+        e.dispatch(
+            "fxv_box_v",
+            &p,
+            crate::context::KernelImages { src: &cur, aux: None, out: &out },
+            None,
+            (cur.width.div_ceil(64), cur.height.div_ceil(block)),
+        );
         cur = out;
     }
     cur
diff --git a/crates/gpu/src/lib.rs b/crates/gpu/src/lib.rs
index 1064a216d..94b95166a 100644
--- a/crates/gpu/src/lib.rs
+++ b/crates/gpu/src/lib.rs
@@ -83,6 +83,7 @@ mod ops;
 mod particles;
 mod readback;
 mod walk;
+mod yuv;
 
 use std::sync::Arc;
 
@@ -339,6 +340,25 @@ impl Accelerator for Gpu {
         img
     }
 
+    fn comp_frame_yuv420(&self, r: &Renderer, comp: ItemId, t: Tick, bg: [f32; 3]) -> Option<Vec<u8>> {
+        self.ctx.check_health().ok()?;
+        if !self.ctx.can_readback() || self.ctx.deferred.is_some() {
+            return None;
+        }
+        // Sizes the kernel can't take fall back before any GPU work, not after a render.
+        let (w, h) = walk::frame_size(r, comp, t)?;
+        if !yuv::supported(w, h) || !yuv::fits_limits(w, h, &self.ctx.device.limits()) {
+            return None;
+        }
+        let yp = self.ctx.yuv_pipe()?;
+        let mut e = Enc::new(&self.ctx);
+        let img = walk::render(&mut e, r, comp, t)?;
+        let planes = yuv::convert(&mut e, yp, &img, bg)?;
+        // A device fault seen while the frame recorded makes the planes untrustworthy.
+        self.ctx.check_health().ok()?;
+        Some(planes)
+    }
+
     fn supports_effect(&self, id: &str) -> bool {
         self.ctx.check_health().is_ok() && self.ctx.can_readback() && effects::supports(id)
     }
@@ -407,59 +427,3 @@ impl effectcraft_effects::psim::ParticleSim for Gpu {
 
 #[cfg(test)]
 mod tests;
-#[cfg(test)]
-mod tests_3d;
-#[cfg(test)]
-mod tests_adjust;
-#[cfg(test)]
-mod tests_adv3d;
-#[cfg(test)]
-mod tests_deferred;
-#[cfg(test)]
-mod tests_deferred_jobs;
-#[cfg(test)]
-mod tests_fx_color;
-#[cfg(test)]
-mod tests_fx_depth;
-#[cfg(test)]
-mod tests_fx_distort;
-#[cfg(test)]
-mod tests_fx_extra;
-#[cfg(test)]
-mod tests_fx_gen2;
-#[cfg(test)]
-mod tests_fx_generate;
-#[cfg(test)]
-mod tests_fx_key;
-#[cfg(test)]
-mod tests_fx_light;
-#[cfg(test)]
-mod tests_fx_lut;
-#[cfg(test)]
-mod tests_fx_noise;
-#[cfg(test)]
-mod tests_fx_particles;
-#[cfg(test)]
-mod tests_fx_pixel2;
-#[cfg(test)]
-mod tests_fx_sim;
-#[cfg(test)]
-mod tests_fx_stylize;
-#[cfg(test)]
-mod tests_fx_text;
-#[cfg(test)]
-mod tests_fx_time;
-#[cfg(test)]
-mod tests_fx_tone;
-#[cfg(test)]
-mod tests_fx_transition;
-#[cfg(test)]
-mod tests_fx_vr;
-#[cfg(test)]
-mod tests_fx_warp;
-#[cfg(all(test, not(target_arch = "wasm32")))]
-mod tests_init;
-#[cfg(test)]
-mod tests_particles;
-#[cfg(test)]
-mod tests_wgsl_grammar;
diff --git a/crates/gpu/src/ops.rs b/crates/gpu/src/ops.rs
index c9e0900e9..30c8c9bea 100644
--- a/crates/gpu/src/ops.rs
+++ b/crates/gpu/src/ops.rs
@@ -32,37 +32,23 @@ pub fn half(e: &mut Enc, src: &GpuImage) -> GpuImage {
     out
 }
 
-/// `raster::composite_warp` (and, with `accumulate = Some(weight)`, `accumulate_warp`): draw
-/// `src` transformed by `m` (src pixels → dst pixels) onto `dst`.
-pub fn warp(
-    e: &mut Enc,
-    dst: &GpuImage,
-    src: &GpuImage,
-    m: &Mat3,
-    sampling: Sampling,
-    mode: BlendMode,
-    opacity: f32,
-    seed: u32,
-    accumulate: Option<f32>,
-) -> GpuImage {
-    warp_q(e, dst, src, m, sampling, mode, opacity, seed, accumulate, None)
+/// Sampling and blending policy for a transformed GPU image.
+pub struct WarpOptions {
+    pub sampling: Sampling,
+    pub mode: BlendMode,
+    pub opacity: f32,
+    pub seed: u32,
+}
+
+/// Draw `src` transformed by `m` onto `dst`, or accumulate it with a sample weight.
+pub fn warp(e: &mut Enc, dst: &GpuImage, src: &GpuImage, m: &Mat3, opts: WarpOptions, accumulate: Option<f32>) -> GpuImage {
+    warp_q(e, dst, src, m, opts, accumulate, None)
 }
 
 /// [`warp`], clamping and quantising the result to `levels` (8/16 bpc: the comp after a layer,
 /// in the same pass).
-#[allow(clippy::too_many_arguments)]
-pub fn warp_q(
-    e: &mut Enc,
-    dst: &GpuImage,
-    src: &GpuImage,
-    m: &Mat3,
-    sampling: Sampling,
-    mode: BlendMode,
-    opacity: f32,
-    seed: u32,
-    accumulate: Option<f32>,
-    levels: Option<f32>,
-) -> GpuImage {
+pub fn warp_q(e: &mut Enc, dst: &GpuImage, src: &GpuImage, m: &Mat3, opts: WarpOptions, accumulate: Option<f32>, levels: Option<f32>) -> GpuImage {
+    let WarpOptions { sampling, mode, opacity, seed } = opts;
     if src.width == 0 || src.height == 0 || opacity <= 0.0 {
         return dst.clone();
     }
diff --git a/crates/gpu/src/shaders/classic3d.wgsl b/crates/gpu/src/shaders/classic3d.wgsl
index d2cad8324..1c963385a 100644
--- a/crates/gpu/src/shaders/classic3d.wgsl
+++ b/crates/gpu/src/shaders/classic3d.wgsl
@@ -255,16 +255,14 @@ fn occlusion(c: u32, p: vec3<f32>, l: u32) -> vec3<f32> {
     }
     let tr = pl.mat1.y;
     let dark = li.shadow.x;
-    var o = vec3<f32>(1.0);
-    for (var k = 0; k < 3; k++) {
-        var st = 0.0;
-        if (px.w > 0.0) {
-            st = clamp(px[k] / px.w, 0.0, 1.0);
-        }
-        let through = (1.0 - alpha) + alpha * tr * st;
-        o[k] = 1.0 - dark * (1.0 - through);
+    // Per channel, as whole vectors: FXC (DirectX 12) can't write a vector component through a
+    // loop index without unrolling every loop around the call, and fails (#613).
+    var st = vec3<f32>(0.0);
+    if (px.w > 0.0) {
+        st = clamp(px.xyz / px.w, vec3<f32>(0.0), vec3<f32>(1.0));
     }
-    return o;
+    let through = (1.0 - alpha) + alpha * tr * st;
+    return 1.0 - dark * (1.0 - through);
 }
 
 fn shadow_of(it: u32, l: u32, p: vec3<f32>) -> vec3<f32> {
diff --git a/crates/gpu/src/shaders/fx_generate.wgsl b/crates/gpu/src/shaders/fx_generate.wgsl
index bca00ce1b..57d1c89e3 100644
--- a/crates/gpu/src/shaders/fx_generate.wgsl
+++ b/crates/gpu/src/shaders/fx_generate.wgsl
@@ -42,6 +42,15 @@ fn gen_sum(a: vec2<f32>, b: vec2<f32>) -> f32 {
     return (a.x + b.x) + (a.y + b.y);
 }
 
+// Standard normal CDF (Abramowitz & Stegun 7.1.26 erf; effects::misc::norm_cdf).
+fn gen_norm_cdf(z: f32) -> f32 {
+    let x = abs(z) * 0.70710678;
+    let t = 1.0 / (1.0 + 0.3275911 * x);
+    let poly = t * (0.254829592 + t * (-0.284496736 + t * (1.421413741 + t * (-1.453152027 + t * 1.061405429))));
+    let erf = 1.0 - poly * exp(-x * x);
+    return select(0.5 * (1.0 - erf), 0.5 * (1.0 + erf), z >= 0.0);
+}
+
 // ---------------------------------------------------------------- Radial Blur (raster::radial_blur)
 
 // u[0] = (zoom, samples); f[0] = (cx, cy); data = per sample (sin, cos) (spin) or k (zoom).
@@ -67,7 +76,10 @@ fn gen_radial_blur(@builtin(global_invocation_id) gid: vec3<u32>) {
             let cs = data[2u * i + 1u];
             s = vec2<f32>(c.x + v.x * cs - v.y * sn, c.y + v.x * sn + v.y * cs);
         }
-        acc += sample_bilinear(src, s.x, s.y);
+        // Edge samples repeat (raster::radial_blur).
+        let hi = vec2<f32>(f32(dims.x), f32(dims.y)) - vec2<f32>(0.5);
+        let sc = clamp(s, vec2<f32>(0.5), max(hi, vec2<f32>(0.5)));
+        acc += sample_bilinear(src, sc.x, sc.y);
     }
     textureStore(out, p, acc / f32(n));
 }
@@ -235,9 +247,9 @@ fn gen_linear_wipe(@builtin(global_invocation_id) gid: vec3<u32>) {
     textureStore(out, p, textureLoad(src, p, 0) * k);
 }
 
-// Venetian Blinds. Per column (6 floats): (cx − done·w), (cx − w − done·w), (cx − w) as
-// (hi, lo), with cx = ((x + 0.5)·dx) mod w; per row (2 floats): ((y + 0.5)·dy) mod w.
-// u[0].x = row table offset; f[0].x = feather.
+// Venetian Blinds (effects::venetian_cover). Per column (4 floats): cx, (cx − w) as (hi, lo),
+// with cx = ((x + 0.5 − ox)·dx) mod w; per row (2 floats): ((y + 0.5 − oy)·dy) mod w.
+// u[0] = (row table offset, Gaussian terms per side, 0 = hard edge); f[0] = (w, band, σ).
 @compute @workgroup_size(16, 16)
 fn gen_venetian(@builtin(global_invocation_id) gid: vec3<u32>) {
     let dims = out_dims();
@@ -245,34 +257,33 @@ fn gen_venetian(@builtin(global_invocation_id) gid: vec3<u32>) {
     if (p.x >= dims.x || p.y >= dims.y) {
         return;
     }
-    let col = 6u * u32(p.x);
+    let col = 4u * u32(p.x);
     let row = gen_hl(P.u[0].x + 2u * u32(p.y));
     // (d mod w) wraps once the column and row terms reach w.
-    let wrapped = gen_sum(gen_hl(col + 4u), row) >= 0.0;
-    var t: f32;
-    if (wrapped) {
-        t = gen_sum(gen_hl(col + 2u), row);
-    } else {
-        t = gen_sum(gen_hl(col), row);
+    var d = gen_sum(gen_hl(col), row);
+    if (gen_sum(gen_hl(col + 2u), row) >= 0.0) {
+        d = gen_sum(gen_hl(col + 2u), row);
     }
-    let k = clamp(t / P.f[0].x + 0.5, 0.0, 1.0);
-    textureStore(out, p, textureLoad(src, p, 0) * k);
+    let w = P.f[0].x;
+    let band = P.f[0].y;
+    let sigma = P.f[0].z;
+    let n = i32(P.u[0].y);
+    var t = 0.0;
+    if (n == 0) {
+        t = select(0.0, 1.0, d < band);
+    } else {
+        for (var k = -n; k <= n; k++) {
+            let u = d + f32(k) * w;
+            t += gen_norm_cdf(u / sigma) - gen_norm_cdf((u - band) / sigma);
+        }
+    }
+    let cover = clamp(t, 0.0, 1.0);
+    textureStore(out, p, textureLoad(src, p, 0) * (1.0 - cover));
 }
 
-// Angle (degrees, clockwise from up) of the pixel vector rotated by rotation `r` (0 = start,
-// 1 = start + edge, 2 = start − edge), from the per-column / per-row tables of Radial Wipe.
-fn gen_psi(r: u32, x: u32, y: u32) -> f32 {
-    let c = 9u * x + 3u * r;
-    let w = P.u[0].x + 9u * y + 3u * r;
-    // x' = ux·cos R − uy·sin R (cancels at the edge), y' = uy·cos R + ux·sin R.
-    let xr = (data[c] - data[w]) + (data[c + 1u] - data[w + 1u]);
-    let yr = data[w + 2u] + data[c + 2u];
-    return atan2(xr, yr) * GEN_DEG;
-}
-
-// Radial Wipe. data: per column 9 floats (for each rotation: ux·cos R (hi, lo), ux·sin R),
-// per row 9 floats (uy·sin R (hi, lo), uy·cos R); u[0] = (row offset, wipe);
-// f[0] = (edge, feather).
+// Radial Wipe (effects::misc::radial_wipe_alpha). u[0] = (fully wiped, hard edge);
+// f[0] = (centre x, centre y, σ, first ray in degrees); f[1] = (sin, cos) of both rays;
+// f[2].x = span in degrees.
 @compute @workgroup_size(16, 16)
 fn gen_radial_wipe(@builtin(global_invocation_id) gid: vec3<u32>) {
     let dims = out_dims();
@@ -280,30 +291,31 @@ fn gen_radial_wipe(@builtin(global_invocation_id) gid: vec3<u32>) {
     if (p.x >= dims.x || p.y >= dims.y) {
         return;
     }
-    let x = u32(p.x);
-    let y = u32(p.y);
-    let dir = P.u[0].y;
-    let edge = P.f[0].x;
-    var a = gen_psi(0u, x, y);
-    if (a < 0.0) {
-        a += 360.0;
-    }
-    var base: f32;
-    if (dir == 0u || (dir == 2u && a <= 180.0)) {
-        base = a - edge;
-        if (abs(base) < 90.0) {
-            base = gen_psi(1u, x, y);
-        }
-    } else {
-        base = (360.0 - a) - edge;
-        if (abs(base) < 90.0) {
-            base = -gen_psi(2u, x, y);
+    var k = 0.0;
+    if (P.u[0].x == 0u) {
+        let ux = f32(p.x) + 0.5 - P.f[0].x;
+        let uy = f32(p.y) + 0.5 - P.f[0].y;
+        var a = atan2(ux, -uy) * GEN_DEG - P.f[0].w;
+        a = a - 360.0 * floor(a / 360.0);
+        let wiped = a < P.f[2].x;
+        let d = min(gen_ray_dist(ux, uy, P.f[1].x, P.f[1].y), gen_ray_dist(ux, uy, P.f[1].z, P.f[1].w));
+        if (P.u[0].y != 0u) {
+            k = select(1.0, 0.0, wiped);
+        } else {
+            k = gen_norm_cdf(select(d, -d, wiped) / P.f[0].z);
         }
     }
-    let k = clamp(base / P.f[0].y + 0.5, 0.0, 1.0);
     textureStore(out, p, textureLoad(src, p, 0) * k);
 }
 
+// Distance from (ux, uy) to the ray from the centre in direction (s, −c) (y down).
+fn gen_ray_dist(ux: f32, uy: f32, s: f32, c: f32) -> f32 {
+    if (ux * s - uy * c > 0.0) {
+        return abs(ux * c + uy * s);
+    }
+    return length(vec2<f32>(ux, uy));
+}
+
 // Gradient Wipe: aux = the placed gradient layer. u[0].x = invert; f[0] = (done, softness).
 @compute @workgroup_size(16, 16)
 fn gen_gradient_wipe(@builtin(global_invocation_id) gid: vec3<u32>) {
diff --git a/crates/gpu/src/shaders/fx_stylize.wgsl b/crates/gpu/src/shaders/fx_stylize.wgsl
index 3db442750..97db06c52 100644
--- a/crates/gpu/src/shaders/fx_stylize.wgsl
+++ b/crates/gpu/src/shaders/fx_stylize.wgsl
@@ -922,18 +922,28 @@ fn fxs_glow_map(@builtin(global_invocation_id) gid: vec3<u32>) {
     let k = clamp((l - thr) / max(1.0 - thr, 1e-3), 0.0, 1.0);
     let t = glow_ab_t(l);
     let c = vec3<f32>(curve_eval(P.f[1].x, t), curve_eval(P.f[1].y, t), curve_eval(P.f[1].z, t));
-    textureStore(out, p, vec4<f32>(c * k * a, k * a));
+    // Based on the colour channels the glow covers the layer's whole alpha (effects::misc::glow).
+    var ga = a;
+    if (P.u[0].y != 0u) {
+        ga = k * a;
+    }
+    textureStore(out, p, vec4<f32>(c * k * a, ga));
 }
 
 // On Top with another Glow Operation: blend_pixel(mode, original, glow · intensity, 0).
-// aux = the blurred glow; u[0].x = blend mode id; f[0].x = intensity
+// aux = the blurred glow; u[0].x = blend mode id; u[0].y = based on alpha (intensity also
+// scales the glow's alpha); f[0].x = intensity
 @compute @workgroup_size(16, 16)
 fn fxs_glow_op(@builtin(global_invocation_id) gid: vec3<u32>) {
     let p = vec2<i32>(gid.xy);
     if (!fxs_inside(p)) {
         return;
     }
-    let g = textureLoad(aux, p, 0) * P.f[0].x;
+    let gs = textureLoad(aux, p, 0);
+    var g = vec4<f32>(gs.xyz * P.f[0].x, gs.w);
+    if (P.u[0].y != 0u) {
+        g.w = gs.w * P.f[0].x;
+    }
     var o = blend_pixel(P.u[0].x, textureLoad(src, p, 0), g, 0.0);
     o.w = clamp(o.w, 0.0, 1.0);
     textureStore(out, p, o);
diff --git a/crates/gpu/src/shaders/kernels.wgsl b/crates/gpu/src/shaders/kernels.wgsl
index 5bb69693e..834c5f528 100644
--- a/crates/gpu/src/shaders/kernels.wgsl
+++ b/crates/gpu/src/shaders/kernels.wgsl
@@ -380,19 +380,31 @@ fn glow_bright(@builtin(global_invocation_id) gid: vec3<u32>) {
         l = a;
     }
     let k = clamp((l - thr) / max(1.0 - thr, 1e-3), 0.0, 1.0);
+    // Based on the colour channels the glow covers the layer's whole alpha (effects::misc::glow).
+    var ga = a;
+    if (P.u[0].y != 0u) {
+        ga = k * a;
+    }
     if (P.u[0].x != 0u) {
         let t = glow_ab_t(l);
         let ca = P.f[1].xyz;
         let cb = P.f[2].xyz;
         let c = ca + (cb - ca) * t;
-        textureStore(out, p, vec4<f32>(c * k * a, k * a));
+        textureStore(out, p, vec4<f32>(c * k * a, ga));
+    } else if (P.u[0].y != 0u) {
+        textureStore(out, p, vec4<f32>(px.xyz * k, ga));
     } else {
-        textureStore(out, p, px * k);
+        // Original colours, per channel (effects::misc::glow_bright_channel): gain 8.0 is
+        // effects::GLOW_GAIN, 0.0611 is effects::GLOW_KNEE (checked by the test
+        // glow_constants_match_the_cpu).
+        let c = max(8.0 * (px.xyz / a - vec3<f32>(thr - 0.0611)), vec3<f32>(0.0));
+        textureStore(out, p, vec4<f32>(c * a, ga));
     }
 }
 
 // Glow composite: original `src` with the blurred glow `aux`. u[0].x = 0 on top, 1 behind,
-// 2 none (glow only); f[0].x = intensity.
+// 2 none (glow only); u[0].y = based on alpha (intensity also scales the glow's alpha);
+// f[0].x = intensity.
 @compute @workgroup_size(16, 16)
 fn glow_combine(@builtin(global_invocation_id) gid: vec3<u32>) {
     let dims = out_dims();
@@ -401,7 +413,11 @@ fn glow_combine(@builtin(global_invocation_id) gid: vec3<u32>) {
         return;
     }
     var o = textureLoad(src, p, 0);
-    let g = textureLoad(aux, p, 0) * P.f[0].x;
+    let gs = textureLoad(aux, p, 0);
+    var g = vec4<f32>(gs.xyz * P.f[0].x, gs.w);
+    if (P.u[0].y != 0u) {
+        g.w = gs.w * P.f[0].x;
+    }
     if (P.u[0].x == 2u) {
         o = g;
     } else if (P.u[0].x == 1u) {
diff --git a/crates/gpu/src/shaders/yuv.wgsl b/crates/gpu/src/shaders/yuv.wgsl
new file mode 100644
index 000000000..935acb4dc
--- /dev/null
+++ b/crates/gpu/src/shaders/yuv.wgsl
@@ -0,0 +1,96 @@
+// Finished frame → 8-bit BT.709 limited-range 4:2:0 (Y, U, V planes packed 4 bytes per word),
+// composited over the comp background: the GPU twin of `Image::to_rgba8_over` followed by
+// export's `rgba_to_yuv420`, operation for operation (same order of float operations, the same
+// rounding: `as u8` truncation of `x * 255 + 0.5`, `f32::round` half away from zero).
+
+struct YP {
+    // width, height, chroma width, Y words
+    size: vec4<u32>,
+    bg: vec4<f32>,
+}
+
+@group(0) @binding(0) var<uniform> Y: YP;
+@group(0) @binding(1) var frame: texture_2d<f32>;
+@group(0) @binding(2) var<storage, read_write> outw: array<u32>;
+
+// NaN by its bits: drivers may assume arithmetic never sees NaN.
+fn is_nan(x: f32) -> bool {
+    return (bitcast<u32>(x) & 0x7fffffffu) > 0x7f800000u;
+}
+
+// `(c.clamp(0, 1) * 255 + 0.5) as u8`; the CPU's `as u8` turns NaN into 0.
+fn q8(c: f32, nan: bool) -> f32 {
+    if (nan) {
+        return 0.0;
+    }
+    return floor(clamp(c, 0.0, 1.0) * 255.0 + 0.5);
+}
+
+// f32::round for x >= 0 (half away from zero).
+fn round_pos(x: f32) -> f32 {
+    let f = floor(x);
+    return select(f, f + 1.0, x - f >= 0.5);
+}
+
+fn px(x: u32, y: u32) -> vec3<f32> {
+    let p = textureLoad(frame, vec2<i32>(i32(x), i32(y)), 0);
+    // A NaN alpha makes every channel NaN on the CPU (k is NaN).
+    let na = is_nan(p.w);
+    let k = select(1.0 - clamp(p.w, 0.0, 1.0), 0.0, na);
+    let c = vec3<f32>(q8(p.x + Y.bg.x * k, na || is_nan(p.x)), q8(p.y + Y.bg.y * k, na || is_nan(p.y)), q8(p.z + Y.bg.z * k, na || is_nan(p.z)));
+    return c / 255.0;
+}
+
+fn luma(c: vec3<f32>) -> f32 {
+    return 0.2126 * c.x + 0.7152 * c.y + 0.0722 * c.z;
+}
+
+fn y8(l: f32) -> u32 {
+    return u32(clamp(round_pos(16.0 + 219.0 * l), 1.0, 254.0));
+}
+
+// One invocation: 4 chroma samples = 8 × 2 pixels.
+@compute @workgroup_size(8, 8)
+fn yuv420(@builtin(global_invocation_id) gid: vec3<u32>) {
+    let w = Y.size.x;
+    let h = Y.size.y;
+    let cw = Y.size.z;
+    if (gid.x * 4u >= cw || gid.y * 2u >= h) {
+        return;
+    }
+    let x0 = gid.x * 8u;
+    let cy = gid.y;
+    var uw = 0u;
+    var vw = 0u;
+    var yw = array<u32, 4>(0u, 0u, 0u, 0u);
+    for (var q = 0u; q < 4u; q++) {
+        // Accumulate in the CPU's order: row 0 left, right; row 1 left, right.
+        var a0 = 0.0;
+        var a1 = 0.0;
+        for (var dy = 0u; dy < 2u; dy++) {
+            for (var dx = 0u; dx < 2u; dx++) {
+                let x = x0 + q * 2u + dx;
+                let c = px(x, cy * 2u + dy);
+                let l = luma(c);
+                let byte = q * 2u + dx;
+                yw[dy * 2u + byte / 4u] |= y8(l) << (8u * (byte % 4u));
+                a0 += (c.z - l) / 1.8556;
+                a1 += (c.x - l) / 1.5748;
+            }
+        }
+        let u = u32(clamp(round_pos(128.0 + 224.0 * a0 / 4.0), 1.0, 254.0));
+        let v = u32(clamp(round_pos(128.0 + 224.0 * a1 / 4.0), 1.0, 254.0));
+        uw |= u << (8u * q);
+        vw |= v << (8u * q);
+    }
+    let r0 = (cy * 2u * w + x0) / 4u;
+    let r1 = ((cy * 2u + 1u) * w + x0) / 4u;
+    outw[r0] = yw[0];
+    outw[r0 + 1u] = yw[1];
+    outw[r1] = yw[2];
+    outw[r1 + 1u] = yw[3];
+    let cwords = cw / 4u * (h / 2u);
+    let ci = (cy * cw) / 4u + gid.x;
+    outw[Y.size.w + ci] = uw;
+    outw[Y.size.w + cwords + ci] = vw;
+}
diff --git a/crates/gpu/src/tests.rs b/crates/gpu/src/tests.rs
index 6c7b3ffb2..4b3375411 100644
--- a/crates/gpu/src/tests.rs
+++ b/crates/gpu/src/tests.rs
@@ -26,6 +26,36 @@ use effectcraft_time::{FrameRate, Tick};
 
 use crate::Gpu;
 
+mod adjust;
+mod adv3d;
+mod deferred;
+mod deferred_jobs;
+mod fx_color;
+mod fx_depth;
+mod fx_distort;
+mod fx_extra;
+mod fx_gen2;
+mod fx_generate;
+mod fx_key;
+mod fx_light;
+mod fx_lut;
+mod fx_noise;
+mod fx_particles;
+mod fx_pixel2;
+mod fx_sim;
+mod fx_stylize;
+mod fx_text;
+mod fx_time;
+mod fx_tone;
+mod fx_transition;
+mod fx_vr;
+mod fx_warp;
+#[cfg(all(test, not(target_arch = "wasm32")))]
+mod init;
+mod particles;
+mod three_d;
+mod wgsl_grammar;
+
 /// One GPU test at a time in this process: the calling test thread holds a process-wide lock
 /// until it exits (libtest runs every test on a thread of its own). wgpu's OpenGL backend (Mesa
 /// llvmpipe on FreeBSD, Linux without Vulkan) has one context lock per adapter and panics when a
@@ -928,6 +958,16 @@ fn effects_whose_kernels_failed_render_on_the_cpu() {
     }
 }
 
+/// WGSL cannot read the CPU's constants, so Glow's bright pass repeats them as literals; this
+/// ties them to `effects::GLOW_GAIN` / `GLOW_KNEE` (runs without a GPU).
+#[test]
+fn glow_constants_match_the_cpu() {
+    use effectcraft_effects::{GLOW_GAIN, GLOW_KNEE};
+    let kernels = include_str!("shaders/kernels.wgsl");
+    let want = format!("max({GLOW_GAIN:?} * (px.xyz / a - vec3<f32>(thr - {GLOW_KNEE:?})), vec3<f32>(0.0))");
+    assert!(kernels.contains(&want), "Glow's bright pass in kernels.wgsl is not `{want}`");
+}
+
 /// The GPU Tint gives After Effects 2026's greys for full-frame solids at its defaults (sRGB
 /// working space, not linearised): Rec. 601 weights, as the CPU (`color_fx::luma_601`).
 #[test]
diff --git a/crates/gpu/src/tests_adjust.rs b/crates/gpu/src/tests/adjust.rs
similarity index 100%
rename from crates/gpu/src/tests_adjust.rs
rename to crates/gpu/src/tests/adjust.rs
diff --git a/crates/gpu/src/tests_adv3d.rs b/crates/gpu/src/tests/adv3d.rs
similarity index 100%
rename from crates/gpu/src/tests_adv3d.rs
rename to crates/gpu/src/tests/adv3d.rs
diff --git a/crates/gpu/src/tests_deferred.rs b/crates/gpu/src/tests/deferred.rs
similarity index 100%
rename from crates/gpu/src/tests_deferred.rs
rename to crates/gpu/src/tests/deferred.rs
diff --git a/crates/gpu/src/tests_deferred_jobs.rs b/crates/gpu/src/tests/deferred_jobs.rs
similarity index 95%
rename from crates/gpu/src/tests_deferred_jobs.rs
rename to crates/gpu/src/tests/deferred_jobs.rs
index 7f10f53d4..7e5edbedd 100644
--- a/crates/gpu/src/tests_deferred_jobs.rs
+++ b/crates/gpu/src/tests/deferred_jobs.rs
@@ -8,10 +8,10 @@ use effectcraft_render::three_d::adv;
 use effectcraft_render::{Accelerator, Backend, LayerCache, NoFootage, RenderOpts, Renderer};
 use effectcraft_time::Tick;
 
+use crate::tests::adv3d::{off_share, run_of, scene, scene_project};
+use crate::tests::deferred::{deferred_gpu, render_passes};
+use crate::tests::particles::{Host, agree, params};
 use crate::tests::{Pattern, diff, n, tolerance};
-use crate::tests_adv3d::{off_share, run_of, scene, scene_project};
-use crate::tests_deferred::{deferred_gpu, render_passes};
-use crate::tests_particles::{Host, agree, params};
 
 /// The device's readbacks have landed (the browser's event loop; natively a poll).
 fn settle(g: &crate::Gpu) {
@@ -87,7 +87,7 @@ fn advanced_3d_resolves_in_passes() {
 #[test]
 fn job_frames_render_in_passes() {
     let Some((g, _lock)) = deferred_gpu() else { return };
-    let s = crate::tests_deferred::scene();
+    let s = crate::tests::deferred::scene();
     let t = Tick::from_seconds_f64(0.5);
     let cache = LayerCache::default();
     cache.set_gate(g.miss_gate());
diff --git a/crates/gpu/src/tests_fx_color.rs b/crates/gpu/src/tests/fx_color.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_color.rs
rename to crates/gpu/src/tests/fx_color.rs
diff --git a/crates/gpu/src/tests_fx_depth.rs b/crates/gpu/src/tests/fx_depth.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_depth.rs
rename to crates/gpu/src/tests/fx_depth.rs
diff --git a/crates/gpu/src/tests_fx_distort.rs b/crates/gpu/src/tests/fx_distort.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_distort.rs
rename to crates/gpu/src/tests/fx_distort.rs
diff --git a/crates/gpu/src/tests_fx_extra.rs b/crates/gpu/src/tests/fx_extra.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_extra.rs
rename to crates/gpu/src/tests/fx_extra.rs
diff --git a/crates/gpu/src/tests_fx_gen2.rs b/crates/gpu/src/tests/fx_gen2.rs
similarity index 99%
rename from crates/gpu/src/tests_fx_gen2.rs
rename to crates/gpu/src/tests/fx_gen2.rs
index 8eba75c8c..620cced13 100644
--- a/crates/gpu/src/tests_fx_gen2.rs
+++ b/crates/gpu/src/tests/fx_gen2.rs
@@ -7,8 +7,8 @@
 use effectcraft_keyframe::Value;
 use effectcraft_time::Tick;
 
+use crate::tests::fx_pixel2::{e, env_case, env_case_allow, env_case_at, off, on, pt};
 use crate::tests::{c, n};
-use crate::tests_fx_pixel2::{e, env_case, env_case_allow, env_case_at, off, on, pt};
 
 fn layer(id: u64) -> Value {
     Value::Layer(Some(id))
diff --git a/crates/gpu/src/tests_fx_generate.rs b/crates/gpu/src/tests/fx_generate.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_generate.rs
rename to crates/gpu/src/tests/fx_generate.rs
diff --git a/crates/gpu/src/tests_fx_key.rs b/crates/gpu/src/tests/fx_key.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_key.rs
rename to crates/gpu/src/tests/fx_key.rs
diff --git a/crates/gpu/src/tests_fx_light.rs b/crates/gpu/src/tests/fx_light.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_light.rs
rename to crates/gpu/src/tests/fx_light.rs
diff --git a/crates/gpu/src/tests_fx_lut.rs b/crates/gpu/src/tests/fx_lut.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_lut.rs
rename to crates/gpu/src/tests/fx_lut.rs
diff --git a/crates/gpu/src/tests_fx_noise.rs b/crates/gpu/src/tests/fx_noise.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_noise.rs
rename to crates/gpu/src/tests/fx_noise.rs
diff --git a/crates/gpu/src/tests_fx_particles.rs b/crates/gpu/src/tests/fx_particles.rs
similarity index 99%
rename from crates/gpu/src/tests_fx_particles.rs
rename to crates/gpu/src/tests/fx_particles.rs
index b67df9a43..e8c3a7ce6 100644
--- a/crates/gpu/src/tests_fx_particles.rs
+++ b/crates/gpu/src/tests/fx_particles.rs
@@ -7,8 +7,8 @@ use effectcraft_project::{BitDepth, LayerSource, build};
 use effectcraft_render::RenderOpts;
 use effectcraft_time::Tick;
 
+use crate::tests::fx_sim::{case, composited, e, off, on};
 use crate::tests::{Scene, check, compare_at, n, opts, set};
-use crate::tests_fx_sim::{case, composited, e, off, on};
 
 fn v2(x: f64, y: f64) -> Value {
     Value::Vec2([x, y])
diff --git a/crates/gpu/src/tests_fx_pixel2.rs b/crates/gpu/src/tests/fx_pixel2.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_pixel2.rs
rename to crates/gpu/src/tests/fx_pixel2.rs
diff --git a/crates/gpu/src/tests_fx_sim.rs b/crates/gpu/src/tests/fx_sim.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_sim.rs
rename to crates/gpu/src/tests/fx_sim.rs
diff --git a/crates/gpu/src/tests_fx_stylize.rs b/crates/gpu/src/tests/fx_stylize.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_stylize.rs
rename to crates/gpu/src/tests/fx_stylize.rs
diff --git a/crates/gpu/src/tests_fx_text.rs b/crates/gpu/src/tests/fx_text.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_text.rs
rename to crates/gpu/src/tests/fx_text.rs
diff --git a/crates/gpu/src/tests_fx_time.rs b/crates/gpu/src/tests/fx_time.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_time.rs
rename to crates/gpu/src/tests/fx_time.rs
diff --git a/crates/gpu/src/tests_fx_tone.rs b/crates/gpu/src/tests/fx_tone.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_tone.rs
rename to crates/gpu/src/tests/fx_tone.rs
diff --git a/crates/gpu/src/tests_fx_transition.rs b/crates/gpu/src/tests/fx_transition.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_transition.rs
rename to crates/gpu/src/tests/fx_transition.rs
diff --git a/crates/gpu/src/tests_fx_vr.rs b/crates/gpu/src/tests/fx_vr.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_vr.rs
rename to crates/gpu/src/tests/fx_vr.rs
diff --git a/crates/gpu/src/tests_fx_warp.rs b/crates/gpu/src/tests/fx_warp.rs
similarity index 100%
rename from crates/gpu/src/tests_fx_warp.rs
rename to crates/gpu/src/tests/fx_warp.rs
diff --git a/crates/gpu/src/tests_init.rs b/crates/gpu/src/tests/init.rs
similarity index 89%
rename from crates/gpu/src/tests_init.rs
rename to crates/gpu/src/tests/init.rs
index 9c579ae69..4578a8489 100644
--- a/crates/gpu/src/tests_init.rs
+++ b/crates/gpu/src/tests/init.rs
@@ -2,7 +2,6 @@
 //! Set EFFECTCRAFT_REQUIRE_GPU=1 for acceptance: unavailable adapters/devices then fail
 //! instead of taking the explicitly logged headless-CI skip path.
 #![cfg(not(target_arch = "wasm32"))]
-#![allow(clippy::expect_used)] // Test helpers require successful setup to exercise rejection.
 
 use std::sync::Arc;
 use std::sync::atomic::{AtomicUsize, Ordering};
@@ -149,23 +148,28 @@ fn opengl_adapters_get_cpu_compositing_at_once() {
     assert!(t.elapsed() < std::time::Duration::from_secs(1), "{:?}", t.elapsed());
 }
 
+/// #613: FXC (DirectX 12's default shader compiler) builds Classic 3D, so the compositor starts
+/// on DirectX 12 with its 3D kernel, and initialization leaves the caller's error scope and the
+/// host's error handler untouched. Ignored by default: FXC compiles every kernel, which takes
+/// minutes. Skips where there is no DirectX 12 adapter.
 #[test]
 #[cfg(target_os = "windows")]
-#[ignore = "requires the reproduced Windows DX12/FXC pointwise compiler failure; no adapter skips"]
-fn reproduced_fxc_pointwise_failure_returns_error_without_escaping_or_notifying_host() {
+#[ignore = "slow: FXC compiles every kernel"]
+fn fxc_builds_classic3d_and_initialization_errors_stay_scoped() {
     let mut desc = wgpu::InstanceDescriptor::new_without_display_handle();
     desc.backends = wgpu::Backends::DX12;
     desc.backend_options.dx12.shader_compiler = wgpu::Dx12Compiler::Fxc;
-    let (adapter, device, queue) = native_device(desc, true).expect("required DX12 device");
+    let Some((adapter, device, queue)) = native_device(desc, false) else { return };
     assert_eq!(adapter.get_info().backend, wgpu::Backend::Dx12);
     let host = count_host_errors(&device);
     let outer = device.push_error_scope(wgpu::ErrorFilter::Validation);
     let result = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| GpuContext::new(&adapter, device.clone(), queue)));
-    let error = match result.expect("FXC compiler failure must not escape the constructor") {
-        Err(error) => error,
-        Ok(_) => panic!("the platform-specific FXC failure no longer reproduces; reassess this diagnostic"),
+    let ctx = match result.expect("an FXC compiler failure must not escape the constructor") {
+        Ok(ctx) => ctx,
+        Err(error) => panic!("the compositor starts on DirectX 12 with FXC: {}", brief(error)),
     };
-    assert!(error.contains("GPU initialization (pointwise)") && error.contains("FXC D3DCompile"), "{}", brief(error));
+    let missing: Vec<&str> = ctx.unavailable_kernels().iter().map(|(e, _)| *e).collect();
+    assert!(ctx.has_kernel("classic3d"), "FXC builds classic3d (unavailable: {missing:?})");
     assert!(pollster::block_on(outer.pop()).is_none(), "constructor must drain its own scopes and leave the caller's scope clean");
     assert_eq!(host.load(Ordering::SeqCst), 0);
     valid_pipeline(&device);
diff --git a/crates/gpu/src/tests_particles.rs b/crates/gpu/src/tests/particles.rs
similarity index 100%
rename from crates/gpu/src/tests_particles.rs
rename to crates/gpu/src/tests/particles.rs
diff --git a/crates/gpu/src/tests_3d.rs b/crates/gpu/src/tests/three_d.rs
similarity index 89%
rename from crates/gpu/src/tests_3d.rs
rename to crates/gpu/src/tests/three_d.rs
index bd9455b9e..32f11a341 100644
--- a/crates/gpu/src/tests_3d.rs
+++ b/crates/gpu/src/tests/three_d.rs
@@ -11,7 +11,7 @@ use effectcraft_project::{BitDepth, Comp, ItemKind, Layer, LayerSource, LightKin
 use effectcraft_render::{Backend, RenderOpts, Renderer};
 use effectcraft_time::{FrameRate, Tick};
 
-use crate::tests::{Pattern, Scene, check, compare_at, gpu, n, opts, set};
+use crate::tests::{Pattern, Scene, check, compare_at, diff, gpu, n, opts, set, tolerance};
 
 const W: u32 = 160;
 const H: u32 = 100;
@@ -209,6 +209,10 @@ fn the_gpu_draws_classic_3d_runs_itself() {
     assert_eq!(prep.planes.iter().filter(|p| p.draw).count(), 3);
     let mut e = crate::context::Enc::new(g.context());
     let canvas = e.image(W, H);
+    if !g.context().has_kernel("classic3d") {
+        // FXC (DirectX 12) can't build the kernel (#613); the CPU fallback is tested below.
+        return;
+    }
     let out = crate::classic3d::draw_run(&mut e, &prep, &canvas).expect("the kernel draws the run");
     let img = e.download(&out).unwrap();
     let mut cpu = effectcraft_raster::Image::new(W, H);
@@ -253,7 +257,9 @@ fn bokeh_depth_of_field_runs_on_the_gpu() {
                 assert!(prep.planes.iter().filter(|p| p.draw).all(|p| p.dof.is_some()), "{label}: depth of field deferred to the GPU");
                 let mut e = crate::context::Enc::new(g.context());
                 let canvas = e.image(W, H);
-                assert!(crate::classic3d::draw_run(&mut e, &prep, &canvas).is_some(), "{label}: drawn on the GPU");
+                if g.context().has_kernel("classic3d") {
+                    assert!(crate::classic3d::draw_run(&mut e, &prep, &canvas).is_some(), "{label}: drawn on the GPU");
+                }
             }
         }
     }
@@ -288,3 +294,27 @@ fn two_d_layer_with_a_three_d_track_matte() {
         }
     }
 }
+
+/// #613: FXC on DirectX 12 fails to build `classic3d` (it can't unroll its loops). The
+/// compositor still starts without it, lists it, and 3D runs render on the CPU, matching the
+/// CPU render.
+#[test]
+fn classic_3d_runs_render_on_the_cpu_without_the_kernel() {
+    let Some(base) = gpu() else {
+        return;
+    };
+    let ctx = base.context().without_kernel("classic3d");
+    assert!(!ctx.has_kernel("classic3d"));
+    let g = crate::Gpu::from_context(ctx);
+    for depth in [BitDepth::Bpc8, BitDepth::Bpc32] {
+        let mut s = crossing(depth, BlendMode::Normal);
+        camera(&mut s, [30.0, 20.0, -260.0], None);
+        let cpu = Renderer::new(&s.p, &Pattern, RenderOpts { backend: Backend::Cpu, ..opts() }).comp_frame_cpu(s.cid, Tick::ZERO);
+        let mut r = Renderer::new(&s.p, &Pattern, RenderOpts { backend: Backend::Gpu, ..opts() });
+        r.accel = Some(&g);
+        let img = g.render(&r, s.cid, Tick::ZERO).expect("the GPU renders the frame");
+        let mut d = diff(&cpu, &img, tolerance(depth));
+        d.quantized = depth != BitDepth::Bpc32;
+        check(&format!("classic 3D without its kernel {depth:?}"), Some(d), 0.0);
+    }
+}
diff --git a/crates/gpu/src/tests_wgsl_grammar.rs b/crates/gpu/src/tests/wgsl_grammar.rs
similarity index 100%
rename from crates/gpu/src/tests_wgsl_grammar.rs
rename to crates/gpu/src/tests/wgsl_grammar.rs
diff --git a/crates/gpu/src/walk.rs b/crates/gpu/src/walk.rs
index b6e78870c..78a6857fb 100644
--- a/crates/gpu/src/walk.rs
+++ b/crates/gpu/src/walk.rs
@@ -17,6 +17,12 @@ use effectcraft_time::Tick;
 use crate::context::{Enc, GpuImage};
 use crate::ops;
 
+/// The size [`render`] renders `comp_id` at, without rendering it.
+pub(crate) fn frame_size(r: &Renderer, comp_id: ItemId, t: Tick) -> Option<(u32, u32)> {
+    let ctx = r.eval_ctx(comp_id, t)?;
+    Some(effectcraft_render::frame_size(ctx.comp.width, ctx.comp.height, r.opts.scale))
+}
+
 /// Render a comp frame into a GPU image (the canvas in the output space, as
 /// `Renderer::comp_frame_cpu` returns it). `None` when something cannot run here (the caller
 /// renders on the CPU instead).
@@ -466,12 +472,12 @@ fn place_src(
 ) -> Option<GpuImage> {
     let pl = r.placement(ctx, layer, buf);
     if let [m] = pl.matrices.as_slice() {
-        return Some(ops::warp_q(e, target, &src, m, pl.sampling, mode, opacity, pl.seed, None, levels));
+        return Some(ops::warp_q(e, target, &src, m, ops::WarpOptions { sampling: pl.sampling, mode, opacity, seed: pl.seed }, None, levels));
     }
     let mut acc = e.zeros(target.width, target.height);
     let k = 1.0 / pl.matrices.len() as f32;
     for m in &pl.matrices {
-        acc = ops::warp(e, &acc, &src, m, pl.sampling, BlendMode::Normal, 1.0, 0, Some(k));
+        acc = ops::warp(e, &acc, &src, m, ops::WarpOptions { sampling: pl.sampling, mode: BlendMode::Normal, opacity: 1.0, seed: 0 }, Some(k));
     }
     Some(ops::blend_full(e, target, &acc, mode, opacity, pl.seed, levels))
 }
diff --git a/crates/gpu/src/yuv.rs b/crates/gpu/src/yuv.rs
new file mode 100644
index 000000000..aba3ec700
--- /dev/null
+++ b/crates/gpu/src/yuv.rs
@@ -0,0 +1,403 @@
+//! Export frames converted on the device to the H.264 encoder's input (8-bit BT.709 limited
+//! range 4:2:0, see `shaders/yuv.wgsl`): a 4K frame reads back 12 MB of planes instead of
+//! 133 MB of RGBA f32, and the CPU skips `to_rgba8_over` + `rgba_to_yuv420`.
+
+use wgpu::util::DeviceExt;
+
+use crate::context::{Enc, GpuImage};
+
+pub(crate) struct YuvPipe {
+    bgl: wgpu::BindGroupLayout,
+    pipe: wgpu::ComputePipeline,
+}
+
+impl YuvPipe {
+    pub(crate) fn new(device: &wgpu::Device) -> Result<YuvPipe, String> {
+        crate::context::init_resource(device, "yuv420", || {
+            let module = device.create_shader_module(wgpu::ShaderModuleDescriptor {
+                label: Some("yuv420"),
+                source: wgpu::ShaderSource::Wgsl(include_str!("shaders/yuv.wgsl").into()),
+            });
+            let storage =
+                wgpu::BindingType::Buffer { ty: wgpu::BufferBindingType::Storage { read_only: false }, has_dynamic_offset: false, min_binding_size: None };
+            let bgl = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
+                label: Some("yuv420"),
+                entries: &[
+                    wgpu::BindGroupLayoutEntry {
+                        binding: 0,
+                        visibility: wgpu::ShaderStages::COMPUTE,
+                        ty: wgpu::BindingType::Buffer { ty: wgpu::BufferBindingType::Uniform, has_dynamic_offset: false, min_binding_size: None },
+                        count: None,
+                    },
+                    wgpu::BindGroupLayoutEntry {
+                        binding: 1,
+                        visibility: wgpu::ShaderStages::COMPUTE,
+                        ty: wgpu::BindingType::Texture {
+                            sample_type: wgpu::TextureSampleType::Float { filterable: false },
+                            view_dimension: wgpu::TextureViewDimension::D2,
+                            multisampled: false,
+                        },
+                        count: None,
+                    },
+                    wgpu::BindGroupLayoutEntry { binding: 2, visibility: wgpu::ShaderStages::COMPUTE, ty: storage, count: None },
+                ],
+            });
+            let layout =
+                device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor { label: Some("yuv420"), bind_group_layouts: &[Some(&bgl)], immediate_size: 0 });
+            let pipe = device.create_compute_pipeline(&wgpu::ComputePipelineDescriptor {
+                label: Some("yuv420"),
+                layout: Some(&layout),
+                module: &module,
+                entry_point: Some("yuv420"),
+                compilation_options: Default::default(),
+                cache: None,
+            });
+            YuvPipe { bgl, pipe }
+        })
+    }
+}
+
+/// The frame sizes the kernel handles: width a multiple of 8 (4 chroma samples per
+/// invocation), height even.
+pub(crate) fn supported(w: u32, h: u32) -> bool {
+    w > 0 && h > 0 && w.is_multiple_of(8) && h.is_multiple_of(2)
+}
+
+/// Bytes of the planes: Y `w×h`, then U and V `w/2 × h/2`.
+pub(crate) fn planes_len(w: u32, h: u32) -> u64 {
+    w as u64 * h as u64 + 2 * ((w / 2) as u64 * (h / 2) as u64)
+}
+
+/// Whether the [`planes_len`] storage and staging buffers for `w×h` fit within `limits`.
+pub(crate) fn fits_limits(w: u32, h: u32, limits: &wgpu::Limits) -> bool {
+    let size = planes_len(w, h);
+    size <= limits.max_storage_buffer_binding_size && size <= limits.max_buffer_size
+}
+
+/// Record the conversion of `img` over `bg` into a new `MAP_READ` buffer of
+/// [`planes_len`] bytes and submit it. `None`: the size is not [`supported`], exceeds the
+/// device's buffer limits, or buffer allocation failed.
+pub(crate) fn record(e: &mut Enc, yp: &YuvPipe, img: &GpuImage, bg: [f32; 3]) -> Option<wgpu::Buffer> {
+    let (w, h) = (img.width, img.height);
+    let g = e.g;
+    if !supported(w, h) || !fits_limits(w, h, &g.device.limits()) {
+        return None;
+    }
+    let cw = w / 2;
+    let size = planes_len(w, h);
+    let mut params = [0u8; 32];
+    // w * h fits in u32: both are at most the texture limit (16384).
+    for (i, v) in [w, h, cw, w * h / 4].into_iter().enumerate() {
+        params[i * 4..i * 4 + 4].copy_from_slice(&v.to_le_bytes());
+    }
+    for (i, v) in [bg[0], bg[1], bg[2], 1.0].into_iter().enumerate() {
+        params[16 + i * 4..16 + i * 4 + 4].copy_from_slice(&v.to_le_bytes());
+    }
+    let (out, stg, ub) = match crate::context::init_resource(&g.device, "yuv420 buffers", || {
+        let out = g.device.create_buffer(&wgpu::BufferDescriptor {
+            label: Some("yuv420 out"),
+            size,
+            usage: wgpu::BufferUsages::STORAGE | wgpu::BufferUsages::COPY_SRC,
+            mapped_at_creation: false,
+        });
+        let stg = g.device.create_buffer(&wgpu::BufferDescriptor {
+            label: Some("yuv420 staging"),
+            size,
+            usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
+            mapped_at_creation: false,
+        });
+        let ub = g.device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
+            label: Some("yuv420 params"),
+            contents: &params,
+            usage: wgpu::BufferUsages::UNIFORM,
+        });
+        (out, stg, ub)
+    }) {
+        Ok(buffers) => buffers,
+        Err(err) => {
+            log::warn!(target: "effectcraft_gpu", "yuv420 buffers: {err}");
+            return None;
+        }
+    };
+    let view = img.texture.create_view(&Default::default());
+    let group = g.device.create_bind_group(&wgpu::BindGroupDescriptor {
+        label: Some("yuv420"),
+        layout: &yp.bgl,
+        entries: &[
+            wgpu::BindGroupEntry { binding: 0, resource: ub.as_entire_binding() },
+            wgpu::BindGroupEntry { binding: 1, resource: wgpu::BindingResource::TextureView(&view) },
+            wgpu::BindGroupEntry { binding: 2, resource: out.as_entire_binding() },
+        ],
+    });
+    {
+        let enc = e.encoder();
+        {
+            let mut pass = enc.begin_compute_pass(&wgpu::ComputePassDescriptor { label: Some("yuv420"), timestamp_writes: None });
+            pass.set_pipeline(&yp.pipe);
+            pass.set_bind_group(0, &group, &[]);
+            pass.dispatch_workgroups((w / 8).div_ceil(8), (h / 2).div_ceil(8), 1);
+        }
+        enc.copy_buffer_to_buffer(&out, 0, &stg, 0, size);
+    }
+    e.submit();
+    Some(stg)
+}
+
+/// Convert `img` over `bg` and read the planes back, waiting for the device.
+pub(crate) fn convert(e: &mut Enc, yp: &YuvPipe, img: &GpuImage, bg: [f32; 3]) -> Option<Vec<u8>> {
+    let stg = record(e, yp, img, bg)?;
+    let n = planes_len(img.width, img.height) as usize;
+    e.g.read_buffer(&stg, n, n, 1).map_err(|err| log::error!(target: "effectcraft_gpu", "yuv420 readback: {err}")).ok()
+}
+
+#[cfg(test)]
+pub(crate) mod tests {
+    use effectcraft_raster::Image;
+
+    /// The export's conversion (`to_rgba8_over` + `rgba_to_yuv420`), the reference the kernel
+    /// is held to.
+    pub(crate) fn cpu(img: &Image, bg: [f32; 3]) -> Vec<u8> {
+        effectcraft_raster::yuv::yuv420_over(img, bg)
+    }
+
+    /// Premultiplied noise with some out-of-range values, opaque pixels, exact 8-bit levels and
+    /// a few NaN and infinite components (the CPU writes 0 for NaN).
+    pub(crate) fn noise(w: u32, h: u32, seed: u32) -> Image {
+        let mut img = Image::new(w, h);
+        let mut s = seed | 1;
+        let mut rnd = || {
+            s ^= s << 13;
+            s ^= s >> 17;
+            s ^= s << 5;
+            s as f32 / u32::MAX as f32
+        };
+        for (i, p) in img.data.iter_mut().enumerate() {
+            let a = if i % 7 == 0 { 1.0 } else { rnd() };
+            *p = if i % 97 == 3 {
+                [f32::NAN, 0.5, f32::INFINITY, a]
+            } else if i % 101 == 5 {
+                [0.2, 0.3, 0.4, f32::NAN]
+            } else if i % 103 == 7 {
+                [f32::NEG_INFINITY, 0.1, 0.9, f32::INFINITY]
+            } else if i % 5 == 0 {
+                let q = (i % 256) as f32 / 255.0;
+                [q, 1.0 - q, q * 0.5, 1.0]
+            } else {
+                [rnd() * a * 1.1 - 0.02, rnd() * a, rnd() * a, a]
+            };
+        }
+        img
+    }
+
+    /// Check `got` against the CPU's `want`. Software adapters (llvmpipe, WARP) must match
+    /// exactly. A hardware driver may contract multiply-adds or divide less exactly, which
+    /// moves a value near a rounding boundary by one level (seen on an RTX 3090 under Vulkan):
+    /// there every byte must be within one level and at most `budget` of them off (about 2–3×
+    /// the rate measured on the 3090). A wrong formula, rounding mode or NaN rule fails either
+    /// way on software adapters.
+    pub(crate) fn assert_parity(g: &crate::Gpu, got: &[u8], want: &[u8], budget: f64, what: &str) {
+        assert_eq!(got.len(), want.len(), "{what}: length");
+        let diff: Vec<usize> = (0..got.len()).filter(|&i| got[i] != want[i]).collect();
+        let max = diff.iter().map(|&i| (got[i] as i32 - want[i] as i32).abs()).max().unwrap_or(0);
+        eprintln!("{what} on {}: {} of {} bytes differ (max {max})", g.ctx.name, diff.len(), got.len());
+        if g.ctx.software {
+            assert!(diff.is_empty(), "{what}: a software adapter must match exactly, first diffs at {:?}", &diff[..diff.len().min(10)]);
+            return;
+        }
+        assert!(max <= 1, "{what}: a byte is {max} levels off, first diffs at {:?}", &diff[..diff.len().min(10)]);
+        assert!(diff.len() as f64 <= budget * got.len() as f64, "{what}: {} of {} bytes off by one", diff.len(), got.len());
+    }
+
+    #[test]
+    fn yuv420_matches_cpu() {
+        let Some(g) = crate::tests::gpu() else { return };
+        let yp = super::YuvPipe::new(&g.ctx.device).expect("yuv420 pipe");
+        for (w, h, bg) in [(264u32, 150u32, [0.05, 0.1, 0.2]), (8, 2, [1.0, 1.0, 1.0]), (1928, 6, [0.0, 0.0, 0.0])] {
+            let img = noise(w, h, w ^ (h << 16));
+            let src = g.ctx.upload_image(&img).expect("upload");
+            let got = super::convert(&mut crate::context::Enc::new(&g.ctx), &yp, &src, bg).expect("readback");
+            assert_parity(g, &got, &cpu(&img, bg), 0.00005, &format!("noise {w}x{h}"));
+        }
+    }
+
+    #[test]
+    fn unsupported_sizes_are_declined() {
+        assert!(super::supported(8, 2));
+        for (w, h) in [(0, 2), (8, 0), (12, 2), (8, 3), (7, 4)] {
+            assert!(!super::supported(w, h), "{w}x{h}");
+        }
+        assert_eq!(super::planes_len(8, 2), 16 + 2 * 4);
+    }
+
+    #[test]
+    fn sizes_exceeding_buffer_limits_are_declined() {
+        let def = wgpu::Limits::default();
+        assert!(super::fits_limits(3840, 2160, &def));
+        // 16384×16384 planes are 384 MiB, over default max_storage_buffer_binding_size (128 MiB)
+        // and max_buffer_size (256 MiB).
+        assert!(!super::fits_limits(16384, 16384, &def));
+        let size = super::planes_len(64, 64);
+        assert!(super::fits_limits(64, 64, &wgpu::Limits { max_storage_buffer_binding_size: size, max_buffer_size: size, ..def.clone() }));
+        assert!(!super::fits_limits(64, 64, &wgpu::Limits { max_storage_buffer_binding_size: size - 1, max_buffer_size: size, ..def.clone() }));
+        assert!(!super::fits_limits(64, 64, &wgpu::Limits { max_storage_buffer_binding_size: size, max_buffer_size: size - 1, ..def.clone() }));
+
+        let Some(_) = crate::tests::gpu() else { return };
+        let instance = wgpu::Instance::new(wgpu::InstanceDescriptor::new_without_display_handle());
+        let adapter = pollster::block_on(instance.request_adapter(&Default::default())).expect("adapter");
+        let required_limits = wgpu::Limits { max_storage_buffer_binding_size: 4096, max_buffer_size: 4096, ..def };
+        let (device, queue) = pollster::block_on(adapter.request_device(&crate::context::device_descriptor(required_limits))).expect("limited device");
+        let g = crate::Gpu::new(&adapter, device, queue).expect("limited Gpu");
+        let yp = super::YuvPipe::new(&g.ctx.device).expect("yuv420 pipe");
+        let src = g.ctx.upload_image(&noise(64, 64, 1)).expect("upload");
+        assert!(super::convert(&mut crate::context::Enc::new(&g.ctx), &yp, &src, [0.0; 3]).is_none());
+        assert!(g.ctx.check_health().is_ok());
+    }
+
+    #[test]
+    fn unsupported_sizes_are_not_converted() {
+        let Some(g) = crate::tests::gpu() else { return };
+        let yp = super::YuvPipe::new(&g.ctx.device).expect("yuv420 pipe");
+        let src = g.ctx.upload_image(&noise(12, 4, 3)).expect("upload");
+        assert!(super::convert(&mut crate::context::Enc::new(&g.ctx), &yp, &src, [0.0; 3]).is_none());
+    }
+}
+
+#[cfg(test)]
+mod accel_tests {
+    use effectcraft_color::Label;
+    use effectcraft_project::{BitDepth, Comp, ItemKind};
+    use effectcraft_render::{Accelerator, Backend, RenderOpts, Renderer};
+    use effectcraft_time::{FrameRate, Tick};
+
+    use crate::tests::{Pattern, Scene, opts};
+
+    fn scene(w: u32, h: u32) -> Scene {
+        let mut s = Scene::new(BitDepth::Bpc8);
+        let comp = Comp::new(w, h, FrameRate::FPS_30, Tick::from_seconds_f64(2.0));
+        s.cid = s.p.add_item("Comp yuv", Label::Sandstone, None, ItemKind::Comp(comp.clone().into()));
+        s.comp = comp;
+        let l = s.footage(w + 7, h + 3);
+        s.push(l);
+        let sol = s.solid([0.9, 0.2, 0.4], w / 2, h / 3);
+        s.push(sol);
+        s
+    }
+
+    /// The accelerator's YUV frame is the export's CPU conversion of the very frame
+    /// `comp_frame` returns.
+    #[test]
+    fn comp_frame_yuv420_is_the_cpu_conversion_of_comp_frame() {
+        let Some(g) = crate::tests::gpu() else { return };
+        let s = scene(96, 60);
+        let mut r = Renderer::new(&s.p, &Pattern, RenderOpts { backend: Backend::Gpu, ..opts() });
+        r.accel = Some(g);
+        let bg = [0.2, 0.3, 0.4];
+        let rgba = g.comp_frame(&r, s.cid, Tick::ZERO).expect("rgba frame");
+        let yuv = g.comp_frame_yuv420(&r, s.cid, Tick::ZERO, bg).expect("yuv frame");
+        super::tests::assert_parity(g, &yuv, &super::tests::cpu(&rgba, bg), 0.006, "comp frame");
+    }
+
+    #[test]
+    fn odd_sized_comps_fall_back_to_the_cpu() {
+        let Some(g) = crate::tests::gpu() else { return };
+        let s = scene(97, 61);
+        let mut r = Renderer::new(&s.p, &Pattern, RenderOpts { backend: Backend::Gpu, ..opts() });
+        r.accel = Some(g);
+        assert!(g.comp_frame(&r, s.cid, Tick::ZERO).is_some());
+        assert!(g.comp_frame_yuv420(&r, s.cid, Tick::ZERO, [0.0; 3]).is_none());
+    }
+
+    #[test]
+    fn comp_frame_yuv420_falls_back_when_pipeline_init_failed() {
+        let Some(_) = crate::tests::gpu() else { return };
+        let g = crate::Gpu::try_headless().expect("headless Gpu");
+        let _ = g.ctx.yuv.set(Err("simulated yuv420 init failure".into()));
+        let s = scene(96, 60);
+        let mut r = Renderer::new(&s.p, &Pattern, RenderOpts { backend: Backend::Gpu, ..opts() });
+        r.accel = Some(&g);
+        assert!(g.comp_frame_yuv420(&r, s.cid, Tick::ZERO, [0.0; 3]).is_none());
+    }
+}
+
+#[cfg(test)]
+mod tie_tests {
+    use effectcraft_raster::Image;
+
+    fn lum(r: u8, g: u8, b: u8) -> f32 {
+        let (r, g, b) = (r as f32 / 255.0, g as f32 / 255.0, b as f32 / 255.0);
+        0.2126 * r + 0.7152 * g + 0.0722 * b
+    }
+
+    fn px(p: [u8; 3]) -> [f32; 4] {
+        [p[0] as f32 / 255.0, p[1] as f32 / 255.0, p[2] as f32 / 255.0, 1.0]
+    }
+
+    /// Opaque pixels whose Y (or whose 2×2 block's U or V) lands exactly on .5 in the CPU's f32
+    /// math: a kernel that rounds ties the other way moves most of them.
+    #[test]
+    fn rounding_ties_match_cpu() {
+        let mut ties: Vec<[u8; 3]> = vec![];
+        for r in 0..=255u8 {
+            for g in 0..=255u8 {
+                for b in 0..=255u8 {
+                    let x = 16.0 + 219.0 * lum(r, g, b);
+                    if x - x.floor() == 0.5 {
+                        ties.push([r, g, b]);
+                    }
+                }
+            }
+        }
+        assert!(!ties.is_empty());
+        let mut blocks: Vec<[[u8; 3]; 4]> = vec![];
+        let mut s = 12345u32;
+        let mut rnd = || {
+            s ^= s << 13;
+            s ^= s >> 17;
+            s ^= s << 5;
+            (s >> 24) as u8
+        };
+        // Bounded so the search stays quick in debug builds (a few hundred blocks).
+        for _ in 0..8_000_000 {
+            let blk = [[rnd(), rnd(), rnd()], [rnd(), rnd(), rnd()], [rnd(), rnd(), rnd()], [rnd(), rnd(), rnd()]];
+            let (mut a0, mut a1) = (0f32, 0f32);
+            for p in blk {
+                let l = lum(p[0], p[1], p[2]);
+                a0 += (p[2] as f32 / 255.0 - l) / 1.8556;
+                a1 += (p[0] as f32 / 255.0 - l) / 1.5748;
+            }
+            let u = 128.0 + 224.0 * a0 / 4.0;
+            let v = 128.0 + 224.0 * a1 / 4.0;
+            if u - u.floor() == 0.5 || v - v.floor() == 0.5 {
+                blocks.push(blk);
+            }
+        }
+        eprintln!("Y tie pixels: {}, chroma tie blocks: {}", ties.len(), blocks.len());
+        assert!(!blocks.is_empty());
+        let Some(g) = crate::tests::gpu() else { return };
+        let yp = super::YuvPipe::new(&g.ctx.device).expect("yuv420 pipe");
+        let w = 1024usize;
+        let h = (ties.len().div_ceil(w) + 1) & !1;
+        let mut img = Image::new(w as u32, h as u32);
+        for (i, p) in img.data.iter_mut().enumerate() {
+            *p = px(ties[i % ties.len()]);
+        }
+        let src = g.ctx.upload_image(&img).expect("upload");
+        let got = super::convert(&mut crate::context::Enc::new(&g.ctx), &yp, &src, [0.0; 3]).expect("readback");
+        super::tests::assert_parity(g, &got, &super::tests::cpu(&img, [0.0; 3]), 0.02, "Y ties");
+        let cw = 512usize;
+        let rows = blocks.len().div_ceil(cw);
+        let mut img = Image::new((cw * 2) as u32, (rows * 2) as u32);
+        for cy in 0..rows {
+            for cx in 0..cw {
+                let b = blocks[(cy * cw + cx) % blocks.len()];
+                for (k, p) in b.iter().enumerate() {
+                    let (x, y) = (cx * 2 + k % 2, cy * 2 + k / 2);
+                    img.data[y * cw * 2 + x] = px(*p);
+                }
+            }
+        }
+        let src = g.ctx.upload_image(&img).expect("upload");
+        let got = super::convert(&mut crate::context::Enc::new(&g.ctx), &yp, &src, [0.0; 3]).expect("readback");
+        super::tests::assert_parity(g, &got, &super::tests::cpu(&img, [0.0; 3]), 0.06, "chroma ties");
+    }
+}
diff --git a/crates/hevcenc/src/deblock.rs b/crates/hevcenc/src/deblock.rs
index 6f5d17b87..6d326e5d4 100644
--- a/crates/hevcenc/src/deblock.rs
+++ b/crates/hevcenc/src/deblock.rs
@@ -78,7 +78,6 @@ pub fn deblock(planes: &mut [Vec<u16>; 3], blk: &[Blk], w: usize, h: usize, qp:
 
 /// Filter one 4-sample luma edge segment. `o` = offset of q0 of the first line, `step` = distance
 /// between samples across the edge, `along` = distance between lines.
-#[allow(clippy::too_many_arguments)]
 fn filter_luma(s: &mut [u16], o: usize, step: usize, along: usize, tc: i32, beta: i32, bd: u32) {
     let px = |s: &[u16], k: usize, i: usize| s[o + k * along - (i + 1) * step] as i32;
     let qx = |s: &[u16], k: usize, i: usize| s[o + k * along + i * step] as i32;
diff --git a/crates/hevcenc/src/frame.rs b/crates/hevcenc/src/frame.rs
index 760bea2b0..ee141e3e7 100644
--- a/crates/hevcenc/src/frame.rs
+++ b/crates/hevcenc/src/frame.rs
@@ -7,7 +7,10 @@ use crate::inter::{self, PlaneRef};
 use crate::intra::{self, Refs};
 use crate::me::MeRef;
 use crate::params::{LOG2_CTB, LOG2_MAX_TB, LOG2_MIN_CB, MAX_MERGE_CAND};
-use crate::tables::*;
+use crate::tables::{
+    ABS_MVD_GT0, ABS_MVD_GT1, CBF_CHROMA, CBF_LUMA, CODED_SUB_BLOCK, CTX_IDX_MAP, CU_SKIP, GT1, GT2, INTRA_CHROMA, LAST_X_PREFIX, LAST_Y_PREFIX, MERGE_FLAG,
+    MERGE_IDX, MVP_FLAG, PART_MODE, PRED_MODE, PREV_INTRA_LUMA, RQT_ROOT_CBF, SCAN_4, SIG_COEFF, SPLIT_CU, qpc_420, scan_order,
+};
 use crate::transform;
 
 pub const F_INTRA: u8 = 1;
@@ -73,6 +76,40 @@ pub enum SliceKind {
     P,
 }
 
+/// Picture geometry and slice coding parameters shared by the CTU encoder.
+pub struct FrameConfig {
+    pub bit_depth: u32,
+    pub width: usize,
+    pub height: usize,
+    pub kind: SliceKind,
+    pub slice_qp: i32,
+}
+
+/// A square node in the coding or transform quadtree.
+#[derive(Clone, Copy)]
+struct TreeNode {
+    x: usize,
+    y: usize,
+    log2: u32,
+    depth: u32,
+}
+
+impl TreeNode {
+    fn children(self) -> impl Iterator<Item = Self> {
+        let h = 1usize << (self.log2 - 1);
+        [(0, 0), (h, 0), (0, h), (h, h)].into_iter().map(move |(dx, dy)| Self { x: self.x + dx, y: self.y + dy, log2: self.log2 - 1, depth: self.depth + 1 })
+    }
+}
+
+/// Transform syntax inherited from the parent node and the enclosing CU.
+#[derive(Clone, Copy)]
+struct TransformState {
+    blk_idx: u32,
+    parent: [bool; 2],
+    intra: bool,
+    nxn: bool,
+}
+
 pub struct FrameCoder<'a> {
     pub bd: u32,
     pub w: usize,
@@ -114,17 +151,8 @@ fn morton(x: u32, y: u32) -> u32 {
 const COARSE_MODES: [u32; 11] = [0, 1, 2, 6, 10, 14, 18, 22, 26, 30, 34];
 
 impl<'a> FrameCoder<'a> {
-    #[allow(clippy::too_many_arguments)]
-    pub fn new(
-        bd: u32,
-        w: usize,
-        h: usize,
-        kind: SliceKind,
-        slice_qp: i32,
-        src: &'a [Vec<u16>; 3],
-        refp: Option<&'a [Vec<u16>; 3]>,
-        me: Option<&'a MeRef>,
-    ) -> Self {
+    pub fn new(config: FrameConfig, src: &'a [Vec<u16>; 3], refp: Option<&'a [Vec<u16>; 3]>, me: Option<&'a MeRef>) -> Self {
+        let FrameConfig { bit_depth: bd, width: w, height: h, kind, slice_qp } = config;
         let off = 6 * (bd as i32 - 8);
         let qpi = slice_qp.clamp(-off, 57);
         let qp_c = qpc_420(qpi) + off;
@@ -256,7 +284,7 @@ impl<'a> FrameCoder<'a> {
             let mut decs = Vec::with_capacity(64);
             self.decide(x, y, LOG2_CTB, 0, &mut est, &mut decs);
             let mut idx = 0;
-            self.write_cq(enc, x, y, LOG2_CTB, 0, &decs, &mut idx);
+            self.write_cq(enc, TreeNode { x, y, log2: LOG2_CTB, depth: 0 }, &decs, &mut idx);
             debug_assert_eq!(idx, decs.len());
             debug_assert_eq!(est.ctx, enc.ctx);
             enc.terminate((i + 1 == total) as u32); // end_of_slice_segment_flag
@@ -276,7 +304,8 @@ impl<'a> FrameCoder<'a> {
     }
 
     /// Final pass: re-code the decided quadtree with the real arithmetic coder.
-    fn write_cq(&mut self, enc: &mut CabacEncoder, x: usize, y: usize, log2: u32, depth: u32, decs: &[CuDec], idx: &mut usize) {
+    fn write_cq(&mut self, enc: &mut CabacEncoder, node: TreeNode, decs: &[CuDec], idx: &mut usize) {
+        let TreeNode { x, y, log2, depth } = node;
         if x >= self.w || y >= self.h {
             return;
         }
@@ -294,9 +323,8 @@ impl<'a> FrameCoder<'a> {
             let (eff, _) = self.encode_cu(enc, x, y, log2, depth, d.mode);
             debug_assert_eq!(eff, d.mode);
         } else {
-            let h = n / 2;
-            for (dx, dy) in [(0, 0), (h, 0), (0, h), (h, h)] {
-                self.write_cq(enc, x + dx, y + dy, log2 - 1, depth + 1, decs, idx);
+            for child in node.children() {
+                self.write_cq(enc, child, decs, idx);
             }
         }
     }
@@ -447,7 +475,7 @@ impl<'a> FrameCoder<'a> {
                 self.write_intra_modes(s, x, y, n, nxn, &modes);
                 s.decision(INTRA_CHROMA, 0); // intra_chroma_pred_mode 4 (DM)
                 let mut ti = 0;
-                self.write_tt(s, x, y, x, y, log2, 0, 0, [true, true], true, nxn, &mut ti);
+                self.write_tt(s, TreeNode { x, y, log2, depth: 0 }, TransformState { blk_idx: 0, parent: [true, true], intra: true, nxn }, &mut ti);
                 (mode, self.cu_dist(x, y, n))
             }
             _ => {
@@ -490,7 +518,12 @@ impl<'a> FrameCoder<'a> {
                         s.decision(MERGE_FLAG, 1);
                         write_merge_idx(s, idx as usize);
                         let mut ti = 0;
-                        self.write_tt(s, x, y, x, y, log2, 0, 0, [true, true], false, false, &mut ti);
+                        self.write_tt(
+                            s,
+                            TreeNode { x, y, log2, depth: 0 },
+                            TransformState { blk_idx: 0, parent: [true, true], intra: false, nxn: false },
+                            &mut ti,
+                        );
                     }
                     CuMode::Amvp { mv, mvp } => {
                         s.decision(CU_SKIP + skip_ctx, 0);
@@ -503,7 +536,12 @@ impl<'a> FrameCoder<'a> {
                         s.decision(RQT_ROOT_CBF, root as u32);
                         if root {
                             let mut ti = 0;
-                            self.write_tt(s, x, y, x, y, log2, 0, 0, [true, true], false, false, &mut ti);
+                            self.write_tt(
+                                s,
+                                TreeNode { x, y, log2, depth: 0 },
+                                TransformState { blk_idx: 0, parent: [true, true], intra: false, nxn: false },
+                                &mut ti,
+                            );
                         }
                     }
                     // Handled by the arm above.
@@ -715,22 +753,9 @@ impl<'a> FrameCoder<'a> {
 
     /// transform_tree() (7.3.8.8) over the coded transform blocks of the CU; no split flag is ever
     /// coded (max_transform_hierarchy_depth_* = 0), splits are inferred.
-    #[allow(clippy::too_many_arguments)]
-    fn write_tt<S: Sink>(
-        &self,
-        s: &mut S,
-        x0: usize,
-        y0: usize,
-        xb: usize,
-        yb: usize,
-        log2: u32,
-        depth: u32,
-        blk_idx: u32,
-        parent: [bool; 2],
-        intra: bool,
-        nxn: bool,
-        ti: &mut usize,
-    ) {
+    fn write_tt<S: Sink>(&self, s: &mut S, node: TreeNode, state: TransformState, ti: &mut usize) {
+        let TreeNode { x: x0, y: y0, log2, depth } = node;
+        let TransformState { blk_idx, parent, intra, nxn } = state;
         let n = 1usize << log2;
         let split = log2 > LOG2_MAX_TB || (nxn && depth == 0);
         let mut cbf_c = [false; 2];
@@ -745,13 +770,11 @@ impl<'a> FrameCoder<'a> {
             cbf_c = parent;
         }
         if split {
-            let h = n / 2;
-            for (i, (dx, dy)) in [(0, 0), (h, 0), (0, h), (h, h)].into_iter().enumerate() {
-                self.write_tt(s, x0 + dx, y0 + dy, x0, y0, log2 - 1, depth + 1, i as u32, cbf_c, intra, nxn, ti);
+            for (i, child) in node.children().enumerate() {
+                self.write_tt(s, child, TransformState { blk_idx: i as u32, parent: cbf_c, ..state }, ti);
             }
             return;
         }
-        let _ = (xb, yb);
         let tb = self.tbs[*ti];
         *ti += 1;
         debug_assert_eq!(tb.c, 0);
@@ -874,9 +897,9 @@ impl<'a> FrameCoder<'a> {
             let (px, py, pn, pw, ph) = if c == 0 { (x, y, n, self.w, self.h) } else { (x / 2, y / 2, n / 2, self.cw, self.ch) };
             let pr = PlaneRef { data: &refp[c], w: pw, h: ph };
             if c == 0 {
-                inter::mc_luma(pr, self.bd, px as i32, py as i32, mv, pn, pn, &mut self.pred);
+                inter::mc_luma(pr, self.bd, px as i32, py as i32, mv, (pn, pn), &mut self.pred);
             } else {
-                inter::mc_chroma(pr, self.bd, px as i32, py as i32, mv, pn, pn, &mut self.pred);
+                inter::mc_chroma(pr, self.bd, px as i32, py as i32, mv, (pn, pn), &mut self.pred);
             }
             inter::put_uni(&self.pred, pn, pn, self.bd, &mut self.rec[c][py * pw + px..], pw);
         }
@@ -1153,8 +1176,119 @@ fn last_prefix(v: u32) -> (u32, u32, u32) {
     }
 }
 
+/// Context increment for significant_coeff_flag (H.265 9.3.4.2).
+fn significance_context(group: (usize, usize), pos: (usize, usize), log2: u32, prev_csbf: u8, c: usize, scan_idx: usize) -> usize {
+    let (xs, ys) = group;
+    let (xp, yp) = pos;
+    let (xc, yc) = (xs * 4 + xp, ys * 4 + yp);
+    if log2 == 2 {
+        CTX_IDX_MAP[(yc << 2) + xc] as usize
+    } else if xc + yc == 0 {
+        0
+    } else {
+        let mut sc = match prev_csbf {
+            0 => {
+                if xp + yp == 0 {
+                    2
+                } else if xp + yp < 3 {
+                    1
+                } else {
+                    0
+                }
+            }
+            1 => {
+                if yp == 0 {
+                    2
+                } else if yp == 1 {
+                    1
+                } else {
+                    0
+                }
+            }
+            2 => {
+                if xp == 0 {
+                    2
+                } else if xp == 1 {
+                    1
+                } else {
+                    0
+                }
+            }
+            _ => 2,
+        };
+        if c == 0 {
+            if xs + ys > 0 {
+                sc += 3;
+            }
+            sc += if log2 == 3 { if scan_idx == 0 { 9 } else { 15 } } else { 21 };
+        } else {
+            sc += if log2 == 3 { 9 } else { 12 };
+        }
+        sc
+    }
+}
+
+/// Absolute levels, signs and Rice remainders for one significant coefficient group.
+fn write_coefficient_levels<S: Sink>(s: &mut S, sig: &[u8], at: impl Fn(usize) -> i32, i: usize, c: usize, prev_g1: &mut Option<u32>) {
+    let nsig = sig.len();
+    let abs_at = |k: usize| at(sig[k] as usize).unsigned_abs();
+    let mut ctx_set = if i == 0 || c > 0 { 0 } else { 2 };
+    if *prev_g1 == Some(0) {
+        ctx_set += 1;
+    }
+    let mut g1ctx = 1u32;
+    let mut gt1 = [0u8; 16];
+    let mut first_g1: Option<usize> = None;
+    let c_off_g1 = if c > 0 { 16 } else { 0 };
+    for k in 0..nsig.min(8) {
+        let f = abs_at(k) > 1;
+        s.decision(GT1 + ctx_set * 4 + g1ctx.min(3) as usize + c_off_g1, f as u32);
+        gt1[k] = f as u8;
+        if f {
+            g1ctx = 0;
+            if first_g1.is_none() {
+                first_g1 = Some(k);
+            }
+        } else if g1ctx > 0 {
+            g1ctx += 1;
+        }
+    }
+    *prev_g1 = Some(g1ctx);
+    let mut gt2 = 0u32;
+    if let Some(k) = first_g1 {
+        gt2 = (abs_at(k) > 2) as u32;
+        s.decision(GT2 + ctx_set + if c > 0 { 4 } else { 0 }, gt2);
+    }
+    // sign data hiding: the sign of the first coefficient in scan order (sig[nsig - 1]) is
+    // inferred from the parity of the sum of absolute levels
+    let hidden = sig[0] as i32 - sig[nsig - 1] as i32 > 3;
+    let nsigns = if hidden { nsig - 1 } else { nsig };
+    for k in 0..nsigns {
+        s.bypass((at(sig[k] as usize) < 0) as u32);
+    }
+    if hidden {
+        let sum: u32 = (0..nsig).map(abs_at).sum();
+        debug_assert_eq!(at(sig[nsig - 1] as usize) < 0, sum & 1 == 1, "sign hiding parity");
+    }
+    let mut rice = 0u32;
+    for k in 0..nsig {
+        let mut base = 1 + gt1[k] as u32;
+        if Some(k) == first_g1 {
+            base += gt2;
+        }
+        let thresh = if k < 8 { if Some(k) == first_g1 { 3 } else { 2 } } else { 1 };
+        if base == thresh {
+            let level = abs_at(k);
+            write_remaining(s, level - base, rice);
+            if level > 3 * (1 << rice) {
+                rice = (rice + 1).min(4);
+            }
+        }
+    }
+}
+
 /// residual_coding() (7.3.8.11) of one transform block of levels (row-major, n x n). No transform
-/// skip, no sign data hiding.
+/// skip; signs use sign data hiding where the coefficient span permits it.
 fn residual_coding<S: Sink>(s: &mut S, lv: &[i32], log2: u32, c: usize, scan_idx: usize) {
     let n = 1usize << log2;
     let log2sb = log2 - 2;
@@ -1233,51 +1367,7 @@ fn residual_coding<S: Sink>(s: &mut S, lv: &[i32], log2: u32, c: usize, scan_idx
             let (xc, yc) = (xs * 4 + xp, ys * 4 + yp);
             let v = lv[yc * n + xc] != 0;
             if np > 0 || !infer_dc {
-                let sig_ctx = if log2 == 2 {
-                    CTX_IDX_MAP[(yc << 2) + xc] as usize
-                } else if xc + yc == 0 {
-                    0
-                } else {
-                    let mut sc = match prev_csbf {
-                        0 => {
-                            if xp + yp == 0 {
-                                2
-                            } else if xp + yp < 3 {
-                                1
-                            } else {
-                                0
-                            }
-                        }
-                        1 => {
-                            if yp == 0 {
-                                2
-                            } else if yp == 1 {
-                                1
-                            } else {
-                                0
-                            }
-                        }
-                        2 => {
-                            if xp == 0 {
-                                2
-                            } else if xp == 1 {
-                                1
-                            } else {
-                                0
-                            }
-                        }
-                        _ => 2,
-                    };
-                    if c == 0 {
-                        if xs + ys > 0 {
-                            sc += 3;
-                        }
-                        sc += if log2 == 3 { if scan_idx == 0 { 9 } else { 15 } } else { 21 };
-                    } else {
-                        sc += if log2 == 3 { 9 } else { 12 };
-                    }
-                    sc
-                };
+                let sig_ctx = significance_context((xs, ys), (xp, yp), log2, prev_csbf, c, scan_idx);
                 s.decision(SIG_COEFF + c_off_sig + sig_ctx, v as u32);
                 if v {
                     sig[nsig] = p as u8;
@@ -1294,60 +1384,7 @@ fn residual_coding<S: Sink>(s: &mut S, lv: &[i32], log2: u32, c: usize, scan_idx
         if nsig == 0 {
             continue;
         }
-        let abs_at = |k: usize| at(xs, ys, sig[k] as usize).unsigned_abs();
-        let mut ctx_set = if i == 0 || c > 0 { 0 } else { 2 };
-        if prev_g1 == Some(0) {
-            ctx_set += 1;
-        }
-        let mut g1ctx = 1u32;
-        let mut gt1 = [0u8; 16];
-        let mut first_g1: Option<usize> = None;
-        let c_off_g1 = if c > 0 { 16 } else { 0 };
-        for k in 0..nsig.min(8) {
-            let f = abs_at(k) > 1;
-            s.decision(GT1 + ctx_set * 4 + g1ctx.min(3) as usize + c_off_g1, f as u32);
-            gt1[k] = f as u8;
-            if f {
-                g1ctx = 0;
-                if first_g1.is_none() {
-                    first_g1 = Some(k);
-                }
-            } else if g1ctx > 0 {
-                g1ctx += 1;
-            }
-        }
-        prev_g1 = Some(g1ctx);
-        let mut gt2 = 0u32;
-        if let Some(k) = first_g1 {
-            gt2 = (abs_at(k) > 2) as u32;
-            s.decision(GT2 + ctx_set + if c > 0 { 4 } else { 0 }, gt2);
-        }
-        // sign data hiding: the sign of the first coefficient in scan order (sig[nsig - 1]) is
-        // inferred from the parity of the sum of absolute levels
-        let hidden = sig[0] as i32 - sig[nsig - 1] as i32 > 3;
-        let nsigns = if hidden { nsig - 1 } else { nsig };
-        for k in 0..nsigns {
-            s.bypass((at(xs, ys, sig[k] as usize) < 0) as u32);
-        }
-        if hidden {
-            let sum: u32 = (0..nsig).map(abs_at).sum();
-            debug_assert_eq!(at(xs, ys, sig[nsig - 1] as usize) < 0, sum & 1 == 1, "sign hiding parity");
-        }
-        let mut rice = 0u32;
-        for k in 0..nsig {
-            let mut base = 1 + gt1[k] as u32;
-            if Some(k) == first_g1 {
-                base += gt2;
-            }
-            let thresh = if k < 8 { if Some(k) == first_g1 { 3 } else { 2 } } else { 1 };
-            if base == thresh {
-                let level = abs_at(k);
-                write_remaining(s, level - base, rice);
-                if level > 3 * (1 << rice) {
-                    rice = (rice + 1).min(4);
-                }
-            }
-        }
+        write_coefficient_levels(s, &sig[..nsig], |p| at(xs, ys, p), i, c, &mut prev_g1);
     }
 }
 
diff --git a/crates/hevcenc/src/inter.rs b/crates/hevcenc/src/inter.rs
index e363871b5..03bf50ffb 100644
--- a/crates/hevcenc/src/inter.rs
+++ b/crates/hevcenc/src/inter.rs
@@ -35,7 +35,8 @@ impl PlaneRef<'_> {
 
 /// Luma prediction samples (14-bit intermediate) of a w x h block at (x, y) displaced by the
 /// quarter-sample vector `mv`, into `out` (stride w).
-pub fn mc_luma(f: PlaneRef, bd: u32, x: i32, y: i32, mv: [i16; 2], w: usize, h: usize, out: &mut [i16]) {
+pub fn mc_luma(f: PlaneRef, bd: u32, x: i32, y: i32, mv: [i16; 2], size: (usize, usize), out: &mut [i16]) {
+    let (w, h) = size;
     let (fx, fy) = ((mv[0] & 3) as usize, (mv[1] & 3) as usize);
     let xi = x + (mv[0] as i32 >> 2);
     let yi = y + (mv[1] as i32 >> 2);
@@ -89,7 +90,8 @@ pub fn mc_luma(f: PlaneRef, bd: u32, x: i32, y: i32, mv: [i16; 2], w: usize, h:
 }
 
 /// Chroma prediction samples of a w x h block at chroma position (x, y) with a 1/8-sample vector.
-pub fn mc_chroma(f: PlaneRef, bd: u32, x: i32, y: i32, mv: [i16; 2], w: usize, h: usize, out: &mut [i16]) {
+pub fn mc_chroma(f: PlaneRef, bd: u32, x: i32, y: i32, mv: [i16; 2], size: (usize, usize), out: &mut [i16]) {
+    let (w, h) = size;
     let (fx, fy) = ((mv[0] & 7) as usize, (mv[1] & 7) as usize);
     let xi = x + (mv[0] as i32 >> 3);
     let yi = y + (mv[1] as i32 >> 3);
diff --git a/crates/hevcenc/src/lib.rs b/crates/hevcenc/src/lib.rs
index b2e86b6a1..4d38f84d9 100644
--- a/crates/hevcenc/src/lib.rs
+++ b/crates/hevcenc/src/lib.rs
@@ -15,8 +15,6 @@
 //! ```
 
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
-// Index loops over fixed-size blocks read more clearly than iterator chains in codec code.
-#![allow(clippy::needless_range_loop, clippy::too_many_arguments)]
 
 mod bitstream;
 mod cabac;
@@ -311,7 +309,7 @@ impl Encoder {
         let kind = if idr { SliceKind::I } else { SliceKind::P };
         let me = if idr { None } else { self.reference.as_ref().map(|r| me::MeRef::new(&r[0], w, h, bd)) };
         let refp = if idr { None } else { self.reference.as_ref() };
-        let mut fc = FrameCoder::new(bd, w, h, kind, qp, &src, refp, me.as_ref());
+        let mut fc = FrameCoder::new(frame::FrameConfig { bit_depth: bd, width: w, height: h, kind, slice_qp: qp }, &src, refp, me.as_ref());
 
         // slice_segment_header() (7.3.6.1)
         let mut bw = BitWriter::new();
diff --git a/crates/host/src/lib.rs b/crates/host/src/lib.rs
index 577492a53..08e1616a7 100644
--- a/crates/host/src/lib.rs
+++ b/crates/host/src/lib.rs
@@ -106,552 +106,4 @@ pub fn config_dir() -> Option<std::path::PathBuf> {
 }
 
 #[cfg(test)]
-mod tests {
-    use serde_json::json;
-
-    #[test]
-    fn host_runs_tasks_scheduled_by_panel_handlers() {
-        let mut s = super::session();
-        let result = s.execute("script.run", json!({"code": "var w=new Window('palette','Timer regression'); var b=w.add('button',undefined,'Import'); b.onClick=function(){app.scheduleTask(\"app.project.items.addComp('Scheduled',64,64,1,1,25)\",0,false);};w.show();"})).unwrap();
-        assert_eq!(result["ok"], true, "{result}");
-        s.execute("scriptui.click", json!({"window":"Timer regression","widget":"Import"})).unwrap();
-        assert!(s.project.items.is_empty());
-        let tick = s.execute("script.runTasks", json!({})).unwrap();
-        assert_eq!(tick["ran"], 1, "{tick}");
-        assert_eq!(tick["errors"], json!([]), "{tick}");
-        assert!(s.project.items.values().any(|item| item.name == "Scheduled"));
-        s.execute("scriptui.close", json!({"window":"Timer regression"})).unwrap();
-    }
-
-    /// Layer ▸ Camera ▸ Link Focus Distance to Point of Interest / to Layer: the expressions
-    /// evaluate to the camera's focus on the target.
-    #[test]
-    fn focus_link_expressions_track_the_target() {
-        use effectcraft_engine::geom::vec3;
-        let mut s = super::session();
-        s.execute("comp.new", json!({"name": "F", "width": 400, "height": 300, "duration": 2})).unwrap();
-        let t = s.execute("layer.newSolid", json!({"color": "#ffffff", "width": 50, "height": 50})).unwrap()["layer"].as_u64().unwrap();
-        s.execute("layer.setSwitch", json!({"layers": [t], "switch": "threeD", "value": true})).unwrap();
-        s.execute("layer.setTransform", json!({"layer": t, "prop": "position", "value": [260, 120, 400]})).unwrap();
-        let cam = s.execute("layer.newCamera", json!({})).unwrap()["layer"].as_u64().unwrap();
-        let cid = s.active_comp_id().unwrap();
-        let focus = |s: &effectcraft_engine::Session| {
-            let comp = s.project.comp(cid).unwrap();
-            let mut ctx = effectcraft_engine::render::EvalCtx::new(&s.project, cid, comp, s.time());
-            ctx.expr = s.expr.as_deref();
-            let l = comp.layer(effectcraft_engine::project::LayerId(cam)).unwrap();
-            ctx.value(l, l.props.prop("cameraOptions/focusDistance").unwrap()).as_f64()
-        };
-        let depth = |s: &effectcraft_engine::Session| {
-            let comp = s.project.comp(cid).unwrap();
-            let ctx = effectcraft_engine::render::EvalCtx::new(&s.project, cid, comp, s.time());
-            let c = comp.layer(effectcraft_engine::project::LayerId(cam)).unwrap();
-            let tl = comp.layer(effectcraft_engine::project::LayerId(t)).unwrap();
-            let cs = effectcraft_engine::render::three_d::camera::layer_camera(&ctx, c);
-            cs.depth(ctx.world_matrix(tl).apply(vec3(25.0, 25.0, 0.0)))
-        };
-        s.execute("layer.select", json!({"layers": [cam, t]})).unwrap();
-        let set = s.execute("camera.setFocusToLayer", json!({})).unwrap()["focusDistance"].as_f64().unwrap();
-        assert!((set - depth(&s)).abs() < 1e-6 && (focus(&s) - set).abs() < 1e-6);
-        s.execute("camera.linkFocusToLayer", json!({})).unwrap();
-        // Move the target: the linked focus follows.
-        s.execute("layer.setTransform", json!({"layer": t, "prop": "position", "value": [200, 150, 900]})).unwrap();
-        assert!((focus(&s) - depth(&s)).abs() < 1e-3, "{} vs {}", focus(&s), depth(&s));
-        s.execute("camera.linkFocusToPoi", json!({"camera": cam})).unwrap();
-        let poi = {
-            let l = s.active_comp().unwrap().layer(effectcraft_engine::project::LayerId(cam)).unwrap();
-            let p = l.props.prop("transform/position").unwrap().value.as_vec3();
-            let q = l.props.prop("transform/poi").unwrap().value.as_vec3();
-            ((p[0] - q[0]).powi(2) + (p[1] - q[1]).powi(2) + (p[2] - q[2]).powi(2)).sqrt()
-        };
-        assert!((focus(&s) - poi).abs() < 1e-6, "{} vs {poi}", focus(&s));
-    }
-
-    #[test]
-    fn wired_session_renders_demo_with_expressions() {
-        let mut s = super::session();
-        s.execute("file.openDemoProject", json!({})).unwrap();
-        let cid = s.active_comp_id().unwrap();
-        let lid = s.active_comp().unwrap().layers[1].id.0;
-        s.execute("prop.setExpression", json!({"layer": lid, "path": "transform/rotation", "expression": "time * 90"})).unwrap();
-        let img = s.render(cid, s.time(), effectcraft_engine::render::RenderOpts { scale: 0.25, ..Default::default() });
-        assert!(img.data.iter().any(|p| p[3] > 0.5));
-    }
-
-    /// File ▸ Import of glTF/GLB/OBJ models through the media layer, placed as model layers and
-    /// drawn by the Advanced 3D renderer.
-    #[test]
-    fn imported_models_render_in_advanced_3d() {
-        let fx = |n: &str| format!("{}/../model/tests/fixtures/{n}", env!("CARGO_MANIFEST_DIR"));
-        let mut s = super::session();
-        s.execute("comp.new", json!({"name": "M", "width": 160, "height": 120, "renderer": "advanced3d"})).unwrap();
-        let r = s.execute("file.import", json!({"paths": [fx("cube.obj"), fx("quad.glb"), fx("quad.gltf")]})).unwrap();
-        assert_eq!(r["errors"], json!([]), "{r}");
-        let items: Vec<u64> = r["items"].as_array().unwrap().iter().map(|v| v.as_u64().unwrap()).collect();
-        assert_eq!(items.len(), 3);
-        let cube = s.execute("layer.addItem", json!({"item": items[0]})).unwrap()["layer"].as_u64().unwrap();
-        s.execute("prop.set", json!({"layer": cube, "path": "transform/rotationY", "value": 30})).unwrap();
-        s.execute("prop.set", json!({"layer": cube, "path": "transform/rotationX", "value": 20})).unwrap();
-        let cid = s.active_comp_id().unwrap();
-        let opts = effectcraft_engine::render::RenderOpts::default();
-        let img = s.render(cid, s.time(), opts);
-        let covered = img.data.iter().filter(|p| p[3] > 0.99).count();
-        assert!(covered > 1000, "the cube covers part of the frame: {covered}");
-        // Red faces (material Red) are visible.
-        assert!(img.data.iter().any(|p| p[3] > 0.99 && p[0] > 0.5 && p[1] < 0.2));
-        // The textured binary glTF quad.
-        for _ in 0..3 {
-            s.execute("edit.undo", json!({})).unwrap();
-        }
-        s.execute("layer.addItem", json!({"item": items[1]})).unwrap();
-        let img = s.render(cid, s.time(), opts);
-        assert!(img.data.iter().filter(|p| p[3] > 0.99).count() > 1000);
-        // Classic 3D doesn't draw models.
-        s.execute("comp.renderer", json!({"renderer": "classic3d"})).unwrap();
-        assert!(s.render(cid, s.time(), opts).data.iter().all(|p| p[3] == 0.0));
-    }
-
-    /// A binary glTF of a red cube 2 units wide (positions and indices only).
-    fn glb_cube() -> Vec<u8> {
-        let mut bin: Vec<u8> = (0..8u32).flat_map(|i| [i & 1, (i >> 1) & 1, (i >> 2) & 1].map(|b| b as f32 * 2.0 - 1.0)).flat_map(f32::to_le_bytes).collect();
-        let faces: [[u16; 4]; 6] = [[0, 2, 3, 1], [4, 5, 7, 6], [0, 1, 5, 4], [2, 6, 7, 3], [0, 4, 6, 2], [1, 3, 7, 5]];
-        bin.extend(faces.iter().flat_map(|f| [f[0], f[1], f[2], f[0], f[2], f[3]]).flat_map(u16::to_le_bytes));
-        let gltf = json!({
-            "asset": {"version": "2.0"},
-            "scene": 0,
-            "scenes": [{"nodes": [0]}],
-            "nodes": [{"mesh": 0}],
-            "meshes": [{"primitives": [{"attributes": {"POSITION": 0}, "indices": 1, "material": 0}]}],
-            "materials": [{"pbrMetallicRoughness": {"baseColorFactor": [1, 0, 0, 1], "metallicFactor": 0, "roughnessFactor": 1}}],
-            "buffers": [{"byteLength": bin.len()}],
-            "bufferViews": [{"buffer": 0, "byteOffset": 0, "byteLength": 96}, {"buffer": 0, "byteOffset": 96, "byteLength": 72}],
-            "accessors": [
-                {"bufferView": 0, "componentType": 5126, "count": 8, "type": "VEC3", "min": [-1, -1, -1], "max": [1, 1, 1]},
-                {"bufferView": 1, "componentType": 5123, "count": 36, "type": "SCALAR"}
-            ]
-        });
-        let mut text = gltf.to_string().into_bytes();
-        text.resize(text.len().div_ceil(4) * 4, b' ');
-        let chunk = |kind: &[u8; 4], data: &[u8]| [&(data.len() as u32).to_le_bytes()[..], kind, data].concat();
-        let body = [chunk(b"JSON", &text), chunk(b"BIN\0", &bin)].concat();
-        [&b"glTF"[..], &2u32.to_le_bytes(), &(12 + body.len() as u32).to_le_bytes(), &body].concat()
-    }
-
-    /// #264: a model imported into a new composition (Classic 3D by default) was invisible on
-    /// every renderer, because only Advanced 3D draws models. Adding it now switches the comp,
-    /// and the software renderer (no GPU, as on the reporter's Intel HD Graphics 5500) draws it.
-    #[test]
-    fn imported_glb_shows_in_a_new_composition() {
-        let path = std::env::temp_dir().join(format!("effectcraft-264-cube-{}.glb", std::process::id()));
-        std::fs::write(&path, glb_cube()).unwrap();
-        let mut s = super::session();
-        assert!(s.accel.is_none(), "renders in software");
-        let r = s.execute("file.import", json!({"paths": [path.to_string_lossy()]})).unwrap();
-        assert_eq!(r["errors"], json!([]), "{r}");
-        s.state.project_selection = vec![effectcraft_project::ItemId(r["items"][0].as_u64().unwrap())];
-        s.execute("file.newCompFromSelection", json!({})).unwrap();
-        let comp = s.active_comp().unwrap();
-        assert_eq!(comp.renderer, effectcraft_project::Renderer::Advanced3D);
-        let layer = comp.layers[0].id.0;
-        s.execute("prop.set", json!({"layer": layer, "path": "transform/rotationY", "value": 30})).unwrap();
-        s.execute("prop.set", json!({"layer": layer, "path": "transform/rotationX", "value": 20})).unwrap();
-        let cid = s.active_comp_id().unwrap();
-        let img = s.render(cid, s.time(), effectcraft_engine::render::RenderOpts { scale: 0.25, ..Default::default() });
-        let red = img.data.iter().filter(|p| p[3] > 0.99 && p[0] > 0.2 && p[1] < 0.05 && p[2] < 0.05).count();
-        let _ = std::fs::remove_file(&path);
-        // Half the comp height wide, seen at an angle: well over 5% of the frame.
-        assert!(red * 20 > img.data.len(), "red cube pixels: {red} of {}", img.data.len());
-    }
-
-    /// #651: an animated GIF imported from disk plays: the layer shows each frame at its time,
-    /// in the viewer's renders and in exports alike.
-    #[test]
-    fn an_imported_animated_gif_plays() {
-        let dir = std::env::temp_dir().join(format!("ec-gif-{}", std::process::id()));
-        std::fs::create_dir_all(&dir).unwrap();
-        let path = dir.join("anim.gif");
-        let mut bytes = Vec::new();
-        {
-            let mut enc = gif::Encoder::new(&mut bytes, 4, 4, &[]).unwrap();
-            for rgb in [[255u8, 0, 0], [0, 255, 0], [0, 0, 255]] {
-                let mut f = gif::Frame::from_rgb(4, 4, &rgb.repeat(16));
-                f.delay = 10;
-                enc.write_frame(&f).unwrap();
-            }
-        }
-        std::fs::write(&path, bytes).unwrap();
-        let mut s = super::session();
-        s.execute("comp.new", json!({"name": "G", "width": 4, "height": 4, "frameRate": 30, "duration": 1})).unwrap();
-        s.execute("file.import", json!({"paths": [path.to_string_lossy()], "addToComp": true})).unwrap();
-        let cid = s.active_comp_id().unwrap();
-        let rgb = |t: f64| {
-            let img = s.render(cid, effectcraft_time::Tick::from_seconds_f64(t), effectcraft_engine::render::RenderOpts::default());
-            let p = img.data[5];
-            [p[0].round(), p[1].round(), p[2].round()]
-        };
-        assert_eq!(rgb(0.05), [1.0, 0.0, 0.0]);
-        assert_eq!(rgb(0.15), [0.0, 1.0, 0.0]);
-        assert_eq!(rgb(0.25), [0.0, 0.0, 1.0]);
-        let _ = std::fs::remove_dir_all(dir);
-    }
-
-    /// The web app's path: outputs go to a sink (downloads), never to the file system.
-    #[test]
-    fn render_queue_exports_to_a_sink() {
-        use std::sync::{Arc, Mutex};
-        let got: Arc<Mutex<Vec<(String, Vec<u8>)>>> = Arc::default();
-        let g = got.clone();
-        let mut s = super::session();
-        s.exporter = Some(Arc::new(super::FileExporter { sink: Some(Arc::new(move |p: &str, d: Vec<u8>| g.lock().unwrap().push((p.to_string(), d)))) }));
-        s.execute("file.openDemoProject", json!({})).unwrap();
-        // Rooted without a drive letter is not absolute on Windows, where the engine joins it to the home drive.
-        let dir = if cfg!(windows) { "C:/no-such-dir-effectcraft-sink-test" } else { "/no-such-dir-effectcraft-sink-test" };
-        s.execute(
-            "renderQueue.add",
-            json!({"format": "gif", "output": format!("{dir}/a.gif"), "resolution": 0.0625, "timeSpan": "custom", "start": 0.0, "end": 0.2}),
-        )
-        .unwrap();
-        s.execute(
-            "renderQueue.add",
-            json!({"format": "png", "output": format!("{dir}/seq_[##].png"), "resolution": 0.0625, "timeSpan": "custom", "start": 0.0, "end": 0.1}),
-        )
-        .unwrap();
-        s.execute("renderQueue.render", json!({"wait": true})).unwrap();
-        s.poll_render();
-        let mut got = got.lock().unwrap().clone();
-        got.sort_by(|a, b| a.0.cmp(&b.0));
-        let names: Vec<std::path::PathBuf> = got.iter().map(|(p, _)| std::path::PathBuf::from(p)).collect();
-        let expected = [format!("{dir}/a.gif"), format!("{dir}/seq_00.png"), format!("{dir}/seq_01.png"), format!("{dir}/seq_02.png")]
-            .map(|p| std::path::absolute(p).unwrap());
-        assert_eq!(names, expected);
-        assert!(got[0].1.starts_with(b"GIF89a"));
-        assert!(got[1].1.starts_with(b"\x89PNG"));
-        assert!(!std::path::Path::new(dir).exists());
-    }
-
-    #[test]
-    fn render_queue_exports_demo_comp() {
-        let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/host-rq");
-        let _ = std::fs::remove_dir_all(&dir);
-        let mut s = super::session();
-        s.execute("file.openDemoProject", json!({})).unwrap();
-        let out = dir.join("[compName]_[width]x[height].[fileExtension]");
-        let r = s
-            .execute(
-                "renderQueue.add",
-                json!({"format": "h264", "output": out.to_string_lossy(), "resolution": 0.125, "timeSpan": "custom", "start": 0.0, "end": 0.4}),
-            )
-            .unwrap();
-        let path = r["outputPath"].as_str().unwrap().to_string();
-        assert!(path.ends_with("_240x134.mp4"), "{path}");
-        // A second item: PNG sequence, rendered in the background.
-        s.execute("renderQueue.add", json!({"format": "png", "output": dir.join("seq_[###].png").to_string_lossy(), "resolution": 0.0625, "timeSpan": "custom", "start": 0.0, "end": 0.2})).unwrap();
-        let r = s.execute("renderQueue.render", json!({"wait": false})).unwrap();
-        assert_eq!(r["items"].as_array().unwrap().len(), 2);
-        let t0 = std::time::Instant::now();
-        while s.is_rendering() {
-            assert!(t0.elapsed().as_secs() < 300, "render timed out");
-            std::thread::sleep(std::time::Duration::from_millis(20));
-            s.poll_render();
-        }
-        s.poll_render();
-        let list = s.execute("renderQueue.list", json!({})).unwrap();
-        for it in list["items"].as_array().unwrap() {
-            assert_eq!(it["statusLabel"], "Done", "{it}");
-            assert!(it["render_time"].as_f64().is_some());
-            assert!(std::path::Path::new(it["last_output"].as_str().unwrap()).exists(), "{it}");
-        }
-        assert!(std::path::Path::new(&path).metadata().unwrap().len() > 500);
-        assert!(dir.join("seq_000.png").exists() && dir.join("seq_005.png").exists() && !dir.join("seq_006.png").exists());
-        // Rendering again needs a re-queue.
-        assert!(s.execute("renderQueue.render", json!({})).is_err());
-        s.execute("renderQueue.setRender", json!({"index": 1, "render": true})).unwrap();
-        assert_eq!(s.project.render_queue[0].status, effectcraft_engine::project::render_queue::RenderStatus::Queued);
-    }
-
-    /// Value of a property of layer `l` at time 0 (keys + expression).
-    fn value(s: &effectcraft_engine::Session, l: u64, path: &str) -> effectcraft_engine::keyframe::Value {
-        let cid = s.active_comp_id().unwrap();
-        let comp = s.project.comp(cid).unwrap();
-        let layer = comp.layer(effectcraft_engine::project::LayerId(l)).unwrap();
-        let ctx =
-            effectcraft_engine::render::EvalCtx { project: &s.project, comp_id: cid, comp, time: Default::default(), expr: s.expr.as_deref(), footage: None };
-        ctx.value(layer, layer.props.prop(path).unwrap())
-    }
-
-    #[test]
-    fn pick_whip_expressions_evaluate() {
-        let mut s = super::session();
-        s.execute("comp.new", json!({"name": "C", "width": 200, "height": 200, "frameRate": 30, "duration": 2})).unwrap();
-        let a = s.execute("layer.newSolid", json!({"color": "#ffffff"})).unwrap()["layer"].as_u64().unwrap();
-        let b = s.execute("layer.newSolid", json!({"name": "Src", "color": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
-        s.execute("prop.set", json!({"layer": b, "path": "transform/rotation", "value": 33})).unwrap();
-        s.execute("prop.set", json!({"layer": b, "path": "transform/position", "value": [12, 34]})).unwrap();
-        s.execute("effect.apply", json!({"layer": b, "effect": "Gaussian Blur"})).unwrap();
-        s.execute("prop.set", json!({"layer": b, "path": "effects/#1/blurriness", "value": 21})).unwrap();
-        s.execute("layer.addMask", json!({"layer": b})).unwrap();
-        s.execute("prop.set", json!({"layer": b, "path": "masks/#1/feather", "value": [7, 7]})).unwrap();
-        let link = |s: &mut effectcraft_engine::Session, from: &str, to: &str| {
-            s.execute("prop.pickWhip", json!({"layer": a, "path": from, "target": {"layer": b, "path": to}})).unwrap();
-        };
-        link(&mut s, "transform/opacity", "transform/rotation");
-        assert_eq!(value(&s, a, "transform/opacity").as_f64(), 33.0);
-        link(&mut s, "transform/scale", "transform/rotation");
-        let cid = s.active_comp_id().unwrap();
-        let ep = effectcraft_expr::eval_property(&s.project, cid, effectcraft_engine::project::LayerId(a), "transform/scale", 0.0);
-        assert!(ep.is_ok(), "{ep:?}");
-        assert_eq!(value(&s, a, "transform/scale").as_vec2(), [33.0, 33.0]);
-        link(&mut s, "transform/position", "transform/position");
-        assert_eq!(value(&s, a, "transform/position").as_vec2(), [12.0, 34.0]);
-        link(&mut s, "transform/rotation", "effects/#1/blurriness");
-        assert_eq!(value(&s, a, "transform/rotation").as_f64(), 21.0);
-        link(&mut s, "transform/opacity", "masks/#1/feather");
-        assert_eq!(value(&s, a, "transform/opacity").as_f64(), 7.0);
-        // Separated dimensions: X Position reference.
-        s.execute("prop.separateDimensions", json!({"layer": b})).unwrap();
-        link(&mut s, "transform/rotation", "transform/positionX");
-        assert_eq!(value(&s, a, "transform/rotation").as_f64(), 12.0);
-    }
-
-    /// The expression error bar's list: evaluation errors and syntax errors, with the layer and
-    /// property they belong to.
-    #[test]
-    fn expression_errors_are_collected() {
-        let mut s = super::session();
-        s.execute("comp.new", json!({"name": "C", "width": 100, "height": 100, "frameRate": 30, "duration": 2})).unwrap();
-        let a = s.execute("layer.newSolid", json!({"name": "Box", "color": "#ffffff"})).unwrap()["layer"].as_u64().unwrap();
-        s.execute("prop.setExpression", json!({"layer": a, "path": "transform/opacity", "expression": "50"})).unwrap();
-        assert_eq!(s.execute("expr.errors", json!({})).unwrap()["count"], 0);
-        s.execute("prop.setExpression", json!({"layer": a, "path": "transform/rotation", "expression": "thisComp.layer(\"Nope\").rotation"})).unwrap();
-        s.execute("prop.setExpression", json!({"layer": a, "path": "transform/opacity", "expression": "1 +* ("})).unwrap();
-        let r = s.execute("expr.errors", json!({})).unwrap();
-        assert_eq!(r["count"], 2, "{r}");
-        let errs = r["errors"].as_array().unwrap();
-        let rot = errs.iter().find(|e| e["path"] == "transform/rotation").unwrap();
-        assert!(rot["message"].as_str().unwrap().contains("Nope"), "{rot}");
-        assert_eq!(rot["layerIndex"], 1);
-        assert_eq!(rot["layerName"], "Box");
-        assert_eq!(rot["disabled"], false);
-        let op = errs.iter().find(|e| e["path"] == "transform/opacity").unwrap();
-        assert_eq!(op["disabled"], true);
-        assert!(r["text"][0].as_str().unwrap().contains("of layer 1 ('Box') in comp 'C'"), "{r}");
-        // A user-disabled (but valid) expression is not an error.
-        s.execute("prop.setExpression", json!({"layer": a, "path": "transform/rotation", "expression": "45"})).unwrap();
-        s.execute("prop.setExpression", json!({"layer": a, "path": "transform/rotation", "enabled": false})).unwrap();
-        assert_eq!(s.execute("expr.errors", json!({})).unwrap()["count"], 1);
-        // The Expression Language menu is categorised.
-        let m = s.execute("expr.languageMenu", json!({})).unwrap();
-        assert!(m.as_array().unwrap().iter().any(|c| c["category"] == "Footage" && c["items"].as_array().unwrap().iter().any(|i| i["text"] == "sourceData")));
-    }
-
-    /// File ▸ Import of JSON/CSV data files as data footage, read by expressions.
-    #[test]
-    fn imported_data_files_drive_expressions() {
-        let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/host-data");
-        let _ = std::fs::remove_dir_all(&dir);
-        std::fs::create_dir_all(&dir).unwrap();
-        std::fs::write(dir.join("levels.csv"), "label,value\nlow,10\nhigh,90\n").unwrap();
-        std::fs::write(dir.join("cfg.json"), r#"{"angle": 33}"#).unwrap();
-        std::fs::write(dir.join("broken.json"), "{nope").unwrap();
-        let mut s = super::session();
-        s.execute("comp.new", json!({"name": "C", "width": 100, "height": 100, "frameRate": 30, "duration": 2})).unwrap();
-        let paths: Vec<String> = ["levels.csv", "cfg.json", "broken.json"].iter().map(|n| dir.join(n).to_string_lossy().to_string()).collect();
-        let r = s.execute("file.import", json!({"paths": paths})).unwrap();
-        assert_eq!(r["items"].as_array().unwrap().len(), 2, "{r}");
-        assert_eq!(r["errors"].as_array().unwrap().len(), 1, "{r}");
-        let csv = r["items"][0].as_u64().unwrap();
-        assert_eq!(s.project.item(effectcraft_engine::project::ItemId(csv)).unwrap().type_name(), "Data");
-        assert!(s.execute("layer.addItem", json!({"item": csv})).is_err(), "data files are not layers");
-        let a = s.execute("layer.newSolid", json!({"color": "#ffffff"})).unwrap()["layer"].as_u64().unwrap();
-        s.execute("prop.setExpression", json!({"layer": a, "path": "transform/opacity", "expression": "footage(\"levels.csv\").sourceData[1].value"})).unwrap();
-        s.execute("prop.setExpression", json!({"layer": a, "path": "transform/rotation", "expression": "footage(\"cfg.json\").sourceData.angle"})).unwrap();
-        assert_eq!(value(&s, a, "transform/opacity").as_f64(), 90.0);
-        assert_eq!(value(&s, a, "transform/rotation").as_f64(), 33.0);
-    }
-
-    /// sampleImage through the renderer: a box's Fill colour follows the solid under it.
-    #[test]
-    fn sample_image_drives_a_colour() {
-        let mut s = super::session();
-        s.execute("comp.new", json!({"name": "C", "width": 100, "height": 100, "frameRate": 30, "duration": 2})).unwrap();
-        s.execute("layer.newSolid", json!({"name": "Bg", "color": "#00ff00"})).unwrap();
-        let a = s.execute("layer.newSolid", json!({"name": "Fg", "color": "#ffffff", "width": 20, "height": 20})).unwrap()["layer"].as_u64().unwrap();
-        s.execute("effect.apply", json!({"layer": a, "effect": "Fill"})).unwrap();
-        s.execute(
-            "prop.setExpression",
-            json!({"layer": a, "path": "effects/#1/color", "expression": "thisComp.layer(\"Bg\").sampleImage(thisComp.layer(\"Bg\").fromComp(toComp(anchorPoint)))"}),
-        )
-        .unwrap();
-        let cid = s.active_comp_id().unwrap();
-        let img = s.render(cid, s.time(), effectcraft_engine::render::RenderOpts::default());
-        let px = img.get(50, 50);
-        assert!(px[1] > 0.99 && px[0] < 0.01, "the box is filled with the sampled green: {px:?}");
-    }
-
-    /// Proxies through the real media and export layers: Render Settings ▸ Proxy Use decides
-    /// whether an export uses the proxy, and Create Proxy renders and attaches one.
-    #[test]
-    fn proxies_in_exports_and_create_proxy() {
-        let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/host-proxy");
-        let _ = std::fs::remove_dir_all(&dir);
-        std::fs::create_dir_all(&dir).unwrap();
-        let p = |n: &str| dir.join(n).to_string_lossy().to_string();
-        let mut s = super::session();
-        // Source and proxy stills, written by the app itself.
-        s.execute("comp.new", json!({"name": "Red", "width": 16, "height": 16, "frameRate": 10, "duration": 1})).unwrap();
-        let red = s.active_comp_id().unwrap();
-        s.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap();
-        s.execute("comp.saveFrameAs", json!({"path": p("red.png")})).unwrap();
-        s.execute("comp.new", json!({"name": "Blue", "width": 8, "height": 8, "frameRate": 10, "duration": 1})).unwrap();
-        s.execute("layer.newSolid", json!({"color": "#0000ff"})).unwrap();
-        s.execute("comp.saveFrameAs", json!({"path": p("blue.png")})).unwrap();
-        let foot = s.execute("file.import", json!({"paths": [p("red.png")]})).unwrap()["items"][0].as_u64().unwrap();
-        s.execute("file.setProxy", json!({"item": foot, "path": p("blue.png")})).unwrap();
-        s.execute("comp.new", json!({"name": "Out", "width": 16, "height": 16, "frameRate": 10, "duration": 1})).unwrap();
-        let out = s.active_comp_id().unwrap();
-        s.execute("layer.addItem", json!({"item": foot})).unwrap();
-        // Export one frame with each Proxy Use.
-        for (name, using) in [("all", "use_all_[#].png"), ("none", "use_none_[#].png")] {
-            s.execute(
-                "renderQueue.add",
-                json!({"comp": out.0, "format": "png", "output": p(using), "timeSpan": "custom", "start": 0.0, "end": 0.1, "proxyUse": name}),
-            )
-            .unwrap();
-        }
-        s.execute("renderQueue.render", json!({"wait": true})).unwrap();
-        s.poll_render();
-        let centre = |s: &mut effectcraft_engine::Session, path: &str| {
-            let id = s.execute("file.import", json!({"paths": [path]})).unwrap()["items"][0].as_u64().unwrap();
-            s.execute("comp.new", json!({"name": "Probe", "width": 16, "height": 16, "frameRate": 10, "duration": 1})).unwrap();
-            s.execute("layer.addItem", json!({"item": id})).unwrap();
-            let c = s.active_comp_id().unwrap();
-            s.render(c, Default::default(), Default::default()).get(8, 8)
-        };
-        let all = centre(&mut s, &p("use_all_0.png"));
-        assert!(all[2] > 0.99 && all[0] < 0.01, "Use All Proxies renders the blue proxy: {all:?}");
-        let none = centre(&mut s, &p("use_none_0.png"));
-        assert!(none[0] > 0.99 && none[2] < 0.01, "Use No Proxies renders the red source: {none:?}");
-        // Create Proxy ▸ Still: rendered at half size and attached to the comp.
-        s.execute("file.createProxy", json!({"kind": "still", "comp": red.0, "path": p("red_proxy_[#####].png")})).unwrap();
-        s.execute("renderQueue.render", json!({"wait": true})).unwrap();
-        s.poll_render();
-        let px = s.project.item(red).unwrap().proxy.clone().expect("Create Proxy attached the rendered still");
-        assert!(px.enabled);
-        assert_eq!((px.footage.width, px.footage.height), (8, 8));
-        assert!(std::path::Path::new(&px.footage.path).exists(), "{}", px.footage.path);
-    }
-
-    /// A script builds a comp, queues it and renders it through the Render Queue.
-    #[test]
-    fn script_renders_through_the_render_queue() {
-        let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/host-script");
-        let _ = std::fs::remove_dir_all(&dir);
-        let out = dir.join("scripted.gif");
-        let mut s = super::session();
-        let code = format!(
-            r#"
-            var comp = app.project.items.addComp("Scripted", 64, 48, 1, 0.2, 10);
-            var sq = comp.layers.addSolid([1, 0.5, 0], "Square", 16, 16, 1);
-            sq.transform.position.setValueAtTime(0, [8, 24]);
-            sq.transform.position.setValueAtTime(0.1, [56, 24]);
-            var item = app.project.renderQueue.items.add(comp);
-            item.outputModule(1).applyTemplate("GIF");
-            item.outputModule(1).file = new File({});
-            app.project.renderQueue.render();
-            [item.status == RQItemStatus.DONE, item.outputModule(1).file.fsName, app.project.renderQueue.numItems]
-            "#,
-            serde_json::to_string(&out.to_string_lossy()).unwrap()
-        );
-        let r = s.execute("script.run", json!({"code": code})).unwrap();
-        assert_eq!(r["ok"], json!(true), "{r}");
-        assert_eq!(r["result"][0], json!(true), "{r}");
-        assert_eq!(r["result"][2], json!(1));
-        let bytes = std::fs::read(&out).unwrap();
-        assert!(bytes.starts_with(b"GIF89a"));
-    }
-
-    /// importFile, layers.add(footage) and project save/open from a script.
-    #[test]
-    fn script_imports_footage_and_saves() {
-        let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/host-script-import");
-        let _ = std::fs::remove_dir_all(&dir);
-        std::fs::create_dir_all(&dir).unwrap();
-        let q = |n: &str| serde_json::to_string(&dir.join(n).to_string_lossy()).unwrap();
-        let mut s = super::session();
-        let code = format!(
-            r#"
-            var c = app.project.items.addComp("Src", 32, 32, 1, 1, 10);
-            c.layers.addSolid([0, 1, 0], "G", 32, 32, 1);
-            app.run("comp.saveFrameAs", {{comp: c.id, path: {png}}});
-            var still = app.project.importFile(new ImportOptions(new File({png})));
-            var main = app.project.items.addComp("Main", 64, 64, 1, 1, 10);
-            var l = main.layers.add(still);
-            app.project.save(new File({proj}));
-            [still instanceof FootageItem, still.width, still.mainSource.isStill, l.source.name, app.project.file.name]
-            "#,
-            png = q("frame.png"),
-            proj = q("p.ecproj")
-        );
-        let r = s.execute("script.run", json!({"code": code})).unwrap();
-        assert_eq!(r["ok"], json!(true), "{r}");
-        assert_eq!(r["result"], json!([true, 32, true, "frame.png", "p.ecproj"]), "{r}");
-        let r = s.execute("script.run", json!({"code": format!("app.open(new File({})); app.project.numItems", q("p.ecproj"))})).unwrap();
-        assert_eq!(r["result"], json!(5), "{r}"); // Src, Solids, G, frame.png, Main
-    }
-
-    #[test]
-    fn expression_syntax_errors_disable_the_expression() {
-        let mut s = super::session();
-        s.execute("comp.new", json!({"name": "C", "width": 100, "height": 100, "frameRate": 30, "duration": 2})).unwrap();
-        let a = s.execute("layer.newSolid", json!({"color": "#ffffff"})).unwrap()["layer"].as_u64().unwrap();
-        let r = s.execute("prop.setExpression", json!({"layer": a, "path": "transform/opacity", "expression": "1 +* ("})).unwrap();
-        assert!(r["error"].is_string(), "{r}");
-        let pr = s.active_comp().unwrap().layers[0].props.prop("transform/opacity").unwrap().clone();
-        assert!(!pr.expr.unwrap().enabled);
-        assert_eq!(value(&s, a, "transform/opacity").as_f64(), 100.0);
-        s.execute("prop.setExpression", json!({"layer": a, "path": "transform/opacity", "expression": "50"})).unwrap();
-        assert_eq!(value(&s, a, "transform/opacity").as_f64(), 50.0);
-    }
-    /// Create Stereo 3D Rig: the eye cameras' expressions follow the master camera and the
-    /// Stereo 3D Controls (and agree with the values the command wrote).
-    #[test]
-    fn stereo_rig_expressions_follow_the_master_camera() {
-        let mut s = super::session();
-        s.execute("comp.new", json!({"name": "Shot", "width": 640, "height": 360, "frameRate": 30, "duration": 2})).unwrap();
-        let src = s.active_comp_id().unwrap();
-        let cam = s.execute("layer.newCamera", json!({"name": "Main", "position": [320, 180, -800], "poi": [320, 180, 0], "zoom": 900})).unwrap()["layer"]
-            .as_u64()
-            .unwrap();
-        let r = s.execute("camera.stereoRig", json!({"sceneDepth": 4})).unwrap();
-        let ctl = r["controls"].as_u64().unwrap();
-        let left = effectcraft_engine::project::ItemId(r["leftComp"].as_u64().unwrap());
-        // The left eye camera's evaluated value (expressions on).
-        let v3 = |s: &effectcraft_engine::Session, path: &str| {
-            let comp = s.project.comp(left).unwrap();
-            let layer = &comp.layers[0];
-            let ctx = effectcraft_engine::render::EvalCtx {
-                project: &s.project,
-                comp_id: left,
-                comp,
-                time: Default::default(),
-                expr: s.expr.as_deref(),
-                footage: None,
-            };
-            ctx.value(layer, layer.props.prop(path).unwrap()).as_vec3()
-        };
-        let close = |a: [f64; 3], b: [f64; 3]| (0..3).all(|i| (a[i] - b[i]).abs() < 1e-6);
-        let d = 0.04 * 640.0;
-        assert!(close(v3(&s, "transform/position"), [320.0 - d / 2.0, 180.0, -800.0]), "{:?}", v3(&s, "transform/position"));
-        assert!(close(v3(&s, "transform/poi"), [320.0 - d / 2.0, 180.0, 0.0]), "{:?}", v3(&s, "transform/poi"));
-        // Moving the master moves the eyes.
-        s.execute("comp.open", json!({"comp": src.0})).unwrap();
-        s.execute("prop.set", json!({"layer": cam, "path": "transform/position", "value": [300, 180, -800]})).unwrap();
-        s.execute("prop.set", json!({"layer": cam, "path": "transform/poi", "value": [300, 180, 0]})).unwrap();
-        assert!(close(v3(&s, "transform/position"), [300.0 - d / 2.0, 180.0, -800.0]), "{:?}", v3(&s, "transform/position"));
-        // Controls: Center & Left puts the left eye a full separation left; convergence toes in.
-        s.execute("prop.set", json!({"layer": ctl, "path": "effects/#1/configuration", "value": 2})).unwrap();
-        s.execute("prop.set", json!({"layer": ctl, "path": "effects/#1/convergence", "value": true})).unwrap();
-        assert!(close(v3(&s, "transform/position"), [300.0 - d, 180.0, -800.0]), "{:?}", v3(&s, "transform/position"));
-        assert!(close(v3(&s, "transform/poi"), [300.0, 180.0, 0.0]), "{:?}", v3(&s, "transform/poi"));
-    }
-}
+mod tests;
diff --git a/crates/host/src/tests.rs b/crates/host/src/tests.rs
new file mode 100644
index 000000000..a73f15937
--- /dev/null
+++ b/crates/host/src/tests.rs
@@ -0,0 +1,544 @@
+use serde_json::json;
+
+#[test]
+fn host_runs_tasks_scheduled_by_panel_handlers() {
+    let mut s = super::session();
+    let result = s.execute("script.run", json!({"code": "var w=new Window('palette','Timer regression'); var b=w.add('button',undefined,'Import'); b.onClick=function(){app.scheduleTask(\"app.project.items.addComp('Scheduled',64,64,1,1,25)\",0,false);};w.show();"})).unwrap();
+    assert_eq!(result["ok"], true, "{result}");
+    s.execute("scriptui.click", json!({"window":"Timer regression","widget":"Import"})).unwrap();
+    assert!(s.project.items.is_empty());
+    let tick = s.execute("script.runTasks", json!({})).unwrap();
+    assert_eq!(tick["ran"], 1, "{tick}");
+    assert_eq!(tick["errors"], json!([]), "{tick}");
+    assert!(s.project.items.values().any(|item| item.name == "Scheduled"));
+    s.execute("scriptui.close", json!({"window":"Timer regression"})).unwrap();
+}
+
+/// Layer ▸ Camera ▸ Link Focus Distance to Point of Interest / to Layer: the expressions
+/// evaluate to the camera's focus on the target.
+#[test]
+fn focus_link_expressions_track_the_target() {
+    use effectcraft_engine::geom::vec3;
+    let mut s = super::session();
+    s.execute("comp.new", json!({"name": "F", "width": 400, "height": 300, "duration": 2})).unwrap();
+    let t = s.execute("layer.newSolid", json!({"color": "#ffffff", "width": 50, "height": 50})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("layer.setSwitch", json!({"layers": [t], "switch": "threeD", "value": true})).unwrap();
+    s.execute("layer.setTransform", json!({"layer": t, "prop": "position", "value": [260, 120, 400]})).unwrap();
+    let cam = s.execute("layer.newCamera", json!({})).unwrap()["layer"].as_u64().unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let focus = |s: &effectcraft_engine::Session| {
+        let comp = s.project.comp(cid).unwrap();
+        let mut ctx = effectcraft_engine::render::EvalCtx::new(&s.project, cid, comp, s.time());
+        ctx.expr = s.expr.as_deref();
+        let l = comp.layer(effectcraft_engine::project::LayerId(cam)).unwrap();
+        ctx.value(l, l.props.prop("cameraOptions/focusDistance").unwrap()).as_f64()
+    };
+    let depth = |s: &effectcraft_engine::Session| {
+        let comp = s.project.comp(cid).unwrap();
+        let ctx = effectcraft_engine::render::EvalCtx::new(&s.project, cid, comp, s.time());
+        let c = comp.layer(effectcraft_engine::project::LayerId(cam)).unwrap();
+        let tl = comp.layer(effectcraft_engine::project::LayerId(t)).unwrap();
+        let cs = effectcraft_engine::render::three_d::camera::layer_camera(&ctx, c);
+        cs.depth(ctx.world_matrix(tl).apply(vec3(25.0, 25.0, 0.0)))
+    };
+    s.execute("layer.select", json!({"layers": [cam, t]})).unwrap();
+    let set = s.execute("camera.setFocusToLayer", json!({})).unwrap()["focusDistance"].as_f64().unwrap();
+    assert!((set - depth(&s)).abs() < 1e-6 && (focus(&s) - set).abs() < 1e-6);
+    s.execute("camera.linkFocusToLayer", json!({})).unwrap();
+    // Move the target: the linked focus follows.
+    s.execute("layer.setTransform", json!({"layer": t, "prop": "position", "value": [200, 150, 900]})).unwrap();
+    assert!((focus(&s) - depth(&s)).abs() < 1e-3, "{} vs {}", focus(&s), depth(&s));
+    s.execute("camera.linkFocusToPoi", json!({"camera": cam})).unwrap();
+    let poi = {
+        let l = s.active_comp().unwrap().layer(effectcraft_engine::project::LayerId(cam)).unwrap();
+        let p = l.props.prop("transform/position").unwrap().value.as_vec3();
+        let q = l.props.prop("transform/poi").unwrap().value.as_vec3();
+        ((p[0] - q[0]).powi(2) + (p[1] - q[1]).powi(2) + (p[2] - q[2]).powi(2)).sqrt()
+    };
+    assert!((focus(&s) - poi).abs() < 1e-6, "{} vs {poi}", focus(&s));
+}
+
+#[test]
+fn wired_session_renders_demo_with_expressions() {
+    let mut s = super::session();
+    s.execute("file.openDemoProject", json!({})).unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let lid = s.active_comp().unwrap().layers[1].id.0;
+    s.execute("prop.setExpression", json!({"layer": lid, "path": "transform/rotation", "expression": "time * 90"})).unwrap();
+    let img = s.render(cid, s.time(), effectcraft_engine::render::RenderOpts { scale: 0.25, ..Default::default() });
+    assert!(img.data.iter().any(|p| p[3] > 0.5));
+}
+
+/// File ▸ Import of glTF/GLB/OBJ models through the media layer, placed as model layers and
+/// drawn by the Advanced 3D renderer.
+#[test]
+fn imported_models_render_in_advanced_3d() {
+    let fx = |n: &str| format!("{}/../model/tests/fixtures/{n}", env!("CARGO_MANIFEST_DIR"));
+    let mut s = super::session();
+    s.execute("comp.new", json!({"name": "M", "width": 160, "height": 120, "renderer": "advanced3d"})).unwrap();
+    let r = s.execute("file.import", json!({"paths": [fx("cube.obj"), fx("quad.glb"), fx("quad.gltf")]})).unwrap();
+    assert_eq!(r["errors"], json!([]), "{r}");
+    let items: Vec<u64> = r["items"].as_array().unwrap().iter().map(|v| v.as_u64().unwrap()).collect();
+    assert_eq!(items.len(), 3);
+    let cube = s.execute("layer.addItem", json!({"item": items[0]})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("prop.set", json!({"layer": cube, "path": "transform/rotationY", "value": 30})).unwrap();
+    s.execute("prop.set", json!({"layer": cube, "path": "transform/rotationX", "value": 20})).unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let opts = effectcraft_engine::render::RenderOpts::default();
+    let img = s.render(cid, s.time(), opts);
+    let covered = img.data.iter().filter(|p| p[3] > 0.99).count();
+    assert!(covered > 1000, "the cube covers part of the frame: {covered}");
+    // Red faces (material Red) are visible.
+    assert!(img.data.iter().any(|p| p[3] > 0.99 && p[0] > 0.5 && p[1] < 0.2));
+    // The textured binary glTF quad.
+    for _ in 0..3 {
+        s.execute("edit.undo", json!({})).unwrap();
+    }
+    s.execute("layer.addItem", json!({"item": items[1]})).unwrap();
+    let img = s.render(cid, s.time(), opts);
+    assert!(img.data.iter().filter(|p| p[3] > 0.99).count() > 1000);
+    // Classic 3D doesn't draw models.
+    s.execute("comp.renderer", json!({"renderer": "classic3d"})).unwrap();
+    assert!(s.render(cid, s.time(), opts).data.iter().all(|p| p[3] == 0.0));
+}
+
+/// A binary glTF of a red cube 2 units wide (positions and indices only).
+fn glb_cube() -> Vec<u8> {
+    let mut bin: Vec<u8> = (0..8u32).flat_map(|i| [i & 1, (i >> 1) & 1, (i >> 2) & 1].map(|b| b as f32 * 2.0 - 1.0)).flat_map(f32::to_le_bytes).collect();
+    let faces: [[u16; 4]; 6] = [[0, 2, 3, 1], [4, 5, 7, 6], [0, 1, 5, 4], [2, 6, 7, 3], [0, 4, 6, 2], [1, 3, 7, 5]];
+    bin.extend(faces.iter().flat_map(|f| [f[0], f[1], f[2], f[0], f[2], f[3]]).flat_map(u16::to_le_bytes));
+    let gltf = json!({
+        "asset": {"version": "2.0"},
+        "scene": 0,
+        "scenes": [{"nodes": [0]}],
+        "nodes": [{"mesh": 0}],
+        "meshes": [{"primitives": [{"attributes": {"POSITION": 0}, "indices": 1, "material": 0}]}],
+        "materials": [{"pbrMetallicRoughness": {"baseColorFactor": [1, 0, 0, 1], "metallicFactor": 0, "roughnessFactor": 1}}],
+        "buffers": [{"byteLength": bin.len()}],
+        "bufferViews": [{"buffer": 0, "byteOffset": 0, "byteLength": 96}, {"buffer": 0, "byteOffset": 96, "byteLength": 72}],
+        "accessors": [
+            {"bufferView": 0, "componentType": 5126, "count": 8, "type": "VEC3", "min": [-1, -1, -1], "max": [1, 1, 1]},
+            {"bufferView": 1, "componentType": 5123, "count": 36, "type": "SCALAR"}
+        ]
+    });
+    let mut text = gltf.to_string().into_bytes();
+    text.resize(text.len().div_ceil(4) * 4, b' ');
+    let chunk = |kind: &[u8; 4], data: &[u8]| [&(data.len() as u32).to_le_bytes()[..], kind, data].concat();
+    let body = [chunk(b"JSON", &text), chunk(b"BIN\0", &bin)].concat();
+    [&b"glTF"[..], &2u32.to_le_bytes(), &(12 + body.len() as u32).to_le_bytes(), &body].concat()
+}
+
+/// #264: a model imported into a new composition (Classic 3D by default) was invisible on
+/// every renderer, because only Advanced 3D draws models. Adding it now switches the comp,
+/// and the software renderer (no GPU, as on the reporter's Intel HD Graphics 5500) draws it.
+#[test]
+fn imported_glb_shows_in_a_new_composition() {
+    let path = std::env::temp_dir().join(format!("effectcraft-264-cube-{}.glb", std::process::id()));
+    std::fs::write(&path, glb_cube()).unwrap();
+    let mut s = super::session();
+    assert!(s.accel.is_none(), "renders in software");
+    let r = s.execute("file.import", json!({"paths": [path.to_string_lossy()]})).unwrap();
+    assert_eq!(r["errors"], json!([]), "{r}");
+    s.state.project_selection = vec![effectcraft_project::ItemId(r["items"][0].as_u64().unwrap())];
+    s.execute("file.newCompFromSelection", json!({})).unwrap();
+    let comp = s.active_comp().unwrap();
+    assert_eq!(comp.renderer, effectcraft_project::Renderer::Advanced3D);
+    let layer = comp.layers[0].id.0;
+    s.execute("prop.set", json!({"layer": layer, "path": "transform/rotationY", "value": 30})).unwrap();
+    s.execute("prop.set", json!({"layer": layer, "path": "transform/rotationX", "value": 20})).unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let img = s.render(cid, s.time(), effectcraft_engine::render::RenderOpts { scale: 0.25, ..Default::default() });
+    let red = img.data.iter().filter(|p| p[3] > 0.99 && p[0] > 0.2 && p[1] < 0.05 && p[2] < 0.05).count();
+    let _ = std::fs::remove_file(&path);
+    // Half the comp height wide, seen at an angle: well over 5% of the frame.
+    assert!(red * 20 > img.data.len(), "red cube pixels: {red} of {}", img.data.len());
+}
+
+/// #651: an animated GIF imported from disk plays: the layer shows each frame at its time,
+/// in the viewer's renders and in exports alike.
+#[test]
+fn an_imported_animated_gif_plays() {
+    let dir = std::env::temp_dir().join(format!("ec-gif-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("anim.gif");
+    let mut bytes = Vec::new();
+    {
+        let mut enc = gif::Encoder::new(&mut bytes, 4, 4, &[]).unwrap();
+        for rgb in [[255u8, 0, 0], [0, 255, 0], [0, 0, 255]] {
+            let mut f = gif::Frame::from_rgb(4, 4, &rgb.repeat(16));
+            f.delay = 10;
+            enc.write_frame(&f).unwrap();
+        }
+    }
+    std::fs::write(&path, bytes).unwrap();
+    let mut s = super::session();
+    s.execute("comp.new", json!({"name": "G", "width": 4, "height": 4, "frameRate": 30, "duration": 1})).unwrap();
+    s.execute("file.import", json!({"paths": [path.to_string_lossy()], "addToComp": true})).unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let rgb = |t: f64| {
+        let img = s.render(cid, effectcraft_time::Tick::from_seconds_f64(t), effectcraft_engine::render::RenderOpts::default());
+        let p = img.data[5];
+        [p[0].round(), p[1].round(), p[2].round()]
+    };
+    assert_eq!(rgb(0.05), [1.0, 0.0, 0.0]);
+    assert_eq!(rgb(0.15), [0.0, 1.0, 0.0]);
+    assert_eq!(rgb(0.25), [0.0, 0.0, 1.0]);
+    let _ = std::fs::remove_dir_all(dir);
+}
+
+/// The web app's path: outputs go to a sink (downloads), never to the file system.
+#[test]
+fn render_queue_exports_to_a_sink() {
+    use std::sync::{Arc, Mutex};
+    let got: Arc<Mutex<Vec<(String, Vec<u8>)>>> = Arc::default();
+    let g = got.clone();
+    let mut s = super::session();
+    s.exporter = Some(Arc::new(super::FileExporter { sink: Some(Arc::new(move |p: &str, d: Vec<u8>| g.lock().unwrap().push((p.to_string(), d)))) }));
+    s.execute("file.openDemoProject", json!({})).unwrap();
+    // Rooted without a drive letter is not absolute on Windows, where the engine joins it to the home drive.
+    let dir = if cfg!(windows) { "C:/no-such-dir-effectcraft-sink-test" } else { "/no-such-dir-effectcraft-sink-test" };
+    s.execute(
+        "renderQueue.add",
+        json!({"format": "gif", "output": format!("{dir}/a.gif"), "resolution": 0.0625, "timeSpan": "custom", "start": 0.0, "end": 0.2}),
+    )
+    .unwrap();
+    s.execute(
+        "renderQueue.add",
+        json!({"format": "png", "output": format!("{dir}/seq_[##].png"), "resolution": 0.0625, "timeSpan": "custom", "start": 0.0, "end": 0.1}),
+    )
+    .unwrap();
+    s.execute("renderQueue.render", json!({"wait": true})).unwrap();
+    s.poll_render();
+    let mut got = got.lock().unwrap().clone();
+    got.sort_by(|a, b| a.0.cmp(&b.0));
+    let names: Vec<std::path::PathBuf> = got.iter().map(|(p, _)| std::path::PathBuf::from(p)).collect();
+    let expected = [format!("{dir}/a.gif"), format!("{dir}/seq_00.png"), format!("{dir}/seq_01.png"), format!("{dir}/seq_02.png")]
+        .map(|p| std::path::absolute(p).unwrap());
+    assert_eq!(names, expected);
+    assert!(got[0].1.starts_with(b"GIF89a"));
+    assert!(got[1].1.starts_with(b"\x89PNG"));
+    assert!(!std::path::Path::new(dir).exists());
+}
+
+#[test]
+fn render_queue_exports_demo_comp() {
+    let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/host-rq");
+    let _ = std::fs::remove_dir_all(&dir);
+    let mut s = super::session();
+    s.execute("file.openDemoProject", json!({})).unwrap();
+    let out = dir.join("[compName]_[width]x[height].[fileExtension]");
+    let r = s
+        .execute(
+            "renderQueue.add",
+            json!({"format": "h264", "output": out.to_string_lossy(), "resolution": 0.125, "timeSpan": "custom", "start": 0.0, "end": 0.4}),
+        )
+        .unwrap();
+    let path = r["outputPath"].as_str().unwrap().to_string();
+    assert!(path.ends_with("_240x134.mp4"), "{path}");
+    // A second item: PNG sequence, rendered in the background.
+    s.execute(
+        "renderQueue.add",
+        json!({"format": "png", "output": dir.join("seq_[###].png").to_string_lossy(), "resolution": 0.0625, "timeSpan": "custom", "start": 0.0, "end": 0.2}),
+    )
+    .unwrap();
+    let r = s.execute("renderQueue.render", json!({"wait": false})).unwrap();
+    assert_eq!(r["items"].as_array().unwrap().len(), 2);
+    let t0 = std::time::Instant::now();
+    while s.is_rendering() {
+        assert!(t0.elapsed().as_secs() < 300, "render timed out");
+        std::thread::sleep(std::time::Duration::from_millis(20));
+        s.poll_render();
+    }
+    s.poll_render();
+    let list = s.execute("renderQueue.list", json!({})).unwrap();
+    for it in list["items"].as_array().unwrap() {
+        assert_eq!(it["statusLabel"], "Done", "{it}");
+        assert!(it["render_time"].as_f64().is_some());
+        assert!(std::path::Path::new(it["last_output"].as_str().unwrap()).exists(), "{it}");
+    }
+    assert!(std::path::Path::new(&path).metadata().unwrap().len() > 500);
+    assert!(dir.join("seq_000.png").exists() && dir.join("seq_005.png").exists() && !dir.join("seq_006.png").exists());
+    // Rendering again needs a re-queue.
+    assert!(s.execute("renderQueue.render", json!({})).is_err());
+    s.execute("renderQueue.setRender", json!({"index": 1, "render": true})).unwrap();
+    assert_eq!(s.project.render_queue[0].status, effectcraft_engine::project::render_queue::RenderStatus::Queued);
+}
+
+/// Value of a property of layer `l` at time 0 (keys + expression).
+fn value(s: &effectcraft_engine::Session, l: u64, path: &str) -> effectcraft_engine::keyframe::Value {
+    let cid = s.active_comp_id().unwrap();
+    let comp = s.project.comp(cid).unwrap();
+    let layer = comp.layer(effectcraft_engine::project::LayerId(l)).unwrap();
+    let ctx = effectcraft_engine::render::EvalCtx { project: &s.project, comp_id: cid, comp, time: Default::default(), expr: s.expr.as_deref(), footage: None };
+    ctx.value(layer, layer.props.prop(path).unwrap())
+}
+
+#[test]
+fn pick_whip_expressions_evaluate() {
+    let mut s = super::session();
+    s.execute("comp.new", json!({"name": "C", "width": 200, "height": 200, "frameRate": 30, "duration": 2})).unwrap();
+    let a = s.execute("layer.newSolid", json!({"color": "#ffffff"})).unwrap()["layer"].as_u64().unwrap();
+    let b = s.execute("layer.newSolid", json!({"name": "Src", "color": "#ff0000"})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("prop.set", json!({"layer": b, "path": "transform/rotation", "value": 33})).unwrap();
+    s.execute("prop.set", json!({"layer": b, "path": "transform/position", "value": [12, 34]})).unwrap();
+    s.execute("effect.apply", json!({"layer": b, "effect": "Gaussian Blur"})).unwrap();
+    s.execute("prop.set", json!({"layer": b, "path": "effects/#1/blurriness", "value": 21})).unwrap();
+    s.execute("layer.addMask", json!({"layer": b})).unwrap();
+    s.execute("prop.set", json!({"layer": b, "path": "masks/#1/feather", "value": [7, 7]})).unwrap();
+    let link = |s: &mut effectcraft_engine::Session, from: &str, to: &str| {
+        s.execute("prop.pickWhip", json!({"layer": a, "path": from, "target": {"layer": b, "path": to}})).unwrap();
+    };
+    link(&mut s, "transform/opacity", "transform/rotation");
+    assert_eq!(value(&s, a, "transform/opacity").as_f64(), 33.0);
+    link(&mut s, "transform/scale", "transform/rotation");
+    let cid = s.active_comp_id().unwrap();
+    let ep = effectcraft_expr::eval_property(&s.project, cid, effectcraft_engine::project::LayerId(a), "transform/scale", 0.0);
+    assert!(ep.is_ok(), "{ep:?}");
+    assert_eq!(value(&s, a, "transform/scale").as_vec2(), [33.0, 33.0]);
+    link(&mut s, "transform/position", "transform/position");
+    assert_eq!(value(&s, a, "transform/position").as_vec2(), [12.0, 34.0]);
+    link(&mut s, "transform/rotation", "effects/#1/blurriness");
+    assert_eq!(value(&s, a, "transform/rotation").as_f64(), 21.0);
+    link(&mut s, "transform/opacity", "masks/#1/feather");
+    assert_eq!(value(&s, a, "transform/opacity").as_f64(), 7.0);
+    // Separated dimensions: X Position reference.
+    s.execute("prop.separateDimensions", json!({"layer": b})).unwrap();
+    link(&mut s, "transform/rotation", "transform/positionX");
+    assert_eq!(value(&s, a, "transform/rotation").as_f64(), 12.0);
+}
+
+/// The expression error bar's list: evaluation errors and syntax errors, with the layer and
+/// property they belong to.
+#[test]
+fn expression_errors_are_collected() {
+    let mut s = super::session();
+    s.execute("comp.new", json!({"name": "C", "width": 100, "height": 100, "frameRate": 30, "duration": 2})).unwrap();
+    let a = s.execute("layer.newSolid", json!({"name": "Box", "color": "#ffffff"})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("prop.setExpression", json!({"layer": a, "path": "transform/opacity", "expression": "50"})).unwrap();
+    assert_eq!(s.execute("expr.errors", json!({})).unwrap()["count"], 0);
+    s.execute("prop.setExpression", json!({"layer": a, "path": "transform/rotation", "expression": "thisComp.layer(\"Nope\").rotation"})).unwrap();
+    s.execute("prop.setExpression", json!({"layer": a, "path": "transform/opacity", "expression": "1 +* ("})).unwrap();
+    let r = s.execute("expr.errors", json!({})).unwrap();
+    assert_eq!(r["count"], 2, "{r}");
+    let errs = r["errors"].as_array().unwrap();
+    let rot = errs.iter().find(|e| e["path"] == "transform/rotation").unwrap();
+    assert!(rot["message"].as_str().unwrap().contains("Nope"), "{rot}");
+    assert_eq!(rot["layerIndex"], 1);
+    assert_eq!(rot["layerName"], "Box");
+    assert_eq!(rot["disabled"], false);
+    let op = errs.iter().find(|e| e["path"] == "transform/opacity").unwrap();
+    assert_eq!(op["disabled"], true);
+    assert!(r["text"][0].as_str().unwrap().contains("of layer 1 ('Box') in comp 'C'"), "{r}");
+    // A user-disabled (but valid) expression is not an error.
+    s.execute("prop.setExpression", json!({"layer": a, "path": "transform/rotation", "expression": "45"})).unwrap();
+    s.execute("prop.setExpression", json!({"layer": a, "path": "transform/rotation", "enabled": false})).unwrap();
+    assert_eq!(s.execute("expr.errors", json!({})).unwrap()["count"], 1);
+    // The Expression Language menu is categorised.
+    let m = s.execute("expr.languageMenu", json!({})).unwrap();
+    assert!(m.as_array().unwrap().iter().any(|c| c["category"] == "Footage" && c["items"].as_array().unwrap().iter().any(|i| i["text"] == "sourceData")));
+}
+
+/// File ▸ Import of JSON/CSV data files as data footage, read by expressions.
+#[test]
+fn imported_data_files_drive_expressions() {
+    let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/host-data");
+    let _ = std::fs::remove_dir_all(&dir);
+    std::fs::create_dir_all(&dir).unwrap();
+    std::fs::write(dir.join("levels.csv"), "label,value\nlow,10\nhigh,90\n").unwrap();
+    std::fs::write(dir.join("cfg.json"), r#"{"angle": 33}"#).unwrap();
+    std::fs::write(dir.join("broken.json"), "{nope").unwrap();
+    let mut s = super::session();
+    s.execute("comp.new", json!({"name": "C", "width": 100, "height": 100, "frameRate": 30, "duration": 2})).unwrap();
+    let paths: Vec<String> = ["levels.csv", "cfg.json", "broken.json"].iter().map(|n| dir.join(n).to_string_lossy().to_string()).collect();
+    let r = s.execute("file.import", json!({"paths": paths})).unwrap();
+    assert_eq!(r["items"].as_array().unwrap().len(), 2, "{r}");
+    assert_eq!(r["errors"].as_array().unwrap().len(), 1, "{r}");
+    let csv = r["items"][0].as_u64().unwrap();
+    assert_eq!(s.project.item(effectcraft_engine::project::ItemId(csv)).unwrap().type_name(), "Data");
+    assert!(s.execute("layer.addItem", json!({"item": csv})).is_err(), "data files are not layers");
+    let a = s.execute("layer.newSolid", json!({"color": "#ffffff"})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("prop.setExpression", json!({"layer": a, "path": "transform/opacity", "expression": "footage(\"levels.csv\").sourceData[1].value"})).unwrap();
+    s.execute("prop.setExpression", json!({"layer": a, "path": "transform/rotation", "expression": "footage(\"cfg.json\").sourceData.angle"})).unwrap();
+    assert_eq!(value(&s, a, "transform/opacity").as_f64(), 90.0);
+    assert_eq!(value(&s, a, "transform/rotation").as_f64(), 33.0);
+}
+
+/// sampleImage through the renderer: a box's Fill colour follows the solid under it.
+#[test]
+fn sample_image_drives_a_colour() {
+    let mut s = super::session();
+    s.execute("comp.new", json!({"name": "C", "width": 100, "height": 100, "frameRate": 30, "duration": 2})).unwrap();
+    s.execute("layer.newSolid", json!({"name": "Bg", "color": "#00ff00"})).unwrap();
+    let a = s.execute("layer.newSolid", json!({"name": "Fg", "color": "#ffffff", "width": 20, "height": 20})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("effect.apply", json!({"layer": a, "effect": "Fill"})).unwrap();
+    s.execute(
+        "prop.setExpression",
+        json!({"layer": a, "path": "effects/#1/color", "expression": "thisComp.layer(\"Bg\").sampleImage(thisComp.layer(\"Bg\").fromComp(toComp(anchorPoint)))"}),
+    )
+    .unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let img = s.render(cid, s.time(), effectcraft_engine::render::RenderOpts::default());
+    let px = img.get(50, 50);
+    assert!(px[1] > 0.99 && px[0] < 0.01, "the box is filled with the sampled green: {px:?}");
+}
+
+/// Proxies through the real media and export layers: Render Settings ▸ Proxy Use decides
+/// whether an export uses the proxy, and Create Proxy renders and attaches one.
+#[test]
+fn proxies_in_exports_and_create_proxy() {
+    let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/host-proxy");
+    let _ = std::fs::remove_dir_all(&dir);
+    std::fs::create_dir_all(&dir).unwrap();
+    let p = |n: &str| dir.join(n).to_string_lossy().to_string();
+    let mut s = super::session();
+    // Source and proxy stills, written by the app itself.
+    s.execute("comp.new", json!({"name": "Red", "width": 16, "height": 16, "frameRate": 10, "duration": 1})).unwrap();
+    let red = s.active_comp_id().unwrap();
+    s.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap();
+    s.execute("comp.saveFrameAs", json!({"path": p("red.png")})).unwrap();
+    s.execute("comp.new", json!({"name": "Blue", "width": 8, "height": 8, "frameRate": 10, "duration": 1})).unwrap();
+    s.execute("layer.newSolid", json!({"color": "#0000ff"})).unwrap();
+    s.execute("comp.saveFrameAs", json!({"path": p("blue.png")})).unwrap();
+    let foot = s.execute("file.import", json!({"paths": [p("red.png")]})).unwrap()["items"][0].as_u64().unwrap();
+    s.execute("file.setProxy", json!({"item": foot, "path": p("blue.png")})).unwrap();
+    s.execute("comp.new", json!({"name": "Out", "width": 16, "height": 16, "frameRate": 10, "duration": 1})).unwrap();
+    let out = s.active_comp_id().unwrap();
+    s.execute("layer.addItem", json!({"item": foot})).unwrap();
+    // Export one frame with each Proxy Use.
+    for (name, using) in [("all", "use_all_[#].png"), ("none", "use_none_[#].png")] {
+        s.execute(
+            "renderQueue.add",
+            json!({"comp": out.0, "format": "png", "output": p(using), "timeSpan": "custom", "start": 0.0, "end": 0.1, "proxyUse": name}),
+        )
+        .unwrap();
+    }
+    s.execute("renderQueue.render", json!({"wait": true})).unwrap();
+    s.poll_render();
+    let centre = |s: &mut effectcraft_engine::Session, path: &str| {
+        let id = s.execute("file.import", json!({"paths": [path]})).unwrap()["items"][0].as_u64().unwrap();
+        s.execute("comp.new", json!({"name": "Probe", "width": 16, "height": 16, "frameRate": 10, "duration": 1})).unwrap();
+        s.execute("layer.addItem", json!({"item": id})).unwrap();
+        let c = s.active_comp_id().unwrap();
+        s.render(c, Default::default(), Default::default()).get(8, 8)
+    };
+    let all = centre(&mut s, &p("use_all_0.png"));
+    assert!(all[2] > 0.99 && all[0] < 0.01, "Use All Proxies renders the blue proxy: {all:?}");
+    let none = centre(&mut s, &p("use_none_0.png"));
+    assert!(none[0] > 0.99 && none[2] < 0.01, "Use No Proxies renders the red source: {none:?}");
+    // Create Proxy ▸ Still: rendered at half size and attached to the comp.
+    s.execute("file.createProxy", json!({"kind": "still", "comp": red.0, "path": p("red_proxy_[#####].png")})).unwrap();
+    s.execute("renderQueue.render", json!({"wait": true})).unwrap();
+    s.poll_render();
+    let px = s.project.item(red).unwrap().proxy.clone().expect("Create Proxy attached the rendered still");
+    assert!(px.enabled);
+    assert_eq!((px.footage.width, px.footage.height), (8, 8));
+    assert!(std::path::Path::new(&px.footage.path).exists(), "{}", px.footage.path);
+}
+
+/// A script builds a comp, queues it and renders it through the Render Queue.
+#[test]
+fn script_renders_through_the_render_queue() {
+    let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/host-script");
+    let _ = std::fs::remove_dir_all(&dir);
+    let out = dir.join("scripted.gif");
+    let mut s = super::session();
+    let code = format!(
+        r#"
+            var comp = app.project.items.addComp("Scripted", 64, 48, 1, 0.2, 10);
+            var sq = comp.layers.addSolid([1, 0.5, 0], "Square", 16, 16, 1);
+            sq.transform.position.setValueAtTime(0, [8, 24]);
+            sq.transform.position.setValueAtTime(0.1, [56, 24]);
+            var item = app.project.renderQueue.items.add(comp);
+            item.outputModule(1).applyTemplate("GIF");
+            item.outputModule(1).file = new File({});
+            app.project.renderQueue.render();
+            [item.status == RQItemStatus.DONE, item.outputModule(1).file.fsName, app.project.renderQueue.numItems]
+            "#,
+        serde_json::to_string(&out.to_string_lossy()).unwrap()
+    );
+    let r = s.execute("script.run", json!({"code": code})).unwrap();
+    assert_eq!(r["ok"], json!(true), "{r}");
+    assert_eq!(r["result"][0], json!(true), "{r}");
+    assert_eq!(r["result"][2], json!(1));
+    let bytes = std::fs::read(&out).unwrap();
+    assert!(bytes.starts_with(b"GIF89a"));
+}
+
+/// importFile, layers.add(footage) and project save/open from a script.
+#[test]
+fn script_imports_footage_and_saves() {
+    let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../target/test-out/host-script-import");
+    let _ = std::fs::remove_dir_all(&dir);
+    std::fs::create_dir_all(&dir).unwrap();
+    let q = |n: &str| serde_json::to_string(&dir.join(n).to_string_lossy()).unwrap();
+    let mut s = super::session();
+    let code = format!(
+        r#"
+            var c = app.project.items.addComp("Src", 32, 32, 1, 1, 10);
+            c.layers.addSolid([0, 1, 0], "G", 32, 32, 1);
+            app.run("comp.saveFrameAs", {{comp: c.id, path: {png}}});
+            var still = app.project.importFile(new ImportOptions(new File({png})));
+            var main = app.project.items.addComp("Main", 64, 64, 1, 1, 10);
+            var l = main.layers.add(still);
+            app.project.save(new File({proj}));
+            [still instanceof FootageItem, still.width, still.mainSource.isStill, l.source.name, app.project.file.name]
+            "#,
+        png = q("frame.png"),
+        proj = q("p.ecproj")
+    );
+    let r = s.execute("script.run", json!({"code": code})).unwrap();
+    assert_eq!(r["ok"], json!(true), "{r}");
+    assert_eq!(r["result"], json!([true, 32, true, "frame.png", "p.ecproj"]), "{r}");
+    let r = s.execute("script.run", json!({"code": format!("app.open(new File({})); app.project.numItems", q("p.ecproj"))})).unwrap();
+    assert_eq!(r["result"], json!(5), "{r}"); // Src, Solids, G, frame.png, Main
+}
+
+#[test]
+fn expression_syntax_errors_disable_the_expression() {
+    let mut s = super::session();
+    s.execute("comp.new", json!({"name": "C", "width": 100, "height": 100, "frameRate": 30, "duration": 2})).unwrap();
+    let a = s.execute("layer.newSolid", json!({"color": "#ffffff"})).unwrap()["layer"].as_u64().unwrap();
+    let r = s.execute("prop.setExpression", json!({"layer": a, "path": "transform/opacity", "expression": "1 +* ("})).unwrap();
+    assert!(r["error"].is_string(), "{r}");
+    let pr = s.active_comp().unwrap().layers[0].props.prop("transform/opacity").unwrap().clone();
+    assert!(!pr.expr.unwrap().enabled);
+    assert_eq!(value(&s, a, "transform/opacity").as_f64(), 100.0);
+    s.execute("prop.setExpression", json!({"layer": a, "path": "transform/opacity", "expression": "50"})).unwrap();
+    assert_eq!(value(&s, a, "transform/opacity").as_f64(), 50.0);
+}
+/// Create Stereo 3D Rig: the eye cameras' expressions follow the master camera and the
+/// Stereo 3D Controls (and agree with the values the command wrote).
+#[test]
+fn stereo_rig_expressions_follow_the_master_camera() {
+    let mut s = super::session();
+    s.execute("comp.new", json!({"name": "Shot", "width": 640, "height": 360, "frameRate": 30, "duration": 2})).unwrap();
+    let src = s.active_comp_id().unwrap();
+    let cam = s.execute("layer.newCamera", json!({"name": "Main", "position": [320, 180, -800], "poi": [320, 180, 0], "zoom": 900})).unwrap()["layer"]
+        .as_u64()
+        .unwrap();
+    let r = s.execute("camera.stereoRig", json!({"sceneDepth": 4})).unwrap();
+    let ctl = r["controls"].as_u64().unwrap();
+    let left = effectcraft_engine::project::ItemId(r["leftComp"].as_u64().unwrap());
+    // The left eye camera's evaluated value (expressions on).
+    let v3 = |s: &effectcraft_engine::Session, path: &str| {
+        let comp = s.project.comp(left).unwrap();
+        let layer = &comp.layers[0];
+        let ctx =
+            effectcraft_engine::render::EvalCtx { project: &s.project, comp_id: left, comp, time: Default::default(), expr: s.expr.as_deref(), footage: None };
+        ctx.value(layer, layer.props.prop(path).unwrap()).as_vec3()
+    };
+    let close = |a: [f64; 3], b: [f64; 3]| (0..3).all(|i| (a[i] - b[i]).abs() < 1e-6);
+    let d = 0.04 * 640.0;
+    assert!(close(v3(&s, "transform/position"), [320.0 - d / 2.0, 180.0, -800.0]), "{:?}", v3(&s, "transform/position"));
+    assert!(close(v3(&s, "transform/poi"), [320.0 - d / 2.0, 180.0, 0.0]), "{:?}", v3(&s, "transform/poi"));
+    // Moving the master moves the eyes.
+    s.execute("comp.open", json!({"comp": src.0})).unwrap();
+    s.execute("prop.set", json!({"layer": cam, "path": "transform/position", "value": [300, 180, -800]})).unwrap();
+    s.execute("prop.set", json!({"layer": cam, "path": "transform/poi", "value": [300, 180, 0]})).unwrap();
+    assert!(close(v3(&s, "transform/position"), [300.0 - d / 2.0, 180.0, -800.0]), "{:?}", v3(&s, "transform/position"));
+    // Controls: Center & Left puts the left eye a full separation left; convergence toes in.
+    s.execute("prop.set", json!({"layer": ctl, "path": "effects/#1/configuration", "value": 2})).unwrap();
+    s.execute("prop.set", json!({"layer": ctl, "path": "effects/#1/convergence", "value": true})).unwrap();
+    assert!(close(v3(&s, "transform/position"), [300.0 - d, 180.0, -800.0]), "{:?}", v3(&s, "transform/position"));
+    assert!(close(v3(&s, "transform/poi"), [300.0, 180.0, 0.0]), "{:?}", v3(&s, "transform/poi"));
+}
diff --git a/crates/keyframe/src/lib.rs b/crates/keyframe/src/lib.rs
index 83774764d..f2d94f177 100644
--- a/crates/keyframe/src/lib.rs
+++ b/crates/keyframe/src/lib.rs
@@ -647,402 +647,4 @@ pub fn easy_ease(k: &mut Keyframe, ease_in: bool, ease_out: bool) {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn s(x: f64) -> Tick {
-        Tick::from_seconds_f64(x)
-    }
-
-    #[test]
-    fn missing_spatial_keys_have_no_tangents_or_length() {
-        let keys = vec![Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0]))];
-        for i in [1, usize::MAX] {
-            assert_eq!(spatial_tangents(&keys, i), ([0.0; 3], [0.0; 3]));
-            assert_eq!(spatial_segment_length(&keys, i), 0.0);
-        }
-        assert_eq!(spatial_tangents(&[], 0), ([0.0; 3], [0.0; 3]));
-        assert_eq!(spatial_segment_length(&[], usize::MAX), 0.0);
-    }
-
-    #[test]
-    fn time_reverse_handles_deserialized_tick_extremes() {
-        // Tick's public serde representation can contain values beyond from_seconds_f64's cap.
-        for (first, last) in [(i64::MIN, i64::MIN + 10), (i64::MAX - 10, i64::MAX), (i64::MIN, i64::MAX)] {
-            let mut keys = vec![Keyframe::new(Tick(first), Value::Scalar(1.0)), Keyframe::new(Tick(last), Value::Scalar(2.0))];
-            time_reverse(&mut keys);
-            assert_eq!(keys[0].time, Tick(first));
-            assert_eq!(keys[0].value, Value::Scalar(2.0));
-            assert_eq!(keys[1].time, Tick(last));
-            assert_eq!(keys[1].value, Value::Scalar(1.0));
-            time_reverse(&mut keys);
-            assert_eq!(keys[0].value, Value::Scalar(1.0));
-        }
-    }
-
-    #[test]
-    fn roving_handles_deserialized_tick_extremes() {
-        let mut keys = vec![
-            Keyframe::new(Tick(i64::MIN), Value::Vec2([0.0, 0.0])),
-            Keyframe::new(Tick(10), Value::Vec2([50.0, 0.0])),
-            Keyframe::new(Tick(i64::MAX), Value::Vec2([100.0, 0.0])),
-        ];
-        for key in &mut keys {
-            key.spatial_auto = false;
-        }
-        keys[1].roving = true;
-        assert!(retime_roving(&mut keys, true));
-        assert_eq!(keys[1].time, Tick::ZERO);
-    }
-
-    #[test]
-    fn replacing_key_preserves_spatial_metadata() {
-        let mut key = Keyframe::new(s(1.0), Value::Vec2([20.0, 30.0]));
-        key.roving = true;
-        key.spatial_continuous = true;
-        let mut keys = vec![key];
-        set_key(&mut keys, Keyframe::new(s(1.0), Value::Vec2([40.0, 50.0])));
-        assert!(keys[0].roving);
-        assert!(keys[0].spatial_continuous);
-        assert_eq!(keys[0].value, Value::Vec2([40.0, 50.0]));
-    }
-
-    #[test]
-    fn temporal_ease_matches_live_ae_with_overlapping_influences() {
-        // Original Rotation probe via AEsync 2.0.4, AE 26.3x87, 2026-10-05.
-        // AE retains each handle's requested influence even when their sum exceeds 100%.
-        for (from, to, out_speed, out_inf, in_speed, in_inf, samples) in [
-            (0.0, 100.0, 0.0, 0.8, 0.0, 0.8, [(0.1, 0.59243939036327), (0.25, 4.76438030608764), (0.4, 18.4284394271562), (0.75, 95.2356196939123)]),
-            (0.0, 100.0, 20.0, 0.8, 80.0, 0.6, [(0.1, 2.25754942621577), (0.25, 6.99841889412931), (0.4, 14.9334636959052), (0.75, 73.8196785378389)]),
-            (100.0, 0.0, -20.0, 0.6, -80.0, 0.8, [(0.1, 97.6395466334594), (0.25, 91.597048571292), (0.4, 74.5367957474338), (0.75, 22.3789127753126)]),
-        ] {
-            let mut a = Keyframe::new(s(0.0), Value::Scalar(from));
-            let mut b = Keyframe::new(s(1.0), Value::Scalar(to));
-            a.out_interp = Interp::Bezier;
-            b.in_interp = Interp::Bezier;
-            a.out_ease = vec![Ease { speed: out_speed, influence: out_inf }];
-            b.in_ease = vec![Ease { speed: in_speed, influence: in_inf }];
-            for (time, expected) in samples {
-                let value = evaluate(&[a.clone(), b.clone()], s(time), false).unwrap().as_f64();
-                assert!((value - expected).abs() < 1e-7, "{time}: {value} != {expected}");
-                let normalized = ease_progress(out_speed / (to - from), out_inf, in_speed / (to - from), in_inf, time);
-                assert!((from + normalized * (to - from) - expected).abs() < 1e-7);
-            }
-        }
-    }
-
-    #[test]
-    fn maximum_influence_resolves_flat_midpoint_time_curve() {
-        for time in [0.5 - 1e-9, 0.5 - 1e-12, 0.5, 0.5 + 1e-12, 0.5 + 1e-9] {
-            // At 100%/100%, x = 0.5 + 4*(u - 0.5)^3 exactly.
-            let u = 0.5 + ((time - 0.5) / 4.0_f64).cbrt();
-            let expected = bez(0.0, 0.0, 1.0, 1.0, u);
-            let actual = ease_progress(0.0, 1.0, 0.0, 1.0, time);
-            assert!((actual - expected).abs() < 1e-10, "{time}: {actual} != {expected}");
-        }
-    }
-
-    /// M13.15: agents set gradients as plain JSON, not only the tagged form `get` returns.
-    #[test]
-    fn gradients_coerce_from_plain_json() {
-        let g = Value::Gradient(Gradient::default());
-        let plain = serde_json::json!({"colors": [[0, [0, 0.5, 1, 1]], [1, "#ffff00"]], "opacities": [[0, 1], [1, 0.5]]});
-        let Some(Value::Gradient(a)) = g.coerce_json(&plain) else { panic!("object form") };
-        assert_eq!(a.colors, vec![(0.0, [0.0, 0.5, 1.0, 1.0]), (1.0, [1.0, 1.0, 0.0, 1.0])]);
-        assert_eq!(a.opacities, vec![(0.0, 1.0), (1.0, 0.5)]);
-        let Some(Value::Gradient(b)) = g.coerce_json(&serde_json::json!(["#ff0000", "#00ff00", "#0000ff"])) else { panic!("list form") };
-        assert_eq!(b.colors.iter().map(|c| c.0).collect::<Vec<_>>(), vec![0.0, 0.5, 1.0]);
-        assert_eq!(b.opacities.len(), 3);
-        // The tagged form (what prop.get returns) still round-trips.
-        assert_eq!(g.coerce_json(&g.to_json()), Some(g.clone()));
-        assert_eq!(g.coerce_json(&serde_json::json!(5)), None);
-    }
-
-    /// #612: the gradient editor samples a new stop from its own track only. `sample` multiplies
-    /// in the opacity stops, so feeding its alpha into a colour stop would apply 50% twice (25%).
-    #[test]
-    fn gradient_tracks_sample_separately() {
-        let g = Gradient { colors: vec![(0.0, [1.0, 0.0, 0.0, 0.8]), (1.0, [0.0, 0.0, 1.0, 0.4])], opacities: vec![(0.0, 0.5), (1.0, 0.5)] };
-        let c = g.color_at(0.5);
-        assert!((c[0] - 0.5).abs() < 1e-6 && (c[2] - 0.5).abs() < 1e-6, "{c:?}");
-        assert!((c[3] - 0.6).abs() < 1e-6, "the colour track's own alpha, without opacity: {c:?}");
-        assert!((g.opacity_at(0.5) - 0.5).abs() < 1e-6);
-        assert!((g.sample(0.5)[3] - 0.3).abs() < 1e-6, "sample still applies opacity once");
-        // A stop added at 50% from the opacity track keeps 50%: sampled again, it is still 50%.
-        let mut with_stop = g.clone();
-        with_stop.opacities.insert(1, (0.5, g.opacity_at(0.5)));
-        assert!((with_stop.opacity_at(0.5) - 0.5).abs() < 1e-6);
-        assert!((with_stop.sample(0.5)[3] - 0.3).abs() < 1e-6, "adding a stop doesn't change the look");
-        // Outside the stops, and with none: the ends hold, and an empty track is opaque white.
-        assert_eq!(g.color_at(-1.0), [1.0, 0.0, 0.0, 0.8]);
-        assert_eq!(g.color_at(2.0), [0.0, 0.0, 1.0, 0.4]);
-        let empty = Gradient { colors: vec![], opacities: vec![] };
-        assert_eq!((empty.color_at(0.3), empty.opacity_at(0.3)), ([1.0; 4], 1.0));
-    }
-
-    /// #612: the editor saves the typed form, so one colour stop (which the plain JSON parser
-    /// rejects) and each stop's RGBA come back exactly.
-    #[test]
-    fn typed_gradient_round_trips_one_stop_and_rgba() {
-        let one = Value::Gradient(Gradient { colors: vec![(0.25, [0.1, 0.2, 0.3, 0.7])], opacities: vec![(0.0, 1.0), (0.6, 0.35)] });
-        let cur = Value::Gradient(Gradient::default());
-        assert_eq!(cur.coerce_json(&one.to_json()), Some(one.clone()));
-        assert_eq!(cur.coerce_json(&serde_json::json!({"colors": [[0.25, [0.1, 0.2, 0.3, 0.7]]]})), None, "plain JSON needs two colours");
-    }
-
-    #[test]
-    fn linear_and_hold() {
-        let keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)), Keyframe::new(s(2.0), Value::Scalar(100.0))];
-        assert_eq!(evaluate(&keys, s(1.0), false), Some(Value::Scalar(50.0)));
-        assert_eq!(evaluate(&keys, s(-1.0), false), Some(Value::Scalar(0.0)));
-        assert_eq!(evaluate(&keys, s(3.0), false), Some(Value::Scalar(100.0)));
-        let held = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)).hold(), Keyframe::new(s(2.0), Value::Scalar(100.0))];
-        assert_eq!(evaluate(&held, s(1.999), false), Some(Value::Scalar(0.0)));
-    }
-
-    #[test]
-    fn hold_key_keeps_its_incoming_segment_linear() {
-        // Hold on the second key (in and out, as KeyframeInterpolationType.HOLD sets it) holds
-        // what comes after it, not the linear motion into it.
-        let keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)), Keyframe::new(s(2.0), Value::Scalar(100.0)).hold()];
-        assert_eq!(evaluate(&keys, s(0.5), false), Some(Value::Scalar(25.0)));
-        let keys = vec![Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0])), Keyframe::new(s(2.0), Value::Vec2([100.0, 0.0])).hold()];
-        let p = evaluate(&keys, s(0.5), true).unwrap().as_vec2();
-        assert!((p[0] - 25.0).abs() < 0.01, "{p:?}");
-    }
-
-    #[test]
-    fn easy_ease_is_symmetric_and_slow_at_ends() {
-        let keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)).eased(), Keyframe::new(s(1.0), Value::Scalar(100.0)).eased()];
-        let mid = evaluate(&keys, s(0.5), false).unwrap().as_f64();
-        assert!((mid - 50.0).abs() < 1e-6, "{mid}");
-        let early = evaluate(&keys, s(0.1), false).unwrap().as_f64();
-        assert!(early < 10.0 && early > 0.0, "{early}");
-        let v0 = velocity(&keys, s(0.01), false)[0];
-        let vm = velocity(&keys, s(0.5), false)[0];
-        assert!(v0 < vm);
-    }
-
-    #[test]
-    fn bezier_with_linear_speed_matches_linear() {
-        let mut a = Keyframe::new(s(0.0), Value::Scalar(0.0));
-        let mut b = Keyframe::new(s(2.0), Value::Scalar(100.0));
-        a.out_interp = Interp::Bezier;
-        b.in_interp = Interp::Bezier;
-        a.out_ease = vec![Ease { speed: 50.0, influence: 1.0 / 3.0 }];
-        b.in_ease = vec![Ease { speed: 50.0, influence: 1.0 / 3.0 }];
-        let keys = vec![a, b];
-        for i in 0..=20 {
-            let t = i as f64 * 0.1;
-            let v = evaluate(&keys, s(t), false).unwrap().as_f64();
-            assert!((v - 50.0 * t).abs() < 1e-6, "{t} {v}");
-        }
-    }
-
-    #[test]
-    fn spatial_linear_constant_speed() {
-        let keys = vec![Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0])), Keyframe::new(s(1.0), Value::Vec2([300.0, 400.0]))];
-        let p = evaluate(&keys, s(0.5), true).unwrap().as_vec2();
-        assert!((p[0] - 150.0).abs() < 0.5 && (p[1] - 200.0).abs() < 0.5, "{p:?}");
-    }
-
-    /// #456: along a curved spatial path with linear (constant-speed) keys the speed graph is
-    /// flat, not a sawtooth from a piecewise-linear arc-length table.
-    #[test]
-    fn spatial_curved_path_has_smooth_constant_speed() {
-        let mut a = Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0]));
-        let mut b = Keyframe::new(s(2.0), Value::Vec2([400.0, 0.0]));
-        a.spatial_auto = false;
-        b.spatial_auto = false;
-        a.spatial_out = [50.0, -300.0, 0.0];
-        b.spatial_in = [80.0, 250.0, 0.0];
-        let keys = vec![a, b];
-        let len = spatial_segment_length(&keys, 0);
-        let speeds: Vec<f64> = (1..400).map(|i| speed(&keys, s(i as f64 * 0.005), true)).collect();
-        for v in &speeds {
-            assert!((v - len / 2.0).abs() < 1e-3 * len, "speed {v} vs {}", len / 2.0);
-        }
-    }
-
-    #[test]
-    fn spatial_auto_bezier_passes_through_keys() {
-        let keys = vec![
-            Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0])),
-            Keyframe::new(s(1.0), Value::Vec2([100.0, 100.0])),
-            Keyframe::new(s(2.0), Value::Vec2([200.0, 0.0])),
-        ];
-        let p = evaluate(&keys, s(1.0), true).unwrap().as_vec2();
-        assert_eq!(p, [100.0, 100.0]);
-        // Curved: the midpoint of the first segment lies off the straight line.
-        let m = evaluate(&keys, s(0.5), true).unwrap().as_vec2();
-        assert!((m[0] - m[1]).abs() > 1.0, "{m:?}");
-    }
-
-    #[test]
-    fn straight_auto_bezier_path_is_exact() {
-        // Auto-Bezier ends now have handles along the line; the chord is still hit exactly.
-        let keys = vec![Keyframe::new(s(0.0), Value::Vec2([40.0, 50.0])), Keyframe::new(s(2.0), Value::Vec2([120.0, 50.0]))];
-        assert_eq!(segment_value(&keys, 0, s(1.0), true), Value::Vec2([80.0, 50.0]));
-    }
-
-    /// #880: a motion path whose arc length overflows (huge coordinates, as the Position field
-    /// accepts) or is NaN evaluates without panicking: scrubbing over it crashed the app.
-    #[test]
-    fn overflowing_or_nan_motion_paths_evaluate() {
-        let paths = [
-            [[-1.7e308, 0.0], [1.7e308, 0.0], [-1.7e308, 5.0]],
-            [[0.0, 0.0], [f64::NAN, 10.0], [20.0, 0.0]],
-            [[f64::INFINITY, 0.0], [0.0, f64::NEG_INFINITY], [20.0, 0.0]],
-        ];
-        for path in paths {
-            let mut keys: Vec<Keyframe> = path.iter().enumerate().map(|(i, &v)| Keyframe::new(s(i as f64 * 2.0), Value::Vec2(v))).collect();
-            for eased in [false, true] {
-                if eased {
-                    keys = keys.into_iter().map(Keyframe::eased).collect();
-                }
-                for f in 0..=40 {
-                    let t = s(f as f64 * 0.1);
-                    assert!(evaluate(&keys, t, true).is_some());
-                    let _ = speed(&keys, t, true);
-                }
-            }
-        }
-    }
-
-    #[test]
-    fn spatial_auto_bezier_tangents_follow_after_effects() {
-        // Measured on After Effects 26.3 with original paths (docs/fidelity/README.md): each
-        // auto-Bezier key's out tangent is (next - previous) / 6 and its in tangent the mirror,
-        // whatever the key times. End keys use their one neighbour: (neighbour - key) / 6.
-        let p = [[40.0, 300.0, 0.0], [260.0, 80.0, 20.0], [700.0, 420.0, -40.0], [1100.0, 150.0, 0.0]];
-        let mut keys: Vec<Keyframe> = [0.0, 0.2, 1.5, 1.8].iter().zip(p).map(|(&t, v)| Keyframe::new(s(t), Value::Vec3(v))).collect();
-        let sixth = |a: [f64; 3], b: [f64; 3]| [(b[0] - a[0]) / 6.0, (b[1] - a[1]) / 6.0, (b[2] - a[2]) / 6.0];
-        let neg = |v: [f64; 3]| [-v[0], -v[1], -v[2]];
-        let close = |a: [f64; 3], b: [f64; 3]| a.iter().zip(b).all(|(x, y)| (x - y).abs() < 1e-9);
-        let want = [sixth(p[0], p[1]), sixth(p[0], p[2]), sixth(p[1], p[3]), sixth(p[2], p[3])];
-        for (i, out) in want.into_iter().enumerate() {
-            let (tin, tout) = spatial_tangents(&keys, i);
-            assert!(close(tout, out) && close(tin, neg(out)), "key {i}: {tin:?} {tout:?}");
-        }
-        // Moving a key in time leaves every tangent as it was.
-        keys[1].time = s(1.2);
-        assert!(close(spatial_tangents(&keys, 1).1, sixth(p[0], p[2])));
-        // A key between two coincident neighbours, and a lone key, have none.
-        let still = [[5.0, 5.0], [9.0, 1.0], [5.0, 5.0]].iter().enumerate().map(|(i, &v)| Keyframe::new(s(i as f64), Value::Vec2(v))).collect::<Vec<_>>();
-        assert_eq!(spatial_tangents(&still, 1), ([0.0; 3], [0.0; 3]));
-        assert_eq!(spatial_tangents(&still[..1], 0), ([0.0; 3], [0.0; 3]));
-    }
-
-    #[test]
-    fn auto_spatial_holds_between_identical_keys() {
-        let path = [(0.0, [0.0, 540.0]), (0.6, [400.0, 540.0]), (4.4, [400.0, 540.0]), (5.0, [0.0, 540.0])];
-        for eased in [false, true] {
-            let keys: Vec<Keyframe> = path
-                .iter()
-                .map(|&(t, v)| {
-                    let k = Keyframe::new(s(t), Value::Vec2(v));
-                    if eased { k.eased() } else { k }
-                })
-                .collect();
-            assert_eq!(spatial_tangents(&keys, 1).1, [0.0; 3]);
-            assert_eq!(spatial_tangents(&keys, 2).0, [0.0; 3]);
-            for t in [0.7, 1.0, 2.5, 4.0, 4.3] {
-                let p = evaluate(&keys, s(t), true).unwrap().as_vec3();
-                assert!((p[0] - 400.0).abs() < 1e-6 && (p[1] - 540.0).abs() < 1e-6, "eased={eased} t={t} p={p:?}");
-            }
-        }
-    }
-
-    #[test]
-    fn set_key_replaces_same_time() {
-        let mut keys = vec![];
-        set_key(&mut keys, Keyframe::new(s(1.0), Value::Scalar(1.0)).eased());
-        set_key(&mut keys, Keyframe::new(s(0.0), Value::Scalar(0.0)));
-        set_key(&mut keys, Keyframe::new(s(1.0), Value::Scalar(5.0)));
-        assert_eq!(keys.len(), 2);
-        assert_eq!(keys[1].value, Value::Scalar(5.0));
-        assert_eq!(keys[1].in_interp, Interp::Bezier);
-    }
-
-    #[test]
-    fn colors_and_paths_interpolate() {
-        let keys = vec![Keyframe::new(s(0.0), Value::Color([0.0, 0.0, 0.0, 1.0])), Keyframe::new(s(1.0), Value::Color([1.0, 0.5, 0.0, 1.0]))];
-        assert_eq!(evaluate(&keys, s(0.5), false).unwrap().as_color(), [0.5, 0.25, 0.0, 1.0]);
-        let a = ShapePath::rect([0.0, 0.0], 10.0, 10.0);
-        let b = ShapePath::rect([0.0, 0.0], 20.0, 20.0);
-        let keys = vec![Keyframe::new(s(0.0), Value::Path(a)), Keyframe::new(s(1.0), Value::Path(b))];
-        let v = evaluate(&keys, s(0.5), false).unwrap();
-        assert_eq!(v.as_path().unwrap().vertices[0], [-7.5, -7.5]);
-    }
-
-    #[test]
-    fn roving_keys_get_constant_speed_times() {
-        let mut keys = vec![
-            Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0])),
-            Keyframe::new(s(0.2), Value::Vec2([300.0, 0.0])),
-            Keyframe::new(s(2.0), Value::Vec2([400.0, 0.0])),
-        ];
-        for k in &mut keys {
-            k.spatial_auto = false;
-        }
-        keys[1].roving = true;
-        assert!(retime_roving(&mut keys, true));
-        // 300 of 400 px → 75 % of the 2 s span.
-        assert!((keys[1].time.seconds() - 1.5).abs() < 1e-6, "{}", keys[1].time.seconds());
-        let v0 = speed(&keys, s(0.5), true);
-        let v1 = speed(&keys, s(1.8), true);
-        assert!((v0 - 200.0).abs() < 1.0 && (v1 - 200.0).abs() < 1.0, "{v0} {v1}");
-        // First/last keys can't rove.
-        keys[0].roving = true;
-        retime_roving(&mut keys, true);
-        assert!(!keys[0].roving);
-    }
-
-    #[test]
-    fn roving_keys_never_share_a_time_with_a_fixed_key() {
-        // Zero-length last segment (issue #532) and zero-length first segment.
-        for xs in [[0.0, 40.0, 120.0, 120.0], [0.0, 0.0, 40.0, 120.0]] {
-            let mut keys: Vec<Keyframe> = xs.iter().enumerate().map(|(i, x)| Keyframe::new(s(i as f64), Value::Vec2([*x, 64.0]))).collect();
-            for k in &mut keys {
-                k.spatial_auto = false;
-            }
-            keys[1].roving = true;
-            keys[2].roving = true;
-            retime_roving(&mut keys, true);
-            assert!(keys.windows(2).all(|w| w[0].time < w[1].time), "{xs:?}: {:?}", keys.iter().map(|k| k.time).collect::<Vec<_>>());
-        }
-    }
-
-    #[test]
-    fn side_ease_reports_linear_and_eased_sides() {
-        let keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)), Keyframe::new(s(2.0), Value::Scalar(100.0)).eased()];
-        let out = side_ease(&keys, 0, 0, false, true).unwrap();
-        assert!((out.speed - 50.0).abs() < 1e-9);
-        let inn = side_ease(&keys, 1, 0, false, false).unwrap();
-        assert_eq!(inn, Ease::EASY);
-        assert!(side_ease(&keys, 0, 0, false, false).is_none());
-    }
-
-    #[test]
-    fn time_reverse_mirrors_keys() {
-        let mut keys =
-            vec![Keyframe::new(s(1.0), Value::Scalar(0.0)).eased(), Keyframe::new(s(2.0), Value::Scalar(5.0)), Keyframe::new(s(4.0), Value::Scalar(10.0))];
-        keys[0].out_interp = Interp::Hold;
-        time_reverse(&mut keys);
-        assert_eq!(keys.iter().map(|k| k.time.seconds().round() as i64).collect::<Vec<_>>(), vec![1, 3, 4]);
-        assert_eq!(keys[0].value, Value::Scalar(10.0));
-        assert_eq!(keys[2].in_interp, Interp::Hold);
-    }
-
-    proptest::proptest! {
-        #[test]
-        fn eased_values_stay_in_range(t in 0.0f64..1.0, i0 in 0.01f64..1.0, i1 in 0.01f64..1.0) {
-            let mut a = Keyframe::new(s(0.0), Value::Scalar(0.0)).eased();
-            let mut b = Keyframe::new(s(1.0), Value::Scalar(10.0)).eased();
-            a.out_ease = vec![Ease { speed: 0.0, influence: i0 }];
-            b.in_ease = vec![Ease { speed: 0.0, influence: i1 }];
-            let v = evaluate(&[a, b], s(t), false).unwrap().as_f64();
-            proptest::prop_assert!((-1e-9..=10.0 + 1e-9).contains(&v));
-        }
-    }
-}
+mod tests;
diff --git a/crates/keyframe/src/tests.rs b/crates/keyframe/src/tests.rs
new file mode 100644
index 000000000..0a31cfc19
--- /dev/null
+++ b/crates/keyframe/src/tests.rs
@@ -0,0 +1,397 @@
+use super::*;
+
+fn s(x: f64) -> Tick {
+    Tick::from_seconds_f64(x)
+}
+
+#[test]
+fn missing_spatial_keys_have_no_tangents_or_length() {
+    let keys = vec![Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0]))];
+    for i in [1, usize::MAX] {
+        assert_eq!(spatial_tangents(&keys, i), ([0.0; 3], [0.0; 3]));
+        assert_eq!(spatial_segment_length(&keys, i), 0.0);
+    }
+    assert_eq!(spatial_tangents(&[], 0), ([0.0; 3], [0.0; 3]));
+    assert_eq!(spatial_segment_length(&[], usize::MAX), 0.0);
+}
+
+#[test]
+fn time_reverse_handles_deserialized_tick_extremes() {
+    // Tick's public serde representation can contain values beyond from_seconds_f64's cap.
+    for (first, last) in [(i64::MIN, i64::MIN + 10), (i64::MAX - 10, i64::MAX), (i64::MIN, i64::MAX)] {
+        let mut keys = vec![Keyframe::new(Tick(first), Value::Scalar(1.0)), Keyframe::new(Tick(last), Value::Scalar(2.0))];
+        time_reverse(&mut keys);
+        assert_eq!(keys[0].time, Tick(first));
+        assert_eq!(keys[0].value, Value::Scalar(2.0));
+        assert_eq!(keys[1].time, Tick(last));
+        assert_eq!(keys[1].value, Value::Scalar(1.0));
+        time_reverse(&mut keys);
+        assert_eq!(keys[0].value, Value::Scalar(1.0));
+    }
+}
+
+#[test]
+fn roving_handles_deserialized_tick_extremes() {
+    let mut keys = vec![
+        Keyframe::new(Tick(i64::MIN), Value::Vec2([0.0, 0.0])),
+        Keyframe::new(Tick(10), Value::Vec2([50.0, 0.0])),
+        Keyframe::new(Tick(i64::MAX), Value::Vec2([100.0, 0.0])),
+    ];
+    for key in &mut keys {
+        key.spatial_auto = false;
+    }
+    keys[1].roving = true;
+    assert!(retime_roving(&mut keys, true));
+    assert_eq!(keys[1].time, Tick::ZERO);
+}
+
+#[test]
+fn replacing_key_preserves_spatial_metadata() {
+    let mut key = Keyframe::new(s(1.0), Value::Vec2([20.0, 30.0]));
+    key.roving = true;
+    key.spatial_continuous = true;
+    let mut keys = vec![key];
+    set_key(&mut keys, Keyframe::new(s(1.0), Value::Vec2([40.0, 50.0])));
+    assert!(keys[0].roving);
+    assert!(keys[0].spatial_continuous);
+    assert_eq!(keys[0].value, Value::Vec2([40.0, 50.0]));
+}
+
+#[test]
+fn temporal_ease_matches_live_ae_with_overlapping_influences() {
+    // Original Rotation probe via AEsync 2.0.4, AE 26.3x87, 2026-10-05.
+    // AE retains each handle's requested influence even when their sum exceeds 100%.
+    for (from, to, out_speed, out_inf, in_speed, in_inf, samples) in [
+        (0.0, 100.0, 0.0, 0.8, 0.0, 0.8, [(0.1, 0.59243939036327), (0.25, 4.76438030608764), (0.4, 18.4284394271562), (0.75, 95.2356196939123)]),
+        (0.0, 100.0, 20.0, 0.8, 80.0, 0.6, [(0.1, 2.25754942621577), (0.25, 6.99841889412931), (0.4, 14.9334636959052), (0.75, 73.8196785378389)]),
+        (100.0, 0.0, -20.0, 0.6, -80.0, 0.8, [(0.1, 97.6395466334594), (0.25, 91.597048571292), (0.4, 74.5367957474338), (0.75, 22.3789127753126)]),
+    ] {
+        let mut a = Keyframe::new(s(0.0), Value::Scalar(from));
+        let mut b = Keyframe::new(s(1.0), Value::Scalar(to));
+        a.out_interp = Interp::Bezier;
+        b.in_interp = Interp::Bezier;
+        a.out_ease = vec![Ease { speed: out_speed, influence: out_inf }];
+        b.in_ease = vec![Ease { speed: in_speed, influence: in_inf }];
+        for (time, expected) in samples {
+            let value = evaluate(&[a.clone(), b.clone()], s(time), false).unwrap().as_f64();
+            assert!((value - expected).abs() < 1e-7, "{time}: {value} != {expected}");
+            let normalized = ease_progress(out_speed / (to - from), out_inf, in_speed / (to - from), in_inf, time);
+            assert!((from + normalized * (to - from) - expected).abs() < 1e-7);
+        }
+    }
+}
+
+#[test]
+fn maximum_influence_resolves_flat_midpoint_time_curve() {
+    for time in [0.5 - 1e-9, 0.5 - 1e-12, 0.5, 0.5 + 1e-12, 0.5 + 1e-9] {
+        // At 100%/100%, x = 0.5 + 4*(u - 0.5)^3 exactly.
+        let u = 0.5 + ((time - 0.5) / 4.0_f64).cbrt();
+        let expected = bez(0.0, 0.0, 1.0, 1.0, u);
+        let actual = ease_progress(0.0, 1.0, 0.0, 1.0, time);
+        assert!((actual - expected).abs() < 1e-10, "{time}: {actual} != {expected}");
+    }
+}
+
+/// M13.15: agents set gradients as plain JSON, not only the tagged form `get` returns.
+#[test]
+fn gradients_coerce_from_plain_json() {
+    let g = Value::Gradient(Gradient::default());
+    let plain = serde_json::json!({"colors": [[0, [0, 0.5, 1, 1]], [1, "#ffff00"]], "opacities": [[0, 1], [1, 0.5]]});
+    let Some(Value::Gradient(a)) = g.coerce_json(&plain) else { panic!("object form") };
+    assert_eq!(a.colors, vec![(0.0, [0.0, 0.5, 1.0, 1.0]), (1.0, [1.0, 1.0, 0.0, 1.0])]);
+    assert_eq!(a.opacities, vec![(0.0, 1.0), (1.0, 0.5)]);
+    let Some(Value::Gradient(b)) = g.coerce_json(&serde_json::json!(["#ff0000", "#00ff00", "#0000ff"])) else { panic!("list form") };
+    assert_eq!(b.colors.iter().map(|c| c.0).collect::<Vec<_>>(), vec![0.0, 0.5, 1.0]);
+    assert_eq!(b.opacities.len(), 3);
+    // The tagged form (what prop.get returns) still round-trips.
+    assert_eq!(g.coerce_json(&g.to_json()), Some(g.clone()));
+    assert_eq!(g.coerce_json(&serde_json::json!(5)), None);
+}
+
+/// #612: the gradient editor samples a new stop from its own track only. `sample` multiplies
+/// in the opacity stops, so feeding its alpha into a colour stop would apply 50% twice (25%).
+#[test]
+fn gradient_tracks_sample_separately() {
+    let g = Gradient { colors: vec![(0.0, [1.0, 0.0, 0.0, 0.8]), (1.0, [0.0, 0.0, 1.0, 0.4])], opacities: vec![(0.0, 0.5), (1.0, 0.5)] };
+    let c = g.color_at(0.5);
+    assert!((c[0] - 0.5).abs() < 1e-6 && (c[2] - 0.5).abs() < 1e-6, "{c:?}");
+    assert!((c[3] - 0.6).abs() < 1e-6, "the colour track's own alpha, without opacity: {c:?}");
+    assert!((g.opacity_at(0.5) - 0.5).abs() < 1e-6);
+    assert!((g.sample(0.5)[3] - 0.3).abs() < 1e-6, "sample still applies opacity once");
+    // A stop added at 50% from the opacity track keeps 50%: sampled again, it is still 50%.
+    let mut with_stop = g.clone();
+    with_stop.opacities.insert(1, (0.5, g.opacity_at(0.5)));
+    assert!((with_stop.opacity_at(0.5) - 0.5).abs() < 1e-6);
+    assert!((with_stop.sample(0.5)[3] - 0.3).abs() < 1e-6, "adding a stop doesn't change the look");
+    // Outside the stops, and with none: the ends hold, and an empty track is opaque white.
+    assert_eq!(g.color_at(-1.0), [1.0, 0.0, 0.0, 0.8]);
+    assert_eq!(g.color_at(2.0), [0.0, 0.0, 1.0, 0.4]);
+    let empty = Gradient { colors: vec![], opacities: vec![] };
+    assert_eq!((empty.color_at(0.3), empty.opacity_at(0.3)), ([1.0; 4], 1.0));
+}
+
+/// #612: the editor saves the typed form, so one colour stop (which the plain JSON parser
+/// rejects) and each stop's RGBA come back exactly.
+#[test]
+fn typed_gradient_round_trips_one_stop_and_rgba() {
+    let one = Value::Gradient(Gradient { colors: vec![(0.25, [0.1, 0.2, 0.3, 0.7])], opacities: vec![(0.0, 1.0), (0.6, 0.35)] });
+    let cur = Value::Gradient(Gradient::default());
+    assert_eq!(cur.coerce_json(&one.to_json()), Some(one.clone()));
+    assert_eq!(cur.coerce_json(&serde_json::json!({"colors": [[0.25, [0.1, 0.2, 0.3, 0.7]]]})), None, "plain JSON needs two colours");
+}
+
+#[test]
+fn linear_and_hold() {
+    let keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)), Keyframe::new(s(2.0), Value::Scalar(100.0))];
+    assert_eq!(evaluate(&keys, s(1.0), false), Some(Value::Scalar(50.0)));
+    assert_eq!(evaluate(&keys, s(-1.0), false), Some(Value::Scalar(0.0)));
+    assert_eq!(evaluate(&keys, s(3.0), false), Some(Value::Scalar(100.0)));
+    let held = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)).hold(), Keyframe::new(s(2.0), Value::Scalar(100.0))];
+    assert_eq!(evaluate(&held, s(1.999), false), Some(Value::Scalar(0.0)));
+}
+
+#[test]
+fn hold_key_keeps_its_incoming_segment_linear() {
+    // Hold on the second key (in and out, as KeyframeInterpolationType.HOLD sets it) holds
+    // what comes after it, not the linear motion into it.
+    let keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)), Keyframe::new(s(2.0), Value::Scalar(100.0)).hold()];
+    assert_eq!(evaluate(&keys, s(0.5), false), Some(Value::Scalar(25.0)));
+    let keys = vec![Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0])), Keyframe::new(s(2.0), Value::Vec2([100.0, 0.0])).hold()];
+    let p = evaluate(&keys, s(0.5), true).unwrap().as_vec2();
+    assert!((p[0] - 25.0).abs() < 0.01, "{p:?}");
+}
+
+#[test]
+fn easy_ease_is_symmetric_and_slow_at_ends() {
+    let keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)).eased(), Keyframe::new(s(1.0), Value::Scalar(100.0)).eased()];
+    let mid = evaluate(&keys, s(0.5), false).unwrap().as_f64();
+    assert!((mid - 50.0).abs() < 1e-6, "{mid}");
+    let early = evaluate(&keys, s(0.1), false).unwrap().as_f64();
+    assert!(early < 10.0 && early > 0.0, "{early}");
+    let v0 = velocity(&keys, s(0.01), false)[0];
+    let vm = velocity(&keys, s(0.5), false)[0];
+    assert!(v0 < vm);
+}
+
+#[test]
+fn bezier_with_linear_speed_matches_linear() {
+    let mut a = Keyframe::new(s(0.0), Value::Scalar(0.0));
+    let mut b = Keyframe::new(s(2.0), Value::Scalar(100.0));
+    a.out_interp = Interp::Bezier;
+    b.in_interp = Interp::Bezier;
+    a.out_ease = vec![Ease { speed: 50.0, influence: 1.0 / 3.0 }];
+    b.in_ease = vec![Ease { speed: 50.0, influence: 1.0 / 3.0 }];
+    let keys = vec![a, b];
+    for i in 0..=20 {
+        let t = i as f64 * 0.1;
+        let v = evaluate(&keys, s(t), false).unwrap().as_f64();
+        assert!((v - 50.0 * t).abs() < 1e-6, "{t} {v}");
+    }
+}
+
+#[test]
+fn spatial_linear_constant_speed() {
+    let keys = vec![Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0])), Keyframe::new(s(1.0), Value::Vec2([300.0, 400.0]))];
+    let p = evaluate(&keys, s(0.5), true).unwrap().as_vec2();
+    assert!((p[0] - 150.0).abs() < 0.5 && (p[1] - 200.0).abs() < 0.5, "{p:?}");
+}
+
+/// #456: along a curved spatial path with linear (constant-speed) keys the speed graph is
+/// flat, not a sawtooth from a piecewise-linear arc-length table.
+#[test]
+fn spatial_curved_path_has_smooth_constant_speed() {
+    let mut a = Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0]));
+    let mut b = Keyframe::new(s(2.0), Value::Vec2([400.0, 0.0]));
+    a.spatial_auto = false;
+    b.spatial_auto = false;
+    a.spatial_out = [50.0, -300.0, 0.0];
+    b.spatial_in = [80.0, 250.0, 0.0];
+    let keys = vec![a, b];
+    let len = spatial_segment_length(&keys, 0);
+    let speeds: Vec<f64> = (1..400).map(|i| speed(&keys, s(i as f64 * 0.005), true)).collect();
+    for v in &speeds {
+        assert!((v - len / 2.0).abs() < 1e-3 * len, "speed {v} vs {}", len / 2.0);
+    }
+}
+
+#[test]
+fn spatial_auto_bezier_passes_through_keys() {
+    let keys = vec![
+        Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0])),
+        Keyframe::new(s(1.0), Value::Vec2([100.0, 100.0])),
+        Keyframe::new(s(2.0), Value::Vec2([200.0, 0.0])),
+    ];
+    let p = evaluate(&keys, s(1.0), true).unwrap().as_vec2();
+    assert_eq!(p, [100.0, 100.0]);
+    // Curved: the midpoint of the first segment lies off the straight line.
+    let m = evaluate(&keys, s(0.5), true).unwrap().as_vec2();
+    assert!((m[0] - m[1]).abs() > 1.0, "{m:?}");
+}
+
+#[test]
+fn straight_auto_bezier_path_is_exact() {
+    // Auto-Bezier ends now have handles along the line; the chord is still hit exactly.
+    let keys = vec![Keyframe::new(s(0.0), Value::Vec2([40.0, 50.0])), Keyframe::new(s(2.0), Value::Vec2([120.0, 50.0]))];
+    assert_eq!(segment_value(&keys, 0, s(1.0), true), Value::Vec2([80.0, 50.0]));
+}
+
+/// #880: a motion path whose arc length overflows (huge coordinates, as the Position field
+/// accepts) or is NaN evaluates without panicking: scrubbing over it crashed the app.
+#[test]
+fn overflowing_or_nan_motion_paths_evaluate() {
+    let paths = [
+        [[-1.7e308, 0.0], [1.7e308, 0.0], [-1.7e308, 5.0]],
+        [[0.0, 0.0], [f64::NAN, 10.0], [20.0, 0.0]],
+        [[f64::INFINITY, 0.0], [0.0, f64::NEG_INFINITY], [20.0, 0.0]],
+    ];
+    for path in paths {
+        let mut keys: Vec<Keyframe> = path.iter().enumerate().map(|(i, &v)| Keyframe::new(s(i as f64 * 2.0), Value::Vec2(v))).collect();
+        for eased in [false, true] {
+            if eased {
+                keys = keys.into_iter().map(Keyframe::eased).collect();
+            }
+            for f in 0..=40 {
+                let t = s(f as f64 * 0.1);
+                assert!(evaluate(&keys, t, true).is_some());
+                let _ = speed(&keys, t, true);
+            }
+        }
+    }
+}
+
+#[test]
+fn spatial_auto_bezier_tangents_follow_after_effects() {
+    // Measured on After Effects 26.3 with original paths (docs/fidelity/README.md): each
+    // auto-Bezier key's out tangent is (next - previous) / 6 and its in tangent the mirror,
+    // whatever the key times. End keys use their one neighbour: (neighbour - key) / 6.
+    let p = [[40.0, 300.0, 0.0], [260.0, 80.0, 20.0], [700.0, 420.0, -40.0], [1100.0, 150.0, 0.0]];
+    let mut keys: Vec<Keyframe> = [0.0, 0.2, 1.5, 1.8].iter().zip(p).map(|(&t, v)| Keyframe::new(s(t), Value::Vec3(v))).collect();
+    let sixth = |a: [f64; 3], b: [f64; 3]| [(b[0] - a[0]) / 6.0, (b[1] - a[1]) / 6.0, (b[2] - a[2]) / 6.0];
+    let neg = |v: [f64; 3]| [-v[0], -v[1], -v[2]];
+    let close = |a: [f64; 3], b: [f64; 3]| a.iter().zip(b).all(|(x, y)| (x - y).abs() < 1e-9);
+    let want = [sixth(p[0], p[1]), sixth(p[0], p[2]), sixth(p[1], p[3]), sixth(p[2], p[3])];
+    for (i, out) in want.into_iter().enumerate() {
+        let (tin, tout) = spatial_tangents(&keys, i);
+        assert!(close(tout, out) && close(tin, neg(out)), "key {i}: {tin:?} {tout:?}");
+    }
+    // Moving a key in time leaves every tangent as it was.
+    keys[1].time = s(1.2);
+    assert!(close(spatial_tangents(&keys, 1).1, sixth(p[0], p[2])));
+    // A key between two coincident neighbours, and a lone key, have none.
+    let still = [[5.0, 5.0], [9.0, 1.0], [5.0, 5.0]].iter().enumerate().map(|(i, &v)| Keyframe::new(s(i as f64), Value::Vec2(v))).collect::<Vec<_>>();
+    assert_eq!(spatial_tangents(&still, 1), ([0.0; 3], [0.0; 3]));
+    assert_eq!(spatial_tangents(&still[..1], 0), ([0.0; 3], [0.0; 3]));
+}
+
+#[test]
+fn auto_spatial_holds_between_identical_keys() {
+    let path = [(0.0, [0.0, 540.0]), (0.6, [400.0, 540.0]), (4.4, [400.0, 540.0]), (5.0, [0.0, 540.0])];
+    for eased in [false, true] {
+        let keys: Vec<Keyframe> = path
+            .iter()
+            .map(|&(t, v)| {
+                let k = Keyframe::new(s(t), Value::Vec2(v));
+                if eased { k.eased() } else { k }
+            })
+            .collect();
+        assert_eq!(spatial_tangents(&keys, 1).1, [0.0; 3]);
+        assert_eq!(spatial_tangents(&keys, 2).0, [0.0; 3]);
+        for t in [0.7, 1.0, 2.5, 4.0, 4.3] {
+            let p = evaluate(&keys, s(t), true).unwrap().as_vec3();
+            assert!((p[0] - 400.0).abs() < 1e-6 && (p[1] - 540.0).abs() < 1e-6, "eased={eased} t={t} p={p:?}");
+        }
+    }
+}
+
+#[test]
+fn set_key_replaces_same_time() {
+    let mut keys = vec![];
+    set_key(&mut keys, Keyframe::new(s(1.0), Value::Scalar(1.0)).eased());
+    set_key(&mut keys, Keyframe::new(s(0.0), Value::Scalar(0.0)));
+    set_key(&mut keys, Keyframe::new(s(1.0), Value::Scalar(5.0)));
+    assert_eq!(keys.len(), 2);
+    assert_eq!(keys[1].value, Value::Scalar(5.0));
+    assert_eq!(keys[1].in_interp, Interp::Bezier);
+}
+
+#[test]
+fn colors_and_paths_interpolate() {
+    let keys = vec![Keyframe::new(s(0.0), Value::Color([0.0, 0.0, 0.0, 1.0])), Keyframe::new(s(1.0), Value::Color([1.0, 0.5, 0.0, 1.0]))];
+    assert_eq!(evaluate(&keys, s(0.5), false).unwrap().as_color(), [0.5, 0.25, 0.0, 1.0]);
+    let a = ShapePath::rect([0.0, 0.0], 10.0, 10.0);
+    let b = ShapePath::rect([0.0, 0.0], 20.0, 20.0);
+    let keys = vec![Keyframe::new(s(0.0), Value::Path(a)), Keyframe::new(s(1.0), Value::Path(b))];
+    let v = evaluate(&keys, s(0.5), false).unwrap();
+    assert_eq!(v.as_path().unwrap().vertices[0], [-7.5, -7.5]);
+}
+
+#[test]
+fn roving_keys_get_constant_speed_times() {
+    let mut keys = vec![
+        Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0])),
+        Keyframe::new(s(0.2), Value::Vec2([300.0, 0.0])),
+        Keyframe::new(s(2.0), Value::Vec2([400.0, 0.0])),
+    ];
+    for k in &mut keys {
+        k.spatial_auto = false;
+    }
+    keys[1].roving = true;
+    assert!(retime_roving(&mut keys, true));
+    // 300 of 400 px → 75 % of the 2 s span.
+    assert!((keys[1].time.seconds() - 1.5).abs() < 1e-6, "{}", keys[1].time.seconds());
+    let v0 = speed(&keys, s(0.5), true);
+    let v1 = speed(&keys, s(1.8), true);
+    assert!((v0 - 200.0).abs() < 1.0 && (v1 - 200.0).abs() < 1.0, "{v0} {v1}");
+    // First/last keys can't rove.
+    keys[0].roving = true;
+    retime_roving(&mut keys, true);
+    assert!(!keys[0].roving);
+}
+
+#[test]
+fn roving_keys_never_share_a_time_with_a_fixed_key() {
+    // Zero-length last segment (issue #532) and zero-length first segment.
+    for xs in [[0.0, 40.0, 120.0, 120.0], [0.0, 0.0, 40.0, 120.0]] {
+        let mut keys: Vec<Keyframe> = xs.iter().enumerate().map(|(i, x)| Keyframe::new(s(i as f64), Value::Vec2([*x, 64.0]))).collect();
+        for k in &mut keys {
+            k.spatial_auto = false;
+        }
+        keys[1].roving = true;
+        keys[2].roving = true;
+        retime_roving(&mut keys, true);
+        assert!(keys.windows(2).all(|w| w[0].time < w[1].time), "{xs:?}: {:?}", keys.iter().map(|k| k.time).collect::<Vec<_>>());
+    }
+}
+
+#[test]
+fn side_ease_reports_linear_and_eased_sides() {
+    let keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)), Keyframe::new(s(2.0), Value::Scalar(100.0)).eased()];
+    let out = side_ease(&keys, 0, 0, false, true).unwrap();
+    assert!((out.speed - 50.0).abs() < 1e-9);
+    let inn = side_ease(&keys, 1, 0, false, false).unwrap();
+    assert_eq!(inn, Ease::EASY);
+    assert!(side_ease(&keys, 0, 0, false, false).is_none());
+}
+
+#[test]
+fn time_reverse_mirrors_keys() {
+    let mut keys =
+        vec![Keyframe::new(s(1.0), Value::Scalar(0.0)).eased(), Keyframe::new(s(2.0), Value::Scalar(5.0)), Keyframe::new(s(4.0), Value::Scalar(10.0))];
+    keys[0].out_interp = Interp::Hold;
+    time_reverse(&mut keys);
+    assert_eq!(keys.iter().map(|k| k.time.seconds().round() as i64).collect::<Vec<_>>(), vec![1, 3, 4]);
+    assert_eq!(keys[0].value, Value::Scalar(10.0));
+    assert_eq!(keys[2].in_interp, Interp::Hold);
+}
+
+proptest::proptest! {
+    #[test]
+    fn eased_values_stay_in_range(t in 0.0f64..1.0, i0 in 0.01f64..1.0, i1 in 0.01f64..1.0) {
+        let mut a = Keyframe::new(s(0.0), Value::Scalar(0.0)).eased();
+        let mut b = Keyframe::new(s(1.0), Value::Scalar(10.0)).eased();
+        a.out_ease = vec![Ease { speed: 0.0, influence: i0 }];
+        b.in_ease = vec![Ease { speed: 0.0, influence: i1 }];
+        let v = evaluate(&[a, b], s(t), false).unwrap().as_f64();
+        proptest::prop_assert!((-1e-9..=10.0 + 1e-9).contains(&v));
+    }
+}
diff --git a/crates/media/src/convert.rs b/crates/media/src/convert.rs
index d483e4b47..9e88ab4dd 100644
--- a/crates/media/src/convert.rs
+++ b/crates/media/src/convert.rs
@@ -103,12 +103,34 @@ pub(crate) fn frame_to_image_in(f: &VideoFrame, op: AlphaOp, mut buf: Vec<Px>) -
         PixelData::Yuv8 { planes, chroma, alpha } => {
             let yuv = Yuv::new(f.color.matrix, f.color.range, 8);
             let amax = 255.0;
-            convert_yuv(&mut img, w, h, *chroma, [&planes[0][..], &planes[1][..], &planes[2][..]], alpha.as_deref().map(|a| &a[..]), amax, &yuv, op);
+            convert_yuv(
+                &mut img,
+                YuvSource {
+                    size: (w, h),
+                    chroma: *chroma,
+                    planes: [&planes[0][..], &planes[1][..], &planes[2][..]],
+                    alpha: alpha.as_deref().map(|a| &a[..]),
+                    amax,
+                },
+                &yuv,
+                op,
+            );
         }
         PixelData::Yuv16 { planes, chroma, bits, alpha } => {
             let yuv = Yuv::new(f.color.matrix, f.color.range, *bits);
             let amax = ((1u32 << *bits) - 1) as f32;
-            convert_yuv(&mut img, w, h, *chroma, [&planes[0][..], &planes[1][..], &planes[2][..]], alpha.as_deref().map(|a| &a[..]), amax, &yuv, op);
+            convert_yuv(
+                &mut img,
+                YuvSource {
+                    size: (w, h),
+                    chroma: *chroma,
+                    planes: [&planes[0][..], &planes[1][..], &planes[2][..]],
+                    alpha: alpha.as_deref().map(|a| &a[..]),
+                    amax,
+                },
+                &yuv,
+                op,
+            );
         }
     }
     img
@@ -280,8 +302,17 @@ fn centred(i: usize, n: usize) -> (usize, usize) {
     (c, o)
 }
 
-#[allow(clippy::too_many_arguments)]
-fn convert_yuv<T: Sample>(img: &mut Image, w: usize, h: usize, chroma: Chroma, planes: [&[T]; 3], alpha: Option<&[T]>, amax: f32, k: &Yuv, op: AlphaOp) {
+/// Borrowed YUV planes and the geometry/range needed to interpret their samples.
+struct YuvSource<'a, T> {
+    size: (usize, usize),
+    chroma: Chroma,
+    planes: [&'a [T]; 3],
+    alpha: Option<&'a [T]>,
+    amax: f32,
+}
+
+fn convert_yuv<T: Sample>(img: &mut Image, source: YuvSource<'_, T>, k: &Yuv, op: AlphaOp) {
+    let YuvSource { size: (w, h), chroma, planes, alpha, amax } = source;
     let (sx, sy) = chroma.shifts();
     let cw = w.div_ceil(1 << sx);
     let ch = h.div_ceil(1 << sy);
diff --git a/crates/model/src/fbx.rs b/crates/model/src/fbx.rs
index 8a3fd9f40..bca387ff2 100644
--- a/crates/model/src/fbx.rs
+++ b/crates/model/src/fbx.rs
@@ -951,5 +951,4 @@ fn parse_within(bytes: &[u8], resolve: &dyn Fn(&str) -> Option<Vec<u8>>, limit:
 }
 
 #[cfg(test)]
-#[path = "fbx_tests.rs"]
 mod tests;
diff --git a/crates/model/src/fbx_tests.rs b/crates/model/src/fbx/tests.rs
similarity index 100%
rename from crates/model/src/fbx_tests.rs
rename to crates/model/src/fbx/tests.rs
diff --git a/crates/opusenc/src/bands.rs b/crates/opusenc/src/bands.rs
index 744de3fe3..cf3c590e8 100644
--- a/crates/opusenc/src/bands.rs
+++ b/crates/opusenc/src/bands.rs
@@ -8,7 +8,8 @@
 
 use crate::range::{BITRES, RangeEncoder, ilog};
 use crate::rate::{Mode, QTHETA_OFFSET, get_pulses};
-use crate::tables::*;
+use crate::tables::EBANDS;
+use crate::{CeltFrame, rate::Allocation};
 
 pub const SPREAD_NORMAL: usize = 2;
 
@@ -55,7 +56,7 @@ fn exp_rotation1_inv(x: &mut [f32], len: usize, stride: usize, c: f32, s: f32) {
     if len <= stride {
         return;
     }
-    if len >= 2 * stride + 1 {
+    if len > 2 * stride {
         for i in 0..=len - 2 * stride - 1 {
             let x1 = x[i];
             let x2 = x[i + stride];
@@ -217,7 +218,7 @@ impl BandEnc<'_, '_> {
             let q = qn as u32;
             let half = q >> 1;
             let ft = (half + 1) * (half + 1);
-            let (fl, fs) = if it <= half { (it * (it + 1) >> 1, it + 1) } else { (ft - ((q + 1 - it) * (q + 2 - it) >> 1), q + 1 - it) };
+            let (fl, fs) = if it <= half { ((it * (it + 1)) >> 1, it + 1) } else { (ft - (((q + 1 - it) * (q + 2 - it)) >> 1), q + 1 - it) };
             self.enc.encode(fl, fl + fs, ft);
             itheta = ((it * 16384) / q) as i32;
         }
@@ -294,26 +295,19 @@ impl BandEnc<'_, '_> {
     }
 }
 
-/// Codes all band shapes (`quant_all_bands`, encoder side, long blocks). `x` holds `c` channels
-/// of `n` normalised MDCT coefficients each.
-#[allow(clippy::too_many_arguments)]
-pub fn quant_all_bands(
-    m: &Mode,
-    start: usize,
-    end: usize,
-    x: &[f32],
-    n_total: usize,
-    c: usize,
-    pulses: &[i32; NB_EBANDS],
-    spread: usize,
-    dual_stereo: bool,
-    intensity: usize,
-    total_bits: i32,
-    mut balance: i32,
-    enc: &mut RangeEncoder,
-    lm: usize,
-    coded_bands: usize,
-) {
+/// Shape-coding controls, independent of the selected band allocation.
+pub struct BandCoding {
+    pub spread: usize,
+    pub total_bits: i32,
+}
+
+/// Codes all band shapes (`quant_all_bands`, encoder side, long blocks). `x` holds
+/// `frame.channels` channels of `n_total` normalised MDCT coefficients each.
+pub fn quant_all_bands(m: &Mode, frame: CeltFrame, x: &[f32], n_total: usize, allocation: &Allocation, coding: BandCoding, enc: &mut RangeEncoder) {
+    let CeltFrame { start, end, channels: c, lm } = frame;
+    let Allocation { pulses, dual_stereo, intensity, coded_bands, balance, .. } = allocation;
+    let (dual_stereo, intensity, coded_bands, mut balance) = (*dual_stereo, *intensity, *coded_bands, *balance);
+    let BandCoding { spread, total_bits } = coding;
     let mm = 1usize << lm;
     debug_assert!(c == 1 || dual_stereo || intensity <= start, "stereo frames are coded as dual stereo");
     let mut ctx = BandEnc { m, enc, i: 0, spread, remaining_bits: 0, pvq_v: Vec::new(), iy: Vec::new(), tmp: Vec::new() };
@@ -362,7 +356,7 @@ mod tests {
             x[i + stride] = c * x2 + s * x1;
             x[i] = c * x1 + ms * x2;
         }
-        if len >= 2 * stride + 1 {
+        if len > 2 * stride {
             for i in (0..=len - 2 * stride - 1).rev() {
                 let x1 = x[i];
                 let x2 = x[i + stride];
diff --git a/crates/opusenc/src/energy.rs b/crates/opusenc/src/energy.rs
index 0057ae33a..1d4b12719 100644
--- a/crates/opusenc/src/energy.rs
+++ b/crates/opusenc/src/energy.rs
@@ -4,9 +4,10 @@
 //! The quantised energies are updated with exactly the decoder's arithmetic so the prediction
 //! state never drifts between encoder and decoder.
 
+use crate::CeltFrame;
 use crate::range::RangeEncoder;
-use crate::rate::MAX_FINE_BITS;
-use crate::tables::*;
+use crate::rate::{Allocation, MAX_FINE_BITS};
+use crate::tables::{BETA_COEF, BETA_INTRA, E_PROB_MODEL, NB_EBANDS, PRED_COEF, SMALL_ENERGY_ICDF};
 
 const LAPLACE_MINP: u32 = 1;
 const LAPLACE_NMIN: u32 = 16;
@@ -56,18 +57,8 @@ pub fn laplace_encode(enc: &mut RangeEncoder, value: i32, mut fs: u32, decay: u3
 /// `quant_coarse_energy` for one prediction mode. `e` holds the target log2 energies (relative
 /// to `E_MEANS`), `old_e` the quantised energies, updated in place. `budget` is the frame size in
 /// bits.
-#[allow(clippy::too_many_arguments)]
-pub fn quant_coarse_energy(
-    start: usize,
-    end: usize,
-    e: &[f32; 2 * NB_EBANDS],
-    old_e: &mut [f32; 2 * NB_EBANDS],
-    intra: bool,
-    enc: &mut RangeEncoder,
-    c: usize,
-    lm: usize,
-    budget: i32,
-) {
+pub fn quant_coarse_energy(frame: CeltFrame, e: &[f32; 2 * NB_EBANDS], old_e: &mut [f32; 2 * NB_EBANDS], intra: bool, enc: &mut RangeEncoder, budget: i32) {
+    let CeltFrame { start, end, channels: c, lm } = frame;
     let prob = &E_PROB_MODEL[lm][intra as usize];
     let (coef, beta) = if intra { (0.0, BETA_INTRA) } else { (PRED_COEF[lm], BETA_COEF[lm]) };
     let mut prev = [0f32; 2];
@@ -111,15 +102,8 @@ pub fn quant_coarse_energy(
 }
 
 /// `quant_fine_energy`: raw bits refining each band's quantised energy.
-pub fn quant_fine_energy(
-    start: usize,
-    end: usize,
-    e: &[f32; 2 * NB_EBANDS],
-    old_e: &mut [f32; 2 * NB_EBANDS],
-    fine_quant: &[i32; NB_EBANDS],
-    enc: &mut RangeEncoder,
-    c: usize,
-) {
+pub fn quant_fine_energy(frame: CeltFrame, e: &[f32; 2 * NB_EBANDS], old_e: &mut [f32; 2 * NB_EBANDS], fine_quant: &[i32; NB_EBANDS], enc: &mut RangeEncoder) {
+    let CeltFrame { start, end, channels: c, .. } = frame;
     for i in start..end {
         let fq = fine_quant[i];
         if fq <= 0 {
@@ -139,18 +123,16 @@ pub fn quant_fine_energy(
 
 /// `quant_energy_finalise`: spends the bits left at the end of the frame on one more bit of
 /// energy resolution per band, in priority order.
-#[allow(clippy::too_many_arguments)]
 pub fn quant_energy_finalise(
-    start: usize,
-    end: usize,
+    frame: CeltFrame,
     e: &[f32; 2 * NB_EBANDS],
     old_e: &mut [f32; 2 * NB_EBANDS],
-    fine_quant: &[i32; NB_EBANDS],
-    fine_priority: &[i32; NB_EBANDS],
+    allocation: &Allocation,
     mut bits_left: i32,
     enc: &mut RangeEncoder,
-    c: usize,
 ) {
+    let CeltFrame { start, end, channels: c, .. } = frame;
+    let Allocation { fine_quant, fine_priority, .. } = allocation;
     for prio in 0..2 {
         let mut i = start;
         while i < end && bits_left >= c as i32 {
diff --git a/crates/opusenc/src/lib.rs b/crates/opusenc/src/lib.rs
index 9cc1f6a51..b4346ebd6 100644
--- a/crates/opusenc/src/lib.rs
+++ b/crates/opusenc/src/lib.rs
@@ -24,8 +24,6 @@
 //! ```
 
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
-// The bit-allocation code mirrors the normative integer arithmetic; keep C-like shift expressions.
-#![allow(clippy::precedence, clippy::int_plus_one)]
 
 mod bands;
 mod energy;
@@ -38,14 +36,23 @@ mod tables;
 
 use std::sync::OnceLock;
 
-use bands::{SPREAD_NORMAL, quant_all_bands};
+use bands::{BandCoding, SPREAD_NORMAL, quant_all_bands};
 use energy::{quant_coarse_energy, quant_energy_finalise, quant_fine_energy};
 use mdct::Mdct;
 use range::{BITRES, RangeEncoder};
-use rate::{Mode as CeltMode, compute_allocation};
+use rate::{AllocationInput, Mode as CeltMode, compute_allocation};
 use resample::Downsampler;
 use silk::SilkEncoder;
-use tables::*;
+use tables::{E_MEANS, EBANDS, NB_EBANDS, OVERLAP, PREEMPH, SPREAD_ICDF, TF_SELECT_TABLE, TRIM_ICDF};
+
+/// Band range, channel count and transform size shared by CELT coding stages.
+#[derive(Clone, Copy)]
+struct CeltFrame {
+    start: usize,
+    end: usize,
+    channels: usize,
+    lm: usize,
+}
 
 /// Samples per channel in one 20 ms frame at 48 kHz.
 const N: usize = 960;
@@ -314,7 +321,7 @@ impl OpusEncoder {
             Mode::Celt => {
                 let (log_e, silence) = self.celt_analysis(pcm);
                 let len = self.frame_bytes;
-                packet.extend_from_slice(&self.encode_celt(RangeEncoder::new(), len, 0, NB_EBANDS, &log_e, silence));
+                packet.extend_from_slice(&self.encode_celt(RangeEncoder::new(), len, 0..NB_EBANDS, &log_e, silence));
             }
             Mode::Silk => {
                 let x = self.silk_input(pcm);
@@ -344,7 +351,7 @@ impl OpusEncoder {
                 }
                 let (log_e, _) = self.celt_analysis(pcm);
                 let end = if self.bandwidth == Bandwidth::SuperWideband { 19 } else { NB_EBANDS };
-                packet.extend_from_slice(&self.encode_celt(enc, len, HYBRID_START_BAND, end, &log_e, false));
+                packet.extend_from_slice(&self.encode_celt(enc, len, HYBRID_START_BAND..end, &log_e, false));
             }
         }
         packet
@@ -406,10 +413,11 @@ impl OpusEncoder {
     /// Codes one CELT frame (RFC 6716 §4.3, in bitstream order) of `len` bytes into `enc`
     /// (which already holds the SILK frame in hybrid mode), coding bands `start..end`, and
     /// finalises the frame.
-    #[allow(clippy::too_many_arguments)]
-    fn encode_celt(&mut self, mut enc: RangeEncoder, len: usize, start: usize, end: usize, log_e: &[f32; 2 * NB_EBANDS], silence: bool) -> Vec<u8> {
+    fn encode_celt(&mut self, mut enc: RangeEncoder, len: usize, bands: std::ops::Range<usize>, log_e: &[f32; 2 * NB_EBANDS], silence: bool) -> Vec<u8> {
         let m = celt_mode();
         let c = self.channels;
+        let frame = CeltFrame { start: bands.start, end: bands.end, channels: c, lm: LM };
+        let CeltFrame { start, end, .. } = frame;
         if c == 1 {
             for i in 0..NB_EBANDS {
                 self.old_band_e[i] = self.old_band_e[i].max(self.old_band_e[NB_EBANDS + i]);
@@ -438,10 +446,10 @@ impl OpusEncoder {
             let mut enc_intra = enc.clone();
             let mut old_intra = self.old_band_e;
             enc_intra.bit_logp(true, 3);
-            quant_coarse_energy(start, end, log_e, &mut old_intra, true, &mut enc_intra, c, LM, total_bits_raw);
+            quant_coarse_energy(frame, log_e, &mut old_intra, true, &mut enc_intra, total_bits_raw);
             enc.bit_logp(false, 3);
             let mut old_inter = self.old_band_e;
-            quant_coarse_energy(start, end, log_e, &mut old_inter, false, &mut enc, c, LM, total_bits_raw);
+            quant_coarse_energy(frame, log_e, &mut old_inter, false, &mut enc, total_bits_raw);
             if enc_intra.tell_frac() < enc.tell_frac() {
                 enc = enc_intra;
                 self.old_band_e = old_intra;
@@ -449,14 +457,14 @@ impl OpusEncoder {
                 self.old_band_e = old_inter;
             }
         } else {
-            quant_coarse_energy(start, end, log_e, &mut self.old_band_e, false, &mut enc, c, LM, total_bits_raw);
+            quant_coarse_energy(frame, log_e, &mut self.old_band_e, false, &mut enc, total_bits_raw);
         }
         // TF resolution: no changes.
         {
             let mut budget = total_bits_raw;
             let mut tell = enc.tell();
             let mut logp = 4;
-            let tf_select_rsv = LM > 0 && tell + logp + 1 <= budget;
+            let tf_select_rsv = LM > 0 && tell + logp < budget;
             budget -= tf_select_rsv as i32;
             for _ in start..end {
                 if tell + logp <= budget {
@@ -488,27 +496,11 @@ impl OpusEncoder {
             enc.icdf(alloc_trim as usize, &TRIM_ICDF, 7);
         }
         let bits = (total_bits_raw << BITRES) - enc.tell_frac() - 1;
-        let alloc = compute_allocation(m, start, end, &offsets, &cap, alloc_trim, bits, c, LM, &mut enc);
-        quant_fine_energy(start, end, log_e, &mut self.old_band_e, &alloc.fine_quant, &mut enc, c);
-        quant_all_bands(
-            m,
-            start,
-            end,
-            &self.freq,
-            N,
-            c,
-            &alloc.pulses,
-            SPREAD_NORMAL,
-            alloc.dual_stereo,
-            alloc.intensity,
-            total_bits_raw << BITRES,
-            alloc.balance,
-            &mut enc,
-            LM,
-            alloc.coded_bands,
-        );
+        let alloc = compute_allocation(m, frame, AllocationInput { offsets: &offsets, cap: &cap, trim: alloc_trim, bits }, &mut enc);
+        quant_fine_energy(frame, log_e, &mut self.old_band_e, &alloc.fine_quant, &mut enc);
+        quant_all_bands(m, frame, &self.freq, N, &alloc, BandCoding { spread: SPREAD_NORMAL, total_bits: total_bits_raw << BITRES }, &mut enc);
         let bits_left = total_bits_raw - enc.tell();
-        quant_energy_finalise(start, end, log_e, &mut self.old_band_e, &alloc.fine_quant, &alloc.fine_priority, bits_left, &mut enc, c);
+        quant_energy_finalise(frame, log_e, &mut self.old_band_e, &alloc, bits_left, &mut enc);
         debug_assert!(enc.tell() <= total_bits_raw, "frame overflow: {} > {}", enc.tell(), total_bits_raw);
         if c == 1 {
             let (a, b) = self.old_band_e.split_at_mut(NB_EBANDS);
diff --git a/crates/opusenc/src/rate.rs b/crates/opusenc/src/rate.rs
index a6ae81f5c..ff6ccae95 100644
--- a/crates/opusenc/src/rate.rs
+++ b/crates/opusenc/src/rate.rs
@@ -4,8 +4,9 @@
 //! spec-derived `filmcraft-opus` decoder (first-party, MIT OR Apache-2.0) step by step; the only
 //! difference is that the encoder *writes* the band-skip, intensity and dual-stereo symbols.
 
+use crate::CeltFrame;
 use crate::range::{BITRES, RangeEncoder, ilog};
-use crate::tables::*;
+use crate::tables::{ALLOC, EBANDS, LOG2_FRAC_TABLE, MAX_LM, NB_EBANDS};
 
 const MAX_PSEUDO: i32 = 40;
 const LOG_MAX_PSEUDO: i32 = 6;
@@ -127,7 +128,7 @@ impl Mode {
         let mut cap = [0i32; NB_EBANDS];
         for (i, cp) in cap.iter_mut().enumerate() {
             let n = (EBANDS[i + 1] - EBANDS[i]) << lm;
-            *cp = (self.caps[NB_EBANDS * (2 * lm + c - 1) + i] as i32 + 64) * c as i32 * n >> 2;
+            *cp = ((self.caps[NB_EBANDS * (2 * lm + c - 1) + i] as i32 + 64) * c as i32 * n) >> 2;
         }
         cap
     }
@@ -200,7 +201,7 @@ fn compute_caps(m: &Mode) -> Vec<u8> {
                 let mut n0 = EBANDS[j + 1] - EBANDS[j];
 
                 let max_bits = if n0 << i == 1 {
-                    c * (1 + MAX_FINE_BITS) << BITRES
+                    (c * (1 + MAX_FINE_BITS)) << BITRES
                 } else {
                     let mut lm0 = 0;
                     if n0 > 2 {
@@ -240,7 +241,7 @@ fn compute_caps(m: &Mode) -> Vec<u8> {
                     let num = mb + ndof * offset;
                     let den = (ndof - 1) << BITRES;
                     let qb = ((num + (den >> 1)) / den).min(MAX_FINE_BITS);
-                    mb += c * qb << BITRES;
+                    mb += (c * qb) << BITRES;
                     mb
                 };
                 let w = c * ((EBANDS[j + 1] - EBANDS[j]) << i);
@@ -263,21 +264,19 @@ pub struct Allocation {
     pub fine_priority: [i32; NB_EBANDS],
 }
 
+/// Per-band limits, boosts and available budget for the allocation search.
+pub struct AllocationInput<'a> {
+    pub offsets: &'a [i32; NB_EBANDS],
+    pub cap: &'a [i32; NB_EBANDS],
+    pub trim: i32,
+    pub bits: i32,
+}
+
 /// `clt_compute_allocation`, encoder side. Stereo frames are always coded as dual (L/R) stereo
 /// with no intensity bands, and no band is skipped voluntarily.
-#[allow(clippy::too_many_arguments)]
-pub fn compute_allocation(
-    m: &Mode,
-    start: usize,
-    end: usize,
-    offsets: &[i32; NB_EBANDS],
-    cap: &[i32; NB_EBANDS],
-    alloc_trim: i32,
-    total: i32,
-    c: usize,
-    lm: usize,
-    enc: &mut RangeEncoder,
-) -> Allocation {
+pub fn compute_allocation(m: &Mode, frame: CeltFrame, input: AllocationInput<'_>, enc: &mut RangeEncoder) -> Allocation {
+    let CeltFrame { start, end, channels: c, lm } = frame;
+    let AllocationInput { offsets, cap, trim: alloc_trim, bits: total } = input;
     let ci = c as i32;
     let lmi = lm as i32;
     let mut total = total.max(0);
@@ -302,8 +301,8 @@ pub fn compute_allocation(
     let mut trim_offset = [0i32; NB_EBANDS];
     for j in start..end {
         let w = EBANDS[j + 1] - EBANDS[j];
-        thresh[j] = (ci << BITRES).max((3 * w << lmi << BITRES) >> 4);
-        trim_offset[j] = ci * w * (alloc_trim - 5 - lmi) * (end as i32 - j as i32 - 1) * (1 << (lmi + BITRES as i32)) >> 6;
+        thresh[j] = (ci << BITRES).max(((3 * w) << lmi << BITRES) >> 4);
+        trim_offset[j] = (ci * w * (alloc_trim - 5 - lmi) * (end as i32 - j as i32 - 1) * (1 << (lmi + BITRES as i32))) >> 6;
         if w << lmi == 1 {
             trim_offset[j] -= ci << BITRES;
         }
@@ -317,7 +316,7 @@ pub fn compute_allocation(
         let mid = (lo + hi) >> 1;
         for j in (start..end).rev() {
             let n = EBANDS[j + 1] - EBANDS[j];
-            let mut bitsj = ci * n * (ALLOC[mid as usize][j] as i32) << lmi >> 2;
+            let mut bitsj = (ci * n * (ALLOC[mid as usize][j] as i32)) << lmi >> 2;
             if bitsj > 0 {
                 bitsj = (bitsj + trim_offset[j]).max(0);
             }
@@ -342,8 +341,8 @@ pub fn compute_allocation(
     lo -= 1;
     for j in start..end {
         let n = EBANDS[j + 1] - EBANDS[j];
-        let mut bits1j = ci * n * (ALLOC[lo as usize][j] as i32) << lmi >> 2;
-        let mut bits2j = if hi >= nb_alloc { cap[j] } else { ci * n * (ALLOC[hi as usize][j] as i32) << lmi >> 2 };
+        let mut bits1j = (ci * n * (ALLOC[lo as usize][j] as i32)) << lmi >> 2;
+        let mut bits2j = if hi >= nb_alloc { cap[j] } else { (ci * n * (ALLOC[hi as usize][j] as i32)) << lmi >> 2 };
         if bits1j > 0 {
             bits1j = (bits1j + trim_offset[j]).max(0);
         }
@@ -361,27 +360,27 @@ pub fn compute_allocation(
         bits1[j] = bits1j;
         bits2[j] = bits2j;
     }
-    interp_bits2pulses(m, start, end, skip_start, &bits1, &bits2, &thresh, cap, total, skip_rsv, intensity_rsv, dual_stereo_rsv, c, lm, enc)
+    let interpolation =
+        AllocationInterpolation { skip_start, bits1: &bits1, bits2: &bits2, thresh: &thresh, cap, total, skip_rsv, intensity_rsv, dual_stereo_rsv };
+    interp_bits2pulses(m, frame, interpolation, enc)
 }
 
-#[allow(clippy::too_many_arguments)]
-fn interp_bits2pulses(
-    m: &Mode,
-    start: usize,
-    end: usize,
+/// Bracketing allocation vectors and signalling reserves for the interpolation stage.
+struct AllocationInterpolation<'a> {
     skip_start: usize,
-    bits1: &[i32; NB_EBANDS],
-    bits2: &[i32; NB_EBANDS],
-    thresh: &[i32; NB_EBANDS],
-    cap: &[i32; NB_EBANDS],
-    mut total: i32,
+    bits1: &'a [i32; NB_EBANDS],
+    bits2: &'a [i32; NB_EBANDS],
+    thresh: &'a [i32; NB_EBANDS],
+    cap: &'a [i32; NB_EBANDS],
+    total: i32,
     skip_rsv: i32,
-    mut intensity_rsv: i32,
-    mut dual_stereo_rsv: i32,
-    c: usize,
-    lm: usize,
-    enc: &mut RangeEncoder,
-) -> Allocation {
+    intensity_rsv: i32,
+    dual_stereo_rsv: i32,
+}
+
+fn interp_bits2pulses(m: &Mode, frame: CeltFrame, interpolation: AllocationInterpolation<'_>, enc: &mut RangeEncoder) -> Allocation {
+    let CeltFrame { start, end, channels: c, lm } = frame;
+    let AllocationInterpolation { skip_start, bits1, bits2, thresh, cap, mut total, skip_rsv, mut intensity_rsv, mut dual_stereo_rsv } = interpolation;
     let ci = c as i32;
     let alloc_floor = ci << BITRES;
     let stereo = (c > 1) as i32;
@@ -393,7 +392,7 @@ fn interp_bits2pulses(
         let mut psum = 0;
         let mut done = false;
         for j in (start..end).rev() {
-            let tmp = bits1[j] + (mid * bits2[j] >> ALLOC_STEPS);
+            let tmp = bits1[j] + ((mid * bits2[j]) >> ALLOC_STEPS);
             if tmp >= thresh[j] || done {
                 done = true;
                 psum += tmp.min(cap[j]);
@@ -411,7 +410,7 @@ fn interp_bits2pulses(
     let mut psum = 0;
     let mut done = false;
     for j in (start..end).rev() {
-        let mut tmp = bits1[j] + (lo * bits2[j] >> ALLOC_STEPS);
+        let mut tmp = bits1[j] + ((lo * bits2[j]) >> ALLOC_STEPS);
         if tmp < thresh[j] && !done {
             tmp = if tmp >= alloc_floor { alloc_floor } else { 0 };
         } else {
@@ -500,9 +499,9 @@ fn interp_bits2pulses(
             if n == 2 {
                 offset += (den << BITRES) >> 2;
             }
-            if bits[j] + offset < den * 2 << BITRES {
+            if bits[j] + offset < (den * 2) << BITRES {
                 offset += nclogn >> 2;
-            } else if bits[j] + offset < den * 3 << BITRES {
+            } else if bits[j] + offset < (den * 3) << BITRES {
                 offset += nclogn >> 3;
             }
             let mut eb = (bits[j] + offset + (den << (BITRES - 1))).max(0);
@@ -513,7 +512,7 @@ fn interp_bits2pulses(
             eb = eb.min(MAX_FINE_BITS);
             ebits[j] = eb;
             fine_priority[j] = (eb * (den << BITRES) >= bits[j] + offset) as i32;
-            bits[j] -= ci * eb << BITRES;
+            bits[j] -= (ci * eb) << BITRES;
         } else {
             excess = (bit - (ci << BITRES)).max(0);
             bits[j] = bit - excess;
@@ -523,7 +522,7 @@ fn interp_bits2pulses(
         if excess > 0 {
             let extra_fine = (excess >> (stereo + BITRES as i32)).min(MAX_FINE_BITS - ebits[j]);
             ebits[j] += extra_fine;
-            let extra_bits = extra_fine * ci << BITRES;
+            let extra_bits = (extra_fine * ci) << BITRES;
             fine_priority[j] = (extra_bits >= excess - balance) as i32;
             excess -= extra_bits;
         }
diff --git a/crates/opusenc/src/silk/mod.rs b/crates/opusenc/src/silk.rs
similarity index 98%
rename from crates/opusenc/src/silk/mod.rs
rename to crates/opusenc/src/silk.rs
index c7a4b8692..2678a96a0 100644
--- a/crates/opusenc/src/silk/mod.rs
+++ b/crates/opusenc/src/silk.rs
@@ -16,8 +16,12 @@ mod pulses;
 #[allow(dead_code)]
 pub(crate) mod tables;
 
-use lpc::*;
-use tables::*;
+use lpc::{MAX_LPC_ORDER, div32_varq, inverse32_varq, nlsf2a, rshift_round, sat16, smlawb, smulwb, smulww};
+use tables::{
+    DELTA_GAIN, GAIN_MSB, LTP_FILTER, LTP_PERIODICITY, LTP_SCALE, LTP_TAPS_0, LTP_TAPS_1, LTP_TAPS_2, MID_ONLY, NLSF_EXT, NLSF_INTERP, NLSF_SEL_NBMB,
+    NLSF_SEL_WB, NLSF_STAGE1, NLSF_STAGE2, PITCH_CONTOUR, PITCH_HIGH, PITCH_LOW, STEREO_PRED_JOINT, STEREO_WEIGHTS_Q13, TYPE_ACTIVE, TYPE_INACTIVE, UNIFORM3,
+    UNIFORM4, UNIFORM5, UNIFORM8,
+};
 
 use crate::range::RangeEncoder;
 
diff --git a/crates/opusenc/src/silk/analysis.rs b/crates/opusenc/src/silk/analysis.rs
index de510433e..439331076 100644
--- a/crates/opusenc/src/silk/analysis.rs
+++ b/crates/opusenc/src/silk/analysis.rs
@@ -1,7 +1,7 @@
 //! Encoder-side signal analysis for SILK (own design): windowed autocorrelation LPC, LPC → NLSF
 //! conversion, open-loop pitch search and LTP codebook search.
 
-use super::tables::*;
+use super::tables::{CB_NB_20, CB_WB_20, LTP_FILTER, LTP_PERIODICITY, LTP_TAPS_0, LTP_TAPS_1, LTP_TAPS_2};
 
 /// Short-term prediction coefficients `a` (prediction `x[n] ≈ Σ a[j] x[n-1-j]`) from the
 /// windowed segment `x`, with a Gaussian lag window and white-noise correction.
diff --git a/crates/opusenc/src/silk/lpc.rs b/crates/opusenc/src/silk/lpc.rs
index 7846d2973..e0f8c107e 100644
--- a/crates/opusenc/src/silk/lpc.rs
+++ b/crates/opusenc/src/silk/lpc.rs
@@ -5,7 +5,10 @@
 //! spec-derived `filmcraft-opus` decoder (MIT OR Apache-2.0): the encoder must reconstruct the
 //! quantised NLSFs and LPC coefficients bit-exactly as the decoder does.
 
-use super::tables::*;
+use super::tables::{
+    COS_Q12, LSF_ORDER_NBMB, LSF_ORDER_WB, NLSF_CB_NBMB, NLSF_CB_WB, NLSF_MIN_SPACING_NBMB, NLSF_MIN_SPACING_WB, NLSF_PRED_NBMB, NLSF_PRED_WB, NLSF_PSEL_NBMB,
+    NLSF_PSEL_WB,
+};
 
 pub const MAX_LPC_ORDER: usize = 16;
 
diff --git a/crates/opusenc/src/silk/nlsf.rs b/crates/opusenc/src/silk/nlsf.rs
index 3f1f17ac6..4695152ff 100644
--- a/crates/opusenc/src/silk/nlsf.rs
+++ b/crates/opusenc/src/silk/nlsf.rs
@@ -3,7 +3,9 @@
 //! dequantisation exactly. The search strategy is our own.
 
 use super::lpc::{MAX_LPC_ORDER, nlsf_decode, smlawb, sqrt_approx};
-use super::tables::*;
+use super::tables::{
+    NLSF_CB_NBMB, NLSF_CB_WB, NLSF_EXT, NLSF_PRED_NBMB, NLSF_PRED_WB, NLSF_PSEL_NBMB, NLSF_PSEL_WB, NLSF_SEL_NBMB, NLSF_SEL_WB, NLSF_STAGE1, NLSF_STAGE2,
+};
 
 /// Number of stage-1 candidates refined with stage 2.
 const SURVIVORS: usize = 8;
diff --git a/crates/opusenc/src/silk/pulses.rs b/crates/opusenc/src/silk/pulses.rs
index f8cda15a9..ba22b5ec5 100644
--- a/crates/opusenc/src/silk/pulses.rs
+++ b/crates/opusenc/src/silk/pulses.rs
@@ -2,7 +2,7 @@
 //! with LSB escapes, the recursive shell code, LSBs and signs, written in exactly the order the
 //! decoder reads them.
 
-use super::tables::*;
+use super::tables::{EXC_LSB, EXC_SIGN, PULSE_COUNT, RATE_LEVEL, SHELL_2, SHELL_4, SHELL_8, SHELL_16};
 use crate::range::RangeEncoder;
 
 /// Largest pulse magnitude the quantiser produces (keeps every 16-sample block codable).
diff --git a/crates/path/src/lib.rs b/crates/path/src/lib.rs
index 5069cb83e..c52b3d262 100644
--- a/crates/path/src/lib.rs
+++ b/crates/path/src/lib.rs
@@ -144,7 +144,20 @@ pub fn ellipse(size: [f64; 2], pos: [f64; 2]) -> BezPath {
 }
 
 /// Polystar: a star (`inner` radius used) or polygon, rotation in degrees, roundness in percent.
-pub fn polystar(star: bool, points: f64, pos: [f64; 2], rotation: f64, inner: f64, outer: f64, inner_round: f64, outer_round: f64) -> BezPath {
+pub struct Polystar {
+    pub star: bool,
+    pub points: f64,
+    pub pos: [f64; 2],
+    pub rotation: f64,
+    pub inner: f64,
+    pub outer: f64,
+    pub inner_round: f64,
+    pub outer_round: f64,
+}
+
+/// Build the path described by the polystar's geometry.
+pub fn polystar(spec: Polystar) -> BezPath {
+    let Polystar { star, points, pos, rotation, inner, outer, inner_round, outer_round } = spec;
     let n = points.max(3.0).round() as usize;
     let verts = if star { n * 2 } else { n };
     let mut path = BezPath::new();
@@ -398,7 +411,7 @@ mod tests {
 
     #[test]
     fn star_has_right_vertex_count() {
-        let p = polystar(true, 5.0, [0.0, 0.0], 0.0, 20.0, 50.0, 0.0, 0.0);
+        let p = polystar(Polystar { star: true, points: 5.0, pos: [0.0, 0.0], rotation: 0.0, inner: 20.0, outer: 50.0, inner_round: 0.0, outer_round: 0.0 });
         let v = from_kurbo(&p);
         assert_eq!(v[0].vertices.len(), 10);
     }
diff --git a/crates/path/src/ops.rs b/crates/path/src/ops.rs
index ec6e18604..3ad94944d 100644
--- a/crates/path/src/ops.rs
+++ b/crates/path/src/ops.rs
@@ -533,12 +533,15 @@ pub struct WiggleParams {
     pub correlation: f64,
     /// Temporal phase in degrees (360° = one wiggle period).
     pub phase_deg: f64,
+    /// Spatial phase in degrees: slides each subpath's pattern of displacements along its points
+    /// (360° = once around the subpath).
+    pub spatial_phase_deg: f64,
     pub seed: f64,
 }
 
 impl Default for WiggleParams {
     fn default() -> Self {
-        WiggleParams { size: 10.0, detail: 10.0, smooth: true, speed: 2.0, correlation: 50.0, phase_deg: 0.0, seed: 0.0 }
+        WiggleParams { size: 10.0, detail: 10.0, smooth: true, speed: 2.0, correlation: 50.0, phase_deg: 0.0, spatial_phase_deg: 0.0, seed: 0.0 }
     }
 }
 
@@ -568,9 +571,16 @@ fn noise(seed: u64, idx: u64, t: f64) -> f64 {
     v.clamp(-1.0, 1.0)
 }
 
+/// Catmull-Rom interpolation between `p1` (f = 0) and `p2` (f = 1).
+fn catmull_rom(p0: f64, p1: f64, p2: f64, p3: f64, f: f64) -> f64 {
+    0.5 * (2.0 * p1 + (-p0 + p2) * f + (2.0 * p0 - 5.0 * p1 + 4.0 * p2 - p3) * f * f + (-p0 + 3.0 * p1 - 3.0 * p2 + p3) * f * f * f)
+}
+
 /// Wiggle Paths: subdivides the paths (`detail` points per segment) and displaces every point by
 /// smooth random noise of up to `size` pixels that evolves over `time_s` seconds at `speed`
-/// wiggles per second. Deterministic for a given seed and time.
+/// wiggles per second. The spatial phase moves each point's own share of the noise along the
+/// subpath, and a fraction of a point is interpolated between its neighbors. Deterministic for a
+/// given seed and time.
 pub fn wiggle(paths: &[BezPath], w: &WiggleParams, time_s: f64) -> Vec<BezPath> {
     if w.size == 0.0 {
         return paths.to_vec();
@@ -580,6 +590,7 @@ pub fn wiggle(paths: &[BezPath], w: &WiggleParams, time_s: f64) -> Vec<BezPath>
     let t = time_s * w.speed + w.phase_deg / 360.0;
     let corr = (w.correlation / 100.0).clamp(0.0, 1.0);
     let shared = Vec2::new(noise(seed, u64::MAX, t), noise(seed, u64::MAX - 1, t));
+    let turns = if w.spatial_phase_deg.is_finite() { (w.spatial_phase_deg / 360.0).rem_euclid(1.0) } else { 0.0 };
     let mut idx: u64 = 0;
     paths
         .iter()
@@ -587,14 +598,28 @@ pub fn wiggle(paths: &[BezPath], w: &WiggleParams, time_s: f64) -> Vec<BezPath>
             let mut out = BezPath::new();
             for sub in subs(p) {
                 let s = resample(&sub, m);
-                let disp: Vec<Vec2> = s
-                    .iter()
-                    .map(|_| {
-                        let own = Vec2::new(noise(seed, idx * 2, t + idx as f64 * 0.37), noise(seed, idx * 2 + 1, t + idx as f64 * 0.61));
-                        idx += 1;
-                        (shared * corr + own * (1.0 - corr)) * w.size
-                    })
-                    .collect();
+                let n = s.len();
+                let first = idx;
+                let own = |j: usize| {
+                    let i = first + j as u64;
+                    Vec2::new(noise(seed, i * 2, t + i as f64 * 0.37), noise(seed, i * 2 + 1, t + i as f64 * 0.61))
+                };
+                let along = |j: usize| {
+                    if turns == 0.0 {
+                        return own(j);
+                    }
+                    let u = (j as f64 + turns * n as f64).rem_euclid(n as f64);
+                    let k = u.floor();
+                    let f = u - k;
+                    let k = k as usize % n;
+                    if f == 0.0 {
+                        return own(k);
+                    }
+                    let (p0, p1, p2, p3) = (own((k + n - 1) % n), own(k), own((k + 1) % n), own((k + 2) % n));
+                    Vec2::new(catmull_rom(p0.x, p1.x, p2.x, p3.x, f).clamp(-1.0, 1.0), catmull_rom(p0.y, p1.y, p2.y, p3.y, f).clamp(-1.0, 1.0))
+                };
+                let disp: Vec<Vec2> = (0..n).map(|j| (shared * corr + along(j) * (1.0 - corr)) * w.size).collect();
+                idx += n as u64;
                 emit(&s, &disp, sub.closed, w.smooth, 1.0 / 3.0, &mut out);
             }
             out
diff --git a/crates/path/src/ops/tests.rs b/crates/path/src/ops/tests.rs
index dbdf213ba..89c009bc4 100644
--- a/crates/path/src/ops/tests.rs
+++ b/crates/path/src/ops/tests.rs
@@ -317,6 +317,38 @@ fn wiggle_full_correlation_translates() {
     assert_eq!(zero[0], s[0]);
 }
 
+/// Spatial Phase moves the pattern of displacements along the path: 360° is once around, and a
+/// whole number of points' worth gives each point the displacement of the point that far ahead.
+#[test]
+fn wiggle_spatial_phase_moves_the_pattern_along_the_path() {
+    let s = [sq(0.0, 0.0, 100.0)];
+    let w = WiggleParams { detail: 3.0, correlation: 0.0, smooth: false, ..Default::default() };
+    // Displacements are proportional to Size: twice the size less once the size.
+    let disp = |w: WiggleParams| -> Vec<Vec2> {
+        let a = on_curve(&wiggle(&s, &w, 0.4)[0]);
+        let b = on_curve(&wiggle(&s, &WiggleParams { size: w.size * 2.0, ..w }, 0.4)[0]);
+        a.iter().zip(&b).map(|(a, b)| *b - *a).take(16).collect()
+    };
+    let d0 = disp(w);
+    let n = d0.len();
+    assert_eq!(n, 16);
+    for k in [1, 5] {
+        let dk = disp(WiggleParams { spatial_phase_deg: 360.0 * k as f64 / n as f64, ..w });
+        for j in 0..n {
+            let e = d0[(j + k) % n];
+            assert!(close(dk[j].x, e.x, 1e-9) && close(dk[j].y, e.y, 1e-9), "{k} ahead, point {j}: {:?} vs {e:?}", dk[j]);
+        }
+    }
+    // Whole turns either way leave the path as it is.
+    let base = wiggle(&s, &w, 0.4);
+    assert_eq!(wiggle(&s, &WiggleParams { spatial_phase_deg: 360.0, ..w }, 0.4), base);
+    assert_eq!(wiggle(&s, &WiggleParams { spatial_phase_deg: -720.0, ..w }, 0.4), base);
+    // Half a point ahead, the displacements change and stay within Size.
+    let half = disp(WiggleParams { spatial_phase_deg: 180.0 / n as f64, ..w });
+    assert!(half.iter().zip(&d0).any(|(h, d)| (*h - *d).hypot() > 1e-3));
+    assert!(half.iter().all(|h| h.x.abs() <= 10.0 + 1e-9 && h.y.abs() <= 10.0 + 1e-9));
+}
+
 // ---------------------------------------------------------------- merge / booleans
 
 fn inclusion_exclusion(a: BezPath, b: BezPath) {
diff --git a/crates/pdf/README.md b/crates/pdf/README.md
index 7389b00c8..20f655611 100644
--- a/crates/pdf/README.md
+++ b/crates/pdf/README.md
@@ -138,7 +138,7 @@ ffmpeg elsewhere) to check the code tables against an independent implementation
 ## Shared parser setup and bounds
 
 The workspace pins `craft-pdf` to `craft-libs` Git revision
-`512b54355cd1418f4e8c56a3fbd7483c3c274bf3`, with `default-features = false` and only the explicit `read`
+`92d392cff132eaf53e13afff77f38b5c11b73aa0`, with `default-features = false` and only the explicit `read`
 feature. This excludes the backend's bundled fonts and Adobe CMaps and preserves EffectCraft's
 font and asset policies. The shared parser does not change the supported drawing operators,
 image codecs, continuously rasterized SVG tree, editable shapes, or EPS interpreter.
diff --git a/crates/pdf/src/font.rs b/crates/pdf/src/font.rs
index 2c27838a2..64b0a1c3a 100644
--- a/crates/pdf/src/font.rs
+++ b/crates/pdf/src/font.rs
@@ -89,7 +89,7 @@ impl OutlinePen for Pen {
 
 /// A bundled stand-in for a font that is not embedded, by its PostScript name.
 fn fallback(base: &str) -> &'static [u8] {
-    use effectcraft_text::fonts::*;
+    use effectcraft_text::fonts::{INTER_BOLD, INTER_ITALIC, INTER_REGULAR, INTER_SEMIBOLD, JETBRAINS_MONO_REGULAR, NOTO_SERIF_REGULAR};
     let b = base.to_ascii_lowercase();
     if b.contains("courier") || b.contains("mono") || b.contains("consol") {
         return JETBRAINS_MONO_REGULAR;
@@ -393,89 +393,10 @@ impl Font {
         }
         // Widths.
         if f.composite {
-            f.default_width = file.get_num(&desc_dict, "DW").unwrap_or(1000.0) / 1000.0;
-            if let Some(w) = file.get(&desc_dict, "W").and_then(Obj::array) {
-                let mut i = 0;
-                while i < w.len() {
-                    let first = file.resolve(&w[i]).num().unwrap_or(0.0) as u32;
-                    match w.get(i + 1).map(|x| file.resolve(x)) {
-                        Some(Obj::Array(list)) => {
-                            for (k, v) in list.iter().enumerate() {
-                                if let Some(cid) = first.checked_add(k as u32) {
-                                    f.cid_widths.insert(cid, file.resolve(v).num().unwrap_or(0.0) / 1000.0);
-                                }
-                            }
-                            i += 2;
-                        }
-                        Some(Obj::Num(last)) => {
-                            let wv = w.get(i + 2).and_then(|x| file.resolve(x).num()).unwrap_or(0.0) / 1000.0;
-                            for c in first..=(*last as u32).min(first.saturating_add(65535)) {
-                                f.cid_widths.insert(c, wv);
-                            }
-                            i += 3;
-                        }
-                        _ => break,
-                    }
-                }
-            }
-            // Vertical metrics (§9.7.4.3): /DW2 [vy w1y] and /W2 entries
-            // `c [w1y vx vy …]` or `cfirst clast w1y vx vy`.
-            let dw2 = file.get(&desc_dict, "DW2").map(|x| file.nums(x)).unwrap_or_default();
-            if dw2.len() == 2 {
-                f.dw2 = (dw2[0] / 1000.0, dw2[1] / 1000.0);
-            }
-            if let Some(w) = file.get(&desc_dict, "W2").and_then(Obj::array) {
-                let num = |i: usize| w.get(i).and_then(|x| file.resolve(x).num());
-                let mut i = 0;
-                while i < w.len() {
-                    let Some(first) = num(i) else { break };
-                    let first = first.max(0.0) as u32;
-                    match w.get(i + 1).map(|x| file.resolve(x)) {
-                        Some(Obj::Array(list)) => {
-                            let v: Vec<f64> = list.iter().filter_map(|x| file.resolve(x).num()).collect();
-                            for (k, t) in v.as_chunks::<3>().0.iter().enumerate() {
-                                if let Some(cid) = first.checked_add(k as u32) {
-                                    f.cid_vmetrics.insert(cid, (t[0] / 1000.0, t[1] / 1000.0, t[2] / 1000.0));
-                                }
-                            }
-                            i += 2;
-                        }
-                        Some(Obj::Num(last)) => {
-                            let (Some(w1), Some(vx), Some(vy)) = (num(i + 2), num(i + 3), num(i + 4)) else { break };
-                            for c in first..=(last.max(0.0) as u32).min(first.saturating_add(65535)) {
-                                f.cid_vmetrics.insert(c, (w1 / 1000.0, vx / 1000.0, vy / 1000.0));
-                            }
-                            i += 5;
-                        }
-                        _ => break,
-                    }
-                }
-            }
+            f.load_cid_widths(file, &desc_dict);
+            f.load_vertical_metrics(file, &desc_dict);
             f.has_widths = true;
-            // Encoding CMap.
-            match file.get(d, "Encoding") {
-                Some(Obj::Name(n)) => {
-                    f.vertical = n.ends_with("-V");
-                    if !n.starts_with("Identity") {
-                        skipped.push(format!("CMap {n}"));
-                    }
-                }
-                Some(Obj::Stream(sd, raw)) => {
-                    if let Some(data) = decode_stream(file, sd, raw) {
-                        let cm = parse_cmap(&data);
-                        f.vertical = cm.wmode || file.get_num(sd, "WMode") == Some(1.0);
-                        f.codespace = cm.codespace;
-                        f.cid_ranges = cm.cids;
-                    }
-                }
-                _ => {}
-            }
-            match file.get(&desc_dict, "CIDToGIDMap") {
-                Some(Obj::Stream(sd, raw)) => {
-                    f.cid_to_gid = decode_stream(file, sd, raw).map(|b| b.as_chunks::<2>().0.iter().map(|c| u16::from_be_bytes([c[0], c[1]])).collect());
-                }
-                _ => f.cid_to_gid = None,
-            }
+            f.load_cid_encoding(file, d, &desc_dict, skipped);
         } else {
             f.first_char = file.get_num(d, "FirstChar").unwrap_or(0.0) as u32;
             if let Some(w) = file.get(d, "Widths") {
@@ -486,16 +407,113 @@ impl Font {
                 f.default_width = file.get_num(fd, "MissingWidth").unwrap_or(0.0);
             }
         }
+        f.load_program(file, d, fd.as_ref(), &subtype, skipped);
+        f.load_simple_encoding(file, d);
+        f
+    }
+
+    fn load_cid_widths(&mut self, file: &File, desc_dict: &Dict) {
+        self.default_width = file.get_num(desc_dict, "DW").unwrap_or(1000.0) / 1000.0;
+        if let Some(w) = file.get(desc_dict, "W").and_then(Obj::array) {
+            let mut i = 0;
+            while i < w.len() {
+                let first = file.resolve(&w[i]).num().unwrap_or(0.0) as u32;
+                match w.get(i + 1).map(|x| file.resolve(x)) {
+                    Some(Obj::Array(list)) => {
+                        for (k, v) in list.iter().enumerate() {
+                            if let Some(cid) = first.checked_add(k as u32) {
+                                self.cid_widths.insert(cid, file.resolve(v).num().unwrap_or(0.0) / 1000.0);
+                            }
+                        }
+                        i += 2;
+                    }
+                    Some(Obj::Num(last)) => {
+                        let wv = w.get(i + 2).and_then(|x| file.resolve(x).num()).unwrap_or(0.0) / 1000.0;
+                        for c in first..=(*last as u32).min(first.saturating_add(65535)) {
+                            self.cid_widths.insert(c, wv);
+                        }
+                        i += 3;
+                    }
+                    _ => break,
+                }
+            }
+        }
+    }
+
+    fn load_vertical_metrics(&mut self, file: &File, desc_dict: &Dict) {
+        // Vertical metrics (§9.7.4.3): /DW2 [vy w1y] and /W2 entries
+        // `c [w1y vx vy …]` or `cfirst clast w1y vx vy`.
+        let dw2 = file.get(desc_dict, "DW2").map(|x| file.nums(x)).unwrap_or_default();
+        if dw2.len() == 2 {
+            self.dw2 = (dw2[0] / 1000.0, dw2[1] / 1000.0);
+        }
+        if let Some(w) = file.get(desc_dict, "W2").and_then(Obj::array) {
+            let num = |i: usize| w.get(i).and_then(|x| file.resolve(x).num());
+            let mut i = 0;
+            while i < w.len() {
+                let Some(first) = num(i) else { break };
+                let first = first.max(0.0) as u32;
+                match w.get(i + 1).map(|x| file.resolve(x)) {
+                    Some(Obj::Array(list)) => {
+                        let v: Vec<f64> = list.iter().filter_map(|x| file.resolve(x).num()).collect();
+                        for (k, t) in v.as_chunks::<3>().0.iter().enumerate() {
+                            if let Some(cid) = first.checked_add(k as u32) {
+                                self.cid_vmetrics.insert(cid, (t[0] / 1000.0, t[1] / 1000.0, t[2] / 1000.0));
+                            }
+                        }
+                        i += 2;
+                    }
+                    Some(Obj::Num(last)) => {
+                        let (Some(w1), Some(vx), Some(vy)) = (num(i + 2), num(i + 3), num(i + 4)) else { break };
+                        for c in first..=(last.max(0.0) as u32).min(first.saturating_add(65535)) {
+                            self.cid_vmetrics.insert(c, (w1 / 1000.0, vx / 1000.0, vy / 1000.0));
+                        }
+                        i += 5;
+                    }
+                    _ => break,
+                }
+            }
+        }
+    }
+
+    fn load_cid_encoding(&mut self, file: &File, d: &Dict, desc_dict: &Dict, skipped: &mut Vec<String>) {
+        // Encoding CMap.
+        match file.get(d, "Encoding") {
+            Some(Obj::Name(n)) => {
+                self.vertical = n.ends_with("-V");
+                if !n.starts_with("Identity") {
+                    skipped.push(format!("CMap {n}"));
+                }
+            }
+            Some(Obj::Stream(sd, raw)) => {
+                if let Some(data) = decode_stream(file, sd, raw) {
+                    let cm = parse_cmap(&data);
+                    self.vertical = cm.wmode || file.get_num(sd, "WMode") == Some(1.0);
+                    self.codespace = cm.codespace;
+                    self.cid_ranges = cm.cids;
+                }
+            }
+            _ => {}
+        }
+        match file.get(desc_dict, "CIDToGIDMap") {
+            Some(Obj::Stream(sd, raw)) => {
+                self.cid_to_gid = decode_stream(file, sd, raw).map(|b| b.as_chunks::<2>().0.iter().map(|c| u16::from_be_bytes([c[0], c[1]])).collect());
+            }
+            _ => self.cid_to_gid = None,
+        }
+    }
+
+    fn load_program(&mut self, file: &File, d: &Dict, fd: Option<&Dict>, subtype: &str, skipped: &mut Vec<String>) {
         // The program.
         let font_file = |key: &str| -> Option<(Dict, Vec<u8>)> {
-            let fd = fd.as_ref()?;
+            let fd = fd?;
             match file.get(fd, key) {
                 Some(Obj::Stream(sd, raw)) => Some((sd.clone(), decode_stream(file, sd, raw)?)),
                 _ => None,
             }
         };
         if subtype == "Type3" {
-            f.matrix = file
+            self.matrix = file
                 .get(d, "FontMatrix")
                 .map(|m| file.nums(m))
                 .filter(|m| m.len() == 6)
@@ -511,76 +529,78 @@ impl Font {
                     }
                 }
             }
-            f.program = Program::Type3 { procs, resources: file.get_dict(d, "Resources").cloned() };
+            self.program = Program::Type3 { procs, resources: file.get_dict(d, "Resources").cloned() };
             // Type 3 widths are in glyph space.
-            let m = f.matrix.as_coeffs()[0];
-            for w in &mut f.widths {
+            let m = self.matrix.as_coeffs()[0];
+            for w in &mut self.widths {
                 *w *= m * 1000.0;
             }
         } else if let Some((_, data)) = font_file("FontFile2") {
-            f.program = Program::TrueType(Arc::new(data));
+            self.program = Program::TrueType(Arc::new(data));
         } else if let Some((sd, data)) = font_file("FontFile3") {
             match file.get(&sd, "Subtype").and_then(Obj::name) {
                 Some("OpenType") => {
                     // An OpenType wrapper: TrueType outlines through skrifa, CFF through ours.
                     let cff = FontRef::new(&data).ok().and_then(|fr| fr.table_data(skrifa::Tag::new(b"CFF ")).map(|t| t.as_bytes().to_vec()));
                     match cff.and_then(|c| Cff::parse(&c)) {
-                        Some(c) => f.program = Program::Cff(Box::new(c)),
-                        None => f.program = Program::TrueType(Arc::new(data)),
+                        Some(c) => self.program = Program::Cff(Box::new(c)),
+                        None => self.program = Program::TrueType(Arc::new(data)),
                     }
                 }
                 _ => match Cff::parse(&data) {
-                    Some(c) => f.program = Program::Cff(Box::new(c)),
+                    Some(c) => self.program = Program::Cff(Box::new(c)),
                     None => skipped.push("font program (CFF)".into()),
                 },
             }
         } else if let Some((_, data)) = font_file("FontFile") {
             match Type1::parse(&data) {
-                Some(t) => f.program = Program::Type1(Box::new(t)),
+                Some(t) => self.program = Program::Type1(Box::new(t)),
                 None => skipped.push("font program (Type 1)".into()),
             }
         } else {
-            f.program = Program::Fallback(fallback(&base_name));
+            self.program = Program::Fallback(fallback(&self.base_name));
         }
-        if let Program::Cff(c) = &f.program {
+        if let Program::Cff(c) = &self.program {
             let m = c.font_matrix;
-            f.matrix = Affine::new(m);
+            self.matrix = Affine::new(m);
         }
-        if let Program::Type1(t) = &f.program
+        if let Program::Type1(t) = &self.program
             && let Some(m) = t.font_matrix
         {
-            f.matrix = Affine::new(m);
+            self.matrix = Affine::new(m);
         }
+    }
+
+    fn load_simple_encoding(&mut self, file: &File, d: &Dict) {
         // Simple-font encoding: base encoding, built-in encoding, Differences.
-        if !f.composite {
+        if !self.composite {
             let enc = file.get(d, "Encoding").map(|e| file.resolve(e));
             let base = match enc {
                 Some(Obj::Name(n)) => Base::from_name(n),
                 Some(Obj::Dict(e)) => file.get(e, "BaseEncoding").and_then(Obj::name).and_then(Base::from_name),
                 _ => None,
             };
-            let builtin: Option<Vec<Option<String>>> = match &f.program {
+            let builtin: Option<Vec<Option<String>>> = match &self.program {
                 Program::Type1(t) if !t.encoding.is_empty() => Some((0..256).map(|c| t.encoding.get(&(c as u8)).cloned()).collect()),
                 _ => None,
             };
-            let fallback_base = if f.symbolic { None } else { Some(Base::Standard) };
+            let fallback_base = if self.symbolic { None } else { Some(Base::Standard) };
             for c in 0..256usize {
-                f.names[c] = match (base, &builtin) {
+                self.names[c] = match (base, &builtin) {
                     (Some(b), _) => b.name(c as u8),
                     (None, Some(bi)) => bi[c].clone(),
-                    (None, None) => match &f.program {
+                    (None, None) => match &self.program {
                         // TrueType symbolic fonts map codes directly; others use Standard.
-                        Program::TrueType(_) if f.symbolic => None,
-                        Program::Fallback(_) if base_name.contains("Symbol") || base_name.contains("Dingbats") => None,
+                        Program::TrueType(_) if self.symbolic => None,
+                        Program::Fallback(_) if self.base_name.contains("Symbol") || self.base_name.contains("Dingbats") => None,
                         _ => fallback_base.or(Some(Base::Standard)).and_then(|b| b.name(c as u8)),
                     },
                 };
             }
             if let Some(Obj::Dict(e)) = enc {
-                differences(file, e, &mut f.names);
+                differences(file, e, &mut self.names);
             }
         }
-        f
     }
 
     /// Split a string into (code, byte length) pairs.
diff --git a/crates/pdf/src/lib.rs b/crates/pdf/src/lib.rs
index 7c766559f..567dca9c0 100644
--- a/crates/pdf/src/lib.rs
+++ b/crates/pdf/src/lib.rs
@@ -218,11 +218,3 @@ pub fn layer_doc_with_sizes(doc: &Doc, index: usize, retain: bool) -> (Doc, [f64
 
 #[cfg(test)]
 mod tests;
-#[cfg(test)]
-mod tests_groups;
-#[cfg(test)]
-mod tests_import;
-#[cfg(test)]
-mod tests_reader;
-#[cfg(test)]
-mod tests_shading;
diff --git a/crates/pdf/src/ps.rs b/crates/pdf/src/ps.rs
index dd7350754..3d734e46c 100644
--- a/crates/pdf/src/ps.rs
+++ b/crates/pdf/src/ps.rs
@@ -18,296 +18,16 @@ use crate::build::{Builder, MAX_PATH};
 use crate::font::Font;
 use crate::object::{ascii85, is_white, parse_num};
 
-type DictRef = Rc<RefCell<HashMap<String, V>>>;
+mod builtin;
+mod eps;
+mod exec;
+mod paths;
+mod scanner;
+mod text;
+mod value;
 
-#[derive(Clone)]
-enum V {
-    Num(f64),
-    Bool(bool),
-    /// An executable name.
-    Name(Rc<str>),
-    /// A literal name (`/name`).
-    Lit(Rc<str>),
-    /// A built-in operator, as `load` returns it for a name no dictionary defines.
-    Op(Rc<str>),
-    Str(Rc<RefCell<Vec<u8>>>),
-    Proc(Rc<Vec<V>>),
-    Array(Rc<RefCell<Vec<V>>>),
-    Dict(DictRef),
-    Mark,
-    Null,
-    /// `currentfile`.
-    File,
-}
-
-impl V {
-    fn num(&self) -> Option<f64> {
-        match self {
-            V::Num(n) => Some(*n),
-            _ => None,
-        }
-    }
-    fn key(&self) -> String {
-        match self {
-            V::Name(n) | V::Lit(n) | V::Op(n) => n.to_string(),
-            V::Str(s) => String::from_utf8_lossy(&s.borrow()).into_owned(),
-            V::Num(n) => format!("{n}"),
-            V::Bool(b) => format!("{b}"),
-            _ => String::new(),
-        }
-    }
-    fn items(&self) -> Option<Vec<V>> {
-        match self {
-            V::Array(a) => Some(a.borrow().clone()),
-            V::Proc(p) => Some(p.as_ref().clone()),
-            _ => None,
-        }
-    }
-}
-
-enum Flow {
-    Exit,
-    Stop,
-    Quit,
-}
-
-#[derive(Clone)]
-struct GState {
-    ctm: Affine,
-    color: [f64; 3],
-    lw: f64,
-    cap: Cap,
-    join: Join,
-    miter: f64,
-    dash: Option<(Vec<f64>, f64)>,
-    path: BezPath,
-    cur: Option<Point>,
-    start: Option<Point>,
-    depth: usize,
-    /// The current font dictionary.
-    font: Option<DictRef>,
-}
-
-/// Source tokenizer (the data source for `currentfile`).
-struct Src<'a> {
-    d: &'a [u8],
-    pos: usize,
-}
-
-impl Src<'_> {
-    fn skip_ws(&mut self) {
-        while self.pos < self.d.len() {
-            let c = self.d[self.pos];
-            if is_white(c) {
-                self.pos += 1;
-            } else if c == b'%' {
-                let s = self.pos;
-                while self.pos < self.d.len() && !matches!(self.d[self.pos], b'\n' | b'\r') {
-                    self.pos += 1;
-                }
-                // DSC: skip embedded binary / data sections.
-                let line = &self.d[s..self.pos];
-                if line.starts_with(b"%%BeginData:") || line.starts_with(b"%%BeginBinary:") || line.starts_with(b"%%BeginPreview") {
-                    let end: &[u8] = if line.starts_with(b"%%BeginData:") {
-                        b"%%EndData"
-                    } else if line.starts_with(b"%%BeginBinary:") {
-                        b"%%EndBinary"
-                    } else {
-                        b"%%EndPreview"
-                    };
-                    match self.d[self.pos..].windows(end.len()).position(|w| w == end) {
-                        Some(p) => self.pos += p,
-                        None => self.pos = self.d.len(),
-                    }
-                }
-            } else {
-                break;
-            }
-        }
-    }
-
-    fn word(&mut self) -> &[u8] {
-        let s = self.pos;
-        while self.pos < self.d.len() {
-            let c = self.d[self.pos];
-            if is_white(c) || matches!(c, b'(' | b')' | b'<' | b'>' | b'[' | b']' | b'{' | b'}' | b'/' | b'%') {
-                break;
-            }
-            self.pos += 1;
-        }
-        &self.d[s..self.pos]
-    }
-
-    /// The next token; `{ … }` comes back as a whole procedure.
-    fn token(&mut self, depth: usize) -> Option<V> {
-        self.skip_ws();
-        let c = *self.d.get(self.pos)?;
-        Some(match c {
-            b'{' => {
-                self.pos += 1;
-                let mut body = vec![];
-                loop {
-                    self.skip_ws();
-                    match self.d.get(self.pos) {
-                        None => break,
-                        Some(b'}') => {
-                            self.pos += 1;
-                            break;
-                        }
-                        _ => {
-                            if depth > 100 {
-                                return None;
-                            }
-                            match self.token(depth + 1) {
-                                Some(t) => body.push(t),
-                                None => break,
-                            }
-                        }
-                    }
-                }
-                V::Proc(Rc::new(body))
-            }
-            b'}' => {
-                self.pos += 1;
-                V::Null
-            }
-            b'/' => {
-                self.pos += 1;
-                let imm = self.d.get(self.pos) == Some(&b'/');
-                if imm {
-                    self.pos += 1;
-                }
-                let w = String::from_utf8_lossy(self.word()).into_owned();
-                // `//name` (immediately evaluated) is treated like a plain name.
-                if imm { V::Name(w.into()) } else { V::Lit(w.into()) }
-            }
-            b'(' => {
-                self.pos += 1;
-                let mut out = vec![];
-                let mut depth = 1;
-                while self.pos < self.d.len() {
-                    let c = self.d[self.pos];
-                    self.pos += 1;
-                    match c {
-                        b'\\' => {
-                            let e = self.d.get(self.pos).copied().unwrap_or(b'\\');
-                            self.pos += 1;
-                            match e {
-                                b'n' => out.push(b'\n'),
-                                b'r' => out.push(b'\r'),
-                                b't' => out.push(b'\t'),
-                                b'0'..=b'7' => {
-                                    let mut v = (e - b'0') as u32;
-                                    for _ in 0..2 {
-                                        match self.d.get(self.pos) {
-                                            Some(d @ b'0'..=b'7') => {
-                                                v = v * 8 + (d - b'0') as u32;
-                                                self.pos += 1;
-                                            }
-                                            _ => break,
-                                        }
-                                    }
-                                    out.push(v as u8);
-                                }
-                                b'\n' | b'\r' => {}
-                                o => out.push(o),
-                            }
-                        }
-                        b'(' => {
-                            depth += 1;
-                            out.push(c);
-                        }
-                        b')' => {
-                            depth -= 1;
-                            if depth == 0 {
-                                break;
-                            }
-                            out.push(c);
-                        }
-                        _ => out.push(c),
-                    }
-                }
-                V::Str(Rc::new(RefCell::new(out)))
-            }
-            b'<' if self.d.get(self.pos + 1) == Some(&b'<') => {
-                self.pos += 2;
-                V::Name("<<".into())
-            }
-            b'>' if self.d.get(self.pos + 1) == Some(&b'>') => {
-                self.pos += 2;
-                V::Name(">>".into())
-            }
-            b'<' if self.d.get(self.pos + 1) == Some(&b'~') => {
-                let s = self.pos;
-                while self.pos + 1 < self.d.len() && !(self.d[self.pos] == b'~' && self.d[self.pos + 1] == b'>') {
-                    self.pos += 1;
-                }
-                self.pos = (self.pos + 2).min(self.d.len());
-                V::Str(Rc::new(RefCell::new(ascii85(&self.d[s..self.pos]))))
-            }
-            b'<' => {
-                self.pos += 1;
-                let mut hex = vec![];
-                while self.pos < self.d.len() && self.d[self.pos] != b'>' {
-                    if self.d[self.pos].is_ascii_hexdigit() {
-                        hex.push(self.d[self.pos]);
-                    }
-                    self.pos += 1;
-                }
-                self.pos += 1;
-                if hex.len() % 2 == 1 {
-                    hex.push(b'0');
-                }
-                let h = |c: u8| (c as char).to_digit(16).unwrap_or(0) as u8;
-                V::Str(Rc::new(RefCell::new(hex.chunks(2).map(|p| (h(p[0]) << 4) | h(p[1])).collect())))
-            }
-            b'[' | b']' => {
-                self.pos += 1;
-                V::Name(if c == b'[' { "[" } else { "]" }.into())
-            }
-            b')' | b'>' => {
-                self.pos += 1;
-                V::Null
-            }
-            _ => {
-                let w = self.word();
-                if w.is_empty() {
-                    self.pos += 1;
-                    return Some(V::Null);
-                }
-                match parse_num(w) {
-                    Some(n) => V::Num(n),
-                    None => {
-                        // Radix numbers (16#FF).
-                        let s = String::from_utf8_lossy(w).into_owned();
-                        match s.split_once('#').and_then(|(r, v)| i64::from_str_radix(v, r.parse::<u32>().ok().filter(|r| (2..=36).contains(r))?).ok()) {
-                            Some(n) => V::Num(n as f64),
-                            None => V::Name(s.into()),
-                        }
-                    }
-                }
-            }
-        })
-    }
-
-    /// Step over inline image data that follows an `image` operator reading `currentfile`.
-    fn skip_image_data(&mut self) {
-        self.skip_ws();
-        if self.d[self.pos..].starts_with(b"<~") || self.d.get(self.pos).is_some_and(|c| (b'!'..=b'u').contains(c) && !c.is_ascii_hexdigit()) {
-            match self.d[self.pos..].windows(2).position(|w| w == b"~>") {
-                Some(p) => self.pos += p + 2,
-                None => self.pos = self.d.len(),
-            }
-            return;
-        }
-        while self.pos < self.d.len() && (self.d[self.pos].is_ascii_hexdigit() || is_white(self.d[self.pos])) {
-            self.pos += 1;
-        }
-        if self.d.get(self.pos) == Some(&b'>') {
-            self.pos += 1;
-        }
-    }
-}
+pub use eps::eps_parts;
+use value::{DictRef, GState, V};
 
 pub(crate) struct Interp {
     pub b: Builder,
@@ -327,1712 +47,3 @@ pub(crate) struct Interp {
     page: [f64; 4],
     pub unknown: Vec<String>,
 }
-
-fn new_dict() -> DictRef {
-    Rc::new(RefCell::new(HashMap::new()))
-}
-
-fn array(v: Vec<V>) -> V {
-    V::Array(Rc::new(RefCell::new(v)))
-}
-
-fn matrix_of(v: &V) -> Option<Affine> {
-    let a: Vec<f64> = v.items()?.iter().filter_map(V::num).collect();
-    (a.len() == 6).then(|| Affine::new([a[0], a[1], a[2], a[3], a[4], a[5]]))
-}
-
-fn matrix_val(m: Affine) -> V {
-    array(m.as_coeffs().iter().map(|c| V::Num(*c)).collect())
-}
-
-/// The angle from `a` counterclockwise to `b` (degrees, 0 to 360), worked out from what is left
-/// of each after whole turns.
-fn ccw_turn(a: f64, b: f64) -> f64 {
-    (b % 360.0 - a % 360.0).rem_euclid(360.0)
-}
-
-/// The most turns one `arc` or `arcn` draws.
-const MAX_ARC_TURNS: f64 = 1024.0;
-
-/// The deepest procedure nesting run (deeper recursion stops the program).
-const MAX_CALL_DEPTH: usize = 256;
-
-impl Interp {
-    pub fn new(page: [f64; 4]) -> Interp {
-        Interp {
-            b: Builder::new(),
-            st: vec![],
-            dicts: vec![new_dict()],
-            gs: GState {
-                ctm: Affine::IDENTITY,
-                color: [0.0; 3],
-                lw: 1.0,
-                cap: Cap::Butt,
-                join: Join::Miter,
-                miter: 10.0,
-                dash: None,
-                path: BezPath::new(),
-                cur: None,
-                start: None,
-                depth: 1,
-                font: None,
-            },
-            saved: vec![],
-            budget: 8_000_000,
-            calls: 0,
-            font_dir: HashMap::new(),
-            embedded: HashMap::new(),
-            font_cache: HashMap::new(),
-            page,
-            unknown: vec![],
-        }
-    }
-
-    pub fn run(&mut self, data: &[u8]) {
-        self.embedded = embedded_fonts(data);
-        let mut src = Src { d: data, pos: 0 };
-        while let Some(t) = src.token(0) {
-            if let Err(Flow::Quit) = self.exec_token(t, &mut src) {
-                break;
-            }
-        }
-    }
-
-    fn pop(&mut self) -> V {
-        self.st.pop().unwrap_or(V::Null)
-    }
-    fn popn(&mut self) -> f64 {
-        self.pop().num().unwrap_or(0.0)
-    }
-    fn push(&mut self, v: V) {
-        if self.st.len() < 100_000 {
-            self.st.push(v);
-        }
-    }
-
-    fn lookup(&self, k: &str) -> Option<V> {
-        self.dicts.iter().rev().find_map(|d| d.borrow().get(k).cloned())
-    }
-
-    /// A token read from the file: procedures are pushed, names executed.
-    fn exec_token(&mut self, t: V, src: &mut Src) -> Result<(), Flow> {
-        match t {
-            V::Name(n) => self.exec_name(&n, src),
-            other => {
-                self.push(other);
-                Ok(())
-            }
-        }
-    }
-
-    /// Execute a value as an object (procedures run).
-    fn exec_obj(&mut self, v: V, src: &mut Src) -> Result<(), Flow> {
-        match v {
-            V::Proc(p) => {
-                if self.calls >= MAX_CALL_DEPTH {
-                    self.b.skip("PostScript (recursion limit)");
-                    return Err(Flow::Quit);
-                }
-                self.calls += 1;
-                let mut r = Ok(());
-                for x in p.iter() {
-                    match x {
-                        V::Name(n) => {
-                            r = self.exec_name(n, src);
-                            if r.is_err() {
-                                break;
-                            }
-                        }
-                        V::Op(op) => {
-                            r = self.spend(1).and_then(|()| self.builtin(op, src));
-                            if r.is_err() {
-                                break;
-                            }
-                        }
-                        // Other items count against the budget as names do.
-                        other => {
-                            r = self.spend(1);
-                            if r.is_err() {
-                                break;
-                            }
-                            self.push(other.clone());
-                        }
-                    }
-                }
-                self.calls -= 1;
-                r
-            }
-            // An executable name can run another (`exec` of `/exec cvx`), so names count too.
-            V::Name(n) => {
-                if self.calls >= MAX_CALL_DEPTH {
-                    self.b.skip("PostScript (recursion limit)");
-                    return Err(Flow::Quit);
-                }
-                self.calls += 1;
-                let r = self.exec_name(&n, src);
-                self.calls -= 1;
-                r
-            }
-            V::Op(op) => {
-                self.spend(1)?;
-                self.builtin(&op, src)
-            }
-            other => {
-                self.push(other);
-                Ok(())
-            }
-        }
-    }
-
-    fn exec_name(&mut self, n: &str, src: &mut Src) -> Result<(), Flow> {
-        self.spend(1)?;
-        if let Some(v) = self.lookup(n) {
-            return match v {
-                V::Proc(_) => self.exec_obj(v, src),
-                // An operator stored under another name (`/mo /moveto load def`, as Illustrator's
-                // EPS prolog does for every path operator) runs that operator. It pushed the
-                // operator's name instead, so such files drew nothing (#955).
-                V::Op(op) => self.builtin(&op, src),
-                // An executable name (`/y /x cvx def`) runs what that name is bound to.
-                V::Name(_) => self.exec_obj(v, src),
-                other => {
-                    self.push(other);
-                    Ok(())
-                }
-            };
-        }
-        self.builtin(n, src)
-    }
-
-    /// Count `n` operations against the budget, and stop the program when fewer are left. An
-    /// operator that makes, reads or copies path elements counts each one as an operation.
-    fn spend(&mut self, n: usize) -> Result<(), Flow> {
-        match self.budget.checked_sub(n) {
-            Some(left) => {
-                self.budget = left;
-                Ok(())
-            }
-            None => {
-                self.b.skip("PostScript (operation limit)");
-                Err(Flow::Quit)
-            }
-        }
-    }
-
-    fn device_scale(&self) -> f64 {
-        self.gs.ctm.determinant().abs().sqrt()
-    }
-
-    fn user_point(&mut self) -> Point {
-        let y = self.popn();
-        let x = self.popn();
-        Point::new(x, y)
-    }
-
-    /// Stop the program when a path of `len` elements would be longer than [`MAX_PATH`].
-    fn path_fits(&mut self, len: usize) -> Result<(), Flow> {
-        if len <= MAX_PATH {
-            return Ok(());
-        }
-        self.b.skip("PostScript (path limit)");
-        Err(Flow::Quit)
-    }
-
-    /// [`Self::path_fits`] for the current path with `n` more elements.
-    fn room(&mut self, n: usize) -> Result<(), Flow> {
-        self.path_fits(self.gs.path.elements().len().saturating_add(n))
-    }
-
-    fn move_to(&mut self, p: Point) -> Result<(), Flow> {
-        // A moveto right after a moveto replaces it (PostScript Language Reference §8.2, `moveto`).
-        if matches!(self.gs.path.elements().last(), Some(PathEl::MoveTo(_))) {
-            self.gs.path.pop();
-        }
-        self.room(1)?;
-        let q = self.gs.ctm * p;
-        self.gs.path.move_to(q);
-        self.gs.cur = Some(q);
-        self.gs.start = Some(q);
-        Ok(())
-    }
-    fn line_to(&mut self, p: Point) -> Result<(), Flow> {
-        self.room(1 + usize::from(self.gs.cur.is_none()))?;
-        let q = self.gs.ctm * p;
-        if self.gs.cur.is_none() {
-            self.gs.path.move_to(q);
-            self.gs.start = Some(q);
-        }
-        self.gs.path.line_to(q);
-        self.gs.cur = Some(q);
-        Ok(())
-    }
-    fn curve_to(&mut self, a: Point, b: Point, c: Point) -> Result<(), Flow> {
-        self.room(1 + usize::from(self.gs.cur.is_none()))?;
-        let m = self.gs.ctm;
-        if self.gs.cur.is_none() {
-            self.gs.path.move_to(m * a);
-        }
-        self.gs.path.curve_to(m * a, m * b, m * c);
-        self.gs.cur = Some(m * c);
-        Ok(())
-    }
-    fn current_user(&self) -> Point {
-        self.gs.ctm.inverse() * self.gs.cur.unwrap_or_default()
-    }
-
-    fn arc(&mut self, neg: bool) -> Result<(), Flow> {
-        let a2 = self.popn();
-        let a1 = self.popn();
-        let r = self.popn();
-        let c = self.user_point();
-        // `arc` raises `a2` by multiples of 360 until it is at least `a1`, and `arcn` lowers it
-        // until it is at most `a1` (PostScript Language Reference §8.2, `arc` and `arcn`). Those
-        // sweeps, and the first endpoint, are worked out from what is left of each angle after
-        // whole turns.
-        let sweep = if !neg && a2 < a1 {
-            ccw_turn(a1, a2)
-        } else if neg && a2 > a1 {
-            -ccw_turn(a2, a1)
-        } else {
-            a2 - a1
-        };
-        // A sweep of more than `MAX_ARC_TURNS` turns is shortened by whole pairs of turns to
-        // between `MAX_ARC_TURNS - 2` and `MAX_ARC_TURNS` turns, with a skip note. The arc still
-        // ends at `a2`, and an even-odd fill or clip of it covers the same area as the full sweep.
-        let max = MAX_ARC_TURNS * 360.0;
-        let sweep = if sweep.abs() > max {
-            self.b.skip("arc (too many turns)");
-            let s = sweep.signum();
-            s * (max - 720.0 + (s * (a2 % 720.0 - a1 % 720.0)).rem_euclid(720.0))
-        } else {
-            sweep
-        };
-        let (a1, sweep) = ((a1 % 360.0).to_radians(), sweep.to_radians());
-        let start = Point::new(c.x + r * a1.cos(), c.y + r * a1.sin());
-        if self.gs.cur.is_some() {
-            self.line_to(start)?;
-        } else {
-            self.move_to(start)?;
-        }
-        let arc = kurbo::Arc::new(c, (r, r), a1, sweep, 0.0);
-        let m = self.gs.ctm;
-        // kurbo divides an arc into more curves the larger the radius (about 3.7 × 10^49 for a
-        // quarter turn at a radius of 10^300, more than a usize can count), so each one counts
-        // against the budget and the path limit.
-        let mut curves = arc.append_iter(0.1);
-        while let Some(PathEl::CurveTo(p1, p2, p3)) = curves.next() {
-            self.room(1)?;
-            self.spend(1)?;
-            self.gs.path.curve_to(m * p1, m * p2, m * p3);
-            self.gs.cur = Some(m * p3);
-        }
-        Ok(())
-    }
-
-    fn paint(&mut self, fill: Option<FillRule>, stroke: bool) {
-        let path = std::mem::take(&mut self.gs.path);
-        self.gs.cur = None;
-        self.gs.start = None;
-        let s = self.device_scale();
-        let st = stroke.then(|| Stroke {
-            paint: Paint::Color(self.gs.color),
-            opacity: 1.0,
-            width: if self.gs.lw <= 0.0 { 1.0 } else { self.gs.lw * s },
-            cap: self.gs.cap,
-            join: self.gs.join,
-            miter: self.gs.miter.max(1.0),
-            dash: self.gs.dash.as_ref().map(|(a, o)| (a.iter().map(|v| v * s).collect(), o * s)),
-        });
-        self.b.fill_stroke(path, Affine::IDENTITY, fill.map(|r| (Paint::Color(self.gs.color), 1.0, r)), st);
-    }
-
-    fn rect_path(&mut self) -> Result<Vec<BezPath>, Flow> {
-        // x y w h, or an array / string of numbers.
-        let top = self.pop();
-        let nums: Vec<f64> = match &top {
-            V::Array(_) | V::Proc(_) => {
-                let items = top.items().unwrap_or_default();
-                // An array's rectangles count against the budget, five path elements each.
-                self.spend(items.len() / 4 * 5)?;
-                items.iter().filter_map(V::num).collect()
-            }
-            V::Num(h) => {
-                let w = self.popn();
-                let y = self.popn();
-                let x = self.popn();
-                vec![x, y, w, *h]
-            }
-            _ => vec![],
-        };
-        self.path_fits(nums.len() / 4 * 5)?;
-        let m = self.gs.ctm;
-        Ok(nums
-            .as_chunks::<4>()
-            .0
-            .iter()
-            .map(|r| {
-                let mut p = BezPath::new();
-                p.move_to(m * Point::new(r[0], r[1]));
-                p.line_to(m * Point::new(r[0] + r[2], r[1]));
-                p.line_to(m * Point::new(r[0] + r[2], r[1] + r[3]));
-                p.line_to(m * Point::new(r[0], r[1] + r[3]));
-                p.close_path();
-                p
-            })
-            .collect())
-    }
-
-    fn grestore(&mut self) {
-        if let Some(g) = self.saved.pop() {
-            let d = g.depth;
-            self.gs = g;
-            self.b.close_to(d);
-        }
-    }
-
-    fn builtin(&mut self, n: &str, src: &mut Src) -> Result<(), Flow> {
-        match n {
-            // Stack.
-            "pop" => {
-                self.pop();
-            }
-            "exch" => {
-                let b = self.pop();
-                let a = self.pop();
-                self.push(b);
-                self.push(a);
-            }
-            "dup" => {
-                let a = self.st.last().cloned().unwrap_or(V::Null);
-                self.push(a);
-            }
-            "copy" => match self.pop() {
-                V::Num(k) => {
-                    let k = (k.max(0.0) as usize).min(self.st.len());
-                    let tail: Vec<V> = self.st[self.st.len() - k..].to_vec();
-                    self.st.extend(tail);
-                }
-                V::Array(dst) => {
-                    let s = self.pop().items().unwrap_or_default();
-                    let mut d = dst.borrow_mut();
-                    for (i, v) in s.into_iter().enumerate() {
-                        if i < d.len() {
-                            d[i] = v;
-                        }
-                    }
-                    drop(d);
-                    self.push(V::Array(dst));
-                }
-                other => self.push(other),
-            },
-            "index" => {
-                let k = self.popn().max(0.0) as usize;
-                let v = if k < self.st.len() { self.st[self.st.len() - 1 - k].clone() } else { V::Null };
-                self.push(v);
-            }
-            "roll" => {
-                let j = self.popn() as i64;
-                let k = (self.popn().max(0.0) as usize).min(self.st.len());
-                if k > 0 {
-                    let s = self.st.len() - k;
-                    let r = j.rem_euclid(k as i64) as usize;
-                    self.st[s..].rotate_right(r);
-                }
-            }
-            "clear" => self.st.clear(),
-            "count" => self.push(V::Num(self.st.len() as f64)),
-            "mark" | "[" | "<<" => self.push(V::Mark),
-            "cleartomark" => {
-                while let Some(v) = self.st.pop() {
-                    if matches!(v, V::Mark) {
-                        break;
-                    }
-                }
-            }
-            "counttomark" => {
-                let k = self.st.iter().rev().position(|v| matches!(v, V::Mark)).unwrap_or(self.st.len());
-                self.push(V::Num(k as f64));
-            }
-            "]" => {
-                let k = self.st.iter().rev().position(|v| matches!(v, V::Mark)).unwrap_or(self.st.len());
-                let items = self.st.split_off(self.st.len() - k);
-                self.st.pop();
-                self.push(array(items));
-            }
-            ">>" => {
-                let k = self.st.iter().rev().position(|v| matches!(v, V::Mark)).unwrap_or(self.st.len());
-                let items = self.st.split_off(self.st.len() - k);
-                self.st.pop();
-                let d = new_dict();
-                for kv in items.as_chunks::<2>().0 {
-                    d.borrow_mut().insert(kv[0].key(), kv[1].clone());
-                }
-                self.push(V::Dict(d));
-            }
-            // Arithmetic.
-            "add" | "sub" | "mul" | "div" | "idiv" | "mod" | "atan" | "exp" | "max" | "min" => {
-                let b = self.popn();
-                let a = self.popn();
-                let v = match n {
-                    "add" => a + b,
-                    "sub" => a - b,
-                    "mul" => a * b,
-                    "div" => {
-                        if b == 0.0 {
-                            0.0
-                        } else {
-                            a / b
-                        }
-                    }
-                    // `checked_*` give 0 both for a zero divisor and for the one overflowing
-                    // case, `i64::MIN / -1` (`/` and `%` panic on it in every build).
-                    "idiv" => (a as i64).checked_div(b as i64).unwrap_or(0) as f64,
-                    "mod" => (a as i64).checked_rem(b as i64).unwrap_or(0) as f64,
-                    "atan" => a.atan2(b).to_degrees().rem_euclid(360.0),
-                    "exp" => a.powf(b),
-                    "max" => a.max(b),
-                    _ => a.min(b),
-                };
-                self.push(V::Num(if v.is_finite() { v } else { 0.0 }));
-            }
-            "neg" | "abs" | "sqrt" | "sin" | "cos" | "ln" | "log" | "cvi" | "cvr" | "round" | "floor" | "ceiling" | "truncate" => {
-                let a = match self.pop() {
-                    V::Str(s) => parse_num(&s.borrow()).unwrap_or(0.0),
-                    v => v.num().unwrap_or(0.0),
-                };
-                let v = match n {
-                    "neg" => -a,
-                    "abs" => a.abs(),
-                    "sqrt" => a.max(0.0).sqrt(),
-                    "sin" => a.to_radians().sin(),
-                    "cos" => a.to_radians().cos(),
-                    "ln" => a.ln(),
-                    "log" => a.log10(),
-                    "cvi" | "truncate" => a.trunc(),
-                    "round" => (a + 0.5).floor(),
-                    "floor" => a.floor(),
-                    "ceiling" => a.ceil(),
-                    _ => a,
-                };
-                self.push(V::Num(if v.is_finite() { v } else { 0.0 }));
-            }
-            // Comparison and logic.
-            "eq" | "ne" => {
-                let b = self.pop();
-                let a = self.pop();
-                let eq = match (&a, &b) {
-                    (V::Num(x), V::Num(y)) => x == y,
-                    (V::Bool(x), V::Bool(y)) => x == y,
-                    (V::Null, V::Null) => true,
-                    (V::Array(x), V::Array(y)) => Rc::ptr_eq(x, y),
-                    (V::Dict(x), V::Dict(y)) => Rc::ptr_eq(x, y),
-                    (x, y) => !x.key().is_empty() && x.key() == y.key(),
-                };
-                self.push(V::Bool(eq == (n == "eq")));
-            }
-            "gt" | "ge" | "lt" | "le" => {
-                let b = self.popn();
-                let a = self.popn();
-                self.push(V::Bool(match n {
-                    "gt" => a > b,
-                    "ge" => a >= b,
-                    "lt" => a < b,
-                    _ => a <= b,
-                }));
-            }
-            "not" => match self.pop() {
-                V::Bool(b) => self.push(V::Bool(!b)),
-                v => self.push(V::Num(!(v.num().unwrap_or(0.0) as i64) as f64)),
-            },
-            "and" | "or" | "xor" => {
-                let b = self.pop();
-                let a = self.pop();
-                match (a, b) {
-                    (V::Bool(x), V::Bool(y)) => self.push(V::Bool(match n {
-                        "and" => x && y,
-                        "or" => x || y,
-                        _ => x ^ y,
-                    })),
-                    (x, y) => {
-                        let (x, y) = (x.num().unwrap_or(0.0) as i64, y.num().unwrap_or(0.0) as i64);
-                        self.push(V::Num(match n {
-                            "and" => x & y,
-                            "or" => x | y,
-                            _ => x ^ y,
-                        } as f64));
-                    }
-                }
-            }
-            "true" => self.push(V::Bool(true)),
-            "false" => self.push(V::Bool(false)),
-            "null" => self.push(V::Null),
-            // Control.
-            "exec" => {
-                let v = self.pop();
-                self.exec_obj(v, src)?;
-            }
-            "if" => {
-                let p = self.pop();
-                if let V::Bool(true) = self.pop() {
-                    self.exec_obj(p, src)?;
-                }
-            }
-            "ifelse" => {
-                let f = self.pop();
-                let t = self.pop();
-                let c = matches!(self.pop(), V::Bool(true));
-                self.exec_obj(if c { t } else { f }, src)?;
-            }
-            // Each pass of a loop counts against the budget.
-            "repeat" => {
-                let p = self.pop();
-                let k = self.popn().clamp(0.0, 1e6) as usize;
-                for _ in 0..k {
-                    self.spend(1)?;
-                    match self.exec_obj(p.clone(), src) {
-                        Err(Flow::Exit) => break,
-                        r => r?,
-                    }
-                }
-            }
-            "for" => {
-                let p = self.pop();
-                let lim = self.popn();
-                let inc = self.popn();
-                let mut i = self.popn();
-                let mut guard = 0;
-                while inc != 0.0 && ((inc > 0.0 && i <= lim) || (inc < 0.0 && i >= lim)) && guard < 1_000_000 {
-                    self.spend(1)?;
-                    self.push(V::Num(i));
-                    match self.exec_obj(p.clone(), src) {
-                        Err(Flow::Exit) => break,
-                        r => r?,
-                    }
-                    i += inc;
-                    guard += 1;
-                }
-            }
-            "loop" => {
-                let p = self.pop();
-                for _ in 0..1_000_000 {
-                    self.spend(1)?;
-                    match self.exec_obj(p.clone(), src) {
-                        Err(Flow::Exit) => break,
-                        r => r?,
-                    }
-                }
-            }
-            "forall" => {
-                let p = self.pop();
-                match self.pop() {
-                    V::Dict(d) => {
-                        let items: Vec<(String, V)> = d.borrow().iter().map(|(k, v)| (k.clone(), v.clone())).collect();
-                        for (k, v) in items {
-                            self.spend(1)?;
-                            self.push(V::Lit(k.into()));
-                            self.push(v);
-                            match self.exec_obj(p.clone(), src) {
-                                Err(Flow::Exit) => break,
-                                r => r?,
-                            }
-                        }
-                    }
-                    V::Str(s) => {
-                        let bytes = s.borrow().clone();
-                        for c in bytes {
-                            self.spend(1)?;
-                            self.push(V::Num(c as f64));
-                            match self.exec_obj(p.clone(), src) {
-                                Err(Flow::Exit) => break,
-                                r => r?,
-                            }
-                        }
-                    }
-                    a => {
-                        for v in a.items().unwrap_or_default() {
-                            self.spend(1)?;
-                            self.push(v);
-                            match self.exec_obj(p.clone(), src) {
-                                Err(Flow::Exit) => break,
-                                r => r?,
-                            }
-                        }
-                    }
-                }
-            }
-            "exit" => return Err(Flow::Exit),
-            "stop" => return Err(Flow::Stop),
-            "stopped" => {
-                let p = self.pop();
-                let stopped = match self.exec_obj(p, src) {
-                    Err(Flow::Quit) => return Err(Flow::Quit),
-                    Err(_) => true,
-                    Ok(()) => false,
-                };
-                self.push(V::Bool(stopped));
-            }
-            "quit" => return Err(Flow::Quit),
-            "showpage" | "copypage" => {}
-            // Dictionaries.
-            "def" => {
-                let v = self.pop();
-                let k = self.pop().key();
-                if let Some(d) = self.dicts.last() {
-                    d.borrow_mut().insert(k, v);
-                }
-            }
-            "store" => {
-                let v = self.pop();
-                let k = self.pop().key();
-                let d = self.dicts.iter().rev().find(|d| d.borrow().contains_key(&k)).or(self.dicts.last()).cloned();
-                if let Some(d) = d {
-                    d.borrow_mut().insert(k, v);
-                }
-            }
-            "load" => {
-                let k = self.pop().key();
-                let v = self.lookup(&k).unwrap_or(V::Op(k.into()));
-                self.push(v);
-            }
-            "undef" => {
-                let k = self.pop().key();
-                if let V::Dict(d) = self.pop() {
-                    d.borrow_mut().remove(&k);
-                }
-            }
-            "dict" => {
-                self.pop();
-                self.push(V::Dict(new_dict()));
-            }
-            "begin" => {
-                if let V::Dict(d) = self.pop()
-                    && self.dicts.len() < 64
-                {
-                    self.dicts.push(d);
-                }
-            }
-            "end" => {
-                if self.dicts.len() > 1 {
-                    self.dicts.pop();
-                }
-            }
-            "currentdict" => {
-                let d = self.dicts.last().cloned().unwrap_or_else(new_dict);
-                self.push(V::Dict(d));
-            }
-            "userdict" | "globaldict" | "systemdict" | "statusdict" | "errordict" | "$error" => {
-                let d = self.dicts[0].clone();
-                self.push(V::Dict(d));
-            }
-            "where" => {
-                let k = self.pop().key();
-                match self.dicts.iter().rev().find(|d| d.borrow().contains_key(&k)).cloned() {
-                    Some(d) => {
-                        self.push(V::Dict(d));
-                        self.push(V::Bool(true));
-                    }
-                    None => self.push(V::Bool(false)),
-                }
-            }
-            "known" => {
-                let k = self.pop().key();
-                let v = match self.pop() {
-                    V::Dict(d) => d.borrow().contains_key(&k),
-                    _ => false,
-                };
-                self.push(V::Bool(v));
-            }
-            "countdictstack" => self.push(V::Num(self.dicts.len() as f64)),
-            "cleardictstack" => self.dicts.truncate(1),
-            "findresource" | "findfont" | "findencoding" => {
-                let category = if n == "findresource" { self.pop().key() } else { String::new() };
-                let key = self.pop().key();
-                match (n, category.as_str()) {
-                    ("findfont", _) | (_, "Font") => {
-                        let f = self.find_font(&key);
-                        self.push(V::Dict(f));
-                    }
-                    ("findencoding", _) | (_, "Encoding") => self.push(encoding_array(&key)),
-                    _ => self.push(V::Dict(new_dict())),
-                }
-            }
-            "defineresource" => {
-                let category = self.pop().key();
-                let v = self.pop();
-                let key = self.pop().key();
-                if let (V::Dict(d), "Font") = (&v, category.as_str()) {
-                    self.font_dir.insert(key, d.clone());
-                }
-                self.push(v);
-            }
-            "resourcestatus" => {
-                self.pop();
-                self.pop();
-                self.push(V::Bool(false));
-            }
-            // Arrays and strings.
-            "array" => {
-                let k = self.popn().clamp(0.0, 1e6) as usize;
-                self.push(array(vec![V::Null; k]));
-            }
-            "string" => {
-                let k = self.popn().clamp(0.0, 1e7) as usize;
-                self.push(V::Str(Rc::new(RefCell::new(vec![0; k]))));
-            }
-            "length" => {
-                let l = match self.pop() {
-                    V::Str(s) => s.borrow().len(),
-                    V::Dict(d) => d.borrow().len(),
-                    V::Name(s) | V::Lit(s) => s.len(),
-                    v => v.items().map_or(0, |i| i.len()),
-                };
-                self.push(V::Num(l as f64));
-            }
-            "get" => {
-                let k = self.pop();
-                let v = match self.pop() {
-                    V::Dict(d) => d.borrow().get(&k.key()).cloned().unwrap_or(V::Null),
-                    V::Str(s) => V::Num(s.borrow().get(k.num().unwrap_or(0.0) as usize).copied().unwrap_or(0) as f64),
-                    a => a.items().and_then(|i| i.get(k.num().unwrap_or(0.0) as usize).cloned()).unwrap_or(V::Null),
-                };
-                self.push(v);
-            }
-            "put" => {
-                let v = self.pop();
-                let k = self.pop();
-                match self.pop() {
-                    V::Dict(d) => {
-                        d.borrow_mut().insert(k.key(), v);
-                    }
-                    V::Array(a) => {
-                        let i = k.num().unwrap_or(0.0) as usize;
-                        if let Some(slot) = a.borrow_mut().get_mut(i) {
-                            *slot = v;
-                        }
-                    }
-                    V::Str(s) => {
-                        let i = k.num().unwrap_or(0.0) as usize;
-                        if let Some(slot) = s.borrow_mut().get_mut(i) {
-                            *slot = v.num().unwrap_or(0.0) as u8;
-                        }
-                    }
-                    _ => {}
-                }
-            }
-            "getinterval" => {
-                let c = self.popn().max(0.0) as usize;
-                let i = self.popn().max(0.0) as usize;
-                match self.pop() {
-                    V::Str(s) => {
-                        let b = s.borrow();
-                        let part = b.get(i.min(b.len())..(i + c).min(b.len())).unwrap_or(&[]).to_vec();
-                        drop(b);
-                        self.push(V::Str(Rc::new(RefCell::new(part))));
-                    }
-                    a => {
-                        let items = a.items().unwrap_or_default();
-                        let part = items.get(i.min(items.len())..(i + c).min(items.len())).unwrap_or(&[]).to_vec();
-                        self.push(array(part));
-                    }
-                }
-            }
-            "putinterval" => {
-                self.pop();
-                self.pop();
-                self.pop();
-            }
-            "aload" => {
-                let a = self.pop();
-                for v in a.items().unwrap_or_default() {
-                    self.push(v);
-                }
-                self.push(a);
-            }
-            "astore" => {
-                let a = self.pop();
-                if let V::Array(arr) = &a {
-                    let k = arr.borrow().len().min(self.st.len());
-                    let items = self.st.split_off(self.st.len() - k);
-                    *arr.borrow_mut() = items;
-                }
-                self.push(a);
-            }
-            "cvx" => match self.pop() {
-                V::Array(a) => self.push(V::Proc(Rc::new(a.borrow().clone()))),
-                V::Lit(s) => self.push(V::Name(s)),
-                V::Str(s) => {
-                    // Executable string: tokenize it as a procedure.
-                    let bytes = s.borrow().clone();
-                    let mut sub = Src { d: &bytes, pos: 0 };
-                    let mut body = vec![];
-                    while let Some(t) = sub.token(0) {
-                        body.push(t);
-                    }
-                    self.push(V::Proc(Rc::new(body)));
-                }
-                v => self.push(v),
-            },
-            "cvlit" => match self.pop() {
-                V::Proc(p) => self.push(array(p.as_ref().clone())),
-                V::Name(s) => self.push(V::Lit(s)),
-                v => self.push(v),
-            },
-            "cvn" => {
-                let k = self.pop().key();
-                self.push(V::Lit(k.into()));
-            }
-            "cvs" => {
-                self.pop();
-                let k = self.pop().key();
-                self.push(V::Str(Rc::new(RefCell::new(k.into_bytes()))));
-            }
-            "xcheck" => {
-                let v = self.pop();
-                self.push(V::Bool(matches!(v, V::Proc(_) | V::Name(_) | V::Op(_))));
-            }
-            "type" => {
-                let t = match self.pop() {
-                    V::Num(_) => "realtype",
-                    V::Bool(_) => "booleantype",
-                    V::Name(_) | V::Lit(_) => "nametype",
-                    V::Op(_) => "operatortype",
-                    V::Str(_) => "stringtype",
-                    V::Proc(_) | V::Array(_) => "arraytype",
-                    V::Dict(_) => "dicttype",
-                    V::Mark => "marktype",
-                    V::Null => "nulltype",
-                    V::File => "filetype",
-                };
-                self.push(V::Name(t.into()));
-            }
-            "bind" | "readonly" | "executeonly" | "noaccess" => {}
-            "languagelevel" => self.push(V::Num(3.0)),
-            "version" | "product" => self.push(V::Str(Rc::new(RefCell::new(b"3010".to_vec())))),
-            "save" => {
-                self.spend(self.gs.path.elements().len())?;
-                self.saved.push(self.gs.clone());
-                self.gs.depth = self.b.depth();
-                self.push(V::Null);
-            }
-            "restore" => {
-                self.pop();
-                self.grestore();
-            }
-            "currentfile" => self.push(V::File),
-            "readstring" | "readhexstring" | "readline" => {
-                self.pop();
-                self.pop();
-                self.push(V::Str(Rc::new(RefCell::new(vec![]))));
-                self.push(V::Bool(false));
-            }
-            "flushfile" | "closefile" | "print" | "==" | "=" | "pstack" | "setpagedevice" | "setglobal" | "setpacking" | "setshared" | "setobjectformat"
-            | "setsmoothness" => {
-                if !matches!(n, "pstack") {
-                    self.pop();
-                }
-            }
-            "currentglobal" | "currentpacking" | "currentshared" => self.push(V::Bool(false)),
-            // Operators that return values must push them, or the rest of the program reads a
-            // shifted stack: Illustrator's EPS prolog queries the device this way and then drew
-            // nothing (#955). Values are a plain device's defaults (PostScript Language
-            // Reference, 3rd ed., chapter 8).
-            "currentflat" => self.push(V::Num(1.0)),
-            "currentscreen" => {
-                self.push(V::Num(60.0));
-                self.push(V::Num(45.0));
-                self.push(V::Proc(Rc::new(vec![])));
-            }
-            "currentblackgeneration" | "currentundercolorremoval" | "currenttransfer" => self.push(V::Proc(Rc::new(vec![]))),
-            "currentcolortransfer" => {
-                for _ in 0..4 {
-                    self.push(V::Proc(Rc::new(vec![])));
-                }
-            }
-            "currentpagedevice" | "currenthalftone" | "currentsystemparams" | "currentuserparams" | "currentdevparams" => {
-                if n == "currentdevparams" {
-                    self.pop();
-                }
-                self.push(V::Dict(new_dict()));
-            }
-            "setuserparams" | "setsystemparams" | "setcolortransfer" | "setblackgeneration" | "setundercolorremoval" => {
-                let k = if n == "setcolortransfer" { 4 } else { 1 };
-                for _ in 0..k {
-                    self.pop();
-                }
-            }
-            // `file status` → false; `string status` → false (no such file).
-            "status" => {
-                self.pop();
-                self.push(V::Bool(false));
-            }
-            "dictstack" => {
-                self.pop();
-                let ds: Vec<V> = self.dicts.iter().map(|d| V::Dict(d.clone())).collect();
-                self.push(array(ds));
-            }
-            "maxlength" => {
-                let k = match self.pop() {
-                    V::Dict(d) => d.borrow().len(),
-                    _ => 0,
-                };
-                self.push(V::Num(k.saturating_add(16) as f64));
-            }
-            "internaldict" => {
-                self.pop();
-                let d = self.dicts[0].clone();
-                self.push(V::Dict(d));
-            }
-            "undefineresource" => {
-                self.pop();
-                self.pop();
-            }
-            // `[ … /Name pdfmark`: a Distiller annotation; other interpreters discard it.
-            "pdfmark" => {
-                while let Some(v) = self.st.pop() {
-                    if matches!(v, V::Mark) {
-                        break;
-                    }
-                }
-            }
-            // `source [params] /Name filter`. A SubFileDecode of the current file with a count of
-            // 0 reads to its end-of-data string: skip that data (an embedded XMP packet, which
-            // otherwise ran as PostScript). Other filters read what their source reads.
-            "filter" => {
-                let name = self.pop().key();
-                let mut skipped = false;
-                let source = if name == "SubFileDecode" && !matches!(self.st.last(), Some(V::Dict(_))) {
-                    let eod = match self.pop() {
-                        V::Str(s) => s.borrow().clone(),
-                        _ => vec![],
-                    };
-                    let count = self.popn();
-                    let source = self.pop();
-                    if matches!(source, V::File) && count == 0.0 && !eod.is_empty() {
-                        src.pos = match find_from(src.d, &eod, src.pos) {
-                            Some(p) => p.saturating_add(eod.len()),
-                            None => src.d.len(),
-                        };
-                        skipped = true;
-                    }
-                    source
-                } else {
-                    if matches!(self.st.last(), Some(V::Dict(_))) {
-                        self.pop();
-                    }
-                    self.pop()
-                };
-                // Data already stepped over leaves nothing for `image` to skip.
-                self.push(if skipped { V::Null } else { source });
-            }
-            "vmstatus" => {
-                for _ in 0..3 {
-                    self.push(V::Num(0.0));
-                }
-            }
-            // Graphics state.
-            "gsave" => {
-                self.spend(self.gs.path.elements().len())?;
-                let mut g = self.gs.clone();
-                g.depth = self.b.depth();
-                self.saved.push(g);
-            }
-            "grestore" => self.grestore(),
-            "grestoreall" => {
-                while !self.saved.is_empty() {
-                    self.grestore();
-                }
-            }
-            "initgraphics" => {
-                self.gs.ctm = Affine::IDENTITY;
-                self.gs.lw = 1.0;
-                self.gs.color = [0.0; 3];
-            }
-            "setlinewidth" => self.gs.lw = self.popn(),
-            "currentlinewidth" => self.push(V::Num(self.gs.lw)),
-            "setlinecap" => self.gs.cap = [Cap::Butt, Cap::Round, Cap::Square][(self.popn().max(0.0) as usize).min(2)],
-            "setlinejoin" => self.gs.join = [Join::Miter, Join::Round, Join::Bevel][(self.popn().max(0.0) as usize).min(2)],
-            "setmiterlimit" => self.gs.miter = self.popn(),
-            "setdash" => {
-                let off = self.popn();
-                let a: Vec<f64> = self.pop().items().unwrap_or_default().iter().filter_map(V::num).collect();
-                self.gs.dash = (!a.is_empty() && a.iter().any(|v| *v > 0.0)).then_some((a, off));
-            }
-            "setflat" | "setstrokeadjust" | "setoverprint" | "setrenderingintent" | "setcolorrendering" | "sethalftone" | "settransfer" => {
-                self.pop();
-            }
-            // frequency angle proc
-            "setscreen" => {
-                for _ in 0..3 {
-                    self.pop();
-                }
-            }
-            "setgray" => {
-                let g = self.popn().clamp(0.0, 1.0);
-                self.gs.color = [g; 3];
-            }
-            "setrgbcolor" => {
-                let b = self.popn();
-                let g = self.popn();
-                let r = self.popn();
-                self.gs.color = [r, g, b].map(|v| v.clamp(0.0, 1.0));
-            }
-            "sethsbcolor" => {
-                let v = self.popn().clamp(0.0, 1.0);
-                let s = self.popn().clamp(0.0, 1.0);
-                let h = self.popn().rem_euclid(1.0) * 6.0;
-                let (i, f) = (h.floor() as i32, h.fract());
-                let (p, q, t) = (v * (1.0 - s), v * (1.0 - s * f), v * (1.0 - s * (1.0 - f)));
-                self.gs.color = match i {
-                    0 => [v, t, p],
-                    1 => [q, v, p],
-                    2 => [p, v, t],
-                    3 => [p, q, v],
-                    4 => [t, p, v],
-                    _ => [v, p, q],
-                };
-            }
-            "setcmykcolor" => {
-                let k = self.popn().clamp(0.0, 1.0);
-                let y = self.popn().clamp(0.0, 1.0);
-                let m = self.popn().clamp(0.0, 1.0);
-                let c = self.popn().clamp(0.0, 1.0);
-                self.gs.color = [(1.0 - c) * (1.0 - k), (1.0 - m) * (1.0 - k), (1.0 - y) * (1.0 - k)];
-            }
-            "setcolorspace" => {
-                self.pop();
-            }
-            "setcolor" => {
-                // Device colour by operand count (patterns are not drawn).
-                let k = self.st.iter().rev().take_while(|v| matches!(v, V::Num(_))).count().min(4);
-                let c: Vec<f64> = self.st.split_off(self.st.len() - k).iter().filter_map(V::num).collect();
-                self.gs.color = match c.len() {
-                    1 => [c[0]; 3],
-                    3 => [c[0], c[1], c[2]],
-                    4 => [(1.0 - c[0]) * (1.0 - c[3]), (1.0 - c[1]) * (1.0 - c[3]), (1.0 - c[2]) * (1.0 - c[3])],
-                    _ => self.gs.color,
-                };
-            }
-            "currentgray" => self.push(V::Num((self.gs.color[0] + self.gs.color[1] + self.gs.color[2]) / 3.0)),
-            "currentrgbcolor" => {
-                for c in self.gs.color {
-                    self.push(V::Num(c));
-                }
-            }
-            // Coordinates.
-            "matrix" => self.push(matrix_val(Affine::IDENTITY)),
-            "identmatrix" | "defaultmatrix" => {
-                self.pop();
-                self.push(matrix_val(Affine::IDENTITY));
-            }
-            "currentmatrix" => {
-                self.pop();
-                self.push(matrix_val(self.gs.ctm));
-            }
-            "setmatrix" => {
-                let m = self.pop();
-                self.gs.ctm = matrix_of(&m).unwrap_or(Affine::IDENTITY);
-            }
-            "concat" => {
-                let m = self.pop();
-                if let Some(m) = matrix_of(&m) {
-                    self.gs.ctm *= m;
-                }
-            }
-            "concatmatrix" => {
-                self.pop();
-                let b = self.pop();
-                let a = self.pop();
-                let (a, b) = (matrix_of(&a).unwrap_or(Affine::IDENTITY), matrix_of(&b).unwrap_or(Affine::IDENTITY));
-                self.push(matrix_val(b * a));
-            }
-            "invertmatrix" => {
-                self.pop();
-                let a = self.pop();
-                self.push(matrix_val(matrix_of(&a).unwrap_or(Affine::IDENTITY).inverse()));
-            }
-            "translate" | "scale" => {
-                let top = self.pop();
-                let (m_out, y) = match top {
-                    V::Array(_) => (Some(top), self.popn()),
-                    v => (None, v.num().unwrap_or(0.0)),
-                };
-                let x = self.popn();
-                let t = if n == "translate" { Affine::translate((x, y)) } else { Affine::scale_non_uniform(x, y) };
-                match m_out {
-                    Some(_) => self.push(matrix_val(t)),
-                    None => self.gs.ctm *= t,
-                }
-            }
-            "rotate" => {
-                let top = self.pop();
-                match top {
-                    V::Array(_) => {
-                        let a = self.popn();
-                        self.push(matrix_val(Affine::rotate(a.to_radians())));
-                    }
-                    v => self.gs.ctm *= Affine::rotate(v.num().unwrap_or(0.0).to_radians()),
-                }
-            }
-            "transform" | "itransform" | "dtransform" | "idtransform" => {
-                let top = self.pop();
-                let (m, y) = match top {
-                    V::Array(_) | V::Proc(_) => (matrix_of(&top).unwrap_or(Affine::IDENTITY), self.popn()),
-                    v => (self.gs.ctm, v.num().unwrap_or(0.0)),
-                };
-                let x = self.popn();
-                let m = if n.starts_with('i') { m.inverse() } else { m };
-                let p = if n.contains('d') {
-                    let c = m.as_coeffs();
-                    Point::new(c[0] * x + c[2] * y, c[1] * x + c[3] * y)
-                } else {
-                    m * Point::new(x, y)
-                };
-                self.push(V::Num(p.x));
-                self.push(V::Num(p.y));
-            }
-            // Paths.
-            "newpath" => {
-                self.gs.path = BezPath::new();
-                self.gs.cur = None;
-                self.gs.start = None;
-            }
-            "moveto" => {
-                let p = self.user_point();
-                self.move_to(p)?;
-            }
-            "rmoveto" => {
-                let d = self.user_point();
-                let c = self.current_user();
-                self.move_to(Point::new(c.x + d.x, c.y + d.y))?;
-            }
-            "lineto" => {
-                let p = self.user_point();
-                self.line_to(p)?;
-            }
-            "rlineto" => {
-                let d = self.user_point();
-                let c = self.current_user();
-                self.line_to(Point::new(c.x + d.x, c.y + d.y))?;
-            }
-            "curveto" | "rcurveto" => {
-                let p3 = self.user_point();
-                let p2 = self.user_point();
-                let p1 = self.user_point();
-                if n == "rcurveto" {
-                    let c = self.current_user();
-                    let o = |p: Point| Point::new(c.x + p.x, c.y + p.y);
-                    self.curve_to(o(p1), o(p2), o(p3))?;
-                } else {
-                    self.curve_to(p1, p2, p3)?;
-                }
-            }
-            "closepath" => {
-                if self.gs.cur.is_some() {
-                    self.room(1)?;
-                    self.gs.path.close_path();
-                    self.gs.cur = self.gs.start;
-                }
-            }
-            "arc" => self.arc(false)?,
-            "arcn" => self.arc(true)?,
-            "currentpoint" => {
-                let c = self.current_user();
-                self.push(V::Num(c.x));
-                self.push(V::Num(c.y));
-            }
-            "pathbbox" => {
-                self.spend(self.gs.path.elements().len())?;
-                let r = kurbo::Shape::bounding_box(&self.gs.path);
-                let inv = self.gs.ctm.inverse();
-                let (a, b) = (inv * Point::new(r.x0, r.y0), inv * Point::new(r.x1, r.y1));
-                for v in [a.x.min(b.x), a.y.min(b.y), a.x.max(b.x), a.y.max(b.y)] {
-                    self.push(V::Num(v));
-                }
-            }
-            "flattenpath" | "reversepath" | "strokepath" | "initclip" => {}
-            "clippath" => {
-                let p = self.page;
-                self.gs.path = kurbo::Shape::to_path(&kurbo::Rect::new(p[0], p[1], p[2], p[3]), 0.1);
-            }
-            // Painting.
-            "fill" => self.paint(Some(FillRule::NonZero), false),
-            "eofill" => self.paint(Some(FillRule::EvenOdd), false),
-            "stroke" => self.paint(None, true),
-            "clip" | "eoclip" => {
-                let rule = if n == "clip" { FillRule::NonZero } else { FillRule::EvenOdd };
-                self.spend(self.gs.path.elements().len())?;
-                let p = self.gs.path.clone();
-                if !p.elements().iter().all(|e| matches!(e, PathEl::MoveTo(_))) {
-                    self.b.clip(p, rule);
-                }
-            }
-            "rectfill" | "rectstroke" | "rectclip" => {
-                let paths = self.rect_path()?;
-                if n == "rectstroke" && matches!(self.st.last(), Some(V::Array(_))) {
-                    self.pop();
-                }
-                let mut all = BezPath::new();
-                for p in paths {
-                    all.extend(p);
-                }
-                match n {
-                    "rectclip" => self.b.clip(all, FillRule::NonZero),
-                    _ => {
-                        let saved = std::mem::replace(&mut self.gs.path, all);
-                        self.paint(if n == "rectfill" { Some(FillRule::NonZero) } else { None }, n == "rectstroke");
-                        self.gs.path = saved;
-                    }
-                }
-            }
-            "shfill" => {
-                self.pop();
-                self.b.skip("smooth shading (shfill)");
-            }
-            // Text (see `text_op`).
-            "scalefont" | "makefont" | "selectfont" | "setfont" | "show" | "charpath" | "glyphshow" | "rootfont" | "currentfont" | "setcachedevice"
-            | "setcharwidth" | "ashow" | "widthshow" | "awidthshow" | "xshow" | "yshow" | "xyshow" | "kshow" | "cshow" | "stringwidth" | "definefont"
-            | "StandardEncoding" | "ISOLatin1Encoding" | "eexec" | "StartData" | "undefinefont" => self.text_op(n, src)?,
-            // Images: operands popped, inline data skipped.
-            "image" | "imagemask" | "colorimage" => {
-                let mut reads_file = false;
-                let check = |v: &V, rf: &mut bool| {
-                    if matches!(v, V::File) || matches!(v, V::Proc(p) if p.iter().any(|x| matches!(x, V::Name(n) if &**n == "currentfile"))) {
-                        *rf = true;
-                    }
-                };
-                if n == "colorimage" {
-                    let ncomp = self.popn().max(1.0) as usize;
-                    let multi = matches!(self.pop(), V::Bool(true));
-                    for _ in 0..if multi { ncomp.min(4) } else { 1 } {
-                        let v = self.pop();
-                        check(&v, &mut reads_file);
-                    }
-                    for _ in 0..4 {
-                        self.pop();
-                    }
-                } else {
-                    match self.pop() {
-                        V::Dict(d) => {
-                            if let Some(ds) = d.borrow().get("DataSource") {
-                                check(ds, &mut reads_file);
-                            }
-                        }
-                        top => {
-                            check(&top, &mut reads_file);
-                            for _ in 0..4 {
-                                self.pop();
-                            }
-                        }
-                    }
-                }
-                if reads_file {
-                    src.skip_image_data();
-                }
-                self.b.skip("image");
-            }
-            _ => {
-                if self.unknown.len() < 32 && !self.unknown.iter().any(|u| u == n) {
-                    self.unknown.push(n.to_string());
-                }
-            }
-        }
-        Ok(())
-    }
-}
-
-/// The PostScript section of an EPS file (DOS EPS binary header handled) and its bounding box
-/// (`%%HiResBoundingBox` preferred).
-pub fn eps_parts(bytes: &[u8]) -> Option<(&[u8], [f64; 4])> {
-    let ps = if bytes.starts_with(&[0xC5, 0xD0, 0xD3, 0xC6]) && bytes.len() >= 12 {
-        let off = u32::from_le_bytes([bytes[4], bytes[5], bytes[6], bytes[7]]) as usize;
-        let len = u32::from_le_bytes([bytes[8], bytes[9], bytes[10], bytes[11]]) as usize;
-        bytes.get(off..off.checked_add(len)?.min(bytes.len()))?
-    } else {
-        bytes
-    };
-    let find_box = |key: &[u8]| -> Option<[f64; 4]> {
-        let mut from = 0;
-        while let Some(p) = ps[from..].windows(key.len()).position(|w| w == key) {
-            let s = from + p + key.len();
-            let e = ps[s..].iter().position(|c| matches!(c, b'\n' | b'\r')).map_or(ps.len(), |q| s + q);
-            let v: Vec<f64> = String::from_utf8_lossy(&ps[s..e]).split_whitespace().filter_map(|t| t.parse().ok()).collect();
-            if v.len() == 4 && v[2] > v[0] && v[3] > v[1] {
-                return Some([v[0], v[1], v[2], v[3]]);
-            }
-            from = s;
-        }
-        None
-    };
-    let bbox = find_box(b"%%HiResBoundingBox:").or_else(|| find_box(b"%%BoundingBox:"))?;
-    Some((ps, bbox))
-}
-
-// ------------------------------------------------------------------ text
-
-/// An encoding array of glyph names (`StandardEncoding`; `ISOLatin1Encoding` and others are
-/// approximated by WinAnsi, which agrees with ISO Latin-1 on the printable codes).
-fn encoding_array(name: &str) -> V {
-    let base = if name == "StandardEncoding" { crate::encoding::Base::Standard } else { crate::encoding::Base::WinAnsi };
-    array((0..256).map(|c| V::Lit(base.name(c as u8).unwrap_or_else(|| ".notdef".into()).into())).collect())
-}
-
-fn find_from(hay: &[u8], needle: &[u8], from: usize) -> Option<usize> {
-    hay.get(from..)?.windows(needle.len()).position(|w| w == needle).map(|p| p + from)
-}
-
-fn rfind_before(hay: &[u8], needle: &[u8], to: usize) -> Option<usize> {
-    hay.get(..to)?.windows(needle.len()).rposition(|w| w == needle)
-}
-
-/// The name after `key` (`/FontName /Name`).
-fn name_after(b: &[u8], key: &[u8]) -> Option<String> {
-    let p = find_from(b, key, 0)? + key.len();
-    let rest = &b[p..];
-    let s = rest.iter().position(|c| *c == b'/')? + 1;
-    let e = rest[s..].iter().position(|c| is_white(*c) || matches!(c, b'/' | b'[' | b'(' | b'{')).map_or(rest.len(), |q| s + q);
-    (e > s).then(|| String::from_utf8_lossy(&rest[s..e]).into_owned())
-}
-
-/// Embedded font programs of an EPS file: Type 1 fonts (`… /FontName /X … currentfile eexec
-/// … cleartomark`, hexadecimal or binary) and CFF font sets (`… <length> StartData <bytes>`).
-fn embedded_fonts(ps: &[u8]) -> HashMap<String, (Rc<Vec<u8>>, bool)> {
-    let mut out = HashMap::new();
-    let mut from = 0;
-    while let Some(ee) = find_from(ps, b"eexec", from) {
-        from = ee + 5;
-        let start = [b"%!PS-AdobeFont".as_slice(), b"%!FontType1"]
-            .iter()
-            .filter_map(|h| rfind_before(ps, h, ee))
-            .max()
-            .or_else(|| rfind_before(ps, b"/FontName", ee).map(|p| p.saturating_sub(512)));
-        let Some(start) = start else { continue };
-        let end = find_from(ps, b"cleartomark", ee).map_or(ps.len(), |p| p + 11);
-        if let Some(name) = name_after(&ps[start..ee], b"/FontName") {
-            out.insert(name, (Rc::new(ps[start..end].to_vec()), false));
-        }
-        from = end;
-    }
-    let mut from = 0;
-    while let Some(sd) = find_from(ps, b"StartData", from) {
-        from = sd + 9;
-        let head = String::from_utf8_lossy(&ps[sd.saturating_sub(64)..sd]).into_owned();
-        let Some(len) = head.split_whitespace().last().and_then(|t| t.parse::<usize>().ok()) else { continue };
-        let s = sd + 10;
-        let Some(data) = ps.get(s..s.saturating_add(len)) else { continue };
-        if let Some(name) = crate::cff::font_name(data) {
-            out.insert(name, (Rc::new(data.to_vec()), true));
-        }
-        from = s + len;
-    }
-    out
-}
-
-fn dict_matrix(d: &DictRef, key: &str) -> Affine {
-    d.borrow().get(key).and_then(matrix_of).unwrap_or(Affine::IDENTITY)
-}
-
-/// A copy of a font dictionary with `m` applied after its matrix (`scalefont`, `makefont`).
-fn transformed(font: &DictRef, m: Affine) -> DictRef {
-    let copy: HashMap<String, V> = font.borrow().clone();
-    let d = Rc::new(RefCell::new(copy));
-    let old = dict_matrix(&d, "__m");
-    d.borrow_mut().insert("__m".into(), matrix_val(m * old));
-    d
-}
-
-impl Interp {
-    /// A font dictionary by name: one `definefont` made, else a new dictionary for an
-    /// embedded program or a bundled stand-in.
-    fn find_font(&mut self, key: &str) -> DictRef {
-        if let Some(d) = self.font_dir.get(key) {
-            return d.clone();
-        }
-        let d = new_dict();
-        {
-            let mut m = d.borrow_mut();
-            m.insert("FontName".into(), V::Lit(key.into()));
-            m.insert("FontType".into(), V::Num(1.0));
-            m.insert("FontMatrix".into(), matrix_val(Affine::scale(0.001)));
-            m.insert("FID".into(), V::Null);
-            m.insert("__base".into(), V::Lit(key.into()));
-            m.insert("__m".into(), matrix_val(Affine::IDENTITY));
-        }
-        self.font_dir.insert(key.to_string(), d.clone());
-        d
-    }
-
-    /// The drawable font of a font dictionary (its base program and encoding) and the matrix
-    /// from text space (font size 1) to user space.
-    fn font_of(&mut self, d: &DictRef) -> Option<(Rc<Font>, Affine)> {
-        if matches!(d.borrow().get("FontType"), Some(V::Num(t)) if *t == 3.0) {
-            // Type 3 fonts (glyph procedures) are not run.
-            self.b.skip("EPS Type 3 font");
-            return None;
-        }
-        let (base, names) = {
-            let m = d.borrow();
-            let base = m.get("__base").or_else(|| m.get("FontName")).map(V::key)?;
-            let names: Option<Vec<Option<String>>> = m.get("Encoding").and_then(V::items).map(|a| {
-                a.iter()
-                    .map(|v| match v {
-                        V::Lit(n) | V::Name(n) if &**n != ".notdef" => Some(n.to_string()),
-                        _ => None,
-                    })
-                    .collect()
-            });
-            (base, names)
-        };
-        let key = match &names {
-            Some(n) => format!("{base}\u{0}{}", n.iter().map(|x| x.as_deref().unwrap_or("")).collect::<Vec<_>>().join(" ")),
-            None => base.clone(),
-        };
-        let font = match self.font_cache.get(&key) {
-            Some(f) => f.clone(),
-            None => {
-                // Not embedded: a bundled stand-in, as for PDF.
-                let prog = self.embedded.get(&base).cloned();
-                let f = Rc::new(Font::standalone(&base, prog.as_ref().map(|(d, cff)| (d.as_slice(), *cff)), names));
-                self.font_cache.insert(key, f.clone());
-                f
-            }
-        };
-        Some((font, dict_matrix(d, "__m")))
-    }
-
-    /// A string's glyph outlines (device space) from the current point, with an extra
-    /// displacement `extra(index, code)` (user space) after each glyph; moves the current
-    /// point.
-    fn text_path(&mut self, bytes: &[u8], mut extra: impl FnMut(usize, u32) -> (f64, f64)) -> Result<Option<(BezPath, String)>, Flow> {
-        let Some(d) = self.gs.font.clone() else { return Ok(None) };
-        let Some((font, m)) = self.font_of(&d) else { return Ok(None) };
-        let mut p = self.current_user();
-        let mut path = BezPath::new();
-        let mut text = String::new();
-        let ctm = self.gs.ctm;
-        for (i, &code) in bytes.iter().enumerate() {
-            let code = code as u32;
-            if let Some(g) = font.glyph(code) {
-                path.extend(ctm * Affine::translate(p.to_vec2()) * m * (*g).clone());
-            }
-            text.push_str(&font.unicode(code));
-            let adv = m * Point::new(font.width(code), 0.0) - m * Point::ZERO;
-            let (ex, ey) = extra(i, code);
-            p += adv + kurbo::Vec2::new(ex, ey);
-        }
-        self.move_to(p)?;
-        Ok(Some((path, text)))
-    }
-
-    fn fill_text(&mut self, path: BezPath, text: &str) {
-        let label: String = text.chars().filter(|c| !c.is_control()).take(40).collect();
-        let name = if label.trim().is_empty() { "Text".to_string() } else { format!("Text: {}", label.trim()) };
-        self.b.fill_stroke_named(&name, path, Affine::IDENTITY, Some((Paint::Color(self.gs.color), 1.0, FillRule::NonZero)), None);
-    }
-
-    fn pop_string(&mut self) -> Vec<u8> {
-        match self.pop() {
-            V::Str(s) => s.borrow().clone(),
-            _ => vec![],
-        }
-    }
-
-    fn show_with(&mut self, s: &[u8], extra: impl FnMut(usize, u32) -> (f64, f64)) -> Result<(), Flow> {
-        match self.text_path(s, extra)? {
-            Some((path, text)) => self.fill_text(path, &text),
-            None => self.b.skip("text (no font)"),
-        }
-        Ok(())
-    }
-
-    /// Text and font operators (PostScript Language Reference §5.1, §8.2).
-    fn text_op(&mut self, n: &str, src: &mut Src) -> Result<(), Flow> {
-        match n {
-            "scalefont" | "makefont" => {
-                let m = if n == "scalefont" {
-                    Affine::scale(self.popn())
-                } else {
-                    let v = self.pop();
-                    matrix_of(&v).unwrap_or(Affine::IDENTITY)
-                };
-                let font = match self.pop() {
-                    V::Dict(d) => d,
-                    _ => self.find_font("Helvetica"),
-                };
-                self.push(V::Dict(transformed(&font, m)));
-            }
-            "selectfont" => {
-                let size = self.pop();
-                let key = self.pop().key();
-                let font = self.find_font(&key);
-                let m = match &size {
-                    V::Num(s) => Affine::scale(*s),
-                    other => matrix_of(other).unwrap_or(Affine::IDENTITY),
-                };
-                self.gs.font = Some(transformed(&font, m));
-            }
-            "setfont" => {
-                if let V::Dict(d) = self.pop() {
-                    self.gs.font = Some(d);
-                }
-            }
-            "currentfont" | "rootfont" => {
-                let d = self.gs.font.clone().unwrap_or_else(new_dict);
-                self.push(V::Dict(d));
-            }
-            "definefont" => {
-                let v = self.pop();
-                let key = self.pop().key();
-                if let V::Dict(d) = &v {
-                    if !d.borrow().contains_key("__base") {
-                        // A font the file defines itself: its embedded program, by name.
-                        d.borrow_mut().insert("__base".into(), V::Lit(key.as_str().into()));
-                        d.borrow_mut().insert("__m".into(), matrix_val(Affine::IDENTITY));
-                    }
-                    self.font_dir.insert(key, d.clone());
-                }
-                self.push(v);
-            }
-            "undefinefont" => {
-                let key = self.pop().key();
-                self.font_dir.remove(&key);
-            }
-            "StandardEncoding" | "ISOLatin1Encoding" => self.push(encoding_array(n)),
-            "show" => {
-                let s = self.pop_string();
-                self.show_with(&s, |_, _| (0.0, 0.0))?;
-            }
-            "ashow" => {
-                let s = self.pop_string();
-                let ay = self.popn();
-                let ax = self.popn();
-                self.show_with(&s, |_, _| (ax, ay))?;
-            }
-            "widthshow" => {
-                let s = self.pop_string();
-                let ch = self.popn() as u32;
-                let cy = self.popn();
-                let cx = self.popn();
-                self.show_with(&s, |_, c| if c == ch { (cx, cy) } else { (0.0, 0.0) })?;
-            }
-            "awidthshow" => {
-                let s = self.pop_string();
-                let ay = self.popn();
-                let ax = self.popn();
-                let ch = self.popn() as u32;
-                let cy = self.popn();
-                let cx = self.popn();
-                self.show_with(&s, |_, c| if c == ch { (cx + ax, cy + ay) } else { (ax, ay) })?;
-            }
-            "kshow" | "cshow" => {
-                // The procedure between characters is not run.
-                let s = self.pop_string();
-                self.pop();
-                self.show_with(&s, |_, _| (0.0, 0.0))?;
-            }
-            "xshow" | "yshow" | "xyshow" => {
-                let disp: Vec<f64> = self.pop().items().unwrap_or_default().iter().filter_map(V::num).collect();
-                let s = self.pop_string();
-                self.explicit_show(&s, &disp, n)?;
-            }
-            "glyphshow" => {
-                let name = self.pop().key();
-                let Some(d) = self.gs.font.clone() else { return Ok(()) };
-                // Drawn through a one-glyph encoding.
-                let mut e: Vec<V> = (0..256).map(|_| V::Lit(".notdef".into())).collect();
-                e[65] = V::Lit(name.as_str().into());
-                let tmp = transformed(&d, Affine::IDENTITY);
-                tmp.borrow_mut().insert("Encoding".into(), array(e));
-                self.gs.font = Some(tmp);
-                self.show_with(b"A", |_, _| (0.0, 0.0))?;
-                self.gs.font = Some(d);
-            }
-            "charpath" => {
-                self.pop();
-                let s = self.pop_string();
-                let saved = std::mem::take(&mut self.gs.path);
-                let start = self.gs.start;
-                match self.text_path(&s, |_, _| (0.0, 0.0))? {
-                    Some((glyphs, _)) => {
-                        // The outlines join the path: each element counts against the budget and
-                        // the path limit.
-                        self.gs.path = saved;
-                        self.room(glyphs.elements().len() + 1)?;
-                        self.spend(glyphs.elements().len())?;
-                        self.gs.path.extend(glyphs);
-                        if let Some(c) = self.gs.cur {
-                            self.gs.path.move_to(c);
-                        }
-                        self.gs.start = start;
-                    }
-                    None => self.gs.path = saved,
-                }
-            }
-            "stringwidth" => {
-                let s = self.pop_string();
-                let (mut w, mut h) = (0.0, 0.0);
-                if let Some(d) = self.gs.font.clone()
-                    && let Some((font, m)) = self.font_of(&d)
-                {
-                    for &c in &s {
-                        let v = m * Point::new(font.width(c as u32), 0.0) - m * Point::ZERO;
-                        w += v.x;
-                        h += v.y;
-                    }
-                }
-                self.push(V::Num(w));
-                self.push(V::Num(h));
-            }
-            "setcachedevice" => {
-                for _ in 0..6 {
-                    self.pop();
-                }
-            }
-            "setcharwidth" => {
-                self.pop();
-                self.pop();
-            }
-            // An embedded Type 1 program's encrypted part (read by `embedded_fonts`).
-            "eexec" => {
-                if matches!(self.pop(), V::File) {
-                    let rest = &src.d[src.pos.min(src.d.len())..];
-                    src.pos += rest.windows(11).position(|w| w == b"cleartomark").map_or(rest.len(), |p| p + 11);
-                }
-            }
-            // A CFF font set's binary data (read by `embedded_fonts`).
-            "StartData" => {
-                let len = self.popn().max(0.0) as usize;
-                self.pop();
-                src.pos = src.pos.saturating_add(1).saturating_add(len).min(src.d.len());
-            }
-            _ => {}
-        }
-        Ok(())
-    }
-
-    /// `xshow` / `yshow` / `xyshow`: glyph displacements from a number array instead of the
-    /// advances.
-    fn explicit_show(&mut self, s: &[u8], disp: &[f64], n: &str) -> Result<(), Flow> {
-        let step = if n == "xyshow" { 2 } else { 1 };
-        let d: Vec<(f64, f64)> = (0..s.len())
-            .map(|k| {
-                let i = k * step;
-                let v = |j: usize| disp.get(j).copied().unwrap_or(0.0);
-                match n {
-                    "xshow" => (v(i), 0.0),
-                    "yshow" => (0.0, v(i)),
-                    _ => (v(i), v(i + 1)),
-                }
-            })
-            .collect();
-        let Some(fd) = self.gs.font.clone() else {
-            self.b.skip("text (no font)");
-            return Ok(());
-        };
-        let Some((font, m)) = self.font_of(&fd) else { return Ok(()) };
-        self.show_with(s, move |k, c| {
-            let adv = m * Point::new(font.width(c), 0.0) - m * Point::ZERO;
-            let (dx, dy) = d.get(k).copied().unwrap_or((0.0, 0.0));
-            (dx - adv.x, dy - adv.y)
-        })
-    }
-}
diff --git a/crates/pdf/src/ps/builtin.rs b/crates/pdf/src/ps/builtin.rs
new file mode 100644
index 000000000..dcafa9417
--- /dev/null
+++ b/crates/pdf/src/ps/builtin.rs
@@ -0,0 +1,1066 @@
+use super::eps::find_from;
+use super::scanner::Src;
+use super::text::encoding_array;
+use super::value::{Flow, V, array, matrix_of, matrix_val, new_dict};
+use super::{Affine, BezPath, Cap, FillRule, Interp, Join, PathEl, Point, Rc, RefCell, parse_num};
+
+impl Interp {
+    pub(super) fn builtin(&mut self, n: &str, src: &mut Src) -> Result<(), Flow> {
+        // Every handler leaves the stacks untouched when the operator is outside its family.
+        if self.try_stack_op(n)
+            || self.try_arithmetic_op(n)
+            || self.try_logic_op(n)
+            || self.try_control_op(n, src)?
+            || self.try_dictionary_op(n)
+            || self.try_collection_op(n)
+            || self.try_environment_op(n, src)?
+            || self.try_graphics_op(n)?
+            || self.try_coordinate_op(n)
+            || self.try_path_op(n)?
+            || self.try_paint_op(n)?
+        {
+            return Ok(());
+        }
+        match n {
+            // Text (see `text_op`).
+            "scalefont" | "makefont" | "selectfont" | "setfont" | "show" | "charpath" | "glyphshow" | "rootfont" | "currentfont" | "setcachedevice"
+            | "setcharwidth" | "ashow" | "widthshow" | "awidthshow" | "xshow" | "yshow" | "xyshow" | "kshow" | "cshow" | "stringwidth" | "definefont"
+            | "StandardEncoding" | "ISOLatin1Encoding" | "eexec" | "StartData" | "undefinefont" => self.text_op(n, src)?,
+            // Images: operands popped, inline data skipped.
+            "image" | "imagemask" | "colorimage" => {
+                let mut reads_file = false;
+                let check = |v: &V, rf: &mut bool| {
+                    if matches!(v, V::File) || matches!(v, V::Proc(p) if p.iter().any(|x| matches!(x, V::Name(n) if &**n == "currentfile"))) {
+                        *rf = true;
+                    }
+                };
+                if n == "colorimage" {
+                    let ncomp = self.popn().max(1.0) as usize;
+                    let multi = matches!(self.pop(), V::Bool(true));
+                    for _ in 0..if multi { ncomp.min(4) } else { 1 } {
+                        let v = self.pop();
+                        check(&v, &mut reads_file);
+                    }
+                    for _ in 0..4 {
+                        self.pop();
+                    }
+                } else {
+                    match self.pop() {
+                        V::Dict(d) => {
+                            if let Some(ds) = d.borrow().get("DataSource") {
+                                check(ds, &mut reads_file);
+                            }
+                        }
+                        top => {
+                            check(&top, &mut reads_file);
+                            for _ in 0..4 {
+                                self.pop();
+                            }
+                        }
+                    }
+                }
+                if reads_file {
+                    src.skip_image_data();
+                }
+                self.b.skip("image");
+            }
+            _ => {
+                if self.unknown.len() < 32 && !self.unknown.iter().any(|u| u == n) {
+                    self.unknown.push(n.to_string());
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn repeat_proc(&mut self, src: &mut Src) -> Result<(), Flow> {
+        let p = self.pop();
+        let k = self.popn().clamp(0.0, 1e6) as usize;
+        for _ in 0..k {
+            self.spend(1)?;
+            match self.exec_obj(p.clone(), src) {
+                Err(Flow::Exit) => break,
+                r => r?,
+            }
+        }
+
+        Ok(())
+    }
+
+    fn for_proc(&mut self, src: &mut Src) -> Result<(), Flow> {
+        let p = self.pop();
+        let lim = self.popn();
+        let inc = self.popn();
+        let mut i = self.popn();
+        let mut guard = 0;
+        while inc != 0.0 && ((inc > 0.0 && i <= lim) || (inc < 0.0 && i >= lim)) && guard < 1_000_000 {
+            self.spend(1)?;
+            self.push(V::Num(i));
+            match self.exec_obj(p.clone(), src) {
+                Err(Flow::Exit) => break,
+                r => r?,
+            }
+            i += inc;
+            guard += 1;
+        }
+
+        Ok(())
+    }
+
+    fn loop_proc(&mut self, src: &mut Src) -> Result<(), Flow> {
+        let p = self.pop();
+        for _ in 0..1_000_000 {
+            self.spend(1)?;
+            match self.exec_obj(p.clone(), src) {
+                Err(Flow::Exit) => break,
+                r => r?,
+            }
+        }
+
+        Ok(())
+    }
+
+    fn forall_proc(&mut self, src: &mut Src) -> Result<(), Flow> {
+        let p = self.pop();
+        match self.pop() {
+            V::Dict(d) => {
+                let items: Vec<(String, V)> = d.borrow().iter().map(|(k, v)| (k.clone(), v.clone())).collect();
+                for (k, v) in items {
+                    self.spend(1)?;
+                    self.push(V::Lit(k.into()));
+                    self.push(v);
+                    match self.exec_obj(p.clone(), src) {
+                        Err(Flow::Exit) => break,
+                        r => r?,
+                    }
+                }
+            }
+            V::Str(s) => {
+                let bytes = s.borrow().clone();
+                for c in bytes {
+                    self.spend(1)?;
+                    self.push(V::Num(c as f64));
+                    match self.exec_obj(p.clone(), src) {
+                        Err(Flow::Exit) => break,
+                        r => r?,
+                    }
+                }
+            }
+            a => {
+                for v in a.items().unwrap_or_default() {
+                    self.spend(1)?;
+                    self.push(v);
+                    match self.exec_obj(p.clone(), src) {
+                        Err(Flow::Exit) => break,
+                        r => r?,
+                    }
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    fn try_stack_op(&mut self, n: &str) -> bool {
+        match n {
+            // Stack.
+            "pop" => {
+                self.pop();
+            }
+            "exch" => {
+                let b = self.pop();
+                let a = self.pop();
+                self.push(b);
+                self.push(a);
+            }
+            "dup" => {
+                let a = self.st.last().cloned().unwrap_or(V::Null);
+                self.push(a);
+            }
+            "copy" => {
+                match self.pop() {
+                    V::Num(k) => {
+                        let k = (k.max(0.0) as usize).min(self.st.len());
+                        let tail: Vec<V> = self.st[self.st.len() - k..].to_vec();
+                        self.st.extend(tail);
+                    }
+                    V::Array(dst) => {
+                        let s = self.pop().items().unwrap_or_default();
+                        let mut d = dst.borrow_mut();
+                        for (i, v) in s.into_iter().enumerate() {
+                            if i < d.len() {
+                                d[i] = v;
+                            }
+                        }
+                        drop(d);
+                        self.push(V::Array(dst));
+                    }
+                    other => self.push(other),
+                };
+            }
+            "index" => {
+                let k = self.popn().max(0.0) as usize;
+                let v = if k < self.st.len() { self.st[self.st.len() - 1 - k].clone() } else { V::Null };
+                self.push(v);
+            }
+            "roll" => {
+                let j = self.popn() as i64;
+                let k = (self.popn().max(0.0) as usize).min(self.st.len());
+                if k > 0 {
+                    let s = self.st.len() - k;
+                    let r = j.rem_euclid(k as i64) as usize;
+                    self.st[s..].rotate_right(r);
+                }
+            }
+            "clear" => self.st.clear(),
+            "count" => self.push(V::Num(self.st.len() as f64)),
+            "mark" | "[" | "<<" => self.push(V::Mark),
+            "cleartomark" => {
+                while let Some(v) = self.st.pop() {
+                    if matches!(v, V::Mark) {
+                        break;
+                    }
+                }
+            }
+            "counttomark" => {
+                let k = self.st.iter().rev().position(|v| matches!(v, V::Mark)).unwrap_or(self.st.len());
+                self.push(V::Num(k as f64));
+            }
+            "]" => {
+                let k = self.st.iter().rev().position(|v| matches!(v, V::Mark)).unwrap_or(self.st.len());
+                let items = self.st.split_off(self.st.len() - k);
+                self.st.pop();
+                self.push(array(items));
+            }
+            ">>" => {
+                let k = self.st.iter().rev().position(|v| matches!(v, V::Mark)).unwrap_or(self.st.len());
+                let items = self.st.split_off(self.st.len() - k);
+                self.st.pop();
+                let d = new_dict();
+                for kv in items.as_chunks::<2>().0 {
+                    d.borrow_mut().insert(kv[0].key(), kv[1].clone());
+                }
+                self.push(V::Dict(d));
+            }
+            _ => return false,
+        }
+        true
+    }
+
+    fn try_arithmetic_op(&mut self, n: &str) -> bool {
+        match n {
+            // Arithmetic.
+            "add" | "sub" | "mul" | "div" | "idiv" | "mod" | "atan" | "exp" | "max" | "min" => {
+                let b = self.popn();
+                let a = self.popn();
+                let v = match n {
+                    "add" => a + b,
+                    "sub" => a - b,
+                    "mul" => a * b,
+                    "div" => {
+                        if b == 0.0 {
+                            0.0
+                        } else {
+                            a / b
+                        }
+                    }
+                    // `checked_*` give 0 both for a zero divisor and for the one overflowing
+                    // case, `i64::MIN / -1` (`/` and `%` panic on it in every build).
+                    "idiv" => (a as i64).checked_div(b as i64).unwrap_or(0) as f64,
+                    "mod" => (a as i64).checked_rem(b as i64).unwrap_or(0) as f64,
+                    "atan" => a.atan2(b).to_degrees().rem_euclid(360.0),
+                    "exp" => a.powf(b),
+                    "max" => a.max(b),
+                    _ => a.min(b),
+                };
+                self.push(V::Num(if v.is_finite() { v } else { 0.0 }));
+            }
+            "neg" | "abs" | "sqrt" | "sin" | "cos" | "ln" | "log" | "cvi" | "cvr" | "round" | "floor" | "ceiling" | "truncate" => {
+                let a = match self.pop() {
+                    V::Str(s) => parse_num(&s.borrow()).unwrap_or(0.0),
+                    v => v.num().unwrap_or(0.0),
+                };
+                let v = match n {
+                    "neg" => -a,
+                    "abs" => a.abs(),
+                    "sqrt" => a.max(0.0).sqrt(),
+                    "sin" => a.to_radians().sin(),
+                    "cos" => a.to_radians().cos(),
+                    "ln" => a.ln(),
+                    "log" => a.log10(),
+                    "cvi" | "truncate" => a.trunc(),
+                    "round" => (a + 0.5).floor(),
+                    "floor" => a.floor(),
+                    "ceiling" => a.ceil(),
+                    _ => a,
+                };
+                self.push(V::Num(if v.is_finite() { v } else { 0.0 }));
+            }
+            _ => return false,
+        }
+        true
+    }
+
+    fn try_logic_op(&mut self, n: &str) -> bool {
+        match n {
+            // Comparison and logic.
+            "eq" | "ne" => {
+                let b = self.pop();
+                let a = self.pop();
+                let eq = match (&a, &b) {
+                    (V::Num(x), V::Num(y)) => x == y,
+                    (V::Bool(x), V::Bool(y)) => x == y,
+                    (V::Null, V::Null) => true,
+                    (V::Array(x), V::Array(y)) => Rc::ptr_eq(x, y),
+                    (V::Dict(x), V::Dict(y)) => Rc::ptr_eq(x, y),
+                    (x, y) => !x.key().is_empty() && x.key() == y.key(),
+                };
+                self.push(V::Bool(eq == (n == "eq")));
+            }
+            "gt" | "ge" | "lt" | "le" => {
+                let b = self.popn();
+                let a = self.popn();
+                self.push(V::Bool(match n {
+                    "gt" => a > b,
+                    "ge" => a >= b,
+                    "lt" => a < b,
+                    _ => a <= b,
+                }));
+            }
+            "not" => match self.pop() {
+                V::Bool(b) => self.push(V::Bool(!b)),
+                v => self.push(V::Num(!(v.num().unwrap_or(0.0) as i64) as f64)),
+            },
+            "and" | "or" | "xor" => {
+                let b = self.pop();
+                let a = self.pop();
+                match (a, b) {
+                    (V::Bool(x), V::Bool(y)) => self.push(V::Bool(match n {
+                        "and" => x && y,
+                        "or" => x || y,
+                        _ => x ^ y,
+                    })),
+                    (x, y) => {
+                        let (x, y) = (x.num().unwrap_or(0.0) as i64, y.num().unwrap_or(0.0) as i64);
+                        self.push(V::Num(match n {
+                            "and" => x & y,
+                            "or" => x | y,
+                            _ => x ^ y,
+                        } as f64));
+                    }
+                }
+            }
+            "true" => self.push(V::Bool(true)),
+            "false" => self.push(V::Bool(false)),
+            "null" => self.push(V::Null),
+            _ => return false,
+        }
+        true
+    }
+
+    fn try_control_op(&mut self, n: &str, src: &mut Src) -> Result<bool, Flow> {
+        match n {
+            // Control.
+            "exec" => {
+                let v = self.pop();
+                self.exec_obj(v, src)?;
+            }
+            "if" => {
+                let p = self.pop();
+                if let V::Bool(true) = self.pop() {
+                    self.exec_obj(p, src)?;
+                }
+            }
+            "ifelse" => {
+                let f = self.pop();
+                let t = self.pop();
+                let c = matches!(self.pop(), V::Bool(true));
+                self.exec_obj(if c { t } else { f }, src)?;
+            }
+            // Each pass of a loop counts against the budget.
+            "repeat" => self.repeat_proc(src)?,
+            "for" => self.for_proc(src)?,
+            "loop" => self.loop_proc(src)?,
+            "forall" => self.forall_proc(src)?,
+            "exit" => return Err(Flow::Exit),
+            "stop" => return Err(Flow::Stop),
+            "stopped" => {
+                let p = self.pop();
+                let stopped = match self.exec_obj(p, src) {
+                    Err(Flow::Quit) => return Err(Flow::Quit),
+                    Err(_) => true,
+                    Ok(()) => false,
+                };
+                self.push(V::Bool(stopped));
+            }
+            "quit" => return Err(Flow::Quit),
+            "showpage" | "copypage" => {}
+            _ => return Ok(false),
+        }
+        Ok(true)
+    }
+
+    fn try_dictionary_op(&mut self, n: &str) -> bool {
+        match n {
+            // Dictionaries.
+            "def" => {
+                let v = self.pop();
+                let k = self.pop().key();
+                if let Some(d) = self.dicts.last() {
+                    d.borrow_mut().insert(k, v);
+                }
+            }
+            "store" => {
+                let v = self.pop();
+                let k = self.pop().key();
+                let d = self.dicts.iter().rev().find(|d| d.borrow().contains_key(&k)).or(self.dicts.last()).cloned();
+                if let Some(d) = d {
+                    d.borrow_mut().insert(k, v);
+                }
+            }
+            "load" => {
+                let k = self.pop().key();
+                let v = self.lookup(&k).unwrap_or(V::Op(k.into()));
+                self.push(v);
+            }
+            "undef" => {
+                let k = self.pop().key();
+                if let V::Dict(d) = self.pop() {
+                    d.borrow_mut().remove(&k);
+                }
+            }
+            "dict" => {
+                self.pop();
+                self.push(V::Dict(new_dict()));
+            }
+            "begin" => {
+                if let V::Dict(d) = self.pop()
+                    && self.dicts.len() < 64
+                {
+                    self.dicts.push(d);
+                }
+            }
+            "end" => {
+                if self.dicts.len() > 1 {
+                    self.dicts.pop();
+                }
+            }
+            "currentdict" => {
+                let d = self.dicts.last().cloned().unwrap_or_else(new_dict);
+                self.push(V::Dict(d));
+            }
+            "userdict" | "globaldict" | "systemdict" | "statusdict" | "errordict" | "$error" => {
+                let d = self.dicts[0].clone();
+                self.push(V::Dict(d));
+            }
+            "where" => {
+                let k = self.pop().key();
+                match self.dicts.iter().rev().find(|d| d.borrow().contains_key(&k)).cloned() {
+                    Some(d) => {
+                        self.push(V::Dict(d));
+                        self.push(V::Bool(true));
+                    }
+                    None => self.push(V::Bool(false)),
+                }
+            }
+            "known" => {
+                let k = self.pop().key();
+                let v = match self.pop() {
+                    V::Dict(d) => d.borrow().contains_key(&k),
+                    _ => false,
+                };
+                self.push(V::Bool(v));
+            }
+            "countdictstack" => self.push(V::Num(self.dicts.len() as f64)),
+            "cleardictstack" => self.dicts.truncate(1),
+            "findresource" | "findfont" | "findencoding" => {
+                let category = if n == "findresource" { self.pop().key() } else { String::new() };
+                let key = self.pop().key();
+                match (n, category.as_str()) {
+                    ("findfont", _) | (_, "Font") => {
+                        let f = self.find_font(&key);
+                        self.push(V::Dict(f));
+                    }
+                    ("findencoding", _) | (_, "Encoding") => self.push(encoding_array(&key)),
+                    _ => self.push(V::Dict(new_dict())),
+                }
+            }
+            "defineresource" => {
+                let category = self.pop().key();
+                let v = self.pop();
+                let key = self.pop().key();
+                if let (V::Dict(d), "Font") = (&v, category.as_str()) {
+                    self.font_dir.insert(key, d.clone());
+                }
+                self.push(v);
+            }
+            "resourcestatus" => {
+                self.pop();
+                self.pop();
+                self.push(V::Bool(false));
+            }
+            _ => return false,
+        }
+        true
+    }
+
+    fn try_collection_op(&mut self, n: &str) -> bool {
+        match n {
+            // Arrays and strings.
+            "array" => {
+                let k = self.popn().clamp(0.0, 1e6) as usize;
+                self.push(array(vec![V::Null; k]));
+            }
+            "string" => {
+                let k = self.popn().clamp(0.0, 1e7) as usize;
+                self.push(V::Str(Rc::new(RefCell::new(vec![0; k]))));
+            }
+            "length" => {
+                let l = match self.pop() {
+                    V::Str(s) => s.borrow().len(),
+                    V::Dict(d) => d.borrow().len(),
+                    V::Name(s) | V::Lit(s) => s.len(),
+                    v => v.items().map_or(0, |i| i.len()),
+                };
+                self.push(V::Num(l as f64));
+            }
+            "get" => {
+                let k = self.pop();
+                let v = match self.pop() {
+                    V::Dict(d) => d.borrow().get(&k.key()).cloned().unwrap_or(V::Null),
+                    V::Str(s) => V::Num(s.borrow().get(k.num().unwrap_or(0.0) as usize).copied().unwrap_or(0) as f64),
+                    a => a.items().and_then(|i| i.get(k.num().unwrap_or(0.0) as usize).cloned()).unwrap_or(V::Null),
+                };
+                self.push(v);
+            }
+            "put" => {
+                let v = self.pop();
+                let k = self.pop();
+                match self.pop() {
+                    V::Dict(d) => {
+                        d.borrow_mut().insert(k.key(), v);
+                    }
+                    V::Array(a) => {
+                        let i = k.num().unwrap_or(0.0) as usize;
+                        if let Some(slot) = a.borrow_mut().get_mut(i) {
+                            *slot = v;
+                        }
+                    }
+                    V::Str(s) => {
+                        let i = k.num().unwrap_or(0.0) as usize;
+                        if let Some(slot) = s.borrow_mut().get_mut(i) {
+                            *slot = v.num().unwrap_or(0.0) as u8;
+                        }
+                    }
+                    _ => {}
+                }
+            }
+            "getinterval" => {
+                let c = self.popn().max(0.0) as usize;
+                let i = self.popn().max(0.0) as usize;
+                match self.pop() {
+                    V::Str(s) => {
+                        let b = s.borrow();
+                        let part = b.get(i.min(b.len())..(i + c).min(b.len())).unwrap_or(&[]).to_vec();
+                        drop(b);
+                        self.push(V::Str(Rc::new(RefCell::new(part))));
+                    }
+                    a => {
+                        let items = a.items().unwrap_or_default();
+                        let part = items.get(i.min(items.len())..(i + c).min(items.len())).unwrap_or(&[]).to_vec();
+                        self.push(array(part));
+                    }
+                }
+            }
+            "putinterval" => {
+                self.pop();
+                self.pop();
+                self.pop();
+            }
+            "aload" => {
+                let a = self.pop();
+                for v in a.items().unwrap_or_default() {
+                    self.push(v);
+                }
+                self.push(a);
+            }
+            "astore" => {
+                let a = self.pop();
+                if let V::Array(arr) = &a {
+                    let k = arr.borrow().len().min(self.st.len());
+                    let items = self.st.split_off(self.st.len() - k);
+                    *arr.borrow_mut() = items;
+                }
+                self.push(a);
+            }
+            "cvx" => match self.pop() {
+                V::Array(a) => self.push(V::Proc(Rc::new(a.borrow().clone()))),
+                V::Lit(s) => self.push(V::Name(s)),
+                V::Str(s) => {
+                    // Executable string: tokenize it as a procedure.
+                    let bytes = s.borrow().clone();
+                    let mut sub = Src { d: &bytes, pos: 0 };
+                    let mut body = vec![];
+                    while let Some(t) = sub.token(0) {
+                        body.push(t);
+                    }
+                    self.push(V::Proc(Rc::new(body)));
+                }
+                v => self.push(v),
+            },
+            "cvlit" => match self.pop() {
+                V::Proc(p) => self.push(array(p.as_ref().clone())),
+                V::Name(s) => self.push(V::Lit(s)),
+                v => self.push(v),
+            },
+            "cvn" => {
+                let k = self.pop().key();
+                self.push(V::Lit(k.into()));
+            }
+            "cvs" => {
+                self.pop();
+                let k = self.pop().key();
+                self.push(V::Str(Rc::new(RefCell::new(k.into_bytes()))));
+            }
+            "xcheck" => {
+                let v = self.pop();
+                self.push(V::Bool(matches!(v, V::Proc(_) | V::Name(_) | V::Op(_))));
+            }
+            "type" => {
+                let t = match self.pop() {
+                    V::Num(_) => "realtype",
+                    V::Bool(_) => "booleantype",
+                    V::Name(_) | V::Lit(_) => "nametype",
+                    V::Op(_) => "operatortype",
+                    V::Str(_) => "stringtype",
+                    V::Proc(_) | V::Array(_) => "arraytype",
+                    V::Dict(_) => "dicttype",
+                    V::Mark => "marktype",
+                    V::Null => "nulltype",
+                    V::File => "filetype",
+                };
+                self.push(V::Name(t.into()));
+            }
+            "bind" | "readonly" | "executeonly" | "noaccess" => {}
+            _ => return false,
+        }
+        true
+    }
+
+    fn try_environment_op(&mut self, n: &str, src: &mut Src) -> Result<bool, Flow> {
+        match n {
+            "languagelevel" => self.push(V::Num(3.0)),
+            "version" | "product" => self.push(V::Str(Rc::new(RefCell::new(b"3010".to_vec())))),
+            "save" => {
+                self.spend(self.gs.path.elements().len())?;
+                self.saved.push(self.gs.clone());
+                self.gs.depth = self.b.depth();
+                self.push(V::Null);
+            }
+            "restore" => {
+                self.pop();
+                self.grestore();
+            }
+            "currentfile" => self.push(V::File),
+            "readstring" | "readhexstring" | "readline" => {
+                self.pop();
+                self.pop();
+                self.push(V::Str(Rc::new(RefCell::new(vec![]))));
+                self.push(V::Bool(false));
+            }
+            "flushfile" | "closefile" | "print" | "==" | "=" | "pstack" | "setpagedevice" | "setglobal" | "setpacking" | "setshared" | "setobjectformat"
+            | "setsmoothness" => {
+                if !matches!(n, "pstack") {
+                    self.pop();
+                }
+            }
+            "currentglobal" | "currentpacking" | "currentshared" => self.push(V::Bool(false)),
+            // Operators that return values must push them, or the rest of the program reads a
+            // shifted stack: Illustrator's EPS prolog queries the device this way and then drew
+            // nothing (#955). Values are a plain device's defaults (PostScript Language
+            // Reference, 3rd ed., chapter 8).
+            "currentflat" => self.push(V::Num(1.0)),
+            "currentscreen" => {
+                self.push(V::Num(60.0));
+                self.push(V::Num(45.0));
+                self.push(V::Proc(Rc::new(vec![])));
+            }
+            "currentblackgeneration" | "currentundercolorremoval" | "currenttransfer" => self.push(V::Proc(Rc::new(vec![]))),
+            "currentcolortransfer" => {
+                for _ in 0..4 {
+                    self.push(V::Proc(Rc::new(vec![])));
+                }
+            }
+            "currentpagedevice" | "currenthalftone" | "currentsystemparams" | "currentuserparams" | "currentdevparams" => {
+                if n == "currentdevparams" {
+                    self.pop();
+                }
+                self.push(V::Dict(new_dict()));
+            }
+            "setuserparams" | "setsystemparams" | "setcolortransfer" | "setblackgeneration" | "setundercolorremoval" => {
+                let k = if n == "setcolortransfer" { 4 } else { 1 };
+                for _ in 0..k {
+                    self.pop();
+                }
+            }
+            // `file status` → false; `string status` → false (no such file).
+            "status" => {
+                self.pop();
+                self.push(V::Bool(false));
+            }
+            "dictstack" => {
+                self.pop();
+                let ds: Vec<V> = self.dicts.iter().map(|d| V::Dict(d.clone())).collect();
+                self.push(array(ds));
+            }
+            "maxlength" => {
+                let k = match self.pop() {
+                    V::Dict(d) => d.borrow().len(),
+                    _ => 0,
+                };
+                self.push(V::Num(k.saturating_add(16) as f64));
+            }
+            "internaldict" => {
+                self.pop();
+                let d = self.dicts[0].clone();
+                self.push(V::Dict(d));
+            }
+            "undefineresource" => {
+                self.pop();
+                self.pop();
+            }
+            // `[ … /Name pdfmark`: a Distiller annotation; other interpreters discard it.
+            "pdfmark" => {
+                while let Some(v) = self.st.pop() {
+                    if matches!(v, V::Mark) {
+                        break;
+                    }
+                }
+            }
+            // `source [params] /Name filter`. A SubFileDecode of the current file with a count of
+            // 0 reads to its end-of-data string: skip that data (an embedded XMP packet, which
+            // otherwise ran as PostScript). Other filters read what their source reads.
+            "filter" => {
+                let name = self.pop().key();
+                let mut skipped = false;
+                let source = if name == "SubFileDecode" && !matches!(self.st.last(), Some(V::Dict(_))) {
+                    let eod = match self.pop() {
+                        V::Str(s) => s.borrow().clone(),
+                        _ => vec![],
+                    };
+                    let count = self.popn();
+                    let source = self.pop();
+                    if matches!(source, V::File) && count == 0.0 && !eod.is_empty() {
+                        src.pos = match find_from(src.d, &eod, src.pos) {
+                            Some(p) => p.saturating_add(eod.len()),
+                            None => src.d.len(),
+                        };
+                        skipped = true;
+                    }
+                    source
+                } else {
+                    if matches!(self.st.last(), Some(V::Dict(_))) {
+                        self.pop();
+                    }
+                    self.pop()
+                };
+                // Data already stepped over leaves nothing for `image` to skip.
+                self.push(if skipped { V::Null } else { source });
+            }
+            "vmstatus" => {
+                for _ in 0..3 {
+                    self.push(V::Num(0.0));
+                }
+            }
+            _ => return Ok(false),
+        }
+        Ok(true)
+    }
+
+    fn try_graphics_op(&mut self, n: &str) -> Result<bool, Flow> {
+        match n {
+            // Graphics state.
+            "gsave" => {
+                self.spend(self.gs.path.elements().len())?;
+                let mut g = self.gs.clone();
+                g.depth = self.b.depth();
+                self.saved.push(g);
+            }
+            "grestore" => self.grestore(),
+            "grestoreall" => {
+                while !self.saved.is_empty() {
+                    self.grestore();
+                }
+            }
+            "initgraphics" => {
+                self.gs.ctm = Affine::IDENTITY;
+                self.gs.lw = 1.0;
+                self.gs.color = [0.0; 3];
+            }
+            "setlinewidth" => self.gs.lw = self.popn(),
+            "currentlinewidth" => self.push(V::Num(self.gs.lw)),
+            "setlinecap" => self.gs.cap = [Cap::Butt, Cap::Round, Cap::Square][(self.popn().max(0.0) as usize).min(2)],
+            "setlinejoin" => self.gs.join = [Join::Miter, Join::Round, Join::Bevel][(self.popn().max(0.0) as usize).min(2)],
+            "setmiterlimit" => self.gs.miter = self.popn(),
+            "setdash" => {
+                let off = self.popn();
+                let a: Vec<f64> = self.pop().items().unwrap_or_default().iter().filter_map(V::num).collect();
+                self.gs.dash = (!a.is_empty() && a.iter().any(|v| *v > 0.0)).then_some((a, off));
+            }
+            "setflat" | "setstrokeadjust" | "setoverprint" | "setrenderingintent" | "setcolorrendering" | "sethalftone" | "settransfer" => {
+                self.pop();
+            }
+            // frequency angle proc
+            "setscreen" => {
+                for _ in 0..3 {
+                    self.pop();
+                }
+            }
+            "setgray" => {
+                let g = self.popn().clamp(0.0, 1.0);
+                self.gs.color = [g; 3];
+            }
+            "setrgbcolor" => {
+                let b = self.popn();
+                let g = self.popn();
+                let r = self.popn();
+                self.gs.color = [r, g, b].map(|v| v.clamp(0.0, 1.0));
+            }
+            "sethsbcolor" => {
+                let v = self.popn().clamp(0.0, 1.0);
+                let s = self.popn().clamp(0.0, 1.0);
+                let h = self.popn().rem_euclid(1.0) * 6.0;
+                let (i, f) = (h.floor() as i32, h.fract());
+                let (p, q, t) = (v * (1.0 - s), v * (1.0 - s * f), v * (1.0 - s * (1.0 - f)));
+                self.gs.color = match i {
+                    0 => [v, t, p],
+                    1 => [q, v, p],
+                    2 => [p, v, t],
+                    3 => [p, q, v],
+                    4 => [t, p, v],
+                    _ => [v, p, q],
+                };
+            }
+            "setcmykcolor" => {
+                let k = self.popn().clamp(0.0, 1.0);
+                let y = self.popn().clamp(0.0, 1.0);
+                let m = self.popn().clamp(0.0, 1.0);
+                let c = self.popn().clamp(0.0, 1.0);
+                self.gs.color = [(1.0 - c) * (1.0 - k), (1.0 - m) * (1.0 - k), (1.0 - y) * (1.0 - k)];
+            }
+            "setcolorspace" => {
+                self.pop();
+            }
+            "setcolor" => {
+                // Device colour by operand count (patterns are not drawn).
+                let k = self.st.iter().rev().take_while(|v| matches!(v, V::Num(_))).count().min(4);
+                let c: Vec<f64> = self.st.split_off(self.st.len() - k).iter().filter_map(V::num).collect();
+                self.gs.color = match c.len() {
+                    1 => [c[0]; 3],
+                    3 => [c[0], c[1], c[2]],
+                    4 => [(1.0 - c[0]) * (1.0 - c[3]), (1.0 - c[1]) * (1.0 - c[3]), (1.0 - c[2]) * (1.0 - c[3])],
+                    _ => self.gs.color,
+                };
+            }
+            "currentgray" => self.push(V::Num((self.gs.color[0] + self.gs.color[1] + self.gs.color[2]) / 3.0)),
+            "currentrgbcolor" => {
+                for c in self.gs.color {
+                    self.push(V::Num(c));
+                }
+            }
+            _ => return Ok(false),
+        }
+        Ok(true)
+    }
+
+    fn try_coordinate_op(&mut self, n: &str) -> bool {
+        match n {
+            // Coordinates.
+            "matrix" => self.push(matrix_val(Affine::IDENTITY)),
+            "identmatrix" | "defaultmatrix" => {
+                self.pop();
+                self.push(matrix_val(Affine::IDENTITY));
+            }
+            "currentmatrix" => {
+                self.pop();
+                self.push(matrix_val(self.gs.ctm));
+            }
+            "setmatrix" => {
+                let m = self.pop();
+                self.gs.ctm = matrix_of(&m).unwrap_or(Affine::IDENTITY);
+            }
+            "concat" => {
+                let m = self.pop();
+                if let Some(m) = matrix_of(&m) {
+                    self.gs.ctm *= m;
+                }
+            }
+            "concatmatrix" => {
+                self.pop();
+                let b = self.pop();
+                let a = self.pop();
+                let (a, b) = (matrix_of(&a).unwrap_or(Affine::IDENTITY), matrix_of(&b).unwrap_or(Affine::IDENTITY));
+                self.push(matrix_val(b * a));
+            }
+            "invertmatrix" => {
+                self.pop();
+                let a = self.pop();
+                self.push(matrix_val(matrix_of(&a).unwrap_or(Affine::IDENTITY).inverse()));
+            }
+            "translate" | "scale" => {
+                let top = self.pop();
+                let (m_out, y) = match top {
+                    V::Array(_) => (Some(top), self.popn()),
+                    v => (None, v.num().unwrap_or(0.0)),
+                };
+                let x = self.popn();
+                let t = if n == "translate" { Affine::translate((x, y)) } else { Affine::scale_non_uniform(x, y) };
+                match m_out {
+                    Some(_) => self.push(matrix_val(t)),
+                    None => self.gs.ctm *= t,
+                }
+            }
+            "rotate" => {
+                let top = self.pop();
+                match top {
+                    V::Array(_) => {
+                        let a = self.popn();
+                        self.push(matrix_val(Affine::rotate(a.to_radians())));
+                    }
+                    v => self.gs.ctm *= Affine::rotate(v.num().unwrap_or(0.0).to_radians()),
+                }
+            }
+            "transform" | "itransform" | "dtransform" | "idtransform" => {
+                let top = self.pop();
+                let (m, y) = match top {
+                    V::Array(_) | V::Proc(_) => (matrix_of(&top).unwrap_or(Affine::IDENTITY), self.popn()),
+                    v => (self.gs.ctm, v.num().unwrap_or(0.0)),
+                };
+                let x = self.popn();
+                let m = if n.starts_with('i') { m.inverse() } else { m };
+                let p = if n.contains('d') {
+                    let c = m.as_coeffs();
+                    Point::new(c[0] * x + c[2] * y, c[1] * x + c[3] * y)
+                } else {
+                    m * Point::new(x, y)
+                };
+                self.push(V::Num(p.x));
+                self.push(V::Num(p.y));
+            }
+            _ => return false,
+        }
+        true
+    }
+
+    fn try_path_op(&mut self, n: &str) -> Result<bool, Flow> {
+        match n {
+            // Paths.
+            "newpath" => {
+                self.gs.path = BezPath::new();
+                self.gs.cur = None;
+                self.gs.start = None;
+            }
+            "moveto" => {
+                let p = self.user_point();
+                self.move_to(p)?;
+            }
+            "rmoveto" => {
+                let d = self.user_point();
+                let c = self.current_user();
+                self.move_to(Point::new(c.x + d.x, c.y + d.y))?;
+            }
+            "lineto" => {
+                let p = self.user_point();
+                self.line_to(p)?;
+            }
+            "rlineto" => {
+                let d = self.user_point();
+                let c = self.current_user();
+                self.line_to(Point::new(c.x + d.x, c.y + d.y))?;
+            }
+            "curveto" | "rcurveto" => {
+                let p3 = self.user_point();
+                let p2 = self.user_point();
+                let p1 = self.user_point();
+                if n == "rcurveto" {
+                    let c = self.current_user();
+                    let o = |p: Point| Point::new(c.x + p.x, c.y + p.y);
+                    self.curve_to(o(p1), o(p2), o(p3))?;
+                } else {
+                    self.curve_to(p1, p2, p3)?;
+                }
+            }
+            "closepath" => {
+                if self.gs.cur.is_some() {
+                    self.room(1)?;
+                    self.gs.path.close_path();
+                    self.gs.cur = self.gs.start;
+                }
+            }
+            "arc" => self.arc(false)?,
+            "arcn" => self.arc(true)?,
+            "currentpoint" => {
+                let c = self.current_user();
+                self.push(V::Num(c.x));
+                self.push(V::Num(c.y));
+            }
+            "pathbbox" => {
+                self.spend(self.gs.path.elements().len())?;
+                let r = kurbo::Shape::bounding_box(&self.gs.path);
+                let inv = self.gs.ctm.inverse();
+                let (a, b) = (inv * Point::new(r.x0, r.y0), inv * Point::new(r.x1, r.y1));
+                for v in [a.x.min(b.x), a.y.min(b.y), a.x.max(b.x), a.y.max(b.y)] {
+                    self.push(V::Num(v));
+                }
+            }
+            "flattenpath" | "reversepath" | "strokepath" | "initclip" => {}
+            "clippath" => {
+                let p = self.page;
+                self.gs.path = kurbo::Shape::to_path(&kurbo::Rect::new(p[0], p[1], p[2], p[3]), 0.1);
+            }
+            _ => return Ok(false),
+        }
+        Ok(true)
+    }
+
+    fn try_paint_op(&mut self, n: &str) -> Result<bool, Flow> {
+        match n {
+            // Painting.
+            "fill" => self.paint(Some(FillRule::NonZero), false),
+            "eofill" => self.paint(Some(FillRule::EvenOdd), false),
+            "stroke" => self.paint(None, true),
+            "clip" | "eoclip" => {
+                let rule = if n == "clip" { FillRule::NonZero } else { FillRule::EvenOdd };
+                self.spend(self.gs.path.elements().len())?;
+                let p = self.gs.path.clone();
+                if !p.elements().iter().all(|e| matches!(e, PathEl::MoveTo(_))) {
+                    self.b.clip(p, rule);
+                }
+            }
+            "rectfill" | "rectstroke" | "rectclip" => {
+                let paths = self.rect_path()?;
+                if n == "rectstroke" && matches!(self.st.last(), Some(V::Array(_))) {
+                    self.pop();
+                }
+                let mut all = BezPath::new();
+                for p in paths {
+                    all.extend(p);
+                }
+                match n {
+                    "rectclip" => self.b.clip(all, FillRule::NonZero),
+                    _ => {
+                        let saved = std::mem::replace(&mut self.gs.path, all);
+                        self.paint(if n == "rectfill" { Some(FillRule::NonZero) } else { None }, n == "rectstroke");
+                        self.gs.path = saved;
+                    }
+                }
+            }
+            "shfill" => {
+                self.pop();
+                self.b.skip("smooth shading (shfill)");
+            }
+            _ => return Ok(false),
+        }
+        Ok(true)
+    }
+}
diff --git a/crates/pdf/src/ps/eps.rs b/crates/pdf/src/ps/eps.rs
new file mode 100644
index 000000000..90d60cfbe
--- /dev/null
+++ b/crates/pdf/src/ps/eps.rs
@@ -0,0 +1,79 @@
+use super::{HashMap, Rc, is_white};
+
+/// The PostScript section of an EPS file (DOS EPS binary header handled) and its bounding box
+/// (`%%HiResBoundingBox` preferred).
+pub fn eps_parts(bytes: &[u8]) -> Option<(&[u8], [f64; 4])> {
+    let ps = if bytes.starts_with(&[0xC5, 0xD0, 0xD3, 0xC6]) && bytes.len() >= 12 {
+        let off = u32::from_le_bytes([bytes[4], bytes[5], bytes[6], bytes[7]]) as usize;
+        let len = u32::from_le_bytes([bytes[8], bytes[9], bytes[10], bytes[11]]) as usize;
+        bytes.get(off..off.checked_add(len)?.min(bytes.len()))?
+    } else {
+        bytes
+    };
+    let find_box = |key: &[u8]| -> Option<[f64; 4]> {
+        let mut from = 0;
+        while let Some(p) = ps[from..].windows(key.len()).position(|w| w == key) {
+            let s = from + p + key.len();
+            let e = ps[s..].iter().position(|c| matches!(c, b'\n' | b'\r')).map_or(ps.len(), |q| s + q);
+            let v: Vec<f64> = String::from_utf8_lossy(&ps[s..e]).split_whitespace().filter_map(|t| t.parse().ok()).collect();
+            if v.len() == 4 && v[2] > v[0] && v[3] > v[1] {
+                return Some([v[0], v[1], v[2], v[3]]);
+            }
+            from = s;
+        }
+        None
+    };
+    let bbox = find_box(b"%%HiResBoundingBox:").or_else(|| find_box(b"%%BoundingBox:"))?;
+    Some((ps, bbox))
+}
+
+pub(super) fn find_from(hay: &[u8], needle: &[u8], from: usize) -> Option<usize> {
+    hay.get(from..)?.windows(needle.len()).position(|w| w == needle).map(|p| p + from)
+}
+
+fn rfind_before(hay: &[u8], needle: &[u8], to: usize) -> Option<usize> {
+    hay.get(..to)?.windows(needle.len()).rposition(|w| w == needle)
+}
+
+/// The name after `key` (`/FontName /Name`).
+fn name_after(b: &[u8], key: &[u8]) -> Option<String> {
+    let p = find_from(b, key, 0)? + key.len();
+    let rest = &b[p..];
+    let s = rest.iter().position(|c| *c == b'/')? + 1;
+    let e = rest[s..].iter().position(|c| is_white(*c) || matches!(c, b'/' | b'[' | b'(' | b'{')).map_or(rest.len(), |q| s + q);
+    (e > s).then(|| String::from_utf8_lossy(&rest[s..e]).into_owned())
+}
+
+/// Embedded font programs of an EPS file: Type 1 fonts (`… /FontName /X … currentfile eexec
+/// … cleartomark`, hexadecimal or binary) and CFF font sets (`… <length> StartData <bytes>`).
+pub(super) fn embedded_fonts(ps: &[u8]) -> HashMap<String, (Rc<Vec<u8>>, bool)> {
+    let mut out = HashMap::new();
+    let mut from = 0;
+    while let Some(ee) = find_from(ps, b"eexec", from) {
+        from = ee + 5;
+        let start = [b"%!PS-AdobeFont".as_slice(), b"%!FontType1"]
+            .iter()
+            .filter_map(|h| rfind_before(ps, h, ee))
+            .max()
+            .or_else(|| rfind_before(ps, b"/FontName", ee).map(|p| p.saturating_sub(512)));
+        let Some(start) = start else { continue };
+        let end = find_from(ps, b"cleartomark", ee).map_or(ps.len(), |p| p + 11);
+        if let Some(name) = name_after(&ps[start..ee], b"/FontName") {
+            out.insert(name, (Rc::new(ps[start..end].to_vec()), false));
+        }
+        from = end;
+    }
+    let mut from = 0;
+    while let Some(sd) = find_from(ps, b"StartData", from) {
+        from = sd + 9;
+        let head = String::from_utf8_lossy(&ps[sd.saturating_sub(64)..sd]).into_owned();
+        let Some(len) = head.split_whitespace().last().and_then(|t| t.parse::<usize>().ok()) else { continue };
+        let s = sd + 10;
+        let Some(data) = ps.get(s..s.saturating_add(len)) else { continue };
+        if let Some(name) = crate::cff::font_name(data) {
+            out.insert(name, (Rc::new(data.to_vec()), true));
+        }
+        from = s + len;
+    }
+    out
+}
diff --git a/crates/pdf/src/ps/exec.rs b/crates/pdf/src/ps/exec.rs
new file mode 100644
index 000000000..27697527c
--- /dev/null
+++ b/crates/pdf/src/ps/exec.rs
@@ -0,0 +1,172 @@
+use super::eps::embedded_fonts;
+use super::scanner::Src;
+use super::value::{Flow, GState, V, new_dict};
+use super::{Affine, BezPath, Builder, Cap, HashMap, Interp, Join};
+
+/// The deepest procedure nesting run (deeper recursion stops the program).
+const MAX_CALL_DEPTH: usize = 256;
+
+impl Interp {
+    pub fn new(page: [f64; 4]) -> Interp {
+        Interp {
+            b: Builder::new(),
+            st: vec![],
+            dicts: vec![new_dict()],
+            gs: GState {
+                ctm: Affine::IDENTITY,
+                color: [0.0; 3],
+                lw: 1.0,
+                cap: Cap::Butt,
+                join: Join::Miter,
+                miter: 10.0,
+                dash: None,
+                path: BezPath::new(),
+                cur: None,
+                start: None,
+                depth: 1,
+                font: None,
+            },
+            saved: vec![],
+            budget: 8_000_000,
+            calls: 0,
+            font_dir: HashMap::new(),
+            embedded: HashMap::new(),
+            font_cache: HashMap::new(),
+            page,
+            unknown: vec![],
+        }
+    }
+
+    pub fn run(&mut self, data: &[u8]) {
+        self.embedded = embedded_fonts(data);
+        let mut src = Src { d: data, pos: 0 };
+        while let Some(t) = src.token(0) {
+            if let Err(Flow::Quit) = self.exec_token(t, &mut src) {
+                break;
+            }
+        }
+    }
+
+    pub(super) fn pop(&mut self) -> V {
+        self.st.pop().unwrap_or(V::Null)
+    }
+
+    pub(super) fn popn(&mut self) -> f64 {
+        self.pop().num().unwrap_or(0.0)
+    }
+
+    pub(super) fn push(&mut self, v: V) {
+        if self.st.len() < 100_000 {
+            self.st.push(v);
+        }
+    }
+
+    pub(super) fn lookup(&self, k: &str) -> Option<V> {
+        self.dicts.iter().rev().find_map(|d| d.borrow().get(k).cloned())
+    }
+
+    /// A token read from the file: procedures are pushed, names executed.
+    fn exec_token(&mut self, t: V, src: &mut Src) -> Result<(), Flow> {
+        match t {
+            V::Name(n) => self.exec_name(&n, src),
+            other => {
+                self.push(other);
+                Ok(())
+            }
+        }
+    }
+
+    /// Execute a value as an object (procedures run).
+    pub(super) fn exec_obj(&mut self, v: V, src: &mut Src) -> Result<(), Flow> {
+        match v {
+            V::Proc(p) => {
+                if self.calls >= MAX_CALL_DEPTH {
+                    self.b.skip("PostScript (recursion limit)");
+                    return Err(Flow::Quit);
+                }
+                self.calls += 1;
+                let mut r = Ok(());
+                for x in p.iter() {
+                    match x {
+                        V::Name(n) => {
+                            r = self.exec_name(n, src);
+                            if r.is_err() {
+                                break;
+                            }
+                        }
+                        V::Op(op) => {
+                            r = self.spend(1).and_then(|()| self.builtin(op, src));
+                            if r.is_err() {
+                                break;
+                            }
+                        }
+                        // Other items count against the budget as names do.
+                        other => {
+                            r = self.spend(1);
+                            if r.is_err() {
+                                break;
+                            }
+                            self.push(other.clone());
+                        }
+                    }
+                }
+                self.calls -= 1;
+                r
+            }
+            // An executable name can run another (`exec` of `/exec cvx`), so names count too.
+            V::Name(n) => {
+                if self.calls >= MAX_CALL_DEPTH {
+                    self.b.skip("PostScript (recursion limit)");
+                    return Err(Flow::Quit);
+                }
+                self.calls += 1;
+                let r = self.exec_name(&n, src);
+                self.calls -= 1;
+                r
+            }
+            V::Op(op) => {
+                self.spend(1)?;
+                self.builtin(&op, src)
+            }
+            other => {
+                self.push(other);
+                Ok(())
+            }
+        }
+    }
+
+    fn exec_name(&mut self, n: &str, src: &mut Src) -> Result<(), Flow> {
+        self.spend(1)?;
+        if let Some(v) = self.lookup(n) {
+            return match v {
+                V::Proc(_) => self.exec_obj(v, src),
+                // An operator stored under another name (`/mo /moveto load def`, as Illustrator's
+                // EPS prolog does for every path operator) runs that operator. It pushed the
+                // operator's name instead, so such files drew nothing (#955).
+                V::Op(op) => self.builtin(&op, src),
+                // An executable name (`/y /x cvx def`) runs what that name is bound to.
+                V::Name(_) => self.exec_obj(v, src),
+                other => {
+                    self.push(other);
+                    Ok(())
+                }
+            };
+        }
+        self.builtin(n, src)
+    }
+
+    /// Count `n` operations against the budget, and stop the program when fewer are left. An
+    /// operator that makes, reads or copies path elements counts each one as an operation.
+    pub(super) fn spend(&mut self, n: usize) -> Result<(), Flow> {
+        match self.budget.checked_sub(n) {
+            Some(left) => {
+                self.budget = left;
+                Ok(())
+            }
+            None => {
+                self.b.skip("PostScript (operation limit)");
+                Err(Flow::Quit)
+            }
+        }
+    }
+}
diff --git a/crates/pdf/src/ps/paths.rs b/crates/pdf/src/ps/paths.rs
new file mode 100644
index 000000000..b1fe07092
--- /dev/null
+++ b/crates/pdf/src/ps/paths.rs
@@ -0,0 +1,187 @@
+use super::value::{Flow, V};
+use super::{Affine, BezPath, FillRule, Interp, MAX_PATH, Paint, PathEl, Point, Stroke};
+
+/// The angle from `a` counterclockwise to `b` (degrees, 0 to 360), worked out from what is left
+/// of each after whole turns.
+fn ccw_turn(a: f64, b: f64) -> f64 {
+    (b % 360.0 - a % 360.0).rem_euclid(360.0)
+}
+
+/// The most turns one `arc` or `arcn` draws.
+const MAX_ARC_TURNS: f64 = 1024.0;
+
+impl Interp {
+    fn device_scale(&self) -> f64 {
+        self.gs.ctm.determinant().abs().sqrt()
+    }
+
+    pub(super) fn user_point(&mut self) -> Point {
+        let y = self.popn();
+        let x = self.popn();
+        Point::new(x, y)
+    }
+
+    /// Stop the program when a path of `len` elements would be longer than [`MAX_PATH`].
+    fn path_fits(&mut self, len: usize) -> Result<(), Flow> {
+        if len <= MAX_PATH {
+            return Ok(());
+        }
+        self.b.skip("PostScript (path limit)");
+        Err(Flow::Quit)
+    }
+
+    /// [`Self::path_fits`] for the current path with `n` more elements.
+    pub(super) fn room(&mut self, n: usize) -> Result<(), Flow> {
+        self.path_fits(self.gs.path.elements().len().saturating_add(n))
+    }
+
+    pub(super) fn move_to(&mut self, p: Point) -> Result<(), Flow> {
+        // A moveto right after a moveto replaces it (PostScript Language Reference §8.2, `moveto`).
+        if matches!(self.gs.path.elements().last(), Some(PathEl::MoveTo(_))) {
+            self.gs.path.pop();
+        }
+        self.room(1)?;
+        let q = self.gs.ctm * p;
+        self.gs.path.move_to(q);
+        self.gs.cur = Some(q);
+        self.gs.start = Some(q);
+        Ok(())
+    }
+
+    pub(super) fn line_to(&mut self, p: Point) -> Result<(), Flow> {
+        self.room(1 + usize::from(self.gs.cur.is_none()))?;
+        let q = self.gs.ctm * p;
+        if self.gs.cur.is_none() {
+            self.gs.path.move_to(q);
+            self.gs.start = Some(q);
+        }
+        self.gs.path.line_to(q);
+        self.gs.cur = Some(q);
+        Ok(())
+    }
+
+    pub(super) fn curve_to(&mut self, a: Point, b: Point, c: Point) -> Result<(), Flow> {
+        self.room(1 + usize::from(self.gs.cur.is_none()))?;
+        let m = self.gs.ctm;
+        if self.gs.cur.is_none() {
+            self.gs.path.move_to(m * a);
+        }
+        self.gs.path.curve_to(m * a, m * b, m * c);
+        self.gs.cur = Some(m * c);
+        Ok(())
+    }
+
+    pub(super) fn current_user(&self) -> Point {
+        self.gs.ctm.inverse() * self.gs.cur.unwrap_or_default()
+    }
+
+    pub(super) fn arc(&mut self, neg: bool) -> Result<(), Flow> {
+        let a2 = self.popn();
+        let a1 = self.popn();
+        let r = self.popn();
+        let c = self.user_point();
+        // `arc` raises `a2` by multiples of 360 until it is at least `a1`, and `arcn` lowers it
+        // until it is at most `a1` (PostScript Language Reference §8.2, `arc` and `arcn`). Those
+        // sweeps, and the first endpoint, are worked out from what is left of each angle after
+        // whole turns.
+        let sweep = if !neg && a2 < a1 {
+            ccw_turn(a1, a2)
+        } else if neg && a2 > a1 {
+            -ccw_turn(a2, a1)
+        } else {
+            a2 - a1
+        };
+        // A sweep of more than `MAX_ARC_TURNS` turns is shortened by whole pairs of turns to
+        // between `MAX_ARC_TURNS - 2` and `MAX_ARC_TURNS` turns, with a skip note. The arc still
+        // ends at `a2`, and an even-odd fill or clip of it covers the same area as the full sweep.
+        let max = MAX_ARC_TURNS * 360.0;
+        let sweep = if sweep.abs() > max {
+            self.b.skip("arc (too many turns)");
+            let s = sweep.signum();
+            s * (max - 720.0 + (s * (a2 % 720.0 - a1 % 720.0)).rem_euclid(720.0))
+        } else {
+            sweep
+        };
+        let (a1, sweep) = ((a1 % 360.0).to_radians(), sweep.to_radians());
+        let start = Point::new(c.x + r * a1.cos(), c.y + r * a1.sin());
+        if self.gs.cur.is_some() {
+            self.line_to(start)?;
+        } else {
+            self.move_to(start)?;
+        }
+        let arc = kurbo::Arc::new(c, (r, r), a1, sweep, 0.0);
+        let m = self.gs.ctm;
+        // kurbo divides an arc into more curves the larger the radius (about 3.7 × 10^49 for a
+        // quarter turn at a radius of 10^300, more than a usize can count), so each one counts
+        // against the budget and the path limit.
+        let mut curves = arc.append_iter(0.1);
+        while let Some(PathEl::CurveTo(p1, p2, p3)) = curves.next() {
+            self.room(1)?;
+            self.spend(1)?;
+            self.gs.path.curve_to(m * p1, m * p2, m * p3);
+            self.gs.cur = Some(m * p3);
+        }
+        Ok(())
+    }
+
+    pub(super) fn paint(&mut self, fill: Option<FillRule>, stroke: bool) {
+        let path = std::mem::take(&mut self.gs.path);
+        self.gs.cur = None;
+        self.gs.start = None;
+        let s = self.device_scale();
+        let st = stroke.then(|| Stroke {
+            paint: Paint::Color(self.gs.color),
+            opacity: 1.0,
+            width: if self.gs.lw <= 0.0 { 1.0 } else { self.gs.lw * s },
+            cap: self.gs.cap,
+            join: self.gs.join,
+            miter: self.gs.miter.max(1.0),
+            dash: self.gs.dash.as_ref().map(|(a, o)| (a.iter().map(|v| v * s).collect(), o * s)),
+        });
+        self.b.fill_stroke(path, Affine::IDENTITY, fill.map(|r| (Paint::Color(self.gs.color), 1.0, r)), st);
+    }
+
+    pub(super) fn rect_path(&mut self) -> Result<Vec<BezPath>, Flow> {
+        // x y w h, or an array / string of numbers.
+        let top = self.pop();
+        let nums: Vec<f64> = match &top {
+            V::Array(_) | V::Proc(_) => {
+                let items = top.items().unwrap_or_default();
+                // An array's rectangles count against the budget, five path elements each.
+                self.spend(items.len() / 4 * 5)?;
+                items.iter().filter_map(V::num).collect()
+            }
+            V::Num(h) => {
+                let w = self.popn();
+                let y = self.popn();
+                let x = self.popn();
+                vec![x, y, w, *h]
+            }
+            _ => vec![],
+        };
+        self.path_fits(nums.len() / 4 * 5)?;
+        let m = self.gs.ctm;
+        Ok(nums
+            .as_chunks::<4>()
+            .0
+            .iter()
+            .map(|r| {
+                let mut p = BezPath::new();
+                p.move_to(m * Point::new(r[0], r[1]));
+                p.line_to(m * Point::new(r[0] + r[2], r[1]));
+                p.line_to(m * Point::new(r[0] + r[2], r[1] + r[3]));
+                p.line_to(m * Point::new(r[0], r[1] + r[3]));
+                p.close_path();
+                p
+            })
+            .collect())
+    }
+
+    pub(super) fn grestore(&mut self) {
+        if let Some(g) = self.saved.pop() {
+            let d = g.depth;
+            self.gs = g;
+            self.b.close_to(d);
+        }
+    }
+}
diff --git a/crates/pdf/src/ps/scanner.rs b/crates/pdf/src/ps/scanner.rs
new file mode 100644
index 000000000..59933e214
--- /dev/null
+++ b/crates/pdf/src/ps/scanner.rs
@@ -0,0 +1,223 @@
+use super::value::V;
+use super::{Rc, RefCell, ascii85, is_white, parse_num};
+
+/// Source tokenizer (the data source for `currentfile`).
+pub(super) struct Src<'a> {
+    pub(super) d: &'a [u8],
+    pub(crate) pos: usize,
+}
+
+impl Src<'_> {
+    fn skip_ws(&mut self) {
+        while self.pos < self.d.len() {
+            let c = self.d[self.pos];
+            if is_white(c) {
+                self.pos += 1;
+            } else if c == b'%' {
+                let s = self.pos;
+                while self.pos < self.d.len() && !matches!(self.d[self.pos], b'\n' | b'\r') {
+                    self.pos += 1;
+                }
+                // DSC: skip embedded binary / data sections.
+                let line = &self.d[s..self.pos];
+                if line.starts_with(b"%%BeginData:") || line.starts_with(b"%%BeginBinary:") || line.starts_with(b"%%BeginPreview") {
+                    let end: &[u8] = if line.starts_with(b"%%BeginData:") {
+                        b"%%EndData"
+                    } else if line.starts_with(b"%%BeginBinary:") {
+                        b"%%EndBinary"
+                    } else {
+                        b"%%EndPreview"
+                    };
+                    match self.d[self.pos..].windows(end.len()).position(|w| w == end) {
+                        Some(p) => self.pos += p,
+                        None => self.pos = self.d.len(),
+                    }
+                }
+            } else {
+                break;
+            }
+        }
+    }
+
+    fn word(&mut self) -> &[u8] {
+        let s = self.pos;
+        while self.pos < self.d.len() {
+            let c = self.d[self.pos];
+            if is_white(c) || matches!(c, b'(' | b')' | b'<' | b'>' | b'[' | b']' | b'{' | b'}' | b'/' | b'%') {
+                break;
+            }
+            self.pos += 1;
+        }
+        &self.d[s..self.pos]
+    }
+
+    /// The next token; `{ … }` comes back as a whole procedure.
+    pub(super) fn token(&mut self, depth: usize) -> Option<V> {
+        self.skip_ws();
+        let c = *self.d.get(self.pos)?;
+        Some(match c {
+            b'{' => {
+                self.pos += 1;
+                let mut body = vec![];
+                loop {
+                    self.skip_ws();
+                    match self.d.get(self.pos) {
+                        None => break,
+                        Some(b'}') => {
+                            self.pos += 1;
+                            break;
+                        }
+                        _ => {
+                            if depth > 100 {
+                                return None;
+                            }
+                            match self.token(depth + 1) {
+                                Some(t) => body.push(t),
+                                None => break,
+                            }
+                        }
+                    }
+                }
+                V::Proc(Rc::new(body))
+            }
+            b'}' => {
+                self.pos += 1;
+                V::Null
+            }
+            b'/' => {
+                self.pos += 1;
+                let imm = self.d.get(self.pos) == Some(&b'/');
+                if imm {
+                    self.pos += 1;
+                }
+                let w = String::from_utf8_lossy(self.word()).into_owned();
+                // `//name` (immediately evaluated) is treated like a plain name.
+                if imm { V::Name(w.into()) } else { V::Lit(w.into()) }
+            }
+            b'(' => {
+                self.pos += 1;
+                let mut out = vec![];
+                let mut depth = 1;
+                while self.pos < self.d.len() {
+                    let c = self.d[self.pos];
+                    self.pos += 1;
+                    match c {
+                        b'\\' => {
+                            let e = self.d.get(self.pos).copied().unwrap_or(b'\\');
+                            self.pos += 1;
+                            match e {
+                                b'n' => out.push(b'\n'),
+                                b'r' => out.push(b'\r'),
+                                b't' => out.push(b'\t'),
+                                b'0'..=b'7' => {
+                                    let mut v = (e - b'0') as u32;
+                                    for _ in 0..2 {
+                                        match self.d.get(self.pos) {
+                                            Some(d @ b'0'..=b'7') => {
+                                                v = v * 8 + (d - b'0') as u32;
+                                                self.pos += 1;
+                                            }
+                                            _ => break,
+                                        }
+                                    }
+                                    out.push(v as u8);
+                                }
+                                b'\n' | b'\r' => {}
+                                o => out.push(o),
+                            }
+                        }
+                        b'(' => {
+                            depth += 1;
+                            out.push(c);
+                        }
+                        b')' => {
+                            depth -= 1;
+                            if depth == 0 {
+                                break;
+                            }
+                            out.push(c);
+                        }
+                        _ => out.push(c),
+                    }
+                }
+                V::Str(Rc::new(RefCell::new(out)))
+            }
+            b'<' if self.d.get(self.pos + 1) == Some(&b'<') => {
+                self.pos += 2;
+                V::Name("<<".into())
+            }
+            b'>' if self.d.get(self.pos + 1) == Some(&b'>') => {
+                self.pos += 2;
+                V::Name(">>".into())
+            }
+            b'<' if self.d.get(self.pos + 1) == Some(&b'~') => {
+                let s = self.pos;
+                while self.pos + 1 < self.d.len() && !(self.d[self.pos] == b'~' && self.d[self.pos + 1] == b'>') {
+                    self.pos += 1;
+                }
+                self.pos = (self.pos + 2).min(self.d.len());
+                V::Str(Rc::new(RefCell::new(ascii85(&self.d[s..self.pos]))))
+            }
+            b'<' => {
+                self.pos += 1;
+                let mut hex = vec![];
+                while self.pos < self.d.len() && self.d[self.pos] != b'>' {
+                    if self.d[self.pos].is_ascii_hexdigit() {
+                        hex.push(self.d[self.pos]);
+                    }
+                    self.pos += 1;
+                }
+                self.pos += 1;
+                if hex.len() % 2 == 1 {
+                    hex.push(b'0');
+                }
+                let h = |c: u8| (c as char).to_digit(16).unwrap_or(0) as u8;
+                V::Str(Rc::new(RefCell::new(hex.chunks(2).map(|p| (h(p[0]) << 4) | h(p[1])).collect())))
+            }
+            b'[' | b']' => {
+                self.pos += 1;
+                V::Name(if c == b'[' { "[" } else { "]" }.into())
+            }
+            b')' | b'>' => {
+                self.pos += 1;
+                V::Null
+            }
+            _ => {
+                let w = self.word();
+                if w.is_empty() {
+                    self.pos += 1;
+                    return Some(V::Null);
+                }
+                match parse_num(w) {
+                    Some(n) => V::Num(n),
+                    None => {
+                        // Radix numbers (16#FF).
+                        let s = String::from_utf8_lossy(w).into_owned();
+                        match s.split_once('#').and_then(|(r, v)| i64::from_str_radix(v, r.parse::<u32>().ok().filter(|r| (2..=36).contains(r))?).ok()) {
+                            Some(n) => V::Num(n as f64),
+                            None => V::Name(s.into()),
+                        }
+                    }
+                }
+            }
+        })
+    }
+
+    /// Step over inline image data that follows an `image` operator reading `currentfile`.
+    pub(super) fn skip_image_data(&mut self) {
+        self.skip_ws();
+        if self.d[self.pos..].starts_with(b"<~") || self.d.get(self.pos).is_some_and(|c| (b'!'..=b'u').contains(c) && !c.is_ascii_hexdigit()) {
+            match self.d[self.pos..].windows(2).position(|w| w == b"~>") {
+                Some(p) => self.pos += p + 2,
+                None => self.pos = self.d.len(),
+            }
+            return;
+        }
+        while self.pos < self.d.len() && (self.d[self.pos].is_ascii_hexdigit() || is_white(self.d[self.pos])) {
+            self.pos += 1;
+        }
+        if self.d.get(self.pos) == Some(&b'>') {
+            self.pos += 1;
+        }
+    }
+}
diff --git a/crates/pdf/src/ps/text.rs b/crates/pdf/src/ps/text.rs
new file mode 100644
index 000000000..b138965bb
--- /dev/null
+++ b/crates/pdf/src/ps/text.rs
@@ -0,0 +1,322 @@
+use super::scanner::Src;
+use super::value::{DictRef, Flow, V, array, matrix_of, matrix_val, new_dict};
+use super::{Affine, BezPath, FillRule, Font, HashMap, Interp, Paint, Point, Rc, RefCell};
+
+// ------------------------------------------------------------------ text
+
+/// An encoding array of glyph names (`StandardEncoding`; `ISOLatin1Encoding` and others are
+/// approximated by WinAnsi, which agrees with ISO Latin-1 on the printable codes).
+pub(super) fn encoding_array(name: &str) -> V {
+    let base = if name == "StandardEncoding" { crate::encoding::Base::Standard } else { crate::encoding::Base::WinAnsi };
+    array((0..256).map(|c| V::Lit(base.name(c as u8).unwrap_or_else(|| ".notdef".into()).into())).collect())
+}
+
+fn dict_matrix(d: &DictRef, key: &str) -> Affine {
+    d.borrow().get(key).and_then(matrix_of).unwrap_or(Affine::IDENTITY)
+}
+
+/// A copy of a font dictionary with `m` applied after its matrix (`scalefont`, `makefont`).
+fn transformed(font: &DictRef, m: Affine) -> DictRef {
+    let copy: HashMap<String, V> = font.borrow().clone();
+    let d = Rc::new(RefCell::new(copy));
+    let old = dict_matrix(&d, "__m");
+    d.borrow_mut().insert("__m".into(), matrix_val(m * old));
+    d
+}
+
+impl Interp {
+    /// A font dictionary by name: one `definefont` made, else a new dictionary for an
+    /// embedded program or a bundled stand-in.
+    pub(super) fn find_font(&mut self, key: &str) -> DictRef {
+        if let Some(d) = self.font_dir.get(key) {
+            return d.clone();
+        }
+        let d = new_dict();
+        {
+            let mut m = d.borrow_mut();
+            m.insert("FontName".into(), V::Lit(key.into()));
+            m.insert("FontType".into(), V::Num(1.0));
+            m.insert("FontMatrix".into(), matrix_val(Affine::scale(0.001)));
+            m.insert("FID".into(), V::Null);
+            m.insert("__base".into(), V::Lit(key.into()));
+            m.insert("__m".into(), matrix_val(Affine::IDENTITY));
+        }
+        self.font_dir.insert(key.to_string(), d.clone());
+        d
+    }
+
+    /// The drawable font of a font dictionary (its base program and encoding) and the matrix
+    /// from text space (font size 1) to user space.
+    fn font_of(&mut self, d: &DictRef) -> Option<(Rc<Font>, Affine)> {
+        if matches!(d.borrow().get("FontType"), Some(V::Num(t)) if *t == 3.0) {
+            // Type 3 fonts (glyph procedures) are not run.
+            self.b.skip("EPS Type 3 font");
+            return None;
+        }
+        let (base, names) = {
+            let m = d.borrow();
+            let base = m.get("__base").or_else(|| m.get("FontName")).map(V::key)?;
+            let names: Option<Vec<Option<String>>> = m.get("Encoding").and_then(V::items).map(|a| {
+                a.iter()
+                    .map(|v| match v {
+                        V::Lit(n) | V::Name(n) if &**n != ".notdef" => Some(n.to_string()),
+                        _ => None,
+                    })
+                    .collect()
+            });
+            (base, names)
+        };
+        let key = match &names {
+            Some(n) => format!("{base}\u{0}{}", n.iter().map(|x| x.as_deref().unwrap_or("")).collect::<Vec<_>>().join(" ")),
+            None => base.clone(),
+        };
+        let font = match self.font_cache.get(&key) {
+            Some(f) => f.clone(),
+            None => {
+                // Not embedded: a bundled stand-in, as for PDF.
+                let prog = self.embedded.get(&base).cloned();
+                let f = Rc::new(Font::standalone(&base, prog.as_ref().map(|(d, cff)| (d.as_slice(), *cff)), names));
+                self.font_cache.insert(key, f.clone());
+                f
+            }
+        };
+        Some((font, dict_matrix(d, "__m")))
+    }
+
+    /// A string's glyph outlines (device space) from the current point, with an extra
+    /// displacement `extra(index, code)` (user space) after each glyph; moves the current
+    /// point.
+    fn text_path(&mut self, bytes: &[u8], mut extra: impl FnMut(usize, u32) -> (f64, f64)) -> Result<Option<(BezPath, String)>, Flow> {
+        let Some(d) = self.gs.font.clone() else { return Ok(None) };
+        let Some((font, m)) = self.font_of(&d) else { return Ok(None) };
+        let mut p = self.current_user();
+        let mut path = BezPath::new();
+        let mut text = String::new();
+        let ctm = self.gs.ctm;
+        for (i, &code) in bytes.iter().enumerate() {
+            let code = code as u32;
+            if let Some(g) = font.glyph(code) {
+                path.extend(ctm * Affine::translate(p.to_vec2()) * m * (*g).clone());
+            }
+            text.push_str(&font.unicode(code));
+            let adv = m * Point::new(font.width(code), 0.0) - m * Point::ZERO;
+            let (ex, ey) = extra(i, code);
+            p += adv + kurbo::Vec2::new(ex, ey);
+        }
+        self.move_to(p)?;
+        Ok(Some((path, text)))
+    }
+
+    fn fill_text(&mut self, path: BezPath, text: &str) {
+        let label: String = text.chars().filter(|c| !c.is_control()).take(40).collect();
+        let name = if label.trim().is_empty() { "Text".to_string() } else { format!("Text: {}", label.trim()) };
+        self.b.fill_stroke_named(&name, path, Affine::IDENTITY, Some((Paint::Color(self.gs.color), 1.0, FillRule::NonZero)), None);
+    }
+
+    fn pop_string(&mut self) -> Vec<u8> {
+        match self.pop() {
+            V::Str(s) => s.borrow().clone(),
+            _ => vec![],
+        }
+    }
+
+    fn show_with(&mut self, s: &[u8], extra: impl FnMut(usize, u32) -> (f64, f64)) -> Result<(), Flow> {
+        match self.text_path(s, extra)? {
+            Some((path, text)) => self.fill_text(path, &text),
+            None => self.b.skip("text (no font)"),
+        }
+        Ok(())
+    }
+
+    /// Text and font operators (PostScript Language Reference §5.1, §8.2).
+    pub(super) fn text_op(&mut self, n: &str, src: &mut Src) -> Result<(), Flow> {
+        match n {
+            "scalefont" | "makefont" => {
+                let m = if n == "scalefont" {
+                    Affine::scale(self.popn())
+                } else {
+                    let v = self.pop();
+                    matrix_of(&v).unwrap_or(Affine::IDENTITY)
+                };
+                let font = match self.pop() {
+                    V::Dict(d) => d,
+                    _ => self.find_font("Helvetica"),
+                };
+                self.push(V::Dict(transformed(&font, m)));
+            }
+            "selectfont" => {
+                let size = self.pop();
+                let key = self.pop().key();
+                let font = self.find_font(&key);
+                let m = match &size {
+                    V::Num(s) => Affine::scale(*s),
+                    other => matrix_of(other).unwrap_or(Affine::IDENTITY),
+                };
+                self.gs.font = Some(transformed(&font, m));
+            }
+            "setfont" => {
+                if let V::Dict(d) = self.pop() {
+                    self.gs.font = Some(d);
+                }
+            }
+            "currentfont" | "rootfont" => {
+                let d = self.gs.font.clone().unwrap_or_else(new_dict);
+                self.push(V::Dict(d));
+            }
+            "definefont" => {
+                let v = self.pop();
+                let key = self.pop().key();
+                if let V::Dict(d) = &v {
+                    if !d.borrow().contains_key("__base") {
+                        // A font the file defines itself: its embedded program, by name.
+                        d.borrow_mut().insert("__base".into(), V::Lit(key.as_str().into()));
+                        d.borrow_mut().insert("__m".into(), matrix_val(Affine::IDENTITY));
+                    }
+                    self.font_dir.insert(key, d.clone());
+                }
+                self.push(v);
+            }
+            "undefinefont" => {
+                let key = self.pop().key();
+                self.font_dir.remove(&key);
+            }
+            "StandardEncoding" | "ISOLatin1Encoding" => self.push(encoding_array(n)),
+            "show" => {
+                let s = self.pop_string();
+                self.show_with(&s, |_, _| (0.0, 0.0))?;
+            }
+            "ashow" => {
+                let s = self.pop_string();
+                let ay = self.popn();
+                let ax = self.popn();
+                self.show_with(&s, |_, _| (ax, ay))?;
+            }
+            "widthshow" => {
+                let s = self.pop_string();
+                let ch = self.popn() as u32;
+                let cy = self.popn();
+                let cx = self.popn();
+                self.show_with(&s, |_, c| if c == ch { (cx, cy) } else { (0.0, 0.0) })?;
+            }
+            "awidthshow" => {
+                let s = self.pop_string();
+                let ay = self.popn();
+                let ax = self.popn();
+                let ch = self.popn() as u32;
+                let cy = self.popn();
+                let cx = self.popn();
+                self.show_with(&s, |_, c| if c == ch { (cx + ax, cy + ay) } else { (ax, ay) })?;
+            }
+            "kshow" | "cshow" => {
+                // The procedure between characters is not run.
+                let s = self.pop_string();
+                self.pop();
+                self.show_with(&s, |_, _| (0.0, 0.0))?;
+            }
+            "xshow" | "yshow" | "xyshow" => {
+                let disp: Vec<f64> = self.pop().items().unwrap_or_default().iter().filter_map(V::num).collect();
+                let s = self.pop_string();
+                self.explicit_show(&s, &disp, n)?;
+            }
+            "glyphshow" => {
+                let name = self.pop().key();
+                let Some(d) = self.gs.font.clone() else { return Ok(()) };
+                // Drawn through a one-glyph encoding.
+                let mut e: Vec<V> = (0..256).map(|_| V::Lit(".notdef".into())).collect();
+                e[65] = V::Lit(name.as_str().into());
+                let tmp = transformed(&d, Affine::IDENTITY);
+                tmp.borrow_mut().insert("Encoding".into(), array(e));
+                self.gs.font = Some(tmp);
+                self.show_with(b"A", |_, _| (0.0, 0.0))?;
+                self.gs.font = Some(d);
+            }
+            "charpath" => {
+                self.pop();
+                let s = self.pop_string();
+                let saved = std::mem::take(&mut self.gs.path);
+                let start = self.gs.start;
+                match self.text_path(&s, |_, _| (0.0, 0.0))? {
+                    Some((glyphs, _)) => {
+                        // The outlines join the path: each element counts against the budget and
+                        // the path limit.
+                        self.gs.path = saved;
+                        self.room(glyphs.elements().len() + 1)?;
+                        self.spend(glyphs.elements().len())?;
+                        self.gs.path.extend(glyphs);
+                        if let Some(c) = self.gs.cur {
+                            self.gs.path.move_to(c);
+                        }
+                        self.gs.start = start;
+                    }
+                    None => self.gs.path = saved,
+                }
+            }
+            "stringwidth" => {
+                let s = self.pop_string();
+                let (mut w, mut h) = (0.0, 0.0);
+                if let Some(d) = self.gs.font.clone()
+                    && let Some((font, m)) = self.font_of(&d)
+                {
+                    for &c in &s {
+                        let v = m * Point::new(font.width(c as u32), 0.0) - m * Point::ZERO;
+                        w += v.x;
+                        h += v.y;
+                    }
+                }
+                self.push(V::Num(w));
+                self.push(V::Num(h));
+            }
+            "setcachedevice" => {
+                for _ in 0..6 {
+                    self.pop();
+                }
+            }
+            "setcharwidth" => {
+                self.pop();
+                self.pop();
+            }
+            // An embedded Type 1 program's encrypted part (read by `embedded_fonts`).
+            "eexec" => {
+                if matches!(self.pop(), V::File) {
+                    let rest = &src.d[src.pos.min(src.d.len())..];
+                    src.pos += rest.windows(11).position(|w| w == b"cleartomark").map_or(rest.len(), |p| p + 11);
+                }
+            }
+            // A CFF font set's binary data (read by `embedded_fonts`).
+            "StartData" => {
+                let len = self.popn().max(0.0) as usize;
+                self.pop();
+                src.pos = src.pos.saturating_add(1).saturating_add(len).min(src.d.len());
+            }
+            _ => {}
+        }
+        Ok(())
+    }
+
+    /// `xshow` / `yshow` / `xyshow`: glyph displacements from a number array instead of the
+    /// advances.
+    fn explicit_show(&mut self, s: &[u8], disp: &[f64], n: &str) -> Result<(), Flow> {
+        let step = if n == "xyshow" { 2 } else { 1 };
+        let d: Vec<(f64, f64)> = (0..s.len())
+            .map(|k| {
+                let i = k * step;
+                let v = |j: usize| disp.get(j).copied().unwrap_or(0.0);
+                match n {
+                    "xshow" => (v(i), 0.0),
+                    "yshow" => (0.0, v(i)),
+                    _ => (v(i), v(i + 1)),
+                }
+            })
+            .collect();
+        let Some(fd) = self.gs.font.clone() else {
+            self.b.skip("text (no font)");
+            return Ok(());
+        };
+        let Some((font, m)) = self.font_of(&fd) else { return Ok(()) };
+        self.show_with(s, move |k, c| {
+            let adv = m * Point::new(font.width(c), 0.0) - m * Point::ZERO;
+            let (dx, dy) = d.get(k).copied().unwrap_or((0.0, 0.0));
+            (dx - adv.x, dy - adv.y)
+        })
+    }
+}
diff --git a/crates/pdf/src/ps/value.rs b/crates/pdf/src/ps/value.rs
new file mode 100644
index 000000000..3cfafed6e
--- /dev/null
+++ b/crates/pdf/src/ps/value.rs
@@ -0,0 +1,88 @@
+use super::{Affine, BezPath, Cap, HashMap, Join, Point, Rc, RefCell};
+
+pub(crate) type DictRef = Rc<RefCell<HashMap<String, V>>>;
+
+#[derive(Clone)]
+pub(crate) enum V {
+    Num(f64),
+    Bool(bool),
+    /// An executable name.
+    Name(Rc<str>),
+    /// A literal name (`/name`).
+    Lit(Rc<str>),
+    /// A built-in operator, as `load` returns it for a name no dictionary defines.
+    Op(Rc<str>),
+    Str(Rc<RefCell<Vec<u8>>>),
+    Proc(Rc<Vec<V>>),
+    Array(Rc<RefCell<Vec<V>>>),
+    Dict(DictRef),
+    Mark,
+    Null,
+    /// `currentfile`.
+    File,
+}
+
+impl V {
+    pub(super) fn num(&self) -> Option<f64> {
+        match self {
+            V::Num(n) => Some(*n),
+            _ => None,
+        }
+    }
+    pub(super) fn key(&self) -> String {
+        match self {
+            V::Name(n) | V::Lit(n) | V::Op(n) => n.to_string(),
+            V::Str(s) => String::from_utf8_lossy(&s.borrow()).into_owned(),
+            V::Num(n) => format!("{n}"),
+            V::Bool(b) => format!("{b}"),
+            _ => String::new(),
+        }
+    }
+    pub(super) fn items(&self) -> Option<Vec<V>> {
+        match self {
+            V::Array(a) => Some(a.borrow().clone()),
+            V::Proc(p) => Some(p.as_ref().clone()),
+            _ => None,
+        }
+    }
+}
+
+pub(super) enum Flow {
+    Exit,
+    Stop,
+    Quit,
+}
+
+#[derive(Clone)]
+pub(super) struct GState {
+    pub(crate) ctm: Affine,
+    pub(crate) color: [f64; 3],
+    pub(crate) lw: f64,
+    pub(crate) cap: Cap,
+    pub(crate) join: Join,
+    pub(crate) miter: f64,
+    pub(crate) dash: Option<(Vec<f64>, f64)>,
+    pub(crate) path: BezPath,
+    pub(crate) cur: Option<Point>,
+    pub(crate) start: Option<Point>,
+    pub(crate) depth: usize,
+    /// The current font dictionary.
+    pub(crate) font: Option<DictRef>,
+}
+
+pub(super) fn new_dict() -> DictRef {
+    Rc::new(RefCell::new(HashMap::new()))
+}
+
+pub(super) fn array(v: Vec<V>) -> V {
+    V::Array(Rc::new(RefCell::new(v)))
+}
+
+pub(super) fn matrix_of(v: &V) -> Option<Affine> {
+    let a: Vec<f64> = v.items()?.iter().filter_map(V::num).collect();
+    (a.len() == 6).then(|| Affine::new([a[0], a[1], a[2], a[3], a[4], a[5]]))
+}
+
+pub(super) fn matrix_val(m: Affine) -> V {
+    array(m.as_coeffs().iter().map(|c| V::Num(*c)).collect())
+}
diff --git a/crates/pdf/src/tests.rs b/crates/pdf/src/tests.rs
index 40f064af7..2d09a7406 100644
--- a/crates/pdf/src/tests.rs
+++ b/crates/pdf/src/tests.rs
@@ -4,6 +4,11 @@ use super::*;
 
 use crate::write::pdf;
 
+mod groups;
+mod import;
+mod reader;
+mod shading;
+
 const CONTENT: &str = "/OC /MC0 BDC\n0 1 0 rg 0 0 200 100 re f\nEMC\n\
 /OC /MC1 BDC\nq 10 10 80 80 re W n\n1 0 0 rg 0 0 50 100 re f\nQ\n\
 /Pattern cs /P0 scn 100 0 100 50 re f\n\
diff --git a/crates/pdf/src/tests_groups.rs b/crates/pdf/src/tests/groups.rs
similarity index 99%
rename from crates/pdf/src/tests_groups.rs
rename to crates/pdf/src/tests/groups.rs
index ce928139f..14b6a4b09 100644
--- a/crates/pdf/src/tests_groups.rs
+++ b/crates/pdf/src/tests/groups.rs
@@ -1,8 +1,8 @@
 //! M13.12: transparency groups (isolated, knockout, group alpha) and soft masks on a group's
 //! combined result.
 
-use super::*;
 use crate::tests::{page_pdf, render};
+use crate::*;
 
 fn near(a: [f32; 4], b: [f32; 4]) -> bool {
     (0..4).all(|i| (a[i] - b[i]).abs() < 0.02)
diff --git a/crates/pdf/src/tests_import.rs b/crates/pdf/src/tests/import.rs
similarity index 99%
rename from crates/pdf/src/tests_import.rs
rename to crates/pdf/src/tests/import.rs
index 11ef72f8f..c7dcbee57 100644
--- a/crates/pdf/src/tests_import.rs
+++ b/crates/pdf/src/tests/import.rs
@@ -1,8 +1,8 @@
 //! M13.12: CCITT images in PDF pages, EPS text and parser robustness over truncated and
 //! corrupt inputs (generated fixtures).
 
-use super::*;
 use crate::tests::{coverage, page_pdf, render, shape_names};
+use crate::*;
 
 fn eps(body: &[u8]) -> Doc {
     let mut b = b"%!PS-Adobe-3.0 EPSF-3.0\n%%BoundingBox: 0 0 200 100\n".to_vec();
diff --git a/crates/pdf/src/tests_reader.rs b/crates/pdf/src/tests/reader.rs
similarity index 100%
rename from crates/pdf/src/tests_reader.rs
rename to crates/pdf/src/tests/reader.rs
diff --git a/crates/pdf/src/tests_shading.rs b/crates/pdf/src/tests/shading.rs
similarity index 99%
rename from crates/pdf/src/tests_shading.rs
rename to crates/pdf/src/tests/shading.rs
index 12ca2ff86..8e96193ab 100644
--- a/crates/pdf/src/tests_shading.rs
+++ b/crates/pdf/src/tests/shading.rs
@@ -1,7 +1,7 @@
 //! M13.12: function-based and mesh shadings (generated fixtures).
 
-use super::*;
 use crate::tests::{Objs, page_pdf, render};
+use crate::*;
 
 /// Mesh vertex data: 8-bit flags, 16-bit coordinates (Decode `[0 65535 0 65535 …]`, so raw
 /// values are page units) and 8-bit components.
diff --git a/crates/project/src/build.rs b/crates/project/src/build.rs
index 935c03b0e..b78e3d8c1 100644
--- a/crates/project/src/build.rs
+++ b/crates/project/src/build.rs
@@ -4,7 +4,7 @@ use effectcraft_color::{BlendMode, Label};
 use effectcraft_keyframe::{Gradient, ShapePath, TextDoc, Value};
 use effectcraft_time::Tick;
 
-use crate::props::{GroupKind, MaskMode, ParamUi, PropGroup, Property};
+use crate::props::{GroupKind, MaskMode, Node, ParamUi, PropGroup, Property};
 use crate::{Comp, Layer, LayerId, LayerSource, LightKind, Project, Switches};
 
 /// Id allocator borrowing the project's counter.
@@ -594,6 +594,7 @@ pub fn shape_simple_op(ids: &mut Ids, kind: &str) -> Option<PropGroup> {
             .with(ids.prop("speed", "Wiggles/Second", Value::Scalar(2.0)))
             .with(ids.prop("correlation", "Correlation", Value::Scalar(50.0)).with_ui(ParamUi::Percent))
             .with(ids.prop("phase", "Temporal Phase", Value::Scalar(0.0)).with_ui(ParamUi::Angle))
+            .with(wiggle_spatial_phase(ids))
             .with(ids.prop("seed", "Random Seed", Value::Scalar(0.0))),
         "merge" => indexed(ids.group("merge", "Merge Paths 1")).with(ids.prop("mode", "Mode", Value::Enum(0)).with_ui(popup(&[
             "Merge",
@@ -607,6 +608,32 @@ pub fn shape_simple_op(ids: &mut Ids, kind: &str) -> Option<PropGroup> {
     Some(g)
 }
 
+/// Wiggle Paths' Spatial Phase.
+fn wiggle_spatial_phase(ids: &mut Ids) -> Property {
+    ids.prop("spatialPhase", "Spatial Phase", Value::Scalar(0.0)).with_ui(ParamUi::Angle)
+}
+
+/// Adds the properties that shape path operations have gained since a project was saved (Wiggle
+/// Paths' Spatial Phase), at their defaults, to the operations in `contents` and its nested
+/// groups. Returns whether anything was added. It walks the nested groups with a work list and
+/// does not recurse.
+pub fn upgrade_shape_contents(ids: &mut Ids, contents: &mut PropGroup) -> bool {
+    let mut changed = false;
+    let mut todo = vec![contents];
+    while let Some(group) = todo.pop() {
+        for n in &mut group.children {
+            let Node::Group(g) = n else { continue };
+            if g.match_id == "wiggle" && !g.children.iter().any(|c| c.match_id() == "spatialPhase") {
+                let at = g.children.iter().position(|c| c.match_id() == "phase").map_or(g.children.len(), |i| i + 1);
+                g.children.insert(at, wiggle_spatial_phase(ids).into());
+                changed = true;
+            }
+            todo.push(g);
+        }
+    }
+    changed
+}
+
 // ---------------------------------------------------------------- camera / light / 3D
 
 pub fn camera_options(ids: &mut Ids, zoom: f64) -> PropGroup {
diff --git a/crates/project/src/comp.rs b/crates/project/src/comp.rs
new file mode 100644
index 000000000..5a3c8650e
--- /dev/null
+++ b/crates/project/src/comp.rs
@@ -0,0 +1,427 @@
+use super::item::LayerId;
+use super::layer::{Layer, LayerSource};
+use super::settings::{Marker, yes};
+use super::{Deserialize, FrameRate, Node, PropGroup, Serialize, Tick, Value, essential, styles};
+
+/// 3D renderer of a composition.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Renderer {
+    #[default]
+    Classic3D,
+    Advanced3D,
+}
+
+/// A composition's Resolution (the Composition panel's Resolution/Down Sample Factor popup, View ▸
+/// Resolution): how many of its pixels the viewer renders. Auto follows the magnification.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Resolution {
+    #[default]
+    Auto,
+    Full,
+    Half,
+    Third,
+    Quarter,
+    /// View ▸ Resolution ▸ Custom: render every n-th pixel (2..=40).
+    Custom(u8),
+}
+
+impl Resolution {
+    pub const ALL: [Resolution; 5] = [Resolution::Auto, Resolution::Full, Resolution::Half, Resolution::Third, Resolution::Quarter];
+    pub fn label(self) -> &'static str {
+        match self {
+            Resolution::Auto => "Auto",
+            Resolution::Full => "Full",
+            Resolution::Half => "Half",
+            Resolution::Third => "Third",
+            Resolution::Quarter => "Quarter",
+            Resolution::Custom(_) => "Custom",
+        }
+    }
+    pub fn is_auto(&self) -> bool {
+        *self == Resolution::Auto
+    }
+    /// The down-sample factor (render every n-th pixel); `None` for Auto.
+    pub fn factor(self) -> Option<u8> {
+        match self {
+            Resolution::Auto => None,
+            Resolution::Full => Some(1),
+            Resolution::Half => Some(2),
+            Resolution::Third => Some(3),
+            Resolution::Quarter => Some(4),
+            Resolution::Custom(n) => Some(n),
+        }
+    }
+    /// The resolution that renders every `n`-th pixel (1 = Full … 4 = Quarter; up to 40).
+    pub fn from_factor(n: u64) -> Resolution {
+        match n.clamp(1, 40) {
+            1 => Resolution::Full,
+            2 => Resolution::Half,
+            3 => Resolution::Third,
+            4 => Resolution::Quarter,
+            n => Resolution::Custom(n as u8),
+        }
+    }
+    /// Render scale for a viewer magnification (and display pixel density).
+    pub fn scale(self, zoom: f32, ppp: f32) -> f64 {
+        match self.factor() {
+            Some(n) => 1.0 / f64::from(n.clamp(1, 40)),
+            // As in After Effects, Auto renders the pixels the magnification needs: the coarsest
+            // whole factor that still gives every screen pixel a rendered one (Full above 50 %,
+            // Half down to 33.3 %, Third down to 25 %, Quarter below), never fewer (#417).
+            None => {
+                let n = (1.0 / (zoom * ppp) as f64 + 1e-3).floor();
+                if n >= 1.0 { 1.0 / n.min(4.0) } else { 1.0 }
+            }
+        }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Comp {
+    pub width: u32,
+    pub height: u32,
+    pub pixel_aspect: f64,
+    pub frame_rate: FrameRate,
+    pub duration: Tick,
+    /// Start timecode/frame shown for time 0.
+    pub display_start: Tick,
+    pub background: [f32; 3],
+    pub work_area: (Tick, Tick),
+    /// Layer #1 first (top of the stack).
+    pub layers: Vec<Layer>,
+    #[serde(default)]
+    pub markers: Vec<Marker>,
+    pub shutter_angle: f64,
+    pub shutter_phase: f64,
+    /// Samples Per Frame: the minimum motion-blur samples (and the count for 3D layers).
+    pub motion_blur_samples: u32,
+    /// Adaptive Sample Limit (Composition Settings ▸ Advanced): the most samples a 2D layer gets
+    /// when it moves far within the shutter.
+    #[serde(default = "adaptive_limit_default")]
+    pub motion_blur_adaptive_limit: u32,
+    #[serde(default)]
+    pub renderer: Renderer,
+    /// Comp switches (timeline toolbar).
+    #[serde(default)]
+    pub hide_shy: bool,
+    #[serde(default = "yes")]
+    pub enable_motion_blur: bool,
+    #[serde(default = "yes")]
+    pub enable_frame_blending: bool,
+    #[serde(default)]
+    pub draft_3d: bool,
+    /// Composition Settings ▸ Advanced ▸ Preserve frame rate when nested or in render queue:
+    /// nested in another comp, or rendered at another rate, it shows only its own frames.
+    #[serde(default)]
+    pub preserve_frame_rate: bool,
+    /// Composition Settings ▸ Advanced ▸ Preserve resolution when nested: nested in a comp
+    /// previewed at a lower resolution, it still renders at full size.
+    #[serde(default)]
+    pub preserve_resolution: bool,
+    #[serde(default)]
+    pub poster_time: Tick,
+    /// Global Light for layer styles (Layer ▸ Layer Styles ▸ Blending Options).
+    #[serde(default)]
+    pub global_light: styles::GlobalLight,
+    /// Viewer guides (View ▸ Add Guide…), in comp pixels.
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub guides: Vec<Guide>,
+    /// Essential Graphics: the controls this comp exposes to instances and templates.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub essential: Option<essential::EssentialGraphics>,
+    /// The Composition panel's Resolution, saved with the project as in After Effects. It changes
+    /// what the viewer renders, not the comp's pixels ([`Comp::same_pixels`]), and stays out of
+    /// the undo history.
+    #[serde(default, skip_serializing_if = "Resolution::is_auto")]
+    pub resolution: Resolution,
+}
+
+/// A viewer guide line: vertical guides sit at an x position, horizontal ones at a y position.
+#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Guide {
+    pub vertical: bool,
+    /// Comp pixels, or percent of the comp's width (vertical) / height (horizontal) when
+    /// [`Guide::percent`] is set.
+    pub position: f64,
+    /// A percentage guide (After Effects 26.5): `position` is a percent of the comp's size, so the
+    /// guide keeps its relative place when the comp is resized. Absent in older projects.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub percent: bool,
+}
+
+impl Guide {
+    /// The comp's extent along this guide's axis, never zero.
+    fn extent(&self, width: u32, height: u32) -> f64 {
+        f64::from(if self.vertical { width } else { height }).max(1.0)
+    }
+
+    /// The guide's position in comp pixels for a comp of this size.
+    pub fn px(&self, width: u32, height: u32) -> f64 {
+        if self.percent { self.position / 100.0 * self.extent(width, height) } else { self.position }
+    }
+
+    /// Place the guide at `px` comp pixels, keeping its unit.
+    pub fn set_px(&mut self, px: f64, width: u32, height: u32) {
+        self.position = if self.percent { px / self.extent(width, height) * 100.0 } else { px };
+    }
+
+    /// Switch between pixels and percent without moving the guide on the comp.
+    pub fn set_percent(&mut self, percent: bool, width: u32, height: u32) {
+        let px = self.px(width, height);
+        self.percent = percent;
+        self.set_px(px, width, height);
+    }
+}
+
+fn adaptive_limit_default() -> u32 {
+    128
+}
+
+impl Comp {
+    pub fn new(width: u32, height: u32, frame_rate: FrameRate, duration: Tick) -> Comp {
+        Comp {
+            width,
+            height,
+            pixel_aspect: 1.0,
+            frame_rate,
+            duration,
+            display_start: Tick::ZERO,
+            background: [0.0, 0.0, 0.0],
+            work_area: (Tick::ZERO, duration),
+            layers: vec![],
+            markers: vec![],
+            shutter_angle: 180.0,
+            shutter_phase: -90.0,
+            motion_blur_samples: 16,
+            motion_blur_adaptive_limit: 128,
+            renderer: Renderer::Classic3D,
+            hide_shy: false,
+            enable_motion_blur: true,
+            enable_frame_blending: true,
+            draft_3d: false,
+            preserve_frame_rate: false,
+            preserve_resolution: false,
+            poster_time: Tick::ZERO,
+            guides: vec![],
+            global_light: styles::GlobalLight::default(),
+            essential: None,
+            resolution: Resolution::Auto,
+        }
+    }
+
+    /// Whether the composition has a frame at its time `t`: nested, it shows nothing before it
+    /// starts or after it ends (a precomp layer trimmed or remapped past it).
+    pub fn covers(&self, t: Tick) -> bool {
+        t >= Tick::ZERO && t < self.duration
+    }
+
+    /// A new, empty composition with this one's settings (frame rate, pixel aspect, background,
+    /// motion blur, frame blending and the 3D renderer), as Pre-compose makes.
+    pub fn nested_like(&self, width: u32, height: u32, duration: Tick) -> Comp {
+        Comp {
+            pixel_aspect: self.pixel_aspect,
+            background: self.background,
+            shutter_angle: self.shutter_angle,
+            shutter_phase: self.shutter_phase,
+            motion_blur_samples: self.motion_blur_samples,
+            motion_blur_adaptive_limit: self.motion_blur_adaptive_limit,
+            renderer: self.renderer,
+            enable_motion_blur: self.enable_motion_blur,
+            enable_frame_blending: self.enable_frame_blending,
+            preserve_frame_rate: self.preserve_frame_rate,
+            preserve_resolution: self.preserve_resolution,
+            ..Comp::new(width, height, self.frame_rate, duration)
+        }
+    }
+
+    pub fn layer(&self, id: LayerId) -> Option<&Layer> {
+        self.layers.iter().find(|l| l.id == id)
+    }
+
+    pub fn layer_mut(&mut self, id: LayerId) -> Option<&mut Layer> {
+        self.layers.iter_mut().find(|l| l.id == id)
+    }
+
+    /// 1-based layer number (#) of a layer.
+    pub fn index_of(&self, id: LayerId) -> Option<usize> {
+        self.layers.iter().position(|l| l.id == id).map(|i| i + 1)
+    }
+
+    pub fn layer_by_name(&self, name: &str) -> Option<&Layer> {
+        self.layers.iter().find(|l| l.name == name)
+    }
+
+    pub fn frame_duration(&self) -> Tick {
+        self.frame_rate.frame_duration()
+    }
+
+    /// Any 3D layer present (camera/lights or a 3D switch).
+    pub fn has_3d(&self) -> bool {
+        self.layers.iter().any(|l| l.switches.three_d || matches!(l.source, LayerSource::Camera | LayerSource::Light { .. }))
+    }
+
+    /// The active camera at `t`: the topmost enabled camera layer active at that time.
+    pub fn active_camera(&self, t: Tick) -> Option<&Layer> {
+        self.layers.iter().find(|l| matches!(l.source, LayerSource::Camera) && l.switches.video && l.is_active_at(t))
+    }
+
+    /// Unique layer name with a numeric suffix (`Shape Layer 2`).
+    pub fn unique_layer_name(&self, base: &str) -> String {
+        if !self.layers.iter().any(|l| l.name == base) {
+            return base.to_string();
+        }
+        let stem = base.trim_end_matches(|c: char| c.is_ascii_digit()).trim_end();
+        (2..).map(|i| format!("{stem} {i}")).find(|n| !self.layers.iter().any(|l| &l.name == n)).unwrap_or_default()
+    }
+}
+
+impl Comp {
+    /// Draws the same pixels as `o`: equal but for its layers' Audio, Lock and Shy switches, Hide
+    /// Shy Layers and the viewer's Resolution.
+    pub fn same_pixels(&self, o: &Comp) -> bool {
+        self.same_settings(o) && self.layers.len() == o.layers.len() && self.layers.iter().zip(&o.layers).all(|(a, b)| a.same_pixels(b))
+    }
+
+    /// [`Self::same_pixels`] but for the layers.
+    fn same_settings(&self, o: &Comp) -> bool {
+        // Every field (no `..`: a new field must be considered here).
+        let Comp {
+            width,
+            height,
+            pixel_aspect,
+            frame_rate,
+            duration,
+            display_start,
+            background,
+            work_area,
+            layers: _,
+            markers,
+            shutter_angle,
+            shutter_phase,
+            motion_blur_samples,
+            motion_blur_adaptive_limit,
+            renderer,
+            hide_shy: _,
+            enable_motion_blur,
+            enable_frame_blending,
+            draft_3d,
+            preserve_frame_rate,
+            preserve_resolution,
+            poster_time,
+            global_light,
+            guides,
+            essential,
+            resolution: _,
+        } = self;
+        *width == o.width
+            && *height == o.height
+            && *pixel_aspect == o.pixel_aspect
+            && *frame_rate == o.frame_rate
+            && *duration == o.duration
+            && *display_start == o.display_start
+            && *background == o.background
+            && *work_area == o.work_area
+            && *markers == o.markers
+            && *shutter_angle == o.shutter_angle
+            && *shutter_phase == o.shutter_phase
+            && *motion_blur_samples == o.motion_blur_samples
+            && *motion_blur_adaptive_limit == o.motion_blur_adaptive_limit
+            && *renderer == o.renderer
+            && *enable_motion_blur == o.enable_motion_blur
+            && *enable_frame_blending == o.enable_frame_blending
+            && *draft_3d == o.draft_3d
+            && *preserve_frame_rate == o.preserve_frame_rate
+            && *preserve_resolution == o.preserve_resolution
+            && *poster_time == o.poster_time
+            && *global_light == o.global_light
+            && *guides == o.guides
+            && *essential == o.essential
+    }
+
+    /// The comp-time span (`in_point..out_point` of every layer changed, added or removed,
+    /// widened by the shutter) outside which `self` draws the same pixels as `o`, so cached
+    /// frames there stay valid (#1641). `None` when the edit can reach any frame: a comp setting,
+    /// a layer reorder, Solo turning on or off, an expression (it reads anything), or a changed
+    /// layer another layer parents to, mattes with or picks in an effect.
+    pub fn changed_span(&self, o: &Comp) -> Option<(Tick, Tick)> {
+        fn reads(g: &PropGroup, changed: &[LayerId]) -> bool {
+            g.children.iter().any(|c| match c {
+                Node::Prop(p) => {
+                    p.expr.is_some()
+                        || std::iter::once(&p.value)
+                            .chain(p.keys.iter().map(|k| &k.value))
+                            .any(|v| matches!(v, Value::Layer(Some(id)) if changed.contains(&LayerId(*id))))
+                }
+                Node::Group(g) => reads(g, changed),
+            })
+        }
+        // Solo hides every other layer at every frame.
+        if !self.same_settings(o) || self.any_solo() != o.any_solo() {
+            return None;
+        }
+        let common = |a: &Comp, b: &Comp| a.layers.iter().map(|l| l.id).filter(|id| b.layer(*id).is_some()).collect::<Vec<_>>();
+        if common(self, o) != common(o, self) {
+            return None;
+        }
+        let mut changed = Vec::new();
+        let mut span: Option<(Tick, Tick)> = None;
+        // Each changed layer comes up from both sides: its old and its new span.
+        for (l, other) in self.layers.iter().map(|l| (l, o.layer(l.id))).chain(o.layers.iter().map(|l| (l, self.layer(l.id)))) {
+            if other.is_some_and(|b| l.same_pixels(b)) {
+                continue;
+            }
+            changed.push(l.id);
+            let (s, e) = (l.in_point.min(l.out_point), l.in_point.max(l.out_point));
+            span = Some(span.map_or((s, e), |(a, b)| (a.min(s), b.max(e))));
+        }
+        let reaches = |l: &Layer| {
+            l.parent.is_some_and(|p| changed.contains(&p)) || l.track_matte.as_ref().is_some_and(|m| changed.contains(&m.layer)) || reads(&l.props, &changed)
+        };
+        if self.layers.iter().chain(&o.layers).any(reaches) {
+            return None;
+        }
+        // A frame at `t` samples cameras, lights and transforms over its shutter,
+        // `t + (phase + angle * 0..=1) / 360` frames, and draws the layers active at `t` itself.
+        let (a, p) = (self.shutter_angle / 360.0, self.shutter_phase / 360.0);
+        let fd = self.frame_duration().seconds();
+        let (before, after) = (Tick::from_seconds_f64(p.max(p + a).max(0.0) * fd), Tick::from_seconds_f64(-p.min(p + a).min(0.0) * fd));
+        span.map(|(s, e)| (s - before, e + after))
+    }
+
+    /// Some layer is soloed: only the soloed layers draw.
+    pub fn any_solo(&self) -> bool {
+        self.layers.iter().any(|l| l.switches.solo && l.source.is_av())
+    }
+
+    /// Draws the same pixels as `o` once plain markers are ignored: they change no pixels. Protected
+    /// time markers with a duration set the timing (Responsive Design), so those still count.
+    pub fn same_pixels_ignoring_markers(&self, o: &Comp) -> bool {
+        let protected =
+            |m: &[Marker]| -> Vec<(Tick, Tick)> { m.iter().filter(|m| m.protected && m.duration > Tick::ZERO).map(|m| (m.time, m.duration)).collect() };
+        if protected(&self.markers) != protected(&o.markers) {
+            return false;
+        }
+        let mut c = self.clone();
+        c.markers = o.markers.clone();
+        for (a, b) in c.layers.iter_mut().zip(&o.layers) {
+            a.markers = b.markers.clone();
+            a.markers_locked = b.markers_locked;
+        }
+        c.same_pixels(o)
+    }
+
+    /// The comp with those switches and the Resolution at their defaults (borrowed when they
+    /// already are), for keys that hash the whole comp.
+    pub fn pixel_form(&self) -> std::borrow::Cow<'_, Comp> {
+        if !self.hide_shy && self.resolution.is_auto() && self.layers.iter().all(|l| l.switches == l.switches.pixels()) {
+            return std::borrow::Cow::Borrowed(self);
+        }
+        let mut c = self.clone();
+        c.hide_shy = false;
+        c.resolution = Resolution::Auto;
+        for l in &mut c.layers {
+            l.switches = l.switches.pixels();
+        }
+        std::borrow::Cow::Owned(c)
+    }
+}
diff --git a/crates/project/src/footage.rs b/crates/project/src/footage.rs
new file mode 100644
index 000000000..391b1e17c
--- /dev/null
+++ b/crates/project/src/footage.rs
@@ -0,0 +1,229 @@
+use super::settings::yes;
+use super::{ColorSpace, Deserialize, FrameRate, Serialize, Tick};
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum FootageKind {
+    #[default]
+    Video,
+    Still,
+    Sequence,
+    Audio,
+    /// A 3D model (glTF 2.0 / OBJ), placed as a model layer.
+    Model,
+    /// A data file (JSON, CSV, TSV) for data-driven animation: read by expressions through
+    /// `footage(name).sourceData` / `sourceText` / `dataValue`; it has no pixels.
+    Data,
+}
+
+/// Interpret Footage ▸ Fields and Pulldown ▸ Separate Fields.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub enum FieldOrder {
+    /// Progressive frames.
+    #[default]
+    Off,
+    /// Interlaced, upper (odd) field first: each field becomes a frame at twice the rate.
+    UpperFirst,
+    LowerFirst,
+}
+
+impl FieldOrder {
+    pub fn label(self) -> &'static str {
+        match self {
+            FieldOrder::Off => "Off",
+            FieldOrder::UpperFirst => "Upper Field First",
+            FieldOrder::LowerFirst => "Lower Field First",
+        }
+    }
+    pub fn parse(s: &str) -> Option<FieldOrder> {
+        match s.to_ascii_lowercase().replace([' ', '_', '-'], "").as_str() {
+            "off" | "none" | "progressive" => Some(FieldOrder::Off),
+            "upper" | "upperfirst" | "upperfieldfirst" => Some(FieldOrder::UpperFirst),
+            "lower" | "lowerfirst" | "lowerfieldfirst" => Some(FieldOrder::LowerFirst),
+            _ => None,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum AlphaMode {
+    #[default]
+    Straight,
+    Premultiplied,
+    Ignore,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Footage {
+    pub path: String,
+    pub kind: FootageKind,
+    pub width: u32,
+    pub height: u32,
+    pub pixel_aspect: f64,
+    pub frame_rate: FrameRate,
+    /// Native rate before "Conform to frame rate".
+    #[serde(default)]
+    pub native_rate: Option<FrameRate>,
+    pub duration: Tick,
+    pub has_video: bool,
+    pub has_audio: bool,
+    pub alpha: AlphaMode,
+    #[serde(default)]
+    pub premul_color: [f32; 3],
+    #[serde(default = "one")]
+    pub loop_count: u32,
+    #[serde(default)]
+    pub codec: String,
+    #[serde(default)]
+    pub missing: bool,
+    /// Image sequence files (when kind = Sequence).
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub sequence: Vec<String>,
+    /// Colour profile (from the file's metadata, or Interpret Footage). `None` = sRGB.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub color_profile: Option<ColorSpace>,
+    /// One layer of a layered file (Photoshop) instead of its merged image.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub layer: Option<SourceLayer>,
+    /// Interpret Footage ▸ Fields and Pulldown ▸ Separate Fields.
+    #[serde(default, skip_serializing_if = "is_default")]
+    pub fields: FieldOrder,
+    /// Interpret Footage ▸ Alpha ▸ Invert Alpha.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub invert_alpha: bool,
+    /// Interpret Footage ▸ Color ▸ Interpret As Linear Light: the file's values are linear.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub linear_light: bool,
+    /// Interpret Footage ▸ Color ▸ Preserve RGB: the file's values enter the composition
+    /// unconverted. Float footage (OpenEXR, float TIFF) is not sRGB-encoded on decode, and the
+    /// colour profile, Interpret As Linear Light and the working space don't apply.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub preserve_rgb: bool,
+    /// Data footage ([`FootageKind::Data`]): the file's text (JSON, CSV or TSV), kept in the
+    /// project so expressions read it everywhere (and on the web).
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub data: Option<String>,
+    /// PDF / Illustrator footage: the page shown (0-based; File ▸ Import ▸ Page).
+    #[serde(default, skip_serializing_if = "is_default")]
+    pub page: u32,
+    /// Image sequences imported with Force Alphabetical Order: the files play one after another
+    /// and their numbering doesn't count (otherwise a gap in it shows a placeholder, as in After
+    /// Effects; [`sequence`]).
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub alphabetical: bool,
+    /// Interpret Footage ▸ Start Timecode ▸ Override Start: the frame (at the footage's frame
+    /// rate) its timecode shows at its first frame. `None` = Use Source File Timecode (0: file
+    /// timecode isn't read). It only relabels source time, as in After Effects.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub start_timecode: Option<i64>,
+}
+
+fn is_default<T: Default + PartialEq>(v: &T) -> bool {
+    *v == T::default()
+}
+
+impl Default for Footage {
+    fn default() -> Self {
+        Footage {
+            path: String::new(),
+            kind: FootageKind::Still,
+            width: 0,
+            height: 0,
+            pixel_aspect: 1.0,
+            frame_rate: FrameRate::FPS_30,
+            native_rate: None,
+            duration: Tick::ZERO,
+            has_video: false,
+            has_audio: false,
+            alpha: AlphaMode::Straight,
+            premul_color: [0.0; 3],
+            loop_count: 1,
+            codec: String::new(),
+            missing: false,
+            sequence: vec![],
+            color_profile: None,
+            fields: FieldOrder::Off,
+            invert_alpha: false,
+            linear_light: false,
+            preserve_rgb: false,
+            data: None,
+            layer: None,
+            page: 0,
+            alphabetical: false,
+            start_timecode: None,
+        }
+    }
+}
+
+impl Footage {
+    /// Interpret As Linear Light applies (Preserve RGB passes the file's values through).
+    pub fn linear_light_applies(&self) -> bool {
+        self.linear_light && !self.preserve_rgb
+    }
+
+    /// How long the footage plays: its duration times Interpret Footage ▸ Loop.
+    pub fn looped_duration(&self) -> Tick {
+        Tick(self.duration.0.saturating_mul(self.loop_count.max(1) as i64))
+    }
+
+    /// Source time as the footage's timecode: its frame `frame` from Start Timecode
+    /// (`0:00:41:20`), as the Footage panel shows it.
+    pub fn timecode(&self, frame: i64) -> String {
+        effectcraft_time::format_timecode_ae(frame.saturating_add(self.start_timecode.unwrap_or(0)), self.frame_rate, false)
+    }
+
+    /// The data format of data footage: `json`, `csv` or `tsv` (from the file extension).
+    pub fn data_format(&self) -> Option<&'static str> {
+        if self.kind != FootageKind::Data {
+            return None;
+        }
+        let ext = std::path::Path::new(&self.path).extension().and_then(std::ffi::OsStr::to_str).unwrap_or("").to_ascii_lowercase();
+        Some(match ext.as_str() {
+            "csv" => "csv",
+            "tsv" | "tab" => "tsv",
+            _ => "json",
+        })
+    }
+}
+
+/// A proxy: a stand-in file used instead of a footage item or composition (File ▸ Set Proxy /
+/// Create Proxy), when its Use Proxy switch is on and the render's Proxy Use allows it.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Proxy {
+    /// The proxy's footage (path, size, rate…; File ▸ Interpret Footage ▸ Proxy edits it).
+    pub footage: Footage,
+    /// Use Proxy (the Project panel's proxy indicator: filled = in use, hollow = set but off).
+    #[serde(default = "yes")]
+    pub enabled: bool,
+}
+
+/// A layer of a layered still (a Photoshop document, or a PDF / Illustrator / EPS file) used as
+/// footage (File ▸ Import ▸ Composition / Composition – Retain Layer Sizes, or Choose Layer).
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub struct SourceLayer {
+    /// Layer record index in the file (bottom of the stack = 0).
+    pub index: u32,
+    pub name: String,
+    /// The footage is the layer's own bounds (Retain Layer Sizes) rather than the document size.
+    #[serde(default)]
+    pub layer_size: bool,
+    /// A Photoshop smart object: the unique id of its embedded file (linked layer data), which
+    /// is the footage instead of the layer's pixels.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub embedded: Option<String>,
+    /// A smart object with a perspective quad or a warp: the footage is its embedded file baked
+    /// as placed (warped and pinned to its corners) over the placed bounds in document space.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub placed: bool,
+}
+
+fn one() -> u32 {
+    1
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Solid {
+    pub color: [f32; 3],
+    pub width: u32,
+    pub height: u32,
+    pub pixel_aspect: f64,
+}
diff --git a/crates/project/src/item.rs b/crates/project/src/item.rs
new file mode 100644
index 000000000..3f53bc823
--- /dev/null
+++ b/crates/project/src/item.rs
@@ -0,0 +1,308 @@
+use super::comp::Comp;
+use super::footage::{Footage, FootageKind, Proxy, Solid};
+use super::layer::LayerSource;
+use super::settings::{APP_VERSION, ProjectError, ProjectSettings, SCHEMA_VERSION, SavedView};
+use super::{Arc, BTreeMap, Deserialize, FrameRate, Label, Project, Serialize, Tick, file_check, limits};
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
+pub struct ItemId(pub u64);
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
+pub struct LayerId(pub u64);
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[serde(tag = "type")]
+#[allow(clippy::large_enum_variant)]
+pub enum ItemKind {
+    Folder,
+    Comp(Arc<Comp>),
+    Footage(Footage),
+    Solid(Solid),
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Item {
+    pub id: ItemId,
+    pub name: String,
+    pub label: Label,
+    #[serde(default)]
+    pub comment: String,
+    /// Containing folder (None = project root).
+    #[serde(default)]
+    pub parent: Option<ItemId>,
+    pub kind: ItemKind,
+    /// The item's proxy (footage and compositions).
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub proxy: Option<Box<Proxy>>,
+}
+
+impl Item {
+    pub fn type_name(&self) -> &'static str {
+        match &self.kind {
+            ItemKind::Folder => "Folder",
+            ItemKind::Comp(_) => "Composition",
+            ItemKind::Footage(f) => match f.kind {
+                FootageKind::Video => "Video",
+                FootageKind::Still => "Image",
+                FootageKind::Sequence => "Image Sequence",
+                FootageKind::Audio => "Audio",
+                FootageKind::Model => "3D Model",
+                FootageKind::Data => "Data",
+            },
+            ItemKind::Solid(_) => "Solid",
+        }
+    }
+    pub fn as_comp(&self) -> Option<&Comp> {
+        if let ItemKind::Comp(c) = &self.kind { Some(c) } else { None }
+    }
+    pub fn is_folder(&self) -> bool {
+        matches!(self.kind, ItemKind::Folder)
+    }
+    /// (width, height) for visual items.
+    pub fn dimensions(&self) -> Option<(u32, u32)> {
+        match &self.kind {
+            ItemKind::Comp(c) => Some((c.width, c.height)),
+            ItemKind::Footage(f) if f.has_video => Some((f.width, f.height)),
+            ItemKind::Solid(s) => Some((s.width, s.height)),
+            _ => None,
+        }
+    }
+    pub fn duration(&self) -> Option<Tick> {
+        match &self.kind {
+            ItemKind::Comp(c) => Some(c.duration),
+            ItemKind::Footage(f) if f.kind != FootageKind::Still => Some(f.looped_duration()),
+            _ => None,
+        }
+    }
+    pub fn frame_rate(&self) -> Option<FrameRate> {
+        match &self.kind {
+            ItemKind::Comp(c) => Some(c.frame_rate),
+            ItemKind::Footage(f) if f.kind == FootageKind::Video || f.kind == FootageKind::Sequence => Some(f.frame_rate),
+            _ => None,
+        }
+    }
+}
+
+impl Default for Project {
+    fn default() -> Self {
+        Project {
+            schema: SCHEMA_VERSION,
+            settings: ProjectSettings::default(),
+            items: BTreeMap::new(),
+            next_id: 1,
+            render_queue: Vec::new(),
+            render_templates: Default::default(),
+            render_prefs: Default::default(),
+        }
+    }
+}
+
+impl Project {
+    /// Allocate an id (items, layers and property uids share one counter).
+    pub fn alloc(&mut self) -> u64 {
+        let id = self.next_id;
+        self.next_id += 1;
+        id
+    }
+    pub fn item(&self, id: ItemId) -> Option<&Item> {
+        self.items.get(&id)
+    }
+    pub fn item_mut(&mut self, id: ItemId) -> Option<&mut Item> {
+        self.items.get_mut(&id)
+    }
+    pub fn comp(&self, id: ItemId) -> Option<&Comp> {
+        self.items.get(&id)?.as_comp()
+    }
+    /// A shared handle on a comp: a snapshot that costs a reference count, not a deep copy of
+    /// its layers (frontends hold one across a frame instead of cloning the comp).
+    pub fn comp_arc(&self, id: ItemId) -> Option<Arc<Comp>> {
+        match &self.items.get(&id)?.kind {
+            ItemKind::Comp(c) => Some(c.clone()),
+            _ => None,
+        }
+    }
+    /// Mutable comp (copy-on-write).
+    pub fn comp_mut(&mut self, id: ItemId) -> Option<&mut Comp> {
+        match &mut self.items.get_mut(&id)?.kind {
+            ItemKind::Comp(c) => Some(Arc::make_mut(c)),
+            _ => None,
+        }
+    }
+    /// Adds an item; its size, frame rate and the like are brought within [`limits`] first.
+    pub fn add_item(&mut self, name: &str, label: Label, parent: Option<ItemId>, mut kind: ItemKind) -> ItemId {
+        limits::repair_kind(name, &mut kind, &mut vec![]);
+        let id = ItemId(self.alloc());
+        self.items.insert(id, Item { id, name: name.into(), label, comment: String::new(), parent, kind, proxy: None });
+        id
+    }
+    /// Children of a folder (None = root), folders first then by name.
+    pub fn children(&self, folder: Option<ItemId>) -> Vec<&Item> {
+        let mut v: Vec<&Item> = self.items.values().filter(|i| i.parent == folder).collect();
+        v.sort_by(|a, b| b.is_folder().cmp(&a.is_folder()).then_with(|| a.name.to_lowercase().cmp(&b.name.to_lowercase())));
+        v
+    }
+    pub fn comps(&self) -> impl Iterator<Item = (&ItemId, &Comp)> {
+        self.items.iter().filter_map(|(id, i)| i.as_comp().map(|c| (id, c)))
+    }
+    pub fn find_by_name(&self, name: &str) -> Option<&Item> {
+        self.items.values().find(|i| i.name == name)
+    }
+    /// A numbered name for a copy of `base` that no project item has (Edit ▸ Duplicate): its
+    /// trailing number is dropped and the lowest free one from 2 is added (`Comp 1` → `Comp 2`,
+    /// `Name` → `Name 2`, then `Name 3`). Items for which `ignore` holds don't count.
+    pub fn numbered_item_name(&self, base: &str, ignore: impl Fn(&Item) -> bool) -> String {
+        let stem = base.trim_end_matches(|c: char| c.is_ascii_digit()).trim_end();
+        let taken = |n: &str| self.items.values().any(|i| i.name == n && !ignore(i));
+        (2u64..).map(|k| format!("{stem} {k}")).find(|n| !taken(n)).unwrap_or_default()
+    }
+    /// `base` when no project item has that name, else the next free numbered name as
+    /// [`Project::numbered_item_name`] gives it. Items for which `ignore` holds don't count.
+    pub fn unique_item_name(&self, base: &str, ignore: impl Fn(&Item) -> bool) -> String {
+        if self.items.values().any(|i| i.name == base && !ignore(i)) { self.numbered_item_name(base, ignore) } else { base.to_string() }
+    }
+    pub fn folder_named(&self, name: &str) -> Option<ItemId> {
+        self.items.values().find(|i| i.is_folder() && i.name == name).map(|i| i.id)
+    }
+    /// Find the comp that contains `layer`.
+    pub fn comp_of_layer(&self, layer: LayerId) -> Option<ItemId> {
+        self.comps().find(|(_, c)| c.layer(layer).is_some()).map(|(id, _)| *id)
+    }
+    /// The compositions whose layers use `item` as their source (footage, solid, 3D model or
+    /// precomp), each with how many of its layers do, ordered by comp name then id. Only direct
+    /// layers count, as in After Effects' Project panel ("used 3 times"): a solid inside a precomp
+    /// is used by the precomp, not by the comps that nest it. The total is the sum of the counts.
+    pub fn item_users(&self, item: ItemId) -> Vec<(ItemId, usize)> {
+        let mut users: Vec<(ItemId, String, usize)> = self
+            .items
+            .iter()
+            .filter_map(|(id, it)| {
+                let comp = it.as_comp()?;
+                let n = comp.layers.iter().filter(|l| l.source.item() == Some(item)).count();
+                (n > 0).then(|| (*id, it.name.to_lowercase(), n))
+            })
+            .collect();
+        users.sort_by(|a, b| a.1.cmp(&b.1).then(a.0.cmp(&b.0)));
+        users.into_iter().map(|(id, _, n)| (id, n)).collect()
+    }
+    /// Whether comp `inner` is (transitively) nested inside comp `outer` (to prevent cycles).
+    pub fn comp_contains(&self, outer: ItemId, inner: ItemId) -> bool {
+        // A walk with a stack and a visited set rather than recursion (#1237): a damaged project
+        // may hold a precomp cycle that doesn't pass `inner` (recursion never ended), a long
+        // chain must not use up the call stack, and comps shared by many paths are visited once
+        // (recursion re-walked them for every path).
+        if outer == inner {
+            return true;
+        }
+        let mut seen = std::collections::HashSet::new();
+        let mut stack = vec![outer];
+        while let Some(id) = stack.pop() {
+            if !seen.insert(id) {
+                continue;
+            }
+            let Some(c) = self.comp(id) else { continue };
+            for l in &c.layers {
+                if let LayerSource::Comp { item } = l.source {
+                    if item == inner {
+                        return true;
+                    }
+                    if !seen.contains(&item) {
+                        stack.push(item);
+                    }
+                }
+            }
+        }
+        false
+    }
+    /// Make sure `next_id` exceeds every id in the project (after loading or merging).
+    pub fn fix_next_id(&mut self) {
+        let mut m = self.next_id;
+        for (id, it) in &self.items {
+            // Saturating: a damaged file's ids must not overflow (the import then refuses it).
+            m = m.max(id.0.saturating_add(1));
+            if let ItemKind::Comp(c) = &it.kind {
+                for l in &c.layers {
+                    m = m.max(l.id.0.saturating_add(1)).max(l.props.max_uid().saturating_add(1));
+                }
+            }
+        }
+        self.next_id = m;
+    }
+    /// Whether `other` holds the same content. An allocated id counts (an edit may hand it out
+    /// beyond the project, so it must stay taken). Shared compositions compare by pointer first,
+    /// so after a copy-on-write edit only the comps it touched are compared field by field.
+    pub fn same_content(&self, other: &Project) -> bool {
+        let item_eq = |a: &Item, b: &Item| {
+            let kind = match (&a.kind, &b.kind) {
+                (ItemKind::Comp(x), ItemKind::Comp(y)) => Arc::ptr_eq(x, y) || x == y,
+                (x, y) => x == y,
+            };
+            kind && a.id == b.id && a.name == b.name && a.label == b.label && a.comment == b.comment && a.parent == b.parent && a.proxy == b.proxy
+        };
+        self.schema == other.schema
+            && self.next_id == other.next_id
+            && self.settings == other.settings
+            && self.items.len() == other.items.len()
+            && self.items.iter().zip(&other.items).all(|((ka, a), (kb, b))| ka == kb && item_eq(a, b))
+            && self.render_queue == other.render_queue
+            && self.render_templates == other.render_templates
+            && self.render_prefs == other.render_prefs
+    }
+    /// The project file's text: the project with the version that wrote it (`savedBy`), checked
+    /// to read back, so a save never writes a file that can't be opened. Values JSON can't hold
+    /// (NaN or infinity, written as `null`, and nesting too deep to parse) are refused on every
+    /// save; debug builds also read the text back.
+    pub fn to_file_json(&self) -> Result<String, ProjectError> {
+        self.to_file_json_with_view(&SavedView::default())
+    }
+    /// [`Project::to_file_json`] that also records the open compositions ([`SavedView`]).
+    pub fn to_file_json_with_view(&self, view: &SavedView) -> Result<String, ProjectError> {
+        if self.schema > SCHEMA_VERSION {
+            return Err(ProjectError::Invalid(format!(
+                "the project can't be saved: it holds a value a project file can't store (project schema {} is newer than this version supports ({SCHEMA_VERSION}))",
+                self.schema
+            )));
+        }
+        #[derive(Serialize)]
+        struct File<'a> {
+            #[serde(rename = "savedBy")]
+            saved_by: &'a str,
+            #[serde(flatten)]
+            view: &'a SavedView,
+            #[serde(flatten)]
+            project: &'a Project,
+        }
+        let file = File { saved_by: APP_VERSION, view, project: self };
+        file_check::check(&file)
+            .map_err(|e| ProjectError::Invalid(format!("the project can't be saved: it holds a value a project file can't store ({e})")))?;
+        let text = serde_json::to_string_pretty(&file).map_err(|e| ProjectError::Invalid(format!("the project can't be saved: {e}")))?;
+        #[cfg(debug_assertions)]
+        Project::from_json(&text)
+            .map_err(|e| ProjectError::Invalid(format!("the project can't be saved: it holds a value a project file can't store ({e})")))?;
+        Ok(text)
+    }
+    pub fn to_json(&self) -> String {
+        serde_json::to_string_pretty(self).unwrap_or_default()
+    }
+    /// [`Project::to_json`] without indentation: smaller and faster (auto-saves).
+    pub fn to_json_compact(&self) -> String {
+        serde_json::to_string(self).unwrap_or_default()
+    }
+    pub fn from_json(s: &str) -> Result<Project, ProjectError> {
+        Project::from_json_repaired(s).map(|(p, _)| p)
+    }
+    /// [`Project::from_json`], also returning one line per value that was out of [`limits`] and
+    /// was corrected (a composition of a billion pixels, a zero frame rate…), so a corrupt or
+    /// hostile file still opens, within bounds, and the user can be told what changed.
+    pub fn from_json_repaired(s: &str) -> Result<(Project, Vec<String>), ProjectError> {
+        let mut p: Project = serde_json::from_str(s).map_err(|e| ProjectError::Invalid(e.to_string()))?;
+        if p.schema > SCHEMA_VERSION {
+            return Err(ProjectError::Invalid(format!("project schema {} is newer than this version supports ({SCHEMA_VERSION})", p.schema)));
+        }
+        p.fix_next_id();
+        let mut notes = vec![];
+        for item in p.items.values_mut() {
+            limits::repair_item(item, &mut notes);
+        }
+        Ok((p, notes))
+    }
+}
diff --git a/crates/project/src/layer.rs b/crates/project/src/layer.rs
new file mode 100644
index 000000000..25e2da7c4
--- /dev/null
+++ b/crates/project/src/layer.rs
@@ -0,0 +1,370 @@
+use super::item::{ItemId, LayerId};
+use super::settings::Marker;
+use super::{BlendMode, Deserialize, Label, PropGroup, Serialize, Tick};
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum LightKind {
+    Parallel,
+    Spot,
+    #[default]
+    Point,
+    Ambient,
+    Environment,
+}
+
+impl LightKind {
+    pub const ALL: [LightKind; 5] = [LightKind::Parallel, LightKind::Spot, LightKind::Point, LightKind::Ambient, LightKind::Environment];
+    pub fn label(self) -> &'static str {
+        match self {
+            LightKind::Parallel => "Parallel",
+            LightKind::Spot => "Spot",
+            LightKind::Point => "Point",
+            LightKind::Ambient => "Ambient",
+            LightKind::Environment => "Environment",
+        }
+    }
+}
+
+/// A parametric 3D primitive (Layer ▸ New ▸ Cube/Sphere/Plane/Torus/Cone/Cylinder).
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub enum PrimitiveKind {
+    #[default]
+    Cube,
+    Sphere,
+    Plane,
+    Torus,
+    Cone,
+    Cylinder,
+}
+
+impl PrimitiveKind {
+    pub const ALL: [PrimitiveKind; 6] =
+        [PrimitiveKind::Cube, PrimitiveKind::Sphere, PrimitiveKind::Plane, PrimitiveKind::Torus, PrimitiveKind::Cone, PrimitiveKind::Cylinder];
+    pub fn label(self) -> &'static str {
+        match self {
+            PrimitiveKind::Cube => "Cube",
+            PrimitiveKind::Sphere => "Sphere",
+            PrimitiveKind::Plane => "Plane",
+            PrimitiveKind::Torus => "Torus",
+            PrimitiveKind::Cone => "Cone",
+            PrimitiveKind::Cylinder => "Cylinder",
+        }
+    }
+    pub fn parse(s: &str) -> Option<PrimitiveKind> {
+        PrimitiveKind::ALL.into_iter().find(|k| k.label().eq_ignore_ascii_case(s.trim()))
+    }
+}
+
+/// What a layer shows.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[serde(tag = "type")]
+pub enum LayerSource {
+    /// Footage item (video, still, sequence, audio).
+    Footage {
+        item: ItemId,
+    },
+    /// Nested composition (precomp).
+    Comp {
+        item: ItemId,
+    },
+    /// Solid item (solids also back adjustment layers).
+    Solid {
+        item: ItemId,
+    },
+    Text,
+    Shape,
+    Null,
+    Camera,
+    Light {
+        kind: LightKind,
+    },
+    /// An imported 3D model (a footage item of kind [`FootageKind::Model`]; Advanced 3D).
+    Model {
+        item: ItemId,
+    },
+    /// A parametric 3D primitive (Advanced 3D).
+    Primitive {
+        kind: PrimitiveKind,
+    },
+}
+
+impl LayerSource {
+    pub fn item(&self) -> Option<ItemId> {
+        match self {
+            LayerSource::Footage { item } | LayerSource::Comp { item } | LayerSource::Solid { item } | LayerSource::Model { item } => Some(*item),
+            _ => None,
+        }
+    }
+    pub fn type_name(&self) -> &'static str {
+        match self {
+            LayerSource::Footage { .. } => "Footage",
+            LayerSource::Comp { .. } => "Composition",
+            LayerSource::Solid { .. } => "Solid",
+            LayerSource::Text => "Text",
+            LayerSource::Shape => "Shape",
+            LayerSource::Null => "Null",
+            LayerSource::Camera => "Camera",
+            LayerSource::Light { .. } => "Light",
+            LayerSource::Model { .. } => "3D Model",
+            LayerSource::Primitive { .. } => "3D Primitive",
+        }
+    }
+    /// Layers with pixels (cameras, lights and nulls have none).
+    pub fn is_av(&self) -> bool {
+        !matches!(self, LayerSource::Camera | LayerSource::Light { .. } | LayerSource::Null)
+    }
+    /// A 3D model or primitive layer (meshes; drawn by the Advanced 3D renderer).
+    pub fn is_model(&self) -> bool {
+        matches!(self, LayerSource::Model { .. } | LayerSource::Primitive { .. })
+    }
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Quality {
+    #[default]
+    Best,
+    Draft,
+    Wireframe,
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Sampling {
+    #[default]
+    Bilinear,
+    Bicubic,
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum FrameBlend {
+    #[default]
+    Off,
+    FrameMix,
+    PixelMotion,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Switches {
+    pub video: bool,
+    pub audio: bool,
+    pub solo: bool,
+    pub locked: bool,
+    pub shy: bool,
+    /// Collapse transformations (precomps) / continuously rasterize (vector layers).
+    pub collapse: bool,
+    pub quality: Quality,
+    pub sampling: Sampling,
+    pub effects: bool,
+    pub frame_blend: FrameBlend,
+    pub motion_blur: bool,
+    pub adjustment: bool,
+    pub three_d: bool,
+    pub guide: bool,
+}
+
+impl Default for Switches {
+    fn default() -> Self {
+        Switches {
+            video: true,
+            audio: true,
+            solo: false,
+            locked: false,
+            shy: false,
+            collapse: false,
+            quality: Quality::Best,
+            sampling: Sampling::Bilinear,
+            effects: true,
+            frame_blend: FrameBlend::Off,
+            motion_blur: false,
+            adjustment: false,
+            three_d: false,
+            guide: false,
+        }
+    }
+}
+
+// What a frame's pixels depend on. Caches key on it: the Audio, Lock and Shy switches and Hide
+// Shy Layers don't change pixels, so toggling them keeps cached frames (#103).
+
+impl Switches {
+    /// These switches with Audio, Lock and Shy at their defaults.
+    pub fn pixels(&self) -> Switches {
+        Switches { audio: true, locked: false, shy: false, ..self.clone() }
+    }
+}
+
+impl Layer {
+    /// Draws the same pixels as `o`: equal but for the Audio, Lock and Shy switches.
+    pub fn same_pixels(&self, o: &Layer) -> bool {
+        // Every field (no `..`: a new field must be considered here); the property tree last.
+        let Layer {
+            id,
+            name,
+            source,
+            label,
+            comment,
+            start_time,
+            in_point,
+            out_point,
+            stretch,
+            switches,
+            blend_mode,
+            preserve_transparency,
+            track_matte,
+            parent,
+            markers,
+            markers_locked,
+            auto_orient,
+            environment,
+            environment_background,
+            props,
+        } = self;
+        *id == o.id
+            && *name == o.name
+            && *source == o.source
+            && *label == o.label
+            && *comment == o.comment
+            && *start_time == o.start_time
+            && *in_point == o.in_point
+            && *out_point == o.out_point
+            && *stretch == o.stretch
+            && switches.pixels() == o.switches.pixels()
+            && *blend_mode == o.blend_mode
+            && *preserve_transparency == o.preserve_transparency
+            && *track_matte == o.track_matte
+            && *parent == o.parent
+            && *markers == o.markers
+            && *markers_locked == o.markers_locked
+            && *auto_orient == o.auto_orient
+            && *environment == o.environment
+            && *environment_background == o.environment_background
+            && *props == o.props
+    }
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum MatteKind {
+    #[default]
+    Alpha,
+    AlphaInverted,
+    Luma,
+    LumaInverted,
+}
+
+impl MatteKind {
+    pub const ALL: [MatteKind; 4] = [MatteKind::Alpha, MatteKind::AlphaInverted, MatteKind::Luma, MatteKind::LumaInverted];
+    pub fn label(self) -> &'static str {
+        match self {
+            MatteKind::Alpha => "Alpha Matte",
+            MatteKind::AlphaInverted => "Alpha Inverted Matte",
+            MatteKind::Luma => "Luma Matte",
+            MatteKind::LumaInverted => "Luma Inverted Matte",
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct TrackMatte {
+    pub layer: LayerId,
+    pub kind: MatteKind,
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum AutoOrient {
+    #[default]
+    Off,
+    AlongPath,
+    TowardsCamera,
+    TowardsPointOfInterest,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Layer {
+    pub id: LayerId,
+    pub name: String,
+    pub source: LayerSource,
+    pub label: Label,
+    #[serde(default)]
+    pub comment: String,
+    /// Comp time where the layer's time 0 sits.
+    pub start_time: Tick,
+    /// Visible span in comp time.
+    pub in_point: Tick,
+    pub out_point: Tick,
+    /// Time stretch in percent (100 = normal, negative = reversed).
+    pub stretch: f64,
+    pub switches: Switches,
+    pub blend_mode: BlendMode,
+    #[serde(default)]
+    pub preserve_transparency: bool,
+    #[serde(default)]
+    pub track_matte: Option<TrackMatte>,
+    #[serde(default)]
+    pub parent: Option<LayerId>,
+    #[serde(default)]
+    pub markers: Vec<Marker>,
+    /// Layer ▸ Markers ▸ Lock Markers.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub markers_locked: bool,
+    #[serde(default)]
+    pub auto_orient: AutoOrient,
+    /// Layer ▸ Environment Layer: the layer is the environment (image-based light and
+    /// reflections) of Advanced 3D comps instead of being drawn.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub environment: bool,
+    /// Layer ▸ Light ▸ Create Environment Light Background Layer: the layer's (equirectangular)
+    /// image is drawn as the 3D scene's backdrop, seen through the camera, instead of as a card.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub environment_background: bool,
+    /// The property tree (Masks, Effects, Transform, Text, Contents, Camera/Light options…).
+    pub props: PropGroup,
+}
+
+impl Layer {
+    pub fn is_active_at(&self, t: Tick) -> bool {
+        t >= self.in_point && t < self.out_point
+    }
+
+    /// Layer time for a comp time (stretch-aware).
+    pub fn layer_time(&self, comp_t: Tick) -> Tick {
+        let d = comp_t - self.start_time;
+        if (self.stretch - 100.0).abs() < 1e-9 { d } else { Tick((d.0 as f64 * 100.0 / self.stretch) as i64) }
+    }
+
+    /// Comp time for a layer time.
+    pub fn comp_time(&self, layer_t: Tick) -> Tick {
+        if (self.stretch - 100.0).abs() < 1e-9 { self.start_time + layer_t } else { self.start_time + Tick((layer_t.0 as f64 * self.stretch / 100.0) as i64) }
+    }
+
+    pub fn transform(&self) -> Option<&PropGroup> {
+        self.props.sub("transform")
+    }
+
+    pub fn transform_mut(&mut self) -> Option<&mut PropGroup> {
+        self.props.sub_mut("transform")
+    }
+
+    pub fn effects(&self) -> Option<&PropGroup> {
+        self.props.sub("effects")
+    }
+
+    pub fn masks(&self) -> Option<&PropGroup> {
+        self.props.sub("masks")
+    }
+
+    pub fn is_camera(&self) -> bool {
+        matches!(self.source, LayerSource::Camera)
+    }
+
+    pub fn is_light(&self) -> bool {
+        matches!(self.source, LayerSource::Light { .. })
+    }
+
+    /// The layer participates in 3D (3D switch, or cameras/lights which are always 3D).
+    pub fn is_3d(&self) -> bool {
+        self.switches.three_d || self.is_camera() || self.is_light()
+    }
+
+    pub fn has_video(&self) -> bool {
+        self.source.is_av() && self.switches.video
+    }
+}
diff --git a/crates/project/src/lib.rs b/crates/project/src/lib.rs
index 822fc7f75..8e1409c37 100644
--- a/crates/project/src/lib.rs
+++ b/crates/project/src/lib.rs
@@ -29,1393 +29,20 @@ use serde::{Deserialize, Serialize};
 pub use effectcraft_keyframe as keyframe;
 pub use effectcraft_keyframe::{Keyframe, Value};
 
-/// The project file schema. 2: effects on layers without a source rectangle (shape, text)
-/// measure positions from the top-left of their comp-sized bounds (effect space), not from
-/// the layer's origin; projects from schema 1 are converted when opened (#227).
-pub const SCHEMA_VERSION: u32 = 2;
-
-/// The first schema in which effect positions are in effect space (see [`SCHEMA_VERSION`]).
-pub const SCHEMA_EFFECT_SPACE: u32 = 2;
-
-/// The EffectCraft version, written into project files as `savedBy`.
-pub const APP_VERSION: &str = env!("CARGO_PKG_VERSION");
-
-/// The EffectCraft version that wrote a project file (its `savedBy`), when it says.
-pub fn saved_by(text: &str) -> Option<String> {
-    #[derive(Deserialize)]
-    struct Meta {
-        #[serde(rename = "savedBy", default)]
-        saved_by: Option<String>,
-    }
-    serde_json::from_str::<Meta>(text).ok()?.saved_by
-}
-
-/// The compositions that were open when a project file was saved and their current times
-/// (`activeComp`, `openComps` and `compTimes` next to `savedBy`), so it reopens where it was left
-/// (#748, #1714). Editor state rather than project
-/// content: opening a comp doesn't make the project unsaved, and it isn't part of
-/// [`Project`]. Older files have none; older versions ignore it.
-#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize)]
-#[serde(rename_all = "camelCase")]
-pub struct SavedView {
-    /// The comp shown in the viewer and the Timeline.
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub active_comp: Option<ItemId>,
-    /// The open comps (Timeline tabs), in tab order.
-    #[serde(skip_serializing_if = "Vec::is_empty")]
-    pub open_comps: Vec<ItemId>,
-    /// Each comp's current time, so a project reopens on the frame it was saved at rather than
-    /// at 0, where its layers may not have started yet (#1714).
-    #[serde(skip_serializing_if = "BTreeMap::is_empty")]
-    pub comp_times: BTreeMap<ItemId, Tick>,
-}
-
-/// The view a project file was saved with ([`SavedView`]); empty for older files. Values that
-/// aren't ids are ignored (whether an id still names a comp is up to the caller).
-pub fn saved_view(text: &str) -> SavedView {
-    #[derive(Deserialize)]
-    struct Meta {
-        #[serde(rename = "activeComp", default)]
-        active_comp: Option<serde_json::Value>,
-        #[serde(rename = "openComps", default)]
-        open_comps: Option<serde_json::Value>,
-        #[serde(rename = "compTimes", default)]
-        comp_times: Option<serde_json::Value>,
-    }
-    let Ok(m) = serde_json::from_str::<Meta>(text) else { return SavedView::default() };
-    SavedView {
-        active_comp: m.active_comp.as_ref().and_then(serde_json::Value::as_u64).map(ItemId),
-        open_comps: m
-            .open_comps
-            .as_ref()
-            .and_then(serde_json::Value::as_array)
-            .map_or_else(Vec::new, |a| a.iter().filter_map(serde_json::Value::as_u64).map(ItemId).collect()),
-        comp_times: m
-            .comp_times
-            .as_ref()
-            .and_then(serde_json::Value::as_object)
-            .map_or_else(BTreeMap::new, |o| o.iter().filter_map(|(k, v)| Some((ItemId(k.parse().ok()?), Tick(v.as_i64()?)))).collect()),
-    }
-}
-
-/// Whether version `a` (`major.minor.patch`, pre-release suffixes ignored) is newer than `b`.
-pub fn is_newer_version(a: &str, b: &str) -> bool {
-    let parts = |v: &str| -> [u64; 3] {
-        let mut n = v.split(['-', '+']).next().unwrap_or("").split('.').map(|x| x.parse().unwrap_or(0));
-        [n.next().unwrap_or(0), n.next().unwrap_or(0), n.next().unwrap_or(0)]
-    };
-    parts(a) > parts(b)
-}
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
-pub struct ItemId(pub u64);
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
-pub struct LayerId(pub u64);
-
-#[derive(Debug, thiserror::Error)]
-pub enum ProjectError {
-    #[error("no item {0:?}")]
-    NoItem(ItemId),
-    #[error("item {0:?} is not a composition")]
-    NotComp(ItemId),
-    #[error("no layer {0:?}")]
-    NoLayer(LayerId),
-    #[error("no property `{0}`")]
-    NoProperty(String),
-    #[error("{0}")]
-    Invalid(String),
-}
-
-/// Project bit depth.
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum BitDepth {
-    #[default]
-    Bpc8,
-    Bpc16,
-    Bpc32,
-}
-
-impl BitDepth {
-    pub fn label(self) -> &'static str {
-        match self {
-            BitDepth::Bpc8 => "8 bpc",
-            BitDepth::Bpc16 => "16 bpc",
-            BitDepth::Bpc32 => "32 bpc",
-        }
-    }
-    pub fn next(self) -> BitDepth {
-        match self {
-            BitDepth::Bpc8 => BitDepth::Bpc16,
-            BitDepth::Bpc16 => BitDepth::Bpc32,
-            BitDepth::Bpc32 => BitDepth::Bpc8,
-        }
-    }
-    pub fn is_float(self) -> bool {
-        self == BitDepth::Bpc32
-    }
-    /// Quantisation levels per channel of the integer depths (8 bpc: 255; 16 bpc: 32768, After
-    /// Effects' "15 + 1" bit range), `None` for 32 bpc float.
-    pub fn levels(self) -> Option<f32> {
-        match self {
-            BitDepth::Bpc8 => Some(255.0),
-            BitDepth::Bpc16 => Some(32768.0),
-            BitDepth::Bpc32 => None,
-        }
-    }
-    pub fn bits(self) -> u32 {
-        match self {
-            BitDepth::Bpc8 => 8,
-            BitDepth::Bpc16 => 16,
-            BitDepth::Bpc32 => 32,
-        }
-    }
-}
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum TimeDisplayStyle {
-    #[default]
-    Timecode,
-    Frames,
-    /// Feet + Frames, 35 mm film (16 frames per foot).
-    Feet35,
-    /// Feet + Frames, 16 mm film (40 frames per foot).
-    Feet16,
-}
-
-impl TimeDisplayStyle {
-    /// Frames per foot of the Feet + Frames styles.
-    pub fn frames_per_foot(self) -> Option<i64> {
-        match self {
-            TimeDisplayStyle::Feet35 => Some(16),
-            TimeDisplayStyle::Feet16 => Some(40),
-            _ => None,
-        }
-    }
-    pub fn id(self) -> &'static str {
-        match self {
-            TimeDisplayStyle::Timecode => "timecode",
-            TimeDisplayStyle::Frames => "frames",
-            TimeDisplayStyle::Feet35 => "feet35",
-            TimeDisplayStyle::Feet16 => "feet16",
-        }
-    }
-    pub fn parse(s: &str) -> Option<TimeDisplayStyle> {
-        let k: String = s.chars().filter(char::is_ascii_alphanumeric).collect::<String>().to_ascii_lowercase();
-        match k.as_str() {
-            "timecode" => Some(TimeDisplayStyle::Timecode),
-            "frames" => Some(TimeDisplayStyle::Frames),
-            "feet35" | "feetframes" | "feetandframes" | "feet35mm" | "35mm" | "feetframes35mm" => Some(TimeDisplayStyle::Feet35),
-            "feet16" | "feet16mm" | "16mm" | "feetframes16mm" => Some(TimeDisplayStyle::Feet16),
-            _ => None,
-        }
-    }
-}
-
-/// Project Settings ▸ Color ▸ Color Engine.
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum ColorEngine {
-    /// Built-in colour management (ICC-style working spaces).
-    #[default]
-    Adobe,
-    /// OCIO managed, with the built-in configuration (ACES working spaces).
-    Ocio,
-}
-
-/// Project Settings ▸ Color ▸ HDR: how over-range (HDR) values reach a standard-dynamic-range
-/// display or output.
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum HdrMode {
-    /// Values above 1.0 clip.
-    #[default]
-    Clip,
-    /// Highlights above 80% are companded (an exponential knee) into the remaining range.
-    Compand,
-    /// Extended Reinhard tone mapping of luminance (white at 4.0).
-    ToneMap,
-}
-
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct ProjectSettings {
-    pub bit_depth: BitDepth,
-    /// Linearize Working Space: the working space uses linear light (1.0 gamma) for everything
-    /// (sources, effects, blending). Needs a working space.
-    pub linearize: bool,
-    /// Working Space (colour management). `None` = no colour management.
-    #[serde(default)]
-    pub working_space: Option<ColorSpace>,
-    /// Blend Colors Using 1.0 Gamma: layers blend in linear light (sources and effects stay in
-    /// the working space's encoding).
-    #[serde(default)]
-    pub blend_linear: bool,
-    pub time_display: TimeDisplayStyle,
-    /// Frame numbering starts at 0 (or 1).
-    pub frame_start: i64,
-    pub audio_sample_rate: u32,
-    /// Video Rendering and Effects ▸ Use: Mercury GPU Acceleration (`true`, the default; used
-    /// when a GPU adapter exists) or Mercury Software Only (`false`, the CPU compositor).
-    #[serde(default = "yes")]
-    pub gpu_acceleration: bool,
-    /// The project's comment (Metadata panel).
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub comment: String,
-    /// Color Engine (Adobe-style built-in or OCIO with ACES working spaces).
-    #[serde(default)]
-    pub color_engine: ColorEngine,
-    /// HDR handling for standard-dynamic-range output (display and renders).
-    #[serde(default)]
-    pub hdr: HdrMode,
-    /// The space the top-level comp is output in (renders and the viewer's source). `None` =
-    /// sRGB; Rec. 2100 PQ / HLG give HDR output.
-    #[serde(default)]
-    pub output_space: Option<ColorSpace>,
-    /// Working Gamma, 2.2 or 2.4 (`app.project.workingGamma`): with no working space, the curve
-    /// Interpret As Linear Light footage is encoded with and Blend Colors Using 1.0 Gamma
-    /// linearizes with: the sRGB curve at 2.2, a pure 2.4 power curve at 2.4. Ignored with a
-    /// working space (as in After Effects).
-    #[serde(default = "gamma_22")]
-    pub working_gamma: f64,
-}
-
-fn gamma_22() -> f64 {
-    2.2
-}
-
-impl ProjectSettings {
-    /// Working Gamma is 2.4 (anything else reads as 2.2).
-    pub fn working_gamma_24(&self) -> bool {
-        (self.working_gamma - 2.4).abs() < 0.05
-    }
-}
-
-impl Default for ProjectSettings {
-    fn default() -> Self {
-        ProjectSettings {
-            bit_depth: BitDepth::Bpc8,
-            linearize: false,
-            working_space: None,
-            blend_linear: false,
-            time_display: TimeDisplayStyle::Timecode,
-            frame_start: 0,
-            audio_sample_rate: 48_000,
-            gpu_acceleration: true,
-            comment: String::new(),
-            color_engine: ColorEngine::Adobe,
-            hdr: HdrMode::Clip,
-            output_space: None,
-            working_gamma: 2.2,
-        }
-    }
-}
-
-#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
-pub struct Marker {
-    pub time: Tick,
-    #[serde(default)]
-    pub duration: Tick,
-    #[serde(default)]
-    pub comment: String,
-    #[serde(default)]
-    pub label: Label,
-    #[serde(default)]
-    pub chapter: String,
-    #[serde(default)]
-    pub url: String,
-    #[serde(default)]
-    pub protected: bool,
-    /// Web link frame target (`_blank`, a frame name…).
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub frame_target: String,
-    /// Flash/video cue point (Event or Navigation) with name and parameters.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub cue_point: Option<CuePoint>,
-}
-
-/// A marker's cue point (Composition/Layer Marker dialog ▸ Cue Point).
-#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
-pub struct CuePoint {
-    pub name: String,
-    /// Navigation (true) or Event cue point.
-    #[serde(default)]
-    pub navigation: bool,
-    /// (name, value) parameter pairs.
-    #[serde(default)]
-    pub params: Vec<(String, String)>,
-}
-
-/// 3D renderer of a composition.
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum Renderer {
-    #[default]
-    Classic3D,
-    Advanced3D,
-}
-
-/// A composition's Resolution (the Composition panel's Resolution/Down Sample Factor popup, View ▸
-/// Resolution): how many of its pixels the viewer renders. Auto follows the magnification.
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum Resolution {
-    #[default]
-    Auto,
-    Full,
-    Half,
-    Third,
-    Quarter,
-    /// View ▸ Resolution ▸ Custom: render every n-th pixel (2..=40).
-    Custom(u8),
-}
-
-impl Resolution {
-    pub const ALL: [Resolution; 5] = [Resolution::Auto, Resolution::Full, Resolution::Half, Resolution::Third, Resolution::Quarter];
-    pub fn label(self) -> &'static str {
-        match self {
-            Resolution::Auto => "Auto",
-            Resolution::Full => "Full",
-            Resolution::Half => "Half",
-            Resolution::Third => "Third",
-            Resolution::Quarter => "Quarter",
-            Resolution::Custom(_) => "Custom",
-        }
-    }
-    pub fn is_auto(&self) -> bool {
-        *self == Resolution::Auto
-    }
-    /// The down-sample factor (render every n-th pixel); `None` for Auto.
-    pub fn factor(self) -> Option<u8> {
-        match self {
-            Resolution::Auto => None,
-            Resolution::Full => Some(1),
-            Resolution::Half => Some(2),
-            Resolution::Third => Some(3),
-            Resolution::Quarter => Some(4),
-            Resolution::Custom(n) => Some(n),
-        }
-    }
-    /// The resolution that renders every `n`-th pixel (1 = Full … 4 = Quarter; up to 40).
-    pub fn from_factor(n: u64) -> Resolution {
-        match n.clamp(1, 40) {
-            1 => Resolution::Full,
-            2 => Resolution::Half,
-            3 => Resolution::Third,
-            4 => Resolution::Quarter,
-            n => Resolution::Custom(n as u8),
-        }
-    }
-    /// Render scale for a viewer magnification (and display pixel density).
-    pub fn scale(self, zoom: f32, ppp: f32) -> f64 {
-        match self.factor() {
-            Some(n) => 1.0 / f64::from(n.clamp(1, 40)),
-            // As in After Effects, Auto renders the pixels the magnification needs: the coarsest
-            // whole factor that still gives every screen pixel a rendered one (Full above 50 %,
-            // Half down to 33.3 %, Third down to 25 %, Quarter below), never fewer (#417).
-            None => {
-                let n = (1.0 / (zoom * ppp) as f64 + 1e-3).floor();
-                if n >= 1.0 { 1.0 / n.min(4.0) } else { 1.0 }
-            }
-        }
-    }
-}
-
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct Comp {
-    pub width: u32,
-    pub height: u32,
-    pub pixel_aspect: f64,
-    pub frame_rate: FrameRate,
-    pub duration: Tick,
-    /// Start timecode/frame shown for time 0.
-    pub display_start: Tick,
-    pub background: [f32; 3],
-    pub work_area: (Tick, Tick),
-    /// Layer #1 first (top of the stack).
-    pub layers: Vec<Layer>,
-    #[serde(default)]
-    pub markers: Vec<Marker>,
-    pub shutter_angle: f64,
-    pub shutter_phase: f64,
-    /// Samples Per Frame: the minimum motion-blur samples (and the count for 3D layers).
-    pub motion_blur_samples: u32,
-    /// Adaptive Sample Limit (Composition Settings ▸ Advanced): the most samples a 2D layer gets
-    /// when it moves far within the shutter.
-    #[serde(default = "adaptive_limit_default")]
-    pub motion_blur_adaptive_limit: u32,
-    #[serde(default)]
-    pub renderer: Renderer,
-    /// Comp switches (timeline toolbar).
-    #[serde(default)]
-    pub hide_shy: bool,
-    #[serde(default = "yes")]
-    pub enable_motion_blur: bool,
-    #[serde(default = "yes")]
-    pub enable_frame_blending: bool,
-    #[serde(default)]
-    pub draft_3d: bool,
-    /// Composition Settings ▸ Advanced ▸ Preserve frame rate when nested or in render queue:
-    /// nested in another comp, or rendered at another rate, it shows only its own frames.
-    #[serde(default)]
-    pub preserve_frame_rate: bool,
-    /// Composition Settings ▸ Advanced ▸ Preserve resolution when nested: nested in a comp
-    /// previewed at a lower resolution, it still renders at full size.
-    #[serde(default)]
-    pub preserve_resolution: bool,
-    #[serde(default)]
-    pub poster_time: Tick,
-    /// Global Light for layer styles (Layer ▸ Layer Styles ▸ Blending Options).
-    #[serde(default)]
-    pub global_light: styles::GlobalLight,
-    /// Viewer guides (View ▸ Add Guide…), in comp pixels.
-    #[serde(default, skip_serializing_if = "Vec::is_empty")]
-    pub guides: Vec<Guide>,
-    /// Essential Graphics: the controls this comp exposes to instances and templates.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub essential: Option<essential::EssentialGraphics>,
-    /// The Composition panel's Resolution, saved with the project as in After Effects. It changes
-    /// what the viewer renders, not the comp's pixels ([`Comp::same_pixels`]), and stays out of
-    /// the undo history.
-    #[serde(default, skip_serializing_if = "Resolution::is_auto")]
-    pub resolution: Resolution,
-}
-
-/// A viewer guide line: vertical guides sit at an x position, horizontal ones at a y position.
-#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize)]
-pub struct Guide {
-    pub vertical: bool,
-    /// Comp pixels, or percent of the comp's width (vertical) / height (horizontal) when
-    /// [`Guide::percent`] is set.
-    pub position: f64,
-    /// A percentage guide (After Effects 26.5): `position` is a percent of the comp's size, so the
-    /// guide keeps its relative place when the comp is resized. Absent in older projects.
-    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
-    pub percent: bool,
-}
-
-impl Guide {
-    /// The comp's extent along this guide's axis, never zero.
-    fn extent(&self, width: u32, height: u32) -> f64 {
-        f64::from(if self.vertical { width } else { height }).max(1.0)
-    }
-
-    /// The guide's position in comp pixels for a comp of this size.
-    pub fn px(&self, width: u32, height: u32) -> f64 {
-        if self.percent { self.position / 100.0 * self.extent(width, height) } else { self.position }
-    }
-
-    /// Place the guide at `px` comp pixels, keeping its unit.
-    pub fn set_px(&mut self, px: f64, width: u32, height: u32) {
-        self.position = if self.percent { px / self.extent(width, height) * 100.0 } else { px };
-    }
-
-    /// Switch between pixels and percent without moving the guide on the comp.
-    pub fn set_percent(&mut self, percent: bool, width: u32, height: u32) {
-        let px = self.px(width, height);
-        self.percent = percent;
-        self.set_px(px, width, height);
-    }
-}
-
-fn yes() -> bool {
-    true
-}
-
-fn adaptive_limit_default() -> u32 {
-    128
-}
-
-impl Comp {
-    pub fn new(width: u32, height: u32, frame_rate: FrameRate, duration: Tick) -> Comp {
-        Comp {
-            width,
-            height,
-            pixel_aspect: 1.0,
-            frame_rate,
-            duration,
-            display_start: Tick::ZERO,
-            background: [0.0, 0.0, 0.0],
-            work_area: (Tick::ZERO, duration),
-            layers: vec![],
-            markers: vec![],
-            shutter_angle: 180.0,
-            shutter_phase: -90.0,
-            motion_blur_samples: 16,
-            motion_blur_adaptive_limit: 128,
-            renderer: Renderer::Classic3D,
-            hide_shy: false,
-            enable_motion_blur: true,
-            enable_frame_blending: true,
-            draft_3d: false,
-            preserve_frame_rate: false,
-            preserve_resolution: false,
-            poster_time: Tick::ZERO,
-            guides: vec![],
-            global_light: styles::GlobalLight::default(),
-            essential: None,
-            resolution: Resolution::Auto,
-        }
-    }
-    /// Whether the composition has a frame at its time `t`: nested, it shows nothing before it
-    /// starts or after it ends (a precomp layer trimmed or remapped past it).
-    pub fn covers(&self, t: Tick) -> bool {
-        t >= Tick::ZERO && t < self.duration
-    }
-    /// A new, empty composition with this one's settings (frame rate, pixel aspect, background,
-    /// motion blur, frame blending and the 3D renderer), as Pre-compose makes.
-    pub fn nested_like(&self, width: u32, height: u32, duration: Tick) -> Comp {
-        Comp {
-            pixel_aspect: self.pixel_aspect,
-            background: self.background,
-            shutter_angle: self.shutter_angle,
-            shutter_phase: self.shutter_phase,
-            motion_blur_samples: self.motion_blur_samples,
-            motion_blur_adaptive_limit: self.motion_blur_adaptive_limit,
-            renderer: self.renderer,
-            enable_motion_blur: self.enable_motion_blur,
-            enable_frame_blending: self.enable_frame_blending,
-            preserve_frame_rate: self.preserve_frame_rate,
-            preserve_resolution: self.preserve_resolution,
-            ..Comp::new(width, height, self.frame_rate, duration)
-        }
-    }
-    pub fn layer(&self, id: LayerId) -> Option<&Layer> {
-        self.layers.iter().find(|l| l.id == id)
-    }
-    pub fn layer_mut(&mut self, id: LayerId) -> Option<&mut Layer> {
-        self.layers.iter_mut().find(|l| l.id == id)
-    }
-    /// 1-based layer number (#) of a layer.
-    pub fn index_of(&self, id: LayerId) -> Option<usize> {
-        self.layers.iter().position(|l| l.id == id).map(|i| i + 1)
-    }
-    pub fn layer_by_name(&self, name: &str) -> Option<&Layer> {
-        self.layers.iter().find(|l| l.name == name)
-    }
-    pub fn frame_duration(&self) -> Tick {
-        self.frame_rate.frame_duration()
-    }
-    /// Any 3D layer present (camera/lights or a 3D switch).
-    pub fn has_3d(&self) -> bool {
-        self.layers.iter().any(|l| l.switches.three_d || matches!(l.source, LayerSource::Camera | LayerSource::Light { .. }))
-    }
-    /// The active camera at `t`: the topmost enabled camera layer active at that time.
-    pub fn active_camera(&self, t: Tick) -> Option<&Layer> {
-        self.layers.iter().find(|l| matches!(l.source, LayerSource::Camera) && l.switches.video && l.is_active_at(t))
-    }
-    /// Unique layer name with a numeric suffix (`Shape Layer 2`).
-    pub fn unique_layer_name(&self, base: &str) -> String {
-        if !self.layers.iter().any(|l| l.name == base) {
-            return base.to_string();
-        }
-        let stem = base.trim_end_matches(|c: char| c.is_ascii_digit()).trim_end();
-        (2..).map(|i| format!("{stem} {i}")).find(|n| !self.layers.iter().any(|l| &l.name == n)).unwrap_or_default()
-    }
-}
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum LightKind {
-    Parallel,
-    Spot,
-    #[default]
-    Point,
-    Ambient,
-    Environment,
-}
-
-impl LightKind {
-    pub const ALL: [LightKind; 5] = [LightKind::Parallel, LightKind::Spot, LightKind::Point, LightKind::Ambient, LightKind::Environment];
-    pub fn label(self) -> &'static str {
-        match self {
-            LightKind::Parallel => "Parallel",
-            LightKind::Spot => "Spot",
-            LightKind::Point => "Point",
-            LightKind::Ambient => "Ambient",
-            LightKind::Environment => "Environment",
-        }
-    }
-}
-
-/// A parametric 3D primitive (Layer ▸ New ▸ Cube/Sphere/Plane/Torus/Cone/Cylinder).
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
-pub enum PrimitiveKind {
-    #[default]
-    Cube,
-    Sphere,
-    Plane,
-    Torus,
-    Cone,
-    Cylinder,
-}
-
-impl PrimitiveKind {
-    pub const ALL: [PrimitiveKind; 6] =
-        [PrimitiveKind::Cube, PrimitiveKind::Sphere, PrimitiveKind::Plane, PrimitiveKind::Torus, PrimitiveKind::Cone, PrimitiveKind::Cylinder];
-    pub fn label(self) -> &'static str {
-        match self {
-            PrimitiveKind::Cube => "Cube",
-            PrimitiveKind::Sphere => "Sphere",
-            PrimitiveKind::Plane => "Plane",
-            PrimitiveKind::Torus => "Torus",
-            PrimitiveKind::Cone => "Cone",
-            PrimitiveKind::Cylinder => "Cylinder",
-        }
-    }
-    pub fn parse(s: &str) -> Option<PrimitiveKind> {
-        PrimitiveKind::ALL.into_iter().find(|k| k.label().eq_ignore_ascii_case(s.trim()))
-    }
-}
-
-/// What a layer shows.
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-#[serde(tag = "type")]
-pub enum LayerSource {
-    /// Footage item (video, still, sequence, audio).
-    Footage {
-        item: ItemId,
-    },
-    /// Nested composition (precomp).
-    Comp {
-        item: ItemId,
-    },
-    /// Solid item (solids also back adjustment layers).
-    Solid {
-        item: ItemId,
-    },
-    Text,
-    Shape,
-    Null,
-    Camera,
-    Light {
-        kind: LightKind,
-    },
-    /// An imported 3D model (a footage item of kind [`FootageKind::Model`]; Advanced 3D).
-    Model {
-        item: ItemId,
-    },
-    /// A parametric 3D primitive (Advanced 3D).
-    Primitive {
-        kind: PrimitiveKind,
-    },
-}
-
-impl LayerSource {
-    pub fn item(&self) -> Option<ItemId> {
-        match self {
-            LayerSource::Footage { item } | LayerSource::Comp { item } | LayerSource::Solid { item } | LayerSource::Model { item } => Some(*item),
-            _ => None,
-        }
-    }
-    pub fn type_name(&self) -> &'static str {
-        match self {
-            LayerSource::Footage { .. } => "Footage",
-            LayerSource::Comp { .. } => "Composition",
-            LayerSource::Solid { .. } => "Solid",
-            LayerSource::Text => "Text",
-            LayerSource::Shape => "Shape",
-            LayerSource::Null => "Null",
-            LayerSource::Camera => "Camera",
-            LayerSource::Light { .. } => "Light",
-            LayerSource::Model { .. } => "3D Model",
-            LayerSource::Primitive { .. } => "3D Primitive",
-        }
-    }
-    /// Layers with pixels (cameras, lights and nulls have none).
-    pub fn is_av(&self) -> bool {
-        !matches!(self, LayerSource::Camera | LayerSource::Light { .. } | LayerSource::Null)
-    }
-    /// A 3D model or primitive layer (meshes; drawn by the Advanced 3D renderer).
-    pub fn is_model(&self) -> bool {
-        matches!(self, LayerSource::Model { .. } | LayerSource::Primitive { .. })
-    }
-}
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum Quality {
-    #[default]
-    Best,
-    Draft,
-    Wireframe,
-}
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum Sampling {
-    #[default]
-    Bilinear,
-    Bicubic,
-}
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum FrameBlend {
-    #[default]
-    Off,
-    FrameMix,
-    PixelMotion,
-}
-
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct Switches {
-    pub video: bool,
-    pub audio: bool,
-    pub solo: bool,
-    pub locked: bool,
-    pub shy: bool,
-    /// Collapse transformations (precomps) / continuously rasterize (vector layers).
-    pub collapse: bool,
-    pub quality: Quality,
-    pub sampling: Sampling,
-    pub effects: bool,
-    pub frame_blend: FrameBlend,
-    pub motion_blur: bool,
-    pub adjustment: bool,
-    pub three_d: bool,
-    pub guide: bool,
-}
-
-impl Default for Switches {
-    fn default() -> Self {
-        Switches {
-            video: true,
-            audio: true,
-            solo: false,
-            locked: false,
-            shy: false,
-            collapse: false,
-            quality: Quality::Best,
-            sampling: Sampling::Bilinear,
-            effects: true,
-            frame_blend: FrameBlend::Off,
-            motion_blur: false,
-            adjustment: false,
-            three_d: false,
-            guide: false,
-        }
-    }
-}
-
-// What a frame's pixels depend on. Caches key on it: the Audio, Lock and Shy switches and Hide
-// Shy Layers don't change pixels, so toggling them keeps cached frames (#103).
-
-impl Switches {
-    /// These switches with Audio, Lock and Shy at their defaults.
-    pub fn pixels(&self) -> Switches {
-        Switches { audio: true, locked: false, shy: false, ..self.clone() }
-    }
-}
-
-impl Layer {
-    /// Draws the same pixels as `o`: equal but for the Audio, Lock and Shy switches.
-    pub fn same_pixels(&self, o: &Layer) -> bool {
-        // Every field (no `..`: a new field must be considered here); the property tree last.
-        let Layer {
-            id,
-            name,
-            source,
-            label,
-            comment,
-            start_time,
-            in_point,
-            out_point,
-            stretch,
-            switches,
-            blend_mode,
-            preserve_transparency,
-            track_matte,
-            parent,
-            markers,
-            markers_locked,
-            auto_orient,
-            environment,
-            environment_background,
-            props,
-        } = self;
-        *id == o.id
-            && *name == o.name
-            && *source == o.source
-            && *label == o.label
-            && *comment == o.comment
-            && *start_time == o.start_time
-            && *in_point == o.in_point
-            && *out_point == o.out_point
-            && *stretch == o.stretch
-            && switches.pixels() == o.switches.pixels()
-            && *blend_mode == o.blend_mode
-            && *preserve_transparency == o.preserve_transparency
-            && *track_matte == o.track_matte
-            && *parent == o.parent
-            && *markers == o.markers
-            && *markers_locked == o.markers_locked
-            && *auto_orient == o.auto_orient
-            && *environment == o.environment
-            && *environment_background == o.environment_background
-            && *props == o.props
-    }
-}
-
-impl Comp {
-    /// Draws the same pixels as `o`: equal but for its layers' Audio, Lock and Shy switches, Hide
-    /// Shy Layers and the viewer's Resolution.
-    pub fn same_pixels(&self, o: &Comp) -> bool {
-        self.same_settings(o) && self.layers.len() == o.layers.len() && self.layers.iter().zip(&o.layers).all(|(a, b)| a.same_pixels(b))
-    }
-
-    /// [`Self::same_pixels`] but for the layers.
-    fn same_settings(&self, o: &Comp) -> bool {
-        // Every field (no `..`: a new field must be considered here).
-        let Comp {
-            width,
-            height,
-            pixel_aspect,
-            frame_rate,
-            duration,
-            display_start,
-            background,
-            work_area,
-            layers: _,
-            markers,
-            shutter_angle,
-            shutter_phase,
-            motion_blur_samples,
-            motion_blur_adaptive_limit,
-            renderer,
-            hide_shy: _,
-            enable_motion_blur,
-            enable_frame_blending,
-            draft_3d,
-            preserve_frame_rate,
-            preserve_resolution,
-            poster_time,
-            global_light,
-            guides,
-            essential,
-            resolution: _,
-        } = self;
-        *width == o.width
-            && *height == o.height
-            && *pixel_aspect == o.pixel_aspect
-            && *frame_rate == o.frame_rate
-            && *duration == o.duration
-            && *display_start == o.display_start
-            && *background == o.background
-            && *work_area == o.work_area
-            && *markers == o.markers
-            && *shutter_angle == o.shutter_angle
-            && *shutter_phase == o.shutter_phase
-            && *motion_blur_samples == o.motion_blur_samples
-            && *motion_blur_adaptive_limit == o.motion_blur_adaptive_limit
-            && *renderer == o.renderer
-            && *enable_motion_blur == o.enable_motion_blur
-            && *enable_frame_blending == o.enable_frame_blending
-            && *draft_3d == o.draft_3d
-            && *preserve_frame_rate == o.preserve_frame_rate
-            && *preserve_resolution == o.preserve_resolution
-            && *poster_time == o.poster_time
-            && *global_light == o.global_light
-            && *guides == o.guides
-            && *essential == o.essential
-    }
-
-    /// The comp-time span (`in_point..out_point` of every layer changed, added or removed,
-    /// widened by the shutter) outside which `self` draws the same pixels as `o`, so cached
-    /// frames there stay valid (#1641). `None` when the edit can reach any frame: a comp setting,
-    /// a layer reorder, Solo turning on or off, an expression (it reads anything), or a changed
-    /// layer another layer parents to, mattes with or picks in an effect.
-    pub fn changed_span(&self, o: &Comp) -> Option<(Tick, Tick)> {
-        fn reads(g: &PropGroup, changed: &[LayerId]) -> bool {
-            g.children.iter().any(|c| match c {
-                Node::Prop(p) => {
-                    p.expr.is_some()
-                        || std::iter::once(&p.value)
-                            .chain(p.keys.iter().map(|k| &k.value))
-                            .any(|v| matches!(v, Value::Layer(Some(id)) if changed.contains(&LayerId(*id))))
-                }
-                Node::Group(g) => reads(g, changed),
-            })
-        }
-        // Solo hides every other layer at every frame.
-        if !self.same_settings(o) || self.any_solo() != o.any_solo() {
-            return None;
-        }
-        let common = |a: &Comp, b: &Comp| a.layers.iter().map(|l| l.id).filter(|id| b.layer(*id).is_some()).collect::<Vec<_>>();
-        if common(self, o) != common(o, self) {
-            return None;
-        }
-        let mut changed = Vec::new();
-        let mut span: Option<(Tick, Tick)> = None;
-        // Each changed layer comes up from both sides: its old and its new span.
-        for (l, other) in self.layers.iter().map(|l| (l, o.layer(l.id))).chain(o.layers.iter().map(|l| (l, self.layer(l.id)))) {
-            if other.is_some_and(|b| l.same_pixels(b)) {
-                continue;
-            }
-            changed.push(l.id);
-            let (s, e) = (l.in_point.min(l.out_point), l.in_point.max(l.out_point));
-            span = Some(span.map_or((s, e), |(a, b)| (a.min(s), b.max(e))));
-        }
-        let reaches = |l: &Layer| {
-            l.parent.is_some_and(|p| changed.contains(&p)) || l.track_matte.as_ref().is_some_and(|m| changed.contains(&m.layer)) || reads(&l.props, &changed)
-        };
-        if self.layers.iter().chain(&o.layers).any(reaches) {
-            return None;
-        }
-        // A frame at `t` samples cameras, lights and transforms over its shutter,
-        // `t + (phase + angle * 0..=1) / 360` frames, and draws the layers active at `t` itself.
-        let (a, p) = (self.shutter_angle / 360.0, self.shutter_phase / 360.0);
-        let fd = self.frame_duration().seconds();
-        let (before, after) = (Tick::from_seconds_f64(p.max(p + a).max(0.0) * fd), Tick::from_seconds_f64(-p.min(p + a).min(0.0) * fd));
-        span.map(|(s, e)| (s - before, e + after))
-    }
-
-    /// Some layer is soloed: only the soloed layers draw.
-    pub fn any_solo(&self) -> bool {
-        self.layers.iter().any(|l| l.switches.solo && l.source.is_av())
-    }
-
-    /// Draws the same pixels as `o` once plain markers are ignored: they change no pixels. Protected
-    /// time markers with a duration set the timing (Responsive Design), so those still count.
-    pub fn same_pixels_ignoring_markers(&self, o: &Comp) -> bool {
-        let protected =
-            |m: &[Marker]| -> Vec<(Tick, Tick)> { m.iter().filter(|m| m.protected && m.duration > Tick::ZERO).map(|m| (m.time, m.duration)).collect() };
-        if protected(&self.markers) != protected(&o.markers) {
-            return false;
-        }
-        let mut c = self.clone();
-        c.markers = o.markers.clone();
-        for (a, b) in c.layers.iter_mut().zip(&o.layers) {
-            a.markers = b.markers.clone();
-            a.markers_locked = b.markers_locked;
-        }
-        c.same_pixels(o)
-    }
-
-    /// The comp with those switches and the Resolution at their defaults (borrowed when they
-    /// already are), for keys that hash the whole comp.
-    pub fn pixel_form(&self) -> std::borrow::Cow<'_, Comp> {
-        if !self.hide_shy && self.resolution.is_auto() && self.layers.iter().all(|l| l.switches == l.switches.pixels()) {
-            return std::borrow::Cow::Borrowed(self);
-        }
-        let mut c = self.clone();
-        c.hide_shy = false;
-        c.resolution = Resolution::Auto;
-        for l in &mut c.layers {
-            l.switches = l.switches.pixels();
-        }
-        std::borrow::Cow::Owned(c)
-    }
-}
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum MatteKind {
-    #[default]
-    Alpha,
-    AlphaInverted,
-    Luma,
-    LumaInverted,
-}
-
-impl MatteKind {
-    pub const ALL: [MatteKind; 4] = [MatteKind::Alpha, MatteKind::AlphaInverted, MatteKind::Luma, MatteKind::LumaInverted];
-    pub fn label(self) -> &'static str {
-        match self {
-            MatteKind::Alpha => "Alpha Matte",
-            MatteKind::AlphaInverted => "Alpha Inverted Matte",
-            MatteKind::Luma => "Luma Matte",
-            MatteKind::LumaInverted => "Luma Inverted Matte",
-        }
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
-pub struct TrackMatte {
-    pub layer: LayerId,
-    pub kind: MatteKind,
-}
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum AutoOrient {
-    #[default]
-    Off,
-    AlongPath,
-    TowardsCamera,
-    TowardsPointOfInterest,
-}
-
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct Layer {
-    pub id: LayerId,
-    pub name: String,
-    pub source: LayerSource,
-    pub label: Label,
-    #[serde(default)]
-    pub comment: String,
-    /// Comp time where the layer's time 0 sits.
-    pub start_time: Tick,
-    /// Visible span in comp time.
-    pub in_point: Tick,
-    pub out_point: Tick,
-    /// Time stretch in percent (100 = normal, negative = reversed).
-    pub stretch: f64,
-    pub switches: Switches,
-    pub blend_mode: BlendMode,
-    #[serde(default)]
-    pub preserve_transparency: bool,
-    #[serde(default)]
-    pub track_matte: Option<TrackMatte>,
-    #[serde(default)]
-    pub parent: Option<LayerId>,
-    #[serde(default)]
-    pub markers: Vec<Marker>,
-    /// Layer ▸ Markers ▸ Lock Markers.
-    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
-    pub markers_locked: bool,
-    #[serde(default)]
-    pub auto_orient: AutoOrient,
-    /// Layer ▸ Environment Layer: the layer is the environment (image-based light and
-    /// reflections) of Advanced 3D comps instead of being drawn.
-    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
-    pub environment: bool,
-    /// Layer ▸ Light ▸ Create Environment Light Background Layer: the layer's (equirectangular)
-    /// image is drawn as the 3D scene's backdrop, seen through the camera, instead of as a card.
-    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
-    pub environment_background: bool,
-    /// The property tree (Masks, Effects, Transform, Text, Contents, Camera/Light options…).
-    pub props: PropGroup,
-}
-
-impl Layer {
-    pub fn is_active_at(&self, t: Tick) -> bool {
-        t >= self.in_point && t < self.out_point
-    }
-    /// Layer time for a comp time (stretch-aware).
-    pub fn layer_time(&self, comp_t: Tick) -> Tick {
-        let d = comp_t - self.start_time;
-        if (self.stretch - 100.0).abs() < 1e-9 { d } else { Tick((d.0 as f64 * 100.0 / self.stretch) as i64) }
-    }
-    /// Comp time for a layer time.
-    pub fn comp_time(&self, layer_t: Tick) -> Tick {
-        if (self.stretch - 100.0).abs() < 1e-9 { self.start_time + layer_t } else { self.start_time + Tick((layer_t.0 as f64 * self.stretch / 100.0) as i64) }
-    }
-    pub fn transform(&self) -> Option<&PropGroup> {
-        self.props.sub("transform")
-    }
-    pub fn transform_mut(&mut self) -> Option<&mut PropGroup> {
-        self.props.sub_mut("transform")
-    }
-    pub fn effects(&self) -> Option<&PropGroup> {
-        self.props.sub("effects")
-    }
-    pub fn masks(&self) -> Option<&PropGroup> {
-        self.props.sub("masks")
-    }
-    pub fn is_camera(&self) -> bool {
-        matches!(self.source, LayerSource::Camera)
-    }
-    pub fn is_light(&self) -> bool {
-        matches!(self.source, LayerSource::Light { .. })
-    }
-    /// The layer participates in 3D (3D switch, or cameras/lights which are always 3D).
-    pub fn is_3d(&self) -> bool {
-        self.switches.three_d || self.is_camera() || self.is_light()
-    }
-    pub fn has_video(&self) -> bool {
-        self.source.is_av() && self.switches.video
-    }
-}
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum FootageKind {
-    #[default]
-    Video,
-    Still,
-    Sequence,
-    Audio,
-    /// A 3D model (glTF 2.0 / OBJ), placed as a model layer.
-    Model,
-    /// A data file (JSON, CSV, TSV) for data-driven animation: read by expressions through
-    /// `footage(name).sourceData` / `sourceText` / `dataValue`; it has no pixels.
-    Data,
-}
-
-/// Interpret Footage ▸ Fields and Pulldown ▸ Separate Fields.
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
-pub enum FieldOrder {
-    /// Progressive frames.
-    #[default]
-    Off,
-    /// Interlaced, upper (odd) field first: each field becomes a frame at twice the rate.
-    UpperFirst,
-    LowerFirst,
-}
-
-impl FieldOrder {
-    pub fn label(self) -> &'static str {
-        match self {
-            FieldOrder::Off => "Off",
-            FieldOrder::UpperFirst => "Upper Field First",
-            FieldOrder::LowerFirst => "Lower Field First",
-        }
-    }
-    pub fn parse(s: &str) -> Option<FieldOrder> {
-        match s.to_ascii_lowercase().replace([' ', '_', '-'], "").as_str() {
-            "off" | "none" | "progressive" => Some(FieldOrder::Off),
-            "upper" | "upperfirst" | "upperfieldfirst" => Some(FieldOrder::UpperFirst),
-            "lower" | "lowerfirst" | "lowerfieldfirst" => Some(FieldOrder::LowerFirst),
-            _ => None,
-        }
-    }
-}
-
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub enum AlphaMode {
-    #[default]
-    Straight,
-    Premultiplied,
-    Ignore,
-}
-
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct Footage {
-    pub path: String,
-    pub kind: FootageKind,
-    pub width: u32,
-    pub height: u32,
-    pub pixel_aspect: f64,
-    pub frame_rate: FrameRate,
-    /// Native rate before "Conform to frame rate".
-    #[serde(default)]
-    pub native_rate: Option<FrameRate>,
-    pub duration: Tick,
-    pub has_video: bool,
-    pub has_audio: bool,
-    pub alpha: AlphaMode,
-    #[serde(default)]
-    pub premul_color: [f32; 3],
-    #[serde(default = "one")]
-    pub loop_count: u32,
-    #[serde(default)]
-    pub codec: String,
-    #[serde(default)]
-    pub missing: bool,
-    /// Image sequence files (when kind = Sequence).
-    #[serde(default, skip_serializing_if = "Vec::is_empty")]
-    pub sequence: Vec<String>,
-    /// Colour profile (from the file's metadata, or Interpret Footage). `None` = sRGB.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub color_profile: Option<ColorSpace>,
-    /// One layer of a layered file (Photoshop) instead of its merged image.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub layer: Option<SourceLayer>,
-    /// Interpret Footage ▸ Fields and Pulldown ▸ Separate Fields.
-    #[serde(default, skip_serializing_if = "is_default")]
-    pub fields: FieldOrder,
-    /// Interpret Footage ▸ Alpha ▸ Invert Alpha.
-    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
-    pub invert_alpha: bool,
-    /// Interpret Footage ▸ Color ▸ Interpret As Linear Light: the file's values are linear.
-    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
-    pub linear_light: bool,
-    /// Interpret Footage ▸ Color ▸ Preserve RGB: the file's values enter the composition
-    /// unconverted. Float footage (OpenEXR, float TIFF) is not sRGB-encoded on decode, and the
-    /// colour profile, Interpret As Linear Light and the working space don't apply.
-    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
-    pub preserve_rgb: bool,
-    /// Data footage ([`FootageKind::Data`]): the file's text (JSON, CSV or TSV), kept in the
-    /// project so expressions read it everywhere (and on the web).
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub data: Option<String>,
-    /// PDF / Illustrator footage: the page shown (0-based; File ▸ Import ▸ Page).
-    #[serde(default, skip_serializing_if = "is_default")]
-    pub page: u32,
-    /// Image sequences imported with Force Alphabetical Order: the files play one after another
-    /// and their numbering doesn't count (otherwise a gap in it shows a placeholder, as in After
-    /// Effects; [`sequence`]).
-    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
-    pub alphabetical: bool,
-    /// Interpret Footage ▸ Start Timecode ▸ Override Start: the frame (at the footage's frame
-    /// rate) its timecode shows at its first frame. `None` = Use Source File Timecode (0: file
-    /// timecode isn't read). It only relabels source time, as in After Effects.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub start_timecode: Option<i64>,
-}
-
-fn is_default<T: Default + PartialEq>(v: &T) -> bool {
-    *v == T::default()
-}
-
-impl Default for Footage {
-    fn default() -> Self {
-        Footage {
-            path: String::new(),
-            kind: FootageKind::Still,
-            width: 0,
-            height: 0,
-            pixel_aspect: 1.0,
-            frame_rate: FrameRate::FPS_30,
-            native_rate: None,
-            duration: Tick::ZERO,
-            has_video: false,
-            has_audio: false,
-            alpha: AlphaMode::Straight,
-            premul_color: [0.0; 3],
-            loop_count: 1,
-            codec: String::new(),
-            missing: false,
-            sequence: vec![],
-            color_profile: None,
-            fields: FieldOrder::Off,
-            invert_alpha: false,
-            linear_light: false,
-            preserve_rgb: false,
-            data: None,
-            layer: None,
-            page: 0,
-            alphabetical: false,
-            start_timecode: None,
-        }
-    }
-}
-
-impl Footage {
-    /// Interpret As Linear Light applies (Preserve RGB passes the file's values through).
-    pub fn linear_light_applies(&self) -> bool {
-        self.linear_light && !self.preserve_rgb
-    }
-
-    /// How long the footage plays: its duration times Interpret Footage ▸ Loop.
-    pub fn looped_duration(&self) -> Tick {
-        Tick(self.duration.0.saturating_mul(self.loop_count.max(1) as i64))
-    }
-
-    /// Source time as the footage's timecode: its frame `frame` from Start Timecode
-    /// (`0:00:41:20`), as the Footage panel shows it.
-    pub fn timecode(&self, frame: i64) -> String {
-        effectcraft_time::format_timecode_ae(frame.saturating_add(self.start_timecode.unwrap_or(0)), self.frame_rate, false)
-    }
-
-    /// The data format of data footage: `json`, `csv` or `tsv` (from the file extension).
-    pub fn data_format(&self) -> Option<&'static str> {
-        if self.kind != FootageKind::Data {
-            return None;
-        }
-        let ext = std::path::Path::new(&self.path).extension().and_then(std::ffi::OsStr::to_str).unwrap_or("").to_ascii_lowercase();
-        Some(match ext.as_str() {
-            "csv" => "csv",
-            "tsv" | "tab" => "tsv",
-            _ => "json",
-        })
-    }
-}
-
-/// A proxy: a stand-in file used instead of a footage item or composition (File ▸ Set Proxy /
-/// Create Proxy), when its Use Proxy switch is on and the render's Proxy Use allows it.
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct Proxy {
-    /// The proxy's footage (path, size, rate…; File ▸ Interpret Footage ▸ Proxy edits it).
-    pub footage: Footage,
-    /// Use Proxy (the Project panel's proxy indicator: filled = in use, hollow = set but off).
-    #[serde(default = "yes")]
-    pub enabled: bool,
-}
-
-/// A layer of a layered still (a Photoshop document, or a PDF / Illustrator / EPS file) used as
-/// footage (File ▸ Import ▸ Composition / Composition – Retain Layer Sizes, or Choose Layer).
-#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub struct SourceLayer {
-    /// Layer record index in the file (bottom of the stack = 0).
-    pub index: u32,
-    pub name: String,
-    /// The footage is the layer's own bounds (Retain Layer Sizes) rather than the document size.
-    #[serde(default)]
-    pub layer_size: bool,
-    /// A Photoshop smart object: the unique id of its embedded file (linked layer data), which
-    /// is the footage instead of the layer's pixels.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub embedded: Option<String>,
-    /// A smart object with a perspective quad or a warp: the footage is its embedded file baked
-    /// as placed (warped and pinned to its corners) over the placed bounds in document space.
-    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
-    pub placed: bool,
-}
-
-fn one() -> u32 {
-    1
-}
-
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct Solid {
-    pub color: [f32; 3],
-    pub width: u32,
-    pub height: u32,
-    pub pixel_aspect: f64,
-}
-
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-#[serde(tag = "type")]
-#[allow(clippy::large_enum_variant)]
-pub enum ItemKind {
-    Folder,
-    Comp(Arc<Comp>),
-    Footage(Footage),
-    Solid(Solid),
-}
-
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct Item {
-    pub id: ItemId,
-    pub name: String,
-    pub label: Label,
-    #[serde(default)]
-    pub comment: String,
-    /// Containing folder (None = project root).
-    #[serde(default)]
-    pub parent: Option<ItemId>,
-    pub kind: ItemKind,
-    /// The item's proxy (footage and compositions).
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub proxy: Option<Box<Proxy>>,
-}
-
-impl Item {
-    pub fn type_name(&self) -> &'static str {
-        match &self.kind {
-            ItemKind::Folder => "Folder",
-            ItemKind::Comp(_) => "Composition",
-            ItemKind::Footage(f) => match f.kind {
-                FootageKind::Video => "Video",
-                FootageKind::Still => "Image",
-                FootageKind::Sequence => "Image Sequence",
-                FootageKind::Audio => "Audio",
-                FootageKind::Model => "3D Model",
-                FootageKind::Data => "Data",
-            },
-            ItemKind::Solid(_) => "Solid",
-        }
-    }
-    pub fn as_comp(&self) -> Option<&Comp> {
-        if let ItemKind::Comp(c) = &self.kind { Some(c) } else { None }
-    }
-    pub fn is_folder(&self) -> bool {
-        matches!(self.kind, ItemKind::Folder)
-    }
-    /// (width, height) for visual items.
-    pub fn dimensions(&self) -> Option<(u32, u32)> {
-        match &self.kind {
-            ItemKind::Comp(c) => Some((c.width, c.height)),
-            ItemKind::Footage(f) if f.has_video => Some((f.width, f.height)),
-            ItemKind::Solid(s) => Some((s.width, s.height)),
-            _ => None,
-        }
-    }
-    pub fn duration(&self) -> Option<Tick> {
-        match &self.kind {
-            ItemKind::Comp(c) => Some(c.duration),
-            ItemKind::Footage(f) if f.kind != FootageKind::Still => Some(f.looped_duration()),
-            _ => None,
-        }
-    }
-    pub fn frame_rate(&self) -> Option<FrameRate> {
-        match &self.kind {
-            ItemKind::Comp(c) => Some(c.frame_rate),
-            ItemKind::Footage(f) if f.kind == FootageKind::Video || f.kind == FootageKind::Sequence => Some(f.frame_rate),
-            _ => None,
-        }
-    }
-}
+mod comp;
+mod footage;
+mod item;
+mod layer;
+mod settings;
+
+pub use comp::{Comp, Guide, Renderer, Resolution};
+pub use footage::{AlphaMode, FieldOrder, Footage, FootageKind, Proxy, Solid, SourceLayer};
+pub use item::{Item, ItemId, ItemKind, LayerId};
+pub use layer::{AutoOrient, FrameBlend, Layer, LayerSource, LightKind, MatteKind, PrimitiveKind, Quality, Sampling, Switches, TrackMatte};
+pub use settings::{
+    APP_VERSION, BitDepth, ColorEngine, CuePoint, HdrMode, Marker, ProjectError, ProjectSettings, SCHEMA_EFFECT_SPACE, SCHEMA_VERSION, SavedView,
+    TimeDisplayStyle, is_newer_version, saved_by, saved_view,
+};
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
 pub struct Project {
@@ -1434,229 +61,5 @@ pub struct Project {
     pub render_prefs: render_queue::RenderQueuePrefs,
 }
 
-impl Default for Project {
-    fn default() -> Self {
-        Project {
-            schema: SCHEMA_VERSION,
-            settings: ProjectSettings::default(),
-            items: BTreeMap::new(),
-            next_id: 1,
-            render_queue: Vec::new(),
-            render_templates: Default::default(),
-            render_prefs: Default::default(),
-        }
-    }
-}
-
-impl Project {
-    /// Allocate an id (items, layers and property uids share one counter).
-    pub fn alloc(&mut self) -> u64 {
-        let id = self.next_id;
-        self.next_id += 1;
-        id
-    }
-    pub fn item(&self, id: ItemId) -> Option<&Item> {
-        self.items.get(&id)
-    }
-    pub fn item_mut(&mut self, id: ItemId) -> Option<&mut Item> {
-        self.items.get_mut(&id)
-    }
-    pub fn comp(&self, id: ItemId) -> Option<&Comp> {
-        self.items.get(&id)?.as_comp()
-    }
-    /// A shared handle on a comp: a snapshot that costs a reference count, not a deep copy of
-    /// its layers (frontends hold one across a frame instead of cloning the comp).
-    pub fn comp_arc(&self, id: ItemId) -> Option<Arc<Comp>> {
-        match &self.items.get(&id)?.kind {
-            ItemKind::Comp(c) => Some(c.clone()),
-            _ => None,
-        }
-    }
-    /// Mutable comp (copy-on-write).
-    pub fn comp_mut(&mut self, id: ItemId) -> Option<&mut Comp> {
-        match &mut self.items.get_mut(&id)?.kind {
-            ItemKind::Comp(c) => Some(Arc::make_mut(c)),
-            _ => None,
-        }
-    }
-    /// Adds an item; its size, frame rate and the like are brought within [`limits`] first.
-    pub fn add_item(&mut self, name: &str, label: Label, parent: Option<ItemId>, mut kind: ItemKind) -> ItemId {
-        limits::repair_kind(name, &mut kind, &mut vec![]);
-        let id = ItemId(self.alloc());
-        self.items.insert(id, Item { id, name: name.into(), label, comment: String::new(), parent, kind, proxy: None });
-        id
-    }
-    /// Children of a folder (None = root), folders first then by name.
-    pub fn children(&self, folder: Option<ItemId>) -> Vec<&Item> {
-        let mut v: Vec<&Item> = self.items.values().filter(|i| i.parent == folder).collect();
-        v.sort_by(|a, b| b.is_folder().cmp(&a.is_folder()).then_with(|| a.name.to_lowercase().cmp(&b.name.to_lowercase())));
-        v
-    }
-    pub fn comps(&self) -> impl Iterator<Item = (&ItemId, &Comp)> {
-        self.items.iter().filter_map(|(id, i)| i.as_comp().map(|c| (id, c)))
-    }
-    pub fn find_by_name(&self, name: &str) -> Option<&Item> {
-        self.items.values().find(|i| i.name == name)
-    }
-    /// A numbered name for a copy of `base` that no project item has (Edit ▸ Duplicate): its
-    /// trailing number is dropped and the lowest free one from 2 is added (`Comp 1` → `Comp 2`,
-    /// `Name` → `Name 2`, then `Name 3`). Items for which `ignore` holds don't count.
-    pub fn numbered_item_name(&self, base: &str, ignore: impl Fn(&Item) -> bool) -> String {
-        let stem = base.trim_end_matches(|c: char| c.is_ascii_digit()).trim_end();
-        let taken = |n: &str| self.items.values().any(|i| i.name == n && !ignore(i));
-        (2u64..).map(|k| format!("{stem} {k}")).find(|n| !taken(n)).unwrap_or_default()
-    }
-    /// `base` when no project item has that name, else the next free numbered name as
-    /// [`Project::numbered_item_name`] gives it. Items for which `ignore` holds don't count.
-    pub fn unique_item_name(&self, base: &str, ignore: impl Fn(&Item) -> bool) -> String {
-        if self.items.values().any(|i| i.name == base && !ignore(i)) { self.numbered_item_name(base, ignore) } else { base.to_string() }
-    }
-    pub fn folder_named(&self, name: &str) -> Option<ItemId> {
-        self.items.values().find(|i| i.is_folder() && i.name == name).map(|i| i.id)
-    }
-    /// Find the comp that contains `layer`.
-    pub fn comp_of_layer(&self, layer: LayerId) -> Option<ItemId> {
-        self.comps().find(|(_, c)| c.layer(layer).is_some()).map(|(id, _)| *id)
-    }
-    /// The compositions whose layers use `item` as their source (footage, solid, 3D model or
-    /// precomp), each with how many of its layers do, ordered by comp name then id. Only direct
-    /// layers count, as in After Effects' Project panel ("used 3 times"): a solid inside a precomp
-    /// is used by the precomp, not by the comps that nest it. The total is the sum of the counts.
-    pub fn item_users(&self, item: ItemId) -> Vec<(ItemId, usize)> {
-        let mut users: Vec<(ItemId, String, usize)> = self
-            .items
-            .iter()
-            .filter_map(|(id, it)| {
-                let comp = it.as_comp()?;
-                let n = comp.layers.iter().filter(|l| l.source.item() == Some(item)).count();
-                (n > 0).then(|| (*id, it.name.to_lowercase(), n))
-            })
-            .collect();
-        users.sort_by(|a, b| a.1.cmp(&b.1).then(a.0.cmp(&b.0)));
-        users.into_iter().map(|(id, _, n)| (id, n)).collect()
-    }
-    /// Whether comp `inner` is (transitively) nested inside comp `outer` (to prevent cycles).
-    pub fn comp_contains(&self, outer: ItemId, inner: ItemId) -> bool {
-        // A walk with a stack and a visited set rather than recursion (#1237): a damaged project
-        // may hold a precomp cycle that doesn't pass `inner` (recursion never ended), a long
-        // chain must not use up the call stack, and comps shared by many paths are visited once
-        // (recursion re-walked them for every path).
-        if outer == inner {
-            return true;
-        }
-        let mut seen = std::collections::HashSet::new();
-        let mut stack = vec![outer];
-        while let Some(id) = stack.pop() {
-            if !seen.insert(id) {
-                continue;
-            }
-            let Some(c) = self.comp(id) else { continue };
-            for l in &c.layers {
-                if let LayerSource::Comp { item } = l.source {
-                    if item == inner {
-                        return true;
-                    }
-                    if !seen.contains(&item) {
-                        stack.push(item);
-                    }
-                }
-            }
-        }
-        false
-    }
-    /// Make sure `next_id` exceeds every id in the project (after loading or merging).
-    pub fn fix_next_id(&mut self) {
-        let mut m = self.next_id;
-        for (id, it) in &self.items {
-            // Saturating: a damaged file's ids must not overflow (the import then refuses it).
-            m = m.max(id.0.saturating_add(1));
-            if let ItemKind::Comp(c) = &it.kind {
-                for l in &c.layers {
-                    m = m.max(l.id.0.saturating_add(1)).max(l.props.max_uid().saturating_add(1));
-                }
-            }
-        }
-        self.next_id = m;
-    }
-    /// Whether `other` holds the same content. An allocated id counts (an edit may hand it out
-    /// beyond the project, so it must stay taken). Shared compositions compare by pointer first,
-    /// so after a copy-on-write edit only the comps it touched are compared field by field.
-    pub fn same_content(&self, other: &Project) -> bool {
-        let item_eq = |a: &Item, b: &Item| {
-            let kind = match (&a.kind, &b.kind) {
-                (ItemKind::Comp(x), ItemKind::Comp(y)) => Arc::ptr_eq(x, y) || x == y,
-                (x, y) => x == y,
-            };
-            kind && a.id == b.id && a.name == b.name && a.label == b.label && a.comment == b.comment && a.parent == b.parent && a.proxy == b.proxy
-        };
-        self.schema == other.schema
-            && self.next_id == other.next_id
-            && self.settings == other.settings
-            && self.items.len() == other.items.len()
-            && self.items.iter().zip(&other.items).all(|((ka, a), (kb, b))| ka == kb && item_eq(a, b))
-            && self.render_queue == other.render_queue
-            && self.render_templates == other.render_templates
-            && self.render_prefs == other.render_prefs
-    }
-    /// The project file's text: the project with the version that wrote it (`savedBy`), checked
-    /// to read back, so a save never writes a file that can't be opened. Values JSON can't hold
-    /// (NaN or infinity, written as `null`, and nesting too deep to parse) are refused on every
-    /// save; debug builds also read the text back.
-    pub fn to_file_json(&self) -> Result<String, ProjectError> {
-        self.to_file_json_with_view(&SavedView::default())
-    }
-    /// [`Project::to_file_json`] that also records the open compositions ([`SavedView`]).
-    pub fn to_file_json_with_view(&self, view: &SavedView) -> Result<String, ProjectError> {
-        if self.schema > SCHEMA_VERSION {
-            return Err(ProjectError::Invalid(format!(
-                "the project can't be saved: it holds a value a project file can't store (project schema {} is newer than this version supports ({SCHEMA_VERSION}))",
-                self.schema
-            )));
-        }
-        #[derive(Serialize)]
-        struct File<'a> {
-            #[serde(rename = "savedBy")]
-            saved_by: &'a str,
-            #[serde(flatten)]
-            view: &'a SavedView,
-            #[serde(flatten)]
-            project: &'a Project,
-        }
-        let file = File { saved_by: APP_VERSION, view, project: self };
-        file_check::check(&file)
-            .map_err(|e| ProjectError::Invalid(format!("the project can't be saved: it holds a value a project file can't store ({e})")))?;
-        let text = serde_json::to_string_pretty(&file).map_err(|e| ProjectError::Invalid(format!("the project can't be saved: {e}")))?;
-        #[cfg(debug_assertions)]
-        Project::from_json(&text)
-            .map_err(|e| ProjectError::Invalid(format!("the project can't be saved: it holds a value a project file can't store ({e})")))?;
-        Ok(text)
-    }
-    pub fn to_json(&self) -> String {
-        serde_json::to_string_pretty(self).unwrap_or_default()
-    }
-    /// [`Project::to_json`] without indentation: smaller and faster (auto-saves).
-    pub fn to_json_compact(&self) -> String {
-        serde_json::to_string(self).unwrap_or_default()
-    }
-    pub fn from_json(s: &str) -> Result<Project, ProjectError> {
-        Project::from_json_repaired(s).map(|(p, _)| p)
-    }
-    /// [`Project::from_json`], also returning one line per value that was out of [`limits`] and
-    /// was corrected (a composition of a billion pixels, a zero frame rate…), so a corrupt or
-    /// hostile file still opens, within bounds, and the user can be told what changed.
-    pub fn from_json_repaired(s: &str) -> Result<(Project, Vec<String>), ProjectError> {
-        let mut p: Project = serde_json::from_str(s).map_err(|e| ProjectError::Invalid(e.to_string()))?;
-        if p.schema > SCHEMA_VERSION {
-            return Err(ProjectError::Invalid(format!("project schema {} is newer than this version supports ({SCHEMA_VERSION})", p.schema)));
-        }
-        p.fix_next_id();
-        let mut notes = vec![];
-        for item in p.items.values_mut() {
-            limits::repair_item(item, &mut notes);
-        }
-        Ok((p, notes))
-    }
-}
-
 #[cfg(test)]
 mod tests;
diff --git a/crates/project/src/render_templates.rs b/crates/project/src/render_templates.rs
index cf52b000e..cadfab2ad 100644
--- a/crates/project/src/render_templates.rs
+++ b/crates/project/src/render_templates.rs
@@ -8,7 +8,9 @@
 
 use serde::{Deserialize, Serialize};
 
-use crate::render_queue::*;
+use crate::render_queue::{
+    AlphaMode, Channels, CurrentOrOff, FieldRender, OutputFormat, OutputModule, ProResProfile, ProxyUse, RenderQuality, RenderSettings, SwitchOverride,
+};
 use effectcraft_time::FrameRate;
 
 /// A default slot (the Defaults section of the Templates dialogs).
@@ -288,6 +290,7 @@ impl RenderTemplates {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::render_queue::{ColorDepth, Crop};
 
     #[test]
     fn builtins_defaults_and_round_trip() {
diff --git a/crates/project/src/settings.rs b/crates/project/src/settings.rs
new file mode 100644
index 000000000..5d3d57204
--- /dev/null
+++ b/crates/project/src/settings.rs
@@ -0,0 +1,314 @@
+use super::item::{ItemId, LayerId};
+use super::{BTreeMap, ColorSpace, Deserialize, Label, Serialize, Tick};
+
+/// The project file schema. 2: effects on layers without a source rectangle (shape, text)
+/// measure positions from the top-left of their comp-sized bounds (effect space), not from
+/// the layer's origin; projects from schema 1 are converted when opened (#227).
+pub const SCHEMA_VERSION: u32 = 2;
+
+/// The first schema in which effect positions are in effect space (see [`SCHEMA_VERSION`]).
+pub const SCHEMA_EFFECT_SPACE: u32 = 2;
+
+/// The EffectCraft version, written into project files as `savedBy`.
+pub const APP_VERSION: &str = env!("CARGO_PKG_VERSION");
+
+/// The EffectCraft version that wrote a project file (its `savedBy`), when it says.
+pub fn saved_by(text: &str) -> Option<String> {
+    #[derive(Deserialize)]
+    struct Meta {
+        #[serde(rename = "savedBy", default)]
+        saved_by: Option<String>,
+    }
+    serde_json::from_str::<Meta>(text).ok()?.saved_by
+}
+
+/// The compositions that were open when a project file was saved and their current times
+/// (`activeComp`, `openComps` and `compTimes` next to `savedBy`), so it reopens where it was left
+/// (#748, #1714). Editor state rather than project
+/// content: opening a comp doesn't make the project unsaved, and it isn't part of
+/// [`Project`]. Older files have none; older versions ignore it.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SavedView {
+    /// The comp shown in the viewer and the Timeline.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub active_comp: Option<ItemId>,
+    /// The open comps (Timeline tabs), in tab order.
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    pub open_comps: Vec<ItemId>,
+    /// Each comp's current time, so a project reopens on the frame it was saved at rather than
+    /// at 0, where its layers may not have started yet (#1714).
+    #[serde(skip_serializing_if = "BTreeMap::is_empty")]
+    pub comp_times: BTreeMap<ItemId, Tick>,
+}
+
+/// The view a project file was saved with ([`SavedView`]); empty for older files. Values that
+/// aren't ids are ignored (whether an id still names a comp is up to the caller).
+pub fn saved_view(text: &str) -> SavedView {
+    #[derive(Deserialize)]
+    struct Meta {
+        #[serde(rename = "activeComp", default)]
+        active_comp: Option<serde_json::Value>,
+        #[serde(rename = "openComps", default)]
+        open_comps: Option<serde_json::Value>,
+        #[serde(rename = "compTimes", default)]
+        comp_times: Option<serde_json::Value>,
+    }
+    let Ok(m) = serde_json::from_str::<Meta>(text) else { return SavedView::default() };
+    SavedView {
+        active_comp: m.active_comp.as_ref().and_then(serde_json::Value::as_u64).map(ItemId),
+        open_comps: m
+            .open_comps
+            .as_ref()
+            .and_then(serde_json::Value::as_array)
+            .map_or_else(Vec::new, |a| a.iter().filter_map(serde_json::Value::as_u64).map(ItemId).collect()),
+        comp_times: m
+            .comp_times
+            .as_ref()
+            .and_then(serde_json::Value::as_object)
+            .map_or_else(BTreeMap::new, |o| o.iter().filter_map(|(k, v)| Some((ItemId(k.parse().ok()?), Tick(v.as_i64()?)))).collect()),
+    }
+}
+
+/// Whether version `a` (`major.minor.patch`, pre-release suffixes ignored) is newer than `b`.
+pub fn is_newer_version(a: &str, b: &str) -> bool {
+    let parts = |v: &str| -> [u64; 3] {
+        let mut n = v.split(['-', '+']).next().unwrap_or("").split('.').map(|x| x.parse().unwrap_or(0));
+        [n.next().unwrap_or(0), n.next().unwrap_or(0), n.next().unwrap_or(0)]
+    };
+    parts(a) > parts(b)
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum ProjectError {
+    #[error("no item {0:?}")]
+    NoItem(ItemId),
+    #[error("item {0:?} is not a composition")]
+    NotComp(ItemId),
+    #[error("no layer {0:?}")]
+    NoLayer(LayerId),
+    #[error("no property `{0}`")]
+    NoProperty(String),
+    #[error("{0}")]
+    Invalid(String),
+}
+
+/// Project bit depth.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum BitDepth {
+    #[default]
+    Bpc8,
+    Bpc16,
+    Bpc32,
+}
+
+impl BitDepth {
+    pub fn label(self) -> &'static str {
+        match self {
+            BitDepth::Bpc8 => "8 bpc",
+            BitDepth::Bpc16 => "16 bpc",
+            BitDepth::Bpc32 => "32 bpc",
+        }
+    }
+    pub fn next(self) -> BitDepth {
+        match self {
+            BitDepth::Bpc8 => BitDepth::Bpc16,
+            BitDepth::Bpc16 => BitDepth::Bpc32,
+            BitDepth::Bpc32 => BitDepth::Bpc8,
+        }
+    }
+    pub fn is_float(self) -> bool {
+        self == BitDepth::Bpc32
+    }
+    /// Quantisation levels per channel of the integer depths (8 bpc: 255; 16 bpc: 32768, After
+    /// Effects' "15 + 1" bit range), `None` for 32 bpc float.
+    pub fn levels(self) -> Option<f32> {
+        match self {
+            BitDepth::Bpc8 => Some(255.0),
+            BitDepth::Bpc16 => Some(32768.0),
+            BitDepth::Bpc32 => None,
+        }
+    }
+    pub fn bits(self) -> u32 {
+        match self {
+            BitDepth::Bpc8 => 8,
+            BitDepth::Bpc16 => 16,
+            BitDepth::Bpc32 => 32,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum TimeDisplayStyle {
+    #[default]
+    Timecode,
+    Frames,
+    /// Feet + Frames, 35 mm film (16 frames per foot).
+    Feet35,
+    /// Feet + Frames, 16 mm film (40 frames per foot).
+    Feet16,
+}
+
+impl TimeDisplayStyle {
+    /// Frames per foot of the Feet + Frames styles.
+    pub fn frames_per_foot(self) -> Option<i64> {
+        match self {
+            TimeDisplayStyle::Feet35 => Some(16),
+            TimeDisplayStyle::Feet16 => Some(40),
+            _ => None,
+        }
+    }
+    pub fn id(self) -> &'static str {
+        match self {
+            TimeDisplayStyle::Timecode => "timecode",
+            TimeDisplayStyle::Frames => "frames",
+            TimeDisplayStyle::Feet35 => "feet35",
+            TimeDisplayStyle::Feet16 => "feet16",
+        }
+    }
+    pub fn parse(s: &str) -> Option<TimeDisplayStyle> {
+        let k: String = s.chars().filter(char::is_ascii_alphanumeric).collect::<String>().to_ascii_lowercase();
+        match k.as_str() {
+            "timecode" => Some(TimeDisplayStyle::Timecode),
+            "frames" => Some(TimeDisplayStyle::Frames),
+            "feet35" | "feetframes" | "feetandframes" | "feet35mm" | "35mm" | "feetframes35mm" => Some(TimeDisplayStyle::Feet35),
+            "feet16" | "feet16mm" | "16mm" | "feetframes16mm" => Some(TimeDisplayStyle::Feet16),
+            _ => None,
+        }
+    }
+}
+
+/// Project Settings ▸ Color ▸ Color Engine.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum ColorEngine {
+    /// Built-in colour management (ICC-style working spaces).
+    #[default]
+    Adobe,
+    /// OCIO managed, with the built-in configuration (ACES working spaces).
+    Ocio,
+}
+
+/// Project Settings ▸ Color ▸ HDR: how over-range (HDR) values reach a standard-dynamic-range
+/// display or output.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub enum HdrMode {
+    /// Values above 1.0 clip.
+    #[default]
+    Clip,
+    /// Highlights above 80% are companded (an exponential knee) into the remaining range.
+    Compand,
+    /// Extended Reinhard tone mapping of luminance (white at 4.0).
+    ToneMap,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct ProjectSettings {
+    pub bit_depth: BitDepth,
+    /// Linearize Working Space: the working space uses linear light (1.0 gamma) for everything
+    /// (sources, effects, blending). Needs a working space.
+    pub linearize: bool,
+    /// Working Space (colour management). `None` = no colour management.
+    #[serde(default)]
+    pub working_space: Option<ColorSpace>,
+    /// Blend Colors Using 1.0 Gamma: layers blend in linear light (sources and effects stay in
+    /// the working space's encoding).
+    #[serde(default)]
+    pub blend_linear: bool,
+    pub time_display: TimeDisplayStyle,
+    /// Frame numbering starts at 0 (or 1).
+    pub frame_start: i64,
+    pub audio_sample_rate: u32,
+    /// Video Rendering and Effects ▸ Use: Mercury GPU Acceleration (`true`, the default; used
+    /// when a GPU adapter exists) or Mercury Software Only (`false`, the CPU compositor).
+    #[serde(default = "yes")]
+    pub gpu_acceleration: bool,
+    /// The project's comment (Metadata panel).
+    #[serde(default, skip_serializing_if = "String::is_empty")]
+    pub comment: String,
+    /// Color Engine (Adobe-style built-in or OCIO with ACES working spaces).
+    #[serde(default)]
+    pub color_engine: ColorEngine,
+    /// HDR handling for standard-dynamic-range output (display and renders).
+    #[serde(default)]
+    pub hdr: HdrMode,
+    /// The space the top-level comp is output in (renders and the viewer's source). `None` =
+    /// sRGB; Rec. 2100 PQ / HLG give HDR output.
+    #[serde(default)]
+    pub output_space: Option<ColorSpace>,
+    /// Working Gamma, 2.2 or 2.4 (`app.project.workingGamma`): with no working space, the curve
+    /// Interpret As Linear Light footage is encoded with and Blend Colors Using 1.0 Gamma
+    /// linearizes with: the sRGB curve at 2.2, a pure 2.4 power curve at 2.4. Ignored with a
+    /// working space (as in After Effects).
+    #[serde(default = "gamma_22")]
+    pub working_gamma: f64,
+}
+
+fn gamma_22() -> f64 {
+    2.2
+}
+
+impl ProjectSettings {
+    /// Working Gamma is 2.4 (anything else reads as 2.2).
+    pub fn working_gamma_24(&self) -> bool {
+        (self.working_gamma - 2.4).abs() < 0.05
+    }
+}
+
+impl Default for ProjectSettings {
+    fn default() -> Self {
+        ProjectSettings {
+            bit_depth: BitDepth::Bpc8,
+            linearize: false,
+            working_space: None,
+            blend_linear: false,
+            time_display: TimeDisplayStyle::Timecode,
+            frame_start: 0,
+            audio_sample_rate: 48_000,
+            gpu_acceleration: true,
+            comment: String::new(),
+            color_engine: ColorEngine::Adobe,
+            hdr: HdrMode::Clip,
+            output_space: None,
+            working_gamma: 2.2,
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
+pub struct Marker {
+    pub time: Tick,
+    #[serde(default)]
+    pub duration: Tick,
+    #[serde(default)]
+    pub comment: String,
+    #[serde(default)]
+    pub label: Label,
+    #[serde(default)]
+    pub chapter: String,
+    #[serde(default)]
+    pub url: String,
+    #[serde(default)]
+    pub protected: bool,
+    /// Web link frame target (`_blank`, a frame name…).
+    #[serde(default, skip_serializing_if = "String::is_empty")]
+    pub frame_target: String,
+    /// Flash/video cue point (Event or Navigation) with name and parameters.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub cue_point: Option<CuePoint>,
+}
+
+/// A marker's cue point (Composition/Layer Marker dialog ▸ Cue Point).
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
+pub struct CuePoint {
+    pub name: String,
+    /// Navigation (true) or Event cue point.
+    #[serde(default)]
+    pub navigation: bool,
+    /// (name, value) parameter pairs.
+    #[serde(default)]
+    pub params: Vec<(String, String)>,
+}
+
+pub(crate) fn yes() -> bool {
+    true
+}
diff --git a/crates/project/src/tests.rs b/crates/project/src/tests.rs
index fe36c7724..f9ee16167 100644
--- a/crates/project/src/tests.rs
+++ b/crates/project/src/tests.rs
@@ -290,3 +290,35 @@ fn comp_contains_ends_on_cycles_long_chains_and_shared_precomps() {
     assert!(p.comp_contains(c[0], c[n - 1]));
     assert!(!p.comp_contains(c[n - 1], c[0]));
 }
+
+/// A Wiggle Paths 100 000 groups deep gets Spatial Phase on a 2 MiB stack.
+#[test]
+fn upgrading_deeply_nested_shape_groups_fits_a_small_stack() {
+    let n = 100_000;
+    let mut next = 1;
+    let mut contents = build::shape_simple_op(&mut Ids(&mut next), "wiggle").unwrap();
+    contents.children.retain(|c| c.match_id() != "spatialPhase");
+    for _ in 0..n {
+        let uid = Ids(&mut next).alloc();
+        contents = crate::PropGroup::new(uid, "group", "Group 1").with(contents);
+    }
+    let h = std::thread::Builder::new()
+        .stack_size(2 << 20)
+        .spawn(move || {
+            let added = build::upgrade_shape_contents(&mut Ids(&mut next), &mut contents);
+            (added, contents)
+        })
+        .unwrap();
+    let (added, mut g) = h.join().unwrap();
+    assert!(added);
+    // One level at a time: dropping the whole tree would recurse as deep as it is nested.
+    let mut depth = 0;
+    while g.match_id == "group" {
+        let Some(crate::Node::Group(child)) = g.children.pop() else { panic!("a nested group") };
+        g = child;
+        depth += 1;
+    }
+    assert_eq!(depth, n);
+    let ids: Vec<&str> = g.children.iter().map(|c| c.match_id()).collect();
+    assert_eq!(ids, ["size", "detail", "points", "speed", "correlation", "phase", "spatialPhase", "seed"]);
+}
diff --git a/crates/psd/src/counters.rs b/crates/psd/src/counters.rs
new file mode 100644
index 000000000..f5c59b02c
--- /dev/null
+++ b/crates/psd/src/counters.rs
@@ -0,0 +1,19 @@
+use std::cell::Cell;
+use std::thread::LocalKey;
+
+thread_local! {
+    /// Scratch rows allocated by the 32-bit ZIP un-predictor.
+    pub static SCRATCH: Cell<usize> = const { Cell::new(0) };
+    /// `inside the mask rect` evaluations of the layer-mask loop.
+    pub static INSIDE: Cell<usize> = const { Cell::new(0) };
+    /// `square_to_quad` solves.
+    pub static QUAD: Cell<usize> = const { Cell::new(0) };
+}
+
+pub fn bump(c: &'static LocalKey<Cell<usize>>) {
+    c.with(|c| c.set(c.get() + 1));
+}
+/// Read and reset.
+pub fn take(c: &'static LocalKey<Cell<usize>>) -> usize {
+    c.with(|c| c.replace(0))
+}
diff --git a/crates/psd/src/lib.rs b/crates/psd/src/lib.rs
index 60a9ab806..91792a837 100644
--- a/crates/psd/src/lib.rs
+++ b/crates/psd/src/lib.rs
@@ -15,411 +15,26 @@ pub mod placed;
 mod read;
 pub mod write;
 
-use std::borrow::Cow;
 use std::sync::Arc;
 
 pub use descriptor::{DValue, Descriptor};
 use read::Reader;
 
-#[derive(Debug, Clone, PartialEq)]
-pub enum Error {
-    NotPsd,
-    Truncated,
-    Unsupported(String),
-    Invalid(String),
-}
+mod limits;
+mod model;
+mod parse;
+mod pixels;
 
-impl std::fmt::Display for Error {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Error::NotPsd => write!(f, "not a Photoshop document"),
-            Error::Truncated => write!(f, "truncated Photoshop document"),
-            Error::Unsupported(s) => write!(f, "unsupported Photoshop feature: {s}"),
-            Error::Invalid(s) => write!(f, "invalid Photoshop document: {s}"),
-        }
-    }
-}
-
-impl std::error::Error for Error {}
-
-pub type Result<T> = std::result::Result<T, Error>;
-
-/// The most pixels one decoded image (the composite, a layer or a mask) may have: 2^28, e.g.
-/// 16 384 × 16 384, 4 GiB as float RGBA. Bounds read from a file are untrusted, so a few bytes
-/// can't make the reader allocate more than that.
-const MAX_DECODE_PIXELS: u64 = 1 << 28;
-
-/// `w × h` as a pixel count, or an error when it exceeds [`MAX_DECODE_PIXELS`].
-fn decode_pixels(w: usize, h: usize) -> Result<usize> {
-    match (w as u64).checked_mul(h as u64) {
-        Some(n) if n <= MAX_DECODE_PIXELS => Ok(n as usize),
-        _ => Err(Error::Unsupported(format!("{w}×{h} pixels is too large to decode"))),
-    }
-}
-
-fn too_large(w: usize, h: usize) -> Error {
-    Error::Unsupported(format!("{w}×{h} pixels is too large to decode"))
-}
-
-/// What one decode (the composite, or one layer) may hold in memory at once: 4 GiB, 1 GiB where
-/// pointers are 32 bits wide (WebAssembly). [`MAX_DECODE_PIXELS`] bounds one image; this bounds
-/// the sum of the buffers a decode keeps alive together.
-#[cfg(target_pointer_width = "32")]
-const DECODE_BUDGET: u64 = 1 << 30;
-#[cfg(not(target_pointer_width = "32"))]
-const DECODE_BUDGET: u64 = 4 << 30;
-
-/// The bytes the buffers of one decode hold right now, against a limit. A decode charges a buffer
-/// before it allocates it (and releases it when it drops it), so a file that would need more
-/// than the limit fails with an error instead of an out-of-memory abort.
-struct Budget {
-    limit: u64,
-    live: u64,
-}
-
-impl Budget {
-    fn new(limit: u64) -> Budget {
-        Budget { limit, live: 0 }
-    }
-
-    fn charge(&mut self, bytes: u64) -> Result<()> {
-        self.check(bytes)?;
-        self.live += bytes;
-        Ok(())
-    }
-
-    /// Whether `bytes` more would still fit, without taking them. A decode checks its whole
-    /// expected peak first, so one that cannot fit fails before it has allocated anything.
-    fn check(&self, bytes: u64) -> Result<()> {
-        match self.live.checked_add(bytes) {
-            Some(total) if total <= self.limit => Ok(()),
-            _ => {
-                const MIB: u64 = 1 << 20;
-                Err(Error::Unsupported(format!(
-                    "decoding needs {} MiB more with {} MiB in use, over the {} MiB memory budget",
-                    bytes / MIB,
-                    self.live / MIB,
-                    self.limit / MIB
-                )))
-            }
-        }
-    }
-
-    fn release(&mut self, bytes: u64) {
-        self.live = self.live.saturating_sub(bytes);
-    }
-
-    /// An empty vector with room for `n` items, charged.
-    fn vec<T>(&mut self, n: usize) -> Result<Vec<T>> {
-        self.charge((n as u64).saturating_mul(std::mem::size_of::<T>() as u64))?;
-        let mut v = Vec::new();
-        v.try_reserve_exact(n).map_err(|_| Error::Unsupported(format!("out of memory for {n} items")))?;
-        Ok(v)
-    }
-
-    /// `n` copies of `value`, charged.
-    fn filled<T: Clone>(&mut self, n: usize, value: T) -> Result<Vec<T>> {
-        let mut v = self.vec::<T>(n)?;
-        v.resize(n, value);
-        Ok(v)
-    }
-}
-
-/// Inflate a zlib stream to at most `limit` bytes.
-fn inflate(src: &[u8], limit: usize) -> Result<Vec<u8>> {
-    miniz_oxide::inflate::decompress_to_vec_zlib_with_limit(src, limit).map_err(|e| Error::Invalid(format!("zip: {e:?}")))
-}
-
-/// Give back what a channel buffer from `Psd::channel_bytes` / `Psd::decode_plane` was charged:
-/// a borrowed one (uncompressed data, or a plane of an inflated stream charged as a whole) was not.
-fn release_bytes(budget: &mut Budget, raw: Cow<'_, [u8]>) {
-    if let Cow::Owned(v) = raw {
-        budget.release(v.len() as u64);
-    }
-}
-
-/// A 32-bit float sample made safe to use: NaN reads as 0, +inf as white (1.0, like the integer
-/// depths' maximum), -inf as 0.
-fn finite_sample(v: f32) -> f32 {
-    if v.is_nan() {
-        0.0
-    } else if v == f32::INFINITY {
-        1.0
-    } else if v == f32::NEG_INFINITY {
-        0.0
-    } else {
-        v
-    }
-}
-
-/// Whether `bytes` start like a Photoshop document.
-pub fn is_psd(bytes: &[u8]) -> bool {
-    bytes.len() >= 6 && &bytes[..4] == b"8BPS" && matches!(u16::from_be_bytes([bytes[4], bytes[5]]), 1 | 2)
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum ColorMode {
-    Bitmap,
-    Grayscale,
-    Indexed,
-    Rgb,
-    Cmyk,
-    Multichannel,
-    Duotone,
-    Lab,
-}
-
-impl ColorMode {
-    pub fn from_u16(v: u16) -> Option<ColorMode> {
-        Some(match v {
-            0 => ColorMode::Bitmap,
-            1 => ColorMode::Grayscale,
-            2 => ColorMode::Indexed,
-            3 => ColorMode::Rgb,
-            4 => ColorMode::Cmyk,
-            7 => ColorMode::Multichannel,
-            8 => ColorMode::Duotone,
-            9 => ColorMode::Lab,
-            _ => return None,
-        })
-    }
-    pub fn to_u16(self) -> u16 {
-        match self {
-            ColorMode::Bitmap => 0,
-            ColorMode::Grayscale => 1,
-            ColorMode::Indexed => 2,
-            ColorMode::Rgb => 3,
-            ColorMode::Cmyk => 4,
-            ColorMode::Multichannel => 7,
-            ColorMode::Duotone => 8,
-            ColorMode::Lab => 9,
-        }
-    }
-    /// Number of colour channels (before alpha).
-    pub fn color_channels(self) -> usize {
-        match self {
-            ColorMode::Rgb | ColorMode::Lab => 3,
-            ColorMode::Cmyk => 4,
-            _ => 1,
-        }
-    }
-}
-
-/// A rectangle in document pixels (`right`/`bottom` exclusive).
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
-pub struct Rect {
-    pub top: i32,
-    pub left: i32,
-    pub bottom: i32,
-    pub right: i32,
-}
-
-impl Rect {
-    pub fn new(left: i32, top: i32, width: i32, height: i32) -> Rect {
-        Rect { top, left, bottom: top.saturating_add(height), right: left.saturating_add(width) }
-    }
-    pub fn width(&self) -> u32 {
-        (i64::from(self.right) - i64::from(self.left)).clamp(0, i64::from(u32::MAX)) as u32
-    }
-    pub fn height(&self) -> u32 {
-        (i64::from(self.bottom) - i64::from(self.top)).clamp(0, i64::from(u32::MAX)) as u32
-    }
-    pub fn is_empty(&self) -> bool {
-        self.width() == 0 || self.height() == 0
-    }
-}
-
-/// One channel of a layer: id (0.. colour, -1 transparency, -2 layer mask, -3 real user mask) and
-/// where its data (compression + image data) sits in the file.
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub struct ChannelInfo {
-    pub id: i16,
-    pub offset: usize,
-    pub len: usize,
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub struct LayerMask {
-    pub rect: Rect,
-    /// Value outside the mask rectangle (0 or 255).
-    pub default_color: u8,
-    pub disabled: bool,
-    pub inverted: bool,
-}
-
-/// Layer kind from the section divider setting (`lsct`).
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
-pub enum Section {
-    #[default]
-    Layer,
-    OpenFolder,
-    ClosedFolder,
-    /// The hidden "</Layer group>" record that closes a group (below its children).
-    Divider,
-}
-
-/// A type layer (`TySh`).
-#[derive(Clone, Debug, Default, PartialEq)]
-pub struct TextInfo {
-    /// Text with `\n` line breaks.
-    pub text: String,
-    /// Affine transform (xx, xy, yx, yy, tx, ty): the text origin sits at (tx, ty).
-    pub transform: [f64; 6],
-    pub style: engine_data::TextStyle,
-    /// Text bounds (left, top, right, bottom) relative to the origin, when stored.
-    pub bounds: Option<[f64; 4]>,
-}
-
-/// Adjustment layers (best effort).
-#[derive(Clone, Debug, PartialEq)]
-pub enum Adjustment {
-    Invert,
-    BrightnessContrast {
-        brightness: f64,
-        contrast: f64,
-        legacy: bool,
-    },
-    HueSaturation {
-        hue: f64,
-        saturation: f64,
-        lightness: f64,
-        colorize: bool,
-    },
-    Levels {
-        in_black: f64,
-        in_white: f64,
-        gamma: f64,
-        out_black: f64,
-        out_white: f64,
-    },
-    Exposure {
-        exposure: f64,
-        offset: f64,
-        gamma: f64,
-    },
-    /// Another adjustment (its tagged-block key, e.g. `curv`, `blnc`).
-    Other(String),
-}
-
-/// A vector mask path: sub-paths of (in tangent, vertex, out tangent) points in document pixels.
-#[derive(Clone, Debug, Default, PartialEq)]
-pub struct VectorMask {
-    pub inverted: bool,
-    pub disabled: bool,
-    pub subpaths: Vec<SubPath>,
-}
-
-#[derive(Clone, Debug, Default, PartialEq)]
-pub struct SubPath {
-    pub closed: bool,
-    /// Per knot: [control point preceding, anchor, control point leaving] as (x, y).
-    pub knots: Vec<[[f64; 2]; 3]>,
-}
-
-/// A placed layer (smart object): `SoLd` / `SoLE` (placed layer data) or the older `PlLd`.
-#[derive(Clone, Debug, Default, PartialEq)]
-pub struct SmartObject {
-    /// Unique id of the linked file ([`Psd::linked`]) the layer shows.
-    pub uuid: String,
-    /// Where the content's corners sit in document pixels: top-left, top-right, bottom-right,
-    /// bottom-left.
-    pub quad: [[f64; 2]; 4],
-    /// The content's size in pixels (`Sz  `), when recorded.
-    pub size: Option<[f64; 2]>,
-    /// The placed layer's warp (`warp`), when it has one ([`placed`]).
-    pub warp: Option<placed::Warp>,
-}
-
-impl SmartObject {
-    /// The quad as an affine placement of a `w`×`h` content rectangle: (centre, scale x, scale
-    /// y, rotation in degrees). Perspective and skew are dropped.
-    pub fn placement(&self, w: f64, h: f64) -> ([f64; 2], f64, f64, f64) {
-        let q = self.quad;
-        let centre = [(q[0][0] + q[1][0] + q[2][0] + q[3][0]) / 4.0, (q[0][1] + q[1][1] + q[2][1] + q[3][1]) / 4.0];
-        let top = [q[1][0] - q[0][0], q[1][1] - q[0][1]];
-        let left = [q[3][0] - q[0][0], q[3][1] - q[0][1]];
-        let sx = top[0].hypot(top[1]) / w.max(1e-9);
-        let sy = left[0].hypot(left[1]) / h.max(1e-9);
-        // Mirrored content (left edge turning the other way) keeps a negative y scale.
-        let cross = top[0] * left[1] - top[1] * left[0];
-        (centre, sx, if cross < 0.0 { -sy } else { sy }, top[1].atan2(top[0]).to_degrees())
-    }
-}
-
-/// A file embedded in (or linked from) the document: linked layer data (`lnk2`, `lnkD`,
-/// `lnk3`, `lnkE`).
-#[derive(Clone, Debug, Default, PartialEq)]
-pub struct LinkedFile {
-    pub uuid: String,
-    pub name: String,
-    /// File type code (`8BPS`, `PNGf`, `JPEG`…), may be blank.
-    pub file_type: String,
-    /// Embedded data (absent for externally linked files).
-    pub data: Option<std::ops::Range<usize>>,
-}
-
-#[derive(Clone, Debug, Default, PartialEq)]
-pub struct Layer {
-    /// Index in [`Psd::layers`] (file order: bottom of the stack first).
-    pub index: usize,
-    pub name: String,
-    pub id: Option<u32>,
-    pub rect: Rect,
-    /// Blend mode key (`norm`, `mul `, `pass`…).
-    pub blend: [u8; 4],
-    pub opacity: u8,
-    /// Fill opacity (`iOpa`), 255 when absent.
-    pub fill_opacity: u8,
-    /// Clipped to the layer below.
-    pub clipping: bool,
-    pub hidden: bool,
-    pub protect_transparency: bool,
-    pub section: Section,
-    pub channels: Vec<ChannelInfo>,
-    pub mask: Option<LayerMask>,
-    pub text: Option<TextInfo>,
-    pub adjustment: Option<Adjustment>,
-    /// Solid colour fill layer (`SoCo`), RGB 0..1.
-    pub fill: Option<[f64; 3]>,
-    /// Layer effects (`lfx2` descriptor).
-    pub effects: Option<Descriptor>,
-    pub vector_mask: Option<VectorMask>,
-    /// Smart object placement.
-    pub smart_object: Option<SmartObject>,
-    /// Keys of every additional-information block the layer carries.
-    pub keys: Vec<[u8; 4]>,
-}
-
-impl Layer {
-    pub fn is_group(&self) -> bool {
-        matches!(self.section, Section::OpenFolder | Section::ClosedFolder)
-    }
-    pub fn blend_key(&self) -> &str {
-        std::str::from_utf8(&self.blend).unwrap_or("norm")
-    }
-    pub fn has_pixels(&self) -> bool {
-        !self.rect.is_empty() && self.channels.iter().any(|c| c.id >= 0)
-    }
-}
-
-/// How deep groups nest in [`Psd::tree`]; deeper ones are flattened (a hostile file can nest
-/// thousands, and walking or dropping that tree would overflow the stack).
-pub const MAX_GROUP_DEPTH: usize = 64;
-
-/// The layer tree, top of the stack first.
-#[derive(Clone, Debug, PartialEq)]
-pub enum Node {
-    Layer(usize),
-    Group { layer: usize, children: Vec<Node> },
-}
-
-/// Decoded pixels: straight RGBA, row-major.
-#[derive(Clone, Debug, PartialEq)]
-pub struct Pixels {
-    pub width: u32,
-    pub height: u32,
-    pub data: Vec<[f32; 4]>,
-}
+#[cfg(test)]
+use limits::{Budget, decode_pixels};
+pub use limits::{Error, Result};
+pub use model::{
+    Adjustment, ChannelInfo, ColorMode, Layer, LayerMask, LinkedFile, MAX_GROUP_DEPTH, Node, Pixels, Rect, Section, SmartObject, SubPath, TextInfo, VectorMask,
+};
+pub use parse::is_psd;
+pub(crate) use pixels::pack_bits;
+#[cfg(test)]
+use pixels::{lab_to_rgb, srgb_encode, unpack_bits};
 
 /// A parsed Photoshop document.
 #[derive(Clone, Debug)]
@@ -446,1078 +61,11 @@ pub struct Psd {
     merged_offset: usize,
 }
 
-impl Psd {
-    pub fn parse(data: impl Into<Arc<[u8]>>) -> Result<Psd> {
-        let data: Arc<[u8]> = data.into();
-        let mut r = Reader::new(&data);
-        if r.bytes(4).ok() != Some(b"8BPS") {
-            return Err(Error::NotPsd);
-        }
-        let version = r.u16()?;
-        let psb = match version {
-            1 => false,
-            2 => true,
-            _ => return Err(Error::NotPsd),
-        };
-        r.skip(6)?;
-        let channels = r.u16()?;
-        let height = r.u32()?;
-        let width = r.u32()?;
-        let depth = r.u16()?;
-        let mode_v = r.u16()?;
-        let mode = ColorMode::from_u16(mode_v).ok_or_else(|| Error::Unsupported(format!("colour mode {mode_v}")))?;
-        if !matches!(depth, 1 | 8 | 16 | 32) {
-            return Err(Error::Unsupported(format!("{depth}-bit")));
-        }
-        if width == 0 || height == 0 || width > 300_000 || height > 300_000 {
-            return Err(Error::Invalid(format!("size {width}x{height}")));
-        }
-        // Colour mode data.
-        let n = r.u32()? as usize;
-        let palette = r.bytes(n)?.to_vec();
-        // Image resources.
-        let n = r.u32()? as usize;
-        r.skip(n)?;
-        // Layer and mask information.
-        let mut psd = Psd {
-            psb,
-            width,
-            height,
-            channels,
-            depth,
-            mode,
-            layers: vec![],
-            merged_alpha: false,
-            palette,
-            linked: vec![],
-            warnings: vec![],
-            data: data.clone(),
-            merged_offset: 0,
-        };
-        let lm_len = r.length(psb)?;
-        let lm_end = r.pos.checked_add(lm_len).filter(|&e| e <= data.len()).ok_or(Error::Truncated)?;
-        if lm_len > 0 {
-            let li_len = r.length(psb)?;
-            let li_end = r.pos.checked_add(li_len).filter(|&e| e <= lm_end).ok_or(Error::Truncated)?;
-            if li_len > 0
-                && let Err(e) = psd.layer_info(&data, r.pos, li_end)
-            {
-                // A damaged layer section must not discard the document: keep the header and the
-                // merged image, drop the layers and say so. Without a merged image there is
-                // nothing to fall back to, so the original error stands.
-                if lm_end.checked_add(2).is_none_or(|n| n > data.len()) {
-                    return Err(e);
-                }
-                psd.layers.clear();
-                psd.warnings.push(format!("Layers could not be read ({e}); only the flattened image is available"));
-            }
-            r.pos = li_end;
-            if r.pos + 4 <= lm_end {
-                let g = r.u32()? as usize;
-                r.pos = (r.pos + g).min(lm_end);
-            }
-            // Global additional layer information (16/32-bit layer info lives here).
-            while let Some((key, start, end)) = next_block(&data, &mut r.pos, lm_end, psb) {
-                if matches!(&key, b"lnk2" | b"lnkD" | b"lnk3" | b"lnkE") {
-                    psd.linked_files(&data, start, end);
-                }
-                if matches!(&key, b"Lr16" | b"Lr32" | b"Layr") && psd.layers.is_empty() && end > start {
-                    // The block holds the layer info, normally without its length field; accept
-                    // both layouts.
-                    if psd.layer_info(&data, start, end).is_err() || psd.layers.is_empty() {
-                        psd.layers.clear();
-                        let skip = if psb { 8 } else { 4 };
-                        if start + skip < end && psd.layer_info(&data, start + skip, end).is_err() {
-                            psd.layers.clear();
-                        }
-                    }
-                }
-                r.pos = end;
-            }
-        }
-        if !psd.layers.is_empty() {
-            // A 16/32-bit layer block recovered the layers.
-            psd.warnings.clear();
-        }
-        psd.merged_offset = lm_end;
-        Ok(psd)
-    }
-
-    /// The embedded bytes of linked file `uuid`.
-    pub fn linked_data(&self, uuid: &str) -> Option<&[u8]> {
-        let f = self.linked.iter().find(|f| f.uuid == uuid)?;
-        self.data.get(f.data.clone()?)
-    }
-
-    /// Linked layer data records (spec: "Linked Layer"): length, kind (`liFD` embedded data,
-    /// `liFE` external file, `liFA` alias), version, unique id, original file name, type,
-    /// creator, data length, optional descriptors, then the data. A damaged record ends the list.
-    fn linked_files(&mut self, data: &[u8], start: usize, end: usize) {
-        let mut pos = start;
-        while pos + 8 <= end {
-            let mut r = Reader::at(&data[..end], pos);
-            let Ok(len) = r.u64() else { break };
-            let body = r.pos;
-            let Some(rec_end) = body.checked_add(len as usize).filter(|e| *e <= end) else { break };
-            let mut r = Reader::at(&data[..rec_end], body);
-            let rec = (|| -> Result<LinkedFile> {
-                let kind = r.tag()?;
-                let version = r.u32()?;
-                let n = r.u8()? as usize;
-                let uuid = String::from_utf8_lossy(r.bytes(n)?).into_owned();
-                let name = descriptor::read_unicode(&mut r)?;
-                let file_type = String::from_utf8_lossy(&r.tag()?).trim().to_string();
-                let _creator = r.tag()?;
-                let dlen = r.u64()? as usize;
-                if r.u8()? != 0 {
-                    let _v = r.u32()?;
-                    descriptor::read_descriptor(&mut r)?;
-                }
-                let mut out = LinkedFile { uuid, name, file_type, data: None };
-                match &kind {
-                    b"liFD" => {
-                        let s = r.pos;
-                        r.skip(dlen)?;
-                        out.data = Some(s..s + dlen);
-                    }
-                    b"liFE" => {
-                        let _v = r.u32()?;
-                        descriptor::read_descriptor(&mut r)?;
-                        if version > 3 {
-                            r.skip(4 + 4 + 8)?;
-                        }
-                        let _size = r.u64()?;
-                        if version > 2 && r.remaining() >= dlen && dlen > 0 {
-                            let s = r.pos;
-                            out.data = Some(s..s + dlen);
-                        }
-                    }
-                    _ => {}
-                }
-                Ok(out)
-            })();
-            match rec {
-                Ok(f) => self.linked.push(f),
-                Err(_) => break,
-            }
-            pos = rec_end.div_ceil(4) * 4;
-        }
-    }
-
-    fn layer_info(&mut self, data: &[u8], start: usize, end: usize) -> Result<()> {
-        let mut r = Reader::at(&data[..end], start);
-        let count = r.i16()?;
-        self.merged_alpha = count < 0;
-        let n = count.unsigned_abs() as usize;
-        let mut layers = Vec::with_capacity(n);
-        for i in 0..n {
-            layers.push(self.layer_record(&mut r, i)?);
-        }
-        // Channel image data follows in record order.
-        for l in &mut layers {
-            for c in &mut l.channels {
-                c.offset = r.pos;
-                r.skip(c.len)?;
-            }
-        }
-        self.layers = layers;
-        Ok(())
-    }
-
-    fn layer_record(&self, r: &mut Reader, index: usize) -> Result<Layer> {
-        let psb = self.psb;
-        let (top, left, bottom, right) = (r.i32()?, r.i32()?, r.i32()?, r.i32()?);
-        let nch = r.u16()? as usize;
-        if nch > 64 {
-            return Err(Error::Invalid("channel count".into()));
-        }
-        let mut channels = Vec::with_capacity(nch);
-        for _ in 0..nch {
-            let id = r.i16()?;
-            let len = r.length(psb)?;
-            channels.push(ChannelInfo { id, offset: 0, len });
-        }
-        if r.bytes(4)? != b"8BIM" {
-            return Err(Error::Invalid("layer record signature".into()));
-        }
-        let blend = r.tag()?;
-        let opacity = r.u8()?;
-        let clipping = r.u8()? != 0;
-        let flags = r.u8()?;
-        r.skip(1)?;
-        let extra = r.u32()? as usize;
-        let extra_end = r.pos.checked_add(extra).filter(|&e| e <= r.data.len()).ok_or(Error::Truncated)?;
-        let mut l = Layer {
-            index,
-            rect: Rect { top, left, bottom, right },
-            blend,
-            opacity,
-            fill_opacity: 255,
-            clipping,
-            hidden: flags & 2 != 0,
-            protect_transparency: flags & 1 != 0,
-            channels,
-            ..Default::default()
-        };
-        // Layer mask data.
-        let mlen = r.u32()? as usize;
-        let mstart = r.pos;
-        if mlen >= 18 {
-            let rect = Rect { top: r.i32()?, left: r.i32()?, bottom: r.i32()?, right: r.i32()? };
-            let default_color = r.u8()?;
-            let mflags = r.u8()?;
-            l.mask = Some(LayerMask { rect, default_color, disabled: mflags & 2 != 0, inverted: mflags & 4 != 0 });
-        }
-        r.pos = mstart + mlen;
-        // Blending ranges.
-        let blen = r.u32()? as usize;
-        r.skip(blen)?;
-        l.name = r.pascal(4)?;
-        let mut pos = r.pos;
-        let data = r.data;
-        while let Some((key, start, end)) = next_block(data, &mut pos, extra_end, psb) {
-            l.keys.push(key);
-            let block = &data[start..end];
-            // A malformed block only loses that block's information.
-            let _ = self.layer_block(&mut l, &key, block);
-            pos = end;
-        }
-        r.pos = extra_end;
-        Ok(l)
-    }
-
-    fn layer_block(&self, l: &mut Layer, key: &[u8; 4], b: &[u8]) -> Result<()> {
-        let mut r = Reader::new(b);
-        match key {
-            b"luni" => {
-                let name = descriptor::read_unicode(&mut r)?;
-                if !name.is_empty() {
-                    l.name = name;
-                }
-            }
-            b"lyid" => l.id = Some(r.u32()?),
-            b"iOpa" => l.fill_opacity = r.u8()?,
-            b"lsct" | b"lsdk" => {
-                l.section = match r.u32()? {
-                    1 => Section::OpenFolder,
-                    2 => Section::ClosedFolder,
-                    3 => Section::Divider,
-                    _ => Section::Layer,
-                };
-                if b.len() >= 12 && &b[4..8] == b"8BIM" {
-                    l.blend.copy_from_slice(&b[8..12]);
-                }
-            }
-            b"TySh" => {
-                let _ver = r.u16()?;
-                let mut t = [0.0; 6];
-                for v in &mut t {
-                    *v = r.f64()?;
-                }
-                // A transform with NaN/inf is unusable: fall back to the identity.
-                if t.iter().any(|v| !v.is_finite()) {
-                    t = [1.0, 0.0, 0.0, 1.0, 0.0, 0.0];
-                }
-                let _text_ver = r.u16()?;
-                let _desc_ver = r.u32()?;
-                let d = descriptor::read_descriptor(&mut r)?;
-                let text = d.text("Txt ").unwrap_or_default().replace("\r\n", "\n").replace('\r', "\n");
-                let text = text.strip_suffix('\n').map(str::to_string).unwrap_or(text);
-                let style = d.raw("EngineData").map(|e| engine_data::text_style(&engine_data::parse(e))).unwrap_or_default();
-                let bounds =
-                    d.obj("bounds").or_else(|| d.obj("boundingBox")).and_then(|o| Some([o.num("Left")?, o.num("Top ")?, o.num("Rght")?, o.num("Btom")?]));
-                l.text = Some(TextInfo { text, transform: t, style, bounds });
-            }
-            b"lfx2" => {
-                let _ver = r.u32()?;
-                let _dver = r.u32()?;
-                l.effects = Some(descriptor::read_descriptor(&mut r)?);
-            }
-            b"SoCo" => {
-                let _ver = r.u32()?;
-                let d = descriptor::read_descriptor(&mut r)?;
-                l.fill = d.color("Clr ");
-            }
-            b"nvrt" => l.adjustment = Some(Adjustment::Invert),
-            b"brit" => {
-                let brightness = r.i16()? as f64;
-                let contrast = r.i16()? as f64;
-                if l.adjustment.is_none() {
-                    l.adjustment = Some(Adjustment::BrightnessContrast { brightness, contrast, legacy: true });
-                }
-            }
-            b"CgEd" => {
-                let _ver = r.u32()?;
-                let d = descriptor::read_descriptor(&mut r)?;
-                l.adjustment = Some(Adjustment::BrightnessContrast {
-                    brightness: d.num("Brgh").unwrap_or(0.0),
-                    contrast: d.num("Cntr").unwrap_or(0.0),
-                    legacy: d.bool("useLegacy").unwrap_or(false),
-                });
-            }
-            b"hue2" | b"hue " => {
-                let _ver = r.u16()?;
-                let colorize = r.u8()? != 0;
-                r.skip(1)?;
-                let ch = (r.i16()? as f64, r.i16()? as f64, r.i16()? as f64);
-                let m = (r.i16()? as f64, r.i16()? as f64, r.i16()? as f64);
-                let (hue, saturation, lightness) = if colorize { ch } else { m };
-                l.adjustment = Some(Adjustment::HueSaturation { hue, saturation, lightness, colorize });
-            }
-            b"levl" => {
-                let _ver = r.u16()?;
-                let (ib, iw, ob, ow, g) = (r.i16()?, r.i16()?, r.i16()?, r.i16()?, r.i16()?);
-                l.adjustment =
-                    Some(Adjustment::Levels { in_black: ib as f64, in_white: iw as f64, gamma: g as f64 / 100.0, out_black: ob as f64, out_white: ow as f64 });
-            }
-            b"expA" => {
-                let _ver = r.u16()?;
-                let mut finite = |default: f64| -> Result<f64> {
-                    let v = f64::from(r.f32()?);
-                    Ok(if v.is_finite() { v } else { default })
-                };
-                let exposure = finite(0.0)?;
-                let offset = finite(0.0)?;
-                let gamma = finite(1.0)?;
-                l.adjustment = Some(Adjustment::Exposure { exposure, offset, gamma });
-            }
-            b"curv" | b"blnc" | b"post" | b"thrs" | b"selc" | b"mixr" | b"phfl" | b"vibA" | b"blwh" | b"grdm" | b"clrL" if l.adjustment.is_none() => {
-                l.adjustment = Some(Adjustment::Other(String::from_utf8_lossy(key).into_owned()));
-            }
-            b"SoLd" | b"SoLE" => {
-                let _id = r.tag()?;
-                let _ver = r.u32()?;
-                let _dver = r.u32()?;
-                let d = descriptor::read_descriptor(&mut r)?;
-                let uuid = d.text("Idnt").unwrap_or_default().to_string();
-                let t = placed::eight(&d, "Trnf").unwrap_or([0.0; 8]);
-                // The non-affine transform when present (perspective), else the transform.
-                let t = placed::eight(&d, "nonAffineTransform").unwrap_or(t);
-                let size = d.obj("Sz  ").and_then(|s| Some([s.num("Wdth")?, s.num("Hght")?]));
-                let warp = d.obj("warp").and_then(placed::Warp::read);
-                l.smart_object = Some(SmartObject { uuid, quad: placed::quad_from(t), size, warp });
-            }
-            b"PlLd" if l.smart_object.is_none() => {
-                let _id = r.tag()?;
-                let _ver = r.u32()?;
-                let n = r.u8()? as usize;
-                let uuid = String::from_utf8_lossy(r.bytes(n)?).into_owned();
-                let _page = r.u32()?;
-                let _pages = r.u32()?;
-                let _aa = r.u32()?;
-                let _ty = r.u32()?;
-                let mut t = [0.0; 8];
-                for v in &mut t {
-                    *v = r.f64_finite()?;
-                }
-                l.smart_object = Some(SmartObject { uuid, quad: placed::quad_from(t), size: None, warp: None });
-            }
-            b"vmsk" | b"vsms" => {
-                let _ver = r.u32()?;
-                let flags = r.u32()?;
-                l.vector_mask = Some(self.vector_paths(&mut r, flags)?);
-            }
-            _ => {}
-        }
-        Ok(())
-    }
-
-    fn vector_paths(&self, r: &mut Reader, flags: u32) -> Result<VectorMask> {
-        let (w, h) = (self.width as f64, self.height as f64);
-        let mut vm = VectorMask { inverted: flags & 1 != 0, disabled: flags & 4 != 0, subpaths: vec![] };
-        let fixed = |r: &mut Reader| -> Result<f64> { Ok(r.i32()? as f64 / (1 << 24) as f64) };
-        while r.remaining() >= 26 {
-            let sel = r.u16()?;
-            match sel {
-                0 | 3 => {
-                    let _n = r.u16()?;
-                    r.skip(22)?;
-                    vm.subpaths.push(SubPath { closed: sel == 0, knots: vec![] });
-                }
-                1 | 2 | 4 | 5 => {
-                    let mut pts = [[0.0; 2]; 3];
-                    for p in &mut pts {
-                        let y = fixed(r)?;
-                        let x = fixed(r)?;
-                        *p = [x * w, y * h];
-                    }
-                    if let Some(sp) = vm.subpaths.last_mut() {
-                        sp.knots.push(pts);
-                    }
-                }
-                _ => r.skip(24)?,
-            }
-        }
-        vm.subpaths.retain(|s| !s.knots.is_empty());
-        Ok(vm)
-    }
-
-    /// The layer tree, top of the stack first. Groups nest at most [`MAX_GROUP_DEPTH`] deep (see
-    /// [`Psd::tree_report`]).
-    pub fn tree(&self) -> Vec<Node> {
-        self.tree_report().0
-    }
-
-    /// The layer tree plus the number of groups nested deeper than [`MAX_GROUP_DEPTH`]. Those
-    /// are flattened into their deepest allowed ancestor: their children stay, in order, and
-    /// the group record itself becomes a plain [`Node::Layer`], so no layer is lost and the
-    /// tree (and its `Drop`, `Clone` and `PartialEq`) cannot recurse deeper than the limit.
-    pub fn tree_report(&self) -> (Vec<Node>, usize) {
-        let mut stack: Vec<Vec<Node>> = vec![vec![]];
-        // Dividers seen while `MAX_GROUP_DEPTH` groups were already open.
-        let mut flattened_open = 0usize;
-        let mut flattened = 0usize;
-        for l in &self.layers {
-            match l.section {
-                Section::Divider => {
-                    if stack.len() > MAX_GROUP_DEPTH {
-                        flattened_open += 1;
-                    } else {
-                        stack.push(vec![]);
-                    }
-                }
-                Section::OpenFolder | Section::ClosedFolder => {
-                    if flattened_open > 0 {
-                        flattened_open -= 1;
-                        flattened += 1;
-                        if let Some(top) = stack.last_mut() {
-                            top.push(Node::Layer(l.index));
-                        }
-                        continue;
-                    }
-                    let children = if stack.len() > 1 { stack.pop().unwrap_or_default() } else { vec![] };
-                    if let Some(top) = stack.last_mut() {
-                        top.push(Node::Group { layer: l.index, children });
-                    }
-                }
-                Section::Layer => {
-                    if let Some(top) = stack.last_mut() {
-                        top.push(Node::Layer(l.index));
-                    }
-                }
-            }
-        }
-        while stack.len() > 1 {
-            let c = stack.pop().unwrap_or_default();
-            if let Some(top) = stack.last_mut() {
-                top.extend(c);
-            }
-        }
-        // Depth is at most `MAX_GROUP_DEPTH`, so recursion is bounded.
-        fn rev(v: &mut Vec<Node>) {
-            v.reverse();
-            for n in v {
-                if let Node::Group { children, .. } = n {
-                    rev(children);
-                }
-            }
-        }
-        let mut out = stack.pop().unwrap_or_default();
-        rev(&mut out);
-        (out, flattened)
-    }
-
-    fn bytes_per_sample(&self) -> usize {
-        match self.depth {
-            16 => 2,
-            32 => 4,
-            _ => 1,
-        }
-    }
-
-    /// The raw big-endian bytes of one channel of `w`×`h` samples at `offset` (compression field
-    /// first): `row_bytes(w) × h` of them with the compression and the prediction undone.
-    /// Uncompressed data is borrowed from the file, not copied; any other buffer is charged to
-    /// `budget` and the caller releases it (see [`release_bytes`]) once it is dropped.
-    fn channel_bytes(&self, offset: usize, len: usize, w: usize, h: usize, budget: &mut Budget) -> Result<Cow<'_, [u8]>> {
-        let end = offset.checked_add(len).filter(|&e| e <= self.data.len()).ok_or(Error::Truncated)?;
-        let mut r = Reader::at(self.data.get(..end).ok_or(Error::Truncated)?, offset);
-        let comp = r.u16()?;
-        decode_pixels(w, h)?;
-        self.plane_bytes(comp, &mut r, w, h, budget)
-    }
-
-    /// The raw bytes (`row_bytes(w)` × `h`, ZIP prediction undone) of one channel whose pixel data
-    /// follows `r`'s position (after the compression field). Uncompressed data is borrowed, not
-    /// copied; the other buffers are charged to `budget`.
-    fn plane_bytes<'a>(&self, comp: u16, r: &mut Reader<'a>, w: usize, h: usize, budget: &mut Budget) -> Result<Cow<'a, [u8]>> {
-        let rowb = self.row_bytes(w);
-        let size = rowb.checked_mul(h).ok_or_else(|| too_large(w, h))?;
-        Ok(match self.open_planes(comp, r, 1, 1, w, h, budget)? {
-            PlaneStream::Raw => Cow::Borrowed(r.bytes(size)?),
-            PlaneStream::Rle(counts) => Cow::Owned(Self::unpack_plane(&counts, 0, r, rowb, h, budget)?),
-            PlaneStream::Zip(mut v) => {
-                v.resize(size, 0);
-                self.zip_plane(comp, &mut v, 0, w, h)?;
-                Cow::Owned(v)
-            }
-        })
-    }
-
-    /// Prepare the pixel data at `r` (just after the compression field) of `total` planes of
-    /// `w`×`h` samples, of which the first `want` are decoded: the RLE row sizes of every plane,
-    /// or the inflated ZIP data, which holds all planes one after another (charged to `budget`
-    /// before it is inflated).
-    #[allow(clippy::too_many_arguments)]
-    fn open_planes(&self, comp: u16, r: &mut Reader, total: usize, want: usize, w: usize, h: usize, budget: &mut Budget) -> Result<PlaneStream> {
-        let size = self.row_bytes(w).checked_mul(h).ok_or_else(|| too_large(w, h))?;
-        Ok(match comp {
-            0 => PlaneStream::Raw,
-            1 => {
-                let n = total.saturating_mul(h);
-                let mut counts = Vec::with_capacity(n.min(r.remaining() / 2));
-                for _ in 0..n {
-                    counts.push(if self.psb { r.u32()? as usize } else { r.u16()? as usize });
-                }
-                PlaneStream::Rle(counts)
-            }
-            2 | 3 => {
-                let rest = r.bytes(r.remaining())?;
-                // One stream holds every plane: what it may decode to is what they need.
-                let all = size.checked_mul(want).ok_or_else(|| too_large(w, h))?;
-                budget.charge(all as u64)?;
-                PlaneStream::Zip(inflate(rest, all)?)
-            }
-            c => return Err(Error::Unsupported(format!("compression {c}"))),
-        })
-    }
-
-    /// The raw bytes (`row_bytes(w)` × `h`, ZIP prediction undone) of plane `c`: raw and RLE
-    /// planes are read from `r` in order, raw ones borrowed from the file data, ZIP ones from the
-    /// inflated buffer (un-predicted in place; already charged by `open_planes`), RLE ones charged
-    /// to `budget`.
-    #[allow(clippy::too_many_arguments)]
-    fn decode_plane<'x, 'a: 'x>(
-        &self,
-        comp: u16,
-        planes: &'x mut PlaneStream,
-        r: &mut Reader<'a>,
-        c: usize,
-        w: usize,
-        h: usize,
-        budget: &mut Budget,
-    ) -> Result<Cow<'x, [u8]>> {
-        let rowb = self.row_bytes(w);
-        let size = rowb.checked_mul(h).ok_or_else(|| too_large(w, h))?;
-        Ok(match planes {
-            PlaneStream::Raw => Cow::Borrowed(r.bytes(size)?),
-            PlaneStream::Rle(counts) => Cow::Owned(Self::unpack_plane(counts, c, r, rowb, h, budget)?),
-            PlaneStream::Zip(v) => Cow::Borrowed(self.zip_plane(comp, v, c, w, h)?),
-        })
-    }
-
-    /// Unpack the `h` RLE rows of plane `c` (row byte counts `counts`, plane after plane) into a
-    /// buffer charged to `budget`.
-    fn unpack_plane(counts: &[usize], c: usize, r: &mut Reader, rowb: usize, h: usize, budget: &mut Budget) -> Result<Vec<u8>> {
-        let mut out = budget.vec::<u8>(rowb.checked_mul(h).ok_or(Error::Truncated)?)?;
-        for row in 0..h {
-            let n = *counts.get(c * h + row).ok_or(Error::Truncated)?;
-            unpack_bits(r.bytes(n)?, rowb, &mut out)?;
-        }
-        Ok(out)
-    }
-
-    /// Plane `c` of the inflated ZIP data of consecutive planes, un-predicted in place (`comp` 3).
-    fn zip_plane<'v>(&self, comp: u16, v: &'v mut [u8], c: usize, w: usize, h: usize) -> Result<&'v [u8]> {
-        let rowb = self.row_bytes(w);
-        let plane = v.get_mut(c * rowb * h..(c + 1) * rowb * h).ok_or(Error::Truncated)?;
-        if comp == 3 {
-            self.unpredict(plane, w, h);
-        }
-        Ok(plane)
-    }
-
-    /// One channel as `w * h` floats (0..1), charged to `budget` (the caller releases it).
-    fn channel_floats(&self, offset: usize, len: usize, w: usize, h: usize, budget: &mut Budget) -> Result<Vec<f32>> {
-        let raw = self.channel_bytes(offset, len, w, h, budget)?;
-        let mut out = budget.filled(decode_pixels(w, h)?, 0.0f32)?;
-        self.for_each_sample(&raw, w, h, |i, v| {
-            if let Some(o) = out.get_mut(i) {
-                *o = v;
-            }
-        });
-        release_bytes(budget, raw);
-        Ok(out)
-    }
-
-    fn row_bytes(&self, w: usize) -> usize {
-        if self.depth == 1 { w.div_ceil(8) } else { w * self.bytes_per_sample() }
-    }
-
-    fn unpredict(&self, v: &mut [u8], w: usize, h: usize) {
-        match self.depth {
-            16 => {
-                for row in v.chunks_exact_mut(w * 2).take(h) {
-                    let mut prev = 0u16;
-                    for c in row.as_chunks_mut::<2>().0 {
-                        let x = u16::from_be_bytes([c[0], c[1]]).wrapping_add(prev);
-                        c.copy_from_slice(&x.to_be_bytes());
-                        prev = x;
-                    }
-                }
-            }
-            32 => {
-                // One scratch row for the whole plane.
-                let mut planar = vec![0u8; w * 4];
-                #[cfg(test)]
-                counters::bump(&counters::SCRATCH);
-                for row in v.chunks_exact_mut(w * 4).take(h) {
-                    for i in 1..row.len() {
-                        row[i] = row[i].wrapping_add(row[i - 1]);
-                    }
-                    // Bytes are stored plane by plane (all first bytes, then all second bytes…).
-                    planar.copy_from_slice(row);
-                    for x in 0..w {
-                        for b in 0..4 {
-                            row[x * 4 + b] = planar[b * w + x];
-                        }
-                    }
-                }
-            }
-            _ => {
-                for row in v.chunks_exact_mut(w).take(h) {
-                    for i in 1..row.len() {
-                        row[i] = row[i].wrapping_add(row[i - 1]);
-                    }
-                }
-            }
-        }
-    }
-
-    /// Hand every sample of `raw` (`w`×`h`, row-major, in order) to `f` as a float. Samples a short
-    /// `raw` does not have are not reported.
-    fn for_each_sample(&self, raw: &[u8], w: usize, h: usize, mut f: impl FnMut(usize, f32)) {
-        let n = w.saturating_mul(h);
-        match self.depth {
-            1 => {
-                let rowb = w.div_ceil(8);
-                for y in 0..h {
-                    for x in 0..w {
-                        let b = raw.get(y * rowb + x / 8).copied().unwrap_or(0);
-                        // 1 = black.
-                        f(y * w + x, if b & (0x80 >> (x % 8)) != 0 { 0.0 } else { 1.0 });
-                    }
-                }
-            }
-            16 => raw.as_chunks::<2>().0.iter().take(n).enumerate().for_each(|(i, c)| f(i, u16::from_be_bytes([c[0], c[1]]) as f32 / 65535.0)),
-            // NaN reads as 0, +inf as white (1.0, like the integer depths' maximum), -inf as 0.
-            32 => raw.as_chunks::<4>().0.iter().take(n).enumerate().for_each(|(i, c)| f(i, finite_sample(f32::from_be_bytes([c[0], c[1], c[2], c[3]])))),
-            _ => raw.iter().take(n).enumerate().for_each(|(i, &b)| f(i, b as f32 / 255.0)),
-        }
-    }
-
-    /// Convert colour values (the document mode's channels, missing ones 0) to RGB.
-    fn rgb_from(&self, v: [f32; 4]) -> [f32; 3] {
-        let g = |k: usize| v.get(k).copied().unwrap_or(0.0);
-        let rgb = match self.mode {
-            ColorMode::Rgb => [g(0), g(1), g(2)],
-            ColorMode::Cmyk => {
-                // Stored inverted (1 = no ink).
-                let k = g(3);
-                [g(0) * k, g(1) * k, g(2) * k]
-            }
-            ColorMode::Indexed if self.palette.len() >= 768 => {
-                let idx = (g(0) * 255.0).round() as usize & 255;
-                [self.palette[idx] as f32 / 255.0, self.palette[256 + idx] as f32 / 255.0, self.palette[512 + idx] as f32 / 255.0]
-            }
-            ColorMode::Lab => lab_to_rgb(g(0) * 100.0, g(1) * 255.0 - 128.0, g(2) * 255.0 - 128.0),
-            _ => [g(0); 3],
-        };
-        if self.depth == 32 && self.mode != ColorMode::Lab { rgb.map(srgb_encode) } else { rgb }
-    }
-
-    /// Write merged-image channel `c` (raw bytes) into the result: the first three colour channels
-    /// and the alpha channel into their slot of a pixel, the fourth CMYK channel into `black`.
-    fn store_merged_channel(&self, c: usize, raw: &[u8], data: &mut [[f32; 4]], black: &mut Option<Vec<f32>>) {
-        let (w, h, cc) = (self.width as usize, self.height as usize, self.mode.color_channels());
-        if c < cc.min(3) {
-            self.for_each_sample(raw, w, h, |i, v| {
-                if let Some(p) = data.get_mut(i) {
-                    p[c] = v;
-                }
-            });
-        } else if c == 3 && c < cc {
-            if let Some(k) = black {
-                self.for_each_sample(raw, w, h, |i, v| {
-                    if let Some(o) = k.get_mut(i) {
-                        *o = v;
-                    }
-                });
-            }
-        } else if c == cc && self.merged_alpha {
-            self.for_each_sample(raw, w, h, |i, v| {
-                if let Some(p) = data.get_mut(i) {
-                    p[3] = v;
-                }
-            });
-        }
-    }
-
-    /// The merged (flattened) image.
-    pub fn composite(&self) -> Result<Pixels> {
-        self.composite_with_budget(DECODE_BUDGET)
-    }
-
-    /// [`Self::composite`] with at most `limit` bytes live at once. The channels are written
-    /// straight into the result, so the peak is the result (16 bytes a pixel), the CMYK black
-    /// channel, and the one buffer a channel (or, for ZIP, all channels) decodes through.
-    pub(crate) fn composite_with_budget(&self, limit: u64) -> Result<Pixels> {
-        let mut budget = Budget::new(limit);
-        let (w, h) = (self.width as usize, self.height as usize);
-        let n = decode_pixels(w, h)?;
-        let mut r = Reader::at(&self.data, self.merged_offset);
-        let comp = r.u16()?;
-        let nch = self.channels as usize;
-        let cc = self.mode.color_channels();
-        let want = (cc + usize::from(self.merged_alpha)).min(nch);
-        let rowb = self.row_bytes(w);
-        let size = rowb.checked_mul(h).ok_or_else(|| too_large(w, h))?;
-        // The peak: the result, the CMYK black channel and what the channels decode through.
-        let black_bytes = if self.mode == ColorMode::Cmyk && want > 3 { 4 * n as u64 } else { 0 };
-        let transient = if matches!(comp, 2 | 3) { (size as u64).saturating_mul(want as u64) } else { size as u64 };
-        budget.check((16 * n as u64).saturating_add(black_bytes).saturating_add(transient))?;
-        // Opaque black until a channel says otherwise.
-        let mut data = budget.filled(n, [0.0f32, 0.0, 0.0, 1.0])?;
-        let mut black = if self.mode == ColorMode::Cmyk && want > 3 { Some(budget.filled(n, 0.0f32)?) } else { None };
-        let mut stream = self.open_planes(comp, &mut r, nch, want, w, h, &mut budget)?;
-        for c in 0..want {
-            let raw = self.decode_plane(comp, &mut stream, &mut r, c, w, h, &mut budget)?;
-            self.store_merged_channel(c, &raw, &mut data, &mut black);
-            release_bytes(&mut budget, raw);
-        }
-        for (i, p) in data.iter_mut().enumerate() {
-            let k = black.as_ref().and_then(|k| k.get(i)).copied().unwrap_or(0.0);
-            let [r, g, b] = self.rgb_from([p[0], p[1], p[2], k]);
-            *p = [r, g, b, p[3]];
-        }
-        Ok(Pixels { width: w as u32, height: h as u32, data })
-    }
-
-    /// One layer's pixels with its layer mask (and vector-less fill colour) applied to alpha.
-    /// `canvas`: document-sized with the layer in place; otherwise the layer's own bounds.
-    pub fn layer_pixels(&self, index: usize, canvas: bool) -> Result<Pixels> {
-        self.layer_pixels_with_budget(index, canvas, DECODE_BUDGET)
-    }
-
-    /// [`Self::layer_pixels`] with at most `limit` bytes live at once: the result (16 bytes a
-    /// pixel) with the channels written straight into it, the CMYK black channel, the one channel
-    /// being decoded, and the mask.
-    pub(crate) fn layer_pixels_with_budget(&self, index: usize, canvas: bool, limit: u64) -> Result<Pixels> {
-        let mut budget = Budget::new(limit);
-        let l = self.layers.get(index).ok_or_else(|| Error::Invalid(format!("no layer {index}")))?;
-        let doc = Rect { top: 0, left: 0, bottom: self.height as i32, right: self.width as i32 };
-        // Fill layers often have no pixel data: they cover the canvas (or the mask).
-        let fill_rect =
-            if l.fill.is_some() && !l.has_pixels() { l.mask.filter(|m| !m.rect.is_empty() && m.default_color == 0).map_or(doc, |m| m.rect) } else { l.rect };
-        let out_rect = if canvas {
-            doc
-        } else if fill_rect.is_empty() {
-            Rect { top: 0, left: 0, bottom: 1, right: 1 }
-        } else {
-            fill_rect
-        };
-        let (ow, oh) = (out_rect.width() as usize, out_rect.height() as usize);
-        let n = decode_pixels(ow, oh)?;
-        let src = fill_rect;
-        let (sw, sh) = (src.width() as usize, src.height() as usize);
-        // The peak: the result, then either the CMYK black channel with the channel being decoded,
-        // or the mask as floats with its bytes. Checked before anything is allocated.
-        let plane = |w: usize, h: usize| (self.row_bytes(w) as u64).saturating_mul(h as u64);
-        let mut pixels_peak = 0u64;
-        if l.has_pixels() && sw > 0 && sh > 0 {
-            pixels_peak = plane(sw, sh).saturating_add(if self.mode == ColorMode::Cmyk { 4 * n as u64 } else { 0 });
-        }
-        let mut mask_peak = 0u64;
-        if let Some(m) = l.mask.filter(|m| !m.disabled) {
-            let (mw, mh) = (m.rect.width() as usize, m.rect.height() as usize);
-            if mw > 0 && mh > 0 && l.channels.iter().any(|c| c.id == -2) {
-                mask_peak = plane(mw, mh).saturating_add((mw as u64).saturating_mul(mh as u64).saturating_mul(4));
-            }
-        }
-        budget.check((16 * n as u64).saturating_add(pixels_peak.max(mask_peak)))?;
-        let mut out = budget.filled(n, [0.0f32; 4])?;
-        if sw > 0 && sh > 0 {
-            // The source rows / columns that land inside the output (64-bit: file bounds can span
-            // the whole i32 range).
-            let span = |s0: i32, n: usize, o0: i32, on: usize| {
-                let off = i64::from(o0) - i64::from(s0);
-                let lo = off.clamp(0, n as i64);
-                let hi = (off + on as i64).clamp(lo, n as i64);
-                (lo as usize..hi as usize, off)
-            };
-            let (ys, oy) = span(src.top, sh, out_rect.top, oh);
-            let (xs, ox) = span(src.left, sw, out_rect.left, ow);
-            let dest = |y: usize, x: usize| (y as i64 - oy) as usize * ow + (x as i64 - ox) as usize;
-            let fill = l.fill.map(|c| c.map(|v| v as f32));
-            match fill {
-                Some(f) if !l.has_pixels() => {
-                    for y in ys {
-                        for x in xs.clone() {
-                            if let Some(p) = out.get_mut(dest(y, x)) {
-                                *p = [f[0], f[1], f[2], 1.0];
-                            }
-                        }
-                    }
-                }
-                _ => {
-                    // Opaque unless there is an alpha channel.
-                    for y in ys.clone() {
-                        for x in xs.clone() {
-                            if let Some(p) = out.get_mut(dest(y, x)) {
-                                p[3] = 1.0;
-                            }
-                        }
-                    }
-                    let cc = self.mode.color_channels();
-                    let mut black: Option<Vec<f32>> = None;
-                    if l.has_pixels() {
-                        for c in &l.channels {
-                            let slot = match c.id {
-                                -1 => 3,
-                                id if id >= 0 && (id as usize) < cc => id as usize,
-                                _ => continue,
-                            };
-                            let raw = self.channel_bytes(c.offset, c.len, sw, sh, &mut budget)?;
-                            // The fourth CMYK channel is the black plate, not a slot of the result.
-                            let to_black = c.id == 3;
-                            if to_black && black.is_none() {
-                                black = Some(budget.filled(out.len(), 0.0f32)?);
-                            }
-                            // Samples arrive in row-major order of the source.
-                            let (mut sy, mut sx) = (0usize, 0usize);
-                            self.for_each_sample(&raw, sw, sh, |_, v| {
-                                if ys.contains(&sy) && xs.contains(&sx) {
-                                    let d = dest(sy, sx);
-                                    if to_black {
-                                        if let Some(o) = black.as_mut().and_then(|k| k.get_mut(d)) {
-                                            *o = v;
-                                        }
-                                    } else if let Some(p) = out.get_mut(d) {
-                                        p[slot] = v;
-                                    }
-                                }
-                                sx += 1;
-                                if sx == sw {
-                                    sx = 0;
-                                    sy += 1;
-                                }
-                            });
-                            release_bytes(&mut budget, raw);
-                        }
-                    }
-                    for y in ys {
-                        for x in xs.clone() {
-                            let d = dest(y, x);
-                            let k = black.as_ref().and_then(|k| k.get(d)).copied().unwrap_or(0.0);
-                            if let Some(p) = out.get_mut(d) {
-                                let [r, g, b] = self.rgb_from([p[0], p[1], p[2], k]);
-                                *p = [r, g, b, p[3]];
-                            }
-                        }
-                    }
-                    if let Some(k) = black {
-                        budget.release(k.len() as u64 * 4);
-                    }
-                }
-            }
-        }
-        // Layer mask: multiplies alpha (also outside the mask rect, by its default colour).
-        if let Some(m) = l.mask.filter(|m| !m.disabled) {
-            let mc = l.channels.iter().find(|c| c.id == -2);
-            let (mw, mh) = (m.rect.width() as usize, m.rect.height() as usize);
-            let mask = match mc {
-                Some(c) if mw > 0 && mh > 0 => Some(self.channel_floats(c.offset, c.len, mw, mh, &mut budget)?),
-                _ => None,
-            };
-            let def = m.default_color as f32 / 255.0;
-            // The factor outside the mask rect, or everywhere when there is no mask data.
-            let outside = if m.inverted { 1.0 - def } else { def };
-            let scale = |px: &mut [[f32; 4]], v: f32| {
-                if v != 1.0 {
-                    for p in px {
-                        p[3] *= v;
-                    }
-                }
-            };
-            match &mask {
-                None => scale(&mut out, outside),
-                Some(mk) => {
-                    // The columns of the output that fall inside the mask rect (the same for every row).
-                    let lo = (i64::from(m.rect.left) - i64::from(out_rect.left)).clamp(0, ow as i64);
-                    let hi = (i64::from(m.rect.right) - i64::from(out_rect.left)).clamp(lo, ow as i64);
-                    let (lo, hi) = (lo as usize, hi as usize);
-                    for (y, row) in out.chunks_exact_mut(ow.max(1)).take(oh).enumerate() {
-                        let py = i64::from(out_rect.top) + y as i64;
-                        #[cfg(test)]
-                        counters::bump(&counters::INSIDE);
-                        if py < i64::from(m.rect.top) || py >= i64::from(m.rect.bottom) {
-                            scale(row, outside);
-                            continue;
-                        }
-                        let (left, rest) = row.split_at_mut(lo);
-                        let (mid, right) = rest.split_at_mut(hi - lo);
-                        scale(left, outside);
-                        scale(right, outside);
-                        // The mask row under `mid`: its first column is output column `lo`.
-                        let base = (py - i64::from(m.rect.top)) as usize * mw + (i64::from(out_rect.left) + lo as i64 - i64::from(m.rect.left)) as usize;
-                        for (i, p) in mid.iter_mut().enumerate() {
-                            let v = mk.get(base + i).copied().unwrap_or(def);
-                            p[3] *= if m.inverted { 1.0 - v } else { v };
-                        }
-                    }
-                }
-            }
-        }
-        Ok(Pixels { width: ow as u32, height: oh as u32, data: out })
-    }
-}
-
-/// The pixel data of a run of planes, as prepared by `Psd::open_planes`.
-enum PlaneStream {
-    Raw,
-    /// RLE row byte counts of every plane, plane after plane.
-    Rle(Vec<usize>),
-    /// The inflated ZIP data of all planes.
-    Zip(Vec<u8>),
-}
-
-/// The next additional-information block at `*pos` (signature `8BIM`/`8B64`, key, length):
-/// returns (key, data start, data end). Skips up to 3 padding bytes before a signature.
-fn next_block(data: &[u8], pos: &mut usize, end: usize, psb: bool) -> Option<([u8; 4], usize, usize)> {
-    let mut p = *pos;
-    for _ in 0..4 {
-        if p + 12 > end {
-            return None;
-        }
-        if &data[p..p + 4] == b"8BIM" || &data[p..p + 4] == b"8B64" {
-            break;
-        }
-        p += 1;
-    }
-    if p + 12 > end || !(&data[p..p + 4] == b"8BIM" || &data[p..p + 4] == b"8B64") {
-        return None;
-    }
-    let mut key = [0u8; 4];
-    key.copy_from_slice(&data[p + 4..p + 8]);
-    let wide =
-        psb && matches!(&key, b"LMsk" | b"Lr16" | b"Lr32" | b"Layr" | b"Mt16" | b"Mt32" | b"Mtrn" | b"Alph" | b"FMsk" | b"lnk2" | b"FEid" | b"FXid" | b"PxSD");
-    let mut r = Reader::at(&data[..end], p + 8);
-    let len = r.length(wide).ok()?;
-    let start = r.pos;
-    let stop = start.checked_add(len)?;
-    if stop > end {
-        return None;
-    }
-    *pos = stop;
-    Some((key, start, stop))
-}
-
-/// PackBits decoding of one row (appends exactly `row` bytes, zero-padded).
-fn unpack_bits(src: &[u8], row: usize, out: &mut Vec<u8>) -> Result<()> {
-    let start = out.len();
-    let mut i = 0;
-    while i < src.len() && out.len() - start < row {
-        let n = src[i] as i8;
-        i += 1;
-        if n >= 0 {
-            let k = n as usize + 1;
-            let s = src.get(i..i + k).ok_or(Error::Truncated)?;
-            out.extend_from_slice(s);
-            i += k;
-        } else if n != -128 {
-            let k = (1 - n as isize) as usize;
-            let v = *src.get(i).ok_or(Error::Truncated)?;
-            out.extend(std::iter::repeat_n(v, k));
-            i += 1;
-        }
-    }
-    out.resize(start + row, 0);
-    Ok(())
-}
-
-/// PackBits encoding of one row.
-pub(crate) fn pack_bits(src: &[u8]) -> Vec<u8> {
-    let mut out = vec![];
-    let mut i = 0;
-    while i < src.len() {
-        // run of identical bytes
-        let mut run = 1;
-        while i + run < src.len() && src[i + run] == src[i] && run < 128 {
-            run += 1;
-        }
-        if run >= 2 {
-            out.push((1 - run as isize) as i8 as u8);
-            out.push(src[i]);
-            i += run;
-            continue;
-        }
-        // literal run
-        let start = i;
-        let mut n = 0;
-        while i < src.len() && n < 128 {
-            if i + 1 < src.len() && src[i + 1] == src[i] {
-                break;
-            }
-            i += 1;
-            n += 1;
-        }
-        if n == 0 {
-            i += 1;
-            n = 1;
-        }
-        out.push((n - 1) as u8);
-        out.extend_from_slice(&src[start..start + n]);
-    }
-    out
-}
-
-fn srgb_encode(v: f32) -> f32 {
-    if v <= 0.003_130_8 { v * 12.92 } else { 1.055 * v.powf(1.0 / 2.4) - 0.055 }
-}
-
-/// CIE L*a*b* (D50) to sRGB (D65 via the Bradford-adapted matrix), clamped.
-fn lab_to_rgb(l: f32, a: f32, b: f32) -> [f32; 3] {
-    let fy = (l + 16.0) / 116.0;
-    let fx = fy + a / 500.0;
-    let fz = fy - b / 200.0;
-    let f = |t: f32| if t > 6.0 / 29.0 { t * t * t } else { 3.0 * (6.0f32 / 29.0).powi(2) * (t - 4.0 / 29.0) };
-    let (x, y, z) = (0.964_22 * f(fx), f(fy), 0.825_21 * f(fz));
-    // XYZ (D50) → linear sRGB.
-    let r = 3.133_856 * x - 1.616_867 * y - 0.490_615 * z;
-    let g = -0.978_768 * x + 1.916_142 * y + 0.033_454 * z;
-    let bb = 0.071_945 * x - 0.228_991 * y + 1.405_243 * z;
-    [r, g, bb].map(|v| srgb_encode(v.clamp(0.0, 1.0)))
-}
-
 #[cfg(test)]
 mod memory_tests;
 #[cfg(test)]
 mod tests;
-#[cfg(test)]
-mod tests_integration;
-#[cfg(test)]
-mod tests_opt;
 
 /// Test-only call counters (per thread), to prove what the optimised paths avoid doing.
 #[cfg(test)]
-pub(crate) mod counters {
-    use std::cell::Cell;
-    use std::thread::LocalKey;
-
-    thread_local! {
-        /// Scratch rows allocated by the 32-bit ZIP un-predictor.
-        pub static SCRATCH: Cell<usize> = const { Cell::new(0) };
-        /// `inside the mask rect` evaluations of the layer-mask loop.
-        pub static INSIDE: Cell<usize> = const { Cell::new(0) };
-        /// `square_to_quad` solves.
-        pub static QUAD: Cell<usize> = const { Cell::new(0) };
-    }
-
-    pub fn bump(c: &'static LocalKey<Cell<usize>>) {
-        c.with(|c| c.set(c.get() + 1));
-    }
-    /// Read and reset.
-    pub fn take(c: &'static LocalKey<Cell<usize>>) -> usize {
-        c.with(|c| c.replace(0))
-    }
-}
+pub(crate) mod counters;
diff --git a/crates/psd/src/limits.rs b/crates/psd/src/limits.rs
new file mode 100644
index 000000000..c1c23b390
--- /dev/null
+++ b/crates/psd/src/limits.rs
@@ -0,0 +1,133 @@
+use std::borrow::Cow;
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum Error {
+    NotPsd,
+    Truncated,
+    Unsupported(String),
+    Invalid(String),
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Error::NotPsd => write!(f, "not a Photoshop document"),
+            Error::Truncated => write!(f, "truncated Photoshop document"),
+            Error::Unsupported(s) => write!(f, "unsupported Photoshop feature: {s}"),
+            Error::Invalid(s) => write!(f, "invalid Photoshop document: {s}"),
+        }
+    }
+}
+
+impl std::error::Error for Error {}
+
+pub type Result<T> = std::result::Result<T, Error>;
+
+/// The most pixels one decoded image (the composite, a layer or a mask) may have: 2^28, e.g.
+/// 16 384 × 16 384, 4 GiB as float RGBA. Bounds read from a file are untrusted, so a few bytes
+/// can't make the reader allocate more than that.
+const MAX_DECODE_PIXELS: u64 = 1 << 28;
+
+/// `w × h` as a pixel count, or an error when it exceeds [`MAX_DECODE_PIXELS`].
+pub(crate) fn decode_pixels(w: usize, h: usize) -> Result<usize> {
+    match (w as u64).checked_mul(h as u64) {
+        Some(n) if n <= MAX_DECODE_PIXELS => Ok(n as usize),
+        _ => Err(Error::Unsupported(format!("{w}×{h} pixels is too large to decode"))),
+    }
+}
+
+pub(crate) fn too_large(w: usize, h: usize) -> Error {
+    Error::Unsupported(format!("{w}×{h} pixels is too large to decode"))
+}
+
+/// What one decode (the composite, or one layer) may hold in memory at once: 4 GiB, 1 GiB where
+/// pointers are 32 bits wide (WebAssembly). [`MAX_DECODE_PIXELS`] bounds one image; this bounds
+/// the sum of the buffers a decode keeps alive together.
+#[cfg(target_pointer_width = "32")]
+pub(crate) const DECODE_BUDGET: u64 = 1 << 30;
+
+#[cfg(not(target_pointer_width = "32"))]
+pub(crate) const DECODE_BUDGET: u64 = 4 << 30;
+
+/// The bytes the buffers of one decode hold right now, against a limit. A decode charges a buffer
+/// before it allocates it (and releases it when it drops it), so a file that would need more
+/// than the limit fails with an error instead of an out-of-memory abort.
+pub(crate) struct Budget {
+    limit: u64,
+    live: u64,
+}
+
+impl Budget {
+    pub(crate) fn new(limit: u64) -> Budget {
+        Budget { limit, live: 0 }
+    }
+
+    pub(crate) fn charge(&mut self, bytes: u64) -> Result<()> {
+        self.check(bytes)?;
+        self.live += bytes;
+        Ok(())
+    }
+
+    /// Whether `bytes` more would still fit, without taking them. A decode checks its whole
+    /// expected peak first, so one that cannot fit fails before it has allocated anything.
+    pub(crate) fn check(&self, bytes: u64) -> Result<()> {
+        match self.live.checked_add(bytes) {
+            Some(total) if total <= self.limit => Ok(()),
+            _ => {
+                const MIB: u64 = 1 << 20;
+                Err(Error::Unsupported(format!(
+                    "decoding needs {} MiB more with {} MiB in use, over the {} MiB memory budget",
+                    bytes / MIB,
+                    self.live / MIB,
+                    self.limit / MIB
+                )))
+            }
+        }
+    }
+
+    pub(crate) fn release(&mut self, bytes: u64) {
+        self.live = self.live.saturating_sub(bytes);
+    }
+
+    /// An empty vector with room for `n` items, charged.
+    pub(crate) fn vec<T>(&mut self, n: usize) -> Result<Vec<T>> {
+        self.charge((n as u64).saturating_mul(std::mem::size_of::<T>() as u64))?;
+        let mut v = Vec::new();
+        v.try_reserve_exact(n).map_err(|_| Error::Unsupported(format!("out of memory for {n} items")))?;
+        Ok(v)
+    }
+
+    /// `n` copies of `value`, charged.
+    pub(crate) fn filled<T: Clone>(&mut self, n: usize, value: T) -> Result<Vec<T>> {
+        let mut v = self.vec::<T>(n)?;
+        v.resize(n, value);
+        Ok(v)
+    }
+}
+
+/// Inflate a zlib stream to at most `limit` bytes.
+pub(crate) fn inflate(src: &[u8], limit: usize) -> Result<Vec<u8>> {
+    miniz_oxide::inflate::decompress_to_vec_zlib_with_limit(src, limit).map_err(|e| Error::Invalid(format!("zip: {e:?}")))
+}
+
+/// Give back what a channel buffer from `Psd::channel_bytes` / `Psd::decode_plane` was charged:
+/// a borrowed one (uncompressed data, or a plane of an inflated stream charged as a whole) was not.
+pub(crate) fn release_bytes(budget: &mut Budget, raw: Cow<'_, [u8]>) {
+    if let Cow::Owned(v) = raw {
+        budget.release(v.len() as u64);
+    }
+}
+
+/// A 32-bit float sample made safe to use: NaN reads as 0, +inf as white (1.0, like the integer
+/// depths' maximum), -inf as 0.
+pub(crate) fn finite_sample(v: f32) -> f32 {
+    if v.is_nan() {
+        0.0
+    } else if v == f32::INFINITY {
+        1.0
+    } else if v == f32::NEG_INFINITY {
+        0.0
+    } else {
+        v
+    }
+}
diff --git a/crates/psd/src/model.rs b/crates/psd/src/model.rs
new file mode 100644
index 000000000..729b9a3c4
--- /dev/null
+++ b/crates/psd/src/model.rs
@@ -0,0 +1,265 @@
+use super::{Descriptor, engine_data, placed};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum ColorMode {
+    Bitmap,
+    Grayscale,
+    Indexed,
+    Rgb,
+    Cmyk,
+    Multichannel,
+    Duotone,
+    Lab,
+}
+
+impl ColorMode {
+    pub fn from_u16(v: u16) -> Option<ColorMode> {
+        Some(match v {
+            0 => ColorMode::Bitmap,
+            1 => ColorMode::Grayscale,
+            2 => ColorMode::Indexed,
+            3 => ColorMode::Rgb,
+            4 => ColorMode::Cmyk,
+            7 => ColorMode::Multichannel,
+            8 => ColorMode::Duotone,
+            9 => ColorMode::Lab,
+            _ => return None,
+        })
+    }
+    pub fn to_u16(self) -> u16 {
+        match self {
+            ColorMode::Bitmap => 0,
+            ColorMode::Grayscale => 1,
+            ColorMode::Indexed => 2,
+            ColorMode::Rgb => 3,
+            ColorMode::Cmyk => 4,
+            ColorMode::Multichannel => 7,
+            ColorMode::Duotone => 8,
+            ColorMode::Lab => 9,
+        }
+    }
+    /// Number of colour channels (before alpha).
+    pub fn color_channels(self) -> usize {
+        match self {
+            ColorMode::Rgb | ColorMode::Lab => 3,
+            ColorMode::Cmyk => 4,
+            _ => 1,
+        }
+    }
+}
+
+/// A rectangle in document pixels (`right`/`bottom` exclusive).
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub struct Rect {
+    pub top: i32,
+    pub left: i32,
+    pub bottom: i32,
+    pub right: i32,
+}
+
+impl Rect {
+    pub fn new(left: i32, top: i32, width: i32, height: i32) -> Rect {
+        Rect { top, left, bottom: top.saturating_add(height), right: left.saturating_add(width) }
+    }
+    pub fn width(&self) -> u32 {
+        (i64::from(self.right) - i64::from(self.left)).clamp(0, i64::from(u32::MAX)) as u32
+    }
+    pub fn height(&self) -> u32 {
+        (i64::from(self.bottom) - i64::from(self.top)).clamp(0, i64::from(u32::MAX)) as u32
+    }
+    pub fn is_empty(&self) -> bool {
+        self.width() == 0 || self.height() == 0
+    }
+}
+
+/// One channel of a layer: id (0.. colour, -1 transparency, -2 layer mask, -3 real user mask) and
+/// where its data (compression + image data) sits in the file.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct ChannelInfo {
+    pub id: i16,
+    pub offset: usize,
+    pub len: usize,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct LayerMask {
+    pub rect: Rect,
+    /// Value outside the mask rectangle (0 or 255).
+    pub default_color: u8,
+    pub disabled: bool,
+    pub inverted: bool,
+}
+
+/// Layer kind from the section divider setting (`lsct`).
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub enum Section {
+    #[default]
+    Layer,
+    OpenFolder,
+    ClosedFolder,
+    /// The hidden "</Layer group>" record that closes a group (below its children).
+    Divider,
+}
+
+/// A type layer (`TySh`).
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct TextInfo {
+    /// Text with `\n` line breaks.
+    pub text: String,
+    /// Affine transform (xx, xy, yx, yy, tx, ty): the text origin sits at (tx, ty).
+    pub transform: [f64; 6],
+    pub style: engine_data::TextStyle,
+    /// Text bounds (left, top, right, bottom) relative to the origin, when stored.
+    pub bounds: Option<[f64; 4]>,
+}
+
+/// Adjustment layers (best effort).
+#[derive(Clone, Debug, PartialEq)]
+pub enum Adjustment {
+    Invert,
+    BrightnessContrast {
+        brightness: f64,
+        contrast: f64,
+        legacy: bool,
+    },
+    HueSaturation {
+        hue: f64,
+        saturation: f64,
+        lightness: f64,
+        colorize: bool,
+    },
+    Levels {
+        in_black: f64,
+        in_white: f64,
+        gamma: f64,
+        out_black: f64,
+        out_white: f64,
+    },
+    Exposure {
+        exposure: f64,
+        offset: f64,
+        gamma: f64,
+    },
+    /// Another adjustment (its tagged-block key, e.g. `curv`, `blnc`).
+    Other(String),
+}
+
+/// A vector mask path: sub-paths of (in tangent, vertex, out tangent) points in document pixels.
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct VectorMask {
+    pub inverted: bool,
+    pub disabled: bool,
+    pub subpaths: Vec<SubPath>,
+}
+
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct SubPath {
+    pub closed: bool,
+    /// Per knot: [control point preceding, anchor, control point leaving] as (x, y).
+    pub knots: Vec<[[f64; 2]; 3]>,
+}
+
+/// A placed layer (smart object): `SoLd` / `SoLE` (placed layer data) or the older `PlLd`.
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct SmartObject {
+    /// Unique id of the linked file ([`Psd::linked`]) the layer shows.
+    pub uuid: String,
+    /// Where the content's corners sit in document pixels: top-left, top-right, bottom-right,
+    /// bottom-left.
+    pub quad: [[f64; 2]; 4],
+    /// The content's size in pixels (`Sz  `), when recorded.
+    pub size: Option<[f64; 2]>,
+    /// The placed layer's warp (`warp`), when it has one ([`placed`]).
+    pub warp: Option<placed::Warp>,
+}
+
+impl SmartObject {
+    /// The quad as an affine placement of a `w`×`h` content rectangle: (centre, scale x, scale
+    /// y, rotation in degrees). Perspective and skew are dropped.
+    pub fn placement(&self, w: f64, h: f64) -> ([f64; 2], f64, f64, f64) {
+        let q = self.quad;
+        let centre = [(q[0][0] + q[1][0] + q[2][0] + q[3][0]) / 4.0, (q[0][1] + q[1][1] + q[2][1] + q[3][1]) / 4.0];
+        let top = [q[1][0] - q[0][0], q[1][1] - q[0][1]];
+        let left = [q[3][0] - q[0][0], q[3][1] - q[0][1]];
+        let sx = top[0].hypot(top[1]) / w.max(1e-9);
+        let sy = left[0].hypot(left[1]) / h.max(1e-9);
+        // Mirrored content (left edge turning the other way) keeps a negative y scale.
+        let cross = top[0] * left[1] - top[1] * left[0];
+        (centre, sx, if cross < 0.0 { -sy } else { sy }, top[1].atan2(top[0]).to_degrees())
+    }
+}
+
+/// A file embedded in (or linked from) the document: linked layer data (`lnk2`, `lnkD`,
+/// `lnk3`, `lnkE`).
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct LinkedFile {
+    pub uuid: String,
+    pub name: String,
+    /// File type code (`8BPS`, `PNGf`, `JPEG`…), may be blank.
+    pub file_type: String,
+    /// Embedded data (absent for externally linked files).
+    pub data: Option<std::ops::Range<usize>>,
+}
+
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct Layer {
+    /// Index in [`Psd::layers`] (file order: bottom of the stack first).
+    pub index: usize,
+    pub name: String,
+    pub id: Option<u32>,
+    pub rect: Rect,
+    /// Blend mode key (`norm`, `mul `, `pass`…).
+    pub blend: [u8; 4],
+    pub opacity: u8,
+    /// Fill opacity (`iOpa`), 255 when absent.
+    pub fill_opacity: u8,
+    /// Clipped to the layer below.
+    pub clipping: bool,
+    pub hidden: bool,
+    pub protect_transparency: bool,
+    pub section: Section,
+    pub channels: Vec<ChannelInfo>,
+    pub mask: Option<LayerMask>,
+    pub text: Option<TextInfo>,
+    pub adjustment: Option<Adjustment>,
+    /// Solid colour fill layer (`SoCo`), RGB 0..1.
+    pub fill: Option<[f64; 3]>,
+    /// Layer effects (`lfx2` descriptor).
+    pub effects: Option<Descriptor>,
+    pub vector_mask: Option<VectorMask>,
+    /// Smart object placement.
+    pub smart_object: Option<SmartObject>,
+    /// Keys of every additional-information block the layer carries.
+    pub keys: Vec<[u8; 4]>,
+}
+
+impl Layer {
+    pub fn is_group(&self) -> bool {
+        matches!(self.section, Section::OpenFolder | Section::ClosedFolder)
+    }
+    pub fn blend_key(&self) -> &str {
+        std::str::from_utf8(&self.blend).unwrap_or("norm")
+    }
+    pub fn has_pixels(&self) -> bool {
+        !self.rect.is_empty() && self.channels.iter().any(|c| c.id >= 0)
+    }
+}
+
+/// How deep groups nest in [`Psd::tree`]; deeper ones are flattened (a hostile file can nest
+/// thousands, and walking or dropping that tree would overflow the stack).
+pub const MAX_GROUP_DEPTH: usize = 64;
+
+/// The layer tree, top of the stack first.
+#[derive(Clone, Debug, PartialEq)]
+pub enum Node {
+    Layer(usize),
+    Group { layer: usize, children: Vec<Node> },
+}
+
+/// Decoded pixels: straight RGBA, row-major.
+#[derive(Clone, Debug, PartialEq)]
+pub struct Pixels {
+    pub width: u32,
+    pub height: u32,
+    pub data: Vec<[f32; 4]>,
+}
diff --git a/crates/psd/src/parse.rs b/crates/psd/src/parse.rs
new file mode 100644
index 000000000..d221b9044
--- /dev/null
+++ b/crates/psd/src/parse.rs
@@ -0,0 +1,514 @@
+use super::limits::{Error, Result};
+use super::model::{
+    Adjustment, ChannelInfo, ColorMode, Layer, LayerMask, LinkedFile, MAX_GROUP_DEPTH, Node, Rect, Section, SmartObject, SubPath, TextInfo, VectorMask,
+};
+use super::{Psd, Reader, descriptor, engine_data, placed};
+use std::sync::Arc;
+
+/// Whether `bytes` start like a Photoshop document.
+pub fn is_psd(bytes: &[u8]) -> bool {
+    bytes.len() >= 6 && &bytes[..4] == b"8BPS" && matches!(u16::from_be_bytes([bytes[4], bytes[5]]), 1 | 2)
+}
+
+impl Psd {
+    pub fn parse(data: impl Into<Arc<[u8]>>) -> Result<Psd> {
+        let data: Arc<[u8]> = data.into();
+        let mut r = Reader::new(&data);
+        if r.bytes(4).ok() != Some(b"8BPS") {
+            return Err(Error::NotPsd);
+        }
+        let version = r.u16()?;
+        let psb = match version {
+            1 => false,
+            2 => true,
+            _ => return Err(Error::NotPsd),
+        };
+        r.skip(6)?;
+        let channels = r.u16()?;
+        let height = r.u32()?;
+        let width = r.u32()?;
+        let depth = r.u16()?;
+        let mode_v = r.u16()?;
+        let mode = ColorMode::from_u16(mode_v).ok_or_else(|| Error::Unsupported(format!("colour mode {mode_v}")))?;
+        if !matches!(depth, 1 | 8 | 16 | 32) {
+            return Err(Error::Unsupported(format!("{depth}-bit")));
+        }
+        if width == 0 || height == 0 || width > 300_000 || height > 300_000 {
+            return Err(Error::Invalid(format!("size {width}x{height}")));
+        }
+        // Colour mode data.
+        let n = r.u32()? as usize;
+        let palette = r.bytes(n)?.to_vec();
+        // Image resources.
+        let n = r.u32()? as usize;
+        r.skip(n)?;
+        // Layer and mask information.
+        let mut psd = Psd {
+            psb,
+            width,
+            height,
+            channels,
+            depth,
+            mode,
+            layers: vec![],
+            merged_alpha: false,
+            palette,
+            linked: vec![],
+            warnings: vec![],
+            data: data.clone(),
+            merged_offset: 0,
+        };
+        let lm_len = r.length(psb)?;
+        let lm_end = r.pos.checked_add(lm_len).filter(|&e| e <= data.len()).ok_or(Error::Truncated)?;
+        if lm_len > 0 {
+            let li_len = r.length(psb)?;
+            let li_end = r.pos.checked_add(li_len).filter(|&e| e <= lm_end).ok_or(Error::Truncated)?;
+            if li_len > 0
+                && let Err(e) = psd.layer_info(&data, r.pos, li_end)
+            {
+                // A damaged layer section must not discard the document: keep the header and the
+                // merged image, drop the layers and say so. Without a merged image there is
+                // nothing to fall back to, so the original error stands.
+                if lm_end.checked_add(2).is_none_or(|n| n > data.len()) {
+                    return Err(e);
+                }
+                psd.layers.clear();
+                psd.warnings.push(format!("Layers could not be read ({e}); only the flattened image is available"));
+            }
+            r.pos = li_end;
+            if r.pos + 4 <= lm_end {
+                let g = r.u32()? as usize;
+                r.pos = (r.pos + g).min(lm_end);
+            }
+            // Global additional layer information (16/32-bit layer info lives here).
+            while let Some((key, start, end)) = next_block(&data, &mut r.pos, lm_end, psb) {
+                if matches!(&key, b"lnk2" | b"lnkD" | b"lnk3" | b"lnkE") {
+                    psd.linked_files(&data, start, end);
+                }
+                if matches!(&key, b"Lr16" | b"Lr32" | b"Layr") && psd.layers.is_empty() && end > start {
+                    // The block holds the layer info, normally without its length field; accept
+                    // both layouts.
+                    if psd.layer_info(&data, start, end).is_err() || psd.layers.is_empty() {
+                        psd.layers.clear();
+                        let skip = if psb { 8 } else { 4 };
+                        if start + skip < end && psd.layer_info(&data, start + skip, end).is_err() {
+                            psd.layers.clear();
+                        }
+                    }
+                }
+                r.pos = end;
+            }
+        }
+        if !psd.layers.is_empty() {
+            // A 16/32-bit layer block recovered the layers.
+            psd.warnings.clear();
+        }
+        psd.merged_offset = lm_end;
+        Ok(psd)
+    }
+
+    /// The embedded bytes of linked file `uuid`.
+    pub fn linked_data(&self, uuid: &str) -> Option<&[u8]> {
+        let f = self.linked.iter().find(|f| f.uuid == uuid)?;
+        self.data.get(f.data.clone()?)
+    }
+
+    /// Linked layer data records (spec: "Linked Layer"): length, kind (`liFD` embedded data,
+    /// `liFE` external file, `liFA` alias), version, unique id, original file name, type,
+    /// creator, data length, optional descriptors, then the data. A damaged record ends the list.
+    fn linked_files(&mut self, data: &[u8], start: usize, end: usize) {
+        let mut pos = start;
+        while pos + 8 <= end {
+            let mut r = Reader::at(&data[..end], pos);
+            let Ok(len) = r.u64() else { break };
+            let body = r.pos;
+            let Some(rec_end) = body.checked_add(len as usize).filter(|e| *e <= end) else { break };
+            let mut r = Reader::at(&data[..rec_end], body);
+            let rec = (|| -> Result<LinkedFile> {
+                let kind = r.tag()?;
+                let version = r.u32()?;
+                let n = r.u8()? as usize;
+                let uuid = String::from_utf8_lossy(r.bytes(n)?).into_owned();
+                let name = descriptor::read_unicode(&mut r)?;
+                let file_type = String::from_utf8_lossy(&r.tag()?).trim().to_string();
+                let _creator = r.tag()?;
+                let dlen = r.u64()? as usize;
+                if r.u8()? != 0 {
+                    let _v = r.u32()?;
+                    descriptor::read_descriptor(&mut r)?;
+                }
+                let mut out = LinkedFile { uuid, name, file_type, data: None };
+                match &kind {
+                    b"liFD" => {
+                        let s = r.pos;
+                        r.skip(dlen)?;
+                        out.data = Some(s..s + dlen);
+                    }
+                    b"liFE" => {
+                        let _v = r.u32()?;
+                        descriptor::read_descriptor(&mut r)?;
+                        if version > 3 {
+                            r.skip(4 + 4 + 8)?;
+                        }
+                        let _size = r.u64()?;
+                        if version > 2 && r.remaining() >= dlen && dlen > 0 {
+                            let s = r.pos;
+                            out.data = Some(s..s + dlen);
+                        }
+                    }
+                    _ => {}
+                }
+                Ok(out)
+            })();
+            match rec {
+                Ok(f) => self.linked.push(f),
+                Err(_) => break,
+            }
+            pos = rec_end.div_ceil(4) * 4;
+        }
+    }
+
+    fn layer_info(&mut self, data: &[u8], start: usize, end: usize) -> Result<()> {
+        let mut r = Reader::at(&data[..end], start);
+        let count = r.i16()?;
+        self.merged_alpha = count < 0;
+        let n = count.unsigned_abs() as usize;
+        let mut layers = Vec::with_capacity(n);
+        for i in 0..n {
+            layers.push(self.layer_record(&mut r, i)?);
+        }
+        // Channel image data follows in record order.
+        for l in &mut layers {
+            for c in &mut l.channels {
+                c.offset = r.pos;
+                r.skip(c.len)?;
+            }
+        }
+        self.layers = layers;
+        Ok(())
+    }
+
+    fn layer_record(&self, r: &mut Reader, index: usize) -> Result<Layer> {
+        let psb = self.psb;
+        let (top, left, bottom, right) = (r.i32()?, r.i32()?, r.i32()?, r.i32()?);
+        let nch = r.u16()? as usize;
+        if nch > 64 {
+            return Err(Error::Invalid("channel count".into()));
+        }
+        let mut channels = Vec::with_capacity(nch);
+        for _ in 0..nch {
+            let id = r.i16()?;
+            let len = r.length(psb)?;
+            channels.push(ChannelInfo { id, offset: 0, len });
+        }
+        if r.bytes(4)? != b"8BIM" {
+            return Err(Error::Invalid("layer record signature".into()));
+        }
+        let blend = r.tag()?;
+        let opacity = r.u8()?;
+        let clipping = r.u8()? != 0;
+        let flags = r.u8()?;
+        r.skip(1)?;
+        let extra = r.u32()? as usize;
+        let extra_end = r.pos.checked_add(extra).filter(|&e| e <= r.data.len()).ok_or(Error::Truncated)?;
+        let mut l = Layer {
+            index,
+            rect: Rect { top, left, bottom, right },
+            blend,
+            opacity,
+            fill_opacity: 255,
+            clipping,
+            hidden: flags & 2 != 0,
+            protect_transparency: flags & 1 != 0,
+            channels,
+            ..Default::default()
+        };
+        // Layer mask data.
+        let mlen = r.u32()? as usize;
+        let mstart = r.pos;
+        if mlen >= 18 {
+            let rect = Rect { top: r.i32()?, left: r.i32()?, bottom: r.i32()?, right: r.i32()? };
+            let default_color = r.u8()?;
+            let mflags = r.u8()?;
+            l.mask = Some(LayerMask { rect, default_color, disabled: mflags & 2 != 0, inverted: mflags & 4 != 0 });
+        }
+        r.pos = mstart + mlen;
+        // Blending ranges.
+        let blen = r.u32()? as usize;
+        r.skip(blen)?;
+        l.name = r.pascal(4)?;
+        let mut pos = r.pos;
+        let data = r.data;
+        while let Some((key, start, end)) = next_block(data, &mut pos, extra_end, psb) {
+            l.keys.push(key);
+            let block = &data[start..end];
+            // A malformed block only loses that block's information.
+            let _ = self.layer_block(&mut l, &key, block);
+            pos = end;
+        }
+        r.pos = extra_end;
+        Ok(l)
+    }
+
+    fn layer_block(&self, l: &mut Layer, key: &[u8; 4], b: &[u8]) -> Result<()> {
+        let mut r = Reader::new(b);
+        match key {
+            b"luni" => {
+                let name = descriptor::read_unicode(&mut r)?;
+                if !name.is_empty() {
+                    l.name = name;
+                }
+            }
+            b"lyid" => l.id = Some(r.u32()?),
+            b"iOpa" => l.fill_opacity = r.u8()?,
+            b"lsct" | b"lsdk" => {
+                l.section = match r.u32()? {
+                    1 => Section::OpenFolder,
+                    2 => Section::ClosedFolder,
+                    3 => Section::Divider,
+                    _ => Section::Layer,
+                };
+                if b.len() >= 12 && &b[4..8] == b"8BIM" {
+                    l.blend.copy_from_slice(&b[8..12]);
+                }
+            }
+            b"TySh" => {
+                let _ver = r.u16()?;
+                let mut t = [0.0; 6];
+                for v in &mut t {
+                    *v = r.f64()?;
+                }
+                // A transform with NaN/inf is unusable: fall back to the identity.
+                if t.iter().any(|v| !v.is_finite()) {
+                    t = [1.0, 0.0, 0.0, 1.0, 0.0, 0.0];
+                }
+                let _text_ver = r.u16()?;
+                let _desc_ver = r.u32()?;
+                let d = descriptor::read_descriptor(&mut r)?;
+                let text = d.text("Txt ").unwrap_or_default().replace("\r\n", "\n").replace('\r', "\n");
+                let text = text.strip_suffix('\n').map(str::to_string).unwrap_or(text);
+                let style = d.raw("EngineData").map(|e| engine_data::text_style(&engine_data::parse(e))).unwrap_or_default();
+                let bounds =
+                    d.obj("bounds").or_else(|| d.obj("boundingBox")).and_then(|o| Some([o.num("Left")?, o.num("Top ")?, o.num("Rght")?, o.num("Btom")?]));
+                l.text = Some(TextInfo { text, transform: t, style, bounds });
+            }
+            b"lfx2" => {
+                let _ver = r.u32()?;
+                let _dver = r.u32()?;
+                l.effects = Some(descriptor::read_descriptor(&mut r)?);
+            }
+            b"SoCo" => {
+                let _ver = r.u32()?;
+                let d = descriptor::read_descriptor(&mut r)?;
+                l.fill = d.color("Clr ");
+            }
+            b"nvrt" => l.adjustment = Some(Adjustment::Invert),
+            b"brit" => {
+                let brightness = r.i16()? as f64;
+                let contrast = r.i16()? as f64;
+                if l.adjustment.is_none() {
+                    l.adjustment = Some(Adjustment::BrightnessContrast { brightness, contrast, legacy: true });
+                }
+            }
+            b"CgEd" => {
+                let _ver = r.u32()?;
+                let d = descriptor::read_descriptor(&mut r)?;
+                l.adjustment = Some(Adjustment::BrightnessContrast {
+                    brightness: d.num("Brgh").unwrap_or(0.0),
+                    contrast: d.num("Cntr").unwrap_or(0.0),
+                    legacy: d.bool("useLegacy").unwrap_or(false),
+                });
+            }
+            b"hue2" | b"hue " => {
+                let _ver = r.u16()?;
+                let colorize = r.u8()? != 0;
+                r.skip(1)?;
+                let ch = (r.i16()? as f64, r.i16()? as f64, r.i16()? as f64);
+                let m = (r.i16()? as f64, r.i16()? as f64, r.i16()? as f64);
+                let (hue, saturation, lightness) = if colorize { ch } else { m };
+                l.adjustment = Some(Adjustment::HueSaturation { hue, saturation, lightness, colorize });
+            }
+            b"levl" => {
+                let _ver = r.u16()?;
+                let (ib, iw, ob, ow, g) = (r.i16()?, r.i16()?, r.i16()?, r.i16()?, r.i16()?);
+                l.adjustment =
+                    Some(Adjustment::Levels { in_black: ib as f64, in_white: iw as f64, gamma: g as f64 / 100.0, out_black: ob as f64, out_white: ow as f64 });
+            }
+            b"expA" => {
+                let _ver = r.u16()?;
+                let mut finite = |default: f64| -> Result<f64> {
+                    let v = f64::from(r.f32()?);
+                    Ok(if v.is_finite() { v } else { default })
+                };
+                let exposure = finite(0.0)?;
+                let offset = finite(0.0)?;
+                let gamma = finite(1.0)?;
+                l.adjustment = Some(Adjustment::Exposure { exposure, offset, gamma });
+            }
+            b"curv" | b"blnc" | b"post" | b"thrs" | b"selc" | b"mixr" | b"phfl" | b"vibA" | b"blwh" | b"grdm" | b"clrL" if l.adjustment.is_none() => {
+                l.adjustment = Some(Adjustment::Other(String::from_utf8_lossy(key).into_owned()));
+            }
+            b"SoLd" | b"SoLE" => {
+                let _id = r.tag()?;
+                let _ver = r.u32()?;
+                let _dver = r.u32()?;
+                let d = descriptor::read_descriptor(&mut r)?;
+                let uuid = d.text("Idnt").unwrap_or_default().to_string();
+                let t = placed::eight(&d, "Trnf").unwrap_or([0.0; 8]);
+                // The non-affine transform when present (perspective), else the transform.
+                let t = placed::eight(&d, "nonAffineTransform").unwrap_or(t);
+                let size = d.obj("Sz  ").and_then(|s| Some([s.num("Wdth")?, s.num("Hght")?]));
+                let warp = d.obj("warp").and_then(placed::Warp::read);
+                l.smart_object = Some(SmartObject { uuid, quad: placed::quad_from(t), size, warp });
+            }
+            b"PlLd" if l.smart_object.is_none() => {
+                let _id = r.tag()?;
+                let _ver = r.u32()?;
+                let n = r.u8()? as usize;
+                let uuid = String::from_utf8_lossy(r.bytes(n)?).into_owned();
+                let _page = r.u32()?;
+                let _pages = r.u32()?;
+                let _aa = r.u32()?;
+                let _ty = r.u32()?;
+                let mut t = [0.0; 8];
+                for v in &mut t {
+                    *v = r.f64_finite()?;
+                }
+                l.smart_object = Some(SmartObject { uuid, quad: placed::quad_from(t), size: None, warp: None });
+            }
+            b"vmsk" | b"vsms" => {
+                let _ver = r.u32()?;
+                let flags = r.u32()?;
+                l.vector_mask = Some(self.vector_paths(&mut r, flags)?);
+            }
+            _ => {}
+        }
+        Ok(())
+    }
+
+    fn vector_paths(&self, r: &mut Reader, flags: u32) -> Result<VectorMask> {
+        let (w, h) = (self.width as f64, self.height as f64);
+        let mut vm = VectorMask { inverted: flags & 1 != 0, disabled: flags & 4 != 0, subpaths: vec![] };
+        let fixed = |r: &mut Reader| -> Result<f64> { Ok(r.i32()? as f64 / (1 << 24) as f64) };
+        while r.remaining() >= 26 {
+            let sel = r.u16()?;
+            match sel {
+                0 | 3 => {
+                    let _n = r.u16()?;
+                    r.skip(22)?;
+                    vm.subpaths.push(SubPath { closed: sel == 0, knots: vec![] });
+                }
+                1 | 2 | 4 | 5 => {
+                    let mut pts = [[0.0; 2]; 3];
+                    for p in &mut pts {
+                        let y = fixed(r)?;
+                        let x = fixed(r)?;
+                        *p = [x * w, y * h];
+                    }
+                    if let Some(sp) = vm.subpaths.last_mut() {
+                        sp.knots.push(pts);
+                    }
+                }
+                _ => r.skip(24)?,
+            }
+        }
+        vm.subpaths.retain(|s| !s.knots.is_empty());
+        Ok(vm)
+    }
+
+    /// The layer tree, top of the stack first. Groups nest at most [`MAX_GROUP_DEPTH`] deep (see
+    /// [`Psd::tree_report`]).
+    pub fn tree(&self) -> Vec<Node> {
+        self.tree_report().0
+    }
+
+    /// The layer tree plus the number of groups nested deeper than [`MAX_GROUP_DEPTH`]. Those
+    /// are flattened into their deepest allowed ancestor: their children stay, in order, and
+    /// the group record itself becomes a plain [`Node::Layer`], so no layer is lost and the
+    /// tree (and its `Drop`, `Clone` and `PartialEq`) cannot recurse deeper than the limit.
+    pub fn tree_report(&self) -> (Vec<Node>, usize) {
+        let mut stack: Vec<Vec<Node>> = vec![vec![]];
+        // Dividers seen while `MAX_GROUP_DEPTH` groups were already open.
+        let mut flattened_open = 0usize;
+        let mut flattened = 0usize;
+        for l in &self.layers {
+            match l.section {
+                Section::Divider => {
+                    if stack.len() > MAX_GROUP_DEPTH {
+                        flattened_open += 1;
+                    } else {
+                        stack.push(vec![]);
+                    }
+                }
+                Section::OpenFolder | Section::ClosedFolder => {
+                    if flattened_open > 0 {
+                        flattened_open -= 1;
+                        flattened += 1;
+                        if let Some(top) = stack.last_mut() {
+                            top.push(Node::Layer(l.index));
+                        }
+                        continue;
+                    }
+                    let children = if stack.len() > 1 { stack.pop().unwrap_or_default() } else { vec![] };
+                    if let Some(top) = stack.last_mut() {
+                        top.push(Node::Group { layer: l.index, children });
+                    }
+                }
+                Section::Layer => {
+                    if let Some(top) = stack.last_mut() {
+                        top.push(Node::Layer(l.index));
+                    }
+                }
+            }
+        }
+        while stack.len() > 1 {
+            let c = stack.pop().unwrap_or_default();
+            if let Some(top) = stack.last_mut() {
+                top.extend(c);
+            }
+        }
+        // Depth is at most `MAX_GROUP_DEPTH`, so recursion is bounded.
+        fn rev(v: &mut Vec<Node>) {
+            v.reverse();
+            for n in v {
+                if let Node::Group { children, .. } = n {
+                    rev(children);
+                }
+            }
+        }
+        let mut out = stack.pop().unwrap_or_default();
+        rev(&mut out);
+        (out, flattened)
+    }
+}
+
+/// The next additional-information block at `*pos` (signature `8BIM`/`8B64`, key, length):
+/// returns (key, data start, data end). Skips up to 3 padding bytes before a signature.
+fn next_block(data: &[u8], pos: &mut usize, end: usize, psb: bool) -> Option<([u8; 4], usize, usize)> {
+    let mut p = *pos;
+    for _ in 0..4 {
+        if p + 12 > end {
+            return None;
+        }
+        if &data[p..p + 4] == b"8BIM" || &data[p..p + 4] == b"8B64" {
+            break;
+        }
+        p += 1;
+    }
+    if p + 12 > end || !(&data[p..p + 4] == b"8BIM" || &data[p..p + 4] == b"8B64") {
+        return None;
+    }
+    let mut key = [0u8; 4];
+    key.copy_from_slice(&data[p + 4..p + 8]);
+    let wide =
+        psb && matches!(&key, b"LMsk" | b"Lr16" | b"Lr32" | b"Layr" | b"Mt16" | b"Mt32" | b"Mtrn" | b"Alph" | b"FMsk" | b"lnk2" | b"FEid" | b"FXid" | b"PxSD");
+    let mut r = Reader::at(&data[..end], p + 8);
+    let len = r.length(wide).ok()?;
+    let start = r.pos;
+    let stop = start.checked_add(len)?;
+    if stop > end {
+        return None;
+    }
+    *pos = stop;
+    Some((key, start, stop))
+}
diff --git a/crates/psd/src/pixels.rs b/crates/psd/src/pixels.rs
new file mode 100644
index 000000000..21a5c8845
--- /dev/null
+++ b/crates/psd/src/pixels.rs
@@ -0,0 +1,554 @@
+#[cfg(test)]
+use super::counters;
+use super::limits::{Budget, DECODE_BUDGET, Error, Result, decode_pixels, finite_sample, inflate, release_bytes, too_large};
+use super::model::{ColorMode, Layer, Pixels, Rect};
+use super::{Psd, Reader};
+use std::borrow::Cow;
+
+impl Psd {
+    fn bytes_per_sample(&self) -> usize {
+        match self.depth {
+            16 => 2,
+            32 => 4,
+            _ => 1,
+        }
+    }
+
+    /// The raw big-endian bytes of one channel of `w`×`h` samples at `offset` (compression field
+    /// first): `row_bytes(w) × h` of them with the compression and the prediction undone.
+    /// Uncompressed data is borrowed from the file, not copied; any other buffer is charged to
+    /// `budget` and the caller releases it (see [`release_bytes`]) once it is dropped.
+    fn channel_bytes(&self, offset: usize, len: usize, w: usize, h: usize, budget: &mut Budget) -> Result<Cow<'_, [u8]>> {
+        let end = offset.checked_add(len).filter(|&e| e <= self.data.len()).ok_or(Error::Truncated)?;
+        let mut r = Reader::at(self.data.get(..end).ok_or(Error::Truncated)?, offset);
+        let comp = r.u16()?;
+        decode_pixels(w, h)?;
+        self.plane_bytes(comp, &mut r, w, h, budget)
+    }
+
+    /// The raw bytes (`row_bytes(w)` × `h`, ZIP prediction undone) of one channel whose pixel data
+    /// follows `r`'s position (after the compression field). Uncompressed data is borrowed, not
+    /// copied; the other buffers are charged to `budget`.
+    pub(crate) fn plane_bytes<'a>(&self, comp: u16, r: &mut Reader<'a>, w: usize, h: usize, budget: &mut Budget) -> Result<Cow<'a, [u8]>> {
+        let rowb = self.row_bytes(w);
+        let size = rowb.checked_mul(h).ok_or_else(|| too_large(w, h))?;
+        Ok(match self.open_planes(comp, r, 1, 1, (w, h), budget)? {
+            PlaneStream::Raw => Cow::Borrowed(r.bytes(size)?),
+            PlaneStream::Rle(counts) => Cow::Owned(Self::unpack_plane(&counts, 0, r, rowb, h, budget)?),
+            PlaneStream::Zip(mut v) => {
+                v.resize(size, 0);
+                self.zip_plane(comp, &mut v, 0, w, h)?;
+                Cow::Owned(v)
+            }
+        })
+    }
+
+    /// Prepare the pixel data at `r` (just after the compression field) of `total` planes of
+    /// `w`×`h` samples, of which the first `want` are decoded: the RLE row sizes of every plane,
+    /// or the inflated ZIP data, which holds all planes one after another (charged to `budget`
+    /// before it is inflated).
+    fn open_planes(&self, comp: u16, r: &mut Reader, total: usize, want: usize, size: (usize, usize), budget: &mut Budget) -> Result<PlaneStream> {
+        let (w, h) = size;
+        let size = self.row_bytes(w).checked_mul(h).ok_or_else(|| too_large(w, h))?;
+        Ok(match comp {
+            0 => PlaneStream::Raw,
+            1 => {
+                let n = total.saturating_mul(h);
+                let mut counts = Vec::with_capacity(n.min(r.remaining() / 2));
+                for _ in 0..n {
+                    counts.push(if self.psb { r.u32()? as usize } else { r.u16()? as usize });
+                }
+                PlaneStream::Rle(counts)
+            }
+            2 | 3 => {
+                let rest = r.bytes(r.remaining())?;
+                // One stream holds every plane: what it may decode to is what they need.
+                let all = size.checked_mul(want).ok_or_else(|| too_large(w, h))?;
+                budget.charge(all as u64)?;
+                PlaneStream::Zip(inflate(rest, all)?)
+            }
+            c => return Err(Error::Unsupported(format!("compression {c}"))),
+        })
+    }
+
+    /// The raw bytes (`row_bytes(w)` × `h`, ZIP prediction undone) of plane `c`: raw and RLE
+    /// planes are read from `r` in order, raw ones borrowed from the file data, ZIP ones from the
+    /// inflated buffer (un-predicted in place; already charged by `open_planes`), RLE ones charged
+    /// to `budget`.
+    fn decode_plane<'x, 'a: 'x>(
+        &self,
+        comp: u16,
+        planes: &'x mut PlaneStream,
+        r: &mut Reader<'a>,
+        c: usize,
+        size: (usize, usize),
+        budget: &mut Budget,
+    ) -> Result<Cow<'x, [u8]>> {
+        let (w, h) = size;
+        let rowb = self.row_bytes(w);
+        let size = rowb.checked_mul(h).ok_or_else(|| too_large(w, h))?;
+        Ok(match planes {
+            PlaneStream::Raw => Cow::Borrowed(r.bytes(size)?),
+            PlaneStream::Rle(counts) => Cow::Owned(Self::unpack_plane(counts, c, r, rowb, h, budget)?),
+            PlaneStream::Zip(v) => Cow::Borrowed(self.zip_plane(comp, v, c, w, h)?),
+        })
+    }
+
+    /// Unpack the `h` RLE rows of plane `c` (row byte counts `counts`, plane after plane) into a
+    /// buffer charged to `budget`.
+    fn unpack_plane(counts: &[usize], c: usize, r: &mut Reader, rowb: usize, h: usize, budget: &mut Budget) -> Result<Vec<u8>> {
+        let mut out = budget.vec::<u8>(rowb.checked_mul(h).ok_or(Error::Truncated)?)?;
+        for row in 0..h {
+            let n = *counts.get(c * h + row).ok_or(Error::Truncated)?;
+            unpack_bits(r.bytes(n)?, rowb, &mut out)?;
+        }
+        Ok(out)
+    }
+
+    /// Plane `c` of the inflated ZIP data of consecutive planes, un-predicted in place (`comp` 3).
+    pub(crate) fn zip_plane<'v>(&self, comp: u16, v: &'v mut [u8], c: usize, w: usize, h: usize) -> Result<&'v [u8]> {
+        let rowb = self.row_bytes(w);
+        let plane = v.get_mut(c * rowb * h..(c + 1) * rowb * h).ok_or(Error::Truncated)?;
+        if comp == 3 {
+            self.unpredict(plane, w, h);
+        }
+        Ok(plane)
+    }
+
+    /// One channel as `w * h` floats (0..1), charged to `budget` (the caller releases it).
+    fn channel_floats(&self, offset: usize, len: usize, w: usize, h: usize, budget: &mut Budget) -> Result<Vec<f32>> {
+        let raw = self.channel_bytes(offset, len, w, h, budget)?;
+        let mut out = budget.filled(decode_pixels(w, h)?, 0.0f32)?;
+        self.for_each_sample(&raw, w, h, |i, v| {
+            if let Some(o) = out.get_mut(i) {
+                *o = v;
+            }
+        });
+        release_bytes(budget, raw);
+        Ok(out)
+    }
+
+    pub(crate) fn row_bytes(&self, w: usize) -> usize {
+        if self.depth == 1 { w.div_ceil(8) } else { w * self.bytes_per_sample() }
+    }
+
+    pub(crate) fn unpredict(&self, v: &mut [u8], w: usize, h: usize) {
+        match self.depth {
+            16 => {
+                for row in v.chunks_exact_mut(w * 2).take(h) {
+                    let mut prev = 0u16;
+                    for c in row.as_chunks_mut::<2>().0 {
+                        let x = u16::from_be_bytes([c[0], c[1]]).wrapping_add(prev);
+                        c.copy_from_slice(&x.to_be_bytes());
+                        prev = x;
+                    }
+                }
+            }
+            32 => {
+                // One scratch row for the whole plane.
+                let mut planar = vec![0u8; w * 4];
+                #[cfg(test)]
+                counters::bump(&counters::SCRATCH);
+                for row in v.chunks_exact_mut(w * 4).take(h) {
+                    for i in 1..row.len() {
+                        row[i] = row[i].wrapping_add(row[i - 1]);
+                    }
+                    // Bytes are stored plane by plane (all first bytes, then all second bytes…).
+                    planar.copy_from_slice(row);
+                    for x in 0..w {
+                        for b in 0..4 {
+                            row[x * 4 + b] = planar[b * w + x];
+                        }
+                    }
+                }
+            }
+            _ => {
+                for row in v.chunks_exact_mut(w).take(h) {
+                    for i in 1..row.len() {
+                        row[i] = row[i].wrapping_add(row[i - 1]);
+                    }
+                }
+            }
+        }
+    }
+
+    /// Hand every sample of `raw` (`w`×`h`, row-major, in order) to `f` as a float. Samples a short
+    /// `raw` does not have are not reported.
+    pub(crate) fn for_each_sample(&self, raw: &[u8], w: usize, h: usize, mut f: impl FnMut(usize, f32)) {
+        let n = w.saturating_mul(h);
+        match self.depth {
+            1 => {
+                let rowb = w.div_ceil(8);
+                for y in 0..h {
+                    for x in 0..w {
+                        let b = raw.get(y * rowb + x / 8).copied().unwrap_or(0);
+                        // 1 = black.
+                        f(y * w + x, if b & (0x80 >> (x % 8)) != 0 { 0.0 } else { 1.0 });
+                    }
+                }
+            }
+            16 => raw.as_chunks::<2>().0.iter().take(n).enumerate().for_each(|(i, c)| f(i, u16::from_be_bytes([c[0], c[1]]) as f32 / 65535.0)),
+            // NaN reads as 0, +inf as white (1.0, like the integer depths' maximum), -inf as 0.
+            32 => raw.as_chunks::<4>().0.iter().take(n).enumerate().for_each(|(i, c)| f(i, finite_sample(f32::from_be_bytes([c[0], c[1], c[2], c[3]])))),
+            _ => raw.iter().take(n).enumerate().for_each(|(i, &b)| f(i, b as f32 / 255.0)),
+        }
+    }
+
+    /// Convert colour values (the document mode's channels, missing ones 0) to RGB.
+    pub(crate) fn rgb_from(&self, v: [f32; 4]) -> [f32; 3] {
+        let g = |k: usize| v.get(k).copied().unwrap_or(0.0);
+        let rgb = match self.mode {
+            ColorMode::Rgb => [g(0), g(1), g(2)],
+            ColorMode::Cmyk => {
+                // Stored inverted (1 = no ink).
+                let k = g(3);
+                [g(0) * k, g(1) * k, g(2) * k]
+            }
+            ColorMode::Indexed if self.palette.len() >= 768 => {
+                let idx = (g(0) * 255.0).round() as usize & 255;
+                [self.palette[idx] as f32 / 255.0, self.palette[256 + idx] as f32 / 255.0, self.palette[512 + idx] as f32 / 255.0]
+            }
+            ColorMode::Lab => lab_to_rgb(g(0) * 100.0, g(1) * 255.0 - 128.0, g(2) * 255.0 - 128.0),
+            _ => [g(0); 3],
+        };
+        if self.depth == 32 && self.mode != ColorMode::Lab { rgb.map(srgb_encode) } else { rgb }
+    }
+
+    /// Write merged-image channel `c` (raw bytes) into the result: the first three colour channels
+    /// and the alpha channel into their slot of a pixel, the fourth CMYK channel into `black`.
+    fn store_merged_channel(&self, c: usize, raw: &[u8], data: &mut [[f32; 4]], black: &mut Option<Vec<f32>>) {
+        let (w, h, cc) = (self.width as usize, self.height as usize, self.mode.color_channels());
+        if c < cc.min(3) {
+            self.for_each_sample(raw, w, h, |i, v| {
+                if let Some(p) = data.get_mut(i) {
+                    p[c] = v;
+                }
+            });
+        } else if c == 3 && c < cc {
+            if let Some(k) = black {
+                self.for_each_sample(raw, w, h, |i, v| {
+                    if let Some(o) = k.get_mut(i) {
+                        *o = v;
+                    }
+                });
+            }
+        } else if c == cc && self.merged_alpha {
+            self.for_each_sample(raw, w, h, |i, v| {
+                if let Some(p) = data.get_mut(i) {
+                    p[3] = v;
+                }
+            });
+        }
+    }
+
+    /// The merged (flattened) image.
+    pub fn composite(&self) -> Result<Pixels> {
+        self.composite_with_budget(DECODE_BUDGET)
+    }
+
+    /// [`Self::composite`] with at most `limit` bytes live at once. The channels are written
+    /// straight into the result, so the peak is the result (16 bytes a pixel), the CMYK black
+    /// channel, and the one buffer a channel (or, for ZIP, all channels) decodes through.
+    pub(crate) fn composite_with_budget(&self, limit: u64) -> Result<Pixels> {
+        let mut budget = Budget::new(limit);
+        let (w, h) = (self.width as usize, self.height as usize);
+        let n = decode_pixels(w, h)?;
+        let mut r = Reader::at(&self.data, self.merged_offset);
+        let comp = r.u16()?;
+        let nch = self.channels as usize;
+        let cc = self.mode.color_channels();
+        let want = (cc + usize::from(self.merged_alpha)).min(nch);
+        let rowb = self.row_bytes(w);
+        let size = rowb.checked_mul(h).ok_or_else(|| too_large(w, h))?;
+        // The peak: the result, the CMYK black channel and what the channels decode through.
+        let black_bytes = if self.mode == ColorMode::Cmyk && want > 3 { 4 * n as u64 } else { 0 };
+        let transient = if matches!(comp, 2 | 3) { (size as u64).saturating_mul(want as u64) } else { size as u64 };
+        budget.check((16 * n as u64).saturating_add(black_bytes).saturating_add(transient))?;
+        // Opaque black until a channel says otherwise.
+        let mut data = budget.filled(n, [0.0f32, 0.0, 0.0, 1.0])?;
+        let mut black = if self.mode == ColorMode::Cmyk && want > 3 { Some(budget.filled(n, 0.0f32)?) } else { None };
+        let mut stream = self.open_planes(comp, &mut r, nch, want, (w, h), &mut budget)?;
+        for c in 0..want {
+            let raw = self.decode_plane(comp, &mut stream, &mut r, c, (w, h), &mut budget)?;
+            self.store_merged_channel(c, &raw, &mut data, &mut black);
+            release_bytes(&mut budget, raw);
+        }
+        for (i, p) in data.iter_mut().enumerate() {
+            let k = black.as_ref().and_then(|k| k.get(i)).copied().unwrap_or(0.0);
+            let [r, g, b] = self.rgb_from([p[0], p[1], p[2], k]);
+            *p = [r, g, b, p[3]];
+        }
+        Ok(Pixels { width: w as u32, height: h as u32, data })
+    }
+
+    /// One layer's pixels with its layer mask (and vector-less fill colour) applied to alpha.
+    /// `canvas`: document-sized with the layer in place; otherwise the layer's own bounds.
+    pub fn layer_pixels(&self, index: usize, canvas: bool) -> Result<Pixels> {
+        self.layer_pixels_with_budget(index, canvas, DECODE_BUDGET)
+    }
+
+    /// [`Self::layer_pixels`] with at most `limit` bytes live at once: the result (16 bytes a
+    /// pixel) with the channels written straight into it, the CMYK black channel, the one channel
+    /// being decoded, and the mask.
+    pub(crate) fn layer_pixels_with_budget(&self, index: usize, canvas: bool, limit: u64) -> Result<Pixels> {
+        let mut budget = Budget::new(limit);
+        let l = self.layers.get(index).ok_or_else(|| Error::Invalid(format!("no layer {index}")))?;
+        let doc = Rect { top: 0, left: 0, bottom: self.height as i32, right: self.width as i32 };
+        // Fill layers often have no pixel data: they cover the canvas (or the mask).
+        let fill_rect =
+            if l.fill.is_some() && !l.has_pixels() { l.mask.filter(|m| !m.rect.is_empty() && m.default_color == 0).map_or(doc, |m| m.rect) } else { l.rect };
+        let out_rect = if canvas {
+            doc
+        } else if fill_rect.is_empty() {
+            Rect { top: 0, left: 0, bottom: 1, right: 1 }
+        } else {
+            fill_rect
+        };
+        let (ow, oh) = (out_rect.width() as usize, out_rect.height() as usize);
+        let n = decode_pixels(ow, oh)?;
+        let src = fill_rect;
+        let (sw, sh) = (src.width() as usize, src.height() as usize);
+        // The peak: the result, then either the CMYK black channel with the channel being decoded,
+        // or the mask as floats with its bytes. Checked before anything is allocated.
+        let plane = |w: usize, h: usize| (self.row_bytes(w) as u64).saturating_mul(h as u64);
+        let mut pixels_peak = 0u64;
+        if l.has_pixels() && sw > 0 && sh > 0 {
+            pixels_peak = plane(sw, sh).saturating_add(if self.mode == ColorMode::Cmyk { 4 * n as u64 } else { 0 });
+        }
+        let mut mask_peak = 0u64;
+        if let Some(m) = l.mask.filter(|m| !m.disabled) {
+            let (mw, mh) = (m.rect.width() as usize, m.rect.height() as usize);
+            if mw > 0 && mh > 0 && l.channels.iter().any(|c| c.id == -2) {
+                mask_peak = plane(mw, mh).saturating_add((mw as u64).saturating_mul(mh as u64).saturating_mul(4));
+            }
+        }
+        budget.check((16 * n as u64).saturating_add(pixels_peak.max(mask_peak)))?;
+        let mut out = budget.filled(n, [0.0f32; 4])?;
+        if sw > 0 && sh > 0 {
+            // The source rows / columns that land inside the output (64-bit: file bounds can span
+            // the whole i32 range).
+            let span = |s0: i32, n: usize, o0: i32, on: usize| {
+                let off = i64::from(o0) - i64::from(s0);
+                let lo = off.clamp(0, n as i64);
+                let hi = (off + on as i64).clamp(lo, n as i64);
+                (lo as usize..hi as usize, off)
+            };
+            let (ys, oy) = span(src.top, sh, out_rect.top, oh);
+            let (xs, ox) = span(src.left, sw, out_rect.left, ow);
+            let dest = |y: usize, x: usize| (y as i64 - oy) as usize * ow + (x as i64 - ox) as usize;
+            let fill = l.fill.map(|c| c.map(|v| v as f32));
+            match fill {
+                Some(f) if !l.has_pixels() => {
+                    for y in ys {
+                        for x in xs.clone() {
+                            if let Some(p) = out.get_mut(dest(y, x)) {
+                                *p = [f[0], f[1], f[2], 1.0];
+                            }
+                        }
+                    }
+                }
+                _ => {
+                    // Opaque unless there is an alpha channel.
+                    for y in ys.clone() {
+                        for x in xs.clone() {
+                            if let Some(p) = out.get_mut(dest(y, x)) {
+                                p[3] = 1.0;
+                            }
+                        }
+                    }
+                    let cc = self.mode.color_channels();
+                    let mut black: Option<Vec<f32>> = None;
+                    if l.has_pixels() {
+                        for c in &l.channels {
+                            let slot = match c.id {
+                                -1 => 3,
+                                id if id >= 0 && (id as usize) < cc => id as usize,
+                                _ => continue,
+                            };
+                            let raw = self.channel_bytes(c.offset, c.len, sw, sh, &mut budget)?;
+                            // The fourth CMYK channel is the black plate, not a slot of the result.
+                            let to_black = c.id == 3;
+                            if to_black && black.is_none() {
+                                black = Some(budget.filled(out.len(), 0.0f32)?);
+                            }
+                            // Samples arrive in row-major order of the source.
+                            let (mut sy, mut sx) = (0usize, 0usize);
+                            self.for_each_sample(&raw, sw, sh, |_, v| {
+                                if ys.contains(&sy) && xs.contains(&sx) {
+                                    let d = dest(sy, sx);
+                                    if to_black {
+                                        if let Some(o) = black.as_mut().and_then(|k| k.get_mut(d)) {
+                                            *o = v;
+                                        }
+                                    } else if let Some(p) = out.get_mut(d) {
+                                        p[slot] = v;
+                                    }
+                                }
+                                sx += 1;
+                                if sx == sw {
+                                    sx = 0;
+                                    sy += 1;
+                                }
+                            });
+                            release_bytes(&mut budget, raw);
+                        }
+                    }
+                    for y in ys {
+                        for x in xs.clone() {
+                            let d = dest(y, x);
+                            let k = black.as_ref().and_then(|k| k.get(d)).copied().unwrap_or(0.0);
+                            if let Some(p) = out.get_mut(d) {
+                                let [r, g, b] = self.rgb_from([p[0], p[1], p[2], k]);
+                                *p = [r, g, b, p[3]];
+                            }
+                        }
+                    }
+                    if let Some(k) = black {
+                        budget.release(k.len() as u64 * 4);
+                    }
+                }
+            }
+        }
+        self.apply_layer_mask(l, out_rect, &mut out, &mut budget)?;
+        Ok(Pixels { width: ow as u32, height: oh as u32, data: out })
+    }
+
+    /// Apply the raster mask to alpha, including its default outside the mask bounds.
+    fn apply_layer_mask(&self, l: &Layer, out_rect: Rect, out: &mut [[f32; 4]], budget: &mut Budget) -> Result<()> {
+        let (ow, oh) = (out_rect.width() as usize, out_rect.height() as usize);
+        // Layer mask: multiplies alpha (also outside the mask rect, by its default colour).
+        if let Some(m) = l.mask.filter(|m| !m.disabled) {
+            let mc = l.channels.iter().find(|c| c.id == -2);
+            let (mw, mh) = (m.rect.width() as usize, m.rect.height() as usize);
+            let mask = match mc {
+                Some(c) if mw > 0 && mh > 0 => Some(self.channel_floats(c.offset, c.len, mw, mh, budget)?),
+                _ => None,
+            };
+            let def = m.default_color as f32 / 255.0;
+            // The factor outside the mask rect, or everywhere when there is no mask data.
+            let outside = if m.inverted { 1.0 - def } else { def };
+            let scale = |px: &mut [[f32; 4]], v: f32| {
+                if v != 1.0 {
+                    for p in px {
+                        p[3] *= v;
+                    }
+                }
+            };
+            match &mask {
+                None => scale(out, outside),
+                Some(mk) => {
+                    // The columns of the output that fall inside the mask rect (the same for every row).
+                    let lo = (i64::from(m.rect.left) - i64::from(out_rect.left)).clamp(0, ow as i64);
+                    let hi = (i64::from(m.rect.right) - i64::from(out_rect.left)).clamp(lo, ow as i64);
+                    let (lo, hi) = (lo as usize, hi as usize);
+                    for (y, row) in out.chunks_exact_mut(ow.max(1)).take(oh).enumerate() {
+                        let py = i64::from(out_rect.top) + y as i64;
+                        #[cfg(test)]
+                        counters::bump(&counters::INSIDE);
+                        if py < i64::from(m.rect.top) || py >= i64::from(m.rect.bottom) {
+                            scale(row, outside);
+                            continue;
+                        }
+                        let (left, rest) = row.split_at_mut(lo);
+                        let (mid, right) = rest.split_at_mut(hi - lo);
+                        scale(left, outside);
+                        scale(right, outside);
+                        // The mask row under `mid`: its first column is output column `lo`.
+                        let base = (py - i64::from(m.rect.top)) as usize * mw + (i64::from(out_rect.left) + lo as i64 - i64::from(m.rect.left)) as usize;
+                        for (i, p) in mid.iter_mut().enumerate() {
+                            let v = mk.get(base + i).copied().unwrap_or(def);
+                            p[3] *= if m.inverted { 1.0 - v } else { v };
+                        }
+                    }
+                }
+            }
+        }
+        Ok(())
+    }
+}
+
+/// The pixel data of a run of planes, as prepared by `Psd::open_planes`.
+enum PlaneStream {
+    Raw,
+    /// RLE row byte counts of every plane, plane after plane.
+    Rle(Vec<usize>),
+    /// The inflated ZIP data of all planes.
+    Zip(Vec<u8>),
+}
+
+/// PackBits decoding of one row (appends exactly `row` bytes, zero-padded).
+pub(crate) fn unpack_bits(src: &[u8], row: usize, out: &mut Vec<u8>) -> Result<()> {
+    let start = out.len();
+    let mut i = 0;
+    while i < src.len() && out.len() - start < row {
+        let n = src[i] as i8;
+        i += 1;
+        if n >= 0 {
+            let k = n as usize + 1;
+            let s = src.get(i..i + k).ok_or(Error::Truncated)?;
+            out.extend_from_slice(s);
+            i += k;
+        } else if n != -128 {
+            let k = (1 - n as isize) as usize;
+            let v = *src.get(i).ok_or(Error::Truncated)?;
+            out.extend(std::iter::repeat_n(v, k));
+            i += 1;
+        }
+    }
+    out.resize(start + row, 0);
+    Ok(())
+}
+
+/// PackBits encoding of one row.
+pub(crate) fn pack_bits(src: &[u8]) -> Vec<u8> {
+    let mut out = vec![];
+    let mut i = 0;
+    while i < src.len() {
+        // run of identical bytes
+        let mut run = 1;
+        while i + run < src.len() && src[i + run] == src[i] && run < 128 {
+            run += 1;
+        }
+        if run >= 2 {
+            out.push((1 - run as isize) as i8 as u8);
+            out.push(src[i]);
+            i += run;
+            continue;
+        }
+        // literal run
+        let start = i;
+        let mut n = 0;
+        while i < src.len() && n < 128 {
+            if i + 1 < src.len() && src[i + 1] == src[i] {
+                break;
+            }
+            i += 1;
+            n += 1;
+        }
+        if n == 0 {
+            i += 1;
+            n = 1;
+        }
+        out.push((n - 1) as u8);
+        out.extend_from_slice(&src[start..start + n]);
+    }
+    out
+}
+
+pub(crate) fn srgb_encode(v: f32) -> f32 {
+    if v <= 0.003_130_8 { v * 12.92 } else { 1.055 * v.powf(1.0 / 2.4) - 0.055 }
+}
+
+/// CIE L*a*b* (D50) to sRGB (D65 via the Bradford-adapted matrix), clamped.
+pub(crate) fn lab_to_rgb(l: f32, a: f32, b: f32) -> [f32; 3] {
+    let fy = (l + 16.0) / 116.0;
+    let fx = fy + a / 500.0;
+    let fz = fy - b / 200.0;
+    let f = |t: f32| if t > 6.0 / 29.0 { t * t * t } else { 3.0 * (6.0f32 / 29.0).powi(2) * (t - 4.0 / 29.0) };
+    let (x, y, z) = (0.964_22 * f(fx), f(fy), 0.825_21 * f(fz));
+    // XYZ (D50) → linear sRGB.
+    let r = 3.133_856 * x - 1.616_867 * y - 0.490_615 * z;
+    let g = -0.978_768 * x + 1.916_142 * y + 0.033_454 * z;
+    let bb = 0.071_945 * x - 0.228_991 * y + 1.405_243 * z;
+    [r, g, bb].map(|v| srgb_encode(v.clamp(0.0, 1.0)))
+}
diff --git a/crates/psd/src/tests.rs b/crates/psd/src/tests.rs
index 60283b229..074976510 100644
--- a/crates/psd/src/tests.rs
+++ b/crates/psd/src/tests.rs
@@ -1,6 +1,9 @@
 use super::write::*;
 use super::*;
 
+mod integration;
+mod opt;
+
 fn gradient(w: u32, h: u32) -> Vec<[f32; 4]> {
     (0..w * h).map(|i| [(i % w) as f32 / (w - 1).max(1) as f32, (i / w) as f32 / (h - 1).max(1) as f32, 0.25, 1.0]).collect()
 }
diff --git a/crates/psd/src/tests_integration.rs b/crates/psd/src/tests/integration.rs
similarity index 98%
rename from crates/psd/src/tests_integration.rs
rename to crates/psd/src/tests/integration.rs
index a2b48b20c..ee40aee16 100644
--- a/crates/psd/src/tests_integration.rs
+++ b/crates/psd/src/tests/integration.rs
@@ -2,9 +2,9 @@
 //! the limit, a NaN text transform), a damaged layer section, and a tiny file claiming a huge
 //! image. Each ends in a clean result or a clean error, on a 2 MiB stack, never a panic.
 
-use super::memory_tests::with_merged;
-use super::write::*;
-use super::*;
+use crate::memory_tests::with_merged;
+use crate::write::*;
+use crate::*;
 
 /// Run `f` on a 2 MiB thread; a panic or stack overflow in it fails the test.
 fn on_small_stack<T: Send + 'static>(f: impl FnOnce() -> T + Send + 'static) -> T {
diff --git a/crates/psd/src/tests_opt.rs b/crates/psd/src/tests/opt.rs
similarity index 99%
rename from crates/psd/src/tests_opt.rs
rename to crates/psd/src/tests/opt.rs
index f129480c1..908026d07 100644
--- a/crates/psd/src/tests_opt.rs
+++ b/crates/psd/src/tests/opt.rs
@@ -1,10 +1,12 @@
 //! The optimised decode / mask / placed-bake paths against the implementations they replaced
 //! (kept below verbatim as references), and counters for the work they no longer do.
 
-use super::counters::{self, INSIDE, QUAD, SCRATCH};
-use super::placed::{Warp, square_to_quad};
-use super::write::*;
-use super::*;
+use std::borrow::Cow;
+
+use crate::counters::{self, INSIDE, QUAD, SCRATCH};
+use crate::placed::{Warp, square_to_quad};
+use crate::write::*;
+use crate::*;
 
 // ------------------------------------------------------------------ the replaced code
 
diff --git a/crates/raster/src/blur.rs b/crates/raster/src/blur.rs
index 46b749a9a..c8689a7b6 100644
--- a/crates/raster/src/blur.rs
+++ b/crates/raster/src/blur.rs
@@ -247,7 +247,9 @@ pub fn radial_blur(img: &Image, center: (f64, f64), amount: f64, zoom: bool) ->
                     let (s, c) = (t * amount).to_radians().sin_cos();
                     (center.0 + vx * c - vy * s, center.1 + vx * s + vy * c)
                 };
-                let p = img.sample_bilinear(sx, sy);
+                // Samples outside the image repeat its edge: After Effects' Radial Blur keeps a
+                // layer's edges (cases 713, 829) instead of fading them toward transparency.
+                let p = img.sample_bilinear(sx.clamp(0.5, (img.width as f64 - 0.5).max(0.5)), sy.clamp(0.5, (img.height as f64 - 0.5).max(0.5)));
                 for ch in 0..4 {
                     acc[ch] += p[ch];
                 }
diff --git a/crates/raster/src/inpaint.rs b/crates/raster/src/inpaint.rs
index 15bdaa0dd..c64de3375 100644
--- a/crates/raster/src/inpaint.rs
+++ b/crates/raster/src/inpaint.rs
@@ -607,38 +607,44 @@ pub struct FillInput {
     pub references: Vec<(usize, Image)>,
 }
 
-/// Trace pixel (x, y) of frame `t` through `flows` (`step` = +1 forward with `fwd`, −1 backward
-/// with `bwd`) to the nearest frame where it is visible: (sampled colour, frames travelled).
-fn trace(
-    t: usize,
+/// Shared frame and flow data for tracing pixels through a sequence.
+struct TraceContext<'a> {
+    fwd: &'a [Flow],
+    bwd: &'a [Flow],
+    known: &'a (dyn Fn(usize, i64, i64) -> bool + Sync),
+    frames: &'a [&'a Image],
+    max: usize,
+}
+
+/// Starting frame, point, and direction for a flow trace.
+struct TraceStart {
+    frame: usize,
     x: f64,
     y: f64,
     step: i64,
-    fwd: &[Flow],
-    bwd: &[Flow],
-    known: &dyn Fn(usize, i64, i64) -> bool,
-    frames: &[&Image],
-    max: usize,
-) -> Option<([f32; 4], usize)> {
-    let n = frames.len();
-    let (w, h) = (frames[0].width as f64, frames[0].height as f64);
-    let (mut px, mut py) = (x, y);
-    let mut k = t as i64;
-    for d in 1..=max {
-        let v = if step > 0 {
+}
+
+/// Trace a point to the nearest visible frame: (sampled colour, frames travelled).
+fn trace(context: &TraceContext<'_>, start: TraceStart) -> Option<([f32; 4], usize)> {
+    let n = context.frames.len();
+    let (w, h) = (context.frames[0].width as f64, context.frames[0].height as f64);
+    let (mut px, mut py) = (start.x, start.y);
+    let mut k = start.frame as i64;
+    for d in 1..=context.max {
+        let v = if start.step > 0 {
             if k as usize + 1 >= n {
                 return None;
             }
-            fwd[k as usize].at(px, py)
+            context.fwd[k as usize].at(px, py)
         } else {
             if k == 0 {
                 return None;
             }
-            bwd[k as usize - 1].at(px, py)
+            context.bwd[k as usize - 1].at(px, py)
         };
         px += v[0] as f64;
         py += v[1] as f64;
-        k += step;
+        k += start.step;
         if px < 0.0 || py < 0.0 || px >= w || py >= h {
             return None;
         }
@@ -646,9 +652,9 @@ fn trace(
         let (x0, y0) = ((px - 0.5).floor() as i64, (py - 0.5).floor() as i64);
         let ok = [(x0, y0), (x0 + 1, y0), (x0, y0 + 1), (x0 + 1, y0 + 1)]
             .iter()
-            .all(|&(xx, yy)| known(k as usize, xx.clamp(0, w as i64 - 1), yy.clamp(0, h as i64 - 1)));
+            .all(|&(xx, yy)| (context.known)(k as usize, xx.clamp(0, w as i64 - 1), yy.clamp(0, h as i64 - 1)));
         if ok {
-            return Some((frames[k as usize].sample_bilinear_clamped(px, py), d));
+            return Some((context.frames[k as usize].sample_bilinear_clamped(px, py), d));
         }
     }
     None
@@ -697,6 +703,7 @@ pub fn fill_sequence(input: &FillInput, o: &FillOpts, progress: &mut dyn FnMut(u
     // 2. Propagation (and the lighting-correction border ring).
     let refs: Vec<&Image> = frames.iter().collect();
     let known = |k: usize, x: i64, y: i64| !holes[k][y as usize * w + x as usize];
+    let trace_context = TraceContext { fwd: &fwd, bwd: &bwd, known: &known, frames: &refs, max: n };
     let ring_r = 2usize;
     let propagated: Vec<(Image, Vec<bool>)> = (0..n)
         .into_par_iter()
@@ -708,8 +715,8 @@ pub fn fill_sequence(input: &FillInput, o: &FillOpts, progress: &mut dyn FnMut(u
             }
             let sample = |i: usize| -> Option<[f32; 4]> {
                 let (x, y) = ((i % w) as f64 + 0.5, (i / w) as f64 + 0.5);
-                let f = trace(t, x, y, 1, &fwd, &bwd, &known, &refs, n);
-                let b = trace(t, x, y, -1, &fwd, &bwd, &known, &refs, n);
+                let f = trace(&trace_context, TraceStart { frame: t, x, y, step: 1 });
+                let b = trace(&trace_context, TraceStart { frame: t, x, y, step: -1 });
                 match (f, b) {
                     (Some((a, da)), Some((c, dc))) => {
                         let (wa, wc) = (1.0 / da as f32, 1.0 / dc as f32);
diff --git a/crates/raster/src/lib.rs b/crates/raster/src/lib.rs
index dce8dda81..9f2e4e755 100644
--- a/crates/raster/src/lib.rs
+++ b/crates/raster/src/lib.rs
@@ -12,16 +12,39 @@ pub mod flow;
 pub mod inpaint;
 pub mod scopes;
 pub mod warp;
+pub mod yuv;
 
 use effectcraft_color::{BlendMode, blend_pixel};
 use rayon::prelude::*;
 
 pub use blur::{box_blur, directional_blur, gaussian_blur, gaussian_blur_exact, gaussian_is_exact, radial_blur};
 pub use channels3d::AuxChannels;
-pub use warp::{Sampling, WarpOpts, accumulate_warp, composite_warp, composite_warp_reference, resample};
+pub use warp::{Sampling, WarpOpts, accumulate_warp, composite_warp, composite_warp_changed, composite_warp_reference, resample};
 
 pub type Px = [f32; 4];
 
+/// Clamp (colour ≤ alpha ≤ 1, NaN → 0) and round half up to `levels` steps (`inv` = 1 / levels):
+/// one pixel of an 8/16 bpc buffer. Values are non-negative after the clamp, so the integer
+/// conversion rounds like `round()` and vectorises.
+#[allow(clippy::manual_clamp)] // max/min map NaN to 0; clamp would keep NaN
+#[inline(always)]
+pub fn quantize_px(p: &mut Px, levels: f32, inv: f32) {
+    let a = round_half_up(p[3].max(0.0).min(1.0) * levels) * inv;
+    let hi = [a, a, a, a];
+    for c in 0..3 {
+        p[c] = round_half_up(p[c].max(0.0).min(hi[c]) * levels) * inv;
+    }
+    p[3] = a;
+}
+
+/// `v` (0..=65 535) rounded half up. The same either way; the fastest on each target: x86-64's
+/// baseline converts to integers in one instruction but has no `floor` (SSE4.1), while in wasm
+/// `floor` is one instruction and converting back from `u32` several (about 1.5× faster there).
+#[inline(always)]
+fn round_half_up(v: f32) -> f32 {
+    if cfg!(target_arch = "wasm32") { (v + 0.5).floor() } else { (v + 0.5) as u32 as f32 }
+}
+
 #[derive(Clone, Debug, Default, PartialEq)]
 pub struct Image {
     pub width: u32,
@@ -199,26 +222,33 @@ impl Image {
     }
     /// Straight-alpha 8-bit RGBA (sRGB-encoded values as stored).
     pub fn to_rgba8(&self) -> Vec<u8> {
-        let mut out = vec![0u8; self.data.len() * 4];
-        out.par_chunks_mut(4).zip(self.data.par_iter()).for_each(|(o, p)| {
+        self.map_rgba8(|o, p| {
             let a = p[3].clamp(0.0, 1.0);
             let inv = if a > 0.0 { 1.0 / p[3] } else { 0.0 };
             for c in 0..3 {
                 o[c] = ((p[c] * inv).clamp(0.0, 1.0) * 255.0 + 0.5) as u8;
             }
             o[3] = (a * 255.0 + 0.5) as u8;
-        });
-        out
+        })
     }
     /// Composite over an opaque background colour and return opaque 8-bit RGBA.
     pub fn to_rgba8_over(&self, bg: [f32; 3]) -> Vec<u8> {
-        let mut out = vec![0u8; self.data.len() * 4];
-        out.par_chunks_mut(4).zip(self.data.par_iter()).for_each(|(o, p)| {
+        self.map_rgba8(|o, p| {
             let k = 1.0 - p[3].clamp(0.0, 1.0);
             for c in 0..3 {
                 o[c] = ((p[c] + bg[c] * k).clamp(0.0, 1.0) * 255.0 + 0.5) as u8;
             }
             o[3] = 255;
+        })
+    }
+    /// 8-bit RGBA with each pixel written by `f`, row-parallel.
+    fn map_rgba8(&self, f: impl Fn(&mut [u8; 4], &Px) + Sync) -> Vec<u8> {
+        let mut out = vec![0u8; self.data.len() * 4];
+        let w = self.width.max(1) as usize;
+        out.par_chunks_mut(w * 4).zip(self.data.par_chunks(w)).for_each(|(o, row)| {
+            for (o, p) in o.as_chunks_mut::<4>().0.iter_mut().zip(row) {
+                f(o, p);
+            }
         });
         out
     }
diff --git a/crates/raster/src/warp.rs b/crates/raster/src/warp.rs
index 8b45761e4..9f6de31ce 100644
--- a/crates/raster/src/warp.rs
+++ b/crates/raster/src/warp.rs
@@ -57,7 +57,15 @@ fn half(src: &Image) -> Image {
 /// bilinear without bounds checks, integer-translation copies, inlined Normal blending); it
 /// matches [`composite_warp_reference`] to float rounding.
 pub fn composite_warp(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts) {
-    composite_warp_impl(dst, src, m, opts, true, None);
+    composite_warp_impl(dst, src, m, opts, true, None, None);
+}
+
+/// [`composite_warp`], also returning the destination pixels it changed when it knows them:
+/// `Some([x0, y0, x1, y1])` (half-open, empty when nothing was drawn) on the fast affine path,
+/// `None` otherwise. With `quantize` (an 8/16 bpc destination's levels), the fast path also
+/// quantises each pixel it blends ([`crate::quantize_px`]): exactly when this returns `Some`.
+pub fn composite_warp_changed(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts, quantize: Option<f32>) -> Option<[u32; 4]> {
+    composite_warp_impl(dst, src, m, opts, true, None, quantize)
 }
 
 /// `dst += warp(src) · weight` (plain sum, no blending): motion-blur sub-samples accumulate
@@ -65,7 +73,7 @@ pub fn composite_warp(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts) {
 pub fn accumulate_warp(dst: &mut Image, src: &Image, m: &Mat3, sampling: Sampling, weight: f32) {
     let opts = WarpOpts { sampling, ..Default::default() };
     if m.is_affine() && m.inverse().is_some_and(|i| i.is_affine()) {
-        composite_warp_impl(dst, src, m, &opts, true, Some(weight));
+        composite_warp_impl(dst, src, m, &opts, true, Some(weight), None);
         return;
     }
     let mut tmp = Image::new(dst.width, dst.height);
@@ -79,7 +87,7 @@ pub fn accumulate_warp(dst: &mut Image, src: &Image, m: &Mat3, sampling: Samplin
 
 /// The straightforward per-pixel implementation (reference for the fast path's tests).
 pub fn composite_warp_reference(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts) {
-    composite_warp_impl(dst, src, m, opts, false, None);
+    composite_warp_impl(dst, src, m, opts, false, None, None);
 }
 
 /// Bilinear blend of four taps (same operation order as [`Image::sample_bilinear`]).
@@ -94,9 +102,49 @@ fn bilerp(a: Px, b: Px, c: Px, d: Px, tx: f32, ty: f32) -> Px {
     o
 }
 
-/// Bilinear sample with an unchecked interior fast path.
+/// Side of the square source tiles of [`ClearTiles`].
+const TILE: usize = 16;
+
+/// Which `TILE`×`TILE` source tiles are fully transparent, the one-pixel apron to their right
+/// and below included: the four taps of a bilinear sample whose top-left tap lies in such a
+/// tile all have zero alpha, so the sample is transparent and draws nothing.
+struct ClearTiles {
+    cols: usize,
+    clear: Vec<bool>,
+}
+
+impl ClearTiles {
+    fn new(img: &Image) -> ClearTiles {
+        let (w, h) = (img.width as usize, img.height as usize);
+        let (cols, rows) = (w.div_ceil(TILE), h.div_ceil(TILE));
+        let clear = (0..rows)
+            .into_par_iter()
+            .flat_map_iter(|ty| {
+                let mut row_clear = vec![true; cols];
+                for y in ty * TILE..(ty * TILE + TILE + 1).min(h) {
+                    let row = &img.data[y * w..(y + 1) * w];
+                    for (tx, c) in row_clear.iter_mut().enumerate() {
+                        if *c {
+                            *c = row[tx * TILE..(tx * TILE + TILE + 1).min(w)].iter().all(|p| p[3] == 0.0);
+                        }
+                    }
+                }
+                row_clear
+            })
+            .collect();
+        ClearTiles { cols, clear }
+    }
+
+    #[inline(always)]
+    fn is_clear(&self, x: usize, y: usize) -> bool {
+        self.clear.get((y / TILE) * self.cols + x / TILE).copied().unwrap_or(false)
+    }
+}
+
+/// Bilinear sample with an unchecked interior fast path; `None` when every interior tap is in a
+/// [`ClearTiles`] tile (the sample would have zero alpha).
 #[inline(always)]
-fn sample_bilinear_fast(img: &Image, x: f64, y: f64) -> Px {
+fn sample_bilinear_fast(img: &Image, clear: &ClearTiles, x: f64, y: f64) -> Option<Px> {
     let fx = x - 0.5;
     let fy = y - 0.5;
     let x0 = fx.floor();
@@ -104,14 +152,17 @@ fn sample_bilinear_fast(img: &Image, x: f64, y: f64) -> Px {
     let (xi, yi) = (x0 as i64, y0 as i64);
     let (w, h) = (img.width as i64, img.height as i64);
     if xi >= 0 && yi >= 0 && xi + 1 < w && yi + 1 < h {
+        if clear.is_clear(xi as usize, yi as usize) {
+            return None;
+        }
         let tx = (fx - x0) as f32;
         let ty = (fy - y0) as f32;
         let i = yi as usize * w as usize + xi as usize;
         let row0 = &img.data[i..i + 2];
         let row1 = &img.data[i + w as usize..i + w as usize + 2];
-        return bilerp(row0[0], row0[1], row1[0], row1[1], tx, ty);
+        return Some(bilerp(row0[0], row0[1], row1[0], row1[1], tx, ty));
     }
-    img.sample_bilinear(x, y)
+    Some(img.sample_bilinear(x, y))
 }
 
 /// Index range `[lo, hi)` of `i` in `0..n` for which `p0 + i·s` may lie in `[min, max]`
@@ -127,20 +178,43 @@ fn span(p0: f64, s: f64, min: f64, max: f64, n: usize) -> (usize, usize) {
     if hi <= lo { (0, 0) } else { (lo as usize, hi as usize) }
 }
 
-/// Fast affine rows: `blend(dst, src, x, y)` is only called for visible source pixels.
-#[allow(clippy::too_many_arguments)]
-fn affine_rows(
-    dst: &mut Image,
-    img: &Image,
-    inv: &Mat3,
+/// Columns `[a, b)` of one destination row that a warp changed (`a == b`: none).
+#[derive(Clone, Copy)]
+struct RowSpan {
+    a: usize,
+    b: usize,
+}
+
+impl RowSpan {
+    const NONE: RowSpan = RowSpan { a: usize::MAX, b: 0 };
+    #[inline(always)]
+    fn add(&mut self, x: usize) {
+        self.a = self.a.min(x);
+        self.b = x + 1;
+    }
+}
+
+/// Union of changed pixels as `[x0, y0, x1, y1]` (half-open; `x0 >= x1` when empty).
+fn union(r: [usize; 4], q: [usize; 4]) -> [usize; 4] {
+    match (r[0] < r[2], q[0] < q[2]) {
+        (false, _) => q,
+        (_, false) => r,
+        _ => [r[0].min(q[0]), r[1].min(q[1]), r[2].max(q[2]), r[3].max(q[3])],
+    }
+}
+
+/// Sampling, blending and destination bounds for an affine row operation.
+struct AffineRows {
     sampling: Sampling,
-    op: f32,
-    x0: usize,
-    x1: usize,
-    y0: usize,
-    y1: usize,
-    blend: impl Fn(Px, Px, u32, u32) -> Px + Sync,
-) {
+    opacity: f32,
+    quantize: Option<f32>,
+    bounds: [usize; 4],
+}
+
+/// Blend visible source samples and return the rectangle of changed pixels.
+fn affine_rows(dst: &mut Image, img: &Image, inv: &Mat3, rows: AffineRows, blend: impl Fn(Px, Px, u32, u32) -> Px + Sync) -> [usize; 4] {
+    let AffineRows { sampling, opacity: op, quantize, bounds: [x0, x1, y0, y1] } = rows;
+    let levels = quantize.map(|l| (l, 1.0 / l));
     let w = dst.width as usize;
     let m = inv.0;
     let (iw, ih) = (img.width as f64, img.height as f64);
@@ -148,71 +222,104 @@ fn affine_rows(
     // Pure integer translation: every sample lands on a pixel centre, so all filters return the
     // source pixel itself (bicubic still clamps negatives, as in the reference).
     let int_tx = m[0][0] == 1.0 && m[1][1] == 1.0 && m[0][1] == 0.0 && m[1][0] == 0.0 && m[0][2].fract() == 0.0 && m[1][2].fract() == 0.0;
-    dst.data.par_chunks_mut(w).enumerate().skip(y0).take(y1 - y0).for_each(|(y, row)| {
-        let fy = y as f64 + 0.5;
-        let p0 = vec2(m[0][0] * (x0 as f64 + 0.5) + m[0][1] * fy + m[0][2], m[1][0] * (x0 as f64 + 0.5) + m[1][1] * fy + m[1][2]);
-        let n = x1 - x0;
-        let (ax, bx) = span(p0.x, step.x, -1.0, iw + 1.0, n);
-        let (ay, by) = span(p0.y, step.y, -1.0, ih + 1.0, n);
-        let (lo, hi) = (ax.max(ay), bx.min(by));
-        if lo >= hi {
-            return;
-        }
-        if int_tx {
-            let sy = y as i64 + m[1][2] as i64;
-            if sy < 0 || sy >= img.height as i64 {
-                return;
+    // Bilinear samples skip the transparent parts of the source (most of a thin shape's or a
+    // glow-padded layer's buffer) without reading them.
+    let clear = (sampling == Sampling::Bilinear && !int_tx).then(|| ClearTiles::new(img));
+    let empty = [usize::MAX, usize::MAX, 0, 0];
+    dst.data
+        .par_chunks_mut(w)
+        .enumerate()
+        .skip(y0)
+        .take(y1 - y0)
+        .map(|(y, row)| {
+            let mut changed = RowSpan::NONE;
+            let fy = y as f64 + 0.5;
+            let p0 = vec2(m[0][0] * (x0 as f64 + 0.5) + m[0][1] * fy + m[0][2], m[1][0] * (x0 as f64 + 0.5) + m[1][1] * fy + m[1][2]);
+            let n = x1 - x0;
+            let (ax, bx) = span(p0.x, step.x, -1.0, iw + 1.0, n);
+            let (ay, by) = span(p0.y, step.y, -1.0, ih + 1.0, n);
+            let (lo, hi) = (ax.max(ay), bx.min(by));
+            if lo >= hi {
+                return empty;
             }
-            let dx = m[0][2] as i64;
-            let srow = &img.data[sy as usize * img.width as usize..(sy as usize + 1) * img.width as usize];
-            let xa = (x0 as i64 + lo as i64).max(-dx).max(0) as usize;
-            let xb = ((x0 + hi) as i64).min(img.width as i64 - dx).max(0) as usize;
-            for x in xa..xb.max(xa) {
-                let mut s = srow[(x as i64 + dx) as usize];
-                if sampling == Sampling::Bicubic {
-                    s = [s[0].max(0.0), s[1].max(0.0), s[2].max(0.0), s[3].max(0.0)];
+            if int_tx {
+                let sy = y as i64 + m[1][2] as i64;
+                if sy < 0 || sy >= img.height as i64 {
+                    return empty;
                 }
-                if s[3] <= 0.0 {
-                    continue;
-                }
-                if op < 1.0 {
-                    for c in s.iter_mut() {
-                        *c *= op;
+                let dx = m[0][2] as i64;
+                let srow = &img.data[sy as usize * img.width as usize..(sy as usize + 1) * img.width as usize];
+                let xa = (x0 as i64 + lo as i64).max(-dx).max(0) as usize;
+                let xb = ((x0 + hi) as i64).min(img.width as i64 - dx).max(0) as usize;
+                for x in xa..xb.max(xa) {
+                    let mut s = srow[(x as i64 + dx) as usize];
+                    if sampling == Sampling::Bicubic {
+                        s = [s[0].max(0.0), s[1].max(0.0), s[2].max(0.0), s[3].max(0.0)];
                     }
+                    if s[3] <= 0.0 {
+                        continue;
+                    }
+                    if op < 1.0 {
+                        for c in s.iter_mut() {
+                            *c *= op;
+                        }
+                    }
+                    row[x] = blend(row[x], s, x as u32, y as u32);
+                    if let Some((l, inv)) = levels {
+                        crate::quantize_px(&mut row[x], l, inv);
+                    }
+                    changed.add(x);
                 }
-                row[x] = blend(row[x], s, x as u32, y as u32);
-            }
-            return;
-        }
-        for i in lo..hi {
-            let x = x0 + i;
-            let p = vec2(p0.x + step.x * i as f64, p0.y + step.y * i as f64);
-            if p.x < -1.0 || p.y < -1.0 || p.x > iw + 1.0 || p.y > ih + 1.0 {
-                continue;
-            }
-            let mut s = match sampling {
-                Sampling::Nearest => img.get(p.x.floor() as i64, p.y.floor() as i64),
-                Sampling::Bilinear => sample_bilinear_fast(img, p.x, p.y),
-                Sampling::Bicubic => img.sample_bicubic(p.x, p.y),
-            };
-            if s[3] <= 0.0 {
-                continue;
-            }
-            if op < 1.0 {
-                for c in s.iter_mut() {
-                    *c *= op;
+            } else {
+                for i in lo..hi {
+                    let x = x0 + i;
+                    let p = vec2(p0.x + step.x * i as f64, p0.y + step.y * i as f64);
+                    if p.x < -1.0 || p.y < -1.0 || p.x > iw + 1.0 || p.y > ih + 1.0 {
+                        continue;
+                    }
+                    let mut s = match (sampling, &clear) {
+                        (Sampling::Nearest, _) => img.get(p.x.floor() as i64, p.y.floor() as i64),
+                        (Sampling::Bilinear, Some(clear)) => match sample_bilinear_fast(img, clear, p.x, p.y) {
+                            Some(s) => s,
+                            None => continue,
+                        },
+                        (Sampling::Bilinear, None) => img.sample_bilinear(p.x, p.y),
+                        (Sampling::Bicubic, _) => img.sample_bicubic(p.x, p.y),
+                    };
+                    if s[3] <= 0.0 {
+                        continue;
+                    }
+                    if op < 1.0 {
+                        for c in s.iter_mut() {
+                            *c *= op;
+                        }
+                    }
+                    row[x] = blend(row[x], s, x as u32, y as u32);
+                    if let Some((l, inv)) = levels {
+                        crate::quantize_px(&mut row[x], l, inv);
+                    }
+                    changed.add(x);
                 }
             }
-            row[x] = blend(row[x], s, x as u32, y as u32);
-        }
-    });
+            if changed.a < changed.b { [changed.a, y, changed.b, y + 1] } else { empty }
+        })
+        .reduce(|| empty, union)
 }
 
-fn composite_warp_impl(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts, allow_fast: bool, accumulate: Option<f32>) {
+fn composite_warp_impl(
+    dst: &mut Image,
+    src: &Image,
+    m: &Mat3,
+    opts: &WarpOpts,
+    allow_fast: bool,
+    accumulate: Option<f32>,
+    quantize: Option<f32>,
+) -> Option<[u32; 4]> {
+    const NOTHING: Option<[u32; 4]> = Some([0; 4]);
     if src.is_empty() || dst.is_empty() || opts.opacity <= 0.0 {
-        return;
+        return NOTHING;
     }
-    let Some(inv) = m.inverse() else { return };
+    let Some(inv) = m.inverse() else { return NOTHING };
     // Minification: pick a pre-filtered level so sampling doesn't alias.
     let scale = m.mean_scale();
     let mut level_img;
@@ -239,7 +346,7 @@ fn composite_warp_impl(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts,
         area = area.intersect(&c);
     }
     if area.is_empty() {
-        return;
+        return NOTHING;
     }
     let (x0, x1) = (area.x0.max(0.0) as usize, area.x1.min(dst.width as f64) as usize);
     let (y0, y1) = (area.y0.max(0.0) as usize, area.y1.min(dst.height as f64) as usize);
@@ -247,25 +354,34 @@ fn composite_warp_impl(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts,
     let affine = inv.is_affine();
     let mode = opts.mode;
     let op = opts.opacity;
+    let changed = |r: [usize; 4]| Some(r.map(|v| v.min(u32::MAX as usize) as u32));
     if let Some(k) = accumulate
         && affine
     {
-        affine_rows(dst, img, &inv, opts.sampling, 1.0, x0, x1, y0, y1, |d, s, _, _| [d[0] + s[0] * k, d[1] + s[1] * k, d[2] + s[2] * k, d[3] + s[3] * k]);
-        return;
+        let r = affine_rows(dst, img, &inv, AffineRows { sampling: opts.sampling, opacity: 1.0, quantize: None, bounds: [x0, x1, y0, y1] }, |d, s, _, _| {
+            [d[0] + s[0] * k, d[1] + s[1] * k, d[2] + s[2] * k, d[3] + s[3] * k]
+        });
+        return changed(r);
     }
     if allow_fast && affine && !mode.is_stencil() {
-        match mode {
-            BlendMode::Normal => affine_rows(dst, img, &inv, opts.sampling, op, x0, x1, y0, y1, |d, s, _, _| {
-                let k = 1.0 - s[3];
-                [s[0] + d[0] * k, s[1] + d[1] * k, s[2] + d[2] * k, s[3] + d[3] * k]
-            }),
+        let r = match mode {
+            BlendMode::Normal => {
+                affine_rows(dst, img, &inv, AffineRows { sampling: opts.sampling, opacity: op, quantize, bounds: [x0, x1, y0, y1] }, |d, s, _, _| {
+                    let k = 1.0 - s[3];
+                    [s[0] + d[0] * k, s[1] + d[1] * k, s[2] + d[2] * k, s[3] + d[3] * k]
+                })
+            }
             BlendMode::Dissolve | BlendMode::DancingDissolve => {
                 let seed = opts.seed;
-                affine_rows(dst, img, &inv, opts.sampling, op, x0, x1, y0, y1, |d, s, x, y| blend_pixel(mode, d, s, hash_noise(x, y, seed)))
+                affine_rows(dst, img, &inv, AffineRows { sampling: opts.sampling, opacity: op, quantize, bounds: [x0, x1, y0, y1] }, |d, s, x, y| {
+                    blend_pixel(mode, d, s, hash_noise(x, y, seed))
+                })
             }
-            _ => affine_rows(dst, img, &inv, opts.sampling, op, x0, x1, y0, y1, |d, s, _, _| blend_pixel(mode, d, s, 0.5)),
-        }
-        return;
+            _ => affine_rows(dst, img, &inv, AffineRows { sampling: opts.sampling, opacity: op, quantize, bounds: [x0, x1, y0, y1] }, |d, s, _, _| {
+                blend_pixel(mode, d, s, 0.5)
+            }),
+        };
+        return changed(r);
     }
     dst.data.par_chunks_mut(w).enumerate().skip(y0).take(y1 - y0).for_each(|(y, row)| {
         let fy = y as f64 + 0.5;
@@ -312,6 +428,7 @@ fn composite_warp_impl(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts,
             }
         }
     }
+    None
 }
 
 /// Resize with bilinear filtering (box pre-filter when shrinking).
@@ -394,6 +511,116 @@ mod tests {
         }
     }
 
+    /// A mostly transparent source: a thin ring with a few stray pixels (one with negative zero alpha).
+    fn sparse_image(w: u32, h: u32) -> Image {
+        let mut img = Image::new(w, h);
+        let (cx, cy, r) = (w as f32 / 2.0, h as f32 / 2.0, w.min(h) as f32 * 0.4);
+        for y in 0..h {
+            for x in 0..w {
+                let d = ((x as f32 + 0.5 - cx).hypot(y as f32 + 0.5 - cy) - r).abs();
+                if d < 1.5 {
+                    let a = 1.0 - d / 1.5;
+                    img.set(x, y, [0.2 * a, 0.6 * a, a, a]);
+                }
+            }
+        }
+        img.set(3, 2, [0.5, 0.5, 0.5, 0.5]);
+        img.set(w - 1, h - 1, [1.0; 4]);
+        img.set(w / 2, 1, [0.0, 0.0, 0.0, -0.0]);
+        img
+    }
+
+    #[test]
+    fn clear_tiles_hold_only_transparent_taps() {
+        let img = sparse_image(150, 97);
+        let clear = ClearTiles::new(&img);
+        let mut skipped = 0;
+        for y in 0..img.height as usize - 1 {
+            for x in 0..img.width as usize - 1 {
+                if clear.is_clear(x, y) {
+                    skipped += 1;
+                    for (dx, dy) in [(0, 0), (1, 0), (0, 1), (1, 1)] {
+                        assert_eq!(img.get(x as i64 + dx, y as i64 + dy)[3], 0.0, "tap ({}, {}) of a clear tile", x as i64 + dx, y as i64 + dy);
+                    }
+                }
+            }
+        }
+        assert!(skipped > 100 * 70, "the ring's empty middle is skipped: {skipped}");
+    }
+
+    /// The changed rectangle holds every pixel a warp changed, and the skipped transparent
+    /// samples leave the result as the reference path draws it.
+    #[test]
+    fn changed_rect_covers_the_changed_pixels() {
+        let src = sparse_image(90, 70);
+        let mats = [
+            Mat3::translate(vec2(7.0, 3.0)),
+            Mat3::translate(vec2(10.25, 4.5)),
+            Mat3::translate(vec2(60.0, 50.0)) * Mat3::rotate_deg(33.0) * Mat3::scale(vec2(0.9, 1.2)) * Mat3::translate(vec2(-45.0, -35.0)),
+            Mat3::translate(vec2(-30.0, -20.0)),
+            Mat3::scale(vec2(0.3, 0.3)),
+        ];
+        for (mi, m) in mats.iter().enumerate() {
+            for mode in [BlendMode::Normal, BlendMode::Add, BlendMode::Dissolve] {
+                let opts = WarpOpts { mode, seed: 3, ..Default::default() };
+                let before = test_image(120, 100, 4);
+                let mut a = before.clone();
+                let r = composite_warp_changed(&mut a, &src, m, &opts, None);
+                let Some([x0, y0, x1, y1]) = r else { panic!("mat {mi}: the fast path tracks what it changed") };
+                for (i, (p, q)) in a.data.iter().zip(&before.data).enumerate() {
+                    let (x, y) = (i as u32 % a.width, i as u32 / a.width);
+                    if p != q {
+                        assert!(x >= x0 && x < x1 && y >= y0 && y < y1, "mat {mi} {mode:?}: ({x}, {y}) changed outside {r:?}");
+                    }
+                }
+                let mut b = before.clone();
+                composite_warp_reference(&mut b, &src, m, &opts);
+                for (i, (p, q)) in a.data.iter().zip(&b.data).enumerate() {
+                    for c in 0..4 {
+                        assert!((p[c] - q[c]).abs() < 1e-4, "mat {mi} {mode:?} px {i}: {p:?} vs {q:?}");
+                    }
+                }
+            }
+        }
+        let mut dst = Image::new(10, 10);
+        assert_eq!(composite_warp_changed(&mut dst, &Image::new(4, 4), &Mat3::IDENTITY, &WarpOpts::default(), None), Some([u32::MAX, u32::MAX, 0, 0]));
+        let stencil = WarpOpts { mode: BlendMode::StencilAlpha, ..Default::default() };
+        assert_eq!(composite_warp_changed(&mut dst, &src, &Mat3::IDENTITY, &stencil, Some(255.0)), None, "stencils change the whole destination");
+    }
+
+    /// Quantising while blending equals blending, then quantising the changed rectangle of an
+    /// already quantised destination (what an 8/16 bpc comp did after every layer), bit for bit.
+    #[test]
+    fn quantize_while_blending_matches_quantizing_after() {
+        let src = sparse_image(90, 70);
+        let mats = [Mat3::translate(vec2(7.0, 3.0)), Mat3::translate(vec2(60.0, 50.0)) * Mat3::rotate_deg(33.0) * Mat3::translate(vec2(-45.0, -35.0))];
+        for m in &mats {
+            for mode in [BlendMode::Normal, BlendMode::Screen, BlendMode::Dissolve] {
+                for (levels, opacity) in [(255.0f32, 1.0), (32_768.0, 0.7)] {
+                    let mut before = test_image(120, 100, 8);
+                    for p in &mut before.data {
+                        crate::quantize_px(p, levels, 1.0 / levels);
+                    }
+                    let opts = WarpOpts { mode, opacity, seed: 5, ..Default::default() };
+                    let mut after = before.clone();
+                    let Some([x0, y0, x1, y1]) = composite_warp_changed(&mut after, &src, m, &opts, None) else { panic!("fast path") };
+                    for y in y0..y1 {
+                        for x in x0..x1 {
+                            let i = after.idx(x, y);
+                            crate::quantize_px(&mut after.data[i], levels, 1.0 / levels);
+                        }
+                    }
+                    let mut fused = before.clone();
+                    let r = composite_warp_changed(&mut fused, &src, m, &opts, Some(levels));
+                    assert_eq!(r, Some([x0, y0, x1, y1]));
+                    for (i, (p, q)) in fused.data.iter().zip(&after.data).enumerate() {
+                        assert_eq!(p.map(f32::to_bits), q.map(f32::to_bits), "{mode:?} {levels} px {i}");
+                    }
+                }
+            }
+        }
+    }
+
     /// Accumulating sub-samples equals warping each into its own image and summing.
     #[test]
     fn accumulate_matches_per_sample_images() {
diff --git a/crates/raster/src/yuv.rs b/crates/raster/src/yuv.rs
new file mode 100644
index 000000000..fdfbc0c0a
--- /dev/null
+++ b/crates/raster/src/yuv.rs
@@ -0,0 +1,60 @@
+//! 8-bit BT.709 limited-range 4:2:0, the H.264 export's input. Shared by the export and by the
+//! GPU compositor's tests, which hold its kernel to this function.
+
+use rayon::prelude::*;
+
+/// `v / 255` for every 8-bit `v` (the same values as dividing).
+pub const UNIT8: [f32; 256] = {
+    let mut t = [0.0; 256];
+    let mut i = 0;
+    while i < 256 {
+        t[i] = i as f32 / 255.0;
+        i += 1;
+    }
+    t
+};
+
+/// `v.round()` for `0 <= v < 2^23`, the range the colour conversions round in: truncation and
+/// the fraction are exact there, so this is `f32::round` without its libm call.
+#[inline(always)]
+pub fn round_pos(v: f32) -> f32 {
+    let t = v as u32 as f32;
+    if v - t >= 0.5 { t + 1.0 } else { t }
+}
+
+/// BT.709 limited-range 8-bit 4:2:0 from RGBA8 (2×2 chroma average; alpha ignored).
+pub fn rgba_to_yuv420(rgba: &[u8], w: usize, h: usize, y: &mut Vec<u8>, u: &mut Vec<u8>, v: &mut Vec<u8>) {
+    let (cw, ch) = (w.div_ceil(2), h.div_ceil(2));
+    y.resize(w * h, 0);
+    u.resize(cw * ch, 0);
+    v.resize(cw * ch, 0);
+    y.par_chunks_mut(w * 2).zip(u.par_chunks_mut(cw).zip(v.par_chunks_mut(cw))).enumerate().for_each(|(cy, (yr, (ur, vr)))| {
+        let mut acc = vec![(0f32, 0f32, 0f32); cw];
+        for (dy, yrow) in yr.chunks_exact_mut(w).enumerate() {
+            let src = &rgba[(cy * 2 + dy) * w * 4..][..w * 4];
+            for (x, (s, yo)) in src.as_chunks::<4>().0.iter().zip(yrow.iter_mut()).enumerate() {
+                let (r, g, b) = (UNIT8[s[0] as usize], UNIT8[s[1] as usize], UNIT8[s[2] as usize]);
+                let l = 0.2126 * r + 0.7152 * g + 0.0722 * b;
+                *yo = round_pos(16.0 + 219.0 * l).clamp(1.0, 254.0) as u8;
+                let a = &mut acc[x / 2];
+                a.0 += (b - l) / 1.8556;
+                a.1 += (r - l) / 1.5748;
+                a.2 += 1.0;
+            }
+        }
+        for (cx, a) in acc.iter().enumerate() {
+            ur[cx] = round_pos(128.0 + 224.0 * a.0 / a.2).clamp(1.0, 254.0) as u8;
+            vr[cx] = round_pos(128.0 + 224.0 * a.1 / a.2).clamp(1.0, 254.0) as u8;
+        }
+    });
+}
+
+/// The H.264 export's planes of `img` over `bg` (opaque): Y, then U and V, as
+/// [`crate::Image::to_rgba8_over`] + [`rgba_to_yuv420`] produce them.
+pub fn yuv420_over(img: &crate::Image, bg: [f32; 3]) -> Vec<u8> {
+    let (mut y, mut u, mut v) = (vec![], vec![], vec![]);
+    rgba_to_yuv420(&img.to_rgba8_over(bg), img.width as usize, img.height as usize, &mut y, &mut u, &mut v);
+    y.extend_from_slice(&u);
+    y.extend_from_slice(&v);
+    y
+}
diff --git a/crates/render/src/accel.rs b/crates/render/src/accel.rs
new file mode 100644
index 000000000..accc1fc54
--- /dev/null
+++ b/crates/render/src/accel.rs
@@ -0,0 +1,362 @@
+use super::frames::content_bounds;
+use super::fx_host::MAX_FX_DEPTH;
+use super::layers::StyledLayer;
+use super::opts::LayerTiming;
+use super::{
+    Arc, AutoPick, Buf, EffectCtx, EvalCtx, Image, ItemId, ItemKind, Layer, LayerSource, Mat3, MatteKind, Renderer, Tick, cache, color, masks, three_d, vec2,
+};
+
+/// Which compositor renders a frame (Project Settings ▸ Video Rendering and Effects).
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum Backend {
+    /// The CPU reference compositor (Mercury Software Only).
+    #[default]
+    Cpu,
+    /// The GPU compositor whenever an [`Accelerator`] is attached, whatever the project says.
+    Gpu,
+    /// The GPU compositor when an [`Accelerator`] is attached and the project's renderer is
+    /// Mercury GPU Acceleration (the viewer's choice); the CPU otherwise.
+    Auto,
+}
+
+impl Backend {
+    pub fn parse(s: &str) -> Option<Backend> {
+        match s.to_ascii_lowercase().as_str() {
+            "cpu" | "software" | "mercury software only" => Some(Backend::Cpu),
+            "gpu" | "mercury gpu acceleration" => Some(Backend::Gpu),
+            "auto" => Some(Backend::Auto),
+            _ => None,
+        }
+    }
+}
+
+/// One effect of a GPU effect chain (see [`Accelerator::effects`]).
+pub struct FxStep<'x> {
+    pub spec: &'static effectcraft_effects::EffectSpec,
+    pub ctx: EffectCtx<'x>,
+}
+
+/// A GPU (or other hardware) backend for the compositor. The CPU [`Renderer`] stays the
+/// reference: an accelerator renders what it supports and returns `None` for the rest, which
+/// then runs on the CPU. Implemented by `effectcraft-gpu`.
+pub trait Accelerator: Send + Sync {
+    /// Adapter / backend name for status readouts ("Apple M2 (Metal)").
+    fn name(&self) -> String;
+    /// Render a top-level comp frame (what [`Renderer::comp_frame`] returns). `None` = not
+    /// handled (the CPU renders it).
+    fn comp_frame(&self, r: &Renderer, comp: ItemId, t: Tick) -> Option<Image>;
+    /// Render a top-level comp frame like [`Self::comp_frame`], composite it over `bg` and
+    /// convert it to the H.264 export's 8-bit BT.709 limited-range 4:2:0 (Y plane, then U and V
+    /// at half size; see `effectcraft_raster::yuv`). Every byte is within one level of the CPU
+    /// conversion of the same frame (a driver's arithmetic may move a value near a rounding
+    /// boundary). `None` = not handled (the caller renders and converts on the CPU).
+    fn comp_frame_yuv420(&self, _r: &Renderer, _comp: ItemId, _t: Tick, _bg: [f32; 3]) -> Option<Vec<u8>> {
+        None
+    }
+    /// The accelerator implements effect `id` with the CPU effect's semantics.
+    fn supports_effect(&self, id: &str) -> bool;
+    /// Run a chain of supported effects on `buf`, clamping and quantising to `levels` after
+    /// every effect when set (8/16 bpc). `None` = not handled.
+    fn effects(&self, chain: &[FxStep], buf: &Buf, levels: Option<f32>) -> Option<Buf>;
+    /// Rasterise and shade an Advanced 3D scene at its raster size (depth buffer, PBR, image
+    /// based light, shadow maps), with the CPU rasteriser's semantics
+    /// ([`three_d::adv::raster::render`]). `None` = not handled (the CPU renders it).
+    fn raster_3d(&self, _scene: &three_d::adv::Scene) -> Option<three_d::adv::Target> {
+        None
+    }
+    /// Render a whole prepared Advanced 3D run (every motion-blur sub-sample rasterised and
+    /// resolved, averaged, depth of field, encoding) with [`three_d::adv::render_prepared`]'s
+    /// semantics. `None` = not handled (the CPU path runs, using [`Self::raster_3d`]).
+    fn render_3d(&self, _run: &three_d::adv::Prepared) -> Option<three_d::adv::Rendered> {
+        None
+    }
+    /// A particle simulation backend (GPU particles) for the stepped particle effects, with
+    /// the CPU simulation's semantics. `None` = they simulate on the CPU.
+    fn particles(&self) -> Option<&dyn effectcraft_effects::psim::ParticleSim> {
+        None
+    }
+    /// Timing history [`Backend::Auto`] uses to send each comp's top-level frames to the
+    /// faster compositor. `None` = Auto always tries the accelerator first.
+    fn auto_pick(&self) -> Option<&AutoPick> {
+        None
+    }
+    /// Whether the accelerator can still render frames. `false` once it has stopped for good
+    /// (its device was lost or retired): every frame it is asked for falls back to the CPU, so
+    /// callers that limit frames in flight for it can stop doing so.
+    fn available(&self) -> bool {
+        true
+    }
+    /// Deferred readbacks: where a GPU readback cannot be waited for (WebGPU in a browser
+    /// worker), a frame renders in *passes*. A readback the accelerator does not have yet is
+    /// started, the step returns a cheap placeholder and the pass is marked missed
+    /// ([`Self::pass_missed`]); the caller waits for the readbacks in flight (asynchronously)
+    /// and renders the frame again, and the steps whose results arrived are served from them.
+    /// The frame is done after a pass with no miss. `frame_begin` forgets the previous frame's
+    /// results, `pass_begin` clears the miss. Synchronous accelerators never miss.
+    fn frame_begin(&self) {}
+    fn pass_begin(&self) {}
+    fn pass_missed(&self) -> bool {
+        false
+    }
+    /// Raised from a pass's first miss to its end (results computed meanwhile may hold
+    /// placeholders): give it to [`LayerCache::set_gate`] so they are not cached.
+    fn miss_gate(&self) -> Option<Arc<std::sync::atomic::AtomicBool>> {
+        None
+    }
+    /// With deferred readbacks: a future that resolves once the readbacks in flight have
+    /// landed (the browser delivers them from its event loop; natively the device is polled
+    /// before it returns, so the future is ready). `None` = nothing to wait for. See
+    /// [`passes::in_passes`].
+    fn settle(&self) -> Option<std::pin::Pin<Box<dyn std::future::Future<Output = ()> + '_>>> {
+        None
+    }
+}
+
+/// Where an effect stack runs (see [`Renderer::run_effects_on`]): a CPU buffer, or an image
+/// resident on an accelerator.
+pub trait FxTarget {
+    /// Run a chain of accelerator-supported effects (quantising after each to the bit depth).
+    /// `false` = not handled: the effects then run one by one through [`FxTarget::cpu`].
+    fn gpu(&mut self, steps: &[FxStep]) -> bool;
+    /// Run one CPU effect: `f` maps the buffer.
+    fn cpu(&mut self, f: &mut dyn FnMut(Buf) -> Buf);
+    /// Grow the buffer to cover its whole layer rectangle (`size` layer pixels from its own
+    /// corner, the `layer_size` handed to effects), as [`effectcraft_effects::Buf::cover`].
+    /// Authored buffers (text, shapes) only span their painted content; this gives the stack
+    /// the room a sized source's buffer already has (#659).
+    fn cover(&mut self, size: [f64; 2]) {
+        self.cpu(&mut |mut buf| {
+            buf.cover(size);
+            buf
+        });
+    }
+}
+
+/// The CPU effect target (GPU chains go through [`Accelerator::effects`]: upload, readback).
+pub(crate) struct CpuFx<'a> {
+    pub(crate) accel: Option<&'a dyn Accelerator>,
+    pub(crate) levels: Option<f32>,
+    pub(crate) buf: Option<Buf>,
+}
+
+impl FxTarget for CpuFx<'_> {
+    fn gpu(&mut self, steps: &[FxStep]) -> bool {
+        let (Some(a), Some(b)) = (self.accel, &self.buf) else { return false };
+        match a.effects(steps, b, self.levels) {
+            Some(out) => {
+                self.buf = Some(out);
+                true
+            }
+            None => false,
+        }
+    }
+    fn cpu(&mut self, f: &mut dyn FnMut(Buf) -> Buf) {
+        if let Some(b) = self.buf.take() {
+            self.buf = Some(f(b));
+        }
+    }
+}
+
+/// Hooks for accelerated compositors (`effectcraft-gpu`): the pieces of the CPU walk they reuse
+/// or fall back to. The CPU compositor itself is [`Renderer::comp_frame_cpu`].
+impl<'a> Renderer<'a> {
+    /// The project's colour pipeline.
+    pub fn pipe(&self) -> color::Pipe {
+        self.pipe
+    }
+
+    /// Nesting depth (0 = the top-level comp).
+    pub fn depth(&self) -> usize {
+        self.depth
+    }
+
+    /// The auxiliary 3D channels of comp `comp_id` at comp time `t` (depth, layer IDs, normals,
+    /// UVs, Cryptomatte; see `three_d::compose::aux_pass`), at the renderer's output scale.
+    pub fn comp_aux(&self, comp_id: ItemId, t: Tick) -> Option<effectcraft_raster::AuxChannels> {
+        let ctx = self.eval_ctx(comp_id, t)?;
+        Some(three_d::compose::aux_pass(self, &ctx))
+    }
+
+    /// The auxiliary channels effects on `layer` read ([`EffectHost::aux`]): its multi-layer
+    /// OpenEXR footage's at the layer's source time (Time Remap included), or a precomp's
+    /// generated 3D channels at its nested time. `None` for other layers.
+    pub fn layer_aux(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Arc<effectcraft_raster::AuxChannels>> {
+        match &layer.source {
+            LayerSource::Footage { item } => {
+                let ItemKind::Footage(f) = &self.project.item(*item)?.kind else { return None };
+                let a = self.footage.aux(*item, f, ctx.source_time(layer))?;
+                // Aux pixels per layer pixel (the layer is the footage at its nominal size). The
+                // planes are only copied when that changes the scale.
+                let scale = a.width as f64 / f.width as f64;
+                if f.width > 0 && a.width > 0 && a.scale != scale {
+                    let mut a = (*a).clone();
+                    a.scale = scale;
+                    return Some(Arc::new(a));
+                }
+                Some(a)
+            }
+            LayerSource::Comp { item } => {
+                if self.depth > MAX_FX_DEPTH || self.project.comp_contains(*item, ctx.comp_id) {
+                    return None;
+                }
+                self.nested().comp_aux(*item, ctx.nested_time(layer)).map(Arc::new)
+            }
+            _ => None,
+        }
+    }
+
+    /// Evaluation context of comp `comp_id` at comp time `t`.
+    pub fn eval_ctx(&self, comp_id: ItemId, t: Tick) -> Option<EvalCtx<'a>> {
+        Some(self.ctx(comp_id, self.project.comp(comp_id)?, t))
+    }
+
+    /// The layers drawn at the context time, bottom to top (solo, guides and visibility
+    /// applied).
+    pub fn visible_layers(&self, ctx: &EvalCtx<'a>) -> Vec<&'a Layer> {
+        let (comp, t) = (ctx.comp, ctx.time);
+        let any_solo = comp.any_solo();
+        comp.layers
+            .iter()
+            .rev()
+            .filter(|l| l.is_active_at(t) && l.has_video() && !l.environment && (!any_solo || l.switches.solo) && (self.opts.guides || !l.switches.guide))
+            .collect()
+    }
+
+    /// Draw a run of consecutive 3D layers into `canvas` (CPU).
+    pub fn draw_3d_run(&self, ctx: &EvalCtx<'a>, run: &[&Layer], canvas: &mut Image) {
+        three_d::compose::draw_run(self, ctx, run, canvas);
+    }
+
+    /// A run of consecutive 3D layers prepared for an accelerator (planes, lights, shadow
+    /// casters; see [`three_d::Run3d`]) at output size `out`. `None` = draw it with
+    /// [`Self::draw_3d_run`] (adjustment or wireframe layers in the run, Advanced 3D).
+    pub fn prepare_3d_run(&self, ctx: &EvalCtx<'a>, run: &[&Layer], out: (u32, u32)) -> Option<three_d::Run3d> {
+        three_d::compose::gpu_run(self, ctx, run, out)
+    }
+
+    /// A run of consecutive 3D layers of an Advanced 3D comp prepared for an accelerator's
+    /// compositor ([`three_d::adv::Prepared`]): rendered as one scene and composited (Normal,
+    /// premultiplied over) onto the canvas. `None` = not an Advanced 3D comp, or a layer needs the
+    /// 2D compositing path (blend mode, track matte, Preserve Transparency): draw it with
+    /// [`Self::draw_3d_run`].
+    pub fn prepare_adv_run<'p>(&'p self, ctx: &'p EvalCtx<'a>, run: &'p [&'p Layer], out: (u32, u32)) -> Option<three_d::adv::Prepared<'p, 'a>> {
+        three_d::adv::prepare_run(self, ctx, run, out)
+    }
+
+    /// A run of consecutive 3D layers of an Advanced 3D comp whose layers need the 2D
+    /// compositing path (blend mode, track matte, Preserve Transparency), split for an
+    /// accelerator's compositor ([`three_d::adv::SplitRun`]). `None` = [`Self::prepare_adv_run`]
+    /// covers it, or it isn't an Advanced 3D run.
+    pub fn split_adv_run<'p>(&'p self, ctx: &'p EvalCtx<'a>, run: &'p [&'p Layer], out: (u32, u32)) -> Option<three_d::adv::SplitRun<'p, 'a>> {
+        three_d::adv::split_run(self, ctx, run, out)
+    }
+
+    /// Whether the comp's 3D layers draw with the Advanced 3D renderer.
+    pub fn is_adv3d(&self, ctx: &EvalCtx) -> bool {
+        three_d::adv::active(self, ctx)
+    }
+
+    /// An Environment Light Background layer ready to draw on an accelerator
+    /// ([`three_d::SkyDraw`]; the CPU draws it in `draw_3d_run`). `None` = nothing to draw.
+    pub fn sky_draw(&self, ctx: &EvalCtx, layer: &Layer) -> Option<three_d::SkyDraw> {
+        three_d::compose::sky_draw(self, ctx, layer)
+    }
+
+    /// The pixels a Wireframe-quality layer sets (white, opaque) on a `size` canvas: its
+    /// bounds' outline, one pixel wide. Empty when the layer has no bounds.
+    pub fn wireframe_pixels(&self, ctx: &EvalCtx, layer: &Layer, size: (u32, u32)) -> Vec<(u32, u32)> {
+        let Some(b) = content_bounds(ctx, layer) else { return vec![] };
+        let s = self.opts.scale;
+        let (l2c, _) = ctx.layer_to_comp(layer);
+        let m = Mat3::scale(vec2(s, s)) * self.outer.map_or(l2c, |o| o * l2c);
+        let c = [(b[0], b[1]), (b[2], b[1]), (b[2], b[3]), (b[0], b[3])].map(|(x, y)| m.apply(vec2(x, y)));
+        let (w, h) = (size.0 as i64, size.1 as i64);
+        let mut out = vec![];
+        for i in 0..4 {
+            let (p, q) = (c[i], c[(i + 1) % 4]);
+            let n = ((q.x - p.x).abs().max((q.y - p.y).abs()) * 2.0).ceil().clamp(1.0, 1.0e5) as usize;
+            for j in 0..=n {
+                let t = j as f64 / n as f64;
+                let (x, y) = ((p.x + (q.x - p.x) * t).floor() as i64, (p.y + (q.y - p.y) * t).floor() as i64);
+                if x >= 0 && y >= 0 && x < w && y < h {
+                    out.push((x as u32, y as u32));
+                }
+            }
+        }
+        out
+    }
+
+    /// Run the layer's effect stack on `target` (an accelerator's resident image): GPU-capable
+    /// runs through [`FxTarget::gpu`], the others through [`FxTarget::cpu`], with the CPU's
+    /// parameters and environment. `adjustment`: the stack runs on the comp below (adjustment
+    /// layers).
+    pub fn run_effects_on(&self, ctx: &EvalCtx, layer: &Layer, adjustment: bool, target: &mut dyn FxTarget) {
+        // `target` is used as it is: the comp below for adjustment layers (the callers).
+        self.run_effect_stack(ctx, layer, crate::pipeline::EffectStack { adjustment, limit: usize::MAX, origin: [0.0; 2] }, None, target);
+    }
+
+    /// [`Renderer::run_effects_on`] for a (non-adjustment) layer's own pixels: `target` holds
+    /// them in effect space (as [`Renderer::layer_input`] hands them out) and the result stays
+    /// there. Returns the effect-space origin in layer coordinates (rebase by its negation).
+    pub fn run_layer_effects_on(&self, ctx: &EvalCtx, layer: &Layer, target: &mut dyn FxTarget) -> [f64; 2] {
+        let origin = ctx.effect_bounds(layer).1;
+        self.run_effect_stack(ctx, layer, crate::pipeline::EffectStack { adjustment: false, limit: usize::MAX, origin }, None, target);
+        origin
+    }
+
+    /// An adjustment layer's footprint (its source with masks applied, layer space): where
+    /// its effects show. `None` = the layer changes nothing.
+    pub fn adjustment_footprint(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Arc<Buf>> {
+        // Cached, so an accelerator sees the same buffer (and uploads it once) every frame.
+        let key = self.cache.and_then(|_| cache::footprint_key(ctx, layer, self.raster_scale(ctx, layer), self.opts.draft, self.mb_on(ctx, layer)));
+        if let (Some(c), Some(k)) = (self.cache, key)
+            && let Some(b) = c.get(k)
+        {
+            return Some(b);
+        }
+        let mut foot = self.source(ctx, layer)?;
+        let _ = masks::apply(ctx, layer, &mut foot, self.mask_blur(ctx, layer));
+        let foot = Arc::new(foot);
+        // The buffer the cache keeps (another worker's, if it kept one first).
+        let foot = match (self.cache_to_keep(), key) {
+            (Some(c), Some(k)) => c.insert(k, foot),
+            _ => foot,
+        };
+        Some(foot)
+    }
+
+    /// Draw one 2D layer into `canvas` on the CPU (any kind: adjustment, wireframe, styled…).
+    pub fn draw_layer_cpu(&self, ctx: &EvalCtx, layer: &Layer, canvas: &mut Image) {
+        self.draw_layer(ctx, layer, canvas, false);
+    }
+
+    /// Draw a collapsed precomp layer into `canvas` on the CPU.
+    pub fn draw_collapsed_cpu(&self, ctx: &EvalCtx<'a>, layer: &Layer, item: ItemId, canvas: &mut Image) {
+        self.draw_collapsed(ctx, layer, item, canvas, false);
+    }
+
+    /// The layer's finished buffers (styles included) in the blending space.
+    pub fn styled_layer(&self, ctx: &EvalCtx, layer: &Layer) -> Option<StyledLayer> {
+        let mut timing = self.profile.map(|_| LayerTiming { depth: self.depth, layer: layer.name.clone(), ..Default::default() });
+        let t0 = web_time::Instant::now();
+        let st = self.styled(ctx, layer, timing.as_mut()).map(|st| self.styled_to_blend(st));
+        if let (Some(prof), Some(mut timing)) = (self.profile, timing) {
+            timing.process_ms = t0.elapsed().as_secs_f64() * 1e3;
+            if let Ok(mut v) = prof.lock() {
+                v.push(timing);
+            }
+        }
+        st
+    }
+
+    /// Opacity the layer composites with (its Opacity × collapsed precomps' opacity).
+    pub fn layer_opacity(&self, ctx: &EvalCtx, layer: &Layer) -> f32 {
+        ctx.opacity(layer) as f32 * self.opacity_mul
+    }
+
+    /// The layer's track matte layer and kind, if it has a valid one.
+    pub fn track_matte<'c>(&self, ctx: &EvalCtx<'c>, layer: &Layer) -> Option<(&'c Layer, MatteKind)> {
+        layer.track_matte.and_then(|tm| ctx.comp.layer(tm.layer).filter(|m| m.id != layer.id).map(|m| (m, tm.kind)))
+    }
+}
diff --git a/crates/render/src/audio.rs b/crates/render/src/audio.rs
index 68be63fe4..66b54b6d0 100644
--- a/crates/render/src/audio.rs
+++ b/crates/render/src/audio.rs
@@ -25,7 +25,7 @@ const MAX_DEPTH: usize = 16;
 /// interleaved (L R L R …).
 pub fn mix_comp(project: &Project, footage: &dyn FootageSource, expr: Option<&dyn ExprHost>, comp: ItemId, start: Tick, frames: usize, rate: u32) -> Vec<f32> {
     let mut out = vec![0.0f32; frames * 2];
-    mix_into(project, footage, expr, comp, start, rate, &mut out, 1.0, 1.0, 0);
+    mix_into(&AudioSources { project, footage, expr, rate }, comp, start, &mut out, 0);
     out
 }
 
@@ -151,7 +151,7 @@ impl MixEnv<'_> {
                     return out;
                 }
                 let mut sub = vec![0.0f32; src_n * 2];
-                mix_into(self.project, self.footage, self.expr, *item, lt, rate, &mut sub, 1.0, 1.0, self.depth + 1);
+                mix_into(&AudioSources { project: self.project, footage: self.footage, expr: self.expr, rate }, *item, lt, &mut sub, self.depth + 1);
                 sub
             }
             _ => return out,
@@ -206,19 +206,16 @@ impl MixEnv<'_> {
     }
 }
 
-#[allow(clippy::too_many_arguments)]
-fn mix_into(
-    project: &Project,
-    footage: &dyn FootageSource,
-    expr: Option<&dyn ExprHost>,
-    comp_id: ItemId,
-    start: Tick,
+/// Shared inputs for composition audio mixing, including nested compositions.
+struct AudioSources<'a> {
+    project: &'a Project,
+    footage: &'a dyn FootageSource,
+    expr: Option<&'a dyn ExprHost>,
     rate: u32,
-    out: &mut [f32],
-    gl: f32,
-    gr: f32,
-    depth: usize,
-) {
+}
+
+fn mix_into(sources: &AudioSources<'_>, comp_id: ItemId, start: Tick, out: &mut [f32], depth: usize) {
+    let AudioSources { project, footage, expr, rate } = *sources;
     let Some(comp) = project.comp(comp_id) else { return };
     if depth >= MAX_DEPTH || rate == 0 {
         return;
@@ -239,7 +236,6 @@ fn mix_into(
         }
         let t_a = sample_tick(s0 + a as i64, rate);
         let (ll, lr) = levels(&env, l, t_a);
-        let (ll, lr) = (ll * gl, lr * gr);
         if ll == 0.0 && lr == 0.0 {
             continue;
         }
diff --git a/crates/render/src/cache.rs b/crates/render/src/cache.rs
index 89e9fd1c9..21f745c0e 100644
--- a/crates/render/src/cache.rs
+++ b/crates/render/src/cache.rs
@@ -580,7 +580,6 @@ fn key_with(ctx: &EvalCtx, layer: &Layer, scale: f64, draft: bool, blur: bool, f
 
 /// `blur`: the layer is motion blurred in this render (`Renderer::mb_on`). `effects`: key only
 /// the first that many effects (a layer's input, see [`input_key`]).
-#[allow(clippy::too_many_arguments)]
 fn key_any(ctx: &EvalCtx, layer: &Layer, scale: f64, draft: bool, blur: bool, footage: bool, effects: Option<usize>) -> Option<u64> {
     let mut h = KeyHasher(0xcbf2_9ce4_8422_2325);
     ctx.comp.frame_rate.as_f64().to_bits().hash(&mut h);
diff --git a/crates/render/src/color.rs b/crates/render/src/color.rs
index abfa791e8..d27526553 100644
--- a/crates/render/src/color.rs
+++ b/crates/render/src/color.rs
@@ -21,7 +21,7 @@
 
 use effectcraft_color::{ColorSpace, Conversion};
 use effectcraft_project::{Footage, HdrMode, ProjectSettings};
-use effectcraft_raster::Image;
+use effectcraft_raster::{Image, quantize_px};
 use rayon::prelude::*;
 
 /// The colour pipeline of a project (see the module docs).
@@ -218,27 +218,6 @@ pub fn quantize(img: &mut Image, levels: f32) {
     quantize_rect(img, PxRect { x0: 0, y0: 0, x1: img.width, y1: img.height }, levels);
 }
 
-/// Clamp (colour ≤ alpha ≤ 1, NaN → 0) and round half up; values are non-negative after the
-/// clamp, so the integer conversion rounds like `round()` and vectorises.
-#[allow(clippy::manual_clamp)] // max/min map NaN to 0; clamp would keep NaN
-#[inline(always)]
-fn quantize_px(p: &mut [f32; 4], levels: f32, inv: f32) {
-    let a = round_half_up(p[3].max(0.0).min(1.0) * levels) * inv;
-    let hi = [a, a, a, a];
-    for c in 0..3 {
-        p[c] = round_half_up(p[c].max(0.0).min(hi[c]) * levels) * inv;
-    }
-    p[3] = a;
-}
-
-/// `v` (0..=65 535) rounded half up. The same either way; the fastest on each target: x86-64's
-/// baseline converts to integers in one instruction but has no `floor` (SSE4.1), while in wasm
-/// `floor` is one instruction and converting back from `u32` several (about 1.5× faster there).
-#[inline(always)]
-fn round_half_up(v: f32) -> f32 {
-    if cfg!(target_arch = "wasm32") { (v + 0.5).floor() } else { (v + 0.5) as u32 as f32 }
-}
-
 /// [`quantize`] restricted to a rectangle (already clamped to the image), row-parallel.
 fn quantize_rect(img: &mut Image, r: PxRect, levels: f32) {
     if r.x0 >= r.x1 || r.y0 >= r.y1 {
@@ -248,7 +227,17 @@ fn quantize_rect(img: &mut Image, r: PxRect, levels: f32) {
     let w = img.width as usize;
     let (x0, x1) = (r.x0 as usize, r.x1 as usize);
     img.data[r.y0 as usize * w..r.y1 as usize * w].par_chunks_mut(w).for_each(|row| {
-        for p in &mut row[x0..x1] {
+        // Runs of all-zero pixels (+0.0 in every channel) quantise to themselves: skip them a
+        // cache line at a time (sparse shape, precomp and glow buffers are mostly empty).
+        let (blocks, rest) = row[x0..x1].as_chunks_mut::<4>();
+        for b in blocks {
+            if b.as_flattened().iter().fold(0, |a, v| a | v.to_bits()) != 0 {
+                for p in b {
+                    quantize_px(p, levels, inv);
+                }
+            }
+        }
+        for p in rest {
             quantize_px(p, levels, inv);
         }
     });
@@ -307,6 +296,39 @@ pub fn output_hdr(img: &mut Image, to_linear: Option<Conversion>, mode: HdrMode,
 
 #[cfg(test)]
 mod tests {
+    use super::*;
+
+    /// Skipping all-zero runs leaves every pixel as quantising it one by one does, bit for bit
+    /// (negative zeros and lone pixels in empty runs included).
+    #[test]
+    fn quantize_skips_only_zero_runs() {
+        let mut img = Image::new(23, 7);
+        for (i, p) in img.data.iter_mut().enumerate() {
+            *p = match i % 11 {
+                0 => [0.3, -0.2, 0.71, 0.9],
+                3 => [-0.0, 0.0, 0.0, 0.0],
+                5 => [0.0, 0.0, 0.0, -0.0],
+                7 => [1.7, 0.4, f32::NAN, 0.5],
+                _ => [0.0; 4],
+            };
+        }
+        for levels in [255.0f32, 32_768.0] {
+            let mut want = img.clone();
+            for p in &mut want.data {
+                quantize_px(p, levels, 1.0 / levels);
+            }
+            for r in [PxRect { x0: 0, y0: 0, x1: 23, y1: 7 }, PxRect { x0: 3, y0: 1, x1: 20, y1: 6 }] {
+                let mut got = img.clone();
+                quantize_rect(&mut got, r, levels);
+                for (i, (g, p)) in got.data.iter().zip(&img.data).enumerate() {
+                    let (x, y) = (i as u32 % 23, i as u32 / 23);
+                    let w = if x >= r.x0 && x < r.x1 && y >= r.y0 && y < r.y1 { want.data[i] } else { *p };
+                    assert_eq!(g.map(f32::to_bits), w.map(f32::to_bits), "{levels} {r:?} px ({x}, {y})");
+                }
+            }
+        }
+    }
+
     /// Both forms `round_half_up` picks between agree on everything quantising feeds it:
     /// 0..=levels, exact halves included.
     #[test]
diff --git a/crates/render/src/disk_cache.rs b/crates/render/src/disk_cache.rs
index 4fa2e1cb3..ca5660a67 100644
--- a/crates/render/src/disk_cache.rs
+++ b/crates/render/src/disk_cache.rs
@@ -12,9 +12,11 @@
 //!   `FrameSeg::to_bytes` (keyed by their content-keyed chain key and scale, so they are
 //!   reused whenever the same frames, settings and prompt come back, also after a restart). Every file ends in a checksum; damaged files read as misses and
 //!   are deleted.
-//! * Size limit with least-recently-used eviction. The in-memory index is rebuilt from the
-//!   folder when the cache opens (file modification times order it), so the cache survives
-//!   restarts; reads refresh a file's time.
+//! * Size limit with least-recently-used eviction, down to 90% of the limit so the eviction scan
+//!   runs once per tenth of the limit written, not on every write. The limit shrinks to keep
+//!   free space on the cache's disk ([`DiskCache::set_disk_space`]). The in-memory index is
+//!   rebuilt from the folder when the cache opens (file modification times order it), so the
+//!   cache survives restarts; reads refresh a file's time.
 //! * Safe concurrent access: writes go to a unique temporary file that is renamed into place
 //!   (atomic on every desktop OS), so readers in this or another process never see a partial
 //!   entry; a missing or damaged file is just a miss. Writes run on a background thread with a
@@ -22,7 +24,7 @@
 
 use std::collections::HashMap;
 use std::path::{Path, PathBuf};
-use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
 use std::sync::{Arc, Condvar, Mutex};
 
 use effectcraft_effects::Buf;
@@ -75,11 +77,15 @@ pub struct DiskStats {
     pub entries: usize,
     pub bytes: u64,
     pub max_bytes: u64,
+    /// The limit in effect: `max_bytes`, or less when the disk is short of free space.
+    pub limit_bytes: u64,
     pub hits: u64,
     pub misses: u64,
     pub writes: u64,
     pub evictions: u64,
     pub dropped: u64,
+    /// Writes that failed (a full disk, permissions).
+    pub failed: u64,
 }
 
 struct Meta {
@@ -157,15 +163,17 @@ impl DiskIndex {
         v.into_iter().map(|e| e.1).collect()
     }
 
-    /// Remove least recently used entries until the total fits `max` bytes; returns them (the
-    /// caller deletes their files).
+    /// When the total exceeds `max` bytes, remove least recently used entries down to 90% of
+    /// it (so the sort runs once per tenth of `max` written, not on every write); returns them
+    /// (the caller deletes their files).
     pub fn evict(&mut self, max: u64) -> Vec<(Kind, u128)> {
         if self.total <= max {
             return vec![];
         }
+        let target = max - max / 10;
         let mut out = vec![];
         for k in self.lru_order() {
-            if self.total <= max {
+            if self.total <= target {
                 break;
             }
             self.remove(k.0, k.1);
@@ -225,11 +233,16 @@ pub struct DiskCache {
     dir: PathBuf,
     index: Mutex<DiskIndex>,
     max_bytes: AtomicU64,
+    /// The size free disk space allows (`u64::MAX` = unknown), see [`DiskCache::set_disk_space`].
+    disk_cap: AtomicU64,
+    /// Free space is limiting the cache (warned once per episode).
+    space_limited: AtomicBool,
     hits: AtomicU64,
     misses: AtomicU64,
     writes: AtomicU64,
     evictions: AtomicU64,
     dropped: AtomicU64,
+    failed: AtomicU64,
     tmp_counter: AtomicU64,
     queue: Arc<(Mutex<Queue>, Condvar)>,
     /// Layer buffers that took less than this to render are not written (ms).
@@ -298,16 +311,21 @@ impl DiskCache {
             dir,
             index: Mutex::new(DiskIndex::default()),
             max_bytes: AtomicU64::new(max_bytes),
+            disk_cap: AtomicU64::new(u64::MAX),
+            space_limited: AtomicBool::new(false),
             hits: AtomicU64::new(0),
             misses: AtomicU64::new(0),
             writes: AtomicU64::new(0),
             evictions: AtomicU64::new(0),
             dropped: AtomicU64::new(0),
+            failed: AtomicU64::new(0),
             tmp_counter: AtomicU64::new(0),
-            queue: Arc::new((Mutex::new(Queue { jobs: Default::default(), busy: false }), Condvar::new())),
+            queue: Arc::new((Mutex::new(Queue { jobs: Default::default(), busy: cfg!(not(target_arch = "wasm32")) }), Condvar::new())),
             min_layer_ms: AtomicU64::new(30),
         });
         dc.rescan();
+        // Shrinking a large cache deletes many files: the writer thread does it.
+        #[cfg(target_arch = "wasm32")]
         dc.evict();
         #[cfg(not(target_arch = "wasm32"))]
         {
@@ -371,6 +389,32 @@ impl DiskCache {
         self.evict();
     }
 
+    /// The limit in effect: the setting, or less when the disk is short of free space.
+    pub fn limit_bytes(&self) -> u64 {
+        self.max_bytes().min(self.disk_cap.load(Ordering::Relaxed))
+    }
+
+    /// The cache's disk: `(total, available)` bytes, `None` = unknown. The cache leaves at least
+    /// 2 GB or 5% of the disk free, whichever is more (evicting when it must).
+    pub fn set_disk_space(&self, space: Option<(u64, u64)>) {
+        let cap = match space {
+            // (a disk reported as 0 bytes, such as an automount map, is unknown)
+            Some((total, available)) if total > 0 => {
+                let reserve = (2u64 << 30).max(total / 20);
+                let used = self.index.lock().map(|g| g.total()).unwrap_or_default();
+                // The cache's own files count as free: below the reserve it gives space back.
+                used.saturating_add(available).saturating_sub(reserve)
+            }
+            _ => u64::MAX,
+        };
+        self.disk_cap.store(cap, Ordering::Relaxed);
+        let limited = cap < self.max_bytes();
+        if self.space_limited.swap(limited, Ordering::Relaxed) != limited && limited {
+            log::warn!("disk cache at {}: little free disk space, limiting the cache to {} MB", self.folder().display(), cap >> 20);
+        }
+        self.evict();
+    }
+
     /// Layer buffers faster to render than this are not worth a disk write.
     pub fn set_min_layer_ms(&self, ms: u64) {
         self.min_layer_ms.store(ms, Ordering::Relaxed);
@@ -395,11 +439,13 @@ impl DiskCache {
             entries,
             bytes,
             max_bytes: self.max_bytes(),
+            limit_bytes: self.limit_bytes(),
             hits: self.hits.load(Ordering::Relaxed),
             misses: self.misses.load(Ordering::Relaxed),
             writes: self.writes.load(Ordering::Relaxed),
             evictions: self.evictions.load(Ordering::Relaxed),
             dropped: self.dropped.load(Ordering::Relaxed),
+            failed: self.failed.load(Ordering::Relaxed),
         }
     }
 
@@ -494,30 +540,44 @@ impl DiskCache {
         }
         let path = self.path(kind, key);
         let Some(parent) = path.parent() else { return };
-        if std::fs::create_dir_all(parent).is_err() {
+        if let Err(e) = std::fs::create_dir_all(parent) {
+            self.write_failed(&e);
             return;
         }
         let data = seal(kind, payload);
-        let n = self.tmp_counter.fetch_add(1, Ordering::Relaxed);
-        let tmp = parent.join(format!("{key:032x}.tmp.{}.{n}", std::process::id()));
-        if std::fs::write(&tmp, &data).is_err() {
-            let _ = std::fs::remove_file(&tmp);
+        // An entry that cannot fit would be evicted straight away.
+        if data.len() as u64 > self.limit_bytes() {
             return;
         }
-        if std::fs::rename(&tmp, &path).is_err() {
+        // Make room first, so the cache never exceeds its limit (or the free-space reserve).
+        self.evict_to(self.limit_bytes().saturating_sub(data.len() as u64));
+        let n = self.tmp_counter.fetch_add(1, Ordering::Relaxed);
+        let tmp = parent.join(format!("{key:032x}.tmp.{}.{n}", std::process::id()));
+        if let Err(e) = std::fs::write(&tmp, &data).and_then(|()| std::fs::rename(&tmp, &path)) {
             let _ = std::fs::remove_file(&tmp);
+            self.write_failed(&e);
             return;
         }
         self.writes.fetch_add(1, Ordering::Relaxed);
         if let Ok(mut g) = self.index.lock() {
             g.insert(kind, key, data.len() as u64);
         }
-        self.evict();
+    }
+
+    /// Count a failed write; the first one is logged (a full disk shouldn't go unnoticed).
+    fn write_failed(&self, e: &std::io::Error) {
+        if self.failed.fetch_add(1, Ordering::Relaxed) == 0 {
+            log::warn!("disk cache at {}: a write failed: {e}", self.folder().display());
+        }
     }
 
     /// Remove least recently used entries until the cache fits its limit.
     fn evict(&self) {
-        let max = self.max_bytes();
+        self.evict_to(self.limit_bytes());
+    }
+
+    /// Remove least recently used entries until the cache fits `max` bytes.
+    fn evict_to(&self, max: u64) {
         let victims = match self.index.lock() {
             Ok(mut g) => g.evict(max),
             Err(_) => return,
@@ -586,6 +646,15 @@ impl DiskCache {
 #[cfg(not(target_arch = "wasm32"))]
 fn writer(dc: std::sync::Weak<DiskCache>, q: Arc<(Mutex<Queue>, Condvar)>) {
     let (m, cv) = &*q;
+    // The eviction at open (a lower limit than the folder holds), off the opening thread;
+    // `busy` starts set, so `flush` waits for it.
+    if let Some(cache) = dc.upgrade() {
+        cache.evict();
+    }
+    if let Ok(mut g) = m.lock() {
+        g.busy = false;
+    }
+    cv.notify_all();
     loop {
         let job = {
             let Ok(mut g) = m.lock() else { return };
@@ -1030,9 +1099,9 @@ mod tests {
         let per = dc.stats().bytes / 6;
         // Touch 0 so it is the most recently used.
         assert!(dc.get_layer(0).is_some());
-        dc.set_max_bytes(per * 3 + per / 2);
+        dc.set_max_bytes(per * 3 + per * 3 / 4);
         let st = dc.stats();
-        assert!(st.bytes <= per * 3 + per / 2, "{st:?}");
+        assert!(st.bytes <= per * 3 + per * 3 / 4, "{st:?}");
         assert_eq!(st.entries, 3);
         assert!(dc.contains(Kind::Layer, 0), "recently used survives");
         assert!(!dc.contains(Kind::Layer, 1) && !dc.contains(Kind::Layer, 2) && !dc.contains(Kind::Layer, 3));
@@ -1042,7 +1111,69 @@ mod tests {
         assert_eq!(files, 3);
         // New writes keep evicting.
         dc.put_layer_now(99, &buf(9, 64, 64));
-        assert!(dc.stats().bytes <= per * 3 + per / 2);
+        assert!(dc.stats().bytes <= per * 3 + per * 3 / 4);
+    }
+
+    #[test]
+    fn eviction_goes_down_to_ninety_percent_in_lru_order() {
+        let mut ix = DiskIndex::default();
+        for k in 0..10u128 {
+            ix.insert(Kind::Layer, k, 100);
+        }
+        assert!(ix.touch(Kind::Layer, 0));
+        // Over 950: down to 855, least recently used first.
+        ix.insert(Kind::Layer, 10, 100);
+        assert_eq!(ix.evict(950), vec![(Kind::Layer, 1), (Kind::Layer, 2), (Kind::Layer, 3)]);
+        assert_eq!(ix.total(), 800);
+        // The slack absorbs the next write without another scan.
+        ix.insert(Kind::Layer, 11, 100);
+        assert!(ix.evict(950).is_empty());
+    }
+
+    #[test]
+    fn free_disk_space_caps_the_limit() {
+        let dir = tmpdir("space");
+        let dc = DiskCache::open(&dir, 1 << 30).unwrap();
+        for k in 0..4u128 {
+            dc.put_layer_now(k, &buf(k as u32, 64, 64));
+        }
+        let used = dc.stats().bytes;
+        // Unknown space: the setting alone.
+        dc.set_disk_space(None);
+        assert_eq!(dc.stats().limit_bytes, 1 << 30);
+        // A disk reported as 0 bytes is unknown.
+        dc.set_disk_space(Some((0, 0)));
+        assert_eq!(dc.stats().limit_bytes, 1 << 30);
+        // 100 GB disk, 5 GB reserved, exactly 5 GB free: the cache may not grow.
+        dc.set_disk_space(Some((100 << 30, 5 << 30)));
+        let st = dc.stats();
+        assert_eq!((st.max_bytes, st.limit_bytes), (1 << 30, used));
+        dc.put_layer_now(9, &buf(9, 64, 64));
+        let st = dc.stats();
+        assert!(st.bytes <= st.limit_bytes && st.bytes <= used - used / 10 && st.evictions > 0, "{st:?}");
+        assert!(dc.contains(Kind::Layer, 9), "the new entry is the most recently used");
+        // Below the reserve the cache gives its space back, and skips writes that can't fit.
+        dc.set_disk_space(Some((100 << 30, 4 << 30)));
+        dc.put_layer_now(10, &buf(10, 64, 64));
+        let st = dc.stats();
+        assert_eq!((st.limit_bytes, st.entries, st.bytes), (0, 0, 0), "{st:?}");
+        // Plenty of space again: back to the setting.
+        dc.set_disk_space(Some((100 << 30, 50 << 30)));
+        assert_eq!(dc.stats().limit_bytes, 1 << 30);
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn failed_writes_are_counted() {
+        let dir = tmpdir("failed");
+        let dc = DiskCache::open(&dir, 1 << 30).unwrap();
+        // A file where the layers folder should be: every layer write fails.
+        std::fs::write(dir.join(VERSION).join(Kind::Layer.dir()), b"x").unwrap();
+        dc.put_layer_now(1, &buf(1, 8, 8));
+        dc.put_layer_now(2, &buf(2, 8, 8));
+        let st = dc.stats();
+        assert_eq!((st.failed, st.writes, st.entries), (2, 0, 0));
+        let _ = std::fs::remove_dir_all(&dir);
     }
 
     fn walk(d: &Path) -> usize {
diff --git a/crates/render/src/footage.rs b/crates/render/src/footage.rs
new file mode 100644
index 000000000..04dd706db
--- /dev/null
+++ b/crates/render/src/footage.rs
@@ -0,0 +1,178 @@
+use super::{Arc, AtomicBool, Footage, Image, ItemId, Ordering, Tick};
+
+/// How a [`FootageSource`] hands over float footage (OpenEXR, float TIFF), whose values are
+/// linear light: encoded with a curve, as the compositor takes footage, or as stored. Other
+/// footage is decoded the same way whatever it says. Interpret Footage ▸ Preserve RGB always
+/// reads the values as stored.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash)]
+pub enum FloatCurve {
+    /// The sRGB curve (managed projects, and Working Gamma 2.2).
+    #[default]
+    Srgb,
+    /// A pure 2.4 power curve (no working space, Working Gamma 2.4).
+    Gamma24,
+    /// The linear values as stored (Interpret As Linear Light encodes them afterwards).
+    Linear,
+}
+
+/// Supplies decoded footage frames (implemented by the media layer).
+pub trait FootageSource: Send + Sync {
+    /// The frame of `item` at source time `t`, straight from the file (any size).
+    fn frame(&self, item: ItemId, footage: &Footage, t: Tick) -> Option<Arc<Image>>;
+    /// [`FootageSource::frame`] for a render that shows it at `width` × `height`, at most half its
+    /// size: either that frame or, when the source can make it more cheaply than the whole frame
+    /// (movies, see `effectcraft-media`), the frame already resampled to that size as
+    /// [`effectcraft_raster::resample`] would.
+    fn frame_at_size(&self, item: ItemId, footage: &Footage, t: Tick, _width: u32, _height: u32) -> Option<Arc<Image>> {
+        self.frame(item, footage, t)
+    }
+    /// [`FootageSource::frame`] (`size: None`) or [`FootageSource::frame_at_size`] with float
+    /// footage handed over as `float` says ([`FootageSource::frame`] uses [`FloatCurve::Srgb`]).
+    /// Sources without float footage can leave the default, which ignores `float`.
+    fn frame_with(&self, item: ItemId, footage: &Footage, t: Tick, size: Option<(u32, u32)>, float: FloatCurve) -> Option<Arc<Image>> {
+        let _ = float;
+        match size {
+            Some((w, h)) => self.frame_at_size(item, footage, t, w, h),
+            None => self.frame(item, footage, t),
+        }
+    }
+    /// `frames` interleaved stereo sample frames of `item`'s audio from source time `t` at
+    /// `rate` Hz (`None` when unavailable). The first sample is `t.to_units_floor(rate)`;
+    /// a sample boundary uses the earliest representable tick that selects that sample.
+    fn audio(&self, _item: ItemId, _footage: &Footage, _t: Tick, _frames: usize, _rate: u32) -> Option<Vec<f32>> {
+        None
+    }
+    /// Auxiliary 3D channels of `item` at source time `t` (multi-layer OpenEXR: depth, IDs,
+    /// Cryptomatte, any named channel), with `scale` relative to the file's pixels. `None` when
+    /// the footage has none.
+    fn aux(&self, _item: ItemId, _footage: &Footage, _t: Tick) -> Option<Arc<effectcraft_raster::AuxChannels>> {
+        None
+    }
+    /// The parsed 3D model of a [`effectcraft_project::FootageKind::Model`] item (Advanced 3D).
+    fn model(&self, _item: ItemId, _footage: &Footage) -> Option<Arc<effectcraft_model::Model>> {
+        None
+    }
+    /// Set the decoded-frame cache budget in bytes (Settings ▸ Memory & CPU); sources without
+    /// a cache ignore it.
+    fn set_cache_budget(&self, _bytes: usize) {}
+    /// Drop the decoded frames it keeps (Edit ▸ Purge ▸ All Memory / Image Cache Memory): the
+    /// next reads decode again. Sources without a cache ignore it.
+    fn purge(&self) {}
+    /// The file at `path` changed on disk (Reload Footage): drop what it keeps of it (decoded
+    /// frames, open decoders, parsed models), so the next reads see the new contents. Sources
+    /// without a cache ignore it.
+    fn forget(&self, _path: &str) {}
+    /// Settings ▸ Disk ▸ Conformed Audio Folder: where decoded audio is kept between reads
+    /// (`None` = off); sources that don't decode audio ignore it.
+    fn set_conform_folder(&self, _folder: Option<std::path::PathBuf>) {}
+    /// The decoded-frame cache budget in bytes, if the source has a cache.
+    fn cache_budget(&self) -> Option<usize> {
+        None
+    }
+    /// Vector footage (SVG) rasterised at `scale` × its pixel size, for Continuously Rasterize.
+    /// `None` when the footage is not vector or cannot be read.
+    fn vector_frame(&self, _item: ItemId, _footage: &Footage, _scale: f64) -> Option<Arc<Image>> {
+        None
+    }
+    /// Run `f`, which reads frames from this source, as work that can be called off: once
+    /// `cancel` is set, long decodes it starts (a movie seeking back to a keyframe and decoding
+    /// forward) stop early and their frames come back `None`. Sources that can't stop a decode
+    /// just run `f`. See [`CancellableFootage`].
+    fn cancellable(&self, _cancel: &Arc<AtomicBool>, f: &mut dyn FnMut()) {
+        f()
+    }
+    /// Reads through this source have been called off: frames may have come back `None` that
+    /// exist, so what was made from them must not be kept.
+    fn called_off(&self) -> bool {
+        false
+    }
+    /// Why `footage` shows no picture although its file is there: a read of it failed because
+    /// no decoder handles its codec, profile, chroma format or bit depth, or the stream is damaged
+    /// (e.g. "H.264 (High 4:2:2) isn't supported by the built-in decoder: ..."). `None` while it
+    /// decodes, and for sources that don't track failures. Stays set until the file is forgotten.
+    fn problem(&self, _footage: &Footage) -> Option<String> {
+        None
+    }
+}
+
+/// A render's view of a [`FootageSource`] whose frame reads can be called off with `cancel`
+/// (a viewer frame nobody waits for any more, #329). Every read goes through
+/// [`FootageSource::cancellable`] on its own, so reads made for this render on another thread
+/// (a parallel loop) answer to this render's flag, and reads for other renders never do.
+pub struct CancellableFootage<'a> {
+    pub inner: &'a dyn FootageSource,
+    pub cancel: Arc<AtomicBool>,
+}
+
+impl CancellableFootage<'_> {
+    fn read<R>(&self, f: impl FnOnce() -> Option<R>) -> Option<R> {
+        if self.cancel.load(Ordering::Relaxed) {
+            return None;
+        }
+        let (mut f, mut out) = (Some(f), None);
+        self.inner.cancellable(&self.cancel, &mut || out = f.take().and_then(|f| f()));
+        out
+    }
+}
+
+impl FootageSource for CancellableFootage<'_> {
+    fn frame(&self, item: ItemId, footage: &Footage, t: Tick) -> Option<Arc<Image>> {
+        self.read(|| self.inner.frame(item, footage, t))
+    }
+    fn frame_at_size(&self, item: ItemId, footage: &Footage, t: Tick, width: u32, height: u32) -> Option<Arc<Image>> {
+        self.read(|| self.inner.frame_at_size(item, footage, t, width, height))
+    }
+    fn audio(&self, item: ItemId, footage: &Footage, t: Tick, frames: usize, rate: u32) -> Option<Vec<f32>> {
+        self.inner.audio(item, footage, t, frames, rate)
+    }
+    fn aux(&self, item: ItemId, footage: &Footage, t: Tick) -> Option<Arc<effectcraft_raster::AuxChannels>> {
+        self.inner.aux(item, footage, t)
+    }
+    fn model(&self, item: ItemId, footage: &Footage) -> Option<Arc<effectcraft_model::Model>> {
+        self.inner.model(item, footage)
+    }
+    fn set_cache_budget(&self, bytes: usize) {
+        self.inner.set_cache_budget(bytes)
+    }
+    fn purge(&self) {
+        self.inner.purge()
+    }
+    fn forget(&self, path: &str) {
+        self.inner.forget(path)
+    }
+    fn set_conform_folder(&self, folder: Option<std::path::PathBuf>) {
+        self.inner.set_conform_folder(folder)
+    }
+    fn cache_budget(&self) -> Option<usize> {
+        self.inner.cache_budget()
+    }
+    fn vector_frame(&self, item: ItemId, footage: &Footage, scale: f64) -> Option<Arc<Image>> {
+        self.inner.vector_frame(item, footage, scale)
+    }
+    fn cancellable(&self, cancel: &Arc<AtomicBool>, f: &mut dyn FnMut()) {
+        self.inner.cancellable(cancel, f)
+    }
+    fn called_off(&self) -> bool {
+        self.cancel.load(Ordering::Relaxed) || self.inner.called_off()
+    }
+    fn problem(&self, footage: &Footage) -> Option<String> {
+        self.inner.problem(footage)
+    }
+    fn frame_with(&self, item: ItemId, footage: &Footage, t: Tick, size: Option<(u32, u32)>, float: FloatCurve) -> Option<Arc<Image>> {
+        self.read(|| self.inner.frame_with(item, footage, t, size, float))
+    }
+}
+
+/// Footage that can be rasterised at any scale (SVG).
+pub fn is_vector_footage(f: &Footage) -> bool {
+    matches!(f.codec.as_str(), "SVG" | "PDF" | "AI" | "EPS")
+}
+
+/// No footage available (renders footage layers as transparent).
+pub struct NoFootage;
+
+impl FootageSource for NoFootage {
+    fn frame(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<Image>> {
+        None
+    }
+}
diff --git a/crates/render/src/frames.rs b/crates/render/src/frames.rs
new file mode 100644
index 000000000..7dd0fc0de
--- /dev/null
+++ b/crates/render/src/frames.rs
@@ -0,0 +1,144 @@
+use super::footage::NoFootage;
+use super::opts::RenderOpts;
+use super::{EvalCtx, Footage, FrameBlend, FrameRate, Image, ItemId, Layer, LayerSource, Project, Renderer, TICKS_PER_SECOND, Tick, shapes, source_size, text};
+
+/// The layer's frame blending mode, if the comp's Enable Frame Blending switch is on.
+/// One field of an interlaced frame as a full frame: the field's lines (`parity` 0 = even /
+/// upper, 1 = odd / lower) kept, the other lines interpolated from their neighbours.
+pub fn field_frame(img: &Image, parity: usize) -> Image {
+    let (w, h) = (img.width as usize, img.height as usize);
+    let mut out = img.clone();
+    if h < 2 {
+        return out;
+    }
+    for y in 0..h {
+        if y % 2 == parity {
+            continue;
+        }
+        let above = y.checked_sub(1);
+        let below = (y + 1 < h).then_some(y + 1);
+        for x in 0..w {
+            let px = match (above, below) {
+                (Some(a), Some(b)) => {
+                    let (p, q) = (img.data[a * w + x], img.data[b * w + x]);
+                    [(p[0] + q[0]) * 0.5, (p[1] + q[1]) * 0.5, (p[2] + q[2]) * 0.5, (p[3] + q[3]) * 0.5]
+                }
+                (Some(a), None) => img.data[a * w + x],
+                (None, Some(b)) => img.data[b * w + x],
+                (None, None) => img.data[y * w + x],
+            };
+            out.data[y * w + x] = px;
+        }
+    }
+    out
+}
+
+/// Interpret Footage ▸ Invert Alpha and Interpret As Linear Light on decoded (premultiplied)
+/// pixels; linear light is encoded in `space` ([`color::Pipe::linear_footage_space`]).
+pub fn interpret_pixels(img: &Image, f: &Footage, space: effectcraft_color::ColorSpace) -> Image {
+    let linear = f.linear_light_applies();
+    if !f.invert_alpha && !linear {
+        return img.clone();
+    }
+    let mut out = img.clone();
+    for p in out.data.iter_mut() {
+        let a = p[3];
+        let mut c = if a > 1e-6 { [p[0] / a, p[1] / a, p[2] / a] } else { [0.0; 3] };
+        if linear {
+            // The file's values are linear light: encode them like the rest of the footage.
+            c = c.map(|v| space.encode(v));
+        }
+        let a = if f.invert_alpha { 1.0 - a } else { a };
+        *p = [c[0] * a, c[1] * a, c[2] * a, a];
+    }
+    out
+}
+
+pub(crate) fn frame_blend_mode(ctx: &EvalCtx, layer: &Layer) -> FrameBlend {
+    if ctx.comp.enable_frame_blending { layer.switches.frame_blend } else { FrameBlend::Off }
+}
+
+/// Position of source time `t` among frames at `rate`: the frame at or before `t` and the
+/// fraction (0..1) of the way to the next frame. Exact (integer tick arithmetic), so frames that
+/// line up exactly report a fraction of 0.
+pub fn frame_position(t: Tick, rate: FrameRate) -> (i64, f64) {
+    let num = t.0 as i128 * rate.num as i128;
+    let den = TICKS_PER_SECOND as i128 * rate.den as i128;
+    (num.div_euclid(den) as i64, num.rem_euclid(den) as f64 / den as f64)
+}
+
+/// Blend two neighbouring frames `w` of the way from `a` to `b`: a cross-fade (Frame Mix) or a
+/// motion-compensated interpolation (Pixel Motion).
+pub fn blend_frames(mode: FrameBlend, a: &Image, b: &Image, w: f32) -> Image {
+    match mode {
+        FrameBlend::PixelMotion => effectcraft_raster::flow::interpolate(a, b, w),
+        _ => effectcraft_raster::flow::mix(a, b, w),
+    }
+}
+
+/// Convenience: render one frame of a comp with no footage source.
+/// Adaptive motion-blur sample count for a layer whose corners travel `travel` output pixels
+/// during the shutter: one sample per pixel, clamped to Samples Per Frame … Adaptive Sample Limit.
+pub fn adaptive_samples(travel: f64, per_frame: u32, limit: u32) -> usize {
+    let lo = per_frame.clamp(2, 64) as f64;
+    let hi = (limit.clamp(16, 256) as f64).max(lo);
+    travel.ceil().clamp(lo, hi) as usize
+}
+
+/// A region of interest `[x, y, w, h]` lies within a `w`×`h` comp frame.
+pub fn roi_inside(r: [f64; 4], w: u32, h: u32) -> bool {
+    r[0] >= 0.0 && r[1] >= 0.0 && r[0] + r[2] <= w as f64 + 1e-6 && r[1] + r[3] <= h as f64 + 1e-6
+}
+
+/// The Extended Viewer's region of interest: the comp frame grown by `margin` × its size on every
+/// side (`margin` = 1 shows a pasteboard one comp wide around the frame), intersected with the
+/// `visible` comp-space rectangle `[x0, y0, x1, y1]` and snapped outward to whole 16 px steps from the frame edges
+/// so panning re-renders rarely. `None` when the visible area lies inside the frame.
+pub fn extended_region(w: u32, h: u32, visible: [f64; 4], margin: f64) -> Option<[f64; 4]> {
+    let (w, h) = (w as f64, h as f64);
+    let (mx, my) = (w * margin, h * margin);
+    let snap_lo = |v: f64| (v / 16.0).floor() * 16.0;
+    let snap_hi = |v: f64| (v / 16.0).ceil() * 16.0;
+    let x0 = snap_lo(visible[0].max(-mx)).min(0.0);
+    let y0 = snap_lo(visible[1].max(-my)).min(0.0);
+    let x1 = w + snap_hi(visible[2].min(w + mx) - w).max(0.0);
+    let y1 = h + snap_hi(visible[3].min(h + my) - h).max(0.0);
+    if x0 >= 0.0 && y0 >= 0.0 && x1 <= w && y1 <= h {
+        return None;
+    }
+    Some([x0, y0, x1 - x0, y1 - y0])
+}
+
+/// The size of a `width` x `height` comp frame rendered at `scale` (both compositors, and the
+/// frame size Composition Settings shows for a Resolution).
+pub fn frame_size(width: u32, height: u32, scale: f64) -> (u32, u32) {
+    (((width as f64 * scale).round() as u32).max(1), ((height as f64 * scale).round() as u32).max(1))
+}
+
+pub fn render_frame(project: &Project, comp: ItemId, t: Tick, scale: f64) -> Image {
+    Renderer::new(project, &NoFootage, RenderOpts { scale, ..Default::default() }).comp_frame(comp, t)
+}
+
+/// Layer-space bounds `[x0, y0, x1, y1]` of a layer's content at the context time (source size
+/// for solids/footage/precomps, glyph bounds for text, painted bounds for shapes). Used for viewer
+/// handles and hit testing.
+pub fn content_bounds(ctx: &EvalCtx, layer: &effectcraft_project::Layer) -> Option<[f64; 4]> {
+    match &layer.source {
+        LayerSource::Text => {
+            let glyphs = text::glyph_paths(ctx, layer);
+            let paths: Vec<_> = glyphs.into_iter().map(|g| g.0).collect();
+            effectcraft_path::bounds(&paths).map(|r| [r.x0, r.y0, r.x1, r.y1])
+        }
+        LayerSource::Shape => layer.props.sub("contents").and_then(|c| shapes::content_bounds(ctx, layer, c)).map(|r| [r.x0, r.y0, r.x1, r.y1]),
+        LayerSource::Camera | LayerSource::Light { .. } => None,
+        _ => {
+            let (w, h) = source_size(ctx.project, layer);
+            (w > 0 && h > 0).then_some([0.0, 0.0, w as f64, h as f64])
+        }
+    }
+}
+
+/// A mask/shape path as a kurbo path (for drawing overlays).
+pub fn kurbo_path(sp: &effectcraft_keyframe::ShapePath) -> kurbo::BezPath {
+    effectcraft_path::to_kurbo(sp)
+}
diff --git a/crates/render/src/fx_host.rs b/crates/render/src/fx_host.rs
new file mode 100644
index 000000000..8366cf7c0
--- /dev/null
+++ b/crates/render/src/fx_host.rs
@@ -0,0 +1,157 @@
+use super::{Arc, Buf, EffectHost, EvalCtx, ItemKind, Layer, LayerPixels, LayerSource, Params, Renderer, Tick, three_d};
+
+/// Layer parameters and audio for effects (see [`effectcraft_effects::EffectHost`]). What it
+/// hands out is in effect space (see [`effect_bounds`]): the other layer's for its pixels, the
+/// running layer's for its own frames and the comp scene.
+pub(crate) struct FxHost<'r, 'a, 'c> {
+    pub(crate) r: &'r Renderer<'a>,
+    pub(crate) ctx: &'c EvalCtx<'a>,
+    pub(crate) layer: &'c Layer,
+    /// Where the stack's effect space starts in layer coordinates (zero on adjustment layers,
+    /// whose effects run on the comp below).
+    pub(crate) origin: [f64; 2],
+    /// Index of the effect being rendered (bounds `self_at` to effects before it).
+    pub(crate) index: usize,
+    pub(crate) original: Option<&'c Buf>,
+}
+
+impl FxHost<'_, '_, '_> {
+    /// Another layer's pixels for a layer parameter, in its effect space; `layer_space`: `buf`
+    /// is still in layer space (its source or its content).
+    fn pixels(&self, other: &Layer, mut buf: Buf, layer_space: bool) -> LayerPixels {
+        let (size, origin) = self.ctx.effect_bounds(other);
+        if layer_space {
+            buf.rebase(origin);
+        }
+        LayerPixels { buf, size }
+    }
+}
+
+/// The comp's camera and first light relative to `layer`, in its layer pixels (see
+/// [`EffectHost::comp_scene`]): the comp camera's view of the layer (as if 3D at its transform),
+/// brought back into the layer's own pixel grid through the inverse of how the layer itself
+/// composites.
+pub(crate) fn comp_scene(ctx: &EvalCtx, layer: &Layer) -> Option<effectcraft_effects::CompScene> {
+    let world = ctx.world_matrix(layer);
+    let (cam, _, _) = ctx.camera();
+    let p = (cam * world).0;
+    let back = ctx.layer_to_comp(layer).0.inverse()?.0;
+    let rows = [p[0], p[1], p[3]];
+    let camera: [[f64; 4]; 3] = std::array::from_fn(|i| std::array::from_fn(|j| (0..3).map(|k| back[i][k] * rows[k][j]).sum()));
+    let inv = world.inverse();
+    let light = three_d::light::lights_at(ctx).first().and_then(|l| {
+        let inv = inv.as_ref()?;
+        let pos = inv.apply(l.pos);
+        let dir = inv.apply_vec(l.dir);
+        let len = (dir.x * dir.x + dir.y * dir.y + dir.z * dir.z).sqrt().max(1e-12);
+        let kind = match l.kind {
+            effectcraft_project::LightKind::Parallel => 0,
+            effectcraft_project::LightKind::Ambient => 2,
+            _ => 1,
+        };
+        Some(effectcraft_effects::CompLight { pos: [pos.x, pos.y, pos.z], dir: [dir.x / len, dir.y / len, dir.z / len], color: l.color, kind })
+    });
+    let camera_layer = ctx.comp.active_camera(ctx.time).is_some();
+    Some(effectcraft_effects::CompScene { camera: Some(camera), camera_layer, light })
+}
+
+/// Nesting limit for effects that render layers (other layers, other times).
+pub(crate) const MAX_FX_DEPTH: usize = 8;
+
+impl EffectHost for FxHost<'_, '_, '_> {
+    fn original(&self) -> Option<&Buf> {
+        self.original
+    }
+
+    fn particles(&self) -> Option<&dyn effectcraft_effects::psim::ParticleSim> {
+        self.r.active_accel().and_then(|a| a.particles())
+    }
+    fn layer(&self, id: u64, masks_and_effects: bool) -> Option<LayerPixels> {
+        let other = self.ctx.layer(effectcraft_project::LayerId(id))?;
+        if (other.id == self.layer.id && masks_and_effects) || self.r.depth > MAX_FX_DEPTH {
+            return None;
+        }
+        let sub = self.r.nested();
+        // The cached layer buffer is shared; effects get their own copy.
+        let buf = if masks_and_effects { (*sub.content_buf(self.ctx, other)?).clone() } else { sub.source(self.ctx, other)? };
+        Some(self.pixels(other, buf, true))
+    }
+
+    fn layer_masks(&self, id: u64) -> Option<LayerPixels> {
+        let other = self.ctx.layer(effectcraft_project::LayerId(id))?;
+        if self.r.depth > MAX_FX_DEPTH {
+            return None;
+        }
+        let sub = self.r.nested();
+        let buf = (*sub.layer_input(self.ctx, other, 0)?).clone();
+        Some(self.pixels(other, buf, false))
+    }
+
+    fn audio(&self, id: u64, start: f64, frames: usize, rate: u32) -> Option<Vec<f32>> {
+        let other = self.ctx.layer(effectcraft_project::LayerId(id))?;
+        let LayerSource::Footage { item } = &other.source else { return None };
+        let ItemKind::Footage(f) = &self.r.project.item(*item)?.kind else { return None };
+        if !f.has_audio {
+            return None;
+        }
+        let st = other.layer_time(Tick::from_seconds_f64(start));
+        self.r.footage.audio(*item, f, st, frames, rate)
+    }
+
+    fn self_at(&self, layer_time: f64, effects: usize) -> Option<Buf> {
+        if self.r.depth > MAX_FX_DEPTH || self.layer.switches.adjustment {
+            return None;
+        }
+        let n = effects.min(self.index);
+        let t = self.layer.comp_time(Tick::from_seconds_f64(layer_time));
+        let sub = self.r.nested();
+        sub.layer_input(&self.ctx.at(t), self.layer, n).map(|b| (*b).clone())
+    }
+
+    fn aux(&self) -> Option<Arc<effectcraft_raster::AuxChannels>> {
+        self.r.layer_aux(self.ctx, self.layer)
+    }
+
+    fn params_at(&self, layer_time: f64) -> Option<Params> {
+        let g = self.layer.effects()?.groups().nth(self.index)?;
+        let ctx = self.ctx.at(self.layer.comp_time(Tick::from_seconds_f64(layer_time)));
+        Some(effectcraft_effects::flatten_params(g, &mut |pr| ctx.value(self.layer, pr)))
+    }
+
+    fn comp_scene(&self) -> Option<effectcraft_effects::CompScene> {
+        Some(comp_scene(self.ctx, self.layer)?.rebased(self.origin))
+    }
+
+    fn layer_at(&self, id: u64, comp_time: f64, masks_and_effects: bool) -> Option<LayerPixels> {
+        let other = self.ctx.layer(effectcraft_project::LayerId(id))?;
+        if (other.id == self.layer.id && masks_and_effects) || !comp_time.is_finite() || self.r.depth > MAX_FX_DEPTH {
+            return None;
+        }
+        let ctx = self.ctx.at(Tick::from_seconds_f64(comp_time));
+        let sub = self.r.nested();
+        Some(if masks_and_effects {
+            self.pixels(other, (*sub.content_buf(&ctx, other)?).clone(), true)
+        } else if other.id == self.layer.id {
+            self.pixels(other, sub.source(&ctx, other)?, true)
+        } else {
+            // Preserve other-layer reads: time effects historically see source + masks.
+            self.pixels(other, (*sub.layer_input(&ctx, other, 0)?).clone(), false)
+        })
+    }
+}
+
+/// The Essential Properties overrides of a precomp layer, evaluated at the context time.
+pub fn essential_overrides(ctx: &EvalCtx, layer: &Layer) -> Vec<effectcraft_project::essential::Override> {
+    use effectcraft_project::essential;
+    let over = essential::overridden(layer);
+    let Some(g) = essential::group(layer).filter(|_| !over.is_empty()) else { return vec![] };
+    let mut out = vec![];
+    g.walk("", &mut |_, p| {
+        if over.contains(&p.uid)
+            && let Some(control) = essential::control_of(&p.match_id)
+        {
+            out.push(essential::Override { control, value: ctx.value(layer, p) });
+        }
+    });
+    out
+}
diff --git a/crates/render/src/layers.rs b/crates/render/src/layers.rs
new file mode 100644
index 000000000..cac2add43
--- /dev/null
+++ b/crates/render/src/layers.rs
@@ -0,0 +1,601 @@
+use super::frames::adaptive_samples;
+use super::opts::{LayerTiming, Through};
+use super::{
+    Arc, BlendMode, Buf, Comp, EvalCtx, Image, IndexedParallelIterator, IntoParallelRefIterator, IntoParallelRefMutIterator, Layer, LayerSource, Mat3,
+    MatteKind, ParallelIterator, Quality, Region, Renderer, Sampling, Tick, WarpOpts, cache, color, composite_warp_changed, masks, source_size, styles, vec2,
+};
+
+/// Blend policy for placing a layer, including optional output-depth quantization.
+struct PlacementBlend {
+    mode: BlendMode,
+    opacity: f32,
+    quantize: Option<f32>,
+}
+
+/// A motion-blur shutter: the comp's, or for a collapsed precomp's layers the outermost
+/// containing comp's (they are drawn into its frames).
+#[derive(Clone, Copy)]
+struct Shutter {
+    /// Shutter angle and phase as fractions of a frame.
+    angle: f64,
+    phase: f64,
+    /// Frame duration (seconds).
+    frame: f64,
+    /// Samples Per Frame and Adaptive Sample Limit.
+    samples: u32,
+    limit: u32,
+}
+
+impl Shutter {
+    /// Seconds from the frame time to sub-sample `i` of `n`, spread over the open shutter.
+    fn offset(&self, i: usize, n: usize) -> f64 {
+        let f = if n > 1 { i as f64 / (n - 1) as f64 } else { 0.0 };
+        (self.phase + self.angle * f) * self.frame
+    }
+}
+
+impl<'a> Renderer<'a> {
+    /// The layer with its styles: exterior passes and body (cached per pass).
+    pub(crate) fn styled(&self, ctx: &EvalCtx, layer: &Layer, mut timing: Option<&mut LayerTiming>) -> Option<StyledLayer> {
+        let (content, ckey) = self.content_buf_timed(ctx, layer, timing.as_deref_mut())?;
+        if !styles::active(ctx, layer) {
+            return Some(StyledLayer { passes: vec![], body: content.clone(), content, key: ckey, ckey, plain: true });
+        }
+        let modes = styles::pass_modes(ctx, layer);
+        let key = ckey.map(|k| cache::styles_key(ctx, layer, k));
+        if let (Some(c), Some(k)) = (self.cache, key)
+            && let Some(body) = c.get(k)
+        {
+            let passes: Option<Vec<_>> = modes.iter().enumerate().map(|(i, m)| c.get(cache::derive(k, i as u64 + 1)).map(|b| (b, *m))).collect();
+            if let Some(passes) = passes {
+                return Some(StyledLayer { passes, body, content, key, ckey, plain: false });
+            }
+        }
+        let t0 = web_time::Instant::now();
+        let size = source_size(self.project, layer);
+        let layer_size = if size.0 == 0 { [ctx.comp.width as f64, ctx.comp.height as f64] } else { [size.0 as f64, size.1 as f64] };
+        let st = styles::render(ctx, layer, &content, layer_size);
+        if let Some(t) = timing {
+            t.cached = false;
+            t.effects.push(("layerStyles".into(), t0.elapsed().as_secs_f64() * 1e3));
+        }
+        let mut body = Arc::new(st.body);
+        let mut passes: Vec<_> = st.passes.into_iter().map(|(b, m)| (Arc::new(b), m)).collect();
+        // The buffers the cache keeps (another worker's, if it kept them first).
+        if let (Some(c), Some(k)) = (self.cache_to_keep(), key) {
+            body = c.insert(k, body);
+            for (i, (b, _)) in passes.iter_mut().enumerate() {
+                *b = c.insert(cache::derive(k, i as u64 + 1), b.clone());
+            }
+        }
+        Some(StyledLayer { passes, body, content, key, ckey, plain: false })
+    }
+
+    /// The styled layer's buffers in the blending space.
+    pub(crate) fn styled_to_blend(&self, st: StyledLayer) -> StyledLayer {
+        if self.pipe.to_blend().is_none() {
+            return st;
+        }
+        let body = self.to_blend(st.body, st.key);
+        let content = if st.plain { body.clone() } else { self.to_blend(st.content, st.ckey) };
+        let passes = st.passes.into_iter().enumerate().map(|(i, (b, m))| (self.to_blend(b, st.key.map(|k| cache::derive(k, i as u64 + 1))), m)).collect();
+        StyledLayer { passes, body, content, ..st }
+    }
+
+    pub(crate) fn sampling(&self, layer: &Layer) -> effectcraft_raster::Sampling {
+        if self.quality(layer) == Quality::Draft {
+            // Draft quality: no interpolation (nearest neighbour), as After Effects' Draft.
+            effectcraft_raster::Sampling::Nearest
+        } else if self.opts.draft {
+            effectcraft_raster::Sampling::Bilinear
+        } else if layer.switches.sampling == Sampling::Bicubic {
+            effectcraft_raster::Sampling::Bicubic
+        } else {
+            effectcraft_raster::Sampling::Bilinear
+        }
+    }
+
+    /// The region of interest of a top-level 2D frame: (x, y) offset of the output in output
+    /// pixels and its size. `None` renders the whole comp (no ROI, or a nested comp).
+    pub(crate) fn roi_offset(&self) -> Option<(f64, f64, u32, u32)> {
+        let r = self.opts.roi.filter(|_| self.top)?;
+        let s = self.opts.scale;
+        if r[2] <= 0.0 || r[3] <= 0.0 {
+            return None;
+        }
+        Some(((r[0] * s).round(), (r[1] * s).round(), ((r[2] * s).round() as u32).max(1), ((r[3] * s).round() as u32).max(1)))
+    }
+
+    /// The region of interest's offset in output pixels for 3D projection (0 without one).
+    pub(crate) fn out_offset(&self) -> (f64, f64) {
+        self.roi_offset().map_or((0.0, 0.0), |(x, y, _, _)| (x, y))
+    }
+
+    /// Scaled comp pixel → output pixel: the region of interest's offset.
+    fn out_matrix(&self) -> Mat3 {
+        match self.roi_offset() {
+            Some((x, y, _, _)) => Mat3::translate(vec2(-x, -y)),
+            None => Mat3::IDENTITY,
+        }
+    }
+
+    /// Buffer pixel → output pixel matrix for the layer at the context time.
+    fn buf_matrix(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf) -> Mat3 {
+        let (l2c, _) = ctx.layer_to_comp(layer);
+        self.place_matrix(self.outer.map_or(l2c, |o| o * l2c), buf)
+    }
+
+    /// Buffer pixel → output pixel matrix for a layer → (top-level) comp matrix.
+    fn place_matrix(&self, l2c: Mat3, buf: &Buf) -> Mat3 {
+        let s = self.opts.scale;
+        self.out_matrix()
+            * Mat3::scale(vec2(s, s))
+            * l2c
+            * Mat3::scale(vec2(1.0 / buf.scale, 1.0 / buf.scale))
+            * Mat3::translate(vec2(-buf.offset[0], -buf.offset[1]))
+    }
+
+    /// The collapsed precomp layers this comp is drawn through, outermost first.
+    fn links(&self) -> impl Iterator<Item = &Through<'a>> {
+        self.through.iter().map_while(Option::as_ref)
+    }
+
+    /// The shutter of a layer's motion blur: its comp's, or for a collapsed precomp's layers the
+    /// outermost containing comp's.
+    fn shutter(&self, ctx: &EvalCtx) -> Shutter {
+        let c: &Comp = match self.links().next() {
+            Some(l) => l.comp,
+            None => ctx.comp,
+        };
+        Shutter {
+            angle: c.shutter_angle / 360.0,
+            phase: c.shutter_phase / 360.0,
+            frame: c.frame_duration().seconds(),
+            samples: c.motion_blur_samples,
+            limit: c.motion_blur_adaptive_limit,
+        }
+    }
+
+    /// Whether a layer moves within the shutter: its own motion blur, or that of a collapsed
+    /// precomp layer it is drawn through.
+    fn blurred(&self, ctx: &EvalCtx, layer: &Layer) -> bool {
+        self.mb_on(ctx, layer) || (!self.through_lost && self.links().any(|l| l.blur))
+    }
+
+    /// The collapsed precomps' matrix (nested comp → the frame's comp) and the nested comp's time
+    /// `dt` seconds into the outermost comp's shutter: each precomp layer moves if it is motion
+    /// blurred, and times map down through each one (stretch, time remapping).
+    fn outer_at(&self, ctx: &EvalCtx, dt: f64) -> (Option<Mat3>, Tick) {
+        let shift = Tick::from_seconds_f64(dt);
+        let mut outer: Option<Mat3> = None;
+        let mut t: Option<Tick> = None;
+        for l in self.links() {
+            let at = EvalCtx { comp_id: l.comp_id, comp: l.comp, time: t.unwrap_or(l.time + shift), ..*ctx };
+            let (m, _) = if l.blur { at.layer_to_comp(l.layer) } else { EvalCtx { time: l.time, ..at }.layer_to_comp(l.layer) };
+            outer = Some(outer.map_or(m, |o| o * m));
+            t = Some(at.nested_time(l.layer));
+        }
+        (outer, t.unwrap_or(ctx.time + shift))
+    }
+
+    /// [`Self::buf_matrix`] for the motion-blur sub-sample `dt` seconds into the shutter: the
+    /// layer moves if it is motion blurred, the collapsed precomps above it if theirs are.
+    fn buf_matrix_at(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf, dt: f64) -> Mat3 {
+        if self.through_lost || self.links().next().is_none() {
+            return self.buf_matrix(&ctx.at(ctx.time + Tick::from_seconds_f64(dt)), layer, buf);
+        }
+        let (outer, t) = self.outer_at(ctx, dt);
+        let lctx = if self.mb_on(ctx, layer) { ctx.at(t) } else { *ctx };
+        let (l2c, _) = lctx.layer_to_comp(layer);
+        self.place_matrix(outer.map_or(l2c, |o| o * l2c), buf)
+    }
+
+    /// Shape and text content that animates within the shutter (paths, Trim Paths, text
+    /// animators…) of a motion-blurred layer: the times its source is drawn at and averaged,
+    /// Samples Per Frame of them, as After Effects does for shape layers. `None` when the content
+    /// holds still (compared through its cache key, which leaves the transform out).
+    pub(crate) fn content_times(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Vec<Tick>> {
+        if !matches!(layer.source, LayerSource::Shape | LayerSource::Text) || !self.mb_on(ctx, layer) {
+            return None;
+        }
+        let sh = self.shutter(ctx);
+        if sh.angle <= 0.0 {
+            return None;
+        }
+        let n = if self.opts.draft { 4 } else { (sh.samples as usize).clamp(2, 64) };
+        let times: Vec<Tick> = (0..n).map(|i| self.outer_at(ctx, sh.offset(i, n)).1).collect();
+        let key = |t: Tick| cache::layer_key(&ctx.at(t), layer, 1.0, false, false);
+        let k0 = key(*times.first()?)?;
+        let moves = [times.get(n / 2), times.last()].into_iter().flatten().any(|t| key(*t) != Some(k0));
+        moves.then_some(times)
+    }
+
+    /// The layer's source drawn at each of `times` and averaged (premultiplied) on the union of
+    /// their bounds. Content that also changes its raster scale within the shutter, or would need
+    /// an outsized buffer, is drawn once.
+    pub(crate) fn blurred_source(&self, ctx: &EvalCtx, layer: &Layer, times: &[Tick]) -> Option<Buf> {
+        let bufs: Vec<Buf> = times.iter().filter_map(|t| self.source(&ctx.at(*t), layer)).collect();
+        let scale = bufs.first()?.scale;
+        // Pixel = layer point × scale + offset: with the largest offset every buffer lands at
+        // x + (off - its offset) ≥ 0.
+        let off = [0, 1].map(|i| bufs.iter().map(|b| b.offset[i]).fold(f64::MIN, f64::max));
+        let w = bufs.iter().map(|b| off[0] - b.offset[0] + b.img.width as f64).fold(0.0, f64::max).ceil();
+        let h = bufs.iter().map(|b| off[1] - b.offset[1] + b.img.height as f64).fold(0.0, f64::max).ceil();
+        if bufs.iter().any(|b| (b.scale - scale).abs() > 1e-9) || !(w * h).is_finite() || w * h > (1u64 << 26) as f64 {
+            return self.source(ctx, layer);
+        }
+        let mut acc = Image::new(w as u32, h as u32);
+        let k = 1.0 / bufs.len() as f32;
+        for b in &bufs {
+            let m = Mat3::translate(vec2(off[0] - b.offset[0], off[1] - b.offset[1]));
+            effectcraft_raster::accumulate_warp(&mut acc, &b.img, &m, effectcraft_raster::Sampling::Bilinear, k);
+        }
+        Some(Buf { img: acc, offset: off, scale })
+    }
+
+    /// A processed-layer cache key that also covers content motion blur (the averaged source
+    /// depends on the content at every sub-sample).
+    pub(crate) fn content_key(&self, ctx: &EvalCtx, layer: &Layer, key: Option<u64>) -> Option<u64> {
+        let k = key?;
+        let Some(times) = self.content_times(ctx, layer) else { return Some(k) };
+        times.iter().try_fold(cache::derive(k, 0x6d62_6c72), |d, t| Some(cache::derive(d, cache::layer_key(&ctx.at(*t), layer, 1.0, false, false)?)))
+    }
+
+    /// Whether a layer is motion blurred: the render options, the comp's switch and the layer's
+    /// switch (limited by the precomp layers above when switches affect nested comps). Layer
+    /// motion, mask motion blur, effects that read the shutter and Advanced 3D all ask this.
+    pub(crate) fn mb_on(&self, ctx: &EvalCtx, layer: &Layer) -> bool {
+        self.opts.motion_blur && ctx.comp.enable_motion_blur && self.layer_motion_blur(layer)
+    }
+
+    /// What a layer's mask motion blur may do in this render (see [`masks::MaskBlur`]).
+    pub(crate) fn mask_blur(&self, ctx: &EvalCtx, layer: &Layer) -> masks::MaskBlur {
+        masks::MaskBlur {
+            allowed: self.opts.motion_blur && ctx.comp.enable_motion_blur && self.inherited.is_none_or(|(_, mb)| mb),
+            layer: self.layer_motion_blur(layer),
+            samples: if self.opts.draft { 4 } else { ctx.comp.motion_blur_samples as usize },
+        }
+    }
+
+    /// Motion-blur sub-samples for a layer buffer (1 = no motion blur). As in After Effects, a 2D
+    /// layer gets about one sample per output pixel its corners travel during the shutter,
+    /// at least Samples Per Frame and at most the comp's Adaptive Sample Limit; a layer that
+    /// does not move within the shutter is drawn once.
+    fn mb_samples(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf) -> usize {
+        if !self.blurred(ctx, layer) {
+            return 1;
+        }
+        let travel = self.shutter_travel(ctx, layer, buf);
+        if travel < 1e-3 {
+            return 1;
+        }
+        if self.opts.draft {
+            return 4;
+        }
+        let sh = self.shutter(ctx);
+        adaptive_samples(travel, sh.samples, sh.limit)
+    }
+
+    /// Largest distance (output pixels) a corner of the layer buffer moves during the shutter,
+    /// measured along the path at a few points.
+    fn shutter_travel(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf) -> f64 {
+        let sh = self.shutter(ctx);
+        let (w, h) = (buf.img.width as f64, buf.img.height as f64);
+        let corners = [(0.0, 0.0), (w, 0.0), (0.0, h), (w, h), (w * 0.5, h * 0.5)];
+        const PROBES: usize = 8;
+        let mut prev: Option<Vec<effectcraft_geom::Vec2>> = None;
+        let mut travel = vec![0.0f64; corners.len()];
+        for i in 0..PROBES {
+            let m = self.buf_matrix_at(ctx, layer, buf, sh.offset(i, PROBES));
+            let pts: Vec<_> = corners.iter().map(|&(x, y)| m.apply(vec2(x, y))).collect();
+            if let Some(p) = &prev {
+                for (k, (a, b)) in p.iter().zip(&pts).enumerate() {
+                    travel[k] += (b.x - a.x).hypot(b.y - a.y);
+                }
+            }
+            prev = Some(pts);
+        }
+        travel.into_iter().fold(0.0, f64::max)
+    }
+
+    /// Canvas pixels that compositing `buf` for `layer` can change: the transformed buffer's
+    /// bounds plus the resampling footprint. Stencil/silhouette modes, motion blur and
+    /// perspective fall back to the whole canvas.
+    ///
+    /// A quantised buffer placed pixel-exactly (integer translation, Normal, 100%) over a blank
+    /// canvas leaves exactly its own (quantised) pixels: nothing to re-quantise.
+    fn footprint(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf, opacity: f32, blank: bool) -> Region {
+        if layer.blend_mode.is_stencil() || self.mb_samples(ctx, layer, buf) > 1 {
+            return Region::Full;
+        }
+        let m = self.buf_matrix(ctx, layer, buf);
+        if !m.is_affine() {
+            return Region::Full;
+        }
+        let matte = layer.track_matte.is_some_and(|tm| tm.layer != layer.id && ctx.comp.layer(tm.layer).is_some());
+        let k = &m.0;
+        let integral = |v: f64| v == v.round();
+        if blank
+            && layer.blend_mode == BlendMode::Normal
+            && opacity == 1.0
+            && !matte
+            && !layer.preserve_transparency
+            && self.pipe.to_blend().is_none()
+            && k[0][0] == 1.0
+            && k[1][1] == 1.0
+            && k[0][1] == 0.0
+            && k[1][0] == 0.0
+            && integral(k[0][2])
+            && integral(k[1][2])
+        {
+            return Region::Empty;
+        }
+        let (w, h) = (buf.img.width as f64, buf.img.height as f64);
+        let c = [(0.0, 0.0), (w, 0.0), (0.0, h), (w, h)].map(|(x, y)| m.apply(vec2(x, y)));
+        let (x0, x1) = (c.iter().map(|p| p.x).fold(f64::INFINITY, f64::min), c.iter().map(|p| p.x).fold(f64::NEG_INFINITY, f64::max));
+        let (y0, y1) = (c.iter().map(|p| p.y).fold(f64::INFINITY, f64::min), c.iter().map(|p| p.y).fold(f64::NEG_INFINITY, f64::max));
+        color::PxRect::covering(x0, y0, x1, y1, 3.0).map_or(Region::Full, Region::Rect)
+    }
+
+    /// How a processed layer buffer lands in the output: one buffer → output matrix, or one per
+    /// motion-blur sub-sample (averaged), with the layer's sampling filter and dissolve seed.
+    pub fn placement(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf) -> Placement {
+        let samples = self.mb_samples(ctx, layer, buf);
+        let (sampling, seed) = (self.sampling(layer), layer.id.0 as u32);
+        if samples <= 1 {
+            return Placement { matrices: vec![self.buf_matrix(ctx, layer, buf)], sampling, seed };
+        }
+        let sh = self.shutter(ctx);
+        let matrices = (0..samples).map(|i| self.buf_matrix_at(ctx, layer, buf, sh.offset(i, samples))).collect();
+        Placement { matrices, sampling, seed }
+    }
+
+    /// Draw a processed layer into `target` (transform, motion blur) with `mode`/`opacity`.
+    pub(crate) fn place(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf, target: &mut Image, mode: BlendMode, opacity: f32) {
+        self.place_changed(ctx, layer, buf, target, PlacementBlend { mode, opacity, quantize: None });
+    }
+
+    /// [`Self::place`], returning the target pixels it changed when the warp tracked them (then
+    /// also quantised to `quantize` levels; see [`composite_warp_changed`]).
+    fn place_changed(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf, target: &mut Image, blend: PlacementBlend) -> Option<[u32; 4]> {
+        let PlacementBlend { mode, opacity, quantize } = blend;
+        let pl = self.placement(ctx, layer, buf);
+        let opts = WarpOpts { sampling: pl.sampling, opacity, mode, seed: pl.seed, clip: None };
+        if let [m] = pl.matrices.as_slice() {
+            return composite_warp_changed(target, &buf.img, m, &opts, quantize);
+        }
+        // Sub-samples sum straight into one buffer (each warp is row-parallel).
+        let mut acc = Image::new(target.width, target.height);
+        let k = 1.0 / pl.matrices.len() as f32;
+        for m in &pl.matrices {
+            effectcraft_raster::accumulate_warp(&mut acc, &buf.img, m, opts.sampling, k);
+        }
+        target.blend_from(&acc, mode, opacity, pl.seed);
+        None
+    }
+
+    /// Draw a 2D layer into `canvas`; returns the region it may have changed.
+    pub(crate) fn draw_layer(&self, ctx: &EvalCtx, layer: &Layer, canvas: &mut Image, blank: bool) -> Region {
+        let opacity = ctx.opacity(layer) as f32 * self.opacity_mul;
+        if self.quality(layer) == Quality::Wireframe && !layer.switches.adjustment {
+            self.draw_wireframe(ctx, layer, canvas);
+            return Region::Full;
+        }
+        if opacity <= 0.0 && !layer.switches.adjustment {
+            return Region::Empty;
+        }
+        if layer.switches.adjustment {
+            self.draw_adjustment(ctx, layer, canvas, opacity);
+            return Region::Full;
+        }
+        let mut timing = self.profile.map(|_| LayerTiming { depth: self.depth, layer: layer.name.clone(), ..Default::default() });
+        let t0 = web_time::Instant::now();
+        let Some(st) = self.styled(ctx, layer, timing.as_mut()) else { return Region::Empty };
+        let st = self.styled_to_blend(st);
+        let t1 = web_time::Instant::now();
+        let changed = if st.plain {
+            // Pixels the warp tracks are quantised as it blends them (nothing left to do); the
+            // footprint is still needed when it doesn't, or when no pixel needs quantising.
+            let footprint = self.footprint(ctx, layer, &st.body, opacity, blank);
+            let quantize = if footprint == Region::Empty { None } else { self.pipe.levels };
+            match self.composite_layer(ctx, layer, &st.body, canvas, opacity, quantize) {
+                Some(_) if quantize.is_some() => Region::Empty,
+                drawn => narrow(footprint, drawn),
+            }
+        } else {
+            self.composite_styled(ctx, layer, &st, canvas, opacity);
+            Region::Full
+        };
+        if let (Some(prof), Some(mut timing)) = (self.profile, timing) {
+            timing.process_ms = (t1 - t0).as_secs_f64() * 1e3;
+            timing.composite_ms = t1.elapsed().as_secs_f64() * 1e3;
+            if let Ok(mut v) = prof.lock() {
+                v.push(timing);
+            }
+        }
+        changed
+    }
+
+    /// Composite a styled layer: exterior passes with their own modes, then the body with the
+    /// layer's mode; the layer's opacity fades the whole stack. Knockout clears what is below the
+    /// layer's content; switched-off R/G/B channels keep the values below.
+    fn composite_styled(&self, ctx: &EvalCtx, layer: &Layer, st: &StyledLayer, canvas: &mut Image, opacity: f32) {
+        let bl = styles::blending(ctx, layer);
+        let matte = layer.track_matte.is_some_and(|tm| tm.layer != layer.id && ctx.comp.layer(tm.layer).is_some());
+        if matte || layer.preserve_transparency {
+            let mut iso = Image::new(canvas.width, canvas.height);
+            for (b, m) in &st.passes {
+                self.place(ctx, layer, b, &mut iso, *m, 1.0);
+            }
+            self.place(ctx, layer, &st.body, &mut iso, BlendMode::Normal, 1.0);
+            self.composite_iso(ctx, layer, iso, canvas, opacity);
+            return;
+        }
+        let mut tmp = canvas.clone();
+        if bl.knockout > 0 {
+            let mut k = Image::new(canvas.width, canvas.height);
+            self.place(ctx, layer, &st.content, &mut k, BlendMode::Normal, 1.0);
+            tmp.data.par_iter_mut().zip(k.data.par_iter()).for_each(|(p, q)| {
+                let keep = 1.0 - q[3].clamp(0.0, 1.0);
+                for c in p.iter_mut() {
+                    *c *= keep;
+                }
+            });
+        }
+        for (b, m) in &st.passes {
+            self.place(ctx, layer, b, &mut tmp, *m, 1.0);
+        }
+        self.place(ctx, layer, &st.body, &mut tmp, layer.blend_mode, 1.0);
+        let ch = bl.channels;
+        canvas.data.par_iter_mut().zip(tmp.data.par_iter()).for_each(|(c, t)| {
+            for i in 0..4 {
+                let v = if i < 3 && !ch[i] { c[i] } else { t[i] };
+                c[i] += (v - c[i]) * opacity;
+            }
+        });
+    }
+
+    /// Composite a plain layer; returns the canvas pixels it changed when they are known (then
+    /// also quantised to `quantize` levels).
+    fn composite_layer(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf, canvas: &mut Image, opacity: f32, quantize: Option<f32>) -> Option<[u32; 4]> {
+        let matte = layer.track_matte.is_some_and(|tm| tm.layer != layer.id && ctx.comp.layer(tm.layer).is_some());
+        if !matte && !layer.preserve_transparency {
+            return self.place_changed(ctx, layer, buf, canvas, PlacementBlend { mode: layer.blend_mode, opacity, quantize });
+        }
+        // Render in isolation, then matte / preserve transparency, then blend.
+        let mut iso = Image::new(canvas.width, canvas.height);
+        self.place(ctx, layer, buf, &mut iso, BlendMode::Normal, 1.0);
+        self.composite_iso(ctx, layer, iso, canvas, opacity);
+        None
+    }
+
+    /// Apply the track matte / preserve transparency to an isolated layer render, then blend.
+    pub(crate) fn composite_iso(&self, ctx: &EvalCtx, layer: &Layer, iso: Image, canvas: &mut Image, opacity: f32) {
+        self.composite_iso_with(ctx, layer, iso, canvas, opacity, None);
+    }
+
+    /// [`Self::composite_iso`] with the track matte's pixels already drawn (`matte`, e.g. a 3D
+    /// matte seen through the camera); otherwise the matte layer is placed in 2D.
+    pub(crate) fn composite_iso_with(&self, ctx: &EvalCtx, layer: &Layer, mut iso: Image, canvas: &mut Image, opacity: f32, matte_img: Option<Image>) {
+        self.apply_track_matte(ctx, layer, &mut iso, matte_img);
+        if layer.preserve_transparency {
+            iso.data.par_iter_mut().zip(canvas.data.par_iter()).for_each(|(p, q)| {
+                for c in p.iter_mut() {
+                    *c *= q[3];
+                }
+            });
+        }
+        canvas.blend_from(&iso, layer.blend_mode, opacity, layer.id.0 as u32);
+    }
+
+    /// Multiply `img` (comp-sized) by the layer's track matte, if it has one; `matte_img` as in
+    /// [`Self::composite_iso_with`].
+    fn apply_track_matte(&self, ctx: &EvalCtx, layer: &Layer, img: &mut Image, matte_img: Option<Image>) {
+        let matte = layer.track_matte.and_then(|tm| ctx.comp.layer(tm.layer).filter(|m| m.id != layer.id).map(|m| (m, tm.kind)));
+        if let Some((m, kind)) = matte {
+            let mimg = match matte_img {
+                Some(i) if i.width == img.width && i.height == img.height => i,
+                _ => {
+                    let mut mimg = Image::new(img.width, img.height);
+                    if m.is_active_at(ctx.time)
+                        && let Some(mb) = self.layer_buf(ctx, m)
+                    {
+                        let mo = ctx.opacity(m) as f32;
+                        self.place(ctx, m, &mb, &mut mimg, BlendMode::Normal, mo);
+                    }
+                    mimg
+                }
+            };
+            img.data.par_iter_mut().zip(mimg.data.par_iter()).for_each(|(p, q)| {
+                let k = match kind {
+                    MatteKind::Alpha => q[3],
+                    MatteKind::AlphaInverted => 1.0 - q[3],
+                    MatteKind::Luma => effectcraft_color::luminance(q[0], q[1], q[2]),
+                    MatteKind::LumaInverted => 1.0 - effectcraft_color::luminance(q[0], q[1], q[2]),
+                }
+                .clamp(0.0, 1.0);
+                for c in p.iter_mut() {
+                    *c *= k;
+                }
+            });
+        }
+    }
+
+    /// Adjustment layer: effects applied to the comp below, limited to the layer's footprint
+    /// and its track matte.
+    fn draw_adjustment(&self, ctx: &EvalCtx, layer: &Layer, canvas: &mut Image, opacity: f32) {
+        let Some(mut foot) = self.source(ctx, layer) else { return };
+        let _ = masks::apply(ctx, layer, &mut foot, self.mask_blur(ctx, layer));
+        let mut matte = Image::new(canvas.width, canvas.height);
+        self.place(ctx, layer, &foot, &mut matte, BlendMode::Normal, 1.0);
+        self.apply_track_matte(ctx, layer, &mut matte, None);
+        let o = self.roi_offset().map(|(x, y, _, _)| [-x, -y]).unwrap_or([0.0; 2]);
+        let mut below = Buf { img: canvas.clone(), offset: o, scale: self.opts.scale };
+        // Effects run in the working space, not the linear blending space.
+        if let Some(c) = self.pipe.from_blend() {
+            color::convert(&mut below.img, &c);
+        }
+        let mut adjusted = self.apply_effects(ctx, layer, below, true);
+        // An effect that changed the frame (Motion Tile's Output size): back onto the canvas.
+        if let Some((dx, dy)) =
+            effectcraft_effects::adjustment_crop(adjusted.offset, o, (adjusted.img.width, adjusted.img.height), (canvas.width, canvas.height))
+        {
+            adjusted.img = adjusted.img.crop(dx, dy, canvas.width, canvas.height);
+        }
+        if let Some(c) = self.pipe.to_blend() {
+            color::convert(&mut adjusted.img, &c);
+        }
+        if adjusted.img.width != canvas.width || adjusted.img.height != canvas.height {
+            return;
+        }
+        canvas.data.par_iter_mut().zip(adjusted.img.data.par_iter()).zip(matte.data.par_iter()).for_each(|((c, a), m)| {
+            let k = m[3] * opacity;
+            for i in 0..4 {
+                c[i] += (a[i] - c[i]) * k;
+            }
+        });
+    }
+}
+
+/// A layer ready to composite (see [`Renderer::styled_layer`]).
+pub struct StyledLayer {
+    /// Exterior style passes (Drop Shadow, Outer Glow) with their blend modes.
+    pub passes: Vec<(Arc<Buf>, BlendMode)>,
+    pub body: Arc<Buf>,
+    /// Pre-style pixels (knockout shape).
+    pub content: Arc<Buf>,
+    /// Styled cache key (the content key when plain).
+    pub(crate) key: Option<u64>,
+    /// Content cache key.
+    ckey: Option<u64>,
+    /// No layer styles: composite `body` the usual way.
+    pub plain: bool,
+}
+
+/// Where a layer buffer lands (see [`Renderer::placement`]).
+#[derive(Clone, Debug)]
+pub struct Placement {
+    /// Buffer pixel → output pixel; several = motion-blur sub-samples (equal weights).
+    pub matrices: Vec<Mat3>,
+    pub sampling: effectcraft_raster::Sampling,
+    /// Dissolve noise seed.
+    pub seed: u32,
+}
+
+/// The part of `footprint` a warp actually changed (`drawn`, see [`composite_warp_changed`]):
+/// pixels it left alone are still quantised.
+fn narrow(footprint: Region, drawn: Option<[u32; 4]>) -> Region {
+    let Some([x0, y0, x1, y1]) = drawn else { return footprint };
+    if x0 >= x1 || y0 >= y1 {
+        return Region::Empty;
+    }
+    let r = color::PxRect { x0, y0, x1, y1 };
+    match footprint {
+        Region::Empty => Region::Empty,
+        Region::Full => Region::Rect(r),
+        Region::Rect(f) => {
+            let q = color::PxRect { x0: r.x0.max(f.x0), y0: r.y0.max(f.y0), x1: r.x1.min(f.x1), y1: r.y1.min(f.y1) };
+            if q.x0 >= q.x1 || q.y0 >= q.y1 { Region::Empty } else { Region::Rect(q) }
+        }
+    }
+}
diff --git a/crates/render/src/lib.rs b/crates/render/src/lib.rs
index e4fc8e6e5..0552a44d4 100644
--- a/crates/render/src/lib.rs
+++ b/crates/render/src/lib.rs
@@ -32,539 +32,34 @@ use effectcraft_effects::{Buf, EffectCtx, EffectEnv, EffectHost, LayerPixels, Pa
 use effectcraft_geom::{Mat3, Mat4, vec2};
 use effectcraft_project::{Comp, Footage, FootageKind, FrameBlend, GroupKind, ItemId, ItemKind, Layer, LayerSource, MatteKind, Project, Quality, Sampling};
 pub use effectcraft_raster::Image;
-use effectcraft_raster::{WarpOpts, composite_warp};
+use effectcraft_raster::{WarpOpts, composite_warp_changed};
 use effectcraft_time::{FrameRate, TICKS_PER_SECOND, Tick};
 pub use eval::{EvalCtx, ExprHost, effect_bounds, source_size};
 use rayon::prelude::*;
 
-/// How a [`FootageSource`] hands over float footage (OpenEXR, float TIFF), whose values are
-/// linear light: encoded with a curve, as the compositor takes footage, or as stored. Other
-/// footage is decoded the same way whatever it says. Interpret Footage ▸ Preserve RGB always
-/// reads the values as stored.
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash)]
-pub enum FloatCurve {
-    /// The sRGB curve (managed projects, and Working Gamma 2.2).
-    #[default]
-    Srgb,
-    /// A pure 2.4 power curve (no working space, Working Gamma 2.4).
-    Gamma24,
-    /// The linear values as stored (Interpret As Linear Light encodes them afterwards).
-    Linear,
-}
+mod accel;
+mod footage;
+mod frames;
+mod fx_host;
+mod layers;
+mod opts;
+mod pipeline;
 
-/// Supplies decoded footage frames (implemented by the media layer).
-pub trait FootageSource: Send + Sync {
-    /// The frame of `item` at source time `t`, straight from the file (any size).
-    fn frame(&self, item: ItemId, footage: &Footage, t: Tick) -> Option<Arc<Image>>;
-    /// [`FootageSource::frame`] for a render that shows it at `width` × `height`, at most half its
-    /// size: either that frame or, when the source can make it more cheaply than the whole frame
-    /// (movies, see `effectcraft-media`), the frame already resampled to that size as
-    /// [`effectcraft_raster::resample`] would.
-    fn frame_at_size(&self, item: ItemId, footage: &Footage, t: Tick, _width: u32, _height: u32) -> Option<Arc<Image>> {
-        self.frame(item, footage, t)
-    }
-    /// [`FootageSource::frame`] (`size: None`) or [`FootageSource::frame_at_size`] with float
-    /// footage handed over as `float` says ([`FootageSource::frame`] uses [`FloatCurve::Srgb`]).
-    /// Sources without float footage can leave the default, which ignores `float`.
-    fn frame_with(&self, item: ItemId, footage: &Footage, t: Tick, size: Option<(u32, u32)>, float: FloatCurve) -> Option<Arc<Image>> {
-        let _ = float;
-        match size {
-            Some((w, h)) => self.frame_at_size(item, footage, t, w, h),
-            None => self.frame(item, footage, t),
-        }
-    }
-    /// `frames` interleaved stereo sample frames of `item`'s audio from source time `t` at
-    /// `rate` Hz (`None` when unavailable). The first sample is `t.to_units_floor(rate)`;
-    /// a sample boundary uses the earliest representable tick that selects that sample.
-    fn audio(&self, _item: ItemId, _footage: &Footage, _t: Tick, _frames: usize, _rate: u32) -> Option<Vec<f32>> {
-        None
-    }
-    /// Auxiliary 3D channels of `item` at source time `t` (multi-layer OpenEXR: depth, IDs,
-    /// Cryptomatte, any named channel), with `scale` relative to the file's pixels. `None` when
-    /// the footage has none.
-    fn aux(&self, _item: ItemId, _footage: &Footage, _t: Tick) -> Option<Arc<effectcraft_raster::AuxChannels>> {
-        None
-    }
-    /// The parsed 3D model of a [`effectcraft_project::FootageKind::Model`] item (Advanced 3D).
-    fn model(&self, _item: ItemId, _footage: &Footage) -> Option<Arc<effectcraft_model::Model>> {
-        None
-    }
-    /// Set the decoded-frame cache budget in bytes (Settings ▸ Memory & CPU); sources without
-    /// a cache ignore it.
-    fn set_cache_budget(&self, _bytes: usize) {}
-    /// Drop the decoded frames it keeps (Edit ▸ Purge ▸ All Memory / Image Cache Memory): the
-    /// next reads decode again. Sources without a cache ignore it.
-    fn purge(&self) {}
-    /// The file at `path` changed on disk (Reload Footage): drop what it keeps of it (decoded
-    /// frames, open decoders, parsed models), so the next reads see the new contents. Sources
-    /// without a cache ignore it.
-    fn forget(&self, _path: &str) {}
-    /// Settings ▸ Disk ▸ Conformed Audio Folder: where decoded audio is kept between reads
-    /// (`None` = off); sources that don't decode audio ignore it.
-    fn set_conform_folder(&self, _folder: Option<std::path::PathBuf>) {}
-    /// The decoded-frame cache budget in bytes, if the source has a cache.
-    fn cache_budget(&self) -> Option<usize> {
-        None
-    }
-    /// Vector footage (SVG) rasterised at `scale` × its pixel size, for Continuously Rasterize.
-    /// `None` when the footage is not vector or cannot be read.
-    fn vector_frame(&self, _item: ItemId, _footage: &Footage, _scale: f64) -> Option<Arc<Image>> {
-        None
-    }
-    /// Run `f`, which reads frames from this source, as work that can be called off: once
-    /// `cancel` is set, long decodes it starts (a movie seeking back to a keyframe and decoding
-    /// forward) stop early and their frames come back `None`. Sources that can't stop a decode
-    /// just run `f`. See [`CancellableFootage`].
-    fn cancellable(&self, _cancel: &Arc<AtomicBool>, f: &mut dyn FnMut()) {
-        f()
-    }
-    /// Reads through this source have been called off: frames may have come back `None` that
-    /// exist, so what was made from them must not be kept.
-    fn called_off(&self) -> bool {
-        false
-    }
-    /// Why `footage` shows no picture although its file is there: a read of it failed because
-    /// no decoder handles its codec, profile, chroma format or bit depth, or the stream is damaged
-    /// (e.g. "H.264 (High 4:2:2) isn't supported by the built-in decoder: ..."). `None` while it
-    /// decodes, and for sources that don't track failures. Stays set until the file is forgotten.
-    fn problem(&self, _footage: &Footage) -> Option<String> {
-        None
-    }
-}
-
-/// A render's view of a [`FootageSource`] whose frame reads can be called off with `cancel`
-/// (a viewer frame nobody waits for any more, #329). Every read goes through
-/// [`FootageSource::cancellable`] on its own, so reads made for this render on another thread
-/// (a parallel loop) answer to this render's flag, and reads for other renders never do.
-pub struct CancellableFootage<'a> {
-    pub inner: &'a dyn FootageSource,
-    pub cancel: Arc<AtomicBool>,
-}
-
-impl CancellableFootage<'_> {
-    fn read<R>(&self, f: impl FnOnce() -> Option<R>) -> Option<R> {
-        if self.cancel.load(Ordering::Relaxed) {
-            return None;
-        }
-        let (mut f, mut out) = (Some(f), None);
-        self.inner.cancellable(&self.cancel, &mut || out = f.take().and_then(|f| f()));
-        out
-    }
-}
-
-impl FootageSource for CancellableFootage<'_> {
-    fn frame(&self, item: ItemId, footage: &Footage, t: Tick) -> Option<Arc<Image>> {
-        self.read(|| self.inner.frame(item, footage, t))
-    }
-    fn frame_at_size(&self, item: ItemId, footage: &Footage, t: Tick, width: u32, height: u32) -> Option<Arc<Image>> {
-        self.read(|| self.inner.frame_at_size(item, footage, t, width, height))
-    }
-    fn audio(&self, item: ItemId, footage: &Footage, t: Tick, frames: usize, rate: u32) -> Option<Vec<f32>> {
-        self.inner.audio(item, footage, t, frames, rate)
-    }
-    fn aux(&self, item: ItemId, footage: &Footage, t: Tick) -> Option<Arc<effectcraft_raster::AuxChannels>> {
-        self.inner.aux(item, footage, t)
-    }
-    fn model(&self, item: ItemId, footage: &Footage) -> Option<Arc<effectcraft_model::Model>> {
-        self.inner.model(item, footage)
-    }
-    fn set_cache_budget(&self, bytes: usize) {
-        self.inner.set_cache_budget(bytes)
-    }
-    fn purge(&self) {
-        self.inner.purge()
-    }
-    fn forget(&self, path: &str) {
-        self.inner.forget(path)
-    }
-    fn set_conform_folder(&self, folder: Option<std::path::PathBuf>) {
-        self.inner.set_conform_folder(folder)
-    }
-    fn cache_budget(&self) -> Option<usize> {
-        self.inner.cache_budget()
-    }
-    fn vector_frame(&self, item: ItemId, footage: &Footage, scale: f64) -> Option<Arc<Image>> {
-        self.inner.vector_frame(item, footage, scale)
-    }
-    fn cancellable(&self, cancel: &Arc<AtomicBool>, f: &mut dyn FnMut()) {
-        self.inner.cancellable(cancel, f)
-    }
-    fn called_off(&self) -> bool {
-        self.cancel.load(Ordering::Relaxed) || self.inner.called_off()
-    }
-    fn problem(&self, footage: &Footage) -> Option<String> {
-        self.inner.problem(footage)
-    }
-    fn frame_with(&self, item: ItemId, footage: &Footage, t: Tick, size: Option<(u32, u32)>, float: FloatCurve) -> Option<Arc<Image>> {
-        self.read(|| self.inner.frame_with(item, footage, t, size, float))
-    }
-}
-
-/// Footage that can be rasterised at any scale (SVG).
-pub fn is_vector_footage(f: &Footage) -> bool {
-    matches!(f.codec.as_str(), "SVG" | "PDF" | "AI" | "EPS")
-}
-
-/// Layer parameters and audio for effects (see [`effectcraft_effects::EffectHost`]). What it
-/// hands out is in effect space (see [`effect_bounds`]): the other layer's for its pixels, the
-/// running layer's for its own frames and the comp scene.
-struct FxHost<'r, 'a, 'c> {
-    r: &'r Renderer<'a>,
-    ctx: &'c EvalCtx<'a>,
-    layer: &'c Layer,
-    /// Where the stack's effect space starts in layer coordinates (zero on adjustment layers,
-    /// whose effects run on the comp below).
-    origin: [f64; 2],
-    /// Index of the effect being rendered (bounds `self_at` to effects before it).
-    index: usize,
-    original: Option<&'c Buf>,
-}
-
-impl FxHost<'_, '_, '_> {
-    /// Another layer's pixels for a layer parameter, in its effect space; `layer_space`: `buf`
-    /// is still in layer space (its source or its content).
-    fn pixels(&self, other: &Layer, mut buf: Buf, layer_space: bool) -> LayerPixels {
-        let (size, origin) = self.ctx.effect_bounds(other);
-        if layer_space {
-            buf.rebase(origin);
-        }
-        LayerPixels { buf, size }
-    }
-}
-
-/// The comp's camera and first light relative to `layer`, in its layer pixels (see
-/// [`EffectHost::comp_scene`]): the comp camera's view of the layer (as if 3D at its transform),
-/// brought back into the layer's own pixel grid through the inverse of how the layer itself
-/// composites.
-pub(crate) fn comp_scene(ctx: &EvalCtx, layer: &Layer) -> Option<effectcraft_effects::CompScene> {
-    let world = ctx.world_matrix(layer);
-    let (cam, _, _) = ctx.camera();
-    let p = (cam * world).0;
-    let back = ctx.layer_to_comp(layer).0.inverse()?.0;
-    let rows = [p[0], p[1], p[3]];
-    let camera: [[f64; 4]; 3] = std::array::from_fn(|i| std::array::from_fn(|j| (0..3).map(|k| back[i][k] * rows[k][j]).sum()));
-    let inv = world.inverse();
-    let light = three_d::light::lights_at(ctx).first().and_then(|l| {
-        let inv = inv.as_ref()?;
-        let pos = inv.apply(l.pos);
-        let dir = inv.apply_vec(l.dir);
-        let len = (dir.x * dir.x + dir.y * dir.y + dir.z * dir.z).sqrt().max(1e-12);
-        let kind = match l.kind {
-            effectcraft_project::LightKind::Parallel => 0,
-            effectcraft_project::LightKind::Ambient => 2,
-            _ => 1,
-        };
-        Some(effectcraft_effects::CompLight { pos: [pos.x, pos.y, pos.z], dir: [dir.x / len, dir.y / len, dir.z / len], color: l.color, kind })
-    });
-    let camera_layer = ctx.comp.active_camera(ctx.time).is_some();
-    Some(effectcraft_effects::CompScene { camera: Some(camera), camera_layer, light })
-}
-
-/// Nesting limit for effects that render layers (other layers, other times).
-const MAX_FX_DEPTH: usize = 8;
-
-impl EffectHost for FxHost<'_, '_, '_> {
-    fn original(&self) -> Option<&Buf> {
-        self.original
-    }
-
-    fn particles(&self) -> Option<&dyn effectcraft_effects::psim::ParticleSim> {
-        self.r.active_accel().and_then(|a| a.particles())
-    }
-    fn layer(&self, id: u64, masks_and_effects: bool) -> Option<LayerPixels> {
-        let other = self.ctx.layer(effectcraft_project::LayerId(id))?;
-        if (other.id == self.layer.id && masks_and_effects) || self.r.depth > MAX_FX_DEPTH {
-            return None;
-        }
-        let sub = self.r.nested();
-        // The cached layer buffer is shared; effects get their own copy.
-        let buf = if masks_and_effects { (*sub.content_buf(self.ctx, other)?).clone() } else { sub.source(self.ctx, other)? };
-        Some(self.pixels(other, buf, true))
-    }
-
-    fn layer_masks(&self, id: u64) -> Option<LayerPixels> {
-        let other = self.ctx.layer(effectcraft_project::LayerId(id))?;
-        if self.r.depth > MAX_FX_DEPTH {
-            return None;
-        }
-        let sub = self.r.nested();
-        let buf = (*sub.layer_input(self.ctx, other, 0)?).clone();
-        Some(self.pixels(other, buf, false))
-    }
-
-    fn audio(&self, id: u64, start: f64, frames: usize, rate: u32) -> Option<Vec<f32>> {
-        let other = self.ctx.layer(effectcraft_project::LayerId(id))?;
-        let LayerSource::Footage { item } = &other.source else { return None };
-        let ItemKind::Footage(f) = &self.r.project.item(*item)?.kind else { return None };
-        if !f.has_audio {
-            return None;
-        }
-        let st = other.layer_time(Tick::from_seconds_f64(start));
-        self.r.footage.audio(*item, f, st, frames, rate)
-    }
-
-    fn self_at(&self, layer_time: f64, effects: usize) -> Option<Buf> {
-        if self.r.depth > MAX_FX_DEPTH || self.layer.switches.adjustment {
-            return None;
-        }
-        let n = effects.min(self.index);
-        let t = self.layer.comp_time(Tick::from_seconds_f64(layer_time));
-        let sub = self.r.nested();
-        sub.layer_input(&self.ctx.at(t), self.layer, n).map(|b| (*b).clone())
-    }
-
-    fn aux(&self) -> Option<Arc<effectcraft_raster::AuxChannels>> {
-        self.r.layer_aux(self.ctx, self.layer)
-    }
-
-    fn params_at(&self, layer_time: f64) -> Option<Params> {
-        let g = self.layer.effects()?.groups().nth(self.index)?;
-        let ctx = self.ctx.at(self.layer.comp_time(Tick::from_seconds_f64(layer_time)));
-        Some(effectcraft_effects::flatten_params(g, &mut |pr| ctx.value(self.layer, pr)))
-    }
-
-    fn comp_scene(&self) -> Option<effectcraft_effects::CompScene> {
-        Some(comp_scene(self.ctx, self.layer)?.rebased(self.origin))
-    }
-
-    fn layer_at(&self, id: u64, comp_time: f64, masks_and_effects: bool) -> Option<LayerPixels> {
-        let other = self.ctx.layer(effectcraft_project::LayerId(id))?;
-        if (other.id == self.layer.id && masks_and_effects) || !comp_time.is_finite() || self.r.depth > MAX_FX_DEPTH {
-            return None;
-        }
-        let ctx = self.ctx.at(Tick::from_seconds_f64(comp_time));
-        let sub = self.r.nested();
-        Some(if masks_and_effects {
-            self.pixels(other, (*sub.content_buf(&ctx, other)?).clone(), true)
-        } else if other.id == self.layer.id {
-            self.pixels(other, sub.source(&ctx, other)?, true)
-        } else {
-            // Preserve other-layer reads: time effects historically see source + masks.
-            self.pixels(other, (*sub.layer_input(&ctx, other, 0)?).clone(), false)
-        })
-    }
-}
-
-/// The Essential Properties overrides of a precomp layer, evaluated at the context time.
-pub fn essential_overrides(ctx: &EvalCtx, layer: &Layer) -> Vec<effectcraft_project::essential::Override> {
-    use effectcraft_project::essential;
-    let over = essential::overridden(layer);
-    let Some(g) = essential::group(layer).filter(|_| !over.is_empty()) else { return vec![] };
-    let mut out = vec![];
-    g.walk("", &mut |_, p| {
-        if over.contains(&p.uid)
-            && let Some(control) = essential::control_of(&p.match_id)
-        {
-            out.push(essential::Override { control, value: ctx.value(layer, p) });
-        }
-    });
-    out
-}
-
-/// No footage available (renders footage layers as transparent).
-pub struct NoFootage;
-impl FootageSource for NoFootage {
-    fn frame(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<Image>> {
-        None
-    }
-}
-
-/// Which compositor renders a frame (Project Settings ▸ Video Rendering and Effects).
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
-#[serde(rename_all = "lowercase")]
-pub enum Backend {
-    /// The CPU reference compositor (Mercury Software Only).
-    #[default]
-    Cpu,
-    /// The GPU compositor whenever an [`Accelerator`] is attached, whatever the project says.
-    Gpu,
-    /// The GPU compositor when an [`Accelerator`] is attached and the project's renderer is
-    /// Mercury GPU Acceleration (the viewer's choice); the CPU otherwise.
-    Auto,
-}
-
-impl Backend {
-    pub fn parse(s: &str) -> Option<Backend> {
-        match s.to_ascii_lowercase().as_str() {
-            "cpu" | "software" | "mercury software only" => Some(Backend::Cpu),
-            "gpu" | "mercury gpu acceleration" => Some(Backend::Gpu),
-            "auto" => Some(Backend::Auto),
-            _ => None,
-        }
-    }
-}
-
-/// One effect of a GPU effect chain (see [`Accelerator::effects`]).
-pub struct FxStep<'x> {
-    pub spec: &'static effectcraft_effects::EffectSpec,
-    pub ctx: EffectCtx<'x>,
-}
-
-/// A GPU (or other hardware) backend for the compositor. The CPU [`Renderer`] stays the
-/// reference: an accelerator renders what it supports and returns `None` for the rest, which
-/// then runs on the CPU. Implemented by `effectcraft-gpu`.
-pub trait Accelerator: Send + Sync {
-    /// Adapter / backend name for status readouts ("Apple M2 (Metal)").
-    fn name(&self) -> String;
-    /// Render a top-level comp frame (what [`Renderer::comp_frame`] returns). `None` = not
-    /// handled (the CPU renders it).
-    fn comp_frame(&self, r: &Renderer, comp: ItemId, t: Tick) -> Option<Image>;
-    /// The accelerator implements effect `id` with the CPU effect's semantics.
-    fn supports_effect(&self, id: &str) -> bool;
-    /// Run a chain of supported effects on `buf`, clamping and quantising to `levels` after
-    /// every effect when set (8/16 bpc). `None` = not handled.
-    fn effects(&self, chain: &[FxStep], buf: &Buf, levels: Option<f32>) -> Option<Buf>;
-    /// Rasterise and shade an Advanced 3D scene at its raster size (depth buffer, PBR, image
-    /// based light, shadow maps), with the CPU rasteriser's semantics
-    /// ([`three_d::adv::raster::render`]). `None` = not handled (the CPU renders it).
-    fn raster_3d(&self, _scene: &three_d::adv::Scene) -> Option<three_d::adv::Target> {
-        None
-    }
-    /// Render a whole prepared Advanced 3D run (every motion-blur sub-sample rasterised and
-    /// resolved, averaged, depth of field, encoding) with [`three_d::adv::render_prepared`]'s
-    /// semantics. `None` = not handled (the CPU path runs, using [`Self::raster_3d`]).
-    fn render_3d(&self, _run: &three_d::adv::Prepared) -> Option<three_d::adv::Rendered> {
-        None
-    }
-    /// A particle simulation backend (GPU particles) for the stepped particle effects, with
-    /// the CPU simulation's semantics. `None` = they simulate on the CPU.
-    fn particles(&self) -> Option<&dyn effectcraft_effects::psim::ParticleSim> {
-        None
-    }
-    /// Timing history [`Backend::Auto`] uses to send each comp's top-level frames to the
-    /// faster compositor. `None` = Auto always tries the accelerator first.
-    fn auto_pick(&self) -> Option<&AutoPick> {
-        None
-    }
-    /// Whether the accelerator can still render frames. `false` once it has stopped for good
-    /// (its device was lost or retired): every frame it is asked for falls back to the CPU, so
-    /// callers that limit frames in flight for it can stop doing so.
-    fn available(&self) -> bool {
-        true
-    }
-    /// Deferred readbacks: where a GPU readback cannot be waited for (WebGPU in a browser
-    /// worker), a frame renders in *passes*. A readback the accelerator does not have yet is
-    /// started, the step returns a cheap placeholder and the pass is marked missed
-    /// ([`Self::pass_missed`]); the caller waits for the readbacks in flight (asynchronously)
-    /// and renders the frame again, and the steps whose results arrived are served from them.
-    /// The frame is done after a pass with no miss. `frame_begin` forgets the previous frame's
-    /// results, `pass_begin` clears the miss. Synchronous accelerators never miss.
-    fn frame_begin(&self) {}
-    fn pass_begin(&self) {}
-    fn pass_missed(&self) -> bool {
-        false
-    }
-    /// Raised from a pass's first miss to its end (results computed meanwhile may hold
-    /// placeholders): give it to [`LayerCache::set_gate`] so they are not cached.
-    fn miss_gate(&self) -> Option<Arc<std::sync::atomic::AtomicBool>> {
-        None
-    }
-    /// With deferred readbacks: a future that resolves once the readbacks in flight have
-    /// landed (the browser delivers them from its event loop; natively the device is polled
-    /// before it returns, so the future is ready). `None` = nothing to wait for. See
-    /// [`passes::in_passes`].
-    fn settle(&self) -> Option<std::pin::Pin<Box<dyn std::future::Future<Output = ()> + '_>>> {
-        None
-    }
-}
-
-/// Where an effect stack runs (see [`Renderer::run_effects_on`]): a CPU buffer, or an image
-/// resident on an accelerator.
-pub trait FxTarget {
-    /// Run a chain of accelerator-supported effects (quantising after each to the bit depth).
-    /// `false` = not handled: the effects then run one by one through [`FxTarget::cpu`].
-    fn gpu(&mut self, steps: &[FxStep]) -> bool;
-    /// Run one CPU effect: `f` maps the buffer.
-    fn cpu(&mut self, f: &mut dyn FnMut(Buf) -> Buf);
-    /// Grow the buffer to cover its whole layer rectangle (`size` layer pixels from its own
-    /// corner, the `layer_size` handed to effects), as [`effectcraft_effects::Buf::cover`].
-    /// Authored buffers (text, shapes) only span their painted content; this gives the stack
-    /// the room a sized source's buffer already has (#659).
-    fn cover(&mut self, size: [f64; 2]) {
-        self.cpu(&mut |mut buf| {
-            buf.cover(size);
-            buf
-        });
-    }
-}
-
-/// The CPU effect target (GPU chains go through [`Accelerator::effects`]: upload, readback).
-struct CpuFx<'a> {
-    accel: Option<&'a dyn Accelerator>,
-    levels: Option<f32>,
-    buf: Option<Buf>,
-}
-
-impl FxTarget for CpuFx<'_> {
-    fn gpu(&mut self, steps: &[FxStep]) -> bool {
-        let (Some(a), Some(b)) = (self.accel, &self.buf) else { return false };
-        match a.effects(steps, b, self.levels) {
-            Some(out) => {
-                self.buf = Some(out);
-                true
-            }
-            None => false,
-        }
-    }
-    fn cpu(&mut self, f: &mut dyn FnMut(Buf) -> Buf) {
-        if let Some(b) = self.buf.take() {
-            self.buf = Some(f(b));
-        }
-    }
-}
-
-#[derive(Clone, Copy, Debug, serde::Serialize, serde::Deserialize)]
-#[serde(default, rename_all = "camelCase")]
-pub struct RenderOpts {
-    /// Output scale relative to comp pixels (1 = Full, 0.5 = Half…).
-    pub scale: f64,
-    pub motion_blur: bool,
-    /// Render guide layers (viewer only). Only the top-level comp's own guide layers: nested
-    /// comps (precomps, collapsed precomps, comps read by effects) never draw theirs, as in
-    /// After Effects (see `Renderer::nested_opts`).
-    pub guides: bool,
-    /// Draft quality: fewer motion-blur samples, bilinear only.
-    pub draft: bool,
-    /// 3D view camera override (viewer Front/Top/Custom views); None = the comp's active camera.
-    pub view: Option<three_d::CameraState>,
-    /// CPU or GPU compositor (the GPU needs [`Renderer::accel`]).
-    pub backend: Backend,
-    /// Region of interest `[x, y, w, h]` in comp pixels (viewer only): the top-level frame covers
-    /// just this rectangle, and only its pixels are composited.
-    pub roi: Option<[f64; 4]>,
-    /// Which proxies stand in for footage and compositions (Render Settings ▸ Proxy Use).
-    pub proxy: effectcraft_project::render_queue::ProxyUse,
-    /// Switches Affect Nested Comps (Settings ▸ General): a precomp layer's Quality and Motion
-    /// Blur switches also limit the layers of the nested comp (Draft/Wireframe or motion blur off
-    /// propagate down; they never raise a nested layer's own setting).
-    pub nested_switches: bool,
-    /// Realtime Shadows in Draft (Settings ▸ 3D): draft renders (`draft`) still cast shadows.
-    pub draft_shadows: bool,
-}
-
-impl RenderOpts {
-    /// Whether 3D layers cast shadows in this render.
-    pub fn shadows(&self) -> bool {
-        !self.draft || self.draft_shadows
-    }
-}
-
-impl Default for RenderOpts {
-    fn default() -> Self {
-        RenderOpts {
-            scale: 1.0,
-            motion_blur: true,
-            guides: false,
-            draft: false,
-            view: None,
-            roi: None,
-            backend: Backend::Cpu,
-            nested_switches: true,
-            draft_shadows: true,
-            proxy: effectcraft_project::render_queue::ProxyUse::CurrentSettings,
-        }
-    }
-}
+pub use accel::{Accelerator, Backend, FxStep, FxTarget};
+pub use footage::{CancellableFootage, FloatCurve, FootageSource, NoFootage, is_vector_footage};
+pub use frames::{
+    adaptive_samples, blend_frames, content_bounds, extended_region, field_frame, frame_position, frame_size, interpret_pixels, kurbo_path, render_frame,
+    roi_inside,
+};
+#[cfg(test)]
+use fx_host::FxHost;
+use fx_host::MAX_FX_DEPTH;
+pub(crate) use fx_host::comp_scene;
+pub use fx_host::essential_overrides;
+pub use layers::{Placement, StyledLayer};
+pub(crate) use opts::Collapse3d;
+pub use opts::{LayerTiming, RenderOpts};
+use opts::{MAX_THROUGH, Through};
 
 pub struct Renderer<'a> {
     pub project: &'a Project,
@@ -603,1858 +98,5 @@ pub struct Renderer<'a> {
     through_lost: bool,
 }
 
-/// One collapsed precomp layer a nested comp is drawn through.
-#[derive(Clone, Copy)]
-struct Through<'a> {
-    comp_id: ItemId,
-    comp: &'a Comp,
-    /// The containing comp's time at this frame.
-    time: Tick,
-    layer: &'a Layer,
-    /// The precomp layer is motion blurred: its own motion blurs the nested layers.
-    blur: bool,
-}
-
-/// Collapsed precomps within collapsed precomps that motion blur follows (more than
-/// [`Renderer::collapsed`]'s nesting limit).
-const MAX_THROUGH: usize = 16;
-
-/// A motion-blur shutter: the comp's, or for a collapsed precomp's layers the outermost
-/// containing comp's (they are drawn into its frames).
-#[derive(Clone, Copy)]
-struct Shutter {
-    /// Shutter angle and phase as fractions of a frame.
-    angle: f64,
-    phase: f64,
-    /// Frame duration (seconds).
-    frame: f64,
-    /// Samples Per Frame and Adaptive Sample Limit.
-    samples: u32,
-    limit: u32,
-}
-
-impl Shutter {
-    /// Seconds from the frame time to sub-sample `i` of `n`, spread over the open shutter.
-    fn offset(&self, i: usize, n: usize) -> f64 {
-        let f = if n > 1 { i as f64 / (n - 1) as f64 } else { 0.0 };
-        (self.phase + self.angle * f) * self.frame
-    }
-}
-
-/// How a collapsed precomp's 3D layers are placed in the parent (see `Renderer::collapse_into`).
-#[derive(Clone, Copy)]
-pub(crate) struct Collapse3d<'a> {
-    /// Nested comp world → parent world (the precomp layer's world transform).
-    pub world: Mat4,
-    /// The parent's camera.
-    pub cam: three_d::CameraState,
-    /// The outermost comp's context (its lights light the nested layers).
-    pub parent: EvalCtx<'a>,
-}
-
-/// Time spent on one layer of one frame (milliseconds).
-#[derive(Clone, Debug, Default)]
-pub struct LayerTiming {
-    pub depth: usize,
-    pub layer: String,
-    /// Source + masks + effects (cache lookup only, on a hit).
-    pub process_ms: f64,
-    /// Per effect: (effect id, ms). Empty on a cache hit.
-    pub effects: Vec<(String, f64)>,
-    /// Transform + matte + blend.
-    pub composite_ms: f64,
-    /// The processed buffer came from the layer cache.
-    pub cached: bool,
-}
-
-impl<'a> Renderer<'a> {
-    pub fn new(project: &'a Project, footage: &'a dyn FootageSource, opts: RenderOpts) -> Renderer<'a> {
-        Renderer {
-            project,
-            footage,
-            expr: None,
-            opts,
-            cache: None,
-            profile: None,
-            accel: None,
-            depth: 0,
-            pipe: color::Pipe::of(&project.settings),
-            outer: None,
-            opacity_mul: 1.0,
-            collapse3d: None,
-            inherited: None,
-            defer_dof: false,
-            top: true,
-            through: [None; MAX_THROUGH],
-            through_lost: false,
-        }
-    }
-
-    /// The layer cache to keep this render's buffers in: none once its footage reads were
-    /// called off, as they may have come back empty ([`FootageSource::called_off`], #329).
-    fn cache_to_keep(&self) -> Option<&'a LayerCache> {
-        self.cache.filter(|_| !self.footage.called_off())
-    }
-
-    /// A layer's Quality switch, limited by the precomp layers above it when
-    /// [`RenderOpts::nested_switches`] is on.
-    pub fn quality(&self, layer: &Layer) -> Quality {
-        let rank = |q: Quality| match q {
-            Quality::Best => 0,
-            Quality::Draft => 1,
-            Quality::Wireframe => 2,
-        };
-        match self.inherited {
-            Some((q, _)) if rank(q) > rank(layer.switches.quality) => q,
-            _ => layer.switches.quality,
-        }
-    }
-
-    /// A layer's Motion Blur switch, limited by the precomp layers above it.
-    pub(crate) fn layer_motion_blur(&self, layer: &Layer) -> bool {
-        layer.switches.motion_blur && self.inherited.is_none_or(|(_, mb)| mb)
-    }
-
-    /// The renderer for the nested comp of precomp layer `layer`: its switches pass down when
-    /// [`RenderOpts::nested_switches`] is on.
-    fn nested_through(&self, layer: &Layer) -> Renderer<'a> {
-        let mut sub = self.nested();
-        if self.opts.nested_switches {
-            sub.inherited = Some((self.quality(layer), self.layer_motion_blur(layer)));
-        }
-        sub
-    }
-
-    /// The render options one level down (precomps, collapsed precomps, comps read by effects):
-    /// guide layers render only in their own comp, never when it is nested.
-    fn nested_opts(&self) -> RenderOpts {
-        RenderOpts { guides: false, ..self.opts }
-    }
-
-    /// A renderer for nested work (precomps, layers read by effects): one level deeper.
-    fn nested(&self) -> Renderer<'a> {
-        Renderer {
-            opts: self.nested_opts(),
-            depth: self.depth + 1,
-            outer: None,
-            opacity_mul: 1.0,
-            collapse3d: None,
-            defer_dof: false,
-            top: false,
-            through: [None; MAX_THROUGH],
-            through_lost: false,
-            ..*self
-        }
-    }
-
-    /// A precomp layer's nested comp for an accelerator to render resident (no CPU render and
-    /// upload of the nested frame): the renderer one level down, the comp, its time and the
-    /// buffer scale, exactly as [`Self::layer_source`]'s comp branch would render it. `None`
-    /// when that branch does more (composition proxy, Essential Properties overrides, frame
-    /// blending, recursion) or draws nothing (outside the nested comp's span): use the CPU path.
-    pub fn precomp_source(&self, ctx: &EvalCtx, layer: &Layer) -> Option<(Renderer<'a>, ItemId, Tick, f64)> {
-        let LayerSource::Comp { item } = layer.source else { return None };
-        if layer.switches.adjustment || self.project.comp_contains(item, ctx.comp_id) {
-            return None;
-        }
-        let nc = self.project.comp(item)?;
-        let lt = ctx.nested_time(layer);
-        if self.content_times(ctx, layer).is_some() {
-            return None;
-        }
-        if !nc.covers(lt) || self.proxy_for(item).is_some() || !essential_overrides(ctx, layer).is_empty() || frame_blend_mode(ctx, layer) != FrameBlend::Off {
-            return None;
-        }
-        let s = self.opts.scale;
-        let bs = if s < 1.0 && nc.preserve_resolution { 1.0 } else { s };
-        let base = self.nested_through(layer);
-        Some((Renderer { opts: RenderOpts { scale: bs, ..base.opts }, ..base }, item, lt, bs))
-    }
-
-    /// The nested comp of a precomp layer whose transformations collapse into this comp: the
-    /// Collapse Transformations switch is on and the layer has no masks, effects or layer
-    /// styles (those force a flattened render of the precomp, as in After Effects).
-    pub fn collapsed(&self, ctx: &EvalCtx, layer: &Layer) -> Option<ItemId> {
-        if !layer.switches.collapse || layer.switches.adjustment || self.depth > 12 {
-            return None;
-        }
-        let LayerSource::Comp { item } = &layer.source else { return None };
-        if self.project.comp_contains(*item, ctx.comp_id) || self.project.comp(*item).is_none() {
-            return None;
-        }
-        if layer.masks().is_some_and(|m| !m.children.is_empty()) {
-            return None;
-        }
-        if layer.switches.effects && layer.effects().is_some_and(|fx| fx.groups().any(|g| g.enabled)) {
-            return None;
-        }
-        if styles::active(ctx, layer) {
-            return None;
-        }
-        // Instance overrides (Essential Properties) need the nested comp rendered on its own.
-        if !effectcraft_project::essential::overridden(layer).is_empty() {
-            return None;
-        }
-        Some(*item)
-    }
-
-    /// A renderer and context that draw a collapsed precomp's layers straight into this comp:
-    /// their transforms are concatenated with the precomp layer's (one resample, no
-    /// rasterisation at the precomp's bounds), their opacity multiplied by `opacity`, and their
-    /// 3D layers use this comp's camera and lights.
-    pub fn collapse_into(&self, ctx: &EvalCtx<'a>, layer: &'a Layer, item: ItemId, opacity: f32) -> Option<(Renderer<'a>, EvalCtx<'a>)> {
-        let nc = self.project.comp(item)?;
-        let t = ctx.nested_time(layer);
-        if !nc.covers(t) {
-            return None;
-        }
-        let nctx = EvalCtx { comp_id: item, comp: nc, time: t, ..*ctx };
-        let (l2c, _) = ctx.layer_to_comp(layer);
-        let outer = Some(self.outer.map_or(l2c, |o| o * l2c));
-        let world = ctx.world_matrix(layer);
-        let c3 = Collapse3d {
-            world: self.collapse3d.map_or(world, |c| c.world * world),
-            cam: three_d::compose::camera_for(self, ctx),
-            parent: self.collapse3d.map_or(*ctx, |c| c.parent),
-        };
-        // Motion blur follows the precomp layer's own motion too.
-        let link = Through { comp_id: ctx.comp_id, comp: ctx.comp, time: ctx.time, layer, blur: self.mb_on(ctx, layer) };
-        let mut through = self.through;
-        let slot = through.iter_mut().find(|t| t.is_none());
-        let through_lost = self.through_lost || slot.is_none();
-        if let Some(slot) = slot {
-            *slot = Some(link);
-        }
-        Some((
-            Renderer { opts: self.nested_opts(), depth: self.depth + 1, outer, opacity_mul: opacity, collapse3d: Some(c3), through, through_lost, ..*self },
-            nctx,
-        ))
-    }
-
-    pub(crate) fn opacity_mul(&self) -> f32 {
-        self.opacity_mul
-    }
-
-    /// Draw a collapsed 2D precomp layer: nested layers blend straight into `canvas` with their
-    /// own modes (Normal precomp, no matte); otherwise they are drawn into an isolated buffer
-    /// that then takes the precomp layer's track matte, Preserve Transparency and blend mode.
-    /// Returns the region left to re-quantise (nested layers drawn straight into `canvas`
-    /// quantise their own footprints).
-    fn draw_collapsed(&self, ctx: &EvalCtx<'a>, layer: &Layer, item: ItemId, canvas: &mut Image, blank: bool) -> Region {
-        let opacity = ctx.opacity(layer) as f32 * self.opacity_mul;
-        if opacity <= 0.0 {
-            return Region::Empty;
-        }
-        let matte = layer.track_matte.is_some_and(|tm| tm.layer != layer.id && ctx.comp.layer(tm.layer).is_some());
-        if layer.blend_mode == BlendMode::Normal && !matte && !layer.preserve_transparency {
-            if let Some((sub, nctx)) = self.collapse_into(ctx, layer, item, opacity) {
-                sub.draw_comp(&nctx, canvas, blank);
-            }
-            return Region::Empty;
-        }
-        let Some((sub, nctx)) = self.collapse_into(ctx, layer, item, 1.0) else { return Region::Empty };
-        let mut iso = Image::new(canvas.width, canvas.height);
-        sub.draw_comp(&nctx, &mut iso, true);
-        self.composite_iso(ctx, layer, iso, canvas, opacity);
-        Region::Full
-    }
-
-    /// Whether `layer`'s processed buffer (source → masks → effects) is cached and the same as
-    /// one frame earlier: drawing it from the layer cache (an accelerator uploads it once) beats
-    /// re-running its effects every frame.
-    pub fn layer_is_static(&self, ctx: &EvalCtx, layer: &Layer) -> bool {
-        if self.cache.is_none() {
-            return false;
-        }
-        let (scale, draft, blur) = (self.raster_scale(ctx, layer), self.opts.draft, self.mb_on(ctx, layer));
-        let prev = ctx.time - ctx.comp.frame_rate.frame_duration();
-        let now = cache::layer_key(ctx, layer, scale, draft, blur);
-        now.is_some() && now == cache::layer_key(&ctx.at(prev), layer, scale, draft, blur)
-    }
-
-    /// Rasterisation scale of a layer's source: the output scale, or — for text and shape layers,
-    /// which are always continuously rasterised (#390, #751), and Continuously Rasterize vector
-    /// footage — the output scale times the layer's on-screen scale (quarter-octave steps, rounded
-    /// up, so vector content is drawn at its final size and stays sharp when scaled up).
-    pub fn raster_scale(&self, ctx: &EvalCtx, layer: &Layer) -> f64 {
-        let s = self.opts.scale;
-        let continuous = match layer.source {
-            LayerSource::Text | LayerSource::Shape => true,
-            LayerSource::Footage { item } => {
-                layer.switches.collapse && matches!(self.project.item(item).map(|i| &i.kind), Some(ItemKind::Footage(f)) if is_vector_footage(f))
-            }
-            _ => false,
-        };
-        if !continuous {
-            return s;
-        }
-        let (l2c, _) = ctx.layer_to_comp(layer);
-        let m = self.outer.map_or(l2c, |o| o * l2c);
-        let a = layer.transform().map(|tr| ctx.v3(layer, tr, "anchor", [0.0; 3])).unwrap_or([0.0; 3]);
-        let p0 = m.apply(vec2(a[0], a[1]));
-        let px = m.apply(vec2(a[0] + 1.0, a[1]));
-        let py = m.apply(vec2(a[0], a[1] + 1.0));
-        let k = ((px.x - p0.x).hypot(px.y - p0.y)).max((py.x - p0.x).hypot(py.y - p0.y));
-        if !k.is_finite() || k <= 1e-6 {
-            return s;
-        }
-        // The step is rounded up past rounding noise only: an unscaled layer whose position isn't
-        // a whole number maps the unit vectors to lengths a hair over 1, which must stay 1 (#390:
-        // rounded up to 2^¼, unscaled text was drawn larger and resampled, softer).
-        let mut k = 2f64.powf((k.log2() * 4.0 - 1e-6).ceil() / 4.0).clamp(1.0 / 16.0, 64.0);
-        // Keep the buffer within about 16 million pixels.
-        if let Some(b) = content_bounds(ctx, layer) {
-            let area = ((b[2] - b[0]) * (b[3] - b[1])).max(1.0) * s * s;
-            k = k.min((16.0e6 / area).sqrt().max(1.0));
-        }
-        s * k
-    }
-
-    /// Draw a Wireframe-quality layer: its bounds as a one-pixel outline.
-    fn draw_wireframe(&self, ctx: &EvalCtx, layer: &Layer, canvas: &mut Image) {
-        for (x, y) in self.wireframe_pixels(ctx, layer, (canvas.width, canvas.height)) {
-            canvas.set(x, y, [1.0, 1.0, 1.0, 1.0]);
-        }
-    }
-
-    fn ctx(&self, comp_id: ItemId, comp: &'a Comp, t: Tick) -> EvalCtx<'a> {
-        EvalCtx { project: self.project, comp_id, comp, time: t, expr: self.expr, footage: Some(self.footage) }
-    }
-
-    /// This renderer with another accelerator (or none): the passes of
-    /// [`passes::in_passes`] render with the accelerator, its CPU fallback without.
-    pub fn with_accel(&self, accel: Option<&'a dyn Accelerator>) -> Renderer<'a> {
-        Renderer { accel, ..*self }
-    }
-
-    /// The accelerator to use for this render, if any (see [`Backend`]).
-    pub fn active_accel(&self) -> Option<&'a dyn Accelerator> {
-        let a = self.accel?;
-        match self.opts.backend {
-            Backend::Cpu => None,
-            Backend::Gpu => Some(a),
-            Backend::Auto => self.project.settings.gpu_acceleration.then_some(a),
-        }
-    }
-
-    /// Render a composition at comp time `t` (transparent background, comp size × scale).
-    /// Top-level frames go to the GPU when [`Self::active_accel`] is set and handles them.
-    pub fn comp_frame(&self, comp_id: ItemId, t: Tick) -> Image {
-        // Classic 3D runs composite on the GPU too (M12.7), so Auto sends 3D comps there as well;
-        // Auto renders each comp on whichever compositor measured faster ([`AutoPick`]).
-        if self.depth == 0
-            && let Some(a) = self.active_accel()
-        {
-            let auto = self.frame_auto(a, comp_id, false);
-            if auto.is_none_or(|(p, key)| p.choose(key)) {
-                let t0 = web_time::Instant::now();
-                if let Some(img) = a.comp_frame(self, comp_id, t) {
-                    if let Some((p, key)) = auto {
-                        p.record(key, true, t0.elapsed().as_secs_f64() * 1e3);
-                    }
-                    return img;
-                }
-                if let Some((p, key)) = auto {
-                    p.declined(key);
-                }
-            }
-            let t0 = web_time::Instant::now();
-            let img = self.comp_frame_cpu(comp_id, t);
-            if let Some((p, key)) = auto {
-                p.record(key, false, t0.elapsed().as_secs_f64() * 1e3);
-            }
-            return img;
-        }
-        self.comp_frame_cpu(comp_id, t)
-    }
-
-    /// The Auto timing history and key for a top-level frame of `comp` (`None` unless the
-    /// backend is [`Backend::Auto`] and the accelerator keeps history).
-    pub fn frame_auto(&self, a: &'a dyn Accelerator, comp: ItemId, display: bool) -> Option<(&'a AutoPick, AutoKey)> {
-        if self.opts.backend != Backend::Auto || self.opts.roi.is_some() {
-            return None;
-        }
-        Some((a.auto_pick()?, AutoKey::new(comp, self.opts.scale, display)))
-    }
-
-    /// [`Self::comp_frame`] on the CPU compositor only.
-    pub fn comp_frame_cpu(&self, comp_id: ItemId, t: Tick) -> Image {
-        let Some(comp) = self.project.comp(comp_id) else { return Image::new(1, 1) };
-        let s = self.opts.scale;
-        let (w, h) = frame_size(comp.width, comp.height, s);
-        // Region of interest on a comp with 3D layers: render the frame and crop it. A region
-        // reaching past the comp frame (the Extended Viewer) renders Classic 3D natively — the
-        // planes project through the offset camera — and Advanced 3D as the frame, padded.
-        if self.depth == 0
-            && let Some(r) = self.opts.roi
-            && comp.has_3d()
-            && (roi_inside(r, comp.width, comp.height) || comp.renderer == effectcraft_project::Renderer::Advanced3D)
-        {
-            let full = Renderer { opts: RenderOpts { roi: None, ..self.opts }, ..*self }.comp_frame(comp_id, t);
-            let (x0, y0) = ((r[0] * s).round() as i64, (r[1] * s).round() as i64);
-            let (rw, rh) = (((r[2] * s).round() as u32).max(1), ((r[3] * s).round() as u32).max(1));
-            let mut out = Image::new(rw, rh);
-            for y in 0..rh as i64 {
-                let sy = y + y0;
-                if sy < 0 || sy >= full.height as i64 {
-                    continue;
-                }
-                for x in 0..rw as i64 {
-                    let sx = x + x0;
-                    if sx >= 0 && sx < full.width as i64 {
-                        out.data[(y * rw as i64 + x) as usize] = full.data[(sy * full.width as i64 + sx) as usize];
-                    }
-                }
-            }
-            return out;
-        }
-        let (w, h) = match self.roi_offset() {
-            Some((_, _, rw, rh)) => (rw, rh),
-            None => (w, h),
-        };
-        let mut canvas = Image::new(w, h);
-        if self.depth > 16 {
-            return canvas;
-        }
-        let ctx = self.ctx(comp_id, comp, t);
-        self.draw_comp(&ctx, &mut canvas, true);
-        // The canvas is already quantised after every layer; only re-encoding changes it.
-        if let Some(c) = self.pipe.from_blend() {
-            color::convert(&mut canvas, &c);
-            self.pipe.quantize(&mut canvas);
-        }
-        // The top-level comp leaves the working space for the (sRGB) display / output.
-        if self.depth == 0
-            && let Some(c) = self.pipe.output()
-        {
-            color::convert(&mut canvas, &c);
-            self.pipe.quantize(&mut canvas);
-        }
-        if self.depth == 0
-            && let Some((lin, mode, enc)) = self.pipe.output_hdr()
-        {
-            color::output_hdr(&mut canvas, lin, mode, enc);
-            self.pipe.quantize(&mut canvas);
-        }
-        canvas
-    }
-
-    /// Draw a comp's layers (bottom to top) into `canvas` (blending space).
-    /// `blank`: the canvas is fully transparent (lets the first layer skip re-quantising).
-    fn draw_comp(&self, ctx: &EvalCtx<'a>, canvas: &mut Image, mut blank: bool) {
-        // Bottom-to-top, with runs of consecutive 3D layers depth-sorted (farthest first).
-        let visible = self.visible_layers(ctx);
-        let mut i = 0;
-        while i < visible.len() {
-            if visible[i].is_3d() {
-                let mut j = i;
-                while j < visible.len() && visible[j].is_3d() {
-                    j += 1;
-                }
-                three_d::compose::draw_run(self, ctx, &visible[i..j], canvas);
-                i = j;
-                self.pipe.quantize(canvas);
-                blank = false;
-            } else {
-                let changed = match self.collapsed(ctx, visible[i]) {
-                    Some(item) => self.draw_collapsed(ctx, visible[i], item, canvas, blank),
-                    None => self.draw_layer(ctx, visible[i], canvas, blank),
-                };
-                i += 1;
-                // 8/16 bpc: the comp is an integer buffer after every layer (only the pixels the
-                // layer touched need re-quantising).
-                self.pipe.quantize_region(canvas, changed);
-                blank = false;
-            }
-        }
-    }
-
-    /// Evaluate an effect instance's parameters.
-    fn effect_params(&self, ctx: &EvalCtx, layer: &Layer, g: &effectcraft_project::PropGroup) -> Params {
-        // Nested groups (Paint strokes, Puppet meshes and pins) are flattened too.
-        effectcraft_effects::flatten_params(g, &mut |pr| ctx.value(layer, pr))
-    }
-
-    fn apply_effects(&self, ctx: &EvalCtx, layer: &Layer, buf: Buf, adjustment: bool) -> Buf {
-        self.apply_effects_timed(ctx, layer, buf, adjustment, usize::MAX, None)
-    }
-
-    /// Run the first `limit` effects of the layer's stack (by position; disabled ones count) on
-    /// `buf` (layer space, or the comp below for an adjustment layer).
-    fn apply_effects_timed(&self, ctx: &EvalCtx, layer: &Layer, mut buf: Buf, adjustment: bool, limit: usize, timing: Option<&mut Vec<(String, f64)>>) -> Buf {
-        // The comp below an adjustment layer is not in its layer space: it stays as it is.
-        let origin = if adjustment { [0.0; 2] } else { ctx.effect_bounds(layer).1 };
-        buf.rebase(origin);
-        let mut out = self.effect_space_stack(ctx, layer, buf, adjustment, limit, timing, origin);
-        out.rebase([-origin[0], -origin[1]]);
-        out
-    }
-
-    /// [`Renderer::apply_effects_timed`] on a buffer already in effect space (measured from
-    /// `origin`, in layer coordinates); the result stays in effect space.
-    #[allow(clippy::too_many_arguments)]
-    fn effect_space_stack(
-        &self,
-        ctx: &EvalCtx,
-        layer: &Layer,
-        buf: Buf,
-        adjustment: bool,
-        limit: usize,
-        timing: Option<&mut Vec<(String, f64)>>,
-        origin: [f64; 2],
-    ) -> Buf {
-        let mut t = CpuFx { accel: self.active_accel(), levels: self.pipe.levels, buf: Some(buf) };
-        self.run_effect_stack(ctx, layer, adjustment, limit, timing, origin, &mut t);
-        t.buf.unwrap_or_else(|| Buf { img: Image::new(1, 1), offset: [0.0; 2], scale: self.opts.scale })
-    }
-
-    /// Run the layer's video effect stack on `target` (in effect space, measured from `origin`
-    /// in layer coordinates): runs of GPU-capable effects go to [`FxTarget::gpu`] (when an
-    /// accelerator is active and supports them), the rest to [`FxTarget::cpu`] one by one
-    /// (quantised to the bit depth after each).
-    #[allow(clippy::too_many_arguments)]
-    fn run_effect_stack(
-        &self,
-        ctx: &EvalCtx,
-        layer: &Layer,
-        adjustment: bool,
-        limit: usize,
-        mut timing: Option<&mut Vec<(String, f64)>>,
-        origin: [f64; 2],
-        target: &mut dyn FxTarget,
-    ) {
-        if !layer.switches.effects {
-            return;
-        }
-        let Some(fx) = layer.effects() else { return };
-        let lt = layer.layer_time(ctx.time);
-        let layer_size = ctx.effect_bounds(layer).0;
-        // #659: an authored layer's buffer spans only its painted content while the stack works
-        // on the layer's whole region (`layer_size`): give the buffer the room a sized source
-        // already has, so tiling or displacement can place pixels outside the content instead
-        // of losing them at its edge. Only when something will actually run, and not for an
-        // adjustment layer, whose buffer is the comp below and already spans it.
-        if !adjustment
-            && fx.groups().any(|g| g.enabled && matches!(&g.kind, GroupKind::Effect { effect } if effectcraft_effects::find(effect).is_some_and(|s| !effectcraft_effects::audio_fx::is_audio_effect(s.id)))) {
-            target.cover(layer_size);
-        }
-        let mut mask_shapes = masks::shapes(ctx, layer);
-        if origin != [0.0; 2] {
-            for q in mask_shapes.iter_mut().flat_map(|m| m.points.iter_mut()) {
-                *q = [q[0] - origin[0], q[1] - origin[1]];
-            }
-        }
-        // Capture once, before preceding effects can expand or replace the input. An
-        // adjustment stack's original is the comp below, not its solid source.
-        let needs_original =
-            fx.groups().take(limit).any(|g| g.enabled && matches!(&g.kind, GroupKind::Effect { effect } if effect == "ec.channel.cccomposite"));
-        let mut original = None;
-        if needs_original {
-            target.cpu(&mut |buf| {
-                original = Some(buf.clone());
-                buf
-            });
-        }
-        let host = FxHost { r: self, ctx, layer, origin, index: 0, original: original.as_ref() };
-        let env = EffectEnv {
-            masks: &mask_shapes,
-            host: Some(&host),
-            comp_time: ctx.time.seconds(),
-            frame_rate: ctx.comp.frame_rate.as_f64(),
-            effect_index: 0,
-            working_space: self.pipe.space,
-            working_linear: self.pipe.linear,
-            float_depth: self.pipe.levels.is_none(),
-            shutter: self.mb_on(ctx, layer).then_some((ctx.comp.shutter_angle, ctx.comp.shutter_phase, ctx.comp.motion_blur_samples)),
-        };
-        // Video effects in stack order (index, group, spec); disabled and audio effects skipped.
-        let stack: Vec<(usize, &effectcraft_project::PropGroup, &'static effectcraft_effects::EffectSpec)> = fx
-            .groups()
-            .enumerate()
-            .take_while(|(i, _)| *i < limit)
-            .filter(|(_, g)| g.enabled)
-            .filter_map(|(i, g)| match &g.kind {
-                GroupKind::Effect { effect } => effectcraft_effects::find(effect).map(|s| (i, g, s)),
-                _ => None,
-            })
-            .filter(|(_, _, s)| !effectcraft_effects::audio_fx::is_audio_effect(s.id))
-            .collect();
-        let accel = self.active_accel();
-        let mut k = 0;
-        while k < stack.len() {
-            let (i, g, spec) = stack[k];
-            // A run of GPU effects goes to the accelerator in one go.
-            if let Some(a) = accel
-                && spec.gpu
-                && a.supports_effect(spec.id)
-            {
-                let run: Vec<_> = stack[k..].iter().take_while(|(_, _, s)| s.gpu && a.supports_effect(s.id)).collect();
-                let params: Vec<Params> = run.iter().map(|(_, g, _)| self.effect_params(ctx, layer, g)).collect();
-                let hosts: Vec<_> = run.iter().map(|(i, _, _)| FxHost { index: *i, ..host }).collect();
-                let steps: Vec<FxStep> = run
-                    .iter()
-                    .zip(&params)
-                    .zip(&hosts)
-                    .map(|(((i, g, s), params), host)| FxStep {
-                        spec: s,
-                        ctx: EffectCtx {
-                            params,
-                            time: lt.seconds(),
-                            layer_size,
-                            seed: g.uid as u32,
-                            adjustment,
-                            env: EffectEnv { host: Some(host), effect_index: *i, ..env },
-                        },
-                    })
-                    .collect();
-                let t0 = web_time::Instant::now();
-                if target.gpu(&steps) {
-                    if let Some(v) = timing.as_deref_mut() {
-                        let ms = t0.elapsed().as_secs_f64() * 1e3 / run.len() as f64;
-                        v.extend(run.iter().map(|(_, _, s)| (format!("{} (gpu)", s.id), ms)));
-                    }
-                    k += run.len();
-                    continue;
-                }
-            }
-            k += 1;
-            let params = self.effect_params(ctx, layer, g);
-            let host = FxHost { index: i, ..host };
-            let env = EffectEnv { host: Some(&host), effect_index: i, ..env };
-            let ectx = EffectCtx { params: &params, time: lt.seconds(), layer_size, seed: g.uid as u32, adjustment, env };
-            let t0 = web_time::Instant::now();
-            target.cpu(&mut |buf| {
-                let mut buf = effectcraft_effects::apply(spec, &ectx, buf);
-                // 8/16 bpc effects write integer pixels.
-                self.pipe.quantize(&mut buf.img);
-                buf
-            });
-            if let Some(v) = timing.as_deref_mut() {
-                v.push((spec.id.to_string(), t0.elapsed().as_secs_f64() * 1e3));
-            }
-        }
-    }
-
-    /// Source pixels of a layer in layer space (before masks/effects).
-    fn source(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Buf> {
-        let s = self.opts.scale;
-        match &layer.source {
-            LayerSource::Solid { item } => {
-                let ItemKind::Solid(sol) = &self.project.item(*item)?.kind else { return None };
-                let w = ((sol.width as f64 * s).ceil() as u32).max(1);
-                let h = ((sol.height as f64 * s).ceil() as u32).max(1);
-                if layer.switches.adjustment {
-                    return Some(Buf { img: Image::filled(w, h, [1.0; 4]), offset: [0.0; 2], scale: s });
-                }
-                let mut c = sol.color;
-                if let Some(conv) = self.pipe.authored_in() {
-                    c = conv.apply(c);
-                }
-                let px = self.pipe.quantize_px([c[0], c[1], c[2], 1.0]);
-                Some(Buf { img: Image::filled(w, h, px), offset: [0.0; 2], scale: s })
-            }
-            LayerSource::Comp { item } => {
-                if self.project.comp_contains(*item, ctx.comp_id) {
-                    return None;
-                }
-                // A composition proxy (a rendered still or movie) stands in for the comp.
-                // Nothing before the nested comp starts or after it ends.
-                let lt = ctx.nested_time(layer);
-                if !self.project.comp(*item).is_some_and(|nc| nc.covers(lt)) {
-                    return None;
-                }
-                if let Some(pf) = self.proxy_for(*item)
-                    && let Some(nc) = self.project.comp(*item)
-                {
-                    let img = self.footage.frame_with(*item, pf, lt, None, self.pipe.float_encoding())?;
-                    return Some(self.footage_buf(&img, pf, nc.width, nc.height));
-                }
-                // Essential Properties overrides render the nested comp with this instance's
-                // values.
-                let ov = essential_overrides(ctx, layer);
-                let tmp = if ov.is_empty() { None } else { effectcraft_project::essential::with_overrides(self.project, *item, &ov) };
-                // Preserve resolution when nested: drawn at full size even when this comp renders
-                // smaller (the buffer's scale places it).
-                let full = s < 1.0 && self.project.comp(*item).is_some_and(|nc| nc.preserve_resolution);
-                let bs = if full { 1.0 } else { s };
-                let base = self.nested_through(layer);
-                let base = Renderer { opts: RenderOpts { scale: bs, ..base.opts }, ..base };
-                let sub = match &tmp {
-                    Some(p) => Renderer { project: p, ..base },
-                    None => base,
-                };
-                // Frame blending between the nested comp's frames (time-stretched/remapped).
-                let mode = frame_blend_mode(ctx, layer);
-                if mode != FrameBlend::Off
-                    && let Some(nc) = self.project.comp(*item)
-                {
-                    let (i, w) = frame_position(lt, nc.frame_rate);
-                    if w > 1e-6 {
-                        let a = sub.comp_frame(*item, nc.frame_rate.tick_of(i));
-                        let b = sub.comp_frame(*item, nc.frame_rate.tick_of(i + 1));
-                        return Some(Buf { img: blend_frames(mode, &a, &b, w as f32), offset: [0.0; 2], scale: bs });
-                    }
-                }
-                Some(Buf { img: sub.comp_frame(*item, lt), offset: [0.0; 2], scale: bs })
-            }
-            LayerSource::Footage { item } => {
-                let it = self.project.item(*item)?;
-                let ItemKind::Footage(f) = &it.kind else { return None };
-                if !f.has_video {
-                    return None;
-                }
-                // Continuously rasterised vector footage: drawn at the on-screen scale.
-                if layer.switches.collapse && is_vector_footage(f) {
-                    let k = self.raster_scale(ctx, layer);
-                    if let Some(img) = self.footage.vector_frame(*item, f, k) {
-                        let mut buf = Buf { img: (*img).clone(), offset: [0.0; 2], scale: k };
-                        if let Some(c) = self.pipe.media_in(f) {
-                            color::convert(&mut buf.img, &c);
-                        }
-                        return Some(buf);
-                    }
-                }
-                let lt = ctx.source_time(layer);
-                // The proxy is decoded instead, at its own size, and fills the footage's frame.
-                let proxy = self.proxy_for(*item);
-                let pf = proxy.unwrap_or(f);
-                let size = self.reduced_size(f.width, f.height).filter(|_| proxy.is_none());
-                let img = self.footage_frame(ctx, layer, *item, pf, lt, size)?;
-                Some(self.footage_buf(&img, pf, f.width, f.height))
-            }
-            LayerSource::Text => Some(self.authored(text::render(ctx, layer, self.raster_scale(ctx, layer)))),
-            LayerSource::Shape => layer.props.sub("contents").map(|c| self.authored(shapes::render(ctx, layer, c, self.raster_scale(ctx, layer)))),
-            _ => None,
-        }
-    }
-
-    /// The proxy footage used for `item` under this render's Proxy Use, if any.
-    pub fn proxy_for(&self, item: ItemId) -> Option<&'a Footage> {
-        let it = self.project.item(item)?;
-        let px = it.proxy.as_deref()?;
-        (self.opts.proxy.uses(matches!(it.kind, ItemKind::Comp(_)), px.enabled) && px.footage.has_video).then_some(&px.footage)
-    }
-
-    /// A decoded frame of `f` as a layer buffer covering `w`×`h` layer pixels (the footage's
-    /// nominal size; proxies are scaled up to it), converted from its colour profile.
-    fn footage_buf(&self, img: &Image, f: &Footage, w: u32, h: u32) -> Buf {
-        let s = self.opts.scale;
-        let k = if img.width > 0 { w.max(1) as f64 / img.width as f64 } else { 1.0 };
-        // Keep native pixels when downsampling is small; resample otherwise.
-        let mut buf = match self.reduced_size(w, h) {
-            // The source resampled it already (`FootageSource::frame_at_size`).
-            Some(size) if (img.width, img.height) == size => Buf { img: img.clone(), offset: [0.0; 2], scale: s },
-            Some((rw, rh)) if k <= 1.0 + 1e-9 => Buf { img: effectcraft_raster::resample(img, rw, rh), offset: [0.0; 2], scale: s },
-            _ => Buf { img: img.clone(), offset: [0.0; 2], scale: 1.0 / k },
-        };
-        if let Some(c) = self.pipe.media_in(f) {
-            color::convert(&mut buf.img, &c);
-        }
-        buf
-    }
-
-    /// The size of `w` × `h` layer pixels in this render when it is reduced enough that footage
-    /// is resampled to it (below 3/4 scale).
-    fn reduced_size(&self, w: u32, h: u32) -> Option<(u32, u32)> {
-        let s = self.opts.scale;
-        (s < 0.75).then(|| (((w as f64 * s).round() as u32).max(1), ((h as f64 * s).round() as u32).max(1)))
-    }
-
-    /// Authored colours into the working space (linear working spaces).
-    fn authored(&self, mut buf: Buf) -> Buf {
-        if let Some(c) = self.pipe.authored_in() {
-            color::convert(&mut buf.img, &c);
-        }
-        buf
-    }
-
-    /// A footage frame at source time `t`, frame-blended between the two nearest source frames
-    /// when the layer's Frame Blending switch (and the comp's Enable Frame Blending) is on and
-    /// `t` falls between frames (footage rate ≠ comp rate, time stretch, time remapping).
-    /// `size`: a plain frame may come resampled to it ([`FootageSource::frame_at_size`]).
-    fn footage_frame(&self, ctx: &EvalCtx, layer: &Layer, item: ItemId, f: &Footage, t: Tick, size: Option<(u32, u32)>) -> Option<Arc<Image>> {
-        // Interpret Footage ▸ Separate Fields: each field is a frame at twice the rate.
-        if f.fields != effectcraft_project::FieldOrder::Off && matches!(f.kind, FootageKind::Video | FootageKind::Sequence) {
-            let field_rate = FrameRate::new(f.frame_rate.num * 2, f.frame_rate.den);
-            let i = field_rate.frame_at(t).max(0);
-            let img = self.footage.frame_with(item, f, f.frame_rate.tick_of(i / 2), None, self.pipe.float_curve(f))?;
-            let dominant_upper = f.fields == effectcraft_project::FieldOrder::UpperFirst;
-            // Upper field = even lines (0, 2, …).
-            let parity = if (i % 2 == 0) == dominant_upper { 0 } else { 1 };
-            return Some(Arc::new(interpret_pixels(&field_frame(&img, parity), f, self.pipe.linear_footage_space(f))));
-        }
-        // Interpretation is per pixel but not linear: it runs on the frame before resampling.
-        let size = size.filter(|_| !(f.invert_alpha || f.linear_light_applies()));
-        let img = self.footage_frame_raw(ctx, layer, item, f, t, size)?;
-        if f.invert_alpha || f.linear_light_applies() { Some(Arc::new(interpret_pixels(&img, f, self.pipe.linear_footage_space(f)))) } else { Some(img) }
-    }
-
-    fn footage_frame_raw(&self, ctx: &EvalCtx, layer: &Layer, item: ItemId, f: &Footage, t: Tick, size: Option<(u32, u32)>) -> Option<Arc<Image>> {
-        let mode = frame_blend_mode(ctx, layer);
-        let float = self.pipe.float_curve(f);
-        if mode != FrameBlend::Off && matches!(f.kind, FootageKind::Video | FootageKind::Sequence) {
-            let (i, w) = frame_position(t, f.frame_rate);
-            if w > 1e-6 {
-                // Blended frames are cached (Pixel Motion is expensive).
-                let key = self.cache.map(|_| {
-                    use std::hash::{Hash, Hasher};
-                    let mut h = std::collections::hash_map::DefaultHasher::new();
-                    (0x00f8_a3e5_u64, item, i, (w as f32).to_bits(), mode as u8, f.frame_rate.num, f.frame_rate.den, &f.path, float).hash(&mut h);
-                    h.finish()
-                });
-                if let (Some(c), Some(k)) = (self.cache, key)
-                    && let Some(b) = c.get(k)
-                {
-                    return Some(Arc::new(b.img.clone()));
-                }
-                let a = self.footage.frame_with(item, f, f.frame_rate.tick_of(i), None, float);
-                let b = self.footage.frame_with(item, f, f.frame_rate.tick_of(i + 1), None, float);
-                if let (Some(a), Some(b)) = (a, b) {
-                    let img = blend_frames(mode, &a, &b, w as f32);
-                    if let (Some(c), Some(k)) = (self.cache_to_keep(), key) {
-                        c.insert(k, Arc::new(Buf { img: img.clone(), offset: [0.0; 2], scale: 1.0 }));
-                    }
-                    return Some(Arc::new(img));
-                }
-            }
-        }
-        self.footage.frame_with(item, f, t, size, float)
-    }
-
-    /// Source → masks, clamped/quantised to the project depth.
-    fn masked_source(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Buf> {
-        let mut buf = match self.content_times(ctx, layer) {
-            Some(times) => self.blurred_source(ctx, layer, &times)?,
-            None => self.source(ctx, layer)?,
-        };
-        // A solid is filled with a quantised colour: only masks can take it off the grid.
-        let solid = matches!(layer.source, LayerSource::Solid { .. });
-        if masks::apply(ctx, layer, &mut buf, self.mask_blur(ctx, layer)) || !solid {
-            self.pipe.quantize(&mut buf.img);
-        }
-        Some(buf)
-    }
-
-    /// Fully processed layer buffer (source → masks → effects → layer styles, flattened).
-    /// Served from the layer cache when the layer's content key matches.
-    pub fn layer_buf(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Arc<Buf>> {
-        self.layer_buf_keyed(ctx, layer).map(|(b, _)| b)
-    }
-
-    /// [`Self::layer_buf`] in the blending space (linear with Blend Colors Using 1.0 Gamma).
-    pub fn blend_layer_buf(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Arc<Buf>> {
-        let (b, k) = self.layer_buf_keyed(ctx, layer)?;
-        Some(self.to_blend(b, k))
-    }
-
-    /// A buffer converted to the blending space (cached under a key derived from `key`).
-    pub(crate) fn to_blend(&self, b: Arc<Buf>, key: Option<u64>) -> Arc<Buf> {
-        let Some(c) = self.pipe.to_blend() else { return b };
-        let key = key.map(|k| cache::derive(k, 0x1ea7));
-        if let (Some(cache), Some(k)) = (self.cache, key)
-            && let Some(x) = cache.get(k)
-        {
-            return x;
-        }
-        let mut nb = (*b).clone();
-        color::convert(&mut nb.img, &c);
-        let nb = Arc::new(nb);
-        // The buffer the cache keeps (another worker's, if it kept one first).
-        match (self.cache_to_keep(), key) {
-            (Some(cache), Some(k)) => cache.insert(k, nb),
-            _ => nb,
-        }
-    }
-
-    fn layer_buf_keyed(&self, ctx: &EvalCtx, layer: &Layer) -> Option<(Arc<Buf>, Option<u64>)> {
-        let st = self.styled(ctx, layer, None)?;
-        if st.passes.is_empty() {
-            return Some((st.body, st.key));
-        }
-        let key = st.key.map(|k| cache::derive(k, 0xf1a7));
-        if let (Some(c), Some(k)) = (self.cache, key)
-            && let Some(b) = c.get(k)
-        {
-            return Some((b, key));
-        }
-        let flat = Arc::new(styles::Styled { passes: st.passes.iter().map(|(b, m)| ((**b).clone(), *m)).collect(), body: (*st.body).clone() }.flatten());
-        // The buffer the cache keeps (another worker's, if it kept one first).
-        let flat = match (self.cache_to_keep(), key) {
-            (Some(c), Some(k)) => c.insert(k, flat),
-            _ => flat,
-        };
-        Some((flat, key))
-    }
-
-    /// A layer's source pixels at the context time, before masks, effects and the transform
-    /// (what the motion tracker analyses, like After Effects' Layer panel). `None` for layers
-    /// without pixels.
-    pub fn layer_source(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Buf> {
-        self.source(ctx, layer)
-    }
-
-    /// Layer pixels after source → masks → effects (no layer styles).
-    pub fn content_buf(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Arc<Buf>> {
-        self.content_buf_timed(ctx, layer, None).map(|(b, _)| b)
-    }
-
-    fn content_buf_timed(&self, ctx: &EvalCtx, layer: &Layer, mut timing: Option<&mut LayerTiming>) -> Option<(Arc<Buf>, Option<u64>)> {
-        let key = self.cache.and_then(|_| cache::layer_key(ctx, layer, self.raster_scale(ctx, layer), self.opts.draft, self.mb_on(ctx, layer)));
-        let key = self.content_key(ctx, layer, key);
-        if let (Some(c), Some(k)) = (self.cache, key)
-            && let Some(b) = c.get(k)
-        {
-            if let Some(t) = timing.as_deref_mut() {
-                t.cached = true;
-            }
-            return Some((b, key));
-        }
-        let buf = self.masked_source(ctx, layer)?;
-        let buf = Arc::new(self.apply_effects_timed(ctx, layer, buf, false, usize::MAX, timing.map(|t| &mut t.effects)));
-        // The buffer the cache keeps (another worker's, if it kept one first).
-        let buf = match (self.cache_to_keep(), key) {
-            (Some(c), Some(k)) => c.insert(k, buf),
-            _ => buf,
-        };
-        Some((buf, key))
-    }
-
-    /// A layer's input at the context time: source → masks → its first `effects` effects
-    /// (what Time effects read at neighbouring times), in effect space (see [`effect_bounds`]):
-    /// what effect `effects` sees. Served from / stored in the layer cache under its own key,
-    /// so scrubbing reuses frames rendered for earlier output frames.
-    pub fn layer_input(&self, ctx: &EvalCtx, layer: &Layer, effects: usize) -> Option<Arc<Buf>> {
-        let key = self.cache.and_then(|_| cache::input_key(ctx, layer, self.raster_scale(ctx, layer), self.opts.draft, self.mb_on(ctx, layer), effects));
-        let key = self.content_key(ctx, layer, key);
-        if let (Some(c), Some(k)) = (self.cache, key)
-            && let Some(b) = c.get(k)
-        {
-            return Some(b);
-        }
-        let mut buf = self.masked_source(ctx, layer)?;
-        let origin = ctx.effect_bounds(layer).1;
-        buf.rebase(origin);
-        if effects > 0 {
-            buf = self.effect_space_stack(ctx, layer, buf, false, effects, None, origin);
-        }
-        let buf = Arc::new(buf);
-        // The buffer the cache keeps (another worker's, if it kept one first).
-        let buf = match (self.cache_to_keep(), key) {
-            (Some(c), Some(k)) => c.insert(k, buf),
-            _ => buf,
-        };
-        Some(buf)
-    }
-
-    /// The layer with its styles: exterior passes and body (cached per pass).
-    fn styled(&self, ctx: &EvalCtx, layer: &Layer, mut timing: Option<&mut LayerTiming>) -> Option<StyledLayer> {
-        let (content, ckey) = self.content_buf_timed(ctx, layer, timing.as_deref_mut())?;
-        if !styles::active(ctx, layer) {
-            return Some(StyledLayer { passes: vec![], body: content.clone(), content, key: ckey, ckey, plain: true });
-        }
-        let modes = styles::pass_modes(ctx, layer);
-        let key = ckey.map(|k| cache::styles_key(ctx, layer, k));
-        if let (Some(c), Some(k)) = (self.cache, key)
-            && let Some(body) = c.get(k)
-        {
-            let passes: Option<Vec<_>> = modes.iter().enumerate().map(|(i, m)| c.get(cache::derive(k, i as u64 + 1)).map(|b| (b, *m))).collect();
-            if let Some(passes) = passes {
-                return Some(StyledLayer { passes, body, content, key, ckey, plain: false });
-            }
-        }
-        let t0 = web_time::Instant::now();
-        let size = source_size(self.project, layer);
-        let layer_size = if size.0 == 0 { [ctx.comp.width as f64, ctx.comp.height as f64] } else { [size.0 as f64, size.1 as f64] };
-        let st = styles::render(ctx, layer, &content, layer_size);
-        if let Some(t) = timing {
-            t.cached = false;
-            t.effects.push(("layerStyles".into(), t0.elapsed().as_secs_f64() * 1e3));
-        }
-        let mut body = Arc::new(st.body);
-        let mut passes: Vec<_> = st.passes.into_iter().map(|(b, m)| (Arc::new(b), m)).collect();
-        // The buffers the cache keeps (another worker's, if it kept them first).
-        if let (Some(c), Some(k)) = (self.cache_to_keep(), key) {
-            body = c.insert(k, body);
-            for (i, (b, _)) in passes.iter_mut().enumerate() {
-                *b = c.insert(cache::derive(k, i as u64 + 1), b.clone());
-            }
-        }
-        Some(StyledLayer { passes, body, content, key, ckey, plain: false })
-    }
-
-    /// The styled layer's buffers in the blending space.
-    fn styled_to_blend(&self, st: StyledLayer) -> StyledLayer {
-        if self.pipe.to_blend().is_none() {
-            return st;
-        }
-        let body = self.to_blend(st.body, st.key);
-        let content = if st.plain { body.clone() } else { self.to_blend(st.content, st.ckey) };
-        let passes = st.passes.into_iter().enumerate().map(|(i, (b, m))| (self.to_blend(b, st.key.map(|k| cache::derive(k, i as u64 + 1))), m)).collect();
-        StyledLayer { passes, body, content, ..st }
-    }
-
-    fn sampling(&self, layer: &Layer) -> effectcraft_raster::Sampling {
-        if self.quality(layer) == Quality::Draft {
-            // Draft quality: no interpolation (nearest neighbour), as After Effects' Draft.
-            effectcraft_raster::Sampling::Nearest
-        } else if self.opts.draft {
-            effectcraft_raster::Sampling::Bilinear
-        } else if layer.switches.sampling == Sampling::Bicubic {
-            effectcraft_raster::Sampling::Bicubic
-        } else {
-            effectcraft_raster::Sampling::Bilinear
-        }
-    }
-
-    /// The region of interest of a top-level 2D frame: (x, y) offset of the output in output
-    /// pixels and its size. `None` renders the whole comp (no ROI, or a nested comp).
-    pub(crate) fn roi_offset(&self) -> Option<(f64, f64, u32, u32)> {
-        let r = self.opts.roi.filter(|_| self.top)?;
-        let s = self.opts.scale;
-        if r[2] <= 0.0 || r[3] <= 0.0 {
-            return None;
-        }
-        Some(((r[0] * s).round(), (r[1] * s).round(), ((r[2] * s).round() as u32).max(1), ((r[3] * s).round() as u32).max(1)))
-    }
-
-    /// The region of interest's offset in output pixels for 3D projection (0 without one).
-    pub(crate) fn out_offset(&self) -> (f64, f64) {
-        self.roi_offset().map_or((0.0, 0.0), |(x, y, _, _)| (x, y))
-    }
-
-    /// Scaled comp pixel → output pixel: the region of interest's offset.
-    fn out_matrix(&self) -> Mat3 {
-        match self.roi_offset() {
-            Some((x, y, _, _)) => Mat3::translate(vec2(-x, -y)),
-            None => Mat3::IDENTITY,
-        }
-    }
-
-    /// Buffer pixel → output pixel matrix for the layer at the context time.
-    fn buf_matrix(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf) -> Mat3 {
-        let (l2c, _) = ctx.layer_to_comp(layer);
-        self.place_matrix(self.outer.map_or(l2c, |o| o * l2c), buf)
-    }
-
-    /// Buffer pixel → output pixel matrix for a layer → (top-level) comp matrix.
-    fn place_matrix(&self, l2c: Mat3, buf: &Buf) -> Mat3 {
-        let s = self.opts.scale;
-        self.out_matrix()
-            * Mat3::scale(vec2(s, s))
-            * l2c
-            * Mat3::scale(vec2(1.0 / buf.scale, 1.0 / buf.scale))
-            * Mat3::translate(vec2(-buf.offset[0], -buf.offset[1]))
-    }
-
-    /// The collapsed precomp layers this comp is drawn through, outermost first.
-    fn links(&self) -> impl Iterator<Item = &Through<'a>> {
-        self.through.iter().map_while(Option::as_ref)
-    }
-
-    /// The shutter of a layer's motion blur: its comp's, or for a collapsed precomp's layers the
-    /// outermost containing comp's.
-    fn shutter(&self, ctx: &EvalCtx) -> Shutter {
-        let c: &Comp = match self.links().next() {
-            Some(l) => l.comp,
-            None => ctx.comp,
-        };
-        Shutter {
-            angle: c.shutter_angle / 360.0,
-            phase: c.shutter_phase / 360.0,
-            frame: c.frame_duration().seconds(),
-            samples: c.motion_blur_samples,
-            limit: c.motion_blur_adaptive_limit,
-        }
-    }
-
-    /// Whether a layer moves within the shutter: its own motion blur, or that of a collapsed
-    /// precomp layer it is drawn through.
-    fn blurred(&self, ctx: &EvalCtx, layer: &Layer) -> bool {
-        self.mb_on(ctx, layer) || (!self.through_lost && self.links().any(|l| l.blur))
-    }
-
-    /// The collapsed precomps' matrix (nested comp → the frame's comp) and the nested comp's time
-    /// `dt` seconds into the outermost comp's shutter: each precomp layer moves if it is motion
-    /// blurred, and times map down through each one (stretch, time remapping).
-    fn outer_at(&self, ctx: &EvalCtx, dt: f64) -> (Option<Mat3>, Tick) {
-        let shift = Tick::from_seconds_f64(dt);
-        let mut outer: Option<Mat3> = None;
-        let mut t: Option<Tick> = None;
-        for l in self.links() {
-            let at = EvalCtx { comp_id: l.comp_id, comp: l.comp, time: t.unwrap_or(l.time + shift), ..*ctx };
-            let (m, _) = if l.blur { at.layer_to_comp(l.layer) } else { EvalCtx { time: l.time, ..at }.layer_to_comp(l.layer) };
-            outer = Some(outer.map_or(m, |o| o * m));
-            t = Some(at.nested_time(l.layer));
-        }
-        (outer, t.unwrap_or(ctx.time + shift))
-    }
-
-    /// [`Self::buf_matrix`] for the motion-blur sub-sample `dt` seconds into the shutter: the
-    /// layer moves if it is motion blurred, the collapsed precomps above it if theirs are.
-    fn buf_matrix_at(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf, dt: f64) -> Mat3 {
-        if self.through_lost || self.links().next().is_none() {
-            return self.buf_matrix(&ctx.at(ctx.time + Tick::from_seconds_f64(dt)), layer, buf);
-        }
-        let (outer, t) = self.outer_at(ctx, dt);
-        let lctx = if self.mb_on(ctx, layer) { ctx.at(t) } else { *ctx };
-        let (l2c, _) = lctx.layer_to_comp(layer);
-        self.place_matrix(outer.map_or(l2c, |o| o * l2c), buf)
-    }
-
-    /// Shape and text content that animates within the shutter (paths, Trim Paths, text
-    /// animators…) of a motion-blurred layer: the times its source is drawn at and averaged,
-    /// Samples Per Frame of them, as After Effects does for shape layers. `None` when the content
-    /// holds still (compared through its cache key, which leaves the transform out).
-    fn content_times(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Vec<Tick>> {
-        if !matches!(layer.source, LayerSource::Shape | LayerSource::Text) || !self.mb_on(ctx, layer) {
-            return None;
-        }
-        let sh = self.shutter(ctx);
-        if sh.angle <= 0.0 {
-            return None;
-        }
-        let n = if self.opts.draft { 4 } else { (sh.samples as usize).clamp(2, 64) };
-        let times: Vec<Tick> = (0..n).map(|i| self.outer_at(ctx, sh.offset(i, n)).1).collect();
-        let key = |t: Tick| cache::layer_key(&ctx.at(t), layer, 1.0, false, false);
-        let k0 = key(*times.first()?)?;
-        let moves = [times.get(n / 2), times.last()].into_iter().flatten().any(|t| key(*t) != Some(k0));
-        moves.then_some(times)
-    }
-
-    /// The layer's source drawn at each of `times` and averaged (premultiplied) on the union of
-    /// their bounds. Content that also changes its raster scale within the shutter, or would need
-    /// an outsized buffer, is drawn once.
-    fn blurred_source(&self, ctx: &EvalCtx, layer: &Layer, times: &[Tick]) -> Option<Buf> {
-        let bufs: Vec<Buf> = times.iter().filter_map(|t| self.source(&ctx.at(*t), layer)).collect();
-        let scale = bufs.first()?.scale;
-        // Pixel = layer point × scale + offset: with the largest offset every buffer lands at
-        // x + (off - its offset) ≥ 0.
-        let off = [0, 1].map(|i| bufs.iter().map(|b| b.offset[i]).fold(f64::MIN, f64::max));
-        let w = bufs.iter().map(|b| off[0] - b.offset[0] + b.img.width as f64).fold(0.0, f64::max).ceil();
-        let h = bufs.iter().map(|b| off[1] - b.offset[1] + b.img.height as f64).fold(0.0, f64::max).ceil();
-        if bufs.iter().any(|b| (b.scale - scale).abs() > 1e-9) || !(w * h).is_finite() || w * h > (1u64 << 26) as f64 {
-            return self.source(ctx, layer);
-        }
-        let mut acc = Image::new(w as u32, h as u32);
-        let k = 1.0 / bufs.len() as f32;
-        for b in &bufs {
-            let m = Mat3::translate(vec2(off[0] - b.offset[0], off[1] - b.offset[1]));
-            effectcraft_raster::accumulate_warp(&mut acc, &b.img, &m, effectcraft_raster::Sampling::Bilinear, k);
-        }
-        Some(Buf { img: acc, offset: off, scale })
-    }
-
-    /// A processed-layer cache key that also covers content motion blur (the averaged source
-    /// depends on the content at every sub-sample).
-    fn content_key(&self, ctx: &EvalCtx, layer: &Layer, key: Option<u64>) -> Option<u64> {
-        let k = key?;
-        let Some(times) = self.content_times(ctx, layer) else { return Some(k) };
-        times.iter().try_fold(cache::derive(k, 0x6d62_6c72), |d, t| Some(cache::derive(d, cache::layer_key(&ctx.at(*t), layer, 1.0, false, false)?)))
-    }
-
-    /// Whether a layer is motion blurred: the render options, the comp's switch and the layer's
-    /// switch (limited by the precomp layers above when switches affect nested comps). Layer
-    /// motion, mask motion blur, effects that read the shutter and Advanced 3D all ask this.
-    pub(crate) fn mb_on(&self, ctx: &EvalCtx, layer: &Layer) -> bool {
-        self.opts.motion_blur && ctx.comp.enable_motion_blur && self.layer_motion_blur(layer)
-    }
-
-    /// What a layer's mask motion blur may do in this render (see [`masks::MaskBlur`]).
-    fn mask_blur(&self, ctx: &EvalCtx, layer: &Layer) -> masks::MaskBlur {
-        masks::MaskBlur {
-            allowed: self.opts.motion_blur && ctx.comp.enable_motion_blur && self.inherited.is_none_or(|(_, mb)| mb),
-            layer: self.layer_motion_blur(layer),
-            samples: if self.opts.draft { 4 } else { ctx.comp.motion_blur_samples as usize },
-        }
-    }
-
-    /// Motion-blur sub-samples for a layer buffer (1 = no motion blur). As in After Effects, a 2D
-    /// layer gets about one sample per output pixel its corners travel during the shutter,
-    /// at least Samples Per Frame and at most the comp's Adaptive Sample Limit; a layer that
-    /// does not move within the shutter is drawn once.
-    fn mb_samples(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf) -> usize {
-        if !self.blurred(ctx, layer) {
-            return 1;
-        }
-        let travel = self.shutter_travel(ctx, layer, buf);
-        if travel < 1e-3 {
-            return 1;
-        }
-        if self.opts.draft {
-            return 4;
-        }
-        let sh = self.shutter(ctx);
-        adaptive_samples(travel, sh.samples, sh.limit)
-    }
-
-    /// Largest distance (output pixels) a corner of the layer buffer moves during the shutter,
-    /// measured along the path at a few points.
-    fn shutter_travel(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf) -> f64 {
-        let sh = self.shutter(ctx);
-        let (w, h) = (buf.img.width as f64, buf.img.height as f64);
-        let corners = [(0.0, 0.0), (w, 0.0), (0.0, h), (w, h), (w * 0.5, h * 0.5)];
-        const PROBES: usize = 8;
-        let mut prev: Option<Vec<effectcraft_geom::Vec2>> = None;
-        let mut travel = vec![0.0f64; corners.len()];
-        for i in 0..PROBES {
-            let m = self.buf_matrix_at(ctx, layer, buf, sh.offset(i, PROBES));
-            let pts: Vec<_> = corners.iter().map(|&(x, y)| m.apply(vec2(x, y))).collect();
-            if let Some(p) = &prev {
-                for (k, (a, b)) in p.iter().zip(&pts).enumerate() {
-                    travel[k] += (b.x - a.x).hypot(b.y - a.y);
-                }
-            }
-            prev = Some(pts);
-        }
-        travel.into_iter().fold(0.0, f64::max)
-    }
-
-    /// Canvas pixels that compositing `buf` for `layer` can change: the transformed buffer's
-    /// bounds plus the resampling footprint. Stencil/silhouette modes, motion blur and
-    /// perspective fall back to the whole canvas.
-    ///
-    /// A quantised buffer placed pixel-exactly (integer translation, Normal, 100%) over a blank
-    /// canvas leaves exactly its own (quantised) pixels: nothing to re-quantise.
-    fn footprint(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf, opacity: f32, blank: bool) -> Region {
-        if layer.blend_mode.is_stencil() || self.mb_samples(ctx, layer, buf) > 1 {
-            return Region::Full;
-        }
-        let m = self.buf_matrix(ctx, layer, buf);
-        if !m.is_affine() {
-            return Region::Full;
-        }
-        let matte = layer.track_matte.is_some_and(|tm| tm.layer != layer.id && ctx.comp.layer(tm.layer).is_some());
-        let k = &m.0;
-        let integral = |v: f64| v == v.round();
-        if blank
-            && layer.blend_mode == BlendMode::Normal
-            && opacity == 1.0
-            && !matte
-            && !layer.preserve_transparency
-            && self.pipe.to_blend().is_none()
-            && k[0][0] == 1.0
-            && k[1][1] == 1.0
-            && k[0][1] == 0.0
-            && k[1][0] == 0.0
-            && integral(k[0][2])
-            && integral(k[1][2])
-        {
-            return Region::Empty;
-        }
-        let (w, h) = (buf.img.width as f64, buf.img.height as f64);
-        let c = [(0.0, 0.0), (w, 0.0), (0.0, h), (w, h)].map(|(x, y)| m.apply(vec2(x, y)));
-        let (x0, x1) = (c.iter().map(|p| p.x).fold(f64::INFINITY, f64::min), c.iter().map(|p| p.x).fold(f64::NEG_INFINITY, f64::max));
-        let (y0, y1) = (c.iter().map(|p| p.y).fold(f64::INFINITY, f64::min), c.iter().map(|p| p.y).fold(f64::NEG_INFINITY, f64::max));
-        color::PxRect::covering(x0, y0, x1, y1, 3.0).map_or(Region::Full, Region::Rect)
-    }
-
-    /// How a processed layer buffer lands in the output: one buffer → output matrix, or one per
-    /// motion-blur sub-sample (averaged), with the layer's sampling filter and dissolve seed.
-    pub fn placement(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf) -> Placement {
-        let samples = self.mb_samples(ctx, layer, buf);
-        let (sampling, seed) = (self.sampling(layer), layer.id.0 as u32);
-        if samples <= 1 {
-            return Placement { matrices: vec![self.buf_matrix(ctx, layer, buf)], sampling, seed };
-        }
-        let sh = self.shutter(ctx);
-        let matrices = (0..samples).map(|i| self.buf_matrix_at(ctx, layer, buf, sh.offset(i, samples))).collect();
-        Placement { matrices, sampling, seed }
-    }
-
-    /// Draw a processed layer into `target` (transform, motion blur) with `mode`/`opacity`.
-    fn place(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf, target: &mut Image, mode: BlendMode, opacity: f32) {
-        let pl = self.placement(ctx, layer, buf);
-        let opts = WarpOpts { sampling: pl.sampling, opacity, mode, seed: pl.seed, clip: None };
-        if let [m] = pl.matrices.as_slice() {
-            composite_warp(target, &buf.img, m, &opts);
-            return;
-        }
-        // Sub-samples sum straight into one buffer (each warp is row-parallel).
-        let mut acc = Image::new(target.width, target.height);
-        let k = 1.0 / pl.matrices.len() as f32;
-        for m in &pl.matrices {
-            effectcraft_raster::accumulate_warp(&mut acc, &buf.img, m, opts.sampling, k);
-        }
-        target.blend_from(&acc, mode, opacity, pl.seed);
-    }
-
-    /// Draw a 2D layer into `canvas`; returns the region it may have changed.
-    fn draw_layer(&self, ctx: &EvalCtx, layer: &Layer, canvas: &mut Image, blank: bool) -> Region {
-        let opacity = ctx.opacity(layer) as f32 * self.opacity_mul;
-        if self.quality(layer) == Quality::Wireframe && !layer.switches.adjustment {
-            self.draw_wireframe(ctx, layer, canvas);
-            return Region::Full;
-        }
-        if opacity <= 0.0 && !layer.switches.adjustment {
-            return Region::Empty;
-        }
-        if layer.switches.adjustment {
-            self.draw_adjustment(ctx, layer, canvas, opacity);
-            return Region::Full;
-        }
-        let mut timing = self.profile.map(|_| LayerTiming { depth: self.depth, layer: layer.name.clone(), ..Default::default() });
-        let t0 = web_time::Instant::now();
-        let Some(st) = self.styled(ctx, layer, timing.as_mut()) else { return Region::Empty };
-        let st = self.styled_to_blend(st);
-        let t1 = web_time::Instant::now();
-        let changed = if st.plain {
-            self.composite_layer(ctx, layer, &st.body, canvas, opacity);
-            self.footprint(ctx, layer, &st.body, opacity, blank)
-        } else {
-            self.composite_styled(ctx, layer, &st, canvas, opacity);
-            Region::Full
-        };
-        if let (Some(prof), Some(mut timing)) = (self.profile, timing) {
-            timing.process_ms = (t1 - t0).as_secs_f64() * 1e3;
-            timing.composite_ms = t1.elapsed().as_secs_f64() * 1e3;
-            if let Ok(mut v) = prof.lock() {
-                v.push(timing);
-            }
-        }
-        changed
-    }
-
-    /// Composite a styled layer: exterior passes with their own modes, then the body with the
-    /// layer's mode; the layer's opacity fades the whole stack. Knockout clears what is below the
-    /// layer's content; switched-off R/G/B channels keep the values below.
-    fn composite_styled(&self, ctx: &EvalCtx, layer: &Layer, st: &StyledLayer, canvas: &mut Image, opacity: f32) {
-        let bl = styles::blending(ctx, layer);
-        let matte = layer.track_matte.is_some_and(|tm| tm.layer != layer.id && ctx.comp.layer(tm.layer).is_some());
-        if matte || layer.preserve_transparency {
-            let mut iso = Image::new(canvas.width, canvas.height);
-            for (b, m) in &st.passes {
-                self.place(ctx, layer, b, &mut iso, *m, 1.0);
-            }
-            self.place(ctx, layer, &st.body, &mut iso, BlendMode::Normal, 1.0);
-            self.composite_iso(ctx, layer, iso, canvas, opacity);
-            return;
-        }
-        let mut tmp = canvas.clone();
-        if bl.knockout > 0 {
-            let mut k = Image::new(canvas.width, canvas.height);
-            self.place(ctx, layer, &st.content, &mut k, BlendMode::Normal, 1.0);
-            tmp.data.par_iter_mut().zip(k.data.par_iter()).for_each(|(p, q)| {
-                let keep = 1.0 - q[3].clamp(0.0, 1.0);
-                for c in p.iter_mut() {
-                    *c *= keep;
-                }
-            });
-        }
-        for (b, m) in &st.passes {
-            self.place(ctx, layer, b, &mut tmp, *m, 1.0);
-        }
-        self.place(ctx, layer, &st.body, &mut tmp, layer.blend_mode, 1.0);
-        let ch = bl.channels;
-        canvas.data.par_iter_mut().zip(tmp.data.par_iter()).for_each(|(c, t)| {
-            for i in 0..4 {
-                let v = if i < 3 && !ch[i] { c[i] } else { t[i] };
-                c[i] += (v - c[i]) * opacity;
-            }
-        });
-    }
-
-    fn composite_layer(&self, ctx: &EvalCtx, layer: &Layer, buf: &Buf, canvas: &mut Image, opacity: f32) {
-        let matte = layer.track_matte.is_some_and(|tm| tm.layer != layer.id && ctx.comp.layer(tm.layer).is_some());
-        if !matte && !layer.preserve_transparency {
-            self.place(ctx, layer, buf, canvas, layer.blend_mode, opacity);
-            return;
-        }
-        // Render in isolation, then matte / preserve transparency, then blend.
-        let mut iso = Image::new(canvas.width, canvas.height);
-        self.place(ctx, layer, buf, &mut iso, BlendMode::Normal, 1.0);
-        self.composite_iso(ctx, layer, iso, canvas, opacity);
-    }
-
-    /// Apply the track matte / preserve transparency to an isolated layer render, then blend.
-    fn composite_iso(&self, ctx: &EvalCtx, layer: &Layer, iso: Image, canvas: &mut Image, opacity: f32) {
-        self.composite_iso_with(ctx, layer, iso, canvas, opacity, None);
-    }
-
-    /// [`Self::composite_iso`] with the track matte's pixels already drawn (`matte`, e.g. a 3D
-    /// matte seen through the camera); otherwise the matte layer is placed in 2D.
-    pub(crate) fn composite_iso_with(&self, ctx: &EvalCtx, layer: &Layer, mut iso: Image, canvas: &mut Image, opacity: f32, matte_img: Option<Image>) {
-        self.apply_track_matte(ctx, layer, &mut iso, matte_img);
-        if layer.preserve_transparency {
-            iso.data.par_iter_mut().zip(canvas.data.par_iter()).for_each(|(p, q)| {
-                for c in p.iter_mut() {
-                    *c *= q[3];
-                }
-            });
-        }
-        canvas.blend_from(&iso, layer.blend_mode, opacity, layer.id.0 as u32);
-    }
-
-    /// Multiply `img` (comp-sized) by the layer's track matte, if it has one; `matte_img` as in
-    /// [`Self::composite_iso_with`].
-    fn apply_track_matte(&self, ctx: &EvalCtx, layer: &Layer, img: &mut Image, matte_img: Option<Image>) {
-        let matte = layer.track_matte.and_then(|tm| ctx.comp.layer(tm.layer).filter(|m| m.id != layer.id).map(|m| (m, tm.kind)));
-        if let Some((m, kind)) = matte {
-            let mimg = match matte_img {
-                Some(i) if i.width == img.width && i.height == img.height => i,
-                _ => {
-                    let mut mimg = Image::new(img.width, img.height);
-                    if m.is_active_at(ctx.time)
-                        && let Some(mb) = self.layer_buf(ctx, m)
-                    {
-                        let mo = ctx.opacity(m) as f32;
-                        self.place(ctx, m, &mb, &mut mimg, BlendMode::Normal, mo);
-                    }
-                    mimg
-                }
-            };
-            img.data.par_iter_mut().zip(mimg.data.par_iter()).for_each(|(p, q)| {
-                let k = match kind {
-                    MatteKind::Alpha => q[3],
-                    MatteKind::AlphaInverted => 1.0 - q[3],
-                    MatteKind::Luma => effectcraft_color::luminance(q[0], q[1], q[2]),
-                    MatteKind::LumaInverted => 1.0 - effectcraft_color::luminance(q[0], q[1], q[2]),
-                }
-                .clamp(0.0, 1.0);
-                for c in p.iter_mut() {
-                    *c *= k;
-                }
-            });
-        }
-    }
-
-    /// Adjustment layer: effects applied to the comp below, limited to the layer's footprint
-    /// and its track matte.
-    fn draw_adjustment(&self, ctx: &EvalCtx, layer: &Layer, canvas: &mut Image, opacity: f32) {
-        let Some(mut foot) = self.source(ctx, layer) else { return };
-        let _ = masks::apply(ctx, layer, &mut foot, self.mask_blur(ctx, layer));
-        let mut matte = Image::new(canvas.width, canvas.height);
-        self.place(ctx, layer, &foot, &mut matte, BlendMode::Normal, 1.0);
-        self.apply_track_matte(ctx, layer, &mut matte, None);
-        let o = self.roi_offset().map(|(x, y, _, _)| [-x, -y]).unwrap_or([0.0; 2]);
-        let mut below = Buf { img: canvas.clone(), offset: o, scale: self.opts.scale };
-        // Effects run in the working space, not the linear blending space.
-        if let Some(c) = self.pipe.from_blend() {
-            color::convert(&mut below.img, &c);
-        }
-        let mut adjusted = self.apply_effects(ctx, layer, below, true);
-        // An effect that changed the frame (Motion Tile's Output size): back onto the canvas.
-        if let Some((dx, dy)) =
-            effectcraft_effects::adjustment_crop(adjusted.offset, o, (adjusted.img.width, adjusted.img.height), (canvas.width, canvas.height))
-        {
-            adjusted.img = adjusted.img.crop(dx, dy, canvas.width, canvas.height);
-        }
-        if let Some(c) = self.pipe.to_blend() {
-            color::convert(&mut adjusted.img, &c);
-        }
-        if adjusted.img.width != canvas.width || adjusted.img.height != canvas.height {
-            return;
-        }
-        canvas.data.par_iter_mut().zip(adjusted.img.data.par_iter()).zip(matte.data.par_iter()).for_each(|((c, a), m)| {
-            let k = m[3] * opacity;
-            for i in 0..4 {
-                c[i] += (a[i] - c[i]) * k;
-            }
-        });
-    }
-}
-
-/// A layer ready to composite (see [`Renderer::styled_layer`]).
-pub struct StyledLayer {
-    /// Exterior style passes (Drop Shadow, Outer Glow) with their blend modes.
-    pub passes: Vec<(Arc<Buf>, BlendMode)>,
-    pub body: Arc<Buf>,
-    /// Pre-style pixels (knockout shape).
-    pub content: Arc<Buf>,
-    /// Styled cache key (the content key when plain).
-    key: Option<u64>,
-    /// Content cache key.
-    ckey: Option<u64>,
-    /// No layer styles: composite `body` the usual way.
-    pub plain: bool,
-}
-
-/// Where a layer buffer lands (see [`Renderer::placement`]).
-#[derive(Clone, Debug)]
-pub struct Placement {
-    /// Buffer pixel → output pixel; several = motion-blur sub-samples (equal weights).
-    pub matrices: Vec<Mat3>,
-    pub sampling: effectcraft_raster::Sampling,
-    /// Dissolve noise seed.
-    pub seed: u32,
-}
-
-/// Hooks for accelerated compositors (`effectcraft-gpu`): the pieces of the CPU walk they reuse
-/// or fall back to. The CPU compositor itself is [`Renderer::comp_frame_cpu`].
-impl<'a> Renderer<'a> {
-    /// The project's colour pipeline.
-    pub fn pipe(&self) -> color::Pipe {
-        self.pipe
-    }
-
-    /// Nesting depth (0 = the top-level comp).
-    pub fn depth(&self) -> usize {
-        self.depth
-    }
-
-    /// The auxiliary 3D channels of comp `comp_id` at comp time `t` (depth, layer IDs, normals,
-    /// UVs, Cryptomatte; see `three_d::compose::aux_pass`), at the renderer's output scale.
-    pub fn comp_aux(&self, comp_id: ItemId, t: Tick) -> Option<effectcraft_raster::AuxChannels> {
-        let ctx = self.eval_ctx(comp_id, t)?;
-        Some(three_d::compose::aux_pass(self, &ctx))
-    }
-
-    /// The auxiliary channels effects on `layer` read ([`EffectHost::aux`]): its multi-layer
-    /// OpenEXR footage's at the layer's source time (Time Remap included), or a precomp's
-    /// generated 3D channels at its nested time. `None` for other layers.
-    pub fn layer_aux(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Arc<effectcraft_raster::AuxChannels>> {
-        match &layer.source {
-            LayerSource::Footage { item } => {
-                let ItemKind::Footage(f) = &self.project.item(*item)?.kind else { return None };
-                let a = self.footage.aux(*item, f, ctx.source_time(layer))?;
-                // Aux pixels per layer pixel (the layer is the footage at its nominal size). The
-                // planes are only copied when that changes the scale.
-                let scale = a.width as f64 / f.width as f64;
-                if f.width > 0 && a.width > 0 && a.scale != scale {
-                    let mut a = (*a).clone();
-                    a.scale = scale;
-                    return Some(Arc::new(a));
-                }
-                Some(a)
-            }
-            LayerSource::Comp { item } => {
-                if self.depth > MAX_FX_DEPTH || self.project.comp_contains(*item, ctx.comp_id) {
-                    return None;
-                }
-                self.nested().comp_aux(*item, ctx.nested_time(layer)).map(Arc::new)
-            }
-            _ => None,
-        }
-    }
-
-    /// Evaluation context of comp `comp_id` at comp time `t`.
-    pub fn eval_ctx(&self, comp_id: ItemId, t: Tick) -> Option<EvalCtx<'a>> {
-        Some(self.ctx(comp_id, self.project.comp(comp_id)?, t))
-    }
-
-    /// The layers drawn at the context time, bottom to top (solo, guides and visibility
-    /// applied).
-    pub fn visible_layers(&self, ctx: &EvalCtx<'a>) -> Vec<&'a Layer> {
-        let (comp, t) = (ctx.comp, ctx.time);
-        let any_solo = comp.any_solo();
-        comp.layers
-            .iter()
-            .rev()
-            .filter(|l| l.is_active_at(t) && l.has_video() && !l.environment && (!any_solo || l.switches.solo) && (self.opts.guides || !l.switches.guide))
-            .collect()
-    }
-
-    /// Draw a run of consecutive 3D layers into `canvas` (CPU).
-    pub fn draw_3d_run(&self, ctx: &EvalCtx<'a>, run: &[&Layer], canvas: &mut Image) {
-        three_d::compose::draw_run(self, ctx, run, canvas);
-    }
-
-    /// A run of consecutive 3D layers prepared for an accelerator (planes, lights, shadow
-    /// casters; see [`three_d::Run3d`]) at output size `out`. `None` = draw it with
-    /// [`Self::draw_3d_run`] (adjustment or wireframe layers in the run, Advanced 3D).
-    pub fn prepare_3d_run(&self, ctx: &EvalCtx<'a>, run: &[&Layer], out: (u32, u32)) -> Option<three_d::Run3d> {
-        three_d::compose::gpu_run(self, ctx, run, out)
-    }
-
-    /// A run of consecutive 3D layers of an Advanced 3D comp prepared for an accelerator's
-    /// compositor ([`three_d::adv::Prepared`]): rendered as one scene and composited (Normal,
-    /// premultiplied over) onto the canvas. `None` = not an Advanced 3D comp, or a layer needs the
-    /// 2D compositing path (blend mode, track matte, Preserve Transparency): draw it with
-    /// [`Self::draw_3d_run`].
-    pub fn prepare_adv_run<'p>(&'p self, ctx: &'p EvalCtx<'a>, run: &'p [&'p Layer], out: (u32, u32)) -> Option<three_d::adv::Prepared<'p, 'a>> {
-        three_d::adv::prepare_run(self, ctx, run, out)
-    }
-
-    /// A run of consecutive 3D layers of an Advanced 3D comp whose layers need the 2D
-    /// compositing path (blend mode, track matte, Preserve Transparency), split for an
-    /// accelerator's compositor ([`three_d::adv::SplitRun`]). `None` = [`Self::prepare_adv_run`]
-    /// covers it, or it isn't an Advanced 3D run.
-    pub fn split_adv_run<'p>(&'p self, ctx: &'p EvalCtx<'a>, run: &'p [&'p Layer], out: (u32, u32)) -> Option<three_d::adv::SplitRun<'p, 'a>> {
-        three_d::adv::split_run(self, ctx, run, out)
-    }
-
-    /// Whether the comp's 3D layers draw with the Advanced 3D renderer.
-    pub fn is_adv3d(&self, ctx: &EvalCtx) -> bool {
-        three_d::adv::active(self, ctx)
-    }
-
-    /// An Environment Light Background layer ready to draw on an accelerator
-    /// ([`three_d::SkyDraw`]; the CPU draws it in `draw_3d_run`). `None` = nothing to draw.
-    pub fn sky_draw(&self, ctx: &EvalCtx, layer: &Layer) -> Option<three_d::SkyDraw> {
-        three_d::compose::sky_draw(self, ctx, layer)
-    }
-
-    /// The pixels a Wireframe-quality layer sets (white, opaque) on a `size` canvas: its
-    /// bounds' outline, one pixel wide. Empty when the layer has no bounds.
-    pub fn wireframe_pixels(&self, ctx: &EvalCtx, layer: &Layer, size: (u32, u32)) -> Vec<(u32, u32)> {
-        let Some(b) = content_bounds(ctx, layer) else { return vec![] };
-        let s = self.opts.scale;
-        let (l2c, _) = ctx.layer_to_comp(layer);
-        let m = Mat3::scale(vec2(s, s)) * self.outer.map_or(l2c, |o| o * l2c);
-        let c = [(b[0], b[1]), (b[2], b[1]), (b[2], b[3]), (b[0], b[3])].map(|(x, y)| m.apply(vec2(x, y)));
-        let (w, h) = (size.0 as i64, size.1 as i64);
-        let mut out = vec![];
-        for i in 0..4 {
-            let (p, q) = (c[i], c[(i + 1) % 4]);
-            let n = ((q.x - p.x).abs().max((q.y - p.y).abs()) * 2.0).ceil().clamp(1.0, 1.0e5) as usize;
-            for j in 0..=n {
-                let t = j as f64 / n as f64;
-                let (x, y) = ((p.x + (q.x - p.x) * t).floor() as i64, (p.y + (q.y - p.y) * t).floor() as i64);
-                if x >= 0 && y >= 0 && x < w && y < h {
-                    out.push((x as u32, y as u32));
-                }
-            }
-        }
-        out
-    }
-
-    /// Run the layer's effect stack on `target` (an accelerator's resident image): GPU-capable
-    /// runs through [`FxTarget::gpu`], the others through [`FxTarget::cpu`], with the CPU's
-    /// parameters and environment. `adjustment`: the stack runs on the comp below (adjustment
-    /// layers).
-    pub fn run_effects_on(&self, ctx: &EvalCtx, layer: &Layer, adjustment: bool, target: &mut dyn FxTarget) {
-        // `target` is used as it is: the comp below for adjustment layers (the callers).
-        self.run_effect_stack(ctx, layer, adjustment, usize::MAX, None, [0.0; 2], target);
-    }
-
-    /// [`Renderer::run_effects_on`] for a (non-adjustment) layer's own pixels: `target` holds
-    /// them in effect space (as [`Renderer::layer_input`] hands them out) and the result stays
-    /// there. Returns the effect-space origin in layer coordinates (rebase by its negation).
-    pub fn run_layer_effects_on(&self, ctx: &EvalCtx, layer: &Layer, target: &mut dyn FxTarget) -> [f64; 2] {
-        let origin = ctx.effect_bounds(layer).1;
-        self.run_effect_stack(ctx, layer, false, usize::MAX, None, origin, target);
-        origin
-    }
-
-    /// An adjustment layer's footprint (its source with masks applied, layer space): where
-    /// its effects show. `None` = the layer changes nothing.
-    pub fn adjustment_footprint(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Arc<Buf>> {
-        // Cached, so an accelerator sees the same buffer (and uploads it once) every frame.
-        let key = self.cache.and_then(|_| cache::footprint_key(ctx, layer, self.raster_scale(ctx, layer), self.opts.draft, self.mb_on(ctx, layer)));
-        if let (Some(c), Some(k)) = (self.cache, key)
-            && let Some(b) = c.get(k)
-        {
-            return Some(b);
-        }
-        let mut foot = self.source(ctx, layer)?;
-        let _ = masks::apply(ctx, layer, &mut foot, self.mask_blur(ctx, layer));
-        let foot = Arc::new(foot);
-        // The buffer the cache keeps (another worker's, if it kept one first).
-        let foot = match (self.cache_to_keep(), key) {
-            (Some(c), Some(k)) => c.insert(k, foot),
-            _ => foot,
-        };
-        Some(foot)
-    }
-
-    /// Draw one 2D layer into `canvas` on the CPU (any kind: adjustment, wireframe, styled…).
-    pub fn draw_layer_cpu(&self, ctx: &EvalCtx, layer: &Layer, canvas: &mut Image) {
-        self.draw_layer(ctx, layer, canvas, false);
-    }
-
-    /// Draw a collapsed precomp layer into `canvas` on the CPU.
-    pub fn draw_collapsed_cpu(&self, ctx: &EvalCtx<'a>, layer: &Layer, item: ItemId, canvas: &mut Image) {
-        self.draw_collapsed(ctx, layer, item, canvas, false);
-    }
-
-    /// The layer's finished buffers (styles included) in the blending space.
-    pub fn styled_layer(&self, ctx: &EvalCtx, layer: &Layer) -> Option<StyledLayer> {
-        let mut timing = self.profile.map(|_| LayerTiming { depth: self.depth, layer: layer.name.clone(), ..Default::default() });
-        let t0 = web_time::Instant::now();
-        let st = self.styled(ctx, layer, timing.as_mut()).map(|st| self.styled_to_blend(st));
-        if let (Some(prof), Some(mut timing)) = (self.profile, timing) {
-            timing.process_ms = t0.elapsed().as_secs_f64() * 1e3;
-            if let Ok(mut v) = prof.lock() {
-                v.push(timing);
-            }
-        }
-        st
-    }
-
-    /// Opacity the layer composites with (its Opacity × collapsed precomps' opacity).
-    pub fn layer_opacity(&self, ctx: &EvalCtx, layer: &Layer) -> f32 {
-        ctx.opacity(layer) as f32 * self.opacity_mul
-    }
-
-    /// The layer's track matte layer and kind, if it has a valid one.
-    pub fn track_matte<'c>(&self, ctx: &EvalCtx<'c>, layer: &Layer) -> Option<(&'c Layer, MatteKind)> {
-        layer.track_matte.and_then(|tm| ctx.comp.layer(tm.layer).filter(|m| m.id != layer.id).map(|m| (m, tm.kind)))
-    }
-}
-
-/// The layer's frame blending mode, if the comp's Enable Frame Blending switch is on.
-/// One field of an interlaced frame as a full frame: the field's lines (`parity` 0 = even /
-/// upper, 1 = odd / lower) kept, the other lines interpolated from their neighbours.
-pub fn field_frame(img: &Image, parity: usize) -> Image {
-    let (w, h) = (img.width as usize, img.height as usize);
-    let mut out = img.clone();
-    if h < 2 {
-        return out;
-    }
-    for y in 0..h {
-        if y % 2 == parity {
-            continue;
-        }
-        let above = y.checked_sub(1);
-        let below = (y + 1 < h).then_some(y + 1);
-        for x in 0..w {
-            let px = match (above, below) {
-                (Some(a), Some(b)) => {
-                    let (p, q) = (img.data[a * w + x], img.data[b * w + x]);
-                    [(p[0] + q[0]) * 0.5, (p[1] + q[1]) * 0.5, (p[2] + q[2]) * 0.5, (p[3] + q[3]) * 0.5]
-                }
-                (Some(a), None) => img.data[a * w + x],
-                (None, Some(b)) => img.data[b * w + x],
-                (None, None) => img.data[y * w + x],
-            };
-            out.data[y * w + x] = px;
-        }
-    }
-    out
-}
-
-/// Interpret Footage ▸ Invert Alpha and Interpret As Linear Light on decoded (premultiplied)
-/// pixels; linear light is encoded in `space` ([`color::Pipe::linear_footage_space`]).
-pub fn interpret_pixels(img: &Image, f: &Footage, space: effectcraft_color::ColorSpace) -> Image {
-    let linear = f.linear_light_applies();
-    if !f.invert_alpha && !linear {
-        return img.clone();
-    }
-    let mut out = img.clone();
-    for p in out.data.iter_mut() {
-        let a = p[3];
-        let mut c = if a > 1e-6 { [p[0] / a, p[1] / a, p[2] / a] } else { [0.0; 3] };
-        if linear {
-            // The file's values are linear light: encode them like the rest of the footage.
-            c = c.map(|v| space.encode(v));
-        }
-        let a = if f.invert_alpha { 1.0 - a } else { a };
-        *p = [c[0] * a, c[1] * a, c[2] * a, a];
-    }
-    out
-}
-
-fn frame_blend_mode(ctx: &EvalCtx, layer: &Layer) -> FrameBlend {
-    if ctx.comp.enable_frame_blending { layer.switches.frame_blend } else { FrameBlend::Off }
-}
-
-/// Position of source time `t` among frames at `rate`: the frame at or before `t` and the
-/// fraction (0..1) of the way to the next frame. Exact (integer tick arithmetic), so frames that
-/// line up exactly report a fraction of 0.
-pub fn frame_position(t: Tick, rate: FrameRate) -> (i64, f64) {
-    let num = t.0 as i128 * rate.num as i128;
-    let den = TICKS_PER_SECOND as i128 * rate.den as i128;
-    (num.div_euclid(den) as i64, num.rem_euclid(den) as f64 / den as f64)
-}
-
-/// Blend two neighbouring frames `w` of the way from `a` to `b`: a cross-fade (Frame Mix) or a
-/// motion-compensated interpolation (Pixel Motion).
-pub fn blend_frames(mode: FrameBlend, a: &Image, b: &Image, w: f32) -> Image {
-    match mode {
-        FrameBlend::PixelMotion => effectcraft_raster::flow::interpolate(a, b, w),
-        _ => effectcraft_raster::flow::mix(a, b, w),
-    }
-}
-
-/// Convenience: render one frame of a comp with no footage source.
-/// Adaptive motion-blur sample count for a layer whose corners travel `travel` output pixels
-/// during the shutter: one sample per pixel, clamped to Samples Per Frame … Adaptive Sample Limit.
-pub fn adaptive_samples(travel: f64, per_frame: u32, limit: u32) -> usize {
-    let lo = per_frame.clamp(2, 64) as f64;
-    let hi = (limit.clamp(16, 256) as f64).max(lo);
-    travel.ceil().clamp(lo, hi) as usize
-}
-
-/// A region of interest `[x, y, w, h]` lies within a `w`×`h` comp frame.
-pub fn roi_inside(r: [f64; 4], w: u32, h: u32) -> bool {
-    r[0] >= 0.0 && r[1] >= 0.0 && r[0] + r[2] <= w as f64 + 1e-6 && r[1] + r[3] <= h as f64 + 1e-6
-}
-
-/// The Extended Viewer's region of interest: the comp frame grown by `margin` × its size on every
-/// side (`margin` = 1 shows a pasteboard one comp wide around the frame), intersected with the
-/// `visible` comp-space rectangle `[x0, y0, x1, y1]` and snapped outward to whole 16 px steps from the frame edges
-/// so panning re-renders rarely. `None` when the visible area lies inside the frame.
-pub fn extended_region(w: u32, h: u32, visible: [f64; 4], margin: f64) -> Option<[f64; 4]> {
-    let (w, h) = (w as f64, h as f64);
-    let (mx, my) = (w * margin, h * margin);
-    let snap_lo = |v: f64| (v / 16.0).floor() * 16.0;
-    let snap_hi = |v: f64| (v / 16.0).ceil() * 16.0;
-    let x0 = snap_lo(visible[0].max(-mx)).min(0.0);
-    let y0 = snap_lo(visible[1].max(-my)).min(0.0);
-    let x1 = w + snap_hi(visible[2].min(w + mx) - w).max(0.0);
-    let y1 = h + snap_hi(visible[3].min(h + my) - h).max(0.0);
-    if x0 >= 0.0 && y0 >= 0.0 && x1 <= w && y1 <= h {
-        return None;
-    }
-    Some([x0, y0, x1 - x0, y1 - y0])
-}
-
-/// The size of a `width` x `height` comp frame rendered at `scale` (both compositors, and the
-/// frame size Composition Settings shows for a Resolution).
-pub fn frame_size(width: u32, height: u32, scale: f64) -> (u32, u32) {
-    (((width as f64 * scale).round() as u32).max(1), ((height as f64 * scale).round() as u32).max(1))
-}
-
-pub fn render_frame(project: &Project, comp: ItemId, t: Tick, scale: f64) -> Image {
-    Renderer::new(project, &NoFootage, RenderOpts { scale, ..Default::default() }).comp_frame(comp, t)
-}
-
 #[cfg(test)]
 mod tests;
-#[cfg(test)]
-mod tests_auto;
-#[cfg(test)]
-mod tests_remap;
-#[cfg(test)]
-mod tests_roi;
-#[cfg(test)]
-mod tests_styles;
-
-/// Layer-space bounds `[x0, y0, x1, y1]` of a layer's content at the context time (source size
-/// for solids/footage/precomps, glyph bounds for text, painted bounds for shapes). Used for viewer
-/// handles and hit testing.
-pub fn content_bounds(ctx: &EvalCtx, layer: &effectcraft_project::Layer) -> Option<[f64; 4]> {
-    match &layer.source {
-        LayerSource::Text => {
-            let glyphs = text::glyph_paths(ctx, layer);
-            let paths: Vec<_> = glyphs.into_iter().map(|g| g.0).collect();
-            effectcraft_path::bounds(&paths).map(|r| [r.x0, r.y0, r.x1, r.y1])
-        }
-        LayerSource::Shape => layer.props.sub("contents").and_then(|c| shapes::content_bounds(ctx, layer, c)).map(|r| [r.x0, r.y0, r.x1, r.y1]),
-        LayerSource::Camera | LayerSource::Light { .. } => None,
-        _ => {
-            let (w, h) = source_size(ctx.project, layer);
-            (w > 0 && h > 0).then_some([0.0, 0.0, w as f64, h as f64])
-        }
-    }
-}
-
-/// A mask/shape path as a kurbo path (for drawing overlays).
-pub fn kurbo_path(sp: &effectcraft_keyframe::ShapePath) -> kurbo::BezPath {
-    effectcraft_path::to_kurbo(sp)
-}
-#[cfg(test)]
-mod tests_audio_fx;
-#[cfg(test)]
-mod tests_aux;
-#[cfg(test)]
-mod tests_collapse;
-#[cfg(test)]
-mod tests_color;
-#[cfg(test)]
-mod tests_footage_size;
-#[cfg(test)]
-mod tests_frame_blend;
-#[cfg(test)]
-mod tests_guides;
-#[cfg(test)]
-mod tests_mask_blur;
-#[cfg(test)]
-mod tests_mask_expansion;
-#[cfg(test)]
-mod tests_motion_tile;
-#[cfg(test)]
-mod tests_nested;
-#[cfg(test)]
-mod tests_paint;
-#[cfg(test)]
-mod tests_time;
diff --git a/crates/render/src/opts.rs b/crates/render/src/opts.rs
new file mode 100644
index 000000000..c6175bf39
--- /dev/null
+++ b/crates/render/src/opts.rs
@@ -0,0 +1,97 @@
+use super::accel::Backend;
+use super::{Comp, EvalCtx, ItemId, Layer, Mat4, Tick, three_d};
+
+#[derive(Clone, Copy, Debug, serde::Serialize, serde::Deserialize)]
+#[serde(default, rename_all = "camelCase")]
+pub struct RenderOpts {
+    /// Output scale relative to comp pixels (1 = Full, 0.5 = Half…).
+    pub scale: f64,
+    pub motion_blur: bool,
+    /// Render guide layers (viewer only). Only the top-level comp's own guide layers: nested
+    /// comps (precomps, collapsed precomps, comps read by effects) never draw theirs, as in
+    /// After Effects (see `Renderer::nested_opts`).
+    pub guides: bool,
+    /// Draft quality: fewer motion-blur samples, bilinear only.
+    pub draft: bool,
+    /// 3D view camera override (viewer Front/Top/Custom views); None = the comp's active camera.
+    pub view: Option<three_d::CameraState>,
+    /// CPU or GPU compositor (the GPU needs [`Renderer::accel`]).
+    pub backend: Backend,
+    /// Region of interest `[x, y, w, h]` in comp pixels (viewer only): the top-level frame covers
+    /// just this rectangle, and only its pixels are composited.
+    pub roi: Option<[f64; 4]>,
+    /// Which proxies stand in for footage and compositions (Render Settings ▸ Proxy Use).
+    pub proxy: effectcraft_project::render_queue::ProxyUse,
+    /// Switches Affect Nested Comps (Settings ▸ General): a precomp layer's Quality and Motion
+    /// Blur switches also limit the layers of the nested comp (Draft/Wireframe or motion blur off
+    /// propagate down; they never raise a nested layer's own setting).
+    pub nested_switches: bool,
+    /// Realtime Shadows in Draft (Settings ▸ 3D): draft renders (`draft`) still cast shadows.
+    pub draft_shadows: bool,
+}
+
+impl RenderOpts {
+    /// Whether 3D layers cast shadows in this render.
+    pub fn shadows(&self) -> bool {
+        !self.draft || self.draft_shadows
+    }
+}
+
+impl Default for RenderOpts {
+    fn default() -> Self {
+        RenderOpts {
+            scale: 1.0,
+            motion_blur: true,
+            guides: false,
+            draft: false,
+            view: None,
+            roi: None,
+            backend: Backend::Cpu,
+            nested_switches: true,
+            draft_shadows: true,
+            proxy: effectcraft_project::render_queue::ProxyUse::CurrentSettings,
+        }
+    }
+}
+
+/// One collapsed precomp layer a nested comp is drawn through.
+#[derive(Clone, Copy)]
+pub(crate) struct Through<'a> {
+    pub(crate) comp_id: ItemId,
+    pub(crate) comp: &'a Comp,
+    /// The containing comp's time at this frame.
+    pub(crate) time: Tick,
+    pub(crate) layer: &'a Layer,
+    /// The precomp layer is motion blurred: its own motion blurs the nested layers.
+    pub(crate) blur: bool,
+}
+
+/// Collapsed precomps within collapsed precomps that motion blur follows (more than
+/// [`Renderer::collapsed`]'s nesting limit).
+pub(crate) const MAX_THROUGH: usize = 16;
+
+/// How a collapsed precomp's 3D layers are placed in the parent (see `Renderer::collapse_into`).
+#[derive(Clone, Copy)]
+pub(crate) struct Collapse3d<'a> {
+    /// Nested comp world → parent world (the precomp layer's world transform).
+    pub world: Mat4,
+    /// The parent's camera.
+    pub cam: three_d::CameraState,
+    /// The outermost comp's context (its lights light the nested layers).
+    pub parent: EvalCtx<'a>,
+}
+
+/// Time spent on one layer of one frame (milliseconds).
+#[derive(Clone, Debug, Default)]
+pub struct LayerTiming {
+    pub depth: usize,
+    pub layer: String,
+    /// Source + masks + effects (cache lookup only, on a hit).
+    pub process_ms: f64,
+    /// Per effect: (effect id, ms). Empty on a cache hit.
+    pub effects: Vec<(String, f64)>,
+    /// Transform + matte + blend.
+    pub composite_ms: f64,
+    /// The processed buffer came from the layer cache.
+    pub cached: bool,
+}
diff --git a/crates/render/src/pipeline.rs b/crates/render/src/pipeline.rs
new file mode 100644
index 000000000..bc1879369
--- /dev/null
+++ b/crates/render/src/pipeline.rs
@@ -0,0 +1,885 @@
+use super::accel::{Accelerator, Backend, CpuFx, FxStep, FxTarget};
+use super::footage::{FootageSource, is_vector_footage};
+use super::frames::{blend_frames, content_bounds, field_frame, frame_blend_mode, frame_position, frame_size, interpret_pixels, roi_inside};
+use super::fx_host::{FxHost, essential_overrides};
+use super::opts::{Collapse3d, LayerTiming, MAX_THROUGH, RenderOpts, Through};
+use super::{
+    Arc, AutoKey, AutoPick, BlendMode, Buf, Comp, EffectCtx, EffectEnv, EvalCtx, Footage, FootageKind, FrameBlend, FrameRate, GroupKind, Image, ItemId,
+    ItemKind, Layer, LayerCache, LayerSource, Params, Project, Quality, Region, Renderer, Tick, cache, color, masks, shapes, styles, text, three_d, vec2,
+};
+
+/// Coordinate space and stack range shared by CPU and accelerated effect evaluation.
+#[derive(Clone, Copy)]
+pub(crate) struct EffectStack {
+    pub adjustment: bool,
+    pub limit: usize,
+    pub origin: [f64; 2],
+}
+
+impl<'a> Renderer<'a> {
+    pub fn new(project: &'a Project, footage: &'a dyn FootageSource, opts: RenderOpts) -> Renderer<'a> {
+        Renderer {
+            project,
+            footage,
+            expr: None,
+            opts,
+            cache: None,
+            profile: None,
+            accel: None,
+            depth: 0,
+            pipe: color::Pipe::of(&project.settings),
+            outer: None,
+            opacity_mul: 1.0,
+            collapse3d: None,
+            inherited: None,
+            defer_dof: false,
+            top: true,
+            through: [None; MAX_THROUGH],
+            through_lost: false,
+        }
+    }
+
+    /// The layer cache to keep this render's buffers in: none once its footage reads were
+    /// called off, as they may have come back empty ([`FootageSource::called_off`], #329).
+    pub(crate) fn cache_to_keep(&self) -> Option<&'a LayerCache> {
+        self.cache.filter(|_| !self.footage.called_off())
+    }
+
+    /// A layer's Quality switch, limited by the precomp layers above it when
+    /// [`RenderOpts::nested_switches`] is on.
+    pub fn quality(&self, layer: &Layer) -> Quality {
+        let rank = |q: Quality| match q {
+            Quality::Best => 0,
+            Quality::Draft => 1,
+            Quality::Wireframe => 2,
+        };
+        match self.inherited {
+            Some((q, _)) if rank(q) > rank(layer.switches.quality) => q,
+            _ => layer.switches.quality,
+        }
+    }
+
+    /// A layer's Motion Blur switch, limited by the precomp layers above it.
+    pub(crate) fn layer_motion_blur(&self, layer: &Layer) -> bool {
+        layer.switches.motion_blur && self.inherited.is_none_or(|(_, mb)| mb)
+    }
+
+    /// The renderer for the nested comp of precomp layer `layer`: its switches pass down when
+    /// [`RenderOpts::nested_switches`] is on.
+    fn nested_through(&self, layer: &Layer) -> Renderer<'a> {
+        let mut sub = self.nested();
+        if self.opts.nested_switches {
+            sub.inherited = Some((self.quality(layer), self.layer_motion_blur(layer)));
+        }
+        sub
+    }
+
+    /// The render options one level down (precomps, collapsed precomps, comps read by effects):
+    /// guide layers render only in their own comp, never when it is nested.
+    fn nested_opts(&self) -> RenderOpts {
+        RenderOpts { guides: false, ..self.opts }
+    }
+
+    /// A renderer for nested work (precomps, layers read by effects): one level deeper.
+    pub(crate) fn nested(&self) -> Renderer<'a> {
+        Renderer {
+            opts: self.nested_opts(),
+            depth: self.depth + 1,
+            outer: None,
+            opacity_mul: 1.0,
+            collapse3d: None,
+            defer_dof: false,
+            top: false,
+            through: [None; MAX_THROUGH],
+            through_lost: false,
+            ..*self
+        }
+    }
+
+    /// A precomp layer's nested comp for an accelerator to render resident (no CPU render and
+    /// upload of the nested frame): the renderer one level down, the comp, its time and the
+    /// buffer scale, exactly as [`Self::layer_source`]'s comp branch would render it. `None`
+    /// when that branch does more (composition proxy, Essential Properties overrides, frame
+    /// blending, recursion) or draws nothing (outside the nested comp's span): use the CPU path.
+    pub fn precomp_source(&self, ctx: &EvalCtx, layer: &Layer) -> Option<(Renderer<'a>, ItemId, Tick, f64)> {
+        let LayerSource::Comp { item } = layer.source else { return None };
+        if layer.switches.adjustment || self.project.comp_contains(item, ctx.comp_id) {
+            return None;
+        }
+        let nc = self.project.comp(item)?;
+        let lt = ctx.nested_time(layer);
+        if self.content_times(ctx, layer).is_some() {
+            return None;
+        }
+        if !nc.covers(lt) || self.proxy_for(item).is_some() || !essential_overrides(ctx, layer).is_empty() || frame_blend_mode(ctx, layer) != FrameBlend::Off {
+            return None;
+        }
+        let s = self.opts.scale;
+        let bs = if s < 1.0 && nc.preserve_resolution { 1.0 } else { s };
+        let base = self.nested_through(layer);
+        Some((Renderer { opts: RenderOpts { scale: bs, ..base.opts }, ..base }, item, lt, bs))
+    }
+
+    /// The nested comp of a precomp layer whose transformations collapse into this comp: the
+    /// Collapse Transformations switch is on and the layer has no masks, effects or layer
+    /// styles (those force a flattened render of the precomp, as in After Effects).
+    pub fn collapsed(&self, ctx: &EvalCtx, layer: &Layer) -> Option<ItemId> {
+        if !layer.switches.collapse || layer.switches.adjustment || self.depth > 12 {
+            return None;
+        }
+        let LayerSource::Comp { item } = &layer.source else { return None };
+        if self.project.comp_contains(*item, ctx.comp_id) || self.project.comp(*item).is_none() {
+            return None;
+        }
+        if layer.masks().is_some_and(|m| !m.children.is_empty()) {
+            return None;
+        }
+        if layer.switches.effects && layer.effects().is_some_and(|fx| fx.groups().any(|g| g.enabled)) {
+            return None;
+        }
+        if styles::active(ctx, layer) {
+            return None;
+        }
+        // Instance overrides (Essential Properties) need the nested comp rendered on its own.
+        if !effectcraft_project::essential::overridden(layer).is_empty() {
+            return None;
+        }
+        Some(*item)
+    }
+
+    /// A renderer and context that draw a collapsed precomp's layers straight into this comp:
+    /// their transforms are concatenated with the precomp layer's (one resample, no
+    /// rasterisation at the precomp's bounds), their opacity multiplied by `opacity`, and their
+    /// 3D layers use this comp's camera and lights.
+    pub fn collapse_into(&self, ctx: &EvalCtx<'a>, layer: &'a Layer, item: ItemId, opacity: f32) -> Option<(Renderer<'a>, EvalCtx<'a>)> {
+        let nc = self.project.comp(item)?;
+        let t = ctx.nested_time(layer);
+        if !nc.covers(t) {
+            return None;
+        }
+        let nctx = EvalCtx { comp_id: item, comp: nc, time: t, ..*ctx };
+        let (l2c, _) = ctx.layer_to_comp(layer);
+        let outer = Some(self.outer.map_or(l2c, |o| o * l2c));
+        let world = ctx.world_matrix(layer);
+        let c3 = Collapse3d {
+            world: self.collapse3d.map_or(world, |c| c.world * world),
+            cam: three_d::compose::camera_for(self, ctx),
+            parent: self.collapse3d.map_or(*ctx, |c| c.parent),
+        };
+        // Motion blur follows the precomp layer's own motion too.
+        let link = Through { comp_id: ctx.comp_id, comp: ctx.comp, time: ctx.time, layer, blur: self.mb_on(ctx, layer) };
+        let mut through = self.through;
+        let slot = through.iter_mut().find(|t| t.is_none());
+        let through_lost = self.through_lost || slot.is_none();
+        if let Some(slot) = slot {
+            *slot = Some(link);
+        }
+        Some((
+            Renderer { opts: self.nested_opts(), depth: self.depth + 1, outer, opacity_mul: opacity, collapse3d: Some(c3), through, through_lost, ..*self },
+            nctx,
+        ))
+    }
+
+    pub(crate) fn opacity_mul(&self) -> f32 {
+        self.opacity_mul
+    }
+
+    /// Draw a collapsed 2D precomp layer: nested layers blend straight into `canvas` with their
+    /// own modes (Normal precomp, no matte); otherwise they are drawn into an isolated buffer
+    /// that then takes the precomp layer's track matte, Preserve Transparency and blend mode.
+    /// Returns the region left to re-quantise (nested layers drawn straight into `canvas`
+    /// quantise their own footprints).
+    pub(crate) fn draw_collapsed(&self, ctx: &EvalCtx<'a>, layer: &Layer, item: ItemId, canvas: &mut Image, blank: bool) -> Region {
+        let opacity = ctx.opacity(layer) as f32 * self.opacity_mul;
+        if opacity <= 0.0 {
+            return Region::Empty;
+        }
+        let matte = layer.track_matte.is_some_and(|tm| tm.layer != layer.id && ctx.comp.layer(tm.layer).is_some());
+        if layer.blend_mode == BlendMode::Normal && !matte && !layer.preserve_transparency {
+            if let Some((sub, nctx)) = self.collapse_into(ctx, layer, item, opacity) {
+                sub.draw_comp(&nctx, canvas, blank);
+            }
+            return Region::Empty;
+        }
+        let Some((sub, nctx)) = self.collapse_into(ctx, layer, item, 1.0) else { return Region::Empty };
+        let mut iso = Image::new(canvas.width, canvas.height);
+        sub.draw_comp(&nctx, &mut iso, true);
+        self.composite_iso(ctx, layer, iso, canvas, opacity);
+        Region::Full
+    }
+
+    /// Whether `layer`'s processed buffer (source → masks → effects) is cached and the same as
+    /// one frame earlier: drawing it from the layer cache (an accelerator uploads it once) beats
+    /// re-running its effects every frame.
+    pub fn layer_is_static(&self, ctx: &EvalCtx, layer: &Layer) -> bool {
+        if self.cache.is_none() {
+            return false;
+        }
+        let (scale, draft, blur) = (self.raster_scale(ctx, layer), self.opts.draft, self.mb_on(ctx, layer));
+        let prev = ctx.time - ctx.comp.frame_rate.frame_duration();
+        let now = cache::layer_key(ctx, layer, scale, draft, blur);
+        now.is_some() && now == cache::layer_key(&ctx.at(prev), layer, scale, draft, blur)
+    }
+
+    /// Rasterisation scale of a layer's source: the output scale, or — for text and shape layers,
+    /// which are always continuously rasterised (#390, #751), and Continuously Rasterize vector
+    /// footage — the output scale times the layer's on-screen scale (quarter-octave steps, rounded
+    /// up, so vector content is drawn at its final size and stays sharp when scaled up).
+    pub fn raster_scale(&self, ctx: &EvalCtx, layer: &Layer) -> f64 {
+        let s = self.opts.scale;
+        let continuous = match layer.source {
+            LayerSource::Text | LayerSource::Shape => true,
+            LayerSource::Footage { item } => {
+                layer.switches.collapse && matches!(self.project.item(item).map(|i| &i.kind), Some(ItemKind::Footage(f)) if is_vector_footage(f))
+            }
+            _ => false,
+        };
+        if !continuous {
+            return s;
+        }
+        let (l2c, _) = ctx.layer_to_comp(layer);
+        let m = self.outer.map_or(l2c, |o| o * l2c);
+        let a = layer.transform().map(|tr| ctx.v3(layer, tr, "anchor", [0.0; 3])).unwrap_or([0.0; 3]);
+        let p0 = m.apply(vec2(a[0], a[1]));
+        let px = m.apply(vec2(a[0] + 1.0, a[1]));
+        let py = m.apply(vec2(a[0], a[1] + 1.0));
+        let k = ((px.x - p0.x).hypot(px.y - p0.y)).max((py.x - p0.x).hypot(py.y - p0.y));
+        if !k.is_finite() || k <= 1e-6 {
+            return s;
+        }
+        // The step is rounded up past rounding noise only: an unscaled layer whose position isn't
+        // a whole number maps the unit vectors to lengths a hair over 1, which must stay 1 (#390:
+        // rounded up to 2^¼, unscaled text was drawn larger and resampled, softer).
+        let mut k = 2f64.powf((k.log2() * 4.0 - 1e-6).ceil() / 4.0).clamp(1.0 / 16.0, 64.0);
+        // Keep the buffer within about 16 million pixels.
+        if let Some(b) = content_bounds(ctx, layer) {
+            let area = ((b[2] - b[0]) * (b[3] - b[1])).max(1.0) * s * s;
+            k = k.min((16.0e6 / area).sqrt().max(1.0));
+        }
+        s * k
+    }
+
+    /// Draw a Wireframe-quality layer: its bounds as a one-pixel outline.
+    pub(crate) fn draw_wireframe(&self, ctx: &EvalCtx, layer: &Layer, canvas: &mut Image) {
+        for (x, y) in self.wireframe_pixels(ctx, layer, (canvas.width, canvas.height)) {
+            canvas.set(x, y, [1.0, 1.0, 1.0, 1.0]);
+        }
+    }
+
+    pub(crate) fn ctx(&self, comp_id: ItemId, comp: &'a Comp, t: Tick) -> EvalCtx<'a> {
+        EvalCtx { project: self.project, comp_id, comp, time: t, expr: self.expr, footage: Some(self.footage) }
+    }
+
+    /// This renderer with another accelerator (or none): the passes of
+    /// [`passes::in_passes`] render with the accelerator, its CPU fallback without.
+    pub fn with_accel(&self, accel: Option<&'a dyn Accelerator>) -> Renderer<'a> {
+        Renderer { accel, ..*self }
+    }
+
+    /// The accelerator to use for this render, if any (see [`Backend`]).
+    pub fn active_accel(&self) -> Option<&'a dyn Accelerator> {
+        let a = self.accel?;
+        match self.opts.backend {
+            Backend::Cpu => None,
+            Backend::Gpu => Some(a),
+            Backend::Auto => self.project.settings.gpu_acceleration.then_some(a),
+        }
+    }
+
+    /// Render a composition at comp time `t` (transparent background, comp size × scale).
+    /// Top-level frames go to the GPU when [`Self::active_accel`] is set and handles them.
+    pub fn comp_frame(&self, comp_id: ItemId, t: Tick) -> Image {
+        // Classic 3D runs composite on the GPU too (M12.7), so Auto sends 3D comps there as well;
+        // Auto renders each comp on whichever compositor measured faster ([`AutoPick`]).
+        if self.depth == 0
+            && let Some(a) = self.active_accel()
+        {
+            let auto = self.frame_auto(a, comp_id, false);
+            if auto.is_none_or(|(p, key)| p.choose(key)) {
+                let t0 = web_time::Instant::now();
+                if let Some(img) = a.comp_frame(self, comp_id, t) {
+                    if let Some((p, key)) = auto {
+                        p.record(key, true, t0.elapsed().as_secs_f64() * 1e3);
+                    }
+                    return img;
+                }
+                if let Some((p, key)) = auto {
+                    p.declined(key);
+                }
+            }
+            let t0 = web_time::Instant::now();
+            let img = self.comp_frame_cpu(comp_id, t);
+            if let Some((p, key)) = auto {
+                p.record(key, false, t0.elapsed().as_secs_f64() * 1e3);
+            }
+            return img;
+        }
+        self.comp_frame_cpu(comp_id, t)
+    }
+
+    /// The Auto timing history and key for a top-level frame of `comp` (`None` unless the
+    /// backend is [`Backend::Auto`] and the accelerator keeps history).
+    pub fn frame_auto(&self, a: &'a dyn Accelerator, comp: ItemId, display: bool) -> Option<(&'a AutoPick, AutoKey)> {
+        if self.opts.backend != Backend::Auto || self.opts.roi.is_some() {
+            return None;
+        }
+        Some((a.auto_pick()?, AutoKey::new(comp, self.opts.scale, display)))
+    }
+
+    /// [`Self::comp_frame`] on the CPU compositor only.
+    pub fn comp_frame_cpu(&self, comp_id: ItemId, t: Tick) -> Image {
+        let Some(comp) = self.project.comp(comp_id) else { return Image::new(1, 1) };
+        let s = self.opts.scale;
+        let (w, h) = frame_size(comp.width, comp.height, s);
+        // Region of interest on a comp with 3D layers: render the frame and crop it. A region
+        // reaching past the comp frame (the Extended Viewer) renders Classic 3D natively — the
+        // planes project through the offset camera — and Advanced 3D as the frame, padded.
+        if self.depth == 0
+            && let Some(r) = self.opts.roi
+            && comp.has_3d()
+            && (roi_inside(r, comp.width, comp.height) || comp.renderer == effectcraft_project::Renderer::Advanced3D)
+        {
+            let full = Renderer { opts: RenderOpts { roi: None, ..self.opts }, ..*self }.comp_frame(comp_id, t);
+            let (x0, y0) = ((r[0] * s).round() as i64, (r[1] * s).round() as i64);
+            let (rw, rh) = (((r[2] * s).round() as u32).max(1), ((r[3] * s).round() as u32).max(1));
+            let mut out = Image::new(rw, rh);
+            for y in 0..rh as i64 {
+                let sy = y + y0;
+                if sy < 0 || sy >= full.height as i64 {
+                    continue;
+                }
+                for x in 0..rw as i64 {
+                    let sx = x + x0;
+                    if sx >= 0 && sx < full.width as i64 {
+                        out.data[(y * rw as i64 + x) as usize] = full.data[(sy * full.width as i64 + sx) as usize];
+                    }
+                }
+            }
+            return out;
+        }
+        let (w, h) = match self.roi_offset() {
+            Some((_, _, rw, rh)) => (rw, rh),
+            None => (w, h),
+        };
+        let mut canvas = Image::new(w, h);
+        if self.depth > 16 {
+            return canvas;
+        }
+        let ctx = self.ctx(comp_id, comp, t);
+        self.draw_comp(&ctx, &mut canvas, true);
+        // The canvas is already quantised after every layer; only re-encoding changes it.
+        if let Some(c) = self.pipe.from_blend() {
+            color::convert(&mut canvas, &c);
+            self.pipe.quantize(&mut canvas);
+        }
+        // The top-level comp leaves the working space for the (sRGB) display / output.
+        if self.depth == 0
+            && let Some(c) = self.pipe.output()
+        {
+            color::convert(&mut canvas, &c);
+            self.pipe.quantize(&mut canvas);
+        }
+        if self.depth == 0
+            && let Some((lin, mode, enc)) = self.pipe.output_hdr()
+        {
+            color::output_hdr(&mut canvas, lin, mode, enc);
+            self.pipe.quantize(&mut canvas);
+        }
+        canvas
+    }
+
+    /// Draw a comp's layers (bottom to top) into `canvas` (blending space).
+    /// `blank`: the canvas is fully transparent (lets the first layer skip re-quantising).
+    fn draw_comp(&self, ctx: &EvalCtx<'a>, canvas: &mut Image, mut blank: bool) {
+        // Bottom-to-top, with runs of consecutive 3D layers depth-sorted (farthest first).
+        let visible = self.visible_layers(ctx);
+        let mut i = 0;
+        while i < visible.len() {
+            if visible[i].is_3d() {
+                let mut j = i;
+                while j < visible.len() && visible[j].is_3d() {
+                    j += 1;
+                }
+                three_d::compose::draw_run(self, ctx, &visible[i..j], canvas);
+                i = j;
+                self.pipe.quantize(canvas);
+                blank = false;
+            } else {
+                let changed = match self.collapsed(ctx, visible[i]) {
+                    Some(item) => self.draw_collapsed(ctx, visible[i], item, canvas, blank),
+                    None => self.draw_layer(ctx, visible[i], canvas, blank),
+                };
+                i += 1;
+                // 8/16 bpc: the comp is an integer buffer after every layer (only the pixels the
+                // layer touched need re-quantising).
+                self.pipe.quantize_region(canvas, changed);
+                blank = false;
+            }
+        }
+    }
+
+    /// Evaluate an effect instance's parameters.
+    fn effect_params(&self, ctx: &EvalCtx, layer: &Layer, g: &effectcraft_project::PropGroup) -> Params {
+        // Nested groups (Paint strokes, Puppet meshes and pins) are flattened too.
+        effectcraft_effects::flatten_params(g, &mut |pr| ctx.value(layer, pr))
+    }
+
+    pub(crate) fn apply_effects(&self, ctx: &EvalCtx, layer: &Layer, buf: Buf, adjustment: bool) -> Buf {
+        self.apply_effects_timed(ctx, layer, buf, adjustment, usize::MAX, None)
+    }
+
+    /// Run the first `limit` effects of the layer's stack (by position; disabled ones count) on
+    /// `buf` (layer space, or the comp below for an adjustment layer).
+    fn apply_effects_timed(&self, ctx: &EvalCtx, layer: &Layer, mut buf: Buf, adjustment: bool, limit: usize, timing: Option<&mut Vec<(String, f64)>>) -> Buf {
+        // The comp below an adjustment layer is not in its layer space: it stays as it is.
+        let origin = if adjustment { [0.0; 2] } else { ctx.effect_bounds(layer).1 };
+        buf.rebase(origin);
+        let mut out = self.effect_space_stack(ctx, layer, buf, EffectStack { adjustment, limit, origin }, timing);
+        out.rebase([-origin[0], -origin[1]]);
+        out
+    }
+
+    /// [`Renderer::apply_effects_timed`] on a buffer already in effect space (measured from
+    /// `origin`, in layer coordinates); the result stays in effect space.
+    fn effect_space_stack(&self, ctx: &EvalCtx, layer: &Layer, buf: Buf, stack: EffectStack, timing: Option<&mut Vec<(String, f64)>>) -> Buf {
+        let mut t = CpuFx { accel: self.active_accel(), levels: self.pipe.levels, buf: Some(buf) };
+        self.run_effect_stack(ctx, layer, stack, timing, &mut t);
+        t.buf.unwrap_or_else(|| Buf { img: Image::new(1, 1), offset: [0.0; 2], scale: self.opts.scale })
+    }
+
+    /// Run the layer's video effect stack on `target` (in effect space, measured from `origin`
+    /// in layer coordinates): runs of GPU-capable effects go to [`FxTarget::gpu`] (when an
+    /// accelerator is active and supports them), the rest to [`FxTarget::cpu`] one by one
+    /// (quantised to the bit depth after each).
+    pub(crate) fn run_effect_stack(
+        &self,
+        ctx: &EvalCtx,
+        layer: &Layer,
+        stack: EffectStack,
+        mut timing: Option<&mut Vec<(String, f64)>>,
+        target: &mut dyn FxTarget,
+    ) {
+        let EffectStack { adjustment, limit, origin } = stack;
+        if !layer.switches.effects {
+            return;
+        }
+        let Some(fx) = layer.effects() else { return };
+        let lt = layer.layer_time(ctx.time);
+        let layer_size = ctx.effect_bounds(layer).0;
+        // #659: an authored layer's buffer spans only its painted content while the stack works
+        // on the layer's whole region (`layer_size`): give the buffer the room a sized source
+        // already has, so tiling or displacement can place pixels outside the content instead
+        // of losing them at its edge. Only when something will actually run, and not for an
+        // adjustment layer, whose buffer is the comp below and already spans it.
+        if !adjustment
+            && fx.groups().any(|g| g.enabled && matches!(&g.kind, GroupKind::Effect { effect } if effectcraft_effects::find(effect).is_some_and(|s| !effectcraft_effects::audio_fx::is_audio_effect(s.id)))) {
+            target.cover(layer_size);
+        }
+        let mut mask_shapes = masks::shapes(ctx, layer);
+        if origin != [0.0; 2] {
+            for q in mask_shapes.iter_mut().flat_map(|m| m.points.iter_mut()) {
+                *q = [q[0] - origin[0], q[1] - origin[1]];
+            }
+        }
+        // Capture once, before preceding effects can expand or replace the input. An
+        // adjustment stack's original is the comp below, not its solid source.
+        let needs_original =
+            fx.groups().take(limit).any(|g| g.enabled && matches!(&g.kind, GroupKind::Effect { effect } if effect == "ec.channel.cccomposite"));
+        let mut original = None;
+        if needs_original {
+            target.cpu(&mut |buf| {
+                original = Some(buf.clone());
+                buf
+            });
+        }
+        let host = FxHost { r: self, ctx, layer, origin, index: 0, original: original.as_ref() };
+        let env = EffectEnv {
+            masks: &mask_shapes,
+            host: Some(&host),
+            comp_time: ctx.time.seconds(),
+            frame_rate: ctx.comp.frame_rate.as_f64(),
+            effect_index: 0,
+            working_space: self.pipe.space,
+            working_linear: self.pipe.linear,
+            float_depth: self.pipe.levels.is_none(),
+            shutter: self.mb_on(ctx, layer).then_some((ctx.comp.shutter_angle, ctx.comp.shutter_phase, ctx.comp.motion_blur_samples)),
+        };
+        // Video effects in stack order (index, group, spec); disabled and audio effects skipped.
+        let stack: Vec<(usize, &effectcraft_project::PropGroup, &'static effectcraft_effects::EffectSpec)> = fx
+            .groups()
+            .enumerate()
+            .take_while(|(i, _)| *i < limit)
+            .filter(|(_, g)| g.enabled)
+            .filter_map(|(i, g)| match &g.kind {
+                GroupKind::Effect { effect } => effectcraft_effects::find(effect).map(|s| (i, g, s)),
+                _ => None,
+            })
+            .filter(|(_, _, s)| !effectcraft_effects::audio_fx::is_audio_effect(s.id))
+            .collect();
+        let accel = self.active_accel();
+        let mut k = 0;
+        while k < stack.len() {
+            let (i, g, spec) = stack[k];
+            // A run of GPU effects goes to the accelerator in one go.
+            if let Some(a) = accel
+                && spec.gpu
+                && a.supports_effect(spec.id)
+            {
+                let run: Vec<_> = stack[k..].iter().take_while(|(_, _, s)| s.gpu && a.supports_effect(s.id)).collect();
+                let params: Vec<Params> = run.iter().map(|(_, g, _)| self.effect_params(ctx, layer, g)).collect();
+                let hosts: Vec<_> = run.iter().map(|(i, _, _)| FxHost { index: *i, ..host }).collect();
+                let steps: Vec<FxStep> = run
+                    .iter()
+                    .zip(&params)
+                    .zip(&hosts)
+                    .map(|(((i, g, s), params), host)| FxStep {
+                        spec: s,
+                        ctx: EffectCtx {
+                            params,
+                            time: lt.seconds(),
+                            layer_size,
+                            seed: g.uid as u32,
+                            adjustment,
+                            env: EffectEnv { host: Some(host), effect_index: *i, ..env },
+                        },
+                    })
+                    .collect();
+                let t0 = web_time::Instant::now();
+                if target.gpu(&steps) {
+                    if let Some(v) = timing.as_deref_mut() {
+                        let ms = t0.elapsed().as_secs_f64() * 1e3 / run.len() as f64;
+                        v.extend(run.iter().map(|(_, _, s)| (format!("{} (gpu)", s.id), ms)));
+                    }
+                    k += run.len();
+                    continue;
+                }
+            }
+            k += 1;
+            let params = self.effect_params(ctx, layer, g);
+            let host = FxHost { index: i, ..host };
+            let env = EffectEnv { host: Some(&host), effect_index: i, ..env };
+            let ectx = EffectCtx { params: &params, time: lt.seconds(), layer_size, seed: g.uid as u32, adjustment, env };
+            let t0 = web_time::Instant::now();
+            target.cpu(&mut |buf| {
+                let mut buf = effectcraft_effects::apply(spec, &ectx, buf);
+                // 8/16 bpc effects write integer pixels.
+                self.pipe.quantize(&mut buf.img);
+                buf
+            });
+            if let Some(v) = timing.as_deref_mut() {
+                v.push((spec.id.to_string(), t0.elapsed().as_secs_f64() * 1e3));
+            }
+        }
+    }
+
+    /// Source pixels of a layer in layer space (before masks/effects).
+    pub(crate) fn source(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Buf> {
+        let s = self.opts.scale;
+        match &layer.source {
+            LayerSource::Solid { item } => {
+                let ItemKind::Solid(sol) = &self.project.item(*item)?.kind else { return None };
+                let w = ((sol.width as f64 * s).ceil() as u32).max(1);
+                let h = ((sol.height as f64 * s).ceil() as u32).max(1);
+                if layer.switches.adjustment {
+                    return Some(Buf { img: Image::filled(w, h, [1.0; 4]), offset: [0.0; 2], scale: s });
+                }
+                let mut c = sol.color;
+                if let Some(conv) = self.pipe.authored_in() {
+                    c = conv.apply(c);
+                }
+                let px = self.pipe.quantize_px([c[0], c[1], c[2], 1.0]);
+                Some(Buf { img: Image::filled(w, h, px), offset: [0.0; 2], scale: s })
+            }
+            LayerSource::Comp { item } => {
+                if self.project.comp_contains(*item, ctx.comp_id) {
+                    return None;
+                }
+                // A composition proxy (a rendered still or movie) stands in for the comp.
+                // Nothing before the nested comp starts or after it ends.
+                let lt = ctx.nested_time(layer);
+                if !self.project.comp(*item).is_some_and(|nc| nc.covers(lt)) {
+                    return None;
+                }
+                if let Some(pf) = self.proxy_for(*item)
+                    && let Some(nc) = self.project.comp(*item)
+                {
+                    let img = self.footage.frame_with(*item, pf, lt, None, self.pipe.float_encoding())?;
+                    return Some(self.footage_buf(&img, pf, nc.width, nc.height));
+                }
+                // Essential Properties overrides render the nested comp with this instance's
+                // values.
+                let ov = essential_overrides(ctx, layer);
+                let tmp = if ov.is_empty() { None } else { effectcraft_project::essential::with_overrides(self.project, *item, &ov) };
+                // Preserve resolution when nested: drawn at full size even when this comp renders
+                // smaller (the buffer's scale places it).
+                let full = s < 1.0 && self.project.comp(*item).is_some_and(|nc| nc.preserve_resolution);
+                let bs = if full { 1.0 } else { s };
+                let base = self.nested_through(layer);
+                let base = Renderer { opts: RenderOpts { scale: bs, ..base.opts }, ..base };
+                let sub = match &tmp {
+                    Some(p) => Renderer { project: p, ..base },
+                    None => base,
+                };
+                // Frame blending between the nested comp's frames (time-stretched/remapped).
+                let mode = frame_blend_mode(ctx, layer);
+                if mode != FrameBlend::Off
+                    && let Some(nc) = self.project.comp(*item)
+                {
+                    let (i, w) = frame_position(lt, nc.frame_rate);
+                    if w > 1e-6 {
+                        let a = sub.comp_frame(*item, nc.frame_rate.tick_of(i));
+                        let b = sub.comp_frame(*item, nc.frame_rate.tick_of(i + 1));
+                        return Some(Buf { img: blend_frames(mode, &a, &b, w as f32), offset: [0.0; 2], scale: bs });
+                    }
+                }
+                Some(Buf { img: sub.comp_frame(*item, lt), offset: [0.0; 2], scale: bs })
+            }
+            LayerSource::Footage { item } => {
+                let it = self.project.item(*item)?;
+                let ItemKind::Footage(f) = &it.kind else { return None };
+                if !f.has_video {
+                    return None;
+                }
+                // Continuously rasterised vector footage: drawn at the on-screen scale.
+                if layer.switches.collapse && is_vector_footage(f) {
+                    let k = self.raster_scale(ctx, layer);
+                    if let Some(img) = self.footage.vector_frame(*item, f, k) {
+                        let mut buf = Buf { img: (*img).clone(), offset: [0.0; 2], scale: k };
+                        if let Some(c) = self.pipe.media_in(f) {
+                            color::convert(&mut buf.img, &c);
+                        }
+                        return Some(buf);
+                    }
+                }
+                let lt = ctx.source_time(layer);
+                // The proxy is decoded instead, at its own size, and fills the footage's frame.
+                let proxy = self.proxy_for(*item);
+                let pf = proxy.unwrap_or(f);
+                let size = self.reduced_size(f.width, f.height).filter(|_| proxy.is_none());
+                let img = self.footage_frame(ctx, layer, *item, pf, lt, size)?;
+                Some(self.footage_buf(&img, pf, f.width, f.height))
+            }
+            LayerSource::Text => Some(self.authored(text::render(ctx, layer, self.raster_scale(ctx, layer)))),
+            LayerSource::Shape => layer.props.sub("contents").map(|c| self.authored(shapes::render(ctx, layer, c, self.raster_scale(ctx, layer)))),
+            _ => None,
+        }
+    }
+
+    /// The proxy footage used for `item` under this render's Proxy Use, if any.
+    pub fn proxy_for(&self, item: ItemId) -> Option<&'a Footage> {
+        let it = self.project.item(item)?;
+        let px = it.proxy.as_deref()?;
+        (self.opts.proxy.uses(matches!(it.kind, ItemKind::Comp(_)), px.enabled) && px.footage.has_video).then_some(&px.footage)
+    }
+
+    /// A decoded frame of `f` as a layer buffer covering `w`×`h` layer pixels (the footage's
+    /// nominal size; proxies are scaled up to it), converted from its colour profile.
+    fn footage_buf(&self, img: &Image, f: &Footage, w: u32, h: u32) -> Buf {
+        let s = self.opts.scale;
+        let k = if img.width > 0 { w.max(1) as f64 / img.width as f64 } else { 1.0 };
+        // Keep native pixels when downsampling is small; resample otherwise.
+        let mut buf = match self.reduced_size(w, h) {
+            // The source resampled it already (`FootageSource::frame_at_size`).
+            Some(size) if (img.width, img.height) == size => Buf { img: img.clone(), offset: [0.0; 2], scale: s },
+            Some((rw, rh)) if k <= 1.0 + 1e-9 => Buf { img: effectcraft_raster::resample(img, rw, rh), offset: [0.0; 2], scale: s },
+            _ => Buf { img: img.clone(), offset: [0.0; 2], scale: 1.0 / k },
+        };
+        if let Some(c) = self.pipe.media_in(f) {
+            color::convert(&mut buf.img, &c);
+        }
+        buf
+    }
+
+    /// The size of `w` × `h` layer pixels in this render when it is reduced enough that footage
+    /// is resampled to it (below 3/4 scale).
+    fn reduced_size(&self, w: u32, h: u32) -> Option<(u32, u32)> {
+        let s = self.opts.scale;
+        (s < 0.75).then(|| (((w as f64 * s).round() as u32).max(1), ((h as f64 * s).round() as u32).max(1)))
+    }
+
+    /// Authored colours into the working space (linear working spaces).
+    fn authored(&self, mut buf: Buf) -> Buf {
+        if let Some(c) = self.pipe.authored_in() {
+            color::convert(&mut buf.img, &c);
+        }
+        buf
+    }
+
+    /// A footage frame at source time `t`, frame-blended between the two nearest source frames
+    /// when the layer's Frame Blending switch (and the comp's Enable Frame Blending) is on and
+    /// `t` falls between frames (footage rate ≠ comp rate, time stretch, time remapping).
+    /// `size`: a plain frame may come resampled to it ([`FootageSource::frame_at_size`]).
+    fn footage_frame(&self, ctx: &EvalCtx, layer: &Layer, item: ItemId, f: &Footage, t: Tick, size: Option<(u32, u32)>) -> Option<Arc<Image>> {
+        // Interpret Footage ▸ Separate Fields: each field is a frame at twice the rate.
+        if f.fields != effectcraft_project::FieldOrder::Off && matches!(f.kind, FootageKind::Video | FootageKind::Sequence) {
+            let field_rate = FrameRate::new(f.frame_rate.num * 2, f.frame_rate.den);
+            let i = field_rate.frame_at(t).max(0);
+            let img = self.footage.frame_with(item, f, f.frame_rate.tick_of(i / 2), None, self.pipe.float_curve(f))?;
+            let dominant_upper = f.fields == effectcraft_project::FieldOrder::UpperFirst;
+            // Upper field = even lines (0, 2, …).
+            let parity = if (i % 2 == 0) == dominant_upper { 0 } else { 1 };
+            return Some(Arc::new(interpret_pixels(&field_frame(&img, parity), f, self.pipe.linear_footage_space(f))));
+        }
+        // Interpretation is per pixel but not linear: it runs on the frame before resampling.
+        let size = size.filter(|_| !(f.invert_alpha || f.linear_light_applies()));
+        let img = self.footage_frame_raw(ctx, layer, item, f, t, size)?;
+        if f.invert_alpha || f.linear_light_applies() { Some(Arc::new(interpret_pixels(&img, f, self.pipe.linear_footage_space(f)))) } else { Some(img) }
+    }
+
+    fn footage_frame_raw(&self, ctx: &EvalCtx, layer: &Layer, item: ItemId, f: &Footage, t: Tick, size: Option<(u32, u32)>) -> Option<Arc<Image>> {
+        let mode = frame_blend_mode(ctx, layer);
+        let float = self.pipe.float_curve(f);
+        if mode != FrameBlend::Off && matches!(f.kind, FootageKind::Video | FootageKind::Sequence) {
+            let (i, w) = frame_position(t, f.frame_rate);
+            if w > 1e-6 {
+                // Blended frames are cached (Pixel Motion is expensive).
+                let key = self.cache.map(|_| {
+                    use std::hash::{Hash, Hasher};
+                    let mut h = std::collections::hash_map::DefaultHasher::new();
+                    (0x00f8_a3e5_u64, item, i, (w as f32).to_bits(), mode as u8, f.frame_rate.num, f.frame_rate.den, &f.path, float).hash(&mut h);
+                    h.finish()
+                });
+                if let (Some(c), Some(k)) = (self.cache, key)
+                    && let Some(b) = c.get(k)
+                {
+                    return Some(Arc::new(b.img.clone()));
+                }
+                let a = self.footage.frame_with(item, f, f.frame_rate.tick_of(i), None, float);
+                let b = self.footage.frame_with(item, f, f.frame_rate.tick_of(i + 1), None, float);
+                if let (Some(a), Some(b)) = (a, b) {
+                    let img = blend_frames(mode, &a, &b, w as f32);
+                    if let (Some(c), Some(k)) = (self.cache_to_keep(), key) {
+                        c.insert(k, Arc::new(Buf { img: img.clone(), offset: [0.0; 2], scale: 1.0 }));
+                    }
+                    return Some(Arc::new(img));
+                }
+            }
+        }
+        self.footage.frame_with(item, f, t, size, float)
+    }
+
+    /// Source → masks, clamped/quantised to the project depth.
+    fn masked_source(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Buf> {
+        let mut buf = match self.content_times(ctx, layer) {
+            Some(times) => self.blurred_source(ctx, layer, &times)?,
+            None => self.source(ctx, layer)?,
+        };
+        // A solid is filled with a quantised colour: only masks can take it off the grid.
+        let solid = matches!(layer.source, LayerSource::Solid { .. });
+        if masks::apply(ctx, layer, &mut buf, self.mask_blur(ctx, layer)) || !solid {
+            self.pipe.quantize(&mut buf.img);
+        }
+        Some(buf)
+    }
+
+    /// Fully processed layer buffer (source → masks → effects → layer styles, flattened).
+    /// Served from the layer cache when the layer's content key matches.
+    pub fn layer_buf(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Arc<Buf>> {
+        self.layer_buf_keyed(ctx, layer).map(|(b, _)| b)
+    }
+
+    /// [`Self::layer_buf`] in the blending space (linear with Blend Colors Using 1.0 Gamma).
+    pub fn blend_layer_buf(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Arc<Buf>> {
+        let (b, k) = self.layer_buf_keyed(ctx, layer)?;
+        Some(self.to_blend(b, k))
+    }
+
+    /// A buffer converted to the blending space (cached under a key derived from `key`).
+    pub(crate) fn to_blend(&self, b: Arc<Buf>, key: Option<u64>) -> Arc<Buf> {
+        let Some(c) = self.pipe.to_blend() else { return b };
+        let key = key.map(|k| cache::derive(k, 0x1ea7));
+        if let (Some(cache), Some(k)) = (self.cache, key)
+            && let Some(x) = cache.get(k)
+        {
+            return x;
+        }
+        let mut nb = (*b).clone();
+        color::convert(&mut nb.img, &c);
+        let nb = Arc::new(nb);
+        // The buffer the cache keeps (another worker's, if it kept one first).
+        match (self.cache_to_keep(), key) {
+            (Some(cache), Some(k)) => cache.insert(k, nb),
+            _ => nb,
+        }
+    }
+
+    fn layer_buf_keyed(&self, ctx: &EvalCtx, layer: &Layer) -> Option<(Arc<Buf>, Option<u64>)> {
+        let st = self.styled(ctx, layer, None)?;
+        if st.passes.is_empty() {
+            return Some((st.body, st.key));
+        }
+        let key = st.key.map(|k| cache::derive(k, 0xf1a7));
+        if let (Some(c), Some(k)) = (self.cache, key)
+            && let Some(b) = c.get(k)
+        {
+            return Some((b, key));
+        }
+        let flat = Arc::new(styles::Styled { passes: st.passes.iter().map(|(b, m)| ((**b).clone(), *m)).collect(), body: (*st.body).clone() }.flatten());
+        // The buffer the cache keeps (another worker's, if it kept one first).
+        let flat = match (self.cache_to_keep(), key) {
+            (Some(c), Some(k)) => c.insert(k, flat),
+            _ => flat,
+        };
+        Some((flat, key))
+    }
+
+    /// A layer's source pixels at the context time, before masks, effects and the transform
+    /// (what the motion tracker analyses, like After Effects' Layer panel). `None` for layers
+    /// without pixels.
+    pub fn layer_source(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Buf> {
+        self.source(ctx, layer)
+    }
+
+    /// Layer pixels after source → masks → effects (no layer styles).
+    pub fn content_buf(&self, ctx: &EvalCtx, layer: &Layer) -> Option<Arc<Buf>> {
+        self.content_buf_timed(ctx, layer, None).map(|(b, _)| b)
+    }
+
+    pub(crate) fn content_buf_timed(&self, ctx: &EvalCtx, layer: &Layer, mut timing: Option<&mut LayerTiming>) -> Option<(Arc<Buf>, Option<u64>)> {
+        let key = self.cache.and_then(|_| cache::layer_key(ctx, layer, self.raster_scale(ctx, layer), self.opts.draft, self.mb_on(ctx, layer)));
+        let key = self.content_key(ctx, layer, key);
+        if let (Some(c), Some(k)) = (self.cache, key)
+            && let Some(b) = c.get(k)
+        {
+            if let Some(t) = timing.as_deref_mut() {
+                t.cached = true;
+            }
+            return Some((b, key));
+        }
+        let buf = self.masked_source(ctx, layer)?;
+        let buf = Arc::new(self.apply_effects_timed(ctx, layer, buf, false, usize::MAX, timing.map(|t| &mut t.effects)));
+        // The buffer the cache keeps (another worker's, if it kept one first).
+        let buf = match (self.cache_to_keep(), key) {
+            (Some(c), Some(k)) => c.insert(k, buf),
+            _ => buf,
+        };
+        Some((buf, key))
+    }
+
+    /// A layer's input at the context time: source → masks → its first `effects` effects
+    /// (what Time effects read at neighbouring times), in effect space (see [`effect_bounds`]):
+    /// what effect `effects` sees. Served from / stored in the layer cache under its own key,
+    /// so scrubbing reuses frames rendered for earlier output frames.
+    pub fn layer_input(&self, ctx: &EvalCtx, layer: &Layer, effects: usize) -> Option<Arc<Buf>> {
+        let key = self.cache.and_then(|_| cache::input_key(ctx, layer, self.raster_scale(ctx, layer), self.opts.draft, self.mb_on(ctx, layer), effects));
+        let key = self.content_key(ctx, layer, key);
+        if let (Some(c), Some(k)) = (self.cache, key)
+            && let Some(b) = c.get(k)
+        {
+            return Some(b);
+        }
+        let mut buf = self.masked_source(ctx, layer)?;
+        let origin = ctx.effect_bounds(layer).1;
+        buf.rebase(origin);
+        if effects > 0 {
+            buf = self.effect_space_stack(ctx, layer, buf, EffectStack { adjustment: false, limit: effects, origin }, None);
+        }
+        let buf = Arc::new(buf);
+        // The buffer the cache keeps (another worker's, if it kept one first).
+        let buf = match (self.cache_to_keep(), key) {
+            (Some(c), Some(k)) => c.insert(k, buf),
+            _ => buf,
+        };
+        Some(buf)
+    }
+}
diff --git a/crates/render/src/shapes.rs b/crates/render/src/shapes.rs
index f8de5a290..511b32f3e 100644
--- a/crates/render/src/shapes.rs
+++ b/crates/render/src/shapes.rs
@@ -211,16 +211,16 @@ fn collect(ctx: &EvalCtx, layer: &Layer, contents: &PropGroup, arena: &mut Vec<B
             }
             "star" => {
                 let star = ctx.e(layer, g, "type") == 0;
-                let p = effectcraft_path::polystar(
+                let p = effectcraft_path::polystar(effectcraft_path::Polystar {
                     star,
-                    ctx.f(layer, g, "points", 5.0),
-                    ctx.v2(layer, g, "position", [0.0; 2]),
-                    ctx.f(layer, g, "rotation", 0.0),
-                    ctx.f(layer, g, "innerRadius", 50.0),
-                    ctx.f(layer, g, "outerRadius", 100.0),
-                    ctx.f(layer, g, "innerRoundness", 0.0),
-                    ctx.f(layer, g, "outerRoundness", 0.0),
-                );
+                    points: ctx.f(layer, g, "points", 5.0),
+                    pos: ctx.v2(layer, g, "position", [0.0; 2]),
+                    rotation: ctx.f(layer, g, "rotation", 0.0),
+                    inner: ctx.f(layer, g, "innerRadius", 50.0),
+                    outer: ctx.f(layer, g, "outerRadius", 100.0),
+                    inner_round: ctx.f(layer, g, "innerRoundness", 0.0),
+                    outer_round: ctx.f(layer, g, "outerRoundness", 0.0),
+                });
                 push_shape(ctx, layer, g, p, arena, &mut live);
             }
             "path" => {
@@ -324,6 +324,7 @@ fn collect(ctx: &EvalCtx, layer: &Layer, contents: &PropGroup, arena: &mut Vec<B
                     speed: ctx.f(layer, g, "speed", 2.0),
                     correlation: ctx.f(layer, g, "correlation", 50.0),
                     phase_deg: ctx.f(layer, g, "phase", 0.0),
+                    spatial_phase_deg: ctx.f(layer, g, "spatialPhase", 0.0),
                     seed: ctx.f(layer, g, "seed", 0.0),
                 };
                 let t = layer.layer_time(ctx.time).seconds();
diff --git a/crates/render/src/shapes/tests.rs b/crates/render/src/shapes/tests.rs
index 1dbf67a7a..2ca03b4f6 100644
--- a/crates/render/src/shapes/tests.rs
+++ b/crates/render/src/shapes/tests.rs
@@ -258,6 +258,24 @@ fn round_corners_clip_corner_pixels() {
     assert!((coverage(&img) - std::f32::consts::PI * 400.0).abs() < 15.0, "{}", coverage(&img));
 }
 
+/// Wiggle Paths' Spatial Phase changes the drawn shape; a whole turn draws it as at 0°.
+#[test]
+fn wiggle_paths_spatial_phase_renders() {
+    let render = |phase: f64| {
+        let (p, cid) = shape_comp(|ids| {
+            vec![
+                build::shape_ellipse(ids, [60.0, 60.0], [0.0, 0.0]),
+                op(ids, "wiggle", &[("size", Value::Scalar(8.0)), ("correlation", Value::Scalar(0.0)), ("spatialPhase", Value::Scalar(phase))]),
+                build::shape_fill(ids, RED),
+            ]
+        });
+        render_frame(&p, cid, Tick::from_seconds_f64(0.5), 1.0).data
+    };
+    let zero = render(0.0);
+    assert!(render(90.0) != zero, "Spatial Phase 90° draws the shape of 0°");
+    assert!(render(360.0) == zero, "Spatial Phase 360° draws another shape than 0°");
+}
+
 #[test]
 fn wiggle_paths_vary_over_time_deterministically() {
     let (p, cid) = shape_comp(|ids| {
diff --git a/crates/render/src/tests.rs b/crates/render/src/tests.rs
index 100ceda2f..079274499 100644
--- a/crates/render/src/tests.rs
+++ b/crates/render/src/tests.rs
@@ -6,6 +6,24 @@ use effectcraft_time::{FrameRate, Tick};
 
 use crate::render_frame;
 
+mod audio_fx;
+mod auto;
+mod aux_channels;
+mod collapse;
+mod color;
+mod footage_size;
+mod frame_blend;
+mod guides;
+mod mask_blur;
+mod mask_expansion;
+mod motion_tile;
+mod nested;
+mod paint;
+mod remap;
+mod roi;
+mod styles;
+mod time;
+
 fn setup() -> (Project, ItemId, Comp) {
     let mut p = Project::default();
     // Exact float maths; 8/16 bpc quantisation has its own tests (tests_color).
diff --git a/crates/render/src/tests_audio_fx.rs b/crates/render/src/tests/audio_fx.rs
similarity index 100%
rename from crates/render/src/tests_audio_fx.rs
rename to crates/render/src/tests/audio_fx.rs
diff --git a/crates/render/src/tests_auto.rs b/crates/render/src/tests/auto.rs
similarity index 100%
rename from crates/render/src/tests_auto.rs
rename to crates/render/src/tests/auto.rs
diff --git a/crates/render/src/tests_aux.rs b/crates/render/src/tests/aux_channels.rs
similarity index 100%
rename from crates/render/src/tests_aux.rs
rename to crates/render/src/tests/aux_channels.rs
diff --git a/crates/render/src/tests_collapse.rs b/crates/render/src/tests/collapse.rs
similarity index 100%
rename from crates/render/src/tests_collapse.rs
rename to crates/render/src/tests/collapse.rs
diff --git a/crates/render/src/tests_color.rs b/crates/render/src/tests/color.rs
similarity index 100%
rename from crates/render/src/tests_color.rs
rename to crates/render/src/tests/color.rs
diff --git a/crates/render/src/tests_footage_size.rs b/crates/render/src/tests/footage_size.rs
similarity index 100%
rename from crates/render/src/tests_footage_size.rs
rename to crates/render/src/tests/footage_size.rs
diff --git a/crates/render/src/tests_frame_blend.rs b/crates/render/src/tests/frame_blend.rs
similarity index 100%
rename from crates/render/src/tests_frame_blend.rs
rename to crates/render/src/tests/frame_blend.rs
diff --git a/crates/render/src/tests_guides.rs b/crates/render/src/tests/guides.rs
similarity index 100%
rename from crates/render/src/tests_guides.rs
rename to crates/render/src/tests/guides.rs
diff --git a/crates/render/src/tests_mask_blur.rs b/crates/render/src/tests/mask_blur.rs
similarity index 100%
rename from crates/render/src/tests_mask_blur.rs
rename to crates/render/src/tests/mask_blur.rs
diff --git a/crates/render/src/tests_mask_expansion.rs b/crates/render/src/tests/mask_expansion.rs
similarity index 100%
rename from crates/render/src/tests_mask_expansion.rs
rename to crates/render/src/tests/mask_expansion.rs
diff --git a/crates/render/src/tests_motion_tile.rs b/crates/render/src/tests/motion_tile.rs
similarity index 100%
rename from crates/render/src/tests_motion_tile.rs
rename to crates/render/src/tests/motion_tile.rs
diff --git a/crates/render/src/tests_nested.rs b/crates/render/src/tests/nested.rs
similarity index 100%
rename from crates/render/src/tests_nested.rs
rename to crates/render/src/tests/nested.rs
diff --git a/crates/render/src/tests_paint.rs b/crates/render/src/tests/paint.rs
similarity index 100%
rename from crates/render/src/tests_paint.rs
rename to crates/render/src/tests/paint.rs
diff --git a/crates/render/src/tests_remap.rs b/crates/render/src/tests/remap.rs
similarity index 100%
rename from crates/render/src/tests_remap.rs
rename to crates/render/src/tests/remap.rs
diff --git a/crates/render/src/tests_roi.rs b/crates/render/src/tests/roi.rs
similarity index 100%
rename from crates/render/src/tests_roi.rs
rename to crates/render/src/tests/roi.rs
diff --git a/crates/render/src/tests_styles.rs b/crates/render/src/tests/styles.rs
similarity index 100%
rename from crates/render/src/tests_styles.rs
rename to crates/render/src/tests/styles.rs
diff --git a/crates/render/src/tests_time.rs b/crates/render/src/tests/time.rs
similarity index 100%
rename from crates/render/src/tests_time.rs
rename to crates/render/src/tests/time.rs
diff --git a/crates/render/src/text.rs b/crates/render/src/text.rs
index 496bc3a60..e1954b597 100644
--- a/crates/render/src/text.rs
+++ b/crates/render/src/text.rs
@@ -287,11 +287,13 @@ pub fn char_transforms(ctx: &EvalCtx, layer: &Layer, text: &PropGroup, lay: &Tex
         let pos = get("position").map(|v| c3(v, 0.0));
         let anchor = get("anchor").map(|v| c3(v, 0.0));
         let scale = get("scale").map(|v| c3(v, 100.0));
-        let rot = get1("rotation");
-        let rx = get1("rotationX");
-        let ry = get1("rotationY");
-        let skew = get1("skew");
-        let skew_axis = get1("skewAxis");
+        let angles = CharacterAngles {
+            rotation: get1("rotation"),
+            rotation_x: get1("rotationX"),
+            rotation_y: get1("rotationY"),
+            skew: get1("skew"),
+            skew_axis: get1("skewAxis"),
+        };
         let op = get1("opacity");
         let fill = props.get("fillColor").map(|p| ctx.value(layer, p).as_color());
         let stroke = props.get("strokeColor").map(|p| ctx.value(layer, p).as_color());
@@ -338,21 +340,7 @@ pub fn char_transforms(ctx: &EvalCtx, layer: &Layer, text: &PropGroup, lay: &Tex
                     c.scale[d] *= 1.0 + (s[d] / 100.0 - 1.0) * k3[d];
                 }
             }
-            if let Some(r) = rot {
-                c.rotation += r * k;
-            }
-            if let Some(r) = rx {
-                c.rotation_x += r * k;
-            }
-            if let Some(r) = ry {
-                c.rotation_y += r * k;
-            }
-            if let Some(s) = skew {
-                c.skew += s * k;
-            }
-            if let Some(a) = skew_axis {
-                c.skew_axis = a;
-            }
+            angles.apply(c, k);
             if let Some(o) = op {
                 c.opacity *= 1.0 + (o / 100.0 - 1.0) * k;
             }
@@ -381,17 +369,7 @@ pub fn char_transforms(ctx: &EvalCtx, layer: &Layer, text: &PropGroup, lay: &Tex
             if let Some(w) = sw {
                 c.stroke_width += w * k;
             }
-            if let Some(t) = tracking {
-                let t = t * k;
-                match tracking_type {
-                    1 => c.track_before += t,
-                    2 => c.track_after += t,
-                    _ => {
-                        c.track_before += t * 0.5;
-                        c.track_after += t * 0.5;
-                    }
-                }
-            }
+            apply_tracking(c, tracking, tracking_type, k);
             if let Some(a) = line_anchor
                 && k.abs() >= c.line_anchor_k
             {
@@ -432,6 +410,50 @@ pub fn char_transforms(ctx: &EvalCtx, layer: &Layer, text: &PropGroup, lay: &Tex
     out
 }
 
+/// Optional animator orientation properties; an omitted property leaves the glyph unchanged.
+struct CharacterAngles {
+    rotation: Option<f64>,
+    rotation_x: Option<f64>,
+    rotation_y: Option<f64>,
+    skew: Option<f64>,
+    skew_axis: Option<f64>,
+}
+
+impl CharacterAngles {
+    fn apply(&self, c: &mut CharXf, k: f64) {
+        if let Some(r) = self.rotation {
+            c.rotation += r * k;
+        }
+        if let Some(r) = self.rotation_x {
+            c.rotation_x += r * k;
+        }
+        if let Some(r) = self.rotation_y {
+            c.rotation_y += r * k;
+        }
+        if let Some(s) = self.skew {
+            c.skew += s * k;
+        }
+        if let Some(a) = self.skew_axis {
+            c.skew_axis = a;
+        }
+    }
+}
+
+/// Distribute selected tracking before and/or after a glyph according to Tracking Type.
+fn apply_tracking(c: &mut CharXf, tracking: Option<f64>, tracking_type: u32, k: f64) {
+    if let Some(t) = tracking {
+        let t = t * k;
+        match tracking_type {
+            1 => c.track_before += t,
+            2 => c.track_after += t,
+            _ => {
+                c.track_before += t * 0.5;
+                c.track_after += t * 0.5;
+            }
+        }
+    }
+}
+
 /// Character Offset / Character Value substitution (None = unchanged).
 pub fn substitute(ch: char, x: &CharXf) -> Option<char> {
     if ch.is_whitespace() {
diff --git a/crates/render/src/three_d/mod.rs b/crates/render/src/three_d.rs
similarity index 100%
rename from crates/render/src/three_d/mod.rs
rename to crates/render/src/three_d.rs
diff --git a/crates/render/src/three_d/adv/mod.rs b/crates/render/src/three_d/adv.rs
similarity index 100%
rename from crates/render/src/three_d/adv/mod.rs
rename to crates/render/src/three_d/adv.rs
diff --git a/crates/render/src/three_d/adv/shade.rs b/crates/render/src/three_d/adv/shade.rs
index 9acc852fe..0ebd0b1ac 100644
--- a/crates/render/src/three_d/adv/shade.rs
+++ b/crates/render/src/three_d/adv/shade.rs
@@ -82,9 +82,20 @@ pub fn f_schlick(f0: [f32; 3], v_h: f32) -> [f32; 3] {
     [f0[0] + (1.0 - f0[0]) * k, f0[1] + (1.0 - f0[1]) * k, f0[2] + (1.0 - f0[2]) * k]
 }
 
+/// Surface parameters used by the direct-light BRDF after texture sampling.
+#[derive(Clone, Copy)]
+pub struct BrdfSurface {
+    pub base: [f32; 3],
+    pub metallic: f32,
+    pub roughness: f32,
+    pub specular: f32,
+    pub diffuse: f32,
+}
+
 /// Cook–Torrance BRDF × N·L × π for one light: (diffuse colour factor, specular colour).
 /// Returned as the reflected fraction of the light's irradiance.
-pub fn brdf(base: [f32; 3], metallic: f32, rough: f32, spec_k: f32, diff_k: f32, n: [f32; 3], v: [f32; 3], l: [f32; 3]) -> [f32; 3] {
+pub fn brdf(surface: BrdfSurface, n: [f32; 3], v: [f32; 3], l: [f32; 3]) -> [f32; 3] {
+    let BrdfSurface { base, metallic, roughness: rough, specular: spec_k, diffuse: diff_k } = surface;
     let n_l = dot(n, l);
     if n_l <= 0.0 {
         return [0.0; 3];
@@ -484,7 +495,7 @@ pub fn shade(s: &Scene, f: &Frag) -> Option<[f32; 4]> {
             continue;
         }
         let sh = if m.receives_shadows { light_shadow(s, l, f.pos, ng, n_l) } else { 1.0 };
-        let b = brdf(rgb, metallic, rough, m.specular_k, m.diffuse_k, n, v, to_l);
+        let b = brdf(BrdfSurface { base: rgb, metallic, roughness: rough, specular: m.specular_k, diffuse: m.diffuse_k }, n, v, to_l);
         for c in 0..3 {
             out[c] += b[c] * l.color[c] * k * sh;
         }
diff --git a/crates/render/src/three_d/adv/tests.rs b/crates/render/src/three_d/adv/tests.rs
index 3f5ee4813..f9a0f2066 100644
--- a/crates/render/src/three_d/adv/tests.rs
+++ b/crates/render/src/three_d/adv/tests.rs
@@ -16,7 +16,7 @@ fn brdf_matches_cook_torrance_formula() {
     let v = shade::norm([0.3, 0.1, 1.0]);
     let l = shade::norm([-0.4, 0.2, 1.0]);
     let (base, metal, rough) = ([0.8, 0.4, 0.2], 0.3f32, 0.45f32);
-    let got = shade::brdf(base, metal, rough, 1.0, 1.0, n, v, l);
+    let got = shade::brdf(shade::BrdfSurface { base, metallic: metal, roughness: rough, specular: 1.0, diffuse: 1.0 }, n, v, l);
     let h = shade::norm([v[0] + l[0], v[1] + l[1], v[2] + l[2]]);
     let (nv, nl, nh, vh) = (shade::dot(n, v), shade::dot(n, l), shade::dot(n, h), shade::dot(v, h));
     let a2 = (rough * rough).powi(2);
@@ -30,9 +30,9 @@ fn brdf_matches_cook_torrance_formula() {
         assert!((got[c] - expect).abs() < 1e-5, "channel {c}: {} vs {expect}", got[c]);
     }
     // No light from behind the surface.
-    assert_eq!(shade::brdf(base, metal, rough, 1.0, 1.0, n, v, [0.0, 0.0, -1.0]), [0.0; 3]);
+    assert_eq!(shade::brdf(shade::BrdfSurface { base, metallic: metal, roughness: rough, specular: 1.0, diffuse: 1.0 }, n, v, [0.0, 0.0, -1.0]), [0.0; 3]);
     // A white rough dielectric lit head-on reflects about its base colour (π folded in).
-    let w = shade::brdf([1.0; 3], 0.0, 1.0, 1.0, 1.0, n, n, n);
+    let w = shade::brdf(shade::BrdfSurface { base: [1.0; 3], metallic: 0.0, roughness: 1.0, specular: 1.0, diffuse: 1.0 }, n, n, n);
     assert!(w[0] > 0.95 && w[0] < 1.05, "{w:?}");
 }
 
diff --git a/crates/render/src/three_d/compose.rs b/crates/render/src/three_d/compose.rs
index 929b48d45..8e932819a 100644
--- a/crates/render/src/three_d/compose.rs
+++ b/crates/render/src/three_d/compose.rs
@@ -197,7 +197,7 @@ fn mb_samples(r: &Renderer, ctx: &EvalCtx, layer: &Layer) -> usize {
 /// Prepare a layer (buffer, geometry, material). `None` when it shows nothing.
 pub(crate) fn prepare<'a>(r: &Renderer, ctx: &EvalCtx<'a>, layer: &'a Layer, order: usize, out: (u32, u32), in_run: bool) -> Option<Item<'a>> {
     let buf = r.blend_layer_buf(ctx, layer)?;
-    prepare_with(r, ctx, layer, order, out, in_run, buf, Mat4::IDENTITY)
+    prepare_with(r, ctx, layer, order, out, in_run, PlaneInput { buf, local: Mat4::IDENTITY })
 }
 
 /// Prepare a layer as planes: one per character for per-character 3D text, else one.
@@ -205,24 +205,21 @@ pub(crate) fn prepare_all<'a>(r: &Renderer, ctx: &EvalCtx<'a>, layer: &'a Layer,
     if crate::text::per_char_3d(ctx, layer) {
         return crate::text::per_char_planes(ctx, layer, r.opts.scale)
             .into_iter()
-            .filter_map(|(buf, m)| prepare_with(r, ctx, layer, order, out, in_run, r.to_blend(Arc::new(buf), None), m))
+            .filter_map(|(buf, m)| prepare_with(r, ctx, layer, order, out, in_run, PlaneInput { buf: r.to_blend(Arc::new(buf), None), local: m }))
             .collect();
     }
     prepare(r, ctx, layer, order, out, in_run).into_iter().collect()
 }
 
-/// Prepare a plane showing `buf`, whose space maps into the layer through `local`.
-#[allow(clippy::too_many_arguments)]
-fn prepare_with<'a>(
-    r: &Renderer,
-    ctx: &EvalCtx<'a>,
-    layer: &'a Layer,
-    order: usize,
-    out: (u32, u32),
-    in_run: bool,
-    mut buf: Arc<Buf>,
+/// A processed plane and its mapping into the layer's coordinate system.
+struct PlaneInput {
+    buf: Arc<Buf>,
     local: Mat4,
-) -> Option<Item<'a>> {
+}
+
+/// Prepare the plane's geometry, motion samples and material.
+fn prepare_with<'a>(r: &Renderer, ctx: &EvalCtx<'a>, layer: &'a Layer, order: usize, out: (u32, u32), in_run: bool, plane: PlaneInput) -> Option<Item<'a>> {
+    let PlaneInput { mut buf, local } = plane;
     if buf.img.is_empty() {
         return None;
     }
diff --git a/crates/script/src/lib.rs b/crates/script/src/lib.rs
index 5c1f8cdbb..11d837677 100644
--- a/crates/script/src/lib.rs
+++ b/crates/script/src/lib.rs
@@ -88,28 +88,7 @@ pub fn run_code(s: &mut Session, code: &str, name: &str) -> Outcome {
 
 #[cfg(test)]
 mod tests;
-#[cfg(test)]
-mod tests_callable;
-#[cfg(test)]
-mod tests_ease_presets;
-#[cfg(test)]
-mod tests_include;
-#[cfg(test)]
-mod tests_panels;
-#[cfg(test)]
-mod tests_tasks;
-#[cfg(test)]
-mod tests_ui;
-#[cfg(test)]
-mod tests_ui_more;
 
 // #760: `$.evalFile` and `BridgeTalk`.
-#[cfg(test)]
-mod tests_evalfile;
 // `/browser/…` is the web editor's file table, an absolute path on wasm; on Windows it has no
 // drive, so the script runtime resolves it under the current drive, where the host holds nothing.
-#[cfg(test)]
-#[cfg(not(windows))]
-mod tests_services;
-#[cfg(test)]
-mod tests_ui_mouse;
diff --git a/crates/script/src/matchnames.rs b/crates/script/src/matchnames.rs
index 205697b60..b64aaab37 100644
--- a/crates/script/src/matchnames.rs
+++ b/crates/script/src/matchnames.rs
@@ -209,6 +209,14 @@ const SHAPE_PROPS: &[(&str, &str, &str)] = &[
     ("twist", "angle", "ADBE Vector Twist Angle"),
     ("twist", "center", "ADBE Vector Twist Center"),
     ("merge", "mode", "ADBE Vector Merge Type"),
+    ("wiggle", "size", "ADBE Vector Roughen Size"),
+    ("wiggle", "detail", "ADBE Vector Roughen Detail"),
+    ("wiggle", "points", "ADBE Vector Roughen Points"),
+    ("wiggle", "speed", "ADBE Vector Temporal Freq"),
+    ("wiggle", "correlation", "ADBE Vector Correlation"),
+    ("wiggle", "phase", "ADBE Vector Temporal Phase"),
+    ("wiggle", "spatialPhase", "ADBE Vector Spatial Phase"),
+    ("wiggle", "seed", "ADBE Vector Random Seed"),
 ];
 
 /// Effects: our effect id → AE match name (the documented ones; the rest keep our id).
diff --git a/crates/script/src/prelude.js b/crates/script/src/prelude.js
index ce64e221b..f012ce128 100644
--- a/crates/script/src/prelude.js
+++ b/crates/script/src/prelude.js
@@ -189,7 +189,12 @@ BridgeTalk.pump = function () { return false; };
 
 // ------------------------------------------------------------------ File / Folder
 
-function __join(a, b) { return a.replace(/[\/\\]+$/, "") + "/" + b; }
+function __trimPathSeparators(path) {
+  var end = path.length;
+  while (end > 0 && (path.charAt(end - 1) === "/" || path.charAt(end - 1) === "\\")) end--;
+  return path.slice(0, end);
+}
+function __join(a, b) { return __trimPathSeparators(a) + "/" + b; }
 
 function File(path) {
   if (!(this instanceof File)) return new File(path);
@@ -292,9 +297,9 @@ Folder.prototype = {
   get fsName() { return this.__path; },
   get fullName() { return this.__path; },
   get absoluteURI() { return this.__path; },
-  get name() { return this.__path.replace(/[\/\\]+$/, "").split(/[\/\\]/).pop(); },
+  get name() { return __trimPathSeparators(this.__path).split(/[\/\\]/).pop(); },
   get displayName() { return this.name; },
-  get path() { var p = this.__path.replace(/[\/\\]+$/, "").split(/[\/\\]/); p.pop(); return p.join("/"); },
+  get path() { var p = __trimPathSeparators(this.__path).split(/[\/\\]/); p.pop(); return p.join("/"); },
   get parent() { return new Folder(this.path); },
   get exists() { return JSON.parse(__file("isDir", this.__path)) === true; },
   toString: function () { return this.__path; },
diff --git a/crates/script/src/socket.rs b/crates/script/src/socket.rs
index 6b2976dc1..4103f12c1 100644
--- a/crates/script/src/socket.rs
+++ b/crates/script/src/socket.rs
@@ -55,7 +55,7 @@ mod imp {
     use std::sync::{Arc, Mutex};
     use std::time::{Duration, Instant};
 
-    use super::*;
+    use super::{J, err, json};
 
     enum Sock {
         Stream { s: TcpStream, buf: Vec<u8>, eof: bool },
diff --git a/crates/script/src/tests.rs b/crates/script/src/tests.rs
index 82f8ad289..a2f674d0a 100644
--- a/crates/script/src/tests.rs
+++ b/crates/script/src/tests.rs
@@ -10,6 +10,18 @@ use serde_json::{Value, json};
 
 use crate::{Outcome, run_code};
 
+mod callable;
+mod ease_presets;
+mod evalfile;
+mod include;
+mod panels;
+#[cfg(not(windows))]
+mod services;
+mod tasks;
+mod ui;
+mod ui_more;
+mod ui_mouse;
+
 fn session() -> Session {
     let mut s = Session { expr: Some(Arc::new(effectcraft_expr::Expressions)), expr_check: Some(effectcraft_expr::check_syntax), ..Default::default() };
     crate::install(&mut s);
@@ -258,6 +270,44 @@ fn an_undefined_name_mentioned_earlier_reports_its_use_in_the_reading_function()
     assert_eq!(e.line, Some(6), "{e:?}");
 }
 
+/// Scripts reach Wiggle Paths' properties, Spatial Phase included, by their match names.
+#[test]
+fn wiggle_paths_properties_by_match_name() {
+    let mut s = session();
+    let o = ok(
+        &mut s,
+        r#"
+        var c = app.project.items.addComp("W", 200, 200, 1, 2, 30);
+        var sh = c.layers.addShape();
+        var w = sh.property("ADBE Root Vectors Group").addProperty("ADBE Vector Filter - Roughen");
+        w.property("ADBE Vector Spatial Phase").setValue(45);
+        var names = [];
+        for (var i = 1; i <= w.numProperties; i++) names.push(w.property(i).matchName);
+        [w.matchName, w.property("ADBE Vector Spatial Phase").name, names]
+        "#,
+    );
+    assert_eq!(
+        o.result,
+        json!([
+            "ADBE Vector Filter - Roughen",
+            "Spatial Phase",
+            [
+                "ADBE Vector Roughen Size",
+                "ADBE Vector Roughen Detail",
+                "ADBE Vector Roughen Points",
+                "ADBE Vector Temporal Freq",
+                "ADBE Vector Correlation",
+                "ADBE Vector Temporal Phase",
+                "ADBE Vector Spatial Phase",
+                "ADBE Vector Random Seed"
+            ]
+        ])
+    );
+    let (_, c) = comp_named(&s, "W");
+    let sh = c.layers.iter().find(|l| l.props.sub("contents").is_some()).unwrap();
+    assert_eq!(sh.props.prop("contents/wiggle/spatialPhase").unwrap().value, KV::Scalar(45.0));
+}
+
 #[test]
 fn match_names_and_lookups() {
     let mut s = session();
@@ -444,6 +494,38 @@ fn layers_items_and_markers() {
     );
 }
 
+#[test]
+fn folder_paths_trim_trailing_separators() {
+    let mut s = session();
+    let o = ok(
+        &mut s,
+        r#"
+        var paths = ['', '/', '///', 'a/b/', 'a\\b\\/', 'a/b', 'a/\n'];
+        var result = paths.map(function (path) {
+          var folder = new Folder(path);
+          return [folder.name, folder.path, __join(path, 'child')];
+        });
+        // A long run followed by a non-separator used to cause quadratic regex backtracking.
+        var longPath = Array(20001).join('/') + 'x';
+        result.push([new Folder(longPath).name, new Folder(longPath).path.length, __join(longPath, 'child').length]);
+        result
+        "#,
+    );
+    assert_eq!(
+        o.result,
+        json!([
+            ["", "", "/child"],
+            ["", "", "/child"],
+            ["", "", "/child"],
+            ["b", "a", "a/b/child"],
+            ["b", "a", "a\\b/child"],
+            ["b", "a", "a/b/child"],
+            ["\n", "a", "a/\n/child"],
+            ["x", 19999, 20007]
+        ])
+    );
+}
+
 #[test]
 fn security_gate_for_files() {
     let dir = std::env::temp_dir().join(format!("ec-script-gate-{}", std::process::id()));
diff --git a/crates/script/src/tests_callable.rs b/crates/script/src/tests/callable.rs
similarity index 100%
rename from crates/script/src/tests_callable.rs
rename to crates/script/src/tests/callable.rs
diff --git a/crates/script/src/tests_ease_presets.rs b/crates/script/src/tests/ease_presets.rs
similarity index 100%
rename from crates/script/src/tests_ease_presets.rs
rename to crates/script/src/tests/ease_presets.rs
diff --git a/crates/script/src/tests_evalfile.rs b/crates/script/src/tests/evalfile.rs
similarity index 100%
rename from crates/script/src/tests_evalfile.rs
rename to crates/script/src/tests/evalfile.rs
diff --git a/crates/script/src/tests_include.rs b/crates/script/src/tests/include.rs
similarity index 100%
rename from crates/script/src/tests_include.rs
rename to crates/script/src/tests/include.rs
diff --git a/crates/script/src/tests_panels.rs b/crates/script/src/tests/panels.rs
similarity index 100%
rename from crates/script/src/tests_panels.rs
rename to crates/script/src/tests/panels.rs
diff --git a/crates/script/src/tests_services.rs b/crates/script/src/tests/services.rs
similarity index 100%
rename from crates/script/src/tests_services.rs
rename to crates/script/src/tests/services.rs
diff --git a/crates/script/src/tests_tasks.rs b/crates/script/src/tests/tasks.rs
similarity index 100%
rename from crates/script/src/tests_tasks.rs
rename to crates/script/src/tests/tasks.rs
diff --git a/crates/script/src/tests_ui.rs b/crates/script/src/tests/ui.rs
similarity index 100%
rename from crates/script/src/tests_ui.rs
rename to crates/script/src/tests/ui.rs
diff --git a/crates/script/src/tests_ui_more.rs b/crates/script/src/tests/ui_more.rs
similarity index 100%
rename from crates/script/src/tests_ui_more.rs
rename to crates/script/src/tests/ui_more.rs
diff --git a/crates/script/src/tests_ui_mouse.rs b/crates/script/src/tests/ui_mouse.rs
similarity index 100%
rename from crates/script/src/tests_ui_mouse.rs
rename to crates/script/src/tests/ui_mouse.rs
diff --git a/crates/segment/src/lib.rs b/crates/segment/src/lib.rs
index e04b7c336..adeb44881 100644
--- a/crates/segment/src/lib.rs
+++ b/crates/segment/src/lib.rs
@@ -14,8 +14,8 @@
 //!   so official weights load as published.
 //! - [`mobilesam`]: MobileSAM (Apache-2.0) and [`mediapipe`]: MediaPipe Face Landmarker
 //!   (Apache-2.0), in plain Rust ([`nn`] kernels on rayon).
-#![forbid(unsafe_code)]
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::todo, clippy::unreachable)]
+#![forbid(unsafe_code)]
 
 pub mod face;
 pub mod mediapipe;
diff --git a/crates/segment/src/mobilesam.rs b/crates/segment/src/mobilesam.rs
index 22d98ba7c..6599b018a 100644
--- a/crates/segment/src/mobilesam.rs
+++ b/crates/segment/src/mobilesam.rs
@@ -191,7 +191,7 @@ impl Block {
                         v[t * dim + hh * hd..][..hd].copy_from_slice(&s[2 * hd..]);
                     }
                 }
-                nn::attention(&q, &k, &v, n, n, heads, hd, Some(&self.bias))
+                nn::attention(&q, &k, &v, nn::AttentionShape { query_tokens: n, key_tokens: n, heads, head_dim: hd }, Some(&self.bias))
             })
             .collect();
         // Un-window into the real grid, project, residual.
@@ -325,7 +325,7 @@ impl Attn {
     fn forward(&self, q: &[f32], nq: usize, k: &[f32], v: &[f32], nk: usize) -> Vec<f32> {
         let (q, k, v) = (self.q.forward(q, nq), self.k.forward(k, nk), self.v.forward(v, nk));
         let heads = 8;
-        let o = nn::attention(&q, &k, &v, nq, nk, heads, self.q.out / heads, None);
+        let o = nn::attention(&q, &k, &v, nn::AttentionShape { query_tokens: nq, key_tokens: nk, heads, head_dim: self.q.out / heads }, None);
         self.out.forward(&o, nq)
     }
 }
diff --git a/crates/segment/src/nn.rs b/crates/segment/src/nn.rs
index 4cf7a5344..713b392b8 100644
--- a/crates/segment/src/nn.rs
+++ b/crates/segment/src/nn.rs
@@ -334,9 +334,19 @@ pub fn softmax_rows(x: &mut [f32], n: usize) {
     }
 }
 
-/// Multi-head scaled dot-product attention of `nq` queries over `nk` keys/values, each `heads ×
-/// hd` wide (token-major, heads side by side), plus an optional per-head bias `[heads × nq × nk]`.
-pub fn attention(q: &[f32], k: &[f32], v: &[f32], nq: usize, nk: usize, heads: usize, hd: usize, bias: Option<&[f32]>) -> Vec<f32> {
+/// Token counts and channel layout shared by the query, key and value tensors.
+#[derive(Clone, Copy, Debug)]
+pub struct AttentionShape {
+    pub query_tokens: usize,
+    pub key_tokens: usize,
+    pub heads: usize,
+    pub head_dim: usize,
+}
+
+/// Multi-head scaled dot-product attention with token-major tensors, heads side by side,
+/// and an optional per-head bias `[heads × query_tokens × key_tokens]`.
+pub fn attention(q: &[f32], k: &[f32], v: &[f32], shape: AttentionShape, bias: Option<&[f32]>) -> Vec<f32> {
+    let AttentionShape { query_tokens: nq, key_tokens: nk, heads, head_dim: hd } = shape;
     let dim = heads * hd;
     let mut out = vec![0.0f32; nq * dim];
     if q.len() < nq * dim || k.len() < nk * dim || v.len() < nk * dim {
@@ -372,6 +382,37 @@ pub fn attention(q: &[f32], k: &[f32], v: &[f32], nq: usize, nk: usize, heads: u
 mod tests {
     use super::*;
 
+    #[test]
+    fn multi_head_cross_attention_matches_direct_sums() {
+        let shape = AttentionShape { query_tokens: 2, key_tokens: 3, heads: 2, head_dim: 2 };
+        let q = [1.0, -0.5, 0.25, 2.0, -1.0, 0.75, 1.5, -0.25];
+        let k = [0.5, 1.0, -0.5, 0.25, 1.5, -0.25, 0.75, 1.0, -1.0, 0.5, 2.0, -1.5];
+        let v = [1.0, 2.0, 3.0, 4.0, -1.0, 0.5, 1.5, -2.0, 0.25, 0.75, -0.5, 2.5];
+        let bias = [0.0, 0.5, -0.5, 1.0, 0.0, -1.0, -0.25, 0.25, 0.5, 0.0, -0.5, 1.0];
+        for bias in [None, Some(bias.as_slice())] {
+            let actual = attention(&q, &k, &v, shape, bias);
+            for query in 0..shape.query_tokens {
+                for head in 0..shape.heads {
+                    let mut scores: Vec<f32> = (0..shape.key_tokens)
+                        .map(|key| {
+                            let dot: f32 = (0..shape.head_dim).map(|channel| q[query * 4 + head * 2 + channel] * k[key * 4 + head * 2 + channel]).sum();
+                            dot / (shape.head_dim as f32).sqrt() + bias.map_or(0.0, |b| b[(head * 2 + query) * 3 + key])
+                        })
+                        .collect();
+                    let max = scores.iter().copied().fold(f32::NEG_INFINITY, f32::max);
+                    for score in &mut scores {
+                        *score = (*score - max).exp();
+                    }
+                    let total: f32 = scores.iter().sum();
+                    for channel in 0..shape.head_dim {
+                        let expected: f32 = scores.iter().enumerate().map(|(key, score)| score / total * v[key * 4 + head * 2 + channel]).sum();
+                        assert!((actual[query * 4 + head * 2 + channel] - expected).abs() < 1e-6);
+                    }
+                }
+            }
+        }
+    }
+
     #[test]
     fn gemm_matches_naive() {
         let (m, k, n) = (130, 17, 9);
diff --git a/crates/segment/src/tflite.rs b/crates/segment/src/tflite.rs
index 9cd34c6da..34e85dfab 100644
--- a/crates/segment/src/tflite.rs
+++ b/crates/segment/src/tflite.rs
@@ -763,361 +763,4 @@ fn concat(parts: &[(&[f32], &Vec<usize>)], axis: usize) -> Result<Vec<f32>> {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn same_padding_matches_tensorflow() {
-        // TensorFlow pads the extra row after: 128 → 64 with a 3×3 stride-2 window pads 0 before.
-        assert_eq!(same(128, 3, 2), (64, 0));
-        assert_eq!(same(128, 5, 2), (64, 1));
-        assert_eq!(same(16, 3, 1), (16, 1));
-        assert_eq!(same(7, 2, 2), (4, 0));
-        assert_eq!(window(1, 4, 2, 2), Ok((2, 0)));
-        assert!(window(1, 1, 2, 2).is_err());
-    }
-
-    #[test]
-    fn asymmetric_conv_padding() {
-        // A 3×3 stride-2 "same" conv on 4×4: pads nothing before, one after.
-        let x: Vec<f32> = (0..16).map(|v| v as f32).collect();
-        let ones = vec![1.0f32; 9];
-        let c = Conv { wt: ones.clone(), b: vec![0.0], inp: 1, out: 1, ks: 3, stride: 2, pad: 0 };
-        let y = c.forward_sized(&x, 4, 4, 2, 2, [0, 0]);
-        // Top-left window rows 0–2, cols 0–2; the bottom-right one is cut by the edge.
-        assert_eq!(y, vec![45.0, 39.0, 66.0, 50.0]);
-        let d = Depthwise { w: ones, b: vec![0.0], c: 1, ks: 3, stride: 2 };
-        assert_eq!(d.forward_sized(&x, 4, 4, 2, 2, [0, 0]), y);
-    }
-
-    #[test]
-    fn pool_pad_and_concat() {
-        let x: Vec<f32> = (0..16).map(|v| v as f32).collect();
-        assert_eq!(max_pool(&x, [4, 4], 1, [2, 2], [2, 2], [2, 2], [0, 0]), vec![5.0, 7.0, 13.0, 15.0]);
-        // Same padding on 3×3 → 2×2: the last window is cut by the edge.
-        let x3: Vec<f32> = (0..9).map(|v| v as f32).collect();
-        assert_eq!(max_pool(&x3, [3, 3], 1, [2, 2], [2, 2], [2, 2], [0, 0]), vec![4.0, 5.0, 7.0, 8.0]);
-        // Channel padding (residual connections widen the channels with zeros).
-        let p = pad(&[1.0, 2.0, 3.0, 4.0], &[1, 1, 2, 2], &[[0, 0], [0, 0], [0, 0], [0, 1]]).unwrap();
-        assert_eq!(p, vec![1.0, 2.0, 0.0, 3.0, 4.0, 0.0]);
-        let p = pad(&[1.0, 2.0], &[1, 2], &[[0, 0], [1, 0]]).unwrap();
-        assert_eq!(p, vec![0.0, 1.0, 2.0]);
-        let a = [1.0, 2.0, 3.0, 4.0];
-        let b = [5.0, 6.0];
-        let (sa, sb) = (vec![1, 2, 2], vec![1, 1, 2]);
-        assert_eq!(concat(&[(&a, &sa), (&b, &sb)], 1).unwrap(), vec![1.0, 2.0, 3.0, 4.0, 5.0, 6.0]);
-        let (sa, sb) = (vec![2, 2], vec![2, 1]);
-        assert_eq!(concat(&[(&a, &sa), (&b, &sb)], 1).unwrap(), vec![1.0, 2.0, 5.0, 3.0, 4.0, 6.0]);
-    }
-
-    #[test]
-    fn damaged_files_are_errors_not_panics() {
-        assert!(Model::read(b"").is_err());
-        assert!(Model::read(&[0xff; 64]).is_err());
-        // Every prefix and a few corruptions of a hand-made buffer.
-        let mut fb = vec![12, 0, 0, 0, 0, 0, 6, 0, 8, 0, 4, 0, 6, 0, 0, 0, 0, 0, 0, 0];
-        for n in 0..fb.len() {
-            let _ = Model::read(&fb[..n]);
-        }
-        for i in 0..fb.len() {
-            fb[i] ^= 0x5a;
-            let _ = Model::read(&fb);
-        }
-    }
-
-    /// A FlatBuffer value, to build small models in tests.
-    enum V {
-        Int(i32),
-        Byte(u8),
-        Table(Vec<(usize, V)>),
-        Ints(Vec<i32>),
-        Bytes(Vec<u8>),
-        Tables(Vec<V>),
-    }
-
-    fn put_u32(b: &mut [u8], at: usize, v: usize) {
-        b[at..at + 4].copy_from_slice(&(v as u32).to_le_bytes());
-    }
-
-    /// Append `v` (children after their parent, so every offset points forward); where it starts.
-    fn put(b: &mut Vec<u8>, v: &V) -> usize {
-        match v {
-            V::Table(fields) => {
-                let slots = fields.iter().map(|f| f.0 + 1).max().unwrap_or(0);
-                let vt = b.len();
-                let vt_len = 4 + 2 * slots;
-                b.resize(vt + vt_len, 0);
-                let t = b.len();
-                // Every field gets 8 bytes (the reader does not need alignment).
-                let t_len = 4 + 8 * fields.len();
-                b.resize(t + t_len, 0);
-                b[vt..vt + 2].copy_from_slice(&(vt_len as u16).to_le_bytes());
-                b[vt + 2..vt + 4].copy_from_slice(&(t_len as u16).to_le_bytes());
-                b[t..t + 4].copy_from_slice(&((t - vt) as i32).to_le_bytes());
-                for (k, (id, f)) in fields.iter().enumerate() {
-                    let at = t + 4 + 8 * k;
-                    b[vt + 4 + 2 * id..vt + 6 + 2 * id].copy_from_slice(&((at - t) as u16).to_le_bytes());
-                    match f {
-                        V::Int(i) => b[at..at + 4].copy_from_slice(&i.to_le_bytes()),
-                        V::Byte(x) => b[at] = *x,
-                        _ => {
-                            let child = put(b, f);
-                            put_u32(b, at, child - at);
-                        }
-                    }
-                }
-                t
-            }
-            V::Ints(xs) => {
-                let p = b.len();
-                b.extend((xs.len() as u32).to_le_bytes());
-                xs.iter().for_each(|x| b.extend(x.to_le_bytes()));
-                p
-            }
-            V::Bytes(xs) => {
-                let p = b.len();
-                b.extend((xs.len() as u32).to_le_bytes());
-                b.extend(xs);
-                p
-            }
-            V::Tables(ts) => {
-                let p = b.len();
-                b.extend((ts.len() as u32).to_le_bytes());
-                let slots = b.len();
-                b.resize(slots + 4 * ts.len(), 0);
-                for (i, t) in ts.iter().enumerate() {
-                    let child = put(b, t);
-                    put_u32(b, slots + 4 * i, child - (slots + 4 * i));
-                }
-                p
-            }
-            V::Int(_) | V::Byte(_) => b.len(),
-        }
-    }
-
-    /// A tensor: shape, type and its constant data (`Some(k)`: buffer `k` of the model's).
-    type T = (Vec<i32>, u8, Option<usize>);
-    /// An operator: code, inputs, outputs and its options' fields.
-    type O = (i32, Vec<i32>, Vec<i32>, Vec<(usize, V)>);
-
-    /// A `.tflite` file with one graph.
-    fn model(bufs: Vec<Vec<u8>>, tensors: Vec<T>, ops: Vec<O>, inputs: Vec<i32>, outputs: Vec<i32>) -> Vec<u8> {
-        let ts = tensors
-            .into_iter()
-            .enumerate()
-            .map(|(i, (shape, ty, buf))| {
-                let mut f = vec![(0, V::Ints(shape)), (1, V::Byte(ty)), (3, V::Bytes(format!("t{i}").into_bytes()))];
-                if let Some(k) = buf {
-                    f.push((2, V::Int(k as i32 + 1)));
-                }
-                V::Table(f)
-            })
-            .collect();
-        let mut codes = vec![];
-        let os = ops
-            .into_iter()
-            .map(|(code, ins, outs, opts)| {
-                let idx = codes.iter().position(|&c| c == code).unwrap_or_else(|| {
-                    codes.push(code);
-                    codes.len() - 1
-                });
-                V::Table(vec![(0, V::Int(idx as i32)), (1, V::Ints(ins)), (2, V::Ints(outs)), (4, V::Table(opts))])
-            })
-            .collect();
-        let g = V::Table(vec![(0, V::Tables(ts)), (1, V::Ints(inputs)), (2, V::Ints(outputs)), (3, V::Tables(os))]);
-        let buffers = std::iter::once(V::Table(vec![])).chain(bufs.into_iter().map(|d| V::Table(vec![(0, V::Bytes(d))]))).collect();
-        let codes = codes.into_iter().map(|c| V::Table(vec![(3, V::Int(c))])).collect();
-        let root = V::Table(vec![(1, V::Tables(codes)), (2, V::Tables(vec![g])), (4, V::Tables(buffers))]);
-        let mut b = vec![0u8; 4];
-        let r = put(&mut b, &root);
-        put_u32(&mut b, 0, r);
-        b
-    }
-
-    fn f32s(xs: &[f32]) -> Vec<u8> {
-        xs.iter().flat_map(|x| x.to_le_bytes()).collect()
-    }
-
-    /// Conv2DOptions / Pool2DOptions: padding (0 same, 1 valid) and stride.
-    fn window_opts(padding: u8, stride: i32) -> Vec<(usize, V)> {
-        vec![(0, V::Byte(padding)), (1, V::Int(stride)), (2, V::Int(stride))]
-    }
-
-    fn refused(bytes: &[u8], why: &str) {
-        let e = Model::read(bytes).err().unwrap_or_default();
-        assert!(e.contains(why), "refused for `{e}`, expected `{why}`");
-    }
-
-    #[test]
-    fn built_models_load_and_run() {
-        // A 3×3 stride-2 "same" conv on 4×4, then a RELU: as `asymmetric_conv_padding`.
-        let m = model(
-            vec![f32s(&[1.0; 9])],
-            vec![(vec![1, 4, 4, 1], FLOAT32, None), (vec![1, 3, 3, 1], FLOAT32, Some(0)), (vec![1, 2, 2, 1], FLOAT32, None), (vec![1, 2, 2, 1], FLOAT32, None)],
-            vec![(op::CONV_2D, vec![0, 1, -1], vec![2], window_opts(0, 2)), (op::RELU, vec![2], vec![3], vec![])],
-            vec![0],
-            vec![3],
-        );
-        let m = Model::read(&m).unwrap();
-        let c = m.cost().unwrap();
-        assert_eq!((c.macs, c.values, c.scratch, c.kernel), (2 * 2 * 9, 8, 2 * 9, 3));
-        // The input, the conv's output and its patch row, alive together.
-        assert_eq!(c.live, 16 + 4 + 2 * 9);
-        let x: Vec<f32> = (0..16).map(|v| v as f32).collect();
-        assert_eq!(m.run(&[&x]).unwrap(), vec![vec![45.0, 39.0, 66.0, 50.0]]);
-    }
-
-    /// #368: an 8 KB model whose CONV_2D needed a 512 GB scratch buffer aborted `run`.
-    #[test]
-    fn convolution_scratch_is_bounded() {
-        let w = 1 << 25;
-        let bomb = model(
-            vec![vec![0; 2 * 64 * 64]],
-            vec![(vec![1, 1, w, 1], FLOAT32, None), (vec![1, 64, 64, 1], FLOAT16, Some(0)), (vec![1, 1, w, 1], FLOAT32, None)],
-            vec![(op::CONV_2D, vec![0, 1, -1], vec![2], window_opts(0, 1))],
-            vec![0],
-            vec![2],
-        );
-        refused(&bomb, "kernel is too large");
-        // A small kernel over many channels: the patch row is `ow·3·3·cin`.
-        let (w, cin) = (1 << 20, 256);
-        let wide = model(
-            vec![vec![0; 2 * 9 * 256]],
-            vec![(vec![1, 1, w, cin], FLOAT32, None), (vec![1, 3, 3, cin], FLOAT16, Some(0)), (vec![1, 1, w, 1], FLOAT32, None)],
-            vec![(op::CONV_2D, vec![0, 1, -1], vec![2], window_opts(0, 1))],
-            vec![0],
-            vec![2],
-        );
-        refused(&wide, "working space is too large");
-    }
-
-    #[test]
-    fn kernel_sides_are_bounded() {
-        let k = MAX_KERNEL as i32 + 1;
-        let conv = model(
-            vec![vec![0; 2 * (k * k) as usize]],
-            vec![(vec![1, 40, 40, 1], FLOAT32, None), (vec![1, k, k, 1], FLOAT16, Some(0)), (vec![1, 40, 40, 1], FLOAT32, None)],
-            vec![(op::CONV_2D, vec![0, 1, -1], vec![2], window_opts(0, 1))],
-            vec![0],
-            vec![2],
-        );
-        refused(&conv, "kernel is too large");
-        let depthwise = model(
-            vec![vec![0; 2 * (k * k) as usize]],
-            vec![(vec![1, 40, 40, 1], FLOAT32, None), (vec![1, k, k, 1], FLOAT16, Some(0)), (vec![1, 40, 40, 1], FLOAT32, None)],
-            vec![(op::DEPTHWISE_CONV_2D, vec![0, 1, -1], vec![2], window_opts(0, 1))],
-            vec![0],
-            vec![2],
-        );
-        refused(&depthwise, "kernel is too large");
-        // A "same" pool takes any window: a huge one looped for billions of steps per output.
-        let mut opts = window_opts(0, 1);
-        opts.extend([(3, V::Int(i32::MAX)), (4, V::Int(i32::MAX))]);
-        let pool = model(
-            vec![],
-            vec![(vec![1, 8, 8, 1], FLOAT32, None), (vec![1, 8, 8, 1], FLOAT32, None)],
-            vec![(op::MAX_POOL_2D, vec![0], vec![1], opts)],
-            vec![0],
-            vec![1],
-        );
-        refused(&pool, "pooling window is too large");
-    }
-
-    #[test]
-    fn multiply_adds_are_bounded() {
-        // Three 16 → 16 pointwise convolutions over 4096×4096: 3·2³² multiply-adds.
-        let s = vec![1, 4096, 4096, 16];
-        let t = |buf| (s.clone(), FLOAT32, buf);
-        let m = model(
-            vec![vec![0; 2 * 16 * 16]],
-            vec![t(None), (vec![16, 1, 1, 16], FLOAT16, Some(0)), t(None), t(None), t(None)],
-            (0..3).map(|i| (op::CONV_2D, vec![if i == 0 { 0 } else { i + 1 }, 1, -1], vec![i + 2], window_opts(0, 1))).collect(),
-            vec![0],
-            vec![4],
-        );
-        refused(&m, "too many multiply-adds");
-    }
-
-    /// #368: 2000 RELUs over 2²⁵ values loaded fine, and one run took minutes.
-    #[test]
-    fn elementwise_work_is_bounded() {
-        let n = 2000;
-        let m = model(
-            vec![],
-            (0..=n).map(|_| (vec![1, 1 << 25], FLOAT32, None)).collect(),
-            (0..n).map(|i| (op::RELU, vec![i], vec![i + 1], vec![])).collect(),
-            vec![0],
-            vec![n],
-        );
-        refused(&m, "too much work");
-    }
-
-    #[test]
-    fn memory_alive_at_once_is_bounded() {
-        // Five outputs of 2²⁷ values each, all kept, besides the input.
-        let m = model(
-            vec![],
-            (0..6).map(|_| (vec![1, 1 << 27], FLOAT32, None)).collect(),
-            (1..6).map(|i| (op::RELU, vec![0], vec![i], vec![])).collect(),
-            vec![0],
-            (1..6).collect(),
-        );
-        refused(&m, "too much memory");
-    }
-
-    #[test]
-    fn shapes_computed_at_run_time_must_match_the_declared_ones() {
-        // PAD to 2³⁰ × 2³⁰ while declaring a 1×1 output.
-        let pads = vec![0, 1 << 30, 0, 1 << 30].into_iter().flat_map(i32::to_le_bytes).collect();
-        let pad = model(
-            vec![pads],
-            vec![(vec![1, 1], FLOAT32, None), (vec![2, 2], INT32, Some(0)), (vec![1, 1], FLOAT32, None)],
-            vec![(op::PAD, vec![0, 1], vec![2], vec![])],
-            vec![0],
-            vec![2],
-        );
-        refused(&pad, "padding disagrees");
-        // Many large parts concatenated into a small declared output.
-        let concat = model(
-            vec![],
-            vec![(vec![1, 1 << 27], FLOAT32, None), (vec![1, 2], FLOAT32, None)],
-            vec![(op::CONCATENATION, vec![0; 64], vec![1], vec![(0, V::Int(1))])],
-            vec![0],
-            vec![1],
-        );
-        refused(&concat, "parts disagree");
-        // A pool whose output claims more channels than its input has.
-        let pool = model(
-            vec![],
-            vec![(vec![1, 2, 2, 1], FLOAT32, None), (vec![1, 1, 1, 1 << 20], FLOAT32, None)],
-            vec![(op::MAX_POOL_2D, vec![0], vec![1], window_opts(1, 2).into_iter().chain([(3, V::Int(2)), (4, V::Int(2))]).collect())],
-            vec![0],
-            vec![1],
-        );
-        refused(&pool, "changes the channels");
-        // Dimensions may not hide behind a zero.
-        let zero = model(vec![], vec![(vec![0, 1 << 30, 1 << 30], FLOAT32, None)], vec![], vec![0], vec![0]);
-        refused(&zero, "tensor is too large");
-    }
-
-    #[test]
-    fn shared_weights_count_once_per_use() {
-        // One 128 KB buffer decoded for 2100 tensors would be 2100 copies of 2¹⁶ floats.
-        let m = model(vec![vec![0; 2 << 16]], (0..2100).map(|_| (vec![1, 1 << 16], FLOAT16, Some(0))).collect(), vec![], vec![], vec![]);
-        refused(&m, "weights are too large");
-    }
-
-    /// The official face models (`EFFECTCRAFT_FACE_LANDMARKER` = path to `face_landmarker.task`)
-    /// fit every budget with wide headroom.
-    #[test]
-    fn official_face_models_fit_the_budgets() {
-        let Some(path) = std::env::var_os("EFFECTCRAFT_FACE_LANDMARKER") else { return };
-        let bytes = std::fs::read(path).unwrap();
-        for name in [crate::mediapipe::DETECTOR, crate::mediapipe::MESH] {
-            let c = Model::read(&crate::pt::zip_file(&bytes, name).unwrap()).unwrap().cost().unwrap();
-            println!("{name}: {c:?}");
-            assert!(c.macs <= MAX_MACS / 8 && c.values <= MAX_VALUES / 8 && c.live <= MAX_LIVE / 8 && c.scratch <= MAX_SCRATCH / 8, "{name}: {c:?}");
-            assert!(c.kernel <= MAX_KERNEL as u64 / 4, "{name}: {c:?}");
-        }
-    }
-}
+mod tests;
diff --git a/crates/segment/src/tflite/tests.rs b/crates/segment/src/tflite/tests.rs
new file mode 100644
index 000000000..29a781d34
--- /dev/null
+++ b/crates/segment/src/tflite/tests.rs
@@ -0,0 +1,356 @@
+use super::*;
+
+#[test]
+fn same_padding_matches_tensorflow() {
+    // TensorFlow pads the extra row after: 128 → 64 with a 3×3 stride-2 window pads 0 before.
+    assert_eq!(same(128, 3, 2), (64, 0));
+    assert_eq!(same(128, 5, 2), (64, 1));
+    assert_eq!(same(16, 3, 1), (16, 1));
+    assert_eq!(same(7, 2, 2), (4, 0));
+    assert_eq!(window(1, 4, 2, 2), Ok((2, 0)));
+    assert!(window(1, 1, 2, 2).is_err());
+}
+
+#[test]
+fn asymmetric_conv_padding() {
+    // A 3×3 stride-2 "same" conv on 4×4: pads nothing before, one after.
+    let x: Vec<f32> = (0..16).map(|v| v as f32).collect();
+    let ones = vec![1.0f32; 9];
+    let c = Conv { wt: ones.clone(), b: vec![0.0], inp: 1, out: 1, ks: 3, stride: 2, pad: 0 };
+    let y = c.forward_sized(&x, 4, 4, 2, 2, [0, 0]);
+    // Top-left window rows 0–2, cols 0–2; the bottom-right one is cut by the edge.
+    assert_eq!(y, vec![45.0, 39.0, 66.0, 50.0]);
+    let d = Depthwise { w: ones, b: vec![0.0], c: 1, ks: 3, stride: 2 };
+    assert_eq!(d.forward_sized(&x, 4, 4, 2, 2, [0, 0]), y);
+}
+
+#[test]
+fn pool_pad_and_concat() {
+    let x: Vec<f32> = (0..16).map(|v| v as f32).collect();
+    assert_eq!(max_pool(&x, [4, 4], 1, [2, 2], [2, 2], [2, 2], [0, 0]), vec![5.0, 7.0, 13.0, 15.0]);
+    // Same padding on 3×3 → 2×2: the last window is cut by the edge.
+    let x3: Vec<f32> = (0..9).map(|v| v as f32).collect();
+    assert_eq!(max_pool(&x3, [3, 3], 1, [2, 2], [2, 2], [2, 2], [0, 0]), vec![4.0, 5.0, 7.0, 8.0]);
+    // Channel padding (residual connections widen the channels with zeros).
+    let p = pad(&[1.0, 2.0, 3.0, 4.0], &[1, 1, 2, 2], &[[0, 0], [0, 0], [0, 0], [0, 1]]).unwrap();
+    assert_eq!(p, vec![1.0, 2.0, 0.0, 3.0, 4.0, 0.0]);
+    let p = pad(&[1.0, 2.0], &[1, 2], &[[0, 0], [1, 0]]).unwrap();
+    assert_eq!(p, vec![0.0, 1.0, 2.0]);
+    let a = [1.0, 2.0, 3.0, 4.0];
+    let b = [5.0, 6.0];
+    let (sa, sb) = (vec![1, 2, 2], vec![1, 1, 2]);
+    assert_eq!(concat(&[(&a, &sa), (&b, &sb)], 1).unwrap(), vec![1.0, 2.0, 3.0, 4.0, 5.0, 6.0]);
+    let (sa, sb) = (vec![2, 2], vec![2, 1]);
+    assert_eq!(concat(&[(&a, &sa), (&b, &sb)], 1).unwrap(), vec![1.0, 2.0, 5.0, 3.0, 4.0, 6.0]);
+}
+
+#[test]
+fn damaged_files_are_errors_not_panics() {
+    assert!(Model::read(b"").is_err());
+    assert!(Model::read(&[0xff; 64]).is_err());
+    // Every prefix and a few corruptions of a hand-made buffer.
+    let mut fb = vec![12, 0, 0, 0, 0, 0, 6, 0, 8, 0, 4, 0, 6, 0, 0, 0, 0, 0, 0, 0];
+    for n in 0..fb.len() {
+        let _ = Model::read(&fb[..n]);
+    }
+    for i in 0..fb.len() {
+        fb[i] ^= 0x5a;
+        let _ = Model::read(&fb);
+    }
+}
+
+/// A FlatBuffer value, to build small models in tests.
+enum V {
+    Int(i32),
+    Byte(u8),
+    Table(Vec<(usize, V)>),
+    Ints(Vec<i32>),
+    Bytes(Vec<u8>),
+    Tables(Vec<V>),
+}
+
+fn put_u32(b: &mut [u8], at: usize, v: usize) {
+    b[at..at + 4].copy_from_slice(&(v as u32).to_le_bytes());
+}
+
+/// Append `v` (children after their parent, so every offset points forward); where it starts.
+fn put(b: &mut Vec<u8>, v: &V) -> usize {
+    match v {
+        V::Table(fields) => {
+            let slots = fields.iter().map(|f| f.0 + 1).max().unwrap_or(0);
+            let vt = b.len();
+            let vt_len = 4 + 2 * slots;
+            b.resize(vt + vt_len, 0);
+            let t = b.len();
+            // Every field gets 8 bytes (the reader does not need alignment).
+            let t_len = 4 + 8 * fields.len();
+            b.resize(t + t_len, 0);
+            b[vt..vt + 2].copy_from_slice(&(vt_len as u16).to_le_bytes());
+            b[vt + 2..vt + 4].copy_from_slice(&(t_len as u16).to_le_bytes());
+            b[t..t + 4].copy_from_slice(&((t - vt) as i32).to_le_bytes());
+            for (k, (id, f)) in fields.iter().enumerate() {
+                let at = t + 4 + 8 * k;
+                b[vt + 4 + 2 * id..vt + 6 + 2 * id].copy_from_slice(&((at - t) as u16).to_le_bytes());
+                match f {
+                    V::Int(i) => b[at..at + 4].copy_from_slice(&i.to_le_bytes()),
+                    V::Byte(x) => b[at] = *x,
+                    _ => {
+                        let child = put(b, f);
+                        put_u32(b, at, child - at);
+                    }
+                }
+            }
+            t
+        }
+        V::Ints(xs) => {
+            let p = b.len();
+            b.extend((xs.len() as u32).to_le_bytes());
+            xs.iter().for_each(|x| b.extend(x.to_le_bytes()));
+            p
+        }
+        V::Bytes(xs) => {
+            let p = b.len();
+            b.extend((xs.len() as u32).to_le_bytes());
+            b.extend(xs);
+            p
+        }
+        V::Tables(ts) => {
+            let p = b.len();
+            b.extend((ts.len() as u32).to_le_bytes());
+            let slots = b.len();
+            b.resize(slots + 4 * ts.len(), 0);
+            for (i, t) in ts.iter().enumerate() {
+                let child = put(b, t);
+                put_u32(b, slots + 4 * i, child - (slots + 4 * i));
+            }
+            p
+        }
+        V::Int(_) | V::Byte(_) => b.len(),
+    }
+}
+
+/// A tensor: shape, type and its constant data (`Some(k)`: buffer `k` of the model's).
+type T = (Vec<i32>, u8, Option<usize>);
+/// An operator: code, inputs, outputs and its options' fields.
+type O = (i32, Vec<i32>, Vec<i32>, Vec<(usize, V)>);
+
+/// A `.tflite` file with one graph.
+fn model(bufs: Vec<Vec<u8>>, tensors: Vec<T>, ops: Vec<O>, inputs: Vec<i32>, outputs: Vec<i32>) -> Vec<u8> {
+    let ts = tensors
+        .into_iter()
+        .enumerate()
+        .map(|(i, (shape, ty, buf))| {
+            let mut f = vec![(0, V::Ints(shape)), (1, V::Byte(ty)), (3, V::Bytes(format!("t{i}").into_bytes()))];
+            if let Some(k) = buf {
+                f.push((2, V::Int(k as i32 + 1)));
+            }
+            V::Table(f)
+        })
+        .collect();
+    let mut codes = vec![];
+    let os = ops
+        .into_iter()
+        .map(|(code, ins, outs, opts)| {
+            let idx = codes.iter().position(|&c| c == code).unwrap_or_else(|| {
+                codes.push(code);
+                codes.len() - 1
+            });
+            V::Table(vec![(0, V::Int(idx as i32)), (1, V::Ints(ins)), (2, V::Ints(outs)), (4, V::Table(opts))])
+        })
+        .collect();
+    let g = V::Table(vec![(0, V::Tables(ts)), (1, V::Ints(inputs)), (2, V::Ints(outputs)), (3, V::Tables(os))]);
+    let buffers = std::iter::once(V::Table(vec![])).chain(bufs.into_iter().map(|d| V::Table(vec![(0, V::Bytes(d))]))).collect();
+    let codes = codes.into_iter().map(|c| V::Table(vec![(3, V::Int(c))])).collect();
+    let root = V::Table(vec![(1, V::Tables(codes)), (2, V::Tables(vec![g])), (4, V::Tables(buffers))]);
+    let mut b = vec![0u8; 4];
+    let r = put(&mut b, &root);
+    put_u32(&mut b, 0, r);
+    b
+}
+
+fn f32s(xs: &[f32]) -> Vec<u8> {
+    xs.iter().flat_map(|x| x.to_le_bytes()).collect()
+}
+
+/// Conv2DOptions / Pool2DOptions: padding (0 same, 1 valid) and stride.
+fn window_opts(padding: u8, stride: i32) -> Vec<(usize, V)> {
+    vec![(0, V::Byte(padding)), (1, V::Int(stride)), (2, V::Int(stride))]
+}
+
+fn refused(bytes: &[u8], why: &str) {
+    let e = Model::read(bytes).err().unwrap_or_default();
+    assert!(e.contains(why), "refused for `{e}`, expected `{why}`");
+}
+
+#[test]
+fn built_models_load_and_run() {
+    // A 3×3 stride-2 "same" conv on 4×4, then a RELU: as `asymmetric_conv_padding`.
+    let m = model(
+        vec![f32s(&[1.0; 9])],
+        vec![(vec![1, 4, 4, 1], FLOAT32, None), (vec![1, 3, 3, 1], FLOAT32, Some(0)), (vec![1, 2, 2, 1], FLOAT32, None), (vec![1, 2, 2, 1], FLOAT32, None)],
+        vec![(op::CONV_2D, vec![0, 1, -1], vec![2], window_opts(0, 2)), (op::RELU, vec![2], vec![3], vec![])],
+        vec![0],
+        vec![3],
+    );
+    let m = Model::read(&m).unwrap();
+    let c = m.cost().unwrap();
+    assert_eq!((c.macs, c.values, c.scratch, c.kernel), (2 * 2 * 9, 8, 2 * 9, 3));
+    // The input, the conv's output and its patch row, alive together.
+    assert_eq!(c.live, 16 + 4 + 2 * 9);
+    let x: Vec<f32> = (0..16).map(|v| v as f32).collect();
+    assert_eq!(m.run(&[&x]).unwrap(), vec![vec![45.0, 39.0, 66.0, 50.0]]);
+}
+
+/// #368: an 8 KB model whose CONV_2D needed a 512 GB scratch buffer aborted `run`.
+#[test]
+fn convolution_scratch_is_bounded() {
+    let w = 1 << 25;
+    let bomb = model(
+        vec![vec![0; 2 * 64 * 64]],
+        vec![(vec![1, 1, w, 1], FLOAT32, None), (vec![1, 64, 64, 1], FLOAT16, Some(0)), (vec![1, 1, w, 1], FLOAT32, None)],
+        vec![(op::CONV_2D, vec![0, 1, -1], vec![2], window_opts(0, 1))],
+        vec![0],
+        vec![2],
+    );
+    refused(&bomb, "kernel is too large");
+    // A small kernel over many channels: the patch row is `ow·3·3·cin`.
+    let (w, cin) = (1 << 20, 256);
+    let wide = model(
+        vec![vec![0; 2 * 9 * 256]],
+        vec![(vec![1, 1, w, cin], FLOAT32, None), (vec![1, 3, 3, cin], FLOAT16, Some(0)), (vec![1, 1, w, 1], FLOAT32, None)],
+        vec![(op::CONV_2D, vec![0, 1, -1], vec![2], window_opts(0, 1))],
+        vec![0],
+        vec![2],
+    );
+    refused(&wide, "working space is too large");
+}
+
+#[test]
+fn kernel_sides_are_bounded() {
+    let k = MAX_KERNEL as i32 + 1;
+    let conv = model(
+        vec![vec![0; 2 * (k * k) as usize]],
+        vec![(vec![1, 40, 40, 1], FLOAT32, None), (vec![1, k, k, 1], FLOAT16, Some(0)), (vec![1, 40, 40, 1], FLOAT32, None)],
+        vec![(op::CONV_2D, vec![0, 1, -1], vec![2], window_opts(0, 1))],
+        vec![0],
+        vec![2],
+    );
+    refused(&conv, "kernel is too large");
+    let depthwise = model(
+        vec![vec![0; 2 * (k * k) as usize]],
+        vec![(vec![1, 40, 40, 1], FLOAT32, None), (vec![1, k, k, 1], FLOAT16, Some(0)), (vec![1, 40, 40, 1], FLOAT32, None)],
+        vec![(op::DEPTHWISE_CONV_2D, vec![0, 1, -1], vec![2], window_opts(0, 1))],
+        vec![0],
+        vec![2],
+    );
+    refused(&depthwise, "kernel is too large");
+    // A "same" pool takes any window: a huge one looped for billions of steps per output.
+    let mut opts = window_opts(0, 1);
+    opts.extend([(3, V::Int(i32::MAX)), (4, V::Int(i32::MAX))]);
+    let pool = model(
+        vec![],
+        vec![(vec![1, 8, 8, 1], FLOAT32, None), (vec![1, 8, 8, 1], FLOAT32, None)],
+        vec![(op::MAX_POOL_2D, vec![0], vec![1], opts)],
+        vec![0],
+        vec![1],
+    );
+    refused(&pool, "pooling window is too large");
+}
+
+#[test]
+fn multiply_adds_are_bounded() {
+    // Three 16 → 16 pointwise convolutions over 4096×4096: 3·2³² multiply-adds.
+    let s = vec![1, 4096, 4096, 16];
+    let t = |buf| (s.clone(), FLOAT32, buf);
+    let m = model(
+        vec![vec![0; 2 * 16 * 16]],
+        vec![t(None), (vec![16, 1, 1, 16], FLOAT16, Some(0)), t(None), t(None), t(None)],
+        (0..3).map(|i| (op::CONV_2D, vec![if i == 0 { 0 } else { i + 1 }, 1, -1], vec![i + 2], window_opts(0, 1))).collect(),
+        vec![0],
+        vec![4],
+    );
+    refused(&m, "too many multiply-adds");
+}
+
+/// #368: 2000 RELUs over 2²⁵ values loaded fine, and one run took minutes.
+#[test]
+fn elementwise_work_is_bounded() {
+    let n = 2000;
+    let m = model(
+        vec![],
+        (0..=n).map(|_| (vec![1, 1 << 25], FLOAT32, None)).collect(),
+        (0..n).map(|i| (op::RELU, vec![i], vec![i + 1], vec![])).collect(),
+        vec![0],
+        vec![n],
+    );
+    refused(&m, "too much work");
+}
+
+#[test]
+fn memory_alive_at_once_is_bounded() {
+    // Five outputs of 2²⁷ values each, all kept, besides the input.
+    let m = model(
+        vec![],
+        (0..6).map(|_| (vec![1, 1 << 27], FLOAT32, None)).collect(),
+        (1..6).map(|i| (op::RELU, vec![0], vec![i], vec![])).collect(),
+        vec![0],
+        (1..6).collect(),
+    );
+    refused(&m, "too much memory");
+}
+
+#[test]
+fn shapes_computed_at_run_time_must_match_the_declared_ones() {
+    // PAD to 2³⁰ × 2³⁰ while declaring a 1×1 output.
+    let pads = vec![0, 1 << 30, 0, 1 << 30].into_iter().flat_map(i32::to_le_bytes).collect();
+    let pad = model(
+        vec![pads],
+        vec![(vec![1, 1], FLOAT32, None), (vec![2, 2], INT32, Some(0)), (vec![1, 1], FLOAT32, None)],
+        vec![(op::PAD, vec![0, 1], vec![2], vec![])],
+        vec![0],
+        vec![2],
+    );
+    refused(&pad, "padding disagrees");
+    // Many large parts concatenated into a small declared output.
+    let concat = model(
+        vec![],
+        vec![(vec![1, 1 << 27], FLOAT32, None), (vec![1, 2], FLOAT32, None)],
+        vec![(op::CONCATENATION, vec![0; 64], vec![1], vec![(0, V::Int(1))])],
+        vec![0],
+        vec![1],
+    );
+    refused(&concat, "parts disagree");
+    // A pool whose output claims more channels than its input has.
+    let pool = model(
+        vec![],
+        vec![(vec![1, 2, 2, 1], FLOAT32, None), (vec![1, 1, 1, 1 << 20], FLOAT32, None)],
+        vec![(op::MAX_POOL_2D, vec![0], vec![1], window_opts(1, 2).into_iter().chain([(3, V::Int(2)), (4, V::Int(2))]).collect())],
+        vec![0],
+        vec![1],
+    );
+    refused(&pool, "changes the channels");
+    // Dimensions may not hide behind a zero.
+    let zero = model(vec![], vec![(vec![0, 1 << 30, 1 << 30], FLOAT32, None)], vec![], vec![0], vec![0]);
+    refused(&zero, "tensor is too large");
+}
+
+#[test]
+fn shared_weights_count_once_per_use() {
+    // One 128 KB buffer decoded for 2100 tensors would be 2100 copies of 2¹⁶ floats.
+    let m = model(vec![vec![0; 2 << 16]], (0..2100).map(|_| (vec![1, 1 << 16], FLOAT16, Some(0))).collect(), vec![], vec![], vec![]);
+    refused(&m, "weights are too large");
+}
+
+/// The official face models (`EFFECTCRAFT_FACE_LANDMARKER` = path to `face_landmarker.task`)
+/// fit every budget with wide headroom.
+#[test]
+fn official_face_models_fit_the_budgets() {
+    let Some(path) = std::env::var_os("EFFECTCRAFT_FACE_LANDMARKER") else { return };
+    let bytes = std::fs::read(path).unwrap();
+    for name in [crate::mediapipe::DETECTOR, crate::mediapipe::MESH] {
+        let c = Model::read(&crate::pt::zip_file(&bytes, name).unwrap()).unwrap().cost().unwrap();
+        println!("{name}: {c:?}");
+        assert!(c.macs <= MAX_MACS / 8 && c.values <= MAX_VALUES / 8 && c.live <= MAX_LIVE / 8 && c.scratch <= MAX_SCRATCH / 8, "{name}: {c:?}");
+        assert!(c.kernel <= MAX_KERNEL as u64 / 4, "{name}: {c:?}");
+    }
+}
diff --git a/crates/svg/src/lib.rs b/crates/svg/src/lib.rs
index fe686dd6b..d2720bb0d 100644
--- a/crates/svg/src/lib.rs
+++ b/crates/svg/src/lib.rs
@@ -510,12 +510,30 @@ fn parse_css(css: &str, sheet: &mut StyleSheet) -> Result<(), Error> {
     let mut rest = css.as_str();
     while let Some(open) = rest.find('{') {
         let sel = rest[..open].trim();
+        if sel.starts_with('@') {
+            // Skip the whole at-rule block, matching nested braces by depth.
+            let mut depth = 0usize;
+            let mut end = None;
+            for (i, c) in rest[open..].char_indices() {
+                match c {
+                    '{' => depth = depth.saturating_add(1),
+                    '}' => {
+                        depth = depth.saturating_sub(1);
+                        if depth == 0 {
+                            end = Some(open + i + 1);
+                            break;
+                        }
+                    }
+                    _ => {}
+                }
+            }
+            let Some(end) = end else { break };
+            rest = &rest[end..];
+            continue;
+        }
         let Some(close) = rest[open..].find('}') else { break };
         let body = &rest[open + 1..open + close];
         rest = &rest[open + close + 1..];
-        if sel.starts_with('@') {
-            continue;
-        }
         let mut decls = parse_decls(body);
         sheet.decls = sheet.decls.saturating_add(decls.len());
         if sheet.decls > MAX_CSS_DECLARATIONS {
diff --git a/crates/svg/src/tests.rs b/crates/svg/src/tests.rs
index 466c9053e..31c95e62f 100644
--- a/crates/svg/src/tests.rs
+++ b/crates/svg/src/tests.rs
@@ -422,3 +422,15 @@ fn font_size_percentage_resolves_against_the_parent_font_size() {
         assert!(matches!(shapes[0].2.geom, Geom::Rect { w, .. } if w == expected), "{body}: {:?}", shapes[0].2.geom);
     }
 }
+
+#[test]
+fn at_rule_blocks_are_skipped_by_brace_depth() {
+    let mut sheet = StyleSheet::default();
+    parse_css("@media print { .a{fill:#ff0000} .b{fill:#0000ff} } .c{fill:red}", &mut sheet).unwrap();
+    assert_eq!(sheet.rules.len(), 1);
+    assert_eq!(sheet.rules[0].classes, vec!["c".to_string()]);
+    let mut sheet = StyleSheet::default();
+    parse_css("@media x { @supports y { .c{} } .d{} } .e{fill:red}", &mut sheet).unwrap();
+    assert_eq!(sheet.rules.len(), 1);
+    assert_eq!(sheet.rules[0].classes, vec!["e".to_string()]);
+}
diff --git a/crates/text/src/fonts.rs b/crates/text/src/fonts.rs
index e20ffcbd1..a973335f4 100644
--- a/crates/text/src/fonts.rs
+++ b/crates/text/src/fonts.rs
@@ -292,15 +292,37 @@ impl Face {
 }
 
 struct Db {
+    fallback: Arc<Face>,
     faces: Vec<Arc<Face>>,
     scanned: bool,
 }
 
+/// Keep the compiled-in regular face available independently of discovery results.
+fn bundled_default_face() -> Arc<Face> {
+    let info =
+        read_faces_bytes(INTER_REGULAR).into_iter().next().map(|n| info_from(n, FaceData::Static(INTER_REGULAR), "bundled")).unwrap_or_else(|| FaceInfo {
+            family: DEFAULT_FAMILY.into(),
+            style: "Regular".into(),
+            weight: 400,
+            italic: false,
+            index: 0,
+            data: FaceData::Static(INTER_REGULAR),
+            origin: "bundled",
+            native_family: None,
+            full_name: "Inter Regular".into(),
+            postscript: Some("Inter-Regular".into()),
+            variable: false,
+            instances: Vec::new(),
+        });
+    Arc::new(Face { id: 0, info, bytes: OnceLock::new(), shaper: OnceLock::new() })
+}
+
 fn db() -> &'static RwLock<Db> {
     static DB: OnceLock<RwLock<Db>> = OnceLock::new();
     DB.get_or_init(|| {
-        let mut db = Db { faces: Vec::new(), scanned: false };
-        for b in [INTER_REGULAR, INTER_MEDIUM, INTER_SEMIBOLD, INTER_BOLD, INTER_ITALIC, JETBRAINS_MONO_REGULAR, NOTO_SERIF_REGULAR] {
+        let fallback = bundled_default_face();
+        let mut db = Db { faces: vec![fallback.clone()], fallback, scanned: false };
+        for b in [INTER_MEDIUM, INTER_SEMIBOLD, INTER_BOLD, INTER_ITALIC, JETBRAINS_MONO_REGULAR, NOTO_SERIF_REGULAR] {
             for n in read_faces_bytes(b) {
                 push(&mut db, info_from(n, FaceData::Static(b), "bundled"));
             }
@@ -394,10 +416,7 @@ pub fn system_scanned() -> bool {
 /// A face by id (panics never: unknown ids give the default face).
 pub fn face(id: FaceId) -> Arc<Face> {
     let d = db().read().unwrap_or_else(std::sync::PoisonError::into_inner);
-    // The bundled fonts are compiled in and always parse (`tests::bundled_families_and_resolution` checks them), so
-    // the database is never empty.
-    #[allow(clippy::expect_used)]
-    d.faces.get(id).or_else(|| d.faces.first()).cloned().expect("bundled fonts present")
+    d.faces.get(id).cloned().unwrap_or_else(|| d.fallback.clone())
 }
 
 /// All faces (bundled first).
@@ -1030,476 +1049,4 @@ fn system_fallback(c: char, style: &str) -> Option<FaceId> {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    /// Concurrent language requests must neither choose another context's font nor reuse its
-    /// cached family order. Synthetic fonts in a child process keep this independent of the host
-    /// font installation and of other tests that exercise the process-global database/locale.
-    #[test]
-    #[cfg(not(target_arch = "wasm32"))]
-    fn cjk_requests_keep_their_language_and_cache_entries() {
-        const CHILD: &str = "EFFECTCRAFT_TEST_ISOLATED_CJK";
-        if std::env::var_os(CHILD).is_none() {
-            let output = std::process::Command::new(std::env::current_exe().unwrap())
-                .args(["--exact", "fonts::tests::cjk_requests_keep_their_language_and_cache_entries", "--nocapture"])
-                .env(CHILD, "1")
-                .output()
-                .unwrap();
-            assert!(output.status.success(), "{}\n{}", String::from_utf8_lossy(&output.stdout), String::from_utf8_lossy(&output.stderr));
-            return;
-        }
-        let families = [("ja", "Yu Gothic"), ("zh-hans", "Microsoft YaHei"), ("zh-hant", "Microsoft JhengHei"), ("ko", "Malgun Gothic")];
-        let mut expected = Vec::new();
-        {
-            let mut d = db().write().unwrap();
-            d.scanned = true; // This test process uses only bundled and synthetic fonts.
-            for (language, family) in families {
-                let mut data = test_font(family);
-                let table = data[12..12 + 8 * 16].as_chunks::<16>().0.iter().find(|t| &t[..4] == b"cmap").unwrap();
-                let cmap = u32::from_be_bytes(table[8..12].try_into().unwrap()) as usize + 12;
-                // Map 页 to the fixture's triangle glyph instead of its private-use range.
-                // All four fonts cover the probe, so coverage cannot choose the right language.
-                for (offset, value) in [(16, '页' as u16), (24, '页' as u16), (30, 2u16.wrapping_sub('页' as u16))] {
-                    data[cmap + offset..cmap + offset + 2].copy_from_slice(&value.to_be_bytes());
-                }
-                let data = Arc::new(data);
-                let names = read_faces_bytes(&data).into_iter().next().unwrap();
-                let id = push(&mut d, info_from(names, FaceData::Shared(data), "test"));
-                expected.push((language, id));
-            }
-        }
-        let base = resolve("Inter", "Regular").face;
-        for &(_, id) in &expected {
-            assert!(face(id).has_char('页'));
-        }
-        // Force the original interleaving: Chinese starts, then Japanese replaces the global
-        // language before Chinese looks up its probe. The explicit request must still win.
-        set_cjk_locale("zh-hans");
-        set_cjk_locale("ja");
-        assert_eq!(fallback_for('页', base), expected[0].1);
-        assert_eq!(fallback_for_locale('页', base, "zh-hans"), expected[1].1);
-        // Do not clear the cache here: different policies must coexist in the same cache.
-        for _ in 0..3 {
-            for &(language, id) in &expected {
-                assert_eq!(fallback_for_locale('页', base, language), id, "{language}");
-            }
-        }
-        let barrier = Arc::new(std::sync::Barrier::new(expected.len()));
-        let threads: Vec<_> = expected
-            .into_iter()
-            .map(|(language, id)| {
-                let barrier = barrier.clone();
-                std::thread::spawn(move || {
-                    barrier.wait();
-                    for _ in 0..128 {
-                        set_cjk_locale(if language == "ja" { "zh-hans" } else { "ja" });
-                        assert_eq!(fallback_for_locale('页', base, language), id, "{language}");
-                    }
-                })
-            })
-            .collect();
-        for thread in threads {
-            thread.join().unwrap();
-        }
-    }
-
-    #[test]
-    fn extra_font_dirs_come_from_a_path_list() {
-        assert!(extra_dirs(None).is_empty());
-        let v = std::env::join_paths(["/a/fonts", "/b/more"]).unwrap_or_default();
-        assert_eq!(extra_dirs(Some(&v)), vec![PathBuf::from("/a/fonts"), PathBuf::from("/b/more")]);
-        assert!(extra_dirs(Some(std::ffi::OsStr::new(""))).is_empty());
-    }
-
-    #[test]
-    fn bundled_families_and_resolution() {
-        let fams = families();
-        let inter = fams.iter().find(|(f, _)| f == "Inter").expect("Inter");
-        for s in ["Regular", "Medium", "SemiBold", "Bold", "Italic"] {
-            assert!(inter.1.iter().any(|x| x == s), "{s} in {:?}", inter.1);
-        }
-        assert!(fams.iter().any(|(f, _)| f == "Noto Serif"));
-        assert!(fams.iter().any(|(f, _)| f == "JetBrains Mono"));
-        let b = resolve("inter", "bold");
-        assert_eq!(face(b.face).info.style, "Bold");
-        assert!(!b.synth_bold);
-        let faces = all_faces();
-        assert!(faces.iter().any(|f| f.info.family == "Noto Serif" && f.info.style == "Regular" && f.info.origin == "bundled"));
-        // A real installed Bold Italic takes priority. Partial installed families can instead
-        // supply the nearest weight/slant, so neither synthesis flag is fixed by the OS.
-        for family in ["Noto Serif", "Inter"] {
-            let resolved = resolve(family, "Bold Italic");
-            let selected = face(resolved.face);
-            assert!(selected.info.family.eq_ignore_ascii_case(family));
-            assert!(!resolved.missing);
-            let candidates: Vec<_> = faces.iter().filter(|f| f.info.family.eq_ignore_ascii_case(family)).collect();
-            if let Some(exact) = candidates.iter().find(|f| f.info.style.eq_ignore_ascii_case("Bold Italic")) {
-                assert_eq!(resolved.face, exact.id, "real style wins for {family}");
-                assert!(!resolved.synth_bold && !resolved.synth_italic);
-            } else {
-                // Italic mismatch dominates any supported font weight distance.
-                let distance = |f: &Face| u32::from(f.info.weight.abs_diff(700)) + if f.info.italic { 0 } else { 1_000 };
-                let nearest = candidates.iter().map(|f| distance(f)).min().unwrap();
-                assert_eq!(distance(&selected), nearest, "closest available style for {family}");
-                assert_eq!(resolved.synth_bold, selected.info.weight <= 500);
-                assert_eq!(resolved.synth_italic, !selected.info.italic);
-            }
-        }
-    }
-
-    #[test]
-    fn missing_family_falls_back_to_inter() {
-        let r = resolve("No Such Font Family 123", "Regular");
-        assert_eq!(face(r.face).info.family, "Inter");
-        assert!(r.missing);
-    }
-
-    /// Native: the system scan reads name tables only and resolves families installed there.
-    #[test]
-    fn system_scan_finds_fonts() {
-        let t = std::time::Instant::now();
-        scan_system(); // (another test may have triggered the scan already)
-        let n = all_faces().iter().filter(|f| f.info.origin == "system").count();
-        eprintln!("system fonts: {n} faces in {:?}", t.elapsed());
-        assert_eq!(scan_system(), 0, "scans once");
-        if cfg!(target_os = "macos") {
-            assert!(n > 20, "{n}");
-            let r = resolve("Helvetica", "Bold");
-            assert_eq!(face(r.face).info.family, "Helvetica");
-            let l = crate::layout_text("Helvetica", &crate::TextStyle { family: "Helvetica".into(), size: 30.0, ..Default::default() }, &Default::default());
-            assert!(!l.missing_font && l.glyphs.iter().all(|g| g.id != 0));
-        }
-    }
-
-    #[test]
-    fn postscript_and_full_names_resolve() {
-        // Bundled Inter: name id 6 is `Inter-Bold`, name id 4 is `Inter Bold`.
-        let ps = resolve("Inter-Bold", "");
-        assert_eq!(face(ps.face).info.style, "Bold");
-        assert!(!ps.missing && !ps.synth_bold);
-        let full = resolve("inter semibold", "");
-        assert_eq!(face(full.face).info.style, "SemiBold");
-        assert!(!full.missing);
-        // A family name still wins over a name lookup.
-        assert_eq!(face(resolve("Inter", "Bold").face).info.style, "Bold");
-    }
-
-    /// #1563: a variable font's named instances are styles of its family. `fontStyle = "Black"`,
-    /// the instance's PostScript name (`font = "Figtree-Black"`) and its full name select the
-    /// instance's axis values instead of the default instance made bold synthetically, and the
-    /// font menus list every instance.
-    #[test]
-    fn variable_named_instances_resolve_and_list() {
-        const FAMILY: &str = "EffectCraft Instance Test";
-        let instances = [
-            ("Light", 300.0, Some("EffectCraftInstanceTest-Light")),
-            ("Regular", 400.0, Some("EffectCraftInstanceTest-Regular")),
-            ("Black", 900.0, Some("EffectCraftInstanceTest-Black")),
-            ("Extra Bold", 800.0, None),
-        ];
-        assert_eq!(add_font_data(crate::sfnt::test_font::variable(FAMILY, &instances, true)).len(), 1);
-        let wght = |r: &Resolved| instance_variations(r);
-        // By style name.
-        let black = resolve(FAMILY, "Black");
-        assert!(!black.missing && !black.synth_bold && !black.synth_italic, "{black:?}");
-        assert_eq!(wght(&black), vec![("wght".to_string(), 900.0)]);
-        assert_eq!(wght(&resolve(FAMILY, "regular")), vec![("wght".to_string(), 400.0)]);
-        // The face's own style is its default instance: no axis values to set.
-        let light = resolve(FAMILY, "Light");
-        assert_eq!((light.face, light.instance), (black.face, None));
-        // A style the family lacks takes the nearest instance's weight, no synthetic bold.
-        let bold = resolve(FAMILY, "Bold");
-        assert!(!bold.synth_bold, "{bold:?}");
-        assert_eq!(wght(&bold), vec![("wght".to_string(), 800.0)]);
-        // By PostScript name, the font's own and the derived one, and by full name.
-        let ps = resolve("EffectCraftInstanceTest-Black", "Regular");
-        assert!(!ps.missing && ps.face == black.face, "{ps:?}");
-        assert_eq!(wght(&ps), vec![("wght".to_string(), 900.0)]);
-        assert_eq!(wght(&resolve("EffectCraftInstanceTest-ExtraBold", "")), vec![("wght".to_string(), 800.0)]);
-        assert_eq!(wght(&resolve("effectcraft instance test extra bold", "")), vec![("wght".to_string(), 800.0)]);
-        // The font menu lists every instance, in weight order.
-        let fams = families();
-        let styles = &fams.iter().find(|(f, _)| f == FAMILY).unwrap().1;
-        assert_eq!(styles, &["Light", "Regular", "Extra Bold", "Black"]);
-        // Static fonts are untouched.
-        assert_eq!(resolve("Inter", "Bold").instance, None);
-    }
-
-    /// Axis values set on the text win over the instance's; the others keep the instance's.
-    #[test]
-    fn explicit_variations_override_the_instance() {
-        let base = vec![("wdth".to_string(), 75.0), ("wght".to_string(), 900.0)];
-        assert_eq!(merge_variations(&base, &[("wght".to_string(), 450.0)]), vec![("wdth".to_string(), 75.0), ("wght".to_string(), 450.0)]);
-        assert_eq!(merge_variations(&base, &[]), base);
-        assert_eq!(merge_variations(&[], &[("opsz".to_string(), 12.0)]), vec![("opsz".to_string(), 12.0)]);
-    }
-
-    #[test]
-    fn scripts_are_classified() {
-        assert_eq!(script_of('あ'), FallbackScript::Japanese);
-        assert_eq!(script_of('ｶ'), FallbackScript::Japanese);
-        assert_eq!(script_of('한'), FallbackScript::Korean);
-        assert_eq!(script_of('水'), FallbackScript::Han);
-        assert_eq!(script_of('、'), FallbackScript::Han);
-        assert_eq!(script_of('Ａ'), FallbackScript::Han);
-        assert_eq!(script_of('\u{20000}'), FallbackScript::Han);
-        assert_eq!(script_of('A'), FallbackScript::Other);
-        assert_eq!(script_of('م'), FallbackScript::Arabic);
-        assert_eq!(script_of('\u{fefb}'), FallbackScript::Arabic);
-        assert_eq!(script_of('\u{5d0}'), FallbackScript::Hebrew);
-        assert_eq!(script_of('क'), FallbackScript::Indic);
-        assert_eq!(script_of('த'), FallbackScript::Indic);
-        assert_eq!(script_of('ก'), FallbackScript::Thai);
-        assert_eq!(script_of('ა'), FallbackScript::Georgian);
-        assert_eq!(script_of('\u{1c90}'), FallbackScript::Georgian, "Mtavruli");
-        assert_eq!(script_of('\u{feff}'), FallbackScript::Other, "the byte order mark is no Arabic letter");
-    }
-
-    /// Native: Arabic, Hebrew, Indic and Thai text in a Latin-only family falls back to the
-    /// platform's plain text family for its script (#394), not to the first installed face that
-    /// covers it (on Windows a calligraphic Arabic face sorts first). Skipped per script where no
-    /// family from its list is installed.
-    #[test]
-    fn other_scripts_fall_back_to_a_plain_system_family() {
-        scan_system();
-        let inter = resolve("Inter", "Regular").face;
-        for (c, families) in [('م', ARABIC_FAMILIES), ('א', HEBREW_FAMILIES), ('क', INDIC_FAMILIES), ('த', INDIC_FAMILIES), ('ก', THAI_FAMILIES)] {
-            let covering = families.iter().any(|n| resolve_in(n, "Regular").is_some_and(|r| face(r.face).has_char(c)));
-            if !covering {
-                eprintln!("{c}: no family from the list is installed; skipping");
-                continue;
-            }
-            let f = face(fallback_for(c, inter));
-            assert!(f.has_char(c), "{c}: {} lacks it", f.info.family);
-            assert!(families.iter().any(|n| f.info.family.eq_ignore_ascii_case(n)), "{c} → {}", f.info.family);
-        }
-    }
-
-    /// Native: Mkhedruli in a Latin-only family falls back to a family from the Georgian list,
-    /// ahead of faces already loaded and of the scan order. Skipped where no family from the list
-    /// is installed.
-    #[test]
-    fn georgian_falls_back_to_a_georgian_system_family() {
-        scan_system();
-        let c = 'ა';
-        if !GEORGIAN_FAMILIES.iter().any(|n| resolve_in(n, "Regular").is_some_and(|r| face(r.face).has_char(c))) {
-            eprintln!("no Georgian family from the list is installed; skipping");
-            return;
-        }
-        let f = face(fallback_for(c, resolve("Inter", "Regular").face));
-        assert!(f.has_char(c), "{} lacks it", f.info.family);
-        assert!(GEORGIAN_FAMILIES.iter().any(|n| f.info.family.eq_ignore_ascii_case(n)), "{c} → {}", f.info.family);
-    }
-
-    /// Native: Japanese text in a Latin-only family falls back to an installed Japanese family
-    /// (whichever the platform ships) instead of the missing-glyph box, without any layer having
-    /// loaded a CJK font first. Skipped where no family from the list is installed.
-    #[test]
-    fn cjk_falls_back_to_a_system_family() {
-        scan_system();
-        let inter = resolve("Inter", "Bold").face;
-        let installed = JAPANESE_FAMILIES.iter().any(|f| resolve_in(f, "Regular").is_some());
-        if !installed {
-            eprintln!("no Japanese family installed; skipping");
-            return;
-        }
-        for c in ['水', 'あ', 'ア', '。'] {
-            let id = fallback_for(c, inter);
-            let f = face(id);
-            assert!(f.has_char(c), "{c}: {} {} lacks it", f.info.family, f.info.style);
-            assert!(JAPANESE_FAMILIES.iter().any(|n| f.info.family.eq_ignore_ascii_case(n)), "{c} → {}", f.info.family);
-        }
-        // The bold cut of the fallback family is chosen for bold text when the family has one.
-        let f = face(fallback_for('水', inter));
-        let (w, _) = style_wants(&f.info.style);
-        let has_bold = all_faces().iter().any(|g| g.info.family == f.info.family && style_wants(&g.info.style).0 >= 600);
-        assert!(!has_bold || w >= 600, "{} {}", f.info.family, f.info.style);
-        // Cached: the second call is a lookup.
-        assert_eq!(fallback_for('水', inter), f.id);
-    }
-
-    /// A minimal TrueType font built in code (no font file in the repo): U+0020 and U+E000 map to
-    /// an empty glyph, U+E001 to a triangle.
-    fn blank_glyph_font() -> Vec<u8> {
-        test_font("Blank Glyph Test")
-    }
-
-    /// The blank-glyph test font under another family name.
-    fn test_font(family: &str) -> Vec<u8> {
-        fn u16s(v: &[u16]) -> Vec<u8> {
-            v.iter().flat_map(|x| x.to_be_bytes()).collect()
-        }
-        let delta_space = 1u16.wrapping_sub(0x20);
-        let cmap4 = {
-            let mut t = u16s(&[4, 0, 0, 6, 4, 1, 2]);
-            t.extend(u16s(&[0x20, 0xE001, 0xFFFF, 0, 0x20, 0xE000, 0xFFFF, delta_space, 0x2001, 1, 0, 0, 0]));
-            let len = t.len() as u16;
-            t[2..4].copy_from_slice(&len.to_be_bytes());
-            t
-        };
-        let mut cmap = u16s(&[0, 1, 3, 1, 0, 12]);
-        cmap.extend(cmap4);
-        // glyph 2: one contour of three on-curve points (100,0) (500,0) (300,600)
-        let mut glyf = u16s(&[1, 100, 0, 500, 600, 2, 0]);
-        glyf.extend([1u8, 1, 1]);
-        glyf.extend(u16s(&[100, 400, (-200i16) as u16, 0, 0, 600]));
-        glyf.push(0);
-        let loca = u16s(&[0, 0, 0, (glyf.len() / 2) as u16]);
-        let mut head = u16s(&[1, 0, 1, 0, 0, 0, 0x5F0F, 0x3CF5, 0, 1000]);
-        head.extend([0u8; 16]);
-        head.extend(u16s(&[100, 0, 500, 600, 0, 8, 2, 0, 0]));
-        let mut hhea = u16s(&[1, 0, 800, (-200i16) as u16, 0, 600, 0, 0, 500, 1, 0, 0]);
-        hhea.extend([0u8; 8]);
-        hhea.extend(u16s(&[0, 3]));
-        let hmtx = u16s(&[600, 0, 600, 0, 600, 0]);
-        let maxp = u16s(&[1, 0, 3, 3, 1, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0]);
-        let strings: Vec<Vec<u8>> = [family, "Regular"].iter().map(|s| s.encode_utf16().flat_map(|u| u.to_be_bytes()).collect()).collect();
-        let mut name = u16s(&[0, 2, 30]);
-        let mut off = 0;
-        for (id, st) in strings.iter().enumerate() {
-            name.extend(u16s(&[3, 1, 0x409, id as u16 + 1, st.len() as u16, off]));
-            off += st.len() as u16;
-        }
-        strings.iter().for_each(|st| name.extend(st));
-        let tables: [(&[u8; 4], Vec<u8>); 8] =
-            [(b"cmap", cmap), (b"glyf", glyf), (b"head", head), (b"hhea", hhea), (b"hmtx", hmtx), (b"loca", loca), (b"maxp", maxp), (b"name", name)];
-        let mut out = u16s(&[1, 0, tables.len() as u16, 128, 3, 0]);
-        let mut offset = 12 + 16 * tables.len();
-        let mut body = vec![];
-        for (tag, data) in &tables {
-            out.extend(*tag);
-            out.extend([0u8; 4]);
-            out.extend((offset as u32).to_be_bytes());
-            out.extend((data.len() as u32).to_be_bytes());
-            let padded = data.len().div_ceil(4) * 4;
-            body.extend(data);
-            body.resize(body.len() + padded - data.len(), 0);
-            offset += padded;
-        }
-        out.extend(body);
-        out
-    }
-
-    /// A face that maps a character to an empty glyph doesn't cover it, so fallback skips it
-    /// (#285); a blank space still counts, and a drawn glyph is found as before.
-    #[test]
-    fn an_empty_glyph_does_not_cover_its_character() {
-        let ids = add_font_data(blank_glyph_font());
-        let &[id] = ids.as_slice() else { panic!("one face expected: {ids:?}") };
-        let f = face(id);
-        assert_eq!(f.info.family, "Blank Glyph Test");
-        assert!(f.glyph('\u{e000}').is_some(), "the cmap maps it");
-        assert!(!f.has_char('\u{e000}'), "but its glyph is empty");
-        assert!(f.has_char('\u{e001}'), "a drawn glyph covers its character");
-        assert!(f.has_char(' '), "a space is blank by nature");
-        let inter = resolve("Inter", "Regular").face;
-        assert_ne!(fallback_for('\u{e000}', inter), id, "fallback never picks the empty glyph");
-        assert_eq!(fallback_for('\u{e001}', inter), id, "fallback finds the drawn one");
-    }
-
-    /// A Microsoft family that isn't installed renders in its installed metric-compatible
-    /// substitute instead of Inter, and still reports itself missing (#1677).
-    #[test]
-    fn microsoft_families_resolve_to_metric_compatible_substitutes() {
-        add_font_data(test_font("Carlito"));
-        add_font_data(test_font("Caladea"));
-        let calibri = resolve("Calibri", "Regular");
-        assert_eq!(face(calibri.face).info.family, "Carlito");
-        assert!(calibri.missing, "the original name stays missing for Find Missing Fonts");
-        let cambria = resolve("Cambria", "Bold");
-        assert_eq!(face(cambria.face).info.family, "Caladea");
-        assert!(cambria.missing);
-        let unknown = resolve("No Such Family 1677", "Regular");
-        assert_eq!(face(unknown.face).info.family, DEFAULT_FAMILY);
-        assert!(unknown.missing);
-    }
-
-    #[test]
-    fn the_han_order_follows_the_cjk_locale() {
-        // Chinese first for any Chinese tag, whether or not it names a script.
-        for tag in ["zh", "zh-CN", "zh_Hans", "ZH-Hant-TW.UTF-8", "zh_MO"] {
-            assert_eq!(han_order_for(tag)[0], FallbackScript::Han, "{tag}");
-        }
-        assert_eq!(han_order_for("ko-KR"), [FallbackScript::Korean, FallbackScript::Japanese, FallbackScript::Han]);
-        // Japanese, and anything else, keeps the Japanese face first for Han text.
-        for tag in ["ja_JP.UTF-8", "en-US", "de", ""] {
-            assert_eq!(han_order_for(tag), [FallbackScript::Japanese, FallbackScript::Han, FallbackScript::Korean], "{tag}");
-        }
-        // The host's request is what `han_order` reads (the ui test covers the effect on the
-        // registered fallbacks; this only checks that clearing it returns to the environment).
-        assert_eq!(requested_cjk_locale(), None, "tests run without a request");
-        assert_eq!(han_order(), han_order_for(&active_cjk_locale()));
-    }
-
-    #[test]
-    fn the_chinese_family_list_follows_the_script_the_locale_asks_for() {
-        for tag in ["zh", "zh-CN", "zh_Hans", "zh_CN.UTF-8", "zh-SG"] {
-            assert_eq!(chinese_families_for(tag), SIMPLIFIED_CHINESE_FAMILIES, "{tag}");
-        }
-        for tag in ["zh-Hant", "zh-Hant-TW", "zh_TW", "zh-HK", "zh_MO.UTF-8"] {
-            assert_eq!(chinese_families_for(tag), TRADITIONAL_CHINESE_FAMILIES, "{tag}");
-        }
-        // Each list carries its own script's faces and not the other's, which is the point of
-        // splitting them: `PingFang SC` covers the same code points as `PingFang TC`, so the
-        // fallback search would have kept it and drawn Simplified forms in a Traditional interface.
-        assert!(SIMPLIFIED_CHINESE_FAMILIES.iter().any(|f| f.contains("PingFang SC") && !f.contains("Source")));
-        assert!(!SIMPLIFIED_CHINESE_FAMILIES.iter().any(|f| f.contains("TC") || f.contains("JhengHei")));
-        assert!(TRADITIONAL_CHINESE_FAMILIES.iter().any(|f| f.contains("PingFang TC")));
-        assert!(!TRADITIONAL_CHINESE_FAMILIES.iter().any(|f| f.contains(" SC") || f.contains("YaHei") || f.contains("WenQuanYi")));
-        assert!(TRADITIONAL_CHINESE_FAMILIES.iter().any(|f| f.contains("Heiti TC") || f.contains("Hiragino Sans CNS")));
-        // The arm the fallback itself walks: Han hands over the list the locale's script picked.
-        assert_eq!(families_for(FallbackScript::Han, CjkLocale::from_tag(&active_cjk_locale())), chinese_families_for(&active_cjk_locale()));
-        // Han text is the only thing these lists serve; the Japanese order does not change.
-        assert_eq!(han_order_for("ja_JP.UTF-8")[0], FallbackScript::Japanese);
-    }
-
-    #[test]
-    fn the_rendered_order_keeps_the_print_face_first() {
-        // A composed frame renders with these lists, so they keep the platform's print order: the
-        // interface prefers the platform's UI faces on its own (see `install_script_fallbacks` in
-        // the ui crate), and an existing project must not render differently because a window's
-        // chrome changed.
-        let pos = |list: &[&str], name: &str| list.iter().position(|f| *f == name).unwrap_or(usize::MAX);
-        assert!(
-            pos(JAPANESE_FAMILIES, "Yu Gothic") < pos(JAPANESE_FAMILIES, "Yu Gothic UI"),
-            "the print face must come before its UI sibling: {JAPANESE_FAMILIES:?}"
-        );
-        for name in ["Meiryo UI", "MS UI Gothic"] {
-            assert!(!JAPANESE_FAMILIES.contains(&name), "{name} belongs to the interface order, not this list");
-        }
-        assert_eq!(SIMPLIFIED_CHINESE_FAMILIES[0], "Microsoft YaHei");
-        assert_eq!(TRADITIONAL_CHINESE_FAMILIES[0], "Microsoft JhengHei");
-        for name in ["Microsoft YaHei UI", "Microsoft JhengHei UI", "PMingLiU"] {
-            assert!(
-                !SIMPLIFIED_CHINESE_FAMILIES.contains(&name) && !TRADITIONAL_CHINESE_FAMILIES.contains(&name),
-                "{name} belongs to the interface order, not these lists"
-            );
-        }
-    }
-
-    #[test]
-    fn bundled_ui_fonts_cover_the_ukrainian_alphabet() {
-        const ALPHABET: &str = "АБВГҐДЕЄЖЗИІЇЙКЛМНОПРСТУФХЦЧШЩЬЮЯабвгґдеєжзиіїйклмнопрстуфхцчшщьюя’«»";
-        for (name, bytes) in
-            [("Inter Regular", INTER_REGULAR), ("Inter Medium", INTER_MEDIUM), ("Inter SemiBold", INTER_SEMIBOLD), ("JetBrains Mono", JETBRAINS_MONO_REGULAR)]
-        {
-            let font = FontRef::new(bytes).unwrap();
-            for c in ALPHABET.chars() {
-                assert!(covers(&font, c), "{name} cannot draw {c}");
-            }
-        }
-    }
-
-    #[test]
-    fn metrics_and_coverage() {
-        let f = face(resolve("Inter", "Regular").face);
-        let m = f.metrics(100.0);
-        assert!(m.ascent > 80.0 && m.ascent < 110.0, "{m:?}");
-        assert!(m.descent > 10.0 && m.descent < 40.0);
-        assert!(m.cap_height > 60.0 && m.cap_height < 80.0);
-        assert!(f.has_char('A') && f.has_char('Ж'));
-        assert!(!f.has_char('\u{5d0}'), "Inter has no Hebrew");
-        assert!(f.has_feature(b"liga") || f.has_feature(b"calt"));
-    }
-}
+mod tests;
diff --git a/crates/text/src/fonts/tests.rs b/crates/text/src/fonts/tests.rs
new file mode 100644
index 000000000..079a001e0
--- /dev/null
+++ b/crates/text/src/fonts/tests.rs
@@ -0,0 +1,480 @@
+use super::*;
+
+/// Concurrent language requests must neither choose another context's font nor reuse its
+/// cached family order. Synthetic fonts in a child process keep this independent of the host
+/// font installation and of other tests that exercise the process-global database/locale.
+#[test]
+#[cfg(not(target_arch = "wasm32"))]
+fn cjk_requests_keep_their_language_and_cache_entries() {
+    const CHILD: &str = "EFFECTCRAFT_TEST_ISOLATED_CJK";
+    if std::env::var_os(CHILD).is_none() {
+        let output = std::process::Command::new(std::env::current_exe().unwrap())
+            .args(["--exact", "fonts::tests::cjk_requests_keep_their_language_and_cache_entries", "--nocapture"])
+            .env(CHILD, "1")
+            .output()
+            .unwrap();
+        assert!(output.status.success(), "{}\n{}", String::from_utf8_lossy(&output.stdout), String::from_utf8_lossy(&output.stderr));
+        return;
+    }
+    let families = [("ja", "Yu Gothic"), ("zh-hans", "Microsoft YaHei"), ("zh-hant", "Microsoft JhengHei"), ("ko", "Malgun Gothic")];
+    let mut expected = Vec::new();
+    {
+        let mut d = db().write().unwrap();
+        d.scanned = true; // This test process uses only bundled and synthetic fonts.
+        for (language, family) in families {
+            let mut data = test_font(family);
+            let table = data[12..12 + 8 * 16].as_chunks::<16>().0.iter().find(|t| &t[..4] == b"cmap").unwrap();
+            let cmap = u32::from_be_bytes(table[8..12].try_into().unwrap()) as usize + 12;
+            // Map 页 to the fixture's triangle glyph instead of its private-use range.
+            // All four fonts cover the probe, so coverage cannot choose the right language.
+            for (offset, value) in [(16, '页' as u16), (24, '页' as u16), (30, 2u16.wrapping_sub('页' as u16))] {
+                data[cmap + offset..cmap + offset + 2].copy_from_slice(&value.to_be_bytes());
+            }
+            let data = Arc::new(data);
+            let names = read_faces_bytes(&data).into_iter().next().unwrap();
+            let id = push(&mut d, info_from(names, FaceData::Shared(data), "test"));
+            expected.push((language, id));
+        }
+    }
+    let base = resolve("Inter", "Regular").face;
+    for &(_, id) in &expected {
+        assert!(face(id).has_char('页'));
+    }
+    // Force the original interleaving: Chinese starts, then Japanese replaces the global
+    // language before Chinese looks up its probe. The explicit request must still win.
+    set_cjk_locale("zh-hans");
+    set_cjk_locale("ja");
+    assert_eq!(fallback_for('页', base), expected[0].1);
+    assert_eq!(fallback_for_locale('页', base, "zh-hans"), expected[1].1);
+    // Do not clear the cache here: different policies must coexist in the same cache.
+    for _ in 0..3 {
+        for &(language, id) in &expected {
+            assert_eq!(fallback_for_locale('页', base, language), id, "{language}");
+        }
+    }
+    let barrier = Arc::new(std::sync::Barrier::new(expected.len()));
+    let threads: Vec<_> = expected
+        .into_iter()
+        .map(|(language, id)| {
+            let barrier = barrier.clone();
+            std::thread::spawn(move || {
+                barrier.wait();
+                for _ in 0..128 {
+                    set_cjk_locale(if language == "ja" { "zh-hans" } else { "ja" });
+                    assert_eq!(fallback_for_locale('页', base, language), id, "{language}");
+                }
+            })
+        })
+        .collect();
+    for thread in threads {
+        thread.join().unwrap();
+    }
+}
+
+#[test]
+fn extra_font_dirs_come_from_a_path_list() {
+    assert!(extra_dirs(None).is_empty());
+    let v = std::env::join_paths(["/a/fonts", "/b/more"]).unwrap_or_default();
+    assert_eq!(extra_dirs(Some(&v)), vec![PathBuf::from("/a/fonts"), PathBuf::from("/b/more")]);
+    assert!(extra_dirs(Some(std::ffi::OsStr::new(""))).is_empty());
+}
+
+#[test]
+fn bundled_families_and_resolution() {
+    let fams = families();
+    let inter = fams.iter().find(|(f, _)| f == "Inter").expect("Inter");
+    for s in ["Regular", "Medium", "SemiBold", "Bold", "Italic"] {
+        assert!(inter.1.iter().any(|x| x == s), "{s} in {:?}", inter.1);
+    }
+    assert!(fams.iter().any(|(f, _)| f == "Noto Serif"));
+    assert!(fams.iter().any(|(f, _)| f == "JetBrains Mono"));
+    let b = resolve("inter", "bold");
+    assert_eq!(face(b.face).info.style, "Bold");
+    assert!(!b.synth_bold);
+    let faces = all_faces();
+    assert!(faces.iter().any(|f| f.info.family == "Noto Serif" && f.info.style == "Regular" && f.info.origin == "bundled"));
+    // A real installed Bold Italic takes priority. Partial installed families can instead
+    // supply the nearest weight/slant, so neither synthesis flag is fixed by the OS.
+    for family in ["Noto Serif", "Inter"] {
+        let resolved = resolve(family, "Bold Italic");
+        let selected = face(resolved.face);
+        assert!(selected.info.family.eq_ignore_ascii_case(family));
+        assert!(!resolved.missing);
+        let candidates: Vec<_> = faces.iter().filter(|f| f.info.family.eq_ignore_ascii_case(family)).collect();
+        if let Some(exact) = candidates.iter().find(|f| f.info.style.eq_ignore_ascii_case("Bold Italic")) {
+            assert_eq!(resolved.face, exact.id, "real style wins for {family}");
+            assert!(!resolved.synth_bold && !resolved.synth_italic);
+        } else {
+            // Italic mismatch dominates any supported font weight distance.
+            let distance = |f: &Face| u32::from(f.info.weight.abs_diff(700)) + if f.info.italic { 0 } else { 1_000 };
+            let nearest = candidates.iter().map(|f| distance(f)).min().unwrap();
+            assert_eq!(distance(&selected), nearest, "closest available style for {family}");
+            assert_eq!(resolved.synth_bold, selected.info.weight <= 500);
+            assert_eq!(resolved.synth_italic, !selected.info.italic);
+        }
+    }
+}
+
+#[test]
+fn missing_family_falls_back_to_inter() {
+    let r = resolve("No Such Font Family 123", "Regular");
+    assert_eq!(face(r.face).info.family, "Inter");
+    assert!(r.missing);
+}
+
+/// Native: the system scan reads name tables only and resolves families installed there.
+#[test]
+fn system_scan_finds_fonts() {
+    let t = std::time::Instant::now();
+    scan_system(); // (another test may have triggered the scan already)
+    let n = all_faces().iter().filter(|f| f.info.origin == "system").count();
+    eprintln!("system fonts: {n} faces in {:?}", t.elapsed());
+    assert_eq!(scan_system(), 0, "scans once");
+    if cfg!(target_os = "macos") {
+        assert!(n > 20, "{n}");
+        let r = resolve("Helvetica", "Bold");
+        assert_eq!(face(r.face).info.family, "Helvetica");
+        let l = crate::layout_text("Helvetica", &crate::TextStyle { family: "Helvetica".into(), size: 30.0, ..Default::default() }, &Default::default());
+        assert!(!l.missing_font && l.glyphs.iter().all(|g| g.id != 0));
+    }
+}
+
+#[test]
+fn postscript_and_full_names_resolve() {
+    // Bundled Inter: name id 6 is `Inter-Bold`, name id 4 is `Inter Bold`.
+    let ps = resolve("Inter-Bold", "");
+    assert_eq!(face(ps.face).info.style, "Bold");
+    assert!(!ps.missing && !ps.synth_bold);
+    let full = resolve("inter semibold", "");
+    assert_eq!(face(full.face).info.style, "SemiBold");
+    assert!(!full.missing);
+    // A family name still wins over a name lookup.
+    assert_eq!(face(resolve("Inter", "Bold").face).info.style, "Bold");
+}
+
+/// #1563: a variable font's named instances are styles of its family. `fontStyle = "Black"`,
+/// the instance's PostScript name (`font = "Figtree-Black"`) and its full name select the
+/// instance's axis values instead of the default instance made bold synthetically, and the
+/// font menus list every instance.
+#[test]
+fn variable_named_instances_resolve_and_list() {
+    const FAMILY: &str = "EffectCraft Instance Test";
+    let instances = [
+        ("Light", 300.0, Some("EffectCraftInstanceTest-Light")),
+        ("Regular", 400.0, Some("EffectCraftInstanceTest-Regular")),
+        ("Black", 900.0, Some("EffectCraftInstanceTest-Black")),
+        ("Extra Bold", 800.0, None),
+    ];
+    assert_eq!(add_font_data(crate::sfnt::test_font::variable(FAMILY, &instances, true)).len(), 1);
+    let wght = |r: &Resolved| instance_variations(r);
+    // By style name.
+    let black = resolve(FAMILY, "Black");
+    assert!(!black.missing && !black.synth_bold && !black.synth_italic, "{black:?}");
+    assert_eq!(wght(&black), vec![("wght".to_string(), 900.0)]);
+    assert_eq!(wght(&resolve(FAMILY, "regular")), vec![("wght".to_string(), 400.0)]);
+    // The face's own style is its default instance: no axis values to set.
+    let light = resolve(FAMILY, "Light");
+    assert_eq!((light.face, light.instance), (black.face, None));
+    // A style the family lacks takes the nearest instance's weight, no synthetic bold.
+    let bold = resolve(FAMILY, "Bold");
+    assert!(!bold.synth_bold, "{bold:?}");
+    assert_eq!(wght(&bold), vec![("wght".to_string(), 800.0)]);
+    // By PostScript name, the font's own and the derived one, and by full name.
+    let ps = resolve("EffectCraftInstanceTest-Black", "Regular");
+    assert!(!ps.missing && ps.face == black.face, "{ps:?}");
+    assert_eq!(wght(&ps), vec![("wght".to_string(), 900.0)]);
+    assert_eq!(wght(&resolve("EffectCraftInstanceTest-ExtraBold", "")), vec![("wght".to_string(), 800.0)]);
+    assert_eq!(wght(&resolve("effectcraft instance test extra bold", "")), vec![("wght".to_string(), 800.0)]);
+    // The font menu lists every instance, in weight order.
+    let fams = families();
+    let styles = &fams.iter().find(|(f, _)| f == FAMILY).unwrap().1;
+    assert_eq!(styles, &["Light", "Regular", "Extra Bold", "Black"]);
+    // Static fonts are untouched.
+    assert_eq!(resolve("Inter", "Bold").instance, None);
+}
+
+/// Axis values set on the text win over the instance's; the others keep the instance's.
+#[test]
+fn explicit_variations_override_the_instance() {
+    let base = vec![("wdth".to_string(), 75.0), ("wght".to_string(), 900.0)];
+    assert_eq!(merge_variations(&base, &[("wght".to_string(), 450.0)]), vec![("wdth".to_string(), 75.0), ("wght".to_string(), 450.0)]);
+    assert_eq!(merge_variations(&base, &[]), base);
+    assert_eq!(merge_variations(&[], &[("opsz".to_string(), 12.0)]), vec![("opsz".to_string(), 12.0)]);
+}
+
+#[test]
+fn scripts_are_classified() {
+    assert_eq!(script_of('あ'), FallbackScript::Japanese);
+    assert_eq!(script_of('ｶ'), FallbackScript::Japanese);
+    assert_eq!(script_of('한'), FallbackScript::Korean);
+    assert_eq!(script_of('水'), FallbackScript::Han);
+    assert_eq!(script_of('、'), FallbackScript::Han);
+    assert_eq!(script_of('Ａ'), FallbackScript::Han);
+    assert_eq!(script_of('\u{20000}'), FallbackScript::Han);
+    assert_eq!(script_of('A'), FallbackScript::Other);
+    assert_eq!(script_of('م'), FallbackScript::Arabic);
+    assert_eq!(script_of('\u{fefb}'), FallbackScript::Arabic);
+    assert_eq!(script_of('\u{5d0}'), FallbackScript::Hebrew);
+    assert_eq!(script_of('क'), FallbackScript::Indic);
+    assert_eq!(script_of('த'), FallbackScript::Indic);
+    assert_eq!(script_of('ก'), FallbackScript::Thai);
+    assert_eq!(script_of('ა'), FallbackScript::Georgian);
+    assert_eq!(script_of('\u{1c90}'), FallbackScript::Georgian, "Mtavruli");
+    assert_eq!(script_of('\u{feff}'), FallbackScript::Other, "the byte order mark is no Arabic letter");
+}
+
+/// Native: Arabic, Hebrew, Indic and Thai text in a Latin-only family falls back to the
+/// platform's plain text family for its script (#394), not to the first installed face that
+/// covers it (on Windows a calligraphic Arabic face sorts first). Skipped per script where no
+/// family from its list is installed.
+#[test]
+fn other_scripts_fall_back_to_a_plain_system_family() {
+    scan_system();
+    let inter = resolve("Inter", "Regular").face;
+    for (c, families) in [('م', ARABIC_FAMILIES), ('א', HEBREW_FAMILIES), ('क', INDIC_FAMILIES), ('த', INDIC_FAMILIES), ('ก', THAI_FAMILIES)] {
+        let covering = families.iter().any(|n| resolve_in(n, "Regular").is_some_and(|r| face(r.face).has_char(c)));
+        if !covering {
+            eprintln!("{c}: no family from the list is installed; skipping");
+            continue;
+        }
+        let f = face(fallback_for(c, inter));
+        assert!(f.has_char(c), "{c}: {} lacks it", f.info.family);
+        assert!(families.iter().any(|n| f.info.family.eq_ignore_ascii_case(n)), "{c} → {}", f.info.family);
+    }
+}
+
+/// Native: Mkhedruli in a Latin-only family falls back to a family from the Georgian list,
+/// ahead of faces already loaded and of the scan order. Skipped where no family from the list
+/// is installed.
+#[test]
+fn georgian_falls_back_to_a_georgian_system_family() {
+    scan_system();
+    let c = 'ა';
+    if !GEORGIAN_FAMILIES.iter().any(|n| resolve_in(n, "Regular").is_some_and(|r| face(r.face).has_char(c))) {
+        eprintln!("no Georgian family from the list is installed; skipping");
+        return;
+    }
+    let f = face(fallback_for(c, resolve("Inter", "Regular").face));
+    assert!(f.has_char(c), "{} lacks it", f.info.family);
+    assert!(GEORGIAN_FAMILIES.iter().any(|n| f.info.family.eq_ignore_ascii_case(n)), "{c} → {}", f.info.family);
+}
+
+/// Native: Japanese text in a Latin-only family falls back to an installed Japanese family
+/// (whichever the platform ships) instead of the missing-glyph box, without any layer having
+/// loaded a CJK font first. Skipped where no family from the list is installed.
+#[test]
+fn cjk_falls_back_to_a_system_family() {
+    scan_system();
+    let inter = resolve("Inter", "Bold").face;
+    let installed = JAPANESE_FAMILIES.iter().any(|f| resolve_in(f, "Regular").is_some());
+    if !installed {
+        eprintln!("no Japanese family installed; skipping");
+        return;
+    }
+    for c in ['水', 'あ', 'ア', '。'] {
+        let id = fallback_for(c, inter);
+        let f = face(id);
+        assert!(f.has_char(c), "{c}: {} {} lacks it", f.info.family, f.info.style);
+        assert!(JAPANESE_FAMILIES.iter().any(|n| f.info.family.eq_ignore_ascii_case(n)), "{c} → {}", f.info.family);
+    }
+    // The bold cut of the fallback family is chosen for bold text when the family has one.
+    let f = face(fallback_for('水', inter));
+    let (w, _) = style_wants(&f.info.style);
+    let has_bold = all_faces().iter().any(|g| g.info.family == f.info.family && style_wants(&g.info.style).0 >= 600);
+    assert!(!has_bold || w >= 600, "{} {}", f.info.family, f.info.style);
+    // Cached: the second call is a lookup.
+    assert_eq!(fallback_for('水', inter), f.id);
+}
+
+/// A minimal TrueType font built in code (no font file in the repo): U+0020 and U+E000 map to
+/// an empty glyph, U+E001 to a triangle.
+fn blank_glyph_font() -> Vec<u8> {
+    test_font("Blank Glyph Test")
+}
+
+/// The blank-glyph test font under another family name.
+fn test_font(family: &str) -> Vec<u8> {
+    fn u16s(v: &[u16]) -> Vec<u8> {
+        v.iter().flat_map(|x| x.to_be_bytes()).collect()
+    }
+    let delta_space = 1u16.wrapping_sub(0x20);
+    let cmap4 = {
+        let mut t = u16s(&[4, 0, 0, 6, 4, 1, 2]);
+        t.extend(u16s(&[0x20, 0xE001, 0xFFFF, 0, 0x20, 0xE000, 0xFFFF, delta_space, 0x2001, 1, 0, 0, 0]));
+        let len = t.len() as u16;
+        t[2..4].copy_from_slice(&len.to_be_bytes());
+        t
+    };
+    let mut cmap = u16s(&[0, 1, 3, 1, 0, 12]);
+    cmap.extend(cmap4);
+    // glyph 2: one contour of three on-curve points (100,0) (500,0) (300,600)
+    let mut glyf = u16s(&[1, 100, 0, 500, 600, 2, 0]);
+    glyf.extend([1u8, 1, 1]);
+    glyf.extend(u16s(&[100, 400, (-200i16) as u16, 0, 0, 600]));
+    glyf.push(0);
+    let loca = u16s(&[0, 0, 0, (glyf.len() / 2) as u16]);
+    let mut head = u16s(&[1, 0, 1, 0, 0, 0, 0x5F0F, 0x3CF5, 0, 1000]);
+    head.extend([0u8; 16]);
+    head.extend(u16s(&[100, 0, 500, 600, 0, 8, 2, 0, 0]));
+    let mut hhea = u16s(&[1, 0, 800, (-200i16) as u16, 0, 600, 0, 0, 500, 1, 0, 0]);
+    hhea.extend([0u8; 8]);
+    hhea.extend(u16s(&[0, 3]));
+    let hmtx = u16s(&[600, 0, 600, 0, 600, 0]);
+    let maxp = u16s(&[1, 0, 3, 3, 1, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0]);
+    let strings: Vec<Vec<u8>> = [family, "Regular"].iter().map(|s| s.encode_utf16().flat_map(|u| u.to_be_bytes()).collect()).collect();
+    let mut name = u16s(&[0, 2, 30]);
+    let mut off = 0;
+    for (id, st) in strings.iter().enumerate() {
+        name.extend(u16s(&[3, 1, 0x409, id as u16 + 1, st.len() as u16, off]));
+        off += st.len() as u16;
+    }
+    strings.iter().for_each(|st| name.extend(st));
+    let tables: [(&[u8; 4], Vec<u8>); 8] =
+        [(b"cmap", cmap), (b"glyf", glyf), (b"head", head), (b"hhea", hhea), (b"hmtx", hmtx), (b"loca", loca), (b"maxp", maxp), (b"name", name)];
+    let mut out = u16s(&[1, 0, tables.len() as u16, 128, 3, 0]);
+    let mut offset = 12 + 16 * tables.len();
+    let mut body = vec![];
+    for (tag, data) in &tables {
+        out.extend(*tag);
+        out.extend([0u8; 4]);
+        out.extend((offset as u32).to_be_bytes());
+        out.extend((data.len() as u32).to_be_bytes());
+        let padded = data.len().div_ceil(4) * 4;
+        body.extend(data);
+        body.resize(body.len() + padded - data.len(), 0);
+        offset += padded;
+    }
+    out.extend(body);
+    out
+}
+
+/// A face that maps a character to an empty glyph doesn't cover it, so fallback skips it
+/// (#285); a blank space still counts, and a drawn glyph is found as before.
+#[test]
+fn an_empty_glyph_does_not_cover_its_character() {
+    let ids = add_font_data(blank_glyph_font());
+    let &[id] = ids.as_slice() else { panic!("one face expected: {ids:?}") };
+    let f = face(id);
+    assert_eq!(f.info.family, "Blank Glyph Test");
+    assert!(f.glyph('\u{e000}').is_some(), "the cmap maps it");
+    assert!(!f.has_char('\u{e000}'), "but its glyph is empty");
+    assert!(f.has_char('\u{e001}'), "a drawn glyph covers its character");
+    assert!(f.has_char(' '), "a space is blank by nature");
+    let inter = resolve("Inter", "Regular").face;
+    assert_ne!(fallback_for('\u{e000}', inter), id, "fallback never picks the empty glyph");
+    assert_eq!(fallback_for('\u{e001}', inter), id, "fallback finds the drawn one");
+}
+
+/// A Microsoft family that isn't installed renders in its installed metric-compatible
+/// substitute instead of Inter, and still reports itself missing (#1677).
+#[test]
+fn microsoft_families_resolve_to_metric_compatible_substitutes() {
+    add_font_data(test_font("Carlito"));
+    add_font_data(test_font("Caladea"));
+    let calibri = resolve("Calibri", "Regular");
+    assert_eq!(face(calibri.face).info.family, "Carlito");
+    assert!(calibri.missing, "the original name stays missing for Find Missing Fonts");
+    let cambria = resolve("Cambria", "Bold");
+    assert_eq!(face(cambria.face).info.family, "Caladea");
+    assert!(cambria.missing);
+    let unknown = resolve("No Such Family 1677", "Regular");
+    assert_eq!(face(unknown.face).info.family, DEFAULT_FAMILY);
+    assert!(unknown.missing);
+}
+
+#[test]
+fn the_han_order_follows_the_cjk_locale() {
+    // Chinese first for any Chinese tag, whether or not it names a script.
+    for tag in ["zh", "zh-CN", "zh_Hans", "ZH-Hant-TW.UTF-8", "zh_MO"] {
+        assert_eq!(han_order_for(tag)[0], FallbackScript::Han, "{tag}");
+    }
+    assert_eq!(han_order_for("ko-KR"), [FallbackScript::Korean, FallbackScript::Japanese, FallbackScript::Han]);
+    // Japanese, and anything else, keeps the Japanese face first for Han text.
+    for tag in ["ja_JP.UTF-8", "en-US", "de", ""] {
+        assert_eq!(han_order_for(tag), [FallbackScript::Japanese, FallbackScript::Han, FallbackScript::Korean], "{tag}");
+    }
+    // The host's request is what `han_order` reads (the ui test covers the effect on the
+    // registered fallbacks; this only checks that clearing it returns to the environment).
+    assert_eq!(requested_cjk_locale(), None, "tests run without a request");
+    assert_eq!(han_order(), han_order_for(&active_cjk_locale()));
+}
+
+#[test]
+fn the_chinese_family_list_follows_the_script_the_locale_asks_for() {
+    for tag in ["zh", "zh-CN", "zh_Hans", "zh_CN.UTF-8", "zh-SG"] {
+        assert_eq!(chinese_families_for(tag), SIMPLIFIED_CHINESE_FAMILIES, "{tag}");
+    }
+    for tag in ["zh-Hant", "zh-Hant-TW", "zh_TW", "zh-HK", "zh_MO.UTF-8"] {
+        assert_eq!(chinese_families_for(tag), TRADITIONAL_CHINESE_FAMILIES, "{tag}");
+    }
+    // Each list carries its own script's faces and not the other's, which is the point of
+    // splitting them: `PingFang SC` covers the same code points as `PingFang TC`, so the
+    // fallback search would have kept it and drawn Simplified forms in a Traditional interface.
+    assert!(SIMPLIFIED_CHINESE_FAMILIES.iter().any(|f| f.contains("PingFang SC") && !f.contains("Source")));
+    assert!(!SIMPLIFIED_CHINESE_FAMILIES.iter().any(|f| f.contains("TC") || f.contains("JhengHei")));
+    assert!(TRADITIONAL_CHINESE_FAMILIES.iter().any(|f| f.contains("PingFang TC")));
+    assert!(!TRADITIONAL_CHINESE_FAMILIES.iter().any(|f| f.contains(" SC") || f.contains("YaHei") || f.contains("WenQuanYi")));
+    assert!(TRADITIONAL_CHINESE_FAMILIES.iter().any(|f| f.contains("Heiti TC") || f.contains("Hiragino Sans CNS")));
+    // The arm the fallback itself walks: Han hands over the list the locale's script picked.
+    assert_eq!(families_for(FallbackScript::Han, CjkLocale::from_tag(&active_cjk_locale())), chinese_families_for(&active_cjk_locale()));
+    // Han text is the only thing these lists serve; the Japanese order does not change.
+    assert_eq!(han_order_for("ja_JP.UTF-8")[0], FallbackScript::Japanese);
+}
+
+#[test]
+fn the_rendered_order_keeps_the_print_face_first() {
+    // A composed frame renders with these lists, so they keep the platform's print order: the
+    // interface prefers the platform's UI faces on its own (see `install_script_fallbacks` in
+    // the ui crate), and an existing project must not render differently because a window's
+    // chrome changed.
+    let pos = |list: &[&str], name: &str| list.iter().position(|f| *f == name).unwrap_or(usize::MAX);
+    assert!(
+        pos(JAPANESE_FAMILIES, "Yu Gothic") < pos(JAPANESE_FAMILIES, "Yu Gothic UI"),
+        "the print face must come before its UI sibling: {JAPANESE_FAMILIES:?}"
+    );
+    for name in ["Meiryo UI", "MS UI Gothic"] {
+        assert!(!JAPANESE_FAMILIES.contains(&name), "{name} belongs to the interface order, not this list");
+    }
+    assert_eq!(SIMPLIFIED_CHINESE_FAMILIES[0], "Microsoft YaHei");
+    assert_eq!(TRADITIONAL_CHINESE_FAMILIES[0], "Microsoft JhengHei");
+    for name in ["Microsoft YaHei UI", "Microsoft JhengHei UI", "PMingLiU"] {
+        assert!(
+            !SIMPLIFIED_CHINESE_FAMILIES.contains(&name) && !TRADITIONAL_CHINESE_FAMILIES.contains(&name),
+            "{name} belongs to the interface order, not these lists"
+        );
+    }
+}
+
+#[test]
+fn bundled_ui_fonts_cover_the_ukrainian_alphabet() {
+    const ALPHABET: &str = "АБВГҐДЕЄЖЗИІЇЙКЛМНОПРСТУФХЦЧШЩЬЮЯабвгґдеєжзиіїйклмнопрстуфхцчшщьюя’«»";
+    for (name, bytes) in
+        [("Inter Regular", INTER_REGULAR), ("Inter Medium", INTER_MEDIUM), ("Inter SemiBold", INTER_SEMIBOLD), ("JetBrains Mono", JETBRAINS_MONO_REGULAR)]
+    {
+        let font = FontRef::new(bytes).unwrap();
+        for c in ALPHABET.chars() {
+            assert!(covers(&font, c), "{name} cannot draw {c}");
+        }
+    }
+}
+
+#[test]
+fn metrics_and_coverage() {
+    let f = face(resolve("Inter", "Regular").face);
+    let m = f.metrics(100.0);
+    assert!(m.ascent > 80.0 && m.ascent < 110.0, "{m:?}");
+    assert!(m.descent > 10.0 && m.descent < 40.0);
+    assert!(m.cap_height > 60.0 && m.cap_height < 80.0);
+    assert!(f.has_char('A') && f.has_char('Ж'));
+    assert!(!f.has_char('\u{5d0}'), "Inter has no Hebrew");
+    assert!(f.has_feature(b"liga") || f.has_feature(b"calt"));
+}
+
+#[test]
+fn unknown_face_id_returns_bundled_default() {
+    let fallback = face(usize::MAX);
+    assert_eq!(fallback.id, 0);
+    assert_eq!(fallback.info.family, DEFAULT_FAMILY);
+    assert!(fallback.font().is_some());
+    assert!(Arc::ptr_eq(&fallback, &face(0)));
+}
diff --git a/crates/text/src/layout.rs b/crates/text/src/layout.rs
index 1f2e32115..179478517 100644
--- a/crates/text/src/layout.rs
+++ b/crates/text/src/layout.rs
@@ -1239,372 +1239,4 @@ pub fn measure(text: &str, style: &TextStyle) -> f32 {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn st(size: f32) -> TextStyle {
-        TextStyle { size, ..Default::default() }
-    }
-
-    fn ids(text: &str, s: &TextStyle) -> Vec<u32> {
-        layout_uncached(text, s, &ParagraphStyle::default()).glyphs.iter().map(|g| g.id).collect()
-    }
-
-    fn ot(f: impl FnOnce(&mut OpenType)) -> TextStyle {
-        let mut s = st(100.0);
-        f(&mut s.opentype);
-        s
-    }
-
-    fn serif() -> TextStyle {
-        TextStyle { family: "Noto Serif".into(), ..st(100.0) }
-    }
-
-    #[test]
-    fn bundled_faces_list_their_features() {
-        let inter = fonts::face(fonts::resolve("Inter", "Regular").face).features();
-        for t in ["ss01", "dlig", "frac", "tnum", "sups", "ordn"] {
-            assert!(inter.iter().any(|f| f == t), "{t} in {inter:?}");
-        }
-        let serif = fonts::face(fonts::resolve("Noto Serif", "Regular").face).features();
-        for t in ["smcp", "c2sc", "onum", "lnum"] {
-            assert!(serif.iter().any(|f| f == t), "{t} in {serif:?}");
-        }
-    }
-
-    #[test]
-    fn opentype_features_substitute_glyphs() {
-        let plain = st(100.0);
-        // Stylistic sets, fractions, ordinals, figure widths and discretionary ligatures.
-        assert_ne!(ids("1234567890", &plain), ids("1234567890", &ot(|o| o.set_stylistic_set(1, true))), "ss01 alternate digits");
-        assert_eq!(ids("1234567890", &plain), ids("1234567890", &ot(|o| o.set_stylistic_set(20, true))), "Inter has no ss20");
-        assert_ne!(ids("1/2", &plain), ids("1/2", &ot(|o| o.fractions = true)), "frac");
-        assert_ne!(ids("1a 2o No", &plain), ids("1a 2o No", &ot(|o| o.ordinals = true)), "ordn");
-        let tab = measure("1111", &ot(|o| o.figure_width = effectcraft_keyframe::FigureWidth::Tabular));
-        let prop = measure("1111", &ot(|o| o.figure_width = effectcraft_keyframe::FigureWidth::Proportional));
-        assert!((tab - prop).abs() > 1.0, "tabular {tab} vs proportional {prop}");
-        // Old-style figures (Noto Serif).
-        let old = TextStyle { opentype: OpenType { figure_style: effectcraft_keyframe::FigureStyle::OldStyle, ..Default::default() }, ..serif() };
-        assert_ne!(ids("123", &serif()), ids("123", &old), "onum");
-        // Contextual alternates are on by default; turning them off can only keep or change glyphs.
-        let no_calt = ot(|o| o.contextual_alternates = false);
-        assert_eq!(ids("Hello", &plain).len(), ids("Hello", &no_calt).len());
-    }
-
-    #[test]
-    fn true_small_caps_and_superscripts_with_faux_fallback() {
-        // Noto Serif has smcp: lowercase letters take their own small-capital glyphs at full size.
-        let sc = TextStyle { caps: Caps::Small, ..serif() };
-        let l = layout_uncached("Ab", &sc, &ParagraphStyle::default());
-        let upper_b = ids("B", &serif())[0];
-        assert_ne!(l.glyphs[1].id, upper_b, "true small cap glyph, not a scaled capital");
-        assert_eq!(l.glyphs[1].size, 100.0);
-        // Inter has no smcp: a capital scaled down.
-        let faux = layout_uncached("Ab", &TextStyle { caps: Caps::Small, ..st(100.0) }, &ParagraphStyle::default());
-        assert_eq!(faux.glyphs[1].id, ids("B", &st(100.0))[0]);
-        assert!((faux.glyphs[1].size - 78.0).abs() < 0.01);
-        // All Small Caps: capitals become small capitals too (c2sc).
-        let all = TextStyle { opentype: OpenType { all_small_caps: true, ..Default::default() }, ..serif() };
-        let a = layout_uncached("AB", &all, &ParagraphStyle::default());
-        assert_ne!(a.glyphs[0].id, ids("A", &serif())[0]);
-        // Superscript: Inter's sups figures at full size on the baseline; letters it lacks are
-        // synthesized (smaller and raised).
-        let sup = TextStyle { script: Script::Super, ..st(100.0) };
-        let s2 = layout_uncached("2", &sup, &ParagraphStyle::default());
-        assert_ne!(s2.glyphs[0].id, ids("2", &st(100.0))[0]);
-        assert_eq!(s2.glyphs[0].size, 100.0);
-        assert_eq!(s2.glyphs[0].y, 0.0);
-        let sq = layout_uncached("q", &sup, &ParagraphStyle::default());
-        if !feature_substitutes(sq.glyphs[0].face, b"sups", 'q') {
-            assert!(sq.glyphs[0].size < 60.0 && sq.glyphs[0].y < -20.0, "{:?}", sq.glyphs[0]);
-        }
-        let sub = layout_uncached("2", &TextStyle { script: Script::Sub, ..st(100.0) }, &ParagraphStyle::default());
-        assert_ne!(sub.glyphs[0].id, s2.glyphs[0].id);
-    }
-
-    #[test]
-    fn kerning_and_ligatures_change_advances() {
-        let kern = measure("AVAVAV", &st(100.0));
-        let nokern = measure("AVAVAV", &TextStyle { kerning: false, ..st(100.0) });
-        assert!(kern < nokern - 5.0, "kerning tightens AV: {kern} vs {nokern}");
-        // tracking adds 1/1000 em per cluster
-        let tracked = measure("AVAVAV", &TextStyle { tracking: 100.0, ..st(100.0) });
-        assert!((tracked - kern - 6.0 * 10.0).abs() < 0.5, "{tracked} {kern}");
-    }
-
-    #[test]
-    fn point_text_alignment() {
-        let l = layout("Hello", &st(50.0), &ParagraphStyle { align: Align::Center, ..Default::default() });
-        let line = &l.lines[0];
-        assert!((line.x + line.width / 2.0).abs() < 0.01);
-        let r = layout("Hello", &st(50.0), &ParagraphStyle { align: Align::Right, ..Default::default() });
-        assert!((r.lines[0].x + r.lines[0].width).abs() < 0.01);
-        assert_eq!(l.glyphs.len(), 5);
-        assert!(l.bounds[1] < -30.0 && l.bounds[3] > 5.0, "{:?}", l.bounds);
-    }
-
-    #[test]
-    fn wraps_area_text_and_justifies() {
-        let p = ParagraphStyle { width: Some(300.0), align: Align::Justify, ..Default::default() };
-        let l = layout("the quick brown fox jumps over the lazy dog again and again", &st(40.0), &p);
-        assert!(l.lines.len() >= 3, "{}", l.lines.len());
-        for line in &l.lines[..l.lines.len() - 1] {
-            assert!((line.width - 300.0).abs() < 0.5, "justified to the box: {}", line.width);
-        }
-        // the lines tile the text
-        assert_eq!(l.lines[0].range.start, 0);
-        for w in l.lines.windows(2) {
-            assert_eq!(w[0].range.end, w[1].range.start);
-            assert!(w[1].baseline > w[0].baseline);
-        }
-        let left = layout("the quick brown fox jumps over the lazy dog", &st(40.0), &ParagraphStyle { width: Some(300.0), ..Default::default() });
-        assert!(left.lines.iter().all(|l| l.width <= 300.0 + 0.01));
-    }
-
-    #[test]
-    fn newlines_make_paragraphs_and_leading_adds() {
-        let l = layout("one\ntwo\n\nfour", &st(30.0), &ParagraphStyle::default());
-        assert_eq!(l.lines.len(), 4);
-        assert_eq!(l.lines[1].range, 4..7);
-        assert_eq!(l.lines[2].range, 8..8);
-        let gap = l.lines[1].baseline - l.lines[0].baseline;
-        let l2 = layout("one\ntwo", &st(30.0), &ParagraphStyle { leading: 10.0, ..Default::default() });
-        assert!((l2.lines[1].baseline - l2.lines[0].baseline - gap - 10.0).abs() < 1e-3);
-    }
-
-    #[test]
-    fn carets_and_hit_testing() {
-        let l = layout("abc\nde", &st(40.0), &ParagraphStyle::default());
-        let (x0, _, li0) = l.caret(0);
-        let (x1, _, _) = l.caret(1);
-        let (x3, _, _) = l.caret(3);
-        assert!(x0.abs() < 1e-3 && x1 > x0 && x3 > x1);
-        assert_eq!(li0, 0);
-        let (_, b4, li4) = l.caret(4);
-        assert_eq!(li4, 1);
-        assert!(b4 > 0.0);
-        assert_eq!(l.hit(x1 + 1.0, 0.0), 1);
-        assert_eq!(l.hit(1000.0, b4), 6);
-        let rects = l.selection_rects(1, 5);
-        assert_eq!(rects.len(), 2);
-    }
-
-    #[test]
-    fn bidi_reorders_rtl_runs() {
-        // Hebrew letters are laid out right-to-left: the first logical letter is rightmost.
-        let l = layout("ab \u{5d0}\u{5d1}\u{5d2} cd", &st(40.0), &ParagraphStyle::default());
-        let x_of = |byte: usize| l.glyphs.iter().find(|g| g.cluster == byte).map(|g| g.x).unwrap();
-        let alef = "ab ".len();
-        let gimel = alef + 4;
-        assert!(x_of(alef) > x_of(gimel), "alef right of gimel");
-        assert!(x_of(0) < x_of(gimel) && x_of(alef) < x_of("ab \u{5d0}\u{5d1}\u{5d2} ".len()));
-    }
-
-    #[test]
-    fn caps_and_small_caps() {
-        let s = st(50.0);
-        let up = measure("HELLO", &s);
-        let all = measure("hello", &TextStyle { caps: Caps::All, ..s.clone() });
-        assert!((up - all).abs() < 0.01);
-        let small = measure("hello", &TextStyle { caps: Caps::Small, ..s.clone() });
-        assert!(small < up * 0.9 && small > up * 0.6, "{small} {up}");
-        let l = layout("Hi", &TextStyle { baseline_shift: 10.0, underline: true, ..s }, &ParagraphStyle::default());
-        assert!((l.glyphs[0].y + 10.0).abs() < 1e-3);
-        assert_eq!(l.underlines.len(), 1);
-    }
-
-    #[test]
-    fn ligature_caret_interpolates() {
-        // Inter has an "fi"-like ligature only via calt in some versions; use "ffi" which most
-        // fonts ligate. Whatever shaping does, every char boundary has a caret.
-        let l = layout("office", &st(40.0), &ParagraphStyle::default());
-        let stops: Vec<usize> = l.lines[0].carets.iter().map(|c| c.0).collect();
-        assert_eq!(stops, vec![0, 1, 2, 3, 4, 5, 6]);
-        let xs: Vec<f32> = l.lines[0].carets.iter().map(|c| c.1).collect();
-        assert!(xs.windows(2).all(|w| w[1] >= w[0]), "{xs:?}");
-    }
-
-    #[test]
-    fn fallback_font_for_missing_glyphs() {
-        // Inter lacks Devanagari/Hebrew; Noto Serif lacks Hebrew too → glyphs still produced (notdef)
-        let l = layout("A\u{3b1}", &TextStyle { family: "Noto Serif".into(), ..st(40.0) }, &ParagraphStyle::default());
-        assert_eq!(l.glyphs.len(), 2);
-        assert!(l.glyphs.iter().all(|g| g.id != 0));
-    }
-
-    #[test]
-    fn empty_text_has_a_caret() {
-        let l = layout("", &st(40.0), &ParagraphStyle::default());
-        assert_eq!(l.lines.len(), 1);
-        assert_eq!(l.caret(0).0, 0.0);
-        assert!(l.bounds[3] > l.bounds[1]);
-    }
-
-    fn rich(text: &str, runs: &[(Range<usize>, TextStyle)], para: ParagraphStyle) -> Layout {
-        layout_rich_uncached(text, runs, &[para])
-    }
-
-    #[test]
-    fn mixed_sizes_share_a_baseline_and_take_the_largest_leading() {
-        let text = "small BIG\nnext";
-        let runs = [(0..6, st(20.0)), (6..9, st(80.0)), (9..text.len(), st(20.0))];
-        let l = rich(text, &runs, ParagraphStyle::default());
-        assert_eq!(l.lines.len(), 2);
-        let y0 = l.glyphs[0].y;
-        assert!(l.glyphs[..9].iter().all(|g| (g.y - y0).abs() < 1e-3), "one baseline per line");
-        assert!(l.glyphs[7].size > l.glyphs[0].size * 3.0);
-        // Line 2's advance is its own leading (20 px text: 24 px); line 1 is as tall as the big run.
-        assert!((l.lines[1].baseline - l.lines[0].baseline - 24.0).abs() < 1e-3, "{}", l.lines[1].baseline);
-        assert!(l.lines[0].ascent > 60.0);
-        // A big run on the second line pushes it down by its 120% leading.
-        let text2 = "aa\nBB";
-        let l2 = rich(text2, &[(0..3, st(20.0)), (3..5, st(80.0))], ParagraphStyle::default());
-        assert!((l2.lines[1].baseline - 96.0).abs() < 1e-3);
-        // Explicit leading wins over auto.
-        let mut fixed = st(20.0);
-        fixed.leading = Some(50.0);
-        let l3 = rich("a\nb", &[(0..3, fixed)], ParagraphStyle::default());
-        assert!((l3.lines[1].baseline - 50.0).abs() < 1e-3);
-    }
-
-    #[test]
-    fn super_subscript_tsume_and_kerning_metrics() {
-        let base = st(100.0);
-        let sup = TextStyle { script: Script::Super, ..base.clone() };
-        let sub = TextStyle { script: Script::Sub, ..base.clone() };
-        // A letter the font has no superior / inferior glyph for: synthesized.
-        let inter = fonts::resolve("Inter", "Regular").face;
-        let c = "qwkzvjxyQWK".chars().find(|&c| !feature_substitutes(inter, b"sups", c) && !feature_substitutes(inter, b"subs", c)).unwrap();
-        let text: String = ['x', c, 'y', c].iter().collect();
-        let l = rich(&text, &[(0..1, base.clone()), (1..2, sup), (2..3, base.clone()), (3..4, sub)], ParagraphStyle::default());
-        let g = &l.glyphs;
-        assert!((g[1].size - 58.3).abs() < 0.1);
-        assert!((g[1].y - (g[0].y - 33.3)).abs() < 0.1, "superscript raised by a third of the size");
-        assert!((g[3].y - (g[2].y + 33.3)).abs() < 0.1, "subscript lowered");
-        // Tsume removes side bearings; full tsume is narrower than none.
-        let w0 = measure("onion", &base);
-        let w1 = measure("onion", &TextStyle { tsume: 1.0, ..base.clone() });
-        assert!(w1 < w0 - 5.0, "{w1} vs {w0}");
-        // Manual kerning: +100/1000 em before each of the 5 later characters of AVAVAV, metrics off.
-        let nokern = measure("AVAVAV", &TextStyle { kerning: false, ..base.clone() });
-        let manual = measure("AVAVAV", &TextStyle { manual_kern: Some(100.0), ..base.clone() });
-        assert!((manual - nokern - 50.0).abs() < 0.5, "{manual} {nokern}");
-        let optical = measure("AVAVAV", &TextStyle { optical: true, ..base.clone() });
-        assert!(optical > 0.0 && (optical - nokern).abs() < 100.0);
-        // Horizontal scale stretches advances.
-        let wide = measure("onion", &TextStyle { h_scale: 2.0, ..base.clone() });
-        assert!((wide - 2.0 * w0).abs() < 0.5);
-        let l = layout("o", &TextStyle { h_scale: 2.0, v_scale: 0.5, ..base }, &ParagraphStyle::default());
-        assert_eq!((l.glyphs[0].h_scale, l.glyphs[0].v_scale), (2.0, 0.5));
-    }
-
-    #[test]
-    fn indents_and_paragraph_spacing() {
-        let s = st(20.0);
-        let text = "first paragraph here\nsecond one";
-        let p0 = ParagraphStyle { width: Some(400.0), indent_start: 30.0, indent_first: 15.0, space_after: 10.0, ..Default::default() };
-        let p1 = ParagraphStyle { width: Some(400.0), indent_end: 50.0, align: Align::Right, space_before: 7.0, ..Default::default() };
-        let l = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p0.clone(), p1]);
-        assert!((l.lines[0].x - 45.0).abs() < 1e-3, "left + first-line indent: {}", l.lines[0].x);
-        assert!((l.lines[1].x + l.lines[1].width - 350.0).abs() < 0.5, "right indent: {}", l.lines[1].x + l.lines[1].width);
-        assert!((l.lines[1].baseline - l.lines[0].baseline - (24.0 + 10.0 + 7.0)).abs() < 1e-3);
-        assert_eq!((l.lines[0].para, l.lines[1].para), (0, 1));
-        assert!(l.lines[0].para_end && l.lines[1].para_end);
-        // Wrapped lines after the first don't get the first-line indent.
-        let long = "word ".repeat(30);
-        let l = layout_rich_uncached(&long, &[(0..long.len(), s.clone())], &[p0]);
-        assert!(l.lines.len() > 2);
-        assert!((l.lines[1].x - 30.0).abs() < 1e-3);
-        assert!(l.lines.iter().all(|ln| ln.x + ln.width <= 400.0 + 0.5));
-        assert!(!l.lines[0].para_end);
-        // Point text: a right-aligned paragraph's end indent moves it left of the origin.
-        let l = layout_rich_uncached("abc", &[(0..3, s)], &[ParagraphStyle { align: Align::Right, indent_end: 12.0, ..Default::default() }]);
-        assert!((l.lines[0].x + l.lines[0].width + 12.0).abs() < 1e-3);
-    }
-
-    #[test]
-    fn justify_last_line_modes_and_every_line_composer() {
-        let text = "the quick brown fox jumps over the lazy dog and keeps running far";
-        let s = st(30.0);
-        let p = |last: Align| ParagraphStyle { width: Some(320.0), align: Align::Justify, justify_last: last, ..Default::default() };
-        let left = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p(Align::Left)]);
-        let n = left.lines.len();
-        assert!(n >= 3);
-        assert!((left.lines[0].width - 320.0).abs() < 0.5);
-        assert!(left.lines[n - 1].width < 320.0 && left.lines[n - 1].x.abs() < 1e-3);
-        let center = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p(Align::Center)]);
-        let lc = &center.lines[n - 1];
-        assert!((lc.x - (320.0 - lc.width) / 2.0).abs() < 0.5);
-        let right = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p(Align::Right)]);
-        let lr = &right.lines[n - 1];
-        assert!((lr.x + lr.width - 320.0).abs() < 0.5);
-        let all = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p(Align::Justify)]);
-        assert!((all.lines[n - 1].width - 320.0).abs() < 0.5, "justify all stretches the last line");
-        // Every-line composer: never worse (summed squared slack) than greedy breaking.
-        let slack = |l: &Layout| -> f32 { l.lines[..l.lines.len() - 1].iter().map(|ln| (320.0 - ln.width).powi(2)).sum() };
-        let greedy = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[ParagraphStyle { width: Some(320.0), ..Default::default() }]);
-        let every = layout_rich_uncached(text, &[(0..text.len(), s)], &[ParagraphStyle { width: Some(320.0), every_line: true, ..Default::default() }]);
-        assert!(slack(&every) <= slack(&greedy) + 1e-3, "{} vs {}", slack(&every), slack(&greedy));
-        assert!(every.lines.iter().all(|ln| ln.width <= 320.0 + 0.5));
-    }
-
-    #[test]
-    fn hanging_punctuation_overhangs_the_box() {
-        let s = st(40.0);
-        let text = "\"Hi.\"";
-        let p = ParagraphStyle { width: Some(400.0), hanging: true, ..Default::default() };
-        let l = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p]);
-        assert!(l.lines[0].x < -1.0, "opening quote hangs left: {}", l.lines[0].x);
-        let r = layout_rich_uncached(
-            text,
-            &[(0..text.len(), s)],
-            &[ParagraphStyle { width: Some(400.0), hanging: true, align: Align::Right, ..Default::default() }],
-        );
-        assert!(r.lines[0].x + r.lines[0].width > 401.0, "closing quote hangs right");
-    }
-
-    #[test]
-    fn oversized_layout_requests_are_bounded_without_caching() {
-        let text = "a".repeat(MAX_LAYOUT_BYTES + 1);
-        let layout = layout(&text, &TextStyle::default(), &ParagraphStyle::default());
-        assert_eq!(layout.text_len, text.len());
-        assert!(layout.lines.is_empty() && layout.glyphs.is_empty());
-        assert!(layout_rich_uncached("ok", &[], &[]).lines.len() == 1);
-    }
-
-    #[test]
-    fn rtl_paragraph_carets_run_right_to_left() {
-        let text = "\u{5d0}\u{5d1}\u{5d2}";
-        let l = layout_rich_uncached(text, &[(0..text.len(), st(40.0))], &[ParagraphStyle { rtl: Some(true), ..Default::default() }]);
-        let xs: Vec<f32> = l.lines[0].carets.iter().map(|c| c.1).collect();
-        assert_eq!(xs.len(), 4);
-        assert!(xs.windows(2).all(|w| w[1] < w[0]), "{xs:?}");
-        // Hit testing returns the logical position nearest the point.
-        assert_eq!(l.hit(xs[1] + 0.5, 0.0), 2);
-        assert_eq!(l.hit(xs[0] + 50.0, 0.0), 0);
-    }
-
-    /// #1563: text set in a named instance (`Black`) is laid out at the instance's axis values,
-    /// as if they had been set as variations; axes set on the text itself keep their values.
-    #[test]
-    fn named_instance_sets_the_base_variations() {
-        const FAMILY: &str = "EffectCraft Layout Instance Test";
-        fonts::add_font_data(crate::sfnt::test_font::variable(FAMILY, &[("Light", 300.0, None), ("Black", 900.0, None)], true));
-        let st = |style: &str, variations: Vec<(String, f32)>| TextStyle {
-            family: FAMILY.into(),
-            style: style.into(),
-            size: 50.0,
-            variations,
-            ..Default::default()
-        };
-        let coords = |l: &Layout| l.glyphs.iter().map(|g| crate::variable::coords(g.variations).to_vec()).collect::<Vec<_>>();
-        let black = layout_uncached("Hi", &st("Black", vec![]), &ParagraphStyle::default());
-        assert!(!black.glyphs.is_empty());
-        assert!(coords(&black).iter().all(|c| c == &[("wght".to_string(), 900.0)]), "{:?}", coords(&black));
-        let set = layout_uncached("Hi", &st("Black", vec![("wght".into(), 500.0)]), &ParagraphStyle::default());
-        assert!(coords(&set).iter().all(|c| c == &[("wght".to_string(), 500.0)]), "{:?}", coords(&set));
-        // A static family keeps no variations.
-        let inter = layout_uncached("Hi", &TextStyle::default(), &ParagraphStyle::default());
-        assert!(inter.glyphs.iter().all(|g| g.variations == 0));
-    }
-}
+mod tests;
diff --git a/crates/text/src/layout/tests.rs b/crates/text/src/layout/tests.rs
new file mode 100644
index 000000000..9079a1225
--- /dev/null
+++ b/crates/text/src/layout/tests.rs
@@ -0,0 +1,359 @@
+use super::*;
+
+fn st(size: f32) -> TextStyle {
+    TextStyle { size, ..Default::default() }
+}
+
+fn ids(text: &str, s: &TextStyle) -> Vec<u32> {
+    layout_uncached(text, s, &ParagraphStyle::default()).glyphs.iter().map(|g| g.id).collect()
+}
+
+fn ot(f: impl FnOnce(&mut OpenType)) -> TextStyle {
+    let mut s = st(100.0);
+    f(&mut s.opentype);
+    s
+}
+
+fn serif() -> TextStyle {
+    TextStyle { family: "Noto Serif".into(), ..st(100.0) }
+}
+
+#[test]
+fn bundled_faces_list_their_features() {
+    let inter = fonts::face(fonts::resolve("Inter", "Regular").face).features();
+    for t in ["ss01", "dlig", "frac", "tnum", "sups", "ordn"] {
+        assert!(inter.iter().any(|f| f == t), "{t} in {inter:?}");
+    }
+    let serif = fonts::face(fonts::resolve("Noto Serif", "Regular").face).features();
+    for t in ["smcp", "c2sc", "onum", "lnum"] {
+        assert!(serif.iter().any(|f| f == t), "{t} in {serif:?}");
+    }
+}
+
+#[test]
+fn opentype_features_substitute_glyphs() {
+    let plain = st(100.0);
+    // Stylistic sets, fractions, ordinals, figure widths and discretionary ligatures.
+    assert_ne!(ids("1234567890", &plain), ids("1234567890", &ot(|o| o.set_stylistic_set(1, true))), "ss01 alternate digits");
+    assert_eq!(ids("1234567890", &plain), ids("1234567890", &ot(|o| o.set_stylistic_set(20, true))), "Inter has no ss20");
+    assert_ne!(ids("1/2", &plain), ids("1/2", &ot(|o| o.fractions = true)), "frac");
+    assert_ne!(ids("1a 2o No", &plain), ids("1a 2o No", &ot(|o| o.ordinals = true)), "ordn");
+    let tab = measure("1111", &ot(|o| o.figure_width = effectcraft_keyframe::FigureWidth::Tabular));
+    let prop = measure("1111", &ot(|o| o.figure_width = effectcraft_keyframe::FigureWidth::Proportional));
+    assert!((tab - prop).abs() > 1.0, "tabular {tab} vs proportional {prop}");
+    // Old-style figures (Noto Serif).
+    let old = TextStyle { opentype: OpenType { figure_style: effectcraft_keyframe::FigureStyle::OldStyle, ..Default::default() }, ..serif() };
+    assert_ne!(ids("123", &serif()), ids("123", &old), "onum");
+    // Contextual alternates are on by default; turning them off can only keep or change glyphs.
+    let no_calt = ot(|o| o.contextual_alternates = false);
+    assert_eq!(ids("Hello", &plain).len(), ids("Hello", &no_calt).len());
+}
+
+#[test]
+fn true_small_caps_and_superscripts_with_faux_fallback() {
+    // Noto Serif has smcp: lowercase letters take their own small-capital glyphs at full size.
+    let sc = TextStyle { caps: Caps::Small, ..serif() };
+    let l = layout_uncached("Ab", &sc, &ParagraphStyle::default());
+    let upper_b = ids("B", &serif())[0];
+    assert_ne!(l.glyphs[1].id, upper_b, "true small cap glyph, not a scaled capital");
+    assert_eq!(l.glyphs[1].size, 100.0);
+    // Inter has no smcp: a capital scaled down.
+    let faux = layout_uncached("Ab", &TextStyle { caps: Caps::Small, ..st(100.0) }, &ParagraphStyle::default());
+    assert_eq!(faux.glyphs[1].id, ids("B", &st(100.0))[0]);
+    assert!((faux.glyphs[1].size - 78.0).abs() < 0.01);
+    // All Small Caps: capitals become small capitals too (c2sc).
+    let all = TextStyle { opentype: OpenType { all_small_caps: true, ..Default::default() }, ..serif() };
+    let a = layout_uncached("AB", &all, &ParagraphStyle::default());
+    assert_ne!(a.glyphs[0].id, ids("A", &serif())[0]);
+    // Superscript: Inter's sups figures at full size on the baseline; letters it lacks are
+    // synthesized (smaller and raised).
+    let sup = TextStyle { script: Script::Super, ..st(100.0) };
+    let s2 = layout_uncached("2", &sup, &ParagraphStyle::default());
+    assert_ne!(s2.glyphs[0].id, ids("2", &st(100.0))[0]);
+    assert_eq!(s2.glyphs[0].size, 100.0);
+    assert_eq!(s2.glyphs[0].y, 0.0);
+    let sq = layout_uncached("q", &sup, &ParagraphStyle::default());
+    if !feature_substitutes(sq.glyphs[0].face, b"sups", 'q') {
+        assert!(sq.glyphs[0].size < 60.0 && sq.glyphs[0].y < -20.0, "{:?}", sq.glyphs[0]);
+    }
+    let sub = layout_uncached("2", &TextStyle { script: Script::Sub, ..st(100.0) }, &ParagraphStyle::default());
+    assert_ne!(sub.glyphs[0].id, s2.glyphs[0].id);
+}
+
+#[test]
+fn kerning_and_ligatures_change_advances() {
+    let kern = measure("AVAVAV", &st(100.0));
+    let nokern = measure("AVAVAV", &TextStyle { kerning: false, ..st(100.0) });
+    assert!(kern < nokern - 5.0, "kerning tightens AV: {kern} vs {nokern}");
+    // tracking adds 1/1000 em per cluster
+    let tracked = measure("AVAVAV", &TextStyle { tracking: 100.0, ..st(100.0) });
+    assert!((tracked - kern - 6.0 * 10.0).abs() < 0.5, "{tracked} {kern}");
+}
+
+#[test]
+fn point_text_alignment() {
+    let l = layout("Hello", &st(50.0), &ParagraphStyle { align: Align::Center, ..Default::default() });
+    let line = &l.lines[0];
+    assert!((line.x + line.width / 2.0).abs() < 0.01);
+    let r = layout("Hello", &st(50.0), &ParagraphStyle { align: Align::Right, ..Default::default() });
+    assert!((r.lines[0].x + r.lines[0].width).abs() < 0.01);
+    assert_eq!(l.glyphs.len(), 5);
+    assert!(l.bounds[1] < -30.0 && l.bounds[3] > 5.0, "{:?}", l.bounds);
+}
+
+#[test]
+fn wraps_area_text_and_justifies() {
+    let p = ParagraphStyle { width: Some(300.0), align: Align::Justify, ..Default::default() };
+    let l = layout("the quick brown fox jumps over the lazy dog again and again", &st(40.0), &p);
+    assert!(l.lines.len() >= 3, "{}", l.lines.len());
+    for line in &l.lines[..l.lines.len() - 1] {
+        assert!((line.width - 300.0).abs() < 0.5, "justified to the box: {}", line.width);
+    }
+    // the lines tile the text
+    assert_eq!(l.lines[0].range.start, 0);
+    for w in l.lines.windows(2) {
+        assert_eq!(w[0].range.end, w[1].range.start);
+        assert!(w[1].baseline > w[0].baseline);
+    }
+    let left = layout("the quick brown fox jumps over the lazy dog", &st(40.0), &ParagraphStyle { width: Some(300.0), ..Default::default() });
+    assert!(left.lines.iter().all(|l| l.width <= 300.0 + 0.01));
+}
+
+#[test]
+fn newlines_make_paragraphs_and_leading_adds() {
+    let l = layout("one\ntwo\n\nfour", &st(30.0), &ParagraphStyle::default());
+    assert_eq!(l.lines.len(), 4);
+    assert_eq!(l.lines[1].range, 4..7);
+    assert_eq!(l.lines[2].range, 8..8);
+    let gap = l.lines[1].baseline - l.lines[0].baseline;
+    let l2 = layout("one\ntwo", &st(30.0), &ParagraphStyle { leading: 10.0, ..Default::default() });
+    assert!((l2.lines[1].baseline - l2.lines[0].baseline - gap - 10.0).abs() < 1e-3);
+}
+
+#[test]
+fn carets_and_hit_testing() {
+    let l = layout("abc\nde", &st(40.0), &ParagraphStyle::default());
+    let (x0, _, li0) = l.caret(0);
+    let (x1, _, _) = l.caret(1);
+    let (x3, _, _) = l.caret(3);
+    assert!(x0.abs() < 1e-3 && x1 > x0 && x3 > x1);
+    assert_eq!(li0, 0);
+    let (_, b4, li4) = l.caret(4);
+    assert_eq!(li4, 1);
+    assert!(b4 > 0.0);
+    assert_eq!(l.hit(x1 + 1.0, 0.0), 1);
+    assert_eq!(l.hit(1000.0, b4), 6);
+    let rects = l.selection_rects(1, 5);
+    assert_eq!(rects.len(), 2);
+}
+
+#[test]
+fn bidi_reorders_rtl_runs() {
+    // Hebrew letters are laid out right-to-left: the first logical letter is rightmost.
+    let l = layout("ab \u{5d0}\u{5d1}\u{5d2} cd", &st(40.0), &ParagraphStyle::default());
+    let x_of = |byte: usize| l.glyphs.iter().find(|g| g.cluster == byte).map(|g| g.x).unwrap();
+    let alef = "ab ".len();
+    let gimel = alef + 4;
+    assert!(x_of(alef) > x_of(gimel), "alef right of gimel");
+    assert!(x_of(0) < x_of(gimel) && x_of(alef) < x_of("ab \u{5d0}\u{5d1}\u{5d2} ".len()));
+}
+
+#[test]
+fn caps_and_small_caps() {
+    let s = st(50.0);
+    let up = measure("HELLO", &s);
+    let all = measure("hello", &TextStyle { caps: Caps::All, ..s.clone() });
+    assert!((up - all).abs() < 0.01);
+    let small = measure("hello", &TextStyle { caps: Caps::Small, ..s.clone() });
+    assert!(small < up * 0.9 && small > up * 0.6, "{small} {up}");
+    let l = layout("Hi", &TextStyle { baseline_shift: 10.0, underline: true, ..s }, &ParagraphStyle::default());
+    assert!((l.glyphs[0].y + 10.0).abs() < 1e-3);
+    assert_eq!(l.underlines.len(), 1);
+}
+
+#[test]
+fn ligature_caret_interpolates() {
+    // Inter has an "fi"-like ligature only via calt in some versions; use "ffi" which most
+    // fonts ligate. Whatever shaping does, every char boundary has a caret.
+    let l = layout("office", &st(40.0), &ParagraphStyle::default());
+    let stops: Vec<usize> = l.lines[0].carets.iter().map(|c| c.0).collect();
+    assert_eq!(stops, vec![0, 1, 2, 3, 4, 5, 6]);
+    let xs: Vec<f32> = l.lines[0].carets.iter().map(|c| c.1).collect();
+    assert!(xs.windows(2).all(|w| w[1] >= w[0]), "{xs:?}");
+}
+
+#[test]
+fn fallback_font_for_missing_glyphs() {
+    // Inter lacks Devanagari/Hebrew; Noto Serif lacks Hebrew too → glyphs still produced (notdef)
+    let l = layout("A\u{3b1}", &TextStyle { family: "Noto Serif".into(), ..st(40.0) }, &ParagraphStyle::default());
+    assert_eq!(l.glyphs.len(), 2);
+    assert!(l.glyphs.iter().all(|g| g.id != 0));
+}
+
+#[test]
+fn empty_text_has_a_caret() {
+    let l = layout("", &st(40.0), &ParagraphStyle::default());
+    assert_eq!(l.lines.len(), 1);
+    assert_eq!(l.caret(0).0, 0.0);
+    assert!(l.bounds[3] > l.bounds[1]);
+}
+
+fn rich(text: &str, runs: &[(Range<usize>, TextStyle)], para: ParagraphStyle) -> Layout {
+    layout_rich_uncached(text, runs, &[para])
+}
+
+#[test]
+fn mixed_sizes_share_a_baseline_and_take_the_largest_leading() {
+    let text = "small BIG\nnext";
+    let runs = [(0..6, st(20.0)), (6..9, st(80.0)), (9..text.len(), st(20.0))];
+    let l = rich(text, &runs, ParagraphStyle::default());
+    assert_eq!(l.lines.len(), 2);
+    let y0 = l.glyphs[0].y;
+    assert!(l.glyphs[..9].iter().all(|g| (g.y - y0).abs() < 1e-3), "one baseline per line");
+    assert!(l.glyphs[7].size > l.glyphs[0].size * 3.0);
+    // Line 2's advance is its own leading (20 px text: 24 px); line 1 is as tall as the big run.
+    assert!((l.lines[1].baseline - l.lines[0].baseline - 24.0).abs() < 1e-3, "{}", l.lines[1].baseline);
+    assert!(l.lines[0].ascent > 60.0);
+    // A big run on the second line pushes it down by its 120% leading.
+    let text2 = "aa\nBB";
+    let l2 = rich(text2, &[(0..3, st(20.0)), (3..5, st(80.0))], ParagraphStyle::default());
+    assert!((l2.lines[1].baseline - 96.0).abs() < 1e-3);
+    // Explicit leading wins over auto.
+    let mut fixed = st(20.0);
+    fixed.leading = Some(50.0);
+    let l3 = rich("a\nb", &[(0..3, fixed)], ParagraphStyle::default());
+    assert!((l3.lines[1].baseline - 50.0).abs() < 1e-3);
+}
+
+#[test]
+fn super_subscript_tsume_and_kerning_metrics() {
+    let base = st(100.0);
+    let sup = TextStyle { script: Script::Super, ..base.clone() };
+    let sub = TextStyle { script: Script::Sub, ..base.clone() };
+    // A letter the font has no superior / inferior glyph for: synthesized.
+    let inter = fonts::resolve("Inter", "Regular").face;
+    let c = "qwkzvjxyQWK".chars().find(|&c| !feature_substitutes(inter, b"sups", c) && !feature_substitutes(inter, b"subs", c)).unwrap();
+    let text: String = ['x', c, 'y', c].iter().collect();
+    let l = rich(&text, &[(0..1, base.clone()), (1..2, sup), (2..3, base.clone()), (3..4, sub)], ParagraphStyle::default());
+    let g = &l.glyphs;
+    assert!((g[1].size - 58.3).abs() < 0.1);
+    assert!((g[1].y - (g[0].y - 33.3)).abs() < 0.1, "superscript raised by a third of the size");
+    assert!((g[3].y - (g[2].y + 33.3)).abs() < 0.1, "subscript lowered");
+    // Tsume removes side bearings; full tsume is narrower than none.
+    let w0 = measure("onion", &base);
+    let w1 = measure("onion", &TextStyle { tsume: 1.0, ..base.clone() });
+    assert!(w1 < w0 - 5.0, "{w1} vs {w0}");
+    // Manual kerning: +100/1000 em before each of the 5 later characters of AVAVAV, metrics off.
+    let nokern = measure("AVAVAV", &TextStyle { kerning: false, ..base.clone() });
+    let manual = measure("AVAVAV", &TextStyle { manual_kern: Some(100.0), ..base.clone() });
+    assert!((manual - nokern - 50.0).abs() < 0.5, "{manual} {nokern}");
+    let optical = measure("AVAVAV", &TextStyle { optical: true, ..base.clone() });
+    assert!(optical > 0.0 && (optical - nokern).abs() < 100.0);
+    // Horizontal scale stretches advances.
+    let wide = measure("onion", &TextStyle { h_scale: 2.0, ..base.clone() });
+    assert!((wide - 2.0 * w0).abs() < 0.5);
+    let l = layout("o", &TextStyle { h_scale: 2.0, v_scale: 0.5, ..base }, &ParagraphStyle::default());
+    assert_eq!((l.glyphs[0].h_scale, l.glyphs[0].v_scale), (2.0, 0.5));
+}
+
+#[test]
+fn indents_and_paragraph_spacing() {
+    let s = st(20.0);
+    let text = "first paragraph here\nsecond one";
+    let p0 = ParagraphStyle { width: Some(400.0), indent_start: 30.0, indent_first: 15.0, space_after: 10.0, ..Default::default() };
+    let p1 = ParagraphStyle { width: Some(400.0), indent_end: 50.0, align: Align::Right, space_before: 7.0, ..Default::default() };
+    let l = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p0.clone(), p1]);
+    assert!((l.lines[0].x - 45.0).abs() < 1e-3, "left + first-line indent: {}", l.lines[0].x);
+    assert!((l.lines[1].x + l.lines[1].width - 350.0).abs() < 0.5, "right indent: {}", l.lines[1].x + l.lines[1].width);
+    assert!((l.lines[1].baseline - l.lines[0].baseline - (24.0 + 10.0 + 7.0)).abs() < 1e-3);
+    assert_eq!((l.lines[0].para, l.lines[1].para), (0, 1));
+    assert!(l.lines[0].para_end && l.lines[1].para_end);
+    // Wrapped lines after the first don't get the first-line indent.
+    let long = "word ".repeat(30);
+    let l = layout_rich_uncached(&long, &[(0..long.len(), s.clone())], &[p0]);
+    assert!(l.lines.len() > 2);
+    assert!((l.lines[1].x - 30.0).abs() < 1e-3);
+    assert!(l.lines.iter().all(|ln| ln.x + ln.width <= 400.0 + 0.5));
+    assert!(!l.lines[0].para_end);
+    // Point text: a right-aligned paragraph's end indent moves it left of the origin.
+    let l = layout_rich_uncached("abc", &[(0..3, s)], &[ParagraphStyle { align: Align::Right, indent_end: 12.0, ..Default::default() }]);
+    assert!((l.lines[0].x + l.lines[0].width + 12.0).abs() < 1e-3);
+}
+
+#[test]
+fn justify_last_line_modes_and_every_line_composer() {
+    let text = "the quick brown fox jumps over the lazy dog and keeps running far";
+    let s = st(30.0);
+    let p = |last: Align| ParagraphStyle { width: Some(320.0), align: Align::Justify, justify_last: last, ..Default::default() };
+    let left = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p(Align::Left)]);
+    let n = left.lines.len();
+    assert!(n >= 3);
+    assert!((left.lines[0].width - 320.0).abs() < 0.5);
+    assert!(left.lines[n - 1].width < 320.0 && left.lines[n - 1].x.abs() < 1e-3);
+    let center = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p(Align::Center)]);
+    let lc = &center.lines[n - 1];
+    assert!((lc.x - (320.0 - lc.width) / 2.0).abs() < 0.5);
+    let right = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p(Align::Right)]);
+    let lr = &right.lines[n - 1];
+    assert!((lr.x + lr.width - 320.0).abs() < 0.5);
+    let all = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p(Align::Justify)]);
+    assert!((all.lines[n - 1].width - 320.0).abs() < 0.5, "justify all stretches the last line");
+    // Every-line composer: never worse (summed squared slack) than greedy breaking.
+    let slack = |l: &Layout| -> f32 { l.lines[..l.lines.len() - 1].iter().map(|ln| (320.0 - ln.width).powi(2)).sum() };
+    let greedy = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[ParagraphStyle { width: Some(320.0), ..Default::default() }]);
+    let every = layout_rich_uncached(text, &[(0..text.len(), s)], &[ParagraphStyle { width: Some(320.0), every_line: true, ..Default::default() }]);
+    assert!(slack(&every) <= slack(&greedy) + 1e-3, "{} vs {}", slack(&every), slack(&greedy));
+    assert!(every.lines.iter().all(|ln| ln.width <= 320.0 + 0.5));
+}
+
+#[test]
+fn hanging_punctuation_overhangs_the_box() {
+    let s = st(40.0);
+    let text = "\"Hi.\"";
+    let p = ParagraphStyle { width: Some(400.0), hanging: true, ..Default::default() };
+    let l = layout_rich_uncached(text, &[(0..text.len(), s.clone())], &[p]);
+    assert!(l.lines[0].x < -1.0, "opening quote hangs left: {}", l.lines[0].x);
+    let r =
+        layout_rich_uncached(text, &[(0..text.len(), s)], &[ParagraphStyle { width: Some(400.0), hanging: true, align: Align::Right, ..Default::default() }]);
+    assert!(r.lines[0].x + r.lines[0].width > 401.0, "closing quote hangs right");
+}
+
+#[test]
+fn oversized_layout_requests_are_bounded_without_caching() {
+    let text = "a".repeat(MAX_LAYOUT_BYTES + 1);
+    let layout = layout(&text, &TextStyle::default(), &ParagraphStyle::default());
+    assert_eq!(layout.text_len, text.len());
+    assert!(layout.lines.is_empty() && layout.glyphs.is_empty());
+    assert!(layout_rich_uncached("ok", &[], &[]).lines.len() == 1);
+}
+
+#[test]
+fn rtl_paragraph_carets_run_right_to_left() {
+    let text = "\u{5d0}\u{5d1}\u{5d2}";
+    let l = layout_rich_uncached(text, &[(0..text.len(), st(40.0))], &[ParagraphStyle { rtl: Some(true), ..Default::default() }]);
+    let xs: Vec<f32> = l.lines[0].carets.iter().map(|c| c.1).collect();
+    assert_eq!(xs.len(), 4);
+    assert!(xs.windows(2).all(|w| w[1] < w[0]), "{xs:?}");
+    // Hit testing returns the logical position nearest the point.
+    assert_eq!(l.hit(xs[1] + 0.5, 0.0), 2);
+    assert_eq!(l.hit(xs[0] + 50.0, 0.0), 0);
+}
+
+/// #1563: text set in a named instance (`Black`) is laid out at the instance's axis values,
+/// as if they had been set as variations; axes set on the text itself keep their values.
+#[test]
+fn named_instance_sets_the_base_variations() {
+    const FAMILY: &str = "EffectCraft Layout Instance Test";
+    fonts::add_font_data(crate::sfnt::test_font::variable(FAMILY, &[("Light", 300.0, None), ("Black", 900.0, None)], true));
+    let st =
+        |style: &str, variations: Vec<(String, f32)>| TextStyle { family: FAMILY.into(), style: style.into(), size: 50.0, variations, ..Default::default() };
+    let coords = |l: &Layout| l.glyphs.iter().map(|g| crate::variable::coords(g.variations).to_vec()).collect::<Vec<_>>();
+    let black = layout_uncached("Hi", &st("Black", vec![]), &ParagraphStyle::default());
+    assert!(!black.glyphs.is_empty());
+    assert!(coords(&black).iter().all(|c| c == &[("wght".to_string(), 900.0)]), "{:?}", coords(&black));
+    let set = layout_uncached("Hi", &st("Black", vec![("wght".into(), 500.0)]), &ParagraphStyle::default());
+    assert!(coords(&set).iter().all(|c| c == &[("wght".to_string(), 500.0)]), "{:?}", coords(&set));
+    // A static family keeps no variations.
+    let inter = layout_uncached("Hi", &TextStyle::default(), &ParagraphStyle::default());
+    assert!(inter.glyphs.iter().all(|g| g.variations == 0));
+}
diff --git a/crates/track/src/camtrack/mod.rs b/crates/track/src/camtrack.rs
similarity index 90%
rename from crates/track/src/camtrack/mod.rs
rename to crates/track/src/camtrack.rs
index e8cd28da8..ea4f89a3f 100644
--- a/crates/track/src/camtrack/mod.rs
+++ b/crates/track/src/camtrack.rs
@@ -67,8 +67,9 @@ pub struct Track2D {
 }
 
 impl Track2D {
+    /// Exclusive end frame, saturated when the track exceeds the frame index range.
     pub fn end(&self) -> u32 {
-        self.start + self.pts.len() as u32
+        u32::try_from(self.pts.len()).ok().and_then(|n| self.start.checked_add(n)).unwrap_or(u32::MAX)
     }
     /// Position on frame `k` when the track covers it.
     pub fn at(&self, k: u32) -> Option<[f64; 2]> {
@@ -483,3 +484,52 @@ pub fn point_color(id: u32) -> [f32; 3] {
     // Bright, slightly desaturated.
     [0.25 + 0.75 * r, 0.25 + 0.75 * g, 0.25 + 0.75 * b]
 }
+
+#[cfg(test)]
+mod validation_tests {
+    use super::*;
+
+    fn tracks() -> CameraTracks {
+        CameraTracks { size: [1920.0, 1080.0], factor: 1.0, frame_duration: 1.0 / 30.0, frames: 3, ..Default::default() }
+    }
+
+    #[test]
+    fn track_end_saturates_instead_of_wrapping() {
+        assert_eq!(Track2D { start: u32::MAX, pts: vec![[0.0; 2]], ..Default::default() }.end(), u32::MAX);
+        assert_eq!(Track2D { start: 3, pts: vec![[0.0; 2]; 2], ..Default::default() }.end(), 5);
+    }
+
+    #[test]
+    fn solve_rejects_large_frame_count_before_allocating() {
+        let t = CameraTracks { frames: u32::MAX, ..tracks() };
+        let error = solve(&t, &SolveSettings::default(), None).unwrap_err();
+        assert!(error.0.contains("frame or track count"));
+    }
+
+    #[test]
+    fn solve_rejects_overflowing_and_out_of_clip_tracks() {
+        for start in [u32::MAX, 2] {
+            let t = CameraTracks { tracks: vec![Track2D { start, pts: vec![[0.0; 2]; 3], ..Default::default() }], ..tracks() };
+            let error = solve(&t, &SolveSettings::default(), None).unwrap_err();
+            assert!(error.0.contains("frame range"));
+        }
+    }
+
+    #[test]
+    fn solve_rejects_non_finite_track_positions() {
+        let t = CameraTracks { tracks: vec![Track2D { pts: vec![[f32::NAN, 0.0]; 3], ..Default::default() }], ..tracks() };
+        let error = solve(&t, &SolveSettings::default(), None).unwrap_err();
+        assert!(error.0.contains("finite"));
+    }
+
+    #[test]
+    fn solve_rejects_invalid_dimensions_timing_and_scale() {
+        for t in [
+            CameraTracks { size: [f64::NAN, 1080.0], ..tracks() },
+            CameraTracks { frame_duration: 0.0, ..tracks() },
+            CameraTracks { factor: f64::INFINITY, ..tracks() },
+        ] {
+            assert!(solve(&t, &SolveSettings::default(), None).is_err());
+        }
+    }
+}
diff --git a/crates/track/src/camtrack/bundle.rs b/crates/track/src/camtrack/bundle.rs
index 077f04b71..e03341d14 100644
--- a/crates/track/src/camtrack/bundle.rs
+++ b/crates/track/src/camtrack/bundle.rs
@@ -10,9 +10,9 @@
 
 use rayon::prelude::*;
 
-use super::Distortion;
 use super::geometry::Pose;
-use super::linalg::*;
+use super::linalg::{M3, V3, add, cholesky_solve, dot, inv3, mm, mtv, mv, rodrigues, scale, skew, sub};
+use super::{Distortion, SolveError};
 
 /// A camera in the adjustment.
 #[derive(Clone, Copy, Debug, PartialEq)]
@@ -52,6 +52,7 @@ pub struct BaOpts {
     pub fixed: Vec<bool>,
     /// Huber threshold (pixels).
     pub huber: f64,
+    /// Maximum LM iterations (at most 1000).
     pub max_iter: usize,
     /// Adjust the shared radial distortion `(k1, k2)` too.
     pub distortion: bool,
@@ -76,21 +77,89 @@ fn huber(e2: f64, k: f64) -> f64 {
     if e2 <= k * k { e2 } else { 2.0 * k * e2.sqrt() - k * k }
 }
 
-/// Residual (pixels) of one observation, `None` behind the camera.
+// Bound the temporary systems before any input-sized allocation. Includes dense matrices
+// for the main system, trial copies and both Rayon phases, plus per-point/observation data.
+const MAX_BA_BYTES: usize = 256 * 1024 * 1024;
+const MAX_BA_CAMERAS: usize = 4096;
+const MAX_BA_POINTS: usize = 200_000;
+const MAX_BA_OBSERVATIONS: usize = 1_000_000;
+
+fn valid_camera(c: &BaCam) -> bool {
+    c.f.is_finite()
+        && c.f > 0.0
+        && c.pose.r.iter().flatten().chain(&c.pose.c).all(|v| v.is_finite())
+        && [c.dist.k1, c.dist.k2, c.dist.radius].iter().all(|v| v.is_finite())
+}
+
+fn validate(cams: &[BaCam], pts: &[V3], obs: &[BaObs], o: &BaOpts) -> Result<(), SolveError> {
+    if cams.len() > MAX_BA_CAMERAS || pts.len() > MAX_BA_POINTS || obs.len() > MAX_BA_OBSERVATIONS {
+        return Err(SolveError("bundle adjustment input exceeds the supported size".into()));
+    }
+    if !o.huber.is_finite() || o.huber <= 0.0 || o.max_iter > 1000 || matches!(o.focal, FocalMode::PerCamera(k) if !k.is_finite() || k < 0.0) {
+        return Err(SolveError("invalid bundle adjustment options".into()));
+    }
+    if cams.iter().any(|c| !valid_camera(c)) || pts.iter().flatten().any(|v| !v.is_finite()) {
+        return Err(SolveError("bundle adjustment cameras and points must be finite, with positive focal lengths".into()));
+    }
+    for ob in obs {
+        if cams.get(ob.cam as usize).is_none() || pts.get(ob.pt as usize).is_none() {
+            return Err(SolveError("bundle adjustment observation index is out of range".into()));
+        }
+        if ob.uv.iter().any(|v| !v.is_finite()) {
+            return Err(SolveError("bundle adjustment observations must be finite".into()));
+        }
+    }
+    Ok(())
+}
+
+fn matrix_len(n: usize, npts: usize, nobs: usize) -> Result<usize, SolveError> {
+    let threads = rayon::current_num_threads();
+    let build_workers = if n <= 700 && npts > 64 { threads.clamp(1, 16) } else { 0 };
+    let schur_workers = if n <= 1200 && npts >= 64 && threads > 1 { threads.clamp(1, 8) } else { 0 };
+    // The two worker phases do not coexist; allow the larger phase plus main/trial buffers.
+    let copies = 4 + build_workers.max(schur_workers);
+    let len = n.checked_mul(n);
+    let bytes = len
+        .and_then(|v| v.checked_add(n))
+        .and_then(|v| v.checked_mul(size_of::<f64>()))
+        .and_then(|v| v.checked_mul(copies))
+        .and_then(|v| npts.checked_mul(320).and_then(|p| v.checked_add(p)))
+        .and_then(|v| nobs.checked_mul(2 * 9 * size_of::<(usize, V3)>() + size_of::<BaObs>() + 2 * size_of::<u32>()).and_then(|p| v.checked_add(p)));
+    match (len, bytes) {
+        (Some(len), Some(bytes)) if bytes <= MAX_BA_BYTES => Ok(len),
+        _ => Err(SolveError("bundle adjustment exceeds its 256 MiB workspace budget; use fewer cameras or observations".into())),
+    }
+}
+
+/// Residual (pixels), or `None` for an invalid or behind-camera projection.
 pub fn residual(c: &BaCam, x: V3, uv: [f64; 2]) -> Option<[f64; 2]> {
+    if !valid_camera(c) || x.iter().chain(&uv).any(|v| !v.is_finite()) {
+        return None;
+    }
+    project_residual(c, x, uv)
+}
+
+fn project_residual(c: &BaCam, x: V3, uv: [f64; 2]) -> Option<[f64; 2]> {
     let p = c.pose.to_cam(x);
-    if p[2] <= 1e-9 {
+    if p[2] <= 1e-9 || p.iter().any(|v| !v.is_finite()) {
         return None;
     }
     let q = c.dist.distort([c.f * p[0] / p[2], c.f * p[1] / p[2]]);
-    Some([q[0] - uv[0], q[1] - uv[1]])
+    let r = [q[0] - uv[0], q[1] - uv[1]];
+    r.iter().all(|v| v.is_finite()).then_some(r)
 }
 
-/// Total robust cost.
-pub fn cost(cams: &[BaCam], pts: &[V3], obs: &[BaObs], o: &BaOpts) -> f64 {
+/// Total robust cost. Rejects invalid inputs before starting parallel evaluation.
+pub fn cost(cams: &[BaCam], pts: &[V3], obs: &[BaObs], o: &BaOpts) -> Result<f64, SolveError> {
+    validate(cams, pts, obs, o)?;
+    let c = validated_cost(cams, pts, obs, o);
+    if c.is_finite() { Ok(c) } else { Err(SolveError("bundle adjustment cost is not finite".into())) }
+}
+
+fn validated_cost(cams: &[BaCam], pts: &[V3], obs: &[BaObs], o: &BaOpts) -> f64 {
     let c: f64 = obs
         .par_iter()
-        .map(|ob| match residual(&cams[ob.cam as usize], pts[ob.pt as usize], ob.uv) {
+        .map(|ob| match cams.get(ob.cam as usize).zip(pts.get(ob.pt as usize)).and_then(|(c, x)| project_residual(c, *x, ob.uv)) {
             Some(r) => huber(r[0] * r[0] + r[1] * r[1], o.huber),
             None => BEHIND,
         })
@@ -174,16 +243,45 @@ fn cam_jac(l: &Layout, ci: usize, c: &BaCam, xc: V3, a: &[[f64; 3]; 2], p: [f64;
     }
 }
 
+/// Smooth per-camera log focal lengths in the normal equations.
+fn add_focal_prior(cams: &[BaCam], o: &BaOpts, l: &Layout, s_mat: &mut [f64], bc: &mut [f64]) {
+    let n = l.n;
+    // Focal prior.
+    if let FocalMode::PerCamera(k) = o.focal {
+        for i in 0..cams.len().saturating_sub(1) {
+            let r = k * (cams[i].f.ln() - cams[i + 1].f.ln());
+            let (a, b) = (l.fidx[i], l.fidx[i + 1]);
+            let ia = (a != usize::MAX).then_some(a);
+            let ib = (b != usize::MAX).then_some(b);
+            for (idx, g) in [(ia, k), (ib, -k)] {
+                let Some(x) = idx else { continue };
+                bc[x] -= g * r;
+                for (idy, h) in [(ia, k), (ib, -k)] {
+                    if let Some(y) = idy {
+                        s_mat[x * n + y] += g * h;
+                    }
+                }
+            }
+        }
+    }
+}
+
 /// Run Levenberg–Marquardt. `cams` and `pts` are updated in place.
-pub fn adjust(cams: &mut [BaCam], pts: &mut [V3], obs: &[BaObs], o: &BaOpts) -> BaReport {
+/// Invalid inputs or workspaces exceeding 256 MiB return an error before mutation.
+pub fn adjust(cams: &mut [BaCam], pts: &mut [V3], obs: &[BaObs], o: &BaOpts) -> Result<BaReport, SolveError> {
+    validate(cams, pts, obs, o)?;
     let l = layout(cams.len(), o);
+    let matrix_len = matrix_len(l.n, pts.len(), obs.len())?;
     let npts = pts.len();
     // Observations by point.
     let mut by_pt: Vec<Vec<u32>> = vec![vec![]; npts];
     for (i, ob) in obs.iter().enumerate() {
         by_pt[ob.pt as usize].push(i as u32);
     }
-    let mut cur = cost(cams, pts, obs, o);
+    let mut cur = validated_cost(cams, pts, obs, o);
+    if !cur.is_finite() {
+        return Err(SolveError("bundle adjustment cost is not finite".into()));
+    }
     let initial = cur;
     let t0 = web_time::Instant::now();
     let mut tries = 0usize;
@@ -191,7 +289,7 @@ pub fn adjust(cams: &mut [BaCam], pts: &mut [V3], obs: &[BaObs], o: &BaOpts) ->
     let mut lambda = 1e-4;
     let mut iters = 0;
     if l.n == 0 && o.fix_points {
-        return BaReport { initial_cost: initial, cost: cur, iterations: 0 };
+        return Ok(BaReport { initial_cost: initial, cost: cur, iterations: 0 });
     }
     let n = l.n;
     let parallel = n <= 700;
@@ -274,12 +372,12 @@ pub fn adjust(cams: &mut [BaCam], pts: &mut [V3], obs: &[BaObs], o: &BaOpts) ->
             let parts: Vec<(Vec<f64>, Vec<f64>, Vec<PtSys>)> = (0..chunks)
                 .into_par_iter()
                 .map(|t| {
-                    let (mut s, mut b) = (vec![0.0; n * n], vec![0.0; n]);
+                    let (mut s, mut b) = (vec![0.0; matrix_len], vec![0.0; n]);
                     let v = (t * per..((t + 1) * per).min(npts)).map(|j| build_point(j, &mut s, &mut b)).collect();
                     (s, b, v)
                 })
                 .collect();
-            let mut s = vec![0.0; n * n];
+            let mut s = vec![0.0; matrix_len];
             let mut b = vec![0.0; n];
             let mut sys = Vec::with_capacity(npts);
             for (ps, pb, pv) in parts {
@@ -293,29 +391,12 @@ pub fn adjust(cams: &mut [BaCam], pts: &mut [V3], obs: &[BaObs], o: &BaOpts) ->
             }
             (s, b, sys)
         } else {
-            let mut s = vec![0.0; n * n];
+            let mut s = vec![0.0; matrix_len];
             let mut b = vec![0.0; n];
             let sys = (0..npts).map(|j| build_point(j, &mut s, &mut b)).collect();
             (s, b, sys)
         };
-        // Focal prior.
-        if let FocalMode::PerCamera(k) = o.focal {
-            for i in 0..cams.len().saturating_sub(1) {
-                let r = k * (cams[i].f.ln() - cams[i + 1].f.ln());
-                let (a, b) = (l.fidx[i], l.fidx[i + 1]);
-                let ia = (a != usize::MAX).then_some(a);
-                let ib = (b != usize::MAX).then_some(b);
-                for (idx, g) in [(ia, k), (ib, -k)] {
-                    let Some(x) = idx else { continue };
-                    bc[x] -= g * r;
-                    for (idy, h) in [(ia, k), (ib, -k)] {
-                        if let Some(y) = idy {
-                            s_mat[x * n + y] += g * h;
-                        }
-                    }
-                }
-            }
-        }
+        add_focal_prior(cams, o, &l, &mut s_mat, &mut bc);
         let base_s = s_mat.clone();
         let base_bc = bc.clone();
         let mean_diag = ((0..n).map(|i| base_s[i * n + i]).sum::<f64>() / n.max(1) as f64).max(1e-12);
@@ -370,7 +451,7 @@ pub fn adjust(cams: &mut [BaCam], pts: &mut [V3], obs: &[BaObs], o: &BaOpts) ->
                     let parts: Vec<(Vec<f64>, Vec<f64>)> = (0..chunks)
                         .into_par_iter()
                         .map(|t| {
-                            let (mut ds, mut dr) = (vec![0.0; n * n], vec![0.0; n]);
+                            let (mut ds, mut dr) = (vec![0.0; matrix_len], vec![0.0; n]);
                             reduce(t * per..((t + 1) * per).min(npts), &mut ds, &mut dr);
                             (ds, dr)
                         })
@@ -424,7 +505,11 @@ pub fn adjust(cams: &mut [BaCam], pts: &mut [V3], obs: &[BaObs], o: &BaOpts) ->
                     *x = add(*x, mv(vi, b));
                 });
             }
-            let c2 = cost(&nc, &np, obs, o);
+            if nc.iter().any(|c| !valid_camera(c)) || np.iter().flatten().any(|v| !v.is_finite()) {
+                lambda *= 4.0;
+                continue;
+            }
+            let c2 = validated_cost(&nc, &np, obs, o);
             if c2.is_finite() && c2 < cur {
                 cams.copy_from_slice(&nc);
                 pts.copy_from_slice(&np);
@@ -443,7 +528,7 @@ pub fn adjust(cams: &mut [BaCam], pts: &mut [V3], obs: &[BaObs], o: &BaOpts) ->
                             t0.elapsed().as_secs_f64()
                         );
                     }
-                    return BaReport { initial_cost: initial, cost: cur, iterations: iters };
+                    return Ok(BaReport { initial_cost: initial, cost: cur, iterations: iters });
                 }
                 break;
             }
@@ -456,7 +541,7 @@ pub fn adjust(cams: &mut [BaCam], pts: &mut [V3], obs: &[BaObs], o: &BaOpts) ->
     if dbg {
         eprintln!("ba n={} pts={} obs={} iters={iters} tries={tries} {:.2}s cost {initial:.1} -> {cur:.1}", l.n, npts, obs.len(), t0.elapsed().as_secs_f64());
     }
-    BaReport { initial_cost: initial, cost: cur, iterations: iters }
+    Ok(BaReport { initial_cost: initial, cost: cur, iterations: iters })
 }
 
 #[cfg(test)]
@@ -464,6 +549,75 @@ mod tests {
     use super::*;
     use crate::camtrack::geometry::Rng;
 
+    fn test_camera() -> BaCam {
+        BaCam { pose: Pose::IDENTITY, f: 900.0, dist: Distortion::NONE }
+    }
+
+    #[test]
+    fn cost_rejects_invalid_observation_indices() {
+        for (cam, pt) in [(1, 0), (0, 1)] {
+            let obs = [BaObs { cam, pt, uv: [0.0; 2] }];
+            assert!(cost(&[test_camera()], &[[0.0, 0.0, 5.0]], &obs, &BaOpts::default()).is_err());
+        }
+    }
+
+    #[test]
+    fn adjust_rejects_invalid_observation_without_mutating_inputs() {
+        for (cam, pt) in [(1, 0), (0, 1)] {
+            let mut cams = [test_camera()];
+            let mut pts = [[0.0, 0.0, 5.0]];
+            let before = (cams, pts);
+            let obs = [BaObs { cam, pt, uv: [0.0; 2] }];
+            assert!(adjust(&mut cams, &mut pts, &obs, &BaOpts::default()).is_err());
+            assert_eq!((cams, pts), before);
+        }
+    }
+
+    #[test]
+    fn residual_rejects_non_finite_inputs_and_projection_overflow() {
+        let cam = test_camera();
+        assert!(residual(&cam, [0.0, 0.0, f64::NAN], [0.0; 2]).is_none());
+        assert!(residual(&cam, [0.0, 0.0, 5.0], [f64::INFINITY, 0.0]).is_none());
+        for bad in [
+            BaCam { f: f64::NAN, ..cam },
+            BaCam { dist: Distortion { k1: f64::INFINITY, ..Distortion::NONE }, ..cam },
+            BaCam { pose: Pose { c: [f64::NAN; 3], ..Pose::IDENTITY }, ..cam },
+            BaCam { pose: Pose { r: [[f64::INFINITY; 3]; 3], ..Pose::IDENTITY }, ..cam },
+        ] {
+            assert!(residual(&bad, [0.0, 0.0, 5.0], [0.0; 2]).is_none());
+        }
+        assert!(residual(&cam, [f64::MAX, 0.0, 1.0], [0.0; 2]).is_none());
+    }
+
+    #[test]
+    fn adjustment_rejects_non_finite_points_observations_and_options() {
+        let cam = test_camera();
+        let pts = [[0.0, 0.0, 5.0]];
+        let obs = [BaObs { cam: 0, pt: 0, uv: [0.0; 2] }];
+        assert!(cost(&[cam], &[[f64::NAN, 0.0, 5.0]], &obs, &BaOpts::default()).is_err());
+        assert!(cost(&[cam], &pts, &[BaObs { uv: [f64::NAN; 2], ..obs[0] }], &BaOpts::default()).is_err());
+        for opts in [
+            BaOpts { huber: f64::NAN, ..Default::default() },
+            BaOpts { huber: 0.0, ..Default::default() },
+            BaOpts { focal: FocalMode::PerCamera(f64::INFINITY), ..Default::default() },
+            BaOpts { max_iter: usize::MAX, ..Default::default() },
+        ] {
+            let mut trial_pts = pts;
+            assert!(adjust(&mut [cam], &mut trial_pts, &obs, &opts).is_err());
+        }
+    }
+
+    #[test]
+    fn matrix_workspace_is_checked_and_bounded_before_allocation() {
+        assert!(matrix_len(usize::MAX, 0, 0).is_err());
+        assert!(matrix_len(1, usize::MAX, 0).is_err());
+        assert!(matrix_len(1, 0, usize::MAX).is_err());
+        let mut cams = vec![test_camera(); 1000];
+        assert!(adjust(&mut cams, &mut [], &[], &BaOpts::default()).is_err());
+        assert!(matrix_len(6, 1000, 1000).is_ok());
+        assert!(matrix_len(955, 900, 160 * 900).is_ok());
+    }
+
     #[test]
     fn bundle_adjustment_converges_from_noise() {
         let mut rng = Rng(99);
@@ -493,7 +647,7 @@ mod tests {
         let mut fixed = vec![false; 6];
         fixed[0] = true;
         fixed[1] = true;
-        let rep = adjust(&mut cams, &mut pts, &obs, &BaOpts { fixed, max_iter: 50, ..Default::default() });
+        let rep = adjust(&mut cams, &mut pts, &obs, &BaOpts { fixed, max_iter: 50, ..Default::default() }).unwrap();
         let rms = (rep.cost / obs.len() as f64).sqrt();
         assert!(rms < 1e-4, "{rep:?}");
     }
diff --git a/crates/track/src/camtrack/geometry.rs b/crates/track/src/camtrack/geometry.rs
index 6956ac2b5..cc633a9c6 100644
--- a/crates/track/src/camtrack/geometry.rs
+++ b/crates/track/src/camtrack/geometry.rs
@@ -5,7 +5,10 @@
 //! All image points here are **normalised** (calibrated) coordinates `x = (u − c) / f`.
 //! A camera is `(R, C)` with `X_cam = R (X − C)`.
 
-use super::linalg::*;
+use super::linalg::{
+    I3, M3, V3, add, col, cross, det3, dot, from_cols, madd, mm, mscale, mt, mtv, mv, nearest_rotation, normalize, null_vector, outer, scale, sub, svd3,
+    sym_eigen,
+};
 
 /// A deterministic xorshift generator for RANSAC samples.
 pub struct Rng(pub u64);
@@ -244,6 +247,9 @@ pub fn reproj2(pose: &Pose, x: V3, o: [f64; 2]) -> Option<f64> {
 /// Pick the essential decomposition with the most points in front of both cameras; returns
 /// the second camera (the first is the identity) and that count.
 pub fn select_pose(cands: &[(M3, V3)], x1: &[[f64; 2]], x2: &[[f64; 2]]) -> Option<(Pose, usize)> {
+    if x1.len() != x2.len() || x1.is_empty() || x1.iter().chain(x2).flatten().any(|v| !v.is_finite()) {
+        return None;
+    }
     let mut best: Option<(Pose, usize)> = None;
     for (r, t) in cands {
         let p2 = Pose::from_rt(*r, *t);
@@ -361,6 +367,7 @@ pub fn procrustes(a: &[V3], b: &[V3]) -> Option<M3> {
 
 #[cfg(test)]
 mod tests {
+    use super::super::linalg::{log_rot, norm, rodrigues};
     use super::*;
 
     fn scene() -> (Vec<V3>, Pose) {
@@ -380,6 +387,14 @@ mod tests {
         [c[0] / c[2], c[1] / c[2]]
     }
 
+    #[test]
+    fn pose_selection_rejects_mismatched_or_non_finite_correspondences() {
+        let candidates = [(I3, [0.1, 0.0, 0.0])];
+        assert!(select_pose(&candidates, &[[0.0; 2]], &[]).is_none());
+        assert!(select_pose(&candidates, &[], &[[0.0; 2]]).is_none());
+        assert!(select_pose(&candidates, &[[f64::NAN, 0.0]], &[[0.0; 2]]).is_none());
+    }
+
     #[test]
     fn essential_recovers_relative_pose() {
         let (pts, p2) = scene();
diff --git a/crates/track/src/camtrack/solver.rs b/crates/track/src/camtrack/solver.rs
index a4e2c21e6..8e212127b 100644
--- a/crates/track/src/camtrack/solver.rs
+++ b/crates/track/src/camtrack/solver.rs
@@ -7,7 +7,7 @@ use rayon::prelude::*;
 
 use super::bundle::{self, BaCam, BaObs, BaOpts, FocalMode};
 use super::geometry::{self, Pose};
-use super::linalg::*;
+use super::linalg::{V3, add, log_rot, mm, mt, mtv, mv, norm, normalize, rodrigues, scale, slerp, sub, sym_eigen};
 use super::{CameraSolve, CameraTracks, Distortion, ShotType, SolveMethod, SolveSettings, SolvedFrame, SolvedPoint};
 use crate::fit::{Model, ransac};
 
@@ -42,13 +42,54 @@ struct Data {
     noise_bits: std::sync::atomic::AtomicU64,
 }
 
+// Input budgets apply before building the duplicated per-frame/per-track lookup tables.
+const MAX_SOLVE_FRAMES: usize = 100_000;
+const MAX_SOLVE_TRACKS: usize = 200_000;
+const MAX_SOLVE_OBSERVATIONS: usize = 2_000_000;
+
+fn validate_tracks(t: &CameraTracks) -> Result<(), SolveError> {
+    if t.frames as usize > MAX_SOLVE_FRAMES || t.tracks.len() > MAX_SOLVE_TRACKS {
+        return err("camera tracks exceed the supported frame or track count");
+    }
+    if t.size.iter().any(|v| !v.is_finite() || *v <= 0.0)
+        || !t.factor.is_finite()
+        || t.factor < 0.0
+        || !t.start.is_finite()
+        || !t.frame_duration.is_finite()
+        || t.frame_duration <= 0.0
+    {
+        return err("camera tracks have invalid dimensions, timing or analysis scale");
+    }
+    let mut count = 0usize;
+    for tr in &t.tracks {
+        count = count
+            .checked_add(tr.pts.len())
+            .filter(|n| *n <= MAX_SOLVE_OBSERVATIONS)
+            .ok_or_else(|| SolveError("camera tracks exceed the supported observation count".into()))?;
+        let end = u32::try_from(tr.pts.len()).ok().and_then(|n| tr.start.checked_add(n));
+        if end.is_none_or(|end| end > t.frames) {
+            return err("camera track extends beyond the clip's frame range");
+        }
+        if tr.pts.iter().flatten().any(|v| !v.is_finite()) {
+            return err("camera track positions must be finite");
+        }
+    }
+    Ok(())
+}
+
 impl Data {
-    fn new(t: &CameraTracks, deleted: &[u32]) -> Data {
+    fn new(t: &CameraTracks, deleted: &[u32]) -> Result<Data, SolveError> {
+        validate_tracks(t)?;
+        if deleted.len() > MAX_SOLVE_TRACKS {
+            return err("too many deleted camera track ids");
+        }
         let n = t.frames as usize;
         let c = [t.size[0] * 0.5, t.size[1] * 0.5];
         let del: HashSet<u32> = deleted.iter().copied().collect();
         let mut tracks = vec![];
-        let mut by_frame = vec![vec![]; n];
+        let mut by_frame = Vec::new();
+        by_frame.try_reserve_exact(n).map_err(|_| SolveError("not enough memory for camera track frames".into()))?;
+        by_frame.resize_with(n, Vec::new);
         for tr in t.tracks.iter().filter(|tr| !del.contains(&tr.id) && tr.pts.len() >= 3) {
             let ti = tracks.len() as u32;
             let pts: Vec<[f64; 2]> = tr.pts.iter().map(|p| [p[0] as f64 - c[0], p[1] as f64 - c[1]]).collect();
@@ -60,7 +101,7 @@ impl Data {
             tracks.push((tr.id, tr.start as usize, pts));
         }
         let noise = (0.5 * t.factor).max(0.5);
-        Data { n, w: t.size[0], tracks, by_frame, noise_bits: std::sync::atomic::AtomicU64::new(noise.to_bits()) }
+        Ok(Data { n, w: t.size[0], tracks, by_frame, noise_bits: std::sync::atomic::AtomicU64::new(noise.to_bits()) })
     }
     fn at(&self, ti: u32, k: usize) -> Option<[f64; 2]> {
         let (_, s, p) = &self.tracks[ti as usize];
@@ -174,10 +215,10 @@ impl Recon {
     }
 
     /// Bundle-adjust the cameras of `frames` (the first stays fixed) and their points.
-    fn adjust(&mut self, d: &Data, frames: &[usize], cfg: &Cfg, focal: FocalMode, iters: usize) -> f64 {
+    fn adjust(&mut self, d: &Data, frames: &[usize], cfg: &Cfg, focal: FocalMode, iters: usize) -> Result<f64, SolveError> {
         let (mut cams, mut pts, obs, ids) = self.observations(d, frames);
         if obs.is_empty() {
-            return f64::INFINITY;
+            return Ok(f64::INFINITY);
         }
         let mut fixed = vec![false; cams.len()];
         fixed[0] = true;
@@ -186,14 +227,14 @@ impl Recon {
             &mut pts,
             &obs,
             &BaOpts { focal, fix_points: false, fix_centers: cfg.kind == Kind::Tripod, fixed, huber: d.huber(), max_iter: iters, distortion: cfg.distortion },
-        );
+        )?;
         for (k, c) in frames.iter().zip(&cams) {
             self.cams.insert(*k, *c);
         }
         for (ti, x) in ids.iter().zip(&pts) {
             self.pts.insert(*ti, *x);
         }
-        rep.cost
+        Ok(rep.cost)
     }
 
     /// Mark observations above the inlier threshold as outliers; drop points left with fewer
@@ -302,8 +343,12 @@ impl Recon {
                 break;
             }
             let mut cams = vec![start];
-            bundle::adjust(&mut cams, &mut pts.clone(), &obs, &opts(d.inlier_thr() * 4.0));
-            bundle::adjust(&mut cams, &mut pts.clone(), &obs, &opts(d.huber()));
+            if bundle::adjust(&mut cams, &mut pts.clone(), &obs, &opts(d.inlier_thr() * 4.0)).is_err() {
+                return false;
+            }
+            if bundle::adjust(&mut cams, &mut pts.clone(), &obs, &opts(d.huber())).is_err() {
+                return false;
+            }
             let inl = obs.iter().filter(|o| bundle::residual(&cams[0], pts[o.pt as usize], o.uv).is_some_and(|r| r[0] * r[0] + r[1] * r[1] <= thr2)).count();
             if best.as_ref().is_none_or(|b| inl > b.0) {
                 best = Some((inl, cams[0]));
@@ -317,7 +362,9 @@ impl Recon {
         let keep: Vec<BaObs> =
             obs.iter().filter(|o| bundle::residual(&cam, pts[o.pt as usize], o.uv).is_some_and(|r| r[0] * r[0] + r[1] * r[1] <= thr2)).copied().collect();
         let mut cams = vec![cam];
-        bundle::adjust(&mut cams, &mut pts.clone(), &keep, &opts(d.huber()));
+        if bundle::adjust(&mut cams, &mut pts.clone(), &keep, &opts(d.huber())).is_err() {
+            return false;
+        }
         for o in &obs {
             let ok = bundle::residual(&cams[0], pts[o.pt as usize], o.uv).is_some_and(|r| r[0] * r[0] + r[1] * r[1] <= thr2);
             if !ok {
@@ -471,10 +518,11 @@ fn grow(d: &Data, kfs: &[usize], j: usize, init: &(Pose, HashMap<u32, V3>), f: f
     r.pts = init.1.clone();
     let inner = |r: &mut Recon, frames: &[usize]| {
         let focal = if cfg.per_frame_f && frames.len() > 2 { FocalMode::PerCamera(F_PRIOR) } else { FocalMode::Fixed };
-        r.adjust(d, frames, cfg, focal, 10);
+        r.adjust(d, frames, cfg, focal, 10)?;
         r.reject(d);
+        Ok::<(), SolveError>(())
     };
-    inner(&mut r, &[a, b]);
+    inner(&mut r, &[a, b]).ok()?;
     let order: Vec<usize> = kfs[1..j].iter().chain(&kfs[j + 1..]).copied().collect();
     let mut done = 0;
     for k in order {
@@ -491,11 +539,11 @@ fn grow(d: &Data, kfs: &[usize], j: usize, init: &(Pose, HashMap<u32, V3>), f: f
         done += 1;
         let frames: Vec<usize> = r.cams.keys().copied().collect();
         if done % 3 == 0 || frames.len() <= 6 {
-            inner(&mut r, &frames);
+            inner(&mut r, &frames).ok()?;
         }
     }
     let frames: Vec<usize> = r.cams.keys().copied().collect();
-    inner(&mut r, &frames);
+    inner(&mut r, &frames).ok()?;
     (r.cams.len() >= 2 && r.pts.len() >= 8).then_some(r)
 }
 
@@ -531,10 +579,10 @@ fn grow_tripod(d: &Data, kfs: &[usize], f: f64, cfg: &Cfg, cancel: Option<&Atomi
     r.triangulate(d, Kind::Tripod, 0.0, 20.0);
     let frames: Vec<usize> = r.cams.keys().copied().collect();
     let focal = if cfg.per_frame_f && frames.len() > 2 { FocalMode::PerCamera(F_PRIOR) } else { FocalMode::Fixed };
-    r.adjust(d, &frames, cfg, focal, 15);
+    r.adjust(d, &frames, cfg, focal, 15).ok()?;
     r.reject(d);
     r.triangulate(d, Kind::Tripod, 0.0, 1.0);
-    r.adjust(d, &frames, cfg, focal, 15);
+    r.adjust(d, &frames, cfg, focal, 15).ok()?;
     (r.cams.len() >= 2 && r.pts.len() >= 8).then_some(r)
 }
 
@@ -684,7 +732,7 @@ pub fn solve(tracks: &CameraTracks, s: &SolveSettings, cancel: Option<&AtomicBoo
     for pass in 0..2 {
         let und = (pass > 0).then(|| undistorted(tracks, &dist));
         let c = solve_core(und.as_ref().unwrap_or(tracks), s, cancel)?;
-        let d = Data::new(tracks, &s.deleted);
+        let d = Data::new(tracks, &s.deleted)?;
         d.set_noise(c.d.noise());
         let mut r = c.r;
         for cam in r.cams.values_mut() {
@@ -699,10 +747,10 @@ pub fn solve(tracks: &CameraTracks, s: &SolveSettings, cancel: Option<&AtomicBoo
         // The pinhole solve's outliers include the distorted frame edges: start from all
         // observations (the Huber loss keeps real outliers in check), then reject again.
         r.outliers.clear();
-        r.adjust(&d, &frames, &cfg, c.focal, 30);
+        r.adjust(&d, &frames, &cfg, c.focal, 30)?;
         r.outliers.clear();
         r.reject(&d);
-        r.adjust(&d, &frames, &cfg, c.focal, 30);
+        r.adjust(&d, &frames, &cfg, c.focal, 30)?;
         dist = r.cams[&frames[0]].dist;
         for cam in r.cams.values_mut() {
             cam.dist = dist;
@@ -742,7 +790,7 @@ pub fn solve(tracks: &CameraTracks, s: &SolveSettings, cancel: Option<&AtomicBoo
 }
 
 fn solve_core(tracks: &CameraTracks, s: &SolveSettings, cancel: Option<&AtomicBool>) -> Result<Core, SolveError> {
-    let d = Data::new(tracks, &s.deleted);
+    let d = Data::new(tracks, &s.deleted)?;
     if d.n < 2 {
         return err("the clip must be at least two frames long");
     }
@@ -848,7 +896,7 @@ fn solve_core(tracks: &CameraTracks, s: &SolveSettings, cancel: Option<&AtomicBo
     lap("tripod");
     // Keyframes: adjust with the focal length free, reject, re-triangulate, adjust again.
     let kf_frames: Vec<usize> = r.cams.keys().copied().collect();
-    r.adjust(&d, &kf_frames, &cfg, focal, 40);
+    r.adjust(&d, &kf_frames, &cfg, focal, 40)?;
     r.reject(&d);
     // Re-estimate the tracking noise from the inlier residuals (robustly, from their median:
     // for 2D Gaussian noise of deviation σ the median distance is 1.1774 σ), then tighten the
@@ -876,9 +924,9 @@ fn solve_core(tracks: &CameraTracks, s: &SolveSettings, cancel: Option<&AtomicBo
         r.reject(&d);
     }
     r.triangulate(&d, kind, 1.0, 1.0);
-    r.adjust(&d, &kf_frames, &cfg, focal, 40);
+    r.adjust(&d, &kf_frames, &cfg, focal, 40)?;
     r.reject(&d);
-    r.adjust(&d, &kf_frames, &cfg, focal, 20);
+    r.adjust(&d, &kf_frames, &cfg, focal, 20)?;
     if cancelled() {
         return err("cancelled");
     }
@@ -910,7 +958,7 @@ fn solve_core(tracks: &CameraTracks, s: &SolveSettings, cancel: Option<&AtomicBo
     let all: Vec<usize> = r.cams.keys().copied().collect();
     r.reject(&d);
     if all.len() <= 160 {
-        r.adjust(&d, &all, &cfg, focal, 25);
+        r.adjust(&d, &all, &cfg, focal, 25)?;
         r.reject(&d);
     } else {
         // Points only (cameras fixed) would be cheap but the keyframe solution is already
diff --git a/crates/track/src/face.rs b/crates/track/src/face.rs
index 45c7c4baa..708a05c4f 100644
--- a/crates/track/src/face.rs
+++ b/crates/track/src/face.rs
@@ -186,9 +186,16 @@ fn to_layer(c: [f64; 2], b: f64, roll_deg: f64, q: [f64; 2]) -> [f64; 2] {
 
 /// Layer pixels → face frame.
 fn to_face(c: [f64; 2], b: f64, roll_deg: f64, p: [f64; 2]) -> [f64; 2] {
+    face_mapper(c, b, roll_deg)(p)
+}
+
+/// [`to_face`] with the rotation worked out once, for mapping many points.
+fn face_mapper(c: [f64; 2], b: f64, roll_deg: f64) -> impl Fn([f64; 2]) -> [f64; 2] {
     let (sn, cs) = roll_deg.to_radians().sin_cos();
-    let d = [(p[0] - c[0]) / b, (p[1] - c[1]) / b];
-    [cs * d[0] + sn * d[1], -sn * d[0] + cs * d[1]]
+    move |p| {
+        let d = [(p[0] - c[0]) / b, (p[1] - c[1]) / b];
+        [cs * d[0] + sn * d[1], -sn * d[0] + cs * d[1]]
+    }
 }
 
 /// A synthetic face's landmarks in layer pixels.
@@ -547,6 +554,32 @@ fn fit_from_face(face: &Face, topo: &Topology, offset: [f64; 2]) -> Option<FaceF
     Some(FaceFit { landmarks, detected, outline, center, height: b, roll })
 }
 
+/// Find the first skin pixel in successive rings around the predicted center.
+fn nearest_skin(skin: &[bool], size: (usize, usize), center: (usize, usize), radius: i64) -> Option<(usize, usize)> {
+    let (w, h) = size;
+    let (ci, cj) = center;
+    for r in 0..radius {
+        for dj in -r..=r {
+            for di in -r..=r {
+                if di.abs() != r && dj.abs() != r {
+                    continue;
+                }
+                let (i, j) = (ci as i64 + di, cj as i64 + dj);
+                if i >= 0 && j >= 0 && (i as usize) < w && (j as usize) < h && skin[j as usize * w + i as usize] {
+                    return Some((i as usize, j as usize));
+                }
+            }
+        }
+    }
+    None
+}
+
+struct FaceGeometry {
+    center: [f64; 2],
+    height: f64,
+    roll: f64,
+}
+
 /// A pixel window of a frame in layer coordinates.
 struct Window {
     x0: i64,
@@ -578,6 +611,44 @@ impl Window {
     }
 }
 
+/// Per pixel of a `w × h` window: not skin and inside `poly` (even-odd rule, same comparisons as
+/// [`crate::mask::inside_polygon`] at `layer(i, j)`). A scanline crosses the polygon at the same
+/// edges for every pixel of a row, so the crossings are found once per row and each pixel's
+/// parity follows from how many lie right of it.
+fn non_skin_inside(poly: &[[f64; 2]], skin: &[bool], layer: impl Fn(usize, usize) -> [f64; 2], w: usize, h: usize) -> Vec<bool> {
+    let mut feat = vec![false; w * h];
+    let n = poly.len();
+    if n < 3 {
+        return feat;
+    }
+    let mut xs: Vec<f64> = Vec::with_capacity(n);
+    for j in 0..h {
+        let y = layer(0, j)[1];
+        xs.clear();
+        let mut prev = poly[n - 1];
+        for &cur in poly {
+            let (a, b) = (cur, prev);
+            if (a[1] > y) != (b[1] > y) {
+                xs.push((b[0] - a[0]) * (y - a[1]) / (b[1] - a[1]) + a[0]);
+            }
+            prev = cur;
+        }
+        if xs.is_empty() {
+            continue;
+        }
+        xs.sort_by(f64::total_cmp);
+        let mut left = 0;
+        for i in 0..w {
+            let x = layer(i, j)[0];
+            while left < xs.len() && xs[left] <= x {
+                left += 1;
+            }
+            feat[j * w + i] = (xs.len() - left) % 2 == 1 && !skin[j * w + i];
+        }
+    }
+    feat
+}
+
 fn median(v: &mut [f32]) -> f32 {
     v.sort_by(f32::total_cmp);
     v[v.len() / 2]
@@ -752,6 +823,53 @@ impl FaceTracker {
         Some(fit)
     }
 
+    /// Connected dark features inside the fitted face, in normalized face coordinates.
+    fn feature_blobs(&self, frame: &Frame, win: &Window, skin: &[bool], luma: &[f32], outline: &[[f64; 2]], geometry: FaceGeometry) -> Vec<Blob> {
+        let FaceGeometry { center, height: b, roll } = geometry;
+        let (w, h) = (win.w, win.h);
+        // Non-skin components inside the face outline (shrunk a little: anti-aliased edges).
+        let inner: Vec<[f64; 2]> = outline.iter().map(|p| [center[0] + 0.9 * (p[0] - center[0]), center[1] + 0.9 * (p[1] - center[1])]).collect();
+        let feat = non_skin_inside(&inner, skin, |i, j| win.layer(frame, i, j), w, h);
+        let min_area = (0.0006 * b * b).max(2.0) as usize;
+        let mut seen = vec![false; w * h];
+        let mut blobs: Vec<Blob> = vec![];
+        let skin_luma = self.skin.med[0] as f64;
+        let to_face = face_mapper(center, b, roll);
+        for j0 in 0..h {
+            for i0 in 0..w {
+                if !feat[j0 * w + i0] || seen[j0 * w + i0] {
+                    continue;
+                }
+                let mut st = vec![(i0, j0)];
+                seen[j0 * w + i0] = true;
+                let mut pts = vec![];
+                while let Some((i, j)) = st.pop() {
+                    let q = to_face(win.layer(frame, i, j));
+                    pts.push((q, skin_luma - luma[j * w + i] as f64));
+                    for dj in -1i64..=1 {
+                        for di in -1i64..=1 {
+                            let (a, c) = (i as i64 + di, j as i64 + dj);
+                            if a < 0 || c < 0 || a as usize >= w || c as usize >= h {
+                                continue;
+                            }
+                            let (a, c) = (a as usize, c as usize);
+                            if feat[c * w + a] && !seen[c * w + a] {
+                                seen[c * w + a] = true;
+                                st.push((a, c));
+                            }
+                        }
+                    }
+                }
+                if pts.len() >= min_area {
+                    let n = pts.len() as f64;
+                    let centroid = [pts.iter().map(|p| p.0[0]).sum::<f64>() / n, pts.iter().map(|p| p.0[1]).sum::<f64>() / n];
+                    blobs.push(Blob { pts, centroid });
+                }
+            }
+        }
+        blobs
+    }
+
     fn fit(&self, frame: &Frame) -> Option<FaceFit> {
         let pv = &self.prev;
         let b0 = pv.height;
@@ -769,22 +887,7 @@ impl FaceTracker {
         }
         // Seed: the skin pixel nearest the predicted centre.
         let (ci, cj) = win.cell(frame, pv.center)?;
-        let mut seed = None;
-        'search: for r in 0..(0.6 * b0).ceil() as i64 {
-            for dj in -r..=r {
-                for di in -r..=r {
-                    if di.abs() != r && dj.abs() != r {
-                        continue;
-                    }
-                    let (i, j) = (ci as i64 + di, cj as i64 + dj);
-                    if i >= 0 && j >= 0 && (i as usize) < w && (j as usize) < h && skin[j as usize * w + i as usize] {
-                        seed = Some((i as usize, j as usize));
-                        break 'search;
-                    }
-                }
-            }
-        }
-        let (si, sj) = seed?;
+        let (si, sj) = nearest_skin(&skin, (w, h), (ci, cj), (0.6 * b0).ceil() as i64)?;
         // Flood fill (4-connected).
         let mut comp = vec![false; w * h];
         let mut stack = vec![(si, sj)];
@@ -855,52 +958,7 @@ impl FaceTracker {
             roll += 180.0;
         }
         let b = major;
-        // Non-skin components inside the face outline (shrunk a little: anti-aliased edges).
-        let inner: Vec<[f64; 2]> = outline.iter().map(|p| [center[0] + 0.9 * (p[0] - center[0]), center[1] + 0.9 * (p[1] - center[1])]).collect();
-        let mut feat = vec![false; w * h];
-        for j in 0..h {
-            for i in 0..w {
-                if !skin[j * w + i] && crate::mask::inside_polygon(&inner, win.layer(frame, i, j)) {
-                    feat[j * w + i] = true;
-                }
-            }
-        }
-        let min_area = (0.0006 * b * b).max(2.0) as usize;
-        let mut seen = vec![false; w * h];
-        let mut blobs: Vec<Blob> = vec![];
-        let skin_luma = self.skin.med[0] as f64;
-        for j0 in 0..h {
-            for i0 in 0..w {
-                if !feat[j0 * w + i0] || seen[j0 * w + i0] {
-                    continue;
-                }
-                let mut st = vec![(i0, j0)];
-                seen[j0 * w + i0] = true;
-                let mut pts = vec![];
-                while let Some((i, j)) = st.pop() {
-                    let q = to_face(center, b, roll, win.layer(frame, i, j));
-                    pts.push((q, skin_luma - luma[j * w + i] as f64));
-                    for dj in -1i64..=1 {
-                        for di in -1i64..=1 {
-                            let (a, c) = (i as i64 + di, j as i64 + dj);
-                            if a < 0 || c < 0 || a as usize >= w || c as usize >= h {
-                                continue;
-                            }
-                            let (a, c) = (a as usize, c as usize);
-                            if feat[c * w + a] && !seen[c * w + a] {
-                                seen[c * w + a] = true;
-                                st.push((a, c));
-                            }
-                        }
-                    }
-                }
-                if pts.len() >= min_area {
-                    let n = pts.len() as f64;
-                    let centroid = [pts.iter().map(|p| p.0[0]).sum::<f64>() / n, pts.iter().map(|p| p.0[1]).sum::<f64>() / n];
-                    blobs.push(Blob { pts, centroid });
-                }
-            }
-        }
+        let blobs = self.feature_blobs(frame, &win, &skin, &luma, &outline, FaceGeometry { center, height: b, roll });
         // Match components to features near their expected positions.
         let ex = &self.expect;
         let mean_of = |ids: &[usize]| {
@@ -1174,6 +1232,35 @@ mod tests {
         assert!(err < 0.06 * 50.0, "max error {err}");
     }
 
+    #[test]
+    fn row_crossings_match_the_point_in_polygon_test() {
+        let (w, h) = (97, 83);
+        let off = [13.0, 7.0];
+        let layer = |i: usize, j: usize| [(20 + i) as f64 + 0.5 - off[0] + 0.25, (11 + j) as f64 + 0.5 - off[1]];
+        let star: Vec<[f64; 2]> = (0..48)
+            .map(|k| {
+                let a = k as f64 / 48.0 * std::f64::consts::TAU;
+                let r = 30.0 + 9.0 * (5.0 * a).sin() + 3.0 * (k % 3) as f64;
+                [50.0 + a.cos() * r, 40.0 + a.sin() * r * 1.3]
+            })
+            .collect();
+        // Vertices on pixel-centre rows and columns exercise the tie cases.
+        let tied: Vec<[f64; 2]> = vec![[10.0, 5.0], [70.0, 5.0], [70.0, 60.5], [40.0, 30.5], [10.0, 60.5], [10.0, 5.0]];
+        for poly in [star, tied, vec![[1.0, 1.0], [5.0, 5.0]]] {
+            let skin: Vec<bool> = (0..w * h).map(|i| (i * 7 + i / w) % 5 == 0).collect();
+            let got = non_skin_inside(&poly, &skin, layer, w, h);
+            let mut inside = 0;
+            for j in 0..h {
+                for i in 0..w {
+                    let want = !skin[j * w + i] && crate::mask::inside_polygon(&poly, layer(i, j));
+                    assert_eq!(got[j * w + i], want, "({i}, {j})");
+                    inside += want as usize;
+                }
+            }
+            assert!(inside > 0 || poly.len() < 3);
+        }
+    }
+
     #[test]
     fn tracks_a_moving_rotating_synthetic_face() {
         let (w, h) = (320, 240);
diff --git a/crates/track/src/roto/mod.rs b/crates/track/src/roto.rs
similarity index 96%
rename from crates/track/src/roto/mod.rs
rename to crates/track/src/roto.rs
index 305065d2c..0948d3fe0 100644
--- a/crates/track/src/roto/mod.rs
+++ b/crates/track/src/roto.rs
@@ -407,7 +407,9 @@ fn beta(img: &[[f32; 3]], free: &[bool], w: usize, h: usize) -> f64 {
 
 /// One min-cut over the `free` pixels; others keep `labels`. `prior`: P(foreground) per pixel
 /// and how much it weighs against the colour models.
-fn cut(img: &[[f32; 3]], w: usize, h: usize, labels: &mut [u8], free: &[bool], hard: &[u8], fg: &Gmm, bg: &Gmm, prior: Option<(&[f32], f64)>) {
+fn cut(img: &[[f32; 3]], size: (usize, usize), labels: &mut [u8], free: &[bool], hard: &[u8], models: (&Gmm, &Gmm), prior: Option<(&[f32], f64)>) {
+    let (w, h) = size;
+    let (fg, bg) = models;
     let mut idx = vec![u32::MAX; w * h];
     let mut nodes = vec![];
     for i in 0..w * h {
@@ -622,6 +624,36 @@ pub struct Prior {
     pub weight: f64,
 }
 
+/// Fit foreground/background colour models from strokes and the propagated matte.
+fn initial_models(rgb: &[[f32; 3]], hard: &[u8], fgs: &[bool], strokes: &[&Stroke], prior: Option<&Prior>, opts: &SegOpts, size: (usize, usize)) -> (Gmm, Gmm) {
+    let (w, h) = size;
+    // Initial colour models: the strokes (and the propagated matte).
+    match prior {
+        Some(p) => {
+            let fgc = samples(rgb, |i| (hard[i] == HARD_FG) || (hard[i] == 0 && p.soft[i] >= 0.5));
+            let bgc = samples(rgb, |i| (hard[i] == HARD_BG) || (hard[i] == 0 && p.soft[i] < 0.5));
+            let f = Gmm::fit(&fgc, COMPONENTS, MAX_SAMPLES);
+            let b = Gmm::fit(&bgc, COMPONENTS, MAX_SAMPLES);
+            (if f.is_empty() { p.fg.clone() } else { f }, if b.is_empty() { p.bg.clone() } else { b })
+        }
+        None => {
+            let fgc = samples(rgb, |i| hard[i] == HARD_FG);
+            let mut bgc = samples(rgb, |i| hard[i] == HARD_BG);
+            if bgc.is_empty() {
+                // No background strokes: what is far from the foreground strokes.
+                let d = matting::distance(fgs, w, h);
+                let r = strokes.iter().filter(|s| s.kind == StrokeKind::Fg).map(|s| s.radius).fold(1.0, f64::max) * opts.scale;
+                let far = (4.0 * r).max(0.25 * w.max(h) as f64) as f32;
+                bgc = samples(rgb, |i| d[i] > far);
+                if bgc.is_empty() {
+                    bgc = samples(rgb, |i| hard[i] != HARD_FG);
+                }
+            }
+            (Gmm::fit(&fgc, COMPONENTS, MAX_SAMPLES), Gmm::fit(&bgc, COMPONENTS, MAX_SAMPLES))
+        }
+    }
+}
+
 /// Segment a frame from its strokes (and a propagated prior): GrabCut iterations on a reduced
 /// copy, then a full-resolution cut in a band around the boundary.
 pub fn segment(img: &Image, strokes: &[&Stroke], prior: Option<&Prior>, opts: &SegOpts, refine_radius: f64) -> FrameSeg {
@@ -649,31 +681,7 @@ pub fn segment(img: &Image, strokes: &[&Stroke], prior: Option<&Prior>, opts: &S
     let soft_prior: Option<Vec<f32>> =
         prior.map(|p| if p.weight > PRIOR { p.soft.clone() } else { matting::gauss(&p.soft, w, h, (opts.search_radius * opts.scale / 4.0).max(1.0)) });
     let pw = prior.map_or(PRIOR, |p| p.weight);
-    // Initial colour models: the strokes (and the propagated matte).
-    let (fg0, bg0) = match prior {
-        Some(p) => {
-            let fgc = samples(&rgb, |i| (hard[i] == HARD_FG) || (hard[i] == 0 && p.soft[i] >= 0.5));
-            let bgc = samples(&rgb, |i| (hard[i] == HARD_BG) || (hard[i] == 0 && p.soft[i] < 0.5));
-            let f = Gmm::fit(&fgc, COMPONENTS, MAX_SAMPLES);
-            let b = Gmm::fit(&bgc, COMPONENTS, MAX_SAMPLES);
-            (if f.is_empty() { p.fg.clone() } else { f }, if b.is_empty() { p.bg.clone() } else { b })
-        }
-        None => {
-            let fgc = samples(&rgb, |i| hard[i] == HARD_FG);
-            let mut bgc = samples(&rgb, |i| hard[i] == HARD_BG);
-            if bgc.is_empty() {
-                // No background strokes: what is far from the foreground strokes.
-                let d = matting::distance(&fgs, w, h);
-                let r = strokes.iter().filter(|s| s.kind == StrokeKind::Fg).map(|s| s.radius).fold(1.0, f64::max) * opts.scale;
-                let far = (4.0 * r).max(0.25 * w.max(h) as f64) as f32;
-                bgc = samples(&rgb, |i| d[i] > far);
-                if bgc.is_empty() {
-                    bgc = samples(&rgb, |i| hard[i] != HARD_FG);
-                }
-            }
-            (Gmm::fit(&fgc, COMPONENTS, MAX_SAMPLES), Gmm::fit(&bgc, COMPONENTS, MAX_SAMPLES))
-        }
-    };
+    let (fg0, bg0) = initial_models(&rgb, &hard, &fgs, strokes, prior, opts, (w, h));
     let iters = if opts.best { 4 } else { 3 };
     let work = if opts.best { 960 } else { 480 };
     let f = w.max(h).div_ceil(work).max(1);
@@ -721,7 +729,7 @@ pub fn segment(img: &Image, strokes: &[&Stroke], prior: Option<&Prior>, opts: &S
         };
         let free = vec![true; cw * ch];
         for it in 0..iters {
-            cut(&crgb, cw, ch, &mut cl, &free, &chard, &fgm, &bgm, cprior.as_deref().map(|c| (c, pw)));
+            cut(&crgb, (cw, ch), &mut cl, &free, &chard, (&fgm, &bgm), cprior.as_deref().map(|c| (c, pw)));
             if it + 1 < iters {
                 let (a, b) = fit_models(&crgb, &cl);
                 if !a.is_empty() && !b.is_empty() {
@@ -743,11 +751,11 @@ pub fn segment(img: &Image, strokes: &[&Stroke], prior: Option<&Prior>, opts: &S
         let sd = matting::signed_distance(&labels, w, h);
         let band = f as f32 + 1.5;
         let free: Vec<bool> = sd.iter().map(|d| d.abs() <= band).collect();
-        cut(&rgb, w, h, &mut labels, &free, &hard, &fgm, &bgm, soft_prior.as_deref().map(|c| (c, pw)));
+        cut(&rgb, (w, h), &mut labels, &free, &hard, (&fgm, &bgm), soft_prior.as_deref().map(|c| (c, pw)));
     } else {
         let free = vec![true; w * h];
         for it in 0..iters {
-            cut(&rgb, w, h, &mut labels, &free, &hard, &fgm, &bgm, soft_prior.as_deref().map(|c| (c, pw)));
+            cut(&rgb, (w, h), &mut labels, &free, &hard, (&fgm, &bgm), soft_prior.as_deref().map(|c| (c, pw)));
             if it + 1 < iters {
                 let (a, b) = fit_models(&rgb, &labels);
                 if !a.is_empty() && !b.is_empty() {
@@ -843,7 +851,7 @@ pub fn propagate(prev_img: &Image, prev: &FrameSeg, next_img: &Image, strokes: &
     let hard = vec![0u8; w * h];
     let soft = matting::gauss(&prior.soft, w, h, (r as f64 / 4.0).max(1.0));
     let (fg, bg) = if prev.fg.is_empty() || prev.bg.is_empty() { fit_models(&rgb, &labels) } else { (prev.fg.clone(), prev.bg.clone()) };
-    cut(&rgb, w, h, &mut labels, &free, &hard, &fg, &bg, Some((&soft, PRIOR)));
+    cut(&rgb, (w, h), &mut labels, &free, &hard, (&fg, &bg), Some((&soft, PRIOR)));
     let seeds = core_of(&prior.soft, w, h, r as f64);
     clean(&mut labels, &seeds, &vec![false; w * h], w, h);
     finish(next_img, &rgb, labels, strokes, Some(&prior.refine), opts, refine_radius)
diff --git a/crates/track/src/roto/matting.rs b/crates/track/src/roto/matting.rs
index 439d9c43e..cb22b680a 100644
--- a/crates/track/src/roto/matting.rs
+++ b/crates/track/src/roto/matting.rs
@@ -200,7 +200,8 @@ pub fn guided_filter(img: &[[f32; 3]], p: &[f32], w: usize, h: usize, r: usize,
 /// (K. He, J. Sun and X. Tang, "Fast Matting Using Large Kernel Matting Laplacian Matrices",
 /// CVPR 2010): `(L·x)ᵢ = Σ_{k∋i} (xᵢ − a_kᵀIᵢ − b_k)` with `(a_k, b_k)` the ridge-regression
 /// fit of `x` to the colours in window k.
-pub fn closed_form(img: &[[f32; 3]], init: &[f32], known: &[bool], w: usize, h: usize, r: usize, eps: f32, iters: usize) -> Vec<f32> {
+pub fn closed_form(img: &[[f32; 3]], init: &[f32], known: &[bool], size: (usize, usize), r: usize, eps: f32, iters: usize) -> Vec<f32> {
+    let (w, h) = size;
     let n = w * h;
     if n == 0 || known.iter().all(|k| *k) {
         return init.to_vec();
diff --git a/crates/track/src/roto/refine.rs b/crates/track/src/roto/refine.rs
index 2a498e286..71f9261b2 100644
--- a/crates/track/src/roto/refine.rs
+++ b/crates/track/src/roto/refine.rs
@@ -123,7 +123,7 @@ pub fn matte_alpha(
             q[j] = if band[j] { q[j].clamp(0.0, 1.0) } else { cp[j] };
         }
         if p.higher_quality {
-            q = matting::closed_form(&cimg, &q, &outside, cw, ch, 1, 1e-5 * (1.0 + p.smooth.max(0.0)) as f32, 50);
+            q = matting::closed_form(&cimg, &q, &outside, (cw, ch), 1, 1e-5 * (1.0 + p.smooth.max(0.0)) as f32, 50);
         }
         // Refine Edge Matte adjustments.
         if p.smooth > 1.0 {
@@ -177,7 +177,8 @@ pub fn matte_alpha(
 /// Decontaminate edge colours of `rgb` in place for the matte `alpha` (see
 /// [`matting::decontaminate`]); returns the decontamination map. `band`: the Refine Edge band
 /// (pixels where decontamination always applies).
-pub fn decontaminate(rgb: &mut [[f32; 3]], alpha: &[f32], band: &[u8], w: usize, h: usize, p: &MatteParams, band_radius: f64, scale: f64) -> Vec<f32> {
+pub fn decontaminate(rgb: &mut [[f32; 3]], alpha: &[f32], band: &[u8], size: (usize, usize), p: &MatteParams, band_radius: f64, scale: f64) -> Vec<f32> {
+    let (w, h) = size;
     if !p.decontaminate {
         return vec![0.0; w * h];
     }
diff --git a/crates/track/src/roto/tests.rs b/crates/track/src/roto/tests.rs
index 3c4645cb2..92c7bec04 100644
--- a/crates/track/src/roto/tests.rs
+++ b/crates/track/src/roto/tests.rs
@@ -246,7 +246,7 @@ fn refine_edge_recovers_a_soft_edge_and_decontaminates() {
     assert!(frac as f64 > 0.6 * n as f64, "{frac}/{n} fractional");
     // Decontamination: edge pixels' colour is the foreground's, not a blue blend.
     let mut col = rgb.clone();
-    let map = decontaminate(&mut col, &a, &seg.refine, W as usize, H as usize, &p, 9.0, 1.0);
+    let map = decontaminate(&mut col, &a, &seg.refine, (W as usize, H as usize), &p, 9.0, 1.0);
     let (mut blue_before, mut blue_after, mut m) = (0.0f64, 0.0f64, 0usize);
     for i in 0..a.len() {
         if a[i] > 0.2 && a[i] < 0.8 {
diff --git a/crates/ui-egui/Cargo.toml b/crates/ui-egui/Cargo.toml
index ede0196e2..b1e281627 100644
--- a/crates/ui-egui/Cargo.toml
+++ b/crates/ui-egui/Cargo.toml
@@ -11,6 +11,7 @@ workspace = true
 
 [dependencies]
 craft-ui = { workspace = true }
+craft-quit = { workspace = true, features = ["egui"] }
 effectcraft-time = { workspace = true }
 effectcraft-geom = { workspace = true }
 effectcraft-color = { workspace = true }
diff --git a/crates/ui-egui/src/app.rs b/crates/ui-egui/src/app.rs
new file mode 100644
index 000000000..115c5f33a
--- /dev/null
+++ b/crates/ui-egui/src/app.rs
@@ -0,0 +1,168 @@
+use super::clock::AppClock;
+use super::hooks::Hooks;
+use super::state::{FrameWindow, PlaybackPass, ShotTarget};
+use super::*;
+
+mod clipboard;
+mod files;
+mod frame;
+mod gpu;
+mod input;
+mod playback;
+mod prefetch;
+mod prefs;
+mod screenshot;
+mod viewer_frames;
+mod window;
+
+#[cfg(test)]
+pub(crate) use screenshot::{MAX_PENDING_SHOTS, SCREENSHOT_SETTLE_PASSES, SCREENSHOT_SETTLE_S, SCREENSHOT_TIMEOUT_S};
+
+impl EffectcraftApp {
+    /// Build the app around `session`.
+    /// Loads and applies the workspaces saved in the session's config directory (a failed load is reported in
+    /// `ui.status`), initializes the default UI, playback and render state, and registers the frontend's commands as
+    /// shortcutable `UiCommand`s on the session.
+    pub fn new(session: Session) -> Self {
+        let mut ui = UiState::default();
+        let workspace_store = workspace_state::WorkspaceStore::load(session.config.as_deref(), &mut ui);
+        EffectcraftApp {
+            session,
+            ui,
+            workspace_store,
+            tokens: Tokens::for_kind(Default::default()),
+            auto: Default::default(),
+            frames: Frames::default(),
+            playback: Playback::default(),
+            dialog: None,
+            hooks: Hooks::default(),
+            fps: 60.0,
+            clock: AppClock::default(),
+            now: 0.0,
+            last_time: 0.0,
+            styled: false,
+            fonts_ready: false,
+            styled_language: "",
+            focused: true,
+            input_active: false,
+            last_pointer_down: false,
+            draw_geom: None,
+            geometry_epoch: 0,
+            ime_tracker: egui::ImeContextTracker::new(),
+            ui_pass_seq: 0,
+            want_paint: false,
+            synthetic_in_flight: false,
+            synthetic_in_flight_events: vec![],
+            last_viewer_scale: None,
+            control_rx: None,
+            deferred: vec![],
+            synthetic: vec![],
+            forwarded: ForwardedInput::default(),
+            input_waiters: vec![],
+            job_waiters: vec![],
+            pending_screenshots: vec![],
+            shot_bytes: 0,
+            last_activity: (0.0, 0),
+            last_edit: (0.0, 0),
+            toast: None,
+            viewer_tex: None,
+            passive_tex: std::collections::HashMap::new(),
+            viewer_native: None,
+            viewer_shown: None,
+            viewer_image: None,
+            viewer_readback: Default::default(),
+            wgpu: None,
+            gpu: None,
+            gpu_checked: false,
+            gpu_failures: None,
+            gpu_failure_applied: None,
+            device_lost_close: None,
+            dialog_answers: std::sync::mpsc::channel(),
+            file_dialogs: FileDialogsUp::default(),
+            command_inbox: None,
+            pointer_comp: None,
+            dialog_state: Default::default(),
+            integrated_titlebar: false,
+            audio: None,
+            scrub: None,
+            meter: Default::default(),
+            expression_diagnostics: Default::default(),
+            waveforms: Default::default(),
+            last_reveal: None,
+            applied_prefs: None,
+            recovery: None,
+            dock_rects: vec![],
+            native_viewports: vec![],
+            unpublished_viewports: vec![],
+            pending_panel_raise: None,
+            home_thumbs: Default::default(),
+            home_thumb_saved: None,
+            window_title: String::new(),
+            template_thumbs: Default::default(),
+            template_list: None,
+            updates_rt: updates_ui::Runtime::default(),
+        }
+        .with_ui_commands()
+    }
+
+    /// Offer the frontend's commands (tools, timeline navigation…) for keyboard shortcuts.
+    fn with_ui_commands(mut self) -> Self {
+        let cmds = menus::UI_COMMANDS
+            .iter()
+            .map(|c| effectcraft_engine::shortcuts::UiCommand { id: c.id.into(), label: c.label.into(), shortcut: c.shortcut.map(str::to_string) })
+            .collect();
+        self.session.set_ui_commands(cmds);
+        self
+    }
+
+    pub fn with_control(mut self, rx: Receiver<ControlRequest>) -> Self {
+        self.control_rx = Some(rx);
+        self
+    }
+}
+
+impl eframe::App for EffectcraftApp {
+    fn on_exit(&mut self) {
+        self.save_workspace_state();
+        // Clean exit: no crash recovery next launch (unless the graphics device was lost with
+        // unsaved changes, which are in the auto-save it offers).
+        if self.device_lost_close != Some(true) {
+            self.session.end_recovery();
+        }
+    }
+
+    /// Feed pending synthetic input into `raw_input` only once fonts are ready (so a non-drawing pass never consumes
+    /// a batch), then prepare pointer wrapping; ending a numeric scrub clears the history merge key so the next edit
+    /// starts a new undo step.
+    fn raw_input_hook(&mut self, ctx: &egui::Context, raw_input: &mut egui::RawInput) {
+        raw_input.events.append(&mut self.forwarded.events);
+        raw_input.dropped_files.append(&mut self.forwarded.files);
+        let injected = self.synthetic_in_flight || !self.synthetic.is_empty();
+        // Only a pass that can draw may receive synthetic input: `Context::run_ui` applies
+        // everything the hook feeds to its input state, so a pass that cannot draw (fonts still
+        // installing) would consume a batch it could not put back — putting it back would apply
+        // the click/key state twice. The queue waits here for the first pass that draws.
+        if self.fonts_ready {
+            self.feed_synthetic(raw_input);
+        }
+        if pointer_wrap::prepare_input(ctx, raw_input, injected) {
+            self.session.history.merge_key = None;
+        }
+    }
+
+    /// The logic-only tick: run `tick`, close the IME pass with `finish_ime_logic` and, last, hand a close to the
+    /// platform quit (`panels::unsaved::quit_on_close`). It does not read pass-time
+    /// input state (events, pointer and time are stale here), only the viewport information eframe refreshed.
+    fn logic(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame) {
+        // Never `ctx.input(|i| i.time)` here: `Context::run_logic` leaves events, pointer state and
+        // time at the previous full pass's values (only the viewport information is refreshed).
+        self.tick(ctx, frame);
+        self.finish_ime_logic(ctx);
+        crate::panels::unsaved::quit_on_close(ctx);
+    }
+
+    /// Draw one UI pass through `draw`.
+    fn ui(&mut self, ui: &mut egui::Ui, frame: &mut eframe::Frame) {
+        self.draw(ui, frame);
+    }
+}
diff --git a/crates/ui-egui/src/app/clipboard.rs b/crates/ui-egui/src/app/clipboard.rs
new file mode 100644
index 000000000..23b5080e0
--- /dev/null
+++ b/crates/ui-egui/src/app/clipboard.rs
@@ -0,0 +1,63 @@
+#[cfg(test)]
+use super::*;
+
+/// Put `width` × `height` straight-alpha RGBA8 pixels on the system clipboard (Composition ▸ Copy
+/// Frame to Clipboard). The pixel count is checked first: egui's image constructor panics on a
+/// size that doesn't match its buffer.
+pub(super) fn copy_image(ctx: &egui::Context, width: u32, height: u32, rgba: &[u8]) -> Result<(), String> {
+    let (w, h) = (width as usize, height as usize);
+    if w == 0 || h == 0 || w.checked_mul(h).and_then(|n| n.checked_mul(4)) != Some(rgba.len()) {
+        return Err(format!("cannot copy a malformed {width}×{height} image to the clipboard"));
+    }
+    ctx.copy_image(egui::ColorImage::from_rgba_unmultiplied([w, h], rgba));
+    Ok(())
+}
+
+#[cfg(test)]
+mod copy_frame_tests {
+    use super::*;
+
+    fn copied(output: &egui::FullOutput) -> Vec<&egui::ColorImage> {
+        output
+            .platform_output
+            .commands
+            .iter()
+            .filter_map(|c| match c {
+                egui::OutputCommand::CopyImage(image) => Some(image),
+                _ => None,
+            })
+            .collect()
+    }
+
+    /// Composition ▸ Copy Frame to Clipboard puts the rendered frame on the system clipboard.
+    #[test]
+    fn copy_frame_puts_the_frame_on_the_clipboard() {
+        let mut session = Session::default();
+        session.execute("comp.new", json!({"name": "Copy", "width": 8, "height": 6, "duration": 1})).unwrap();
+        session.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap();
+        let mut app = EffectcraftApp::new(session);
+        let ctx = egui::Context::default();
+        let mut output = ctx.run_ui(egui::RawInput::default(), |ui| {
+            crate::menus::invoke(&mut app, ui.ctx(), "comp.copyFrame", json!({})).unwrap();
+            app.handle_events(ui.ctx());
+        });
+        output.textures_delta.clear();
+        let images = copied(&output);
+        assert_eq!(images.len(), 1);
+        assert_eq!(images[0].size, [8, 6]);
+        assert!(images[0].pixels.iter().all(|p| *p == egui::Color32::from_rgb(255, 0, 0)));
+    }
+
+    /// A malformed image never reaches egui's panicking constructor.
+    #[test]
+    fn a_malformed_image_is_an_error_not_a_crash() {
+        let ctx = egui::Context::default();
+        let mut output = ctx.run_ui(egui::RawInput::default(), |ui| {
+            assert!(copy_image(ui.ctx(), 4, 4, &[0; 10]).is_err());
+            assert!(copy_image(ui.ctx(), 0, 4, &[]).is_err());
+            assert!(copy_image(ui.ctx(), u32::MAX, u32::MAX, &[0; 4]).is_err());
+        });
+        output.textures_delta.clear();
+        assert!(copied(&output).is_empty());
+    }
+}
diff --git a/crates/ui-egui/src/app/files.rs b/crates/ui-egui/src/app/files.rs
new file mode 100644
index 000000000..b1beab972
--- /dev/null
+++ b/crates/ui-egui/src/app/files.rs
@@ -0,0 +1,11 @@
+use super::{Dialog, EffectcraftApp};
+
+impl EffectcraftApp {
+    /// Show the crash-recovery dialog for a previous run that didn't exit cleanly.
+    pub fn offer_recovery(&mut self, r: effectcraft_engine::autosave::Recovery) {
+        if r.autosave.is_some() {
+            self.recovery = Some(r);
+            self.dialog = Some(Dialog::Recovery);
+        }
+    }
+}
diff --git a/crates/ui-egui/src/app/frame.rs b/crates/ui-egui/src/app/frame.rs
new file mode 100644
index 000000000..d41e0a9d0
--- /dev/null
+++ b/crates/ui-egui/src/app/frame.rs
@@ -0,0 +1,553 @@
+use super::clipboard::copy_image;
+use super::window::fit_window;
+use super::*;
+
+impl EffectcraftApp {
+    /// Completed, non-discarded UI passes since launch.
+    pub fn ui_passes(&self) -> u64 {
+        self.ui_pass_seq
+    }
+
+    // ---------------------------------------------------------------- control channel
+
+    pub(crate) fn raise_for_control(&mut self, ctx: &egui::Context) {
+        ctx.request_repaint();
+    }
+
+    /// Handle the control channel for this tick: drain queued requests plus previously deferred ones, run each
+    /// through `control::handle`, answer `Done` immediately, retry `Retry` until its three-second deadline, hold
+    /// input/job/screenshot replies until their event happens and finish job waiters. Retry timeouts and refused
+    /// screenshots are answered as `{"ok": false, "error": ...}`; the receiver is kept for the next tick.
+    fn drain_control(&mut self, ctx: &egui::Context, now: f64) {
+        let Some(rx) = self.control_rx.take() else { return };
+        let mut reqs: Vec<(ControlRequest, f64)> = std::mem::take(&mut self.deferred);
+        while let Ok(req) = rx.try_recv() {
+            reqs.push((req, now + 3.0));
+        }
+        for (req, deadline) in reqs {
+            let reply = req.reply.clone();
+            match control::handle(self, ctx, &req, now) {
+                control::Outcome::Done(v) => {
+                    let _ = reply.send(v);
+                }
+                control::Outcome::Retry(msg) => {
+                    if now < deadline {
+                        self.deferred.push((req, deadline));
+                        ctx.request_repaint();
+                    } else {
+                        let _ = reply.send(json!({"ok": false, "error": msg}));
+                    }
+                }
+                control::Outcome::AfterInput => {
+                    self.input_waiters.push(reply);
+                    // The reply waits for a real UI pass: a hidden window must run one.
+                    self.want_paint = true;
+                }
+                control::Outcome::AwaitJobs(w) => {
+                    self.job_waiters.push((w, reply));
+                    ctx.request_repaint();
+                }
+                control::Outcome::Screenshot { path, target } => {
+                    // A covered or minimized window presents no frames (macOS skips its redraws), so
+                    // a screenshot would never arrive and nothing would tick its timeout. The
+                    // hidden-window capture path (a pending screenshot forces a pass in 0.37) needs
+                    // a native platform run before this gate is removed; the web build never paints
+                    // a hidden tab.
+                    if ctx.input(|i| i.viewport().occluded == Some(true) || i.viewport().minimized == Some(true)) {
+                        let _ = reply.send(json!({"ok": false, "error": "window is covered or minimized: call ui.focus first (render.frame renders comp pixels without the window)"}));
+                        continue;
+                    }
+                    self.admit_screenshot(ctx, path, target, reply);
+                }
+            }
+        }
+        self.control_rx = Some(rx);
+        self.finish_job_waiters(ctx);
+    }
+
+    /// Reply to the control requests whose offloaded jobs ended.
+    fn finish_job_waiters(&mut self, ctx: &egui::Context) {
+        if self.job_waiters.is_empty() {
+            return;
+        }
+        self.session.poll_render();
+        self.session.poll_offload();
+        let waiters = std::mem::take(&mut self.job_waiters);
+        for (w, reply) in waiters {
+            if w.pending(self) {
+                self.job_waiters.push((w, reply));
+            } else {
+                let v = w.finish(self);
+                let _ = reply.send(v);
+            }
+        }
+        if !self.job_waiters.is_empty() {
+            ctx.request_repaint_after(std::time::Duration::from_millis(50));
+        }
+    }
+
+    // ---------------------------------------------------------------- frame
+
+    /// Apply the engine events drained this tick: open a comp, show a toast, open a URL, run a frontend command,
+    /// purge frame caches or copy an image; command and clipboard failures go to `app.ui.status`.
+    pub(super) fn handle_events(&mut self, ctx: &egui::Context) {
+        for ev in self.session.drain_events() {
+            match ev {
+                effectcraft_engine::Event::OpenComp(c) => {
+                    panels::viewers::on_open_comp(self, c);
+                    self.ui.timeline.pps = None;
+                }
+                effectcraft_engine::Event::Toast { message, .. } => self.toast = Some((message, self.now)),
+                effectcraft_engine::Event::OpenUrl(url) => ctx.open_url(egui::OpenUrl::new_tab(url)),
+                // Frames are keyed by content: an edit keeps those of comps it doesn't touch.
+                effectcraft_engine::Event::ProjectChanged { .. } => {}
+                effectcraft_engine::Event::Frontend { command, params } => {
+                    if let Err(e) = crate::menus::frontend(self, ctx, &command, params) {
+                        self.ui.status = e;
+                    }
+                }
+                effectcraft_engine::Event::PurgeCaches => self.frames.clear(),
+                effectcraft_engine::Event::CopyImage { width, height, rgba } => {
+                    if let Err(e) = copy_image(ctx, width, height, &rgba) {
+                        self.ui.status = e;
+                    }
+                }
+            }
+        }
+    }
+
+    /// The app's only non-paint entry: one tick of background work.
+    ///
+    /// This runs for every eframe logic callback, including the logic-only ticks of a hidden
+    /// window (which never reach [`Self::draw`]). It must therefore do no input handling, no
+    /// layout and no presentation: engine/job queues, autosave, playback, audio, the control
+    /// channel, screenshots and the close guard. Everything here is idempotent for a pass that
+    /// `Context::request_discard` replays.
+    pub fn tick(&mut self, ctx: &egui::Context, frame: &eframe::Frame) {
+        self.now = self.clock.now();
+        // The compositor exists before the first paint and while hidden (device-loss handling
+        // must run there too).
+        self.init_gpu(frame);
+        self.apply_gpu_failure(ctx);
+        if self.gpu_failure_applied == Some(true) {
+            self.close_after_device_loss(ctx);
+            return;
+        }
+        // Focus comes from the fresh viewport copy; a full pass's `InputState::focused` is only a
+        // fallback (a logic-only tick leaves it at the previous pass's value).
+        let focused = ctx.input(|i| i.viewport().focused.or(Some(i.focused)));
+        self.focused = focused.unwrap_or(self.focused);
+        // The interface language's fallback fonts are installed in `draw` (fonts need a pass), but
+        // commands handled here use the right catalog already.
+        let language = crate::i18n::language(self);
+        crate::i18n::set_current(language);
+        if self.styled_language != language {
+            self.want_paint = true;
+        }
+        // Frames and worker completions wake the app even while it is hidden.
+        self.frames.set_context(ctx);
+        updates_ui::tick(self, ctx);
+        if self.session.render_job.is_some() {
+            self.session.poll_render();
+            ctx.request_repaint_after(std::time::Duration::from_millis(100));
+        }
+        if self.session.track_job.is_some() {
+            self.session.poll_track();
+            ctx.request_repaint_after(std::time::Duration::from_millis(50));
+        }
+        if self.session.mask_job.is_some() {
+            self.session.poll_mask_track();
+            ctx.request_repaint_after(std::time::Duration::from_millis(50));
+        }
+        // Background tasks (Content-Aware Fill, Scene Edit Detection, imports).
+        if !self.session.tasks.is_empty() {
+            self.session.poll_jobs();
+            ctx.request_repaint_after(std::time::Duration::from_millis(100));
+        }
+        // Analyses running in a worker (the web app).
+        if !self.session.offloaded.is_empty() {
+            self.session.poll_offload();
+            ctx.request_repaint_after(std::time::Duration::from_millis(100));
+        }
+        // Warp Stabilizer: finish analyses and start queued (re-)analyses in the background.
+        if self.session.warp_job.is_some() || !self.session.warp_pending.is_empty() {
+            self.session.poll_warp(true);
+            self.session.poll_roto(true);
+            ctx.request_repaint_after(std::time::Duration::from_millis(100));
+        }
+        // Roto Brush propagation and Object Matte tracking / Freeze: finish jobs (a Freeze writes
+        // its mattes) and start queued ones in the background.
+        if self.session.roto_job.is_some() || !self.session.roto_pending.is_empty() {
+            self.session.poll_roto(true);
+            ctx.request_repaint_after(std::time::Duration::from_millis(100));
+        }
+        // 3D Camera Tracker: likewise (tracking, then solving).
+        if self.session.camera_job.is_some() || !self.session.camera_pending.is_empty() {
+            self.session.poll_camera(true);
+            ctx.request_repaint_after(std::time::Duration::from_millis(100));
+        }
+        self.run_script_tasks(ctx);
+        self.run_dialog_answers();
+        self.handle_events(ctx);
+        if let Some(rx) = self.command_inbox.take() {
+            while let Ok(id) = rx.try_recv() {
+                if let Err(e) = menus::invoke(self, ctx, &id, json!({})) {
+                    self.ui.status = e;
+                }
+            }
+            self.command_inbox = Some(rx);
+        }
+        // A close request (the window's button, Quit, `app.quit`) must be answered while hidden.
+        // An answered file dialog can change the project, so the answers above run first. The host
+        // calls `panels::unsaved::quit_on_close` last in its `logic`.
+        panels::unsaved::on_close_requested(self, ctx);
+        let title = panels::unsaved::window_title(self);
+        if title != self.window_title {
+            ctx.send_viewport_cmd(egui::ViewportCommand::Title(title.clone()));
+            self.window_title = title;
+        }
+        self.tick_autosave(ctx);
+        self.tick_workspace_autosave(ctx);
+        let now = self.now;
+        prefs_live::tick(self, ctx, now);
+        // Playback advances without a paint (its frames and the audio clock are background work).
+        // Idle prefetch keeps its old condition: it only runs once a viewer has drawn.
+        if (self.playback.playing || self.last_viewer_scale.is_some())
+            && let Some(cid) = self.session.active_comp_id()
+        {
+            let (scale, active) = (self.last_viewer_scale.unwrap_or(1.0), self.input_active);
+            self.advance_playback(ctx, scale, now, active, cid);
+        }
+        self.drain_control(ctx, now);
+        // Screenshot completion, deadlines and issuance are app-side work: the callback only
+        // stores pixels and wakes this viewport.
+        self.tick_screenshots(ctx);
+        // Time-based FPS readout over UI passes (a hidden logic-only tick is not a frame).
+        let dt = (now - self.last_time) as f32;
+        if dt > 0.0 && dt < 2.0 {
+            self.fps = self.fps * 0.9 + (1.0 / dt).min(480.0) * 0.1;
+        }
+        self.last_time = now;
+        // A hidden window paints when work needs a UI pass: queued input and waits, a settled
+        // screenshot, or playback into a child viewport.
+        let focused = self.focused;
+        let child_viewports = !self.ui.dock.layout.floating.is_empty() || prefs_live::video_preview_active(self, focused);
+        let paint = self.want_paint
+            || !self.synthetic.is_empty()
+            || !self.input_waiters.is_empty()
+            || self.pending_screenshots.iter().any(|s| s.slot.is_none())
+            || (self.playback.playing && child_viewports);
+        if paint {
+            self.request_hidden_paint(ctx);
+        }
+    }
+
+    /// Ask the host for a UI pass even when the window is minimized or occluded.
+    ///
+    /// Native eframe honours `RequestPaintWhileHidden`; the shared web backend does not carry it
+    /// yet (a browser does not paint a hidden tab), so the web build only requests a normal
+    /// repaint and hidden web screenshots/input remain unqualified.
+    fn request_hidden_paint(&mut self, ctx: &egui::Context) {
+        self.want_paint = false;
+        #[cfg(not(target_arch = "wasm32"))]
+        ctx.send_viewport_cmd(egui::ViewportCommand::RequestPaintWhileHidden);
+        ctx.request_repaint();
+    }
+
+    /// Install the theme and fonts for the current language. Fonts need a real pass: the pass
+    /// that installs them draws nothing, and the next pass draws with them (the two-pass warm-up
+    /// the app has always had). Never call this from a logic-only tick.
+    fn ui_setup(&mut self, ctx: &egui::Context) {
+        panels::viewer_text::install_hooks(ctx);
+        let language = crate::i18n::language(self);
+        crate::i18n::set_current(language);
+        if (!self.styled || self.styled_language != language) && self.synthetic_in_flight {
+            // The install needs a pass that draws nothing, but this pass has already applied a
+            // synthetic batch: defer the theme/font install by one pass instead of dropping the
+            // input (feeds are only put into a pass that can draw).
+            ctx.request_repaint();
+            return;
+        }
+        if !self.styled || self.styled_language != language {
+            theme::install(ctx, &self.tokens, language);
+            self.styled_language = language;
+            if !self.styled {
+                fit_window(ctx);
+                self.styled = true;
+            }
+            self.fonts_ready = false;
+            ctx.request_repaint();
+        } else if !self.fonts_ready {
+            // The pass after the install draws: egui has the new font definitions by now.
+            self.fonts_ready = true;
+            ctx.request_repaint();
+        }
+    }
+
+    /// One UI pass: setup, input-driven shortcuts, layout and painting. Called from
+    /// `eframe::App::ui` and by tests with the root `Ui`.
+    pub fn draw(&mut self, ui: &mut egui::Ui, frame: &eframe::Frame) {
+        panels::viewer_text::begin_ui(ui.ctx());
+        self.draw_inner(ui, frame);
+        // All exits, including fonts/device loss, observe this pass's real custom availability.
+        panels::viewer_text::finish_ime(self, ui);
+    }
+
+    /// Context creators install these hooks before the first full pass.
+    pub fn install_ime_reset_hooks(ctx: &egui::Context) {
+        panels::viewer_text::install_hooks(ctx);
+    }
+
+    /// Host wrappers call this after their last logic mutation, without replaying UI events.
+    pub fn finish_ime_logic(&self, ctx: &egui::Context) {
+        panels::viewer_text::finish_logic(self, ctx);
+    }
+
+    /// One UI pass after the IME begin hook: close on an applied GPU failure, run `ui_setup`, skip drawing until
+    /// fonts are ready, draw the frame, finish pointer wrapping, pump queued wasm frames, record input activity,
+    /// publish the completed pass's geometry and pass sequence, acknowledge applied synthetic input and answer
+    /// `AfterInput` replies only after a non-discarded pass. Requests repaints while frames are in flight.
+    fn draw_inner(&mut self, ui: &mut egui::Ui, frame: &eframe::Frame) {
+        let ctx = ui.ctx().clone();
+        if self.gpu_failure_applied == Some(true) {
+            self.close_after_device_loss(&ctx);
+            return;
+        }
+        self.ui_setup(&ctx);
+        if !self.fonts_ready {
+            // A pass that installs fonts draws nothing. No synthetic batch is in flight here (the
+            // hook feeds input only to a ready app), and events egui already applied are never
+            // fed again: that would double the pointer/key state of one click.
+            ctx.request_repaint();
+            return;
+        }
+        self.frame(ui);
+        #[cfg(not(target_arch = "wasm32"))]
+        pointer_wrap::finish_native(&ctx, frame);
+        // wasm32: no frame threads; render queued frames now, between UI frames.
+        if cfg!(target_arch = "wasm32") && self.frames.pump(std::time::Duration::from_millis(if self.playback.playing { 24 } else { 40 })) {
+            ctx.request_repaint();
+        }
+        // Input belongs to this known UI phase: record it for the next tick.
+        let active = ctx.input(|i| !i.events.is_empty() || i.pointer.any_down() || i.pointer.is_moving());
+        self.input_active = active;
+        self.last_pointer_down = ctx.input(|i| i.pointer.any_down());
+        // Geometry of a completed pass (a discarded pass is laid out again; only the final one
+        // describes the surface the next capture will see). Window position is irrelevant.
+        if !ctx.will_discard() {
+            let rect = ctx.content_rect();
+            let ppp = ctx.pixels_per_point();
+            let changed = self.draw_geom.is_none_or(|g| g.rect.size() != rect.size() || g.ppp != ppp);
+            if changed {
+                self.geometry_epoch = self.geometry_epoch.wrapping_add(1);
+            }
+            self.draw_geom = Some(DrawGeometry { rect, ppp, epoch: self.geometry_epoch });
+            self.ui_pass_seq = self.ui_pass_seq.saturating_add(1);
+        }
+        // A batch is acknowledged once a UI pass applied it, even if layout was later discarded.
+        self.mark_synthetic_applied();
+        // `AfterInput` replies wait for the final (non-discarded) pass that applied the last
+        // synthetic event: a hidden request is answered only after its forced pass, and a pass
+        // egui throws away cannot produce an early success reply.
+        if !ctx.will_discard() && self.synthetic.is_empty() {
+            for w in self.input_waiters.drain(..) {
+                let _ = w.send(json!({"ok": true, "result": null}));
+            }
+        } else if !self.input_waiters.is_empty() {
+            self.want_paint = true;
+            ctx.request_repaint();
+        }
+        if self.frames.inflight() > 0 {
+            ctx.request_repaint_after(std::time::Duration::from_millis(30));
+        }
+    }
+
+    /// The panels, menus, dialogs and overlays of one pass.
+    fn frame(&mut self, ui: &mut egui::Ui) {
+        let ctx = ui.ctx().clone();
+        // Only a viewer that draws in *this* pass records a scale: a closed viewer, the Home
+        // screen or another comp must stop idle prefetch at a stale scale.
+        self.last_viewer_scale = None;
+        self.apply_prefs(&ctx);
+        // Video Preview is a second viewport: only a real pass can update it.
+        prefs_live::frame(self, &ctx);
+        self.auto.begin_frame();
+        let tab_had_widget_focus = ctx.egui_wants_keyboard_input();
+        menus::handle_shortcuts(self, &ctx);
+        if !ctx.input(|i| i.pointer.primary_down()) {
+            self.ui.viewer.property_interacting = false;
+        }
+        let t = self.tokens;
+        let full = ui.max_rect();
+        if self.dialog.is_some() {
+            ui.disable();
+        }
+        ui.painter().rect_filled(full, 0.0, t.app_bg);
+        let mut top = full.min.y;
+        if self.ui.show_menu_bar {
+            let mb = egui::Rect::from_min_size(full.min, egui::vec2(full.width(), 24.0));
+            let mut child = ui.new_child(egui::UiBuilder::new().max_rect(mb));
+            child.painter().rect_filled(mb, 0.0, t.header_bg);
+            menus::menu_bar(self, &mut child);
+            top = mb.max.y;
+        }
+        let header_h = 40.0;
+        let header = egui::Rect::from_min_size(egui::pos2(full.min.x, top), egui::vec2(full.width(), header_h));
+        header::show(self, ui, header);
+        let body = egui::Rect::from_min_max(egui::pos2(full.min.x + 4.0, header.max.y + 2.0), egui::pos2(full.max.x - 4.0, full.max.y - 4.0));
+        self.dock_area(ui, body);
+        #[cfg(not(target_arch = "wasm32"))]
+        prefs_live::dropped_files(self, ui, full);
+        if !tab_had_widget_focus {
+            menus::handle_tab_shortcut(self, &ctx);
+        }
+        panels::precomp::mini_flowchart(self, &ctx);
+        panels::home::capture_thumbnail(self);
+        panels::dialogs::show(self, &ctx);
+        updates_ui::show(self, &ctx);
+        panels::scriptui_view::sync_panels(self);
+        panels::scriptui_view::show_windows(self, &ctx);
+        panels::learn::coach(self, &ctx);
+        let lift = panels::media_panels::import_card(self, ui, full);
+        self.draw_toast(ui, full, lift);
+    }
+
+    /// Workspace-layout auto-save: a background write that also runs while hidden, once the
+    /// pointer has lifted.
+    fn tick_workspace_autosave(&mut self, ctx: &egui::Context) {
+        if self.session.config.is_none() || !self.workspace_store.has_changes(&self.ui) || self.last_pointer_down {
+            return;
+        }
+        if self.workspace_store.due(self.now) {
+            self.save_workspace_state();
+        }
+        if self.workspace_store.has_changes(&self.ui) {
+            ctx.request_repaint_after(std::time::Duration::from_secs(1));
+        }
+    }
+
+    pub(super) fn save_workspace_state(&mut self) {
+        if let Err(error) = self.workspace_store.save(self.session.config.as_deref(), &self.ui) {
+            if self.workspace_store.error.as_ref() != Some(&error) {
+                log::warn!("{error}");
+                self.ui.status = error.clone();
+            }
+            self.workspace_store.error = Some(error);
+        }
+    }
+
+    /// The status message or the latest toast, bottom left (`lift` points higher while the
+    /// Importing card is there).
+    fn draw_toast(&mut self, ui: &mut egui::Ui, full: egui::Rect, lift: f32) {
+        let now = self.now;
+        let msg = if !self.ui.status.is_empty() {
+            Some(self.ui.status.clone())
+        } else {
+            self.toast.as_ref().filter(|(_, at)| now - at < 4.0).map(|(m, _)| m.clone())
+        };
+        if let Some(m) = msg {
+            let t = &self.tokens;
+            let galley = ui.painter().layout_no_wrap(m.clone(), Tokens::ui(12.0), t.text);
+            let r = egui::Rect::from_min_size(egui::pos2(full.min.x + 16.0, full.max.y - 44.0 - lift), galley.size() + egui::vec2(24.0, 14.0));
+            ui.painter().rect_filled(r, 6.0, t.panel_bg);
+            ui.painter().rect_stroke(r, 6.0, egui::Stroke::new(1.0, t.field_border), egui::StrokeKind::Inside);
+            ui.painter().galley(r.min + egui::vec2(12.0, 7.0), galley, t.text);
+            self.auto.add("toast", r, &m);
+            let resp = ui.interact(r, egui::Id::unique("toast"), egui::Sense::click());
+            if resp.clicked() {
+                self.ui.status.clear();
+                self.toast = None;
+            }
+            ui.ctx().request_repaint_after(std::time::Duration::from_millis(500));
+            if !self.ui.status.is_empty() {
+                let since: f64 = ui.data(|d| d.get_temp(egui::Id::unique("status-since")).unwrap_or(now));
+                ui.data_mut(|d| d.insert_temp(egui::Id::unique("status-since"), since));
+                if now - since > 5.0 {
+                    self.ui.status.clear();
+                    ui.data_mut(|d| d.remove::<f64>(egui::Id::unique("status-since")));
+                }
+            }
+        }
+    }
+}
+
+impl EffectcraftApp {
+    /// Scripts' `app.scheduleTask` tasks that are due (repeating ones keep a ScriptUI panel
+    /// fresh): errors as a toast, the last line printed in the status bar, and a repaint when
+    /// the next one is due.
+    fn run_script_tasks(&mut self, ctx: &egui::Context) {
+        if self.session.script_ui.task_hosts.is_empty() {
+            return;
+        }
+        let previous_comp = self.session.active_comp_id();
+        let Some(r) = effectcraft_engine::scriptui::ScriptUi::run_tasks(&mut self.session) else { return };
+        if self.session.active_comp_id().is_some() && self.session.active_comp_id() != previous_comp {
+            self.ui.start_screen = false;
+        }
+        if let Some(msg) = r["errors"].as_array().and_then(|e| e.first()).and_then(|e| e["message"].as_str()) {
+            self.toast = Some((format!("Scheduled script task: {msg}"), self.now));
+        } else if let Some(line) = r["output"].as_array().and_then(|o| o.last()).and_then(|l| l.as_str()) {
+            self.ui.status = line.to_string();
+        }
+        if let Some(next) = r["next"].as_u64() {
+            ctx.request_repaint_after(std::time::Duration::from_millis(next));
+        }
+    }
+
+    /// Auto-save a dirty project when the interval has passed (Settings ▸ Project ▸ Auto-Save).
+    fn tick_autosave(&mut self, ctx: &egui::Context) {
+        // Monotonic app time: a wall-clock jump must not skip or repeat an auto-save.
+        let now = self.now;
+        if let Some(Err(e)) = self.session.autosave_tick(now) {
+            self.ui.status = e.to_string();
+        }
+        if self.session.prefs.auto_save.enabled {
+            ctx.request_repaint_after(std::time::Duration::from_secs(30));
+        }
+        // File ▸ Watch Folder: look for new projects every 10 seconds.
+        if self.session.state.watch_folder.is_some() {
+            let key = egui::Id::unique("watchFolder.lastPoll");
+            let last: f64 = ctx.data(|d| d.get_temp(key)).unwrap_or(0.0);
+            if now - last >= 10.0 {
+                ctx.data_mut(|d| d.insert_temp(key, now));
+                match self.session.execute("file.watchFolder.poll", serde_json::json!({})) {
+                    Ok(r) => {
+                        if let Some(n) = r["rendered"].as_array().map(Vec::len).filter(|n| *n > 0) {
+                            self.ui.status = format!("Watch Folder: rendered {n} project(s)");
+                        }
+                    }
+                    Err(e) => self.ui.status = e.to_string(),
+                }
+            }
+            ctx.request_repaint_after(std::time::Duration::from_secs(10));
+        }
+        self.tick_footage_reload(ctx, now);
+    }
+
+    /// Settings ▸ Import ▸ Reload Footage Changed on Disk: every two seconds, and as soon as the
+    /// window comes back to the front (after saving in another app), stamp the footage files on a
+    /// worker thread and reload the ones that changed.
+    fn tick_footage_reload(&mut self, ctx: &egui::Context, now: f64) {
+        use effectcraft_engine::footage_reload;
+        if let Some(Err(e)) = footage_reload::poll_scan(&mut self.session) {
+            self.ui.status = e.to_string();
+        }
+        let (last_key, focus_key) = (egui::Id::unique("footageReload.lastScan"), egui::Id::unique("footageReload.focused"));
+        let focused = self.focused;
+        let was_focused: bool = ctx.data(|d| d.get_temp(focus_key)).unwrap_or(focused);
+        ctx.data_mut(|d| d.insert_temp(focus_key, focused));
+        if self.session.prefs.import.auto_reload_footage == "off" || self.session.project.items.is_empty() {
+            return;
+        }
+        let last: f64 = ctx.data(|d| d.get_temp(last_key)).unwrap_or(0.0);
+        if now - last >= 2.0 || (focused && !was_focused) {
+            ctx.data_mut(|d| d.insert_temp(last_key, now));
+            footage_reload::start_scan(&mut self.session);
+        }
+        if self.session.footage_scan.is_some() {
+            ctx.request_repaint_after(std::time::Duration::from_millis(100));
+        } else {
+            ctx.request_repaint_after(std::time::Duration::from_secs(2));
+        }
+    }
+}
diff --git a/crates/ui-egui/src/app/gpu.rs b/crates/ui-egui/src/app/gpu.rs
new file mode 100644
index 000000000..9febfa413
--- /dev/null
+++ b/crates/ui-egui/src/app/gpu.rs
@@ -0,0 +1,222 @@
+use super::{Arc, EffectcraftApp, RenderSource, gpu_failure, menus, panels};
+
+impl EffectcraftApp {
+    pub fn render_source(&self) -> RenderSource {
+        RenderSource {
+            project: self.session.project.clone(),
+            footage: self.session.footage.clone(),
+            expr: self.session.expr.clone(),
+            layer_cache: self.session.layer_cache.clone(),
+            gpu: self.gpu.clone(),
+            gpu_display: self.gpu_display(),
+            disk: self.session.disk_cache.clone(),
+        }
+    }
+
+    /// Keep GPU-composited viewer frames on the GPU (drawn from their texture). The browser can't
+    /// read frames back (its thread can't wait for the GPU), so there the viewer shows GPU frames
+    /// directly whenever it draws them plainly (RGB, no exposure, no region of interest); the
+    /// desktop reads them back (see [`frames::RenderSource::gpu_display`]).
+    fn gpu_display(&self) -> bool {
+        let v = &self.session.state.viewer;
+        cfg!(target_arch = "wasm32")
+            && v.channel == effectcraft_engine::viewer::Channel::Rgb
+            && v.exposure == 0.0
+            && self.session.state.region_of_interest.is_none()
+            && self.ui.viewer.extended.is_none()
+    }
+
+    /// The UI draws its panels and handles input such as dropped files. Until the fonts are
+    /// installed (the first frames) it draws nothing, and that input goes unhandled.
+    pub fn is_ready(&self) -> bool {
+        self.fonts_ready
+    }
+
+    /// Provide the executable/embedding host's device notifications. The host installs the
+    /// handlers once; this frontend never replaces handlers on a borrowed device.
+    pub fn set_gpu_failure_bridge(&mut self, bridge: gpu_failure::GpuFailureBridge) {
+        if let Some(gpu) = &self.gpu {
+            bridge.forward_to(gpu.context().device_failure_notifier());
+        }
+        self.gpu_failures = Some(bridge);
+    }
+
+    pub(super) fn apply_gpu_failure(&mut self, ctx: &egui::Context) {
+        let Some(bridge) = &self.gpu_failures else { return };
+        // Readback deadlines can retire the compositor without a host device notification.
+        if let Some(gpu) = &self.gpu
+            && let Err(reason) = gpu.context().check_health()
+        {
+            bridge.report(&reason, false);
+        }
+        let Some(failure) = bridge.failure() else { return };
+        if self.gpu_failure_applied == Some(failure.presentation_lost) {
+            return;
+        }
+        self.gpu_failure_applied = Some(failure.presentation_lost);
+        self.gpu_checked = true;
+        self.frames.retire_gpu();
+        self.session.accel = None;
+        self.session.accel_note = Some(format!("GPU preview retired: {}", failure.reason));
+        self.session.layer_cache.clear();
+        self.gpu = None;
+        if let Some(rs) = &self.wgpu {
+            let mut renderer = rs.renderer.write();
+            if let Some((id, _, _)) = &self.viewer_native {
+                renderer.free_texture(id);
+            }
+            for (_, texture) in self.passive_tex.values() {
+                if let panels::viewers::PassiveTexture::Gpu(id, _) = texture {
+                    renderer.free_texture(id);
+                }
+            }
+        }
+        self.viewer_native = None;
+        self.passive_tex.retain(|_, (_, texture)| matches!(texture, panels::viewers::PassiveTexture::Cpu(_)));
+        self.viewer_shown = self.viewer_tex.as_ref().map(|(texture, key, _)| (texture.id(), *key));
+        self.viewer_image = None;
+        // Old completion closures retain only their detached slot, not the replacement.
+        self.viewer_readback = Default::default();
+        self.wgpu = None;
+        self.ui.status = if failure.presentation_lost {
+            "Graphics device lost. The project is still open; presentation requires restarting the application.".into()
+        } else {
+            "Shared GPU preview disabled; CPU compositing remains available.".into()
+        };
+        log::warn!("GPU preview retired: {}", failure.reason);
+        ctx.request_repaint();
+    }
+
+    /// After the graphics device is lost, eframe's renderer cannot draw again: any mesh makes
+    /// egui-wgpu panic on the main thread when it cannot stage its index buffer (#591). Draw
+    /// nothing from then on, auto-save a project with unsaved changes (keeping the crash
+    /// recovery marker, so the next launch offers it) and close the window.
+    pub(super) fn close_after_device_loss(&mut self, ctx: &egui::Context) {
+        if self.device_lost_close.is_some() {
+            return;
+        }
+        let keep_recovery = self.session.is_dirty();
+        let saved = keep_recovery.then(|| match self.session.autosave_now().and_then(|path| self.session.autosave_wait().map(|()| path)) {
+            Ok(path) => {
+                log::warn!("graphics device lost: auto-saved {path}; the next launch offers to recover it");
+                Ok(path)
+            }
+            Err(e) => {
+                log::error!("graphics device lost: {e}");
+                Err(e.to_string())
+            }
+        });
+        self.device_lost_close = Some(keep_recovery);
+        log::warn!("graphics device lost: closing the window");
+        if let Some(tell) = &self.hooks.device_lost {
+            tell(saved);
+        }
+        ctx.send_viewport_cmd(egui::ViewportCommand::Close);
+    }
+
+    /// Run the commands whose non-blocking file dialogs have been answered.
+    pub(crate) fn run_dialog_answers(&mut self) {
+        while let Ok(answer) = self.dialog_answers.1.try_recv() {
+            self.file_dialogs.answered();
+            menus::dialog_answered(self, answer);
+        }
+    }
+
+    /// Set up the GPU compositor on egui-wgpu's device (once). Without an adapter that runs
+    /// compute shaders (WebGL2, software GL) everything stays on the CPU.
+    pub(crate) fn init_gpu(&mut self, frame: &eframe::Frame) {
+        if self.gpu_checked {
+            return;
+        }
+        self.gpu_checked = true;
+        if self.gpu_failures.as_ref().is_some_and(|bridge| bridge.failure().is_some()) {
+            return;
+        }
+        let Some(rs) = frame.wgpu_render_state() else { return };
+        // Help ▸ System Compatibility Report names the adapter and backend the window got.
+        let info = rs.adapter.get_info();
+        self.session.window_adapter = Some(format!(
+            "{} ({:?}, {:?}{})",
+            info.name,
+            info.backend,
+            info.device_type,
+            if info.driver.is_empty() { String::new() } else { format!(", {} {}", info.driver, info.driver_info) }
+        ));
+        // Backend validation can panic on shader compilation even when device creation
+        // succeeded. Keep the document and the egui renderer, and use CPU compositing.
+        let gpu = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| effectcraft_gpu::Gpu::new(&rs.adapter, rs.device.clone(), rs.queue.clone())));
+        match gpu {
+            Ok(Ok(g)) => {
+                if let Some(bridge) = &self.gpu_failures {
+                    bridge.forward_to(g.context().device_failure_notifier());
+                    if bridge.failure().is_some() {
+                        return;
+                    }
+                }
+                log::info!("GPU compositor: {}", effectcraft_engine::render::Accelerator::name(&g));
+                self.session.accel = Some(Arc::new(g.clone()));
+                self.gpu = Some(g);
+                self.wgpu = Some(rs.clone());
+            }
+            Ok(Err(e)) => {
+                log::info!("GPU compositor unavailable: {e}");
+                self.session.accel_note = Some(format!("GPU compositor unavailable: {e}"));
+            }
+            Err(e) => {
+                let reason = e.downcast_ref::<String>().map(String::as_str).or_else(|| e.downcast_ref::<&str>().copied()).unwrap_or("backend panicked");
+                log::warn!("GPU compositor setup failed; using CPU compositing: {reason}");
+                self.session.accel_note = Some(format!("GPU compositor setup failed: {reason}"));
+            }
+        }
+    }
+
+    /// The viewer shows a frame composited on the GPU (drawn from its wgpu texture).
+    pub fn viewer_on_gpu(&self) -> bool {
+        matches!((&self.viewer_shown, &self.viewer_native), (Some(s), Some(n)) if s.1 == n.1)
+    }
+
+    /// The GPU compositor's adapter, when the viewer has one.
+    pub fn gpu_adapter(&self) -> Option<String> {
+        self.gpu.as_ref().map(effectcraft_engine::render::Accelerator::name)
+    }
+}
+
+#[cfg(test)]
+mod gpu_failure_tests {
+    use super::*;
+    use crate::{FrameKey, ItemId, RenderOpts, Session, Tick, json};
+
+    #[test]
+    fn host_failure_preserves_document_undo_and_cpu_pixels_and_detaches_late_readbacks() {
+        let mut session = Session::default();
+        let comp = ItemId(session.execute("comp.new", json!({"name": "Recovery", "width": 4, "height": 4, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
+        session.execute("layer.newSolid", json!({"comp": comp.0, "color": "#ff0000"})).unwrap();
+        let before = session.render(comp, Tick::ZERO, RenderOpts::default());
+        let project = session.project.clone();
+        let revision = session.revision;
+        let prefs = serde_json::to_value(&session.prefs).unwrap();
+        let mut app = EffectcraftApp::new(session);
+        let ctx = egui::Context::default();
+        let bridge = gpu_failure::GpuFailureBridge::new(&ctx);
+        app.set_gpu_failure_bridge(bridge.clone());
+        let late_slot = app.viewer_readback.1.clone();
+        let key = FrameKey { revision, content: 1, comp: comp.0, frame: 0, scale: 1000, view: 0, opts: 0 };
+        app.viewer_readback.0 = Some(key);
+        bridge.report("synthetic host device failure", true);
+        app.apply_gpu_failure(&ctx);
+        assert!(Arc::ptr_eq(&project, &app.session.project));
+        assert_eq!(app.session.revision, revision);
+        assert_eq!(serde_json::to_value(&app.session.prefs).unwrap(), prefs);
+        assert!(app.gpu_checked, "failed device cannot be initialized again next frame");
+        assert!(app.session.accel.is_none());
+        assert!(app.ui.status.contains("presentation requires restarting"));
+        assert_eq!(app.session.render(comp, Tick::ZERO, RenderOpts::default()).data, before.data);
+        *late_slot.lock().unwrap() = Some((key, Arc::new(egui::ColorImage::new([1, 1], vec![egui::Color32::RED]))));
+        assert!(app.viewer_readback.0.is_none());
+        assert!(app.viewer_readback.1.lock().unwrap().is_none(), "a late completion cannot refill the replacement slot");
+        app.session.execute("edit.undo", json!({})).unwrap();
+        assert!(app.session.project.comp(comp).unwrap().layers.is_empty());
+        app.session.execute("edit.redo", json!({})).unwrap();
+        assert_eq!(app.session.render(comp, Tick::ZERO, RenderOpts::default()).data, before.data);
+    }
+}
diff --git a/crates/ui-egui/src/app/input.rs b/crates/ui-egui/src/app/input.rs
new file mode 100644
index 000000000..18a30c254
--- /dev/null
+++ b/crates/ui-egui/src/app/input.rs
@@ -0,0 +1,60 @@
+use super::*;
+
+impl EffectcraftApp {
+    /// Feed this frame's share of the queued synthetic input (control channel `ui.click`,
+    /// `ui.drag`…) into `raw_input`. Pointer events go one per frame so egui sees press → moves
+    /// → release as a real gesture.
+    ///
+    /// Only one batch is ever moved out at a time, even when the host prepares several hidden
+    /// logic-only iterations before the forced UI pass: eframe keeps the last prepared raw input
+    /// and would otherwise apply a whole drag or click as one burst. A batch is released by the
+    /// first UI pass that applies it ([`Self::mark_synthetic_applied`]). Callers must not feed a
+    /// pass that cannot draw (fonts still installing): egui applies what it receives, so putting
+    /// an applied batch back would apply its pointer/key state twice.
+    pub fn feed_synthetic(&mut self, raw_input: &mut egui::RawInput) {
+        if self.synthetic_in_flight || self.synthetic.is_empty() {
+            return;
+        }
+        // Pointer events go one per frame so egui sees press → moves → release as a real drag.
+        let pointer = |e: &egui::Event| matches!(e, egui::Event::PointerMoved(_) | egui::Event::PointerButton { .. } | egui::Event::MouseWheel { .. });
+        let n = if pointer(&self.synthetic[0]) {
+            1
+        } else {
+            self.synthetic
+                .iter()
+                .position(|e| pointer(e) || matches!(e, egui::Event::Key { pressed: false, .. }))
+                .map_or(self.synthetic.len(), |i| if pointer(&self.synthetic[i]) { i.max(1) } else { i + 1 })
+        };
+        let batch: Vec<egui::Event> = self.synthetic.drain(..n).collect();
+        raw_input.events.extend(batch.iter().cloned());
+        self.synthetic_in_flight_events.extend(batch);
+        self.synthetic_in_flight = true;
+    }
+
+    /// Clear the single-pending-batch guard: a UI pass has applied the injected batch.
+    ///
+    /// [`EffectcraftApp::draw`] calls this itself; harnesses that feed synthetic input
+    /// themselves (the headless kittest tests) call it after each pass they ran.
+    pub fn mark_synthetic_applied(&mut self) {
+        self.synthetic_in_flight_events.clear();
+        self.synthetic_in_flight = false;
+    }
+
+    /// The events of the injected batch that no UI pass has applied yet.
+    pub fn pending_synthetic_events(&self) -> &[egui::Event] {
+        &self.synthetic_in_flight_events
+    }
+
+    /// Whether a synthetic batch is waiting for its UI pass.
+    pub fn synthetic_in_flight(&self) -> bool {
+        self.synthetic_in_flight
+    }
+}
+
+impl EffectcraftApp {
+    /// Take the pending synthetic input (from `ui.click`, `ui.key`, …). Hosts that don't call
+    /// [`eframe::App::raw_input_hook`] (the headless test harness) feed these in themselves.
+    pub fn take_synthetic_input(&mut self) -> Vec<egui::Event> {
+        std::mem::take(&mut self.synthetic)
+    }
+}
diff --git a/crates/ui-egui/src/app/playback.rs b/crates/ui-egui/src/app/playback.rs
new file mode 100644
index 000000000..912a196f8
--- /dev/null
+++ b/crates/ui-egui/src/app/playback.rs
@@ -0,0 +1,186 @@
+use super::*;
+
+impl EffectcraftApp {
+    // ---------------------------------------------------------------- playback
+
+    pub fn play(&mut self, now: f64) {
+        let sc = self.session.prefs.preview.current;
+        self.play_with(now, sc);
+    }
+
+    /// Start the preview of a Preview panel shortcut (its range, play-from, rate, skip,
+    /// resolution, loop, caching, full screen and include options).
+    pub fn play_with(&mut self, now: f64, sc: effectcraft_engine::preview::PreviewShortcut) {
+        let Some(c) = self.session.active_comp_arc() else { return };
+        let preset = self.session.prefs.preview.get(sc).clone();
+        let plan = effectcraft_engine::preview::plan(&preset, &c, self.session.time());
+        let fr = c.frame_rate;
+        if plan.video {
+            self.session.set_time(fr.tick_of(plan.first));
+        }
+        let restore_max = preset.full_screen.then_some(self.ui.maximized);
+        let viewer = panels::viewers::active_panel(self);
+        if preset.full_screen && self.ui.dock.is_docked(viewer) {
+            self.ui.maximized = Some(viewer);
+        }
+        self.playback = Playback {
+            playing: true,
+            start_wall: now,
+            start_time: fr.tick_of(plan.first),
+            start_frame: plan.first,
+            shown: 0,
+            waiting: false,
+            fps: plan.fps,
+            shortcut: sc,
+            plan: Some(plan),
+            caching: plan.cache_first && plan.video,
+            res: preset.resolution.factor(preset.custom_resolution),
+            overlays: preset.include_overlays,
+            layer_controls: preset.include_layer_controls,
+            restore_max,
+            audio_frame: (!plan.video).then_some(plan.first),
+            audio_held: false,
+            shown_at: Default::default(),
+        };
+        if !self.playback.caching {
+            if plan.video {
+                self.playback.audio_held = self.audio_plays();
+            } else {
+                self.start_audio(fr.tick_of(plan.first));
+            }
+        }
+    }
+
+    /// The preview includes audio at the comp's frame rate and the comp has something audible.
+    fn audio_plays(&self) -> bool {
+        let (Some(pl), Some(cid)) = (self.playback.plan, self.session.active_comp_id()) else { return false };
+        let Some(c) = self.session.project.comp(cid) else { return false };
+        // A preview at another frame rate plays slower or faster than real time: silent.
+        pl.audio && (pl.fps - c.frame_rate.as_f64()).abs() <= 0.01 && effectcraft_engine::render::audio::comp_has_audio(&self.session.project, cid)
+    }
+
+    /// Start audio preview from comp time `t` when [`Self::audio_plays`] and an output device
+    /// opens.
+    pub(super) fn start_audio(&mut self, t: Tick) {
+        self.audio = None;
+        self.meter.clipped = [false; 2];
+        let (Some(pl), Some(cid)) = (self.playback.plan, self.session.active_comp_id()) else { return };
+        let Some(c) = self.session.project.comp_arc(cid).filter(|_| self.audio_plays()) else { return };
+        let out = audio::AudioOutput::from_prefs(&self.session.prefs);
+        let Some(dev) = self.hooks.audio_device.as_ref().and_then(|f| f(&out)) else { return };
+        let mix = self.session.prefs.audio.preview_sample_rate;
+        let fr = c.frame_rate;
+        match audio::AudioPlayback::start(dev, self.render_source(), cid, t, fr.tick_of(pl.start), fr.tick_of(pl.end + 1), pl.looping, mix) {
+            Ok(a) => self.audio = Some(a),
+            Err(e) => log::warn!("audio preview: {e}"),
+        }
+    }
+
+    /// Audio scrubbing: play the frame of `comp` at `t` (see [`audio::AudioScrub`]), opening the
+    /// output on first use. Silent comps and missing devices do nothing.
+    pub fn scrub_audio(&mut self, comp: ItemId, t: Tick, now: f64) {
+        if self.playback.playing || !effectcraft_engine::render::audio::comp_has_audio(&self.session.project, comp) {
+            return;
+        }
+        if self.scrub.is_none() {
+            let out = audio::AudioOutput::from_prefs(&self.session.prefs);
+            let Some(dev) = self.hooks.audio_device.as_ref().and_then(|f| f(&out)) else { return };
+            match audio::AudioScrub::open(dev, now) {
+                Ok(s) => self.scrub = Some(s),
+                Err(e) => {
+                    log::warn!("audio scrubbing: {e}");
+                    return;
+                }
+            }
+        }
+        let src = self.render_source();
+        let mix = self.session.prefs.audio.preview_sample_rate;
+        if let Some(s) = &mut self.scrub {
+            s.play(&src, comp, t, mix, now);
+        }
+    }
+
+    pub fn stop(&mut self) {
+        let was = std::mem::replace(&mut self.playback.playing, false);
+        self.audio = None;
+        self.playback.caching = false;
+        if !was {
+            return;
+        }
+        if let Some(m) = self.playback.restore_max.take() {
+            self.ui.maximized = m;
+        }
+        let Some(pl) = self.playback.plan else { return };
+        let move_time = self.session.prefs.preview.get(self.playback.shortcut).move_time_to_preview_time;
+        if !move_time {
+            self.session.set_time(pl.origin);
+        } else if let Some(f) = self.playback.audio_frame
+            && let Some(c) = self.session.active_comp()
+        {
+            let t = c.frame_rate.tick_of(f);
+            self.session.set_time(t);
+        }
+    }
+
+    pub fn toggle_play(&mut self, now: f64) {
+        let sc = self.session.prefs.preview.current;
+        self.toggle_play_with(now, sc);
+    }
+
+    /// A preview shortcut pressed: start its preview, or stop the running one. While Cache
+    /// Before Playback is still rendering, "If caching, play cached frames" plays what is
+    /// cached so far instead of stopping.
+    pub fn toggle_play_with(&mut self, now: f64, sc: effectcraft_engine::preview::PreviewShortcut) {
+        if !self.playback.playing {
+            self.play_with(now, sc);
+            return;
+        }
+        if self.playback.caching && self.session.prefs.preview.get(self.playback.shortcut).play_cached_frames && self.play_cached(now) {
+            return;
+        }
+        self.stop();
+    }
+
+    /// Cut the caching preview down to the frames cached from its first frame on and play them.
+    fn play_cached(&mut self, now: f64) -> bool {
+        let (Some(mut pl), Some(cid)) = (self.playback.plan, self.session.active_comp_id()) else { return false };
+        let scale = self.viewer_shown.as_ref().map(|(_, k)| k.scale as f64 / 1000.0).unwrap_or(1.0);
+        let series = self.frame_series(cid, scale);
+        let mut last = None;
+        let mut f = pl.first;
+        while f <= pl.end && self.frames.is_cached(&FrameKey { frame: f, ..series }) {
+            last = Some(f);
+            f += pl.step;
+        }
+        let Some(last) = last else { return false };
+        pl.end = last;
+        pl.start = pl.first;
+        self.playback.plan = Some(pl);
+        self.playback.caching = false;
+        self.playback.start_wall = now;
+        self.playback.start_frame = pl.first;
+        let t = self.session.active_comp().map(|c| c.frame_rate.tick_of(pl.first)).unwrap_or_default();
+        self.start_audio(t);
+        true
+    }
+
+    /// A preview plays with Video off in the Preview panel (audio only): the current time stays
+    /// put, so the viewer and Timeline say so instead of looking stuck (#1118). The frame under
+    /// the audible sample, when one is known.
+    pub fn video_preview_off(&self) -> Option<Option<i64>> {
+        let p = self.playback.plan.filter(|_| self.playback.playing)?;
+        (!p.video).then_some(self.playback.audio_frame)
+    }
+
+    /// The viewer shows grids, guides and safe margins (hidden while a preview without
+    /// Include Overlays plays).
+    pub fn overlays_visible(&self) -> bool {
+        !self.playback.playing || self.playback.overlays
+    }
+
+    /// The viewer shows layer handles and paths (View ▸ Show Layer Controls, and Include Layer
+    /// Controls while a preview plays).
+    pub fn layer_controls_visible(&self) -> bool {
+        self.ui.viewer.show_layer_controls && (!self.playback.playing || self.playback.layer_controls)
+    }
+}
diff --git a/crates/ui-egui/src/app/prefetch.rs b/crates/ui-egui/src/app/prefetch.rs
new file mode 100644
index 000000000..1fdf0aad1
--- /dev/null
+++ b/crates/ui-egui/src/app/prefetch.rs
@@ -0,0 +1,381 @@
+use super::{EffectcraftApp, FrameKey, FrameWindow, ItemId, PlaybackPass, audio, frames};
+
+/// Seconds without a project change before paused prefetch resumes (see
+/// [`EffectcraftApp::editing`]).
+const EDIT_QUIET: f64 = 0.3;
+
+impl EffectcraftApp {
+    /// RAM preview: advance at the preview's frame rate when frames are cached; otherwise hold
+    /// and keep rendering ahead (the green cache bar fills, then playback runs in real time).
+    pub(super) fn advance_playback(&mut self, ctx: &egui::Context, scale: f64, now: f64, input_active: bool, cid: ItemId) {
+        let Some(c) = self.session.project.comp_arc(cid) else { return };
+        let fr = c.frame_rate;
+        let plan = self.playback.plan.filter(|_| self.playback.playing);
+        let (wa, wb) = match plan {
+            Some(p) => (p.start, p.end),
+            None => (fr.frame_at(c.work_area.0), fr.frame_at(c.work_area.1 - c.frame_duration())),
+        };
+        let looping = plan.is_none_or(|p| p.looping);
+        let video = plan.is_none_or(|p| p.video);
+        // Prefetch ahead.
+        let cur = fr.frame_at(self.session.time());
+        let ahead = self.prefetch_ahead(ctx, now);
+        let queued = self.frames.inflight();
+        let series = self.frame_series(cid, scale);
+        // The preview's position orders prefetch and eviction (#595).
+        let playhead = plan.filter(|p| p.video).map(|p| frames::Playhead { series, cur, start: p.start, end: p.end, step: p.step, looping: p.looping });
+        self.frames.set_playhead(playhead);
+        let pass = PlaybackPass {
+            ctx,
+            comp: &c,
+            cid,
+            scale,
+            now,
+            frame_rate: fr,
+            series,
+            plan,
+            window: FrameWindow { first: wa, last: wb },
+            cur,
+            video,
+            looping,
+            ahead,
+            queued,
+        };
+        if self.cache_preview(&pass) {
+            return;
+        }
+        let step = plan.map_or(1, |p| p.step);
+        let fit_ahead = self.frames_that_fit(&c, scale) - 1;
+        self.prefetch_playback(&pass, fit_ahead);
+        self.pump_meters(ctx, now);
+        if !self.playback.playing {
+            self.cache_when_idle(ctx, &c, &series, now, input_active, (wa, wb));
+            return;
+        }
+        let fit = self.frames_that_fit(&c, scale);
+        self.start_held_audio(&pass, fit);
+        if self.advance_audio_clock(&pass, step) {
+            return;
+        }
+        self.advance_frame_clock(&pass, step);
+    }
+
+    /// While paused (scrubbing, editing) the viewer's frame comes first: prefetch only a few
+    /// frames, only once it is done, and not while edits keep coming (a layer dragged in the
+    /// viewer): those frames would be stale at the next step and would hold the CPU and GPU
+    /// the next viewer frame needs.
+    fn prefetch_ahead(&mut self, ctx: &egui::Context, now: f64) -> i64 {
+        if self.playback.playing {
+            (self.frames_parallelism() * 2).max(4) as i64
+        } else if self.frames.urgent_pending() {
+            0
+        } else if let Some(wait) = self.editing(now) {
+            ctx.request_repaint_after(std::time::Duration::from_secs_f64(wait));
+            0
+        } else {
+            // Keep workers available for a newly edited viewer frame. Running obsolete
+            // background renders cannot be preempted by the priority queue.
+            self.frames_parallelism().saturating_sub(1).min(2) as i64
+        }
+    }
+
+    /// Cache Before Playback: the range in play order, then start the clock. A range larger than
+    /// the RAM preview budget is cut to the frames that fit (caching more would evict the first
+    /// ones and never finish). Returns true when this pass handled the preview.
+    fn cache_preview(&mut self, pass: &PlaybackPass<'_>) -> bool {
+        let PlaybackPass { ctx, comp, cid, scale, now, frame_rate: fr, series, plan, ahead, mut queued, .. } = *pass;
+        if !self.playback.caching {
+            return false;
+        }
+        let Some(p) = plan else { return false };
+        let mut all = true;
+        let n = (p.end - p.start) / p.step + 1;
+        let fit = self.frames_that_fit(comp, scale);
+        if n > fit {
+            let mut cut = p;
+            (cut.start, cut.end) = (p.first, (p.first + (fit - 1) * p.step).min(p.end));
+            self.playback.plan = Some(cut);
+            self.toast = Some((format!("Preview cut to {fit} of {n} frames: no more fit in the RAM preview (Settings ▸ Memory & CPU)"), now));
+            ctx.request_repaint();
+            return true;
+        }
+        let order: Vec<i64> = (0..n).filter_map(|k| p.frame_after(p.first, k)).collect();
+        for f in order {
+            if self.frames.is_cached(&FrameKey { frame: f, ..series }) {
+                continue;
+            }
+            all = false;
+            if queued < ahead as usize {
+                self.request_frame(cid, f, scale);
+                queued += 1;
+            }
+        }
+        self.playback.waiting = !all;
+        if all {
+            self.playback.caching = false;
+            self.playback.start_wall = now;
+            self.playback.start_frame = p.first;
+            self.session.set_time(fr.tick_of(p.first));
+            self.start_audio(fr.tick_of(p.first));
+        }
+        ctx.request_repaint();
+        true
+    }
+
+    /// Never further ahead than the RAM preview holds: those frames would evict the ones the
+    /// preview shows first, or be evicted before it gets there (#595). The window starts at the
+    /// first uncached frame ahead: after a loop or a restart the frames just ahead are cached,
+    /// and a window from the playhead left the workers idle until it came near the end of the
+    /// cached run. It stays ahead × 3 frames wide: workers spread over the whole preview render
+    /// frames with different layers at once (on the GPU, an atlas each: #1812).
+    fn prefetch_playback(&self, pass: &PlaybackPass<'_>, fit_ahead: i64) {
+        let PlaybackPass { cid, scale, plan, cur, ahead, series, mut queued, video, .. } = *pass;
+        let FrameWindow { first: wa, last: wb } = pass.window;
+        let frame = |k: i64| match plan {
+            Some(p) => p.frame_after(cur, k),
+            None => {
+                let f = cur + k;
+                Some(if f > wb { wa + (f - wb - 1).rem_euclid((wb - wa + 1).max(1)) } else { f })
+            }
+        };
+        let cached = self.frames.cached_frames(&series);
+        let uncached = |f: i64| cached.binary_search(&f).is_err();
+        let first = match plan.filter(|_| self.playback.playing) {
+            Some(p) => (0..fit_ahead.min((p.end - p.start) / p.step.max(1) + 1))
+                .map_while(|k| frame(k).map(|f| (k, f)))
+                .find(|&(_, f)| uncached(f))
+                .map_or(0, |(k, _)| k),
+            None => 0,
+        };
+        for k in first..(first + ahead * 3).min(fit_ahead) {
+            if queued >= ahead as usize || !video {
+                break;
+            }
+            let Some(f) = frame(k) else { break };
+            if uncached(f) {
+                self.request_frame(cid, f, scale);
+                queued += 1;
+            }
+        }
+    }
+
+    /// Advance the audio or scrub output and feed its latest peaks to the level meter; an idle scrub is closed after
+    /// one second. With no source but an active meter, drive the meter to silence and request a repaint.
+    fn pump_meters(&mut self, ctx: &egui::Context, now: f64) {
+        if let Some(a) = &mut self.audio {
+            a.pump();
+            self.meter.update(a.feed.take_peaks(), now);
+        } else if let Some(s) = &mut self.scrub {
+            // Scrubbing: the meters follow the snippets; an idle second closes the output.
+            s.pump();
+            self.meter.update(s.feed.take_peaks(), now);
+            if now - s.last_used > 1.0 {
+                self.scrub = None;
+            }
+            ctx.request_repaint_after(std::time::Duration::from_millis(50));
+        } else if self.meter.active() {
+            self.meter.update([0.0; 2], now);
+            ctx.request_repaint();
+        }
+    }
+
+    /// Held sound starts once the frames ahead are cached (see `Playback::audio_held`): the
+    /// prefetch window when the silent preview keeps real time, else the rest of the preview.
+    fn start_held_audio(&mut self, pass: &PlaybackPass<'_>, fit: i64) {
+        let PlaybackPass { now, plan, series, cur, ahead, frame_rate: fr, .. } = *pass;
+        if !self.playback.audio_held {
+            return;
+        }
+        let Some(p) = plan else { return };
+        if (self.playback.keeps_up(now) && self.cached_ahead(&p, &series, cur, ahead.min(fit))) || self.cached_ahead(&p, &series, cur, fit) {
+            self.playback.audio_held = false;
+            self.playback.start_wall = now;
+            self.playback.start_frame = cur;
+            self.start_audio(fr.tick_of(cur));
+        }
+    }
+
+    /// Audio clock drives playback: show the frame under the audible sample. Returns true when
+    /// the audio path handled this pass (including stopping at the end).
+    fn advance_audio_clock(&mut self, pass: &PlaybackPass<'_>, step: i64) -> bool {
+        let PlaybackPass { ctx, now, series, video, frame_rate: fr, cur, .. } = *pass;
+        let FrameWindow { first: wa, last: wb } = pass.window;
+        let Some(a) = &self.audio else { return false };
+        if a.finished() {
+            if video {
+                self.session.set_time(fr.tick_of(wb));
+            } else {
+                self.playback.audio_frame = Some(wb);
+            }
+            self.stop();
+            return true;
+        }
+        let snap = |f: i64| wa + (f - wa).div_euclid(step) * step;
+        let target = snap(audio::frame_of_sample(a.clock(), a.rate, fr).clamp(wa, wb));
+        if !video {
+            self.playback.audio_frame = Some(target);
+        } else if self.frames.is_cached(&FrameKey { frame: target, ..series }) {
+            self.playback.waiting = false;
+            if target != cur {
+                self.session.set_time(fr.tick_of(target));
+                self.playback.frame_shown(now);
+            }
+        } else {
+            // Rendering can't keep up: rather than skip frames, the sound stops and every
+            // frame shows as it renders until the frames ahead are cached again.
+            self.audio = None;
+            self.playback.audio_held = true;
+            self.playback.waiting = true;
+            // The rate measured before the stall no longer says it keeps up.
+            self.playback.shown_at.clear();
+            self.playback.start_wall = now;
+            self.playback.start_frame = cur;
+        }
+        ctx.request_repaint();
+        true
+    }
+
+    /// The wall clock advances the preview when no audio device drives it, and shows the target
+    /// frame (or holds when it is not cached yet).
+    fn advance_frame_clock(&mut self, pass: &PlaybackPass<'_>, step: i64) {
+        let PlaybackPass { ctx, now, plan, video, looping, frame_rate: fr, cur, series, .. } = *pass;
+        let FrameWindow { first: wa, last: wb } = pass.window;
+        let elapsed = now - self.playback.start_wall;
+        // The plan carries the rate the preview was started with (and `play_with` copies it to
+        // `Playback::fps`). Deriving the frame from the plan keeps a logic-only tick correct even
+        // when a host/test supplies only the plan; a stale duplicate cannot hold playback open.
+        let fps = plan.map_or(self.playback.fps, |p| p.fps);
+        let n = ((elapsed * fps) / step as f64).floor() as i64;
+        let target = match plan {
+            Some(p) => p.frame_after(self.playback.start_frame, n),
+            None => {
+                let t = self.playback.start_frame + n;
+                if t <= wb {
+                    Some(t)
+                } else if looping {
+                    Some(wa + (t - wa).rem_euclid((wb - wa + 1).max(1)))
+                } else {
+                    None
+                }
+            }
+        };
+        let Some(target) = target else {
+            if video {
+                self.session.set_time(fr.tick_of(wb));
+            } else {
+                self.playback.audio_frame = Some(wb);
+            }
+            self.stop();
+            return;
+        };
+        if !video {
+            // Audio-only preview without an audio device: the clock runs, the time stays.
+            self.playback.audio_frame = Some(target);
+            ctx.request_repaint();
+            return;
+        }
+        if self.frames.is_cached(&FrameKey { frame: target, ..series }) {
+            self.playback.waiting = false;
+            if target != cur {
+                self.session.set_time(fr.tick_of(target));
+                self.playback.frame_shown(now);
+            }
+        } else {
+            // Not cached yet: hold the clock at the current frame (cache first, then play).
+            self.playback.waiting = true;
+            let next = plan.and_then(|p| p.frame_after(cur, 1)).unwrap_or(if cur + 1 > wb { wa } else { cur + 1 });
+            if self.frames.is_cached(&FrameKey { frame: next, ..series }) {
+                self.session.set_time(fr.tick_of(next));
+            }
+            self.playback.start_wall = now;
+            self.playback.start_frame = fr.frame_at(self.session.time());
+        }
+        ctx.request_repaint();
+    }
+
+    /// While the project keeps changing (an edit within [`EDIT_QUIET`] seconds), how long until
+    /// it counts as settled.
+    fn editing(&mut self, now: f64) -> Option<f64> {
+        if self.last_edit.1 != self.session.revision {
+            self.last_edit = (now, self.session.revision);
+        }
+        let left = EDIT_QUIET - (now - self.last_edit.0);
+        (left > 0.0).then_some(left)
+    }
+
+    /// Composition ▸ Preview ▸ Cache Frames When Idle: after a second without input or edits,
+    /// render the work area's frames (from the current time on, then from its start) in the
+    /// background, a few at a time, until it is cached or the RAM preview budget is full.
+    fn cache_when_idle(
+        &mut self,
+        ctx: &egui::Context,
+        comp: &effectcraft_engine::project::Comp,
+        series: &FrameKey,
+        now: f64,
+        input_active: bool,
+        (wa, wb): (i64, i64),
+    ) {
+        let active = input_active;
+        if active || self.last_activity.1 != self.session.revision {
+            self.last_activity = (now, self.session.revision);
+        }
+        if !self.ui.cache_when_idle || self.frames.urgent_pending() {
+            return;
+        }
+        let quiet = now - self.last_activity.0;
+        if quiet < 1.0 {
+            ctx.request_repaint_after(std::time::Duration::from_secs_f64(1.0 - quiet));
+            return;
+        }
+        // An empty work area has nothing to cache.
+        let n = wb - wa + 1;
+        if n < 1 {
+            return;
+        }
+        let cur = comp.frame_rate.frame_at(self.session.time()).clamp(wa, wb);
+        let fit = self.frames_that_fit(comp, series.scale as f64 / 1000.0).min(n);
+        let slots = (self.frames_parallelism() / 2).max(1);
+        let mut queued = self.frames.inflight();
+        let scale = series.scale as f64 / 1000.0;
+        let mut pending = false;
+        for k in 0..fit {
+            let f = wa + (cur - wa + k).rem_euclid(n);
+            if self.frames.is_cached(&FrameKey { frame: f, ..*series }) {
+                continue;
+            }
+            pending = true;
+            if queued >= slots {
+                break;
+            }
+            self.request_frame(ItemId(series.comp), f, scale);
+            queued += 1;
+        }
+        if pending {
+            ctx.request_repaint_after(std::time::Duration::from_millis(100));
+        }
+    }
+
+    /// How many viewer frames of `comp` at `scale` the RAM preview budget holds (90 % of it,
+    /// at least one).
+    /// The frames of `plan` from `cur` to its end, or as many as fit in the RAM preview, are
+    /// cached: sound can play from `cur` in real time.
+    fn cached_ahead(&self, plan: &effectcraft_engine::preview::PreviewPlan, series: &FrameKey, cur: i64, fit: i64) -> bool {
+        let cached = self.frames.cached_frames(series);
+        (0..fit).map_while(|k| plan.frame_after(cur, k)).take_while(|f| *f >= cur).all(|f| cached.binary_search(&f).is_ok())
+    }
+
+    fn frames_that_fit(&self, comp: &effectcraft_engine::project::Comp, scale: f64) -> i64 {
+        let side = |n: u32| (n as f64 * scale).ceil().max(1.0);
+        let frame = side(comp.width) * side(comp.height) * 4.0;
+        ((self.frames.budget() as f64 * 0.9 / frame) as i64).max(1)
+    }
+
+    fn frames_parallelism(&self) -> usize {
+        if cfg!(target_arch = "wasm32") {
+            // frame workers render one frame each; without them frames render one at a time
+            // on the UI thread (`Frames::pump`)
+            return self.frames.remote_slots().max(1);
+        }
+        self.frames.parallelism()
+    }
+}
diff --git a/crates/ui-egui/src/app/prefs.rs b/crates/ui-egui/src/app/prefs.rs
new file mode 100644
index 000000000..6fc424e01
--- /dev/null
+++ b/crates/ui-egui/src/app/prefs.rs
@@ -0,0 +1,166 @@
+use super::{EffectcraftApp, Tokens, json, theme};
+
+impl EffectcraftApp {
+    /// Apply changed settings: theme and brightness, label colours, tool tips, preview caches.
+    pub fn apply_prefs(&mut self, ctx: &egui::Context) {
+        // Sync with System re-applies when the system appearance changes (the host wakes the UI;
+        // nothing polls).
+        let system = if self.session.prefs.appearance.appearance_mode == "auto" { self.system_light(ctx) } else { None };
+        if self.applied_prefs == Some((self.session.prefs_revision, system)) {
+            return;
+        }
+        self.applied_prefs = Some((self.session.prefs_revision, system));
+        let p = &self.session.prefs;
+        self.ui.theme = theme::ThemeKind::from_name(p.appearance.resolved_theme(system)).unwrap_or_default();
+        self.tokens = Tokens::from_prefs(p, self.ui.theme);
+        theme::apply_visuals(ctx, &self.tokens);
+        ctx.set_theme(theme::theme_preference(&p.appearance.appearance_mode, self.ui.theme.is_light()));
+        let tips = p.general.show_tool_tips;
+        ctx.all_styles_mut(|s| s.interaction.tooltip_delay = if tips { 0.5 } else { f32::INFINITY });
+        // Settings ▸ Appearance ▸ UI Scale (#284). egui's own Ctrl+= / Ctrl+- / Ctrl+0 zoom stays
+        // off: Ctrl+0 is Window ▸ Project, and the scale is a setting.
+        ctx.options_mut(|o| o.zoom_with_keyboard = false);
+        ctx.set_zoom_factor(p.appearance.ui_scale as f32 / 100.0);
+        self.ui.cache_when_idle = p.previews.cache_frames_when_idle;
+        self.ui.viewer.fast_preview = p.previews.fast_previews;
+        self.frames.set_budget(p.cache_budgets(self.session.sys_memory).preview);
+    }
+
+    /// Change settings from the UI (applied next frame and saved).
+    pub fn set_pref(&mut self, key: &str, value: serde_json::Value) -> Result<(), String> {
+        self.session.prefs.set(key, value)?;
+        self.session.prefs_changed();
+        self.session.save_prefs();
+        Ok(())
+    }
+
+    /// Show theme `k`: the appearance mode becomes its family's (Dark or Light), and `k` that
+    /// family's theme.
+    pub fn set_theme(&mut self, ctx: &egui::Context, k: theme::ThemeKind) {
+        if let Err(e) = self.set_pref("appearance.theme", json!(k.name())) {
+            self.ui.status = e;
+        }
+        self.apply_prefs(ctx);
+    }
+
+    /// The system appearance: light (`Some(true)`), dark, or unknown. The host's answer (the Linux
+    /// desktop portal) wins over egui's, which Wayland compositors often leave empty.
+    pub fn system_light(&self, ctx: &egui::Context) -> Option<bool> {
+        self.hooks.system_theme.as_ref().and_then(|read| read(ctx)).or_else(|| ctx.system_theme()).map(|t| t == egui::Theme::Light)
+    }
+
+    /// The Tools bar's appearance button (`view.theme.toggle`): Sync with System, then Light, then
+    /// Dark, then Sync with System again. The light and dark theme choices are kept.
+    pub fn cycle_appearance(&mut self, ctx: &egui::Context) {
+        let next = match self.session.prefs.appearance.appearance_mode.as_str() {
+            "auto" => "light",
+            "light" => "dark",
+            _ => "auto",
+        };
+        if let Err(e) = self.set_pref("appearance.appearanceMode", json!(next)) {
+            self.ui.status = e;
+        }
+        self.apply_prefs(ctx);
+    }
+}
+
+#[cfg(test)]
+mod appearance_tests {
+    use super::*;
+    use crate::menus;
+    use crate::theme::ThemeKind;
+
+    fn app() -> EffectcraftApp {
+        EffectcraftApp::new(effectcraft_engine::Session::default())
+    }
+
+    /// The Tools bar's appearance button: Sync with System, Light, Dark, then Sync with System
+    /// again, showing the saved theme of each family without losing either choice.
+    #[test]
+    fn appearance_button_cycles_modes_without_losing_theme_choices() {
+        let ctx = egui::Context::default();
+        let mut app = app();
+        app.hooks.system_theme = Some(Box::new(|_| Some(egui::Theme::Dark)));
+        app.set_pref("appearance.darkTheme", json!("darker")).unwrap();
+        app.apply_prefs(&ctx);
+        assert_eq!(app.ui.theme, ThemeKind::Darker);
+        for (mode, shown) in [("auto", ThemeKind::Darker), ("light", ThemeKind::Light), ("dark", ThemeKind::Darker), ("auto", ThemeKind::Darker)] {
+            menus::invoke(&mut app, &ctx, "view.theme.toggle", json!({})).unwrap();
+            assert_eq!(app.session.prefs.appearance.appearance_mode, mode);
+            assert_eq!(app.ui.theme, shown, "{mode}");
+            assert_eq!(app.tokens.kind, shown);
+            assert_eq!(app.session.prefs.appearance.dark_theme, "darker");
+            assert_eq!(app.session.prefs.appearance.light_theme, "light");
+        }
+    }
+
+    /// Sync with System follows the host's answer (the Linux portal) when it changes, and falls
+    /// back to Dark when nothing reports a system appearance.
+    #[test]
+    fn auto_follows_a_stubbed_system_theme() {
+        use std::sync::{Arc, Mutex};
+        let ctx = egui::Context::default();
+        let mut app = app();
+        let system = Arc::new(Mutex::new(Some(egui::Theme::Light)));
+        let read = Arc::clone(&system);
+        app.hooks.system_theme = Some(Box::new(move |_| *read.lock().unwrap_or_else(std::sync::PoisonError::into_inner)));
+        app.set_pref("appearance.appearanceMode", json!("auto")).unwrap();
+        app.apply_prefs(&ctx);
+        assert_eq!(app.ui.theme, ThemeKind::Light);
+        *system.lock().unwrap() = Some(egui::Theme::Dark);
+        app.apply_prefs(&ctx);
+        assert_eq!(app.ui.theme, ThemeKind::Dark, "a system change applies without a settings change");
+        *system.lock().unwrap() = None;
+        app.apply_prefs(&ctx);
+        assert_eq!(app.ui.theme, ThemeKind::Dark);
+        // A fixed mode ignores the system.
+        *system.lock().unwrap() = Some(egui::Theme::Light);
+        app.set_pref("appearance.appearanceMode", json!("dark")).unwrap();
+        app.apply_prefs(&ctx);
+        assert_eq!(app.ui.theme, ThemeKind::Dark);
+    }
+
+    /// Sync with System leaves egui's theme preference at System, so egui never gives the native
+    /// window an appearance of its own (on macOS that stops system appearance changes reaching
+    /// the app, #642); egui's light and dark styles both carry the resolved theme. Fixed modes
+    /// pin the window to their family.
+    #[test]
+    fn auto_mode_leaves_the_native_window_following_the_system() {
+        let ctx = egui::Context::default();
+        let mut app = app();
+        app.hooks.system_theme = Some(Box::new(|_| Some(egui::Theme::Light)));
+        app.set_pref("appearance.appearanceMode", json!("auto")).unwrap();
+        app.apply_prefs(&ctx);
+        assert_eq!(app.ui.theme, ThemeKind::Light);
+        assert_eq!(ctx.options(|o| o.theme_preference), egui::ThemePreference::System);
+        for theme in [egui::Theme::Light, egui::Theme::Dark] {
+            assert_eq!(ctx.style_of(theme).visuals.panel_fill, app.tokens.panel_bg, "{theme:?}");
+        }
+        // egui asks the window to follow the system, never to take Light or Dark.
+        let mut out = ctx.run_ui(egui::RawInput::default(), |_| {});
+        out.textures_delta.clear();
+        let cmds = out.viewport_output.values().flat_map(|v| v.commands.iter()).collect::<Vec<_>>();
+        assert!(!cmds.iter().any(|c| matches!(c, egui::ViewportCommand::SetTheme(t) if t != &egui::SystemTheme::SystemDefault)), "{cmds:?}");
+        for (mode, pref) in [("light", egui::ThemePreference::Light), ("dark", egui::ThemePreference::Dark)] {
+            app.set_pref("appearance.appearanceMode", json!(mode)).unwrap();
+            app.apply_prefs(&ctx);
+            assert_eq!(ctx.options(|o| o.theme_preference), pref, "{mode}");
+            assert_eq!(ctx.global_style().visuals.panel_fill, app.tokens.panel_bg, "{mode}");
+        }
+    }
+
+    /// Picking a theme (`view.theme.*`, `ui.set {theme}`) fixes the mode to its family.
+    #[test]
+    fn picking_a_theme_fixes_its_mode() {
+        let ctx = egui::Context::default();
+        let mut app = app();
+        app.set_pref("appearance.appearanceMode", json!("auto")).unwrap();
+        menus::invoke(&mut app, &ctx, "view.theme.light", json!({})).unwrap();
+        assert_eq!(app.session.prefs.appearance.appearance_mode, "light");
+        assert_eq!(app.ui.theme, ThemeKind::Light);
+        menus::invoke(&mut app, &ctx, "view.theme.darker", json!({})).unwrap();
+        assert_eq!(app.session.prefs.appearance.appearance_mode, "dark");
+        assert_eq!(app.session.prefs.appearance.dark_theme, "darker");
+        assert_eq!(app.ui.theme, ThemeKind::Darker);
+    }
+}
diff --git a/crates/ui-egui/src/app/screenshot.rs b/crates/ui-egui/src/app/screenshot.rs
new file mode 100644
index 000000000..a80a76bd6
--- /dev/null
+++ b/crates/ui-egui/src/app/screenshot.rs
@@ -0,0 +1,330 @@
+use super::{DrawGeometry, EffectcraftApp, PendingShot, Sender, ShotTarget, control, json};
+
+/// How long a screenshot request waits for a frame, from admission (app clock seconds).
+pub(crate) const SCREENSHOT_TIMEOUT_S: f64 = 8.0;
+
+/// Seconds between a screenshot's admission and the earliest capture: the UI settles first.
+pub(crate) const SCREENSHOT_SETTLE_S: f64 = 0.35;
+
+/// Final (non-discarded) UI passes a screenshot waits for after admission before it is issued.
+pub(crate) const SCREENSHOT_SETTLE_PASSES: u64 = 3;
+
+/// Geometry changes a queued screenshot may retry before it reports an error.
+const SCREENSHOT_MAX_RETRIES: u32 = 4;
+
+/// Outstanding screenshot requests (queued or waiting for their pixels).
+pub(crate) const MAX_PENDING_SHOTS: usize = 4;
+
+/// One capture's pixels: 128 MiB.
+const MAX_SHOT_BYTES: usize = 128 * 1024 * 1024;
+
+/// Every pending capture's reserved pixels together: 256 MiB.
+const MAX_SHOT_TOTAL_BYTES: usize = 256 * 1024 * 1024;
+
+/// Whether a captured image's dimensions match `rect` at `ppp`.
+///
+/// The surface may be smaller than requested when the adapter-limit fit (fork E2) applies, but a
+/// different aspect ratio means the pixels came from another layout than the one issued.
+fn shot_image_matches(image: &egui::ColorImage, rect: egui::Rect, ppp: f32) -> bool {
+    let [w, h] = image.size;
+    if w == 0 || h == 0 || !ppp.is_finite() || ppp <= 0.0 {
+        return false;
+    }
+    let ew = (rect.width() as f64 * ppp as f64).max(1.0);
+    let eh = (rect.height() as f64 * ppp as f64).max(1.0);
+    let want = ew / eh;
+    let got = w as f64 / h as f64;
+    (got - want).abs() <= 0.02 * want.max(1.0)
+}
+
+impl EffectcraftApp {
+    /// The geometry of the last completed UI pass, if one ran.
+    pub fn draw_geometry(&self) -> Option<DrawGeometry> {
+        self.draw_geom
+    }
+
+    // ---------------------------------------------------------------- screenshots
+
+    /// The root surface geometry a screenshot is admitted against.
+    ///
+    /// The last completed pass's geometry is authoritative. Before any pass, only the viewport's
+    /// `inner_rect` (the client surface a capture returns) is accepted: `outer_rect` also covers
+    /// the title bar and window frame, so a capture issued against it would be cropped and
+    /// validated against a different rectangle than the callback delivers. A request that arrives
+    /// before the geometry is known is refused with an actionable error, and the pass that would
+    /// establish it is requested.
+    fn current_geometry(&self, ctx: &egui::Context) -> Option<DrawGeometry> {
+        if let Some(g) = self.draw_geom {
+            return Some(g);
+        }
+        let rect = ctx.input(|i| i.viewport().inner_rect)?;
+        (rect.width() > 0.0 && rect.height() > 0.0).then_some(DrawGeometry { rect, ppp: ctx.pixels_per_point(), epoch: self.geometry_epoch })
+    }
+
+    /// The point rectangle a request captures: its crop, clamped to the window, or all of it.
+    fn shot_target_rect(geom: &DrawGeometry, crop: Option<[f32; 4]>) -> Option<egui::Rect> {
+        let r = match crop {
+            Some([x, y, w, h]) if [x, y, w, h].iter().all(|v| v.is_finite()) => {
+                egui::Rect::from_min_size(geom.rect.min + egui::vec2(x, y), egui::vec2(w.max(0.0), h.max(0.0))).intersect(geom.rect)
+            }
+            Some(_) => return None,
+            None => geom.rect,
+        };
+        (r.width() > 0.0 && r.height() > 0.0).then_some(r)
+    }
+
+    /// The screen-point crop `target` names right now (a panel's or element's current rectangle),
+    /// or an actionable error when it is not on screen. Resolved at issuance, never stored from
+    /// admission: the UI may move while it settles.
+    fn shot_crop(&self, target: &ShotTarget, geom: &DrawGeometry) -> Result<Option<egui::Rect>, String> {
+        let crop = match target {
+            ShotTarget::Window => None,
+            ShotTarget::Rect(r) => Some(*r),
+            ShotTarget::Panel(p) => {
+                let id = format!("panel.{}", p.id());
+                let found = self.auto.find(&id).ok_or_else(|| format!("the {} panel is not on screen", p.title()))?;
+                Some(found.rect)
+            }
+            ShotTarget::Id(id) => Some(self.auto.find(id).ok_or_else(|| format!("no element `{id}` is on screen"))?.rect),
+        };
+        Self::shot_target_rect(geom, crop).map(Some).ok_or_else(|| "the screenshot area is empty or not a finite rectangle".to_string())
+    }
+
+    /// `target` as a crop relative to `geom`'s origin: what the image's own pixels are cut with.
+    fn shot_relative_crop(&self, target: &ShotTarget, geom: &DrawGeometry) -> Result<Option<[f32; 4]>, String> {
+        let Some(r) = self.shot_crop(target, geom)? else { return Ok(None) };
+        Ok(Some([r.min.x - geom.rect.min.x, r.min.y - geom.rect.min.y, r.width(), r.height()]))
+    }
+
+    /// Pixel bytes `rect` takes at `ppp`, checked (`width * height * 4`).
+    fn shot_pixel_bytes(rect: egui::Rect, ppp: f32) -> Option<usize> {
+        if !ppp.is_finite() || ppp <= 0.0 {
+            return None;
+        }
+        let w = (rect.width() as f64 * ppp as f64).ceil().max(1.0) as usize;
+        let h = (rect.height() as f64 * ppp as f64).ceil().max(1.0) as usize;
+        w.checked_mul(h)?.checked_mul(4)
+    }
+
+    /// Reserve and queue one `ui.screenshot`, or reply with an actionable error.
+    pub(crate) fn admit_screenshot(&mut self, ctx: &egui::Context, path: Option<String>, target: ShotTarget, reply: Sender<serde_json::Value>) {
+        let Some(geom) = self.current_geometry(ctx) else {
+            let _ = reply.send(
+                json!({"ok": false, "error": "the window geometry is not known yet (it is recorded by a completed UI pass; retry after the next frame)"}),
+            );
+            // Ask for the pass that records it.
+            self.want_paint = true;
+            ctx.request_repaint();
+            return;
+        };
+        if self.pending_screenshots.len() >= MAX_PENDING_SHOTS {
+            let _ = reply.send(json!({"ok": false, "error": format!("too many screenshots are pending (at most {MAX_PENDING_SHOTS})")}));
+            return;
+        }
+        if let Err(e) = self.shot_crop(&target, &geom) {
+            let _ = reply.send(json!({"ok": false, "error": e}));
+            return;
+        }
+        // The capture is always the whole surface (the crop is applied when the PNG is written),
+        // so the reservation and the per-image bound follow the surface's actual dimensions.
+        let Some(bytes) = Self::shot_pixel_bytes(geom.rect, geom.ppp) else {
+            let _ = reply.send(json!({"ok": false, "error": "the screenshot area is too large to reserve"}));
+            return;
+        };
+        if bytes > MAX_SHOT_BYTES {
+            let _ = reply
+                .send(json!({"ok": false, "error": format!("the screenshot would need about {bytes} bytes, over the {MAX_SHOT_BYTES}-byte per-image limit")}));
+            return;
+        }
+        if self.shot_bytes.checked_add(bytes).is_none_or(|n| n > MAX_SHOT_TOTAL_BYTES) {
+            let _ = reply.send(json!({"ok": false, "error": format!("the screenshot would exceed the {MAX_SHOT_TOTAL_BYTES}-byte pending-image budget")}));
+            return;
+        }
+        self.shot_bytes += bytes;
+        self.pending_screenshots.push(PendingShot {
+            path,
+            target,
+            crop: None,
+            reply,
+            deadline: self.now + SCREENSHOT_TIMEOUT_S,
+            settle_at: self.now + SCREENSHOT_SETTLE_S,
+            admitted: geom,
+            admitted_pass: self.ui_pass_seq,
+            issued: None,
+            slot: None,
+            reserved_bytes: bytes,
+            attempts: 0,
+        });
+        // A queued capture needs a settled UI pass before it can be issued.
+        self.want_paint = true;
+    }
+
+    /// Re-reserve request `i` against `geom` after a surface change; false when it no longer fits.
+    fn refresh_shot_reservation(&mut self, i: usize, geom: &DrawGeometry) -> bool {
+        let Some(bytes) = Self::shot_pixel_bytes(geom.rect, geom.ppp) else { return false };
+        if bytes > MAX_SHOT_BYTES {
+            return false;
+        }
+        let released = self.shot_bytes.saturating_sub(self.pending_screenshots[i].reserved_bytes);
+        if released.checked_add(bytes).is_none_or(|n| n > MAX_SHOT_TOTAL_BYTES) {
+            return false;
+        }
+        self.shot_bytes = released + bytes;
+        self.pending_screenshots[i].reserved_bytes = bytes;
+        true
+    }
+
+    /// Reply with an error to request `i` and release its reservation.
+    fn fail_shot(&mut self, i: usize, message: impl Into<String>) {
+        let shot = self.pending_screenshots.remove(i);
+        self.shot_bytes = self.shot_bytes.saturating_sub(shot.reserved_bytes);
+        let _ = shot.reply.send(json!({"ok": false, "error": message.into()}));
+    }
+
+    /// Collect completed captures, enforce timeouts and issue every settled request.
+    ///
+    /// Runs from [`Self::tick`] only: the callback stores pixels in its slot and wakes the
+    /// viewport, and everything that can write a file or reply happens here, on the app thread.
+    pub(super) fn tick_screenshots(&mut self, ctx: &egui::Context) {
+        let Some(geom) = self.current_geometry(ctx) else { return };
+        self.drain_completed_screenshots(geom);
+        self.timeout_screenshots();
+        self.issue_screenshots(ctx, geom);
+        // 4. Wake up for the earliest deadline even when no further pass is otherwise needed: an
+        //    issued capture whose callback never arrives (hidden window, display asleep, renderer
+        //    failure) would otherwise never reach its timeout. This is a timer, not a paint
+        //    request: the issued screenshot command already forces the frame it needs.
+        if let Some(next) = self.pending_screenshots.iter().map(|s| s.deadline).reduce(f64::min) {
+            let wait = (next - self.now).max(0.001);
+            ctx.request_repaint_after(std::time::Duration::from_secs_f64(wait));
+        }
+    }
+
+    /// 1. Drain completed slots. A completion whose surface epoch changed since issuance is
+    ///    discarded even if the geometry changed back: it was cropped with another frame's
+    ///    pixels-per-point.
+    fn drain_completed_screenshots(&mut self, geom: DrawGeometry) {
+        let mut i = 0;
+        while i < self.pending_screenshots.len() {
+            let taken = self.pending_screenshots.get(i).and_then(|s| s.slot.as_ref()).and_then(craft_ui::capture::CaptureSlot::take);
+            let Some(result) = taken else {
+                i += 1;
+                continue;
+            };
+            let issued = self.pending_screenshots[i].issued;
+            match result {
+                Ok(image) => {
+                    if issued.is_none_or(|g| g.epoch != geom.epoch) {
+                        self.pending_screenshots[i].slot = None;
+                        self.pending_screenshots[i].issued = None;
+                        if self.pending_screenshots[i].attempts >= SCREENSHOT_MAX_RETRIES {
+                            self.fail_shot(i, "the window resized while the screenshot was being taken");
+                        } else if !self.refresh_shot_reservation(i, &geom) {
+                            self.fail_shot(i, "the resized window is too large to capture within the screenshot budget");
+                        } else {
+                            let settle_at = self.now + SCREENSHOT_SETTLE_S;
+                            let passes = self.ui_pass_seq;
+                            let s = &mut self.pending_screenshots[i];
+                            s.attempts += 1;
+                            s.admitted = geom;
+                            s.admitted_pass = passes;
+                            s.settle_at = settle_at;
+                            i += 1;
+                        }
+                        continue;
+                    }
+                    let Some(issued) = issued else {
+                        i += 1;
+                        continue;
+                    };
+                    if !shot_image_matches(&image, issued.rect, issued.ppp) {
+                        self.fail_shot(i, "the screenshot's pixels do not match the window it was taken from");
+                        continue;
+                    }
+                    // The returned image can be smaller than requested (the E2 adapter-limit fit),
+                    // so the crop uses the image's own scale, never the issued ppp.
+                    let [iw, ih] = image.size;
+                    let (sx, sy) = (iw as f64 / issued.rect.width() as f64, ih as f64 / issued.rect.height() as f64);
+                    if !(sx.is_finite() && sx > 0.0 && sy.is_finite() && sy > 0.0) {
+                        self.fail_shot(i, "the screenshot's size does not describe the window it was taken from");
+                        continue;
+                    }
+                    let shot = self.pending_screenshots.remove(i);
+                    self.shot_bytes = self.shot_bytes.saturating_sub(shot.reserved_bytes);
+                    let r = control::save_screenshot(&image, shot.path.as_deref(), shot.crop, [sx, sy]);
+                    let _ = shot.reply.send(r);
+                }
+                Err(e) => {
+                    self.fail_shot(i, e.to_string());
+                }
+            }
+        }
+    }
+
+    /// 2. Timeouts: a late callback finds its slot cancelled and writes nothing.
+    fn timeout_screenshots(&mut self) {
+        let mut i = 0;
+        while i < self.pending_screenshots.len() {
+            if self.now > self.pending_screenshots[i].deadline {
+                self.fail_shot(i, "no frame was presented (window hidden or display asleep)");
+            } else {
+                i += 1;
+            }
+        }
+    }
+
+    /// 3. Issue settled requests. The command itself requests the paint; a request still
+    ///    waiting for its passes needs `want_paint` so a hidden window keeps painting.
+    fn issue_screenshots(&mut self, ctx: &egui::Context, geom: DrawGeometry) {
+        let mut i = 0;
+        while i < self.pending_screenshots.len() {
+            if self.pending_screenshots[i].slot.is_some() {
+                i += 1;
+                continue;
+            }
+            if geom.epoch != self.pending_screenshots[i].admitted.epoch {
+                if self.pending_screenshots[i].attempts >= SCREENSHOT_MAX_RETRIES {
+                    self.fail_shot(i, "the window kept resizing before the screenshot could be taken");
+                    continue;
+                }
+                if !self.refresh_shot_reservation(i, &geom) {
+                    self.fail_shot(i, "the resized window is too large to capture within the screenshot budget");
+                    continue;
+                }
+                let (now, passes) = (self.now, self.ui_pass_seq);
+                let s = &mut self.pending_screenshots[i];
+                s.attempts += 1;
+                s.admitted = geom;
+                s.admitted_pass = passes;
+                s.settle_at = now + SCREENSHOT_SETTLE_S;
+                self.want_paint = true;
+                i += 1;
+                continue;
+            }
+            let settled = self.ui_pass_seq >= self.pending_screenshots[i].admitted_pass.saturating_add(SCREENSHOT_SETTLE_PASSES)
+                && self.now >= self.pending_screenshots[i].settle_at;
+            if !settled {
+                self.want_paint = true;
+                i += 1;
+                continue;
+            }
+            // Resolve the crop now, against the settled UI: an element that moved since admission
+            // is captured where it is, and its rectangle is relative to this issued surface.
+            let target = self.pending_screenshots[i].target.clone();
+            let crop = match self.shot_relative_crop(&target, &geom) {
+                Ok(c) => c,
+                Err(e) => {
+                    self.fail_shot(i, e);
+                    continue;
+                }
+            };
+            let (slot, callback) = craft_ui::capture::CaptureSlot::new(ctx, egui::ViewportId::ROOT, MAX_SHOT_BYTES);
+            ctx.send_viewport_cmd(egui::ViewportCommand::Screenshot(callback));
+            let s = &mut self.pending_screenshots[i];
+            s.slot = Some(slot);
+            s.issued = Some(geom);
+            s.crop = crop;
+            i += 1;
+        }
+    }
+}
diff --git a/crates/ui-egui/src/app/viewer_frames.rs b/crates/ui-egui/src/app/viewer_frames.rs
new file mode 100644
index 000000000..3c8632cea
--- /dev/null
+++ b/crates/ui-egui/src/app/viewer_frames.rs
@@ -0,0 +1,166 @@
+use super::*;
+
+impl EffectcraftApp {
+    /// The size of the viewer frame's texture (CPU frames; fitted to the GPU's texture limit).
+    pub fn viewer_texture_size(&self) -> Option<[usize; 2]> {
+        self.viewer_tex.as_ref().map(|(t, _, _)| t.size())
+    }
+
+    /// The viewer's current pixels as 8-bit premultiplied RGBA, reading a GPU frame back the
+    /// first time something asks for it.
+    ///
+    /// The browser can't wait for the GPU: there the first call starts an asynchronous readback
+    /// and returns `None`; a later call (the next frame) has the pixels.
+    pub fn viewer_pixels(&mut self) -> Option<Arc<egui::ColorImage>> {
+        let to_image = |bytes: Vec<u8>, w: u32, h: u32| {
+            let px = bytes.as_chunks::<4>().0.iter().map(|c| egui::Color32::from_rgba_premultiplied(c[0], c[1], c[2], c[3])).collect();
+            Arc::new(egui::ColorImage::new([w as usize, h as usize], px))
+        };
+        if self.viewer_image.is_none()
+            && let (Some((_, key, f)), Some(g)) = (&self.viewer_native, &self.gpu)
+            && self.viewer_shown.as_ref().map(|s| s.1) == Some(*key)
+        {
+            if cfg!(target_arch = "wasm32") {
+                let ready = self.viewer_readback.1.lock().ok().and_then(|mut r| r.take_if(|r| r.0 == *key));
+                if let Some((_, img)) = ready {
+                    self.viewer_image = Some(img);
+                } else if self.viewer_readback.0 != Some(*key) {
+                    self.viewer_readback.0 = Some(*key);
+                    let (slot, k, (w, h)) = (self.viewer_readback.1.clone(), *key, (f.width, f.height));
+                    let ctx = self.frames.context();
+                    g.read_display_async(f, move |bytes| {
+                        if let (Some(b), Ok(mut s)) = (bytes, slot.lock()) {
+                            *s = Some((k, to_image(b, w, h)));
+                        }
+                        if let Some(c) = ctx {
+                            c.request_repaint();
+                        }
+                    });
+                }
+            } else if let Some(bytes) = g.read_display(f) {
+                self.viewer_image = Some(to_image(bytes, f.width, f.height));
+            }
+        }
+        self.viewer_image.clone()
+    }
+
+    /// The viewer's Resolution: the active composition's (saved with the project).
+    pub fn viewer_res(&self) -> state::Resolution {
+        self.session.active_comp().map(|c| c.resolution).unwrap_or_default()
+    }
+
+    /// The render scale used by the viewer right now.
+    pub fn viewer_scale(&self, zoom: f32, ppp: f32) -> f64 {
+        // The preview's Resolution (when not Auto) while it plays.
+        if self.playback.playing
+            && let Some(f) = self.playback.res
+        {
+            return state::Resolution::from_factor(f.into()).scale(zoom, ppp);
+        }
+        // Auto follows the zoom alike while playing and paused, so frames cached while scrubbing
+        // play back, and frames cached by a preview stay on screen when it stops.
+        let res = self.viewer_res();
+        let full = res.scale(zoom, ppp);
+        // Fast Previews ▸ Adaptive Resolution / Fast Draft: lower resolution while dragging.
+        let (_, k) = self.session.state.viewer.fast_previews.render(self.ui.viewer.interacting || self.ui.viewer.property_interacting);
+        if k < 1.0 && res.is_auto() {
+            return full.min((full * 0.5).max(self.session.prefs.adaptive_limit()));
+        }
+        full
+    }
+
+    /// The cache key of viewer frame `frame` of `comp` at `scale` (see [`Self::frame_series`]).
+    pub fn frame_key(&self, comp: ItemId, frame: i64, scale: f64) -> FrameKey {
+        FrameKey { frame, ..self.frame_series(comp, scale) }
+    }
+
+    /// The key of frame 0 of `comp`'s viewer frames at `scale` (the content, view and render
+    /// options are the same for every frame: loops compute this once).
+    pub fn frame_series(&self, comp: ItemId, scale: f64) -> FrameKey {
+        FrameKey {
+            revision: self.session.revision,
+            content: self.frames.content_of(&self.session.project, self.session.revision, comp),
+            comp: comp.0,
+            frame: 0,
+            scale: (scale * 1000.0).round() as u32,
+            view: self.view_hash(comp),
+            opts: frames::opts_hash(&self.frame_opts(comp, scale)),
+        }
+    }
+
+    /// The frame series the viewer of `comp` shows now (its scale, view and options, for the
+    /// comp's current content): what the cache bars count.
+    pub fn shown_series(&self, comp: ItemId) -> FrameKey {
+        let scale = self.viewer_shown.as_ref().filter(|(_, k)| k.comp == comp.0).map_or(1000, |(_, k)| k.scale);
+        self.frame_series(comp, scale as f64 / 1000.0)
+    }
+
+    /// Hash of the comp viewer's 3D view camera (0 for the active camera view).
+    pub fn view_hash(&self, comp: ItemId) -> u64 {
+        use std::hash::{Hash, Hasher};
+        let mut h = std::collections::hash_map::DefaultHasher::new();
+        // The region of interest changes what is rendered too.
+        let roi = self.viewer_region(comp);
+        if let Some(r) = roi {
+            r.map(f64::to_bits).hash(&mut h);
+        }
+        let Some(cam) = self.session.view_camera(comp) else { return if roi.is_some() { h.finish() | 1 } else { 0 } };
+        for row in cam.view.0 {
+            for v in row {
+                v.to_bits().hash(&mut h);
+            }
+        }
+        cam.zoom.to_bits().hash(&mut h);
+        cam.ortho.hash(&mut h);
+        h.finish() | 1
+    }
+
+    /// The comp-space region viewer frames of `comp` cover: the region of interest, else the
+    /// Extended Viewer's area (frame plus pasteboard), else `None` (the whole frame).
+    pub fn viewer_region(&self, comp: ItemId) -> Option<[f64; 4]> {
+        if self.session.active_comp_id() != Some(comp) {
+            return None;
+        }
+        self.session.state.region_of_interest.or(self.ui.viewer.extended)
+    }
+
+    /// Request a prefetch frame render (no-op if cached/in flight).
+    pub fn request_frame(&self, comp: ItemId, frame: i64, scale: f64) {
+        self.request_frame_with(comp, frame, scale, false);
+    }
+
+    /// Request the frame on screen: rendered before any queued prefetch.
+    pub fn request_frame_urgent(&self, comp: ItemId, frame: i64, scale: f64) {
+        self.request_frame_with(comp, frame, scale, true);
+    }
+
+    /// Render options of viewer frames of `comp` at `scale`.
+    pub fn frame_opts(&self, comp: ItemId, scale: f64) -> RenderOpts {
+        let (draft, _) = self.session.state.viewer.fast_previews.render(self.ui.viewer.interacting || self.ui.viewer.property_interacting);
+        let roi = self.viewer_region(comp);
+        RenderOpts {
+            scale,
+            motion_blur: true,
+            guides: true,
+            draft: self.ui.viewer.fast_preview || draft,
+            view: self.session.view_camera(comp),
+            roi,
+            backend: effectcraft_engine::render::Backend::Auto,
+            nested_switches: self.session.prefs.general.switches_affect_nested_comps,
+            draft_shadows: self.session.prefs.three_d.realtime_shadows,
+            proxy: Default::default(),
+        }
+    }
+
+    fn request_frame_with(&self, comp: ItemId, frame: i64, scale: f64, urgent: bool) {
+        let Some(c) = self.session.project.comp(comp) else { return };
+        let key = self.frame_key(comp, frame, scale);
+        let t = c.frame_rate.tick_of(frame);
+        let opts = self.frame_opts(comp, scale);
+        if urgent {
+            self.frames.request_urgent(&self.render_source(), key, comp, t, opts);
+        } else {
+            self.frames.request(&self.render_source(), key, comp, t, opts);
+        }
+    }
+}
diff --git a/crates/ui-egui/src/app/window.rs b/crates/ui-egui/src/app/window.rs
new file mode 100644
index 000000000..10a53f1d2
--- /dev/null
+++ b/crates/ui-egui/src/app/window.rs
@@ -0,0 +1,155 @@
+use super::*;
+
+impl EffectcraftApp {
+    /// Keep the saved workspaces for the next session (see [`EffectcraftApp::new`]): After
+    /// Effects' saved workspaces last until they are deleted (#320). `Err` when they weren't
+    /// written (#696): the change applies for this session and a later save retries it, but until
+    /// then a restart brings back what is on disk.
+    pub(crate) fn store_saved_workspaces(&mut self) -> Result<(), String> {
+        let Err(error) = self.workspace_store.save_now(self.session.config.as_deref(), &self.ui) else { return Ok(()) };
+        let message = format!("Workspace changes couldn't be saved and may be lost after a restart: {error}");
+        log::warn!("{message}");
+        self.ui.status = message.clone();
+        // The raw error, so the background retry doesn't report the same failure again.
+        self.workspace_store.error = Some(error);
+        Err(message)
+    }
+
+    pub fn set_workspace(&mut self, name: &str) {
+        // Learn: the Home screen's Learn tab (tutorials) in the Composition panel. Leaving it for
+        // another workspace closes the Home screen again: it stayed over every workspace until a
+        // project was created (#272).
+        if name == "Learn" {
+            self.ui.start_screen = true;
+            self.ui.home_learn = true;
+            self.ui.home_templates = false;
+        } else if self.ui.workspace == "Learn" {
+            self.ui.start_screen = false;
+            self.ui.home_learn = false;
+        }
+        self.ui.workspace = name.to_string();
+        self.ui.dock = self.ui.saved_workspaces.get(name).cloned().unwrap_or_else(|| dock::Workspace::new(dock::workspace(name)));
+        self.ui.maximized = None;
+    }
+
+    /// Built-in workspaces followed by the saved ones (Window ▸ Workspace ▸ Save as New Workspace).
+    pub fn workspace_names(&self) -> Vec<String> {
+        let mut v: Vec<String> = dock::WORKSPACES.iter().map(|s| s.to_string()).collect();
+        v.extend(self.saved_workspace_names());
+        v
+    }
+
+    /// The workspaces the user saved under a new name (built-ins whose changes were saved are
+    /// not repeated), in name order.
+    pub fn saved_workspace_names(&self) -> Vec<String> {
+        self.ui.saved_workspaces.keys().filter(|k| !dock::WORKSPACES.contains(&k.as_str())).cloned().collect()
+    }
+
+    /// The open Gradient Editor's draft (`panels::gradient_editor`): what OK would set.
+    pub fn gradient_draft(&self) -> &panels::gradient_editor::Draft {
+        &self.dialog_state.gradient
+    }
+
+    /// The open Gradient Editor's draft, to edit (tests and automation; the editor's own fields
+    /// do the same).
+    pub fn gradient_draft_mut(&mut self) -> &mut panels::gradient_editor::Draft {
+        &mut self.dialog_state.gradient
+    }
+
+    /// Show panel `p` (opening it in its usual place if it is closed), bring it to the front and
+    /// give it the focus: Window ▸ `<panel>`.
+    pub fn show_panel(&mut self, p: PanelKind) {
+        if !self.ui.dock.is_floating(p) && self.ui.maximized.is_some_and(|m| m != p) {
+            self.ui.maximized = None;
+        }
+        self.raise_panel(p);
+        self.ui.focused = p;
+    }
+
+    /// Bring panel `p` to the front of its group, opening it if it is closed, without moving the
+    /// focus (a comp opening brings up its viewer, an effect applied brings up Effect Controls).
+    /// A closed panel goes back where it was; one never laid out goes to its usual place: the
+    /// Composition panel in the centre with the Layer panel and other viewers (with none of
+    /// those left, above the Timeline), Layer and the viewers beside the Composition panel, and
+    /// so on.
+    pub fn raise_panel(&mut self, p: PanelKind) {
+        if !self.ui.dock.is_open(p) {
+            let docked = |q: &PanelKind| self.ui.dock.is_docked(*q);
+            let near = match p {
+                PanelKind::Composition => self
+                    .ui
+                    .dock
+                    .panels()
+                    .into_iter()
+                    .find(|q| matches!(q, PanelKind::Layer | PanelKind::Viewer(_) | PanelKind::Flowchart | PanelKind::Footage) && docked(q)),
+                PanelKind::Layer | PanelKind::Flowchart | PanelKind::Viewer(_) => Some(PanelKind::Composition),
+                PanelKind::RenderQueue => Some(PanelKind::Timeline),
+                PanelKind::EffectControls | PanelKind::History => Some(PanelKind::Project),
+                _ => Some(PanelKind::EffectsPresets),
+            }
+            .filter(|q| self.ui.dock.is_open(*q));
+            let mut workspace = self.ui.dock.clone();
+            let known = workspace.hidden.iter().any(|(q, _)| *q == p);
+            let opened = if p == PanelKind::Composition && near.is_none() && !known && self.ui.dock.is_docked(PanelKind::Timeline) {
+                workspace
+                    .apply(
+                        craft_ui::docking::Action::OpenAt {
+                            panel: p,
+                            anchor: PanelKind::Timeline,
+                            placement: craft_ui::docking::Placement::Split(craft_ui::docking::Zone::Top),
+                        },
+                        dock::permissions,
+                    )
+                    .map(|_| ())
+            } else if known {
+                workspace.set_visible(p, true, near, dock::permissions)
+            } else {
+                workspace.apply(craft_ui::docking::Action::Open { panel: p, anchor: near }, dock::permissions).map(|_| ())
+            };
+            match opened {
+                Ok(()) => self.ui.dock = workspace,
+                Err(e) => {
+                    self.ui.status = format!("can't open {}: {e}", p.title());
+                    return;
+                }
+            }
+        }
+        let _ = self.ui.dock.apply(craft_ui::docking::Action::Activate { panel: p }, dock::permissions);
+        if self.ui.dock.is_floating(p) {
+            self.pending_panel_raise = Some(p);
+        }
+    }
+}
+
+/// Maximize a first window that doesn't fit the screen, which fits it to the space beside the
+/// taskbar or dock. The 1680 × 1020 window on a smaller screen is only shrunk to the monitor's
+/// size, so with its title bar it ran under the taskbar and cut menus off at the bottom of the
+/// screen (#269).
+pub(super) fn fit_window(ctx: &egui::Context) {
+    let (monitor, window) = ctx.input(|i| (i.viewport().monitor_size, i.viewport().outer_rect.or(i.viewport().inner_rect)));
+    if let (Some(monitor), Some(window)) = (monitor, window)
+        && overflows_screen(window.size(), monitor)
+    {
+        ctx.send_viewport_cmd(egui::ViewportCommand::Maximized(true));
+    }
+}
+
+/// Whether a window `size` leaves no room on a `monitor` for a taskbar or dock (points).
+fn overflows_screen(size: egui::Vec2, monitor: egui::Vec2) -> bool {
+    const TASKBAR: f32 = 64.0;
+    size.x > monitor.x || size.y > monitor.y - TASKBAR
+}
+
+#[cfg(test)]
+mod fit_window_tests {
+    use super::overflows_screen;
+    use egui::vec2;
+
+    #[test]
+    fn a_window_taller_than_the_screen_beside_its_taskbar_overflows() {
+        // The default window on a 1366 × 768 laptop (shrunk to the monitor) and on 1080p.
+        assert!(overflows_screen(vec2(1366.0, 799.0), vec2(1366.0, 768.0)));
+        assert!(overflows_screen(vec2(1680.0, 1051.0), vec2(1920.0, 1080.0)));
+        assert!(!overflows_screen(vec2(1680.0, 1051.0), vec2(2560.0, 1440.0)));
+    }
+}
diff --git a/crates/ui-egui/src/clock.rs b/crates/ui-egui/src/clock.rs
new file mode 100644
index 000000000..184c8421c
--- /dev/null
+++ b/crates/ui-egui/src/clock.rs
@@ -0,0 +1,71 @@
+use super::*;
+
+/// The application's monotonic clock, in seconds.
+///
+/// Neither `ctx.input(|i| i.time)` nor `RawInput::time` is valid in a logic-only tick:
+/// `Context::run_logic` copies only the viewport information, so both are the previous full
+/// pass's values. Playback, auto-save, screenshot deadlines and the control channel measure time
+/// with this clock instead. Native and web use the same [`web_time::Instant`] source; tests
+/// inject [`AppClock::manual`] and advance it.
+#[derive(Clone, Debug)]
+pub struct AppClock {
+    origin: web_time::Instant,
+    manual: Option<f64>,
+}
+
+impl AppClock {
+    /// The host's monotonic clock.
+    pub fn real() -> Self {
+        Self { origin: web_time::Instant::now(), manual: None }
+    }
+
+    /// A clock tests advance explicitly with [`AppClock::advance`].
+    pub fn manual() -> Self {
+        Self { origin: web_time::Instant::now(), manual: Some(0.0) }
+    }
+
+    /// Seconds since the clock started (monotonic on native and in the browser).
+    pub fn now(&self) -> f64 {
+        match self.manual {
+            Some(t) => t,
+            None => self.origin.elapsed().as_secs_f64(),
+        }
+    }
+
+    /// Move a manual clock forward; a real clock ignores this.
+    pub fn advance(&mut self, seconds: f64) {
+        if let Some(t) = &mut self.manual {
+            *t = (*t + seconds.max(0.0)).max(0.0);
+        }
+    }
+
+    /// Whether the clock is test-driven.
+    pub fn is_manual(&self) -> bool {
+        self.manual.is_some()
+    }
+}
+
+impl Default for AppClock {
+    /// The real monotonic clock (`Self::real()`).
+    fn default() -> Self {
+        Self::real()
+    }
+}
+
+impl EffectcraftApp {
+    /// The app clock's value at the last tick.
+    pub fn now(&self) -> f64 {
+        self.now
+    }
+
+    /// The clock itself (tests advance a manual clock).
+    pub fn clock_mut(&mut self) -> &mut AppClock {
+        &mut self.clock
+    }
+
+    /// Use a test-driven clock from now on.
+    pub fn use_manual_clock(&mut self) {
+        self.clock = AppClock::manual();
+        self.now = 0.0;
+    }
+}
diff --git a/crates/ui-egui/src/credits.rs b/crates/ui-egui/src/credits.rs
index e69c99ce3..6704017b9 100644
--- a/crates/ui-egui/src/credits.rs
+++ b/crates/ui-egui/src/credits.rs
@@ -254,7 +254,7 @@ pub fn contributors_ui(ui: &mut egui::Ui, auto: &mut Registry) {
         }
         ui.separator();
         ui.label(tr("Sort"));
-        let combo = egui::ComboBox::from_id_salt("credits_sort").selected_text(v.key.label().0).show_ui(ui, |ui| {
+        let combo = craft_ui::ComboBox::from_id_salt("credits_sort").selected_text(v.key.label().0).show_ui(ui, |ui| {
             for k in SortKey::ALL {
                 let r = ui.selectable_label(v.key == k, k.label().0);
                 auto.add(&format!("about.credits.sort.{}", k.id()), r.rect, k.label().0);
diff --git a/crates/ui-egui/src/frames.rs b/crates/ui-egui/src/frames.rs
index ed00690ac..a7023a494 100644
--- a/crates/ui-egui/src/frames.rs
+++ b/crates/ui-egui/src/frames.rs
@@ -1467,933 +1467,4 @@ impl Queue {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    struct ProbeDisk {
-        keys: Mutex<HashSet<u128>>,
-        probes: std::sync::atomic::AtomicUsize,
-    }
-
-    impl RemoteFrames for ProbeDisk {
-        fn slots(&self) -> usize {
-            0
-        }
-
-        fn disk(&self) -> bool {
-            true
-        }
-
-        fn disk_contains(&self, key: u128) -> bool {
-            self.probes.fetch_add(1, Ordering::Relaxed);
-            self.keys.lock().unwrap().contains(&key)
-        }
-
-        fn start(&self, _: RemoteJob, _: RemoteDone) {}
-    }
-
-    fn disk_fixture(stored_frames: &[i64]) -> (Frames, RenderSource, FrameKey, RenderOpts, Arc<ProbeDisk>, u128) {
-        let mut session = effectcraft_engine::Session::default();
-        session.execute("comp.new", serde_json::json!({"width": 32, "height": 18, "duration": 1})).unwrap();
-        let comp = session.active_comp_id().unwrap();
-        let opts = RenderOpts::default();
-        let content = 1234;
-        let mut base = key(1, 0, opts_hash(&opts));
-        base.revision = 7;
-        base.comp = comp.0;
-        let disk = Arc::new(ProbeDisk { keys: Mutex::new(HashSet::new()), probes: 0.into() });
-        disk.keys.lock().unwrap().extend(stored_frames.iter().map(|frame| disk_cache::frame_key(content, *frame, base.scale, base.view ^ opts_hash(&opts))));
-        let mut frames = Frames::default();
-        frames.set_remote(Some(disk.clone()));
-        frames.content_keys.lock().unwrap().insert((base.revision, base.comp, 0), content);
-        let source = RenderSource {
-            project: session.project.clone(),
-            footage: session.footage.clone(),
-            expr: None,
-            layer_cache: Arc::default(),
-            gpu: None,
-            gpu_display: false,
-            disk: None,
-        };
-        (frames, source, base, opts, disk, content)
-    }
-
-    #[cfg(not(target_arch = "wasm32"))]
-    #[test]
-    fn disk_indicator_does_not_hash_on_ui_thread_and_coalesces_edits() {
-        use std::sync::mpsc;
-        use std::time::{Duration, Instant};
-        struct Disk(u128);
-        impl RemoteFrames for Disk {
-            fn slots(&self) -> usize {
-                1
-            }
-            fn disk(&self) -> bool {
-                true
-            }
-            fn disk_contains(&self, key: u128) -> bool {
-                self.0 == key
-            }
-            fn start(&self, _: RemoteJob, done: RemoteDone) {
-                done(Err("test has no renderer".into()));
-            }
-        }
-        let mut s = effectcraft_engine::Session::default();
-        s.execute("comp.new", serde_json::json!({"width":32,"height":18,"duration":1})).unwrap();
-        let cid = s.active_comp_id().unwrap();
-        let opts = RenderOpts::default();
-        let stored = disk_cache::frame_key(disk_cache::comp_content_key(&s.project, cid), 2, 1000, opts_hash(&opts));
-        let mut frames = Frames { pool: Some(rayon::ThreadPoolBuilder::new().num_threads(1).build().unwrap()), ..Default::default() };
-        frames.set_remote(Some(Arc::new(Disk(stored))));
-        let (entered, started) = mpsc::channel();
-        let (release, wait) = mpsc::channel();
-        frames.pool.as_ref().unwrap().spawn(move || {
-            entered.send(()).unwrap();
-            wait.recv_timeout(Duration::from_secs(5)).unwrap();
-        });
-        started.recv_timeout(Duration::from_secs(3)).unwrap();
-        let src = RenderSource {
-            project: s.project.clone(),
-            footage: s.footage.clone(),
-            expr: None,
-            layer_cache: Arc::default(),
-            gpu: None,
-            gpu_display: false,
-            disk: None,
-        };
-        let mut base = key(1, 0, 0);
-        base.comp = cid.0;
-        for revision in 1..50 {
-            base.revision = revision;
-            assert!(frames.disk_frames(&src, &base, 0..30, &opts).is_empty());
-        }
-        assert!(frames.content_keys.lock().unwrap().is_empty(), "painting computed a content hash while the worker was blocked");
-        assert_eq!(frames.content_key_jobs.lock().unwrap().pending.len(), 1);
-        release.send(()).unwrap();
-        let until = Instant::now() + Duration::from_secs(3);
-        while !frames.content_keys.lock().unwrap().contains_key(&(base.revision, base.comp, 0)) {
-            assert!(Instant::now() < until);
-            std::thread::sleep(Duration::from_millis(1));
-        }
-        assert_eq!(frames.disk_frames(&src, &base, 0..30, &opts), vec![2], "the blue indicator must return once its key is ready");
-        assert_eq!(frames.content_keys.lock().unwrap().len(), 1, "superseded revisions were hashed");
-    }
-
-    #[test]
-    fn disk_indicator_range_tracks_live_membership() {
-        let (frames, src, base, opts, disk, _) = disk_fixture(&[10, 12]);
-        assert_eq!(frames.disk_frames(&src, &base, 10..13, &opts), vec![10, 12]);
-        assert_eq!(disk.probes.load(Ordering::Relaxed), 3);
-
-        disk.keys.lock().unwrap().insert(disk_cache::frame_key(1234, 11, base.scale, base.view ^ opts_hash(&opts)));
-        assert_eq!(frames.disk_frames(&src, &base, 10..13, &opts), vec![10, 11, 12]);
-
-        insert(&frames, FrameKey { frame: 11, ..base });
-        disk.probes.store(0, Ordering::Relaxed);
-        assert_eq!(frames.disk_frames(&src, &base, 10..13, &opts), vec![10, 12]);
-        assert_eq!(disk.probes.load(Ordering::Relaxed), 2);
-
-        disk.keys.lock().unwrap().remove(&disk_cache::frame_key(1234, 12, base.scale, base.view ^ opts_hash(&opts)));
-        assert_eq!(frames.disk_frames(&src, &base, 10..13, &opts), vec![10]);
-
-        let mut revised = base;
-        revised.revision += 1;
-        frames.content_keys.lock().unwrap().insert((revised.revision, revised.comp, 0), 5678);
-        assert!(frames.disk_frames(&src, &revised, 10..13, &opts).is_empty());
-
-        let changed = FrameKey { scale: base.scale + 1, ..base };
-        assert!(frames.disk_frames(&src, &changed, 10..13, &opts).is_empty());
-        let changed = FrameKey { view: base.view + 1, ..base };
-        assert!(frames.disk_frames(&src, &changed, 10..13, &opts).is_empty());
-        assert!(frames.disk_frames(&src, &base, 10..13, &RenderOpts { draft: true, ..opts }).is_empty());
-    }
-
-    #[test]
-    fn disk_indicator_range_is_bounded() {
-        let (frames, src, base, opts, disk, _) = disk_fixture(&[0, 1, 99_999]);
-        assert_eq!(frames.disk_frames(&src, &base, -5..2, &opts), vec![0, 1]);
-        assert_eq!(disk.probes.load(Ordering::Relaxed), 2);
-        disk.probes.store(0, Ordering::Relaxed);
-        assert_eq!(frames.disk_frames(&src, &base, 99_999..i64::MAX, &opts), vec![99_999]);
-        assert_eq!(disk.probes.load(Ordering::Relaxed), 1);
-        disk.probes.store(0, Ordering::Relaxed);
-        assert!(frames.disk_frames(&src, &base, 2..2, &opts).is_empty());
-        // Written as a struct literal: `3..2` trips clippy::reversed_empty_ranges.
-        let reversed = std::ops::Range { start: 3, end: 2 };
-        assert!(frames.disk_frames(&src, &base, reversed, &opts).is_empty());
-        assert_eq!(disk.probes.load(Ordering::Relaxed), 0);
-    }
-
-    /// Frames larger than the texture limit are averaged down by a whole factor (#201: an
-    /// 11000×2200 comp at Full resolution against an 8192 limit).
-    #[test]
-    fn frames_over_the_texture_limit_are_averaged_down() {
-        assert_eq!(fitted_size([11000, 2200], 8192), [5500, 1100]);
-        assert_eq!(fitted_size([8192, 100], 8192), [8192, 100]);
-        assert_eq!(fitted_size([30000, 30000], 16384), [15000, 15000]);
-        assert_eq!(fitted_size([0, 0], 0), [0, 0]);
-        // 5×2 (three columns of white, then black) into 2 px: 3×2 blocks (the last one 2×2).
-        let w = egui::Color32::WHITE;
-        let b = egui::Color32::from_rgba_premultiplied(0, 0, 0, 255);
-        let img = egui::ColorImage::new([5, 2], vec![w, w, w, b, b, w, w, w, b, b]);
-        let out = fit_texture(img.clone(), 2);
-        assert_eq!(out.size, [2, 1]);
-        assert_eq!(out.pixels, vec![w, b]);
-        assert_eq!(fit_texture(img.clone(), 5).pixels, img.pixels);
-        let mixed = fit_texture(egui::ColorImage::new([2, 1], vec![w, b]), 1);
-        assert_eq!(mixed.pixels, vec![egui::Color32::from_rgba_premultiplied(128, 128, 128, 255)]);
-    }
-
-    #[test]
-    fn retirement_reaches_existing_workers_and_keeps_cpu_frames_and_completion_live() {
-        let frames = Frames::default();
-        let worker = frames.worker();
-        let first = key(1, 0, 0);
-        insert(&frames, first);
-        frames.retire_gpu();
-        assert!(worker.gpu_retired.load(Ordering::Acquire), "already queued workers share retirement");
-        assert!(frames.is_cached(&first), "healthy materialized CPU frames survive");
-        let next = key(1, 1, 0);
-        frames.inflight.lock().unwrap().insert(next);
-        frames.queue.lock().unwrap().running.insert(next);
-        worker.finish_key(next, false, img(), web_time::Instant::now());
-        assert!(frames.is_cached(&next), "CPU retry can still publish");
-        assert_eq!(frames.inflight(), 0);
-        assert!(frames.queue.lock().unwrap().running.is_empty());
-    }
-
-    fn key(content: u64, frame: i64, opts: u64) -> FrameKey {
-        FrameKey { revision: content, content, comp: 1, frame, scale: 1000, view: 0, opts }
-    }
-
-    fn img() -> FrameImage {
-        FrameImage::Cpu(Arc::new(egui::ColorImage::new([2, 2], vec![egui::Color32::BLACK; 4])))
-    }
-
-    fn insert(f: &Frames, k: FrameKey) {
-        f.cache.lock().unwrap().insert(k, img());
-    }
-
-    /// A frame whose render panics (a GPU out of memory used to, on every frame thread) is
-    /// released, not left "in progress" forever, so the viewer can ask for it again (#106).
-    #[test]
-    fn a_frame_whose_render_panics_is_released() {
-        use effectcraft_engine::Session;
-        use effectcraft_engine::project::{Footage, FootageKind};
-        use effectcraft_engine::render::Image;
-        use serde_json::json;
-        use std::sync::atomic::{AtomicUsize, Ordering};
-        #[derive(Default)]
-        struct Explodes(AtomicUsize);
-        impl FootageSource for Explodes {
-            fn frame(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<Image>> {
-                self.0.fetch_add(1, Ordering::SeqCst);
-                panic!("a decoder bug");
-            }
-        }
-        let mut s = Session::default();
-        let cid = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
-        let clip = Footage { kind: FootageKind::Still, width: 8, height: 8, has_video: true, ..Default::default() };
-        let item = Arc::make_mut(&mut s.project).add_item("clip.png", Default::default(), None, ItemKind::Footage(clip));
-        s.execute("layer.addItem", json!({"item": item.0})).unwrap();
-        let footage = Arc::new(Explodes::default());
-        let src = RenderSource {
-            project: s.project.clone(),
-            footage: footage.clone(),
-            expr: None,
-            layer_cache: Arc::default(),
-            gpu: None,
-            gpu_display: false,
-            disk: None,
-        };
-        let f = Frames::default();
-        let key = FrameKey { revision: s.revision, content: f.content_of(&s.project, s.revision, cid), ..key(0, 0, 0) };
-        let key = FrameKey { comp: cid.0, ..key };
-        f.request(&src, key, cid, Tick::ZERO, RenderOpts::default());
-        for _ in 0..1000 {
-            if f.inflight() == 0 {
-                break;
-            }
-            std::thread::sleep(std::time::Duration::from_millis(5));
-        }
-        assert!(footage.0.load(Ordering::SeqCst) > 0, "the render reached the footage");
-        assert_eq!(f.inflight(), 0, "released");
-        assert!(!f.is_cached(&key));
-    }
-
-    /// #647: a pool thread waiting inside a render (on a parallel loop) never starts another
-    /// frame render on top of it. Dragging a layer queues a frame every UI frame; renders used to
-    /// nest on every thread, each holding its buffers, until memory ran out.
-    #[test]
-    fn a_waiting_render_never_starts_another_on_its_thread() {
-        use effectcraft_engine::Session;
-        use effectcraft_engine::project::{Footage, FootageKind};
-        use effectcraft_engine::render::Image;
-        use effectcraft_engine::time::FrameRate;
-        use serde_json::json;
-        use std::cell::Cell;
-        use std::sync::atomic::AtomicUsize;
-        thread_local! {
-            static DEPTH: Cell<usize> = const { Cell::new(0) };
-        }
-        /// A decoder that works in parallel, as the renderer does: its thread joins the loop and
-        /// may wait for the parts other threads took.
-        #[derive(Default)]
-        struct Parallel {
-            calls: AtomicUsize,
-            deepest: AtomicUsize,
-        }
-        impl FootageSource for Parallel {
-            fn frame(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<Image>> {
-                let d = DEPTH.get() + 1;
-                DEPTH.set(d);
-                self.deepest.fetch_max(d, Ordering::SeqCst);
-                self.calls.fetch_add(1, Ordering::SeqCst);
-                (0..64).into_par_iter().for_each(|_| std::thread::sleep(std::time::Duration::from_millis(1)));
-                DEPTH.set(d - 1);
-                Some(Arc::new(Image::new(4, 4)))
-            }
-        }
-        let mut s = Session::default();
-        let cid = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 10})).unwrap()["comp"].as_u64().unwrap());
-        let clip = Footage {
-            kind: FootageKind::Video,
-            width: 4,
-            height: 4,
-            has_video: true,
-            frame_rate: FrameRate::FPS_30,
-            duration: Tick::from_seconds_f64(10.0),
-            ..Default::default()
-        };
-        let item = Arc::make_mut(&mut s.project).add_item("clip.mov", Default::default(), None, ItemKind::Footage(clip));
-        s.execute("layer.addItem", json!({"item": item.0})).unwrap();
-        let footage = Arc::new(Parallel::default());
-        let src = RenderSource {
-            project: s.project.clone(),
-            footage: footage.clone(),
-            expr: None,
-            layer_cache: Arc::default(),
-            gpu: None,
-            gpu_display: false,
-            disk: None,
-        };
-        let f = Frames::default();
-        let content = f.content_of(&s.project, s.revision, cid);
-        let frames = 60;
-        for frame in 0..frames {
-            let key = FrameKey { revision: s.revision, content, comp: cid.0, frame, scale: 1000, view: 0, opts: 0 };
-            f.request(&src, key, cid, FrameRate::FPS_30.tick_of(frame), RenderOpts::default());
-        }
-        for _ in 0..4000 {
-            if f.inflight() == 0 {
-                break;
-            }
-            std::thread::sleep(std::time::Duration::from_millis(5));
-        }
-        assert_eq!(f.inflight(), 0, "every queued frame rendered");
-        assert!(footage.calls.load(Ordering::SeqCst) >= frames as usize);
-        assert_eq!(footage.deepest.load(Ordering::SeqCst), 1, "renders nested on a waiting thread");
-    }
-
-    /// #329: scrubbing a long movie, the viewer frame of every step the pointer passed started
-    /// rendering and seeked the movie's decoder in turn; the frame under the pointer waited for
-    /// all of them. A newer viewer frame of another time calls off the one rendering, which is
-    /// not cached (its footage may be missing).
-    #[test]
-    fn a_newer_viewer_frame_calls_off_the_one_rendering() {
-        use effectcraft_engine::Session;
-        use effectcraft_engine::project::{Footage, FootageKind};
-        use effectcraft_engine::render::Image;
-        use effectcraft_engine::time::FrameRate;
-        use serde_json::json;
-        use std::cell::RefCell;
-        thread_local! {
-            static CANCEL: RefCell<Option<Arc<AtomicBool>>> = const { RefCell::new(None) };
-        }
-        /// A movie whose first frames take a long seek, which a called-off read gives up.
-        #[derive(Default)]
-        struct Seeking {
-            seeking: AtomicBool,
-            called_off: AtomicBool,
-        }
-        impl FootageSource for Seeking {
-            fn cancellable(&self, cancel: &Arc<AtomicBool>, f: &mut dyn FnMut()) {
-                let prev = CANCEL.replace(Some(cancel.clone()));
-                f();
-                CANCEL.set(prev);
-            }
-            fn frame(&self, _: ItemId, _: &Footage, t: Tick) -> Option<Arc<Image>> {
-                if t < Tick::from_seconds_f64(0.25) {
-                    self.seeking.store(true, Ordering::SeqCst);
-                    for _ in 0..1000 {
-                        if CANCEL.with_borrow(|c| c.as_ref().is_some_and(|c| c.load(Ordering::SeqCst))) {
-                            self.called_off.store(true, Ordering::SeqCst);
-                            return None;
-                        }
-                        std::thread::sleep(std::time::Duration::from_millis(5));
-                    }
-                }
-                Some(Arc::new(Image::new(4, 4)))
-            }
-        }
-        let mut s = Session::default();
-        let cid = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 10})).unwrap()["comp"].as_u64().unwrap());
-        let clip = Footage {
-            kind: FootageKind::Video,
-            width: 4,
-            height: 4,
-            has_video: true,
-            frame_rate: FrameRate::FPS_30,
-            duration: Tick::from_seconds_f64(10.0),
-            ..Default::default()
-        };
-        let item = Arc::make_mut(&mut s.project).add_item("clip.mov", Default::default(), None, ItemKind::Footage(clip));
-        s.execute("layer.addItem", json!({"item": item.0})).unwrap();
-        let footage = Arc::new(Seeking::default());
-        let src = RenderSource {
-            project: s.project.clone(),
-            footage: footage.clone(),
-            expr: None,
-            layer_cache: Arc::default(),
-            gpu: None,
-            gpu_display: false,
-            disk: None,
-        };
-        let f = Frames::default();
-        let content = f.content_of(&s.project, s.revision, cid);
-        let key = |frame| FrameKey { revision: s.revision, content, comp: cid.0, frame, scale: 1000, view: 0, opts: 0 };
-        f.request_urgent(&src, key(0), cid, Tick::ZERO, RenderOpts::default());
-        for _ in 0..1000 {
-            if footage.seeking.load(Ordering::SeqCst) {
-                break;
-            }
-            std::thread::sleep(std::time::Duration::from_millis(2));
-        }
-        assert!(footage.seeking.load(Ordering::SeqCst), "the first frame's render reached the footage");
-        f.request_urgent(&src, key(150), cid, FrameRate::FPS_30.tick_of(150), RenderOpts::default());
-        for _ in 0..1000 {
-            if f.inflight() == 0 {
-                break;
-            }
-            std::thread::sleep(std::time::Duration::from_millis(5));
-        }
-        assert!(footage.called_off.load(Ordering::SeqCst), "the superseded frame's seek ran on");
-        assert!(f.is_cached(&key(150)), "the newest frame rendered");
-        assert!(!f.is_cached(&key(0)), "a called-off frame is not cached");
-        assert_eq!(f.inflight(), 0, "released");
-    }
-
-    /// #284: scrubbing asks for a viewer frame at every step; a newer one drops the comp's viewer
-    /// frames still waiting (they would all render first), but not prefetch frames or another
-    /// comp's viewer frame.
-    #[test]
-    fn a_newer_viewer_frame_drops_the_ones_still_waiting() {
-        /// Starts nothing, so every request stays queued.
-        struct Idle;
-        impl RemoteFrames for Idle {
-            fn slots(&self) -> usize {
-                0
-            }
-            fn start(&self, _: RemoteJob, _: RemoteDone) {}
-        }
-        let mut f = Frames::default();
-        f.set_remote(Some(Arc::new(Idle)));
-        let src = RenderSource {
-            project: Arc::default(),
-            footage: Arc::new(effectcraft_engine::render::NoFootage),
-            expr: None,
-            layer_cache: Arc::default(),
-            gpu: None,
-            gpu_display: false,
-            disk: None,
-        };
-        let request = |k: FrameKey, urgent: bool| f.request_with(&src, k, ItemId(k.comp), Tick::ZERO, RenderOpts::default(), urgent);
-        let other = FrameKey { comp: 2, ..key(1, 0, 0) };
-        request(other, true);
-        request(key(1, 20, 0), false);
-        for frame in 0..10 {
-            request(key(1, frame, 0), true);
-        }
-        let mut queued: Vec<(u64, i64, bool)> = f.queue.lock().unwrap().jobs.iter().map(|j| (j.key.comp, j.key.frame, j.urgent)).collect();
-        queued.sort();
-        assert_eq!(queued, [(1, 9, true), (1, 20, false), (2, 0, false)]);
-        assert_eq!(f.inflight(), 3, "dropped frames aren't in flight: the viewer can ask again");
-    }
-
-    /// Each time the GPU runs out of memory, half as many GPU frames are kept, down to a floor.
-    #[test]
-    fn running_out_of_video_memory_halves_the_gpu_frame_budget() {
-        let f = Frames::default();
-        let mut c = f.cache.lock().unwrap();
-        assert_eq!(c.gpu_budget, GPU_BUDGET);
-        c.gpu_out_of_memory();
-        assert_eq!(c.gpu_budget, GPU_BUDGET / 2);
-        for _ in 0..20 {
-            c.gpu_out_of_memory();
-        }
-        assert_eq!(c.gpu_budget, MIN_GPU_BUDGET);
-    }
-
-    #[test]
-    fn least_recently_shown_frames_go_first() {
-        let f = Frames::default();
-        f.set_budget(3 * 16);
-        for i in 0..3 {
-            insert(&f, key(1, i, 0));
-        }
-        // Frame 0 is shown again, so frame 1 is now the oldest.
-        assert!(f.get(&key(1, 0, 0)).is_some());
-        insert(&f, key(1, 3, 0));
-        assert!(f.is_cached(&key(1, 0, 0)) && !f.is_cached(&key(1, 1, 0)));
-        assert!(f.is_cached(&key(1, 2, 0)) && f.is_cached(&key(1, 3, 0)));
-    }
-
-    fn playhead(cur: i64, looping: bool) -> Playhead {
-        Playhead { series: key(1, 0, 0), cur, start: 0, end: 99, step: 1, looping }
-    }
-
-    /// #595: a playing preview's cache is full. The frames just ahead of the playhead were
-    /// rendered before the ones just shown, so plain LRU evicted them first and the preview
-    /// played into a gap. Frames the preview no longer reaches go first, then the ones it
-    /// reaches last.
-    #[test]
-    fn a_full_cache_keeps_the_frames_just_ahead_of_the_playhead() {
-        let f = Frames::default();
-        f.set_budget(4 * 16);
-        // Prefetch rendered 11..=13, then 10 was shown (the most recently used).
-        for i in [11, 12, 13, 10] {
-            insert(&f, key(1, i, 0));
-        }
-        let cached = |f: &Frames| f.cached_frames(&key(1, 0, 0));
-        f.set_playhead(Some(playhead(10, false)));
-        // The next frame rendered is the one the preview reaches last: the frames just ahead stay.
-        insert(&f, key(1, 14, 0));
-        assert_eq!(cached(&f), [10, 11, 12, 13]);
-        // Without looping, a frame behind the playhead goes before any frame ahead of it.
-        f.set_playhead(Some(playhead(12, false)));
-        insert(&f, key(1, 14, 0));
-        assert_eq!(cached(&f), [10, 12, 13, 14]);
-        // Looping, the frame just behind is the one reached last.
-        f.set_playhead(Some(playhead(13, true)));
-        insert(&f, key(1, 0, 0));
-        assert_eq!(cached(&f), [0, 10, 13, 14]);
-        // Stopped: least recently shown first again.
-        f.set_playhead(None);
-        insert(&f, key(1, 50, 0));
-        assert!(!f.is_cached(&key(1, 13, 0)) && f.is_cached(&key(1, 50, 0)));
-    }
-
-    /// A frame source that queues jobs and never renders them: the tests check the queue.
-    struct Idle;
-    impl RemoteFrames for Idle {
-        fn slots(&self) -> usize {
-            0
-        }
-        fn start(&self, _: RemoteJob, _: RemoteDone) {}
-    }
-
-    fn idle_source() -> RenderSource {
-        RenderSource {
-            project: Arc::default(),
-            footage: Arc::new(effectcraft_engine::render::NoFootage),
-            expr: None,
-            layer_cache: Arc::default(),
-            gpu: None,
-            gpu_display: false,
-            disk: None,
-        }
-    }
-
-    /// #595: prefetch renders the frames the preview reaches first, whatever order they were
-    /// asked for in (a frame evicted and asked for again waited behind every frame further
-    /// ahead); queued frames the preview no longer reaches are dropped and not left in flight.
-    #[test]
-    fn prefetch_renders_the_frames_the_playhead_reaches_first() {
-        let mut f = Frames::default();
-        f.set_remote(Some(Arc::new(Idle)));
-        let src = idle_source();
-        for frame in [40, 30, 20, 5, 12, 11] {
-            f.request(&src, key(1, frame, 0), ItemId(1), Tick::ZERO, RenderOpts::default());
-        }
-        f.request(&src, FrameKey { comp: 2, ..key(1, 1, 0) }, ItemId(2), Tick::ZERO, RenderOpts::default());
-        f.set_playhead(Some(playhead(10, false)));
-        let mut order = vec![];
-        loop {
-            let mut q = f.queue.lock().unwrap();
-            let Some(i) = q.best() else { break };
-            let j = q.jobs.swap_remove(i);
-            order.push((j.key.comp, j.key.frame));
-        }
-        assert_eq!(order, [(1, 11), (1, 12), (1, 20), (1, 30), (1, 40), (2, 1)]);
-        assert_eq!(f.inflight(), 6, "frame 5, behind the playhead, is no longer in flight");
-    }
-
-    /// The cache is full. A zoom (or preview-resolution) change left the frames of the old
-    /// size to the plain least-recently-shown order, so the frames of the zoom the viewer is back
-    /// at went before the ones of the abandoned zoom. The other size's frames go first, then the
-    /// order is as before.
-    #[test]
-    fn a_size_change_evicts_frames_of_other_sizes_first() {
-        let mut f = Frames::default();
-        f.set_remote(Some(Arc::new(Idle)));
-        f.set_budget(4 * 16);
-        let at = |frame, scale| FrameKey { scale, ..key(1, frame, 0) };
-        // 100% (frames 0..=1) is cached, then 50% (2..=3): the 100% frames are the oldest.
-        for (frame, scale) in [(0, 1000), (1, 1000), (2, 500), (3, 500)] {
-            insert(&f, at(frame, scale));
-        }
-        // A passive viewer at 50% asks for a frame: that doesn't change which size is kept.
-        f.request(&idle_source(), at(9, 500), ItemId(1), Tick::ZERO, RenderOpts::default());
-        // Back at 100%: the viewer asks for frame 4.
-        f.request_urgent(&idle_source(), at(4, 1000), ItemId(1), Tick::ZERO, RenderOpts::default());
-        f.request(&idle_source(), at(10, 500), ItemId(1), Tick::ZERO, RenderOpts::default());
-        insert(&f, at(4, 1000));
-        assert!(
-            f.is_cached(&at(0, 1000)) && f.is_cached(&at(1, 1000)) && !f.is_cached(&at(2, 500)) && f.is_cached(&at(3, 500)),
-            "the first frame of the old size goes, not the cached ones of the current size"
-        );
-        insert(&f, at(5, 1000));
-        assert!(!f.is_cached(&at(3, 500)), "then the last frame of the old size");
-        assert_eq!(f.cached_frames(&at(0, 1000)), [0, 1, 4, 5]);
-        // No other size left: least recently shown first again.
-        insert(&f, at(6, 1000));
-        assert_eq!(f.cached_frames(&at(0, 1000)), [1, 4, 5, 6]);
-    }
-
-    #[test]
-    fn frames_are_keyed_by_content_and_series_are_kept_apart() {
-        let f = Frames::default();
-        insert(&f, key(1, 0, 0));
-        insert(&f, key(2, 0, 0));
-        insert(&f, key(2, 1, 7));
-        // Other content or render options (Draft, shadows…) are another series.
-        assert_eq!(f.cached_frames(&key(2, 0, 0)), vec![0]);
-        assert_eq!(f.cached_frames(&key(2, 0, 7)), vec![1]);
-        // A later revision with the same content finds the frame (an edit elsewhere, an undo).
-        assert!(f.is_cached(&FrameKey { revision: 99, ..key(1, 0, 0) }));
-        assert!(!f.is_cached(&key(3, 0, 0)));
-    }
-
-    #[test]
-    fn live_edits_present_the_newest_completed_revision_without_going_backwards() {
-        let f = Frames::default();
-        let shown = key(1, 0, 0);
-        let newest = key(3, 0, 0);
-        let wanted = key(5, 0, 0);
-        insert(&f, shown);
-        insert(&f, newest);
-        insert(&f, key(2, 0, 0)); // Older worker finishes after the newer one.
-        let displayed = f.get_for_viewer(&wanted, Some(&shown)).unwrap().0;
-        assert_eq!(displayed, newest);
-        assert!(f.get_for_viewer(&wanted, Some(&displayed)).is_none(), "never replay an older completion");
-        insert(&f, wanted);
-        assert_eq!(f.get_for_viewer(&wanted, Some(&displayed)).unwrap().0, wanted, "settle on the exact final edit");
-        // Undo reuses the content of an earlier revision immediately.
-        let undo = FrameKey { revision: 6, ..shown };
-        let reused = f.get_for_viewer(&undo, Some(&wanted)).unwrap().0;
-        assert_eq!(reused.content, shown.content);
-        assert_eq!(reused.revision, undo.revision);
-    }
-
-    #[test]
-    fn live_edits_do_not_substitute_other_times_views_or_render_settings() {
-        let f = Frames::default();
-        let shown = key(1, 0, 0);
-        let wanted = key(3, 0, 0);
-        let done = key(2, 0, 0);
-        for mismatch in [
-            FrameKey { comp: 9, ..done },
-            FrameKey { frame: 1, ..done },
-            FrameKey { scale: 500, ..done },
-            FrameKey { view: 1, ..done },
-            FrameKey { opts: 1, ..done },
-            FrameKey { revision: 4, ..done },
-        ] {
-            f.clear();
-            insert(&f, mismatch);
-            assert!(f.get_for_viewer(&wanted, Some(&shown)).is_none(), "wrong candidate: {mismatch:?}");
-        }
-        f.clear();
-        insert(&f, done);
-        assert!(f.get_for_viewer(&wanted, None).is_none(), "no stale content on opening a viewer");
-        assert!(f.get_for_viewer(&wanted, Some(&FrameKey { comp: 9, ..shown })).is_none());
-        assert!(f.get_for_viewer(&wanted, Some(&FrameKey { frame: 1, ..shown })).is_none());
-        assert!(f.get_for_viewer(&wanted, Some(&FrameKey { view: 1, ..shown })).is_none());
-    }
-
-    #[test]
-    fn an_edit_keeps_the_frames_of_comps_it_does_not_touch() {
-        use effectcraft_engine::Session;
-        use serde_json::json;
-        let mut s = Session::default();
-        let a = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
-        let b = ItemId(s.execute("comp.new", json!({"name": "B", "width": 8, "height": 8, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
-        let f = Frames::default();
-        let at = |s: &Session, c: ItemId| f.content_of(&s.project, s.revision, c);
-        let (a0, b0) = (at(&s, a), at(&s, b));
-        // Edit B: A's content (and frames) stay, B's change.
-        s.execute("layer.newSolid", json!({"comp": b.0, "color": "#ff0000"})).unwrap();
-        assert_eq!(at(&s, a), a0);
-        assert_ne!(at(&s, b), b0);
-        // Undo: B is back to the content its old frames were rendered for.
-        s.execute("edit.undo", json!({})).unwrap();
-        assert_eq!(at(&s, b), b0);
-    }
-
-    #[test]
-    fn a_long_drag_keeps_a_bounded_number_of_states() {
-        use effectcraft_engine::Session;
-        use serde_json::json;
-        let mut s = Session::default();
-        let a = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
-        let f = Frames::default();
-        let mut last = None;
-        for i in 0..200 {
-            s.execute("comp.settings", json!({"width": 8 + i, "merge": "drag"})).unwrap();
-            let k = FrameKey { content: f.content_of(&s.project, s.revision, a), ..key(0, 0, 0) };
-            insert(&f, k);
-            last = Some(k);
-        }
-        // The snapshots and the frames kept stay bounded (a dropped identity's frames go with it,
-        // so a later state that reuses its addresses can't be shown an old frame).
-        assert!(f.keepers.lock().unwrap().1.len() <= MAX_KEEPERS);
-        assert!(f.cache.lock().unwrap().map.len() <= MAX_KEEPERS);
-        assert!(f.is_cached(&last.unwrap()), "the current state's frame stays");
-    }
-
-    #[test]
-    fn an_identity_keeps_its_comps_so_an_edit_in_place_still_changes_it() {
-        use effectcraft_engine::Session;
-        use serde_json::json;
-        let mut s = Session::default();
-        let a = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
-        // A project nothing else holds (no undo history): make_mut would edit the comp in place,
-        // at the same address, if the identity hadn't kept a snapshot holding it.
-        let mut p = Arc::new((*s.project).clone());
-        drop(s);
-        let f = Frames::default();
-        let before = f.content_of(&p, 1, a);
-        let comp = Arc::make_mut(&mut p).comp_mut(a).unwrap();
-        comp.width = 16;
-        assert_ne!(f.content_of(&p, 2, a), before);
-    }
-
-    /// Audio, Lock and Shy (and Hide Shy Layers) don't change pixels: toggling them, in the comp
-    /// or a comp it nests, keeps its frames, also when toggled back (#103).
-    #[test]
-    fn audio_lock_and_shy_switches_keep_the_frames() {
-        use effectcraft_engine::Session;
-        use serde_json::json;
-        let mut s = Session::default();
-        let id = |v: serde_json::Value, k: &str| v[k].as_u64().unwrap();
-        let inner = ItemId(id(s.execute("comp.new", json!({"name": "Inner", "width": 8, "height": 8, "duration": 1})).unwrap(), "comp"));
-        let solid = id(s.execute("layer.newSolid", json!({"comp": inner.0, "color": "#ff0000"})).unwrap(), "layer");
-        let outer = ItemId(id(s.execute("comp.new", json!({"name": "Outer", "width": 8, "height": 8, "duration": 1})).unwrap(), "comp"));
-        let nested = id(s.execute("layer.addItem", json!({"comp": outer.0, "item": inner.0})).unwrap(), "layer");
-        let f = Frames::default();
-        let at = |s: &Session| f.content_of(&s.project, s.revision, outer);
-        let o0 = at(&s);
-        let switch = |s: &mut Session, comp: ItemId, layer: u64, sw: &str, v: bool| {
-            s.execute("layer.setSwitch", json!({"comp": comp.0, "layers": [layer], "switch": sw, "value": v})).unwrap();
-        };
-        for (comp, layer, sw) in [(outer, nested, "audio"), (outer, nested, "lock"), (outer, nested, "shy"), (inner, solid, "audio"), (inner, solid, "shy")] {
-            // Audio off; Lock and Shy on.
-            switch(&mut s, comp, layer, sw, sw != "audio");
-            assert_eq!(at(&s), o0, "{sw} on in {comp:?}");
-        }
-        s.execute("comp.setSwitch", json!({"comp": outer.0, "switch": "hideShy", "value": true})).unwrap();
-        assert_eq!(at(&s), o0, "Hide Shy Layers");
-        switch(&mut s, outer, nested, "audio", true);
-        switch(&mut s, outer, nested, "lock", false);
-        assert_eq!(at(&s), o0, "toggled back");
-        // Switches that change pixels still do.
-        switch(&mut s, inner, solid, "video", false);
-        let o1 = at(&s);
-        assert_ne!(o1, o0, "Video");
-        switch(&mut s, outer, nested, "audio", false);
-        assert_eq!(at(&s), o1, "a mute after a real edit keeps that edit's frames");
-        switch(&mut s, inner, solid, "video", true);
-        assert_ne!(at(&s), o1);
-    }
-
-    /// A cut or trim recaches only the frames of the layers it touched (#1641), and none are
-    /// kept when the change reaches other layers (here a child of the trimmed layer).
-    #[test]
-    fn an_edit_keeps_the_frames_outside_the_layers_it_changed() {
-        use effectcraft_engine::Session;
-        use serde_json::json;
-        let mut s = Session::default();
-        let id = |v: serde_json::Value, k: &str| v[k].as_u64().unwrap();
-        let comp = ItemId(id(s.execute("comp.new", json!({"name": "Edit", "width": 8, "height": 8, "duration": 10})).unwrap(), "comp"));
-        let a = id(s.execute("layer.newSolid", json!({"comp": comp.0, "color": "#ff0000"})).unwrap(), "layer");
-        let b = id(s.execute("layer.newSolid", json!({"comp": comp.0, "color": "#00ff00"})).unwrap(), "layer");
-        s.execute("layer.timing", json!({"layers": [a], "in": 0, "out": 4})).unwrap();
-        s.execute("layer.timing", json!({"layers": [b], "in": 4, "out": 10})).unwrap();
-        let (fr, out) = s.project.comp(comp).map(|c| (c.frame_rate, c.layers.iter().find(|l| l.id.0 == a).unwrap().out_point)).unwrap();
-        let frames: Vec<i64> = (0..fr.frame_at(Tick::from_seconds_f64(10.0))).collect();
-        let f = Frames::default();
-        let cache_all = |s: &Session| {
-            let c = f.content_of(&s.project, s.revision, comp);
-            frames.iter().for_each(|&n| insert(&f, key(c, n, 0)));
-            c
-        };
-        let cached = |c: u64| frames.iter().filter(|&&n| f.is_cached(&key(c, n, 0))).copied().collect::<Vec<_>>();
-        let before = cache_all(&s);
-        s.execute("time.set", json!({"time": 2.0})).unwrap();
-        s.execute("edit.splitLayer", json!({"layers": [a]})).unwrap();
-        let after = f.content_of(&s.project, s.revision, comp);
-        assert_ne!(after, before);
-        let kept: Vec<i64> = (fr.frame_at(out) + 2..frames.len() as i64).collect();
-        assert_eq!(cached(after), kept, "the cut layer's frames (and one either side) render again; the rest stay");
-
-        s.execute("layer.setParent", json!({"layers": [b], "parent": a})).unwrap();
-        let parented = cache_all(&s);
-        s.execute("layer.timing", json!({"layers": [a], "out": 1})).unwrap();
-        assert_eq!(cached(f.content_of(&s.project, s.revision, comp)), Vec::<i64>::new(), "the trimmed layer's child moves everywhere");
-        assert_eq!(cached(parented).len(), frames.len(), "the earlier frames stay for undo");
-    }
-
-    /// Every frame an edit keeps renders as a fresh render of the edited project does: Solo
-    /// hides the other layers at every frame, and a camera reaches the frames whose shutter
-    /// samples it (#1641 review).
-    #[test]
-    fn the_frames_an_edit_keeps_match_a_fresh_render() {
-        use effectcraft_engine::Session;
-        use effectcraft_engine::render::NoFootage;
-        use serde_json::json;
-        // Cache every frame of `comp`, run `edit`, check the frames kept against fresh renders.
-        fn kept(s: &mut Session, comp: ItemId, edit: serde_json::Value) -> Vec<i64> {
-            let (fr, n) = s.project.comp(comp).map(|c| (c.frame_rate, c.frame_rate.frame_at(c.duration))).unwrap();
-            let f = Frames::default();
-            let before = f.content_of(&s.project, s.revision, comp);
-            (0..n).for_each(|i| insert(&f, key(before, i, 0)));
-            let old = s.project.clone();
-            s.execute(edit["cmd"].as_str().unwrap(), edit["params"].clone()).unwrap();
-            let after = f.content_of(&s.project, s.revision, comp);
-            let kept: Vec<i64> = (0..n).filter(|&i| f.is_cached(&key(after, i, 0))).collect();
-            let render = |p, i| Renderer::new(p, &NoFootage, RenderOpts::default()).comp_frame(comp, fr.tick_of(i));
-            for &i in &kept {
-                assert_eq!(render(&old, i), render(&s.project, i), "kept frame {i} draws other pixels now");
-            }
-            kept
-        }
-        let id = |v: serde_json::Value, k: &str| v[k].as_u64().unwrap();
-        let mut s = Session::default();
-
-        // Solo on a 2–3 s layer hides the 10 s underlay everywhere; turning it off shows it again.
-        let comp = ItemId(id(s.execute("comp.new", json!({"name": "Solo", "width": 8, "height": 8, "duration": 10})).unwrap(), "comp"));
-        s.execute("layer.newSolid", json!({"comp": comp.0, "color": "#ff0000"})).unwrap();
-        let short = id(s.execute("layer.newSolid", json!({"comp": comp.0, "color": "#00ff00"})).unwrap(), "layer");
-        s.execute("layer.timing", json!({"layers": [short], "in": 2, "out": 3})).unwrap();
-        let solo = |on: bool| json!({"cmd": "layer.setSwitch", "params": {"layers": [short], "switch": "solo", "value": on}});
-        assert_eq!(kept(&mut s, comp, solo(true)), Vec::<i64>::new());
-        assert_eq!(kept(&mut s, comp, solo(false)), Vec::<i64>::new());
-
-        // A 2–3 s camera over a 4 s motion-blurred 3D layer, shutter 720° at phase 360°: a frame
-        // samples 1 to 3 frames ahead, so moving the camera reaches the 3 frames before it.
-        let comp = ItemId(id(
-            s.execute("comp.new", json!({"name": "Cam", "width": 16, "height": 16, "duration": 4, "frameRate": 30, "shutterAngle": 720, "shutterPhase": 360}))
-                .unwrap(),
-            "comp",
-        ));
-        let plane = id(s.execute("layer.newSolid", json!({"comp": comp.0, "color": "#ff0000"})).unwrap(), "layer");
-        for sw in ["threeD", "motionBlur"] {
-            s.execute("layer.setSwitch", json!({"layers": [plane], "switch": sw, "value": true})).unwrap();
-        }
-        let cam = id(s.execute("layer.newCamera", json!({"comp": comp.0})).unwrap(), "layer");
-        s.execute("layer.timing", json!({"layers": [cam], "in": 2, "out": 3})).unwrap();
-        let moved =
-            kept(&mut s, comp, json!({"cmd": "prop.set", "params": {"comp": comp.0, "layer": cam, "path": "transform/position", "value": [40, 8, -30]}}));
-        assert!(moved.contains(&0) && moved.contains(&100), "frames far from the camera stay: {moved:?}");
-        assert!(!(56..=91).any(|f| moved.contains(&f)), "frames whose shutter samples the camera render again: {moved:?}");
-    }
-
-    #[test]
-    fn short_solid_additions_and_removals_keep_unaffected_frames() {
-        use effectcraft_engine::Session;
-        use serde_json::json;
-        let mut s = Session::default();
-        let comp = ItemId(s.execute("comp.new", json!({"width": 8, "height": 8, "frameRate": 30, "duration": 20})).unwrap()["comp"].as_u64().unwrap());
-        s.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap();
-        let f = Frames::default();
-        let cache_all = |s: &Session| {
-            let content = f.content_of(&s.project, s.revision, comp);
-            (0..600).for_each(|n| insert(&f, key(content, n, 0)));
-        };
-        let cached = |s: &Session| f.cached_frames(&key(f.content_of(&s.project, s.revision, comp), 0, 0));
-        // 2–3 s, a quarter frame of the default shutter and a frame of rounding either side.
-        let kept: Vec<i64> = (0..=57).chain(92..600).collect();
-        cache_all(&s);
-        let solid = s.execute("layer.newSolid", json!({"color": "#00ff00"})).unwrap()["layer"].as_u64().unwrap();
-        s.execute("layer.timing", json!({"layers": [solid], "in": 2, "out": 3})).unwrap();
-        assert_eq!(cached(&s), kept, "adding a source invalidates only frames 58..=91");
-        cache_all(&s);
-        s.execute("edit.undo", json!({})).unwrap();
-        s.execute("edit.undo", json!({})).unwrap();
-        assert_eq!(cached(&s), (0..600).collect::<Vec<_>>(), "undoing the addition restores every frame");
-        s.execute("edit.redo", json!({})).unwrap();
-        s.execute("edit.redo", json!({})).unwrap();
-        assert_eq!(cached(&s), (0..600).collect::<Vec<_>>(), "redoing the addition restores every frame");
-        s.execute("edit.clear", json!({"layers": [solid]})).unwrap();
-        assert_eq!(cached(&s), kept, "removing its layer invalidates the same span");
-    }
-
-    #[test]
-    fn adding_a_source_does_not_hide_changes_to_existing_dependencies() {
-        use effectcraft_engine::Session;
-        use serde_json::json;
-        for (command, params) in [
-            ("layer.settings", json!({"comp": "Outer", "layer": "Underlay", "color": "#0000ff"})),
-            ("prop.set", json!({"comp": "Inner", "layer": "Inner solid", "path": "transform/opacity", "value": 40})),
-        ] {
-            let mut s = Session::default();
-            let comp = ItemId(
-                s.execute("comp.new", json!({"name": "Outer", "width": 8, "height": 8, "frameRate": 30, "duration": 20})).unwrap()["comp"].as_u64().unwrap(),
-            );
-            s.execute("layer.newSolid", json!({"name": "Underlay", "color": "#ff0000"})).unwrap();
-            s.execute("comp.new", json!({"name": "Inner", "width": 8, "height": 8, "duration": 20})).unwrap();
-            s.execute("layer.newSolid", json!({"name": "Inner solid", "color": "#00ff00"})).unwrap();
-            s.execute("comp.open", json!({"comp": "Outer"})).unwrap();
-            s.execute("layer.addItem", json!({"item": "Inner"})).unwrap();
-            let f = Frames::default();
-            let before = f.content_of(&s.project, s.revision, comp);
-            (0..600).for_each(|n| insert(&f, key(before, n, 0)));
-            s.execute(command, params).unwrap();
-            let solid = s.execute("layer.newSolid", json!({"color": "#ffffff"})).unwrap()["layer"].as_u64().unwrap();
-            s.execute("layer.timing", json!({"layers": [solid], "in": 2, "out": 3})).unwrap();
-            let after = f.content_of(&s.project, s.revision, comp);
-            assert!(f.cached_frames(&key(after, 0, 0)).is_empty(), "{command} changes pixels outside the added layer");
-        }
-    }
-
-    #[test]
-    fn markers_keep_the_frames() {
-        use effectcraft_engine::Session;
-        use serde_json::json;
-        let mut s = Session::default();
-        let id = |v: serde_json::Value, k: &str| v[k].as_u64().unwrap();
-        let outer = ItemId(id(s.execute("comp.new", json!({"name": "Outer", "width": 8, "height": 8, "duration": 1})).unwrap(), "comp"));
-        let solid = id(s.execute("layer.newSolid", json!({"comp": outer.0, "color": "#ff0000"})).unwrap(), "layer");
-        let f = Frames::default();
-        let at = |s: &Session| f.content_of(&s.project, s.revision, outer);
-        let o0 = at(&s);
-        s.execute("layer.addMarker", json!({"comp": outer.0, "layers": [solid], "time": 0.5, "comment": "beat"})).unwrap();
-        assert_eq!(at(&s), o0, "a marker changes no pixels, so it keeps the frames");
-    }
-
-    #[test]
-    fn markers_count_when_an_expression_can_read_them() {
-        use effectcraft_engine::Session;
-        use serde_json::json;
-        let mut s = Session::default();
-        let id = |v: serde_json::Value, k: &str| v[k].as_u64().unwrap();
-        let outer = ItemId(id(s.execute("comp.new", json!({"name": "Outer", "width": 8, "height": 8, "duration": 1})).unwrap(), "comp"));
-        let solid = id(s.execute("layer.newSolid", json!({"comp": outer.0, "color": "#ff0000"})).unwrap(), "layer");
-        s.execute("prop.setExpression", json!({"comp": outer.0, "layer": solid, "path": "transform/opacity", "expression": "1"})).unwrap();
-        let f = Frames::default();
-        let at = |s: &Session| f.content_of(&s.project, s.revision, outer);
-        let o0 = at(&s);
-        s.execute("layer.addMarker", json!({"comp": outer.0, "layers": [solid], "time": 0.5, "comment": "beat"})).unwrap();
-        assert_ne!(at(&s), o0, "an expression can read the marker, so the frames change");
-    }
-}
+mod tests;
diff --git a/crates/ui-egui/src/frames/tests.rs b/crates/ui-egui/src/frames/tests.rs
new file mode 100644
index 000000000..6da1dc269
--- /dev/null
+++ b/crates/ui-egui/src/frames/tests.rs
@@ -0,0 +1,927 @@
+use super::*;
+
+struct ProbeDisk {
+    keys: Mutex<HashSet<u128>>,
+    probes: std::sync::atomic::AtomicUsize,
+}
+
+impl RemoteFrames for ProbeDisk {
+    fn slots(&self) -> usize {
+        0
+    }
+
+    fn disk(&self) -> bool {
+        true
+    }
+
+    fn disk_contains(&self, key: u128) -> bool {
+        self.probes.fetch_add(1, Ordering::Relaxed);
+        self.keys.lock().unwrap().contains(&key)
+    }
+
+    fn start(&self, _: RemoteJob, _: RemoteDone) {}
+}
+
+fn disk_fixture(stored_frames: &[i64]) -> (Frames, RenderSource, FrameKey, RenderOpts, Arc<ProbeDisk>, u128) {
+    let mut session = effectcraft_engine::Session::default();
+    session.execute("comp.new", serde_json::json!({"width": 32, "height": 18, "duration": 1})).unwrap();
+    let comp = session.active_comp_id().unwrap();
+    let opts = RenderOpts::default();
+    let content = 1234;
+    let mut base = key(1, 0, opts_hash(&opts));
+    base.revision = 7;
+    base.comp = comp.0;
+    let disk = Arc::new(ProbeDisk { keys: Mutex::new(HashSet::new()), probes: 0.into() });
+    disk.keys.lock().unwrap().extend(stored_frames.iter().map(|frame| disk_cache::frame_key(content, *frame, base.scale, base.view ^ opts_hash(&opts))));
+    let mut frames = Frames::default();
+    frames.set_remote(Some(disk.clone()));
+    frames.content_keys.lock().unwrap().insert((base.revision, base.comp, 0), content);
+    let source = RenderSource {
+        project: session.project.clone(),
+        footage: session.footage.clone(),
+        expr: None,
+        layer_cache: Arc::default(),
+        gpu: None,
+        gpu_display: false,
+        disk: None,
+    };
+    (frames, source, base, opts, disk, content)
+}
+
+#[cfg(not(target_arch = "wasm32"))]
+#[test]
+fn disk_indicator_does_not_hash_on_ui_thread_and_coalesces_edits() {
+    use std::sync::mpsc;
+    use std::time::{Duration, Instant};
+    struct Disk(u128);
+    impl RemoteFrames for Disk {
+        fn slots(&self) -> usize {
+            1
+        }
+        fn disk(&self) -> bool {
+            true
+        }
+        fn disk_contains(&self, key: u128) -> bool {
+            self.0 == key
+        }
+        fn start(&self, _: RemoteJob, done: RemoteDone) {
+            done(Err("test has no renderer".into()));
+        }
+    }
+    let mut s = effectcraft_engine::Session::default();
+    s.execute("comp.new", serde_json::json!({"width":32,"height":18,"duration":1})).unwrap();
+    let cid = s.active_comp_id().unwrap();
+    let opts = RenderOpts::default();
+    let stored = disk_cache::frame_key(disk_cache::comp_content_key(&s.project, cid), 2, 1000, opts_hash(&opts));
+    let mut frames = Frames { pool: Some(rayon::ThreadPoolBuilder::new().num_threads(1).build().unwrap()), ..Default::default() };
+    frames.set_remote(Some(Arc::new(Disk(stored))));
+    let (entered, started) = mpsc::channel();
+    let (release, wait) = mpsc::channel();
+    frames.pool.as_ref().unwrap().spawn(move || {
+        entered.send(()).unwrap();
+        wait.recv_timeout(Duration::from_secs(5)).unwrap();
+    });
+    started.recv_timeout(Duration::from_secs(3)).unwrap();
+    let src = RenderSource {
+        project: s.project.clone(),
+        footage: s.footage.clone(),
+        expr: None,
+        layer_cache: Arc::default(),
+        gpu: None,
+        gpu_display: false,
+        disk: None,
+    };
+    let mut base = key(1, 0, 0);
+    base.comp = cid.0;
+    for revision in 1..50 {
+        base.revision = revision;
+        assert!(frames.disk_frames(&src, &base, 0..30, &opts).is_empty());
+    }
+    assert!(frames.content_keys.lock().unwrap().is_empty(), "painting computed a content hash while the worker was blocked");
+    assert_eq!(frames.content_key_jobs.lock().unwrap().pending.len(), 1);
+    release.send(()).unwrap();
+    let until = Instant::now() + Duration::from_secs(3);
+    while !frames.content_keys.lock().unwrap().contains_key(&(base.revision, base.comp, 0)) {
+        assert!(Instant::now() < until);
+        std::thread::sleep(Duration::from_millis(1));
+    }
+    assert_eq!(frames.disk_frames(&src, &base, 0..30, &opts), vec![2], "the blue indicator must return once its key is ready");
+    assert_eq!(frames.content_keys.lock().unwrap().len(), 1, "superseded revisions were hashed");
+}
+
+#[test]
+fn disk_indicator_range_tracks_live_membership() {
+    let (frames, src, base, opts, disk, _) = disk_fixture(&[10, 12]);
+    assert_eq!(frames.disk_frames(&src, &base, 10..13, &opts), vec![10, 12]);
+    assert_eq!(disk.probes.load(Ordering::Relaxed), 3);
+
+    disk.keys.lock().unwrap().insert(disk_cache::frame_key(1234, 11, base.scale, base.view ^ opts_hash(&opts)));
+    assert_eq!(frames.disk_frames(&src, &base, 10..13, &opts), vec![10, 11, 12]);
+
+    insert(&frames, FrameKey { frame: 11, ..base });
+    disk.probes.store(0, Ordering::Relaxed);
+    assert_eq!(frames.disk_frames(&src, &base, 10..13, &opts), vec![10, 12]);
+    assert_eq!(disk.probes.load(Ordering::Relaxed), 2);
+
+    disk.keys.lock().unwrap().remove(&disk_cache::frame_key(1234, 12, base.scale, base.view ^ opts_hash(&opts)));
+    assert_eq!(frames.disk_frames(&src, &base, 10..13, &opts), vec![10]);
+
+    let mut revised = base;
+    revised.revision += 1;
+    frames.content_keys.lock().unwrap().insert((revised.revision, revised.comp, 0), 5678);
+    assert!(frames.disk_frames(&src, &revised, 10..13, &opts).is_empty());
+
+    let changed = FrameKey { scale: base.scale + 1, ..base };
+    assert!(frames.disk_frames(&src, &changed, 10..13, &opts).is_empty());
+    let changed = FrameKey { view: base.view + 1, ..base };
+    assert!(frames.disk_frames(&src, &changed, 10..13, &opts).is_empty());
+    assert!(frames.disk_frames(&src, &base, 10..13, &RenderOpts { draft: true, ..opts }).is_empty());
+}
+
+#[test]
+fn disk_indicator_range_is_bounded() {
+    let (frames, src, base, opts, disk, _) = disk_fixture(&[0, 1, 99_999]);
+    assert_eq!(frames.disk_frames(&src, &base, -5..2, &opts), vec![0, 1]);
+    assert_eq!(disk.probes.load(Ordering::Relaxed), 2);
+    disk.probes.store(0, Ordering::Relaxed);
+    assert_eq!(frames.disk_frames(&src, &base, 99_999..i64::MAX, &opts), vec![99_999]);
+    assert_eq!(disk.probes.load(Ordering::Relaxed), 1);
+    disk.probes.store(0, Ordering::Relaxed);
+    assert!(frames.disk_frames(&src, &base, 2..2, &opts).is_empty());
+    // Written as a struct literal: `3..2` trips clippy::reversed_empty_ranges.
+    let reversed = std::ops::Range { start: 3, end: 2 };
+    assert!(frames.disk_frames(&src, &base, reversed, &opts).is_empty());
+    assert_eq!(disk.probes.load(Ordering::Relaxed), 0);
+}
+
+/// Frames larger than the texture limit are averaged down by a whole factor (#201: an
+/// 11000×2200 comp at Full resolution against an 8192 limit).
+#[test]
+fn frames_over_the_texture_limit_are_averaged_down() {
+    assert_eq!(fitted_size([11000, 2200], 8192), [5500, 1100]);
+    assert_eq!(fitted_size([8192, 100], 8192), [8192, 100]);
+    assert_eq!(fitted_size([30000, 30000], 16384), [15000, 15000]);
+    assert_eq!(fitted_size([0, 0], 0), [0, 0]);
+    // 5×2 (three columns of white, then black) into 2 px: 3×2 blocks (the last one 2×2).
+    let w = egui::Color32::WHITE;
+    let b = egui::Color32::from_rgba_premultiplied(0, 0, 0, 255);
+    let img = egui::ColorImage::new([5, 2], vec![w, w, w, b, b, w, w, w, b, b]);
+    let out = fit_texture(img.clone(), 2);
+    assert_eq!(out.size, [2, 1]);
+    assert_eq!(out.pixels, vec![w, b]);
+    assert_eq!(fit_texture(img.clone(), 5).pixels, img.pixels);
+    let mixed = fit_texture(egui::ColorImage::new([2, 1], vec![w, b]), 1);
+    assert_eq!(mixed.pixels, vec![egui::Color32::from_rgba_premultiplied(128, 128, 128, 255)]);
+}
+
+#[test]
+fn retirement_reaches_existing_workers_and_keeps_cpu_frames_and_completion_live() {
+    let frames = Frames::default();
+    let worker = frames.worker();
+    let first = key(1, 0, 0);
+    insert(&frames, first);
+    frames.retire_gpu();
+    assert!(worker.gpu_retired.load(Ordering::Acquire), "already queued workers share retirement");
+    assert!(frames.is_cached(&first), "healthy materialized CPU frames survive");
+    let next = key(1, 1, 0);
+    frames.inflight.lock().unwrap().insert(next);
+    frames.queue.lock().unwrap().running.insert(next);
+    worker.finish_key(next, false, img(), web_time::Instant::now());
+    assert!(frames.is_cached(&next), "CPU retry can still publish");
+    assert_eq!(frames.inflight(), 0);
+    assert!(frames.queue.lock().unwrap().running.is_empty());
+}
+
+fn key(content: u64, frame: i64, opts: u64) -> FrameKey {
+    FrameKey { revision: content, content, comp: 1, frame, scale: 1000, view: 0, opts }
+}
+
+fn img() -> FrameImage {
+    FrameImage::Cpu(Arc::new(egui::ColorImage::new([2, 2], vec![egui::Color32::BLACK; 4])))
+}
+
+fn insert(f: &Frames, k: FrameKey) {
+    f.cache.lock().unwrap().insert(k, img());
+}
+
+/// A frame whose render panics (a GPU out of memory used to, on every frame thread) is
+/// released, not left "in progress" forever, so the viewer can ask for it again (#106).
+#[test]
+fn a_frame_whose_render_panics_is_released() {
+    use effectcraft_engine::Session;
+    use effectcraft_engine::project::{Footage, FootageKind};
+    use effectcraft_engine::render::Image;
+    use serde_json::json;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+    #[derive(Default)]
+    struct Explodes(AtomicUsize);
+    impl FootageSource for Explodes {
+        fn frame(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<Image>> {
+            self.0.fetch_add(1, Ordering::SeqCst);
+            panic!("a decoder bug");
+        }
+    }
+    let mut s = Session::default();
+    let cid = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
+    let clip = Footage { kind: FootageKind::Still, width: 8, height: 8, has_video: true, ..Default::default() };
+    let item = Arc::make_mut(&mut s.project).add_item("clip.png", Default::default(), None, ItemKind::Footage(clip));
+    s.execute("layer.addItem", json!({"item": item.0})).unwrap();
+    let footage = Arc::new(Explodes::default());
+    let src = RenderSource {
+        project: s.project.clone(),
+        footage: footage.clone(),
+        expr: None,
+        layer_cache: Arc::default(),
+        gpu: None,
+        gpu_display: false,
+        disk: None,
+    };
+    let f = Frames::default();
+    let key = FrameKey { revision: s.revision, content: f.content_of(&s.project, s.revision, cid), ..key(0, 0, 0) };
+    let key = FrameKey { comp: cid.0, ..key };
+    f.request(&src, key, cid, Tick::ZERO, RenderOpts::default());
+    for _ in 0..1000 {
+        if f.inflight() == 0 {
+            break;
+        }
+        std::thread::sleep(std::time::Duration::from_millis(5));
+    }
+    assert!(footage.0.load(Ordering::SeqCst) > 0, "the render reached the footage");
+    assert_eq!(f.inflight(), 0, "released");
+    assert!(!f.is_cached(&key));
+}
+
+/// #647: a pool thread waiting inside a render (on a parallel loop) never starts another
+/// frame render on top of it. Dragging a layer queues a frame every UI frame; renders used to
+/// nest on every thread, each holding its buffers, until memory ran out.
+#[test]
+fn a_waiting_render_never_starts_another_on_its_thread() {
+    use effectcraft_engine::Session;
+    use effectcraft_engine::project::{Footage, FootageKind};
+    use effectcraft_engine::render::Image;
+    use effectcraft_engine::time::FrameRate;
+    use serde_json::json;
+    use std::cell::Cell;
+    use std::sync::atomic::AtomicUsize;
+    thread_local! {
+        static DEPTH: Cell<usize> = const { Cell::new(0) };
+    }
+    /// A decoder that works in parallel, as the renderer does: its thread joins the loop and
+    /// may wait for the parts other threads took.
+    #[derive(Default)]
+    struct Parallel {
+        calls: AtomicUsize,
+        deepest: AtomicUsize,
+    }
+    impl FootageSource for Parallel {
+        fn frame(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<Image>> {
+            let d = DEPTH.get() + 1;
+            DEPTH.set(d);
+            self.deepest.fetch_max(d, Ordering::SeqCst);
+            self.calls.fetch_add(1, Ordering::SeqCst);
+            (0..64).into_par_iter().for_each(|_| std::thread::sleep(std::time::Duration::from_millis(1)));
+            DEPTH.set(d - 1);
+            Some(Arc::new(Image::new(4, 4)))
+        }
+    }
+    let mut s = Session::default();
+    let cid = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 10})).unwrap()["comp"].as_u64().unwrap());
+    let clip = Footage {
+        kind: FootageKind::Video,
+        width: 4,
+        height: 4,
+        has_video: true,
+        frame_rate: FrameRate::FPS_30,
+        duration: Tick::from_seconds_f64(10.0),
+        ..Default::default()
+    };
+    let item = Arc::make_mut(&mut s.project).add_item("clip.mov", Default::default(), None, ItemKind::Footage(clip));
+    s.execute("layer.addItem", json!({"item": item.0})).unwrap();
+    let footage = Arc::new(Parallel::default());
+    let src = RenderSource {
+        project: s.project.clone(),
+        footage: footage.clone(),
+        expr: None,
+        layer_cache: Arc::default(),
+        gpu: None,
+        gpu_display: false,
+        disk: None,
+    };
+    let f = Frames::default();
+    let content = f.content_of(&s.project, s.revision, cid);
+    let frames = 60;
+    for frame in 0..frames {
+        let key = FrameKey { revision: s.revision, content, comp: cid.0, frame, scale: 1000, view: 0, opts: 0 };
+        f.request(&src, key, cid, FrameRate::FPS_30.tick_of(frame), RenderOpts::default());
+    }
+    for _ in 0..4000 {
+        if f.inflight() == 0 {
+            break;
+        }
+        std::thread::sleep(std::time::Duration::from_millis(5));
+    }
+    assert_eq!(f.inflight(), 0, "every queued frame rendered");
+    assert!(footage.calls.load(Ordering::SeqCst) >= frames as usize);
+    assert_eq!(footage.deepest.load(Ordering::SeqCst), 1, "renders nested on a waiting thread");
+}
+
+/// #329: scrubbing a long movie, the viewer frame of every step the pointer passed started
+/// rendering and seeked the movie's decoder in turn; the frame under the pointer waited for
+/// all of them. A newer viewer frame of another time calls off the one rendering, which is
+/// not cached (its footage may be missing).
+#[test]
+fn a_newer_viewer_frame_calls_off_the_one_rendering() {
+    use effectcraft_engine::Session;
+    use effectcraft_engine::project::{Footage, FootageKind};
+    use effectcraft_engine::render::Image;
+    use effectcraft_engine::time::FrameRate;
+    use serde_json::json;
+    use std::cell::RefCell;
+    thread_local! {
+        static CANCEL: RefCell<Option<Arc<AtomicBool>>> = const { RefCell::new(None) };
+    }
+    /// A movie whose first frames take a long seek, which a called-off read gives up.
+    #[derive(Default)]
+    struct Seeking {
+        seeking: AtomicBool,
+        called_off: AtomicBool,
+    }
+    impl FootageSource for Seeking {
+        fn cancellable(&self, cancel: &Arc<AtomicBool>, f: &mut dyn FnMut()) {
+            let prev = CANCEL.replace(Some(cancel.clone()));
+            f();
+            CANCEL.set(prev);
+        }
+        fn frame(&self, _: ItemId, _: &Footage, t: Tick) -> Option<Arc<Image>> {
+            if t < Tick::from_seconds_f64(0.25) {
+                self.seeking.store(true, Ordering::SeqCst);
+                for _ in 0..1000 {
+                    if CANCEL.with_borrow(|c| c.as_ref().is_some_and(|c| c.load(Ordering::SeqCst))) {
+                        self.called_off.store(true, Ordering::SeqCst);
+                        return None;
+                    }
+                    std::thread::sleep(std::time::Duration::from_millis(5));
+                }
+            }
+            Some(Arc::new(Image::new(4, 4)))
+        }
+    }
+    let mut s = Session::default();
+    let cid = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 10})).unwrap()["comp"].as_u64().unwrap());
+    let clip = Footage {
+        kind: FootageKind::Video,
+        width: 4,
+        height: 4,
+        has_video: true,
+        frame_rate: FrameRate::FPS_30,
+        duration: Tick::from_seconds_f64(10.0),
+        ..Default::default()
+    };
+    let item = Arc::make_mut(&mut s.project).add_item("clip.mov", Default::default(), None, ItemKind::Footage(clip));
+    s.execute("layer.addItem", json!({"item": item.0})).unwrap();
+    let footage = Arc::new(Seeking::default());
+    let src = RenderSource {
+        project: s.project.clone(),
+        footage: footage.clone(),
+        expr: None,
+        layer_cache: Arc::default(),
+        gpu: None,
+        gpu_display: false,
+        disk: None,
+    };
+    let f = Frames::default();
+    let content = f.content_of(&s.project, s.revision, cid);
+    let key = |frame| FrameKey { revision: s.revision, content, comp: cid.0, frame, scale: 1000, view: 0, opts: 0 };
+    f.request_urgent(&src, key(0), cid, Tick::ZERO, RenderOpts::default());
+    for _ in 0..1000 {
+        if footage.seeking.load(Ordering::SeqCst) {
+            break;
+        }
+        std::thread::sleep(std::time::Duration::from_millis(2));
+    }
+    assert!(footage.seeking.load(Ordering::SeqCst), "the first frame's render reached the footage");
+    f.request_urgent(&src, key(150), cid, FrameRate::FPS_30.tick_of(150), RenderOpts::default());
+    for _ in 0..1000 {
+        if f.inflight() == 0 {
+            break;
+        }
+        std::thread::sleep(std::time::Duration::from_millis(5));
+    }
+    assert!(footage.called_off.load(Ordering::SeqCst), "the superseded frame's seek ran on");
+    assert!(f.is_cached(&key(150)), "the newest frame rendered");
+    assert!(!f.is_cached(&key(0)), "a called-off frame is not cached");
+    assert_eq!(f.inflight(), 0, "released");
+}
+
+/// #284: scrubbing asks for a viewer frame at every step; a newer one drops the comp's viewer
+/// frames still waiting (they would all render first), but not prefetch frames or another
+/// comp's viewer frame.
+#[test]
+fn a_newer_viewer_frame_drops_the_ones_still_waiting() {
+    /// Starts nothing, so every request stays queued.
+    struct Idle;
+    impl RemoteFrames for Idle {
+        fn slots(&self) -> usize {
+            0
+        }
+        fn start(&self, _: RemoteJob, _: RemoteDone) {}
+    }
+    let mut f = Frames::default();
+    f.set_remote(Some(Arc::new(Idle)));
+    let src = RenderSource {
+        project: Arc::default(),
+        footage: Arc::new(effectcraft_engine::render::NoFootage),
+        expr: None,
+        layer_cache: Arc::default(),
+        gpu: None,
+        gpu_display: false,
+        disk: None,
+    };
+    let request = |k: FrameKey, urgent: bool| f.request_with(&src, k, ItemId(k.comp), Tick::ZERO, RenderOpts::default(), urgent);
+    let other = FrameKey { comp: 2, ..key(1, 0, 0) };
+    request(other, true);
+    request(key(1, 20, 0), false);
+    for frame in 0..10 {
+        request(key(1, frame, 0), true);
+    }
+    let mut queued: Vec<(u64, i64, bool)> = f.queue.lock().unwrap().jobs.iter().map(|j| (j.key.comp, j.key.frame, j.urgent)).collect();
+    queued.sort();
+    assert_eq!(queued, [(1, 9, true), (1, 20, false), (2, 0, false)]);
+    assert_eq!(f.inflight(), 3, "dropped frames aren't in flight: the viewer can ask again");
+}
+
+/// Each time the GPU runs out of memory, half as many GPU frames are kept, down to a floor.
+#[test]
+fn running_out_of_video_memory_halves_the_gpu_frame_budget() {
+    let f = Frames::default();
+    let mut c = f.cache.lock().unwrap();
+    assert_eq!(c.gpu_budget, GPU_BUDGET);
+    c.gpu_out_of_memory();
+    assert_eq!(c.gpu_budget, GPU_BUDGET / 2);
+    for _ in 0..20 {
+        c.gpu_out_of_memory();
+    }
+    assert_eq!(c.gpu_budget, MIN_GPU_BUDGET);
+}
+
+#[test]
+fn least_recently_shown_frames_go_first() {
+    let f = Frames::default();
+    f.set_budget(3 * 16);
+    for i in 0..3 {
+        insert(&f, key(1, i, 0));
+    }
+    // Frame 0 is shown again, so frame 1 is now the oldest.
+    assert!(f.get(&key(1, 0, 0)).is_some());
+    insert(&f, key(1, 3, 0));
+    assert!(f.is_cached(&key(1, 0, 0)) && !f.is_cached(&key(1, 1, 0)));
+    assert!(f.is_cached(&key(1, 2, 0)) && f.is_cached(&key(1, 3, 0)));
+}
+
+fn playhead(cur: i64, looping: bool) -> Playhead {
+    Playhead { series: key(1, 0, 0), cur, start: 0, end: 99, step: 1, looping }
+}
+
+/// #595: a playing preview's cache is full. The frames just ahead of the playhead were
+/// rendered before the ones just shown, so plain LRU evicted them first and the preview
+/// played into a gap. Frames the preview no longer reaches go first, then the ones it
+/// reaches last.
+#[test]
+fn a_full_cache_keeps_the_frames_just_ahead_of_the_playhead() {
+    let f = Frames::default();
+    f.set_budget(4 * 16);
+    // Prefetch rendered 11..=13, then 10 was shown (the most recently used).
+    for i in [11, 12, 13, 10] {
+        insert(&f, key(1, i, 0));
+    }
+    let cached = |f: &Frames| f.cached_frames(&key(1, 0, 0));
+    f.set_playhead(Some(playhead(10, false)));
+    // The next frame rendered is the one the preview reaches last: the frames just ahead stay.
+    insert(&f, key(1, 14, 0));
+    assert_eq!(cached(&f), [10, 11, 12, 13]);
+    // Without looping, a frame behind the playhead goes before any frame ahead of it.
+    f.set_playhead(Some(playhead(12, false)));
+    insert(&f, key(1, 14, 0));
+    assert_eq!(cached(&f), [10, 12, 13, 14]);
+    // Looping, the frame just behind is the one reached last.
+    f.set_playhead(Some(playhead(13, true)));
+    insert(&f, key(1, 0, 0));
+    assert_eq!(cached(&f), [0, 10, 13, 14]);
+    // Stopped: least recently shown first again.
+    f.set_playhead(None);
+    insert(&f, key(1, 50, 0));
+    assert!(!f.is_cached(&key(1, 13, 0)) && f.is_cached(&key(1, 50, 0)));
+}
+
+/// A frame source that queues jobs and never renders them: the tests check the queue.
+struct Idle;
+impl RemoteFrames for Idle {
+    fn slots(&self) -> usize {
+        0
+    }
+    fn start(&self, _: RemoteJob, _: RemoteDone) {}
+}
+
+fn idle_source() -> RenderSource {
+    RenderSource {
+        project: Arc::default(),
+        footage: Arc::new(effectcraft_engine::render::NoFootage),
+        expr: None,
+        layer_cache: Arc::default(),
+        gpu: None,
+        gpu_display: false,
+        disk: None,
+    }
+}
+
+/// #595: prefetch renders the frames the preview reaches first, whatever order they were
+/// asked for in (a frame evicted and asked for again waited behind every frame further
+/// ahead); queued frames the preview no longer reaches are dropped and not left in flight.
+#[test]
+fn prefetch_renders_the_frames_the_playhead_reaches_first() {
+    let mut f = Frames::default();
+    f.set_remote(Some(Arc::new(Idle)));
+    let src = idle_source();
+    for frame in [40, 30, 20, 5, 12, 11] {
+        f.request(&src, key(1, frame, 0), ItemId(1), Tick::ZERO, RenderOpts::default());
+    }
+    f.request(&src, FrameKey { comp: 2, ..key(1, 1, 0) }, ItemId(2), Tick::ZERO, RenderOpts::default());
+    f.set_playhead(Some(playhead(10, false)));
+    let mut order = vec![];
+    loop {
+        let mut q = f.queue.lock().unwrap();
+        let Some(i) = q.best() else { break };
+        let j = q.jobs.swap_remove(i);
+        order.push((j.key.comp, j.key.frame));
+    }
+    assert_eq!(order, [(1, 11), (1, 12), (1, 20), (1, 30), (1, 40), (2, 1)]);
+    assert_eq!(f.inflight(), 6, "frame 5, behind the playhead, is no longer in flight");
+}
+
+/// The cache is full. A zoom (or preview-resolution) change left the frames of the old
+/// size to the plain least-recently-shown order, so the frames of the zoom the viewer is back
+/// at went before the ones of the abandoned zoom. The other size's frames go first, then the
+/// order is as before.
+#[test]
+fn a_size_change_evicts_frames_of_other_sizes_first() {
+    let mut f = Frames::default();
+    f.set_remote(Some(Arc::new(Idle)));
+    f.set_budget(4 * 16);
+    let at = |frame, scale| FrameKey { scale, ..key(1, frame, 0) };
+    // 100% (frames 0..=1) is cached, then 50% (2..=3): the 100% frames are the oldest.
+    for (frame, scale) in [(0, 1000), (1, 1000), (2, 500), (3, 500)] {
+        insert(&f, at(frame, scale));
+    }
+    // A passive viewer at 50% asks for a frame: that doesn't change which size is kept.
+    f.request(&idle_source(), at(9, 500), ItemId(1), Tick::ZERO, RenderOpts::default());
+    // Back at 100%: the viewer asks for frame 4.
+    f.request_urgent(&idle_source(), at(4, 1000), ItemId(1), Tick::ZERO, RenderOpts::default());
+    f.request(&idle_source(), at(10, 500), ItemId(1), Tick::ZERO, RenderOpts::default());
+    insert(&f, at(4, 1000));
+    assert!(
+        f.is_cached(&at(0, 1000)) && f.is_cached(&at(1, 1000)) && !f.is_cached(&at(2, 500)) && f.is_cached(&at(3, 500)),
+        "the first frame of the old size goes, not the cached ones of the current size"
+    );
+    insert(&f, at(5, 1000));
+    assert!(!f.is_cached(&at(3, 500)), "then the last frame of the old size");
+    assert_eq!(f.cached_frames(&at(0, 1000)), [0, 1, 4, 5]);
+    // No other size left: least recently shown first again.
+    insert(&f, at(6, 1000));
+    assert_eq!(f.cached_frames(&at(0, 1000)), [1, 4, 5, 6]);
+}
+
+#[test]
+fn frames_are_keyed_by_content_and_series_are_kept_apart() {
+    let f = Frames::default();
+    insert(&f, key(1, 0, 0));
+    insert(&f, key(2, 0, 0));
+    insert(&f, key(2, 1, 7));
+    // Other content or render options (Draft, shadows…) are another series.
+    assert_eq!(f.cached_frames(&key(2, 0, 0)), vec![0]);
+    assert_eq!(f.cached_frames(&key(2, 0, 7)), vec![1]);
+    // A later revision with the same content finds the frame (an edit elsewhere, an undo).
+    assert!(f.is_cached(&FrameKey { revision: 99, ..key(1, 0, 0) }));
+    assert!(!f.is_cached(&key(3, 0, 0)));
+}
+
+#[test]
+fn live_edits_present_the_newest_completed_revision_without_going_backwards() {
+    let f = Frames::default();
+    let shown = key(1, 0, 0);
+    let newest = key(3, 0, 0);
+    let wanted = key(5, 0, 0);
+    insert(&f, shown);
+    insert(&f, newest);
+    insert(&f, key(2, 0, 0)); // Older worker finishes after the newer one.
+    let displayed = f.get_for_viewer(&wanted, Some(&shown)).unwrap().0;
+    assert_eq!(displayed, newest);
+    assert!(f.get_for_viewer(&wanted, Some(&displayed)).is_none(), "never replay an older completion");
+    insert(&f, wanted);
+    assert_eq!(f.get_for_viewer(&wanted, Some(&displayed)).unwrap().0, wanted, "settle on the exact final edit");
+    // Undo reuses the content of an earlier revision immediately.
+    let undo = FrameKey { revision: 6, ..shown };
+    let reused = f.get_for_viewer(&undo, Some(&wanted)).unwrap().0;
+    assert_eq!(reused.content, shown.content);
+    assert_eq!(reused.revision, undo.revision);
+}
+
+#[test]
+fn live_edits_do_not_substitute_other_times_views_or_render_settings() {
+    let f = Frames::default();
+    let shown = key(1, 0, 0);
+    let wanted = key(3, 0, 0);
+    let done = key(2, 0, 0);
+    for mismatch in [
+        FrameKey { comp: 9, ..done },
+        FrameKey { frame: 1, ..done },
+        FrameKey { scale: 500, ..done },
+        FrameKey { view: 1, ..done },
+        FrameKey { opts: 1, ..done },
+        FrameKey { revision: 4, ..done },
+    ] {
+        f.clear();
+        insert(&f, mismatch);
+        assert!(f.get_for_viewer(&wanted, Some(&shown)).is_none(), "wrong candidate: {mismatch:?}");
+    }
+    f.clear();
+    insert(&f, done);
+    assert!(f.get_for_viewer(&wanted, None).is_none(), "no stale content on opening a viewer");
+    assert!(f.get_for_viewer(&wanted, Some(&FrameKey { comp: 9, ..shown })).is_none());
+    assert!(f.get_for_viewer(&wanted, Some(&FrameKey { frame: 1, ..shown })).is_none());
+    assert!(f.get_for_viewer(&wanted, Some(&FrameKey { view: 1, ..shown })).is_none());
+}
+
+#[test]
+fn an_edit_keeps_the_frames_of_comps_it_does_not_touch() {
+    use effectcraft_engine::Session;
+    use serde_json::json;
+    let mut s = Session::default();
+    let a = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
+    let b = ItemId(s.execute("comp.new", json!({"name": "B", "width": 8, "height": 8, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
+    let f = Frames::default();
+    let at = |s: &Session, c: ItemId| f.content_of(&s.project, s.revision, c);
+    let (a0, b0) = (at(&s, a), at(&s, b));
+    // Edit B: A's content (and frames) stay, B's change.
+    s.execute("layer.newSolid", json!({"comp": b.0, "color": "#ff0000"})).unwrap();
+    assert_eq!(at(&s, a), a0);
+    assert_ne!(at(&s, b), b0);
+    // Undo: B is back to the content its old frames were rendered for.
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(at(&s, b), b0);
+}
+
+#[test]
+fn a_long_drag_keeps_a_bounded_number_of_states() {
+    use effectcraft_engine::Session;
+    use serde_json::json;
+    let mut s = Session::default();
+    let a = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
+    let f = Frames::default();
+    let mut last = None;
+    for i in 0..200 {
+        s.execute("comp.settings", json!({"width": 8 + i, "merge": "drag"})).unwrap();
+        let k = FrameKey { content: f.content_of(&s.project, s.revision, a), ..key(0, 0, 0) };
+        insert(&f, k);
+        last = Some(k);
+    }
+    // The snapshots and the frames kept stay bounded (a dropped identity's frames go with it,
+    // so a later state that reuses its addresses can't be shown an old frame).
+    assert!(f.keepers.lock().unwrap().1.len() <= MAX_KEEPERS);
+    assert!(f.cache.lock().unwrap().map.len() <= MAX_KEEPERS);
+    assert!(f.is_cached(&last.unwrap()), "the current state's frame stays");
+}
+
+#[test]
+fn an_identity_keeps_its_comps_so_an_edit_in_place_still_changes_it() {
+    use effectcraft_engine::Session;
+    use serde_json::json;
+    let mut s = Session::default();
+    let a = ItemId(s.execute("comp.new", json!({"name": "A", "width": 8, "height": 8, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
+    // A project nothing else holds (no undo history): make_mut would edit the comp in place,
+    // at the same address, if the identity hadn't kept a snapshot holding it.
+    let mut p = Arc::new((*s.project).clone());
+    drop(s);
+    let f = Frames::default();
+    let before = f.content_of(&p, 1, a);
+    let comp = Arc::make_mut(&mut p).comp_mut(a).unwrap();
+    comp.width = 16;
+    assert_ne!(f.content_of(&p, 2, a), before);
+}
+
+/// Audio, Lock and Shy (and Hide Shy Layers) don't change pixels: toggling them, in the comp
+/// or a comp it nests, keeps its frames, also when toggled back (#103).
+#[test]
+fn audio_lock_and_shy_switches_keep_the_frames() {
+    use effectcraft_engine::Session;
+    use serde_json::json;
+    let mut s = Session::default();
+    let id = |v: serde_json::Value, k: &str| v[k].as_u64().unwrap();
+    let inner = ItemId(id(s.execute("comp.new", json!({"name": "Inner", "width": 8, "height": 8, "duration": 1})).unwrap(), "comp"));
+    let solid = id(s.execute("layer.newSolid", json!({"comp": inner.0, "color": "#ff0000"})).unwrap(), "layer");
+    let outer = ItemId(id(s.execute("comp.new", json!({"name": "Outer", "width": 8, "height": 8, "duration": 1})).unwrap(), "comp"));
+    let nested = id(s.execute("layer.addItem", json!({"comp": outer.0, "item": inner.0})).unwrap(), "layer");
+    let f = Frames::default();
+    let at = |s: &Session| f.content_of(&s.project, s.revision, outer);
+    let o0 = at(&s);
+    let switch = |s: &mut Session, comp: ItemId, layer: u64, sw: &str, v: bool| {
+        s.execute("layer.setSwitch", json!({"comp": comp.0, "layers": [layer], "switch": sw, "value": v})).unwrap();
+    };
+    for (comp, layer, sw) in [(outer, nested, "audio"), (outer, nested, "lock"), (outer, nested, "shy"), (inner, solid, "audio"), (inner, solid, "shy")] {
+        // Audio off; Lock and Shy on.
+        switch(&mut s, comp, layer, sw, sw != "audio");
+        assert_eq!(at(&s), o0, "{sw} on in {comp:?}");
+    }
+    s.execute("comp.setSwitch", json!({"comp": outer.0, "switch": "hideShy", "value": true})).unwrap();
+    assert_eq!(at(&s), o0, "Hide Shy Layers");
+    switch(&mut s, outer, nested, "audio", true);
+    switch(&mut s, outer, nested, "lock", false);
+    assert_eq!(at(&s), o0, "toggled back");
+    // Switches that change pixels still do.
+    switch(&mut s, inner, solid, "video", false);
+    let o1 = at(&s);
+    assert_ne!(o1, o0, "Video");
+    switch(&mut s, outer, nested, "audio", false);
+    assert_eq!(at(&s), o1, "a mute after a real edit keeps that edit's frames");
+    switch(&mut s, inner, solid, "video", true);
+    assert_ne!(at(&s), o1);
+}
+
+/// A cut or trim recaches only the frames of the layers it touched (#1641), and none are
+/// kept when the change reaches other layers (here a child of the trimmed layer).
+#[test]
+fn an_edit_keeps_the_frames_outside_the_layers_it_changed() {
+    use effectcraft_engine::Session;
+    use serde_json::json;
+    let mut s = Session::default();
+    let id = |v: serde_json::Value, k: &str| v[k].as_u64().unwrap();
+    let comp = ItemId(id(s.execute("comp.new", json!({"name": "Edit", "width": 8, "height": 8, "duration": 10})).unwrap(), "comp"));
+    let a = id(s.execute("layer.newSolid", json!({"comp": comp.0, "color": "#ff0000"})).unwrap(), "layer");
+    let b = id(s.execute("layer.newSolid", json!({"comp": comp.0, "color": "#00ff00"})).unwrap(), "layer");
+    s.execute("layer.timing", json!({"layers": [a], "in": 0, "out": 4})).unwrap();
+    s.execute("layer.timing", json!({"layers": [b], "in": 4, "out": 10})).unwrap();
+    let (fr, out) = s.project.comp(comp).map(|c| (c.frame_rate, c.layers.iter().find(|l| l.id.0 == a).unwrap().out_point)).unwrap();
+    let frames: Vec<i64> = (0..fr.frame_at(Tick::from_seconds_f64(10.0))).collect();
+    let f = Frames::default();
+    let cache_all = |s: &Session| {
+        let c = f.content_of(&s.project, s.revision, comp);
+        frames.iter().for_each(|&n| insert(&f, key(c, n, 0)));
+        c
+    };
+    let cached = |c: u64| frames.iter().filter(|&&n| f.is_cached(&key(c, n, 0))).copied().collect::<Vec<_>>();
+    let before = cache_all(&s);
+    s.execute("time.set", json!({"time": 2.0})).unwrap();
+    s.execute("edit.splitLayer", json!({"layers": [a]})).unwrap();
+    let after = f.content_of(&s.project, s.revision, comp);
+    assert_ne!(after, before);
+    let kept: Vec<i64> = (fr.frame_at(out) + 2..frames.len() as i64).collect();
+    assert_eq!(cached(after), kept, "the cut layer's frames (and one either side) render again; the rest stay");
+
+    s.execute("layer.setParent", json!({"layers": [b], "parent": a})).unwrap();
+    let parented = cache_all(&s);
+    s.execute("layer.timing", json!({"layers": [a], "out": 1})).unwrap();
+    assert_eq!(cached(f.content_of(&s.project, s.revision, comp)), Vec::<i64>::new(), "the trimmed layer's child moves everywhere");
+    assert_eq!(cached(parented).len(), frames.len(), "the earlier frames stay for undo");
+}
+
+/// Every frame an edit keeps renders as a fresh render of the edited project does: Solo
+/// hides the other layers at every frame, and a camera reaches the frames whose shutter
+/// samples it (#1641 review).
+#[test]
+fn the_frames_an_edit_keeps_match_a_fresh_render() {
+    use effectcraft_engine::Session;
+    use effectcraft_engine::render::NoFootage;
+    use serde_json::json;
+    // Cache every frame of `comp`, run `edit`, check the frames kept against fresh renders.
+    fn kept(s: &mut Session, comp: ItemId, edit: serde_json::Value) -> Vec<i64> {
+        let (fr, n) = s.project.comp(comp).map(|c| (c.frame_rate, c.frame_rate.frame_at(c.duration))).unwrap();
+        let f = Frames::default();
+        let before = f.content_of(&s.project, s.revision, comp);
+        (0..n).for_each(|i| insert(&f, key(before, i, 0)));
+        let old = s.project.clone();
+        s.execute(edit["cmd"].as_str().unwrap(), edit["params"].clone()).unwrap();
+        let after = f.content_of(&s.project, s.revision, comp);
+        let kept: Vec<i64> = (0..n).filter(|&i| f.is_cached(&key(after, i, 0))).collect();
+        let render = |p, i| Renderer::new(p, &NoFootage, RenderOpts::default()).comp_frame(comp, fr.tick_of(i));
+        for &i in &kept {
+            assert_eq!(render(&old, i), render(&s.project, i), "kept frame {i} draws other pixels now");
+        }
+        kept
+    }
+    let id = |v: serde_json::Value, k: &str| v[k].as_u64().unwrap();
+    let mut s = Session::default();
+
+    // Solo on a 2–3 s layer hides the 10 s underlay everywhere; turning it off shows it again.
+    let comp = ItemId(id(s.execute("comp.new", json!({"name": "Solo", "width": 8, "height": 8, "duration": 10})).unwrap(), "comp"));
+    s.execute("layer.newSolid", json!({"comp": comp.0, "color": "#ff0000"})).unwrap();
+    let short = id(s.execute("layer.newSolid", json!({"comp": comp.0, "color": "#00ff00"})).unwrap(), "layer");
+    s.execute("layer.timing", json!({"layers": [short], "in": 2, "out": 3})).unwrap();
+    let solo = |on: bool| json!({"cmd": "layer.setSwitch", "params": {"layers": [short], "switch": "solo", "value": on}});
+    assert_eq!(kept(&mut s, comp, solo(true)), Vec::<i64>::new());
+    assert_eq!(kept(&mut s, comp, solo(false)), Vec::<i64>::new());
+
+    // A 2–3 s camera over a 4 s motion-blurred 3D layer, shutter 720° at phase 360°: a frame
+    // samples 1 to 3 frames ahead, so moving the camera reaches the 3 frames before it.
+    let comp = ItemId(id(
+        s.execute("comp.new", json!({"name": "Cam", "width": 16, "height": 16, "duration": 4, "frameRate": 30, "shutterAngle": 720, "shutterPhase": 360}))
+            .unwrap(),
+        "comp",
+    ));
+    let plane = id(s.execute("layer.newSolid", json!({"comp": comp.0, "color": "#ff0000"})).unwrap(), "layer");
+    for sw in ["threeD", "motionBlur"] {
+        s.execute("layer.setSwitch", json!({"layers": [plane], "switch": sw, "value": true})).unwrap();
+    }
+    let cam = id(s.execute("layer.newCamera", json!({"comp": comp.0})).unwrap(), "layer");
+    s.execute("layer.timing", json!({"layers": [cam], "in": 2, "out": 3})).unwrap();
+    let moved = kept(&mut s, comp, json!({"cmd": "prop.set", "params": {"comp": comp.0, "layer": cam, "path": "transform/position", "value": [40, 8, -30]}}));
+    assert!(moved.contains(&0) && moved.contains(&100), "frames far from the camera stay: {moved:?}");
+    assert!(!(56..=91).any(|f| moved.contains(&f)), "frames whose shutter samples the camera render again: {moved:?}");
+}
+
+#[test]
+fn short_solid_additions_and_removals_keep_unaffected_frames() {
+    use effectcraft_engine::Session;
+    use serde_json::json;
+    let mut s = Session::default();
+    let comp = ItemId(s.execute("comp.new", json!({"width": 8, "height": 8, "frameRate": 30, "duration": 20})).unwrap()["comp"].as_u64().unwrap());
+    s.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap();
+    let f = Frames::default();
+    let cache_all = |s: &Session| {
+        let content = f.content_of(&s.project, s.revision, comp);
+        (0..600).for_each(|n| insert(&f, key(content, n, 0)));
+    };
+    let cached = |s: &Session| f.cached_frames(&key(f.content_of(&s.project, s.revision, comp), 0, 0));
+    // 2–3 s, a quarter frame of the default shutter and a frame of rounding either side.
+    let kept: Vec<i64> = (0..=57).chain(92..600).collect();
+    cache_all(&s);
+    let solid = s.execute("layer.newSolid", json!({"color": "#00ff00"})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("layer.timing", json!({"layers": [solid], "in": 2, "out": 3})).unwrap();
+    assert_eq!(cached(&s), kept, "adding a source invalidates only frames 58..=91");
+    cache_all(&s);
+    s.execute("edit.undo", json!({})).unwrap();
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(cached(&s), (0..600).collect::<Vec<_>>(), "undoing the addition restores every frame");
+    s.execute("edit.redo", json!({})).unwrap();
+    s.execute("edit.redo", json!({})).unwrap();
+    assert_eq!(cached(&s), (0..600).collect::<Vec<_>>(), "redoing the addition restores every frame");
+    s.execute("edit.clear", json!({"layers": [solid]})).unwrap();
+    assert_eq!(cached(&s), kept, "removing its layer invalidates the same span");
+}
+
+#[test]
+fn adding_a_source_does_not_hide_changes_to_existing_dependencies() {
+    use effectcraft_engine::Session;
+    use serde_json::json;
+    for (command, params) in [
+        ("layer.settings", json!({"comp": "Outer", "layer": "Underlay", "color": "#0000ff"})),
+        ("prop.set", json!({"comp": "Inner", "layer": "Inner solid", "path": "transform/opacity", "value": 40})),
+    ] {
+        let mut s = Session::default();
+        let comp = ItemId(
+            s.execute("comp.new", json!({"name": "Outer", "width": 8, "height": 8, "frameRate": 30, "duration": 20})).unwrap()["comp"].as_u64().unwrap(),
+        );
+        s.execute("layer.newSolid", json!({"name": "Underlay", "color": "#ff0000"})).unwrap();
+        s.execute("comp.new", json!({"name": "Inner", "width": 8, "height": 8, "duration": 20})).unwrap();
+        s.execute("layer.newSolid", json!({"name": "Inner solid", "color": "#00ff00"})).unwrap();
+        s.execute("comp.open", json!({"comp": "Outer"})).unwrap();
+        s.execute("layer.addItem", json!({"item": "Inner"})).unwrap();
+        let f = Frames::default();
+        let before = f.content_of(&s.project, s.revision, comp);
+        (0..600).for_each(|n| insert(&f, key(before, n, 0)));
+        s.execute(command, params).unwrap();
+        let solid = s.execute("layer.newSolid", json!({"color": "#ffffff"})).unwrap()["layer"].as_u64().unwrap();
+        s.execute("layer.timing", json!({"layers": [solid], "in": 2, "out": 3})).unwrap();
+        let after = f.content_of(&s.project, s.revision, comp);
+        assert!(f.cached_frames(&key(after, 0, 0)).is_empty(), "{command} changes pixels outside the added layer");
+    }
+}
+
+#[test]
+fn markers_keep_the_frames() {
+    use effectcraft_engine::Session;
+    use serde_json::json;
+    let mut s = Session::default();
+    let id = |v: serde_json::Value, k: &str| v[k].as_u64().unwrap();
+    let outer = ItemId(id(s.execute("comp.new", json!({"name": "Outer", "width": 8, "height": 8, "duration": 1})).unwrap(), "comp"));
+    let solid = id(s.execute("layer.newSolid", json!({"comp": outer.0, "color": "#ff0000"})).unwrap(), "layer");
+    let f = Frames::default();
+    let at = |s: &Session| f.content_of(&s.project, s.revision, outer);
+    let o0 = at(&s);
+    s.execute("layer.addMarker", json!({"comp": outer.0, "layers": [solid], "time": 0.5, "comment": "beat"})).unwrap();
+    assert_eq!(at(&s), o0, "a marker changes no pixels, so it keeps the frames");
+}
+
+#[test]
+fn markers_count_when_an_expression_can_read_them() {
+    use effectcraft_engine::Session;
+    use serde_json::json;
+    let mut s = Session::default();
+    let id = |v: serde_json::Value, k: &str| v[k].as_u64().unwrap();
+    let outer = ItemId(id(s.execute("comp.new", json!({"name": "Outer", "width": 8, "height": 8, "duration": 1})).unwrap(), "comp"));
+    let solid = id(s.execute("layer.newSolid", json!({"comp": outer.0, "color": "#ff0000"})).unwrap(), "layer");
+    s.execute("prop.setExpression", json!({"comp": outer.0, "layer": solid, "path": "transform/opacity", "expression": "1"})).unwrap();
+    let f = Frames::default();
+    let at = |s: &Session| f.content_of(&s.project, s.revision, outer);
+    let o0 = at(&s);
+    s.execute("layer.addMarker", json!({"comp": outer.0, "layers": [solid], "time": 0.5, "comment": "beat"})).unwrap();
+    assert_ne!(at(&s), o0, "an expression can read the marker, so the frames change");
+}
diff --git a/crates/ui-egui/src/header.rs b/crates/ui-egui/src/header.rs
index 861d6fd91..3eee89453 100644
--- a/crates/ui-egui/src/header.rs
+++ b/crates/ui-egui/src/header.rs
@@ -25,11 +25,19 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     p.rect_filled(rect, 0.0, t.header_bg);
     p.line_segment([rect.left_bottom(), rect.right_bottom()], Stroke::new(1.0, t.app_bg));
     let cy = rect.center().y;
-    let mut x = rect.min.x + if app.integrated_titlebar && !app.ui.show_menu_bar { 80.0 } else { 10.0 };
+    let x = rect.min.x + if app.integrated_titlebar && !app.ui.show_menu_bar { 80.0 } else { 10.0 };
+    let x = brand_and_home(app, ui, &p, x, cy);
+    let x = tool_slots(app, ui, &p, x, cy);
+    let x = tool_options_bar(app, ui, &p, x + 10.0, cy);
+    let x = snapping_toggle(app, ui, &p, x, cy);
+    right_side(app, ui, &p, rect, x, cy);
+}
 
-    // Brand mark.
+/// The brand mark (About) and the Home button; returns the x after them.
+fn brand_and_home(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, mut x: f32, cy: f32) -> f32 {
+    let t = app.tokens;
     let brand = Rect::from_min_size(pos2(x, cy - 12.0), vec2(24.0, 24.0));
-    paint_logo(&p, brand);
+    paint_logo(p, brand);
     let bresp = ui.interact(brand, egui::Id::unique("brand"), Sense::click());
     app.auto.add_response("header.about", &bresp, "About EffectCraft");
     widgets::focus_outline(ui, &bresp, &t);
@@ -38,7 +46,6 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
     x += 32.0;
 
-    // Home.
     let home = Rect::from_min_size(pos2(x, cy - 13.0), vec2(26.0, 26.0));
     let home_response = widgets::icon_button(ui, home, Icon::Home, app.ui.start_screen, &t, egui::Id::unique("tool-home")).on_hover_text(tr("Home"));
     app.auto.add_response("header.home", &home_response, "Home");
@@ -47,78 +54,19 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
     x += 30.0;
     p.line_segment([pos2(x, cy - 10.0), pos2(x, cy + 10.0)], Stroke::new(1.0, t.separator));
-    x += 6.0;
+    x + 6.0
+}
 
-    // Tool slots (with group separators after camera tools and pan-behind).
+/// The tool slots (with group separators after camera tools and pan-behind); returns the x after them.
+fn tool_slots(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, mut x: f32, cy: f32) -> f32 {
+    let t = app.tokens;
     let held_id = egui::Id::unique("tool-slot-held");
     if ui.input(|i| i.pointer.any_pressed()) {
         ui.data_mut(|d| d.remove::<egui::Id>(held_id));
     }
     for (si, slot) in Tool::SLOTS.iter().enumerate() {
-        let cur = app.ui.slot_tools.get(si).copied().unwrap_or(slot[0]);
         let r = Rect::from_min_size(pos2(x, cy - 13.0), vec2(26.0, 26.0));
-        let active = slot.contains(&app.ui.tool);
-        let id = egui::Id::unique(("tool-slot", si));
-        let resp = widgets::icon_button(ui, r, cur.icon(), active, &t, id);
-        if slot.len() > 1 {
-            // Flyout corner triangle.
-            p.add(egui::Shape::convex_polygon(
-                vec![pos2(r.max.x - 2.0, r.max.y - 6.0), pos2(r.max.x - 2.0, r.max.y - 2.0), pos2(r.max.x - 6.0, r.max.y - 2.0)],
-                if active { Color32::WHITE } else { t.text_dim },
-                Stroke::NONE,
-            ));
-        }
-        app.auto.add_response(&format!("tools.{cur:?}"), &resp, cur.label());
-        let tip = match cur.shortcut() {
-            Some(s) => format!("{} ({})", cur.label(), crate::menus::shortcut_text(s)),
-            None => cur.label().to_string(),
-        };
-        let resp = resp.on_hover_text(tip);
-        let held = ui.data(|d| d.get_temp::<egui::Id>(held_id)) == Some(id);
-        if resp.clicked() && !held {
-            app.ui.tool = cur;
-        }
-        // Ctrl+double-click Pan Behind: Center Anchor Point in Layer Content.
-        if cur == Tool::PanBehind
-            && resp.double_clicked()
-            && ui.input(|i| i.modifiers.command)
-            && let Err(e) = crate::menus::invoke(app, ui.ctx(), "layer.centerAnchor", json!({}))
-        {
-            app.ui.status = e;
-        }
-        if slot.len() > 1 {
-            let held_for = resp.is_pointer_button_down_on().then(|| ui.input(|i| i.pointer.press_start_time().map(|s| i.time - s))).flatten();
-            if let Some(seconds) = held_for
-                && seconds < 0.35
-            {
-                ui.ctx().request_repaint_after(std::time::Duration::from_secs_f64(0.35 - seconds));
-            }
-            let long_press = held_for.is_some_and(|seconds| seconds >= 0.35) && !held;
-            let command = if resp.secondary_clicked() || long_press {
-                if long_press {
-                    ui.data_mut(|d| d.insert_temp(held_id, id));
-                }
-                Some(egui::SetOpenCommand::Bool(true))
-            } else if resp.clicked() && !held {
-                Some(egui::SetOpenCommand::Bool(false))
-            } else {
-                None
-            };
-            let close_behavior = if held && resp.clicked() { egui::PopupCloseBehavior::IgnoreClicks } else { egui::PopupCloseBehavior::CloseOnClickOutside };
-            egui::Popup::menu(&resp).style(crate::widgets::menu_style).open_memory(command).close_behavior(close_behavior).show(|ui| {
-                for tool in slot.iter() {
-                    let row = ui.selectable_label(app.ui.tool == *tool, tool.label());
-                    app.auto.add(&format!("tools.select.{tool:?}"), row.rect, tool.label());
-                    if row.clicked() {
-                        app.ui.tool = *tool;
-                        if let Some(saved) = app.ui.slot_tools.get_mut(si) {
-                            *saved = *tool;
-                        }
-                        ui.close();
-                    }
-                }
-            });
-        }
+        tool_slot(app, ui, p, si, slot, r, held_id);
         x += 28.0;
         if matches!(si, 2 | 5 | 7 | 10 | 13) {
             x += 4.0;
@@ -126,17 +74,96 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             x += 6.0;
         }
     }
+    x
+}
 
-    // Tool options.
-    x += 10.0;
-    // Selected shape layers: the options show their paint and edit it (as in After Effects).
-    let shape_layers: Vec<u64> = app
-        .session
+/// One tool slot button in `r`: select on click, Ctrl+double-click Pan Behind, and the fly-out.
+fn tool_slot(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, si: usize, slot: &[Tool], r: Rect, held_id: egui::Id) {
+    let t = app.tokens;
+    let cur = app.ui.slot_tools.get(si).copied().unwrap_or(slot[0]);
+    let active = slot.contains(&app.ui.tool);
+    let id = egui::Id::unique(("tool-slot", si));
+    let resp = widgets::icon_button(ui, r, cur.icon(), active, &t, id);
+    if slot.len() > 1 {
+        // Flyout corner triangle.
+        p.add(egui::Shape::convex_polygon(
+            vec![pos2(r.max.x - 2.0, r.max.y - 6.0), pos2(r.max.x - 2.0, r.max.y - 2.0), pos2(r.max.x - 6.0, r.max.y - 2.0)],
+            if active { Color32::WHITE } else { t.text_dim },
+            Stroke::NONE,
+        ));
+    }
+    app.auto.add_response(&format!("tools.{cur:?}"), &resp, cur.label());
+    let tip = match cur.shortcut() {
+        Some(s) => format!("{} ({})", cur.label(), crate::menus::shortcut_text(s)),
+        None => cur.label().to_string(),
+    };
+    let resp = resp.on_hover_text(tip);
+    let held = ui.data(|d| d.get_temp::<egui::Id>(held_id)) == Some(id);
+    if resp.clicked() && !held {
+        app.ui.tool = cur;
+    }
+    // Ctrl+double-click Pan Behind: Center Anchor Point in Layer Content.
+    if cur == Tool::PanBehind
+        && resp.double_clicked()
+        && ui.input(|i| i.modifiers.command)
+        && let Err(e) = crate::menus::invoke(app, ui.ctx(), "layer.centerAnchor", json!({}))
+    {
+        app.ui.status = e;
+    }
+    if slot.len() > 1 {
+        slot_flyout(app, ui, si, slot, &resp, held_id);
+    }
+}
+
+/// The fly-out menu of a multi-tool slot: right-click or press-and-hold opens it.
+fn slot_flyout(app: &mut EffectcraftApp, ui: &mut egui::Ui, si: usize, slot: &[Tool], resp: &egui::Response, held_id: egui::Id) {
+    let id = resp.id;
+    let held = ui.data(|d| d.get_temp::<egui::Id>(held_id)) == Some(id);
+    let held_for = resp.is_pointer_button_down_on().then(|| ui.input(|i| i.pointer.press_start_time().map(|s| i.time - s))).flatten();
+    if let Some(seconds) = held_for
+        && seconds < 0.35
+    {
+        ui.ctx().request_repaint_after(std::time::Duration::from_secs_f64(0.35 - seconds));
+    }
+    let long_press = held_for.is_some_and(|seconds| seconds >= 0.35) && !held;
+    let command = if resp.secondary_clicked() || long_press {
+        if long_press {
+            ui.data_mut(|d| d.insert_temp(held_id, id));
+        }
+        Some(egui::SetOpenCommand::Bool(true))
+    } else if resp.clicked() && !held {
+        Some(egui::SetOpenCommand::Bool(false))
+    } else {
+        None
+    };
+    let close_behavior = if held && resp.clicked() { egui::PopupCloseBehavior::IgnoreClicks } else { egui::PopupCloseBehavior::CloseOnClickOutside };
+    egui::Popup::menu(resp).style(crate::widgets::menu_style).open_memory(command).close_behavior(close_behavior).show(|ui| {
+        for tool in slot.iter() {
+            let row = ui.selectable_label(app.ui.tool == *tool, tool.label());
+            app.auto.add(&format!("tools.select.{tool:?}"), row.rect, tool.label());
+            if row.clicked() {
+                app.ui.tool = *tool;
+                if let Some(saved) = app.ui.slot_tools.get_mut(si) {
+                    *saved = *tool;
+                }
+                ui.close();
+            }
+        }
+    });
+}
+
+/// The ids of the selected shape layers: the options show their paint and edit it.
+fn selected_shape_layers(app: &EffectcraftApp) -> Vec<u64> {
+    app.session
         .active_comp()
         .map(|c| {
             app.session.state.selected_layers.iter().filter(|id| c.layer(**id).is_some_and(|l| matches!(l.source, LayerSource::Shape))).map(|id| id.0).collect()
         })
-        .unwrap_or_default();
+        .unwrap_or_default()
+}
+
+/// Mirrors the first selected shape layer's paint into the shape tool (as in After Effects).
+fn sync_layer_paint(app: &mut EffectcraftApp, shape_layers: &[u64]) {
     let layer_paint = shape_layers.first().and_then(|id| app.session.active_comp()?.layer(LayerId(*id))).map(|l| {
         let lt = l.layer_time(app.session.time());
         (effectcraft_engine::commands::shape_stroke::first_paint(l, lt), effectcraft_engine::commands::shape_stroke::first_paint_kinds(l, lt))
@@ -154,6 +181,13 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
         tool.stroke_width = width.unwrap_or(0.0);
     }
+}
+
+/// Options for the active tool (shape creation, fill and stroke, puppet, roto); returns the x after them.
+fn tool_options_bar(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, mut x: f32, cy: f32) -> f32 {
+    // Selected shape layers: the options show their paint and edit it (as in After Effects).
+    let shape_layers = selected_shape_layers(app);
+    sync_layer_paint(app, &shape_layers);
     // One undo step per picker session or width drag: end the merge once both are done.
     let picking = ["fill", "stroke"].iter().any(|k| widgets::popup_is_open(ui, picker_id(k)));
     if !picking && !ui.input(|i| i.pointer.any_down()) && app.session.history.merge_key.as_deref().is_some_and(|k| k.starts_with("tool-")) {
@@ -167,14 +201,20 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     // Fill and Stroke, hidden while the tools draw masks.
     let masking = drawing && !shape_layers.is_empty() && app.session.state.shape_tool.creates_mask;
     if (drawing || !shape_layers.is_empty()) && !masking {
-        x = fill_stroke_options(app, ui, &p, &shape_layers, x, cy);
+        x = fill_stroke_options(app, ui, p, &shape_layers, x, cy);
     }
     if app.ui.tool.puppet_kind().is_some() {
-        x = puppet_options(app, ui, &p, x, cy);
+        x = puppet_options(app, ui, p, x, cy);
     }
     if app.ui.tool.roto_kind(false).is_some() {
-        x = roto_options(app, ui, &p, x, cy);
+        x = roto_options(app, ui, p, x, cy);
     }
+    x
+}
+
+/// The Snapping checkbox, its label and options menu; returns the x where it started.
+fn snapping_toggle(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, x: f32, cy: f32) -> f32 {
+    let t = app.tokens;
     let snap = Rect::from_min_size(pos2(x, cy - 10.0), vec2(20.0, 20.0));
     // The engine owns snapping (View ▸ Snapping); the checkbox mirrors it.
     app.ui.snapping = app.session.state.snapping;
@@ -185,9 +225,24 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     app.auto.add("header.snapping", snap, "Snapping");
     let label = p.text(pos2(snap.max.x + 4.0, cy), Align2::LEFT_CENTER, tr("Snapping"), Tokens::ui(12.0), t.text_dim);
     snapping_options(app, ui, Rect::from_min_size(pos2(label.max.x + 2.0, cy - 9.0), vec2(18.0, 18.0)));
+    x
+}
 
-    // Right side: community buttons, workspaces.
-    let mut rx = rect.max.x - 10.0;
+/// Right side: community buttons, appearance and workspaces; `left` is where the tools end.
+fn right_side(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, rect: Rect, left: f32, cy: f32) {
+    let t = app.tokens;
+    let rx = community_buttons(app, ui, p, rect.max.x - 10.0, cy);
+    let mut rx = appearance_button(app, ui, rx, cy);
+    rx -= 10.0;
+    p.line_segment([pos2(rx, cy - 10.0), pos2(rx, cy + 10.0)], Stroke::new(1.0, t.separator));
+    rx -= 10.0;
+    let rx = workspace_menu(app, ui, p, rx, cy);
+    workspace_tabs(app, ui, p, rx, left, cy);
+}
+
+/// The Discord pill and the GitHub and website buttons, right to left from `rx`; returns the new `rx`.
+fn community_buttons(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, mut rx: f32, cy: f32) -> f32 {
+    let t = app.tokens;
     // The pill fits its label (icon, gap, text) with even padding: it was a fixed 104 px with the
     // text at its left, which left a wide gap on the right (#581).
     let label = p.layout_no_wrap(tr("Discord").to_string(), Tokens::semibold(12.0), Color32::WHITE);
@@ -195,7 +250,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let dresp = ui.interact(discord, egui::Id::unique("hdr-discord"), Sense::click());
     let dc = Color32::from_rgb(0x58, 0x65, 0xf2);
     p.rect_filled(discord, 13.0, if dresp.hovered() { dc.gamma_multiply(1.2) } else { dc });
-    icons::paint(&p, Rect::from_center_size(pos2(discord.min.x + 17.0, cy), vec2(14.0, 14.0)), Icon::Chat, Color32::WHITE);
+    icons::paint(p, Rect::from_center_size(pos2(discord.min.x + 17.0, cy), vec2(14.0, 14.0)), Icon::Chat, Color32::WHITE);
     p.galley(pos2(discord.min.x + 30.0, cy - label.size().y / 2.0), label, Color32::WHITE);
     app.auto.add("header.discord", discord, "Join the ArtCraft Discord");
     if dresp.on_hover_text(tr("Join the ArtCraft community on Discord")).clicked() {
@@ -212,7 +267,13 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         app.auto.add(&format!("header.{}", &id[4..]), r, tip);
         rx = r.min.x - 4.0;
     }
-    // Appearance: Sync with System, Light, Dark (a monitor, sun or moon), one click to the next.
+    rx
+}
+
+/// Appearance: Sync with System, Light, Dark (a monitor, sun or moon), one click to the next;
+/// returns the new `rx`.
+fn appearance_button(app: &mut EffectcraftApp, ui: &mut egui::Ui, rx: f32, cy: f32) -> f32 {
+    let t = app.tokens;
     let (icon, mode) = match app.session.prefs.appearance.appearance_mode.as_str() {
         "auto" => (Icon::Monitor, tr("Sync with System")),
         "light" => (Icon::Sun, tr("Light")),
@@ -224,37 +285,41 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     if response.clicked() {
         app.cycle_appearance(ui.ctx());
     }
-    response.context_menu(|ui| {
-        let settings = ui.button(tr("Appearance Settings…"));
-        app.auto.add("header.appearanceSettings", settings.rect, "Appearance Settings…");
-        if settings.clicked() {
-            crate::panels::settings::open(app, "appearance");
-            ui.close();
-        }
-        let favorites = app.session.prefs.appearance.favorite_themes.clone();
-        for options in [effectcraft_engine::prefs::LIGHT_THEMES, effectcraft_engine::prefs::DARK_THEMES] {
-            let group: Vec<_> = options.iter().filter(|(_, id)| favorites.iter().any(|saved| saved == id)).collect();
-            if !group.is_empty() {
-                ui.separator();
-            }
-            for (label, id) in group {
-                let r = ui.selectable_label(app.ui.theme.name() == *id, tr(label));
-                app.auto.add(&format!("header.favoriteTheme.{id}"), r.rect, label);
-                if r.clicked() {
-                    if let Some(kind) = crate::theme::ThemeKind::from_name(id) {
-                        app.set_theme(ui.ctx(), kind);
-                    }
-                    ui.close();
-                }
-            }
-        }
-    });
+    response.context_menu(|ui| appearance_menu(app, ui));
     app.auto.add("header.appearance", r, &tip);
-    rx = r.min.x - 4.0;
-    rx -= 10.0;
-    p.line_segment([pos2(rx, cy - 10.0), pos2(rx, cy + 10.0)], Stroke::new(1.0, t.separator));
-    rx -= 10.0;
-    // Workspace tabs (right to left), with a » menu of all.
+    r.min.x - 4.0
+}
+
+/// The appearance button's context menu: settings and the favorite themes.
+fn appearance_menu(app: &mut EffectcraftApp, ui: &mut egui::Ui) {
+    let settings = ui.button(tr("Appearance Settings…"));
+    app.auto.add("header.appearanceSettings", settings.rect, "Appearance Settings…");
+    if settings.clicked() {
+        crate::panels::settings::open(app, "appearance");
+        ui.close();
+    }
+    let favorites = app.session.prefs.appearance.favorite_themes.clone();
+    for options in [effectcraft_engine::prefs::LIGHT_THEMES, effectcraft_engine::prefs::DARK_THEMES] {
+        let group: Vec<_> = options.iter().filter(|(_, id)| favorites.iter().any(|saved| saved == id)).collect();
+        if !group.is_empty() {
+            ui.separator();
+        }
+        for (label, id) in group {
+            let r = ui.selectable_label(app.ui.theme.name() == *id, tr(label));
+            app.auto.add(&format!("header.favoriteTheme.{id}"), r.rect, label);
+            if r.clicked() {
+                if let Some(kind) = crate::theme::ThemeKind::from_name(id) {
+                    app.set_theme(ui.ctx(), kind);
+                }
+                ui.close();
+            }
+        }
+    }
+}
+
+/// The » button with the menu of all workspaces; returns the new `rx`.
+fn workspace_menu(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, rx: f32, cy: f32) -> f32 {
+    let t = app.tokens;
     let more = Rect::from_min_max(pos2(rx - 20.0, cy - 11.0), pos2(rx, cy + 11.0));
     let mresp = ui.interact(more, egui::Id::unique("ws-more"), Sense::click());
     p.text(more.center(), Align2::CENTER_CENTER, "»", Tokens::ui(15.0), if mresp.hovered() { t.text } else { t.text_dim });
@@ -273,15 +338,19 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     ) {
         app.set_workspace(crate::dock::WORKSPACES[i]);
     }
-    rx = more.min.x - 6.0;
-    // After Effects 2026's workspace bar order (right to left here): Default, Review, Learn,
-    // Small Screen, Standard.
+    more.min.x - 6.0
+}
+
+/// Workspace tabs, right to left from `rx`, stopping 120 px right of `left`.
+/// After Effects 2026's order (right to left here): Default, Review, Learn, Small Screen, Standard.
+fn workspace_tabs(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, mut rx: f32, left: f32, cy: f32) {
+    let t = app.tokens;
     let shown = ["Standard", "Small Screen", "Learn", "Review", "Default"];
     for name in shown {
         let g = p.layout_no_wrap(crate::i18n::command_label("window.workspace", name).to_string(), Tokens::ui(12.0), t.text);
         let w = g.size().x + 16.0;
         let r = Rect::from_min_max(pos2(rx - w, cy - 13.0), pos2(rx, cy + 13.0));
-        if r.min.x < x + 120.0 {
+        if r.min.x < left + 120.0 {
             break;
         }
         let active = app.ui.workspace == name;
@@ -439,7 +508,14 @@ fn fill_stroke_options(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Pa
         x = sr.max.x + 12.0;
     }
     let width = app.session.state.shape_tool.stroke_width;
-    let (r, v, _) = widgets::hot_number_at(ui, pos2(x - 6.0, cy - 9.0), egui::Id::unique("tool-stroke-w"), width, 0.2, (0.0, 1000.0), 0, " px", &t);
+    let (r, v, _) = widgets::hot_number_at(
+        ui,
+        pos2(x - 6.0, cy - 9.0),
+        egui::Id::unique("tool-stroke-w"),
+        width,
+        &widgets::HotSpec { speed: 0.2, range: (0.0, 1000.0), decimals: 0, suffix: " px" },
+        &t,
+    );
     if let Some(v) = v {
         tool_options(app, json!({"strokeWidth": v}));
         paint(app, "strokeWidth", json!(v));
@@ -506,7 +582,14 @@ fn paint_options_popup(app: &mut EffectcraftApp, ui: &mut egui::Ui, shape_layers
             }
             app.auto.add(&format!("header.{key}Options.blend"), blend_rect, "Blend Mode");
             p.text(row(98.0), Align2::LEFT_CENTER, tr("Opacity:"), Tokens::ui(12.0), t.text_dim);
-            let (or, v, _) = widgets::hot_number_at(ui, row(89.0) + vec2(84.0, 0.0), id.with("opacity"), tp.opacity, 0.5, (0.0, 100.0), 0, "%", &t);
+            let (or, v, _) = widgets::hot_number_at(
+                ui,
+                row(89.0) + vec2(84.0, 0.0),
+                id.with("opacity"),
+                tp.opacity,
+                &widgets::HotSpec { speed: 0.5, range: (0.0, 100.0), decimals: 0, suffix: "%" },
+                &t,
+            );
             app.auto.add(&format!("header.{key}Options.opacity"), or, "Opacity");
             if let Some(v) = v {
                 let k_opacity = format!("{key}Opacity");
@@ -577,7 +660,14 @@ fn roto_options(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter,
     let label = tr("Diameter:");
     let lr = p.text(pos2(x, cy), Align2::LEFT_CENTER, label, Tokens::ui(12.0), t.text_dim);
     x = lr.max.x + 6.0;
-    let (r, nv, _) = widgets::hot_number_at(ui, pos2(x, cy - 9.0), egui::Id::unique(("roto-opt", key)), v, 0.5, (1.0, 5000.0), 0, " px", &t);
+    let (r, nv, _) = widgets::hot_number_at(
+        ui,
+        pos2(x, cy - 9.0),
+        egui::Id::unique(("roto-opt", key)),
+        v,
+        &widgets::HotSpec { speed: 0.5, range: (1.0, 5000.0), decimals: 0, suffix: " px" },
+        &t,
+    );
     app.auto.add("header.roto.diameter", r, label);
     if let Some(nv) = nv
         && let Err(e) = app.session.execute("roto.options", json!({key: nv}))
@@ -604,7 +694,14 @@ fn puppet_options(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter
     for (label, key, v, range) in [("Expansion:", "expansion", o.expansion, (-100.0, 200.0)), ("Density:", "density", o.density, (0.0, 100.0))] {
         p.text(pos2(x, cy), Align2::LEFT_CENTER, label, Tokens::ui(12.0), t.text_dim);
         x += if key == "expansion" { 64.0 } else { 52.0 };
-        let (r, nv, _) = widgets::hot_number_at(ui, pos2(x, cy - 9.0), egui::Id::unique(("puppet-opt", key)), v, 0.2, range, 0, "", &t);
+        let (r, nv, _) = widgets::hot_number_at(
+            ui,
+            pos2(x, cy - 9.0),
+            egui::Id::unique(("puppet-opt", key)),
+            v,
+            &widgets::HotSpec { speed: 0.2, range, decimals: 0, suffix: "" },
+            &t,
+        );
         app.auto.add(&format!("header.puppet.{key}"), r, label);
         if let Some(nv) = nv {
             let _ = app.session.execute("puppet.mesh", json!({key: nv, "merge": format!("puppet-opt-{key}")}));
diff --git a/crates/ui-egui/src/hooks.rs b/crates/ui-egui/src/hooks.rs
new file mode 100644
index 000000000..8d7dcb704
--- /dev/null
+++ b/crates/ui-egui/src/hooks.rs
@@ -0,0 +1,83 @@
+use super::*;
+
+/// The desktop's light or dark appearance where egui cannot see it (Wayland compositors that send
+/// winit no theme). `None` = the host does not know.
+pub type SystemThemeFn = Box<dyn Fn(&egui::Context) -> Option<egui::Theme>>;
+
+/// A file dialog a host shows without blocking the frame ([`Hooks::file_dialog_async`]).
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum FileDialog {
+    /// Files to open or import with these extensions; several when `many`.
+    Open { exts: Vec<String>, many: bool },
+    /// An EffectCraft project to open.
+    OpenProject,
+    /// A folder.
+    Folder,
+    /// Where to save `default` (a file name or path) with extension `ext` (empty: no filter);
+    /// `project`: the project save dialog, given the file name.
+    Save { default: String, ext: String, project: bool },
+}
+
+impl FileDialog {
+    /// The save dialog for `default`, as [`Hooks::save_dialog`] picks it.
+    pub fn save(default: &str) -> Self {
+        let ext = std::path::Path::new(default).extension().map(|e| e.to_string_lossy().to_string()).unwrap_or_default();
+        Self::Save { default: default.to_string(), project: ext.eq_ignore_ascii_case("ecproj"), ext }
+    }
+}
+
+/// Called with the paths a [`FileDialog`] picked (empty: cancelled), from any thread.
+pub type DialogDone = Box<dyn FnOnce(Vec<String>) + Send>;
+
+/// Host hooks provided by the native app (file pickers etc.).
+#[derive(Default)]
+pub struct Hooks {
+    /// The system appearance for Settings ▸ Appearance ▸ Sync with System (the desktop app reads
+    /// the Linux desktop portal); without it, what egui reports.
+    pub system_theme: Option<SystemThemeFn>,
+    pub pick_files: Option<Box<dyn Fn(&[&str]) -> Vec<String>>>,
+    pub pick_save: Option<Box<dyn Fn(&str) -> Option<String>>>,
+    pub pick_open_project: Option<Box<dyn Fn() -> Option<String>>>,
+    /// Opens the audio output for preview playback (the desktop app uses cpal).
+    pub audio_device: Option<audio::AudioDeviceFactory>,
+    /// Lists audio output devices (Settings ▸ Audio).
+    pub audio_devices: Option<Box<dyn Fn() -> Vec<String>>>,
+    /// Picks a folder (Settings paths).
+    pub pick_folder: Option<Box<dyn Fn() -> Option<String>>>,
+    /// Save dialog for other file kinds: (default name or path, extension; empty: no filter). A
+    /// default path opens the dialog in its folder.
+    pub pick_save_file: Option<Box<dyn Fn(&str, &str) -> Option<String>>>,
+    /// The system clipboard's text (native menu Edit ▸ Paste into a text field).
+    pub clipboard_text: Option<Box<dyn Fn() -> Option<String>>>,
+    /// Application actions the OS performs (`app.hide`, `app.hideOthers`, `app.showAll` on
+    /// macOS). Returns false when the host doesn't handle the id.
+    pub app_action: Option<Box<dyn Fn(&str) -> bool>>,
+    /// Shows a command's file dialog without blocking the frame and calls `done` with the
+    /// answer (the host then asks for a repaint). Used in place of the blocking pickers above for
+    /// the commands' dialogs (File ▸ Import, Open, Save As…) where blocking the frame is unsafe or
+    /// leaves the window unresponsive: on macOS a nested modal event loop there aborted the app on
+    /// a drag over the window (#511), and on Linux a blocking desktop-portal dialog never pumps
+    /// events, so the compositor marks the window as not responding (#1275).
+    pub file_dialog_async: Option<Box<dyn Fn(FileDialog, DialogDone)>>,
+    /// Tells the user the graphics device was lost and the window is closing, once. `saved` is
+    /// the auto-save of unsaved changes (`None`: nothing was unsaved), its path or why it failed.
+    pub device_lost: Option<Box<dyn Fn(Option<Result<String, String>>)>>,
+}
+
+impl Hooks {
+    /// The host's save dialog for `default` (a file name or path), offering its extension: the
+    /// project dialog for project files, else [`Hooks::pick_save_file`]. The project dialog is
+    /// the fallback for hosts without that (the web, whose dialog only names the file): on macOS
+    /// a dialog filtered to projects appends `.ecproj` to any other name (#293). `None` when the
+    /// host has no save dialog; `Some(None)` when it was cancelled.
+    pub fn save_dialog(&self, default: &str) -> Option<Option<String>> {
+        let path = std::path::Path::new(default);
+        let ext = path.extension().map(|e| e.to_string_lossy().to_string()).unwrap_or_default();
+        match (&self.pick_save_file, &self.pick_save) {
+            (Some(pick), _) if !ext.eq_ignore_ascii_case("ecproj") => Some(pick(default, &ext)),
+            (_, Some(pick)) => Some(pick(&path.file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_default())),
+            (Some(pick), None) => Some(pick(default, &ext)),
+            (None, None) => None,
+        }
+    }
+}
diff --git a/crates/ui-egui/src/i18n.rs b/crates/ui-egui/src/i18n.rs
index ccd3059fa..611a226ee 100644
--- a/crates/ui-egui/src/i18n.rs
+++ b/crates/ui-egui/src/i18n.rs
@@ -469,6 +469,7 @@ const SIMPLIFIED_CHINESE: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "安装脚本文件..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "安装 ScriptUI 面板..."),
     ("file.runScript", "Run Script File...", "运行脚本文件..."),
+    ("", "Recent Script Files", "最近的脚本文件"),
     ("", "Create Proxy", "创建代理"),
     ("file.createProxy", "Still...", "静止图像..."),
     ("file.createProxy", "Movie...", "影片..."),
@@ -1104,6 +1105,7 @@ const TRADITIONAL_CHINESE: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "安裝指令碼檔案..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "安裝 ScriptUI 面板..."),
     ("file.runScript", "Run Script File...", "執行指令碼檔案..."),
+    ("", "Recent Script Files", "最近使用的指令碼檔案"),
     ("", "Create Proxy", "建立代理"),
     ("file.createProxy", "Still...", "靜態影像..."),
     ("file.createProxy", "Movie...", "影片..."),
@@ -1736,6 +1738,7 @@ const JAPANESE: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "スクリプトファイルをインストール..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "ScriptUIパネルをインストール..."),
     ("file.runScript", "Run Script File...", "スクリプトファイルを実行..."),
+    ("", "Recent Script Files", "最近使用したスクリプトファイル"),
     ("", "Create Proxy", "プロキシを作成"),
     ("file.createProxy", "Still...", "静止画..."),
     ("file.createProxy", "Movie...", "ムービー..."),
@@ -2371,6 +2374,7 @@ const UKRAINIAN: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "Встановити файл скрипту..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "Встановити панель ScriptUI..."),
     ("file.runScript", "Run Script File...", "Виконати файл скрипту..."),
+    ("", "Recent Script Files", "Нещодавні файли скриптів"),
     ("", "Create Proxy", "Створити проксі"),
     ("file.createProxy", "Still...", "Зображення..."),
     ("file.createProxy", "Movie...", "Відео..."),
@@ -3007,6 +3011,7 @@ const SPANISH: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "Instalar archivo de script..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "Instalar panel de ScriptUI..."),
     ("file.runScript", "Run Script File...", "Ejecutar archivo de script..."),
+    ("", "Recent Script Files", "Archivos de script recientes"),
     ("", "Create Proxy", "Crear proxy"),
     ("file.createProxy", "Still...", "Imagen fija..."),
     ("file.createProxy", "Movie...", "Película..."),
@@ -3641,6 +3646,7 @@ const PORTUGUESE: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "Instalar arquivo de script..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "Instalar painel ScriptUI..."),
     ("file.runScript", "Run Script File...", "Executar arquivo de script..."),
+    ("", "Recent Script Files", "Arquivos de script recentes"),
     ("", "Create Proxy", "Criar proxy"),
     ("file.createProxy", "Still...", "Imagem fixa..."),
     ("file.createProxy", "Movie...", "Filme..."),
@@ -4283,6 +4289,7 @@ const RUSSIAN: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "Установить файл скрипта..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "Установить панель ScriptUI..."),
     ("file.runScript", "Run Script File...", "Выполнить файл скрипта..."),
+    ("", "Recent Script Files", "Недавние файлы скриптов"),
     ("", "Create Proxy", "Создать суррогат"),
     ("file.createProxy", "Still...", "Стоп-кадр..."),
     ("file.createProxy", "Movie...", "Видео..."),
@@ -4917,6 +4924,7 @@ const FRENCH: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "Installer un fichier de script..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "Installer un panneau ScriptUI..."),
     ("file.runScript", "Run Script File...", "Exécuter un fichier de script..."),
+    ("", "Recent Script Files", "Fichiers de script récents"),
     ("", "Create Proxy", "Créer un proxy"),
     ("file.createProxy", "Still...", "Image fixe..."),
     ("file.createProxy", "Movie...", "Vidéo..."),
@@ -5551,6 +5559,7 @@ const GERMAN: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "Skriptdatei installieren..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "ScriptUI-Bedienfeld installieren..."),
     ("file.runScript", "Run Script File...", "Skriptdatei ausführen..."),
+    ("", "Recent Script Files", "Zuletzt verwendete Skriptdateien"),
     ("", "Create Proxy", "Proxy erstellen"),
     ("file.createProxy", "Still...", "Standbild..."),
     ("file.createProxy", "Movie...", "Film..."),
@@ -6185,6 +6194,7 @@ const CZECH: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "Nainstalovat soubor skriptu..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "Nainstalovat panel ScriptUI..."),
     ("file.runScript", "Run Script File...", "Spustit soubor skriptu..."),
+    ("", "Recent Script Files", "Nedávné soubory skriptů"),
     ("", "Create Proxy", "Vytvořit zástupný soubor"),
     ("file.createProxy", "Still...", "Statický snímek..."),
     ("file.createProxy", "Movie...", "Video..."),
@@ -6816,6 +6826,7 @@ const GEORGIAN: &[(&str, &str, &str)] = &[
     ("file.installScript", "Install Script File...", "სკრიპტის ფაილის დაყენება..."),
     ("file.installScriptUIPanel", "Install ScriptUI Panel...", "ScriptUI პანელის დაყენება..."),
     ("file.runScript", "Run Script File...", "სკრიპტის ფაილის გაშვება..."),
+    ("", "Recent Script Files", "ბოლო სკრიპტის ფაილები"),
     ("", "Create Proxy", "პროქსის შექმნა"),
     ("file.createProxy", "Still...", "სტატიკური კადრი..."),
     ("file.createProxy", "Movie...", "ვიდეო..."),
diff --git a/crates/ui-egui/src/i18n/ui.rs b/crates/ui-egui/src/i18n/ui.rs
index 1b75ff3ee..46493296b 100644
--- a/crates/ui-egui/src/i18n/ui.rs
+++ b/crates/ui-egui/src/i18n/ui.rs
@@ -5433,7 +5433,12 @@ mod tests {
         ("dock.rs", include_str!("../dock.rs")),
         ("dock_ui.rs", include_str!("../dock_ui.rs")),
         ("header.rs", include_str!("../header.rs")),
-        ("menus.rs", include_str!("../menus.rs")),
+        ("menus/bar.rs", include_str!("../menus/bar.rs")),
+        ("menus/commands.rs", include_str!("../menus/commands.rs")),
+        ("menus/entries.rs", include_str!("../menus/entries.rs")),
+        ("menus/frontend.rs", include_str!("../menus/frontend.rs")),
+        ("menus/invoke.rs", include_str!("../menus/invoke.rs")),
+        ("menus/shortcuts.rs", include_str!("../menus/shortcuts.rs")),
         ("prefs_live.rs", include_str!("../prefs_live.rs")),
         ("widgets.rs", include_str!("../widgets.rs")),
         ("panels/anim_tools.rs", include_str!("../panels/anim_tools.rs")),
@@ -5444,7 +5449,11 @@ mod tests {
         ("panels/gradient_editor.rs", include_str!("../panels/gradient_editor.rs")),
         ("panels/dialogs.rs", include_str!("../panels/dialogs.rs")),
         ("panels/dialogs_3d.rs", include_str!("../panels/dialogs_3d.rs")),
-        ("panels/effect_controls.rs", include_str!("../panels/effect_controls.rs")),
+        ("panels/effect_controls/common.rs", include_str!("../panels/effect_controls/common.rs")),
+        ("panels/effect_controls/editors.rs", include_str!("../panels/effect_controls/editors.rs")),
+        ("panels/effect_controls/panel.rs", include_str!("../panels/effect_controls/panel.rs")),
+        ("panels/effect_controls/rows.rs", include_str!("../panels/effect_controls/rows.rs")),
+        ("panels/effect_controls/viewer.rs", include_str!("../panels/effect_controls/viewer.rs")),
         ("panels/effects_presets.rs", include_str!("../panels/effects_presets.rs")),
         ("panels/essential.rs", include_str!("../panels/essential.rs")),
         ("panels/expr_bar.rs", include_str!("../panels/expr_bar.rs")),
@@ -5462,7 +5471,7 @@ mod tests {
         ("panels/markers_ui.rs", include_str!("../panels/markers_ui.rs")),
         ("panels/media_panels.rs", include_str!("../panels/media_panels.rs")),
         ("panels/misc.rs", include_str!("../panels/misc.rs")),
-        ("panels/mod.rs", include_str!("../panels/mod.rs")),
+        ("panels.rs", include_str!("../panels.rs")),
         ("panels/paint_panels.rs", include_str!("../panels/paint_panels.rs")),
         ("panels/path_vr_panels.rs", include_str!("../panels/path_vr_panels.rs")),
         ("panels/precomp.rs", include_str!("../panels/precomp.rs")),
@@ -5482,13 +5491,20 @@ mod tests {
         ("panels/tracker.rs", include_str!("../panels/tracker.rs")),
         ("panels/unsaved.rs", include_str!("../panels/unsaved.rs")),
         ("panels/viewer.rs", include_str!("../panels/viewer.rs")),
+        ("panels/viewer/frame.rs", include_str!("../panels/viewer/frame.rs")),
+        ("panels/viewer/geometry.rs", include_str!("../panels/viewer/geometry.rs")),
+        ("panels/viewer/gesture.rs", include_str!("../panels/viewer/gesture.rs")),
+        ("panels/viewer/shapes.rs", include_str!("../panels/viewer/shapes.rs")),
+        ("panels/viewer/tools.rs", include_str!("../panels/viewer/tools.rs")),
+        ("panels/viewer/view.rs", include_str!("../panels/viewer/view.rs")),
         ("panels/viewer_tools.rs", include_str!("../panels/viewer_tools.rs")),
         ("panels/viewers.rs", include_str!("../panels/viewers.rs")),
         // Text the interface draws but does not own: the settings pages and the viewer's channel
         // and Fast Previews lists come from the engine as data, so their source strings live here.
-        ("engine settings pages", include_str!("../../../engine/src/prefs.rs")),
+        ("engine settings pages", include_str!("../../../engine/src/settings/prefs/dialog.rs")),
+        ("engine settings choices", include_str!("../../../engine/src/settings/prefs/choices.rs")),
         ("engine viewer channels", include_str!("../../../engine/src/viewer.rs")),
-        ("engine viewer commands", include_str!("../../../engine/src/commands/viewer_cmds.rs")),
+        ("engine viewer commands", include_str!("../../../engine/src/cmd/viewer_cmds.rs")),
     ];
 
     fn catalogs() -> Vec<(&'static str, &'static str)> {
diff --git a/crates/ui-egui/src/lib.rs b/crates/ui-egui/src/lib.rs
index 8e9c69fbf..fcbfd49bf 100644
--- a/crates/ui-egui/src/lib.rs
+++ b/crates/ui-egui/src/lib.rs
@@ -47,75 +47,15 @@ use serde_json::json;
 use state::UiState;
 use theme::Tokens;
 
-/// How long a screenshot request waits for a frame, from admission (app clock seconds).
-const SCREENSHOT_TIMEOUT_S: f64 = 8.0;
-/// Seconds between a screenshot's admission and the earliest capture: the UI settles first.
-const SCREENSHOT_SETTLE_S: f64 = 0.35;
-/// Final (non-discarded) UI passes a screenshot waits for after admission before it is issued.
-const SCREENSHOT_SETTLE_PASSES: u64 = 3;
-/// Geometry changes a queued screenshot may retry before it reports an error.
-const SCREENSHOT_MAX_RETRIES: u32 = 4;
-/// Outstanding screenshot requests (queued or waiting for their pixels).
-const MAX_PENDING_SHOTS: usize = 4;
-/// One capture's pixels: 128 MiB.
-const MAX_SHOT_BYTES: usize = 128 * 1024 * 1024;
-/// Every pending capture's reserved pixels together: 256 MiB.
-const MAX_SHOT_TOTAL_BYTES: usize = 256 * 1024 * 1024;
-/// Seconds without a project change before paused prefetch resumes (see
-/// [`EffectcraftApp::editing`]).
-const EDIT_QUIET: f64 = 0.3;
+mod app;
+mod clock;
+mod hooks;
 
-/// The application's monotonic clock, in seconds.
-///
-/// Neither `ctx.input(|i| i.time)` nor `RawInput::time` is valid in a logic-only tick:
-/// `Context::run_logic` copies only the viewport information, so both are the previous full
-/// pass's values. Playback, auto-save, screenshot deadlines and the control channel measure time
-/// with this clock instead. Native and web use the same [`web_time::Instant`] source; tests
-/// inject [`AppClock::manual`] and advance it.
-#[derive(Clone, Debug)]
-pub struct AppClock {
-    origin: web_time::Instant,
-    manual: Option<f64>,
-}
-
-impl AppClock {
-    /// The host's monotonic clock.
-    pub fn real() -> Self {
-        Self { origin: web_time::Instant::now(), manual: None }
-    }
-
-    /// A clock tests advance explicitly with [`AppClock::advance`].
-    pub fn manual() -> Self {
-        Self { origin: web_time::Instant::now(), manual: Some(0.0) }
-    }
-
-    /// Seconds since the clock started (monotonic on native and in the browser).
-    pub fn now(&self) -> f64 {
-        match self.manual {
-            Some(t) => t,
-            None => self.origin.elapsed().as_secs_f64(),
-        }
-    }
-
-    /// Move a manual clock forward; a real clock ignores this.
-    pub fn advance(&mut self, seconds: f64) {
-        if let Some(t) = &mut self.manual {
-            *t = (*t + seconds.max(0.0)).max(0.0);
-        }
-    }
-
-    /// Whether the clock is test-driven.
-    pub fn is_manual(&self) -> bool {
-        self.manual.is_some()
-    }
-}
-
-impl Default for AppClock {
-    /// The real monotonic clock (`Self::real()`).
-    fn default() -> Self {
-        Self::real()
-    }
-}
+#[cfg(test)]
+use app::{MAX_PENDING_SHOTS, SCREENSHOT_SETTLE_PASSES, SCREENSHOT_SETTLE_S, SCREENSHOT_TIMEOUT_S};
+pub use clock::AppClock;
+pub use hooks::{DialogDone, FileDialog, Hooks, SystemThemeFn};
+pub use state::ShotTarget;
 
 /// The root surface geometry of the last completed (non-discarded) UI pass.
 ///
@@ -129,39 +69,6 @@ pub struct DrawGeometry {
     pub epoch: u64,
 }
 
-/// Whether a captured image's dimensions match `rect` at `ppp`.
-///
-/// The surface may be smaller than requested when the adapter-limit fit (fork E2) applies, but a
-/// different aspect ratio means the pixels came from another layout than the one issued.
-fn shot_image_matches(image: &egui::ColorImage, rect: egui::Rect, ppp: f32) -> bool {
-    let [w, h] = image.size;
-    if w == 0 || h == 0 || !ppp.is_finite() || ppp <= 0.0 {
-        return false;
-    }
-    let ew = (rect.width() as f64 * ppp as f64).max(1.0);
-    let eh = (rect.height() as f64 * ppp as f64).max(1.0);
-    let want = ew / eh;
-    let got = w as f64 / h as f64;
-    (got - want).abs() <= 0.02 * want.max(1.0)
-}
-
-/// What a `ui.screenshot` captures.
-///
-/// A panel or element is an identity, not a rectangle: it is resolved again when the capture is
-/// issued, after the settle passes, so a panel that moved or resized while the UI settled is
-/// captured where it is now (never with the rectangle from request admission).
-#[derive(Clone, Debug, PartialEq)]
-pub enum ShotTarget {
-    /// The whole root surface.
-    Window,
-    /// A fixed rectangle in logical points, relative to the root surface's top-left corner.
-    Rect([f32; 4]),
-    /// One dock panel's automation rectangle (`panel.<id>`).
-    Panel(PanelKind),
-    /// One automation element id's rectangle.
-    Id(String),
-}
-
 /// One `ui.screenshot` request: its reply, its admission reservation and its completion slot.
 struct PendingShot {
     path: Option<String>,
@@ -239,35 +146,6 @@ pub enum Dialog {
     DeleteTemplate,
 }
 
-/// The desktop's light or dark appearance where egui cannot see it (Wayland compositors that send
-/// winit no theme). `None` = the host does not know.
-pub type SystemThemeFn = Box<dyn Fn(&egui::Context) -> Option<egui::Theme>>;
-
-/// A file dialog a host shows without blocking the frame ([`Hooks::file_dialog_async`]).
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub enum FileDialog {
-    /// Files to open or import with these extensions; several when `many`.
-    Open { exts: Vec<String>, many: bool },
-    /// An EffectCraft project to open.
-    OpenProject,
-    /// A folder.
-    Folder,
-    /// Where to save `default` (a file name or path) with extension `ext` (empty: no filter);
-    /// `project`: the project save dialog, given the file name.
-    Save { default: String, ext: String, project: bool },
-}
-
-impl FileDialog {
-    /// The save dialog for `default`, as [`Hooks::save_dialog`] picks it.
-    pub fn save(default: &str) -> Self {
-        let ext = std::path::Path::new(default).extension().map(|e| e.to_string_lossy().to_string()).unwrap_or_default();
-        Self::Save { default: default.to_string(), project: ext.eq_ignore_ascii_case("ecproj"), ext }
-    }
-}
-
-/// Called with the paths a [`FileDialog`] picked (empty: cancelled), from any thread.
-pub type DialogDone = Box<dyn FnOnce(Vec<String>) + Send>;
-
 /// A non-blocking file dialog's answer for the command that asked (`menus::dialog_answered`).
 pub(crate) struct DialogAnswer {
     pub command: String,
@@ -276,59 +154,6 @@ pub(crate) struct DialogAnswer {
     pub paths: Vec<String>,
 }
 
-/// Host hooks provided by the native app (file pickers etc.).
-#[derive(Default)]
-pub struct Hooks {
-    /// The system appearance for Settings ▸ Appearance ▸ Sync with System (the desktop app reads
-    /// the Linux desktop portal); without it, what egui reports.
-    pub system_theme: Option<SystemThemeFn>,
-    pub pick_files: Option<Box<dyn Fn(&[&str]) -> Vec<String>>>,
-    pub pick_save: Option<Box<dyn Fn(&str) -> Option<String>>>,
-    pub pick_open_project: Option<Box<dyn Fn() -> Option<String>>>,
-    /// Opens the audio output for preview playback (the desktop app uses cpal).
-    pub audio_device: Option<audio::AudioDeviceFactory>,
-    /// Lists audio output devices (Settings ▸ Audio).
-    pub audio_devices: Option<Box<dyn Fn() -> Vec<String>>>,
-    /// Picks a folder (Settings paths).
-    pub pick_folder: Option<Box<dyn Fn() -> Option<String>>>,
-    /// Save dialog for other file kinds: (default name or path, extension; empty: no filter). A
-    /// default path opens the dialog in its folder.
-    pub pick_save_file: Option<Box<dyn Fn(&str, &str) -> Option<String>>>,
-    /// The system clipboard's text (native menu Edit ▸ Paste into a text field).
-    pub clipboard_text: Option<Box<dyn Fn() -> Option<String>>>,
-    /// Application actions the OS performs (`app.hide`, `app.hideOthers`, `app.showAll` on
-    /// macOS). Returns false when the host doesn't handle the id.
-    pub app_action: Option<Box<dyn Fn(&str) -> bool>>,
-    /// Shows a command's file dialog without blocking the frame and calls `done` with the
-    /// answer (the host then asks for a repaint). Used in place of the blocking pickers above for
-    /// the commands' dialogs (File ▸ Import, Open, Save As…) where blocking the frame is unsafe or
-    /// leaves the window unresponsive: on macOS a nested modal event loop there aborted the app on
-    /// a drag over the window (#511), and on Linux a blocking desktop-portal dialog never pumps
-    /// events, so the compositor marks the window as not responding (#1275).
-    pub file_dialog_async: Option<Box<dyn Fn(FileDialog, DialogDone)>>,
-    /// Tells the user the graphics device was lost and the window is closing, once. `saved` is
-    /// the auto-save of unsaved changes (`None`: nothing was unsaved), its path or why it failed.
-    pub device_lost: Option<Box<dyn Fn(Option<Result<String, String>>)>>,
-}
-
-impl Hooks {
-    /// The host's save dialog for `default` (a file name or path), offering its extension: the
-    /// project dialog for project files, else [`Hooks::pick_save_file`]. The project dialog is
-    /// the fallback for hosts without that (the web, whose dialog only names the file): on macOS
-    /// a dialog filtered to projects appends `.ecproj` to any other name (#293). `None` when the
-    /// host has no save dialog; `Some(None)` when it was cancelled.
-    pub fn save_dialog(&self, default: &str) -> Option<Option<String>> {
-        let path = std::path::Path::new(default);
-        let ext = path.extension().map(|e| e.to_string_lossy().to_string()).unwrap_or_default();
-        match (&self.pick_save_file, &self.pick_save) {
-            (Some(pick), _) if !ext.eq_ignore_ascii_case("ecproj") => Some(pick(default, &ext)),
-            (_, Some(pick)) => Some(pick(&path.file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_default())),
-            (Some(pick), None) => Some(pick(default, &ext)),
-            (None, None) => None,
-        }
-    }
-}
-
 #[derive(Default)]
 pub struct Playback {
     pub playing: bool,
@@ -531,2132 +356,6 @@ pub struct EffectcraftApp {
 /// The saved workspaces in the settings store ([`effectcraft_engine::config::ConfigStore`]).
 pub const WORKSPACES_FILE: &str = "workspaces.json";
 
-/// The comp frames a playback pass covers (`first..=last`).
-#[derive(Clone, Copy, Debug)]
-struct FrameWindow {
-    first: i64,
-    last: i64,
-}
-
-/// The inputs of one playback pass: the viewer series it renders, the preview plan and
-/// position, and the frame range and clock settings its steps share. `queued` is a snapshot of
-/// the in-flight render count that each step copies. Built once in `advance_playback`.
-#[derive(Clone, Copy)]
-struct PlaybackPass<'a> {
-    ctx: &'a egui::Context,
-    comp: &'a effectcraft_engine::project::Comp,
-    cid: ItemId,
-    scale: f64,
-    now: f64,
-    frame_rate: effectcraft_engine::time::FrameRate,
-    series: FrameKey,
-    plan: Option<effectcraft_engine::preview::PreviewPlan>,
-    window: FrameWindow,
-    cur: i64,
-    video: bool,
-    looping: bool,
-    ahead: i64,
-    queued: usize,
-}
-
-impl EffectcraftApp {
-    /// Build the app around `session`.
-    /// Loads and applies the workspaces saved in the session's config directory (a failed load is reported in
-    /// `ui.status`), initializes the default UI, playback and render state, and registers the frontend's commands as
-    /// shortcutable `UiCommand`s on the session.
-    pub fn new(session: Session) -> Self {
-        let mut ui = UiState::default();
-        let workspace_store = workspace_state::WorkspaceStore::load(session.config.as_deref(), &mut ui);
-        EffectcraftApp {
-            session,
-            ui,
-            workspace_store,
-            tokens: Tokens::for_kind(Default::default()),
-            auto: Default::default(),
-            frames: Frames::default(),
-            playback: Playback::default(),
-            dialog: None,
-            hooks: Hooks::default(),
-            fps: 60.0,
-            clock: AppClock::default(),
-            now: 0.0,
-            last_time: 0.0,
-            styled: false,
-            fonts_ready: false,
-            styled_language: "",
-            focused: true,
-            input_active: false,
-            last_pointer_down: false,
-            draw_geom: None,
-            geometry_epoch: 0,
-            ime_tracker: egui::ImeContextTracker::new(),
-            ui_pass_seq: 0,
-            want_paint: false,
-            synthetic_in_flight: false,
-            synthetic_in_flight_events: vec![],
-            last_viewer_scale: None,
-            control_rx: None,
-            deferred: vec![],
-            synthetic: vec![],
-            forwarded: ForwardedInput::default(),
-            input_waiters: vec![],
-            job_waiters: vec![],
-            pending_screenshots: vec![],
-            shot_bytes: 0,
-            last_activity: (0.0, 0),
-            last_edit: (0.0, 0),
-            toast: None,
-            viewer_tex: None,
-            passive_tex: std::collections::HashMap::new(),
-            viewer_native: None,
-            viewer_shown: None,
-            viewer_image: None,
-            viewer_readback: Default::default(),
-            wgpu: None,
-            gpu: None,
-            gpu_checked: false,
-            gpu_failures: None,
-            gpu_failure_applied: None,
-            device_lost_close: None,
-            dialog_answers: std::sync::mpsc::channel(),
-            file_dialogs: FileDialogsUp::default(),
-            command_inbox: None,
-            pointer_comp: None,
-            dialog_state: Default::default(),
-            integrated_titlebar: false,
-            audio: None,
-            scrub: None,
-            meter: Default::default(),
-            expression_diagnostics: Default::default(),
-            waveforms: Default::default(),
-            last_reveal: None,
-            applied_prefs: None,
-            recovery: None,
-            dock_rects: vec![],
-            native_viewports: vec![],
-            unpublished_viewports: vec![],
-            pending_panel_raise: None,
-            home_thumbs: Default::default(),
-            home_thumb_saved: None,
-            window_title: String::new(),
-            template_thumbs: Default::default(),
-            template_list: None,
-            updates_rt: updates_ui::Runtime::default(),
-        }
-        .with_ui_commands()
-    }
-
-    /// Keep the saved workspaces for the next session (see [`EffectcraftApp::new`]): After
-    /// Effects' saved workspaces last until they are deleted (#320). `Err` when they weren't
-    /// written (#696): the change applies for this session and a later save retries it, but until
-    /// then a restart brings back what is on disk.
-    pub(crate) fn store_saved_workspaces(&mut self) -> Result<(), String> {
-        let Err(error) = self.workspace_store.save_now(self.session.config.as_deref(), &self.ui) else { return Ok(()) };
-        let message = format!("Workspace changes couldn't be saved and may be lost after a restart: {error}");
-        log::warn!("{message}");
-        self.ui.status = message.clone();
-        // The raw error, so the background retry doesn't report the same failure again.
-        self.workspace_store.error = Some(error);
-        Err(message)
-    }
-
-    /// Offer the frontend's commands (tools, timeline navigation…) for keyboard shortcuts.
-    fn with_ui_commands(mut self) -> Self {
-        let cmds = menus::UI_COMMANDS
-            .iter()
-            .map(|c| effectcraft_engine::shortcuts::UiCommand { id: c.id.into(), label: c.label.into(), shortcut: c.shortcut.map(str::to_string) })
-            .collect();
-        self.session.set_ui_commands(cmds);
-        self
-    }
-
-    /// Show the crash-recovery dialog for a previous run that didn't exit cleanly.
-    pub fn offer_recovery(&mut self, r: effectcraft_engine::autosave::Recovery) {
-        if r.autosave.is_some() {
-            self.recovery = Some(r);
-            self.dialog = Some(Dialog::Recovery);
-        }
-    }
-
-    /// Apply changed settings: theme and brightness, label colours, tool tips, preview caches.
-    pub fn apply_prefs(&mut self, ctx: &egui::Context) {
-        // Sync with System re-applies when the system appearance changes (the host wakes the UI;
-        // nothing polls).
-        let system = if self.session.prefs.appearance.appearance_mode == "auto" { self.system_light(ctx) } else { None };
-        if self.applied_prefs == Some((self.session.prefs_revision, system)) {
-            return;
-        }
-        self.applied_prefs = Some((self.session.prefs_revision, system));
-        let p = &self.session.prefs;
-        self.ui.theme = theme::ThemeKind::from_name(p.appearance.resolved_theme(system)).unwrap_or_default();
-        self.tokens = Tokens::from_prefs(p, self.ui.theme);
-        theme::apply_visuals(ctx, &self.tokens);
-        ctx.set_theme(theme::theme_preference(&p.appearance.appearance_mode, self.ui.theme.is_light()));
-        let tips = p.general.show_tool_tips;
-        ctx.all_styles_mut(|s| s.interaction.tooltip_delay = if tips { 0.5 } else { f32::INFINITY });
-        // Settings ▸ Appearance ▸ UI Scale (#284). egui's own Ctrl+= / Ctrl+- / Ctrl+0 zoom stays
-        // off: Ctrl+0 is Window ▸ Project, and the scale is a setting.
-        ctx.options_mut(|o| o.zoom_with_keyboard = false);
-        ctx.set_zoom_factor(p.appearance.ui_scale as f32 / 100.0);
-        self.ui.cache_when_idle = p.previews.cache_frames_when_idle;
-        self.ui.viewer.fast_preview = p.previews.fast_previews;
-        self.frames.set_budget(p.cache_budgets(self.session.sys_memory).preview);
-    }
-
-    /// Change settings from the UI (applied next frame and saved).
-    pub fn set_pref(&mut self, key: &str, value: serde_json::Value) -> Result<(), String> {
-        self.session.prefs.set(key, value)?;
-        self.session.prefs_changed();
-        self.session.save_prefs();
-        Ok(())
-    }
-
-    pub fn with_control(mut self, rx: Receiver<ControlRequest>) -> Self {
-        self.control_rx = Some(rx);
-        self
-    }
-
-    /// Show theme `k`: the appearance mode becomes its family's (Dark or Light), and `k` that
-    /// family's theme.
-    pub fn set_theme(&mut self, ctx: &egui::Context, k: theme::ThemeKind) {
-        if let Err(e) = self.set_pref("appearance.theme", json!(k.name())) {
-            self.ui.status = e;
-        }
-        self.apply_prefs(ctx);
-    }
-
-    /// The system appearance: light (`Some(true)`), dark, or unknown. The host's answer (the Linux
-    /// desktop portal) wins over egui's, which Wayland compositors often leave empty.
-    pub fn system_light(&self, ctx: &egui::Context) -> Option<bool> {
-        self.hooks.system_theme.as_ref().and_then(|read| read(ctx)).or_else(|| ctx.system_theme()).map(|t| t == egui::Theme::Light)
-    }
-
-    /// The Tools bar's appearance button (`view.theme.toggle`): Sync with System, then Light, then
-    /// Dark, then Sync with System again. The light and dark theme choices are kept.
-    pub fn cycle_appearance(&mut self, ctx: &egui::Context) {
-        let next = match self.session.prefs.appearance.appearance_mode.as_str() {
-            "auto" => "light",
-            "light" => "dark",
-            _ => "auto",
-        };
-        if let Err(e) = self.set_pref("appearance.appearanceMode", json!(next)) {
-            self.ui.status = e;
-        }
-        self.apply_prefs(ctx);
-    }
-
-    pub fn set_workspace(&mut self, name: &str) {
-        // Learn: the Home screen's Learn tab (tutorials) in the Composition panel. Leaving it for
-        // another workspace closes the Home screen again: it stayed over every workspace until a
-        // project was created (#272).
-        if name == "Learn" {
-            self.ui.start_screen = true;
-            self.ui.home_learn = true;
-            self.ui.home_templates = false;
-        } else if self.ui.workspace == "Learn" {
-            self.ui.start_screen = false;
-            self.ui.home_learn = false;
-        }
-        self.ui.workspace = name.to_string();
-        self.ui.dock = self.ui.saved_workspaces.get(name).cloned().unwrap_or_else(|| dock::Workspace::new(dock::workspace(name)));
-        self.ui.maximized = None;
-    }
-
-    /// Built-in workspaces followed by the saved ones (Window ▸ Workspace ▸ Save as New Workspace).
-    pub fn workspace_names(&self) -> Vec<String> {
-        let mut v: Vec<String> = dock::WORKSPACES.iter().map(|s| s.to_string()).collect();
-        v.extend(self.saved_workspace_names());
-        v
-    }
-
-    /// The workspaces the user saved under a new name (built-ins whose changes were saved are
-    /// not repeated), in name order.
-    pub fn saved_workspace_names(&self) -> Vec<String> {
-        self.ui.saved_workspaces.keys().filter(|k| !dock::WORKSPACES.contains(&k.as_str())).cloned().collect()
-    }
-
-    /// The open Gradient Editor's draft (`panels::gradient_editor`): what OK would set.
-    pub fn gradient_draft(&self) -> &panels::gradient_editor::Draft {
-        &self.dialog_state.gradient
-    }
-
-    /// The open Gradient Editor's draft, to edit (tests and automation; the editor's own fields
-    /// do the same).
-    pub fn gradient_draft_mut(&mut self) -> &mut panels::gradient_editor::Draft {
-        &mut self.dialog_state.gradient
-    }
-
-    /// Feed this frame's share of the queued synthetic input (control channel `ui.click`,
-    /// `ui.drag`…) into `raw_input`. Pointer events go one per frame so egui sees press → moves
-    /// → release as a real gesture.
-    ///
-    /// Only one batch is ever moved out at a time, even when the host prepares several hidden
-    /// logic-only iterations before the forced UI pass: eframe keeps the last prepared raw input
-    /// and would otherwise apply a whole drag or click as one burst. A batch is released by the
-    /// first UI pass that applies it ([`Self::mark_synthetic_applied`]). Callers must not feed a
-    /// pass that cannot draw (fonts still installing): egui applies what it receives, so putting
-    /// an applied batch back would apply its pointer/key state twice.
-    pub fn feed_synthetic(&mut self, raw_input: &mut egui::RawInput) {
-        if self.synthetic_in_flight || self.synthetic.is_empty() {
-            return;
-        }
-        // Pointer events go one per frame so egui sees press → moves → release as a real drag.
-        let pointer = |e: &egui::Event| matches!(e, egui::Event::PointerMoved(_) | egui::Event::PointerButton { .. } | egui::Event::MouseWheel { .. });
-        let n = if pointer(&self.synthetic[0]) {
-            1
-        } else {
-            self.synthetic
-                .iter()
-                .position(|e| pointer(e) || matches!(e, egui::Event::Key { pressed: false, .. }))
-                .map_or(self.synthetic.len(), |i| if pointer(&self.synthetic[i]) { i.max(1) } else { i + 1 })
-        };
-        let batch: Vec<egui::Event> = self.synthetic.drain(..n).collect();
-        raw_input.events.extend(batch.iter().cloned());
-        self.synthetic_in_flight_events.extend(batch);
-        self.synthetic_in_flight = true;
-    }
-
-    /// Clear the single-pending-batch guard: a UI pass has applied the injected batch.
-    ///
-    /// [`EffectcraftApp::draw`] calls this itself; harnesses that feed synthetic input
-    /// themselves (the headless kittest tests) call it after each pass they ran.
-    pub fn mark_synthetic_applied(&mut self) {
-        self.synthetic_in_flight_events.clear();
-        self.synthetic_in_flight = false;
-    }
-
-    /// The events of the injected batch that no UI pass has applied yet.
-    pub fn pending_synthetic_events(&self) -> &[egui::Event] {
-        &self.synthetic_in_flight_events
-    }
-
-    /// Whether a synthetic batch is waiting for its UI pass.
-    pub fn synthetic_in_flight(&self) -> bool {
-        self.synthetic_in_flight
-    }
-
-    /// The app clock's value at the last tick.
-    pub fn now(&self) -> f64 {
-        self.now
-    }
-
-    /// The clock itself (tests advance a manual clock).
-    pub fn clock_mut(&mut self) -> &mut AppClock {
-        &mut self.clock
-    }
-
-    /// Use a test-driven clock from now on.
-    pub fn use_manual_clock(&mut self) {
-        self.clock = AppClock::manual();
-        self.now = 0.0;
-    }
-
-    /// Completed, non-discarded UI passes since launch.
-    pub fn ui_passes(&self) -> u64 {
-        self.ui_pass_seq
-    }
-
-    /// The geometry of the last completed UI pass, if one ran.
-    pub fn draw_geometry(&self) -> Option<DrawGeometry> {
-        self.draw_geom
-    }
-
-    /// Show panel `p` (opening it in its usual place if it is closed), bring it to the front and
-    /// give it the focus: Window ▸ `<panel>`.
-    pub fn show_panel(&mut self, p: PanelKind) {
-        if !self.ui.dock.is_floating(p) && self.ui.maximized.is_some_and(|m| m != p) {
-            self.ui.maximized = None;
-        }
-        self.raise_panel(p);
-        self.ui.focused = p;
-    }
-
-    /// Bring panel `p` to the front of its group, opening it if it is closed, without moving the
-    /// focus (a comp opening brings up its viewer, an effect applied brings up Effect Controls).
-    /// A closed panel goes back where it was; one never laid out goes to its usual place: the
-    /// Composition panel in the centre with the Layer panel and other viewers (with none of
-    /// those left, above the Timeline), Layer and the viewers beside the Composition panel, and
-    /// so on.
-    pub fn raise_panel(&mut self, p: PanelKind) {
-        if !self.ui.dock.is_open(p) {
-            let docked = |q: &PanelKind| self.ui.dock.is_docked(*q);
-            let near = match p {
-                PanelKind::Composition => self
-                    .ui
-                    .dock
-                    .panels()
-                    .into_iter()
-                    .find(|q| matches!(q, PanelKind::Layer | PanelKind::Viewer(_) | PanelKind::Flowchart | PanelKind::Footage) && docked(q)),
-                PanelKind::Layer | PanelKind::Flowchart | PanelKind::Viewer(_) => Some(PanelKind::Composition),
-                PanelKind::RenderQueue => Some(PanelKind::Timeline),
-                PanelKind::EffectControls | PanelKind::History => Some(PanelKind::Project),
-                _ => Some(PanelKind::EffectsPresets),
-            }
-            .filter(|q| self.ui.dock.is_open(*q));
-            let mut workspace = self.ui.dock.clone();
-            let known = workspace.hidden.iter().any(|(q, _)| *q == p);
-            let opened = if p == PanelKind::Composition && near.is_none() && !known && self.ui.dock.is_docked(PanelKind::Timeline) {
-                workspace
-                    .apply(
-                        craft_ui::docking::Action::OpenAt {
-                            panel: p,
-                            anchor: PanelKind::Timeline,
-                            placement: craft_ui::docking::Placement::Split(craft_ui::docking::Zone::Top),
-                        },
-                        dock::permissions,
-                    )
-                    .map(|_| ())
-            } else if known {
-                workspace.set_visible(p, true, near, dock::permissions)
-            } else {
-                workspace.apply(craft_ui::docking::Action::Open { panel: p, anchor: near }, dock::permissions).map(|_| ())
-            };
-            match opened {
-                Ok(()) => self.ui.dock = workspace,
-                Err(e) => {
-                    self.ui.status = format!("can't open {}: {e}", p.title());
-                    return;
-                }
-            }
-        }
-        let _ = self.ui.dock.apply(craft_ui::docking::Action::Activate { panel: p }, dock::permissions);
-        if self.ui.dock.is_floating(p) {
-            self.pending_panel_raise = Some(p);
-        }
-    }
-
-    pub fn render_source(&self) -> RenderSource {
-        RenderSource {
-            project: self.session.project.clone(),
-            footage: self.session.footage.clone(),
-            expr: self.session.expr.clone(),
-            layer_cache: self.session.layer_cache.clone(),
-            gpu: self.gpu.clone(),
-            gpu_display: self.gpu_display(),
-            disk: self.session.disk_cache.clone(),
-        }
-    }
-
-    /// Keep GPU-composited viewer frames on the GPU (drawn from their texture). The browser can't
-    /// read frames back (its thread can't wait for the GPU), so there the viewer shows GPU frames
-    /// directly whenever it draws them plainly (RGB, no exposure, no region of interest); the
-    /// desktop reads them back (see [`frames::RenderSource::gpu_display`]).
-    fn gpu_display(&self) -> bool {
-        let v = &self.session.state.viewer;
-        cfg!(target_arch = "wasm32")
-            && v.channel == effectcraft_engine::viewer::Channel::Rgb
-            && v.exposure == 0.0
-            && self.session.state.region_of_interest.is_none()
-            && self.ui.viewer.extended.is_none()
-    }
-
-    /// The UI draws its panels and handles input such as dropped files. Until the fonts are
-    /// installed (the first frames) it draws nothing, and that input goes unhandled.
-    pub fn is_ready(&self) -> bool {
-        self.fonts_ready
-    }
-
-    /// Provide the executable/embedding host's device notifications. The host installs the
-    /// handlers once; this frontend never replaces handlers on a borrowed device.
-    pub fn set_gpu_failure_bridge(&mut self, bridge: gpu_failure::GpuFailureBridge) {
-        if let Some(gpu) = &self.gpu {
-            bridge.forward_to(gpu.context().device_failure_notifier());
-        }
-        self.gpu_failures = Some(bridge);
-    }
-
-    fn apply_gpu_failure(&mut self, ctx: &egui::Context) {
-        let Some(bridge) = &self.gpu_failures else { return };
-        // Readback deadlines can retire the compositor without a host device notification.
-        if let Some(gpu) = &self.gpu
-            && let Err(reason) = gpu.context().check_health()
-        {
-            bridge.report(&reason, false);
-        }
-        let Some(failure) = bridge.failure() else { return };
-        if self.gpu_failure_applied == Some(failure.presentation_lost) {
-            return;
-        }
-        self.gpu_failure_applied = Some(failure.presentation_lost);
-        self.gpu_checked = true;
-        self.frames.retire_gpu();
-        self.session.accel = None;
-        self.session.accel_note = Some(format!("GPU preview retired: {}", failure.reason));
-        self.session.layer_cache.clear();
-        self.gpu = None;
-        if let Some(rs) = &self.wgpu {
-            let mut renderer = rs.renderer.write();
-            if let Some((id, _, _)) = &self.viewer_native {
-                renderer.free_texture(id);
-            }
-            for (_, texture) in self.passive_tex.values() {
-                if let panels::viewers::PassiveTexture::Gpu(id, _) = texture {
-                    renderer.free_texture(id);
-                }
-            }
-        }
-        self.viewer_native = None;
-        self.passive_tex.retain(|_, (_, texture)| matches!(texture, panels::viewers::PassiveTexture::Cpu(_)));
-        self.viewer_shown = self.viewer_tex.as_ref().map(|(texture, key, _)| (texture.id(), *key));
-        self.viewer_image = None;
-        // Old completion closures retain only their detached slot, not the replacement.
-        self.viewer_readback = Default::default();
-        self.wgpu = None;
-        self.ui.status = if failure.presentation_lost {
-            "Graphics device lost. The project is still open; presentation requires restarting the application.".into()
-        } else {
-            "Shared GPU preview disabled; CPU compositing remains available.".into()
-        };
-        log::warn!("GPU preview retired: {}", failure.reason);
-        ctx.request_repaint();
-    }
-
-    /// After the graphics device is lost, eframe's renderer cannot draw again: any mesh makes
-    /// egui-wgpu panic on the main thread when it cannot stage its index buffer (#591). Draw
-    /// nothing from then on, auto-save a project with unsaved changes (keeping the crash
-    /// recovery marker, so the next launch offers it) and close the window.
-    fn close_after_device_loss(&mut self, ctx: &egui::Context) {
-        if self.device_lost_close.is_some() {
-            return;
-        }
-        let keep_recovery = self.session.is_dirty();
-        let saved = keep_recovery.then(|| match self.session.autosave_now().and_then(|path| self.session.autosave_wait().map(|()| path)) {
-            Ok(path) => {
-                log::warn!("graphics device lost: auto-saved {path}; the next launch offers to recover it");
-                Ok(path)
-            }
-            Err(e) => {
-                log::error!("graphics device lost: {e}");
-                Err(e.to_string())
-            }
-        });
-        self.device_lost_close = Some(keep_recovery);
-        log::warn!("graphics device lost: closing the window");
-        if let Some(tell) = &self.hooks.device_lost {
-            tell(saved);
-        }
-        ctx.send_viewport_cmd(egui::ViewportCommand::Close);
-    }
-
-    /// Run the commands whose non-blocking file dialogs have been answered.
-    pub(crate) fn run_dialog_answers(&mut self) {
-        while let Ok(answer) = self.dialog_answers.1.try_recv() {
-            self.file_dialogs.answered();
-            menus::dialog_answered(self, answer);
-        }
-    }
-
-    /// Set up the GPU compositor on egui-wgpu's device (once). Without an adapter that runs
-    /// compute shaders (WebGL2, software GL) everything stays on the CPU.
-    pub(crate) fn init_gpu(&mut self, frame: &eframe::Frame) {
-        if self.gpu_checked {
-            return;
-        }
-        self.gpu_checked = true;
-        if self.gpu_failures.as_ref().is_some_and(|bridge| bridge.failure().is_some()) {
-            return;
-        }
-        let Some(rs) = frame.wgpu_render_state() else { return };
-        // Help ▸ System Compatibility Report names the adapter and backend the window got.
-        let info = rs.adapter.get_info();
-        self.session.window_adapter = Some(format!(
-            "{} ({:?}, {:?}{})",
-            info.name,
-            info.backend,
-            info.device_type,
-            if info.driver.is_empty() { String::new() } else { format!(", {} {}", info.driver, info.driver_info) }
-        ));
-        // Backend validation can panic on shader compilation even when device creation
-        // succeeded. Keep the document and the egui renderer, and use CPU compositing.
-        let gpu = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| effectcraft_gpu::Gpu::new(&rs.adapter, rs.device.clone(), rs.queue.clone())));
-        match gpu {
-            Ok(Ok(g)) => {
-                if let Some(bridge) = &self.gpu_failures {
-                    bridge.forward_to(g.context().device_failure_notifier());
-                    if bridge.failure().is_some() {
-                        return;
-                    }
-                }
-                log::info!("GPU compositor: {}", effectcraft_engine::render::Accelerator::name(&g));
-                self.session.accel = Some(Arc::new(g.clone()));
-                self.gpu = Some(g);
-                self.wgpu = Some(rs.clone());
-            }
-            Ok(Err(e)) => {
-                log::info!("GPU compositor unavailable: {e}");
-                self.session.accel_note = Some(format!("GPU compositor unavailable: {e}"));
-            }
-            Err(e) => {
-                let reason = e.downcast_ref::<String>().map(String::as_str).or_else(|| e.downcast_ref::<&str>().copied()).unwrap_or("backend panicked");
-                log::warn!("GPU compositor setup failed; using CPU compositing: {reason}");
-                self.session.accel_note = Some(format!("GPU compositor setup failed: {reason}"));
-            }
-        }
-    }
-
-    /// The viewer shows a frame composited on the GPU (drawn from its wgpu texture).
-    pub fn viewer_on_gpu(&self) -> bool {
-        matches!((&self.viewer_shown, &self.viewer_native), (Some(s), Some(n)) if s.1 == n.1)
-    }
-
-    /// The GPU compositor's adapter, when the viewer has one.
-    pub fn gpu_adapter(&self) -> Option<String> {
-        self.gpu.as_ref().map(effectcraft_engine::render::Accelerator::name)
-    }
-
-    /// The size of the viewer frame's texture (CPU frames; fitted to the GPU's texture limit).
-    pub fn viewer_texture_size(&self) -> Option<[usize; 2]> {
-        self.viewer_tex.as_ref().map(|(t, _, _)| t.size())
-    }
-
-    /// The viewer's current pixels as 8-bit premultiplied RGBA, reading a GPU frame back the
-    /// first time something asks for it.
-    ///
-    /// The browser can't wait for the GPU: there the first call starts an asynchronous readback
-    /// and returns `None`; a later call (the next frame) has the pixels.
-    pub fn viewer_pixels(&mut self) -> Option<Arc<egui::ColorImage>> {
-        let to_image = |bytes: Vec<u8>, w: u32, h: u32| {
-            let px = bytes.as_chunks::<4>().0.iter().map(|c| egui::Color32::from_rgba_premultiplied(c[0], c[1], c[2], c[3])).collect();
-            Arc::new(egui::ColorImage::new([w as usize, h as usize], px))
-        };
-        if self.viewer_image.is_none()
-            && let (Some((_, key, f)), Some(g)) = (&self.viewer_native, &self.gpu)
-            && self.viewer_shown.as_ref().map(|s| s.1) == Some(*key)
-        {
-            if cfg!(target_arch = "wasm32") {
-                let ready = self.viewer_readback.1.lock().ok().and_then(|mut r| r.take_if(|r| r.0 == *key));
-                if let Some((_, img)) = ready {
-                    self.viewer_image = Some(img);
-                } else if self.viewer_readback.0 != Some(*key) {
-                    self.viewer_readback.0 = Some(*key);
-                    let (slot, k, (w, h)) = (self.viewer_readback.1.clone(), *key, (f.width, f.height));
-                    let ctx = self.frames.context();
-                    g.read_display_async(f, move |bytes| {
-                        if let (Some(b), Ok(mut s)) = (bytes, slot.lock()) {
-                            *s = Some((k, to_image(b, w, h)));
-                        }
-                        if let Some(c) = ctx {
-                            c.request_repaint();
-                        }
-                    });
-                }
-            } else if let Some(bytes) = g.read_display(f) {
-                self.viewer_image = Some(to_image(bytes, f.width, f.height));
-            }
-        }
-        self.viewer_image.clone()
-    }
-
-    /// The viewer's Resolution: the active composition's (saved with the project).
-    pub fn viewer_res(&self) -> state::Resolution {
-        self.session.active_comp().map(|c| c.resolution).unwrap_or_default()
-    }
-
-    /// The render scale used by the viewer right now.
-    pub fn viewer_scale(&self, zoom: f32, ppp: f32) -> f64 {
-        // The preview's Resolution (when not Auto) while it plays.
-        if self.playback.playing
-            && let Some(f) = self.playback.res
-        {
-            return state::Resolution::from_factor(f.into()).scale(zoom, ppp);
-        }
-        // Auto follows the zoom alike while playing and paused, so frames cached while scrubbing
-        // play back, and frames cached by a preview stay on screen when it stops.
-        let res = self.viewer_res();
-        let full = res.scale(zoom, ppp);
-        // Fast Previews ▸ Adaptive Resolution / Fast Draft: lower resolution while dragging.
-        let (_, k) = self.session.state.viewer.fast_previews.render(self.ui.viewer.interacting || self.ui.viewer.property_interacting);
-        if k < 1.0 && res.is_auto() {
-            return full.min((full * 0.5).max(self.session.prefs.adaptive_limit()));
-        }
-        full
-    }
-
-    /// The cache key of viewer frame `frame` of `comp` at `scale` (see [`Self::frame_series`]).
-    pub fn frame_key(&self, comp: ItemId, frame: i64, scale: f64) -> FrameKey {
-        FrameKey { frame, ..self.frame_series(comp, scale) }
-    }
-
-    /// The key of frame 0 of `comp`'s viewer frames at `scale` (the content, view and render
-    /// options are the same for every frame: loops compute this once).
-    pub fn frame_series(&self, comp: ItemId, scale: f64) -> FrameKey {
-        FrameKey {
-            revision: self.session.revision,
-            content: self.frames.content_of(&self.session.project, self.session.revision, comp),
-            comp: comp.0,
-            frame: 0,
-            scale: (scale * 1000.0).round() as u32,
-            view: self.view_hash(comp),
-            opts: frames::opts_hash(&self.frame_opts(comp, scale)),
-        }
-    }
-
-    /// The frame series the viewer of `comp` shows now (its scale, view and options, for the
-    /// comp's current content): what the cache bars count.
-    pub fn shown_series(&self, comp: ItemId) -> FrameKey {
-        let scale = self.viewer_shown.as_ref().filter(|(_, k)| k.comp == comp.0).map_or(1000, |(_, k)| k.scale);
-        self.frame_series(comp, scale as f64 / 1000.0)
-    }
-
-    /// Hash of the comp viewer's 3D view camera (0 for the active camera view).
-    pub fn view_hash(&self, comp: ItemId) -> u64 {
-        use std::hash::{Hash, Hasher};
-        let mut h = std::collections::hash_map::DefaultHasher::new();
-        // The region of interest changes what is rendered too.
-        let roi = self.viewer_region(comp);
-        if let Some(r) = roi {
-            r.map(f64::to_bits).hash(&mut h);
-        }
-        let Some(cam) = self.session.view_camera(comp) else { return if roi.is_some() { h.finish() | 1 } else { 0 } };
-        for row in cam.view.0 {
-            for v in row {
-                v.to_bits().hash(&mut h);
-            }
-        }
-        cam.zoom.to_bits().hash(&mut h);
-        cam.ortho.hash(&mut h);
-        h.finish() | 1
-    }
-
-    /// The comp-space region viewer frames of `comp` cover: the region of interest, else the
-    /// Extended Viewer's area (frame plus pasteboard), else `None` (the whole frame).
-    pub fn viewer_region(&self, comp: ItemId) -> Option<[f64; 4]> {
-        if self.session.active_comp_id() != Some(comp) {
-            return None;
-        }
-        self.session.state.region_of_interest.or(self.ui.viewer.extended)
-    }
-
-    /// Request a prefetch frame render (no-op if cached/in flight).
-    pub fn request_frame(&self, comp: ItemId, frame: i64, scale: f64) {
-        self.request_frame_with(comp, frame, scale, false);
-    }
-
-    /// Request the frame on screen: rendered before any queued prefetch.
-    pub fn request_frame_urgent(&self, comp: ItemId, frame: i64, scale: f64) {
-        self.request_frame_with(comp, frame, scale, true);
-    }
-
-    /// Render options of viewer frames of `comp` at `scale`.
-    pub fn frame_opts(&self, comp: ItemId, scale: f64) -> RenderOpts {
-        let (draft, _) = self.session.state.viewer.fast_previews.render(self.ui.viewer.interacting || self.ui.viewer.property_interacting);
-        let roi = self.viewer_region(comp);
-        RenderOpts {
-            scale,
-            motion_blur: true,
-            guides: true,
-            draft: self.ui.viewer.fast_preview || draft,
-            view: self.session.view_camera(comp),
-            roi,
-            backend: effectcraft_engine::render::Backend::Auto,
-            nested_switches: self.session.prefs.general.switches_affect_nested_comps,
-            draft_shadows: self.session.prefs.three_d.realtime_shadows,
-            proxy: Default::default(),
-        }
-    }
-
-    fn request_frame_with(&self, comp: ItemId, frame: i64, scale: f64, urgent: bool) {
-        let Some(c) = self.session.project.comp(comp) else { return };
-        let key = self.frame_key(comp, frame, scale);
-        let t = c.frame_rate.tick_of(frame);
-        let opts = self.frame_opts(comp, scale);
-        if urgent {
-            self.frames.request_urgent(&self.render_source(), key, comp, t, opts);
-        } else {
-            self.frames.request(&self.render_source(), key, comp, t, opts);
-        }
-    }
-
-    // ---------------------------------------------------------------- playback
-
-    pub fn play(&mut self, now: f64) {
-        let sc = self.session.prefs.preview.current;
-        self.play_with(now, sc);
-    }
-
-    /// Start the preview of a Preview panel shortcut (its range, play-from, rate, skip,
-    /// resolution, loop, caching, full screen and include options).
-    pub fn play_with(&mut self, now: f64, sc: effectcraft_engine::preview::PreviewShortcut) {
-        let Some(c) = self.session.active_comp_arc() else { return };
-        let preset = self.session.prefs.preview.get(sc).clone();
-        let plan = effectcraft_engine::preview::plan(&preset, &c, self.session.time());
-        let fr = c.frame_rate;
-        if plan.video {
-            self.session.set_time(fr.tick_of(plan.first));
-        }
-        let restore_max = preset.full_screen.then_some(self.ui.maximized);
-        let viewer = panels::viewers::active_panel(self);
-        if preset.full_screen && self.ui.dock.is_docked(viewer) {
-            self.ui.maximized = Some(viewer);
-        }
-        self.playback = Playback {
-            playing: true,
-            start_wall: now,
-            start_time: fr.tick_of(plan.first),
-            start_frame: plan.first,
-            shown: 0,
-            waiting: false,
-            fps: plan.fps,
-            shortcut: sc,
-            plan: Some(plan),
-            caching: plan.cache_first && plan.video,
-            res: preset.resolution.factor(preset.custom_resolution),
-            overlays: preset.include_overlays,
-            layer_controls: preset.include_layer_controls,
-            restore_max,
-            audio_frame: (!plan.video).then_some(plan.first),
-            audio_held: false,
-            shown_at: Default::default(),
-        };
-        if !self.playback.caching {
-            if plan.video {
-                self.playback.audio_held = self.audio_plays();
-            } else {
-                self.start_audio(fr.tick_of(plan.first));
-            }
-        }
-    }
-
-    /// The preview includes audio at the comp's frame rate and the comp has something audible.
-    fn audio_plays(&self) -> bool {
-        let (Some(pl), Some(cid)) = (self.playback.plan, self.session.active_comp_id()) else { return false };
-        let Some(c) = self.session.project.comp(cid) else { return false };
-        // A preview at another frame rate plays slower or faster than real time: silent.
-        pl.audio && (pl.fps - c.frame_rate.as_f64()).abs() <= 0.01 && effectcraft_engine::render::audio::comp_has_audio(&self.session.project, cid)
-    }
-
-    /// Start audio preview from comp time `t` when [`Self::audio_plays`] and an output device
-    /// opens.
-    fn start_audio(&mut self, t: Tick) {
-        self.audio = None;
-        self.meter.clipped = [false; 2];
-        let (Some(pl), Some(cid)) = (self.playback.plan, self.session.active_comp_id()) else { return };
-        let Some(c) = self.session.project.comp_arc(cid).filter(|_| self.audio_plays()) else { return };
-        let out = audio::AudioOutput::from_prefs(&self.session.prefs);
-        let Some(dev) = self.hooks.audio_device.as_ref().and_then(|f| f(&out)) else { return };
-        let mix = self.session.prefs.audio.preview_sample_rate;
-        let fr = c.frame_rate;
-        match audio::AudioPlayback::start(dev, self.render_source(), cid, t, fr.tick_of(pl.start), fr.tick_of(pl.end + 1), pl.looping, mix) {
-            Ok(a) => self.audio = Some(a),
-            Err(e) => log::warn!("audio preview: {e}"),
-        }
-    }
-
-    /// Audio scrubbing: play the frame of `comp` at `t` (see [`audio::AudioScrub`]), opening the
-    /// output on first use. Silent comps and missing devices do nothing.
-    pub fn scrub_audio(&mut self, comp: ItemId, t: Tick, now: f64) {
-        if self.playback.playing || !effectcraft_engine::render::audio::comp_has_audio(&self.session.project, comp) {
-            return;
-        }
-        if self.scrub.is_none() {
-            let out = audio::AudioOutput::from_prefs(&self.session.prefs);
-            let Some(dev) = self.hooks.audio_device.as_ref().and_then(|f| f(&out)) else { return };
-            match audio::AudioScrub::open(dev, now) {
-                Ok(s) => self.scrub = Some(s),
-                Err(e) => {
-                    log::warn!("audio scrubbing: {e}");
-                    return;
-                }
-            }
-        }
-        let src = self.render_source();
-        let mix = self.session.prefs.audio.preview_sample_rate;
-        if let Some(s) = &mut self.scrub {
-            s.play(&src, comp, t, mix, now);
-        }
-    }
-
-    pub fn stop(&mut self) {
-        let was = std::mem::replace(&mut self.playback.playing, false);
-        self.audio = None;
-        self.playback.caching = false;
-        if !was {
-            return;
-        }
-        if let Some(m) = self.playback.restore_max.take() {
-            self.ui.maximized = m;
-        }
-        let Some(pl) = self.playback.plan else { return };
-        let move_time = self.session.prefs.preview.get(self.playback.shortcut).move_time_to_preview_time;
-        if !move_time {
-            self.session.set_time(pl.origin);
-        } else if let Some(f) = self.playback.audio_frame
-            && let Some(c) = self.session.active_comp()
-        {
-            let t = c.frame_rate.tick_of(f);
-            self.session.set_time(t);
-        }
-    }
-
-    pub fn toggle_play(&mut self, now: f64) {
-        let sc = self.session.prefs.preview.current;
-        self.toggle_play_with(now, sc);
-    }
-
-    /// A preview shortcut pressed: start its preview, or stop the running one. While Cache
-    /// Before Playback is still rendering, "If caching, play cached frames" plays what is
-    /// cached so far instead of stopping.
-    pub fn toggle_play_with(&mut self, now: f64, sc: effectcraft_engine::preview::PreviewShortcut) {
-        if !self.playback.playing {
-            self.play_with(now, sc);
-            return;
-        }
-        if self.playback.caching && self.session.prefs.preview.get(self.playback.shortcut).play_cached_frames && self.play_cached(now) {
-            return;
-        }
-        self.stop();
-    }
-
-    /// Cut the caching preview down to the frames cached from its first frame on and play them.
-    fn play_cached(&mut self, now: f64) -> bool {
-        let (Some(mut pl), Some(cid)) = (self.playback.plan, self.session.active_comp_id()) else { return false };
-        let scale = self.viewer_shown.as_ref().map(|(_, k)| k.scale as f64 / 1000.0).unwrap_or(1.0);
-        let series = self.frame_series(cid, scale);
-        let mut last = None;
-        let mut f = pl.first;
-        while f <= pl.end && self.frames.is_cached(&FrameKey { frame: f, ..series }) {
-            last = Some(f);
-            f += pl.step;
-        }
-        let Some(last) = last else { return false };
-        pl.end = last;
-        pl.start = pl.first;
-        self.playback.plan = Some(pl);
-        self.playback.caching = false;
-        self.playback.start_wall = now;
-        self.playback.start_frame = pl.first;
-        let t = self.session.active_comp().map(|c| c.frame_rate.tick_of(pl.first)).unwrap_or_default();
-        self.start_audio(t);
-        true
-    }
-
-    /// A preview plays with Video off in the Preview panel (audio only): the current time stays
-    /// put, so the viewer and Timeline say so instead of looking stuck (#1118). The frame under
-    /// the audible sample, when one is known.
-    pub fn video_preview_off(&self) -> Option<Option<i64>> {
-        let p = self.playback.plan.filter(|_| self.playback.playing)?;
-        (!p.video).then_some(self.playback.audio_frame)
-    }
-
-    /// The viewer shows grids, guides and safe margins (hidden while a preview without
-    /// Include Overlays plays).
-    pub fn overlays_visible(&self) -> bool {
-        !self.playback.playing || self.playback.overlays
-    }
-
-    /// The viewer shows layer handles and paths (View ▸ Show Layer Controls, and Include Layer
-    /// Controls while a preview plays).
-    pub fn layer_controls_visible(&self) -> bool {
-        self.ui.viewer.show_layer_controls && (!self.playback.playing || self.playback.layer_controls)
-    }
-
-    /// RAM preview: advance at the preview's frame rate when frames are cached; otherwise hold
-    /// and keep rendering ahead (the green cache bar fills, then playback runs in real time).
-    fn advance_playback(&mut self, ctx: &egui::Context, scale: f64, now: f64, input_active: bool, cid: ItemId) {
-        let Some(c) = self.session.project.comp_arc(cid) else { return };
-        let fr = c.frame_rate;
-        let plan = self.playback.plan.filter(|_| self.playback.playing);
-        let (wa, wb) = match plan {
-            Some(p) => (p.start, p.end),
-            None => (fr.frame_at(c.work_area.0), fr.frame_at(c.work_area.1 - c.frame_duration())),
-        };
-        let looping = plan.is_none_or(|p| p.looping);
-        let video = plan.is_none_or(|p| p.video);
-        // Prefetch ahead.
-        let cur = fr.frame_at(self.session.time());
-        let ahead = self.prefetch_ahead(ctx, now);
-        let queued = self.frames.inflight();
-        let series = self.frame_series(cid, scale);
-        // The preview's position orders prefetch and eviction (#595).
-        let playhead = plan.filter(|p| p.video).map(|p| frames::Playhead { series, cur, start: p.start, end: p.end, step: p.step, looping: p.looping });
-        self.frames.set_playhead(playhead);
-        let pass = PlaybackPass {
-            ctx,
-            comp: &c,
-            cid,
-            scale,
-            now,
-            frame_rate: fr,
-            series,
-            plan,
-            window: FrameWindow { first: wa, last: wb },
-            cur,
-            video,
-            looping,
-            ahead,
-            queued,
-        };
-        if self.cache_preview(&pass) {
-            return;
-        }
-        let step = plan.map_or(1, |p| p.step);
-        let fit_ahead = self.frames_that_fit(&c, scale) - 1;
-        self.prefetch_playback(&pass, fit_ahead);
-        self.pump_meters(ctx, now);
-        if !self.playback.playing {
-            self.cache_when_idle(ctx, &c, &series, now, input_active, (wa, wb));
-            return;
-        }
-        let fit = self.frames_that_fit(&c, scale);
-        self.start_held_audio(&pass, fit);
-        if self.advance_audio_clock(&pass, step) {
-            return;
-        }
-        self.advance_frame_clock(&pass, step);
-    }
-
-    /// While paused (scrubbing, editing) the viewer's frame comes first: prefetch only a few
-    /// frames, only once it is done, and not while edits keep coming (a layer dragged in the
-    /// viewer): those frames would be stale at the next step and would hold the CPU and GPU
-    /// the next viewer frame needs.
-    fn prefetch_ahead(&mut self, ctx: &egui::Context, now: f64) -> i64 {
-        if self.playback.playing {
-            (self.frames_parallelism() * 2).max(4) as i64
-        } else if self.frames.urgent_pending() {
-            0
-        } else if let Some(wait) = self.editing(now) {
-            ctx.request_repaint_after(std::time::Duration::from_secs_f64(wait));
-            0
-        } else {
-            // Keep workers available for a newly edited viewer frame. Running obsolete
-            // background renders cannot be preempted by the priority queue.
-            self.frames_parallelism().saturating_sub(1).min(2) as i64
-        }
-    }
-
-    /// Cache Before Playback: the range in play order, then start the clock. A range larger than
-    /// the RAM preview budget is cut to the frames that fit (caching more would evict the first
-    /// ones and never finish). Returns true when this pass handled the preview.
-    fn cache_preview(&mut self, pass: &PlaybackPass<'_>) -> bool {
-        let PlaybackPass { ctx, comp, cid, scale, now, frame_rate: fr, series, plan, ahead, mut queued, .. } = *pass;
-        if !self.playback.caching {
-            return false;
-        }
-        let Some(p) = plan else { return false };
-        let mut all = true;
-        let n = (p.end - p.start) / p.step + 1;
-        let fit = self.frames_that_fit(comp, scale);
-        if n > fit {
-            let mut cut = p;
-            (cut.start, cut.end) = (p.first, (p.first + (fit - 1) * p.step).min(p.end));
-            self.playback.plan = Some(cut);
-            self.toast = Some((format!("Preview cut to {fit} of {n} frames: no more fit in the RAM preview (Settings ▸ Memory & CPU)"), now));
-            ctx.request_repaint();
-            return true;
-        }
-        let order: Vec<i64> = (0..n).filter_map(|k| p.frame_after(p.first, k)).collect();
-        for f in order {
-            if self.frames.is_cached(&FrameKey { frame: f, ..series }) {
-                continue;
-            }
-            all = false;
-            if queued < ahead as usize {
-                self.request_frame(cid, f, scale);
-                queued += 1;
-            }
-        }
-        self.playback.waiting = !all;
-        if all {
-            self.playback.caching = false;
-            self.playback.start_wall = now;
-            self.playback.start_frame = p.first;
-            self.session.set_time(fr.tick_of(p.first));
-            self.start_audio(fr.tick_of(p.first));
-        }
-        ctx.request_repaint();
-        true
-    }
-
-    /// Never further ahead than the RAM preview holds: those frames would evict the ones the
-    /// preview shows first, or be evicted before it gets there (#595). The window starts at the
-    /// first uncached frame ahead: after a loop or a restart the frames just ahead are cached,
-    /// and a window from the playhead left the workers idle until it came near the end of the
-    /// cached run. It stays ahead × 3 frames wide: workers spread over the whole preview render
-    /// frames with different layers at once (on the GPU, an atlas each: #1812).
-    fn prefetch_playback(&self, pass: &PlaybackPass<'_>, fit_ahead: i64) {
-        let PlaybackPass { cid, scale, plan, cur, ahead, series, mut queued, video, .. } = *pass;
-        let FrameWindow { first: wa, last: wb } = pass.window;
-        let frame = |k: i64| match plan {
-            Some(p) => p.frame_after(cur, k),
-            None => {
-                let f = cur + k;
-                Some(if f > wb { wa + (f - wb - 1).rem_euclid((wb - wa + 1).max(1)) } else { f })
-            }
-        };
-        let cached = self.frames.cached_frames(&series);
-        let uncached = |f: i64| cached.binary_search(&f).is_err();
-        let first = match plan.filter(|_| self.playback.playing) {
-            Some(p) => (0..fit_ahead.min((p.end - p.start) / p.step.max(1) + 1))
-                .map_while(|k| frame(k).map(|f| (k, f)))
-                .find(|&(_, f)| uncached(f))
-                .map_or(0, |(k, _)| k),
-            None => 0,
-        };
-        for k in first..(first + ahead * 3).min(fit_ahead) {
-            if queued >= ahead as usize || !video {
-                break;
-            }
-            let Some(f) = frame(k) else { break };
-            if uncached(f) {
-                self.request_frame(cid, f, scale);
-                queued += 1;
-            }
-        }
-    }
-
-    /// Advance the audio or scrub output and feed its latest peaks to the level meter; an idle scrub is closed after
-    /// one second. With no source but an active meter, drive the meter to silence and request a repaint.
-    fn pump_meters(&mut self, ctx: &egui::Context, now: f64) {
-        if let Some(a) = &mut self.audio {
-            a.pump();
-            self.meter.update(a.feed.take_peaks(), now);
-        } else if let Some(s) = &mut self.scrub {
-            // Scrubbing: the meters follow the snippets; an idle second closes the output.
-            s.pump();
-            self.meter.update(s.feed.take_peaks(), now);
-            if now - s.last_used > 1.0 {
-                self.scrub = None;
-            }
-            ctx.request_repaint_after(std::time::Duration::from_millis(50));
-        } else if self.meter.active() {
-            self.meter.update([0.0; 2], now);
-            ctx.request_repaint();
-        }
-    }
-
-    /// Held sound starts once the frames ahead are cached (see `Playback::audio_held`): the
-    /// prefetch window when the silent preview keeps real time, else the rest of the preview.
-    fn start_held_audio(&mut self, pass: &PlaybackPass<'_>, fit: i64) {
-        let PlaybackPass { now, plan, series, cur, ahead, frame_rate: fr, .. } = *pass;
-        if !self.playback.audio_held {
-            return;
-        }
-        let Some(p) = plan else { return };
-        if (self.playback.keeps_up(now) && self.cached_ahead(&p, &series, cur, ahead.min(fit))) || self.cached_ahead(&p, &series, cur, fit) {
-            self.playback.audio_held = false;
-            self.playback.start_wall = now;
-            self.playback.start_frame = cur;
-            self.start_audio(fr.tick_of(cur));
-        }
-    }
-
-    /// Audio clock drives playback: show the frame under the audible sample. Returns true when
-    /// the audio path handled this pass (including stopping at the end).
-    fn advance_audio_clock(&mut self, pass: &PlaybackPass<'_>, step: i64) -> bool {
-        let PlaybackPass { ctx, now, series, video, frame_rate: fr, cur, .. } = *pass;
-        let FrameWindow { first: wa, last: wb } = pass.window;
-        let Some(a) = &self.audio else { return false };
-        if a.finished() {
-            if video {
-                self.session.set_time(fr.tick_of(wb));
-            } else {
-                self.playback.audio_frame = Some(wb);
-            }
-            self.stop();
-            return true;
-        }
-        let snap = |f: i64| wa + (f - wa).div_euclid(step) * step;
-        let target = snap(audio::frame_of_sample(a.clock(), a.rate, fr).clamp(wa, wb));
-        if !video {
-            self.playback.audio_frame = Some(target);
-        } else if self.frames.is_cached(&FrameKey { frame: target, ..series }) {
-            self.playback.waiting = false;
-            if target != cur {
-                self.session.set_time(fr.tick_of(target));
-                self.playback.frame_shown(now);
-            }
-        } else {
-            // Rendering can't keep up: rather than skip frames, the sound stops and every
-            // frame shows as it renders until the frames ahead are cached again.
-            self.audio = None;
-            self.playback.audio_held = true;
-            self.playback.waiting = true;
-            // The rate measured before the stall no longer says it keeps up.
-            self.playback.shown_at.clear();
-            self.playback.start_wall = now;
-            self.playback.start_frame = cur;
-        }
-        ctx.request_repaint();
-        true
-    }
-
-    /// The wall clock advances the preview when no audio device drives it, and shows the target
-    /// frame (or holds when it is not cached yet).
-    fn advance_frame_clock(&mut self, pass: &PlaybackPass<'_>, step: i64) {
-        let PlaybackPass { ctx, now, plan, video, looping, frame_rate: fr, cur, series, .. } = *pass;
-        let FrameWindow { first: wa, last: wb } = pass.window;
-        let elapsed = now - self.playback.start_wall;
-        // The plan carries the rate the preview was started with (and `play_with` copies it to
-        // `Playback::fps`). Deriving the frame from the plan keeps a logic-only tick correct even
-        // when a host/test supplies only the plan; a stale duplicate cannot hold playback open.
-        let fps = plan.map_or(self.playback.fps, |p| p.fps);
-        let n = ((elapsed * fps) / step as f64).floor() as i64;
-        let target = match plan {
-            Some(p) => p.frame_after(self.playback.start_frame, n),
-            None => {
-                let t = self.playback.start_frame + n;
-                if t <= wb {
-                    Some(t)
-                } else if looping {
-                    Some(wa + (t - wa).rem_euclid((wb - wa + 1).max(1)))
-                } else {
-                    None
-                }
-            }
-        };
-        let Some(target) = target else {
-            if video {
-                self.session.set_time(fr.tick_of(wb));
-            } else {
-                self.playback.audio_frame = Some(wb);
-            }
-            self.stop();
-            return;
-        };
-        if !video {
-            // Audio-only preview without an audio device: the clock runs, the time stays.
-            self.playback.audio_frame = Some(target);
-            ctx.request_repaint();
-            return;
-        }
-        if self.frames.is_cached(&FrameKey { frame: target, ..series }) {
-            self.playback.waiting = false;
-            if target != cur {
-                self.session.set_time(fr.tick_of(target));
-                self.playback.frame_shown(now);
-            }
-        } else {
-            // Not cached yet: hold the clock at the current frame (cache first, then play).
-            self.playback.waiting = true;
-            let next = plan.and_then(|p| p.frame_after(cur, 1)).unwrap_or(if cur + 1 > wb { wa } else { cur + 1 });
-            if self.frames.is_cached(&FrameKey { frame: next, ..series }) {
-                self.session.set_time(fr.tick_of(next));
-            }
-            self.playback.start_wall = now;
-            self.playback.start_frame = fr.frame_at(self.session.time());
-        }
-        ctx.request_repaint();
-    }
-
-    /// While the project keeps changing (an edit within [`EDIT_QUIET`] seconds), how long until
-    /// it counts as settled.
-    fn editing(&mut self, now: f64) -> Option<f64> {
-        if self.last_edit.1 != self.session.revision {
-            self.last_edit = (now, self.session.revision);
-        }
-        let left = EDIT_QUIET - (now - self.last_edit.0);
-        (left > 0.0).then_some(left)
-    }
-
-    /// Composition ▸ Preview ▸ Cache Frames When Idle: after a second without input or edits,
-    /// render the work area's frames (from the current time on, then from its start) in the
-    /// background, a few at a time, until it is cached or the RAM preview budget is full.
-    fn cache_when_idle(
-        &mut self,
-        ctx: &egui::Context,
-        comp: &effectcraft_engine::project::Comp,
-        series: &FrameKey,
-        now: f64,
-        input_active: bool,
-        (wa, wb): (i64, i64),
-    ) {
-        let active = input_active;
-        if active || self.last_activity.1 != self.session.revision {
-            self.last_activity = (now, self.session.revision);
-        }
-        if !self.ui.cache_when_idle || self.frames.urgent_pending() {
-            return;
-        }
-        let quiet = now - self.last_activity.0;
-        if quiet < 1.0 {
-            ctx.request_repaint_after(std::time::Duration::from_secs_f64(1.0 - quiet));
-            return;
-        }
-        // An empty work area has nothing to cache.
-        let n = wb - wa + 1;
-        if n < 1 {
-            return;
-        }
-        let cur = comp.frame_rate.frame_at(self.session.time()).clamp(wa, wb);
-        let fit = self.frames_that_fit(comp, series.scale as f64 / 1000.0).min(n);
-        let slots = (self.frames_parallelism() / 2).max(1);
-        let mut queued = self.frames.inflight();
-        let scale = series.scale as f64 / 1000.0;
-        let mut pending = false;
-        for k in 0..fit {
-            let f = wa + (cur - wa + k).rem_euclid(n);
-            if self.frames.is_cached(&FrameKey { frame: f, ..*series }) {
-                continue;
-            }
-            pending = true;
-            if queued >= slots {
-                break;
-            }
-            self.request_frame(ItemId(series.comp), f, scale);
-            queued += 1;
-        }
-        if pending {
-            ctx.request_repaint_after(std::time::Duration::from_millis(100));
-        }
-    }
-
-    /// How many viewer frames of `comp` at `scale` the RAM preview budget holds (90 % of it,
-    /// at least one).
-    /// The frames of `plan` from `cur` to its end, or as many as fit in the RAM preview, are
-    /// cached: sound can play from `cur` in real time.
-    fn cached_ahead(&self, plan: &effectcraft_engine::preview::PreviewPlan, series: &FrameKey, cur: i64, fit: i64) -> bool {
-        let cached = self.frames.cached_frames(series);
-        (0..fit).map_while(|k| plan.frame_after(cur, k)).take_while(|f| *f >= cur).all(|f| cached.binary_search(&f).is_ok())
-    }
-
-    fn frames_that_fit(&self, comp: &effectcraft_engine::project::Comp, scale: f64) -> i64 {
-        let side = |n: u32| (n as f64 * scale).ceil().max(1.0);
-        let frame = side(comp.width) * side(comp.height) * 4.0;
-        ((self.frames.budget() as f64 * 0.9 / frame) as i64).max(1)
-    }
-
-    fn frames_parallelism(&self) -> usize {
-        if cfg!(target_arch = "wasm32") {
-            // frame workers render one frame each; without them frames render one at a time
-            // on the UI thread (`Frames::pump`)
-            return self.frames.remote_slots().max(1);
-        }
-        self.frames.parallelism()
-    }
-
-    // ---------------------------------------------------------------- control channel
-
-    pub(crate) fn raise_for_control(&mut self, ctx: &egui::Context) {
-        ctx.request_repaint();
-    }
-
-    /// Handle the control channel for this tick: drain queued requests plus previously deferred ones, run each
-    /// through `control::handle`, answer `Done` immediately, retry `Retry` until its three-second deadline, hold
-    /// input/job/screenshot replies until their event happens and finish job waiters. Retry timeouts and refused
-    /// screenshots are answered as `{"ok": false, "error": ...}`; the receiver is kept for the next tick.
-    fn drain_control(&mut self, ctx: &egui::Context, now: f64) {
-        let Some(rx) = self.control_rx.take() else { return };
-        let mut reqs: Vec<(ControlRequest, f64)> = std::mem::take(&mut self.deferred);
-        while let Ok(req) = rx.try_recv() {
-            reqs.push((req, now + 3.0));
-        }
-        for (req, deadline) in reqs {
-            let reply = req.reply.clone();
-            match control::handle(self, ctx, &req, now) {
-                control::Outcome::Done(v) => {
-                    let _ = reply.send(v);
-                }
-                control::Outcome::Retry(msg) => {
-                    if now < deadline {
-                        self.deferred.push((req, deadline));
-                        ctx.request_repaint();
-                    } else {
-                        let _ = reply.send(json!({"ok": false, "error": msg}));
-                    }
-                }
-                control::Outcome::AfterInput => {
-                    self.input_waiters.push(reply);
-                    // The reply waits for a real UI pass: a hidden window must run one.
-                    self.want_paint = true;
-                }
-                control::Outcome::AwaitJobs(w) => {
-                    self.job_waiters.push((w, reply));
-                    ctx.request_repaint();
-                }
-                control::Outcome::Screenshot { path, target } => {
-                    // A covered or minimized window presents no frames (macOS skips its redraws), so
-                    // a screenshot would never arrive and nothing would tick its timeout. The
-                    // hidden-window capture path (a pending screenshot forces a pass in 0.37) needs
-                    // a native platform run before this gate is removed; the web build never paints
-                    // a hidden tab.
-                    if ctx.input(|i| i.viewport().occluded == Some(true) || i.viewport().minimized == Some(true)) {
-                        let _ = reply.send(json!({"ok": false, "error": "window is covered or minimized: call ui.focus first (render.frame renders comp pixels without the window)"}));
-                        continue;
-                    }
-                    self.admit_screenshot(ctx, path, target, reply);
-                }
-            }
-        }
-        self.control_rx = Some(rx);
-        self.finish_job_waiters(ctx);
-    }
-
-    /// Reply to the control requests whose offloaded jobs ended.
-    fn finish_job_waiters(&mut self, ctx: &egui::Context) {
-        if self.job_waiters.is_empty() {
-            return;
-        }
-        self.session.poll_render();
-        self.session.poll_offload();
-        let waiters = std::mem::take(&mut self.job_waiters);
-        for (w, reply) in waiters {
-            if w.pending(self) {
-                self.job_waiters.push((w, reply));
-            } else {
-                let v = w.finish(self);
-                let _ = reply.send(v);
-            }
-        }
-        if !self.job_waiters.is_empty() {
-            ctx.request_repaint_after(std::time::Duration::from_millis(50));
-        }
-    }
-
-    // ---------------------------------------------------------------- screenshots
-
-    /// The root surface geometry a screenshot is admitted against.
-    ///
-    /// The last completed pass's geometry is authoritative. Before any pass, only the viewport's
-    /// `inner_rect` (the client surface a capture returns) is accepted: `outer_rect` also covers
-    /// the title bar and window frame, so a capture issued against it would be cropped and
-    /// validated against a different rectangle than the callback delivers. A request that arrives
-    /// before the geometry is known is refused with an actionable error, and the pass that would
-    /// establish it is requested.
-    fn current_geometry(&self, ctx: &egui::Context) -> Option<DrawGeometry> {
-        if let Some(g) = self.draw_geom {
-            return Some(g);
-        }
-        let rect = ctx.input(|i| i.viewport().inner_rect)?;
-        (rect.width() > 0.0 && rect.height() > 0.0).then_some(DrawGeometry { rect, ppp: ctx.pixels_per_point(), epoch: self.geometry_epoch })
-    }
-
-    /// The point rectangle a request captures: its crop, clamped to the window, or all of it.
-    fn shot_target_rect(geom: &DrawGeometry, crop: Option<[f32; 4]>) -> Option<egui::Rect> {
-        let r = match crop {
-            Some([x, y, w, h]) if [x, y, w, h].iter().all(|v| v.is_finite()) => {
-                egui::Rect::from_min_size(geom.rect.min + egui::vec2(x, y), egui::vec2(w.max(0.0), h.max(0.0))).intersect(geom.rect)
-            }
-            Some(_) => return None,
-            None => geom.rect,
-        };
-        (r.width() > 0.0 && r.height() > 0.0).then_some(r)
-    }
-
-    /// The screen-point crop `target` names right now (a panel's or element's current rectangle),
-    /// or an actionable error when it is not on screen. Resolved at issuance, never stored from
-    /// admission: the UI may move while it settles.
-    fn shot_crop(&self, target: &ShotTarget, geom: &DrawGeometry) -> Result<Option<egui::Rect>, String> {
-        let crop = match target {
-            ShotTarget::Window => None,
-            ShotTarget::Rect(r) => Some(*r),
-            ShotTarget::Panel(p) => {
-                let id = format!("panel.{}", p.id());
-                let found = self.auto.find(&id).ok_or_else(|| format!("the {} panel is not on screen", p.title()))?;
-                Some(found.rect)
-            }
-            ShotTarget::Id(id) => Some(self.auto.find(id).ok_or_else(|| format!("no element `{id}` is on screen"))?.rect),
-        };
-        Self::shot_target_rect(geom, crop).map(Some).ok_or_else(|| "the screenshot area is empty or not a finite rectangle".to_string())
-    }
-
-    /// `target` as a crop relative to `geom`'s origin: what the image's own pixels are cut with.
-    fn shot_relative_crop(&self, target: &ShotTarget, geom: &DrawGeometry) -> Result<Option<[f32; 4]>, String> {
-        let Some(r) = self.shot_crop(target, geom)? else { return Ok(None) };
-        Ok(Some([r.min.x - geom.rect.min.x, r.min.y - geom.rect.min.y, r.width(), r.height()]))
-    }
-
-    /// Pixel bytes `rect` takes at `ppp`, checked (`width * height * 4`).
-    fn shot_pixel_bytes(rect: egui::Rect, ppp: f32) -> Option<usize> {
-        if !ppp.is_finite() || ppp <= 0.0 {
-            return None;
-        }
-        let w = (rect.width() as f64 * ppp as f64).ceil().max(1.0) as usize;
-        let h = (rect.height() as f64 * ppp as f64).ceil().max(1.0) as usize;
-        w.checked_mul(h)?.checked_mul(4)
-    }
-
-    /// Reserve and queue one `ui.screenshot`, or reply with an actionable error.
-    fn admit_screenshot(&mut self, ctx: &egui::Context, path: Option<String>, target: ShotTarget, reply: Sender<serde_json::Value>) {
-        let Some(geom) = self.current_geometry(ctx) else {
-            let _ = reply.send(
-                json!({"ok": false, "error": "the window geometry is not known yet (it is recorded by a completed UI pass; retry after the next frame)"}),
-            );
-            // Ask for the pass that records it.
-            self.want_paint = true;
-            ctx.request_repaint();
-            return;
-        };
-        if self.pending_screenshots.len() >= MAX_PENDING_SHOTS {
-            let _ = reply.send(json!({"ok": false, "error": format!("too many screenshots are pending (at most {MAX_PENDING_SHOTS})")}));
-            return;
-        }
-        if let Err(e) = self.shot_crop(&target, &geom) {
-            let _ = reply.send(json!({"ok": false, "error": e}));
-            return;
-        }
-        // The capture is always the whole surface (the crop is applied when the PNG is written),
-        // so the reservation and the per-image bound follow the surface's actual dimensions.
-        let Some(bytes) = Self::shot_pixel_bytes(geom.rect, geom.ppp) else {
-            let _ = reply.send(json!({"ok": false, "error": "the screenshot area is too large to reserve"}));
-            return;
-        };
-        if bytes > MAX_SHOT_BYTES {
-            let _ = reply
-                .send(json!({"ok": false, "error": format!("the screenshot would need about {bytes} bytes, over the {MAX_SHOT_BYTES}-byte per-image limit")}));
-            return;
-        }
-        if self.shot_bytes.checked_add(bytes).is_none_or(|n| n > MAX_SHOT_TOTAL_BYTES) {
-            let _ = reply.send(json!({"ok": false, "error": format!("the screenshot would exceed the {MAX_SHOT_TOTAL_BYTES}-byte pending-image budget")}));
-            return;
-        }
-        self.shot_bytes += bytes;
-        self.pending_screenshots.push(PendingShot {
-            path,
-            target,
-            crop: None,
-            reply,
-            deadline: self.now + SCREENSHOT_TIMEOUT_S,
-            settle_at: self.now + SCREENSHOT_SETTLE_S,
-            admitted: geom,
-            admitted_pass: self.ui_pass_seq,
-            issued: None,
-            slot: None,
-            reserved_bytes: bytes,
-            attempts: 0,
-        });
-        // A queued capture needs a settled UI pass before it can be issued.
-        self.want_paint = true;
-    }
-
-    /// Re-reserve request `i` against `geom` after a surface change; false when it no longer fits.
-    fn refresh_shot_reservation(&mut self, i: usize, geom: &DrawGeometry) -> bool {
-        let Some(bytes) = Self::shot_pixel_bytes(geom.rect, geom.ppp) else { return false };
-        if bytes > MAX_SHOT_BYTES {
-            return false;
-        }
-        let released = self.shot_bytes.saturating_sub(self.pending_screenshots[i].reserved_bytes);
-        if released.checked_add(bytes).is_none_or(|n| n > MAX_SHOT_TOTAL_BYTES) {
-            return false;
-        }
-        self.shot_bytes = released + bytes;
-        self.pending_screenshots[i].reserved_bytes = bytes;
-        true
-    }
-
-    /// Reply with an error to request `i` and release its reservation.
-    fn fail_shot(&mut self, i: usize, message: impl Into<String>) {
-        let shot = self.pending_screenshots.remove(i);
-        self.shot_bytes = self.shot_bytes.saturating_sub(shot.reserved_bytes);
-        let _ = shot.reply.send(json!({"ok": false, "error": message.into()}));
-    }
-
-    /// Collect completed captures, enforce timeouts and issue every settled request.
-    ///
-    /// Runs from [`Self::tick`] only: the callback stores pixels in its slot and wakes the
-    /// viewport, and everything that can write a file or reply happens here, on the app thread.
-    fn tick_screenshots(&mut self, ctx: &egui::Context) {
-        let Some(geom) = self.current_geometry(ctx) else { return };
-        self.drain_completed_screenshots(geom);
-        self.timeout_screenshots();
-        self.issue_screenshots(ctx, geom);
-        // 4. Wake up for the earliest deadline even when no further pass is otherwise needed: an
-        //    issued capture whose callback never arrives (hidden window, display asleep, renderer
-        //    failure) would otherwise never reach its timeout. This is a timer, not a paint
-        //    request: the issued screenshot command already forces the frame it needs.
-        if let Some(next) = self.pending_screenshots.iter().map(|s| s.deadline).reduce(f64::min) {
-            let wait = (next - self.now).max(0.001);
-            ctx.request_repaint_after(std::time::Duration::from_secs_f64(wait));
-        }
-    }
-
-    /// 1. Drain completed slots. A completion whose surface epoch changed since issuance is
-    ///    discarded even if the geometry changed back: it was cropped with another frame's
-    ///    pixels-per-point.
-    fn drain_completed_screenshots(&mut self, geom: DrawGeometry) {
-        let mut i = 0;
-        while i < self.pending_screenshots.len() {
-            let taken = self.pending_screenshots.get(i).and_then(|s| s.slot.as_ref()).and_then(craft_ui::capture::CaptureSlot::take);
-            let Some(result) = taken else {
-                i += 1;
-                continue;
-            };
-            let issued = self.pending_screenshots[i].issued;
-            match result {
-                Ok(image) => {
-                    if issued.is_none_or(|g| g.epoch != geom.epoch) {
-                        self.pending_screenshots[i].slot = None;
-                        self.pending_screenshots[i].issued = None;
-                        if self.pending_screenshots[i].attempts >= SCREENSHOT_MAX_RETRIES {
-                            self.fail_shot(i, "the window resized while the screenshot was being taken");
-                        } else if !self.refresh_shot_reservation(i, &geom) {
-                            self.fail_shot(i, "the resized window is too large to capture within the screenshot budget");
-                        } else {
-                            let settle_at = self.now + SCREENSHOT_SETTLE_S;
-                            let passes = self.ui_pass_seq;
-                            let s = &mut self.pending_screenshots[i];
-                            s.attempts += 1;
-                            s.admitted = geom;
-                            s.admitted_pass = passes;
-                            s.settle_at = settle_at;
-                            i += 1;
-                        }
-                        continue;
-                    }
-                    let Some(issued) = issued else {
-                        i += 1;
-                        continue;
-                    };
-                    if !shot_image_matches(&image, issued.rect, issued.ppp) {
-                        self.fail_shot(i, "the screenshot's pixels do not match the window it was taken from");
-                        continue;
-                    }
-                    // The returned image can be smaller than requested (the E2 adapter-limit fit),
-                    // so the crop uses the image's own scale, never the issued ppp.
-                    let [iw, ih] = image.size;
-                    let (sx, sy) = (iw as f64 / issued.rect.width() as f64, ih as f64 / issued.rect.height() as f64);
-                    if !(sx.is_finite() && sx > 0.0 && sy.is_finite() && sy > 0.0) {
-                        self.fail_shot(i, "the screenshot's size does not describe the window it was taken from");
-                        continue;
-                    }
-                    let shot = self.pending_screenshots.remove(i);
-                    self.shot_bytes = self.shot_bytes.saturating_sub(shot.reserved_bytes);
-                    let r = control::save_screenshot(&image, shot.path.as_deref(), shot.crop, [sx, sy]);
-                    let _ = shot.reply.send(r);
-                }
-                Err(e) => {
-                    self.fail_shot(i, e.to_string());
-                }
-            }
-        }
-    }
-
-    /// 2. Timeouts: a late callback finds its slot cancelled and writes nothing.
-    fn timeout_screenshots(&mut self) {
-        let mut i = 0;
-        while i < self.pending_screenshots.len() {
-            if self.now > self.pending_screenshots[i].deadline {
-                self.fail_shot(i, "no frame was presented (window hidden or display asleep)");
-            } else {
-                i += 1;
-            }
-        }
-    }
-
-    /// 3. Issue settled requests. The command itself requests the paint; a request still
-    ///    waiting for its passes needs `want_paint` so a hidden window keeps painting.
-    fn issue_screenshots(&mut self, ctx: &egui::Context, geom: DrawGeometry) {
-        let mut i = 0;
-        while i < self.pending_screenshots.len() {
-            if self.pending_screenshots[i].slot.is_some() {
-                i += 1;
-                continue;
-            }
-            if geom.epoch != self.pending_screenshots[i].admitted.epoch {
-                if self.pending_screenshots[i].attempts >= SCREENSHOT_MAX_RETRIES {
-                    self.fail_shot(i, "the window kept resizing before the screenshot could be taken");
-                    continue;
-                }
-                if !self.refresh_shot_reservation(i, &geom) {
-                    self.fail_shot(i, "the resized window is too large to capture within the screenshot budget");
-                    continue;
-                }
-                let (now, passes) = (self.now, self.ui_pass_seq);
-                let s = &mut self.pending_screenshots[i];
-                s.attempts += 1;
-                s.admitted = geom;
-                s.admitted_pass = passes;
-                s.settle_at = now + SCREENSHOT_SETTLE_S;
-                self.want_paint = true;
-                i += 1;
-                continue;
-            }
-            let settled = self.ui_pass_seq >= self.pending_screenshots[i].admitted_pass.saturating_add(SCREENSHOT_SETTLE_PASSES)
-                && self.now >= self.pending_screenshots[i].settle_at;
-            if !settled {
-                self.want_paint = true;
-                i += 1;
-                continue;
-            }
-            // Resolve the crop now, against the settled UI: an element that moved since admission
-            // is captured where it is, and its rectangle is relative to this issued surface.
-            let target = self.pending_screenshots[i].target.clone();
-            let crop = match self.shot_relative_crop(&target, &geom) {
-                Ok(c) => c,
-                Err(e) => {
-                    self.fail_shot(i, e);
-                    continue;
-                }
-            };
-            let (slot, callback) = craft_ui::capture::CaptureSlot::new(ctx, egui::ViewportId::ROOT, MAX_SHOT_BYTES);
-            ctx.send_viewport_cmd(egui::ViewportCommand::Screenshot(callback));
-            let s = &mut self.pending_screenshots[i];
-            s.slot = Some(slot);
-            s.issued = Some(geom);
-            s.crop = crop;
-            i += 1;
-        }
-    }
-
-    // ---------------------------------------------------------------- frame
-
-    /// Apply the engine events drained this tick: open a comp, show a toast, open a URL, run a frontend command,
-    /// purge frame caches or copy an image; command and clipboard failures go to `app.ui.status`.
-    fn handle_events(&mut self, ctx: &egui::Context) {
-        for ev in self.session.drain_events() {
-            match ev {
-                effectcraft_engine::Event::OpenComp(c) => {
-                    panels::viewers::on_open_comp(self, c);
-                    self.ui.timeline.pps = None;
-                }
-                effectcraft_engine::Event::Toast { message, .. } => self.toast = Some((message, self.now)),
-                effectcraft_engine::Event::OpenUrl(url) => ctx.open_url(egui::OpenUrl::new_tab(url)),
-                // Frames are keyed by content: an edit keeps those of comps it doesn't touch.
-                effectcraft_engine::Event::ProjectChanged { .. } => {}
-                effectcraft_engine::Event::Frontend { command, params } => {
-                    if let Err(e) = crate::menus::frontend(self, ctx, &command, params) {
-                        self.ui.status = e;
-                    }
-                }
-                effectcraft_engine::Event::PurgeCaches => self.frames.clear(),
-                effectcraft_engine::Event::CopyImage { width, height, rgba } => {
-                    if let Err(e) = copy_image(ctx, width, height, &rgba) {
-                        self.ui.status = e;
-                    }
-                }
-            }
-        }
-    }
-
-    /// The app's only non-paint entry: one tick of background work.
-    ///
-    /// This runs for every eframe logic callback, including the logic-only ticks of a hidden
-    /// window (which never reach [`Self::draw`]). It must therefore do no input handling, no
-    /// layout and no presentation: engine/job queues, autosave, playback, audio, the control
-    /// channel, screenshots and the close guard. Everything here is idempotent for a pass that
-    /// `Context::request_discard` replays.
-    pub fn tick(&mut self, ctx: &egui::Context, frame: &eframe::Frame) {
-        self.now = self.clock.now();
-        // The compositor exists before the first paint and while hidden (device-loss handling
-        // must run there too).
-        self.init_gpu(frame);
-        self.apply_gpu_failure(ctx);
-        if self.gpu_failure_applied == Some(true) {
-            self.close_after_device_loss(ctx);
-            return;
-        }
-        // Focus comes from the fresh viewport copy; a full pass's `InputState::focused` is only a
-        // fallback (a logic-only tick leaves it at the previous pass's value).
-        let focused = ctx.input(|i| i.viewport().focused.or(Some(i.focused)));
-        self.focused = focused.unwrap_or(self.focused);
-        // The interface language's fallback fonts are installed in `draw` (fonts need a pass), but
-        // commands handled here use the right catalog already.
-        let language = crate::i18n::language(self);
-        crate::i18n::set_current(language);
-        if self.styled_language != language {
-            self.want_paint = true;
-        }
-        // Frames and worker completions wake the app even while it is hidden.
-        self.frames.set_context(ctx);
-        updates_ui::tick(self, ctx);
-        if self.session.render_job.is_some() {
-            self.session.poll_render();
-            ctx.request_repaint_after(std::time::Duration::from_millis(100));
-        }
-        if self.session.track_job.is_some() {
-            self.session.poll_track();
-            ctx.request_repaint_after(std::time::Duration::from_millis(50));
-        }
-        if self.session.mask_job.is_some() {
-            self.session.poll_mask_track();
-            ctx.request_repaint_after(std::time::Duration::from_millis(50));
-        }
-        // Background tasks (Content-Aware Fill, Scene Edit Detection, imports).
-        if !self.session.tasks.is_empty() {
-            self.session.poll_jobs();
-            ctx.request_repaint_after(std::time::Duration::from_millis(100));
-        }
-        // Analyses running in a worker (the web app).
-        if !self.session.offloaded.is_empty() {
-            self.session.poll_offload();
-            ctx.request_repaint_after(std::time::Duration::from_millis(100));
-        }
-        // Warp Stabilizer: finish analyses and start queued (re-)analyses in the background.
-        if self.session.warp_job.is_some() || !self.session.warp_pending.is_empty() {
-            self.session.poll_warp(true);
-            self.session.poll_roto(true);
-            ctx.request_repaint_after(std::time::Duration::from_millis(100));
-        }
-        // Roto Brush propagation and Object Matte tracking / Freeze: finish jobs (a Freeze writes
-        // its mattes) and start queued ones in the background.
-        if self.session.roto_job.is_some() || !self.session.roto_pending.is_empty() {
-            self.session.poll_roto(true);
-            ctx.request_repaint_after(std::time::Duration::from_millis(100));
-        }
-        // 3D Camera Tracker: likewise (tracking, then solving).
-        if self.session.camera_job.is_some() || !self.session.camera_pending.is_empty() {
-            self.session.poll_camera(true);
-            ctx.request_repaint_after(std::time::Duration::from_millis(100));
-        }
-        self.run_script_tasks(ctx);
-        self.run_dialog_answers();
-        self.handle_events(ctx);
-        if let Some(rx) = self.command_inbox.take() {
-            while let Ok(id) = rx.try_recv() {
-                if let Err(e) = menus::invoke(self, ctx, &id, json!({})) {
-                    self.ui.status = e;
-                }
-            }
-            self.command_inbox = Some(rx);
-        }
-        // A close request (the window's button, Quit, `app.quit`) must be answered while hidden.
-        panels::unsaved::on_close_requested(self, ctx);
-        let title = panels::unsaved::window_title(self);
-        if title != self.window_title {
-            ctx.send_viewport_cmd(egui::ViewportCommand::Title(title.clone()));
-            self.window_title = title;
-        }
-        self.tick_autosave(ctx);
-        self.tick_workspace_autosave(ctx);
-        let now = self.now;
-        prefs_live::tick(self, ctx, now);
-        // Playback advances without a paint (its frames and the audio clock are background work).
-        // Idle prefetch keeps its old condition: it only runs once a viewer has drawn.
-        if (self.playback.playing || self.last_viewer_scale.is_some())
-            && let Some(cid) = self.session.active_comp_id()
-        {
-            let (scale, active) = (self.last_viewer_scale.unwrap_or(1.0), self.input_active);
-            self.advance_playback(ctx, scale, now, active, cid);
-        }
-        self.drain_control(ctx, now);
-        // Screenshot completion, deadlines and issuance are app-side work: the callback only
-        // stores pixels and wakes this viewport.
-        self.tick_screenshots(ctx);
-        // Time-based FPS readout over UI passes (a hidden logic-only tick is not a frame).
-        let dt = (now - self.last_time) as f32;
-        if dt > 0.0 && dt < 2.0 {
-            self.fps = self.fps * 0.9 + (1.0 / dt).min(480.0) * 0.1;
-        }
-        self.last_time = now;
-        // A hidden window paints when work needs a UI pass: queued input and waits, a settled
-        // screenshot, or playback into a child viewport.
-        let focused = self.focused;
-        let child_viewports = !self.ui.dock.layout.floating.is_empty() || prefs_live::video_preview_active(self, focused);
-        let paint = self.want_paint
-            || !self.synthetic.is_empty()
-            || !self.input_waiters.is_empty()
-            || self.pending_screenshots.iter().any(|s| s.slot.is_none())
-            || (self.playback.playing && child_viewports);
-        if paint {
-            self.request_hidden_paint(ctx);
-        }
-    }
-
-    /// Ask the host for a UI pass even when the window is minimized or occluded.
-    ///
-    /// Native eframe honours `RequestPaintWhileHidden`; the shared web backend does not carry it
-    /// yet (a browser does not paint a hidden tab), so the web build only requests a normal
-    /// repaint and hidden web screenshots/input remain unqualified.
-    fn request_hidden_paint(&mut self, ctx: &egui::Context) {
-        self.want_paint = false;
-        #[cfg(not(target_arch = "wasm32"))]
-        ctx.send_viewport_cmd(egui::ViewportCommand::RequestPaintWhileHidden);
-        ctx.request_repaint();
-    }
-
-    /// Install the theme and fonts for the current language. Fonts need a real pass: the pass
-    /// that installs them draws nothing, and the next pass draws with them (the two-pass warm-up
-    /// the app has always had). Never call this from a logic-only tick.
-    fn ui_setup(&mut self, ctx: &egui::Context) {
-        panels::viewer_text::install_hooks(ctx);
-        let language = crate::i18n::language(self);
-        crate::i18n::set_current(language);
-        if (!self.styled || self.styled_language != language) && self.synthetic_in_flight {
-            // The install needs a pass that draws nothing, but this pass has already applied a
-            // synthetic batch: defer the theme/font install by one pass instead of dropping the
-            // input (feeds are only put into a pass that can draw).
-            ctx.request_repaint();
-            return;
-        }
-        if !self.styled || self.styled_language != language {
-            theme::install(ctx, &self.tokens, language);
-            self.styled_language = language;
-            if !self.styled {
-                fit_window(ctx);
-                self.styled = true;
-            }
-            self.fonts_ready = false;
-            ctx.request_repaint();
-        } else if !self.fonts_ready {
-            // The pass after the install draws: egui has the new font definitions by now.
-            self.fonts_ready = true;
-            ctx.request_repaint();
-        }
-    }
-
-    /// One UI pass: setup, input-driven shortcuts, layout and painting. Called from
-    /// `eframe::App::ui` and by tests with the root `Ui`.
-    pub fn draw(&mut self, ui: &mut egui::Ui, frame: &eframe::Frame) {
-        panels::viewer_text::begin_ui(ui.ctx());
-        self.draw_inner(ui, frame);
-        // All exits, including fonts/device loss, observe this pass's real custom availability.
-        panels::viewer_text::finish_ime(self, ui);
-    }
-
-    /// Context creators install these hooks before the first full pass.
-    pub fn install_ime_reset_hooks(ctx: &egui::Context) {
-        panels::viewer_text::install_hooks(ctx);
-    }
-
-    /// Host wrappers call this after their last logic mutation, without replaying UI events.
-    pub fn finish_ime_logic(&self, ctx: &egui::Context) {
-        panels::viewer_text::finish_logic(self, ctx);
-    }
-
-    /// One UI pass after the IME begin hook: close on an applied GPU failure, run `ui_setup`, skip drawing until
-    /// fonts are ready, draw the frame, finish pointer wrapping, pump queued wasm frames, record input activity,
-    /// publish the completed pass's geometry and pass sequence, acknowledge applied synthetic input and answer
-    /// `AfterInput` replies only after a non-discarded pass. Requests repaints while frames are in flight.
-    fn draw_inner(&mut self, ui: &mut egui::Ui, frame: &eframe::Frame) {
-        let ctx = ui.ctx().clone();
-        if self.gpu_failure_applied == Some(true) {
-            self.close_after_device_loss(&ctx);
-            return;
-        }
-        self.ui_setup(&ctx);
-        if !self.fonts_ready {
-            // A pass that installs fonts draws nothing. No synthetic batch is in flight here (the
-            // hook feeds input only to a ready app), and events egui already applied are never
-            // fed again: that would double the pointer/key state of one click.
-            ctx.request_repaint();
-            return;
-        }
-        self.frame(ui);
-        #[cfg(not(target_arch = "wasm32"))]
-        pointer_wrap::finish_native(&ctx, frame);
-        // wasm32: no frame threads; render queued frames now, between UI frames.
-        if cfg!(target_arch = "wasm32") && self.frames.pump(std::time::Duration::from_millis(if self.playback.playing { 24 } else { 40 })) {
-            ctx.request_repaint();
-        }
-        // Input belongs to this known UI phase: record it for the next tick.
-        let active = ctx.input(|i| !i.events.is_empty() || i.pointer.any_down() || i.pointer.is_moving());
-        self.input_active = active;
-        self.last_pointer_down = ctx.input(|i| i.pointer.any_down());
-        // Geometry of a completed pass (a discarded pass is laid out again; only the final one
-        // describes the surface the next capture will see). Window position is irrelevant.
-        if !ctx.will_discard() {
-            let rect = ctx.content_rect();
-            let ppp = ctx.pixels_per_point();
-            let changed = self.draw_geom.is_none_or(|g| g.rect.size() != rect.size() || g.ppp != ppp);
-            if changed {
-                self.geometry_epoch = self.geometry_epoch.wrapping_add(1);
-            }
-            self.draw_geom = Some(DrawGeometry { rect, ppp, epoch: self.geometry_epoch });
-            self.ui_pass_seq = self.ui_pass_seq.saturating_add(1);
-        }
-        // A batch is acknowledged once a UI pass applied it, even if layout was later discarded.
-        self.mark_synthetic_applied();
-        // `AfterInput` replies wait for the final (non-discarded) pass that applied the last
-        // synthetic event: a hidden request is answered only after its forced pass, and a pass
-        // egui throws away cannot produce an early success reply.
-        if !ctx.will_discard() && self.synthetic.is_empty() {
-            for w in self.input_waiters.drain(..) {
-                let _ = w.send(json!({"ok": true, "result": null}));
-            }
-        } else if !self.input_waiters.is_empty() {
-            self.want_paint = true;
-            ctx.request_repaint();
-        }
-        if self.frames.inflight() > 0 {
-            ctx.request_repaint_after(std::time::Duration::from_millis(30));
-        }
-    }
-
-    /// The panels, menus, dialogs and overlays of one pass.
-    fn frame(&mut self, ui: &mut egui::Ui) {
-        let ctx = ui.ctx().clone();
-        // Only a viewer that draws in *this* pass records a scale: a closed viewer, the Home
-        // screen or another comp must stop idle prefetch at a stale scale.
-        self.last_viewer_scale = None;
-        self.apply_prefs(&ctx);
-        // Video Preview is a second viewport: only a real pass can update it.
-        prefs_live::frame(self, &ctx);
-        self.auto.begin_frame();
-        let tab_had_widget_focus = ctx.egui_wants_keyboard_input();
-        menus::handle_shortcuts(self, &ctx);
-        if !ctx.input(|i| i.pointer.primary_down()) {
-            self.ui.viewer.property_interacting = false;
-        }
-        let t = self.tokens;
-        let full = ui.max_rect();
-        if self.dialog.is_some() {
-            ui.disable();
-        }
-        ui.painter().rect_filled(full, 0.0, t.app_bg);
-        let mut top = full.min.y;
-        if self.ui.show_menu_bar {
-            let mb = egui::Rect::from_min_size(full.min, egui::vec2(full.width(), 24.0));
-            let mut child = ui.new_child(egui::UiBuilder::new().max_rect(mb));
-            child.painter().rect_filled(mb, 0.0, t.header_bg);
-            menus::menu_bar(self, &mut child);
-            top = mb.max.y;
-        }
-        let header_h = 40.0;
-        let header = egui::Rect::from_min_size(egui::pos2(full.min.x, top), egui::vec2(full.width(), header_h));
-        header::show(self, ui, header);
-        let body = egui::Rect::from_min_max(egui::pos2(full.min.x + 4.0, header.max.y + 2.0), egui::pos2(full.max.x - 4.0, full.max.y - 4.0));
-        self.dock_area(ui, body);
-        #[cfg(not(target_arch = "wasm32"))]
-        prefs_live::dropped_files(self, ui, full);
-        if !tab_had_widget_focus {
-            menus::handle_tab_shortcut(self, &ctx);
-        }
-        panels::precomp::mini_flowchart(self, &ctx);
-        panels::home::capture_thumbnail(self);
-        panels::dialogs::show(self, &ctx);
-        updates_ui::show(self, &ctx);
-        panels::scriptui_view::sync_panels(self);
-        panels::scriptui_view::show_windows(self, &ctx);
-        panels::learn::coach(self, &ctx);
-        let lift = panels::media_panels::import_card(self, ui, full);
-        self.draw_toast(ui, full, lift);
-    }
-
-    /// Workspace-layout auto-save: a background write that also runs while hidden, once the
-    /// pointer has lifted.
-    fn tick_workspace_autosave(&mut self, ctx: &egui::Context) {
-        if self.session.config.is_none() || !self.workspace_store.has_changes(&self.ui) || self.last_pointer_down {
-            return;
-        }
-        if self.workspace_store.due(self.now) {
-            self.save_workspace_state();
-        }
-        if self.workspace_store.has_changes(&self.ui) {
-            ctx.request_repaint_after(std::time::Duration::from_secs(1));
-        }
-    }
-
-    fn save_workspace_state(&mut self) {
-        if let Err(error) = self.workspace_store.save(self.session.config.as_deref(), &self.ui) {
-            if self.workspace_store.error.as_ref() != Some(&error) {
-                log::warn!("{error}");
-                self.ui.status = error.clone();
-            }
-            self.workspace_store.error = Some(error);
-        }
-    }
-
-    /// The status message or the latest toast, bottom left (`lift` points higher while the
-    /// Importing card is there).
-    fn draw_toast(&mut self, ui: &mut egui::Ui, full: egui::Rect, lift: f32) {
-        let now = self.now;
-        let msg = if !self.ui.status.is_empty() {
-            Some(self.ui.status.clone())
-        } else {
-            self.toast.as_ref().filter(|(_, at)| now - at < 4.0).map(|(m, _)| m.clone())
-        };
-        if let Some(m) = msg {
-            let t = &self.tokens;
-            let galley = ui.painter().layout_no_wrap(m.clone(), Tokens::ui(12.0), t.text);
-            let r = egui::Rect::from_min_size(egui::pos2(full.min.x + 16.0, full.max.y - 44.0 - lift), galley.size() + egui::vec2(24.0, 14.0));
-            ui.painter().rect_filled(r, 6.0, t.panel_bg);
-            ui.painter().rect_stroke(r, 6.0, egui::Stroke::new(1.0, t.field_border), egui::StrokeKind::Inside);
-            ui.painter().galley(r.min + egui::vec2(12.0, 7.0), galley, t.text);
-            self.auto.add("toast", r, &m);
-            let resp = ui.interact(r, egui::Id::unique("toast"), egui::Sense::click());
-            if resp.clicked() {
-                self.ui.status.clear();
-                self.toast = None;
-            }
-            ui.ctx().request_repaint_after(std::time::Duration::from_millis(500));
-            if !self.ui.status.is_empty() {
-                let since: f64 = ui.data(|d| d.get_temp(egui::Id::unique("status-since")).unwrap_or(now));
-                ui.data_mut(|d| d.insert_temp(egui::Id::unique("status-since"), since));
-                if now - since > 5.0 {
-                    self.ui.status.clear();
-                    ui.data_mut(|d| d.remove::<f64>(egui::Id::unique("status-since")));
-                }
-            }
-        }
-    }
-}
-
-impl EffectcraftApp {
-    /// Scripts' `app.scheduleTask` tasks that are due (repeating ones keep a ScriptUI panel
-    /// fresh): errors as a toast, the last line printed in the status bar, and a repaint when
-    /// the next one is due.
-    fn run_script_tasks(&mut self, ctx: &egui::Context) {
-        if self.session.script_ui.task_hosts.is_empty() {
-            return;
-        }
-        let previous_comp = self.session.active_comp_id();
-        let Some(r) = effectcraft_engine::scriptui::ScriptUi::run_tasks(&mut self.session) else { return };
-        if self.session.active_comp_id().is_some() && self.session.active_comp_id() != previous_comp {
-            self.ui.start_screen = false;
-        }
-        if let Some(msg) = r["errors"].as_array().and_then(|e| e.first()).and_then(|e| e["message"].as_str()) {
-            self.toast = Some((format!("Scheduled script task: {msg}"), self.now));
-        } else if let Some(line) = r["output"].as_array().and_then(|o| o.last()).and_then(|l| l.as_str()) {
-            self.ui.status = line.to_string();
-        }
-        if let Some(next) = r["next"].as_u64() {
-            ctx.request_repaint_after(std::time::Duration::from_millis(next));
-        }
-    }
-
-    /// Auto-save a dirty project when the interval has passed (Settings ▸ Project ▸ Auto-Save).
-    fn tick_autosave(&mut self, ctx: &egui::Context) {
-        // Monotonic app time: a wall-clock jump must not skip or repeat an auto-save.
-        let now = self.now;
-        if let Some(Err(e)) = self.session.autosave_tick(now) {
-            self.ui.status = e.to_string();
-        }
-        if self.session.prefs.auto_save.enabled {
-            ctx.request_repaint_after(std::time::Duration::from_secs(30));
-        }
-        // File ▸ Watch Folder: look for new projects every 10 seconds.
-        if self.session.state.watch_folder.is_some() {
-            let key = egui::Id::unique("watchFolder.lastPoll");
-            let last: f64 = ctx.data(|d| d.get_temp(key)).unwrap_or(0.0);
-            if now - last >= 10.0 {
-                ctx.data_mut(|d| d.insert_temp(key, now));
-                match self.session.execute("file.watchFolder.poll", serde_json::json!({})) {
-                    Ok(r) => {
-                        if let Some(n) = r["rendered"].as_array().map(Vec::len).filter(|n| *n > 0) {
-                            self.ui.status = format!("Watch Folder: rendered {n} project(s)");
-                        }
-                    }
-                    Err(e) => self.ui.status = e.to_string(),
-                }
-            }
-            ctx.request_repaint_after(std::time::Duration::from_secs(10));
-        }
-        self.tick_footage_reload(ctx, now);
-    }
-
-    /// Settings ▸ Import ▸ Reload Footage Changed on Disk: every two seconds, and as soon as the
-    /// window comes back to the front (after saving in another app), stamp the footage files on a
-    /// worker thread and reload the ones that changed.
-    fn tick_footage_reload(&mut self, ctx: &egui::Context, now: f64) {
-        use effectcraft_engine::footage_reload;
-        if let Some(Err(e)) = footage_reload::poll_scan(&mut self.session) {
-            self.ui.status = e.to_string();
-        }
-        let (last_key, focus_key) = (egui::Id::unique("footageReload.lastScan"), egui::Id::unique("footageReload.focused"));
-        let focused = self.focused;
-        let was_focused: bool = ctx.data(|d| d.get_temp(focus_key)).unwrap_or(focused);
-        ctx.data_mut(|d| d.insert_temp(focus_key, focused));
-        if self.session.prefs.import.auto_reload_footage == "off" || self.session.project.items.is_empty() {
-            return;
-        }
-        let last: f64 = ctx.data(|d| d.get_temp(last_key)).unwrap_or(0.0);
-        if now - last >= 2.0 || (focused && !was_focused) {
-            ctx.data_mut(|d| d.insert_temp(last_key, now));
-            footage_reload::start_scan(&mut self.session);
-        }
-        if self.session.footage_scan.is_some() {
-            ctx.request_repaint_after(std::time::Duration::from_millis(100));
-        } else {
-            ctx.request_repaint_after(std::time::Duration::from_secs(2));
-        }
-    }
-
-    /// Take the pending synthetic input (from `ui.click`, `ui.key`, …). Hosts that don't call
-    /// [`eframe::App::raw_input_hook`] (the headless test harness) feed these in themselves.
-    pub fn take_synthetic_input(&mut self) -> Vec<egui::Event> {
-        std::mem::take(&mut self.synthetic)
-    }
-}
-
 /// Non-blocking file dialogs ([`Hooks::file_dialog_async`]) that are up. While one is, the dock
 /// area blocks floating panels' OS windows, as it does for a modal dialog; otherwise craft-ui
 /// takes the app for inactive while the dialog has the keyboard, and hides floating palettes.
@@ -2713,50 +412,6 @@ pub(crate) struct ForwardedInput {
     pub(crate) files: Vec<egui::DroppedFileHandle>,
 }
 
-impl eframe::App for EffectcraftApp {
-    fn on_exit(&mut self) {
-        self.save_workspace_state();
-        // Clean exit: no crash recovery next launch (unless the graphics device was lost with
-        // unsaved changes, which are in the auto-save it offers).
-        if self.device_lost_close != Some(true) {
-            self.session.end_recovery();
-        }
-    }
-
-    /// Feed pending synthetic input into `raw_input` only once fonts are ready (so a non-drawing pass never consumes
-    /// a batch), then prepare pointer wrapping; ending a numeric scrub clears the history merge key so the next edit
-    /// starts a new undo step.
-    fn raw_input_hook(&mut self, ctx: &egui::Context, raw_input: &mut egui::RawInput) {
-        raw_input.events.append(&mut self.forwarded.events);
-        raw_input.dropped_files.append(&mut self.forwarded.files);
-        let injected = self.synthetic_in_flight || !self.synthetic.is_empty();
-        // Only a pass that can draw may receive synthetic input: `Context::run_ui` applies
-        // everything the hook feeds to its input state, so a pass that cannot draw (fonts still
-        // installing) would consume a batch it could not put back — putting it back would apply
-        // the click/key state twice. The queue waits here for the first pass that draws.
-        if self.fonts_ready {
-            self.feed_synthetic(raw_input);
-        }
-        if pointer_wrap::prepare_input(ctx, raw_input, injected) {
-            self.session.history.merge_key = None;
-        }
-    }
-
-    /// The logic-only tick: run `tick` and close the IME pass with `finish_ime_logic`. It does not read pass-time
-    /// input state (events, pointer and time are stale here), only the viewport information eframe refreshed.
-    fn logic(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame) {
-        // Never `ctx.input(|i| i.time)` here: `Context::run_logic` leaves events, pointer state and
-        // time at the previous full pass's values (only the viewport information is refreshed).
-        self.tick(ctx, frame);
-        self.finish_ime_logic(ctx);
-    }
-
-    /// Draw one UI pass through `draw`.
-    fn ui(&mut self, ui: &mut egui::Ui, frame: &mut eframe::Frame) {
-        self.draw(ui, frame);
-    }
-}
-
 /// Record the scale the viewer drew at (called by the viewer panel each pass).
 ///
 /// Playback itself advances in [`EffectcraftApp::tick`], so it keeps running while the window is
@@ -2765,753 +420,5 @@ pub(crate) fn note_viewer_scale(app: &mut EffectcraftApp, scale: f64) {
     app.last_viewer_scale = Some(scale);
 }
 
-/// Put `width` × `height` straight-alpha RGBA8 pixels on the system clipboard (Composition ▸ Copy
-/// Frame to Clipboard). The pixel count is checked first: egui's image constructor panics on a
-/// size that doesn't match its buffer.
-fn copy_image(ctx: &egui::Context, width: u32, height: u32, rgba: &[u8]) -> Result<(), String> {
-    let (w, h) = (width as usize, height as usize);
-    if w == 0 || h == 0 || w.checked_mul(h).and_then(|n| n.checked_mul(4)) != Some(rgba.len()) {
-        return Err(format!("cannot copy a malformed {width}×{height} image to the clipboard"));
-    }
-    ctx.copy_image(egui::ColorImage::from_rgba_unmultiplied([w, h], rgba));
-    Ok(())
-}
-
-/// Maximize a first window that doesn't fit the screen, which fits it to the space beside the
-/// taskbar or dock. The 1680 × 1020 window on a smaller screen is only shrunk to the monitor's
-/// size, so with its title bar it ran under the taskbar and cut menus off at the bottom of the
-/// screen (#269).
-fn fit_window(ctx: &egui::Context) {
-    let (monitor, window) = ctx.input(|i| (i.viewport().monitor_size, i.viewport().outer_rect.or(i.viewport().inner_rect)));
-    if let (Some(monitor), Some(window)) = (monitor, window)
-        && overflows_screen(window.size(), monitor)
-    {
-        ctx.send_viewport_cmd(egui::ViewportCommand::Maximized(true));
-    }
-}
-
-/// Whether a window `size` leaves no room on a `monitor` for a taskbar or dock (points).
-fn overflows_screen(size: egui::Vec2, monitor: egui::Vec2) -> bool {
-    const TASKBAR: f32 = 64.0;
-    size.x > monitor.x || size.y > monitor.y - TASKBAR
-}
-
 #[cfg(test)]
-mod fit_window_tests {
-    use super::overflows_screen;
-    use egui::vec2;
-
-    #[test]
-    fn a_window_taller_than_the_screen_beside_its_taskbar_overflows() {
-        // The default window on a 1366 × 768 laptop (shrunk to the monitor) and on 1080p.
-        assert!(overflows_screen(vec2(1366.0, 799.0), vec2(1366.0, 768.0)));
-        assert!(overflows_screen(vec2(1680.0, 1051.0), vec2(1920.0, 1080.0)));
-        assert!(!overflows_screen(vec2(1680.0, 1051.0), vec2(2560.0, 1440.0)));
-    }
-}
-
-#[cfg(test)]
-mod copy_frame_tests {
-    use super::*;
-
-    fn copied(output: &egui::FullOutput) -> Vec<&egui::ColorImage> {
-        output
-            .platform_output
-            .commands
-            .iter()
-            .filter_map(|c| match c {
-                egui::OutputCommand::CopyImage(image) => Some(image),
-                _ => None,
-            })
-            .collect()
-    }
-
-    /// Composition ▸ Copy Frame to Clipboard puts the rendered frame on the system clipboard.
-    #[test]
-    fn copy_frame_puts_the_frame_on_the_clipboard() {
-        let mut session = Session::default();
-        session.execute("comp.new", json!({"name": "Copy", "width": 8, "height": 6, "duration": 1})).unwrap();
-        session.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap();
-        let mut app = EffectcraftApp::new(session);
-        let ctx = egui::Context::default();
-        let mut output = ctx.run_ui(egui::RawInput::default(), |ui| {
-            crate::menus::invoke(&mut app, ui.ctx(), "comp.copyFrame", json!({})).unwrap();
-            app.handle_events(ui.ctx());
-        });
-        output.textures_delta.clear();
-        let images = copied(&output);
-        assert_eq!(images.len(), 1);
-        assert_eq!(images[0].size, [8, 6]);
-        assert!(images[0].pixels.iter().all(|p| *p == egui::Color32::from_rgb(255, 0, 0)));
-    }
-
-    /// A malformed image never reaches egui's panicking constructor.
-    #[test]
-    fn a_malformed_image_is_an_error_not_a_crash() {
-        let ctx = egui::Context::default();
-        let mut output = ctx.run_ui(egui::RawInput::default(), |ui| {
-            assert!(copy_image(ui.ctx(), 4, 4, &[0; 10]).is_err());
-            assert!(copy_image(ui.ctx(), 0, 4, &[]).is_err());
-            assert!(copy_image(ui.ctx(), u32::MAX, u32::MAX, &[0; 4]).is_err());
-        });
-        output.textures_delta.clear();
-        assert!(copied(&output).is_empty());
-    }
-}
-
-#[cfg(test)]
-mod gpu_failure_tests {
-    use super::*;
-
-    #[test]
-    fn host_failure_preserves_document_undo_and_cpu_pixels_and_detaches_late_readbacks() {
-        let mut session = Session::default();
-        let comp = ItemId(session.execute("comp.new", json!({"name": "Recovery", "width": 4, "height": 4, "duration": 1})).unwrap()["comp"].as_u64().unwrap());
-        session.execute("layer.newSolid", json!({"comp": comp.0, "color": "#ff0000"})).unwrap();
-        let before = session.render(comp, Tick::ZERO, RenderOpts::default());
-        let project = session.project.clone();
-        let revision = session.revision;
-        let prefs = serde_json::to_value(&session.prefs).unwrap();
-        let mut app = EffectcraftApp::new(session);
-        let ctx = egui::Context::default();
-        let bridge = gpu_failure::GpuFailureBridge::new(&ctx);
-        app.set_gpu_failure_bridge(bridge.clone());
-        let late_slot = app.viewer_readback.1.clone();
-        let key = FrameKey { revision, content: 1, comp: comp.0, frame: 0, scale: 1000, view: 0, opts: 0 };
-        app.viewer_readback.0 = Some(key);
-        bridge.report("synthetic host device failure", true);
-        app.apply_gpu_failure(&ctx);
-        assert!(Arc::ptr_eq(&project, &app.session.project));
-        assert_eq!(app.session.revision, revision);
-        assert_eq!(serde_json::to_value(&app.session.prefs).unwrap(), prefs);
-        assert!(app.gpu_checked, "failed device cannot be initialized again next frame");
-        assert!(app.session.accel.is_none());
-        assert!(app.ui.status.contains("presentation requires restarting"));
-        assert_eq!(app.session.render(comp, Tick::ZERO, RenderOpts::default()).data, before.data);
-        *late_slot.lock().unwrap() = Some((key, Arc::new(egui::ColorImage::new([1, 1], vec![egui::Color32::RED]))));
-        assert!(app.viewer_readback.0.is_none());
-        assert!(app.viewer_readback.1.lock().unwrap().is_none(), "a late completion cannot refill the replacement slot");
-        app.session.execute("edit.undo", json!({})).unwrap();
-        assert!(app.session.project.comp(comp).unwrap().layers.is_empty());
-        app.session.execute("edit.redo", json!({})).unwrap();
-        assert_eq!(app.session.render(comp, Tick::ZERO, RenderOpts::default()).data, before.data);
-    }
-}
-
-#[cfg(test)]
-mod appearance_tests {
-    use super::*;
-    use crate::theme::ThemeKind;
-
-    fn app() -> EffectcraftApp {
-        EffectcraftApp::new(effectcraft_engine::Session::default())
-    }
-
-    /// The Tools bar's appearance button: Sync with System, Light, Dark, then Sync with System
-    /// again, showing the saved theme of each family without losing either choice.
-    #[test]
-    fn appearance_button_cycles_modes_without_losing_theme_choices() {
-        let ctx = egui::Context::default();
-        let mut app = app();
-        app.hooks.system_theme = Some(Box::new(|_| Some(egui::Theme::Dark)));
-        app.set_pref("appearance.darkTheme", json!("darker")).unwrap();
-        app.apply_prefs(&ctx);
-        assert_eq!(app.ui.theme, ThemeKind::Darker);
-        for (mode, shown) in [("auto", ThemeKind::Darker), ("light", ThemeKind::Light), ("dark", ThemeKind::Darker), ("auto", ThemeKind::Darker)] {
-            menus::invoke(&mut app, &ctx, "view.theme.toggle", json!({})).unwrap();
-            assert_eq!(app.session.prefs.appearance.appearance_mode, mode);
-            assert_eq!(app.ui.theme, shown, "{mode}");
-            assert_eq!(app.tokens.kind, shown);
-            assert_eq!(app.session.prefs.appearance.dark_theme, "darker");
-            assert_eq!(app.session.prefs.appearance.light_theme, "light");
-        }
-    }
-
-    /// Sync with System follows the host's answer (the Linux portal) when it changes, and falls
-    /// back to Dark when nothing reports a system appearance.
-    #[test]
-    fn auto_follows_a_stubbed_system_theme() {
-        use std::sync::{Arc, Mutex};
-        let ctx = egui::Context::default();
-        let mut app = app();
-        let system = Arc::new(Mutex::new(Some(egui::Theme::Light)));
-        let read = Arc::clone(&system);
-        app.hooks.system_theme = Some(Box::new(move |_| *read.lock().unwrap_or_else(std::sync::PoisonError::into_inner)));
-        app.set_pref("appearance.appearanceMode", json!("auto")).unwrap();
-        app.apply_prefs(&ctx);
-        assert_eq!(app.ui.theme, ThemeKind::Light);
-        *system.lock().unwrap() = Some(egui::Theme::Dark);
-        app.apply_prefs(&ctx);
-        assert_eq!(app.ui.theme, ThemeKind::Dark, "a system change applies without a settings change");
-        *system.lock().unwrap() = None;
-        app.apply_prefs(&ctx);
-        assert_eq!(app.ui.theme, ThemeKind::Dark);
-        // A fixed mode ignores the system.
-        *system.lock().unwrap() = Some(egui::Theme::Light);
-        app.set_pref("appearance.appearanceMode", json!("dark")).unwrap();
-        app.apply_prefs(&ctx);
-        assert_eq!(app.ui.theme, ThemeKind::Dark);
-    }
-
-    /// Sync with System leaves egui's theme preference at System, so egui never gives the native
-    /// window an appearance of its own (on macOS that stops system appearance changes reaching
-    /// the app, #642); egui's light and dark styles both carry the resolved theme. Fixed modes
-    /// pin the window to their family.
-    #[test]
-    fn auto_mode_leaves_the_native_window_following_the_system() {
-        let ctx = egui::Context::default();
-        let mut app = app();
-        app.hooks.system_theme = Some(Box::new(|_| Some(egui::Theme::Light)));
-        app.set_pref("appearance.appearanceMode", json!("auto")).unwrap();
-        app.apply_prefs(&ctx);
-        assert_eq!(app.ui.theme, ThemeKind::Light);
-        assert_eq!(ctx.options(|o| o.theme_preference), egui::ThemePreference::System);
-        for theme in [egui::Theme::Light, egui::Theme::Dark] {
-            assert_eq!(ctx.style_of(theme).visuals.panel_fill, app.tokens.panel_bg, "{theme:?}");
-        }
-        // egui asks the window to follow the system, never to take Light or Dark.
-        let mut out = ctx.run_ui(egui::RawInput::default(), |_| {});
-        out.textures_delta.clear();
-        let cmds = out.viewport_output.values().flat_map(|v| v.commands.iter()).collect::<Vec<_>>();
-        assert!(!cmds.iter().any(|c| matches!(c, egui::ViewportCommand::SetTheme(t) if t != &egui::SystemTheme::SystemDefault)), "{cmds:?}");
-        for (mode, pref) in [("light", egui::ThemePreference::Light), ("dark", egui::ThemePreference::Dark)] {
-            app.set_pref("appearance.appearanceMode", json!(mode)).unwrap();
-            app.apply_prefs(&ctx);
-            assert_eq!(ctx.options(|o| o.theme_preference), pref, "{mode}");
-            assert_eq!(ctx.global_style().visuals.panel_fill, app.tokens.panel_bg, "{mode}");
-        }
-    }
-
-    /// Picking a theme (`view.theme.*`, `ui.set {theme}`) fixes the mode to its family.
-    #[test]
-    fn picking_a_theme_fixes_its_mode() {
-        let ctx = egui::Context::default();
-        let mut app = app();
-        app.set_pref("appearance.appearanceMode", json!("auto")).unwrap();
-        menus::invoke(&mut app, &ctx, "view.theme.light", json!({})).unwrap();
-        assert_eq!(app.session.prefs.appearance.appearance_mode, "light");
-        assert_eq!(app.ui.theme, ThemeKind::Light);
-        menus::invoke(&mut app, &ctx, "view.theme.darker", json!({})).unwrap();
-        assert_eq!(app.session.prefs.appearance.appearance_mode, "dark");
-        assert_eq!(app.session.prefs.appearance.dark_theme, "darker");
-        assert_eq!(app.ui.theme, ThemeKind::Darker);
-    }
-}
-
-#[cfg(test)]
-mod lifecycle_tests {
-    //! The logic-only / UI-pass split: queue work in `tick`, input, layout and setup in `draw`.
-    //!
-    //! The driver mirrors eframe's order for a hidden window: `raw_input_hook` prepares the raw
-    //! input, a logic-only iteration runs `tick`, and a forced pass runs `draw` with the same
-    //! prepared input. Nothing may depend on `current_pass_index`, which is zero in both.
-
-    use super::*;
-    use effectcraft_engine::config::{ConfigStore, MemoryConfig};
-
-    fn app_with_comp() -> EffectcraftApp {
-        let mut session = Session::default();
-        session.execute("comp.new", json!({"name": "Lifecycle", "width": 64, "height": 36, "duration": 1})).unwrap();
-        session.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap();
-        let mut app = EffectcraftApp::new(session);
-        app.ui.start_screen = false;
-        app.ui.show_menu_bar = false;
-        app.use_manual_clock();
-        app
-    }
-
-    fn raw(size: egui::Vec2) -> egui::RawInput {
-        egui::RawInput { screen_rect: Some(egui::Rect::from_min_size(egui::Pos2::ZERO, size)), ..Default::default() }
-    }
-
-    fn tick_with(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame, raw: &egui::RawInput) -> egui::LogicOutput {
-        ctx.run_logic(raw, |ctx| app.tick(ctx, frame))
-    }
-
-    fn hidden_tick(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame) {
-        let _ = tick_with(app, ctx, frame, &raw(egui::vec2(800.0, 480.0)));
-    }
-
-    /// One host iteration that ends in a UI pass (the forced hidden pass, or a visible frame).
-    fn pass(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame, raw: &mut egui::RawInput) -> egui::FullOutput {
-        eframe::App::raw_input_hook(app, ctx, raw);
-        let mut out = ctx.run_ui(raw.take(), |ui| app.draw(ui, frame));
-        out.textures_delta.clear();
-        out
-    }
-
-    fn ready(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame) -> DrawGeometry {
-        // The first pass installs the fonts, the second draws with them.
-        for _ in 0..3 {
-            let mut raw = raw(egui::vec2(800.0, 480.0));
-            pass(app, ctx, frame, &mut raw);
-        }
-        assert!(app.is_ready(), "fonts are ready after the warm-up passes");
-        app.draw_geometry().expect("a completed pass records its geometry")
-    }
-
-    fn send(app: &mut EffectcraftApp, method: &str, params: serde_json::Value) -> std::sync::mpsc::Receiver<serde_json::Value> {
-        let (request, reply) = ControlRequest::new(method, params);
-        let (tx, rx) = std::sync::mpsc::channel();
-        tx.send(request).unwrap();
-        app.control_rx = Some(rx);
-        reply
-    }
-
-    #[test]
-    fn a_logic_only_tick_installs_no_fonts_and_records_no_geometry() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        hidden_tick(&mut app, &ctx, &frame);
-        assert!(!app.is_ready(), "fonts need a real pass, not a logic-only tick");
-        assert!(app.draw_geometry().is_none(), "a logic-only tick is not a frame");
-        assert_eq!(app.ui_passes(), 0);
-    }
-
-    #[test]
-    fn a_control_command_that_needs_no_ui_completes_without_a_pass() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        let reply = send(&mut app, "engine.execute", json!({"command": "comp.new", "params": {"name": "Queued", "width": 32, "height": 18, "duration": 1}}));
-        hidden_tick(&mut app, &ctx, &frame);
-        let value = reply.try_recv().expect("a command that needs no UI is answered by the tick");
-        assert_eq!(value["ok"], true, "{value}");
-        assert_eq!(app.ui_passes(), 0);
-    }
-
-    #[test]
-    fn a_pass_that_cannot_draw_receives_no_synthetic_input() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        assert!(!app.is_ready(), "a fresh app installs its fonts in its first pass");
-        let reply = send(&mut app, "ui.click", json!({"x": 40, "y": 40}));
-        hidden_tick(&mut app, &ctx, &frame);
-        assert!(reply.try_recv().is_err(), "a click is not answered before its UI pass");
-        // The font-install pass cannot draw. It must not receive the click: `run_ui` applies what
-        // the hook feeds, and a batch cannot be put back without applying its pointer state twice.
-        let mut setup = raw(egui::vec2(800.0, 480.0));
-        eframe::App::raw_input_hook(&mut app, &ctx, &mut setup);
-        assert!(setup.events.is_empty(), "a pass that cannot draw gets no synthetic input");
-        assert_eq!(app.synthetic.len(), 5, "the whole gesture still waits for a drawing pass");
-        assert!(app.pending_synthetic_events().is_empty());
-        let mut setup_pass = ctx.run_ui(setup.take(), |ui| app.draw(ui, &frame));
-        setup_pass.textures_delta.clear();
-        assert!(!app.is_ready(), "the pass that installs the fonts draws nothing");
-        // Once fonts are ready the click reaches the UI exactly once, one event per pass.
-        let mut passes = 0;
-        while reply.try_recv().is_err() {
-            passes += 1;
-            assert!(passes < 40, "the click must be applied within a few passes");
-            let mut raw = raw(egui::vec2(800.0, 480.0));
-            pass(&mut app, &ctx, &frame, &mut raw);
-        }
-        assert!(reply.try_recv().is_err(), "the reply is sent once");
-        assert!(app.pending_synthetic_events().is_empty());
-        assert!(app.synthetic.is_empty(), "every event was applied once");
-    }
-
-    #[test]
-    fn one_pending_synthetic_batch_is_never_duplicated_while_hidden() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        ready(&mut app, &ctx, &frame);
-        let reply = send(&mut app, "ui.click", json!({"x": 40, "y": 40}));
-        hidden_tick(&mut app, &ctx, &frame);
-        assert!(reply.try_recv().is_err(), "a click is not answered before its UI pass");
-        // Several hidden host iterations: eframe keeps the first prepared input; only its one
-        // event may reach the raw input, and a later hook must not add another.
-        let mut first = raw(egui::vec2(800.0, 480.0));
-        eframe::App::raw_input_hook(&mut app, &ctx, &mut first);
-        assert_eq!(first.events.len(), 1, "the first event of the gesture is fed");
-        let mut second = raw(egui::vec2(800.0, 480.0));
-        eframe::App::raw_input_hook(&mut app, &ctx, &mut second);
-        assert!(second.events.is_empty(), "an unapplied batch blocks the next event");
-        assert_eq!(app.pending_synthetic_events().len(), 1);
-        // The pass that applies the batch acknowledges it once; it is never fed again.
-        pass(&mut app, &ctx, &frame, &mut first);
-        assert!(app.pending_synthetic_events().is_empty());
-        // Drive real passes until the gesture is applied: exactly one reply, no lost events.
-        let mut passes = 0;
-        while reply.try_recv().is_err() {
-            passes += 1;
-            assert!(passes < 40, "the click must be applied within a few passes");
-            let mut raw = raw(egui::vec2(800.0, 480.0));
-            pass(&mut app, &ctx, &frame, &mut raw);
-        }
-        assert!(app.pending_synthetic_events().is_empty());
-        assert!(app.synthetic.is_empty());
-        assert!(reply.try_recv().is_err(), "the reply is sent once");
-    }
-
-    #[test]
-    fn geometry_epoch_tracks_size_and_scale_but_not_window_position() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        let first = ready(&mut app, &ctx, &frame);
-        let mut moved = egui::RawInput { screen_rect: Some(egui::Rect::from_min_size(egui::pos2(120.0, 80.0), first.rect.size())), ..Default::default() };
-        pass(&mut app, &ctx, &frame, &mut moved);
-        assert_eq!(app.draw_geometry().unwrap().epoch, first.epoch, "moving the window does not change a capture");
-        let mut resized = raw(egui::vec2(1024.0, 640.0));
-        pass(&mut app, &ctx, &frame, &mut resized);
-        let after_resize = app.draw_geometry().unwrap();
-        assert!(after_resize.epoch > first.epoch, "a resize advances the epoch");
-        let mut back = raw(egui::vec2(800.0, 480.0));
-        pass(&mut app, &ctx, &frame, &mut back);
-        assert!(app.draw_geometry().unwrap().epoch > after_resize.epoch, "changing back is another change, not the old epoch");
-    }
-
-    #[test]
-    fn only_a_viewer_that_draws_records_a_prefetch_scale() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        ready(&mut app, &ctx, &frame);
-        assert!(app.last_viewer_scale.is_some(), "the visible viewer recorded the scale it drew at");
-        // The Home screen draws no viewer: the old comp's scale must not keep idle prefetch alive.
-        app.ui.start_screen = true;
-        let mut input = raw(egui::vec2(800.0, 480.0));
-        pass(&mut app, &ctx, &frame, &mut input);
-        assert!(app.last_viewer_scale.is_none(), "no viewer drew, so there is no scale to prefetch at");
-        // Back to the comp: the next pass records it again.
-        app.ui.start_screen = false;
-        let mut input = raw(egui::vec2(800.0, 480.0));
-        pass(&mut app, &ctx, &frame, &mut input);
-        assert!(app.last_viewer_scale.is_some());
-    }
-
-    #[test]
-    fn playback_advances_on_a_logic_only_tick() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        app.playback.playing = true;
-        app.playback.plan = Some(effectcraft_engine::preview::PreviewPlan {
-            start: 1,
-            end: 1,
-            first: 1,
-            step: 1,
-            fps: 24.0,
-            looping: false,
-            cache_first: false,
-            video: false,
-            audio: false,
-            origin: Tick::ZERO,
-        });
-        app.playback.start_wall = 0.0;
-        app.playback.start_frame = 1;
-        app.clock_mut().advance(1.0);
-        hidden_tick(&mut app, &ctx, &frame);
-        assert!(!app.playback.playing, "a one-frame preview ends without any UI pass");
-        assert_eq!(app.playback.audio_frame, Some(1), "the audio-only playhead reached the plan's end");
-        assert_eq!(app.ui_passes(), 0);
-    }
-
-    #[test]
-    fn workspace_layout_autosave_writes_on_a_hidden_tick() {
-        let store = Arc::new(MemoryConfig::default());
-        let mut app = EffectcraftApp::new(Session { config: Some(store.clone()), ..Default::default() });
-        app.ui.start_screen = false;
-        app.use_manual_clock();
-        app.ui.focused = PanelKind::Timeline;
-        app.clock_mut().advance(2.0);
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        hidden_tick(&mut app, &ctx, &frame);
-        assert!(store.read(WORKSPACES_FILE).is_some(), "the layout is saved while the window is hidden");
-        assert_eq!(app.ui_passes(), 0);
-    }
-
-    #[test]
-    fn the_close_guard_answers_a_close_request_without_a_pass() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        assert!(app.session.is_dirty(), "creating a comp and a layer leaves unsaved changes");
-        let mut raw = raw(egui::vec2(800.0, 480.0));
-        raw.viewports.insert(egui::ViewportId::ROOT, egui::ViewportInfo { events: vec![egui::ViewportEvent::Close], ..Default::default() });
-        let out = tick_with(&mut app, &ctx, &frame, &raw);
-        assert!(app.dialog.is_some(), "a hidden close request opens the unsaved-changes prompt");
-        let cancel = out.viewport_commands.values().flatten().any(|c| matches!(c, egui::ViewportCommand::CancelClose));
-        assert!(cancel, "the window stays open while the prompt is asking");
-        assert_eq!(app.ui_passes(), 0);
-    }
-
-    // ---------------------------------------------------------------- screenshots
-
-    fn screenshot_request(
-        app: &mut EffectcraftApp,
-        ctx: &egui::Context,
-        path: Option<&str>,
-        target: ShotTarget,
-    ) -> std::sync::mpsc::Receiver<serde_json::Value> {
-        let (tx, rx) = std::sync::mpsc::channel();
-        app.admit_screenshot(ctx, path.map(str::to_string), target, tx);
-        rx
-    }
-
-    fn shot_callbacks(out: &egui::LogicOutput) -> Vec<egui::ScreenshotCallback> {
-        out.viewport_commands
-            .values()
-            .flatten()
-            .filter_map(|c| match c {
-                egui::ViewportCommand::Screenshot(cb) => Some(cb.clone()),
-                _ => None,
-            })
-            .collect()
-    }
-
-    /// Three settled passes and the settle delay, then the tick that issues the capture.
-    fn issue_shot(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame) -> egui::ScreenshotCallback {
-        issue_shot_at(app, ctx, frame, egui::vec2(800.0, 480.0))
-    }
-
-    fn issue_shot_at(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame, size: egui::Vec2) -> egui::ScreenshotCallback {
-        for _ in 0..SCREENSHOT_SETTLE_PASSES {
-            let mut raw = raw(size);
-            pass(app, ctx, frame, &mut raw);
-        }
-        app.clock_mut().advance(SCREENSHOT_SETTLE_S + 0.01);
-        let out = tick_with(app, ctx, frame, &raw(size));
-        let cbs = shot_callbacks(&out);
-        assert_eq!(cbs.len(), 1, "one settled screenshot is issued once");
-        cbs.into_iter().next().unwrap()
-    }
-
-    fn image(width: usize, height: usize) -> Arc<egui::ColorImage> {
-        Arc::new(egui::ColorImage::new([width, height], vec![egui::Color32::from_rgb(10, 20, 30); width.checked_mul(height).unwrap()]))
-    }
-
-    #[test]
-    fn a_screenshot_is_issued_only_after_settled_passes_and_writes_from_the_tick() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        ready(&mut app, &ctx, &frame);
-        let path = std::env::temp_dir().join(format!("effectcraft-shot-{}-ok.png", std::process::id()));
-        let _ = std::fs::remove_file(&path);
-        let reply = screenshot_request(&mut app, &ctx, path.to_str(), ShotTarget::Window);
-        // Not settled: a tick issues nothing and asks for passes instead.
-        let out = tick_with(&mut app, &ctx, &frame, &raw(egui::vec2(800.0, 480.0)));
-        assert!(shot_callbacks(&out).is_empty(), "no capture before the UI settles");
-        assert_eq!(out.viewport_commands.values().flatten().filter(|c| matches!(c, egui::ViewportCommand::RequestPaintWhileHidden)).count(), 1);
-        let cb = issue_shot(&mut app, &ctx, &frame);
-        assert!(reply.try_recv().is_err(), "the callback must not write or reply itself");
-        cb.complete(image(800, 480));
-        hidden_tick(&mut app, &ctx, &frame);
-        let value = reply.try_recv().expect("the tick drains the completed slot and replies");
-        assert_eq!(value["ok"], true, "{value}");
-        assert!(path.exists(), "{value}");
-        assert_eq!(value["result"]["width"], 800);
-        assert_eq!(value["result"]["height"], 480);
-        assert_eq!(app.shot_bytes, 0, "the reservation is released");
-        let _ = std::fs::remove_file(&path);
-    }
-
-    #[test]
-    fn a_resize_between_issue_and_completion_rejects_the_pixels_and_retries() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        ready(&mut app, &ctx, &frame);
-        let path = std::env::temp_dir().join(format!("effectcraft-shot-{}-retry.png", std::process::id()));
-        let _ = std::fs::remove_file(&path);
-        let reply = screenshot_request(&mut app, &ctx, path.to_str(), ShotTarget::Window);
-        let first = issue_shot(&mut app, &ctx, &frame);
-        let size = egui::vec2(1024.0, 640.0);
-        let mut resized = raw(size);
-        pass(&mut app, &ctx, &frame, &mut resized);
-        first.complete(image(800, 480));
-        let _ = tick_with(&mut app, &ctx, &frame, &raw(size));
-        assert!(reply.try_recv().is_err(), "pixels from the old surface epoch are discarded");
-        assert!(!path.exists(), "a stale image is never written");
-        // The retry is issued against the new geometry and the new image is accepted.
-        let second = issue_shot_at(&mut app, &ctx, &frame, size);
-        second.complete(image(1024, 640));
-        let _ = tick_with(&mut app, &ctx, &frame, &raw(size));
-        let value = reply.try_recv().expect("the retried capture replies");
-        assert_eq!(value["ok"], true, "{value}");
-        assert_eq!(value["result"]["width"], 1024);
-        let _ = std::fs::remove_file(&path);
-    }
-
-    #[test]
-    fn screenshot_admission_bounds_requests_and_a_timeout_releases_its_reservation() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        ready(&mut app, &ctx, &frame);
-        let mut replies = Vec::new();
-        for _ in 0..MAX_PENDING_SHOTS {
-            replies.push(screenshot_request(&mut app, &ctx, None, ShotTarget::Rect([0.0, 0.0, 4.0, 4.0])));
-        }
-        let refused = screenshot_request(&mut app, &ctx, None, ShotTarget::Rect([0.0, 0.0, 4.0, 4.0]));
-        let value = refused.try_recv().expect("the fifth request is refused immediately");
-        assert_eq!(value["ok"], false, "{value}");
-        // Every queued request times out on a hidden window that presents no frame; each one
-        // releases its reservation exactly once.
-        app.clock_mut().advance(SCREENSHOT_TIMEOUT_S + 1.0);
-        hidden_tick(&mut app, &ctx, &frame);
-        for reply in replies {
-            let value = reply.try_recv().expect("a timed-out request gets an actionable reply");
-            assert_eq!(value["ok"], false, "{value}");
-            assert!(value["error"].as_str().is_some_and(|e| e.contains("no frame")), "{value}");
-        }
-        assert_eq!(app.shot_bytes, 0);
-        assert!(app.pending_screenshots.is_empty());
-    }
-
-    #[test]
-    fn a_late_callback_after_cancellation_writes_nothing_and_replies_once() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        ready(&mut app, &ctx, &frame);
-        let path = std::env::temp_dir().join(format!("effectcraft-shot-{}-late.png", std::process::id()));
-        let _ = std::fs::remove_file(&path);
-        let reply = screenshot_request(&mut app, &ctx, path.to_str(), ShotTarget::Window);
-        let late = issue_shot(&mut app, &ctx, &frame);
-        app.clock_mut().advance(SCREENSHOT_TIMEOUT_S + 1.0);
-        hidden_tick(&mut app, &ctx, &frame);
-        let timeout = reply.try_recv().expect("the request times out");
-        assert_eq!(timeout["ok"], false, "{timeout}");
-        late.complete(image(800, 480));
-        hidden_tick(&mut app, &ctx, &frame);
-        assert!(reply.try_recv().is_err(), "a late completion sends no second reply");
-        assert!(!path.exists(), "a late completion writes no file");
-        assert_eq!(app.shot_bytes, 0);
-    }
-
-    /// Every repaint delay requested on `ctx` (what a host uses to wake the app).
-    fn wake_requests(ctx: &egui::Context) -> Arc<std::sync::Mutex<Vec<std::time::Duration>>> {
-        let wakes: Arc<std::sync::Mutex<Vec<std::time::Duration>>> = Arc::default();
-        let record = Arc::clone(&wakes);
-        ctx.set_repaint_observer(move |i| record.lock().unwrap_or_else(std::sync::PoisonError::into_inner).push(i.delay));
-        wakes
-    }
-
-    #[test]
-    fn an_issued_capture_schedules_a_wake_up_for_its_deadline() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        ready(&mut app, &ctx, &frame);
-        let reply = screenshot_request(&mut app, &ctx, None, ShotTarget::Window);
-        for _ in 0..SCREENSHOT_SETTLE_PASSES {
-            let mut raw = raw(egui::vec2(800.0, 480.0));
-            pass(&mut app, &ctx, &frame, &mut raw);
-        }
-        app.clock_mut().advance(SCREENSHOT_SETTLE_S + 0.01);
-        // Record the repaint requests of the tick that issues the capture only.
-        let wakes = wake_requests(&ctx);
-        let out = tick_with(&mut app, &ctx, &frame, &raw(egui::vec2(800.0, 480.0)));
-        assert_eq!(shot_callbacks(&out).len(), 1, "the settled capture is issued once");
-        let delays = wakes.lock().unwrap_or_else(std::sync::PoisonError::into_inner).clone();
-        // The deadline is 8 s after admission; the capture was issued ~0.31 s in, so the app must
-        // ask for a wake-up close to that timeout, not only for the next paint.
-        let deadline_wake = delays.iter().any(|d| d.as_secs_f64() > 7.0 && d.as_secs_f64() <= SCREENSHOT_TIMEOUT_S);
-        assert!(deadline_wake, "an issued capture asks the host to wake for its timeout: {delays:?}");
-        // The callback never arrives (a hidden window or a display asleep). The host wakes at the
-        // requested delay; without this wake-up the timeout below could never be evaluated.
-        app.clock_mut().advance(SCREENSHOT_TIMEOUT_S + 1.0);
-        hidden_tick(&mut app, &ctx, &frame);
-        let value = reply.try_recv().expect("the deadline wake-up produces the timeout reply");
-        assert_eq!(value["ok"], false, "{value}");
-        assert!(value["error"].as_str().is_some_and(|e| e.contains("no frame")), "{value}");
-        assert_eq!(app.shot_bytes, 0);
-        assert!(app.pending_screenshots.is_empty());
-    }
-
-    #[test]
-    fn a_downscaled_capture_is_cropped_with_the_images_own_scale() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        let geom = ready(&mut app, &ctx, &frame);
-        assert_eq!((geom.rect.width(), geom.rect.height(), geom.ppp), (800.0, 480.0, 1.0));
-        // The adapter-limit fit (E2) returned half the requested pixels. Left red, right blue.
-        let fitted =
-            Arc::new(egui::ColorImage::new([400, 240], (0..400 * 240).map(|i| if i % 400 < 200 { egui::Color32::RED } else { egui::Color32::BLUE }).collect()));
-        let dir = std::env::temp_dir();
-        for (name, crop, want) in [("left", [0.0, 0.0, 400.0, 240.0], egui::Color32::RED), ("right", [400.0, 0.0, 400.0, 240.0], egui::Color32::BLUE)] {
-            let path = dir.join(format!("effectcraft-shot-{}-scale-{name}.png", std::process::id()));
-            let _ = std::fs::remove_file(&path);
-            let reply = screenshot_request(&mut app, &ctx, path.to_str(), ShotTarget::Rect(crop));
-            let cb = issue_shot(&mut app, &ctx, &frame);
-            cb.complete(Arc::clone(&fitted));
-            hidden_tick(&mut app, &ctx, &frame);
-            let value = reply.try_recv().expect("the downscaled capture replies");
-            assert_eq!(value["ok"], true, "{value}");
-            assert_eq!(value["result"]["width"], 200, "{value}");
-            assert_eq!(value["result"]["height"], 120, "{value}");
-            let png = std::fs::read(&path).expect("the PNG is written");
-            let decoded = image::load_from_memory(&png).expect("our PNG decodes").to_rgba8();
-            assert_eq!((decoded.width(), decoded.height()), (200, 120), "{value}");
-            let px = decoded.get_pixel(100, 60).0;
-            assert!(px[0] == want.r() && px[1] == want.g() && px[2] == want.b(), "{name}: {px:?} is not from its half of the fitted image");
-            let _ = std::fs::remove_file(&path);
-        }
-    }
-
-    #[test]
-    fn a_capture_before_any_pass_never_uses_the_window_frame_rect() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        // Only the outer (title bar included) rectangle is known: it is not the captured surface.
-        let outer = egui::Rect::from_min_size(egui::pos2(0.0, -30.0), egui::vec2(800.0, 510.0));
-        let mut raw = egui::RawInput::default();
-        raw.viewports.insert(egui::ViewportId::ROOT, egui::ViewportInfo { outer_rect: Some(outer), ..Default::default() });
-        let _ = tick_with(&mut app, &ctx, &frame, &raw);
-        let (tx, reply) = std::sync::mpsc::channel();
-        app.admit_screenshot(&ctx, None, ShotTarget::Window, tx);
-        let value = reply.try_recv().expect("the request is answered now");
-        assert_eq!(value["ok"], false, "{value}");
-        assert!(value["error"].as_str().is_some_and(|e| e.contains("geometry is not known")), "{value}");
-        assert!(app.pending_screenshots.is_empty(), "nothing was reserved against the wrong rectangle");
-        assert_eq!(app.shot_bytes, 0);
-        assert!(app.want_paint, "the pass that records the geometry is requested");
-    }
-
-    #[test]
-    fn an_element_that_moves_while_the_ui_settles_is_captured_where_it_is() {
-        let ctx = egui::Context::default();
-        let frame = eframe::Frame::_new_kittest();
-        let mut app = app_with_comp();
-        let geom = ready(&mut app, &ctx, &frame);
-        // Any registered panel: the crop follows this element's rectangle.
-        let panel = app.auto.previous.iter().chain(app.auto.elements.iter()).find(|e| e.id.starts_with("panel.")).map(|e| e.id.clone());
-        let panel = panel.expect("a dock panel is on screen after a completed pass");
-        let reply = screenshot_request(&mut app, &ctx, None, ShotTarget::Id(panel.clone()));
-        for _ in 0..SCREENSHOT_SETTLE_PASSES {
-            let mut raw = raw(egui::vec2(800.0, 480.0));
-            pass(&mut app, &ctx, &frame, &mut raw);
-        }
-        // The panel moves after its last draw: the crop must follow it, not the admission rect.
-        let moved = [40.0, 30.0, 300.0, 200.0];
-        for list in [&mut app.auto.previous, &mut app.auto.elements] {
-            if let Some(e) = list.iter_mut().find(|e| e.id == panel) {
-                e.rect = moved;
-            }
-        }
-        app.clock_mut().advance(SCREENSHOT_SETTLE_S + 0.01);
-        let out = tick_with(&mut app, &ctx, &frame, &raw(egui::vec2(800.0, 480.0)));
-        assert_eq!(shot_callbacks(&out).len(), 1, "the settled capture is issued once");
-        let crop = app.pending_screenshots.first().and_then(|s| s.crop).expect("the element crop is resolved at issuance");
-        assert!((crop[0] - (moved[0] - geom.rect.min.x)).abs() < 0.01, "{crop:?}");
-        assert!((crop[1] - (moved[1] - geom.rect.min.y)).abs() < 0.01, "{crop:?}");
-        assert!((crop[2] - moved[2]).abs() < 0.01 && (crop[3] - moved[3]).abs() < 0.01, "{crop:?}");
-        // Let it complete and reply, so the request does not outlive the test.
-        if let Some(cb) = shot_callbacks(&out).into_iter().next() {
-            cb.complete(image(800, 480));
-        }
-        hidden_tick(&mut app, &ctx, &frame);
-        let value = reply.try_recv().expect("the capture replies");
-        assert_eq!(value["ok"], true, "{value}");
-        assert_eq!((value["result"]["width"].as_u64(), value["result"]["height"].as_u64()), (Some(300), Some(200)), "{value}");
-    }
-}
+mod lifecycle_tests;
diff --git a/crates/ui-egui/src/lifecycle_tests.rs b/crates/ui-egui/src/lifecycle_tests.rs
new file mode 100644
index 000000000..6c9eb85d2
--- /dev/null
+++ b/crates/ui-egui/src/lifecycle_tests.rs
@@ -0,0 +1,509 @@
+//! The logic-only / UI-pass split: queue work in `tick`, input, layout and setup in `draw`.
+//!
+//! The driver mirrors eframe's order for a hidden window: `raw_input_hook` prepares the raw
+//! input, a logic-only iteration runs `tick`, and a forced pass runs `draw` with the same
+//! prepared input. Nothing may depend on `current_pass_index`, which is zero in both.
+
+use super::*;
+use effectcraft_engine::config::{ConfigStore, MemoryConfig};
+
+fn app_with_comp() -> EffectcraftApp {
+    let mut session = Session::default();
+    session.execute("comp.new", json!({"name": "Lifecycle", "width": 64, "height": 36, "duration": 1})).unwrap();
+    session.execute("layer.newSolid", json!({"color": "#ff0000"})).unwrap();
+    let mut app = EffectcraftApp::new(session);
+    app.ui.start_screen = false;
+    app.ui.show_menu_bar = false;
+    app.use_manual_clock();
+    app
+}
+
+fn raw(size: egui::Vec2) -> egui::RawInput {
+    egui::RawInput { screen_rect: Some(egui::Rect::from_min_size(egui::Pos2::ZERO, size)), ..Default::default() }
+}
+
+fn tick_with(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame, raw: &egui::RawInput) -> egui::LogicOutput {
+    ctx.run_logic(raw, |ctx| app.tick(ctx, frame))
+}
+
+fn hidden_tick(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame) {
+    let _ = tick_with(app, ctx, frame, &raw(egui::vec2(800.0, 480.0)));
+}
+
+/// One host iteration that ends in a UI pass (the forced hidden pass, or a visible frame).
+fn pass(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame, raw: &mut egui::RawInput) -> egui::FullOutput {
+    eframe::App::raw_input_hook(app, ctx, raw);
+    let mut out = ctx.run_ui(raw.take(), |ui| app.draw(ui, frame));
+    out.textures_delta.clear();
+    out
+}
+
+fn ready(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame) -> DrawGeometry {
+    // The first pass installs the fonts, the second draws with them.
+    for _ in 0..3 {
+        let mut raw = raw(egui::vec2(800.0, 480.0));
+        pass(app, ctx, frame, &mut raw);
+    }
+    assert!(app.is_ready(), "fonts are ready after the warm-up passes");
+    app.draw_geometry().expect("a completed pass records its geometry")
+}
+
+fn send(app: &mut EffectcraftApp, method: &str, params: serde_json::Value) -> std::sync::mpsc::Receiver<serde_json::Value> {
+    let (request, reply) = ControlRequest::new(method, params);
+    let (tx, rx) = std::sync::mpsc::channel();
+    tx.send(request).unwrap();
+    app.control_rx = Some(rx);
+    reply
+}
+
+#[test]
+fn a_logic_only_tick_installs_no_fonts_and_records_no_geometry() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    hidden_tick(&mut app, &ctx, &frame);
+    assert!(!app.is_ready(), "fonts need a real pass, not a logic-only tick");
+    assert!(app.draw_geometry().is_none(), "a logic-only tick is not a frame");
+    assert_eq!(app.ui_passes(), 0);
+}
+
+#[test]
+fn a_control_command_that_needs_no_ui_completes_without_a_pass() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    let reply = send(&mut app, "engine.execute", json!({"command": "comp.new", "params": {"name": "Queued", "width": 32, "height": 18, "duration": 1}}));
+    hidden_tick(&mut app, &ctx, &frame);
+    let value = reply.try_recv().expect("a command that needs no UI is answered by the tick");
+    assert_eq!(value["ok"], true, "{value}");
+    assert_eq!(app.ui_passes(), 0);
+}
+
+#[test]
+fn a_pass_that_cannot_draw_receives_no_synthetic_input() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    assert!(!app.is_ready(), "a fresh app installs its fonts in its first pass");
+    let reply = send(&mut app, "ui.click", json!({"x": 40, "y": 40}));
+    hidden_tick(&mut app, &ctx, &frame);
+    assert!(reply.try_recv().is_err(), "a click is not answered before its UI pass");
+    // The font-install pass cannot draw. It must not receive the click: `run_ui` applies what
+    // the hook feeds, and a batch cannot be put back without applying its pointer state twice.
+    let mut setup = raw(egui::vec2(800.0, 480.0));
+    eframe::App::raw_input_hook(&mut app, &ctx, &mut setup);
+    assert!(setup.events.is_empty(), "a pass that cannot draw gets no synthetic input");
+    assert_eq!(app.synthetic.len(), 5, "the whole gesture still waits for a drawing pass");
+    assert!(app.pending_synthetic_events().is_empty());
+    let mut setup_pass = ctx.run_ui(setup.take(), |ui| app.draw(ui, &frame));
+    setup_pass.textures_delta.clear();
+    assert!(!app.is_ready(), "the pass that installs the fonts draws nothing");
+    // Once fonts are ready the click reaches the UI exactly once, one event per pass.
+    let mut passes = 0;
+    while reply.try_recv().is_err() {
+        passes += 1;
+        assert!(passes < 40, "the click must be applied within a few passes");
+        let mut raw = raw(egui::vec2(800.0, 480.0));
+        pass(&mut app, &ctx, &frame, &mut raw);
+    }
+    assert!(reply.try_recv().is_err(), "the reply is sent once");
+    assert!(app.pending_synthetic_events().is_empty());
+    assert!(app.synthetic.is_empty(), "every event was applied once");
+}
+
+#[test]
+fn one_pending_synthetic_batch_is_never_duplicated_while_hidden() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    ready(&mut app, &ctx, &frame);
+    let reply = send(&mut app, "ui.click", json!({"x": 40, "y": 40}));
+    hidden_tick(&mut app, &ctx, &frame);
+    assert!(reply.try_recv().is_err(), "a click is not answered before its UI pass");
+    // Several hidden host iterations: eframe keeps the first prepared input; only its one
+    // event may reach the raw input, and a later hook must not add another.
+    let mut first = raw(egui::vec2(800.0, 480.0));
+    eframe::App::raw_input_hook(&mut app, &ctx, &mut first);
+    assert_eq!(first.events.len(), 1, "the first event of the gesture is fed");
+    let mut second = raw(egui::vec2(800.0, 480.0));
+    eframe::App::raw_input_hook(&mut app, &ctx, &mut second);
+    assert!(second.events.is_empty(), "an unapplied batch blocks the next event");
+    assert_eq!(app.pending_synthetic_events().len(), 1);
+    // The pass that applies the batch acknowledges it once; it is never fed again.
+    pass(&mut app, &ctx, &frame, &mut first);
+    assert!(app.pending_synthetic_events().is_empty());
+    // Drive real passes until the gesture is applied: exactly one reply, no lost events.
+    let mut passes = 0;
+    while reply.try_recv().is_err() {
+        passes += 1;
+        assert!(passes < 40, "the click must be applied within a few passes");
+        let mut raw = raw(egui::vec2(800.0, 480.0));
+        pass(&mut app, &ctx, &frame, &mut raw);
+    }
+    assert!(app.pending_synthetic_events().is_empty());
+    assert!(app.synthetic.is_empty());
+    assert!(reply.try_recv().is_err(), "the reply is sent once");
+}
+
+#[test]
+fn geometry_epoch_tracks_size_and_scale_but_not_window_position() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    let first = ready(&mut app, &ctx, &frame);
+    let mut moved = egui::RawInput { screen_rect: Some(egui::Rect::from_min_size(egui::pos2(120.0, 80.0), first.rect.size())), ..Default::default() };
+    pass(&mut app, &ctx, &frame, &mut moved);
+    assert_eq!(app.draw_geometry().unwrap().epoch, first.epoch, "moving the window does not change a capture");
+    let mut resized = raw(egui::vec2(1024.0, 640.0));
+    pass(&mut app, &ctx, &frame, &mut resized);
+    let after_resize = app.draw_geometry().unwrap();
+    assert!(after_resize.epoch > first.epoch, "a resize advances the epoch");
+    let mut back = raw(egui::vec2(800.0, 480.0));
+    pass(&mut app, &ctx, &frame, &mut back);
+    assert!(app.draw_geometry().unwrap().epoch > after_resize.epoch, "changing back is another change, not the old epoch");
+}
+
+#[test]
+fn only_a_viewer_that_draws_records_a_prefetch_scale() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    ready(&mut app, &ctx, &frame);
+    assert!(app.last_viewer_scale.is_some(), "the visible viewer recorded the scale it drew at");
+    // The Home screen draws no viewer: the old comp's scale must not keep idle prefetch alive.
+    app.ui.start_screen = true;
+    let mut input = raw(egui::vec2(800.0, 480.0));
+    pass(&mut app, &ctx, &frame, &mut input);
+    assert!(app.last_viewer_scale.is_none(), "no viewer drew, so there is no scale to prefetch at");
+    // Back to the comp: the next pass records it again.
+    app.ui.start_screen = false;
+    let mut input = raw(egui::vec2(800.0, 480.0));
+    pass(&mut app, &ctx, &frame, &mut input);
+    assert!(app.last_viewer_scale.is_some());
+}
+
+#[test]
+fn playback_advances_on_a_logic_only_tick() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    app.playback.playing = true;
+    app.playback.plan = Some(effectcraft_engine::preview::PreviewPlan {
+        start: 1,
+        end: 1,
+        first: 1,
+        step: 1,
+        fps: 24.0,
+        looping: false,
+        cache_first: false,
+        video: false,
+        audio: false,
+        origin: Tick::ZERO,
+    });
+    app.playback.start_wall = 0.0;
+    app.playback.start_frame = 1;
+    app.clock_mut().advance(1.0);
+    hidden_tick(&mut app, &ctx, &frame);
+    assert!(!app.playback.playing, "a one-frame preview ends without any UI pass");
+    assert_eq!(app.playback.audio_frame, Some(1), "the audio-only playhead reached the plan's end");
+    assert_eq!(app.ui_passes(), 0);
+}
+
+#[test]
+fn workspace_layout_autosave_writes_on_a_hidden_tick() {
+    let store = Arc::new(MemoryConfig::default());
+    let mut app = EffectcraftApp::new(Session { config: Some(store.clone()), ..Default::default() });
+    app.ui.start_screen = false;
+    app.use_manual_clock();
+    app.ui.focused = PanelKind::Timeline;
+    app.clock_mut().advance(2.0);
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    hidden_tick(&mut app, &ctx, &frame);
+    assert!(store.read(WORKSPACES_FILE).is_some(), "the layout is saved while the window is hidden");
+    assert_eq!(app.ui_passes(), 0);
+}
+
+#[test]
+fn the_close_guard_answers_a_close_request_without_a_pass() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    assert!(app.session.is_dirty(), "creating a comp and a layer leaves unsaved changes");
+    let mut raw = raw(egui::vec2(800.0, 480.0));
+    raw.viewports.insert(egui::ViewportId::ROOT, egui::ViewportInfo { events: vec![egui::ViewportEvent::Close], ..Default::default() });
+    let out = tick_with(&mut app, &ctx, &frame, &raw);
+    assert!(app.dialog.is_some(), "a hidden close request opens the unsaved-changes prompt");
+    let cancel = out.viewport_commands.values().flatten().any(|c| matches!(c, egui::ViewportCommand::CancelClose));
+    assert!(cancel, "the window stays open while the prompt is asking");
+    assert_eq!(app.ui_passes(), 0);
+}
+
+// ---------------------------------------------------------------- screenshots
+
+fn screenshot_request(app: &mut EffectcraftApp, ctx: &egui::Context, path: Option<&str>, target: ShotTarget) -> std::sync::mpsc::Receiver<serde_json::Value> {
+    let (tx, rx) = std::sync::mpsc::channel();
+    app.admit_screenshot(ctx, path.map(str::to_string), target, tx);
+    rx
+}
+
+fn shot_callbacks(out: &egui::LogicOutput) -> Vec<egui::ScreenshotCallback> {
+    out.viewport_commands
+        .values()
+        .flatten()
+        .filter_map(|c| match c {
+            egui::ViewportCommand::Screenshot(cb) => Some(cb.clone()),
+            _ => None,
+        })
+        .collect()
+}
+
+/// Three settled passes and the settle delay, then the tick that issues the capture.
+fn issue_shot(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame) -> egui::ScreenshotCallback {
+    issue_shot_at(app, ctx, frame, egui::vec2(800.0, 480.0))
+}
+
+fn issue_shot_at(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame, size: egui::Vec2) -> egui::ScreenshotCallback {
+    for _ in 0..SCREENSHOT_SETTLE_PASSES {
+        let mut raw = raw(size);
+        pass(app, ctx, frame, &mut raw);
+    }
+    app.clock_mut().advance(SCREENSHOT_SETTLE_S + 0.01);
+    let out = tick_with(app, ctx, frame, &raw(size));
+    let cbs = shot_callbacks(&out);
+    assert_eq!(cbs.len(), 1, "one settled screenshot is issued once");
+    cbs.into_iter().next().unwrap()
+}
+
+fn image(width: usize, height: usize) -> Arc<egui::ColorImage> {
+    Arc::new(egui::ColorImage::new([width, height], vec![egui::Color32::from_rgb(10, 20, 30); width.checked_mul(height).unwrap()]))
+}
+
+#[test]
+fn a_screenshot_is_issued_only_after_settled_passes_and_writes_from_the_tick() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    ready(&mut app, &ctx, &frame);
+    let path = std::env::temp_dir().join(format!("effectcraft-shot-{}-ok.png", std::process::id()));
+    let _ = std::fs::remove_file(&path);
+    let reply = screenshot_request(&mut app, &ctx, path.to_str(), ShotTarget::Window);
+    // Not settled: a tick issues nothing and asks for passes instead.
+    let out = tick_with(&mut app, &ctx, &frame, &raw(egui::vec2(800.0, 480.0)));
+    assert!(shot_callbacks(&out).is_empty(), "no capture before the UI settles");
+    assert_eq!(out.viewport_commands.values().flatten().filter(|c| matches!(c, egui::ViewportCommand::RequestPaintWhileHidden)).count(), 1);
+    let cb = issue_shot(&mut app, &ctx, &frame);
+    assert!(reply.try_recv().is_err(), "the callback must not write or reply itself");
+    cb.complete(image(800, 480));
+    hidden_tick(&mut app, &ctx, &frame);
+    let value = reply.try_recv().expect("the tick drains the completed slot and replies");
+    assert_eq!(value["ok"], true, "{value}");
+    assert!(path.exists(), "{value}");
+    assert_eq!(value["result"]["width"], 800);
+    assert_eq!(value["result"]["height"], 480);
+    assert_eq!(app.shot_bytes, 0, "the reservation is released");
+    let _ = std::fs::remove_file(&path);
+}
+
+#[test]
+fn a_resize_between_issue_and_completion_rejects_the_pixels_and_retries() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    ready(&mut app, &ctx, &frame);
+    let path = std::env::temp_dir().join(format!("effectcraft-shot-{}-retry.png", std::process::id()));
+    let _ = std::fs::remove_file(&path);
+    let reply = screenshot_request(&mut app, &ctx, path.to_str(), ShotTarget::Window);
+    let first = issue_shot(&mut app, &ctx, &frame);
+    let size = egui::vec2(1024.0, 640.0);
+    let mut resized = raw(size);
+    pass(&mut app, &ctx, &frame, &mut resized);
+    first.complete(image(800, 480));
+    let _ = tick_with(&mut app, &ctx, &frame, &raw(size));
+    assert!(reply.try_recv().is_err(), "pixels from the old surface epoch are discarded");
+    assert!(!path.exists(), "a stale image is never written");
+    // The retry is issued against the new geometry and the new image is accepted.
+    let second = issue_shot_at(&mut app, &ctx, &frame, size);
+    second.complete(image(1024, 640));
+    let _ = tick_with(&mut app, &ctx, &frame, &raw(size));
+    let value = reply.try_recv().expect("the retried capture replies");
+    assert_eq!(value["ok"], true, "{value}");
+    assert_eq!(value["result"]["width"], 1024);
+    let _ = std::fs::remove_file(&path);
+}
+
+#[test]
+fn screenshot_admission_bounds_requests_and_a_timeout_releases_its_reservation() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    ready(&mut app, &ctx, &frame);
+    let mut replies = Vec::new();
+    for _ in 0..MAX_PENDING_SHOTS {
+        replies.push(screenshot_request(&mut app, &ctx, None, ShotTarget::Rect([0.0, 0.0, 4.0, 4.0])));
+    }
+    let refused = screenshot_request(&mut app, &ctx, None, ShotTarget::Rect([0.0, 0.0, 4.0, 4.0]));
+    let value = refused.try_recv().expect("the fifth request is refused immediately");
+    assert_eq!(value["ok"], false, "{value}");
+    // Every queued request times out on a hidden window that presents no frame; each one
+    // releases its reservation exactly once.
+    app.clock_mut().advance(SCREENSHOT_TIMEOUT_S + 1.0);
+    hidden_tick(&mut app, &ctx, &frame);
+    for reply in replies {
+        let value = reply.try_recv().expect("a timed-out request gets an actionable reply");
+        assert_eq!(value["ok"], false, "{value}");
+        assert!(value["error"].as_str().is_some_and(|e| e.contains("no frame")), "{value}");
+    }
+    assert_eq!(app.shot_bytes, 0);
+    assert!(app.pending_screenshots.is_empty());
+}
+
+#[test]
+fn a_late_callback_after_cancellation_writes_nothing_and_replies_once() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    ready(&mut app, &ctx, &frame);
+    let path = std::env::temp_dir().join(format!("effectcraft-shot-{}-late.png", std::process::id()));
+    let _ = std::fs::remove_file(&path);
+    let reply = screenshot_request(&mut app, &ctx, path.to_str(), ShotTarget::Window);
+    let late = issue_shot(&mut app, &ctx, &frame);
+    app.clock_mut().advance(SCREENSHOT_TIMEOUT_S + 1.0);
+    hidden_tick(&mut app, &ctx, &frame);
+    let timeout = reply.try_recv().expect("the request times out");
+    assert_eq!(timeout["ok"], false, "{timeout}");
+    late.complete(image(800, 480));
+    hidden_tick(&mut app, &ctx, &frame);
+    assert!(reply.try_recv().is_err(), "a late completion sends no second reply");
+    assert!(!path.exists(), "a late completion writes no file");
+    assert_eq!(app.shot_bytes, 0);
+}
+
+/// Every repaint delay requested on `ctx` (what a host uses to wake the app).
+fn wake_requests(ctx: &egui::Context) -> Arc<std::sync::Mutex<Vec<std::time::Duration>>> {
+    let wakes: Arc<std::sync::Mutex<Vec<std::time::Duration>>> = Arc::default();
+    let record = Arc::clone(&wakes);
+    ctx.set_repaint_observer(move |i| record.lock().unwrap_or_else(std::sync::PoisonError::into_inner).push(i.delay));
+    wakes
+}
+
+#[test]
+fn an_issued_capture_schedules_a_wake_up_for_its_deadline() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    ready(&mut app, &ctx, &frame);
+    let reply = screenshot_request(&mut app, &ctx, None, ShotTarget::Window);
+    for _ in 0..SCREENSHOT_SETTLE_PASSES {
+        let mut raw = raw(egui::vec2(800.0, 480.0));
+        pass(&mut app, &ctx, &frame, &mut raw);
+    }
+    app.clock_mut().advance(SCREENSHOT_SETTLE_S + 0.01);
+    // Record the repaint requests of the tick that issues the capture only.
+    let wakes = wake_requests(&ctx);
+    let out = tick_with(&mut app, &ctx, &frame, &raw(egui::vec2(800.0, 480.0)));
+    assert_eq!(shot_callbacks(&out).len(), 1, "the settled capture is issued once");
+    let delays = wakes.lock().unwrap_or_else(std::sync::PoisonError::into_inner).clone();
+    // The deadline is 8 s after admission; the capture was issued ~0.31 s in, so the app must
+    // ask for a wake-up close to that timeout, not only for the next paint.
+    let deadline_wake = delays.iter().any(|d| d.as_secs_f64() > 7.0 && d.as_secs_f64() <= SCREENSHOT_TIMEOUT_S);
+    assert!(deadline_wake, "an issued capture asks the host to wake for its timeout: {delays:?}");
+    // The callback never arrives (a hidden window or a display asleep). The host wakes at the
+    // requested delay; without this wake-up the timeout below could never be evaluated.
+    app.clock_mut().advance(SCREENSHOT_TIMEOUT_S + 1.0);
+    hidden_tick(&mut app, &ctx, &frame);
+    let value = reply.try_recv().expect("the deadline wake-up produces the timeout reply");
+    assert_eq!(value["ok"], false, "{value}");
+    assert!(value["error"].as_str().is_some_and(|e| e.contains("no frame")), "{value}");
+    assert_eq!(app.shot_bytes, 0);
+    assert!(app.pending_screenshots.is_empty());
+}
+
+#[test]
+fn a_downscaled_capture_is_cropped_with_the_images_own_scale() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    let geom = ready(&mut app, &ctx, &frame);
+    assert_eq!((geom.rect.width(), geom.rect.height(), geom.ppp), (800.0, 480.0, 1.0));
+    // The adapter-limit fit (E2) returned half the requested pixels. Left red, right blue.
+    let fitted =
+        Arc::new(egui::ColorImage::new([400, 240], (0..400 * 240).map(|i| if i % 400 < 200 { egui::Color32::RED } else { egui::Color32::BLUE }).collect()));
+    let dir = std::env::temp_dir();
+    for (name, crop, want) in [("left", [0.0, 0.0, 400.0, 240.0], egui::Color32::RED), ("right", [400.0, 0.0, 400.0, 240.0], egui::Color32::BLUE)] {
+        let path = dir.join(format!("effectcraft-shot-{}-scale-{name}.png", std::process::id()));
+        let _ = std::fs::remove_file(&path);
+        let reply = screenshot_request(&mut app, &ctx, path.to_str(), ShotTarget::Rect(crop));
+        let cb = issue_shot(&mut app, &ctx, &frame);
+        cb.complete(Arc::clone(&fitted));
+        hidden_tick(&mut app, &ctx, &frame);
+        let value = reply.try_recv().expect("the downscaled capture replies");
+        assert_eq!(value["ok"], true, "{value}");
+        assert_eq!(value["result"]["width"], 200, "{value}");
+        assert_eq!(value["result"]["height"], 120, "{value}");
+        let png = std::fs::read(&path).expect("the PNG is written");
+        let decoded = image::load_from_memory(&png).expect("our PNG decodes").to_rgba8();
+        assert_eq!((decoded.width(), decoded.height()), (200, 120), "{value}");
+        let px = decoded.get_pixel(100, 60).0;
+        assert!(px[0] == want.r() && px[1] == want.g() && px[2] == want.b(), "{name}: {px:?} is not from its half of the fitted image");
+        let _ = std::fs::remove_file(&path);
+    }
+}
+
+#[test]
+fn a_capture_before_any_pass_never_uses_the_window_frame_rect() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    // Only the outer (title bar included) rectangle is known: it is not the captured surface.
+    let outer = egui::Rect::from_min_size(egui::pos2(0.0, -30.0), egui::vec2(800.0, 510.0));
+    let mut raw = egui::RawInput::default();
+    raw.viewports.insert(egui::ViewportId::ROOT, egui::ViewportInfo { outer_rect: Some(outer), ..Default::default() });
+    let _ = tick_with(&mut app, &ctx, &frame, &raw);
+    let (tx, reply) = std::sync::mpsc::channel();
+    app.admit_screenshot(&ctx, None, ShotTarget::Window, tx);
+    let value = reply.try_recv().expect("the request is answered now");
+    assert_eq!(value["ok"], false, "{value}");
+    assert!(value["error"].as_str().is_some_and(|e| e.contains("geometry is not known")), "{value}");
+    assert!(app.pending_screenshots.is_empty(), "nothing was reserved against the wrong rectangle");
+    assert_eq!(app.shot_bytes, 0);
+    assert!(app.want_paint, "the pass that records the geometry is requested");
+}
+
+#[test]
+fn an_element_that_moves_while_the_ui_settles_is_captured_where_it_is() {
+    let ctx = egui::Context::default();
+    let frame = eframe::Frame::_new_kittest();
+    let mut app = app_with_comp();
+    let geom = ready(&mut app, &ctx, &frame);
+    // Any registered panel: the crop follows this element's rectangle.
+    let panel = app.auto.previous.iter().chain(app.auto.elements.iter()).find(|e| e.id.starts_with("panel.")).map(|e| e.id.clone());
+    let panel = panel.expect("a dock panel is on screen after a completed pass");
+    let reply = screenshot_request(&mut app, &ctx, None, ShotTarget::Id(panel.clone()));
+    for _ in 0..SCREENSHOT_SETTLE_PASSES {
+        let mut raw = raw(egui::vec2(800.0, 480.0));
+        pass(&mut app, &ctx, &frame, &mut raw);
+    }
+    // The panel moves after its last draw: the crop must follow it, not the admission rect.
+    let moved = [40.0, 30.0, 300.0, 200.0];
+    for list in [&mut app.auto.previous, &mut app.auto.elements] {
+        if let Some(e) = list.iter_mut().find(|e| e.id == panel) {
+            e.rect = moved;
+        }
+    }
+    app.clock_mut().advance(SCREENSHOT_SETTLE_S + 0.01);
+    let out = tick_with(&mut app, &ctx, &frame, &raw(egui::vec2(800.0, 480.0)));
+    assert_eq!(shot_callbacks(&out).len(), 1, "the settled capture is issued once");
+    let crop = app.pending_screenshots.first().and_then(|s| s.crop).expect("the element crop is resolved at issuance");
+    assert!((crop[0] - (moved[0] - geom.rect.min.x)).abs() < 0.01, "{crop:?}");
+    assert!((crop[1] - (moved[1] - geom.rect.min.y)).abs() < 0.01, "{crop:?}");
+    assert!((crop[2] - moved[2]).abs() < 0.01 && (crop[3] - moved[3]).abs() < 0.01, "{crop:?}");
+    // Let it complete and reply, so the request does not outlive the test.
+    if let Some(cb) = shot_callbacks(&out).into_iter().next() {
+        cb.complete(image(800, 480));
+    }
+    hidden_tick(&mut app, &ctx, &frame);
+    let value = reply.try_recv().expect("the capture replies");
+    assert_eq!(value["ok"], true, "{value}");
+    assert_eq!((value["result"]["width"].as_u64(), value["result"]["height"].as_u64()), (Some(300), Some(200)), "{value}");
+}
diff --git a/crates/ui-egui/src/menus.rs b/crates/ui-egui/src/menus.rs
index 4f6bacbc3..cb28b0bcd 100644
--- a/crates/ui-egui/src/menus.rs
+++ b/crates/ui-egui/src/menus.rs
@@ -12,6 +12,27 @@ use crate::dock::{PanelKind, WorkspaceExt as _};
 use crate::state::{Resolution, Tool};
 use effectcraft_engine::menus::{MenuEntry, MenuNode};
 
+mod bar;
+mod commands;
+mod entries;
+mod frontend;
+mod invoke;
+mod shortcuts;
+
+pub use bar::menu_bar;
+pub(crate) use bar::{dyn_ctx, entry_for, menu_contents, submenu_at};
+pub use commands::UI_COMMANDS;
+pub use entries::{MenuItem, menu_items, menus};
+pub(crate) use entries::{entry_checked, entry_enabled, entry_label, entry_shortcut, menu_choice, panel_shown};
+pub use frontend::frontend;
+#[cfg(test)]
+use frontend::zoom_step;
+pub(crate) use frontend::{dialog_answered, run_engine};
+pub use invoke::{invoke, panel_command_id, reveal};
+#[cfg(test)]
+use shortcuts::modifiers_at_start;
+pub use shortcuts::{Binding, bindings, chord_matches, forwardable_during_text_edit, handle_shortcuts, handle_tab_shortcut, parse_shortcut, shortcut_text};
+
 pub struct UiCommand {
     pub id: &'static str,
     pub label: &'static str,
@@ -19,2730 +40,5 @@ pub struct UiCommand {
     pub shortcut: Option<&'static str>,
 }
 
-macro_rules! uic {
-    ($id:literal, $label:literal, [$($m:literal),*], $sc:expr) => {
-        UiCommand { id: $id, label: $label, menu: &[$($m),*], shortcut: $sc }
-    };
-}
-
-/// UI-only commands (not in the AE menus; shortcuts and the command palette).
-pub const UI_COMMANDS: &[UiCommand] = &[
-    uic!("window.dockAction", "Docking Action", [], None),
-    uic!("playback.ramPreview", "Preview (Numpad 0)", [], Some("Num0")),
-    uic!("playback.preview.shiftSpacebar", "Preview (Shift+Spacebar)", [], Some("Shift+Space")),
-    uic!("playback.preview.shiftNumpad0", "Preview (Shift+Numpad 0)", [], Some("Shift+Num0")),
-    uic!("playback.preview.altNumpad0", "Preview (Alt+Numpad 0)", [], Some("Alt+Num0")),
-    uic!("playback.stop", "Stop", [], None),
-    uic!("view.fit", "Fit", [], Some("Shift+/")),
-    uic!("view.actualSize", "100%", [], Some("/")),
-    uic!("view.fitUpTo100", "Fit up to 100%", [], Some("Alt+/")),
-    uic!("view.nextItem", "Next Composition in Viewer", [], Some("Shift+.")),
-    uic!("view.previousItem", "Previous Composition in Viewer", [], Some("Shift+,")),
-    uic!("viewer.nudge.up", "Move Selected Layers Up 1 Pixel at Current Magnification", [], Some("ArrowUp")),
-    uic!("viewer.nudge.down", "Move Selected Layers Down 1 Pixel at Current Magnification", [], Some("ArrowDown")),
-    uic!("viewer.nudge.left", "Move Selected Layers Left 1 Pixel at Current Magnification", [], Some("ArrowLeft")),
-    uic!("viewer.nudge.right", "Move Selected Layers Right 1 Pixel at Current Magnification", [], Some("ArrowRight")),
-    uic!("viewer.nudge.up10", "Move Selected Layers Up 10 Pixels at Current Magnification", [], Some("Shift+ArrowUp")),
-    uic!("viewer.nudge.down10", "Move Selected Layers Down 10 Pixels at Current Magnification", [], Some("Shift+ArrowDown")),
-    uic!("viewer.nudge.left10", "Move Selected Layers Left 10 Pixels at Current Magnification", [], Some("Shift+ArrowLeft")),
-    uic!("viewer.nudge.right10", "Move Selected Layers Right 10 Pixels at Current Magnification", [], Some("Shift+ArrowRight")),
-    uic!("view.safeMargins", "Title/Action Safe", [], Some("'")),
-    uic!("view.transparencyGrid", "Transparency Grid", [], None),
-    uic!("view.fastPreviews", "Fast Previews", [], None),
-    uic!("view.theme.toggle", "Next Appearance Mode", [], None),
-    uic!("view.theme.dark", "Theme: Dark", [], None),
-    uic!("view.theme.darker", "Theme: Darker", [], None),
-    uic!("view.theme.light", "Theme: Light", [], None),
-    uic!("timeline.zoomIn", "Zoom In Time", [], Some("=")),
-    uic!("timeline.zoomOut", "Zoom Out Time", [], Some("-")),
-    uic!("timeline.zoomFit", "Zoom to Fit Comp", [], Some("Shift+;")),
-    uic!("timeline.scrollToTime", "Scroll to Current Time", [], Some("D")),
-    uic!("timeline.scrollToLayer", "Scroll Topmost Selected Layer to Top", [], Some("X")),
-    uic!("timeline.parentColumn", "Show/Hide Parent Column", [], Some("Shift+F4")),
-    uic!("timeline.zoomFrameToggle", "Zoom In to Frame Level / Out to the Whole Comp", [], Some(";")),
-    uic!("timeline.graphEditor", "Graph Editor", [], Some("Shift+F3")),
-    uic!("timeline.switchesModes", "Toggle Switches / Modes", [], Some("F4")),
-    uic!("timeline.workAreaBegin", "Set Work Area Begin", [], Some("B")),
-    uic!("timeline.workAreaEnd", "Set Work Area End", [], Some("N")),
-    uic!("timeline.moveInToTime", "Move Layer In Point to Current Time", [], Some("[")),
-    uic!("timeline.moveOutToTime", "Move Layer Out Point to Current Time", [], Some("]")),
-    uic!("timeline.trimInToTime", "Trim Layer In Point to Current Time", [], Some("Alt+[")),
-    uic!("timeline.trimOutToTime", "Trim Layer Out Point to Current Time", [], Some("Alt+]")),
-    uic!("timeline.reveal.position", "Reveal Position", [], Some("P")),
-    uic!("timeline.reveal.scale", "Reveal Scale", [], Some("S")),
-    uic!("timeline.reveal.rotation", "Reveal Rotation", [], Some("R")),
-    uic!("timeline.reveal.opacity", "Reveal Opacity", [], Some("T")),
-    uic!("timeline.reveal.anchor", "Reveal Anchor Point", [], Some("A")),
-    uic!("timeline.reveal.effects", "Reveal Effects", [], Some("E")),
-    uic!("timeline.reveal.masks", "Reveal Masks", [], Some("M")),
-    uic!("timeline.reveal.feather", "Reveal Mask Feather", [], Some("F")),
-    uic!("timeline.reveal.levels", "Reveal Audio Levels (press twice: Waveform)", [], Some("L")),
-    uic!("timeline.reveal.timeRemap", "Reveal Time Remap", [], None),
-    uic!("timeline.reveal.expressions", "Reveal Expressions", [], None),
-    uic!("timeline.reveal.maskOpacity", "Reveal Mask Opacity", [], None),
-    uic!("timeline.reveal.maskPath", "Reveal Mask Path", [], None),
-    uic!("timeline.reveal.material", "Reveal Material Options", [], None),
-    uic!("timeline.reveal.paint", "Reveal Paint, Roto Brush and Puppet", [], None),
-    uic!("timeline.reveal.selected", "Reveal Selected Properties", [], None),
-    uic!("timeline.reveal.missingEffects", "Reveal Missing Effects", [], None),
-    uic!("timeline.reveal.waveform", "Reveal Audio Waveform", [], None),
-    uic!("timeline.revealAdd.position", "Add Position to Revealed Properties", [], Some("Shift+P")),
-    uic!("timeline.revealAdd.scale", "Add Scale to Revealed Properties", [], Some("Shift+S")),
-    uic!("timeline.revealAdd.rotation", "Add Rotation to Revealed Properties", [], Some("Shift+R")),
-    uic!("timeline.revealAdd.opacity", "Add Opacity to Revealed Properties", [], Some("Shift+T")),
-    uic!("timeline.revealAdd.anchor", "Add Anchor Point to Revealed Properties", [], Some("Shift+A")),
-    uic!("timeline.revealAdd.effects", "Add Effects to Revealed Properties", [], Some("Shift+E")),
-    uic!("timeline.revealAdd.masks", "Add Masks to Revealed Properties", [], Some("Shift+M")),
-    uic!("timeline.revealAdd.feather", "Add Mask Feather to Revealed Properties", [], Some("Shift+F")),
-    uic!("timeline.revealAdd.levels", "Add Audio Levels to Revealed Properties", [], Some("Shift+L")),
-    uic!("timeline.revealAdd.animated", "Add Animated Properties to Revealed Properties", [], Some("Shift+U")),
-    uic!("timeline.column", "Show/Hide Timeline Column", [], None),
-    uic!("timeline.sourceName", "Source Name / Layer Name", [], None),
-    uic!("timeline.search", "Search Timeline", [], None),
-    uic!("flowchart.options", "Flowchart Options", [], None),
-    uic!("flowchart.graph", "Flowchart Graph", [], None),
-    uic!("timeline.collapseAll", "Collapse All", [], None),
-    uic!("timeline.twirlSelected", "Twirl Selected Layers Open / Closed", [], Some("Cmd+`")),
-    uic!("timeline.keyAt.anchor", "Add or Remove Anchor Point Keyframe", [], Some("Alt+Shift+A")),
-    uic!("timeline.keyAt.position", "Add or Remove Position Keyframe", [], Some("Alt+Shift+P")),
-    uic!("timeline.keyAt.scale", "Add or Remove Scale Keyframe", [], Some("Alt+Shift+S")),
-    uic!("timeline.keyAt.rotation", "Add or Remove Rotation Keyframe", [], Some("Alt+Shift+R")),
-    uic!("timeline.keyAt.opacity", "Add or Remove Opacity Keyframe", [], Some("Alt+Shift+T")),
-    uic!("tool.selection", "Selection Tool", [], Some("V")),
-    uic!("tool.hand", "Hand Tool", [], Some("H")),
-    uic!("tool.zoom", "Zoom Tool", [], Some("Z")),
-    uic!("tool.orbit", "Orbit Tool", [], Some("1")),
-    uic!("tool.panCamera", "Pan Camera Tool", [], Some("2")),
-    uic!("tool.dolly", "Dolly Tool", [], Some("3")),
-    uic!("tool.camera", "Camera Tools", [], Some("C")),
-    uic!("tool.rotate", "Rotation Tool", [], Some("W")),
-    uic!("tool.panBehind", "Pan Behind Tool", [], Some("Y")),
-    uic!("tool.shape", "Shape Tools", [], Some("Q")),
-    uic!("tool.pen", "Pen Tool", [], Some("G")),
-    uic!("tool.type", "Type Tools", [], Some("Cmd+T")),
-    uic!("tool.brush", "Brush Tools", [], Some("Cmd+B")),
-    uic!("tool.rotoBrush", "Roto Brush & Refine Edge Tools", [], Some("Alt+W")),
-    uic!("tool.puppet", "Puppet Tools", [], Some("Cmd+P")),
-    uic!("app.newComp", "New Composition...", [], None),
-    uic!("app.compSettings", "Composition Settings...", [], None),
-    uic!("app.solidSettings", "New Solid...", [], None),
-    uic!("app.home", "Home", [], None),
-    uic!("markers.dialog", "Marker Settings...", [], None),
-    uic!("window.maximizePanel", "Maximize Panel Under Pointer", [], Some("`")),
-    uic!("window.maximizeApp", "Maximize or Restore Application Window", [], Some("Cmd+\\")),
-    uic!("window.toggleCompTimeline", "Switch Between Composition and Timeline Panel", [], Some("\\")),
-    uic!("window.nextPanel", "Next Panel in Frame", [], Some("Alt+Shift+.")),
-    uic!("window.previousPanel", "Previous Panel in Frame", [], Some("Alt+Shift+,")),
-    uic!("window.closeAll", "Close Panel or All Viewers", [], Some("Cmd+Shift+W")),
-    uic!("window.dockPanel", "Dock Panel", [], None),
-    uic!("window.floatPanel", "Undock Panel", [], None),
-    uic!("window.closePanel", "Close Panel", [], None),
-    uic!("window.panelWindow", "Move Panel to New Window", [], None),
-];
-
-pub fn panel_command_id(p: PanelKind) -> String {
-    format!("window.panel.{}", p.id())
-}
-
-/// The reveal shortcuts (P, S, R, T, A, E, M, F, L…). `add` (Shift+key) adds the property to
-/// (or removes it from) those already revealed instead of replacing them.
-pub fn reveal(app: &mut EffectcraftApp, kind: &str, now: f64, add: bool) {
-    // The double-press shortcuts: the same key again within 0.6 s reveals its second set (LL
-    // Waveform, TT Mask Opacity, MM all mask properties, EE Expressions, RR Time Remap, AA
-    // Material Options, PP paint / Roto Brush / Puppet, SS selected properties, FF missing
-    // effects). A single M shows Mask Path.
-    let double = |k: &str| -> Option<&'static str> {
-        Some(match k {
-            "levels" => "waveform",
-            "opacity" => "maskOpacity",
-            "masks" => "masks",
-            "effects" => "expressions",
-            "rotation" => "timeRemap",
-            "anchor" => "material",
-            "position" => "paint",
-            "scale" => "selected",
-            "feather" => "missingEffects",
-            _ => return None,
-        })
-    };
-    let pressed = kind;
-    // (With Shift a second press removes the property again instead.)
-    let again = !add && matches!(app.last_reveal.take(), Some((k, t)) if k == pressed && now - t < 0.6);
-    app.last_reveal = Some((if again { String::new() } else { pressed.to_string() }, now));
-    let kind = match (again, double(pressed)) {
-        (true, Some(d)) => {
-            // The second press replaces what the first one revealed.
-            let first = if pressed == "masks" { "maskPath" } else { pressed };
-            app.ui.timeline.reveal.retain(|k| k != first);
-            d
-        }
-        _ if pressed == "masks" => "maskPath",
-        _ => pressed,
-    };
-    let targets = reveal_targets(app);
-    let tl = &mut app.ui.timeline;
-    let present = tl.reveal.iter().any(|k| k == kind);
-    let mut kinds = tl.reveal.clone();
-    if add {
-        if present {
-            kinds.retain(|k| k != kind);
-        } else {
-            kinds.retain(|k| k != "props" || !tl.reveal_props.is_empty());
-            kinds.push(kind.to_string());
-        }
-    } else if present && kinds.len() == 1 {
-        kinds.clear();
-    } else {
-        kinds = vec![kind.to_string()];
-    }
-    tl.apply_reveal(&targets, kinds.clone());
-    crate::panels::timeline::open_revealed(app, &targets, &kinds);
-}
-
-/// Show Time Remap on the layers of a `layer.enableTimeRemap` (`layers` by id, else the
-/// selected ones) that have it now.
-fn reveal_time_remap(app: &mut EffectcraftApp, params: &Value) {
-    let asked: Vec<u64> = match params.get("layers").and_then(Value::as_array) {
-        Some(a) => a.iter().filter_map(Value::as_u64).collect(),
-        None => app.session.state.selected_layers.iter().map(|l| l.0).collect(),
-    };
-    let Some(comp) = app.session.active_comp() else { return };
-    let layers: Vec<u64> = comp.layers.iter().filter(|l| asked.contains(&l.id.0) && l.props.get("timeRemap").is_some()).map(|l| l.id.0).collect();
-    if !layers.is_empty() {
-        app.ui.timeline.apply_reveal(&layers, vec!["timeRemap".into()]);
-    }
-}
-
-/// After Alt+Shift+P (A, S, R, T) the Timeline shows the property on each layer it keyed, as in
-/// After Effects: added to what a reveal shortcut shows, else with the layer's Transform twirled
-/// open, else alone like P.
-fn reveal_keyed(app: &mut EffectcraftApp, keyed: &Value, kind: &str) {
-    let layers: std::collections::BTreeSet<u64> = keyed.as_array().into_iter().flatten().filter_map(|k| k.get("layer").and_then(Value::as_u64)).collect();
-    let Some(comp) = app.session.active_comp() else { return };
-    let tl = &mut app.ui.timeline;
-    for id in layers {
-        let shown = tl.layer_reveal.get(&id).filter(|k| !k.is_empty()).cloned();
-        match shown {
-            Some(mut kinds) => {
-                if !kinds.iter().any(|k| k == kind) {
-                    kinds.push(kind.to_string());
-                    tl.layer_reveal.insert(id, kinds);
-                }
-            }
-            None if tl.open_layers.contains(&id) => {
-                if let Some(tr) = comp.layer(effectcraft_engine::project::LayerId(id)).and_then(|l| l.transform()) {
-                    tl.open_groups.insert(tr.uid);
-                }
-            }
-            None => {
-                tl.open_layers.insert(id);
-                tl.layer_reveal.insert(id, vec![kind.to_string()]);
-            }
-        }
-    }
-}
-
-/// The layers a reveal shortcut acts on: the selected ones, else every layer of the active comp.
-fn reveal_targets(app: &EffectcraftApp) -> Vec<u64> {
-    if app.session.state.selected_layers.is_empty() {
-        app.session.active_comp().map(|c| c.layers.iter().map(|l| l.id.0).collect()).unwrap_or_default()
-    } else {
-        app.session.state.selected_layers.iter().map(|l| l.0).collect()
-    }
-}
-
-/// The arrow keys nudge the selected layers 1 pixel at the viewer's magnification (`up`,
-/// `down`, `left`, `right`), 10 with Shift (`up10`…), as After Effects does, so zoomed in
-/// they move by fractions of a comp pixel. From any panel except Project (which owns the
-/// arrow keys for its own keyboard navigation, #961); not while typing, with a dialog or
-/// menu open. With mask points selected the arrows move the points instead (#1288).
-fn nudge(app: &mut EffectcraftApp, ctx: &egui::Context, dir: &str) -> Result<Value, String> {
-    let (side, n) = match dir.strip_suffix("10") {
-        Some(side) => (side, 10.0),
-        None => (dir, 1.0),
-    };
-    let (x, y) = match side {
-        "up" => (0.0, -n),
-        "down" => (0.0, n),
-        "left" => (-n, 0.0),
-        "right" => (n, 0.0),
-        _ => return Err(format!("unknown nudge `{dir}`")),
-    };
-    let st = &app.session.state;
-    if app.ui.focused == PanelKind::Project || (st.selected_layers.is_empty() && st.selected_vertices.is_empty()) || st.text_edit.is_some() {
-        return Ok(Value::Null);
-    }
-    // Screen pixels per comp pixel.
-    let zoom = (app.ui.viewer.zoom.unwrap_or_else(|| crate::panels::viewer::last_fit(ctx)) * ctx.pixels_per_point()) as f64;
-    let k = if zoom.is_finite() && zoom > 1e-6 { 1.0 / zoom } else { 1.0 };
-    if let Some(layer) = st.selected_vertices.first().map(|v| v.layer) {
-        let d = vertex_delta(app, layer, [x * k, y * k]);
-        return run_engine(app, ctx, "mask.moveVertices", json!({"delta": d}));
-    }
-    run_engine(app, ctx, "layer.nudge", json!({"x": x * k, "y": y * k}))
-}
-
-/// A comp-space step `d` in the layer space of `layer`, where mask points live. Like a drag of
-/// the points in the viewer, every selected point takes the first one's layer space.
-fn vertex_delta(app: &EffectcraftApp, layer: effectcraft_engine::project::LayerId, d: [f64; 2]) -> [f64; 2] {
-    use effectcraft_engine::geom::vec2;
-    let s = &app.session;
-    let (Some(cid), Some(comp)) = (s.active_comp_id(), s.active_comp()) else { return d };
-    let Some(l) = comp.layer(layer) else { return d };
-    let ectx = effectcraft_engine::render::EvalCtx { project: &s.project, comp_id: cid, comp, time: s.time(), expr: s.expr.as_deref(), footage: None };
-    let (l2c, _) = crate::panels::viewer::l2c(&ectx, l);
-    l2c.inverse().map_or(d, |inv| {
-        let v = inv.apply_vec(vec2(d[0], d[1]));
-        [v.x, v.y]
-    })
-}
-
-fn no_params(p: &Value) -> bool {
-    p.as_object().is_none_or(|m| m.is_empty())
-}
-
-/// `{"comp": id}` and nothing else: Composition Settings opens on that comp instead of
-/// applying no settings to it.
-fn only_comp(p: &Value) -> Option<effectcraft_engine::project::ItemId> {
-    let m = p.as_object().filter(|m| m.len() == 1)?;
-    m.get("comp")?.as_u64().map(effectcraft_engine::project::ItemId)
-}
-
-/// Execute a UI or engine command by id.
-pub fn invoke(app: &mut EffectcraftApp, ctx: &egui::Context, id: &str, params: Value) -> Result<Value, String> {
-    if matches!(id, "effects.copyPresetsFolderPath" | "mediaBrowser.copySourcePath") {
-        return frontend(app, ctx, id, params);
-    }
-    // Layer ▸ New ▸ Text (menu, shortcut, context menus) puts an insertion point in the centre of
-    // the comp, as After Effects does, so typing goes into Source Text rather than running
-    // shortcuts (#866). `engine.execute` keeps the headless default.
-    if id == "layer.newText" && no_params(&params) {
-        return run_engine(app, ctx, id, json!({"text": "", "edit": true}));
-    }
-    // A new folder (File ▸ New, its shortcut, the Project panel's button and context menu) opens
-    // with its name ready to type, as in After Effects (#1658). The command selects it.
-    // `engine.execute` keeps the headless default.
-    if id == "project.newFolder" && no_params(&params) {
-        let r = run_engine(app, ctx, id, params);
-        if r.is_ok() {
-            app.show_panel(PanelKind::Project);
-            crate::panels::project::begin_rename(app, ctx);
-        }
-        return r;
-    }
-    // The Project-panel focus redirects apply only while no text edit is open: creating a text
-    // layer leaves focus on Project while the insertion point lives in the comp, so during an
-    // edit these commands address the text context — redirected, Deselect All would clear a
-    // project selection the user is not looking at and silently swallow the edit's own end.
-    if no_params(&params) && app.ui.focused == PanelKind::Project && app.session.state.text_edit.is_none() {
-        match id {
-            "edit.duplicate" => return run_engine(app, ctx, "project.duplicate", json!({})),
-            "edit.selectAll" => {
-                let items: Vec<u64> = crate::panels::project::visible_rows(app)
-                    .into_iter()
-                    .filter(|(id, _)| app.ui.project_search.is_empty() || app.session.project.item(*id).is_some_and(|it| !it.is_folder()))
-                    .map(|(id, _)| id.0)
-                    .collect();
-                return run_engine(app, ctx, "project.select", json!({"items":items}));
-            }
-            "edit.deselectAll" => return run_engine(app, ctx, "project.select", json!({"items":[]})),
-            "edit.cut" | "edit.copy" | "edit.paste" | "edit.copyWithPropertyLinks" | "edit.copyWithRelativePropertyLinks" | "edit.copyExpressionOnly" => {
-                return Err("Project clipboard actions are not supported yet".into());
-            }
-            _ => {}
-        }
-    }
-    // Edit ▸ Paste with SVG markup on the system clipboard pastes it as a shape layer (After
-    // Effects 26.3). Copying in the app replaces the system clipboard with a note naming what
-    // was copied, so SVG there was copied after anything copied in the app.
-    if id == "edit.paste" && no_params(&params) && app.session.state.text_edit.is_none() {
-        let text = ctx.data_mut(|d| d.remove_temp::<String>(system_paste_id())).or_else(|| app.hooks.clipboard_text.as_ref().and_then(|f| f()));
-        if let Some(svg) = text.filter(|t| effectcraft_engine::vector::is_svg_text(t)) {
-            return run_engine(app, ctx, "edit.pasteSvg", json!({"svg": svg}));
-        }
-    }
-    // Clear follows panel focus, including the Edit menu and keyboard shortcut.
-    if id == "edit.clear" && params.as_object().is_some_and(|p| p.is_empty()) && app.ui.focused == PanelKind::Project {
-        // Through `invoke`, so deleting items that compositions use still asks first (M3.16).
-        return invoke(app, ctx, "project.delete", json!({}));
-    }
-    if id == "edit.clear" && params.as_object().is_some_and(|p| p.is_empty()) && app.ui.focused == PanelKind::RenderQueue {
-        let selected = ctx.data(|d| d.get_temp::<(Vec<u64>, Option<u64>)>(egui::Id::unique("rq-ui"))).and_then(|(_, id)| id);
-        return match selected {
-            Some(item) => run_engine(app, ctx, "renderQueue.remove", json!({"item": item})),
-            None => Err("select a Render Queue item first".into()),
-        };
-    }
-    // Shift+Delete deletes the Project panel's selection without asking; it does nothing in the
-    // other panels.
-    if id == "project.deleteWithoutConfirmation" {
-        if app.ui.focused != PanelKind::Project {
-            return Ok(Value::Null);
-        }
-        return crate::panels::delete_items::delete_confirmed(app, ctx, json!({}));
-    }
-    let now = app.now();
-    // Closing a modified project asks to save it first; the command runs once answered.
-    if crate::panels::unsaved::guard(app, id, &params) {
-        return Ok(json!({"dialog": "unsavedChanges"}));
-    }
-    // Deleting Project items that compositions use asks first, as in After Effects.
-    if crate::panels::delete_items::guard(app, id, &params) {
-        return Ok(json!({"dialog": "deleteItems"}));
-    }
-    // J / K and Select All Keyframes act on what the Timeline shows (its revealed properties).
-    if matches!(id, "time.nextKey" | "time.previousKey" | "keys.selectAll")
-        && ["visible", "layers", "layer", "prop"].iter().all(|k| params.get(*k).is_none())
-        && let Some(c) = app.session.active_comp_arc()
-    {
-        let mut p = if params.is_object() { params.clone() } else { json!({}) };
-        p["visible"] = json!(crate::panels::timeline::visible_props(app, &c));
-        return run_engine(app, ctx, id, p);
-    }
-    // New Camera/Light and Camera/Light Settings without parameters open their dialogs.
-    if crate::panels::dialogs_3d::route(app, id, &params)? {
-        return Ok(Value::Null);
-    }
-    // New 3D Primitive without parameters opens its dialog.
-    if crate::panels::primitive_dialog::route(app, id, &params)? {
-        return Ok(Value::Null);
-    }
-    // Layer Settings on a solid, adjustment layer or null opens its settings dialog.
-    if crate::panels::dialogs::route_layer_settings(app, id, &params)? {
-        return Ok(Value::Null);
-    }
-    // Layer ▸ Layer Styles ▸ <style> from the menu adds the style and opens the dialog on it.
-    if crate::panels::layer_styles_dialog::route(app, id, &params)? {
-        return Ok(Value::Null);
-    }
-    // Shared docking: `window.dockAction`, craft-ui's `window.panel.*` commands, `ui.dock`,
-    // `ui.dock.reset` and `window.panelWindow`.
-    if let Some(result) = crate::dock_ui::route(app, ctx, id, &params) {
-        return result;
-    }
-    // Legacy per-panel / per-workspace ids (`window.panel.Project`, `window.workspace.default`).
-    if let Some(rest) = id.strip_prefix("window.panel.") {
-        return frontend(app, ctx, "window.panel", json!({"panel": rest}));
-    }
-    if let Some(ws) = id.strip_prefix("window.workspace.") {
-        if ws == "reset" {
-            return frontend(app, ctx, "window.resetWorkspace", json!({}));
-        }
-        return frontend(app, ctx, "window.workspace", json!({"name": ws}));
-    }
-    if let Some(t) = id.strip_prefix("tool.") {
-        // C cycles through the camera tools.
-        if t == "camera" {
-            let tools = [Tool::Orbit, Tool::PanCamera, Tool::Dolly];
-            let next = match tools.iter().position(|x| *x == app.ui.tool) {
-                Some(i) => tools[(i + 1) % tools.len()],
-                None => Tool::Orbit,
-            };
-            app.ui.tool = next;
-            return Ok(json!({"tool": next}));
-        }
-        // Slot shortcuts cycle through the slot's tools.
-        let slot = match t {
-            "shape" => Some(8),
-            "pen" => Some(9),
-            "type" => Some(10),
-            "brush" => Some(11),
-            "rotoBrush" => Some(14),
-            "puppet" => Some(15),
-            _ => None,
-        };
-        if let Some(si) = slot {
-            let tools: Vec<Tool> = match si {
-                11 => vec![Tool::Brush, Tool::Clone, Tool::Eraser],
-                _ => crate::state::Tool::SLOTS[si].to_vec(),
-            };
-            let cur = tools.iter().position(|x| *x == app.ui.tool);
-            let next = match cur {
-                Some(i) => tools[(i + 1) % tools.len()],
-                None => app.ui.slot_tools.get(si).copied().filter(|x| tools.contains(x)).unwrap_or(tools[0]),
-            };
-            app.ui.tool = next;
-            if si < app.ui.slot_tools.len() && si != 11 {
-                app.ui.slot_tools[si] = next;
-            }
-            return Ok(json!({"tool": next}));
-        }
-        let tool = Tool::from_name(t).ok_or_else(|| format!("unknown tool `{t}`"))?;
-        app.ui.tool = tool;
-        return Ok(json!({"tool": tool}));
-    }
-    if let Some(dir) = id.strip_prefix("viewer.nudge.") {
-        return nudge(app, ctx, dir);
-    }
-    if let Some(k) = id.strip_prefix("timeline.reveal.") {
-        if k == "animated" {
-            return run_engine(app, ctx, "anim.reveal", json!({"kind": "keyframes"}));
-        }
-        reveal(app, k, now, false);
-        return Ok(Value::Null);
-    }
-    if let Some(k) = id.strip_prefix("timeline.keyAt.") {
-        let r = run_engine(app, ctx, "keys.toggleTransform", json!({"prop": k}))?;
-        reveal_keyed(app, &r, k);
-        return Ok(r);
-    }
-    if let Some(k) = id.strip_prefix("timeline.revealAdd.") {
-        reveal(app, k, now, true);
-        return Ok(json!({"revealed": app.ui.timeline.reveal}));
-    }
-    // U reveals keyframed properties; UU (pressed twice quickly) all modified properties; U
-    // again later hides them.
-    if id == "anim.reveal" && params.get("kind").and_then(Value::as_str) == Some("keyframes") {
-        let last = app.last_reveal.take();
-        app.last_reveal = Some(("keyframes".into(), now));
-        match last {
-            Some((k, t)) if k == "keyframes" && now - t < 0.6 => {
-                return run_engine(app, ctx, "anim.reveal", json!({"kind": "modified"}));
-            }
-            Some((k, _)) if k == "keyframes" && app.ui.timeline.reveal == ["props"] => {
-                let targets = reveal_targets(app);
-                app.ui.timeline.apply_reveal(&targets, vec![]);
-                return Ok(json!({"revealed": 0}));
-            }
-            _ => {}
-        }
-    }
-    // A UI-only command (not in the engine's menus), so `frontend` gets it from here.
-    if id == "window.maximizeApp" {
-        return frontend(app, ctx, id, params);
-    }
-    // Docking: {panel, anchor, zone: center|left|right|top|bottom}, {panel, rect?}, {panel?}.
-    if let Some(op) = id.strip_prefix("window.").filter(|o| matches!(*o, "maximizePanel" | "dockPanel" | "floatPanel" | "closePanel")) {
-        let panel_of = |k: &str| params.get(k).and_then(Value::as_str).map(|s| PanelKind::from_name(s).ok_or(format!("unknown panel `{s}`")));
-        match op {
-            "maximizePanel" => {
-                let p = match panel_of("panel") {
-                    Some(p) => p?,
-                    None => app.panel_at(ctx.pointer_hover_pos()),
-                };
-                app.toggle_maximize(p);
-                return Ok(json!({"maximized": app.ui.maximized}));
-            }
-            "closePanel" => {
-                let p = panel_of("panel").ok_or("closePanel: need `panel`")??;
-                if app.ui.dock.is_open(p) {
-                    app.apply_dock(craft_ui::docking::Action::Close { panel: p })?;
-                }
-                return Ok(Value::Null);
-            }
-            "floatPanel" => {
-                let p = panel_of("panel").ok_or("floatPanel: need `panel`")??;
-                let r = match params.get("rect") {
-                    Some(value) => serde_json::from_value::<[f32; 4]>(value.clone()).map_err(|_| "rect must contain four finite numbers")?,
-                    None => crate::dock_ui::default_float_rect(ctx.content_rect()),
-                };
-                app.apply_dock(craft_ui::docking::Action::Float { panel: p, rect: r }).map_err(|e| format!("can't undock {}: {e}", p.title()))?;
-                return Ok(Value::Null);
-            }
-            _ => {
-                // craft-ui's `window.panel.dock`: zones center/tab, left/right/top/bottom (a split
-                // beside the anchor), above/below; without an anchor a side zone docks along that
-                // edge of the whole workspace.
-                let p = panel_of("panel").ok_or("dockPanel: need `panel`")??;
-                let mut command = json!({"command": "window.panel.dock", "panel": p});
-                if let Some(anchor) = panel_of("anchor") {
-                    command["anchor"] = json!(anchor?);
-                    command["zone"] = json!("center");
-                }
-                if let Some(zone) = params.get("zone") {
-                    let zone = zone.as_str().ok_or("zone: center|tab|left|right|top|bottom|above|below")?.to_ascii_lowercase();
-                    if command.get("anchor").is_some() || zone != "center" {
-                        command["zone"] = json!(zone);
-                    }
-                }
-                if let Some(before) = panel_of("before") {
-                    command["before"] = json!(before?);
-                }
-                let command: craft_ui::docking::DockCommand<PanelKind> =
-                    serde_json::from_value(command).map_err(|e| format!("dockPanel: zone: center|tab|left|right|top|bottom|above|below ({e})"))?;
-                app.run_dock_command(ctx, command).map_err(|e| format!("can't dock {}: {e}", p.title()))?;
-                app.show_panel(p);
-                return Ok(Value::Null);
-            }
-        }
-    }
-    if id == "markers.dialog" {
-        // The Composition/Layer Marker dialog (double-click a marker): {layer?, index}.
-        let index = params.get("index").and_then(Value::as_u64).ok_or("markers.dialog: need `index`")? as usize;
-        let layer = params.get("layer").and_then(Value::as_u64);
-        crate::panels::markers_ui::open_dialog(app, crate::panels::markers_ui::MarkerRef { layer, index })?;
-        return Ok(json!({"dialog": id}));
-    }
-
-    if id == "view.theme.toggle" {
-        app.cycle_appearance(ctx);
-        return Ok(json!({"appearanceMode": app.session.prefs.appearance.appearance_mode}));
-    }
-    if let Some(th) = id.strip_prefix("view.theme.") {
-        let k = crate::theme::ThemeKind::from_name(th).ok_or("unknown theme")?;
-        app.set_theme(ctx, k);
-        return Ok(Value::Null);
-    }
-    let timing = |app: &mut EffectcraftApp, op: &str| app.session.execute("layer.timing", json!({"op": op})).map_err(|e| e.to_string());
-    match id {
-        "playback.ramPreview" => {
-            app.toggle_play_with(now, effectcraft_engine::preview::PreviewShortcut::Numpad0);
-            return Ok(json!({"playing": app.playback.playing}));
-        }
-        "playback.preview.shiftSpacebar" | "playback.preview.shiftNumpad0" | "playback.preview.altNumpad0" => {
-            let sc = effectcraft_engine::preview::PreviewShortcut::parse(id.trim_start_matches("playback.preview.")).ok_or("unknown preview shortcut")?;
-            app.toggle_play_with(now, sc);
-            return Ok(json!({"playing": app.playback.playing}));
-        }
-        "playback.stop" => {
-            app.stop();
-            return Ok(Value::Null);
-        }
-        // The focused Layer panel has its own magnification; otherwise the Composition viewer.
-        "view.fit" if app.ui.focused == PanelKind::Layer => {
-            app.ui.layer_zoom = None;
-            app.ui.layer_pan = [0.0, 0.0];
-            return Ok(Value::Null);
-        }
-        "view.fit" => {
-            app.ui.viewer.zoom = None;
-            app.ui.viewer.fit_up_to_100 = false;
-            app.ui.viewer.pan = [0.0, 0.0];
-            return Ok(Value::Null);
-        }
-        "timeline.scrollToTime" => app.ui.timeline.scroll_to = Some(crate::state::ScrollTo::Time),
-        "timeline.scrollToLayer" => app.ui.timeline.scroll_to = Some(crate::state::ScrollTo::Layer),
-        "timeline.parentColumn" => {
-            let on = !crate::panels::timeline::column_visible(&app.ui.timeline, "parent");
-            crate::panels::timeline::set_column(&mut app.ui.timeline, "parent", on)?;
-            return Ok(json!({"parent": on}));
-        }
-        "view.fitUpTo100" => {
-            app.ui.viewer.zoom = None;
-            app.ui.viewer.fit_up_to_100 = true;
-            app.ui.viewer.pan = [0.0, 0.0];
-            return Ok(Value::Null);
-        }
-        // Shift+, / Shift+.: the previous / next open composition (the viewer's tabs).
-        "view.nextItem" | "view.previousItem" => {
-            let open = app.session.state.open_comps.clone();
-            let Some(i) = app.session.state.active_comp.and_then(|c| open.iter().position(|o| *o == c)) else { return Ok(Value::Null) };
-            let step = if id == "view.nextItem" { 1 } else { open.len().saturating_sub(1) };
-            let Some(next) = open.get((i + step) % open.len().max(1)).copied().filter(|n| Some(*n) != app.session.state.active_comp) else {
-                return Ok(Value::Null);
-            };
-            return run_engine(app, ctx, "comp.open", json!({"comp": next.0}));
-        }
-        // \\: between the Composition viewer and the Timeline.
-        "window.toggleCompTimeline" => {
-            let to = if app.ui.focused == PanelKind::Timeline { crate::panels::viewers::active_panel(app) } else { PanelKind::Timeline };
-            app.show_panel(to);
-            return Ok(json!({"focused": to.id()}));
-        }
-        // Alt+Shift+, / Alt+Shift+.: the previous / next tab of the focused panel's group.
-        "window.nextPanel" | "window.previousPanel" => {
-            let focused = app.ui.focused;
-            let group = app.ui.dock.group_of(focused);
-            let Some(i) = group.iter().position(|p| *p == focused) else { return Ok(Value::Null) };
-            let step = if id == "window.nextPanel" { 1 } else { group.len().saturating_sub(1) };
-            if let Some(next) = group.get((i + step) % group.len().max(1)).copied() {
-                app.show_panel(next);
-            }
-            return Ok(json!({"focused": app.ui.focused.id()}));
-        }
-        // Ctrl+Shift+W: with a viewer or the Timeline active, every open composition closes;
-        // any other panel closes itself.
-        "window.closeAll" => {
-            let focused = app.ui.focused;
-            if matches!(focused, PanelKind::Composition | PanelKind::Timeline | PanelKind::Viewer(_)) {
-                for c in app.session.state.open_comps.clone() {
-                    run_engine(app, ctx, "comp.close", json!({"comp": c.0}))?;
-                }
-            } else {
-                app.close_panel(focused);
-            }
-            return Ok(Value::Null);
-        }
-        "view.actualSize" if app.ui.focused == PanelKind::Layer => {
-            app.ui.layer_zoom = Some(1.0 / ctx.pixels_per_point());
-            app.ui.layer_pan = [0.0, 0.0];
-            return Ok(Value::Null);
-        }
-        "view.actualSize" => {
-            app.ui.viewer.zoom = Some(1.0 / ctx.pixels_per_point());
-            app.ui.viewer.pan = [0.0, 0.0];
-            return Ok(Value::Null);
-        }
-        "view.safeMargins" => app.ui.viewer.safe_margins = !app.ui.viewer.safe_margins,
-        "view.transparencyGrid" => app.ui.viewer.transparency_grid = !app.ui.viewer.transparency_grid,
-        "view.fastPreviews" => {
-            // With a mode: Fast Previews ▸ Off / Adaptive Resolution / Draft / Fast Draft /
-            // Wireframe; without: toggle Draft quality (Settings ▸ Previews).
-            if params.get("mode").is_some() {
-                return run_engine(app, ctx, "view.fastPreviewMode", params);
-            }
-            let on = !app.ui.viewer.fast_preview;
-            app.set_pref("previews.fastPreviews", json!(on))?;
-            app.ui.viewer.fast_preview = on;
-        }
-        "timeline.zoomIn" | "timeline.zoomOut" => {
-            let k = if id == "timeline.zoomIn" { crate::panels::timeline::ZOOM_STEP } else { 1.0 / crate::panels::timeline::ZOOM_STEP };
-            crate::panels::timeline::zoom(app, ctx, k);
-            return Ok(Value::Null);
-        }
-        "timeline.zoomFit" => crate::panels::timeline::toggle_fit_zoom(app, ctx),
-        "timeline.zoomFrameToggle" => crate::panels::timeline::toggle_frame_zoom(app, ctx),
-        "timeline.column" => {
-            let col = params.get("column").and_then(Value::as_str).ok_or("timeline.column: need `column`")?;
-            let on = params.get("visible").and_then(Value::as_bool).unwrap_or(!crate::panels::timeline::column_visible(&app.ui.timeline, col));
-            crate::panels::timeline::set_column(&mut app.ui.timeline, col, on)?;
-            let shown: Vec<&str> =
-                crate::panels::timeline::COLUMNS.iter().map(|c| c.0).filter(|c| crate::panels::timeline::column_visible(&app.ui.timeline, c)).collect();
-            return Ok(json!({"columns": shown}));
-        }
-        "timeline.sourceName" => {
-            let tl = &mut app.ui.timeline;
-            tl.source_name = params.get("value").and_then(Value::as_bool).unwrap_or(!tl.source_name);
-            return Ok(json!({"sourceName": tl.source_name}));
-        }
-        "flowchart.options" | "flowchart.graph" => return crate::panels::flowchart::command(app, id, &params),
-        "timeline.search" => {
-            app.ui.timeline.search = params.get("query").and_then(Value::as_str).unwrap_or_default().to_string();
-            app.show_panel(PanelKind::Timeline);
-        }
-        "timeline.graphEditor" => app.ui.timeline.graph_editor = !app.ui.timeline.graph_editor,
-        "timeline.switchesModes" => app.ui.timeline.show_modes = !app.ui.timeline.show_modes,
-        "timeline.collapseAll" => {
-            app.ui.timeline.open_layers.clear();
-            app.ui.timeline.open_groups.clear();
-            app.ui.timeline.reveal.clear();
-            app.ui.timeline.layer_reveal.clear();
-        }
-        // Ctrl+`: twirl the selected layers open (all closed ones) or closed (all open). From a
-        // reveal shortcut's view it opens their full property trees.
-        "timeline.twirlSelected" => {
-            let sel: Vec<u64> = app.session.state.selected_layers.iter().map(|l| l.0).collect();
-            let tl = &mut app.ui.timeline;
-            let revealing = sel.iter().any(|l| tl.layer_reveal.contains_key(l));
-            tl.reveal.clear();
-            for l in &sel {
-                tl.layer_reveal.remove(l);
-            }
-            if !revealing && sel.iter().all(|l| tl.open_layers.contains(l)) {
-                for l in &sel {
-                    tl.open_layers.remove(l);
-                }
-            } else {
-                tl.open_layers.extend(sel);
-            }
-        }
-        "timeline.workAreaBegin" => return app.session.execute("comp.workArea", json!({"set": "begin"})).map_err(|e| e.to_string()),
-        "timeline.workAreaEnd" => return app.session.execute("comp.workArea", json!({"set": "end"})).map_err(|e| e.to_string()),
-        "timeline.moveInToTime" => return timing(app, "moveInToTime"),
-        "timeline.moveOutToTime" => return timing(app, "moveOutToTime"),
-        "timeline.trimInToTime" => return timing(app, "trimInToTime"),
-        "timeline.trimOutToTime" => return timing(app, "trimOutToTime"),
-        "app.home" => app.ui.start_screen = !app.ui.start_screen,
-        "app.newComp" | "comp.new" if no_params(&params) => crate::panels::dialogs::open_new_comp(app),
-        "app.compSettings" | "comp.settings" if no_params(&params) => crate::panels::dialogs::open_comp_settings(app)?,
-        "app.compSettings" | "comp.settings" if only_comp(&params).is_some() => {
-            crate::panels::dialogs::open_comp_settings_for(app, only_comp(&params).ok_or("missing `comp`")?)?
-        }
-        "app.solidSettings" | "layer.newSolid" if no_params(&params) => crate::panels::dialogs::open_new_solid(app)?,
-        "keys.velocity" if no_params(&params) => crate::panels::key_dialogs::open_velocity(app)?,
-        "keys.interpolation" if no_params(&params) => crate::panels::key_dialogs::open_interpolation(app)?,
-        "layer.timeStretch" if no_params(&params) => crate::panels::key_dialogs::open_time_stretch(app)?,
-        _ => {
-            if id == "renderQueue.render" && params.get("wait").is_none() {
-                // The UI renders in the background; the panel shows progress.
-                let mut p = params.clone();
-                if let Some(m) = p.as_object_mut() {
-                    m.insert("wait".into(), json!(false));
-                } else {
-                    p = json!({"wait": false});
-                }
-                app.show_panel(PanelKind::RenderQueue);
-                return app.session.execute(id, p).map_err(|e| e.to_string());
-            }
-            if id == "renderQueue.add" {
-                let r = app.session.execute(id, params).map_err(|e| e.to_string());
-                match &r {
-                    Ok(_) => app.show_panel(PanelKind::RenderQueue),
-                    Err(e) => app.ui.status = e.clone(),
-                }
-                return r;
-            }
-            if let Some(r) = file_dialog(app, id, &params) {
-                return r;
-            }
-            if id == "layer.precompose" && params.get("name").is_none() {
-                crate::panels::precomp::open(app, &params)?;
-                return Ok(json!({"dialog": id}));
-            }
-            if crate::panels::dialogs::open_form(app, id, &params) {
-                return Ok(json!({"dialog": id}));
-            }
-            if id == "renderQueue.render" && params.get("wait").is_none() {
-                // The UI renders in the background; the panel shows progress.
-                let mut p = params.clone();
-                if let Some(m) = p.as_object_mut() {
-                    m.insert("wait".into(), json!(false));
-                } else {
-                    p = json!({"wait": false});
-                }
-                app.show_panel(PanelKind::RenderQueue);
-                return app.session.execute(id, p).map_err(|e| e.to_string());
-            }
-            if id == "renderQueue.add" {
-                let r = app.session.execute(id, params).map_err(|e| e.to_string());
-                match &r {
-                    Ok(_) => app.show_panel(PanelKind::RenderQueue),
-                    Err(e) => app.ui.status = e.clone(),
-                }
-                return r;
-            }
-            // An effect added to a layer (Effect menu, Last Effect, dropped on a layer) brings
-            // up Effect Controls on that layer, as in After Effects.
-            if matches!(id, "effect.apply" | "effect.applyLast") {
-                let r = run_engine(app, ctx, id, params.clone());
-                if let Ok(applied) = &r {
-                    crate::panels::effect_controls::reveal_applied(app, &params);
-                    crate::panels::effect_controls::choose_files_after_apply(app, applied);
-                }
-                return r;
-            }
-            // Enabling time remapping twirls its layers open on Time Remap and its two keys.
-            if id == "layer.enableTimeRemap" {
-                let r = run_engine(app, ctx, id, params.clone());
-                if r.as_ref().is_ok_and(|on| on.as_bool() == Some(true)) {
-                    reveal_time_remap(app, &params);
-                }
-                return r;
-            }
-            if id == "layer.rename" && params.get("name").is_none() {
-                crate::panels::timeline::begin_rename(app, ctx);
-                return Ok(Value::Null);
-            }
-            return run_engine(app, ctx, id, params);
-        }
-    }
-    Ok(Value::Null)
-}
-
-/// Run an engine command and perform the frontend events it emitted right away.
-/// Commands that fill the internal clipboard.
-const COPY_COMMANDS: &[&str] =
-    &["edit.copy", "edit.cut", "edit.copyWithPropertyLinks", "edit.copyWithRelativePropertyLinks", "edit.copyExpressionOnly", "keys.copy", "effect.copy"];
-
-/// A line for the system clipboard naming what EffectCraft copied. The system clipboard must
-/// hold something: with nothing on it, the windowing layer sends no paste event for Ctrl+V.
-fn clipboard_note(s: &effectcraft_engine::Session) -> String {
-    let st = &s.state;
-    let n = |n: usize, one: &str, many: &str| format!("EffectCraft: {n} {}", if n == 1 { one } else { many });
-    if st.clip_is_keys && !st.key_clipboard.is_empty() {
-        n(st.key_clipboard.iter().map(|c| c.keys.len()).sum(), "keyframe", "keyframes")
-    } else if !st.effect_clipboard.is_empty() {
-        n(st.effect_clipboard.len(), "effect", "effects")
-    } else if !st.contents_clipboard.is_empty() {
-        n(st.contents_clipboard.len(), "shape item", "shape items")
-    } else if st.link_clipboard.is_some() {
-        "EffectCraft: property links".into()
-    } else {
-        n(st.clipboard.len(), "layer", "layers")
-    }
-}
-
-pub(crate) fn run_engine(app: &mut EffectcraftApp, ctx: &egui::Context, id: &str, params: Value) -> Result<Value, String> {
-    // Events already queued belong to earlier invocations (`engine.execute` defers them).
-    let queued = app.session.events.len();
-    let mut r = app.session.execute(id, params).map_err(|e| e.to_string());
-    if let Err(e) = &r {
-        app.ui.status = e.clone();
-    } else if COPY_COMMANDS.contains(&id) && app.session.state.text_edit.is_none() {
-        ctx.copy_text(clipboard_note(&app.session));
-    }
-    let events = app.session.drain_events();
-    for (index, ev) in events.into_iter().enumerate() {
-        match ev {
-            effectcraft_engine::Event::Frontend { command, params } => {
-                if let Err(e) = frontend(app, ctx, &command, params) {
-                    app.ui.status = e.clone();
-                    // A frontend-only command's own failure is the command's result (#696: a
-                    // workspace save that didn't reach disk reported success). An earlier
-                    // invocation's failure only sets the status.
-                    if index >= queued && command == id && r.is_ok() {
-                        r = Err(e);
-                    }
-                }
-            }
-            other => app.session.events.push(other),
-        }
-    }
-    r
-}
-
-fn toggle(slot: &mut bool, p: &Value) -> Value {
-    *slot = p.get("value").and_then(Value::as_bool).unwrap_or(!*slot);
-    json!(*slot)
-}
-
-/// Perform a frontend command (from `Event::Frontend`).
-pub fn frontend(app: &mut EffectcraftApp, ctx: &egui::Context, id: &str, p: Value) -> Result<Value, String> {
-    let now = app.now();
-    let v = &mut app.ui.viewer;
-    Ok(match id {
-        "mediaBrowser.copySourcePath" => {
-            let path = p.get("path").and_then(Value::as_str).filter(|path| !path.is_empty()).ok_or("A source path is required")?;
-            ctx.copy_text(path.to_string());
-            json!({"path": path})
-        }
-        "effects.copyPresetsFolderPath" => {
-            if cfg!(target_arch = "wasm32") {
-                return Err("The web app has no local presets folder".into());
-            }
-            let path = crate::panels::effects_presets::presets_dir().filter(|path| !path.as_os_str().is_empty()).ok_or("No presets folder is configured")?;
-            let path = std::path::absolute(path).map_err(|e| format!("Cannot resolve the presets folder path: {e}"))?;
-            let path = path.to_str().ok_or("The presets folder path is not valid UTF-8")?;
-            ctx.copy_text(path.to_string());
-            json!({"path": path})
-        }
-        "app.checkForUpdates" | "help.checkForUpdates" => {
-            crate::updates_ui::check(app);
-            Value::Null
-        }
-        "app.about" => {
-            app.dialog = Some(crate::Dialog::About);
-            Value::Null
-        }
-        // Window ▸ <ScriptUI panel>: dock (or bring forward) the panel the script built.
-        // Audio scrubbing: one frame of audio at `time` (default the current time).
-        "playback.scrubAudio" => {
-            let cid = app.session.active_comp_id().ok_or("no composition")?;
-            let t = p.get("time").and_then(Value::as_f64).map_or(app.session.time(), effectcraft_engine::time::Tick::from_seconds_f64);
-            app.scrub_audio(cid, t, now);
-            json!({"playing": app.scrub.is_some()})
-        }
-        // View ▸ New Viewer.
-        "view.newViewer" => json!({"viewer": crate::panels::viewers::new_viewer(app)}),
-        // Reveal Layer Source / Reveal Composition: show the Project panel on the item, opening
-        // its folders and clearing the search so the row is visible.
-        "project.reveal" => {
-            let ids: Vec<effectcraft_engine::project::ItemId> = p
-                .get("items")
-                .and_then(Value::as_array)
-                .map(|items| items.iter().filter_map(Value::as_u64).map(effectcraft_engine::project::ItemId).collect())
-                .or_else(|| p.get("item").and_then(Value::as_u64).map(|item| vec![effectcraft_engine::project::ItemId(item)]))
-                .unwrap_or_default();
-            crate::panels::project::reveal(app, ctx, &ids);
-            json!({"items": ids.iter().map(|item| item.0).collect::<Vec<_>>()})
-        }
-        // Run by id (control channel, MCP): the Project panel's selection, whatever has focus.
-        "project.deleteWithoutConfirmation" => crate::panels::delete_items::delete_confirmed(app, ctx, json!({}))?,
-        // A gradient property's "Edit Gradient…" (the Timeline's value): the Gradient Editor.
-        "prop.editGradient" => crate::panels::gradient_editor::open(app, &p)?,
-        "window.scriptPanel" => {
-            let id = p.get("window").and_then(Value::as_u64).ok_or("no ScriptUI panel window")? as u32;
-            app.show_panel(PanelKind::ScriptPanel(id));
-            json!({"window": id})
-        }
-        "layer.style.options" => {
-            crate::panels::layer_styles_dialog::open(app, &p)?;
-            Value::Null
-        }
-        "app.settings" => {
-            let page = p.get("page").and_then(Value::as_str).unwrap_or("general");
-            crate::panels::settings::open(app, effectcraft_engine::prefs::page_id(page).unwrap_or("general"));
-            Value::Null
-        }
-        "app.gpuInfo" => {
-            crate::panels::dialogs::info(
-                app,
-                "GPU Information",
-                &format!(
-                    "{}Layer cache: {} MB  •  Preview cache: {} MB.",
-                    effectcraft_engine::sysinfo::gpu_summary(&app.session),
-                    app.session.layer_cache.budget() >> 20,
-                    app.frames.budget() >> 20
-                ),
-            );
-            Value::Null
-        }
-        "app.hide" | "app.hideOthers" | "app.showAll" => {
-            // The desktop app asks macOS (NSApplication hide / hideOtherApplications /
-            // unhideAllApplications); elsewhere Hide minimizes and the others don't apply.
-            if app.hooks.app_action.as_ref().is_some_and(|f| f(id)) {
-                return Ok(Value::Null);
-            }
-            match id {
-                "app.hide" => ctx.send_viewport_cmd(egui::ViewportCommand::Minimized(true)),
-                _ => return Err(format!("`{id}` is only available on macOS")),
-            }
-            Value::Null
-        }
-        "app.quit" => {
-            ctx.send_viewport_cmd(egui::ViewportCommand::Close);
-            Value::Null
-        }
-        "app.commandPalette" => {
-            app.dialog_state.palette_query = p.get("query").and_then(Value::as_str).unwrap_or_default().to_string();
-            app.dialog_state.palette_sel = 0;
-            app.dialog = Some(crate::Dialog::CommandPalette);
-            Value::Null
-        }
-        "app.keyboardShortcuts" => {
-            crate::panels::shortcut_editor::open(app);
-            Value::Null
-        }
-        "app.templates" => {
-            let kind = p.get("kind").and_then(Value::as_str).unwrap_or("renderSettings");
-            crate::panels::rq_templates::open(app, ctx, kind);
-            Value::Null
-        }
-        "renderQueue.notify" => {
-            // Render finished with Notify on: a toast, the dock/taskbar attention request, and the
-            // host's system sound (the desktop app handles `renderQueue.notify`).
-            let msg = p.get("message").and_then(Value::as_str).unwrap_or("Render finished").to_string();
-            app.toast = Some((msg, now));
-            ctx.send_viewport_cmd(egui::ViewportCommand::RequestUserAttention(egui::UserAttentionType::Informational));
-            if let Some(f) = app.hooks.app_action.as_ref() {
-                f("renderQueue.notify");
-            }
-            Value::Null
-        }
-        "app.find" => {
-            if let Some(q) = p.get("query").and_then(Value::as_str) {
-                app.ui.project_search = q.to_string();
-            }
-            app.show_panel(PanelKind::Project);
-            Value::Null
-        }
-        "playback.toggle" => {
-            // The play button and Spacebar: `{shortcut?}` picks which Preview panel shortcut's
-            // options to play with (default Spacebar).
-            let sc = match p.get("shortcut").and_then(Value::as_str) {
-                Some(k) => effectcraft_engine::preview::PreviewShortcut::parse(k).ok_or_else(|| format!("unknown preview shortcut `{k}`"))?,
-                None => effectcraft_engine::preview::PreviewShortcut::Spacebar,
-            };
-            app.toggle_play_with(now, sc);
-            json!({"playing": app.playback.playing, "shortcut": sc.id()})
-        }
-        "playback.cacheWhenIdle" => {
-            let r = toggle(&mut app.ui.cache_when_idle, &p);
-            app.set_pref("previews.cacheFramesWhenIdle", r.clone())?;
-            r
-        }
-        "playback.audio" => {
-            // Include Audio of the shortcut shown in the Preview panel.
-            let mut on = app.session.prefs.preview.active().include_audio;
-            let r = toggle(&mut on, &p);
-            app.session.execute("playback.settings.set", json!({"includeAudio": on})).map_err(|e| e.to_string())?;
-            if !on {
-                app.audio = None;
-            }
-            r
-        }
-        // Zoom In / Zoom Out act on the focused viewer: the Layer panel when it has focus, else
-        // the Composition viewer.
-        "view.zoomIn" | "view.zoomOut" if app.ui.focused == PanelKind::Layer => {
-            let cur = app.ui.layer_zoom.unwrap_or_else(|| crate::panels::layer_panel::last_fit(ctx));
-            // The Layer panel zooms in points (pixels-per-point 1).
-            let next = zoom_step(cur, 1.0, id == "view.zoomIn");
-            app.ui.layer_zoom = Some(next);
-            json!({"zoom": next, "panel": "layer"})
-        }
-        "view.zoomIn" | "view.zoomOut" => {
-            let ppp = ctx.pixels_per_point();
-            let cur = v.zoom.unwrap_or_else(|| crate::panels::viewer::last_fit(ctx));
-            let next = zoom_step(cur, ppp, id == "view.zoomIn");
-            v.zoom = Some(next);
-            json!({"zoom": next})
-        }
-        // View ▸ Resolution ▸ Custom without a factor (the engine sets the comp's resolution).
-        "view.res.custom" => {
-            let cur = match app.viewer_res() {
-                Resolution::Custom(n) => f64::from(n),
-                _ => 2.0,
-            };
-            crate::panels::dialogs::form(
-                app,
-                "Custom Resolution",
-                "view.res.custom",
-                json!({}),
-                vec![crate::panels::dialogs::Field::num("factor", "Render every n-th pixel", cur)],
-            );
-            Value::Null
-        }
-        "view.rulers" => toggle(&mut v.rulers, &p),
-        "view.guides" => toggle(&mut v.guides, &p),
-        "view.snapToGuides" => toggle(&mut v.snap_guides, &p),
-        "view.lockGuides" => toggle(&mut v.lock_guides, &p),
-        "view.grid" => toggle(&mut v.grid, &p),
-        "view.snapToGrid" => toggle(&mut v.snap_grid, &p),
-        "view.layerControls" => toggle(&mut v.show_layer_controls, &p),
-        "view.options" => {
-            app.dialog = Some(crate::Dialog::ViewOptions);
-            Value::Null
-        }
-        "view.panelBackground" => {
-            if p.get("pick").and_then(Value::as_bool) == Some(true) {
-                let [r, g, b] = v.custom_pasteboard;
-                crate::panels::dialogs::form(
-                    app,
-                    "Panel Background Color",
-                    "view.panelBackground",
-                    json!({}),
-                    vec![crate::panels::dialogs::Field::text("color", "Color (#rrggbb)", &format!("#{r:02x}{g:02x}{b:02x}"))],
-                );
-                return Ok(Value::Null);
-            }
-            let c = p.get("color").and_then(Value::as_str).unwrap_or("mediumGray");
-            v.pasteboard = match c {
-                "black" => Some([0, 0, 0]),
-                "darkGray" => Some([0x2a, 0x2a, 0x2a]),
-                "mediumGray" => None,
-                "lightGray" => Some([0xb4, 0xb4, 0xb4]),
-                "white" => Some([0xff, 0xff, 0xff]),
-                "custom" => Some(v.custom_pasteboard),
-                hex => {
-                    let c = effectcraft_engine::color::Rgba::from_hex(hex).ok_or_else(|| format!("unknown colour `{hex}`"))?;
-                    let rgb = [(c.r * 255.0).round() as u8, (c.g * 255.0).round() as u8, (c.b * 255.0).round() as u8];
-                    v.custom_pasteboard = rgb;
-                    Some(rgb)
-                }
-            };
-            Value::Null
-        }
-        // Ctrl+\ / Cmd+\, as in After Effects (#336): `{maximized}`, the window's new state.
-        "window.maximizeApp" => {
-            let maximized = !ctx.input(|i| i.viewport().maximized.unwrap_or(false));
-            ctx.send_viewport_cmd(egui::ViewportCommand::Maximized(maximized));
-            json!({"maximized": maximized})
-        }
-        "view.fullScreen" => {
-            let full = ctx.input(|i| i.viewport().fullscreen.unwrap_or(false));
-            ctx.send_viewport_cmd(egui::ViewportCommand::Fullscreen(!full));
-            json!(!full)
-        }
-        "window.panel" => {
-            let name = p.get("panel").and_then(Value::as_str).unwrap_or_default();
-            if name.eq_ignore_ascii_case("tools") {
-                app.ui.status = "The Tools panel is the toolbar in the header".into();
-                return Ok(Value::Null);
-            }
-            let panel = PanelKind::from_name(name).ok_or_else(|| format!("unknown panel `{name}`"))?;
-            app.show_panel(panel);
-            Value::Null
-        }
-        "window.workspace" => {
-            let want = p.get("name").and_then(Value::as_str).unwrap_or("Default").to_ascii_lowercase().replace(' ', "");
-            let name = app
-                .workspace_names()
-                .into_iter()
-                .find(|w| w.to_ascii_lowercase().replace(' ', "") == want)
-                .ok_or_else(|| format!("unknown workspace `{want}`"))?;
-            app.set_workspace(&name);
-            json!({"workspace": name})
-        }
-        "window.resetWorkspace" => {
-            let name = app.ui.workspace.clone();
-            app.set_workspace(&name);
-            Value::Null
-        }
-        "window.saveWorkspace" => {
-            let name = app.ui.workspace.clone();
-            app.ui.saved_workspaces.insert(name.clone(), app.ui.dock.clone());
-            app.store_saved_workspaces()?;
-            json!({"workspace": name})
-        }
-        "window.saveWorkspaceAs" => {
-            let Some(name) = p.get("name").and_then(Value::as_str).map(str::trim).filter(|n| !n.is_empty()).map(str::to_string) else {
-                crate::panels::dialogs::form(
-                    app,
-                    "New Workspace",
-                    "window.saveWorkspaceAs",
-                    json!({}),
-                    vec![crate::panels::dialogs::Field::text("name", "Name", "Untitled Workspace")],
-                );
-                return Ok(Value::Null);
-            };
-            app.ui.saved_workspaces.insert(name.clone(), app.ui.dock.clone());
-            app.ui.workspace = name.clone();
-            app.store_saved_workspaces()?;
-            json!({"workspace": name})
-        }
-        "window.editWorkspaces" => {
-            let Some(name) = p.get("name").and_then(Value::as_str).map(str::to_string) else {
-                let cur = app.ui.workspace.clone();
-                crate::panels::dialogs::form(
-                    app,
-                    "Edit Workspaces",
-                    "window.editWorkspaces",
-                    json!({}),
-                    vec![
-                        crate::panels::dialogs::Field::text("name", "Workspace", &cur),
-                        crate::panels::dialogs::Field::text("rename", "Rename to", &cur),
-                        crate::panels::dialogs::Field::bool("delete", "Delete", false),
-                    ],
-                );
-                return Ok(Value::Null);
-            };
-            let builtin = crate::dock::WORKSPACES.contains(&name.as_str());
-            if p.get("delete").and_then(Value::as_bool) == Some(true) {
-                if app.ui.saved_workspaces.remove(&name).is_none() && !builtin {
-                    return Err(format!("no workspace `{name}`"));
-                }
-                // Leave the deleted workspace first: a current workspace needs a definition.
-                if app.ui.workspace == name {
-                    app.set_workspace("Default");
-                }
-                app.store_saved_workspaces()?;
-                return Ok(json!({"deleted": name}));
-            }
-            if let Some(new) = p.get("rename").and_then(Value::as_str).map(str::trim).filter(|n| !n.is_empty() && *n != name) {
-                if builtin {
-                    return Err(format!("`{name}` is a built-in workspace: save it as a new workspace instead"));
-                }
-                let dock = app.ui.saved_workspaces.remove(&name).ok_or_else(|| format!("no workspace `{name}`"))?;
-                app.ui.saved_workspaces.insert(new.to_string(), dock);
-                if app.ui.workspace == name {
-                    app.ui.workspace = new.to_string();
-                }
-                app.store_saved_workspaces()?;
-                return Ok(json!({"renamed": new}));
-            }
-            json!({"workspaces": app.workspace_names()})
-        }
-        "view.lookAt" => {
-            let r: Vec<f64> = p.get("rect").and_then(Value::as_array).map(|a| a.iter().filter_map(Value::as_f64).collect()).unwrap_or_default();
-            if r.len() == 4 {
-                let map: Option<crate::panels::viewer::ViewerMap> = ctx.data(|d| d.get_temp(egui::Id::unique("viewer-map")));
-                if let Some(m) = map {
-                    let (rw, rh) = (((r[2] - r[0]) as f32).max(1.0), ((r[3] - r[1]) as f32).max(1.0));
-                    let zoom = ((m.area.width() - 40.0) / rw).min((m.area.height() - 40.0) / rh).clamp(0.015, 32.0);
-                    let rc = [(r[0] + r[2]) as f32 / 2.0, (r[1] + r[3]) as f32 / 2.0];
-                    let v = &mut app.ui.viewer;
-                    v.zoom = Some(zoom);
-                    v.pan = [m.comp[0] * zoom / 2.0 - rc[0] * zoom, m.comp[1] * zoom / 2.0 - rc[1] * zoom];
-                }
-            }
-            Value::Null
-        }
-        "comp.flowchart" => {
-            // Chart the active comp; Layer ▸ Reveal ▸ Reveal Layer in Project Flowchart shows
-            // layers and selects the layer's node.
-            app.ui.flowchart.root = app.session.active_comp_id().map(|c| c.0);
-            if let (Some(c), Some(l)) = (app.session.active_comp_id(), app.session.state.selected_layers.first()) {
-                app.ui.flowchart.layers = true;
-                app.ui.flowchart.selected = Some(format!("layer:{}:{}", c.0, l.0));
-            }
-            app.show_panel(PanelKind::Flowchart);
-            Value::Null
-        }
-        "comp.miniFlowchart" => {
-            let at = ctx.input(|i| i.pointer.hover_pos()).unwrap_or_else(|| ctx.content_rect().center());
-            app.ui.mini_flowchart = Some([at.x, at.y]);
-            Value::Null
-        }
-        "track.editTargetDialog" => {
-            crate::panels::tracker::open_target(app)?;
-            Value::Null
-        }
-        "track.optionsDialog" => {
-            crate::panels::tracker::open_options(app)?;
-            Value::Null
-        }
-        "layer.openLayer" => {
-            let id = p.get("layer").and_then(Value::as_u64).or_else(|| app.session.state.selected_layers.first().map(|l| l.0));
-            // Another layer opens at Fit.
-            if id != app.ui.layer_panel {
-                app.ui.layer_zoom = None;
-                app.ui.layer_pan = [0.0, 0.0];
-            }
-            app.ui.layer_panel = id;
-            app.ui.layer_view = None;
-            app.show_panel(PanelKind::Layer);
-            Value::Null
-        }
-        "app.confirmExecute" => {
-            // Settings ▸ Scripting ▸ Warn User When Executing Files.
-            let path = p.get("path").and_then(Value::as_str).unwrap_or_default().to_string();
-            crate::panels::forms::form(
-                app,
-                "A script wants to open a file",
-                "file.executeFile",
-                json!({"path": path, "confirmed": true}),
-                vec![crate::panels::forms::Field::text("path", "Open", &path)],
-            );
-            Value::Null
-        }
-        "app.showReport" => {
-            let title = p.get("title").and_then(Value::as_str).unwrap_or("Report").to_string();
-            let text = p.get("text").and_then(Value::as_str).unwrap_or_default().to_string();
-            crate::panels::dialogs::info(app, &title, &text);
-            Value::Null
-        }
-        "window.assignWorkspaceShortcut" => {
-            let mut q = p.clone();
-            q["workspace"] = json!(app.ui.workspace);
-            return run_engine(app, ctx, "window.assignWorkspaceShortcut", q);
-        }
-        "file.interpretFootage" => {
-            // Import ▸ Interpret Unlabeled Alpha As: Ask User.
-            if let Some(i) = p.get("item").and_then(Value::as_u64) {
-                app.session.state.project_selection = vec![effectcraft_engine::project::ItemId(i)];
-            }
-            crate::panels::dialogs::open_form(app, "file.interpretFootage", &json!({}));
-            Value::Null
-        }
-        // Help ▸ In-App Tutorials: the Home screen's Learn tab.
-        "help.inAppTutorials" => {
-            app.ui.start_screen = true;
-            app.ui.home_learn = true;
-            app.ui.home_templates = false;
-            Value::Null
-        }
-        // File ▸ New ▸ New Project from Template…: the Home screen's Templates tab.
-        "file.newFromTemplate" => {
-            app.ui.start_screen = true;
-            app.ui.home_learn = false;
-            app.ui.home_templates = true;
-            Value::Null
-        }
-        "effect.manage" | "anim.browsePresets" => {
-            app.show_panel(PanelKind::EffectsPresets);
-            Value::Null
-        }
-        "timeline.revealProps" => {
-            let props = p.get("props").and_then(Value::as_array).cloned().unwrap_or_default();
-            let uids = |k: &str| -> Vec<u64> { props.iter().filter_map(|x| x.get(k).and_then(Value::as_u64)).collect() };
-            let (found, with_props) = (uids("prop"), uids("layer"));
-            // The layers it looked at (`layers`), else those it found something on. Layers that
-            // have nothing to show close; the others' reveals stay.
-            let targets: Vec<u64> = match p.get("layers").and_then(Value::as_array) {
-                Some(l) => l.iter().filter_map(Value::as_u64).collect(),
-                None => with_props.clone(),
-            };
-            // The targets' earlier picks go (U after UU shows the keyframed ones only).
-            let comp = app.session.active_comp_arc();
-            let theirs = |u: u64| {
-                comp.as_ref().is_some_and(|c| {
-                    targets
-                        .iter()
-                        .filter_map(|l| c.layer(effectcraft_engine::project::LayerId(*l)))
-                        .any(|l| l.props.find(u).is_some() || l.props.find_group(u).is_some())
-                })
-            };
-            let tl = &mut app.ui.timeline;
-            tl.reveal_props.retain(|u| !theirs(*u));
-            tl.reveal_props.extend(found.iter().copied());
-            let (shown, hidden): (Vec<u64>, Vec<u64>) = targets.into_iter().partition(|l| with_props.contains(l));
-            tl.apply_reveal(&hidden, vec![]);
-            if !shown.is_empty() {
-                tl.apply_reveal(&shown, vec!["props".into()]);
-            }
-            // Properties inside effects (puppet pins…) show under their effect, twirled open.
-            for (layer, prop) in props.iter().filter_map(|x| Some((x.get("layer")?.as_u64()?, x.get("prop")?.as_u64()?))) {
-                crate::panels::timeline::open_effect_paths(app, layer, &[prop]);
-            }
-            json!({"revealed": found.len()})
-        }
-        _ => return Err(format!("`{id}` is not a frontend command")),
-    })
-}
-
-/// Commands that need a file or folder path: ask the host's file dialog when `params` lacks one.
-fn file_dialog(app: &mut EffectcraftApp, id: &str, params: &Value) -> Option<Result<Value, String>> {
-    enum Ask {
-        Folder,
-        Import,
-        OpenProject,
-        Save(&'static str),
-        Open(&'static [&'static str]),
-    }
-    let (key, ask) = match id {
-        "file.import" | "file.importMultiple" => ("paths", Ask::Import),
-        "file.open" => ("path", Ask::OpenProject),
-        "file.save" if app.session.path.is_none() => ("path", Ask::Save("Untitled Project.ecproj")),
-        "file.saveAs" | "file.saveCopy" => ("path", Ask::Save("Untitled Project.ecproj")),
-        "comp.saveFrameAs" => ("path", Ask::Save("Frame.png")),
-        "comp.saveFrameAsPsd" => ("path", Ask::Save("Frame.psd")),
-        "comp.saveFrameAsExr" => ("path", Ask::Save("Frame.exr")),
-        "file.watchFolder" if params.get("stop").is_none() => ("folder", Ask::Save("Watch Folder")),
-        "anim.savePreset" => ("path", Ask::Save("Preset.ecpreset")),
-        "anim.applyPreset" => ("path", Ask::Open(&["ecpreset", "json"])),
-        "view.exportGuides" => ("path", Ask::Save("Guides.json")),
-        "view.importGuides" => ("path", Ask::Open(&["json"])),
-        "file.exportLottie" => ("path", Ask::Save("Animation.json")),
-        "file.importLottie" => ("path", Ask::Open(&["json", "lottie"])),
-        "file.importProject" => ("path", Ask::Open(&["ecproj", "ecprojx"])),
-        "file.importTimeline" => ("path", Ask::Open(&["xml", "fcpxml", "otio", "edl", "aaf", "omf"])),
-        "render.saveCurrentPreview" => ("path", Ask::Save("Preview.mp4")),
-        "file.runScript" if params.get("name").is_none() => ("path", Ask::Open(&["jsx", "js", "jsonl", "json", "txt"])),
-        "file.installScript" | "file.installScriptUIPanel" => ("path", Ask::Open(&["jsx", "js"])),
-        "effect.plugins.load" if params.get("folder").is_none() => ("path", Ask::Open(&["wasm", "wat"])),
-        "file.replaceFootage" => ("path", Ask::Import),
-        "file.relinkFootage" => ("folder", Ask::Folder),
-        "file.collectFiles" => ("folder", Ask::Save("Collected Files")),
-        "file.saveCopyAsXml" => ("path", Ask::Save("Untitled Project.ecprojx")),
-        "keys.rpfCameraImport" => ("path", Ask::Open(&["json", "csv", "txt"])),
-        "essential.exportTemplate" => ("path", Ask::Save("Template.ectemplate")),
-        "essential.importTemplate" => ("path", Ask::Open(&["ectemplate"])),
-        "file.setProxy" => {
-            ("path", Ask::Open(&["mp4", "mov", "m4v", "mkv", "webm", "mxf", "png", "jpg", "jpeg", "gif", "webp", "tif", "tiff", "bmp", "tga", "exr"]))
-        }
-        _ => return None,
-    };
-    if params.get(key).is_some()
-        || params.get("path").is_some()
-        || params.get("paths").is_some()
-        || params.get("steps").is_some()
-        || params.get("preset").is_some()
-    {
-        return None;
-    }
-    const MEDIA: &[&str] = &[
-        "mp4", "mov", "m4v", "mkv", "webm", "mxf", "png", "jpg", "jpeg", "gif", "webp", "tif", "tiff", "bmp", "exr", "dpx", "cin", "wav", "aif", "aiff", "mp3",
-        "flac", "ogg", "opus", "svg", "pdf", "ai", "eps", "psd", "psb", "tga", "hdr", "gltf", "glb", "obj", "stl", "fbx", "json", "csv", "tsv",
-    ];
-    // A host whose blocking dialogs are unsafe inside this frame shows the dialog without
-    // blocking — macOS: the nested event loop re-entered winit's handler on a drag over the
-    // window and aborted the app (#511); Linux: the desktop portal's answer never gets pumped,
-    // so the compositor marks the window as not responding (#1275) — and the command continues
-    // when the answer arrives.
-    if let Some(spawn) = app.hooks.file_dialog_async.as_ref() {
-        let request = match ask {
-            Ask::Folder => crate::FileDialog::Folder,
-            Ask::Import => crate::FileDialog::Open { exts: MEDIA.iter().map(|e| e.to_string()).collect(), many: key == "paths" },
-            Ask::OpenProject => crate::FileDialog::OpenProject,
-            Ask::Open(exts) => crate::FileDialog::Open { exts: exts.iter().map(|e| e.to_string()).collect(), many: false },
-            Ask::Save(default) => crate::FileDialog::save(default),
-        };
-        let tx = app.dialog_answers.0.clone();
-        let answer = crate::DialogAnswer { command: id.to_string(), key, params: params.clone(), paths: Vec::new() };
-        app.file_dialogs.opened();
-        spawn(
-            request,
-            Box::new(move |paths| {
-                let _ = tx.send(crate::DialogAnswer { paths, ..answer });
-            }),
-        );
-        return Some(Ok(json!({"dialog": id})));
-    }
-    let picked: Option<Value> = match ask {
-        Ask::Folder => {
-            let Some(f) = app.hooks.pick_folder.as_ref() else { return Some(Err("no folder dialog available (pass `folder`)".into())) };
-            f().map(Value::from)
-        }
-        Ask::Import => {
-            let Some(f) = app.hooks.pick_files.as_ref() else { return Some(Err("no file dialog available (pass `paths`)".into())) };
-            picked_value(key, f(MEDIA))
-        }
-        Ask::OpenProject => {
-            let Some(f) = app.hooks.pick_open_project.as_ref() else { return Some(Err("no file dialog available (pass `path`)".into())) };
-            f().map(|s| json!(s))
-        }
-        Ask::Open(exts) => {
-            let Some(f) = app.hooks.pick_files.as_ref() else { return Some(Err("no file dialog available (pass `path`)".into())) };
-            f(exts).first().map(|s| json!(s))
-        }
-        Ask::Save(default) => {
-            let Some(picked) = app.hooks.save_dialog(default) else { return Some(Err("no file dialog available (pass `path`)".into())) };
-            picked.map(|s| json!(s))
-        }
-    };
-    let Some(v) = picked else { return Some(Ok(Value::Null)) };
-    Some(run_with_picked(app, id, key, params, v))
-}
-
-/// The dialog's answer as the command's `key` parameter (`None`: cancelled).
-fn picked_value(key: &str, paths: Vec<String>) -> Option<Value> {
-    match (paths.is_empty(), key) {
-        (true, _) => None,
-        (false, "paths") => Some(json!(paths)),
-        (false, _) => paths.into_iter().next().map(Value::from),
-    }
-}
-
-/// A file dialog shown without blocking ([`crate::Hooks::file_dialog_async`]) answered: run its
-/// command with the picked path (nothing when it was cancelled).
-pub(crate) fn dialog_answered(app: &mut EffectcraftApp, answer: crate::DialogAnswer) {
-    let Some(v) = picked_value(answer.key, answer.paths) else { return };
-    if let Err(e) = run_with_picked(app, &answer.command, answer.key, &answer.params, v) {
-        app.ui.status = e;
-    }
-}
-
-/// Run command `id` with the path picked for it in parameter `key`.
-fn run_with_picked(app: &mut EffectcraftApp, id: &str, key: &str, params: &Value, v: Value) -> Result<Value, String> {
-    let mut p = params.as_object().cloned().unwrap_or_default();
-    p.insert(key.to_string(), v);
-    // Picked files import in the background, with the Importing card showing progress (#270).
-    if matches!(id, "file.import" | "file.importMultiple") {
-        p.insert("background".into(), Value::Bool(true));
-    }
-    // Photoshop files ask how to import them first; numbered stills whether to import them as an
-    // image sequence.
-    let picked = Value::Object(p.clone());
-    if id == "file.import" && crate::panels::dialogs::open_form(app, id, &picked)
-        || matches!(id, "file.import" | "file.importMultiple") && crate::panels::forms::open_import_sequence(app, &picked)
-    {
-        return Ok(json!({"dialog": id}));
-    }
-    // Save (untitled) becomes Save As.
-    let id = if id == "file.save" { "file.saveAs" } else { id };
-    let r = app.session.execute(id, Value::Object(p)).map_err(|e| e.to_string());
-    if let Err(e) = &r {
-        app.ui.status = e.clone();
-    }
-    r
-}
-
-/// A menu entry for display / `ui.menu.list`.
-#[derive(Clone, Debug, serde::Serialize)]
-pub struct MenuItem {
-    pub id: String,
-    pub label: String,
-    pub path: Vec<String>,
-    pub shortcut: Option<String>,
-    pub enabled: bool,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub checked: Option<bool>,
-    /// Parameters bound to the entry (e.g. the effect for Effect menu items).
-    #[serde(skip_serializing_if = "Value::is_null")]
-    pub params: Value,
-}
-
-/// Top-level menus in order.
-pub fn menus() -> Vec<&'static str> {
-    effectcraft_engine::menus::top_level()
-}
-
-pub(crate) fn entry_label(app: &EffectcraftApp, e: &MenuEntry) -> String {
-    let shown = match e.command.as_str() {
-        "edit.undo" => app.session.history.undo.last().map(|u| format!("Undo {}", u.0)).unwrap_or_else(|| "Can't Undo".into()),
-        "edit.redo" => app.session.history.redo.last().map(|u| format!("Redo {}", u.0)).unwrap_or_else(|| "Can't Redo".into()),
-        // Window ▸ Layer: the layer open in the Layer panel.
-        "window.panel" if e.params.get("panel").and_then(Value::as_str) == Some("layer") => {
-            let name = app
-                .ui
-                .layer_panel
-                .and_then(|id| app.session.active_comp().and_then(|c| c.layer(effectcraft_engine::project::LayerId(id))))
-                .map(|l| l.name.clone());
-            format!("Layer: {}", name.unwrap_or_else(|| "(none)".into()))
-        }
-        _ => effectcraft_engine::menus::entry_label(&app.session, e),
-    };
-    crate::i18n::entry(app, e, shown)
-}
-
-/// The entry's shortcut in the active keyboard shortcut preset.
-pub(crate) fn entry_shortcut(app: &EffectcraftApp, e: &MenuEntry) -> Option<String> {
-    app.session.shortcuts().shortcut_of(&e.command, &e.params).map(str::to_string)
-}
-
-/// Whether panel `p` is on screen: the front tab of a floating window, or of a docked group
-/// (an open frame in a stack) that a maximized panel does not cover.
-pub(crate) fn panel_shown(app: &EffectcraftApp, p: PanelKind) -> bool {
-    if app.ui.dock.is_floating(p) {
-        return app.ui.dock.is_visible(p);
-    }
-    match app.ui.maximized.filter(|m| app.ui.dock.is_docked(*m)) {
-        Some(m) => m == p,
-        None => app.ui.dock.is_visible(p),
-    }
-}
-
-/// The command a menu entry runs when chosen from a menu: Window ▸ `<panel>` closes a panel whose
-/// entry is checked, as in After Effects (#1630). Shortcuts and agents calling `window.panel`
-/// still only show the panel.
-pub(crate) fn menu_choice(app: &EffectcraftApp, id: String, params: Value) -> (String, Value) {
-    if id == "window.panel"
-        && let Some(p) = params.get("panel").and_then(Value::as_str).and_then(PanelKind::from_name)
-        && panel_shown(app, p)
-    {
-        return ("window.closePanel".into(), params);
-    }
-    (id, params)
-}
-
-/// Check-mark state of frontend toggles (engine state is answered by the engine).
-pub(crate) fn entry_checked(app: &EffectcraftApp, e: &MenuEntry) -> Option<bool> {
-    let v = &app.ui.viewer;
-    let pstr = |k: &str| e.params.get(k).and_then(Value::as_str);
-    match e.command.as_str() {
-        "view.rulers" => Some(v.rulers),
-        "view.guides" => Some(v.guides),
-        "view.snapToGuides" => Some(v.snap_guides),
-        "view.lockGuides" => Some(v.lock_guides),
-        "view.grid" => Some(v.grid),
-        "view.snapToGrid" => Some(v.snap_grid),
-        "view.layerControls" => Some(v.show_layer_controls),
-        "playback.cacheWhenIdle" => Some(app.ui.cache_when_idle),
-        "playback.audio" => Some(app.session.prefs.preview.active().include_audio),
-        "window.workspace" => Some(pstr("name").is_some_and(|n| n == app.ui.workspace)),
-        // The Tools panel is the header toolbar: always on screen.
-        "window.panel" => Some(pstr("panel").is_some_and(|n| n.eq_ignore_ascii_case("tools") || PanelKind::from_name(n).is_some_and(|p| panel_shown(app, p)))),
-        "view.panelBackground" if e.params.get("pick").is_none() => {
-            let cur = match v.pasteboard {
-                None => "mediumGray",
-                Some([0, 0, 0]) => "black",
-                Some([0x2a, 0x2a, 0x2a]) => "darkGray",
-                Some([0xb4, 0xb4, 0xb4]) => "lightGray",
-                Some([0xff, 0xff, 0xff]) => "white",
-                Some(_) => "custom",
-            };
-            Some(pstr("color") == Some(cur))
-        }
-        _ => effectcraft_engine::menus::checked(&app.session, &e.command, &e.params),
-    }
-}
-
-pub(crate) fn entry_enabled(app: &EffectcraftApp, e: &MenuEntry) -> bool {
-    // The Project-panel enabled rules mirror the invoke redirects, so they stand down for the
-    // same reason (see the redirect block): while a text edit is open the menu items must be
-    // enabled by what their routed command can do, or the menu grays out commands that work.
-    if app.ui.focused == PanelKind::Project && app.session.state.text_edit.is_none() {
-        match e.command.as_str() {
-            "edit.duplicate" => {
-                return !app.session.state.project_selection.is_empty()
-                    && app.session.state.project_selection.iter().all(|id| app.session.project.item(*id).is_some_and(|i| !i.is_folder()));
-            }
-            "edit.selectAll" => return !app.session.project.items.is_empty(),
-            "edit.deselectAll" => return !app.session.state.project_selection.is_empty(),
-            "edit.cut" | "edit.copy" | "edit.paste" | "edit.copyWithPropertyLinks" | "edit.copyWithRelativePropertyLinks" | "edit.copyExpressionOnly" => {
-                return false;
-            }
-            _ => {}
-        }
-    }
-    if e.command == "edit.clear" && app.ui.focused == PanelKind::Project {
-        return app.session.is_enabled("project.delete");
-    }
-    if e.command == "edit.clear" && app.ui.focused == PanelKind::RenderQueue {
-        return !app.session.is_rendering() && !app.session.project.render_queue.is_empty();
-    }
-    if e.command == "window.panel" {
-        return true;
-    }
-    app.session.is_enabled(&e.command)
-}
-
-/// Every menu entry, flattened with its submenu path.
-pub fn menu_items(app: &EffectcraftApp) -> Vec<MenuItem> {
-    effectcraft_engine::menus::entries()
-        .into_iter()
-        .map(|(path, e)| MenuItem {
-            id: e.command.clone(),
-            label: entry_label(app, e),
-            path,
-            shortcut: entry_shortcut(app, e),
-            enabled: entry_enabled(app, e),
-            checked: entry_checked(app, e),
-            params: e.params.clone(),
-        })
-        .collect()
-}
-
-/// Shortcut text in this OS's notation (`⇧⌘K` on macOS, `Ctrl+Shift+K` elsewhere).
-pub fn shortcut_text(s: &str) -> String {
-    if cfg!(target_os = "macos") {
-        let mut out = String::new();
-        let parts: Vec<&str> = match s.strip_suffix("++") {
-            Some(head) => vec![head, "+"],
-            None => s.split('+').collect(),
-        };
-        let (mods, key) = parts.split_at(parts.len().saturating_sub(1));
-        for m in mods {
-            out.push_str(match *m {
-                "Ctrl" => "⌃",
-                "Alt" => "⌥",
-                "Shift" => "⇧",
-                "Cmd" => "⌘",
-                x => x,
-            });
-        }
-        out.push_str(match key.first().copied().unwrap_or("") {
-            "Space" => "Space",
-            "Escape" => "Esc",
-            "Home" => "↖",
-            k => k,
-        });
-        out
-    } else {
-        s.replace("Cmd", "Ctrl")
-    }
-}
-
-/// Parse "Cmd+Shift+K" into modifiers + key.
-pub fn parse_shortcut(s: &str) -> Option<(egui::Modifiers, egui::Key)> {
-    let mut m = egui::Modifiers::NONE;
-    let mut key = None;
-    // The plus key itself is written `+` or `Cmd++`.
-    let (head, plus) = match s.strip_suffix("++") {
-        Some(h) => (h, true),
-        None if s == "+" => ("", true),
-        None => (s, false),
-    };
-    let mut parts: Vec<&str> = if head.is_empty() { vec![] } else { head.split('+').collect() };
-    if plus {
-        parts.push("+");
-    }
-    for p in parts {
-        match p {
-            "Cmd" => {
-                m.command = true;
-                m.mac_cmd = cfg!(target_os = "macos");
-                if !cfg!(target_os = "macos") {
-                    m.ctrl = true;
-                }
-            }
-            "Physical" => {}
-            "Shift" => m.shift = true,
-            "Alt" => m.alt = true,
-            "Ctrl" => m.ctrl = true,
-            k => {
-                key = match k {
-                    ";" => Some(egui::Key::Semicolon),
-                    "'" => Some(egui::Key::Quote),
-                    "," => Some(egui::Key::Comma),
-                    "." => Some(egui::Key::Period),
-                    "/" => Some(egui::Key::Slash),
-                    "\\" => Some(egui::Key::Backslash),
-                    "=" => Some(egui::Key::Equals),
-                    "-" => Some(egui::Key::Minus),
-                    "`" => Some(egui::Key::Backtick),
-                    "[" => Some(egui::Key::OpenBracket),
-                    "]" => Some(egui::Key::CloseBracket),
-                    "Num0" => Some(egui::Key::Num0),
-                    "Num*" => None,
-                    _ => egui::Key::from_name(k),
-                }
-            }
-        }
-    }
-    key.map(|k| (m, k))
-}
-
-/// The key some keyboards report for a shifted punctuation key (`Shift+=` arrives as `+`).
-fn shifted_alias(k: egui::Key) -> Option<egui::Key> {
-    use egui::Key::*;
-    Some(match k {
-        Equals => Plus,
-        Semicolon => Colon,
-        OpenBracket => OpenCurlyBracket,
-        CloseBracket => CloseCurlyBracket,
-        Slash => Questionmark,
-        Backslash => Pipe,
-        _ => return None,
-    })
-}
-
-/// A key binding: modifiers, key, command id and bound params.
-pub type Binding = (egui::Modifiers, egui::Key, String, Value);
-
-/// All bindings of the active keyboard shortcut preset, most modifiers first.
-pub fn bindings(session: &effectcraft_engine::Session) -> Vec<Binding> {
-    let mut v: Vec<Binding> = Vec::new();
-    for (sc, b) in session.shortcuts().bindings() {
-        if sc.starts_with("Physical+") {
-            continue;
-        }
-        // Off macOS `Cmd` is Ctrl, so a custom Ctrl+Cmd shortcut would
-        // steal the plain Cmd one: such macOS-only shortcuts aren't bound there.
-        if !cfg!(target_os = "macos") && sc.split('+').any(|p| p == "Ctrl") && sc.split('+').any(|p| p == "Cmd") {
-            continue;
-        }
-        if let Some((m, k)) = parse_shortcut(sc) {
-            if m.shift
-                && let Some(alias) = shifted_alias(k)
-            {
-                v.push((m, alias, b.command.clone(), b.params.clone()));
-            }
-            v.push((m, k, b.command.clone(), b.params.clone()));
-        }
-    }
-    v.sort_by_key(|(m, ..)| std::cmp::Reverse(m.command as u8 + m.shift as u8 + m.alt as u8 + m.ctrl as u8));
-    v
-}
-
-fn mods_match(want: egui::Modifiers, got: egui::Modifiers) -> bool {
-    want.command == got.command && want.shift == got.shift && want.alt == got.alt && (want.ctrl == got.ctrl || got.command && cfg!(not(target_os = "macos")))
-}
-
-/// Whether the `key`+`mods` chord is the current binding of `command` in the active preset
-/// (so callers that must match a shortcut themselves — like the viewer's text editor, which
-/// holds the keyboard while the shortcut dispatcher is skipped — follow rebinds).
-/// `Physical+`-only bindings never match here, exactly as for the app-wide dispatcher.
-pub fn chord_matches(session: &effectcraft_engine::Session, command: &str, key: egui::Key, mods: egui::Modifiers) -> bool {
-    bindings(session).into_iter().any(|(m, k, id, _)| id == command && k == key && mods_match(m, mods))
-}
-
-/// Whether a Deselect All chord matched by [`chord_matches`] may run while a text editor holds
-/// the keyboard. Chords carrying Cmd/Ctrl/Alt are command chords (the editor treats them as
-/// such for undo and the rest), and function keys never type, so those forward from the editor;
-/// a chord that could instead produce a character — a bare or Shift-only letter, digit or
-/// punctuation key, as from a pathological bare-letter rebinding — stays with the editor so
-/// typing keeps working, the same invariant the app-wide dispatcher honors by skipping
-/// focused text fields.
-pub fn forwardable_during_text_edit(mods: egui::Modifiers, key: egui::Key) -> bool {
-    mods.command || mods.ctrl || mods.alt || (egui::Key::F1..=egui::Key::F35).contains(&key)
-}
-
-/// Set (egui temp data) from a plain Spacebar press until its release while a tap would still
-/// run the Spacebar shortcut.
-/// The system clipboard's text of this frame's paste event, for the Edit ▸ Paste it runs.
-fn system_paste_id() -> egui::Id {
-    egui::Id::unique("menus-system-paste")
-}
-
-/// The temp-data id of the flag set by a plain Space press and taken on its release, so a tap
-/// runs the Space shortcut while holding Space stays the Hand tool.
-fn space_tap_id() -> egui::Id {
-    egui::Id::unique("spacebar-tap")
-}
-
-/// The modifiers held when this frame's input began: the state the last pass ended with, if it
-/// ran this (egui keeps only the state after the frame's events). Records this pass's state.
-fn modifiers_at_start(ctx: &egui::Context) -> Option<egui::Modifiers> {
-    let id = egui::Id::unique("shortcut-modifiers");
-    let pass = ctx.cumulative_pass_nr();
-    let now = ctx.input(|i| i.modifiers);
-    ctx.data_mut(|d| {
-        let last = d.get_temp::<(u64, egui::Modifiers, Option<egui::Modifiers>)>(id);
-        if let Some((p, _, start)) = last
-            && p == pass
-        {
-            return start;
-        }
-        let start = last.and_then(|(p, m, _)| (p.checked_add(1) == Some(pass)).then_some(m));
-        d.insert_temp(id, (pass, now, start));
-        start
-    })
-}
-
-/// Only Shift held (Shift+Delete, not Ctrl/Alt+Shift+Delete).
-fn only_shift(m: egui::Modifiers) -> bool {
-    m.shift && !m.alt && !m.ctrl && !m.command && !m.mac_cmd
-}
-
-/// Dispatch keyboard shortcuts (skipped while typing in a text field).
-pub fn handle_shortcuts(app: &mut EffectcraftApp, ctx: &egui::Context) {
-    handle_shortcuts_impl(app, ctx, false);
-}
-
-/// Tab can acquire widget focus while the current frame is drawn. Dispatch its application
-/// binding only afterward, and only when no widget owned focus before or after layout.
-pub fn handle_tab_shortcut(app: &mut EffectcraftApp, ctx: &egui::Context) {
-    if ctx.input(|i| i.key_pressed(egui::Key::Tab)) {
-        handle_shortcuts_impl(app, ctx, true);
-    }
-}
-
-fn handle_shortcuts_impl(app: &mut EffectcraftApp, ctx: &egui::Context, tab_only: bool) {
-    let start = modifiers_at_start(ctx);
-    // Dialog cancellation owns Escape even when a text field has keyboard focus.
-    if !tab_only && app.dialog.is_some() && ctx.input(|i| i.key_pressed(egui::Key::Escape)) {
-        // A popup or colour picker takes Escape first (the picker goes back to its original colour).
-        if crate::panels::shortcut_editor::recording(app)
-            || crate::panels::shortcut_editor::confirming(app)
-            || egui::Popup::is_any_open(ctx)
-            || crate::color_picker::open_recently(ctx)
-        {
-            return;
-        }
-        ctx.input_mut(|i| i.consume_key(egui::Modifiers::NONE, egui::Key::Escape));
-        if app.dialog == Some(crate::Dialog::LayerStyles) {
-            crate::panels::layer_styles_dialog::finish(app, false);
-        } else if app.dialog == Some(crate::Dialog::Info) {
-            crate::panels::forms::close_info(app);
-        } else {
-            if app.dialog == Some(crate::Dialog::Settings)
-                && let Some(p) = app.dialog_state.prefs_snapshot.take()
-            {
-                app.session.prefs = p;
-                app.session.prefs_changed();
-            }
-            if app.dialog == Some(crate::Dialog::UnsavedChanges) {
-                app.dialog_state.unsaved.command = None;
-            }
-            app.dialog = None;
-        }
-        return;
-    }
-    // A mouse button down while Spacebar is held belongs to the Hand tool: its release won't
-    // preview.
-    if ctx.input(|i| i.pointer.any_down()) || ctx.egui_wants_keyboard_input() {
-        ctx.data_mut(|d| d.remove::<bool>(space_tap_id()));
-    }
-    // While a menu or popup list is open, keys go to it, not to the app (Space must not start a
-    // preview behind the menu, #279).
-    if ctx.egui_wants_keyboard_input() || crate::widgets::any_menu_open(ctx) {
-        return;
-    }
-    // Text editing in the viewer takes the clipboard events itself.
-    let clipboard = app.session.state.text_edit.is_none();
-    let project = app.ui.focused == PanelKind::Project;
-    // The paste event's text: Edit ▸ Paste pastes SVG markup as a shape layer.
-    let pasted =
-        if clipboard { ctx.input(|i| i.events.iter().rev().find_map(|e| if let egui::Event::Paste(t) = e { Some(t.clone()) } else { None })) } else { None };
-    let mut events: Vec<(egui::Key, egui::Modifiers, bool, Option<egui::Key>)> = ctx.input(|i| {
-        // The windowing layer turns Ctrl+C / Ctrl+X / Ctrl+V into clipboard events instead of
-        // key presses: map them back to the keys (with the modifiers held) so Edit ▸ Copy, Cut,
-        // Paste and their variants (Ctrl+Alt+C…) run. Clipboard events carry no modifiers and
-        // `i.modifiers` is the state after all of the frame's events, so each is read with the
-        // modifiers where it is in the stream: walk the events from the frame's starting state.
-        // `None` when that isn't known.
-        let changed = i.events.iter().any(|e| matches!(e, egui::Event::ModifiersChanged(_) | egui::Event::WindowFocused(false)));
-        let mut at = if changed { start } else { Some(i.modifiers) };
-        let held = |at: Option<egui::Modifiers>| at.filter(|m| m.command).unwrap_or(egui::Modifiers::COMMAND);
-        let mut out = Vec::new();
-        for e in &i.events {
-            match e {
-                egui::Event::ModifiersChanged(m) => at = Some(*m),
-                // egui forgets the modifiers held when the window loses focus.
-                egui::Event::WindowFocused(false) => at = Some(egui::Modifiers::NONE),
-                egui::Event::Key { key, physical_key, pressed: true, modifiers, repeat, .. }
-                    if !*repeat
-                        || matches!(
-                            key,
-                            egui::Key::PageUp | egui::Key::PageDown | egui::Key::ArrowLeft | egui::Key::ArrowRight | egui::Key::ArrowUp | egui::Key::ArrowDown
-                        ) =>
-                {
-                    out.push((*key, *modifiers, true, *physical_key));
-                }
-                egui::Event::Key { key: egui::Key::Space, pressed: false, .. } => out.push((egui::Key::Space, egui::Modifiers::NONE, false, None)),
-                egui::Event::Copy if clipboard => out.push((egui::Key::C, held(at), true, None)),
-                // On Windows, Shift+Delete is the old Cut key and arrives as Cut too. The Project
-                // panel has no clipboard: there a Cut with only Shift held is Shift+Delete (Delete
-                // Project Items Without Confirmation). Never when the modifiers aren't known.
-                egui::Event::Cut if clipboard && project && at.is_some_and(only_shift) => {
-                    out.push((egui::Key::Delete, egui::Modifiers::SHIFT, true, None));
-                }
-                egui::Event::Cut if clipboard => out.push((egui::Key::X, held(at), true, None)),
-                egui::Event::Paste(_) if clipboard => out.push((egui::Key::V, held(at), true, None)),
-                _ => {}
-            }
-        }
-        out
-    });
-    events.retain(|(key, _, _, _)| (*key == egui::Key::Tab) == tab_only);
-    // Numpad * (or `*` typed with Shift+8): Add Marker (#275). egui has no key for it, so it
-    // comes as text.
-    if !tab_only && clipboard && app.dialog.is_none() && ctx.input(|i| i.events.iter().any(|e| matches!(e, egui::Event::Text(t) if t == "*"))) {
-        let bound = app.session.shortcuts().bindings().into_iter().find(|(k, _)| *k == "Num*").map(|(_, b)| (b.command.clone(), b.params.clone()));
-        // As in After Effects, it marks the selected layers; only with none selected does it add
-        // a composition marker (#976).
-        let bound = bound.map(|(id, params)| {
-            if id == "comp.addMarker" && !app.session.state.selected_layers.is_empty() { ("layer.addMarker".to_owned(), params) } else { (id, params) }
-        });
-        if let Some((id, params)) = bound
-            && let Err(e) = invoke(app, ctx, &id, if params.is_null() { json!({}) } else { params })
-        {
-            app.ui.status = e;
-        }
-    }
-    if events.is_empty() {
-        return;
-    }
-    let binds = bindings(&app.session);
-    for (key, mods, pressed, physical_key) in events {
-        // Plain Spacebar runs its shortcut (Play Current Preview) on the release: held, it is
-        // the Hand tool (After Effects), and a drag with it must not start or stop playback.
-        if key == egui::Key::Space && (!pressed || !mods.any()) {
-            if pressed {
-                if app.dialog.is_none() {
-                    ctx.data_mut(|d| d.insert_temp(space_tap_id(), true));
-                }
-                continue;
-            }
-            if !ctx.data_mut(|d| d.remove_temp::<bool>(space_tap_id())).unwrap_or(false) {
-                continue;
-            }
-        }
-        // Escape closes dialogs.
-        if key == egui::Key::Escape && app.dialog.is_some() {
-            // Escape while recording a shortcut cancels the recording, not the editor; so does
-            // Escape in its Delete Preset prompt.
-            if crate::panels::shortcut_editor::recording(app) || crate::panels::shortcut_editor::confirming(app) {
-                continue;
-            }
-            if app.dialog == Some(crate::Dialog::Info) {
-                crate::panels::forms::close_info(app);
-                continue;
-            }
-            // Escape in Settings is Cancel: restore the settings from when it opened.
-            if app.dialog == Some(crate::Dialog::Settings)
-                && let Some(p) = app.dialog_state.prefs_snapshot.take()
-            {
-                app.session.prefs = p;
-                app.session.prefs_changed();
-            }
-            app.dialog = None;
-            continue;
-        }
-        if app.dialog.is_some() {
-            continue;
-        }
-        // Enter in the Project panel renames the selected item (handled by the panel).
-        if key == egui::Key::Enter && !mods.any() && app.ui.focused == PanelKind::Project {
-            continue;
-        }
-        // The Project panel has its own selection; a previously selected Timeline layer
-        // must not be deleted while the Project panel has focus.
-        if matches!(key, egui::Key::Delete | egui::Key::Backspace) && !mods.any() {
-            if matches!(app.ui.focused, PanelKind::Composition | PanelKind::Viewer(_)) && !app.session.state.camera_points.is_empty() {
-                if let Err(e) = run_engine(app, ctx, "camera.deletePoints", json!({})) {
-                    app.ui.status = e;
-                }
-                ctx.input_mut(|i| i.consume_key(egui::Modifiers::NONE, key));
-                continue;
-            }
-            // The queue panel consumes the event after its selection state is drawn.
-            if app.ui.focused == PanelKind::RenderQueue {
-                continue;
-            }
-            let _ = invoke(app, ctx, "edit.clear", json!({}));
-            continue;
-        }
-        // Explicit physical bindings distinguish keys that a layout reports with the same
-        // logical name (for example AZERTY's minus and right parenthesis).
-        let physical = physical_key.and_then(|key| {
-            app.session.shortcuts().bindings().into_iter().find_map(|(sc, b)| {
-                let (m, k) = parse_shortcut(sc.strip_prefix("Physical+")?)?;
-                (k == key && mods_match(m, mods)).then(|| (b.command.clone(), b.params.clone()))
-            })
-        });
-        if let Some((id, params)) = physical {
-            if let Err(e) = invoke(app, ctx, &id, if params.is_null() { json!({}) } else { params }) {
-                app.ui.status = e;
-            }
-            continue;
-        }
-        if let Some((_, _, id, params)) = binds.iter().filter(|(m, k, ..)| *k == key && mods_match(*m, mods)).min_by_key(|(_, _, id, params)| {
-            // The focused panel wins over an application command sharing its chord.
-            let key = effectcraft_engine::shortcuts::binding_key(id, params);
-            app.session.shortcuts().find(&key).is_none_or(|b| b.scope != app.ui.focused.id())
-        }) {
-            let (id, params) = (id.clone(), if params.is_null() { json!({}) } else { params.clone() });
-            if id == "edit.paste"
-                && let Some(t) = &pasted
-            {
-                ctx.data_mut(|d| d.insert_temp(system_paste_id(), t.clone()));
-            }
-            if let Err(e) = invoke(app, ctx, &id, params) {
-                app.ui.status = e;
-            }
-            ctx.data_mut(|d| d.remove_temp::<String>(system_paste_id()));
-        }
-    }
-}
-
-/// The id under which [`menu_bar`] remembers which of its menus was open at the end of the last
-/// frame (its title's open look, and the hover that switches between the titles).
-fn open_menu_id() -> egui::Id {
-    egui::Id::unique("menu-bar-open")
-}
-
-/// The id under which [`menu_bar`] remembers a title press still in progress (press-and-browse).
-fn browse_menu_id() -> egui::Id {
-    egui::Id::unique("menu-bar-browse")
-}
-
-/// Draw the in-window menu bar (the engine's AE menu tree).
-///
-/// The titles open on the press, not the release (native menu bars): while one is held the menus
-/// can be browsed by moving onto them, and releasing over an entry chooses it. Hovering another
-/// title switches the open menu to it, and the open one closes on a press outside it or when the
-/// window loses focus. The pointer leaving the window — onto the OS title bar, directly above the
-/// bar — closes nothing, however long: the platform forwards none of the title bar's clicks to
-/// egui (only the cursor leaving), so there is no click to close on and a graze must not drop the
-/// menu. The closing press itself still reaches the widget under it, as a click does in After
-/// Effects.
-pub fn menu_bar(app: &mut EffectcraftApp, ui: &mut egui::Ui) {
-    let ctx = ui.ctx().clone();
-    let mut clicked: Option<(String, Value)> = None;
-    let mut nav = crate::menu_keys::Nav::default();
-    // The open menu as of the last frame: the titles are drawn before this frame can open or
-    // close anything, and what happened last frame is what they must react to.
-    let open_prev: Option<usize> = ctx.data(|d| d.get_temp(open_menu_id())).flatten();
-    if ctx.data(|d| d.get_temp(browse_menu_id())).unwrap_or(false) {
-        nav.set_browsing();
-    }
-    let mut drawn = 0;
-    ui.horizontal_centered(|ui| {
-        ui.add_space(6.0);
-        egui::MenuBar::new().config(egui::containers::menu::MenuConfig::new().style(crate::widgets::menu_style)).ui(ui, |ui| {
-            for node in effectcraft_engine::menus::menu_bar() {
-                let MenuNode::Submenu { label, children } = node else { continue };
-                // The open title takes the open button's look while its menu is up (as in AE).
-                let inactive = ui.style().visuals.widgets.inactive;
-                if open_prev == Some(drawn) {
-                    ui.style_mut().visuals.widgets.inactive = ui.style().visuals.widgets.open;
-                }
-                let mut response = ui.add(egui::Button::new(crate::i18n::label(app, "", label)));
-                ui.style_mut().visuals.widgets.inactive = inactive;
-                // A press on a title opens its menu at once (a second press on the open one closes
-                // it), and while it is held the menus below are browsable. The keyboard and the
-                // accessibility activation report `clicked` without the primary button (the press
-                // then happened somewhere else), and toggle the menu. Hovering another title
-                // switches to it once the pointer has moved: merely resting there must not take a
-                // keyboard-driven menu over.
-                let moved = ctx.input(|i| i.pointer.delta() != egui::Vec2::ZERO);
-                // With the button down elsewhere nothing is hovered, so the title under the
-                // pointer takes the highlight by hand: the hover-switch to it shows, one frame
-                // later like egui's own hover (the open title keeps its open look).
-                if moved && response.contains_pointer() && open_prev.is_some_and(|p| p != drawn) {
-                    response = response.highlight();
-                }
-                let pressed = ctx.input(|i| i.pointer.button_pressed(egui::PointerButton::Primary)) && response.hovered();
-                let cmd = if pressed {
-                    nav.set_browsing();
-                    Some(egui::SetOpenCommand::Bool(open_prev != Some(drawn)))
-                } else if response.clicked() && !response.clicked_by(egui::PointerButton::Primary) {
-                    Some(egui::SetOpenCommand::Toggle)
-                } else if moved && response.enabled() && response.contains_pointer() && open_prev.is_some_and(|p| p != drawn) {
-                    Some(egui::SetOpenCommand::Bool(true))
-                } else {
-                    None
-                };
-                let inner = egui::Popup::menu(&response)
-                    .close_behavior(egui::PopupCloseBehavior::IgnoreClicks)
-                    .style(crate::widgets::menu_style)
-                    .open_memory(cmd)
-                    .show(|ui| {
-                        ui.set_min_width(if label == "Effect" { 200.0 } else { 280.0 });
-                        let browsing = nav.browsing();
-                        crate::widgets::menu_scroll(ui, browsing, |ui| menu_nodes(app, ui, children, &mut clicked, &mut nav, 0));
-                    });
-                nav.top(&response);
-                // The titles and the open menus: a press inside them is not an outside press.
-                nav.cover(response.rect);
-                if let Some(inner) = &inner {
-                    nav.cover(inner.response.rect);
-                }
-                app.auto.add(&format!("menu.{label}"), response.rect, label);
-                drawn += 1;
-            }
-        });
-    });
-    crate::menu_keys::handle(&ctx, &nav);
-    // egui leaves the closing to us (`IgnoreClicks`), so the menus close here: at once on a press
-    // outside them (the press itself still reaches the widget below) and when the window loses
-    // focus. The pointer leaving the window closes nothing: moving onto the OS title bar fires
-    // the cursor-left event and the platform forwards none of its clicks to egui, so there is no
-    // click to close on — and a graze or a stay must not drop the menu, as in native apps.
-    if let Some(top) = nav.open_popup(&ctx) {
-        let focus_lost = ctx.input(|i| i.events.iter().any(|e| matches!(e, egui::Event::WindowFocused(false))));
-        let outside_press = ctx.input(|i| i.pointer.any_pressed() && i.pointer.interact_pos().is_some_and(|p| !nav.covers(p)));
-        if focus_lost || outside_press {
-            egui::Popup::close_id(&ctx, top);
-        }
-    }
-    if let Some((id, params)) = clicked.map(|(id, params)| menu_choice(app, id, params))
-        && let Err(e) = invoke(app, &ctx, &id, if params.is_null() { json!({}) } else { params })
-    {
-        app.ui.status = e;
-    }
-    // What the next frame starts from: the open title, and a title press still in progress.
-    let open = nav.open_index(&ctx);
-    let browsing = open.is_some() && nav.browsing() && ctx.input(|i| i.pointer.primary_down());
-    ctx.data_mut(|d| {
-        d.insert_temp(open_menu_id(), open);
-        d.insert_temp(browse_menu_id(), browsing);
-    });
-}
-
-/// The entries of top-level menu `name` (the Effect menu is the Effect Controls panel's context
-/// menu); returns the chosen command and its params.
-pub(crate) fn menu_contents(app: &mut EffectcraftApp, ui: &mut egui::Ui, name: &str) -> Option<(String, Value)> {
-    let mut clicked = None;
-    if let Some(MenuNode::Submenu { children, .. }) =
-        effectcraft_engine::menus::menu_bar().iter().find(|n| matches!(n, MenuNode::Submenu { label, .. } if label == name))
-    {
-        menu_nodes(app, ui, children, &mut clicked, &mut crate::menu_keys::Nav::default(), 0);
-    }
-    clicked.map(|(id, params)| (id, if params.is_null() { json!({}) } else { params }))
-}
-
-/// The entries `nodes` of a menu `depth` submenus deep, registered with `nav` for the keyboard.
-fn menu_nodes(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    nodes: &[MenuNode],
-    clicked: &mut Option<(String, Value)>,
-    nav: &mut crate::menu_keys::Nav,
-    depth: usize,
-) {
-    for n in nodes {
-        match n {
-            MenuNode::Separator => {
-                ui.separator();
-            }
-            MenuNode::Dynamic { name } => {
-                // Recent projects / footage / presets, undo history, shortcut slots, viewers,
-                // saved workspaces.
-                let ws = app.ui.workspace.clone();
-                let saved = app.saved_workspace_names();
-                let (entries, empty) = effectcraft_engine::menus::dynamic(&app.session, name, &dyn_ctx(&ws, &saved));
-                if entries.is_empty()
-                    && let Some(e) = empty
-                {
-                    ui.add_enabled(false, egui::Button::new((gutter(false), e)));
-                }
-                for (i, e) in entries.iter().enumerate() {
-                    let tip = match name.as_str() {
-                        "recentProjects" => app.session.prefs.recent_projects.get(i).cloned(),
-                        "recentFootage" => app.session.prefs.recent_footage.get(i).cloned(),
-                        "recentPresets" => app.session.prefs.recent_presets.get(i).cloned(),
-                        _ => None,
-                    };
-                    let r = ui.add_enabled(entry_enabled(app, e), egui::Button::new((gutter(entry_checked(app, e) == Some(true)), e.label.as_str())));
-                    let r = match &tip {
-                        Some(t) => r.on_hover_text(t),
-                        None => r,
-                    };
-                    let r = browse_hover(nav, r);
-                    app.auto.add(&format!("menu.{name}.{i}"), r.rect, &e.label);
-                    nav.entry(ui, depth, &r, false);
-                    if r.clicked() || browse_pick(nav, ui, &r) {
-                        *clicked = Some((e.command.clone(), e.params.clone()));
-                        ui.close();
-                    }
-                }
-            }
-            MenuNode::Submenu { label, children } => {
-                let ws = app.ui.workspace.clone();
-                // The generated Effect menu's category submenus draw the catalog's name (#821);
-                // every other submenu goes through the menu catalog.
-                let shown = crate::i18n::effect_category(children, label)
-                    .unwrap_or_else(|| crate::i18n::submenu(app, label, effectcraft_engine::menus::submenu_label(&app.session, label, &dyn_ctx(&ws, &[]))));
-                let browsing = nav.browsing();
-                let egui::InnerResponse { inner, response } = ui.menu_button((gutter(false), shown.as_str()), |ui| {
-                    ui.set_min_width(if children.len() > 30 { 200.0 } else { 240.0 });
-                    crate::widgets::menu_scroll(ui, browsing, |ui| menu_nodes(app, ui, children, clicked, nav, depth + 1));
-                });
-                let response = browse_hover(nav, response);
-                nav.entry(ui, depth, &response, true);
-                if inner.is_some() {
-                    // `ui.menu_button` drops the popup's own response on the floor: read it back,
-                    // so that a press inside this submenu doesn't count as an outside press.
-                    let sub = egui::containers::menu::SubMenu::id_from_widget_id(response.id);
-                    if let Some(resp) = ui.ctx().read_response(sub) {
-                        nav.cover(resp.rect);
-                    }
-                    nav.opened(depth, &response);
-                }
-            }
-            MenuNode::Item(e) => {
-                let r = browse_hover(nav, menu_entry(app, ui, e));
-                nav.entry(ui, depth, &r, false);
-                if r.clicked() || browse_pick(nav, ui, &r) {
-                    *clicked = Some((e.command.clone(), e.params.clone()));
-                    ui.close();
-                }
-            }
-        }
-    }
-}
-
-/// The row `r` highlighted while the bar is mid press-and-browse: with a button down egui reports
-/// nothing as hovered — which would leave browsing with no hover feedback at all — so the row
-/// under the pointer takes the highlight by hand. It reads as the hover look one frame later,
-/// exactly egui's own hover latency; disabled rows ignore it (`Noninteractive`), as in native
-/// menus. Context menus use their own [`crate::menu_keys::Nav`], where the bar never browses.
-fn browse_hover(nav: &crate::menu_keys::Nav, r: egui::Response) -> egui::Response {
-    if nav.browsing() && r.contains_pointer() { r.highlight() } else { r }
-}
-
-/// Whether a press-and-browse (a menu-bar title still held down) releases over entry `r`, which
-/// then chooses it like a click does. egui reports neither for it: the release is far from the
-/// press, so there is no click, and nothing but the pressed widget is hovered while a button is
-/// down, so the row has to be tested by the pointer being over it.
-fn browse_pick(nav: &crate::menu_keys::Nav, ui: &egui::Ui, r: &egui::Response) -> bool {
-    nav.browsing() && r.enabled() && r.contains_pointer() && ui.input(|i| i.pointer.button_released(egui::PointerButton::Primary))
-}
-
-/// The menu bar's submenu at `path` (`["File", "Interpret Footage"]`) in a panel's context menu,
-/// with the menu bar's labels, shortcuts and enabled state; a chosen entry goes to `clicked`.
-pub(crate) fn submenu_at(app: &mut EffectcraftApp, ui: &mut egui::Ui, path: &[&str], clicked: &mut Option<(String, Value)>) {
-    let mut nodes = effectcraft_engine::menus::menu_bar();
-    let mut found = None;
-    for label in path {
-        let Some(n) = nodes.iter().find(|n| matches!(n, MenuNode::Submenu { label: l, .. } if l == label)) else { return };
-        if let MenuNode::Submenu { children, .. } = n {
-            nodes = children;
-        }
-        found = Some(n);
-    }
-    if let Some(n) = found {
-        menu_nodes(app, ui, std::slice::from_ref(n), clicked, &mut crate::menu_keys::Nav::default(), 0);
-    }
-    if let Some((_, p)) = clicked.as_mut()
-        && p.is_null()
-    {
-        *p = json!({});
-    }
-}
-
-/// The menu bar's entry for `command` in a panel's context menu (see [`submenu_at`]).
-pub(crate) fn entry_for(app: &EffectcraftApp, ui: &mut egui::Ui, command: &str, clicked: &mut Option<(String, Value)>) {
-    if let Some((_, e)) = effectcraft_engine::menus::entries().into_iter().find(|(_, e)| e.command == command)
-        && menu_entry(app, ui, e).clicked()
-    {
-        *clicked = Some((e.command.clone(), e.params_or_empty()));
-        ui.close();
-    }
-}
-
-/// Frontend state for dynamic menus (the current workspace and the saved ones).
-pub(crate) fn dyn_ctx<'a>(workspace: &'a str, saved_workspaces: &'a [String]) -> effectcraft_engine::menus::DynCtx<'a> {
-    effectcraft_engine::menus::DynCtx { workspace: Some(workspace), saved_workspaces }
-}
-
-/// The check-mark column every menu row reserves (like macOS / After Effects menus).
-fn gutter(checked: bool) -> egui::Atom<'static> {
-    use egui::AtomExt;
-    (if checked { "✔" } else { "" }).atom_size(egui::vec2(14.0, 14.0))
-}
-
-fn menu_entry(app: &EffectcraftApp, ui: &mut egui::Ui, e: &MenuEntry) -> egui::Response {
-    let (label, check, enabled) = (entry_label(app, e), gutter(entry_checked(app, e) == Some(true)), entry_enabled(app, e));
-    // Edit ▸ Label's entries show the label's colour before its name.
-    if e.command == "edit.label"
-        && let Some(l) = e.params.get("label").and_then(Value::as_str).and_then(effectcraft_engine::color::Label::from_name)
-    {
-        let out = ui.add_enabled_ui(enabled, |ui| egui::Button::new((check, crate::widgets::label_swatch(), label)).atom_ui(ui)).inner;
-        crate::widgets::paint_label_swatch(ui, &out, l, &app.tokens);
-        return out.response;
-    }
-    let mut b = egui::Button::new((check, label));
-    if let Some(s) = entry_shortcut(app, e) {
-        b = b.shortcut_text(shortcut_text(&s));
-    }
-    ui.add_enabled(enabled, b)
-}
-
-/// View ▸ Zoom In / Zoom Out: the next standard magnification (as a share of screen pixels, so
-/// 100 % is one comp pixel per screen pixel at any display scaling) above or below `cur`, which is
-/// in points per comp pixel like the result (#882).
-fn zoom_step(cur: f32, ppp: f32, zoom_in: bool) -> f32 {
-    const STEPS: [f32; 16] = [0.015, 0.03, 0.0625, 0.125, 0.25, 0.333, 0.5, 0.66, 1.0, 1.5, 2.0, 3.0, 4.0, 8.0, 16.0, 32.0];
-    let ppp = if ppp.is_finite() && ppp > 0.0 { ppp } else { 1.0 };
-    let shown = cur * ppp;
-    let next = if zoom_in {
-        STEPS.iter().copied().find(|s| *s > shown + 1e-3).unwrap_or(32.0)
-    } else {
-        STEPS.iter().rev().copied().find(|s| *s < shown - 1e-3).unwrap_or(0.015)
-    };
-    next / ppp
-}
-
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    /// #882: at 125 % / 150 % display scaling Zoom In reaches 100 % (one comp pixel per screen
-    /// pixel), not 100 % in points (125 % / 150 % on screen).
-    #[test]
-    fn zoom_steps_land_on_whole_screen_magnifications() {
-        for ppp in [1.0f32, 1.25, 1.5, 2.0] {
-            let at_100 = zoom_step(0.7 / ppp, ppp, true);
-            assert!((at_100 * ppp - 1.0).abs() < 1e-6, "ppp {ppp}: {}", at_100 * ppp);
-            assert!((zoom_step(at_100, ppp, true) * ppp - 1.5).abs() < 1e-6);
-            assert!((zoom_step(at_100, ppp, false) * ppp - 0.66).abs() < 1e-6);
-        }
-        assert!(zoom_step(1.0, 0.0, true).is_finite());
-    }
-
-    #[test]
-    fn shortcut_passes_share_frame_start_modifiers() {
-        let ctx = egui::Context::default();
-        let mut starts = Vec::new();
-        let mut output = ctx.run_ui(egui::RawInput { events: vec![egui::Event::ModifiersChanged(egui::Modifiers::SHIFT)], ..Default::default() }, |ui| {
-            let ctx = ui.ctx();
-            starts.push(modifiers_at_start(ctx));
-            starts.push(modifiers_at_start(ctx));
-        });
-        output.textures_delta.clear();
-        assert_eq!(starts, vec![None, None]);
-        starts.clear();
-        let mut output = ctx.run_ui(egui::RawInput { events: vec![egui::Event::ModifiersChanged(egui::Modifiers::NONE)], ..Default::default() }, |ui| {
-            let ctx = ui.ctx();
-            starts.push(modifiers_at_start(ctx));
-            starts.push(modifiers_at_start(ctx));
-        });
-        output.textures_delta.clear();
-        assert_eq!(starts, vec![Some(egui::Modifiers::SHIFT), Some(egui::Modifiers::SHIFT)]);
-    }
-
-    #[test]
-    fn every_ui_shortcut_parses() {
-        for c in UI_COMMANDS {
-            if let Some(sc) = c.shortcut {
-                assert!(parse_shortcut(sc).is_some() || sc == "Num*", "{sc}");
-            }
-        }
-        for (_, e) in effectcraft_engine::menus::entries() {
-            if let Some(sc) = &e.shortcut {
-                assert!(parse_shortcut(sc).is_some() || sc == "Num*", "{} ({sc})", e.label);
-            }
-        }
-    }
-
-    #[test]
-    fn full_screen_default_is_platform_specific() {
-        let app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        let full_screen = app.session.shortcuts().shortcut_of("view.fullScreen", &Value::Null);
-        if cfg!(target_os = "macos") {
-            assert_eq!(full_screen, Some("Ctrl+Cmd+F"));
-        } else {
-            assert_eq!(full_screen, None);
-            assert_eq!(app.session.shortcuts().shortcut_of("window.maximizeApp", &Value::Null), Some("Cmd+\\"));
-        }
-    }
-
-    #[test]
-    fn ui_and_menu_shortcuts_do_not_collide() {
-        let app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        let mut seen: std::collections::BTreeMap<(String, String), (String, String)> = Default::default();
-        for (m, k, id, params) in bindings(&app.session) {
-            let key = (format!("{m:?}"), format!("{k:?}"));
-            let target = (id.clone(), params.to_string());
-            if let Some(prev) = seen.get(&key) {
-                assert_eq!(prev, &target, "{key:?} bound to {prev:?} and {target:?}");
-            } else {
-                seen.insert(key, target);
-            }
-        }
-    }
-
-    /// #336: Ctrl+\ (Cmd+\ on macOS) maximizes the application window, and again restores
-    /// it, as in After Effects.
-    #[test]
-    fn ctrl_backslash_maximizes_or_restores_the_window() {
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        let (m, k) = parse_shortcut("Cmd+\\").unwrap();
-        assert!(m.command && k == egui::Key::Backslash, "{m:?} {k:?}");
-        assert!(bindings(&app.session).iter().any(|b| (b.0, b.1) == (m, k) && b.2 == "window.maximizeApp"));
-        let ctx = egui::Context::default();
-        let run = |app: &mut EffectcraftApp, maximized: bool| {
-            let input = egui::RawInput {
-                viewports: std::iter::once((egui::ViewportId::ROOT, egui::ViewportInfo { maximized: Some(maximized), ..Default::default() })).collect(),
-                ..Default::default()
-            };
-            let mut r = Value::Null;
-            let mut out = ctx.run_ui(input, |ui| r = invoke(app, ui.ctx(), "window.maximizeApp", json!({})).unwrap());
-            out.textures_delta.clear();
-            let cmds = out.viewport_output.get(&egui::ViewportId::ROOT).map(|v| v.commands.clone()).unwrap_or_default();
-            (r, cmds)
-        };
-        let (r, cmds) = run(&mut app, false);
-        assert_eq!(r, json!({"maximized": true}));
-        assert!(cmds.contains(&egui::ViewportCommand::Maximized(true)), "{cmds:?}");
-        let (r, cmds) = run(&mut app, true);
-        assert_eq!(r, json!({"maximized": false}));
-        assert!(cmds.contains(&egui::ViewportCommand::Maximized(false)), "{cmds:?}");
-    }
-
-    /// The default keys of the keyboard-only commands parse and reach them.
-    #[test]
-    fn keyboard_only_commands_are_bound() {
-        let app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        for (id, keys) in [
-            ("time.workAreaStart", "Shift+Home"),
-            ("time.workAreaEnd", "Shift+End"),
-            ("time.previousInOut", "Cmd+Alt+Shift+ArrowLeft"),
-            ("time.nextInOut", "Cmd+Alt+Shift+ArrowRight"),
-            ("comp.workAreaToSelection", "Cmd+Alt+B"),
-            ("comp.activateRecent", "Shift+Escape"),
-            ("keys.deselectAll", "Shift+F2"),
-            ("keys.deselectAll", "Cmd+Alt+Shift+A"),
-            ("layer.extendSelectionNext", "Cmd+Shift+ArrowDown"),
-            ("layer.moveInToStart", "Alt+Home"),
-            ("layer.moveEarlier", "Alt+PageUp"),
-            ("layer.moveLater10", "Alt+Shift+PageDown"),
-            ("layer.stretchInToTime", "Cmd+Shift+,"),
-            ("layer.stretchOutToTime", "Cmd+Alt+,"),
-            ("layer.mask.selectNext", "Alt+`"),
-            ("layer.mask.selectPrevious", "Alt+Shift+`"),
-            ("layer.castsShadows", "Alt+Shift+C"),
-            ("timeline.scrollToTime", "D"),
-            ("timeline.scrollToLayer", "X"),
-            ("timeline.parentColumn", "Shift+F4"),
-            ("view.fitUpTo100", "Alt+/"),
-            ("view.nextItem", "Shift+."),
-            ("view.previousItem", "Shift+,"),
-            ("window.toggleCompTimeline", "\\"),
-            ("window.nextPanel", "Alt+Shift+."),
-            ("window.previousPanel", "Alt+Shift+,"),
-            ("window.closeAll", "Cmd+Shift+W"),
-            ("tool.camera", "C"),
-        ] {
-            assert!(bindings(&app.session).into_iter().any(|x| x.2 == id && Some((x.0, x.1)) == parse_shortcut(keys)), "{id} on {keys}");
-        }
-    }
-
-    #[test]
-    fn timeline_keys_scroll_and_toggle_the_parent_column() {
-        let ctx = egui::Context::default();
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        let run = |app: &mut EffectcraftApp, id: &str| invoke(app, &ctx, id, json!({})).unwrap();
-        // D and X leave a scroll for the Timeline to do when it is drawn.
-        run(&mut app, "timeline.scrollToTime");
-        assert_eq!(app.ui.timeline.scroll_to, Some(crate::state::ScrollTo::Time));
-        run(&mut app, "timeline.scrollToLayer");
-        assert_eq!(app.ui.timeline.scroll_to, Some(crate::state::ScrollTo::Layer));
-        // Shift+F4 shows and hides the Parent column.
-        let parent = crate::panels::timeline::column_visible(&app.ui.timeline, "parent");
-        run(&mut app, "timeline.parentColumn");
-        assert_eq!(crate::panels::timeline::column_visible(&app.ui.timeline, "parent"), !parent);
-        run(&mut app, "timeline.parentColumn");
-        assert_eq!(crate::panels::timeline::column_visible(&app.ui.timeline, "parent"), parent);
-    }
-
-    #[test]
-    fn viewer_keys_fit_and_step_through_open_comps() {
-        let ctx = egui::Context::default();
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        let run = |app: &mut EffectcraftApp, id: &str| invoke(app, &ctx, id, json!({})).unwrap();
-        let new = |app: &mut EffectcraftApp, name: &str| app.session.execute("comp.new", json!({"name": name, "duration": 4})).unwrap()["comp"].as_u64();
-        let active = |app: &EffectcraftApp| app.session.state.active_comp.map(|c| c.0);
-        // With one composition open there is nothing to step to.
-        let a = new(&mut app, "A");
-        run(&mut app, "view.nextItem");
-        assert_eq!(active(&app), a);
-        // Shift+, / Shift+.: through the open compositions, wrapping.
-        let b = new(&mut app, "B");
-        assert_eq!(active(&app), b);
-        run(&mut app, "view.nextItem");
-        assert_eq!(active(&app), a);
-        run(&mut app, "view.previousItem");
-        assert_eq!(active(&app), b);
-        // Alt+/ fits the viewer without magnifying past 100 %; Shift+/ fits fully again.
-        app.ui.viewer.zoom = Some(3.0);
-        run(&mut app, "view.fitUpTo100");
-        assert!(app.ui.viewer.zoom.is_none() && app.ui.viewer.fit_up_to_100);
-        run(&mut app, "view.fit");
-        assert!(!app.ui.viewer.fit_up_to_100);
-    }
-
-    #[test]
-    fn panel_keys_switch_cycle_and_close() {
-        let ctx = egui::Context::default();
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        let run = |app: &mut EffectcraftApp, id: &str| invoke(app, &ctx, id, json!({})).unwrap();
-        for name in ["A", "B"] {
-            app.session.execute("comp.new", json!({"name": name, "duration": 4})).unwrap();
-        }
-        // \\ switches between the Timeline and the Composition viewer.
-        app.ui.focused = PanelKind::Timeline;
-        run(&mut app, "window.toggleCompTimeline");
-        assert_eq!(app.ui.focused, PanelKind::Composition);
-        run(&mut app, "window.toggleCompTimeline");
-        assert_eq!(app.ui.focused, PanelKind::Timeline);
-        // Alt+Shift+. / Alt+Shift+,: the tabs of the focused panel's group, wrapping.
-        let group = app.ui.dock.group_of(PanelKind::Timeline);
-        assert!(group.len() > 1, "{group:?}");
-        run(&mut app, "window.nextPanel");
-        assert_eq!(app.ui.focused, group[(group.iter().position(|p| *p == PanelKind::Timeline).unwrap() + 1) % group.len()]);
-        run(&mut app, "window.previousPanel");
-        assert_eq!(app.ui.focused, PanelKind::Timeline);
-        // Ctrl+Shift+W with the Timeline active closes every composition.
-        run(&mut app, "window.closeAll");
-        assert!(app.session.state.open_comps.is_empty());
-        // With another panel active it closes that panel.
-        app.show_panel(PanelKind::Project);
-        run(&mut app, "window.closeAll");
-        assert!(!app.ui.dock.is_open(PanelKind::Project));
-    }
-
-    #[test]
-    fn c_cycles_the_camera_tools() {
-        let ctx = egui::Context::default();
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        app.ui.tool = Tool::Selection;
-        let mut seen = vec![];
-        for _ in 0..4 {
-            invoke(&mut app, &ctx, "tool.camera", json!({})).unwrap();
-            seen.push(app.ui.tool);
-        }
-        assert_eq!(seen, [Tool::Orbit, Tool::PanCamera, Tool::Dolly, Tool::Orbit]);
-    }
-
-    #[test]
-    fn dispatch_uses_the_active_custom_preset() {
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        let find = |app: &EffectcraftApp, id: &str| bindings(&app.session).into_iter().filter(|b| b.2 == id).map(|b| (b.0, b.1)).collect::<Vec<_>>();
-        let (m, k) = parse_shortcut("Cmd+Alt+Shift+Y").unwrap();
-        assert!(find(&app, "layer.newNull").contains(&(m, k)));
-        // A UI command rebound in a custom preset.
-        app.session.execute("shortcuts.set", json!({"command": "tool.hand", "keys": "Ctrl+Alt+H"})).unwrap();
-        assert_eq!(app.session.keymaps.active, "Custom");
-        let (m2, k2) = parse_shortcut("Ctrl+Alt+H").unwrap();
-        assert_eq!(find(&app, "tool.hand"), vec![(m2, k2)]);
-        app.session.execute("shortcuts.set", json!({"command": "layer.newNull", "keys": "F6"})).unwrap();
-        assert_eq!(find(&app, "layer.newNull"), vec![(egui::Modifiers::NONE, egui::Key::F6)]);
-        // The menus show the preset's shortcut.
-        let item = menu_items(&app).into_iter().find(|i| i.id == "layer.newNull").unwrap();
-        assert_eq!(item.shortcut.as_deref(), Some("F6"));
-        // Back to the default preset.
-        app.session.execute("shortcuts.preset", json!({"op": "select", "name": effectcraft_engine::shortcuts::DEFAULT_PRESET})).unwrap();
-        assert!(find(&app, "layer.newNull").contains(&(m, k)));
-    }
-
-    #[test]
-    fn renamed_label_shows_in_the_label_menu() {
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        app.set_pref("labels.1.name", json!("Sunflower")).unwrap();
-        let labels: Vec<String> = menu_items(&app).into_iter().filter(|i| i.id == "edit.label").map(|i| i.label).collect();
-        assert!(labels.contains(&"Sunflower".to_string()), "{labels:?}");
-        assert!(!labels.contains(&"Yellow".to_string()));
-    }
-
-    /// Saving anything but a project asks the save dialog for that file's extension (#293): the
-    /// project dialog, filtered to `.ecproj`, made macOS append `.ecproj` (`Frame.png.ecproj`).
-    /// Hosts with only the project dialog (the web) still get it, given the file name.
-    #[test]
-    fn save_dialogs_offer_the_file_extension() {
-        use std::cell::RefCell;
-        use std::rc::Rc;
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        app.session.execute("comp.new", json!({"name": "A", "width": 64, "height": 36, "frameRate": 30, "duration": 1})).unwrap();
-        let ctx = egui::Context::default();
-        let asked: Rc<RefCell<Vec<String>>> = Rc::default();
-        let (a, b) = (asked.clone(), asked.clone());
-        app.hooks.pick_save = Some(Box::new(move |name: &str| {
-            a.borrow_mut().push(format!("project {name}"));
-            None
-        }));
-        app.hooks.pick_save_file = Some(Box::new(move |name: &str, ext: &str| {
-            b.borrow_mut().push(format!("file {name} [{ext}]"));
-            None
-        }));
-        for id in ["comp.saveFrameAs", "render.saveCurrentPreview", "file.exportLottie", "file.saveCopyAsXml", "file.collectFiles", "file.saveAs"] {
-            invoke(&mut app, &ctx, id, json!({})).unwrap();
-        }
-        assert_eq!(
-            *asked.borrow(),
-            [
-                "file Frame.png [png]",
-                "file Preview.mp4 [mp4]",
-                "file Animation.json [json]",
-                "file Untitled Project.ecprojx [ecprojx]",
-                "file Collected Files []",
-                "project Untitled Project.ecproj",
-            ]
-        );
-        // Without the other dialog, the project one names any file.
-        app.hooks.pick_save_file = None;
-        asked.borrow_mut().clear();
-        invoke(&mut app, &ctx, "comp.saveFrameAs", json!({})).unwrap();
-        assert_eq!(*asked.borrow(), ["project Frame.png"]);
-    }
-
-    /// #511: with a host's non-blocking dialogs, a command's file dialog opens without running
-    /// a nested event loop inside the frame (a drag over the window then aborted the app on
-    /// macOS); the command runs on a later frame with the answer, and a cancelled one not at all.
-    #[test]
-    fn file_dialogs_can_answer_on_a_later_frame() {
-        use std::sync::{Arc, Mutex};
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        app.session.execute("comp.new", json!({"name": "A", "width": 64, "height": 36, "frameRate": 30, "duration": 1})).unwrap();
-        let ctx = egui::Context::default();
-        app.hooks.pick_save = Some(Box::new(|_: &str| panic!("the blocking dialog is not used")));
-        let pending: Arc<Mutex<Vec<(crate::FileDialog, crate::DialogDone)>>> = Arc::default();
-        let queue = pending.clone();
-        app.hooks.file_dialog_async = Some(Box::new(move |dialog, done| queue.lock().unwrap().push((dialog, done))));
-        assert_eq!(invoke(&mut app, &ctx, "file.saveAs", json!({})).unwrap(), json!({"dialog": "file.saveAs"}));
-        let (dialog, done) = pending.lock().unwrap().pop().expect("a dialog was shown");
-        assert_eq!(dialog, crate::FileDialog::Save { default: "Untitled Project.ecproj".into(), ext: "ecproj".into(), project: true });
-        assert!(app.session.path.is_none(), "nothing saved until the dialog answers");
-        let dir = std::env::temp_dir().join(format!("ec-dialog-answer-{}", std::process::id()));
-        std::fs::create_dir_all(&dir).unwrap();
-        let path = dir.join("Answered.ecproj");
-        // Answered from another thread, as the host's dialog does.
-        std::thread::spawn(move || done(vec![path.to_string_lossy().to_string()])).join().unwrap();
-        app.run_dialog_answers();
-        assert_eq!(app.session.path.as_deref(), Some(dir.join("Answered.ecproj").to_string_lossy().as_ref()));
-        assert!(dir.join("Answered.ecproj").is_file());
-        // Cancelled: nothing runs.
-        invoke(&mut app, &ctx, "comp.saveFrameAs", json!({})).unwrap();
-        let (dialog, done) = pending.lock().unwrap().pop().expect("a dialog was shown");
-        assert_eq!(dialog, crate::FileDialog::Save { default: "Frame.png".into(), ext: "png".into(), project: false });
-        done(Vec::new());
-        app.run_dialog_answers();
-        assert!(!dir.join("Frame.png").exists());
-        let _ = std::fs::remove_dir_all(&dir);
-    }
-
-    /// While a command's OS file dialog is up, floating panels' OS windows are blocked, as for
-    /// a modal dialog; a dialog that ends, answered or not, unblocks them, and Save As opens a
-    /// dialog again. A macOS sheet can end without answering (its window went away): once one of
-    /// the app's windows has the keyboard again, or keeps it as if no dialog showed, floating
-    /// windows are not left blocked.
-    #[test]
-    fn file_dialogs_block_floating_windows_only_while_up() {
-        use std::sync::{Arc, Mutex};
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        let ctx = egui::Context::default();
-        let pending: Arc<Mutex<Vec<crate::DialogDone>>> = Arc::default();
-        let queue = pending.clone();
-        app.hooks.file_dialog_async = Some(Box::new(move |_dialog, done| queue.lock().unwrap().push(done)));
-        let blocked = |app: &mut EffectcraftApp, focused: bool, time: f64| {
-            let input = egui::RawInput { focused, time: Some(time), ..Default::default() };
-            let mut out = false;
-            ctx.run_ui(input, |ui| out = app.floats_blocked(ui.ctx())).textures_delta.clear();
-            out
-        };
-        assert!(!blocked(&mut app, true, 0.0));
-        // Cancelled.
-        invoke(&mut app, &ctx, "file.saveAs", json!({})).unwrap();
-        assert!(blocked(&mut app, true, 0.1), "blocked while the dialog takes the keyboard");
-        assert!(blocked(&mut app, false, 0.2));
-        let done = pending.lock().unwrap().pop().expect("a dialog was shown");
-        done(Vec::new());
-        app.run_dialog_answers();
-        assert!(!blocked(&mut app, false, 0.3));
-        // Save As asks again; the sheet ends without answering.
-        invoke(&mut app, &ctx, "file.saveAs", json!({})).unwrap();
-        assert_eq!(pending.lock().unwrap().len(), 1, "Save As opens a dialog again");
-        assert!(blocked(&mut app, true, 1.0));
-        assert!(blocked(&mut app, false, 1.1));
-        assert!(blocked(&mut app, false, 9.0), "a dialog may stay up for long");
-        assert!(!blocked(&mut app, true, 9.1), "an app window has the keyboard again");
-        // A dialog that never takes the keyboard.
-        invoke(&mut app, &ctx, "file.saveAs", json!({})).unwrap();
-        assert!(blocked(&mut app, true, 10.0));
-        assert!(blocked(&mut app, true, 11.0));
-        assert!(!blocked(&mut app, true, 12.5));
-        // Answers of dialogs taken for gone arrive late: nothing stays blocked.
-        for done in pending.lock().unwrap().drain(..) {
-            done(Vec::new());
-        }
-        app.run_dialog_answers();
-        assert!(!blocked(&mut app, false, 13.0));
-        invoke(&mut app, &ctx, "file.saveAs", json!({})).unwrap();
-        assert!(blocked(&mut app, false, 13.1), "a later dialog blocks again");
-    }
-
-    #[test]
-    fn tga_is_available_in_import_replace_and_proxy_dialogs() {
-        use std::sync::{Arc, Mutex};
-        let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
-        let ctx = egui::Context::default();
-        let pending = Arc::new(Mutex::new(Vec::new()));
-        let queue = pending.clone();
-        app.hooks.file_dialog_async = Some(Box::new(move |dialog, _done| queue.lock().unwrap().push(dialog)));
-        for command in ["file.import", "file.importMultiple", "file.replaceFootage", "file.setProxy"] {
-            assert_eq!(invoke(&mut app, &ctx, command, json!({})).unwrap(), json!({"dialog": command}));
-            let crate::FileDialog::Open { exts, .. } = pending.lock().unwrap().pop().unwrap() else { panic!("not an open dialog") };
-            assert!(exts.iter().any(|ext| ext == "tga"), "{command}: {exts:?}");
-        }
-    }
-
-    #[test]
-    fn menu_items_cover_the_tree() {
-        assert_eq!(menus().last(), Some(&"Help"));
-        assert!(effectcraft_engine::menus::entries().len() > 500);
-    }
-}
+mod tests;
diff --git a/crates/ui-egui/src/menus/bar.rs b/crates/ui-egui/src/menus/bar.rs
new file mode 100644
index 000000000..0610233de
--- /dev/null
+++ b/crates/ui-egui/src/menus/bar.rs
@@ -0,0 +1,290 @@
+use super::entries::{entry_checked, entry_enabled, entry_label, entry_shortcut, menu_choice};
+use super::invoke::invoke;
+use super::shortcuts::shortcut_text;
+use super::{EffectcraftApp, MenuEntry, MenuNode, Value, json};
+
+/// The id under which [`menu_bar`] remembers which of its menus was open at the end of the last
+/// frame (its title's open look, and the hover that switches between the titles).
+fn open_menu_id() -> egui::Id {
+    egui::Id::unique("menu-bar-open")
+}
+
+/// The id under which [`menu_bar`] remembers a title press still in progress (press-and-browse).
+fn browse_menu_id() -> egui::Id {
+    egui::Id::unique("menu-bar-browse")
+}
+
+/// Draw the in-window menu bar (the engine's AE menu tree).
+///
+/// The titles open on the press, not the release (native menu bars): while one is held the menus
+/// can be browsed by moving onto them, and releasing over an entry chooses it. Hovering another
+/// title switches the open menu to it, and the open one closes on a press outside it or when the
+/// window loses focus. The pointer leaving the window — onto the OS title bar, directly above the
+/// bar — closes nothing, however long: the platform forwards none of the title bar's clicks to
+/// egui (only the cursor leaving), so there is no click to close on and a graze must not drop the
+/// menu. The closing press itself still reaches the widget under it, as a click does in After
+/// Effects.
+pub fn menu_bar(app: &mut EffectcraftApp, ui: &mut egui::Ui) {
+    let ctx = ui.ctx().clone();
+    let mut clicked: Option<(String, Value)> = None;
+    let mut nav = crate::menu_keys::Nav::default();
+    // The open menu as of the last frame: the titles are drawn before this frame can open or
+    // close anything, and what happened last frame is what they must react to.
+    let open_prev: Option<usize> = ctx.data(|d| d.get_temp(open_menu_id())).flatten();
+    if ctx.data(|d| d.get_temp(browse_menu_id())).unwrap_or(false) {
+        nav.set_browsing();
+    }
+    let mut drawn = 0;
+    ui.horizontal_centered(|ui| {
+        ui.add_space(6.0);
+        egui::MenuBar::new().config(egui::containers::menu::MenuConfig::new().style(crate::widgets::menu_style)).ui(ui, |ui| {
+            for node in effectcraft_engine::menus::menu_bar() {
+                let MenuNode::Submenu { label, children } = node else { continue };
+                // The open title takes the open button's look while its menu is up (as in AE).
+                let inactive = ui.style().visuals.widgets.inactive;
+                if open_prev == Some(drawn) {
+                    ui.style_mut().visuals.widgets.inactive = ui.style().visuals.widgets.open;
+                }
+                let mut response = ui.add(egui::Button::new(crate::i18n::label(app, "", label)));
+                ui.style_mut().visuals.widgets.inactive = inactive;
+                // A press on a title opens its menu at once (a second press on the open one closes
+                // it), and while it is held the menus below are browsable. The keyboard and the
+                // accessibility activation report `clicked` without the primary button (the press
+                // then happened somewhere else), and toggle the menu. Hovering another title
+                // switches to it once the pointer has moved: merely resting there must not take a
+                // keyboard-driven menu over.
+                let moved = ctx.input(|i| i.pointer.delta() != egui::Vec2::ZERO);
+                // With the button down elsewhere nothing is hovered, so the title under the
+                // pointer takes the highlight by hand: the hover-switch to it shows, one frame
+                // later like egui's own hover (the open title keeps its open look).
+                if moved && response.contains_pointer() && open_prev.is_some_and(|p| p != drawn) {
+                    response = response.highlight();
+                }
+                let pressed = ctx.input(|i| i.pointer.button_pressed(egui::PointerButton::Primary)) && response.hovered();
+                let cmd = if pressed {
+                    nav.set_browsing();
+                    Some(egui::SetOpenCommand::Bool(open_prev != Some(drawn)))
+                } else if response.clicked() && !response.clicked_by(egui::PointerButton::Primary) {
+                    Some(egui::SetOpenCommand::Toggle)
+                } else if moved && response.enabled() && response.contains_pointer() && open_prev.is_some_and(|p| p != drawn) {
+                    Some(egui::SetOpenCommand::Bool(true))
+                } else {
+                    None
+                };
+                let inner = egui::Popup::menu(&response)
+                    .close_behavior(egui::PopupCloseBehavior::IgnoreClicks)
+                    .style(crate::widgets::menu_style)
+                    .open_memory(cmd)
+                    .show(|ui| {
+                        ui.set_min_width(if label == "Effect" { 200.0 } else { 280.0 });
+                        let browsing = nav.browsing();
+                        crate::widgets::menu_scroll(ui, browsing, |ui| menu_nodes(app, ui, children, &mut clicked, &mut nav, 0));
+                    });
+                nav.top(&response);
+                // The titles and the open menus: a press inside them is not an outside press.
+                nav.cover(response.rect);
+                if let Some(inner) = &inner {
+                    nav.cover(inner.response.rect);
+                }
+                app.auto.add(&format!("menu.{label}"), response.rect, label);
+                drawn += 1;
+            }
+        });
+    });
+    crate::menu_keys::handle(&ctx, &nav);
+    // egui leaves the closing to us (`IgnoreClicks`), so the menus close here: at once on a press
+    // outside them (the press itself still reaches the widget below) and when the window loses
+    // focus. The pointer leaving the window closes nothing: moving onto the OS title bar fires
+    // the cursor-left event and the platform forwards none of its clicks to egui, so there is no
+    // click to close on — and a graze or a stay must not drop the menu, as in native apps.
+    if let Some(top) = nav.open_popup(&ctx) {
+        let focus_lost = ctx.input(|i| i.events.iter().any(|e| matches!(e, egui::Event::WindowFocused(false))));
+        let outside_press = ctx.input(|i| i.pointer.any_pressed() && i.pointer.interact_pos().is_some_and(|p| !nav.covers(p)));
+        if focus_lost || outside_press {
+            egui::Popup::close_id(&ctx, top);
+        }
+    }
+    if let Some((id, params)) = clicked.map(|(id, params)| menu_choice(app, id, params))
+        && let Err(e) = invoke(app, &ctx, &id, if params.is_null() { json!({}) } else { params })
+    {
+        app.ui.status = e;
+    }
+    // What the next frame starts from: the open title, and a title press still in progress.
+    let open = nav.open_index(&ctx);
+    let browsing = open.is_some() && nav.browsing() && ctx.input(|i| i.pointer.primary_down());
+    ctx.data_mut(|d| {
+        d.insert_temp(open_menu_id(), open);
+        d.insert_temp(browse_menu_id(), browsing);
+    });
+}
+
+/// The entries of top-level menu `name` (the Effect menu is the Effect Controls panel's context
+/// menu); returns the chosen command and its params.
+pub(crate) fn menu_contents(app: &mut EffectcraftApp, ui: &mut egui::Ui, name: &str) -> Option<(String, Value)> {
+    let mut clicked = None;
+    if let Some(MenuNode::Submenu { children, .. }) =
+        effectcraft_engine::menus::menu_bar().iter().find(|n| matches!(n, MenuNode::Submenu { label, .. } if label == name))
+    {
+        menu_nodes(app, ui, children, &mut clicked, &mut crate::menu_keys::Nav::default(), 0);
+    }
+    clicked.map(|(id, params)| (id, if params.is_null() { json!({}) } else { params }))
+}
+
+/// The entries `nodes` of a menu `depth` submenus deep, registered with `nav` for the keyboard.
+fn menu_nodes(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    nodes: &[MenuNode],
+    clicked: &mut Option<(String, Value)>,
+    nav: &mut crate::menu_keys::Nav,
+    depth: usize,
+) {
+    for n in nodes {
+        match n {
+            MenuNode::Separator => {
+                ui.separator();
+            }
+            MenuNode::Dynamic { name } => {
+                // Recent projects / footage / presets, undo history, shortcut slots, viewers,
+                // saved workspaces.
+                let ws = app.ui.workspace.clone();
+                let saved = app.saved_workspace_names();
+                let (entries, empty) = effectcraft_engine::menus::dynamic(&app.session, name, &dyn_ctx(&ws, &saved));
+                if entries.is_empty()
+                    && let Some(e) = empty
+                {
+                    ui.add_enabled(false, egui::Button::new((gutter(false), e)));
+                }
+                for (i, e) in entries.iter().enumerate() {
+                    let tip = match name.as_str() {
+                        "recentProjects" => app.session.prefs.recent_projects.get(i).cloned(),
+                        "recentFootage" => app.session.prefs.recent_footage.get(i).cloned(),
+                        "recentPresets" => app.session.prefs.recent_presets.get(i).cloned(),
+                        "recentScripts" => app.session.prefs.recent_scripts.get(i).map(|r| r.text().to_string()),
+                        _ => None,
+                    };
+                    let r = ui.add_enabled(entry_enabled(app, e), egui::Button::new((gutter(entry_checked(app, e) == Some(true)), e.label.as_str())));
+                    let r = match &tip {
+                        Some(t) => r.on_hover_text(t),
+                        None => r,
+                    };
+                    let r = browse_hover(nav, r);
+                    app.auto.add(&format!("menu.{name}.{i}"), r.rect, &e.label);
+                    nav.entry(ui, depth, &r, false);
+                    if r.clicked() || browse_pick(nav, ui, &r) {
+                        *clicked = Some((e.command.clone(), e.params.clone()));
+                        ui.close();
+                    }
+                }
+            }
+            MenuNode::Submenu { label, children } => {
+                let ws = app.ui.workspace.clone();
+                // The generated Effect menu's category submenus draw the catalog's name (#821);
+                // every other submenu goes through the menu catalog.
+                let shown = crate::i18n::effect_category(children, label)
+                    .unwrap_or_else(|| crate::i18n::submenu(app, label, effectcraft_engine::menus::submenu_label(&app.session, label, &dyn_ctx(&ws, &[]))));
+                let browsing = nav.browsing();
+                let egui::InnerResponse { inner, response } = ui.menu_button((gutter(false), shown.as_str()), |ui| {
+                    ui.set_min_width(if children.len() > 30 { 200.0 } else { 240.0 });
+                    crate::widgets::menu_scroll(ui, browsing, |ui| menu_nodes(app, ui, children, clicked, nav, depth + 1));
+                });
+                let response = browse_hover(nav, response);
+                nav.entry(ui, depth, &response, true);
+                if inner.is_some() {
+                    // `ui.menu_button` drops the popup's own response on the floor: read it back,
+                    // so that a press inside this submenu doesn't count as an outside press.
+                    let sub = egui::containers::menu::SubMenu::id_from_widget_id(response.id);
+                    if let Some(resp) = ui.ctx().read_response(sub) {
+                        nav.cover(resp.rect);
+                    }
+                    nav.opened(depth, &response);
+                }
+            }
+            MenuNode::Item(e) => {
+                let r = browse_hover(nav, menu_entry(app, ui, e));
+                nav.entry(ui, depth, &r, false);
+                if r.clicked() || browse_pick(nav, ui, &r) {
+                    *clicked = Some((e.command.clone(), e.params.clone()));
+                    ui.close();
+                }
+            }
+        }
+    }
+}
+
+/// The row `r` highlighted while the bar is mid press-and-browse: with a button down egui reports
+/// nothing as hovered — which would leave browsing with no hover feedback at all — so the row
+/// under the pointer takes the highlight by hand. It reads as the hover look one frame later,
+/// exactly egui's own hover latency; disabled rows ignore it (`Noninteractive`), as in native
+/// menus. Context menus use their own [`crate::menu_keys::Nav`], where the bar never browses.
+fn browse_hover(nav: &crate::menu_keys::Nav, r: egui::Response) -> egui::Response {
+    if nav.browsing() && r.contains_pointer() { r.highlight() } else { r }
+}
+
+/// Whether a press-and-browse (a menu-bar title still held down) releases over entry `r`, which
+/// then chooses it like a click does. egui reports neither for it: the release is far from the
+/// press, so there is no click, and nothing but the pressed widget is hovered while a button is
+/// down, so the row has to be tested by the pointer being over it.
+fn browse_pick(nav: &crate::menu_keys::Nav, ui: &egui::Ui, r: &egui::Response) -> bool {
+    nav.browsing() && r.enabled() && r.contains_pointer() && ui.input(|i| i.pointer.button_released(egui::PointerButton::Primary))
+}
+
+/// The menu bar's submenu at `path` (`["File", "Interpret Footage"]`) in a panel's context menu,
+/// with the menu bar's labels, shortcuts and enabled state; a chosen entry goes to `clicked`.
+pub(crate) fn submenu_at(app: &mut EffectcraftApp, ui: &mut egui::Ui, path: &[&str], clicked: &mut Option<(String, Value)>) {
+    let mut nodes = effectcraft_engine::menus::menu_bar();
+    let mut found = None;
+    for label in path {
+        let Some(n) = nodes.iter().find(|n| matches!(n, MenuNode::Submenu { label: l, .. } if l == label)) else { return };
+        if let MenuNode::Submenu { children, .. } = n {
+            nodes = children;
+        }
+        found = Some(n);
+    }
+    if let Some(n) = found {
+        menu_nodes(app, ui, std::slice::from_ref(n), clicked, &mut crate::menu_keys::Nav::default(), 0);
+    }
+    if let Some((_, p)) = clicked.as_mut()
+        && p.is_null()
+    {
+        *p = json!({});
+    }
+}
+
+/// The menu bar's entry for `command` in a panel's context menu (see [`submenu_at`]).
+pub(crate) fn entry_for(app: &EffectcraftApp, ui: &mut egui::Ui, command: &str, clicked: &mut Option<(String, Value)>) {
+    if let Some((_, e)) = effectcraft_engine::menus::entries().into_iter().find(|(_, e)| e.command == command)
+        && menu_entry(app, ui, e).clicked()
+    {
+        *clicked = Some((e.command.clone(), e.params_or_empty()));
+        ui.close();
+    }
+}
+
+/// Frontend state for dynamic menus (the current workspace and the saved ones).
+pub(crate) fn dyn_ctx<'a>(workspace: &'a str, saved_workspaces: &'a [String]) -> effectcraft_engine::menus::DynCtx<'a> {
+    effectcraft_engine::menus::DynCtx { workspace: Some(workspace), saved_workspaces }
+}
+
+/// The check-mark column every menu row reserves (like macOS / After Effects menus).
+fn gutter(checked: bool) -> egui::Atom<'static> {
+    use egui::AtomExt;
+    (if checked { "✔" } else { "" }).atom_size(egui::vec2(14.0, 14.0))
+}
+
+fn menu_entry(app: &EffectcraftApp, ui: &mut egui::Ui, e: &MenuEntry) -> egui::Response {
+    let (label, check, enabled) = (entry_label(app, e), gutter(entry_checked(app, e) == Some(true)), entry_enabled(app, e));
+    // Edit ▸ Label's entries show the label's colour before its name.
+    if e.command == "edit.label"
+        && let Some(l) = e.params.get("label").and_then(Value::as_str).and_then(effectcraft_engine::color::Label::from_name)
+    {
+        let out = ui.add_enabled_ui(enabled, |ui| egui::Button::new((check, crate::widgets::label_swatch(), label)).atom_ui(ui)).inner;
+        crate::widgets::paint_label_swatch(ui, &out, l, &app.tokens);
+        return out.response;
+    }
+    let mut b = egui::Button::new((check, label));
+    if let Some(s) = entry_shortcut(app, e) {
+        b = b.shortcut_text(shortcut_text(&s));
+    }
+    ui.add_enabled(enabled, b)
+}
diff --git a/crates/ui-egui/src/menus/commands.rs b/crates/ui-egui/src/menus/commands.rs
new file mode 100644
index 000000000..c162bbd3a
--- /dev/null
+++ b/crates/ui-egui/src/menus/commands.rs
@@ -0,0 +1,122 @@
+use super::UiCommand;
+
+macro_rules! uic {
+    ($id:literal, $label:literal, [$($m:literal),*], $sc:expr) => {
+        UiCommand { id: $id, label: $label, menu: &[$($m),*], shortcut: $sc }
+    };
+}
+
+/// UI-only commands (not in the AE menus; shortcuts and the command palette).
+pub const UI_COMMANDS: &[UiCommand] = &[
+    uic!("window.dockAction", "Docking Action", [], None),
+    uic!("playback.ramPreview", "Preview (Numpad 0)", [], Some("Num0")),
+    uic!("playback.preview.shiftSpacebar", "Preview (Shift+Spacebar)", [], Some("Shift+Space")),
+    uic!("playback.preview.shiftNumpad0", "Preview (Shift+Numpad 0)", [], Some("Shift+Num0")),
+    uic!("playback.preview.altNumpad0", "Preview (Alt+Numpad 0)", [], Some("Alt+Num0")),
+    uic!("playback.stop", "Stop", [], None),
+    uic!("view.fit", "Fit", [], Some("Shift+/")),
+    uic!("view.actualSize", "100%", [], Some("/")),
+    uic!("view.fitUpTo100", "Fit up to 100%", [], Some("Alt+/")),
+    uic!("view.nextItem", "Next Composition in Viewer", [], Some("Shift+.")),
+    uic!("view.previousItem", "Previous Composition in Viewer", [], Some("Shift+,")),
+    uic!("viewer.nudge.up", "Move Selected Layers Up 1 Pixel at Current Magnification", [], Some("ArrowUp")),
+    uic!("viewer.nudge.down", "Move Selected Layers Down 1 Pixel at Current Magnification", [], Some("ArrowDown")),
+    uic!("viewer.nudge.left", "Move Selected Layers Left 1 Pixel at Current Magnification", [], Some("ArrowLeft")),
+    uic!("viewer.nudge.right", "Move Selected Layers Right 1 Pixel at Current Magnification", [], Some("ArrowRight")),
+    uic!("viewer.nudge.up10", "Move Selected Layers Up 10 Pixels at Current Magnification", [], Some("Shift+ArrowUp")),
+    uic!("viewer.nudge.down10", "Move Selected Layers Down 10 Pixels at Current Magnification", [], Some("Shift+ArrowDown")),
+    uic!("viewer.nudge.left10", "Move Selected Layers Left 10 Pixels at Current Magnification", [], Some("Shift+ArrowLeft")),
+    uic!("viewer.nudge.right10", "Move Selected Layers Right 10 Pixels at Current Magnification", [], Some("Shift+ArrowRight")),
+    uic!("view.safeMargins", "Title/Action Safe", [], Some("'")),
+    uic!("view.transparencyGrid", "Transparency Grid", [], None),
+    uic!("view.fastPreviews", "Fast Previews", [], None),
+    uic!("view.theme.toggle", "Next Appearance Mode", [], None),
+    uic!("view.theme.dark", "Theme: Dark", [], None),
+    uic!("view.theme.darker", "Theme: Darker", [], None),
+    uic!("view.theme.light", "Theme: Light", [], None),
+    uic!("timeline.zoomIn", "Zoom In Time", [], Some("=")),
+    uic!("timeline.zoomOut", "Zoom Out Time", [], Some("-")),
+    uic!("timeline.zoomFit", "Zoom to Fit Comp", [], Some("Shift+;")),
+    uic!("timeline.scrollToTime", "Scroll to Current Time", [], Some("D")),
+    uic!("timeline.scrollToLayer", "Scroll Topmost Selected Layer to Top", [], Some("X")),
+    uic!("timeline.parentColumn", "Show/Hide Parent Column", [], Some("Shift+F4")),
+    uic!("timeline.zoomFrameToggle", "Zoom In to Frame Level / Out to the Whole Comp", [], Some(";")),
+    uic!("timeline.graphEditor", "Graph Editor", [], Some("Shift+F3")),
+    uic!("timeline.switchesModes", "Toggle Switches / Modes", [], Some("F4")),
+    uic!("timeline.workAreaBegin", "Set Work Area Begin", [], Some("B")),
+    uic!("timeline.workAreaEnd", "Set Work Area End", [], Some("N")),
+    uic!("timeline.moveInToTime", "Move Layer In Point to Current Time", [], Some("[")),
+    uic!("timeline.moveOutToTime", "Move Layer Out Point to Current Time", [], Some("]")),
+    uic!("timeline.trimInToTime", "Trim Layer In Point to Current Time", [], Some("Alt+[")),
+    uic!("timeline.trimOutToTime", "Trim Layer Out Point to Current Time", [], Some("Alt+]")),
+    uic!("timeline.reveal.position", "Reveal Position", [], Some("P")),
+    uic!("timeline.reveal.scale", "Reveal Scale", [], Some("S")),
+    uic!("timeline.reveal.rotation", "Reveal Rotation", [], Some("R")),
+    uic!("timeline.reveal.opacity", "Reveal Opacity", [], Some("T")),
+    uic!("timeline.reveal.anchor", "Reveal Anchor Point", [], Some("A")),
+    uic!("timeline.reveal.effects", "Reveal Effects", [], Some("E")),
+    uic!("timeline.reveal.masks", "Reveal Masks", [], Some("M")),
+    uic!("timeline.reveal.feather", "Reveal Mask Feather", [], Some("F")),
+    uic!("timeline.reveal.levels", "Reveal Audio Levels (press twice: Waveform)", [], Some("L")),
+    uic!("timeline.reveal.timeRemap", "Reveal Time Remap", [], None),
+    uic!("timeline.reveal.expressions", "Reveal Expressions", [], None),
+    uic!("timeline.reveal.maskOpacity", "Reveal Mask Opacity", [], None),
+    uic!("timeline.reveal.maskPath", "Reveal Mask Path", [], None),
+    uic!("timeline.reveal.material", "Reveal Material Options", [], None),
+    uic!("timeline.reveal.paint", "Reveal Paint, Roto Brush and Puppet", [], None),
+    uic!("timeline.reveal.selected", "Reveal Selected Properties", [], None),
+    uic!("timeline.reveal.missingEffects", "Reveal Missing Effects", [], None),
+    uic!("timeline.reveal.waveform", "Reveal Audio Waveform", [], None),
+    uic!("timeline.revealAdd.position", "Add Position to Revealed Properties", [], Some("Shift+P")),
+    uic!("timeline.revealAdd.scale", "Add Scale to Revealed Properties", [], Some("Shift+S")),
+    uic!("timeline.revealAdd.rotation", "Add Rotation to Revealed Properties", [], Some("Shift+R")),
+    uic!("timeline.revealAdd.opacity", "Add Opacity to Revealed Properties", [], Some("Shift+T")),
+    uic!("timeline.revealAdd.anchor", "Add Anchor Point to Revealed Properties", [], Some("Shift+A")),
+    uic!("timeline.revealAdd.effects", "Add Effects to Revealed Properties", [], Some("Shift+E")),
+    uic!("timeline.revealAdd.masks", "Add Masks to Revealed Properties", [], Some("Shift+M")),
+    uic!("timeline.revealAdd.feather", "Add Mask Feather to Revealed Properties", [], Some("Shift+F")),
+    uic!("timeline.revealAdd.levels", "Add Audio Levels to Revealed Properties", [], Some("Shift+L")),
+    uic!("timeline.revealAdd.animated", "Add Animated Properties to Revealed Properties", [], Some("Shift+U")),
+    uic!("timeline.column", "Show/Hide Timeline Column", [], None),
+    uic!("timeline.sourceName", "Source Name / Layer Name", [], None),
+    uic!("timeline.search", "Search Timeline", [], None),
+    uic!("flowchart.options", "Flowchart Options", [], None),
+    uic!("flowchart.graph", "Flowchart Graph", [], None),
+    uic!("timeline.collapseAll", "Collapse All", [], None),
+    uic!("timeline.twirlSelected", "Twirl Selected Layers Open / Closed", [], Some("Cmd+`")),
+    uic!("timeline.keyAt.anchor", "Add or Remove Anchor Point Keyframe", [], Some("Alt+Shift+A")),
+    uic!("timeline.keyAt.position", "Add or Remove Position Keyframe", [], Some("Alt+Shift+P")),
+    uic!("timeline.keyAt.scale", "Add or Remove Scale Keyframe", [], Some("Alt+Shift+S")),
+    uic!("timeline.keyAt.rotation", "Add or Remove Rotation Keyframe", [], Some("Alt+Shift+R")),
+    uic!("timeline.keyAt.opacity", "Add or Remove Opacity Keyframe", [], Some("Alt+Shift+T")),
+    uic!("tool.selection", "Selection Tool", [], Some("V")),
+    uic!("tool.hand", "Hand Tool", [], Some("H")),
+    uic!("tool.zoom", "Zoom Tool", [], Some("Z")),
+    uic!("tool.orbit", "Orbit Tool", [], Some("1")),
+    uic!("tool.panCamera", "Pan Camera Tool", [], Some("2")),
+    uic!("tool.dolly", "Dolly Tool", [], Some("3")),
+    uic!("tool.camera", "Camera Tools", [], Some("C")),
+    uic!("tool.rotate", "Rotation Tool", [], Some("W")),
+    uic!("tool.panBehind", "Pan Behind Tool", [], Some("Y")),
+    uic!("tool.shape", "Shape Tools", [], Some("Q")),
+    uic!("tool.pen", "Pen Tool", [], Some("G")),
+    uic!("tool.type", "Type Tools", [], Some("Cmd+T")),
+    uic!("tool.brush", "Brush Tools", [], Some("Cmd+B")),
+    uic!("tool.rotoBrush", "Roto Brush & Refine Edge Tools", [], Some("Alt+W")),
+    uic!("tool.puppet", "Puppet Tools", [], Some("Cmd+P")),
+    uic!("app.newComp", "New Composition...", [], None),
+    uic!("app.compSettings", "Composition Settings...", [], None),
+    uic!("app.solidSettings", "New Solid...", [], None),
+    uic!("app.home", "Home", [], None),
+    uic!("markers.dialog", "Marker Settings...", [], None),
+    uic!("window.maximizePanel", "Maximize Panel Under Pointer", [], Some("`")),
+    uic!("window.maximizeApp", "Maximize or Restore Application Window", [], Some("Cmd+\\")),
+    uic!("window.toggleCompTimeline", "Switch Between Composition and Timeline Panel", [], Some("\\")),
+    uic!("window.nextPanel", "Next Panel in Frame", [], Some("Alt+Shift+.")),
+    uic!("window.previousPanel", "Previous Panel in Frame", [], Some("Alt+Shift+,")),
+    uic!("window.closeAll", "Close Panel or All Viewers", [], Some("Cmd+Shift+W")),
+    uic!("window.dockPanel", "Dock Panel", [], None),
+    uic!("window.floatPanel", "Undock Panel", [], None),
+    uic!("window.closePanel", "Close Panel", [], None),
+    uic!("window.panelWindow", "Move Panel to New Window", [], None),
+];
diff --git a/crates/ui-egui/src/menus/entries.rs b/crates/ui-egui/src/menus/entries.rs
new file mode 100644
index 000000000..8fee44a72
--- /dev/null
+++ b/crates/ui-egui/src/menus/entries.rs
@@ -0,0 +1,147 @@
+use super::*;
+
+/// A menu entry for display / `ui.menu.list`.
+#[derive(Clone, Debug, serde::Serialize)]
+pub struct MenuItem {
+    pub id: String,
+    pub label: String,
+    pub path: Vec<String>,
+    pub shortcut: Option<String>,
+    pub enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub checked: Option<bool>,
+    /// Parameters bound to the entry (e.g. the effect for Effect menu items).
+    #[serde(skip_serializing_if = "Value::is_null")]
+    pub params: Value,
+}
+
+/// Top-level menus in order.
+pub fn menus() -> Vec<&'static str> {
+    effectcraft_engine::menus::top_level()
+}
+
+pub(crate) fn entry_label(app: &EffectcraftApp, e: &MenuEntry) -> String {
+    let shown = match e.command.as_str() {
+        "edit.undo" => app.session.history.undo.last().map(|u| format!("Undo {}", u.0)).unwrap_or_else(|| "Can't Undo".into()),
+        "edit.redo" => app.session.history.redo.last().map(|u| format!("Redo {}", u.0)).unwrap_or_else(|| "Can't Redo".into()),
+        // Window ▸ Layer: the layer open in the Layer panel.
+        "window.panel" if e.params.get("panel").and_then(Value::as_str) == Some("layer") => {
+            let name = app
+                .ui
+                .layer_panel
+                .and_then(|id| app.session.active_comp().and_then(|c| c.layer(effectcraft_engine::project::LayerId(id))))
+                .map(|l| l.name.clone());
+            format!("Layer: {}", name.unwrap_or_else(|| "(none)".into()))
+        }
+        _ => effectcraft_engine::menus::entry_label(&app.session, e),
+    };
+    crate::i18n::entry(app, e, shown)
+}
+
+/// The entry's shortcut in the active keyboard shortcut preset.
+pub(crate) fn entry_shortcut(app: &EffectcraftApp, e: &MenuEntry) -> Option<String> {
+    app.session.shortcuts().shortcut_of(&e.command, &e.params).map(str::to_string)
+}
+
+/// Whether panel `p` is on screen: the front tab of a floating window, or of a docked group
+/// (an open frame in a stack) that a maximized panel does not cover.
+pub(crate) fn panel_shown(app: &EffectcraftApp, p: PanelKind) -> bool {
+    if app.ui.dock.is_floating(p) {
+        return app.ui.dock.is_visible(p);
+    }
+    match app.ui.maximized.filter(|m| app.ui.dock.is_docked(*m)) {
+        Some(m) => m == p,
+        None => app.ui.dock.is_visible(p),
+    }
+}
+
+/// The command a menu entry runs when chosen from a menu: Window ▸ `<panel>` closes a panel whose
+/// entry is checked, as in After Effects (#1630). Shortcuts and agents calling `window.panel`
+/// still only show the panel.
+pub(crate) fn menu_choice(app: &EffectcraftApp, id: String, params: Value) -> (String, Value) {
+    if id == "window.panel"
+        && let Some(p) = params.get("panel").and_then(Value::as_str).and_then(PanelKind::from_name)
+        && panel_shown(app, p)
+    {
+        return ("window.closePanel".into(), params);
+    }
+    (id, params)
+}
+
+/// Check-mark state of frontend toggles (engine state is answered by the engine).
+pub(crate) fn entry_checked(app: &EffectcraftApp, e: &MenuEntry) -> Option<bool> {
+    let v = &app.ui.viewer;
+    let pstr = |k: &str| e.params.get(k).and_then(Value::as_str);
+    match e.command.as_str() {
+        "view.rulers" => Some(v.rulers),
+        "view.guides" => Some(v.guides),
+        "view.snapToGuides" => Some(v.snap_guides),
+        "view.lockGuides" => Some(v.lock_guides),
+        "view.grid" => Some(v.grid),
+        "view.snapToGrid" => Some(v.snap_grid),
+        "view.layerControls" => Some(v.show_layer_controls),
+        "playback.cacheWhenIdle" => Some(app.ui.cache_when_idle),
+        "playback.audio" => Some(app.session.prefs.preview.active().include_audio),
+        "window.workspace" => Some(pstr("name").is_some_and(|n| n == app.ui.workspace)),
+        // The Tools panel is the header toolbar: always on screen.
+        "window.panel" => Some(pstr("panel").is_some_and(|n| n.eq_ignore_ascii_case("tools") || PanelKind::from_name(n).is_some_and(|p| panel_shown(app, p)))),
+        "view.panelBackground" if e.params.get("pick").is_none() => {
+            let cur = match v.pasteboard {
+                None => "mediumGray",
+                Some([0, 0, 0]) => "black",
+                Some([0x2a, 0x2a, 0x2a]) => "darkGray",
+                Some([0xb4, 0xb4, 0xb4]) => "lightGray",
+                Some([0xff, 0xff, 0xff]) => "white",
+                Some(_) => "custom",
+            };
+            Some(pstr("color") == Some(cur))
+        }
+        _ => effectcraft_engine::menus::checked(&app.session, &e.command, &e.params),
+    }
+}
+
+pub(crate) fn entry_enabled(app: &EffectcraftApp, e: &MenuEntry) -> bool {
+    // The Project-panel enabled rules mirror the invoke redirects, so they stand down for the
+    // same reason (see the redirect block): while a text edit is open the menu items must be
+    // enabled by what their routed command can do, or the menu grays out commands that work.
+    if app.ui.focused == PanelKind::Project && app.session.state.text_edit.is_none() {
+        match e.command.as_str() {
+            "edit.duplicate" => {
+                return !app.session.state.project_selection.is_empty()
+                    && app.session.state.project_selection.iter().all(|id| app.session.project.item(*id).is_some_and(|i| !i.is_folder()));
+            }
+            "edit.selectAll" => return !app.session.project.items.is_empty(),
+            "edit.deselectAll" => return !app.session.state.project_selection.is_empty(),
+            "edit.cut" | "edit.copy" | "edit.paste" | "edit.copyWithPropertyLinks" | "edit.copyWithRelativePropertyLinks" | "edit.copyExpressionOnly" => {
+                return false;
+            }
+            _ => {}
+        }
+    }
+    if e.command == "edit.clear" && app.ui.focused == PanelKind::Project {
+        return app.session.is_enabled("project.delete");
+    }
+    if e.command == "edit.clear" && app.ui.focused == PanelKind::RenderQueue {
+        return !app.session.is_rendering() && !app.session.project.render_queue.is_empty();
+    }
+    if e.command == "window.panel" {
+        return true;
+    }
+    app.session.is_enabled(&e.command)
+}
+
+/// Every menu entry, flattened with its submenu path.
+pub fn menu_items(app: &EffectcraftApp) -> Vec<MenuItem> {
+    effectcraft_engine::menus::entries()
+        .into_iter()
+        .map(|(path, e)| MenuItem {
+            id: e.command.clone(),
+            label: entry_label(app, e),
+            path,
+            shortcut: entry_shortcut(app, e),
+            enabled: entry_enabled(app, e),
+            checked: entry_checked(app, e),
+            params: e.params.clone(),
+        })
+        .collect()
+}
diff --git a/crates/ui-egui/src/menus/frontend.rs b/crates/ui-egui/src/menus/frontend.rs
new file mode 100644
index 000000000..047c576a5
--- /dev/null
+++ b/crates/ui-egui/src/menus/frontend.rs
@@ -0,0 +1,684 @@
+use super::{EffectcraftApp, PanelKind, Resolution, Value, json};
+
+/// Run an engine command and perform the frontend events it emitted right away.
+/// Commands that fill the internal clipboard.
+const COPY_COMMANDS: &[&str] =
+    &["edit.copy", "edit.cut", "edit.copyWithPropertyLinks", "edit.copyWithRelativePropertyLinks", "edit.copyExpressionOnly", "keys.copy", "effect.copy"];
+
+/// A line for the system clipboard naming what EffectCraft copied. The system clipboard must
+/// hold something: with nothing on it, the windowing layer sends no paste event for Ctrl+V.
+fn clipboard_note(s: &effectcraft_engine::Session) -> String {
+    let st = &s.state;
+    let n = |n: usize, one: &str, many: &str| format!("EffectCraft: {n} {}", if n == 1 { one } else { many });
+    if st.clip_is_keys && !st.key_clipboard.is_empty() {
+        n(st.key_clipboard.iter().map(|c| c.keys.len()).sum(), "keyframe", "keyframes")
+    } else if !st.effect_clipboard.is_empty() {
+        n(st.effect_clipboard.len(), "effect", "effects")
+    } else if !st.contents_clipboard.is_empty() {
+        n(st.contents_clipboard.len(), "shape item", "shape items")
+    } else if st.link_clipboard.is_some() {
+        "EffectCraft: property links".into()
+    } else {
+        n(st.clipboard.len(), "layer", "layers")
+    }
+}
+
+pub(crate) fn run_engine(app: &mut EffectcraftApp, ctx: &egui::Context, id: &str, params: Value) -> Result<Value, String> {
+    // Events already queued belong to earlier invocations (`engine.execute` defers them).
+    let queued = app.session.events.len();
+    let mut r = app.session.execute(id, params).map_err(|e| e.to_string());
+    if let Err(e) = &r {
+        app.ui.status = e.clone();
+    } else if COPY_COMMANDS.contains(&id) && app.session.state.text_edit.is_none() {
+        ctx.copy_text(clipboard_note(&app.session));
+    }
+    let events = app.session.drain_events();
+    for (index, ev) in events.into_iter().enumerate() {
+        match ev {
+            effectcraft_engine::Event::Frontend { command, params } => {
+                if let Err(e) = frontend(app, ctx, &command, params) {
+                    app.ui.status = e.clone();
+                    // A frontend-only command's own failure is the command's result (#696: a
+                    // workspace save that didn't reach disk reported success). An earlier
+                    // invocation's failure only sets the status.
+                    if index >= queued && command == id && r.is_ok() {
+                        r = Err(e);
+                    }
+                }
+            }
+            other => app.session.events.push(other),
+        }
+    }
+    r
+}
+
+fn toggle(slot: &mut bool, p: &Value) -> Value {
+    *slot = p.get("value").and_then(Value::as_bool).unwrap_or(!*slot);
+    json!(*slot)
+}
+
+/// Perform a frontend command (from `Event::Frontend`).
+pub fn frontend(app: &mut EffectcraftApp, ctx: &egui::Context, id: &str, p: Value) -> Result<Value, String> {
+    let now = app.now();
+    let v = &mut app.ui.viewer;
+    Ok(match id {
+        "mediaBrowser.copySourcePath" => {
+            let path = p.get("path").and_then(Value::as_str).filter(|path| !path.is_empty()).ok_or("A source path is required")?;
+            ctx.copy_text(path.to_string());
+            json!({"path": path})
+        }
+        "effects.copyPresetsFolderPath" => {
+            if cfg!(target_arch = "wasm32") {
+                return Err("The web app has no local presets folder".into());
+            }
+            let path = crate::panels::effects_presets::presets_dir().filter(|path| !path.as_os_str().is_empty()).ok_or("No presets folder is configured")?;
+            let path = std::path::absolute(path).map_err(|e| format!("Cannot resolve the presets folder path: {e}"))?;
+            let path = path.to_str().ok_or("The presets folder path is not valid UTF-8")?;
+            ctx.copy_text(path.to_string());
+            json!({"path": path})
+        }
+        "app.checkForUpdates" | "help.checkForUpdates" => {
+            crate::updates_ui::check(app);
+            Value::Null
+        }
+        "app.about" => {
+            app.dialog = Some(crate::Dialog::About);
+            Value::Null
+        }
+        // Window ▸ <ScriptUI panel>: dock (or bring forward) the panel the script built.
+        // Audio scrubbing: one frame of audio at `time` (default the current time).
+        "playback.scrubAudio" => {
+            let cid = app.session.active_comp_id().ok_or("no composition")?;
+            let t = p.get("time").and_then(Value::as_f64).map_or(app.session.time(), effectcraft_engine::time::Tick::from_seconds_f64);
+            app.scrub_audio(cid, t, now);
+            json!({"playing": app.scrub.is_some()})
+        }
+        // View ▸ New Viewer.
+        "view.newViewer" => json!({"viewer": crate::panels::viewers::new_viewer(app)}),
+        // Reveal Layer Source / Reveal Composition: show the Project panel on the item, opening
+        // its folders and clearing the search so the row is visible.
+        "project.reveal" => {
+            let ids: Vec<effectcraft_engine::project::ItemId> = p
+                .get("items")
+                .and_then(Value::as_array)
+                .map(|items| items.iter().filter_map(Value::as_u64).map(effectcraft_engine::project::ItemId).collect())
+                .or_else(|| p.get("item").and_then(Value::as_u64).map(|item| vec![effectcraft_engine::project::ItemId(item)]))
+                .unwrap_or_default();
+            crate::panels::project::reveal(app, ctx, &ids);
+            json!({"items": ids.iter().map(|item| item.0).collect::<Vec<_>>()})
+        }
+        // Run by id (control channel, MCP): the Project panel's selection, whatever has focus.
+        "project.deleteWithoutConfirmation" => crate::panels::delete_items::delete_confirmed(app, ctx, json!({}))?,
+        // A gradient property's "Edit Gradient…" (the Timeline's value): the Gradient Editor.
+        "prop.editGradient" => crate::panels::gradient_editor::open(app, &p)?,
+        "window.scriptPanel" => {
+            let id = p.get("window").and_then(Value::as_u64).ok_or("no ScriptUI panel window")? as u32;
+            app.show_panel(PanelKind::ScriptPanel(id));
+            json!({"window": id})
+        }
+        "layer.style.options" => {
+            crate::panels::layer_styles_dialog::open(app, &p)?;
+            Value::Null
+        }
+        "app.settings" => {
+            let page = p.get("page").and_then(Value::as_str).unwrap_or("general");
+            crate::panels::settings::open(app, effectcraft_engine::prefs::page_id(page).unwrap_or("general"));
+            Value::Null
+        }
+        "app.gpuInfo" => {
+            crate::panels::dialogs::info(
+                app,
+                "GPU Information",
+                &format!(
+                    "{}Layer cache: {} MB  •  Preview cache: {} MB.",
+                    effectcraft_engine::sysinfo::gpu_summary(&app.session),
+                    app.session.layer_cache.budget() >> 20,
+                    app.frames.budget() >> 20
+                ),
+            );
+            Value::Null
+        }
+        "app.hide" | "app.hideOthers" | "app.showAll" => {
+            // The desktop app asks macOS (NSApplication hide / hideOtherApplications /
+            // unhideAllApplications); elsewhere Hide minimizes and the others don't apply.
+            if app.hooks.app_action.as_ref().is_some_and(|f| f(id)) {
+                return Ok(Value::Null);
+            }
+            match id {
+                "app.hide" => ctx.send_viewport_cmd(egui::ViewportCommand::Minimized(true)),
+                _ => return Err(format!("`{id}` is only available on macOS")),
+            }
+            Value::Null
+        }
+        "app.quit" => {
+            ctx.send_viewport_cmd(egui::ViewportCommand::Close);
+            Value::Null
+        }
+        "app.commandPalette" => {
+            app.dialog_state.palette_query = p.get("query").and_then(Value::as_str).unwrap_or_default().to_string();
+            app.dialog_state.palette_sel = 0;
+            app.dialog = Some(crate::Dialog::CommandPalette);
+            Value::Null
+        }
+        "app.keyboardShortcuts" => {
+            crate::panels::shortcut_editor::open(app);
+            Value::Null
+        }
+        "app.templates" => {
+            let kind = p.get("kind").and_then(Value::as_str).unwrap_or("renderSettings");
+            crate::panels::rq_templates::open(app, ctx, kind);
+            Value::Null
+        }
+        "renderQueue.notify" => {
+            // Render finished with Notify on: a toast, the dock/taskbar attention request, and the
+            // host's system sound (the desktop app handles `renderQueue.notify`).
+            let msg = p.get("message").and_then(Value::as_str).unwrap_or("Render finished").to_string();
+            app.toast = Some((msg, now));
+            ctx.send_viewport_cmd(egui::ViewportCommand::RequestUserAttention(egui::UserAttentionType::Informational));
+            if let Some(f) = app.hooks.app_action.as_ref() {
+                f("renderQueue.notify");
+            }
+            Value::Null
+        }
+        "app.find" => {
+            if let Some(q) = p.get("query").and_then(Value::as_str) {
+                app.ui.project_search = q.to_string();
+            }
+            app.show_panel(PanelKind::Project);
+            Value::Null
+        }
+        "playback.toggle" => {
+            // The play button and Spacebar: `{shortcut?}` picks which Preview panel shortcut's
+            // options to play with (default Spacebar).
+            let sc = match p.get("shortcut").and_then(Value::as_str) {
+                Some(k) => effectcraft_engine::preview::PreviewShortcut::parse(k).ok_or_else(|| format!("unknown preview shortcut `{k}`"))?,
+                None => effectcraft_engine::preview::PreviewShortcut::Spacebar,
+            };
+            app.toggle_play_with(now, sc);
+            json!({"playing": app.playback.playing, "shortcut": sc.id()})
+        }
+        "playback.cacheWhenIdle" => {
+            let r = toggle(&mut app.ui.cache_when_idle, &p);
+            app.set_pref("previews.cacheFramesWhenIdle", r.clone())?;
+            r
+        }
+        "playback.audio" => {
+            // Include Audio of the shortcut shown in the Preview panel.
+            let mut on = app.session.prefs.preview.active().include_audio;
+            let r = toggle(&mut on, &p);
+            app.session.execute("playback.settings.set", json!({"includeAudio": on})).map_err(|e| e.to_string())?;
+            if !on {
+                app.audio = None;
+            }
+            r
+        }
+        // Zoom In / Zoom Out act on the focused viewer: the Layer panel when it has focus, else
+        // the Composition viewer.
+        "view.zoomIn" | "view.zoomOut" if app.ui.focused == PanelKind::Layer => {
+            let cur = app.ui.layer_zoom.unwrap_or_else(|| crate::panels::layer_panel::last_fit(ctx));
+            // The Layer panel zooms in points (pixels-per-point 1).
+            let next = zoom_step(cur, 1.0, id == "view.zoomIn");
+            app.ui.layer_zoom = Some(next);
+            json!({"zoom": next, "panel": "layer"})
+        }
+        "view.zoomIn" | "view.zoomOut" => {
+            let ppp = ctx.pixels_per_point();
+            let cur = v.zoom.unwrap_or_else(|| crate::panels::viewer::last_fit(ctx));
+            let next = zoom_step(cur, ppp, id == "view.zoomIn");
+            v.zoom = Some(next);
+            json!({"zoom": next})
+        }
+        // View ▸ Resolution ▸ Custom without a factor (the engine sets the comp's resolution).
+        "view.res.custom" => {
+            let cur = match app.viewer_res() {
+                Resolution::Custom(n) => f64::from(n),
+                _ => 2.0,
+            };
+            crate::panels::dialogs::form(
+                app,
+                "Custom Resolution",
+                "view.res.custom",
+                json!({}),
+                vec![crate::panels::dialogs::Field::num("factor", "Render every n-th pixel", cur)],
+            );
+            Value::Null
+        }
+        "view.rulers" => toggle(&mut v.rulers, &p),
+        "view.guides" => toggle(&mut v.guides, &p),
+        "view.snapToGuides" => toggle(&mut v.snap_guides, &p),
+        "view.lockGuides" => toggle(&mut v.lock_guides, &p),
+        "view.grid" => toggle(&mut v.grid, &p),
+        "view.snapToGrid" => toggle(&mut v.snap_grid, &p),
+        "view.layerControls" => toggle(&mut v.show_layer_controls, &p),
+        "view.options" => {
+            app.dialog = Some(crate::Dialog::ViewOptions);
+            Value::Null
+        }
+        "view.panelBackground" => {
+            if p.get("pick").and_then(Value::as_bool) == Some(true) {
+                let [r, g, b] = v.custom_pasteboard;
+                crate::panels::dialogs::form(
+                    app,
+                    "Panel Background Color",
+                    "view.panelBackground",
+                    json!({}),
+                    vec![crate::panels::dialogs::Field::text("color", "Color (#rrggbb)", &format!("#{r:02x}{g:02x}{b:02x}"))],
+                );
+                return Ok(Value::Null);
+            }
+            let c = p.get("color").and_then(Value::as_str).unwrap_or("mediumGray");
+            v.pasteboard = match c {
+                "black" => Some([0, 0, 0]),
+                "darkGray" => Some([0x2a, 0x2a, 0x2a]),
+                "mediumGray" => None,
+                "lightGray" => Some([0xb4, 0xb4, 0xb4]),
+                "white" => Some([0xff, 0xff, 0xff]),
+                "custom" => Some(v.custom_pasteboard),
+                hex => {
+                    let c = effectcraft_engine::color::Rgba::from_hex(hex).ok_or_else(|| format!("unknown colour `{hex}`"))?;
+                    let rgb = [(c.r * 255.0).round() as u8, (c.g * 255.0).round() as u8, (c.b * 255.0).round() as u8];
+                    v.custom_pasteboard = rgb;
+                    Some(rgb)
+                }
+            };
+            Value::Null
+        }
+        // Ctrl+\ / Cmd+\, as in After Effects (#336): `{maximized}`, the window's new state.
+        "window.maximizeApp" => {
+            let maximized = !ctx.input(|i| i.viewport().maximized.unwrap_or(false));
+            ctx.send_viewport_cmd(egui::ViewportCommand::Maximized(maximized));
+            json!({"maximized": maximized})
+        }
+        "view.fullScreen" => {
+            let full = ctx.input(|i| i.viewport().fullscreen.unwrap_or(false));
+            ctx.send_viewport_cmd(egui::ViewportCommand::Fullscreen(!full));
+            json!(!full)
+        }
+        "window.panel" => {
+            let name = p.get("panel").and_then(Value::as_str).unwrap_or_default();
+            if name.eq_ignore_ascii_case("tools") {
+                app.ui.status = "The Tools panel is the toolbar in the header".into();
+                return Ok(Value::Null);
+            }
+            let panel = PanelKind::from_name(name).ok_or_else(|| format!("unknown panel `{name}`"))?;
+            app.show_panel(panel);
+            Value::Null
+        }
+        "window.workspace" => {
+            let want = p.get("name").and_then(Value::as_str).unwrap_or("Default").to_ascii_lowercase().replace(' ', "");
+            let name = app
+                .workspace_names()
+                .into_iter()
+                .find(|w| w.to_ascii_lowercase().replace(' ', "") == want)
+                .ok_or_else(|| format!("unknown workspace `{want}`"))?;
+            app.set_workspace(&name);
+            json!({"workspace": name})
+        }
+        "window.resetWorkspace" => {
+            let name = app.ui.workspace.clone();
+            app.set_workspace(&name);
+            Value::Null
+        }
+        "window.saveWorkspace" => {
+            let name = app.ui.workspace.clone();
+            app.ui.saved_workspaces.insert(name.clone(), app.ui.dock.clone());
+            app.store_saved_workspaces()?;
+            json!({"workspace": name})
+        }
+        "window.saveWorkspaceAs" => {
+            let Some(name) = p.get("name").and_then(Value::as_str).map(str::trim).filter(|n| !n.is_empty()).map(str::to_string) else {
+                crate::panels::dialogs::form(
+                    app,
+                    "New Workspace",
+                    "window.saveWorkspaceAs",
+                    json!({}),
+                    vec![crate::panels::dialogs::Field::text("name", "Name", "Untitled Workspace")],
+                );
+                return Ok(Value::Null);
+            };
+            app.ui.saved_workspaces.insert(name.clone(), app.ui.dock.clone());
+            app.ui.workspace = name.clone();
+            app.store_saved_workspaces()?;
+            json!({"workspace": name})
+        }
+        "window.editWorkspaces" => {
+            let Some(name) = p.get("name").and_then(Value::as_str).map(str::to_string) else {
+                let cur = app.ui.workspace.clone();
+                crate::panels::dialogs::form(
+                    app,
+                    "Edit Workspaces",
+                    "window.editWorkspaces",
+                    json!({}),
+                    vec![
+                        crate::panels::dialogs::Field::text("name", "Workspace", &cur),
+                        crate::panels::dialogs::Field::text("rename", "Rename to", &cur),
+                        crate::panels::dialogs::Field::bool("delete", "Delete", false),
+                    ],
+                );
+                return Ok(Value::Null);
+            };
+            let builtin = crate::dock::WORKSPACES.contains(&name.as_str());
+            if p.get("delete").and_then(Value::as_bool) == Some(true) {
+                if app.ui.saved_workspaces.remove(&name).is_none() && !builtin {
+                    return Err(format!("no workspace `{name}`"));
+                }
+                // Leave the deleted workspace first: a current workspace needs a definition.
+                if app.ui.workspace == name {
+                    app.set_workspace("Default");
+                }
+                app.store_saved_workspaces()?;
+                return Ok(json!({"deleted": name}));
+            }
+            if let Some(new) = p.get("rename").and_then(Value::as_str).map(str::trim).filter(|n| !n.is_empty() && *n != name) {
+                if builtin {
+                    return Err(format!("`{name}` is a built-in workspace: save it as a new workspace instead"));
+                }
+                let dock = app.ui.saved_workspaces.remove(&name).ok_or_else(|| format!("no workspace `{name}`"))?;
+                app.ui.saved_workspaces.insert(new.to_string(), dock);
+                if app.ui.workspace == name {
+                    app.ui.workspace = new.to_string();
+                }
+                app.store_saved_workspaces()?;
+                return Ok(json!({"renamed": new}));
+            }
+            json!({"workspaces": app.workspace_names()})
+        }
+        "view.lookAt" => {
+            let r: Vec<f64> = p.get("rect").and_then(Value::as_array).map(|a| a.iter().filter_map(Value::as_f64).collect()).unwrap_or_default();
+            if r.len() == 4 {
+                let map: Option<crate::panels::viewer::ViewerMap> = ctx.data(|d| d.get_temp(egui::Id::unique("viewer-map")));
+                if let Some(m) = map {
+                    let (rw, rh) = (((r[2] - r[0]) as f32).max(1.0), ((r[3] - r[1]) as f32).max(1.0));
+                    let zoom = ((m.area.width() - 40.0) / rw).min((m.area.height() - 40.0) / rh).clamp(0.015, 32.0);
+                    let rc = [(r[0] + r[2]) as f32 / 2.0, (r[1] + r[3]) as f32 / 2.0];
+                    let v = &mut app.ui.viewer;
+                    v.zoom = Some(zoom);
+                    v.pan = [m.comp[0] * zoom / 2.0 - rc[0] * zoom, m.comp[1] * zoom / 2.0 - rc[1] * zoom];
+                }
+            }
+            Value::Null
+        }
+        "comp.flowchart" => {
+            // Chart the active comp; Layer ▸ Reveal ▸ Reveal Layer in Project Flowchart shows
+            // layers and selects the layer's node.
+            app.ui.flowchart.root = app.session.active_comp_id().map(|c| c.0);
+            if let (Some(c), Some(l)) = (app.session.active_comp_id(), app.session.state.selected_layers.first()) {
+                app.ui.flowchart.layers = true;
+                app.ui.flowchart.selected = Some(format!("layer:{}:{}", c.0, l.0));
+            }
+            app.show_panel(PanelKind::Flowchart);
+            Value::Null
+        }
+        "comp.miniFlowchart" => {
+            let at = ctx.input(|i| i.pointer.hover_pos()).unwrap_or_else(|| ctx.content_rect().center());
+            app.ui.mini_flowchart = Some([at.x, at.y]);
+            Value::Null
+        }
+        "track.editTargetDialog" => {
+            crate::panels::tracker::open_target(app)?;
+            Value::Null
+        }
+        "track.optionsDialog" => {
+            crate::panels::tracker::open_options(app)?;
+            Value::Null
+        }
+        "layer.openLayer" => {
+            let id = p.get("layer").and_then(Value::as_u64).or_else(|| app.session.state.selected_layers.first().map(|l| l.0));
+            // Another layer opens at Fit.
+            if id != app.ui.layer_panel {
+                app.ui.layer_zoom = None;
+                app.ui.layer_pan = [0.0, 0.0];
+            }
+            app.ui.layer_panel = id;
+            app.ui.layer_view = None;
+            app.show_panel(PanelKind::Layer);
+            Value::Null
+        }
+        "app.confirmExecute" => {
+            // Settings ▸ Scripting ▸ Warn User When Executing Files.
+            let path = p.get("path").and_then(Value::as_str).unwrap_or_default().to_string();
+            crate::panels::forms::form(
+                app,
+                "A script wants to open a file",
+                "file.executeFile",
+                json!({"path": path, "confirmed": true}),
+                vec![crate::panels::forms::Field::text("path", "Open", &path)],
+            );
+            Value::Null
+        }
+        "app.showReport" => {
+            let title = p.get("title").and_then(Value::as_str).unwrap_or("Report").to_string();
+            let text = p.get("text").and_then(Value::as_str).unwrap_or_default().to_string();
+            crate::panels::dialogs::info(app, &title, &text);
+            Value::Null
+        }
+        "window.assignWorkspaceShortcut" => {
+            let mut q = p.clone();
+            q["workspace"] = json!(app.ui.workspace);
+            return run_engine(app, ctx, "window.assignWorkspaceShortcut", q);
+        }
+        "file.interpretFootage" => {
+            // Import ▸ Interpret Unlabeled Alpha As: Ask User.
+            if let Some(i) = p.get("item").and_then(Value::as_u64) {
+                app.session.state.project_selection = vec![effectcraft_engine::project::ItemId(i)];
+            }
+            crate::panels::dialogs::open_form(app, "file.interpretFootage", &json!({}));
+            Value::Null
+        }
+        // Help ▸ In-App Tutorials: the Home screen's Learn tab.
+        "help.inAppTutorials" => {
+            app.ui.start_screen = true;
+            app.ui.home_learn = true;
+            app.ui.home_templates = false;
+            Value::Null
+        }
+        // File ▸ New ▸ New Project from Template…: the Home screen's Templates tab.
+        "file.newFromTemplate" => {
+            app.ui.start_screen = true;
+            app.ui.home_learn = false;
+            app.ui.home_templates = true;
+            Value::Null
+        }
+        "effect.manage" | "anim.browsePresets" => {
+            app.show_panel(PanelKind::EffectsPresets);
+            Value::Null
+        }
+        "timeline.revealProps" => {
+            let props = p.get("props").and_then(Value::as_array).cloned().unwrap_or_default();
+            let uids = |k: &str| -> Vec<u64> { props.iter().filter_map(|x| x.get(k).and_then(Value::as_u64)).collect() };
+            let (found, with_props) = (uids("prop"), uids("layer"));
+            // The layers it looked at (`layers`), else those it found something on. Layers that
+            // have nothing to show close; the others' reveals stay.
+            let targets: Vec<u64> = match p.get("layers").and_then(Value::as_array) {
+                Some(l) => l.iter().filter_map(Value::as_u64).collect(),
+                None => with_props.clone(),
+            };
+            // The targets' earlier picks go (U after UU shows the keyframed ones only).
+            let comp = app.session.active_comp_arc();
+            let theirs = |u: u64| {
+                comp.as_ref().is_some_and(|c| {
+                    targets
+                        .iter()
+                        .filter_map(|l| c.layer(effectcraft_engine::project::LayerId(*l)))
+                        .any(|l| l.props.find(u).is_some() || l.props.find_group(u).is_some())
+                })
+            };
+            let tl = &mut app.ui.timeline;
+            tl.reveal_props.retain(|u| !theirs(*u));
+            tl.reveal_props.extend(found.iter().copied());
+            let (shown, hidden): (Vec<u64>, Vec<u64>) = targets.into_iter().partition(|l| with_props.contains(l));
+            tl.apply_reveal(&hidden, vec![]);
+            if !shown.is_empty() {
+                tl.apply_reveal(&shown, vec!["props".into()]);
+            }
+            // Properties inside effects (puppet pins…) show under their effect, twirled open.
+            for (layer, prop) in props.iter().filter_map(|x| Some((x.get("layer")?.as_u64()?, x.get("prop")?.as_u64()?))) {
+                crate::panels::timeline::open_effect_paths(app, layer, &[prop]);
+            }
+            json!({"revealed": found.len()})
+        }
+        _ => return Err(format!("`{id}` is not a frontend command")),
+    })
+}
+
+/// Commands that need a file or folder path: ask the host's file dialog when `params` lacks one.
+pub(super) fn file_dialog(app: &mut EffectcraftApp, id: &str, params: &Value) -> Option<Result<Value, String>> {
+    enum Ask {
+        Folder,
+        Import,
+        OpenProject,
+        Save(&'static str),
+        Open(&'static [&'static str]),
+    }
+    let (key, ask) = match id {
+        "file.import" | "file.importMultiple" => ("paths", Ask::Import),
+        "file.open" => ("path", Ask::OpenProject),
+        "file.save" if app.session.path.is_none() => ("path", Ask::Save("Untitled Project.ecproj")),
+        "file.saveAs" | "file.saveCopy" => ("path", Ask::Save("Untitled Project.ecproj")),
+        "comp.saveFrameAs" => ("path", Ask::Save("Frame.png")),
+        "comp.saveFrameAsPsd" => ("path", Ask::Save("Frame.psd")),
+        "comp.saveFrameAsExr" => ("path", Ask::Save("Frame.exr")),
+        "file.watchFolder" if params.get("stop").is_none() => ("folder", Ask::Save("Watch Folder")),
+        "anim.savePreset" => ("path", Ask::Save("Preset.ecpreset")),
+        "anim.applyPreset" => ("path", Ask::Open(&["ecpreset", "json"])),
+        "view.exportGuides" => ("path", Ask::Save("Guides.json")),
+        "view.importGuides" => ("path", Ask::Open(&["json"])),
+        "file.exportLottie" => ("path", Ask::Save("Animation.json")),
+        "file.importLottie" => ("path", Ask::Open(&["json", "lottie"])),
+        "file.importProject" => ("path", Ask::Open(&["ecproj", "ecprojx"])),
+        "file.importTimeline" => ("path", Ask::Open(&["xml", "fcpxml", "otio", "edl", "aaf", "omf"])),
+        "render.saveCurrentPreview" => ("path", Ask::Save("Preview.mp4")),
+        "file.runScript" if params.get("name").is_none() && params.get("recent").is_none() => ("path", Ask::Open(&["jsx", "js", "jsonl", "json", "txt"])),
+        "file.installScript" | "file.installScriptUIPanel" => ("path", Ask::Open(&["jsx", "js"])),
+        "effect.plugins.load" if params.get("folder").is_none() => ("path", Ask::Open(&["wasm", "wat"])),
+        "file.replaceFootage" => ("path", Ask::Import),
+        "file.relinkFootage" => ("folder", Ask::Folder),
+        "file.collectFiles" => ("folder", Ask::Save("Collected Files")),
+        "file.saveCopyAsXml" => ("path", Ask::Save("Untitled Project.ecprojx")),
+        "keys.rpfCameraImport" => ("path", Ask::Open(&["json", "csv", "txt"])),
+        "essential.exportTemplate" => ("path", Ask::Save("Template.ectemplate")),
+        "essential.importTemplate" => ("path", Ask::Open(&["ectemplate"])),
+        "file.setProxy" => {
+            ("path", Ask::Open(&["mp4", "mov", "m4v", "mkv", "webm", "mxf", "png", "jpg", "jpeg", "gif", "webp", "tif", "tiff", "bmp", "tga", "exr"]))
+        }
+        _ => return None,
+    };
+    if params.get(key).is_some()
+        || params.get("path").is_some()
+        || params.get("paths").is_some()
+        || params.get("steps").is_some()
+        || params.get("preset").is_some()
+    {
+        return None;
+    }
+    const MEDIA: &[&str] = &[
+        "mp4", "mov", "m4v", "mkv", "webm", "mxf", "png", "jpg", "jpeg", "gif", "webp", "tif", "tiff", "bmp", "exr", "dpx", "cin", "wav", "aif", "aiff", "mp3",
+        "flac", "ogg", "opus", "svg", "pdf", "ai", "eps", "psd", "psb", "tga", "hdr", "gltf", "glb", "obj", "stl", "fbx", "json", "csv", "tsv",
+    ];
+    // A host whose blocking dialogs are unsafe inside this frame shows the dialog without
+    // blocking — macOS: the nested event loop re-entered winit's handler on a drag over the
+    // window and aborted the app (#511); Linux: the desktop portal's answer never gets pumped,
+    // so the compositor marks the window as not responding (#1275) — and the command continues
+    // when the answer arrives.
+    if let Some(spawn) = app.hooks.file_dialog_async.as_ref() {
+        let request = match ask {
+            Ask::Folder => crate::FileDialog::Folder,
+            Ask::Import => crate::FileDialog::Open { exts: MEDIA.iter().map(|e| e.to_string()).collect(), many: key == "paths" },
+            Ask::OpenProject => crate::FileDialog::OpenProject,
+            Ask::Open(exts) => crate::FileDialog::Open { exts: exts.iter().map(|e| e.to_string()).collect(), many: false },
+            Ask::Save(default) => crate::FileDialog::save(default),
+        };
+        let tx = app.dialog_answers.0.clone();
+        let answer = crate::DialogAnswer { command: id.to_string(), key, params: params.clone(), paths: Vec::new() };
+        app.file_dialogs.opened();
+        spawn(
+            request,
+            Box::new(move |paths| {
+                let _ = tx.send(crate::DialogAnswer { paths, ..answer });
+            }),
+        );
+        return Some(Ok(json!({"dialog": id})));
+    }
+    let picked: Option<Value> = match ask {
+        Ask::Folder => {
+            let Some(f) = app.hooks.pick_folder.as_ref() else { return Some(Err("no folder dialog available (pass `folder`)".into())) };
+            f().map(Value::from)
+        }
+        Ask::Import => {
+            let Some(f) = app.hooks.pick_files.as_ref() else { return Some(Err("no file dialog available (pass `paths`)".into())) };
+            picked_value(key, f(MEDIA))
+        }
+        Ask::OpenProject => {
+            let Some(f) = app.hooks.pick_open_project.as_ref() else { return Some(Err("no file dialog available (pass `path`)".into())) };
+            f().map(|s| json!(s))
+        }
+        Ask::Open(exts) => {
+            let Some(f) = app.hooks.pick_files.as_ref() else { return Some(Err("no file dialog available (pass `path`)".into())) };
+            f(exts).first().map(|s| json!(s))
+        }
+        Ask::Save(default) => {
+            let Some(picked) = app.hooks.save_dialog(default) else { return Some(Err("no file dialog available (pass `path`)".into())) };
+            picked.map(|s| json!(s))
+        }
+    };
+    let Some(v) = picked else { return Some(Ok(Value::Null)) };
+    Some(run_with_picked(app, id, key, params, v))
+}
+
+/// The dialog's answer as the command's `key` parameter (`None`: cancelled).
+fn picked_value(key: &str, paths: Vec<String>) -> Option<Value> {
+    match (paths.is_empty(), key) {
+        (true, _) => None,
+        (false, "paths") => Some(json!(paths)),
+        (false, _) => paths.into_iter().next().map(Value::from),
+    }
+}
+
+/// A file dialog shown without blocking ([`crate::Hooks::file_dialog_async`]) answered: run its
+/// command with the picked path (nothing when it was cancelled).
+pub(crate) fn dialog_answered(app: &mut EffectcraftApp, answer: crate::DialogAnswer) {
+    let Some(v) = picked_value(answer.key, answer.paths) else { return };
+    if let Err(e) = run_with_picked(app, &answer.command, answer.key, &answer.params, v) {
+        app.ui.status = e;
+    }
+}
+
+/// Run command `id` with the path picked for it in parameter `key`.
+fn run_with_picked(app: &mut EffectcraftApp, id: &str, key: &str, params: &Value, v: Value) -> Result<Value, String> {
+    let mut p = params.as_object().cloned().unwrap_or_default();
+    p.insert(key.to_string(), v);
+    // Picked files import in the background, with the Importing card showing progress (#270).
+    if matches!(id, "file.import" | "file.importMultiple") {
+        p.insert("background".into(), Value::Bool(true));
+    }
+    // Photoshop files ask how to import them first; numbered stills whether to import them as an
+    // image sequence.
+    let picked = Value::Object(p.clone());
+    if id == "file.import" && crate::panels::dialogs::open_form(app, id, &picked)
+        || matches!(id, "file.import" | "file.importMultiple") && crate::panels::forms::open_import_sequence(app, &picked)
+    {
+        return Ok(json!({"dialog": id}));
+    }
+    // Save (untitled) becomes Save As.
+    let id = if id == "file.save" { "file.saveAs" } else { id };
+    let r = app.session.execute(id, Value::Object(p)).map_err(|e| e.to_string());
+    if let Err(e) = &r {
+        app.ui.status = e.clone();
+    }
+    r
+}
+
+/// View ▸ Zoom In / Zoom Out: the next standard magnification (as a share of screen pixels, so
+/// 100 % is one comp pixel per screen pixel at any display scaling) above or below `cur`, which is
+/// in points per comp pixel like the result (#882).
+pub(super) fn zoom_step(cur: f32, ppp: f32, zoom_in: bool) -> f32 {
+    const STEPS: [f32; 16] = [0.015, 0.03, 0.0625, 0.125, 0.25, 0.333, 0.5, 0.66, 1.0, 1.5, 2.0, 3.0, 4.0, 8.0, 16.0, 32.0];
+    let ppp = if ppp.is_finite() && ppp > 0.0 { ppp } else { 1.0 };
+    let shown = cur * ppp;
+    let next = if zoom_in {
+        STEPS.iter().copied().find(|s| *s > shown + 1e-3).unwrap_or(32.0)
+    } else {
+        STEPS.iter().rev().copied().find(|s| *s < shown - 1e-3).unwrap_or(0.015)
+    };
+    next / ppp
+}
diff --git a/crates/ui-egui/src/menus/invoke.rs b/crates/ui-egui/src/menus/invoke.rs
new file mode 100644
index 000000000..b266623f3
--- /dev/null
+++ b/crates/ui-egui/src/menus/invoke.rs
@@ -0,0 +1,692 @@
+use super::frontend::{file_dialog, frontend, run_engine};
+use super::shortcuts::system_paste_id;
+use super::*;
+
+pub fn panel_command_id(p: PanelKind) -> String {
+    format!("window.panel.{}", p.id())
+}
+
+/// The reveal shortcuts (P, S, R, T, A, E, M, F, L…). `add` (Shift+key) adds the property to
+/// (or removes it from) those already revealed instead of replacing them.
+pub fn reveal(app: &mut EffectcraftApp, kind: &str, now: f64, add: bool) {
+    // The double-press shortcuts: the same key again within 0.6 s reveals its second set (LL
+    // Waveform, TT Mask Opacity, MM all mask properties, EE Expressions, RR Time Remap, AA
+    // Material Options, PP paint / Roto Brush / Puppet, SS selected properties, FF missing
+    // effects). A single M shows Mask Path.
+    let double = |k: &str| -> Option<&'static str> {
+        Some(match k {
+            "levels" => "waveform",
+            "opacity" => "maskOpacity",
+            "masks" => "masks",
+            "effects" => "expressions",
+            "rotation" => "timeRemap",
+            "anchor" => "material",
+            "position" => "paint",
+            "scale" => "selected",
+            "feather" => "missingEffects",
+            _ => return None,
+        })
+    };
+    let pressed = kind;
+    // (With Shift a second press removes the property again instead.)
+    let again = !add && matches!(app.last_reveal.take(), Some((k, t)) if k == pressed && now - t < 0.6);
+    app.last_reveal = Some((if again { String::new() } else { pressed.to_string() }, now));
+    let kind = match (again, double(pressed)) {
+        (true, Some(d)) => {
+            // The second press replaces what the first one revealed.
+            let first = if pressed == "masks" { "maskPath" } else { pressed };
+            app.ui.timeline.reveal.retain(|k| k != first);
+            d
+        }
+        _ if pressed == "masks" => "maskPath",
+        _ => pressed,
+    };
+    let targets = reveal_targets(app);
+    let tl = &mut app.ui.timeline;
+    let present = tl.reveal.iter().any(|k| k == kind);
+    let mut kinds = tl.reveal.clone();
+    if add {
+        if present {
+            kinds.retain(|k| k != kind);
+        } else {
+            kinds.retain(|k| k != "props" || !tl.reveal_props.is_empty());
+            kinds.push(kind.to_string());
+        }
+    } else if present && kinds.len() == 1 {
+        kinds.clear();
+    } else {
+        kinds = vec![kind.to_string()];
+    }
+    tl.apply_reveal(&targets, kinds.clone());
+    crate::panels::timeline::open_revealed(app, &targets, &kinds);
+}
+
+/// Show Time Remap on the layers of a `layer.enableTimeRemap` (`layers` by id, else the
+/// selected ones) that have it now.
+fn reveal_time_remap(app: &mut EffectcraftApp, params: &Value) {
+    let asked: Vec<u64> = match params.get("layers").and_then(Value::as_array) {
+        Some(a) => a.iter().filter_map(Value::as_u64).collect(),
+        None => app.session.state.selected_layers.iter().map(|l| l.0).collect(),
+    };
+    let Some(comp) = app.session.active_comp() else { return };
+    let layers: Vec<u64> = comp.layers.iter().filter(|l| asked.contains(&l.id.0) && l.props.get("timeRemap").is_some()).map(|l| l.id.0).collect();
+    if !layers.is_empty() {
+        app.ui.timeline.apply_reveal(&layers, vec!["timeRemap".into()]);
+    }
+}
+
+/// After Alt+Shift+P (A, S, R, T) the Timeline shows the property on each layer it keyed, as in
+/// After Effects: added to what a reveal shortcut shows, else with the layer's Transform twirled
+/// open, else alone like P.
+fn reveal_keyed(app: &mut EffectcraftApp, keyed: &Value, kind: &str) {
+    let layers: std::collections::BTreeSet<u64> = keyed.as_array().into_iter().flatten().filter_map(|k| k.get("layer").and_then(Value::as_u64)).collect();
+    let Some(comp) = app.session.active_comp() else { return };
+    let tl = &mut app.ui.timeline;
+    for id in layers {
+        let shown = tl.layer_reveal.get(&id).filter(|k| !k.is_empty()).cloned();
+        match shown {
+            Some(mut kinds) => {
+                if !kinds.iter().any(|k| k == kind) {
+                    kinds.push(kind.to_string());
+                    tl.layer_reveal.insert(id, kinds);
+                }
+            }
+            None if tl.open_layers.contains(&id) => {
+                if let Some(tr) = comp.layer(effectcraft_engine::project::LayerId(id)).and_then(|l| l.transform()) {
+                    tl.open_groups.insert(tr.uid);
+                }
+            }
+            None => {
+                tl.open_layers.insert(id);
+                tl.layer_reveal.insert(id, vec![kind.to_string()]);
+            }
+        }
+    }
+}
+
+/// The layers a reveal shortcut acts on: the selected ones, else every layer of the active comp.
+fn reveal_targets(app: &EffectcraftApp) -> Vec<u64> {
+    if app.session.state.selected_layers.is_empty() {
+        app.session.active_comp().map(|c| c.layers.iter().map(|l| l.id.0).collect()).unwrap_or_default()
+    } else {
+        app.session.state.selected_layers.iter().map(|l| l.0).collect()
+    }
+}
+
+/// The arrow keys nudge the selected layers 1 pixel at the viewer's magnification (`up`,
+/// `down`, `left`, `right`), 10 with Shift (`up10`…), as After Effects does, so zoomed in
+/// they move by fractions of a comp pixel. From any panel except Project (which owns the
+/// arrow keys for its own keyboard navigation, #961); not while typing, with a dialog or
+/// menu open. With mask points selected the arrows move the points instead (#1288).
+fn nudge(app: &mut EffectcraftApp, ctx: &egui::Context, dir: &str) -> Result<Value, String> {
+    let (side, n) = match dir.strip_suffix("10") {
+        Some(side) => (side, 10.0),
+        None => (dir, 1.0),
+    };
+    let (x, y) = match side {
+        "up" => (0.0, -n),
+        "down" => (0.0, n),
+        "left" => (-n, 0.0),
+        "right" => (n, 0.0),
+        _ => return Err(format!("unknown nudge `{dir}`")),
+    };
+    let st = &app.session.state;
+    if app.ui.focused == PanelKind::Project || (st.selected_layers.is_empty() && st.selected_vertices.is_empty()) || st.text_edit.is_some() {
+        return Ok(Value::Null);
+    }
+    // Screen pixels per comp pixel.
+    let zoom = (app.ui.viewer.zoom.unwrap_or_else(|| crate::panels::viewer::last_fit(ctx)) * ctx.pixels_per_point()) as f64;
+    let k = if zoom.is_finite() && zoom > 1e-6 { 1.0 / zoom } else { 1.0 };
+    if let Some(layer) = st.selected_vertices.first().map(|v| v.layer) {
+        let d = vertex_delta(app, layer, [x * k, y * k]);
+        return run_engine(app, ctx, "mask.moveVertices", json!({"delta": d}));
+    }
+    run_engine(app, ctx, "layer.nudge", json!({"x": x * k, "y": y * k}))
+}
+
+/// A comp-space step `d` in the layer space of `layer`, where mask points live. Like a drag of
+/// the points in the viewer, every selected point takes the first one's layer space.
+fn vertex_delta(app: &EffectcraftApp, layer: effectcraft_engine::project::LayerId, d: [f64; 2]) -> [f64; 2] {
+    use effectcraft_engine::geom::vec2;
+    let s = &app.session;
+    let (Some(cid), Some(comp)) = (s.active_comp_id(), s.active_comp()) else { return d };
+    let Some(l) = comp.layer(layer) else { return d };
+    let ectx = effectcraft_engine::render::EvalCtx { project: &s.project, comp_id: cid, comp, time: s.time(), expr: s.expr.as_deref(), footage: None };
+    let (l2c, _) = crate::panels::viewer::l2c(&ectx, l);
+    l2c.inverse().map_or(d, |inv| {
+        let v = inv.apply_vec(vec2(d[0], d[1]));
+        [v.x, v.y]
+    })
+}
+
+fn no_params(p: &Value) -> bool {
+    p.as_object().is_none_or(|m| m.is_empty())
+}
+
+/// `{"comp": id}` and nothing else: Composition Settings opens on that comp instead of
+/// applying no settings to it.
+fn only_comp(p: &Value) -> Option<effectcraft_engine::project::ItemId> {
+    let m = p.as_object().filter(|m| m.len() == 1)?;
+    m.get("comp")?.as_u64().map(effectcraft_engine::project::ItemId)
+}
+
+/// Execute a UI or engine command by id.
+pub fn invoke(app: &mut EffectcraftApp, ctx: &egui::Context, id: &str, params: Value) -> Result<Value, String> {
+    if matches!(id, "effects.copyPresetsFolderPath" | "mediaBrowser.copySourcePath") {
+        return frontend(app, ctx, id, params);
+    }
+    // Layer ▸ New ▸ Text (menu, shortcut, context menus) puts an insertion point in the centre of
+    // the comp, as After Effects does, so typing goes into Source Text rather than running
+    // shortcuts (#866). `engine.execute` keeps the headless default.
+    if id == "layer.newText" && no_params(&params) {
+        return run_engine(app, ctx, id, json!({"text": "", "edit": true}));
+    }
+    // A new folder (File ▸ New, its shortcut, the Project panel's button and context menu) opens
+    // with its name ready to type, as in After Effects (#1658). The command selects it.
+    // `engine.execute` keeps the headless default.
+    if id == "project.newFolder" && no_params(&params) {
+        let r = run_engine(app, ctx, id, params);
+        if r.is_ok() {
+            app.show_panel(PanelKind::Project);
+            crate::panels::project::begin_rename(app, ctx);
+        }
+        return r;
+    }
+    // The Project-panel focus redirects apply only while no text edit is open: creating a text
+    // layer leaves focus on Project while the insertion point lives in the comp, so during an
+    // edit these commands address the text context — redirected, Deselect All would clear a
+    // project selection the user is not looking at and silently swallow the edit's own end.
+    if no_params(&params) && app.ui.focused == PanelKind::Project && app.session.state.text_edit.is_none() {
+        match id {
+            "edit.duplicate" => return run_engine(app, ctx, "project.duplicate", json!({})),
+            "edit.selectAll" => {
+                let items: Vec<u64> = crate::panels::project::visible_rows(app)
+                    .into_iter()
+                    .filter(|(id, _)| app.ui.project_search.is_empty() || app.session.project.item(*id).is_some_and(|it| !it.is_folder()))
+                    .map(|(id, _)| id.0)
+                    .collect();
+                return run_engine(app, ctx, "project.select", json!({"items":items}));
+            }
+            "edit.deselectAll" => return run_engine(app, ctx, "project.select", json!({"items":[]})),
+            "edit.cut" | "edit.copy" | "edit.paste" | "edit.copyWithPropertyLinks" | "edit.copyWithRelativePropertyLinks" | "edit.copyExpressionOnly" => {
+                return Err("Project clipboard actions are not supported yet".into());
+            }
+            _ => {}
+        }
+    }
+    // Edit ▸ Paste with SVG markup on the system clipboard pastes it as a shape layer (After
+    // Effects 26.3). Copying in the app replaces the system clipboard with a note naming what
+    // was copied, so SVG there was copied after anything copied in the app.
+    if id == "edit.paste" && no_params(&params) && app.session.state.text_edit.is_none() {
+        let text = ctx.data_mut(|d| d.remove_temp::<String>(system_paste_id())).or_else(|| app.hooks.clipboard_text.as_ref().and_then(|f| f()));
+        if let Some(svg) = text.filter(|t| effectcraft_engine::vector::is_svg_text(t)) {
+            return run_engine(app, ctx, "edit.pasteSvg", json!({"svg": svg}));
+        }
+    }
+    // Clear follows panel focus, including the Edit menu and keyboard shortcut.
+    if id == "edit.clear" && params.as_object().is_some_and(|p| p.is_empty()) && app.ui.focused == PanelKind::Project {
+        // Through `invoke`, so deleting items that compositions use still asks first (M3.16).
+        return invoke(app, ctx, "project.delete", json!({}));
+    }
+    if id == "edit.clear" && params.as_object().is_some_and(|p| p.is_empty()) && app.ui.focused == PanelKind::RenderQueue {
+        let selected = ctx.data(|d| d.get_temp::<(Vec<u64>, Option<u64>)>(egui::Id::unique("rq-ui"))).and_then(|(_, id)| id);
+        return match selected {
+            Some(item) => run_engine(app, ctx, "renderQueue.remove", json!({"item": item})),
+            None => Err("select a Render Queue item first".into()),
+        };
+    }
+    // Shift+Delete deletes the Project panel's selection without asking; it does nothing in the
+    // other panels.
+    if id == "project.deleteWithoutConfirmation" {
+        if app.ui.focused != PanelKind::Project {
+            return Ok(Value::Null);
+        }
+        return crate::panels::delete_items::delete_confirmed(app, ctx, json!({}));
+    }
+    let now = app.now();
+    // Closing a modified project asks to save it first; the command runs once answered.
+    if crate::panels::unsaved::guard(app, id, &params) {
+        return Ok(json!({"dialog": "unsavedChanges"}));
+    }
+    // Deleting Project items that compositions use asks first, as in After Effects.
+    if crate::panels::delete_items::guard(app, id, &params) {
+        return Ok(json!({"dialog": "deleteItems"}));
+    }
+    // J / K and Select All Keyframes act on what the Timeline shows (its revealed properties).
+    if matches!(id, "time.nextKey" | "time.previousKey" | "keys.selectAll")
+        && ["visible", "layers", "layer", "prop"].iter().all(|k| params.get(*k).is_none())
+        && let Some(c) = app.session.active_comp_arc()
+    {
+        let mut p = if params.is_object() { params.clone() } else { json!({}) };
+        p["visible"] = json!(crate::panels::timeline::visible_props(app, &c));
+        return run_engine(app, ctx, id, p);
+    }
+    // New Camera/Light and Camera/Light Settings without parameters open their dialogs.
+    if crate::panels::dialogs_3d::route(app, id, &params)? {
+        return Ok(Value::Null);
+    }
+    // New 3D Primitive without parameters opens its dialog.
+    if crate::panels::primitive_dialog::route(app, id, &params)? {
+        return Ok(Value::Null);
+    }
+    // Layer Settings on a solid, adjustment layer or null opens its settings dialog.
+    if crate::panels::dialogs::route_layer_settings(app, id, &params)? {
+        return Ok(Value::Null);
+    }
+    // Layer ▸ Layer Styles ▸ <style> from the menu adds the style and opens the dialog on it.
+    if crate::panels::layer_styles_dialog::route(app, id, &params)? {
+        return Ok(Value::Null);
+    }
+    // Shared docking: `window.dockAction`, craft-ui's `window.panel.*` commands, `ui.dock`,
+    // `ui.dock.reset` and `window.panelWindow`.
+    if let Some(result) = crate::dock_ui::route(app, ctx, id, &params) {
+        return result;
+    }
+    // Legacy per-panel / per-workspace ids (`window.panel.Project`, `window.workspace.default`).
+    if let Some(rest) = id.strip_prefix("window.panel.") {
+        return frontend(app, ctx, "window.panel", json!({"panel": rest}));
+    }
+    if let Some(ws) = id.strip_prefix("window.workspace.") {
+        if ws == "reset" {
+            return frontend(app, ctx, "window.resetWorkspace", json!({}));
+        }
+        return frontend(app, ctx, "window.workspace", json!({"name": ws}));
+    }
+    if let Some(t) = id.strip_prefix("tool.") {
+        // C cycles through the camera tools.
+        if t == "camera" {
+            let tools = [Tool::Orbit, Tool::PanCamera, Tool::Dolly];
+            let next = match tools.iter().position(|x| *x == app.ui.tool) {
+                Some(i) => tools[(i + 1) % tools.len()],
+                None => Tool::Orbit,
+            };
+            app.ui.tool = next;
+            return Ok(json!({"tool": next}));
+        }
+        // Slot shortcuts cycle through the slot's tools.
+        let slot = match t {
+            "shape" => Some(8),
+            "pen" => Some(9),
+            "type" => Some(10),
+            "brush" => Some(11),
+            "rotoBrush" => Some(14),
+            "puppet" => Some(15),
+            _ => None,
+        };
+        if let Some(si) = slot {
+            let tools: Vec<Tool> = match si {
+                11 => vec![Tool::Brush, Tool::Clone, Tool::Eraser],
+                _ => crate::state::Tool::SLOTS[si].to_vec(),
+            };
+            let cur = tools.iter().position(|x| *x == app.ui.tool);
+            let next = match cur {
+                Some(i) => tools[(i + 1) % tools.len()],
+                None => app.ui.slot_tools.get(si).copied().filter(|x| tools.contains(x)).unwrap_or(tools[0]),
+            };
+            app.ui.tool = next;
+            if si < app.ui.slot_tools.len() && si != 11 {
+                app.ui.slot_tools[si] = next;
+            }
+            return Ok(json!({"tool": next}));
+        }
+        let tool = Tool::from_name(t).ok_or_else(|| format!("unknown tool `{t}`"))?;
+        app.ui.tool = tool;
+        return Ok(json!({"tool": tool}));
+    }
+    if let Some(dir) = id.strip_prefix("viewer.nudge.") {
+        return nudge(app, ctx, dir);
+    }
+    if let Some(k) = id.strip_prefix("timeline.reveal.") {
+        if k == "animated" {
+            return run_engine(app, ctx, "anim.reveal", json!({"kind": "keyframes"}));
+        }
+        reveal(app, k, now, false);
+        return Ok(Value::Null);
+    }
+    if let Some(k) = id.strip_prefix("timeline.keyAt.") {
+        let r = run_engine(app, ctx, "keys.toggleTransform", json!({"prop": k}))?;
+        reveal_keyed(app, &r, k);
+        return Ok(r);
+    }
+    if let Some(k) = id.strip_prefix("timeline.revealAdd.") {
+        reveal(app, k, now, true);
+        return Ok(json!({"revealed": app.ui.timeline.reveal}));
+    }
+    // U reveals keyframed properties; UU (pressed twice quickly) all modified properties; U
+    // again later hides them.
+    if id == "anim.reveal" && params.get("kind").and_then(Value::as_str) == Some("keyframes") {
+        let last = app.last_reveal.take();
+        app.last_reveal = Some(("keyframes".into(), now));
+        match last {
+            Some((k, t)) if k == "keyframes" && now - t < 0.6 => {
+                return run_engine(app, ctx, "anim.reveal", json!({"kind": "modified"}));
+            }
+            Some((k, _)) if k == "keyframes" && app.ui.timeline.reveal == ["props"] => {
+                let targets = reveal_targets(app);
+                app.ui.timeline.apply_reveal(&targets, vec![]);
+                return Ok(json!({"revealed": 0}));
+            }
+            _ => {}
+        }
+    }
+    // A UI-only command (not in the engine's menus), so `frontend` gets it from here.
+    if id == "window.maximizeApp" {
+        return frontend(app, ctx, id, params);
+    }
+    // Docking: {panel, anchor, zone: center|left|right|top|bottom}, {panel, rect?}, {panel?}.
+    if let Some(op) = id.strip_prefix("window.").filter(|o| matches!(*o, "maximizePanel" | "dockPanel" | "floatPanel" | "closePanel")) {
+        let panel_of = |k: &str| params.get(k).and_then(Value::as_str).map(|s| PanelKind::from_name(s).ok_or(format!("unknown panel `{s}`")));
+        match op {
+            "maximizePanel" => {
+                let p = match panel_of("panel") {
+                    Some(p) => p?,
+                    None => app.panel_at(ctx.pointer_hover_pos()),
+                };
+                app.toggle_maximize(p);
+                return Ok(json!({"maximized": app.ui.maximized}));
+            }
+            "closePanel" => {
+                let p = panel_of("panel").ok_or("closePanel: need `panel`")??;
+                if app.ui.dock.is_open(p) {
+                    app.apply_dock(craft_ui::docking::Action::Close { panel: p })?;
+                }
+                return Ok(Value::Null);
+            }
+            "floatPanel" => {
+                let p = panel_of("panel").ok_or("floatPanel: need `panel`")??;
+                let r = match params.get("rect") {
+                    Some(value) => serde_json::from_value::<[f32; 4]>(value.clone()).map_err(|_| "rect must contain four finite numbers")?,
+                    None => crate::dock_ui::default_float_rect(ctx.content_rect()),
+                };
+                app.apply_dock(craft_ui::docking::Action::Float { panel: p, rect: r }).map_err(|e| format!("can't undock {}: {e}", p.title()))?;
+                return Ok(Value::Null);
+            }
+            _ => {
+                // craft-ui's `window.panel.dock`: zones center/tab, left/right/top/bottom (a split
+                // beside the anchor), above/below; without an anchor a side zone docks along that
+                // edge of the whole workspace.
+                let p = panel_of("panel").ok_or("dockPanel: need `panel`")??;
+                let mut command = json!({"command": "window.panel.dock", "panel": p});
+                if let Some(anchor) = panel_of("anchor") {
+                    command["anchor"] = json!(anchor?);
+                    command["zone"] = json!("center");
+                }
+                if let Some(zone) = params.get("zone") {
+                    let zone = zone.as_str().ok_or("zone: center|tab|left|right|top|bottom|above|below")?.to_ascii_lowercase();
+                    if command.get("anchor").is_some() || zone != "center" {
+                        command["zone"] = json!(zone);
+                    }
+                }
+                if let Some(before) = panel_of("before") {
+                    command["before"] = json!(before?);
+                }
+                let command: craft_ui::docking::DockCommand<PanelKind> =
+                    serde_json::from_value(command).map_err(|e| format!("dockPanel: zone: center|tab|left|right|top|bottom|above|below ({e})"))?;
+                app.run_dock_command(ctx, command).map_err(|e| format!("can't dock {}: {e}", p.title()))?;
+                app.show_panel(p);
+                return Ok(Value::Null);
+            }
+        }
+    }
+    if id == "markers.dialog" {
+        // The Composition/Layer Marker dialog (double-click a marker): {layer?, index}.
+        let index = params.get("index").and_then(Value::as_u64).ok_or("markers.dialog: need `index`")? as usize;
+        let layer = params.get("layer").and_then(Value::as_u64);
+        crate::panels::markers_ui::open_dialog(app, crate::panels::markers_ui::MarkerRef { layer, index })?;
+        return Ok(json!({"dialog": id}));
+    }
+
+    if id == "view.theme.toggle" {
+        app.cycle_appearance(ctx);
+        return Ok(json!({"appearanceMode": app.session.prefs.appearance.appearance_mode}));
+    }
+    if let Some(th) = id.strip_prefix("view.theme.") {
+        let k = crate::theme::ThemeKind::from_name(th).ok_or("unknown theme")?;
+        app.set_theme(ctx, k);
+        return Ok(Value::Null);
+    }
+    let timing = |app: &mut EffectcraftApp, op: &str| app.session.execute("layer.timing", json!({"op": op})).map_err(|e| e.to_string());
+    match id {
+        "playback.ramPreview" => {
+            app.toggle_play_with(now, effectcraft_engine::preview::PreviewShortcut::Numpad0);
+            return Ok(json!({"playing": app.playback.playing}));
+        }
+        "playback.preview.shiftSpacebar" | "playback.preview.shiftNumpad0" | "playback.preview.altNumpad0" => {
+            let sc = effectcraft_engine::preview::PreviewShortcut::parse(id.trim_start_matches("playback.preview.")).ok_or("unknown preview shortcut")?;
+            app.toggle_play_with(now, sc);
+            return Ok(json!({"playing": app.playback.playing}));
+        }
+        "playback.stop" => {
+            app.stop();
+            return Ok(Value::Null);
+        }
+        // The focused Layer panel has its own magnification; otherwise the Composition viewer.
+        "view.fit" if app.ui.focused == PanelKind::Layer => {
+            app.ui.layer_zoom = None;
+            app.ui.layer_pan = [0.0, 0.0];
+            return Ok(Value::Null);
+        }
+        "view.fit" => {
+            app.ui.viewer.zoom = None;
+            app.ui.viewer.fit_up_to_100 = false;
+            app.ui.viewer.pan = [0.0, 0.0];
+            return Ok(Value::Null);
+        }
+        "timeline.scrollToTime" => app.ui.timeline.scroll_to = Some(crate::state::ScrollTo::Time),
+        "timeline.scrollToLayer" => app.ui.timeline.scroll_to = Some(crate::state::ScrollTo::Layer),
+        "timeline.parentColumn" => {
+            let on = !crate::panels::timeline::column_visible(&app.ui.timeline, "parent");
+            crate::panels::timeline::set_column(&mut app.ui.timeline, "parent", on)?;
+            return Ok(json!({"parent": on}));
+        }
+        "view.fitUpTo100" => {
+            app.ui.viewer.zoom = None;
+            app.ui.viewer.fit_up_to_100 = true;
+            app.ui.viewer.pan = [0.0, 0.0];
+            return Ok(Value::Null);
+        }
+        // Shift+, / Shift+.: the previous / next open composition (the viewer's tabs).
+        "view.nextItem" | "view.previousItem" => {
+            let open = app.session.state.open_comps.clone();
+            let Some(i) = app.session.state.active_comp.and_then(|c| open.iter().position(|o| *o == c)) else { return Ok(Value::Null) };
+            let step = if id == "view.nextItem" { 1 } else { open.len().saturating_sub(1) };
+            let Some(next) = open.get((i + step) % open.len().max(1)).copied().filter(|n| Some(*n) != app.session.state.active_comp) else {
+                return Ok(Value::Null);
+            };
+            return run_engine(app, ctx, "comp.open", json!({"comp": next.0}));
+        }
+        // \\: between the Composition viewer and the Timeline.
+        "window.toggleCompTimeline" => {
+            let to = if app.ui.focused == PanelKind::Timeline { crate::panels::viewers::active_panel(app) } else { PanelKind::Timeline };
+            app.show_panel(to);
+            return Ok(json!({"focused": to.id()}));
+        }
+        // Alt+Shift+, / Alt+Shift+.: the previous / next tab of the focused panel's group.
+        "window.nextPanel" | "window.previousPanel" => {
+            let focused = app.ui.focused;
+            let group = app.ui.dock.group_of(focused);
+            let Some(i) = group.iter().position(|p| *p == focused) else { return Ok(Value::Null) };
+            let step = if id == "window.nextPanel" { 1 } else { group.len().saturating_sub(1) };
+            if let Some(next) = group.get((i + step) % group.len().max(1)).copied() {
+                app.show_panel(next);
+            }
+            return Ok(json!({"focused": app.ui.focused.id()}));
+        }
+        // Ctrl+Shift+W: with a viewer or the Timeline active, every open composition closes;
+        // any other panel closes itself.
+        "window.closeAll" => {
+            let focused = app.ui.focused;
+            if matches!(focused, PanelKind::Composition | PanelKind::Timeline | PanelKind::Viewer(_)) {
+                for c in app.session.state.open_comps.clone() {
+                    run_engine(app, ctx, "comp.close", json!({"comp": c.0}))?;
+                }
+            } else {
+                app.close_panel(focused);
+            }
+            return Ok(Value::Null);
+        }
+        "view.actualSize" if app.ui.focused == PanelKind::Layer => {
+            app.ui.layer_zoom = Some(1.0 / ctx.pixels_per_point());
+            app.ui.layer_pan = [0.0, 0.0];
+            return Ok(Value::Null);
+        }
+        "view.actualSize" => {
+            app.ui.viewer.zoom = Some(1.0 / ctx.pixels_per_point());
+            app.ui.viewer.pan = [0.0, 0.0];
+            return Ok(Value::Null);
+        }
+        "view.safeMargins" => app.ui.viewer.safe_margins = !app.ui.viewer.safe_margins,
+        "view.transparencyGrid" => app.ui.viewer.transparency_grid = !app.ui.viewer.transparency_grid,
+        "view.fastPreviews" => {
+            // With a mode: Fast Previews ▸ Off / Adaptive Resolution / Draft / Fast Draft /
+            // Wireframe; without: toggle Draft quality (Settings ▸ Previews).
+            if params.get("mode").is_some() {
+                return run_engine(app, ctx, "view.fastPreviewMode", params);
+            }
+            let on = !app.ui.viewer.fast_preview;
+            app.set_pref("previews.fastPreviews", json!(on))?;
+            app.ui.viewer.fast_preview = on;
+        }
+        "timeline.zoomIn" | "timeline.zoomOut" => {
+            let k = if id == "timeline.zoomIn" { crate::panels::timeline::ZOOM_STEP } else { 1.0 / crate::panels::timeline::ZOOM_STEP };
+            crate::panels::timeline::zoom(app, ctx, k);
+            return Ok(Value::Null);
+        }
+        "timeline.zoomFit" => crate::panels::timeline::toggle_fit_zoom(app, ctx),
+        "timeline.zoomFrameToggle" => crate::panels::timeline::toggle_frame_zoom(app, ctx),
+        "timeline.column" => {
+            let col = params.get("column").and_then(Value::as_str).ok_or("timeline.column: need `column`")?;
+            let on = params.get("visible").and_then(Value::as_bool).unwrap_or(!crate::panels::timeline::column_visible(&app.ui.timeline, col));
+            crate::panels::timeline::set_column(&mut app.ui.timeline, col, on)?;
+            let shown: Vec<&str> =
+                crate::panels::timeline::COLUMNS.iter().map(|c| c.0).filter(|c| crate::panels::timeline::column_visible(&app.ui.timeline, c)).collect();
+            return Ok(json!({"columns": shown}));
+        }
+        "timeline.sourceName" => {
+            let tl = &mut app.ui.timeline;
+            tl.source_name = params.get("value").and_then(Value::as_bool).unwrap_or(!tl.source_name);
+            return Ok(json!({"sourceName": tl.source_name}));
+        }
+        "flowchart.options" | "flowchart.graph" => return crate::panels::flowchart::command(app, id, &params),
+        "timeline.search" => {
+            app.ui.timeline.search = params.get("query").and_then(Value::as_str).unwrap_or_default().to_string();
+            app.show_panel(PanelKind::Timeline);
+        }
+        "timeline.graphEditor" => app.ui.timeline.graph_editor = !app.ui.timeline.graph_editor,
+        "timeline.switchesModes" => app.ui.timeline.show_modes = !app.ui.timeline.show_modes,
+        "timeline.collapseAll" => {
+            app.ui.timeline.open_layers.clear();
+            app.ui.timeline.open_groups.clear();
+            app.ui.timeline.reveal.clear();
+            app.ui.timeline.layer_reveal.clear();
+        }
+        // Ctrl+`: twirl the selected layers open (all closed ones) or closed (all open). From a
+        // reveal shortcut's view it opens their full property trees.
+        "timeline.twirlSelected" => {
+            let sel: Vec<u64> = app.session.state.selected_layers.iter().map(|l| l.0).collect();
+            let tl = &mut app.ui.timeline;
+            let revealing = sel.iter().any(|l| tl.layer_reveal.contains_key(l));
+            tl.reveal.clear();
+            for l in &sel {
+                tl.layer_reveal.remove(l);
+            }
+            if !revealing && sel.iter().all(|l| tl.open_layers.contains(l)) {
+                for l in &sel {
+                    tl.open_layers.remove(l);
+                }
+            } else {
+                tl.open_layers.extend(sel);
+            }
+        }
+        "timeline.workAreaBegin" => return app.session.execute("comp.workArea", json!({"set": "begin"})).map_err(|e| e.to_string()),
+        "timeline.workAreaEnd" => return app.session.execute("comp.workArea", json!({"set": "end"})).map_err(|e| e.to_string()),
+        "timeline.moveInToTime" => return timing(app, "moveInToTime"),
+        "timeline.moveOutToTime" => return timing(app, "moveOutToTime"),
+        "timeline.trimInToTime" => return timing(app, "trimInToTime"),
+        "timeline.trimOutToTime" => return timing(app, "trimOutToTime"),
+        "app.home" => app.ui.start_screen = !app.ui.start_screen,
+        "app.newComp" | "comp.new" if no_params(&params) => crate::panels::dialogs::open_new_comp(app),
+        "app.compSettings" | "comp.settings" if no_params(&params) => crate::panels::dialogs::open_comp_settings(app)?,
+        "app.compSettings" | "comp.settings" if only_comp(&params).is_some() => {
+            crate::panels::dialogs::open_comp_settings_for(app, only_comp(&params).ok_or("missing `comp`")?)?
+        }
+        "app.solidSettings" | "layer.newSolid" if no_params(&params) => crate::panels::dialogs::open_new_solid(app)?,
+        "keys.velocity" if no_params(&params) => crate::panels::key_dialogs::open_velocity(app)?,
+        "keys.interpolation" if no_params(&params) => crate::panels::key_dialogs::open_interpolation(app)?,
+        "layer.timeStretch" if no_params(&params) => crate::panels::key_dialogs::open_time_stretch(app)?,
+        _ => {
+            if id == "renderQueue.render" && params.get("wait").is_none() {
+                // The UI renders in the background; the panel shows progress.
+                let mut p = params.clone();
+                if let Some(m) = p.as_object_mut() {
+                    m.insert("wait".into(), json!(false));
+                } else {
+                    p = json!({"wait": false});
+                }
+                app.show_panel(PanelKind::RenderQueue);
+                return app.session.execute(id, p).map_err(|e| e.to_string());
+            }
+            if id == "renderQueue.add" {
+                let r = app.session.execute(id, params).map_err(|e| e.to_string());
+                match &r {
+                    Ok(_) => app.show_panel(PanelKind::RenderQueue),
+                    Err(e) => app.ui.status = e.clone(),
+                }
+                return r;
+            }
+            if let Some(r) = file_dialog(app, id, &params) {
+                return r;
+            }
+            if id == "layer.precompose" && params.get("name").is_none() {
+                crate::panels::precomp::open(app, &params)?;
+                return Ok(json!({"dialog": id}));
+            }
+            if crate::panels::dialogs::open_form(app, id, &params) {
+                return Ok(json!({"dialog": id}));
+            }
+            if id == "renderQueue.render" && params.get("wait").is_none() {
+                // The UI renders in the background; the panel shows progress.
+                let mut p = params.clone();
+                if let Some(m) = p.as_object_mut() {
+                    m.insert("wait".into(), json!(false));
+                } else {
+                    p = json!({"wait": false});
+                }
+                app.show_panel(PanelKind::RenderQueue);
+                return app.session.execute(id, p).map_err(|e| e.to_string());
+            }
+            if id == "renderQueue.add" {
+                let r = app.session.execute(id, params).map_err(|e| e.to_string());
+                match &r {
+                    Ok(_) => app.show_panel(PanelKind::RenderQueue),
+                    Err(e) => app.ui.status = e.clone(),
+                }
+                return r;
+            }
+            // An effect added to a layer (Effect menu, Last Effect, dropped on a layer) brings
+            // up Effect Controls on that layer, as in After Effects.
+            if matches!(id, "effect.apply" | "effect.applyLast") {
+                let r = run_engine(app, ctx, id, params.clone());
+                if let Ok(applied) = &r {
+                    crate::panels::effect_controls::reveal_applied(app, &params);
+                    crate::panels::effect_controls::choose_files_after_apply(app, applied);
+                }
+                return r;
+            }
+            // Enabling time remapping twirls its layers open on Time Remap and its two keys.
+            if id == "layer.enableTimeRemap" {
+                let r = run_engine(app, ctx, id, params.clone());
+                if r.as_ref().is_ok_and(|on| on.as_bool() == Some(true)) {
+                    reveal_time_remap(app, &params);
+                }
+                return r;
+            }
+            if id == "layer.rename" && params.get("name").is_none() {
+                crate::panels::timeline::begin_rename(app, ctx);
+                return Ok(Value::Null);
+            }
+            return run_engine(app, ctx, id, params);
+        }
+    }
+    Ok(Value::Null)
+}
diff --git a/crates/ui-egui/src/menus/shortcuts.rs b/crates/ui-egui/src/menus/shortcuts.rs
new file mode 100644
index 000000000..b9990786c
--- /dev/null
+++ b/crates/ui-egui/src/menus/shortcuts.rs
@@ -0,0 +1,418 @@
+use super::frontend::run_engine;
+use super::invoke::invoke;
+use super::{EffectcraftApp, PanelKind, Value, json};
+
+/// Shortcut text in this OS's notation (`⇧⌘K` on macOS, `Ctrl+Shift+K` elsewhere).
+pub fn shortcut_text(s: &str) -> String {
+    if cfg!(target_os = "macos") {
+        let mut out = String::new();
+        let parts: Vec<&str> = match s.strip_suffix("++") {
+            Some(head) => vec![head, "+"],
+            None => s.split('+').collect(),
+        };
+        let (mods, key) = parts.split_at(parts.len().saturating_sub(1));
+        for m in mods {
+            out.push_str(match *m {
+                "Ctrl" => "⌃",
+                "Alt" => "⌥",
+                "Shift" => "⇧",
+                "Cmd" => "⌘",
+                x => x,
+            });
+        }
+        out.push_str(match key.first().copied().unwrap_or("") {
+            "Space" => "Space",
+            "Escape" => "Esc",
+            "Home" => "↖",
+            k => k,
+        });
+        out
+    } else {
+        s.replace("Cmd", "Ctrl")
+    }
+}
+
+/// Parse "Cmd+Shift+K" into modifiers + key.
+pub fn parse_shortcut(s: &str) -> Option<(egui::Modifiers, egui::Key)> {
+    let mut m = egui::Modifiers::NONE;
+    let mut key = None;
+    // The plus key itself is written `+` or `Cmd++`.
+    let (head, plus) = match s.strip_suffix("++") {
+        Some(h) => (h, true),
+        None if s == "+" => ("", true),
+        None => (s, false),
+    };
+    let mut parts: Vec<&str> = if head.is_empty() { vec![] } else { head.split('+').collect() };
+    if plus {
+        parts.push("+");
+    }
+    for p in parts {
+        match p {
+            "Cmd" => {
+                m.command = true;
+                m.mac_cmd = cfg!(target_os = "macos");
+                if !cfg!(target_os = "macos") {
+                    m.ctrl = true;
+                }
+            }
+            "Physical" => {}
+            "Shift" => m.shift = true,
+            "Alt" => m.alt = true,
+            "Ctrl" => m.ctrl = true,
+            k => {
+                key = match k {
+                    ";" => Some(egui::Key::Semicolon),
+                    "'" => Some(egui::Key::Quote),
+                    "," => Some(egui::Key::Comma),
+                    "." => Some(egui::Key::Period),
+                    "/" => Some(egui::Key::Slash),
+                    "\\" => Some(egui::Key::Backslash),
+                    "=" => Some(egui::Key::Equals),
+                    "-" => Some(egui::Key::Minus),
+                    "`" => Some(egui::Key::Backtick),
+                    "[" => Some(egui::Key::OpenBracket),
+                    "]" => Some(egui::Key::CloseBracket),
+                    "Num0" => Some(egui::Key::Num0),
+                    "Num*" => None,
+                    _ => egui::Key::from_name(k),
+                }
+            }
+        }
+    }
+    key.map(|k| (m, k))
+}
+
+/// The key some keyboards report for a shifted punctuation key (`Shift+=` arrives as `+`).
+fn shifted_alias(k: egui::Key) -> Option<egui::Key> {
+    use egui::Key::*;
+    Some(match k {
+        Equals => Plus,
+        Semicolon => Colon,
+        OpenBracket => OpenCurlyBracket,
+        CloseBracket => CloseCurlyBracket,
+        Slash => Questionmark,
+        Backslash => Pipe,
+        _ => return None,
+    })
+}
+
+/// A key binding: modifiers, key, command id and bound params.
+pub type Binding = (egui::Modifiers, egui::Key, String, Value);
+
+/// All bindings of the active keyboard shortcut preset, most modifiers first.
+pub fn bindings(session: &effectcraft_engine::Session) -> Vec<Binding> {
+    let mut v: Vec<Binding> = Vec::new();
+    for (sc, b) in session.shortcuts().bindings() {
+        if sc.starts_with("Physical+") {
+            continue;
+        }
+        // Off macOS `Cmd` is Ctrl, so a custom Ctrl+Cmd shortcut would
+        // steal the plain Cmd one: such macOS-only shortcuts aren't bound there.
+        if !cfg!(target_os = "macos") && sc.split('+').any(|p| p == "Ctrl") && sc.split('+').any(|p| p == "Cmd") {
+            continue;
+        }
+        if let Some((m, k)) = parse_shortcut(sc) {
+            if m.shift
+                && let Some(alias) = shifted_alias(k)
+            {
+                v.push((m, alias, b.command.clone(), b.params.clone()));
+            }
+            v.push((m, k, b.command.clone(), b.params.clone()));
+        }
+    }
+    v.sort_by_key(|(m, ..)| std::cmp::Reverse(m.command as u8 + m.shift as u8 + m.alt as u8 + m.ctrl as u8));
+    v
+}
+
+fn mods_match(want: egui::Modifiers, got: egui::Modifiers) -> bool {
+    want.command == got.command && want.shift == got.shift && want.alt == got.alt && (want.ctrl == got.ctrl || got.command && cfg!(not(target_os = "macos")))
+}
+
+/// Whether the `key`+`mods` chord is the current binding of `command` in the active preset
+/// (so callers that must match a shortcut themselves — like the viewer's text editor, which
+/// holds the keyboard while the shortcut dispatcher is skipped — follow rebinds).
+/// `Physical+`-only bindings never match here, exactly as for the app-wide dispatcher.
+pub fn chord_matches(session: &effectcraft_engine::Session, command: &str, key: egui::Key, mods: egui::Modifiers) -> bool {
+    bindings(session).into_iter().any(|(m, k, id, _)| id == command && k == key && mods_match(m, mods))
+}
+
+/// Whether a Deselect All chord matched by [`chord_matches`] may run while a text editor holds
+/// the keyboard. Chords carrying Cmd/Ctrl/Alt are command chords (the editor treats them as
+/// such for undo and the rest), and function keys never type, so those forward from the editor;
+/// a chord that could instead produce a character — a bare or Shift-only letter, digit or
+/// punctuation key, as from a pathological bare-letter rebinding — stays with the editor so
+/// typing keeps working, the same invariant the app-wide dispatcher honors by skipping
+/// focused text fields.
+pub fn forwardable_during_text_edit(mods: egui::Modifiers, key: egui::Key) -> bool {
+    mods.command || mods.ctrl || mods.alt || (egui::Key::F1..=egui::Key::F35).contains(&key)
+}
+
+/// Set (egui temp data) from a plain Spacebar press until its release while a tap would still
+/// run the Spacebar shortcut.
+/// The system clipboard's text of this frame's paste event, for the Edit ▸ Paste it runs.
+pub(super) fn system_paste_id() -> egui::Id {
+    egui::Id::unique("menus-system-paste")
+}
+
+/// The temp-data id of the flag set by a plain Space press and taken on its release, so a tap
+/// runs the Space shortcut while holding Space stays the Hand tool.
+fn space_tap_id() -> egui::Id {
+    egui::Id::unique("spacebar-tap")
+}
+
+/// The modifiers held when this frame's input began: the state the last pass ended with, if it
+/// ran this (egui keeps only the state after the frame's events). Records this pass's state.
+pub(super) fn modifiers_at_start(ctx: &egui::Context) -> Option<egui::Modifiers> {
+    let id = egui::Id::unique("shortcut-modifiers");
+    let pass = ctx.cumulative_pass_nr();
+    let now = ctx.input(|i| i.modifiers);
+    ctx.data_mut(|d| {
+        let last = d.get_temp::<(u64, egui::Modifiers, Option<egui::Modifiers>)>(id);
+        if let Some((p, _, start)) = last
+            && p == pass
+        {
+            return start;
+        }
+        let start = last.and_then(|(p, m, _)| (p.checked_add(1) == Some(pass)).then_some(m));
+        d.insert_temp(id, (pass, now, start));
+        start
+    })
+}
+
+/// Only Shift held (Shift+Delete, not Ctrl/Alt+Shift+Delete).
+fn only_shift(m: egui::Modifiers) -> bool {
+    m.shift && !m.alt && !m.ctrl && !m.command && !m.mac_cmd
+}
+
+/// Dispatch keyboard shortcuts (skipped while typing in a text field).
+pub fn handle_shortcuts(app: &mut EffectcraftApp, ctx: &egui::Context) {
+    handle_shortcuts_impl(app, ctx, false);
+}
+
+/// Tab can acquire widget focus while the current frame is drawn. Dispatch its application
+/// binding only afterward, and only when no widget owned focus before or after layout.
+pub fn handle_tab_shortcut(app: &mut EffectcraftApp, ctx: &egui::Context) {
+    if ctx.input(|i| i.key_pressed(egui::Key::Tab)) {
+        handle_shortcuts_impl(app, ctx, true);
+    }
+}
+
+/// Escape with a dialog open: close the popup/picker first, else cancel the dialog.
+fn escape_dialog(app: &mut EffectcraftApp, ctx: &egui::Context) {
+    // A popup or colour picker takes Escape first (the picker goes back to its original colour).
+    if crate::panels::shortcut_editor::recording(app)
+        || crate::panels::shortcut_editor::confirming(app)
+        || egui::Popup::is_any_open(ctx)
+        || crate::color_picker::open_recently(ctx)
+    {
+        return;
+    }
+    ctx.input_mut(|i| i.consume_key(egui::Modifiers::NONE, egui::Key::Escape));
+    if app.dialog == Some(crate::Dialog::LayerStyles) {
+        crate::panels::layer_styles_dialog::finish(app, false);
+    } else if app.dialog == Some(crate::Dialog::Info) {
+        crate::panels::forms::close_info(app);
+    } else {
+        if app.dialog == Some(crate::Dialog::Settings)
+            && let Some(p) = app.dialog_state.prefs_snapshot.take()
+        {
+            app.session.prefs = p;
+            app.session.prefs_changed();
+        }
+        if app.dialog == Some(crate::Dialog::UnsavedChanges) {
+            app.dialog_state.unsaved.command = None;
+        }
+        app.dialog = None;
+    }
+}
+
+type KeyEvent = (egui::Key, egui::Modifiers, bool, Option<egui::Key>);
+
+/// The frame's key presses, with clipboard events mapped back to Ctrl+C / X / V.
+fn collect_key_events(ctx: &egui::Context, start: Option<egui::Modifiers>, clipboard: bool, project: bool) -> Vec<KeyEvent> {
+    ctx.input(|i| {
+        // The windowing layer turns Ctrl+C / Ctrl+X / Ctrl+V into clipboard events instead of
+        // key presses: map them back to the keys (with the modifiers held) so Edit ▸ Copy, Cut,
+        // Paste and their variants (Ctrl+Alt+C…) run. Clipboard events carry no modifiers and
+        // `i.modifiers` is the state after all of the frame's events, so each is read with the
+        // modifiers where it is in the stream: walk the events from the frame's starting state.
+        // `None` when that isn't known.
+        let changed = i.events.iter().any(|e| matches!(e, egui::Event::ModifiersChanged(_) | egui::Event::WindowFocused(false)));
+        let mut at = if changed { start } else { Some(i.modifiers) };
+        let held = |at: Option<egui::Modifiers>| at.filter(|m| m.command).unwrap_or(egui::Modifiers::COMMAND);
+        let mut out = Vec::new();
+        for e in &i.events {
+            match e {
+                egui::Event::ModifiersChanged(m) => at = Some(*m),
+                // egui forgets the modifiers held when the window loses focus.
+                egui::Event::WindowFocused(false) => at = Some(egui::Modifiers::NONE),
+                egui::Event::Key { key, physical_key, pressed: true, modifiers, repeat, .. }
+                    if !*repeat
+                        || matches!(
+                            key,
+                            egui::Key::PageUp | egui::Key::PageDown | egui::Key::ArrowLeft | egui::Key::ArrowRight | egui::Key::ArrowUp | egui::Key::ArrowDown
+                        ) =>
+                {
+                    out.push((*key, *modifiers, true, *physical_key));
+                }
+                egui::Event::Key { key: egui::Key::Space, pressed: false, .. } => out.push((egui::Key::Space, egui::Modifiers::NONE, false, None)),
+                egui::Event::Copy if clipboard => out.push((egui::Key::C, held(at), true, None)),
+                // On Windows, Shift+Delete is the old Cut key and arrives as Cut too. The Project
+                // panel has no clipboard: there a Cut with only Shift held is Shift+Delete (Delete
+                // Project Items Without Confirmation). Never when the modifiers aren't known.
+                egui::Event::Cut if clipboard && project && at.is_some_and(only_shift) => {
+                    out.push((egui::Key::Delete, egui::Modifiers::SHIFT, true, None));
+                }
+                egui::Event::Cut if clipboard => out.push((egui::Key::X, held(at), true, None)),
+                egui::Event::Paste(_) if clipboard => out.push((egui::Key::V, held(at), true, None)),
+                _ => {}
+            }
+        }
+        out
+    })
+}
+
+/// Numpad * (or `*` typed with Shift+8): Add Marker (#275). egui has no key for it, so it
+/// comes as text.
+fn numpad_star_marker(app: &mut EffectcraftApp, ctx: &egui::Context) {
+    if !ctx.input(|i| i.events.iter().any(|e| matches!(e, egui::Event::Text(t) if t == "*"))) {
+        return;
+    }
+    let bound = app.session.shortcuts().bindings().into_iter().find(|(k, _)| *k == "Num*").map(|(_, b)| (b.command.clone(), b.params.clone()));
+    // As in After Effects, it marks the selected layers; only with none selected does it add
+    // a composition marker (#976).
+    let bound =
+        bound.map(
+            |(id, params)| {
+                if id == "comp.addMarker" && !app.session.state.selected_layers.is_empty() { ("layer.addMarker".to_owned(), params) } else { (id, params) }
+            },
+        );
+    if let Some((id, params)) = bound
+        && let Err(e) = invoke(app, ctx, &id, if params.is_null() { json!({}) } else { params })
+    {
+        app.ui.status = e;
+    }
+}
+
+fn handle_shortcuts_impl(app: &mut EffectcraftApp, ctx: &egui::Context, tab_only: bool) {
+    let start = modifiers_at_start(ctx);
+    if !tab_only && app.dialog.is_some() && ctx.input(|i| i.key_pressed(egui::Key::Escape)) {
+        escape_dialog(app, ctx);
+        return;
+    }
+    // A mouse button down while Spacebar is held belongs to the Hand tool: its release won't
+    // preview.
+    if ctx.input(|i| i.pointer.any_down()) || ctx.egui_wants_keyboard_input() {
+        ctx.data_mut(|d| d.remove::<bool>(space_tap_id()));
+    }
+    // While a menu or popup list is open, keys go to it, not to the app (Space must not start a
+    // preview behind the menu, #279).
+    if ctx.egui_wants_keyboard_input() || crate::widgets::any_menu_open(ctx) {
+        return;
+    }
+    // Text editing in the viewer takes the clipboard events itself.
+    let clipboard = app.session.state.text_edit.is_none();
+    let project = app.ui.focused == PanelKind::Project;
+    // The paste event's text: Edit ▸ Paste pastes SVG markup as a shape layer.
+    let pasted =
+        if clipboard { ctx.input(|i| i.events.iter().rev().find_map(|e| if let egui::Event::Paste(t) = e { Some(t.clone()) } else { None })) } else { None };
+    let mut events = collect_key_events(ctx, start, clipboard, project);
+    events.retain(|(key, _, _, _)| (*key == egui::Key::Tab) == tab_only);
+    if !tab_only && clipboard && app.dialog.is_none() {
+        numpad_star_marker(app, ctx);
+    }
+    if events.is_empty() {
+        return;
+    }
+    let binds = bindings(&app.session);
+    for (key, mods, pressed, physical_key) in events {
+        // Plain Spacebar runs its shortcut (Play Current Preview) on the release: held, it is
+        // the Hand tool (After Effects), and a drag with it must not start or stop playback.
+        if key == egui::Key::Space && (!pressed || !mods.any()) {
+            if pressed {
+                if app.dialog.is_none() {
+                    ctx.data_mut(|d| d.insert_temp(space_tap_id(), true));
+                }
+                continue;
+            }
+            if !ctx.data_mut(|d| d.remove_temp::<bool>(space_tap_id())).unwrap_or(false) {
+                continue;
+            }
+        }
+        // Escape closes dialogs.
+        if key == egui::Key::Escape && app.dialog.is_some() {
+            // Escape while recording a shortcut cancels the recording, not the editor; so does
+            // Escape in its Delete Preset prompt.
+            if crate::panels::shortcut_editor::recording(app) || crate::panels::shortcut_editor::confirming(app) {
+                continue;
+            }
+            if app.dialog == Some(crate::Dialog::Info) {
+                crate::panels::forms::close_info(app);
+                continue;
+            }
+            // Escape in Settings is Cancel: restore the settings from when it opened.
+            if app.dialog == Some(crate::Dialog::Settings)
+                && let Some(p) = app.dialog_state.prefs_snapshot.take()
+            {
+                app.session.prefs = p;
+                app.session.prefs_changed();
+            }
+            app.dialog = None;
+            continue;
+        }
+        if app.dialog.is_some() {
+            continue;
+        }
+        // Enter in the Project panel renames the selected item (handled by the panel).
+        if key == egui::Key::Enter && !mods.any() && app.ui.focused == PanelKind::Project {
+            continue;
+        }
+        // The Project panel has its own selection; a previously selected Timeline layer
+        // must not be deleted while the Project panel has focus.
+        if matches!(key, egui::Key::Delete | egui::Key::Backspace) && !mods.any() {
+            if matches!(app.ui.focused, PanelKind::Composition | PanelKind::Viewer(_)) && !app.session.state.camera_points.is_empty() {
+                if let Err(e) = run_engine(app, ctx, "camera.deletePoints", json!({})) {
+                    app.ui.status = e;
+                }
+                ctx.input_mut(|i| i.consume_key(egui::Modifiers::NONE, key));
+                continue;
+            }
+            // The queue panel consumes the event after its selection state is drawn.
+            if app.ui.focused == PanelKind::RenderQueue {
+                continue;
+            }
+            let _ = invoke(app, ctx, "edit.clear", json!({}));
+            continue;
+        }
+        // Explicit physical bindings distinguish keys that a layout reports with the same
+        // logical name (for example AZERTY's minus and right parenthesis).
+        let physical = physical_key.and_then(|key| {
+            app.session.shortcuts().bindings().into_iter().find_map(|(sc, b)| {
+                let (m, k) = parse_shortcut(sc.strip_prefix("Physical+")?)?;
+                (k == key && mods_match(m, mods)).then(|| (b.command.clone(), b.params.clone()))
+            })
+        });
+        if let Some((id, params)) = physical {
+            if let Err(e) = invoke(app, ctx, &id, if params.is_null() { json!({}) } else { params }) {
+                app.ui.status = e;
+            }
+            continue;
+        }
+        if let Some((_, _, id, params)) = binds.iter().filter(|(m, k, ..)| *k == key && mods_match(*m, mods)).min_by_key(|(_, _, id, params)| {
+            // The focused panel wins over an application command sharing its chord.
+            let key = effectcraft_engine::shortcuts::binding_key(id, params);
+            app.session.shortcuts().find(&key).is_none_or(|b| b.scope != app.ui.focused.id())
+        }) {
+            let (id, params) = (id.clone(), if params.is_null() { json!({}) } else { params.clone() });
+            if id == "edit.paste"
+                && let Some(t) = &pasted
+            {
+                ctx.data_mut(|d| d.insert_temp(system_paste_id(), t.clone()));
+            }
+            if let Err(e) = invoke(app, ctx, &id, params) {
+                app.ui.status = e;
+            }
+            ctx.data_mut(|d| d.remove_temp::<String>(system_paste_id()));
+        }
+    }
+}
diff --git a/crates/ui-egui/src/menus/tests.rs b/crates/ui-egui/src/menus/tests.rs
new file mode 100644
index 000000000..ed2fcf6ca
--- /dev/null
+++ b/crates/ui-egui/src/menus/tests.rs
@@ -0,0 +1,425 @@
+use super::*;
+
+/// #882: at 125 % / 150 % display scaling Zoom In reaches 100 % (one comp pixel per screen
+/// pixel), not 100 % in points (125 % / 150 % on screen).
+#[test]
+fn zoom_steps_land_on_whole_screen_magnifications() {
+    for ppp in [1.0f32, 1.25, 1.5, 2.0] {
+        let at_100 = zoom_step(0.7 / ppp, ppp, true);
+        assert!((at_100 * ppp - 1.0).abs() < 1e-6, "ppp {ppp}: {}", at_100 * ppp);
+        assert!((zoom_step(at_100, ppp, true) * ppp - 1.5).abs() < 1e-6);
+        assert!((zoom_step(at_100, ppp, false) * ppp - 0.66).abs() < 1e-6);
+    }
+    assert!(zoom_step(1.0, 0.0, true).is_finite());
+}
+
+#[test]
+fn shortcut_passes_share_frame_start_modifiers() {
+    let ctx = egui::Context::default();
+    let mut starts = Vec::new();
+    let mut output = ctx.run_ui(egui::RawInput { events: vec![egui::Event::ModifiersChanged(egui::Modifiers::SHIFT)], ..Default::default() }, |ui| {
+        let ctx = ui.ctx();
+        starts.push(modifiers_at_start(ctx));
+        starts.push(modifiers_at_start(ctx));
+    });
+    output.textures_delta.clear();
+    assert_eq!(starts, vec![None, None]);
+    starts.clear();
+    let mut output = ctx.run_ui(egui::RawInput { events: vec![egui::Event::ModifiersChanged(egui::Modifiers::NONE)], ..Default::default() }, |ui| {
+        let ctx = ui.ctx();
+        starts.push(modifiers_at_start(ctx));
+        starts.push(modifiers_at_start(ctx));
+    });
+    output.textures_delta.clear();
+    assert_eq!(starts, vec![Some(egui::Modifiers::SHIFT), Some(egui::Modifiers::SHIFT)]);
+}
+
+#[test]
+fn every_ui_shortcut_parses() {
+    for c in UI_COMMANDS {
+        if let Some(sc) = c.shortcut {
+            assert!(parse_shortcut(sc).is_some() || sc == "Num*", "{sc}");
+        }
+    }
+    for (_, e) in effectcraft_engine::menus::entries() {
+        if let Some(sc) = &e.shortcut {
+            assert!(parse_shortcut(sc).is_some() || sc == "Num*", "{} ({sc})", e.label);
+        }
+    }
+}
+
+#[test]
+fn full_screen_default_is_platform_specific() {
+    let app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    let full_screen = app.session.shortcuts().shortcut_of("view.fullScreen", &Value::Null);
+    if cfg!(target_os = "macos") {
+        assert_eq!(full_screen, Some("Ctrl+Cmd+F"));
+    } else {
+        assert_eq!(full_screen, None);
+        assert_eq!(app.session.shortcuts().shortcut_of("window.maximizeApp", &Value::Null), Some("Cmd+\\"));
+    }
+}
+
+#[test]
+fn ui_and_menu_shortcuts_do_not_collide() {
+    let app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    let mut seen: std::collections::BTreeMap<(String, String), (String, String)> = Default::default();
+    for (m, k, id, params) in bindings(&app.session) {
+        let key = (format!("{m:?}"), format!("{k:?}"));
+        let target = (id.clone(), params.to_string());
+        if let Some(prev) = seen.get(&key) {
+            assert_eq!(prev, &target, "{key:?} bound to {prev:?} and {target:?}");
+        } else {
+            seen.insert(key, target);
+        }
+    }
+}
+
+/// #336: Ctrl+\ (Cmd+\ on macOS) maximizes the application window, and again restores
+/// it, as in After Effects.
+#[test]
+fn ctrl_backslash_maximizes_or_restores_the_window() {
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    let (m, k) = parse_shortcut("Cmd+\\").unwrap();
+    assert!(m.command && k == egui::Key::Backslash, "{m:?} {k:?}");
+    assert!(bindings(&app.session).iter().any(|b| (b.0, b.1) == (m, k) && b.2 == "window.maximizeApp"));
+    let ctx = egui::Context::default();
+    let run = |app: &mut EffectcraftApp, maximized: bool| {
+        let input = egui::RawInput {
+            viewports: std::iter::once((egui::ViewportId::ROOT, egui::ViewportInfo { maximized: Some(maximized), ..Default::default() })).collect(),
+            ..Default::default()
+        };
+        let mut r = Value::Null;
+        let mut out = ctx.run_ui(input, |ui| r = invoke(app, ui.ctx(), "window.maximizeApp", json!({})).unwrap());
+        out.textures_delta.clear();
+        let cmds = out.viewport_output.get(&egui::ViewportId::ROOT).map(|v| v.commands.clone()).unwrap_or_default();
+        (r, cmds)
+    };
+    let (r, cmds) = run(&mut app, false);
+    assert_eq!(r, json!({"maximized": true}));
+    assert!(cmds.contains(&egui::ViewportCommand::Maximized(true)), "{cmds:?}");
+    let (r, cmds) = run(&mut app, true);
+    assert_eq!(r, json!({"maximized": false}));
+    assert!(cmds.contains(&egui::ViewportCommand::Maximized(false)), "{cmds:?}");
+}
+
+/// The default keys of the keyboard-only commands parse and reach them.
+#[test]
+fn keyboard_only_commands_are_bound() {
+    let app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    for (id, keys) in [
+        ("time.workAreaStart", "Shift+Home"),
+        ("time.workAreaEnd", "Shift+End"),
+        ("time.previousInOut", "Cmd+Alt+Shift+ArrowLeft"),
+        ("time.nextInOut", "Cmd+Alt+Shift+ArrowRight"),
+        ("comp.workAreaToSelection", "Cmd+Alt+B"),
+        ("comp.activateRecent", "Shift+Escape"),
+        ("keys.deselectAll", "Shift+F2"),
+        ("keys.deselectAll", "Cmd+Alt+Shift+A"),
+        ("layer.extendSelectionNext", "Cmd+Shift+ArrowDown"),
+        ("layer.moveInToStart", "Alt+Home"),
+        ("layer.moveEarlier", "Alt+PageUp"),
+        ("layer.moveLater10", "Alt+Shift+PageDown"),
+        ("layer.stretchInToTime", "Cmd+Shift+,"),
+        ("layer.stretchOutToTime", "Cmd+Alt+,"),
+        ("layer.mask.selectNext", "Alt+`"),
+        ("layer.mask.selectPrevious", "Alt+Shift+`"),
+        ("layer.castsShadows", "Alt+Shift+C"),
+        ("timeline.scrollToTime", "D"),
+        ("timeline.scrollToLayer", "X"),
+        ("timeline.parentColumn", "Shift+F4"),
+        ("view.fitUpTo100", "Alt+/"),
+        ("view.nextItem", "Shift+."),
+        ("view.previousItem", "Shift+,"),
+        ("window.toggleCompTimeline", "\\"),
+        ("window.nextPanel", "Alt+Shift+."),
+        ("window.previousPanel", "Alt+Shift+,"),
+        ("window.closeAll", "Cmd+Shift+W"),
+        ("tool.camera", "C"),
+    ] {
+        assert!(bindings(&app.session).into_iter().any(|x| x.2 == id && Some((x.0, x.1)) == parse_shortcut(keys)), "{id} on {keys}");
+    }
+}
+
+#[test]
+fn timeline_keys_scroll_and_toggle_the_parent_column() {
+    let ctx = egui::Context::default();
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    let run = |app: &mut EffectcraftApp, id: &str| invoke(app, &ctx, id, json!({})).unwrap();
+    // D and X leave a scroll for the Timeline to do when it is drawn.
+    run(&mut app, "timeline.scrollToTime");
+    assert_eq!(app.ui.timeline.scroll_to, Some(crate::state::ScrollTo::Time));
+    run(&mut app, "timeline.scrollToLayer");
+    assert_eq!(app.ui.timeline.scroll_to, Some(crate::state::ScrollTo::Layer));
+    // Shift+F4 shows and hides the Parent column.
+    let parent = crate::panels::timeline::column_visible(&app.ui.timeline, "parent");
+    run(&mut app, "timeline.parentColumn");
+    assert_eq!(crate::panels::timeline::column_visible(&app.ui.timeline, "parent"), !parent);
+    run(&mut app, "timeline.parentColumn");
+    assert_eq!(crate::panels::timeline::column_visible(&app.ui.timeline, "parent"), parent);
+}
+
+#[test]
+fn viewer_keys_fit_and_step_through_open_comps() {
+    let ctx = egui::Context::default();
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    let run = |app: &mut EffectcraftApp, id: &str| invoke(app, &ctx, id, json!({})).unwrap();
+    let new = |app: &mut EffectcraftApp, name: &str| app.session.execute("comp.new", json!({"name": name, "duration": 4})).unwrap()["comp"].as_u64();
+    let active = |app: &EffectcraftApp| app.session.state.active_comp.map(|c| c.0);
+    // With one composition open there is nothing to step to.
+    let a = new(&mut app, "A");
+    run(&mut app, "view.nextItem");
+    assert_eq!(active(&app), a);
+    // Shift+, / Shift+.: through the open compositions, wrapping.
+    let b = new(&mut app, "B");
+    assert_eq!(active(&app), b);
+    run(&mut app, "view.nextItem");
+    assert_eq!(active(&app), a);
+    run(&mut app, "view.previousItem");
+    assert_eq!(active(&app), b);
+    // Alt+/ fits the viewer without magnifying past 100 %; Shift+/ fits fully again.
+    app.ui.viewer.zoom = Some(3.0);
+    run(&mut app, "view.fitUpTo100");
+    assert!(app.ui.viewer.zoom.is_none() && app.ui.viewer.fit_up_to_100);
+    run(&mut app, "view.fit");
+    assert!(!app.ui.viewer.fit_up_to_100);
+}
+
+#[test]
+fn panel_keys_switch_cycle_and_close() {
+    let ctx = egui::Context::default();
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    let run = |app: &mut EffectcraftApp, id: &str| invoke(app, &ctx, id, json!({})).unwrap();
+    for name in ["A", "B"] {
+        app.session.execute("comp.new", json!({"name": name, "duration": 4})).unwrap();
+    }
+    // \\ switches between the Timeline and the Composition viewer.
+    app.ui.focused = PanelKind::Timeline;
+    run(&mut app, "window.toggleCompTimeline");
+    assert_eq!(app.ui.focused, PanelKind::Composition);
+    run(&mut app, "window.toggleCompTimeline");
+    assert_eq!(app.ui.focused, PanelKind::Timeline);
+    // Alt+Shift+. / Alt+Shift+,: the tabs of the focused panel's group, wrapping.
+    let group = app.ui.dock.group_of(PanelKind::Timeline);
+    assert!(group.len() > 1, "{group:?}");
+    run(&mut app, "window.nextPanel");
+    assert_eq!(app.ui.focused, group[(group.iter().position(|p| *p == PanelKind::Timeline).unwrap() + 1) % group.len()]);
+    run(&mut app, "window.previousPanel");
+    assert_eq!(app.ui.focused, PanelKind::Timeline);
+    // Ctrl+Shift+W with the Timeline active closes every composition.
+    run(&mut app, "window.closeAll");
+    assert!(app.session.state.open_comps.is_empty());
+    // With another panel active it closes that panel.
+    app.show_panel(PanelKind::Project);
+    run(&mut app, "window.closeAll");
+    assert!(!app.ui.dock.is_open(PanelKind::Project));
+}
+
+#[test]
+fn c_cycles_the_camera_tools() {
+    let ctx = egui::Context::default();
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    app.ui.tool = Tool::Selection;
+    let mut seen = vec![];
+    for _ in 0..4 {
+        invoke(&mut app, &ctx, "tool.camera", json!({})).unwrap();
+        seen.push(app.ui.tool);
+    }
+    assert_eq!(seen, [Tool::Orbit, Tool::PanCamera, Tool::Dolly, Tool::Orbit]);
+}
+
+#[test]
+fn dispatch_uses_the_active_custom_preset() {
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    let find = |app: &EffectcraftApp, id: &str| bindings(&app.session).into_iter().filter(|b| b.2 == id).map(|b| (b.0, b.1)).collect::<Vec<_>>();
+    let (m, k) = parse_shortcut("Cmd+Alt+Shift+Y").unwrap();
+    assert!(find(&app, "layer.newNull").contains(&(m, k)));
+    // A UI command rebound in a custom preset.
+    app.session.execute("shortcuts.set", json!({"command": "tool.hand", "keys": "Ctrl+Alt+H"})).unwrap();
+    assert_eq!(app.session.keymaps.active, "Custom");
+    let (m2, k2) = parse_shortcut("Ctrl+Alt+H").unwrap();
+    assert_eq!(find(&app, "tool.hand"), vec![(m2, k2)]);
+    app.session.execute("shortcuts.set", json!({"command": "layer.newNull", "keys": "F6"})).unwrap();
+    assert_eq!(find(&app, "layer.newNull"), vec![(egui::Modifiers::NONE, egui::Key::F6)]);
+    // The menus show the preset's shortcut.
+    let item = menu_items(&app).into_iter().find(|i| i.id == "layer.newNull").unwrap();
+    assert_eq!(item.shortcut.as_deref(), Some("F6"));
+    // Back to the default preset.
+    app.session.execute("shortcuts.preset", json!({"op": "select", "name": effectcraft_engine::shortcuts::DEFAULT_PRESET})).unwrap();
+    assert!(find(&app, "layer.newNull").contains(&(m, k)));
+}
+
+#[test]
+fn renamed_label_shows_in_the_label_menu() {
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    app.set_pref("labels.1.name", json!("Sunflower")).unwrap();
+    let labels: Vec<String> = menu_items(&app).into_iter().filter(|i| i.id == "edit.label").map(|i| i.label).collect();
+    assert!(labels.contains(&"Sunflower".to_string()), "{labels:?}");
+    assert!(!labels.contains(&"Yellow".to_string()));
+}
+
+/// Saving anything but a project asks the save dialog for that file's extension (#293): the
+/// project dialog, filtered to `.ecproj`, made macOS append `.ecproj` (`Frame.png.ecproj`).
+/// Hosts with only the project dialog (the web) still get it, given the file name.
+#[test]
+fn save_dialogs_offer_the_file_extension() {
+    use std::cell::RefCell;
+    use std::rc::Rc;
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    app.session.execute("comp.new", json!({"name": "A", "width": 64, "height": 36, "frameRate": 30, "duration": 1})).unwrap();
+    let ctx = egui::Context::default();
+    let asked: Rc<RefCell<Vec<String>>> = Rc::default();
+    let (a, b) = (asked.clone(), asked.clone());
+    app.hooks.pick_save = Some(Box::new(move |name: &str| {
+        a.borrow_mut().push(format!("project {name}"));
+        None
+    }));
+    app.hooks.pick_save_file = Some(Box::new(move |name: &str, ext: &str| {
+        b.borrow_mut().push(format!("file {name} [{ext}]"));
+        None
+    }));
+    for id in ["comp.saveFrameAs", "render.saveCurrentPreview", "file.exportLottie", "file.saveCopyAsXml", "file.collectFiles", "file.saveAs"] {
+        invoke(&mut app, &ctx, id, json!({})).unwrap();
+    }
+    assert_eq!(
+        *asked.borrow(),
+        [
+            "file Frame.png [png]",
+            "file Preview.mp4 [mp4]",
+            "file Animation.json [json]",
+            "file Untitled Project.ecprojx [ecprojx]",
+            "file Collected Files []",
+            "project Untitled Project.ecproj",
+        ]
+    );
+    // Without the other dialog, the project one names any file.
+    app.hooks.pick_save_file = None;
+    asked.borrow_mut().clear();
+    invoke(&mut app, &ctx, "comp.saveFrameAs", json!({})).unwrap();
+    assert_eq!(*asked.borrow(), ["project Frame.png"]);
+}
+
+/// File ▸ Scripts ▸ Recent Script Files and its key run a script again without a file dialog.
+#[test]
+fn recent_script_files_run_without_a_dialog() {
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    let ctx = egui::Context::default();
+    let dir = std::env::temp_dir().join(format!("ec-recent-script-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let script = dir.join("New Comp.jsonl");
+    std::fs::write(&script, r#"{"command": "comp.new", "params": {"name": "From Script", "width": 64, "height": 36, "frameRate": 30, "duration": 1}}"#)
+        .unwrap();
+    app.session.execute("file.runScript", json!({"path": script.to_string_lossy()})).unwrap();
+    let (m, k, id, params) =
+        bindings(&app.session).into_iter().find(|b| b.2 == "file.runScript" && b.3 == json!({"recent": 0})).expect("the most recent script has a key");
+    assert_eq!((m, k), parse_shortcut("Cmd+Alt+Shift+D").unwrap());
+    assert_eq!(invoke(&mut app, &ctx, &id, params).unwrap()["steps"], 1);
+    assert_eq!(app.session.project.items.values().filter(|i| i.name.starts_with("From Script")).count(), 2);
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+/// #511: with a host's non-blocking dialogs, a command's file dialog opens without running
+/// a nested event loop inside the frame (a drag over the window then aborted the app on
+/// macOS); the command runs on a later frame with the answer, and a cancelled one not at all.
+#[test]
+fn file_dialogs_can_answer_on_a_later_frame() {
+    use std::sync::{Arc, Mutex};
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    app.session.execute("comp.new", json!({"name": "A", "width": 64, "height": 36, "frameRate": 30, "duration": 1})).unwrap();
+    let ctx = egui::Context::default();
+    app.hooks.pick_save = Some(Box::new(|_: &str| panic!("the blocking dialog is not used")));
+    let pending: Arc<Mutex<Vec<(crate::FileDialog, crate::DialogDone)>>> = Arc::default();
+    let queue = pending.clone();
+    app.hooks.file_dialog_async = Some(Box::new(move |dialog, done| queue.lock().unwrap().push((dialog, done))));
+    assert_eq!(invoke(&mut app, &ctx, "file.saveAs", json!({})).unwrap(), json!({"dialog": "file.saveAs"}));
+    let (dialog, done) = pending.lock().unwrap().pop().expect("a dialog was shown");
+    assert_eq!(dialog, crate::FileDialog::Save { default: "Untitled Project.ecproj".into(), ext: "ecproj".into(), project: true });
+    assert!(app.session.path.is_none(), "nothing saved until the dialog answers");
+    let dir = std::env::temp_dir().join(format!("ec-dialog-answer-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("Answered.ecproj");
+    // Answered from another thread, as the host's dialog does.
+    std::thread::spawn(move || done(vec![path.to_string_lossy().to_string()])).join().unwrap();
+    app.run_dialog_answers();
+    assert_eq!(app.session.path.as_deref(), Some(dir.join("Answered.ecproj").to_string_lossy().as_ref()));
+    assert!(dir.join("Answered.ecproj").is_file());
+    // Cancelled: nothing runs.
+    invoke(&mut app, &ctx, "comp.saveFrameAs", json!({})).unwrap();
+    let (dialog, done) = pending.lock().unwrap().pop().expect("a dialog was shown");
+    assert_eq!(dialog, crate::FileDialog::Save { default: "Frame.png".into(), ext: "png".into(), project: false });
+    done(Vec::new());
+    app.run_dialog_answers();
+    assert!(!dir.join("Frame.png").exists());
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+/// While a command's OS file dialog is up, floating panels' OS windows are blocked, as for
+/// a modal dialog; a dialog that ends, answered or not, unblocks them, and Save As opens a
+/// dialog again. A macOS sheet can end without answering (its window went away): once one of
+/// the app's windows has the keyboard again, or keeps it as if no dialog showed, floating
+/// windows are not left blocked.
+#[test]
+fn file_dialogs_block_floating_windows_only_while_up() {
+    use std::sync::{Arc, Mutex};
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    let ctx = egui::Context::default();
+    let pending: Arc<Mutex<Vec<crate::DialogDone>>> = Arc::default();
+    let queue = pending.clone();
+    app.hooks.file_dialog_async = Some(Box::new(move |_dialog, done| queue.lock().unwrap().push(done)));
+    let blocked = |app: &mut EffectcraftApp, focused: bool, time: f64| {
+        let input = egui::RawInput { focused, time: Some(time), ..Default::default() };
+        let mut out = false;
+        ctx.run_ui(input, |ui| out = app.floats_blocked(ui.ctx())).textures_delta.clear();
+        out
+    };
+    assert!(!blocked(&mut app, true, 0.0));
+    // Cancelled.
+    invoke(&mut app, &ctx, "file.saveAs", json!({})).unwrap();
+    assert!(blocked(&mut app, true, 0.1), "blocked while the dialog takes the keyboard");
+    assert!(blocked(&mut app, false, 0.2));
+    let done = pending.lock().unwrap().pop().expect("a dialog was shown");
+    done(Vec::new());
+    app.run_dialog_answers();
+    assert!(!blocked(&mut app, false, 0.3));
+    // Save As asks again; the sheet ends without answering.
+    invoke(&mut app, &ctx, "file.saveAs", json!({})).unwrap();
+    assert_eq!(pending.lock().unwrap().len(), 1, "Save As opens a dialog again");
+    assert!(blocked(&mut app, true, 1.0));
+    assert!(blocked(&mut app, false, 1.1));
+    assert!(blocked(&mut app, false, 9.0), "a dialog may stay up for long");
+    assert!(!blocked(&mut app, true, 9.1), "an app window has the keyboard again");
+    // A dialog that never takes the keyboard.
+    invoke(&mut app, &ctx, "file.saveAs", json!({})).unwrap();
+    assert!(blocked(&mut app, true, 10.0));
+    assert!(blocked(&mut app, true, 11.0));
+    assert!(!blocked(&mut app, true, 12.5));
+    // Answers of dialogs taken for gone arrive late: nothing stays blocked.
+    for done in pending.lock().unwrap().drain(..) {
+        done(Vec::new());
+    }
+    app.run_dialog_answers();
+    assert!(!blocked(&mut app, false, 13.0));
+    invoke(&mut app, &ctx, "file.saveAs", json!({})).unwrap();
+    assert!(blocked(&mut app, false, 13.1), "a later dialog blocks again");
+}
+
+#[test]
+fn tga_is_available_in_import_replace_and_proxy_dialogs() {
+    use std::sync::{Arc, Mutex};
+    let mut app = EffectcraftApp::new(effectcraft_engine::Session::default());
+    let ctx = egui::Context::default();
+    let pending = Arc::new(Mutex::new(Vec::new()));
+    let queue = pending.clone();
+    app.hooks.file_dialog_async = Some(Box::new(move |dialog, _done| queue.lock().unwrap().push(dialog)));
+    for command in ["file.import", "file.importMultiple", "file.replaceFootage", "file.setProxy"] {
+        assert_eq!(invoke(&mut app, &ctx, command, json!({})).unwrap(), json!({"dialog": command}));
+        let crate::FileDialog::Open { exts, .. } = pending.lock().unwrap().pop().unwrap() else { panic!("not an open dialog") };
+        assert!(exts.iter().any(|ext| ext == "tga"), "{command}: {exts:?}");
+    }
+}
+
+#[test]
+fn menu_items_cover_the_tree() {
+    assert_eq!(menus().last(), Some(&"Help"));
+    assert!(effectcraft_engine::menus::entries().len() > 500);
+}
diff --git a/crates/ui-egui/src/native_menu.rs b/crates/ui-egui/src/native_menu.rs
index 9288ec4e1..fac8f0d53 100644
--- a/crates/ui-egui/src/native_menu.rs
+++ b/crates/ui-egui/src/native_menu.rs
@@ -340,6 +340,7 @@ pub fn state_key(app: &EffectcraftApp) -> u64 {
     s.journal.last().map(|j| &j.0).hash(&mut h);
     s.prefs.recent_projects.hash(&mut h);
     (&s.prefs.recent_footage, &s.prefs.recent_presets).hash(&mut h);
+    s.prefs.recent_scripts.hash(&mut h);
     s.history.undo.iter().for_each(|(l, _)| l.hash(&mut h));
     s.state.open_comps.hash(&mut h);
     s.active_comp_id().and_then(|c| s.state.views3d.get(&c)).map(|v| format!("{:?}", v.current)).hash(&mut h);
diff --git a/crates/ui-egui/src/panels/mod.rs b/crates/ui-egui/src/panels.rs
similarity index 100%
rename from crates/ui-egui/src/panels/mod.rs
rename to crates/ui-egui/src/panels.rs
diff --git a/crates/ui-egui/src/panels/anim_tools.rs b/crates/ui-egui/src/panels/anim_tools.rs
index fe4c67895..b07da8567 100644
--- a/crates/ui-egui/src/panels/anim_tools.rs
+++ b/crates/ui-egui/src/panels/anim_tools.rs
@@ -33,9 +33,9 @@ fn choice(app: &mut EffectcraftApp, ui: &mut egui::Ui, r: Rect, auto: &str, opti
 
 /// A drag-to-change number field for an anim-tool setting: `v` clamped to `range`, `speed` points
 /// per pixel, `dec` decimals and a `suffix`; returns the new value, or `v` when it did not change.
-fn number(app: &mut EffectcraftApp, ui: &mut egui::Ui, at: egui::Pos2, auto: &str, v: f64, speed: f64, range: (f64, f64), dec: usize, suffix: &str) -> f64 {
+fn number(app: &mut EffectcraftApp, ui: &mut egui::Ui, at: egui::Pos2, auto: &str, v: f64, spec: widgets::HotSpec) -> f64 {
     let t = app.tokens;
-    let (r, nv, _) = widgets::hot_number_at(ui, at, egui::Id::unique(("animtool-n", auto)), v, speed, range, dec, suffix, &t);
+    let (r, nv, _) = widgets::hot_number_at(ui, at, egui::Id::unique(("animtool-n", auto)), v, &spec, &t);
     app.auto.add(auto, r, &format!("{v}"));
     nv.unwrap_or(v)
 }
@@ -105,10 +105,24 @@ pub fn wiggler(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
     y += ROW + 4.0;
     label(&p, x0, y, "Frequency:", &t);
-    st.wiggle_frequency = number(app, ui, pos2(xv, y), "wiggler.frequency", st.wiggle_frequency, 0.1, (0.1, 100.0), 1, " per second");
+    st.wiggle_frequency = number(
+        app,
+        ui,
+        pos2(xv, y),
+        "wiggler.frequency",
+        st.wiggle_frequency,
+        widgets::HotSpec { speed: 0.1, range: (0.1, 100.0), decimals: 1, suffix: " per second" },
+    );
     y += ROW;
     label(&p, x0, y, "Magnitude:", &t);
-    st.wiggle_magnitude = number(app, ui, pos2(xv, y), "wiggler.magnitude", st.wiggle_magnitude, 0.5, (0.0, 100_000.0), 1, "");
+    st.wiggle_magnitude = number(
+        app,
+        ui,
+        pos2(xv, y),
+        "wiggler.magnitude",
+        st.wiggle_magnitude,
+        widgets::HotSpec { speed: 0.5, range: (0.0, 100_000.0), decimals: 1, suffix: "" },
+    );
     y += ROW + 8.0;
     app.ui.anim_tools = st.clone();
     let b = Rect::from_min_size(pos2(rect.max.x - 92.0, y), vec2(80.0, 24.0));
@@ -149,7 +163,14 @@ pub fn smoother(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     p.text(pos2(xv, y + 9.0), Align2::LEFT_CENTER, txt, Tokens::ui(12.0), t.text);
     y += ROW;
     label(&p, x0, y, "Tolerance:", &t);
-    let tol = number(app, ui, pos2(xv, y), "smoother.tolerance", app.ui.anim_tools.smooth_tolerance, 0.05, (0.0, 10_000.0), 2, "");
+    let tol = number(
+        app,
+        ui,
+        pos2(xv, y),
+        "smoother.tolerance",
+        app.ui.anim_tools.smooth_tolerance,
+        widgets::HotSpec { speed: 0.05, range: (0.0, 10_000.0), decimals: 2, suffix: "" },
+    );
     app.ui.anim_tools.smooth_tolerance = tol;
     y += ROW + 8.0;
     let b = Rect::from_min_size(pos2(rect.max.x - 92.0, y), vec2(80.0, 24.0));
@@ -170,10 +191,24 @@ pub fn motion_sketch(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let mut y = rect.min.y + 10.0;
     let mut st = app.ui.anim_tools.clone();
     label(&p, x0, y, "Capture speed at:", &t);
-    st.sketch_speed = number(app, ui, pos2(xv, y), "motionSketch.captureSpeed", st.sketch_speed, 1.0, (1.0, 10_000.0), 0, " %");
+    st.sketch_speed = number(
+        app,
+        ui,
+        pos2(xv, y),
+        "motionSketch.captureSpeed",
+        st.sketch_speed,
+        widgets::HotSpec { speed: 1.0, range: (1.0, 10_000.0), decimals: 0, suffix: " %" },
+    );
     y += ROW;
     label(&p, x0, y, "Smoothing:", &t);
-    st.sketch_smoothing = number(app, ui, pos2(xv, y), "motionSketch.smoothing", st.sketch_smoothing, 0.1, (0.0, 100.0), 1, "");
+    st.sketch_smoothing = number(
+        app,
+        ui,
+        pos2(xv, y),
+        "motionSketch.smoothing",
+        st.sketch_smoothing,
+        widgets::HotSpec { speed: 0.1, range: (0.0, 100.0), decimals: 1, suffix: "" },
+    );
     y += ROW + 2.0;
     p.text(pos2(x0, y + 8.0), Align2::LEFT_CENTER, tr("Show:"), Tokens::ui(12.0), t.text_dim);
     y += ROW - 6.0;
@@ -328,7 +363,14 @@ pub fn mask_interpolation(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rec
         changes.insert("keyframeRate".into(), if i == 0 { json!("auto") } else { json!(fps) });
     }
     if let Some(r) = o.keyframe_rate {
-        let nr = number(app, ui, pos2(xv + 78.0, y), "maskInterp.rate", r, 0.5, (0.1, 1000.0), 1, " per second");
+        let nr = number(
+            app,
+            ui,
+            pos2(xv + 78.0, y),
+            "maskInterp.rate",
+            r,
+            widgets::HotSpec { speed: 0.5, range: (0.1, 1000.0), decimals: 1, suffix: " per second" },
+        );
         if (nr - r).abs() > 1e-9 {
             changes.insert("keyframeRate".into(), json!(nr));
         }
@@ -346,13 +388,20 @@ pub fn mask_interpolation(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rec
     check(app, y, "linearVertexPaths", "Use \"Linear\" Vertex Paths", o.linear_vertex_paths);
     y += ROW;
     label(&p, x0, y, "Bending Resistance:", &t);
-    let br = number(app, ui, pos2(xv, y), "maskInterp.bendingResistance", o.bending_resistance, 0.5, (0.0, 100.0), 0, "");
+    let br = number(
+        app,
+        ui,
+        pos2(xv, y),
+        "maskInterp.bendingResistance",
+        o.bending_resistance,
+        widgets::HotSpec { speed: 0.5, range: (0.0, 100.0), decimals: 0, suffix: "" },
+    );
     if (br - o.bending_resistance).abs() > 1e-9 {
         changes.insert("bendingResistance".into(), json!(br));
     }
     y += ROW;
     label(&p, x0, y, "Quality:", &t);
-    let q = number(app, ui, pos2(xv, y), "maskInterp.quality", o.quality, 0.5, (0.0, 100.0), 0, "");
+    let q = number(app, ui, pos2(xv, y), "maskInterp.quality", o.quality, widgets::HotSpec { speed: 0.5, range: (0.0, 100.0), decimals: 0, suffix: "" });
     if (q - o.quality).abs() > 1e-9 {
         changes.insert("quality".into(), json!(q));
     }
@@ -363,7 +412,8 @@ pub fn mask_interpolation(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rec
     }
     y += ROW;
     if let Some(v) = o.add_vertices {
-        let nv = number(app, ui, pos2(x0 + 22.0, y), "maskInterp.addVertices", v, 0.2, (0.1, 2000.0), 1, "");
+        let nv =
+            number(app, ui, pos2(x0 + 22.0, y), "maskInterp.addVertices", v, widgets::HotSpec { speed: 0.2, range: (0.1, 2000.0), decimals: 1, suffix: "" });
         if (nv - v).abs() > 1e-9 {
             changes.insert("addVertices".into(), json!(nv));
         }
diff --git a/crates/ui-egui/src/panels/comp_settings.rs b/crates/ui-egui/src/panels/comp_settings.rs
index 1dc6fad37..3f7cda26d 100644
--- a/crates/ui-egui/src/panels/comp_settings.rs
+++ b/crates/ui-egui/src/panels/comp_settings.rs
@@ -286,7 +286,7 @@ pub fn show(
                     .or_else(|| PRESETS.iter().find(|(_, w, h, par, f)| matches(d, *w, *h, *par, *f)).map(|p| p.0))
                     .unwrap_or("Custom");
                 ui.horizontal(|ui| {
-                    let r = egui::ComboBox::from_id_salt("comp-preset").width(300.0).selected_text(current).show_ui(ui, |ui| {
+                    let r = craft_ui::ComboBox::from_id_salt("comp-preset").width(300.0).selected_text(current).show_ui(ui, |ui| {
                         // Your own presets first, then the built-in ones.
                         for q in custom {
                             if ui.selectable_label(q.name == current, &q.name).clicked() {
@@ -350,7 +350,7 @@ pub fn show(
                         .find(|(_, v)| (v - d.pixel_aspect).abs() < 1e-3)
                         .map(|p| p.0.to_string())
                         .unwrap_or_else(|| format!("{:.2}", d.pixel_aspect));
-                    let r = egui::ComboBox::from_id_salt("comp-par").width(220.0).selected_text(cur).show_ui(ui, |ui| {
+                    let r = craft_ui::ComboBox::from_id_salt("comp-par").width(220.0).selected_text(cur).show_ui(ui, |ui| {
                         for (name, v) in PIXEL_ASPECTS {
                             if ui.selectable_label((v - d.pixel_aspect).abs() < 1e-3, *name).clicked() {
                                 d.pixel_aspect = *v;
@@ -369,7 +369,7 @@ pub fn show(
                     // Any rate can be typed; the list holds the common ones.
                     let r = ui.add(crate::widgets::drag_value(egui::DragValue::new(&mut d.fps).range(1.0..=999.0).speed(0.01).max_decimals(3)));
                     auto.add("dialog.comp.frameRate", r.rect, "Frame Rate");
-                    let r = egui::ComboBox::from_id_salt("comp-fps").width(18.0).selected_text("").show_ui(ui, |ui| {
+                    let r = craft_ui::ComboBox::from_id_salt("comp-fps").width(18.0).selected_text("").show_ui(ui, |ui| {
                         for f in FRAME_RATES {
                             if ui.selectable_label((d.fps - f).abs() < 1e-3, format!("{f}")).clicked() {
                                 d.fps = *f;
@@ -387,7 +387,7 @@ pub fn show(
                 // the frame it renders beside it.
                 ui.label(tr("Resolution:"));
                 ui.horizontal(|ui| {
-                    let r = egui::ComboBox::from_id_salt("comp-resolution").width(90.0).selected_text(tr(d.resolution.label())).show_ui(ui, |ui| {
+                    let r = craft_ui::ComboBox::from_id_salt("comp-resolution").width(90.0).selected_text(tr(d.resolution.label())).show_ui(ui, |ui| {
                         for res in Resolution::ALL {
                             ui.selectable_value(&mut d.resolution, res, tr(res.label()));
                         }
@@ -474,7 +474,7 @@ pub fn show(
         Tab::Renderer => {
             ui.horizontal(|ui| {
                 ui.label(tr("Renderer:"));
-                let r = egui::ComboBox::from_id_salt("comp-renderer").selected_text(tr(if d.advanced_3d { "Advanced 3D" } else { "Classic 3D" })).show_ui(
+                let r = craft_ui::ComboBox::from_id_salt("comp-renderer").selected_text(tr(if d.advanced_3d { "Advanced 3D" } else { "Classic 3D" })).show_ui(
                     ui,
                     |ui| {
                         ui.selectable_value(&mut d.advanced_3d, false, tr("Classic 3D"));
diff --git a/crates/ui-egui/src/panels/dialogs.rs b/crates/ui-egui/src/panels/dialogs.rs
index 47de23d59..7c89ad32d 100644
--- a/crates/ui-egui/src/panels/dialogs.rs
+++ b/crates/ui-egui/src/panels/dialogs.rs
@@ -536,7 +536,7 @@ fn solid(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
                 .find(|(_, v)| (v - par).abs() < 1e-3)
                 .map(|p| p.0.to_string())
                 .unwrap_or_else(|| format!("{par:.2}"));
-            let r = egui::ComboBox::from_id_salt("solid-par").width(240.0).selected_text(cur).show_ui(ui, |ui| {
+            let r = craft_ui::ComboBox::from_id_salt("solid-par").width(240.0).selected_text(cur).show_ui(ui, |ui| {
                 for (label, v) in super::comp_settings::PIXEL_ASPECTS {
                     if ui.selectable_label((v - par).abs() < 1e-3, *label).clicked() {
                         par = *v;
diff --git a/crates/ui-egui/src/panels/dialogs_3d.rs b/crates/ui-egui/src/panels/dialogs_3d.rs
index 01fd5b9e8..0a4636b87 100644
--- a/crates/ui-egui/src/panels/dialogs_3d.rs
+++ b/crates/ui-egui/src/panels/dialogs_3d.rs
@@ -172,7 +172,7 @@ pub fn camera(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
     super::dialogs::modal(ctx, "Camera Settings", vec2(520.0, 420.0), t, |ui| {
         egui::Grid::new("cam-grid").num_columns(2).spacing([14.0, 9.0]).show(ui, |ui| {
             ui.label(tr("Type"));
-            egui::ComboBox::from_id_salt("cam-type").selected_text(if d.two_node { "Two-Node Camera" } else { "One-Node Camera" }).show_ui(ui, |ui| {
+            craft_ui::ComboBox::from_id_salt("cam-type").selected_text(if d.two_node { "Two-Node Camera" } else { "One-Node Camera" }).show_ui(ui, |ui| {
                 ui.selectable_value(&mut d.two_node, true, tr("Two-Node Camera"));
                 ui.selectable_value(&mut d.two_node, false, tr("One-Node Camera"));
             });
@@ -184,7 +184,7 @@ pub fn camera(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
             ui.label(tr("Preset"));
             let focal = focal_for_zoom(w, d.zoom);
             let cur = PRESETS.iter().find(|(_, f)| (f - focal).abs() < 1e-6).map(|(n, _)| *n).unwrap_or("Custom");
-            egui::ComboBox::from_id_salt("cam-preset").selected_text(cur).show_ui(ui, |ui| {
+            craft_ui::ComboBox::from_id_salt("cam-preset").selected_text(cur).show_ui(ui, |ui| {
                 for (n, f) in PRESETS {
                     if ui.selectable_label(cur == n, n).clicked() {
                         d.zoom = zoom_for_focal(w, f);
@@ -268,7 +268,7 @@ pub fn light(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
             crate::widgets::focus_on_open(ui.ctx(), &r, &d.name);
             ui.end_row();
             ui.label(tr("Light Type"));
-            let combo = egui::ComboBox::from_id_salt("light-type").selected_text(tr(d.kind.label())).show_ui(ui, |ui| {
+            let combo = craft_ui::ComboBox::from_id_salt("light-type").selected_text(tr(d.kind.label())).show_ui(ui, |ui| {
                 for (i, k) in LightKind::ALL.into_iter().enumerate() {
                     let item = ui.selectable_value(&mut d.kind, k, tr(k.label()));
                     app.auto.add(&format!("dialog.light.typeItem.{i}"), item.rect, k.label());
@@ -292,7 +292,7 @@ pub fn light(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
             }
             if falls_off(d.kind) {
                 ui.label(tr("Falloff"));
-                egui::ComboBox::from_id_salt("light-falloff").selected_text(FALLOFFS[d.falloff.min(2)]).show_ui(ui, |ui| {
+                craft_ui::ComboBox::from_id_salt("light-falloff").selected_text(FALLOFFS[d.falloff.min(2)]).show_ui(ui, |ui| {
                     for (i, f) in FALLOFFS.iter().enumerate() {
                         ui.selectable_value(&mut d.falloff, i, *f);
                     }
diff --git a/crates/ui-egui/src/panels/effect_controls.rs b/crates/ui-egui/src/panels/effect_controls.rs
index 04f0a53a0..d9706f147 100644
--- a/crates/ui-egui/src/panels/effect_controls.rs
+++ b/crates/ui-egui/src/panels/effect_controls.rs
@@ -28,1655 +28,14 @@ use crate::state::FxPick;
 use crate::theme::Tokens;
 use crate::{EffectcraftApp, widgets};
 
-type Actions = Vec<(String, serde_json::Value)>;
+mod common;
+mod editors;
+mod panel;
+mod rows;
+mod viewer;
 
-const ROW: f32 = 20.0;
-const DIAL_ROW: f32 = 64.0;
-// The effect title starts at 44 pt. Each level's names sit one tree step farther in;
-// reserve the same icon gutter for properties and groups so sibling names align.
-const PARAM_NAME_X: f32 = 58.0;
-const TREE_INDENT: f32 = 14.0;
-
-/// Selecting any descendant activates its owning effect without replacing the property
-/// selection used by keyframe editing, copy and delete.
-fn effect_active(g: &PropGroup, layer: effectcraft_engine::project::LayerId, selected: &[(effectcraft_engine::project::LayerId, u64)]) -> bool {
-    fn contains(g: &PropGroup, uid: u64, depth: usize) -> bool {
-        if g.uid == uid {
-            return true;
-        }
-        if depth >= 16 {
-            return false;
-        }
-        g.children.iter().any(|n| n.uid() == uid || matches!(n, Node::Group(child) if contains(child, uid, depth + 1)))
-    }
-    selected.iter().any(|(l, uid)| *l == layer && contains(g, *uid, 0))
-}
-
-fn selected_layer(app: &EffectcraftApp) -> Option<Layer> {
-    let comp = app.session.active_comp()?;
-    let id = app.session.state.selected_layers.first()?;
-    comp.layer(*id).cloned()
-}
-
-/// An effect was just applied (`effect.apply` / `effect.applyLast` with `params`): Effect
-/// Controls comes up (opened if closed, brought to the front, the focus left where it is) on the
-/// layer the effect went to, with the new effect selected, as in After Effects.
-pub fn reveal_applied(app: &mut EffectcraftApp, params: &serde_json::Value) {
-    // `effect.apply` selects the new effect on (the last of) the layers it went to.
-    let target = app.session.state.selected_props.last().map(|(l, _)| *l);
-    if let Some(l) = target
-        && !app.session.state.selected_layers.contains(&l)
-        && params.get("comp").is_none()
-        && app.session.active_comp().is_some_and(|c| c.layer(l).is_some())
-    {
-        // Show that layer (dropped on an unselected one), keeping the new effect selected.
-        let props = app.session.state.selected_props.clone();
-        match app.session.execute("layer.select", json!({"layers": [l.0]})) {
-            Ok(_) => app.session.state.selected_props = props,
-            Err(e) => app.ui.status = e.to_string(),
-        }
-    }
-    app.raise_panel(crate::dock::PanelKind::EffectControls);
-}
-
-/// After Effects asks for an effect's file as it applies it (Apply Color LUT opens the file
-/// dialog for its LUT). For the instances `effect.apply` made (`applied`, its result), open the
-/// file dialog for their first empty file parameter and set the file on each; cancelling
-/// leaves the effect without one. Does nothing without a file dialog (tests, agents).
-pub fn choose_files_after_apply(app: &mut EffectcraftApp, applied: &serde_json::Value) {
-    let Some(pick) = app.hooks.pick_files.as_ref() else { return };
-    let Some(comp) = app.session.active_comp() else { return };
-    let uids: Vec<u64> = applied.get("effects").and_then(|v| v.as_array()).map(|a| a.iter().filter_map(|v| v.as_u64()).collect()).unwrap_or_default();
-    let mut targets = vec![];
-    let mut filters: Vec<String> = vec![];
-    for uid in uids {
-        for l in &comp.layers {
-            let Some(g) = l.props.find_group(uid) else { continue };
-            let mut found = None;
-            g.walk("", &mut |_, pr| {
-                if found.is_none()
-                    && let ParamUi::File { filters } = &pr.ui
-                    && matches!(&pr.value, Value::Str(s) if s.trim().is_empty())
-                {
-                    found = Some((pr.uid, filters.clone()));
-                }
-            });
-            if let Some((prop, f)) = found {
-                targets.push((l.id.0, prop));
-                filters = f;
-            }
-        }
-    }
-    if targets.is_empty() {
-        return;
-    }
-    let exts: Vec<&str> = filters.iter().map(String::as_str).collect();
-    let Some(path) = pick(&exts).into_iter().next() else { return };
-    for (layer, prop) in targets {
-        if let Err(e) = app.session.execute("prop.set", json!({"layer": layer, "prop": prop, "value": path})) {
-            app.ui.status = e.to_string();
-        }
-    }
-}
-
-/// An undo-merge key for one gesture on `id`: a new key each time a drag starts, so separate
-/// drags are separate undo steps while one drag is one step.
-pub(crate) fn gesture_key(ui: &egui::Ui, id: egui::Id, started: bool) -> String {
-    let kid = id.with("gesture");
-    let n: u64 = if started {
-        let n = ui.data(|d| d.get_temp::<u64>(kid)).unwrap_or(0) + 1;
-        ui.data_mut(|d| d.insert_temp(kid, n));
-        n
-    } else {
-        ui.data(|d| d.get_temp::<u64>(kid)).unwrap_or(0)
-    };
-    format!("{id:?}-{n}")
-}
-
-fn triangle(p: &egui::Painter, c: egui::Pos2, left: bool, col: Color32) {
-    let (dx, h) = (if left { -3.5 } else { 3.5 }, 4.0);
-    p.add(egui::Shape::convex_polygon(vec![pos2(c.x + dx, c.y), pos2(c.x - dx, c.y - h), pos2(c.x - dx, c.y + h)], col, Stroke::NONE));
-}
-
-/// ◀ ◆ ▶ at the right end of an animated parameter's row.
-fn key_navigator(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    p: &egui::Painter,
-    layer: &Layer,
-    prop: &Property,
-    ectx: &EvalCtx,
-    r: Rect,
-    actions: &mut Actions,
-) {
-    let t = app.tokens;
-    let cy = r.center().y;
-    let uid = prop.uid;
-    let half = ectx.comp.frame_duration().0 / 2;
-    let on_key = prop.keys.iter().any(|k| (layer.comp_time(k.time).0 - ectx.time.0).abs() <= half);
-    for (what, dx) in [("prev", -44.0), ("key", -32.0), ("next", -20.0)] {
-        let cr = Rect::from_center_size(pos2(r.max.x + dx, cy), vec2(12.0, 16.0));
-        let resp = ui.interact(cr, egui::Id::unique(("ec-nav", uid, what)), Sense::click());
-        let col = if resp.hovered() { t.text } else { t.text_dim };
-        match what {
-            "prev" => triangle(p, cr.center(), true, col),
-            "next" => triangle(p, cr.center(), false, col),
-            _ => {
-                let kr = Rect::from_center_size(cr.center(), vec2(10.0, 10.0));
-                if on_key {
-                    icons::paint(p, kr, Icon::Keyframe, t.keyframe);
-                } else {
-                    let c = kr.center();
-                    let d = 4.5;
-                    p.add(egui::Shape::closed_line(
-                        vec![pos2(c.x, c.y - d), pos2(c.x + d, c.y), pos2(c.x, c.y + d), pos2(c.x - d, c.y)],
-                        Stroke::new(1.0, col),
-                    ));
-                }
-            }
-        }
-        app.auto.add(&format!("effectControls.prop.{uid}.{what}Key"), cr, &prop.name);
-        if resp.clicked() {
-            match what {
-                "prev" => actions.push(("time.go".into(), json!({"to": "prevKey", "prop": uid}))),
-                "next" => actions.push(("time.go".into(), json!({"to": "nextKey", "prop": uid}))),
-                _ => actions.push(("prop.toggleKey".into(), json!({"layer": layer.id.0, "prop": uid, "selected": true}))),
-            }
-        }
-    }
-}
-
-/// Toggle a viewer pick (crosshair / eyedropper) for a parameter (also the Timeline's colour
-/// eyedroppers).
-pub(crate) fn toggle_pick(app: &mut EffectcraftApp, kind: &str, layer: &Layer, prop: &Property) {
-    let pick = FxPick { kind: kind.into(), layer: layer.id.0, prop: prop.uid, name: prop.name.clone() };
-    if app.ui.fx_pick.as_ref() == Some(&pick) {
-        app.ui.fx_pick = None;
-    } else {
-        app.ui.fx_pick = Some(pick);
-        app.ui.text_color_pick = None;
-        app.ui.status = if kind == "point" {
-            format!("Click in the Composition panel to set {}", prop.name)
-        } else {
-            format!("Click in the Composition panel to sample {}", prop.name)
-        };
-    }
-}
-
-/// One property row: stopwatch, name, value control (and the keyframe navigator). Returns the
-/// value fields of a vector, one per dimension, for the pick whip.
-#[allow(clippy::too_many_arguments)]
-fn prop_row(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    p: &egui::Painter,
-    layer: &Layer,
-    group: &PropGroup,
-    prop: &Property,
-    ectx: &EvalCtx,
-    r: Rect,
-    indent: f32,
-    actions: &mut Actions,
-) -> Vec<Rect> {
-    let t = app.tokens;
-    let mut dims = vec![];
-    let cy = r.center().y;
-    let uid = prop.uid;
-    if ui.input(|i| i.pointer.primary_pressed()) && ui.rect_contains_pointer(r) {
-        let add = ui.input(|i| i.modifiers.shift || i.modifiers.command);
-        actions.push(("prop.select".into(), json!({"layer": layer.id.0, "prop": uid, "add": add})));
-    }
-    let swr = Rect::from_center_size(pos2(r.min.x + indent, cy), vec2(14.0, 14.0));
-    if !prop.static_only && !matches!(prop.ui, ParamUi::Hidden) {
-        let resp = ui.interact(swr, egui::Id::unique(("ec-sw", uid)), Sense::click());
-        icons::paint(
-            p,
-            swr,
-            Icon::Stopwatch,
-            if prop.is_animated() {
-                t.hot_text
-            } else if resp.hovered() {
-                t.text
-            } else {
-                t.text_dim
-            },
-        );
-        app.auto.add(&format!("effectControls.prop.{uid}.stopwatch"), swr, &prop.name);
-        if resp.clicked() {
-            actions.push(("prop.toggleAnimation".into(), json!({"layer": layer.id.0, "prop": uid, "selected": true})));
-        }
-    }
-    if prop.is_animated() {
-        key_navigator(app, ui, p, layer, prop, ectx, r, actions);
-    }
-    let value = ectx.value(layer, prop);
-    // Keep a shared value column while names and their icons follow the group hierarchy.
-    // Extremely deep groups still leave a little name space before their value.
-    let vx = (r.min.x + r.width() * 0.48).max(r.min.x + PARAM_NAME_X + 124.0).max(swr.max.x + 40.0);
-    // A vector's values end before the keyframe navigator: in a narrow panel they move left over
-    // the name (cut short) instead of running under the navigator (#271).
-    let vx = match &value {
-        Value::Vec2(_) | Value::Vec3(_) => {
-            let point = if matches!(prop.ui, ParamUi::Point | ParamUi::Point3) { 22.0 } else { 0.0 };
-            let fields: f32 = value
-                .components()
-                .iter()
-                .take(shown_dims(layer, prop, &value))
-                .map(|v| p.layout_no_wrap(format!("{v:.1}"), Tokens::ui(12.0), t.hot_text).size().x + 12.0)
-                .sum();
-            let right = r.max.x - if prop.is_animated() { 52.0 } else { 8.0 };
-            vx.min(right - point - fields + 8.0).max(swr.max.x + 60.0)
-        }
-        _ => vx,
-    };
-    let name_clip = Rect::from_min_max(pos2(swr.max.x + 6.0, r.min.y), pos2(vx - 6.0, r.max.y));
-    app.auto.add(&format!("effectControls.prop.{uid}.name"), name_clip, &prop.name);
-    p.with_clip_rect(name_clip.intersect(p.clip_rect())).text(pos2(swr.max.x + 6.0, cy), Align2::LEFT_CENTER, &prop.name, Tokens::ui(12.0), t.text);
-    let name_response = ui.interact(name_clip, egui::Id::unique(("ec-prop-name", uid)), Sense::click());
-    if name_response.double_clicked() {
-        app.ui.timeline.search.clear();
-        app.ui.timeline.scroll_to = Some(crate::state::ScrollTo::Property(uid));
-        if let Err(e) = crate::menus::frontend(app, ui.ctx(), "timeline.revealProps", json!({"props": [{"layer": layer.id.0, "prop": uid}]})) {
-            app.ui.status = e;
-        }
-        app.show_panel(crate::dock::PanelKind::Timeline);
-    }
-    app.auto.add(&format!("effectControls.prop.{uid}.name"), name_clip, &prop.name);
-    let merge = format!("ec-{uid}");
-    // With several layers selected the edit applies to the same effect property of each (#491).
-    let scrub = ui.ctx().dragged_id().is_some() && ui.input(|i| i.pointer.is_decidedly_dragging());
-    let set = |actions: &mut Actions, v: serde_json::Value| {
-        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": uid, "value": v, "merge": merge, "selected": true, "offset": scrub})))
-    };
-    let twirl_open = |app: &mut EffectcraftApp, ui: &mut egui::Ui| {
-        let open = app.ui.fx_slider_open.contains(&uid);
-        let tw = Rect::from_center_size(pos2(swr.min.x - 9.0, cy), vec2(10.0, 10.0));
-        if widgets::twirl(ui, tw, open, egui::Id::unique(("ec-stw", uid)), &t).clicked() {
-            if open {
-                app.ui.fx_slider_open.remove(&uid);
-            } else {
-                app.ui.fx_slider_open.insert(uid);
-            }
-        }
-        app.auto.add(&format!("effectControls.prop.{uid}.twirl"), tw, &prop.name);
-    };
-    match &value {
-        Value::Scalar(v) if matches!(prop.ui, ParamUi::Mask) => {
-            // A mask of this layer ("Path" popup).
-            let mut opts = vec!["None".to_string()];
-            if let Some(m) = layer.masks() {
-                opts.extend(m.groups().map(|g| g.name.clone()));
-            }
-            let i = v.round().max(0.0) as usize;
-            let label = opts.get(i).cloned().unwrap_or_else(|| format!("Mask {i}"));
-            let dr = Rect::from_min_size(pos2(vx, cy - 9.0), vec2((r.max.x - vx - 56.0).clamp(80.0, 200.0), 18.0));
-            let pop = egui::Id::unique(("ec-mpop", uid));
-            if widgets::dropdown(ui, dr, &label, &t, egui::Id::unique(("ec-m", uid))).clicked() {
-                widgets::open_popup(ui, pop);
-            }
-            app.auto.add(&format!("effectControls.prop.{uid}.value"), dr, &prop.name);
-            if let Some(ni) = widgets::popup_menu(ui, pop, dr.left_bottom(), &opts, Some(i)) {
-                set(actions, json!(ni as f64));
-            }
-        }
-        Value::Scalar(v) if matches!(prop.ui, ParamUi::Angle) => {
-            let (rr, dr, nv) = fw::angle_field(ui, pos2(vx, cy - 9.0), egui::Id::unique(("ec-v", uid)), *v, 1, &t);
-            app.auto.add(&format!("effectControls.prop.{uid}.value"), rr.union(dr), &fw::format_angle(*v, 1));
-            app.auto.add(&format!("effectControls.prop.{uid}.revolutions"), rr, &prop.name);
-            if let Some(nv) = nv {
-                set(actions, json!(nv));
-            }
-            twirl_open(app, ui);
-        }
-        Value::Scalar(v) => {
-            let (min, max, dec) = match &prop.ui {
-                ParamUi::Slider { min, max, decimals, .. } => (*min, *max, *decimals as usize),
-                _ => (-1e9, 1e9, 1),
-            };
-            let suffix = match prop.ui {
-                ParamUi::Percent => "%",
-                _ => "",
-            };
-            let speed = widgets::slider_scrub_speed(&prop.ui);
-            let (vr, nv, _) = widgets::hot_number_at(
-                ui,
-                pos2(vx, cy - 9.0),
-                egui::Id::unique(("ec-v", uid)),
-                *v,
-                speed,
-                (min, max),
-                dec.max(if dec == 0 { 0 } else { 1 }),
-                suffix,
-                &t,
-            );
-            app.auto.add(&format!("effectControls.prop.{uid}.value"), vr, &prop.name);
-            if let Some(nv) = nv {
-                set(actions, json!(nv));
-            }
-            // AE hides a slider param's slider until its twirl is opened (see `slider_row`).
-            if matches!(prop.ui, ParamUi::Slider { .. }) {
-                twirl_open(app, ui);
-            }
-        }
-        Value::Vec2(_) | Value::Vec3(_) => {
-            let c = value.components();
-            let n = shown_dims(layer, prop, &value);
-            let mut x = vx;
-            if matches!(prop.ui, ParamUi::Point | ParamUi::Point3) {
-                let cr = Rect::from_center_size(pos2(x + 8.0, cy), vec2(18.0, 18.0));
-                let active = app.ui.fx_pick.as_ref().is_some_and(|k| k.prop == uid && k.kind == "point");
-                if fw::crosshair_button(ui, cr, active, egui::Id::unique(("ec-xh", uid)), &t)
-                    .on_hover_text(crate::i18n::tr("Click, then click in the Composition panel"))
-                    .clicked()
-                {
-                    toggle_pick(app, "point", layer, prop);
-                }
-                app.auto.add(&format!("effectControls.prop.{uid}.crosshair"), cr, &prop.name);
-                x += 22.0;
-            }
-            for d in 0..n.min(c.len()) {
-                let (vr, nv, _) = widgets::hot_number_at(ui, pos2(x, cy - 9.0), egui::Id::unique(("ec-v", uid, d)), c[d], 1.0, (-1e9, 1e9), 1, "", &t);
-                app.auto.add(&format!("effectControls.prop.{uid}.value.{d}"), vr, &prop.name);
-                dims.push(vr);
-                if let Some(nv) = nv {
-                    let mut nc = c.clone();
-                    nc[d] = nv;
-                    set(actions, json!(nc));
-                    // Typed into this component only: other selected layers keep the rest of
-                    // their own value (#1434).
-                    if let Some((_, a)) = actions.last_mut() {
-                        a["dims"] = json!([d]);
-                    }
-                }
-                x = vr.max.x + 8.0;
-            }
-        }
-        Value::Color(c) => {
-            let sr = Rect::from_min_size(pos2(vx, cy - 8.0), vec2(30.0, 16.0));
-            let pop = egui::Id::unique(("ec-cpop", uid));
-            if widgets::swatch(ui, sr, [c[0] as f32, c[1] as f32, c[2] as f32, 1.0], egui::Id::unique(("ec-c", uid)), &t).clicked() {
-                widgets::open_popup(ui, pop);
-            }
-            app.auto.add(&format!("effectControls.prop.{uid}.value"), sr, &prop.name);
-            let er = Rect::from_center_size(pos2(sr.max.x + 14.0, cy), vec2(18.0, 18.0));
-            let active = app.ui.fx_pick.as_ref().is_some_and(|k| k.prop == uid && k.kind == "color");
-            if fw::eyedropper_button(ui, er, active, egui::Id::unique(("ec-eye", uid)), &t)
-                .on_hover_text(crate::i18n::tr("Eyedropper: click, then click in the Composition panel"))
-                .clicked()
-            {
-                toggle_pick(app, "color", layer, prop);
-            }
-            app.auto.add(&format!("effectControls.prop.{uid}.eyedropper"), er, &prop.name);
-            let mut rgb = [c[0] as f32, c[1] as f32, c[2] as f32];
-            if crate::widgets::color_popup(ui, pop, sr.left_bottom(), &mut rgb) {
-                set(actions, json!([rgb[0], rgb[1], rgb[2], 1.0]));
-            }
-        }
-        Value::Bool(b) => {
-            let cr = Rect::from_min_size(pos2(vx, cy - 8.0), vec2(16.0, 16.0));
-            if widgets::checkbox(ui, cr, *b, &t, egui::Id::unique(("ec-b", uid))).clicked() {
-                set(actions, json!(!b));
-            }
-            p.text(pos2(cr.max.x + 6.0, cy), Align2::LEFT_CENTER, &prop.name, Tokens::ui(12.0), t.text_dim);
-            app.auto.add(&format!("effectControls.prop.{uid}.value"), cr, &prop.name);
-        }
-        Value::Enum(i) => {
-            if let ParamUi::Popup { options } = &prop.ui {
-                let widest = options.iter().map(|o| p.layout_no_wrap(o.clone(), Tokens::ui(11.5), t.text).size().x).fold(0.0, f32::max);
-                let dr = Rect::from_min_size(pos2(vx, cy - 9.0), vec2((widest + 30.0).clamp(80.0, (r.max.x - vx - 56.0).max(80.0)), 18.0));
-                let pop = egui::Id::unique(("ec-epop", uid));
-                if widgets::dropdown(ui, dr, options.get(*i as usize).map(String::as_str).unwrap_or(""), &t, egui::Id::unique(("ec-e", uid))).clicked() {
-                    widgets::open_popup(ui, pop);
-                }
-                app.auto.add(&format!("effectControls.prop.{uid}.value"), dr, &prop.name);
-                if let Some(ni) = widgets::popup_menu(ui, pop, dr.left_bottom(), options, Some(*i as usize)) {
-                    set(actions, json!(ni));
-                }
-            }
-        }
-        Value::Layer(l) => {
-            let comp = app.session.active_comp_arc();
-            if let Some(comp) = comp {
-                let dr = Rect::from_min_size(pos2(vx, cy - 9.0), vec2(((r.max.x - vx) * 0.55).clamp(90.0, 170.0), 18.0));
-                if let Some(chosen) = widgets::layer_picker(ui, dr, &comp.layers, *l, &t, egui::Id::unique(("ec-l", uid))) {
-                    set(actions, chosen.map(|id| json!(id)).unwrap_or(serde_json::Value::Null));
-                }
-                app.auto.add(&format!("effectControls.prop.{uid}.value"), dr, &prop.name);
-                // Source / Masks / Effects & Masks (the hidden companion parameter).
-                if let Some(src) = group.get(&effectcraft_engine::effects::layer_source_id(&prop.match_id)) {
-                    let si = src.value.as_enum() as usize;
-                    let opts: Vec<String> = effectcraft_engine::effects::LAYER_SOURCE_OPTIONS.iter().map(|s| s.to_string()).collect();
-                    let sr = Rect::from_min_size(pos2(dr.max.x + 6.0, cy - 9.0), vec2(((r.max.x - dr.max.x) - 64.0).clamp(70.0, 120.0), 18.0));
-                    let spop = egui::Id::unique(("ec-lspop", uid));
-                    if widgets::dropdown(ui, sr, opts.get(si).map(String::as_str).unwrap_or(""), &t, egui::Id::unique(("ec-ls", uid))).clicked() {
-                        widgets::open_popup(ui, spop);
-                    }
-                    app.auto.add(&format!("effectControls.prop.{uid}.source"), sr, &src.name);
-                    if let Some(ni) = widgets::popup_menu(ui, spop, sr.left_bottom(), &opts, Some(si)) {
-                        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": src.uid, "value": ni})));
-                    }
-                }
-            }
-        }
-        // EXtractoR's red / green / blue / alpha: a popup of the footage's OpenEXR channels (#295).
-        Value::Str(s) if super::fx_editors::is_extractor_channel(group, prop) => {
-            let dr = Rect::from_min_size(pos2(vx, cy - 9.0), vec2((r.max.x - vx - 56.0).clamp(80.0, 200.0), 18.0));
-            super::fx_editors::channel_popup(app, ui, layer, prop, s, dr, actions);
-        }
-        // A file parameter (Apply Color LUT's LUT, an OCIO config): its file name and Choose…,
-        // as in After Effects.
-        Value::Str(s) if matches!(prop.ui, ParamUi::File { .. }) => {
-            let bw = 70.0;
-            let br = Rect::from_min_size(pos2(vx, cy - 9.0), vec2(bw, 18.0));
-            if widgets::text_button(ui, br, crate::i18n::tr("Choose..."), false, &t, egui::Id::unique(("ec-file", uid))).clicked() {
-                let filters: Vec<&str> = match &prop.ui {
-                    ParamUi::File { filters } => filters.iter().map(String::as_str).collect(),
-                    _ => vec![],
-                };
-                match app.hooks.pick_files.as_ref() {
-                    Some(pick) => {
-                        if let Some(path) = pick(&filters).into_iter().next() {
-                            actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": uid, "value": path})));
-                        }
-                    }
-                    None => app.ui.status = "no file dialog available: set the path with prop.set".into(),
-                }
-            }
-            app.auto.add(&format!("effectControls.prop.{uid}.choose"), br, &prop.name);
-            let shown = if s.trim().is_empty() {
-                crate::i18n::tr("None").to_string()
-            } else if s.contains('\n') {
-                prop.name.clone()
-            } else {
-                effectcraft_engine::sequence::file_name(s)
-            };
-            let nr = Rect::from_min_max(pos2(br.max.x + 8.0, r.min.y), pos2(r.max.x - 8.0, r.max.y));
-            let np = p.with_clip_rect(nr.intersect(p.clip_rect()));
-            np.text(pos2(nr.min.x, cy), Align2::LEFT_CENTER, &shown, Tokens::ui(12.0), if s.trim().is_empty() { t.text_dim } else { t.text });
-            let hover = ui.interact(nr, egui::Id::unique(("ec-file-name", uid)), Sense::hover());
-            if !s.trim().is_empty() && !s.contains('\n') {
-                hover.on_hover_text(s.as_str());
-            }
-            app.auto.add(&format!("effectControls.prop.{uid}.value"), nr, &shown);
-        }
-        // A text parameter (Cryptomatte's Selection, Colorama's Output Cycle, config names):
-        // typed in a field, set when it loses the focus (Esc keeps the old text).
-        Value::Str(s) if matches!(prop.ui, ParamUi::Text) => {
-            let fr = Rect::from_min_size(pos2(vx, cy - 9.0), vec2((r.max.x - vx - 12.0).clamp(80.0, 320.0), 18.0));
-            let bid = egui::Id::unique(("ec-text", uid));
-            let mut buf: String = ui.data(|d| d.get_temp(bid)).unwrap_or_else(|| s.clone());
-            let resp = widgets::text_field(ui, fr, &mut buf, "", &t);
-            // The field has no visible hint: give the screen reader the parameter's name.
-            resp.widget_info(|| egui::WidgetInfo::labeled(egui::Role::TextInput, ui.is_enabled(), &prop.name));
-            app.auto.add(&format!("effectControls.prop.{uid}.value"), fr, &prop.name);
-            if resp.lost_focus() {
-                if buf != *s && !ui.input(|i| i.key_pressed(egui::Key::Escape)) {
-                    actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": uid, "value": buf})));
-                }
-                ui.data_mut(|d| d.remove::<String>(bid));
-            } else if resp.has_focus() {
-                ui.data_mut(|d| d.insert_temp(bid, buf));
-            }
-        }
-        Value::Gradient(g) => {
-            let gr = Rect::from_min_size(pos2(vx, cy - 7.0), vec2((r.max.x - vx - 56.0).clamp(60.0, 180.0), 14.0));
-            let n = 48;
-            for k in 0..n {
-                let f = k as f64 / (n - 1) as f64;
-                let c = gradient_at(g, f);
-                let x0 = gr.min.x + gr.width() * k as f32 / n as f32;
-                let x1 = gr.min.x + gr.width() * (k + 1) as f32 / n as f32;
-                p.rect_filled(Rect::from_min_max(pos2(x0, gr.min.y), pos2(x1, gr.max.y)), 0.0, c);
-            }
-            p.rect_stroke(gr, 2.0, Stroke::new(1.0, t.field_border), egui::StrokeKind::Inside);
-            app.auto.add(&format!("effectControls.prop.{uid}.value"), gr, &prop.name);
-        }
-        _ => {}
-    }
-    dims
-}
-
-/// How many of a vector parameter's values show (a 3D point's Z only on a 3D layer).
-fn shown_dims(layer: &Layer, prop: &Property, value: &Value) -> usize {
-    let n = value.components().len();
-    if prop.shown_dims > 0 && !(layer.is_3d() && n == 3) { prop.shown_dims as usize } else { n }
-}
-
-/// Colour of a gradient at `f` (colour stops only).
-fn gradient_at(g: &effectcraft_engine::keyframe::Gradient, f: f64) -> Color32 {
-    let stops = &g.colors;
-    let c = if stops.is_empty() {
-        [0.0, 0.0, 0.0, 1.0]
-    } else if f <= stops[0].0 {
-        stops[0].1
-    } else if f >= stops[stops.len() - 1].0 {
-        stops[stops.len() - 1].1
-    } else {
-        let i = stops.iter().position(|s| s.0 > f).unwrap_or(stops.len() - 1).max(1);
-        let (a, b) = (stops[i - 1], stops[i]);
-        let k = ((f - a.0) / (b.0 - a.0).max(1e-9)) as f32;
-        [0, 1, 2, 3].map(|j| a.1[j] + (b.1[j] - a.1[j]) * k)
-    };
-    Color32::from_rgb((c[0].clamp(0.0, 1.0) * 255.0) as u8, (c[1].clamp(0.0, 1.0) * 255.0) as u8, (c[2].clamp(0.0, 1.0) * 255.0) as u8)
-}
-
-/// The twirled-open slider under a slider param: track, knob and the slider range's ends.
-#[allow(clippy::too_many_arguments)]
-fn slider_row(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    p: &egui::Painter,
-    layer: &Layer,
-    prop: &Property,
-    ectx: &EvalCtx,
-    r: Rect,
-    x0: f32,
-    actions: &mut Actions,
-) {
-    let t = app.tokens;
-    let ParamUi::Slider { slider_min, slider_max, decimals, .. } = prop.ui else { return };
-    let Value::Scalar(v) = ectx.value(layer, prop) else { return };
-    let uid = prop.uid;
-    let tr = Rect::from_min_max(pos2(r.min.x + x0, r.min.y + 8.0), pos2(r.max.x - 16.0, r.min.y + 12.0));
-    if tr.width() < 40.0 {
-        return;
-    }
-    p.rect_filled(tr, 2.0, t.field_bg);
-    let f = ((v - slider_min) / (slider_max - slider_min)).clamp(0.0, 1.0) as f32;
-    p.rect_filled(Rect::from_min_max(tr.min, pos2(tr.min.x + tr.width() * f, tr.max.y)), 2.0, t.accent.gamma_multiply(0.7));
-    p.circle_filled(pos2(tr.min.x + tr.width() * f, tr.center().y), 5.0, t.text);
-    let dec = decimals as usize;
-    p.text(pos2(tr.min.x, tr.max.y + 4.0), Align2::LEFT_TOP, format!("{slider_min:.dec$}"), Tokens::ui(10.5), t.text_dim);
-    p.text(pos2(tr.max.x, tr.max.y + 4.0), Align2::RIGHT_TOP, format!("{slider_max:.dec$}"), Tokens::ui(10.5), t.text_dim);
-    let sresp = ui.interact(tr.expand2(vec2(4.0, 6.0)), egui::Id::unique(("ec-slider", uid)), Sense::click_and_drag());
-    app.auto.add(&format!("effectControls.prop.{uid}.slider"), tr, &prop.name);
-    if (sresp.dragged() || sresp.clicked())
-        && let Some(pt) = sresp.interact_pointer_pos()
-    {
-        let f = ((pt.x - tr.min.x) / tr.width()).clamp(0.0, 1.0) as f64;
-        actions.push((
-            "prop.set".into(),
-            json!({"layer": layer.id.0, "prop": uid, "value": slider_min + (slider_max - slider_min) * f, "merge": format!("ec-{uid}")}),
-        ));
-    }
-}
-
-/// The twirled-open angle dial under an angle param.
-#[allow(clippy::too_many_arguments)]
-fn dial_row(app: &mut EffectcraftApp, ui: &mut egui::Ui, layer: &Layer, prop: &Property, ectx: &EvalCtx, r: Rect, x0: f32, actions: &mut Actions) {
-    let t = app.tokens;
-    let Value::Scalar(v) = ectx.value(layer, prop) else { return };
-    let uid = prop.uid;
-    let d = (r.height() - 12.0).min(52.0);
-    let dr = Rect::from_min_size(pos2(r.min.x + x0 + 40.0, r.min.y + 6.0), vec2(d, d));
-    let id = egui::Id::unique(("ec-dial", uid));
-    let (resp, nv) = fw::angle_dial(ui, dr, v, id, &t);
-    app.auto.add(&format!("effectControls.prop.{uid}.dial"), dr, &prop.name);
-    if let Some(nv) = nv {
-        let key = gesture_key(ui, id, resp.drag_started() || resp.clicked());
-        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": uid, "value": nv, "merge": key})));
-    }
-}
-
-/// The effect instance a row belongs to, for conditional visibility
-/// ([`effectcraft_engine::effects::catalog::param_shown`]): effect id, the instance's root
-/// group and the spec-id path of the group being drawn (`""` or `cameraPosition/`).
-struct FxScope<'a> {
-    effect: &'a str,
-    root: &'a PropGroup,
-    path: String,
-}
-
-impl<'a> FxScope<'a> {
-    fn sub(&self, m: &str) -> FxScope<'a> {
-        FxScope { effect: self.effect, root: self.root, path: format!("{}{m}/", self.path) }
-    }
-    /// Whether child `m` of the current group is shown.
-    fn shown(&self, layer: &Layer, ectx: &EvalCtx, m: &str) -> bool {
-        let root = self.root;
-        let value = |id: &str| -> Option<Value> {
-            let mut g = root;
-            let mut parts = id.split('/').peekable();
-            while let Some(part) = parts.next() {
-                if parts.peek().is_none() {
-                    return g.get(part).map(|p| ectx.value(layer, p));
-                }
-                g = g.sub(part)?;
-            }
-            None
-        };
-        effectcraft_engine::effects::catalog::param_shown(self.effect, &format!("{}{m}", self.path), &value)
-    }
-}
-
-/// Twirl `g` closed (it was `open`) or open; with `all` (Alt/Cmd-click) every group under it follows.
-fn toggle_closed(app: &mut EffectcraftApp, g: &PropGroup, open: bool, all: bool) {
-    fn walk(g: &PropGroup, out: &mut Vec<u64>) {
-        for sg in g.groups() {
-            out.push(sg.uid);
-            walk(sg, out);
-        }
-    }
-    let mut uids = vec![g.uid];
-    if all {
-        walk(g, &mut uids);
-    }
-    for u in uids {
-        if open {
-            app.ui.fx_closed.insert(u);
-        } else {
-            app.ui.fx_closed.remove(&u);
-        }
-    }
-}
-
-/// Lays out one property group's rows below `*y` (which it advances), recursing into open
-/// subgroups: one row per visible property with its controls, plus the dial or slider row when its
-/// slider is open, and an inline editor for groups that have one. Rows scrolled out of `rect` are
-/// skipped without being drawn or registered, though their height is still counted. Pick-whip
-/// drops are registered for each visible property; edits go on `actions`.
-#[allow(clippy::too_many_arguments)]
-fn group_rows(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    p: &egui::Painter,
-    layer: &Layer,
-    g: &PropGroup,
-    ectx: &EvalCtx,
-    rect: Rect,
-    y: &mut f32,
-    depth: usize,
-    fx: &FxScope,
-    actions: &mut Actions,
-) {
-    let t = app.tokens;
-    for c in &g.children {
-        let r = Rect::from_min_size(pos2(rect.min.x, *y), vec2(rect.width(), ROW));
-        match c {
-            Node::Prop(pr) => {
-                if matches!(pr.ui, ParamUi::Hidden) || pr.three_d_only && !layer.is_3d() || !fx.shown(layer, ectx, &pr.match_id) {
-                    continue;
-                }
-                *y += ROW;
-                let indent = PARAM_NAME_X - 13.0 + TREE_INDENT * depth as f32;
-                let visible = !(r.max.y < rect.min.y || r.min.y > rect.max.y);
-                if visible {
-                    app.auto.add(&format!("effectControls.row.{}", pr.uid), r, &pr.name);
-                    let dims = prop_row(app, ui, p, layer, g, pr, ectx, r, indent, actions);
-                    // A Timeline pick whip can be dropped here (After Effects).
-                    super::timeline::whip_target(ui.ctx(), r.intersect(rect), layer.id.0, pr.uid, dims);
-                }
-                if app.ui.fx_slider_open.contains(&pr.uid) {
-                    if matches!(pr.ui, ParamUi::Angle) {
-                        let sr = Rect::from_min_size(pos2(rect.min.x, *y), vec2(rect.width(), DIAL_ROW));
-                        *y += DIAL_ROW;
-                        if sr.max.y >= rect.min.y && sr.min.y <= rect.max.y {
-                            dial_row(app, ui, layer, pr, ectx, sr, indent + 22.0, actions);
-                        }
-                    } else if matches!(pr.ui, ParamUi::Slider { .. }) {
-                        let sr = Rect::from_min_size(pos2(rect.min.x, *y), vec2(rect.width(), 34.0));
-                        *y += 34.0;
-                        if sr.max.y >= rect.min.y && sr.min.y <= rect.max.y {
-                            slider_row(app, ui, p, layer, pr, ectx, sr, indent + 22.0, actions);
-                        }
-                    }
-                }
-            }
-            Node::Group(sg) => {
-                // Paint strokes live in the Timeline only (AE's Paint shows Paint on Transparent).
-                if effectcraft_engine::effects::paint::is_paint(g) || !fx.shown(layer, ectx, &sg.match_id) {
-                    continue;
-                }
-                *y += ROW;
-                let open = !app.ui.fx_closed.contains(&sg.uid);
-                let tw = Rect::from_center_size(pos2(r.min.x + PARAM_NAME_X - 12.0 + TREE_INDENT * depth as f32, r.center().y), vec2(12.0, 12.0));
-                if r.max.y >= rect.min.y && r.min.y <= rect.max.y {
-                    app.auto.add(&format!("effectControls.row.{}", sg.uid), r, &sg.name);
-                    app.auto.add(&format!("effectControls.group.{}.twirl", sg.uid), tw, &sg.name);
-                    if widgets::twirl(ui, tw, open, egui::Id::unique(("ec-g", sg.uid)), &t).clicked() {
-                        toggle_closed(app, sg, open, ui.input(|i| i.modifiers.alt || i.modifiers.command));
-                    }
-                    let name = p.text(pos2(tw.max.x + 6.0, r.center().y), Align2::LEFT_CENTER, &sg.name, Tokens::ui(12.0), t.text);
-                    app.auto.add(&format!("effectControls.group.{}.name", sg.uid), name, &sg.name);
-                }
-                if open {
-                    let sub = fx.sub(&sg.match_id);
-                    // A visual editor for the group's hidden parameters (Lumetri curves, …).
-                    let eh = super::fx_editors::inline_height(fx.effect, &sub.path, rect.width());
-                    if eh > 0.0 {
-                        let er = Rect::from_min_size(pos2(rect.min.x, *y), vec2(rect.width(), eh));
-                        *y += eh;
-                        if er.max.y >= rect.min.y && er.min.y <= rect.max.y {
-                            super::fx_editors::inline_editor(app, ui, p, layer, fx.root, sg, fx.effect, &sub.path, ectx, er, actions);
-                        }
-                    }
-                    group_rows(app, ui, p, layer, sg, ectx, rect, y, depth + 1, &sub, actions);
-                }
-            }
-        }
-    }
-}
-
-/// Warp Stabilizer's Analyze / Cancel buttons and analysis status.
-fn warp_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, layer: &Layer, g: &PropGroup, r: Rect, actions: &mut Actions) {
-    let t = app.tokens;
-    let running = app.session.warp_target().is_some_and(|(_, l, u)| l == layer.id && u == g.uid) && app.session.is_warp_analyzing();
-    let busy = app.session.is_warp_analyzing();
-    let b1 = Rect::from_min_size(pos2(r.min.x + 24.0, r.min.y + 4.0), vec2(84.0, 22.0));
-    let b2 = Rect::from_min_size(pos2(b1.max.x + 8.0, b1.min.y), vec2(84.0, 22.0));
-    if widgets::text_button(ui, b1, "Analyze", false, &t, egui::Id::unique(("warp-analyze", g.uid))).clicked() && !busy {
-        actions.push(("warp.analyze".into(), json!({"layer": layer.id.0, "effect": g.uid})));
-    }
-    app.auto.add(&format!("effectControls.warp.{}.analyze", g.uid), b1, "Analyze");
-    if running {
-        if widgets::text_button(ui, b2, "Cancel", false, &t, egui::Id::unique(("warp-cancel", g.uid))).clicked() {
-            actions.push(("warp.cancel".into(), json!({})));
-        }
-        app.auto.add(&format!("effectControls.warp.{}.cancel", g.uid), b2, "Cancel");
-    }
-    let analysed = matches!(g.get(effectcraft_engine::effects::warp_stab::ANALYSIS).map(|p| &p.value), Some(Value::Str(s)) if !s.is_empty());
-    let status = match app.session.warp_progress() {
-        Some(pr) if running => pr.banner(),
-        _ if analysed => "Analysis complete".to_string(),
-        _ if app.session.warp_pending.iter().any(|(_, l, u)| *l == layer.id && *u == g.uid) => "Waiting to analyze".to_string(),
-        _ => "Not analyzed: click Analyze".to_string(),
-    };
-    p.text(pos2(r.min.x + 24.0, r.min.y + 38.0), Align2::LEFT_CENTER, status, Tokens::ui(11.5), t.text_dim);
-}
-
-/// Roto Brush & Refine Edge: Freeze / Unfreeze and Propagate buttons and the segmentation status.
-fn roto_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, layer: &Layer, g: &PropGroup, r: Rect, actions: &mut Actions) {
-    use effectcraft_engine::effects::roto as fx;
-    let t = app.tokens;
-    let params = effectcraft_engine::effects::flatten_params(g, &mut |pr| pr.value.clone());
-    let frozen = fx::is_frozen(&params);
-    let d = fx::data(&params);
-    let running = app.session.roto_target().is_some_and(|(_, l, u, _)| l == layer.id && u == g.uid) && app.session.is_roto_running();
-    let b1 = Rect::from_min_size(pos2(r.min.x + 24.0, r.min.y + 4.0), vec2(84.0, 22.0));
-    let b2 = Rect::from_min_size(pos2(b1.max.x + 8.0, b1.min.y), vec2(84.0, 22.0));
-    let label = if frozen { "Unfreeze" } else { "Freeze" };
-    if widgets::text_button(ui, b1, label, frozen, &t, egui::Id::unique(("roto-freeze-ec", g.uid))).clicked() && !running {
-        let id = if frozen { "roto.unfreeze" } else { "roto.freeze" };
-        actions.push((id.into(), json!({"layer": layer.id.0, "effect": g.uid})));
-    }
-    app.auto.add(&format!("effectControls.roto.{}.freeze", g.uid), b1, label);
-    let (l2, id2) = if running { ("Stop", "roto.cancel") } else { ("Propagate", "roto.propagate") };
-    if widgets::text_button(ui, b2, l2, false, &t, egui::Id::unique(("roto-prop-ec", g.uid))).clicked() && !frozen {
-        actions.push((id2.into(), json!({"layer": layer.id.0, "effect": g.uid})));
-    }
-    app.auto.add(&format!("effectControls.roto.{}.propagate", g.uid), b2, l2);
-    let status = match (app.session.roto_progress(), d.base) {
-        (Some(pr), _) if running => pr.banner(),
-        (_, None) => "No strokes: paint with the Roto Brush tool (Alt+W) in the Layer panel".to_string(),
-        (_, Some(b)) => format!("Base frame {b}, span {}–{}{}", d.span[0], d.span[1], if frozen { " (frozen)" } else { "" }),
-    };
-    p.text(pos2(r.min.x + 24.0, r.min.y + 38.0), Align2::LEFT_CENTER, status, Tokens::ui(11.5), t.text_dim);
-}
-
-/// Object Matte: Freeze / Unfreeze and Track / Stop buttons (the background job that computes
-/// the matte over the tracked frames) and its status.
-fn object_matte_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, layer: &Layer, g: &PropGroup, r: Rect, actions: &mut Actions) {
-    use effectcraft_engine::effects::object_matte as om;
-    let t = app.tokens;
-    let params = effectcraft_engine::effects::flatten_params(g, &mut |pr| pr.value.clone());
-    let frozen = om::is_frozen(&params);
-    let mine = app.session.roto_target().is_some_and(|(_, l, u, _)| l == layer.id && u == g.uid);
-    let running = mine && app.session.is_roto_running();
-    let busy = app.session.is_roto_running();
-    let b1 = Rect::from_min_size(pos2(r.min.x + 24.0, r.min.y + 4.0), vec2(84.0, 22.0));
-    let b2 = Rect::from_min_size(pos2(b1.max.x + 8.0, b1.min.y), vec2(84.0, 22.0));
-    let label = if frozen { "Unfreeze" } else { "Freeze" };
-    if widgets::text_button(ui, b1, crate::i18n::tr(label), frozen, &t, egui::Id::unique(("om-freeze-ec", g.uid))).clicked() && !busy {
-        let id = if frozen { "objectMatte.unfreeze" } else { "objectMatte.freeze" };
-        actions.push((id.into(), json!({"layer": layer.id.0, "effect": g.uid})));
-    }
-    app.auto.add(&format!("effectControls.objectMatte.{}.freeze", g.uid), b1, label);
-    let (l2, id2) = if running { ("Stop", "roto.cancel") } else { ("Track", "objectMatte.propagate") };
-    if widgets::text_button(ui, b2, crate::i18n::tr(l2), false, &t, egui::Id::unique(("om-track-ec", g.uid))).clicked() && !frozen && (running || !busy) {
-        actions.push((id2.into(), json!({"layer": layer.id.0, "effect": g.uid})));
-    }
-    app.auto.add(&format!("effectControls.objectMatte.{}.track", g.uid), b2, l2);
-    let base = om::reference_frame(&params);
-    let status = match app.session.roto_progress() {
-        Some(pr) if running => pr.banner(),
-        _ if frozen => format!("Frozen from reference frame {base}"),
-        _ if app.session.roto_pending.iter().any(|(_, l, u)| *l == layer.id && *u == g.uid) => "Waiting to track".to_string(),
-        _ => format!("Reference frame {base}: Track computes the matte ahead of playback"),
-    };
-    p.text(pos2(r.min.x + 24.0, r.min.y + 38.0), Align2::LEFT_CENTER, &status, Tokens::ui(11.5), t.text_dim);
-    app.auto.add(
-        &format!("effectControls.objectMatte.{}.status", g.uid),
-        Rect::from_min_size(pos2(r.min.x + 24.0, r.min.y + 30.0), vec2(r.width() - 24.0, 16.0)),
-        &status,
-    );
-}
-
-// ---------------------------------------------------------------------------------------------
-// Curves / Levels editors
-
-/// Height of the custom editor shown under an effect's header (0 when none).
-fn editor_height(effect: &str, g: &PropGroup, width: f32) -> f32 {
-    match effect {
-        super::fx_editors::GLOW | super::fx_editors::RESHAPE | super::fx_editors::EXTRACTOR => super::fx_editors::header_height(effect, g, width),
-        "ec.color.curves" => 34.0 + curves_size(width) + 26.0,
-        effectcraft_engine::effects::warp_stab::ID => 50.0,
-        effectcraft_engine::effects::camera_tracker::ID => super::camera_tracker_ui::EDITOR_HEIGHT,
-        effectcraft_engine::effects::roto::ID | effectcraft_engine::effects::object_matte::ID => 50.0,
-        "ec.color.levels" | "ec.color.levelsic" => 34.0 + 80.0 + 58.0,
-        "ec.color.autolevels" | "ec.color.autocontrast" | "ec.color.autocolor" => 24.0 + 80.0 + 12.0,
-        _ => 0.0,
-    }
-}
-
-fn curves_size(width: f32) -> f32 {
-    (width - 72.0).clamp(120.0, 256.0)
-}
-
-/// Cached histogram of the displayed frame (recomputed when the frame changes).
-fn frame_histogram(app: &mut EffectcraftApp, ctx: &egui::Context) -> Option<std::sync::Arc<[[u32; 256]; 5]>> {
-    let img = app.viewer_pixels()?;
-    let key = std::sync::Arc::as_ptr(&img) as usize;
-    let id = egui::Id::unique("ec-histogram");
-    if let Some((k, h)) = ctx.data(|d| d.get_temp::<(usize, std::sync::Arc<[[u32; 256]; 5]>)>(id))
-        && k == key
-    {
-        return Some(h);
-    }
-    let h = std::sync::Arc::new(fw::histogram(&img));
-    ctx.data_mut(|d| d.insert_temp(id, (key, h.clone())));
-    Some(h)
-}
-
-fn channel_color(ch: usize) -> Color32 {
-    match ch {
-        1 => Color32::from_rgb(0xe0, 0x50, 0x50),
-        2 => Color32::from_rgb(0x50, 0xc8, 0x60),
-        3 => Color32::from_rgb(0x50, 0x80, 0xf0),
-        4 => Color32::from_gray(0x90),
-        _ => Color32::from_gray(0xb8),
-    }
-}
-
-/// A "Channel: [RGB ▾]" popup; returns the chosen channel.
-#[allow(clippy::too_many_arguments)]
-fn channel_popup(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    p: &egui::Painter,
-    x: f32,
-    cy: f32,
-    cur: usize,
-    names: &[&str],
-    id: egui::Id,
-    auto: &str,
-) -> Option<usize> {
-    let t = app.tokens;
-    p.text(pos2(x, cy), Align2::LEFT_CENTER, crate::i18n::tr("Channel:"), Tokens::ui(12.0), t.text_dim);
-    let dr = Rect::from_min_size(pos2(x + 58.0, cy - 9.0), vec2(80.0, 18.0));
-    let pop = id.with("pop");
-    if widgets::dropdown(ui, dr, names.get(cur).copied().unwrap_or(""), &t, id).clicked() {
-        widgets::open_popup(ui, pop);
-    }
-    app.auto.add(auto, dr, "Channel");
-    let opts: Vec<String> = names.iter().map(|s| s.to_string()).collect();
-    widgets::popup_menu(ui, pop, dr.left_bottom(), &opts, Some(cur))
-}
-
-/// Curves: channel popup, Bezier/pencil mode, Reset, and the graph bound to the channel's
-/// hidden point-list parameter.
-#[allow(clippy::too_many_arguments)]
-fn curves_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, layer: &Layer, g: &PropGroup, ectx: &EvalCtx, r: Rect, actions: &mut Actions) {
-    let t = app.tokens;
-    let euid = g.uid;
-    // The channel lives in the effect's hidden Channel parameter (UI state for instances
-    // saved before it existed).
-    let chan_prop = g.get("channel");
-    let ch = match chan_prop {
-        Some(pr) => ectx.value(layer, pr).as_enum() as usize,
-        None => app.ui.fx_curve_channel.get(&euid).copied().unwrap_or(0),
-    }
-    .min(4);
-    let x0 = r.min.x + 30.0;
-    let cy = r.min.y + 17.0;
-    let names: [&str; 5] = [crate::i18n::tr("RGB"), crate::i18n::tr("Red"), crate::i18n::tr("Green"), crate::i18n::tr("Blue"), crate::i18n::tr("Alpha")];
-    if let Some(n) = channel_popup(app, ui, p, x0, cy, ch, &names, egui::Id::unique(("ec-cch", euid)), &format!("effectControls.effect.{euid}.curves.channel"))
-    {
-        match chan_prop {
-            Some(pr) => actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": pr.uid, "value": n}))),
-            None => {
-                app.ui.fx_curve_channel.insert(euid, n);
-            }
-        }
-    }
-    let pencil = app.ui.fx_curve_pencil.contains(&euid);
-    let mr = Rect::from_min_size(pos2(x0 + 146.0, cy - 9.0), vec2(56.0, 18.0));
-    if widgets::dropdown(ui, mr, if pencil { "Pencil" } else { "Bezier" }, &t, egui::Id::unique(("ec-cmode", euid))).clicked() {
-        if pencil {
-            app.ui.fx_curve_pencil.remove(&euid);
-        } else {
-            app.ui.fx_curve_pencil.insert(euid);
-        }
-    }
-    app.auto.add(&format!("effectControls.effect.{euid}.curves.mode"), mr, "Curve mode");
-    let Some(prop) = g.get(fw::CURVE_CHANNELS[ch].0) else { return };
-    let cur = match ectx.value(layer, prop) {
-        Value::Str(s) => fw::CurvePoints::parse(&s),
-        _ => fw::CurvePoints::identity(),
-    };
-    let rr = Rect::from_min_size(pos2(mr.max.x + 8.0, cy - 9.0), vec2(44.0, 18.0));
-    let rresp = ui.interact(rr, egui::Id::unique(("ec-creset", euid)), Sense::click());
-    p.text(rr.center(), Align2::CENTER_CENTER, crate::i18n::tr("Reset"), Tokens::ui(11.5), if rresp.hovered() { t.hot_text } else { t.text_dim });
-    app.auto.add(&format!("effectControls.effect.{euid}.curves.reset"), rr, "Reset curve");
-    if rresp.clicked() {
-        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": prop.uid, "value": fw::CurvePoints::identity().format()})));
-    }
-    let size = curves_size(r.width());
-    let gr = Rect::from_min_size(pos2(x0 + 8.0, r.min.y + 38.0), vec2(size, size));
-    // Input/output gradients along the axes.
-    let col = channel_color(ch);
-    p.rect_filled(Rect::from_min_max(pos2(gr.min.x, gr.max.y + 3.0), pos2(gr.max.x, gr.max.y + 8.0)), 0.0, col.gamma_multiply(0.5));
-    let id = egui::Id::unique(("ec-curves", euid, ch));
-    let (resp, edit) = fw::curves_graph(ui, gr, &cur, ch, fw::CurveMode { pencil, natural: true }, id, &t);
-    app.auto.add(&format!("effectControls.effect.{euid}.curves.graph"), gr, "Curves");
-    let started = resp.drag_started() || resp.clicked();
-    if let Some(np) = edit.changed {
-        let key = gesture_key(ui, id, started);
-        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": prop.uid, "value": np.format(), "merge": key})));
-    }
-    p.text(
-        pos2(gr.min.x, gr.max.y + 18.0),
-        Align2::LEFT_CENTER,
-        if pencil { "Drag to draw the curve" } else { "Click adds a point; drag one off to remove" },
-        Tokens::ui(10.5),
-        t.text_faint,
-    );
-}
-
-/// Levels parameter ids for a channel: input black, input white, gamma, output black, output white.
-fn levels_ids(effect: &str, ch: usize) -> [String; 5] {
-    if effect == "ec.color.levels" {
-        return effectcraft_engine::effects::levels_channel_ids(ch);
-    }
-    // Levels (Individual Controls) nests each channel's controls in its twirl-down group.
-    let pre = fw::LEVELS_CHANNELS[ch.min(4)].0;
-    ["InBlack", "InWhite", "Gamma", "OutBlack", "OutWhite"].map(|s| format!("{pre}/{pre}{s}"))
-}
-
-/// Levels: (channel popup,) histogram, input black/gamma/white triangles, output bar with
-/// black/white triangles.
-#[allow(clippy::too_many_arguments)]
-fn levels_editor(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    p: &egui::Painter,
-    layer: &Layer,
-    g: &PropGroup,
-    effect: &str,
-    ectx: &EvalCtx,
-    r: Rect,
-    actions: &mut Actions,
-) {
-    let t = app.tokens;
-    let euid = g.uid;
-    let x0 = r.min.x + 30.0;
-    let cy = r.min.y + 17.0;
-    // Levels keeps its channel in the Channel parameter; Levels (Individual Controls) shows
-    // every channel and the popup only picks the histogram.
-    let ch = if effect == "ec.color.levelsic" {
-        app.ui.fx_levels_channel.get(&euid).copied().unwrap_or(0).min(4)
-    } else {
-        g.get("channel").map(|pr| ectx.value(layer, pr).as_enum() as usize).unwrap_or(0).min(4)
-    };
-    if effect == "ec.color.levelsic" {
-        let names: [&str; 5] = [crate::i18n::tr("RGB"), crate::i18n::tr("Red"), crate::i18n::tr("Green"), crate::i18n::tr("Blue"), crate::i18n::tr("Alpha")];
-        if let Some(n) =
-            channel_popup(app, ui, p, x0, cy, ch, &names, egui::Id::unique(("ec-lch", euid)), &format!("effectControls.effect.{euid}.levels.channel"))
-        {
-            app.ui.fx_levels_channel.insert(euid, n);
-        }
-    } else {
-        p.text(pos2(x0, cy), Align2::LEFT_CENTER, crate::i18n::tr("Histogram"), Tokens::ui(12.0), t.text_dim);
-    }
-    let w = (r.width() - 72.0).clamp(120.0, 256.0);
-    let hr = Rect::from_min_size(pos2(x0 + 8.0, r.min.y + 34.0), vec2(w, 80.0));
-    match frame_histogram(app, ui.ctx()) {
-        // Channel 0 (RGB) shows luminance; the others their own channel.
-        Some(h) => fw::draw_histogram(p, hr, &h[ch], channel_color(ch)),
-        None => {
-            p.rect_filled(hr, 0.0, Color32::from_rgb(0x1c, 0x1c, 0x1c));
-        }
-    }
-    app.auto.add(&format!("effectControls.effect.{euid}.levels.histogram"), hr, "Histogram");
-    let ids = levels_ids(effect, ch);
-    let val = |id: &str| g.prop(id).map(|pr| ectx.value(layer, pr).as_f64()).unwrap_or(0.0);
-    let (ib, iw, gm, ob, ow) = (val(&ids[0]), val(&ids[1]), val(&ids[2]), val(&ids[3]), val(&ids[4]));
-    let mut set = |ui: &egui::Ui, id: &str, v: f64, started: bool| {
-        if let Some(pr) = g.prop(id) {
-            let key = gesture_key(ui, egui::Id::unique(("ec-lv", euid, id)), started);
-            actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": pr.uid, "value": v, "merge": key})));
-        }
-    };
-    let track = Rect::from_min_size(pos2(hr.min.x, hr.max.y + 1.0), vec2(w, 10.0));
-    let started = |ui: &egui::Ui| ui.input(|i| i.pointer.any_pressed());
-    let (r0, nv) = fw::level_handle(ui, track, ib, Color32::BLACK, egui::Id::unique(("ec-lib", euid, ch)), &t);
-    app.auto.add(&format!("effectControls.effect.{euid}.levels.inBlack"), r0, "Input Black");
-    if let Some(v) = nv {
-        set(ui, &ids[0], v.min(iw - 0.005), started(ui));
-    }
-    let gx = fw::gamma_handle(ib, iw, gm);
-    let (r1, nv) = fw::level_handle(ui, track, gx, Color32::from_gray(128), egui::Id::unique(("ec-lg", euid, ch)), &t);
-    app.auto.add(&format!("effectControls.effect.{euid}.levels.gamma"), r1, "Gamma");
-    if let Some(v) = nv {
-        set(ui, &ids[2], (fw::gamma_from_handle(ib, iw, v) * 100.0).round() / 100.0, started(ui));
-    }
-    let (r2, nv) = fw::level_handle(ui, track, iw, Color32::WHITE, egui::Id::unique(("ec-liw", euid, ch)), &t);
-    app.auto.add(&format!("effectControls.effect.{euid}.levels.inWhite"), r2, "Input White");
-    if let Some(v) = nv {
-        set(ui, &ids[1], v.max(ib + 0.005), started(ui));
-    }
-    // Output: a black→white bar with its two triangles.
-    let bar = Rect::from_min_size(pos2(hr.min.x, track.max.y + 10.0), vec2(w, 9.0));
-    let n = 32;
-    for k in 0..n {
-        let v = (k as f32 / (n - 1) as f32 * 255.0) as u8;
-        let x0 = bar.min.x + bar.width() * k as f32 / n as f32;
-        let x1 = bar.min.x + bar.width() * (k + 1) as f32 / n as f32;
-        p.rect_filled(Rect::from_min_max(pos2(x0, bar.min.y), pos2(x1, bar.max.y)), 0.0, Color32::from_gray(v));
-    }
-    let otrack = Rect::from_min_size(pos2(bar.min.x, bar.max.y + 1.0), vec2(w, 10.0));
-    let (r3, nv) = fw::level_handle(ui, otrack, ob, Color32::BLACK, egui::Id::unique(("ec-lob", euid, ch)), &t);
-    app.auto.add(&format!("effectControls.effect.{euid}.levels.outBlack"), r3, "Output Black");
-    if let Some(v) = nv {
-        set(ui, &ids[3], v, started(ui));
-    }
-    let (r4, nv) = fw::level_handle(ui, otrack, ow, Color32::WHITE, egui::Id::unique(("ec-low", euid, ch)), &t);
-    app.auto.add(&format!("effectControls.effect.{euid}.levels.outWhite"), r4, "Output White");
-    if let Some(v) = nv {
-        set(ui, &ids[4], v, started(ui));
-    }
-}
-
-/// Auto Levels / Auto Contrast / Auto Color: the histogram they work from.
-fn histogram_only(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, g: &PropGroup, r: Rect) {
-    let t = app.tokens;
-    let x0 = r.min.x + 30.0;
-    p.text(pos2(x0, r.min.y + 12.0), Align2::LEFT_CENTER, crate::i18n::tr("Histogram"), Tokens::ui(12.0), t.text_dim);
-    let w = (r.width() - 72.0).clamp(120.0, 256.0);
-    let hr = Rect::from_min_size(pos2(x0 + 8.0, r.min.y + 24.0), vec2(w, 80.0));
-    match frame_histogram(app, ui.ctx()) {
-        Some(h) => {
-            fw::draw_histogram(p, hr, &h[1], channel_color(1).gamma_multiply(0.6));
-            fw::draw_histogram_overlay(p, hr, &h[2], channel_color(2).gamma_multiply(0.6));
-            fw::draw_histogram_overlay(p, hr, &h[3], channel_color(3).gamma_multiply(0.6));
-        }
-        None => {
-            p.rect_filled(hr, 0.0, Color32::from_rgb(0x1c, 0x1c, 0x1c));
-        }
-    }
-    app.auto.add(&format!("effectControls.effect.{}.histogram", g.uid), hr, "Histogram");
-}
-
-// ---------------------------------------------------------------------------------------------
-
-/// Open the rename field on effect `uid` (Enter with the effect selected), name selected.
-pub fn start_rename(ctx: &egui::Context, uid: u64, name: &str) {
-    let id = egui::Id::unique(("ec-rename", uid));
-    ctx.data_mut(|d| d.insert_temp(id, name.to_string()));
-    ctx.data_mut(|d| d.insert_temp(id.with("select"), true));
-    ctx.memory_mut(|m| m.request_focus(id.with("field")));
-}
-
-/// The Effect Controls panel for the selected layer: a header with the comp and layer names, then
-/// one header per effect (Fx toggle, twirl, rename, Reset, About, label bar, reorder drag and its
-/// right-click menu) followed by that effect's custom editor and its property rows. Dragging
-/// effects or presets onto the panel applies them; a right-click on empty space opens the Effect
-/// menu. The rows read from a snapshot of the project, and every edit is queued and run through
-/// [`crate::menus::invoke`], with failures reported in `app.ui.status`.
-pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
-    let t = app.tokens;
-    let p = ui.painter().with_clip_rect(rect);
-    let ctx = ui.ctx().clone();
-    let Some(layer) = selected_layer(app) else {
-        p.text(rect.center(), Align2::CENTER_CENTER, crate::i18n::tr("Select a layer to see its effects"), Tokens::ui(12.0), t.text_faint);
-        return;
-    };
-    let Some(cid) = app.session.active_comp_id() else { return };
-    let comp = app.session.project.comp_arc(cid).unwrap_or_else(|| effectcraft_engine::project::Comp::new(1, 1, Default::default(), Default::default()).into());
-    let comp_name = app.session.project.item(cid).map(|i| i.name.clone()).unwrap_or_default();
-    let snap_project = app.session.project.clone();
-    let snap_expr = app.session.expr.clone();
-    let ectx = EvalCtx { project: &snap_project, comp_id: cid, comp: &comp, time: app.session.time(), expr: snap_expr.as_deref(), footage: None };
-    let hdr = Rect::from_min_size(rect.min, vec2(rect.width(), 24.0));
-    p.text(pos2(hdr.min.x + 10.0, hdr.center().y), Align2::LEFT_CENTER, format!("{} • {}", comp_name, layer.name), Tokens::ui(11.5), t.text_dim);
-    p.line_segment([hdr.left_bottom(), hdr.right_bottom()], Stroke::new(1.0, t.separator));
-    let body = Rect::from_min_max(pos2(rect.min.x, hdr.max.y), rect.max);
-    let scroll = widgets::PanelScroll::begin(ui, egui::Id::unique("ec-scroll"), body);
-    let mut y = body.min.y + 4.0 - scroll.offset;
-    let mut actions: Actions = vec![];
-    let bp = p.with_clip_rect(body);
-    // Rows scroll under the header: clip their widgets (and hit tests) to the body.
-    let panel_clip = ui.clip_rect();
-    ui.set_clip_rect(body.intersect(panel_clip));
-    let fx: Vec<PropGroup> = layer.effects().map(|f| f.groups().cloned().collect()).unwrap_or_default();
-    if fx.is_empty() {
-        bp.text(
-            pos2(body.center().x, body.min.y + 40.0),
-            Align2::CENTER_CENTER,
-            "No effects. Drag one from Effects & Presets.",
-            Tokens::ui(12.0),
-            t.text_faint,
-        );
-    }
-    // Clicking empty space deselects the effects.
-    let bg = ui.interact(body, egui::Id::unique("ec-bg"), Sense::click());
-    if bg.clicked() {
-        app.session.state.selected_props.retain(|(l, u)| !(*l == layer.id && fx.iter().any(|g| effect_active(g, layer.id, &[(*l, *u)]))));
-    }
-    let has_clip = !app.session.state.effect_clipboard.is_empty();
-    let drag_id = egui::Id::unique("ec-drag-effect");
-    let dragging: Option<u64> = ctx.data(|d| d.get_temp(drag_id));
-    // Header tops, for drag-to-reorder.
-    let mut tops: Vec<(u64, f32)> = vec![];
-    for (fi, g) in fx.iter().enumerate() {
-        let GroupKind::Effect { effect } = &g.kind else { continue };
-        // The header draws the effect's name in the interface language; the automation labels
-        // below keep the property tree's name, which is the registry's English name (#821).
-        let shown = crate::i18n::effects::group(effect, &g.name);
-        let r = Rect::from_min_size(pos2(body.min.x, y), vec2(body.width(), ROW + 2.0));
-        tops.push((g.uid, r.min.y));
-        y += ROW + 2.0;
-        let open = !app.ui.fx_closed.contains(&g.uid);
-        let selected = app.session.state.selected_props.iter().any(|(l, u)| *l == layer.id && *u == g.uid);
-        let active = effect_active(g, layer.id, &app.session.state.selected_props);
-        bp.rect_filled(r, 0.0, if active { t.fx_header_active } else { t.fx_header });
-        // The effect's colour label (26.5): a bar on the header's left edge.
-        if let Some(lab) = g.label.filter(|l| *l != effectcraft_engine::color::Label::None) {
-            let [lr, lg, lb] = app.session.prefs.label_rgb(lab);
-            bp.rect_filled(Rect::from_min_size(r.min, vec2(4.0, r.height())), 0.0, Color32::from_rgb(lr, lg, lb));
-            app.auto.add(
-                &format!("effectControls.effect.{}.label", g.uid),
-                Rect::from_min_size(r.min, vec2(4.0, r.height())),
-                &app.session.prefs.label_name(lab),
-            );
-        }
-        let fxr = Rect::from_center_size(pos2(r.min.x + 14.0, r.center().y), vec2(16.0, 16.0));
-        if widgets::icon_toggle(ui, fxr, Icon::Fx, g.enabled, &t, egui::Id::unique(("ec-fx", g.uid)), Sense::click()).clicked() {
-            actions.push(("effect.toggle".into(), json!({"layer": layer.id.0, "effect": g.uid})));
-        }
-        app.auto.add(&format!("effectControls.effect.{}.fx", g.uid), fxr, &g.name);
-        let tw = Rect::from_center_size(pos2(r.min.x + 32.0, r.center().y), vec2(12.0, 12.0));
-        if widgets::twirl(ui, tw, open, egui::Id::unique(("ec-tw", g.uid)), &t).clicked() {
-            toggle_closed(app, g, open, ui.input(|i| i.modifiers.alt || i.modifiers.command));
-        }
-        app.auto.add(&format!("effectControls.effect.{}.twirl", g.uid), tw, &g.name);
-        let rename_id = egui::Id::unique(("ec-rename", g.uid));
-        let editing: Option<String> = ctx.data(|d| d.get_temp(rename_id));
-        let reset = Rect::from_min_size(pos2(r.max.x - 96.0, r.center().y - 9.0), vec2(40.0, 18.0));
-        if let Some(mut value) = editing.as_ref().cloned() {
-            let name_rect = Rect::from_min_max(pos2(tw.max.x + 6.0, r.min.y + 2.0), pos2(reset.min.x - 6.0, r.max.y - 2.0));
-            let response = ui.put(name_rect, egui::TextEdit::singleline(&mut value).id(rename_id.with("field")).font(Tokens::semibold(12.0)));
-            // Focus the field the frame it first exists: focusing an id not yet on screen leaves
-            // the accessibility tree with a focus it doesn't contain.
-            if ctx.data_mut(|d| d.remove_temp::<bool>(rename_id.with("start"))).is_some() {
-                crate::widgets::select_all(&ctx, response.id, &value);
-                response.request_focus();
-            }
-            app.auto.add(&format!("effectControls.effect.{}.nameEdit", g.uid), name_rect, "Effect name");
-            if ctx.data_mut(|d| d.remove_temp::<bool>(rename_id.with("select"))).unwrap_or(false) {
-                widgets::select_all(&ctx, response.id, &value);
-            }
-            // Escape cancels. egui drops the field's focus on Escape in the same frame, so the
-            // key is checked on the focus being lost as well as held.
-            let escape = (response.has_focus() || response.lost_focus()) && ui.input(|i| i.key_pressed(egui::Key::Escape));
-            let commit = response.lost_focus() || (response.has_focus() && ui.input(|i| i.key_pressed(egui::Key::Enter)));
-            if escape || commit {
-                ctx.data_mut(|d| d.remove::<String>(rename_id));
-                // The field opens with the drawn name, so committing it unchanged is not a rename.
-                if !escape && !value.trim().is_empty() && value != shown {
-                    actions.push(("prop.renameGroup".into(), json!({"layer": layer.id.0, "prop": g.uid, "name": value})));
-                }
-            } else {
-                ctx.data_mut(|d| d.insert_temp(rename_id, value));
-            }
-        } else {
-            let name = bp.text(pos2(tw.max.x + 6.0, r.center().y), Align2::LEFT_CENTER, &shown, Tokens::semibold(12.0), t.text);
-            app.auto.add(&format!("effectControls.effect.{}.name", g.uid), name, &g.name);
-        }
-        let rresp = ui.interact(reset, egui::Id::unique(("ec-reset", g.uid)), Sense::click());
-        bp.text(reset.center(), Align2::CENTER_CENTER, crate::i18n::tr("Reset"), Tokens::ui(11.5), if rresp.hovered() { t.hot_text } else { t.text_dim });
-        app.auto.add(&format!("effectControls.effect.{}.reset", g.uid), reset, "Reset");
-        if rresp.clicked() {
-            actions.push(("effect.reset".into(), json!({"layer": layer.id.0, "effect": g.uid})));
-        }
-        // About…: the effect's name and category (AE's About dialog).
-        let about = Rect::from_min_size(pos2(r.max.x - 50.0, r.center().y - 9.0), vec2(44.0, 18.0));
-        let aresp = ui.interact(about, egui::Id::unique(("ec-about", g.uid)), Sense::click());
-        bp.text(about.center(), Align2::CENTER_CENTER, crate::i18n::tr("About..."), Tokens::ui(11.5), if aresp.hovered() { t.hot_text } else { t.text_dim });
-        app.auto.add(&format!("effectControls.effect.{}.about", g.uid), about, "About");
-        let apop = egui::Id::unique(("ec-about-pop", g.uid));
-        if aresp.clicked() {
-            widgets::open_popup(ui, apop);
-        }
-        if let Some(spec) = effectcraft_engine::effects::find(effect) {
-            let lines = vec![
-                crate::i18n::effects::name(spec.id, spec.name),
-                format!("Category: {}", crate::i18n::effects::category(spec.category)),
-                "EffectCraft built-in effect (MIT OR Apache-2.0)".to_string(),
-            ];
-            let _ = widgets::popup_menu(ui, apop, about.left_bottom(), &lines, None);
-        }
-        let hresp = ui.interact(
-            Rect::from_min_max(pos2(tw.max.x, r.min.y), pos2(reset.min.x - 4.0, r.max.y)),
-            egui::Id::unique(("ec-hdr", g.uid)),
-            if editing.is_some() { Sense::hover() } else { Sense::click_and_drag() },
-        );
-        if hresp.double_clicked() {
-            ctx.data_mut(|d| d.insert_temp(rename_id, shown.clone()));
-            ctx.data_mut(|d| d.insert_temp(rename_id.with("start"), true));
-        }
-        hresp.widget_info(|| egui::WidgetInfo::selected(egui::Role::Button, true, active, &shown));
-        app.auto.add(&format!("effectControls.effect.{}", g.uid), r, &g.name);
-        if hresp.clicked() || hresp.drag_started() || hresp.secondary_clicked() {
-            let add = ui.input(|i| i.modifiers.shift || i.modifiers.command);
-            if add && hresp.clicked() {
-                if selected {
-                    app.session.state.selected_props.retain(|(l, u)| !(*l == layer.id && *u == g.uid));
-                } else {
-                    app.session.state.selected_props.push((layer.id, g.uid));
-                }
-            } else if !selected || hresp.clicked() {
-                app.session.state.selected_props = vec![(layer.id, g.uid)];
-            }
-        }
-        if hresp.drag_started() {
-            ctx.data_mut(|d| d.insert_temp(drag_id, g.uid));
-        }
-        crate::widgets::context_menu(&hresp, |ui| {
-            let lid = layer.id.0;
-            let mut picked_label: Option<usize> = None;
-            let mut item = |ui: &mut egui::Ui, label: &str, enabled: bool, cmd: &str, params: serde_json::Value| {
-                if ui.add_enabled(enabled, egui::Button::new(crate::i18n::context_item(cmd, &params, label))).clicked() {
-                    actions.push((cmd.into(), params));
-                    ui.close();
-                }
-            };
-            item(ui, "Copy", true, "effect.copy", json!({"layer": lid, "effect": g.uid}));
-            item(ui, "Paste", has_clip, "effect.paste", json!({"layers": [lid]}));
-            item(ui, "Duplicate", true, "effect.duplicate", json!({"layer": lid, "effect": g.uid}));
-            if ui.button(crate::i18n::tr("Rename")).clicked() {
-                ctx.data_mut(|d| d.insert_temp(rename_id, shown.clone()));
-                ctx.data_mut(|d| d.insert_temp(rename_id.with("start"), true));
-                ui.close();
-            }
-            ui.separator();
-            ui.menu_button(crate::i18n::tr("Label"), |ui| {
-                let cur = g.label.unwrap_or(effectcraft_engine::color::Label::None);
-                for (i, l) in effectcraft_engine::color::Label::ALL.into_iter().enumerate() {
-                    if widgets::label_entry(ui, l, &app.session.prefs.label_name(l), l == cur, &t).clicked() {
-                        picked_label = Some(i);
-                        ui.close();
-                    }
-                }
-            });
-            item(ui, "Reset", true, "effect.reset", json!({"layer": lid, "effect": g.uid}));
-            item(ui, "Remove", true, "effect.remove", json!({"layer": lid, "effect": g.uid}));
-            ui.separator();
-            item(ui, "Move Up", fi > 0, "effect.reorder", json!({"layer": lid, "effect": g.uid, "index": fi.max(1)}));
-            item(ui, "Move Down", fi + 1 < fx.len(), "effect.reorder", json!({"layer": lid, "effect": g.uid, "index": fi + 2}));
-            if let Some(i) = picked_label {
-                actions.push(("effect.setLabel".into(), json!({"layer": lid, "effect": g.uid, "label": i})));
-            }
-        });
-        // What the effect can't render as asked (an OCIO config it can't read, transforms it
-        // passes through), under its name.
-        if let Some(w) = effectcraft_engine::effects::warning(g, &mut |pr| ectx.value(&layer, pr)) {
-            let galley = bp.layout(format!("⚠ {w}"), Tokens::ui(11.0), t.warning, (body.width() - 20.0).max(60.0));
-            let wr = Rect::from_min_size(pos2(body.min.x + 10.0, y + 3.0), galley.size());
-            bp.galley(wr.min, galley, t.warning);
-            app.auto.add(&format!("effectControls.effect.{}.warning", g.uid), wr, &w);
-            y += wr.height() + 6.0;
-        }
-        if open {
-            let eh = editor_height(effect, g, body.width());
-            if eh > 0.0 {
-                let er = Rect::from_min_size(pos2(body.min.x, y), vec2(body.width(), eh));
-                y += eh;
-                if er.max.y >= body.min.y && er.min.y <= body.max.y {
-                    // Curves, Levels and other custom editors do not use prop_row.
-                    // Clicking their controls must activate the owner as well.
-                    if ui.input(|i| i.pointer.primary_pressed()) && ui.rect_contains_pointer(er) {
-                        actions.push(("prop.select".into(), json!({"layer":layer.id.0,"prop":g.uid})));
-                    }
-                    match effect.as_str() {
-                        "ec.color.curves" => curves_editor(app, ui, &bp, &layer, g, &ectx, er, &mut actions),
-                        effectcraft_engine::effects::warp_stab::ID => warp_editor(app, ui, &bp, &layer, g, er, &mut actions),
-                        effectcraft_engine::effects::camera_tracker::ID => super::camera_tracker_ui::editor(app, ui, &bp, &layer, g, er, &mut actions),
-                        effectcraft_engine::effects::roto::ID => roto_editor(app, ui, &bp, &layer, g, er, &mut actions),
-                        effectcraft_engine::effects::object_matte::ID => object_matte_editor(app, ui, &bp, &layer, g, er, &mut actions),
-                        "ec.color.levels" | "ec.color.levelsic" => levels_editor(app, ui, &bp, &layer, g, effect, &ectx, er, &mut actions),
-                        super::fx_editors::GLOW | super::fx_editors::RESHAPE | super::fx_editors::EXTRACTOR => {
-                            super::fx_editors::header_editor(app, ui, &bp, &layer, g, effect, &ectx, er, &mut actions)
-                        }
-                        _ => histogram_only(app, ui, &bp, g, er),
-                    }
-                }
-            }
-            let scope = FxScope { effect: effect.as_str(), root: g, path: String::new() };
-            group_rows(app, ui, &bp, &layer, g, &ectx, body, &mut y, 0, &scope, &mut actions);
-            if effect == "ec.color.tint" {
-                let r = Rect::from_min_size(pos2(body.min.x + PARAM_NAME_X, y + 2.0), vec2(120.0, ROW));
-                let label = crate::i18n::tr("Swap Colors");
-                let resp = widgets::text_button(ui, r, label, false, &t, egui::Id::unique(("ec-tint-swap", g.uid)));
-                app.auto.add_response(&format!("effectControls.effect.{}.swapColors", g.uid), &resp, label);
-                if resp.clicked() {
-                    actions.push(("prop.select".into(), json!({"layer": layer.id.0, "prop": g.uid})));
-                    actions.push(("effect.swapTintColors".into(), json!({"layer": layer.id.0, "effect": g.uid})));
-                }
-                y += ROW + 4.0;
-            }
-        }
-        y += 4.0;
-    }
-    // Drag an effect header to reorder: insertion line between headers.
-    if let Some(du) = dragging {
-        if let Some(pos) = ctx.pointer_interact_pos() {
-            let slot = tops.iter().position(|(_, ty)| pos.y < *ty + (ROW + 2.0) / 2.0).unwrap_or(tops.len());
-            let ly = tops.get(slot).map(|(_, ty)| *ty).unwrap_or(y - 4.0);
-            bp.line_segment([pos2(body.min.x + 4.0, ly), pos2(body.max.x - 4.0, ly)], Stroke::new(2.0, t.accent));
-            if ctx.input(|i| i.pointer.any_released()) {
-                if let Some(from) = tops.iter().position(|(u, _)| *u == du) {
-                    let to = if slot > from { slot - 1 } else { slot };
-                    if to != from {
-                        actions.push(("effect.reorder".into(), json!({"layer": layer.id.0, "effect": du, "index": to + 1})));
-                    }
-                }
-                ctx.data_mut(|d| d.remove::<u64>(drag_id));
-            }
-        }
-        if !ctx.input(|i| i.pointer.any_down()) {
-            ctx.data_mut(|d| d.remove::<u64>(drag_id));
-        }
-    }
-    // Right-click anywhere a control has no menu of its own: the Effect menu, which applies to
-    // the selected layers (After Effects). Drawn after the rows, whose menus open first.
-    let menu_id = bg.id.with("effect-menu");
-    let open = ui.input(|i| i.pointer.secondary_clicked())
-        && ui.rect_contains_pointer(body)
-        && (!egui::Popup::is_any_open(&ctx) || egui::Popup::is_id_open(&ctx, menu_id));
-    egui::Popup::context_menu(&bg).style(crate::widgets::menu_style).id(menu_id).open_memory(open.then_some(egui::SetOpenCommand::Bool(true))).show(|ui| {
-        ui.set_min_width(200.0);
-        actions.extend(crate::menus::menu_contents(app, ui, "Effect"));
-    });
-    ui.set_clip_rect(panel_clip);
-    let content_h = y + scroll.offset - body.min.y;
-    scroll.end(ui, &mut app.auto, "effectControls.scroll", content_h, &t);
-    // Drop effects and animation presets here.
-    if let Some(payload) = egui::DragAndDrop::payload::<crate::panels::DragPayload>(&ctx)
-        && ui.rect_contains_pointer(rect)
-        && let Some((id, params)) = match payload.as_ref() {
-            crate::panels::DragPayload::Effect(e) => Some(("effect.apply", json!({"effect": e, "layers": [layer.id.0]}))),
-            crate::panels::DragPayload::Preset { preset, .. } => Some(preset.apply_to(layer.id.0)),
-            _ => None,
-        }
-    {
-        p.rect_stroke(rect, 0.0, Stroke::new(2.0, t.accent), egui::StrokeKind::Inside);
-        if ctx.input(|i| i.pointer.any_released()) {
-            actions.push((id.into(), params));
-            egui::DragAndDrop::clear_payload(&ctx);
-        }
-    }
-    if ui.input(|i| i.pointer.primary_down()) && actions.iter().any(|(id, _)| id == "prop.set") {
-        app.ui.viewer.property_interacting = true;
-        ctx.request_repaint();
-    }
-    for (id, params) in actions {
-        if let Err(e) = crate::menus::invoke(app, &ctx, &id, params) {
-            app.ui.status = e;
-        }
-    }
-}
-
-// ---------------------------------------------------------------------------------------------
-// Viewer hook
-
-/// Collect point controls through visible parameter groups. Hidden optional slots do not
-/// leave stray viewport handles. The depth cap also bounds malformed project trees.
-fn visible_points<'a>(g: &'a PropGroup, scope: &FxScope<'_>, layer: &Layer, ectx: &EvalCtx, depth: usize, out: &mut Vec<&'a Property>) {
-    if depth > 16 {
-        return;
-    }
-    for node in &g.children {
-        match node {
-            Node::Prop(p) if matches!(p.ui, ParamUi::Point) && scope.shown(layer, ectx, &p.match_id) => out.push(p),
-            Node::Group(child) if child.enabled && scope.shown(layer, ectx, &child.match_id) => {
-                visible_points(child, &scope.sub(&child.match_id), layer, ectx, depth + 1, out)
-            }
-            _ => {}
-        }
-    }
-}
-
-/// Effect Controls' part of the Composition viewer, called by the viewer after its own
-/// interaction (so these controls sit on top):
-///
-/// - while a crosshair pick is armed, its handle previews the cursor position without editing
-///   the property; the next click sets the point in layer space, and Esc cancels;
-/// - an eyedropper pick samples the frame's colour on click;
-/// - otherwise, the point parameters of the selected effects are drawn as draggable ⊕ controls.
-///
-/// `l2c` is the viewer's layer→comp matrix (it knows the 3D view).
-pub fn viewer_hook(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    painter: &egui::Painter,
-    map: &super::viewer::ViewerMap,
-    ectx: &EvalCtx,
-    l2c: &dyn Fn(&EvalCtx, &Layer) -> Mat3,
-) {
-    let t = app.tokens;
-    let ctx = ui.ctx().clone();
-    let mut actions: Actions = vec![];
-    let mut point_preview = None;
-    if let Some(pick) = app.ui.fx_pick.clone() {
-        let Some(layer) = ectx.comp.layer(effectcraft_engine::project::LayerId(pick.layer)).cloned() else {
-            app.ui.fx_pick = None;
-            return;
-        };
-        // Keyers pick from their input (the shown frame is already keyed): `effect.pickColor`.
-        let keyer = (pick.kind == "color")
-            .then(|| layer.effects()?.groups().find(|g| g.find(pick.prop).is_some()))
-            .flatten()
-            .filter(|g| effectcraft_engine::effects::find(&g.match_id).is_some_and(|s| s.category == "Keying"))
-            .map(|g| g.uid);
-        if pick.kind == "color" && keyer.is_none() {
-            // GPU frames: read the shown frame back for sampling.
-            app.viewer_pixels();
-        }
-        let resp = ui.interact(map.area, egui::Id::unique("viewer-fx-pick"), Sense::click());
-        app.auto.add("viewer.fxPick", map.area, &pick.name);
-        let hint = if pick.kind == "point" { format!("Click to set {}", pick.name) } else { format!("Click to sample {}", pick.name) };
-        let chip = Rect::from_min_size(map.area.min + vec2(10.0, 10.0), vec2(220.0, 22.0));
-        painter.rect_filled(chip, 11.0, Color32::from_black_alpha(180));
-        painter.text(chip.center(), Align2::CENTER_CENTER, hint, Tokens::ui(11.5), t.text);
-        if let Some(hp) = resp.hover_pos() {
-            ctx.set_cursor_icon(egui::CursorIcon::Crosshair);
-            let c = map.to_comp(hp);
-            app.pointer_comp = Some([c[0] as f32, c[1] as f32]);
-            if pick.kind == "point" && fw::comp_to_layer(&l2c(ectx, &layer), c).is_some() {
-                point_preview = Some(hp);
-            }
-            if pick.kind == "color"
-                && keyer.is_none()
-                && let Some(img) = &app.viewer_image
-                && let Some(s) = fw::sample_frame(img, super::viewer_tools::shown_region(&ctx, map.comp), c)
-            {
-                let sw = Rect::from_min_size(hp + vec2(14.0, 14.0), vec2(26.0, 18.0));
-                painter.rect_filled(sw, 2.0, Color32::from_rgb((s[0] * 255.0) as u8, (s[1] * 255.0) as u8, (s[2] * 255.0) as u8));
-                painter.rect_stroke(sw, 2.0, Stroke::new(1.0, Color32::WHITE), egui::StrokeKind::Outside);
-            }
-        }
-        // No frame to sample yet (it is still rendering, or its readback is pending): the click
-        // leaves the eyedropper armed instead of using it up without a colour.
-        let unsampled = pick.kind == "color" && keyer.is_none() && app.viewer_image.is_none();
-        if resp.clicked()
-            && !unsampled
-            && let Some(pos) = resp.interact_pointer_pos()
-        {
-            let c = map.to_comp(pos);
-            // Effect points and the keyer's input are in effect space.
-            let m = super::viewer::from_effect_space(ectx, &layer, l2c(ectx, &layer));
-            if pick.kind == "point" {
-                if let Some(lp) = fw::comp_to_layer(&m, c) {
-                    actions.push(("prop.set".into(), json!({"layer": pick.layer, "prop": pick.prop, "value": [lp[0], lp[1]]})));
-                }
-            } else if let Some(fx) = keyer {
-                // Ctrl/Cmd+click averages the 5 × 5 pixels around the point.
-                if let Some(lp) = fw::comp_to_layer(&m, c) {
-                    let average = ui.input(|i| i.modifiers.command);
-                    actions.push((
-                        "effect.pickColor".into(),
-                        json!({"layer": pick.layer, "effect": fx, "prop": pick.prop, "x": lp[0], "y": lp[1], "average": average}),
-                    ));
-                }
-            } else if let Some(img) = &app.viewer_image
-                && let Some(s) = fw::sample_frame(img, super::viewer_tools::shown_region(&ctx, map.comp), c)
-            {
-                actions.push(("prop.set".into(), json!({"layer": pick.layer, "prop": pick.prop, "value": [s[0], s[1], s[2], 1.0]})));
-            }
-            app.ui.fx_pick = None;
-            app.ui.status.clear();
-        }
-        if ui.input(|i| i.key_pressed(egui::Key::Escape)) {
-            app.ui.fx_pick = None;
-            app.ui.status.clear();
-        }
-    }
-    if let Some(pick) = app.ui.text_color_pick.clone() {
-        if ectx.comp.layer(effectcraft_engine::project::LayerId(pick.layer)).is_none() {
-            app.ui.text_color_pick = None;
-            app.ui.status.clear();
-        } else {
-            app.viewer_pixels();
-            let resp = ui.interact(map.area, egui::Id::unique("viewer-text-color-pick"), Sense::click());
-            app.auto.add("viewer.textColorPick", map.area, &pick.field);
-            let chip = Rect::from_min_size(map.area.min + vec2(10.0, 10.0), vec2(220.0, 22.0));
-            painter.rect_filled(chip, 11.0, Color32::from_black_alpha(180));
-            painter.text(chip.center(), Align2::CENTER_CENTER, crate::i18n::tr_args("Click to sample text {}", &[&pick.field]), Tokens::ui(11.5), t.text);
-            if let Some(pos) = resp.hover_pos() {
-                ctx.set_cursor_icon(egui::CursorIcon::Crosshair);
-                let c = map.to_comp(pos);
-                app.pointer_comp = Some([c[0] as f32, c[1] as f32]);
-                if let Some(img) = &app.viewer_image
-                    && let Some(s) = fw::sample_frame(img, super::viewer_tools::shown_region(&ctx, map.comp), c)
-                {
-                    let sw = Rect::from_min_size(pos + vec2(14.0, 14.0), vec2(26.0, 18.0));
-                    painter.rect_filled(sw, 2.0, Color32::from_rgb((s[0] * 255.0) as u8, (s[1] * 255.0) as u8, (s[2] * 255.0) as u8));
-                    painter.rect_stroke(sw, 2.0, Stroke::new(1.0, Color32::WHITE), egui::StrokeKind::Outside);
-                }
-            }
-            if resp.clicked()
-                && let Some(pos) = resp.interact_pointer_pos()
-                && let Some(img) = &app.viewer_image
-                && let Some(s) = fw::sample_frame(img, super::viewer_tools::shown_region(&ctx, map.comp), map.to_comp(pos))
-            {
-                let mut params = json!({"layer": pick.layer});
-                params[&pick.field] = json!([s[0], s[1], s[2]]);
-                if let Some(range) = pick.range {
-                    params["range"] = json!(range);
-                }
-                actions.push(("layer.setText".into(), params));
-                app.ui.text_color_pick = None;
-                app.ui.status.clear();
-            }
-            if ui.input(|i| i.key_pressed(egui::Key::Escape)) {
-                app.ui.text_color_pick = None;
-                app.ui.status.clear();
-            }
-        }
-    }
-    let picking = app.ui.fx_pick.is_some() || app.ui.text_color_pick.is_some();
-    let point_pick = app.ui.fx_pick.clone().filter(|p| p.kind == "point");
-    if app.ui.viewer.show_layer_controls || point_pick.is_some() {
-        // ⊕ controls for the point parameters of the selected effects.
-        let mut sel = app.session.state.selected_props.clone();
-        if let Some(pick) = &point_pick {
-            sel.push((effectcraft_engine::project::LayerId(pick.layer), pick.prop));
-        }
-        let selected = app.session.state.selected_layers.clone();
-        for layer in ectx
-            .comp
-            .layers
-            .iter()
-            .filter(|l| (selected.contains(&l.id) || point_pick.as_ref().is_some_and(|p| p.layer == l.id.0)) && l.is_active_at(ectx.time))
-        {
-            let Some(fx) = layer.effects() else { continue };
-            let m = l2c(ectx, layer);
-            // Masks are in layer space, effect points in effect space.
-            let fm = super::viewer::from_effect_space(ectx, layer, m);
-            let picked_prop = point_pick.as_ref().filter(|p| p.layer == layer.id.0).map(|p| p.prop);
-            for g in fx.groups().filter(|g| g.enabled && effect_active(g, layer.id, &sel)) {
-                // Puppet owns its pin handles and hit testing. Generic crosshairs would
-                // overlap the pins and steal their selection/rotation/scale gestures.
-                if matches!(&g.kind, GroupKind::Effect { effect } if effect == effectcraft_engine::effects::puppet::ID) {
-                    continue;
-                }
-                if !picking && app.ui.viewer.show_layer_controls && matches!(&g.kind, GroupKind::Effect { effect } if effect == super::fx_editors::RESHAPE) {
-                    super::fx_editors::reshape_overlay(app, ui, painter, map, ectx, layer, g, &m, &mut actions);
-                }
-                if !picking && app.ui.viewer.show_layer_controls && matches!(&g.kind, GroupKind::Effect { effect } if effect == super::fx_editors::MESH_WARP) {
-                    super::fx_editors::mesh_warp_overlay(app, ui, painter, map, ectx, layer, g, &fm, &mut actions);
-                }
-                let scope = FxScope { effect: &g.match_id, root: g, path: String::new() };
-                let mut pts = Vec::new();
-                visible_points(g, &scope, layer, ectx, 0, &mut pts);
-                // An explicit pick stays visible even when View > Show Layer Controls is off.
-                if !app.ui.viewer.show_layer_controls {
-                    pts.retain(|pr| picked_prop == Some(pr.uid));
-                }
-                let screen: Vec<egui::Pos2> = pts
-                    .iter()
-                    .map(|pr| {
-                        if picked_prop == Some(pr.uid)
-                            && let Some(pos) = point_preview
-                        {
-                            return pos;
-                        }
-                        let v = ectx.value(layer, pr).as_vec2();
-                        map.to_screen(fw::layer_to_comp(&fm, v))
-                    })
-                    .collect();
-                // Gradient Ramp and friends: a guide between start and end points.
-                if screen.len() == 2 && matches!(&g.kind, GroupKind::Effect { effect } if effect.contains("gradient") || effect.contains("ramp")) {
-                    painter.line_segment([screen[0], screen[1]], Stroke::new(1.0, Color32::from_white_alpha(110)));
-                }
-                for (pr, s) in pts.iter().zip(screen) {
-                    let hr = Rect::from_center_size(s, vec2(16.0, 16.0));
-                    let id = egui::Id::unique(("viewer-fx-pt", pr.uid));
-                    // The picker owns the click. Preview handles must not steal it or start a drag.
-                    let resp = (!picking).then(|| ui.interact(hr, id, Sense::drag()));
-                    let col = if picked_prop == Some(pr.uid) || resp.as_ref().is_some_and(|r| r.hovered() || r.dragged()) { t.accent } else { Color32::WHITE };
-                    fw::draw_crosshair(painter, s + vec2(1.0, 1.0), 5.0, Color32::from_black_alpha(160));
-                    fw::draw_crosshair(painter, s, 5.0, col);
-                    app.auto.add(&format!("viewer.effectPoint.{}", pr.uid), hr, &pr.name);
-                    let Some(resp) = resp else { continue };
-                    if resp.hovered() {
-                        ctx.set_cursor_icon(egui::CursorIcon::Move);
-                        resp.clone().on_hover_text(format!("{}: {}", crate::i18n::effects::group(&g.match_id, &g.name), pr.name));
-                    }
-                    if resp.dragged()
-                        && let Some(pos) = resp.interact_pointer_pos()
-                        && let Some(lp) = fw::comp_to_layer(&fm, map.to_comp(pos))
-                    {
-                        let key = gesture_key(ui, id, resp.drag_started());
-                        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": pr.uid, "value": [lp[0], lp[1]], "merge": key})));
-                    }
-                }
-            }
-        }
-    }
-    for (id, params) in actions {
-        if let Err(e) = crate::menus::invoke(app, &ctx, &id, params) {
-            app.ui.status = e;
-        }
-    }
-}
+pub(crate) use common::gesture_key;
+pub use common::{choose_files_after_apply, reveal_applied};
+pub use panel::{show, start_rename};
+pub(crate) use rows::toggle_pick;
+pub use viewer::viewer_hook;
diff --git a/crates/ui-egui/src/panels/effect_controls/common.rs b/crates/ui-egui/src/panels/effect_controls/common.rs
new file mode 100644
index 000000000..ab46a07ac
--- /dev/null
+++ b/crates/ui-egui/src/panels/effect_controls/common.rs
@@ -0,0 +1,109 @@
+use super::{EffectcraftApp, Layer, Node, ParamUi, PropGroup, Value, json};
+
+pub(super) type Actions = Vec<(String, serde_json::Value)>;
+
+pub(super) const ROW: f32 = 20.0;
+
+pub(super) const DIAL_ROW: f32 = 64.0;
+
+// The effect title starts at 44 pt. Each level's names sit one tree step farther in;
+// reserve the same icon gutter for properties and groups so sibling names align.
+pub(super) const PARAM_NAME_X: f32 = 58.0;
+
+pub(super) const TREE_INDENT: f32 = 14.0;
+
+/// Selecting any descendant activates its owning effect without replacing the property
+/// selection used by keyframe editing, copy and delete.
+pub(super) fn effect_active(g: &PropGroup, layer: effectcraft_engine::project::LayerId, selected: &[(effectcraft_engine::project::LayerId, u64)]) -> bool {
+    fn contains(g: &PropGroup, uid: u64, depth: usize) -> bool {
+        if g.uid == uid {
+            return true;
+        }
+        if depth >= 16 {
+            return false;
+        }
+        g.children.iter().any(|n| n.uid() == uid || matches!(n, Node::Group(child) if contains(child, uid, depth + 1)))
+    }
+    selected.iter().any(|(l, uid)| *l == layer && contains(g, *uid, 0))
+}
+
+pub(super) fn selected_layer(app: &EffectcraftApp) -> Option<Layer> {
+    let comp = app.session.active_comp()?;
+    let id = app.session.state.selected_layers.first()?;
+    comp.layer(*id).cloned()
+}
+
+/// An effect was just applied (`effect.apply` / `effect.applyLast` with `params`): Effect
+/// Controls comes up (opened if closed, brought to the front, the focus left where it is) on the
+/// layer the effect went to, with the new effect selected, as in After Effects.
+pub fn reveal_applied(app: &mut EffectcraftApp, params: &serde_json::Value) {
+    // `effect.apply` selects the new effect on (the last of) the layers it went to.
+    let target = app.session.state.selected_props.last().map(|(l, _)| *l);
+    if let Some(l) = target
+        && !app.session.state.selected_layers.contains(&l)
+        && params.get("comp").is_none()
+        && app.session.active_comp().is_some_and(|c| c.layer(l).is_some())
+    {
+        // Show that layer (dropped on an unselected one), keeping the new effect selected.
+        let props = app.session.state.selected_props.clone();
+        match app.session.execute("layer.select", json!({"layers": [l.0]})) {
+            Ok(_) => app.session.state.selected_props = props,
+            Err(e) => app.ui.status = e.to_string(),
+        }
+    }
+    app.raise_panel(crate::dock::PanelKind::EffectControls);
+}
+
+/// After Effects asks for an effect's file as it applies it (Apply Color LUT opens the file
+/// dialog for its LUT). For the instances `effect.apply` made (`applied`, its result), open the
+/// file dialog for their first empty file parameter and set the file on each; cancelling
+/// leaves the effect without one. Does nothing without a file dialog (tests, agents).
+pub fn choose_files_after_apply(app: &mut EffectcraftApp, applied: &serde_json::Value) {
+    let Some(pick) = app.hooks.pick_files.as_ref() else { return };
+    let Some(comp) = app.session.active_comp() else { return };
+    let uids: Vec<u64> = applied.get("effects").and_then(|v| v.as_array()).map(|a| a.iter().filter_map(|v| v.as_u64()).collect()).unwrap_or_default();
+    let mut targets = vec![];
+    let mut filters: Vec<String> = vec![];
+    for uid in uids {
+        for l in &comp.layers {
+            let Some(g) = l.props.find_group(uid) else { continue };
+            let mut found = None;
+            g.walk("", &mut |_, pr| {
+                if found.is_none()
+                    && let ParamUi::File { filters } = &pr.ui
+                    && matches!(&pr.value, Value::Str(s) if s.trim().is_empty())
+                {
+                    found = Some((pr.uid, filters.clone()));
+                }
+            });
+            if let Some((prop, f)) = found {
+                targets.push((l.id.0, prop));
+                filters = f;
+            }
+        }
+    }
+    if targets.is_empty() {
+        return;
+    }
+    let exts: Vec<&str> = filters.iter().map(String::as_str).collect();
+    let Some(path) = pick(&exts).into_iter().next() else { return };
+    for (layer, prop) in targets {
+        if let Err(e) = app.session.execute("prop.set", json!({"layer": layer, "prop": prop, "value": path})) {
+            app.ui.status = e.to_string();
+        }
+    }
+}
+
+/// An undo-merge key for one gesture on `id`: a new key each time a drag starts, so separate
+/// drags are separate undo steps while one drag is one step.
+pub(crate) fn gesture_key(ui: &egui::Ui, id: egui::Id, started: bool) -> String {
+    let kid = id.with("gesture");
+    let n: u64 = if started {
+        let n = ui.data(|d| d.get_temp::<u64>(kid)).unwrap_or(0) + 1;
+        ui.data_mut(|d| d.insert_temp(kid, n));
+        n
+    } else {
+        ui.data(|d| d.get_temp::<u64>(kid)).unwrap_or(0)
+    };
+    format!("{id:?}-{n}")
+}
diff --git a/crates/ui-egui/src/panels/effect_controls/editors.rs b/crates/ui-egui/src/panels/effect_controls/editors.rs
new file mode 100644
index 000000000..c95c90c07
--- /dev/null
+++ b/crates/ui-egui/src/panels/effect_controls/editors.rs
@@ -0,0 +1,380 @@
+use super::common::{Actions, gesture_key};
+use super::{Align2, Color32, EffectcraftApp, EvalCtx, Layer, PropGroup, Rect, Sense, Tokens, Value, fw, json, pos2, vec2, widgets};
+
+/// Warp Stabilizer's Analyze / Cancel buttons and analysis status.
+pub(super) fn warp_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, layer: &Layer, g: &PropGroup, r: Rect, actions: &mut Actions) {
+    let t = app.tokens;
+    let running = app.session.warp_target().is_some_and(|(_, l, u)| l == layer.id && u == g.uid) && app.session.is_warp_analyzing();
+    let busy = app.session.is_warp_analyzing();
+    let b1 = Rect::from_min_size(pos2(r.min.x + 24.0, r.min.y + 4.0), vec2(84.0, 22.0));
+    let b2 = Rect::from_min_size(pos2(b1.max.x + 8.0, b1.min.y), vec2(84.0, 22.0));
+    if widgets::text_button(ui, b1, "Analyze", false, &t, egui::Id::unique(("warp-analyze", g.uid))).clicked() && !busy {
+        actions.push(("warp.analyze".into(), json!({"layer": layer.id.0, "effect": g.uid})));
+    }
+    app.auto.add(&format!("effectControls.warp.{}.analyze", g.uid), b1, "Analyze");
+    if running {
+        if widgets::text_button(ui, b2, "Cancel", false, &t, egui::Id::unique(("warp-cancel", g.uid))).clicked() {
+            actions.push(("warp.cancel".into(), json!({})));
+        }
+        app.auto.add(&format!("effectControls.warp.{}.cancel", g.uid), b2, "Cancel");
+    }
+    let analysed = matches!(g.get(effectcraft_engine::effects::warp_stab::ANALYSIS).map(|p| &p.value), Some(Value::Str(s)) if !s.is_empty());
+    let status = match app.session.warp_progress() {
+        Some(pr) if running => pr.banner(),
+        _ if analysed => "Analysis complete".to_string(),
+        _ if app.session.warp_pending.iter().any(|(_, l, u)| *l == layer.id && *u == g.uid) => "Waiting to analyze".to_string(),
+        _ => "Not analyzed: click Analyze".to_string(),
+    };
+    p.text(pos2(r.min.x + 24.0, r.min.y + 38.0), Align2::LEFT_CENTER, status, Tokens::ui(11.5), t.text_dim);
+}
+
+/// Roto Brush & Refine Edge: Freeze / Unfreeze and Propagate buttons and the segmentation status.
+pub(super) fn roto_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, layer: &Layer, g: &PropGroup, r: Rect, actions: &mut Actions) {
+    use effectcraft_engine::effects::roto as fx;
+    let t = app.tokens;
+    let params = effectcraft_engine::effects::flatten_params(g, &mut |pr| pr.value.clone());
+    let frozen = fx::is_frozen(&params);
+    let d = fx::data(&params);
+    let running = app.session.roto_target().is_some_and(|(_, l, u, _)| l == layer.id && u == g.uid) && app.session.is_roto_running();
+    let b1 = Rect::from_min_size(pos2(r.min.x + 24.0, r.min.y + 4.0), vec2(84.0, 22.0));
+    let b2 = Rect::from_min_size(pos2(b1.max.x + 8.0, b1.min.y), vec2(84.0, 22.0));
+    let label = if frozen { "Unfreeze" } else { "Freeze" };
+    if widgets::text_button(ui, b1, label, frozen, &t, egui::Id::unique(("roto-freeze-ec", g.uid))).clicked() && !running {
+        let id = if frozen { "roto.unfreeze" } else { "roto.freeze" };
+        actions.push((id.into(), json!({"layer": layer.id.0, "effect": g.uid})));
+    }
+    app.auto.add(&format!("effectControls.roto.{}.freeze", g.uid), b1, label);
+    let (l2, id2) = if running { ("Stop", "roto.cancel") } else { ("Propagate", "roto.propagate") };
+    if widgets::text_button(ui, b2, l2, false, &t, egui::Id::unique(("roto-prop-ec", g.uid))).clicked() && !frozen {
+        actions.push((id2.into(), json!({"layer": layer.id.0, "effect": g.uid})));
+    }
+    app.auto.add(&format!("effectControls.roto.{}.propagate", g.uid), b2, l2);
+    let status = match (app.session.roto_progress(), d.base) {
+        (Some(pr), _) if running => pr.banner(),
+        (_, None) => "No strokes: paint with the Roto Brush tool (Alt+W) in the Layer panel".to_string(),
+        (_, Some(b)) => format!("Base frame {b}, span {}–{}{}", d.span[0], d.span[1], if frozen { " (frozen)" } else { "" }),
+    };
+    p.text(pos2(r.min.x + 24.0, r.min.y + 38.0), Align2::LEFT_CENTER, status, Tokens::ui(11.5), t.text_dim);
+}
+
+/// Object Matte: Freeze / Unfreeze and Track / Stop buttons (the background job that computes
+/// the matte over the tracked frames) and its status.
+pub(super) fn object_matte_editor(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    p: &egui::Painter,
+    layer: &Layer,
+    g: &PropGroup,
+    r: Rect,
+    actions: &mut Actions,
+) {
+    use effectcraft_engine::effects::object_matte as om;
+    let t = app.tokens;
+    let params = effectcraft_engine::effects::flatten_params(g, &mut |pr| pr.value.clone());
+    let frozen = om::is_frozen(&params);
+    let mine = app.session.roto_target().is_some_and(|(_, l, u, _)| l == layer.id && u == g.uid);
+    let running = mine && app.session.is_roto_running();
+    let busy = app.session.is_roto_running();
+    let b1 = Rect::from_min_size(pos2(r.min.x + 24.0, r.min.y + 4.0), vec2(84.0, 22.0));
+    let b2 = Rect::from_min_size(pos2(b1.max.x + 8.0, b1.min.y), vec2(84.0, 22.0));
+    let label = if frozen { "Unfreeze" } else { "Freeze" };
+    if widgets::text_button(ui, b1, crate::i18n::tr(label), frozen, &t, egui::Id::unique(("om-freeze-ec", g.uid))).clicked() && !busy {
+        let id = if frozen { "objectMatte.unfreeze" } else { "objectMatte.freeze" };
+        actions.push((id.into(), json!({"layer": layer.id.0, "effect": g.uid})));
+    }
+    app.auto.add(&format!("effectControls.objectMatte.{}.freeze", g.uid), b1, label);
+    let (l2, id2) = if running { ("Stop", "roto.cancel") } else { ("Track", "objectMatte.propagate") };
+    if widgets::text_button(ui, b2, crate::i18n::tr(l2), false, &t, egui::Id::unique(("om-track-ec", g.uid))).clicked() && !frozen && (running || !busy) {
+        actions.push((id2.into(), json!({"layer": layer.id.0, "effect": g.uid})));
+    }
+    app.auto.add(&format!("effectControls.objectMatte.{}.track", g.uid), b2, l2);
+    let base = om::reference_frame(&params);
+    let status = match app.session.roto_progress() {
+        Some(pr) if running => pr.banner(),
+        _ if frozen => format!("Frozen from reference frame {base}"),
+        _ if app.session.roto_pending.iter().any(|(_, l, u)| *l == layer.id && *u == g.uid) => "Waiting to track".to_string(),
+        _ => format!("Reference frame {base}: Track computes the matte ahead of playback"),
+    };
+    p.text(pos2(r.min.x + 24.0, r.min.y + 38.0), Align2::LEFT_CENTER, &status, Tokens::ui(11.5), t.text_dim);
+    app.auto.add(
+        &format!("effectControls.objectMatte.{}.status", g.uid),
+        Rect::from_min_size(pos2(r.min.x + 24.0, r.min.y + 30.0), vec2(r.width() - 24.0, 16.0)),
+        &status,
+    );
+}
+
+// ---------------------------------------------------------------------------------------------
+// Curves / Levels editors
+
+/// Height of the custom editor shown under an effect's header (0 when none).
+pub(super) fn editor_height(effect: &str, g: &PropGroup, width: f32) -> f32 {
+    match effect {
+        crate::panels::fx_editors::GLOW | crate::panels::fx_editors::RESHAPE | crate::panels::fx_editors::EXTRACTOR => {
+            crate::panels::fx_editors::header_height(effect, g, width)
+        }
+        "ec.color.curves" => 34.0 + curves_size(width) + 26.0,
+        effectcraft_engine::effects::warp_stab::ID => 50.0,
+        effectcraft_engine::effects::camera_tracker::ID => crate::panels::camera_tracker_ui::EDITOR_HEIGHT,
+        effectcraft_engine::effects::roto::ID | effectcraft_engine::effects::object_matte::ID => 50.0,
+        "ec.color.levels" | "ec.color.levelsic" => 34.0 + 80.0 + 58.0,
+        "ec.color.autolevels" | "ec.color.autocontrast" | "ec.color.autocolor" => 24.0 + 80.0 + 12.0,
+        _ => 0.0,
+    }
+}
+
+fn curves_size(width: f32) -> f32 {
+    (width - 72.0).clamp(120.0, 256.0)
+}
+
+/// Cached histogram of the displayed frame (recomputed when the frame changes).
+fn frame_histogram(app: &mut EffectcraftApp, ctx: &egui::Context) -> Option<std::sync::Arc<[[u32; 256]; 5]>> {
+    let img = app.viewer_pixels()?;
+    let key = std::sync::Arc::as_ptr(&img) as usize;
+    let id = egui::Id::unique("ec-histogram");
+    if let Some((k, h)) = ctx.data(|d| d.get_temp::<(usize, std::sync::Arc<[[u32; 256]; 5]>)>(id))
+        && k == key
+    {
+        return Some(h);
+    }
+    let h = std::sync::Arc::new(fw::histogram(&img));
+    ctx.data_mut(|d| d.insert_temp(id, (key, h.clone())));
+    Some(h)
+}
+
+fn channel_color(ch: usize) -> Color32 {
+    match ch {
+        1 => Color32::from_rgb(0xe0, 0x50, 0x50),
+        2 => Color32::from_rgb(0x50, 0xc8, 0x60),
+        3 => Color32::from_rgb(0x50, 0x80, 0xf0),
+        4 => Color32::from_gray(0x90),
+        _ => Color32::from_gray(0xb8),
+    }
+}
+
+/// A "Channel: [RGB ▾]" popup; returns the chosen channel.
+#[allow(clippy::too_many_arguments)]
+fn channel_popup(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    p: &egui::Painter,
+    x: f32,
+    cy: f32,
+    cur: usize,
+    names: &[&str],
+    id: egui::Id,
+    auto: &str,
+) -> Option<usize> {
+    let t = app.tokens;
+    p.text(pos2(x, cy), Align2::LEFT_CENTER, crate::i18n::tr("Channel:"), Tokens::ui(12.0), t.text_dim);
+    let dr = Rect::from_min_size(pos2(x + 58.0, cy - 9.0), vec2(80.0, 18.0));
+    let pop = id.with("pop");
+    if widgets::dropdown(ui, dr, names.get(cur).copied().unwrap_or(""), &t, id).clicked() {
+        widgets::open_popup(ui, pop);
+    }
+    app.auto.add(auto, dr, "Channel");
+    let opts: Vec<String> = names.iter().map(|s| s.to_string()).collect();
+    widgets::popup_menu(ui, pop, dr.left_bottom(), &opts, Some(cur))
+}
+
+/// Curves: channel popup, Bezier/pencil mode, Reset, and the graph bound to the channel's
+/// hidden point-list parameter.
+#[allow(clippy::too_many_arguments)]
+pub(super) fn curves_editor(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    p: &egui::Painter,
+    layer: &Layer,
+    g: &PropGroup,
+    ectx: &EvalCtx,
+    r: Rect,
+    actions: &mut Actions,
+) {
+    let t = app.tokens;
+    let euid = g.uid;
+    // The channel lives in the effect's hidden Channel parameter (UI state for instances
+    // saved before it existed).
+    let chan_prop = g.get("channel");
+    let ch = match chan_prop {
+        Some(pr) => ectx.value(layer, pr).as_enum() as usize,
+        None => app.ui.fx_curve_channel.get(&euid).copied().unwrap_or(0),
+    }
+    .min(4);
+    let x0 = r.min.x + 30.0;
+    let cy = r.min.y + 17.0;
+    let names: [&str; 5] = [crate::i18n::tr("RGB"), crate::i18n::tr("Red"), crate::i18n::tr("Green"), crate::i18n::tr("Blue"), crate::i18n::tr("Alpha")];
+    if let Some(n) = channel_popup(app, ui, p, x0, cy, ch, &names, egui::Id::unique(("ec-cch", euid)), &format!("effectControls.effect.{euid}.curves.channel"))
+    {
+        match chan_prop {
+            Some(pr) => actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": pr.uid, "value": n}))),
+            None => {
+                app.ui.fx_curve_channel.insert(euid, n);
+            }
+        }
+    }
+    let pencil = app.ui.fx_curve_pencil.contains(&euid);
+    let mr = Rect::from_min_size(pos2(x0 + 146.0, cy - 9.0), vec2(56.0, 18.0));
+    if widgets::dropdown(ui, mr, if pencil { "Pencil" } else { "Bezier" }, &t, egui::Id::unique(("ec-cmode", euid))).clicked() {
+        if pencil {
+            app.ui.fx_curve_pencil.remove(&euid);
+        } else {
+            app.ui.fx_curve_pencil.insert(euid);
+        }
+    }
+    app.auto.add(&format!("effectControls.effect.{euid}.curves.mode"), mr, "Curve mode");
+    let Some(prop) = g.get(fw::CURVE_CHANNELS[ch].0) else { return };
+    let cur = match ectx.value(layer, prop) {
+        Value::Str(s) => fw::CurvePoints::parse(&s),
+        _ => fw::CurvePoints::identity(),
+    };
+    let rr = Rect::from_min_size(pos2(mr.max.x + 8.0, cy - 9.0), vec2(44.0, 18.0));
+    let rresp = ui.interact(rr, egui::Id::unique(("ec-creset", euid)), Sense::click());
+    p.text(rr.center(), Align2::CENTER_CENTER, crate::i18n::tr("Reset"), Tokens::ui(11.5), if rresp.hovered() { t.hot_text } else { t.text_dim });
+    app.auto.add(&format!("effectControls.effect.{euid}.curves.reset"), rr, "Reset curve");
+    if rresp.clicked() {
+        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": prop.uid, "value": fw::CurvePoints::identity().format()})));
+    }
+    let size = curves_size(r.width());
+    let gr = Rect::from_min_size(pos2(x0 + 8.0, r.min.y + 38.0), vec2(size, size));
+    // Input/output gradients along the axes.
+    let col = channel_color(ch);
+    p.rect_filled(Rect::from_min_max(pos2(gr.min.x, gr.max.y + 3.0), pos2(gr.max.x, gr.max.y + 8.0)), 0.0, col.gamma_multiply(0.5));
+    let id = egui::Id::unique(("ec-curves", euid, ch));
+    let (resp, edit) = fw::curves_graph(ui, gr, &cur, ch, fw::CurveMode { pencil, natural: true }, id, &t);
+    app.auto.add(&format!("effectControls.effect.{euid}.curves.graph"), gr, "Curves");
+    let started = resp.drag_started() || resp.clicked();
+    if let Some(np) = edit.changed {
+        let key = gesture_key(ui, id, started);
+        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": prop.uid, "value": np.format(), "merge": key})));
+    }
+    p.text(
+        pos2(gr.min.x, gr.max.y + 18.0),
+        Align2::LEFT_CENTER,
+        if pencil { "Drag to draw the curve" } else { "Click adds a point; drag one off to remove" },
+        Tokens::ui(10.5),
+        t.text_faint,
+    );
+}
+
+/// Levels parameter ids for a channel: input black, input white, gamma, output black, output white.
+fn levels_ids(effect: &str, ch: usize) -> [String; 5] {
+    if effect == "ec.color.levels" {
+        return effectcraft_engine::effects::levels_channel_ids(ch);
+    }
+    // Levels (Individual Controls) nests each channel's controls in its twirl-down group.
+    let pre = fw::LEVELS_CHANNELS[ch.min(4)].0;
+    ["InBlack", "InWhite", "Gamma", "OutBlack", "OutWhite"].map(|s| format!("{pre}/{pre}{s}"))
+}
+
+/// Levels: (channel popup,) histogram, input black/gamma/white triangles, output bar with
+/// black/white triangles.
+#[allow(clippy::too_many_arguments)]
+pub(super) fn levels_editor(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    p: &egui::Painter,
+    layer: &Layer,
+    g: &PropGroup,
+    effect: &str,
+    ectx: &EvalCtx,
+    r: Rect,
+    actions: &mut Actions,
+) {
+    let t = app.tokens;
+    let euid = g.uid;
+    let x0 = r.min.x + 30.0;
+    let cy = r.min.y + 17.0;
+    // Levels keeps its channel in the Channel parameter; Levels (Individual Controls) shows
+    // every channel and the popup only picks the histogram.
+    let ch = if effect == "ec.color.levelsic" {
+        app.ui.fx_levels_channel.get(&euid).copied().unwrap_or(0).min(4)
+    } else {
+        g.get("channel").map(|pr| ectx.value(layer, pr).as_enum() as usize).unwrap_or(0).min(4)
+    };
+    if effect == "ec.color.levelsic" {
+        let names: [&str; 5] = [crate::i18n::tr("RGB"), crate::i18n::tr("Red"), crate::i18n::tr("Green"), crate::i18n::tr("Blue"), crate::i18n::tr("Alpha")];
+        if let Some(n) =
+            channel_popup(app, ui, p, x0, cy, ch, &names, egui::Id::unique(("ec-lch", euid)), &format!("effectControls.effect.{euid}.levels.channel"))
+        {
+            app.ui.fx_levels_channel.insert(euid, n);
+        }
+    } else {
+        p.text(pos2(x0, cy), Align2::LEFT_CENTER, crate::i18n::tr("Histogram"), Tokens::ui(12.0), t.text_dim);
+    }
+    let w = (r.width() - 72.0).clamp(120.0, 256.0);
+    let hr = Rect::from_min_size(pos2(x0 + 8.0, r.min.y + 34.0), vec2(w, 80.0));
+    match frame_histogram(app, ui.ctx()) {
+        // Channel 0 (RGB) shows luminance; the others their own channel.
+        Some(h) => fw::draw_histogram(p, hr, &h[ch], channel_color(ch)),
+        None => {
+            p.rect_filled(hr, 0.0, Color32::from_rgb(0x1c, 0x1c, 0x1c));
+        }
+    }
+    app.auto.add(&format!("effectControls.effect.{euid}.levels.histogram"), hr, "Histogram");
+    let ids = levels_ids(effect, ch);
+    let val = |id: &str| g.prop(id).map(|pr| ectx.value(layer, pr).as_f64()).unwrap_or(0.0);
+    let (ib, iw, gm, ob, ow) = (val(&ids[0]), val(&ids[1]), val(&ids[2]), val(&ids[3]), val(&ids[4]));
+    let mut set = |ui: &egui::Ui, id: &str, v: f64, started: bool| {
+        if let Some(pr) = g.prop(id) {
+            let key = gesture_key(ui, egui::Id::unique(("ec-lv", euid, id)), started);
+            actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": pr.uid, "value": v, "merge": key})));
+        }
+    };
+    let track = Rect::from_min_size(pos2(hr.min.x, hr.max.y + 1.0), vec2(w, 10.0));
+    let started = |ui: &egui::Ui| ui.input(|i| i.pointer.any_pressed());
+    let (r0, nv) = fw::level_handle(ui, track, ib, Color32::BLACK, egui::Id::unique(("ec-lib", euid, ch)), &t);
+    app.auto.add(&format!("effectControls.effect.{euid}.levels.inBlack"), r0, "Input Black");
+    if let Some(v) = nv {
+        set(ui, &ids[0], v.min(iw - 0.005), started(ui));
+    }
+    let gx = fw::gamma_handle(ib, iw, gm);
+    let (r1, nv) = fw::level_handle(ui, track, gx, Color32::from_gray(128), egui::Id::unique(("ec-lg", euid, ch)), &t);
+    app.auto.add(&format!("effectControls.effect.{euid}.levels.gamma"), r1, "Gamma");
+    if let Some(v) = nv {
+        set(ui, &ids[2], (fw::gamma_from_handle(ib, iw, v) * 100.0).round() / 100.0, started(ui));
+    }
+    let (r2, nv) = fw::level_handle(ui, track, iw, Color32::WHITE, egui::Id::unique(("ec-liw", euid, ch)), &t);
+    app.auto.add(&format!("effectControls.effect.{euid}.levels.inWhite"), r2, "Input White");
+    if let Some(v) = nv {
+        set(ui, &ids[1], v.max(ib + 0.005), started(ui));
+    }
+    // Output: a black→white bar with its two triangles.
+    let bar = Rect::from_min_size(pos2(hr.min.x, track.max.y + 10.0), vec2(w, 9.0));
+    let n = 32;
+    for k in 0..n {
+        let v = (k as f32 / (n - 1) as f32 * 255.0) as u8;
+        let x0 = bar.min.x + bar.width() * k as f32 / n as f32;
+        let x1 = bar.min.x + bar.width() * (k + 1) as f32 / n as f32;
+        p.rect_filled(Rect::from_min_max(pos2(x0, bar.min.y), pos2(x1, bar.max.y)), 0.0, Color32::from_gray(v));
+    }
+    let otrack = Rect::from_min_size(pos2(bar.min.x, bar.max.y + 1.0), vec2(w, 10.0));
+    let (r3, nv) = fw::level_handle(ui, otrack, ob, Color32::BLACK, egui::Id::unique(("ec-lob", euid, ch)), &t);
+    app.auto.add(&format!("effectControls.effect.{euid}.levels.outBlack"), r3, "Output Black");
+    if let Some(v) = nv {
+        set(ui, &ids[3], v, started(ui));
+    }
+    let (r4, nv) = fw::level_handle(ui, otrack, ow, Color32::WHITE, egui::Id::unique(("ec-low", euid, ch)), &t);
+    app.auto.add(&format!("effectControls.effect.{euid}.levels.outWhite"), r4, "Output White");
+    if let Some(v) = nv {
+        set(ui, &ids[4], v, started(ui));
+    }
+}
+
+/// Auto Levels / Auto Contrast / Auto Color: the histogram they work from.
+pub(super) fn histogram_only(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, g: &PropGroup, r: Rect) {
+    let t = app.tokens;
+    let x0 = r.min.x + 30.0;
+    p.text(pos2(x0, r.min.y + 12.0), Align2::LEFT_CENTER, crate::i18n::tr("Histogram"), Tokens::ui(12.0), t.text_dim);
+    let w = (r.width() - 72.0).clamp(120.0, 256.0);
+    let hr = Rect::from_min_size(pos2(x0 + 8.0, r.min.y + 24.0), vec2(w, 80.0));
+    match frame_histogram(app, ui.ctx()) {
+        Some(h) => {
+            fw::draw_histogram(p, hr, &h[1], channel_color(1).gamma_multiply(0.6));
+            fw::draw_histogram_overlay(p, hr, &h[2], channel_color(2).gamma_multiply(0.6));
+            fw::draw_histogram_overlay(p, hr, &h[3], channel_color(3).gamma_multiply(0.6));
+        }
+        None => {
+            p.rect_filled(hr, 0.0, Color32::from_rgb(0x1c, 0x1c, 0x1c));
+        }
+    }
+    app.auto.add(&format!("effectControls.effect.{}.histogram", g.uid), hr, "Histogram");
+}
diff --git a/crates/ui-egui/src/panels/effect_controls/panel.rs b/crates/ui-egui/src/panels/effect_controls/panel.rs
new file mode 100644
index 000000000..39cdee76c
--- /dev/null
+++ b/crates/ui-egui/src/panels/effect_controls/panel.rs
@@ -0,0 +1,377 @@
+use super::common::{Actions, PARAM_NAME_X, ROW, effect_active, selected_layer};
+use super::editors::{curves_editor, editor_height, histogram_only, levels_editor, object_matte_editor, roto_editor, warp_editor};
+use super::rows::{FxScope, group_rows, toggle_closed};
+use super::{Align2, Color32, EffectcraftApp, EvalCtx, GroupKind, Icon, Layer, PropGroup, Rect, Sense, Stroke, Tokens, json, pos2, vec2, widgets};
+
+// ---------------------------------------------------------------------------------------------
+
+/// Open the rename field on effect `uid` (Enter with the effect selected), name selected.
+pub fn start_rename(ctx: &egui::Context, uid: u64, name: &str) {
+    let id = egui::Id::unique(("ec-rename", uid));
+    ctx.data_mut(|d| d.insert_temp(id, name.to_string()));
+    ctx.data_mut(|d| d.insert_temp(id.with("select"), true));
+    ctx.memory_mut(|m| m.request_focus(id.with("field")));
+}
+
+/// Where an effect header's parts sit, for its rename field.
+struct EffectHdr<'a> {
+    g: &'a PropGroup,
+    shown: &'a str,
+    r: Rect,
+    tw: Rect,
+    reset: Rect,
+    rename_id: egui::Id,
+    layer_id: u64,
+}
+
+/// The effect header's name field while renaming: Enter or blur commits, Escape cancels.
+fn rename_field(app: &mut EffectcraftApp, ui: &mut egui::Ui, h: &EffectHdr, mut value: String, actions: &mut Actions) {
+    let EffectHdr { g, shown, r, tw, reset, rename_id, layer_id } = *h;
+    let ctx = ui.ctx().clone();
+    let name_rect = Rect::from_min_max(pos2(tw.max.x + 6.0, r.min.y + 2.0), pos2(reset.min.x - 6.0, r.max.y - 2.0));
+    let response = ui.put(name_rect, egui::TextEdit::singleline(&mut value).id(rename_id.with("field")).font(Tokens::semibold(12.0)));
+    // Focus the field the frame it first exists: focusing an id not yet on screen leaves
+    // the accessibility tree with a focus it doesn't contain.
+    if ctx.data_mut(|d| d.remove_temp::<bool>(rename_id.with("start"))).is_some() {
+        crate::widgets::select_all(&ctx, response.id, &value);
+        response.request_focus();
+    }
+    app.auto.add(&format!("effectControls.effect.{}.nameEdit", g.uid), name_rect, "Effect name");
+    if ctx.data_mut(|d| d.remove_temp::<bool>(rename_id.with("select"))).unwrap_or(false) {
+        widgets::select_all(&ctx, response.id, &value);
+    }
+    // Escape cancels. egui drops the field's focus on Escape in the same frame, so the
+    // key is checked on the focus being lost as well as held.
+    let escape = (response.has_focus() || response.lost_focus()) && ui.input(|i| i.key_pressed(egui::Key::Escape));
+    let commit = response.lost_focus() || (response.has_focus() && ui.input(|i| i.key_pressed(egui::Key::Enter)));
+    if escape || commit {
+        ctx.data_mut(|d| d.remove::<String>(rename_id));
+        // The field opens with the drawn name, so committing it unchanged is not a rename.
+        if !escape && !value.trim().is_empty() && value != shown {
+            actions.push(("prop.renameGroup".into(), json!({"layer": layer_id, "prop": g.uid, "name": value})));
+        }
+    } else {
+        ctx.data_mut(|d| d.insert_temp(rename_id, value));
+    }
+}
+
+struct EditorCx<'a> {
+    bp: &'a egui::Painter,
+    layer: &'a Layer,
+    ectx: &'a EvalCtx<'a>,
+}
+
+/// An effect's custom editor (curves, levels, roto...), or the histogram-only fallback.
+fn effect_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &EditorCx, g: &PropGroup, er: Rect, actions: &mut Actions) {
+    let GroupKind::Effect { effect } = &g.kind else { return };
+    match effect.as_str() {
+        "ec.color.curves" => curves_editor(app, ui, cx.bp, cx.layer, g, cx.ectx, er, actions),
+        effectcraft_engine::effects::warp_stab::ID => warp_editor(app, ui, cx.bp, cx.layer, g, er, actions),
+        effectcraft_engine::effects::camera_tracker::ID => crate::panels::camera_tracker_ui::editor(app, ui, cx.bp, cx.layer, g, er, actions),
+        effectcraft_engine::effects::roto::ID => roto_editor(app, ui, cx.bp, cx.layer, g, er, actions),
+        effectcraft_engine::effects::object_matte::ID => object_matte_editor(app, ui, cx.bp, cx.layer, g, er, actions),
+        "ec.color.levels" | "ec.color.levelsic" => levels_editor(app, ui, cx.bp, cx.layer, g, effect, cx.ectx, er, actions),
+        crate::panels::fx_editors::GLOW | crate::panels::fx_editors::RESHAPE | crate::panels::fx_editors::EXTRACTOR => {
+            crate::panels::fx_editors::header_editor(app, ui, cx.bp, cx.layer, g, effect, cx.ectx, er, actions)
+        }
+        _ => histogram_only(app, ui, cx.bp, g, er),
+    }
+}
+
+struct ReorderDrag<'a> {
+    tops: &'a [(u64, f32)],
+    y: f32,
+    du: u64,
+    drag_id: egui::Id,
+    layer_id: u64,
+}
+
+/// Drag an effect header to reorder: the insertion line between headers, and the drop.
+fn reorder_drag(ctx: &egui::Context, bp: &egui::Painter, body: Rect, t: &Tokens, st: &ReorderDrag, actions: &mut Actions) {
+    let ReorderDrag { tops, y, du, drag_id, layer_id } = *st;
+    if let Some(pos) = ctx.pointer_interact_pos() {
+        let slot = tops.iter().position(|(_, ty)| pos.y < *ty + (ROW + 2.0) / 2.0).unwrap_or(tops.len());
+        let ly = tops.get(slot).map(|(_, ty)| *ty).unwrap_or(y - 4.0);
+        bp.line_segment([pos2(body.min.x + 4.0, ly), pos2(body.max.x - 4.0, ly)], Stroke::new(2.0, t.accent));
+        if ctx.input(|i| i.pointer.any_released()) {
+            if let Some(from) = tops.iter().position(|(u, _)| *u == du) {
+                let to = if slot > from { slot - 1 } else { slot };
+                if to != from {
+                    actions.push(("effect.reorder".into(), json!({"layer": layer_id, "effect": du, "index": to + 1})));
+                }
+            }
+            ctx.data_mut(|d| d.remove::<u64>(drag_id));
+        }
+    }
+    if !ctx.input(|i| i.pointer.any_down()) {
+        ctx.data_mut(|d| d.remove::<u64>(drag_id));
+    }
+}
+
+/// Drop effects and animation presets here.
+fn drop_payload(ui: &egui::Ui, rect: Rect, p: &egui::Painter, t: &Tokens, layer_id: u64, actions: &mut Actions) {
+    let ctx = ui.ctx().clone();
+    if let Some(payload) = egui::DragAndDrop::payload::<crate::panels::DragPayload>(&ctx)
+        && ui.rect_contains_pointer(rect)
+        && let Some((id, params)) = match payload.as_ref() {
+            crate::panels::DragPayload::Effect(e) => Some(("effect.apply", json!({"effect": e, "layers": [layer_id]}))),
+            crate::panels::DragPayload::Preset { preset, .. } => Some(preset.apply_to(layer_id)),
+            _ => None,
+        }
+    {
+        p.rect_stroke(rect, 0.0, Stroke::new(2.0, t.accent), egui::StrokeKind::Inside);
+        if ctx.input(|i| i.pointer.any_released()) {
+            actions.push((id.into(), params));
+            egui::DragAndDrop::clear_payload(&ctx);
+        }
+    }
+}
+
+fn about_button(app: &mut EffectcraftApp, ui: &mut egui::Ui, bp: &egui::Painter, t: &Tokens, effect: &str, g: &PropGroup, r: Rect) {
+    // About…: the effect's name and category (AE's About dialog).
+    let about = Rect::from_min_size(pos2(r.max.x - 50.0, r.center().y - 9.0), vec2(44.0, 18.0));
+    let aresp = ui.interact(about, egui::Id::unique(("ec-about", g.uid)), Sense::click());
+    bp.text(about.center(), Align2::CENTER_CENTER, crate::i18n::tr("About..."), Tokens::ui(11.5), if aresp.hovered() { t.hot_text } else { t.text_dim });
+    app.auto.add(&format!("effectControls.effect.{}.about", g.uid), about, "About");
+    let apop = egui::Id::unique(("ec-about-pop", g.uid));
+    if aresp.clicked() {
+        widgets::open_popup(ui, apop);
+    }
+    if let Some(spec) = effectcraft_engine::effects::find(effect) {
+        let lines = vec![
+            crate::i18n::effects::name(spec.id, spec.name),
+            format!("Category: {}", crate::i18n::effects::category(spec.category)),
+            "EffectCraft built-in effect (MIT OR Apache-2.0)".to_string(),
+        ];
+        let _ = widgets::popup_menu(ui, apop, about.left_bottom(), &lines, None);
+    }
+}
+
+/// The Effect Controls panel for the selected layer: a header with the comp and layer names, then
+/// one header per effect (Fx toggle, twirl, rename, Reset, About, label bar, reorder drag and its
+/// right-click menu) followed by that effect's custom editor and its property rows. Dragging
+/// effects or presets onto the panel applies them; a right-click on empty space opens the Effect
+/// menu. The rows read from a snapshot of the project, and every edit is queued and run through
+/// [`crate::menus::invoke`], with failures reported in `app.ui.status`.
+pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+    let t = app.tokens;
+    let p = ui.painter().with_clip_rect(rect);
+    let ctx = ui.ctx().clone();
+    let Some(layer) = selected_layer(app) else {
+        p.text(rect.center(), Align2::CENTER_CENTER, crate::i18n::tr("Select a layer to see its effects"), Tokens::ui(12.0), t.text_faint);
+        return;
+    };
+    let Some(cid) = app.session.active_comp_id() else { return };
+    let comp = app.session.project.comp_arc(cid).unwrap_or_else(|| effectcraft_engine::project::Comp::new(1, 1, Default::default(), Default::default()).into());
+    let comp_name = app.session.project.item(cid).map(|i| i.name.clone()).unwrap_or_default();
+    let snap_project = app.session.project.clone();
+    let snap_expr = app.session.expr.clone();
+    let ectx = EvalCtx { project: &snap_project, comp_id: cid, comp: &comp, time: app.session.time(), expr: snap_expr.as_deref(), footage: None };
+    let hdr = Rect::from_min_size(rect.min, vec2(rect.width(), 24.0));
+    p.text(pos2(hdr.min.x + 10.0, hdr.center().y), Align2::LEFT_CENTER, format!("{} • {}", comp_name, layer.name), Tokens::ui(11.5), t.text_dim);
+    p.line_segment([hdr.left_bottom(), hdr.right_bottom()], Stroke::new(1.0, t.separator));
+    let body = Rect::from_min_max(pos2(rect.min.x, hdr.max.y), rect.max);
+    let scroll = widgets::PanelScroll::begin(ui, egui::Id::unique("ec-scroll"), body);
+    let mut y = body.min.y + 4.0 - scroll.offset;
+    let mut actions: Actions = vec![];
+    let bp = p.with_clip_rect(body);
+    // Rows scroll under the header: clip their widgets (and hit tests) to the body.
+    let panel_clip = ui.clip_rect();
+    ui.set_clip_rect(body.intersect(panel_clip));
+    let fx: Vec<PropGroup> = layer.effects().map(|f| f.groups().cloned().collect()).unwrap_or_default();
+    if fx.is_empty() {
+        bp.text(
+            pos2(body.center().x, body.min.y + 40.0),
+            Align2::CENTER_CENTER,
+            "No effects. Drag one from Effects & Presets.",
+            Tokens::ui(12.0),
+            t.text_faint,
+        );
+    }
+    // Clicking empty space deselects the effects.
+    let bg = ui.interact(body, egui::Id::unique("ec-bg"), Sense::click());
+    if bg.clicked() {
+        app.session.state.selected_props.retain(|(l, u)| !(*l == layer.id && fx.iter().any(|g| effect_active(g, layer.id, &[(*l, *u)]))));
+    }
+    let has_clip = !app.session.state.effect_clipboard.is_empty();
+    let drag_id = egui::Id::unique("ec-drag-effect");
+    let dragging: Option<u64> = ctx.data(|d| d.get_temp(drag_id));
+    // Header tops, for drag-to-reorder.
+    let mut tops: Vec<(u64, f32)> = vec![];
+    for (fi, g) in fx.iter().enumerate() {
+        let GroupKind::Effect { effect } = &g.kind else { continue };
+        // The header draws the effect's name in the interface language; the automation labels
+        // below keep the property tree's name, which is the registry's English name (#821).
+        let shown = crate::i18n::effects::group(effect, &g.name);
+        let r = Rect::from_min_size(pos2(body.min.x, y), vec2(body.width(), ROW + 2.0));
+        tops.push((g.uid, r.min.y));
+        y += ROW + 2.0;
+        let open = !app.ui.fx_closed.contains(&g.uid);
+        let selected = app.session.state.selected_props.iter().any(|(l, u)| *l == layer.id && *u == g.uid);
+        let active = effect_active(g, layer.id, &app.session.state.selected_props);
+        bp.rect_filled(r, 0.0, if active { t.fx_header_active } else { t.fx_header });
+        // The effect's colour label (26.5): a bar on the header's left edge.
+        if let Some(lab) = g.label.filter(|l| *l != effectcraft_engine::color::Label::None) {
+            let [lr, lg, lb] = app.session.prefs.label_rgb(lab);
+            bp.rect_filled(Rect::from_min_size(r.min, vec2(4.0, r.height())), 0.0, Color32::from_rgb(lr, lg, lb));
+            app.auto.add(
+                &format!("effectControls.effect.{}.label", g.uid),
+                Rect::from_min_size(r.min, vec2(4.0, r.height())),
+                &app.session.prefs.label_name(lab),
+            );
+        }
+        let fxr = Rect::from_center_size(pos2(r.min.x + 14.0, r.center().y), vec2(16.0, 16.0));
+        if widgets::icon_toggle(ui, fxr, Icon::Fx, g.enabled, &t, egui::Id::unique(("ec-fx", g.uid)), Sense::click()).clicked() {
+            actions.push(("effect.toggle".into(), json!({"layer": layer.id.0, "effect": g.uid})));
+        }
+        app.auto.add(&format!("effectControls.effect.{}.fx", g.uid), fxr, &g.name);
+        let tw = Rect::from_center_size(pos2(r.min.x + 32.0, r.center().y), vec2(12.0, 12.0));
+        if widgets::twirl(ui, tw, open, egui::Id::unique(("ec-tw", g.uid)), &t).clicked() {
+            toggle_closed(app, g, open, ui.input(|i| i.modifiers.alt || i.modifiers.command));
+        }
+        app.auto.add(&format!("effectControls.effect.{}.twirl", g.uid), tw, &g.name);
+        let rename_id = egui::Id::unique(("ec-rename", g.uid));
+        let editing: Option<String> = ctx.data(|d| d.get_temp(rename_id));
+        let reset = Rect::from_min_size(pos2(r.max.x - 96.0, r.center().y - 9.0), vec2(40.0, 18.0));
+        let hdr_cx = EffectHdr { g, shown: &shown, r, tw, reset, rename_id, layer_id: layer.id.0 };
+        if let Some(value) = editing.as_ref().cloned() {
+            rename_field(app, ui, &hdr_cx, value, &mut actions);
+        } else {
+            let name = bp.text(pos2(tw.max.x + 6.0, r.center().y), Align2::LEFT_CENTER, &shown, Tokens::semibold(12.0), t.text);
+            app.auto.add(&format!("effectControls.effect.{}.name", g.uid), name, &g.name);
+        }
+        let rresp = ui.interact(reset, egui::Id::unique(("ec-reset", g.uid)), Sense::click());
+        bp.text(reset.center(), Align2::CENTER_CENTER, crate::i18n::tr("Reset"), Tokens::ui(11.5), if rresp.hovered() { t.hot_text } else { t.text_dim });
+        app.auto.add(&format!("effectControls.effect.{}.reset", g.uid), reset, "Reset");
+        if rresp.clicked() {
+            actions.push(("effect.reset".into(), json!({"layer": layer.id.0, "effect": g.uid})));
+        }
+        about_button(app, ui, &bp, &t, effect, g, r);
+        let hresp = ui.interact(
+            Rect::from_min_max(pos2(tw.max.x, r.min.y), pos2(reset.min.x - 4.0, r.max.y)),
+            egui::Id::unique(("ec-hdr", g.uid)),
+            if editing.is_some() { Sense::hover() } else { Sense::click_and_drag() },
+        );
+        if hresp.double_clicked() {
+            ctx.data_mut(|d| d.insert_temp(rename_id, shown.clone()));
+            ctx.data_mut(|d| d.insert_temp(rename_id.with("start"), true));
+        }
+        hresp.widget_info(|| egui::WidgetInfo::selected(egui::Role::Button, true, active, &shown));
+        app.auto.add(&format!("effectControls.effect.{}", g.uid), r, &g.name);
+        if hresp.clicked() || hresp.drag_started() || hresp.secondary_clicked() {
+            let add = ui.input(|i| i.modifiers.shift || i.modifiers.command);
+            if add && hresp.clicked() {
+                if selected {
+                    app.session.state.selected_props.retain(|(l, u)| !(*l == layer.id && *u == g.uid));
+                } else {
+                    app.session.state.selected_props.push((layer.id, g.uid));
+                }
+            } else if !selected || hresp.clicked() {
+                app.session.state.selected_props = vec![(layer.id, g.uid)];
+            }
+        }
+        if hresp.drag_started() {
+            ctx.data_mut(|d| d.insert_temp(drag_id, g.uid));
+        }
+        crate::widgets::context_menu(&hresp, |ui| {
+            let lid = layer.id.0;
+            let mut picked_label: Option<usize> = None;
+            let mut item = |ui: &mut egui::Ui, label: &str, enabled: bool, cmd: &str, params: serde_json::Value| {
+                if ui.add_enabled(enabled, egui::Button::new(crate::i18n::context_item(cmd, &params, label))).clicked() {
+                    actions.push((cmd.into(), params));
+                    ui.close();
+                }
+            };
+            item(ui, "Copy", true, "effect.copy", json!({"layer": lid, "effect": g.uid}));
+            item(ui, "Paste", has_clip, "effect.paste", json!({"layers": [lid]}));
+            item(ui, "Duplicate", true, "effect.duplicate", json!({"layer": lid, "effect": g.uid}));
+            if ui.button(crate::i18n::tr("Rename")).clicked() {
+                ctx.data_mut(|d| d.insert_temp(rename_id, shown.clone()));
+                ctx.data_mut(|d| d.insert_temp(rename_id.with("start"), true));
+                ui.close();
+            }
+            ui.separator();
+            ui.menu_button(crate::i18n::tr("Label"), |ui| {
+                let cur = g.label.unwrap_or(effectcraft_engine::color::Label::None);
+                for (i, l) in effectcraft_engine::color::Label::ALL.into_iter().enumerate() {
+                    if widgets::label_entry(ui, l, &app.session.prefs.label_name(l), l == cur, &t).clicked() {
+                        picked_label = Some(i);
+                        ui.close();
+                    }
+                }
+            });
+            item(ui, "Reset", true, "effect.reset", json!({"layer": lid, "effect": g.uid}));
+            item(ui, "Remove", true, "effect.remove", json!({"layer": lid, "effect": g.uid}));
+            ui.separator();
+            item(ui, "Move Up", fi > 0, "effect.reorder", json!({"layer": lid, "effect": g.uid, "index": fi.max(1)}));
+            item(ui, "Move Down", fi + 1 < fx.len(), "effect.reorder", json!({"layer": lid, "effect": g.uid, "index": fi + 2}));
+            if let Some(i) = picked_label {
+                actions.push(("effect.setLabel".into(), json!({"layer": lid, "effect": g.uid, "label": i})));
+            }
+        });
+        // What the effect can't render as asked (an OCIO config it can't read, transforms it
+        // passes through), under its name.
+        if let Some(w) = effectcraft_engine::effects::warning(g, &mut |pr| ectx.value(&layer, pr)) {
+            let galley = bp.layout(format!("⚠ {w}"), Tokens::ui(11.0), t.warning, (body.width() - 20.0).max(60.0));
+            let wr = Rect::from_min_size(pos2(body.min.x + 10.0, y + 3.0), galley.size());
+            bp.galley(wr.min, galley, t.warning);
+            app.auto.add(&format!("effectControls.effect.{}.warning", g.uid), wr, &w);
+            y += wr.height() + 6.0;
+        }
+        if open {
+            let eh = editor_height(effect, g, body.width());
+            if eh > 0.0 {
+                let er = Rect::from_min_size(pos2(body.min.x, y), vec2(body.width(), eh));
+                y += eh;
+                if er.max.y >= body.min.y && er.min.y <= body.max.y {
+                    // Curves, Levels and other custom editors do not use prop_row.
+                    // Clicking their controls must activate the owner as well.
+                    if ui.input(|i| i.pointer.primary_pressed()) && ui.rect_contains_pointer(er) {
+                        actions.push(("prop.select".into(), json!({"layer":layer.id.0,"prop":g.uid})));
+                    }
+                    effect_editor(app, ui, &EditorCx { bp: &bp, layer: &layer, ectx: &ectx }, g, er, &mut actions);
+                }
+            }
+            let scope = FxScope { effect: effect.as_str(), root: g, path: String::new() };
+            group_rows(app, ui, &bp, &layer, g, &ectx, body, &mut y, 0, &scope, &mut actions);
+            if effect == "ec.color.tint" {
+                let r = Rect::from_min_size(pos2(body.min.x + PARAM_NAME_X, y + 2.0), vec2(120.0, ROW));
+                let label = crate::i18n::tr("Swap Colors");
+                let resp = widgets::text_button(ui, r, label, false, &t, egui::Id::unique(("ec-tint-swap", g.uid)));
+                app.auto.add_response(&format!("effectControls.effect.{}.swapColors", g.uid), &resp, label);
+                if resp.clicked() {
+                    actions.push(("prop.select".into(), json!({"layer": layer.id.0, "prop": g.uid})));
+                    actions.push(("effect.swapTintColors".into(), json!({"layer": layer.id.0, "effect": g.uid})));
+                }
+                y += ROW + 4.0;
+            }
+        }
+        y += 4.0;
+    }
+    if let Some(du) = dragging {
+        reorder_drag(&ctx, &bp, body, &t, &ReorderDrag { tops: &tops, y, du, drag_id, layer_id: layer.id.0 }, &mut actions);
+    }
+    // Right-click anywhere a control has no menu of its own: the Effect menu, which applies to
+    // the selected layers (After Effects). Drawn after the rows, whose menus open first.
+    let menu_id = bg.id.with("effect-menu");
+    let open = ui.input(|i| i.pointer.secondary_clicked())
+        && ui.rect_contains_pointer(body)
+        && (!egui::Popup::is_any_open(&ctx) || egui::Popup::is_id_open(&ctx, menu_id));
+    egui::Popup::context_menu(&bg).style(crate::widgets::menu_style).id(menu_id).open_memory(open.then_some(egui::SetOpenCommand::Bool(true))).show(|ui| {
+        ui.set_min_width(200.0);
+        actions.extend(crate::menus::menu_contents(app, ui, "Effect"));
+    });
+    ui.set_clip_rect(panel_clip);
+    let content_h = y + scroll.offset - body.min.y;
+    scroll.end(ui, &mut app.auto, "effectControls.scroll", content_h, &t);
+    drop_payload(ui, rect, &p, &t, layer.id.0, &mut actions);
+    if ui.input(|i| i.pointer.primary_down()) && actions.iter().any(|(id, _)| id == "prop.set") {
+        app.ui.viewer.property_interacting = true;
+        ctx.request_repaint();
+    }
+    for (id, params) in actions {
+        if let Err(e) = crate::menus::invoke(app, &ctx, &id, params) {
+            app.ui.status = e;
+        }
+    }
+}
diff --git a/crates/ui-egui/src/panels/effect_controls/rows.rs b/crates/ui-egui/src/panels/effect_controls/rows.rs
new file mode 100644
index 000000000..05fea44c9
--- /dev/null
+++ b/crates/ui-egui/src/panels/effect_controls/rows.rs
@@ -0,0 +1,726 @@
+use super::common::{Actions, DIAL_ROW, PARAM_NAME_X, ROW, TREE_INDENT, gesture_key};
+use super::{
+    Align2, Color32, EffectcraftApp, EvalCtx, FxPick, Icon, Layer, Node, ParamUi, PropGroup, Property, Rect, Sense, Stroke, Tokens, Value, fw, icons, json,
+    pos2, vec2, widgets,
+};
+
+fn triangle(p: &egui::Painter, c: egui::Pos2, left: bool, col: Color32) {
+    let (dx, h) = (if left { -3.5 } else { 3.5 }, 4.0);
+    p.add(egui::Shape::convex_polygon(vec![pos2(c.x + dx, c.y), pos2(c.x - dx, c.y - h), pos2(c.x - dx, c.y + h)], col, Stroke::NONE));
+}
+
+/// The layer and whether the time is on a key, for the key navigator.
+#[derive(Clone, Copy)]
+struct KeyNav {
+    layer_id: u64,
+    on_key: bool,
+}
+
+/// ◀ ◆ ▶ at the right end of an animated parameter's row.
+fn key_navigator(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, nav: KeyNav, prop: &Property, r: Rect, actions: &mut Actions) {
+    let KeyNav { layer_id, on_key } = nav;
+    let t = app.tokens;
+    let cy = r.center().y;
+    let uid = prop.uid;
+    for (what, dx) in [("prev", -44.0), ("key", -32.0), ("next", -20.0)] {
+        let cr = Rect::from_center_size(pos2(r.max.x + dx, cy), vec2(12.0, 16.0));
+        let resp = ui.interact(cr, egui::Id::unique(("ec-nav", uid, what)), Sense::click());
+        let col = if resp.hovered() { t.text } else { t.text_dim };
+        match what {
+            "prev" => triangle(p, cr.center(), true, col),
+            "next" => triangle(p, cr.center(), false, col),
+            _ => {
+                let kr = Rect::from_center_size(cr.center(), vec2(10.0, 10.0));
+                if on_key {
+                    icons::paint(p, kr, Icon::Keyframe, t.keyframe);
+                } else {
+                    let c = kr.center();
+                    let d = 4.5;
+                    p.add(egui::Shape::closed_line(
+                        vec![pos2(c.x, c.y - d), pos2(c.x + d, c.y), pos2(c.x, c.y + d), pos2(c.x - d, c.y)],
+                        Stroke::new(1.0, col),
+                    ));
+                }
+            }
+        }
+        app.auto.add(&format!("effectControls.prop.{uid}.{what}Key"), cr, &prop.name);
+        if resp.clicked() {
+            match what {
+                "prev" => actions.push(("time.go".into(), json!({"to": "prevKey", "prop": uid}))),
+                "next" => actions.push(("time.go".into(), json!({"to": "nextKey", "prop": uid}))),
+                _ => actions.push(("prop.toggleKey".into(), json!({"layer": layer_id, "prop": uid, "selected": true}))),
+            }
+        }
+    }
+}
+
+/// Toggle a viewer pick (crosshair / eyedropper) for a parameter (also the Timeline's colour
+/// eyedroppers).
+pub(crate) fn toggle_pick(app: &mut EffectcraftApp, kind: &str, layer: &Layer, prop: &Property) {
+    let pick = FxPick { kind: kind.into(), layer: layer.id.0, prop: prop.uid, name: prop.name.clone() };
+    if app.ui.fx_pick.as_ref() == Some(&pick) {
+        app.ui.fx_pick = None;
+    } else {
+        app.ui.fx_pick = Some(pick);
+        app.ui.text_color_pick = None;
+        app.ui.status = if kind == "point" {
+            format!("Click in the Composition panel to set {}", prop.name)
+        } else {
+            format!("Click in the Composition panel to sample {}", prop.name)
+        };
+    }
+}
+
+/// What the value controls of one property row share.
+#[derive(Clone, Copy)]
+struct PropCx<'a> {
+    p: &'a egui::Painter,
+    layer: &'a Layer,
+    group: &'a PropGroup,
+    prop: &'a Property,
+    r: Rect,
+    vx: f32,
+    cy: f32,
+    swr: Rect,
+    t: Tokens,
+    uid: u64,
+    scrub: bool,
+}
+
+impl PropCx<'_> {
+    fn set(&self, actions: &mut Actions, v: serde_json::Value) {
+        let (layer, uid, merge, scrub) = (self.layer, self.uid, format!("ec-{}", self.uid), self.scrub);
+        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": uid, "value": v, "merge": merge, "selected": true, "offset": scrub})))
+    }
+
+    fn twirl_open(&self, app: &mut EffectcraftApp, ui: &mut egui::Ui) {
+        let PropCx { swr, cy, uid, prop, t, .. } = self;
+        let (cy, uid) = (*cy, *uid);
+        let open = app.ui.fx_slider_open.contains(&uid);
+        let tw = Rect::from_center_size(pos2(swr.min.x - 9.0, cy), vec2(10.0, 10.0));
+        if widgets::twirl(ui, tw, open, egui::Id::unique(("ec-stw", uid)), t).clicked() {
+            if open {
+                app.ui.fx_slider_open.remove(&uid);
+            } else {
+                app.ui.fx_slider_open.insert(uid);
+            }
+        }
+        app.auto.add(&format!("effectControls.prop.{uid}.twirl"), tw, &prop.name);
+    }
+}
+
+/// One property row: stopwatch, name, value control (and the keyframe navigator). Returns the
+/// value fields of a vector, one per dimension, for the pick whip.
+#[allow(clippy::too_many_arguments)]
+fn prop_row(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    p: &egui::Painter,
+    layer: &Layer,
+    group: &PropGroup,
+    prop: &Property,
+    ectx: &EvalCtx,
+    r: Rect,
+    indent: f32,
+    actions: &mut Actions,
+) -> Vec<Rect> {
+    let t = app.tokens;
+    let mut dims = vec![];
+    let cy = r.center().y;
+    let uid = prop.uid;
+    if ui.input(|i| i.pointer.primary_pressed()) && ui.rect_contains_pointer(r) {
+        let add = ui.input(|i| i.modifiers.shift || i.modifiers.command);
+        actions.push(("prop.select".into(), json!({"layer": layer.id.0, "prop": uid, "add": add})));
+    }
+    let swr = Rect::from_center_size(pos2(r.min.x + indent, cy), vec2(14.0, 14.0));
+    if !prop.static_only && !matches!(prop.ui, ParamUi::Hidden) {
+        let resp = ui.interact(swr, egui::Id::unique(("ec-sw", uid)), Sense::click());
+        icons::paint(
+            p,
+            swr,
+            Icon::Stopwatch,
+            if prop.is_animated() {
+                t.hot_text
+            } else if resp.hovered() {
+                t.text
+            } else {
+                t.text_dim
+            },
+        );
+        app.auto.add(&format!("effectControls.prop.{uid}.stopwatch"), swr, &prop.name);
+        if resp.clicked() {
+            actions.push(("prop.toggleAnimation".into(), json!({"layer": layer.id.0, "prop": uid, "selected": true})));
+        }
+    }
+    if prop.is_animated() {
+        let half = ectx.comp.frame_duration().0 / 2;
+        let on_key = prop.keys.iter().any(|k| (layer.comp_time(k.time).0 - ectx.time.0).abs() <= half);
+        key_navigator(app, ui, p, KeyNav { layer_id: layer.id.0, on_key }, prop, r, actions);
+    }
+    let value = ectx.value(layer, prop);
+    // Keep a shared value column while names and their icons follow the group hierarchy.
+    // Extremely deep groups still leave a little name space before their value.
+    let vx = (r.min.x + r.width() * 0.48).max(r.min.x + PARAM_NAME_X + 124.0).max(swr.max.x + 40.0);
+    // A vector's values end before the keyframe navigator: in a narrow panel they move left over
+    // the name (cut short) instead of running under the navigator (#271).
+    let vx = match &value {
+        Value::Vec2(_) | Value::Vec3(_) => {
+            let point = if matches!(prop.ui, ParamUi::Point | ParamUi::Point3) { 22.0 } else { 0.0 };
+            let fields: f32 = value
+                .components()
+                .iter()
+                .take(shown_dims(layer, prop, &value))
+                .map(|v| p.layout_no_wrap(format!("{v:.1}"), Tokens::ui(12.0), t.hot_text).size().x + 12.0)
+                .sum();
+            let right = r.max.x - if prop.is_animated() { 52.0 } else { 8.0 };
+            vx.min(right - point - fields + 8.0).max(swr.max.x + 60.0)
+        }
+        _ => vx,
+    };
+    let name_clip = Rect::from_min_max(pos2(swr.max.x + 6.0, r.min.y), pos2(vx - 6.0, r.max.y));
+    app.auto.add(&format!("effectControls.prop.{uid}.name"), name_clip, &prop.name);
+    p.with_clip_rect(name_clip.intersect(p.clip_rect())).text(pos2(swr.max.x + 6.0, cy), Align2::LEFT_CENTER, &prop.name, Tokens::ui(12.0), t.text);
+    let name_response = ui.interact(name_clip, egui::Id::unique(("ec-prop-name", uid)), Sense::click());
+    if name_response.double_clicked() {
+        app.ui.timeline.search.clear();
+        app.ui.timeline.scroll_to = Some(crate::state::ScrollTo::Property(uid));
+        if let Err(e) = crate::menus::frontend(app, ui.ctx(), "timeline.revealProps", json!({"props": [{"layer": layer.id.0, "prop": uid}]})) {
+            app.ui.status = e;
+        }
+        app.show_panel(crate::dock::PanelKind::Timeline);
+    }
+    app.auto.add(&format!("effectControls.prop.{uid}.name"), name_clip, &prop.name);
+    // With several layers selected the edit applies to the same effect property of each (#491).
+    let scrub = ui.ctx().dragged_id().is_some() && ui.input(|i| i.pointer.is_decidedly_dragging());
+    let cx = PropCx { p, layer, group, prop, r, vx, cy, swr, t, uid, scrub };
+    match &value {
+        Value::Scalar(_) if matches!(prop.ui, ParamUi::Mask) => value_mask(app, ui, &cx, &value, actions),
+        Value::Scalar(_) if matches!(prop.ui, ParamUi::Angle) => value_angle(app, ui, &cx, &value, actions),
+        Value::Scalar(_) => value_scalar(app, ui, &cx, &value, actions),
+        Value::Vec2(_) | Value::Vec3(_) => dims = value_vector(app, ui, &cx, &value, actions),
+        Value::Color(_) => value_color(app, ui, &cx, &value, actions),
+        Value::Bool(_) => value_toggle(app, ui, &cx, &value, actions),
+        Value::Enum(_) => value_popup(app, ui, &cx, &value, actions),
+        Value::Layer(_) => value_layer_ref(app, ui, &cx, &value, actions),
+        // EXtractoR's red / green / blue / alpha: a popup of the footage's OpenEXR channels (#295).
+        Value::Str(_) if crate::panels::fx_editors::is_extractor_channel(group, prop) => value_extractor(app, ui, &cx, &value, actions),
+        // A file parameter (Apply Color LUT's LUT, an OCIO config): its file name and Choose…,
+        // as in After Effects.
+        Value::Str(_) if matches!(prop.ui, ParamUi::File { .. }) => value_file(app, ui, &cx, &value, actions),
+        // A text parameter (Cryptomatte's Selection, Colorama's Output Cycle, config names):
+        // typed in a field, set when it loses the focus (Esc keeps the old text).
+        Value::Str(_) if matches!(prop.ui, ParamUi::Text) => value_text(app, ui, &cx, &value, actions),
+        Value::Gradient(_) => value_gradient(app, &cx, &value),
+        _ => {}
+    }
+    dims
+}
+
+fn value_mask(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
+    let Value::Scalar(v) = value else {
+        return;
+    };
+    let PropCx { t, uid, cy, vx, r, layer, prop, .. } = *cx;
+    // A mask of this layer ("Path" popup).
+    let mut opts = vec!["None".to_string()];
+    if let Some(m) = layer.masks() {
+        opts.extend(m.groups().map(|g| g.name.clone()));
+    }
+    let i = v.round().max(0.0) as usize;
+    let label = opts.get(i).cloned().unwrap_or_else(|| format!("Mask {i}"));
+    let dr = Rect::from_min_size(pos2(vx, cy - 9.0), vec2((r.max.x - vx - 56.0).clamp(80.0, 200.0), 18.0));
+    let pop = egui::Id::unique(("ec-mpop", uid));
+    if widgets::dropdown(ui, dr, &label, &t, egui::Id::unique(("ec-m", uid))).clicked() {
+        widgets::open_popup(ui, pop);
+    }
+    app.auto.add(&format!("effectControls.prop.{uid}.value"), dr, &prop.name);
+    if let Some(ni) = widgets::popup_menu(ui, pop, dr.left_bottom(), &opts, Some(i)) {
+        cx.set(actions, json!(ni as f64));
+    }
+}
+
+fn value_angle(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
+    let Value::Scalar(v) = value else {
+        return;
+    };
+    let PropCx { t, uid, cy, vx, prop, .. } = *cx;
+    let (rr, dr, nv) = fw::angle_field(ui, pos2(vx, cy - 9.0), egui::Id::unique(("ec-v", uid)), *v, 1, &t);
+    app.auto.add(&format!("effectControls.prop.{uid}.value"), rr.union(dr), &fw::format_angle(*v, 1));
+    app.auto.add(&format!("effectControls.prop.{uid}.revolutions"), rr, &prop.name);
+    if let Some(nv) = nv {
+        cx.set(actions, json!(nv));
+    }
+    cx.twirl_open(app, ui);
+}
+
+fn value_scalar(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
+    let Value::Scalar(v) = value else {
+        return;
+    };
+    let PropCx { t, uid, cy, vx, prop, .. } = *cx;
+    let (min, max, dec) = match &prop.ui {
+        ParamUi::Slider { min, max, decimals, .. } => (*min, *max, *decimals as usize),
+        _ => (-1e9, 1e9, 1),
+    };
+    let suffix = match prop.ui {
+        ParamUi::Percent => "%",
+        _ => "",
+    };
+    let speed = widgets::slider_scrub_speed(&prop.ui);
+    let (vr, nv, _) = widgets::hot_number_at(
+        ui,
+        pos2(vx, cy - 9.0),
+        egui::Id::unique(("ec-v", uid)),
+        *v,
+        &widgets::HotSpec { speed, range: (min, max), decimals: dec.max(if dec == 0 { 0 } else { 1 }), suffix },
+        &t,
+    );
+    app.auto.add(&format!("effectControls.prop.{uid}.value"), vr, &prop.name);
+    if let Some(nv) = nv {
+        cx.set(actions, json!(nv));
+    }
+    // AE hides a slider param's slider until its twirl is opened (see `slider_row`).
+    if matches!(prop.ui, ParamUi::Slider { .. }) {
+        cx.twirl_open(app, ui);
+    }
+}
+
+fn value_vector(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) -> Vec<Rect> {
+    let mut dims = vec![];
+    let PropCx { t, uid, cy, vx, layer, prop, .. } = *cx;
+    let c = value.components();
+    let n = shown_dims(layer, prop, value);
+    let mut x = vx;
+    if matches!(prop.ui, ParamUi::Point | ParamUi::Point3) {
+        let cr = Rect::from_center_size(pos2(x + 8.0, cy), vec2(18.0, 18.0));
+        let active = app.ui.fx_pick.as_ref().is_some_and(|k| k.prop == uid && k.kind == "point");
+        if fw::crosshair_button(ui, cr, active, egui::Id::unique(("ec-xh", uid)), &t)
+            .on_hover_text(crate::i18n::tr("Click, then click in the Composition panel"))
+            .clicked()
+        {
+            toggle_pick(app, "point", layer, prop);
+        }
+        app.auto.add(&format!("effectControls.prop.{uid}.crosshair"), cr, &prop.name);
+        x += 22.0;
+    }
+    for d in 0..n.min(c.len()) {
+        let (vr, nv, _) = widgets::hot_number_at(
+            ui,
+            pos2(x, cy - 9.0),
+            egui::Id::unique(("ec-v", uid, d)),
+            c[d],
+            &widgets::HotSpec { speed: 1.0, range: (-1e9, 1e9), decimals: 1, suffix: "" },
+            &t,
+        );
+        app.auto.add(&format!("effectControls.prop.{uid}.value.{d}"), vr, &prop.name);
+        dims.push(vr);
+        if let Some(nv) = nv {
+            let mut nc = c.clone();
+            nc[d] = nv;
+            cx.set(actions, json!(nc));
+            // Typed into this component only: other selected layers keep the rest of
+            // their own value (#1434).
+            if let Some((_, a)) = actions.last_mut() {
+                a["dims"] = json!([d]);
+            }
+        }
+        x = vr.max.x + 8.0;
+    }
+    dims
+}
+
+fn value_color(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
+    let Value::Color(c) = value else {
+        return;
+    };
+    let PropCx { t, uid, cy, vx, layer, prop, .. } = *cx;
+    let sr = Rect::from_min_size(pos2(vx, cy - 8.0), vec2(30.0, 16.0));
+    let pop = egui::Id::unique(("ec-cpop", uid));
+    if widgets::swatch(ui, sr, [c[0] as f32, c[1] as f32, c[2] as f32, 1.0], egui::Id::unique(("ec-c", uid)), &t).clicked() {
+        widgets::open_popup(ui, pop);
+    }
+    app.auto.add(&format!("effectControls.prop.{uid}.value"), sr, &prop.name);
+    let er = Rect::from_center_size(pos2(sr.max.x + 14.0, cy), vec2(18.0, 18.0));
+    let active = app.ui.fx_pick.as_ref().is_some_and(|k| k.prop == uid && k.kind == "color");
+    if fw::eyedropper_button(ui, er, active, egui::Id::unique(("ec-eye", uid)), &t)
+        .on_hover_text(crate::i18n::tr("Eyedropper: click, then click in the Composition panel"))
+        .clicked()
+    {
+        toggle_pick(app, "color", layer, prop);
+    }
+    app.auto.add(&format!("effectControls.prop.{uid}.eyedropper"), er, &prop.name);
+    let mut rgb = [c[0] as f32, c[1] as f32, c[2] as f32];
+    if crate::widgets::color_popup(ui, pop, sr.left_bottom(), &mut rgb) {
+        cx.set(actions, json!([rgb[0], rgb[1], rgb[2], 1.0]));
+    }
+}
+
+fn value_toggle(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
+    let Value::Bool(b) = value else {
+        return;
+    };
+    let PropCx { t, uid, cy, vx, p, prop, .. } = *cx;
+    let cr = Rect::from_min_size(pos2(vx, cy - 8.0), vec2(16.0, 16.0));
+    if widgets::checkbox(ui, cr, *b, &t, egui::Id::unique(("ec-b", uid))).clicked() {
+        cx.set(actions, json!(!b));
+    }
+    p.text(pos2(cr.max.x + 6.0, cy), Align2::LEFT_CENTER, &prop.name, Tokens::ui(12.0), t.text_dim);
+    app.auto.add(&format!("effectControls.prop.{uid}.value"), cr, &prop.name);
+}
+
+fn value_popup(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
+    let Value::Enum(i) = value else {
+        return;
+    };
+    let PropCx { t, uid, cy, vx, r, p, prop, .. } = *cx;
+    if let ParamUi::Popup { options } = &prop.ui {
+        let widest = options.iter().map(|o| p.layout_no_wrap(o.clone(), Tokens::ui(11.5), t.text).size().x).fold(0.0, f32::max);
+        let dr = Rect::from_min_size(pos2(vx, cy - 9.0), vec2((widest + 30.0).clamp(80.0, (r.max.x - vx - 56.0).max(80.0)), 18.0));
+        let pop = egui::Id::unique(("ec-epop", uid));
+        if widgets::dropdown(ui, dr, options.get(*i as usize).map(String::as_str).unwrap_or(""), &t, egui::Id::unique(("ec-e", uid))).clicked() {
+            widgets::open_popup(ui, pop);
+        }
+        app.auto.add(&format!("effectControls.prop.{uid}.value"), dr, &prop.name);
+        if let Some(ni) = widgets::popup_menu(ui, pop, dr.left_bottom(), options, Some(*i as usize)) {
+            cx.set(actions, json!(ni));
+        }
+    }
+}
+
+fn value_layer_ref(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
+    let Value::Layer(l) = value else {
+        return;
+    };
+    let PropCx { t, uid, cy, vx, r, layer, prop, group, .. } = *cx;
+    let comp = app.session.active_comp_arc();
+    if let Some(comp) = comp {
+        let dr = Rect::from_min_size(pos2(vx, cy - 9.0), vec2(((r.max.x - vx) * 0.55).clamp(90.0, 170.0), 18.0));
+        if let Some(chosen) = widgets::layer_picker(ui, dr, &comp.layers, *l, &t, egui::Id::unique(("ec-l", uid))) {
+            cx.set(actions, chosen.map(|id| json!(id)).unwrap_or(serde_json::Value::Null));
+        }
+        app.auto.add(&format!("effectControls.prop.{uid}.value"), dr, &prop.name);
+        // Source / Masks / Effects & Masks (the hidden companion parameter).
+        if let Some(src) = group.get(&effectcraft_engine::effects::layer_source_id(&prop.match_id)) {
+            let si = src.value.as_enum() as usize;
+            let opts: Vec<String> = effectcraft_engine::effects::LAYER_SOURCE_OPTIONS.iter().map(|s| s.to_string()).collect();
+            let sr = Rect::from_min_size(pos2(dr.max.x + 6.0, cy - 9.0), vec2(((r.max.x - dr.max.x) - 64.0).clamp(70.0, 120.0), 18.0));
+            let spop = egui::Id::unique(("ec-lspop", uid));
+            if widgets::dropdown(ui, sr, opts.get(si).map(String::as_str).unwrap_or(""), &t, egui::Id::unique(("ec-ls", uid))).clicked() {
+                widgets::open_popup(ui, spop);
+            }
+            app.auto.add(&format!("effectControls.prop.{uid}.source"), sr, &src.name);
+            if let Some(ni) = widgets::popup_menu(ui, spop, sr.left_bottom(), &opts, Some(si)) {
+                actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": src.uid, "value": ni})));
+            }
+        }
+    }
+}
+
+fn value_extractor(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
+    let Value::Str(s) = value else {
+        return;
+    };
+    let PropCx { cy, vx, r, layer, prop, .. } = *cx;
+    let dr = Rect::from_min_size(pos2(vx, cy - 9.0), vec2((r.max.x - vx - 56.0).clamp(80.0, 200.0), 18.0));
+    crate::panels::fx_editors::channel_popup(app, ui, layer, prop, s, dr, actions);
+}
+
+fn value_file(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
+    let Value::Str(s) = value else {
+        return;
+    };
+    let PropCx { t, uid, cy, vx, r, p, layer, prop, .. } = *cx;
+    let bw = 70.0;
+    let br = Rect::from_min_size(pos2(vx, cy - 9.0), vec2(bw, 18.0));
+    if widgets::text_button(ui, br, crate::i18n::tr("Choose..."), false, &t, egui::Id::unique(("ec-file", uid))).clicked() {
+        let filters: Vec<&str> = match &prop.ui {
+            ParamUi::File { filters } => filters.iter().map(String::as_str).collect(),
+            _ => vec![],
+        };
+        match app.hooks.pick_files.as_ref() {
+            Some(pick) => {
+                if let Some(path) = pick(&filters).into_iter().next() {
+                    actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": uid, "value": path})));
+                }
+            }
+            None => app.ui.status = "no file dialog available: set the path with prop.set".into(),
+        }
+    }
+    app.auto.add(&format!("effectControls.prop.{uid}.choose"), br, &prop.name);
+    let shown = if s.trim().is_empty() {
+        crate::i18n::tr("None").to_string()
+    } else if s.contains('\n') {
+        prop.name.clone()
+    } else {
+        effectcraft_engine::sequence::file_name(s)
+    };
+    let nr = Rect::from_min_max(pos2(br.max.x + 8.0, r.min.y), pos2(r.max.x - 8.0, r.max.y));
+    let np = p.with_clip_rect(nr.intersect(p.clip_rect()));
+    np.text(pos2(nr.min.x, cy), Align2::LEFT_CENTER, &shown, Tokens::ui(12.0), if s.trim().is_empty() { t.text_dim } else { t.text });
+    let hover = ui.interact(nr, egui::Id::unique(("ec-file-name", uid)), Sense::hover());
+    if !s.trim().is_empty() && !s.contains('\n') {
+        hover.on_hover_text(s);
+    }
+    app.auto.add(&format!("effectControls.prop.{uid}.value"), nr, &shown);
+}
+
+fn value_text(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
+    let Value::Str(s) = value else {
+        return;
+    };
+    let PropCx { t, uid, cy, vx, r, layer, prop, .. } = *cx;
+    let fr = Rect::from_min_size(pos2(vx, cy - 9.0), vec2((r.max.x - vx - 12.0).clamp(80.0, 320.0), 18.0));
+    let bid = egui::Id::unique(("ec-text", uid));
+    let mut buf: String = ui.data(|d| d.get_temp(bid)).unwrap_or_else(|| s.to_owned());
+    let resp = widgets::text_field(ui, fr, &mut buf, "", &t);
+    // The field has no visible hint: give the screen reader the parameter's name.
+    resp.widget_info(|| egui::WidgetInfo::labeled(egui::Role::TextInput, ui.is_enabled(), &prop.name));
+    app.auto.add(&format!("effectControls.prop.{uid}.value"), fr, &prop.name);
+    if resp.lost_focus() {
+        if buf != *s && !ui.input(|i| i.key_pressed(egui::Key::Escape)) {
+            actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": uid, "value": buf})));
+        }
+        ui.data_mut(|d| d.remove::<String>(bid));
+    } else if resp.has_focus() {
+        ui.data_mut(|d| d.insert_temp(bid, buf));
+    }
+}
+
+fn value_gradient(app: &mut EffectcraftApp, cx: &PropCx, value: &Value) {
+    let Value::Gradient(g) = value else {
+        return;
+    };
+    let PropCx { t, uid, cy, vx, r, p, prop, .. } = *cx;
+    let gr = Rect::from_min_size(pos2(vx, cy - 7.0), vec2((r.max.x - vx - 56.0).clamp(60.0, 180.0), 14.0));
+    let n = 48;
+    for k in 0..n {
+        let f = k as f64 / (n - 1) as f64;
+        let c = gradient_at(g, f);
+        let x0 = gr.min.x + gr.width() * k as f32 / n as f32;
+        let x1 = gr.min.x + gr.width() * (k + 1) as f32 / n as f32;
+        p.rect_filled(Rect::from_min_max(pos2(x0, gr.min.y), pos2(x1, gr.max.y)), 0.0, c);
+    }
+    p.rect_stroke(gr, 2.0, Stroke::new(1.0, t.field_border), egui::StrokeKind::Inside);
+    app.auto.add(&format!("effectControls.prop.{uid}.value"), gr, &prop.name);
+}
+
+/// How many of a vector parameter's values show (a 3D point's Z only on a 3D layer).
+fn shown_dims(layer: &Layer, prop: &Property, value: &Value) -> usize {
+    let n = value.components().len();
+    if prop.shown_dims > 0 && !(layer.is_3d() && n == 3) { prop.shown_dims as usize } else { n }
+}
+
+/// Colour of a gradient at `f` (colour stops only).
+fn gradient_at(g: &effectcraft_engine::keyframe::Gradient, f: f64) -> Color32 {
+    let stops = &g.colors;
+    let c = if stops.is_empty() {
+        [0.0, 0.0, 0.0, 1.0]
+    } else if f <= stops[0].0 {
+        stops[0].1
+    } else if f >= stops[stops.len() - 1].0 {
+        stops[stops.len() - 1].1
+    } else {
+        let i = stops.iter().position(|s| s.0 > f).unwrap_or(stops.len() - 1).max(1);
+        let (a, b) = (stops[i - 1], stops[i]);
+        let k = ((f - a.0) / (b.0 - a.0).max(1e-9)) as f32;
+        [0, 1, 2, 3].map(|j| a.1[j] + (b.1[j] - a.1[j]) * k)
+    };
+    Color32::from_rgb((c[0].clamp(0.0, 1.0) * 255.0) as u8, (c[1].clamp(0.0, 1.0) * 255.0) as u8, (c[2].clamp(0.0, 1.0) * 255.0) as u8)
+}
+
+/// The twirled-open slider under a slider param: track, knob and the slider range's ends.
+#[allow(clippy::too_many_arguments)]
+fn slider_row(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    p: &egui::Painter,
+    layer: &Layer,
+    prop: &Property,
+    ectx: &EvalCtx,
+    r: Rect,
+    x0: f32,
+    actions: &mut Actions,
+) {
+    let t = app.tokens;
+    let ParamUi::Slider { slider_min, slider_max, decimals, .. } = prop.ui else { return };
+    let Value::Scalar(v) = ectx.value(layer, prop) else { return };
+    let uid = prop.uid;
+    let tr = Rect::from_min_max(pos2(r.min.x + x0, r.min.y + 8.0), pos2(r.max.x - 16.0, r.min.y + 12.0));
+    if tr.width() < 40.0 {
+        return;
+    }
+    p.rect_filled(tr, 2.0, t.field_bg);
+    let f = ((v - slider_min) / (slider_max - slider_min)).clamp(0.0, 1.0) as f32;
+    p.rect_filled(Rect::from_min_max(tr.min, pos2(tr.min.x + tr.width() * f, tr.max.y)), 2.0, t.accent.gamma_multiply(0.7));
+    p.circle_filled(pos2(tr.min.x + tr.width() * f, tr.center().y), 5.0, t.text);
+    let dec = decimals as usize;
+    p.text(pos2(tr.min.x, tr.max.y + 4.0), Align2::LEFT_TOP, format!("{slider_min:.dec$}"), Tokens::ui(10.5), t.text_dim);
+    p.text(pos2(tr.max.x, tr.max.y + 4.0), Align2::RIGHT_TOP, format!("{slider_max:.dec$}"), Tokens::ui(10.5), t.text_dim);
+    let sresp = ui.interact(tr.expand2(vec2(4.0, 6.0)), egui::Id::unique(("ec-slider", uid)), Sense::click_and_drag());
+    app.auto.add(&format!("effectControls.prop.{uid}.slider"), tr, &prop.name);
+    if (sresp.dragged() || sresp.clicked())
+        && let Some(pt) = sresp.interact_pointer_pos()
+    {
+        let f = ((pt.x - tr.min.x) / tr.width()).clamp(0.0, 1.0) as f64;
+        actions.push((
+            "prop.set".into(),
+            json!({"layer": layer.id.0, "prop": uid, "value": slider_min + (slider_max - slider_min) * f, "merge": format!("ec-{uid}")}),
+        ));
+    }
+}
+
+/// The twirled-open angle dial under an angle param.
+#[allow(clippy::too_many_arguments)]
+fn dial_row(app: &mut EffectcraftApp, ui: &mut egui::Ui, layer: &Layer, prop: &Property, ectx: &EvalCtx, r: Rect, x0: f32, actions: &mut Actions) {
+    let t = app.tokens;
+    let Value::Scalar(v) = ectx.value(layer, prop) else { return };
+    let uid = prop.uid;
+    let d = (r.height() - 12.0).min(52.0);
+    let dr = Rect::from_min_size(pos2(r.min.x + x0 + 40.0, r.min.y + 6.0), vec2(d, d));
+    let id = egui::Id::unique(("ec-dial", uid));
+    let (resp, nv) = fw::angle_dial(ui, dr, v, id, &t);
+    app.auto.add(&format!("effectControls.prop.{uid}.dial"), dr, &prop.name);
+    if let Some(nv) = nv {
+        let key = gesture_key(ui, id, resp.drag_started() || resp.clicked());
+        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": uid, "value": nv, "merge": key})));
+    }
+}
+
+/// The effect instance a row belongs to, for conditional visibility
+/// ([`effectcraft_engine::effects::catalog::param_shown`]): effect id, the instance's root
+/// group and the spec-id path of the group being drawn (`""` or `cameraPosition/`).
+pub(super) struct FxScope<'a> {
+    pub(super) effect: &'a str,
+    pub(super) root: &'a PropGroup,
+    pub(super) path: String,
+}
+
+impl<'a> FxScope<'a> {
+    pub(super) fn sub(&self, m: &str) -> FxScope<'a> {
+        FxScope { effect: self.effect, root: self.root, path: format!("{}{m}/", self.path) }
+    }
+    /// Whether child `m` of the current group is shown.
+    pub(super) fn shown(&self, layer: &Layer, ectx: &EvalCtx, m: &str) -> bool {
+        let root = self.root;
+        let value = |id: &str| -> Option<Value> {
+            let mut g = root;
+            let mut parts = id.split('/').peekable();
+            while let Some(part) = parts.next() {
+                if parts.peek().is_none() {
+                    return g.get(part).map(|p| ectx.value(layer, p));
+                }
+                g = g.sub(part)?;
+            }
+            None
+        };
+        effectcraft_engine::effects::catalog::param_shown(self.effect, &format!("{}{m}", self.path), &value)
+    }
+}
+
+/// Twirl `g` closed (it was `open`) or open; with `all` (Alt/Cmd-click) every group under it follows.
+pub(super) fn toggle_closed(app: &mut EffectcraftApp, g: &PropGroup, open: bool, all: bool) {
+    fn walk(g: &PropGroup, out: &mut Vec<u64>) {
+        for sg in g.groups() {
+            out.push(sg.uid);
+            walk(sg, out);
+        }
+    }
+    let mut uids = vec![g.uid];
+    if all {
+        walk(g, &mut uids);
+    }
+    for u in uids {
+        if open {
+            app.ui.fx_closed.insert(u);
+        } else {
+            app.ui.fx_closed.remove(&u);
+        }
+    }
+}
+
+/// Lays out one property group's rows below `*y` (which it advances), recursing into open
+/// subgroups: one row per visible property with its controls, plus the dial or slider row when its
+/// slider is open, and an inline editor for groups that have one. Rows scrolled out of `rect` are
+/// skipped without being drawn or registered, though their height is still counted. Pick-whip
+/// drops are registered for each visible property; edits go on `actions`.
+#[allow(clippy::too_many_arguments)]
+pub(super) fn group_rows(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    p: &egui::Painter,
+    layer: &Layer,
+    g: &PropGroup,
+    ectx: &EvalCtx,
+    rect: Rect,
+    y: &mut f32,
+    depth: usize,
+    fx: &FxScope,
+    actions: &mut Actions,
+) {
+    let t = app.tokens;
+    for c in &g.children {
+        let r = Rect::from_min_size(pos2(rect.min.x, *y), vec2(rect.width(), ROW));
+        match c {
+            Node::Prop(pr) => {
+                if matches!(pr.ui, ParamUi::Hidden) || pr.three_d_only && !layer.is_3d() || !fx.shown(layer, ectx, &pr.match_id) {
+                    continue;
+                }
+                *y += ROW;
+                let indent = PARAM_NAME_X - 13.0 + TREE_INDENT * depth as f32;
+                let visible = !(r.max.y < rect.min.y || r.min.y > rect.max.y);
+                if visible {
+                    app.auto.add(&format!("effectControls.row.{}", pr.uid), r, &pr.name);
+                    let dims = prop_row(app, ui, p, layer, g, pr, ectx, r, indent, actions);
+                    // A Timeline pick whip can be dropped here (After Effects).
+                    crate::panels::timeline::whip_target(ui.ctx(), r.intersect(rect), layer.id.0, pr.uid, dims);
+                }
+                if app.ui.fx_slider_open.contains(&pr.uid) {
+                    if matches!(pr.ui, ParamUi::Angle) {
+                        let sr = Rect::from_min_size(pos2(rect.min.x, *y), vec2(rect.width(), DIAL_ROW));
+                        *y += DIAL_ROW;
+                        if sr.max.y >= rect.min.y && sr.min.y <= rect.max.y {
+                            dial_row(app, ui, layer, pr, ectx, sr, indent + 22.0, actions);
+                        }
+                    } else if matches!(pr.ui, ParamUi::Slider { .. }) {
+                        let sr = Rect::from_min_size(pos2(rect.min.x, *y), vec2(rect.width(), 34.0));
+                        *y += 34.0;
+                        if sr.max.y >= rect.min.y && sr.min.y <= rect.max.y {
+                            slider_row(app, ui, p, layer, pr, ectx, sr, indent + 22.0, actions);
+                        }
+                    }
+                }
+            }
+            Node::Group(sg) => {
+                // Paint strokes live in the Timeline only (AE's Paint shows Paint on Transparent).
+                if effectcraft_engine::effects::paint::is_paint(g) || !fx.shown(layer, ectx, &sg.match_id) {
+                    continue;
+                }
+                *y += ROW;
+                let open = !app.ui.fx_closed.contains(&sg.uid);
+                let tw = Rect::from_center_size(pos2(r.min.x + PARAM_NAME_X - 12.0 + TREE_INDENT * depth as f32, r.center().y), vec2(12.0, 12.0));
+                if r.max.y >= rect.min.y && r.min.y <= rect.max.y {
+                    app.auto.add(&format!("effectControls.row.{}", sg.uid), r, &sg.name);
+                    app.auto.add(&format!("effectControls.group.{}.twirl", sg.uid), tw, &sg.name);
+                    if widgets::twirl(ui, tw, open, egui::Id::unique(("ec-g", sg.uid)), &t).clicked() {
+                        toggle_closed(app, sg, open, ui.input(|i| i.modifiers.alt || i.modifiers.command));
+                    }
+                    let name = p.text(pos2(tw.max.x + 6.0, r.center().y), Align2::LEFT_CENTER, &sg.name, Tokens::ui(12.0), t.text);
+                    app.auto.add(&format!("effectControls.group.{}.name", sg.uid), name, &sg.name);
+                }
+                if open {
+                    let sub = fx.sub(&sg.match_id);
+                    // A visual editor for the group's hidden parameters (Lumetri curves, …).
+                    let eh = crate::panels::fx_editors::inline_height(fx.effect, &sub.path, rect.width());
+                    if eh > 0.0 {
+                        let er = Rect::from_min_size(pos2(rect.min.x, *y), vec2(rect.width(), eh));
+                        *y += eh;
+                        if er.max.y >= rect.min.y && er.min.y <= rect.max.y {
+                            crate::panels::fx_editors::inline_editor(app, ui, p, layer, fx.root, sg, fx.effect, &sub.path, ectx, er, actions);
+                        }
+                    }
+                    group_rows(app, ui, p, layer, sg, ectx, rect, y, depth + 1, &sub, actions);
+                }
+            }
+        }
+    }
+}
diff --git a/crates/ui-egui/src/panels/effect_controls/viewer.rs b/crates/ui-egui/src/panels/effect_controls/viewer.rs
new file mode 100644
index 000000000..b11b63a35
--- /dev/null
+++ b/crates/ui-egui/src/panels/effect_controls/viewer.rs
@@ -0,0 +1,295 @@
+use std::ops::ControlFlow;
+
+use super::common::{Actions, effect_active, gesture_key};
+use super::rows::FxScope;
+use super::{
+    Align2, Color32, EffectcraftApp, EvalCtx, GroupKind, Layer, Mat3, Node, ParamUi, PropGroup, Property, Rect, Sense, Stroke, Tokens, fw, json, vec2,
+};
+
+// ---------------------------------------------------------------------------------------------
+// Viewer hook
+
+/// Collect point controls through visible parameter groups. Hidden optional slots do not
+/// leave stray viewport handles. The depth cap also bounds malformed project trees.
+fn visible_points<'a>(g: &'a PropGroup, scope: &FxScope<'_>, layer: &Layer, ectx: &EvalCtx, depth: usize, out: &mut Vec<&'a Property>) {
+    if depth > 16 {
+        return;
+    }
+    for node in &g.children {
+        match node {
+            Node::Prop(p) if matches!(p.ui, ParamUi::Point) && scope.shown(layer, ectx, &p.match_id) => out.push(p),
+            Node::Group(child) if child.enabled && scope.shown(layer, ectx, &child.match_id) => {
+                visible_points(child, &scope.sub(&child.match_id), layer, ectx, depth + 1, out)
+            }
+            _ => {}
+        }
+    }
+}
+
+/// An armed crosshair / eyedropper pick: the hint chip, the cursor preview, and the click that
+/// sets or samples. `Break` when the picked layer is gone; `Continue` carries the point preview.
+fn fx_pick_session(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    painter: &egui::Painter,
+    map: &crate::panels::viewer::ViewerMap,
+    ectx: &EvalCtx,
+    l2c: &dyn Fn(&EvalCtx, &Layer) -> Mat3,
+    actions: &mut Actions,
+) -> ControlFlow<(), Option<egui::Pos2>> {
+    let t = app.tokens;
+    let ctx = ui.ctx().clone();
+    let mut point_preview = None;
+    let Some(pick) = app.ui.fx_pick.clone() else {
+        return ControlFlow::Continue(None);
+    };
+    let Some(layer) = ectx.comp.layer(effectcraft_engine::project::LayerId(pick.layer)).cloned() else {
+        app.ui.fx_pick = None;
+        return ControlFlow::Break(());
+    };
+    // Keyers pick from their input (the shown frame is already keyed): `effect.pickColor`.
+    let keyer = (pick.kind == "color")
+        .then(|| layer.effects()?.groups().find(|g| g.find(pick.prop).is_some()))
+        .flatten()
+        .filter(|g| effectcraft_engine::effects::find(&g.match_id).is_some_and(|s| s.category == "Keying"))
+        .map(|g| g.uid);
+    if pick.kind == "color" && keyer.is_none() {
+        // GPU frames: read the shown frame back for sampling.
+        app.viewer_pixels();
+    }
+    let resp = ui.interact(map.area, egui::Id::unique("viewer-fx-pick"), Sense::click());
+    app.auto.add("viewer.fxPick", map.area, &pick.name);
+    let hint = if pick.kind == "point" { format!("Click to set {}", pick.name) } else { format!("Click to sample {}", pick.name) };
+    let chip = Rect::from_min_size(map.area.min + vec2(10.0, 10.0), vec2(220.0, 22.0));
+    painter.rect_filled(chip, 11.0, Color32::from_black_alpha(180));
+    painter.text(chip.center(), Align2::CENTER_CENTER, hint, Tokens::ui(11.5), t.text);
+    if let Some(hp) = resp.hover_pos() {
+        ctx.set_cursor_icon(egui::CursorIcon::Crosshair);
+        let c = map.to_comp(hp);
+        app.pointer_comp = Some([c[0] as f32, c[1] as f32]);
+        if pick.kind == "point" && fw::comp_to_layer(&l2c(ectx, &layer), c).is_some() {
+            point_preview = Some(hp);
+        }
+        if pick.kind == "color"
+            && keyer.is_none()
+            && let Some(img) = &app.viewer_image
+            && let Some(s) = fw::sample_frame(img, crate::panels::viewer_tools::shown_region(&ctx, map.comp), c)
+        {
+            let sw = Rect::from_min_size(hp + vec2(14.0, 14.0), vec2(26.0, 18.0));
+            painter.rect_filled(sw, 2.0, Color32::from_rgb((s[0] * 255.0) as u8, (s[1] * 255.0) as u8, (s[2] * 255.0) as u8));
+            painter.rect_stroke(sw, 2.0, Stroke::new(1.0, Color32::WHITE), egui::StrokeKind::Outside);
+        }
+    }
+    // No frame to sample yet (it is still rendering, or its readback is pending): the click
+    // leaves the eyedropper armed instead of using it up without a colour.
+    let unsampled = pick.kind == "color" && keyer.is_none() && app.viewer_image.is_none();
+    if resp.clicked()
+        && !unsampled
+        && let Some(pos) = resp.interact_pointer_pos()
+    {
+        let c = map.to_comp(pos);
+        // Effect points and the keyer's input are in effect space.
+        let m = crate::panels::viewer::from_effect_space(ectx, &layer, l2c(ectx, &layer));
+        if pick.kind == "point" {
+            if let Some(lp) = fw::comp_to_layer(&m, c) {
+                actions.push(("prop.set".into(), json!({"layer": pick.layer, "prop": pick.prop, "value": [lp[0], lp[1]]})));
+            }
+        } else if let Some(fx) = keyer {
+            // Ctrl/Cmd+click averages the 5 × 5 pixels around the point.
+            if let Some(lp) = fw::comp_to_layer(&m, c) {
+                let average = ui.input(|i| i.modifiers.command);
+                actions.push((
+                    "effect.pickColor".into(),
+                    json!({"layer": pick.layer, "effect": fx, "prop": pick.prop, "x": lp[0], "y": lp[1], "average": average}),
+                ));
+            }
+        } else if let Some(img) = &app.viewer_image
+            && let Some(s) = fw::sample_frame(img, crate::panels::viewer_tools::shown_region(&ctx, map.comp), c)
+        {
+            actions.push(("prop.set".into(), json!({"layer": pick.layer, "prop": pick.prop, "value": [s[0], s[1], s[2], 1.0]})));
+        }
+        app.ui.fx_pick = None;
+        app.ui.status.clear();
+    }
+    if ui.input(|i| i.key_pressed(egui::Key::Escape)) {
+        app.ui.fx_pick = None;
+        app.ui.status.clear();
+    }
+
+    ControlFlow::Continue(point_preview)
+}
+
+/// An armed text-colour pick: sample the shown frame on click, Esc cancels.
+fn text_color_pick(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    painter: &egui::Painter,
+    map: &crate::panels::viewer::ViewerMap,
+    ectx: &EvalCtx,
+    actions: &mut Actions,
+) {
+    let t = app.tokens;
+    let ctx = ui.ctx().clone();
+    let Some(pick) = app.ui.text_color_pick.clone() else {
+        return;
+    };
+    if ectx.comp.layer(effectcraft_engine::project::LayerId(pick.layer)).is_none() {
+        app.ui.text_color_pick = None;
+        app.ui.status.clear();
+    } else {
+        app.viewer_pixels();
+        let resp = ui.interact(map.area, egui::Id::unique("viewer-text-color-pick"), Sense::click());
+        app.auto.add("viewer.textColorPick", map.area, &pick.field);
+        let chip = Rect::from_min_size(map.area.min + vec2(10.0, 10.0), vec2(220.0, 22.0));
+        painter.rect_filled(chip, 11.0, Color32::from_black_alpha(180));
+        painter.text(chip.center(), Align2::CENTER_CENTER, crate::i18n::tr_args("Click to sample text {}", &[&pick.field]), Tokens::ui(11.5), t.text);
+        if let Some(pos) = resp.hover_pos() {
+            ctx.set_cursor_icon(egui::CursorIcon::Crosshair);
+            let c = map.to_comp(pos);
+            app.pointer_comp = Some([c[0] as f32, c[1] as f32]);
+            if let Some(img) = &app.viewer_image
+                && let Some(s) = fw::sample_frame(img, crate::panels::viewer_tools::shown_region(&ctx, map.comp), c)
+            {
+                let sw = Rect::from_min_size(pos + vec2(14.0, 14.0), vec2(26.0, 18.0));
+                painter.rect_filled(sw, 2.0, Color32::from_rgb((s[0] * 255.0) as u8, (s[1] * 255.0) as u8, (s[2] * 255.0) as u8));
+                painter.rect_stroke(sw, 2.0, Stroke::new(1.0, Color32::WHITE), egui::StrokeKind::Outside);
+            }
+        }
+        if resp.clicked()
+            && let Some(pos) = resp.interact_pointer_pos()
+            && let Some(img) = &app.viewer_image
+            && let Some(s) = fw::sample_frame(img, crate::panels::viewer_tools::shown_region(&ctx, map.comp), map.to_comp(pos))
+        {
+            let mut params = json!({"layer": pick.layer});
+            params[&pick.field] = json!([s[0], s[1], s[2]]);
+            if let Some(range) = pick.range {
+                params["range"] = json!(range);
+            }
+            actions.push(("layer.setText".into(), params));
+            app.ui.text_color_pick = None;
+            app.ui.status.clear();
+        }
+        if ui.input(|i| i.key_pressed(egui::Key::Escape)) {
+            app.ui.text_color_pick = None;
+            app.ui.status.clear();
+        }
+    }
+}
+
+/// Effect Controls' part of the Composition viewer, called by the viewer after its own
+/// interaction (so these controls sit on top):
+///
+/// - while a crosshair pick is armed, its handle previews the cursor position without editing
+///   the property; the next click sets the point in layer space, and Esc cancels;
+/// - an eyedropper pick samples the frame's colour on click;
+/// - otherwise, the point parameters of the selected effects are drawn as draggable ⊕ controls.
+///
+/// `l2c` is the viewer's layer→comp matrix (it knows the 3D view).
+pub fn viewer_hook(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    painter: &egui::Painter,
+    map: &crate::panels::viewer::ViewerMap,
+    ectx: &EvalCtx,
+    l2c: &dyn Fn(&EvalCtx, &Layer) -> Mat3,
+) {
+    let t = app.tokens;
+    let ctx = ui.ctx().clone();
+    let mut actions: Actions = vec![];
+    let point_preview = match fx_pick_session(app, ui, painter, map, ectx, l2c, &mut actions) {
+        ControlFlow::Break(()) => return,
+        ControlFlow::Continue(p) => p,
+    };
+    text_color_pick(app, ui, painter, map, ectx, &mut actions);
+    let picking = app.ui.fx_pick.is_some() || app.ui.text_color_pick.is_some();
+    let point_pick = app.ui.fx_pick.clone().filter(|p| p.kind == "point");
+    if app.ui.viewer.show_layer_controls || point_pick.is_some() {
+        // ⊕ controls for the point parameters of the selected effects.
+        let mut sel = app.session.state.selected_props.clone();
+        if let Some(pick) = &point_pick {
+            sel.push((effectcraft_engine::project::LayerId(pick.layer), pick.prop));
+        }
+        let selected = app.session.state.selected_layers.clone();
+        for layer in ectx
+            .comp
+            .layers
+            .iter()
+            .filter(|l| (selected.contains(&l.id) || point_pick.as_ref().is_some_and(|p| p.layer == l.id.0)) && l.is_active_at(ectx.time))
+        {
+            let Some(fx) = layer.effects() else { continue };
+            let m = l2c(ectx, layer);
+            // Masks are in layer space, effect points in effect space.
+            let fm = crate::panels::viewer::from_effect_space(ectx, layer, m);
+            let picked_prop = point_pick.as_ref().filter(|p| p.layer == layer.id.0).map(|p| p.prop);
+            for g in fx.groups().filter(|g| g.enabled && effect_active(g, layer.id, &sel)) {
+                // Puppet owns its pin handles and hit testing. Generic crosshairs would
+                // overlap the pins and steal their selection/rotation/scale gestures.
+                if matches!(&g.kind, GroupKind::Effect { effect } if effect == effectcraft_engine::effects::puppet::ID) {
+                    continue;
+                }
+                if !picking
+                    && app.ui.viewer.show_layer_controls
+                    && matches!(&g.kind, GroupKind::Effect { effect } if effect == crate::panels::fx_editors::RESHAPE)
+                {
+                    crate::panels::fx_editors::reshape_overlay(app, ui, painter, map, ectx, layer, g, &m, &mut actions);
+                }
+                if !picking
+                    && app.ui.viewer.show_layer_controls
+                    && matches!(&g.kind, GroupKind::Effect { effect } if effect == crate::panels::fx_editors::MESH_WARP)
+                {
+                    crate::panels::fx_editors::mesh_warp_overlay(app, ui, painter, map, ectx, layer, g, &fm, &mut actions);
+                }
+                let scope = FxScope { effect: &g.match_id, root: g, path: String::new() };
+                let mut pts = Vec::new();
+                visible_points(g, &scope, layer, ectx, 0, &mut pts);
+                // An explicit pick stays visible even when View > Show Layer Controls is off.
+                if !app.ui.viewer.show_layer_controls {
+                    pts.retain(|pr| picked_prop == Some(pr.uid));
+                }
+                let screen: Vec<egui::Pos2> = pts
+                    .iter()
+                    .map(|pr| {
+                        if picked_prop == Some(pr.uid)
+                            && let Some(pos) = point_preview
+                        {
+                            return pos;
+                        }
+                        let v = ectx.value(layer, pr).as_vec2();
+                        map.to_screen(fw::layer_to_comp(&fm, v))
+                    })
+                    .collect();
+                // Gradient Ramp and friends: a guide between start and end points.
+                if screen.len() == 2 && matches!(&g.kind, GroupKind::Effect { effect } if effect.contains("gradient") || effect.contains("ramp")) {
+                    painter.line_segment([screen[0], screen[1]], Stroke::new(1.0, Color32::from_white_alpha(110)));
+                }
+                for (pr, s) in pts.iter().zip(screen) {
+                    let hr = Rect::from_center_size(s, vec2(16.0, 16.0));
+                    let id = egui::Id::unique(("viewer-fx-pt", pr.uid));
+                    // The picker owns the click. Preview handles must not steal it or start a drag.
+                    let resp = (!picking).then(|| ui.interact(hr, id, Sense::drag()));
+                    let col = if picked_prop == Some(pr.uid) || resp.as_ref().is_some_and(|r| r.hovered() || r.dragged()) { t.accent } else { Color32::WHITE };
+                    fw::draw_crosshair(painter, s + vec2(1.0, 1.0), 5.0, Color32::from_black_alpha(160));
+                    fw::draw_crosshair(painter, s, 5.0, col);
+                    app.auto.add(&format!("viewer.effectPoint.{}", pr.uid), hr, &pr.name);
+                    let Some(resp) = resp else { continue };
+                    if resp.hovered() {
+                        ctx.set_cursor_icon(egui::CursorIcon::Move);
+                        resp.clone().on_hover_text(format!("{}: {}", crate::i18n::effects::group(&g.match_id, &g.name), pr.name));
+                    }
+                    if resp.dragged()
+                        && let Some(pos) = resp.interact_pointer_pos()
+                        && let Some(lp) = fw::comp_to_layer(&fm, map.to_comp(pos))
+                    {
+                        let key = gesture_key(ui, id, resp.drag_started());
+                        actions.push(("prop.set".into(), json!({"layer": layer.id.0, "prop": pr.uid, "value": [lp[0], lp[1]], "merge": key})));
+                    }
+                }
+            }
+        }
+    }
+    for (id, params) in actions {
+        if let Err(e) = crate::menus::invoke(app, &ctx, &id, params) {
+            app.ui.status = e;
+        }
+    }
+}
diff --git a/crates/ui-egui/src/panels/effects_presets.rs b/crates/ui-egui/src/panels/effects_presets.rs
index fa7d2ac40..380d1d869 100644
--- a/crates/ui-egui/src/panels/effects_presets.rs
+++ b/crates/ui-egui/src/panels/effects_presets.rs
@@ -264,32 +264,13 @@ fn user_presets(ctx: &egui::Context, force: bool, scan: impl FnOnce() -> Vec<Pre
     v
 }
 
-/// The Effects & Presets panel: search, a contents menu (colour-depth and GPU filters, whether
-/// presets show, categories or one alphabetical list, refresh and clear of the recently used
-/// list), then Favourites, Recently Used, Animation Presets and the effects by category or
-/// alphabetically, filtered by the query. Picking an effect or preset applies it to the selection
-/// (`effect.apply` or the preset's own command); applying an effect also records it as recently
-/// used and opens Effect Controls. Without a selected layer it only reports that in
-/// `app.ui.status`.
-pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
-    let t = app.tokens;
-    let ctx = ui.ctx().clone();
-    let p = ui.painter().clone();
-    // Track the last applied effect (menus, drag and drop, the control channel) as recently used.
-    if let Some(last) = app.session.state.last_effect.clone()
-        && app.ui.effects_recent.first() != Some(&last)
-    {
-        push_recent(&mut app.ui.effects_recent, &last);
-    }
-    let sr = Rect::from_min_size(rect.min + vec2(8.0, 8.0), vec2(rect.width() - 44.0, 24.0));
-    let mut q = app.ui.effects_search.clone();
-    widgets::search_field(ui, sr, &mut q, "Search effects and presets", &t);
-    app.ui.effects_search = q.clone();
-    app.auto.add("effects.search", sr, "Search");
+/// The "Effects & Presets options" hamburger menu beside the search field; returns whether
+/// "Refresh List" was picked.
+fn contents_menu(app: &mut EffectcraftApp, ui: &mut egui::Ui, ctx: &egui::Context, rect: Rect, sr: Rect, t: &Tokens) -> bool {
     // Contents menu.
     let mr = Rect::from_center_size(pos2(rect.max.x - 18.0, sr.center().y), vec2(22.0, 22.0));
     let mpop = egui::Id::unique("fx-contents-menu");
-    if widgets::icon_button(ui, mr, Icon::Hamburger, false, &t, egui::Id::unique("fx-menu")).on_hover_text(tr("Effects & Presets options")).clicked() {
+    if widgets::icon_button(ui, mr, Icon::Hamburger, false, t, egui::Id::unique("fx-menu")).on_hover_text(tr("Effects & Presets options")).clicked() {
         widgets::open_popup(ui, mpop);
     }
     app.auto.add("effects.menu", mr, "Effects & Presets options");
@@ -339,7 +320,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         let v = &mut app.ui.effects_view;
         match i {
             i if menu.get(i) == Some(&copy_label) => {
-                if let Err(e) = crate::menus::invoke(app, &ctx, "effects.copyPresetsFolderPath", json!({})) {
+                if let Err(e) = crate::menus::invoke(app, ctx, "effects.copyPresetsFolderPath", json!({})) {
                     app.ui.status = e;
                 }
             }
@@ -354,6 +335,32 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             _ => {}
         }
     }
+    force_scan
+}
+
+/// The Effects & Presets panel: search, a contents menu (colour-depth and GPU filters, whether
+/// presets show, categories or one alphabetical list, refresh and clear of the recently used
+/// list), then Favourites, Recently Used, Animation Presets and the effects by category or
+/// alphabetically, filtered by the query. Picking an effect or preset applies it to the selection
+/// (`effect.apply` or the preset's own command); applying an effect also records it as recently
+/// used and opens Effect Controls. Without a selected layer it only reports that in
+/// `app.ui.status`.
+pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+    let t = app.tokens;
+    let ctx = ui.ctx().clone();
+    let p = ui.painter().clone();
+    // Track the last applied effect (menus, drag and drop, the control channel) as recently used.
+    if let Some(last) = app.session.state.last_effect.clone()
+        && app.ui.effects_recent.first() != Some(&last)
+    {
+        push_recent(&mut app.ui.effects_recent, &last);
+    }
+    let sr = Rect::from_min_size(rect.min + vec2(8.0, 8.0), vec2(rect.width() - 44.0, 24.0));
+    let mut q = app.ui.effects_search.clone();
+    widgets::search_field(ui, sr, &mut q, "Search effects and presets", &t);
+    app.ui.effects_search = q.clone();
+    app.auto.add("effects.search", sr, "Search");
+    let force_scan = contents_menu(app, ui, &ctx, rect, sr, &t);
     let view = app.ui.effects_view.clone();
     let list = Rect::from_min_max(pos2(rect.min.x, sr.max.y + 6.0), rect.max);
     let lp = p.with_clip_rect(list);
diff --git a/crates/ui-egui/src/panels/essential.rs b/crates/ui-egui/src/panels/essential.rs
index a61e2a8a9..a08b96b62 100644
--- a/crates/ui-egui/src/panels/essential.rs
+++ b/crates/ui-egui/src/panels/essential.rs
@@ -76,7 +76,7 @@ fn body(app: &mut EffectcraftApp, ui: &mut egui::Ui) -> (Actions, Actions) {
     // ---- Primary + Solo.
     ui.horizontal(|ui| {
         ui.label(RichText::new(tr("Primary:")).color(t.text_dim));
-        let r = egui::ComboBox::from_id_salt("eg-primary").selected_text(&comp_name).width(150.0).show_ui(ui, |ui| {
+        let r = craft_ui::ComboBox::from_id_salt("eg-primary").selected_text(&comp_name).width(150.0).show_ui(ui, |ui| {
             for (id, _) in project.comps() {
                 let name = project.item(*id).map(|i| i.name.clone()).unwrap_or_default();
                 if ui.selectable_label(*id == cid, name).clicked() {
@@ -374,7 +374,7 @@ fn value_widget(app: &mut EffectcraftApp, ui: &mut egui::Ui, auto: &str, ty: Opt
                 _ => vec![],
             };
             let cur = v.as_enum() as usize;
-            let r = egui::ComboBox::from_id_salt(("eg-dd", auto)).selected_text(opts.get(cur).cloned().unwrap_or_default()).show_ui(ui, |ui| {
+            let r = craft_ui::ComboBox::from_id_salt(("eg-dd", auto)).selected_text(opts.get(cur).cloned().unwrap_or_default()).show_ui(ui, |ui| {
                 for (i, o) in opts.iter().enumerate() {
                     if ui.selectable_label(i == cur, o).clicked() {
                         out = Some(json!(i));
@@ -437,7 +437,7 @@ fn value_widget(app: &mut EffectcraftApp, ui: &mut egui::Ui, auto: &str, ty: Opt
             let fams = effectcraft_engine::text::fonts::families();
             let mut d = (**doc).clone();
             let mut changed = false;
-            let r1 = egui::ComboBox::from_id_salt(("eg-font", auto)).selected_text(&d.font).width(110.0).show_ui(ui, |ui| {
+            let r1 = craft_ui::ComboBox::from_id_salt(("eg-font", auto)).selected_text(&d.font).width(110.0).show_ui(ui, |ui| {
                 for (f, _) in &fams {
                     if ui.selectable_label(*f == d.font, f).clicked() {
                         d.font = f.clone();
@@ -446,7 +446,7 @@ fn value_widget(app: &mut EffectcraftApp, ui: &mut egui::Ui, auto: &str, ty: Opt
                 }
             });
             let styles: Vec<String> = fams.iter().find(|(f, _)| *f == d.font).map(|(_, st)| st.clone()).unwrap_or_default();
-            let r2 = egui::ComboBox::from_id_salt(("eg-style", auto)).selected_text(&d.style).width(70.0).show_ui(ui, |ui| {
+            let r2 = craft_ui::ComboBox::from_id_salt(("eg-style", auto)).selected_text(&d.style).width(70.0).show_ui(ui, |ui| {
                 for st in &styles {
                     if ui.selectable_label(*st == d.style, st).clicked() {
                         d.style = st.clone();
@@ -532,7 +532,7 @@ fn instance(app: &mut EffectcraftApp, ui: &mut egui::Ui, actions: &mut Actions)
                         .filter(|i| matches!(&i.kind, ItemKind::Footage(f) if f.has_video))
                         .map(|i| (i.id, i.name.clone()))
                         .collect();
-                    let r = egui::ComboBox::from_id_salt(("eg-media", layer.id.0, c.id)).selected_text(cur_name).show_ui(ui, |ui| {
+                    let r = craft_ui::ComboBox::from_id_salt(("eg-media", layer.id.0, c.id)).selected_text(cur_name).show_ui(ui, |ui| {
                         for (id, name) in &items {
                             if ui.selectable_label(*id == cur, name).clicked() {
                                 actions.push(("essential.set".into(), json!({"layer": layer.id.0, "control": c.id, "item": id.0})));
diff --git a/crates/ui-egui/src/panels/expr_editor.rs b/crates/ui-egui/src/panels/expr_editor.rs
index f342d5636..157288b94 100644
--- a/crates/ui-egui/src/panels/expr_editor.rs
+++ b/crates/ui-egui/src/panels/expr_editor.rs
@@ -331,8 +331,16 @@ fn layout(text: &str, font: FontId, base: Color32, sx: &Syntax, p: &Scripting, b
     job
 }
 
+/// The scripting preferences, text colour and row count an [`editor`] is drawn with.
+pub struct EditorOpts<'a> {
+    pub prefs: &'a Scripting,
+    pub color: Color32,
+    pub rows: usize,
+}
+
 /// The editor: returns the response; `buf` is edited in place.
-pub fn editor(ui: &mut egui::Ui, id: egui::Id, buf: &mut String, rect: Rect, p: &Scripting, color: Color32, rows: usize, t: &Tokens) -> egui::Response {
+pub fn editor(ui: &mut egui::Ui, id: egui::Id, buf: &mut String, rect: Rect, opts: EditorOpts, t: &Tokens) -> egui::Response {
+    let EditorOpts { prefs: p, color, rows } = opts;
     let size = (p.editor_font_size.clamp(8, 40) as f32) * 0.9;
     let font = Tokens::mono(size);
     // Line numbers in a gutter on the left.
diff --git a/crates/ui-egui/src/panels/forms.rs b/crates/ui-egui/src/panels/forms.rs
index 15d9100f8..e121d5d02 100644
--- a/crates/ui-egui/src/panels/forms.rs
+++ b/crates/ui-egui/src/panels/forms.rs
@@ -206,6 +206,280 @@ fn value_fields(name: &str, v: &effectcraft_engine::keyframe::Value) -> Option<V
     })
 }
 
+/// The New Composition from Selection dialog's title and fields.
+fn new_comp_from_selection_form(s: &effectcraft_engine::Session) -> (String, Vec<Field>) {
+    let names: Vec<(String, Value)> =
+        s.state.project_selection.iter().enumerate().filter_map(|(i, id)| s.project.item(*id).map(|it| (it.name.clone(), json!(i)))).collect();
+    let names: Vec<(&str, Value)> = names.iter().map(|(n, v)| (n.as_str(), v.clone())).collect();
+    let still = if s.prefs.import.still_footage == "seconds" { s.prefs.import.still_seconds } else { 10.0 };
+    (
+        "New Composition from Selection".into(),
+        vec![
+            Field::choice("single", "Create", &[("Single Composition", json!(true)), ("Multiple Compositions", json!(false))], 0),
+            Field::choice("dimensionsFrom", "Use Dimensions From", &names, 0),
+            Field::num("duration", "Still Duration (seconds)", still),
+            Field::bool("addToRenderQueue", "Add to Render Queue", false),
+            Field::bool("sequence", "Sequence Layers", false),
+            Field::bool("overlap", "Overlap", false),
+            Field::num("overlapDuration", "Duration (seconds)", 1.0),
+            Field::choice(
+                "transition",
+                "Transition",
+                &[("Off", json!("off")), ("Dissolve Front Layer", json!("dissolveFront")), ("Cross Dissolve Front and Back Layers", json!("crossDissolve"))],
+                0,
+            ),
+        ],
+    )
+}
+
+/// The Interpret Footage dialog for the selected footage (or its proxy), if there is one.
+fn interpret_footage_form(s: &effectcraft_engine::Session, proxy: bool) -> Option<(String, Vec<Field>)> {
+    let f = s.state.project_selection.first().and_then(|i| s.project.item(*i)).and_then(|it| match (&it.kind, &it.proxy) {
+        (_, Some(px)) if proxy => Some(px.footage.clone()),
+        (effectcraft_engine::project::ItemKind::Footage(f), _) if !proxy => Some(f.clone()),
+        _ => None,
+    });
+    let f = f?;
+    let hex = |c: [f32; 3]| format!("#{:02x}{:02x}{:02x}", (c[0] * 255.0).round() as u8, (c[1] * 255.0).round() as u8, (c[2] * 255.0).round() as u8);
+    let mut fields = vec![
+        // Main Options ▸ Alpha.
+        Field::choice(
+            "alpha",
+            "Alpha",
+            &[
+                ("Interpret Straight - Unmatted", json!("straight")),
+                ("Interpret Premultiplied - Matted With Color", json!("premultiplied")),
+                ("Ignore", json!("ignore")),
+                ("Guess", json!("guess")),
+            ],
+            f.alpha as usize,
+        ),
+        Field::text("matteColor", "Matte color (premultiplied)", &hex(f.premul_color)),
+        Field::bool("invertAlpha", "Invert Alpha", f.invert_alpha),
+        // Main Options ▸ Frame Rate, Fields and Pulldown, Other Options.
+        Field::num("frameRate", "Assume this frame rate", f.frame_rate.as_f64()),
+        Field::choice(
+            "fields",
+            "Separate Fields",
+            &[("Off", json!("off")), ("Upper Field First", json!("upper")), ("Lower Field First", json!("lower"))],
+            f.fields as usize,
+        ),
+        Field::num("pixelAspect", "Pixel Aspect Ratio", f.pixel_aspect),
+        Field::num("loop", "Loop (times)", f.loop_count as f64),
+        // Color.
+        Field::choice(
+            "colorProfile",
+            "Assign Profile",
+            &[
+                ("Embedded / sRGB", json!("auto")),
+                ("sRGB IEC61966-2.1", json!("srgb")),
+                ("HDTV (Rec. 709)", json!("rec709")),
+                ("Rec. 2020", json!("rec2020")),
+                ("Display P3", json!("p3")),
+                ("ACEScg", json!("acescg")),
+                ("ACES2065-1", json!("aces2065")),
+                ("Rec. 2100 PQ", json!("rec2100pq")),
+                ("Rec. 2100 HLG", json!("rec2100hlg")),
+            ],
+            f.color_profile.map_or(0, |c| 1 + effectcraft_engine::project::ColorSpace::ALL.iter().position(|x| *x == c).unwrap_or(0)),
+        ),
+        Field::bool("preserveRgb", "Preserve RGB", f.preserve_rgb),
+        Field::bool("linearLight", "Interpret As Linear Light", f.linear_light),
+    ];
+    // After Frame Rate: an image sequence's frames (missing ones show colour bars, as in
+    // After Effects), then Start Timecode.
+    let mut timing = Vec::new();
+    if f.kind == effectcraft_engine::project::FootageKind::Sequence {
+        let gaps = match effectcraft_engine::sequence::missing_report(&f.sequence) {
+            _ if f.alphabetical => "files in alphabetical order".into(),
+            Some(gaps) => format!("{gaps} shown as color bars"),
+            None => "no missing frames".into(),
+        };
+        timing.push(Field::note("sequenceInfo", &format!("Image sequence: {} files, {} frames; {gaps}.", f.sequence.len(), f.sequence_frames())));
+    }
+    if f.kind != effectcraft_engine::project::FootageKind::Still {
+        timing.push(Field::choice(
+            "overrideStart",
+            "Start Timecode",
+            &[("Use Source File Timecode", json!(false)), ("Override Start", json!(true))],
+            usize::from(f.start_timecode.is_some()),
+        ));
+        timing.push(Field::text("startTimecode", "Override Start", &f.timecode(0)));
+    }
+    let at = fields.iter().position(|x| x.key == "frameRate").map_or(fields.len(), |i| i + 1);
+    fields.splice(at..at, timing);
+    Some((if proxy { "Interpret Footage: Proxy".into() } else { "Interpret Footage".into() }, fields))
+}
+
+/// The Project Settings dialog's title and fields.
+fn project_settings_form(s: &effectcraft_engine::Session) -> (String, Vec<Field>) {
+    let st = &s.project.settings;
+    // The catalogue row is `Mercury GPU Acceleration ({})`, so the value goes through
+    // tr_args: wrapping the assembled string in tr() would look up the backend's name.
+    let gpu_label = match &s.accel {
+        Some(a) => tr_args("Mercury GPU Acceleration ({})", &[&a.name()]),
+        None => tr("Mercury GPU Acceleration (no GPU: software)").to_string(),
+    };
+    let depth = match st.bit_depth.label() {
+        l if l.starts_with("16") => 1,
+        l if l.starts_with("32") => 2,
+        _ => 0,
+    };
+    (
+        "Project Settings".into(),
+        vec![
+            Field::choice(
+                "bitDepth",
+                "Depth",
+                &[("8 bits per channel", json!(8)), ("16 bits per channel", json!(16)), ("32 bits per channel (float)", json!(32))],
+                depth,
+            ),
+            Field::choice(
+                "timeDisplay",
+                "Time display style",
+                &[
+                    ("Timecode", json!("timecode")),
+                    ("Frames", json!("frames")),
+                    ("Feet + Frames (35mm)", json!("feet35")),
+                    ("Feet + Frames (16mm)", json!("feet16")),
+                ],
+                {
+                    use effectcraft_engine::project::TimeDisplayStyle as T;
+                    match st.time_display {
+                        T::Timecode => 0,
+                        T::Frames => 1,
+                        T::Feet35 => 2,
+                        T::Feet16 => 3,
+                    }
+                },
+            ),
+            // Time Display Style ▸ Frames ▸ Frame Count (also numbers Feet + Frames).
+            Field::choice("frameStart", "Frame count", &[("Start at 0", json!(0)), ("Start at 1", json!(1))], usize::from(st.frame_start == 1)),
+            Field::choice(
+                "colorEngine",
+                "Color engine",
+                &[("Adobe-style built-in", json!("adobe")), ("OCIO (built-in ACES config)", json!("ocio"))],
+                usize::from(st.color_engine == effectcraft_engine::project::ColorEngine::Ocio),
+            ),
+            Field::choice(
+                "workingSpace",
+                "Working space",
+                &[
+                    ("None", json!("none")),
+                    ("sRGB IEC61966-2.1", json!("srgb")),
+                    ("HDTV (Rec. 709)", json!("rec709")),
+                    ("Rec. 2020", json!("rec2020")),
+                    ("Display P3", json!("p3")),
+                    ("ACEScg", json!("acescg")),
+                    ("ACES2065-1", json!("aces2065")),
+                ],
+                st.working_space.map_or(0, |c| 1 + effectcraft_engine::project::ColorSpace::WORKING.iter().position(|x| *x == c).unwrap_or(0)),
+            ),
+            // With Working Space None (After Effects' Working Gamma, 2.2 or 2.4).
+            Field::choice("workingGamma", "Working gamma", &[("2.2", json!(2.2)), ("2.4", json!(2.4))], usize::from(st.working_gamma_24())),
+            Field::bool("linearize", "Linearize working space", st.linearize),
+            Field::bool("blendLinear", "Blend colors using 1.0 gamma", st.blend_linear),
+            Field::choice(
+                "hdr",
+                "HDR on SDR displays and outputs",
+                &[("Clip", json!("clip")), ("Compand", json!("compand")), ("Tone map", json!("toneMap"))],
+                st.hdr as usize,
+            ),
+            Field::choice(
+                "outputSpace",
+                "Output color space",
+                &[
+                    ("sRGB IEC61966-2.1 (default)", json!("default")),
+                    ("HDTV (Rec. 709)", json!("rec709")),
+                    ("Rec. 2020", json!("rec2020")),
+                    ("Display P3", json!("p3")),
+                    ("Rec. 2100 PQ (HDR)", json!("rec2100pq")),
+                    ("Rec. 2100 HLG (HDR)", json!("rec2100hlg")),
+                ],
+                {
+                    use effectcraft_engine::project::ColorSpace as C;
+                    match st.output_space {
+                        Some(C::Rec709) => 1,
+                        Some(C::Rec2020) => 2,
+                        Some(C::DisplayP3) => 3,
+                        Some(C::Rec2100Pq) => 4,
+                        Some(C::Rec2100Hlg) => 5,
+                        _ => 0,
+                    }
+                },
+            ),
+            // Video Rendering and Effects ▸ Use.
+            Field::choice(
+                "renderer",
+                "Video rendering and effects",
+                &[(gpu_label.as_str(), json!("gpu")), ("Mercury Software Only", json!("software"))],
+                usize::from(!st.gpu_acceleration),
+            ),
+        ],
+    )
+}
+
+/// The Export Adobe Premiere Pro Project dialog's title and fields.
+fn export_timeline_form(s: &effectcraft_engine::Session) -> (String, Vec<Field>) {
+    let name = s.active_comp_id().and_then(|c| s.project.item(c)).map(|i| i.name.clone()).unwrap_or_else(|| "Composition".into());
+    let dir = s.path.as_deref().and_then(|p| std::path::Path::new(p).parent()).map(|d| d.to_path_buf()).unwrap_or_default();
+    let path = dir.join(format!("{name}.xml")).to_string_lossy().to_string();
+    (
+        "Export Adobe Premiere Pro Project".into(),
+        vec![
+            Field::note("note", "Writes Final Cut Pro XML (.xml), which Premiere Pro opens with File ▸ Import. Native .prproj files are not written."),
+            Field::save_path("path", "File", &path),
+            Field::choice(
+                "format",
+                "Format",
+                &[
+                    ("Final Cut Pro XML (.xml) – Premiere Pro", json!("xml")),
+                    ("FCPXML (.fcpxml)", json!("fcpxml")),
+                    ("OpenTimelineIO (.otio)", json!("otio")),
+                    ("CMX 3600 EDL (.edl, V1 only)", json!("edl")),
+                    ("AAF (.aaf)", json!("aaf")),
+                    ("OMF (.omf, audio)", json!("omf")),
+                ],
+                0,
+            ),
+            Field::choice(
+                "prerender",
+                "Pre-render (ProRes 4444)",
+                &[
+                    ("Layers Premiere can't show (text, shapes, effects…)", json!("unsupported")),
+                    ("All layers", json!("all")),
+                    ("None (leave them out)", json!("none")),
+                ],
+                0,
+            ),
+            Field::choice("precomps", "Precomps", &[("Nested sequences", json!("nest")), ("Pre-render", json!("prerender"))], 0),
+        ],
+    )
+}
+
+/// The Layer ▸ Transform value dialog for the property named by `p` (default Position).
+fn transform_form(p: &Value, layer: Option<&effectcraft_engine::project::Layer>, lt: effectcraft_engine::time::Tick) -> (String, Vec<Field>) {
+    let prop = p.get("prop").and_then(Value::as_str).unwrap_or("position");
+    let cur = layer.and_then(|l| l.transform()).and_then(|tr| tr.get(if prop == "anchorPoint" { "anchor" } else { prop })).map(|pr| pr.value_at(lt));
+    let v = cur.map(|c| c.as_vec3()).unwrap_or([0.0; 3]);
+    let three = layer.is_some_and(|l| l.is_3d());
+    let title = match prop {
+        "anchor" => "Anchor Point",
+        "position" => "Position",
+        "scale" => "Scale",
+        "orientation" => "Orientation",
+        "rotation" => "Rotation",
+        _ => "Opacity",
+    };
+    let fields = match prop {
+        "rotation" | "opacity" => vec![Field::num("value", if prop == "rotation" { "Degrees" } else { "Opacity (%)" }, v[0])],
+        "orientation" => vec![Field::num("value[0]", "X", v[0]), Field::num("value[1]", "Y", v[1]), Field::num("value[2]", "Z", v[2])],
+        _ if three => vec![Field::num("value[0]", "X", v[0]), Field::num("value[1]", "Y", v[1]), Field::num("value[2]", "Z", v[2])],
+        _ => vec![Field::num("value[0]", "X", v[0]), Field::num("value[1]", "Y", v[1])],
+    };
+    (title.into(), fields)
+}
+
 /// If `id` is a dialog command invoked without its parameters, open its form and return true.
 pub fn open_form(app: &mut EffectcraftApp, id: &str, p: &Value) -> bool {
     let s = &app.session;
@@ -281,27 +555,7 @@ pub fn open_form(app: &mut EffectcraftApp, id: &str, p: &Value) -> bool {
             let Some(fields) = value_fields(&pr.name, &pr.value_at(l.layer_time(t))) else { return false };
             (pr.name.clone(), fields)
         }
-        "layer.setTransform" if !has(p, &["value"]) => {
-            let prop = p.get("prop").and_then(Value::as_str).unwrap_or("position");
-            let cur = layer.and_then(|l| l.transform()).and_then(|tr| tr.get(if prop == "anchorPoint" { "anchor" } else { prop })).map(|pr| pr.value_at(lt));
-            let v = cur.map(|c| c.as_vec3()).unwrap_or([0.0; 3]);
-            let three = layer.is_some_and(|l| l.is_3d());
-            let title = match prop {
-                "anchor" => "Anchor Point",
-                "position" => "Position",
-                "scale" => "Scale",
-                "orientation" => "Orientation",
-                "rotation" => "Rotation",
-                _ => "Opacity",
-            };
-            let fields = match prop {
-                "rotation" | "opacity" => vec![Field::num("value", if prop == "rotation" { "Degrees" } else { "Opacity (%)" }, v[0])],
-                "orientation" => vec![Field::num("value[0]", "X", v[0]), Field::num("value[1]", "Y", v[1]), Field::num("value[2]", "Z", v[2])],
-                _ if three => vec![Field::num("value[0]", "X", v[0]), Field::num("value[1]", "Y", v[1]), Field::num("value[2]", "Z", v[2])],
-                _ => vec![Field::num("value[0]", "X", v[0]), Field::num("value[1]", "Y", v[1])],
-            };
-            (title.into(), fields)
-        }
+        "layer.setTransform" if !has(p, &["value"]) => transform_form(p, layer, lt),
         "path.freeTransform" if !has(p, &["scale", "rotation", "offset"]) => (
             "Free Transform Points".into(),
             vec![
@@ -377,32 +631,7 @@ pub fn open_form(app: &mut EffectcraftApp, id: &str, p: &Value) -> bool {
         "file.newCompFromSelection"
             if s.state.project_selection.len() > 1 && !has(p, &["single", "dimensionsFrom", "duration", "sequence", "addToRenderQueue"]) =>
         {
-            let names: Vec<(String, Value)> =
-                s.state.project_selection.iter().enumerate().filter_map(|(i, id)| s.project.item(*id).map(|it| (it.name.clone(), json!(i)))).collect();
-            let names: Vec<(&str, Value)> = names.iter().map(|(n, v)| (n.as_str(), v.clone())).collect();
-            let still = if s.prefs.import.still_footage == "seconds" { s.prefs.import.still_seconds } else { 10.0 };
-            (
-                "New Composition from Selection".into(),
-                vec![
-                    Field::choice("single", "Create", &[("Single Composition", json!(true)), ("Multiple Compositions", json!(false))], 0),
-                    Field::choice("dimensionsFrom", "Use Dimensions From", &names, 0),
-                    Field::num("duration", "Still Duration (seconds)", still),
-                    Field::bool("addToRenderQueue", "Add to Render Queue", false),
-                    Field::bool("sequence", "Sequence Layers", false),
-                    Field::bool("overlap", "Overlap", false),
-                    Field::num("overlapDuration", "Duration (seconds)", 1.0),
-                    Field::choice(
-                        "transition",
-                        "Transition",
-                        &[
-                            ("Off", json!("off")),
-                            ("Dissolve Front Layer", json!("dissolveFront")),
-                            ("Cross Dissolve Front and Back Layers", json!("crossDissolve")),
-                        ],
-                        0,
-                    ),
-                ],
-            )
+            new_comp_from_selection_form(s)
         }
         "layer.sequence" if !has(p, &["overlap"]) => (
             "Sequence Layers".into(),
@@ -425,188 +654,10 @@ pub fn open_form(app: &mut EffectcraftApp, id: &str, p: &Value) -> bool {
             if !has(p, &["frameRate", "alpha", "loop", "pixelAspect", "colorProfile", "fields", "invertAlpha", "matteColor", "linearLight", "startFrame"]) =>
         {
             let proxy = id == "file.interpretProxy";
-            let f = s.state.project_selection.first().and_then(|i| s.project.item(*i)).and_then(|it| match (&it.kind, &it.proxy) {
-                (_, Some(px)) if proxy => Some(px.footage.clone()),
-                (effectcraft_engine::project::ItemKind::Footage(f), _) if !proxy => Some(f.clone()),
-                _ => None,
-            });
-            let Some(f) = f else { return false };
-            let hex = |c: [f32; 3]| format!("#{:02x}{:02x}{:02x}", (c[0] * 255.0).round() as u8, (c[1] * 255.0).round() as u8, (c[2] * 255.0).round() as u8);
-            let mut fields = vec![
-                // Main Options ▸ Alpha.
-                Field::choice(
-                    "alpha",
-                    "Alpha",
-                    &[
-                        ("Interpret Straight - Unmatted", json!("straight")),
-                        ("Interpret Premultiplied - Matted With Color", json!("premultiplied")),
-                        ("Ignore", json!("ignore")),
-                        ("Guess", json!("guess")),
-                    ],
-                    f.alpha as usize,
-                ),
-                Field::text("matteColor", "Matte color (premultiplied)", &hex(f.premul_color)),
-                Field::bool("invertAlpha", "Invert Alpha", f.invert_alpha),
-                // Main Options ▸ Frame Rate, Fields and Pulldown, Other Options.
-                Field::num("frameRate", "Assume this frame rate", f.frame_rate.as_f64()),
-                Field::choice(
-                    "fields",
-                    "Separate Fields",
-                    &[("Off", json!("off")), ("Upper Field First", json!("upper")), ("Lower Field First", json!("lower"))],
-                    f.fields as usize,
-                ),
-                Field::num("pixelAspect", "Pixel Aspect Ratio", f.pixel_aspect),
-                Field::num("loop", "Loop (times)", f.loop_count as f64),
-                // Color.
-                Field::choice(
-                    "colorProfile",
-                    "Assign Profile",
-                    &[
-                        ("Embedded / sRGB", json!("auto")),
-                        ("sRGB IEC61966-2.1", json!("srgb")),
-                        ("HDTV (Rec. 709)", json!("rec709")),
-                        ("Rec. 2020", json!("rec2020")),
-                        ("Display P3", json!("p3")),
-                        ("ACEScg", json!("acescg")),
-                        ("ACES2065-1", json!("aces2065")),
-                        ("Rec. 2100 PQ", json!("rec2100pq")),
-                        ("Rec. 2100 HLG", json!("rec2100hlg")),
-                    ],
-                    f.color_profile.map_or(0, |c| 1 + effectcraft_engine::project::ColorSpace::ALL.iter().position(|x| *x == c).unwrap_or(0)),
-                ),
-                Field::bool("preserveRgb", "Preserve RGB", f.preserve_rgb),
-                Field::bool("linearLight", "Interpret As Linear Light", f.linear_light),
-            ];
-            // After Frame Rate: an image sequence's frames (missing ones show colour bars, as in
-            // After Effects), then Start Timecode.
-            let mut timing = Vec::new();
-            if f.kind == effectcraft_engine::project::FootageKind::Sequence {
-                let gaps = match effectcraft_engine::sequence::missing_report(&f.sequence) {
-                    _ if f.alphabetical => "files in alphabetical order".into(),
-                    Some(gaps) => format!("{gaps} shown as color bars"),
-                    None => "no missing frames".into(),
-                };
-                timing.push(Field::note("sequenceInfo", &format!("Image sequence: {} files, {} frames; {gaps}.", f.sequence.len(), f.sequence_frames())));
-            }
-            if f.kind != effectcraft_engine::project::FootageKind::Still {
-                timing.push(Field::choice(
-                    "overrideStart",
-                    "Start Timecode",
-                    &[("Use Source File Timecode", json!(false)), ("Override Start", json!(true))],
-                    usize::from(f.start_timecode.is_some()),
-                ));
-                timing.push(Field::text("startTimecode", "Override Start", &f.timecode(0)));
-            }
-            let at = fields.iter().position(|x| x.key == "frameRate").map_or(fields.len(), |i| i + 1);
-            fields.splice(at..at, timing);
-            (if proxy { "Interpret Footage: Proxy".into() } else { "Interpret Footage".into() }, fields)
-        }
-        "file.projectSettings" if p.as_object().is_none_or(|m| m.is_empty()) => {
-            let st = &s.project.settings;
-            // The catalogue row is `Mercury GPU Acceleration ({})`, so the value goes through
-            // tr_args: wrapping the assembled string in tr() would look up the backend's name.
-            let gpu_label = match &s.accel {
-                Some(a) => tr_args("Mercury GPU Acceleration ({})", &[&a.name()]),
-                None => tr("Mercury GPU Acceleration (no GPU: software)").to_string(),
-            };
-            let depth = match st.bit_depth.label() {
-                l if l.starts_with("16") => 1,
-                l if l.starts_with("32") => 2,
-                _ => 0,
-            };
-            (
-                "Project Settings".into(),
-                vec![
-                    Field::choice(
-                        "bitDepth",
-                        "Depth",
-                        &[("8 bits per channel", json!(8)), ("16 bits per channel", json!(16)), ("32 bits per channel (float)", json!(32))],
-                        depth,
-                    ),
-                    Field::choice(
-                        "timeDisplay",
-                        "Time display style",
-                        &[
-                            ("Timecode", json!("timecode")),
-                            ("Frames", json!("frames")),
-                            ("Feet + Frames (35mm)", json!("feet35")),
-                            ("Feet + Frames (16mm)", json!("feet16")),
-                        ],
-                        {
-                            use effectcraft_engine::project::TimeDisplayStyle as T;
-                            match st.time_display {
-                                T::Timecode => 0,
-                                T::Frames => 1,
-                                T::Feet35 => 2,
-                                T::Feet16 => 3,
-                            }
-                        },
-                    ),
-                    // Time Display Style ▸ Frames ▸ Frame Count (also numbers Feet + Frames).
-                    Field::choice("frameStart", "Frame count", &[("Start at 0", json!(0)), ("Start at 1", json!(1))], usize::from(st.frame_start == 1)),
-                    Field::choice(
-                        "colorEngine",
-                        "Color engine",
-                        &[("Adobe-style built-in", json!("adobe")), ("OCIO (built-in ACES config)", json!("ocio"))],
-                        usize::from(st.color_engine == effectcraft_engine::project::ColorEngine::Ocio),
-                    ),
-                    Field::choice(
-                        "workingSpace",
-                        "Working space",
-                        &[
-                            ("None", json!("none")),
-                            ("sRGB IEC61966-2.1", json!("srgb")),
-                            ("HDTV (Rec. 709)", json!("rec709")),
-                            ("Rec. 2020", json!("rec2020")),
-                            ("Display P3", json!("p3")),
-                            ("ACEScg", json!("acescg")),
-                            ("ACES2065-1", json!("aces2065")),
-                        ],
-                        st.working_space.map_or(0, |c| 1 + effectcraft_engine::project::ColorSpace::WORKING.iter().position(|x| *x == c).unwrap_or(0)),
-                    ),
-                    // With Working Space None (After Effects' Working Gamma, 2.2 or 2.4).
-                    Field::choice("workingGamma", "Working gamma", &[("2.2", json!(2.2)), ("2.4", json!(2.4))], usize::from(st.working_gamma_24())),
-                    Field::bool("linearize", "Linearize working space", st.linearize),
-                    Field::bool("blendLinear", "Blend colors using 1.0 gamma", st.blend_linear),
-                    Field::choice(
-                        "hdr",
-                        "HDR on SDR displays and outputs",
-                        &[("Clip", json!("clip")), ("Compand", json!("compand")), ("Tone map", json!("toneMap"))],
-                        st.hdr as usize,
-                    ),
-                    Field::choice(
-                        "outputSpace",
-                        "Output color space",
-                        &[
-                            ("sRGB IEC61966-2.1 (default)", json!("default")),
-                            ("HDTV (Rec. 709)", json!("rec709")),
-                            ("Rec. 2020", json!("rec2020")),
-                            ("Display P3", json!("p3")),
-                            ("Rec. 2100 PQ (HDR)", json!("rec2100pq")),
-                            ("Rec. 2100 HLG (HDR)", json!("rec2100hlg")),
-                        ],
-                        {
-                            use effectcraft_engine::project::ColorSpace as C;
-                            match st.output_space {
-                                Some(C::Rec709) => 1,
-                                Some(C::Rec2020) => 2,
-                                Some(C::DisplayP3) => 3,
-                                Some(C::Rec2100Pq) => 4,
-                                Some(C::Rec2100Hlg) => 5,
-                                _ => 0,
-                            }
-                        },
-                    ),
-                    // Video Rendering and Effects ▸ Use.
-                    Field::choice(
-                        "renderer",
-                        "Video rendering and effects",
-                        &[(gpu_label.as_str(), json!("gpu")), ("Mercury Software Only", json!("software"))],
-                        usize::from(!st.gpu_acceleration),
-                    ),
-                ],
-            )
+            let Some(form) = interpret_footage_form(s, proxy) else { return false };
+            form
         }
+        "file.projectSettings" if p.as_object().is_none_or(|m| m.is_empty()) => project_settings_form(s),
         "layer.autoTrace" if !has(p, &["channel", "timeSpan", "threshold"]) => (
             "Auto-trace".into(),
             vec![
@@ -662,42 +713,7 @@ pub fn open_form(app: &mut EffectcraftApp, id: &str, p: &Value) -> bool {
             )
         }
         // File ▸ Export ▸ Adobe Premiere Pro Project…: Final Cut Pro XML (or FCPXML / OTIO / EDL).
-        "file.exportTimeline" if !has(p, &["path"]) => {
-            let name = s.active_comp_id().and_then(|c| s.project.item(c)).map(|i| i.name.clone()).unwrap_or_else(|| "Composition".into());
-            let dir = s.path.as_deref().and_then(|p| std::path::Path::new(p).parent()).map(|d| d.to_path_buf()).unwrap_or_default();
-            let path = dir.join(format!("{name}.xml")).to_string_lossy().to_string();
-            (
-                "Export Adobe Premiere Pro Project".into(),
-                vec![
-                    Field::note("note", "Writes Final Cut Pro XML (.xml), which Premiere Pro opens with File ▸ Import. Native .prproj files are not written."),
-                    Field::save_path("path", "File", &path),
-                    Field::choice(
-                        "format",
-                        "Format",
-                        &[
-                            ("Final Cut Pro XML (.xml) – Premiere Pro", json!("xml")),
-                            ("FCPXML (.fcpxml)", json!("fcpxml")),
-                            ("OpenTimelineIO (.otio)", json!("otio")),
-                            ("CMX 3600 EDL (.edl, V1 only)", json!("edl")),
-                            ("AAF (.aaf)", json!("aaf")),
-                            ("OMF (.omf, audio)", json!("omf")),
-                        ],
-                        0,
-                    ),
-                    Field::choice(
-                        "prerender",
-                        "Pre-render (ProRes 4444)",
-                        &[
-                            ("Layers Premiere can't show (text, shapes, effects…)", json!("unsupported")),
-                            ("All layers", json!("all")),
-                            ("None (leave them out)", json!("none")),
-                        ],
-                        0,
-                    ),
-                    Field::choice("precomps", "Precomps", &[("Nested sequences", json!("nest")), ("Pre-render", json!("prerender"))], 0),
-                ],
-            )
-        }
+        "file.exportTimeline" if !has(p, &["path"]) => export_timeline_form(s),
         "file.importPlaceholder" | "file.replaceWithPlaceholder" if p.as_object().is_none_or(|m| m.is_empty()) => (
             "New Placeholder".into(),
             vec![
@@ -830,7 +846,7 @@ fn form_grid(ui: &mut egui::Ui, f: &mut Form, regs: &mut Vec<(String, egui::Rect
                     let cur = options.get(*sel).map(|o| o.0.clone()).unwrap_or_default();
                     // The column keeps its width: a long choice (a GPU adapter's name) ends in an
                     // ellipsis instead of widening the form past the dialog (#978).
-                    egui::ComboBox::from_id_salt(("form", fl.key.as_str()))
+                    craft_ui::ComboBox::from_id_salt(("form", fl.key.as_str()))
                         .selected_text(tr(&cur))
                         .width(240.0)
                         .truncate()
diff --git a/crates/ui-egui/src/panels/fx_editors.rs b/crates/ui-egui/src/panels/fx_editors.rs
index b7b09dad4..4ed96797a 100644
--- a/crates/ui-egui/src/panels/fx_editors.rs
+++ b/crates/ui-egui/src/panels/fx_editors.rs
@@ -66,19 +66,9 @@ fn register_points(app: &mut EffectcraftApp, prefix: &str, gr: Rect, pts: &[[f32
 }
 
 /// Small coloured tabs (`names[i]`, swatch `cols[i]`); returns the clicked one.
-fn tabs(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    p: &egui::Painter,
-    x0: f32,
-    cy: f32,
-    cur: usize,
-    names: &[&str],
-    cols: &[Color32],
-    id: &str,
-) -> Option<usize> {
+fn tabs(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, at: Pos2, cur: usize, (names, cols): (&[&str], &[Color32]), id: &str) -> Option<usize> {
     let t = app.tokens;
-    let mut x = x0;
+    let (mut x, cy) = (at.x, at.y);
     let mut out = None;
     for (i, name) in names.iter().enumerate() {
         let w = if cols.is_empty() { 16.0 + name.chars().count() as f32 * 6.2 } else { 20.0 };
@@ -188,7 +178,7 @@ fn rgb_curves(
     let cy = r.min.y + 15.0;
     let cols = [Color32::from_gray(0xe8), Color32::from_rgb(0xf0, 0x50, 0x50), Color32::from_rgb(0x50, 0xd0, 0x60), Color32::from_rgb(0x50, 0x80, 0xff)];
     let names: Vec<&str> = RGB_CURVES.iter().map(|c| c.1).collect();
-    if let Some(n) = tabs(app, ui, p, x0, cy, ch, &names, &cols, &format!("{prefix}.channel")) {
+    if let Some(n) = tabs(app, ui, p, pos2(x0, cy), ch, (&names, &cols), &format!("{prefix}.channel")) {
         app.ui.fx_curve_channel.insert(g.uid, n);
     }
     let id = RGB_CURVES[ch].0;
@@ -299,7 +289,7 @@ fn huesat_curves(
     let x0 = r.min.x + 38.0;
     let cy = r.min.y + 15.0;
     let names: Vec<&str> = HUESAT.iter().map(|c| c.1).collect();
-    if let Some(n) = tabs(app, ui, p, x0, cy, k, &names, &[], &format!("{prefix}.curve")) {
+    if let Some(n) = tabs(app, ui, p, pos2(x0, cy), k, (&names, &[]), &format!("{prefix}.curve")) {
         app.ui.fx_curve_channel.insert(g.uid, n);
     }
     let (id, name, axis, periodic) = HUESAT[k];
@@ -724,7 +714,7 @@ fn glow_map(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, laye
     }
     let ch = app.ui.fx_curve_channel.get(&euid).copied().unwrap_or(0).min(2);
     let cols = [Color32::from_rgb(0xf0, 0x50, 0x50), Color32::from_rgb(0x50, 0xd0, 0x60), Color32::from_rgb(0x50, 0x80, 0xff)];
-    if let Some(n) = tabs(app, ui, p, x0, r.min.y + 15.0, ch, &["Red", "Green", "Blue"], &cols, &format!("{prefix}.channel")) {
+    if let Some(n) = tabs(app, ui, p, pos2(x0, r.min.y + 15.0), ch, (&["Red", "Green", "Blue"], &cols), &format!("{prefix}.channel")) {
         app.ui.fx_curve_channel.insert(euid, n);
     }
     if reset_link(app, ui, p, Rect::from_min_size(pos2(x0 + size - 44.0, r.min.y + 6.0), vec2(44.0, 18.0)), &format!("{prefix}.reset")) {
diff --git a/crates/ui-egui/src/panels/fx_widgets.rs b/crates/ui-egui/src/panels/fx_widgets.rs
index e917827cc..b23000d27 100644
--- a/crates/ui-egui/src/panels/fx_widgets.rs
+++ b/crates/ui-egui/src/panels/fx_widgets.rs
@@ -59,7 +59,8 @@ pub fn angle_field(ui: &mut egui::Ui, at: Pos2, id: egui::Id, v: f64, decimals:
     let (rev, deg) = split_angle(v);
     let (rr, new_rev, _) = widgets::hot_int_at(ui, at, id.with("rev"), rev, 0.1, "x", t);
     let sign = ui.painter().text(pos2(rr.max.x - 2.0, rr.center().y), Align2::LEFT_CENTER, if deg < 0.0 { "-" } else { "+" }, Tokens::ui(12.0), t.hot_text);
-    let (dr, new_deg, _) = widgets::hot_number_at(ui, pos2(sign.max.x - 2.0, at.y), id, deg.abs(), 0.5, (-1e9, 1e9), decimals, "°", t);
+    let (dr, new_deg, _) =
+        widgets::hot_number_at(ui, pos2(sign.max.x - 2.0, at.y), id, deg.abs(), &widgets::HotSpec { speed: 0.5, range: (-1e9, 1e9), decimals, suffix: "°" }, t);
     let dragging = new_deg.is_some() && ui.ctx().is_being_dragged(id);
     let out = match (new_rev, new_deg) {
         (Some(r), _) => Some(r as f64 * 360.0 + deg),
diff --git a/crates/ui-egui/src/panels/graph.rs b/crates/ui-egui/src/panels/graph.rs
index 66ba31470..24df22616 100644
--- a/crates/ui-egui/src/panels/graph.rs
+++ b/crates/ui-egui/src/panels/graph.rs
@@ -240,17 +240,16 @@ impl ButtonBar {
 /// at `y`: draws it, registers it for automation and advances the bar. Once a button does not fit
 /// (or a previous one overflowed), the button goes to the "»" menu instead and only the id the
 /// menu picked reports a click. Returns whether this button was chosen.
-fn text_button(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    p: &egui::Painter,
-    bar: &mut ButtonBar,
-    y: f32,
-    label: &str,
+/// One bar button for [`text_button`]: label, lit state, automation id and tooltip.
+struct BarBtn<'a> {
+    label: &'a str,
     on: bool,
-    id: &str,
-    tip: &str,
-) -> bool {
+    id: &'a str,
+    tip: &'a str,
+}
+
+fn text_button(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, bar: &mut ButtonBar, y: f32, btn: BarBtn) -> bool {
+    let BarBtn { label, on, id, tip } = btn;
     let t = app.tokens;
     let w = p.layout_no_wrap(label.to_string(), Tokens::ui(11.0), t.text).size().x + 14.0;
     // Once one button overflows, the rest follow it into the menu (they keep their order).
@@ -277,35 +276,44 @@ fn text_button(
     resp.clicked()
 }
 
-/// Draw the Graph Editor into `area` (the right side of the Timeline) and queue edits.
-pub(crate) fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, comp: &Comp, ectx: &EvalCtx, tm: TMap, area: Rect, actions: &mut Actions) {
-    let t = app.tokens;
-    let ctx = ui.ctx().clone();
-    let footer_h = 28.0;
-    let plot = Rect::from_min_max(area.min + vec2(0.0, 6.0), pos2(area.max.x, area.max.y - footer_h));
-    let bar = Rect::from_min_max(pos2(area.min.x, area.max.y - footer_h), area.max);
-    // Background first so keys and handles (added later) sit on top for hit-testing.
-    let bg = ui.interact(plot, egui::Id::unique("graph-bg"), Sense::click_and_drag());
-    p.rect_filled(area, 0.0, Color32::from_rgb(0x1d, 0x1d, 0x1d));
-    app.auto.add("timeline.graph", plot, &app.ui.timeline.graph_mode.clone());
-    let speed = speed_graph(app, comp);
-    let cs = curves(app, comp, ectx, tm, plot, speed);
-    // Just opened, or the graph type changed (value and speed have different units): frame the
-    // graphs (Fit Selection to View, else Fit All Graphs to View).
-    let was_speed_id = egui::Id::unique("graph-was-speed");
-    let type_changed = ctx.data(|d| d.get_temp::<bool>(was_speed_id)).is_some_and(|was| was != speed);
-    ctx.data_mut(|d| d.insert_temp(was_speed_id, speed));
-    if ctx.data_mut(|d| d.remove_temp::<bool>(fit_pending_id())).unwrap_or(false) || type_changed {
-        if cs.iter().any(|c| c.keys.iter().any(|k| k.sel)) {
-            fit_selection(app, &cs, tm, plot, speed);
-        } else {
-            fit_all(app);
+/// What the Graph Editor draws: the composition, its evaluation context and the time mapping.
+#[derive(Clone, Copy)]
+pub(crate) struct GraphView<'a> {
+    pub comp: &'a Comp,
+    pub ectx: &'a EvalCtx<'a>,
+    pub tm: TMap,
+}
+
+/// Show Reference Graph: the other graph type, faint, scaled to the plot.
+fn reference_graph(app: &EffectcraftApp, view: GraphView, plot: Rect, speed: bool, pc: &egui::Painter) {
+    let GraphView { comp, ectx, tm } = view;
+    let other = curves(app, comp, ectx, tm, plot, !speed);
+    let (mut rlo, mut rhi) = (f64::INFINITY, f64::NEG_INFINITY);
+    for c in &other {
+        for (_, v) in &c.pts {
+            rlo = rlo.min(*v);
+            rhi = rhi.max(*v);
         }
     }
+    if rlo.is_finite() {
+        let span = (rhi - rlo).max(1e-9);
+        let lines: Vec<(Color32, Vec<Pos2>)> = other
+            .iter()
+            .map(|c| {
+                (
+                    c.color,
+                    c.pts.iter().map(|(ct, v)| pos2(tm.x(*ct), plot.max.y - ((v - rlo) / span) as f32 * plot.height() * 0.9 - plot.height() * 0.05)).collect(),
+                )
+            })
+            .collect();
+        super::graph_tools::reference_graph(pc, plot, &lines);
+    }
+}
 
-    // Vertical range: auto-zoom to the curves + handles, or the stored manual range.
+/// The value range that fits every curve point and key handle (with a margin).
+fn auto_range(cs: &[Curve], speed: bool) -> (f64, f64) {
     let (mut lo, mut hi) = (f64::INFINITY, f64::NEG_INFINITY);
-    for c in &cs {
+    for c in cs {
         for (_, v) in &c.pts {
             lo = lo.min(*v);
             hi = hi.max(*v);
@@ -327,7 +335,78 @@ pub(crate) fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painte
         hi = lo + 1.0;
     }
     let pad = (hi - lo) * 0.08;
-    let auto = (lo - pad, hi + pad);
+    (lo - pad, hi + pad)
+}
+
+/// Background: a click deselects keys, a drag box-selects the keys inside it.
+fn box_select(ui: &egui::Ui, pc: &egui::Painter, bg: &egui::Response, key_screens: &[(serde_json::Value, Pos2)], accent: Color32, actions: &mut Actions) {
+    let ctx = ui.ctx().clone();
+    if bg.clicked() {
+        actions.push(("keys.select".into(), json!({"keys": []})));
+    }
+    if bg.dragged()
+        && let (Some(o), Some(cur)) = (ctx.input(|i| i.pointer.press_origin()), bg.interact_pointer_pos())
+    {
+        let br = Rect::from_two_pos(o, cur);
+        pc.rect_filled(br, 0.0, accent.gamma_multiply(0.12));
+        pc.rect_stroke(br, 0.0, Stroke::new(1.0, accent), StrokeKind::Middle);
+        ctx.data_mut(|d| d.insert_temp(egui::Id::unique("graph-box"), br));
+    }
+    if bg.drag_stopped()
+        && let Some(br) = ctx.data(|d| d.get_temp::<Rect>(egui::Id::unique("graph-box")))
+    {
+        ctx.data_mut(|d| d.remove::<Rect>(egui::Id::unique("graph-box")));
+        let keys: Vec<serde_json::Value> = key_screens.iter().filter(|(_, sp)| br.contains(*sp)).map(|(k, _)| k.clone()).collect();
+        actions.push(("keys.select".into(), json!({"keys": keys, "add": ui.input(|i| i.modifiers.shift)})));
+    }
+}
+
+/// Wheel over the graph with Ctrl zooms the value axis `(lo, hi)` (turns auto-zoom off).
+fn wheel_zoom(app: &mut EffectcraftApp, ui: &egui::Ui, plot: Rect, (lo, hi): (f64, f64)) {
+    if ui.rect_contains_pointer(plot) {
+        let (dy, zoom) = ui.input(|i| (i.smooth_scroll_delta.y, i.modifiers.ctrl || i.modifiers.command));
+        if zoom && dy.abs() > 0.0 {
+            let k = (-dy as f64 / 200.0).exp();
+            let mid = (lo + hi) / 2.0;
+            app.ui.timeline.graph_auto_zoom = false;
+            app.ui.timeline.graph_range = Some((mid - (mid - lo) * k, mid + (hi - mid) * k));
+        }
+    }
+}
+
+/// Just opened, or the graph type changed (value and speed have different units): frame the
+/// graphs (Fit Selection to View, else Fit All Graphs to View).
+fn fit_on_open(app: &mut EffectcraftApp, ctx: &egui::Context, cs: &[Curve], tm: TMap, plot: Rect, speed: bool) {
+    let was_speed_id = egui::Id::unique("graph-was-speed");
+    let type_changed = ctx.data(|d| d.get_temp::<bool>(was_speed_id)).is_some_and(|was| was != speed);
+    ctx.data_mut(|d| d.insert_temp(was_speed_id, speed));
+    if ctx.data_mut(|d| d.remove_temp::<bool>(fit_pending_id())).unwrap_or(false) || type_changed {
+        if cs.iter().any(|c| c.keys.iter().any(|k| k.sel)) {
+            fit_selection(app, cs, tm, plot, speed);
+        } else {
+            fit_all(app);
+        }
+    }
+}
+
+/// Draw the Graph Editor into `area` (the right side of the Timeline) and queue edits.
+pub(crate) fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, view: GraphView, area: Rect, actions: &mut Actions) {
+    let GraphView { comp, ectx, tm } = view;
+    let t = app.tokens;
+    let ctx = ui.ctx().clone();
+    let footer_h = 28.0;
+    let plot = Rect::from_min_max(area.min + vec2(0.0, 6.0), pos2(area.max.x, area.max.y - footer_h));
+    let bar = Rect::from_min_max(pos2(area.min.x, area.max.y - footer_h), area.max);
+    // Background first so keys and handles (added later) sit on top for hit-testing.
+    let bg = ui.interact(plot, egui::Id::unique("graph-bg"), Sense::click_and_drag());
+    p.rect_filled(area, 0.0, Color32::from_rgb(0x1d, 0x1d, 0x1d));
+    app.auto.add("timeline.graph", plot, &app.ui.timeline.graph_mode.clone());
+    let speed = speed_graph(app, comp);
+    let cs = curves(app, comp, ectx, tm, plot, speed);
+    fit_on_open(app, &ctx, &cs, tm, plot, speed);
+
+    // Vertical range: auto-zoom to the curves + handles, or the stored manual range.
+    let auto = auto_range(&cs, speed);
     // While a key or handle is being dragged the scale stays put (no feedback loop).
     let drag_id = egui::Id::unique("graph-dragging");
     let dragging = ctx.data(|d| d.get_temp::<bool>(drag_id)).unwrap_or(false) && ctx.input(|i| i.pointer.any_down());
@@ -358,32 +437,8 @@ pub(crate) fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painte
         );
     }
 
-    // Show Reference Graph: the other graph type, faint, scaled to the plot.
     if app.ui.timeline.graph_reference && !cs.is_empty() {
-        let other = curves(app, comp, ectx, tm, plot, !speed);
-        let (mut rlo, mut rhi) = (f64::INFINITY, f64::NEG_INFINITY);
-        for c in &other {
-            for (_, v) in &c.pts {
-                rlo = rlo.min(*v);
-                rhi = rhi.max(*v);
-            }
-        }
-        if rlo.is_finite() {
-            let span = (rhi - rlo).max(1e-9);
-            let lines: Vec<(Color32, Vec<Pos2>)> = other
-                .iter()
-                .map(|c| {
-                    (
-                        c.color,
-                        c.pts
-                            .iter()
-                            .map(|(ct, v)| pos2(tm.x(*ct), plot.max.y - ((v - rlo) / span) as f32 * plot.height() * 0.9 - plot.height() * 0.05))
-                            .collect(),
-                    )
-                })
-                .collect();
-            super::graph_tools::reference_graph(&pc, plot, &lines);
-        }
+        reference_graph(app, view, plot, speed, &pc);
     }
     // Curves.
     for c in &cs {
@@ -523,37 +578,19 @@ pub(crate) fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painte
 
     super::graph_tools::transform_box(app, ui, &pc, &sel_keys, tm, &ymap, &vmap, speed, true, actions);
 
-    // Background: click deselects keys, drag box-selects.
-    if bg.clicked() {
-        actions.push(("keys.select".into(), json!({"keys": []})));
-    }
-    if bg.dragged()
-        && let (Some(o), Some(cur)) = (ctx.input(|i| i.pointer.press_origin()), bg.interact_pointer_pos())
-    {
-        let br = Rect::from_two_pos(o, cur);
-        pc.rect_filled(br, 0.0, t.accent.gamma_multiply(0.12));
-        pc.rect_stroke(br, 0.0, Stroke::new(1.0, t.accent), StrokeKind::Middle);
-        ctx.data_mut(|d| d.insert_temp(egui::Id::unique("graph-box"), br));
-    }
-    if bg.drag_stopped()
-        && let Some(br) = ctx.data(|d| d.get_temp::<Rect>(egui::Id::unique("graph-box")))
-    {
-        ctx.data_mut(|d| d.remove::<Rect>(egui::Id::unique("graph-box")));
-        let keys: Vec<serde_json::Value> = key_screens.iter().filter(|(_, sp)| br.contains(*sp)).map(|(k, _)| k.clone()).collect();
-        actions.push(("keys.select".into(), json!({"keys": keys, "add": ui.input(|i| i.modifiers.shift)})));
-    }
-    // Wheel over the graph with Alt/Ctrl zooms the value axis (turns auto-zoom off).
-    if ui.rect_contains_pointer(plot) {
-        let (dy, zoom) = ui.input(|i| (i.smooth_scroll_delta.y, i.modifiers.ctrl || i.modifiers.command));
-        if zoom && dy.abs() > 0.0 {
-            let k = (-dy as f64 / 200.0).exp();
-            let mid = (lo + hi) / 2.0;
-            app.ui.timeline.graph_auto_zoom = false;
-            app.ui.timeline.graph_range = Some((mid - (mid - lo) * k, mid + (hi - mid) * k));
-        }
+    box_select(ui, &pc, &bg, &key_screens, t.accent, actions);
+    wheel_zoom(app, ui, plot, (lo, hi));
+    if button_bar(app, ui, p, comp, bar, speed, actions) {
+        fit_selection(app, &cs, tm, plot, speed);
     }
+}
 
-    // Button bar.
+/// The footer button bar: graph type, display toggles, fit, snap and keyframe interpolation.
+/// Returns whether Fit Selection was pressed.
+fn button_bar(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, comp: &Comp, bar: Rect, speed: bool, actions: &mut Actions) -> bool {
+    let t = app.tokens;
+    let ctx = ui.ctx().clone();
+    let mut fit_sel = false;
     p.rect_filled(bar, 0.0, t.panel_bg);
     p.line_segment([bar.left_top(), bar.right_top()], Stroke::new(1.0, t.separator));
     let y = bar.center().y;
@@ -566,48 +603,71 @@ pub(crate) fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painte
         p,
         &mut buttons,
         y,
-        "Auto",
-        auto_type,
-        "autoSelectGraphType",
-        "Auto-Select Graph Type (speed graph for spatial properties, else value graph)",
+        BarBtn {
+            label: "Auto",
+            on: auto_type,
+            id: "autoSelectGraphType",
+            tip: "Auto-Select Graph Type (speed graph for spatial properties, else value graph)",
+        },
     ) {
         app.ui.timeline.graph_mode = if auto_type { if speed { "speed" } else { "value" } } else { "auto" }.into();
     }
     // Choosing a graph type turns Auto-Select off, as in After Effects.
-    if text_button(app, ui, p, &mut buttons, y, "Value", !speed, "valueGraph", "Edit Value Graph") {
+    if text_button(app, ui, p, &mut buttons, y, BarBtn { label: "Value", on: !speed, id: "valueGraph", tip: "Edit Value Graph" }) {
         app.ui.timeline.graph_mode = "value".into();
     }
-    if text_button(app, ui, p, &mut buttons, y, "Speed", speed, "speedGraph", "Edit Speed Graph") {
+    if text_button(app, ui, p, &mut buttons, y, BarBtn { label: "Speed", on: speed, id: "speedGraph", tip: "Edit Speed Graph" }) {
         app.ui.timeline.graph_mode = "speed".into();
     }
     buttons.x += 6.0;
-    if text_button(app, ui, p, &mut buttons, y, "Selected", show_sel, "showSelected", "Show Selected Properties (else all animated properties)") {
+    if text_button(
+        app,
+        ui,
+        p,
+        &mut buttons,
+        y,
+        BarBtn { label: "Selected", on: show_sel, id: "showSelected", tip: "Show Selected Properties (else all animated properties)" },
+    ) {
         app.ui.timeline.graph_show_selected = !show_sel;
     }
-    if text_button(app, ui, p, &mut buttons, y, "Auto-zoom", auto_on, "autoZoom", "Auto-zoom graph height") {
+    if text_button(app, ui, p, &mut buttons, y, BarBtn { label: "Auto-zoom", on: auto_on, id: "autoZoom", tip: "Auto-zoom graph height" }) {
         app.ui.timeline.graph_auto_zoom = !auto_on;
     }
-    if text_button(app, ui, p, &mut buttons, y, "Fit", false, "fit", "Fit all graphs to view") {
+    if text_button(app, ui, p, &mut buttons, y, BarBtn { label: "Fit", on: false, id: "fit", tip: "Fit all graphs to view" }) {
         fit_all(app);
     }
-    if text_button(app, ui, p, &mut buttons, y, "Fit Selection", false, "fitSelection", "Fit selection to view") {
-        fit_selection(app, &cs, tm, plot, speed);
+    if text_button(app, ui, p, &mut buttons, y, BarBtn { label: "Fit Selection", on: false, id: "fitSelection", tip: "Fit selection to view" }) {
+        fit_sel = true;
     }
     buttons.x += 6.0;
     let (snap, reference, tbox) = (app.ui.timeline.graph_snap, app.ui.timeline.graph_reference, app.ui.timeline.graph_transform_box);
-    if text_button(app, ui, p, &mut buttons, y, "Snap", snap, "snap", "Snap (key drags snap to the current time and other keys)") {
+    if text_button(app, ui, p, &mut buttons, y, BarBtn { label: "Snap", on: snap, id: "snap", tip: "Snap (key drags snap to the current time and other keys)" })
+    {
         app.ui.timeline.graph_snap = !snap;
     }
-    if text_button(app, ui, p, &mut buttons, y, "Reference", reference, "reference", "Show Reference Graph") {
+    if text_button(app, ui, p, &mut buttons, y, BarBtn { label: "Reference", on: reference, id: "reference", tip: "Show Reference Graph" }) {
         app.ui.timeline.graph_reference = !reference;
     }
-    if text_button(app, ui, p, &mut buttons, y, "Transform Box", tbox, "transformBox", "Show Transform Box when multiple keys are selected") {
+    if text_button(
+        app,
+        ui,
+        p,
+        &mut buttons,
+        y,
+        BarBtn { label: "Transform Box", on: tbox, id: "transformBox", tip: "Show Transform Box when multiple keys are selected" },
+    ) {
         app.ui.timeline.graph_transform_box = !tbox;
     }
     buttons.x += 6.0;
     let pos_sel = app.session.state.selected_props.iter().find_map(|(l, u)| super::timeline::is_position(comp.layer(*l)?, *u).then_some(l.0));
-    if text_button(app, ui, p, &mut buttons, y, "Separate Dimensions", false, "separateDimensions", "Separate Dimensions (Position)")
-        && let Some(l) = pos_sel.or(app.session.state.selected_layers.first().map(|l| l.0))
+    if text_button(
+        app,
+        ui,
+        p,
+        &mut buttons,
+        y,
+        BarBtn { label: "Separate Dimensions", on: false, id: "separateDimensions", tip: "Separate Dimensions (Position)" },
+    ) && let Some(l) = pos_sel.or(app.session.state.selected_layers.first().map(|l| l.0))
     {
         actions.push(("prop.separateDimensions".into(), json!({"layer": l})));
     }
@@ -621,11 +681,12 @@ pub(crate) fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painte
         ("Ease Out", "keys.easyEaseOut", json!({}), "Easy Ease Out (Ctrl+Shift+F9)"),
     ] {
         let id = cmd.trim_start_matches("keys.").to_string() + label.split_whitespace().next().unwrap_or("");
-        if text_button(app, ui, p, &mut buttons, y, label, false, &id, tip) {
+        if text_button(app, ui, p, &mut buttons, y, BarBtn { label, on: false, id: &id, tip }) {
             actions.push((cmd.into(), params));
         }
     }
     buttons.more(app, ui, p, bar);
+    fit_sel
 }
 
 /// Fit All Graphs to View: the whole comp in time, auto-zoomed values.
diff --git a/crates/ui-egui/src/panels/key_dialogs.rs b/crates/ui-egui/src/panels/key_dialogs.rs
index 73f76aaaa..22e31c468 100644
--- a/crates/ui-egui/src/panels/key_dialogs.rs
+++ b/crates/ui-egui/src/panels/key_dialogs.rs
@@ -125,8 +125,16 @@ fn buttons(ui: &mut egui::Ui, app: &mut EffectcraftApp, t: &Tokens, prefix: &str
     (ok, cancel)
 }
 
-fn drag(ui: &mut egui::Ui, app: &mut EffectcraftApp, id: &str, v: &mut f64, speed: f64, range: std::ops::RangeInclusive<f64>, suffix: &str, enabled: bool) {
-    let r = ui.add_enabled(enabled, crate::widgets::drag_value(egui::DragValue::new(v).speed(speed).range(range).max_decimals(2).suffix(suffix)));
+/// Drag speed, clamp range and suffix of a [`drag`] field.
+struct DragSpec<'a> {
+    speed: f64,
+    range: std::ops::RangeInclusive<f64>,
+    suffix: &'a str,
+}
+
+fn drag(ui: &mut egui::Ui, app: &mut EffectcraftApp, id: &str, v: &mut f64, spec: DragSpec, enabled: bool) {
+    let r =
+        ui.add_enabled(enabled, crate::widgets::drag_value(egui::DragValue::new(v).speed(spec.speed).range(spec.range).max_decimals(2).suffix(spec.suffix)));
     app.auto.add(id, r.rect, id);
 }
 
@@ -147,13 +155,13 @@ pub fn velocity(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
                     ui.horizontal(|ui| {
                         ui.label(tr("Speed:"));
                         let v = if out { &mut d.out_speed[dim] } else { &mut d.in_speed[dim] };
-                        drag(ui, app, &format!("dialog.velocity.{side}Speed.{dim}"), v, 1.0, -1e7..=1e7, "", enabled);
+                        drag(ui, app, &format!("dialog.velocity.{side}Speed.{dim}"), v, DragSpec { speed: 1.0, range: -1e7..=1e7, suffix: "" }, enabled);
                         ui.label(egui::RichText::new(&d.units).color(t.text_dim));
                     });
                     ui.horizontal(|ui| {
                         ui.label(tr("Influence:"));
                         let v = if out { &mut d.out_inf[dim] } else { &mut d.in_inf[dim] };
-                        drag(ui, app, &format!("dialog.velocity.{side}Influence.{dim}"), v, 0.2, 0.1..=100.0, " %", enabled);
+                        drag(ui, app, &format!("dialog.velocity.{side}Influence.{dim}"), v, DragSpec { speed: 0.2, range: 0.1..=100.0, suffix: " %" }, enabled);
                     });
                     ui.end_row();
                 }
@@ -191,7 +199,7 @@ pub fn velocity(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
 fn combo(ui: &mut egui::Ui, app: &mut EffectcraftApp, id: &str, sel: &mut usize, opts: &[&str], enabled: bool) {
     ui.add_enabled_ui(enabled, |ui| {
         // The options are the English source strings; the automation id and label stay English.
-        let r = egui::ComboBox::from_id_salt(id).width(200.0).selected_text(tr(opts[*sel])).show_ui(ui, |ui| {
+        let r = craft_ui::ComboBox::from_id_salt(id).width(200.0).selected_text(tr(opts[*sel])).show_ui(ui, |ui| {
             for (i, o) in opts.iter().enumerate() {
                 ui.selectable_value(sel, i, tr(o));
             }
@@ -254,14 +262,14 @@ pub fn time_stretch(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
             ui.end_row();
             ui.label(tr("Stretch Factor:"));
             let before = d.percent;
-            drag(ui, app, "dialog.timeStretch.percent", &mut d.percent, 0.5, -10000.0..=10000.0, " %", true);
+            drag(ui, app, "dialog.timeStretch.percent", &mut d.percent, DragSpec { speed: 0.5, range: -10000.0..=10000.0, suffix: " %" }, true);
             if (before - d.percent).abs() > 1e-9 && d.orig_percent.abs() > 1e-9 {
                 d.duration = d.orig_duration * d.percent.abs() / d.orig_percent.abs();
             }
             ui.end_row();
             ui.label(tr("New Duration:"));
             let before = d.duration;
-            drag(ui, app, "dialog.timeStretch.duration", &mut d.duration, 0.05, 0.01..=100000.0, " s", true);
+            drag(ui, app, "dialog.timeStretch.duration", &mut d.duration, DragSpec { speed: 0.05, range: 0.01..=100000.0, suffix: " s" }, true);
             if (before - d.duration).abs() > 1e-9 && d.orig_duration > 1e-9 {
                 d.percent = d.orig_percent.signum() * d.orig_percent.abs() * d.duration / d.orig_duration;
             }
diff --git a/crates/ui-egui/src/panels/layer_panel.rs b/crates/ui-egui/src/panels/layer_panel.rs
index f6157da47..5fb4d703c 100644
--- a/crates/ui-egui/src/panels/layer_panel.rs
+++ b/crates/ui-egui/src/panels/layer_panel.rs
@@ -87,6 +87,141 @@ fn default_view(layer: &Layer, tool: Tool) -> usize {
     }
 }
 
+/// The layer's rendered view `view` at `scale`, cached in egui's temp data per revision, layer,
+/// time, view and scale (the layer cache makes repeats cheap).
+fn render_tex(
+    app: &EffectcraftApp,
+    ctx: &egui::Context,
+    cid: effectcraft_engine::project::ItemId,
+    comp: &effectcraft_engine::project::Comp,
+    layer: &Layer,
+    view: usize,
+    scale: f64,
+) -> Option<Tex> {
+    let time = app.session.time();
+    let key = (app.session.revision, layer.id.0, time.0, view, (scale * 1000.0) as u32);
+    let cached: Option<Tex> = ctx.data(|d| d.get_temp(tex_id()));
+    match cached {
+        Some(c) if c.key == key => Some(c),
+        _ => {
+            let ectx = EvalCtx { project: &app.session.project, comp_id: cid, comp, time, expr: app.session.expr.as_deref(), footage: None };
+            let mut r = Renderer::new(&app.session.project, &*app.session.footage, RenderOpts { scale, ..Default::default() });
+            r.expr = app.session.expr.as_deref();
+            r.cache = Some(&app.session.layer_cache);
+            r.layer_input(&ectx, layer, view).map(|buf| {
+                let img = crate::frames::to_color_image(&buf.img);
+                let x0 = -buf.offset[0] / buf.scale;
+                let y0 = -buf.offset[1] / buf.scale;
+                let rect = [x0, y0, x0 + buf.img.width as f64 / buf.scale, y0 + buf.img.height as f64 / buf.scale];
+                let tex = crate::frames::load_fitted(ctx, "layer-panel", img, egui::TextureOptions::LINEAR);
+                let c = Tex { key, tex, rect };
+                ctx.data_mut(|d| d.insert_temp(tex_id(), c.clone()));
+                c
+            })
+        }
+    }
+}
+
+/// What [`paint_stroke`] needs about the brush and the layer <-> screen mapping.
+#[derive(Clone, Copy)]
+struct StrokeCtx<'a> {
+    layer: u64,
+    kind: &'a str,
+    zoom: f64,
+    did: egui::Id,
+    diameter: f64,
+    color: [f64; 4],
+    to_layer: &'a dyn Fn(Pos2) -> [f64; 2],
+    to_screen: &'a dyn Fn([f64; 2]) -> Pos2,
+}
+
+/// Records a paint stroke's layer-space points while dragging, previews it, and runs
+/// `paint.stroke` on release (or on a click).
+fn paint_stroke(app: &mut EffectcraftApp, ui: &egui::Ui, painter: &egui::Painter, resp: &egui::Response, sc: &StrokeCtx) {
+    let StrokeCtx { layer, kind, zoom, did, diameter, color, to_layer, to_screen } = *sc;
+    let ctx = ui.ctx().clone();
+    let now = ui.input(|i| i.time);
+    if resp.drag_started()
+        && let Some(pos) = ui.input(|i| i.pointer.press_origin()).or(resp.interact_pointer_pos())
+    {
+        ctx.data_mut(|d| d.insert_temp(did, Drag { layer, points: vec![to_layer(pos)], started: now }));
+    }
+    if let Some(mut d) = ctx.data(|d| d.get_temp::<Drag>(did)) {
+        if let Some(pos) = resp.interact_pointer_pos() {
+            let lp = to_layer(pos);
+            let last = d.points.last().copied().unwrap_or(lp);
+            if (lp[0] - last[0]).hypot(lp[1] - last[1]) * zoom >= 1.0 {
+                d.points.push(lp);
+                ctx.data_mut(|dd| dd.insert_temp(did, d.clone()));
+            }
+        }
+        // Live preview of the stroke.
+        let col = if kind == "eraser" {
+            Color32::from_white_alpha(140)
+        } else {
+            Color32::from_rgba_unmultiplied((color[0] * 255.0) as u8, (color[1] * 255.0) as u8, (color[2] * 255.0) as u8, 200)
+        };
+        let width = ((diameter * zoom) as f32).max(1.0);
+        let pts: Vec<Pos2> = d.points.iter().map(|q| to_screen(*q)).collect();
+        if pts.len() == 1 {
+            painter.circle_filled(pts[0], width / 2.0, col);
+        } else {
+            painter.add(egui::Shape::line(pts, Stroke::new(width, col)));
+        }
+        if resp.drag_stopped() {
+            ctx.data_mut(|dd| dd.remove::<Drag>(did));
+            let pts: Vec<[f64; 2]> = d.points.clone();
+            let r = app.session.execute("paint.stroke", json!({"layer": d.layer, "kind": kind, "points": pts, "duration": (now - d.started).max(0.0)}));
+            if let Err(e) = r {
+                app.ui.status = e.to_string();
+            }
+        }
+    }
+    if resp.clicked()
+        && let Some(pos) = resp.interact_pointer_pos()
+    {
+        let r = app.session.execute("paint.stroke", json!({"layer": layer, "kind": kind, "points": [to_layer(pos)], "duration": 0.0}));
+        if let Err(e) = r {
+            app.ui.status = e.to_string();
+        }
+    }
+}
+
+/// The bottom bar: the magnification menu and the View menu over `names` (Masks, then the
+/// effects). Returns where the View dropdown ends.
+fn bottom_bar(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, bar: Rect, names: &[String], view: usize, (zoom, fit): (f64, f32)) -> f32 {
+    let t = app.tokens;
+    p.rect_filled(bar, 0.0, t.panel_bg);
+    let mr = Rect::from_min_size(pos2(bar.min.x + 8.0, bar.center().y - 10.0), vec2(80.0, 20.0));
+    if let Some((z, up)) = super::viewer_tools::magnification_menu(
+        app,
+        ui,
+        mr,
+        "layer-mag",
+        "layerPanel.magnification",
+        "layerMagnification",
+        zoom as f32,
+        app.ui.layer_zoom,
+        false,
+    ) {
+        // The Layer panel keeps no fit mode: Fit up to 100% is the fit, at most 100 %.
+        app.ui.layer_zoom = if up { Some(fit.min(1.0 / ui.ctx().pixels_per_point())) } else { z };
+        app.ui.layer_pan = [0.0, 0.0];
+    }
+    let vx = mr.max.x + 10.0;
+    p.text(pos2(vx, bar.center().y), Align2::LEFT_CENTER, tr("View:"), Tokens::ui(12.0), t.text_dim);
+    let vr = Rect::from_min_size(pos2(vx + 36.0, bar.center().y - 10.0), vec2(150.0, 20.0));
+    let pop = egui::Id::unique("layer-view-pop");
+    if widgets::dropdown(ui, vr, &names[view.min(names.len() - 1)], &t, egui::Id::unique("layer-view")).clicked() {
+        widgets::open_popup(ui, pop);
+    }
+    app.auto.add("layerPanel.view", vr, "View");
+    if let Some(i) = widgets::popup_menu(ui, pop, vr.left_bottom(), names, Some(view)) {
+        app.ui.layer_view = Some(i);
+    }
+    vr.max.x
+}
+
 /// The Layer panel: one layer in its own space with its masks and effects up to the View menu's
 /// choice, rendered synchronously at a zoom/pan the panel keeps (the last Fit magnification is
 /// published for the View menu). Wheel or pinch zooms about the pointer, the Hand tool or
@@ -130,44 +265,17 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     };
     let origin = area.center() + pan - vec2((lw * zoom / 2.0) as f32, (lh * zoom / 2.0) as f32);
 
-    // Bottom bar: magnification and View menus.
-    p.rect_filled(bar, 0.0, t.panel_bg);
-    let mr = Rect::from_min_size(pos2(bar.min.x + 8.0, bar.center().y - 10.0), vec2(80.0, 20.0));
-    if let Some((z, up)) = super::viewer_tools::magnification_menu(
-        app,
-        ui,
-        mr,
-        "layer-mag",
-        "layerPanel.magnification",
-        "layerMagnification",
-        zoom as f32,
-        app.ui.layer_zoom,
-        false,
-    ) {
-        // The Layer panel keeps no fit mode: Fit up to 100% is the fit, at most 100 %.
-        app.ui.layer_zoom = if up { Some(fit.min(1.0 / ui.ctx().pixels_per_point())) } else { z };
-        app.ui.layer_pan = [0.0, 0.0];
-    }
-    let vx = mr.max.x + 10.0;
-    p.text(pos2(vx, bar.center().y), Align2::LEFT_CENTER, tr("View:"), Tokens::ui(12.0), t.text_dim);
     let mut names = vec!["Masks".to_string()];
     if let Some(fx) = layer.effects() {
         names.extend(fx.groups().map(|g| g.name.clone()));
     }
-    let vr = Rect::from_min_size(pos2(vx + 36.0, bar.center().y - 10.0), vec2(150.0, 20.0));
-    let pop = egui::Id::unique("layer-view-pop");
-    if widgets::dropdown(ui, vr, &names[view.min(names.len() - 1)], &t, egui::Id::unique("layer-view")).clicked() {
-        widgets::open_popup(ui, pop);
-    }
-    app.auto.add("layerPanel.view", vr, "View");
-    if let Some(i) = widgets::popup_menu(ui, pop, vr.left_bottom(), &names, Some(view)) {
-        app.ui.layer_view = Some(i);
-    }
+    let vr_right = bottom_bar(app, ui, &p, bar, &names, view, (zoom, fit));
+
     let tc = super::timecode(&app.session, &comp, time);
     p.text(pos2(bar.max.x - 10.0, bar.center().y), Align2::RIGHT_CENTER, tc, Tokens::mono(12.0), t.timecode);
     // Roto Brush: view / Freeze buttons and the segmentation span bar.
     if roto.is_some() {
-        super::roto_tool::bar_buttons(app, ui, &p, bar, vr.max.x + 12.0, &layer);
+        super::roto_tool::bar_buttons(app, ui, &p, bar, vr_right + 12.0, &layer);
         let sb = Rect::from_min_max(pos2(rect.min.x, canvas_bottom), pos2(rect.max.x, bar.min.y));
         super::roto_tool::span_bar(app, ui, &p, sb, &comp, &layer);
     }
@@ -190,27 +298,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     } else {
         0.25
     };
-    let key = (app.session.revision, layer.id.0, time.0, view, (scale * 1000.0) as u32);
-    let cached: Option<Tex> = ctx.data(|d| d.get_temp(tex_id()));
-    let tex = match cached {
-        Some(c) if c.key == key => Some(c),
-        _ => {
-            let ectx = EvalCtx { project: &app.session.project, comp_id: cid, comp: &comp, time, expr: app.session.expr.as_deref(), footage: None };
-            let mut r = Renderer::new(&app.session.project, &*app.session.footage, RenderOpts { scale, ..Default::default() });
-            r.expr = app.session.expr.as_deref();
-            r.cache = Some(&app.session.layer_cache);
-            r.layer_input(&ectx, &layer, view).map(|buf| {
-                let img = crate::frames::to_color_image(&buf.img);
-                let x0 = -buf.offset[0] / buf.scale;
-                let y0 = -buf.offset[1] / buf.scale;
-                let rect = [x0, y0, x0 + buf.img.width as f64 / buf.scale, y0 + buf.img.height as f64 / buf.scale];
-                let tex = crate::frames::load_fitted(&ctx, "layer-panel", img, egui::TextureOptions::LINEAR);
-                let c = Tex { key, tex, rect };
-                ctx.data_mut(|d| d.insert_temp(tex_id(), c.clone()));
-                c
-            })
-        }
-    };
+    let tex = render_tex(app, &ctx, cid, &comp, &layer, view, scale);
     if let Some(tx) = &tex {
         let r = Rect::from_min_max(to_screen([tx.rect[0], tx.rect[1]]), to_screen([tx.rect[2], tx.rect[3]]));
         painter.image(tx.tex.id(), r, Rect::from_min_max(pos2(0.0, 0.0), pos2(1.0, 1.0)), Color32::WHITE);
@@ -271,7 +359,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
     // Interaction: Roto Brush / Refine Edge.
     if app.ui.tool.roto_kind(false).is_some() {
-        super::roto_tool::interact(app, ui, &painter, area, &layer, zoom, &to_screen, &to_layer);
+        super::roto_tool::interact(app, ui, &painter, area, &layer, zoom, super::roto_tool::LayerXform { to_screen: &to_screen, to_layer: &to_layer });
         return;
     }
     // Interaction: paint tools.
@@ -314,7 +402,6 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         painter.line_segment([s - vec2(0.0, 6.0), s + vec2(0.0, 6.0)], Stroke::new(1.0, Color32::WHITE));
     }
     let mods = ui.input(|i| i.modifiers);
-    let now = ui.input(|i| i.time);
     // Alt/Option-click with the Clone Stamp sets the source.
     if app.ui.tool == Tool::Clone
         && mods.alt
@@ -328,49 +415,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     if let Some(kind) = kind
         && !mods.alt
     {
-        if resp.drag_started()
-            && let Some(pos) = ui.input(|i| i.pointer.press_origin()).or(resp.interact_pointer_pos())
-        {
-            ctx.data_mut(|d| d.insert_temp(did, Drag { layer: layer.id.0, points: vec![to_layer(pos)], started: now }));
-        }
-        if let Some(mut d) = ctx.data(|d| d.get_temp::<Drag>(did)) {
-            if let Some(pos) = resp.interact_pointer_pos() {
-                let lp = to_layer(pos);
-                let last = d.points.last().copied().unwrap_or(lp);
-                if (lp[0] - last[0]).hypot(lp[1] - last[1]) * zoom >= 1.0 {
-                    d.points.push(lp);
-                    ctx.data_mut(|dd| dd.insert_temp(did, d.clone()));
-                }
-            }
-            // Live preview of the stroke.
-            let col = if kind == "eraser" {
-                Color32::from_white_alpha(140)
-            } else {
-                Color32::from_rgba_unmultiplied((o.color[0] * 255.0) as u8, (o.color[1] * 255.0) as u8, (o.color[2] * 255.0) as u8, 200)
-            };
-            let width = ((o.diameter * zoom) as f32).max(1.0);
-            let pts: Vec<Pos2> = d.points.iter().map(|q| to_screen(*q)).collect();
-            if pts.len() == 1 {
-                painter.circle_filled(pts[0], width / 2.0, col);
-            } else {
-                painter.add(egui::Shape::line(pts, Stroke::new(width, col)));
-            }
-            if resp.drag_stopped() {
-                ctx.data_mut(|dd| dd.remove::<Drag>(did));
-                let pts: Vec<[f64; 2]> = d.points.clone();
-                let r = app.session.execute("paint.stroke", json!({"layer": d.layer, "kind": kind, "points": pts, "duration": (now - d.started).max(0.0)}));
-                if let Err(e) = r {
-                    app.ui.status = e.to_string();
-                }
-            }
-        }
-        if resp.clicked()
-            && let Some(pos) = resp.interact_pointer_pos()
-        {
-            let r = app.session.execute("paint.stroke", json!({"layer": layer.id.0, "kind": kind, "points": [to_layer(pos)], "duration": 0.0}));
-            if let Err(e) = r {
-                app.ui.status = e.to_string();
-            }
-        }
+        let stroke = StrokeCtx { layer: layer.id.0, kind, zoom, did, diameter: o.diameter, color: o.color, to_layer: &to_layer, to_screen: &to_screen };
+        paint_stroke(app, ui, &painter, &resp, &stroke);
     }
 }
diff --git a/crates/ui-egui/src/panels/layer_styles_dialog.rs b/crates/ui-egui/src/panels/layer_styles_dialog.rs
index a4af4dae2..14507b868 100644
--- a/crates/ui-egui/src/panels/layer_styles_dialog.rs
+++ b/crates/ui-egui/src/panels/layer_styles_dialog.rs
@@ -91,7 +91,7 @@ fn control(ui: &mut egui::Ui, p: &Property, v: &KV) -> Option<Value> {
         }
         (KV::Enum(i), ParamUi::Popup { options }) => {
             let mut sel = *i as usize;
-            egui::ComboBox::from_id_salt(("ls-popup", p.uid)).selected_text(options.get(sel).cloned().unwrap_or_default()).show_ui(ui, |ui| {
+            craft_ui::ComboBox::from_id_salt(("ls-popup", p.uid)).selected_text(options.get(sel).cloned().unwrap_or_default()).show_ui(ui, |ui| {
                 for (k, o) in options.iter().enumerate() {
                     ui.selectable_value(&mut sel, k, o);
                 }
diff --git a/crates/ui-egui/src/panels/markers_ui.rs b/crates/ui-egui/src/panels/markers_ui.rs
index a696e8ca6..14e774f67 100644
--- a/crates/ui-egui/src/panels/markers_ui.rs
+++ b/crates/ui-egui/src/panels/markers_ui.rs
@@ -197,7 +197,7 @@ pub fn dialog(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
             ui.label(tr("Label:"));
             let labels = effectcraft_engine::color::Label::ALL;
             let cur = labels.get(d.label).copied().unwrap_or_default();
-            let r = egui::ComboBox::from_id_salt("dialog.marker.label").selected_text(app.session.prefs.label_name(cur)).show_ui(ui, |ui| {
+            let r = craft_ui::ComboBox::from_id_salt("dialog.marker.label").selected_text(app.session.prefs.label_name(cur)).show_ui(ui, |ui| {
                 for (i, l) in labels.into_iter().enumerate() {
                     if crate::widgets::label_entry(ui, l, &app.session.prefs.label_name(l), d.label == i, &app.tokens).clicked() {
                         d.label = i;
diff --git a/crates/ui-egui/src/panels/media_panels.rs b/crates/ui-egui/src/panels/media_panels.rs
index e07b25766..ffe2cc1f7 100644
--- a/crates/ui-egui/src/panels/media_panels.rs
+++ b/crates/ui-egui/src/panels/media_panels.rs
@@ -63,6 +63,27 @@ fn thumbnail(app: &EffectcraftApp, ctx: &egui::Context, path: &str, budget: &mut
     thumb
 }
 
+/// The Favorites column: one clickable row per place, the current folder `dir` highlighted.
+fn places_column(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, side: Rect, places: &[(String, String)], dir: &str) {
+    let t = app.tokens;
+    let mut fy = side.min.y + 22.0;
+    for (i, (name, path)) in places.iter().enumerate() {
+        let r = Rect::from_min_size(pos2(side.min.x, fy), vec2(side.width(), 20.0));
+        let resp = ui.interact(r, egui::Id::unique(("mb-fav", i)), Sense::click());
+        if path == dir {
+            p.rect_filled(r, 0.0, t.row_selected);
+        } else if resp.hovered() {
+            p.rect_filled(r, 0.0, t.hover);
+        }
+        p.text(pos2(r.min.x + 14.0, r.center().y), Align2::LEFT_CENTER, name, Tokens::ui(12.0), t.text);
+        app.auto.add(&format!("mediaBrowser.place.{i}"), r, name);
+        if resp.clicked() {
+            kit::exec(app, "mediaBrowser.go", json!({"path": path}));
+        }
+        fy += 20.0;
+    }
+}
+
 /// The Media Browser panel: a toolbar (up, home, favourite, "Media only" filter and the browser's
 /// own actions), the current path, the favourite places and a tile grid of the folder's entries
 /// with thumbnails for images and videos. Double-click opens a folder or imports a file; files
@@ -136,26 +157,11 @@ pub fn media_browser(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let side = Rect::from_min_max(pos2(rect.min.x, rect.min.y + 54.0), pos2(rect.min.x + 160.0_f32.min(rect.width() * 0.3), rect.max.y));
     p.line_segment([side.right_top(), side.right_bottom()], Stroke::new(1.0, t.separator));
     p.text(pos2(side.min.x + 10.0, side.min.y + 10.0), Align2::LEFT_CENTER, tr("Favorites"), Tokens::semibold(11.5), t.text_dim);
-    let mut fy = side.min.y + 22.0;
     let mut places: Vec<(String, String)> = b.places();
     places.extend(
         st.favorites.iter().map(|f| (std::path::Path::new(f).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| f.clone()), f.clone())),
     );
-    for (i, (name, path)) in places.iter().enumerate() {
-        let r = Rect::from_min_size(pos2(side.min.x, fy), vec2(side.width(), 20.0));
-        let resp = ui.interact(r, egui::Id::unique(("mb-fav", i)), Sense::click());
-        if *path == dir {
-            p.rect_filled(r, 0.0, t.row_selected);
-        } else if resp.hovered() {
-            p.rect_filled(r, 0.0, t.hover);
-        }
-        p.text(pos2(r.min.x + 14.0, r.center().y), Align2::LEFT_CENTER, name, Tokens::ui(12.0), t.text);
-        app.auto.add(&format!("mediaBrowser.place.{i}"), r, name);
-        if resp.clicked() {
-            kit::exec(app, "mediaBrowser.go", json!({"path": path}));
-        }
-        fy += 20.0;
-    }
+    places_column(app, ui, &p, side, &places, &dir);
     // Files.
     let list = Rect::from_min_max(pos2(side.max.x + 1.0, side.min.y), rect.max);
     let entries = match entries.as_ref() {
diff --git a/crates/ui-egui/src/panels/misc.rs b/crates/ui-egui/src/panels/misc.rs
index bd0e716b4..dfa9a42e0 100644
--- a/crates/ui-egui/src/panels/misc.rs
+++ b/crates/ui-egui/src/panels/misc.rs
@@ -117,7 +117,14 @@ pub fn preview(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         for (k, (key, text, v)) in [("preRoll", "Pre-roll", o.pre_roll), ("postRoll", "Post-roll", o.post_roll)].into_iter().enumerate() {
             let lx = xv + k as f32 * 100.0;
             p.text(pos2(lx, yy), Align2::LEFT_CENTER, text, Tokens::ui(11.5), t.text_dim);
-            let (r, nv, _) = widgets::hot_number_at(ui, pos2(lx + 52.0, yy - 9.0), egui::Id::unique(("pv-roll", key)), v, 0.05, (0.0, 600.0), 1, "s", &t);
+            let (r, nv, _) = widgets::hot_number_at(
+                ui,
+                pos2(lx + 52.0, yy - 9.0),
+                egui::Id::unique(("pv-roll", key)),
+                v,
+                &widgets::HotSpec { speed: 0.05, range: (0.0, 600.0), decimals: 1, suffix: "s" },
+                &t,
+            );
             app.auto.add(&format!("preview.{key}"), r, text);
             if let Some(nv) = nv {
                 changes.push(json!({"shortcut": current.id(), key: nv}));
@@ -160,7 +167,14 @@ pub fn preview(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
     let sx = xv + 106.0;
     p.text(pos2(sx, yy), Align2::LEFT_CENTER, tr("Skip"), Tokens::ui(12.0), t.text_dim);
-    let (r, nv, _) = widgets::hot_number_at(ui, pos2(sx + 30.0, yy - 9.0), egui::Id::unique("pv-skip"), o.skip as f64, 0.1, (0.0, 99.0), 0, "", &t);
+    let (r, nv, _) = widgets::hot_number_at(
+        ui,
+        pos2(sx + 30.0, yy - 9.0),
+        egui::Id::unique("pv-skip"),
+        o.skip as f64,
+        &widgets::HotSpec { speed: 0.1, range: (0.0, 99.0), decimals: 0, suffix: "" },
+        &t,
+    );
     app.auto.add("preview.skip", r, "Skip");
     if let Some(nv) = nv {
         changes.push(json!({"shortcut": current.id(), "skip": nv.round() as u32}));
@@ -181,8 +195,14 @@ pub fn preview(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         changes.push(json!({"shortcut": current.id(), "resolution": res_ids[i]}));
     }
     if o.resolution == PreviewResolution::Custom {
-        let (r, nv, _) =
-            widgets::hot_number_at(ui, pos2(xv + 106.0, yy - 9.0), egui::Id::unique("pv-custom-res"), o.custom_resolution as f64, 0.1, (1.0, 40.0), 0, "", &t);
+        let (r, nv, _) = widgets::hot_number_at(
+            ui,
+            pos2(xv + 106.0, yy - 9.0),
+            egui::Id::unique("pv-custom-res"),
+            o.custom_resolution as f64,
+            &widgets::HotSpec { speed: 0.1, range: (1.0, 40.0), decimals: 0, suffix: "" },
+            &t,
+        );
         app.auto.add("preview.customResolution", r, "Custom Resolution");
         if let Some(nv) = nv {
             changes.push(json!({"shortcut": current.id(), "customResolution": nv.round() as u32}));
diff --git a/crates/ui-egui/src/panels/paint_panels.rs b/crates/ui-egui/src/panels/paint_panels.rs
index 43e4d438c..c867eb63a 100644
--- a/crates/ui-egui/src/panels/paint_panels.rs
+++ b/crates/ui-egui/src/panels/paint_panels.rs
@@ -36,7 +36,14 @@ fn number(
     let t = app.tokens;
     p.text(pos2(x, y + 9.0), Align2::LEFT_CENTER, label, Tokens::ui(11.5), if enabled { t.text_dim } else { t.text_faint });
     let lw = p.layout_no_wrap(label.to_string(), Tokens::ui(11.5), t.text).size().x;
-    let (r, nv, _) = widgets::hot_number_at(ui, pos2(x + lw + 6.0, y), egui::Id::unique(("paint-num", key)), v, 0.5, range, 0, suffix, &t);
+    let (r, nv, _) = widgets::hot_number_at(
+        ui,
+        pos2(x + lw + 6.0, y),
+        egui::Id::unique(("paint-num", key)),
+        v,
+        &widgets::HotSpec { speed: 0.5, range, decimals: 0, suffix },
+        &t,
+    );
     app.auto.add(key, r, label);
     nv.filter(|_| enabled)
 }
@@ -83,6 +90,48 @@ fn paint_swap_icon(p: &egui::Painter, rect: Rect, color: Color32) {
     p.arrow(pos2(right, bottom), vec2(left - right, 0.0), stroke);
 }
 
+/// The foreground-over-background swatches (each opens a colour popup) with Swap and Reset.
+fn colour_swatches(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, x0: f32, y: f32, color: [f64; 4], background: [f64; 4]) {
+    let t = app.tokens;
+    let fg = Rect::from_min_size(pos2(x0, y), vec2(26.0, 20.0));
+    let bg = Rect::from_min_size(pos2(x0 + 14.0, y + 10.0), vec2(26.0, 20.0));
+    widgets::swatch(ui, bg, [background[0] as f32, background[1] as f32, background[2] as f32, 1.0], egui::Id::unique("paint-bg"), &t);
+    let bresp = ui.interact(Rect::from_min_max(pos2(fg.max.x, bg.min.y), bg.max), egui::Id::unique("paint-bg-hit"), Sense::click());
+    if bresp.clicked() {
+        widgets::open_popup(ui, egui::Id::unique("paint-bg-pop"));
+    }
+    if widgets::swatch(ui, fg, [color[0] as f32, color[1] as f32, color[2] as f32, 1.0], egui::Id::unique("paint-fg"), &t).clicked() {
+        widgets::open_popup(ui, egui::Id::unique("paint-fg-pop"));
+    }
+    app.auto.add("paint.color", fg, "Foreground color");
+    app.auto.add("paint.background", bg, "Background color");
+    let mut fc = rgb(color);
+    if crate::widgets::color_popup(ui, egui::Id::unique("paint-fg-pop"), fg.left_bottom(), &mut fc) {
+        set(app, json!({"color": [fc[0], fc[1], fc[2], 1.0]}));
+    }
+    let mut bc = rgb(background);
+    if crate::widgets::color_popup(ui, egui::Id::unique("paint-bg-pop"), bg.left_bottom(), &mut bc) {
+        set(app, json!({"background": [bc[0], bc[1], bc[2], 1.0]}));
+    }
+    let swap = Rect::from_min_size(pos2(x0 + 46.0, y), vec2(18.0, 14.0));
+    let sresp = ui.interact(swap, egui::Id::unique("paint-swap"), Sense::click());
+    // Two arrows (foreground over background): drawn, so the icon does not depend on a font
+    // carrying U+21C4 (the bundled fonts do not).
+    paint_swap_icon(p, swap, if sresp.hovered() { t.text } else { t.text_dim });
+    app.auto.add("paint.swapColors", swap, "Swap colors");
+    if sresp.on_hover_text(tr("Swap Paint Colors (X)")).clicked() {
+        set(app, json!({"color": background, "background": color}));
+    }
+    let reset = Rect::from_min_size(pos2(x0 + 46.0, y + 18.0), vec2(18.0, 14.0));
+    let rresp = ui.interact(reset, egui::Id::unique("paint-reset-colors"), Sense::click());
+    p.rect_filled(Rect::from_min_size(reset.min + vec2(4.0, 3.0), vec2(7.0, 6.0)), 0.0, Color32::WHITE);
+    p.rect_stroke(Rect::from_min_size(reset.min + vec2(8.0, 6.0), vec2(7.0, 6.0)), 0.0, Stroke::new(1.0, t.text_dim), StrokeKind::Inside);
+    app.auto.add("paint.resetColors", reset, "Default colors");
+    if rresp.on_hover_text(tr("Set Paint Colors to Black and White (D)")).clicked() {
+        set(app, json!({"color": [1.0, 1.0, 1.0, 1.0], "background": [0.0, 0.0, 0.0, 1.0]}));
+    }
+}
+
 /// The Paint panel: opacity and flow, foreground/background colours with swap and reset, mode,
 /// channels, duration, erase mode and the Clone Stamp options. Every change is sent as a
 /// `paint.options` command. Mode and Channels are disabled for the Eraser; Erase is enabled
@@ -106,43 +155,7 @@ pub fn paint(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
     y += 28.0;
     // Colour swatches (foreground over background) with swap / reset.
-    let fg = Rect::from_min_size(pos2(x0, y), vec2(26.0, 20.0));
-    let bg = Rect::from_min_size(pos2(x0 + 14.0, y + 10.0), vec2(26.0, 20.0));
-    widgets::swatch(ui, bg, [o.background[0] as f32, o.background[1] as f32, o.background[2] as f32, 1.0], egui::Id::unique("paint-bg"), &t);
-    let bresp = ui.interact(Rect::from_min_max(pos2(fg.max.x, bg.min.y), bg.max), egui::Id::unique("paint-bg-hit"), Sense::click());
-    if bresp.clicked() {
-        widgets::open_popup(ui, egui::Id::unique("paint-bg-pop"));
-    }
-    if widgets::swatch(ui, fg, [o.color[0] as f32, o.color[1] as f32, o.color[2] as f32, 1.0], egui::Id::unique("paint-fg"), &t).clicked() {
-        widgets::open_popup(ui, egui::Id::unique("paint-fg-pop"));
-    }
-    app.auto.add("paint.color", fg, "Foreground color");
-    app.auto.add("paint.background", bg, "Background color");
-    let mut fc = rgb(o.color);
-    if crate::widgets::color_popup(ui, egui::Id::unique("paint-fg-pop"), fg.left_bottom(), &mut fc) {
-        set(app, json!({"color": [fc[0], fc[1], fc[2], 1.0]}));
-    }
-    let mut bc = rgb(o.background);
-    if crate::widgets::color_popup(ui, egui::Id::unique("paint-bg-pop"), bg.left_bottom(), &mut bc) {
-        set(app, json!({"background": [bc[0], bc[1], bc[2], 1.0]}));
-    }
-    let swap = Rect::from_min_size(pos2(x0 + 46.0, y), vec2(18.0, 14.0));
-    let sresp = ui.interact(swap, egui::Id::unique("paint-swap"), Sense::click());
-    // Two arrows (foreground over background): drawn, so the icon does not depend on a font
-    // carrying U+21C4 (the bundled fonts do not).
-    paint_swap_icon(&p, swap, if sresp.hovered() { t.text } else { t.text_dim });
-    app.auto.add("paint.swapColors", swap, "Swap colors");
-    if sresp.on_hover_text(tr("Swap Paint Colors (X)")).clicked() {
-        set(app, json!({"color": o.background, "background": o.color}));
-    }
-    let reset = Rect::from_min_size(pos2(x0 + 46.0, y + 18.0), vec2(18.0, 14.0));
-    let rresp = ui.interact(reset, egui::Id::unique("paint-reset-colors"), Sense::click());
-    p.rect_filled(Rect::from_min_size(reset.min + vec2(4.0, 3.0), vec2(7.0, 6.0)), 0.0, Color32::WHITE);
-    p.rect_stroke(Rect::from_min_size(reset.min + vec2(8.0, 6.0), vec2(7.0, 6.0)), 0.0, Stroke::new(1.0, t.text_dim), StrokeKind::Inside);
-    app.auto.add("paint.resetColors", reset, "Default colors");
-    if rresp.on_hover_text(tr("Set Paint Colors to Black and White (D)")).clicked() {
-        set(app, json!({"color": [1.0, 1.0, 1.0, 1.0], "background": [0.0, 0.0, 0.0, 1.0]}));
-    }
+    colour_swatches(app, ui, &p, x0, y, o.color, o.background);
     y += 40.0;
 
     // Mode / Channels / Duration.
@@ -167,10 +180,7 @@ pub fn paint(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             pos2(x0 + w - 52.0, y + 1.0),
             egui::Id::unique("paint-custom-frames"),
             o.custom_frames as f64,
-            0.2,
-            (1.0, 10000.0),
-            0,
-            " f",
+            &widgets::HotSpec { speed: 0.2, range: (1.0, 10000.0), decimals: 0, suffix: " f" },
             &t,
         );
         app.auto.add("paint.customFrames", r, "Custom duration (frames)");
@@ -239,7 +249,14 @@ pub fn paint(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let off = o.clone_offset.unwrap_or([0.0, 0.0]);
     p.text(pos2(x0, y + 9.0), Align2::LEFT_CENTER, tr("Offset:"), Tokens::ui(11.5), t.text_dim);
     for (d, v) in off.iter().enumerate() {
-        let (r, nv, _) = widgets::hot_number_at(ui, pos2(x0 + 56.0 + d as f32 * 64.0, y), egui::Id::unique(("clone-off", d)), *v, 1.0, (-1e5, 1e5), 0, "", &t);
+        let (r, nv, _) = widgets::hot_number_at(
+            ui,
+            pos2(x0 + 56.0 + d as f32 * 64.0, y),
+            egui::Id::unique(("clone-off", d)),
+            *v,
+            &widgets::HotSpec { speed: 1.0, range: (-1e5, 1e5), decimals: 0, suffix: "" },
+            &t,
+        );
         app.auto.add(&format!("paint.cloneOffset.{d}"), r, "Clone offset");
         if let Some(nv) = nv {
             let mut no = off;
@@ -354,7 +371,14 @@ pub fn brushes(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     // Spacing (checkbox in AE turns spacing on; we always space dabs, so it shows the value).
     p.text(pos2(x0, y + 9.0), Align2::LEFT_CENTER, tr("Spacing:"), Tokens::ui(11.5), t.text_dim);
     let _ = r;
-    let (sr, nv, _) = widgets::hot_number_at(ui, pos2(x0 + 58.0, y), egui::Id::unique("brushes-spacing"), o.spacing, 0.5, (1.0, 1000.0), 0, " %", &t);
+    let (sr, nv, _) = widgets::hot_number_at(
+        ui,
+        pos2(x0 + 58.0, y),
+        egui::Id::unique("brushes-spacing"),
+        o.spacing,
+        &widgets::HotSpec { speed: 0.5, range: (1.0, 1000.0), decimals: 0, suffix: " %" },
+        &t,
+    );
     app.auto.add("brushes.spacing", sr, "Spacing");
     if let Some(nv) = nv {
         set(app, json!({"spacing": nv}));
diff --git a/crates/ui-egui/src/panels/panel_kit.rs b/crates/ui-egui/src/panels/panel_kit.rs
index 99554ec57..501ddf64f 100644
--- a/crates/ui-egui/src/panels/panel_kit.rs
+++ b/crates/ui-egui/src/panels/panel_kit.rs
@@ -47,7 +47,7 @@ pub fn label(ui: &egui::Ui, at: egui::Pos2, text: &str, t: &Tokens) {
 #[allow(clippy::too_many_arguments)]
 pub fn number(app: &mut EffectcraftApp, ui: &mut egui::Ui, at: egui::Pos2, auto: &str, v: f64, speed: f64, range: (f64, f64), dec: usize, suffix: &str) -> f64 {
     let t = app.tokens;
-    let (r, nv, _) = widgets::hot_number_at(ui, at, egui::Id::unique(("kit-n", auto)), v, speed, range, dec, suffix, &t);
+    let (r, nv, _) = widgets::hot_number_at(ui, at, egui::Id::unique(("kit-n", auto)), v, &widgets::HotSpec { speed, range, decimals: dec, suffix }, &t);
     app.auto.add(auto, r, &format!("{v}"));
     nv.unwrap_or(v)
 }
diff --git a/crates/ui-egui/src/panels/primitive_dialog.rs b/crates/ui-egui/src/panels/primitive_dialog.rs
index a3483a976..3711c6a80 100644
--- a/crates/ui-egui/src/panels/primitive_dialog.rs
+++ b/crates/ui-egui/src/panels/primitive_dialog.rs
@@ -58,7 +58,7 @@ pub fn dialog(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
     super::dialogs::modal(ctx, "New 3D Primitive", vec2(420.0, 300.0), t, |ui| {
         egui::Grid::new("primitive-grid").num_columns(2).spacing([14.0, 9.0]).show(ui, |ui| {
             ui.label(tr("Type"));
-            let combo = egui::ComboBox::from_id_salt("primitive-type").selected_text(tr(d.kind.label())).show_ui(ui, |ui| {
+            let combo = craft_ui::ComboBox::from_id_salt("primitive-type").selected_text(tr(d.kind.label())).show_ui(ui, |ui| {
                 for (i, k) in PrimitiveKind::ALL.into_iter().enumerate() {
                     let item = ui.selectable_value(&mut d.kind, k, tr(k.label()));
                     app.auto.add(&format!("dialog.primitive.typeItem.{i}"), item.rect, k.label());
diff --git a/crates/ui-egui/src/panels/project.rs b/crates/ui-egui/src/panels/project.rs
index 0d2769541..1944f333f 100644
--- a/crates/ui-egui/src/panels/project.rs
+++ b/crates/ui-egui/src/panels/project.rs
@@ -381,17 +381,9 @@ pub(crate) fn reveal(app: &mut EffectcraftApp, ctx: &egui::Context, items: &[Ite
     app.show_panel(crate::dock::PanelKind::Project);
 }
 
-/// The Project panel: the selected item's thumbnail and details (with the comps that use it), the
-/// search field, sortable column headers, and the item rows (folders, comps, footage and solids)
-/// with selection, Shift/Cmd ranges, keyboard navigation, inline rename, drag-and-drop move,
-/// marquee selection and context menus. Only the rows in view are drawn. File commands are queued
-/// and run through [`crate::menus::invoke`] at the end, with failures shown in `app.ui.status`.
-pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+/// The selected item's thumbnail and details (with the comps that use it), or a hint.
+fn details_header(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, ctx: &egui::Context, head: Rect) {
     let t = app.tokens;
-    let p = ui.painter().clone();
-    let ctx = ui.ctx().clone();
-    // Preview header.
-    let head = Rect::from_min_size(rect.min, vec2(rect.width(), 74.0));
     let sel = app.session.state.project_selection.first().copied();
     if let Some(it) = sel.and_then(|i| app.session.project.item(i)).cloned() {
         let thumb = Rect::from_min_size(head.min + vec2(10.0, 10.0), vec2(96.0, 54.0));
@@ -400,12 +392,12 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             ItemKind::Solid(s) => {
                 p.rect_filled(thumb.shrink(4.0), 2.0, Color32::from_rgb((s.color[0] * 255.0) as u8, (s.color[1] * 255.0) as u8, (s.color[2] * 255.0) as u8));
             }
-            _ => match thumbnail(app, &ctx, &it) {
+            _ => match thumbnail(app, ctx, &it) {
                 Some(tex) => {
                     let [w, h] = tex.size();
                     p.image(tex.id(), fit(thumb, w as f32, h as f32), Rect::from_min_max(pos2(0.0, 0.0), pos2(1.0, 1.0)), Color32::WHITE);
                 }
-                None => icons::paint(&p, Rect::from_center_size(thumb.center(), vec2(24.0, 24.0)), item_icon(&it), t.text_dim),
+                None => icons::paint(p, Rect::from_center_size(thumb.center(), vec2(24.0, 24.0)), item_icon(&it), t.text_dim),
             },
         }
         app.auto.add("project.thumbnail", thumb, &it.name);
@@ -418,7 +410,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         let count = users.iter().fold(0usize, |n, (_, k)| n.saturating_add(*k));
         let name_y = thumb.min.y + 6.0;
         if count == 0 {
-            let r = widgets::text_fit(&p, pos2(tx, name_y), Align2::LEFT_CENTER, &it.name, Tokens::semibold(12.0), max_w, t.text);
+            let r = widgets::text_fit(p, pos2(tx, name_y), Align2::LEFT_CENTER, &it.name, Tokens::semibold(12.0), max_w, t.text);
             app.auto.add("project.details.name", r, &it.name);
         } else {
             let used = if count == 1 { crate::i18n::tr("used once").to_owned() } else { crate::i18n::tr_args("used {} times", &[&count]) };
@@ -427,17 +419,17 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             let arrow_w = 14.0;
             // The name gives way first, but keeps at least half the room; the count is cut after it.
             let name_max = (max_w - arrow_w - used_w).max(max_w * 0.5);
-            let r = widgets::text_fit(&p, pos2(tx, name_y), Align2::LEFT_CENTER, &it.name, Tokens::semibold(12.0), name_max, t.text);
+            let r = widgets::text_fit(p, pos2(tx, name_y), Align2::LEFT_CENTER, &it.name, Tokens::semibold(12.0), name_max, t.text);
             app.auto.add("project.details.name", r, &it.name);
             let ar = Rect::from_min_size(pos2(r.max.x + 1.0, name_y - 7.0), vec2(arrow_w, 14.0));
             let tip = crate::i18n::tr("Compositions that use this item");
             let aresp = ui.interact(ar, egui::Id::unique("proj-used-in"), Sense::click()).on_hover_text(tip);
-            icons::paint(&p, Rect::from_center_size(ar.center(), vec2(9.0, 9.0)), Icon::ChevronDown, if aresp.hovered() { t.text } else { t.text_dim });
+            icons::paint(p, Rect::from_center_size(ar.center(), vec2(9.0, 9.0)), Icon::ChevronDown, if aresp.hovered() { t.text } else { t.text_dim });
             app.auto.add("project.details.usedIn", ar, tip);
             // The comma sits right after the arrow (its glyph ends short of the hit area).
             let ux = ar.max.x - 3.0;
             let room = (head.max.x - 10.0 - ux).max(0.0);
-            let ur = widgets::text_fit(&p, pos2(ux, name_y), Align2::LEFT_CENTER, &used, Tokens::ui(11.0), room, t.text_dim);
+            let ur = widgets::text_fit(p, pos2(ux, name_y), Align2::LEFT_CENTER, &used, Tokens::ui(11.0), room, t.text_dim);
             app.auto.add("project.details.used", ur, &used);
             let names: Vec<(u64, String, usize)> =
                 users.iter().map(|(cid, n)| (cid.0, app.session.project.item(*cid).map(|c| c.name.clone()).unwrap_or_default(), *n)).collect();
@@ -454,7 +446,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 }
             });
             if let Some(cid) = open
-                && let Err(e) = crate::menus::invoke(app, &ctx, "comp.open", json!({"comp": cid}))
+                && let Err(e) = crate::menus::invoke(app, ctx, "comp.open", json!({"comp": cid}))
             {
                 app.ui.status = e;
             }
@@ -471,23 +463,37 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             lines.push(f.codec.clone());
         }
         for (i, l) in lines.iter().enumerate() {
-            let r = widgets::text_fit(&p, pos2(tx, thumb.min.y + 22.0 + 13.0 * i as f32), Align2::LEFT_CENTER, l, Tokens::ui(11.0), max_w, t.text_dim);
+            let r = widgets::text_fit(p, pos2(tx, thumb.min.y + 22.0 + 13.0 * i as f32), Align2::LEFT_CENTER, l, Tokens::ui(11.0), max_w, t.text_dim);
             app.auto.add(&format!("project.details.{i}"), r, l);
         }
     } else {
         let hint = "Select an item to see its details";
-        let r = widgets::text_fit(&p, head.center(), Align2::CENTER_CENTER, crate::i18n::tr(hint), Tokens::ui(11.0), head.width() - 20.0, t.text_faint);
+        let r = widgets::text_fit(p, head.center(), Align2::CENTER_CENTER, crate::i18n::tr(hint), Tokens::ui(11.0), head.width() - 20.0, t.text_faint);
         app.auto.add("project.details.hint", r, hint);
     }
-    // Search.
-    let sr = Rect::from_min_size(pos2(rect.min.x + 8.0, head.max.y + 2.0), vec2(rect.width() - 16.0, 22.0));
-    let mut q = app.ui.project_search.clone();
-    widgets::search_field(ui, sr, &mut q, crate::i18n::tr("Search project"), &t);
-    app.ui.project_search = q;
-    app.auto.add("project.search", sr, "Search");
-    // Column header: Name, Label, then the visible optional columns.
-    let hdr = Rect::from_min_size(pos2(rect.min.x, sr.max.y + 6.0), vec2(rect.width(), 20.0));
-    p.line_segment([hdr.left_bottom(), hdr.right_bottom()], Stroke::new(1.0, t.separator));
+}
+
+/// Column positions: Name and Label, then the visible optional columns (scrolled by `hscroll`).
+struct Columns {
+    cols: Vec<(&'static str, &'static str, f32, f32)>,
+    name_w: f32,
+    label_x: f32,
+    opt_x0: f32,
+    /// How far the optional columns overflow the panel.
+    overflow: f32,
+    hscroll: f32,
+    /// Where the last column ends.
+    end_x: f32,
+}
+
+impl Columns {
+    /// `r` cut off under the frozen Name and Label columns.
+    fn opt_clip(&self, r: Rect) -> Rect {
+        Rect::from_min_max(pos2(r.min.x.max(self.opt_x0 - 4.0), r.min.y), r.max)
+    }
+}
+
+fn layout_columns(app: &mut EffectcraftApp, rect: Rect) -> Columns {
     let name_w = (rect.width() * 0.40).clamp(120.0, 260.0);
     let label_x = rect.min.x + name_w + 14.0;
     let mut cols: Vec<(&'static str, &'static str, f32, f32)> = vec![("name", "Name", rect.min.x + 26.0, name_w - 26.0), ("label", "", label_x - 8.0, 18.0)];
@@ -505,11 +511,18 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             x += w + 4.0;
         }
     }
-    let opt_clip = |r: Rect| Rect::from_min_max(pos2(r.min.x.max(opt_x0 - 4.0), r.min.y), r.max);
+    Columns { cols, name_w, label_x, opt_x0, overflow, hscroll, end_x: x }
+}
+
+/// The column header row: sort labels with the sort arrow, and the Columns menu.
+fn draw_header(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, hdr: Rect, cl: &Columns) {
+    let t = app.tokens;
+    let Columns { cols, label_x, end_x, .. } = cl;
+    let (label_x, end_x) = (*label_x, *end_x);
     let hp = p.with_clip_rect(hdr);
-    for (key, label, x, w) in &cols {
+    for (key, label, x, w) in cols {
         let hr = Rect::from_min_size(pos2(x - 4.0, hdr.min.y), vec2(*w, hdr.height()));
-        let hr = if matches!(*key, "name" | "label") { hr } else { opt_clip(hr) };
+        let hr = if matches!(*key, "name" | "label") { hr } else { cl.opt_clip(hr) };
         if hr.width() <= 0.0 {
             continue;
         }
@@ -553,446 +566,202 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
         column_menu(app, &resp);
     }
-    let hresp = ui.interact(Rect::from_min_max(pos2(x, hdr.min.y), hdr.max), egui::Id::unique("proj-hdr-rest"), Sense::CLICK);
+    let hresp = ui.interact(Rect::from_min_max(pos2(end_x, hdr.min.y), hdr.max), egui::Id::unique("proj-hdr-rest"), Sense::CLICK);
     column_menu(app, &hresp);
     app.auto.add("project.columns", hdr, "Columns (right-click to show or hide)");
-    // Rows.
-    let footer_h = 28.0;
-    let list = Rect::from_min_max(pos2(rect.min.x, hdr.max.y), pos2(rect.max.x, rect.max.y - footer_h));
-    let lp = p.with_clip_rect(list);
-    // The list's empty area (under the rows and the scroll bar, which take their own clicks):
-    // a click deselects, a drag draws a selection box, a double-click imports, as in After
-    // Effects (File ▸ Import ▸ File...).
-    // Not a Tab stop: the keyboard reaches the rows, and nothing else here takes a key.
-    let empty = ui.interact(list, egui::Id::unique("proj-empty"), Sense::CLICK | Sense::DRAG);
-    app.auto.add("project.empty", list, "Double-click to import files; drag to select items; right-click for project actions");
-    if overflow > 0.0 && ui.rect_contains_pointer(list) {
-        let (dx, dy, shift) = ui.input(|i| (i.smooth_scroll_delta.x, i.smooth_scroll_delta.y, i.modifiers.shift));
-        let d = if dx.abs() > 0.0 {
-            dx
-        } else if shift {
-            dy
-        } else {
-            0.0
-        };
-        app.ui.project_hscroll = (app.ui.project_hscroll - d).clamp(0.0, overflow);
+}
+
+/// An item row's context menu: Composition Settings, Delete, Rename, Duplicate, labels and the
+/// footage commands.
+fn item_menu(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    ctx: &egui::Context,
+    it: &effectcraft_engine::project::Item,
+    id: ItemId,
+    selected: bool,
+    actions: &mut Vec<(String, serde_json::Value)>,
+) {
+    let t = app.tokens;
+    let footage = matches!(it.kind, ItemKind::Footage(_));
+    // First on a comp, as in After Effects; for this comp, not the viewer's (#1058).
+    if matches!(it.kind, ItemKind::Comp(_)) && ui.button(crate::i18n::tr("Composition Settings…")).clicked() {
+        actions.push(("comp.settings".into(), json!({"comp": id.0})));
+        ui.close();
     }
-    let moved = keyboard_nav(app, &ctx);
-    let rows = visible_rows(app);
-    // Enter renames the selected item (Project panel focused, not typing).
-    if app.ui.focused == crate::dock::PanelKind::Project
-        && app.dialog.is_none()
-        && keys_reach_rows(app, &ctx)
-        && ctx.data(|d| d.get_temp::<Editing>(edit_id())).is_none()
-        && ctx.input(|i| i.key_pressed(egui::Key::Enter))
-    {
-        begin_rename(app, &ctx);
+    if ui.button(crate::i18n::tr("Delete")).clicked() {
+        actions.push(("project.delete".into(), json!({"items": targets(app, id, selected)})));
+        ui.close();
     }
-    let editing: Option<Editing> = ctx.data(|d| d.get_temp(edit_id()));
-    let dragging = egui::DragAndDrop::payload::<DragPayload>(&ctx).and_then(|p| match *p {
-        DragPayload::Item(i) => Some(i),
-        _ => None,
+    if matches!(it.kind, ItemKind::Comp(_)) && ui.button(crate::i18n::tr("Open Composition")).clicked() {
+        actions.push(("comp.open".into(), json!({"comp": id.0})));
+        ui.close();
+    }
+    if ui.button(crate::i18n::tr("Rename")).clicked() {
+        ctx.data_mut(|d| d.insert_temp::<Editing>(edit_id(), (id.0, "name".into(), it.name.clone())));
+        ui.close();
+    }
+    let duplicate_items = targets(app, id, selected);
+    // Like Edit > Duplicate: folders disable the whole operation, including mixed selections.
+    let can_duplicate = !duplicate_items.is_empty() && duplicate_items.iter().all(|id| app.session.project.item(ItemId(*id)).is_some_and(|i| !i.is_folder()));
+    let mut duplicate = egui::Button::new(crate::i18n::tr("Duplicate"));
+    if let Some(shortcut) = app.session.shortcuts().shortcut_of("edit.duplicate", &serde_json::Value::Null) {
+        duplicate = duplicate.shortcut_text(crate::menus::shortcut_text(shortcut));
+    }
+    let response = ui.add_enabled(can_duplicate, duplicate);
+    app.auto.add("project.context.duplicate", response.rect, "Duplicate");
+    if response.clicked() {
+        actions.push(("project.duplicate".into(), json!({"items": duplicate_items})));
+        ui.close();
+    }
+    if it.parent.is_some() && ui.button(crate::i18n::tr("Move to Project Root")).clicked() {
+        actions.push(("project.move".into(), json!({"items": targets(app, id, selected), "folder": null})));
+        ui.close();
+    }
+    if !it.is_folder() && ui.button(crate::i18n::tr("Add to Composition")).clicked() {
+        actions.push(("layer.addItem".into(), json!({"item": id.0})));
+        ui.close();
+    }
+    // File ▸ New Comp from Selection on the selection (the right-clicked row joins it
+    // above): several items ask how in its dialog, as in After Effects (#360).
+    if ui.button(crate::i18n::tr("New Comp from Selection")).clicked() {
+        actions.push(("file.newCompFromSelection".into(), json!({})));
+        ui.close();
+    }
+    // File ▸ Replace Footage ▸ With Precomposition: every layer using the item uses a
+    // new composition holding it instead. The label says how many layers that changes.
+    let uses: usize = app.session.project.item_users(id).iter().map(|(_, n)| n).sum();
+    let label = match uses {
+        0 => crate::i18n::tr("Replace with Precomposition").to_owned(),
+        1 => format!("{} ({})", crate::i18n::tr("Replace with Precomposition"), crate::i18n::tr("used once")),
+        n => format!("{} ({})", crate::i18n::tr("Replace with Precomposition"), crate::i18n::tr_args("used {} times", &[&n])),
+    };
+    if (footage || matches!(it.kind, ItemKind::Solid(_))) && ui.button(label).clicked() {
+        actions.push(("file.replaceWithPrecomp".into(), json!({"item": id.0})));
+        ui.close();
+    }
+    ui.separator();
+    ui.menu_button(crate::i18n::tr("Label"), |ui| {
+        for l in Label::ALL {
+            if widgets::label_entry(ui, l, &app.session.prefs.label_name(l), l == it.label, &t).clicked() {
+                actions.push(("project.setLabel".into(), json!({"items": targets(app, id, selected), "label": label_index(l)})));
+                ui.close();
+            }
+        }
     });
-    let hover_y = ctx.pointer_hover_pos().filter(|p| list.contains(*p)).map(|p| p.y);
-    let mut drop_row: Option<ItemId> = None;
-    let mut actions: Vec<(String, serde_json::Value)> = vec![];
-    // Vertical scrolling: only the rows in view are drawn (and registered), so a project with
-    // thousands of items costs what one screenful does.
-    let content_h = rows.len() as f32 * ROW_H;
-    let max_scroll = (content_h - list.height() + ROW_H).max(0.0);
-    if ui.rect_contains_pointer(list) {
-        let (dy, shift) = ui.input(|i| (i.smooth_scroll_delta.y, i.modifiers.shift));
-        if !shift && dy != 0.0 {
-            app.ui.project_scroll -= dy;
-        }
+    // Footage: the File menu's footage commands (Interpret Footage, Replace Footage…).
+    if footage {
+        let mut chosen = None;
+        crate::menus::submenu_at(app, ui, &["File", "Interpret Footage"], &mut chosen);
+        crate::menus::submenu_at(app, ui, &["File", "Replace Footage"], &mut chosen);
+        crate::menus::entry_for(app, ui, "file.reloadFootage", &mut chosen);
+        crate::menus::entry_for(app, ui, "file.revealInFinder", &mut chosen);
+        actions.extend(chosen);
     }
-    // A selection made elsewhere (a command, an agent, the viewer) scrolls into view.
-    let sel_key = selection_seen_id();
-    let sel_now = app.session.state.project_selection.last().map(|i| i.0);
-    if ctx.data(|d| d.get_temp::<Option<u64>>(sel_key)) != Some(sel_now) {
-        ctx.data_mut(|d| d.insert_temp(sel_key, sel_now));
-        if let Some(row) = sel_now.and_then(|s| rows.iter().position(|(id, _)| id.0 == s)) {
-            let top = row as f32 * ROW_H;
-            if top < app.ui.project_scroll {
-                app.ui.project_scroll = top;
-            } else if top + ROW_H > app.ui.project_scroll + list.height() {
-                app.ui.project_scroll = top + ROW_H - list.height();
-            }
-        }
+}
+
+/// The inline rename / comment field over `cell` when it is item `id`'s `field` being edited;
+/// returns whether it took the cell.
+fn cell_edit(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    actions: &mut Vec<(String, serde_json::Value)>,
+    editing: &Option<Editing>,
+    id: u64,
+    field: &str,
+    cell: Rect,
+) -> bool {
+    let ctx = ui.ctx().clone();
+    let Some((eid, ef, mut buf)) = editing.clone().filter(|(e, f, _)| *e == id && f == field) else { return false };
+    let mut child = ui.new_child(egui::UiBuilder::new().max_rect(cell));
+    // The field keeps Tab (egui would move the keyboard to the next widget, where Enter no
+    // longer renames, #881): Tab commits like Enter and gives the keyboard back to the panel.
+    let filter = egui::EventFilter { tab: true, horizontal_arrows: true, vertical_arrows: true, ..Default::default() };
+    let resp = child.add(egui::TextEdit::singleline(&mut buf).desired_width(cell.width()).font(Tokens::ui(12.0)).event_filter(filter));
+    app.auto.add(&format!("project.item.{}.{field}Edit", id), cell, field);
+    let tab = resp.has_focus() && ctx.input(|i| i.key_pressed(egui::Key::Tab));
+    if tab {
+        resp.surrender_focus();
     }
-    // The arrow keys' item scrolls into view (Shift+Up extends upward, past the selection's end).
-    if let Some(row) = moved.and_then(|m| rows.iter().position(|(id, _)| *id == m)) {
-        let top = row as f32 * ROW_H;
-        // Not `clamp`: a panel shorter than a row would make its bounds cross. The row's top wins.
-        app.ui.project_scroll = app.ui.project_scroll.max(top + ROW_H - list.height()).min(top);
-    }
-    app.ui.project_scroll = app.ui.project_scroll.clamp(0.0, max_scroll);
-    let scroll = app.ui.project_scroll;
-    let first = ((scroll / ROW_H).floor() as usize).min(rows.len());
-    let mut y = list.min.y - (scroll - first as f32 * ROW_H);
-    let project = app.session.project.clone();
-    for (i, (id, depth)) in rows.iter().enumerate().skip(first) {
-        let Some(it) = project.item(*id) else { continue };
-        let r = Rect::from_min_size(pos2(list.min.x, y), vec2(list.width(), ROW_H));
-        y += ROW_H;
-        if r.min.y > list.max.y {
-            break;
-        }
-        if hover_y.is_some_and(|hy| hy >= r.min.y && hy < r.max.y) {
-            drop_row = Some(*id);
-        }
-        let selected = app.session.state.project_selection.contains(id);
-        lp.rect_filled(
-            r,
-            0.0,
-            // Flat rows like After Effects' Project panel (no stripes).
-            if selected { t.row_selected } else { t.row },
-        );
-        // The row's click / drag area goes first, so the twirl, proxy, label and comment widgets
-        // on top of it take their own clicks.
-        let mut resp = ui.interact(r.intersect(list), row_id(*id), Sense::click_and_drag());
-        app.auto.add(&format!("project.item.{}", id.0), r, &it.name);
-        // For screen readers: a tree item named by the item and its type, with its selection,
-        // depth and (a folder) open state. One Tab stop per row; the panel's keys then apply.
-        let open = it.is_folder().then(|| app.ui.project_open_folders.contains(&id.0) || !app.ui.project_search.is_empty());
-        resp.widget_info(|| egui::WidgetInfo::labeled(egui::Role::TreeItem, true, format!("{}, {}", it.name, crate::i18n::tr(it.type_name()))));
-        ctx.accesskit_node_builder(resp.id, |n| {
-            n.set_selected(selected);
-            n.set_level(depth.saturating_add(1));
-            if let Some(open) = open {
-                n.set_expanded(open);
-            }
-        });
-        if resp.has_focus() {
-            ctx.data_mut(|d| d.insert_temp(focused_row_id(), *id));
-        }
-        if resp.gained_focus() {
-            app.ui.focused = crate::dock::PanelKind::Project;
-        }
-        let _ = i;
-        let x0 = r.min.x + 8.0 + 14.0 * *depth as f32;
-        if it.is_folder() {
-            let open = app.ui.project_open_folders.contains(&id.0);
-            let tw = Rect::from_center_size(pos2(x0 + 4.0, r.center().y), vec2(12.0, 12.0));
-            let tresp = widgets::twirl(ui, tw, open, egui::Id::unique(("pf", id.0)), &t);
-            tresp.widget_info(|| {
-                let name = crate::i18n::tr_args(if open { "Close folder {}" } else { "Open folder {}" }, &[&it.name]);
-                egui::WidgetInfo::labeled(egui::Role::Button, true, name)
-            });
-            if tresp.clicked() {
-                // Alt/Cmd-click twirls every folder inside it too.
-                let mut ids = vec![*id];
-                if ui.input(|i| i.modifiers.alt || i.modifiers.command) {
-                    let mut at = 0;
-                    while let Some(f) = ids.get(at).copied() {
-                        ids.extend(app.session.project.children(Some(f)).into_iter().filter(|c| c.is_folder()).map(|c| c.id));
-                        at += 1;
-                    }
-                }
-                for f in ids {
-                    if open {
-                        app.ui.project_open_folders.remove(&f.0);
-                    } else {
-                        app.ui.project_open_folders.insert(f.0);
-                    }
-                }
-            }
-            app.auto.add(&format!("project.item.{}.twirl", id.0), tw, &it.name);
-        }
-        icons::paint(&lp, Rect::from_center_size(pos2(x0 + 18.0, r.center().y), vec2(14.0, 14.0)), item_icon(it), t.text_dim);
-        // Proxy indicator: filled = the proxy is used, hollow = set but off. Click to switch.
-        if let Some(px) = it.proxy.as_ref() {
-            let pr = Rect::from_center_size(pos2(x0 + 4.0, r.center().y), vec2(9.0, 9.0));
-            if px.enabled {
-                lp.rect_filled(pr, 1.0, t.text);
+    if resp.lost_focus() || tab {
+        ctx.data_mut(|d| d.remove::<Editing>(edit_id()));
+        if !ctx.input(|i| i.key_pressed(egui::Key::Escape)) {
+            let (cmd, params) = if ef == "name" {
+                ("project.rename", json!({"item": eid, "name": buf}))
             } else {
-                lp.rect_stroke(pr, 1.0, Stroke::new(1.0, t.text), egui::StrokeKind::Inside);
-            }
-            let presp = ui.interact(pr.expand(2.0).intersect(list), egui::Id::unique(("pproxy", id.0)), Sense::click()).on_hover_text(format!(
-                "Proxy: {} ({})",
-                px.footage.path,
-                if px.enabled { "in use" } else { "off" }
-            ));
-            app.auto.add(&format!("project.item.{}.proxy", id.0), pr, if px.enabled { "Proxy in use" } else { "Proxy off" });
-            presp.widget_info(|| {
-                let name = crate::i18n::tr_args(if px.enabled { "Proxy of {}: in use" } else { "Proxy of {}: off" }, &[&it.name]);
-                egui::WidgetInfo::labeled(egui::Role::Button, true, name)
-            });
-            if presp.clicked() {
-                actions.push(("file.useProxy".into(), json!({"item": id.0})));
-            }
-        }
-        // Footage that can't be decoded (no decoder for its codec / profile): a warning marker
-        // at the end of the name cell, the reason on hover.
-        let problem = match &it.kind {
-            ItemKind::Footage(f) => app.session.footage.problem(f),
-            _ => None,
-        };
-        let name_clip =
-            Rect::from_min_max(pos2(x0 + 30.0, r.min.y), pos2(r.min.x + name_w + 4.0 - if problem.is_some() { 16.0 } else { 0.0 }, r.max.y)).intersect(list);
-        if let Some(why) = &problem {
-            let m = Rect::from_center_size(pos2(r.min.x + name_w - 8.0, r.center().y), vec2(13.0, 12.0));
-            lp.add(egui::Shape::convex_polygon(vec![m.center_top(), m.right_bottom(), m.left_bottom()], t.warning, Stroke::NONE));
-            lp.text(m.center() + vec2(0.0, 1.5), Align2::CENTER_CENTER, "!", Tokens::semibold(9.0), Color32::BLACK);
-            ui.interact(m.expand(2.0).intersect(list), egui::Id::unique(("pproblem", id.0)), Sense::hover()).on_hover_text(why.as_str());
-            app.auto.add(&format!("project.item.{}.problem", id.0), m, why);
-        }
-        let name_rect = Rect::from_min_max(pos2(x0 + 28.0, r.min.y + 2.0), pos2(r.min.x + name_w + 2.0, r.max.y - 2.0));
-        // Inline edits (rename / comment).
-        let cell_edit = |app: &mut EffectcraftApp, ui: &mut egui::Ui, actions: &mut Vec<(String, serde_json::Value)>, field: &str, cell: Rect| -> bool {
-            let Some((eid, ef, mut buf)) = editing.clone().filter(|(e, f, _)| *e == id.0 && f == field) else { return false };
-            let mut child = ui.new_child(egui::UiBuilder::new().max_rect(cell));
-            // The field keeps Tab (egui would move the keyboard to the next widget, where Enter no
-            // longer renames, #881): Tab commits like Enter and gives the keyboard back to the panel.
-            let filter = egui::EventFilter { tab: true, horizontal_arrows: true, vertical_arrows: true, ..Default::default() };
-            let resp = child.add(egui::TextEdit::singleline(&mut buf).desired_width(cell.width()).font(Tokens::ui(12.0)).event_filter(filter));
-            app.auto.add(&format!("project.item.{}.{field}Edit", id.0), cell, field);
-            let tab = resp.has_focus() && ctx.input(|i| i.key_pressed(egui::Key::Tab));
-            if tab {
-                resp.surrender_focus();
-            }
-            if resp.lost_focus() || tab {
-                ctx.data_mut(|d| d.remove::<Editing>(edit_id()));
-                if !ctx.input(|i| i.key_pressed(egui::Key::Escape)) {
-                    let (cmd, params) = if ef == "name" {
-                        ("project.rename", json!({"item": eid, "name": buf}))
-                    } else {
-                        ("project.setComment", json!({"items": [eid], "comment": buf}))
-                    };
-                    actions.push((cmd.into(), params));
-                }
-            } else {
-                widgets::keep_focus(&ctx, &resp, &buf);
-                ctx.data_mut(|d| d.insert_temp::<Editing>(edit_id(), (eid, ef, buf)));
-            }
-            true
-        };
-        if !cell_edit(app, ui, &mut actions, "name", name_rect) {
-            // The selected item's name sits in a light cell with dark text.
-            if selected {
-                let g = lp.layout_no_wrap(it.name.clone(), Tokens::ui(12.0), Color32::BLACK);
-                let cell = Rect::from_min_max(pos2(x0 + 27.0, r.min.y + 1.0), pos2((x0 + 33.0 + g.size().x).min(name_clip.max.x), r.max.y - 1.0));
-                lp.with_clip_rect(name_clip.expand2(vec2(3.0, 0.0))).rect_filled(cell, 0.0, Color32::from_rgb(0xa6, 0xa6, 0xa6));
-            }
-            // Long names end in "…" before the label column instead of being cut mid-glyph.
-            widgets::text_fit(
-                &lp.with_clip_rect(name_clip),
-                pos2(x0 + 30.0, r.center().y),
-                Align2::LEFT_CENTER,
-                &it.name,
-                Tokens::ui(12.0),
-                name_clip.max.x - (x0 + 30.0) - 2.0,
-                if selected { Color32::from_gray(0x16) } else { t.text },
-            );
-        }
-        // Label swatch: click for the label colour menu.
-        let sw = Rect::from_center_size(pos2(label_x, r.center().y), vec2(10.0, 10.0));
-        lp.rect_filled(sw, 2.0, t.label(it.label));
-        let sresp = ui.interact(sw.expand(3.0).intersect(list), egui::Id::unique(("plabel", id.0)), Sense::click());
-        app.auto.add(&format!("project.item.{}.label", id.0), sw, it.label.name());
-        sresp.widget_info(|| {
-            let name = crate::i18n::tr_args("Label of {}: {}", &[&it.name, &app.session.prefs.label_name(it.label)]);
-            egui::WidgetInfo::labeled(egui::Role::Button, true, name)
-        });
-        let pop = egui::Id::unique(("plabel-pop", id.0));
-        if sresp.clicked() || sresp.secondary_clicked() {
-            widgets::open_popup(ui, pop);
-        }
-        if let Some(l) = widgets::label_popup(ui, pop, sw.left_bottom(), it.label, |l| app.session.prefs.label_name(l), &t) {
-            actions.push(("project.setLabel".into(), json!({"items": targets(app, *id, selected), "label": label_index(l)})));
-        }
-        // Optional columns.
-        for (key, _, cx, w) in cols.iter().skip(2) {
-            let cell = opt_clip(Rect::from_min_size(pos2(*cx, r.min.y), vec2(*w, r.height())).intersect(list));
-            if cell.width() <= 0.0 {
-                continue;
-            }
-            let cp = lp.with_clip_rect(cell);
-            let txt = match *key {
-                "type" => it.type_name().to_string(),
-                "size" => file_size(it).map(fmt_size).unwrap_or_default(),
-                "duration" => it.duration().map(|d| fmt_dur(d.seconds(), it.frame_rate().map(|r| r.as_f64()).unwrap_or(30.0))).unwrap_or_default(),
-                "fps" => it.frame_rate().map(|f| format!("{:.2}", f.as_f64())).unwrap_or_default(),
-                "path" => file_path(it).to_string(),
-                "comment" => {
-                    let cr = Rect::from_min_size(pos2(*cx - 2.0, r.min.y + 2.0), vec2(*w, r.height() - 4.0));
-                    if cell_edit(app, ui, &mut actions, "comment", cr) {
-                        continue;
-                    }
-                    let cresp = ui.interact(cell, egui::Id::unique(("pcomment", id.0)), Sense::CLICK);
-                    app.auto.add(&format!("project.item.{}.comment", id.0), cell, &it.comment);
-                    cresp.widget_info(|| {
-                        egui::WidgetInfo::labeled(egui::Role::Unknown, true, crate::i18n::tr_args("Comment of {}: {}", &[&it.name, &it.comment]))
-                    });
-                    if cresp.double_clicked() {
-                        ctx.data_mut(|d| d.insert_temp::<Editing>(edit_id(), (id.0, "comment".into(), it.comment.clone())));
-                    } else {
-                        // Other clicks select the row and open its context menu.
-                        resp = resp.union(cresp);
-                    }
-                    it.comment.clone()
-                }
-                _ => String::new(),
+                ("project.setComment", json!({"items": [eid], "comment": buf}))
             };
-            let align = if *key == "fps" { Align2::RIGHT_CENTER } else { Align2::LEFT_CENTER };
-            let tx = if *key == "fps" { cx + w - 6.0 } else { *cx };
-            cp.text(pos2(tx, r.center().y), align, txt, Tokens::ui(11.5), t.text_dim);
+            actions.push((cmd.into(), params));
         }
-        if dragging.is_some_and(|d| d != id.0) && drop_row == Some(*id) && it.is_folder() {
-            lp.rect_stroke(r.shrink(1.0), 2.0, Stroke::new(1.5, t.accent), egui::StrokeKind::Inside);
-        }
-        // The row with keyboard focus (Tab, or the arrow keys after it) shows a focus ring.
-        if ctx.memory(|m| m.has_focus(row_id(*id))) {
-            lp.rect_stroke(r.shrink(0.5), 0.0, Stroke::new(1.0, t.accent), egui::StrokeKind::Inside);
-        }
-        // Part of the row: not a second Tab stop.
-        let nresp = ui.interact(name_clip, egui::Id::unique(("pname", id.0)), Sense::CLICK | Sense::DRAG);
-        app.auto.add(&format!("project.item.{}.name", id.0), name_clip, &it.name);
-        let resp = resp.union(nresp);
-        if resp.clicked() {
-            let m = ui.input(|i| i.modifiers);
-            let anchor_key = anchor_id();
-            ctx.data_mut(|d| d.insert_temp(cursor_id(), *id));
-            let anchor = ctx.data(|d| d.get_temp::<ItemId>(anchor_key)).or_else(|| app.session.state.project_selection.first().copied());
-            if m.shift
-                && let Some(a) = anchor.and_then(|a| rows.iter().position(|(i, _)| *i == a))
-            {
-                let b = rows.iter().position(|(i, _)| i == id).unwrap_or(a);
-                app.session.state.project_selection = rows.get(a.min(b)..=a.max(b)).unwrap_or_default().iter().map(|(i, _)| *i).collect();
-            } else if m.command {
-                if app.session.state.project_selection.contains(id) {
-                    app.session.state.project_selection.retain(|i| i != id);
-                } else {
-                    app.session.state.project_selection.push(*id);
-                }
-                ctx.data_mut(|d| d.insert_temp(anchor_key, *id));
-            } else {
-                app.session.state.project_selection = vec![*id];
-                ctx.data_mut(|d| d.insert_temp(anchor_key, *id));
-            }
-        }
-        // Double-click opens the item, as in After Effects (a comp gets its own Timeline tab and
-        // the viewer); Enter or the context menu renames.
-        if resp.double_clicked() {
-            match &it.kind {
-                ItemKind::Comp(_) => actions.push(("comp.open".into(), json!({"comp": id.0}))),
-                ItemKind::Folder if !app.ui.project_open_folders.remove(&id.0) => {
-                    app.ui.project_open_folders.insert(id.0);
-                }
-                // Footage (not data) and solids open in the Footage panel.
-                ItemKind::Footage(f) if f.kind != effectcraft_engine::project::FootageKind::Data => {
-                    actions.push(("footage.open".into(), json!({"item": id.0})))
-                }
-                ItemKind::Solid(_) => actions.push(("footage.open".into(), json!({"item": id.0}))),
-                _ => {}
-            }
-        }
-        if resp.drag_started() {
-            egui::DragAndDrop::set_payload(&ctx, DragPayload::Item(id.0));
-        }
-        // Right-clicking an item selects it (After Effects): the menu's File commands act on the
-        // selection.
-        if resp.secondary_clicked() && !selected {
-            app.session.state.project_selection = vec![*id];
-        }
-        let footage = matches!(it.kind, ItemKind::Footage(_));
-        crate::widgets::context_menu(&resp, |ui| {
-            // First on a comp, as in After Effects; for this comp, not the viewer's (#1058).
-            if matches!(it.kind, ItemKind::Comp(_)) && ui.button(crate::i18n::tr("Composition Settings…")).clicked() {
-                actions.push(("comp.settings".into(), json!({"comp": id.0})));
-                ui.close();
-            }
-            if ui.button(crate::i18n::tr("Delete")).clicked() {
-                actions.push(("project.delete".into(), json!({"items": targets(app, *id, selected)})));
-                ui.close();
-            }
-            if matches!(it.kind, ItemKind::Comp(_)) && ui.button(crate::i18n::tr("Open Composition")).clicked() {
-                actions.push(("comp.open".into(), json!({"comp": id.0})));
-                ui.close();
-            }
-            if ui.button(crate::i18n::tr("Rename")).clicked() {
-                ctx.data_mut(|d| d.insert_temp::<Editing>(edit_id(), (id.0, "name".into(), it.name.clone())));
-                ui.close();
-            }
-            let duplicate_items = targets(app, *id, selected);
-            // Like Edit > Duplicate: folders disable the whole operation, including mixed selections.
-            let can_duplicate =
-                !duplicate_items.is_empty() && duplicate_items.iter().all(|id| app.session.project.item(ItemId(*id)).is_some_and(|i| !i.is_folder()));
-            let mut duplicate = egui::Button::new(crate::i18n::tr("Duplicate"));
-            if let Some(shortcut) = app.session.shortcuts().shortcut_of("edit.duplicate", &serde_json::Value::Null) {
-                duplicate = duplicate.shortcut_text(crate::menus::shortcut_text(shortcut));
-            }
-            let response = ui.add_enabled(can_duplicate, duplicate);
-            app.auto.add("project.context.duplicate", response.rect, "Duplicate");
-            if response.clicked() {
-                actions.push(("project.duplicate".into(), json!({"items": duplicate_items})));
-                ui.close();
-            }
-            if it.parent.is_some() && ui.button(crate::i18n::tr("Move to Project Root")).clicked() {
-                actions.push(("project.move".into(), json!({"items": targets(app, *id, selected), "folder": null})));
-                ui.close();
-            }
-            if !it.is_folder() && ui.button(crate::i18n::tr("Add to Composition")).clicked() {
-                actions.push(("layer.addItem".into(), json!({"item": id.0})));
-                ui.close();
-            }
-            // File ▸ New Comp from Selection on the selection (the right-clicked row joins it
-            // above): several items ask how in its dialog, as in After Effects (#360).
-            if ui.button(crate::i18n::tr("New Comp from Selection")).clicked() {
-                actions.push(("file.newCompFromSelection".into(), json!({})));
-                ui.close();
-            }
-            // File ▸ Replace Footage ▸ With Precomposition: every layer using the item uses a
-            // new composition holding it instead. The label says how many layers that changes.
-            let uses: usize = app.session.project.item_users(*id).iter().map(|(_, n)| n).sum();
-            let label = match uses {
-                0 => crate::i18n::tr("Replace with Precomposition").to_owned(),
-                1 => format!("{} ({})", crate::i18n::tr("Replace with Precomposition"), crate::i18n::tr("used once")),
-                n => format!("{} ({})", crate::i18n::tr("Replace with Precomposition"), crate::i18n::tr_args("used {} times", &[&n])),
-            };
-            if (footage || matches!(it.kind, ItemKind::Solid(_))) && ui.button(label).clicked() {
-                actions.push(("file.replaceWithPrecomp".into(), json!({"item": id.0})));
-                ui.close();
-            }
-            ui.separator();
-            ui.menu_button(crate::i18n::tr("Label"), |ui| {
-                for l in Label::ALL {
-                    if widgets::label_entry(ui, l, &app.session.prefs.label_name(l), l == it.label, &t).clicked() {
-                        actions.push(("project.setLabel".into(), json!({"items": targets(app, *id, selected), "label": label_index(l)})));
-                        ui.close();
-                    }
-                }
-            });
-            // Footage: the File menu's footage commands (Interpret Footage, Replace Footage…).
-            if footage {
-                let mut chosen = None;
-                crate::menus::submenu_at(app, ui, &["File", "Interpret Footage"], &mut chosen);
-                crate::menus::submenu_at(app, ui, &["File", "Replace Footage"], &mut chosen);
-                crate::menus::entry_for(app, ui, "file.reloadFootage", &mut chosen);
-                crate::menus::entry_for(app, ui, "file.revealInFinder", &mut chosen);
-                actions.extend(chosen);
-            }
-        });
+    } else {
+        widgets::keep_focus(&ctx, &resp, &buf);
+        ctx.data_mut(|d| d.insert_temp::<Editing>(edit_id(), (eid, ef, buf)));
     }
-    // The scroll bars, over the rows (which would take their presses otherwise).
-    if overflow > 0.0 {
-        let track = Rect::from_min_max(pos2(opt_x0, list.max.y - 5.0), pos2(rect.max.x - 4.0, list.max.y - 1.0));
-        app.ui.project_hscroll = widgets::scroll_bar(ui, &mut app.auto, "project.hscroll", track, hscroll, overflow, &t);
+    true
+}
+
+/// A click on item `id`'s row: plain selects it, Shift extends from the anchor and Cmd toggles.
+fn select_click(app: &mut EffectcraftApp, ui: &egui::Ui, ctx: &egui::Context, id: ItemId, rows: &[(ItemId, usize)]) {
+    let m = ui.input(|i| i.modifiers);
+    let anchor_key = anchor_id();
+    ctx.data_mut(|d| d.insert_temp(cursor_id(), id));
+    let anchor = ctx.data(|d| d.get_temp::<ItemId>(anchor_key)).or_else(|| app.session.state.project_selection.first().copied());
+    if m.shift
+        && let Some(a) = anchor.and_then(|a| rows.iter().position(|(i, _)| *i == a))
+    {
+        let b = rows.iter().position(|(i, _)| *i == id).unwrap_or(a);
+        app.session.state.project_selection = rows.get(a.min(b)..=a.max(b)).unwrap_or_default().iter().map(|(i, _)| *i).collect();
+    } else if m.command {
+        if app.session.state.project_selection.contains(&id) {
+            app.session.state.project_selection.retain(|i| *i != id);
+        } else {
+            app.session.state.project_selection.push(id);
+        }
+        ctx.data_mut(|d| d.insert_temp(anchor_key, id));
+    } else {
+        app.session.state.project_selection = vec![id];
+        ctx.data_mut(|d| d.insert_temp(anchor_key, id));
     }
-    if max_scroll > 0.0 {
-        let track = Rect::from_min_max(pos2(rect.max.x - 6.0, list.min.y + 1.0), pos2(rect.max.x - 2.0, list.max.y - 7.0));
-        app.ui.project_scroll = widgets::scroll_bar(ui, &mut app.auto, "project.vscroll", track, scroll, max_scroll, &t);
+}
+
+/// Double-click opens the item, as in After Effects: a comp in its Timeline and the viewer, a
+/// folder toggles, footage (not data) and solids open in the Footage panel.
+fn open_item(app: &mut EffectcraftApp, it: &effectcraft_engine::project::Item, id: ItemId, actions: &mut Vec<(String, serde_json::Value)>) {
+    match &it.kind {
+        ItemKind::Comp(_) => actions.push(("comp.open".into(), json!({"comp": id.0}))),
+        ItemKind::Folder if !app.ui.project_open_folders.remove(&id.0) => {
+            app.ui.project_open_folders.insert(id.0);
+        }
+        // Footage (not data) and solids open in the Footage panel.
+        ItemKind::Footage(f) if f.kind != effectcraft_engine::project::FootageKind::Data => actions.push(("footage.open".into(), json!({"item": id.0}))),
+        ItemKind::Solid(_) => actions.push(("footage.open".into(), json!({"item": id.0}))),
+        _ => {}
     }
+}
+
+/// What the pointer is doing over the list: the item being dragged, the row under it, whether it
+/// is over the list at all.
+struct DropState {
+    dragging: Option<u64>,
+    row: Option<ItemId>,
+    hovering: bool,
+}
+
+/// Dragging an item or files over the list: drop outlines, moving items into folders, importing
+/// files and the drag ghost.
+fn drop_targets(app: &mut EffectcraftApp, ctx: &egui::Context, lp: &egui::Painter, list: Rect, ds: DropState, actions: &mut Vec<(String, serde_json::Value)>) {
+    let t = app.tokens;
+    let DropState { dragging, row, hovering } = ds;
     // Dropping a dragged item on the list: into the folder under the pointer (or the folder of
     // the item under it), or the project root below the rows.
     if let Some(iid) = dragging
-        && hover_y.is_some()
+        && hovering
     {
-        if drop_row.is_none() {
+        if row.is_none() {
             lp.rect_stroke(list.shrink(1.0), 0.0, Stroke::new(1.0, t.accent.gamma_multiply(0.6)), egui::StrokeKind::Inside);
         }
-        if ctx.input(|i| i.pointer.any_released()) && drop_row != Some(ItemId(iid)) {
-            let folder = drop_folder(&app.session.project, drop_row);
+        if ctx.input(|i| i.pointer.any_released()) && row != Some(ItemId(iid)) {
+            let folder = drop_folder(&app.session.project, row);
             let cur = app.session.project.item(ItemId(iid)).and_then(|i| i.parent);
             if folder != cur {
                 let moving: Vec<u64> = if app.session.state.project_selection.contains(&ItemId(iid)) {
@@ -1005,21 +774,21 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                     app.ui.project_open_folders.insert(f.0);
                 }
             }
-            egui::DragAndDrop::clear_payload(&ctx);
+            egui::DragAndDrop::clear_payload(ctx);
         }
     }
     // Files dragged from the Media Browser: import.
-    if let Some(DragPayload::Files(paths)) = egui::DragAndDrop::payload::<DragPayload>(&ctx).as_deref()
-        && hover_y.is_some()
+    if let Some(DragPayload::Files(paths)) = egui::DragAndDrop::payload::<DragPayload>(ctx).as_deref()
+        && hovering
     {
         lp.rect_stroke(list.shrink(1.0), 0.0, Stroke::new(1.0, t.accent.gamma_multiply(0.6)), egui::StrokeKind::Inside);
         if ctx.input(|i| i.pointer.any_released()) {
             actions.push(("mediaBrowser.import".into(), json!({"paths": paths})));
-            egui::DragAndDrop::clear_payload(&ctx);
+            egui::DragAndDrop::clear_payload(ctx);
         }
     }
     // Drag ghost.
-    if let Some(DragPayload::Item(iid)) = egui::DragAndDrop::payload::<DragPayload>(&ctx).as_deref()
+    if let Some(DragPayload::Item(iid)) = egui::DragAndDrop::payload::<DragPayload>(ctx).as_deref()
         && let Some(pos) = ctx.pointer_hover_pos()
         && let Some(it) = app.session.project.item(ItemId(*iid))
     {
@@ -1029,8 +798,12 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         painter.rect_filled(r, 4.0, Color32::from_rgba_premultiplied(40, 40, 40, 230));
         painter.galley(r.min + vec2(8.0, 4.0), g, t.text);
     }
-    // Footer.
-    let foot = Rect::from_min_max(pos2(rect.min.x, rect.max.y - footer_h), rect.max);
+}
+
+/// The footer: Interpret Footage, New Folder, New Composition, the colour depth and the trash.
+fn footer(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, foot: Rect, actions: &mut Vec<(String, serde_json::Value)>) {
+    let t = app.tokens;
+    let ctx = ui.ctx().clone();
     p.line_segment([foot.left_top(), foot.right_top()], Stroke::new(1.0, t.separator));
     let mut x = foot.min.x + 8.0;
     for (icon, id, tip) in [
@@ -1092,23 +865,102 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         actions.push(("project.delete".into(), json!({})));
     }
     app.auto.add("project.delete", tr, "Delete");
-    if empty.double_clicked() {
-        actions.push(("file.import".into(), json!({})));
-    }
-    crate::widgets::context_menu(&empty, |ui| {
-        for (key, label, command) in
-            [("newComp", "New Composition…", "comp.new"), ("newFolder", "New Folder", "project.newFolder"), ("import", "Import File…", "file.import")]
-        {
-            let response = ui.button(label);
-            app.auto.add(&format!("project.context.{key}"), response.rect, label);
-            if response.clicked() {
-                actions.push((command.into(), json!({})));
-                ui.close();
-            }
+}
+
+/// The optional columns of a row (type, size, duration, fps, path, comment). Returns the comment
+/// cell's response so its clicks select the row and open its context menu.
+fn optional_cells(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    g: &RowGeom,
+    it: &effectcraft_engine::project::Item,
+    cl: &Columns,
+    editing: &Option<Editing>,
+    actions: &mut Vec<(String, serde_json::Value)>,
+) -> Option<egui::Response> {
+    let t = app.tokens;
+    let ctx = ui.ctx().clone();
+    let RowGeom { lp, list, r, .. } = *g;
+    let mut extra = None;
+    for (key, _, cx, w) in cl.cols.iter().skip(2) {
+        let cell = cl.opt_clip(Rect::from_min_size(pos2(*cx, r.min.y), vec2(*w, r.height())).intersect(list));
+        if cell.width() <= 0.0 {
+            continue;
         }
-    });
-    // Selection box over the rows it touches (#203); Shift or Cmd/Ctrl adds to the selection.
-    let adding = ui.input(|i| i.modifiers.shift || i.modifiers.command);
+        let cp = lp.with_clip_rect(cell);
+        let txt = match *key {
+            "type" => it.type_name().to_string(),
+            "size" => file_size(it).map(fmt_size).unwrap_or_default(),
+            "duration" => it.duration().map(|d| fmt_dur(d.seconds(), it.frame_rate().map(|r| r.as_f64()).unwrap_or(30.0))).unwrap_or_default(),
+            "fps" => it.frame_rate().map(|f| format!("{:.2}", f.as_f64())).unwrap_or_default(),
+            "path" => file_path(it).to_string(),
+            "comment" => {
+                let cr = Rect::from_min_size(pos2(*cx - 2.0, r.min.y + 2.0), vec2(*w, r.height() - 4.0));
+                if cell_edit(app, ui, actions, editing, it.id.0, "comment", cr) {
+                    continue;
+                }
+                let cresp = ui.interact(cell, egui::Id::unique(("pcomment", it.id.0)), Sense::CLICK);
+                app.auto.add(&format!("project.item.{}.comment", it.id.0), cell, &it.comment);
+                cresp.widget_info(|| egui::WidgetInfo::labeled(egui::Role::Unknown, true, crate::i18n::tr_args("Comment of {}: {}", &[&it.name, &it.comment])));
+                if cresp.double_clicked() {
+                    ctx.data_mut(|d| d.insert_temp::<Editing>(edit_id(), (it.id.0, "comment".into(), it.comment.clone())));
+                } else {
+                    // Other clicks select the row and open its context menu.
+                    extra = Some(cresp);
+                }
+                it.comment.clone()
+            }
+            _ => String::new(),
+        };
+        let align = if *key == "fps" { Align2::RIGHT_CENTER } else { Align2::LEFT_CENTER };
+        let tx = if *key == "fps" { cx + w - 6.0 } else { *cx };
+        cp.text(pos2(tx, r.center().y), align, txt, Tokens::ui(11.5), t.text_dim);
+    }
+    extra
+}
+
+/// Shift+wheel / trackpad over the list scrolls the optional columns sideways.
+fn hscroll_wheel(app: &mut EffectcraftApp, ui: &egui::Ui, list: Rect, overflow: f32) {
+    if overflow > 0.0 && ui.rect_contains_pointer(list) {
+        let (dx, dy, shift) = ui.input(|i| (i.smooth_scroll_delta.x, i.smooth_scroll_delta.y, i.modifiers.shift));
+        let d = if dx.abs() > 0.0 {
+            dx
+        } else if shift {
+            dy
+        } else {
+            0.0
+        };
+        app.ui.project_hscroll = (app.ui.project_hscroll - d).clamp(0.0, overflow);
+    }
+}
+
+/// Enter renames the selected item (Project panel focused, not typing).
+fn enter_renames(app: &mut EffectcraftApp, ctx: &egui::Context) {
+    if app.ui.focused == crate::dock::PanelKind::Project
+        && app.dialog.is_none()
+        && keys_reach_rows(app, ctx)
+        && ctx.data(|d| d.get_temp::<Editing>(edit_id())).is_none()
+        && ctx.input(|i| i.key_pressed(egui::Key::Enter))
+    {
+        begin_rename(app, ctx);
+    }
+}
+
+/// The warning marker at the end of the name cell for footage that can't be decoded.
+fn problem_marker(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &RowGeom, name_w: f32, id: ItemId, why: &str) {
+    let t = app.tokens;
+    let RowGeom { lp, list, r, .. } = *g;
+    let m = Rect::from_center_size(pos2(r.min.x + name_w - 8.0, r.center().y), vec2(13.0, 12.0));
+    lp.add(egui::Shape::convex_polygon(vec![m.center_top(), m.right_bottom(), m.left_bottom()], t.warning, Stroke::NONE));
+    lp.text(m.center() + vec2(0.0, 1.5), Align2::CENTER_CENTER, "!", Tokens::semibold(9.0), Color32::BLACK);
+    ui.interact(m.expand(2.0).intersect(list), egui::Id::unique(("pproblem", id.0)), Sense::hover()).on_hover_text(why);
+    app.auto.add(&format!("project.item.{}.problem", id.0), m, why);
+}
+
+/// Selection box over the rows it touches (#203); Shift or Cmd/Ctrl adds to the selection.
+fn marquee_select(app: &mut EffectcraftApp, ctx: &egui::Context, lp: &egui::Painter, list: Rect, empty: &egui::Response, rows: &[(ItemId, usize)]) {
+    let t = app.tokens;
+    let adding = ctx.input(|i| i.modifiers.shift || i.modifiers.command);
     if empty.clicked() && !adding {
         app.session.state.project_selection.clear();
     }
@@ -1142,6 +994,333 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
         }
     }
+}
+
+/// Where a row is drawn: its clipped painter, the list, the row rectangle and the indented x.
+#[derive(Clone, Copy)]
+struct RowGeom<'a> {
+    lp: &'a egui::Painter,
+    list: Rect,
+    r: Rect,
+    x0: f32,
+}
+
+/// Vertical scrolling: only the rows in view are drawn (and registered), so a project with
+/// thousands of items costs what one screenful does. Returns the scroll offset and its maximum.
+fn update_scroll(app: &mut EffectcraftApp, ui: &egui::Ui, ctx: &egui::Context, list: Rect, rows: &[(ItemId, usize)], moved: Option<ItemId>) -> (f32, f32) {
+    let content_h = rows.len() as f32 * ROW_H;
+    let max_scroll = (content_h - list.height() + ROW_H).max(0.0);
+    if ui.rect_contains_pointer(list) {
+        let (dy, shift) = ui.input(|i| (i.smooth_scroll_delta.y, i.modifiers.shift));
+        if !shift && dy != 0.0 {
+            app.ui.project_scroll -= dy;
+        }
+    }
+    // A selection made elsewhere (a command, an agent, the viewer) scrolls into view.
+    let sel_key = selection_seen_id();
+    let sel_now = app.session.state.project_selection.last().map(|i| i.0);
+    if ctx.data(|d| d.get_temp::<Option<u64>>(sel_key)) != Some(sel_now) {
+        ctx.data_mut(|d| d.insert_temp(sel_key, sel_now));
+        if let Some(row) = sel_now.and_then(|s| rows.iter().position(|(id, _)| id.0 == s)) {
+            let top = row as f32 * ROW_H;
+            if top < app.ui.project_scroll {
+                app.ui.project_scroll = top;
+            } else if top + ROW_H > app.ui.project_scroll + list.height() {
+                app.ui.project_scroll = top + ROW_H - list.height();
+            }
+        }
+    }
+    // The arrow keys' item scrolls into view (Shift+Up extends upward, past the selection's end).
+    if let Some(row) = moved.and_then(|m| rows.iter().position(|(id, _)| *id == m)) {
+        let top = row as f32 * ROW_H;
+        // Not `clamp`: a panel shorter than a row would make its bounds cross. The row's top wins.
+        app.ui.project_scroll = app.ui.project_scroll.max(top + ROW_H - list.height()).min(top);
+    }
+    app.ui.project_scroll = app.ui.project_scroll.clamp(0.0, max_scroll);
+    (app.ui.project_scroll, max_scroll)
+}
+
+/// The folder's open / close twirl (Alt / Cmd-click twirls every folder inside it too).
+fn folder_twirl(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &RowGeom, it: &effectcraft_engine::project::Item) {
+    let t = app.tokens;
+    let RowGeom { r, x0, .. } = *g;
+    let open = app.ui.project_open_folders.contains(&it.id.0);
+    let tw = Rect::from_center_size(pos2(x0 + 4.0, r.center().y), vec2(12.0, 12.0));
+    let tresp = widgets::twirl(ui, tw, open, egui::Id::unique(("pf", it.id.0)), &t);
+    tresp.widget_info(|| {
+        let name = crate::i18n::tr_args(if open { "Close folder {}" } else { "Open folder {}" }, &[&it.name]);
+        egui::WidgetInfo::labeled(egui::Role::Button, true, name)
+    });
+    if tresp.clicked() {
+        // Alt/Cmd-click twirls every folder inside it too.
+        let mut ids = vec![it.id];
+        if ui.input(|i| i.modifiers.alt || i.modifiers.command) {
+            let mut at = 0;
+            while let Some(f) = ids.get(at).copied() {
+                ids.extend(app.session.project.children(Some(f)).into_iter().filter(|c| c.is_folder()).map(|c| c.id));
+                at += 1;
+            }
+        }
+        for f in ids {
+            if open {
+                app.ui.project_open_folders.remove(&f.0);
+            } else {
+                app.ui.project_open_folders.insert(f.0);
+            }
+        }
+    }
+    app.auto.add(&format!("project.item.{}.twirl", it.id.0), tw, &it.name);
+}
+
+/// Proxy indicator: filled = the proxy is used, hollow = set but off. Click to switch.
+fn proxy_indicator(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    g: &RowGeom,
+    it: &effectcraft_engine::project::Item,
+    actions: &mut Vec<(String, serde_json::Value)>,
+) {
+    let t = app.tokens;
+    let RowGeom { lp, list, r, x0 } = *g;
+    if let Some(px) = it.proxy.as_ref() {
+        let pr = Rect::from_center_size(pos2(x0 + 4.0, r.center().y), vec2(9.0, 9.0));
+        if px.enabled {
+            lp.rect_filled(pr, 1.0, t.text);
+        } else {
+            lp.rect_stroke(pr, 1.0, Stroke::new(1.0, t.text), egui::StrokeKind::Inside);
+        }
+        let presp = ui.interact(pr.expand(2.0).intersect(list), egui::Id::unique(("pproxy", it.id.0)), Sense::click()).on_hover_text(format!(
+            "Proxy: {} ({})",
+            px.footage.path,
+            if px.enabled { "in use" } else { "off" }
+        ));
+        app.auto.add(&format!("project.item.{}.proxy", it.id.0), pr, if px.enabled { "Proxy in use" } else { "Proxy off" });
+        presp.widget_info(|| {
+            let name = crate::i18n::tr_args(if px.enabled { "Proxy of {}: in use" } else { "Proxy of {}: off" }, &[&it.name]);
+            egui::WidgetInfo::labeled(egui::Role::Button, true, name)
+        });
+        if presp.clicked() {
+            actions.push(("file.useProxy".into(), json!({"item": it.id.0})));
+        }
+    }
+}
+
+/// The label swatch: click for the label colour menu.
+fn label_swatch(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    g: &RowGeom,
+    it: &effectcraft_engine::project::Item,
+    label_x: f32,
+    selected: bool,
+    actions: &mut Vec<(String, serde_json::Value)>,
+) {
+    let t = app.tokens;
+    let RowGeom { lp, list, r, .. } = *g;
+    let sw = Rect::from_center_size(pos2(label_x, r.center().y), vec2(10.0, 10.0));
+    lp.rect_filled(sw, 2.0, t.label(it.label));
+    let sresp = ui.interact(sw.expand(3.0).intersect(list), egui::Id::unique(("plabel", it.id.0)), Sense::click());
+    app.auto.add(&format!("project.item.{}.label", it.id.0), sw, it.label.name());
+    sresp.widget_info(|| {
+        let name = crate::i18n::tr_args("Label of {}: {}", &[&it.name, &app.session.prefs.label_name(it.label)]);
+        egui::WidgetInfo::labeled(egui::Role::Button, true, name)
+    });
+    let pop = egui::Id::unique(("plabel-pop", it.id.0));
+    if sresp.clicked() || sresp.secondary_clicked() {
+        widgets::open_popup(ui, pop);
+    }
+    if let Some(l) = widgets::label_popup(ui, pop, sw.left_bottom(), it.label, |l| app.session.prefs.label_name(l), &t) {
+        actions.push(("project.setLabel".into(), json!({"items": targets(app, it.id, selected), "label": label_index(l)})));
+    }
+}
+
+/// The Project panel: the selected item's thumbnail and details (with the comps that use it), the
+/// search field, sortable column headers, and the item rows (folders, comps, footage and solids)
+/// with selection, Shift/Cmd ranges, keyboard navigation, inline rename, drag-and-drop move,
+/// marquee selection and context menus. Only the rows in view are drawn. File commands are queued
+/// and run through [`crate::menus::invoke`] at the end, with failures shown in `app.ui.status`.
+pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+    let t = app.tokens;
+    let p = ui.painter().clone();
+    let ctx = ui.ctx().clone();
+    // Preview header.
+    let head = Rect::from_min_size(rect.min, vec2(rect.width(), 74.0));
+    details_header(app, ui, &p, &ctx, head);
+    // Search.
+    let sr = Rect::from_min_size(pos2(rect.min.x + 8.0, head.max.y + 2.0), vec2(rect.width() - 16.0, 22.0));
+    let mut q = app.ui.project_search.clone();
+    widgets::search_field(ui, sr, &mut q, crate::i18n::tr("Search project"), &t);
+    app.ui.project_search = q;
+    app.auto.add("project.search", sr, "Search");
+    // Column header: Name, Label, then the visible optional columns.
+    let hdr = Rect::from_min_size(pos2(rect.min.x, sr.max.y + 6.0), vec2(rect.width(), 20.0));
+    p.line_segment([hdr.left_bottom(), hdr.right_bottom()], Stroke::new(1.0, t.separator));
+    let cl = layout_columns(app, rect);
+    let (name_w, label_x, opt_x0, overflow, hscroll) = (cl.name_w, cl.label_x, cl.opt_x0, cl.overflow, cl.hscroll);
+    draw_header(app, ui, &p, hdr, &cl);
+    // Rows.
+    let footer_h = 28.0;
+    let list = Rect::from_min_max(pos2(rect.min.x, hdr.max.y), pos2(rect.max.x, rect.max.y - footer_h));
+    let lp = p.with_clip_rect(list);
+    // The list's empty area (under the rows and the scroll bar, which take their own clicks):
+    // a click deselects, a drag draws a selection box, a double-click imports, as in After
+    // Effects (File ▸ Import ▸ File...).
+    // Not a Tab stop: the keyboard reaches the rows, and nothing else here takes a key.
+    let empty = ui.interact(list, egui::Id::unique("proj-empty"), Sense::CLICK | Sense::DRAG);
+    app.auto.add("project.empty", list, "Double-click to import files; drag to select items; right-click for project actions");
+    hscroll_wheel(app, ui, list, overflow);
+    let moved = keyboard_nav(app, &ctx);
+    let rows = visible_rows(app);
+    enter_renames(app, &ctx);
+    let editing: Option<Editing> = ctx.data(|d| d.get_temp(edit_id()));
+    let dragging = egui::DragAndDrop::payload::<DragPayload>(&ctx).and_then(|p| match *p {
+        DragPayload::Item(i) => Some(i),
+        _ => None,
+    });
+    let hover_y = ctx.pointer_hover_pos().filter(|p| list.contains(*p)).map(|p| p.y);
+    let mut drop_row: Option<ItemId> = None;
+    let mut actions: Vec<(String, serde_json::Value)> = vec![];
+    let (scroll, max_scroll) = update_scroll(app, ui, &ctx, list, &rows, moved);
+    let first = ((scroll / ROW_H).floor() as usize).min(rows.len());
+    let mut y = list.min.y - (scroll - first as f32 * ROW_H);
+    let project = app.session.project.clone();
+    for (i, (id, depth)) in rows.iter().enumerate().skip(first) {
+        let Some(it) = project.item(*id) else { continue };
+        let r = Rect::from_min_size(pos2(list.min.x, y), vec2(list.width(), ROW_H));
+        y += ROW_H;
+        if r.min.y > list.max.y {
+            break;
+        }
+        if hover_y.is_some_and(|hy| hy >= r.min.y && hy < r.max.y) {
+            drop_row = Some(*id);
+        }
+        let selected = app.session.state.project_selection.contains(id);
+        lp.rect_filled(
+            r,
+            0.0,
+            // Flat rows like After Effects' Project panel (no stripes).
+            if selected { t.row_selected } else { t.row },
+        );
+        // The row's click / drag area goes first, so the twirl, proxy, label and comment widgets
+        // on top of it take their own clicks.
+        let mut resp = ui.interact(r.intersect(list), row_id(*id), Sense::click_and_drag());
+        app.auto.add(&format!("project.item.{}", id.0), r, &it.name);
+        // For screen readers: a tree item named by the item and its type, with its selection,
+        // depth and (a folder) open state. One Tab stop per row; the panel's keys then apply.
+        let open = it.is_folder().then(|| app.ui.project_open_folders.contains(&id.0) || !app.ui.project_search.is_empty());
+        resp.widget_info(|| egui::WidgetInfo::labeled(egui::Role::TreeItem, true, format!("{}, {}", it.name, crate::i18n::tr(it.type_name()))));
+        ctx.accesskit_node_builder(resp.id, |n| {
+            n.set_selected(selected);
+            n.set_level(depth.saturating_add(1));
+            if let Some(open) = open {
+                n.set_expanded(open);
+            }
+        });
+        if resp.has_focus() {
+            ctx.data_mut(|d| d.insert_temp(focused_row_id(), *id));
+        }
+        if resp.gained_focus() {
+            app.ui.focused = crate::dock::PanelKind::Project;
+        }
+        let _ = i;
+        let x0 = r.min.x + 8.0 + 14.0 * *depth as f32;
+        let g = RowGeom { lp: &lp, list, r, x0 };
+        if it.is_folder() {
+            folder_twirl(app, ui, &g, it);
+        }
+        icons::paint(&lp, Rect::from_center_size(pos2(x0 + 18.0, r.center().y), vec2(14.0, 14.0)), item_icon(it), t.text_dim);
+        proxy_indicator(app, ui, &g, it, &mut actions);
+        // Footage that can't be decoded (no decoder for its codec / profile): a warning marker
+        // at the end of the name cell, the reason on hover.
+        let problem = match &it.kind {
+            ItemKind::Footage(f) => app.session.footage.problem(f),
+            _ => None,
+        };
+        let name_clip =
+            Rect::from_min_max(pos2(x0 + 30.0, r.min.y), pos2(r.min.x + name_w + 4.0 - if problem.is_some() { 16.0 } else { 0.0 }, r.max.y)).intersect(list);
+        if let Some(why) = &problem {
+            problem_marker(app, ui, &g, name_w, it.id, why);
+        }
+        let name_rect = Rect::from_min_max(pos2(x0 + 28.0, r.min.y + 2.0), pos2(r.min.x + name_w + 2.0, r.max.y - 2.0));
+        if !cell_edit(app, ui, &mut actions, &editing, id.0, "name", name_rect) {
+            // The selected item's name sits in a light cell with dark text.
+            if selected {
+                let g = lp.layout_no_wrap(it.name.clone(), Tokens::ui(12.0), Color32::BLACK);
+                let cell = Rect::from_min_max(pos2(x0 + 27.0, r.min.y + 1.0), pos2((x0 + 33.0 + g.size().x).min(name_clip.max.x), r.max.y - 1.0));
+                lp.with_clip_rect(name_clip.expand2(vec2(3.0, 0.0))).rect_filled(cell, 0.0, Color32::from_rgb(0xa6, 0xa6, 0xa6));
+            }
+            // Long names end in "…" before the label column instead of being cut mid-glyph.
+            widgets::text_fit(
+                &lp.with_clip_rect(name_clip),
+                pos2(x0 + 30.0, r.center().y),
+                Align2::LEFT_CENTER,
+                &it.name,
+                Tokens::ui(12.0),
+                name_clip.max.x - (x0 + 30.0) - 2.0,
+                if selected { Color32::from_gray(0x16) } else { t.text },
+            );
+        }
+        label_swatch(app, ui, &g, it, label_x, selected, &mut actions);
+        if let Some(extra) = optional_cells(app, ui, &g, it, &cl, &editing, &mut actions) {
+            resp = resp.union(extra);
+        }
+        if dragging.is_some_and(|d| d != id.0) && drop_row == Some(*id) && it.is_folder() {
+            lp.rect_stroke(r.shrink(1.0), 2.0, Stroke::new(1.5, t.accent), egui::StrokeKind::Inside);
+        }
+        // The row with keyboard focus (Tab, or the arrow keys after it) shows a focus ring.
+        if ctx.memory(|m| m.has_focus(row_id(*id))) {
+            lp.rect_stroke(r.shrink(0.5), 0.0, Stroke::new(1.0, t.accent), egui::StrokeKind::Inside);
+        }
+        // Part of the row: not a second Tab stop.
+        let nresp = ui.interact(name_clip, egui::Id::unique(("pname", id.0)), Sense::CLICK | Sense::DRAG);
+        app.auto.add(&format!("project.item.{}.name", id.0), name_clip, &it.name);
+        let resp = resp.union(nresp);
+        if resp.clicked() {
+            select_click(app, ui, &ctx, *id, &rows);
+        }
+        // Double-click opens the item, as in After Effects (a comp gets its own Timeline tab and
+        // the viewer); Enter or the context menu renames.
+        if resp.double_clicked() {
+            open_item(app, it, *id, &mut actions);
+        }
+        if resp.drag_started() {
+            egui::DragAndDrop::set_payload(&ctx, DragPayload::Item(id.0));
+        }
+        // Right-clicking an item selects it (After Effects): the menu's File commands act on the
+        // selection.
+        if resp.secondary_clicked() && !selected {
+            app.session.state.project_selection = vec![*id];
+        }
+        crate::widgets::context_menu(&resp, |ui| item_menu(app, ui, &ctx, it, *id, selected, &mut actions));
+    }
+    // The scroll bars, over the rows (which would take their presses otherwise).
+    if overflow > 0.0 {
+        let track = Rect::from_min_max(pos2(opt_x0, list.max.y - 5.0), pos2(rect.max.x - 4.0, list.max.y - 1.0));
+        app.ui.project_hscroll = widgets::scroll_bar(ui, &mut app.auto, "project.hscroll", track, hscroll, overflow, &t);
+    }
+    if max_scroll > 0.0 {
+        let track = Rect::from_min_max(pos2(rect.max.x - 6.0, list.min.y + 1.0), pos2(rect.max.x - 2.0, list.max.y - 7.0));
+        app.ui.project_scroll = widgets::scroll_bar(ui, &mut app.auto, "project.vscroll", track, scroll, max_scroll, &t);
+    }
+    drop_targets(app, &ctx, &lp, list, DropState { dragging, row: drop_row, hovering: hover_y.is_some() }, &mut actions);
+    let foot = Rect::from_min_max(pos2(rect.min.x, rect.max.y - footer_h), rect.max);
+    footer(app, ui, &p, foot, &mut actions);
+    if empty.double_clicked() {
+        actions.push(("file.import".into(), json!({})));
+    }
+    crate::widgets::context_menu(&empty, |ui| {
+        for (key, label, command) in
+            [("newComp", "New Composition…", "comp.new"), ("newFolder", "New Folder", "project.newFolder"), ("import", "Import File…", "file.import")]
+        {
+            let response = ui.button(label);
+            app.auto.add(&format!("project.context.{key}"), response.rect, label);
+            if response.clicked() {
+                actions.push((command.into(), json!({})));
+                ui.close();
+            }
+        }
+    });
+    marquee_select(app, &ctx, &lp, list, &empty, &rows);
     for (id, params) in actions {
         if let Err(e) = crate::menus::invoke(app, &ctx, &id, params) {
             app.ui.status = e;
diff --git a/crates/ui-egui/src/panels/properties.rs b/crates/ui-egui/src/panels/properties.rs
index c26bb5030..c35108937 100644
--- a/crates/ui-egui/src/panels/properties.rs
+++ b/crates/ui-egui/src/panels/properties.rs
@@ -91,7 +91,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
 
     // ---------------------------------------------------------------- Layer Transform
     if let Some(tr) = layer.transform().cloned() {
-        section_header(app, ui, &p, x0, w, y, "Layer Transform", "properties.transform");
+        section_header(app, &p, x0, w, y, "Layer Transform", "properties.transform");
         let rr = Rect::from_min_size(pos2(x0 + w - 40.0, y), vec2(40.0, ROW_H));
         let resp = ui.interact(rr, egui::Id::unique("props-reset"), Sense::click());
         p.text(rr.right_center(), Align2::RIGHT_CENTER, crate::i18n::tr("Reset"), Tokens::ui(12.0), if resp.hovered() { t.accent_hover } else { t.accent });
@@ -124,7 +124,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         divider(&p, x0, w, y - 4.0, &t);
         y = paragraph_section(app, ui, &p, &layer, &doc, x0, w, y + 4.0, &mut actions);
         divider(&p, x0, w, y - 4.0, &t);
-        section_header(app, ui, &p, x0, w, y + 4.0, "Text Animation", "properties.textAnimation");
+        section_header(app, &p, x0, w, y + 4.0, "Text Animation", "properties.textAnimation");
         y += ROW_H + 10.0;
         // Both buttons grow with their (translated) labels; English keeps its 116 / 84 px.
         let text_w = |s: &str| p.layout_no_wrap(s.to_string(), Tokens::ui(12.0), t.text).size().x;
@@ -180,11 +180,10 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
 }
 
-fn section_header(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, x0: f32, w: f32, y: f32, title: &str, auto: &str) {
+fn section_header(app: &mut EffectcraftApp, p: &egui::Painter, x0: f32, w: f32, y: f32, title: &str, auto: &str) {
     let t = app.tokens;
     p.text(pos2(x0, y + ROW_H / 2.0), Align2::LEFT_CENTER, title, Tokens::semibold(12.0), t.text);
     let r = Rect::from_min_size(pos2(x0, y), vec2(w, ROW_H));
-    let _ = ui;
     app.auto.add(auto, r, title);
 }
 
@@ -286,7 +285,14 @@ fn transform_row(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter,
         }
         Value::Scalar(v) => {
             let range = if pr.name == "Opacity" { (0.0, 100.0) } else { (-1e9, 1e9) };
-            let (vr, nv, _) = widgets::hot_number_at(ui, pos2(vx, cy - 9.0), egui::Id::unique(("props-v", uid)), *v, 0.5, range, decimals(*v), suffix, &t);
+            let (vr, nv, _) = widgets::hot_number_at(
+                ui,
+                pos2(vx, cy - 9.0),
+                egui::Id::unique(("props-v", uid)),
+                *v,
+                &widgets::HotSpec { speed: 0.5, range, decimals: decimals(*v), suffix },
+                &t,
+            );
             app.auto.add(&format!("{base}.value"), vr, &pr.name);
             if let Some(nv) = nv {
                 set(actions, json!(nv));
@@ -311,8 +317,14 @@ fn transform_row(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter,
                 }
             }
             for d in 0..n.min(c.len()) {
-                let (vr, nv, _) =
-                    widgets::hot_number_at(ui, pos2(x, cy - 9.0), egui::Id::unique(("props-v", uid, d)), c[d], 1.0, (-1e9, 1e9), decimals(c[d]), suffix, &t);
+                let (vr, nv, _) = widgets::hot_number_at(
+                    ui,
+                    pos2(x, cy - 9.0),
+                    egui::Id::unique(("props-v", uid, d)),
+                    c[d],
+                    &widgets::HotSpec { speed: 1.0, range: (-1e9, 1e9), decimals: decimals(c[d]), suffix },
+                    &t,
+                );
                 app.auto.add(&format!("{base}.value.{d}"), vr, &pr.name);
                 if let Some(nv) = nv {
                     let mut nc = c.clone();
@@ -358,7 +370,7 @@ fn text_section(
         v["layer"] = json!(lid);
         actions.push(("layer.setText".into(), v));
     };
-    section_header(app, ui, p, x0, w, y, "Text", "properties.text");
+    section_header(app, p, x0, w, y, "Text", "properties.text");
     y += ROW_H + 4.0;
     // Font family and style.
     let fr = Rect::from_min_size(pos2(x0, y), vec2(w, 22.0));
@@ -383,7 +395,14 @@ fn text_section(
     let col2 = x0 + w / 2.0;
     let field = |app: &mut EffectcraftApp, ui: &mut egui::Ui, x: f32, y: f32, glyph: &str, key: &str, v: f64, range: (f64, f64), suffix: &str| {
         p.text(pos2(x, y + 9.0), Align2::LEFT_CENTER, glyph, Tokens::semibold(11.0), t.text_dim);
-        let (r, nv, _) = widgets::hot_number_at(ui, pos2(x + 26.0, y), egui::Id::unique(("props-text", key)), v, 0.5, range, decimals(v), suffix, &t);
+        let (r, nv, _) = widgets::hot_number_at(
+            ui,
+            pos2(x + 26.0, y),
+            egui::Id::unique(("props-text", key)),
+            v,
+            &widgets::HotSpec { speed: 0.5, range, decimals: decimals(v), suffix },
+            &t,
+        );
         app.auto.add(&format!("properties.text.{key}"), r, key);
         nv
     };
@@ -462,7 +481,7 @@ fn paragraph_section(
     actions: &mut Actions,
 ) -> f32 {
     let t = app.tokens;
-    section_header(app, ui, p, x0, w, y, "Paragraph", "properties.paragraph");
+    section_header(app, p, x0, w, y, "Paragraph", "properties.paragraph");
     y += ROW_H + 4.0;
     for (i, (j, key)) in ALIGNS.into_iter().enumerate() {
         let r = Rect::from_min_size(pos2(x0 + i as f32 * 26.0, y), vec2(22.0, 22.0));
diff --git a/crates/ui-egui/src/panels/render_queue.rs b/crates/ui-egui/src/panels/render_queue.rs
index c002558ab..5e39a30c2 100644
--- a/crates/ui-egui/src/panels/render_queue.rs
+++ b/crates/ui-egui/src/panels/render_queue.rs
@@ -415,20 +415,21 @@ fn pick_output(app: &EffectcraftApp, it: &RenderQueueItem) -> Option<Option<Stri
     app.hooks.save_dialog(&app.session.resolve_output(it).unwrap_or_default())
 }
 
-/// The Render Queue panel: the Current Render strip (elapsed and remaining time, Render/Stop and
-/// Notify, plus the progress bar), the column header, the queued items with their output template,
-/// status and timings, and the footer totals. Comps dragged from the Project are queued on
-/// release. The open items and the selected item are kept in egui temp data; output-template forms
-/// open through a small form, and every change runs a `renderQueue.*` command.
-pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+/// A `renderQueue.*` command queued while drawing, run after the frame.
+type Action = (&'static str, Value);
+
+/// What the panel's sections read: the queue, the running render (if any) and the formats.
+#[derive(Clone, Copy)]
+struct RqView<'a> {
+    queue: &'a [RenderQueueItem],
+    progress: Option<&'a effectcraft_engine::render_queue::JobState>,
+    rendering: bool,
+    available: &'a [OutputFormat],
+}
+
+/// Comps dragged from the Project over the panel: an outline while hovering, queued on release.
+fn queue_drop(app: &EffectcraftApp, ui: &egui::Ui, rect: Rect, p: &egui::Painter, rendering: bool, actions: &mut Vec<Action>) {
     let t = app.tokens;
-    let p = ui.painter().with_clip_rect(rect);
-    let queue: Vec<RenderQueueItem> = app.session.project.render_queue.clone();
-    let progress = app.session.render_progress();
-    let rendering = app.session.is_rendering();
-    let available = app.session.exporter.as_ref().map(|e| e.formats()).unwrap_or_default();
-    let mut actions: Vec<(&'static str, Value)> = Vec::new();
-    app.auto.add("renderQueue.drop", rect, "Drop compositions to queue");
     if !rendering
         && let Some(crate::panels::DragPayload::Item(id)) = egui::DragAndDrop::payload::<crate::panels::DragPayload>(ui.ctx()).as_deref()
         && app.session.project.comp(effectcraft_engine::project::ItemId(*id)).is_some()
@@ -448,14 +449,14 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             p.rect_stroke(rect.shrink(2.0), 0.0, Stroke::new(2.0, t.accent), StrokeKind::Inside);
         }
     }
-    let mut forms: Vec<(RenderQueueItem, String)> = Vec::new();
-    let state_id = egui::Id::unique("rq-ui");
-    let (mut open, mut selected): (Vec<u64>, Option<u64>) = ui.data(|d| d.get_temp(state_id).unwrap_or_default());
+}
 
-    // ---------------------------------------------------------- Current Render strip
-    let top = Rect::from_min_size(rect.min, vec2(rect.width(), TOP_H));
-    p.rect_filled(top, 0.0, t.tl_ruler_bg);
-    let x0 = rect.min.x + 12.0;
+/// The Current Render strip inside `top`: title, elapsed / remaining time, Render, Stop, Notify
+/// and the progress bar.
+fn current_render_strip(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, top: Rect, rq: &RqView, actions: &mut Vec<Action>) {
+    let t = app.tokens;
+    let RqView { queue, progress, rendering, available } = *rq;
+    let x0 = top.min.x + 12.0;
     p.text(pos2(x0, top.min.y + 16.0), Align2::LEFT_CENTER, tr("Current Render"), Tokens::semibold(12.5), t.text);
     let cur_item = progress.as_ref().and_then(|p| p.current).and_then(|id| queue.iter().find(|i| i.id == id));
     let cur_name = cur_item.and_then(|i| app.session.project.item(i.comp)).map(|i| i.name.clone());
@@ -515,6 +516,194 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     };
     p.text(pos2(bar.min.x + 8.0, bar.center().y), Align2::LEFT_CENTER, bar_text, Tokens::ui(11.5), t.text);
     app.auto.add("renderQueue.progress", bar, &format!("{:.0}%", frac * 100.0));
+}
+
+/// The footer: the message line and the totals.
+fn footer(p: &egui::Painter, rect: Rect, rq: &RqView, t: &Tokens) {
+    let RqView { queue, progress, rendering, .. } = *rq;
+    let foot = Rect::from_min_max(pos2(rect.min.x, rect.max.y - FOOT_H), rect.max);
+    p.rect_filled(foot, 0.0, t.tl_ruler_bg);
+    p.line_segment([foot.left_top(), foot.right_top()], Stroke::new(1.0, t.separator));
+    let msg = match &progress {
+        Some(pr) if rendering => format!("Message: Rendering {} of {}", (pr.items_done + 1).min(pr.items_total), pr.items_total),
+        _ => {
+            let done = queue.iter().filter(|i| i.status == RenderStatus::Done).count();
+            format!("Message: {done} of {} done", queue.len())
+        }
+    };
+    p.text(pos2(foot.min.x + 12.0, foot.center().y), Align2::LEFT_CENTER, msg, Tokens::ui(11.0), t.text_dim);
+    let started = queue.iter().filter(|i| i.started.is_some()).count();
+    let total: f64 = queue.iter().filter_map(|i| i.render_time).sum();
+    p.text(
+        pos2(foot.max.x - 12.0, foot.center().y),
+        Align2::RIGHT_CENTER,
+        format!("Renders Started: {started}     Total Time Elapsed: {}", hms(progress.as_ref().filter(|_| rendering).map(|p| p.elapsed).unwrap_or(total))),
+        Tokens::ui(11.0),
+        t.text_dim,
+    );
+}
+
+/// An item row's context menu: Duplicate, Remove and Move Up / Down (row `k` of `len`).
+fn row_menu(ui: &mut egui::Ui, actions: &mut Vec<Action>, item_id: u64, k: usize, len: usize) {
+    if ui.button(tr("Duplicate")).clicked() {
+        actions.push(("renderQueue.duplicate", json!({"item": item_id})));
+        ui.close();
+    }
+    if ui.button(tr("Remove")).clicked() {
+        actions.push(("renderQueue.remove", json!({"item": item_id})));
+        ui.close();
+    }
+    if k > 0 && ui.button(tr("Move Up")).clicked() {
+        actions.push(("renderQueue.move", json!({"item": item_id, "to": k})));
+        ui.close();
+    }
+    if k + 1 < len && ui.button(tr("Move Down")).clicked() {
+        actions.push(("renderQueue.move", json!({"item": item_id, "to": k + 2})));
+        ui.close();
+    }
+}
+
+/// Log: Errors Only / Plus Settings / Plus Per Frame Info.
+fn log_dropdown(app: &mut EffectcraftApp, ui: &mut egui::Ui, row: &ItemRow, it: &RenderQueueItem, actions: &mut Vec<Action>) {
+    let ItemRow { lp, r, n, rendering, .. } = *row;
+    let t = app.tokens;
+    let aid = |s: &str| format!("renderQueue.item.{n}.{s}");
+    let ld = Rect::from_min_size(pos2(r.max.x - 190.0, r.min.y + 3.0), vec2(150.0, ROW_H - 6.0));
+    lp.text(pos2(ld.min.x - 6.0, r.center().y), Align2::RIGHT_CENTER, tr("Log:"), Tokens::ui(11.5), t.text_dim);
+    let lid = egui::Id::unique(("rq-log", it.id));
+    if widgets::dropdown(ui, ld, it.log.label(), &t, lid).clicked() && !rendering {
+        widgets::open_popup(ui, lid);
+    }
+    let llabels: Vec<String> = RenderLog::ALL.iter().map(|l| mark(it.log == *l, l.label())).collect();
+    if let Some(i) = widgets::popup_menu(ui, lid, ld.left_bottom(), &llabels, None) {
+        actions.push(("renderQueue.setLog", json!({"item": it.id, "log": RenderLog::ALL[i].label()})));
+    }
+    app.auto.add(&aid("log"), ld, it.log.label());
+}
+
+/// Where an item row's expanded line is drawn.
+#[derive(Clone, Copy)]
+struct ItemRow<'a> {
+    lp: &'a egui::Painter,
+    list: Rect,
+    r: Rect,
+    /// The item's 1-based position in the queue.
+    n: usize,
+    rendering: bool,
+}
+
+/// The expanded "Output To" line: the template menu, and the file name (click to choose it or
+/// edit the template in place).
+fn output_to(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    row: &ItemRow,
+    it: &RenderQueueItem,
+    dd_right: f32,
+    editing: &mut Option<(u64, String)>,
+    actions: &mut Vec<Action>,
+) {
+    let ItemRow { lp, list, r, n, rendering } = *row;
+    let t = app.tokens;
+    let aid = |s: &str| format!("renderQueue.item.{n}.{s}");
+    let ox = dd_right + 14.0;
+    lp.text(pos2(ox, r.center().y), Align2::LEFT_CENTER, tr("Output To:"), Tokens::ui(11.5), t.text_dim);
+    let odd = Rect::from_min_size(pos2(ox + 62.0, r.min.y + 3.0), vec2(22.0, ROW_H - 6.0));
+    let oid = egui::Id::unique(("rq-out", it.id));
+    if widgets::dropdown(ui, odd, "", &t, oid).clicked() && !rendering {
+        widgets::open_popup(ui, oid);
+    }
+    app.auto.add(&aid("outputTo"), odd, "Output To");
+    let omenu = output_to_menu(it);
+    let olabels: Vec<String> = omenu.iter().map(|(l, _)| l.clone()).collect();
+    if let Some(i) = widgets::popup_menu(ui, oid, odd.left_bottom(), &olabels, None) {
+        if omenu[i].1.get("choose").is_some() {
+            match pick_output(app, it) {
+                Some(Some(path)) => actions.push(("renderQueue.setOutput", json!({"item": it.id, "path": path}))),
+                Some(None) => {}
+                None => *editing = Some((it.id, it.output.output.clone())),
+            }
+        } else {
+            let mut params = omenu[i].1.clone();
+            params["item"] = json!(it.id);
+            actions.push(("renderQueue.setOutput", params));
+        }
+    }
+    let path_rect = Rect::from_min_max(pos2(odd.max.x + 6.0, r.min.y + 2.0), pos2(r.max.x - 8.0, r.max.y - 2.0));
+    if editing.as_ref().is_some_and(|(id, _)| *id == it.id) {
+        let mut buf = editing.as_ref().map(|(_, b)| b.clone()).unwrap_or_default();
+        let mut child = ui.new_child(egui::UiBuilder::new().max_rect(path_rect));
+        let resp = child.add(egui::TextEdit::singleline(&mut buf).desired_width(path_rect.width()).font(Tokens::ui(11.5)));
+        if resp.lost_focus() {
+            if ui.input(|i| i.key_pressed(egui::Key::Enter)) && !buf.trim().is_empty() {
+                actions.push(("renderQueue.setOutput", json!({"item": it.id, "path": buf.trim()})));
+            }
+            *editing = None;
+        } else {
+            widgets::keep_focus(ui.ctx(), &resp, &buf);
+            *editing = Some((it.id, buf));
+        }
+    } else {
+        let shown = app.session.resolve_output(it).unwrap_or_else(|| "Not yet specified".into());
+        let resp = ui.interact(path_rect, egui::Id::unique(("rq-path", it.id)), Sense::click());
+        let col = if resp.hovered() { t.accent_hover } else { t.hot_text };
+        lp.with_clip_rect(path_rect.intersect(list)).text(pos2(path_rect.min.x, r.center().y), Align2::LEFT_CENTER, &shown, Tokens::ui(11.5), col);
+        // Clicking the file name opens the save dialog (Output Movie To); Alt-click, or a
+        // host without one, edits the name template in place.
+        let dialog = app.hooks.pick_save_file.is_some();
+        if resp.clicked() && !rendering {
+            let picked = if ui.input(|i| i.modifiers.alt) { None } else { pick_output(app, it) };
+            match picked {
+                Some(Some(path)) => actions.push(("renderQueue.setOutput", json!({"item": it.id, "path": path}))),
+                Some(None) => {}
+                None => *editing = Some((it.id, it.output.output.clone())),
+            }
+        }
+        let how = if dialog { "Click to choose where to save; Alt-click to edit the template" } else { "Click to edit" };
+        resp.on_hover_text(tr_args("Template: {}\n{}", &[&it.output.output, &how]));
+        app.auto.add(&aid("outputPath"), path_rect, &shown);
+    }
+}
+
+/// Delete removes the selected item when the panel has focus (`allowed`: not editing a path and
+/// not rendering).
+fn delete_selected(app: &EffectcraftApp, ui: &egui::Ui, allowed: bool, selected: &mut Option<u64>, actions: &mut Vec<Action>) {
+    if app.ui.focused == crate::dock::PanelKind::RenderQueue
+        && allowed
+        && let Some(id) = *selected
+        && app.dialog.is_none()
+        && ui.input(|i| i.key_pressed(egui::Key::Delete) || i.key_pressed(egui::Key::Backspace))
+        && !ui.ctx().egui_wants_keyboard_input()
+    {
+        actions.push(("renderQueue.remove", json!({"item": id})));
+        *selected = None;
+    }
+}
+
+/// The Render Queue panel: the Current Render strip (elapsed and remaining time, Render/Stop and
+/// Notify, plus the progress bar), the column header, the queued items with their output template,
+/// status and timings, and the footer totals. Comps dragged from the Project are queued on
+/// release. The open items and the selected item are kept in egui temp data; output-template forms
+/// open through a small form, and every change runs a `renderQueue.*` command.
+pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+    let t = app.tokens;
+    let p = ui.painter().with_clip_rect(rect);
+    let queue: Vec<RenderQueueItem> = app.session.project.render_queue.clone();
+    let progress = app.session.render_progress();
+    let rendering = app.session.is_rendering();
+    let available = app.session.exporter.as_ref().map(|e| e.formats()).unwrap_or_default();
+    let mut actions: Vec<Action> = Vec::new();
+    let rq = RqView { queue: &queue, progress: progress.as_ref(), rendering, available: &available };
+    app.auto.add("renderQueue.drop", rect, "Drop compositions to queue");
+    queue_drop(app, ui, rect, &p, rendering, &mut actions);
+    let mut forms: Vec<(RenderQueueItem, String)> = Vec::new();
+    let state_id = egui::Id::unique("rq-ui");
+    let (mut open, mut selected): (Vec<u64>, Option<u64>) = ui.data(|d| d.get_temp(state_id).unwrap_or_default());
+
+    // ---------------------------------------------------------- Current Render strip
+    let top = Rect::from_min_size(rect.min, vec2(rect.width(), TOP_H));
+    p.rect_filled(top, 0.0, t.tl_ruler_bg);
+    current_render_strip(app, ui, &p, top, &rq, &mut actions);
 
     // ---------------------------------------------------------- column header
     let head = Rect::from_min_size(pos2(rect.min.x, top.max.y), vec2(rect.width(), HEAD_H));
@@ -575,25 +764,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             selected = Some(it.id);
             app.ui.focused = crate::dock::PanelKind::RenderQueue;
         }
-        let item_id = it.id;
-        crate::widgets::context_menu(&row_resp, |ui| {
-            if ui.button(tr("Duplicate")).clicked() {
-                actions.push(("renderQueue.duplicate", json!({"item": item_id})));
-                ui.close();
-            }
-            if ui.button(tr("Remove")).clicked() {
-                actions.push(("renderQueue.remove", json!({"item": item_id})));
-                ui.close();
-            }
-            if k > 0 && ui.button(tr("Move Up")).clicked() {
-                actions.push(("renderQueue.move", json!({"item": item_id, "to": n - 1})));
-                ui.close();
-            }
-            if n < queue.len() && ui.button(tr("Move Down")).clicked() {
-                actions.push(("renderQueue.move", json!({"item": item_id, "to": n + 1})));
-                ui.close();
-            }
-        });
+        crate::widgets::context_menu(&row_resp, |ui| row_menu(ui, &mut actions, it.id, k, queue.len()));
         app.auto.add(&aid("row"), row, &format!("#{n}"));
         let is_open = open.contains(&it.id);
         let tw = Rect::from_center_size(pos2(cx_twirl + 8.0, row.center().y), vec2(14.0, 14.0));
@@ -686,78 +857,10 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                     );
                     lp.text(pos2(dd.max.x + 14.0, r.center().y), Align2::LEFT_CENTER, info, Tokens::ui(11.0), t.text_faint);
                 }
-                // Log: Errors Only / Plus Settings / Plus Per Frame Info.
-                let ld = Rect::from_min_size(pos2(r.max.x - 190.0, r.min.y + 3.0), vec2(150.0, ROW_H - 6.0));
-                lp.text(pos2(ld.min.x - 6.0, r.center().y), Align2::RIGHT_CENTER, tr("Log:"), Tokens::ui(11.5), t.text_dim);
-                let lid = egui::Id::unique(("rq-log", it.id));
-                if widgets::dropdown(ui, ld, it.log.label(), &t, lid).clicked() && !rendering {
-                    widgets::open_popup(ui, lid);
-                }
-                let llabels: Vec<String> = RenderLog::ALL.iter().map(|l| mark(it.log == *l, l.label())).collect();
-                if let Some(i) = widgets::popup_menu(ui, lid, ld.left_bottom(), &llabels, None) {
-                    actions.push(("renderQueue.setLog", json!({"item": it.id, "log": RenderLog::ALL[i].label()})));
-                }
-                app.auto.add(&aid("log"), ld, it.log.label());
+                log_dropdown(app, ui, &ItemRow { lp: &lp, list, r, n, rendering }, it, &mut actions);
                 continue;
             }
-            // Output To.
-            let ox = dd.max.x + 14.0;
-            lp.text(pos2(ox, r.center().y), Align2::LEFT_CENTER, tr("Output To:"), Tokens::ui(11.5), t.text_dim);
-            let odd = Rect::from_min_size(pos2(ox + 62.0, r.min.y + 3.0), vec2(22.0, ROW_H - 6.0));
-            let oid = egui::Id::unique(("rq-out", it.id));
-            if widgets::dropdown(ui, odd, "", &t, oid).clicked() && !rendering {
-                widgets::open_popup(ui, oid);
-            }
-            app.auto.add(&aid("outputTo"), odd, "Output To");
-            let omenu = output_to_menu(it);
-            let olabels: Vec<String> = omenu.iter().map(|(l, _)| l.clone()).collect();
-            if let Some(i) = widgets::popup_menu(ui, oid, odd.left_bottom(), &olabels, None) {
-                if omenu[i].1.get("choose").is_some() {
-                    match pick_output(app, it) {
-                        Some(Some(path)) => actions.push(("renderQueue.setOutput", json!({"item": it.id, "path": path}))),
-                        Some(None) => {}
-                        None => editing = Some((it.id, it.output.output.clone())),
-                    }
-                } else {
-                    let mut params = omenu[i].1.clone();
-                    params["item"] = json!(it.id);
-                    actions.push(("renderQueue.setOutput", params));
-                }
-            }
-            let path_rect = Rect::from_min_max(pos2(odd.max.x + 6.0, r.min.y + 2.0), pos2(r.max.x - 8.0, r.max.y - 2.0));
-            if editing.as_ref().is_some_and(|(id, _)| *id == it.id) {
-                let mut buf = editing.as_ref().map(|(_, b)| b.clone()).unwrap_or_default();
-                let mut child = ui.new_child(egui::UiBuilder::new().max_rect(path_rect));
-                let resp = child.add(egui::TextEdit::singleline(&mut buf).desired_width(path_rect.width()).font(Tokens::ui(11.5)));
-                if resp.lost_focus() {
-                    if ui.input(|i| i.key_pressed(egui::Key::Enter)) && !buf.trim().is_empty() {
-                        actions.push(("renderQueue.setOutput", json!({"item": it.id, "path": buf.trim()})));
-                    }
-                    editing = None;
-                } else {
-                    widgets::keep_focus(ui.ctx(), &resp, &buf);
-                    editing = Some((it.id, buf));
-                }
-            } else {
-                let shown = app.session.resolve_output(it).unwrap_or_else(|| "Not yet specified".into());
-                let resp = ui.interact(path_rect, egui::Id::unique(("rq-path", it.id)), Sense::click());
-                let col = if resp.hovered() { t.accent_hover } else { t.hot_text };
-                lp.with_clip_rect(path_rect.intersect(list)).text(pos2(path_rect.min.x, r.center().y), Align2::LEFT_CENTER, &shown, Tokens::ui(11.5), col);
-                // Clicking the file name opens the save dialog (Output Movie To); Alt-click, or a
-                // host without one, edits the name template in place.
-                let dialog = app.hooks.pick_save_file.is_some();
-                if resp.clicked() && !rendering {
-                    let picked = if ui.input(|i| i.modifiers.alt) { None } else { pick_output(app, it) };
-                    match picked {
-                        Some(Some(path)) => actions.push(("renderQueue.setOutput", json!({"item": it.id, "path": path}))),
-                        Some(None) => {}
-                        None => editing = Some((it.id, it.output.output.clone())),
-                    }
-                }
-                let how = if dialog { "Click to choose where to save; Alt-click to edit the template" } else { "Click to edit" };
-                resp.on_hover_text(tr_args("Template: {}\n{}", &[&it.output.output, &how]));
-                app.auto.add(&aid("outputPath"), path_rect, &shown);
-            }
+            output_to(app, ui, &ItemRow { lp: &lp, list, r, n, rendering }, it, dd.max.x, &mut editing, &mut actions);
         }
     }
     ui.set_clip_rect(panel_clip);
@@ -770,40 +873,10 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         None => d.remove::<(u64, String)>(editing_id),
     });
 
-    // Delete removes the selected item when the panel has focus.
-    if app.ui.focused == crate::dock::PanelKind::RenderQueue
-        && editing.is_none()
-        && !rendering
-        && let Some(id) = selected
-        && app.dialog.is_none()
-        && ui.input(|i| i.key_pressed(egui::Key::Delete) || i.key_pressed(egui::Key::Backspace))
-        && !ui.ctx().egui_wants_keyboard_input()
-    {
-        actions.push(("renderQueue.remove", json!({"item": id})));
-        selected = None;
-    }
+    delete_selected(app, ui, editing.is_none() && !rendering, &mut selected, &mut actions);
 
     // ---------------------------------------------------------- footer
-    let foot = Rect::from_min_max(pos2(rect.min.x, rect.max.y - FOOT_H), rect.max);
-    p.rect_filled(foot, 0.0, t.tl_ruler_bg);
-    p.line_segment([foot.left_top(), foot.right_top()], Stroke::new(1.0, t.separator));
-    let msg = match &progress {
-        Some(pr) if rendering => format!("Message: Rendering {} of {}", (pr.items_done + 1).min(pr.items_total), pr.items_total),
-        _ => {
-            let done = queue.iter().filter(|i| i.status == RenderStatus::Done).count();
-            format!("Message: {done} of {} done", queue.len())
-        }
-    };
-    p.text(pos2(foot.min.x + 12.0, foot.center().y), Align2::LEFT_CENTER, msg, Tokens::ui(11.0), t.text_dim);
-    let started = queue.iter().filter(|i| i.started.is_some()).count();
-    let total: f64 = queue.iter().filter_map(|i| i.render_time).sum();
-    p.text(
-        pos2(foot.max.x - 12.0, foot.center().y),
-        Align2::RIGHT_CENTER,
-        format!("Renders Started: {started}     Total Time Elapsed: {}", hms(progress.as_ref().filter(|_| rendering).map(|p| p.elapsed).unwrap_or(total))),
-        Tokens::ui(11.0),
-        t.text_dim,
-    );
+    footer(&p, rect, &rq, &t);
 
     open.retain(|id| queue.iter().any(|i| i.id == *id));
     ui.data_mut(|d| d.insert_temp(state_id, (open, selected)));
diff --git a/crates/ui-egui/src/panels/roto_tool.rs b/crates/ui-egui/src/panels/roto_tool.rs
index 52175899c..0d9eefe45 100644
--- a/crates/ui-egui/src/panels/roto_tool.rs
+++ b/crates/ui-egui/src/panels/roto_tool.rs
@@ -135,17 +135,15 @@ pub fn draw_overlay(
     }
 }
 
+/// The layer <-> screen mappings [`interact`] works with.
+pub struct LayerXform<'a> {
+    pub to_screen: &'a dyn Fn([f64; 2]) -> Pos2,
+    pub to_layer: &'a dyn Fn(Pos2) -> [f64; 2],
+}
+
 /// Pointer handling for the Roto Brush / Refine Edge tools. Returns true when it handled input.
-pub fn interact(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    painter: &egui::Painter,
-    area: Rect,
-    layer: &Layer,
-    zoom: f64,
-    to_screen: &dyn Fn([f64; 2]) -> Pos2,
-    to_layer: &dyn Fn(Pos2) -> [f64; 2],
-) -> bool {
+pub fn interact(app: &mut EffectcraftApp, ui: &mut egui::Ui, painter: &egui::Painter, area: Rect, layer: &Layer, zoom: f64, xf: LayerXform) -> bool {
+    let LayerXform { to_screen, to_layer } = xf;
     let ctx = ui.ctx().clone();
     let mods = ui.input(|i| i.modifiers);
     let Some(kind) = app.ui.tool.roto_kind(mods.alt) else { return false };
diff --git a/crates/ui-egui/src/panels/rq_templates.rs b/crates/ui-egui/src/panels/rq_templates.rs
index b10381629..753dea50d 100644
--- a/crates/ui-egui/src/panels/rq_templates.rs
+++ b/crates/ui-egui/src/panels/rq_templates.rs
@@ -60,7 +60,7 @@ pub fn show(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
                 ui.label(slot.label());
                 let cur = templates.default_name(k, slot);
                 let mut pick = cur.clone();
-                let r = egui::ComboBox::from_id_salt(("tpl-def", slot.label())).selected_text(&cur).width(300.0).show_ui(ui, |ui| {
+                let r = craft_ui::ComboBox::from_id_salt(("tpl-def", slot.label())).selected_text(&cur).width(300.0).show_ui(ui, |ui| {
                     for n in &list {
                         ui.selectable_value(&mut pick, n.clone(), n);
                     }
@@ -77,7 +77,7 @@ pub fn show(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
         ui.label(egui::RichText::new(tr("Settings")).font(Tokens::semibold(12.5)).color(t.text));
         ui.horizontal(|ui| {
             ui.label(tr("Settings Name:"));
-            let r = egui::ComboBox::from_id_salt("tpl-select").selected_text(&st.selected).width(300.0).show_ui(ui, |ui| {
+            let r = craft_ui::ComboBox::from_id_salt("tpl-select").selected_text(&st.selected).width(300.0).show_ui(ui, |ui| {
                 for n in &list {
                     ui.selectable_value(&mut st.selected, n.clone(), n);
                 }
diff --git a/crates/ui-egui/src/panels/scriptui_view.rs b/crates/ui-egui/src/panels/scriptui_view.rs
index 40096c8c9..242626272 100644
--- a/crates/ui-egui/src/panels/scriptui_view.rs
+++ b/crates/ui-egui/src/panels/scriptui_view.rs
@@ -214,7 +214,7 @@ fn draw_widget(app: &mut EffectcraftApp, ui: &mut egui::Ui, origin: egui::Pos2,
             let mut pick: Option<usize> = None;
             ui.add_enabled_ui(w.enabled, |ui| {
                 ui.scope_builder(UiBuilder::new().max_rect(rect), |ui| {
-                    egui::ComboBox::from_id_salt(id).selected_text(cur).width(rect.width() - 8.0).show_ui(ui, |ui| {
+                    craft_ui::ComboBox::from_id_salt(id).selected_text(cur).width(rect.width() - 8.0).show_ui(ui, |ui| {
                         for (i, it) in w.items.iter().enumerate() {
                             if it == "-" {
                                 ui.separator();
diff --git a/crates/ui-egui/src/panels/settings.rs b/crates/ui-egui/src/panels/settings.rs
index a60272b4b..692f48236 100644
--- a/crates/ui-egui/src/panels/settings.rs
+++ b/crates/ui-egui/src/panels/settings.rs
@@ -78,7 +78,7 @@ fn page_ui(app: &mut EffectcraftApp, ui: &mut egui::Ui, page: &Page, cur: &Value
                 ui.horizontal(|ui| {
                     ui.add_sized(vec2(label_w, 18.0), egui::Label::new(tr("Default Output:")));
                     let shown = if sel.is_empty() { tr("System Default").to_string() } else { sel.clone() };
-                    let r = egui::ComboBox::from_id_salt(("settings", key)).selected_text(shown).width(260.0).show_ui(ui, |ui| {
+                    let r = craft_ui::ComboBox::from_id_salt(("settings", key)).selected_text(shown).width(260.0).show_ui(ui, |ui| {
                         if ui.selectable_label(sel.is_empty(), tr("System Default")).clicked() {
                             acts.push(Act::Set(key.into(), json!("")));
                         }
@@ -157,7 +157,7 @@ fn page_ui(app: &mut EffectcraftApp, ui: &mut egui::Ui, page: &Page, cur: &Value
                                 Kind::Choice(opts) => {
                                     let curv = v.as_str().map_or_else(|| v.to_string(), str::to_string);
                                     let shown = opts.iter().find(|o| o.1 == curv).map(|o| o.0).unwrap_or(curv.as_str()).to_string();
-                                    egui::ComboBox::from_id_salt(("settings", key))
+                                    craft_ui::ComboBox::from_id_salt(("settings", key))
                                         .selected_text(tr(&shown))
                                         .width(220.0)
                                         .show_ui(ui, |ui| {
@@ -302,19 +302,20 @@ fn theme_preview(ui: &mut egui::Ui, kind: ThemeKind, width: f32) {
     painter.line_segment([pos2(cti, graph.top()), pos2(cti, graph.bottom())], egui::Stroke::new(1.0, p.cti));
 }
 
+/// What [`theme_card`] shows: the setting `key`, the translated `title`, whether the family is
+/// `active`, the `cur`rent theme and the `options` (value, label) to pick from.
+struct ThemeFamily<'a> {
+    key: &'a str,
+    title: &'a str,
+    active: bool,
+    cur: &'a str,
+    options: &'a [(&'a str, &'a str)],
+}
+
 /// One theme family's card: its (translated) name, Active when the appearance shows it now, a preview of the
 /// chosen theme and a radio button per theme.
-fn theme_card(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    t: &Tokens,
-    key: &str,
-    title: &str,
-    active: bool,
-    cur: &str,
-    options: &[(&str, &str)],
-    acts: &mut Vec<Act>,
-) {
+fn theme_card(app: &mut EffectcraftApp, ui: &mut egui::Ui, t: &Tokens, fam: ThemeFamily, acts: &mut Vec<Act>) {
+    let ThemeFamily { key, title, active, cur, options } = fam;
     egui::Frame::new()
         .fill(t.field_bg)
         .stroke(egui::Stroke::new(1.0, if active { t.accent } else { t.field_border }))
@@ -378,7 +379,7 @@ fn appearance_ui(app: &mut EffectcraftApp, ui: &mut egui::Ui, cur: &Value, t: &T
     ui.horizontal(|ui| {
         ui.add_sized(vec2(250.0, 18.0), egui::Label::new(format!("{}:", tr("Appearance Mode"))).truncate());
         let shown = APPEARANCE_MODES.iter().find(|(_, v)| *v == mode).map_or(mode.as_str(), |(l, _)| *l);
-        let r = egui::ComboBox::from_id_salt(("settings", "appearance.appearanceMode"))
+        let r = craft_ui::ComboBox::from_id_salt(("settings", "appearance.appearanceMode"))
             .selected_text(tr(shown))
             .width(220.0)
             .show_ui(ui, |ui| {
@@ -396,8 +397,20 @@ fn appearance_ui(app: &mut EffectcraftApp, ui: &mut egui::Ui, cur: &Value, t: &T
     let light_active = mode == "light" || (mode == "auto" && system_light == Some(true));
     ui.columns(2, |cols| {
         let [l, d] = cols else { return };
-        theme_card(app, l, t, "appearance.lightTheme", tr("Light Theme"), light_active, &light, LIGHT_THEMES, acts);
-        theme_card(app, d, t, "appearance.darkTheme", tr("Dark Theme"), !light_active, &dark, DARK_THEMES, acts);
+        theme_card(
+            app,
+            l,
+            t,
+            ThemeFamily { key: "appearance.lightTheme", title: tr("Light Theme"), active: light_active, cur: &light, options: LIGHT_THEMES },
+            acts,
+        );
+        theme_card(
+            app,
+            d,
+            t,
+            ThemeFamily { key: "appearance.darkTheme", title: tr("Dark Theme"), active: !light_active, cur: &dark, options: DARK_THEMES },
+            acts,
+        );
     });
     ui.add_space(6.0);
 }
diff --git a/crates/ui-egui/src/panels/shortcut_editor.rs b/crates/ui-egui/src/panels/shortcut_editor.rs
index 29bae6c7e..2721c6750 100644
--- a/crates/ui-egui/src/panels/shortcut_editor.rs
+++ b/crates/ui-egui/src/panels/shortcut_editor.rs
@@ -264,7 +264,7 @@ pub fn show(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
         // ---- preset bar
         ui.horizontal(|ui| {
             ui.label(tr("Preset:"));
-            let r = egui::ComboBox::from_id_salt("sc-preset").selected_text(&active).width(220.0).show_ui(ui, |ui| {
+            let r = craft_ui::ComboBox::from_id_salt("sc-preset").selected_text(&active).width(220.0).show_ui(ui, |ui| {
                 for n in &presets {
                     if ui.selectable_label(*n == active, n).clicked() {
                         run.push(("shortcuts.preset".into(), json!({"op": "select", "name": n})));
diff --git a/crates/ui-egui/src/panels/text_panels.rs b/crates/ui-egui/src/panels/text_panels.rs
index c4e8a2b0b..8a8e604e2 100644
--- a/crates/ui-egui/src/panels/text_panels.rs
+++ b/crates/ui-egui/src/panels/text_panels.rs
@@ -64,7 +64,8 @@ pub fn text_target(app: &EffectcraftApp) -> Option<TextTarget> {
 /// A small toggle button at `r` showing `label` (semibold 13 when `bold`, else 12), filled with
 /// the accent while `on`; returns whether it was clicked. It only reports the click: the caller
 /// decides the new state.
-fn toggle(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, r: Rect, id: &str, label: &str, on: bool, bold: bool) -> bool {
+fn toggle(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, r: Rect, id: &str, look: (&str, bool, bool)) -> bool {
+    let (label, on, bold) = look;
     let t = app.tokens;
     let resp = ui.interact(r, egui::Id::unique(("text-toggle", id)), Sense::click());
     p.rect_filled(
@@ -84,6 +85,103 @@ fn toggle(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, r: Rec
     resp.clicked()
 }
 
+/// Position of the numeric grid (`x0`, top `y`, width `w`) and whether edits are collected.
+#[derive(Clone, Copy)]
+struct Grid {
+    x0: f32,
+    y: f32,
+    w: f32,
+    enabled: bool,
+}
+
+/// Numeric fields in AE's two-column grid (Kerning is a popup, at row 1 left).
+fn numeric_fields(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, g: Grid, doc: &TextDoc, actions: &mut Vec<serde_json::Value>) {
+    let t = app.tokens;
+    let Grid { x0, y, w, enabled } = g;
+    let fields: [(&str, &str, f64, (f64, f64), &str); 10] = [
+        ("size", "T", doc.size, (1.0, 2000.0), " px"),
+        ("leading", "A", doc.leading.unwrap_or(doc.size * 1.2), (0.0, 5000.0), " px"),
+        ("", "", 0.0, (0.0, 0.0), ""),
+        ("tracking", "VA", doc.tracking, (-1000.0, 10000.0), ""),
+        ("strokeWidth", "W", doc.stroke_width, (0.0, 500.0), " px"),
+        ("", "", 0.0, (0.0, 0.0), ""),
+        ("vScale", "↕T", doc.v_scale, (1.0, 1000.0), " %"),
+        ("hScale", "↔T", doc.h_scale, (1.0, 1000.0), " %"),
+        ("baselineShift", "A↑", doc.baseline_shift, (-1000.0, 1000.0), " px"),
+        ("tsume", "Ts", doc.tsume, (0.0, 100.0), " %"),
+    ];
+    for (i, (key, glyph, v, range, suffix)) in fields.into_iter().enumerate() {
+        if key.is_empty() {
+            continue;
+        }
+        let col = i % 2;
+        let row = i / 2;
+        let fx = x0 + col as f32 * (w / 2.0);
+        let fy = y + row as f32 * 28.0;
+        p.text(pos2(fx, fy + 9.0), Align2::LEFT_CENTER, glyph, Tokens::semibold(11.0), t.text_dim);
+        let (r, nv, _) = widgets::hot_number_at(
+            ui,
+            pos2(fx + 26.0, fy),
+            egui::Id::unique(("char", key)),
+            v,
+            &widgets::HotSpec { speed: 0.5, range, decimals: 0, suffix },
+            &t,
+        );
+        app.auto.add(&format!("character.{key}"), r, key);
+        if let Some(nv) = nv
+            && enabled
+        {
+            actions.push(json!({key: nv, "merge": format!("char-{key}")}));
+        }
+    }
+}
+
+/// Kerning: Metrics / Optical / a manual value (grid row 1, left).
+fn kerning_field(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, g: Grid, doc: &TextDoc, actions: &mut Vec<serde_json::Value>) {
+    let t = app.tokens;
+    let Grid { x0, y, w, enabled } = g;
+    let fy = y + 28.0;
+    p.text(pos2(x0, fy + 9.0), Align2::LEFT_CENTER, "V/A", Tokens::semibold(11.0), t.text_dim);
+    let label = match doc.kerning {
+        Kerning::Metrics => "Metrics".to_string(),
+        Kerning::Optical => "Optical".to_string(),
+        Kerning::Manual(v) => format!("{v:.0}"),
+    };
+    let kr = Rect::from_min_size(pos2(x0 + 26.0, fy), vec2((w / 2.0 - 32.0).max(50.0), 20.0));
+    let kpop = egui::Id::unique("char-kerning-pop");
+    if widgets::dropdown(ui, kr, &label, &t, egui::Id::unique("char-kerning")).clicked() && enabled {
+        widgets::open_popup(ui, kpop);
+    }
+    app.auto.add("character.kerning", kr, "Kerning");
+    let opts: Vec<String> = ["Metrics", "Optical", "0", "-50", "-25", "-10", "10", "25", "50", "100"].iter().map(|s| s.to_string()).collect();
+    if let Some(i) = widgets::popup_menu(ui, kpop, kr.left_bottom(), &opts, None) {
+        let v = match i {
+            0 => json!("metrics"),
+            1 => json!("optical"),
+            _ => json!(opts[i].parse::<f64>().unwrap_or(0.0)),
+        };
+        actions.push(json!({"kerning": v}));
+    }
+}
+
+/// Stroke Over Fill / Fill Over Stroke (grid row 2, right).
+fn stroke_order_field(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: Grid, doc: &TextDoc, actions: &mut Vec<serde_json::Value>) {
+    let t = app.tokens;
+    let Grid { x0, y, w, enabled } = g;
+    let fx = x0 + w / 2.0;
+    let fy = y + 2.0 * 28.0;
+    let dr = Rect::from_min_size(pos2(fx, fy), vec2(w / 2.0, 20.0));
+    let labels = vec!["Fill Over Stroke".to_string(), "Stroke Over Fill".to_string()];
+    let pop = egui::Id::unique("char-stroke-order-pop");
+    if widgets::dropdown(ui, dr, &labels[doc.stroke_over_fill as usize], &t, egui::Id::unique("char-stroke-order")).clicked() && enabled {
+        widgets::open_popup(ui, pop);
+    }
+    app.auto.add("character.strokeOverFill", dr, "Stroke order");
+    if let Some(i) = widgets::popup_menu(ui, pop, dr.left_bottom(), &labels, Some(doc.stroke_over_fill as usize)) {
+        actions.push(json!({"strokeOverFill": i == 1}));
+    }
+}
+
 /// The Character panel for the text being edited (or the selected text layer): font family and
 /// style, size, leading, tracking, stroke, scale, baseline shift and other numeric fields, kerning,
 /// fill/stroke colours with eyedroppers, style toggles, OpenType features and variable-font axes.
@@ -122,76 +220,10 @@ pub fn character(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         actions.push(json!({"style": st}));
     }
     y += 34.0;
-    // Numeric fields in AE's two-column grid (Kerning is a popup, at row 1 right).
-    let fields: [(&str, &str, f64, (f64, f64), &str); 10] = [
-        ("size", "T", doc.size, (1.0, 2000.0), " px"),
-        ("leading", "A", doc.leading.unwrap_or(doc.size * 1.2), (0.0, 5000.0), " px"),
-        ("", "", 0.0, (0.0, 0.0), ""),
-        ("tracking", "VA", doc.tracking, (-1000.0, 10000.0), ""),
-        ("strokeWidth", "W", doc.stroke_width, (0.0, 500.0), " px"),
-        ("", "", 0.0, (0.0, 0.0), ""),
-        ("vScale", "↕T", doc.v_scale, (1.0, 1000.0), " %"),
-        ("hScale", "↔T", doc.h_scale, (1.0, 1000.0), " %"),
-        ("baselineShift", "A↑", doc.baseline_shift, (-1000.0, 1000.0), " px"),
-        ("tsume", "Ts", doc.tsume, (0.0, 100.0), " %"),
-    ];
-    for (i, (key, glyph, v, range, suffix)) in fields.into_iter().enumerate() {
-        if key.is_empty() {
-            continue;
-        }
-        let col = i % 2;
-        let row = i / 2;
-        let fx = x0 + col as f32 * (w / 2.0);
-        let fy = y + row as f32 * 28.0;
-        p.text(pos2(fx, fy + 9.0), Align2::LEFT_CENTER, glyph, Tokens::semibold(11.0), t.text_dim);
-        let (r, nv, _) = widgets::hot_number_at(ui, pos2(fx + 26.0, fy), egui::Id::unique(("char", key)), v, 0.5, range, 0, suffix, &t);
-        app.auto.add(&format!("character.{key}"), r, key);
-        if let Some(nv) = nv
-            && enabled
-        {
-            actions.push(json!({key: nv, "merge": format!("char-{key}")}));
-        }
-    }
-    // Kerning: Metrics / Optical / a manual value (row 1, left).
-    {
-        let fy = y + 28.0;
-        p.text(pos2(x0, fy + 9.0), Align2::LEFT_CENTER, "V/A", Tokens::semibold(11.0), t.text_dim);
-        let label = match doc.kerning {
-            Kerning::Metrics => "Metrics".to_string(),
-            Kerning::Optical => "Optical".to_string(),
-            Kerning::Manual(v) => format!("{v:.0}"),
-        };
-        let kr = Rect::from_min_size(pos2(x0 + 26.0, fy), vec2((w / 2.0 - 32.0).max(50.0), 20.0));
-        let kpop = egui::Id::unique("char-kerning-pop");
-        if widgets::dropdown(ui, kr, &label, &t, egui::Id::unique("char-kerning")).clicked() && enabled {
-            widgets::open_popup(ui, kpop);
-        }
-        app.auto.add("character.kerning", kr, "Kerning");
-        let opts: Vec<String> = ["Metrics", "Optical", "0", "-50", "-25", "-10", "10", "25", "50", "100"].iter().map(|s| s.to_string()).collect();
-        if let Some(i) = widgets::popup_menu(ui, kpop, kr.left_bottom(), &opts, None) {
-            let v = match i {
-                0 => json!("metrics"),
-                1 => json!("optical"),
-                _ => json!(opts[i].parse::<f64>().unwrap_or(0.0)),
-            };
-            actions.push(json!({"kerning": v}));
-        }
-    }
-    // Stroke Over Fill / Fill Over Stroke (row 2, right).
-    {
-        let fx = x0 + w / 2.0;
-        let fy = y + 2.0 * 28.0;
-        let dr = Rect::from_min_size(pos2(fx, fy), vec2(w / 2.0, 20.0));
-        let labels = vec!["Fill Over Stroke".to_string(), "Stroke Over Fill".to_string()];
-        let pop = egui::Id::unique("char-stroke-order-pop");
-        if widgets::dropdown(ui, dr, &labels[doc.stroke_over_fill as usize], &t, egui::Id::unique("char-stroke-order")).clicked() && enabled {
-            widgets::open_popup(ui, pop);
-        }
-        app.auto.add("character.strokeOverFill", dr, "Stroke order");
-        if let Some(i) = widgets::popup_menu(ui, pop, dr.left_bottom(), &labels, Some(doc.stroke_over_fill as usize)) {
-            actions.push(json!({"strokeOverFill": i == 1}));
-        }
-    }
+    let grid = Grid { x0, y, w, enabled };
+    numeric_fields(app, ui, &p, grid, &doc, &mut actions);
+    kerning_field(app, ui, &p, grid, &doc, &mut actions);
+    stroke_order_field(app, ui, grid, &doc, &mut actions);
     y += 5.0 * 28.0 + 8.0;
     // Fill / stroke swatches with their enable boxes.
     for (i, (key, label, on, c)) in [("fill", "Fill", doc.apply_fill, doc.fill), ("stroke", "Stroke", doc.apply_stroke, doc.stroke)].into_iter().enumerate() {
@@ -242,7 +274,7 @@ pub fn character(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let bw = ((w - 5.0 * 4.0) / 6.0).clamp(22.0, 30.0);
     for (i, (key, label, on, bold)) in toggles.into_iter().enumerate() {
         let r = Rect::from_min_size(pos2(x0 + i as f32 * (bw + 4.0), y), vec2(bw, 24.0));
-        if toggle(app, ui, &p, r, &format!("character.{key}"), label, on, bold) && enabled {
+        if toggle(app, ui, &p, r, &format!("character.{key}"), (label, on, bold)) && enabled {
             actions.push(json!({key: !on}));
         }
     }
@@ -296,8 +328,14 @@ pub fn character(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             let tag = a.tag.trim_end().to_string();
             let v = doc.variations.iter().chain(&instance).find(|(t2, _)| t2.trim_end() == tag).map(|(_, v)| *v).unwrap_or(a.default);
             p.text(pos2(fx, fy + 9.0), Align2::LEFT_CENTER, &tag, Tokens::semibold(10.5), t.text_dim);
-            let (r, nv, _) =
-                widgets::hot_number_at(ui, pos2(fx + 34.0, fy), egui::Id::unique(("char-axis", &tag)), v as f64, 1.0, (a.min as f64, a.max as f64), 0, "", &t);
+            let (r, nv, _) = widgets::hot_number_at(
+                ui,
+                pos2(fx + 34.0, fy),
+                egui::Id::unique(("char-axis", &tag)),
+                v as f64,
+                &widgets::HotSpec { speed: 1.0, range: (a.min as f64, a.max as f64), decimals: 0, suffix: "" },
+                &t,
+            );
             app.auto.add(&format!("character.axis.{tag}"), r, &a.name);
             if let Some(nv) = nv
                 && enabled
@@ -517,7 +555,14 @@ pub fn paragraph(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         let fx = x0 + (i % 2) as f32 * (w / 2.0);
         let fy = y + (i / 2) as f32 * 28.0;
         p.text(pos2(fx, fy + 9.0), Align2::LEFT_CENTER, glyph, Tokens::semibold(11.0), t.text_dim);
-        let (r, nv, _) = widgets::hot_number_at(ui, pos2(fx + 26.0, fy), egui::Id::unique(("para-f", key)), v, 0.5, (-5000.0, 5000.0), 0, " px", &t);
+        let (r, nv, _) = widgets::hot_number_at(
+            ui,
+            pos2(fx + 26.0, fy),
+            egui::Id::unique(("para-f", key)),
+            v,
+            &widgets::HotSpec { speed: 0.5, range: (-5000.0, 5000.0), decimals: 0, suffix: " px" },
+            &t,
+        );
         app.auto.add(&format!("paragraph.{key}"), r, key);
         if let Some(nv) = nv
             && enabled
@@ -635,130 +680,131 @@ pub(super) fn font_picker(app: &mut EffectcraftApp, ui: &mut egui::Ui, id: egui:
         return None;
     }
     app.auto.add(&format!("{auto}.toggle"), arrow, "Close font list");
-    let mut chosen = None;
-    let screen = ui.ctx().content_rect();
-    let below = screen.bottom() - rect.bottom() - 16.0;
-    let above = below < 100.0 && rect.top() - screen.top() > below;
-    let max_height = (if above { rect.top() - screen.top() - 16.0 } else { below }).clamp(28.0, 380.0);
-    let anchor = if above { rect.left_top() } else { rect.left_bottom() };
-    let pivot = if above { Align2::LEFT_BOTTOM } else { Align2::LEFT_TOP };
     widgets::note_open_popup_list(ui.ctx());
-    let area = egui::Area::new(id.with("area")).order(egui::Order::Foreground).pivot(pivot).fixed_pos(anchor).show(ui.ctx(), |ui| {
-        egui::Frame::popup(ui.style()).show(ui, |ui| {
-            ui.set_width(rect.width().max(180.0));
-            // Filter row: a checkbox that keeps only the variable fonts.
-            let filter_h = 22.0;
-            let row = ui.add_sized([ui.available_width(), filter_h], egui::Button::selectable(false, ""));
-            let box_rect = Rect::from_min_size(row.rect.min, vec2(18.0, filter_h));
-            let label_rect = Rect::from_min_max(pos2(box_rect.max.x + 2.0, row.rect.min.y), row.rect.max);
-            let boxed = widgets::checkbox(ui, box_rect, only_variable, &t, id.with("variable-check"));
-            ui.painter().text(label_rect.left_center(), Align2::LEFT_CENTER, tr("Variable fonts only"), Tokens::ui(11.5), t.text);
-            app.auto.add(&format!("{auto}.variable"), row.rect, "Variable fonts only");
-            let toggled = row.clicked() || boxed.clicked();
-            if toggled {
-                only_variable = !only_variable;
-                ui.data_mut(|d| d.insert_temp(variable_id, only_variable));
-                // Typing goes on into the search field.
-                ui.memory_mut(|m| m.request_focus(search_id));
+    let changed = search.changed();
+    let mut open = true;
+    // The search lives in the field; the menu's header is the filter row, its list the fonts.
+    let menu = craft_ui::combo::Menu::new(ui, &search)
+        .open(&mut open)
+        .height(380.0)
+        .close_behavior(egui::PopupCloseBehavior::CloseOnClickOutside)
+        .style(egui::style::StyleModifier::default());
+    let app_ref = &mut *app;
+    let header = |ui: &mut egui::Ui| {
+        ui.set_width(rect.width().max(180.0));
+        // Filter row: a checkbox that keeps only the variable fonts.
+        let filter_h = 22.0;
+        let row = ui.add_sized([ui.available_width(), filter_h], egui::Button::selectable(false, ""));
+        let box_rect = Rect::from_min_size(row.rect.min, vec2(18.0, filter_h));
+        let label_rect = Rect::from_min_max(pos2(box_rect.max.x + 2.0, row.rect.min.y), row.rect.max);
+        let boxed = widgets::checkbox(ui, box_rect, only_variable, &t, id.with("variable-check"));
+        ui.painter().text(label_rect.left_center(), Align2::LEFT_CENTER, tr("Variable fonts only"), Tokens::ui(11.5), t.text);
+        app_ref.auto.add(&format!("{auto}.variable"), row.rect, "Variable fonts only");
+        let toggled = row.clicked() || boxed.clicked();
+        if toggled {
+            only_variable = !only_variable;
+            ui.data_mut(|d| d.insert_temp(variable_id, only_variable));
+            // Typing goes on into the search field.
+            ui.memory_mut(|m| m.request_focus(search_id));
+        }
+        let query = state.query.trim().to_lowercase();
+        let mut seen = std::collections::HashSet::new();
+        let filtered: Vec<_> = rows
+            .iter()
+            .filter(|r| {
+                !r.family.is_empty()
+                    && (!only_variable || r.variable)
+                    && (query.is_empty() || ((r.family.to_lowercase().contains(&query) || r.display.to_lowercase().contains(&query)) && seen.insert(&r.family)))
+            })
+            .collect();
+        if fresh {
+            state.selected = filtered.iter().position(|r| r.family == current).unwrap_or(0);
+        }
+        if changed || toggled {
+            state.selected = 0;
+        }
+        let last = filtered.len().saturating_sub(1);
+        state.selected = state.selected.min(last);
+        if down {
+            state.selected = state.selected.saturating_add(1).min(last);
+        }
+        if up {
+            state.selected = state.selected.saturating_sub(1);
+        }
+        let entered = if enter { filtered.get(state.selected).map(|r| r.family.clone()) } else { None };
+        (app_ref, filtered, query.is_empty(), state.selected, changed || toggled, entered)
+    };
+    let list = |ui: &mut egui::Ui,
+                (app, filtered, all, selected, restart, entered): (
+        &mut EffectcraftApp,
+        Vec<&effectcraft_engine::FontRow>,
+        bool,
+        usize,
+        bool,
+        Option<String>,
+    )| {
+        if restart {
+            ui.scroll_to_cursor(Some(egui::Align::TOP));
+        }
+        let mut chosen = entered;
+        if filtered.is_empty() {
+            let r = ui.label(tr("No matching fonts"));
+            app.auto.add(&format!("{auto}.empty"), r.rect, "No matching fonts");
+        }
+        let mut was_recent = false;
+        for (index, r) in filtered.iter().enumerate() {
+            if all && was_recent && !r.recent {
+                ui.separator();
             }
-            let query = state.query.trim().to_lowercase();
-            let mut seen = std::collections::HashSet::new();
-            let filtered: Vec<_> = rows
-                .iter()
-                .filter(|r| {
-                    !r.family.is_empty()
-                        && (!only_variable || r.variable)
-                        && (query.is_empty()
-                            || ((r.family.to_lowercase().contains(&query) || r.display.to_lowercase().contains(&query)) && seen.insert(&r.family)))
-                })
-                .collect();
-            if fresh {
-                state.selected = filtered.iter().position(|r| r.family == current).unwrap_or(0);
+            was_recent = r.recent;
+            let row_width = ui.available_width();
+            let label_width = if preview { (row_width - 100.0).max(40.0) } else { row_width };
+            let resp = ui.add_sized([row_width, 24.0], egui::Button::selectable(index == selected, ""));
+            resp.widget_info(|| egui::WidgetInfo::selected(egui::Role::Button, ui.is_enabled(), index == selected, &r.display));
+            let label_rect = Rect::from_min_size(resp.rect.min + vec2(5.0, 0.0), vec2(label_width - 5.0, resp.rect.height()));
+            ui.painter().with_clip_rect(label_rect.intersect(ui.clip_rect())).text(
+                label_rect.left_center(),
+                Align2::LEFT_CENTER,
+                &r.display,
+                Tokens::ui(12.0),
+                t.text,
+            );
+            if ui.is_rect_visible(resp.rect) {
+                app.auto.add(&format!("{auto}.option.{}", r.family), resp.rect, &r.display);
             }
-            if search.changed() || toggled {
-                state.selected = 0;
+            if index == selected && (fresh || up || down) {
+                resp.scroll_to_me(None);
             }
-            let last = filtered.len().saturating_sub(1);
-            state.selected = state.selected.min(last);
-            if down {
-                state.selected = state.selected.saturating_add(1).min(last);
-            }
-            if up {
-                state.selected = state.selected.saturating_sub(1);
-            }
-            if enter {
-                chosen = filtered.get(state.selected).map(|r| r.family.clone());
-            }
-            // Give the result list its actual height even when the previous query had
-            // only one row. A cached tiny Area must not collapse a reopened long list.
-            let filter_room = filter_h + ui.spacing().item_spacing.y;
-            let height = (filtered.len() as f32 * (24.0 + ui.spacing().item_spacing.y) + 16.0).clamp(28.0, (max_height - filter_room).max(28.0));
-            // A minimum, from below the filter row (a maximum would move the cursor back up).
-            ui.set_min_height(height);
-            let mut scroll = egui::ScrollArea::vertical().id_salt(id.with("results")).max_height(height).min_scrolled_height(height);
-            if search.changed() || toggled {
-                scroll = scroll.vertical_scroll_offset(0.0);
-            }
-            scroll.show(ui, |ui| {
-                if filtered.is_empty() {
-                    let r = ui.label(tr("No matching fonts"));
-                    app.auto.add(&format!("{auto}.empty"), r.rect, "No matching fonts");
+            if preview && ui.is_rect_visible(resp.rect) {
+                let key = egui::Id::unique(("font-preview", &r.family));
+                let lines: std::sync::Arc<Vec<Vec<[f32; 2]>>> = match ui.data(|d| d.get_temp(key)) {
+                    Some(l) => l,
+                    None => {
+                        let l = std::sync::Arc::new(effectcraft_engine::font_preview(&r.family, 14.0));
+                        ui.data_mut(|d| d.insert_temp(key, l.clone()));
+                        l
+                    }
+                };
+                // Scaled and placed to fit the row's preview column, and clipped to the row (#577).
+                let room = Rect::from_min_max(pos2(resp.rect.max.x - 95.0, resp.rect.min.y + 1.0), pos2(resp.rect.max.x - 6.0, resp.rect.max.y - 1.0));
+                if let Some((k, o)) = fit_preview(&lines, room, resp.rect.center().y + 5.0) {
+                    let painter = ui.painter().with_clip_rect(resp.rect.intersect(ui.clip_rect()));
+                    for poly in lines.iter() {
+                        let pts: Vec<egui::Pos2> =
+                            poly.iter().filter(|p| p[0].is_finite() && p[1].is_finite()).map(|p| (o + vec2(p[0], p[1]) * k).to_pos2()).collect();
+                        painter.add(egui::Shape::line(pts, egui::Stroke::new(1.0, t.text_dim)));
+                    }
                 }
-                let mut was_recent = false;
-                for (index, r) in filtered.iter().enumerate() {
-                    if query.is_empty() && was_recent && !r.recent {
-                        ui.separator();
-                    }
-                    was_recent = r.recent;
-                    let row_width = ui.available_width();
-                    let label_width = if preview { (row_width - 100.0).max(40.0) } else { row_width };
-                    let resp = ui.add_sized([row_width, 24.0], egui::Button::selectable(index == state.selected, ""));
-                    resp.widget_info(|| egui::WidgetInfo::selected(egui::Role::Button, ui.is_enabled(), index == state.selected, &r.display));
-                    let label_rect = Rect::from_min_size(resp.rect.min + vec2(5.0, 0.0), vec2(label_width - 5.0, resp.rect.height()));
-                    ui.painter().with_clip_rect(label_rect.intersect(ui.clip_rect())).text(
-                        label_rect.left_center(),
-                        Align2::LEFT_CENTER,
-                        &r.display,
-                        Tokens::ui(12.0),
-                        t.text,
-                    );
-                    if ui.is_rect_visible(resp.rect) {
-                        app.auto.add(&format!("{auto}.option.{}", r.family), resp.rect, &r.display);
-                    }
-                    if index == state.selected && (fresh || up || down) {
-                        resp.scroll_to_me(None);
-                    }
-                    if preview && ui.is_rect_visible(resp.rect) {
-                        let key = egui::Id::unique(("font-preview", &r.family));
-                        let lines: std::sync::Arc<Vec<Vec<[f32; 2]>>> = match ui.data(|d| d.get_temp(key)) {
-                            Some(l) => l,
-                            None => {
-                                let l = std::sync::Arc::new(effectcraft_engine::font_preview(&r.family, 14.0));
-                                ui.data_mut(|d| d.insert_temp(key, l.clone()));
-                                l
-                            }
-                        };
-                        // Scaled and placed to fit the row's preview column, and clipped to the row (#577).
-                        let room = Rect::from_min_max(pos2(resp.rect.max.x - 95.0, resp.rect.min.y + 1.0), pos2(resp.rect.max.x - 6.0, resp.rect.max.y - 1.0));
-                        if let Some((k, o)) = fit_preview(&lines, room, resp.rect.center().y + 5.0) {
-                            let painter = ui.painter().with_clip_rect(resp.rect.intersect(ui.clip_rect()));
-                            for poly in lines.iter() {
-                                let pts: Vec<egui::Pos2> =
-                                    poly.iter().filter(|p| p[0].is_finite() && p[1].is_finite()).map(|p| (o + vec2(p[0], p[1]) * k).to_pos2()).collect();
-                                painter.add(egui::Shape::line(pts, egui::Stroke::new(1.0, t.text_dim)));
-                            }
-                        }
-                    }
-                    if resp.clicked() {
-                        chosen = Some(r.family.clone());
-                    }
-                    resp.on_hover_text(&r.display);
-                }
-            });
-        });
-    });
-    let outside = widgets::pressed_outside(ui.ctx(), &area.response) && !ui.input(|i| i.pointer.interact_pos().is_some_and(|p| rect.contains(p)));
-    if chosen.is_some() || outside || escape {
+            }
+            if resp.clicked() {
+                chosen = Some(r.family.clone());
+            }
+            resp.on_hover_text(&r.display);
+        }
+        chosen
+    };
+    let chosen = menu.show_ui_with_header(header, list).flatten();
+    if chosen.is_some() || !open || escape {
         ui.data_mut(|d| {
             d.insert_temp(id.with("open"), false);
             d.remove::<FontSearch>(state_id);
diff --git a/crates/ui-egui/src/panels/timeline.rs b/crates/ui-egui/src/panels/timeline.rs
index f1d107d5e..a45d8e708 100644
--- a/crates/ui-egui/src/panels/timeline.rs
+++ b/crates/ui-egui/src/panels/timeline.rs
@@ -15,6 +15,7 @@ use effectcraft_engine::render::EvalCtx;
 use effectcraft_engine::time::Tick;
 use egui::{Align2, Color32, Pos2, Rect, Sense, Stroke, StrokeKind, pos2, vec2};
 use serde_json::json;
+use std::sync::Arc;
 
 use crate::i18n::tr;
 use crate::icons::{self, Icon};
@@ -169,19 +170,24 @@ fn pick_whip_id() -> egui::Id {
     egui::Id::unique("tl-pickwhip")
 }
 
+/// The automation id, label and hover hint of a pick whip.
+struct WhipText<'a> {
+    auto: &'a str,
+    label: &'a str,
+    hint: &'a str,
+}
+
 /// A pick whip at `rect`: dragging it starts a pick whip of `kind` from `layer`'s `prop` (0 for
 /// the layer's own), drawn and dropped at the end of [`show`].
-#[allow(clippy::too_many_arguments)]
 fn pick_whip(
     app: &mut EffectcraftApp,
     ui: &egui::Ui,
     p: &egui::Painter,
     rect: Rect,
     (kind, layer, prop): (u8, u64, u64),
-    auto: &str,
-    label: &str,
-    hint: &str,
+    text: WhipText<'_>,
 ) -> egui::Response {
+    let WhipText { auto, label, hint } = text;
     let resp = ui.interact(rect, egui::Id::unique(("pick-whip", kind, layer, prop)), Sense::drag()).on_hover_text(hint);
     icons::paint(p, rect.shrink(1.0), Icon::PickWhip, if resp.hovered() || resp.dragged() { app.tokens.text } else { app.tokens.text_dim });
     app.auto.add(auto, rect, label);
@@ -1415,12 +1421,9 @@ fn mode_targets(comp: &Comp, layer: LayerId, selected: &[LayerId]) -> Vec<u64> {
     edited_layers(layer, selected).into_iter().filter(|l| comp.layer(LayerId(*l)).is_some_and(|l| l.source.is_av())).collect()
 }
 
-/// A layer's switch (A/V Features and Switches columns) in `row`, with the
-/// [`switch_gesture`].
-#[allow(clippy::too_many_arguments)]
-fn layer_switch(
-    ui: &mut egui::Ui,
-    t: &Tokens,
+/// Where and what a layer switch is: its cell, icon, state and the switch it sets.
+#[derive(Clone, Copy)]
+struct SwitchSpec {
     row: Rect,
     br: Rect,
     icon: Icon,
@@ -1429,11 +1432,20 @@ fn layer_switch(
     layer: u64,
     name: &'static str,
     others: bool,
+}
+
+/// A layer's switch (A/V Features and Switches columns) in `row`, with the
+/// [`switch_gesture`].
+fn layer_switch(
+    ui: &mut egui::Ui,
+    t: &Tokens,
+    spec: &SwitchSpec,
     comp: &Comp,
     project: &Project,
     selected: &[LayerId],
     actions: &mut Vec<(String, serde_json::Value)>,
 ) {
+    let SwitchSpec { row, br, icon, on, id, layer, name, others } = *spec;
     let resp = widgets::icon_toggle(ui, br, icon, on, t, id, Sense::click_and_drag());
     // Alt-click on an A/V feature sets the layer apart: the other layers go off (or locked),
     // and come back on the next Alt-click. With several layers selected, the whole selection is
@@ -1516,54 +1528,108 @@ fn replace_source_target(app: &EffectcraftApp, cid: ItemId, item: ItemId, lid: L
             .is_some_and(|l| !l.switches.locked && matches!(l.source, LayerSource::Footage { .. } | LayerSource::Comp { .. } | LayerSource::Solid { .. }))
 }
 
-/// The Timeline panel for the active composition inside `rect`: draws the header, ruler, work
-/// area and cache bars, the layer rows with their switch and value cells, the time graph and its
-/// keys, and the footer; and turns this frame's clicks, drags and drops into commands. Without an
-/// active comp it shows a hint, and dropping footage on it creates a composition. Most edits
-/// use [`crate::menus::invoke`]; time, switch and work-area gestures call `Session::execute`
-/// directly and ignore errors. Reported failures go to `app.ui.status`. UI state (scroll, zoom,
-/// open rows and the drags in progress) lives in
-/// `app.ui.timeline` and egui's temp data.
-pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+/// The frame's layout and state shared by the Timeline's drawing steps.
+struct Tl {
+    t: Tokens,
+    cid: ItemId,
+    time: Tick,
+    fr: effectcraft_engine::time::FrameRate,
+    rect: Rect,
+    header_h: f32,
+    colhdr_h: f32,
+    footer_h: f32,
+    vis: Vis,
+    left_w: f32,
+    overflow: f32,
+    oscroll: f32,
+    cw: Cols,
+    graph_x0: f32,
+    graph_x1: f32,
+    fit_pps: f64,
+    pps: f64,
+    scroll_to: Option<crate::state::ScrollTo>,
+    tm: TMap,
+    top: f32,
+    rows_rect: Rect,
+    ruler: Rect,
+    bin: Rect,
+    tc_rect: Rect,
+    wa_row: Rect,
+    fd: f64,
+    rh: f32,
+    max_scroll: f32,
+    ctx: egui::Context,
+    comp: Arc<Comp>,
+    p: egui::Painter,
+    rows: Arc<Vec<Row>>,
+    actions: Vec<(String, serde_json::Value)>,
+}
+
+/// [`Tl`] plus what the layer rows and the interactions after them share.
+struct Rw {
+    tl: Tl,
+    lp: egui::Painter,
+    gp: egui::Painter,
+    graph_on: bool,
+    full_clip: Rect,
+    left_clip: Rect,
+    right_clip: Rect,
+    empty_rect: Rect,
+    outline_rect: Rect,
+    empty: egui::Response,
+    outline_empty: egui::Response,
+    selected: Vec<LayerId>,
+    sel_keys: Vec<effectcraft_engine::KeyRef>,
+    ui_actions: Vec<UiAct>,
+    hit_rows: Vec<(Rect, Row)>,
+    dim_hits: Vec<(u64, Vec<Rect>)>,
+}
+
+/// One visible row: what the per-kind drawing steps need to know about it.
+struct RowCtx<'a> {
+    row: &'a Row,
+    layer: &'a Layer,
+    r: Rect,
+    left: Rect,
+    cy: f32,
+    is_sel: bool,
+    ri: usize,
+    indent: f32,
+}
+
+/// The responses of a layer bar's body and its two trim edges.
+struct BarResps {
+    body: egui::Response,
+    lin: egui::Response,
+    lout: egui::Response,
+}
+
+/// An expression row's property, expression and editor ids.
+#[derive(Clone, Copy)]
+struct ExprRow<'a> {
+    prop: &'a Property,
+    ex: &'a effectcraft_engine::project::Expression,
+    buf_id: egui::Id,
+    edit_id: egui::Id,
+}
+
+/// A keyframe marker's hit result.
+struct KeyHit<'a> {
+    k: &'a effectcraft_engine::keyframe::Keyframe,
+    ct: Tick,
+    ks: bool,
+    kresp: egui::Response,
+    mods: egui::Modifiers,
+    this_key: serde_json::Value,
+}
+
+/// Computes this frame's layout: zoom, scroll and the panel's regions.
+fn layout(app: &mut EffectcraftApp, ui: &egui::Ui, rect: Rect, cid: ItemId, comp: &Arc<Comp>) -> Tl {
     let t = app.tokens;
     let ctx = ui.ctx().clone();
-    let Some(cid) = app.session.active_comp_id() else {
-        ui.painter().text(rect.center(), Align2::CENTER_CENTER, "(no composition)", Tokens::ui(12.0), t.text_faint);
-        // Dropping footage into an empty Timeline should create its first composition,
-        // just like dropping onto the Project panel's New Composition button (#649).
-        if let Some(crate::panels::DragPayload::Item(dragged)) = egui::DragAndDrop::payload::<crate::panels::DragPayload>(&ctx).as_deref()
-            && ui.rect_contains_pointer(rect)
-        {
-            let items: Vec<ItemId> = crate::panels::project_drop_items(app, *dragged)
-                .into_iter()
-                .map(ItemId)
-                .filter(|id| {
-                    app.session.project.item(*id).is_some_and(|item| match &item.kind {
-                        effectcraft_engine::project::ItemKind::Footage(footage) => footage.kind != effectcraft_engine::project::FootageKind::Data,
-                        effectcraft_engine::project::ItemKind::Solid(_) | effectcraft_engine::project::ItemKind::Comp(_) => true,
-                        _ => false,
-                    })
-                })
-                .collect();
-            if !items.is_empty() {
-                ui.painter().rect_stroke(rect.shrink(2.0), 0.0, Stroke::new(2.0, t.accent), StrokeKind::Inside);
-                app.auto.add("timeline.newCompDrop", rect, "Drop footage to create a composition");
-                if ctx.input(|i| i.pointer.any_released()) {
-                    app.session.state.project_selection = items;
-                    if let Err(e) = crate::menus::invoke(app, &ctx, "file.newCompFromSelection", json!({})) {
-                        app.ui.status = e;
-                    }
-                    egui::DragAndDrop::clear_payload(&ctx);
-                }
-            }
-        }
-        return;
-    };
-    let Some(comp) = app.session.project.comp_arc(cid) else { return };
     let p = ui.painter().clone();
     let time = app.session.time();
     let fr = comp.frame_rate;
-
     // Geometry.
     let header_h = 48.0;
     let ruler_h = 34.0;
@@ -1581,7 +1647,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let graph_x0 = rect.min.x + left_w + 1.0;
     let graph_x1 = rect.max.x - GUTTER_W;
     ctx.data_mut(|d| d.insert_temp(egui::Id::unique("timeline-graph-area"), (graph_x0, graph_x1 - graph_x0)));
-    let fit_pps = fit_pps(graph_x1 - graph_x0, &comp);
+    let fit_pps = fit_pps(graph_x1 - graph_x0, comp);
     let pps = app.ui.timeline.pps.unwrap_or(fit_pps);
     if app.ui.timeline.pps.is_none() {
         app.ui.timeline.start = 0.0;
@@ -1605,17 +1671,434 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let top = rect.min.y;
     let rows_top = top + header_h + colhdr_h;
     let rows_rect = Rect::from_min_max(pos2(rect.min.x, rows_top), pos2(rect.max.x, rect.max.y - footer_h));
-    let graph_rect = Rect::from_min_max(pos2(graph_x0, top + header_h - ruler_h + colhdr_h), pos2(rect.max.x, rect.max.y - footer_h));
     p.rect_filled(Rect::from_min_max(pos2(graph_x0, top), rect.max), 0.0, t.tl_bg);
     p.line_segment([pos2(graph_x0 - 1.0, top), pos2(graph_x0 - 1.0, rect.max.y)], Stroke::new(1.0, t.app_bg));
 
-    let mut actions: Vec<(String, serde_json::Value)> = Vec::new();
-    if !ui.input(|i| i.pointer.primary_down()) {
-        ctx.data_mut(|d| d.remove::<SwitchDrag>(switch_drag_id()));
-    }
-    // ---- header (left): time display, search, switches.
-    let tc = crate::panels::timecode(&app.session, &comp, time);
+    let ruler = Rect::from_min_max(pos2(graph_x0, top + header_h - ruler_h), pos2(rect.max.x, top + header_h));
+    // The composition marker bin, at the right end of the ruler above the layers' scroll bar.
+    let bin = Rect::from_min_max(pos2(graph_x1 + 2.0, ruler.max.y - 16.0), pos2(rect.max.x - 2.0, ruler.max.y - 2.0));
     let tc_rect = Rect::from_min_size(pos2(rect.min.x + 12.0, top + 6.0), vec2(150.0, 24.0));
+    let wa_row = Rect::from_min_max(pos2(graph_x0, top + header_h), pos2(rect.max.x, top + header_h + colhdr_h));
+    let fd = comp.frame_duration().seconds();
+    Tl {
+        t,
+        cid,
+        time,
+        fr,
+        rect,
+        header_h,
+        colhdr_h,
+        footer_h,
+        vis,
+        left_w,
+        overflow,
+        oscroll,
+        cw,
+        graph_x0,
+        graph_x1,
+        fit_pps,
+        pps,
+        scroll_to,
+        tm,
+        top,
+        rows_rect,
+        ruler,
+        bin,
+        tc_rect,
+        wa_row,
+        fd,
+        rh: t.row_h,
+        max_scroll: 0.0,
+        ctx,
+        comp: comp.clone(),
+        p,
+        rows: Arc::new(Vec::new()),
+        actions: Vec::new(),
+    }
+}
+
+/// Without an active composition: a hint, and dropping footage creates the first composition.
+fn empty_timeline(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+    let t = app.tokens;
+    let ctx = ui.ctx().clone();
+    ui.painter().text(rect.center(), Align2::CENTER_CENTER, "(no composition)", Tokens::ui(12.0), t.text_faint);
+    // Dropping footage into an empty Timeline should create its first composition,
+    // just like dropping onto the Project panel's New Composition button (#649).
+    if let Some(crate::panels::DragPayload::Item(dragged)) = egui::DragAndDrop::payload::<crate::panels::DragPayload>(&ctx).as_deref()
+        && ui.rect_contains_pointer(rect)
+    {
+        let items: Vec<ItemId> = crate::panels::project_drop_items(app, *dragged)
+            .into_iter()
+            .map(ItemId)
+            .filter(|id| {
+                app.session.project.item(*id).is_some_and(|item| match &item.kind {
+                    effectcraft_engine::project::ItemKind::Footage(footage) => footage.kind != effectcraft_engine::project::FootageKind::Data,
+                    effectcraft_engine::project::ItemKind::Solid(_) | effectcraft_engine::project::ItemKind::Comp(_) => true,
+                    _ => false,
+                })
+            })
+            .collect();
+        if !items.is_empty() {
+            ui.painter().rect_stroke(rect.shrink(2.0), 0.0, Stroke::new(2.0, t.accent), StrokeKind::Inside);
+            app.auto.add("timeline.newCompDrop", rect, "Drop footage to create a composition");
+            if ctx.input(|i| i.pointer.any_released()) {
+                app.session.state.project_selection = items;
+                if let Err(e) = crate::menus::invoke(app, &ctx, "file.newCompFromSelection", json!({})) {
+                    app.ui.status = e;
+                }
+                egui::DragAndDrop::clear_payload(&ctx);
+            }
+        }
+    }
+}
+
+/// Starts the rows pass: the clipped painters and the background responses.
+fn begin_rows(app: &mut EffectcraftApp, ui: &mut egui::Ui, tl: Tl) -> Rw {
+    let rows_rect = tl.rows_rect;
+    let graph_x0 = tl.graph_x0;
+    let rect = tl.rect;
+    let lp = tl.p.with_clip_rect(rows_rect.intersect(Rect::from_min_max(rows_rect.min, pos2(graph_x0 - 1.0, rows_rect.max.y))));
+    let gp = tl.p.with_clip_rect(rows_rect.intersect(Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max)));
+    let graph_on = app.ui.timeline.graph_editor;
+    super::graph::track_open(ui.ctx(), graph_on);
+    let full_clip = ui.clip_rect();
+    let left_clip = full_clip.intersect(Rect::from_min_max(pos2(rect.min.x, rows_rect.min.y), pos2(graph_x0 - 1.0, rows_rect.max.y)));
+    let right_clip = full_clip.intersect(Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max));
+    // Registered before the rows so keys, bars and editors on top of it get the pointer first.
+    let empty_rect = if graph_on { Rect::NOTHING } else { Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max) };
+    let empty = ui.interact(empty_rect, egui::Id::unique("tl-graph-bg"), Sense::click_and_drag());
+    let outline_rect = Rect::from_min_max(rows_rect.min, pos2(graph_x0 - 1.0, rows_rect.max.y));
+    let outline_empty = ui.interact(outline_rect, egui::Id::unique("tl-layer-bg"), Sense::click_and_drag());
+    app.auto.add("timeline.layerMarquee", outline_rect, "Drag empty outline to select layers");
+    Rw {
+        lp,
+        gp,
+        graph_on,
+        full_clip,
+        left_clip,
+        right_clip,
+        empty_rect,
+        outline_rect,
+        empty,
+        outline_empty,
+        selected: app.session.state.selected_layers.clone(),
+        sel_keys: app.session.state.selected_keys.clone(),
+        ui_actions: Vec::new(),
+        hit_rows: Vec::new(),
+        dim_hits: Vec::new(),
+        tl,
+    }
+}
+
+/// The Timeline panel for the active composition inside `rect`: draws the header, ruler, work
+/// area and cache bars, the layer rows with their switch and value cells, the time graph and its
+/// keys, and the footer; and turns this frame's clicks, drags and drops into commands. Without an
+/// active comp it shows a hint, and dropping footage on it creates a composition. Most edits
+/// use [`crate::menus::invoke`]; time, switch and work-area gestures call `Session::execute`
+/// directly and ignore errors. Reported failures go to `app.ui.status`. UI state (scroll, zoom,
+/// open rows and the drags in progress) lives in
+/// `app.ui.timeline` and egui's temp data.
+pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+    let Some(cid) = app.session.active_comp_id() else {
+        empty_timeline(app, ui, rect);
+        return;
+    };
+    let Some(comp) = app.session.project.comp_arc(cid) else { return };
+    let mut tl = layout(app, ui, rect, cid, &comp);
+    let g = &mut tl;
+    if !ui.input(|i| i.pointer.primary_down()) {
+        g.ctx.data_mut(|d| d.remove::<SwitchDrag>(switch_drag_id()));
+    }
+    header_timecode(app, ui, g);
+    header_search_and_switches(app, ui, g);
+    time_navigator(app, ui, g);
+    ruler_background(app, g);
+    work_area_bar(app, ui, g);
+    cache_bars(app, g);
+    ruler_ticks(app, g);
+    ruler_scrub(app, ui, g);
+    column_header_icons(app, g);
+    column_header_interact(app, ui, g);
+    let rows = Arc::new(with_expr_rows(build_rows(app, &comp), &comp, &app.ui.timeline, &g.ctx));
+    let total_h: f32 = rows.iter().map(|r| row_height(r, g.rh)).sum();
+    g.max_scroll = (total_h - g.rows_rect.height() + g.rh).max(0.0);
+    g.rows = rows;
+    reveal_scroll(app, g);
+    wheel_zoom_scroll(app, ui, g);
+    pick_whip_edge_scroll(app, g);
+    let snap_project = app.session.project.clone();
+    let snap_expr = app.session.expr.clone();
+    let ectx = EvalCtx { project: &snap_project, comp_id: cid, comp: &comp, time: g.time, expr: snap_expr.as_deref(), footage: None };
+    let mut rw = begin_rows(app, ui, tl);
+    let g = &mut rw;
+    draw_rows(app, ui, g, &ectx);
+    ui.set_clip_rect(g.full_clip);
+    background_menus(app, ui, g);
+    outline_marquee(ui, g);
+    pick_whip_drag(g);
+    alt_scale_and_graph(app, ui, g, &ectx);
+    graph_empty_area(ui, g);
+    layer_reorder_drag(ui, g);
+    quick_offset_follow(g);
+    key_drag_follow(app, g);
+    key_box_select(app, ui, g);
+    current_time_indicator(app, g);
+    let footer = footer_bar(app, ui, g);
+    footer_zoom(app, ui, g, footer);
+    comp_markers_ui(app, ui, g);
+    hand_tool_pan(app, ui, g);
+    drop_targets(app, ui, g);
+    let Rw { tl, ui_actions, .. } = rw;
+    apply_ui_acts(app, &tl.comp, ui_actions);
+    apply_actions(app, ui, &tl.ctx, tl.actions);
+}
+
+/// Applies the UI-only changes the frame collected (twirls, time, ending an undo merge).
+fn apply_ui_acts(app: &mut EffectcraftApp, comp: &Comp, ui_actions: Vec<UiAct>) {
+    for a in ui_actions {
+        match a {
+            UiAct::ToggleLayer(id, all) => {
+                let tl = &mut app.ui.timeline;
+                // Twirled by hand, the layer shows its whole tree again.
+                tl.reveal.clear();
+                tl.layer_reveal.remove(&id);
+                tl.full_groups.remove(&id);
+                let open = !tl.open_layers.contains(&id);
+                if open {
+                    tl.open_layers.insert(id);
+                } else {
+                    tl.open_layers.remove(&id);
+                }
+                if all && let Some(l) = comp.layer(LayerId(id)) {
+                    let mut uids = vec![];
+                    walk_groups(&l.props, &mut uids);
+                    for u in uids {
+                        if open {
+                            tl.open_groups.insert(u);
+                        } else {
+                            tl.open_groups.remove(&u);
+                        }
+                    }
+                }
+            }
+            UiAct::ToggleGroup(layer, uid, all) => {
+                let tl = &mut app.ui.timeline;
+                tl.toggle_group(layer, uid);
+                let open = tl.open_groups.contains(&uid);
+                if all && let Some(g) = comp.layer(LayerId(layer)).and_then(|l| find_group(&l.props, uid)) {
+                    let mut uids = vec![];
+                    walk_groups(g, &mut uids);
+                    for u in uids {
+                        if open {
+                            tl.open_groups.insert(u);
+                        } else {
+                            tl.open_groups.remove(&u);
+                        }
+                    }
+                }
+            }
+            UiAct::SetTime(tt) => app.session.set_time(tt),
+            UiAct::EndMerge => app.session.history.merge_key = None,
+            UiAct::ChangeRenderer => {
+                if super::dialogs::open_comp_settings(app).is_ok() {
+                    app.dialog_state.comp.tab = super::comp_settings::Tab::Renderer;
+                }
+            }
+        }
+    }
+}
+
+/// Runs the commands the frame collected through [`crate::menus::invoke`].
+fn apply_actions(app: &mut EffectcraftApp, ui: &mut egui::Ui, ctx: &egui::Context, actions: Vec<(String, serde_json::Value)>) {
+    if ui.input(|i| i.pointer.primary_down()) && actions.iter().any(|(id, _)| id == "prop.set") {
+        app.ui.viewer.property_interacting = true;
+        ctx.request_repaint();
+    }
+    for (id, params) in actions {
+        if id == "__endMerge" {
+            app.session.history.merge_key = None;
+            continue;
+        }
+        if let Err(e) = crate::menus::invoke(app, ctx, &id, params) {
+            app.ui.status = e;
+        }
+    }
+}
+
+/// Draws the visible rows, top to bottom, each by its kind.
+fn draw_rows(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, ectx: &EvalCtx<'_>) {
+    let comp = g.tl.comp.clone();
+    let rows = g.tl.rows.clone();
+    let (rect, rows_rect, rh, cw_name) = (g.tl.rect, g.tl.rows_rect, g.tl.rh, g.tl.cw.name);
+    let mut y = rows_rect.min.y - app.ui.timeline.scroll_y;
+    // Rows stripe by their index among the rows that are not expression editors, so adding or
+    // removing an expression leaves every other row's stripe alone; an editor takes the index
+    // (and so the stripe) of its property's row, the one just above.
+    let mut striped = 0usize;
+    for row in rows.iter() {
+        let ri = if matches!(row.kind, RowKind::Expr { .. }) {
+            striped.saturating_sub(1)
+        } else {
+            striped += 1;
+            striped - 1
+        };
+        // Outline widgets never spill into the time graph (narrow timelines).
+        ui.set_clip_rect(g.left_clip);
+        let hh = row_height(row, rh);
+        let r = Rect::from_min_size(pos2(rect.min.x, y), vec2(rect.width(), hh));
+        y += hh;
+        if r.max.y < rows_rect.min.y || r.min.y > rows_rect.max.y {
+            continue;
+        }
+        g.hit_rows.push((r, row.clone()));
+        let Some(layer) = comp.layer(row.layer) else { continue };
+        let rc = RowCtx {
+            row,
+            layer,
+            r,
+            left: Rect::from_min_max(r.min, pos2(g.tl.graph_x0 - 1.0, r.max.y)),
+            cy: r.min.y + rh / 2.0,
+            is_sel: g.selected.contains(&layer.id),
+            ri,
+            indent: cw_name + 6.0 + 14.0 * row.depth as f32,
+        };
+        match &row.kind {
+            RowKind::Layer => layer_row(app, ui, g, &rc),
+            RowKind::Group { .. } => group_row(app, ui, g, &rc),
+            RowKind::Waveform { .. } => waveform_row(app, g, &rc),
+            RowKind::Expr { .. } => expr_row(app, ui, g, &rc),
+            RowKind::Prop { .. } => prop_row(app, ui, g, &rc, ectx),
+        }
+    }
+}
+
+/// A layer row: switches, label, name, cells and the layer bar.
+fn layer_row(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    layer_row_background(g, rc);
+    layer_av_switches(app, ui, g, rc);
+    layer_label_swatch(app, ui, g, rc);
+    layer_number_and_cells(app, ui, g, rc);
+    let (row_resp, name_x) = layer_twirl_and_icon(app, ui, g, rc);
+    layer_name(app, ui, g, rc, name_x);
+    layer_row_actions(app, ui, g, rc, &row_resp);
+    layer_switches(app, ui, g, rc);
+    if app.ui.timeline.show_modes && rc.layer.source.is_av() {
+        layer_mode_cell(app, ui, g, rc);
+        layer_matte_cell(app, ui, g, rc);
+    }
+    if g.tl.vis.parent {
+        layer_parent_cell(app, ui, g, rc);
+    }
+    ui.set_clip_rect(g.right_clip);
+    if !g.graph_on {
+        layer_bar(app, ui, g, rc);
+    }
+}
+
+/// The layer's duration bar: source extent, move and trim, markers.
+fn layer_bar(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let (bar, lc) = layer_bar_paint(g, rc);
+    layer_source_extent(app, ui, g, rc, bar, lc);
+    let bars = layer_bar_hits(app, ui, g, rc, bar);
+    let quick = layer_quick_offset_begin(ui, g, rc, &bars.body);
+    layer_bar_drag(g, rc, &bars, quick);
+    layer_bar_markers(app, ui, g, rc);
+}
+
+/// A group row (effect, mask, shape group, layer style).
+fn group_row(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let shown = group_background(app, g, rc);
+    group_switches(app, ui, g, rc);
+    group_name(app, ui, g, rc, &shown);
+    group_popups(app, ui, g, rc);
+    group_mask_mode(ui, g, rc);
+    group_row_click(app, ui, g, rc);
+}
+
+/// An expression row: its controls and the editor.
+fn expr_row(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let RowKind::Expr { uid, .. } = &rc.row.kind else { return };
+    let Some(prop) = rc.layer.props.find(*uid) else { return };
+    let Some(ex) = prop.expr.as_ref() else { return };
+    let st = ExprRow { prop, ex, buf_id: expr_buf_id(*uid), edit_id: egui::Id::unique(("expr-edit", uid)) };
+    expr_controls(app, ui, g, rc, &st);
+    expr_language_menu(app, ui, g, rc, &st);
+    expr_editor_cell(app, ui, g, rc, &st);
+}
+
+/// A property row: keyframe navigator, stopwatch, name, value editors and the keyframes.
+fn prop_row(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, ectx: &EvalCtx<'_>) {
+    let RowKind::Prop { uid } = &rc.row.kind else { return };
+    let Some(prop) = rc.layer.props.find(*uid) else { return };
+    prop_background(app, g, rc, prop);
+    prop_key_navigator(app, ui, g, rc, prop);
+    prop_stopwatch(app, ui, g, rc, prop);
+    let name_x = prop_name(app, ui, g, rc, prop);
+    prop_value_cell(app, ui, g, rc, ectx, prop, name_x);
+    prop_expression_hint(app, ui, g, rc, prop);
+    if !g.graph_on {
+        for k in &prop.keys {
+            key_marker(app, ui, g, rc, prop, k);
+        }
+    }
+}
+
+/// One keyframe marker: its look, selection, menu and drag.
+fn key_marker(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, prop: &Property, k: &effectcraft_engine::keyframe::Keyframe) {
+    let RowKind::Prop { uid } = &rc.row.kind else { return };
+    let ct = rc.layer.comp_time(k.time);
+    let x = g.tl.tm.x(ct.seconds());
+    if x < g.tl.graph_x0 - 8.0 || x > g.tl.rect.max.x + 8.0 {
+        return;
+    }
+    let kref = effectcraft_engine::KeyRef { layer: rc.layer.id, prop: *uid, time: k.time };
+    let ks = g.sel_keys.contains(&kref);
+    let kr = key_paint(g, rc, k, x, ks);
+    let kresp = key_hit(app, ui, g, rc, prop, k, kr);
+    let mods = ui.input(|i| i.modifiers);
+    let this_key = json!({"keys": [{"layer": rc.layer.id.0, "prop": uid, "time": k.time.seconds()}], "selectProperties": true});
+    let kh = KeyHit { k, ct, ks, kresp, mods, this_key };
+    key_select(g, &kh);
+    key_double_click(g, rc, prop, &kh);
+    key_context_menu(app, g, rc, prop, &kh);
+    key_drag_begin(app, g, &kh);
+}
+
+/// Drop targets: effects and presets on a layer, footage and files into the stack.
+fn drop_targets(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw) {
+    let ctx = g.tl.ctx.clone();
+    let rows_rect = g.tl.rows_rect;
+    if let Some(payload) = egui::DragAndDrop::payload::<crate::panels::DragPayload>(&ctx)
+        && !matches!(*payload, crate::panels::DragPayload::Property { .. })
+        && let Some(ptr) = ctx.input(|i| i.pointer.hover_pos()).filter(|_| ui.rect_contains_pointer(rows_rect))
+    {
+        let released = ctx.input(|i| i.pointer.any_released());
+        // Alt/Option-drag from the Project panel replaces the source of the layer under the
+        // pointer (After Effects). The shortcut replaces every selected layer instead.
+        let alt_item = ctx.input(|i| i.modifiers.alt) && matches!(payload.as_ref(), crate::panels::DragPayload::Item(_));
+        if alt_item {
+            drop_replace_source(app, g, &payload, ptr, released);
+        } else if matches!(payload.as_ref(), crate::panels::DragPayload::Effect(_) | crate::panels::DragPayload::Preset { .. }) {
+            drop_on_layer(app, g, &payload, ptr, released);
+        } else {
+            drop_insert_layers(app, g, &payload, ptr, released);
+        }
+        if released {
+            egui::DragAndDrop::clear_payload(&ctx);
+        }
+    }
+}
+
+/// The header's time display: click to switch style, drag to scrub, double-click to type a time.
+fn header_timecode(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Tl) {
+    let t = g.t;
+    let time = g.time;
+    let fr = g.fr;
+    let tc_rect = g.tc_rect;
+    let ctx = g.ctx.clone();
+    let comp = g.comp.clone();
+    let p = g.p.clone();
+    let tc = crate::panels::timecode(&app.session, &comp, time);
     let tc_resp = ui.interact(tc_rect, egui::Id::unique("tl-timecode"), Sense::click_and_drag());
     p.text(tc_rect.left_center(), Align2::LEFT_CENTER, &tc, Tokens::semibold(16.0), t.timecode);
     // Under it the other style (frames under timecode, timecode under frames) and the rate.
@@ -1657,6 +2140,16 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             ctx.data_mut(|d| d.insert_temp(egui::Id::unique("tl-tc-edit"), buf));
         }
     }
+}
+
+/// The header's search field and the composition switches.
+fn header_search_and_switches(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Tl) {
+    let t = g.t;
+    let rect = g.rect;
+    let left_w = g.left_w;
+    let top = g.top;
+    let tc_rect = g.tc_rect;
+    let comp = g.comp.clone();
     let sr = Rect::from_min_size(pos2(tc_rect.max.x + 14.0, top + 12.0), vec2((left_w - 420.0).clamp(120.0, 220.0), 22.0));
     let mut search = app.ui.timeline.search.clone();
     widgets::search_field(ui, sr, &mut search, "Search", &t);
@@ -1685,11 +2178,20 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
         bx -= 28.0;
     }
+}
 
-    // ---- ruler (right).
-    let ruler = Rect::from_min_max(pos2(graph_x0, top + header_h - ruler_h), pos2(rect.max.x, top + header_h));
-    // The composition marker bin, at the right end of the ruler above the layers' scroll bar.
-    let bin = Rect::from_min_max(pos2(graph_x1 + 2.0, ruler.max.y - 16.0), pos2(rect.max.x - 2.0, ruler.max.y - 2.0));
+/// The time navigator: the visible span as a bar with end handles.
+fn time_navigator(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Tl) {
+    let t = g.t;
+    let graph_x0 = g.graph_x0;
+    let graph_x1 = g.graph_x1;
+    let fit_pps = g.fit_pps;
+    let pps = g.pps;
+    let tm = g.tm;
+    let top = g.top;
+    let ctx = g.ctx.clone();
+    let comp = g.comp.clone();
+    let p = g.p.clone();
     let nav = Rect::from_min_max(pos2(graph_x0 + 6.0, top + 6.0), pos2(graph_x1, top + 14.0));
     // Time navigator: the visible span as a grey bar with blue end handles (as in After
     // Effects), over a dark track.
@@ -1730,12 +2232,31 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             set_zoom(&mut app.ui.timeline, &comp, span_px / span.max(min_span), fit_pps, keep_t, keep_px);
         }
     }
+}
+
+fn ruler_background(app: &mut EffectcraftApp, g: &Tl) {
+    let t = g.t;
+    let tm = g.tm;
+    let ruler = g.ruler;
+    let p = g.p.clone();
     p.rect_filled(ruler, 0.0, t.tl_ruler_bg);
     app.auto.add("timeline.ruler", ruler, &format!("{},{}", tm.start, tm.pps));
+}
+
+/// The work area bar beside the column headers, with its begin / end handles.
+fn work_area_bar(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Tl) {
+    let t = g.t;
+    let fr = g.fr;
+    let pps = g.pps;
+    let tm = g.tm;
+    let wa_row = g.wa_row;
+    let ctx = g.ctx.clone();
+    let comp = g.comp.clone();
+    let p = g.p.clone();
+    let actions = &mut g.actions;
     // Work area bar: below the ruler, beside the column headers (After Effects' layout), with
     // blue begin / end handles; the cache bar runs under it. Dragging the bar moves the work
     // area, the handles move its ends; Shift snaps (#252).
-    let wa_row = Rect::from_min_max(pos2(graph_x0, top + header_h), pos2(rect.max.x, top + header_h + colhdr_h));
     let (wa0, wa1) = (comp.work_area.0.seconds(), comp.work_area.1.seconds());
     let wa = Rect::from_min_max(pos2(tm.x(wa0), wa_row.min.y + 3.0), pos2(tm.x(wa1), wa_row.max.y - 6.0));
     p.with_clip_rect(wa_row).rect_filled(wa, 0.0, t.tl_work_area_bar);
@@ -1791,10 +2312,20 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             let _ = app.session.execute("comp.workArea", json!({key: secs, "merge": "wa-drag"}));
         }
     }
+}
+
+/// The RAM (green) and disk (blue) cache bars under the work area.
+fn cache_bars(app: &mut EffectcraftApp, g: &Tl) {
+    let t = g.t;
+    let cid = g.cid;
+    let tm = g.tm;
+    let wa_row = g.wa_row;
+    let fd = g.fd;
+    let comp = g.comp.clone();
+    let p = g.p.clone();
     // Cache bar (green: cached frames of what the viewer shows: its resolution, view and options).
     let series = app.shown_series(cid);
     let cached = app.frames.cached_frames(&series);
-    let fd = comp.frame_duration().seconds();
     let cy0 = wa_row.max.y - 4.0;
     let mut run: Option<(i64, i64)> = None;
     let draw_run = |a: i64, b: i64| {
@@ -1843,6 +2374,20 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             draw_blue(a, b);
         }
     }
+}
+
+/// The ruler's tick marks and labels.
+fn ruler_ticks(app: &mut EffectcraftApp, g: &Tl) {
+    let t = g.t;
+    let fr = g.fr;
+    let graph_x0 = g.graph_x0;
+    let graph_x1 = g.graph_x1;
+    let pps = g.pps;
+    let tm = g.tm;
+    let ruler = g.ruler;
+    let bin = g.bin;
+    let fd = g.fd;
+    let p = g.p.clone();
     // Ticks + labels.
     // Label spacing in whole frames (AE: `00:15f`-style seconds:frames labels).
     let fps_i = fr.as_f64().round().max(1.0) as i64;
@@ -1871,6 +2416,17 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
         s += secs_per_label;
     }
+}
+
+/// Scrubbing in the ruler: the current time follows the pointer.
+fn ruler_scrub(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Tl) {
+    let graph_x0 = g.graph_x0;
+    let graph_x1 = g.graph_x1;
+    let pps = g.pps;
+    let tm = g.tm;
+    let ruler = g.ruler;
+    let bin = g.bin;
+    let comp = g.comp.clone();
     // Scrub in the ruler: the current time jumps to the pointer as soon as the button goes down
     // (After Effects), then follows it.
     let rresp = ui.interact(
@@ -1929,8 +2485,19 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             app.scrub_audio(cid, t, now);
         }
     }
+}
 
-    // ---- column headers (right-click: show/hide columns; click the name header: Source/Layer Name).
+/// The column headers' background, icons and titles.
+fn column_header_icons(app: &mut EffectcraftApp, g: &Tl) {
+    let t = g.t;
+    let rect = g.rect;
+    let header_h = g.header_h;
+    let colhdr_h = g.colhdr_h;
+    let vis = g.vis;
+    let graph_x0 = g.graph_x0;
+    let top = g.top;
+    let p = g.p.clone();
+    let cw = &g.cw;
     let ch = Rect::from_min_max(pos2(rect.min.x, top + header_h), pos2(rect.max.x, top + header_h + colhdr_h));
     p.rect_filled(Rect::from_min_max(ch.min, pos2(graph_x0 - 1.0, ch.max.y)), 0.0, t.panel_bg);
     p.line_segment([pos2(rect.min.x, ch.max.y), pos2(rect.max.x, ch.max.y)], Stroke::new(1.0, t.separator));
@@ -1980,6 +2547,20 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             htext(x + 6.0, s);
         }
     }
+}
+
+/// Column header clicks, automation ids and the right-click column menu.
+fn column_header_interact(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Tl) {
+    let rect = g.rect;
+    let header_h = g.header_h;
+    let colhdr_h = g.colhdr_h;
+    let vis = g.vis;
+    let graph_x0 = g.graph_x0;
+    let top = g.top;
+    let ctx = g.ctx.clone();
+    let cw = &g.cw;
+    let actions = &mut g.actions;
+    let ch = Rect::from_min_max(pos2(rect.min.x, top + header_h), pos2(rect.max.x, top + header_h + colhdr_h));
     let hdr_rect = Rect::from_min_max(ch.min, pos2(graph_x0 - 1.0, ch.max.y));
     let hresp = ui.interact(hdr_rect, egui::Id::unique("tl-colhdr"), Sense::click());
     app.auto.add("timeline.header", hdr_rect, "Columns (right-click)");
@@ -2004,12 +2585,12 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
     if hresp.clicked()
         && let Some(pt) = hresp.interact_pointer_pos()
-        && column_at(&cw, pt.x) == Some("name")
+        && column_at(cw, pt.x) == Some("name")
     {
         app.ui.timeline.source_name = !app.ui.timeline.source_name;
     }
     if hresp.secondary_clicked() {
-        let under = hresp.interact_pointer_pos().and_then(|pt| column_at(&cw, pt.x));
+        let under = hresp.interact_pointer_pos().and_then(|pt| column_at(cw, pt.x));
         ctx.data_mut(|d| d.insert_temp(egui::Id::unique("tl-colhdr-under"), under.unwrap_or("")));
     }
     crate::widgets::context_menu(&hresp, |ui| {
@@ -2034,12 +2615,16 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
     });
     let _ = cw.end;
+}
 
-    // ---- rows.
-    let rows = with_expr_rows(build_rows(app, &comp), &comp, &app.ui.timeline, &ctx);
-    let rh = t.row_h;
-    let total_h: f32 = rows.iter().map(|r| row_height(r, rh)).sum();
-    let max_scroll = (total_h - rows_rect.height() + rh).max(0.0);
+/// Scrolls an expression editor or the requested layer / property into view.
+fn reveal_scroll(app: &mut EffectcraftApp, g: &Tl) {
+    let scroll_to = g.scroll_to;
+    let rows_rect = g.rows_rect;
+    let rh = g.rh;
+    let ctx = g.ctx.clone();
+    let comp = g.comp.clone();
+    let rows = &g.rows;
     // An expression editor asked to take the keyboard comes into view; a request whose
     // expression didn't appear, or that wasn't taken within a few passes, is dropped (it never
     // takes the keyboard later).
@@ -2065,6 +2650,18 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     {
         app.ui.timeline.scroll_y = rows.iter().take(i).map(|r| row_height(r, rh)).sum();
     }
+}
+
+/// Mouse wheel and pinch over the rows: zoom time or scroll.
+fn wheel_zoom_scroll(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Tl) {
+    let overflow = g.overflow;
+    let graph_x0 = g.graph_x0;
+    let fit_pps = g.fit_pps;
+    let pps = g.pps;
+    let tm = g.tm;
+    let rows_rect = g.rows_rect;
+    let max_scroll = g.max_scroll;
+    let comp = g.comp.clone();
     if ui.rect_contains_pointer(rows_rect) {
         let (dy, dx, zoom) = ui.input(|i| (i.smooth_scroll_delta.y, i.smooth_scroll_delta.x, i.modifiers.alt));
         // Ctrl/Cmd+wheel and a trackpad pinch reach egui as a zoom factor rather than a scroll
@@ -2090,6 +2687,15 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
         }
     }
+}
+
+/// A held pick whip near the top or bottom scrolls the rows.
+fn pick_whip_edge_scroll(app: &mut EffectcraftApp, g: &Tl) {
+    let rect = g.rect;
+    let rows_rect = g.rows_rect;
+    let rh = g.rh;
+    let max_scroll = g.max_scroll;
+    let ctx = g.ctx.clone();
     // A pick whip held near the top or bottom of the layers (or past it) scrolls them, as in
     // After Effects.
     if ctx.data(|d| d.get_temp::<PickWhip>(pick_whip_id())).is_some()
@@ -2102,1095 +2708,1453 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
     }
     app.ui.timeline.scroll_y = app.ui.timeline.scroll_y.clamp(0.0, max_scroll);
-    let snap_project = app.session.project.clone();
-    let snap_expr = app.session.expr.clone();
-    let ectx = EvalCtx { project: &snap_project, comp_id: cid, comp: &comp, time, expr: snap_expr.as_deref(), footage: None };
-    let lp = p.with_clip_rect(rows_rect.intersect(Rect::from_min_max(rows_rect.min, pos2(graph_x0 - 1.0, rows_rect.max.y))));
-    let gp = p.with_clip_rect(rows_rect.intersect(Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max)));
-    let mut y = rows_rect.min.y - app.ui.timeline.scroll_y;
-    let selected = app.session.state.selected_layers.clone();
-    let sel_keys = app.session.state.selected_keys.clone();
-    let mut ui_actions: Vec<UiAct> = Vec::new();
-    let idx_of = |id: LayerId| comp.index_of(id).unwrap_or(0);
-    let graph_on = app.ui.timeline.graph_editor;
-    super::graph::track_open(ui.ctx(), graph_on);
-    let full_clip = ui.clip_rect();
-    let left_clip = full_clip.intersect(Rect::from_min_max(pos2(rect.min.x, rows_rect.min.y), pos2(graph_x0 - 1.0, rows_rect.max.y)));
-    let right_clip = full_clip.intersect(Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max));
-    // Registered before the rows so keys, bars and editors on top of it get the pointer first.
-    let empty_rect = if graph_on { Rect::NOTHING } else { Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max) };
-    let empty = ui.interact(empty_rect, egui::Id::unique("tl-graph-bg"), Sense::click_and_drag());
-    let outline_rect = Rect::from_min_max(rows_rect.min, pos2(graph_x0 - 1.0, rows_rect.max.y));
-    let outline_empty = ui.interact(outline_rect, egui::Id::unique("tl-layer-bg"), Sense::click_and_drag());
-    app.auto.add("timeline.layerMarquee", outline_rect, "Drag empty outline to select layers");
-    let mut hit_rows: Vec<(Rect, Row)> = vec![];
-    // The value fields of multi-dimension properties (per dimension), for the pick whip.
-    let mut dim_hits: Vec<(u64, Vec<Rect>)> = vec![];
-    // Rows stripe by their index among the rows that are not expression editors, so adding or
-    // removing an expression leaves every other row's stripe alone; an editor takes the index
-    // (and so the stripe) of its property's row, the one just above.
-    let mut striped = 0usize;
-    for row in rows.iter() {
-        let ri = if matches!(row.kind, RowKind::Expr { .. }) {
-            striped.saturating_sub(1)
-        } else {
-            striped += 1;
-            striped - 1
-        };
-        // Outline widgets never spill into the time graph (narrow timelines).
-        ui.set_clip_rect(left_clip);
-        let hh = row_height(row, rh);
-        let r = Rect::from_min_size(pos2(rect.min.x, y), vec2(rect.width(), hh));
-        y += hh;
-        if r.max.y < rows_rect.min.y || r.min.y > rows_rect.max.y {
+}
+
+fn layer_row_background(g: &Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let rect = g.tl.rect;
+    let graph_x0 = g.tl.graph_x0;
+    let lp = g.lp.clone();
+    let gp = g.gp.clone();
+    let r = rc.r;
+    let left = rc.left;
+    let is_sel = rc.is_sel;
+    lp.rect_filled(left, 0.0, if is_sel { t.row_selected } else { t.row_alt });
+    gp.rect_filled(Rect::from_min_max(pos2(graph_x0, r.min.y), r.max), 0.0, if is_sel { t.tl_graph_selected } else { t.tl_bg });
+    lp.line_segment([pos2(rect.min.x, r.max.y - 0.5), pos2(graph_x0, r.max.y - 0.5)], Stroke::new(1.0, t.app_bg));
+    gp.line_segment([pos2(graph_x0, r.max.y - 0.5), pos2(r.max.x, r.max.y - 0.5)], Stroke::new(1.0, t.app_bg));
+}
+
+/// The A/V feature switches (video, audio, solo, lock).
+fn layer_av_switches(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let vis = g.tl.vis;
+    let comp = g.tl.comp.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let selected = &g.selected;
+    let layer = rc.layer;
+    let r = rc.r;
+    let cy = rc.cy;
+    let sw = &layer.switches;
+    // Every layer has the Video switch (the eye), nulls, cameras and lights included,
+    // as in After Effects: it hides a null's outline in the viewer and turns a camera or
+    // light off.
+    let av_items: [(Icon, bool, &str, bool); 4] = [
+        (Icon::Eye, sw.video, "video", switch_applies(layer, "video", &app.session.project)),
+        (Icon::Speaker, sw.audio, "audio", switch_applies(layer, "audio", &app.session.project)),
+        (Icon::Solo, sw.solo, "solo", switch_applies(layer, "solo", &app.session.project)),
+        (Icon::Lock, sw.locked, "lock", switch_applies(layer, "lock", &app.session.project)),
+    ];
+    for (i, (icon, on, name, applicable)) in av_items.into_iter().enumerate() {
+        let br = Rect::from_center_size(pos2(cw.av + 10.0 + 18.0 * i as f32, cy), vec2(15.0, 15.0));
+        if !applicable || !vis.av {
             continue;
         }
-        hit_rows.push((r, row.clone()));
-        let Some(layer) = comp.layer(row.layer) else { continue };
-        let is_sel = selected.contains(&layer.id);
-        let left = Rect::from_min_max(r.min, pos2(graph_x0 - 1.0, r.max.y));
-        let cy = r.min.y + rh / 2.0;
-        match &row.kind {
-            RowKind::Layer => {
-                // After Effects draws layer rows as one flat tone separated by dark hairlines
-                // (outline and time graph alike), not as alternating stripes.
-                let _ = ri;
-                lp.rect_filled(left, 0.0, if is_sel { t.row_selected } else { t.row_alt });
-                gp.rect_filled(Rect::from_min_max(pos2(graph_x0, r.min.y), r.max), 0.0, if is_sel { t.tl_graph_selected } else { t.tl_bg });
-                lp.line_segment([pos2(rect.min.x, r.max.y - 0.5), pos2(graph_x0, r.max.y - 0.5)], Stroke::new(1.0, t.app_bg));
-                gp.line_segment([pos2(graph_x0, r.max.y - 0.5), pos2(r.max.x, r.max.y - 0.5)], Stroke::new(1.0, t.app_bg));
-                // A/V features.
-                let sw = &layer.switches;
-                // Every layer has the Video switch (the eye), nulls, cameras and lights included,
-                // as in After Effects: it hides a null's outline in the viewer and turns a camera or
-                // light off.
-                let av_items: [(Icon, bool, &str, bool); 4] = [
-                    (Icon::Eye, sw.video, "video", switch_applies(layer, "video", &app.session.project)),
-                    (Icon::Speaker, sw.audio, "audio", switch_applies(layer, "audio", &app.session.project)),
-                    (Icon::Solo, sw.solo, "solo", switch_applies(layer, "solo", &app.session.project)),
-                    (Icon::Lock, sw.locked, "lock", switch_applies(layer, "lock", &app.session.project)),
-                ];
-                for (i, (icon, on, name, applicable)) in av_items.into_iter().enumerate() {
-                    let br = Rect::from_center_size(pos2(cw.av + 10.0 + 18.0 * i as f32, cy), vec2(15.0, 15.0));
-                    if !applicable || !vis.av {
-                        continue;
-                    }
-                    lp.rect_filled(br.shrink(0.5), 1.0, t.switch_well);
-                    layer_switch(
-                        ui,
-                        &t,
-                        r,
-                        br,
-                        icon,
-                        on,
-                        egui::Id::unique(("av", layer.id.0, i)),
-                        layer.id.0,
-                        name,
-                        true,
-                        &comp,
-                        &app.session.project,
-                        &selected,
-                        &mut actions,
-                    );
-                    app.auto.add(&format!("timeline.layer.{}.{name}", layer.id.0), br, name);
-                }
-                // Label swatch.
-                if vis.label {
-                    let lr = Rect::from_center_size(pos2(cw.label + 10.0, cy), vec2(12.0, 12.0));
-                    lp.rect_filled(lr, 2.0, t.label(layer.label));
-                    let lresp = ui.interact(lr, egui::Id::unique(("label", layer.id.0)), Sense::click());
-                    app.auto.add(&format!("timeline.layer.{}.label", layer.id.0), lr, layer.label.name());
-                    // Click (or right-click) the swatch for the label menu (After Effects).
-                    let pop = egui::Id::unique(("label-pop", layer.id.0));
-                    if lresp.clicked() || lresp.secondary_clicked() {
-                        widgets::open_popup(ui, pop);
-                    }
-                    if let Some(lab) = widgets::label_popup(ui, pop, lr.left_bottom(), layer.label, |l| app.session.prefs.label_name(l), &t) {
-                        actions.push(("edit.label".into(), json!({"layers": edited_layers(layer.id, &selected), "label": lab.name()})));
-                    }
-                }
-                if vis.num {
-                    lp.text(pos2(cw.num + 13.0, cy), Align2::CENTER_CENTER, format!("{}", idx_of(layer.id)), Tokens::ui(11.5), t.text_dim);
-                }
-                layer_cells(app, ui, &lp, &cw, &comp, layer, r, cy, &mut actions);
-                // Row click → select; double-click → rename; drag → reorder. Registered before the
-                // twirl and the name field so those sit on top and get their clicks.
-                let row_x0 = if vis.num { cw.num } else { cw.name + 16.0 };
-                let row_resp = ui.interact(
-                    Rect::from_min_max(pos2(row_x0, r.min.y), pos2(cw.name_end, r.max.y)),
-                    egui::Id::unique(("row", layer.id.0)),
-                    Sense::click_and_drag(),
-                );
-                // Twirl + icon + name.
-                let tw = Rect::from_center_size(pos2(cw.name + 8.0, cy), vec2(14.0, 14.0));
-                let open = app.ui.timeline.open_layers.contains(&layer.id.0);
-                if widgets::twirl(ui, tw, open, egui::Id::unique(("twirl", layer.id.0)), &t).clicked() {
-                    ui_actions.push(UiAct::ToggleLayer(layer.id.0, ui.input(|i| i.modifiers.alt || i.modifiers.command)));
-                }
-                app.auto.add(&format!("timeline.layer.{}.twirl", layer.id.0), tw, "twirl");
-                icons::paint(&lp, Rect::from_center_size(pos2(cw.name + 24.0, cy), vec2(13.0, 13.0)), layer_icon(layer, &app.session.project), t.text_dim);
-                // A guide layer carries a guide mark before its name (After Effects).
-                let name_x = if layer.switches.guide {
-                    let mark = Rect::from_center_size(pos2(cw.name + 40.0, cy), vec2(11.0, 11.0));
-                    icons::paint(&lp, mark, Icon::Grid, t.text_dim);
-                    app.auto.add(&format!("timeline.layer.{}.guide", layer.id.0), mark, "Guide Layer");
-                    cw.name + 50.0
-                } else {
-                    cw.name + 34.0
-                };
-                let name_rect = Rect::from_min_max(pos2(name_x, r.min.y), pos2(cw.name_end - 4.0, r.max.y));
-                let rename_id = egui::Id::unique("tl-rename");
-                let renaming: Option<(u64, String)> = ctx.data(|d| d.get_temp(rename_id));
-                if let Some((rl, mut buf)) = renaming.filter(|(rl, _)| *rl == layer.id.0) {
-                    let mut child = ui.new_child(egui::UiBuilder::new().max_rect(name_rect.shrink2(vec2(0.0, 2.0))));
-                    let er = child.add(egui::TextEdit::singleline(&mut buf).font(Tokens::ui(12.0)).desired_width(name_rect.width()));
-                    app.auto.add(&format!("timeline.layer.{rl}.nameEdit"), er.rect, &buf);
-                    if ctx.data_mut(|d| d.remove_temp::<bool>(rename_focus_id())).unwrap_or(false) {
-                        // Just started: focus the field with the whole name selected.
-                        er.request_focus();
-                        widgets::select_all(&ctx, er.id, &buf);
-                    }
-                    if er.lost_focus() {
-                        if !ui.input(|i| i.key_pressed(egui::Key::Escape)) {
-                            actions.push(("layer.rename".into(), json!({"layer": rl, "name": buf})));
-                        }
-                        ctx.data_mut(|d| d.remove::<(u64, String)>(rename_id));
-                    } else {
-                        ctx.data_mut(|d| d.insert_temp(rename_id, (rl, buf)));
-                    }
-                } else {
-                    // The selected layer's name sits in a light cell with dark text.
-                    let name_col = if is_sel { Color32::from_gray(0x16) } else { t.text };
-                    if is_sel {
-                        let g = lp.layout_no_wrap(display_name(app, layer), Tokens::ui(12.0), name_col);
-                        let cell = Rect::from_min_max(
-                            pos2(name_rect.min.x - 3.0, r.min.y + 1.0),
-                            pos2((name_rect.min.x + g.size().x + 4.0).max(cw.name_end - 4.0).min(cw.name_end - 2.0), r.max.y - 1.0),
-                        );
-                        lp.rect_filled(cell, 0.0, SELECTED_NAME_BG);
-                    }
-                    let lpn = lp.with_clip_rect(name_rect.intersect(lp.clip_rect()));
-                    lpn.text(pos2(name_rect.min.x, cy), Align2::LEFT_CENTER, display_name(app, layer), Tokens::ui(12.0), name_col);
-                }
-                // Locked layers can't be selected or moved (unlock them with the lock switch).
-                let locked = layer.switches.locked;
-                if row_resp.drag_started() && !locked {
-                    // The selected layers move together; an unselected row moves alone.
-                    let moving: Vec<u64> =
-                        if is_sel { comp.layers.iter().filter(|l| selected.contains(&l.id)).map(|l| l.id.0).collect() } else { vec![layer.id.0] };
-                    ctx.data_mut(|d| d.insert_temp(layer_drag_id(), moving));
-                }
-                if row_resp.drag_stopped() {
-                    ctx.data_mut(|d| d.insert_temp(layer_drop_id(), true));
-                }
-                app.auto.add(&format!("timeline.layer.{}.row", layer.id.0), left, &layer.name);
-                if row_resp.clicked() && !locked {
-                    let m = ui.input(|i| i.modifiers);
-                    if let Some(layers) = m.shift.then(|| shift_range(&ctx, cid, &comp, &rows, &selected, layer.id)).flatten() {
-                        actions.push(("layer.select".into(), json!({"layers": layers})));
-                    } else {
-                        actions.push(("layer.select".into(), json!({"layers": [layer.id.0], "toggle": m.command})));
-                        set_anchor(&ctx, cid, layer.id);
-                    }
-                }
-                if row_resp.double_clicked() {
-                    match double_click_action(layer) {
-                        Some(a) => actions.push(a),
-                        None => start_rename(&ctx, layer.id.0, &layer.name),
-                    }
-                }
-                layer_context_menu(&row_resp, &comp, layer, &selected, LayerMenuCaps::of(&app.session.project, layer), &mut app.auto, &mut actions);
-                // Switches.
-                let sws: [(Icon, bool, &str, bool); 8] = [
-                    (Icon::Shy, sw.shy, "shy", switch_applies(layer, "shy", &app.session.project)),
-                    (Icon::Collapse, sw.collapse, "collapse", switch_applies(layer, "collapse", &app.session.project)),
-                    (
-                        Icon::Quality,
-                        sw.quality == effectcraft_engine::project::Quality::Best,
-                        "quality",
-                        switch_applies(layer, "quality", &app.session.project),
-                    ),
-                    (Icon::Fx, sw.effects, "fx", switch_applies(layer, "fx", &app.session.project)),
-                    (
-                        Icon::FrameBlend,
-                        sw.frame_blend != effectcraft_engine::project::FrameBlend::Off,
-                        "frameBlend",
-                        switch_applies(layer, "frameBlend", &app.session.project),
-                    ),
-                    (Icon::MotionBlur, sw.motion_blur, "motionBlur", switch_applies(layer, "motionBlur", &app.session.project)),
-                    (Icon::Adjustment, sw.adjustment, "adjustment", switch_applies(layer, "adjustment", &app.session.project)),
-                    (Icon::Cube, layer.is_3d(), "threeD", switch_applies(layer, "threeD", &app.session.project)),
-                ];
-                for (i, (icon, on, name, applicable)) in sws.into_iter().enumerate() {
-                    if !applicable || !vis.switches {
-                        continue;
-                    }
-                    let br = Rect::from_center_size(pos2(cw.switches + SW * i as f32 + SW / 2.0, cy), vec2(16.0, 16.0));
-                    lp.rect_filled(br.shrink(1.0), 1.0, t.switch_well);
-                    layer_switch(
-                        ui,
-                        &t,
-                        r,
-                        br,
-                        icon,
-                        on,
-                        egui::Id::unique(("sw", layer.id.0, i)),
-                        layer.id.0,
-                        name,
-                        false,
-                        &comp,
-                        &app.session.project,
-                        &selected,
-                        &mut actions,
-                    );
-                    app.auto.add(&format!("timeline.layer.{}.switch.{name}", layer.id.0), br, name);
-                }
-                // Modes.
-                if app.ui.timeline.show_modes && layer.source.is_av() {
-                    let mr = Rect::from_min_size(pos2(cw.mode + 2.0, cy - 9.0), vec2(80.0, 18.0));
-                    let mresp = widgets::dropdown(ui, mr, layer.blend_mode.label(), &t, egui::Id::unique(("mode", layer.id.0)));
-                    app.auto.add(&format!("timeline.layer.{}.mode", layer.id.0), mr, "Mode");
-                    let pop = egui::Id::unique(("mode-pop", layer.id.0));
-                    if mresp.clicked() {
-                        widgets::open_popup(ui, pop);
-                    }
-                    let opts: Vec<String> = BlendMode::ALL
-                        .iter()
-                        .flat_map(|m| if m.ends_group() { vec![m.label().to_string(), "-".to_string()] } else { vec![m.label().to_string()] })
-                        .collect();
-                    if let Some(i) = widgets::popup_menu(ui, pop, mr.left_bottom(), &opts, opts.iter().position(|o| o == layer.blend_mode.label())) {
-                        actions.push(("layer.setBlendMode".into(), json!({"layers": mode_targets(&comp, layer.id, &selected), "mode": opts[i]})));
-                    }
-                    let tr = Rect::from_center_size(pos2(cw.mode + 76.0 + 6.0, cy), vec2(14.0, 14.0));
-                    app.auto.add(&format!("timeline.layer.{}.preserveTransparency", layer.id.0), tr, "Preserve Transparency");
-                    if widgets::checkbox(ui, tr, layer.preserve_transparency, &t, egui::Id::unique(("pt", layer.id.0))).clicked() {
-                        // The click gives the selection the state the clicked row toggles to,
-                        // whatever the first selected layer's value (as the switches do).
-                        actions.push((
-                            "layer.setSwitch".into(),
-                            json!({
-                                "layers": mode_targets(&comp, layer.id, &selected),
-                                "switch": "preserveTransparency",
-                                "value": !layer.preserve_transparency
-                            }),
-                        ));
-                    }
-                    // Track matte: layer picker + kind.
-                    let mr = Rect::from_min_size(pos2(cw.trkmat + 2.0, cy - 9.0), vec2(104.0, 18.0));
-                    let label = match layer.track_matte {
-                        Some(m) => comp.layer(m.layer).map(|l| format!("{} {}", idx_of(l.id), l.name)).unwrap_or("None".into()),
-                        None => "No Track Matte".into(),
-                    };
-                    // The cell is too narrow for the mode as well: it is in the tooltip and ticked in the menu.
-                    let tip = layer.track_matte.map(|m| format!("{label} · {}", crate::i18n::tr(m.kind.label())));
-                    let tresp = widgets::dropdown_tip(ui, mr, &label, tip.as_deref(), &t, egui::Id::unique(("trkmat", layer.id.0)));
-                    app.auto.add(&format!("timeline.layer.{}.trackMatte", layer.id.0), mr, "Track Matte");
-                    let pop = egui::Id::unique(("trk-pop", layer.id.0));
-                    if tresp.clicked() {
-                        widgets::open_popup(ui, pop);
-                    }
-                    // The menu lists every layer: built only while it is open (per visible row
-                    // it made a big comp's timeline quadratic).
-                    let mut opts = vec!["No Track Matte".to_string(), "-".to_string()];
-                    let mut candidates: Vec<&Layer> = vec![];
-                    if widgets::popup_is_open(ui, pop) {
-                        for (i, l) in comp.layers.iter().enumerate().filter(|(_, l)| l.id != layer.id && l.source.is_av()) {
-                            opts.push(format!("{}. {}", i + 1, l.name));
-                            candidates.push(l);
-                        }
-                        opts.push("-".into());
-                        for k in MatteKind::ALL {
-                            opts.push(k.label().into());
-                        }
-                    }
-                    let current = layer.track_matte.and_then(|m| opts.iter().position(|o| o == m.kind.label()));
-                    if let Some(i) = widgets::popup_menu(ui, pop, mr.left_bottom(), &opts, current) {
-                        let ids: Vec<LayerId> = candidates.iter().map(|l| l.id).collect();
-                        if let Some(a) = opts.get(i).and_then(|o| track_matte_pick(layer, &ids, i, o)) {
-                            actions.push(a);
-                        }
-                    }
-                    if layer.track_matte.is_some() {
-                        let kr = Rect::from_center_size(pos2(mr.max.x - 26.0, cy), vec2(10.0, 10.0));
-                        let _ = kr;
-                    }
-                }
-                // Parent.
-                if vis.parent {
-                    pick_whip(
-                        app,
-                        ui,
-                        &lp,
-                        Rect::from_center_size(pos2(cw.parent + 9.0, cy), vec2(15.0, 15.0)),
-                        (WHIP_PARENT, layer.id.0, 0),
-                        &format!("timeline.layer.{}.pickWhip", layer.id.0),
-                        "Parent pick whip",
-                        crate::i18n::tr("Parent pick whip: drag onto a layer"),
-                    );
-                    let pr_rect = Rect::from_min_size(pos2(cw.parent + 20.0, cy - 9.0), vec2(94.0, 18.0));
-                    let plabel = layer.parent.and_then(|p| comp.layer(p)).map(|l| format!("{}. {}", idx_of(l.id), l.name)).unwrap_or_else(|| "None".into());
-                    let presp = widgets::dropdown(ui, pr_rect, &plabel, &t, egui::Id::unique(("parent", layer.id.0)));
-                    app.auto.add(&format!("timeline.layer.{}.parent", layer.id.0), pr_rect, "Parent");
-                    let pop = egui::Id::unique(("par-pop", layer.id.0));
-                    if presp.clicked() {
-                        widgets::open_popup(ui, pop);
-                    }
-                    let mut cands: Vec<&Layer> = vec![];
-                    let mut popts = vec!["None".to_string(), "-".to_string()];
-                    if widgets::popup_is_open(ui, pop) {
-                        for (i, l) in comp.layers.iter().enumerate().filter(|(_, l)| l.id != layer.id) {
-                            popts.push(format!("{}. {}", i + 1, l.name));
-                            cands.push(l);
-                        }
-                    }
-                    if let Some(i) = widgets::popup_menu(ui, pop, pr_rect.left_bottom(), &popts, None) {
-                        let par = if i == 0 { serde_json::Value::Null } else { json!(cands[i - 2].id.0) };
-                        actions.push(("layer.setParent".into(), json!({"layers": [layer.id.0], "parent": par})));
-                    }
-                }
-                // Layer bar.
-                ui.set_clip_rect(right_clip);
-                if !graph_on {
-                    let x_in = tm.x(layer.in_point.seconds());
-                    let x_out = tm.x(layer.out_point.seconds());
-                    let bar = Rect::from_min_max(pos2(x_in, r.min.y + 1.0), pos2(x_out, r.max.y - 1.0));
-                    let lc = t.label(layer.label);
-                    let fill = bar_color(lc, is_sel);
-                    gp.rect_filled(bar, 0.0, fill);
-                    if is_sel {
-                        gp.rect_stroke(bar, 0.0, Stroke::new(1.0, Color32::from_white_alpha(90)), StrokeKind::Inside);
-                    }
-                    // Source extent (e.g. trimmed footage) shown faint.
-                    if let LayerSource::Footage { .. } | LayerSource::Comp { .. } = layer.source
-                        && let Some(d) = layer.source.item().and_then(|i| app.session.project.item(i)).and_then(|i| i.duration())
-                    {
-                        let xs = tm.x(layer.start_time.seconds());
-                        let xe = tm.x(layer.comp_time(d).seconds());
-                        let ghost = Rect::from_min_max(pos2(xs.min(xe), r.min.y + 9.0), pos2(xs.max(xe), r.max.y - 9.0));
-                        gp.rect_filled(ghost, 1.0, lc.gamma_multiply(0.18));
-                        // The bar past the source's end (its last frame held) or before its start
-                        // is striped, so the source's own span shows (#290). Time remapping
-                        // decides what shows there itself.
-                        if layer.props.get("timeRemap").is_none() {
-                            for (side, part) in [
-                                ("beforeSource", Rect::from_min_max(bar.min, pos2(ghost.min.x, bar.max.y))),
-                                ("afterSource", Rect::from_min_max(pos2(ghost.max.x, bar.min.y), bar.max)),
-                            ] {
-                                if part.width() >= 1.0 {
-                                    stripes(&gp, part, lc);
-                                    app.auto.add(&format!("timeline.layer.{}.bar.{side}", layer.id.0), part, "Past the source");
-                                }
-                            }
-                        }
-                        // Dragging the source bar outside the in/out span slips the source.
-                        for (side, gr) in [
-                            ("l", Rect::from_min_max(ghost.min, pos2(bar.min.x, ghost.max.y))),
-                            ("r", Rect::from_min_max(pos2(bar.max.x, ghost.min.y), ghost.max)),
-                        ] {
-                            if gr.width() < 2.0 {
-                                continue;
-                            }
-                            let gresp = ui
-                                .interact(gr, egui::Id::unique(("ghost", side, layer.id.0)), Sense::click_and_drag())
-                                .on_hover_text(crate::i18n::tr("Drag to slip the source"));
-                            // Outside the bar it is empty track area: a plain click deselects.
-                            if gresp.clicked() && !ui.input(|i| i.modifiers.shift || i.modifiers.command) {
-                                actions.push(("layer.select".into(), json!({"layers": []})));
-                            }
-                            app.auto.add(&format!("timeline.layer.{}.source{}", layer.id.0, side), gr, "Slip");
-                            if gresp.hovered() || gresp.dragged() {
-                                ctx.set_cursor_icon(egui::CursorIcon::ResizeHorizontal);
-                            }
-                            let acc_id = egui::Id::unique(("slip-acc", layer.id.0));
-                            if gresp.dragged() {
-                                let mut acc: f32 = ctx.data(|d| d.get_temp(acc_id).unwrap_or(0.0));
-                                acc += gresp.drag_delta().x;
-                                let frames = ((acc as f64 / pps) / fd).trunc() as i64;
-                                if frames != 0 {
-                                    acc -= (frames as f64 * fd * pps) as f32;
-                                    actions.push((
-                                        "layer.slip".into(),
-                                        json!({"layers": [layer.id.0], "frames": frames, "merge": format!("slip-{}", layer.id.0)}),
-                                    ));
-                                }
-                                ctx.data_mut(|d| d.insert_temp(acc_id, acc));
-                            }
-                            if gresp.drag_stopped() {
-                                ctx.data_mut(|d| d.remove::<f32>(acc_id));
-                                ui_actions.push(UiAct::EndMerge);
-                            }
-                        }
-                    }
-                    app.auto.add(&format!("timeline.layer.{}.bar", layer.id.0), bar, &layer.name);
-                    // Interactions: move body, trim edges.
-                    let (body_r, in_r, out_r) = trim_zones(bar);
-                    let body = ui.interact(body_r, egui::Id::unique(("bar", layer.id.0)), Sense::click_and_drag());
-                    let lin = ui.interact(in_r, egui::Id::unique(("bar-in", layer.id.0)), Sense::drag());
-                    let lout = ui.interact(out_r, egui::Id::unique(("bar-out", layer.id.0)), Sense::drag());
-                    app.auto.add(&format!("timeline.layer.{}.bar.in", layer.id.0), in_r, "Trim In");
-                    app.auto.add(&format!("timeline.layer.{}.bar.out", layer.id.0), out_r, "Trim Out");
-                    if lin.hovered() || lout.hovered() || lin.dragged() || lout.dragged() {
-                        trim_cursor(&ctx);
-                    }
-                    if body.double_clicked()
-                        && let Some(a) = double_click_action(layer)
-                    {
-                        actions.push(a);
-                    }
-                    let shift = ui.input(|i| i.modifiers.shift);
-                    if let Some(layers) = (body.clicked() && shift).then(|| shift_range(&ctx, cid, &comp, &rows, &selected, layer.id)).flatten() {
-                        // Shift-click: the layers from the last one clicked to this one, as in
-                        // the layer outline.
-                        actions.push(("layer.select".into(), json!({"layers": layers})));
-                    } else {
-                        if (body.clicked() || body.drag_started()) && !is_sel {
-                            actions.push(("layer.select".into(), json!({"layers": [layer.id.0], "add": shift})));
-                        }
-                        if (body.clicked() || body.drag_started()) && !shift {
-                            set_anchor(&ctx, cid, layer.id);
-                        }
-                    }
-                    layer_context_menu(&body, &comp, layer, &selected, LayerMenuCaps::of(&app.session.project, layer), &mut app.auto, &mut actions);
-                    let drag_key = format!("bar-{}", layer.id.0);
-                    // Ctrl/Cmd+Alt dragging a selected bar: Quick Offset (#1012), chosen as the
-                    // drag starts and followed below the rows until the button is released.
-                    let mods = ui.input(|i| i.modifiers);
-                    if body.drag_started()
-                        && is_sel
-                        && mods.command
-                        && mods.alt
-                        && let Some(n) = quick_offset_layers(&comp, selected.iter().copied())
-                        && let Some(p) = ctx.input(|i| i.pointer.press_origin())
-                    {
-                        ctx.data_mut(|d| d.insert_temp(quick_bar_id(), QuickBar { layer: layer.id, origin_x: p.x, layers: n, applied: 0 }));
-                    }
-                    let quick = ctx.data(|d| d.get_temp::<QuickBar>(quick_bar_id())).is_some_and(|q| q.layer == layer.id);
-                    for (resp, kind) in [(&body, "move"), (&lin, "in"), (&lout, "out")] {
-                        if kind == "move" && quick {
-                            continue;
-                        }
-                        if resp.dragged() {
-                            let acc_id = egui::Id::unique(("bar-acc", layer.id.0, kind));
-                            let mut acc: f32 = ctx.data(|d| d.get_temp(acc_id).unwrap_or(0.0));
-                            acc += resp.drag_delta().x;
-                            let frames = ((acc as f64 / pps) / fd).trunc() as i64;
-                            if frames != 0 {
-                                acc -= (frames as f64 * fd * pps) as f32;
-                                let d = frames as f64 * fd;
-                                // Moving or trimming a selected layer acts on the whole
-                                // selection; each layer trims from its own in/out point.
-                                let targets = if is_sel { json!(selected.iter().map(|l| l.0).collect::<Vec<_>>()) } else { json!([layer.id.0]) };
-                                let params = match kind {
-                                    "move" => json!({"layers": targets, "delta": d, "merge": drag_key}),
-                                    "in" => json!({"layers": targets, "inDelta": d, "merge": drag_key}),
-                                    _ => json!({"layers": targets, "outDelta": d, "merge": drag_key}),
-                                };
-                                actions.push(("layer.timing".into(), params));
-                            }
-                            ctx.data_mut(|d| d.insert_temp(acc_id, acc));
-                        }
-                        if resp.drag_stopped() {
-                            ctx.data_mut(|d| d.remove::<f32>(egui::Id::unique(("bar-acc", layer.id.0, kind))));
-                            ui_actions.push(UiAct::EndMerge);
-                        }
-                    }
-                    // Markers on the layer (drag, Alt-drag duration, Cmd-click delete, dialog).
-                    let gclip = rows_rect.intersect(Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max));
-                    super::markers_ui::layer_markers(app, ui, gclip, &comp, layer, tm, r);
-                }
+        lp.rect_filled(br.shrink(0.5), 1.0, t.switch_well);
+        layer_switch(
+            ui,
+            &t,
+            &SwitchSpec { row: r, br, icon, on, id: egui::Id::unique(("av", layer.id.0, i)), layer: layer.id.0, name, others: true },
+            &comp,
+            &app.session.project,
+            selected,
+            &mut *actions,
+        );
+        app.auto.add(&format!("timeline.layer.{}.{name}", layer.id.0), br, name);
+    }
+}
+
+/// The label swatch and its colour menu.
+fn layer_label_swatch(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let vis = g.tl.vis;
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let selected = &g.selected;
+    let layer = rc.layer;
+    let cy = rc.cy;
+    // Label swatch.
+    if vis.label {
+        let lr = Rect::from_center_size(pos2(cw.label + 10.0, cy), vec2(12.0, 12.0));
+        lp.rect_filled(lr, 2.0, t.label(layer.label));
+        let lresp = ui.interact(lr, egui::Id::unique(("label", layer.id.0)), Sense::click());
+        app.auto.add(&format!("timeline.layer.{}.label", layer.id.0), lr, layer.label.name());
+        // Click (or right-click) the swatch for the label menu (After Effects).
+        let pop = egui::Id::unique(("label-pop", layer.id.0));
+        if lresp.clicked() || lresp.secondary_clicked() {
+            widgets::open_popup(ui, pop);
+        }
+        if let Some(lab) = widgets::label_popup(ui, pop, lr.left_bottom(), layer.label, |l| app.session.prefs.label_name(l), &t) {
+            actions.push(("edit.label".into(), json!({"layers": edited_layers(layer.id, selected), "label": lab.name()})));
+        }
+    }
+}
+
+fn layer_number_and_cells(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let vis = g.tl.vis;
+    let comp = g.tl.comp.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let layer = rc.layer;
+    let cy = rc.cy;
+    if vis.num {
+        lp.text(pos2(cw.num + 13.0, cy), Align2::CENTER_CENTER, format!("{}", comp.index_of(layer.id).unwrap_or(0)), Tokens::ui(11.5), t.text_dim);
+    }
+    layer_cells(app, ui, &lp, cw, &comp, rc, &mut *actions);
+}
+
+/// The row's click target, twirl, icon and guide mark; returns the row response and the name's x.
+fn layer_twirl_and_icon(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) -> (egui::Response, f32) {
+    let t = g.tl.t;
+    let vis = g.tl.vis;
+    let cw = &g.tl.cw;
+    let lp = g.lp.clone();
+    let ui_actions = &mut g.ui_actions;
+    let layer = rc.layer;
+    let r = rc.r;
+    let cy = rc.cy;
+    // Row click → select; double-click → rename; drag → reorder. Registered before the
+    // twirl and the name field so those sit on top and get their clicks.
+    let row_x0 = if vis.num { cw.num } else { cw.name + 16.0 };
+    let row_resp =
+        ui.interact(Rect::from_min_max(pos2(row_x0, r.min.y), pos2(cw.name_end, r.max.y)), egui::Id::unique(("row", layer.id.0)), Sense::click_and_drag());
+    // Twirl + icon + name.
+    let tw = Rect::from_center_size(pos2(cw.name + 8.0, cy), vec2(14.0, 14.0));
+    let open = app.ui.timeline.open_layers.contains(&layer.id.0);
+    if widgets::twirl(ui, tw, open, egui::Id::unique(("twirl", layer.id.0)), &t).clicked() {
+        ui_actions.push(UiAct::ToggleLayer(layer.id.0, ui.input(|i| i.modifiers.alt || i.modifiers.command)));
+    }
+    app.auto.add(&format!("timeline.layer.{}.twirl", layer.id.0), tw, "twirl");
+    icons::paint(&lp, Rect::from_center_size(pos2(cw.name + 24.0, cy), vec2(13.0, 13.0)), layer_icon(layer, &app.session.project), t.text_dim);
+    // A guide layer carries a guide mark before its name (After Effects).
+    let name_x = if layer.switches.guide {
+        let mark = Rect::from_center_size(pos2(cw.name + 40.0, cy), vec2(11.0, 11.0));
+        icons::paint(&lp, mark, Icon::Grid, t.text_dim);
+        app.auto.add(&format!("timeline.layer.{}.guide", layer.id.0), mark, "Guide Layer");
+        cw.name + 50.0
+    } else {
+        cw.name + 34.0
+    };
+    (row_resp, name_x)
+}
+
+/// The layer name: the rename field or the (selected) name cell.
+fn layer_name(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, name_x: f32) {
+    let t = g.tl.t;
+    let ctx = g.tl.ctx.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let layer = rc.layer;
+    let r = rc.r;
+    let cy = rc.cy;
+    let is_sel = rc.is_sel;
+    let name_rect = Rect::from_min_max(pos2(name_x, r.min.y), pos2(cw.name_end - 4.0, r.max.y));
+    let rename_id = egui::Id::unique("tl-rename");
+    let renaming: Option<(u64, String)> = ctx.data(|d| d.get_temp(rename_id));
+    if let Some((rl, mut buf)) = renaming.filter(|(rl, _)| *rl == layer.id.0) {
+        let mut child = ui.new_child(egui::UiBuilder::new().max_rect(name_rect.shrink2(vec2(0.0, 2.0))));
+        let er = child.add(egui::TextEdit::singleline(&mut buf).font(Tokens::ui(12.0)).desired_width(name_rect.width()));
+        app.auto.add(&format!("timeline.layer.{rl}.nameEdit"), er.rect, &buf);
+        if ctx.data_mut(|d| d.remove_temp::<bool>(rename_focus_id())).unwrap_or(false) {
+            // Just started: focus the field with the whole name selected.
+            er.request_focus();
+            widgets::select_all(&ctx, er.id, &buf);
+        }
+        if er.lost_focus() {
+            if !ui.input(|i| i.key_pressed(egui::Key::Escape)) {
+                actions.push(("layer.rename".into(), json!({"layer": rl, "name": buf})));
             }
-            RowKind::Group { uid, name, open, has_children, fx, eye } => {
-                // The row draws an effect's name in the interface language (#821); `name` stays
-                // the property tree's, which the automation labels below keep. Any other group
-                // (a mask, a shape group, a layer style) draws its own name.
-                let group = layer.props.find_group(*uid);
-                let shown = match group.and_then(|g| match &g.kind {
-                    GroupKind::Effect { effect } => Some(effect.as_str()),
-                    _ => None,
-                }) {
-                    Some(effect) => crate::i18n::effects::group(effect, name),
-                    None => name.clone(),
-                };
-                // Selected groups (an effect, a mask, a shape group…) highlight like selected
-                // property rows.
-                let sel_group = app.session.state.selected_props.contains(&(layer.id, *uid));
-                lp.rect_filled(
-                    left,
-                    0.0,
-                    if sel_group {
-                        t.row_selected
-                    } else if ri % 2 == 0 {
-                        t.row
-                    } else {
-                        t.row_alt
-                    },
-                );
-                gp.rect_filled(Rect::from_min_max(pos2(graph_x0, r.min.y), r.max), 0.0, t.tl_bg);
-                // An effect's colour label (26.5): the same bar the Effect Controls header wears,
-                // on the row's left edge.
-                if let Some(lab) =
-                    group.filter(|g| matches!(g.kind, GroupKind::Effect { .. })).and_then(|g| g.label).filter(|l| *l != effectcraft_engine::color::Label::None)
-                {
-                    let [lr, lg, lb] = app.session.prefs.label_rgb(lab);
-                    let bar = Rect::from_min_size(left.min, vec2(4.0, left.height()));
-                    lp.rect_filled(bar, 0.0, Color32::from_rgb(lr, lg, lb));
-                    app.auto.add(&format!("timeline.group.{uid}.label"), bar, &app.session.prefs.label_name(lab));
-                }
-                let indent = cw.name + 6.0 + 14.0 * row.depth as f32;
-                if *has_children {
-                    let tw = Rect::from_center_size(pos2(indent, cy), vec2(13.0, 13.0));
-                    if widgets::twirl(ui, tw, *open, egui::Id::unique(("gtw", uid)), &t).clicked() {
-                        // Alt/Cmd-click twirls the whole tree under the group (as on a layer).
-                        ui_actions.push(UiAct::ToggleGroup(layer.id.0, *uid, ui.input(|i| i.modifiers.alt || i.modifiers.command)));
-                    }
-                    app.auto.add(&format!("timeline.group.{uid}.twirl"), tw, name);
-                }
-                if let Some(en) = fx {
-                    let fr_ = Rect::from_center_size(pos2(cw.switches + SW * 3.0 + SW / 2.0, cy), vec2(16.0, 16.0));
-                    if widgets::icon_toggle(ui, fr_, Icon::Fx, *en, &t, egui::Id::unique(("gfx", uid)), Sense::click()).clicked() {
-                        actions.push(("effect.toggle".into(), json!({"layer": layer.id.0, "effect": uid})));
-                    }
-                    app.auto.add(&format!("timeline.group.{uid}.fx"), fr_, name);
-                }
-                if let Some(en) = eye {
-                    // Layer style eye switch in the A/V column, like AE.
-                    let er = Rect::from_center_size(pos2(cw.av + 10.0, cy), vec2(15.0, 15.0));
-                    lp.rect_stroke(er.shrink(1.5), 2.0, Stroke::new(1.0, t.separator), StrokeKind::Inside);
-                    if widgets::icon_toggle(ui, er, Icon::Eye, *en, &t, egui::Id::unique(("geye", uid)), Sense::click()).clicked() {
-                        actions.push(("layer.style.toggle".into(), json!({"layer": layer.id.0, "style": uid})));
-                    }
-                    app.auto.add(&format!("timeline.group.{uid}.eye"), er, name);
-                }
-                let group_edit: Option<(u64, u64, String)> = ctx.data(|d| d.get_temp(group_rename_id()));
-                if let Some((_, _, mut buf)) = group_edit.filter(|(rl, ru, _)| *rl == layer.id.0 && ru == uid) {
-                    let field = Rect::from_min_max(pos2(indent + 8.0, r.min.y + 2.0), pos2((cw.switches - 4.0).max(indent + 60.0), r.max.y - 2.0));
-                    let mut child = ui.new_child(egui::UiBuilder::new().max_rect(field));
-                    let er = child.add(egui::TextEdit::singleline(&mut buf).font(Tokens::ui(12.0)).desired_width(field.width()));
-                    app.auto.add(&format!("timeline.group.{uid}.nameEdit"), er.rect, &buf);
-                    if ctx.data_mut(|d| d.remove_temp::<bool>(rename_focus_id())).unwrap_or(false) {
-                        er.request_focus();
-                        widgets::select_all(&ctx, er.id, &buf);
-                    }
-                    if er.lost_focus() {
-                        if !ui.input(|i| i.key_pressed(egui::Key::Escape)) && !buf.trim().is_empty() && buf != *name {
-                            actions.push(("prop.renameGroup".into(), json!({"layer": layer.id.0, "prop": uid, "name": buf})));
-                        }
-                        ctx.data_mut(|d| d.remove::<(u64, u64, String)>(group_rename_id()));
-                    } else {
-                        ctx.data_mut(|d| d.insert_temp(group_rename_id(), (layer.id.0, *uid, buf)));
-                    }
-                } else {
-                    lp.text(pos2(indent + 10.0, cy), Align2::LEFT_CENTER, &shown, Tokens::ui(12.0), t.text);
-                }
-                text_anim_popups(app, ui, &lp, layer, *uid, cw.switches, cy, &mut actions);
-                shape_add_popup(app, ui, &lp, layer, *uid, cw.switches, cy, &mut actions);
-                if *uid == GEOM_BIT | layer.id.0 {
-                    let lr = lp.text(pos2(cw.switches + 6.0, cy), Align2::LEFT_CENTER, crate::i18n::tr("Change Renderer…"), Tokens::ui(11.5), t.accent);
-                    let resp = ui
-                        .interact(lr, egui::Id::unique(("tl-change-renderer", layer.id.0)), Sense::click())
-                        .on_hover_text(crate::i18n::tr("Composition Settings ▸ 3D Renderer"));
-                    if resp.hovered() {
-                        ctx.set_cursor_icon(egui::CursorIcon::PointingHand);
-                    }
-                    app.auto.add(&format!("timeline.layer.{}.changeRenderer", layer.id.0), lr, "Change Renderer…");
-                    if resp.clicked() {
-                        ui_actions.push(UiAct::ChangeRenderer);
-                    }
-                }
-                dash_buttons(app, ui, &lp, layer, *uid, cw.switches, cy, &mut actions);
-                // Mask mode + inverted inline.
-                if let Some(g) = layer.props.find_group(*uid)
-                    && let GroupKind::Mask { mode, inverted, .. } = g.kind
-                {
-                    let mr = Rect::from_min_size(pos2(cw.switches + 4.0, cy - 9.0), vec2(80.0, 18.0));
-                    let pop = egui::Id::unique(("maskmode", uid));
-                    if widgets::dropdown(ui, mr, mode.label(), &t, egui::Id::unique(("mm", uid))).clicked() {
-                        widgets::open_popup(ui, pop);
-                    }
-                    let opts: Vec<String> = effectcraft_engine::project::MaskMode::ALL.iter().map(|m| m.label().to_string()).collect();
-                    if let Some(i) = widgets::popup_menu(ui, pop, mr.left_bottom(), &opts, None) {
-                        actions.push(("layer.setMask".into(), json!({"layer": layer.id.0, "mask": uid, "mode": opts[i]})));
-                    }
-                    let ir = Rect::from_min_size(pos2(mr.max.x + 8.0, cy - 8.0), vec2(16.0, 16.0));
-                    if widgets::checkbox(ui, ir, inverted, &t, egui::Id::unique(("minv", uid))).clicked() {
-                        actions.push(("layer.setMask".into(), json!({"layer": layer.id.0, "mask": uid, "inverted": !inverted})));
-                    }
-                    lp.text(pos2(ir.max.x + 4.0, cy), Align2::LEFT_CENTER, crate::i18n::tr("Inverted"), Tokens::ui(11.0), t.text_dim);
-                }
-                let gr_rect = Rect::from_min_max(pos2(indent + 8.0, r.min.y), pos2(cw.switches, r.max.y));
-                let gr = ui.interact(gr_rect, egui::Id::unique(("grow", uid)), Sense::click());
-                app.auto.add(&format!("timeline.group.{uid}.name"), gr_rect, name);
-                if gr.clicked() && uid & (WAVE_BIT | GEOM_BIT) == 0 {
-                    actions.push(("prop.select".into(), json!({"layer": layer.id.0, "prop": uid, "selectKeys": false})));
-                }
-                if gr.double_clicked() {
-                    if fx.is_some() {
-                        // An effect's name: open it in Effect Controls (as in After Effects).
-                        actions.push(("layer.select".into(), json!({"layers": [layer.id.0]})));
-                        actions.push(("prop.select".into(), json!({"layer": layer.id.0, "prop": uid, "selectKeys": false})));
-                        actions.push(("window.panel".into(), json!({"panel": "EffectControls"})));
-                    } else {
-                        ui_actions.push(UiAct::ToggleGroup(layer.id.0, *uid, false));
-                    }
-                }
+            ctx.data_mut(|d| d.remove::<(u64, String)>(rename_id));
+        } else {
+            ctx.data_mut(|d| d.insert_temp(rename_id, (rl, buf)));
+        }
+    } else {
+        // The selected layer's name sits in a light cell with dark text.
+        let name_col = if is_sel { Color32::from_gray(0x16) } else { t.text };
+        if is_sel {
+            let g = lp.layout_no_wrap(display_name(app, layer), Tokens::ui(12.0), name_col);
+            let cell = Rect::from_min_max(
+                pos2(name_rect.min.x - 3.0, r.min.y + 1.0),
+                pos2((name_rect.min.x + g.size().x + 4.0).max(cw.name_end - 4.0).min(cw.name_end - 2.0), r.max.y - 1.0),
+            );
+            lp.rect_filled(cell, 0.0, SELECTED_NAME_BG);
+        }
+        let lpn = lp.with_clip_rect(name_rect.intersect(lp.clip_rect()));
+        lpn.text(pos2(name_rect.min.x, cy), Align2::LEFT_CENTER, display_name(app, layer), Tokens::ui(12.0), name_col);
+    }
+}
+
+/// Row click, drag, double-click and context menu.
+fn layer_row_actions(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, row_resp: &egui::Response) {
+    let cid = g.tl.cid;
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
+    let rows = &g.tl.rows;
+    let actions = &mut g.tl.actions;
+    let selected = &g.selected;
+    let layer = rc.layer;
+    let left = rc.left;
+    let is_sel = rc.is_sel;
+    // Locked layers can't be selected or moved (unlock them with the lock switch).
+    let locked = layer.switches.locked;
+    if row_resp.drag_started() && !locked {
+        // The selected layers move together; an unselected row moves alone.
+        let moving: Vec<u64> = if is_sel { comp.layers.iter().filter(|l| selected.contains(&l.id)).map(|l| l.id.0).collect() } else { vec![layer.id.0] };
+        ctx.data_mut(|d| d.insert_temp(layer_drag_id(), moving));
+    }
+    if row_resp.drag_stopped() {
+        ctx.data_mut(|d| d.insert_temp(layer_drop_id(), true));
+    }
+    app.auto.add(&format!("timeline.layer.{}.row", layer.id.0), left, &layer.name);
+    if row_resp.clicked() && !locked {
+        let m = ui.input(|i| i.modifiers);
+        if let Some(layers) = m.shift.then(|| shift_range(&ctx, cid, &comp, rows, selected, layer.id)).flatten() {
+            actions.push(("layer.select".into(), json!({"layers": layers})));
+        } else {
+            actions.push(("layer.select".into(), json!({"layers": [layer.id.0], "toggle": m.command})));
+            set_anchor(&ctx, cid, layer.id);
+        }
+    }
+    if row_resp.double_clicked() {
+        match double_click_action(layer) {
+            Some(a) => actions.push(a),
+            None => start_rename(&ctx, layer.id.0, &layer.name),
+        }
+    }
+    layer_context_menu(row_resp, &comp, layer, selected, LayerMenuCaps::of(&app.session.project, layer), &mut app.auto, &mut *actions);
+}
+
+/// The eight layer switches.
+fn layer_switches(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let vis = g.tl.vis;
+    let comp = g.tl.comp.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let selected = &g.selected;
+    let layer = rc.layer;
+    let r = rc.r;
+    let cy = rc.cy;
+    let sw = &layer.switches;
+    let sws: [(Icon, bool, &str, bool); 8] = [
+        (Icon::Shy, sw.shy, "shy", switch_applies(layer, "shy", &app.session.project)),
+        (Icon::Collapse, sw.collapse, "collapse", switch_applies(layer, "collapse", &app.session.project)),
+        (Icon::Quality, sw.quality == effectcraft_engine::project::Quality::Best, "quality", switch_applies(layer, "quality", &app.session.project)),
+        (Icon::Fx, sw.effects, "fx", switch_applies(layer, "fx", &app.session.project)),
+        (
+            Icon::FrameBlend,
+            sw.frame_blend != effectcraft_engine::project::FrameBlend::Off,
+            "frameBlend",
+            switch_applies(layer, "frameBlend", &app.session.project),
+        ),
+        (Icon::MotionBlur, sw.motion_blur, "motionBlur", switch_applies(layer, "motionBlur", &app.session.project)),
+        (Icon::Adjustment, sw.adjustment, "adjustment", switch_applies(layer, "adjustment", &app.session.project)),
+        (Icon::Cube, layer.is_3d(), "threeD", switch_applies(layer, "threeD", &app.session.project)),
+    ];
+    for (i, (icon, on, name, applicable)) in sws.into_iter().enumerate() {
+        if !applicable || !vis.switches {
+            continue;
+        }
+        let br = Rect::from_center_size(pos2(cw.switches + SW * i as f32 + SW / 2.0, cy), vec2(16.0, 16.0));
+        lp.rect_filled(br.shrink(1.0), 1.0, t.switch_well);
+        layer_switch(
+            ui,
+            &t,
+            &SwitchSpec { row: r, br, icon, on, id: egui::Id::unique(("sw", layer.id.0, i)), layer: layer.id.0, name, others: false },
+            &comp,
+            &app.session.project,
+            selected,
+            &mut *actions,
+        );
+        app.auto.add(&format!("timeline.layer.{}.switch.{name}", layer.id.0), br, name);
+    }
+}
+
+/// The blend mode dropdown and Preserve Transparency.
+fn layer_mode_cell(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let comp = g.tl.comp.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let selected = &g.selected;
+    let layer = rc.layer;
+    let cy = rc.cy;
+    let mr = Rect::from_min_size(pos2(cw.mode + 2.0, cy - 9.0), vec2(80.0, 18.0));
+    let mresp = widgets::dropdown(ui, mr, layer.blend_mode.label(), &t, egui::Id::unique(("mode", layer.id.0)));
+    app.auto.add(&format!("timeline.layer.{}.mode", layer.id.0), mr, "Mode");
+    let pop = egui::Id::unique(("mode-pop", layer.id.0));
+    if mresp.clicked() {
+        widgets::open_popup(ui, pop);
+    }
+    let opts: Vec<String> =
+        BlendMode::ALL.iter().flat_map(|m| if m.ends_group() { vec![m.label().to_string(), "-".to_string()] } else { vec![m.label().to_string()] }).collect();
+    if let Some(i) = widgets::popup_menu(ui, pop, mr.left_bottom(), &opts, opts.iter().position(|o| o == layer.blend_mode.label())) {
+        actions.push(("layer.setBlendMode".into(), json!({"layers": mode_targets(&comp, layer.id, selected), "mode": opts[i]})));
+    }
+    let tr = Rect::from_center_size(pos2(cw.mode + 76.0 + 6.0, cy), vec2(14.0, 14.0));
+    app.auto.add(&format!("timeline.layer.{}.preserveTransparency", layer.id.0), tr, "Preserve Transparency");
+    if widgets::checkbox(ui, tr, layer.preserve_transparency, &t, egui::Id::unique(("pt", layer.id.0))).clicked() {
+        // The click gives the selection the state the clicked row toggles to,
+        // whatever the first selected layer's value (as the switches do).
+        actions.push((
+            "layer.setSwitch".into(),
+            json!({
+                "layers": mode_targets(&comp, layer.id, selected),
+                "switch": "preserveTransparency",
+                "value": !layer.preserve_transparency
+            }),
+        ));
+    }
+}
+
+/// The track matte picker.
+fn layer_matte_cell(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let comp = g.tl.comp.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let layer = rc.layer;
+    let cy = rc.cy;
+    // Track matte: layer picker + kind.
+    let mr = Rect::from_min_size(pos2(cw.trkmat + 2.0, cy - 9.0), vec2(104.0, 18.0));
+    let label = match layer.track_matte {
+        Some(m) => comp.layer(m.layer).map(|l| format!("{} {}", comp.index_of(l.id).unwrap_or(0), l.name)).unwrap_or("None".into()),
+        None => "No Track Matte".into(),
+    };
+    // The cell is too narrow for the mode as well: it is in the tooltip and ticked in the menu.
+    let tip = layer.track_matte.map(|m| format!("{label} · {}", crate::i18n::tr(m.kind.label())));
+    let tresp = widgets::dropdown_tip(ui, mr, &label, tip.as_deref(), &t, egui::Id::unique(("trkmat", layer.id.0)));
+    app.auto.add(&format!("timeline.layer.{}.trackMatte", layer.id.0), mr, "Track Matte");
+    let pop = egui::Id::unique(("trk-pop", layer.id.0));
+    if tresp.clicked() {
+        widgets::open_popup(ui, pop);
+    }
+    // The menu lists every layer: built only while it is open (per visible row
+    // it made a big comp's timeline quadratic).
+    let mut opts = vec!["No Track Matte".to_string(), "-".to_string()];
+    let mut candidates: Vec<&Layer> = vec![];
+    if widgets::popup_is_open(ui, pop) {
+        for (i, l) in comp.layers.iter().enumerate().filter(|(_, l)| l.id != layer.id && l.source.is_av()) {
+            opts.push(format!("{}. {}", i + 1, l.name));
+            candidates.push(l);
+        }
+        opts.push("-".into());
+        for k in MatteKind::ALL {
+            opts.push(k.label().into());
+        }
+    }
+    let current = layer.track_matte.and_then(|m| opts.iter().position(|o| o == m.kind.label()));
+    if let Some(i) = widgets::popup_menu(ui, pop, mr.left_bottom(), &opts, current) {
+        let ids: Vec<LayerId> = candidates.iter().map(|l| l.id).collect();
+        if let Some(a) = opts.get(i).and_then(|o| track_matte_pick(layer, &ids, i, o)) {
+            actions.push(a);
+        }
+    }
+    if layer.track_matte.is_some() {
+        let kr = Rect::from_center_size(pos2(mr.max.x - 26.0, cy), vec2(10.0, 10.0));
+        let _ = kr;
+    }
+}
+
+/// The parent pick whip and dropdown.
+fn layer_parent_cell(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let comp = g.tl.comp.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let layer = rc.layer;
+    let cy = rc.cy;
+    pick_whip(
+        app,
+        ui,
+        &lp,
+        Rect::from_center_size(pos2(cw.parent + 9.0, cy), vec2(15.0, 15.0)),
+        (WHIP_PARENT, layer.id.0, 0),
+        WhipText {
+            auto: &format!("timeline.layer.{}.pickWhip", layer.id.0),
+            label: "Parent pick whip",
+            hint: crate::i18n::tr("Parent pick whip: drag onto a layer"),
+        },
+    );
+    let pr_rect = Rect::from_min_size(pos2(cw.parent + 20.0, cy - 9.0), vec2(94.0, 18.0));
+    let plabel = layer.parent.and_then(|p| comp.layer(p)).map(|l| format!("{}. {}", comp.index_of(l.id).unwrap_or(0), l.name)).unwrap_or_else(|| "None".into());
+    let presp = widgets::dropdown(ui, pr_rect, &plabel, &t, egui::Id::unique(("parent", layer.id.0)));
+    app.auto.add(&format!("timeline.layer.{}.parent", layer.id.0), pr_rect, "Parent");
+    let pop = egui::Id::unique(("par-pop", layer.id.0));
+    if presp.clicked() {
+        widgets::open_popup(ui, pop);
+    }
+    let mut cands: Vec<&Layer> = vec![];
+    let mut popts = vec!["None".to_string(), "-".to_string()];
+    if widgets::popup_is_open(ui, pop) {
+        for (i, l) in comp.layers.iter().enumerate().filter(|(_, l)| l.id != layer.id) {
+            popts.push(format!("{}. {}", i + 1, l.name));
+            cands.push(l);
+        }
+    }
+    if let Some(i) = widgets::popup_menu(ui, pop, pr_rect.left_bottom(), &popts, None) {
+        let par = if i == 0 { serde_json::Value::Null } else { json!(cands[i - 2].id.0) };
+        actions.push(("layer.setParent".into(), json!({"layers": [layer.id.0], "parent": par})));
+    }
+}
+
+/// Paints the layer bar; returns it and its label colour.
+fn layer_bar_paint(g: &Rw, rc: &RowCtx<'_>) -> (Rect, Color32) {
+    let t = g.tl.t;
+    let tm = g.tl.tm;
+    let gp = g.gp.clone();
+    let layer = rc.layer;
+    let r = rc.r;
+    let is_sel = rc.is_sel;
+    let x_in = tm.x(layer.in_point.seconds());
+    let x_out = tm.x(layer.out_point.seconds());
+    let bar = Rect::from_min_max(pos2(x_in, r.min.y + 1.0), pos2(x_out, r.max.y - 1.0));
+    let lc = t.label(layer.label);
+    let fill = bar_color(lc, is_sel);
+    gp.rect_filled(bar, 0.0, fill);
+    if is_sel {
+        gp.rect_stroke(bar, 0.0, Stroke::new(1.0, Color32::from_white_alpha(90)), StrokeKind::Inside);
+    }
+    (bar, lc)
+}
+
+/// Dragging the source bar outside the in/out span slips the source.
+fn slip_source_handles(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, ghost: Rect, bar: Rect) {
+    let pps = g.tl.pps;
+    let fd = g.tl.fd;
+    let ctx = g.tl.ctx.clone();
+    let actions = &mut g.tl.actions;
+    let ui_actions = &mut g.ui_actions;
+    let layer = rc.layer;
+    // Dragging the source bar outside the in/out span slips the source.
+    for (side, gr) in [("l", Rect::from_min_max(ghost.min, pos2(bar.min.x, ghost.max.y))), ("r", Rect::from_min_max(pos2(bar.max.x, ghost.min.y), ghost.max))] {
+        if gr.width() < 2.0 {
+            continue;
+        }
+        let gresp =
+            ui.interact(gr, egui::Id::unique(("ghost", side, layer.id.0)), Sense::click_and_drag()).on_hover_text(crate::i18n::tr("Drag to slip the source"));
+        // Outside the bar it is empty track area: a plain click deselects.
+        if gresp.clicked() && !ui.input(|i| i.modifiers.shift || i.modifiers.command) {
+            actions.push(("layer.select".into(), json!({"layers": []})));
+        }
+        app.auto.add(&format!("timeline.layer.{}.source{}", layer.id.0, side), gr, "Slip");
+        if gresp.hovered() || gresp.dragged() {
+            ctx.set_cursor_icon(egui::CursorIcon::ResizeHorizontal);
+        }
+        let acc_id = egui::Id::unique(("slip-acc", layer.id.0));
+        if gresp.dragged() {
+            let mut acc: f32 = ctx.data(|d| d.get_temp(acc_id).unwrap_or(0.0));
+            acc += gresp.drag_delta().x;
+            let frames = ((acc as f64 / pps) / fd).trunc() as i64;
+            if frames != 0 {
+                acc -= (frames as f64 * fd * pps) as f32;
+                actions.push(("layer.slip".into(), json!({"layers": [layer.id.0], "frames": frames, "merge": format!("slip-{}", layer.id.0)})));
             }
-            RowKind::Waveform { item } => {
-                lp.rect_filled(left, 0.0, if ri % 2 == 0 { t.row } else { t.row_alt });
-                let indent = cw.name + 6.0 + 14.0 * row.depth as f32;
-                lp.text(pos2(indent + 10.0, cy), Align2::LEFT_CENTER, "Waveform", Tokens::ui(12.0), t.text);
-                let wr = Rect::from_min_max(pos2(graph_x0, r.min.y), r.max);
-                gp.rect_filled(wr, 0.0, t.tl_bg);
-                app.auto.add(&format!("timeline.layer.{}.waveform", layer.id.0), wr, "Waveform");
-                match super::waveform::summary(app, &ctx, ItemId(*item)) {
-                    Some(s) => super::waveform::draw(&gp, wr.shrink2(vec2(0.0, 2.0)), &tm, layer, &s, Color32::from_rgb(0x5f, 0xc8, 0x8a)),
-                    None => {
-                        gp.text(
-                            pos2(tm.x(layer.in_point.seconds()).max(wr.min.x) + 6.0, wr.center().y),
-                            Align2::LEFT_CENTER,
-                            "Building waveform…",
-                            Tokens::ui(11.0),
-                            t.text_faint,
-                        );
-                    }
-                }
-            }
-            RowKind::Expr { uid, lines } => {
-                let Some(prop) = layer.props.find(*uid) else { continue };
-                let Some(ex) = prop.expr.clone() else { continue };
-                let (buf_id, edit_id) = (expr_buf_id(*uid), egui::Id::unique(("expr-edit", uid)));
-                // The same background as its property's row, selection included.
-                let sel_prop = app.session.state.selected_props.contains(&(layer.id, *uid));
-                lp.rect_filled(
-                    left,
-                    0.0,
-                    if sel_prop {
-                        t.row_selected
-                    } else if ri % 2 == 0 {
-                        t.row
-                    } else {
-                        t.row_alt
-                    },
-                );
-                let indent = cw.name + 6.0 + 14.0 * row.depth as f32;
-                lp.text(pos2(indent + 12.0, cy), Align2::LEFT_CENTER, crate::i18n::tr("Expression:"), Tokens::ui(11.5), t.text_dim);
-                lp.text(pos2(indent + 82.0, cy), Align2::LEFT_CENTER, &prop.name, Tokens::ui(11.5), t.text);
-                // "=" enable switch and the property pick whip (AE's expression controls).
-                let en_r = Rect::from_center_size(pos2(cw.switches + 10.0, cy), vec2(16.0, 16.0));
-                let en = ui.interact(en_r, egui::Id::unique(("expr-en", uid)), Sense::click()).on_hover_text(crate::i18n::tr("Enable Expression"));
-                lp.rect_stroke(en_r.shrink(1.0), 2.0, Stroke::new(1.0, t.separator), StrokeKind::Inside);
-                let expr_col = t.expr_text;
-                lp.text(
-                    en_r.center(),
-                    Align2::CENTER_CENTER,
-                    if ex.enabled { "=" } else { "≠" },
-                    Tokens::semibold(13.0),
-                    if ex.enabled { expr_col } else { t.text_dim },
-                );
-                app.auto.add(&format!("timeline.prop.{uid}.exprEnable"), en_r, "Enable Expression");
-                if en.clicked() {
-                    actions.push(("prop.setExpression".into(), json!({"layer": layer.id.0, "prop": uid, "enabled": !ex.enabled})));
-                }
-                let pw = pick_whip(
-                    app,
-                    ui,
-                    &lp,
-                    Rect::from_center_size(pos2(cw.switches + 30.0, cy), vec2(15.0, 15.0)),
-                    (WHIP_EXPR, layer.id.0, *uid),
-                    &format!("timeline.prop.{uid}.pickWhip"),
-                    "Expression pick whip",
-                    crate::i18n::tr("Expression pick whip: drag onto a property"),
-                );
-                if pw.is_pointer_button_down_on() && ui.input(|i| i.pointer.primary_pressed()) {
-                    // Pressed while the expression is being edited (its text is buffered while
-                    // the editor has the focus): the reference will go in at the cursor,
-                    // replacing the selection (#284).
-                    let into = ctx.data(|d| d.get_temp::<String>(buf_id)).map(|buf| {
-                        let n = buf.chars().count();
-                        let sel = egui::text_edit::TextEditState::load(&ctx, edit_id)
-                            .and_then(|st| st.cursor.char_range())
-                            .map_or([n, n], |r| [r.primary.index.0.min(r.secondary.index.0).min(n), r.primary.index.0.max(r.secondary.index.0).min(n)]);
-                        (buf, sel)
-                    });
-                    ctx.data_mut(|d| {
-                        if let Some(into) = into {
-                            d.insert_temp(whip_into_id(*uid), into);
-                        } else {
-                            d.remove::<WhipInto>(whip_into_id(*uid));
-                        }
-                    });
-                }
-                // Syntax errors: warning in the outline (the expression is disabled).
-                if let Some(check) = app.session.expr_check
-                    && let Err(e) = check(&ex.text)
-                {
-                    let wr = Rect::from_center_size(pos2(cw.switches + 50.0, cy), vec2(14.0, 14.0));
-                    lp.text(wr.center(), Align2::CENTER_CENTER, "⚠", Tokens::ui(12.0), Color32::from_rgb(0xf0, 0xa0, 0x30));
-                    let _ = ui.interact(wr, egui::Id::unique(("expr-err", uid)), Sense::hover()).on_hover_text(e);
-                }
-                // ⓕ: the Expression Language menu inserts at the cursor.
-                let lang_r = Rect::from_center_size(pos2(cw.switches + 70.0, cy), vec2(16.0, 16.0));
-                let lang = ui.interact(lang_r, egui::Id::unique(("expr-lang", uid)), Sense::click()).on_hover_text(crate::i18n::tr("Expression Language Menu"));
-                lp.circle_stroke(lang_r.center(), 6.5, Stroke::new(1.0, if lang.hovered() { t.text } else { t.text_dim }));
-                lp.text(lang_r.center(), Align2::CENTER_CENTER, "f", Tokens::semibold(10.0), if lang.hovered() { t.text } else { t.text_dim });
-                app.auto.add(&format!("timeline.prop.{uid}.exprLanguage"), lang_r, "Expression Language Menu");
-                let mut picked: Option<&'static str> = None;
-                egui::Popup::menu(&lang).style(crate::widgets::menu_style).show(|ui| {
-                    for (cat, items) in effectcraft_engine::commands::expr_tools::language_menu() {
-                        ui.menu_button(cat, |ui| {
-                            widgets::menu_scroll(ui, false, |ui| {
-                                for (label, text) in items {
-                                    if ui.button(label).clicked() {
-                                        picked = Some(text);
-                                        ui.close();
-                                    }
-                                }
-                            })
-                        });
-                    }
-                });
-                if let Some(text) = picked {
-                    let cur: String = ctx.data(|d| d.get_temp(buf_id)).unwrap_or_else(|| ex.text.clone());
-                    let at = egui::text_edit::TextEditState::load(&ctx, edit_id)
-                        .and_then(|st| st.cursor.char_range())
-                        .map(|r| r.primary.index.0)
-                        .unwrap_or(cur.chars().count())
-                        .min(cur.chars().count());
-                    let byte = cur.char_indices().nth(at).map(|(b, _)| b).unwrap_or(cur.len());
-                    let mut next = cur.clone();
-                    next.insert_str(byte, text);
-                    actions.push(("prop.setExpression".into(), json!({"layer": layer.id.0, "prop": uid, "expression": next})));
-                    ctx.data_mut(|d| d.remove::<String>(buf_id));
-                }
-                // The editor in the time-graph area.
-                ui.set_clip_rect(right_clip);
-                gp.rect_filled(Rect::from_min_max(pos2(graph_x0, r.min.y), r.max), 0.0, t.expr_bg);
-                let er = Rect::from_min_max(pos2(graph_x0 + 8.0, r.min.y + 3.0), pos2(rect.max.x - 14.0, r.max.y - 3.0));
-                let mut buf: String = ctx.data(|d| d.get_temp(buf_id)).unwrap_or_else(|| ex.text.clone());
-                if let Some(f) = ctx.data(|d| d.get_temp::<ExprFocus>(expr_focus_id())).filter(|f| f.prop == *uid) {
-                    // Asked for once (a pick whip put a reference in, or an Alt-click added the
-                    // expression): editing starts in the expression as it is now.
-                    ctx.data_mut(|d| d.remove::<ExprFocus>(expr_focus_id()));
-                    buf = ex.text.clone();
-                    let n = buf.chars().count();
-                    let [a, b] = f.select.map(|before_end| egui::text::CCursor::new(n.saturating_sub(before_end)));
-                    let mut st = egui::text_edit::TextEditState::load(&ctx, edit_id).unwrap_or_default();
-                    st.cursor.set_char_range(Some(egui::text::CCursorRange::two(a, b)));
-                    st.store(&ctx, edit_id);
-                    ctx.memory_mut(|m| m.request_focus(edit_id));
-                }
-                // Settings ▸ Scripting & Expressions ▸ Expressions Editor.
-                let sp = app.session.prefs.scripting.clone();
-                let resp = super::expr_editor::editor(ui, edit_id, &mut buf, er, &sp, if ex.enabled { expr_col } else { t.text_dim }, *lines, &t);
-                app.auto.add(&format!("timeline.prop.{uid}.expression"), er, &prop.name);
-                // Its bottom edge drags to set its height in whole lines, as in After Effects.
-                let edge = Rect::from_min_max(pos2(er.min.x, r.max.y - 4.0), pos2(er.max.x, r.max.y));
-                let eresp = ui.interact(edge, egui::Id::unique(("expr-edge", uid)), Sense::drag());
-                app.auto.add(&format!("timeline.prop.{uid}.expressionHeight"), edge, "Expression field height");
-                if eresp.hovered() || eresp.dragged() {
-                    ctx.set_cursor_icon(egui::CursorIcon::ResizeVertical);
-                }
-                if let Some(py) = eresp.interact_pointer_pos().filter(|_| eresp.dragged()).map(|p| p.y) {
-                    let n = ((py - r.min.y) / rh).round().clamp(1.0, EXPR_MAX_LINES as f32);
-                    app.ui.timeline.expr_lines.insert(*uid, n as usize);
-                }
-                let commit = resp.has_focus() && ui.input(|i| i.key_pressed(egui::Key::Enter) && (i.modifiers.command || i.modifiers.ctrl));
-                if commit {
-                    resp.surrender_focus();
-                }
-                if resp.has_focus() && !commit {
-                    ctx.data_mut(|d| d.insert_temp(buf_id, buf));
-                } else {
-                    if (resp.lost_focus() || commit) && buf.trim_end() != ex.text {
-                        actions.push(("prop.setExpression".into(), json!({"layer": layer.id.0, "prop": uid, "expression": buf.trim_end()})));
-                    }
-                    ctx.data_mut(|d| d.remove::<String>(buf_id));
-                }
-            }
-            RowKind::Prop { uid } => {
-                let Some(prop) = layer.props.find(*uid) else { continue };
-                app.auto.add(&format!("timeline.prop.{uid}.row"), r, &prop.name);
-                let sel_prop = app.session.state.selected_props.contains(&(layer.id, *uid));
-                lp.rect_filled(
-                    left,
-                    0.0,
-                    if sel_prop {
-                        t.row_selected
-                    } else if ri % 2 == 0 {
-                        t.row
-                    } else {
-                        t.row_alt
-                    },
-                );
-                gp.rect_filled(Rect::from_min_max(pos2(graph_x0, r.min.y), r.max), 0.0, t.tl_bg);
-                let indent = cw.name + 6.0 + 14.0 * row.depth as f32;
-                // Keyframe navigator (in the A/V column, like AE).
-                // (in the Keys column when it is shown).
-                if prop.is_animated() && (vis.keys || vis.av) {
-                    let lt = layer.layer_time(time);
-                    let at_key = effectcraft_engine::keyframe::key_at(&prop.keys, lt).is_some();
-                    let nav_x = if vis.keys { cw.keys + 12.0 } else { cw.av + 18.0 };
-                    let prev = Rect::from_center_size(pos2(nav_x, cy), vec2(12.0, 14.0));
-                    let mid = Rect::from_center_size(pos2(nav_x + 16.0, cy), vec2(14.0, 14.0));
-                    let next = Rect::from_center_size(pos2(nav_x + 32.0, cy), vec2(12.0, 14.0));
-                    icons::paint(&lp, prev.shrink(2.0), Icon::ChevronLeft, t.text_dim);
-                    icons::paint(&lp, next.shrink(2.0), Icon::ChevronRight, t.text_dim);
-                    let kc = if at_key { t.keyframe_selected } else { Color32::TRANSPARENT };
-                    lp.add(egui::Shape::convex_polygon(
-                        vec![mid.center() + vec2(0.0, -5.0), mid.center() + vec2(5.0, 0.0), mid.center() + vec2(0.0, 5.0), mid.center() + vec2(-5.0, 0.0)],
-                        kc,
-                        Stroke::new(1.0, t.text_dim),
-                    ));
-                    if ui.interact(prev, egui::Id::unique(("kprev", uid)), Sense::click()).clicked()
-                        && let Some(k) = prop.keys.iter().rev().find(|k| layer.comp_time(k.time).0 < time.0 - fr.frame_duration().0 / 2)
-                    {
-                        ui_actions.push(UiAct::SetTime(layer.comp_time(k.time)));
-                    }
-                    if ui.interact(next, egui::Id::unique(("knext", uid)), Sense::click()).clicked()
-                        && let Some(k) = prop.keys.iter().find(|k| layer.comp_time(k.time).0 > time.0 + fr.frame_duration().0 / 2)
-                    {
-                        ui_actions.push(UiAct::SetTime(layer.comp_time(k.time)));
-                    }
-                    if ui.interact(mid, egui::Id::unique(("kmid", uid)), Sense::click()).clicked() {
-                        actions.push(("prop.toggleKey".into(), json!({"layer": layer.id.0, "prop": uid})));
-                    }
-                    app.auto.add(&format!("timeline.prop.{uid}.addKey"), mid, "Add or remove keyframe");
-                }
-                // Stopwatch: Alt+click adds an expression; a press toggles the animation, and
-                // dragging on over other stopwatches gives them the same state (#284).
-                if !prop.static_only {
-                    let swr = Rect::from_center_size(pos2(indent, cy), vec2(15.0, 15.0));
-                    let resp = ui.interact(swr, egui::Id::unique(("stopwatch", uid)), Sense::click_and_drag());
-                    let col = if prop.is_animated() {
-                        t.hot_text
-                    } else if resp.hovered() {
-                        t.text
-                    } else {
-                        t.text_dim
-                    };
-                    icons::paint(&lp, swr, Icon::Stopwatch, col);
-                    app.auto.add(&format!("timeline.prop.{uid}.stopwatch"), swr, &prop.name);
-                    if ui.input(|i| i.modifiers.alt) {
-                        if resp.clicked() {
-                            actions.push(("prop.setExpression".into(), json!({"layer": layer.id.0, "prop": uid})));
-                            if prop.expr.is_none() {
-                                // Adding one: its editor opens, comes into view and takes the
-                                // keyboard with the new expression selected (#1072).
-                                app.ui.timeline.expr_closed.remove(uid);
-                                focus_expression(&ctx, *uid, [usize::MAX, 0]);
-                            } else if ctx.data(|d| d.get_temp::<ExprFocus>(expr_focus_id())).is_some_and(|f| f.prop == *uid) {
-                                // Removing it: nothing is left to take the keyboard.
-                                ctx.data_mut(|d| d.remove::<ExprFocus>(expr_focus_id()));
-                            }
-                        }
-                    } else if let Some((value, merge)) = switch_gesture(ui, &resp, r, "stopwatch", prop.is_animated()) {
-                        actions.push(("prop.toggleAnimation".into(), json!({"layer": layer.id.0, "prop": uid, "value": value, "merge": merge})));
-                    } else if resp.clicked() && !resp.clicked_by(egui::PointerButton::Primary) {
-                        // Keyboard or accessibility activation.
-                        actions.push(("prop.toggleAnimation".into(), json!({"layer": layer.id.0, "prop": uid})));
-                    }
-                }
-                let name_x = indent + 12.0;
-                // 3D layers show Rotation as "Z Rotation" next to X/Y Rotation.
-                let is_tr_rot = layer.transform().and_then(|t| t.get("rotation")).is_some_and(|r| r.uid == prop.uid);
-                let base = if is_tr_rot && prop.name == "Rotation" && layer.is_3d() { "Z Rotation".to_string() } else { prop.name.clone() };
-                let pname = if prop.has_expression() { format!("{base}  =") } else { base };
-                lp.text(pos2(name_x, cy), Align2::LEFT_CENTER, &pname, Tokens::ui(12.0), if prop.has_expression() { t.expr_text } else { t.text });
-                let name_rect = Rect::from_min_max(pos2(name_x, r.min.y), pos2(cw.switches - 2.0, r.max.y));
-                let name_resp = ui.interact(name_rect, egui::Id::unique(("pname", uid)), Sense::click_and_drag());
-                app.auto.add(&format!("timeline.prop.{uid}.name"), name_rect, &prop.name);
-                if name_resp.drag_started() {
-                    // Drop on the Essential Graphics panel to expose the property.
-                    egui::DragAndDrop::set_payload(&ctx, crate::panels::DragPayload::Property { layer: layer.id.0, prop: *uid });
-                }
-                if name_resp.dragged() {
-                    egui::Tooltip::always_open(ctx.clone(), ui.layer_id(), egui::Id::unique("prop-drag-tip"), egui::PopupAnchor::Pointer)
-                        .show(|ui| ui.label(&prop.name));
-                }
-                if name_resp.clicked() {
-                    actions.push(("prop.select".into(), json!({"layer": layer.id.0, "prop": uid, "add": ui.input(|i| i.modifiers.shift)})));
-                }
-                crate::widgets::context_menu(&name_resp, |ui| prop_menu(ui, &mut app.auto, cid, layer, prop, &mut actions));
-                // Value editors.
-                let value = ectx.value(layer, prop);
-                let vx = (cw.switches + 4.0).max(name_x + 120.0);
-                let dims = value_editor(app, ui, &lp, layer, prop, &value, pos2(vx, cy), &mut actions);
-                if !dims.is_empty() {
-                    dim_hits.push((*uid, dims));
-                }
-                // The property pick whip (Parent & Link column, AE CC 2018 and later): dropped on
-                // a property it links this one to it, adding the expression if there is none.
-                if vis.parent && !prop.static_only {
-                    pick_whip(
-                        app,
-                        ui,
-                        &lp,
-                        Rect::from_center_size(pos2(cw.parent + 9.0, cy), vec2(15.0, 15.0)),
-                        (WHIP_PROP, layer.id.0, *uid),
-                        &format!("timeline.prop.{uid}.propertyPickWhip"),
-                        "Property pick whip",
-                        crate::i18n::tr("Property pick whip: drag onto a property"),
-                    );
-                }
-                ui.set_clip_rect(right_clip);
-                // Expression text row hint.
-                if let Some(e) = prop.expr.as_ref().filter(|e| e.enabled && app.ui.timeline.expr_closed.contains(uid)) {
-                    gp.text(
-                        pos2(graph_x0 + 8.0, cy),
-                        Align2::LEFT_CENTER,
-                        format!("= {}", e.text.lines().next().unwrap_or("")),
-                        Tokens::mono(11.0),
-                        t.expr_text,
-                    );
-                }
-                // Keyframes.
-                if !graph_on {
-                    for k in &prop.keys {
-                        let ct = layer.comp_time(k.time);
-                        let x = tm.x(ct.seconds());
-                        if x < graph_x0 - 8.0 || x > rect.max.x + 8.0 {
-                            continue;
-                        }
-                        let kref = effectcraft_engine::KeyRef { layer: layer.id, prop: *uid, time: k.time };
-                        let ks = sel_keys.contains(&kref);
-                        let icon = k.icon();
-                        let c = pos2(x, cy);
-                        // Labelled keys take their label colour (brighter when selected).
-                        let kcol = match effectcraft_engine::color::Label::ALL.get(k.label as usize).filter(|_| k.label > 0) {
-                            Some(l) => {
-                                let c = t.label(*l);
-                                if ks { c } else { c.gamma_multiply(0.75) }
-                            }
-                            None if ks => t.keyframe_selected,
-                            None => t.keyframe,
-                        };
-                        if k.roving {
-                            // Roving keys: a small dot (their time follows their neighbours).
-                            gp.circle_filled(c, 2.5, kcol);
-                        } else {
-                            icons::keyframe(&gp, c, 11.0, icon.left, icon.right, kcol);
-                        }
-                        let kr = Rect::from_center_size(c, vec2(12.0, 14.0));
-                        let kresp = ui.interact(kr, egui::Id::unique(("key", uid, k.time.0)), Sense::click_and_drag());
-                        app.auto.add(&format!("timeline.key.{uid}.{}", fr.frame_at(ct)), kr, &format!("{} key", prop.name));
-                        // Exact (layer-time ticks): keys a Quick Offset puts on subframes can share a frame.
-                        app.auto.add(&format!("timeline.keyAt.{uid}.{}", k.time.0), kr, &format!("{} key", prop.name));
-                        let mods = ui.input(|i| i.modifiers);
-                        let this_key = json!({"keys": [{"layer": layer.id.0, "prop": uid, "time": k.time.seconds()}], "selectProperties": true});
-                        if kresp.clicked() && mods.command {
-                            // Ctrl+click: Linear ↔ Auto Bezier; Ctrl+Alt+click: Hold on / off.
-                            actions.push(("keys.select".into(), this_key.clone()));
-                            if mods.alt {
-                                actions.push(("keys.toggleHold".into(), json!({})));
-                            } else {
-                                let linear = k.in_interp == Interp::Linear && k.out_interp == Interp::Linear;
-                                actions.push(("keys.interpolation".into(), json!({"interpolation": if linear { "autoBezier" } else { "linear" }})));
-                            }
-                        } else if kresp.clicked() && mods.shift {
-                            // Shift+click: in or out of the selection.
-                            let mut p = this_key.clone();
-                            p["toggle"] = json!(true);
-                            actions.push(("keys.select".into(), p));
-                        } else if (kresp.clicked() || kresp.drag_started()) && !ks {
-                            let mut p = this_key.clone();
-                            p["add"] = json!(mods.shift);
-                            actions.push(("keys.select".into(), p));
-                        }
-                        if kresp.double_clicked() {
-                            // Edit the key's value (numeric properties), as After Effects does.
-                            if matches!(k.value, Value::Scalar(_) | Value::Vec2(_) | Value::Vec3(_)) {
-                                actions.push(("keys.set".into(), json!({"layer": layer.id.0, "prop": uid, "time": k.time.seconds()})));
-                            } else {
-                                ui_actions.push(UiAct::SetTime(ct));
-                            }
-                        }
-                        crate::widgets::context_menu(&kresp, |ui| {
-                            for (lbl, cmd, params) in [
-                                ("Edit Value…", "keys.set", json!({"layer": layer.id.0, "prop": uid, "time": k.time.seconds()})),
-                                ("-", "", json!({})),
-                                ("Copy", "keys.copy", json!({})),
-                                ("Paste", "keys.paste", json!({})),
-                                ("-", "", json!({})),
-                                ("Select Equal Keyframes", "keys.selectEqual", json!({})),
-                                ("Select Previous Keyframes", "keys.selectPrevious", json!({})),
-                                ("Select Following Keyframes", "keys.selectFollowing", json!({})),
-                                ("-", "", json!({})),
-                                ("Keyframe Interpolation…", "keys.interpolation", json!({})),
-                                ("Keyframe Velocity…", "keys.velocity", json!({})),
-                                ("Toggle Hold Keyframe", "keys.toggleHold", json!({})),
-                                ("Rove Across Time", "keys.interpolation", json!({"roving": !k.roving})),
-                                ("-", "", json!({})),
-                                ("Easy Ease", "keys.easyEase", json!({})),
-                                ("Easy Ease In", "keys.easyEaseIn", json!({})),
-                                ("Easy Ease Out", "keys.easyEaseOut", json!({})),
-                                ("Time-Reverse Keyframes", "keys.timeReverse", json!({})),
-                                ("-", "", json!({})),
-                                ("Linear", "keys.interpolation", json!({"interpolation": "linear"})),
-                                ("Bezier", "keys.interpolation", json!({"interpolation": "bezier"})),
-                                ("Auto Bezier", "keys.interpolation", json!({"interpolation": "autoBezier"})),
-                                ("Select All Keyframes", "keys.selectAll", json!({})),
-                                ("Delete", "keys.delete", json!({})),
-                            ] {
-                                if lbl == "Select All Keyframes" {
-                                    // Keyframe colour labels.
-                                    ui.menu_button(crate::i18n::tr("Label"), |ui| {
-                                        for (i, l) in effectcraft_engine::color::Label::ALL.into_iter().enumerate() {
-                                            if widgets::label_entry(ui, l, &app.session.prefs.label_name(l), k.label as usize == i, &t).clicked() {
-                                                if !ks {
-                                                    actions.push((
-                                                        "keys.select".into(),
-                                                        json!({"keys": [{"layer": layer.id.0, "prop": uid, "time": k.time.seconds()}]}),
-                                                    ));
-                                                }
-                                                actions.push(("keys.setLabel".into(), json!({"label": i})));
-                                                ui.close();
-                                            }
-                                        }
-                                    });
-                                }
-                                if lbl == "-" {
-                                    ui.separator();
-                                    continue;
-                                }
-                                if lbl == "Rove Across Time" && !prop.spatial {
-                                    continue;
-                                }
-                                if lbl == "Edit Value…" && !matches!(k.value, Value::Scalar(_) | Value::Vec2(_) | Value::Vec3(_)) {
-                                    continue;
-                                }
-                                if ui.button(lbl).clicked() {
-                                    if !ks {
-                                        actions.push(("keys.select".into(), json!({"keys": [{"layer": layer.id.0, "prop": uid, "time": k.time.seconds()}]})));
-                                    }
-                                    actions.push((cmd.into(), params));
-                                    ui.close();
-                                }
-                            }
-                        });
-                        // Alt-drag the first or last key of a selected group: scale the group in time.
-                        if kresp.drag_started()
-                            && mods.alt
-                            && !mods.command
-                            && let Some(c) = app.session.active_comp_arc()
-                        {
-                            super::graph_tools::alt_scale_begin(app, &ctx, &c, ct.seconds());
-                        }
-                        // A plain drag moves the selected keys. The timeline follows it (below): this
-                        // widget's id changes with the key's time, so its own drag would end after
-                        // the first frame of movement.
-                        // (From where the button went down: a drag starts a few pixels later.)
-                        if kresp.drag_started()
-                            && !super::graph_tools::alt_scale_active(&ctx)
-                            && let Some(p) = ctx.input(|i| i.pointer.press_origin())
-                        {
-                            // Ctrl/Cmd+Alt: Quick Offset of the selected keys' layers (#1012).
-                            let quick = (mods.command && mods.alt && ks).then(|| quick_offset_layers(&comp, sel_keys.iter().map(|k| k.layer))).flatten();
-                            ctx.data_mut(|d| d.insert_temp(key_drag_id(), KeyDrag { origin_x: p.x, anchor: ct.seconds(), applied: 0, quick }));
-                        }
-                    }
+            ctx.data_mut(|d| d.insert_temp(acc_id, acc));
+        }
+        if gresp.drag_stopped() {
+            ctx.data_mut(|d| d.remove::<f32>(acc_id));
+            ui_actions.push(UiAct::EndMerge);
+        }
+    }
+}
+
+/// The source extent behind the bar (striped past its ends).
+fn layer_source_extent(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, bar: Rect, lc: Color32) {
+    let tm = g.tl.tm;
+    let gp = g.gp.clone();
+    let layer = rc.layer;
+    let r = rc.r;
+    if let LayerSource::Footage { .. } | LayerSource::Comp { .. } = layer.source
+        && let Some(d) = layer.source.item().and_then(|i| app.session.project.item(i)).and_then(|i| i.duration())
+    {
+        let xs = tm.x(layer.start_time.seconds());
+        let xe = tm.x(layer.comp_time(d).seconds());
+        let ghost = Rect::from_min_max(pos2(xs.min(xe), r.min.y + 9.0), pos2(xs.max(xe), r.max.y - 9.0));
+        gp.rect_filled(ghost, 1.0, lc.gamma_multiply(0.18));
+        // The bar past the source's end (its last frame held) or before its start
+        // is striped, so the source's own span shows (#290). Time remapping
+        // decides what shows there itself.
+        if layer.props.get("timeRemap").is_none() {
+            for (side, part) in [
+                ("beforeSource", Rect::from_min_max(bar.min, pos2(ghost.min.x, bar.max.y))),
+                ("afterSource", Rect::from_min_max(pos2(ghost.max.x, bar.min.y), bar.max)),
+            ] {
+                if part.width() >= 1.0 {
+                    stripes(&gp, part, lc);
+                    app.auto.add(&format!("timeline.layer.{}.bar.{side}", layer.id.0), part, "Past the source");
                 }
             }
         }
+        slip_source_handles(app, ui, g, rc, ghost, bar);
     }
+}
+
+/// The bar's move body and trim edges, click selection.
+fn layer_bar_hits(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, bar: Rect) -> BarResps {
+    let cid = g.tl.cid;
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
+    let rows = &g.tl.rows;
+    let actions = &mut g.tl.actions;
+    let selected = &g.selected;
+    let layer = rc.layer;
+    let is_sel = rc.is_sel;
+    app.auto.add(&format!("timeline.layer.{}.bar", layer.id.0), bar, &layer.name);
+    // Interactions: move body, trim edges.
+    let (body_r, in_r, out_r) = trim_zones(bar);
+    let body = ui.interact(body_r, egui::Id::unique(("bar", layer.id.0)), Sense::click_and_drag());
+    let lin = ui.interact(in_r, egui::Id::unique(("bar-in", layer.id.0)), Sense::drag());
+    let lout = ui.interact(out_r, egui::Id::unique(("bar-out", layer.id.0)), Sense::drag());
+    app.auto.add(&format!("timeline.layer.{}.bar.in", layer.id.0), in_r, "Trim In");
+    app.auto.add(&format!("timeline.layer.{}.bar.out", layer.id.0), out_r, "Trim Out");
+    if lin.hovered() || lout.hovered() || lin.dragged() || lout.dragged() {
+        trim_cursor(&ctx);
+    }
+    if body.double_clicked()
+        && let Some(a) = double_click_action(layer)
+    {
+        actions.push(a);
+    }
+    let shift = ui.input(|i| i.modifiers.shift);
+    if let Some(layers) = (body.clicked() && shift).then(|| shift_range(&ctx, cid, &comp, rows, selected, layer.id)).flatten() {
+        // Shift-click: the layers from the last one clicked to this one, as in
+        // the layer outline.
+        actions.push(("layer.select".into(), json!({"layers": layers})));
+    } else {
+        if (body.clicked() || body.drag_started()) && !is_sel {
+            actions.push(("layer.select".into(), json!({"layers": [layer.id.0], "add": shift})));
+        }
+        if (body.clicked() || body.drag_started()) && !shift {
+            set_anchor(&ctx, cid, layer.id);
+        }
+    }
+    layer_context_menu(&body, &comp, layer, selected, LayerMenuCaps::of(&app.session.project, layer), &mut app.auto, &mut *actions);
+    BarResps { body, lin, lout }
+}
+
+fn layer_quick_offset_begin(ui: &mut egui::Ui, g: &Rw, rc: &RowCtx<'_>, body: &egui::Response) -> bool {
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
+    let selected = &g.selected;
+    let layer = rc.layer;
+    let is_sel = rc.is_sel;
+    let mods = ui.input(|i| i.modifiers);
+    if body.drag_started()
+        && is_sel
+        && mods.command
+        && mods.alt
+        && let Some(n) = quick_offset_layers(&comp, selected.iter().copied())
+        && let Some(p) = ctx.input(|i| i.pointer.press_origin())
+    {
+        ctx.data_mut(|d| d.insert_temp(quick_bar_id(), QuickBar { layer: layer.id, origin_x: p.x, layers: n, applied: 0 }));
+    }
+    ctx.data(|d| d.get_temp::<QuickBar>(quick_bar_id())).is_some_and(|q| q.layer == layer.id)
+}
+
+/// Moving and trimming a layer bar by whole frames.
+fn layer_bar_drag(g: &mut Rw, rc: &RowCtx<'_>, bars: &BarResps, quick: bool) {
+    let BarResps { body, lin, lout } = bars;
+    let pps = g.tl.pps;
+    let fd = g.tl.fd;
+    let ctx = g.tl.ctx.clone();
+    let actions = &mut g.tl.actions;
+    let selected = &g.selected;
+    let ui_actions = &mut g.ui_actions;
+    let layer = rc.layer;
+    let is_sel = rc.is_sel;
+    let drag_key = format!("bar-{}", layer.id.0);
+    for (resp, kind) in [(&body, "move"), (&lin, "in"), (&lout, "out")] {
+        if kind == "move" && quick {
+            continue;
+        }
+        if resp.dragged() {
+            let acc_id = egui::Id::unique(("bar-acc", layer.id.0, kind));
+            let mut acc: f32 = ctx.data(|d| d.get_temp(acc_id).unwrap_or(0.0));
+            acc += resp.drag_delta().x;
+            let frames = ((acc as f64 / pps) / fd).trunc() as i64;
+            if frames != 0 {
+                acc -= (frames as f64 * fd * pps) as f32;
+                let d = frames as f64 * fd;
+                // Moving or trimming a selected layer acts on the whole
+                // selection; each layer trims from its own in/out point.
+                let targets = if is_sel { json!(selected.iter().map(|l| l.0).collect::<Vec<_>>()) } else { json!([layer.id.0]) };
+                let params = match kind {
+                    "move" => json!({"layers": targets, "delta": d, "merge": drag_key}),
+                    "in" => json!({"layers": targets, "inDelta": d, "merge": drag_key}),
+                    _ => json!({"layers": targets, "outDelta": d, "merge": drag_key}),
+                };
+                actions.push(("layer.timing".into(), params));
+            }
+            ctx.data_mut(|d| d.insert_temp(acc_id, acc));
+        }
+        if resp.drag_stopped() {
+            ctx.data_mut(|d| d.remove::<f32>(egui::Id::unique(("bar-acc", layer.id.0, kind))));
+            ui_actions.push(UiAct::EndMerge);
+        }
+    }
+}
+
+fn layer_bar_markers(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Rw, rc: &RowCtx<'_>) {
+    let graph_x0 = g.tl.graph_x0;
+    let tm = g.tl.tm;
+    let rows_rect = g.tl.rows_rect;
+    let comp = g.tl.comp.clone();
+    let layer = rc.layer;
+    let r = rc.r;
+    let gclip = rows_rect.intersect(Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max));
+    super::markers_ui::layer_markers(app, ui, gclip, &comp, layer, tm, r);
+}
+
+/// The group row's background and effect label bar; returns the name to draw.
+fn group_background(app: &mut EffectcraftApp, g: &Rw, rc: &RowCtx<'_>) -> String {
+    let t = g.tl.t;
+    let graph_x0 = g.tl.graph_x0;
+    let lp = g.lp.clone();
+    let gp = g.gp.clone();
+    let layer = rc.layer;
+    let r = rc.r;
+    let left = rc.left;
+    let ri = rc.ri;
+    let RowKind::Group { uid, name, .. } = &rc.row.kind else { return String::new() };
+    let group = layer.props.find_group(*uid);
+    let shown = match group.and_then(|g| match &g.kind {
+        GroupKind::Effect { effect } => Some(effect.as_str()),
+        _ => None,
+    }) {
+        Some(effect) => crate::i18n::effects::group(effect, name),
+        None => name.clone(),
+    };
+    // Selected groups (an effect, a mask, a shape group…) highlight like selected
+    // property rows.
+    let sel_group = app.session.state.selected_props.contains(&(layer.id, *uid));
+    lp.rect_filled(
+        left,
+        0.0,
+        if sel_group {
+            t.row_selected
+        } else if ri.is_multiple_of(2) {
+            t.row
+        } else {
+            t.row_alt
+        },
+    );
+    gp.rect_filled(Rect::from_min_max(pos2(graph_x0, r.min.y), r.max), 0.0, t.tl_bg);
+    // An effect's colour label (26.5): the same bar the Effect Controls header wears,
+    // on the row's left edge.
+    if let Some(lab) =
+        group.filter(|g| matches!(g.kind, GroupKind::Effect { .. })).and_then(|g| g.label).filter(|l| *l != effectcraft_engine::color::Label::None)
+    {
+        let [lr, lg, lb] = app.session.prefs.label_rgb(lab);
+        let bar = Rect::from_min_size(left.min, vec2(4.0, left.height()));
+        lp.rect_filled(bar, 0.0, Color32::from_rgb(lr, lg, lb));
+        app.auto.add(&format!("timeline.group.{uid}.label"), bar, &app.session.prefs.label_name(lab));
+    }
+    shown
+}
+
+/// The group's twirl, effect switch and style eye.
+fn group_switches(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let ui_actions = &mut g.ui_actions;
+    let layer = rc.layer;
+    let cy = rc.cy;
+    let indent = rc.indent;
+    let RowKind::Group { uid, name, open, has_children, fx, eye, .. } = &rc.row.kind else { return };
+    if *has_children {
+        let tw = Rect::from_center_size(pos2(indent, cy), vec2(13.0, 13.0));
+        if widgets::twirl(ui, tw, *open, egui::Id::unique(("gtw", uid)), &t).clicked() {
+            // Alt/Cmd-click twirls the whole tree under the group (as on a layer).
+            ui_actions.push(UiAct::ToggleGroup(layer.id.0, *uid, ui.input(|i| i.modifiers.alt || i.modifiers.command)));
+        }
+        app.auto.add(&format!("timeline.group.{uid}.twirl"), tw, name);
+    }
+    if let Some(en) = fx {
+        let fr_ = Rect::from_center_size(pos2(cw.switches + SW * 3.0 + SW / 2.0, cy), vec2(16.0, 16.0));
+        if widgets::icon_toggle(ui, fr_, Icon::Fx, *en, &t, egui::Id::unique(("gfx", uid)), Sense::click()).clicked() {
+            actions.push(("effect.toggle".into(), json!({"layer": layer.id.0, "effect": uid})));
+        }
+        app.auto.add(&format!("timeline.group.{uid}.fx"), fr_, name);
+    }
+    if let Some(en) = eye {
+        // Layer style eye switch in the A/V column, like AE.
+        let er = Rect::from_center_size(pos2(cw.av + 10.0, cy), vec2(15.0, 15.0));
+        lp.rect_stroke(er.shrink(1.5), 2.0, Stroke::new(1.0, t.separator), StrokeKind::Inside);
+        if widgets::icon_toggle(ui, er, Icon::Eye, *en, &t, egui::Id::unique(("geye", uid)), Sense::click()).clicked() {
+            actions.push(("layer.style.toggle".into(), json!({"layer": layer.id.0, "style": uid})));
+        }
+        app.auto.add(&format!("timeline.group.{uid}.eye"), er, name);
+    }
+}
+
+/// The group name, or its rename field.
+fn group_name(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, shown: &str) {
+    let t = g.tl.t;
+    let ctx = g.tl.ctx.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let layer = rc.layer;
+    let r = rc.r;
+    let cy = rc.cy;
+    let indent = rc.indent;
+    let RowKind::Group { uid, name, .. } = &rc.row.kind else { return };
+    let group_edit: Option<(u64, u64, String)> = ctx.data(|d| d.get_temp(group_rename_id()));
+    if let Some((_, _, mut buf)) = group_edit.filter(|(rl, ru, _)| *rl == layer.id.0 && ru == uid) {
+        let field = Rect::from_min_max(pos2(indent + 8.0, r.min.y + 2.0), pos2((cw.switches - 4.0).max(indent + 60.0), r.max.y - 2.0));
+        let mut child = ui.new_child(egui::UiBuilder::new().max_rect(field));
+        let er = child.add(egui::TextEdit::singleline(&mut buf).font(Tokens::ui(12.0)).desired_width(field.width()));
+        app.auto.add(&format!("timeline.group.{uid}.nameEdit"), er.rect, &buf);
+        if ctx.data_mut(|d| d.remove_temp::<bool>(rename_focus_id())).unwrap_or(false) {
+            er.request_focus();
+            widgets::select_all(&ctx, er.id, &buf);
+        }
+        if er.lost_focus() {
+            if !ui.input(|i| i.key_pressed(egui::Key::Escape)) && !buf.trim().is_empty() && buf != *name {
+                actions.push(("prop.renameGroup".into(), json!({"layer": layer.id.0, "prop": uid, "name": buf})));
+            }
+            ctx.data_mut(|d| d.remove::<(u64, u64, String)>(group_rename_id()));
+        } else {
+            ctx.data_mut(|d| d.insert_temp(group_rename_id(), (layer.id.0, *uid, buf)));
+        }
+    } else {
+        lp.text(pos2(indent + 10.0, cy), Align2::LEFT_CENTER, shown, Tokens::ui(12.0), t.text);
+    }
+}
+
+/// Add / animate popups, Change Renderer and dash buttons.
+fn group_popups(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let ctx = g.tl.ctx.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let ui_actions = &mut g.ui_actions;
+    let layer = rc.layer;
+    let cy = rc.cy;
+    let RowKind::Group { uid, .. } = &rc.row.kind else { return };
+    text_anim_popups(app, ui, &lp, layer, *uid, pos2(cw.switches, cy), &mut *actions);
+    shape_add_popup(app, ui, &lp, layer, *uid, pos2(cw.switches, cy), &mut *actions);
+    if *uid == GEOM_BIT | layer.id.0 {
+        let lr = lp.text(pos2(cw.switches + 6.0, cy), Align2::LEFT_CENTER, crate::i18n::tr("Change Renderer…"), Tokens::ui(11.5), t.accent);
+        let resp = ui
+            .interact(lr, egui::Id::unique(("tl-change-renderer", layer.id.0)), Sense::click())
+            .on_hover_text(crate::i18n::tr("Composition Settings ▸ 3D Renderer"));
+        if resp.hovered() {
+            ctx.set_cursor_icon(egui::CursorIcon::PointingHand);
+        }
+        app.auto.add(&format!("timeline.layer.{}.changeRenderer", layer.id.0), lr, "Change Renderer…");
+        if resp.clicked() {
+            ui_actions.push(UiAct::ChangeRenderer);
+        }
+    }
+    dash_buttons(app, ui, &lp, layer, *uid, pos2(cw.switches, cy), &mut *actions);
+}
+
+/// Mask mode and inverted, inline.
+fn group_mask_mode(ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let layer = rc.layer;
+    let cy = rc.cy;
+    let RowKind::Group { uid, .. } = &rc.row.kind else { return };
+    // Mask mode + inverted inline.
+    if let Some(g) = layer.props.find_group(*uid)
+        && let GroupKind::Mask { mode, inverted, .. } = g.kind
+    {
+        let mr = Rect::from_min_size(pos2(cw.switches + 4.0, cy - 9.0), vec2(80.0, 18.0));
+        let pop = egui::Id::unique(("maskmode", uid));
+        if widgets::dropdown(ui, mr, mode.label(), &t, egui::Id::unique(("mm", uid))).clicked() {
+            widgets::open_popup(ui, pop);
+        }
+        let opts: Vec<String> = effectcraft_engine::project::MaskMode::ALL.iter().map(|m| m.label().to_string()).collect();
+        if let Some(i) = widgets::popup_menu(ui, pop, mr.left_bottom(), &opts, None) {
+            actions.push(("layer.setMask".into(), json!({"layer": layer.id.0, "mask": uid, "mode": opts[i]})));
+        }
+        let ir = Rect::from_min_size(pos2(mr.max.x + 8.0, cy - 8.0), vec2(16.0, 16.0));
+        if widgets::checkbox(ui, ir, inverted, &t, egui::Id::unique(("minv", uid))).clicked() {
+            actions.push(("layer.setMask".into(), json!({"layer": layer.id.0, "mask": uid, "inverted": !inverted})));
+        }
+        lp.text(pos2(ir.max.x + 4.0, cy), Align2::LEFT_CENTER, crate::i18n::tr("Inverted"), Tokens::ui(11.0), t.text_dim);
+    }
+}
+
+/// Group row click and double-click.
+fn group_row_click(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>) {
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let ui_actions = &mut g.ui_actions;
+    let layer = rc.layer;
+    let r = rc.r;
+    let indent = rc.indent;
+    let RowKind::Group { uid, name, fx, .. } = &rc.row.kind else { return };
+    let gr_rect = Rect::from_min_max(pos2(indent + 8.0, r.min.y), pos2(cw.switches, r.max.y));
+    let gr = ui.interact(gr_rect, egui::Id::unique(("grow", uid)), Sense::click());
+    app.auto.add(&format!("timeline.group.{uid}.name"), gr_rect, name);
+    if gr.clicked() && uid & (WAVE_BIT | GEOM_BIT) == 0 {
+        actions.push(("prop.select".into(), json!({"layer": layer.id.0, "prop": uid, "selectKeys": false})));
+    }
+    if gr.double_clicked() {
+        if fx.is_some() {
+            // An effect's name: open it in Effect Controls (as in After Effects).
+            actions.push(("layer.select".into(), json!({"layers": [layer.id.0]})));
+            actions.push(("prop.select".into(), json!({"layer": layer.id.0, "prop": uid, "selectKeys": false})));
+            actions.push(("window.panel".into(), json!({"panel": "EffectControls"})));
+        } else {
+            ui_actions.push(UiAct::ToggleGroup(layer.id.0, *uid, false));
+        }
+    }
+}
+
+fn waveform_row(app: &mut EffectcraftApp, g: &Rw, rc: &RowCtx<'_>) {
+    let t = g.tl.t;
+    let graph_x0 = g.tl.graph_x0;
+    let tm = g.tl.tm;
+    let ctx = g.tl.ctx.clone();
+    let cw = &g.tl.cw;
+    let lp = g.lp.clone();
+    let gp = g.gp.clone();
+    let row = rc.row;
+    let layer = rc.layer;
+    let r = rc.r;
+    let left = rc.left;
+    let cy = rc.cy;
+    let ri = rc.ri;
+    let RowKind::Waveform { item, .. } = &rc.row.kind else { return };
+    lp.rect_filled(left, 0.0, if ri.is_multiple_of(2) { t.row } else { t.row_alt });
+    let indent = cw.name + 6.0 + 14.0 * row.depth as f32;
+    lp.text(pos2(indent + 10.0, cy), Align2::LEFT_CENTER, "Waveform", Tokens::ui(12.0), t.text);
+    let wr = Rect::from_min_max(pos2(graph_x0, r.min.y), r.max);
+    gp.rect_filled(wr, 0.0, t.tl_bg);
+    app.auto.add(&format!("timeline.layer.{}.waveform", layer.id.0), wr, "Waveform");
+    match super::waveform::summary(app, &ctx, ItemId(*item)) {
+        Some(s) => super::waveform::draw(&gp, wr.shrink2(vec2(0.0, 2.0)), &tm, layer, &s, Color32::from_rgb(0x5f, 0xc8, 0x8a)),
+        None => {
+            gp.text(
+                pos2(tm.x(layer.in_point.seconds()).max(wr.min.x) + 6.0, wr.center().y),
+                Align2::LEFT_CENTER,
+                "Building waveform…",
+                Tokens::ui(11.0),
+                t.text_faint,
+            );
+        }
+    }
+}
+
+/// The expression row's outline side: enable, pick whip and syntax warning.
+fn expr_controls(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, st: &ExprRow<'_>) {
+    let ExprRow { prop, ex, buf_id, edit_id, .. } = *st;
+    let t = g.tl.t;
+    let ctx = g.tl.ctx.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let row = rc.row;
+    let layer = rc.layer;
+    let left = rc.left;
+    let cy = rc.cy;
+    let ri = rc.ri;
+    let RowKind::Expr { uid, .. } = &rc.row.kind else { return };
+    let sel_prop = app.session.state.selected_props.contains(&(layer.id, *uid));
+    lp.rect_filled(
+        left,
+        0.0,
+        if sel_prop {
+            t.row_selected
+        } else if ri.is_multiple_of(2) {
+            t.row
+        } else {
+            t.row_alt
+        },
+    );
+    let indent = cw.name + 6.0 + 14.0 * row.depth as f32;
+    lp.text(pos2(indent + 12.0, cy), Align2::LEFT_CENTER, crate::i18n::tr("Expression:"), Tokens::ui(11.5), t.text_dim);
+    lp.text(pos2(indent + 82.0, cy), Align2::LEFT_CENTER, &prop.name, Tokens::ui(11.5), t.text);
+    // "=" enable switch and the property pick whip (AE's expression controls).
+    let en_r = Rect::from_center_size(pos2(cw.switches + 10.0, cy), vec2(16.0, 16.0));
+    let en = ui.interact(en_r, egui::Id::unique(("expr-en", uid)), Sense::click()).on_hover_text(crate::i18n::tr("Enable Expression"));
+    lp.rect_stroke(en_r.shrink(1.0), 2.0, Stroke::new(1.0, t.separator), StrokeKind::Inside);
+    let expr_col = t.expr_text;
+    lp.text(en_r.center(), Align2::CENTER_CENTER, if ex.enabled { "=" } else { "≠" }, Tokens::semibold(13.0), if ex.enabled { expr_col } else { t.text_dim });
+    app.auto.add(&format!("timeline.prop.{uid}.exprEnable"), en_r, "Enable Expression");
+    if en.clicked() {
+        actions.push(("prop.setExpression".into(), json!({"layer": layer.id.0, "prop": uid, "enabled": !ex.enabled})));
+    }
+    let pw = pick_whip(
+        app,
+        ui,
+        &lp,
+        Rect::from_center_size(pos2(cw.switches + 30.0, cy), vec2(15.0, 15.0)),
+        (WHIP_EXPR, layer.id.0, *uid),
+        WhipText {
+            auto: &format!("timeline.prop.{uid}.pickWhip"),
+            label: "Expression pick whip",
+            hint: crate::i18n::tr("Expression pick whip: drag onto a property"),
+        },
+    );
+    if pw.is_pointer_button_down_on() && ui.input(|i| i.pointer.primary_pressed()) {
+        // Pressed while the expression is being edited (its text is buffered while
+        // the editor has the focus): the reference will go in at the cursor,
+        // replacing the selection (#284).
+        let into = ctx.data(|d| d.get_temp::<String>(buf_id)).map(|buf| {
+            let n = buf.chars().count();
+            let sel = egui::text_edit::TextEditState::load(&ctx, edit_id)
+                .and_then(|st| st.cursor.char_range())
+                .map_or([n, n], |r| [r.primary.index.0.min(r.secondary.index.0).min(n), r.primary.index.0.max(r.secondary.index.0).min(n)]);
+            (buf, sel)
+        });
+        ctx.data_mut(|d| {
+            if let Some(into) = into {
+                d.insert_temp(whip_into_id(*uid), into);
+            } else {
+                d.remove::<WhipInto>(whip_into_id(*uid));
+            }
+        });
+    }
+    // Syntax errors: warning in the outline (the expression is disabled).
+    if let Some(check) = app.session.expr_check
+        && let Err(e) = check(&ex.text)
+    {
+        let wr = Rect::from_center_size(pos2(cw.switches + 50.0, cy), vec2(14.0, 14.0));
+        lp.text(wr.center(), Align2::CENTER_CENTER, "⚠", Tokens::ui(12.0), Color32::from_rgb(0xf0, 0xa0, 0x30));
+        let _ = ui.interact(wr, egui::Id::unique(("expr-err", uid)), Sense::hover()).on_hover_text(e);
+    }
+}
+
+/// The Expression Language menu inserts at the cursor.
+fn expr_language_menu(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, st: &ExprRow<'_>) {
+    let ExprRow { ex, buf_id, edit_id, .. } = *st;
+    let t = g.tl.t;
+    let ctx = g.tl.ctx.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let layer = rc.layer;
+    let cy = rc.cy;
+    let RowKind::Expr { uid, .. } = &rc.row.kind else { return };
+    // ⓕ: the Expression Language menu inserts at the cursor.
+    let lang_r = Rect::from_center_size(pos2(cw.switches + 70.0, cy), vec2(16.0, 16.0));
+    let lang = ui.interact(lang_r, egui::Id::unique(("expr-lang", uid)), Sense::click()).on_hover_text(crate::i18n::tr("Expression Language Menu"));
+    lp.circle_stroke(lang_r.center(), 6.5, Stroke::new(1.0, if lang.hovered() { t.text } else { t.text_dim }));
+    lp.text(lang_r.center(), Align2::CENTER_CENTER, "f", Tokens::semibold(10.0), if lang.hovered() { t.text } else { t.text_dim });
+    app.auto.add(&format!("timeline.prop.{uid}.exprLanguage"), lang_r, "Expression Language Menu");
+    let mut picked: Option<&'static str> = None;
+    egui::Popup::menu(&lang).style(crate::widgets::menu_style).show(|ui| {
+        for (cat, items) in effectcraft_engine::commands::expr_tools::language_menu() {
+            ui.menu_button(cat, |ui| {
+                widgets::menu_scroll(ui, false, |ui| {
+                    for (label, text) in items {
+                        if ui.button(label).clicked() {
+                            picked = Some(text);
+                            ui.close();
+                        }
+                    }
+                })
+            });
+        }
+    });
+    if let Some(text) = picked {
+        let cur: String = ctx.data(|d| d.get_temp(buf_id)).unwrap_or_else(|| ex.text.clone());
+        let at = egui::text_edit::TextEditState::load(&ctx, edit_id)
+            .and_then(|st| st.cursor.char_range())
+            .map(|r| r.primary.index.0)
+            .unwrap_or(cur.chars().count())
+            .min(cur.chars().count());
+        let byte = cur.char_indices().nth(at).map(|(b, _)| b).unwrap_or(cur.len());
+        let mut next = cur.clone();
+        next.insert_str(byte, text);
+        actions.push(("prop.setExpression".into(), json!({"layer": layer.id.0, "prop": uid, "expression": next})));
+        ctx.data_mut(|d| d.remove::<String>(buf_id));
+    }
+}
+
+/// The expression editor in the time-graph area.
+fn expr_editor_cell(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, st: &ExprRow<'_>) {
+    let ExprRow { prop, ex, buf_id, edit_id, .. } = *st;
+    let t = g.tl.t;
+    let rect = g.tl.rect;
+    let graph_x0 = g.tl.graph_x0;
+    let rh = g.tl.rh;
+    let ctx = g.tl.ctx.clone();
+    let actions = &mut g.tl.actions;
+    let right_clip = g.right_clip;
+    let gp = g.gp.clone();
+    let layer = rc.layer;
+    let r = rc.r;
+    let RowKind::Expr { uid, lines, .. } = &rc.row.kind else { return };
+    let expr_col = t.expr_text;
+    // The editor in the time-graph area.
+    ui.set_clip_rect(right_clip);
+    gp.rect_filled(Rect::from_min_max(pos2(graph_x0, r.min.y), r.max), 0.0, t.expr_bg);
+    let er = Rect::from_min_max(pos2(graph_x0 + 8.0, r.min.y + 3.0), pos2(rect.max.x - 14.0, r.max.y - 3.0));
+    let mut buf: String = ctx.data(|d| d.get_temp(buf_id)).unwrap_or_else(|| ex.text.clone());
+    if let Some(f) = ctx.data(|d| d.get_temp::<ExprFocus>(expr_focus_id())).filter(|f| f.prop == *uid) {
+        // Asked for once (a pick whip put a reference in, or an Alt-click added the
+        // expression): editing starts in the expression as it is now.
+        ctx.data_mut(|d| d.remove::<ExprFocus>(expr_focus_id()));
+        buf = ex.text.clone();
+        let n = buf.chars().count();
+        let [a, b] = f.select.map(|before_end| egui::text::CCursor::new(n.saturating_sub(before_end)));
+        let mut st = egui::text_edit::TextEditState::load(&ctx, edit_id).unwrap_or_default();
+        st.cursor.set_char_range(Some(egui::text::CCursorRange::two(a, b)));
+        st.store(&ctx, edit_id);
+        ctx.memory_mut(|m| m.request_focus(edit_id));
+    }
+    // Settings ▸ Scripting & Expressions ▸ Expressions Editor.
+    let sp = app.session.prefs.scripting.clone();
+    let resp = super::expr_editor::editor(
+        ui,
+        edit_id,
+        &mut buf,
+        er,
+        super::expr_editor::EditorOpts { prefs: &sp, color: if ex.enabled { expr_col } else { t.text_dim }, rows: *lines },
+        &t,
+    );
+    app.auto.add(&format!("timeline.prop.{uid}.expression"), er, &prop.name);
+    // Its bottom edge drags to set its height in whole lines, as in After Effects.
+    let edge = Rect::from_min_max(pos2(er.min.x, r.max.y - 4.0), pos2(er.max.x, r.max.y));
+    let eresp = ui.interact(edge, egui::Id::unique(("expr-edge", uid)), Sense::drag());
+    app.auto.add(&format!("timeline.prop.{uid}.expressionHeight"), edge, "Expression field height");
+    if eresp.hovered() || eresp.dragged() {
+        ctx.set_cursor_icon(egui::CursorIcon::ResizeVertical);
+    }
+    if let Some(py) = eresp.interact_pointer_pos().filter(|_| eresp.dragged()).map(|p| p.y) {
+        let n = ((py - r.min.y) / rh).round().clamp(1.0, EXPR_MAX_LINES as f32);
+        app.ui.timeline.expr_lines.insert(*uid, n as usize);
+    }
+    let commit = resp.has_focus() && ui.input(|i| i.key_pressed(egui::Key::Enter) && (i.modifiers.command || i.modifiers.ctrl));
+    if commit {
+        resp.surrender_focus();
+    }
+    if resp.has_focus() && !commit {
+        ctx.data_mut(|d| d.insert_temp(buf_id, buf));
+    } else {
+        if (resp.lost_focus() || commit) && buf.trim_end() != ex.text {
+            actions.push(("prop.setExpression".into(), json!({"layer": layer.id.0, "prop": uid, "expression": buf.trim_end()})));
+        }
+        ctx.data_mut(|d| d.remove::<String>(buf_id));
+    }
+}
+
+fn prop_background(app: &mut EffectcraftApp, g: &Rw, rc: &RowCtx<'_>, prop: &Property) {
+    let t = g.tl.t;
+    let graph_x0 = g.tl.graph_x0;
+    let lp = g.lp.clone();
+    let gp = g.gp.clone();
+    let layer = rc.layer;
+    let r = rc.r;
+    let left = rc.left;
+    let ri = rc.ri;
+    let uid = &prop.uid;
+
+    app.auto.add(&format!("timeline.prop.{uid}.row"), r, &prop.name);
+    let sel_prop = app.session.state.selected_props.contains(&(layer.id, *uid));
+    lp.rect_filled(
+        left,
+        0.0,
+        if sel_prop {
+            t.row_selected
+        } else if ri.is_multiple_of(2) {
+            t.row
+        } else {
+            t.row_alt
+        },
+    );
+    gp.rect_filled(Rect::from_min_max(pos2(graph_x0, r.min.y), r.max), 0.0, t.tl_bg);
+}
+
+/// The keyframe navigator (previous, toggle, next).
+fn prop_key_navigator(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, prop: &Property) {
+    let t = g.tl.t;
+    let time = g.tl.time;
+    let fr = g.tl.fr;
+    let vis = g.tl.vis;
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let ui_actions = &mut g.ui_actions;
+    let layer = rc.layer;
+    let cy = rc.cy;
+    let uid = &prop.uid;
+
+    // Keyframe navigator (in the A/V column, like AE).
+    // (in the Keys column when it is shown).
+    if prop.is_animated() && (vis.keys || vis.av) {
+        let lt = layer.layer_time(time);
+        let at_key = effectcraft_engine::keyframe::key_at(&prop.keys, lt).is_some();
+        let nav_x = if vis.keys { cw.keys + 12.0 } else { cw.av + 18.0 };
+        let prev = Rect::from_center_size(pos2(nav_x, cy), vec2(12.0, 14.0));
+        let mid = Rect::from_center_size(pos2(nav_x + 16.0, cy), vec2(14.0, 14.0));
+        let next = Rect::from_center_size(pos2(nav_x + 32.0, cy), vec2(12.0, 14.0));
+        icons::paint(&lp, prev.shrink(2.0), Icon::ChevronLeft, t.text_dim);
+        icons::paint(&lp, next.shrink(2.0), Icon::ChevronRight, t.text_dim);
+        let kc = if at_key { t.keyframe_selected } else { Color32::TRANSPARENT };
+        lp.add(egui::Shape::convex_polygon(
+            vec![mid.center() + vec2(0.0, -5.0), mid.center() + vec2(5.0, 0.0), mid.center() + vec2(0.0, 5.0), mid.center() + vec2(-5.0, 0.0)],
+            kc,
+            Stroke::new(1.0, t.text_dim),
+        ));
+        if ui.interact(prev, egui::Id::unique(("kprev", uid)), Sense::click()).clicked()
+            && let Some(k) = prop.keys.iter().rev().find(|k| layer.comp_time(k.time).0 < time.0 - fr.frame_duration().0 / 2)
+        {
+            ui_actions.push(UiAct::SetTime(layer.comp_time(k.time)));
+        }
+        if ui.interact(next, egui::Id::unique(("knext", uid)), Sense::click()).clicked()
+            && let Some(k) = prop.keys.iter().find(|k| layer.comp_time(k.time).0 > time.0 + fr.frame_duration().0 / 2)
+        {
+            ui_actions.push(UiAct::SetTime(layer.comp_time(k.time)));
+        }
+        if ui.interact(mid, egui::Id::unique(("kmid", uid)), Sense::click()).clicked() {
+            actions.push(("prop.toggleKey".into(), json!({"layer": layer.id.0, "prop": uid})));
+        }
+        app.auto.add(&format!("timeline.prop.{uid}.addKey"), mid, "Add or remove keyframe");
+    }
+}
+
+/// The stopwatch.
+fn prop_stopwatch(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, prop: &Property) {
+    let t = g.tl.t;
+    let ctx = g.tl.ctx.clone();
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let layer = rc.layer;
+    let r = rc.r;
+    let cy = rc.cy;
+    let indent = rc.indent;
+    let uid = &prop.uid;
+
+    // Stopwatch: Alt+click adds an expression; a press toggles the animation, and
+    // dragging on over other stopwatches gives them the same state (#284).
+    if !prop.static_only {
+        let swr = Rect::from_center_size(pos2(indent, cy), vec2(15.0, 15.0));
+        let resp = ui.interact(swr, egui::Id::unique(("stopwatch", uid)), Sense::click_and_drag());
+        let col = if prop.is_animated() {
+            t.hot_text
+        } else if resp.hovered() {
+            t.text
+        } else {
+            t.text_dim
+        };
+        icons::paint(&lp, swr, Icon::Stopwatch, col);
+        app.auto.add(&format!("timeline.prop.{uid}.stopwatch"), swr, &prop.name);
+        if ui.input(|i| i.modifiers.alt) {
+            if resp.clicked() {
+                actions.push(("prop.setExpression".into(), json!({"layer": layer.id.0, "prop": uid})));
+                if prop.expr.is_none() {
+                    // Adding one: its editor opens, comes into view and takes the
+                    // keyboard with the new expression selected (#1072).
+                    app.ui.timeline.expr_closed.remove(uid);
+                    focus_expression(&ctx, *uid, [usize::MAX, 0]);
+                } else if ctx.data(|d| d.get_temp::<ExprFocus>(expr_focus_id())).is_some_and(|f| f.prop == *uid) {
+                    // Removing it: nothing is left to take the keyboard.
+                    ctx.data_mut(|d| d.remove::<ExprFocus>(expr_focus_id()));
+                }
+            }
+        } else if let Some((value, merge)) = switch_gesture(ui, &resp, r, "stopwatch", prop.is_animated()) {
+            actions.push(("prop.toggleAnimation".into(), json!({"layer": layer.id.0, "prop": uid, "value": value, "merge": merge})));
+        } else if resp.clicked() && !resp.clicked_by(egui::PointerButton::Primary) {
+            // Keyboard or accessibility activation.
+            actions.push(("prop.toggleAnimation".into(), json!({"layer": layer.id.0, "prop": uid})));
+        }
+    }
+}
+
+/// The property name; returns its x.
+fn prop_name(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, prop: &Property) -> f32 {
+    let t = g.tl.t;
+    let cid = g.tl.cid;
+    let ctx = g.tl.ctx.clone();
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let layer = rc.layer;
+    let r = rc.r;
+    let cy = rc.cy;
+    let indent = rc.indent;
+    let uid = &prop.uid;
+
+    let name_x = indent + 12.0;
+    // 3D layers show Rotation as "Z Rotation" next to X/Y Rotation.
+    let is_tr_rot = layer.transform().and_then(|t| t.get("rotation")).is_some_and(|r| r.uid == prop.uid);
+    let base = if is_tr_rot && prop.name == "Rotation" && layer.is_3d() { "Z Rotation".to_string() } else { prop.name.clone() };
+    let pname = if prop.has_expression() { format!("{base}  =") } else { base };
+    lp.text(pos2(name_x, cy), Align2::LEFT_CENTER, &pname, Tokens::ui(12.0), if prop.has_expression() { t.expr_text } else { t.text });
+    let name_rect = Rect::from_min_max(pos2(name_x, r.min.y), pos2(cw.switches - 2.0, r.max.y));
+    let name_resp = ui.interact(name_rect, egui::Id::unique(("pname", uid)), Sense::click_and_drag());
+    app.auto.add(&format!("timeline.prop.{uid}.name"), name_rect, &prop.name);
+    if name_resp.drag_started() {
+        // Drop on the Essential Graphics panel to expose the property.
+        egui::DragAndDrop::set_payload(&ctx, crate::panels::DragPayload::Property { layer: layer.id.0, prop: *uid });
+    }
+    if name_resp.dragged() {
+        egui::Tooltip::always_open(ctx.clone(), ui.layer_id(), egui::Id::unique("prop-drag-tip"), egui::PopupAnchor::Pointer).show(|ui| ui.label(&prop.name));
+    }
+    if name_resp.clicked() {
+        actions.push(("prop.select".into(), json!({"layer": layer.id.0, "prop": uid, "add": ui.input(|i| i.modifiers.shift)})));
+    }
+    crate::widgets::context_menu(&name_resp, |ui| prop_menu(ui, &mut app.auto, cid, layer, prop, &mut *actions));
+    name_x
+}
+
+/// The value editors and the property pick whip.
+fn prop_value_cell(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, rc: &RowCtx<'_>, ectx: &EvalCtx<'_>, prop: &Property, name_x: f32) {
+    let vis = g.tl.vis;
+    let cw = &g.tl.cw;
+    let actions = &mut g.tl.actions;
+    let lp = g.lp.clone();
+    let dim_hits = &mut g.dim_hits;
+    let layer = rc.layer;
+    let cy = rc.cy;
+    let uid = &prop.uid;
+
+    let value = ectx.value(layer, prop);
+    let vx = (cw.switches + 4.0).max(name_x + 120.0);
+    let ve = ValueEdit::new(ui, &lp, layer, prop, pos2(vx, cy));
+    let dims = value_editor(app, ui, &ve, &value, &mut *actions);
+    if !dims.is_empty() {
+        dim_hits.push((*uid, dims));
+    }
+    // The property pick whip (Parent & Link column, AE CC 2018 and later): dropped on
+    // a property it links this one to it, adding the expression if there is none.
+    if vis.parent && !prop.static_only {
+        pick_whip(
+            app,
+            ui,
+            &lp,
+            Rect::from_center_size(pos2(cw.parent + 9.0, cy), vec2(15.0, 15.0)),
+            (WHIP_PROP, layer.id.0, *uid),
+            WhipText {
+                auto: &format!("timeline.prop.{uid}.propertyPickWhip"),
+                label: "Property pick whip",
+                hint: crate::i18n::tr("Property pick whip: drag onto a property"),
+            },
+        );
+    }
+}
+
+/// The one-line expression hint when its editor is closed.
+fn prop_expression_hint(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Rw, rc: &RowCtx<'_>, prop: &Property) {
+    let t = g.tl.t;
+    let graph_x0 = g.tl.graph_x0;
+    let right_clip = g.right_clip;
+    let gp = g.gp.clone();
+    let cy = rc.cy;
+    let uid = &prop.uid;
+
+    ui.set_clip_rect(right_clip);
+    // Expression text row hint.
+    if let Some(e) = prop.expr.as_ref().filter(|e| e.enabled && app.ui.timeline.expr_closed.contains(uid)) {
+        gp.text(pos2(graph_x0 + 8.0, cy), Align2::LEFT_CENTER, format!("= {}", e.text.lines().next().unwrap_or("")), Tokens::mono(11.0), t.expr_text);
+    }
+}
+
+/// Key click selection and interpolation shortcuts.
+fn key_select(g: &mut Rw, kh: &KeyHit<'_>) {
+    let KeyHit { k, ks, mods, ref kresp, ref this_key, .. } = *kh;
+    let actions = &mut g.tl.actions;
+    if kresp.clicked() && mods.command {
+        // Ctrl+click: Linear ↔ Auto Bezier; Ctrl+Alt+click: Hold on / off.
+        actions.push(("keys.select".into(), this_key.clone()));
+        if mods.alt {
+            actions.push(("keys.toggleHold".into(), json!({})));
+        } else {
+            let linear = k.in_interp == Interp::Linear && k.out_interp == Interp::Linear;
+            actions.push(("keys.interpolation".into(), json!({"interpolation": if linear { "autoBezier" } else { "linear" }})));
+        }
+    } else if kresp.clicked() && mods.shift {
+        // Shift+click: in or out of the selection.
+        let mut p = this_key.clone();
+        p["toggle"] = json!(true);
+        actions.push(("keys.select".into(), p));
+    } else if (kresp.clicked() || kresp.drag_started()) && !ks {
+        let mut p = this_key.clone();
+        p["add"] = json!(mods.shift);
+        actions.push(("keys.select".into(), p));
+    }
+}
+
+fn key_double_click(g: &mut Rw, rc: &RowCtx<'_>, prop: &Property, kh: &KeyHit<'_>) {
+    let KeyHit { k, ct, ref kresp, .. } = *kh;
+    let actions = &mut g.tl.actions;
+    let ui_actions = &mut g.ui_actions;
+    let layer = rc.layer;
+    let uid = &prop.uid;
+
+    if kresp.double_clicked() {
+        // Edit the key's value (numeric properties), as After Effects does.
+        if matches!(k.value, Value::Scalar(_) | Value::Vec2(_) | Value::Vec3(_)) {
+            actions.push(("keys.set".into(), json!({"layer": layer.id.0, "prop": uid, "time": k.time.seconds()})));
+        } else {
+            ui_actions.push(UiAct::SetTime(ct));
+        }
+    }
+}
+
+/// The keyframe right-click menu.
+fn key_context_menu(app: &mut EffectcraftApp, g: &mut Rw, rc: &RowCtx<'_>, prop: &Property, kh: &KeyHit<'_>) {
+    let KeyHit { k, ks, ref kresp, .. } = *kh;
+    let t = g.tl.t;
+    let actions = &mut g.tl.actions;
+    let layer = rc.layer;
+    let uid = &prop.uid;
+
+    crate::widgets::context_menu(kresp, |ui| {
+        for (lbl, cmd, params) in [
+            ("Edit Value…", "keys.set", json!({"layer": layer.id.0, "prop": uid, "time": k.time.seconds()})),
+            ("-", "", json!({})),
+            ("Copy", "keys.copy", json!({})),
+            ("Paste", "keys.paste", json!({})),
+            ("-", "", json!({})),
+            ("Select Equal Keyframes", "keys.selectEqual", json!({})),
+            ("Select Previous Keyframes", "keys.selectPrevious", json!({})),
+            ("Select Following Keyframes", "keys.selectFollowing", json!({})),
+            ("-", "", json!({})),
+            ("Keyframe Interpolation…", "keys.interpolation", json!({})),
+            ("Keyframe Velocity…", "keys.velocity", json!({})),
+            ("Toggle Hold Keyframe", "keys.toggleHold", json!({})),
+            ("Rove Across Time", "keys.interpolation", json!({"roving": !k.roving})),
+            ("-", "", json!({})),
+            ("Easy Ease", "keys.easyEase", json!({})),
+            ("Easy Ease In", "keys.easyEaseIn", json!({})),
+            ("Easy Ease Out", "keys.easyEaseOut", json!({})),
+            ("Time-Reverse Keyframes", "keys.timeReverse", json!({})),
+            ("-", "", json!({})),
+            ("Linear", "keys.interpolation", json!({"interpolation": "linear"})),
+            ("Bezier", "keys.interpolation", json!({"interpolation": "bezier"})),
+            ("Auto Bezier", "keys.interpolation", json!({"interpolation": "autoBezier"})),
+            ("Select All Keyframes", "keys.selectAll", json!({})),
+            ("Delete", "keys.delete", json!({})),
+        ] {
+            if lbl == "Select All Keyframes" {
+                // Keyframe colour labels.
+                ui.menu_button(crate::i18n::tr("Label"), |ui| {
+                    for (i, l) in effectcraft_engine::color::Label::ALL.into_iter().enumerate() {
+                        if widgets::label_entry(ui, l, &app.session.prefs.label_name(l), k.label as usize == i, &t).clicked() {
+                            if !ks {
+                                actions.push(("keys.select".into(), json!({"keys": [{"layer": layer.id.0, "prop": uid, "time": k.time.seconds()}]})));
+                            }
+                            actions.push(("keys.setLabel".into(), json!({"label": i})));
+                            ui.close();
+                        }
+                    }
+                });
+            }
+            if lbl == "-" {
+                ui.separator();
+                continue;
+            }
+            if lbl == "Rove Across Time" && !prop.spatial {
+                continue;
+            }
+            if lbl == "Edit Value…" && !matches!(k.value, Value::Scalar(_) | Value::Vec2(_) | Value::Vec3(_)) {
+                continue;
+            }
+            if ui.button(lbl).clicked() {
+                if !ks {
+                    actions.push(("keys.select".into(), json!({"keys": [{"layer": layer.id.0, "prop": uid, "time": k.time.seconds()}]})));
+                }
+                actions.push((cmd.into(), params));
+                ui.close();
+            }
+        }
+    });
+}
+
+/// Starts a key drag (or Alt-scale).
+fn key_drag_begin(app: &mut EffectcraftApp, g: &Rw, kh: &KeyHit<'_>) {
+    let KeyHit { ct, ks, mods, ref kresp, .. } = *kh;
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
+    let sel_keys = &g.sel_keys;
+    // Alt-drag the first or last key of a selected group: scale the group in time.
+    if kresp.drag_started()
+        && mods.alt
+        && !mods.command
+        && let Some(c) = app.session.active_comp_arc()
+    {
+        super::graph_tools::alt_scale_begin(app, &ctx, &c, ct.seconds());
+    }
+    // A plain drag moves the selected keys. The timeline follows it (below): this
+    // widget's id changes with the key's time, so its own drag would end after
+    // the first frame of movement.
+    // (From where the button went down: a drag starts a few pixels later.)
+    if kresp.drag_started()
+        && !super::graph_tools::alt_scale_active(&ctx)
+        && let Some(p) = ctx.input(|i| i.pointer.press_origin())
+    {
+        // Ctrl/Cmd+Alt: Quick Offset of the selected keys' layers (#1012).
+        let quick = (mods.command && mods.alt && ks).then(|| quick_offset_layers(&comp, sel_keys.iter().map(|k| k.layer))).flatten();
+        ctx.data_mut(|d| d.insert_temp(key_drag_id(), KeyDrag { origin_x: p.x, anchor: ct.seconds(), applied: 0, quick }));
+    }
+}
+
+/// Paints one keyframe marker; returns its hit rect.
+fn key_paint(g: &Rw, rc: &RowCtx<'_>, k: &effectcraft_engine::keyframe::Keyframe, x: f32, ks: bool) -> Rect {
+    let t = g.tl.t;
+    let gp = g.gp.clone();
+    let cy = rc.cy;
+    let icon = k.icon();
+    let c = pos2(x, cy);
+    // Labelled keys take their label colour (brighter when selected).
+    let kcol = match effectcraft_engine::color::Label::ALL.get(k.label as usize).filter(|_| k.label > 0) {
+        Some(l) => {
+            let c = t.label(*l);
+            if ks { c } else { c.gamma_multiply(0.75) }
+        }
+        None if ks => t.keyframe_selected,
+        None => t.keyframe,
+    };
+    if k.roving {
+        // Roving keys: a small dot (their time follows their neighbours).
+        gp.circle_filled(c, 2.5, kcol);
+    } else {
+        icons::keyframe(&gp, c, 11.0, icon.left, icon.right, kcol);
+    }
+    Rect::from_center_size(c, vec2(12.0, 14.0))
+}
+
+/// The key's hit target and automation ids.
+fn key_hit(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    g: &Rw,
+    rc: &RowCtx<'_>,
+    prop: &Property,
+    k: &effectcraft_engine::keyframe::Keyframe,
+    kr: Rect,
+) -> egui::Response {
+    let fr = g.tl.fr;
+    let layer = rc.layer;
+    let uid = &prop.uid;
+    let ct = layer.comp_time(k.time);
+    let kresp = ui.interact(kr, egui::Id::unique(("key", uid, k.time.0)), Sense::click_and_drag());
+    app.auto.add(&format!("timeline.key.{uid}.{}", fr.frame_at(ct)), kr, &format!("{} key", prop.name));
+    // Exact (layer-time ticks): keys a Quick Offset puts on subframes can share a frame.
+    app.auto.add(&format!("timeline.keyAt.{uid}.{}", k.time.0), kr, &format!("{} key", prop.name));
+    kresp
+}
+
+/// Right-click menus on the empty outline and graph areas.
+fn background_menus(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw) {
+    let actions = &mut g.tl.actions;
+    let graph_on = g.graph_on;
+    let full_clip = g.full_clip;
+    let empty_rect = g.empty_rect;
+    let empty = g.empty.clone();
+    let outline_empty = g.outline_empty.clone();
     ui.set_clip_rect(full_clip);
     // The background responses sit below rows, bars and editors, preserving their menus.
     if !graph_on {
@@ -3231,6 +4195,18 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
         });
     }
+}
+
+/// Click and marquee-select on the empty outline.
+fn outline_marquee(ui: &mut egui::Ui, g: &mut Rw) {
+    let t = g.tl.t;
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
+    let actions = &mut g.tl.actions;
+    let outline_rect = g.outline_rect;
+    let lp = g.lp.clone();
+    let outline_empty = g.outline_empty.clone();
+    let hit_rows = &mut g.hit_rows;
     if outline_empty.clicked() && !ui.input(|i| i.modifiers.shift || i.modifiers.command) {
         actions.push(("layer.select".into(), json!({"layers": []})));
     }
@@ -3255,6 +4231,16 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         actions.push(("layer.select".into(), json!({"layers": layers, "add": ui.input(|i| i.modifiers.shift || i.modifiers.command)})));
     }
     // Pick whips: a line follows the pointer; releasing over a row links to it (an expression's
+}
+
+/// A pick whip in flight: its line, the target and the link on release.
+fn pick_whip_drag(g: &mut Rw) {
+    let t = g.tl.t;
+    let graph_x0 = g.tl.graph_x0;
+    let ctx = g.tl.ctx.clone();
+    let actions = &mut g.tl.actions;
+    let hit_rows = &mut g.hit_rows;
+    let dim_hits = &mut g.dim_hits;
     // or a property's, also over a property in Effect Controls).
     if let Some((kind, src_layer, src_prop, start)) = ctx.data(|d| d.get_temp::<PickWhip>(pick_whip_id())) {
         let ptr = ctx.input(|i| i.pointer.latest_pos()).unwrap_or(start);
@@ -3314,16 +4300,42 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
     }
     // Alt-drag key group scaling (follows the pointer until release).
+}
+
+fn alt_scale_and_graph(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw, ectx: &EvalCtx<'_>) {
+    let graph_x0 = g.tl.graph_x0;
+    let tm = g.tl.tm;
+    let rows_rect = g.tl.rows_rect;
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
+    let actions = &mut g.tl.actions;
+    let graph_on = g.graph_on;
+    let gp = g.gp.clone();
     if let Some(c) = app.session.active_comp_arc() {
-        super::graph_tools::alt_scale_update(app, &ctx, &c, tm, &mut actions);
+        super::graph_tools::alt_scale_update(app, &ctx, &c, tm, &mut *actions);
     }
     // Graph editor.
     if graph_on {
-        super::graph::show(app, ui, &gp, &comp, &ectx, tm, Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max), &mut actions);
+        super::graph::show(
+            app,
+            ui,
+            &gp,
+            super::graph::GraphView { comp: &comp, ectx, tm },
+            Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max),
+            &mut *actions,
+        );
     }
     // A plain click on empty track area (beside a layer's bar, on a property row's empty span or
     // below the last row) deselects the layers and their keys and properties, as in After
-    // Effects; Shift / Cmd keep the selection. Drag: box-select keys.
+}
+
+/// Click / marquee on empty track area.
+fn graph_empty_area(ui: &mut egui::Ui, g: &mut Rw) {
+    let t = g.tl.t;
+    let ctx = g.tl.ctx.clone();
+    let actions = &mut g.tl.actions;
+    let gp = g.gp.clone();
+    let empty = g.empty.clone();
     if empty.clicked() && !ui.input(|i| i.modifiers.shift || i.modifiers.command) {
         actions.push(("layer.select".into(), json!({"layers": []})));
     }
@@ -3335,7 +4347,19 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         gp.rect_stroke(br, 0.0, Stroke::new(1.0, t.accent), StrokeKind::Middle);
         ctx.data_mut(|d| d.insert_temp(egui::Id::unique("tl-box"), br));
     }
-    // Layer reorder drag: a line where the layers will land; the release moves them there.
+}
+
+/// Layer reorder drag: a line where the layers land.
+fn layer_reorder_drag(ui: &mut egui::Ui, g: &mut Rw) {
+    let t = g.tl.t;
+    let rect = g.tl.rect;
+    let graph_x0 = g.tl.graph_x0;
+    let rows_rect = g.tl.rows_rect;
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
+    let p = g.tl.p.clone();
+    let actions = &mut g.tl.actions;
+    let hit_rows = &mut g.hit_rows;
     if let Some(moving) = ctx.data(|d| d.get_temp::<Vec<u64>>(layer_drag_id())) {
         let dropped = ctx.data_mut(|d| d.remove_temp::<bool>(layer_drop_id())).unwrap_or(false);
         let layer_rows: Vec<(Rect, LayerId)> = hit_rows.iter().filter(|(_, r)| matches!(r.kind, RowKind::Layer)).map(|(rr, r)| (*rr, r.layer)).collect();
@@ -3366,7 +4390,16 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
     }
     // Quick Offset of layer bars: the last selected layer moves by whole frames with the pointer
-    // until the button is released, wherever the bar's row has scrolled to.
+}
+
+/// Quick Offset of layer bars follows the pointer.
+fn quick_offset_follow(g: &mut Rw) {
+    let t = g.tl.t;
+    let pps = g.tl.pps;
+    let fd = g.tl.fd;
+    let ctx = g.tl.ctx.clone();
+    let actions = &mut g.tl.actions;
+    let ui_actions = &mut g.ui_actions;
     if let Some(mut q) = ctx.data(|d| d.get_temp::<QuickBar>(quick_bar_id())) {
         let (down, ptr) = ctx.input(|i| (i.pointer.primary_down(), i.pointer.latest_pos()));
         match ptr.filter(|_| down) {
@@ -3388,7 +4421,19 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
     // Keyframe drag: the selected keys move by whole frames with the pointer until it is
     // released (one undo step); Shift snaps the grabbed key to the current time, the work area
-    // and composition markers.
+}
+
+/// The key drag moves the selected keys by whole frames.
+fn key_drag_follow(app: &mut EffectcraftApp, g: &mut Rw) {
+    let t = g.tl.t;
+    let time = g.tl.time;
+    let pps = g.tl.pps;
+    let fd = g.tl.fd;
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
+    let rows = &g.tl.rows;
+    let actions = &mut g.tl.actions;
+    let ui_actions = &mut g.ui_actions;
     if let Some(mut kd) = ctx.data(|d| d.get_temp::<KeyDrag>(key_drag_id())) {
         let (down, ptr, shift) = ctx.input(|i| (i.pointer.primary_down(), i.pointer.latest_pos(), i.modifiers.shift));
         match ptr.filter(|_| down) {
@@ -3399,7 +4444,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                     // not the moving keys themselves.
                     let moving: Vec<f64> =
                         app.session.state.selected_keys.iter().filter_map(|k| comp.layer(k.layer).map(|l| l.comp_time(k.time).seconds())).collect();
-                    let mut cands = snap_candidates(&comp, &rows);
+                    let mut cands = snap_candidates(&comp, rows);
                     cands.retain(|c| !moving.iter().any(|m| (m - c).abs() < 1e-9));
                     cands.push(time.seconds());
                     target = snap_time(&cands, target, 8.0 / pps);
@@ -3430,13 +4475,25 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
         }
     }
+}
+
+/// Releasing the key marquee selects the keys inside it.
+fn key_box_select(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &mut Rw) {
+    let tm = g.tl.tm;
+    let rows_rect = g.tl.rows_rect;
+    let rh = g.tl.rh;
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
+    let rows = &g.tl.rows;
+    let actions = &mut g.tl.actions;
+    let empty = g.empty.clone();
     if empty.drag_stopped()
         && let Some(br) = ctx.data(|d| d.get_temp::<Rect>(egui::Id::unique("tl-box")))
     {
         ctx.data_mut(|d| d.remove::<Rect>(egui::Id::unique("tl-box")));
         let mut keys = vec![];
         let mut yy = rows_rect.min.y - app.ui.timeline.scroll_y;
-        for row in &rows {
+        for row in rows.iter() {
             let cy = yy + rh / 2.0;
             yy += row_height(row, rh);
             if let RowKind::Prop { uid } = row.kind
@@ -3461,8 +4518,17 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             actions.push(("keys.select".into(), json!({"keys": keys, "add": mods.shift, "selectProperties": true})));
         }
     }
+}
 
-    // CTI.
+fn current_time_indicator(app: &mut EffectcraftApp, g: &Rw) {
+    let t = g.tl.t;
+    let time = g.tl.time;
+    let rect = g.tl.rect;
+    let graph_x0 = g.tl.graph_x0;
+    let tm = g.tl.tm;
+    let rows_rect = g.tl.rows_rect;
+    let ruler = g.tl.ruler;
+    let p = g.tl.p.clone();
     let cx = tm.x(time.seconds());
     if cx >= graph_x0 && cx <= rect.max.x {
         p.line_segment([pos2(cx, ruler.min.y + 12.0), pos2(cx, rows_rect.max.y)], Stroke::new(1.0, t.cti));
@@ -3476,9 +4542,19 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         p.add(egui::Shape::convex_polygon(head, t.cti, Stroke::NONE));
         app.auto.add("timeline.cti", Rect::from_center_size(pos2(cx, ruler.center().y), vec2(12.0, 20.0)), "Current time indicator");
     }
-    let _ = graph_rect;
+}
 
-    // Footer.
+/// The footer: scroll bars, the switches / modes toggle and render time.
+fn footer_bar(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Rw) -> Rect {
+    let t = g.tl.t;
+    let rect = g.tl.rect;
+    let footer_h = g.tl.footer_h;
+    let overflow = g.tl.overflow;
+    let oscroll = g.tl.oscroll;
+    let graph_x0 = g.tl.graph_x0;
+    let rows_rect = g.tl.rows_rect;
+    let max_scroll = g.tl.max_scroll;
+    let p = g.tl.p.clone();
     let footer = Rect::from_min_max(pos2(rect.min.x, rect.max.y - footer_h), rect.max);
     p.rect_filled(footer, 0.0, t.panel_bg);
     p.line_segment([footer.left_top(), footer.right_top()], Stroke::new(1.0, t.separator));
@@ -3514,6 +4590,20 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         t.text_faint,
     );
     // Zoom slider.
+    footer
+}
+
+/// The zoom buttons and slider.
+fn footer_zoom(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Rw, footer: Rect) {
+    let t = g.tl.t;
+    let time = g.tl.time;
+    let rect = g.tl.rect;
+    let graph_x0 = g.tl.graph_x0;
+    let fit_pps = g.tl.fit_pps;
+    let pps = g.tl.pps;
+    let tm = g.tl.tm;
+    let comp = g.tl.comp.clone();
+    let p = g.tl.p.clone();
     let zs = Rect::from_min_max(pos2(graph_x0 + 30.0, footer.center().y - 2.0), pos2((graph_x0 + 230.0).min(rect.max.x - 30.0), footer.center().y + 2.0));
     // Zoom out / zoom in buttons either side of the slider: the `-` / `=` steps. Everything here
     // zooms around the CTI and sets the one time zoom the layer bars and the Graph Editor share.
@@ -3545,16 +4635,34 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         let f = ((pt.x - zs.min.x) / zs.width().max(1.0)).clamp(0.0, 1.0) as f64;
         set_zoom(&mut app.ui.timeline, &comp, fit_pps * (maxpps / fit_pps).powf(f), fit_pps, cti, cti_px);
     }
+}
 
+fn comp_markers_ui(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Rw) {
+    let graph_x0 = g.tl.graph_x0;
+    let tm = g.tl.tm;
+    let rows_rect = g.tl.rows_rect;
+    let ruler = g.tl.ruler;
+    let bin = g.tl.bin;
+    let comp = g.tl.comp.clone();
     // Composition markers in the ruler; protected regions shade the layer rows.
     let mstrip = Rect::from_min_max(pos2(graph_x0, ruler.max.y - 12.0), pos2(bin.min.x, ruler.max.y));
     let mrows = rows_rect.intersect(Rect::from_min_max(pos2(graph_x0, rows_rect.min.y), rows_rect.max));
     super::markers_ui::comp_markers(app, ui, &comp, tm, mstrip, mrows);
     super::markers_ui::marker_bin(app, ui, &comp, tm, bin, mstrip);
+}
 
-    // Spacebar held: the Hand tool. Dragging pans the rows vertically as well as scrolling the
-    // time graph in time when zoomed in (registered last, so it takes the drag from the bars,
-    // keys and markers there).
+/// Spacebar held: the Hand tool.
+fn hand_tool_pan(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: &Rw) {
+    let rect = g.tl.rect;
+    let graph_x0 = g.tl.graph_x0;
+    let graph_x1 = g.tl.graph_x1;
+    let pps = g.tl.pps;
+    let tm = g.tl.tm;
+    let rows_rect = g.tl.rows_rect;
+    let ruler = g.tl.ruler;
+    let max_scroll = g.tl.max_scroll;
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
     if super::space_hand(&ctx) {
         let area = Rect::from_min_max(pos2(graph_x0, ruler.min.y), pos2(rect.max.x, rows_rect.max.y));
         let hand = ui.interact(area, egui::Id::unique("tl-hand"), Sense::drag());
@@ -3572,184 +4680,130 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
         }
     }
+}
 
-    // Drop targets: effects and animation presets from Effects & Presets go on the layer under the
-    // pointer. Footage and
-    // comps from the Project panel and files from the Media Browser go where they are dropped: a
-    // line shows the place in the stack, and over the time graph a marker shows the In point too
-    // (Shift: at the current time).
-    if let Some(payload) = egui::DragAndDrop::payload::<crate::panels::DragPayload>(&ctx)
-        && !matches!(*payload, crate::panels::DragPayload::Property { .. })
-        && let Some(ptr) = ctx.input(|i| i.pointer.hover_pos()).filter(|_| ui.rect_contains_pointer(rows_rect))
-    {
-        let released = ctx.input(|i| i.pointer.any_released());
-        // Alt/Option-drag from the Project panel replaces the source of the layer under the
-        // pointer (After Effects). The shortcut replaces every selected layer instead.
-        let alt_item = ctx.input(|i| i.modifiers.alt) && matches!(payload.as_ref(), crate::panels::DragPayload::Item(_));
-        if alt_item {
-            if let crate::panels::DragPayload::Item(id) = payload.as_ref() {
-                let target = hit_rows.iter().find(|(r, _)| ptr.y >= r.min.y && ptr.y < r.max.y).map(|(_, row)| row.layer);
-                if let Some(l) = target
-                    && replace_source_target(app, cid, ItemId(*id), l, &comp)
-                    && let Some(span) = hit_rows.iter().filter(|(_, row)| row.layer == l).map(|(r, _)| *r).reduce(|a, b| a.union(b))
-                {
-                    let lit = span.intersect(rows_rect);
-                    let rp = p.with_clip_rect(rows_rect);
-                    rp.rect_filled(lit, 0.0, t.accent.gamma_multiply(0.18));
-                    rp.rect_stroke(lit, 0.0, Stroke::new(2.0, t.accent), StrokeKind::Inside);
-                    app.auto.add("timeline.replaceSourceTarget", lit, "Replace the layer's source");
-                    if released {
-                        actions.push(("layer.replaceSource".into(), json!({"layers": [l.0], "item": *id, "fixExpressions": false})));
-                    }
-                }
-            }
-        } else if matches!(payload.as_ref(), crate::panels::DragPayload::Effect(_) | crate::panels::DragPayload::Preset { .. }) {
-            let target = hit_rows.iter().find(|(r, _)| ptr.y >= r.min.y && ptr.y < r.max.y).map(|(_, row)| row.layer);
-            // The layer the effect would land on (its row and its open properties) is the one
-            // that lights up, not the whole timeline.
-            if let Some(l) = target
-                && let Some(span) = hit_rows.iter().filter(|(_, row)| row.layer == l).map(|(r, _)| *r).reduce(|a, b| a.union(b))
-            {
-                let lit = span.intersect(rows_rect);
-                let rp = p.with_clip_rect(rows_rect);
-                rp.rect_filled(lit, 0.0, t.accent.gamma_multiply(0.18));
-                rp.rect_stroke(lit, 0.0, Stroke::new(2.0, t.accent), StrokeKind::Inside);
-                app.auto.add("timeline.dropTarget", lit, "Drop target layer");
-            }
-            if released && let Some(l) = target {
-                match payload.as_ref() {
-                    crate::panels::DragPayload::Effect(e) => actions.push(("effect.apply".into(), json!({"effect": e, "layers": [l.0]}))),
-                    crate::panels::DragPayload::Preset { preset, .. } => {
-                        let (id, params) = preset.apply_to(l.0);
-                        actions.push((id.into(), params));
-                    }
-                    _ => {}
-                }
-            }
-        } else {
-            let layer_rows: Vec<(Rect, LayerId)> = hit_rows.iter().filter(|(_, r)| matches!(r.kind, RowKind::Layer)).map(|(rr, r)| (*rr, r.layer)).collect();
-            let (at, line_y) = insertion(&layer_rows, ptr.y, rows_rect.min.y);
-            let index = match at.and_then(|i| layer_rows.get(i)) {
-                Some((_, l)) => comp.index_of(*l).unwrap_or(1),
-                None => layer_rows.last().and_then(|(_, l)| comp.index_of(*l)).unwrap_or(comp.layers.len()) + 1,
-            };
-            let start = (ptr.x >= graph_x0 && !graph_on).then(|| {
-                let t = if ctx.input(|i| i.modifiers.shift) { time } else { Tick::from_seconds_f64(tm.t(ptr.x)) };
-                comp.frame_rate.snap_nearest(t).clamp(Tick::ZERO, comp.duration - comp.frame_duration())
-            });
+/// Alt-drag of an item over a layer: replace its source.
+fn drop_replace_source(app: &mut EffectcraftApp, g: &mut Rw, payload: &std::sync::Arc<crate::panels::DragPayload>, ptr: Pos2, released: bool) {
+    let t = g.tl.t;
+    let cid = g.tl.cid;
+    let rows_rect = g.tl.rows_rect;
+    let comp = g.tl.comp.clone();
+    let p = g.tl.p.clone();
+    let actions = &mut g.tl.actions;
+    let hit_rows = &mut g.hit_rows;
+    if let crate::panels::DragPayload::Item(id) = payload.as_ref() {
+        let target = hit_rows.iter().find(|(r, _)| ptr.y >= r.min.y && ptr.y < r.max.y).map(|(_, row)| row.layer);
+        if let Some(l) = target
+            && replace_source_target(app, cid, ItemId(*id), l, &comp)
+            && let Some(span) = hit_rows.iter().filter(|(_, row)| row.layer == l).map(|(r, _)| *r).reduce(|a, b| a.union(b))
+        {
+            let lit = span.intersect(rows_rect);
             let rp = p.with_clip_rect(rows_rect);
-            rp.line_segment([pos2(rect.min.x, line_y), pos2(rows_rect.max.x, line_y)], Stroke::new(2.0, t.accent));
-            if let Some(s) = start {
-                let x = tm.x(s.seconds());
-                rp.line_segment([pos2(x, rows_rect.min.y), pos2(x, rows_rect.max.y)], Stroke::new(1.0, t.accent));
-                // The In point's time in a tag beside the marker.
-                let g = rp.layout_no_wrap(super::timecode(&app.session, &comp, s), Tokens::ui(11.0), Color32::WHITE);
-                let tag = Align2::LEFT_BOTTOM.anchor_size(pos2(x + 4.0, line_y - 3.0), g.size());
-                rp.rect_filled(tag.expand(2.0), 2.0, t.accent);
-                rp.galley(tag.min, g, Color32::WHITE);
-            }
+            rp.rect_filled(lit, 0.0, t.accent.gamma_multiply(0.18));
+            rp.rect_stroke(lit, 0.0, Stroke::new(2.0, t.accent), StrokeKind::Inside);
+            app.auto.add("timeline.replaceSourceTarget", lit, "Replace the layer's source");
             if released {
-                let time = json!(start.map(Tick::seconds));
-                match payload.as_ref() {
-                    crate::panels::DragPayload::Item(id) => {
-                        // Insert each selected item at the drop point, in selection order.
-                        for (offset, item) in crate::panels::project_drop_items(app, *id).into_iter().enumerate() {
-                            actions.push(("layer.addItem".into(), json!({"item": item, "index": index.saturating_add(offset), "time": time.clone()})));
-                        }
-                    }
-                    crate::panels::DragPayload::Files(paths) => {
-                        actions.push(("mediaBrowser.import".into(), json!({"paths": paths, "addToComp": true, "index": index, "time": time})))
-                    }
-                    crate::panels::DragPayload::Effect(_) | crate::panels::DragPayload::Preset { .. } | crate::panels::DragPayload::Property { .. } => {}
-                }
+                actions.push(("layer.replaceSource".into(), json!({"layers": [l.0], "item": *id, "fixExpressions": false})));
             }
         }
-        if released {
-            egui::DragAndDrop::clear_payload(&ctx);
-        }
     }
+}
 
-    // Apply.
-    for a in ui_actions {
-        match a {
-            UiAct::ToggleLayer(id, all) => {
-                let tl = &mut app.ui.timeline;
-                // Twirled by hand, the layer shows its whole tree again.
-                tl.reveal.clear();
-                tl.layer_reveal.remove(&id);
-                tl.full_groups.remove(&id);
-                let open = !tl.open_layers.contains(&id);
-                if open {
-                    tl.open_layers.insert(id);
-                } else {
-                    tl.open_layers.remove(&id);
-                }
-                if all && let Some(l) = comp.layer(LayerId(id)) {
-                    let mut uids = vec![];
-                    walk_groups(&l.props, &mut uids);
-                    for u in uids {
-                        if open {
-                            tl.open_groups.insert(u);
-                        } else {
-                            tl.open_groups.remove(&u);
-                        }
-                    }
-                }
-            }
-            UiAct::ToggleGroup(layer, uid, all) => {
-                let tl = &mut app.ui.timeline;
-                tl.toggle_group(layer, uid);
-                let open = tl.open_groups.contains(&uid);
-                if all && let Some(g) = comp.layer(LayerId(layer)).and_then(|l| find_group(&l.props, uid)) {
-                    let mut uids = vec![];
-                    walk_groups(g, &mut uids);
-                    for u in uids {
-                        if open {
-                            tl.open_groups.insert(u);
-                        } else {
-                            tl.open_groups.remove(&u);
-                        }
-                    }
-                }
-            }
-            UiAct::SetTime(tt) => app.session.set_time(tt),
-            UiAct::EndMerge => app.session.history.merge_key = None,
-            UiAct::ChangeRenderer => {
-                if super::dialogs::open_comp_settings(app).is_ok() {
-                    app.dialog_state.comp.tab = super::comp_settings::Tab::Renderer;
-                }
+/// Effects and presets drop onto the layer under the pointer.
+fn drop_on_layer(app: &mut EffectcraftApp, g: &mut Rw, payload: &std::sync::Arc<crate::panels::DragPayload>, ptr: Pos2, released: bool) {
+    let t = g.tl.t;
+    let rows_rect = g.tl.rows_rect;
+    let p = g.tl.p.clone();
+    let actions = &mut g.tl.actions;
+    let hit_rows = &mut g.hit_rows;
+    let target = hit_rows.iter().find(|(r, _)| ptr.y >= r.min.y && ptr.y < r.max.y).map(|(_, row)| row.layer);
+    // The layer the effect would land on (its row and its open properties) is the one
+    // that lights up, not the whole timeline.
+    if let Some(l) = target
+        && let Some(span) = hit_rows.iter().filter(|(_, row)| row.layer == l).map(|(r, _)| *r).reduce(|a, b| a.union(b))
+    {
+        let lit = span.intersect(rows_rect);
+        let rp = p.with_clip_rect(rows_rect);
+        rp.rect_filled(lit, 0.0, t.accent.gamma_multiply(0.18));
+        rp.rect_stroke(lit, 0.0, Stroke::new(2.0, t.accent), StrokeKind::Inside);
+        app.auto.add("timeline.dropTarget", lit, "Drop target layer");
+    }
+    if released && let Some(l) = target {
+        match payload.as_ref() {
+            crate::panels::DragPayload::Effect(e) => actions.push(("effect.apply".into(), json!({"effect": e, "layers": [l.0]}))),
+            crate::panels::DragPayload::Preset { preset, .. } => {
+                let (id, params) = preset.apply_to(l.0);
+                actions.push((id.into(), params));
             }
+            _ => {}
         }
     }
-    if ui.input(|i| i.pointer.primary_down()) && actions.iter().any(|(id, _)| id == "prop.set") {
-        app.ui.viewer.property_interacting = true;
-        ctx.request_repaint();
+}
+
+/// Footage and files drop into the stack: a line shows the place.
+fn drop_insert_layers(app: &mut EffectcraftApp, g: &mut Rw, payload: &std::sync::Arc<crate::panels::DragPayload>, ptr: Pos2, released: bool) {
+    let t = g.tl.t;
+    let time = g.tl.time;
+    let rect = g.tl.rect;
+    let graph_x0 = g.tl.graph_x0;
+    let tm = g.tl.tm;
+    let rows_rect = g.tl.rows_rect;
+    let ctx = g.tl.ctx.clone();
+    let comp = g.tl.comp.clone();
+    let p = g.tl.p.clone();
+    let actions = &mut g.tl.actions;
+    let graph_on = g.graph_on;
+    let hit_rows = &mut g.hit_rows;
+    let layer_rows: Vec<(Rect, LayerId)> = hit_rows.iter().filter(|(_, r)| matches!(r.kind, RowKind::Layer)).map(|(rr, r)| (*rr, r.layer)).collect();
+    let (at, line_y) = insertion(&layer_rows, ptr.y, rows_rect.min.y);
+    let index = match at.and_then(|i| layer_rows.get(i)) {
+        Some((_, l)) => comp.index_of(*l).unwrap_or(1),
+        None => layer_rows.last().and_then(|(_, l)| comp.index_of(*l)).unwrap_or(comp.layers.len()) + 1,
+    };
+    let start = (ptr.x >= graph_x0 && !graph_on).then(|| {
+        let t = if ctx.input(|i| i.modifiers.shift) { time } else { Tick::from_seconds_f64(tm.t(ptr.x)) };
+        comp.frame_rate.snap_nearest(t).clamp(Tick::ZERO, comp.duration - comp.frame_duration())
+    });
+    let rp = p.with_clip_rect(rows_rect);
+    rp.line_segment([pos2(rect.min.x, line_y), pos2(rows_rect.max.x, line_y)], Stroke::new(2.0, t.accent));
+    if let Some(s) = start {
+        let x = tm.x(s.seconds());
+        rp.line_segment([pos2(x, rows_rect.min.y), pos2(x, rows_rect.max.y)], Stroke::new(1.0, t.accent));
+        // The In point's time in a tag beside the marker.
+        let g = rp.layout_no_wrap(super::timecode(&app.session, &comp, s), Tokens::ui(11.0), Color32::WHITE);
+        let tag = Align2::LEFT_BOTTOM.anchor_size(pos2(x + 4.0, line_y - 3.0), g.size());
+        rp.rect_filled(tag.expand(2.0), 2.0, t.accent);
+        rp.galley(tag.min, g, Color32::WHITE);
     }
-    for (id, params) in actions {
-        if id == "__endMerge" {
-            app.session.history.merge_key = None;
-            continue;
-        }
-        if let Err(e) = crate::menus::invoke(app, &ctx, &id, params) {
-            app.ui.status = e;
+    if released {
+        let time = json!(start.map(Tick::seconds));
+        match payload.as_ref() {
+            crate::panels::DragPayload::Item(id) => {
+                // Insert each selected item at the drop point, in selection order.
+                for (offset, item) in crate::panels::project_drop_items(app, *id).into_iter().enumerate() {
+                    actions.push(("layer.addItem".into(), json!({"item": item, "index": index.saturating_add(offset), "time": time.clone()})));
+                }
+            }
+            crate::panels::DragPayload::Files(paths) => {
+                actions.push(("mediaBrowser.import".into(), json!({"paths": paths, "addToComp": true, "index": index, "time": time})))
+            }
+            crate::panels::DragPayload::Effect(_) | crate::panels::DragPayload::Preset { .. } | crate::panels::DragPayload::Property { .. } => {}
         }
     }
 }
 
 /// The optional per-layer cells: Comment (double-click to edit), In / Out / Duration (drag to
 /// change by frames), Stretch (click: Time Stretch dialog).
-#[allow(clippy::too_many_arguments)]
 fn layer_cells(
     app: &mut EffectcraftApp,
     ui: &mut egui::Ui,
     lp: &egui::Painter,
     cw: &Cols,
     comp: &Comp,
-    layer: &Layer,
-    r: Rect,
-    cy: f32,
+    rc: &RowCtx<'_>,
     actions: &mut Vec<(String, serde_json::Value)>,
 ) {
+    let (layer, r, cy) = (rc.layer, rc.r, rc.cy);
     let t = app.tokens;
     let ctx = ui.ctx().clone();
     let lid = layer.id.0;
@@ -3863,17 +4917,16 @@ fn find_group(g: &PropGroup, uid: u64) -> Option<&PropGroup> {
 }
 
 /// A stroke's Dashes "+" / "−" buttons (add or remove a Dash/Gap pair).
-#[allow(clippy::too_many_arguments)]
 fn dash_buttons(
     app: &mut EffectcraftApp,
     ui: &mut egui::Ui,
     p: &egui::Painter,
     layer: &Layer,
     uid: u64,
-    x: f32,
-    cy: f32,
+    at: Pos2,
     actions: &mut Vec<(String, serde_json::Value)>,
 ) {
+    let (x, cy) = (at.x, at.y);
     if !matches!(layer.source, LayerSource::Shape) || layer.props.find_group(uid).is_none_or(|g| g.match_id != "dashes") {
         return;
     }
@@ -3926,17 +4979,16 @@ const SHAPE_ADD_ITEMS: &[(&str, &str)] = &[
 
 /// A shape layer's Contents "Add:" pop-up menu: adds a shape, paint or path operation to the
 /// selected shape group, else to the layer's contents.
-#[allow(clippy::too_many_arguments)]
 fn shape_add_popup(
     app: &mut EffectcraftApp,
     ui: &mut egui::Ui,
     p: &egui::Painter,
     layer: &Layer,
     uid: u64,
-    x: f32,
-    cy: f32,
+    at: Pos2,
     actions: &mut Vec<(String, serde_json::Value)>,
 ) {
+    let (x, cy) = (at.x, at.y);
     if !matches!(layer.source, LayerSource::Shape) || layer.props.sub("contents").is_none_or(|c| c.uid != uid) {
         return;
     }
@@ -3969,17 +5021,16 @@ fn shape_add_popup(
 }
 
 /// The Text group's "Animate:" and an animator's "Add:" pop-up menus (AE's twirl-down menus).
-#[allow(clippy::too_many_arguments)]
 fn text_anim_popups(
     app: &mut EffectcraftApp,
     ui: &mut egui::Ui,
     p: &egui::Painter,
     layer: &Layer,
     uid: u64,
-    x: f32,
-    cy: f32,
+    at: Pos2,
     actions: &mut Vec<(String, serde_json::Value)>,
 ) {
+    let (x, cy) = (at.x, at.y);
     use effectcraft_engine::project::build::TEXT_ANIMATOR_KINDS;
     if !matches!(layer.source, LayerSource::Text) {
         return;
@@ -4160,7 +5211,6 @@ impl LayerMenuCaps {
 /// A layer row's or bar's context menu. As in After Effects, right-clicking a layer that is part
 /// of the selection keeps the selection and the menu acts on all of it; right-clicking an
 /// unselected layer selects only that layer.
-#[allow(clippy::too_many_arguments)]
 fn layer_context_menu(
     resp: &egui::Response,
     comp: &Comp,
@@ -4337,738 +5387,270 @@ fn fmt_num(v: f64, d: usize) -> String {
     format!("{v:.d$}")
 }
 
-/// Inline value editor for a property row; pushes `prop.set` actions. Returns the rects of a
-/// multi-dimension value's fields, one per dimension (none for other values).
-fn value_editor(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    p: &egui::Painter,
-    layer: &Layer,
-    prop: &Property,
-    value: &Value,
+/// What the property value editors share: where to draw, what they edit, and how a change is
+/// worded as a `prop.set` command.
+struct ValueEdit<'a> {
+    p: &'a egui::Painter,
+    layer: &'a Layer,
+    prop: &'a Property,
     at: Pos2,
-    actions: &mut Vec<(String, serde_json::Value)>,
-) -> Vec<Rect> {
-    let t = app.tokens;
-    let uid = prop.uid;
-    let mut dims = vec![];
-    let merge = format!("scrub-{uid}");
-    // With several layers selected the edit applies to all of them (#491): a scrub by the same
-    // change, a typed value as it is.
-    let scrub = ui.ctx().dragged_id().is_some() && ui.input(|i| i.pointer.is_decidedly_dragging());
-    // Proportional Scrubbing (After Effects 26.2): Ctrl+Alt (Cmd+Opt) spreads the change over the
-    // selected layers by selection order, the first unchanged and the last by all of it.
-    let proportional = scrub && ui.input(|i| widgets::proportional_scrub(i.modifiers));
-    let set = |actions: &mut Vec<(String, serde_json::Value)>, v: serde_json::Value| {
+    uid: u64,
+    merge: String,
+    scrub: bool,
+    proportional: bool,
+}
+
+impl<'a> ValueEdit<'a> {
+    /// The editor of `prop` on `layer` at `at`; `ui` says whether a scrub is under way.
+    fn new(ui: &egui::Ui, p: &'a egui::Painter, layer: &'a Layer, prop: &'a Property, at: Pos2) -> Self {
+        let uid = prop.uid;
+        // With several layers selected the edit applies to all of them (#491): a scrub by the same
+        // change, a typed value as it is.
+        let scrub = ui.ctx().dragged_id().is_some() && ui.input(|i| i.pointer.is_decidedly_dragging());
+        // Proportional Scrubbing (After Effects 26.2): Ctrl+Alt (Cmd+Opt) spreads the change over the
+        // selected layers by selection order, the first unchanged and the last by all of it.
+        let proportional = scrub && ui.input(|i| widgets::proportional_scrub(i.modifiers));
+        Self { p, layer, prop, at, uid, merge: format!("scrub-{uid}"), scrub, proportional }
+    }
+
+    /// Queues the `prop.set` of one edit.
+    fn set(&self, actions: &mut Vec<(String, serde_json::Value)>, v: serde_json::Value) {
         actions.push((
             "prop.set".into(),
-            json!({"layer": layer.id.0, "prop": uid, "value": v, "merge": merge, "selected": true, "offset": scrub, "proportional": proportional}),
+            json!({"layer": self.layer.id.0, "prop": self.uid, "value": v, "merge": self.merge, "selected": true, "offset": self.scrub, "proportional": self.proportional}),
         ))
-    };
-    let is_3d = layer.is_3d();
-    let mut x = at.x;
-    let y = at.y - 9.0;
+    }
+}
+
+/// Inline value editor for a property row; pushes `prop.set` actions. Returns the rects of a
+/// multi-dimension value's fields, one per dimension (none for other values).
+fn value_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, ve: &ValueEdit<'_>, value: &Value, actions: &mut Vec<(String, serde_json::Value)>) -> Vec<Rect> {
     match value {
-        Value::Scalar(v) => {
-            let (min, max, dec, speed) = match &prop.ui {
-                ParamUi::Slider { min, max, decimals, .. } => (*min, *max, *decimals as usize, widgets::slider_scrub_speed(&prop.ui)),
-                ParamUi::Percent => (-1e6, 1e6, 1, 0.5),
-                _ => (-1e9, 1e9, 1, 1.0),
-            };
-            if matches!(prop.ui, ParamUi::Angle) {
-                let (rr, dr, nv) = super::fx_widgets::angle_field(ui, pos2(x, y), egui::Id::unique(("v", uid, 0)), *v, 1, &t);
-                app.auto.add(&format!("timeline.prop.{uid}.value"), dr, &prop.name);
-                app.auto.add(&format!("timeline.prop.{uid}.revolutions"), rr, &prop.name);
-                if let Some(nv) = nv {
-                    set(actions, json!(nv));
-                }
-            } else {
-                // A Range Selector's Start, End and Offset count characters with Units = Index (#1814).
-                let pct = (matches!(prop.ui, ParamUi::Percent) || prop.match_id == "opacity") && !effectcraft_engine::render::text::in_index_units(layer, uid);
-                let suffix = if pct { "%" } else { "" };
-                let (r, nv, _) = widgets::hot_number_at(ui, pos2(x, y), egui::Id::unique(("v", uid, 0)), *v, speed, (min, max), dec.max(1), suffix, &t);
-                app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
-                if let Some(nv) = nv {
-                    set(actions, json!(nv));
-                }
-            }
-        }
-        Value::Vec2(_) | Value::Vec3(_) => {
-            let c = value.components();
-            let n = if prop.shown_dims > 0 && !(is_3d && c.len() == 3) { prop.shown_dims as usize } else { c.len() };
-            let pct = matches!(prop.ui, ParamUi::Percent);
-            // Mask Feather: two linked values, never negative (as in After Effects, #203).
-            let feather = prop.match_id == "feather" && layer.props.parent_of(uid).is_some_and(|g| matches!(g.kind, GroupKind::Mask { .. }));
-            let range = if feather { (0.0, 1e9) } else { (-1e9, 1e9) };
-            // Scale and Mask Feather: the chain link (Constrain Proportions, on by default).
-            let linkable = feather || (pct && prop.match_id == "scale");
-            let linked = linkable && !app.ui.timeline.unlinked.contains(&uid);
-            if linkable {
-                let lr = Rect::from_center_size(pos2(x + 7.0, at.y), vec2(14.0, 14.0));
-                let resp = ui.interact(lr, egui::Id::unique(("tl-link", uid)), Sense::click()).on_hover_text(crate::i18n::tr("Constrain Proportions"));
-                icons::paint(p, lr, Icon::Link, if linked { t.accent } else { t.text_faint });
-                app.auto.add(&format!("timeline.prop.{uid}.link"), lr, "Constrain Proportions");
-                if resp.clicked() && !app.ui.timeline.unlinked.remove(&uid) {
-                    app.ui.timeline.unlinked.insert(uid);
-                }
-                x += 18.0;
-            }
-            for d in 0..n.min(c.len()) {
-                let suffix = if pct && d + 1 == n { "%" } else { "" };
-                let (r, nv, _) =
-                    widgets::hot_number_at(ui, pos2(x, y), egui::Id::unique(("v", uid, d)), c[d], if pct { 0.5 } else { 1.0 }, range, 1, suffix, &t);
-                app.auto.add(&format!("timeline.prop.{uid}.value.{d}"), r, &prop.name);
-                dims.push(r);
-                if let Some(nv) = nv {
-                    let mut nc = c.clone();
-                    // Alt edits one value of a linked pair (Ctrl+Alt is a proportional scrub).
-                    let shown = if linked && !ui.input(|i| i.modifiers.alt && !widgets::proportional_scrub(i.modifiers)) { n.min(c.len()) } else { 1 };
-                    let from = if shown == 1 { d } else { 0 };
-                    for (e, v) in widgets::constrained(c.get(from..from + shown).unwrap_or_default(), d - from, nv).into_iter().enumerate() {
-                        if let Some(slot) = nc.get_mut(from + e) {
-                            *slot = v;
-                        }
-                    }
-                    set(actions, json!(nc));
-                    // Typed into these components only: other selected layers keep the rest of
-                    // their own value (#1434).
-                    if let Some((_, a)) = actions.last_mut() {
-                        a["dims"] = json!((from..from + shown).collect::<Vec<_>>());
-                    }
-                }
-                x = r.max.x + if d + 1 < n { 2.0 } else { 0.0 };
-                if d + 1 < n {
-                    p.text(pos2(x, at.y), Align2::LEFT_CENTER, ",", Tokens::ui(12.0), t.hot_text);
-                    x += 6.0;
-                }
-            }
-        }
-        Value::Color(c) => {
-            let r = Rect::from_min_size(pos2(x, at.y - 7.0), vec2(26.0, 14.0));
-            let resp = widgets::swatch(ui, r, [c[0] as f32, c[1] as f32, c[2] as f32, 1.0], egui::Id::unique(("sw", uid)), &t);
-            app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
-            let pop = egui::Id::unique(("cpop", uid));
-            if resp.clicked() {
-                widgets::open_popup(ui, pop);
-            }
-            // The eyedropper after the swatch samples the Composition panel (shape Fill and
-            // Stroke colours, text and effect colours), as in After Effects' Timeline (#633).
-            let er = Rect::from_center_size(pos2(r.max.x + 12.0, at.y), vec2(16.0, 16.0));
-            let active = app.ui.fx_pick.as_ref().is_some_and(|k| k.prop == uid && k.kind == "color");
-            if super::fx_widgets::eyedropper_button(ui, er, active, egui::Id::unique(("tl-eye", uid)), &t)
-                .on_hover_text(crate::i18n::tr("Eyedropper: click, then click in the Composition panel"))
-                .clicked()
-            {
-                super::effect_controls::toggle_pick(app, "color", layer, prop);
-            }
-            app.auto.add(&format!("timeline.prop.{uid}.eyedropper"), er, &prop.name);
-            let mut rgb = [c[0] as f32, c[1] as f32, c[2] as f32];
-            if crate::widgets::color_popup(ui, pop, r.left_bottom(), &mut rgb) {
-                set(actions, json!([rgb[0], rgb[1], rgb[2], 1.0]));
-            }
-        }
-        Value::Bool(b) => {
-            let r = Rect::from_min_size(pos2(x, at.y - 8.0), vec2(16.0, 16.0));
-            if widgets::checkbox(ui, r, *b, &t, egui::Id::unique(("cb", uid))).clicked() {
-                set(actions, json!(!b));
-            }
-            app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
-        }
-        Value::Enum(i) => {
-            // Text Path Options ▸ Path lists the layer's masks.
-            let mask_opts: Option<Vec<String>> = layer
-                .props
-                .prop("text/pathOptions/path")
-                .filter(|q| q.uid == uid)
-                .map(|_| std::iter::once("None".to_string()).chain(layer.masks().into_iter().flat_map(|m| m.groups().map(|g| g.name.clone()))).collect());
-            let ui_opts = mask_opts.map(|options| ParamUi::Popup { options });
-            if let ParamUi::Popup { options } = ui_opts.as_ref().unwrap_or(&prop.ui) {
-                let r = Rect::from_min_size(pos2(x, at.y - 9.0), vec2(150.0, 18.0));
-                let label = options.get(*i as usize).cloned().unwrap_or_default();
-                let pop = egui::Id::unique(("epop", uid));
-                if widgets::dropdown(ui, r, &label, &t, egui::Id::unique(("en", uid))).clicked() {
-                    widgets::open_popup(ui, pop);
-                }
-                app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
-                if let Some(ni) = widgets::popup_menu(ui, pop, r.left_bottom(), options, Some(*i as usize)) {
-                    set(actions, json!(ni));
-                }
-            } else {
-                p.text(pos2(x, at.y), Align2::LEFT_CENTER, fmt_num(*i as f64, 0), Tokens::ui(12.0), t.hot_text);
-            }
-        }
+        Value::Scalar(_) => scalar_editor(app, ui, ve, actions, value),
+        Value::Vec2(_) | Value::Vec3(_) => return vector_editor(app, ui, ve, actions, value),
+        Value::Color(_) => color_editor(app, ui, ve, actions, value),
+        Value::Bool(_) => bool_editor(app, ui, ve, actions, value),
+        Value::Enum(_) => enum_editor(app, ui, ve, actions, value),
+        Value::Layer(_) => layer_editor(app, ui, ve, actions, value),
+        Value::Gradient(_) => gradient_editor(app, ui, ve, actions),
         Value::Path(_) => {
-            p.text(pos2(x, at.y), Align2::LEFT_CENTER, crate::i18n::tr("Shape…"), Tokens::ui(12.0), t.hot_text);
+            ve.p.text(pos2(ve.at.x, ve.at.y), Align2::LEFT_CENTER, crate::i18n::tr("Shape…"), Tokens::ui(12.0), app.tokens.hot_text);
         }
         Value::Text(_) => {}
-        Value::Layer(l) => {
-            // Layer references (a light's Source, a Displacement Map's layer…) pick from the
-            // comp's layers, as in Effect Controls; the choice is written through the same
-            // undoable prop.set as the other value arms.
-            let r = Rect::from_min_size(pos2(x, at.y - 9.0), vec2(150.0, 18.0));
-            if let Some(comp) = app.session.active_comp_arc()
-                && let Some(chosen) = widgets::layer_picker(ui, r, &comp.layers, *l, &t, egui::Id::unique(("tl-lay", uid)))
-            {
-                set(actions, chosen.map(|id| json!(id)).unwrap_or(serde_json::Value::Null));
-            }
-            app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
-        }
-        Value::Gradient(_) => {
-            // Opens the Gradient Editor at the current time (#612).
-            let r = p.text(pos2(x, at.y), Align2::LEFT_CENTER, crate::i18n::tr("Edit Gradient…"), Tokens::ui(12.0), t.hot_text);
-            let resp = ui.interact(r.expand(2.0), egui::Id::unique(("gradient-edit", uid)), Sense::click());
-            if resp.hovered() {
-                ui.ctx().set_cursor_icon(egui::CursorIcon::PointingHand);
-            }
-            app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
-            if resp.clicked() {
-                actions.push(("prop.editGradient".into(), json!({"layer": layer.id.0, "prop": uid})));
-            }
-        }
         Value::Str(s) => {
-            p.text(pos2(x, at.y), Align2::LEFT_CENTER, s.chars().take(30).collect::<String>(), Tokens::ui(12.0), t.text_dim);
+            ve.p.text(pos2(ve.at.x, ve.at.y), Align2::LEFT_CENTER, s.chars().take(30).collect::<String>(), Tokens::ui(12.0), app.tokens.text_dim);
+        }
+    }
+    Vec::new()
+}
+
+/// A number: scrubbable hot text, or the angle field.
+fn scalar_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, ve: &ValueEdit<'_>, actions: &mut Vec<(String, serde_json::Value)>, value: &Value) {
+    let Value::Scalar(v) = value else { return };
+    let (layer, prop, at, uid) = (ve.layer, ve.prop, ve.at, ve.uid);
+    let t = app.tokens;
+    let (x, y) = (at.x, at.y - 9.0);
+    let (min, max, dec, speed) = match &prop.ui {
+        ParamUi::Slider { min, max, decimals, .. } => (*min, *max, *decimals as usize, widgets::slider_scrub_speed(&prop.ui)),
+        ParamUi::Percent => (-1e6, 1e6, 1, 0.5),
+        _ => (-1e9, 1e9, 1, 1.0),
+    };
+    if matches!(prop.ui, ParamUi::Angle) {
+        let (rr, dr, nv) = super::fx_widgets::angle_field(ui, pos2(x, y), egui::Id::unique(("v", uid, 0)), *v, 1, &t);
+        app.auto.add(&format!("timeline.prop.{uid}.value"), dr, &prop.name);
+        app.auto.add(&format!("timeline.prop.{uid}.revolutions"), rr, &prop.name);
+        if let Some(nv) = nv {
+            ve.set(actions, json!(nv));
+        }
+    } else {
+        // A Range Selector's Start, End and Offset count characters with Units = Index (#1814).
+        let pct = (matches!(prop.ui, ParamUi::Percent) || prop.match_id == "opacity") && !effectcraft_engine::render::text::in_index_units(layer, uid);
+        let suffix = if pct { "%" } else { "" };
+        let (r, nv, _) = widgets::hot_number_at(
+            ui,
+            pos2(x, y),
+            egui::Id::unique(("v", uid, 0)),
+            *v,
+            &widgets::HotSpec { speed, range: (min, max), decimals: dec.max(1), suffix },
+            &t,
+        );
+        app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
+        if let Some(nv) = nv {
+            ve.set(actions, json!(nv));
+        }
+    }
+}
+
+/// A multi-dimension value: one hot-text field per dimension, with the link chain. Returns their rects.
+fn vector_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, ve: &ValueEdit<'_>, actions: &mut Vec<(String, serde_json::Value)>, value: &Value) -> Vec<Rect> {
+    let (p, layer, prop, at, uid) = (ve.p, ve.layer, ve.prop, ve.at, ve.uid);
+    let t = app.tokens;
+    let (mut x, y) = (at.x, at.y - 9.0);
+    let is_3d = layer.is_3d();
+    let mut dims = vec![];
+    let c = value.components();
+    let n = if prop.shown_dims > 0 && !(is_3d && c.len() == 3) { prop.shown_dims as usize } else { c.len() };
+    let pct = matches!(prop.ui, ParamUi::Percent);
+    // Mask Feather: two linked values, never negative (as in After Effects, #203).
+    let feather = prop.match_id == "feather" && layer.props.parent_of(uid).is_some_and(|g| matches!(g.kind, GroupKind::Mask { .. }));
+    let range = if feather { (0.0, 1e9) } else { (-1e9, 1e9) };
+    // Scale and Mask Feather: the chain link (Constrain Proportions, on by default).
+    let linkable = feather || (pct && prop.match_id == "scale");
+    let linked = linkable && !app.ui.timeline.unlinked.contains(&uid);
+    if linkable {
+        let lr = Rect::from_center_size(pos2(x + 7.0, at.y), vec2(14.0, 14.0));
+        let resp = ui.interact(lr, egui::Id::unique(("tl-link", uid)), Sense::click()).on_hover_text(crate::i18n::tr("Constrain Proportions"));
+        icons::paint(p, lr, Icon::Link, if linked { t.accent } else { t.text_faint });
+        app.auto.add(&format!("timeline.prop.{uid}.link"), lr, "Constrain Proportions");
+        if resp.clicked() && !app.ui.timeline.unlinked.remove(&uid) {
+            app.ui.timeline.unlinked.insert(uid);
+        }
+        x += 18.0;
+    }
+    for d in 0..n.min(c.len()) {
+        let suffix = if pct && d + 1 == n { "%" } else { "" };
+        let (r, nv, _) = widgets::hot_number_at(
+            ui,
+            pos2(x, y),
+            egui::Id::unique(("v", uid, d)),
+            c[d],
+            &widgets::HotSpec { speed: if pct { 0.5 } else { 1.0 }, range, decimals: 1, suffix },
+            &t,
+        );
+        app.auto.add(&format!("timeline.prop.{uid}.value.{d}"), r, &prop.name);
+        dims.push(r);
+        if let Some(nv) = nv {
+            let mut nc = c.clone();
+            // Alt edits one value of a linked pair (Ctrl+Alt is a proportional scrub).
+            let shown = if linked && !ui.input(|i| i.modifiers.alt && !widgets::proportional_scrub(i.modifiers)) { n.min(c.len()) } else { 1 };
+            let from = if shown == 1 { d } else { 0 };
+            for (e, v) in widgets::constrained(c.get(from..from + shown).unwrap_or_default(), d - from, nv).into_iter().enumerate() {
+                if let Some(slot) = nc.get_mut(from + e) {
+                    *slot = v;
+                }
+            }
+            ve.set(actions, json!(nc));
+            // Typed into these components only: other selected layers keep the rest of
+            // their own value (#1434).
+            if let Some((_, a)) = actions.last_mut() {
+                a["dims"] = json!((from..from + shown).collect::<Vec<_>>());
+            }
+        }
+        x = r.max.x + if d + 1 < n { 2.0 } else { 0.0 };
+        if d + 1 < n {
+            p.text(pos2(x, at.y), Align2::LEFT_CENTER, ",", Tokens::ui(12.0), t.hot_text);
+            x += 6.0;
         }
     }
     dims
 }
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    /// Alt/Option-drag takes the same Project items `layer.replaceSource` does: compositions,
-    /// footage and solids, never folders, data files or 3D models.
-    #[test]
-    fn replace_source_takes_visual_items_only() {
-        use effectcraft_engine::color::Label;
-        use effectcraft_engine::project::{Comp, Footage, Project, Solid};
-        use effectcraft_engine::time::{FrameRate, Tick};
-        let mut p = Project::default();
-        let l = Label::None;
-        let comp = p.add_item("C", l, None, ItemKind::Comp(Comp::new(10, 10, FrameRate::FPS_30, Tick::from_seconds_f64(1.0)).into()));
-        let folder = p.add_item("F", l, None, ItemKind::Folder);
-        let still = p.add_item("S", l, None, ItemKind::Footage(Footage { kind: FootageKind::Still, ..Default::default() }));
-        let data = p.add_item("D", l, None, ItemKind::Footage(Footage { kind: FootageKind::Data, ..Default::default() }));
-        let model = p.add_item("M", l, None, ItemKind::Footage(Footage { kind: FootageKind::Model, ..Default::default() }));
-        let solid = p.add_item("So", l, None, ItemKind::Solid(Solid { color: [0.0; 3], width: 10, height: 10, pixel_aspect: 1.0 }));
-        for (id, ok) in [(comp, true), (still, true), (solid, true), (folder, false), (data, false), (model, false)] {
-            assert_eq!(replaceable_item(p.item(id).unwrap()), ok, "{id:?}");
-        }
+/// A colour: swatch, eyedropper and picker.
+fn color_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, ve: &ValueEdit<'_>, actions: &mut Vec<(String, serde_json::Value)>, value: &Value) {
+    let Value::Color(c) = value else { return };
+    let (layer, prop, at, uid) = (ve.layer, ve.prop, ve.at, ve.uid);
+    let t = app.tokens;
+    let x = at.x;
+    let r = Rect::from_min_size(pos2(x, at.y - 7.0), vec2(26.0, 14.0));
+    let resp = widgets::swatch(ui, r, [c[0] as f32, c[1] as f32, c[2] as f32, 1.0], egui::Id::unique(("sw", uid)), &t);
+    app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
+    let pop = egui::Id::unique(("cpop", uid));
+    if resp.clicked() {
+        widgets::open_popup(ui, pop);
     }
-
-    /// Alt/Cmd-click twirls Audio's Waveform row (not in the property tree) with the rest.
-    #[test]
-    fn the_waveform_row_twirls_with_its_tree() {
-        let mut root = PropGroup::new(1, "", "");
-        let mut audio = PropGroup::new(2, "audio", "Audio");
-        audio.children.push(PropGroup::new(3, "x", "X").into());
-        root.children.push(audio.into());
-        let mut uids = vec![];
-        walk_groups(&root, &mut uids);
-        assert_eq!(uids, vec![2, WAVE_BIT | 2, 3]);
-        let mut uids = vec![];
-        walk_groups(find_group(&root, 2).unwrap(), &mut uids);
-        assert_eq!(uids, vec![WAVE_BIT | 2, 3]);
+    // The eyedropper after the swatch samples the Composition panel (shape Fill and
+    // Stroke colours, text and effect colours), as in After Effects' Timeline (#633).
+    let er = Rect::from_center_size(pos2(r.max.x + 12.0, at.y), vec2(16.0, 16.0));
+    let active = app.ui.fx_pick.as_ref().is_some_and(|k| k.prop == uid && k.kind == "color");
+    if super::fx_widgets::eyedropper_button(ui, er, active, egui::Id::unique(("tl-eye", uid)), &t)
+        .on_hover_text(crate::i18n::tr("Eyedropper: click, then click in the Composition panel"))
+        .clicked()
+    {
+        super::effect_controls::toggle_pick(app, "color", layer, prop);
     }
-
-    /// #710: with Time Display set to Frames the ruler labels are frame numbers (as under the
-    /// CTI, from Start Numbering Frames At); otherwise seconds:frames.
-    #[test]
-    fn ruler_labels_follow_the_time_display_style() {
-        use effectcraft_engine::project::{ProjectSettings, TimeDisplayStyle};
-        let mut st = ProjectSettings { time_display: TimeDisplayStyle::Timecode, frame_start: 0, ..ProjectSettings::default() };
-        assert_eq!(ruler_label(15, 30, &st), "00:15f");
-        assert_eq!(ruler_label(45, 30, &st), "01:15f");
-        assert_eq!(ruler_label(30 * 3600 + 31, 30, &st), "60:01:01f");
-        st.time_display = TimeDisplayStyle::Frames;
-        assert_eq!(ruler_label(0, 30, &st), "00000");
-        assert_eq!(ruler_label(45, 30, &st), "00045");
-        st.frame_start = 1;
-        assert_eq!(ruler_label(45, 30, &st), "00046");
-        assert_eq!(ruler_label(i64::MAX, 30, &st), format!("{:05}", i64::MAX));
-    }
-
-    /// #468: playback pages the view to the CTI; a scrub past either end scrolls that way.
-    #[test]
-    fn the_view_pages_to_the_cti() {
-        assert_eq!(page_to_cti(10.0, 5.0, 60.0, 12.0), 10.0, "in view: unchanged");
-        assert_eq!(page_to_cti(10.0, 5.0, 60.0, 16.0), 16.0, "past the right end: the page from the CTI");
-        assert_eq!(page_to_cti(10.0, 5.0, 60.0, 3.0), 3.0, "before the start");
-        assert_eq!(page_to_cti(10.0, 5.0, 60.0, 58.0), 55.0, "not past the comp's end");
-        assert_eq!(page_to_cti(10.0, 80.0, 60.0, 95.0), 0.0);
-        assert_eq!(page_to_cti(10.0, f64::NAN, 60.0, 95.0), 10.0);
-        assert_eq!(edge_scroll_speed_x(100.0, 500.0, 300.0), 0.0);
-        assert!(edge_scroll_speed_x(100.0, 500.0, 501.0) > 0.0 && edge_scroll_speed_x(100.0, 500.0, 99.0) < 0.0);
-        assert!(edge_scroll_speed_x(100.0, 500.0, 600.0) > edge_scroll_speed_x(100.0, 500.0, 520.0));
-    }
-
-    /// #864: picking only a mode in a layer's Track Matte menu sets a matte (the layer above);
-    /// it used to close the menu and change nothing.
-    #[test]
-    fn a_track_matte_mode_without_a_matte_takes_the_layer_above() {
-        let mut s = effectcraft_engine::Session::default();
-        s.execute("comp.new", json!({"name": "T", "width": 64, "height": 64, "duration": 1})).unwrap();
-        for name in ["Chain Bottom", "Matte", "Chain Top"] {
-            s.execute("layer.newSolid", json!({"name": name, "color": "#ffffff", "width": 64, "height": 64})).unwrap();
-        }
-        let find = |s: &effectcraft_engine::Session, n: &str| s.active_comp().unwrap().layers.iter().find(|l| l.name == n).unwrap().clone();
-        let (bottom, matte, top) = (find(&s, "Chain Bottom"), find(&s, "Matte"), find(&s, "Chain Top"));
-        let candidates = [top.id, matte.id];
-        let pick = |s: &mut effectcraft_engine::Session, name: &str, i: usize, choice: &str| {
-            let (id, params) = track_matte_pick(&find(s, name), &candidates, i, choice).expect("a menu item is an action");
-            s.execute(&id, params)
-        };
-        pick(&mut s, "Chain Bottom", 5, "Alpha Inverted Matte").unwrap();
-        let m = find(&s, "Chain Bottom").track_matte.expect("a matte");
-        assert_eq!((m.layer, m.kind), (matte.id, MatteKind::AlphaInverted));
-        assert!(!find(&s, "Matte").switches.video, "the matte layer is hidden");
-        // A mode change keeps the matte layer; a matte change keeps the mode.
-        pick(&mut s, "Chain Bottom", 6, "Luma Matte").unwrap();
-        assert_eq!(find(&s, "Chain Bottom").track_matte.map(|m| (m.layer, m.kind)), Some((matte.id, MatteKind::Luma)));
-        pick(&mut s, "Chain Bottom", 2, "1. Chain Top").unwrap();
-        assert_eq!(find(&s, "Chain Bottom").track_matte.map(|m| (m.layer, m.kind)), Some((top.id, MatteKind::Luma)));
-        assert!(s.undo());
-        assert_eq!(find(&s, "Chain Bottom").track_matte.map(|m| m.layer), Some(matte.id), "one undo step per pick");
-        // The top layer has nothing above it: an error for the status bar, not a silent no-op.
-        assert!(pick(&mut s, "Chain Top", 5, "Alpha Matte").is_err());
-        pick(&mut s, "Chain Bottom", 0, "No Track Matte").unwrap();
-        assert!(find(&s, "Chain Bottom").track_matte.is_none());
-        assert!(track_matte_pick(&bottom, &candidates, 1, "-").is_none(), "a separator does nothing");
-    }
-
-    /// #957: vector footage gets the Continuously Rasterize switch; raster footage does not.
-    #[test]
-    fn collapse_switch_shows_for_vector_footage_only() {
-        use effectcraft_engine::color::Label;
-        use effectcraft_engine::project::{Footage, ItemKind, Project};
-        let mut p = Project::default();
-        let mut layer_for = |name: &str, codec: &str| {
-            let footage = Footage { path: name.into(), codec: codec.into(), ..Default::default() };
-            let item = p.add_item(name, Label::SeaFoam, None, ItemKind::Footage(footage));
-            let comp = Comp::new(64, 36, effectcraft_engine::time::FrameRate::new(30, 1), Tick::from_seconds_f64(1.0));
-            effectcraft_engine::project::build::layer(&mut p, &comp, name, LayerSource::Footage { item }, (0, 0), None)
-        };
-        let svg = layer_for("logo.svg", "SVG");
-        let png = layer_for("photo.png", "PNG");
-        assert!(collapse_applies(&svg, &p));
-        assert!(!collapse_applies(&png, &p));
-    }
-
-    /// A comp with two solids; "Box" has an animated Position and a Gaussian Blur.
-    fn app() -> EffectcraftApp {
-        let mut s = effectcraft_engine::Session::default();
-        s.execute("comp.new", json!({"name": "T", "width": 320, "height": 180, "duration": 4})).unwrap();
-        s.execute("layer.newSolid", json!({"name": "Plate", "color": "#406080", "width": 320, "height": 180})).unwrap();
-        s.execute("layer.newSolid", json!({"name": "Box", "color": "#e04020", "width": 40, "height": 40})).unwrap();
-        let comp = s.active_comp().unwrap();
-        let bx = comp.layers.iter().find(|l| l.name == "Box").unwrap().id.0;
-        s.execute("layer.select", json!({"layers": [bx]})).unwrap();
-        s.execute("effect.apply", json!({"effect": "ec.blur.gaussian"})).unwrap();
-        let pos = s.active_comp().unwrap().layer(LayerId(bx)).unwrap().transform().unwrap().get("position").unwrap().uid;
-        s.execute("prop.toggleAnimation", json!({"layer": bx, "prop": pos})).unwrap();
-        EffectcraftApp::new(s)
-    }
-
-    fn labels(app: &EffectcraftApp) -> Vec<String> {
-        let comp = app.session.active_comp().unwrap().clone();
-        build_rows(app, &comp)
-            .into_iter()
-            .map(|r| {
-                let l = comp.layer(r.layer).unwrap();
-                match r.kind {
-                    RowKind::Layer => l.name.clone(),
-                    RowKind::Group { name, .. } => format!("{}>{name}", "  ".repeat(r.depth)),
-                    RowKind::Prop { uid } => format!("{}{}", "  ".repeat(r.depth), l.props.find(uid).unwrap().name),
-                    _ => "?".into(),
-                }
-            })
-            .collect()
-    }
-
-    #[test]
-    fn search_filters_layers_and_reveals_matching_properties() {
-        let mut app = app();
-        app.ui.timeline.search = "opac".into();
-        let rows = labels(&app);
-        // Both layers have Transform > Opacity; nothing else shows.
-        assert_eq!(rows.iter().filter(|r| r.trim() == "Opacity").count(), 2, "{rows:?}");
-        assert!(rows.iter().any(|r| r.trim() == ">Transform"), "{rows:?}");
-        assert!(!rows.iter().any(|r| r.trim() == "Position"), "{rows:?}");
-        // A layer name match shows the layer alone; a group match brings its contents.
-        app.ui.timeline.search = "plate".into();
-        assert_eq!(labels(&app), vec!["Plate".to_string()]);
-        app.ui.timeline.search = "GAUSSIAN".into();
-        let rows = labels(&app);
-        assert_eq!(rows[0], "Box");
-        assert!(rows.iter().any(|r| r.trim() == ">Effects") && rows.iter().any(|r| r.trim() == "Blurriness"), "{rows:?}");
-        assert!(!rows.contains(&"Plate".to_string()));
-        // Nothing matches → no rows.
-        app.ui.timeline.search = "zzz".into();
-        assert!(labels(&app).is_empty());
-        // Through the command.
-        let ctx = egui::Context::default();
-        crate::menus::invoke(&mut app, &ctx, "timeline.search", json!({"query": "scale"})).unwrap();
-        assert!(labels(&app).iter().any(|r| r.trim() == "Scale"));
-    }
-
-    /// A shape group's inner Contents (AE's elided `ADBE Vectors Group`) draws no row: the
-    /// search shows the full row hierarchy with the group's items — path, fill and Transform —
-    /// listing directly under the group, and the only "Contents" row the layer's own.
-    #[test]
-    fn shape_group_inner_contents_is_elided() {
-        let mut s = effectcraft_engine::Session::default();
-        s.execute("comp.new", json!({"name": "T", "width": 320, "height": 180, "duration": 4})).unwrap();
-        s.execute("layer.newShape", json!({"kind": "rect"})).unwrap();
-        let mut app = EffectcraftApp::new(s);
-        app.ui.timeline.search = "rect".into();
-        assert_eq!(
-            labels(&app),
-            [
-                "Shape Layer 1",
-                "  >Contents",
-                "    >Rectangle 1",
-                "      >Rectangle Path 1",
-                "        Size",
-                "        Position",
-                "        Roundness",
-                "      >Fill 1",
-                "        Composite",
-                "        Fill Rule",
-                "        Color",
-                "        Opacity",
-                "      >Transform",
-                "        Anchor Point",
-                "        Position",
-                "        Scale",
-                "        Skew",
-                "        Skew Axis",
-                "        Rotation",
-                "        Opacity",
-            ]
-            .iter()
-            .map(|r| r.to_string())
-            .collect::<Vec<_>>()
-        );
-    }
-
-    #[test]
-    fn columns_toggle_and_layout() {
-        let mut app = app();
-        let tl = &mut app.ui.timeline;
-        assert!(column_visible(tl, "switches") && !column_visible(tl, "comment") && !column_visible(tl, "modes"));
-        set_column(tl, "comment", true).unwrap();
-        set_column(tl, "stretch", true).unwrap();
-        set_column(tl, "keys", false).unwrap();
-        set_column(tl, "label", false).unwrap();
-        set_column(tl, "modes", true).unwrap();
-        assert!(tl.show_modes && column_visible(tl, "comment") && !column_visible(tl, "label"));
-        assert!(set_column(tl, "name", false).is_err());
-        assert!(set_column(tl, "bogus", true).is_err());
-        let vis = Vis::of(tl);
-        let cw = cols(0.0, 1400.0, vis);
-        // Hidden columns take no room; visible ones are in After Effects' order.
-        assert_eq!(cw.keys, cw.label);
-        assert_eq!(cw.label, cw.num);
-        assert!(cw.name < cw.comment && cw.comment < cw.switches && cw.switches < cw.mode && cw.parent < cw.stretch);
-        assert_eq!(column_at(&cw, cw.comment + 5.0), Some("comment"));
-        assert_eq!(column_at(&cw, cw.name + 5.0), Some("name"));
-        assert_eq!(column_at(&cw, cw.stretch + 5.0), Some("stretch"));
-        // Through the command (as agents do).
-        let ctx = egui::Context::default();
-        let r = crate::menus::invoke(&mut app, &ctx, "timeline.column", json!({"column": "duration"})).unwrap();
-        assert!(r["columns"].as_array().unwrap().iter().any(|c| c == "duration"));
-        crate::menus::invoke(&mut app, &ctx, "timeline.column", json!({"column": "duration", "visible": false})).unwrap();
-        assert!(!column_visible(&app.ui.timeline, "duration"));
-        crate::menus::invoke(&mut app, &ctx, "timeline.sourceName", json!({})).unwrap();
-        assert!(app.ui.timeline.source_name);
-    }
-
-    #[test]
-    fn reveal_keys_add_with_shift_and_uu_reveals_modified() {
-        let mut app = app();
-        let ctx = egui::Context::default();
-        crate::menus::invoke(&mut app, &ctx, "timeline.reveal.opacity", json!({})).unwrap();
-        assert_eq!(app.ui.timeline.reveal, vec!["opacity"]);
-        crate::menus::invoke(&mut app, &ctx, "timeline.revealAdd.scale", json!({})).unwrap();
-        crate::menus::invoke(&mut app, &ctx, "timeline.revealAdd.effects", json!({})).unwrap();
-        assert_eq!(app.ui.timeline.reveal, vec!["opacity", "scale", "effects"]);
-        let rows = labels(&app);
-        assert!(rows.iter().any(|r| r.trim() == "Scale") && rows.iter().any(|r| r.trim() == "Opacity"), "{rows:?}");
-        assert!(rows.iter().any(|r| r.trim() == ">Gaussian Blur"), "{rows:?}");
-        // Tree order: Scale before Opacity.
-        let si = rows.iter().position(|r| r.trim() == "Scale").unwrap();
-        let oi = rows.iter().position(|r| r.trim() == "Opacity").unwrap();
-        assert!(si < oi);
-        // Shift+S again removes Scale.
-        crate::menus::invoke(&mut app, &ctx, "timeline.revealAdd.scale", json!({})).unwrap();
-        assert_eq!(app.ui.timeline.reveal, vec!["opacity", "effects"]);
-        // U: keyframed properties (Position); UU (twice quickly): every modified property.
-        crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
-        let n_keys = app.ui.timeline.reveal_props.len();
-        assert_eq!(app.ui.timeline.reveal, vec!["props"]);
-        assert!(n_keys >= 1);
-        let bx = app.session.state.selected_layers[0].0;
-        app.session.execute("prop.set", json!({"layer": bx, "path": "effects/#1/blurriness", "value": 12})).unwrap();
-        crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
-        assert!(app.ui.timeline.reveal_props.len() > n_keys, "UU reveals modified properties too");
-    }
-
-    #[test]
-    fn scroll_to_time_centres_the_current_time_inside_the_comp() {
-        assert_eq!(centered_on(4.0, 10.0, 5.0), 3.0);
-        // Near the ends the view stops at the comp's start and end.
-        assert_eq!(centered_on(4.0, 10.0, 1.0), 0.0);
-        assert_eq!(centered_on(4.0, 10.0, 9.5), 6.0);
-        // A span longer than the comp, and bad numbers, start at zero.
-        assert_eq!(centered_on(20.0, 10.0, 5.0), 0.0);
-        assert_eq!(centered_on(f64::NAN, 10.0, 5.0), 0.0);
-    }
-
-    /// U and the other reveal shortcuts act on the selected layers only: other layers keep their
-    /// twirl state and their own reveal (#160).
-    #[test]
-    fn reveal_shortcuts_leave_unselected_layers_alone() {
-        let mut app = app();
-        let ctx = egui::Context::default();
-        let comp = app.session.active_comp().unwrap().clone();
-        let id = |n: &str| comp.layers.iter().find(|l| l.name == n).unwrap().id.0;
-        let (plate, bx) = (id("Plate"), id("Box"));
-        let select = |app: &mut EffectcraftApp, l: u64| app.session.execute("layer.select", json!({"layers": [l]})).unwrap();
-        // Plate shows Scale (S); then U on Box.
-        select(&mut app, plate);
-        crate::menus::invoke(&mut app, &ctx, "timeline.reveal.scale", json!({})).unwrap();
-        select(&mut app, bx);
-        crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
-        let tl = &app.ui.timeline;
-        assert!(tl.open_layers.contains(&plate) && tl.open_layers.contains(&bx), "{:?}", tl.open_layers);
-        assert_eq!(tl.layer_reveal.get(&plate), Some(&vec!["scale".to_string()]), "Plate keeps its reveal");
-        assert_eq!(tl.layer_reveal.get(&bx), Some(&vec!["props".to_string()]));
-        let rows = labels(&app);
-        let at = |n: &str| rows.iter().position(|r| r == n).unwrap();
-        assert_eq!(rows[at("Plate") + 1].trim(), "Scale", "{rows:?}");
-        assert_eq!(rows[at("Box") + 1].trim(), "Position", "{rows:?}");
-        // UU (modified): the effect's changed parameter only, under the effect twirled open.
-        // Then U later: Box shows its keyframed properties only again.
-        app.session.execute("prop.set", json!({"layer": bx, "path": "effects/#1/blurriness", "value": 12})).unwrap();
-        crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
-        let rows = labels(&app);
-        let fx = rows.iter().position(|r| r.trim().ends_with("Gaussian Blur")).unwrap_or_else(|| panic!("UU shows the effect: {rows:?}"));
-        assert_eq!(rows[fx + 1].trim(), "Blurriness", "{rows:?}");
-        assert!(!rows.iter().any(|r| r.trim() == "Blur Dimensions"), "unchanged parameters stay hidden: {rows:?}");
-        // Collapsed and expanded by hand, the effect shows all its parameters; UU filters again.
-        let fx_uid = app.session.active_comp().unwrap().layer(LayerId(bx)).unwrap().effects().unwrap().groups().next().unwrap().uid;
-        app.ui.timeline.toggle_group(bx, fx_uid);
-        assert!(!labels(&app).iter().any(|r| r.trim() == "Blurriness"), "collapsed");
-        app.ui.timeline.toggle_group(bx, fx_uid);
-        let rows = labels(&app);
-        assert!(rows.iter().any(|r| r.trim() == "Blurriness") && rows.iter().any(|r| r.trim() == "Blur Dimensions"), "{rows:?}");
-        app.last_reveal = Some(("keyframes".into(), f64::MAX));
-        crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
-        assert!(!labels(&app).iter().any(|r| r.trim() == "Blur Dimensions"), "UU again shows the changed ones only");
-        app.last_reveal = Some(("keyframes".into(), -10.0));
-        crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
-        app.last_reveal = Some(("keyframes".into(), -10.0));
-        crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
-        let rows = labels(&app);
-        assert!(!rows.iter().any(|r| r.trim() == ">Gaussian Blur") && rows.iter().any(|r| r.trim() == "Position"), "{rows:?}");
-        // U again on Box (later than a double press) hides only Box's.
-        app.last_reveal = Some(("keyframes".into(), -10.0));
-        crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
-        let tl = &app.ui.timeline;
-        assert!(!tl.open_layers.contains(&bx) && tl.open_layers.contains(&plate), "{:?}", tl.open_layers);
-        // A layer twirled open by hand shows its whole tree, whatever was revealed elsewhere.
-        app.session.execute("layer.select", json!({"layers": []})).unwrap();
-        app.ui.timeline.open_layers.insert(bx);
-        let rows = labels(&app);
-        assert!(rows.iter().any(|r| r.trim() == ">Transform"), "{rows:?}");
-    }
-
-    /// U and UU show Time Remap on a layer with time remapping enabled.
-    #[test]
-    fn u_and_uu_reveal_time_remap() {
-        let mut s = effectcraft_engine::Session::default();
-        let inner = s.execute("comp.new", json!({"name": "Inner", "width": 32, "height": 32, "duration": 2})).unwrap()["comp"].as_u64().unwrap();
-        s.execute("comp.new", json!({"name": "Main", "width": 64, "height": 64, "duration": 4})).unwrap();
-        let nested = s.execute("layer.addItem", json!({"item": inner})).unwrap()["layer"].as_u64().unwrap();
-        let mut app = EffectcraftApp::new(s);
-        let ctx = egui::Context::default();
-        crate::menus::invoke(&mut app, &ctx, "layer.enableTimeRemap", json!({"layers": [nested]})).unwrap();
-        app.session.execute("layer.select", json!({"layers": [nested]})).unwrap();
-        for uu in [false, true] {
-            app.ui.timeline.layer_reveal.clear();
-            app.last_reveal = uu.then(|| ("keyframes".into(), f64::MAX));
-            crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
-            assert_eq!(app.ui.timeline.layer_reveal.get(&nested), Some(&vec!["props".to_string()]), "UU: {uu}");
-            let rows = labels(&app);
-            let at = rows.iter().position(|r| r == "Inner").unwrap();
-            assert_eq!(rows[at + 1].trim(), "Time Remap", "UU: {uu}: {rows:?}");
-        }
-    }
-
-    /// U shows Time Remap while remapping is enabled even after its keys are deleted (#990):
-    /// enabling remapping is itself the modification.
-    #[test]
-    fn u_reveals_keyless_time_remap() {
-        let mut s = effectcraft_engine::Session::default();
-        let inner = s.execute("comp.new", json!({"name": "Inner", "width": 32, "height": 32, "duration": 2})).unwrap()["comp"].as_u64().unwrap();
-        s.execute("comp.new", json!({"name": "Main", "width": 64, "height": 64, "duration": 4})).unwrap();
-        let nested = s.execute("layer.addItem", json!({"item": inner})).unwrap()["layer"].as_u64().unwrap();
-        let mut app = EffectcraftApp::new(s);
-        let ctx = egui::Context::default();
-        crate::menus::invoke(&mut app, &ctx, "layer.enableTimeRemap", json!({"layers": [nested]})).unwrap();
-        let uid = app.session.active_comp().unwrap().layer(LayerId(nested)).unwrap().props.prop("timeRemap").unwrap().uid;
-        for _ in 0..2 {
-            let t = app.session.active_comp().unwrap().layer(LayerId(nested)).unwrap().props.prop("timeRemap").unwrap().keys[0].time.seconds();
-            app.session.execute("keys.select", json!({"keys": [{"layer": nested, "prop": uid, "time": t}]})).unwrap();
-            app.session.execute("edit.clear", json!({})).unwrap();
-        }
-        assert!(app.session.active_comp().unwrap().layer(LayerId(nested)).unwrap().props.prop("timeRemap").unwrap().keys.is_empty());
-        app.session.execute("layer.select", json!({"layers": [nested]})).unwrap();
-        crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
-        assert_eq!(app.ui.timeline.layer_reveal.get(&nested), Some(&vec!["props".to_string()]));
-        let rows = labels(&app);
-        let at = rows.iter().position(|r| r == "Inner").unwrap();
-        assert_eq!(rows[at + 1].trim(), "Time Remap", "{rows:?}");
-    }
-
-    /// Enabling time remapping twirls the layer open on Time Remap (#157); disabling it reveals
-    /// nothing.
-    #[test]
-    fn enabling_time_remapping_reveals_time_remap() {
-        let mut s = effectcraft_engine::Session::default();
-        let inner = s.execute("comp.new", json!({"name": "Inner", "width": 32, "height": 32, "duration": 2})).unwrap()["comp"].as_u64().unwrap();
-        s.execute("comp.new", json!({"name": "Main", "width": 64, "height": 64, "duration": 4})).unwrap();
-        s.execute("layer.newSolid", json!({"name": "Other"})).unwrap();
-        let nested = s.execute("layer.addItem", json!({"item": inner})).unwrap()["layer"].as_u64().unwrap();
-        let mut app = EffectcraftApp::new(s);
-        let ctx = egui::Context::default();
-        crate::menus::invoke(&mut app, &ctx, "layer.enableTimeRemap", json!({"layers": [nested]})).unwrap();
-        assert_eq!(app.ui.timeline.layer_reveal.get(&nested), Some(&vec!["timeRemap".to_string()]));
-        let rows = labels(&app);
-        let at = rows.iter().position(|r| r == "Inner").unwrap();
-        assert_eq!(rows[at + 1].trim(), "Time Remap", "{rows:?}");
-        // Through the selection (the Layer menu), turning it off again: nothing new is revealed.
-        app.session.execute("layer.select", json!({"layers": [nested]})).unwrap();
-        app.ui.timeline.layer_reveal.clear();
-        crate::menus::invoke(&mut app, &ctx, "layer.enableTimeRemap", json!({})).unwrap();
-        assert!(app.ui.timeline.layer_reveal.is_empty());
-    }
-
-    #[test]
-    fn cti_snaps_to_the_nearest_candidate() {
-        assert_eq!(snap_time(&[0.0, 1.0, 2.0], 1.04, 0.1), 1.0);
-        assert_eq!(snap_time(&[0.0, 1.0, 2.0], 1.5, 0.1), 1.5);
-        assert_eq!(snap_time(&[1.0, 1.1], 1.06, 0.1), 1.1);
-        let app = app();
-        let comp = app.session.active_comp().unwrap().clone();
-        let c = snap_candidates(&comp, &build_rows(&app, &comp));
-        assert!(c.contains(&comp.duration.seconds()) && c.contains(&0.0));
-    }
-
-    /// Every string drawn by one frame of `draw`.
-    fn drawn_text(mut draw: impl FnMut(&mut egui::Ui)) -> Vec<String> {
-        fn collect(shape: &egui::Shape, out: &mut Vec<String>) {
-            match shape {
-                egui::Shape::Text(t) => out.push(t.galley.text().to_string()),
-                egui::Shape::Vec(v) => v.iter().for_each(|s| collect(s, out)),
-                _ => {}
-            }
-        }
-        let ctx = egui::Context::default();
-        ctx.run_ui(Default::default(), |ui| draw(ui)).textures_delta.clear();
-        let mut frame = ctx.run_ui(Default::default(), |ui| draw(ui));
-        frame.textures_delta.clear();
-        let mut out = Vec::new();
-        frame.shapes.iter().for_each(|c| collect(&c.shape, &mut out));
-        out
-    }
-
-    /// #1308: the layer context menu draws its items in the interface language, from the menu
-    /// bar's rows for the same commands (whose ellipsis is `...`), and its Effects submenu draws
-    /// the categories the Effect menu does; the actions it records stay the same.
-    #[test]
-    fn the_layer_context_menu_draws_in_the_interface_language() {
-        let caps = LayerMenuCaps { vector: true, text: false, source: true };
-        let (mut auto, mut actions) = (crate::automation::Registry::default(), Vec::new());
-        crate::i18n::set_current("zh-hans");
-        let menu = drawn_text(|ui| layer_menu(ui, &[7], caps, (&mut auto, "t"), &mut actions));
-        let effects = drawn_text(|ui| effects_submenu(ui, &[7], &mut |_: &mut egui::Ui, _: &str, _: &str, _: serde_json::Value| {}));
-        crate::i18n::set_current("en");
-        let english = drawn_text(|ui| layer_menu(ui, &[7], caps, (&mut auto, "t"), &mut actions));
-        for label in ["新建", "图层设置...", "在项目中显示图层源", "从矢量图层创建形状", "预合成...", "重复", "拆分图层", "删除"]
-        {
-            assert!(menu.iter().any(|t| t == label), "{label} missing from {menu:?}");
-        }
-        assert!(!menu.iter().any(|t| t.is_ascii()), "English left in {menu:?}");
-        assert!(effects.iter().any(|t| t == "模糊和锐化"), "{effects:?}");
-        assert!(!effects.iter().any(|t| t == "Blur & Sharpen"), "{effects:?}");
-        for label in ["Layer Settings…", "Reveal Layer Source in Project", "Duplicate", "Delete"] {
-            assert!(english.iter().any(|t| t == label), "{label} missing from {english:?}");
-        }
-        assert!(actions.is_empty());
-    }
-
-    /// The property context menu draws its items in the interface language too: the commands the
-    /// menu bar has from its rows, Reset, Edit Value… and Remove Expression from the panel catalog.
-    /// The automation labels stay English.
-    #[test]
-    fn the_property_context_menu_draws_in_the_interface_language() {
-        let mut s = effectcraft_engine::Session::default();
-        s.execute("comp.new", json!({"name": "Main", "width": 64, "height": 64, "duration": 4})).unwrap();
-        let l = s.execute("layer.newSolid", json!({"name": "Plate", "color": "#406080"})).unwrap()["layer"].as_u64().unwrap();
-        let opacity = s.active_comp().unwrap().layer(LayerId(l)).unwrap().props.prop("transform/opacity").unwrap().uid;
-        s.execute("prop.setExpression", json!({"layer": l, "prop": opacity})).unwrap();
-        let comp = s.active_comp_id().unwrap();
-        let layer = s.active_comp().unwrap().layer(LayerId(l)).unwrap().clone();
-        let (position, opacity) = (layer.props.prop("transform/position").unwrap(), layer.props.prop("transform/opacity").unwrap());
-        let (mut auto, mut actions) = (crate::automation::Registry::default(), Vec::new());
-        let mut menu = |language| {
-            crate::i18n::set_current(language);
-            let mut drawn = drawn_text(|ui| prop_menu(ui, &mut auto, comp, &layer, position, &mut actions));
-            drawn.extend(drawn_text(|ui| prop_menu(ui, &mut auto, comp, &layer, opacity, &mut actions)));
-            drawn
-        };
-        let chinese = menu("zh-hans");
-        let english = menu("en");
-        for label in ["重置", "编辑值…", "单独尺寸", "添加表达式", "移除表达式", "向基本图形添加属性"] {
-            assert!(chinese.iter().any(|t| t == label), "{label} missing from {chinese:?}");
-        }
-        assert!(!chinese.iter().any(|t| t.is_ascii()), "English left in {chinese:?}");
-        for label in ["Reset", "Edit Value…", "Separate Dimensions", "Remove Expression", "Add Property to Essential Graphics"] {
-            assert!(english.iter().any(|t| t == label), "{label} missing from {english:?}");
-        }
-        assert!(auto.elements.iter().any(|e| e.label == "Remove Expression"), "the automation label stays English");
-        assert!(actions.is_empty());
-    }
-
-    /// UI fidelity (M13.5): compact After Effects-like rows and muted label-coloured bars.
-    #[test]
-    fn rows_and_bars_follow_after_effects_proportions() {
-        let t = crate::theme::Tokens::for_kind(crate::theme::ThemeKind::Dark);
-        assert_eq!(t.row_h, 19.0);
-        let red = t.label(effectcraft_engine::color::Label::Red);
-        let bar = bar_color(red, false);
-        // Muted: darker and less saturated than the label, still reddish.
-        assert!(bar.r() < red.r() && bar.r() > bar.g() + 30 && bar.g() >= red.g().min(0x3a) - 1);
-        let sel = bar_color(red, true);
-        assert!(sel.r() > bar.r());
-    }
-
-    #[test]
-    fn disk_bar_range_covers_partial_frames() {
-        let clip = Rect::from_min_max(pos2(0.0, 0.0), pos2(2.0, 1.0));
-        let tm = TMap { x0: 0.0, start: 10.25, pps: 1.0 };
-        assert_eq!(disk_bar_range(&tm, clip, 1.0, 100), 10..13);
-
-        let exact = TMap { start: 10.0, ..tm };
-        assert_eq!(disk_bar_range(&exact, clip, 1.0, 100), 10..12);
-        let off_comp = TMap { start: 200.0, ..tm };
-        assert_eq!(disk_bar_range(&off_comp, clip, 1.0, 100), 100..100);
-        assert_eq!(disk_bar_range(&tm, clip, f64::NAN, 100), 0..0);
-        assert_eq!(disk_bar_range(&TMap { pps: 0.0, ..tm }, clip, 1.0, 100), 0..0);
-        assert_eq!(disk_bar_range(&TMap { start: f64::NAN, ..tm }, clip, 1.0, 100), 0..0);
-        assert_eq!(disk_bar_range(&tm, Rect::from_min_max(pos2(2.0, 0.0), pos2(2.0, 1.0)), 1.0, 100), 0..0);
-        let above_limit = TMap { start: 100_001.0, ..tm };
-        assert_eq!(disk_bar_range(&above_limit, clip, 1.0, i64::MAX), 100_000..100_000);
+    app.auto.add(&format!("timeline.prop.{uid}.eyedropper"), er, &prop.name);
+    let mut rgb = [c[0] as f32, c[1] as f32, c[2] as f32];
+    if crate::widgets::color_popup(ui, pop, r.left_bottom(), &mut rgb) {
+        ve.set(actions, json!([rgb[0], rgb[1], rgb[2], 1.0]));
     }
 }
+
+/// A checkbox.
+fn bool_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, ve: &ValueEdit<'_>, actions: &mut Vec<(String, serde_json::Value)>, value: &Value) {
+    let Value::Bool(b) = value else { return };
+    let (prop, at, uid) = (ve.prop, ve.at, ve.uid);
+    let t = app.tokens;
+    let x = at.x;
+    let r = Rect::from_min_size(pos2(x, at.y - 8.0), vec2(16.0, 16.0));
+    if widgets::checkbox(ui, r, *b, &t, egui::Id::unique(("cb", uid))).clicked() {
+        ve.set(actions, json!(!b));
+    }
+    app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
+}
+
+/// A popup (or the number when the property has no options).
+fn enum_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, ve: &ValueEdit<'_>, actions: &mut Vec<(String, serde_json::Value)>, value: &Value) {
+    let Value::Enum(i) = value else { return };
+    let (p, layer, prop, at, uid) = (ve.p, ve.layer, ve.prop, ve.at, ve.uid);
+    let t = app.tokens;
+    let x = at.x;
+    // Text Path Options ▸ Path lists the layer's masks.
+    let mask_opts: Option<Vec<String>> = layer
+        .props
+        .prop("text/pathOptions/path")
+        .filter(|q| q.uid == uid)
+        .map(|_| std::iter::once("None".to_string()).chain(layer.masks().into_iter().flat_map(|m| m.groups().map(|g| g.name.clone()))).collect());
+    let ui_opts = mask_opts.map(|options| ParamUi::Popup { options });
+    if let ParamUi::Popup { options } = ui_opts.as_ref().unwrap_or(&prop.ui) {
+        let r = Rect::from_min_size(pos2(x, at.y - 9.0), vec2(150.0, 18.0));
+        let label = options.get(*i as usize).cloned().unwrap_or_default();
+        let pop = egui::Id::unique(("epop", uid));
+        if widgets::dropdown(ui, r, &label, &t, egui::Id::unique(("en", uid))).clicked() {
+            widgets::open_popup(ui, pop);
+        }
+        app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
+        if let Some(ni) = widgets::popup_menu(ui, pop, r.left_bottom(), options, Some(*i as usize)) {
+            ve.set(actions, json!(ni));
+        }
+    } else {
+        p.text(pos2(x, at.y), Align2::LEFT_CENTER, fmt_num(*i as f64, 0), Tokens::ui(12.0), t.hot_text);
+    }
+}
+
+/// A layer reference picker.
+fn layer_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, ve: &ValueEdit<'_>, actions: &mut Vec<(String, serde_json::Value)>, value: &Value) {
+    let Value::Layer(l) = value else { return };
+    let (prop, at, uid) = (ve.prop, ve.at, ve.uid);
+    let t = app.tokens;
+    let x = at.x;
+    // Layer references (a light's Source, a Displacement Map's layer…) pick from the
+    // comp's layers, as in Effect Controls; the choice is written through the same
+    // undoable prop.set as the other value arms.
+    let r = Rect::from_min_size(pos2(x, at.y - 9.0), vec2(150.0, 18.0));
+    if let Some(comp) = app.session.active_comp_arc()
+        && let Some(chosen) = widgets::layer_picker(ui, r, &comp.layers, *l, &t, egui::Id::unique(("tl-lay", uid)))
+    {
+        ve.set(actions, chosen.map(|id| json!(id)).unwrap_or(serde_json::Value::Null));
+    }
+    app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
+}
+
+/// Opens the Gradient Editor at the current time (#612).
+fn gradient_editor(app: &mut EffectcraftApp, ui: &mut egui::Ui, ve: &ValueEdit<'_>, actions: &mut Vec<(String, serde_json::Value)>) {
+    let (p, layer, prop, at, uid) = (ve.p, ve.layer, ve.prop, ve.at, ve.uid);
+    let t = app.tokens;
+    let x = at.x;
+    // Opens the Gradient Editor at the current time (#612).
+    let r = p.text(pos2(x, at.y), Align2::LEFT_CENTER, crate::i18n::tr("Edit Gradient…"), Tokens::ui(12.0), t.hot_text);
+    let resp = ui.interact(r.expand(2.0), egui::Id::unique(("gradient-edit", uid)), Sense::click());
+    if resp.hovered() {
+        ui.ctx().set_cursor_icon(egui::CursorIcon::PointingHand);
+    }
+    app.auto.add(&format!("timeline.prop.{uid}.value"), r, &prop.name);
+    if resp.clicked() {
+        actions.push(("prop.editGradient".into(), json!({"layer": layer.id.0, "prop": uid})));
+    }
+}
+
+#[cfg(test)]
+mod tests;
diff --git a/crates/ui-egui/src/panels/timeline/tests.rs b/crates/ui-egui/src/panels/timeline/tests.rs
new file mode 100644
index 000000000..0355ea5ed
--- /dev/null
+++ b/crates/ui-egui/src/panels/timeline/tests.rs
@@ -0,0 +1,537 @@
+use super::*;
+
+/// Alt/Option-drag takes the same Project items `layer.replaceSource` does: compositions,
+/// footage and solids, never folders, data files or 3D models.
+#[test]
+fn replace_source_takes_visual_items_only() {
+    use effectcraft_engine::color::Label;
+    use effectcraft_engine::project::{Comp, Footage, Project, Solid};
+    use effectcraft_engine::time::{FrameRate, Tick};
+    let mut p = Project::default();
+    let l = Label::None;
+    let comp = p.add_item("C", l, None, ItemKind::Comp(Comp::new(10, 10, FrameRate::FPS_30, Tick::from_seconds_f64(1.0)).into()));
+    let folder = p.add_item("F", l, None, ItemKind::Folder);
+    let still = p.add_item("S", l, None, ItemKind::Footage(Footage { kind: FootageKind::Still, ..Default::default() }));
+    let data = p.add_item("D", l, None, ItemKind::Footage(Footage { kind: FootageKind::Data, ..Default::default() }));
+    let model = p.add_item("M", l, None, ItemKind::Footage(Footage { kind: FootageKind::Model, ..Default::default() }));
+    let solid = p.add_item("So", l, None, ItemKind::Solid(Solid { color: [0.0; 3], width: 10, height: 10, pixel_aspect: 1.0 }));
+    for (id, ok) in [(comp, true), (still, true), (solid, true), (folder, false), (data, false), (model, false)] {
+        assert_eq!(replaceable_item(p.item(id).unwrap()), ok, "{id:?}");
+    }
+}
+
+/// Alt/Cmd-click twirls Audio's Waveform row (not in the property tree) with the rest.
+#[test]
+fn the_waveform_row_twirls_with_its_tree() {
+    let mut root = PropGroup::new(1, "", "");
+    let mut audio = PropGroup::new(2, "audio", "Audio");
+    audio.children.push(PropGroup::new(3, "x", "X").into());
+    root.children.push(audio.into());
+    let mut uids = vec![];
+    walk_groups(&root, &mut uids);
+    assert_eq!(uids, vec![2, WAVE_BIT | 2, 3]);
+    let mut uids = vec![];
+    walk_groups(find_group(&root, 2).unwrap(), &mut uids);
+    assert_eq!(uids, vec![WAVE_BIT | 2, 3]);
+}
+
+/// #710: with Time Display set to Frames the ruler labels are frame numbers (as under the
+/// CTI, from Start Numbering Frames At); otherwise seconds:frames.
+#[test]
+fn ruler_labels_follow_the_time_display_style() {
+    use effectcraft_engine::project::{ProjectSettings, TimeDisplayStyle};
+    let mut st = ProjectSettings { time_display: TimeDisplayStyle::Timecode, frame_start: 0, ..ProjectSettings::default() };
+    assert_eq!(ruler_label(15, 30, &st), "00:15f");
+    assert_eq!(ruler_label(45, 30, &st), "01:15f");
+    assert_eq!(ruler_label(30 * 3600 + 31, 30, &st), "60:01:01f");
+    st.time_display = TimeDisplayStyle::Frames;
+    assert_eq!(ruler_label(0, 30, &st), "00000");
+    assert_eq!(ruler_label(45, 30, &st), "00045");
+    st.frame_start = 1;
+    assert_eq!(ruler_label(45, 30, &st), "00046");
+    assert_eq!(ruler_label(i64::MAX, 30, &st), format!("{:05}", i64::MAX));
+}
+
+/// #468: playback pages the view to the CTI; a scrub past either end scrolls that way.
+#[test]
+fn the_view_pages_to_the_cti() {
+    assert_eq!(page_to_cti(10.0, 5.0, 60.0, 12.0), 10.0, "in view: unchanged");
+    assert_eq!(page_to_cti(10.0, 5.0, 60.0, 16.0), 16.0, "past the right end: the page from the CTI");
+    assert_eq!(page_to_cti(10.0, 5.0, 60.0, 3.0), 3.0, "before the start");
+    assert_eq!(page_to_cti(10.0, 5.0, 60.0, 58.0), 55.0, "not past the comp's end");
+    assert_eq!(page_to_cti(10.0, 80.0, 60.0, 95.0), 0.0);
+    assert_eq!(page_to_cti(10.0, f64::NAN, 60.0, 95.0), 10.0);
+    assert_eq!(edge_scroll_speed_x(100.0, 500.0, 300.0), 0.0);
+    assert!(edge_scroll_speed_x(100.0, 500.0, 501.0) > 0.0 && edge_scroll_speed_x(100.0, 500.0, 99.0) < 0.0);
+    assert!(edge_scroll_speed_x(100.0, 500.0, 600.0) > edge_scroll_speed_x(100.0, 500.0, 520.0));
+}
+
+/// #864: picking only a mode in a layer's Track Matte menu sets a matte (the layer above);
+/// it used to close the menu and change nothing.
+#[test]
+fn a_track_matte_mode_without_a_matte_takes_the_layer_above() {
+    let mut s = effectcraft_engine::Session::default();
+    s.execute("comp.new", json!({"name": "T", "width": 64, "height": 64, "duration": 1})).unwrap();
+    for name in ["Chain Bottom", "Matte", "Chain Top"] {
+        s.execute("layer.newSolid", json!({"name": name, "color": "#ffffff", "width": 64, "height": 64})).unwrap();
+    }
+    let find = |s: &effectcraft_engine::Session, n: &str| s.active_comp().unwrap().layers.iter().find(|l| l.name == n).unwrap().clone();
+    let (bottom, matte, top) = (find(&s, "Chain Bottom"), find(&s, "Matte"), find(&s, "Chain Top"));
+    let candidates = [top.id, matte.id];
+    let pick = |s: &mut effectcraft_engine::Session, name: &str, i: usize, choice: &str| {
+        let (id, params) = track_matte_pick(&find(s, name), &candidates, i, choice).expect("a menu item is an action");
+        s.execute(&id, params)
+    };
+    pick(&mut s, "Chain Bottom", 5, "Alpha Inverted Matte").unwrap();
+    let m = find(&s, "Chain Bottom").track_matte.expect("a matte");
+    assert_eq!((m.layer, m.kind), (matte.id, MatteKind::AlphaInverted));
+    assert!(!find(&s, "Matte").switches.video, "the matte layer is hidden");
+    // A mode change keeps the matte layer; a matte change keeps the mode.
+    pick(&mut s, "Chain Bottom", 6, "Luma Matte").unwrap();
+    assert_eq!(find(&s, "Chain Bottom").track_matte.map(|m| (m.layer, m.kind)), Some((matte.id, MatteKind::Luma)));
+    pick(&mut s, "Chain Bottom", 2, "1. Chain Top").unwrap();
+    assert_eq!(find(&s, "Chain Bottom").track_matte.map(|m| (m.layer, m.kind)), Some((top.id, MatteKind::Luma)));
+    assert!(s.undo());
+    assert_eq!(find(&s, "Chain Bottom").track_matte.map(|m| m.layer), Some(matte.id), "one undo step per pick");
+    // The top layer has nothing above it: an error for the status bar, not a silent no-op.
+    assert!(pick(&mut s, "Chain Top", 5, "Alpha Matte").is_err());
+    pick(&mut s, "Chain Bottom", 0, "No Track Matte").unwrap();
+    assert!(find(&s, "Chain Bottom").track_matte.is_none());
+    assert!(track_matte_pick(&bottom, &candidates, 1, "-").is_none(), "a separator does nothing");
+}
+
+/// #957: vector footage gets the Continuously Rasterize switch; raster footage does not.
+#[test]
+fn collapse_switch_shows_for_vector_footage_only() {
+    use effectcraft_engine::color::Label;
+    use effectcraft_engine::project::{Footage, ItemKind, Project};
+    let mut p = Project::default();
+    let mut layer_for = |name: &str, codec: &str| {
+        let footage = Footage { path: name.into(), codec: codec.into(), ..Default::default() };
+        let item = p.add_item(name, Label::SeaFoam, None, ItemKind::Footage(footage));
+        let comp = Comp::new(64, 36, effectcraft_engine::time::FrameRate::new(30, 1), Tick::from_seconds_f64(1.0));
+        effectcraft_engine::project::build::layer(&mut p, &comp, name, LayerSource::Footage { item }, (0, 0), None)
+    };
+    let svg = layer_for("logo.svg", "SVG");
+    let png = layer_for("photo.png", "PNG");
+    assert!(collapse_applies(&svg, &p));
+    assert!(!collapse_applies(&png, &p));
+}
+
+/// A comp with two solids; "Box" has an animated Position and a Gaussian Blur.
+fn app() -> EffectcraftApp {
+    let mut s = effectcraft_engine::Session::default();
+    s.execute("comp.new", json!({"name": "T", "width": 320, "height": 180, "duration": 4})).unwrap();
+    s.execute("layer.newSolid", json!({"name": "Plate", "color": "#406080", "width": 320, "height": 180})).unwrap();
+    s.execute("layer.newSolid", json!({"name": "Box", "color": "#e04020", "width": 40, "height": 40})).unwrap();
+    let comp = s.active_comp().unwrap();
+    let bx = comp.layers.iter().find(|l| l.name == "Box").unwrap().id.0;
+    s.execute("layer.select", json!({"layers": [bx]})).unwrap();
+    s.execute("effect.apply", json!({"effect": "ec.blur.gaussian"})).unwrap();
+    let pos = s.active_comp().unwrap().layer(LayerId(bx)).unwrap().transform().unwrap().get("position").unwrap().uid;
+    s.execute("prop.toggleAnimation", json!({"layer": bx, "prop": pos})).unwrap();
+    EffectcraftApp::new(s)
+}
+
+fn labels(app: &EffectcraftApp) -> Vec<String> {
+    let comp = app.session.active_comp().unwrap().clone();
+    build_rows(app, &comp)
+        .into_iter()
+        .map(|r| {
+            let l = comp.layer(r.layer).unwrap();
+            match r.kind {
+                RowKind::Layer => l.name.clone(),
+                RowKind::Group { name, .. } => format!("{}>{name}", "  ".repeat(r.depth)),
+                RowKind::Prop { uid } => format!("{}{}", "  ".repeat(r.depth), l.props.find(uid).unwrap().name),
+                _ => "?".into(),
+            }
+        })
+        .collect()
+}
+
+#[test]
+fn search_filters_layers_and_reveals_matching_properties() {
+    let mut app = app();
+    app.ui.timeline.search = "opac".into();
+    let rows = labels(&app);
+    // Both layers have Transform > Opacity; nothing else shows.
+    assert_eq!(rows.iter().filter(|r| r.trim() == "Opacity").count(), 2, "{rows:?}");
+    assert!(rows.iter().any(|r| r.trim() == ">Transform"), "{rows:?}");
+    assert!(!rows.iter().any(|r| r.trim() == "Position"), "{rows:?}");
+    // A layer name match shows the layer alone; a group match brings its contents.
+    app.ui.timeline.search = "plate".into();
+    assert_eq!(labels(&app), vec!["Plate".to_string()]);
+    app.ui.timeline.search = "GAUSSIAN".into();
+    let rows = labels(&app);
+    assert_eq!(rows[0], "Box");
+    assert!(rows.iter().any(|r| r.trim() == ">Effects") && rows.iter().any(|r| r.trim() == "Blurriness"), "{rows:?}");
+    assert!(!rows.contains(&"Plate".to_string()));
+    // Nothing matches → no rows.
+    app.ui.timeline.search = "zzz".into();
+    assert!(labels(&app).is_empty());
+    // Through the command.
+    let ctx = egui::Context::default();
+    crate::menus::invoke(&mut app, &ctx, "timeline.search", json!({"query": "scale"})).unwrap();
+    assert!(labels(&app).iter().any(|r| r.trim() == "Scale"));
+}
+
+/// A shape group's inner Contents (AE's elided `ADBE Vectors Group`) draws no row: the
+/// search shows the full row hierarchy with the group's items — path, fill and Transform —
+/// listing directly under the group, and the only "Contents" row the layer's own.
+#[test]
+fn shape_group_inner_contents_is_elided() {
+    let mut s = effectcraft_engine::Session::default();
+    s.execute("comp.new", json!({"name": "T", "width": 320, "height": 180, "duration": 4})).unwrap();
+    s.execute("layer.newShape", json!({"kind": "rect"})).unwrap();
+    let mut app = EffectcraftApp::new(s);
+    app.ui.timeline.search = "rect".into();
+    assert_eq!(
+        labels(&app),
+        [
+            "Shape Layer 1",
+            "  >Contents",
+            "    >Rectangle 1",
+            "      >Rectangle Path 1",
+            "        Size",
+            "        Position",
+            "        Roundness",
+            "      >Fill 1",
+            "        Composite",
+            "        Fill Rule",
+            "        Color",
+            "        Opacity",
+            "      >Transform",
+            "        Anchor Point",
+            "        Position",
+            "        Scale",
+            "        Skew",
+            "        Skew Axis",
+            "        Rotation",
+            "        Opacity",
+        ]
+        .iter()
+        .map(|r| r.to_string())
+        .collect::<Vec<_>>()
+    );
+}
+
+#[test]
+fn columns_toggle_and_layout() {
+    let mut app = app();
+    let tl = &mut app.ui.timeline;
+    assert!(column_visible(tl, "switches") && !column_visible(tl, "comment") && !column_visible(tl, "modes"));
+    set_column(tl, "comment", true).unwrap();
+    set_column(tl, "stretch", true).unwrap();
+    set_column(tl, "keys", false).unwrap();
+    set_column(tl, "label", false).unwrap();
+    set_column(tl, "modes", true).unwrap();
+    assert!(tl.show_modes && column_visible(tl, "comment") && !column_visible(tl, "label"));
+    assert!(set_column(tl, "name", false).is_err());
+    assert!(set_column(tl, "bogus", true).is_err());
+    let vis = Vis::of(tl);
+    let cw = cols(0.0, 1400.0, vis);
+    // Hidden columns take no room; visible ones are in After Effects' order.
+    assert_eq!(cw.keys, cw.label);
+    assert_eq!(cw.label, cw.num);
+    assert!(cw.name < cw.comment && cw.comment < cw.switches && cw.switches < cw.mode && cw.parent < cw.stretch);
+    assert_eq!(column_at(&cw, cw.comment + 5.0), Some("comment"));
+    assert_eq!(column_at(&cw, cw.name + 5.0), Some("name"));
+    assert_eq!(column_at(&cw, cw.stretch + 5.0), Some("stretch"));
+    // Through the command (as agents do).
+    let ctx = egui::Context::default();
+    let r = crate::menus::invoke(&mut app, &ctx, "timeline.column", json!({"column": "duration"})).unwrap();
+    assert!(r["columns"].as_array().unwrap().iter().any(|c| c == "duration"));
+    crate::menus::invoke(&mut app, &ctx, "timeline.column", json!({"column": "duration", "visible": false})).unwrap();
+    assert!(!column_visible(&app.ui.timeline, "duration"));
+    crate::menus::invoke(&mut app, &ctx, "timeline.sourceName", json!({})).unwrap();
+    assert!(app.ui.timeline.source_name);
+}
+
+#[test]
+fn reveal_keys_add_with_shift_and_uu_reveals_modified() {
+    let mut app = app();
+    let ctx = egui::Context::default();
+    crate::menus::invoke(&mut app, &ctx, "timeline.reveal.opacity", json!({})).unwrap();
+    assert_eq!(app.ui.timeline.reveal, vec!["opacity"]);
+    crate::menus::invoke(&mut app, &ctx, "timeline.revealAdd.scale", json!({})).unwrap();
+    crate::menus::invoke(&mut app, &ctx, "timeline.revealAdd.effects", json!({})).unwrap();
+    assert_eq!(app.ui.timeline.reveal, vec!["opacity", "scale", "effects"]);
+    let rows = labels(&app);
+    assert!(rows.iter().any(|r| r.trim() == "Scale") && rows.iter().any(|r| r.trim() == "Opacity"), "{rows:?}");
+    assert!(rows.iter().any(|r| r.trim() == ">Gaussian Blur"), "{rows:?}");
+    // Tree order: Scale before Opacity.
+    let si = rows.iter().position(|r| r.trim() == "Scale").unwrap();
+    let oi = rows.iter().position(|r| r.trim() == "Opacity").unwrap();
+    assert!(si < oi);
+    // Shift+S again removes Scale.
+    crate::menus::invoke(&mut app, &ctx, "timeline.revealAdd.scale", json!({})).unwrap();
+    assert_eq!(app.ui.timeline.reveal, vec!["opacity", "effects"]);
+    // U: keyframed properties (Position); UU (twice quickly): every modified property.
+    crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
+    let n_keys = app.ui.timeline.reveal_props.len();
+    assert_eq!(app.ui.timeline.reveal, vec!["props"]);
+    assert!(n_keys >= 1);
+    let bx = app.session.state.selected_layers[0].0;
+    app.session.execute("prop.set", json!({"layer": bx, "path": "effects/#1/blurriness", "value": 12})).unwrap();
+    crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
+    assert!(app.ui.timeline.reveal_props.len() > n_keys, "UU reveals modified properties too");
+}
+
+#[test]
+fn scroll_to_time_centres_the_current_time_inside_the_comp() {
+    assert_eq!(centered_on(4.0, 10.0, 5.0), 3.0);
+    // Near the ends the view stops at the comp's start and end.
+    assert_eq!(centered_on(4.0, 10.0, 1.0), 0.0);
+    assert_eq!(centered_on(4.0, 10.0, 9.5), 6.0);
+    // A span longer than the comp, and bad numbers, start at zero.
+    assert_eq!(centered_on(20.0, 10.0, 5.0), 0.0);
+    assert_eq!(centered_on(f64::NAN, 10.0, 5.0), 0.0);
+}
+
+/// U and the other reveal shortcuts act on the selected layers only: other layers keep their
+/// twirl state and their own reveal (#160).
+#[test]
+fn reveal_shortcuts_leave_unselected_layers_alone() {
+    let mut app = app();
+    let ctx = egui::Context::default();
+    let comp = app.session.active_comp().unwrap().clone();
+    let id = |n: &str| comp.layers.iter().find(|l| l.name == n).unwrap().id.0;
+    let (plate, bx) = (id("Plate"), id("Box"));
+    let select = |app: &mut EffectcraftApp, l: u64| app.session.execute("layer.select", json!({"layers": [l]})).unwrap();
+    // Plate shows Scale (S); then U on Box.
+    select(&mut app, plate);
+    crate::menus::invoke(&mut app, &ctx, "timeline.reveal.scale", json!({})).unwrap();
+    select(&mut app, bx);
+    crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
+    let tl = &app.ui.timeline;
+    assert!(tl.open_layers.contains(&plate) && tl.open_layers.contains(&bx), "{:?}", tl.open_layers);
+    assert_eq!(tl.layer_reveal.get(&plate), Some(&vec!["scale".to_string()]), "Plate keeps its reveal");
+    assert_eq!(tl.layer_reveal.get(&bx), Some(&vec!["props".to_string()]));
+    let rows = labels(&app);
+    let at = |n: &str| rows.iter().position(|r| r == n).unwrap();
+    assert_eq!(rows[at("Plate") + 1].trim(), "Scale", "{rows:?}");
+    assert_eq!(rows[at("Box") + 1].trim(), "Position", "{rows:?}");
+    // UU (modified): the effect's changed parameter only, under the effect twirled open.
+    // Then U later: Box shows its keyframed properties only again.
+    app.session.execute("prop.set", json!({"layer": bx, "path": "effects/#1/blurriness", "value": 12})).unwrap();
+    crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
+    let rows = labels(&app);
+    let fx = rows.iter().position(|r| r.trim().ends_with("Gaussian Blur")).unwrap_or_else(|| panic!("UU shows the effect: {rows:?}"));
+    assert_eq!(rows[fx + 1].trim(), "Blurriness", "{rows:?}");
+    assert!(!rows.iter().any(|r| r.trim() == "Blur Dimensions"), "unchanged parameters stay hidden: {rows:?}");
+    // Collapsed and expanded by hand, the effect shows all its parameters; UU filters again.
+    let fx_uid = app.session.active_comp().unwrap().layer(LayerId(bx)).unwrap().effects().unwrap().groups().next().unwrap().uid;
+    app.ui.timeline.toggle_group(bx, fx_uid);
+    assert!(!labels(&app).iter().any(|r| r.trim() == "Blurriness"), "collapsed");
+    app.ui.timeline.toggle_group(bx, fx_uid);
+    let rows = labels(&app);
+    assert!(rows.iter().any(|r| r.trim() == "Blurriness") && rows.iter().any(|r| r.trim() == "Blur Dimensions"), "{rows:?}");
+    app.last_reveal = Some(("keyframes".into(), f64::MAX));
+    crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
+    assert!(!labels(&app).iter().any(|r| r.trim() == "Blur Dimensions"), "UU again shows the changed ones only");
+    app.last_reveal = Some(("keyframes".into(), -10.0));
+    crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
+    app.last_reveal = Some(("keyframes".into(), -10.0));
+    crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
+    let rows = labels(&app);
+    assert!(!rows.iter().any(|r| r.trim() == ">Gaussian Blur") && rows.iter().any(|r| r.trim() == "Position"), "{rows:?}");
+    // U again on Box (later than a double press) hides only Box's.
+    app.last_reveal = Some(("keyframes".into(), -10.0));
+    crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
+    let tl = &app.ui.timeline;
+    assert!(!tl.open_layers.contains(&bx) && tl.open_layers.contains(&plate), "{:?}", tl.open_layers);
+    // A layer twirled open by hand shows its whole tree, whatever was revealed elsewhere.
+    app.session.execute("layer.select", json!({"layers": []})).unwrap();
+    app.ui.timeline.open_layers.insert(bx);
+    let rows = labels(&app);
+    assert!(rows.iter().any(|r| r.trim() == ">Transform"), "{rows:?}");
+}
+
+/// U and UU show Time Remap on a layer with time remapping enabled.
+#[test]
+fn u_and_uu_reveal_time_remap() {
+    let mut s = effectcraft_engine::Session::default();
+    let inner = s.execute("comp.new", json!({"name": "Inner", "width": 32, "height": 32, "duration": 2})).unwrap()["comp"].as_u64().unwrap();
+    s.execute("comp.new", json!({"name": "Main", "width": 64, "height": 64, "duration": 4})).unwrap();
+    let nested = s.execute("layer.addItem", json!({"item": inner})).unwrap()["layer"].as_u64().unwrap();
+    let mut app = EffectcraftApp::new(s);
+    let ctx = egui::Context::default();
+    crate::menus::invoke(&mut app, &ctx, "layer.enableTimeRemap", json!({"layers": [nested]})).unwrap();
+    app.session.execute("layer.select", json!({"layers": [nested]})).unwrap();
+    for uu in [false, true] {
+        app.ui.timeline.layer_reveal.clear();
+        app.last_reveal = uu.then(|| ("keyframes".into(), f64::MAX));
+        crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
+        assert_eq!(app.ui.timeline.layer_reveal.get(&nested), Some(&vec!["props".to_string()]), "UU: {uu}");
+        let rows = labels(&app);
+        let at = rows.iter().position(|r| r == "Inner").unwrap();
+        assert_eq!(rows[at + 1].trim(), "Time Remap", "UU: {uu}: {rows:?}");
+    }
+}
+
+/// U shows Time Remap while remapping is enabled even after its keys are deleted (#990):
+/// enabling remapping is itself the modification.
+#[test]
+fn u_reveals_keyless_time_remap() {
+    let mut s = effectcraft_engine::Session::default();
+    let inner = s.execute("comp.new", json!({"name": "Inner", "width": 32, "height": 32, "duration": 2})).unwrap()["comp"].as_u64().unwrap();
+    s.execute("comp.new", json!({"name": "Main", "width": 64, "height": 64, "duration": 4})).unwrap();
+    let nested = s.execute("layer.addItem", json!({"item": inner})).unwrap()["layer"].as_u64().unwrap();
+    let mut app = EffectcraftApp::new(s);
+    let ctx = egui::Context::default();
+    crate::menus::invoke(&mut app, &ctx, "layer.enableTimeRemap", json!({"layers": [nested]})).unwrap();
+    let uid = app.session.active_comp().unwrap().layer(LayerId(nested)).unwrap().props.prop("timeRemap").unwrap().uid;
+    for _ in 0..2 {
+        let t = app.session.active_comp().unwrap().layer(LayerId(nested)).unwrap().props.prop("timeRemap").unwrap().keys[0].time.seconds();
+        app.session.execute("keys.select", json!({"keys": [{"layer": nested, "prop": uid, "time": t}]})).unwrap();
+        app.session.execute("edit.clear", json!({})).unwrap();
+    }
+    assert!(app.session.active_comp().unwrap().layer(LayerId(nested)).unwrap().props.prop("timeRemap").unwrap().keys.is_empty());
+    app.session.execute("layer.select", json!({"layers": [nested]})).unwrap();
+    crate::menus::invoke(&mut app, &ctx, "anim.reveal", json!({"kind": "keyframes"})).unwrap();
+    assert_eq!(app.ui.timeline.layer_reveal.get(&nested), Some(&vec!["props".to_string()]));
+    let rows = labels(&app);
+    let at = rows.iter().position(|r| r == "Inner").unwrap();
+    assert_eq!(rows[at + 1].trim(), "Time Remap", "{rows:?}");
+}
+
+/// Enabling time remapping twirls the layer open on Time Remap (#157); disabling it reveals
+/// nothing.
+#[test]
+fn enabling_time_remapping_reveals_time_remap() {
+    let mut s = effectcraft_engine::Session::default();
+    let inner = s.execute("comp.new", json!({"name": "Inner", "width": 32, "height": 32, "duration": 2})).unwrap()["comp"].as_u64().unwrap();
+    s.execute("comp.new", json!({"name": "Main", "width": 64, "height": 64, "duration": 4})).unwrap();
+    s.execute("layer.newSolid", json!({"name": "Other"})).unwrap();
+    let nested = s.execute("layer.addItem", json!({"item": inner})).unwrap()["layer"].as_u64().unwrap();
+    let mut app = EffectcraftApp::new(s);
+    let ctx = egui::Context::default();
+    crate::menus::invoke(&mut app, &ctx, "layer.enableTimeRemap", json!({"layers": [nested]})).unwrap();
+    assert_eq!(app.ui.timeline.layer_reveal.get(&nested), Some(&vec!["timeRemap".to_string()]));
+    let rows = labels(&app);
+    let at = rows.iter().position(|r| r == "Inner").unwrap();
+    assert_eq!(rows[at + 1].trim(), "Time Remap", "{rows:?}");
+    // Through the selection (the Layer menu), turning it off again: nothing new is revealed.
+    app.session.execute("layer.select", json!({"layers": [nested]})).unwrap();
+    app.ui.timeline.layer_reveal.clear();
+    crate::menus::invoke(&mut app, &ctx, "layer.enableTimeRemap", json!({})).unwrap();
+    assert!(app.ui.timeline.layer_reveal.is_empty());
+}
+
+#[test]
+fn cti_snaps_to_the_nearest_candidate() {
+    assert_eq!(snap_time(&[0.0, 1.0, 2.0], 1.04, 0.1), 1.0);
+    assert_eq!(snap_time(&[0.0, 1.0, 2.0], 1.5, 0.1), 1.5);
+    assert_eq!(snap_time(&[1.0, 1.1], 1.06, 0.1), 1.1);
+    let app = app();
+    let comp = app.session.active_comp().unwrap().clone();
+    let c = snap_candidates(&comp, &build_rows(&app, &comp));
+    assert!(c.contains(&comp.duration.seconds()) && c.contains(&0.0));
+}
+
+/// Every string drawn by one frame of `draw`.
+fn drawn_text(mut draw: impl FnMut(&mut egui::Ui)) -> Vec<String> {
+    fn collect(shape: &egui::Shape, out: &mut Vec<String>) {
+        match shape {
+            egui::Shape::Text(t) => out.push(t.galley.text().to_string()),
+            egui::Shape::Vec(v) => v.iter().for_each(|s| collect(s, out)),
+            _ => {}
+        }
+    }
+    let ctx = egui::Context::default();
+    ctx.run_ui(Default::default(), |ui| draw(ui)).textures_delta.clear();
+    let mut frame = ctx.run_ui(Default::default(), |ui| draw(ui));
+    frame.textures_delta.clear();
+    let mut out = Vec::new();
+    frame.shapes.iter().for_each(|c| collect(&c.shape, &mut out));
+    out
+}
+
+/// #1308: the layer context menu draws its items in the interface language, from the menu
+/// bar's rows for the same commands (whose ellipsis is `...`), and its Effects submenu draws
+/// the categories the Effect menu does; the actions it records stay the same.
+#[test]
+fn the_layer_context_menu_draws_in_the_interface_language() {
+    let caps = LayerMenuCaps { vector: true, text: false, source: true };
+    let (mut auto, mut actions) = (crate::automation::Registry::default(), Vec::new());
+    crate::i18n::set_current("zh-hans");
+    let menu = drawn_text(|ui| layer_menu(ui, &[7], caps, (&mut auto, "t"), &mut actions));
+    let effects = drawn_text(|ui| effects_submenu(ui, &[7], &mut |_: &mut egui::Ui, _: &str, _: &str, _: serde_json::Value| {}));
+    crate::i18n::set_current("en");
+    let english = drawn_text(|ui| layer_menu(ui, &[7], caps, (&mut auto, "t"), &mut actions));
+    for label in ["新建", "图层设置...", "在项目中显示图层源", "从矢量图层创建形状", "预合成...", "重复", "拆分图层", "删除"]
+    {
+        assert!(menu.iter().any(|t| t == label), "{label} missing from {menu:?}");
+    }
+    assert!(!menu.iter().any(|t| t.is_ascii()), "English left in {menu:?}");
+    assert!(effects.iter().any(|t| t == "模糊和锐化"), "{effects:?}");
+    assert!(!effects.iter().any(|t| t == "Blur & Sharpen"), "{effects:?}");
+    for label in ["Layer Settings…", "Reveal Layer Source in Project", "Duplicate", "Delete"] {
+        assert!(english.iter().any(|t| t == label), "{label} missing from {english:?}");
+    }
+    assert!(actions.is_empty());
+}
+
+/// The property context menu draws its items in the interface language too: the commands the
+/// menu bar has from its rows, Reset, Edit Value… and Remove Expression from the panel catalog.
+/// The automation labels stay English.
+#[test]
+fn the_property_context_menu_draws_in_the_interface_language() {
+    let mut s = effectcraft_engine::Session::default();
+    s.execute("comp.new", json!({"name": "Main", "width": 64, "height": 64, "duration": 4})).unwrap();
+    let l = s.execute("layer.newSolid", json!({"name": "Plate", "color": "#406080"})).unwrap()["layer"].as_u64().unwrap();
+    let opacity = s.active_comp().unwrap().layer(LayerId(l)).unwrap().props.prop("transform/opacity").unwrap().uid;
+    s.execute("prop.setExpression", json!({"layer": l, "prop": opacity})).unwrap();
+    let comp = s.active_comp_id().unwrap();
+    let layer = s.active_comp().unwrap().layer(LayerId(l)).unwrap().clone();
+    let (position, opacity) = (layer.props.prop("transform/position").unwrap(), layer.props.prop("transform/opacity").unwrap());
+    let (mut auto, mut actions) = (crate::automation::Registry::default(), Vec::new());
+    let mut menu = |language| {
+        crate::i18n::set_current(language);
+        let mut drawn = drawn_text(|ui| prop_menu(ui, &mut auto, comp, &layer, position, &mut actions));
+        drawn.extend(drawn_text(|ui| prop_menu(ui, &mut auto, comp, &layer, opacity, &mut actions)));
+        drawn
+    };
+    let chinese = menu("zh-hans");
+    let english = menu("en");
+    for label in ["重置", "编辑值…", "单独尺寸", "添加表达式", "移除表达式", "向基本图形添加属性"] {
+        assert!(chinese.iter().any(|t| t == label), "{label} missing from {chinese:?}");
+    }
+    assert!(!chinese.iter().any(|t| t.is_ascii()), "English left in {chinese:?}");
+    for label in ["Reset", "Edit Value…", "Separate Dimensions", "Remove Expression", "Add Property to Essential Graphics"] {
+        assert!(english.iter().any(|t| t == label), "{label} missing from {english:?}");
+    }
+    assert!(auto.elements.iter().any(|e| e.label == "Remove Expression"), "the automation label stays English");
+    assert!(actions.is_empty());
+}
+
+/// UI fidelity (M13.5): compact After Effects-like rows and muted label-coloured bars.
+#[test]
+fn rows_and_bars_follow_after_effects_proportions() {
+    let t = crate::theme::Tokens::for_kind(crate::theme::ThemeKind::Dark);
+    assert_eq!(t.row_h, 19.0);
+    let red = t.label(effectcraft_engine::color::Label::Red);
+    let bar = bar_color(red, false);
+    // Muted: darker and less saturated than the label, still reddish.
+    assert!(bar.r() < red.r() && bar.r() > bar.g() + 30 && bar.g() >= red.g().min(0x3a) - 1);
+    let sel = bar_color(red, true);
+    assert!(sel.r() > bar.r());
+}
+
+#[test]
+fn disk_bar_range_covers_partial_frames() {
+    let clip = Rect::from_min_max(pos2(0.0, 0.0), pos2(2.0, 1.0));
+    let tm = TMap { x0: 0.0, start: 10.25, pps: 1.0 };
+    assert_eq!(disk_bar_range(&tm, clip, 1.0, 100), 10..13);
+
+    let exact = TMap { start: 10.0, ..tm };
+    assert_eq!(disk_bar_range(&exact, clip, 1.0, 100), 10..12);
+    let off_comp = TMap { start: 200.0, ..tm };
+    assert_eq!(disk_bar_range(&off_comp, clip, 1.0, 100), 100..100);
+    assert_eq!(disk_bar_range(&tm, clip, f64::NAN, 100), 0..0);
+    assert_eq!(disk_bar_range(&TMap { pps: 0.0, ..tm }, clip, 1.0, 100), 0..0);
+    assert_eq!(disk_bar_range(&TMap { start: f64::NAN, ..tm }, clip, 1.0, 100), 0..0);
+    assert_eq!(disk_bar_range(&tm, Rect::from_min_max(pos2(2.0, 0.0), pos2(2.0, 1.0)), 1.0, 100), 0..0);
+    let above_limit = TMap { start: 100_001.0, ..tm };
+    assert_eq!(disk_bar_range(&above_limit, clip, 1.0, i64::MAX), 100_000..100_000);
+}
diff --git a/crates/ui-egui/src/panels/tracker.rs b/crates/ui-egui/src/panels/tracker.rs
index 513b3ebaa..3edde09df 100644
--- a/crates/ui-egui/src/panels/tracker.rs
+++ b/crates/ui-egui/src/panels/tracker.rs
@@ -115,6 +115,32 @@ fn analyze_glyph(p: &egui::Painter, r: Rect, forward: bool, frame: bool, stop: b
     }
 }
 
+/// The two button rows at `y`: Track Camera / Warp Stabilizer, then Track Motion / Stabilize Motion.
+fn top_buttons(app: &mut EffectcraftApp, ui: &mut egui::Ui, ctx: &egui::Context, x0: f32, y: f32, half: f32, source: Option<LayerId>) {
+    let can_track = app.session.active_comp().is_some() && source.is_some();
+    // Track Camera / Warp Stabilizer and Track Motion / Stabilize Motion.
+    let r1 = Rect::from_min_size(pos2(x0, y), vec2(half, 22.0));
+    let r2 = Rect::from_min_size(pos2(x0 + half + 6.0, y), vec2(half, 22.0));
+    let src_p = source.map(|l| json!({"layer": l.0})).unwrap_or_else(|| json!({}));
+    let can_camera = app.session.is_enabled("track.camera") && !app.session.is_camera_analyzing();
+    if button(app, ui, r1, "Track Camera", can_camera, "tracker.trackCamera") {
+        run(app, ctx, "track.camera", json!({}));
+    }
+    let can_warp = app.session.is_enabled("track.warpStabilizer") && !app.session.is_warp_analyzing();
+    if button(app, ui, r2, "Warp Stabilizer", can_warp, "tracker.warpStabilizer") {
+        run(app, ctx, "track.warpStabilizer", json!({}));
+    }
+    let y = y + 28.0;
+    let r1 = Rect::from_min_size(pos2(x0, y), vec2(half, 22.0));
+    let r2 = Rect::from_min_size(pos2(x0 + half + 6.0, y), vec2(half, 22.0));
+    if button(app, ui, r1, "Track Motion", can_track, "tracker.trackMotion") {
+        run(app, ctx, "track.motion", src_p.clone());
+    }
+    if button(app, ui, r2, "Stabilize Motion", can_track, "tracker.stabilizeMotion") {
+        run(app, ctx, "track.stabilize", src_p.clone());
+    }
+}
+
 /// The Tracker panel: the camera/warp and motion/stabilize buttons, Motion Source and Current
 /// Track pickers, the track type and its channels, Motion Target with Edit Target and Options, the
 /// four Analyze buttons (the one whose direction is running offers Stop), Reset and Apply, and the
@@ -132,33 +158,11 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let w = (rect.width() - 20.0).max(120.0);
     let half = (w - 6.0) / 2.0;
     let mut y = rect.min.y + 10.0;
-    let has_comp = app.session.active_comp().is_some();
     let source = motion_source(app);
     let cur = current(app);
-    let can_track = has_comp && source.is_some();
 
-    // Track Camera / Warp Stabilizer and Track Motion / Stabilize Motion.
-    let r1 = Rect::from_min_size(pos2(x0, y), vec2(half, 22.0));
-    let r2 = Rect::from_min_size(pos2(x0 + half + 6.0, y), vec2(half, 22.0));
-    let src_p = source.map(|l| json!({"layer": l.0})).unwrap_or_else(|| json!({}));
-    let can_camera = app.session.is_enabled("track.camera") && !app.session.is_camera_analyzing();
-    if button(app, ui, r1, "Track Camera", can_camera, "tracker.trackCamera") {
-        run(app, &ctx, "track.camera", json!({}));
-    }
-    let can_warp = app.session.is_enabled("track.warpStabilizer") && !app.session.is_warp_analyzing();
-    if button(app, ui, r2, "Warp Stabilizer", can_warp, "tracker.warpStabilizer") {
-        run(app, &ctx, "track.warpStabilizer", json!({}));
-    }
-    y += 28.0;
-    let r1 = Rect::from_min_size(pos2(x0, y), vec2(half, 22.0));
-    let r2 = Rect::from_min_size(pos2(x0 + half + 6.0, y), vec2(half, 22.0));
-    if button(app, ui, r1, "Track Motion", can_track, "tracker.trackMotion") {
-        run(app, &ctx, "track.motion", src_p.clone());
-    }
-    if button(app, ui, r2, "Stabilize Motion", can_track, "tracker.stabilizeMotion") {
-        run(app, &ctx, "track.stabilize", src_p.clone());
-    }
-    y += 34.0;
+    top_buttons(app, ui, &ctx, x0, y, half, source);
+    y += 62.0;
     let Some(comp) = app.session.active_comp_arc() else {
         p.text(pos2(x0, y + 8.0), Align2::LEFT_CENTER, crate::i18n::tr("Open a composition to track motion."), Tokens::ui(12.0), t.text_faint);
         return;
@@ -537,7 +541,7 @@ pub fn options_dialog(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens)
                 (LowConfidence::Adapt, "Adapt Feature"),
             ];
             let cur = actions.iter().find(|(a, _)| *a == d.opts.action).map(|(_, l)| *l).unwrap_or("Adapt Feature");
-            let r = egui::ComboBox::from_id_salt("track-action")
+            let r = craft_ui::ComboBox::from_id_salt("track-action")
                 .selected_text(cur)
                 .show_ui(ui, |ui| {
                     for (a, l) in actions {
@@ -590,7 +594,7 @@ pub fn target_dialog(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens)
         ui.horizontal(|ui| {
             ui.label(crate::i18n::tr("Layer:"));
             let cur = d.target.and_then(|id| layers.iter().find(|(l, _)| *l == id)).map(|(_, n)| n.clone()).unwrap_or_else(|| "None".into());
-            let r = egui::ComboBox::from_id_salt("track-target")
+            let r = craft_ui::ComboBox::from_id_salt("track-target")
                 .selected_text(cur)
                 .width(240.0)
                 .show_ui(ui, |ui| {
@@ -623,7 +627,7 @@ pub fn apply_dialog(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
         ui.horizontal(|ui| {
             ui.label(crate::i18n::tr("Apply Dimensions:"));
             let labels = ["X and Y", "X only", "Y only"];
-            let r = egui::ComboBox::from_id_salt("track-apply-dims")
+            let r = craft_ui::ComboBox::from_id_salt("track-apply-dims")
                 .selected_text(labels[d.dims.min(2)])
                 .show_ui(ui, |ui| {
                     for (i, l) in labels.iter().enumerate() {
diff --git a/crates/ui-egui/src/panels/unsaved.rs b/crates/ui-egui/src/panels/unsaved.rs
index 05f719fa9..b5fc582b2 100644
--- a/crates/ui-egui/src/panels/unsaved.rs
+++ b/crates/ui-egui/src/panels/unsaved.rs
@@ -58,6 +58,15 @@ pub fn on_close_requested(app: &mut EffectcraftApp, ctx: &egui::Context) {
     }
 }
 
+/// On macOS a close that nothing held open quits through `-[NSApplication terminate:]` instead:
+/// closing the window while AppKit's run loop is running crashes on a Mac with a Touch Bar
+/// (#341). `on_exit` still runs. A desktop host calls it last in `logic`, after
+/// `EffectcraftApp::tick` (which runs [`on_close_requested`]) and its own work. Returns whether
+/// that quit was scheduled; other platforms close the window as before.
+pub fn quit_on_close(ctx: &egui::Context) -> bool {
+    craft_quit::on_close_request(ctx)
+}
+
 /// The project's display name: its file name, or `Untitled Project.ecproj`.
 pub fn project_name(app: &EffectcraftApp) -> String {
     app.session
@@ -207,6 +216,24 @@ mod tests {
         out.viewport_output.get(&egui::ViewportId::ROOT).is_some_and(|v| v.commands.contains(&egui::ViewportCommand::CancelClose))
     }
 
+    /// One frame of the dialogs with the window's close button pressed, through
+    /// [`on_close_requested`] and then [`quit_on_close`] as the app runs them; returns whether the
+    /// close was canceled and whether the platform quit was scheduled.
+    fn close_frame(app: &mut EffectcraftApp, ctx: &egui::Context) -> (bool, bool) {
+        let mut raw = egui::RawInput::default();
+        raw.viewports.entry(egui::ViewportId::ROOT).or_default().events.push(egui::ViewportEvent::Close);
+        let mut quits = false;
+        let mut out = ctx.run_ui(raw, |ui| {
+            app.auto.begin_frame();
+            on_close_requested(app, ui.ctx());
+            quits = quit_on_close(ui.ctx());
+            crate::panels::dialogs::show(app, ui.ctx());
+        });
+        out.textures_delta.clear();
+        let canceled = out.viewport_output.get(&egui::ViewportId::ROOT).is_some_and(|v| v.commands.contains(&egui::ViewportCommand::CancelClose));
+        (canceled, quits)
+    }
+
     fn modified(app: &mut EffectcraftApp) {
         app.session.execute("comp.new", json!({"name": "Main", "width": 64, "height": 64})).unwrap();
         assert!(app.session.is_dirty());
@@ -340,4 +367,81 @@ mod tests {
         assert!(!app.session.is_dirty());
         assert!(!frame(&mut app, &ctx, true));
     }
+
+    /// Closing the window while AppKit's run loop is running crashes on a Mac with a Touch Bar
+    /// (#341). On macOS the close is canceled and the app quits through
+    /// `-[NSApplication terminate:]`. Other platforms close the window.
+    #[test]
+    fn closing_a_saved_project_quits_through_the_platform_on_macos() {
+        let (mut app, ctx) = app();
+        let macos = cfg!(target_os = "macos");
+        assert_eq!(close_frame(&mut app, &ctx), (macos, macos));
+        assert!(app.dialog.is_none(), "nothing to ask");
+    }
+
+    #[test]
+    fn closing_a_modified_project_asks_before_the_platform_quit() {
+        let (mut app, ctx) = app();
+        modified(&mut app);
+        assert_eq!(close_frame(&mut app, &ctx), (true, false), "the prompt holds the window and nothing quits");
+        assert_eq!(app.dialog, Some(Dialog::UnsavedChanges));
+        answer_with(&mut app, &ctx, Answer::Cancel);
+        assert!(app.session.is_dirty() && !app.dialog_state.unsaved.quitting);
+        assert_eq!(close_frame(&mut app, &ctx), (true, false), "asked again after Cancel");
+        answer_with(&mut app, &ctx, Answer::Discard);
+        let macos = cfg!(target_os = "macos");
+        assert_eq!(close_frame(&mut app, &ctx), (macos, macos), "Don't Save quits");
+    }
+
+    /// While the window is minimized or hidden, eframe runs `App::logic` without `App::ui` and
+    /// still handles a close: `logic` asks about a modified project.
+    #[test]
+    fn a_close_while_only_logic_runs_asks_about_a_modified_project() {
+        let (mut app, ctx) = app();
+        modified(&mut app);
+        let mut raw = egui::RawInput::default();
+        raw.viewports.entry(egui::ViewportId::ROOT).or_default().events.push(egui::ViewportEvent::Close);
+        let mut frame = eframe::Frame::_new_kittest();
+        let out = ctx.run_logic(&raw, |ctx| eframe::App::logic(&mut app, ctx, &mut frame));
+        let canceled = out.viewport_commands.get(&egui::ViewportId::ROOT).is_some_and(|c| c.contains(&egui::ViewportCommand::CancelClose));
+        assert!(canceled, "the close is canceled");
+        assert_eq!(app.dialog, Some(Dialog::UnsavedChanges));
+    }
+
+    /// A file dialog answered in the frame that closes the window runs its command before the
+    /// close decision, so a change it makes is asked about.
+    #[test]
+    fn a_dialog_answer_runs_before_the_close_decision() {
+        let (mut app, ctx) = app();
+        assert!(!app.session.is_dirty());
+        let answer = crate::DialogAnswer { command: "comp.new".into(), key: "name", params: json!({"width": 64, "height": 64}), paths: vec!["Main".into()] };
+        app.dialog_answers.0.send(answer).unwrap();
+        let mut raw = egui::RawInput::default();
+        raw.viewports.entry(egui::ViewportId::ROOT).or_default().events.push(egui::ViewportEvent::Close);
+        let mut frame = eframe::Frame::_new_kittest();
+        let out = ctx.run_logic(&raw, |ctx| eframe::App::logic(&mut app, ctx, &mut frame));
+        let canceled = out.viewport_commands.get(&egui::ViewportId::ROOT).is_some_and(|c| c.contains(&egui::ViewportCommand::CancelClose));
+        assert!(app.session.is_dirty(), "the answer ran");
+        assert!(canceled, "the close is canceled");
+        assert_eq!(app.dialog, Some(Dialog::UnsavedChanges));
+    }
+
+    /// The tick makes the close decision and leaves the platform quit to the host, which runs it
+    /// last in `logic`, after its own work (the desktop host shows the file dialogs asked for).
+    /// On macOS `logic` cancels the close and quits; other platforms close the window.
+    #[test]
+    fn the_platform_quit_runs_after_the_tick() {
+        let (mut app, ctx) = app();
+        let mut raw = egui::RawInput::default();
+        raw.viewports.entry(egui::ViewportId::ROOT).or_default().events.push(egui::ViewportEvent::Close);
+        let frame = eframe::Frame::_new_kittest();
+        let canceled =
+            |out: &egui::LogicOutput| out.viewport_commands.get(&egui::ViewportId::ROOT).is_some_and(|c| c.contains(&egui::ViewportCommand::CancelClose));
+        let out = ctx.run_logic(&raw, |ctx| app.tick(ctx, &frame));
+        assert!(!canceled(&out), "the tick leaves a saved project's close to the host");
+        let mut frame = eframe::Frame::_new_kittest();
+        let out = ctx.run_logic(&raw, |ctx| eframe::App::logic(&mut app, ctx, &mut frame));
+        assert_eq!(canceled(&out), cfg!(target_os = "macos"), "logic quits through the platform on macOS");
+        assert!(app.dialog.is_none(), "nothing to ask");
+    }
 }
diff --git a/crates/ui-egui/src/panels/viewer.rs b/crates/ui-egui/src/panels/viewer.rs
index c9f4dd8bd..bcae99bc5 100644
--- a/crates/ui-egui/src/panels/viewer.rs
+++ b/crates/ui-egui/src/panels/viewer.rs
@@ -57,719 +57,14 @@ pub fn last_fit(ctx: &egui::Context) -> f32 {
     ctx.data(|d| d.get_temp::<f32>(egui::Id::unique("viewer-fit"))).unwrap_or(0.5)
 }
 
-/// What a drag in the viewer is doing.
-#[derive(Clone, Debug)]
-enum Gesture {
-    /// Per layer: start position and the parent-space change per comp pixel of drag in x and y.
-    Move {
-        layers: Vec<(LayerId, [f64; 3], [f64; 3], [f64; 3])>,
-        start: [f64; 2],
-        /// The grabbed layer's feature nearest the pointer (comp px at the start): it snaps.
-        snap_src: Option<[f64; 2]>,
-    },
-    Camera {
-        tool: Tool,
-    },
-    /// A bounding-box handle: scales about the anchor point so the grabbed point follows the
-    /// pointer (corners both axes, edges one), relative to the layer as the drag began; the
-    /// handle snaps.
-    Scale {
-        layer: LayerId,
-        start_scale: [f64; 3],
-        /// The grabbed point relative to the anchor, in layer pixels.
-        start_local: [f64; 2],
-        /// The handle's point relative to the anchor, in layer pixels.
-        handle: [f64; 2],
-        anchor: [f64; 2],
-        axes: [bool; 2],
-        /// Layer pixels → comp as the drag began, and its inverse.
-        l2c: Mat3,
-        inv: Mat3,
-        /// The other selected layers and their scales as the drag began: they scale by the same
-        /// ratio about their own anchor points, as in After Effects (#491).
-        others: Vec<(LayerId, [f64; 3])>,
-    },
-    Rotate {
-        layer: LayerId,
-        center: Pos2,
-        /// The pointer's angle about the centre on the last frame (degrees, as atan2 gives it).
-        last_angle: f64,
-        /// The turn so far, summed frame by frame so it keeps counting past a full revolution in
-        /// either direction (After Effects: 1x +0.0°, −1x −90.0°…) instead of wrapping at ±180°.
-        turned: f64,
-        start_rot: f64,
-        /// The other selected layers and their rotations: they turn by the same angle.
-        others: Vec<(LayerId, f64)>,
-    },
-    Anchor {
-        layer: LayerId,
-        start_anchor: [f64; 3],
-        start_pos: [f64; 3],
-        start: [f64; 2],
-        inv: Mat3,
-        l2p: Mat3,
-        /// The layer's own snap targets as the drag began (its box and path vertices).
-        own: Vec<effectcraft_engine::viewer::SnapTarget>,
-        /// Alt held as the drag began: the anchor point moves alone, so the layer shifts.
-        anchor_only: bool,
-    },
-    Pan {
-        start_pan: [f32; 2],
-    },
-    Create {
-        tool: Tool,
-        start: [f64; 2],
-    },
-    Marquee {
-        start: Pos2,
-    },
-    /// Dragging selected mask / shape path vertices: press point, the grabbed vertex (comp px,
-    /// it snaps), the comp-space move applied so far and comp → path space.
-    Vertices {
-        start: [f64; 2],
-        src: [f64; 2],
-        applied: [f64; 2],
-        inv: Mat3,
-        layer: LayerId,
-    },
-    /// Dragging a vertex's Bezier tangent (both sides symmetric unless Alt breaks them).
-    Tangent {
-        layer: LayerId,
-        mask: u64,
-        index: usize,
-        out: bool,
-        vertex: [f64; 2],
-        inv: Mat3,
-    },
-    /// Dragging a Puppet pin (comp → layer matrix inverse).
-    PuppetPin {
-        layer: LayerId,
-        pin: u64,
-        inv: Mat3,
-    },
-    /// Rotating an Advanced / Bend pin by its ring: the pin's screen centre, the pointer's last
-    /// angle (radians) and the rotation so far (°, accumulated so it can pass a full turn).
-    PuppetRotate {
-        layer: LayerId,
-        pin: u64,
-        center: Pos2,
-        last: f32,
-        rotation: f64,
-    },
-    /// Scaling an Advanced / Bend pin by its square: the pin's screen centre, the press distance
-    /// from it and the scale at the press (1 = 100 %).
-    PuppetScale {
-        layer: LayerId,
-        pin: u64,
-        center: Pos2,
-        start: f32,
-        scale: f64,
-    },
-    /// Puppet tools: a marquee selecting pins (dragged outside the layer's art, or Alt-dragged).
-    PinMarquee {
-        start: Pos2,
-    },
-    /// Object Matte tool: a box around the object (screen point where the drag began).
-    ObjectMatteBox {
-        start: Pos2,
-    },
-    /// Puppet tool Record mode (⌘/Ctrl-drag a pin): the drag is sampled in real time (seconds
-    /// since it began, effect space) and becomes keyframes on release (`puppet.recordPin`); the
-    /// current time runs along while recording.
-    PuppetRecord {
-        layer: LayerId,
-        pin: u64,
-        /// Other selected pins of the layer, moving with the dragged one.
-        others: Vec<u64>,
-        inv: Mat3,
-        began: f64,
-        cti: Tick,
-        samples: Vec<(f64, [f64; 2])>,
-    },
-    /// Pen tool: pulling the tangents of the vertex just placed.
-    Pen {
-        layer: LayerId,
-        mask: u64,
-        index: usize,
-        vertex: [f64; 2],
-        inv: Mat3,
-        press: Pos2,
-    },
-    /// Dragging a track point's feature/search region, a corner or its attach point.
-    Track {
-        layer: LayerId,
-        tracker: u64,
-        drag: super::tracker::Drag,
-    },
-    /// Motion paths, free transform, Mask Feather, guides and the region of interest
-    /// (`viewer_overlays`).
-    Overlay(ov::Drag),
-}
-
-/// Pen tool path in progress: (layer, mask uid).
-fn pen_id() -> egui::Id {
-    egui::Id::unique("viewer-pen")
-}
-
 use super::viewer_overlays::{self as ov, VertexHit};
 use super::viewer_tools as vt;
 
-const HANDLE: f32 = 7.0;
-/// How close (screen points) the pointer must be to a path vertex or tangent handle to grab it.
-const VERTEX_GRAB: f32 = 6.0;
-
-/// The reach of a path vertex at `pos` (#1042): a vertex marker sitting under, or just beside, a
-/// bounding-box handle would lose the press to the handle (the handle reaches further than the
-/// vertex), so wherever a box handle is in range the vertex reaches as far as the handle does.
-/// Vertices then win in the handle's whole zone, as in After Effects.
-fn vertex_grab_radius(pos: Pos2, handles: impl IntoIterator<Item = Pos2>) -> f32 {
-    if handles.into_iter().any(|h| h.distance(pos) < HANDLE + 2.0) { HANDLE + 2.0 } else { VERTEX_GRAB }
-}
-/// Shown when a Roto Brush tool is used in the Composition panel (#753).
-const ROTO_HINT: &str = "The Roto Brush works in the Layer panel. Double-click the layer to open it.";
-
 thread_local! {
     /// The 3D view camera of the viewer being drawn (None = the comp's active camera).
     static VIEW_CAM: std::cell::Cell<Option<CameraState>> = const { std::cell::Cell::new(None) };
 }
 
-/// Region of interest handles on screen: corners (0–3, clockwise from top-left) then edge
-/// midpoints (4 top, 5 right, 6 bottom, 7 left).
-fn roi_handles(r: Rect) -> [Pos2; 8] {
-    [r.left_top(), r.right_top(), r.right_bottom(), r.left_bottom(), r.center_top(), r.right_center(), r.center_bottom(), r.left_center()]
-}
-
-/// A drag starting on a region of interest handle: the ROI redrawn from the opposite corner (or
-/// edge, with the other axis kept).
-fn roi_drag(app: &EffectcraftApp, map: &ViewerMap, comp_rect: Rect, zoom: f32, press: Pos2) -> Option<ov::Drag> {
-    let [rx, ry, rw, rh] = app.session.state.region_of_interest?;
-    let r = Rect::from_min_size(comp_rect.min + vec2(rx as f32 * zoom, ry as f32 * zoom), vec2(rw as f32 * zoom, rh as f32 * zoom));
-    let i = roi_handles(r).iter().position(|h| h.distance(press) < 6.0)?;
-    let (x0, y0, x1, y1) = (rx, ry, rx + rw, ry + rh);
-    let _ = map;
-    Some(match i {
-        0 => ov::Drag::Roi { start: [x1, y1], keep: [None, None] },
-        1 => ov::Drag::Roi { start: [x0, y1], keep: [None, None] },
-        2 => ov::Drag::Roi { start: [x0, y0], keep: [None, None] },
-        3 => ov::Drag::Roi { start: [x1, y0], keep: [None, None] },
-        4 => ov::Drag::Roi { start: [x1, y1], keep: [Some(x0), None] },
-        5 => ov::Drag::Roi { start: [x0, y0], keep: [None, Some(y1)] },
-        6 => ov::Drag::Roi { start: [x0, y0], keep: [Some(x1), None] },
-        _ => ov::Drag::Roi { start: [x1, y0], keep: [None, Some(y1)] },
-    })
-}
-
-/// The camera the viewer shows (view camera or the comp's active camera).
-fn cam_state(ctx: &EvalCtx) -> CameraState {
-    VIEW_CAM.with(|c| c.get()).unwrap_or_else(|| three_d::active_camera(ctx))
-}
-
-/// Layer → comp (viewer) matrix through the current 3D view.
-pub(crate) fn l2c(ctx: &EvalCtx, layer: &Layer) -> (Mat3, f64) {
-    match VIEW_CAM.with(|c| c.get()) {
-        Some(cam) if layer.is_3d() => (three_d::layer_to_view(ctx, layer, &cam), 0.0),
-        _ => ctx.layer_to_comp(layer),
-    }
-}
-
-/// `l2c` (layer → comp) applied from effect space instead: effect points and Puppet pins,
-/// measured from the top-left of the layer's effect bounds (see `effect_bounds`).
-pub(crate) fn from_effect_space(ctx: &EvalCtx, layer: &Layer, l2c: Mat3) -> Mat3 {
-    let o = ctx.effect_bounds(layer).1;
-    l2c * Mat3::translate(gv2(o[0], o[1]))
-}
-
-/// Effect space → comp (viewer) matrix through the current 3D view.
-pub(crate) fn fx2c(ctx: &EvalCtx, layer: &Layer) -> Mat3 {
-    from_effect_space(ctx, layer, l2c(ctx, layer).0)
-}
-
-/// The selected, unlocked layers of `comp` other than `layer` (when `layer` is one of them): a
-/// handle or Rotation tool drag on one changes them all.
-fn selected_others<'a>(app: &EffectcraftApp, comp: &'a Comp, layer: LayerId) -> Vec<&'a Layer> {
-    let sel = &app.session.state.selected_layers;
-    if !sel.contains(&layer) {
-        return vec![];
-    }
-    sel.iter().filter(|id| **id != layer).filter_map(|id| comp.layer(*id)).filter(|l| !l.switches.locked && l.transform().is_some()).collect()
-}
-
-/// The least homogeneous depth (`w`: the distance in front of a perspective camera in pixels, 1
-/// for 2D layers and orthographic views) a viewer outline is drawn at: points at or behind the
-/// camera would flip through infinity and draw long lines across the viewer (#572).
-const NEAR_W: f64 = 0.5;
-
-/// `p` through the homography `m` before the perspective divide: (x, y, w).
-fn homogeneous(m: &Mat3, p: [f64; 2]) -> [f64; 3] {
-    let r = |i: usize| m.0.get(i).map_or(0.0, |row| row[0] * p[0] + row[1] * p[1] + row[2]);
-    [r(0), r(1), r(2)]
-}
-
-/// The closed polygon `poly` (layer pixels) through `m`, clipped to the part in front of the
-/// camera's near plane (comp pixels; empty when none of it is).
-fn project_clipped(m: &Mat3, poly: &[[f64; 2]]) -> Vec<[f64; 2]> {
-    let h: Vec<[f64; 3]> = poly.iter().map(|p| homogeneous(m, *p)).collect();
-    let mut out = vec![];
-    for (i, a) in h.iter().enumerate() {
-        let Some(b) = h.get((i + 1) % h.len()) else { continue };
-        let (ina, inb) = (a[2] >= NEAR_W, b[2] >= NEAR_W);
-        if ina {
-            out.push(*a);
-        }
-        if ina != inb {
-            let t = (NEAR_W - a[2]) / (b[2] - a[2]);
-            out.push([a[0] + (b[0] - a[0]) * t, a[1] + (b[1] - a[1]) * t, NEAR_W]);
-        }
-    }
-    out.iter().map(|q| [q[0] / q[2], q[1] / q[2]]).filter(|q| q[0].is_finite() && q[1].is_finite()).collect()
-}
-
-/// The segment a → b (world space) through the projection `pc`, clipped at the near plane.
-fn project_segment(pc: &effectcraft_engine::geom::Mat4, a: effectcraft_engine::geom::Vec3, b: effectcraft_engine::geom::Vec3) -> Option<[[f64; 2]; 2]> {
-    let h = |p: effectcraft_engine::geom::Vec3| {
-        let r = |i: usize| pc.0.get(i).map_or(0.0, |row| row[0] * p.x + row[1] * p.y + row[2] * p.z + row[3]);
-        [r(0), r(1), r(3)]
-    };
-    let (mut ha, mut hb) = (h(a), h(b));
-    if ha[2] < NEAR_W && hb[2] < NEAR_W {
-        return None;
-    }
-    let cut = |p: [f64; 3], q: [f64; 3]| {
-        let t = (NEAR_W - p[2]) / (q[2] - p[2]);
-        [p[0] + (q[0] - p[0]) * t, p[1] + (q[1] - p[1]) * t, NEAR_W]
-    };
-    if ha[2] < NEAR_W {
-        ha = cut(ha, hb);
-    } else if hb[2] < NEAR_W {
-        hb = cut(hb, ha);
-    }
-    let d = |q: [f64; 3]| [q[0] / q[2], q[1] / q[2]];
-    let s = [d(ha), d(hb)];
-    s.iter().flatten().all(|v| v.is_finite()).then_some(s)
-}
-
-/// The content box corners (layer pixels) of `layer`.
-fn box_corners(b: [f64; 4]) -> [[f64; 2]; 4] {
-    [[b[0], b[1]], [b[2], b[1]], [b[2], b[3]], [b[0], b[3]]]
-}
-
-/// Layer → comp matrix and its bounds quad (in comp pixels). None for a 3D layer reaching to or
-/// behind the camera (its quad would flip; [`layer_outline`] draws the part in front).
-pub(crate) fn layer_quad(ctx: &EvalCtx, layer: &Layer) -> Option<(Mat3, [[f64; 2]; 4], [f64; 4])> {
-    let b = effectcraft_engine::render::content_bounds(ctx, layer)?;
-    let (m, _) = l2c(ctx, layer);
-    let corners = box_corners(b);
-    if corners.iter().any(|p| homogeneous(&m, *p)[2] < NEAR_W) {
-        return None;
-    }
-    let pts = corners.map(|p| {
-        let q = m.apply(gv2(p[0], p[1]));
-        [q.x, q.y]
-    });
-    Some((m, pts, b))
-}
-
-/// The outline of a layer's content box in comp pixels, clipped at the camera's near plane.
-pub(crate) fn layer_outline(ctx: &EvalCtx, layer: &Layer) -> Vec<[f64; 2]> {
-    let Some(b) = effectcraft_engine::render::content_bounds(ctx, layer) else { return vec![] };
-    project_clipped(&l2c(ctx, layer).0, &box_corners(b))
-}
-
-/// Which axes a bounding-box handle scales: corners (0–3) both; the top and bottom edges (4, 6)
-/// y; the right and left edges (5, 7) x.
-fn handle_axes(handle: usize) -> [bool; 2] {
-    match handle {
-        4 | 6 => [false, true],
-        5 | 7 => [true, false],
-        _ => [true, true],
-    }
-}
-
-/// A bounding-box handle's point in layer pixels (`b`: the content box; handles as in
-/// [`handle_axes`], the corners clockwise from the top left, then the top, right, bottom and
-/// left edges' midpoints).
-fn handle_point(b: [f64; 4], handle: usize) -> [f64; 2] {
-    let (cx, cy) = ((b[0] + b[2]) / 2.0, (b[1] + b[3]) / 2.0);
-    match handle {
-        0 => [b[0], b[1]],
-        1 => [b[2], b[1]],
-        2 => [b[2], b[3]],
-        3 => [b[0], b[3]],
-        4 => [cx, b[1]],
-        5 => [b[2], cy],
-        6 => [cx, b[3]],
-        _ => [b[0], cy],
-    }
-}
-
-/// The resize cursor over bounding-box handle `handle` of the on-screen box `sq` (corners
-/// clockwise from the top left, handles as in [`handle_point`]): along the direction the handle
-/// scales, so it turns with the layer, as in After Effects. A corner points between its two
-/// edges (the box's diagonal whatever its proportions), an edge handle across its edge.
-fn handle_cursor(sq: &[Pos2], handle: usize) -> egui::CursorIcon {
-    let at = |k: usize| sq.get(k % 4).copied().unwrap_or(Pos2::ZERO);
-    let dir = if handle < 4 {
-        let c = at(handle);
-        (c - at(handle + 3)).normalized() + (c - at(handle + 1)).normalized()
-    } else {
-        let e = at(handle - 3) - at(handle - 4);
-        vec2(-e.y, e.x)
-    };
-    // Screen y points down: 45° is the south-east diagonal.
-    let a = dir.y.atan2(dir.x).to_degrees().rem_euclid(180.0);
-    if !(22.5..157.5).contains(&a) {
-        egui::CursorIcon::ResizeHorizontal
-    } else if a < 67.5 {
-        egui::CursorIcon::ResizeNwSe
-    } else if a < 112.5 {
-        egui::CursorIcon::ResizeVertical
-    } else {
-        egui::CursorIcon::ResizeNeSw
-    }
-}
-
-/// The scale ratio (x, y) that puts the point grabbed at `start` (relative to the anchor, layer
-/// pixels) under the pointer at `cur`. `uniform` (Shift on a corner) keeps the aspect ratio,
-/// following the pointer along the handle's diagonal. Dragging past the anchor flips the layer,
-/// as in After Effects; an axis whose grabbed point sits on the anchor keeps its scale.
-fn drag_ratio(start: [f64; 2], cur: [f64; 2], axes: [bool; 2], uniform: bool) -> [f64; 2] {
-    if uniform {
-        let d2 = start[0] * start[0] + start[1] * start[1];
-        let f = if d2 > 1e-6 { (cur[0] * start[0] + cur[1] * start[1]) / d2 } else { 1.0 };
-        return [f, f];
-    }
-    [0, 1].map(|k| if axes[k] && start[k].abs() > 1e-3 { cur[k] / start[k] } else { 1.0 })
-}
-
-/// Snap a handle drag (#252): the handle (`h`, layer pixels from the anchor point `a` as the
-/// drag began; `l2c` that layer space → comp) at scale ratio `f` goes through `snap` (a comp
-/// point → its correction), and the ratio that puts the handle where it snapped comes back.
-/// A `uniform` drag slides the handle along its line from the anchor point to the nearer snapped
-/// line; otherwise each scaled axis takes the snapped point.
-fn snap_handle(f: [f64; 2], h: [f64; 2], a: [f64; 2], l2c: &Mat3, axes: [bool; 2], uniform: bool, snap: impl FnOnce([f64; 2]) -> [f64; 2]) -> [f64; 2] {
-    let at = |f: [f64; 2]| {
-        let q = l2c.apply(gv2(a[0] + f[0] * h[0], a[1] + f[1] * h[1]));
-        [q.x, q.y]
-    };
-    let p = at(f);
-    let c = snap(p);
-    let s = [p[0] + c[0], p[1] + c[1]];
-    if uniform {
-        let o = at([0.0; 2]);
-        let d = [p[0] - o[0], p[1] - o[1]];
-        let k = [0, 1].into_iter().filter(|k| c[*k] != 0.0 && d[*k].abs() > 1e-9).min_by(|x, y| c[*x].abs().total_cmp(&c[*y].abs()));
-        return k.map_or(f, |k| f.map(|v| v * (s[k] - o[k]) / d[k]));
-    }
-    let Some(inv) = l2c.inverse().filter(|_| c != [0.0; 2]) else { return f };
-    let q = inv.apply(gv2(s[0], s[1]));
-    let q = [q.x - a[0], q.y - a[1]];
-    [0, 1].map(|k| if axes[k] && h[k].abs() > 1e-9 { q[k] / h[k] } else { f[k] })
-}
-
-/// The turn from angle `from` to angle `to` (degrees), wrapped to (−180°, 180°]: the shortest way
-/// round, so summing it frame by frame follows the pointer across atan2's ±180° seam and past full
-/// revolutions. Non-finite input turns by nothing.
-fn turn_delta(from: f64, to: f64) -> f64 {
-    let d = to - from;
-    if !d.is_finite() {
-        return 0.0;
-    }
-    let w = (d + 180.0).rem_euclid(360.0) - 180.0;
-    if w <= -180.0 { w + 360.0 } else { w }
-}
-
-/// The Rotation tool's value: the rotation as the drag began plus the turn so far (which may span
-/// revolutions), snapped to 45° steps with Shift.
-fn rotate_value(start_rot: f64, turned: f64, shift: bool) -> f64 {
-    let r = start_rot + turned;
-    let r = if r.is_finite() { r } else { start_rot };
-    if shift { (r / 45.0).round() * 45.0 } else { r }
-}
-
-/// A drag `d` (comp pixels), kept to the axis it moves along most when `shift` is held.
-fn one_axis(d: [f64; 2], shift: bool) -> [f64; 2] {
-    if !shift {
-        d
-    } else if d[0].abs() > d[1].abs() {
-        [d[0], 0.0]
-    } else {
-        [0.0, d[1]]
-    }
-}
-
-fn point_in_quad(p: [f64; 2], q: &[[f64; 2]; 4]) -> bool {
-    let mut sign = 0.0;
-    for i in 0..4 {
-        let a = q[i];
-        let b = q[(i + 1) % 4];
-        let c = (b[0] - a[0]) * (p[1] - a[1]) - (b[1] - a[1]) * (p[0] - a[0]);
-        if c.abs() < 1e-9 {
-            continue;
-        }
-        if sign == 0.0 {
-            sign = c.signum();
-        } else if c.signum() != sign {
-            return false;
-        }
-    }
-    true
-}
-
-/// Separating-axis test: a marquee may cross a layer without containing any corner.
-fn quad_intersects_box(q: &[[f64; 2]; 4], a: [f64; 2], b: [f64; 2]) -> bool {
-    if q.iter().flatten().chain(a.iter()).chain(b.iter()).any(|v| !v.is_finite()) {
-        return false;
-    }
-    let lo = [a[0].min(b[0]), a[1].min(b[1])];
-    let hi = [a[0].max(b[0]), a[1].max(b[1])];
-    let rect = [lo, [hi[0], lo[1]], hi, [lo[0], hi[1]]];
-    let axes = [[1.0, 0.0], [0.0, 1.0]].into_iter().chain((0..4).map(|i| {
-        let j = (i + 1) % 4;
-        [q[j][1] - q[i][1], q[i][0] - q[j][0]]
-    }));
-    for axis in axes {
-        let project = |p: &[f64; 2]| p[0] * axis[0] + p[1] * axis[1];
-        let (qmin, qmax) = q.iter().map(project).fold((f64::INFINITY, f64::NEG_INFINITY), |(lo, hi), v| (lo.min(v), hi.max(v)));
-        let (rmin, rmax) = rect.iter().map(project).fold((f64::INFINITY, f64::NEG_INFINITY), |(lo, hi), v| (lo.min(v), hi.max(v)));
-        if qmax < rmin || rmax < qmin {
-            return false;
-        }
-    }
-    true
-}
-
-/// Parent-space linear inverse (to convert a comp-space drag delta into a position delta).
-fn parent_inverse(ctx: &EvalCtx, layer: &Layer) -> Mat3 {
-    match layer.parent.and_then(|p| ctx.comp.layer(p)) {
-        Some(p) => {
-            let w = ctx.world_matrix(p);
-            let m = Mat3([[w.0[0][0], w.0[0][1], 0.0], [w.0[1][0], w.0[1][1], 0.0], [0.0, 0.0, 1.0]]);
-            m.inverse().unwrap_or(Mat3::IDENTITY)
-        }
-        None => Mat3::IDENTITY,
-    }
-}
-
-/// Draw the extra views of a 2- or 4-view layout and return the main view's rectangle.
-fn aux_views(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    comp: &effectcraft_engine::project::Comp,
-    cid: effectcraft_engine::project::ItemId,
-    full: Rect,
-    bg: Color32,
-) -> Rect {
-    let n = app.session.state.view_layout;
-    if n < 2 {
-        return full;
-    }
-    let gap = 2.0;
-    let views = app.session.state.views3d.get(&cid).cloned().unwrap_or_default();
-    let (main, aux): (Rect, Vec<(Rect, View3D)>) = if n == 2 {
-        let mid = full.center().x;
-        (
-            Rect::from_min_max(pos2(mid + gap / 2.0, full.min.y), full.max),
-            vec![(Rect::from_min_max(full.min, pos2(mid - gap / 2.0, full.max.y)), views.pane(0))],
-        )
-    } else {
-        let c = full.center();
-        let q = |x0: f32, y0: f32, x1: f32, y1: f32| Rect::from_min_max(pos2(x0, y0), pos2(x1, y1));
-        (
-            q(c.x + gap / 2.0, c.y + gap / 2.0, full.max.x, full.max.y),
-            vec![
-                (q(full.min.x, full.min.y, c.x - gap / 2.0, c.y - gap / 2.0), views.pane(0)),
-                (q(c.x + gap / 2.0, full.min.y, full.max.x, c.y - gap / 2.0), views.pane(1)),
-                (q(full.min.x, c.y + gap / 2.0, c.x - gap / 2.0, full.max.y), views.pane(2)),
-            ],
-        )
-    };
-    let ctx = ui.ctx().clone();
-    let p = ui.painter().clone();
-    p.rect_filled(full, 0.0, Color32::from_black_alpha(200));
-    let t = app.session.time();
-    let (cw, ch) = (comp.width as f32, comp.height as f32);
-    let share = app.session.state.share_view_options;
-    // The camera and light wireframes of each view (as in After Effects, where every view of the
-    // layout shows them), evaluated on a snapshot of the project.
-    let snap_project = app.session.project.clone();
-    let snap_expr = app.session.expr.clone();
-    let ectx = EvalCtx { project: &snap_project, comp_id: cid, comp, time: t, expr: snap_expr.as_deref(), footage: None };
-    let selected = app.session.state.selected_layers.clone();
-    let mut picked: Option<(usize, View3D)> = None;
-    for (i, (r, v)) in aux.into_iter().enumerate() {
-        p.rect_filled(r, 0.0, bg);
-        let fit = ((r.width() - 20.0) / cw).min((r.height() - 20.0) / ch).max(0.01);
-        let cr = Rect::from_center_size(r.center(), vec2(cw * fit, ch * fit));
-        let scale = (fit * ctx.pixels_per_point()).min(1.0) as f64;
-        // The Active Camera pane renders through the comp's own camera; the others through their
-        // view camera.
-        let through_active = v == View3D::ActiveCamera;
-        let cam = if through_active { three_d::active_camera(&ectx) } else { views.cam(v, comp.width as f64, comp.height as f64).state() };
-        let key = {
-            use std::hash::{Hash, Hasher};
-            let mut h = std::collections::hash_map::DefaultHasher::new();
-            (app.session.revision, cid.0, t.0, i, scale.to_bits(), format!("{cam:?}")).hash(&mut h);
-            h.finish()
-        };
-        let id = egui::Id::unique(("viewer-aux", i));
-        let cached: Option<(u64, egui::TextureHandle)> = ctx.data(|d| d.get_temp(id));
-        let tex = match cached {
-            Some((k, tex)) if k == key => tex,
-            _ => {
-                let opts = effectcraft_engine::render::RenderOpts {
-                    scale,
-                    view: (comp.has_3d() && !through_active).then_some(cam),
-                    draft: true,
-                    ..Default::default()
-                };
-                let img = app.session.render(cid, t, opts);
-                let tex = crate::frames::load_fitted(&ctx, format!("viewer-aux-{i}"), crate::frames::to_color_image(&img), egui::TextureOptions::LINEAR);
-                ctx.data_mut(|d| d.insert_temp(id, (key, tex.clone())));
-                tex
-            }
-        };
-        let b = comp.background;
-        p.rect_filled(cr, 0.0, Color32::from_rgb((b[0] * 255.0) as u8, (b[1] * 255.0) as u8, (b[2] * 255.0) as u8));
-        p.image(tex.id(), cr, Rect::from_min_max(pos2(0.0, 0.0), pos2(1.0, 1.0)), Color32::WHITE);
-        p.rect_stroke(cr, 0.0, Stroke::new(1.0, Color32::from_black_alpha(160)), StrokeKind::Outside);
-        if share && app.ui.viewer.safe_margins {
-            for k in [0.9, 0.8] {
-                p.rect_stroke(Rect::from_center_size(cr.center(), cr.size() * k), 0.0, Stroke::new(1.0, Color32::from_white_alpha(120)), StrokeKind::Middle);
-            }
-        }
-        if comp.has_3d() {
-            let map = ViewerMap { origin: cr.min, zoom: fit, comp: [cw, ch], area: r };
-            draw_rigs(app, &p.with_clip_rect(r), &map, &ectx, &selected, cam, through_active, Some(v.id()));
-        }
-        let label = if comp.has_3d() { v.label() } else { crate::i18n::tr("Active Camera") };
-        p.text(r.left_bottom() + vec2(8.0, -8.0), Align2::LEFT_BOTTOM, label, Tokens::ui(11.0), Color32::from_white_alpha(200));
-        app.auto.add(&format!("viewer.view.{}", v.id()), r, label);
-        if comp.has_3d()
-            && let Some(chosen) = pane_selector(app, ui, i + 1, r, v)
-        {
-            picked = Some((i + 1, chosen));
-        }
-    }
-    if let Some((pane, v)) = picked
-        && let Err(e) = app.session.execute("view.setPaneView", json!({"pane": pane, "view": v.id(), "comp": cid.0}))
-    {
-        app.ui.status = e.to_string();
-    }
-    main
-}
-
-/// The view selector in the top-left corner of pane `pane` (1 to 3) of a multi-view layout, a
-/// popup of every 3D view like the toolbar's 3D View menu. Returns the view chosen this frame.
-fn pane_selector(app: &mut EffectcraftApp, ui: &mut egui::Ui, pane: usize, area: Rect, current: View3D) -> Option<View3D> {
-    let t = app.tokens;
-    let r = Rect::from_min_size(area.min + vec2(6.0, 6.0), vec2(124.0, 20.0));
-    let pid = egui::Id::unique(("viewer-pane-view", pane));
-    let response = widgets::dropdown(ui, r, crate::i18n::tr(current.label()), &t, pid);
-    if response.clicked() {
-        let open = widgets::popup_is_open(ui, pid);
-        ui.data_mut(|d| d.insert_temp(pid.with("open"), !open));
-    }
-    app.auto.add_response(&format!("viewer.view.{pane}.type"), &response, "View of pane");
-    if !widgets::popup_is_open(ui, pid) {
-        return None;
-    }
-    let chosen = widgets::popup_list(ui, pid, r.left_bottom() + vec2(0.0, 2.0), r, View3D::ALL.len(), 0, |ui| {
-        ui.set_min_width(124.0);
-        let mut chosen = None;
-        for (k, v) in View3D::ALL.iter().enumerate() {
-            let item = ui.selectable_label(*v == current, crate::i18n::tr(v.label()));
-            app.auto.add(&format!("viewer.view.{pane}.typeItem.{k}"), item.rect, v.label());
-            if item.clicked() {
-                chosen = Some(*v);
-            }
-        }
-        chosen
-    });
-    chosen.filter(|v| *v != current)
-}
-
-/// View ▸ Split with New Locked Viewer: the locked viewer on the left of the Composition panel
-/// (its comp and 3D view stay put whatever comp is active). Returns the main viewer's rectangle.
-fn locked_pane(app: &mut EffectcraftApp, ui: &mut egui::Ui, full: Rect, bg: Color32) -> Rect {
-    let Some(lv) = app.session.state.locked_viewer else { return full };
-    let Some(comp) = app.session.project.comp_arc(lv.comp) else { return full };
-    let name = app.session.project.item(lv.comp).map(|i| i.name.clone()).unwrap_or_default();
-    let gap = 2.0;
-    let mid = full.center().x;
-    let r = Rect::from_min_max(full.min, pos2(mid - gap / 2.0, full.max.y));
-    let main = Rect::from_min_max(pos2(mid + gap / 2.0, full.min.y), full.max);
-    let ctx = ui.ctx().clone();
-    let p = ui.painter().clone();
-    p.rect_filled(Rect::from_min_max(pos2(r.max.x, full.min.y), pos2(main.min.x, full.max.y)), 0.0, Color32::from_black_alpha(200));
-    p.rect_filled(r, 0.0, bg);
-    let (cw, ch) = (comp.width as f32, comp.height as f32);
-    let fit = ((r.width() - 20.0) / cw).min((r.height() - 44.0) / ch).max(0.01);
-    let cr = Rect::from_center_size(r.center(), vec2(cw * fit, ch * fit));
-    let scale = (fit * ctx.pixels_per_point()).min(1.0) as f64;
-    let t = app.session.time_of(lv.comp);
-    let cam = (lv.view != View3D::ActiveCamera && comp.has_3d())
-        .then(|| app.session.state.views3d.get(&lv.comp).cloned().unwrap_or_default().cam(lv.view, comp.width as f64, comp.height as f64).state());
-    let dc = effectcraft_engine::viewer::DisplayColor::of(&app.session);
-    // The display conversion's inputs, keyed as in the main viewer's texture caches.
-    let dc_key = format!("{cam:?}{}", super::viewer_tools::display_key(app, dc.is_some()));
-    let key = {
-        use std::hash::{Hash, Hasher};
-        let mut h = std::collections::hash_map::DefaultHasher::new();
-        (app.session.revision, lv.comp.0, t.0, scale.to_bits(), dc_key).hash(&mut h);
-        h.finish()
-    };
-    let id = egui::Id::unique("viewer-locked");
-    let cached: Option<(u64, egui::TextureHandle)> = ctx.data(|d| d.get_temp(id));
-    let tex = match cached {
-        Some((k, tex)) if k == key => tex,
-        _ => {
-            let opts = effectcraft_engine::render::RenderOpts { scale, view: cam, ..Default::default() };
-            let img = app.session.render(lv.comp, t, opts);
-            let mut ci = crate::frames::to_color_image(&img);
-            if let Some(dc) = dc {
-                let mut px: Vec<[u8; 4]> = ci.pixels.iter().map(|c| c.to_array()).collect();
-                dc.apply(&mut px);
-                ci = egui::ColorImage::new(ci.size, px.into_iter().map(|a| Color32::from_rgba_premultiplied(a[0], a[1], a[2], a[3])).collect());
-            }
-            let tex = crate::frames::load_fitted(&ctx, "viewer-locked", ci, egui::TextureOptions::LINEAR);
-            ctx.data_mut(|d| d.insert_temp(id, (key, tex.clone())));
-            tex
-        }
-    };
-    let b = comp.background;
-    p.rect_filled(cr, 0.0, Color32::from_rgb((b[0] * 255.0) as u8, (b[1] * 255.0) as u8, (b[2] * 255.0) as u8));
-    p.image(tex.id(), cr, Rect::from_min_max(pos2(0.0, 0.0), pos2(1.0, 1.0)), Color32::WHITE);
-    p.rect_stroke(cr, 0.0, Stroke::new(1.0, Color32::from_black_alpha(160)), StrokeKind::Outside);
-    let label = crate::i18n::tr_args("Locked: {} — {}", &[&name, &(if comp.has_3d() { lv.view.label() } else { crate::i18n::tr("Active Camera") })]);
-    p.text(r.left_top() + vec2(8.0, 8.0), Align2::LEFT_TOP, &label, Tokens::ui(11.0), Color32::from_white_alpha(210));
-    app.auto.add("viewer.locked", r, &label);
-    // Close the locked viewer.
-    let close = Rect::from_min_size(pos2(r.max.x - 26.0, r.min.y + 4.0), vec2(20.0, 20.0));
-    let resp = ui.interact(close, egui::Id::unique("viewer-locked-close"), Sense::click());
-    p.text(close.center(), Align2::CENTER_CENTER, "\u{00d7}", Tokens::ui(14.0), if resp.hovered() { Color32::WHITE } else { Color32::from_white_alpha(170) });
-    app.auto.add("viewer.locked.close", close, "Close Locked Viewer");
-    if resp.clicked() {
-        let _ = app.session.execute("view.closeLockedViewer", serde_json::json!({}));
-    }
-    main
-}
-
-pub(crate) fn checker(p: &egui::Painter, r: Rect) {
-    let s = 10.0;
-    p.rect_filled(r, 0.0, Color32::from_gray(0xcc));
-    let mut y = r.min.y;
-    let mut row = 0;
-    while y < r.max.y {
-        let mut x = r.min.x + if row % 2 == 0 { 0.0 } else { s };
-        while x < r.max.x {
-            p.rect_filled(Rect::from_min_max(pos2(x, y), pos2((x + s).min(r.max.x), (y + s).min(r.max.y))), 0.0, Color32::from_gray(0x99));
-            x += 2.0 * s;
-        }
-        y += s;
-        row += 1;
-    }
-}
-
 /// Draw the Composition viewer in `rect` and handle its input for one pass.
 /// Publishes the fit magnification and `ViewerMap`, requests and draws the frame, then paints the nav breadcrumbs,
 /// view layout, guides/grid, layer boxes, handles, anchors, 3D gizmos, motion paths, masks, puppet pins and tracker
@@ -777,6 +72,52 @@ pub(crate) fn checker(p: &egui::Painter, r: Rect) {
 /// (move/scale/rotate/anchor/camera/shape/mask/guide edits, picks, marquees); failures worth showing go to
 /// `app.ui.status`, while per-frame drag updates ignore errors so a gesture is not aborted mid-drag. With no active
 /// composition it draws `empty_state` and returns.
+/// What the passes of one viewer frame share (see [`show`]).
+struct Vw<'a> {
+    t: Tokens,
+    cid: effectcraft_engine::project::ItemId,
+    nav: Rect,
+    bar: Rect,
+    err_bar: Rect,
+    err_h: f32,
+    pasteboard: Color32,
+    area: Rect,
+    outer: Rect,
+    comp_rect: Rect,
+    zoom: f32,
+    ppp: f32,
+    cw: f32,
+    ch: f32,
+    map: ViewerMap,
+    time: Tick,
+    overlays: bool,
+    mods: egui::Modifiers,
+    space_pan: bool,
+    text_owns: bool,
+    gid: egui::Id,
+    track_cur: Option<(LayerId, effectcraft_engine::project::Uid)>,
+    has_3d: bool,
+    ctx: egui::Context,
+    comp_name: String,
+    p: egui::Painter,
+    painter: egui::Painter,
+    selected: Vec<LayerId>,
+    sel_vertices: Vec<effectcraft_engine::VertexRef>,
+    ft: Option<ov::FtBox>,
+    comp: &'a Comp,
+    gesture: Option<Gesture>,
+    handle_hits: Vec<(LayerId, usize, Pos2, egui::CursorIcon)>,
+    axis_hits: Vec<(LayerId, [Pos2; 2], [f64; 3], [f64; 3])>,
+    vertex_hits: Vec<VertexHit>,
+    vertex_marks: Vec<ov::VertexMark>,
+    key_hits: Vec<ov::KeyHit>,
+    motion_frames: Vec<ov::PathFrame>,
+    paths: Vec<ov::PathInfo>,
+    track_hits: Vec<super::tracker::Hit>,
+    pin_hits: Vec<super::puppet_tool::PinHit>,
+    puppet_layers: Vec<(&'a Layer, super::puppet_tool::Overlay)>,
+}
+
 pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let t = app.tokens;
     let ctx = ui.ctx().clone();
@@ -788,7 +129,75 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let comp_name = app.session.project.item(cid).map(|i| i.name.clone()).unwrap_or_default();
     let p = ui.painter().clone();
     VIEW_CAM.with(|c| c.set(app.session.view_camera(cid)));
+    let mut v = Vw {
+        t,
+        cid,
+        nav: Rect::NOTHING,
+        bar: Rect::NOTHING,
+        err_bar: Rect::NOTHING,
+        err_h: 0.0,
+        pasteboard: Color32::BLACK,
+        area: Rect::NOTHING,
+        outer: Rect::NOTHING,
+        comp_rect: Rect::NOTHING,
+        zoom: 1.0,
+        ppp: 1.0,
+        cw: 0.0,
+        ch: 0.0,
+        map: ViewerMap { origin: Pos2::ZERO, zoom: 1.0, comp: [0.0; 2], area: Rect::NOTHING },
+        time: Tick::ZERO,
+        overlays: false,
+        mods: egui::Modifiers::NONE,
+        space_pan: false,
+        text_owns: false,
+        gid: egui::Id::unique("viewer-gesture"),
+        track_cur: None,
+        has_3d: false,
+        ctx: ctx.clone(),
+        comp_name,
+        painter: p.clone(),
+        p,
+        selected: vec![],
+        sel_vertices: vec![],
+        ft: None,
+        comp: &comp,
+        gesture: None,
+        handle_hits: vec![],
+        axis_hits: vec![],
+        vertex_hits: vec![],
+        vertex_marks: vec![],
+        key_hits: vec![],
+        motion_frames: vec![],
+        paths: vec![],
+        track_hits: vec![],
+        pin_hits: vec![],
+        puppet_layers: vec![],
+    };
+    phase_nav(app, ui, rect, &mut v);
+    phase_layout(app, ui, rect, &mut v);
+    phase_frame(app, &mut v);
+    let snap_project = app.session.project.clone();
+    let snap_expr = app.session.expr.clone();
+    let ectx = EvalCtx { project: &snap_project, comp_id: cid, comp: &comp, time: v.time, expr: snap_expr.as_deref(), footage: None };
+    phase_guides(app, &ectx, &mut v);
+    phase_layers(app, ui, &ectx, &mut v);
+    phase_scene(app, &ectx, &mut v);
+    phase_rigs(app, ui, &ectx, &mut v);
+    let resp = phase_menu(app, ui, &ectx, &mut v);
+    phase_hover(app, ui, &ectx, &resp, &mut v);
+    phase_press(app, ui, &ectx, &resp, &mut v);
+    phase_dragstart(app, ui, &ectx, &resp, &mut v);
+    phase_drag(app, ui, &ectx, &resp, &mut v);
+    phase_stopped(app, ui, &ectx, &resp, &mut v);
+    phase_clicked(app, &ectx, &resp, &mut v);
+    phase_dblclick(app, &ectx, &resp, &mut v);
+    phase_tail(app, ui, &ectx, &mut v);
+}
 
+fn phase_nav(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect, v: &mut Vw<'_>) {
+    let t = v.t;
+    let cid = v.cid;
+    let p = v.p.clone();
     // Navigator bar (open comps as breadcrumbs). After Effects shows a single breadcrumb row:
     // when the Composition Navigator (nested comp flow) is above the viewer, this row is left
     // out.
@@ -821,7 +230,16 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
         x = r.max.x + 4.0;
     }
+    v.nav = nav;
+}
 
+fn phase_layout(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect, v: &mut Vw<'_>) {
+    let t = v.t;
+    let cid = v.cid;
+    let nav = v.nav;
+    let ctx = v.ctx.clone();
+    let p = v.p.clone();
+    let comp = v.comp;
     // Bottom control bar.
     let bar_h = 36.0;
     let bar = Rect::from_min_max(pos2(rect.min.x, rect.max.y - bar_h), rect.max);
@@ -833,7 +251,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     // View ▸ Switch View Layout: extra views (Top / Front / Right) beside the main view, which
     // keeps the overlays and the interaction.
     let full = locked_pane(app, ui, full, pasteboard);
-    let area = aux_views(app, ui, &comp, cid, full, pasteboard);
+    let area = aux_views(app, ui, comp, cid, full, pasteboard);
     p.rect_filled(area, 0.0, pasteboard);
     // View ▸ Show Rulers takes a strip on the top and left.
     let outer = area;
@@ -856,8 +274,30 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let painter = p.with_clip_rect(area);
     // Settings ▸ 3D ▸ Extended Viewer: custom 3D views (and Draft 3D) render the visible
     // pasteboard too, so 3D layers reaching past the comp frame stay visible there.
-    app.ui.viewer.extended = extended_region(app, &comp, cid, map);
+    app.ui.viewer.extended = extended_region(app, comp, cid, map);
+    v.bar = bar;
+    v.err_bar = err_bar;
+    v.err_h = err_h;
+    v.pasteboard = pasteboard;
+    v.area = area;
+    v.outer = outer;
+    v.comp_rect = comp_rect;
+    v.zoom = zoom;
+    v.ppp = ppp;
+    v.cw = cw;
+    v.ch = ch;
+    v.map = map;
+    v.painter = painter;
+}
 
+fn phase_frame(app: &mut EffectcraftApp, v: &mut Vw<'_>) {
+    let cid = v.cid;
+    let comp_rect = v.comp_rect;
+    let zoom = v.zoom;
+    let ppp = v.ppp;
+    let ctx = v.ctx.clone();
+    let painter = v.painter.clone();
+    let comp = v.comp;
     // Frame.
     let scale = app.viewer_scale(zoom, ppp);
     if !app.playback.playing {
@@ -890,11 +330,21 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         let bg = comp.background;
         painter.rect_filled(comp_rect, 0.0, Color32::from_rgb((bg[0] * 255.0) as u8, (bg[1] * 255.0) as u8, (bg[2] * 255.0) as u8));
     }
-    let snap_project = app.session.project.clone();
-    let snap_expr = app.session.expr.clone();
-    let ectx = EvalCtx { project: &snap_project, comp_id: cid, comp: &comp, time, expr: snap_expr.as_deref(), footage: None };
+    v.time = time;
+}
+
+fn phase_guides(app: &mut EffectcraftApp, ectx: &EvalCtx, v: &mut Vw<'_>) {
+    let cid = v.cid;
+    let area = v.area;
+    let comp_rect = v.comp_rect;
+    let zoom = v.zoom;
+    let map = v.map;
+    let ctx = v.ctx.clone();
+    let comp_name = v.comp_name.clone();
+    let painter = v.painter.clone();
+    let comp = v.comp;
     // The frame (or snapshot) through Show Channel and exposure; ROI frames cover the region.
-    vt::draw_frame(app, &ctx, &painter, comp_rect, cid, &ectx);
+    vt::draw_frame(app, &ctx, &painter, comp_rect, cid, ectx);
     if app.ui.viewer.extended.is_some() {
         // The comp frame outlined over the extended render.
         painter.rect_stroke(comp_rect, 0.0, Stroke::new(1.0, Color32::from_gray(150)), StrokeKind::Outside);
@@ -980,17 +430,30 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
         app.auto.add("viewer.regionOfInterest", r, "Region of interest");
     }
+    v.overlays = overlays;
+}
+
+fn phase_layers(app: &mut EffectcraftApp, ui: &mut egui::Ui, ectx: &EvalCtx, v: &mut Vw<'_>) {
+    let t = v.t;
+    let zoom = v.zoom;
+    let cw = v.cw;
+    let ch = v.ch;
+    let map = v.map;
+    let time = v.time;
+    let ctx = v.ctx.clone();
+    let painter = v.painter.clone();
+    let mut handle_hits = std::mem::take(&mut v.handle_hits);
+    let mut axis_hits = std::mem::take(&mut v.axis_hits);
+    let mut vertex_hits = std::mem::take(&mut v.vertex_hits);
+    let mut vertex_marks = std::mem::take(&mut v.vertex_marks);
+    let mut key_hits = std::mem::take(&mut v.key_hits);
+    let mut motion_frames = std::mem::take(&mut v.motion_frames);
+    let mut paths = std::mem::take(&mut v.paths);
+    let comp = v.comp;
     // Overlays + interaction.
     let selected = app.session.state.selected_layers.clone();
     // Bounding-box handles: (layer, handle, screen point, its resize cursor).
-    let mut handle_hits: Vec<(LayerId, usize, Pos2, egui::CursorIcon)> = Vec::new();
     // 3D gizmo arrows: (layer, grabbable screen segment, position change per comp px in x and y).
-    let mut axis_hits: Vec<(LayerId, [Pos2; 2], [f64; 3], [f64; 3])> = Vec::new();
-    let mut vertex_hits: Vec<VertexHit> = Vec::new();
-    let mut vertex_marks: Vec<ov::VertexMark> = Vec::new();
-    let mut key_hits: Vec<ov::KeyHit> = Vec::new();
-    let mut motion_frames: Vec<ov::PathFrame> = Vec::new();
-    let mut paths: Vec<ov::PathInfo> = Vec::new();
     let sel_vertices = app.session.state.selected_vertices.clone();
     // Pen path in progress ends when the tool changes or its mask is gone; Esc / Enter also end
     // free transform.
@@ -1013,7 +476,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         for l in comp.layers.iter().filter(|l| {
             matches!(l.source, LayerSource::Null) && !selected.contains(&l.id) && l.is_active_at(time) && l.switches.video && (!any_solo || l.switches.solo)
         }) {
-            let outline = layer_outline(&ectx, l);
+            let outline = layer_outline(ectx, l);
             if outline.len() > 2 {
                 let col = if label_handles { t.label(l.label) } else { t.accent };
                 painter.add(egui::Shape::closed_line(outline.into_iter().map(|p| map.to_screen(p)).collect(), Stroke::new(1.0, col)));
@@ -1027,12 +490,12 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         for l in comp.layers.iter().filter(|l| selected.contains(&l.id) && l.is_active_at(time) && (l.switches.video || l.source.is_av())) {
             let col = if label_handles { t.label(l.label) } else { t.accent };
             // Motion path of animated position (keyframes and spatial tangents are draggable).
-            ov::motion_path(app, &painter, &map, &ectx, l, col, &mut key_hits, &mut motion_frames);
+            ov::motion_path(app, &painter, &map, ectx, l, col, &mut key_hits, &mut motion_frames);
             // Masks and shape paths.
             if app.ui.viewer.show_masks {
                 let pen = ui.data(|d| d.get_temp::<(LayerId, u64)>(pen_id()));
                 let hover = ui.input(|i| i.pointer.hover_pos());
-                ov::draw_paths(app, &painter, &map, &ectx, l, col, &sel_vertices, pen, hover, &mut vertex_hits, &mut vertex_marks, &mut paths);
+                ov::draw_paths(app, &painter, &map, ectx, l, col, &sel_vertices, pen, hover, &mut vertex_hits, &mut vertex_marks, &mut paths);
             }
             // Settings ▸ Previews ▸ Show Internal Wireframes: outlines of the layers inside a
             // selected collapsed precomp.
@@ -1041,7 +504,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 && let effectcraft_engine::project::LayerSource::Comp { item } = &l.source
                 && let Some(nc) = app.session.project.comp(*item)
             {
-                let (outer, _) = l2c(&ectx, l);
+                let (outer, _) = l2c(ectx, l);
                 let nctx = EvalCtx::new(&app.session.project, *item, nc, ectx.nested_time(l));
                 for nl in nc.layers.iter().filter(|nl| nl.is_active_at(nctx.time) && !nl.is_3d()) {
                     if let Some((_, q, _)) = layer_quad(&nctx, nl) {
@@ -1064,9 +527,9 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             if editing_path {
                 continue;
             }
-            let Some((m, q, _)) = layer_quad(&ectx, l) else {
+            let Some((m, q, _)) = layer_quad(ectx, l) else {
                 // A 3D layer reaching past the camera: the part of its box in front of it.
-                let outline = layer_outline(&ectx, l);
+                let outline = layer_outline(ectx, l);
                 if outline.len() > 2 {
                     painter.add(egui::Shape::closed_line(outline.iter().map(|p| map.to_screen(*p)).collect(), Stroke::new(1.0, col)));
                     continue;
@@ -1101,10 +564,10 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 // 3D axis gizmo.
                 if l.is_3d() {
                     let w = ectx.world_matrix(l);
-                    let pc = cam_state(&ectx).projection(cw as f64, ch as f64) * w;
+                    let pc = cam_state(ectx).projection(cw as f64, ch as f64) * w;
                     let a3 = effectcraft_engine::geom::vec3(a[0], a[1], a[2]);
                     let len = 60.0 / zoom as f64;
-                    let pinv = parent_world_inverse(&ectx, l);
+                    let pinv = parent_world_inverse(ectx, l);
                     for (axis, col, name) in [
                         (effectcraft_engine::geom::vec3(len, 0.0, 0.0), Color32::from_rgb(0xe0, 0x50, 0x50), "x"),
                         (effectcraft_engine::geom::vec3(0.0, len, 0.0), Color32::from_rgb(0x60, 0xd0, 0x60), "y"),
@@ -1133,7 +596,31 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
         }
     }
+    v.handle_hits = handle_hits;
+    v.axis_hits = axis_hits;
+    v.vertex_hits = vertex_hits;
+    v.vertex_marks = vertex_marks;
+    v.key_hits = key_hits;
+    v.motion_frames = motion_frames;
+    v.paths = paths;
+    v.selected = selected;
+    v.sel_vertices = sel_vertices;
+}
 
+fn phase_scene(app: &mut EffectcraftApp, ectx: &EvalCtx, v: &mut Vw<'_>) {
+    let t = v.t;
+    let cid = v.cid;
+    let area = v.area;
+    let comp_rect = v.comp_rect;
+    let cw = v.cw;
+    let ch = v.ch;
+    let map = v.map;
+    let time = v.time;
+    let painter = v.painter.clone();
+    let selected = v.selected.clone();
+    let vertex_marks = std::mem::take(&mut v.vertex_marks);
+    let mut track_hits = std::mem::take(&mut v.track_hits);
+    let comp = v.comp;
     // Path points last, over the boxes' handles (#1042).
     ov::draw_vertex_marks(&painter, &vertex_marks, app.session.prefs.general.path_point_size as f32 + 1.0);
 
@@ -1142,7 +629,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     let has_3d = comp.layers.iter().any(|l| l.is_3d() && l.is_active_at(time));
     if has_3d && app.session.prefs.three_d.extended_viewer {
         for l in comp.layers.iter().filter(|l| l.is_3d() && l.is_active_at(time) && l.has_video()) {
-            let q = layer_outline(&ectx, l);
+            let q = layer_outline(ectx, l);
             if q.len() > 2 {
                 let sq: Vec<Pos2> = q.iter().map(|p| map.to_screen(*p)).collect();
                 let outside = sq.iter().any(|p| !comp_rect.contains(*p));
@@ -1153,7 +640,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         }
     }
     if has_3d && app.session.prefs.three_d.show_reference_axes {
-        let pc = cam_state(&ectx).projection(cw as f64, ch as f64);
+        let pc = cam_state(ectx).projection(cw as f64, ch as f64);
         let o3 = effectcraft_engine::geom::vec3(cw as f64 / 2.0, ch as f64 / 2.0, 0.0);
         let o = pc.apply(o3);
         let corner = pos2(area.min.x + 34.0, area.max.y - 34.0);
@@ -1172,7 +659,6 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
 
     // Track points of the current track (Tracker panel) on its layer, while that layer is selected.
-    let mut track_hits = vec![];
     let track_cur = super::tracker::viewer_track(app);
     if app.layer_controls_visible()
         && let Some((tl, tu)) = track_cur
@@ -1180,7 +666,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         && let Some(layer) = comp.layer(tl)
         && layer.is_active_at(time)
     {
-        let (m, _) = l2c(&ectx, layer);
+        let (m, _) = l2c(ectx, layer);
         track_hits = super::tracker::draw_overlay(app, &painter, &map, &m, layer, tu, time);
     }
 
@@ -1192,7 +678,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         && let Some(layer) = comp.layer(wl)
         && layer.is_active_at(time)
     {
-        let (m, _) = l2c(&ectx, layer);
+        let (m, _) = l2c(ectx, layer);
         let (w, h) = effectcraft_engine::render::source_size(&app.session.project, layer);
         let c = m.apply(effectcraft_engine::geom::vec2(w as f64 / 2.0, h as f64 / 2.0));
         let at = map.to_screen([c.x, c.y]);
@@ -1214,7 +700,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         if notices >= 3 {
             break;
         }
-        let (m, _) = l2c(&ectx, layer);
+        let (m, _) = l2c(ectx, layer);
         let (w, h) = effectcraft_engine::render::source_size(&app.session.project, layer);
         let c = m.apply(effectcraft_engine::geom::vec2(w as f64 / 2.0, h as f64 / 2.0));
         let at = map.to_screen([c.x, c.y]);
@@ -1227,14 +713,32 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         app.auto.add(&format!("viewer.footageProblem.{}", layer.id.0), r, &text);
         notices += 1;
     }
+    v.vertex_marks = vertex_marks;
+    v.track_hits = track_hits;
+    v.track_cur = track_cur;
+    v.has_3d = has_3d;
+}
 
+fn phase_rigs(app: &mut EffectcraftApp, ui: &mut egui::Ui, ectx: &EvalCtx, v: &mut Vw<'_>) {
+    let t = v.t;
+    let cid = v.cid;
+    let area = v.area;
+    let map = v.map;
+    let time = v.time;
+    let ctx = v.ctx.clone();
+    let painter = v.painter.clone();
+    let selected = v.selected.clone();
+    let paths = std::mem::take(&mut v.paths);
+    let mut pin_hits = std::mem::take(&mut v.pin_hits);
+    let mut puppet_layers = std::mem::take(&mut v.puppet_layers);
+    let comp = v.comp;
     // Free transform box of a path (double-click a path with the Selection tool).
     let ft = ov::draw_free_transform(app, &ctx, &painter, &map, &paths);
 
     // Cameras and lights (wireframes) and the 3D view name.
     if comp.has_3d() {
         let through_active = VIEW_CAM.with(|c| c.get()).is_none();
-        draw_rigs(app, &painter, &map, &ectx, &selected, cam_state(&ectx), through_active, None);
+        draw_rigs(app, &painter, &map, ectx, &selected, cam_state(ectx), through_active, None);
         let view = app.session.state.views3d.get(&cid).map(|v| v.current).unwrap_or_default();
         let label = match (view, comp.active_camera(time)) {
             (View3D::ActiveCamera, Some(c)) => format!("Active Camera ({})", c.name),
@@ -1244,10 +748,8 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     }
 
     // Puppet pins and meshes of the selected layers (Puppet tools).
-    let mut pin_hits: Vec<super::puppet_tool::PinHit> = vec![];
     // The selected layers with a Puppet effect, top of the stack first (the layers the Puppet
     // tools work on).
-    let mut puppet_layers: Vec<(&Layer, super::puppet_tool::Overlay)> = vec![];
     if app.ui.tool.puppet_kind().is_some() {
         let sel_props: Vec<u64> = app.session.state.selected_props.iter().map(|(_, u)| *u).collect();
         for lid in &selected {
@@ -1255,7 +757,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 && let Some(ov) = super::puppet_tool::overlay(app, &ctx, cid, l, time)
             {
                 let hover = ui.input(|i| i.pointer.hover_pos());
-                pin_hits.extend(super::puppet_tool::draw(&painter, &map, &ectx, l, &ov, app.session.state.puppet.show_mesh, &sel_props, hover));
+                pin_hits.extend(super::puppet_tool::draw(&painter, &map, ectx, l, &ov, app.session.state.puppet.show_mesh, &sel_props, hover));
                 puppet_layers.push((l, ov));
             }
         }
@@ -1269,17 +771,21 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
         }
     }
-    // The layer a Puppet tool press works on: while selected layers are rigged, only those
-    // ([`super::puppet_tool::target`]); otherwise the layer under the pointer, selected.
-    let puppet_layer = |app: &mut EffectcraftApp, cpt: [f64; 2]| -> Option<LayerId> {
-        if puppet_layers.is_empty() {
-            return pick(app, &ectx, cpt, false);
-        }
-        super::puppet_tool::target(&ectx, &puppet_layers, cpt, |l| layers_at(&ectx, cpt).any(|h| h.id == l.id))
-    };
+    v.paths = paths;
+    v.pin_hits = pin_hits;
+    v.puppet_layers = puppet_layers;
+    v.ft = ft;
+}
 
+fn phase_menu(app: &mut EffectcraftApp, ui: &mut egui::Ui, ectx: &EvalCtx, v: &mut Vw<'_>) -> egui::Response {
+    let cid = v.cid;
+    let area = v.area;
+    let map = v.map;
+    let ctx = v.ctx.clone();
+    let painter = v.painter.clone();
+    let comp = v.comp;
     // Project items, files and effects dropped on the viewer.
-    super::viewer_drop::show(app, ui, &painter, &map, &ectx);
+    super::viewer_drop::show(app, ui, &painter, &map, ectx);
 
     // Interaction.
     let resp = ui.interact(area, egui::Id::unique("viewer-interact"), Sense::click_and_drag());
@@ -1289,9 +795,9 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     {
         // Picking an already selected layer preserves the group; an unselected hit
         // becomes the target, using the same visible/unlocked hit test as left-click.
-        pick(app, &ectx, map.to_comp(pos), false);
+        pick(app, ectx, map.to_comp(pos), false);
         let point = map.to_comp(pos);
-        let hits: Vec<(u64, String)> = layers_at(&ectx, point).map(|l| (l.id.0, l.name.clone())).collect();
+        let hits: Vec<(u64, String)> = layers_at(ectx, point).map(|l| (l.id.0, l.name.clone())).collect();
         ui.data_mut(|d| d.insert_temp(menu_hits_id, hits));
     }
     let context_layers: Vec<u64> =
@@ -1346,6 +852,26 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             app.ui.status = e;
         }
     }
+    resp
+}
+
+fn phase_hover(app: &mut EffectcraftApp, ui: &mut egui::Ui, ectx: &EvalCtx, resp: &egui::Response, v: &mut Vw<'_>) {
+    let area = v.area;
+    let zoom = v.zoom;
+    let cw = v.cw;
+    let ch = v.ch;
+    let map = v.map;
+    let ctx = v.ctx.clone();
+    let painter = v.painter.clone();
+    let handle_hits = std::mem::take(&mut v.handle_hits);
+    let axis_hits = std::mem::take(&mut v.axis_hits);
+    let vertex_hits = std::mem::take(&mut v.vertex_hits);
+    let key_hits = std::mem::take(&mut v.key_hits);
+    let motion_frames = std::mem::take(&mut v.motion_frames);
+    let paths = std::mem::take(&mut v.paths);
+    let track_hits = std::mem::take(&mut v.track_hits);
+    let pin_hits = std::mem::take(&mut v.pin_hits);
+    let comp = v.comp;
     // Path vertices and tangent handles take the press before the bounding-box handles (#1042).
     let vertex_at = |pos: Pos2, tangents: bool| -> Option<VertexHit> {
         let reach = vertex_grab_radius(pos, handle_hits.iter().map(|(_, _, h, _)| *h));
@@ -1380,7 +906,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 // The tool draws its own crosshair (and the layer it would matte) while no box
                 // is being dragged.
                 if ui.data(|d| d.get_temp::<Gesture>(egui::Id::unique("viewer-gesture"))).is_none() {
-                    super::object_matte_tool::hover(app, &painter, &map, &ectx, hp);
+                    super::object_matte_tool::hover(app, &painter, &map, ectx, hp);
                 }
                 egui::CursorIcon::None
             }
@@ -1394,7 +920,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             _ => {
                 if super::tracker::hit_at(&track_hits, hp).is_some() || key_hits.iter().any(|h| h.pos.distance(hp) < 6.0) {
                     egui::CursorIcon::Move
-                } else if let Some((_, vertical)) = vt::guide_at(app, &comp, &map, hp) {
+                } else if let Some((_, vertical)) = vt::guide_at(app, comp, &map, hp) {
                     if vertical { egui::CursorIcon::ResizeHorizontal } else { egui::CursorIcon::ResizeVertical }
                 } else if vertex_at(hp, true).or_else(|| vertex_at(hp, false)).is_some() {
                     // A path point under a box handle is grabbed first: no resize cursor.
@@ -1424,6 +950,24 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     } else {
         app.pointer_comp = None;
     }
+    v.handle_hits = handle_hits;
+    v.axis_hits = axis_hits;
+    v.vertex_hits = vertex_hits;
+    v.key_hits = key_hits;
+    v.motion_frames = motion_frames;
+    v.paths = paths;
+    v.track_hits = track_hits;
+    v.pin_hits = pin_hits;
+    v.gid = gid;
+}
+
+fn phase_press(app: &mut EffectcraftApp, ui: &mut egui::Ui, ectx: &EvalCtx, resp: &egui::Response, v: &mut Vw<'_>) {
+    let map = v.map;
+    let ctx = v.ctx.clone();
+    let painter = v.painter.clone();
+    let key_hits = std::mem::take(&mut v.key_hits);
+    let motion_frames = std::mem::take(&mut v.motion_frames);
+    let paths = std::mem::take(&mut v.paths);
     app.ui.viewer.interacting = resp.dragged();
     let mods = ui.input(|i| i.modifiers);
     let space_pan = super::space_hand(&ctx);
@@ -1435,7 +979,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         && ui.input(|i| i.pointer.primary_pressed())
         && let Some(pos) = ui.input(|i| i.pointer.press_origin())
     {
-        pen_press(app, ui, &ectx, &map, &paths, ov::motion_frame_at(&motion_frames, &key_hits, pos), pos, mods);
+        pen_press(app, ui, ectx, &map, &paths, ov::motion_frame_at(&motion_frames, &key_hits, pos), pos, mods);
     }
     // A pen click (press + release without a drag) ends its tangent gesture on release.
     if ui.input(|i| i.pointer.primary_released())
@@ -1445,7 +989,45 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         ui.data_mut(|d| d.remove::<Gesture>(egui::Id::unique("viewer-gesture")));
     }
     // On-canvas text editing (Type tool, double-click a text layer) owns its clicks and drags.
-    let text_owns = super::viewer_text::hook(app, ui, &painter, &map, &ectx, &resp, space_pan);
+    let text_owns = super::viewer_text::hook(app, ui, &painter, &map, ectx, resp, space_pan);
+    v.key_hits = key_hits;
+    v.motion_frames = motion_frames;
+    v.paths = paths;
+    v.mods = mods;
+    v.space_pan = space_pan;
+    v.text_owns = text_owns;
+}
+
+fn phase_dragstart(app: &mut EffectcraftApp, ui: &mut egui::Ui, ectx: &EvalCtx, resp: &egui::Response, v: &mut Vw<'_>) {
+    let comp_rect = v.comp_rect;
+    let zoom = v.zoom;
+    let map = v.map;
+    let time = v.time;
+    let mods = v.mods;
+    let space_pan = v.space_pan;
+    let text_owns = v.text_owns;
+    let gid = v.gid;
+    let track_cur = v.track_cur;
+    let ft = std::mem::take(&mut v.ft);
+    let handle_hits = std::mem::take(&mut v.handle_hits);
+    let axis_hits = std::mem::take(&mut v.axis_hits);
+    let vertex_hits = std::mem::take(&mut v.vertex_hits);
+    let key_hits = std::mem::take(&mut v.key_hits);
+    let paths = std::mem::take(&mut v.paths);
+    let track_hits = std::mem::take(&mut v.track_hits);
+    let pin_hits = std::mem::take(&mut v.pin_hits);
+    let puppet_layers = std::mem::take(&mut v.puppet_layers);
+    let comp = v.comp;
+    let vertex_at = |pos: Pos2, tangents: bool| -> Option<VertexHit> {
+        let reach = vertex_grab_radius(pos, handle_hits.iter().map(|(_, _, h, _)| *h));
+        vertex_hits.iter().rev().filter(|h| h.tangent.is_some() == tangents).find(|h| h.pos.distance(pos) < reach).copied()
+    };
+    let puppet_layer = |app: &mut EffectcraftApp, cpt: [f64; 2]| -> Option<LayerId> {
+        if puppet_layers.is_empty() {
+            return pick(app, ectx, cpt, false);
+        }
+        super::puppet_tool::target(ectx, &puppet_layers, cpt, |l| layers_at(ectx, cpt).any(|h| h.id == l.id))
+    };
     if resp.drag_started()
         && !text_owns
         && let Some(pos) = resp.interact_pointer_pos()
@@ -1465,8 +1047,8 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             Tool::Selection if key_hits.iter().any(|h| h.pos.distance(press) < 6.0) => {
                 ov::begin_key_drag(app, &key_hits, press, map.to_comp(press), mods.shift).map(Gesture::Overlay)
             }
-            Tool::Selection if vt::guide_at(app, &comp, &map, press).is_some() => {
-                vt::guide_at(app, &comp, &map, press).map(|(index, vertical)| Gesture::Overlay(ov::Drag::Guide { index, vertical }))
+            Tool::Selection if vt::guide_at(app, comp, &map, press).is_some() => {
+                vt::guide_at(app, comp, &map, press).map(|(index, vertical)| Gesture::Overlay(ov::Drag::Guide { index, vertical }))
             }
             // Alt-drag a vertex with the Selection tool (or drag one with Convert Vertex): pull
             // new tangents out of it.
@@ -1476,9 +1058,9 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                     Gesture::Pen { layer: h.layer, mask: h.mask, index: h.index, vertex: h.vertex, inv, press }
                 })
             }
-            Tool::MaskFeather => ov::begin_feather(app, &ectx, &paths, &map, press).map(Gesture::Overlay),
-            Tool::Rotate => pick(app, &ectx, cpt, mods.shift).map(|l| {
-                let others = selected_others(app, &comp, l).into_iter().filter_map(|o| Some((o.id, ectx.f(o, o.transform()?, "rotation", 0.0)))).collect();
+            Tool::MaskFeather => ov::begin_feather(app, ectx, &paths, &map, press).map(Gesture::Overlay),
+            Tool::Rotate => pick(app, ectx, cpt, mods.shift).map(|l| {
+                let others = selected_others(app, comp, l).into_iter().filter_map(|o| Some((o.id, ectx.f(o, o.transform()?, "rotation", 0.0)))).collect();
                 let layer = comp.layer(l).cloned();
                 let center = layer
                     .as_ref()
@@ -1495,10 +1077,10 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                     others,
                 }
             }),
-            Tool::PanBehind => pick(app, &ectx, cpt, false).and_then(|l| {
+            Tool::PanBehind => pick(app, ectx, cpt, false).and_then(|l| {
                 let layer = comp.layer(l)?;
                 let tr = layer.transform()?;
-                let (l2c, _) = l2c(&ectx, layer);
+                let (l2c, _) = l2c(ectx, layer);
                 let l2p = ectx.local_matrix(layer);
                 let l2p = Mat3([[l2p.0[0][0], l2p.0[0][1], 0.0], [l2p.0[1][0], l2p.0[1][1], 0.0], [0.0, 0.0, 1.0]]);
                 Some(Gesture::Anchor {
@@ -1509,7 +1091,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                     start: map.to_comp(press),
                     inv: l2c.inverse().unwrap_or(Mat3::IDENTITY),
                     l2p,
-                    own: effectcraft_engine::viewer::layer_targets(&ectx, layer, false, app.session.state.snap_features),
+                    own: effectcraft_engine::viewer::layer_targets(ectx, layer, false, app.session.state.snap_features),
                     anchor_only: mods.alt,
                 })
             }),
@@ -1535,7 +1117,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                     PinPart::Center => {}
                 }
                 let l = comp.layer(h.layer)?;
-                let inv = fx2c(&ectx, l).inverse()?;
+                let inv = fx2c(ectx, l).inverse()?;
                 if mods.command {
                     let lp = inv.apply(gv2(cpt[0], cpt[1]));
                     let began = ui.input(|i| i.time);
@@ -1555,7 +1137,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 let hit = super::tracker::hit_at(&track_hits, press);
                 track_cur.zip(hit).and_then(|((tl, tu), hit)| {
                     let layer = comp.layer(tl)?;
-                    let (m, _) = l2c(&ectx, layer);
+                    let (m, _) = l2c(ectx, layer);
                     super::tracker::begin_drag(layer, tu, time, &m, hit, map.to_comp(press)).map(|drag| Gesture::Track { layer: tl, tracker: tu, drag })
                 })
             }
@@ -1595,11 +1177,11 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                     let layer = comp.layer(lid).cloned();
                     layer.and_then(|layer| {
                         let tr = layer.transform()?;
-                        let (l2c, _) = l2c(&ectx, &layer);
+                        let (l2c, _) = l2c(ectx, &layer);
                         let inv = l2c.inverse()?;
                         let a = ectx.v3(&layer, tr, "anchor", [0.0; 3]);
                         let lp = inv.apply(gv2(cpt[0], cpt[1]));
-                        let hp = handle_point(effectcraft_engine::render::content_bounds(&ectx, &layer)?, hi);
+                        let hp = handle_point(effectcraft_engine::render::content_bounds(ectx, &layer)?, hi);
                         Some(Gesture::Scale {
                             layer: lid,
                             start_scale: ectx.v3(&layer, tr, "scale", [100.0; 3]),
@@ -1609,13 +1191,13 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                             axes: handle_axes(hi),
                             l2c,
                             inv,
-                            others: selected_others(app, &comp, lid)
+                            others: selected_others(app, comp, lid)
                                 .into_iter()
                                 .filter_map(|o| Some((o.id, ectx.v3(o, o.transform()?, "scale", [100.0; 3]))))
                                 .collect(),
                         })
                     })
-                } else if let Some(l) = pick(app, &ectx, cpt, mods.shift) {
+                } else if let Some(l) = pick(app, ectx, cpt, mods.shift) {
                     let layers: Vec<(LayerId, [f64; 3], [f64; 3], [f64; 3])> = app
                         .session
                         .state
@@ -1625,12 +1207,12 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                         .filter(|l| !l.switches.locked)
                         .filter_map(|l| {
                             let p0 = ectx.v3(l, l.transform()?, "position", [0.0; 3]);
-                            let (ax, ay) = drag_axes(&ectx, l);
+                            let (ax, ay) = drag_axes(ectx, l);
                             Some((l.id, p0, ax, ay))
                         })
                         .collect();
                     // Snap the grabbed layer's feature nearest the pointer (AE's snap handle).
-                    let snap_src = comp.layer(l).map(|layer| effectcraft_engine::viewer::layer_features(&ectx, layer)).and_then(|f| {
+                    let snap_src = comp.layer(l).map(|layer| effectcraft_engine::viewer::layer_features(ectx, layer)).and_then(|f| {
                         let c = map.to_comp(press);
                         f.into_iter().min_by(|a, b| {
                             let da = (a[0] - c[0]).powi(2) + (a[1] - c[1]).powi(2);
@@ -1659,6 +1241,25 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             ui.data_mut(|d| d.insert_temp(gid, g));
         }
     }
+    v.ft = ft;
+    v.handle_hits = handle_hits;
+    v.axis_hits = axis_hits;
+    v.vertex_hits = vertex_hits;
+    v.key_hits = key_hits;
+    v.paths = paths;
+    v.track_hits = track_hits;
+    v.pin_hits = pin_hits;
+    v.puppet_layers = puppet_layers;
+}
+
+fn phase_drag(app: &mut EffectcraftApp, ui: &mut egui::Ui, ectx: &EvalCtx, resp: &egui::Response, v: &mut Vw<'_>) {
+    let t = v.t;
+    let zoom = v.zoom;
+    let map = v.map;
+    let mods = v.mods;
+    let gid = v.gid;
+    let ctx = v.ctx.clone();
+    let painter = v.painter.clone();
     let gesture: Option<Gesture> = ui.data(|d| d.get_temp(gid));
     if let (Some(g), Some(pos)) = (gesture.clone(), resp.interact_pointer_pos()) {
         let cpt = map.to_comp(pos);
@@ -1675,7 +1276,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 let mut d = one_axis([cpt[0] - start[0], cpt[1] - start[1]], mods.shift);
                 if let Some(src) = snap_src {
                     let ids: Vec<LayerId> = layers.iter().map(|x| x.0).collect();
-                    let c = vt::snap(app, &ctx, &ectx, &map, &ids, &[[src[0] + d[0], src[1] + d[1]]], mods);
+                    let c = vt::snap(app, &ctx, ectx, &map, &ids, &[[src[0] + d[0], src[1] + d[1]]], mods);
                     d = [d[0] + c[0], d[1] + c[1]];
                     if vt::snapping_on(app, mods) {
                         vt::draw_handle(&painter, map.to_screen([src[0] + d[0], src[1] + d[1]]));
@@ -1692,7 +1293,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 let f = drag_ratio(start_local, [lp.x - anchor[0], lp.y - anchor[1]], axes, uniform);
                 // The handle snaps (to the comp's and other layers' edges, corners and centres),
                 // so a layer scales exactly to them, e.g. to the comp's size.
-                let f = snap_handle(f, handle, anchor, &l2c, axes, uniform, |p| vt::snap(app, &ctx, &ectx, &map, &[layer], &[p], mods));
+                let f = snap_handle(f, handle, anchor, &l2c, axes, uniform, |p| vt::snap(app, &ctx, ectx, &map, &[layer], &[p], mods));
                 for (lid, s0) in std::iter::once((layer, start_scale)).chain(others) {
                     let v = [s0[0] * f[0], s0[1] * f[1], s0[2]];
                     let _ = app.session.execute("prop.set", json!({"layer": lid.0, "path": "transform/scale", "value": v, "merge": merge}));
@@ -1718,7 +1319,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 let d = one_axis([cpt[0] - start[0], cpt[1] - start[1]], mods.shift);
                 let anchor_c = inv.inverse().map(|m| m.apply(gv2(start_anchor[0], start_anchor[1]))).unwrap_or(gv2(start[0], start[1]));
                 let want = [anchor_c.x + d[0], anchor_c.y + d[1]];
-                let sc = vt::snap_with(app, &ctx, &ectx, &map, &[layer], &[want], mods, &own);
+                let sc = vt::snap_with(app, &ctx, ectx, &map, &vt::SnapQuery { exclude: &[layer], sources: &[want], mods, extra: &own });
                 let a = inv.apply(gv2(start[0], start[1]));
                 let b = inv.apply(gv2(start[0] + d[0] + sc[0], start[1] + d[1] + sc[1]));
                 let dl = gv2(b.x - a.x, b.y - a.y);
@@ -1753,7 +1354,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             Gesture::Vertices { start, src, applied, inv, layer } => {
                 // The grabbed vertex snaps (to other layers' vertices and features, guides, grid).
                 let want = [cpt[0] - start[0], cpt[1] - start[1]];
-                let c = vt::snap(app, &ctx, &ectx, &map, &[layer], &[[src[0] + want[0], src[1] + want[1]]], mods);
+                let c = vt::snap(app, &ctx, ectx, &map, &[layer], &[[src[0] + want[0], src[1] + want[1]]], mods);
                 let total = [want[0] + c[0], want[1] + c[1]];
                 let d = inv.apply_vec(gv2(total[0] - applied[0], total[1] - applied[1]));
                 if d.x != 0.0 || d.y != 0.0 {
@@ -1772,7 +1373,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                     painter.rect_stroke(r, 0.0, Stroke::new(1.0, Color32::WHITE), StrokeKind::Middle);
                 }
                 d => {
-                    let mut snapper = |a: &EffectcraftApp, p: [f64; 2], l: LayerId| vt::snap(a, &ctx, &ectx, &map, &[l], &[p], mods);
+                    let mut snapper = |a: &EffectcraftApp, p: [f64; 2], l: LayerId| vt::snap(a, &ctx, ectx, &map, &[l], &[p], mods);
                     if let Some(nd) = ov::update(app, &d, cpt, pos, mods, &merge, zoom, &mut snapper) {
                         ui.data_mut(|dd| dd.insert_temp(gid, Gesture::Overlay(nd)));
                     }
@@ -1853,6 +1454,20 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
         }
     }
+    v.gesture = gesture;
+}
+
+fn phase_stopped(app: &mut EffectcraftApp, ui: &mut egui::Ui, ectx: &EvalCtx, resp: &egui::Response, v: &mut Vw<'_>) {
+    let area = v.area;
+    let comp_rect = v.comp_rect;
+    let map = v.map;
+    let time = v.time;
+    let mods = v.mods;
+    let gid = v.gid;
+    let vertex_hits = std::mem::take(&mut v.vertex_hits);
+    let pin_hits = std::mem::take(&mut v.pin_hits);
+    let gesture = v.gesture.clone();
+    let comp = v.comp;
     if resp.drag_stopped() {
         if let (Some(g), Some(pos)) = (gesture, resp.interact_pointer_pos()) {
             match g {
@@ -1886,7 +1501,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                     }
                 }
                 Gesture::PuppetPin { layer, pin, .. } => super::puppet_tool::reveal_pin(app, layer, pin),
-                Gesture::ObjectMatteBox { start } => super::object_matte_tool::apply(app, &ectx, &map, start, Some(pos), mods.shift),
+                Gesture::ObjectMatteBox { start } => super::object_matte_tool::apply(app, ectx, &map, start, Some(pos), mods.shift),
                 Gesture::Create { tool, start } => {
                     let end = map.to_comp(pos);
                     create_shape(app, tool, start, end, mods);
@@ -1919,8 +1534,8 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 Gesture::Marquee { start } => {
                     let a = map.to_comp(start);
                     let b = map.to_comp(pos);
-                    let hits: Vec<u64> = selectable_layers(&comp, time)
-                        .filter(|l| layer_quad(&ectx, l).is_some_and(|(_, q, _)| quad_intersects_box(&q, a, b)))
+                    let hits: Vec<u64> = selectable_layers(comp, time)
+                        .filter(|l| layer_quad(ectx, l).is_some_and(|(_, q, _)| quad_intersects_box(&q, a, b)))
                         .map(|l| l.id.0)
                         .collect();
                     let _ = app.session.execute("layer.select", json!({"layers": hits, "toggle": mods.shift}));
@@ -1934,6 +1549,38 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             d.insert_temp(egui::Id::unique("viewer-drag-n"), n + 1);
         });
     }
+    v.vertex_hits = vertex_hits;
+    v.pin_hits = pin_hits;
+}
+
+fn phase_clicked(app: &mut EffectcraftApp, ectx: &EvalCtx, resp: &egui::Response, v: &mut Vw<'_>) {
+    let area = v.area;
+    let zoom = v.zoom;
+    let cw = v.cw;
+    let ch = v.ch;
+    let map = v.map;
+    let mods = v.mods;
+    let text_owns = v.text_owns;
+    let ctx = v.ctx.clone();
+    let ft = std::mem::take(&mut v.ft);
+    let handle_hits = std::mem::take(&mut v.handle_hits);
+    let vertex_hits = std::mem::take(&mut v.vertex_hits);
+    let key_hits = std::mem::take(&mut v.key_hits);
+    let motion_frames = std::mem::take(&mut v.motion_frames);
+    let paths = std::mem::take(&mut v.paths);
+    let pin_hits = std::mem::take(&mut v.pin_hits);
+    let puppet_layers = std::mem::take(&mut v.puppet_layers);
+    let comp = v.comp;
+    let vertex_at = |pos: Pos2, tangents: bool| -> Option<VertexHit> {
+        let reach = vertex_grab_radius(pos, handle_hits.iter().map(|(_, _, h, _)| *h));
+        vertex_hits.iter().rev().filter(|h| h.tangent.is_some() == tangents).find(|h| h.pos.distance(pos) < reach).copied()
+    };
+    let puppet_layer = |app: &mut EffectcraftApp, cpt: [f64; 2]| -> Option<LayerId> {
+        if puppet_layers.is_empty() {
+            return pick(app, ectx, cpt, false);
+        }
+        super::puppet_tool::target(ectx, &puppet_layers, cpt, |l| layers_at(ectx, cpt).any(|h| h.id == l.id))
+    };
     if resp.clicked()
         && !text_owns
         && let Some(pos) = resp.interact_pointer_pos()
@@ -1990,13 +1637,13 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
                 // Clicking away from the free-transform box ends it.
                 ov::end_free_transform(&ctx);
             }
-            Tool::ObjectMatte => super::object_matte_tool::apply(app, &ectx, &map, pos, None, mods.shift),
+            Tool::ObjectMatte => super::object_matte_tool::apply(app, ectx, &map, pos, None, mods.shift),
             t if t.puppet_kind().is_some() => {
                 if let Some((h, _)) = super::puppet_tool::hit(&pin_hits, pos) {
                     // Click selects the pin; Shift-click adds or removes it.
                     let _ = app.session.execute("puppet.selectPins", json!({"layer": h.layer.0, "pins": [h.pin], "toggle": mods.shift}));
                 } else if let Some(l) = puppet_layer(app, cpt).and_then(|l| comp.layer(l))
-                    && let Some(inv) = fx2c(&ectx, l).inverse()
+                    && let Some(inv) = fx2c(ectx, l).inverse()
                 {
                     let lp = inv.apply(gv2(cpt[0], cpt[1]));
                     match app.session.execute("puppet.addPin", json!({"layer": l.id.0, "kind": t.puppet_kind(), "position": [lp.x, lp.y]})) {
@@ -2017,13 +1664,13 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
             // The Roto Brush paints in the Layer panel only: select as usual and say so.
             rt if rt.roto_kind(false).is_some() => {
-                if pick(app, &ectx, cpt, mods.shift).is_none() {
+                if pick(app, ectx, cpt, mods.shift).is_none() {
                     let _ = app.session.execute("edit.deselectAll", json!({}));
                 }
                 app.ui.status = crate::i18n::tr(ROTO_HINT).to_string();
             }
             _ => {
-                if pick(app, &ectx, cpt, mods.shift).is_none() {
+                if pick(app, ectx, cpt, mods.shift).is_none() {
                     let _ = app.session.execute("edit.deselectAll", json!({}));
                 } else if !mods.shift && !app.session.state.selected_vertices.is_empty() && ov::segment_at(&paths, &map, pos, 6.0).is_none() {
                     // A click away from the paths, even on their layer, deselects the mask
@@ -2033,6 +1680,28 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
         }
     }
+    v.ft = ft;
+    v.handle_hits = handle_hits;
+    v.vertex_hits = vertex_hits;
+    v.key_hits = key_hits;
+    v.motion_frames = motion_frames;
+    v.paths = paths;
+    v.pin_hits = pin_hits;
+    v.puppet_layers = puppet_layers;
+}
+
+fn phase_dblclick(app: &mut EffectcraftApp, ectx: &EvalCtx, resp: &egui::Response, v: &mut Vw<'_>) {
+    let map = v.map;
+    let text_owns = v.text_owns;
+    let ctx = v.ctx.clone();
+    let handle_hits = std::mem::take(&mut v.handle_hits);
+    let vertex_hits = std::mem::take(&mut v.vertex_hits);
+    let paths = std::mem::take(&mut v.paths);
+    let comp = v.comp;
+    let vertex_at = |pos: Pos2, tangents: bool| -> Option<VertexHit> {
+        let reach = vertex_grab_radius(pos, handle_hits.iter().map(|(_, _, h, _)| *h));
+        vertex_hits.iter().rev().filter(|h| h.tangent.is_some() == tangents).find(|h| h.pos.distance(pos) < reach).copied()
+    };
     if resp.double_clicked()
         && !text_owns
         && app.ui.tool == Tool::Selection
@@ -2054,7 +1723,7 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
     {
         let cpt = map.to_comp(pos);
         let roto = app.ui.tool.roto_kind(false).is_some();
-        if let Some(l) = pick(app, &ectx, cpt, false).and_then(|l| comp.layer(l)) {
+        if let Some(l) = pick(app, ectx, cpt, false).and_then(|l| comp.layer(l)) {
             match &l.source {
                 effectcraft_engine::project::LayerSource::Comp { item } => app.session.open_comp(*item),
                 // With a Roto Brush tool, double-clicking a layer opens it in the Layer panel,
@@ -2070,15 +1739,34 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
             }
         }
     }
+    v.handle_hits = handle_hits;
+    v.vertex_hits = vertex_hits;
+    v.paths = paths;
+}
+
+fn phase_tail(app: &mut EffectcraftApp, ui: &mut egui::Ui, ectx: &EvalCtx, v: &mut Vw<'_>) {
+    let t = v.t;
+    let cid = v.cid;
+    let bar = v.bar;
+    let err_bar = v.err_bar;
+    let err_h = v.err_h;
+    let area = v.area;
+    let outer = v.outer;
+    let zoom = v.zoom;
+    let map = v.map;
+    let time = v.time;
+    let ctx = v.ctx.clone();
+    let painter = v.painter.clone();
+    let comp = v.comp;
     // 3D Camera Tracker points, targets and their menu (on top of the viewer's gestures while
     // the effect is selected), and its analysis banner.
-    super::camera_tracker_ui::viewer_hook(app, ui, &painter, &map, &ectx, &|c, l| l2c(c, l).0);
+    super::camera_tracker_ui::viewer_hook(app, ui, &painter, &map, ectx, &|c, l| l2c(c, l).0);
     // Effect point controls and crosshair/eyedropper picks (on top of the viewer's gestures).
-    crate::panels::effect_controls::viewer_hook(app, ui, &painter, &map, &ectx, &|c, l| l2c(c, l).0);
+    crate::panels::effect_controls::viewer_hook(app, ui, &painter, &map, ectx, &|c, l| l2c(c, l).0);
     // Selected shape gradients' start and end points (#612).
-    crate::panels::gradient_handles::viewer_hook(app, ui, &painter, &map, &ectx, &|c, l| l2c(c, l).0);
+    crate::panels::gradient_handles::viewer_hook(app, ui, &painter, &map, ectx, &|c, l| l2c(c, l).0);
     // Selected text Range Selectors' Start and End bars (#1011).
-    crate::panels::text_range_handles::viewer_hook(app, ui, &painter, &map, &ectx, &|c, l| l2c(c, l).0);
+    crate::panels::text_range_handles::viewer_hook(app, ui, &painter, &map, ectx, &|c, l| l2c(c, l).0);
 
     // Status chips (render time / caching).
     if app.playback.playing && app.playback.waiting {
@@ -2093,850 +1781,39 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
         ui.ctx().data_mut(|d| d.insert_temp(egui::Id::unique("viewer-video-off-chip"), r));
     }
 
-    vt::draw_snap(&ctx, &painter, &map, &ectx);
+    vt::draw_snap(&ctx, &painter, &map, ectx);
     vt::rulers(app, ui, &map, outer, area);
-    vt::bottom_bar(app, ui, bar, zoom, time, &comp);
+    vt::bottom_bar(app, ui, bar, zoom, time, comp);
     if err_h > 0.0 {
         super::expr_bar::draw(app, ui, err_bar, cid);
     }
 }
-
-/// The position change per comp pixel of drag (x, y) that moves a layer by `dir` when the
-/// pointer covers the axis' on-screen vector `s` (comp px); drag across the axis is ignored.
-fn axis_drag(dir: [f64; 3], s: [f64; 2]) -> ([f64; 3], [f64; 3]) {
-    let n = (s[0] * s[0] + s[1] * s[1]).max(1e-12);
-    (dir.map(|v| v * s[0] / n), dir.map(|v| v * s[1] / n))
-}
-
-/// The gizmo arrow under screen point `p`.
-fn axis_at(hits: &[(LayerId, [Pos2; 2], [f64; 3], [f64; 3])], p: Pos2) -> Option<(LayerId, [Pos2; 2], [f64; 3], [f64; 3])> {
-    let dist = |[a, b]: [Pos2; 2]| {
-        let ab = b - a;
-        let t = ((p - a).dot(ab) / ab.length_sq().max(1e-6)).clamp(0.0, 1.0);
-        p.distance(a + ab * t)
-    };
-    hits.iter().filter(|h| dist(h.1) < 6.0).min_by(|a, b| dist(a.1).total_cmp(&dist(b.1))).copied()
-}
-
-/// World to parent space for a 3D layer (identity without a parent).
-fn parent_world_inverse(ctx: &EvalCtx, l: &Layer) -> effectcraft_engine::geom::Mat4 {
-    match l.parent.and_then(|p| ctx.comp.layer(p)) {
-        Some(p) => ctx.world_matrix(p).inverse().unwrap_or_default(),
-        None => effectcraft_engine::geom::Mat4::IDENTITY,
-    }
-}
-
-/// Parent-space position change per comp pixel of drag (x and y) for a layer: 2D layers map
-/// through the parent transform; 3D layers move in the view plane at their depth.
-fn drag_axes(ctx: &EvalCtx, l: &Layer) -> ([f64; 3], [f64; 3]) {
-    if !l.is_3d() {
-        let inv = parent_inverse(ctx, l);
-        let a = inv.apply_vec(gv2(1.0, 0.0));
-        let b = inv.apply_vec(gv2(0.0, 1.0));
-        return ([a.x, a.y, 0.0], [b.x, b.y, 0.0]);
-    }
-    let cam = cam_state(ctx);
-    let anchor = l.transform().map(|tr| ctx.v3(l, tr, "anchor", [0.0; 3])).unwrap_or([0.0; 3]);
-    let wp = ctx.world_matrix(l).apply(anchor.into());
-    let k = if cam.ortho { 1.0 / cam.zoom.max(1e-9) } else { cam.depth(wp).max(1.0) / cam.zoom.max(1e-9) };
-    let pinv = parent_world_inverse(ctx, l);
-    let a = pinv.apply_vec(cam.right() * k);
-    let b = pinv.apply_vec(cam.down() * k);
-    ([a.x, a.y, a.z], [b.x, b.y, b.z])
-}
-
-/// Wireframes of cameras (frustum, point of interest) and lights (position, direction) as seen
-/// through the current 3D view.
-/// Camera and light wireframes seen through `cam` (`through_active`: `cam` is the active camera,
-/// which is then not drawn). `pane` names the automation ids: `None` for the main view
-/// (`viewer.camera.<id>`), `Some(view)` for a view of a 2- or 4-view layout
-/// (`viewer.view.<view>.camera.<id>`).
-#[allow(clippy::too_many_arguments)]
-fn draw_rigs(
-    app: &mut EffectcraftApp,
-    painter: &egui::Painter,
-    map: &ViewerMap,
-    ectx: &EvalCtx,
-    selected: &[LayerId],
-    cam: CameraState,
-    through_active: bool,
-    pane: Option<&str>,
-) {
-    use effectcraft_engine::geom::Vec3;
-    use effectcraft_engine::project::{LayerSource, LightKind};
-    let (w, h) = (ectx.comp.width as f64, ectx.comp.height as f64);
-    let active = ectx.comp.active_camera(ectx.time).map(|c| c.id);
-    let prefix = pane.map(|v| format!("viewer.view.{v}.")).unwrap_or_else(|| "viewer.".to_string());
-    let proj = |p: Vec3| cam.project(w, h, p).map(|v| map.to_screen([v.x, v.y]));
-    let seg = |a: Vec3, b: Vec3, stroke: Stroke| {
-        if let (Some(x), Some(y)) = (proj(a), proj(b)) {
-            painter.line_segment([x, y], stroke);
-        }
-    };
-    for l in ectx.comp.layers.iter().filter(|l| (l.is_camera() || l.is_light()) && l.is_active_at(ectx.time)) {
-        let sel = selected.contains(&l.id);
-        let col = app.tokens.label(l.label).gamma_multiply(if sel { 1.0 } else { 0.6 });
-        let stroke = Stroke::new(if sel { 1.5 } else { 1.0 }, col);
-        let (eye, fwd, down) = three_d::camera::layer_frame(ectx, l);
-        let poi = |l: &Layer| -> Option<Vec3> {
-            let pr = l.transform()?.get("poi").filter(|_| three_d::camera::is_two_node(l))?;
-            Some(three_d::camera::parent_world(ectx, l).apply(ectx.value(l, pr).as_vec3().into()))
-        };
-        if l.is_camera() {
-            if through_active && Some(l.id) == active {
-                continue;
-            }
-            let zoom = l.props.prop("cameraOptions/zoom").map(|p| ectx.value(l, p).as_f64()).unwrap_or(1000.0);
-            let right = down.cross(fwd);
-            // Frustum to a plane at a quarter of the zoom distance.
-            let k = 0.25;
-            let c = eye + fwd * (zoom * k);
-            let corners = [(-1.0, -1.0), (1.0, -1.0), (1.0, 1.0), (-1.0, 1.0)].map(|(sx, sy)| c + right * (sx * w * 0.5 * k) + down * (sy * h * 0.5 * k));
-            for i in 0..4 {
-                seg(eye, corners[i], stroke);
-                seg(corners[i], corners[(i + 1) % 4], stroke);
-            }
-            if let Some(poi) = poi(l) {
-                seg(eye, poi, Stroke::new(1.0, col.gamma_multiply(0.6)));
-                if let Some(s) = proj(poi) {
-                    painter.circle_stroke(s, 4.0, stroke);
-                }
-            }
-            if let Some(s) = proj(eye) {
-                app.auto.add(&format!("{prefix}camera.{}", l.id.0), Rect::from_center_size(s, vec2(14.0, 14.0)), &l.name);
-            }
-        } else {
-            let LayerSource::Light { kind } = l.source else { continue };
-            if kind == LightKind::Ambient {
-                continue;
-            }
-            let Some(s) = proj(eye) else { continue };
-            painter.circle_stroke(s, 6.0, stroke);
-            for i in 0..8 {
-                let a = i as f32 * std::f32::consts::FRAC_PI_4;
-                let d = vec2(a.cos(), a.sin());
-                painter.line_segment([s + d * 8.0, s + d * 12.0], stroke);
-            }
-            if matches!(kind, LightKind::Spot | LightKind::Parallel) {
-                let target = poi(l).unwrap_or(eye + fwd * 300.0);
-                seg(eye, target, Stroke::new(1.0, col.gamma_multiply(0.7)));
-                if let Some(q) = proj(target) {
-                    painter.circle_stroke(q, 3.0, stroke);
-                }
-            }
-            app.auto.add(&format!("{prefix}light.{}", l.id.0), Rect::from_center_size(s, vec2(16.0, 16.0)), &l.name);
-        }
-    }
-}
-
-/// Pen tool press at `pos`: continue the path in progress (pressing its first vertex closes it),
-/// resume an open path whose last vertex is pressed, add a vertex on a visible path's segment, or
-/// start a new path: a mask on the selected footage/solid layer (or shape layer, with Tool Creates
-/// Mask), a shape path (Shape n group with the Tools bar's Fill and Stroke) on the selected shape
-/// layer, or a new shape layer when nothing is selected. The placed point snaps.
-/// Add a Position keyframe at a motion path's frame, keeping the path where it is.
-fn add_motion_key(app: &mut EffectcraftApp, f: ov::PathFrame) {
-    if let Err(e) = app.session.execute("prop.addKey", json!({"layer": f.layer.0, "prop": f.prop, "time": f.time.seconds()})) {
-        app.ui.status = e.to_string();
-    }
-}
-
-/// Select only the motion path's keyframe `k` (what the vertex tools act on).
-fn select_motion_key(app: &mut EffectcraftApp, k: &ov::KeyHit) -> bool {
-    app.session.execute("keys.select", json!({"keys": [{"layer": k.layer.0, "prop": k.prop, "time": k.time.seconds()}]})).is_ok()
-}
-
-/// The pointer for a Pen slot tool: the tool's own pen, the Pen showing Add Vertex's over a path
-/// it would add a point to (After Effects).
-fn pen_cursor_icon(tool: Tool, over_path: bool) -> crate::icons::Icon {
-    use crate::icons::Icon;
-    match tool {
-        Tool::Pen if over_path => Icon::PenAdd,
-        Tool::PenAdd => Icon::PenAdd,
-        Tool::PenDelete => Icon::PenDelete,
-        Tool::PenConvert => Icon::PenConvert,
-        Tool::MaskFeather => Icon::MaskFeather,
-        _ => Icon::Pen,
-    }
-}
-
-/// Paint pen pointer `icon` with its tip at `at`, outlined for any background.
-fn pen_cursor(ctx: &egui::Context, at: Pos2, icon: crate::icons::Icon) {
-    use crate::icons::Icon;
-    // Where each glyph's tip sits in its 16 × 16 box.
-    let tip = match icon {
-        Icon::PenAdd | Icon::PenDelete | Icon::MaskFeather => vec2(6.0, 2.5),
-        Icon::PenConvert => vec2(8.0, 3.5),
-        _ => vec2(8.0, 1.8),
-    };
-    let painter = ctx.layer_painter(egui::LayerId::new(egui::Order::Tooltip, egui::Id::unique("viewer-pen-cursor")));
-    let rect = Rect::from_min_size(at - tip, vec2(16.0, 16.0));
-    for d in [vec2(-1.0, 0.0), vec2(1.0, 0.0), vec2(0.0, -1.0), vec2(0.0, 1.0)] {
-        crate::icons::paint(&painter, rect.translate(d), icon, Color32::BLACK);
-    }
-    crate::icons::paint(&painter, rect, icon, Color32::WHITE);
-}
-
-/// Handle a Pen-tool press at `pos`: close the current path when its first vertex is hit; otherwise append a snapped
-/// (Shift: 45-degree) vertex, resume an open path's end, add a motion-path keyframe, insert a vertex on a visible
-/// path segment, or start a new mask/shape path on the selected layer or a new shape layer. Records the resulting
-/// path id and tangent gesture in context data for the drag that follows.
-#[allow(clippy::too_many_arguments)]
-fn pen_press(
-    app: &mut EffectcraftApp,
-    ui: &mut egui::Ui,
-    ectx: &EvalCtx,
-    map: &ViewerMap,
-    paths: &[ov::PathInfo],
-    motion_frame: Option<ov::PathFrame>,
-    pos: Pos2,
-    mods: egui::Modifiers,
-) {
-    use effectcraft_engine::project::LayerSource;
-    let gid = egui::Id::unique("viewer-gesture");
-    let current: Option<(LayerId, u64)> = ui.data(|d| d.get_temp(pen_id()));
-    let c0 = map.to_comp(pos);
-    let corr = vt::snap(app, ui.ctx(), ectx, map, &[], &[c0], mods);
-    let c = [c0[0] + corr[0], c0[1] + corr[1]];
-    if let Some((lid, uid)) = current
-        && let Some(p) = ov::path_of(ectx, lid, uid)
-        && let Some(inv) = p.m.inverse()
-    {
-        let n = p.sp.vertices.len();
-        let first = p.sp.vertices.first().map(|v| {
-            let q = p.m.apply(gv2(v[0], v[1]));
-            map.to_screen([q.x, q.y])
-        });
-        if n >= 2 && first.is_some_and(|f| f.distance(pos) < 8.0) {
-            let _ = app.session.execute("mask.setClosed", json!({"layer": lid.0, "mask": uid, "closed": true}));
-            ui.data_mut(|d| {
-                d.remove::<(LayerId, u64)>(pen_id());
-                d.remove::<Gesture>(gid);
-            });
-            return;
-        }
-        // Shift keeps the new segment at a multiple of 45° from the vertex before it (#1544).
-        let last = p.sp.vertices.last().map(|v| p.m.apply(gv2(v[0], v[1])));
-        let c = match last {
-            Some(q) if mods.shift => constrain_45([q.x, q.y], c),
-            _ => c,
-        };
-        let lp = inv.apply(gv2(c[0], c[1]));
-        let lp = [lp.x, lp.y];
-        if let Ok(v) = app.session.execute("mask.addVertex", json!({"layer": lid.0, "mask": uid, "point": lp})) {
-            let index = v.as_u64().unwrap_or(0) as usize;
-            ui.data_mut(|d| d.insert_temp(gid, Gesture::Pen { layer: lid, mask: uid, index, vertex: lp, inv, press: pos }));
-        }
-        return;
-    }
-    // Clicking the last vertex of an open path (e.g. after Esc ended it) resumes drawing it.
-    if let Some(cur) = ov::open_end_at(paths, map, pos, 8.0) {
-        ui.data_mut(|d| d.insert_temp(pen_id(), cur));
-        return;
-    }
-    // On a visible path's segment the Pen adds a vertex there; on a motion path, a keyframe.
-    if let Some(f) = motion_frame {
-        add_motion_key(app, f);
-        return;
-    }
-    if let Some((l, m, seg, t)) = ov::segment_at(paths, map, pos, 5.0) {
-        let _ = app.session.execute("mask.insertVertex", json!({"layer": l.0, "mask": m, "segment": seg, "t": t}));
-        return;
-    }
-    let target = app
-        .session
-        .state
-        .selected_layers
-        .iter()
-        .copied()
-        .find(|id| ectx.comp.layer(*id).is_some_and(|l| !l.switches.locked && (l.masks().is_some() || matches!(l.source, LayerSource::Shape))));
-    let layer = target.and_then(|id| ectx.comp.layer(id));
-    let (lid, uid, inv) = match layer {
-        Some(l) if !matches!(l.source, LayerSource::Shape) || app.session.state.shape_tool.creates_mask => {
-            let Some(inv) = l2c(ectx, l).0.inverse() else { return };
-            let lp = inv.apply(gv2(c[0], c[1]));
-            let Ok(v) = app.session.execute("mask.new", json!({"layer": l.id.0, "vertices": [[lp.x, lp.y]]})) else { return };
-            let Some(mask) = v["mask"].as_u64() else { return };
-            (l.id, mask, inv)
-        }
-        Some(l) => {
-            let Some(inv) = l2c(ectx, l).0.inverse() else { return };
-            let lp = inv.apply(gv2(c[0], c[1]));
-            let r = app.session.execute("shape.newPath", json!({"layer": l.id.0, "vertices": [[lp.x, lp.y]], "space": "layer"}));
-            let Some(path) = r.ok().and_then(|v| v["path"].as_u64()) else { return };
-            (l.id, path, inv)
-        }
-        None => {
-            // A new shape layer at the comp centre (unrotated: comp → layer is a translation).
-            let r = app.session.execute("shape.newPath", json!({"vertices": [c], "space": "comp"}));
-            let Some(v) = r.ok() else { return };
-            let (Some(l), Some(path)) = (v["layer"].as_u64(), v["path"].as_u64()) else { return };
-            let inv = Mat3::translate(gv2(-(ectx.comp.width as f64) / 2.0, -(ectx.comp.height as f64) / 2.0));
-            (LayerId(l), path, inv)
-        }
-    };
-    let lp = inv.apply(gv2(c[0], c[1]));
-    ui.data_mut(|d| {
-        d.insert_temp(pen_id(), (lid, uid));
-        d.insert_temp(gid, Gesture::Pen { layer: lid, mask: uid, index: 0, vertex: [lp.x, lp.y], inv, press: pos });
-    });
-}
-
-/// `to` moved onto the nearest line through `from` at a multiple of 45° (horizontal, vertical or
-/// diagonal), as far along it as `to` lies: the Pen's Shift-click.
-fn constrain_45(from: [f64; 2], to: [f64; 2]) -> [f64; 2] {
-    let (dx, dy) = (to[0] - from[0], to[1] - from[1]);
-    if !(dx.is_finite() && dy.is_finite()) || (dx == 0.0 && dy == 0.0) {
-        return to;
-    }
-    let step = std::f64::consts::FRAC_PI_4;
-    let a = (dy.atan2(dx) / step).round() * step;
-    let (ux, uy) = (a.cos(), a.sin());
-    let along = dx * ux + dy * uy;
-    [from[0] + ux * along, from[1] + uy * along]
-}
-
-/// Visible, unlocked layers eligible for viewer hit tests, in front-to-back order.
-/// Solo scope matches the renderer: any soloed AV layer activates it at every time (as in After
-/// Effects), even when hidden, locked or outside its in-out range.
-pub(crate) fn selectable_layers(comp: &Comp, time: Tick) -> impl Iterator<Item = &Layer> {
-    let any_solo = comp.layers.iter().any(|l| l.switches.solo && l.source.is_av());
-    comp.layers
-        .iter()
-        .filter(move |l| l.is_active_at(time) && l.switches.video && !l.switches.locked && !l.is_camera() && !l.is_light() && (!any_solo || l.switches.solo))
-}
-
-/// Selectable layers under a comp point, front to back.
-pub(crate) fn layers_at<'a, 'b>(ectx: &'b EvalCtx<'a>, cpt: [f64; 2]) -> impl Iterator<Item = &'a Layer> + 'b {
-    selectable_layers(ectx.comp, ectx.time).filter(move |l| layer_quad(ectx, l).is_some_and(|(_, q, _)| point_in_quad(cpt, &q)))
-}
-
-/// Topmost selectable layer under a comp point.
-pub(crate) fn layer_at<'a>(ectx: &EvalCtx<'a>, cpt: [f64; 2]) -> Option<&'a Layer> {
-    layers_at(ectx, cpt).next()
-}
-
-/// The layer a press at a comp point acts on, selected (Shift toggles the topmost layer). As in
-/// After Effects, a selected layer under the point comes before the layers in front of it, so it
-/// can be dragged where they cover it; otherwise the topmost layer (#230).
-pub(crate) fn pick(app: &mut EffectcraftApp, ectx: &EvalCtx, cpt: [f64; 2], toggle: bool) -> Option<LayerId> {
-    if toggle {
-        let hit = layer_at(ectx, cpt)?.id;
-        let _ = app.session.execute("layer.select", json!({"layers": [hit.0], "toggle": true}));
-        return Some(hit);
-    }
-    let selected = &app.session.state.selected_layers;
-    let hits: Vec<LayerId> = layers_at(ectx, cpt).map(|l| l.id).collect();
-    let hit = *hits.iter().find(|id| selected.contains(id)).or(hits.first())?;
-    if !selected.contains(&hit) {
-        let _ = app.session.execute("layer.select", json!({"layers": [hit.0]}));
-    }
-    Some(hit)
-}
-
-/// Where a shape drag is going to land: a mask on the selected layer, a group inside it, or a new
-/// shape layer.
-#[derive(Clone, Copy, PartialEq, Eq)]
-enum ShapeTarget {
-    Mask,
-    IntoLayer,
-    NewLayer,
-}
-
-impl ShapeTarget {
-    /// What the drag will make and where, named the way the ghost captions it.
-    fn label(self, layer_name: &str) -> String {
-        match self {
-            ShapeTarget::Mask => format!("Mask on “{layer_name}”"),
-            ShapeTarget::IntoLayer => format!("Into “{layer_name}”"),
-            ShapeTarget::NewLayer => "New shape layer".to_string(),
-        }
-    }
-}
-
-/// A shape drag as it stands, after the Tools' normalisations: the path it will make and where it
-/// will land.
-struct ShapeDrag {
-    /// The `shape.newShape` / `layer.addMask` kind for the tool.
-    kind: &'static str,
-    /// Comp-space centre and size, what the drag will make.
-    centre: [f64; 2],
-    size: [f64; 2],
-    target: ShapeTarget,
-    /// The selected layer's name and the index its next mask would take, for the ghost's caption
-    /// and colour.
-    layer_name: String,
-    mask_index: usize,
-}
-
-/// The kind `tool` draws, as `shape.newShape` / `layer.addMask` name it.
-fn shape_kind(tool: Tool) -> &'static str {
-    match tool {
-        Tool::Rectangle => "rect",
-        Tool::RoundedRect => "rounded",
-        Tool::Ellipse => "ellipse",
-        Tool::Polygon => "polygon",
-        _ => "star",
-    }
-}
-
-/// What a shape tool drag from `start` to `end` makes, or `None` while it is too small to make
-/// anything. Alt (Option) draws from the press point and Shift squares the box; the live ghost and
-/// [`create_shape`] both go through this, so the drag always shows what it will commit.
-fn shape_drag(app: &EffectcraftApp, tool: Tool, start: [f64; 2], end: [f64; 2], mods: egui::Modifiers) -> Option<ShapeDrag> {
-    let comp = app.session.active_comp()?;
-    let selected = app.session.state.selected_layers.first().copied();
-    let sel = selected.and_then(|id| comp.layer(id));
-    // A footage, solid or other non-shape layer selected, or a shape layer with Tool Creates
-    // Mask: a mask on that layer. Otherwise the engine's own target: the first selected unlocked
-    // shape layer, else a new one.
-    let target = match sel {
-        Some(l) if l.source.is_av() && (app.session.state.shape_tool.creates_mask || !matches!(l.source, LayerSource::Shape)) => (ShapeTarget::Mask, Some(l)),
-        _ => match effectcraft_engine::commands::shape_tool::selected_shape_target(&app.session, comp).and_then(|id| comp.layer(id)) {
-            Some(l) => (ShapeTarget::IntoLayer, Some(l)),
-            None => (ShapeTarget::NewLayer, None),
-        },
-    };
-    let (target, layer) = target;
-    let mask_index = if target == ShapeTarget::Mask { layer.and_then(|l| l.masks()).map_or(0, |m| m.groups().count()) } else { 0 };
-    let (mut w, mut h) = ((end[0] - start[0]).abs(), (end[1] - start[1]).abs());
-    // Ctrl/Cmd draws from the press point as the centre, as in After Effects.
-    if mods.command {
-        w *= 2.0;
-        h *= 2.0;
-    }
-    if w < 2.0 && h < 2.0 {
-        return None;
-    }
-    if mods.shift {
-        let m = w.max(h);
-        w = m;
-        h = m;
-    }
-    Some(ShapeDrag {
-        kind: shape_kind(tool),
-        centre: if mods.command { start } else { [start[0].min(end[0]) + w / 2.0, start[1].min(end[1]) + h / 2.0] },
-        size: [w, h],
-        target,
-        layer_name: layer.map_or_else(String::new, |l| l.name.clone()),
-        mask_index,
-    })
-}
-
-/// The Tools bar's paint colour as bytes, dimmed by `alpha` so the comp shows through the ghost.
-fn paint_rgb(c: [f32; 3], opacity: f64, alpha: f32) -> Color32 {
-    let f = |k: f32| (k.clamp(0.0, 1.0) * 255.0).round() as u8;
-    Color32::from_rgb(f(c[0]), f(c[1]), f(c[2])).gamma_multiply((opacity.clamp(0.0, 100.0) / 100.0) as f32 * alpha)
-}
-
-/// Draw a shape drag as it will land: the tool's own path, filled with the Tools bar's Fill and
-/// outlined in its Stroke (or the mask colour, for a mask), captioned with where it goes.
-fn draw_shape_ghost(painter: &egui::Painter, map: &ViewerMap, app: &EffectcraftApp, d: &ShapeDrag, t: &Tokens) {
-    // The engine's own geometry for the kind, so the ghost is the shape and not a stand-in for it.
-    let Some(sp) = effectcraft_engine::commands::shape_tool::mask_path(d.kind, d.centre, d.size) else { return };
-    let mut pts = ov::flatten(&sp, &Mat3::IDENTITY, map);
-    if pts.first() == pts.last() {
-        pts.pop();
-    }
-    if pts.len() < 3 {
-        return;
-    }
-    let tool = &app.session.state.shape_tool;
-    let (fill, line) = match d.target {
-        ShapeTarget::Mask => {
-            let [r, g, b] = effectcraft_engine::prefs::mask_color(app.session.prefs.appearance.cycle_mask_colors, d.mask_index);
-            (Color32::from_rgb(r, g, b).gamma_multiply(0.25), Color32::from_rgb(r, g, b))
-        }
-        _ => {
-            let stroke_on = tool.stroke.kind != PaintKind::None && tool.stroke_width > 0.0;
-            (
-                if tool.fill.kind == PaintKind::None { Color32::TRANSPARENT } else { paint_rgb(tool.fill.color, tool.fill.opacity, 0.45) },
-                if stroke_on { paint_rgb(tool.stroke.color, tool.stroke.opacity, 1.0) } else { t.accent },
-            )
-        }
-    };
-    let Some(bounds) = bounds_of(&pts) else { return };
-    // A screen-width outline reads at every zoom, where a comp-pixel hairline does not.
-    painter.add(egui::Shape::Path(egui::epaint::PathShape { points: pts, closed: true, fill, stroke: Stroke::new(1.5, line).into() }));
-    // Caption it with where the shape lands: a mask, a group in the selected shape layer or a
-    // new layer.
-    let font = Tokens::ui(11.0);
-    let galley = painter.layout_no_wrap(d.target.label(&d.layer_name), font, line);
-    let caption = Rect::from_min_size(pos2(bounds.left(), bounds.top() - 5.0 - galley.size().y), galley.size());
-    painter.rect_filled(caption.expand(3.0), 2.0, Color32::from_black_alpha(150));
-    painter.galley(caption.min, galley, line);
-}
-
-/// The bounds of points on screen, or `None` for an empty set.
-fn bounds_of(pts: &[Pos2]) -> Option<Rect> {
-    let first = *pts.first()?;
-    let mut r = Rect::from_min_max(first, first);
-    for p in pts.iter().skip(1) {
-        r.extend_with(*p);
-    }
-    Some(r)
-}
-
-fn create_shape(app: &mut EffectcraftApp, tool: Tool, a: [f64; 2], b: [f64; 2], mods: egui::Modifiers) {
-    let Some(d) = shape_drag(app, tool, a, b, mods) else { return };
-    let (kind, (w, h), (cx, cy)) = (d.kind, (d.size[0], d.size[1]), (d.centre[0], d.centre[1]));
-    // A mask on the selected layer, as the ghost showed.
-    if d.target == ShapeTarget::Mask {
-        // In layer space: invert the layer transform.
-        let sel_layer = app.session.state.selected_layers.first().copied().and_then(|id| app.session.active_comp().and_then(|c| c.layer(id)).cloned());
-        if let Some(l) = sel_layer
-            && let Some(comp) = app.session.active_comp_arc()
-        {
-            let ectx = EvalCtx {
-                project: &app.session.project,
-                comp_id: app.session.active_comp_id().unwrap_or_default(),
-                comp: &comp,
-                time: app.session.time(),
-                expr: None,
-                footage: None,
-            };
-            let inv = l2c(&ectx, &l).0.inverse().unwrap_or(Mat3::IDENTITY);
-            let p0 = inv.apply(gv2(cx - w / 2.0, cy - h / 2.0));
-            let p1 = inv.apply(gv2(cx + w / 2.0, cy + h / 2.0));
-            let rect = [p0.x.min(p1.x), p0.y.min(p1.y), (p1.x - p0.x).abs(), (p1.y - p0.y).abs()];
-            if let Err(e) = app.session.execute("layer.addMask", json!({"layer": l.id.0, "shape": kind, "rect": rect})) {
-                app.ui.status = e.to_string();
-            }
-        }
-        return;
-    }
-    // Into the selected shape layer's Contents as a new group (as in After Effects), else a new
-    // shape layer; painted with the Tools bar's Fill and Stroke.
-    if let Err(e) = app.session.execute("shape.newShape", json!({"kind": kind, "size": [w, h], "position": [cx, cy]})) {
-        app.ui.status = e.to_string();
-    }
-}
-
-/// Draw the no-composition viewer with New Composition and New Composition From Footage buttons, accepting Project
-/// items dropped on it to create the first composition.
-fn empty_state(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
-    let t = app.tokens;
-    let p = ui.painter().clone();
-    p.rect_filled(rect, 0.0, t.pasteboard);
-    let c = rect.center();
-    p.text(c - vec2(0.0, 40.0), Align2::CENTER_CENTER, crate::i18n::tr("Composition"), Tokens::semibold(16.0), t.text);
-    let b1 = Rect::from_center_size(c + vec2(0.0, 0.0), vec2(220.0, 30.0));
-    if widgets::text_button(ui, b1, "New Composition", true, &t, egui::Id::unique("empty-newcomp")).clicked() {
-        crate::panels::dialogs::open_new_comp(app);
-    }
-    app.auto.add("viewer.empty.newComp", b1, "New Composition");
-    let b2 = Rect::from_center_size(c + vec2(0.0, 40.0), vec2(220.0, 30.0));
-    if widgets::text_button(ui, b2, "New Composition From Footage", false, &t, egui::Id::unique("empty-fromfootage")).clicked() {
-        let _ = crate::menus::invoke(app, &ui.ctx().clone(), "file.import", json!({}));
-    }
-    app.auto.add("viewer.empty.import", b2, "New Composition From Footage");
-    // A Project item dropped on the empty viewer creates the first composition,
-    // just like dropping it onto an empty Timeline (#684). Multiple selected
-    // items use the existing New Comp from Selection dialog.
-    let ctx = ui.ctx().clone();
-    if let Some(crate::panels::DragPayload::Item(dragged)) = egui::DragAndDrop::payload::<crate::panels::DragPayload>(&ctx).as_deref()
-        && ui.rect_contains_pointer(rect)
-    {
-        let items: Vec<effectcraft_engine::project::ItemId> = crate::panels::project_drop_items(app, *dragged)
-            .into_iter()
-            .map(effectcraft_engine::project::ItemId)
-            .filter(|id| {
-                app.session.project.item(*id).is_some_and(|item| match &item.kind {
-                    effectcraft_engine::project::ItemKind::Footage(f) => f.kind != effectcraft_engine::project::FootageKind::Data,
-                    effectcraft_engine::project::ItemKind::Solid(_) | effectcraft_engine::project::ItemKind::Comp(_) => true,
-                    _ => false,
-                })
-            })
-            .collect();
-        if !items.is_empty() {
-            p.rect_stroke(rect.shrink(2.0), 0.0, Stroke::new(2.0, t.accent), StrokeKind::Inside);
-            app.auto.add("viewer.newCompDrop", rect, "Drop footage to create a composition");
-            if ctx.input(|i| i.pointer.any_released()) {
-                app.session.state.project_selection = items;
-                if let Err(e) = crate::menus::invoke(app, &ctx, "file.newCompFromSelection", json!({})) {
-                    app.ui.status = e;
-                }
-                egui::DragAndDrop::clear_payload(&ctx);
-            }
-        }
-    }
-}
-
-/// `#rrggbb` → sRGB bytes.
-/// A grid or guide line in the Grids & Guides style: `lines`, `dashed` or `dots`.
-pub(crate) fn styled_line(painter: &egui::Painter, pts: [Pos2; 2], stroke: Stroke, style: &str) {
-    match style {
-        "dashed" => {
-            painter.add(egui::Shape::dashed_line(&pts, stroke, 6.0, 4.0));
-        }
-        "dots" => {
-            painter.add(egui::Shape::dotted_line(&pts, stroke.color, 4.0, stroke.width.max(1.0) * 0.75));
-        }
-        _ => {
-            painter.line_segment(pts, stroke);
-        }
-    }
-}
-
-/// `p` (points) moved to the nearest physical pixel corner at `ppp` pixels per point.
-pub(crate) fn snap_to_pixels(p: Pos2, ppp: f32) -> Pos2 {
-    if !(ppp.is_finite() && ppp > 0.0 && p.x.is_finite() && p.y.is_finite()) {
-        return p;
-    }
-    pos2((p.x * ppp).round() / ppp, (p.y * ppp).round() / ppp)
-}
-
-/// Texture filtering for Viewer Zoom Quality: More Accurate = bilinear, Faster = nearest. As in
-/// After Effects, a magnified frame (above 100 %, or a lower Resolution) always shows its pixels
-/// as blocks, never smoothed, in either mode (#882).
-pub(crate) fn zoom_texture_options(smooth: bool) -> egui::TextureOptions {
-    if smooth { egui::TextureOptions { magnification: egui::TextureFilter::Nearest, ..egui::TextureOptions::LINEAR } } else { egui::TextureOptions::NEAREST }
-}
-
-/// The sampler GPU frames (mipmapped display textures) are drawn with: More Accurate filters
-/// bilinearly within and between mip levels, so a frame shown below 100 % is averaged instead of
-/// skipping pixels (#417); Faster takes the nearest pixel of the full-size frame. Magnified, both
-/// show the nearest pixel (#882).
-pub(crate) fn zoom_sampler(smooth: bool) -> eframe::wgpu::SamplerDescriptor<'static> {
-    use eframe::wgpu::{FilterMode, MipmapFilterMode, SamplerDescriptor};
-    let label = Some("viewer frame");
-    if smooth {
-        SamplerDescriptor {
-            label,
-            mag_filter: FilterMode::Nearest,
-            min_filter: FilterMode::Linear,
-            mipmap_filter: MipmapFilterMode::Linear,
-            ..Default::default()
-        }
-    } else {
-        SamplerDescriptor { label, lod_max_clamp: 0.0, ..Default::default() }
-    }
-}
-
-/// The whole factor a CPU frame is averaged down by for its texture when `pixels` of it are drawn
-/// over `screen` screen pixels: about one texel per screen pixel, so bilinear filtering never
-/// skips frame pixels — the CPU frames' counterpart of the GPU frames' mip levels (#417). Faster
-/// keeps every pixel.
-pub(crate) fn minify_factor(smooth: bool, pixels: f64, screen: f64) -> usize {
-    let k = (pixels / screen + 1e-3).floor();
-    if smooth && k >= 1.0 { k.min(256.0) as usize } else { 1 }
-}
-
 pub(crate) use crate::widgets::hex_rgb;
 
-/// The Extended Viewer's render region for this frame (see [`ViewerState::extended`]):
-/// Settings ▸ 3D ▸ Extended Viewer on, the comp has 3D layers and the view is a custom 3D view
-/// (or Draft 3D is on), and part of the visible viewer lies outside the comp frame.
-///
-/// [`ViewerState::extended`]: crate::state::ViewerState::extended
-pub(crate) fn extended_region(
-    app: &EffectcraftApp,
-    comp: &effectcraft_engine::project::Comp,
-    cid: effectcraft_engine::project::ItemId,
-    map: ViewerMap,
-) -> Option<[f64; 4]> {
-    if !app.session.prefs.three_d.extended_viewer || !comp.has_3d() || app.session.state.region_of_interest.is_some() {
-        return None;
-    }
-    let view = app.session.state.views3d.get(&cid).map(|v| v.current).unwrap_or_default();
-    if view == View3D::ActiveCamera && !comp.draft_3d {
-        return None;
-    }
-    let a = map.to_comp(map.area.min);
-    let b = map.to_comp(map.area.max);
-    effectcraft_engine::render::extended_region(comp.width, comp.height, [a[0], a[1], b[0], b[1]], 1.0)
-}
+mod frame;
+mod geometry;
+mod gesture;
+mod shapes;
+mod tools;
+mod view;
 
-fn rect_of(map: &ViewerMap, r: Option<[f64; 4]>) -> Rect {
-    let [x, y, w, h] = r.unwrap_or_default();
-    Rect::from_min_max(map.to_screen([x, y]), map.to_screen([x + w, y + h]))
-}
-
-/// Put a rendered frame on screen: CPU pixels go into an egui texture, averaged down by `minify`
-/// (see [`minify_factor`]); GPU frames are drawn straight from their wgpu texture (registered with
-/// egui-wgpu, no readback).
-fn show_frame(app: &mut EffectcraftApp, ctx: &egui::Context, key: crate::frames::FrameKey, img: crate::frames::FrameImage, minify: usize) {
-    use crate::frames::FrameImage;
-    // Settings ▸ Previews ▸ Viewer Zoom Quality.
-    let smooth = app.session.prefs.viewer_zoom_smooth();
-    let opts = zoom_texture_options(smooth);
-    match img {
-        FrameImage::Cpu(img) => {
-            // Frames wider or taller than the GPU's texture limit go up averaged down too (#201).
-            let max = crate::frames::max_texture_side(ctx);
-            let fitted = crate::frames::fit_shared_texture_by(&img, max, minify);
-            match &mut app.viewer_tex {
-                Some((tex, k, m)) if tex.size() == fitted.size() => {
-                    tex.set(fitted, opts);
-                    (*k, *m) = (key, minify);
-                }
-                _ => app.viewer_tex = Some((ctx.load_texture("viewer-frame", fitted, opts), key, minify)),
-            }
-            app.viewer_shown = app.viewer_tex.as_ref().map(|(t, k, _)| (t.id(), *k));
-            app.viewer_image = Some(img);
-            vt::set_texture_roi(ctx, app.session.state.region_of_interest.or(app.ui.viewer.extended));
-        }
-        FrameImage::Gpu(f) => {
-            let Some(rs) = &app.wgpu else { return };
-            let view = f.texture.create_view(&Default::default());
-            let mut ren = rs.renderer.write();
-            let id = match &app.viewer_native {
-                Some((id, _, _)) => {
-                    ren.update_egui_texture_from_wgpu_texture_with_sampler_options(&rs.device, &view, zoom_sampler(smooth), *id);
-                    *id
-                }
-                None => ren.register_native_texture_with_sampler_options(&rs.device, &view, zoom_sampler(smooth)),
-            };
-            drop(ren);
-            app.viewer_native = Some((id, key, f));
-            app.viewer_shown = Some((id, key));
-            // Pixels are read back on demand (viewer_pixels).
-            app.viewer_image = None;
-        }
-    }
-}
+use frame::{empty_state, rect_of, show_frame};
+pub(crate) use frame::{extended_region, minify_factor, snap_to_pixels, styled_line, zoom_sampler, zoom_texture_options};
+#[cfg(test)]
+use geometry::{box_corners, project_clipped};
+use geometry::{
+    cam_state, drag_ratio, handle_axes, handle_cursor, handle_point, one_axis, project_segment, quad_intersects_box, rotate_value, selected_others,
+    snap_handle, turn_delta,
+};
+pub(crate) use geometry::{from_effect_space, fx2c, l2c, layer_outline, layer_quad};
+use gesture::{Gesture, HANDLE, ROTO_HINT, pen_id, roi_drag, roi_handles, vertex_grab_radius};
+use shapes::{create_shape, draw_shape_ghost, shape_drag};
+pub(crate) use shapes::{layer_at, layers_at, pick, selectable_layers};
+#[cfg(test)]
+use tools::constrain_45;
+use tools::{add_motion_key, axis_at, axis_drag, drag_axes, draw_rigs, parent_world_inverse, pen_cursor, pen_cursor_icon, pen_press, select_motion_key};
+pub(crate) use view::checker;
+use view::{aux_views, locked_pane};
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use effectcraft_engine::geom::{Mat4, vec3};
-
-    /// #1544: Shift-clicking with the Pen keeps the new segment horizontal, vertical or diagonal.
-    #[test]
-    fn pen_shift_click_keeps_the_segment_at_45_degrees() {
-        let near = |a: [f64; 2], b: [f64; 2]| (a[0] - b[0]).abs() < 1e-9 && (a[1] - b[1]).abs() < 1e-9;
-        let from = [100.0, 100.0];
-        assert!(near(constrain_45(from, [104.0, 180.0]), [100.0, 180.0]), "straight down");
-        assert!(near(constrain_45(from, [30.0, 97.0]), [30.0, 100.0]), "left");
-        assert!(near(constrain_45(from, [150.0, 46.0]), [152.0, 48.0]), "up and right, on the diagonal");
-        assert!(near(constrain_45(from, from), from), "on the vertex");
-        assert!(constrain_45(from, [f64::NAN, 3.0])[0].is_nan(), "a non-finite point stays as it is");
-    }
-
-    /// The Rotation tool counts past a full turn in both directions, as in After Effects: the
-    /// pointer going round the anchor 1.5 turns clockwise gives 540°, then back 2 turns gives
-    /// −180°, with no jump where atan2 wraps from 180° to −180°.
-    #[test]
-    fn rotate_tool_accumulates_revolutions() {
-        // Screen y points down, so a growing atan2 angle is clockwise on screen.
-        let drag = |start: f64, steps: &[f64]| {
-            let (mut last, mut turned, mut out) = (start, 0.0, vec![]);
-            for &a in steps {
-                // atan2's range: (−180°, 180°].
-                let a = (a + 180.0).rem_euclid(360.0) - 180.0;
-                turned += turn_delta(last, a);
-                last = a;
-                out.push(turned);
-            }
-            (last, turned, out)
-        };
-        let cw: Vec<f64> = (1..=54).map(|i| i as f64 * 10.0).collect();
-        let (last, turned, seq) = drag(0.0, &cw);
-        assert!((turned - 540.0).abs() < 1e-9, "{turned}");
-        assert!(seq.windows(2).all(|w| (w[1] - w[0] - 10.0).abs() < 1e-9), "no jump: {seq:?}");
-        assert!((rotate_value(0.0, turned, false) - 540.0).abs() < 1e-9);
-        let ccw: Vec<f64> = (1..=72).map(|i| 540.0 - i as f64 * 10.0).collect();
-        let (_, back, seq) = drag(last, &ccw);
-        assert!(seq.windows(2).all(|w| (w[1] - w[0] + 10.0).abs() < 1e-9), "no jump: {seq:?}");
-        let total = turned + back;
-        assert!((total + 180.0).abs() < 1e-9, "{total}");
-        assert!((rotate_value(30.0, total, false) + 150.0).abs() < 1e-9);
-        // Shift snaps the accumulated value, not a wrapped one.
-        assert_eq!(rotate_value(0.0, 400.0, true), 405.0);
-        assert_eq!(rotate_value(0.0, -400.0, true), -405.0);
-        // Across the seam: 170° → −170° is +20°, and back is −20°; exactly half a turn is +180°.
-        assert!((turn_delta(170.0, -170.0) - 20.0).abs() < 1e-9);
-        assert!((turn_delta(-170.0, 170.0) + 20.0).abs() < 1e-9);
-        assert_eq!(turn_delta(0.0, 180.0), 180.0);
-        assert_eq!(turn_delta(0.0, -180.0), 180.0);
-        // Never crash or poison the value on non-finite input.
-        assert_eq!(turn_delta(f64::NAN, 10.0), 0.0);
-        assert_eq!(turn_delta(0.0, f64::INFINITY), 0.0);
-        assert_eq!(rotate_value(15.0, f64::NAN, false), 15.0);
-    }
-
-    /// #1042: a path vertex lying under, or just beside, a bounding-box handle is grabbed
-    /// instead of the handle; away from every handle the reach is unchanged.
-    #[test]
-    fn vertex_reaches_as_far_as_a_box_handle_over_it() {
-        let handle = pos2(100.0, 100.0);
-        let vertex = pos2(100.0, 100.0);
-        // The press lands 8 points off the vertex, still on the handle's square.
-        let press = pos2(108.0, 100.0);
-        let pick = |p: Pos2, handles: &[Pos2]| vertex.distance(p) < vertex_grab_radius(p, handles.iter().copied());
-        assert!(handle.distance(press) < HANDLE + 2.0, "the handle would take this press");
-        assert!(pick(press, &[handle]), "the vertex wins over the handle");
-        assert!(!pick(press, &[]), "no handle there: the usual reach");
-        assert!(pick(pos2(105.0, 100.0), &[]));
-        assert!(!pick(pos2(120.0, 100.0), &[handle]), "past the handle: nothing");
-    }
-
-    /// #882: the frame's corner sits on a physical pixel at any display scaling, so 100 % maps
-    /// comp pixels 1:1 onto screen pixels.
-    #[test]
-    fn frame_origin_snaps_to_physical_pixels() {
-        for ppp in [1.0f32, 1.25, 1.5, 1.75, 2.0] {
-            for p in [pos2(-201.12, 72.4), pos2(689.8, 239.75), pos2(0.3, -0.37)] {
-                let s = snap_to_pixels(p, ppp);
-                for v in [s.x * ppp, s.y * ppp] {
-                    assert!((v - v.round()).abs() < 1e-3, "ppp {ppp}: {p:?} → {s:?}");
-                }
-                assert!((s - p).length() <= 0.71 / ppp, "moved by at most half a pixel: {p:?} → {s:?}");
-            }
-        }
-        assert_eq!(snap_to_pixels(pos2(1.3, 2.0), 0.0), pos2(1.3, 2.0));
-    }
-
-    /// #882: a magnified frame shows its pixels as blocks in both Zoom Quality modes; More
-    /// Accurate only smooths when the frame is shown smaller.
-    #[test]
-    fn magnified_frames_are_never_smoothed() {
-        use eframe::wgpu::FilterMode;
-        for smooth in [true, false] {
-            assert_eq!(zoom_texture_options(smooth).magnification, egui::TextureFilter::Nearest);
-            assert_eq!(zoom_sampler(smooth).mag_filter, FilterMode::Nearest);
-        }
-        assert_eq!(zoom_texture_options(true).minification, egui::TextureFilter::Linear);
-        assert_eq!(zoom_sampler(true).min_filter, FilterMode::Linear);
-    }
-
-    /// A perspective-like homography: w = 100 + y (the plane crosses the camera at y = −100).
-    fn tilted() -> Mat3 {
-        Mat3([[100.0, 0.0, 0.0], [0.0, 100.0, 0.0], [0.0, 1.0, 100.0]])
-    }
-
-    /// #572: a box reaching behind the camera is clipped at the near plane instead of flipping
-    /// through infinity into long lines.
-    #[test]
-    fn outlines_clip_at_the_near_plane() {
-        let m = tilted();
-        let front = project_clipped(&m, &box_corners([-50.0, -50.0, 50.0, 50.0]));
-        assert_eq!(front.len(), 4);
-        let crossing = project_clipped(&m, &box_corners([-50.0, -150.0, 50.0, 50.0]));
-        assert_eq!(crossing.len(), 4, "{crossing:?}");
-        // Nothing flipped through infinity: a corner behind the camera (y = −150, w = −50) would
-        // land at y = +300 if it were projected as is; clipped at the near plane it runs off far
-        // above (negative y) instead, and the front corners stay where they were.
-        assert!(crossing.iter().all(|p| p[0].is_finite() && p[1].is_finite() && p[1] < 34.0), "{crossing:?}");
-        assert!(project_clipped(&m, &box_corners([-50.0, -400.0, 50.0, -200.0])).is_empty(), "wholly behind");
-    }
-
-    #[test]
-    fn axis_drag_follows_the_arrow_and_ignores_drag_across_it() {
-        let (ax, ay) = axis_drag([0.0, 0.0, 60.0], [24.0, -24.0]);
-        let at = |d: [f64; 2]| [0, 1, 2].map(|i| ax[i] * d[0] + ay[i] * d[1]);
-        assert_eq!(at([24.0, -24.0]), [0.0, 0.0, 60.0]);
-        assert_eq!(at([-12.0, 12.0]), [0.0, 0.0, -30.0]);
-        assert_eq!(at([10.0, 10.0]), [0.0, 0.0, 0.0]);
-    }
-
-    #[test]
-    fn gizmo_segments_clip_at_the_near_plane() {
-        // w = 100 + z.
-        let pc = Mat4([[100.0, 0.0, 0.0, 0.0], [0.0, 100.0, 0.0, 0.0], [0.0, 0.0, 1.0, 0.0], [0.0, 0.0, 1.0, 100.0]]);
-        let s = project_segment(&pc, vec3(10.0, 0.0, 0.0), vec3(10.0, 0.0, -300.0)).unwrap();
-        assert_eq!(s[0], [10.0, 0.0]);
-        assert!(s[1][0] > 10.0 && s[1][0].is_finite(), "toward the camera it grows, never flips: {s:?}");
-        assert!(project_segment(&pc, vec3(0.0, 0.0, -200.0), vec3(0.0, 0.0, -300.0)).is_none());
-    }
-}
+mod tests;
diff --git a/crates/ui-egui/src/panels/viewer/frame.rs b/crates/ui-egui/src/panels/viewer/frame.rs
new file mode 100644
index 000000000..ac467ecd5
--- /dev/null
+++ b/crates/ui-egui/src/panels/viewer/frame.rs
@@ -0,0 +1,183 @@
+use super::{Align2, EffectcraftApp, Pos2, Rect, Stroke, StrokeKind, Tokens, View3D, ViewerMap, json, pos2, vec2, vt, widgets};
+
+/// Draw the no-composition viewer with New Composition and New Composition From Footage buttons, accepting Project
+/// items dropped on it to create the first composition.
+pub(super) fn empty_state(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+    let t = app.tokens;
+    let p = ui.painter().clone();
+    p.rect_filled(rect, 0.0, t.pasteboard);
+    let c = rect.center();
+    p.text(c - vec2(0.0, 40.0), Align2::CENTER_CENTER, crate::i18n::tr("Composition"), Tokens::semibold(16.0), t.text);
+    let b1 = Rect::from_center_size(c + vec2(0.0, 0.0), vec2(220.0, 30.0));
+    if widgets::text_button(ui, b1, "New Composition", true, &t, egui::Id::unique("empty-newcomp")).clicked() {
+        crate::panels::dialogs::open_new_comp(app);
+    }
+    app.auto.add("viewer.empty.newComp", b1, "New Composition");
+    let b2 = Rect::from_center_size(c + vec2(0.0, 40.0), vec2(220.0, 30.0));
+    if widgets::text_button(ui, b2, "New Composition From Footage", false, &t, egui::Id::unique("empty-fromfootage")).clicked() {
+        let _ = crate::menus::invoke(app, &ui.ctx().clone(), "file.import", json!({}));
+    }
+    app.auto.add("viewer.empty.import", b2, "New Composition From Footage");
+    // A Project item dropped on the empty viewer creates the first composition,
+    // just like dropping it onto an empty Timeline (#684). Multiple selected
+    // items use the existing New Comp from Selection dialog.
+    let ctx = ui.ctx().clone();
+    if let Some(crate::panels::DragPayload::Item(dragged)) = egui::DragAndDrop::payload::<crate::panels::DragPayload>(&ctx).as_deref()
+        && ui.rect_contains_pointer(rect)
+    {
+        let items: Vec<effectcraft_engine::project::ItemId> = crate::panels::project_drop_items(app, *dragged)
+            .into_iter()
+            .map(effectcraft_engine::project::ItemId)
+            .filter(|id| {
+                app.session.project.item(*id).is_some_and(|item| match &item.kind {
+                    effectcraft_engine::project::ItemKind::Footage(f) => f.kind != effectcraft_engine::project::FootageKind::Data,
+                    effectcraft_engine::project::ItemKind::Solid(_) | effectcraft_engine::project::ItemKind::Comp(_) => true,
+                    _ => false,
+                })
+            })
+            .collect();
+        if !items.is_empty() {
+            p.rect_stroke(rect.shrink(2.0), 0.0, Stroke::new(2.0, t.accent), StrokeKind::Inside);
+            app.auto.add("viewer.newCompDrop", rect, "Drop footage to create a composition");
+            if ctx.input(|i| i.pointer.any_released()) {
+                app.session.state.project_selection = items;
+                if let Err(e) = crate::menus::invoke(app, &ctx, "file.newCompFromSelection", json!({})) {
+                    app.ui.status = e;
+                }
+                egui::DragAndDrop::clear_payload(&ctx);
+            }
+        }
+    }
+}
+
+/// `#rrggbb` → sRGB bytes.
+/// A grid or guide line in the Grids & Guides style: `lines`, `dashed` or `dots`.
+pub(crate) fn styled_line(painter: &egui::Painter, pts: [Pos2; 2], stroke: Stroke, style: &str) {
+    match style {
+        "dashed" => {
+            painter.add(egui::Shape::dashed_line(&pts, stroke, 6.0, 4.0));
+        }
+        "dots" => {
+            painter.add(egui::Shape::dotted_line(&pts, stroke.color, 4.0, stroke.width.max(1.0) * 0.75));
+        }
+        _ => {
+            painter.line_segment(pts, stroke);
+        }
+    }
+}
+
+/// `p` (points) moved to the nearest physical pixel corner at `ppp` pixels per point.
+pub(crate) fn snap_to_pixels(p: Pos2, ppp: f32) -> Pos2 {
+    if !(ppp.is_finite() && ppp > 0.0 && p.x.is_finite() && p.y.is_finite()) {
+        return p;
+    }
+    pos2((p.x * ppp).round() / ppp, (p.y * ppp).round() / ppp)
+}
+
+/// Texture filtering for Viewer Zoom Quality: More Accurate = bilinear, Faster = nearest. As in
+/// After Effects, a magnified frame (above 100 %, or a lower Resolution) always shows its pixels
+/// as blocks, never smoothed, in either mode (#882).
+pub(crate) fn zoom_texture_options(smooth: bool) -> egui::TextureOptions {
+    if smooth { egui::TextureOptions { magnification: egui::TextureFilter::Nearest, ..egui::TextureOptions::LINEAR } } else { egui::TextureOptions::NEAREST }
+}
+
+/// The sampler GPU frames (mipmapped display textures) are drawn with: More Accurate filters
+/// bilinearly within and between mip levels, so a frame shown below 100 % is averaged instead of
+/// skipping pixels (#417); Faster takes the nearest pixel of the full-size frame. Magnified, both
+/// show the nearest pixel (#882).
+pub(crate) fn zoom_sampler(smooth: bool) -> eframe::wgpu::SamplerDescriptor<'static> {
+    use eframe::wgpu::{FilterMode, MipmapFilterMode, SamplerDescriptor};
+    let label = Some("viewer frame");
+    if smooth {
+        SamplerDescriptor {
+            label,
+            mag_filter: FilterMode::Nearest,
+            min_filter: FilterMode::Linear,
+            mipmap_filter: MipmapFilterMode::Linear,
+            ..Default::default()
+        }
+    } else {
+        SamplerDescriptor { label, lod_max_clamp: 0.0, ..Default::default() }
+    }
+}
+
+/// The whole factor a CPU frame is averaged down by for its texture when `pixels` of it are drawn
+/// over `screen` screen pixels: about one texel per screen pixel, so bilinear filtering never
+/// skips frame pixels — the CPU frames' counterpart of the GPU frames' mip levels (#417). Faster
+/// keeps every pixel.
+pub(crate) fn minify_factor(smooth: bool, pixels: f64, screen: f64) -> usize {
+    let k = (pixels / screen + 1e-3).floor();
+    if smooth && k >= 1.0 { k.min(256.0) as usize } else { 1 }
+}
+
+/// The Extended Viewer's render region for this frame (see [`ViewerState::extended`]):
+/// Settings ▸ 3D ▸ Extended Viewer on, the comp has 3D layers and the view is a custom 3D view
+/// (or Draft 3D is on), and part of the visible viewer lies outside the comp frame.
+///
+/// [`ViewerState::extended`]: crate::state::ViewerState::extended
+pub(crate) fn extended_region(
+    app: &EffectcraftApp,
+    comp: &effectcraft_engine::project::Comp,
+    cid: effectcraft_engine::project::ItemId,
+    map: ViewerMap,
+) -> Option<[f64; 4]> {
+    if !app.session.prefs.three_d.extended_viewer || !comp.has_3d() || app.session.state.region_of_interest.is_some() {
+        return None;
+    }
+    let view = app.session.state.views3d.get(&cid).map(|v| v.current).unwrap_or_default();
+    if view == View3D::ActiveCamera && !comp.draft_3d {
+        return None;
+    }
+    let a = map.to_comp(map.area.min);
+    let b = map.to_comp(map.area.max);
+    effectcraft_engine::render::extended_region(comp.width, comp.height, [a[0], a[1], b[0], b[1]], 1.0)
+}
+
+pub(super) fn rect_of(map: &ViewerMap, r: Option<[f64; 4]>) -> Rect {
+    let [x, y, w, h] = r.unwrap_or_default();
+    Rect::from_min_max(map.to_screen([x, y]), map.to_screen([x + w, y + h]))
+}
+
+/// Put a rendered frame on screen: CPU pixels go into an egui texture, averaged down by `minify`
+/// (see [`minify_factor`]); GPU frames are drawn straight from their wgpu texture (registered with
+/// egui-wgpu, no readback).
+pub(super) fn show_frame(app: &mut EffectcraftApp, ctx: &egui::Context, key: crate::frames::FrameKey, img: crate::frames::FrameImage, minify: usize) {
+    use crate::frames::FrameImage;
+    // Settings ▸ Previews ▸ Viewer Zoom Quality.
+    let smooth = app.session.prefs.viewer_zoom_smooth();
+    let opts = zoom_texture_options(smooth);
+    match img {
+        FrameImage::Cpu(img) => {
+            // Frames wider or taller than the GPU's texture limit go up averaged down too (#201).
+            let max = crate::frames::max_texture_side(ctx);
+            let fitted = crate::frames::fit_shared_texture_by(&img, max, minify);
+            match &mut app.viewer_tex {
+                Some((tex, k, m)) if tex.size() == fitted.size() => {
+                    tex.set(fitted, opts);
+                    (*k, *m) = (key, minify);
+                }
+                _ => app.viewer_tex = Some((ctx.load_texture("viewer-frame", fitted, opts), key, minify)),
+            }
+            app.viewer_shown = app.viewer_tex.as_ref().map(|(t, k, _)| (t.id(), *k));
+            app.viewer_image = Some(img);
+            vt::set_texture_roi(ctx, app.session.state.region_of_interest.or(app.ui.viewer.extended));
+        }
+        FrameImage::Gpu(f) => {
+            let Some(rs) = &app.wgpu else { return };
+            let view = f.texture.create_view(&Default::default());
+            let mut ren = rs.renderer.write();
+            let id = match &app.viewer_native {
+                Some((id, _, _)) => {
+                    ren.update_egui_texture_from_wgpu_texture_with_sampler_options(&rs.device, &view, zoom_sampler(smooth), *id);
+                    *id
+                }
+                None => ren.register_native_texture_with_sampler_options(&rs.device, &view, zoom_sampler(smooth)),
+            };
+            drop(ren);
+            app.viewer_native = Some((id, key, f));
+            app.viewer_shown = Some((id, key));
+            // Pixels are read back on demand (viewer_pixels).
+            app.viewer_image = None;
+        }
+    }
+}
diff --git a/crates/ui-egui/src/panels/viewer/geometry.rs b/crates/ui-egui/src/panels/viewer/geometry.rs
new file mode 100644
index 000000000..847332bcf
--- /dev/null
+++ b/crates/ui-egui/src/panels/viewer/geometry.rs
@@ -0,0 +1,304 @@
+use super::{CameraState, Comp, EffectcraftApp, EvalCtx, Layer, LayerId, Mat3, Pos2, VIEW_CAM, gv2, three_d, vec2};
+
+/// The camera the viewer shows (view camera or the comp's active camera).
+pub(super) fn cam_state(ctx: &EvalCtx) -> CameraState {
+    VIEW_CAM.with(|c| c.get()).unwrap_or_else(|| three_d::active_camera(ctx))
+}
+
+/// Layer → comp (viewer) matrix through the current 3D view.
+pub(crate) fn l2c(ctx: &EvalCtx, layer: &Layer) -> (Mat3, f64) {
+    match VIEW_CAM.with(|c| c.get()) {
+        Some(cam) if layer.is_3d() => (three_d::layer_to_view(ctx, layer, &cam), 0.0),
+        _ => ctx.layer_to_comp(layer),
+    }
+}
+
+/// `l2c` (layer → comp) applied from effect space instead: effect points and Puppet pins,
+/// measured from the top-left of the layer's effect bounds (see `effect_bounds`).
+pub(crate) fn from_effect_space(ctx: &EvalCtx, layer: &Layer, l2c: Mat3) -> Mat3 {
+    let o = ctx.effect_bounds(layer).1;
+    l2c * Mat3::translate(gv2(o[0], o[1]))
+}
+
+/// Effect space → comp (viewer) matrix through the current 3D view.
+pub(crate) fn fx2c(ctx: &EvalCtx, layer: &Layer) -> Mat3 {
+    from_effect_space(ctx, layer, l2c(ctx, layer).0)
+}
+
+/// The selected, unlocked layers of `comp` other than `layer` (when `layer` is one of them): a
+/// handle or Rotation tool drag on one changes them all.
+pub(super) fn selected_others<'a>(app: &EffectcraftApp, comp: &'a Comp, layer: LayerId) -> Vec<&'a Layer> {
+    let sel = &app.session.state.selected_layers;
+    if !sel.contains(&layer) {
+        return vec![];
+    }
+    sel.iter().filter(|id| **id != layer).filter_map(|id| comp.layer(*id)).filter(|l| !l.switches.locked && l.transform().is_some()).collect()
+}
+
+/// The least homogeneous depth (`w`: the distance in front of a perspective camera in pixels, 1
+/// for 2D layers and orthographic views) a viewer outline is drawn at: points at or behind the
+/// camera would flip through infinity and draw long lines across the viewer (#572).
+const NEAR_W: f64 = 0.5;
+
+/// `p` through the homography `m` before the perspective divide: (x, y, w).
+fn homogeneous(m: &Mat3, p: [f64; 2]) -> [f64; 3] {
+    let r = |i: usize| m.0.get(i).map_or(0.0, |row| row[0] * p[0] + row[1] * p[1] + row[2]);
+    [r(0), r(1), r(2)]
+}
+
+/// The closed polygon `poly` (layer pixels) through `m`, clipped to the part in front of the
+/// camera's near plane (comp pixels; empty when none of it is).
+pub(super) fn project_clipped(m: &Mat3, poly: &[[f64; 2]]) -> Vec<[f64; 2]> {
+    let h: Vec<[f64; 3]> = poly.iter().map(|p| homogeneous(m, *p)).collect();
+    let mut out = vec![];
+    for (i, a) in h.iter().enumerate() {
+        let Some(b) = h.get((i + 1) % h.len()) else { continue };
+        let (ina, inb) = (a[2] >= NEAR_W, b[2] >= NEAR_W);
+        if ina {
+            out.push(*a);
+        }
+        if ina != inb {
+            let t = (NEAR_W - a[2]) / (b[2] - a[2]);
+            out.push([a[0] + (b[0] - a[0]) * t, a[1] + (b[1] - a[1]) * t, NEAR_W]);
+        }
+    }
+    out.iter().map(|q| [q[0] / q[2], q[1] / q[2]]).filter(|q| q[0].is_finite() && q[1].is_finite()).collect()
+}
+
+/// The segment a → b (world space) through the projection `pc`, clipped at the near plane.
+pub(super) fn project_segment(
+    pc: &effectcraft_engine::geom::Mat4,
+    a: effectcraft_engine::geom::Vec3,
+    b: effectcraft_engine::geom::Vec3,
+) -> Option<[[f64; 2]; 2]> {
+    let h = |p: effectcraft_engine::geom::Vec3| {
+        let r = |i: usize| pc.0.get(i).map_or(0.0, |row| row[0] * p.x + row[1] * p.y + row[2] * p.z + row[3]);
+        [r(0), r(1), r(3)]
+    };
+    let (mut ha, mut hb) = (h(a), h(b));
+    if ha[2] < NEAR_W && hb[2] < NEAR_W {
+        return None;
+    }
+    let cut = |p: [f64; 3], q: [f64; 3]| {
+        let t = (NEAR_W - p[2]) / (q[2] - p[2]);
+        [p[0] + (q[0] - p[0]) * t, p[1] + (q[1] - p[1]) * t, NEAR_W]
+    };
+    if ha[2] < NEAR_W {
+        ha = cut(ha, hb);
+    } else if hb[2] < NEAR_W {
+        hb = cut(hb, ha);
+    }
+    let d = |q: [f64; 3]| [q[0] / q[2], q[1] / q[2]];
+    let s = [d(ha), d(hb)];
+    s.iter().flatten().all(|v| v.is_finite()).then_some(s)
+}
+
+/// The content box corners (layer pixels) of `layer`.
+pub(super) fn box_corners(b: [f64; 4]) -> [[f64; 2]; 4] {
+    [[b[0], b[1]], [b[2], b[1]], [b[2], b[3]], [b[0], b[3]]]
+}
+
+/// Layer → comp matrix and its bounds quad (in comp pixels). None for a 3D layer reaching to or
+/// behind the camera (its quad would flip; [`layer_outline`] draws the part in front).
+pub(crate) fn layer_quad(ctx: &EvalCtx, layer: &Layer) -> Option<(Mat3, [[f64; 2]; 4], [f64; 4])> {
+    let b = effectcraft_engine::render::content_bounds(ctx, layer)?;
+    let (m, _) = l2c(ctx, layer);
+    let corners = box_corners(b);
+    if corners.iter().any(|p| homogeneous(&m, *p)[2] < NEAR_W) {
+        return None;
+    }
+    let pts = corners.map(|p| {
+        let q = m.apply(gv2(p[0], p[1]));
+        [q.x, q.y]
+    });
+    Some((m, pts, b))
+}
+
+/// The outline of a layer's content box in comp pixels, clipped at the camera's near plane.
+pub(crate) fn layer_outline(ctx: &EvalCtx, layer: &Layer) -> Vec<[f64; 2]> {
+    let Some(b) = effectcraft_engine::render::content_bounds(ctx, layer) else { return vec![] };
+    project_clipped(&l2c(ctx, layer).0, &box_corners(b))
+}
+
+/// Which axes a bounding-box handle scales: corners (0–3) both; the top and bottom edges (4, 6)
+/// y; the right and left edges (5, 7) x.
+pub(super) fn handle_axes(handle: usize) -> [bool; 2] {
+    match handle {
+        4 | 6 => [false, true],
+        5 | 7 => [true, false],
+        _ => [true, true],
+    }
+}
+
+/// A bounding-box handle's point in layer pixels (`b`: the content box; handles as in
+/// [`handle_axes`], the corners clockwise from the top left, then the top, right, bottom and
+/// left edges' midpoints).
+pub(super) fn handle_point(b: [f64; 4], handle: usize) -> [f64; 2] {
+    let (cx, cy) = ((b[0] + b[2]) / 2.0, (b[1] + b[3]) / 2.0);
+    match handle {
+        0 => [b[0], b[1]],
+        1 => [b[2], b[1]],
+        2 => [b[2], b[3]],
+        3 => [b[0], b[3]],
+        4 => [cx, b[1]],
+        5 => [b[2], cy],
+        6 => [cx, b[3]],
+        _ => [b[0], cy],
+    }
+}
+
+/// The resize cursor over bounding-box handle `handle` of the on-screen box `sq` (corners
+/// clockwise from the top left, handles as in [`handle_point`]): along the direction the handle
+/// scales, so it turns with the layer, as in After Effects. A corner points between its two
+/// edges (the box's diagonal whatever its proportions), an edge handle across its edge.
+pub(super) fn handle_cursor(sq: &[Pos2], handle: usize) -> egui::CursorIcon {
+    let at = |k: usize| sq.get(k % 4).copied().unwrap_or(Pos2::ZERO);
+    let dir = if handle < 4 {
+        let c = at(handle);
+        (c - at(handle + 3)).normalized() + (c - at(handle + 1)).normalized()
+    } else {
+        let e = at(handle - 3) - at(handle - 4);
+        vec2(-e.y, e.x)
+    };
+    // Screen y points down: 45° is the south-east diagonal.
+    let a = dir.y.atan2(dir.x).to_degrees().rem_euclid(180.0);
+    if !(22.5..157.5).contains(&a) {
+        egui::CursorIcon::ResizeHorizontal
+    } else if a < 67.5 {
+        egui::CursorIcon::ResizeNwSe
+    } else if a < 112.5 {
+        egui::CursorIcon::ResizeVertical
+    } else {
+        egui::CursorIcon::ResizeNeSw
+    }
+}
+
+/// The scale ratio (x, y) that puts the point grabbed at `start` (relative to the anchor, layer
+/// pixels) under the pointer at `cur`. `uniform` (Shift on a corner) keeps the aspect ratio,
+/// following the pointer along the handle's diagonal. Dragging past the anchor flips the layer,
+/// as in After Effects; an axis whose grabbed point sits on the anchor keeps its scale.
+pub(super) fn drag_ratio(start: [f64; 2], cur: [f64; 2], axes: [bool; 2], uniform: bool) -> [f64; 2] {
+    if uniform {
+        let d2 = start[0] * start[0] + start[1] * start[1];
+        let f = if d2 > 1e-6 { (cur[0] * start[0] + cur[1] * start[1]) / d2 } else { 1.0 };
+        return [f, f];
+    }
+    [0, 1].map(|k| if axes[k] && start[k].abs() > 1e-3 { cur[k] / start[k] } else { 1.0 })
+}
+
+/// Snap a handle drag (#252): the handle (`h`, layer pixels from the anchor point `a` as the
+/// drag began; `l2c` that layer space → comp) at scale ratio `f` goes through `snap` (a comp
+/// point → its correction), and the ratio that puts the handle where it snapped comes back.
+/// A `uniform` drag slides the handle along its line from the anchor point to the nearer snapped
+/// line; otherwise each scaled axis takes the snapped point.
+pub(super) fn snap_handle(
+    f: [f64; 2],
+    h: [f64; 2],
+    a: [f64; 2],
+    l2c: &Mat3,
+    axes: [bool; 2],
+    uniform: bool,
+    snap: impl FnOnce([f64; 2]) -> [f64; 2],
+) -> [f64; 2] {
+    let at = |f: [f64; 2]| {
+        let q = l2c.apply(gv2(a[0] + f[0] * h[0], a[1] + f[1] * h[1]));
+        [q.x, q.y]
+    };
+    let p = at(f);
+    let c = snap(p);
+    let s = [p[0] + c[0], p[1] + c[1]];
+    if uniform {
+        let o = at([0.0; 2]);
+        let d = [p[0] - o[0], p[1] - o[1]];
+        let k = [0, 1].into_iter().filter(|k| c[*k] != 0.0 && d[*k].abs() > 1e-9).min_by(|x, y| c[*x].abs().total_cmp(&c[*y].abs()));
+        return k.map_or(f, |k| f.map(|v| v * (s[k] - o[k]) / d[k]));
+    }
+    let Some(inv) = l2c.inverse().filter(|_| c != [0.0; 2]) else { return f };
+    let q = inv.apply(gv2(s[0], s[1]));
+    let q = [q.x - a[0], q.y - a[1]];
+    [0, 1].map(|k| if axes[k] && h[k].abs() > 1e-9 { q[k] / h[k] } else { f[k] })
+}
+
+/// The turn from angle `from` to angle `to` (degrees), wrapped to (−180°, 180°]: the shortest way
+/// round, so summing it frame by frame follows the pointer across atan2's ±180° seam and past full
+/// revolutions. Non-finite input turns by nothing.
+pub(super) fn turn_delta(from: f64, to: f64) -> f64 {
+    let d = to - from;
+    if !d.is_finite() {
+        return 0.0;
+    }
+    let w = (d + 180.0).rem_euclid(360.0) - 180.0;
+    if w <= -180.0 { w + 360.0 } else { w }
+}
+
+/// The Rotation tool's value: the rotation as the drag began plus the turn so far (which may span
+/// revolutions), snapped to 45° steps with Shift.
+pub(super) fn rotate_value(start_rot: f64, turned: f64, shift: bool) -> f64 {
+    let r = start_rot + turned;
+    let r = if r.is_finite() { r } else { start_rot };
+    if shift { (r / 45.0).round() * 45.0 } else { r }
+}
+
+/// A drag `d` (comp pixels), kept to the axis it moves along most when `shift` is held.
+pub(super) fn one_axis(d: [f64; 2], shift: bool) -> [f64; 2] {
+    if !shift {
+        d
+    } else if d[0].abs() > d[1].abs() {
+        [d[0], 0.0]
+    } else {
+        [0.0, d[1]]
+    }
+}
+
+pub(super) fn point_in_quad(p: [f64; 2], q: &[[f64; 2]; 4]) -> bool {
+    let mut sign = 0.0;
+    for i in 0..4 {
+        let a = q[i];
+        let b = q[(i + 1) % 4];
+        let c = (b[0] - a[0]) * (p[1] - a[1]) - (b[1] - a[1]) * (p[0] - a[0]);
+        if c.abs() < 1e-9 {
+            continue;
+        }
+        if sign == 0.0 {
+            sign = c.signum();
+        } else if c.signum() != sign {
+            return false;
+        }
+    }
+    true
+}
+
+/// Separating-axis test: a marquee may cross a layer without containing any corner.
+pub(super) fn quad_intersects_box(q: &[[f64; 2]; 4], a: [f64; 2], b: [f64; 2]) -> bool {
+    if q.iter().flatten().chain(a.iter()).chain(b.iter()).any(|v| !v.is_finite()) {
+        return false;
+    }
+    let lo = [a[0].min(b[0]), a[1].min(b[1])];
+    let hi = [a[0].max(b[0]), a[1].max(b[1])];
+    let rect = [lo, [hi[0], lo[1]], hi, [lo[0], hi[1]]];
+    let axes = [[1.0, 0.0], [0.0, 1.0]].into_iter().chain((0..4).map(|i| {
+        let j = (i + 1) % 4;
+        [q[j][1] - q[i][1], q[i][0] - q[j][0]]
+    }));
+    for axis in axes {
+        let project = |p: &[f64; 2]| p[0] * axis[0] + p[1] * axis[1];
+        let (qmin, qmax) = q.iter().map(project).fold((f64::INFINITY, f64::NEG_INFINITY), |(lo, hi), v| (lo.min(v), hi.max(v)));
+        let (rmin, rmax) = rect.iter().map(project).fold((f64::INFINITY, f64::NEG_INFINITY), |(lo, hi), v| (lo.min(v), hi.max(v)));
+        if qmax < rmin || rmax < qmin {
+            return false;
+        }
+    }
+    true
+}
+
+/// Parent-space linear inverse (to convert a comp-space drag delta into a position delta).
+pub(super) fn parent_inverse(ctx: &EvalCtx, layer: &Layer) -> Mat3 {
+    match layer.parent.and_then(|p| ctx.comp.layer(p)) {
+        Some(p) => {
+            let w = ctx.world_matrix(p);
+            let m = Mat3([[w.0[0][0], w.0[0][1], 0.0], [w.0[1][0], w.0[1][1], 0.0], [0.0, 0.0, 1.0]]);
+            m.inverse().unwrap_or(Mat3::IDENTITY)
+        }
+        None => Mat3::IDENTITY,
+    }
+}
diff --git a/crates/ui-egui/src/panels/viewer/gesture.rs b/crates/ui-egui/src/panels/viewer/gesture.rs
new file mode 100644
index 000000000..db024e720
--- /dev/null
+++ b/crates/ui-egui/src/panels/viewer/gesture.rs
@@ -0,0 +1,197 @@
+use super::{EffectcraftApp, LayerId, Mat3, Pos2, Rect, Tick, Tool, ViewerMap, ov, vec2};
+
+/// What a drag in the viewer is doing.
+#[derive(Clone, Debug)]
+pub(super) enum Gesture {
+    /// Per layer: start position and the parent-space change per comp pixel of drag in x and y.
+    Move {
+        layers: Vec<(LayerId, [f64; 3], [f64; 3], [f64; 3])>,
+        start: [f64; 2],
+        /// The grabbed layer's feature nearest the pointer (comp px at the start): it snaps.
+        snap_src: Option<[f64; 2]>,
+    },
+    Camera {
+        tool: Tool,
+    },
+    /// A bounding-box handle: scales about the anchor point so the grabbed point follows the
+    /// pointer (corners both axes, edges one), relative to the layer as the drag began; the
+    /// handle snaps.
+    Scale {
+        layer: LayerId,
+        start_scale: [f64; 3],
+        /// The grabbed point relative to the anchor, in layer pixels.
+        start_local: [f64; 2],
+        /// The handle's point relative to the anchor, in layer pixels.
+        handle: [f64; 2],
+        anchor: [f64; 2],
+        axes: [bool; 2],
+        /// Layer pixels → comp as the drag began, and its inverse.
+        l2c: Mat3,
+        inv: Mat3,
+        /// The other selected layers and their scales as the drag began: they scale by the same
+        /// ratio about their own anchor points, as in After Effects (#491).
+        others: Vec<(LayerId, [f64; 3])>,
+    },
+    Rotate {
+        layer: LayerId,
+        center: Pos2,
+        /// The pointer's angle about the centre on the last frame (degrees, as atan2 gives it).
+        last_angle: f64,
+        /// The turn so far, summed frame by frame so it keeps counting past a full revolution in
+        /// either direction (After Effects: 1x +0.0°, −1x −90.0°…) instead of wrapping at ±180°.
+        turned: f64,
+        start_rot: f64,
+        /// The other selected layers and their rotations: they turn by the same angle.
+        others: Vec<(LayerId, f64)>,
+    },
+    Anchor {
+        layer: LayerId,
+        start_anchor: [f64; 3],
+        start_pos: [f64; 3],
+        start: [f64; 2],
+        inv: Mat3,
+        l2p: Mat3,
+        /// The layer's own snap targets as the drag began (its box and path vertices).
+        own: Vec<effectcraft_engine::viewer::SnapTarget>,
+        /// Alt held as the drag began: the anchor point moves alone, so the layer shifts.
+        anchor_only: bool,
+    },
+    Pan {
+        start_pan: [f32; 2],
+    },
+    Create {
+        tool: Tool,
+        start: [f64; 2],
+    },
+    Marquee {
+        start: Pos2,
+    },
+    /// Dragging selected mask / shape path vertices: press point, the grabbed vertex (comp px,
+    /// it snaps), the comp-space move applied so far and comp → path space.
+    Vertices {
+        start: [f64; 2],
+        src: [f64; 2],
+        applied: [f64; 2],
+        inv: Mat3,
+        layer: LayerId,
+    },
+    /// Dragging a vertex's Bezier tangent (both sides symmetric unless Alt breaks them).
+    Tangent {
+        layer: LayerId,
+        mask: u64,
+        index: usize,
+        out: bool,
+        vertex: [f64; 2],
+        inv: Mat3,
+    },
+    /// Dragging a Puppet pin (comp → layer matrix inverse).
+    PuppetPin {
+        layer: LayerId,
+        pin: u64,
+        inv: Mat3,
+    },
+    /// Rotating an Advanced / Bend pin by its ring: the pin's screen centre, the pointer's last
+    /// angle (radians) and the rotation so far (°, accumulated so it can pass a full turn).
+    PuppetRotate {
+        layer: LayerId,
+        pin: u64,
+        center: Pos2,
+        last: f32,
+        rotation: f64,
+    },
+    /// Scaling an Advanced / Bend pin by its square: the pin's screen centre, the press distance
+    /// from it and the scale at the press (1 = 100 %).
+    PuppetScale {
+        layer: LayerId,
+        pin: u64,
+        center: Pos2,
+        start: f32,
+        scale: f64,
+    },
+    /// Puppet tools: a marquee selecting pins (dragged outside the layer's art, or Alt-dragged).
+    PinMarquee {
+        start: Pos2,
+    },
+    /// Object Matte tool: a box around the object (screen point where the drag began).
+    ObjectMatteBox {
+        start: Pos2,
+    },
+    /// Puppet tool Record mode (⌘/Ctrl-drag a pin): the drag is sampled in real time (seconds
+    /// since it began, effect space) and becomes keyframes on release (`puppet.recordPin`); the
+    /// current time runs along while recording.
+    PuppetRecord {
+        layer: LayerId,
+        pin: u64,
+        /// Other selected pins of the layer, moving with the dragged one.
+        others: Vec<u64>,
+        inv: Mat3,
+        began: f64,
+        cti: Tick,
+        samples: Vec<(f64, [f64; 2])>,
+    },
+    /// Pen tool: pulling the tangents of the vertex just placed.
+    Pen {
+        layer: LayerId,
+        mask: u64,
+        index: usize,
+        vertex: [f64; 2],
+        inv: Mat3,
+        press: Pos2,
+    },
+    /// Dragging a track point's feature/search region, a corner or its attach point.
+    Track {
+        layer: LayerId,
+        tracker: u64,
+        drag: crate::panels::tracker::Drag,
+    },
+    /// Motion paths, free transform, Mask Feather, guides and the region of interest
+    /// (`viewer_overlays`).
+    Overlay(ov::Drag),
+}
+
+/// Pen tool path in progress: (layer, mask uid).
+pub(super) fn pen_id() -> egui::Id {
+    egui::Id::unique("viewer-pen")
+}
+
+pub(super) const HANDLE: f32 = 7.0;
+
+/// How close (screen points) the pointer must be to a path vertex or tangent handle to grab it.
+const VERTEX_GRAB: f32 = 6.0;
+
+/// The reach of a path vertex at `pos` (#1042): a vertex marker sitting under, or just beside, a
+/// bounding-box handle would lose the press to the handle (the handle reaches further than the
+/// vertex), so wherever a box handle is in range the vertex reaches as far as the handle does.
+/// Vertices then win in the handle's whole zone, as in After Effects.
+pub(super) fn vertex_grab_radius(pos: Pos2, handles: impl IntoIterator<Item = Pos2>) -> f32 {
+    if handles.into_iter().any(|h| h.distance(pos) < HANDLE + 2.0) { HANDLE + 2.0 } else { VERTEX_GRAB }
+}
+
+/// Shown when a Roto Brush tool is used in the Composition panel (#753).
+pub(super) const ROTO_HINT: &str = "The Roto Brush works in the Layer panel. Double-click the layer to open it.";
+
+/// Region of interest handles on screen: corners (0–3, clockwise from top-left) then edge
+/// midpoints (4 top, 5 right, 6 bottom, 7 left).
+pub(super) fn roi_handles(r: Rect) -> [Pos2; 8] {
+    [r.left_top(), r.right_top(), r.right_bottom(), r.left_bottom(), r.center_top(), r.right_center(), r.center_bottom(), r.left_center()]
+}
+
+/// A drag starting on a region of interest handle: the ROI redrawn from the opposite corner (or
+/// edge, with the other axis kept).
+pub(super) fn roi_drag(app: &EffectcraftApp, map: &ViewerMap, comp_rect: Rect, zoom: f32, press: Pos2) -> Option<ov::Drag> {
+    let [rx, ry, rw, rh] = app.session.state.region_of_interest?;
+    let r = Rect::from_min_size(comp_rect.min + vec2(rx as f32 * zoom, ry as f32 * zoom), vec2(rw as f32 * zoom, rh as f32 * zoom));
+    let i = roi_handles(r).iter().position(|h| h.distance(press) < 6.0)?;
+    let (x0, y0, x1, y1) = (rx, ry, rx + rw, ry + rh);
+    let _ = map;
+    Some(match i {
+        0 => ov::Drag::Roi { start: [x1, y1], keep: [None, None] },
+        1 => ov::Drag::Roi { start: [x0, y1], keep: [None, None] },
+        2 => ov::Drag::Roi { start: [x0, y0], keep: [None, None] },
+        3 => ov::Drag::Roi { start: [x1, y0], keep: [None, None] },
+        4 => ov::Drag::Roi { start: [x1, y1], keep: [Some(x0), None] },
+        5 => ov::Drag::Roi { start: [x0, y0], keep: [None, Some(y1)] },
+        6 => ov::Drag::Roi { start: [x0, y0], keep: [Some(x1), None] },
+        _ => ov::Drag::Roi { start: [x1, y0], keep: [None, Some(y1)] },
+    })
+}
diff --git a/crates/ui-egui/src/panels/viewer/shapes.rs b/crates/ui-egui/src/panels/viewer/shapes.rs
new file mode 100644
index 000000000..395219a05
--- /dev/null
+++ b/crates/ui-egui/src/panels/viewer/shapes.rs
@@ -0,0 +1,221 @@
+use super::geometry::{l2c, layer_quad, point_in_quad};
+use super::{
+    Color32, Comp, EffectcraftApp, EvalCtx, Layer, LayerId, LayerSource, Mat3, PaintKind, Pos2, Rect, Stroke, Tick, Tokens, Tool, ViewerMap, gv2, json, ov,
+    pos2,
+};
+
+/// Visible, unlocked layers eligible for viewer hit tests, in front-to-back order.
+/// Solo scope matches the renderer: any soloed AV layer activates it at every time (as in After
+/// Effects), even when hidden, locked or outside its in-out range.
+pub(crate) fn selectable_layers(comp: &Comp, time: Tick) -> impl Iterator<Item = &Layer> {
+    let any_solo = comp.layers.iter().any(|l| l.switches.solo && l.source.is_av());
+    comp.layers
+        .iter()
+        .filter(move |l| l.is_active_at(time) && l.switches.video && !l.switches.locked && !l.is_camera() && !l.is_light() && (!any_solo || l.switches.solo))
+}
+
+/// Selectable layers under a comp point, front to back.
+pub(crate) fn layers_at<'a, 'b>(ectx: &'b EvalCtx<'a>, cpt: [f64; 2]) -> impl Iterator<Item = &'a Layer> + 'b {
+    selectable_layers(ectx.comp, ectx.time).filter(move |l| layer_quad(ectx, l).is_some_and(|(_, q, _)| point_in_quad(cpt, &q)))
+}
+
+/// Topmost selectable layer under a comp point.
+pub(crate) fn layer_at<'a>(ectx: &EvalCtx<'a>, cpt: [f64; 2]) -> Option<&'a Layer> {
+    layers_at(ectx, cpt).next()
+}
+
+/// The layer a press at a comp point acts on, selected (Shift toggles the topmost layer). As in
+/// After Effects, a selected layer under the point comes before the layers in front of it, so it
+/// can be dragged where they cover it; otherwise the topmost layer (#230).
+pub(crate) fn pick(app: &mut EffectcraftApp, ectx: &EvalCtx, cpt: [f64; 2], toggle: bool) -> Option<LayerId> {
+    if toggle {
+        let hit = layer_at(ectx, cpt)?.id;
+        let _ = app.session.execute("layer.select", json!({"layers": [hit.0], "toggle": true}));
+        return Some(hit);
+    }
+    let selected = &app.session.state.selected_layers;
+    let hits: Vec<LayerId> = layers_at(ectx, cpt).map(|l| l.id).collect();
+    let hit = *hits.iter().find(|id| selected.contains(id)).or(hits.first())?;
+    if !selected.contains(&hit) {
+        let _ = app.session.execute("layer.select", json!({"layers": [hit.0]}));
+    }
+    Some(hit)
+}
+
+/// Where a shape drag is going to land: a mask on the selected layer, a group inside it, or a new
+/// shape layer.
+#[derive(Clone, Copy, PartialEq, Eq)]
+enum ShapeTarget {
+    Mask,
+    IntoLayer,
+    NewLayer,
+}
+
+impl ShapeTarget {
+    /// What the drag will make and where, named the way the ghost captions it.
+    fn label(self, layer_name: &str) -> String {
+        match self {
+            ShapeTarget::Mask => format!("Mask on “{layer_name}”"),
+            ShapeTarget::IntoLayer => format!("Into “{layer_name}”"),
+            ShapeTarget::NewLayer => "New shape layer".to_string(),
+        }
+    }
+}
+
+/// A shape drag as it stands, after the Tools' normalisations: the path it will make and where it
+/// will land.
+pub(super) struct ShapeDrag {
+    /// The `shape.newShape` / `layer.addMask` kind for the tool.
+    kind: &'static str,
+    /// Comp-space centre and size, what the drag will make.
+    centre: [f64; 2],
+    size: [f64; 2],
+    target: ShapeTarget,
+    /// The selected layer's name and the index its next mask would take, for the ghost's caption
+    /// and colour.
+    layer_name: String,
+    mask_index: usize,
+}
+
+/// The kind `tool` draws, as `shape.newShape` / `layer.addMask` name it.
+fn shape_kind(tool: Tool) -> &'static str {
+    match tool {
+        Tool::Rectangle => "rect",
+        Tool::RoundedRect => "rounded",
+        Tool::Ellipse => "ellipse",
+        Tool::Polygon => "polygon",
+        _ => "star",
+    }
+}
+
+/// What a shape tool drag from `start` to `end` makes, or `None` while it is too small to make
+/// anything. Alt (Option) draws from the press point and Shift squares the box; the live ghost and
+/// [`create_shape`] both go through this, so the drag always shows what it will commit.
+pub(super) fn shape_drag(app: &EffectcraftApp, tool: Tool, start: [f64; 2], end: [f64; 2], mods: egui::Modifiers) -> Option<ShapeDrag> {
+    let comp = app.session.active_comp()?;
+    let selected = app.session.state.selected_layers.first().copied();
+    let sel = selected.and_then(|id| comp.layer(id));
+    // A footage, solid or other non-shape layer selected, or a shape layer with Tool Creates
+    // Mask: a mask on that layer. Otherwise the engine's own target: the first selected unlocked
+    // shape layer, else a new one.
+    let target = match sel {
+        Some(l) if l.source.is_av() && (app.session.state.shape_tool.creates_mask || !matches!(l.source, LayerSource::Shape)) => (ShapeTarget::Mask, Some(l)),
+        _ => match effectcraft_engine::commands::shape_tool::selected_shape_target(&app.session, comp).and_then(|id| comp.layer(id)) {
+            Some(l) => (ShapeTarget::IntoLayer, Some(l)),
+            None => (ShapeTarget::NewLayer, None),
+        },
+    };
+    let (target, layer) = target;
+    let mask_index = if target == ShapeTarget::Mask { layer.and_then(|l| l.masks()).map_or(0, |m| m.groups().count()) } else { 0 };
+    let (mut w, mut h) = ((end[0] - start[0]).abs(), (end[1] - start[1]).abs());
+    // Ctrl/Cmd draws from the press point as the centre, as in After Effects.
+    if mods.command {
+        w *= 2.0;
+        h *= 2.0;
+    }
+    if w < 2.0 && h < 2.0 {
+        return None;
+    }
+    if mods.shift {
+        let m = w.max(h);
+        w = m;
+        h = m;
+    }
+    Some(ShapeDrag {
+        kind: shape_kind(tool),
+        centre: if mods.command { start } else { [start[0].min(end[0]) + w / 2.0, start[1].min(end[1]) + h / 2.0] },
+        size: [w, h],
+        target,
+        layer_name: layer.map_or_else(String::new, |l| l.name.clone()),
+        mask_index,
+    })
+}
+
+/// The Tools bar's paint colour as bytes, dimmed by `alpha` so the comp shows through the ghost.
+fn paint_rgb(c: [f32; 3], opacity: f64, alpha: f32) -> Color32 {
+    let f = |k: f32| (k.clamp(0.0, 1.0) * 255.0).round() as u8;
+    Color32::from_rgb(f(c[0]), f(c[1]), f(c[2])).gamma_multiply((opacity.clamp(0.0, 100.0) / 100.0) as f32 * alpha)
+}
+
+/// Draw a shape drag as it will land: the tool's own path, filled with the Tools bar's Fill and
+/// outlined in its Stroke (or the mask colour, for a mask), captioned with where it goes.
+pub(super) fn draw_shape_ghost(painter: &egui::Painter, map: &ViewerMap, app: &EffectcraftApp, d: &ShapeDrag, t: &Tokens) {
+    // The engine's own geometry for the kind, so the ghost is the shape and not a stand-in for it.
+    let Some(sp) = effectcraft_engine::commands::shape_tool::mask_path(d.kind, d.centre, d.size) else { return };
+    let mut pts = ov::flatten(&sp, &Mat3::IDENTITY, map);
+    if pts.first() == pts.last() {
+        pts.pop();
+    }
+    if pts.len() < 3 {
+        return;
+    }
+    let tool = &app.session.state.shape_tool;
+    let (fill, line) = match d.target {
+        ShapeTarget::Mask => {
+            let [r, g, b] = effectcraft_engine::prefs::mask_color(app.session.prefs.appearance.cycle_mask_colors, d.mask_index);
+            (Color32::from_rgb(r, g, b).gamma_multiply(0.25), Color32::from_rgb(r, g, b))
+        }
+        _ => {
+            let stroke_on = tool.stroke.kind != PaintKind::None && tool.stroke_width > 0.0;
+            (
+                if tool.fill.kind == PaintKind::None { Color32::TRANSPARENT } else { paint_rgb(tool.fill.color, tool.fill.opacity, 0.45) },
+                if stroke_on { paint_rgb(tool.stroke.color, tool.stroke.opacity, 1.0) } else { t.accent },
+            )
+        }
+    };
+    let Some(bounds) = bounds_of(&pts) else { return };
+    // A screen-width outline reads at every zoom, where a comp-pixel hairline does not.
+    painter.add(egui::Shape::Path(egui::epaint::PathShape { points: pts, closed: true, fill, stroke: Stroke::new(1.5, line).into() }));
+    // Caption it with where the shape lands: a mask, a group in the selected shape layer or a
+    // new layer.
+    let font = Tokens::ui(11.0);
+    let galley = painter.layout_no_wrap(d.target.label(&d.layer_name), font, line);
+    let caption = Rect::from_min_size(pos2(bounds.left(), bounds.top() - 5.0 - galley.size().y), galley.size());
+    painter.rect_filled(caption.expand(3.0), 2.0, Color32::from_black_alpha(150));
+    painter.galley(caption.min, galley, line);
+}
+
+/// The bounds of points on screen, or `None` for an empty set.
+fn bounds_of(pts: &[Pos2]) -> Option<Rect> {
+    let first = *pts.first()?;
+    let mut r = Rect::from_min_max(first, first);
+    for p in pts.iter().skip(1) {
+        r.extend_with(*p);
+    }
+    Some(r)
+}
+
+pub(super) fn create_shape(app: &mut EffectcraftApp, tool: Tool, a: [f64; 2], b: [f64; 2], mods: egui::Modifiers) {
+    let Some(d) = shape_drag(app, tool, a, b, mods) else { return };
+    let (kind, (w, h), (cx, cy)) = (d.kind, (d.size[0], d.size[1]), (d.centre[0], d.centre[1]));
+    // A mask on the selected layer, as the ghost showed.
+    if d.target == ShapeTarget::Mask {
+        // In layer space: invert the layer transform.
+        let sel_layer = app.session.state.selected_layers.first().copied().and_then(|id| app.session.active_comp().and_then(|c| c.layer(id)).cloned());
+        if let Some(l) = sel_layer
+            && let Some(comp) = app.session.active_comp_arc()
+        {
+            let ectx = EvalCtx {
+                project: &app.session.project,
+                comp_id: app.session.active_comp_id().unwrap_or_default(),
+                comp: &comp,
+                time: app.session.time(),
+                expr: None,
+                footage: None,
+            };
+            let inv = l2c(&ectx, &l).0.inverse().unwrap_or(Mat3::IDENTITY);
+            let p0 = inv.apply(gv2(cx - w / 2.0, cy - h / 2.0));
+            let p1 = inv.apply(gv2(cx + w / 2.0, cy + h / 2.0));
+            let rect = [p0.x.min(p1.x), p0.y.min(p1.y), (p1.x - p0.x).abs(), (p1.y - p0.y).abs()];
+            if let Err(e) = app.session.execute("layer.addMask", json!({"layer": l.id.0, "shape": kind, "rect": rect})) {
+                app.ui.status = e.to_string();
+            }
+        }
+        return;
+    }
+    // Into the selected shape layer's Contents as a new group (as in After Effects), else a new
+    // shape layer; painted with the Tools bar's Fill and Stroke.
+    if let Err(e) = app.session.execute("shape.newShape", json!({"kind": kind, "size": [w, h], "position": [cx, cy]})) {
+        app.ui.status = e.to_string();
+    }
+}
diff --git a/crates/ui-egui/src/panels/viewer/tests.rs b/crates/ui-egui/src/panels/viewer/tests.rs
new file mode 100644
index 000000000..cb5bffe65
--- /dev/null
+++ b/crates/ui-egui/src/panels/viewer/tests.rs
@@ -0,0 +1,141 @@
+use super::*;
+use effectcraft_engine::geom::{Mat4, vec3};
+
+/// #1544: Shift-clicking with the Pen keeps the new segment horizontal, vertical or diagonal.
+#[test]
+fn pen_shift_click_keeps_the_segment_at_45_degrees() {
+    let near = |a: [f64; 2], b: [f64; 2]| (a[0] - b[0]).abs() < 1e-9 && (a[1] - b[1]).abs() < 1e-9;
+    let from = [100.0, 100.0];
+    assert!(near(constrain_45(from, [104.0, 180.0]), [100.0, 180.0]), "straight down");
+    assert!(near(constrain_45(from, [30.0, 97.0]), [30.0, 100.0]), "left");
+    assert!(near(constrain_45(from, [150.0, 46.0]), [152.0, 48.0]), "up and right, on the diagonal");
+    assert!(near(constrain_45(from, from), from), "on the vertex");
+    assert!(constrain_45(from, [f64::NAN, 3.0])[0].is_nan(), "a non-finite point stays as it is");
+}
+
+/// The Rotation tool counts past a full turn in both directions, as in After Effects: the
+/// pointer going round the anchor 1.5 turns clockwise gives 540°, then back 2 turns gives
+/// −180°, with no jump where atan2 wraps from 180° to −180°.
+#[test]
+fn rotate_tool_accumulates_revolutions() {
+    // Screen y points down, so a growing atan2 angle is clockwise on screen.
+    let drag = |start: f64, steps: &[f64]| {
+        let (mut last, mut turned, mut out) = (start, 0.0, vec![]);
+        for &a in steps {
+            // atan2's range: (−180°, 180°].
+            let a = (a + 180.0).rem_euclid(360.0) - 180.0;
+            turned += turn_delta(last, a);
+            last = a;
+            out.push(turned);
+        }
+        (last, turned, out)
+    };
+    let cw: Vec<f64> = (1..=54).map(|i| i as f64 * 10.0).collect();
+    let (last, turned, seq) = drag(0.0, &cw);
+    assert!((turned - 540.0).abs() < 1e-9, "{turned}");
+    assert!(seq.windows(2).all(|w| (w[1] - w[0] - 10.0).abs() < 1e-9), "no jump: {seq:?}");
+    assert!((rotate_value(0.0, turned, false) - 540.0).abs() < 1e-9);
+    let ccw: Vec<f64> = (1..=72).map(|i| 540.0 - i as f64 * 10.0).collect();
+    let (_, back, seq) = drag(last, &ccw);
+    assert!(seq.windows(2).all(|w| (w[1] - w[0] + 10.0).abs() < 1e-9), "no jump: {seq:?}");
+    let total = turned + back;
+    assert!((total + 180.0).abs() < 1e-9, "{total}");
+    assert!((rotate_value(30.0, total, false) + 150.0).abs() < 1e-9);
+    // Shift snaps the accumulated value, not a wrapped one.
+    assert_eq!(rotate_value(0.0, 400.0, true), 405.0);
+    assert_eq!(rotate_value(0.0, -400.0, true), -405.0);
+    // Across the seam: 170° → −170° is +20°, and back is −20°; exactly half a turn is +180°.
+    assert!((turn_delta(170.0, -170.0) - 20.0).abs() < 1e-9);
+    assert!((turn_delta(-170.0, 170.0) + 20.0).abs() < 1e-9);
+    assert_eq!(turn_delta(0.0, 180.0), 180.0);
+    assert_eq!(turn_delta(0.0, -180.0), 180.0);
+    // Never crash or poison the value on non-finite input.
+    assert_eq!(turn_delta(f64::NAN, 10.0), 0.0);
+    assert_eq!(turn_delta(0.0, f64::INFINITY), 0.0);
+    assert_eq!(rotate_value(15.0, f64::NAN, false), 15.0);
+}
+
+/// #1042: a path vertex lying under, or just beside, a bounding-box handle is grabbed
+/// instead of the handle; away from every handle the reach is unchanged.
+#[test]
+fn vertex_reaches_as_far_as_a_box_handle_over_it() {
+    let handle = pos2(100.0, 100.0);
+    let vertex = pos2(100.0, 100.0);
+    // The press lands 8 points off the vertex, still on the handle's square.
+    let press = pos2(108.0, 100.0);
+    let pick = |p: Pos2, handles: &[Pos2]| vertex.distance(p) < vertex_grab_radius(p, handles.iter().copied());
+    assert!(handle.distance(press) < HANDLE + 2.0, "the handle would take this press");
+    assert!(pick(press, &[handle]), "the vertex wins over the handle");
+    assert!(!pick(press, &[]), "no handle there: the usual reach");
+    assert!(pick(pos2(105.0, 100.0), &[]));
+    assert!(!pick(pos2(120.0, 100.0), &[handle]), "past the handle: nothing");
+}
+
+/// #882: the frame's corner sits on a physical pixel at any display scaling, so 100 % maps
+/// comp pixels 1:1 onto screen pixels.
+#[test]
+fn frame_origin_snaps_to_physical_pixels() {
+    for ppp in [1.0f32, 1.25, 1.5, 1.75, 2.0] {
+        for p in [pos2(-201.12, 72.4), pos2(689.8, 239.75), pos2(0.3, -0.37)] {
+            let s = snap_to_pixels(p, ppp);
+            for v in [s.x * ppp, s.y * ppp] {
+                assert!((v - v.round()).abs() < 1e-3, "ppp {ppp}: {p:?} → {s:?}");
+            }
+            assert!((s - p).length() <= 0.71 / ppp, "moved by at most half a pixel: {p:?} → {s:?}");
+        }
+    }
+    assert_eq!(snap_to_pixels(pos2(1.3, 2.0), 0.0), pos2(1.3, 2.0));
+}
+
+/// #882: a magnified frame shows its pixels as blocks in both Zoom Quality modes; More
+/// Accurate only smooths when the frame is shown smaller.
+#[test]
+fn magnified_frames_are_never_smoothed() {
+    use eframe::wgpu::FilterMode;
+    for smooth in [true, false] {
+        assert_eq!(zoom_texture_options(smooth).magnification, egui::TextureFilter::Nearest);
+        assert_eq!(zoom_sampler(smooth).mag_filter, FilterMode::Nearest);
+    }
+    assert_eq!(zoom_texture_options(true).minification, egui::TextureFilter::Linear);
+    assert_eq!(zoom_sampler(true).min_filter, FilterMode::Linear);
+}
+
+/// A perspective-like homography: w = 100 + y (the plane crosses the camera at y = −100).
+fn tilted() -> Mat3 {
+    Mat3([[100.0, 0.0, 0.0], [0.0, 100.0, 0.0], [0.0, 1.0, 100.0]])
+}
+
+/// #572: a box reaching behind the camera is clipped at the near plane instead of flipping
+/// through infinity into long lines.
+#[test]
+fn outlines_clip_at_the_near_plane() {
+    let m = tilted();
+    let front = project_clipped(&m, &box_corners([-50.0, -50.0, 50.0, 50.0]));
+    assert_eq!(front.len(), 4);
+    let crossing = project_clipped(&m, &box_corners([-50.0, -150.0, 50.0, 50.0]));
+    assert_eq!(crossing.len(), 4, "{crossing:?}");
+    // Nothing flipped through infinity: a corner behind the camera (y = −150, w = −50) would
+    // land at y = +300 if it were projected as is; clipped at the near plane it runs off far
+    // above (negative y) instead, and the front corners stay where they were.
+    assert!(crossing.iter().all(|p| p[0].is_finite() && p[1].is_finite() && p[1] < 34.0), "{crossing:?}");
+    assert!(project_clipped(&m, &box_corners([-50.0, -400.0, 50.0, -200.0])).is_empty(), "wholly behind");
+}
+
+#[test]
+fn axis_drag_follows_the_arrow_and_ignores_drag_across_it() {
+    let (ax, ay) = axis_drag([0.0, 0.0, 60.0], [24.0, -24.0]);
+    let at = |d: [f64; 2]| [0, 1, 2].map(|i| ax[i] * d[0] + ay[i] * d[1]);
+    assert_eq!(at([24.0, -24.0]), [0.0, 0.0, 60.0]);
+    assert_eq!(at([-12.0, 12.0]), [0.0, 0.0, -30.0]);
+    assert_eq!(at([10.0, 10.0]), [0.0, 0.0, 0.0]);
+}
+
+#[test]
+fn gizmo_segments_clip_at_the_near_plane() {
+    // w = 100 + z.
+    let pc = Mat4([[100.0, 0.0, 0.0, 0.0], [0.0, 100.0, 0.0, 0.0], [0.0, 0.0, 1.0, 0.0], [0.0, 0.0, 1.0, 100.0]]);
+    let s = project_segment(&pc, vec3(10.0, 0.0, 0.0), vec3(10.0, 0.0, -300.0)).unwrap();
+    assert_eq!(s[0], [10.0, 0.0]);
+    assert!(s[1][0] > 10.0 && s[1][0].is_finite(), "toward the camera it grows, never flips: {s:?}");
+    assert!(project_segment(&pc, vec3(0.0, 0.0, -200.0), vec3(0.0, 0.0, -300.0)).is_none());
+}
diff --git a/crates/ui-egui/src/panels/viewer/tools.rs b/crates/ui-egui/src/panels/viewer/tools.rs
new file mode 100644
index 000000000..8a3fbf0f3
--- /dev/null
+++ b/crates/ui-egui/src/panels/viewer/tools.rs
@@ -0,0 +1,298 @@
+use super::geometry::{cam_state, l2c, parent_inverse};
+use super::gesture::{Gesture, pen_id};
+use super::{CameraState, Color32, EffectcraftApp, EvalCtx, Layer, LayerId, Mat3, Pos2, Rect, Stroke, Tool, ViewerMap, gv2, json, ov, three_d, vec2, vt};
+
+/// The position change per comp pixel of drag (x, y) that moves a layer by `dir` when the
+/// pointer covers the axis' on-screen vector `s` (comp px); drag across the axis is ignored.
+pub(super) fn axis_drag(dir: [f64; 3], s: [f64; 2]) -> ([f64; 3], [f64; 3]) {
+    let n = (s[0] * s[0] + s[1] * s[1]).max(1e-12);
+    (dir.map(|v| v * s[0] / n), dir.map(|v| v * s[1] / n))
+}
+
+/// The gizmo arrow under screen point `p`.
+pub(super) fn axis_at(hits: &[(LayerId, [Pos2; 2], [f64; 3], [f64; 3])], p: Pos2) -> Option<(LayerId, [Pos2; 2], [f64; 3], [f64; 3])> {
+    let dist = |[a, b]: [Pos2; 2]| {
+        let ab = b - a;
+        let t = ((p - a).dot(ab) / ab.length_sq().max(1e-6)).clamp(0.0, 1.0);
+        p.distance(a + ab * t)
+    };
+    hits.iter().filter(|h| dist(h.1) < 6.0).min_by(|a, b| dist(a.1).total_cmp(&dist(b.1))).copied()
+}
+
+/// World to parent space for a 3D layer (identity without a parent).
+pub(super) fn parent_world_inverse(ctx: &EvalCtx, l: &Layer) -> effectcraft_engine::geom::Mat4 {
+    match l.parent.and_then(|p| ctx.comp.layer(p)) {
+        Some(p) => ctx.world_matrix(p).inverse().unwrap_or_default(),
+        None => effectcraft_engine::geom::Mat4::IDENTITY,
+    }
+}
+
+/// Parent-space position change per comp pixel of drag (x and y) for a layer: 2D layers map
+/// through the parent transform; 3D layers move in the view plane at their depth.
+pub(super) fn drag_axes(ctx: &EvalCtx, l: &Layer) -> ([f64; 3], [f64; 3]) {
+    if !l.is_3d() {
+        let inv = parent_inverse(ctx, l);
+        let a = inv.apply_vec(gv2(1.0, 0.0));
+        let b = inv.apply_vec(gv2(0.0, 1.0));
+        return ([a.x, a.y, 0.0], [b.x, b.y, 0.0]);
+    }
+    let cam = cam_state(ctx);
+    let anchor = l.transform().map(|tr| ctx.v3(l, tr, "anchor", [0.0; 3])).unwrap_or([0.0; 3]);
+    let wp = ctx.world_matrix(l).apply(anchor.into());
+    let k = if cam.ortho { 1.0 / cam.zoom.max(1e-9) } else { cam.depth(wp).max(1.0) / cam.zoom.max(1e-9) };
+    let pinv = parent_world_inverse(ctx, l);
+    let a = pinv.apply_vec(cam.right() * k);
+    let b = pinv.apply_vec(cam.down() * k);
+    ([a.x, a.y, a.z], [b.x, b.y, b.z])
+}
+
+/// Wireframes of cameras (frustum, point of interest) and lights (position, direction) as seen
+/// through the current 3D view.
+/// Camera and light wireframes seen through `cam` (`through_active`: `cam` is the active camera,
+/// which is then not drawn). `pane` names the automation ids: `None` for the main view
+/// (`viewer.camera.<id>`), `Some(view)` for a view of a 2- or 4-view layout
+/// (`viewer.view.<view>.camera.<id>`).
+#[allow(clippy::too_many_arguments)]
+pub(super) fn draw_rigs(
+    app: &mut EffectcraftApp,
+    painter: &egui::Painter,
+    map: &ViewerMap,
+    ectx: &EvalCtx,
+    selected: &[LayerId],
+    cam: CameraState,
+    through_active: bool,
+    pane: Option<&str>,
+) {
+    use effectcraft_engine::geom::Vec3;
+    use effectcraft_engine::project::{LayerSource, LightKind};
+    let (w, h) = (ectx.comp.width as f64, ectx.comp.height as f64);
+    let active = ectx.comp.active_camera(ectx.time).map(|c| c.id);
+    let prefix = pane.map(|v| format!("viewer.view.{v}.")).unwrap_or_else(|| "viewer.".to_string());
+    let proj = |p: Vec3| cam.project(w, h, p).map(|v| map.to_screen([v.x, v.y]));
+    let seg = |a: Vec3, b: Vec3, stroke: Stroke| {
+        if let (Some(x), Some(y)) = (proj(a), proj(b)) {
+            painter.line_segment([x, y], stroke);
+        }
+    };
+    for l in ectx.comp.layers.iter().filter(|l| (l.is_camera() || l.is_light()) && l.is_active_at(ectx.time)) {
+        let sel = selected.contains(&l.id);
+        let col = app.tokens.label(l.label).gamma_multiply(if sel { 1.0 } else { 0.6 });
+        let stroke = Stroke::new(if sel { 1.5 } else { 1.0 }, col);
+        let (eye, fwd, down) = three_d::camera::layer_frame(ectx, l);
+        let poi = |l: &Layer| -> Option<Vec3> {
+            let pr = l.transform()?.get("poi").filter(|_| three_d::camera::is_two_node(l))?;
+            Some(three_d::camera::parent_world(ectx, l).apply(ectx.value(l, pr).as_vec3().into()))
+        };
+        if l.is_camera() {
+            if through_active && Some(l.id) == active {
+                continue;
+            }
+            let zoom = l.props.prop("cameraOptions/zoom").map(|p| ectx.value(l, p).as_f64()).unwrap_or(1000.0);
+            let right = down.cross(fwd);
+            // Frustum to a plane at a quarter of the zoom distance.
+            let k = 0.25;
+            let c = eye + fwd * (zoom * k);
+            let corners = [(-1.0, -1.0), (1.0, -1.0), (1.0, 1.0), (-1.0, 1.0)].map(|(sx, sy)| c + right * (sx * w * 0.5 * k) + down * (sy * h * 0.5 * k));
+            for i in 0..4 {
+                seg(eye, corners[i], stroke);
+                seg(corners[i], corners[(i + 1) % 4], stroke);
+            }
+            if let Some(poi) = poi(l) {
+                seg(eye, poi, Stroke::new(1.0, col.gamma_multiply(0.6)));
+                if let Some(s) = proj(poi) {
+                    painter.circle_stroke(s, 4.0, stroke);
+                }
+            }
+            if let Some(s) = proj(eye) {
+                app.auto.add(&format!("{prefix}camera.{}", l.id.0), Rect::from_center_size(s, vec2(14.0, 14.0)), &l.name);
+            }
+        } else {
+            let LayerSource::Light { kind } = l.source else { continue };
+            if kind == LightKind::Ambient {
+                continue;
+            }
+            let Some(s) = proj(eye) else { continue };
+            painter.circle_stroke(s, 6.0, stroke);
+            for i in 0..8 {
+                let a = i as f32 * std::f32::consts::FRAC_PI_4;
+                let d = vec2(a.cos(), a.sin());
+                painter.line_segment([s + d * 8.0, s + d * 12.0], stroke);
+            }
+            if matches!(kind, LightKind::Spot | LightKind::Parallel) {
+                let target = poi(l).unwrap_or(eye + fwd * 300.0);
+                seg(eye, target, Stroke::new(1.0, col.gamma_multiply(0.7)));
+                if let Some(q) = proj(target) {
+                    painter.circle_stroke(q, 3.0, stroke);
+                }
+            }
+            app.auto.add(&format!("{prefix}light.{}", l.id.0), Rect::from_center_size(s, vec2(16.0, 16.0)), &l.name);
+        }
+    }
+}
+
+/// Pen tool press at `pos`: continue the path in progress (pressing its first vertex closes it),
+/// resume an open path whose last vertex is pressed, add a vertex on a visible path's segment, or
+/// start a new path: a mask on the selected footage/solid layer (or shape layer, with Tool Creates
+/// Mask), a shape path (Shape n group with the Tools bar's Fill and Stroke) on the selected shape
+/// layer, or a new shape layer when nothing is selected. The placed point snaps.
+/// Add a Position keyframe at a motion path's frame, keeping the path where it is.
+pub(super) fn add_motion_key(app: &mut EffectcraftApp, f: ov::PathFrame) {
+    if let Err(e) = app.session.execute("prop.addKey", json!({"layer": f.layer.0, "prop": f.prop, "time": f.time.seconds()})) {
+        app.ui.status = e.to_string();
+    }
+}
+
+/// Select only the motion path's keyframe `k` (what the vertex tools act on).
+pub(super) fn select_motion_key(app: &mut EffectcraftApp, k: &ov::KeyHit) -> bool {
+    app.session.execute("keys.select", json!({"keys": [{"layer": k.layer.0, "prop": k.prop, "time": k.time.seconds()}]})).is_ok()
+}
+
+/// The pointer for a Pen slot tool: the tool's own pen, the Pen showing Add Vertex's over a path
+/// it would add a point to (After Effects).
+pub(super) fn pen_cursor_icon(tool: Tool, over_path: bool) -> crate::icons::Icon {
+    use crate::icons::Icon;
+    match tool {
+        Tool::Pen if over_path => Icon::PenAdd,
+        Tool::PenAdd => Icon::PenAdd,
+        Tool::PenDelete => Icon::PenDelete,
+        Tool::PenConvert => Icon::PenConvert,
+        Tool::MaskFeather => Icon::MaskFeather,
+        _ => Icon::Pen,
+    }
+}
+
+/// Paint pen pointer `icon` with its tip at `at`, outlined for any background.
+pub(super) fn pen_cursor(ctx: &egui::Context, at: Pos2, icon: crate::icons::Icon) {
+    use crate::icons::Icon;
+    // Where each glyph's tip sits in its 16 × 16 box.
+    let tip = match icon {
+        Icon::PenAdd | Icon::PenDelete | Icon::MaskFeather => vec2(6.0, 2.5),
+        Icon::PenConvert => vec2(8.0, 3.5),
+        _ => vec2(8.0, 1.8),
+    };
+    let painter = ctx.layer_painter(egui::LayerId::new(egui::Order::Tooltip, egui::Id::unique("viewer-pen-cursor")));
+    let rect = Rect::from_min_size(at - tip, vec2(16.0, 16.0));
+    for d in [vec2(-1.0, 0.0), vec2(1.0, 0.0), vec2(0.0, -1.0), vec2(0.0, 1.0)] {
+        crate::icons::paint(&painter, rect.translate(d), icon, Color32::BLACK);
+    }
+    crate::icons::paint(&painter, rect, icon, Color32::WHITE);
+}
+
+/// Handle a Pen-tool press at `pos`: close the current path when its first vertex is hit; otherwise append a snapped
+/// (Shift: 45-degree) vertex, resume an open path's end, add a motion-path keyframe, insert a vertex on a visible
+/// path segment, or start a new mask/shape path on the selected layer or a new shape layer. Records the resulting
+/// path id and tangent gesture in context data for the drag that follows.
+#[allow(clippy::too_many_arguments)]
+pub(super) fn pen_press(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    ectx: &EvalCtx,
+    map: &ViewerMap,
+    paths: &[ov::PathInfo],
+    motion_frame: Option<ov::PathFrame>,
+    pos: Pos2,
+    mods: egui::Modifiers,
+) {
+    use effectcraft_engine::project::LayerSource;
+    let gid = egui::Id::unique("viewer-gesture");
+    let current: Option<(LayerId, u64)> = ui.data(|d| d.get_temp(pen_id()));
+    let c0 = map.to_comp(pos);
+    let corr = vt::snap(app, ui.ctx(), ectx, map, &[], &[c0], mods);
+    let c = [c0[0] + corr[0], c0[1] + corr[1]];
+    if let Some((lid, uid)) = current
+        && let Some(p) = ov::path_of(ectx, lid, uid)
+        && let Some(inv) = p.m.inverse()
+    {
+        let n = p.sp.vertices.len();
+        let first = p.sp.vertices.first().map(|v| {
+            let q = p.m.apply(gv2(v[0], v[1]));
+            map.to_screen([q.x, q.y])
+        });
+        if n >= 2 && first.is_some_and(|f| f.distance(pos) < 8.0) {
+            let _ = app.session.execute("mask.setClosed", json!({"layer": lid.0, "mask": uid, "closed": true}));
+            ui.data_mut(|d| {
+                d.remove::<(LayerId, u64)>(pen_id());
+                d.remove::<Gesture>(gid);
+            });
+            return;
+        }
+        // Shift keeps the new segment at a multiple of 45° from the vertex before it (#1544).
+        let last = p.sp.vertices.last().map(|v| p.m.apply(gv2(v[0], v[1])));
+        let c = match last {
+            Some(q) if mods.shift => constrain_45([q.x, q.y], c),
+            _ => c,
+        };
+        let lp = inv.apply(gv2(c[0], c[1]));
+        let lp = [lp.x, lp.y];
+        if let Ok(v) = app.session.execute("mask.addVertex", json!({"layer": lid.0, "mask": uid, "point": lp})) {
+            let index = v.as_u64().unwrap_or(0) as usize;
+            ui.data_mut(|d| d.insert_temp(gid, Gesture::Pen { layer: lid, mask: uid, index, vertex: lp, inv, press: pos }));
+        }
+        return;
+    }
+    // Clicking the last vertex of an open path (e.g. after Esc ended it) resumes drawing it.
+    if let Some(cur) = ov::open_end_at(paths, map, pos, 8.0) {
+        ui.data_mut(|d| d.insert_temp(pen_id(), cur));
+        return;
+    }
+    // On a visible path's segment the Pen adds a vertex there; on a motion path, a keyframe.
+    if let Some(f) = motion_frame {
+        add_motion_key(app, f);
+        return;
+    }
+    if let Some((l, m, seg, t)) = ov::segment_at(paths, map, pos, 5.0) {
+        let _ = app.session.execute("mask.insertVertex", json!({"layer": l.0, "mask": m, "segment": seg, "t": t}));
+        return;
+    }
+    let target = app
+        .session
+        .state
+        .selected_layers
+        .iter()
+        .copied()
+        .find(|id| ectx.comp.layer(*id).is_some_and(|l| !l.switches.locked && (l.masks().is_some() || matches!(l.source, LayerSource::Shape))));
+    let layer = target.and_then(|id| ectx.comp.layer(id));
+    let (lid, uid, inv) = match layer {
+        Some(l) if !matches!(l.source, LayerSource::Shape) || app.session.state.shape_tool.creates_mask => {
+            let Some(inv) = l2c(ectx, l).0.inverse() else { return };
+            let lp = inv.apply(gv2(c[0], c[1]));
+            let Ok(v) = app.session.execute("mask.new", json!({"layer": l.id.0, "vertices": [[lp.x, lp.y]]})) else { return };
+            let Some(mask) = v["mask"].as_u64() else { return };
+            (l.id, mask, inv)
+        }
+        Some(l) => {
+            let Some(inv) = l2c(ectx, l).0.inverse() else { return };
+            let lp = inv.apply(gv2(c[0], c[1]));
+            let r = app.session.execute("shape.newPath", json!({"layer": l.id.0, "vertices": [[lp.x, lp.y]], "space": "layer"}));
+            let Some(path) = r.ok().and_then(|v| v["path"].as_u64()) else { return };
+            (l.id, path, inv)
+        }
+        None => {
+            // A new shape layer at the comp centre (unrotated: comp → layer is a translation).
+            let r = app.session.execute("shape.newPath", json!({"vertices": [c], "space": "comp"}));
+            let Some(v) = r.ok() else { return };
+            let (Some(l), Some(path)) = (v["layer"].as_u64(), v["path"].as_u64()) else { return };
+            let inv = Mat3::translate(gv2(-(ectx.comp.width as f64) / 2.0, -(ectx.comp.height as f64) / 2.0));
+            (LayerId(l), path, inv)
+        }
+    };
+    let lp = inv.apply(gv2(c[0], c[1]));
+    ui.data_mut(|d| {
+        d.insert_temp(pen_id(), (lid, uid));
+        d.insert_temp(gid, Gesture::Pen { layer: lid, mask: uid, index: 0, vertex: [lp.x, lp.y], inv, press: pos });
+    });
+}
+
+/// `to` moved onto the nearest line through `from` at a multiple of 45° (horizontal, vertical or
+/// diagonal), as far along it as `to` lies: the Pen's Shift-click.
+pub(super) fn constrain_45(from: [f64; 2], to: [f64; 2]) -> [f64; 2] {
+    let (dx, dy) = (to[0] - from[0], to[1] - from[1]);
+    if !(dx.is_finite() && dy.is_finite()) || (dx == 0.0 && dy == 0.0) {
+        return to;
+    }
+    let step = std::f64::consts::FRAC_PI_4;
+    let a = (dy.atan2(dx) / step).round() * step;
+    let (ux, uy) = (a.cos(), a.sin());
+    let along = dx * ux + dy * uy;
+    [from[0] + ux * along, from[1] + uy * along]
+}
diff --git a/crates/ui-egui/src/panels/viewer/view.rs b/crates/ui-egui/src/panels/viewer/view.rs
new file mode 100644
index 000000000..30b3f4d00
--- /dev/null
+++ b/crates/ui-egui/src/panels/viewer/view.rs
@@ -0,0 +1,222 @@
+use super::tools::draw_rigs;
+use super::{Align2, Color32, EffectcraftApp, EvalCtx, Rect, Sense, Stroke, StrokeKind, Tokens, View3D, ViewerMap, json, pos2, three_d, vec2, widgets};
+
+/// Draw the extra views of a 2- or 4-view layout and return the main view's rectangle.
+pub(super) fn aux_views(
+    app: &mut EffectcraftApp,
+    ui: &mut egui::Ui,
+    comp: &effectcraft_engine::project::Comp,
+    cid: effectcraft_engine::project::ItemId,
+    full: Rect,
+    bg: Color32,
+) -> Rect {
+    let n = app.session.state.view_layout;
+    if n < 2 {
+        return full;
+    }
+    let gap = 2.0;
+    let views = app.session.state.views3d.get(&cid).cloned().unwrap_or_default();
+    let (main, aux): (Rect, Vec<(Rect, View3D)>) = if n == 2 {
+        let mid = full.center().x;
+        (
+            Rect::from_min_max(pos2(mid + gap / 2.0, full.min.y), full.max),
+            vec![(Rect::from_min_max(full.min, pos2(mid - gap / 2.0, full.max.y)), views.pane(0))],
+        )
+    } else {
+        let c = full.center();
+        let q = |x0: f32, y0: f32, x1: f32, y1: f32| Rect::from_min_max(pos2(x0, y0), pos2(x1, y1));
+        (
+            q(c.x + gap / 2.0, c.y + gap / 2.0, full.max.x, full.max.y),
+            vec![
+                (q(full.min.x, full.min.y, c.x - gap / 2.0, c.y - gap / 2.0), views.pane(0)),
+                (q(c.x + gap / 2.0, full.min.y, full.max.x, c.y - gap / 2.0), views.pane(1)),
+                (q(full.min.x, c.y + gap / 2.0, c.x - gap / 2.0, full.max.y), views.pane(2)),
+            ],
+        )
+    };
+    let ctx = ui.ctx().clone();
+    let p = ui.painter().clone();
+    p.rect_filled(full, 0.0, Color32::from_black_alpha(200));
+    let t = app.session.time();
+    let (cw, ch) = (comp.width as f32, comp.height as f32);
+    let share = app.session.state.share_view_options;
+    // The camera and light wireframes of each view (as in After Effects, where every view of the
+    // layout shows them), evaluated on a snapshot of the project.
+    let snap_project = app.session.project.clone();
+    let snap_expr = app.session.expr.clone();
+    let ectx = EvalCtx { project: &snap_project, comp_id: cid, comp, time: t, expr: snap_expr.as_deref(), footage: None };
+    let selected = app.session.state.selected_layers.clone();
+    let mut picked: Option<(usize, View3D)> = None;
+    for (i, (r, v)) in aux.into_iter().enumerate() {
+        p.rect_filled(r, 0.0, bg);
+        let fit = ((r.width() - 20.0) / cw).min((r.height() - 20.0) / ch).max(0.01);
+        let cr = Rect::from_center_size(r.center(), vec2(cw * fit, ch * fit));
+        let scale = (fit * ctx.pixels_per_point()).min(1.0) as f64;
+        // The Active Camera pane renders through the comp's own camera; the others through their
+        // view camera.
+        let through_active = v == View3D::ActiveCamera;
+        let cam = if through_active { three_d::active_camera(&ectx) } else { views.cam(v, comp.width as f64, comp.height as f64).state() };
+        let key = {
+            use std::hash::{Hash, Hasher};
+            let mut h = std::collections::hash_map::DefaultHasher::new();
+            (app.session.revision, cid.0, t.0, i, scale.to_bits(), format!("{cam:?}")).hash(&mut h);
+            h.finish()
+        };
+        let id = egui::Id::unique(("viewer-aux", i));
+        let cached: Option<(u64, egui::TextureHandle)> = ctx.data(|d| d.get_temp(id));
+        let tex = match cached {
+            Some((k, tex)) if k == key => tex,
+            _ => {
+                let opts = effectcraft_engine::render::RenderOpts {
+                    scale,
+                    view: (comp.has_3d() && !through_active).then_some(cam),
+                    draft: true,
+                    ..Default::default()
+                };
+                let img = app.session.render(cid, t, opts);
+                let tex = crate::frames::load_fitted(&ctx, format!("viewer-aux-{i}"), crate::frames::to_color_image(&img), egui::TextureOptions::LINEAR);
+                ctx.data_mut(|d| d.insert_temp(id, (key, tex.clone())));
+                tex
+            }
+        };
+        let b = comp.background;
+        p.rect_filled(cr, 0.0, Color32::from_rgb((b[0] * 255.0) as u8, (b[1] * 255.0) as u8, (b[2] * 255.0) as u8));
+        p.image(tex.id(), cr, Rect::from_min_max(pos2(0.0, 0.0), pos2(1.0, 1.0)), Color32::WHITE);
+        p.rect_stroke(cr, 0.0, Stroke::new(1.0, Color32::from_black_alpha(160)), StrokeKind::Outside);
+        if share && app.ui.viewer.safe_margins {
+            for k in [0.9, 0.8] {
+                p.rect_stroke(Rect::from_center_size(cr.center(), cr.size() * k), 0.0, Stroke::new(1.0, Color32::from_white_alpha(120)), StrokeKind::Middle);
+            }
+        }
+        if comp.has_3d() {
+            let map = ViewerMap { origin: cr.min, zoom: fit, comp: [cw, ch], area: r };
+            draw_rigs(app, &p.with_clip_rect(r), &map, &ectx, &selected, cam, through_active, Some(v.id()));
+        }
+        let label = if comp.has_3d() { v.label() } else { crate::i18n::tr("Active Camera") };
+        p.text(r.left_bottom() + vec2(8.0, -8.0), Align2::LEFT_BOTTOM, label, Tokens::ui(11.0), Color32::from_white_alpha(200));
+        app.auto.add(&format!("viewer.view.{}", v.id()), r, label);
+        if comp.has_3d()
+            && let Some(chosen) = pane_selector(app, ui, i + 1, r, v)
+        {
+            picked = Some((i + 1, chosen));
+        }
+    }
+    if let Some((pane, v)) = picked
+        && let Err(e) = app.session.execute("view.setPaneView", json!({"pane": pane, "view": v.id(), "comp": cid.0}))
+    {
+        app.ui.status = e.to_string();
+    }
+    main
+}
+
+/// The view selector in the top-left corner of pane `pane` (1 to 3) of a multi-view layout, a
+/// popup of every 3D view like the toolbar's 3D View menu. Returns the view chosen this frame.
+fn pane_selector(app: &mut EffectcraftApp, ui: &mut egui::Ui, pane: usize, area: Rect, current: View3D) -> Option<View3D> {
+    let t = app.tokens;
+    let r = Rect::from_min_size(area.min + vec2(6.0, 6.0), vec2(124.0, 20.0));
+    let pid = egui::Id::unique(("viewer-pane-view", pane));
+    let response = widgets::dropdown(ui, r, crate::i18n::tr(current.label()), &t, pid);
+    if response.clicked() {
+        let open = widgets::popup_is_open(ui, pid);
+        ui.data_mut(|d| d.insert_temp(pid.with("open"), !open));
+    }
+    app.auto.add_response(&format!("viewer.view.{pane}.type"), &response, "View of pane");
+    if !widgets::popup_is_open(ui, pid) {
+        return None;
+    }
+    let chosen = widgets::popup_list(ui, pid, r.left_bottom() + vec2(0.0, 2.0), r, View3D::ALL.len(), 0, |ui| {
+        ui.set_min_width(124.0);
+        let mut chosen = None;
+        for (k, v) in View3D::ALL.iter().enumerate() {
+            let item = ui.selectable_label(*v == current, crate::i18n::tr(v.label()));
+            app.auto.add(&format!("viewer.view.{pane}.typeItem.{k}"), item.rect, v.label());
+            if item.clicked() {
+                chosen = Some(*v);
+            }
+        }
+        chosen
+    });
+    chosen.filter(|v| *v != current)
+}
+
+/// View ▸ Split with New Locked Viewer: the locked viewer on the left of the Composition panel
+/// (its comp and 3D view stay put whatever comp is active). Returns the main viewer's rectangle.
+pub(super) fn locked_pane(app: &mut EffectcraftApp, ui: &mut egui::Ui, full: Rect, bg: Color32) -> Rect {
+    let Some(lv) = app.session.state.locked_viewer else { return full };
+    let Some(comp) = app.session.project.comp_arc(lv.comp) else { return full };
+    let name = app.session.project.item(lv.comp).map(|i| i.name.clone()).unwrap_or_default();
+    let gap = 2.0;
+    let mid = full.center().x;
+    let r = Rect::from_min_max(full.min, pos2(mid - gap / 2.0, full.max.y));
+    let main = Rect::from_min_max(pos2(mid + gap / 2.0, full.min.y), full.max);
+    let ctx = ui.ctx().clone();
+    let p = ui.painter().clone();
+    p.rect_filled(Rect::from_min_max(pos2(r.max.x, full.min.y), pos2(main.min.x, full.max.y)), 0.0, Color32::from_black_alpha(200));
+    p.rect_filled(r, 0.0, bg);
+    let (cw, ch) = (comp.width as f32, comp.height as f32);
+    let fit = ((r.width() - 20.0) / cw).min((r.height() - 44.0) / ch).max(0.01);
+    let cr = Rect::from_center_size(r.center(), vec2(cw * fit, ch * fit));
+    let scale = (fit * ctx.pixels_per_point()).min(1.0) as f64;
+    let t = app.session.time_of(lv.comp);
+    let cam = (lv.view != View3D::ActiveCamera && comp.has_3d())
+        .then(|| app.session.state.views3d.get(&lv.comp).cloned().unwrap_or_default().cam(lv.view, comp.width as f64, comp.height as f64).state());
+    let dc = effectcraft_engine::viewer::DisplayColor::of(&app.session);
+    // The display conversion's inputs, keyed as in the main viewer's texture caches.
+    let dc_key = format!("{cam:?}{}", crate::panels::viewer_tools::display_key(app, dc.is_some()));
+    let key = {
+        use std::hash::{Hash, Hasher};
+        let mut h = std::collections::hash_map::DefaultHasher::new();
+        (app.session.revision, lv.comp.0, t.0, scale.to_bits(), dc_key).hash(&mut h);
+        h.finish()
+    };
+    let id = egui::Id::unique("viewer-locked");
+    let cached: Option<(u64, egui::TextureHandle)> = ctx.data(|d| d.get_temp(id));
+    let tex = match cached {
+        Some((k, tex)) if k == key => tex,
+        _ => {
+            let opts = effectcraft_engine::render::RenderOpts { scale, view: cam, ..Default::default() };
+            let img = app.session.render(lv.comp, t, opts);
+            let mut ci = crate::frames::to_color_image(&img);
+            if let Some(dc) = dc {
+                let mut px: Vec<[u8; 4]> = ci.pixels.iter().map(|c| c.to_array()).collect();
+                dc.apply(&mut px);
+                ci = egui::ColorImage::new(ci.size, px.into_iter().map(|a| Color32::from_rgba_premultiplied(a[0], a[1], a[2], a[3])).collect());
+            }
+            let tex = crate::frames::load_fitted(&ctx, "viewer-locked", ci, egui::TextureOptions::LINEAR);
+            ctx.data_mut(|d| d.insert_temp(id, (key, tex.clone())));
+            tex
+        }
+    };
+    let b = comp.background;
+    p.rect_filled(cr, 0.0, Color32::from_rgb((b[0] * 255.0) as u8, (b[1] * 255.0) as u8, (b[2] * 255.0) as u8));
+    p.image(tex.id(), cr, Rect::from_min_max(pos2(0.0, 0.0), pos2(1.0, 1.0)), Color32::WHITE);
+    p.rect_stroke(cr, 0.0, Stroke::new(1.0, Color32::from_black_alpha(160)), StrokeKind::Outside);
+    let label = crate::i18n::tr_args("Locked: {} — {}", &[&name, &(if comp.has_3d() { lv.view.label() } else { crate::i18n::tr("Active Camera") })]);
+    p.text(r.left_top() + vec2(8.0, 8.0), Align2::LEFT_TOP, &label, Tokens::ui(11.0), Color32::from_white_alpha(210));
+    app.auto.add("viewer.locked", r, &label);
+    // Close the locked viewer.
+    let close = Rect::from_min_size(pos2(r.max.x - 26.0, r.min.y + 4.0), vec2(20.0, 20.0));
+    let resp = ui.interact(close, egui::Id::unique("viewer-locked-close"), Sense::click());
+    p.text(close.center(), Align2::CENTER_CENTER, "\u{00d7}", Tokens::ui(14.0), if resp.hovered() { Color32::WHITE } else { Color32::from_white_alpha(170) });
+    app.auto.add("viewer.locked.close", close, "Close Locked Viewer");
+    if resp.clicked() {
+        let _ = app.session.execute("view.closeLockedViewer", serde_json::json!({}));
+    }
+    main
+}
+
+pub(crate) fn checker(p: &egui::Painter, r: Rect) {
+    let s = 10.0;
+    p.rect_filled(r, 0.0, Color32::from_gray(0xcc));
+    let mut y = r.min.y;
+    let mut row = 0;
+    while y < r.max.y {
+        let mut x = r.min.x + if row % 2 == 0 { 0.0 } else { s };
+        while x < r.max.x {
+            p.rect_filled(Rect::from_min_max(pos2(x, y), pos2((x + s).min(r.max.x), (y + s).min(r.max.y))), 0.0, Color32::from_gray(0x99));
+            x += 2.0 * s;
+        }
+        y += s;
+        row += 1;
+    }
+}
diff --git a/crates/ui-egui/src/panels/viewer_text.rs b/crates/ui-egui/src/panels/viewer_text.rs
index 5fe55638e..ce387f6ca 100644
--- a/crates/ui-egui/src/panels/viewer_text.rs
+++ b/crates/ui-egui/src/panels/viewer_text.rs
@@ -810,6 +810,91 @@ fn typing_key(ui: &egui::Ui, bump: bool) -> String {
     format!("text-typing-{n}")
 }
 
+/// A press inside the edited text layer: grab a box handle, place the caret (shift extends from
+/// `shift_anchor`), or, outside the text, commit the edit. Returns the drag it starts, if any.
+fn press_on_edited(app: &mut EffectcraftApp, ui: &egui::Ui, map: &ViewerMap, e: &Edited, pos: Pos2, shift_anchor: Option<usize>) -> Option<Drag> {
+    if let Some(h) = e.handles().iter().position(|h| e.to_screen(map, *h).distance(pos) < 7.0) {
+        let b = e.doc.box_size.unwrap_or([0.0; 2]);
+        return Some(Drag::Resize { layer: e.layer.id, handle: h, start_box: [e.doc.box_pos[0], e.doc.box_pos[1], b[0], b[1]] });
+    }
+    if e.contains(map, pos) {
+        let ci = e.hit(map, pos);
+        exec(app, "text.setSelection", json!({"anchor": shift_anchor.unwrap_or(ci), "caret": ci}));
+        typing_key(ui, true);
+        return Some(Drag::Select { layer: e.layer.id });
+    }
+    // Clicking elsewhere commits the edit.
+    exec(app, "text.endEdit", json!({}));
+    None
+}
+
+/// A press with the Type tool that missed the edited text: edit the text layer under it, or
+/// start creating a new one.
+fn press_type_tool(app: &mut EffectcraftApp, ectx: &EvalCtx, map: &ViewerMap, pos: Pos2, tool: Tool) -> Drag {
+    if let Some(e) = text_layer_at(app, ectx, map, pos, true) {
+        let ci = e.hit(map, pos);
+        exec(app, "text.edit", json!({"layer": e.layer.id.0, "caret": ci}));
+        Drag::Select { layer: e.layer.id }
+    } else {
+        Drag::Create { start: map.to_comp(pos), vertical: tool == Tool::TypeVertical }
+    }
+}
+
+/// The paragraph box after dragging `handle` by (`dx`, `dy`) in layer space.
+fn resized_box(start_box: [f64; 4], handle: usize, dx: f64, dy: f64) -> [f64; 4] {
+    let [mut x0, mut y0, w, h] = start_box;
+    let (mut x1, mut y1) = (x0 + w, y0 + h);
+    if matches!(handle, 0 | 6 | 7) {
+        x0 += dx;
+    }
+    if matches!(handle, 2..=4) {
+        x1 += dx;
+    }
+    if matches!(handle, 0..=2) {
+        y0 += dy;
+    }
+    if matches!(handle, 4..=6) {
+        y1 += dy;
+    }
+    [x0.min(x1), y0.min(y1), (x1 - x0).abs().max(4.0), (y1 - y0).abs().max(4.0)]
+}
+
+/// Keyboard routing for the text editor: while a session is live, keep the focus on it and feed
+/// it this frame's keys; otherwise release the IME and the focus.
+fn keyboard_focus(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
+    if app.session.state.text_edit.is_some() && app.dialog.is_none() && ui.is_enabled() {
+        // Register after pointer handling so new edits take focus in this frame. An inactive
+        // editor must not take Tab focus and immediately surrender it before viewer controls.
+        ui.interact(Rect::from_min_size(rect.min, vec2(1.0, 1.0)), focus_id(), egui::Sense::focusable_noninteractive());
+        ui.memory_mut(|m| {
+            m.set_focus_lock_filter(focus_id(), egui::EventFilter { tab: true, horizontal_arrows: true, vertical_arrows: true, escape: true });
+        });
+        // A session started elsewhere (menu, agent, Properties) takes the keyboard once…
+        let seen = ime_seen_id(ui.ctx().viewport_id());
+        let key = app.session.state.text_edit.as_ref().map(|e| (e.layer.0, e.session));
+        // …and gets it back when a click in the viewer or a formatting panel left nothing holding
+        // it; not merely because nothing has the focus (#831).
+        let regain = ui.memory(|m| m.focused().is_none()) && keeps_text_edit(app.ui.focused);
+        if ui.data(|d| d.get_temp::<Option<(u64, u64)>>(seen)).flatten() != key || regain {
+            ui.data_mut(|d| d.insert_temp(seen, key));
+            ui.memory_mut(|m| m.request_focus(focus_id()));
+        }
+        if ui.memory(|m| m.has_focus(focus_id())) {
+            keyboard(app, ui, rect);
+        }
+    } else {
+        // Resolve the viewport before taking the data lock: `viewport_id()`
+        // acquires the same context lock that `data_mut` holds.
+        let viewport = ui.ctx().viewport_id();
+        ui.data_mut(|d| d.insert_temp::<Option<(u64, u64)>>(ime_seen_id(viewport), None));
+        invalidate_ime_composition(ui, app);
+        clear_preedit(ui);
+        if ui.memory(|m| m.has_focus(focus_id())) {
+            ui.memory_mut(|m| m.surrender_focus(focus_id()));
+        }
+    }
+}
+
 /// Viewer hook: draws the edit overlay and handles text pointer and keyboard input. Returns
 /// true when it owns this frame's pointer interaction (the viewer then skips its own gestures).
 pub fn hook(
@@ -858,7 +943,6 @@ pub fn hook(
         }
     });
     let pointer = ui.input(|i| i.pointer.interact_pos());
-    let handle_hit = |e: &Edited, s: Pos2| e.handles().iter().position(|h| e.to_screen(map, *h).distance(s) < 7.0);
 
     // ---- press
     if pressed
@@ -870,30 +954,14 @@ pub fn hook(
     {
         let mut handled = false;
         if let Some(e) = &cur {
-            if let Some(h) = handle_hit(e, pos) {
-                let b = e.doc.box_size.unwrap_or([0.0; 2]);
-                drag = Some(Drag::Resize { layer: e.layer.id, handle: h, start_box: [e.doc.box_pos[0], e.doc.box_pos[1], b[0], b[1]] });
+            let shift_anchor = if mods.shift { Some(editing.as_ref().map_or_else(|| e.hit(map, pos), |sel| sel.anchor)) } else { None };
+            if let Some(d) = press_on_edited(app, ui, map, e, pos, shift_anchor) {
+                drag = Some(d);
                 handled = true;
-            } else if e.contains(map, pos) {
-                let ci = e.hit(map, pos);
-                let anchor = if mods.shift { editing.as_ref().map_or(ci, |sel| sel.anchor) } else { ci };
-                exec(app, "text.setSelection", json!({"anchor": anchor, "caret": ci}));
-                typing_key(ui, true);
-                drag = Some(Drag::Select { layer: e.layer.id });
-                handled = true;
-            } else {
-                // Clicking elsewhere commits the edit.
-                exec(app, "text.endEdit", json!({}));
             }
         }
         if !handled && type_tool {
-            if let Some(e) = text_layer_at(app, ectx, map, pos, true) {
-                let ci = e.hit(map, pos);
-                exec(app, "text.edit", json!({"layer": e.layer.id.0, "caret": ci}));
-                drag = Some(Drag::Select { layer: e.layer.id });
-            } else {
-                drag = Some(Drag::Create { start: map.to_comp(pos), vertical: tool == Tool::TypeVertical });
-            }
+            drag = Some(press_type_tool(app, ectx, map, pos, tool));
             handled = true;
         }
         if handled {
@@ -948,22 +1016,7 @@ pub fn hook(
             {
                 let (px, py) = e.to_layer(map, p);
                 let (qx, qy) = e.to_layer(map, q);
-                let (dx, dy) = (px - qx, py - qy);
-                let [mut x0, mut y0, w, h] = start_box;
-                let (mut x1, mut y1) = (x0 + w, y0 + h);
-                if matches!(handle, 0 | 6 | 7) {
-                    x0 += dx;
-                }
-                if matches!(handle, 2..=4) {
-                    x1 += dx;
-                }
-                if matches!(handle, 0..=2) {
-                    y0 += dy;
-                }
-                if matches!(handle, 4..=6) {
-                    y1 += dy;
-                }
-                let bx = [x0.min(x1), y0.min(y1), (x1 - x0).abs().max(4.0), (y1 - y0).abs().max(4.0)];
+                let bx = resized_box(start_box, handle, px - qx, py - qy);
                 exec(app, "layer.setText", json!({"layer": layer.0, "box": bx, "merge": format!("text-box-{}", layer.0)}));
             }
         }
@@ -1009,37 +1062,7 @@ pub fn hook(
     // composition's identity as a stale guard before this pass's IME events are read.
     sync_ime_target(ui, app);
     sync_ime_selection(ui, app);
-    if app.session.state.text_edit.is_some() && app.dialog.is_none() && ui.is_enabled() {
-        // Register after pointer handling so new edits take focus in this frame. An inactive
-        // editor must not take Tab focus and immediately surrender it before viewer controls.
-        ui.interact(Rect::from_min_size(resp.rect.min, vec2(1.0, 1.0)), focus_id(), egui::Sense::focusable_noninteractive());
-        ui.memory_mut(|m| {
-            m.set_focus_lock_filter(focus_id(), egui::EventFilter { tab: true, horizontal_arrows: true, vertical_arrows: true, escape: true });
-        });
-        // A session started elsewhere (menu, agent, Properties) takes the keyboard once…
-        let seen = ime_seen_id(ui.ctx().viewport_id());
-        let key = app.session.state.text_edit.as_ref().map(|e| (e.layer.0, e.session));
-        // …and gets it back when a click in the viewer or a formatting panel left nothing holding
-        // it; not merely because nothing has the focus (#831).
-        let regain = ui.memory(|m| m.focused().is_none()) && keeps_text_edit(app.ui.focused);
-        if ui.data(|d| d.get_temp::<Option<(u64, u64)>>(seen)).flatten() != key || regain {
-            ui.data_mut(|d| d.insert_temp(seen, key));
-            ui.memory_mut(|m| m.request_focus(focus_id()));
-        }
-        if ui.memory(|m| m.has_focus(focus_id())) {
-            keyboard(app, ui, resp.rect);
-        }
-    } else {
-        // Resolve the viewport before taking the data lock: `viewport_id()`
-        // acquires the same context lock that `data_mut` holds.
-        let viewport = ui.ctx().viewport_id();
-        ui.data_mut(|d| d.insert_temp::<Option<(u64, u64)>>(ime_seen_id(viewport), None));
-        invalidate_ime_composition(ui, app);
-        clear_preedit(ui);
-        if ui.memory(|m| m.has_focus(focus_id())) {
-            ui.memory_mut(|m| m.surrender_focus(focus_id()));
-        }
-    }
+    keyboard_focus(app, ui, resp.rect);
 
     // ---- overlay
     if let Some(s) = app.session.state.text_edit.clone()
@@ -1219,111 +1242,7 @@ fn keyboard(app: &mut EffectcraftApp, ui: &mut egui::Ui, viewer: Rect) {
                 }
                 typing_key(ui, true);
             }
-            egui::Event::Key { key, pressed: true, modifiers: m, .. } => {
-                use egui::Key;
-                let cmd = m.command;
-                let mv = |app: &mut EffectcraftApp, to: &str| {
-                    exec(app, "text.moveCaret", json!({"to": to, "extend": m.shift}));
-                };
-                match key {
-                    Key::ArrowLeft | Key::ArrowRight if m.alt => {
-                        // Kerning at the caret, tracking over a selection.
-                        let step = if cmd { 100.0 } else { 20.0 } * if key == Key::ArrowLeft { -1.0 } else { 1.0 };
-                        let doc = layer_doc(&app.session, sel.layer).unwrap_or_default();
-                        if sel.is_empty() {
-                            if sel.caret < doc.char_len() {
-                                let cur = match doc.style_at(sel.caret).kerning {
-                                    Kerning::Manual(v) => v,
-                                    _ => 0.0,
-                                };
-                                exec(
-                                    app,
-                                    "layer.setText",
-                                    json!({"layer": sel.layer.0, "range": [sel.caret, sel.caret + 1], "kerning": cur + step, "merge": format!("text-kern-{}", sel.caret)}),
-                                );
-                            }
-                        } else {
-                            let r = sel.range();
-                            let cur = doc.style_at(r.start).tracking;
-                            exec(app, "layer.setText", json!({"layer": sel.layer.0, "range": [r.start, r.end], "tracking": cur + step, "merge": "text-track"}));
-                        }
-                    }
-                    Key::ArrowLeft => mv(app, if cmd { "wordLeft" } else { "left" }),
-                    Key::ArrowRight => mv(app, if cmd { "wordRight" } else { "right" }),
-                    Key::ArrowUp => mv(app, if cmd { "paraUp" } else { "up" }),
-                    Key::ArrowDown => mv(app, if cmd { "paraDown" } else { "down" }),
-                    Key::Home => mv(app, if cmd { "start" } else { "lineStart" }),
-                    Key::End => mv(app, if cmd { "end" } else { "lineEnd" }),
-                    Key::Backspace => {
-                        let k = typing_key(ui, false);
-                        let before = ime_stamp(app, &ctx);
-                        if exec(app, "text.delete", json!({"word": cmd || m.alt, "merge": k})).is_some() {
-                            note_ime_application_edit(app, &ctx, before);
-                        }
-                    }
-                    Key::Delete => {
-                        let k = typing_key(ui, false);
-                        let before = ime_stamp(app, &ctx);
-                        if exec(app, "text.delete", json!({"direction": "forward", "word": cmd || m.alt, "merge": k})).is_some() {
-                            note_ime_application_edit(app, &ctx, before);
-                        }
-                    }
-                    Key::Enter if cmd => {
-                        exec(app, "text.endEdit", json!({}));
-                    }
-                    Key::Enter => {
-                        let k = typing_key(ui, false);
-                        let before = ime_stamp(app, &ctx);
-                        if exec(app, "text.insert", json!({"text": "\n", "merge": k})).is_some() {
-                            note_ime_application_edit(app, &ctx, before);
-                        }
-                    }
-                    Key::Tab => {
-                        let k = typing_key(ui, false);
-                        let before = ime_stamp(app, &ctx);
-                        if exec(app, "text.insert", json!({"text": "\t", "merge": k})).is_some() {
-                            note_ime_application_edit(app, &ctx, before);
-                        }
-                    }
-                    Key::Escape => {
-                        exec(app, "text.endEdit", json!({}));
-                    }
-                    // The editor owns exactly Cmd/Ctrl+A (Select All) and Cmd/Ctrl+Z with or
-                    // without Shift (Undo, Redo). Other modifiers on those keys aren't editing
-                    // chords, so they fall through to the binding match below: Shift+A is
-                    // Deselect All's default, and Alt variants are free for a rebound one.
-                    Key::A if cmd && !m.shift && !m.alt => {
-                        exec(app, "text.setSelection", json!({"select": "all"}));
-                    }
-                    Key::Z if cmd && !m.alt => {
-                        let before = ime_stamp(app, &ctx);
-                        if crate::menus::invoke(app, &ctx, if m.shift { "edit.redo" } else { "edit.undo" }, json!({})).is_ok() {
-                            note_ime_application_edit(app, &ctx, before);
-                        }
-                    }
-                    Key::Comma | Key::Period if cmd && m.shift => {
-                        let doc = layer_doc(&app.session, sel.layer).unwrap_or_default();
-                        let r = sel.range();
-                        let size = sel.pending.as_ref().map_or_else(|| doc.style_at(r.start).size, |p| p.size);
-                        let ns = (size + if key == Key::Period { 2.0 } else { -2.0 }).max(1.0);
-                        exec(app, "layer.setText", json!({"layer": sel.layer.0, "range": [r.start, r.end], "size": ns}));
-                    }
-                    // The app-wide shortcut dispatcher is skipped while this editor holds the
-                    // keyboard, so the Deselect All chord (Cmd/Ctrl+Shift+A or F2 by default)
-                    // must be matched here and run through the command dispatcher like undo
-                    // above. Matching the command's current binding, not a fixed key, keeps
-                    // rebound shortcuts working and gives every route one final state; the
-                    // forwarding test also refuses chords a focused editor must never surrender
-                    // (see `forwardable_during_text_edit`).
-                    _ if crate::menus::chord_matches(&app.session, "edit.deselectAll", key, m) && crate::menus::forwardable_during_text_edit(m, key) => {
-                        let _ = crate::menus::invoke(app, &ctx, "edit.deselectAll", json!({}));
-                    }
-                    _ => {}
-                }
-                if !matches!(key, Key::Backspace | Key::Delete | Key::Enter | Key::Tab) {
-                    typing_key(ui, true);
-                }
-            }
+            egui::Event::Key { key, pressed: true, modifiers: m, .. } => key_event(app, ui, &ctx, &sel, key, m),
             _ => {}
         }
         let route_ended = app.session.state.text_edit.is_none() || app.dialog.is_some();
@@ -1344,6 +1263,121 @@ fn keyboard(app: &mut EffectcraftApp, ui: &mut egui::Ui, viewer: Rect) {
     }
 }
 
+/// An application key press in the edited text: caret moves, deletes, insertions, formatting and
+/// the editor's own chords.
+fn key_event(
+    app: &mut EffectcraftApp,
+    ui: &egui::Ui,
+    ctx: &egui::Context,
+    sel: &effectcraft_engine::commands::text_edit::TextEdit,
+    key: egui::Key,
+    m: egui::Modifiers,
+) {
+    use egui::Key;
+    let cmd = m.command;
+    let mv = |app: &mut EffectcraftApp, to: &str| {
+        exec(app, "text.moveCaret", json!({"to": to, "extend": m.shift}));
+    };
+    match key {
+        Key::ArrowLeft | Key::ArrowRight if m.alt => {
+            // Kerning at the caret, tracking over a selection.
+            let step = if cmd { 100.0 } else { 20.0 } * if key == Key::ArrowLeft { -1.0 } else { 1.0 };
+            let doc = layer_doc(&app.session, sel.layer).unwrap_or_default();
+            if sel.is_empty() {
+                if sel.caret < doc.char_len() {
+                    let cur = match doc.style_at(sel.caret).kerning {
+                        Kerning::Manual(v) => v,
+                        _ => 0.0,
+                    };
+                    exec(
+                        app,
+                        "layer.setText",
+                        json!({"layer": sel.layer.0, "range": [sel.caret, sel.caret + 1], "kerning": cur + step, "merge": format!("text-kern-{}", sel.caret)}),
+                    );
+                }
+            } else {
+                let r = sel.range();
+                let cur = doc.style_at(r.start).tracking;
+                exec(app, "layer.setText", json!({"layer": sel.layer.0, "range": [r.start, r.end], "tracking": cur + step, "merge": "text-track"}));
+            }
+        }
+        Key::ArrowLeft => mv(app, if cmd { "wordLeft" } else { "left" }),
+        Key::ArrowRight => mv(app, if cmd { "wordRight" } else { "right" }),
+        Key::ArrowUp => mv(app, if cmd { "paraUp" } else { "up" }),
+        Key::ArrowDown => mv(app, if cmd { "paraDown" } else { "down" }),
+        Key::Home => mv(app, if cmd { "start" } else { "lineStart" }),
+        Key::End => mv(app, if cmd { "end" } else { "lineEnd" }),
+        Key::Backspace => {
+            let k = typing_key(ui, false);
+            let before = ime_stamp(app, ctx);
+            if exec(app, "text.delete", json!({"word": cmd || m.alt, "merge": k})).is_some() {
+                note_ime_application_edit(app, ctx, before);
+            }
+        }
+        Key::Delete => {
+            let k = typing_key(ui, false);
+            let before = ime_stamp(app, ctx);
+            if exec(app, "text.delete", json!({"direction": "forward", "word": cmd || m.alt, "merge": k})).is_some() {
+                note_ime_application_edit(app, ctx, before);
+            }
+        }
+        Key::Enter if cmd => {
+            exec(app, "text.endEdit", json!({}));
+        }
+        Key::Enter => {
+            let k = typing_key(ui, false);
+            let before = ime_stamp(app, ctx);
+            if exec(app, "text.insert", json!({"text": "\n", "merge": k})).is_some() {
+                note_ime_application_edit(app, ctx, before);
+            }
+        }
+        Key::Tab => {
+            let k = typing_key(ui, false);
+            let before = ime_stamp(app, ctx);
+            if exec(app, "text.insert", json!({"text": "\t", "merge": k})).is_some() {
+                note_ime_application_edit(app, ctx, before);
+            }
+        }
+        Key::Escape => {
+            exec(app, "text.endEdit", json!({}));
+        }
+        // The editor owns exactly Cmd/Ctrl+A (Select All) and Cmd/Ctrl+Z with or
+        // without Shift (Undo, Redo). Other modifiers on those keys aren't editing
+        // chords, so they fall through to the binding match below: Shift+A is
+        // Deselect All's default, and Alt variants are free for a rebound one.
+        Key::A if cmd && !m.shift && !m.alt => {
+            exec(app, "text.setSelection", json!({"select": "all"}));
+        }
+        Key::Z if cmd && !m.alt => {
+            let before = ime_stamp(app, ctx);
+            if crate::menus::invoke(app, ctx, if m.shift { "edit.redo" } else { "edit.undo" }, json!({})).is_ok() {
+                note_ime_application_edit(app, ctx, before);
+            }
+        }
+        Key::Comma | Key::Period if cmd && m.shift => {
+            let doc = layer_doc(&app.session, sel.layer).unwrap_or_default();
+            let r = sel.range();
+            let size = sel.pending.as_ref().map_or_else(|| doc.style_at(r.start).size, |p| p.size);
+            let ns = (size + if key == Key::Period { 2.0 } else { -2.0 }).max(1.0);
+            exec(app, "layer.setText", json!({"layer": sel.layer.0, "range": [r.start, r.end], "size": ns}));
+        }
+        // The app-wide shortcut dispatcher is skipped while this editor holds the
+        // keyboard, so the Deselect All chord (Cmd/Ctrl+Shift+A or F2 by default)
+        // must be matched here and run through the command dispatcher like undo
+        // above. Matching the command's current binding, not a fixed key, keeps
+        // rebound shortcuts working and gives every route one final state; the
+        // forwarding test also refuses chords a focused editor must never surrender
+        // (see `forwardable_during_text_edit`).
+        _ if crate::menus::chord_matches(&app.session, "edit.deselectAll", key, m) && crate::menus::forwardable_during_text_edit(m, key) => {
+            let _ = crate::menus::invoke(app, ctx, "edit.deselectAll", json!({}));
+        }
+        _ => {}
+    }
+    if !matches!(key, Key::Backspace | Key::Delete | Key::Enter | Key::Tab) {
+        typing_key(ui, true);
+    }
+}
+
 /// Delete the text an IME marks for replacement around the editor's selection.
 ///
 /// `before`/`after` count UTF-8 bytes (`DeleteSurroundingBytes`, what winit reports) or
@@ -1424,825 +1458,4 @@ fn draw(app: &mut EffectcraftApp, ui: &mut egui::Ui, painter: &egui::Painter, ma
 }
 
 #[cfg(test)]
-mod tests {
-    //! Incoming IME edits on the custom text editor (the Type tool's own session, not a stock
-    //! `TextEdit`). Winit reports the bytes around the selection *before* the commit it belongs
-    //! to, so the deletion and the insert must share one undo step.
-
-    use super::*;
-    use effectcraft_engine::Session;
-    use effectcraft_engine::commands::text_edit::TextEdit;
-    use serde_json::json;
-
-    fn editor(text: &str, anchor: usize, caret: usize) -> (EffectcraftApp, LayerId) {
-        let mut s = Session::default();
-        s.execute("comp.new", json!({"name": "IME", "width": 160, "height": 90, "duration": 1})).unwrap();
-        let layer = s.execute("layer.newText", json!({"text": text})).unwrap()["layer"].as_u64().unwrap();
-        let lid = LayerId(layer);
-        s.state.text_edit = Some(TextEdit { layer: lid, anchor, caret, ..Default::default() });
-        (EffectcraftApp::new(s), lid)
-    }
-
-    fn doc_text(app: &EffectcraftApp, lid: LayerId) -> String {
-        layer_doc(&app.session, lid).map(|d| d.text).unwrap_or_default()
-    }
-
-    fn feed(app: &mut EffectcraftApp, events: Vec<egui::Event>) {
-        let ctx = egui::Context::default();
-        let raw = egui::RawInput { screen_rect: Some(egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(320.0, 180.0))), events, ..Default::default() };
-        let mut out = ctx.run_ui(raw, |ui| keyboard(app, ui, egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(320.0, 180.0))));
-        out.textures_delta.clear();
-    }
-
-    #[test]
-    fn preedit_preview_is_bounded_on_a_character_boundary() {
-        let text = "é".repeat(MAX_IME_TEXT_BYTES);
-        let capped = bounded_preedit(text);
-        assert!(capped.len() <= MAX_IME_TEXT_BYTES);
-        assert!(capped.is_char_boundary(capped.len()));
-        assert_eq!(capped.len() % "é".len(), 0, "the cap never leaves half a character");
-    }
-
-    /// Ending the edit from another panel clears this viewport's pre-edit. The production path
-    /// used to resolve `viewport_id()` (a context read lock) inside `data_mut` (a write lock);
-    /// that nested context access deadlocked every pass that drew the viewer.
-    #[test]
-    fn ending_an_edit_from_another_panel_clears_the_preedit() {
-        let (mut app, lid) = editor("abc", 0, 0);
-        let session = app.session.state.text_edit.as_ref().map_or(1, |e| e.session);
-        let ctx = egui::Context::default();
-        let mut out = ctx.run_ui(egui::RawInput::default(), |ui| {
-            let viewport = ui.ctx().viewport_id();
-            let preedit = Preedit { owner: ImeOwner { layer: lid, session }, text: "x".into() };
-            ui.data_mut(|d| d.insert_temp(ime_preedit_id(viewport), preedit));
-            panel_clicked(&mut app, ui.ctx(), PanelKind::Timeline);
-            let viewport = ui.ctx().viewport_id();
-            assert!(ui.data(|d| d.get_temp::<Preedit>(ime_preedit_id(viewport))).is_none(), "the ended edit leaves no preview behind");
-        });
-        out.textures_delta.clear();
-        assert!(app.session.state.text_edit.is_none(), "a click in the Timeline ends the text edit");
-    }
-
-    #[test]
-    fn ime_delete_surrounding_bytes_and_the_commit_are_one_undo_step() {
-        // "café😀": the last character is four bytes, so a byte-count deletion that treated bytes
-        // as characters would corrupt the document.
-        let (mut app, lid) = editor("café😀", 5, 5);
-        feed(
-            &mut app,
-            vec![
-                egui::Event::Ime(egui::ImeEvent::DeleteSurroundingBytes { before_bytes: 4, after_bytes: 0 }),
-                egui::Event::Ime(egui::ImeEvent::Commit("X".into())),
-            ],
-        );
-        assert_eq!(doc_text(&app, lid), "caféX", "the emoji is replaced by the committed text");
-        app.session.execute("edit.undo", json!({})).unwrap();
-        assert_eq!(doc_text(&app, lid), "café😀", "the replacement is one undo step");
-    }
-
-    #[test]
-    fn ime_delete_surrounding_chars_keeps_the_selection_for_the_commit() {
-        // Stock egui deletes the characters around the selection, not the selection itself: the
-        // commit that follows replaces "bcd", it does not insert next to a deleted document.
-        let (mut app, lid) = editor("abcdef", 1, 4);
-        feed(&mut app, vec![egui::Event::Ime(egui::ImeEvent::DeleteSurrounding { before_chars: 1, after_chars: 99 })]);
-        assert_eq!(doc_text(&app, lid), "bcd", "one character before and everything after go");
-        let sel = app.session.state.text_edit.clone().expect("editing continues");
-        assert_eq!(sel.range(), 0..3, "the selected text is still selected");
-        // A deletion-only batch (no commit) leaves "bcd", not an empty document.
-        app.session.execute("edit.undo", json!({})).unwrap();
-        assert_eq!(doc_text(&app, lid), "abcdef", "clamped deletion is still one undo step");
-
-        // Delete surround + commit: the commit replaces the kept selection.
-        let (mut app, lid) = editor("abcdef", 1, 4);
-        feed(
-            &mut app,
-            vec![
-                egui::Event::Ime(egui::ImeEvent::DeleteSurrounding { before_chars: 1, after_chars: 99 }),
-                egui::Event::Ime(egui::ImeEvent::Commit("XY".into())),
-            ],
-        );
-        assert_eq!(doc_text(&app, lid), "XY", "the commit replaces the selection");
-        app.session.execute("edit.undo", json!({})).unwrap();
-        assert_eq!(doc_text(&app, lid), "abcdef", "the deletion and its commit are one undo step");
-    }
-
-    /// One UI pass with the editor focused, events applied, and the overlay's observation.
-    struct ImePass {
-        ctx: egui::Context,
-        viewport: egui::ViewportId,
-        rect: egui::Rect,
-    }
-
-    impl ImePass {
-        fn new(viewport: egui::ViewportId) -> Self {
-            let ctx = egui::Context::default();
-            install_hooks(&ctx);
-            Self { ctx, viewport, rect: egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(320.0, 180.0)) }
-        }
-
-        /// Run one `Context` frame. `overlay` is false for a pass in which the viewer (and so
-        /// the edit overlay) never drew; `discard` forces a second pass of the same frame.
-        fn frame(&mut self, app: &mut EffectcraftApp, events: Vec<egui::Event>, overlay: bool, discard: bool) -> Option<egui::output::IMEOutput> {
-            let ctx = self.ctx.clone();
-            let rect = self.rect;
-            let viewport = self.viewport;
-            let mut viewports = egui::ViewportIdMap::default();
-            viewports.insert(self.viewport, egui::ViewportInfo::default());
-            let raw = egui::RawInput { viewport_id: self.viewport, viewports, screen_rect: Some(rect), events, ..Default::default() };
-            let mut asked = false;
-            let mut out = ctx.run_ui(raw, |ui| {
-                begin_ui(ui.ctx());
-                ui.interact(rect, focus_id(), egui::Sense::focusable_noninteractive());
-                ui.memory_mut(|m| m.request_focus(focus_id()));
-                sync_ime_target(ui, app);
-                keyboard(app, ui, rect);
-                if overlay {
-                    let pass = ui.ctx().cumulative_pass_nr_for(viewport);
-                    ui.data_mut(|d| d.insert_temp(ime_geometry_id(viewport), (pass, rect, rect)));
-                }
-                finish_ime(app, ui);
-                if discard && !asked {
-                    asked = true;
-                    ui.ctx().request_discard("ime pass test");
-                }
-            });
-            out.textures_delta.clear();
-            out.platform_output.ime
-        }
-    }
-
-    /// One native floating window holding the Timeline's group and then the Viewer's.
-    fn two_group_window() -> craft_ui::docking::Floating<PanelKind> {
-        let groups = vec![craft_ui::docking::Group::new(vec![PanelKind::Timeline], 0), craft_ui::docking::Group::new(vec![PanelKind::Viewer(1)], 0)];
-        craft_ui::docking::Floating::stack(groups, [0.0, 0.0, 320.0, 360.0]).expect("two groups make a window")
-    }
-
-    impl ImePass {
-        /// One pass of a native window with a body that edits no text and the Viewer's editor,
-        /// in the order given, publishing as `NativeIme` decides or, with `every`, after each
-        /// body. Returns the descriptor and the preedit the pass ended with.
-        fn window(
-            &mut self,
-            app: &mut EffectcraftApp,
-            window: &craft_ui::docking::Floating<PanelKind>,
-            events: Vec<egui::Event>,
-            viewer_first: bool,
-            every: bool,
-        ) -> (Option<egui::output::IMEOutput>, Option<String>) {
-            let ctx = self.ctx.clone();
-            let (rect, viewport) = (self.rect, self.viewport);
-            let mut viewports = egui::ViewportIdMap::default();
-            viewports.insert(viewport, egui::ViewportInfo::default());
-            let raw = egui::RawInput { viewport_id: viewport, viewports, screen_rect: Some(rect), events, ..Default::default() };
-            let mut preedit = None;
-            let mut out = ctx.run_ui(raw, |ui| {
-                let mut ime = crate::dock_ui::NativeIme::new(std::slice::from_ref(window), &[]);
-                let order = if viewer_first { [true, false] } else { [false, true] };
-                for viewer in order {
-                    if ime.begin_body(viewport) {
-                        begin_ui(ui.ctx());
-                    }
-                    if viewer {
-                        ui.interact(rect, focus_id(), egui::Sense::focusable_noninteractive());
-                        ui.memory_mut(|m| m.request_focus(focus_id()));
-                        sync_ime_target(ui, app);
-                        keyboard(app, ui, rect);
-                        let pass = ui.ctx().cumulative_pass_nr_for(viewport);
-                        ui.data_mut(|d| d.insert_temp(ime_geometry_id(viewport), (pass, rect, rect)));
-                    }
-                    if ime.publishes(viewport, ime_recorded(ui.ctx())) || every {
-                        finish_ime(app, ui);
-                    }
-                }
-                assert!(ime.unpublished().is_empty(), "the window published");
-                preedit = read_preedit(ui).map(|p| p.text);
-            });
-            out.textures_delta.clear();
-            (out.platform_output.ime, preedit)
-        }
-    }
-
-    #[test]
-    fn native_window_with_a_group_before_the_viewer_keeps_the_composition() {
-        let window = two_group_window();
-        let viewport = craft_ui::docking::DockArea::<PanelKind>::window_viewport(crate::dock_ui::area_id(), window.id);
-        let preview = || egui::Event::Ime(egui::ImeEvent::Preedit { text: "é".into(), active_range_chars: None });
-        for viewer_first in [false, true] {
-            let (mut app, _) = editor("abcd", 4, 4);
-            let mut pass = ImePass::new(viewport);
-            let (first, preedit) = pass.window(&mut app, &window, vec![preview()], viewer_first, false);
-            let first = first.expect("the editor publishes");
-            assert_eq!(preedit.as_deref(), Some("é"));
-            for _ in 0..2 {
-                let (ime, preedit) = pass.window(&mut app, &window, vec![], viewer_first, false);
-                let ime = ime.expect("the editor keeps publishing");
-                assert!(!ime.should_interrupt_composition, "viewer first: {viewer_first}");
-                assert_eq!((ime.owner, ime.context_generation), (first.owner, first.context_generation), "the same IME context");
-                assert_eq!(preedit.as_deref(), Some("é"), "the preedit survives the other body");
-            }
-        }
-        // Publishing after the body drawn before the Viewer clears the preedit and interrupts.
-        let (mut app, _) = editor("abcd", 4, 4);
-        let mut pass = ImePass::new(viewport);
-        pass.window(&mut app, &window, vec![preview()], false, true);
-        let (ime, preedit) = pass.window(&mut app, &window, vec![], false, true);
-        assert!(ime.expect("the editor publishes").should_interrupt_composition);
-        assert_eq!(preedit, None);
-        // A window that drew fewer bodies than its layout counts publishes after every body in
-        // its next pass.
-        let mut ime = crate::dock_ui::NativeIme::new(std::slice::from_ref(&window), &[]);
-        ime.begin_body(viewport);
-        assert!(!ime.publishes(viewport, false));
-        let unpublished = ime.unpublished();
-        assert_eq!(unpublished, vec![viewport]);
-        let mut ime = crate::dock_ui::NativeIme::new(std::slice::from_ref(&window), &unpublished);
-        ime.begin_body(viewport);
-        assert!(ime.publishes(viewport, false));
-    }
-
-    fn ime_text(ime: &egui::output::IMEOutput) -> (&str, usize, usize) {
-        let p = ime.surrounding_text.available().expect("committed surrounding text");
-        (p.text.as_str(), p.cursor, p.anchor)
-    }
-
-    #[test]
-    fn discarded_custom_request_then_home_rearms_the_identical_caret() {
-        let (mut app, lid) = editor("abcd", 4, 4);
-        app.ui.start_screen = false;
-        app.ui.tool = Tool::Type;
-        app.ui.focused = PanelKind::Composition;
-        let ctx = egui::Context::default();
-        install_hooks(&ctx);
-        let mut frame = eframe::Frame::_new_kittest();
-        let raw = || egui::RawInput { screen_rect: Some(Rect::from_min_size(Pos2::ZERO, vec2(1200.0, 800.0))), ..Default::default() };
-        for _ in 0..3 {
-            let mut output = ctx.run_ui(raw(), |ui| {
-                eframe::App::logic(&mut app, ui.ctx(), &mut frame);
-                app.draw(ui, &frame);
-            });
-            output.textures_delta.clear();
-        }
-        let mut input = raw();
-        input.events.push(egui::Event::Ime(egui::ImeEvent::Preedit { text: "é".into(), active_range_chars: None }));
-        let mut output = ctx.run_ui(input, |ui| {
-            eframe::App::logic(&mut app, ui.ctx(), &mut frame);
-            app.draw(ui, &frame);
-        });
-        output.textures_delta.clear();
-        assert!(output.platform_output.ime.is_some());
-        app.session.execute("text.setSelection", json!({"caret": 1})).unwrap();
-        let selection = app.session.state.text_edit.clone();
-        let mut passes = 0;
-        let mut discarded = None;
-        let mut output = ctx.run_ui(raw(), |ui| {
-            passes += 1;
-            if passes > 1 {
-                app.ui.start_screen = true;
-            }
-            eframe::App::logic(&mut app, ui.ctx(), &mut frame);
-            app.draw(ui, &frame);
-            if passes == 1 {
-                assert!(ui.ctx().output(|output| output.ime.is_some()));
-                discarded = read_reset(ui.ctx()).and_then(|guard| guard.request);
-                ui.ctx().request_discard("custom IME descriptor discarded before Home");
-            }
-        });
-        output.textures_delta.clear();
-        assert!(passes >= 2);
-        let first = discarded.expect("the actual discarded custom pass requested a fence");
-        assert!(output.platform_output.ime.is_none());
-        assert!(read_reset(&ctx).unwrap().suspended);
-        assert!(read_reset(&ctx).unwrap().request.is_none());
-        assert_eq!(app.session.state.text_edit, selection, "Home did not move the model caret");
-        app.ui.start_screen = false;
-        let mut output = ctx.run_ui(raw(), |ui| {
-            eframe::App::logic(&mut app, ui.ctx(), &mut frame);
-            app.draw(ui, &frame);
-        });
-        output.textures_delta.clear();
-        let second = output.platform_output.ime.unwrap().reset_request.expect("same caret reactivation publishes a new real ID");
-        assert_ne!(first, second);
-        let mut output = ctx.run_ui(raw(), |ui| {
-            eframe::App::logic(&mut app, ui.ctx(), &mut frame);
-            app.draw(ui, &frame);
-        });
-        output.textures_delta.clear();
-        assert!(output.platform_output.ime.unwrap().reset_request.is_none());
-        let mut input = raw();
-        input.events.extend([
-            egui::Event::ImeResetCompleted { request_id: first },
-            egui::Event::Ime(egui::ImeEvent::Commit("X".into())),
-            egui::Event::ImeResetCompleted { request_id: second },
-            egui::Event::Ime(egui::ImeEvent::Preedit { text: "が".into(), active_range_chars: None }),
-            egui::Event::Ime(egui::ImeEvent::Commit("が".into())),
-        ]);
-        let mut output = ctx.run_ui(input, |ui| {
-            eframe::App::logic(&mut app, ui.ctx(), &mut frame);
-            app.draw(ui, &frame);
-        });
-        output.textures_delta.clear();
-        assert_eq!(doc_text(&app, lid), "aがbcd");
-    }
-
-    #[test]
-    fn viewport_fences_and_duplicate_completion_keep_their_exact_lifetime() {
-        let (mut app, lid) = editor("abcd", 4, 4);
-        let mut root = ImePass::new(egui::ViewportId::ROOT);
-        let mut detached = ImePass::new(egui::ViewportId::from_hash_of("effect-ime-detached"));
-        let preview = || egui::Event::Ime(egui::ImeEvent::Preedit { text: "é".into(), active_range_chars: None });
-        root.frame(&mut app, vec![preview()], true, false);
-        detached.frame(&mut app, vec![preview()], true, false);
-        app.session.execute("text.setSelection", json!({"caret": 1})).unwrap();
-        let first = root.frame(&mut app, vec![], true, false).unwrap().reset_request.unwrap();
-        let second = detached.frame(&mut app, vec![], true, false).unwrap().reset_request.unwrap();
-        assert_ne!(first, second);
-        detached.frame(&mut app, vec![egui::Event::ImeResetCompleted { request_id: first }, egui::Event::Ime(egui::ImeEvent::Commit("X".into()))], true, false);
-        assert_eq!(doc_text(&app, lid), "abcd");
-        let pending = detached.ctx.data(|data| data.get_temp::<ResetGuard>(reset_id(detached.viewport))).unwrap().request;
-        assert_eq!(pending, Some(second), "a root marker cannot release the detached viewport's full ID");
-        let output = detached
-            .frame(
-                &mut app,
-                vec![
-                    egui::Event::ImeResetCompleted { request_id: second },
-                    preview(),
-                    egui::Event::ImeResetCompleted { request_id: second },
-                    egui::Event::Ime(egui::ImeEvent::Commit("が".into())),
-                ],
-                true,
-                false,
-            )
-            .unwrap();
-        assert_eq!(doc_text(&app, lid), "aがbcd");
-        assert!(output.reset_request.is_none(), "a duplicate control cannot reconstruct the cleared guard");
-        // An actual context-generation change at unchanged selection still supersedes a wait.
-        root.frame(&mut app, vec![], true, false);
-        let replaced = root.frame(&mut app, vec![], false, false);
-        assert!(replaced.is_none());
-        let replacement = root.frame(&mut app, vec![], true, false).unwrap().reset_request.unwrap();
-        assert_ne!(first, replacement);
-    }
-
-    #[test]
-    fn ime_descriptor_sends_committed_text_and_preserves_a_reversed_selection() {
-        let (mut app, _) = editor("café😀", 2, 5);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        let first = pass.frame(&mut app, vec![], true, false).expect("the focused editor owns IME");
-        assert_eq!(first.owner, ime_target(&app).expect("an edit target").owner);
-        assert!(first.context_generation > 0);
-        assert_eq!(ime_text(&first), ("café😀", 9, 2), "UTF-8 bytes, with the caret's direction kept");
-        assert_eq!(first.change_cause, egui::ImeChangeCause::Other, "starting a context is application origin");
-        assert_eq!((first.rect, first.cursor_rect), (pass.rect, pass.rect), "the real caret geometry");
-
-        let again = pass.frame(&mut app, vec![], true, false).expect("still editing");
-        assert_eq!(again.context_generation, first.context_generation, "an unchanged pass keeps the context");
-        assert_eq!(again.surrounding_text, first.surrounding_text);
-    }
-
-    #[test]
-    fn accepted_ime_commit_is_input_method_and_ordinary_typing_is_other() {
-        let (mut app, lid) = editor("ab", 2, 2);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        let first = pass.frame(&mut app, vec![], true, false).expect("editing");
-        let generation = first.context_generation;
-
-        let commit = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("日".into()))], true, false).expect("still editing");
-        assert_eq!(doc_text(&app, lid), "ab日");
-        assert_eq!(ime_text(&commit), ("ab日", 5, 5));
-        assert_eq!(commit.change_cause, egui::ImeChangeCause::InputMethod, "only the accepted commit earns it");
-        assert_eq!(commit.context_generation, generation, "an ordinary text change is not a new context");
-
-        let typed = pass.frame(&mut app, vec![egui::Event::Text("x".into())], true, false).expect("still editing");
-        assert_eq!(doc_text(&app, lid), "ab日x");
-        assert_eq!(typed.change_cause, egui::ImeChangeCause::Other, "typing is application work");
-        assert_eq!(typed.context_generation, generation);
-    }
-
-    #[test]
-    fn ime_delete_and_commit_chain_is_input_method_with_a_reversed_selection() {
-        let (mut app, lid) = editor("abcdef", 4, 1);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        pass.frame(&mut app, vec![], true, false).expect("editing");
-
-        let deleted = pass
-            .frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::DeleteSurrounding { before_chars: 1, after_chars: 1 })], true, false)
-            .expect("still editing");
-        assert_eq!(doc_text(&app, lid), "bcdf", "one character goes before and one after the selection");
-        assert_eq!(ime_text(&deleted), ("bcdf", 0, 3), "the selected text and its reversed direction stay");
-        assert_eq!(deleted.change_cause, egui::ImeChangeCause::InputMethod);
-
-        let committed = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("X".into()))], true, false).expect("still editing");
-        assert_eq!(doc_text(&app, lid), "Xf", "the commit replaces the kept selection");
-        assert_eq!(committed.change_cause, egui::ImeChangeCause::InputMethod, "the delete and commit are one accepted chain");
-        app.session.execute("edit.undo", json!({})).unwrap();
-        assert_eq!(doc_text(&app, lid), "abcdef", "the replacement is one undo step");
-    }
-
-    #[test]
-    fn an_application_edit_in_the_same_frame_dominates_the_ime_cause() {
-        // Application edit before the IME commit.
-        let (mut app, lid) = editor("ab", 2, 2);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        pass.frame(&mut app, vec![], true, false).expect("editing");
-        let mixed = pass
-            .frame(&mut app, vec![egui::Event::Text("x".into()), egui::Event::Ime(egui::ImeEvent::Commit("日".into()))], true, false)
-            .expect("still editing");
-        assert_eq!(doc_text(&app, lid), "abx日");
-        assert_eq!(mixed.change_cause, egui::ImeChangeCause::Other, "the earlier application edit dominates");
-
-        // Application edit after the IME commit.
-        let (mut app, lid) = editor("ab", 2, 2);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        pass.frame(&mut app, vec![], true, false).expect("editing");
-        let mixed = pass
-            .frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("日".into())), egui::Event::Text("x".into())], true, false)
-            .expect("still editing");
-        assert_eq!(doc_text(&app, lid), "ab日x");
-        assert_eq!(mixed.change_cause, egui::ImeChangeCause::Other, "the later application edit dominates");
-    }
-
-    #[test]
-    fn preedit_is_excluded_from_the_committed_snapshot_and_keeps_the_context() {
-        let (mut app, lid) = editor("ab", 2, 2);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        let first = pass.frame(&mut app, vec![], true, false).expect("editing");
-
-        let preview = pass
-            .frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false)
-            .expect("still editing");
-        assert_eq!(doc_text(&app, lid), "ab", "the pre-edit never enters the document");
-        assert_eq!(ime_text(&preview), ("ab", 2, 2), "only committed text is sent");
-        assert_eq!(preview.context_generation, first.context_generation, "pre-edit updates keep the composition");
-
-        let commit = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("に".into()))], true, false).expect("still editing");
-        assert_eq!(doc_text(&app, lid), "abに");
-        assert_eq!(commit.change_cause, egui::ImeChangeCause::InputMethod, "clearing the pre-edit and committing is IME work");
-        assert_eq!(commit.context_generation, first.context_generation);
-    }
-
-    #[test]
-    fn empty_and_unavailable_surrounding_text_are_distinct() {
-        let (mut app, _) = editor("", 0, 0);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        let empty = pass.frame(&mut app, vec![], true, false).expect("editing");
-        assert_eq!(ime_text(&empty), ("", 0, 0), "an available-empty document is not unavailable");
-
-        let text = "a".repeat(5000);
-        let (mut app, _) = editor(&text, 0, 5000);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        let wide = pass.frame(&mut app, vec![], true, false).expect("editing");
-        assert!(matches!(wide.surrounding_text, egui::output::IMESurroundingText::Unavailable), "a selection wider than the limit is unavailable");
-        assert_eq!(wide.owner, ime_target(&app).expect("an edit target").owner, "identity survives unavailable text");
-    }
-
-    #[test]
-    fn an_unrelated_undo_keeps_a_wide_selection_composition() {
-        // A selection wider than the IME limit reports unavailable surrounding text, whose
-        // receipt identity is a revision. That revision must follow the editor, not the whole
-        // project: undoing an unrelated opacity change used to look like an editor mutation and
-        // cancel an active composition.
-        let text = "a".repeat(5000);
-        let (mut app, lid) = editor(&text, 0, 5000);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        let first = pass.frame(&mut app, vec![], true, false).expect("editing");
-        assert!(matches!(first.surrounding_text, egui::output::IMESurroundingText::Unavailable), "the wide selection is unavailable");
-
-        let composing = pass
-            .frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false)
-            .expect("still editing");
-        assert_eq!(composing.context_generation, first.context_generation, "the pre-edit keeps the context");
-        let owner = ime_owner(&app).expect("an editor owner");
-        assert!(matches!(
-            pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))),
-            Some(ImeComposition::Active(active)) if active == owner
-        ));
-
-        app.session.execute("prop.set", json!({"layer": lid.0, "path": "transform/opacity", "value": 50})).unwrap();
-        app.session.execute("edit.undo", json!({})).unwrap();
-        let after = pass.frame(&mut app, vec![], true, false).expect("still editing");
-        assert_eq!(after.context_generation, first.context_generation, "an unrelated undo does not start a new context");
-        assert!(
-            matches!(
-                pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))),
-                Some(ImeComposition::Active(active)) if active == owner
-            ),
-            "the wide-selection composition survives an unrelated undo"
-        );
-        assert!(read_reset(&pass.ctx).is_none(), "no IME reset was requested");
-
-        // The composition is still the live one: its commit is accepted and earns the
-        // input-method cause rather than being poisoned as leftover application work.
-        let commit = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("x".into()))], true, false).expect("still editing");
-        assert_eq!(doc_text(&app, lid), "x", "the preserved composition commits into the wide selection");
-        assert_eq!(commit.change_cause, egui::ImeChangeCause::InputMethod);
-    }
-
-    #[test]
-    fn a_failed_batch_with_a_transient_edit_does_not_revive_a_wide_selection_composition() {
-        // The final document equals the pre-batch one, but the intermediate insert/delete was a
-        // real document change. Its IME revision must stay the high-water mark; otherwise the
-        // active wide-selection composition would look current and accept its old commit.
-        let text = "a".repeat(5000);
-        let (mut app, lid) = editor(&text, 0, 5000);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        pass.frame(&mut app, vec![], true, false).expect("editing");
-        pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false)
-            .expect("still editing");
-        let owner = ime_owner(&app).expect("an editor owner");
-        assert!(matches!(
-            pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))),
-            Some(ImeComposition::Active(active)) if active == owner
-        ));
-
-        let r = app.session.execute(
-            "engine.batch",
-            json!({"atomic": true, "steps": [
-                {"command": "text.insert", "params": {"text": "x", "range": [5000, 5000]}},
-                {"command": "text.delete", "params": {}},
-                {"command": "no.suchCommand", "params": {}}
-            ]}),
-        );
-        assert!(r.is_err());
-        assert_eq!(doc_text(&app, lid), text, "the batch restored the final document");
-
-        pass.frame(&mut app, vec![], true, false).expect("still editing");
-        assert!(read_reset(&pass.ctx).is_some(), "the advanced revision retires the old IME context");
-        assert!(
-            matches!(pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))), Some(ImeComposition::Stale)),
-            "the failed batch's transient edit leaves the old composition stale"
-        );
-        let stale = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("z".into()))], true, false).expect("still editing");
-        assert_eq!(doc_text(&app, lid), text, "the stale composition cannot commit into the restored document");
-        assert_ne!(stale.change_cause, egui::ImeChangeCause::InputMethod, "a rejected commit earns no IME receipt");
-    }
-
-    #[test]
-    fn a_wide_content_change_invalidates_the_active_composition() {
-        let text = "a".repeat(5000);
-        let (mut app, lid) = editor(&text, 0, 5000);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        pass.frame(&mut app, vec![], true, false).expect("editing");
-        pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false)
-            .expect("still editing");
-
-        let replaced = "b".repeat(5000);
-        app.session.execute("layer.setText", json!({"layer": lid.0, "text": replaced})).unwrap();
-        let after = pass.frame(&mut app, vec![], true, false).expect("still editing");
-        assert_eq!(doc_text(&app, lid), replaced);
-        assert!(after.should_interrupt_composition, "replacing the wide document starts a new IME context");
-        assert!(
-            matches!(pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))), Some(ImeComposition::Stale)),
-            "the old composition is stale after the content change"
-        );
-        pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("z".into()))], true, false).expect("still editing");
-        assert_eq!(doc_text(&app, lid), replaced, "a delayed commit from the old document is rejected");
-    }
-
-    #[test]
-    fn a_wide_selection_change_invalidates_the_active_composition() {
-        let text = "a".repeat(5000);
-        let (mut app, lid) = editor(&text, 0, 5000);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        pass.frame(&mut app, vec![], true, false).expect("editing");
-        pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false)
-            .expect("still editing");
-
-        // Still wider than the IME window limit, so this exercises the unavailable-text
-        // selection identity rather than merely making the surrounding text available.
-        app.session.execute("text.setSelection", json!({"start": 0, "end": 4500})).unwrap();
-        pass.frame(&mut app, vec![], true, false).expect("still editing");
-        assert!(read_reset(&pass.ctx).is_some(), "an application selection change retires the composition");
-        assert!(
-            matches!(pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))), Some(ImeComposition::Stale)),
-            "the old composition cannot follow the selection"
-        );
-        pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("z".into()))], true, false).expect("still editing");
-        assert_eq!(doc_text(&app, lid), text, "the stale composition cannot mutate the wide selection");
-    }
-
-    #[test]
-    fn replaced_edit_session_and_hidden_passes_start_a_new_context() {
-        let (mut app, _) = editor("text", 4, 4);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        let before = pass.frame(&mut app, vec![], true, false).expect("editing");
-        if let Some(edit) = app.session.state.text_edit.as_mut() {
-            edit.session = edit.session.wrapping_add(1);
-        }
-        let replaced = pass.frame(&mut app, vec![], true, false).expect("editing");
-        assert!(replaced.context_generation > before.context_generation, "a recreated target does not inherit the old context");
-        assert_eq!(replaced.change_cause, egui::ImeChangeCause::Other);
-        assert!(replaced.should_interrupt_composition, "a new replacement epoch cancels the platform composition");
-
-        let (mut app, _) = editor("abc", 3, 3);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        let visible = pass.frame(&mut app, vec![], true, false).expect("editing");
-        assert!(pass.frame(&mut app, vec![], false, false).is_none(), "a hidden editor reports no IME owner");
-        let back = pass.frame(&mut app, vec![], true, false).expect("editing again");
-        assert!(back.context_generation > visible.context_generation, "reappearing starts exactly one new context");
-    }
-
-    #[test]
-    fn preedit_from_a_replaced_target_cannot_commit_into_the_new_session() {
-        let (mut app, first) = editor("A", 1, 1);
-        let second = app.session.execute("layer.newText", json!({"text": "B"})).unwrap()["layer"].as_u64().unwrap();
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "か".into(), active_range_chars: None })], true, false)
-            .expect("editing the first layer");
-
-        app.session.execute("text.edit", json!({"layer": second, "caret": 1})).unwrap();
-        let switched = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("日".into()))], true, false).expect("editing the second layer");
-        assert_eq!(doc_text(&app, LayerId(second)), "B", "a delayed commit from the old composition is ignored");
-        assert_eq!(doc_text(&app, first), "A", "the old layer is not changed either");
-        assert_eq!(switched.owner, ime_target(&app).expect("second target").owner);
-        assert!(switched.should_interrupt_composition, "the target switch interrupts the old composition");
-    }
-
-    #[test]
-    fn hidden_pass_clears_this_viewports_preedit_preview() {
-        let (mut app, _) = editor("ab", 2, 2);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false).expect("editing");
-        assert!(pass.ctx.data(|d| d.get_temp::<Preedit>(ime_preedit_id(pass.viewport))).is_some());
-        assert!(pass.frame(&mut app, vec![], false, false).is_none());
-        assert!(pass.ctx.data(|d| d.get_temp::<Preedit>(ime_preedit_id(pass.viewport))).is_none(), "a pass without the overlay clears this viewport's preview");
-    }
-
-    #[test]
-    fn a_discarded_pass_keeps_the_frame_cause_and_the_context() {
-        let (mut app, lid) = editor("ab", 2, 2);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        let first = pass.frame(&mut app, vec![], true, false).expect("editing");
-        let committed = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("日".into()))], true, true).expect("the final pass of the frame");
-        assert_eq!(doc_text(&app, lid), "ab日", "the discarded pass did not replay the event");
-        assert_eq!(committed.change_cause, egui::ImeChangeCause::InputMethod, "an unchanged later pass keeps the frame's cause");
-        assert_eq!(committed.context_generation, first.context_generation, "both passes are one context");
-    }
-
-    #[test]
-    fn two_viewports_keep_independent_ime_contexts() {
-        let (mut app, _) = editor("ab", 2, 2);
-        let mut first = ImePass::new(egui::ViewportId::ROOT);
-        let mut second = ImePass::new(egui::ViewportId::from_hash_of("ime-test-second-viewport"));
-        let one = first.frame(&mut app, vec![], true, false).expect("editing in the first viewport");
-        let two = second.frame(&mut app, vec![], true, false).expect("editing in the second viewport");
-        assert_ne!(one.context_generation, two.context_generation, "each viewport has its own generation");
-        let again = first.frame(&mut app, vec![], true, false).expect("editing in the first viewport");
-        assert_eq!(again.context_generation, one.context_generation, "the second viewport did not disturb the first");
-    }
-
-    /// Draw one real `EffectcraftApp::draw` pass, so `draw`'s all-exit finalizer runs.
-    fn draw_app_pass(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame, events: Vec<egui::Event>) -> egui::FullOutput {
-        let raw = egui::RawInput { screen_rect: Some(egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(1200.0, 800.0))), events, ..Default::default() };
-        let mut out = ctx.run_ui(raw, |ui| app.draw(ui, frame));
-        out.textures_delta.clear();
-        out
-    }
-
-    /// One headless pass with the custom viewer and a real stock `TextEdit` side by side.
-    ///
-    /// The first call focuses the custom editor before `keyboard` (the outside press arrives
-    /// there). The second call leaves the stock field's focus alone, so the stock descriptor
-    /// is published by the same `output.ime` writer that an unrelated field would use.
-    fn stock_pass(
-        pass: &mut ImePass,
-        app: &mut EffectcraftApp,
-        events: Vec<egui::Event>,
-        stock: &mut String,
-        custom_focus: bool,
-    ) -> Option<egui::output::IMEOutput> {
-        let ctx = pass.ctx.clone();
-        let viewport = pass.viewport;
-        let custom = egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(160.0, 90.0));
-        let stock_rect = egui::Rect::from_min_size(egui::pos2(180.0, 30.0), egui::vec2(120.0, 24.0));
-        let stock_id = egui::Id::unique("effectcraft-ime-test-stock");
-        let mut viewports = egui::ViewportIdMap::default();
-        viewports.insert(viewport, egui::ViewportInfo::default());
-        let raw = egui::RawInput { viewport_id: viewport, viewports, screen_rect: Some(pass.rect), events, ..Default::default() };
-        let mut out = ctx.run_ui(raw, |ui| {
-            begin_ui(ui.ctx());
-            if custom_focus {
-                ui.interact(custom, focus_id(), egui::Sense::focusable_noninteractive());
-                ui.memory_mut(|m| m.request_focus(focus_id()));
-                sync_ime_target(ui, app);
-                keyboard(app, ui, custom);
-            } else {
-                // The stock field holds focus after the outside press; keep that ownership while
-                // the second pass publishes the actual stock descriptor.
-                ui.memory_mut(|m| m.request_focus(stock_id));
-            }
-            let _ = ui.put(stock_rect, egui::TextEdit::singleline(stock).id(stock_id));
-            finish_ime(app, ui);
-        });
-        out.textures_delta.clear();
-        out.platform_output.ime
-    }
-
-    #[test]
-    fn outside_pointer_to_stock_allocates_no_new_request_and_defers_the_replacement() {
-        let (mut app, lid) = editor("abcd", 4, 4);
-        let mut pass = ImePass::new(egui::ViewportId::ROOT);
-        let preview = || egui::Event::Ime(egui::ImeEvent::Preedit { text: "é".into(), active_range_chars: None });
-        pass.frame(&mut app, vec![preview()], true, false).expect("the custom editor starts a composition");
-        app.session.execute("text.setSelection", json!({"caret": 1})).unwrap();
-        let first = pass.frame(&mut app, vec![], true, false).expect("the caret change publishes a request").reset_request.expect("the real request ID");
-        // Complete the first interruption, then start a fresh composition with no waiting guard.
-        pass.frame(&mut app, vec![egui::Event::ImeResetCompleted { request_id: first }], true, false);
-        let active = pass.frame(&mut app, vec![preview()], true, false).expect("a fresh composition");
-        assert!(active.reset_request.is_none(), "a fresh composition does not wait on an old request");
-        assert_eq!(doc_text(&app, lid), "abcd");
-
-        // The press outside the viewer also gives the stock field focus. It must not allocate a
-        // new request: core would attach that request to the stock descriptor next pass.
-        let outside = egui::pos2(240.0, 42.0);
-        let mut stock = String::new();
-        stock_pass(
-            &mut pass,
-            &mut app,
-            vec![
-                egui::Event::PointerMoved(outside),
-                egui::Event::PointerButton { pos: outside, button: egui::PointerButton::Primary, pressed: true, modifiers: egui::Modifiers::NONE },
-            ],
-            &mut stock,
-            true,
-        );
-        let guard = pass.ctx.data(|d| d.get_temp::<ResetGuard>(reset_id(pass.viewport))).expect("the custom guard is retired locally");
-        assert!(guard.suspended && guard.request.is_none(), "the outside press retires the old request without allocating another");
-        let stock_ime = stock_pass(&mut pass, &mut app, vec![], &mut stock, false).expect("the actual stock field owns IME");
-        assert_ne!(stock_ime.owner, ime_target(&app).expect("the custom target is still live").owner);
-        assert!(stock_ime.reset_request.is_none(), "a new outside-press request would surface on the stock output");
-        assert_eq!(doc_text(&app, lid), "abcd");
-
-        // Returning to a confirmed eligible custom output allocates the one replacement.
-        let replacement = pass.frame(&mut app, vec![], true, false).expect("the custom editor owns IME again").reset_request.expect("the deferred replacement");
-        assert_ne!(first, replacement);
-        assert!(pass.frame(&mut app, vec![], true, false).expect("still editing").reset_request.is_none(), "the replacement is one-shot");
-    }
-
-    #[test]
-    fn fonts_and_device_loss_all_exit_finalizers_suspend_without_allocating() {
-        let (mut app, _lid) = editor("abcd", 1, 1);
-        app.ui.start_screen = false;
-        app.ui.tool = Tool::Type;
-        app.ui.focused = PanelKind::Composition;
-        app.show_panel(PanelKind::Composition);
-        let ctx = egui::Context::default();
-        install_hooks(&ctx);
-        let frame = eframe::Frame::_new_kittest();
-        let preview = || egui::Event::Ime(egui::ImeEvent::Preedit { text: "é".into(), active_range_chars: None });
-        // The first pass installs fonts and the next draws the real viewer.
-        for _ in 0..3 {
-            draw_app_pass(&mut app, &ctx, &frame, vec![]);
-        }
-        draw_app_pass(&mut app, &ctx, &frame, vec![preview()]);
-        app.session.execute("text.setSelection", json!({"caret": 2})).unwrap();
-        let first = draw_app_pass(&mut app, &ctx, &frame, vec![])
-            .platform_output
-            .ime
-            .expect("the normal pass publishes the custom descriptor")
-            .reset_request
-            .expect("one request for the caret interruption");
-
-        // A real font-install pass draws nothing, but `draw` still reaches the finalizer.
-        app.styled = false;
-        let fonts = draw_app_pass(&mut app, &ctx, &frame, vec![]);
-        assert!(!app.is_ready(), "the font-install pass cannot draw");
-        assert!(fonts.platform_output.ime.is_none(), "no custom descriptor is published");
-        let guard = ctx.data(|d| d.get_temp::<ResetGuard>(reset_id(egui::ViewportId::ROOT))).expect("the waiting guard");
-        assert!(guard.suspended && guard.request.is_none(), "the all-exit finalizer retired it without allocating");
-        let second = draw_app_pass(&mut app, &ctx, &frame, vec![])
-            .platform_output
-            .ime
-            .expect("returning to a drawing pass publishes the custom descriptor")
-            .reset_request
-            .expect("the deferred request");
-        assert_ne!(first, second);
-
-        // The device-loss early return is the other all-exit path. Preset the close bookkeeping
-        // so this test does not autosave; the pass must still retire the waiting guard.
-        app.gpu_failure_applied = Some(true);
-        app.device_lost_close = Some(true);
-        let lost = draw_app_pass(&mut app, &ctx, &frame, vec![]);
-        assert!(lost.platform_output.ime.is_none(), "a lost renderer publishes no descriptor");
-        let guard = ctx.data(|d| d.get_temp::<ResetGuard>(reset_id(egui::ViewportId::ROOT))).expect("the waiting guard");
-        assert!(guard.suspended && guard.request.is_none(), "the device-loss finalizer retired it without allocating");
-        app.gpu_failure_applied = None;
-        let third = draw_app_pass(&mut app, &ctx, &frame, vec![])
-            .platform_output
-            .ime
-            .expect("a drawing pass publishes the custom descriptor again")
-            .reset_request
-            .expect("the deferred request is one-shot");
-        assert_ne!(third, second);
-    }
-
-    #[test]
-    fn ime_delete_without_a_session_or_with_an_empty_range_does_nothing() {
-        let (mut app, lid) = editor("abc", 1, 1);
-        feed(&mut app, vec![egui::Event::Ime(egui::ImeEvent::DeleteSurroundingBytes { before_bytes: 0, after_bytes: 0 })]);
-        assert_eq!(doc_text(&app, lid), "abc");
-        app.session.state.text_edit = None;
-        feed(&mut app, vec![egui::Event::Ime(egui::ImeEvent::DeleteSurroundingBytes { before_bytes: 2, after_bytes: 0 })]);
-        assert_eq!(doc_text(&app, lid), "abc");
-    }
-}
+mod tests;
diff --git a/crates/ui-egui/src/panels/viewer_text/tests.rs b/crates/ui-egui/src/panels/viewer_text/tests.rs
new file mode 100644
index 000000000..be3e84b2c
--- /dev/null
+++ b/crates/ui-egui/src/panels/viewer_text/tests.rs
@@ -0,0 +1,812 @@
+//! Incoming IME edits on the custom text editor (the Type tool's own session, not a stock
+//! `TextEdit`). Winit reports the bytes around the selection *before* the commit it belongs
+//! to, so the deletion and the insert must share one undo step.
+
+use super::*;
+use effectcraft_engine::Session;
+use effectcraft_engine::commands::text_edit::TextEdit;
+use serde_json::json;
+
+fn editor(text: &str, anchor: usize, caret: usize) -> (EffectcraftApp, LayerId) {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "IME", "width": 160, "height": 90, "duration": 1})).unwrap();
+    let layer = s.execute("layer.newText", json!({"text": text})).unwrap()["layer"].as_u64().unwrap();
+    let lid = LayerId(layer);
+    s.state.text_edit = Some(TextEdit { layer: lid, anchor, caret, ..Default::default() });
+    (EffectcraftApp::new(s), lid)
+}
+
+fn doc_text(app: &EffectcraftApp, lid: LayerId) -> String {
+    layer_doc(&app.session, lid).map(|d| d.text).unwrap_or_default()
+}
+
+fn feed(app: &mut EffectcraftApp, events: Vec<egui::Event>) {
+    let ctx = egui::Context::default();
+    let raw = egui::RawInput { screen_rect: Some(egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(320.0, 180.0))), events, ..Default::default() };
+    let mut out = ctx.run_ui(raw, |ui| keyboard(app, ui, egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(320.0, 180.0))));
+    out.textures_delta.clear();
+}
+
+#[test]
+fn preedit_preview_is_bounded_on_a_character_boundary() {
+    let text = "é".repeat(MAX_IME_TEXT_BYTES);
+    let capped = bounded_preedit(text);
+    assert!(capped.len() <= MAX_IME_TEXT_BYTES);
+    assert!(capped.is_char_boundary(capped.len()));
+    assert_eq!(capped.len() % "é".len(), 0, "the cap never leaves half a character");
+}
+
+/// Ending the edit from another panel clears this viewport's pre-edit. The production path
+/// used to resolve `viewport_id()` (a context read lock) inside `data_mut` (a write lock);
+/// that nested context access deadlocked every pass that drew the viewer.
+#[test]
+fn ending_an_edit_from_another_panel_clears_the_preedit() {
+    let (mut app, lid) = editor("abc", 0, 0);
+    let session = app.session.state.text_edit.as_ref().map_or(1, |e| e.session);
+    let ctx = egui::Context::default();
+    let mut out = ctx.run_ui(egui::RawInput::default(), |ui| {
+        let viewport = ui.ctx().viewport_id();
+        let preedit = Preedit { owner: ImeOwner { layer: lid, session }, text: "x".into() };
+        ui.data_mut(|d| d.insert_temp(ime_preedit_id(viewport), preedit));
+        panel_clicked(&mut app, ui.ctx(), PanelKind::Timeline);
+        let viewport = ui.ctx().viewport_id();
+        assert!(ui.data(|d| d.get_temp::<Preedit>(ime_preedit_id(viewport))).is_none(), "the ended edit leaves no preview behind");
+    });
+    out.textures_delta.clear();
+    assert!(app.session.state.text_edit.is_none(), "a click in the Timeline ends the text edit");
+}
+
+#[test]
+fn ime_delete_surrounding_bytes_and_the_commit_are_one_undo_step() {
+    // "café😀": the last character is four bytes, so a byte-count deletion that treated bytes
+    // as characters would corrupt the document.
+    let (mut app, lid) = editor("café😀", 5, 5);
+    feed(
+        &mut app,
+        vec![
+            egui::Event::Ime(egui::ImeEvent::DeleteSurroundingBytes { before_bytes: 4, after_bytes: 0 }),
+            egui::Event::Ime(egui::ImeEvent::Commit("X".into())),
+        ],
+    );
+    assert_eq!(doc_text(&app, lid), "caféX", "the emoji is replaced by the committed text");
+    app.session.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(doc_text(&app, lid), "café😀", "the replacement is one undo step");
+}
+
+#[test]
+fn ime_delete_surrounding_chars_keeps_the_selection_for_the_commit() {
+    // Stock egui deletes the characters around the selection, not the selection itself: the
+    // commit that follows replaces "bcd", it does not insert next to a deleted document.
+    let (mut app, lid) = editor("abcdef", 1, 4);
+    feed(&mut app, vec![egui::Event::Ime(egui::ImeEvent::DeleteSurrounding { before_chars: 1, after_chars: 99 })]);
+    assert_eq!(doc_text(&app, lid), "bcd", "one character before and everything after go");
+    let sel = app.session.state.text_edit.clone().expect("editing continues");
+    assert_eq!(sel.range(), 0..3, "the selected text is still selected");
+    // A deletion-only batch (no commit) leaves "bcd", not an empty document.
+    app.session.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(doc_text(&app, lid), "abcdef", "clamped deletion is still one undo step");
+
+    // Delete surround + commit: the commit replaces the kept selection.
+    let (mut app, lid) = editor("abcdef", 1, 4);
+    feed(
+        &mut app,
+        vec![egui::Event::Ime(egui::ImeEvent::DeleteSurrounding { before_chars: 1, after_chars: 99 }), egui::Event::Ime(egui::ImeEvent::Commit("XY".into()))],
+    );
+    assert_eq!(doc_text(&app, lid), "XY", "the commit replaces the selection");
+    app.session.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(doc_text(&app, lid), "abcdef", "the deletion and its commit are one undo step");
+}
+
+/// One UI pass with the editor focused, events applied, and the overlay's observation.
+struct ImePass {
+    ctx: egui::Context,
+    viewport: egui::ViewportId,
+    rect: egui::Rect,
+}
+
+impl ImePass {
+    fn new(viewport: egui::ViewportId) -> Self {
+        let ctx = egui::Context::default();
+        install_hooks(&ctx);
+        Self { ctx, viewport, rect: egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(320.0, 180.0)) }
+    }
+
+    /// Run one `Context` frame. `overlay` is false for a pass in which the viewer (and so
+    /// the edit overlay) never drew; `discard` forces a second pass of the same frame.
+    fn frame(&mut self, app: &mut EffectcraftApp, events: Vec<egui::Event>, overlay: bool, discard: bool) -> Option<egui::output::IMEOutput> {
+        let ctx = self.ctx.clone();
+        let rect = self.rect;
+        let viewport = self.viewport;
+        let mut viewports = egui::ViewportIdMap::default();
+        viewports.insert(self.viewport, egui::ViewportInfo::default());
+        let raw = egui::RawInput { viewport_id: self.viewport, viewports, screen_rect: Some(rect), events, ..Default::default() };
+        let mut asked = false;
+        let mut out = ctx.run_ui(raw, |ui| {
+            begin_ui(ui.ctx());
+            ui.interact(rect, focus_id(), egui::Sense::focusable_noninteractive());
+            ui.memory_mut(|m| m.request_focus(focus_id()));
+            sync_ime_target(ui, app);
+            keyboard(app, ui, rect);
+            if overlay {
+                let pass = ui.ctx().cumulative_pass_nr_for(viewport);
+                ui.data_mut(|d| d.insert_temp(ime_geometry_id(viewport), (pass, rect, rect)));
+            }
+            finish_ime(app, ui);
+            if discard && !asked {
+                asked = true;
+                ui.ctx().request_discard("ime pass test");
+            }
+        });
+        out.textures_delta.clear();
+        out.platform_output.ime
+    }
+}
+
+/// One native floating window holding the Timeline's group and then the Viewer's.
+fn two_group_window() -> craft_ui::docking::Floating<PanelKind> {
+    let groups = vec![craft_ui::docking::Group::new(vec![PanelKind::Timeline], 0), craft_ui::docking::Group::new(vec![PanelKind::Viewer(1)], 0)];
+    craft_ui::docking::Floating::stack(groups, [0.0, 0.0, 320.0, 360.0]).expect("two groups make a window")
+}
+
+impl ImePass {
+    /// One pass of a native window with a body that edits no text and the Viewer's editor,
+    /// in the order given, publishing as `NativeIme` decides or, with `every`, after each
+    /// body. Returns the descriptor and the preedit the pass ended with.
+    fn window(
+        &mut self,
+        app: &mut EffectcraftApp,
+        window: &craft_ui::docking::Floating<PanelKind>,
+        events: Vec<egui::Event>,
+        viewer_first: bool,
+        every: bool,
+    ) -> (Option<egui::output::IMEOutput>, Option<String>) {
+        let ctx = self.ctx.clone();
+        let (rect, viewport) = (self.rect, self.viewport);
+        let mut viewports = egui::ViewportIdMap::default();
+        viewports.insert(viewport, egui::ViewportInfo::default());
+        let raw = egui::RawInput { viewport_id: viewport, viewports, screen_rect: Some(rect), events, ..Default::default() };
+        let mut preedit = None;
+        let mut out = ctx.run_ui(raw, |ui| {
+            let mut ime = crate::dock_ui::NativeIme::new(std::slice::from_ref(window), &[]);
+            let order = if viewer_first { [true, false] } else { [false, true] };
+            for viewer in order {
+                if ime.begin_body(viewport) {
+                    begin_ui(ui.ctx());
+                }
+                if viewer {
+                    ui.interact(rect, focus_id(), egui::Sense::focusable_noninteractive());
+                    ui.memory_mut(|m| m.request_focus(focus_id()));
+                    sync_ime_target(ui, app);
+                    keyboard(app, ui, rect);
+                    let pass = ui.ctx().cumulative_pass_nr_for(viewport);
+                    ui.data_mut(|d| d.insert_temp(ime_geometry_id(viewport), (pass, rect, rect)));
+                }
+                if ime.publishes(viewport, ime_recorded(ui.ctx())) || every {
+                    finish_ime(app, ui);
+                }
+            }
+            assert!(ime.unpublished().is_empty(), "the window published");
+            preedit = read_preedit(ui).map(|p| p.text);
+        });
+        out.textures_delta.clear();
+        (out.platform_output.ime, preedit)
+    }
+}
+
+#[test]
+fn native_window_with_a_group_before_the_viewer_keeps_the_composition() {
+    let window = two_group_window();
+    let viewport = craft_ui::docking::DockArea::<PanelKind>::window_viewport(crate::dock_ui::area_id(), window.id);
+    let preview = || egui::Event::Ime(egui::ImeEvent::Preedit { text: "é".into(), active_range_chars: None });
+    for viewer_first in [false, true] {
+        let (mut app, _) = editor("abcd", 4, 4);
+        let mut pass = ImePass::new(viewport);
+        let (first, preedit) = pass.window(&mut app, &window, vec![preview()], viewer_first, false);
+        let first = first.expect("the editor publishes");
+        assert_eq!(preedit.as_deref(), Some("é"));
+        for _ in 0..2 {
+            let (ime, preedit) = pass.window(&mut app, &window, vec![], viewer_first, false);
+            let ime = ime.expect("the editor keeps publishing");
+            assert!(!ime.should_interrupt_composition, "viewer first: {viewer_first}");
+            assert_eq!((ime.owner, ime.context_generation), (first.owner, first.context_generation), "the same IME context");
+            assert_eq!(preedit.as_deref(), Some("é"), "the preedit survives the other body");
+        }
+    }
+    // Publishing after the body drawn before the Viewer clears the preedit and interrupts.
+    let (mut app, _) = editor("abcd", 4, 4);
+    let mut pass = ImePass::new(viewport);
+    pass.window(&mut app, &window, vec![preview()], false, true);
+    let (ime, preedit) = pass.window(&mut app, &window, vec![], false, true);
+    assert!(ime.expect("the editor publishes").should_interrupt_composition);
+    assert_eq!(preedit, None);
+    // A window that drew fewer bodies than its layout counts publishes after every body in
+    // its next pass.
+    let mut ime = crate::dock_ui::NativeIme::new(std::slice::from_ref(&window), &[]);
+    ime.begin_body(viewport);
+    assert!(!ime.publishes(viewport, false));
+    let unpublished = ime.unpublished();
+    assert_eq!(unpublished, vec![viewport]);
+    let mut ime = crate::dock_ui::NativeIme::new(std::slice::from_ref(&window), &unpublished);
+    ime.begin_body(viewport);
+    assert!(ime.publishes(viewport, false));
+}
+
+fn ime_text(ime: &egui::output::IMEOutput) -> (&str, usize, usize) {
+    let p = ime.surrounding_text.available().expect("committed surrounding text");
+    (p.text.as_str(), p.cursor, p.anchor)
+}
+
+#[test]
+fn discarded_custom_request_then_home_rearms_the_identical_caret() {
+    let (mut app, lid) = editor("abcd", 4, 4);
+    app.ui.start_screen = false;
+    app.ui.tool = Tool::Type;
+    app.ui.focused = PanelKind::Composition;
+    let ctx = egui::Context::default();
+    install_hooks(&ctx);
+    let mut frame = eframe::Frame::_new_kittest();
+    let raw = || egui::RawInput { screen_rect: Some(Rect::from_min_size(Pos2::ZERO, vec2(1200.0, 800.0))), ..Default::default() };
+    for _ in 0..3 {
+        let mut output = ctx.run_ui(raw(), |ui| {
+            eframe::App::logic(&mut app, ui.ctx(), &mut frame);
+            app.draw(ui, &frame);
+        });
+        output.textures_delta.clear();
+    }
+    let mut input = raw();
+    input.events.push(egui::Event::Ime(egui::ImeEvent::Preedit { text: "é".into(), active_range_chars: None }));
+    let mut output = ctx.run_ui(input, |ui| {
+        eframe::App::logic(&mut app, ui.ctx(), &mut frame);
+        app.draw(ui, &frame);
+    });
+    output.textures_delta.clear();
+    assert!(output.platform_output.ime.is_some());
+    app.session.execute("text.setSelection", json!({"caret": 1})).unwrap();
+    let selection = app.session.state.text_edit.clone();
+    let mut passes = 0;
+    let mut discarded = None;
+    let mut output = ctx.run_ui(raw(), |ui| {
+        passes += 1;
+        if passes > 1 {
+            app.ui.start_screen = true;
+        }
+        eframe::App::logic(&mut app, ui.ctx(), &mut frame);
+        app.draw(ui, &frame);
+        if passes == 1 {
+            assert!(ui.ctx().output(|output| output.ime.is_some()));
+            discarded = read_reset(ui.ctx()).and_then(|guard| guard.request);
+            ui.ctx().request_discard("custom IME descriptor discarded before Home");
+        }
+    });
+    output.textures_delta.clear();
+    assert!(passes >= 2);
+    let first = discarded.expect("the actual discarded custom pass requested a fence");
+    assert!(output.platform_output.ime.is_none());
+    assert!(read_reset(&ctx).unwrap().suspended);
+    assert!(read_reset(&ctx).unwrap().request.is_none());
+    assert_eq!(app.session.state.text_edit, selection, "Home did not move the model caret");
+    app.ui.start_screen = false;
+    let mut output = ctx.run_ui(raw(), |ui| {
+        eframe::App::logic(&mut app, ui.ctx(), &mut frame);
+        app.draw(ui, &frame);
+    });
+    output.textures_delta.clear();
+    let second = output.platform_output.ime.unwrap().reset_request.expect("same caret reactivation publishes a new real ID");
+    assert_ne!(first, second);
+    let mut output = ctx.run_ui(raw(), |ui| {
+        eframe::App::logic(&mut app, ui.ctx(), &mut frame);
+        app.draw(ui, &frame);
+    });
+    output.textures_delta.clear();
+    assert!(output.platform_output.ime.unwrap().reset_request.is_none());
+    let mut input = raw();
+    input.events.extend([
+        egui::Event::ImeResetCompleted { request_id: first },
+        egui::Event::Ime(egui::ImeEvent::Commit("X".into())),
+        egui::Event::ImeResetCompleted { request_id: second },
+        egui::Event::Ime(egui::ImeEvent::Preedit { text: "が".into(), active_range_chars: None }),
+        egui::Event::Ime(egui::ImeEvent::Commit("が".into())),
+    ]);
+    let mut output = ctx.run_ui(input, |ui| {
+        eframe::App::logic(&mut app, ui.ctx(), &mut frame);
+        app.draw(ui, &frame);
+    });
+    output.textures_delta.clear();
+    assert_eq!(doc_text(&app, lid), "aがbcd");
+}
+
+#[test]
+fn viewport_fences_and_duplicate_completion_keep_their_exact_lifetime() {
+    let (mut app, lid) = editor("abcd", 4, 4);
+    let mut root = ImePass::new(egui::ViewportId::ROOT);
+    let mut detached = ImePass::new(egui::ViewportId::from_hash_of("effect-ime-detached"));
+    let preview = || egui::Event::Ime(egui::ImeEvent::Preedit { text: "é".into(), active_range_chars: None });
+    root.frame(&mut app, vec![preview()], true, false);
+    detached.frame(&mut app, vec![preview()], true, false);
+    app.session.execute("text.setSelection", json!({"caret": 1})).unwrap();
+    let first = root.frame(&mut app, vec![], true, false).unwrap().reset_request.unwrap();
+    let second = detached.frame(&mut app, vec![], true, false).unwrap().reset_request.unwrap();
+    assert_ne!(first, second);
+    detached.frame(&mut app, vec![egui::Event::ImeResetCompleted { request_id: first }, egui::Event::Ime(egui::ImeEvent::Commit("X".into()))], true, false);
+    assert_eq!(doc_text(&app, lid), "abcd");
+    let pending = detached.ctx.data(|data| data.get_temp::<ResetGuard>(reset_id(detached.viewport))).unwrap().request;
+    assert_eq!(pending, Some(second), "a root marker cannot release the detached viewport's full ID");
+    let output = detached
+        .frame(
+            &mut app,
+            vec![
+                egui::Event::ImeResetCompleted { request_id: second },
+                preview(),
+                egui::Event::ImeResetCompleted { request_id: second },
+                egui::Event::Ime(egui::ImeEvent::Commit("が".into())),
+            ],
+            true,
+            false,
+        )
+        .unwrap();
+    assert_eq!(doc_text(&app, lid), "aがbcd");
+    assert!(output.reset_request.is_none(), "a duplicate control cannot reconstruct the cleared guard");
+    // An actual context-generation change at unchanged selection still supersedes a wait.
+    root.frame(&mut app, vec![], true, false);
+    let replaced = root.frame(&mut app, vec![], false, false);
+    assert!(replaced.is_none());
+    let replacement = root.frame(&mut app, vec![], true, false).unwrap().reset_request.unwrap();
+    assert_ne!(first, replacement);
+}
+
+#[test]
+fn ime_descriptor_sends_committed_text_and_preserves_a_reversed_selection() {
+    let (mut app, _) = editor("café😀", 2, 5);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    let first = pass.frame(&mut app, vec![], true, false).expect("the focused editor owns IME");
+    assert_eq!(first.owner, ime_target(&app).expect("an edit target").owner);
+    assert!(first.context_generation > 0);
+    assert_eq!(ime_text(&first), ("café😀", 9, 2), "UTF-8 bytes, with the caret's direction kept");
+    assert_eq!(first.change_cause, egui::ImeChangeCause::Other, "starting a context is application origin");
+    assert_eq!((first.rect, first.cursor_rect), (pass.rect, pass.rect), "the real caret geometry");
+
+    let again = pass.frame(&mut app, vec![], true, false).expect("still editing");
+    assert_eq!(again.context_generation, first.context_generation, "an unchanged pass keeps the context");
+    assert_eq!(again.surrounding_text, first.surrounding_text);
+}
+
+#[test]
+fn accepted_ime_commit_is_input_method_and_ordinary_typing_is_other() {
+    let (mut app, lid) = editor("ab", 2, 2);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    let first = pass.frame(&mut app, vec![], true, false).expect("editing");
+    let generation = first.context_generation;
+
+    let commit = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("日".into()))], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), "ab日");
+    assert_eq!(ime_text(&commit), ("ab日", 5, 5));
+    assert_eq!(commit.change_cause, egui::ImeChangeCause::InputMethod, "only the accepted commit earns it");
+    assert_eq!(commit.context_generation, generation, "an ordinary text change is not a new context");
+
+    let typed = pass.frame(&mut app, vec![egui::Event::Text("x".into())], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), "ab日x");
+    assert_eq!(typed.change_cause, egui::ImeChangeCause::Other, "typing is application work");
+    assert_eq!(typed.context_generation, generation);
+}
+
+#[test]
+fn ime_delete_and_commit_chain_is_input_method_with_a_reversed_selection() {
+    let (mut app, lid) = editor("abcdef", 4, 1);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    pass.frame(&mut app, vec![], true, false).expect("editing");
+
+    let deleted = pass
+        .frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::DeleteSurrounding { before_chars: 1, after_chars: 1 })], true, false)
+        .expect("still editing");
+    assert_eq!(doc_text(&app, lid), "bcdf", "one character goes before and one after the selection");
+    assert_eq!(ime_text(&deleted), ("bcdf", 0, 3), "the selected text and its reversed direction stay");
+    assert_eq!(deleted.change_cause, egui::ImeChangeCause::InputMethod);
+
+    let committed = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("X".into()))], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), "Xf", "the commit replaces the kept selection");
+    assert_eq!(committed.change_cause, egui::ImeChangeCause::InputMethod, "the delete and commit are one accepted chain");
+    app.session.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(doc_text(&app, lid), "abcdef", "the replacement is one undo step");
+}
+
+#[test]
+fn an_application_edit_in_the_same_frame_dominates_the_ime_cause() {
+    // Application edit before the IME commit.
+    let (mut app, lid) = editor("ab", 2, 2);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    pass.frame(&mut app, vec![], true, false).expect("editing");
+    let mixed =
+        pass.frame(&mut app, vec![egui::Event::Text("x".into()), egui::Event::Ime(egui::ImeEvent::Commit("日".into()))], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), "abx日");
+    assert_eq!(mixed.change_cause, egui::ImeChangeCause::Other, "the earlier application edit dominates");
+
+    // Application edit after the IME commit.
+    let (mut app, lid) = editor("ab", 2, 2);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    pass.frame(&mut app, vec![], true, false).expect("editing");
+    let mixed =
+        pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("日".into())), egui::Event::Text("x".into())], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), "ab日x");
+    assert_eq!(mixed.change_cause, egui::ImeChangeCause::Other, "the later application edit dominates");
+}
+
+#[test]
+fn preedit_is_excluded_from_the_committed_snapshot_and_keeps_the_context() {
+    let (mut app, lid) = editor("ab", 2, 2);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    let first = pass.frame(&mut app, vec![], true, false).expect("editing");
+
+    let preview = pass
+        .frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false)
+        .expect("still editing");
+    assert_eq!(doc_text(&app, lid), "ab", "the pre-edit never enters the document");
+    assert_eq!(ime_text(&preview), ("ab", 2, 2), "only committed text is sent");
+    assert_eq!(preview.context_generation, first.context_generation, "pre-edit updates keep the composition");
+
+    let commit = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("に".into()))], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), "abに");
+    assert_eq!(commit.change_cause, egui::ImeChangeCause::InputMethod, "clearing the pre-edit and committing is IME work");
+    assert_eq!(commit.context_generation, first.context_generation);
+}
+
+#[test]
+fn empty_and_unavailable_surrounding_text_are_distinct() {
+    let (mut app, _) = editor("", 0, 0);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    let empty = pass.frame(&mut app, vec![], true, false).expect("editing");
+    assert_eq!(ime_text(&empty), ("", 0, 0), "an available-empty document is not unavailable");
+
+    let text = "a".repeat(5000);
+    let (mut app, _) = editor(&text, 0, 5000);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    let wide = pass.frame(&mut app, vec![], true, false).expect("editing");
+    assert!(matches!(wide.surrounding_text, egui::output::IMESurroundingText::Unavailable), "a selection wider than the limit is unavailable");
+    assert_eq!(wide.owner, ime_target(&app).expect("an edit target").owner, "identity survives unavailable text");
+}
+
+#[test]
+fn an_unrelated_undo_keeps_a_wide_selection_composition() {
+    // A selection wider than the IME limit reports unavailable surrounding text, whose
+    // receipt identity is a revision. That revision must follow the editor, not the whole
+    // project: undoing an unrelated opacity change used to look like an editor mutation and
+    // cancel an active composition.
+    let text = "a".repeat(5000);
+    let (mut app, lid) = editor(&text, 0, 5000);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    let first = pass.frame(&mut app, vec![], true, false).expect("editing");
+    assert!(matches!(first.surrounding_text, egui::output::IMESurroundingText::Unavailable), "the wide selection is unavailable");
+
+    let composing = pass
+        .frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false)
+        .expect("still editing");
+    assert_eq!(composing.context_generation, first.context_generation, "the pre-edit keeps the context");
+    let owner = ime_owner(&app).expect("an editor owner");
+    assert!(matches!(
+        pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))),
+        Some(ImeComposition::Active(active)) if active == owner
+    ));
+
+    app.session.execute("prop.set", json!({"layer": lid.0, "path": "transform/opacity", "value": 50})).unwrap();
+    app.session.execute("edit.undo", json!({})).unwrap();
+    let after = pass.frame(&mut app, vec![], true, false).expect("still editing");
+    assert_eq!(after.context_generation, first.context_generation, "an unrelated undo does not start a new context");
+    assert!(
+        matches!(
+            pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))),
+            Some(ImeComposition::Active(active)) if active == owner
+        ),
+        "the wide-selection composition survives an unrelated undo"
+    );
+    assert!(read_reset(&pass.ctx).is_none(), "no IME reset was requested");
+
+    // The composition is still the live one: its commit is accepted and earns the
+    // input-method cause rather than being poisoned as leftover application work.
+    let commit = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("x".into()))], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), "x", "the preserved composition commits into the wide selection");
+    assert_eq!(commit.change_cause, egui::ImeChangeCause::InputMethod);
+}
+
+#[test]
+fn a_failed_batch_with_a_transient_edit_does_not_revive_a_wide_selection_composition() {
+    // The final document equals the pre-batch one, but the intermediate insert/delete was a
+    // real document change. Its IME revision must stay the high-water mark; otherwise the
+    // active wide-selection composition would look current and accept its old commit.
+    let text = "a".repeat(5000);
+    let (mut app, lid) = editor(&text, 0, 5000);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    pass.frame(&mut app, vec![], true, false).expect("editing");
+    pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false).expect("still editing");
+    let owner = ime_owner(&app).expect("an editor owner");
+    assert!(matches!(
+        pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))),
+        Some(ImeComposition::Active(active)) if active == owner
+    ));
+
+    let r = app.session.execute(
+        "engine.batch",
+        json!({"atomic": true, "steps": [
+            {"command": "text.insert", "params": {"text": "x", "range": [5000, 5000]}},
+            {"command": "text.delete", "params": {}},
+            {"command": "no.suchCommand", "params": {}}
+        ]}),
+    );
+    assert!(r.is_err());
+    assert_eq!(doc_text(&app, lid), text, "the batch restored the final document");
+
+    pass.frame(&mut app, vec![], true, false).expect("still editing");
+    assert!(read_reset(&pass.ctx).is_some(), "the advanced revision retires the old IME context");
+    assert!(
+        matches!(pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))), Some(ImeComposition::Stale)),
+        "the failed batch's transient edit leaves the old composition stale"
+    );
+    let stale = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("z".into()))], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), text, "the stale composition cannot commit into the restored document");
+    assert_ne!(stale.change_cause, egui::ImeChangeCause::InputMethod, "a rejected commit earns no IME receipt");
+}
+
+#[test]
+fn a_wide_content_change_invalidates_the_active_composition() {
+    let text = "a".repeat(5000);
+    let (mut app, lid) = editor(&text, 0, 5000);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    pass.frame(&mut app, vec![], true, false).expect("editing");
+    pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false).expect("still editing");
+
+    let replaced = "b".repeat(5000);
+    app.session.execute("layer.setText", json!({"layer": lid.0, "text": replaced})).unwrap();
+    let after = pass.frame(&mut app, vec![], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), replaced);
+    assert!(after.should_interrupt_composition, "replacing the wide document starts a new IME context");
+    assert!(
+        matches!(pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))), Some(ImeComposition::Stale)),
+        "the old composition is stale after the content change"
+    );
+    pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("z".into()))], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), replaced, "a delayed commit from the old document is rejected");
+}
+
+#[test]
+fn a_wide_selection_change_invalidates_the_active_composition() {
+    let text = "a".repeat(5000);
+    let (mut app, lid) = editor(&text, 0, 5000);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    pass.frame(&mut app, vec![], true, false).expect("editing");
+    pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false).expect("still editing");
+
+    // Still wider than the IME window limit, so this exercises the unavailable-text
+    // selection identity rather than merely making the surrounding text available.
+    app.session.execute("text.setSelection", json!({"start": 0, "end": 4500})).unwrap();
+    pass.frame(&mut app, vec![], true, false).expect("still editing");
+    assert!(read_reset(&pass.ctx).is_some(), "an application selection change retires the composition");
+    assert!(
+        matches!(pass.ctx.data(|d| d.get_temp::<ImeComposition>(ime_composition_id(pass.viewport))), Some(ImeComposition::Stale)),
+        "the old composition cannot follow the selection"
+    );
+    pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("z".into()))], true, false).expect("still editing");
+    assert_eq!(doc_text(&app, lid), text, "the stale composition cannot mutate the wide selection");
+}
+
+#[test]
+fn replaced_edit_session_and_hidden_passes_start_a_new_context() {
+    let (mut app, _) = editor("text", 4, 4);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    let before = pass.frame(&mut app, vec![], true, false).expect("editing");
+    if let Some(edit) = app.session.state.text_edit.as_mut() {
+        edit.session = edit.session.wrapping_add(1);
+    }
+    let replaced = pass.frame(&mut app, vec![], true, false).expect("editing");
+    assert!(replaced.context_generation > before.context_generation, "a recreated target does not inherit the old context");
+    assert_eq!(replaced.change_cause, egui::ImeChangeCause::Other);
+    assert!(replaced.should_interrupt_composition, "a new replacement epoch cancels the platform composition");
+
+    let (mut app, _) = editor("abc", 3, 3);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    let visible = pass.frame(&mut app, vec![], true, false).expect("editing");
+    assert!(pass.frame(&mut app, vec![], false, false).is_none(), "a hidden editor reports no IME owner");
+    let back = pass.frame(&mut app, vec![], true, false).expect("editing again");
+    assert!(back.context_generation > visible.context_generation, "reappearing starts exactly one new context");
+}
+
+#[test]
+fn preedit_from_a_replaced_target_cannot_commit_into_the_new_session() {
+    let (mut app, first) = editor("A", 1, 1);
+    let second = app.session.execute("layer.newText", json!({"text": "B"})).unwrap()["layer"].as_u64().unwrap();
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "か".into(), active_range_chars: None })], true, false)
+        .expect("editing the first layer");
+
+    app.session.execute("text.edit", json!({"layer": second, "caret": 1})).unwrap();
+    let switched = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("日".into()))], true, false).expect("editing the second layer");
+    assert_eq!(doc_text(&app, LayerId(second)), "B", "a delayed commit from the old composition is ignored");
+    assert_eq!(doc_text(&app, first), "A", "the old layer is not changed either");
+    assert_eq!(switched.owner, ime_target(&app).expect("second target").owner);
+    assert!(switched.should_interrupt_composition, "the target switch interrupts the old composition");
+}
+
+#[test]
+fn hidden_pass_clears_this_viewports_preedit_preview() {
+    let (mut app, _) = editor("ab", 2, 2);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Preedit { text: "に".into(), active_range_chars: None })], true, false).expect("editing");
+    assert!(pass.ctx.data(|d| d.get_temp::<Preedit>(ime_preedit_id(pass.viewport))).is_some());
+    assert!(pass.frame(&mut app, vec![], false, false).is_none());
+    assert!(pass.ctx.data(|d| d.get_temp::<Preedit>(ime_preedit_id(pass.viewport))).is_none(), "a pass without the overlay clears this viewport's preview");
+}
+
+#[test]
+fn a_discarded_pass_keeps_the_frame_cause_and_the_context() {
+    let (mut app, lid) = editor("ab", 2, 2);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    let first = pass.frame(&mut app, vec![], true, false).expect("editing");
+    let committed = pass.frame(&mut app, vec![egui::Event::Ime(egui::ImeEvent::Commit("日".into()))], true, true).expect("the final pass of the frame");
+    assert_eq!(doc_text(&app, lid), "ab日", "the discarded pass did not replay the event");
+    assert_eq!(committed.change_cause, egui::ImeChangeCause::InputMethod, "an unchanged later pass keeps the frame's cause");
+    assert_eq!(committed.context_generation, first.context_generation, "both passes are one context");
+}
+
+#[test]
+fn two_viewports_keep_independent_ime_contexts() {
+    let (mut app, _) = editor("ab", 2, 2);
+    let mut first = ImePass::new(egui::ViewportId::ROOT);
+    let mut second = ImePass::new(egui::ViewportId::from_hash_of("ime-test-second-viewport"));
+    let one = first.frame(&mut app, vec![], true, false).expect("editing in the first viewport");
+    let two = second.frame(&mut app, vec![], true, false).expect("editing in the second viewport");
+    assert_ne!(one.context_generation, two.context_generation, "each viewport has its own generation");
+    let again = first.frame(&mut app, vec![], true, false).expect("editing in the first viewport");
+    assert_eq!(again.context_generation, one.context_generation, "the second viewport did not disturb the first");
+}
+
+/// Draw one real `EffectcraftApp::draw` pass, so `draw`'s all-exit finalizer runs.
+fn draw_app_pass(app: &mut EffectcraftApp, ctx: &egui::Context, frame: &eframe::Frame, events: Vec<egui::Event>) -> egui::FullOutput {
+    let raw = egui::RawInput { screen_rect: Some(egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(1200.0, 800.0))), events, ..Default::default() };
+    let mut out = ctx.run_ui(raw, |ui| app.draw(ui, frame));
+    out.textures_delta.clear();
+    out
+}
+
+/// One headless pass with the custom viewer and a real stock `TextEdit` side by side.
+///
+/// The first call focuses the custom editor before `keyboard` (the outside press arrives
+/// there). The second call leaves the stock field's focus alone, so the stock descriptor
+/// is published by the same `output.ime` writer that an unrelated field would use.
+fn stock_pass(
+    pass: &mut ImePass,
+    app: &mut EffectcraftApp,
+    events: Vec<egui::Event>,
+    stock: &mut String,
+    custom_focus: bool,
+) -> Option<egui::output::IMEOutput> {
+    let ctx = pass.ctx.clone();
+    let viewport = pass.viewport;
+    let custom = egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(160.0, 90.0));
+    let stock_rect = egui::Rect::from_min_size(egui::pos2(180.0, 30.0), egui::vec2(120.0, 24.0));
+    let stock_id = egui::Id::unique("effectcraft-ime-test-stock");
+    let mut viewports = egui::ViewportIdMap::default();
+    viewports.insert(viewport, egui::ViewportInfo::default());
+    let raw = egui::RawInput { viewport_id: viewport, viewports, screen_rect: Some(pass.rect), events, ..Default::default() };
+    let mut out = ctx.run_ui(raw, |ui| {
+        begin_ui(ui.ctx());
+        if custom_focus {
+            ui.interact(custom, focus_id(), egui::Sense::focusable_noninteractive());
+            ui.memory_mut(|m| m.request_focus(focus_id()));
+            sync_ime_target(ui, app);
+            keyboard(app, ui, custom);
+        } else {
+            // The stock field holds focus after the outside press; keep that ownership while
+            // the second pass publishes the actual stock descriptor.
+            ui.memory_mut(|m| m.request_focus(stock_id));
+        }
+        let _ = ui.put(stock_rect, egui::TextEdit::singleline(stock).id(stock_id));
+        finish_ime(app, ui);
+    });
+    out.textures_delta.clear();
+    out.platform_output.ime
+}
+
+#[test]
+fn outside_pointer_to_stock_allocates_no_new_request_and_defers_the_replacement() {
+    let (mut app, lid) = editor("abcd", 4, 4);
+    let mut pass = ImePass::new(egui::ViewportId::ROOT);
+    let preview = || egui::Event::Ime(egui::ImeEvent::Preedit { text: "é".into(), active_range_chars: None });
+    pass.frame(&mut app, vec![preview()], true, false).expect("the custom editor starts a composition");
+    app.session.execute("text.setSelection", json!({"caret": 1})).unwrap();
+    let first = pass.frame(&mut app, vec![], true, false).expect("the caret change publishes a request").reset_request.expect("the real request ID");
+    // Complete the first interruption, then start a fresh composition with no waiting guard.
+    pass.frame(&mut app, vec![egui::Event::ImeResetCompleted { request_id: first }], true, false);
+    let active = pass.frame(&mut app, vec![preview()], true, false).expect("a fresh composition");
+    assert!(active.reset_request.is_none(), "a fresh composition does not wait on an old request");
+    assert_eq!(doc_text(&app, lid), "abcd");
+
+    // The press outside the viewer also gives the stock field focus. It must not allocate a
+    // new request: core would attach that request to the stock descriptor next pass.
+    let outside = egui::pos2(240.0, 42.0);
+    let mut stock = String::new();
+    stock_pass(
+        &mut pass,
+        &mut app,
+        vec![
+            egui::Event::PointerMoved(outside),
+            egui::Event::PointerButton { pos: outside, button: egui::PointerButton::Primary, pressed: true, modifiers: egui::Modifiers::NONE },
+        ],
+        &mut stock,
+        true,
+    );
+    let guard = pass.ctx.data(|d| d.get_temp::<ResetGuard>(reset_id(pass.viewport))).expect("the custom guard is retired locally");
+    assert!(guard.suspended && guard.request.is_none(), "the outside press retires the old request without allocating another");
+    let stock_ime = stock_pass(&mut pass, &mut app, vec![], &mut stock, false).expect("the actual stock field owns IME");
+    assert_ne!(stock_ime.owner, ime_target(&app).expect("the custom target is still live").owner);
+    assert!(stock_ime.reset_request.is_none(), "a new outside-press request would surface on the stock output");
+    assert_eq!(doc_text(&app, lid), "abcd");
+
+    // Returning to a confirmed eligible custom output allocates the one replacement.
+    let replacement = pass.frame(&mut app, vec![], true, false).expect("the custom editor owns IME again").reset_request.expect("the deferred replacement");
+    assert_ne!(first, replacement);
+    assert!(pass.frame(&mut app, vec![], true, false).expect("still editing").reset_request.is_none(), "the replacement is one-shot");
+}
+
+#[test]
+fn fonts_and_device_loss_all_exit_finalizers_suspend_without_allocating() {
+    let (mut app, _lid) = editor("abcd", 1, 1);
+    app.ui.start_screen = false;
+    app.ui.tool = Tool::Type;
+    app.ui.focused = PanelKind::Composition;
+    app.show_panel(PanelKind::Composition);
+    let ctx = egui::Context::default();
+    install_hooks(&ctx);
+    let frame = eframe::Frame::_new_kittest();
+    let preview = || egui::Event::Ime(egui::ImeEvent::Preedit { text: "é".into(), active_range_chars: None });
+    // The first pass installs fonts and the next draws the real viewer.
+    for _ in 0..3 {
+        draw_app_pass(&mut app, &ctx, &frame, vec![]);
+    }
+    draw_app_pass(&mut app, &ctx, &frame, vec![preview()]);
+    app.session.execute("text.setSelection", json!({"caret": 2})).unwrap();
+    let first = draw_app_pass(&mut app, &ctx, &frame, vec![])
+        .platform_output
+        .ime
+        .expect("the normal pass publishes the custom descriptor")
+        .reset_request
+        .expect("one request for the caret interruption");
+
+    // A real font-install pass draws nothing, but `draw` still reaches the finalizer.
+    app.styled = false;
+    let fonts = draw_app_pass(&mut app, &ctx, &frame, vec![]);
+    assert!(!app.is_ready(), "the font-install pass cannot draw");
+    assert!(fonts.platform_output.ime.is_none(), "no custom descriptor is published");
+    let guard = ctx.data(|d| d.get_temp::<ResetGuard>(reset_id(egui::ViewportId::ROOT))).expect("the waiting guard");
+    assert!(guard.suspended && guard.request.is_none(), "the all-exit finalizer retired it without allocating");
+    let second = draw_app_pass(&mut app, &ctx, &frame, vec![])
+        .platform_output
+        .ime
+        .expect("returning to a drawing pass publishes the custom descriptor")
+        .reset_request
+        .expect("the deferred request");
+    assert_ne!(first, second);
+
+    // The device-loss early return is the other all-exit path. Preset the close bookkeeping
+    // so this test does not autosave; the pass must still retire the waiting guard.
+    app.gpu_failure_applied = Some(true);
+    app.device_lost_close = Some(true);
+    let lost = draw_app_pass(&mut app, &ctx, &frame, vec![]);
+    assert!(lost.platform_output.ime.is_none(), "a lost renderer publishes no descriptor");
+    let guard = ctx.data(|d| d.get_temp::<ResetGuard>(reset_id(egui::ViewportId::ROOT))).expect("the waiting guard");
+    assert!(guard.suspended && guard.request.is_none(), "the device-loss finalizer retired it without allocating");
+    app.gpu_failure_applied = None;
+    let third = draw_app_pass(&mut app, &ctx, &frame, vec![])
+        .platform_output
+        .ime
+        .expect("a drawing pass publishes the custom descriptor again")
+        .reset_request
+        .expect("the deferred request is one-shot");
+    assert_ne!(third, second);
+}
+
+#[test]
+fn ime_delete_without_a_session_or_with_an_empty_range_does_nothing() {
+    let (mut app, lid) = editor("abc", 1, 1);
+    feed(&mut app, vec![egui::Event::Ime(egui::ImeEvent::DeleteSurroundingBytes { before_bytes: 0, after_bytes: 0 })]);
+    assert_eq!(doc_text(&app, lid), "abc");
+    app.session.state.text_edit = None;
+    feed(&mut app, vec![egui::Event::Ime(egui::ImeEvent::DeleteSurroundingBytes { before_bytes: 2, after_bytes: 0 })]);
+    assert_eq!(doc_text(&app, lid), "abc");
+}
diff --git a/crates/ui-egui/src/panels/viewer_tools.rs b/crates/ui-egui/src/panels/viewer_tools.rs
index 238a48c37..f86a7bfee 100644
--- a/crates/ui-egui/src/panels/viewer_tools.rs
+++ b/crates/ui-egui/src/panels/viewer_tools.rs
@@ -48,20 +48,21 @@ pub(crate) fn snap(
     sources: &[[f64; 2]],
     mods: egui::Modifiers,
 ) -> [f64; 2] {
-    snap_with(app, ctx, ectx, map, exclude, sources, mods, &[])
+    snap_with(app, ctx, ectx, map, &SnapQuery { exclude, sources, mods, extra: &[] })
 }
 
-/// [`snap`] with `extra` layer targets (the Pan Behind layer's own box).
-pub(crate) fn snap_with(
-    app: &EffectcraftApp,
-    ctx: &egui::Context,
-    ectx: &EvalCtx,
-    map: &ViewerMap,
-    exclude: &[LayerId],
-    sources: &[[f64; 2]],
-    mods: egui::Modifiers,
-    extra: &[vw::SnapTarget],
-) -> [f64; 2] {
+/// What [`snap_with`] snaps: the dragged features and the layers to ignore, plus `extra` layer
+/// targets (the Pan Behind layer's own box).
+pub(crate) struct SnapQuery<'a> {
+    pub exclude: &'a [LayerId],
+    pub sources: &'a [[f64; 2]],
+    pub mods: egui::Modifiers,
+    pub extra: &'a [vw::SnapTarget],
+}
+
+/// [`snap`] with extra layer targets.
+pub(crate) fn snap_with(app: &EffectcraftApp, ctx: &egui::Context, ectx: &EvalCtx, map: &ViewerMap, q: &SnapQuery) -> [f64; 2] {
+    let SnapQuery { exclude, sources, mods, extra } = *q;
     let layers = snapping_on(app, mods);
     let v = &app.ui.viewer;
     let guides = v.snap_guides && v.guides;
@@ -620,6 +621,26 @@ pub(crate) fn bottom_bar(app: &mut EffectcraftApp, ui: &mut egui::Ui, bar: Rect,
     });
 }
 
+/// The exposure drag field (stops) at `er`; a change runs `view.exposure`.
+fn exposure_field(app: &mut EffectcraftApp, ui: &mut egui::Ui, er: Rect, stops: f64) {
+    let mut ev = stops;
+    let resp = ui.put(
+        er,
+        crate::widgets::drag_value(
+            egui::DragValue::new(&mut ev)
+                .speed(0.05)
+                .range(-40.0..=40.0)
+                .fixed_decimals(1)
+                .custom_formatter(|v, _| if v == 0.0 { "0.0".into() } else { format!("{v:+.1}") }),
+        ),
+    );
+    let resp = resp.on_hover_text(crate::i18n::tr("Adjust Exposure (stops)"));
+    app.auto.add_response("viewer.exposure", &resp, "Adjust Exposure");
+    if resp.changed() {
+        let _ = app.session.execute("view.exposure", json!({"stops": ev}));
+    }
+}
+
 /// Lay out the viewer's control row from `bar.min.x`: magnification, resolution, transparency, mask, ROI, grid/guide,
 /// channel/colour management, exposure, snapshot, fast previews, 3D renderer/view and Extended Viewer, timecode and render-time
 /// indicators, running commands or toggling viewer UI state. Returns the width the row
@@ -743,22 +764,7 @@ fn bottom_bar_contents(app: &mut EffectcraftApp, ui: &mut egui::Ui, bar: Rect, z
         let _ = app.session.execute("view.resetExposure", json!({}));
     }
     let er = Rect::from_min_size(pos2(x, cy - 10.0), vec2(42.0, 20.0));
-    let mut ev = vo.exposure as f64;
-    let resp = ui.put(
-        er,
-        crate::widgets::drag_value(
-            egui::DragValue::new(&mut ev)
-                .speed(0.05)
-                .range(-40.0..=40.0)
-                .fixed_decimals(1)
-                .custom_formatter(|v, _| if v == 0.0 { "0.0".into() } else { format!("{v:+.1}") }),
-        ),
-    );
-    let resp = resp.on_hover_text(crate::i18n::tr("Adjust Exposure (stops)"));
-    app.auto.add_response("viewer.exposure", &resp, "Adjust Exposure");
-    if resp.changed() {
-        let _ = app.session.execute("view.exposure", json!({"stops": ev}));
-    }
+    exposure_field(app, ui, er, vo.exposure as f64);
     x = er.max.x + 4.0;
     // Snapshots.
     if tog(ui, &mut app.auto, &mut x, Icon::Snapshot, false, "snapshot", "Take Snapshot").0 {
diff --git a/crates/ui-egui/src/pointer_wrap.rs b/crates/ui-egui/src/pointer_wrap.rs
index 10feae0c8..53748bd7e 100644
--- a/crates/ui-egui/src/pointer_wrap.rs
+++ b/crates/ui-egui/src/pointer_wrap.rs
@@ -177,356 +177,4 @@ pub(crate) fn finish_native(ctx: &Context, frame: &eframe::Frame) {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use egui::{Event, Id, Modifiers, PointerButton, pos2, vec2};
-
-    struct Scrub {
-        ctx: Context,
-        value: f64,
-        bounds: Rect,
-        time: f64,
-        accept_warp: bool,
-        warps: Vec<Pos2>,
-        standard: bool,
-        ordinary: bool,
-        angle: bool,
-        angle_rects: Option<(Rect, Rect)>,
-        modifiers: Modifiers,
-        injected: bool,
-    }
-
-    impl Scrub {
-        fn new() -> Self {
-            Self {
-                ctx: Context::default(),
-                value: 0.0,
-                bounds: Rect::from_min_size(Pos2::ZERO, vec2(800.0, 600.0)),
-                time: 0.0,
-                accept_warp: true,
-                warps: Vec::new(),
-                standard: false,
-                ordinary: false,
-                angle: false,
-                angle_rects: None,
-                modifiers: Modifiers::NONE,
-                injected: false,
-            }
-        }
-
-        fn frame(&mut self, events: Vec<Event>, focused: bool) {
-            self.time += 0.02;
-            let mut raw = RawInput {
-                screen_rect: Some(Rect::from_min_size(Pos2::ZERO, vec2(800.0, 600.0))),
-                time: Some(self.time),
-                events,
-                focused,
-                ..Default::default()
-            };
-            raw.events.push(Event::ModifiersChanged(self.modifiers));
-            prepare_input(&self.ctx, &mut raw, self.injected);
-            let mut out = self.ctx.run_ui(raw, |ui| {
-                if self.standard {
-                    ui.put(
-                        Rect::from_min_size(pos2(100.0, 100.0), vec2(60.0, 20.0)),
-                        crate::widgets::drag_value(egui::DragValue::new(&mut self.value).speed(1.0).max_decimals(3)),
-                    );
-                } else if self.ordinary {
-                    ui.interact(Rect::from_min_size(pos2(100.0, 100.0), vec2(60.0, 20.0)), Id::unique("ordinary"), egui::Sense::drag());
-                } else if self.angle {
-                    let (rr, dr, value) = crate::panels::fx_widgets::angle_field(
-                        ui,
-                        pos2(100.0, 100.0),
-                        Id::unique("scrub"),
-                        self.value,
-                        1,
-                        &crate::theme::Tokens::for_kind(crate::theme::ThemeKind::Dark),
-                    );
-                    self.angle_rects = Some((rr, dr));
-                    if let Some(v) = value {
-                        self.value = v;
-                    }
-                } else {
-                    let (_, value, _) = crate::widgets::hot_number_at(
-                        ui,
-                        pos2(100.0, 100.0),
-                        Id::unique("scrub"),
-                        self.value,
-                        1.0,
-                        (-1e9, 1e9),
-                        1,
-                        "",
-                        &crate::theme::Tokens::for_kind(crate::theme::ThemeKind::Dark),
-                    );
-                    if let Some(v) = value {
-                        self.value = v;
-                    }
-                }
-                finish_frame(ui.ctx(), self.bounds, |p| {
-                    self.warps.push(p);
-                    self.accept_warp.then_some(p)
-                });
-            });
-            out.textures_delta.clear();
-        }
-
-        fn move_to(&mut self, p: Pos2) {
-            self.frame(vec![Event::PointerMoved(p)], true);
-        }
-
-        fn begin(&mut self) {
-            self.frame(vec![], true);
-            let p = pos2(105.0, 108.0);
-            self.frame(
-                vec![Event::PointerMoved(p), Event::PointerButton { pos: p, button: PointerButton::Primary, pressed: true, modifiers: Modifiers::NONE }],
-                true,
-            );
-            self.move_to(p + vec2(10.0, 0.0));
-        }
-    }
-
-    #[test]
-    fn angle_degrees_continue_across_zero_and_repeated_monitor_wraps() {
-        for initial in [0.0, 359.5, -359.5, 720.0, -720.0] {
-            for direction in [-1.0, 1.0] {
-                let mut s = Scrub::new();
-                s.angle = true;
-                s.value = initial;
-                s.frame(vec![], true);
-                let p = s.angle_rects.unwrap().1.center();
-                s.frame(
-                    vec![Event::PointerMoved(p), Event::PointerButton { pos: p, button: PointerButton::Primary, pressed: true, modifiers: Modifiers::NONE }],
-                    true,
-                );
-                let mut last = p;
-                let mut expected = initial;
-                // Feed small real movements, including zero/whole-turn crossings, then
-                // the synthetic OS warp. Every real pixel contributes exactly once.
-                for step in 0..800 {
-                    let direction = if step < 400 { direction } else { -direction };
-                    let next = pos2((last.x + direction * 13.0).clamp(1.0, 799.0), last.y);
-                    expected += f64::from(next.x - last.x) * 0.5;
-                    let count = s.warps.len();
-                    s.move_to(next);
-                    assert!((s.value - expected).abs() < 1e-6, "initial={initial}, direction={direction}, actual={}, expected={expected}", s.value);
-                    last = next;
-                    if s.warps.len() > count {
-                        last = *s.warps.last().unwrap();
-                        s.move_to(last);
-                        assert!((s.value - expected).abs() < 1e-6, "the teleport must not reset the angle");
-                    }
-                }
-                assert!(s.warps.len() >= 5);
-            }
-        }
-    }
-
-    #[test]
-    fn numeric_drag_wraps_repeatedly_without_counting_the_teleport() {
-        let mut s = Scrub::new();
-        s.begin();
-        for _ in 0..5 {
-            s.move_to(pos2(799.0, 108.0));
-            let target = *s.warps.last().expect("numeric drag must wrap at the monitor edge");
-            assert!(target.x < 16.0);
-            let before = s.value;
-            s.move_to(target);
-            assert_eq!(s.value, before, "the warp itself must not change the value");
-            s.move_to(target + vec2(20.0, 0.0));
-            assert_eq!(s.value, before + 20.0);
-        }
-        assert_eq!(s.warps.len(), 5);
-        s.move_to(pos2(0.0, 108.0));
-        let target = *s.warps.last().unwrap();
-        assert!(target.x > 780.0);
-        let before = s.value;
-        s.move_to(target - vec2(3.0, 0.0));
-        assert_eq!(s.value, before - 3.0, "coalesced movement after a left-edge warp is preserved");
-    }
-
-    /// An agent's `ui.drag` over the control channel scrubs the value but never moves the user's
-    /// real cursor, even at the window's (monitor's) edge.
-    #[test]
-    fn injected_drags_never_warp_the_real_cursor() {
-        let mut s = Scrub::new();
-        s.injected = true;
-        s.begin();
-        s.move_to(pos2(799.0, 108.0));
-        assert!(s.warps.is_empty());
-    }
-
-    #[test]
-    fn normal_pointer_movement_does_not_warp() {
-        let mut s = Scrub::new();
-        s.move_to(pos2(799.0, 108.0));
-        assert!(s.warps.is_empty());
-    }
-
-    #[test]
-    fn standard_editor_wraps_at_top_bottom_and_corner_without_a_value_jump() {
-        let mut s = Scrub::new();
-        s.standard = true;
-        s.begin();
-        for edge in [pos2(200.0, 0.0), pos2(200.0, 599.0), pos2(799.0, 599.0)] {
-            s.move_to(edge);
-            let target = *s.warps.last().unwrap();
-            assert_ne!(target, edge);
-            let before = s.value;
-            s.move_to(target);
-            assert_eq!(s.value, before);
-            s.move_to(target + vec2(5.0, -5.0));
-            assert_eq!(s.value, before + 10.0);
-        }
-    }
-
-    #[test]
-    fn release_and_focus_loss_end_wrapping_and_restore_normal_hit_testing() {
-        for lose_focus in [false, true] {
-            let mut s = Scrub::new();
-            s.begin();
-            s.move_to(pos2(799.0, 108.0));
-            let target = *s.warps.last().unwrap();
-            s.move_to(target);
-            let value = s.value;
-            let events = if lose_focus {
-                vec![Event::WindowFocused(false)]
-            } else {
-                vec![Event::PointerButton { pos: target, button: PointerButton::Primary, pressed: false, modifiers: Modifiers::NONE }]
-            };
-            s.frame(events, !lose_focus);
-            s.move_to(pos2(799.0, 108.0));
-            assert_eq!(s.warps.len(), 1);
-            assert_eq!(s.value, value);
-            assert_eq!(s.ctx.input(|i| i.pointer.latest_pos()), Some(pos2(799.0, 108.0)));
-            s.begin();
-            s.move_to(pos2(799.0, 108.0));
-            assert_eq!(s.warps.len(), 2, "the next independent drag still wraps");
-        }
-    }
-
-    #[test]
-    fn object_drag_does_not_wrap_and_failed_warp_is_not_retried() {
-        let mut s = Scrub::new();
-        s.ordinary = true;
-        s.begin();
-        s.move_to(pos2(799.0, 108.0));
-        assert!(s.warps.is_empty());
-
-        let mut s = Scrub::new();
-        s.accept_warp = false;
-        s.begin();
-        s.move_to(pos2(799.0, 108.0));
-        for _ in 0..3 {
-            s.move_to(pos2(799.0, 108.0));
-        }
-        assert_eq!(s.warps.len(), 1);
-        let value = s.value;
-        s.move_to(pos2(779.0, 108.0));
-        assert_eq!(s.value, value - 20.0);
-    }
-
-    #[test]
-    fn modifiers_keep_their_sensitivity_after_wrapping() {
-        for (modifiers, multiplier) in [(Modifiers::SHIFT, 10.0), (Modifiers::COMMAND, 0.1)] {
-            let mut s = Scrub::new();
-            s.modifiers = modifiers;
-            s.begin();
-            s.move_to(pos2(799.0, 108.0));
-            let target = *s.warps.last().unwrap();
-            let value = s.value;
-            s.move_to(target + vec2(10.0, 0.0));
-            assert!((s.value - value - 10.0 * multiplier).abs() < 1e-8);
-        }
-    }
-
-    #[test]
-    fn monitor_rect_can_extend_beyond_the_app_and_have_a_negative_origin() {
-        let mut s = Scrub::new();
-        s.bounds = Rect::from_min_size(pos2(-200.0, -100.0), vec2(1200.0, 800.0));
-        s.begin();
-        s.move_to(pos2(999.0, 108.0));
-        let target = *s.warps.last().unwrap();
-        assert_eq!(target, pos2(-192.0, 108.0));
-        let value = s.value;
-        s.frame(vec![Event::PointerGone, Event::PointerMoved(target)], true);
-        assert_eq!(s.value, value);
-        s.move_to(target + vec2(10.0, 0.0));
-        assert_eq!(s.value, value + 10.0);
-    }
-
-    #[test]
-    fn real_properties_and_angle_drags_keep_each_gesture_in_one_undo_step() {
-        use crate::{EffectcraftApp, dock::PanelKind};
-        use effectcraft_engine::project::LayerId;
-        use eframe::App;
-        use serde_json::json;
-
-        for angle in [false, true] {
-            let mut session = effectcraft_host::session();
-            session.execute("comp.new", json!({"width": 32, "height": 16})).unwrap();
-            let lid = session.execute("layer.newSolid", json!({"width": 8, "height": 8})).unwrap()["layer"].as_u64().unwrap();
-            let path = if angle { "transform/rotation" } else { "transform/position" };
-            let prop = session.active_comp().unwrap().layer(LayerId(lid)).unwrap().props.prop(path).unwrap();
-            let uid = prop.uid;
-            let original = prop.value.clone();
-            let undo = session.history.undo.len();
-            let panel = PanelKind::Properties;
-            let id = if angle { format!("properties.prop.{uid}.value") } else { format!("properties.prop.{uid}.value.0") };
-            let mut app = EffectcraftApp::new(session);
-            app.show_panel(panel);
-            app.toggle_maximize(panel);
-            let ctx = Context::default();
-            let bounds = Rect::from_min_size(Pos2::ZERO, vec2(1600.0, 1000.0));
-            let mut frame = eframe::Frame::_new_kittest();
-            let mut time = 0.0;
-            let mut step = |app: &mut EffectcraftApp, events| {
-                time += 1.0 / 60.0;
-                let mut raw = RawInput { screen_rect: Some(bounds), time: Some(time), events, ..Default::default() };
-                app.raw_input_hook(&ctx, &mut raw);
-                let mut warp = None;
-                let mut out = ctx.run_ui(raw, |ui| {
-                    app.logic(ui.ctx(), &mut frame);
-                    app.ui(ui, &mut frame);
-                    finish_frame(ui.ctx(), bounds, |p| {
-                        warp = Some(p);
-                        Some(p)
-                    });
-                });
-                out.textures_delta.clear();
-                warp
-            };
-            for _ in 0..4 {
-                step(&mut app, vec![]);
-            }
-            for gesture in 1..=2 {
-                let direction = if gesture == 1 { -1.0 } else { 1.0 };
-                let r = app.auto.find(&id).unwrap().rect;
-                let p = pos2(r[0] + r[2] / 2.0, r[1] + r[3] / 2.0);
-                step(
-                    &mut app,
-                    vec![Event::PointerMoved(p), Event::PointerButton { pos: p, button: PointerButton::Primary, pressed: true, modifiers: Modifiers::NONE }],
-                );
-                step(&mut app, vec![Event::PointerMoved(p + vec2(direction * 10.0, 0.0))]);
-                let mut last = p;
-                for _ in 0..3 {
-                    let edge = if direction < 0.0 { 1.0 } else { 1599.0 };
-                    let target = step(&mut app, vec![Event::PointerMoved(pos2(edge, p.y))]).expect("real property scrubs wrap");
-                    let before = app.session.active_comp().unwrap().layer(LayerId(lid)).unwrap().props.find(uid).unwrap().value.clone();
-                    step(&mut app, vec![Event::PointerMoved(target)]);
-                    assert_eq!(app.session.active_comp().unwrap().layer(LayerId(lid)).unwrap().props.find(uid).unwrap().value, before);
-                    last = target + vec2(direction * 10.0, 0.0);
-                    step(&mut app, vec![Event::PointerMoved(last)]);
-                    if angle {
-                        let value = app.session.active_comp().unwrap().layer(LayerId(lid)).unwrap().props.find(uid).unwrap().value.as_f64();
-                        assert!((value - before.as_f64() - f64::from(direction) * 5.0).abs() < 1e-6);
-                    }
-                }
-                step(&mut app, vec![Event::PointerButton { pos: last, button: PointerButton::Primary, pressed: false, modifiers: Modifiers::NONE }]);
-                assert_eq!(app.session.history.undo.len(), undo + gesture, "each drag is one undo step: {panel:?}");
-            }
-            app.session.execute("edit.undo", json!({})).unwrap();
-            app.session.execute("edit.undo", json!({})).unwrap();
-            assert_eq!(app.session.active_comp().unwrap().layer(LayerId(lid)).unwrap().props.find(uid).unwrap().value, original);
-        }
-    }
-}
+mod tests;
diff --git a/crates/ui-egui/src/pointer_wrap/tests.rs b/crates/ui-egui/src/pointer_wrap/tests.rs
new file mode 100644
index 000000000..314f7ad3d
--- /dev/null
+++ b/crates/ui-egui/src/pointer_wrap/tests.rs
@@ -0,0 +1,343 @@
+use super::*;
+use egui::{Event, Id, Modifiers, PointerButton, pos2, vec2};
+
+struct Scrub {
+    ctx: Context,
+    value: f64,
+    bounds: Rect,
+    time: f64,
+    accept_warp: bool,
+    warps: Vec<Pos2>,
+    standard: bool,
+    ordinary: bool,
+    angle: bool,
+    angle_rects: Option<(Rect, Rect)>,
+    modifiers: Modifiers,
+    injected: bool,
+}
+
+impl Scrub {
+    fn new() -> Self {
+        Self {
+            ctx: Context::default(),
+            value: 0.0,
+            bounds: Rect::from_min_size(Pos2::ZERO, vec2(800.0, 600.0)),
+            time: 0.0,
+            accept_warp: true,
+            warps: Vec::new(),
+            standard: false,
+            ordinary: false,
+            angle: false,
+            angle_rects: None,
+            modifiers: Modifiers::NONE,
+            injected: false,
+        }
+    }
+
+    fn frame(&mut self, events: Vec<Event>, focused: bool) {
+        self.time += 0.02;
+        let mut raw =
+            RawInput { screen_rect: Some(Rect::from_min_size(Pos2::ZERO, vec2(800.0, 600.0))), time: Some(self.time), events, focused, ..Default::default() };
+        raw.events.push(Event::ModifiersChanged(self.modifiers));
+        prepare_input(&self.ctx, &mut raw, self.injected);
+        let mut out = self.ctx.run_ui(raw, |ui| {
+            if self.standard {
+                ui.put(
+                    Rect::from_min_size(pos2(100.0, 100.0), vec2(60.0, 20.0)),
+                    crate::widgets::drag_value(egui::DragValue::new(&mut self.value).speed(1.0).max_decimals(3)),
+                );
+            } else if self.ordinary {
+                ui.interact(Rect::from_min_size(pos2(100.0, 100.0), vec2(60.0, 20.0)), Id::unique("ordinary"), egui::Sense::drag());
+            } else if self.angle {
+                let (rr, dr, value) = crate::panels::fx_widgets::angle_field(
+                    ui,
+                    pos2(100.0, 100.0),
+                    Id::unique("scrub"),
+                    self.value,
+                    1,
+                    &crate::theme::Tokens::for_kind(crate::theme::ThemeKind::Dark),
+                );
+                self.angle_rects = Some((rr, dr));
+                if let Some(v) = value {
+                    self.value = v;
+                }
+            } else {
+                let (_, value, _) = crate::widgets::hot_number_at(
+                    ui,
+                    pos2(100.0, 100.0),
+                    Id::unique("scrub"),
+                    self.value,
+                    &crate::widgets::HotSpec { speed: 1.0, range: (-1e9, 1e9), decimals: 1, suffix: "" },
+                    &crate::theme::Tokens::for_kind(crate::theme::ThemeKind::Dark),
+                );
+                if let Some(v) = value {
+                    self.value = v;
+                }
+            }
+            finish_frame(ui.ctx(), self.bounds, |p| {
+                self.warps.push(p);
+                self.accept_warp.then_some(p)
+            });
+        });
+        out.textures_delta.clear();
+    }
+
+    fn move_to(&mut self, p: Pos2) {
+        self.frame(vec![Event::PointerMoved(p)], true);
+    }
+
+    fn begin(&mut self) {
+        self.frame(vec![], true);
+        let p = pos2(105.0, 108.0);
+        self.frame(
+            vec![Event::PointerMoved(p), Event::PointerButton { pos: p, button: PointerButton::Primary, pressed: true, modifiers: Modifiers::NONE }],
+            true,
+        );
+        self.move_to(p + vec2(10.0, 0.0));
+    }
+}
+
+#[test]
+fn angle_degrees_continue_across_zero_and_repeated_monitor_wraps() {
+    for initial in [0.0, 359.5, -359.5, 720.0, -720.0] {
+        for direction in [-1.0, 1.0] {
+            let mut s = Scrub::new();
+            s.angle = true;
+            s.value = initial;
+            s.frame(vec![], true);
+            let p = s.angle_rects.unwrap().1.center();
+            s.frame(
+                vec![Event::PointerMoved(p), Event::PointerButton { pos: p, button: PointerButton::Primary, pressed: true, modifiers: Modifiers::NONE }],
+                true,
+            );
+            let mut last = p;
+            let mut expected = initial;
+            // Feed small real movements, including zero/whole-turn crossings, then
+            // the synthetic OS warp. Every real pixel contributes exactly once.
+            for step in 0..800 {
+                let direction = if step < 400 { direction } else { -direction };
+                let next = pos2((last.x + direction * 13.0).clamp(1.0, 799.0), last.y);
+                expected += f64::from(next.x - last.x) * 0.5;
+                let count = s.warps.len();
+                s.move_to(next);
+                assert!((s.value - expected).abs() < 1e-6, "initial={initial}, direction={direction}, actual={}, expected={expected}", s.value);
+                last = next;
+                if s.warps.len() > count {
+                    last = *s.warps.last().unwrap();
+                    s.move_to(last);
+                    assert!((s.value - expected).abs() < 1e-6, "the teleport must not reset the angle");
+                }
+            }
+            assert!(s.warps.len() >= 5);
+        }
+    }
+}
+
+#[test]
+fn numeric_drag_wraps_repeatedly_without_counting_the_teleport() {
+    let mut s = Scrub::new();
+    s.begin();
+    for _ in 0..5 {
+        s.move_to(pos2(799.0, 108.0));
+        let target = *s.warps.last().expect("numeric drag must wrap at the monitor edge");
+        assert!(target.x < 16.0);
+        let before = s.value;
+        s.move_to(target);
+        assert_eq!(s.value, before, "the warp itself must not change the value");
+        s.move_to(target + vec2(20.0, 0.0));
+        assert_eq!(s.value, before + 20.0);
+    }
+    assert_eq!(s.warps.len(), 5);
+    s.move_to(pos2(0.0, 108.0));
+    let target = *s.warps.last().unwrap();
+    assert!(target.x > 780.0);
+    let before = s.value;
+    s.move_to(target - vec2(3.0, 0.0));
+    assert_eq!(s.value, before - 3.0, "coalesced movement after a left-edge warp is preserved");
+}
+
+/// An agent's `ui.drag` over the control channel scrubs the value but never moves the user's
+/// real cursor, even at the window's (monitor's) edge.
+#[test]
+fn injected_drags_never_warp_the_real_cursor() {
+    let mut s = Scrub::new();
+    s.injected = true;
+    s.begin();
+    s.move_to(pos2(799.0, 108.0));
+    assert!(s.warps.is_empty());
+}
+
+#[test]
+fn normal_pointer_movement_does_not_warp() {
+    let mut s = Scrub::new();
+    s.move_to(pos2(799.0, 108.0));
+    assert!(s.warps.is_empty());
+}
+
+#[test]
+fn standard_editor_wraps_at_top_bottom_and_corner_without_a_value_jump() {
+    let mut s = Scrub::new();
+    s.standard = true;
+    s.begin();
+    for edge in [pos2(200.0, 0.0), pos2(200.0, 599.0), pos2(799.0, 599.0)] {
+        s.move_to(edge);
+        let target = *s.warps.last().unwrap();
+        assert_ne!(target, edge);
+        let before = s.value;
+        s.move_to(target);
+        assert_eq!(s.value, before);
+        s.move_to(target + vec2(5.0, -5.0));
+        assert_eq!(s.value, before + 10.0);
+    }
+}
+
+#[test]
+fn release_and_focus_loss_end_wrapping_and_restore_normal_hit_testing() {
+    for lose_focus in [false, true] {
+        let mut s = Scrub::new();
+        s.begin();
+        s.move_to(pos2(799.0, 108.0));
+        let target = *s.warps.last().unwrap();
+        s.move_to(target);
+        let value = s.value;
+        let events = if lose_focus {
+            vec![Event::WindowFocused(false)]
+        } else {
+            vec![Event::PointerButton { pos: target, button: PointerButton::Primary, pressed: false, modifiers: Modifiers::NONE }]
+        };
+        s.frame(events, !lose_focus);
+        s.move_to(pos2(799.0, 108.0));
+        assert_eq!(s.warps.len(), 1);
+        assert_eq!(s.value, value);
+        assert_eq!(s.ctx.input(|i| i.pointer.latest_pos()), Some(pos2(799.0, 108.0)));
+        s.begin();
+        s.move_to(pos2(799.0, 108.0));
+        assert_eq!(s.warps.len(), 2, "the next independent drag still wraps");
+    }
+}
+
+#[test]
+fn object_drag_does_not_wrap_and_failed_warp_is_not_retried() {
+    let mut s = Scrub::new();
+    s.ordinary = true;
+    s.begin();
+    s.move_to(pos2(799.0, 108.0));
+    assert!(s.warps.is_empty());
+
+    let mut s = Scrub::new();
+    s.accept_warp = false;
+    s.begin();
+    s.move_to(pos2(799.0, 108.0));
+    for _ in 0..3 {
+        s.move_to(pos2(799.0, 108.0));
+    }
+    assert_eq!(s.warps.len(), 1);
+    let value = s.value;
+    s.move_to(pos2(779.0, 108.0));
+    assert_eq!(s.value, value - 20.0);
+}
+
+#[test]
+fn modifiers_keep_their_sensitivity_after_wrapping() {
+    for (modifiers, multiplier) in [(Modifiers::SHIFT, 10.0), (Modifiers::COMMAND, 0.1)] {
+        let mut s = Scrub::new();
+        s.modifiers = modifiers;
+        s.begin();
+        s.move_to(pos2(799.0, 108.0));
+        let target = *s.warps.last().unwrap();
+        let value = s.value;
+        s.move_to(target + vec2(10.0, 0.0));
+        assert!((s.value - value - 10.0 * multiplier).abs() < 1e-8);
+    }
+}
+
+#[test]
+fn monitor_rect_can_extend_beyond_the_app_and_have_a_negative_origin() {
+    let mut s = Scrub::new();
+    s.bounds = Rect::from_min_size(pos2(-200.0, -100.0), vec2(1200.0, 800.0));
+    s.begin();
+    s.move_to(pos2(999.0, 108.0));
+    let target = *s.warps.last().unwrap();
+    assert_eq!(target, pos2(-192.0, 108.0));
+    let value = s.value;
+    s.frame(vec![Event::PointerGone, Event::PointerMoved(target)], true);
+    assert_eq!(s.value, value);
+    s.move_to(target + vec2(10.0, 0.0));
+    assert_eq!(s.value, value + 10.0);
+}
+
+#[test]
+fn real_properties_and_angle_drags_keep_each_gesture_in_one_undo_step() {
+    use crate::{EffectcraftApp, dock::PanelKind};
+    use effectcraft_engine::project::LayerId;
+    use eframe::App;
+    use serde_json::json;
+
+    for angle in [false, true] {
+        let mut session = effectcraft_host::session();
+        session.execute("comp.new", json!({"width": 32, "height": 16})).unwrap();
+        let lid = session.execute("layer.newSolid", json!({"width": 8, "height": 8})).unwrap()["layer"].as_u64().unwrap();
+        let path = if angle { "transform/rotation" } else { "transform/position" };
+        let prop = session.active_comp().unwrap().layer(LayerId(lid)).unwrap().props.prop(path).unwrap();
+        let uid = prop.uid;
+        let original = prop.value.clone();
+        let undo = session.history.undo.len();
+        let panel = PanelKind::Properties;
+        let id = if angle { format!("properties.prop.{uid}.value") } else { format!("properties.prop.{uid}.value.0") };
+        let mut app = EffectcraftApp::new(session);
+        app.show_panel(panel);
+        app.toggle_maximize(panel);
+        let ctx = Context::default();
+        let bounds = Rect::from_min_size(Pos2::ZERO, vec2(1600.0, 1000.0));
+        let mut frame = eframe::Frame::_new_kittest();
+        let mut time = 0.0;
+        let mut step = |app: &mut EffectcraftApp, events| {
+            time += 1.0 / 60.0;
+            let mut raw = RawInput { screen_rect: Some(bounds), time: Some(time), events, ..Default::default() };
+            app.raw_input_hook(&ctx, &mut raw);
+            let mut warp = None;
+            let mut out = ctx.run_ui(raw, |ui| {
+                app.logic(ui.ctx(), &mut frame);
+                app.ui(ui, &mut frame);
+                finish_frame(ui.ctx(), bounds, |p| {
+                    warp = Some(p);
+                    Some(p)
+                });
+            });
+            out.textures_delta.clear();
+            warp
+        };
+        for _ in 0..4 {
+            step(&mut app, vec![]);
+        }
+        for gesture in 1..=2 {
+            let direction = if gesture == 1 { -1.0 } else { 1.0 };
+            let r = app.auto.find(&id).unwrap().rect;
+            let p = pos2(r[0] + r[2] / 2.0, r[1] + r[3] / 2.0);
+            step(
+                &mut app,
+                vec![Event::PointerMoved(p), Event::PointerButton { pos: p, button: PointerButton::Primary, pressed: true, modifiers: Modifiers::NONE }],
+            );
+            step(&mut app, vec![Event::PointerMoved(p + vec2(direction * 10.0, 0.0))]);
+            let mut last = p;
+            for _ in 0..3 {
+                let edge = if direction < 0.0 { 1.0 } else { 1599.0 };
+                let target = step(&mut app, vec![Event::PointerMoved(pos2(edge, p.y))]).expect("real property scrubs wrap");
+                let before = app.session.active_comp().unwrap().layer(LayerId(lid)).unwrap().props.find(uid).unwrap().value.clone();
+                step(&mut app, vec![Event::PointerMoved(target)]);
+                assert_eq!(app.session.active_comp().unwrap().layer(LayerId(lid)).unwrap().props.find(uid).unwrap().value, before);
+                last = target + vec2(direction * 10.0, 0.0);
+                step(&mut app, vec![Event::PointerMoved(last)]);
+                if angle {
+                    let value = app.session.active_comp().unwrap().layer(LayerId(lid)).unwrap().props.find(uid).unwrap().value.as_f64();
+                    assert!((value - before.as_f64() - f64::from(direction) * 5.0).abs() < 1e-6);
+                }
+            }
+            step(&mut app, vec![Event::PointerButton { pos: last, button: PointerButton::Primary, pressed: false, modifiers: Modifiers::NONE }]);
+            assert_eq!(app.session.history.undo.len(), undo + gesture, "each drag is one undo step: {panel:?}");
+        }
+        app.session.execute("edit.undo", json!({})).unwrap();
+        app.session.execute("edit.undo", json!({})).unwrap();
+        assert_eq!(app.session.active_comp().unwrap().layer(LayerId(lid)).unwrap().props.find(uid).unwrap().value, original);
+    }
+}
diff --git a/crates/ui-egui/src/state.rs b/crates/ui-egui/src/state.rs
index 88b8e7fa4..3a96d3c50 100644
--- a/crates/ui-egui/src/state.rs
+++ b/crates/ui-egui/src/state.rs
@@ -229,6 +229,7 @@ impl Tool {
     }
 }
 
+use super::*;
 /// The viewer's Resolution: each composition keeps its own in the project
 /// ([`effectcraft_engine::project::Comp::resolution`], `EffectcraftApp::viewer_res`).
 pub use effectcraft_engine::project::Resolution;
@@ -746,3 +747,48 @@ impl Default for UiState {
         }
     }
 }
+
+/// What a `ui.screenshot` captures.
+///
+/// A panel or element is an identity, not a rectangle: it is resolved again when the capture is
+/// issued, after the settle passes, so a panel that moved or resized while the UI settled is
+/// captured where it is now (never with the rectangle from request admission).
+#[derive(Clone, Debug, PartialEq)]
+pub enum ShotTarget {
+    /// The whole root surface.
+    Window,
+    /// A fixed rectangle in logical points, relative to the root surface's top-left corner.
+    Rect([f32; 4]),
+    /// One dock panel's automation rectangle (`panel.<id>`).
+    Panel(PanelKind),
+    /// One automation element id's rectangle.
+    Id(String),
+}
+
+/// The comp frames a playback pass covers (`first..=last`).
+#[derive(Clone, Copy, Debug)]
+pub(crate) struct FrameWindow {
+    pub(crate) first: i64,
+    pub(crate) last: i64,
+}
+
+/// The inputs of one playback pass: the viewer series it renders, the preview plan and
+/// position, and the frame range and clock settings its steps share. `queued` is a snapshot of
+/// the in-flight render count that each step copies. Built once in `advance_playback`.
+#[derive(Clone, Copy)]
+pub(crate) struct PlaybackPass<'a> {
+    pub(crate) ctx: &'a egui::Context,
+    pub(crate) comp: &'a effectcraft_engine::project::Comp,
+    pub(crate) cid: ItemId,
+    pub(crate) scale: f64,
+    pub(crate) now: f64,
+    pub(crate) frame_rate: effectcraft_engine::time::FrameRate,
+    pub(crate) series: FrameKey,
+    pub(crate) plan: Option<effectcraft_engine::preview::PreviewPlan>,
+    pub(crate) window: FrameWindow,
+    pub(crate) cur: i64,
+    pub(crate) video: bool,
+    pub(crate) looping: bool,
+    pub(crate) ahead: i64,
+    pub(crate) queued: usize,
+}
diff --git a/crates/ui-egui/src/widgets.rs b/crates/ui-egui/src/widgets.rs
index c870a96db..58383fe43 100644
--- a/crates/ui-egui/src/widgets.rs
+++ b/crates/ui-egui/src/widgets.rs
@@ -51,20 +51,21 @@ fn tab_stop(ui: &Ui, id: egui::Id) -> bool {
     })
 }
 
+/// How a hot-text field scrubs and prints: `speed` value units per pointer pixel, clamped to
+/// `range`, shown with `decimals` places followed by `suffix`.
+#[derive(Clone, Copy)]
+pub struct HotSpec<'a> {
+    pub speed: f64,
+    pub range: (f64, f64),
+    pub decimals: usize,
+    pub suffix: &'a str,
+}
+
 /// "Hot text": a blue number you drag horizontally to scrub, click to type. Tab / Shift+Tab
 /// while typing commits and types in the panel's next / previous one, as in After Effects.
 /// Returns (response, Some(new value) when changed, drag finished).
-pub fn hot_number_at(
-    ui: &mut Ui,
-    rect_min: egui::Pos2,
-    id: egui::Id,
-    value: f64,
-    speed: f64,
-    range: (f64, f64),
-    decimals: usize,
-    suffix: &str,
-    t: &Tokens,
-) -> (Rect, Option<f64>, bool) {
+pub fn hot_number_at(ui: &mut Ui, rect_min: egui::Pos2, id: egui::Id, value: f64, spec: &HotSpec, t: &Tokens) -> (Rect, Option<f64>, bool) {
+    let HotSpec { speed, range, decimals, suffix } = *spec;
     let editing_id = id.with("editing");
     let mut editing: Option<String> = ui.data(|d| d.get_temp(editing_id));
     if tab_stop(ui, id) && editing.is_none() {
@@ -163,7 +164,7 @@ pub fn slider_scrub_speed(ui: &ParamUi) -> f64 {
 /// `1 / speed` pixels however slowly the pointer moves (the fractions add up between frames),
 /// and a typed value is truncated. Returns (rect, Some(new value) when changed, drag finished).
 pub fn hot_int_at(ui: &mut Ui, rect_min: egui::Pos2, id: egui::Id, value: i64, speed: f64, suffix: &str, t: &Tokens) -> (Rect, Option<i64>, bool) {
-    let (rect, nv, done) = hot_number_at(ui, rect_min, id, value as f64, speed, (-1e6, 1e6), 0, suffix, t);
+    let (rect, nv, done) = hot_number_at(ui, rect_min, id, value as f64, &HotSpec { speed, range: (-1e6, 1e6), decimals: 0, suffix }, t);
     let acc_id = id.with("acc");
     let acc = ui.data(|d| d.get_temp::<f64>(acc_id)).unwrap_or(0.0) + nv.map_or(0.0, |n| n - value as f64);
     // (Ten 0.1 steps add up to just under 1.)
diff --git a/crates/ui-egui/src/workspace_state.rs b/crates/ui-egui/src/workspace_state.rs
index 92e41fde5..4807e4e40 100644
--- a/crates/ui-egui/src/workspace_state.rs
+++ b/crates/ui-egui/src/workspace_state.rs
@@ -202,350 +202,4 @@ impl WorkspaceStore {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::dock::{Floating, Layout, Node, StackEntry, WorkspaceExt as _};
-    use craft_ui::docking::Action;
-    use craft_ui::layout::{SplitAxis, SplitSize};
-    use effectcraft_engine::config::MemoryConfig;
-
-    fn minimal() -> Workspace {
-        Workspace::new(crate::dock::workspace("Minimal"))
-    }
-
-    fn tabs(panels: &[PanelKind]) -> Node<PanelKind> {
-        Node::Tabs { panels: panels.to_vec(), active: 0 }
-    }
-
-    #[test]
-    fn corrupt_future_or_unknown_workspace_keeps_defaults_and_original_file() {
-        let valid = Snapshot::capture(&UiState::default());
-        // Damaged files of the earlier version: a panel in two places, a bad split, an unknown
-        // panel, a tree deeper than craft-ui allows, a missing field.
-        let earlier = |dock: &str| {
-            format!(
-                r#"{{"version":1,"workspace":"Default","dock":{dock},"floating":[],"focused":"Composition","maximized":null,"saved_workspaces":{{}},"saved_floating":{{}}}}"#
-            )
-        };
-        let mut deep = r#"{"Tabs":{"panels":["Composition"],"active":0}}"#.to_string();
-        for _ in 0..=craft_ui::docking::MAX_DEPTH {
-            deep = format!(r#"{{"Split":{{"vertical":true,"size":{{"Ratio":0.5}},"a":{deep},"b":{{"Tabs":{{"panels":[],"active":0}}}}}}}}"#);
-        }
-        let twice =
-            r#"{"Split":{"vertical":true,"size":{"Ratio":0.5},"a":{"Tabs":{"panels":["Project"],"active":0}},"b":{"Tabs":{"panels":["Project"],"active":0}}}}"#;
-        let bad_split = r#"{"Split":{"vertical":true,"size":{"Ratio":7.0},"a":{"Tabs":{"panels":["Project"],"active":0}},"b":{"Tabs":{"panels":["Timeline"],"active":0}}}}"#;
-        for text in [
-            "{".into(),
-            "{}".into(),
-            "[1, 2]".into(),
-            serde_json::to_string(&Snapshot { version: VERSION + 1, ..valid }).unwrap(),
-            " ".repeat(MAX_BYTES + 1),
-            earlier(twice),
-            earlier(bad_split),
-            earlier(r#"{"Tabs":{"panels":["NoSuchPanel"],"active":0}}"#),
-            earlier(&deep),
-            r#"{"version":1,"workspace":"Default"}"#.into(),
-            r#"{"workspaces":{"Mine":{"Tabs":{"panels":["Composition"],"active":3}}}}"#.into(),
-        ] {
-            let config = MemoryConfig::default();
-            config.write(FILE, &text).unwrap();
-            let mut ui = UiState::default();
-            let mut store = WorkspaceStore::load(Some(&config), &mut ui);
-            assert!(store.error.is_some());
-            assert_eq!(ui.workspace, "Default");
-            assert_eq!(ui.dock, UiState::default().dock);
-            ui.focused = PanelKind::Project;
-            ui.dock = minimal();
-            assert!(!store.save(Some(&config), &ui).unwrap());
-            assert!(store.save_now(Some(&config), &ui).unwrap_err().contains("couldn't be loaded"));
-            assert_eq!(config.read(FILE).as_deref(), Some(text.as_str()));
-            assert_eq!(config.read(BACKUP), None);
-        }
-    }
-
-    /// A file written by EffectCraft 0.10 (craft-libs 5c874d51): the Default workspace with
-    /// Preview floating, Render Queue floating in its own native window, Align closed,
-    /// Effects & Presets moved into the Project group and Audio split beside the Timeline,
-    /// saved as "My Layout"; then Layer closed.
-    const V1: &str = include_str!("../tests/fixtures/workspaces-v1.json");
-
-    #[test]
-    fn version_one_file_loads_with_every_panel_in_place() {
-        let config = MemoryConfig::default();
-        config.write(FILE, V1).unwrap();
-        let mut ui = UiState::default();
-        let store = WorkspaceStore::load(Some(&config), &mut ui);
-        assert_eq!(store.error, None);
-        assert_eq!(ui.workspace, "My Layout");
-        assert_eq!(ui.focused, PanelKind::Composition);
-        use PanelKind::*;
-        let root = crate::dock::hsplit(
-            SplitSize::FixedSecond(300.0),
-            crate::dock::vsplit(
-                SplitSize::Ratio(0.56),
-                crate::dock::hsplit(SplitSize::FixedFirst(300.0), crate::dock::tabs(&[Project, EffectControls, EffectsPresets], 2), tabs(&[Composition])),
-                crate::dock::hsplit(SplitSize::Ratio(0.5), tabs(&[Timeline]), tabs(&[Audio])),
-            ),
-            tabs(&[Properties]),
-        );
-        assert_eq!(ui.dock.layout.root, Some(root));
-        let floating: Vec<_> = ui.dock.layout.floating.iter().map(|w| (w.panels().copied().collect::<Vec<_>>(), w.rect, w.native)).collect();
-        assert_eq!(
-            floating,
-            [
-                (vec![Preview], [900.0, 120.0, 300.0, 260.0], None),
-                (vec![RenderQueue], [200.0, 500.0, 520.0, 240.0], Some(crate::dock_ui::sanitized_window_rect([200.0, 500.0, 520.0, 240.0]))),
-            ]
-        );
-        // Closed panels stay closed.
-        for panel in [Align, Layer] {
-            assert!(!ui.dock.is_open(panel), "{panel:?}");
-        }
-        // The native window's place is its outer position until the main window reports its
-        // frame (here a 28-point title bar); the file is not rewritten before.
-        let id = ui.dock.layout.floating[1].id;
-        assert_eq!(ui.native_outer, [id]);
-        let mut store = store;
-        assert!(!store.save(Some(&config), &ui).unwrap());
-        let outer = egui::Rect::from_min_size(egui::pos2(10.0, 20.0), egui::vec2(1600.0, 1000.0));
-        crate::dock_ui::native_outer_to_content(&mut ui, Some(outer), Some(outer.translate(egui::vec2(0.0, 28.0))), 0.1);
-        assert_eq!(ui.dock.layout.floating[1].native, Some([200.0, 528.0, 520.0, 240.0]));
-        assert!(ui.native_outer.is_empty());
-        assert!(store.save(Some(&config), &ui).unwrap());
-        // The named workspace still has Layer, closed only after it was saved.
-        let saved = ui.saved_workspaces.get("My Layout").unwrap();
-        assert!(saved.is_docked(Layer) && saved.is_floating(Preview) && !saved.is_open(Align));
-        assert_eq!(saved.layout.floating.iter().filter_map(|w| w.native).count(), 0);
-    }
-
-    #[test]
-    fn version_one_file_is_rewritten_once_in_the_current_format_and_kept_as_a_backup() {
-        let config = MemoryConfig::default();
-        config.write(FILE, V1).unwrap();
-        let mut ui = UiState::default();
-        let mut store = WorkspaceStore::load(Some(&config), &mut ui);
-        // A backend that reports no window positions: the native place stays as it was.
-        let native = ui.dock.layout.floating[1].native;
-        crate::dock_ui::native_outer_to_content(&mut ui, None, None, 1.0);
-        assert!(!ui.native_outer.is_empty(), "waits for a report");
-        crate::dock_ui::native_outer_to_content(&mut ui, None, None, 5.0);
-        assert!(ui.native_outer.is_empty());
-        assert_eq!(ui.dock.layout.floating[1].native, native);
-        let migrated = Snapshot::capture(&ui);
-        assert!(store.has_changes(&ui), "the migrated layout is written without waiting for an edit");
-        assert!(store.save(Some(&config), &ui).unwrap());
-        assert_eq!(config.read(BACKUP).as_deref(), Some(V1));
-        let text = config.read(FILE).unwrap();
-        assert_eq!(serde_json::from_str::<serde_json::Value>(&text).unwrap()["version"], VERSION);
-        assert!(!store.has_changes(&ui));
-        let mut restored = UiState::default();
-        let reloaded = WorkspaceStore::load(Some(&config), &mut restored);
-        assert_eq!(reloaded.error, None);
-        assert!(!reloaded.has_changes(&restored));
-        assert_eq!(Snapshot::capture(&restored), migrated);
-    }
-
-    #[test]
-    fn stacked_frames_with_tabs_and_an_empty_root_migrate() {
-        let text = r#"{"version":1,"workspace":"Mine","dock":{"Tabs":{"panels":[],"active":0}},
-            "floating":[{"panels":["Project"],"active":0,"rect":[10.0,10.0,300.0,200.0]}],
-            "focused":"Project","maximized":null,
-            "saved_workspaces":{"Mine":{"Stack":{"entries":[{"panel":"Info","open":true},{"panels":["Audio","Preview"],"active":1,"open":true,"height":80.0}]}},
-                "Column":{"Stack":{"entries":[{"panel":"Align","open":false},{"panel":"Preview","open":true,"height":46.0},{"panels":["Properties","Paint"],"active":1,"open":false,"height":300.0},{"panel":"Info","open":true}]}}},
-            "saved_floating":{"Gone":[{"panels":["Align"],"active":0,"rect":[0.0,0.0,100.0,100.0]}]}}"#;
-        let config = MemoryConfig::default();
-        config.write(FILE, text).unwrap();
-        let mut ui = UiState::default();
-        let store = WorkspaceStore::load(Some(&config), &mut ui);
-        assert_eq!(store.error, None);
-        assert_eq!(ui.dock.layout.root, None);
-        assert!(ui.dock.is_floating(PanelKind::Project));
-        use PanelKind::*;
-        // Each open frame is a tab group with all its tabs; a frame's height is a fixed size
-        // (with its tab strip), and the frame without one takes the rest.
-        let column = crate::dock::vsplit(SplitSize::FixedSecond(80.0 + crate::dock::TAB_STRIP), tabs(&[Info]), crate::dock::tabs(&[Audio, Preview], 1));
-        assert_eq!(ui.saved_workspaces.get("Mine").and_then(|w| w.layout.root.clone()), Some(column));
-        // Closed frames' tabs join the open frame above them, or below at the top.
-        let column = crate::dock::vsplit(SplitSize::FixedFirst(46.0 + crate::dock::TAB_STRIP), tabs(&[Preview, Properties, Paint, Align]), tabs(&[Info]));
-        assert_eq!(ui.saved_workspaces.get("Column").and_then(|w| w.layout.root.clone()), Some(column));
-        assert_eq!(ui.saved_workspaces.len(), 2, "floating groups of no named workspace are dropped");
-    }
-
-    #[test]
-    fn explicit_save_without_a_settings_folder_is_an_error() {
-        let mut ui = UiState::default();
-        let mut store = WorkspaceStore::load(None, &mut ui);
-        ui.focused = PanelKind::Project;
-        assert!(!store.save(None, &ui).unwrap());
-        assert!(store.save_now(None, &ui).is_err());
-    }
-
-    #[test]
-    fn explicit_save_with_nothing_new_succeeds() {
-        let config = MemoryConfig::default();
-        let mut ui = UiState::default();
-        let mut store = WorkspaceStore::load(Some(&config), &mut ui);
-        ui.focused = PanelKind::Project;
-        store.save_now(Some(&config), &ui).unwrap();
-        store.save_now(Some(&config), &ui).unwrap();
-        assert!(config.read(FILE).is_some());
-    }
-
-    #[test]
-    fn invalid_tabs_split_and_deep_tree_are_rejected() {
-        let mut snapshot = Snapshot::capture(&UiState::default());
-        snapshot.dock = Workspace::new(Layout { root: Some(Node::Tabs { panels: vec![PanelKind::Project], active: usize::MAX }), floating: vec![] });
-        assert!(snapshot.validate().is_err());
-        let split = |size, first, second| Node::Split { axis: SplitAxis::Horizontal, size, first: Box::new(first), second: Box::new(second) };
-        snapshot.dock = Workspace::new(Layout {
-            root: Some(split(SplitSize::FixedFirst(f32::NAN), tabs(&[PanelKind::Project]), tabs(&[PanelKind::Timeline]))),
-            floating: vec![],
-        });
-        assert!(snapshot.validate().is_err());
-        let mut root = tabs(&[PanelKind::Composition]);
-        for _ in 0..=craft_ui::docking::MAX_DEPTH {
-            root = split(SplitSize::Ratio(0.5), root, tabs(&[]));
-        }
-        snapshot.dock = Workspace::new(Layout { root: Some(root), floating: vec![] });
-        assert!(snapshot.validate().is_err());
-        // A panel in two places.
-        snapshot.dock = Workspace::new(Layout {
-            root: Some(tabs(&[PanelKind::Project])),
-            floating: vec![Floating::single(vec![PanelKind::Project], 0, [0.0, 0.0, 200.0, 100.0])],
-        });
-        assert!(snapshot.validate().is_err());
-    }
-
-    #[test]
-    fn closing_all_docked_panels_remains_a_persistable_layout() {
-        let config = MemoryConfig::default();
-        let mut ui = UiState::default();
-        let mut store = WorkspaceStore::load(Some(&config), &mut ui);
-        for panel in ui.dock.panels() {
-            ui.dock.apply(Action::Close { panel }, crate::dock::permissions).unwrap();
-        }
-        assert!(ui.dock.layout.root.is_none());
-        assert!(store.save(Some(&config), &ui).unwrap());
-        let mut restored = UiState::default();
-        let loaded = WorkspaceStore::load(Some(&config), &mut restored);
-        assert!(loaded.error.is_none());
-        assert_eq!(restored.dock, ui.dock);
-    }
-
-    #[test]
-    fn floating_groups_and_named_snapshots_roundtrip_without_document_state() {
-        let config = MemoryConfig::default();
-        let mut ui = UiState::default();
-        let mut store = WorkspaceStore::load(Some(&config), &mut ui);
-        ui.workspace = "Floating".into();
-        ui.dock.apply(Action::Float { panel: PanelKind::Preview, rect: [50.0, 80.0, 200.0, 160.0] }, crate::dock::permissions).unwrap();
-        ui.dock.apply(Action::Close { panel: PanelKind::Align }, crate::dock::permissions).unwrap();
-        ui.saved_workspaces.insert(ui.workspace.clone(), ui.dock.clone());
-        ui.maximized = Some(PanelKind::Composition);
-        ui.project_search = "do not persist".into();
-        assert!(store.save(Some(&config), &ui).unwrap());
-        let mut restored = UiState::default();
-        WorkspaceStore::load(Some(&config), &mut restored);
-        assert_eq!(Snapshot::capture(&restored), Snapshot::capture(&ui));
-        // The closed panel's place comes back with it.
-        assert!(restored.dock.hidden.iter().any(|(p, _)| *p == PanelKind::Align));
-        assert!(restored.project_search.is_empty());
-    }
-
-    #[test]
-    fn restored_viewer_slots_do_not_reuse_ids_or_restore_document_links() {
-        let config = MemoryConfig::default();
-        let mut ui = UiState::default();
-        let mut store = WorkspaceStore::load(Some(&config), &mut ui);
-        let two = |viewer| Workspace::new(Layout { root: Some(tabs(&[PanelKind::Composition, PanelKind::Viewer(viewer)])), floating: vec![] });
-        ui.dock = two(2);
-        ui.saved_workspaces.insert("Two views".into(), two(5));
-        ui.viewers.insert(2, Some(42));
-        assert!(store.save(Some(&config), &ui).unwrap());
-        let mut app = crate::EffectcraftApp::new(effectcraft_engine::Session::default());
-        WorkspaceStore::load(Some(&config), &mut app.ui);
-        assert_eq!(app.ui.viewers.get(&2), Some(&None));
-        assert_eq!(app.ui.viewers.get(&5), Some(&None));
-        assert_eq!(crate::panels::viewers::new_viewer(&mut app), 6);
-        assert!(app.ui.dock.is_docked(PanelKind::Viewer(2)));
-    }
-
-    #[test]
-    fn invalid_viewer_ids_are_rejected_in_every_workspace_reference() {
-        for id in [0, MAX_VIEWER_ID + 1, u32::MAX] {
-            for location in 0..8 {
-                let mut snapshot = Snapshot::capture(&UiState::default());
-                let panel = PanelKind::Viewer(id);
-                let docked = Workspace::new(Layout { root: Some(tabs(&[panel])), floating: vec![] });
-                let stacked =
-                    Workspace::new(Layout { root: Some(Node::Stack { entries: vec![StackEntry { panel, open: true, height: None }] }), floating: vec![] });
-                let floating = Workspace::new(Layout {
-                    root: Some(tabs(&[PanelKind::Composition])),
-                    floating: vec![Floating::single(vec![panel], 0, [0.0, 0.0, 200.0, 100.0])],
-                });
-                let mut hidden = Workspace::new(Layout { root: Some(tabs(&[PanelKind::Composition, panel])), floating: vec![] });
-                hidden.apply(Action::Close { panel }, crate::dock::permissions).unwrap();
-                match location {
-                    0 => snapshot.focused = panel,
-                    1 => snapshot.maximized = Some(panel),
-                    2 => snapshot.dock = docked,
-                    3 => snapshot.dock = stacked,
-                    4 => snapshot.dock = floating,
-                    5 => snapshot.dock = hidden,
-                    6 => {
-                        snapshot.saved_workspaces.insert("Saved".into(), stacked);
-                    }
-                    _ => {
-                        snapshot.saved_workspaces.insert("Saved".into(), floating);
-                    }
-                }
-                assert!(snapshot.validate().is_err(), "viewer {id} at location {location} must be rejected");
-            }
-        }
-    }
-
-    #[test]
-    fn hostile_native_window_places_are_made_safe_on_load() {
-        let config = MemoryConfig::default();
-        let mut ui = UiState::default();
-        let mut store = WorkspaceStore::load(Some(&config), &mut ui);
-        ui.dock.apply(Action::Float { panel: PanelKind::Project, rect: [10.0, 10.0, 300.0, 200.0] }, crate::dock::permissions).unwrap();
-        ui.dock.apply(Action::SetNative { panel: PanelKind::Project, rect: Some([90_000.0, -90_000.0, 1.0e5, 0.5]) }, crate::dock::permissions).unwrap();
-        assert!(store.save(Some(&config), &ui).unwrap());
-        let mut restored = UiState::default();
-        WorkspaceStore::load(Some(&config), &mut restored);
-        let native = restored.dock.layout.floating.iter().find(|w| w.contains(&PanelKind::Project)).and_then(|w| w.native).unwrap();
-        assert_eq!(native, crate::dock_ui::sanitized_window_rect(native));
-        assert!(native[2] <= crate::dock_ui::PANEL_WINDOW_MAX && native[3] >= crate::dock_ui::PANEL_WINDOW_MIN[1]);
-    }
-
-    #[test]
-    fn failed_write_keeps_previous_snapshot_and_retries() {
-        struct Fails<'a>(&'a MemoryConfig);
-        impl ConfigStore for Fails<'_> {
-            fn read(&self, name: &str) -> Option<String> {
-                self.0.read(name)
-            }
-            fn write(&self, _name: &str, _data: &str) -> std::io::Result<()> {
-                Err(std::io::Error::other("synthetic full disk"))
-            }
-            fn remove(&self, _name: &str) -> std::io::Result<()> {
-                Err(std::io::Error::other("unused"))
-            }
-        }
-        let config = MemoryConfig::default();
-        let mut ui = UiState::default();
-        let mut store = WorkspaceStore::load(Some(&config), &mut ui);
-        ui.focused = PanelKind::Project;
-        assert!(store.save(Some(&config), &ui).unwrap());
-        let previous = config.read(FILE).unwrap();
-        ui.focused = PanelKind::Timeline;
-        assert!(store.save(Some(&Fails(&config)), &ui).unwrap_err().contains("synthetic full disk"));
-        assert_eq!(config.read(FILE).as_deref(), Some(previous.as_str()));
-        assert!(store.has_changes(&ui));
-        assert!(store.save(Some(&config), &ui).unwrap());
-        let mut restored = UiState::default();
-        WorkspaceStore::load(Some(&config), &mut restored);
-        assert_eq!(restored.focused, PanelKind::Timeline);
-    }
-}
+mod tests;
diff --git a/crates/ui-egui/src/workspace_state/tests.rs b/crates/ui-egui/src/workspace_state/tests.rs
new file mode 100644
index 000000000..e7b6d9aae
--- /dev/null
+++ b/crates/ui-egui/src/workspace_state/tests.rs
@@ -0,0 +1,346 @@
+use super::*;
+use crate::dock::{Floating, Layout, Node, StackEntry, WorkspaceExt as _};
+use craft_ui::docking::Action;
+use craft_ui::layout::{SplitAxis, SplitSize};
+use effectcraft_engine::config::MemoryConfig;
+
+fn minimal() -> Workspace {
+    Workspace::new(crate::dock::workspace("Minimal"))
+}
+
+fn tabs(panels: &[PanelKind]) -> Node<PanelKind> {
+    Node::Tabs { panels: panels.to_vec(), active: 0 }
+}
+
+#[test]
+fn corrupt_future_or_unknown_workspace_keeps_defaults_and_original_file() {
+    let valid = Snapshot::capture(&UiState::default());
+    // Damaged files of the earlier version: a panel in two places, a bad split, an unknown
+    // panel, a tree deeper than craft-ui allows, a missing field.
+    let earlier = |dock: &str| {
+        format!(
+            r#"{{"version":1,"workspace":"Default","dock":{dock},"floating":[],"focused":"Composition","maximized":null,"saved_workspaces":{{}},"saved_floating":{{}}}}"#
+        )
+    };
+    let mut deep = r#"{"Tabs":{"panels":["Composition"],"active":0}}"#.to_string();
+    for _ in 0..=craft_ui::docking::MAX_DEPTH {
+        deep = format!(r#"{{"Split":{{"vertical":true,"size":{{"Ratio":0.5}},"a":{deep},"b":{{"Tabs":{{"panels":[],"active":0}}}}}}}}"#);
+    }
+    let twice =
+        r#"{"Split":{"vertical":true,"size":{"Ratio":0.5},"a":{"Tabs":{"panels":["Project"],"active":0}},"b":{"Tabs":{"panels":["Project"],"active":0}}}}"#;
+    let bad_split =
+        r#"{"Split":{"vertical":true,"size":{"Ratio":7.0},"a":{"Tabs":{"panels":["Project"],"active":0}},"b":{"Tabs":{"panels":["Timeline"],"active":0}}}}"#;
+    for text in [
+        "{".into(),
+        "{}".into(),
+        "[1, 2]".into(),
+        serde_json::to_string(&Snapshot { version: VERSION + 1, ..valid }).unwrap(),
+        " ".repeat(MAX_BYTES + 1),
+        earlier(twice),
+        earlier(bad_split),
+        earlier(r#"{"Tabs":{"panels":["NoSuchPanel"],"active":0}}"#),
+        earlier(&deep),
+        r#"{"version":1,"workspace":"Default"}"#.into(),
+        r#"{"workspaces":{"Mine":{"Tabs":{"panels":["Composition"],"active":3}}}}"#.into(),
+    ] {
+        let config = MemoryConfig::default();
+        config.write(FILE, &text).unwrap();
+        let mut ui = UiState::default();
+        let mut store = WorkspaceStore::load(Some(&config), &mut ui);
+        assert!(store.error.is_some());
+        assert_eq!(ui.workspace, "Default");
+        assert_eq!(ui.dock, UiState::default().dock);
+        ui.focused = PanelKind::Project;
+        ui.dock = minimal();
+        assert!(!store.save(Some(&config), &ui).unwrap());
+        assert!(store.save_now(Some(&config), &ui).unwrap_err().contains("couldn't be loaded"));
+        assert_eq!(config.read(FILE).as_deref(), Some(text.as_str()));
+        assert_eq!(config.read(BACKUP), None);
+    }
+}
+
+/// A file written by EffectCraft 0.10 (craft-libs 5c874d51): the Default workspace with
+/// Preview floating, Render Queue floating in its own native window, Align closed,
+/// Effects & Presets moved into the Project group and Audio split beside the Timeline,
+/// saved as "My Layout"; then Layer closed.
+const V1: &str = include_str!("../../tests/fixtures/workspaces-v1.json");
+
+#[test]
+fn version_one_file_loads_with_every_panel_in_place() {
+    let config = MemoryConfig::default();
+    config.write(FILE, V1).unwrap();
+    let mut ui = UiState::default();
+    let store = WorkspaceStore::load(Some(&config), &mut ui);
+    assert_eq!(store.error, None);
+    assert_eq!(ui.workspace, "My Layout");
+    assert_eq!(ui.focused, PanelKind::Composition);
+    use PanelKind::*;
+    let root = crate::dock::hsplit(
+        SplitSize::FixedSecond(300.0),
+        crate::dock::vsplit(
+            SplitSize::Ratio(0.56),
+            crate::dock::hsplit(SplitSize::FixedFirst(300.0), crate::dock::tabs(&[Project, EffectControls, EffectsPresets], 2), tabs(&[Composition])),
+            crate::dock::hsplit(SplitSize::Ratio(0.5), tabs(&[Timeline]), tabs(&[Audio])),
+        ),
+        tabs(&[Properties]),
+    );
+    assert_eq!(ui.dock.layout.root, Some(root));
+    let floating: Vec<_> = ui.dock.layout.floating.iter().map(|w| (w.panels().copied().collect::<Vec<_>>(), w.rect, w.native)).collect();
+    assert_eq!(
+        floating,
+        [
+            (vec![Preview], [900.0, 120.0, 300.0, 260.0], None),
+            (vec![RenderQueue], [200.0, 500.0, 520.0, 240.0], Some(crate::dock_ui::sanitized_window_rect([200.0, 500.0, 520.0, 240.0]))),
+        ]
+    );
+    // Closed panels stay closed.
+    for panel in [Align, Layer] {
+        assert!(!ui.dock.is_open(panel), "{panel:?}");
+    }
+    // The native window's place is its outer position until the main window reports its
+    // frame (here a 28-point title bar); the file is not rewritten before.
+    let id = ui.dock.layout.floating[1].id;
+    assert_eq!(ui.native_outer, [id]);
+    let mut store = store;
+    assert!(!store.save(Some(&config), &ui).unwrap());
+    let outer = egui::Rect::from_min_size(egui::pos2(10.0, 20.0), egui::vec2(1600.0, 1000.0));
+    crate::dock_ui::native_outer_to_content(&mut ui, Some(outer), Some(outer.translate(egui::vec2(0.0, 28.0))), 0.1);
+    assert_eq!(ui.dock.layout.floating[1].native, Some([200.0, 528.0, 520.0, 240.0]));
+    assert!(ui.native_outer.is_empty());
+    assert!(store.save(Some(&config), &ui).unwrap());
+    // The named workspace still has Layer, closed only after it was saved.
+    let saved = ui.saved_workspaces.get("My Layout").unwrap();
+    assert!(saved.is_docked(Layer) && saved.is_floating(Preview) && !saved.is_open(Align));
+    assert_eq!(saved.layout.floating.iter().filter_map(|w| w.native).count(), 0);
+}
+
+#[test]
+fn version_one_file_is_rewritten_once_in_the_current_format_and_kept_as_a_backup() {
+    let config = MemoryConfig::default();
+    config.write(FILE, V1).unwrap();
+    let mut ui = UiState::default();
+    let mut store = WorkspaceStore::load(Some(&config), &mut ui);
+    // A backend that reports no window positions: the native place stays as it was.
+    let native = ui.dock.layout.floating[1].native;
+    crate::dock_ui::native_outer_to_content(&mut ui, None, None, 1.0);
+    assert!(!ui.native_outer.is_empty(), "waits for a report");
+    crate::dock_ui::native_outer_to_content(&mut ui, None, None, 5.0);
+    assert!(ui.native_outer.is_empty());
+    assert_eq!(ui.dock.layout.floating[1].native, native);
+    let migrated = Snapshot::capture(&ui);
+    assert!(store.has_changes(&ui), "the migrated layout is written without waiting for an edit");
+    assert!(store.save(Some(&config), &ui).unwrap());
+    assert_eq!(config.read(BACKUP).as_deref(), Some(V1));
+    let text = config.read(FILE).unwrap();
+    assert_eq!(serde_json::from_str::<serde_json::Value>(&text).unwrap()["version"], VERSION);
+    assert!(!store.has_changes(&ui));
+    let mut restored = UiState::default();
+    let reloaded = WorkspaceStore::load(Some(&config), &mut restored);
+    assert_eq!(reloaded.error, None);
+    assert!(!reloaded.has_changes(&restored));
+    assert_eq!(Snapshot::capture(&restored), migrated);
+}
+
+#[test]
+fn stacked_frames_with_tabs_and_an_empty_root_migrate() {
+    let text = r#"{"version":1,"workspace":"Mine","dock":{"Tabs":{"panels":[],"active":0}},
+            "floating":[{"panels":["Project"],"active":0,"rect":[10.0,10.0,300.0,200.0]}],
+            "focused":"Project","maximized":null,
+            "saved_workspaces":{"Mine":{"Stack":{"entries":[{"panel":"Info","open":true},{"panels":["Audio","Preview"],"active":1,"open":true,"height":80.0}]}},
+                "Column":{"Stack":{"entries":[{"panel":"Align","open":false},{"panel":"Preview","open":true,"height":46.0},{"panels":["Properties","Paint"],"active":1,"open":false,"height":300.0},{"panel":"Info","open":true}]}}},
+            "saved_floating":{"Gone":[{"panels":["Align"],"active":0,"rect":[0.0,0.0,100.0,100.0]}]}}"#;
+    let config = MemoryConfig::default();
+    config.write(FILE, text).unwrap();
+    let mut ui = UiState::default();
+    let store = WorkspaceStore::load(Some(&config), &mut ui);
+    assert_eq!(store.error, None);
+    assert_eq!(ui.dock.layout.root, None);
+    assert!(ui.dock.is_floating(PanelKind::Project));
+    use PanelKind::*;
+    // Each open frame is a tab group with all its tabs; a frame's height is a fixed size
+    // (with its tab strip), and the frame without one takes the rest.
+    let column = crate::dock::vsplit(SplitSize::FixedSecond(80.0 + crate::dock::TAB_STRIP), tabs(&[Info]), crate::dock::tabs(&[Audio, Preview], 1));
+    assert_eq!(ui.saved_workspaces.get("Mine").and_then(|w| w.layout.root.clone()), Some(column));
+    // Closed frames' tabs join the open frame above them, or below at the top.
+    let column = crate::dock::vsplit(SplitSize::FixedFirst(46.0 + crate::dock::TAB_STRIP), tabs(&[Preview, Properties, Paint, Align]), tabs(&[Info]));
+    assert_eq!(ui.saved_workspaces.get("Column").and_then(|w| w.layout.root.clone()), Some(column));
+    assert_eq!(ui.saved_workspaces.len(), 2, "floating groups of no named workspace are dropped");
+}
+
+#[test]
+fn explicit_save_without_a_settings_folder_is_an_error() {
+    let mut ui = UiState::default();
+    let mut store = WorkspaceStore::load(None, &mut ui);
+    ui.focused = PanelKind::Project;
+    assert!(!store.save(None, &ui).unwrap());
+    assert!(store.save_now(None, &ui).is_err());
+}
+
+#[test]
+fn explicit_save_with_nothing_new_succeeds() {
+    let config = MemoryConfig::default();
+    let mut ui = UiState::default();
+    let mut store = WorkspaceStore::load(Some(&config), &mut ui);
+    ui.focused = PanelKind::Project;
+    store.save_now(Some(&config), &ui).unwrap();
+    store.save_now(Some(&config), &ui).unwrap();
+    assert!(config.read(FILE).is_some());
+}
+
+#[test]
+fn invalid_tabs_split_and_deep_tree_are_rejected() {
+    let mut snapshot = Snapshot::capture(&UiState::default());
+    snapshot.dock = Workspace::new(Layout { root: Some(Node::Tabs { panels: vec![PanelKind::Project], active: usize::MAX }), floating: vec![] });
+    assert!(snapshot.validate().is_err());
+    let split = |size, first, second| Node::Split { axis: SplitAxis::Horizontal, size, first: Box::new(first), second: Box::new(second) };
+    snapshot.dock = Workspace::new(Layout {
+        root: Some(split(SplitSize::FixedFirst(f32::NAN), tabs(&[PanelKind::Project]), tabs(&[PanelKind::Timeline]))),
+        floating: vec![],
+    });
+    assert!(snapshot.validate().is_err());
+    let mut root = tabs(&[PanelKind::Composition]);
+    for _ in 0..=craft_ui::docking::MAX_DEPTH {
+        root = split(SplitSize::Ratio(0.5), root, tabs(&[]));
+    }
+    snapshot.dock = Workspace::new(Layout { root: Some(root), floating: vec![] });
+    assert!(snapshot.validate().is_err());
+    // A panel in two places.
+    snapshot.dock = Workspace::new(Layout {
+        root: Some(tabs(&[PanelKind::Project])),
+        floating: vec![Floating::single(vec![PanelKind::Project], 0, [0.0, 0.0, 200.0, 100.0])],
+    });
+    assert!(snapshot.validate().is_err());
+}
+
+#[test]
+fn closing_all_docked_panels_remains_a_persistable_layout() {
+    let config = MemoryConfig::default();
+    let mut ui = UiState::default();
+    let mut store = WorkspaceStore::load(Some(&config), &mut ui);
+    for panel in ui.dock.panels() {
+        ui.dock.apply(Action::Close { panel }, crate::dock::permissions).unwrap();
+    }
+    assert!(ui.dock.layout.root.is_none());
+    assert!(store.save(Some(&config), &ui).unwrap());
+    let mut restored = UiState::default();
+    let loaded = WorkspaceStore::load(Some(&config), &mut restored);
+    assert!(loaded.error.is_none());
+    assert_eq!(restored.dock, ui.dock);
+}
+
+#[test]
+fn floating_groups_and_named_snapshots_roundtrip_without_document_state() {
+    let config = MemoryConfig::default();
+    let mut ui = UiState::default();
+    let mut store = WorkspaceStore::load(Some(&config), &mut ui);
+    ui.workspace = "Floating".into();
+    ui.dock.apply(Action::Float { panel: PanelKind::Preview, rect: [50.0, 80.0, 200.0, 160.0] }, crate::dock::permissions).unwrap();
+    ui.dock.apply(Action::Close { panel: PanelKind::Align }, crate::dock::permissions).unwrap();
+    ui.saved_workspaces.insert(ui.workspace.clone(), ui.dock.clone());
+    ui.maximized = Some(PanelKind::Composition);
+    ui.project_search = "do not persist".into();
+    assert!(store.save(Some(&config), &ui).unwrap());
+    let mut restored = UiState::default();
+    WorkspaceStore::load(Some(&config), &mut restored);
+    assert_eq!(Snapshot::capture(&restored), Snapshot::capture(&ui));
+    // The closed panel's place comes back with it.
+    assert!(restored.dock.hidden.iter().any(|(p, _)| *p == PanelKind::Align));
+    assert!(restored.project_search.is_empty());
+}
+
+#[test]
+fn restored_viewer_slots_do_not_reuse_ids_or_restore_document_links() {
+    let config = MemoryConfig::default();
+    let mut ui = UiState::default();
+    let mut store = WorkspaceStore::load(Some(&config), &mut ui);
+    let two = |viewer| Workspace::new(Layout { root: Some(tabs(&[PanelKind::Composition, PanelKind::Viewer(viewer)])), floating: vec![] });
+    ui.dock = two(2);
+    ui.saved_workspaces.insert("Two views".into(), two(5));
+    ui.viewers.insert(2, Some(42));
+    assert!(store.save(Some(&config), &ui).unwrap());
+    let mut app = crate::EffectcraftApp::new(effectcraft_engine::Session::default());
+    WorkspaceStore::load(Some(&config), &mut app.ui);
+    assert_eq!(app.ui.viewers.get(&2), Some(&None));
+    assert_eq!(app.ui.viewers.get(&5), Some(&None));
+    assert_eq!(crate::panels::viewers::new_viewer(&mut app), 6);
+    assert!(app.ui.dock.is_docked(PanelKind::Viewer(2)));
+}
+
+#[test]
+fn invalid_viewer_ids_are_rejected_in_every_workspace_reference() {
+    for id in [0, MAX_VIEWER_ID + 1, u32::MAX] {
+        for location in 0..8 {
+            let mut snapshot = Snapshot::capture(&UiState::default());
+            let panel = PanelKind::Viewer(id);
+            let docked = Workspace::new(Layout { root: Some(tabs(&[panel])), floating: vec![] });
+            let stacked =
+                Workspace::new(Layout { root: Some(Node::Stack { entries: vec![StackEntry { panel, open: true, height: None }] }), floating: vec![] });
+            let floating = Workspace::new(Layout {
+                root: Some(tabs(&[PanelKind::Composition])),
+                floating: vec![Floating::single(vec![panel], 0, [0.0, 0.0, 200.0, 100.0])],
+            });
+            let mut hidden = Workspace::new(Layout { root: Some(tabs(&[PanelKind::Composition, panel])), floating: vec![] });
+            hidden.apply(Action::Close { panel }, crate::dock::permissions).unwrap();
+            match location {
+                0 => snapshot.focused = panel,
+                1 => snapshot.maximized = Some(panel),
+                2 => snapshot.dock = docked,
+                3 => snapshot.dock = stacked,
+                4 => snapshot.dock = floating,
+                5 => snapshot.dock = hidden,
+                6 => {
+                    snapshot.saved_workspaces.insert("Saved".into(), stacked);
+                }
+                _ => {
+                    snapshot.saved_workspaces.insert("Saved".into(), floating);
+                }
+            }
+            assert!(snapshot.validate().is_err(), "viewer {id} at location {location} must be rejected");
+        }
+    }
+}
+
+#[test]
+fn hostile_native_window_places_are_made_safe_on_load() {
+    let config = MemoryConfig::default();
+    let mut ui = UiState::default();
+    let mut store = WorkspaceStore::load(Some(&config), &mut ui);
+    ui.dock.apply(Action::Float { panel: PanelKind::Project, rect: [10.0, 10.0, 300.0, 200.0] }, crate::dock::permissions).unwrap();
+    ui.dock.apply(Action::SetNative { panel: PanelKind::Project, rect: Some([90_000.0, -90_000.0, 1.0e5, 0.5]) }, crate::dock::permissions).unwrap();
+    assert!(store.save(Some(&config), &ui).unwrap());
+    let mut restored = UiState::default();
+    WorkspaceStore::load(Some(&config), &mut restored);
+    let native = restored.dock.layout.floating.iter().find(|w| w.contains(&PanelKind::Project)).and_then(|w| w.native).unwrap();
+    assert_eq!(native, crate::dock_ui::sanitized_window_rect(native));
+    assert!(native[2] <= crate::dock_ui::PANEL_WINDOW_MAX && native[3] >= crate::dock_ui::PANEL_WINDOW_MIN[1]);
+}
+
+#[test]
+fn failed_write_keeps_previous_snapshot_and_retries() {
+    struct Fails<'a>(&'a MemoryConfig);
+    impl ConfigStore for Fails<'_> {
+        fn read(&self, name: &str) -> Option<String> {
+            self.0.read(name)
+        }
+        fn write(&self, _name: &str, _data: &str) -> std::io::Result<()> {
+            Err(std::io::Error::other("synthetic full disk"))
+        }
+        fn remove(&self, _name: &str) -> std::io::Result<()> {
+            Err(std::io::Error::other("unused"))
+        }
+    }
+    let config = MemoryConfig::default();
+    let mut ui = UiState::default();
+    let mut store = WorkspaceStore::load(Some(&config), &mut ui);
+    ui.focused = PanelKind::Project;
+    assert!(store.save(Some(&config), &ui).unwrap());
+    let previous = config.read(FILE).unwrap();
+    ui.focused = PanelKind::Timeline;
+    assert!(store.save(Some(&Fails(&config)), &ui).unwrap_err().contains("synthetic full disk"));
+    assert_eq!(config.read(FILE).as_deref(), Some(previous.as_str()));
+    assert!(store.has_changes(&ui));
+    assert!(store.save(Some(&config), &ui).unwrap());
+    let mut restored = UiState::default();
+    WorkspaceStore::load(Some(&config), &mut restored);
+    assert_eq!(restored.focused, PanelKind::Timeline);
+}
diff --git a/crates/ui-egui/tests/it/ui_font_search.rs b/crates/ui-egui/tests/it/ui_font_search.rs
index 6be69cb7a..122003abe 100644
--- a/crates/ui-egui/tests/it/ui_font_search.rs
+++ b/crates/ui-egui/tests/it/ui_font_search.rs
@@ -176,3 +176,37 @@ fn font_menu_filters_variable_fonts() {
     key(&mut h, Key::Escape);
     assert_eq!(layer_doc(&h.state().session, LayerId(lid)).unwrap().font, "Inter", "filtering changes nothing");
 }
+
+/// The font menu grows back when a query that matched nothing is cleared, while the search
+/// field keeps its place and the keyboard; a click on a row then picks that font.
+#[test]
+fn font_menu_grows_back_after_an_empty_search() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"width": 320, "height": 180})).unwrap();
+    let lid = s.execute("layer.newText", json!({"text": "Grow", "font": "Inter"})).unwrap()["layer"].as_u64().unwrap();
+    let mut h = Harness::builder().with_size(egui::vec2(1600.0, 1000.0)).build_eframe(move |_| EffectcraftApp::new(s));
+    h.state_mut().show_panel(PanelKind::Character);
+    h.run_steps(3);
+    let rows = |h: &Harness<'_, EffectcraftApp>| h.state().auto.query("character.font.option.").len();
+    let search = |h: &Harness<'_, EffectcraftApp>| h.state().auto.find("character.font.search").map(|e| e.rect);
+    click(&mut h, "character.font");
+    h.run_steps(2);
+    let (full, field) = (rows(&h), search(&h));
+    assert!(full > 3, "the open menu shows the fonts: {full} rows");
+    let query = "no_such_font_123456789";
+    type_text(&mut h, query);
+    assert_eq!(rows(&h), 0);
+    assert!(h.state().auto.find("character.font.empty").is_some());
+    for pressed in query.chars().flat_map(|_| [true, false]) {
+        h.input_mut().events.push(Event::Key { key: Key::Backspace, physical_key: None, pressed, repeat: false, modifiers: Modifiers::NONE });
+    }
+    h.run_steps(3);
+    // (Within a row: the list scrolls to the current font on opening and to the top when cleared.)
+    assert!(rows(&h) + 1 >= full, "cleared, the menu shows as many fonts as when it opened: {} of {full}", rows(&h));
+    assert_eq!(search(&h), field, "the search field stays put");
+    // The field still has the keyboard: typing filters again.
+    type_text(&mut h, "JetBrains");
+    assert!(rows(&h) > 0 && h.state().auto.query("character.font.option.").iter().all(|r| r.label.contains("JetBrains")));
+    click(&mut h, "character.font.option.JetBrains Mono");
+    assert_eq!(layer_doc(&h.state().session, LayerId(lid)).unwrap().font, "JetBrains Mono", "a click on a row picks the font");
+}
diff --git a/crates/ui-egui/tests/it/ui_gpu.rs b/crates/ui-egui/tests/it/ui_gpu.rs
index 906ac0cd1..355c35bf5 100644
--- a/crates/ui-egui/tests/it/ui_gpu.rs
+++ b/crates/ui-egui/tests/it/ui_gpu.rs
@@ -115,5 +115,12 @@ fn a_lost_device_draws_nothing_autosaves_and_closes() {
     let saved = h.state().session.autosave.last_path.clone().expect("unsaved changes auto-saved");
     assert!(std::path::Path::new(&saved).is_file(), "{saved}");
     assert_eq!(*told.borrow(), vec![Some(Ok(saved))], "the user is told once, with the recovery copy");
+    // The close arrives: on macOS the app quits through `-[NSApplication terminate:]` instead of
+    // closing the window while AppKit's run loop is running (#341).
+    h.input_mut().viewports.entry(egui::ViewportId::ROOT).or_default().events.push(egui::ViewportEvent::Close);
+    h.step();
+    let kept = h.output().viewport_output.get(&egui::ViewportId::ROOT).is_some_and(|v| v.commands.contains(&egui::ViewportCommand::CancelClose));
+    assert_eq!(kept, cfg!(target_os = "macos"), "the platform quit closes the window on macOS");
+    assert_eq!(told.borrow().len(), 1);
     let _ = std::fs::remove_dir_all(&dir);
 }
diff --git a/crates/vp9enc/src/lf.rs b/crates/vp9enc/src/lf.rs
index d781144fe..d48c57db5 100644
--- a/crates/vp9enc/src/lf.rs
+++ b/crates/vp9enc/src/lf.rs
@@ -13,6 +13,14 @@ struct Limits {
     thresh: i32,
 }
 
+/// Mode-info grid and thresholds shared by every superblock of this frame.
+struct FrameFilter<'a> {
+    mi: &'a [Mi],
+    mi_rows: usize,
+    mi_cols: usize,
+    limits: Limits,
+}
+
 /// Filter the reconstructed planes (Y, U, V, or a prefix of them) in place at `level` (0 = off;
 /// sharpness 0).
 pub fn filter_frame(planes: &mut [Plane], mi: &[Mi], mi_rows: usize, mi_cols: usize, level: u8) {
@@ -22,61 +30,182 @@ pub fn filter_frame(planes: &mut [Plane], mi: &[Mi], mi_rows: usize, mi_cols: us
     let l = level as i32;
     let limit = l.max(1);
     let lim = Limits { limit, blimit: 2 * (l + 2) + limit, thresh: l >> 4 };
+    let filter = FrameFilter { mi, mi_rows, mi_cols, limits: lim };
     for sbr in 0..mi_rows.div_ceil(8) {
         for sbc in 0..mi_cols.div_ceil(8) {
             for (plane, p) in planes.iter_mut().enumerate() {
                 for pass in 0..2 {
-                    sb_plane(p, mi, mi_rows, mi_cols, plane, pass, sbr * 8, sbc * 8, lim);
+                    filter.sb_plane(p, plane, pass, sbr * 8, sbc * 8);
                 }
             }
         }
     }
 }
 
-#[allow(clippy::too_many_arguments)]
-fn sb_plane(p: &mut Plane, mi: &[Mi], mi_rows: usize, mi_cols: usize, plane: usize, pass: usize, row: usize, col: usize, lim: Limits) {
-    let (sx, sy) = if plane > 0 { (1, 1) } else { (0, 0) };
-    let (sub, edge_len) = if pass == 0 { (sx, 64 >> sy) } else { (sy, 64 >> sx) };
-    let stride = p.w;
-    for edge in 0..(16usize >> sub) {
-        let mut i = 0;
-        while i < edge_len {
-            let (x, y) = if pass == 0 { (col * 8 + edge * (4 << sx), row * 8 + (i << sy)) } else { (col * 8 + (i << sx), row * 8 + edge * (4 << sy)) };
-            if x >= 8 * mi_cols || y >= 8 * mi_rows || (pass == 0 && x == 0) || (pass == 1 && y == 0) {
-                i += 8;
-                continue;
-            }
-            let lc = ((x >> 3) >> sx) << sx;
-            let lr = ((y >> 3) >> sy) << sy;
-            let m = mi[lr * mi_cols + lc];
-            let size = if sub == 0 { m.size } else { m.size.max(BLOCK_16X16) };
-            let n8 = if size >= BLOCK_16X16 { 2 } else { 1 };
-            let is_block_edge = if pass == 0 { x & (8 * n8 - 1) == 0 } else { y & (8 * n8 - 1) == 0 };
-            let tx_ok = !m.inter || !m.skip;
-            if !is_block_edge && !tx_ok {
-                i += 8;
-                continue;
-            }
-            let wide = edge % 8 == 0;
-            let n = if pass == 0 { (8 * mi_rows - y).div_ceil(1 << sy) } else { (8 * mi_cols - x).div_ceil(1 << sx) }.min(8).min(edge_len - i);
-            // A transform edge is not filtered in the last odd chroma column.
-            let odd_last = pass == 1 && sx == 1 && mi_cols & 1 == 1 && edge & 1 == 1;
-            let (px, py) = (x >> sx, y >> sy);
-            for l in 0..n {
-                let is_tx_edge = tx_ok && !(odd_last && x + (l << sx) + 8 >= mi_cols * 8);
-                if !(is_block_edge || is_tx_edge) {
+impl FrameFilter<'_> {
+    fn sb_plane(&self, p: &mut Plane, plane: usize, pass: usize, row: usize, col: usize) {
+        let Self { mi, mi_rows, mi_cols, limits: lim } = *self;
+        let (sx, sy) = if plane > 0 { (1, 1) } else { (0, 0) };
+        let (sub, edge_len) = if pass == 0 { (sx, 64 >> sy) } else { (sy, 64 >> sx) };
+        let stride = p.w;
+        for edge in 0..(16usize >> sub) {
+            let mut i = 0;
+            while i < edge_len {
+                let (x, y) = if pass == 0 { (col * 8 + edge * (4 << sx), row * 8 + (i << sy)) } else { (col * 8 + (i << sx), row * 8 + edge * (4 << sy)) };
+                if x >= 8 * mi_cols || y >= 8 * mi_rows || (pass == 0 && x == 0) || (pass == 1 && y == 0) {
+                    i += 8;
                     continue;
                 }
-                let (pos, step) = if pass == 0 { ((py + l) * stride + px, 1) } else { (py * stride + px + l, stride) };
-                filter_lane(&mut p.rec, pos, step, wide, lim);
+                let lc = ((x >> 3) >> sx) << sx;
+                let lr = ((y >> 3) >> sy) << sy;
+                let m = mi[lr * mi_cols + lc];
+                let size = if sub == 0 { m.size } else { m.size.max(BLOCK_16X16) };
+                let n8 = if size >= BLOCK_16X16 { 2 } else { 1 };
+                let is_block_edge = if pass == 0 { x & (8 * n8 - 1) == 0 } else { y & (8 * n8 - 1) == 0 };
+                let tx_ok = !m.inter || !m.skip;
+                if !is_block_edge && !tx_ok {
+                    i += 8;
+                    continue;
+                }
+                let wide = edge % 8 == 0;
+                let n = if pass == 0 { (8 * mi_rows - y).div_ceil(1 << sy) } else { (8 * mi_cols - x).div_ceil(1 << sx) }.min(8).min(edge_len - i);
+                // A transform edge is not filtered in the last odd chroma column.
+                let odd_last = pass == 1 && sx == 1 && mi_cols & 1 == 1 && edge & 1 == 1;
+                let (px, py) = (x >> sx, y >> sy);
+                let mut apply = [false; LANES];
+                for (l, a) in apply.iter_mut().enumerate().take(n) {
+                    let is_tx_edge = tx_ok && !(odd_last && x + (l << sx) + 8 >= mi_cols * 8);
+                    *a = is_block_edge || is_tx_edge;
+                }
+                if apply.iter().any(|&a| a) {
+                    let pos = py * stride + px;
+                    if pass == 0 {
+                        filter_group::<false>(&mut p.rec, pos, stride, 1, apply, wide, lim);
+                    } else {
+                        filter_group::<true>(&mut p.rec, pos, 1, stride, apply, wide, lim);
+                    }
+                }
+                i += 8;
+            }
+        }
+    }
+}
+
+const LANES: usize = 8;
+
+/// [`filter_lane`] on the 8 lanes of a group at once (lane `l` has its q0 at `pos + l * along`;
+/// samples across the edge are `step` apart; `ROWS`: `along` is 1), for lanes whose `apply` is
+/// set. Every lane is computed with both filters and the result selected per lane (0 / -1
+/// masks), so the arithmetic vectorizes; lanes left alone are written back unchanged.
+#[inline(always)]
+fn filter_group<const ROWS: bool>(d: &mut [u8], pos: usize, along: usize, step: usize, apply: [bool; LANES], wide: bool, lim: Limits) {
+    type T = i16;
+    let mut v = [[0 as T; LANES]; 8];
+    let start = pos - 4 * step;
+    if ROWS {
+        for (k, vk) in v.iter_mut().enumerate() {
+            let Some(row) = d.get(start + k * step..).and_then(|r| r.first_chunk::<LANES>()) else { return };
+            *vk = row.map(|s| s as T);
+        }
+    } else {
+        for l in 0..LANES {
+            let Some(line) = d.get(start + l * along..).and_then(|r| r.first_chunk::<8>()) else { return };
+            for k in 0..8 {
+                v[k][l] = line[k] as T;
+            }
+        }
+    }
+    let (limit, blimit, thresh) = (lim.limit as T, lim.blimit as T, lim.thresh as T);
+    let le = |a: T, b: T| -((a <= b) as T);
+    let sel = |m: T, a: T, b: T| (a & m) | (b & !m);
+    let (p3, p2, p1, p0, q0, q1, q2, q3) = (&v[0], &v[1], &v[2], &v[3], &v[4], &v[5], &v[6], &v[7]);
+    let apply: [T; LANES] = apply.map(|a| -(a as T));
+    let can_flat = -(wide as T);
+    let mut mask = [0 as T; LANES];
+    let mut hev = [0 as T; LANES];
+    let mut flat = [0 as T; LANES];
+    for l in 0..LANES {
+        let d10 = (p1[l] - p0[l]).abs();
+        let e10 = (q1[l] - q0[l]).abs();
+        mask[l] = apply[l]
+            & le((p3[l] - p2[l]).abs(), limit)
+            & le((p2[l] - p1[l]).abs(), limit)
+            & le(d10, limit)
+            & le(e10, limit)
+            & le((q2[l] - q1[l]).abs(), limit)
+            & le((q3[l] - q2[l]).abs(), limit)
+            & le((p0[l] - q0[l]).abs() * 2 + (p1[l] - q1[l]).abs() / 2, blimit);
+        hev[l] = !(le(d10, thresh) & le(e10, thresh));
+        flat[l] = can_flat
+            & mask[l]
+            & le(d10, 1)
+            & le(e10, 1)
+            & le((p2[l] - p0[l]).abs(), 1)
+            & le((q2[l] - q0[l]).abs(), 1)
+            & le((p3[l] - p0[l]).abs(), 1)
+            & le((q3[l] - q0[l]).abs(), 1);
+    }
+    if mask.iter().fold(0, |a, &m| a | m) == 0 {
+        return;
+    }
+    let mut out = v;
+    let c = |x: T| x.clamp(-128, 127);
+    for l in 0..LANES {
+        let (ps1, ps0, qs0, qs1) = (p1[l] - 128, p0[l] - 128, q0[l] - 128, q1[l] - 128);
+        let filter = c((c(ps1 - qs1) & hev[l]) + 3 * (qs0 - ps0));
+        let f1 = c(filter + 4) >> 3;
+        let f2 = c(filter + 3) >> 3;
+        let f = (f1 + 1) >> 1;
+        let narrow = mask[l] & !flat[l];
+        let outer = narrow & !hev[l];
+        out[4][l] = sel(narrow, c(qs0 - f1) + 128, out[4][l]);
+        out[3][l] = sel(narrow, c(ps0 + f2) + 128, out[3][l]);
+        out[5][l] = sel(outer, c(qs1 - f) + 128, out[5][l]);
+        out[2][l] = sel(outer, c(ps1 + f) + 128, out[2][l]);
+    }
+    if flat.iter().fold(0, |a, &f| a | f) != 0 {
+        // 8-tap: positions p2..q2 (indices 1..7), each the rounded mean of a 7-wide window
+        // (indices clamped to 0..8) plus itself, as a sliding sum.
+        let s = |k: isize| &v[k.clamp(0, 7) as usize];
+        let mut sum = [0 as T; LANES];
+        for j in -2isize..=4 {
+            let a = s(j);
+            for l in 0..LANES {
+                sum[l] += a[l];
+            }
+        }
+        for k in 1usize..7 {
+            let ki = k as isize;
+            let (cur, add, sub) = (s(ki), s(ki + 4), s(ki - 3));
+            for l in 0..LANES {
+                let w8 = (sum[l] + cur[l] + 4) >> 3;
+                out[k][l] = sel(flat[l], w8, out[k][l]);
+                sum[l] += add[l] - sub[l];
+            }
+        }
+    }
+    if ROWS {
+        for (k, ok) in out.iter().enumerate().take(7).skip(1) {
+            if let Some(row) = d.get_mut(start + k * step..).and_then(|r| r.first_chunk_mut::<LANES>()) {
+                for l in 0..LANES {
+                    row[l] = ok[l] as u8;
+                }
+            }
+        }
+    } else {
+        for l in 0..LANES {
+            if let Some(line) = d.get_mut(start + l * along..).and_then(|r| r.first_chunk_mut::<8>()) {
+                for k in 1..7 {
+                    line[k] = out[k][l] as u8;
+                }
             }
-            i += 8;
         }
     }
 }
 
 /// Filter mask, narrow (4-tap) and 8-tap flat filters of spec 8.8.5 across one edge position;
 /// `pos` is q0, samples across the edge are `step` apart.
+#[cfg(test)]
 fn filter_lane(d: &mut [u8], pos: usize, step: usize, wide: bool, lim: Limits) {
     let at = |k: isize| d[(pos as isize + k * step as isize) as usize] as i32;
     let (p3, p2, p1, p0) = (at(-4), at(-3), at(-2), at(-1));
@@ -122,3 +251,49 @@ fn filter_lane(d: &mut [u8], pos: usize, step: usize, wide: bool, lim: Limits) {
         set(-2, c(ps1 + f) + 128);
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn group_matches_per_lane_filter() {
+        let mut seed = 0x1234_5678u32;
+        let mut rnd = || {
+            seed ^= seed << 13;
+            seed ^= seed >> 17;
+            seed ^= seed << 5;
+            seed
+        };
+        for case in 0..20000 {
+            let stride = 24;
+            let base: Vec<u8> = {
+                let flatish = case % 3 == 0;
+                let c = (rnd() % 256) as i32;
+                (0..stride * 24)
+                    .map(|_| if flatish { (c + (rnd() % 3) as i32 - 1).clamp(0, 255) as u8 } else { (c + (rnd() % 40) as i32 - 20).clamp(0, 255) as u8 })
+                    .collect()
+            };
+            let l = (rnd() % 64) as i32;
+            let lim = Limits { limit: l.max(1), blimit: 2 * (l + 2) + l.max(1), thresh: l >> 4 };
+            let wide = rnd() & 1 == 1;
+            let apply: [bool; LANES] = std::array::from_fn(|_| rnd() % 4 != 0);
+            for pass in 0..2 {
+                let (mut a, mut b) = (base.clone(), base.clone());
+                let pos = 8 * stride + 8;
+                for (l, &ap) in apply.iter().enumerate() {
+                    if ap {
+                        let (p, st) = if pass == 0 { (pos + l * stride, 1) } else { (pos + l, stride) };
+                        filter_lane(&mut a, p, st, wide, lim);
+                    }
+                }
+                if pass == 0 {
+                    filter_group::<false>(&mut b, pos, stride, 1, apply, wide, lim);
+                } else {
+                    filter_group::<true>(&mut b, pos, 1, stride, apply, wide, lim);
+                }
+                assert_eq!(a, b, "case {case} pass {pass}");
+            }
+        }
+    }
+}
diff --git a/crates/vp9enc/src/lib.rs b/crates/vp9enc/src/lib.rs
index 9364dfaa1..b9b56b693 100644
--- a/crates/vp9enc/src/lib.rs
+++ b/crates/vp9enc/src/lib.rs
@@ -85,7 +85,6 @@ pub(crate) struct Plane {
 }
 
 impl Plane {
-    #[allow(clippy::too_many_arguments)]
     fn new(data: &[u8], vw: usize, vh: usize, w: usize, h: usize, max_x: usize, max_y: usize) -> Plane {
         let mut src = vec![0u8; w * h];
         for y in 0..h {
diff --git a/crates/vp9enc/src/probs.rs b/crates/vp9enc/src/probs.rs
index 8f55bbba3..57af2e29b 100644
--- a/crates/vp9enc/src/probs.rs
+++ b/crates/vp9enc/src/probs.rs
@@ -9,7 +9,11 @@
 //! entropy codes the recorded symbols with the updated probabilities.
 
 use crate::bool::BoolEncoder;
-use crate::tables::*;
+use crate::tables::{
+    DEFAULT_COEF_PROBS, DEFAULT_INTER_MODE_PROBS, DEFAULT_IS_INTER_PROB, DEFAULT_MV_BITS_PROB, DEFAULT_MV_CLASS_PROBS, DEFAULT_MV_CLASS0_BIT_PROB,
+    DEFAULT_MV_CLASS0_FR_PROBS, DEFAULT_MV_FR_PROBS, DEFAULT_MV_JOINT_PROBS, DEFAULT_MV_SIGN_PROB, DEFAULT_PARTITION_PROBS, DEFAULT_SINGLE_REF_PROB,
+    DEFAULT_SKIP_PROB, PARETO_TABLE, inv_map_table,
+};
 
 /// Coefficient probabilities `[ptype][ref][band][ctx][3]` for 4×4 transforms (band 0 uses
 /// contexts 0..3 only).
diff --git a/crates/vp9enc/src/tables.rs b/crates/vp9enc/src/tables.rs
index ffb266419..c70d7d8c2 100644
--- a/crates/vp9enc/src/tables.rs
+++ b/crates/vp9enc/src/tables.rs
@@ -2,8 +2,6 @@
 //! transcribed in FilmCraft's first-party decoder `filmcraft-vp9` (MIT OR Apache-2.0, the same
 //! licence as this crate).
 
-#![allow(clippy::unreadable_literal)]
-
 pub const DC_QLOOKUP: [i32; 256] = [
     4, 8, 8, 9, 10, 11, 12, 12, 13, 14, 15, 16, 17, 18, 19, 19, 20, 21, 22, 23, 24, 25, 26, 26, 27, 28, 29, 30, 31, 32, 32, 33, 34, 35, 36, 37, 38, 38, 39, 40,
     41, 42, 43, 43, 44, 45, 46, 47, 48, 48, 49, 50, 51, 52, 53, 53, 54, 55, 56, 57, 57, 58, 59, 60, 61, 62, 62, 63, 64, 65, 66, 66, 67, 68, 69, 70, 70, 71, 72,
diff --git a/crates/vp9enc/src/tile.rs b/crates/vp9enc/src/tile.rs
index d7f6cb64f..1f0c37d80 100644
--- a/crates/vp9enc/src/tile.rs
+++ b/crates/vp9enc/src/tile.rs
@@ -8,7 +8,10 @@
 
 use crate::mc::{Mv, PhasePlanes, RefPlane, clamp_for_plane, predict};
 use crate::probs::{self, P, Writer, cost, tree_cost};
-use crate::tables::*;
+use crate::tables::{
+    COEFBAND_4X4, COL_SCAN_4X4, COUNTER_TO_CONTEXT, DEFAULT_SCAN_4X4, ENERGY_CLASS, KF_PARTITION_PROBS, KF_UV_MODE_PROBS, KF_Y_MODE_PROBS, MODE_2_COUNTER,
+    MV_REF_8X8, MV_REF_16X16, ROW_SCAN_4X4,
+};
 use crate::transform::{ADST_ADST, ADST_DCT, DCT_ADST, DCT_DCT, Quant};
 use crate::{BLOCK_8X8, BLOCK_16X16, Mi, Plane};
 
@@ -22,6 +25,13 @@ pub const NEARMV: u8 = 11;
 pub const ZEROMV: u8 = 12;
 pub const NEWMV: u8 = 13;
 
+/// Which reconstructed neighbours are available for intra prediction.
+#[derive(Clone, Copy)]
+struct IntraEdges {
+    left: bool,
+    above: bool,
+}
+
 const PARTITION_TREE: [i8; 6] = [0, 2, -1, 4, -2, -3];
 const INTRA_MODE_TREE: [i8; 18] = [0, 2, -9, 4, -1, 6, 8, 12, -2, 10, -4, -5, -3, 14, -8, 16, -6, -7];
 /// Leaves are `mode - NEARESTMV`.
@@ -104,7 +114,8 @@ fn levels_cost(levels: &[i32; 16], eob: usize) -> u32 {
 }
 
 /// Intra prediction (8.5.1) of a square block for DC / V / H / TM.
-fn predict_intra(p: &Plane, x: usize, y: usize, log2: usize, mode: u8, have_left: bool, have_above: bool) -> [i32; 64] {
+fn predict_intra(p: &Plane, x: usize, y: usize, log2: usize, mode: u8, edges: IntraEdges) -> [i32; 64] {
+    let IntraEdges { left: have_left, above: have_above } = edges;
     let size = 1usize << log2;
     let base = 128i32;
     let buf = &p.rec;
@@ -356,11 +367,11 @@ impl<'a> Tile<'a> {
     fn intra_block(&mut self, r: usize, c: usize) {
         let avail_u = r > 0;
         let avail_l = c > self.col_start;
-        let y_mode = self.choose_intra(0, c * 8, r * 8, 3, avail_l, avail_u);
+        let y_mode = self.choose_intra(0, c * 8, r * 8, 3, IntraEdges { left: avail_l, above: avail_u });
         let uv_mode = {
             let mut best = (i64::MAX, DC_PRED);
             for m in MODES {
-                let cost: i64 = (1..3).map(|p| self.intra_cost(p, c * 4, r * 4, 2, m, avail_l, avail_u)).sum();
+                let cost: i64 = (1..3).map(|p| self.intra_cost(p, c * 4, r * 4, 2, m, IntraEdges { left: avail_l, above: avail_u })).sum();
                 if cost < best.0 {
                     best = (cost, m);
                 }
@@ -379,17 +390,16 @@ impl<'a> Tile<'a> {
         // Residual: luma 2×2 transform blocks, then one 4×4 block per chroma plane.
         for (dy, dx) in [(0, 0), (0, 1), (1, 0), (1, 1)] {
             let tx = if self.f.quant.lossless { DCT_DCT } else { mode_tx_type(y_mode) };
-            self.intra_tx(0, c * 8 + dx * 4, r * 8 + dy * 4, y_mode, tx, avail_l || dx > 0, avail_u || dy > 0);
+            self.intra_tx(0, c * 8 + dx * 4, r * 8 + dy * 4, y_mode, tx, IntraEdges { left: avail_l || dx > 0, above: avail_u || dy > 0 });
         }
         for p in 1..3 {
-            self.intra_tx(p, c * 4, r * 4, uv_mode, DCT_DCT, avail_l, avail_u);
+            self.intra_tx(p, c * 4, r * 4, uv_mode, DCT_DCT, IntraEdges { left: avail_l, above: avail_u });
         }
     }
 
-    #[allow(clippy::too_many_arguments)]
-    fn intra_cost(&self, plane: usize, x: usize, y: usize, log2: usize, mode: u8, have_left: bool, have_above: bool) -> i64 {
+    fn intra_cost(&self, plane: usize, x: usize, y: usize, log2: usize, mode: u8, edges: IntraEdges) -> i64 {
         let p = &self.planes[plane];
-        let pred = predict_intra(p, x, y, log2, mode, have_left, have_above);
+        let pred = predict_intra(p, x, y, log2, mode, edges);
         let size = 1 << log2;
         let mut s = 0i64;
         for i in 0..size {
@@ -400,10 +410,10 @@ impl<'a> Tile<'a> {
         s
     }
 
-    fn choose_intra(&self, plane: usize, x: usize, y: usize, log2: usize, have_left: bool, have_above: bool) -> u8 {
+    fn choose_intra(&self, plane: usize, x: usize, y: usize, log2: usize, edges: IntraEdges) -> u8 {
         let mut best = (i64::MAX, DC_PRED);
         for m in MODES {
-            let cost = self.intra_cost(plane, x, y, log2, m, have_left, have_above);
+            let cost = self.intra_cost(plane, x, y, log2, m, edges);
             if cost < best.0 {
                 best = (cost, m);
             }
@@ -411,8 +421,7 @@ impl<'a> Tile<'a> {
         best.1
     }
 
-    #[allow(clippy::too_many_arguments)]
-    fn intra_tx(&mut self, plane: usize, x: usize, y: usize, mode: u8, tx_type: u8, have_left: bool, have_above: bool) {
+    fn intra_tx(&mut self, plane: usize, x: usize, y: usize, mode: u8, tx_type: u8, edges: IntraEdges) {
         let ss = (plane > 0) as usize;
         let max_x = (self.f.mi_cols * 8) >> ss;
         let max_y = (self.f.mi_rows * 8) >> ss;
@@ -424,7 +433,7 @@ impl<'a> Tile<'a> {
             return;
         }
         let p = &self.planes[plane];
-        let pred = predict_intra(p, x, y, 2, mode, have_left, have_above);
+        let pred = predict_intra(p, x, y, 2, mode, edges);
         let mut res = [0i32; 16];
         for i in 0..4 {
             for j in 0..4 {
diff --git a/docs/agents.md b/docs/agents.md
index aae8be12c..d2b691b18 100644
--- a/docs/agents.md
+++ b/docs/agents.md
@@ -54,13 +54,13 @@ The release packages ship `effectcraft-cli` alongside the desktop app, so no bui
 
 | Install | CLI |
 |---|---|
-| Windows (MSI) | `C:\Program Files\EffectCraft\effectcraft-cli.exe` by default (wherever you installed it otherwise), not on `PATH` |
+| Windows (MSI) | `%LOCALAPPDATA%\Programs\ArtCraft\EffectCraft\effectcraft-cli.exe` by default (`C:\Program Files\ArtCraft\EffectCraft\effectcraft-cli.exe` for an all-users install, under `Program Files (x86)` instead for the 32-bit build, or wherever you installed it otherwise), not on `PATH` |
 | Linux (deb, rpm) | `/usr/bin/effectcraft-cli` |
 | macOS | the separate `effectcraft-cli-<version>-macos-<arch>.zip` release asset (the `.app` holds only the desktop app) |
 
 ```sh
-# Windows, default install folder
-claude mcp add effectcraft -- "C:\Program Files\EffectCraft\effectcraft-cli.exe" mcp
+# Windows (PowerShell), default install folder
+claude mcp add effectcraft -- "$env:LOCALAPPDATA\Programs\ArtCraft\EffectCraft\effectcraft-cli.exe" mcp
 # Linux, or macOS with the CLI unzipped onto PATH
 claude mcp add effectcraft -- effectcraft-cli mcp
 ```
diff --git a/docs/effects-parity.md b/docs/effects-parity.md
index 6defcba8e..83e9a15bc 100644
--- a/docs/effects-parity.md
+++ b/docs/effects-parity.md
@@ -15,7 +15,7 @@ After Effects', and does the preset library exist. The per-effect catalogue is t
 | Parameter names, order, popups, units, defaults | aligned in M9.12 | Agent-checked against After Effects' documentation, not against a live dump |
 | On the GPU | **280** (92%) | Measured: registry flags; GPU vs CPU agreement tested per effect |
 | 32-bit float, no clamping | 306 | Measured: registry flags |
-| **Rendered output matches After Effects** | **partly measured** | Some colour effects are checked against After Effects 2026 renders of our own test projects: Tint, Tritone, Black & White, Exposure, Levels, Curves, Luma Key, Extract, 4-Color Gradient and Fill within 1–3/255, Brightness & Contrast up to 6.2/255 (Color Correction, Generate and Keying rows below); every other effect is unmeasured. `effectcraft_effects::fidelity::compare_frames` exists for the corpus ([fidelity/README.md](fidelity/README.md)); simulation effects are pinned by golden hashes of our own output (M13.27) |
+| **Rendered output matches After Effects** | **partly measured** | Some colour effects are checked against After Effects 2026 renders of our own test projects: Tint, Tritone, Black & White, Exposure, Levels, Curves, Luma Key, Extract, 4-Color Gradient and Fill within 1–3/255, Brightness & Contrast up to 6.2/255 (Color Correction, Generate and Keying rows below); Radial Blur, Glow, Venetian Blinds, Radial Wipe, Fractal / Turbulent Noise and Transform are checked the same way (rows below); every other effect is unmeasured. `effectcraft_effects::fidelity::compare_frames` exists for the corpus ([fidelity/README.md](fidelity/README.md)); simulation effects are pinned by golden hashes of our own output (M13.27) |
 | Animation presets | **54** original presets (8 text-animator, 23 Transitions, 23 Backgrounds) against After Effects' **621** `.ffx` presets | Measured: `crates/engine/presets/text_animators.json`, `crates/engine/presets/transitions.json`, `crates/engine/presets/backgrounds.json`; the After Effects `Presets` folder |
 | 26.x additions | Curl Noise (26.3) present (#463 open); effect colour labels (26.5) present in Effect Controls only, not in the Timeline; the rebuilt Effect Controls (26.5) missing | Release notes |
 
@@ -28,24 +28,24 @@ corpus compares renders, each effect is assumed to differ somewhere, and users k
 |---|---:|---:|---|
 | 3D Channel | 8 | 8 | Cryptomatte selection can't be set in the UI and the GPU path is slow (#473; quoted names with commas fixed); multi-layer EXR decode shared (#474 open: f16 storage and cache sizing remain) |
 | Audio | 13 | 0 | CPU by design (applied in the mixdown) |
-| Blur & Sharpen | 16 | 15 | Gaussian Blur interaction and output to be measured first ([fidelity/ae-2026-acceptance.md](fidelity/ae-2026-acceptance.md)) |
+| Blur & Sharpen | 16 | 15 | Radial Blur keeps the layer edges as After Effects 2026 (713 now pixel-identical); Gaussian Blur interaction and output to be measured first ([fidelity/ae-2026-acceptance.md](fidelity/ae-2026-acceptance.md)) |
 | Channel | 13 | 13 | — |
 | Color Correction | 40 | 40 | Tint, Tritone and Black & White (sliders and Tint) match After Effects 2026 renders (Rec. 601 luminance); Levels (Individual Controls) matches After Effects 2026 in 32 bpc (channel controls before RGB, "Off for 32 bpc Color" unclipped; plain Levels' channel order not measured); Brightness & Contrast (non-legacy) close to After Effects 2026 ramps, not identical (up to 6.2/255 off; the test allows 7/255) (negative settings invert the positive curves); Curves interpolates a natural cubic spline through its points, as After Effects 2026 (exact on its grey steps); Tint has Swap Colors (#963); ACES 2.0 / OCIO 2.5 (26.5); Apply Color LUT (#514) and 32-bpc blending (#494) are closed |
-| Distort | 39 | 35 | Liquify has no viewer brush; #303 (Mesh Warp drag) and #534 (CC Power Pin Unstretch) are closed |
+| Distort | 39 | 35 | Transform matches After Effects 2026 renders (skew after rotation, drawn outside the layer); Liquify has no viewer brush; #303 (Mesh Warp drag) and #534 (CC Power Pin Unstretch) are closed |
 | Expression Controls | 9 | 9 | — |
 | Generate | 26 | 25 | 4-Color Gradient's Blend matches After Effects 2026 (weights 1 / (d² + Blend²)); Fill's Opacity is the filled layer's opacity, as After Effects 2026 renders it (with a Fill Mask it still mixes with the original, not measured); Fractal on the CPU (needs f64); #526 (Reset) and #536 (Write-on marks) are closed |
 | Immersive Video | 12 | 12 | — |
 | Keying | 12 | 12 | Luma Key and Extract key on Rec. 601 luminance, as After Effects 2026; Key Cleaner approximated; #533 (wire-removal Frame Offset) is closed |
 | Matte | 6 | 4 | Mocha shape reads our documented JSON, not Mocha's format |
-| Noise & Grain | 13 | 12 | Curl Noise (#463); Match Grain on the CPU |
+| Noise & Grain | 13 | 12 | Fractal / Turbulent Noise lattice matches After Effects 2026 (Scale 100 = 66.7 px cells); the noise values themselves differ (seeds) and Soft Linear contrast is about 20 % lower than AE's; Curl Noise (#463); Match Grain on the CPU |
 | Obsolete | 9 | 9 | Luma Key matches After Effects 2026 on a grey ramp (hard cut, Tolerance only for Similar / Dissimilar) |
 | Paint | 1 | 0 | Tablet pressure not read ([hardware-parity.md](hardware-parity.md)) |
 | Perspective | 10 | 9 | Chromatic Aberrations pan/tilt crash (#580) |
 | Simulation | 18 | 18 | Particle Playground lacks Particle Exploder, text particles, ephemeral mapper; CC Particle World camera fixed (#397) |
-| Stylize | 25 | 25 | Motion Tile output size (#369) |
+| Stylize | 25 | 25 | Glow's halo (coverage of a dim layer's edge) and blur width match After Effects 2026 renders; glows above the threshold match too (each channel 8 × (value − threshold + 0.061), measured at three thresholds and two radii); Composite Original's labels are swapped against After Effects (EffectCraft's On Top adds the glow over the original, which After Effects calls Behind); Motion Tile output size (#369) |
 | Text | 2 | 2 | — |
 | Time | 8 | 8 | #535 (Pixel Motion Blur, Vector Detail) is closed |
-| Transition | 17 | 17 | — |
+| Transition | 17 | 17 | Venetian Blinds matches After Effects 2026 renders (band phase from the layer centre, Gaussian feather on both edges) except within ~6 px of the layer edge (up to 48/255); Radial Wipe's Feather matches After Effects 2026 (a Gaussian of σ = 0.4 × Feather pixels on both edges of the wedge) |
 | Utility | 9 | 7 | — |
 
 Third-party bundles in After Effects (Cineware, Mocha AE) are out of scope; Keylight is
@@ -64,6 +64,13 @@ the GPU is performance, not parity.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-19 | minor | Glow (original colours): bright pass per channel, 8 × (value − threshold + 0.061), measured against After Effects 2026 (CPU and GPU) |
+| 2026-10-19 | minor | Glow (colour channels): the glow covers the layer's blurred alpha, blur σ = 0.384 × radius, measured against After Effects 2026 renders (CPU and GPU) |
+| 2026-10-19 | minor | Radial Blur repeats the edge instead of sampling transparency outside the layer, measured against After Effects 2026 renders (CPU; Radial Blur has no GPU path) |
+| 2026-10-19 | minor | Venetian Blinds: stripes measured from the layer centre, both band edges Gaussian (σ = Feather / 2), measured against After Effects 2026 (CPU and GPU) |
+| 2026-10-19 | minor | Radial Wipe: Feather is in pixels on both edges of the wiped wedge (was degrees on the moving edge only), measured against After Effects 2026 (CPU and GPU) |
+| 2026-10-19 | minor | Fractal / Turbulent Noise: lattice cell = Scale × 2/3 px (Block noise every 66.7 px at Scale 100, as After Effects 2026), CPU and GPU |
+| 2026-10-19 | minor | Transform: After Effects' skew order and output beyond the layer bounds, measured against After Effects 2026 renders of three cases (CPU and GPU) |
 | 2026-10-19 | minor | Tritone uses Rec. 601 luminance, measured against After Effects 2026 renders of a red solid and a grey ramp (CPU and GPU) |
 | 2026-10-19 | minor | Black & White's Tint keeps the gray's luminosity (Color blend), measured against After Effects 2026 renders (CPU and GPU) |
 | 2026-10-19 | minor | Levels: "Off for 32 bpc Color" no longer clips in 32 bpc projects, unclipped values extrapolate below Output Black; Levels (Individual Controls) applies the channel controls before the RGB ones, measured against After Effects 2026 (CPU and GPU) |
diff --git a/docs/plugins.md b/docs/plugins.md
index a688a89b0..c070e3d98 100644
--- a/docs/plugins.md
+++ b/docs/plugins.md
@@ -14,6 +14,7 @@ Guide):
 | Effect plug-ins (C/C++ SDK, `.aex` / `.plugin`) | [Effect plug-ins](#effect-plug-ins): WebAssembly modules (plug-in API v1) or Rust; the `Plug-ins` folder next to the settings loads at start-up | Different ABI: After Effects SDK plug-ins can't run (G8) |
 | Scripts folder: its scripts are listed in File ▸ Scripts | `Scripts/` in the settings folder (File ▸ Scripts ▸ Install Script File… copies a script there), listed in File ▸ Scripts with the bundled samples | Same |
 | File ▸ Scripts ▸ Run Script File… (`.jsx`, `.jsxbin`) | `.jsx` / `.js` | Gap: `.jsxbin` (an undocumented binary encoding) |
+| File ▸ Scripts ▸ Recent Script Files: the 10 most recently run scripts; Cmd+Option+Shift+D (Ctrl+Alt+Shift+D on Windows) reruns one | File ▸ Scripts ▸ Recent Script Files lists the 10 scripts run last (script files and File ▸ Scripts entries, newest first, kept in the settings); Cmd+Alt+Shift+D runs the most recent one again (`file.runScript {"recent": 0}`, a key that can be changed in Edit ▸ Keyboard Shortcuts) | Same |
 | ExtendScript preprocessor directives (`#include`, `#target`, `#targetengine`) | `#include` / `//@include` / `#includepath` inline files relative to the script (once each, depth-limited, file gate applies); `#target`, `#targetengine`, `#strict` are ignored | Same |
 | `Scripts/Startup` and `Scripts/Shutdown`: run in alphabetical order when the app starts and quits | Not run | Gap |
 | `Scripts/ScriptUI Panels`: listed at the bottom of the Window menu, dockable like the app's own panels, `this` is the panel | `Scripts/ScriptUI Panels/` in the settings folder (File ▸ Scripts ▸ Install ScriptUI Panel… copies one there), listed at the bottom of the Window menu, docked like any panel, `this` is the panel; the panels open when the app quits open again at the next launch | Same. Where a panel was docked isn't kept: workspace layouts aren't saved between launches |
diff --git a/docs/releasing.md b/docs/releasing.md
index bd28d8ec3..07d988b5c 100644
--- a/docs/releasing.md
+++ b/docs/releasing.md
@@ -71,7 +71,7 @@ The MSI's setup wizard ([`installer-ui.wxs`](../packaging/windows/installer-ui.w
 choose the install folder; upgrades and repairs reuse it, and `INSTALLFOLDER="..."` picks it for a
 silent (`/qn`) install. [`packaging-lint.yml`](../.github/workflows/packaging-lint.yml) install-tests
 that with stub binaries ([`test-msi.ps1`](../packaging/windows/test-msi.ps1)): a custom folder,
-an upgrade that keeps it, a repair, uninstall, and the Program Files default. The wizard pages
+an upgrade that keeps it, a repair, uninstall, and the all-users default folder (`Program Files\ArtCraft\EffectCraft`). The wizard pages
 themselves are checked by hand.
 
 The portable zip ships [`portable.txt`](../packaging/windows/portable.txt) beside `effectcraft.exe`.
diff --git a/docs/scripting-parity.md b/docs/scripting-parity.md
index 7ef7e9080..5997a8bd1 100644
--- a/docs/scripting-parity.md
+++ b/docs/scripting-parity.md
@@ -27,6 +27,7 @@ our own scripts; no real-world script library has been run against both apps.
 | `#include`, `#target` directives | yes | `#include` / `//@include` / `#includepath` inline files relative to the including script (once each, nested at most 32 deep, under the scripts' file gate; errors name the included file and line); `#target`, `#targetengine`, `#strict` are ignored | good | `tests_include.rs` (#759); installed scripts and panels have no folder of their own, so they include from the project's folder or absolute paths |
 | `.jsxbin` | yes | no | out of scope | No public specification |
 | Keyboard shortcuts for scripts | yes | no | missing | plugins.md |
+| Recent Script Files | File ▸ Scripts ▸ Recent Script Files (10 scripts), a key to rerun | Same list, kept in the settings; Cmd+Alt+Shift+D reruns the most recent script | same | `recent_script_files_run_again` ([plugins.md](plugins.md)) |
 | Command-line rendering `aerender` | yes | `effectcraft-cli render`, `script`, `exec` | same purpose | `apps/effectcraft-cli` |
 | Essential Graphics scripting hooks | `addToMotionGraphicsTemplate…` | yes (M13.7) | good | — |
 | Agent control (MCP, control channel, every command) | none | yes | beyond | [agents.md](agents.md), [control-protocol.md](control-protocol.md); `list_effects` omits parameter types and ranges (#441) |
diff --git a/packaging/freebsd/package.sh b/packaging/freebsd/package.sh
index b5d1dc447..053f8185c 100755
--- a/packaging/freebsd/package.sh
+++ b/packaging/freebsd/package.sh
@@ -1,12 +1,12 @@
 #!/usr/bin/env bash
 # Build and package EffectCraft for FreeBSD:
 #
-#   $DIST/effectcraft-<version>-freebsd-x86_64.tar.gz   a /usr/local-style tree:
-#       effectcraft-<version>-freebsd-x86_64/{bin, share/applications, share/icons, share/mime,
+#   $DIST/effectcraft-<version>-freebsd-<arch>.tar.gz   a /usr/local-style tree (<arch> is x86_64 or aarch64):
+#       effectcraft-<version>-freebsd-<arch>/{bin, share/applications, share/icons, share/mime,
 #       share/metainfo, share/doc/effectcraft}
 #
 # Install by copying the tree's contents into /usr/local:
-#   tar -xzf effectcraft-<version>-freebsd-x86_64.tar.gz --strip-components 1 -C /usr/local
+#   tar -xzf effectcraft-<version>-freebsd-<arch>.tar.gz --strip-components 1 -C /usr/local
 #
 # Usage: packaging/freebsd/package.sh [--skip-build] [--dry-run]
 #   --dry-run   stage the tree from stub binaries and list it, without building (works on any OS)
@@ -29,13 +29,22 @@ while [[ $# -gt 0 ]]; do
   esac
 done
 
-# FreeBSD's uname says amd64; release file names use x86_64 like the Linux and Windows ones.
-MACHINE="$(uname -m)"
-case "$MACHINE" in
-  amd64 | x86_64) ARCH=x86_64 ;;
-  arm64 | aarch64) ARCH=aarch64 ;;
-  *) echo "unsupported architecture $MACHINE" >&2; exit 2 ;;
-esac
+# A cross build runs on the x86_64 VM, so the target names the arch, not uname.
+if [[ -n "${CARGO_BUILD_TARGET:-}" ]]; then
+  case "$CARGO_BUILD_TARGET" in
+    aarch64-unknown-freebsd) ARCH=aarch64 ;;
+    x86_64-unknown-freebsd) ARCH=x86_64 ;;
+    *) echo "unsupported CARGO_BUILD_TARGET $CARGO_BUILD_TARGET (use x86_64- or aarch64-unknown-freebsd)" >&2; exit 2 ;;
+  esac
+else
+  # FreeBSD's uname says amd64; release file names use x86_64 like the Linux and Windows ones.
+  MACHINE="$(uname -m)"
+  case "$MACHINE" in
+    amd64 | x86_64) ARCH=x86_64 ;;
+    arm64 | aarch64) ARCH=aarch64 ;;
+    *) echo "unsupported architecture $MACHINE" >&2; exit 2 ;;
+  esac
+fi
 if [[ "$DRY_RUN" = 0 ]] && [[ "$(uname -s)" != FreeBSD ]]; then
   echo "error: build on FreeBSD (or pass --dry-run to check the tree layout)" >&2
   exit 2
@@ -46,16 +55,15 @@ echo "==> EffectCraft $VERSION for FreeBSD $ARCH"
 
 # The release VM has 12 GB; full parallelism on the biggest crates runs it out of memory.
 export CARGO_BUILD_JOBS="${CARGO_BUILD_JOBS:-4}"
-# The aarch64 release VM is emulated (no rustup toolchain for this tier-3 target, so it builds
-# natively under QEMU). With one codegen unit and thin LTO the largest crates each optimize on a
-# single emulated core and the job runs past its 5-hour limit, so trade a little runtime speed for
-# parallel codegen there. x86_64 keeps the workspace's release profile.
+# The aarch64 build once ran in an emulated VM: with one codegen unit and thin LTO the largest
+# crates each optimized on a single emulated core and the job ran past its 5-hour limit, so trade
+# a little runtime speed for parallel codegen there. x86_64 keeps the workspace's release profile.
 if [[ "$ARCH" = aarch64 ]]; then
   export CARGO_PROFILE_RELEASE_CODEGEN_UNITS="${CARGO_PROFILE_RELEASE_CODEGEN_UNITS:-16}"
   export CARGO_PROFILE_RELEASE_LTO="${CARGO_PROFILE_RELEASE_LTO:-off}"
 fi
 if [[ "$SKIP_BUILD" = 0 ]]; then
-  (cd "$ROOT" && cargo build --release --locked -p effectcraft -p effectcraft-cli)
+  (cd "$ROOT" && cargo build --release --locked ${CARGO_BUILD_TARGET:+--target "$CARGO_BUILD_TARGET"} -p effectcraft -p effectcraft-cli)
 fi
 WORK="$CARGO_TARGET_DIR/freebsd-package"
 STAGE="$WORK/$BASENAME"
@@ -63,6 +71,7 @@ rm -rf "$WORK"
 mkdir -p "$WORK"
 
 BIN="$CARGO_TARGET_DIR/release"
+if [[ -n "${CARGO_BUILD_TARGET:-}" ]]; then BIN="$CARGO_TARGET_DIR/$CARGO_BUILD_TARGET/release"; fi
 OUT_DIR="$DIST"
 if [[ "$DRY_RUN" = 1 ]]; then
   # Stub binaries, and the tarball stays in the work dir so dist/ only ever holds real builds.
@@ -103,7 +112,15 @@ mkdir -p "$OUT_DIR"
 tar -C "$WORK" -czf "$OUT_DIR/$BASENAME.tar.gz" "$BASENAME"
 echo "wrote $OUT_DIR/$BASENAME.tar.gz"
 
-"$STAGE/bin/effectcraft-cli" --version
+# Run the smoke test only when the binary's target is this host's (a cross build can't run here).
+case "$(uname -m)" in
+  amd64 | x86_64) HOST_TRIPLE=x86_64-unknown-freebsd ;;
+  arm64 | aarch64) HOST_TRIPLE=aarch64-unknown-freebsd ;;
+  *) HOST_TRIPLE= ;;
+esac
+if [[ -z "${CARGO_BUILD_TARGET:-}" || "$CARGO_BUILD_TARGET" = "$HOST_TRIPLE" ]]; then
+  "$STAGE/bin/effectcraft-cli" --version
+fi
 if [[ "$DRY_RUN" = 1 ]]; then
   echo "==> dry run: tarball contents"
   tar -tzvf "$OUT_DIR/$BASENAME.tar.gz"
diff --git a/packaging/macos/package.sh b/packaging/macos/package.sh
index 6afc9a328..be0c03aae 100755
--- a/packaging/macos/package.sh
+++ b/packaging/macos/package.sh
@@ -80,6 +80,21 @@ sign() {
   codesign --force --sign "$IDENTITY" ${kc[@]+"${kc[@]}"} "${ts[@]}" "$@"
 }
 
+# `stapler staple` and `stapler validate` both fetch the ticket from Apple's CloudKit, and a dropped
+# connection there (NSURLErrorDomain -1005, "Error 68") fails them although notarization worked.
+# Both are idempotent, so retry with a pause; a missing or bad ticket still fails every try.
+stapler_retry() {
+  local try
+  for try in 1 2 3 4; do
+    xcrun stapler "$1" "$2" && return 0
+    [[ "$try" = 4 ]] && break
+    echo "stapler $1 failed (try $try of 4); retrying in $((try * 20)) s" >&2
+    sleep $((try * 20))
+  done
+  echo "error: stapler $1 $(basename "$2") failed 4 times" >&2
+  exit 1
+}
+
 notarize() {
   local file="$1" out id status
   echo "==> notarizing $(basename "$file") (this can take a few minutes)"
@@ -120,8 +135,8 @@ codesign --verify --strict --deep --verbose=2 "$APP"
 if [[ "$NOTARIZE" = 1 ]]; then
   ditto -c -k --keepParent "$APP" "$WORK/EffectCraft-notarize.zip"
   notarize "$WORK/EffectCraft-notarize.zip"
-  xcrun stapler staple "$APP"
-  xcrun stapler validate "$APP"
+  stapler_retry staple "$APP"
+  stapler_retry validate "$APP"
   spctl --assess --type execute -vvv "$APP"
 fi
 
@@ -182,8 +197,8 @@ fi
 hdiutil_retry detach detach "$MOUNT" >/dev/null
 if [[ "$NOTARIZE" = 1 ]]; then
   notarize "$DMG"
-  xcrun stapler staple "$DMG"
-  xcrun stapler validate "$DMG"
+  stapler_retry staple "$DMG"
+  stapler_retry validate "$DMG"
   spctl --assess --type open --context context:primary-signature -vvv "$DMG"
 fi
 
diff --git a/packaging/windows/INSTALLATION.md b/packaging/windows/INSTALLATION.md
new file mode 100644
index 000000000..982a5b420
--- /dev/null
+++ b/packaging/windows/INSTALLATION.md
@@ -0,0 +1,35 @@
+# Windows installation policy checks
+
+New installations default to the current account under `Programs\ArtCraft\<App>`.
+The first setup page offers installation for everyone. Scope is selected before duplicate
+checks and directory costing. An update uses the existing context's remembered exact folder;
+`INSTALLFOLDER` supplied explicitly is never replaced. It is a secure MSI property so the
+chosen folder reaches the elevated installer. Silent machine updates pass `ALLUSERS=1`.
+A cross-context copy is refused; changing context means uninstalling the old copy first.
+
+App registration follows the selected context. Existing optional shortcuts and file-handler
+choices stay app-owned. No new cleanup operation or model/settings migration is introduced.
+Packaged resources remain package-owned; separately downloaded shared models are not caches
+and are outside this installer's ownership.
+
+## Repeatable metadata tests
+
+On Windows with WiX 5.0.2 and its matching UI/Util extensions:
+
+```powershell
+./packaging/windows/test-install-policy.ps1 -OutputDirectory ./target/install-policy-tests
+```
+
+The script builds x64, x86 and arm64 packages with deliberately non-executable payloads. It
+uses the actual package source and compiled database. A safe Windows Installer session checks
+24 scope/registration/maintenance cases, remembered and explicit custom folders, sequencing,
+upgrade identity and the original registration inventory recorded in `install-policy.json`.
+The release packaging script runs the compiled checker before signing. Packaging CI runs the
+small fixture builds without compiling the Rust application.
+
+Never install or distribute the `NOT-INSTALLABLE.msi` fixtures as an app. Passing these checks
+does not prove real installation, elevation, legacy-version upgrades, registry writes, optional
+shortcut/menu behaviour, cancellation, rollback or uninstall. Those still require the real
+payload in an authorised clean Windows test environment. Cross-architecture metadata is not
+execution evidence on those architectures. Existing open installer/association PRs must be
+reconciled before publication. Nothing here changes macOS/Linux native packaging conventions.
diff --git a/packaging/windows/check-install-policy.ps1 b/packaging/windows/check-install-policy.ps1
new file mode 100644
index 000000000..5463c0083
--- /dev/null
+++ b/packaging/windows/check-install-policy.ps1
@@ -0,0 +1,370 @@
+<#
+.SYNOPSIS
+  Check the compiled installation policy without installing any product.
+.DESCRIPTION
+  Uses Windows Installer's safe session (OpenPackage option 1). Only property-setting custom
+  actions are exercised. No AppSearch, install, repair, removal or file-writing action runs.
+#>
+param([Parameter(Mandatory = $true)] [string] $MsiPath)
+$ErrorActionPreference = 'Stop'
+Set-StrictMode -Version Latest
+$policy = Get-Content -Raw -LiteralPath (Join-Path $PSScriptRoot 'install-policy.json') | ConvertFrom-Json
+function Read-Rows($Database, [string] $Sql, [int] $Columns) {
+  $view = $Database.OpenView($Sql)
+  try {
+    [void]$view.Execute()
+    while ($null -ne ($record = $view.Fetch())) {
+      try {
+        $values = @(for ($i = 1; $i -le $Columns; $i++) {
+          $record.GetType().InvokeMember('StringData', 'GetProperty', $null, $record, @($i))
+        })
+        ,$values
+      } finally { [void][Runtime.InteropServices.Marshal]::FinalReleaseComObject($record) }
+    }
+  } finally {
+    [void]$view.Close()
+    [void][Runtime.InteropServices.Marshal]::FinalReleaseComObject($view)
+  }
+}
+function Set-SessionProperty($Session, [string] $Name, [string] $Value) {
+  [void]$Session.GetType().InvokeMember('Property', 'SetProperty', $null, $Session, @($Name, $Value))
+}
+function Get-SessionProperty($Session, [string] $Name) {
+  $Session.GetType().InvokeMember('Property', 'GetProperty', $null, $Session, @($Name))
+}
+function Get-PackageTemplate($Database) {
+  # Summary information property 7 is the platform: "Intel;1033", "x64;1033" or "Arm64;1033".
+  $summary = $Database.GetType().InvokeMember('SummaryInformation', 'GetProperty', $null, $Database, @(0))
+  try { [string]$summary.GetType().InvokeMember('Property', 'GetProperty', $null, $summary, @(7)) }
+  finally { [void][Runtime.InteropServices.Marshal]::FinalReleaseComObject($summary) }
+}
+$installer = $null; $database = $null; $session = $null
+try {
+  $installer = New-Object -ComObject WindowsInstaller.Installer
+  $file = (Resolve-Path -LiteralPath $MsiPath).Path
+  $database = $installer.OpenDatabase($file, 0)
+  $session = $installer.OpenPackage($file, 1)
+  $properties = @{}
+  foreach ($row in (Read-Rows $database 'SELECT `Property`, `Value` FROM `Property`' 2)) { $properties[$row[0]] = $row[1] }
+  $secureProperties = @($properties['SecureCustomProperties'] -split ';')
+  if ('INSTALLFOLDER' -notin $secureProperties) {
+    throw 'The selected installation folder must survive elevation (secure INSTALLFOLDER).'
+  }
+  if ($policy.mode -eq 'perUser') {
+    if ($properties.ContainsKey('ALLUSERS')) { throw 'Launcher must remain per-user; machine self-update is not part of this change.' }
+    if ($properties['UpgradeCode'].Trim('{}') -ne $policy.upgradeCode) { throw 'Launcher upgrade identity changed.' }
+    $dirs = @{}
+    foreach ($row in (Read-Rows $database 'SELECT `Directory`, `Directory_Parent`, `DefaultDir` FROM `Directory`' 3)) { $dirs[$row[0]] = @($row[1],$row[2]) }
+    if ($dirs['INSTALLFOLDER'][0] -ne 'CraftSuiteFolder' -or $dirs['CraftSuiteFolder'][1] -ne 'ArtCraft' -or
+        $dirs['CraftSuiteFolder'][0] -ne 'LocalProgramsFolder' -or $dirs['LocalProgramsFolder'][0] -ne 'LocalAppDataFolder') {
+      throw 'Launcher new-install folder must be under the per-user ArtCraft suite root.'
+    }
+    foreach ($explicit in @('', 'F:\Chosen exact launcher')) {
+      Set-SessionProperty $session 'PREVIOUSINSTALLFOLDER' 'E:\Existing exact launcher'
+      Set-SessionProperty $session 'INSTALLFOLDER' $explicit
+      $row = @(Read-Rows $database 'SELECT `Condition` FROM `InstallUISequence` WHERE `Action` = ''CraftRestoreLauncherFolder''' 1)[0]
+      if ($session.EvaluateCondition($row[0]) -eq 1) {
+        if ($session.DoAction('CraftRestoreLauncherFolder') -ne 1) { throw 'Launcher restore action failed.' }
+      }
+      $expected = if ($explicit) { $explicit } else { 'E:\Existing exact launcher' }
+      if ((Get-SessionProperty $session 'INSTALLFOLDER') -ne $expected) { throw 'Launcher custom or existing path was lost.' }
+    }
+    $rows = @(Read-Rows $database 'SELECT `Root`, `Key`, `Name`, `Value` FROM `Registry`' 4)
+    if (@($rows | Where-Object { $_[0] -ne '1' }).Count) { throw 'Launcher registration must stay under the current account.' }
+    foreach ($entry in $policy.registry) {
+      if (@($rows | Where-Object { $_[0] -eq $entry[0] -and $_[1] -eq $entry[1] -and $_[2] -eq $entry[2] -and $_[3] -eq $entry[3] }).Count -ne 1) {
+        throw 'Launcher registration or shortcut preference changed unexpectedly.'
+      }
+    }
+    Write-Output 'PASS ArtCraft Launcher: per-user scope, suite folder, remembered/custom paths and existing registration. No installation performed.'
+    return
+  }
+  if ($properties['ALLUSERS'] -ne '2' -or $properties['MSIINSTALLPERUSER'] -ne '1') {
+    throw 'Policy regression: new packages must default to the per-user dual-scope context.'
+  }
+  if ($properties['UpgradeCode'].Trim('{}') -ne $policy.upgradeCode) { throw 'The existing upgrade identity must not change.' }
+  $directories = @{}
+  foreach ($row in (Read-Rows $database 'SELECT `Directory`, `Directory_Parent`, `DefaultDir` FROM `Directory`' 3)) {
+    $directories[$row[0]] = @($row[1], $row[2])
+  }
+  if ($directories['INSTALLFOLDER'][0] -ne 'CraftSuiteFolder' -or
+      $directories['CraftSuiteFolder'][1] -ne 'ArtCraft') { throw 'Expected the app under the ArtCraft suite folder.' }
+  $programs = $directories['CraftSuiteFolder'][0]
+  if ($programs -eq 'ProgramFiles6432Folder') { $programs = $directories[$programs][0] }
+  if ($programs -notin 'ProgramFilesFolder', 'ProgramFiles64Folder') {
+    throw 'Use Windows Installer native folder redirection, not a hard-coded profile path.'
+  }
+  $guards = @(Read-Rows $database 'SELECT `Condition`, `Description` FROM `LaunchCondition`' 2 |
+    Where-Object { $_[0] -match 'CRAFT_(USER|MACHINE)_DIR' })
+  if ($guards.Count -ne 2) { throw 'Expected both duplicate-installation guards.' }
+  $cases = 0
+  foreach ($scope in @('', '2', '1')) {
+    foreach ($user in @('', 'D:\Existing user app')) {
+      foreach ($machine in @('', 'E:\Existing machine app')) {
+        foreach ($installed in @('', '1')) {
+          Set-SessionProperty $session 'ALLUSERS' $scope
+          Set-SessionProperty $session 'Installed' $installed
+          Set-SessionProperty $session 'CRAFT_USER_DIR' $user
+          Set-SessionProperty $session 'CRAFT_MACHINE_DIR' $machine
+          $allowed = $true
+          foreach ($guard in $guards) {
+            $value = $session.EvaluateCondition($guard[0])
+            if ($value -notin 0, 1) { throw 'Invalid duplicate guard.' }
+            if ($value -eq 0) { $allowed = $false }
+          }
+          $opposite = if ($scope -eq '1') { $user } else { $machine }
+          $expected = [bool]$installed -or -not [bool]$opposite
+          if ($allowed -ne $expected) { throw "Scope regression: ALLUSERS='$scope', user=$([bool]$user), machine=$([bool]$machine), maintenance=$([bool]$installed)." }
+          $cases++
+        }
+      }
+    }
+  }
+  # Execute the actual authored type-51 actions in a safe session, not copied resolver logic.
+  foreach ($scope in @('', '2', '1')) {
+    foreach ($explicit in @('', 'F:\Chosen exact app')) {
+      Set-SessionProperty $session 'ALLUSERS' $scope
+      Set-SessionProperty $session 'INSTALLFOLDER' $explicit
+      Set-SessionProperty $session 'CRAFT_USER_DIR' 'D:\Existing user app'
+      Set-SessionProperty $session 'CRAFT_MACHINE_DIR' 'E:\Existing machine app'
+      $action = if ($scope -eq '1') { 'CraftRestoreMachineFolder' } else { 'CraftRestoreUserFolder' }
+      # Evaluate the compiled condition, so the test exercises it instead of calling the action directly.
+      $restore = @(Read-Rows $database ('SELECT `Condition` FROM `InstallExecuteSequence` WHERE `Action` = ''{0}''' -f $action) 1)[0]
+      $selected = $session.EvaluateCondition($restore[0]) -eq 1
+      if ($selected -eq [bool]$explicit) { throw "$action must run only when no folder was supplied (condition: $($restore[0]))." }
+      if ($selected -and $session.DoAction($action) -ne 1) { throw 'Remembered-folder property action failed.' }
+      $expected = if ($explicit) { $explicit } elseif ($scope -eq '1') { 'E:\Existing machine app' } else { 'D:\Existing user app' }
+      if ((Get-SessionProperty $session 'INSTALLFOLDER') -ne $expected) { throw 'Custom or remembered folder was not preserved.' }
+    }
+  }
+  $ui = @{}
+  foreach ($row in (Read-Rows $database 'SELECT `Action`, `Sequence` FROM `InstallUISequence`' 2)) { $ui[$row[0]] = [int]$row[1] }
+  if (-not ($ui['AppSearch'] -lt $ui['CraftPreferMachineScope'] -and
+      $ui['CraftPreferMachineScope'] -lt $ui['CraftScopeDlg'] -and
+      $ui['CraftScopeDlg'] -lt $ui['FindRelatedProducts'] -and
+      $ui['FindRelatedProducts'] -lt $ui['LaunchConditions'] -and
+      $ui['CraftScopeDlg'] -lt $ui['CraftRestoreUserFolder'] -and $ui['CraftRestoreUserFolder'] -lt $ui['CostInitialize'] -and
+      $ui['CraftScopeDlg'] -lt $ui['CraftRestoreMachineFolder'] -and $ui['CraftRestoreMachineFolder'] -lt $ui['CostInitialize'])) {
+    throw 'Scope must be chosen after AppSearch and before FindRelatedProducts, launch checks and costing.'
+  }
+  # Windows Installer resolves Program Files for the context it started in, before the wizard's scope choice.
+  # The wizard therefore sets the new-install folder itself, and only in the wizard.
+  $defaults = @(Read-Rows $database 'SELECT `Action`, `Sequence`, `Condition` FROM `InstallUISequence`' 3 | Where-Object { $_[0] -like 'CraftDefault*' })
+  if ($defaults.Count -lt 2) { throw 'The wizard must set the new-install folder after the scope page; Program Files is resolved before the choice.' }
+  foreach ($row in $defaults) {
+    if (-not ($ui['CraftScopeDlg'] -lt [int]$row[1] -and [int]$row[1] -lt $ui['CostInitialize'])) { throw "$($row[0]) must run after the scope page and before costing." }
+  }
+  if (@(Read-Rows $database 'SELECT `Action` FROM `InstallExecuteSequence`' 1 | Where-Object { $_[0] -like 'CraftDefault*' }).Count) {
+    throw 'Silent installs must not use the wizard-only default folder actions.'
+  }
+  # The machine default comes from the environment of the package architecture, not from a folder name.
+  # x86 packages use Program Files (x86) on 64-bit Windows; x64 and Arm64 packages use the 64-bit root.
+  $machineRoot = if ((Get-PackageTemplate $database) -match '^Intel') {
+    if (Get-SessionProperty $session 'VersionNT64') { ${env:ProgramFiles(x86)} } else { $env:ProgramFiles }
+  } elseif ($env:ProgramW6432) { $env:ProgramW6432 } else { $env:ProgramFiles }
+  $machineFolder = (Join-Path $machineRoot "ArtCraft\$($policy.name)") + '\'
+  foreach ($scope in @('1', '')) {
+    Set-SessionProperty $session 'ALLUSERS' $scope
+    Set-SessionProperty $session 'INSTALLFOLDER' ''
+    Set-SessionProperty $session 'CRAFT_MACHINE_DIR' ''
+    Set-SessionProperty $session 'CRAFT_USER_DIR' ''
+    foreach ($row in @($defaults | Sort-Object { [int]$_[1] })) {
+      if ($session.EvaluateCondition($row[2]) -eq 1 -and $session.DoAction($row[0]) -ne 1) { throw "$($row[0]) failed." }
+    }
+    $folder = Get-SessionProperty $session 'INSTALLFOLDER'
+    $wanted = if ($scope -eq '1') { $machineFolder } else { (Join-Path $env:LOCALAPPDATA "Programs\ArtCraft\$($policy.name)") + '\' }
+    if ($folder -ine $wanted) { throw "Wizard default folder for ALLUSERS='$scope' is '$folder', expected '$wanted'." }
+  }
+  # Replay the wizard's compiled folder actions in sequence order, as the full UI runs them. A remembered
+  # folder must win over the new-install default, and a folder the user typed must survive both.
+  $uiFolderActions = @(Read-Rows $database 'SELECT `Action`, `Sequence`, `Condition` FROM `InstallUISequence`' 3 |
+    Where-Object { $_[0] -match '^Craft(Restore|Default)' } | Sort-Object { [int]$_[1] })
+  $userDefault = (Join-Path $env:LOCALAPPDATA "Programs\ArtCraft\$($policy.name)") + '\'
+  foreach ($case in @(
+      @('1', 'D:\Remembered user app', 'E:\Remembered machine app', '', 'E:\Remembered machine app'),
+      @('', 'D:\Remembered user app', 'E:\Remembered machine app', '', 'D:\Remembered user app'),
+      @('1', '', '', '', $machineFolder),
+      @('', '', '', '', $userDefault),
+      @('1', 'D:\Remembered user app', 'E:\Remembered machine app', 'F:\Chosen exact app', 'F:\Chosen exact app'))) {
+    Set-SessionProperty $session 'Installed' ''
+    Set-SessionProperty $session 'ALLUSERS' $case[0]
+    Set-SessionProperty $session 'CRAFT_USER_DIR' $case[1]
+    Set-SessionProperty $session 'CRAFT_MACHINE_DIR' $case[2]
+    Set-SessionProperty $session 'INSTALLFOLDER' $case[3]
+    foreach ($row in $uiFolderActions) {
+      if ($session.EvaluateCondition($row[2]) -eq 1 -and $session.DoAction($row[0]) -ne 1) { throw "$($row[0]) failed." }
+    }
+    $folder = Get-SessionProperty $session 'INSTALLFOLDER'
+    if ($folder -ine $case[4]) { throw "Full-UI folder for ALLUSERS='$($case[0])' is '$folder', expected '$($case[4])'." }
+  }
+  $execute = @{}
+  foreach ($row in (Read-Rows $database 'SELECT `Action`, `Sequence` FROM `InstallExecuteSequence`' 2)) { $execute[$row[0]] = [int]$row[1] }
+  foreach ($action in @('CraftRestoreUserFolder','CraftRestoreMachineFolder')) {
+    if (-not ($execute['AppSearch'] -lt $execute[$action] -and $execute[$action] -lt $execute['CostInitialize'])) {
+      throw 'Silent updates must restore the folder before directory costing.'
+    }
+  }
+  foreach ($resolver in @('CraftUFromLegacyExe','CraftMFromLegacyExe')) {
+    if (-not ($execute['AppSearch'] -lt $execute[$resolver] -and $execute[$resolver] -lt $execute['LaunchConditions'])) {
+      throw 'Both legacy folder resolvers must run after AppSearch and before the launch checks.'
+    }
+  }
+  # AppSearch itself never runs in this safe session, so check the compiled searches and then run the
+  # property actions that turn the search results into the remembered folder, once per scope.
+  $appSearch = @{}
+  foreach ($row in (Read-Rows $database 'SELECT `Property`, `Signature_` FROM `AppSearch`' 2)) { $appSearch[$row[0]] = $row[1] }
+  $locators = @{}
+  foreach ($row in (Read-Rows $database 'SELECT `Signature_`, `Root`, `Key`, `Name`, `Type` FROM `RegLocator`' 5)) { $locators[$row[0]] = $row }
+  $appPaths = '^Software\\Microsoft\\Windows\\CurrentVersion\\App Paths\\[^\\]+\.exe$'
+  # Suffix, how to match the key, key, value name, locator type (2 = raw value, 1 = file; the 64-bit flag is masked off).
+  $searchContract = @(
+    @('DIR',       'exact', "Software\$($policy.name)", 'InstallDir',    '2'),
+    @('FOLDER',    'exact', "Software\$($policy.name)", 'InstallFolder', '2'),
+    @('PATH',      'regex', $appPaths,                  'Path',          '2'),
+    @('EXEFOLDER', 'regex', $appPaths,                  '',              '1'),
+    @('EXE',       'regex', $appPaths,                  '',              '1'))
+  $resolverCases = @(
+    @{ name = 'every record, DIR wins';        dir = 'D:\Dir\'; folder = 'D:\Folder\'; path = 'D:\Path\'; exeFolder = 'D:\Exe\'; exe = 'D:\Exe\app.exe'; existing = '';            expected = 'D:\Dir\' },
+    @{ name = 'FOLDER wins without DIR';       dir = '';        folder = 'D:\Folder\'; path = 'D:\Path\'; exeFolder = 'D:\Exe\'; exe = 'D:\Exe\app.exe'; existing = '';            expected = 'D:\Folder\' },
+    @{ name = 'PATH wins without DIR, FOLDER'; dir = '';        folder = '';           path = 'D:\Path\'; exeFolder = 'D:\Exe\'; exe = 'D:\Exe\app.exe'; existing = '';            expected = 'D:\Path\' },
+    @{ name = 'legacy exe folder is last';     dir = '';        folder = '';           path = '';         exeFolder = 'D:\Exe\'; exe = 'D:\Exe\app.exe'; existing = '';            expected = 'D:\Exe\' },
+    @{ name = 'legacy folder needs the exe';   dir = '';        folder = '';           path = '';         exeFolder = 'D:\Exe\'; exe = '';               existing = '';            expected = '' },
+    @{ name = 'a preset folder is kept';       dir = 'D:\Dir\'; folder = 'D:\Folder\'; path = 'D:\Path\'; exeFolder = 'D:\Exe\'; exe = 'D:\Exe\app.exe'; existing = 'P:\Preset\'; expected = 'P:\Preset\' })
+  foreach ($scopeSpec in @(@('U', '1', 'CRAFT_USER_DIR'), @('M', '2', 'CRAFT_MACHINE_DIR'))) {
+    $letter = $scopeSpec[0]; $target = $scopeSpec[2]
+    foreach ($item in $searchContract) {
+      $property = "CRAFT_${letter}_$($item[0])"
+      $locator = if ($appSearch.ContainsKey($property)) { $locators[$appSearch[$property]] } else { $null }
+      $keyOk = $null -ne $locator -and $(if ($item[1] -eq 'exact') { $locator[2] -eq $item[2] } else { $locator[2] -match $item[2] })
+      if (-not $keyOk -or $locator[1] -ne $scopeSpec[1] -or $locator[3] -ne $item[3] -or ([int]$locator[4] -band 3) -ne [int]$item[4]) {
+        throw "Compiled search for $property is missing or points at the wrong registry location."
+      }
+    }
+    $chain = @(Read-Rows $database 'SELECT `Action`, `Sequence`, `Condition` FROM `InstallExecuteSequence`' 3 |
+      Where-Object { $_[0] -match "^Craft${letter}From" } | Sort-Object { [int]$_[1] })
+    $order = @($chain | ForEach-Object { $_[0] }) -join ','
+    if ($order -ne "Craft${letter}FromDIR,Craft${letter}FromFOLDER,Craft${letter}FromPATH,Craft${letter}FromLegacyExe") {
+      throw "Remembered-folder resolvers for scope $letter run in the wrong order: $order"
+    }
+    foreach ($case in $resolverCases) {
+      Set-SessionProperty $session $target $case.existing
+      Set-SessionProperty $session "CRAFT_${letter}_DIR" $case.dir
+      Set-SessionProperty $session "CRAFT_${letter}_FOLDER" $case.folder
+      Set-SessionProperty $session "CRAFT_${letter}_PATH" $case.path
+      Set-SessionProperty $session "CRAFT_${letter}_EXEFOLDER" $case.exeFolder
+      Set-SessionProperty $session "CRAFT_${letter}_EXE" $case.exe
+      foreach ($row in $chain) {
+        if ($session.EvaluateCondition($row[2]) -eq 1 -and $session.DoAction($row[0]) -ne 1) { throw "$($row[0]) failed." }
+      }
+      $got = Get-SessionProperty $session $target
+      if ($got -ne $case.expected) { throw "Resolver chain for scope $letter, case '$($case.name)': got '$got', expected '$($case.expected)'." }
+    }
+  }
+  # Switching the first-page choice must reset BOTH properties, including a back-and-forth change.
+  $events = @(Read-Rows $database 'SELECT `Event`, `Argument`, `Condition`, `Ordering` FROM `ControlEvent` WHERE `Dialog_` = ''CraftScopeDlg'' AND `Control_` = ''Next'' ORDER BY `Ordering`' 4)
+  # Model the full-UI upgrade entry with an existing machine-wide copy. Run
+  # the actual preference action, then the compiled Next events before discovery.
+  Set-SessionProperty $session 'ALLUSERS' '2'
+  Set-SessionProperty $session 'CRAFT_SCOPE' 'user'
+  Set-SessionProperty $session 'CRAFT_USER_DIR' ''
+  Set-SessionProperty $session 'CRAFT_MACHINE_DIR' 'E:\Existing machine app'
+  $preference = @(Read-Rows $database 'SELECT `Condition` FROM `InstallUISequence` WHERE `Action` = ''CraftPreferMachineScope''' 1)[0]
+  if ($session.EvaluateCondition($preference[0]) -ne 1 -or $session.DoAction('CraftPreferMachineScope') -ne 1 -or
+      (Get-SessionProperty $session 'CRAFT_SCOPE') -ne 'machine') {
+    throw 'Full-UI machine upgrades must initially select the existing machine context.'
+  }
+  foreach ($choice in @('machine','user','machine','user')) {
+    Set-SessionProperty $session 'CRAFT_SCOPE' $choice
+    foreach ($event in $events) {
+      if ($event[0] -notmatch '^\[([^\]]+)\]$') { continue }
+      $property = $Matches[1]
+      if ($session.EvaluateCondition($event[2]) -eq 1) {
+        Set-SessionProperty $session $property $(if ($event[1] -eq '{}') { '' } else { $event[1] })
+      }
+    }
+    $allUsers = Get-SessionProperty $session 'ALLUSERS'
+    $perUser = Get-SessionProperty $session 'MSIINSTALLPERUSER'
+    if (($choice -eq 'machine' -and ($allUsers -ne '1' -or $perUser)) -or
+        ($choice -eq 'user' -and ($allUsers -or $perUser -ne '1'))) {
+      throw 'Scope selector does not reset the requested installation context.'
+    }
+  }
+  $actions = @(Read-Rows $database 'SELECT `Action`, `Source`, `Target`, `Type` FROM `CustomAction`' 4)
+  $savedOptions = @($actions | Where-Object { $_[0] -match '^CraftLoadOption[0-9]+M$' })
+  foreach ($option in $savedOptions) {
+    if ([int]$option[3] -ne 51) { throw 'Saved-option test may run only property-setting actions.' }
+    $number = [regex]::Match($option[0], '[0-9]+').Value
+    foreach ($scope in @('2','1')) {
+      Set-SessionProperty $session 'ALLUSERS' $scope
+      Set-SessionProperty $session "CRAFT_OPTION_${number}_M" 'saved-machine-choice'
+      Set-SessionProperty $session "CRAFT_OPTION_${number}_U" 'saved-user-choice'
+      Set-SessionProperty $session $option[1] ''
+      $action = "CraftLoadOption$number" + $(if ($scope -eq '1') { 'M' } else { 'U' })
+      if ($session.DoAction($action) -ne 1) { throw 'Saved-option property action failed.' }
+      $expected = if ($scope -eq '1') { 'saved-machine-choice' } else { 'saved-user-choice' }
+      if ((Get-SessionProperty $session $option[1]) -ne $expected) { throw 'Saved installer choices leaked across contexts.' }
+    }
+  }
+  # Follow the compiled control conditions, not the source's intended appearance.
+  $controls = @(Read-Rows $database 'SELECT `Dialog_`, `Control`, `Type`, `Attributes`, `Text` FROM `Control`' 5)
+  $conditions = @()
+  if (@(Read-Rows $database 'SELECT `Name` FROM `_Tables` WHERE `Name` = ''ControlCondition''' 1).Count) {
+    $conditions = @(Read-Rows $database 'SELECT `Dialog_`, `Control_`, `Action`, `Condition` FROM `ControlCondition`' 4)
+  }
+  function Test-ControlVisible($Control) {
+    $visible = ([int]$Control[3] -band 1) -ne 0
+    foreach ($condition in $conditions) {
+      if ($condition[0] -eq $Control[0] -and $condition[1] -eq $Control[1] -and $session.EvaluateCondition($condition[3]) -eq 1) {
+        if ($condition[2] -eq 'Show') { $visible = $true }
+        if ($condition[2] -eq 'Hide') { $visible = $false }
+      }
+    }
+    return $visible
+  }
+  foreach ($button in @($controls | Where-Object { $_[0] -in 'InstallWelcome','InstallMaintenance','DesktopShortcutDlg' -and ([int]$_[3] -band 8388608) -ne 0 })) {
+    $plain = @($controls | Where-Object { $_[0] -eq $button[0] -and $_[1] -eq ($button[1] + 'User') })
+    if ($plain.Count -ne 1 -or ([int]$plain[0][3] -band 8388608)) { throw 'Scope-aware buttons need an unshielded per-user counterpart.' }
+    foreach ($scope in @('', '2', '1')) {
+      Set-SessionProperty $session 'ALLUSERS' $scope
+      if ((Test-ControlVisible $button) -ne ($scope -eq '1') -or (Test-ControlVisible $plain[0]) -ne ($scope -ne '1')) {
+        throw 'The elevation shield must follow the selected scope.'
+      }
+    }
+    $dialog = $button[0]; $shieldId = $button[1]; $plainId = $plain[0][1]
+    $shieldEvents = @(Read-Rows $database "SELECT ``Event``, ``Argument``, ``Condition``, ``Ordering`` FROM ``ControlEvent`` WHERE ``Dialog_`` = '$dialog' AND ``Control_`` = '$shieldId' ORDER BY ``Ordering``" 4 | ForEach-Object { $_ -join '|' })
+    $plainEvents = @(Read-Rows $database "SELECT ``Event``, ``Argument``, ``Condition``, ``Ordering`` FROM ``ControlEvent`` WHERE ``Dialog_`` = '$dialog' AND ``Control_`` = '$plainId' ORDER BY ``Ordering``" 4 | ForEach-Object { $_ -join '|' })
+    if (($shieldEvents -join "`n") -ne ($plainEvents -join "`n")) { throw 'Per-user and machine buttons must perform the same operation.' }
+  }
+  foreach ($scope in @('', '2', '1')) {
+    Set-SessionProperty $session 'ALLUSERS' $scope
+    foreach ($text in @($controls | Where-Object { $_[4] -like '*for all users*' })) {
+      if ((Test-ControlVisible $text) -ne ($scope -eq '1')) { throw 'The welcome-page scope text must follow the selected scope.' }
+    }
+  }
+  if ($policy.id -in 'deckcraft','filmcraft','soundcraft') {
+    foreach ($route in @(@('WelcomeDlg','Next','InstallDirDlg'),@('InstallDirDlg','Back','WelcomeDlg'))) {
+      $dialog = $route[0]; $control = $route[1]
+      $routes = @(Read-Rows $database "SELECT ``Argument``, ``Condition`` FROM ``ControlEvent`` WHERE ``Dialog_`` = '$dialog' AND ``Control_`` = '$control' AND ``Event`` = 'NewDialog' ORDER BY ``Ordering``" 2)
+      Set-SessionProperty $session 'Installed' ''
+      $destination = ''
+      foreach ($event in $routes) { if ($session.EvaluateCondition($event[1]) -eq 1) { $destination = $event[0] } }
+      if ($destination -ne $route[2]) { throw 'Skipping the licence page must work in both navigation directions.' }
+    }
+  }
+  $registry = @(Read-Rows $database 'SELECT `Root`, `Key`, `Name`, `Value` FROM `Registry`' 4)
+  if (@($registry | Where-Object { $_[0] -in '1', '2' }).Count) { throw 'Registration must follow the selected context, not force HKCU or HKLM.' }
+  if (@($registry | Where-Object { $_[0] -eq '0' -and $_[1] -match '^Software\\Classes(\\|$)' }).Count) {
+    throw 'HKCR keys must be relative to Classes.'
+  }
+  foreach ($entry in $policy.registry) {
+    $found = @($registry | Where-Object { $_[0] -eq $entry[0] -and $_[1] -eq $entry[1] -and $_[2] -eq $entry[2] -and $_[3] -eq $entry[3] })
+    if ($found.Count -ne 1) { throw "Lost or changed registration: $($entry[1]) / $($entry[2])" }
+  }
+  $installDir = @($registry | Where-Object { $_[0] -eq '-1' -and $_[1] -eq "Software\$($policy.name)" -and $_[2] -eq 'InstallDir' -and $_[3] -eq '[INSTALLFOLDER]' })
+  if ($installDir.Count -ne 1) { throw 'A context-sensitive installation-folder record is required.' }
+  Write-Output "PASS $($policy.name): $cases scope cases, folder preservation, action sequencing and registry contract. No installation performed."
+} finally {
+  foreach ($com in @($session, $database, $installer)) {
+    if ($null -ne $com) { [void][Runtime.InteropServices.Marshal]::FinalReleaseComObject($com) }
+  }
+}
diff --git a/packaging/windows/effectcraft.wxs b/packaging/windows/effectcraft.wxs
index cc1df639b..f330ca061 100644
--- a/packaging/windows/effectcraft.wxs
+++ b/packaging/windows/effectcraft.wxs
@@ -1,26 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!--
-  EffectCraft MSI (WiX Toolset v5: `dotnet tool install -g wix`). Built by package.ps1:
-
-    wix build effectcraft.wxs installer-ui.wxs -arch x64 -d Version=1.2.3 -d BinDir=... -d IconPath=... -o out.msi
-
-  Per-machine install into Program Files (or a folder the user picks), a Start Menu shortcut and,
-  unless DESKTOPSHORTCUT=0 (the wizard's "Create a desktop shortcut" box), a desktop shortcut.
--->
 <Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
-  <Package
-      Name="EffectCraft"
-      Manufacturer="Learning Machines LLC"
-      Version="$(var.Version)"
-      UpgradeCode="AACA8593-C6ED-40A8-BA6C-CB325D8529F9"
-      Scope="perMachine"
-      Compressed="yes"
-      Language="1033">
+  <Package Name="EffectCraft" Manufacturer="Learning Machines LLC" Version="$(var.Version)" UpgradeCode="AACA8593-C6ED-40A8-BA6C-CB325D8529F9" Scope="perUserOrMachine" Compressed="yes" Language="1033">
     <SummaryInformation Description="EffectCraft motion graphics and visual effects" Manufacturer="Learning Machines LLC" />
+    <?include $(sys.SOURCEFILEDIR)install-policy.wxi?>
     <!-- Same-version upgrades let successive pre-releases of one X.Y.Z replace each other
          (MSI versions are numeric, so 1.2.3-rc.1 and 1.2.3-rc.2 are both 1.2.3). -->
-    <MajorUpgrade AllowSameVersionUpgrades="yes"
-        DowngradeErrorMessage="A newer version of EffectCraft is already installed." />
+    <MajorUpgrade AllowSameVersionUpgrades="yes" DowngradeErrorMessage="A newer version of EffectCraft is already installed." />
     <MediaTemplate EmbedCab="yes" CompressionLevel="high" />
     <!-- The setup wizard (installer-ui.wxs): pick the folder on a fresh install. -->
     <UIRef Id="EffectcraftUI" />
@@ -36,32 +21,24 @@
          could be put elsewhere with INSTALLFOLDER=...) the folder of the effectcraft.exe that App Paths names. A
          "file" search with no FileSearch inside yields that file's folder. A folder passed on the
          command line (INSTALLFOLDER=...) wins. -->
-    <Property Id="INSTALLFOLDER" Secure="yes" />
     <Property Id="PREVIOUSINSTALLFOLDER" Secure="yes">
-      <RegistrySearch Id="PreviousInstallFolder" Root="HKLM" Type="directory"
-          Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Name="Path" />
+      <RegistrySearch Id="PreviousInstallFolder" Root="HKLM" Type="directory" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Name="Path" />
     </Property>
     <Property Id="PREVIOUSEXEFOLDER" Secure="yes">
-      <RegistrySearch Id="PreviousExeFolder" Root="HKLM" Type="file"
-          Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" />
+      <RegistrySearch Id="PreviousExeFolder" Root="HKLM" Type="file" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" />
     </Property>
-    <SetProperty Id="INSTALLFOLDER" Value="[PREVIOUSINSTALLFOLDER]" After="AppSearch" Sequence="both"
-        Condition="PREVIOUSINSTALLFOLDER AND NOT INSTALLFOLDER" />
-    <SetProperty Id="INSTALLFOLDER" Action="SetINSTALLFOLDERFromExe" Value="[PREVIOUSEXEFOLDER]"
-        After="SetINSTALLFOLDER" Sequence="both" Condition="PREVIOUSEXEFOLDER AND NOT INSTALLFOLDER" />
-
     <!-- The desktop shortcut: on by default for a fresh install (a box in the wizard, or
          DESKTOPSHORTCUT=0 silently); an upgrade keeps what the installed copy chose, and adds none
          to an install from before this option. -->
     <Property Id="DESKTOPSHORTCUT" Value="1" Secure="yes" />
     <Property Id="PREVIOUSDESKTOPSHORTCUT" Secure="yes">
-      <RegistrySearch Id="PreviousDesktopShortcut" Root="HKLM" Type="raw" Key="Software\EffectCraft" Name="DesktopShortcut" />
-    </Property>
-    <SetProperty Id="DESKTOPSHORTCUT" Value="[PREVIOUSDESKTOPSHORTCUT]" After="SetINSTALLFOLDERFromExe" Sequence="both"
-        Condition="WIX_UPGRADE_DETECTED" />
+      </Property>
+    <SetProperty Id="DESKTOPSHORTCUT" Value="[PREVIOUSDESKTOPSHORTCUT]" After="CraftLoadOption1U" Sequence="both" Condition="WIX_UPGRADE_DETECTED" />
 
     <StandardDirectory Id="ProgramFiles6432Folder">
-      <Directory Id="INSTALLFOLDER" Name="EffectCraft" />
+      <Directory Id="CraftSuiteFolder" Name="ArtCraft">
+        <Directory Id="INSTALLFOLDER" Name="EffectCraft" />
+      </Directory>
     </StandardDirectory>
     <StandardDirectory Id="ProgramMenuFolder" />
     <StandardDirectory Id="DesktopFolder" />
@@ -69,7 +46,9 @@
     <Feature Id="Main" Title="EffectCraft" Level="1">
       <ComponentGroupRef Id="EffectcraftFiles" />
     </Feature>
-  </Package>
+  <Property Id="CRAFT_OPTION_1_M" Secure="yes"><RegistrySearch Id="CRAFT_OPTION_1_MSearch" Root="HKLM" Type="raw" Key="Software\EffectCraft" Name="DesktopShortcut" />
+    </Property><SetProperty Id="PREVIOUSDESKTOPSHORTCUT" Action="CraftLoadOption1M" Value="[CRAFT_OPTION_1_M]" After="LaunchConditions" Sequence="both" Condition="ALLUSERS = 1" /><Property Id="CRAFT_OPTION_1_U" Secure="yes"><RegistrySearch Id="CRAFT_OPTION_1_USearch" Root="HKCU" Type="raw" Key="Software\EffectCraft" Name="DesktopShortcut" />
+    </Property><SetProperty Id="PREVIOUSDESKTOPSHORTCUT" Action="CraftLoadOption1U" Value="[CRAFT_OPTION_1_U]" After="CraftLoadOption1M" Sequence="both" Condition="ALLUSERS &lt;&gt; 1" /></Package>
 
   <Fragment>
     <ComponentGroup Id="EffectcraftFiles" Directory="INSTALLFOLDER">
@@ -78,15 +57,14 @@
       </Component>
       <Component Id="EffectcraftApp" Guid="BA719860-95FE-4154-B265-47006B8E9083">
         <File Id="EffectcraftExe" Source="$(var.BinDir)\effectcraft.exe" KeyPath="yes">
-          <Shortcut Id="StartMenuShortcut" Directory="ProgramMenuFolder" Name="EffectCraft"
-              Description="EffectCraft motion graphics and visual effects" WorkingDirectory="INSTALLFOLDER" Advertise="yes"
-              Icon="EffectcraftIcon.ico" IconIndex="0" />
+          <Shortcut Id="StartMenuShortcut" Directory="ProgramMenuFolder" Name="EffectCraft" Description="EffectCraft motion graphics and visual effects" WorkingDirectory="INSTALLFOLDER" Advertise="yes" Icon="EffectcraftIcon.ico" IconIndex="0" />
         </File>
 
-        <RegistryValue Root="HKLM" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Value="[#EffectcraftExe]" Type="string" />
-        <RegistryValue Root="HKLM" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Name="Path" Value="[INSTALLFOLDER]" Type="string" />
+        <RegistryValue Root="HKMU" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Value="[#EffectcraftExe]" Type="string" />
+        <RegistryValue Root="HKMU" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Name="Path" Value="[INSTALLFOLDER]" Type="string" />
         <!-- The desktop shortcut choice, for the next upgrade (empty: none). -->
-        <RegistryValue Root="HKLM" Key="Software\EffectCraft" Name="DesktopShortcut" Value="[DESKTOPSHORTCUT]" Type="string" />
+        <RegistryValue Root="HKMU" Key="Software\EffectCraft" Name="DesktopShortcut" Value="[DESKTOPSHORTCUT]" Type="string" />
+      <RegistryValue Root="HKMU" Key="Software\EffectCraft" Name="InstallDir" Value="[INSTALLFOLDER]" Type="string" />
       </Component>
 
       <Component Id="EffectcraftCli">
@@ -95,9 +73,8 @@
 
       <!-- A component under the user's profile folders needs an HKCU key path (ICE38, ICE43). -->
       <Component Id="DesktopShortcut" Directory="DesktopFolder" Condition="DESKTOPSHORTCUT = &quot;1&quot;">
-        <Shortcut Id="DesktopShortcut" Name="EffectCraft" Description="EffectCraft motion graphics and visual effects"
-            Target="[#EffectcraftExe]" WorkingDirectory="INSTALLFOLDER" Icon="EffectcraftIcon.ico" IconIndex="0" />
-        <RegistryValue Root="HKCU" Key="Software\EffectCraft" Name="DesktopShortcut" Value="1" Type="string" KeyPath="yes" />
+        <Shortcut Id="DesktopShortcut" Name="EffectCraft" Description="EffectCraft motion graphics and visual effects" Target="[#EffectcraftExe]" WorkingDirectory="INSTALLFOLDER" Icon="EffectcraftIcon.ico" IconIndex="0" />
+        <RegistryValue Root="HKMU" Key="Software\EffectCraft" Name="DesktopShortcut" Value="1" Type="string" KeyPath="yes" />
       </Component>
     </ComponentGroup>
   </Fragment>
diff --git a/packaging/windows/install-policy.json b/packaging/windows/install-policy.json
new file mode 100644
index 000000000..6553d217b
--- /dev/null
+++ b/packaging/windows/install-policy.json
@@ -0,0 +1,44 @@
+{
+  "id": "effectcraft",
+  "name": "EffectCraft",
+  "upgradeCode": "AACA8593-C6ED-40A8-BA6C-CB325D8529F9",
+  "sources": [
+    "effectcraft.wxs",
+    "installer-ui.wxs"
+  ],
+  "icon": "assets/app-icon/effectcraft.ico",
+  "localization": [],
+  "extensions": [],
+  "payloads": [
+    "NOTICE",
+    "effectcraft-cli.exe",
+    "effectcraft.exe"
+  ],
+  "registry": [
+    [
+      "-1",
+      "Software\\Microsoft\\Windows\\CurrentVersion\\App Paths\\effectcraft.exe",
+      "",
+      "[#EffectcraftExe]"
+    ],
+    [
+      "-1",
+      "Software\\Microsoft\\Windows\\CurrentVersion\\App Paths\\effectcraft.exe",
+      "Path",
+      "[INSTALLFOLDER]"
+    ],
+    [
+      "-1",
+      "Software\\EffectCraft",
+      "DesktopShortcut",
+      "[DESKTOPSHORTCUT]"
+    ],
+    [
+      "-1",
+      "Software\\EffectCraft",
+      "DesktopShortcut",
+      "1"
+    ]
+  ],
+  "mode": "dualScope"
+}
diff --git a/packaging/windows/install-policy.wxi b/packaging/windows/install-policy.wxi
new file mode 100644
index 000000000..669c08126
--- /dev/null
+++ b/packaging/windows/install-policy.wxi
@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Include xmlns="http://wixtoolset.org/schemas/v4/wxs">
+  <!-- Choose scope before launch checks and directory costing. Never move an existing copy. -->
+  <!-- Only for me leaves ALLUSERS unset. Publishing ALLUSERS=2 here makes FindRelatedProducts treat the run as
+       per-machine and skip the existing per-user copy, so an interactive upgrade installs beside it
+       (two registered products, and uninstall leaves files behind). Checked with real msiexec runs. -->
+  <Property Id="INSTALLFOLDER" Secure="yes" />
+  <Property Id="CRAFT_SCOPE" Value="user" Secure="yes" />
+  <Property Id="CRAFT_U_DIR" Secure="yes"><RegistrySearch Id="CRAFT_U_DIRSearch" Root="HKCU" Key="Software\EffectCraft" Name="InstallDir" Type="raw" /></Property>
+  <SetProperty Id="CRAFT_USER_DIR" Action="CraftUFromDIR" Value="[CRAFT_U_DIR]" After="AppSearch" Sequence="both" Condition="NOT CRAFT_USER_DIR AND CRAFT_U_DIR" />
+  <Property Id="CRAFT_U_FOLDER" Secure="yes"><RegistrySearch Id="CRAFT_U_FOLDERSearch" Root="HKCU" Key="Software\EffectCraft" Name="InstallFolder" Type="raw" /></Property>
+  <SetProperty Id="CRAFT_USER_DIR" Action="CraftUFromFOLDER" Value="[CRAFT_U_FOLDER]" After="CraftUFromDIR" Sequence="both" Condition="NOT CRAFT_USER_DIR AND CRAFT_U_FOLDER" />
+  <Property Id="CRAFT_U_PATH" Secure="yes"><RegistrySearch Id="CRAFT_U_PATHSearch" Root="HKCU" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Name="Path" Type="raw" /></Property>
+  <SetProperty Id="CRAFT_USER_DIR" Action="CraftUFromPATH" Value="[CRAFT_U_PATH]" After="CraftUFromFOLDER" Sequence="both" Condition="NOT CRAFT_USER_DIR AND CRAFT_U_PATH" />
+  <Property Id="CRAFT_U_EXEFOLDER" Secure="yes"><RegistrySearch Id="CRAFT_ULegacyFolder" Root="HKCU" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Type="file" /></Property>
+  <Property Id="CRAFT_U_EXE" Secure="yes"><RegistrySearch Id="CRAFT_ULegacyExe" Root="HKCU" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Type="file"><FileSearch Id="CRAFT_ULegacyFile" Name="effectcraft.exe" /></RegistrySearch></Property>
+  <SetProperty Id="CRAFT_USER_DIR" Action="CraftUFromLegacyExe" Value="[CRAFT_U_EXEFOLDER]" After="CraftUFromPATH" Sequence="both" Condition="NOT CRAFT_USER_DIR AND CRAFT_U_EXEFOLDER AND CRAFT_U_EXE" />
+  <Property Id="CRAFT_USER_DIR" Secure="yes" />
+  <Property Id="CRAFT_M_DIR" Secure="yes"><RegistrySearch Id="CRAFT_M_DIRSearch" Root="HKLM" Key="Software\EffectCraft" Name="InstallDir" Type="raw" /></Property>
+  <SetProperty Id="CRAFT_MACHINE_DIR" Action="CraftMFromDIR" Value="[CRAFT_M_DIR]" After="CraftUFromLegacyExe" Sequence="both" Condition="NOT CRAFT_MACHINE_DIR AND CRAFT_M_DIR" />
+  <Property Id="CRAFT_M_FOLDER" Secure="yes"><RegistrySearch Id="CRAFT_M_FOLDERSearch" Root="HKLM" Key="Software\EffectCraft" Name="InstallFolder" Type="raw" /></Property>
+  <SetProperty Id="CRAFT_MACHINE_DIR" Action="CraftMFromFOLDER" Value="[CRAFT_M_FOLDER]" After="CraftMFromDIR" Sequence="both" Condition="NOT CRAFT_MACHINE_DIR AND CRAFT_M_FOLDER" />
+  <Property Id="CRAFT_M_PATH" Secure="yes"><RegistrySearch Id="CRAFT_M_PATHSearch" Root="HKLM" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Name="Path" Type="raw" /></Property>
+  <SetProperty Id="CRAFT_MACHINE_DIR" Action="CraftMFromPATH" Value="[CRAFT_M_PATH]" After="CraftMFromFOLDER" Sequence="both" Condition="NOT CRAFT_MACHINE_DIR AND CRAFT_M_PATH" />
+  <Property Id="CRAFT_M_EXEFOLDER" Secure="yes"><RegistrySearch Id="CRAFT_MLegacyFolder" Root="HKLM" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Type="file" /></Property>
+  <Property Id="CRAFT_M_EXE" Secure="yes"><RegistrySearch Id="CRAFT_MLegacyExe" Root="HKLM" Key="Software\Microsoft\Windows\CurrentVersion\App Paths\effectcraft.exe" Type="file"><FileSearch Id="CRAFT_MLegacyFile" Name="effectcraft.exe" /></RegistrySearch></Property>
+  <SetProperty Id="CRAFT_MACHINE_DIR" Action="CraftMFromLegacyExe" Value="[CRAFT_M_EXEFOLDER]" After="CraftMFromPATH" Sequence="both" Condition="NOT CRAFT_MACHINE_DIR AND CRAFT_M_EXEFOLDER AND CRAFT_M_EXE" />
+  <Property Id="CRAFT_MACHINE_DIR" Secure="yes" />
+  <SetProperty Id="CRAFT_SCOPE" Action="CraftPreferMachineScope" Value="machine" After="CraftMFromLegacyExe" Sequence="ui" Condition="ALLUSERS = 1 OR (CRAFT_MACHINE_DIR AND NOT CRAFT_USER_DIR)" />
+  <SetProperty Id="INSTALLFOLDER" Action="CraftRestoreUserFolder" Value="[CRAFT_USER_DIR]" Before="CostInitialize" Sequence="both" Condition="NOT INSTALLFOLDER AND ALLUSERS &lt;&gt; 1 AND CRAFT_USER_DIR" />
+  <!-- The wizard can change the context after Windows Installer has already resolved Program Files for the first one.
+       Give the new-install folder explicitly so Everyone never lands in the profile and Only for me never lands in Program Files. -->
+  <?if $(sys.BUILDARCH) = x86 ?>
+  <SetProperty Id="INSTALLFOLDER" Action="CraftDefaultMachineFolder" Value="[%ProgramFiles(x86)]\ArtCraft\EffectCraft\" After="CraftRestoreUserFolder" Sequence="ui" Condition="NOT INSTALLFOLDER AND ALLUSERS = 1 AND VersionNT64" />
+  <SetProperty Id="INSTALLFOLDER" Action="CraftDefaultMachineFolder32" Value="[%ProgramFiles]\ArtCraft\EffectCraft\" After="CraftDefaultMachineFolder" Sequence="ui" Condition="NOT INSTALLFOLDER AND ALLUSERS = 1 AND NOT VersionNT64" />
+  <SetProperty Id="INSTALLFOLDER" Action="CraftDefaultUserFolder" Value="[LocalAppDataFolder]Programs\ArtCraft\EffectCraft\" After="CraftDefaultMachineFolder32" Sequence="ui" Condition="NOT INSTALLFOLDER AND ALLUSERS &lt;&gt; 1" />
+  <?else?>
+  <SetProperty Id="INSTALLFOLDER" Action="CraftDefaultMachineFolder" Value="[%ProgramW6432]\ArtCraft\EffectCraft\" After="CraftRestoreUserFolder" Sequence="ui" Condition="NOT INSTALLFOLDER AND ALLUSERS = 1" />
+  <SetProperty Id="INSTALLFOLDER" Action="CraftDefaultUserFolder" Value="[LocalAppDataFolder]Programs\ArtCraft\EffectCraft\" After="CraftDefaultMachineFolder" Sequence="ui" Condition="NOT INSTALLFOLDER AND ALLUSERS &lt;&gt; 1" />
+  <?endif?>
+  <SetProperty Id="INSTALLFOLDER" Action="CraftRestoreMachineFolder" Value="[CRAFT_MACHINE_DIR]" Before="CraftRestoreUserFolder" Sequence="both" Condition="NOT INSTALLFOLDER AND ALLUSERS = 1 AND CRAFT_MACHINE_DIR" />
+  <Launch Condition="Installed OR ALLUSERS &lt;&gt; 1 OR NOT CRAFT_USER_DIR" Message="This app is already installed for your account. Choose Only for me to update it, or uninstall that copy before changing who it is installed for." />
+  <Launch Condition="Installed OR ALLUSERS = 1 OR NOT CRAFT_MACHINE_DIR" Message="This app is already installed for everyone. Choose Everyone to update it, or pass ALLUSERS=1 to msiexec. Uninstall that copy before changing who it is installed for." />
+  <UI>
+    <TextStyle Id="CraftScopeText" FaceName="Segoe UI" Size="9" />
+    <TextStyle Id="CraftScopeTitle" FaceName="Segoe UI" Size="12" Bold="yes" />
+    <Dialog Id="CraftScopeDlg" Width="370" Height="220" Title="[ProductName] Setup" NoMinimize="yes">
+      <Control Id="Title" Type="Text" X="20" Y="15" Width="330" Height="30" Text="{\CraftScopeTitle}Who should use [ProductName]?" />
+      <Control Id="Info" Type="Text" X="20" Y="50" Width="330" Height="30" Text="{\CraftScopeText}An update keeps the existing folder. New copies use the ArtCraft folder under Programs." />
+      <Control Id="Scope" Type="RadioButtonGroup" X="20" Y="88" Width="330" Height="60" Property="CRAFT_SCOPE">
+        <RadioButtonGroup Property="CRAFT_SCOPE">
+          <RadioButton Value="user" X="0" Y="0" Width="330" Height="20" Text="Only for me (no administrator permission needed)" />
+          <RadioButton Value="machine" X="0" Y="30" Width="330" Height="20" Text="Everyone on this computer (asks an administrator)" />
+        </RadioButtonGroup>
+      </Control>
+      <Control Id="Next" Type="PushButton" X="214" Y="182" Width="66" Height="20" Default="yes" Text="Next">
+        <Publish Property="ALLUSERS" Value="1" Order="1" Condition="CRAFT_SCOPE = &quot;machine&quot;" />
+        <Publish Property="ALLUSERS" Value="{}" Order="2" Condition="CRAFT_SCOPE = &quot;user&quot;" />
+        <Publish Property="MSIINSTALLPERUSER" Value="{}" Order="3" Condition="CRAFT_SCOPE = &quot;machine&quot;" />
+        <Publish Property="MSIINSTALLPERUSER" Value="1" Order="4" Condition="CRAFT_SCOPE = &quot;user&quot;" />
+        <Publish Event="EndDialog" Value="Return" Order="5" />
+      </Control>
+      <Control Id="Cancel" Type="PushButton" X="290" Y="182" Width="60" Height="20" Cancel="yes" Text="Cancel"><Publish Event="EndDialog" Value="Exit" /></Control>
+    </Dialog>
+  </UI>
+  <InstallUISequence>
+    <Show Dialog="CraftScopeDlg" After="CraftPreferMachineScope" Condition="NOT Installed AND NOT REMOVE AND UILevel = 5" />
+    <!-- Related-product discovery runs once, so full UI must choose its context first. -->
+    <FindRelatedProducts After="CraftScopeDlg" />
+  </InstallUISequence>
+</Include>
diff --git a/packaging/windows/installer-ui.wxs b/packaging/windows/installer-ui.wxs
index 16ab58d7f..17c7efd0b 100644
--- a/packaging/windows/installer-ui.wxs
+++ b/packaging/windows/installer-ui.wxs
@@ -1,16 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!--
-  EffectCraft installer wizard: original dialogs built from Windows Installer's own controls and
-  events (no WixUI library), included by effectcraft.wxs with <UIRef Id="EffectcraftUI" />.
-
-    fresh install:  DestDlg (folder, Change... opens BrowseDlg, desktop shortcut) -> ReadyDlg -> ProgressDlg -> ExitDlg
-    upgrade:        ReadyDlg (the installed copy's folder, not editable) -> ProgressDlg -> ExitDlg
-    already there:  MaintDlg (Repair or Remove) -> ProgressDlg -> ExitDlg
-
-  Silent installs (/qn) skip all of this; pass INSTALLFOLDER="..." to choose the folder there.
-  Folder controls edit INSTALLFOLDER indirectly through _BrowseProperty; SetTargetPath checks the
-  path and applies it, and Windows Installer reports a bad path itself.
--->
 <Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
   <Fragment>
     <UI Id="EffectcraftUI">
@@ -78,7 +66,10 @@
         <Control Id="Back" Type="PushButton" X="180" Y="243" Width="56" Height="17" Text="&amp;Back" DisableCondition="WIX_UPGRADE_DETECTED">
           <Publish Event="NewDialog" Value="DestDlg" />
         </Control>
-        <Control Id="Install" Type="PushButton" X="236" Y="243" Width="56" Height="17" Default="yes" ElevationShield="yes" Text="&amp;Install">
+        <Control Id="Install" Type="PushButton" X="236" Y="243" Width="56" Height="17" Default="yes" DefaultCondition="ALLUSERS = 1" ElevationShield="yes" HideCondition="ALLUSERS &lt;&gt; 1" ShowCondition="ALLUSERS = 1" Text="&amp;Install">
+          <Publish Event="EndDialog" Value="Return" />
+        </Control>
+        <Control Id="InstallUser" Type="PushButton" DefaultCondition="ALLUSERS &lt;&gt; 1" HideCondition="ALLUSERS = 1" ShowCondition="ALLUSERS &lt;&gt; 1" X="236" Y="243" Width="56" Height="17" Text="&amp;Install">
           <Publish Event="EndDialog" Value="Return" />
         </Control>
         <Control Id="Cancel" Type="PushButton" X="304" Y="243" Width="56" Height="17" Cancel="yes" Text="Cancel">
@@ -90,7 +81,7 @@
       <Dialog Id="MaintDlg" Width="370" Height="270" Title="[ProductName] Setup">
         <Control Id="Title" Type="Text" X="20" Y="15" Width="330" Height="20" Transparent="yes" NoPrefix="yes" Text="{\EcTitle}[ProductName] is already installed" />
         <Control Id="Description" Type="Text" X="20" Y="45" Width="330" Height="24" NoPrefix="yes" Text="Repair puts back missing or damaged files in its folder. Remove uninstalls it; your projects are not touched." />
-        <Control Id="Repair" Type="PushButton" X="20" Y="80" Width="80" Height="20" Default="yes" ElevationShield="yes" Text="&amp;Repair">
+        <Control Id="Repair" Type="PushButton" X="20" Y="80" Width="80" Height="20" Default="yes" DefaultCondition="ALLUSERS = 1" ElevationShield="yes" HideCondition="ALLUSERS &lt;&gt; 1" ShowCondition="ALLUSERS = 1" Text="&amp;Repair">
           <!-- "a": put back every file, whatever its version or date. With "e"/"o" a changed
                unversioned file (effectcraft-cli.exe has no version resource) counts as a user edit
                and is kept, and "c" only checks files that carry an MSI checksum. -->
@@ -98,7 +89,19 @@
           <Publish Event="Reinstall" Value="ALL" Order="2" />
           <Publish Event="EndDialog" Value="Return" Order="3" />
         </Control>
-        <Control Id="Remove" Type="PushButton" X="20" Y="108" Width="80" Height="20" ElevationShield="yes" Text="Re&amp;move">
+        <Control Id="RepairUser" Type="PushButton" DefaultCondition="ALLUSERS &lt;&gt; 1" HideCondition="ALLUSERS = 1" ShowCondition="ALLUSERS &lt;&gt; 1" X="20" Y="80" Width="80" Height="20" Text="&amp;Repair">
+          <!-- "a": put back every file, whatever its version or date. With "e"/"o" a changed
+               unversioned file (effectcraft-cli.exe has no version resource) counts as a user edit
+               and is kept, and "c" only checks files that carry an MSI checksum. -->
+          <Publish Event="ReinstallMode" Value="amus" Order="1" />
+          <Publish Event="Reinstall" Value="ALL" Order="2" />
+          <Publish Event="EndDialog" Value="Return" Order="3" />
+        </Control>
+        <Control Id="Remove" Type="PushButton" X="20" Y="108" Width="80" Height="20" ElevationShield="yes" HideCondition="ALLUSERS &lt;&gt; 1" ShowCondition="ALLUSERS = 1" Text="Re&amp;move">
+          <Publish Event="Remove" Value="ALL" Order="1" />
+          <Publish Event="EndDialog" Value="Return" Order="2" />
+        </Control>
+        <Control Id="RemoveUser" Type="PushButton" HideCondition="ALLUSERS = 1" ShowCondition="ALLUSERS &lt;&gt; 1" X="20" Y="108" Width="80" Height="20" Text="Re&amp;move">
           <Publish Event="Remove" Value="ALL" Order="1" />
           <Publish Event="EndDialog" Value="Return" Order="2" />
         </Control>
diff --git a/packaging/windows/package.ps1 b/packaging/windows/package.ps1
index edbb163c0..e49fde52c 100644
--- a/packaging/windows/package.ps1
+++ b/packaging/windows/package.ps1
@@ -100,6 +100,8 @@ Invoke-Native 'wix build' {
     -d "Version=$MsiVersion" -d "BinDir=$Stage" -d "IconPath=$(Join-Path $Root 'assets\app-icon\effectcraft.ico')" `
     -o $Msi
 }
+# Check the compiled scope, path and registration contract before signing.
+& (Join-Path $PSScriptRoot 'check-install-policy.ps1') -MsiPath $Msi
 # wix writes its debug symbols (.wixpdb) next to the MSI; keep them out of the release assets.
 Remove-Item -Force -ErrorAction SilentlyContinue ([IO.Path]::ChangeExtension($Msi, '.wixpdb'))
 & (Join-Path $PSScriptRoot 'sign.ps1') $Msi
diff --git a/packaging/windows/test-install-policy.ps1 b/packaging/windows/test-install-policy.ps1
new file mode 100644
index 000000000..c28fe3950
--- /dev/null
+++ b/packaging/windows/test-install-policy.ps1
@@ -0,0 +1,55 @@
+<#
+.SYNOPSIS
+  Build non-executable installer metadata fixtures; never install them.
+#>
+param(
+  [Parameter(Mandatory = $true)] [string] $OutputDirectory,
+  [ValidateSet('x64','x86','arm64')] [string[]] $Architectures = @('x64','x86','arm64')
+)
+$ErrorActionPreference = 'Stop'
+Set-StrictMode -Version Latest
+$root = (Resolve-Path (Join-Path $PSScriptRoot '..\..')).Path
+$policy = Get-Content -Raw -LiteralPath (Join-Path $PSScriptRoot 'install-policy.json') | ConvertFrom-Json
+[void](New-Item -ItemType Directory -Force -Path $OutputDirectory)
+$output = (Resolve-Path -LiteralPath $OutputDirectory).Path
+& (Join-Path $PSScriptRoot 'test-legacy-fixture.ps1') -Work (Join-Path $output 'legacy-source')
+Add-Type -AssemblyName System.Drawing
+foreach ($arch in $Architectures) {
+  $stage = Join-Path $output $arch
+  [void](New-Item -ItemType Directory -Force -Path $stage)
+  foreach ($name in $policy.payloads) {
+    $destination = Join-Path $stage $name
+    [void](New-Item -ItemType Directory -Force -Path ([IO.Path]::GetDirectoryName($destination)))
+    Set-Content -LiteralPath $destination -Encoding Ascii -Value 'NON-EXECUTABLE MSI METADATA TEST FIXTURE'
+  }
+  foreach ($folder in @('docs','models','notices')) {
+    $path = Join-Path $stage $folder
+    [void](New-Item -ItemType Directory -Force -Path $path)
+    Set-Content -LiteralPath (Join-Path $path "$folder-fixture.txt") -Value 'Metadata test fixture, not a user file or model.'
+  }
+  foreach ($model in @('metadata-one.rten','metadata-two.rten')) {
+    Set-Content -LiteralPath (Join-Path (Join-Path $stage 'models') $model) -Encoding Ascii -Value 'NON-EXECUTABLE MODEL METADATA FIXTURE'
+  }
+  foreach ($spec in @(@('banner.bmp',493,58),@('dialog.bmp',493,312))) {
+    $bitmap = [Drawing.Bitmap]::new($spec[1],$spec[2],[Drawing.Imaging.PixelFormat]::Format24bppRgb)
+    try { $bitmap.Save((Join-Path $stage $spec[0]),[Drawing.Imaging.ImageFormat]::Bmp) }
+    finally { $bitmap.Dispose() }
+  }
+  Set-Content -LiteralPath (Join-Path $stage 'licence.rtf') -Encoding Ascii -Value '{\rtf1 Metadata test fixture.}'
+  $sources = @($policy.sources | ForEach-Object { Join-Path $PSScriptRoot $_ })
+  $msi = Join-Path $stage "$($policy.id)-NOT-INSTALLABLE.msi"
+  $extensions = @($policy.extensions | ForEach-Object { '-ext'; "WixToolset.$_.wixext" })
+  & wix build @sources -arch $arch @extensions `
+    -culture en-US -d 'Version=0.0.1' -d 'DisplayVersion=0.0.1-metadata-test' `
+    -d "BinDir=$stage" -d "IconPath=$(Join-Path $root $policy.icon)" `
+    -d "DocsDir=$(Join-Path $stage 'docs')" -d "ModelsDir=$(Join-Path $stage 'models')" `
+    -d "AppNoticesDir=$(Join-Path $stage 'notices')" -d 'HasCraftFontLicences=1' -d 'HasCli=1' `
+    -d "BannerBmp=$(Join-Path $stage 'banner.bmp')" -d "DialogBmp=$(Join-Path $stage 'dialog.bmp')" `
+    -d "UiBannerBmp=$(Join-Path $stage 'banner.bmp')" -d "UiDialogBmp=$(Join-Path $stage 'dialog.bmp')" `
+    -d "LicenseRtf=$(Join-Path $stage 'licence.rtf')" -o $msi @($policy.localization | ForEach-Object { '-loc'; Join-Path $PSScriptRoot $_ })
+  if ($LASTEXITCODE -ne 0) { throw "WiX validation failed for $arch (exit $LASTEXITCODE)." }
+  $shell = (Get-Process -Id $PID).Path
+  & $shell -NoProfile -ExecutionPolicy Bypass -File (Join-Path $PSScriptRoot 'check-install-policy.ps1') -MsiPath $msi
+  if ($LASTEXITCODE -ne 0) { throw "Compiled installer policy failed for $arch (exit $LASTEXITCODE)." }
+  Write-Output "PASS $arch metadata-only package. This is not an executable installer."
+}
diff --git a/packaging/windows/test-legacy-fixture.ps1 b/packaging/windows/test-legacy-fixture.ps1
new file mode 100644
index 000000000..44336dca9
--- /dev/null
+++ b/packaging/windows/test-legacy-fixture.ps1
@@ -0,0 +1,21 @@
+<# Exercise the legacy source transformation without building or installing. #>
+param([Parameter(Mandatory = $true)] [string] $Work)
+$ErrorActionPreference = 'Stop'
+[void](New-Item -ItemType Directory -Force -Path $Work)
+$source = Get-Content -Raw (Join-Path $PSScriptRoot 'test-msi.ps1')
+$start = $source.IndexOf('$Wxs =')
+$end = $source.IndexOf('$Msi = @{}', $start)
+if ($start -lt 0 -or $end -le $start) { throw 'Could not locate the legacy source transformation.' }
+# Run the test harness's exact source-producing block, with only scratch outputs.
+$block = $source.Substring($start, $end - $start).Replace('$PSScriptRoot', ("'" + $PSScriptRoot.Replace("'", "''") + "'"))
+Invoke-Expression $block
+[xml]$legacy = Get-Content -Raw $LegacyWxs
+$ns = New-Object Xml.XmlNamespaceManager($legacy.NameTable)
+$ns.AddNamespace('w', 'http://wixtoolset.org/schemas/v4/wxs')
+if ($legacy.SelectNodes('//w:RegistryValue[@Name="Path" or @Name="InstallDir" or @Name="InstallFolder"]', $ns).Count) {
+  throw 'Legacy fixture must omit every modern folder record so discovery uses the executable fallback.'
+}
+if (-not $legacy.SelectNodes('//w:RegistryValue[contains(@Value,"EffectcraftExe")]', $ns).Count) {
+  throw 'Legacy fixture must retain its executable registration.'
+}
+Write-Output 'PASS legacy fixture exposes only the executable-path fallback.'
diff --git a/packaging/windows/test-msi.ps1 b/packaging/windows/test-msi.ps1
index 5868c77b3..fbc463e4b 100644
--- a/packaging/windows/test-msi.ps1
+++ b/packaging/windows/test-msi.ps1
@@ -11,7 +11,7 @@
     3. upgrades to 0.0.3 the same way (found from the Path value 0.0.2 wrote),
     4. repairs a damaged (unversioned) CLI there with the wizard's Repair mode,
     5. uninstalls: files, the App Paths registration and the desktop shortcut go,
-    6. installs 0.0.3 with no folder and DESKTOPSHORTCUT=0: it must land in Program Files with no
+    6. installs 0.0.3 with no folder and DESKTOPSHORTCUT=0: it must land in Program Files\ArtCraft\EffectCraft (ALLUSERS=1) with no
        desktop shortcut, then uninstalls.
   The installs before step 6 take the default desktop shortcut, which upgrades keep.
   The wizard itself needs a person (or the snapshot steps in the PR); this covers what msiexec /qn
@@ -36,7 +36,9 @@ function Invoke-Native([string] $What, [scriptblock] $Block) {
 }
 function Invoke-Msiexec([string] $What, [string[]] $Arguments) {
   $log = Join-Path $Work "$($What -replace '\W', '-').log"
-  $p = Start-Process msiexec.exe -ArgumentList ($Arguments + '/qn', '/l*v', "`"$log`"") -Wait -PassThru
+  # This existing VM regression deliberately covers the all-users upgrade route.
+  $p = Start-Process msiexec.exe -ArgumentList ($Arguments + 'ALLUSERS=1', '/qn', '/norestart', '/l*v', "`"$log`"") -PassThru
+  if (-not $p.WaitForExit(300000)) { $p.Kill(); throw "msiexec ($What) exceeded five minutes; see $log" }
   if ($p.ExitCode -ne 0) { Get-Content $log -Tail 60; throw "msiexec ($What) exited $($p.ExitCode)" }
   Write-Output "ok $What"
 }
@@ -65,17 +67,20 @@ New-Item -ItemType Directory -Force -Path $Bin | Out-Null
 # The MSI only copies these. The app is versioned (it embeds VERSIONINFO); the real CLI has no
 # version resource, so its stand-in is an unversioned file too: Windows Installer keeps a changed
 # unversioned file on repair unless the repair mode forces it.
-Copy-Item (Join-Path $env:SystemRoot 'System32\notepad.exe') (Join-Path $Bin 'effectcraft.exe')
+Copy-Item (Join-Path $env:SystemRoot 'System32\cmd.exe') (Join-Path $Bin 'effectcraft.exe')
 [IO.File]::WriteAllText((Join-Path $Bin 'effectcraft-cli.exe'), 'effectcraft-cli stand-in')
+[IO.File]::WriteAllText((Join-Path $Bin 'NOTICE'), 'Test fixture notice')
 
 # 0.0.1 stands in for releases before this installer change: the same package without the App
-# Paths "Path" value.
+# Paths "Path" value or modern InstallDir/InstallFolder records.
 $Wxs = Join-Path $PSScriptRoot 'effectcraft.wxs'
 $LegacyWxs = Join-Path $Work 'effectcraft-legacy.wxs'
-$pathValue = '(?m)^.*<RegistryValue [^>]*Name="Path"[^>]*/>\r?\n'
+$pathValue = '(?m)^.*<RegistryValue [^>]*Name="(?:Path|InstallDir|InstallFolder)"[^>]*/>\r?\n'
 $text = Get-Content -Raw $Wxs
 if ($text -notmatch $pathValue) { throw "no App Paths Path value in $Wxs to leave out" }
 [IO.File]::WriteAllText($LegacyWxs, ($text -replace $pathValue, ''))
+# The legacy source lives in the scratch folder, so its local include must travel with it.
+Copy-Item (Join-Path $PSScriptRoot 'install-policy.wxi') (Join-Path $Work 'install-policy.wxi')
 
 $Msi = @{}
 foreach ($v in '0.0.1', '0.0.2', '0.0.3') {
@@ -90,7 +95,7 @@ foreach ($v in '0.0.1', '0.0.2', '0.0.3') {
 
 # Spaces and a non-ASCII letter (written as a char so the script's own encoding doesn't matter).
 $Custom = Join-Path $env:SystemDrive "EffectCraft Test $([char]0x00DC)nicode\My Apps"
-$Default = Join-Path $env:ProgramFiles 'EffectCraft'
+$Default = Join-Path $env:ProgramFiles 'ArtCraft\EffectCraft'
 if (Test-Path -LiteralPath $AppPaths) { throw 'EffectCraft is already installed here; run this on a clean machine' }
 
 Invoke-Msiexec 'install the legacy package to a custom folder' @('/i', "`"$($Msi['0.0.1'])`"", "INSTALLFOLDER=`"$Custom`"")
diff --git a/xtask/Cargo.toml b/xtask/Cargo.toml
index b9c781bce..afc767de2 100644
--- a/xtask/Cargo.toml
+++ b/xtask/Cargo.toml
@@ -5,6 +5,9 @@ edition.workspace = true
 license.workspace = true
 publish = false
 
+[lints]
+workspace = true
+
 [dependencies]
 serde_json = { workspace = true }
 
diff --git a/xtask/src/bench.rs b/xtask/src/bench.rs
index 55bf4ee40..96d171d2f 100644
--- a/xtask/src/bench.rs
+++ b/xtask/src/bench.rs
@@ -155,7 +155,7 @@ pub fn run(root: &Path, args: &[String]) -> Result<(), String> {
                 } else {
                     eprintln!("bench: {} {kind}", sc.name);
                 }
-                let row = measure(&bin, &dir, sc, kind, frames, &o.format, timer, &ctx)?;
+                let row = measure(&bin, &dir, sc, &Measurement { kind, frames, format: &o.format }, timer, &ctx)?;
                 append_line(&results_path, &row)?;
                 rows.push(row);
             }
@@ -679,8 +679,14 @@ fn utc(t: u64) -> String {
     format!("{y:04}-{}", dt.format("%m-%d %H:%M UTC"))
 }
 
-#[allow(clippy::too_many_arguments)]
-fn measure(bin: &Path, dir: &Path, sc: &Scenario, kind: &str, frames: u32, format: &str, timer: TimeTool, ctx: &RunContext) -> Result<Value, String> {
+struct Measurement<'a> {
+    kind: &'a str,
+    frames: u32,
+    format: &'a str,
+}
+
+fn measure(bin: &Path, dir: &Path, sc: &Scenario, measurement: &Measurement<'_>, timer: TimeTool, ctx: &RunContext) -> Result<Value, String> {
+    let Measurement { kind, frames, format } = *measurement;
     let out_dir = dir.join("out").join(format!("{}-{kind}", sc.name.replace(['/', '\\', ' '], "_")));
     let _ = std::fs::remove_dir_all(&out_dir);
     std::fs::create_dir_all(&out_dir).map_err(|e| format!("{}: {e}", out_dir.display()))?;
diff --git a/xtask/src/pdf_deps.rs b/xtask/src/pdf_deps.rs
index c26876897..78694c7a6 100644
--- a/xtask/src/pdf_deps.rs
+++ b/xtask/src/pdf_deps.rs
@@ -5,7 +5,7 @@ use std::process::Command;
 
 use serde_json::Value;
 
-const REV: &str = "512b54355cd1418f4e8c56a3fbd7483c3c274bf3";
+const REV: &str = "92d392cff132eaf53e13afff77f38b5c11b73aa0";
 const PACKAGES: &[(&str, &str)] = &[("craft-pdf", "0.1.0"), ("hayro-syntax", "0.7.2"), ("hayro-jbig2", "0.3.0")];
 
 pub fn run(root: &Path) -> Result<(), String> {