Text: an embedder of the egui panels may leave the bundled fonts out

#2027 gave vectorcraft-text and vectorcraft-engine a `bundled-fonts`
feature for an embedder that supplies every document font at run
time, but vectorcraft-ui-egui (and vectorcraft-mcp) named the engine
with its default features, so an embedder that hosts the panels got
the fonts whatever it asked for. Each now has a `bundled-fonts`
feature of its own, on by default, that turns the engine's on, so a
downstream user keeps the fonts unless it asks otherwise. For a
member to leave the engine's default features out, the workspace has
to declare the engine without them, as it already declares
vectorcraft-text; the crates that used the engine's default now ask
for the fonts: the three apps and vectorcraft-testkit. Off,
vectorcraft-text's copy of the fonts (3.4 MB) is left out; theme.rs's
own copies of five of them, the panels' interface faces, stay either
way.

Nothing the workspace builds changes: for every workspace member and
for the whole workspace, with and without dev-dependencies, for all
targets, wasm32-unknown-unknown, aarch64-apple-darwin and
x86_64-pc-windows-msvc, `cargo tree -e normal[,dev] -f '{p} [{f}]'`
resolves the same features for every package as on main, apart from
the new feature names (the engine's `default` no longer listed;
ui-egui's and mcp's `bundled-fonts` and `default`).

A test of the panels can't see their configuration without the fonts
(their dev-dependencies turn them on), so `cargo xtask ci`'s
`no-bundled-fonts` step now also reads that tree for
vectorcraft-ui-egui and vectorcraft-mcp: with their default features
it must show the fonts, and without them, for any target (a wasm-only
dependency too), it must not. Documented in docs/development.md
(Fonts › Leaving out the bundled fonts).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Cargo.toml

@@ -25,8 +25,9 @@ vectorcraft-doc = { path = "crates/doc" }
 vectorcraft-pathops = { path = "crates/pathops" }
 vectorcraft-brush = { path = "crates/brush" }
 vectorcraft-trace = { path = "crates/trace" }
-# Without its default `bundled-fonts`: the engine turns them on (its own default feature), so a
-# library crate never forces them on an embedder that supplies its fonts at run time.
+# Without its default `bundled-fonts`: a crate that wants the fonts asks for them (the apps and
+# vectorcraft-testkit through the engine's `bundled-fonts`), so a library crate never forces them on
+# an embedder that supplies its fonts at run time.
 vectorcraft-text = { path = "crates/text", default-features = false }
 vectorcraft-effects = { path = "crates/effects" }
 vectorcraft-three-d = { path = "crates/three-d" }
@@ -35,7 +36,9 @@ vectorcraft-svg = { path = "crates/svg" }
 vectorcraft-pdf = { path = "crates/pdf" }
 vectorcraft-format = { path = "crates/format" }
 vectorcraft-tools = { path = "crates/tools" }
-vectorcraft-engine = { path = "crates/engine" }
+# Without its default `bundled-fonts`, as vectorcraft-text: each crate that wants the fonts asks for
+# them, so an embedder can build without them (docs/development.md › Leaving out the bundled fonts).
+vectorcraft-engine = { path = "crates/engine", default-features = false }
 vectorcraft-ui-egui = { path = "crates/ui-egui" }
 vectorcraft-mcp = { path = "crates/mcp" }
 vectorcraft-testkit = { path = "crates/testkit" }

apps/vectorcraft-cli/Cargo.toml

@@ -16,7 +16,7 @@ workspace = true
 [dependencies]
 vectorcraft-color = { workspace = true }
 vectorcraft-doc = { workspace = true }
-vectorcraft-engine = { workspace = true }
+vectorcraft-engine = { workspace = true, features = ["bundled-fonts"] }
 vectorcraft-format = { workspace = true }
 vectorcraft-geom = { workspace = true }
 vectorcraft-svg = { workspace = true }

apps/vectorcraft-web/Cargo.toml

@@ -14,7 +14,7 @@ name = "vectorcraft-web"
 path = "src/main.rs"
 
 [dependencies]
-vectorcraft-engine = { workspace = true }
+vectorcraft-engine = { workspace = true, features = ["bundled-fonts"] }
 vectorcraft-ui-egui = { workspace = true }
 vectorcraft-format = { workspace = true }
 vectorcraft-text = { workspace = true }

apps/vectorcraft/Cargo.toml

@@ -17,7 +17,7 @@ accessibility = ["eframe/accesskit"]
 windows7 = ["eframe/glow"]
 
 [dependencies]
-vectorcraft-engine = { workspace = true }
+vectorcraft-engine = { workspace = true, features = ["bundled-fonts"] }
 vectorcraft-ui-egui = { workspace = true }
 vectorcraft-text = { workspace = true }
 # Shared across the Craft suite: decides who draws the window frame per desktop (compositor vs app)

crates/mcp/Cargo.toml

@@ -8,6 +8,12 @@ description = "VectorCraft MCP server: JSON-RPC 2.0 over stdio, driving a runnin
 [lints]
 workspace = true
 
+[features]
+default = ["bundled-fonts"]
+# The fonts vectorcraft-text bundles for documents, through the engine's `bundled-fonts`, as
+# vectorcraft-ui-egui's. Off, for an embedder that supplies every document font at run time.
+bundled-fonts = ["vectorcraft-engine/bundled-fonts"]
+
 [dependencies]
 vectorcraft-engine = { workspace = true }
 vectorcraft-render = { workspace = true }

crates/testkit/Cargo.toml

@@ -13,7 +13,7 @@ workspace = true
 vectorcraft-geom = { workspace = true }
 vectorcraft-color = { workspace = true }
 vectorcraft-doc = { workspace = true }
-vectorcraft-engine = { workspace = true }
+vectorcraft-engine = { workspace = true, features = ["bundled-fonts"] }
 vectorcraft-render = { workspace = true }
 vectorcraft-format = { workspace = true }
 vectorcraft-svg = { workspace = true }

crates/text/Cargo.toml

@@ -37,7 +37,8 @@ default = ["bundled-fonts"]
 # The OFL fonts of `assets/fonts` (Source Sans 3, Source Serif 4, Inter, JetBrains Mono) compiled
 # in: 3.4 MB of the binary. Off, the font database starts without them (craft-fonts and system
 # fonts are unaffected), for an embedder that adds its own with `FontDb::add_font` and would ship
-# these twice. vectorcraft-engine turns it on by default (its `bundled-fonts` feature).
+# these twice. vectorcraft-engine turns it on by default (its `bundled-fonts` feature), and
+# vectorcraft-ui-egui and vectorcraft-mcp by default through the engine.
 bundled-fonts = []
 # `vectorcraft_text::test_fonts` for other crates' tests (dev-dependencies only).
 test-fonts = ["dep:write-fonts"]

crates/ui-egui/Cargo.toml

@@ -8,6 +8,13 @@ description = "VectorCraft egui frontend (menus, panels, tools and canvas); swap
 [lints]
 workspace = true
 
+[features]
+default = ["bundled-fonts"]
+# The fonts vectorcraft-text bundles for documents, through the engine's `bundled-fonts`. Off, for
+# an embedder that supplies every document font at run time (`vectorcraft_text::FontDb::add_font`);
+# the interface's own faces are separate copies in theme.rs and stay either way.
+bundled-fonts = ["vectorcraft-engine/bundled-fonts"]
+
 [dependencies]
 craft-ui = { workspace = true }
 vectorcraft-geom = { workspace = true }

docs/development.md

@@ -1,5 +1,6 @@
 # Development
 
+> **Last updated:** 2026-10-21 · **Change:** leaving out the bundled fonts with the egui panels (vectorcraft-ui-egui's and vectorcraft-mcp's `bundled-fonts` features).
 > **Last updated:** 2026-10-14 · **Change:** leaving out the bundled fonts (`bundled-fonts` feature).
 > **Last updated:** 2026-10-14 · **Change:** document-font registration for all explicitly supplied faces.
 
@@ -160,15 +161,28 @@ CRAFT_FONTS_DIR="$PWD/../craft-fonts" cargo xtask ci   # also runs the Japanese-
 
 The Latin fonts in `assets/fonts/` are compiled into `vectorcraft-text` by its `bundled-fonts`
 feature (3.4 MB of the binary). It is on by default, and `vectorcraft-engine`'s default
-`bundled-fonts` feature turns it on, so the apps and anything built on the engine have them. An
+`bundled-fonts` feature turns it on, so the apps and anything built on the engine with its default
+features have them. An
 embedder that brings every font itself at run time (`FontDb::add_font`, say a web app serving its
 own font catalogue) depends on the engine with `default-features = false` and doesn't ship them
 twice. Its font database starts without them: on the web and without craft-fonts it starts empty,
 and text has no glyphs until a font is added.
 
-- The workspace declares `vectorcraft-text` without default features, so no library crate turns the
-  fonts back on; a crate whose tests lay type out asks for `bundled-fonts` in its
-  dev-dependencies (or gets it through `vectorcraft-testkit`, which uses the engine).
+An embedder that also hosts the egui panels depends on `vectorcraft-ui-egui` with
+`default-features = false` as well: its own `bundled-fonts` feature, on by default, turns the
+engine's on; `vectorcraft-mcp` has the same feature. The panels' interface faces (Source Sans 3
+Regular and Semibold, Inter Regular and SemiBold, JetBrains Mono) are separate copies in
+`theme.rs` and stay either way.
+
+- The workspace declares `vectorcraft-text` and `vectorcraft-engine` without default features, so
+  each crate that wants the fonts asks for them (the apps, and `vectorcraft-testkit` for tests);
+  a crate whose tests lay type out asks for `bundled-fonts` in its dev-dependencies (or gets it
+  through `vectorcraft-testkit`).
+- `cargo xtask ci`'s `no-bundled-fonts` step also checks that `vectorcraft-ui-egui` and
+  `vectorcraft-mcp` without their default features turn them on nowhere, for any target
+  (`cargo tree -p vectorcraft-ui-egui --no-default-features --target all -e features,normal -i
+  vectorcraft-text`, and the same for `vectorcraft-mcp`), and with them do; a test of either can't
+  see that configuration, since their dev-dependencies turn the fonts on.
 - `cargo test -p vectorcraft-text --no-default-features --test without_bundled_fonts` checks the
   configuration without them.
 
@@ -375,6 +389,7 @@ do not replace expected hashes automatically in response to a download mismatch.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-21 | minor | Fonts › Leaving out the bundled fonts: vectorcraft-ui-egui's and vectorcraft-mcp's `bundled-fonts` features, and the engine declared without default features. |
 | 2026-10-14 | minor | Document the `bundled-fonts` feature of vectorcraft-text and vectorcraft-engine (Fonts › Leaving out the bundled fonts). |
 | 2026-10-14 | minor | Document registration of every explicitly supplied craft-fonts face after the existing script-specific prefix; empty input and web selection remain unchanged. |
 | 2026-10-13 | minor | Document pinned PngSuite files, integrity checks and download budgets (#1729). |

xtask/src/main.rs

@@ -105,6 +105,40 @@ fn run(mut cmd: Command, what: &str) -> Result<(), String> {
     if status.success() { Ok(()) } else { Err(format!("{what}: exited with {status}")) }
 }
 
+/// `vectorcraft-ui-egui` and `vectorcraft-mcp` without their default features leave
+/// vectorcraft-text's bundled fonts out: no crate they depend on turns them on (docs/development.md
+/// › Leaving out the bundled fonts). The same tree with the default features must show them, so a
+/// change in cargo tree's output can't make the check pass by finding nothing.
+fn libraries_without_bundled_fonts() -> Result<(), String> {
+    ["vectorcraft-ui-egui", "vectorcraft-mcp"].into_iter().try_for_each(without_bundled_fonts)
+}
+
+fn without_bundled_fonts(package: &str) -> Result<(), String> {
+    const FEATURE: &str = "vectorcraft-text feature \"bundled-fonts\"";
+    let tree = |defaults: bool| -> Result<String, String> {
+        let mut args = vec!["tree", "-p", package, "--target", "all", "-e", "features,normal", "-i", "vectorcraft-text"];
+        if !defaults {
+            args.insert(3, "--no-default-features");
+        }
+        let what = format!("cargo {}", args.join(" "));
+        eprintln!("$ {what}");
+        let out = cargo().args(&args).output().map_err(|e| format!("{what}: failed to spawn: {e}"))?;
+        if !out.status.success() {
+            return Err(format!("{what}: exited with {}:\n{}", out.status, String::from_utf8_lossy(&out.stderr)));
+        }
+        Ok(String::from_utf8_lossy(&out.stdout).into_owned())
+    };
+    let with = tree(true)?;
+    if !with.contains(FEATURE) {
+        return Err(format!("{package} with its default features shows no {FEATURE} (has cargo tree's output changed?):\n{with}"));
+    }
+    let without = tree(false)?;
+    if without.contains(FEATURE) {
+        return Err(format!("{package} without default features still bundles the fonts:\n{without}"));
+    }
+    Ok(())
+}
+
 pub fn metadata() -> Result<serde_json::Value, String> {
     let out = cargo().args(["metadata", "--format-version", "1", "--no-deps"]).output().map_err(|e| format!("cargo metadata: {e}"))?;
     if !out.status.success() {
@@ -212,7 +246,10 @@ fn cmd_ci() -> Result<(), String> {
                 // vectorcraft-text as embedders that bring their own fonts build it.
                 let mut c = cargo();
                 c.args(["test", "-p", "vectorcraft-text", "--no-default-features", "--test", "without_bundled_fonts"]);
-                run(c, "cargo test -p vectorcraft-text --no-default-features --test without_bundled_fonts")
+                run(c, "cargo test -p vectorcraft-text --no-default-features --test without_bundled_fonts")?;
+                // The egui panels and the MCP server as such an embedder builds them: nothing turns
+                // the fonts back on.
+                libraries_without_bundled_fonts()
             }),
         ),
         ("pdf-deps", Box::new(|| pdf_deps::run(&root()))),