From be9c9077cd62232f3a6ecac2a6c2d309cfb68545 Mon Sep 17 00:00:00 2001
From: p01ntov <278898977+p01ntov@users.noreply.github.com>
Date: Sat, 17 Oct 2026 13:56:35 +0300
Subject: [PATCH 1/8] G2: tessellate viewer path overlays in screen space

---
 crates/ui-egui/src/panels/viewer_overlays.rs | 152 ++++++++++++++++++-
 1 file changed, 146 insertions(+), 6 deletions(-)

diff --git a/crates/ui-egui/src/panels/viewer_overlays.rs b/crates/ui-egui/src/panels/viewer_overlays.rs
index 9117103d5..d0875941e 100644
--- a/crates/ui-egui/src/panels/viewer_overlays.rs
+++ b/crates/ui-egui/src/panels/viewer_overlays.rs
@@ -132,17 +132,52 @@ pub(crate) fn path_of(ectx: &EvalCtx, layer: LayerId, uid: u64) -> Option<PathIn
 /// The path on screen: `sp` through `m` and the viewer map, flattened, with the closing point
 /// repeated for a closed path.
 pub(crate) fn flatten(sp: &ShapePath, m: &Mat3, map: &ViewerMap) -> Vec<Pos2> {
-    let k = effectcraft_engine::render::kurbo_path(sp);
+    let mut k = effectcraft_engine::render::kurbo_path(sp);
+    // A path-space tolerance becomes visible corners when the viewer or a layer/group is
+    // magnified. Flatten affine paths in screen space so the error stays below half a point.
+    // Projective transforms must still map the flattened points: projecting Bezier control
+    // points would change the curve rather than just its tessellation.
+    let screen_space = m.is_affine();
+    if screen_space {
+        let z = f64::from(map.zoom);
+        k.apply_affine(kurbo::Affine::new([
+            m.0[0][0] * z,
+            m.0[1][0] * z,
+            m.0[0][1] * z,
+            m.0[1][1] * z,
+            m.0[0][2] * z + f64::from(map.origin.x),
+            m.0[1][2] * z + f64::from(map.origin.y),
+        ]));
+    }
+    if !k.is_finite() {
+        return Vec::new();
+    }
+    let bounds = k.control_box();
+    if [bounds.x0, bounds.y0, bounds.x1, bounds.y1].iter().any(|v| v.abs() > f64::from(f32::MAX)) {
+        return Vec::new();
+    }
+    // Bound subdivision work even for extreme finite scales from a malformed project. For
+    // ordinary on-screen paths the tolerance remains half a point.
+    let tolerance = (bounds.width().max(bounds.height()) / 1_000_000.0).max(0.5);
     let mut pts: Vec<Pos2> = vec![];
-    kurbo::flatten(k.iter(), 0.5, |el| match el {
+    kurbo::flatten(k.iter(), tolerance, |el| match el {
         kurbo::PathEl::MoveTo(q) | kurbo::PathEl::LineTo(q) => {
-            let c = m.apply(gv2(q.x, q.y));
-            pts.push(map.to_screen([c.x, c.y]));
+            let p = if screen_space {
+                egui::pos2(q.x as f32, q.y as f32)
+            } else {
+                let c = m.apply(gv2(q.x, q.y));
+                map.to_screen([c.x, c.y])
+            };
+            if p.is_finite() {
+                pts.push(p);
+            }
         }
         _ => {}
     });
-    if sp.closed && !pts.is_empty() {
-        pts.push(pts[0]);
+    if sp.closed
+        && let Some(first) = pts.first().copied()
+    {
+        pts.push(first);
     }
     pts
 }
@@ -679,6 +714,111 @@ mod tests {
         PathInfo { layer: LayerId(3), uid: 7, m: Mat3::IDENTITY, sp, is_mask: true, feather: Vec::new() }
     }
 
+    fn circle() -> ShapePath {
+        let r = 38.0;
+        let h = r * 0.552_284_749_830_793_6;
+        ShapePath {
+            vertices: vec![[0.0, -r], [r, 0.0], [0.0, r], [-r, 0.0]],
+            in_tangents: vec![[-h, 0.0], [0.0, -h], [h, 0.0], [0.0, h]],
+            out_tangents: vec![[h, 0.0], [0.0, h], [-h, 0.0], [0.0, -h]],
+            closed: true,
+            feather: Vec::new(),
+        }
+    }
+
+    /// Measure the actual screen-space error against dense samples of the original cubics,
+    /// independently of the tessellator's chosen subdivisions.
+    fn screen_error(sp: &ShapePath, m: &Mat3, map: &ViewerMap, points: &[Pos2]) -> f32 {
+        let mut worst = 0.0_f32;
+        for i in 0..sp.vertices.len() {
+            let Some(c) = segment(sp, i) else { continue };
+            for step in 0..=1024 {
+                let q = cubic(c[0], c[1], c[2], c[3], f64::from(step) / 1024.0);
+                let q = m.apply(gv2(q[0], q[1]));
+                let p = map.to_screen([q.x, q.y]);
+                let distance = points
+                    .windows(2)
+                    .map(|pair| {
+                        let a = pair[0];
+                        let v = pair[1] - a;
+                        let t = if v.length_sq() > 0.0 { ((p - a).dot(v) / v.length_sq()).clamp(0.0, 1.0) } else { 0.0 };
+                        p.distance(a + v * t)
+                    })
+                    .fold(f32::INFINITY, f32::min);
+                worst = worst.max(distance);
+            }
+        }
+        worst
+    }
+
+    #[test]
+    fn curve_overlay_stays_smooth_at_viewer_magnifications() {
+        let sp = circle();
+        let mut counts = Vec::new();
+        for zoom in [0.5, 1.0, 5.0] {
+            let map = ViewerMap { origin: egui::pos2(121.25, 210.5), zoom, comp: [640.0, 400.0], area: Rect::EVERYTHING };
+            let points = flatten(&sp, &Mat3::IDENTITY, &map);
+            let error = screen_error(&sp, &Mat3::IDENTITY, &map, &points);
+            assert!(error <= 0.51, "{zoom}x: {error} screen points from the curve");
+            assert_eq!(points.first(), points.last(), "closed paths keep their closing edge");
+            for v in &sp.vertices {
+                let anchor = map.to_screen(*v);
+                assert!(points.iter().any(|p| p.distance(anchor) < 0.001), "original vertex missing at {zoom}x");
+            }
+            counts.push(points.len());
+        }
+        assert!(counts[0] < counts[1] && counts[1] < counts[2], "tessellation follows visible curve size: {counts:?}");
+    }
+
+    #[test]
+    fn curve_overlay_accounts_for_nonuniform_layer_and_group_transforms() {
+        let sp = circle();
+        let layer = Mat3::translate(gv2(70.0, 50.0)) * Mat3::rotate_deg(27.0) * Mat3::scale(gv2(3.2, 0.8));
+        let group = Mat3::rotate_deg(-19.0) * Mat3::skew_deg(25.0, 11.0) * Mat3::scale(gv2(0.7, 2.5));
+        let m = layer * group;
+        for zoom in [0.5, 1.0, 5.0] {
+            let map = ViewerMap { origin: egui::pos2(121.25, 210.5), zoom, comp: [640.0, 400.0], area: Rect::EVERYTHING };
+            let points = flatten(&sp, &m, &map);
+            let error = screen_error(&sp, &m, &map, &points);
+            assert!(error <= 0.51, "{zoom}x transformed path: {error} screen points from the curve");
+        }
+    }
+
+    #[test]
+    fn open_overlay_preserves_its_transformed_endpoints() {
+        let sp = info(vec![[10.0, 20.0], [50.0, 60.0]], false).sp;
+        let m = Mat3::translate(gv2(70.0, 50.0)) * Mat3::rotate_deg(27.0) * Mat3::scale(gv2(3.2, 0.8));
+        let map = ViewerMap { origin: egui::pos2(121.25, 210.5), zoom: 5.0, comp: [640.0, 400.0], area: Rect::EVERYTHING };
+        let points = flatten(&sp, &m, &map);
+        assert_ne!(points.first(), points.last(), "an open path must not gain a closing edge");
+        for (point, vertex) in [points.first(), points.last()].into_iter().zip([sp.vertices.first(), sp.vertices.last()]) {
+            let q = m.apply(gv2(vertex.unwrap()[0], vertex.unwrap()[1]));
+            assert!(point.unwrap().distance(map.to_screen([q.x, q.y])) < 0.001);
+        }
+    }
+
+    #[test]
+    fn invalid_overlay_coordinates_are_not_tessellated() {
+        let sp = circle();
+        for zoom in [f32::NAN, f32::INFINITY] {
+            let map = ViewerMap { origin: Pos2::ZERO, zoom, comp: [640.0, 400.0], area: Rect::EVERYTHING };
+            assert!(flatten(&sp, &Mat3::IDENTITY, &map).is_empty());
+        }
+        let map = ViewerMap { origin: Pos2::ZERO, zoom: 5.0, comp: [640.0, 400.0], area: Rect::EVERYTHING };
+        assert!(flatten(&sp, &Mat3::scale(gv2(f64::INFINITY, 1.0)), &map).is_empty());
+    }
+
+    #[test]
+    fn extreme_finite_overlay_scales_keep_subdivision_bounded() {
+        let map = ViewerMap { origin: Pos2::ZERO, zoom: 5.0, comp: [640.0, 400.0], area: Rect::EVERYTHING };
+        let sp = circle();
+        let points = flatten(&sp, &Mat3::scale(gv2(1e12, 1e12)), &map);
+        assert!(!points.is_empty());
+        assert!(points.len() < 10_000, "extreme scales must not allocate millions of vertices");
+        assert!(points.iter().all(|p| p.is_finite()));
+        assert!(flatten(&sp, &Mat3::scale(gv2(1e300, 1e300)), &map).is_empty());
+    }
+
     /// #912: clicking the last vertex of an open path with the Pen resumes that path.
     #[test]
     fn pen_resumes_an_open_path_at_its_last_vertex() {

From 63ec5f2aad6d865cd3cb75428a1f222e32753252 Mon Sep 17 00:00:00 2001
From: erythrofr <20369086+erythrofr@users.noreply.github.com>
Date: Fri, 30 Oct 2026 00:39:56 +0100
Subject: [PATCH 2/8] Export: apply crop once when calculating resize
 dimensions

Calculate frame_size from the original rendered dimensions and effective
render scale before cropping, so locked-aspect resize does not apply the
crop margins a second time in its dimension calculation.

Add dimension and decoded-PNG regressions for crop, resize, padding, scaled
ROI, both interpolation qualities, and zero or extreme requested sizes.

AI assistance: OpenAI Codex (GPT-6).
---
 crates/export/src/pipeline.rs             | 84 ++++++++++++++++++++++-
 crates/export/tests/it/render_settings.rs | 23 +++++++
 2 files changed, 106 insertions(+), 1 deletion(-)

diff --git a/crates/export/src/pipeline.rs b/crates/export/src/pipeline.rs
index c639ebad1..7b9e4111c 100644
--- a/crates/export/src/pipeline.rs
+++ b/crates/export/src/pipeline.rs
@@ -431,12 +431,13 @@ impl<'a> Cx<'a> {
     fn crop_resize(&self, img: Image) -> Image {
         let om = self.job.output;
         let scale = self.comp().map(|c| self.job.settings.effective_scale(c)).unwrap_or_else(|| self.job.settings.resolution.clamp(0.01, 4.0));
+        // frame_size applies crop itself: use the original frame and the same scale as edges.
+        let (w, h) = om.frame_size(img.width, img.height, scale);
         let (t, l, b, r) = om.crop.edges(img.width, img.height, scale);
         let img = if (t, l, b, r) == (0, 0, 0, 0) { img } else { crop(&img, t, l, b, r) };
         if !om.resize.enabled {
             return img;
         }
-        let (w, h) = om.frame_size(img.width, img.height, 1.0);
         if (w, h) == (img.width, img.height) {
             return img;
         }
@@ -1062,6 +1063,87 @@ mod tests {
         }
     }
 
+    #[test]
+    fn crop_resize_applies_margins_once() {
+        use effectcraft_project::render_queue::{Crop, OutputModule, Resize};
+        let output = OutputModule {
+            crop: Crop { enabled: true, left: 480, right: 480, ..Default::default() },
+            resize: Resize { enabled: true, width: 1280, lock_aspect: true, quality: ResizeQuality::Low, ..Default::default() },
+            ..Default::default()
+        };
+        assert_eq!(output.frame_size(1920, 1080, 1.0), (1280, 1440));
+        let img = run_crop_resize(Image::new(1920, 1080), &output, 1.0);
+        assert_eq!((img.width, img.height), (1280, 1440));
+        assert_eq!(img.data.len(), 1280 * 1440);
+    }
+
+    fn run_crop_resize(img: Image, output: &effectcraft_project::render_queue::OutputModule, scale: f64) -> Image {
+        use effectcraft_project::render_queue::RenderSettings;
+        let project = Project::default();
+        let settings = RenderSettings { resolution: scale, ..Default::default() };
+        let job = Job {
+            project: &project,
+            footage: &effectcraft_render::NoFootage,
+            expr: None,
+            accel: None,
+            comp: effectcraft_project::ItemId(0),
+            settings: &settings,
+            output,
+            path: "unused.png",
+            sink: None,
+            nested_switches: true,
+            options: Default::default(),
+        };
+        Cx::new(&job).crop_resize(img)
+    }
+
+    #[test]
+    fn crop_resize_dimensions_match_the_output_module() {
+        use effectcraft_project::render_queue::{Crop, OutputModule, Resize};
+        let edges = Crop { enabled: true, left: 2, right: 2, ..Default::default() };
+        let padding = Crop { enabled: true, left: -2, bottom: -2, ..Default::default() };
+        let roi = |rect| Crop { enabled: true, use_roi: true, roi: Some(rect), ..Default::default() };
+        for quality in [ResizeQuality::Low, ResizeQuality::High] {
+            let resize = |width| Resize { enabled: true, width, height: 1, lock_aspect: true, quality };
+            for (crop, resize, scale, expected) in [
+                (Crop::default(), Resize::default(), 1.0, (8, 6)),
+                (edges, Resize::default(), 1.0, (4, 6)),
+                (Crop::default(), resize(4), 1.0, (4, 3)),
+                (edges, resize(8), 1.0, (8, 12)),
+                (padding, resize(5), 1.0, (5, 4)),
+                (roi([4.0, 2.0, 8.0, 6.0]), resize(8), 0.5, (8, 6)),
+                (roi([1.0, 0.5, 2.0, 1.5]), resize(8), 2.0, (8, 6)),
+                (edges, Resize { lock_aspect: false, height: 2, ..resize(5) }, 1.0, (5, 2)),
+            ] {
+                let output = OutputModule { crop, resize, ..Default::default() };
+                assert_eq!(output.frame_size(8, 6, scale), expected);
+                let img = run_crop_resize(Image::filled(8, 6, [0.25, 0.0, 0.0, 0.5]), &output, scale);
+                assert_eq!((img.width, img.height), expected, "{crop:?}, {resize:?}, scale {scale}");
+                assert_eq!(img.data.len(), expected.0 as usize * expected.1 as usize);
+            }
+        }
+    }
+
+    #[test]
+    fn crop_resize_zero_and_extreme_sizes_stay_bounded() {
+        use effectcraft_project::render_queue::{Crop, OutputModule, Resize};
+        for quality in [ResizeQuality::Low, ResizeQuality::High] {
+            for (size, crop, width, height, expected) in [
+                ((8, 6), Crop::default(), 0, 0, (1, 1)),
+                ((8, 1), Crop::default(), u32::MAX, 1, (30_000, 1)),
+                ((1, 8), Crop::default(), 1, u32::MAX, (1, 30_000)),
+                ((8, 6), Crop { enabled: true, left: 20_000, right: 20_000, ..Default::default() }, 2, 3, (2, 3)),
+                ((0, 0), Crop { enabled: true, left: 1, top: 1, ..Default::default() }, 2, 3, (2, 3)),
+            ] {
+                let output = OutputModule { crop, resize: Resize { enabled: true, width, height, lock_aspect: false, quality }, ..Default::default() };
+                let img = run_crop_resize(Image::new(size.0, size.1), &output, 1.0);
+                assert_eq!((img.width, img.height), expected);
+                assert_eq!(img.data.len(), expected.0 as usize * expected.1 as usize);
+                assert!(img.data.iter().all(|p| *p == [0.0; 4]));
+            }
+        }
+    }
+
     #[test]
     fn crop_and_pad() {
         let mut img = Image::new(4, 3);
diff --git a/crates/export/tests/it/render_settings.rs b/crates/export/tests/it/render_settings.rs
index 465d8e5fe..c2d7dcbfa 100644
--- a/crates/export/tests/it/render_settings.rs
+++ b/crates/export/tests/it/render_settings.rs
@@ -174,6 +174,29 @@ fn crop_roi_and_resize() {
     assert_eq!((z.width(), z.height()), (32, 24));
 }
 
+#[test]
+fn crop_resize_preserves_pixels_when_the_cropped_size_is_requested() {
+    let (p, cid) = project(FrameRate::new(25, 1), |_, _| {});
+    for (crop, scale, expected) in [
+        (Crop { enabled: true, left: 16, right: 16, ..Default::default() }, 1.0, (32, 48)),
+        (Crop { enabled: true, left: -4, top: -2, ..Default::default() }, 1.0, (68, 50)),
+        (Crop { enabled: true, use_roi: true, roi: Some([0.0, 24.0, 32.0, 24.0]), ..Default::default() }, 0.5, (16, 12)),
+        (Crop { enabled: true, use_roi: true, roi: Some([0.0, 24.0, 32.0, 24.0]), ..Default::default() }, 2.0, (64, 48)),
+    ] {
+        let settings = RenderSettings { resolution: scale, ..custom(0.4, 0.44) };
+        let mut output = OutputModule { crop, ..OutputModule::for_format(OutputFormat::PngSequence) };
+        let reference = png(&run(&p, cid, &settings, &output, "/c/reference_[#####].png"), 0);
+        assert_eq!(reference.dimensions(), expected);
+        assert!(reference.pixels().any(|p| p.0[0] > 150), "the reference contains visible content");
+        for quality in [ResizeQuality::Low, ResizeQuality::High] {
+            output.resize = Resize { enabled: true, width: expected.0, height: 1, lock_aspect: true, quality };
+            let actual = png(&run(&p, cid, &settings, &output, "/c/resized_[#####].png"), 0);
+            assert_eq!(actual.dimensions(), expected);
+            assert!(actual == reference, "crop {crop:?}, scale {scale}, quality {quality:?}: pixels changed");
+        }
+    }
+}
+
 #[test]
 fn alpha_only_and_premultiplied() {
     let (p, cid) = project(FrameRate::new(25, 1), |p, comp| {

From 3bc1caaedbf53dac566ecd677b84d9400bae18ae Mon Sep 17 00:00:00 2001
From: Camille Moine <ki2pixel@gmail.com>
Date: Mon, 19 Oct 2026 19:54:11 +0200
Subject: [PATCH 3/8] Shapes: per-corner roundness for Rectangle Path (#1896)

Add Per-Corner Roundness to Rectangle Path: a checkbox (off by default) and four Pixels properties (top-left, top-right, bottom-right, bottom-left). New rectangles initialise the four values from their Roundness, so ticking the box keeps the shape; the radii are animatable and expression-driven.\n\nrect_radii() builds the path clockwise from the top-left with kappa quarter-circle arcs. Overlapping radii scale down like CSS border-radius; negative and non-finite radii are square; rect() delegates to it, so uniform roundness clamps to half the shorter side as before.\n\nLottie rc has one r: four equal static radii export as that value; mixed or animated radii export roundness 0 with a warning. Import puts r into the four per-corner values so ticking the box on an imported rectangle keeps the shape.\n\nTests: path geometry and clamping, rendered per-corner pixels, Lottie equal/mixed/checkbox-off export.
---
 crates/engine/src/cmd/paths.rs                | 65 +++++++++++-----
 crates/engine/src/tests/stubs.rs              | 64 +++++++++++++++
 crates/lottie/src/shapes.rs                   | 22 +++++-
 crates/lottie/src/tests.rs                    | 36 +++++++++
 crates/path/src/lib.rs                        | 77 +++++++++++++++++++
 crates/project/src/build.rs                   |  7 ++
 crates/render/src/shapes.rs                   | 15 +++-
 crates/render/src/shapes/tests.rs             | 30 ++++++++
 crates/ui-egui/src/panels/timeline/tests.rs   |  5 ++
 crates/ui-egui/tests/it/ui_timeline_shapes.rs |  5 ++
 10 files changed, 304 insertions(+), 22 deletions(-)

diff --git a/crates/engine/src/cmd/paths.rs b/crates/engine/src/cmd/paths.rs
index 0bb2eaae2..7cd457640 100644
--- a/crates/engine/src/cmd/paths.rs
+++ b/crates/engine/src/cmd/paths.rs
@@ -5,6 +5,7 @@
 use effectcraft_keyframe::{ShapePath, Value as KV};
 use effectcraft_project::build::{self, Ids};
 use effectcraft_project::{FeatherFalloff, GroupKind, ItemId, LayerId, LayerSource, MaskMotionBlur, Node, PropGroup, Uid};
+use effectcraft_render::EvalCtx;
 use serde_json::{Value, json};
 
 use super::layer_menu::target_masks;
@@ -111,18 +112,30 @@ fn roto_bezier(s: &mut Session, p: &Value) -> Result<Value> {
 /// The parametric shape paths that Convert To Bezier Path replaces with an editable path.
 const PARAMETRIC: [&str; 3] = ["rect", "ellipse", "star"];
 
-/// The path a parametric shape group draws, in the group's own space, read at `lt`. This is the
-/// geometry the renderer builds from the same values (`render::shapes::collect`), so the converted
-/// path is the shape that was on screen rather than an approximation of it; the defaults match
-/// that code for a property a group doesn't carry (a polygon has no inner radius or roundness).
-fn parametric_path(g: &PropGroup, lt: effectcraft_time::Tick) -> Option<ShapePath> {
-    let f = |id: &str, d: f64| g.prop(id).map_or(d, |pr| pr.value_at(lt).as_f64());
-    let v2 = |id: &str, d: [f64; 2]| g.prop(id).map_or(d, |pr| pr.value_at(lt).as_vec2());
+/// The path a parametric shape group draws, in the group's own space. This is the geometry the
+/// renderer builds from the same values (`render::shapes::collect`), expressions included, so the
+/// converted path is the shape that was on screen rather than an approximation of it; the defaults
+/// match that code for a property a group doesn't carry (a polygon has no inner radius or
+/// roundness).
+fn parametric_path(ctx: &EvalCtx, layer: &effectcraft_project::Layer, g: &PropGroup) -> Option<ShapePath> {
+    let f = |id: &str, d: f64| ctx.f(layer, g, id, d);
+    let v2 = |id: &str, d: [f64; 2]| ctx.v2(layer, g, id, d);
     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)),
+        "rect" => {
+            let (size, pos) = (v2("size", [100.0; 2]), v2("position", [0.0; 2]));
+            if ctx.b(layer, g, "perCorner") {
+                effectcraft_path::rect_radii(
+                    size,
+                    pos,
+                    [f("topLeftRoundness", 0.0), f("topRightRoundness", 0.0), f("bottomRightRoundness", 0.0), f("bottomLeftRoundness", 0.0)],
+                )
+            } else {
+                effectcraft_path::rect(size, pos, f("roundness", 0.0))
+            }
+        }
         "ellipse" => effectcraft_path::ellipse(v2("size", [100.0; 2]), v2("position", [0.0; 2])),
         "star" => effectcraft_path::polystar(effectcraft_path::Polystar {
-            star: g.prop("type").map_or(0, |pr| pr.value_at(lt).as_enum()) == 0,
+            star: ctx.e(layer, g, "type") == 0,
             points: f("points", 5.0),
             pos: v2("position", [0.0; 2]),
             rotation: f("rotation", 0.0),
@@ -160,28 +173,40 @@ fn convert_to_bezier(s: &mut Session, p: &Value) -> Result<Value> {
     }
     let t = s.time();
     let n = shapes.len();
+    // Read the geometry before editing, with the same expression-aware context the renderer
+    // uses: an expression-driven corner radius, size or position must convert to what is on
+    // screen, not to the property's underlying value.
+    let expr = s.expr.clone();
+    let prepared = {
+        let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+        let ctx =
+            EvalCtx { project: &s.project, comp_id: cid, comp, time: t, expr: expr.as_deref(), footage: None, property_overrides: &[], media_overrides: &[] };
+        let mut prepared = Vec::new();
+        for (lid, uid) in &shapes {
+            let Some(l) = comp.layer(*lid) else { continue };
+            let Some(old) = l.props.sub("contents").and_then(|c| c.find_group(*uid)) else { continue };
+            let Some(path) = parametric_path(&ctx, l, old) else { continue };
+            // Path Direction is the shape's own, not a default: reversing is a separate command.
+            prepared.push((*lid, *uid, path, ctx.e(l, old, "direction"), old.enabled));
+        }
+        prepared
+    };
     let made = s.edit("Convert To Bezier Path", None, |proj, st| {
         let mut next = proj.next_id;
         let mut made = Vec::new();
-        for (lid, uid) in &shapes {
-            let l = layer_mut(proj, cid, *lid)?;
-            let lt = l.layer_time(t);
+        for (lid, uid, path, direction, enabled) in prepared {
+            let l = layer_mut(proj, cid, lid)?;
             let contents = l.props.sub_mut("contents").ok_or_else(|| bad("path.convertToBezier", "not a shape layer"))?;
-            let Some(old) = contents.find_group(*uid) else { continue };
-            let Some(path) = parametric_path(old, lt) else { continue };
-            // Path Direction is the shape's own, not a default: reversing is a separate command.
-            let direction = old.prop("direction").map_or(0, |pr| pr.value_at(lt).as_enum());
-            let enabled = old.enabled;
             let mut g = build::shape_path(&mut Ids(&mut next), path);
             if let Some(pr) = g.prop_mut("direction") {
                 pr.value = KV::Enum(direction);
             }
             g.enabled = enabled;
             let new_uid = g.uid;
-            let parent = contents.parent_of_mut(*uid).ok_or_else(|| bad("path.convertToBezier", "no such shape item"))?;
-            let Some(at) = parent.children.iter().position(|c| c.uid() == *uid) else { continue };
+            let parent = contents.parent_of_mut(uid).ok_or_else(|| bad("path.convertToBezier", "no such shape item"))?;
+            let Some(at) = parent.children.iter().position(|c| c.uid() == uid) else { continue };
             parent.children[at] = Node::Group(g);
-            made.push((*lid, new_uid));
+            made.push((lid, new_uid));
         }
         proj.next_id = next;
         // The new paths are what is selected, so the vertices can be edited straight away.
diff --git a/crates/engine/src/tests/stubs.rs b/crates/engine/src/tests/stubs.rs
index 9735f2c08..087a4ae1a 100644
--- a/crates/engine/src/tests/stubs.rs
+++ b/crates/engine/src/tests/stubs.rs
@@ -585,6 +585,70 @@ fn convert_to_bezier_reads_the_shape_as_it_is_set() {
     assert!((mid(&xs) - 10.0).abs() < 1e-6 && (mid(&ys) - 5.0).abs() < 1e-6, "centred on the position: {:?} {:?}", mid(&xs), mid(&ys));
 }
 
+/// #1896: Convert To Bezier Path reads Per-Corner Roundness, not just the uniform Roundness, so
+/// the editable path is the shape that was on screen.
+#[test]
+fn convert_to_bezier_honours_per_corner_roundness() {
+    let mut s = comp();
+    let l = s.execute("layer.newShape", json!({"kind": "rect", "size": [120, 80]})).unwrap()["layer"].as_u64().unwrap();
+    let (uid, _) = first_shape(&s, l);
+    let uid_of = |s: &Session, id: &str| layer(s, l).props.sub("contents").unwrap().find_group(uid).unwrap().get(id).unwrap().uid;
+    let per_corner = uid_of(&s, "perCorner");
+    let top_left = uid_of(&s, "topLeftRoundness");
+    let bottom_right = uid_of(&s, "bottomRightRoundness");
+    for (u, v) in [(per_corner, json!(true)), (top_left, json!(20.0)), (bottom_right, json!(10.0))] {
+        s.execute("prop.set", json!({"layer": l, "path": format!("@{u}"), "value": v})).unwrap();
+    }
+
+    s.state.selected_props = vec![(LayerId(l), uid)];
+    s.execute("path.convertToBezier", json!({})).unwrap();
+    let (new_uid, now) = first_shape(&s, l);
+    assert_eq!(now, "path");
+    let path = shape_path_of(&s, l, new_uid);
+    let expected = effectcraft_path::from_kurbo(&effectcraft_path::rect_radii([120.0, 80.0], [0.0, 0.0], [20.0, 0.0, 10.0, 0.0])).into_iter().next().unwrap();
+    assert_eq!(path, expected, "the converted path has the per-corner geometry");
+}
+
+/// #1896: Convert To Bezier Path evaluates the shape's expressions, so an expression-driven
+/// Per-Corner checkbox and radius convert to the geometry on screen.
+#[test]
+fn convert_to_bezier_evaluates_corner_expressions() {
+    struct Corners;
+    impl effectcraft_render::ExprHost for Corners {
+        fn eval(
+            &self,
+            _: &effectcraft_render::EvalCtx,
+            _: &effectcraft_project::Layer,
+            prop: &effectcraft_project::Property,
+            value: &KV,
+        ) -> std::result::Result<KV, String> {
+            Ok(match prop.match_id.as_str() {
+                "perCorner" => KV::Bool(true),
+                "topLeftRoundness" => KV::Scalar(20.0),
+                _ => value.clone(),
+            })
+        }
+    }
+
+    let mut s = comp();
+    s.expr = Some(Arc::new(Corners));
+    let l = s.execute("layer.newShape", json!({"kind": "rect", "size": [120, 80]})).unwrap()["layer"].as_u64().unwrap();
+    let (uid, _) = first_shape(&s, l);
+    let uid_of = |s: &Session, id: &str| layer(s, l).props.sub("contents").unwrap().find_group(uid).unwrap().get(id).unwrap().uid;
+    for (id, expression) in [("perCorner", "true"), ("topLeftRoundness", "20")] {
+        let u = uid_of(&s, id);
+        s.execute("prop.setExpression", json!({"layer": l, "path": format!("@{u}"), "expression": expression})).unwrap();
+    }
+
+    s.state.selected_props = vec![(LayerId(l), uid)];
+    s.execute("path.convertToBezier", json!({})).unwrap();
+    let (new_uid, now) = first_shape(&s, l);
+    assert_eq!(now, "path");
+    let path = shape_path_of(&s, l, new_uid);
+    let expected = effectcraft_path::from_kurbo(&effectcraft_path::rect_radii([120.0, 80.0], [0.0, 0.0], [20.0, 0.0, 0.0, 0.0])).into_iter().next().unwrap();
+    assert_eq!(path, expected, "the expression-evaluated corner is converted");
+}
+
 /// #2201: a viewer drag on the free-transform box sends one `path.freeTransform` per frame with a
 /// shared merge key; one undo must revert the whole drag, not the last frame.
 #[test]
diff --git a/crates/lottie/src/shapes.rs b/crates/lottie/src/shapes.rs
index 990a0f28b..fc823b775 100644
--- a/crates/lottie/src/shapes.rs
+++ b/crates/lottie/src/shapes.rs
@@ -113,6 +113,9 @@ impl Out<'_, '_> {
     fn f(&self, m: &str) -> f64 {
         self.g.get(m).map(|p| p.value.as_f64()).unwrap_or(0.0)
     }
+    fn flag(&self, m: &str) -> bool {
+        self.g.get(m).map(|p| p.value.as_bool()).unwrap_or(false)
+    }
     fn animated(&self, m: &str) -> bool {
         self.g.get(m).is_some_and(|p| p.is_animated() || p.has_expression())
     }
@@ -232,7 +235,19 @@ pub(crate) fn export_items(ex: &mut Ex, contents: &PropGroup, label: &str) -> Ve
                 dir(&mut o);
                 o.put("s", "size", &anim::arr2);
                 o.put("p", "position", &anim::arr2);
-                o.put("r", "roundness", &anim::num);
+                if o.flag("perCorner") {
+                    let names = ["topLeftRoundness", "topRightRoundness", "bottomRightRoundness", "bottomLeftRoundness"];
+                    let radii = names.map(|m| o.f(m));
+                    // Lottie `rc` has one `r`: four equal static radii export as that value.
+                    if radii.iter().all(|v| (v - radii[0]).abs() < 1e-6) && !names.iter().any(|m| o.animated(m)) && radii[0] >= 0.0 {
+                        o.raw("r", json!(r(radii[0])));
+                    } else {
+                        o.ex.warn(format!("{}: per-corner roundness has no Lottie rectangle equivalent (roundness 0 exported)", o.label));
+                        o.raw("r", json!(0));
+                    }
+                } else {
+                    o.put("r", "roundness", &anim::num);
+                }
             }
             "el" => {
                 dir(&mut o);
@@ -447,6 +462,11 @@ pub(crate) fn import_items(im: &mut Im, ids: &mut Ids, items: &[Json]) -> Vec<Pr
                 set(im, &mut g, "size", j.get("s"), &anim::to_vec2);
                 set(im, &mut g, "position", j.get("p"), &anim::to_vec2);
                 set(im, &mut g, "roundness", j.get("r"), &anim::to_scalar);
+                // Lottie has one roundness: keep the per-corner values in step so ticking the box
+                // on an imported rectangle keeps the shape.
+                for m in ["topLeftRoundness", "topRightRoundness", "bottomRightRoundness", "bottomLeftRoundness"] {
+                    set(im, &mut g, m, j.get("r"), &anim::to_scalar);
+                }
                 g
             }
             "el" => {
diff --git a/crates/lottie/src/tests.rs b/crates/lottie/src/tests.rs
index 203f04c04..24b4690eb 100644
--- a/crates/lottie/src/tests.rs
+++ b/crates/lottie/src/tests.rs
@@ -896,3 +896,39 @@ fn muted_keys_are_omitted_from_the_export() {
     assert!((opacity_at(&p, cid, 1.0) - 150.0).abs() < 1e-6);
     assert!((opacity_at(&q, nc, 1.0) - 150.0).abs() < 1e-6);
 }
+
+#[test]
+fn per_corner_roundness_exports_equal_radii_and_warns_when_mixed() {
+    let shape = |radii: [f64; 4], roundness: f64, per_corner: bool| {
+        let (mut p, cid) = setup();
+        let l = shape_layer(&mut p, cid, move |ids| {
+            let mut g = build::shape_rect(ids, [100.0, 50.0], [0.0, 0.0], roundness);
+            g.prop_mut("perCorner").unwrap().value = Value::Bool(per_corner);
+            for (m, v) in
+                [("topLeftRoundness", radii[0]), ("topRightRoundness", radii[1]), ("bottomRightRoundness", radii[2]), ("bottomLeftRoundness", radii[3])]
+            {
+                g.prop_mut(m).unwrap().value = Value::Scalar(v);
+            }
+            let fill = build::shape_fill(ids, [1.0, 0.0, 0.0, 1.0]);
+            vec![build::shape_group(ids, "Rectangle 1", vec![g, fill])]
+        });
+        push(&mut p, cid, l);
+        (p, cid)
+    };
+    let rc = |json: &Json| -> Json { json["layers"][0]["shapes"][0]["it"].as_array().unwrap().iter().find(|i| i["ty"] == "rc").cloned().unwrap() };
+    // Four equal static radii: `rc.r` carries the value, no warning.
+    let (p, cid) = shape([12.0; 4], 5.0, true);
+    let (_, _, warnings, json) = roundtrip(&p, cid, &ExportOptions::default());
+    assert_eq!(rc(&json)["r"], json!(12.0));
+    assert!(!warnings.iter().any(|w| w.contains("per-corner")), "{warnings:?}");
+    // Mixed radii: not representable, roundness 0 exported with a warning.
+    let (p, cid) = shape([10.0, 20.0, 10.0, 20.0], 5.0, true);
+    let (_, _, warnings, json) = roundtrip(&p, cid, &ExportOptions::default());
+    assert_eq!(rc(&json)["r"], json!(0));
+    assert!(warnings.iter().any(|w| w.contains("per-corner roundness")), "{warnings:?}");
+    // The checkbox off exports the single Roundness and ignores the four values.
+    let (p, cid) = shape([10.0, 20.0, 10.0, 20.0], 5.0, false);
+    let (_, _, warnings, json) = roundtrip(&p, cid, &ExportOptions::default());
+    assert_eq!(rc(&json)["r"]["k"], json!(5.0));
+    assert!(!warnings.iter().any(|w| w.contains("per-corner")), "{warnings:?}");
+}
diff --git a/crates/path/src/lib.rs b/crates/path/src/lib.rs
index 83e2102dc..61fd0e6c3 100644
--- a/crates/path/src/lib.rs
+++ b/crates/path/src/lib.rs
@@ -164,6 +164,52 @@ pub fn rect(size: [f64; 2], pos: [f64; 2], roundness: f64) -> BezPath {
     p
 }
 
+/// Rectangle path centred at `pos` with independent corner radii `[top-left, top-right,
+/// bottom-right, bottom-left]`, clockwise in screen coordinates. Negative and non-finite radii
+/// are 0; radii that would overlap are scaled down as CSS `border-radius` does.
+pub fn rect_radii(size: [f64; 2], pos: [f64; 2], radii: [f64; 4]) -> BezPath {
+    // Start at the end of the top-right arc on the right edge, like `rect`, and walk the corners
+    // clockwise: Trim Paths measures from the first point, so ticking per-corner roundness must
+    // not make a trim jump (#1896).
+    let w = if size[0].is_finite() { size[0].abs() } else { 0.0 };
+    let h = if size[1].is_finite() { size[1].abs() } else { 0.0 };
+    let (x0, y0) = (pos[0] - w / 2.0, pos[1] - h / 2.0);
+    let (x1, y1) = (pos[0] + w / 2.0, pos[1] + h / 2.0);
+    let mut r = radii.map(|v| if v.is_finite() { v.max(0.0) } else { 0.0 });
+    // CSS border-radius: when two radii on an edge overlap, scale every radius by the smallest
+    // edge ratio (a uniform radius then clamps to half the shorter side, as before).
+    let ratio = |a: f64, b: f64, edge: f64| if a + b > edge && a + b > 0.0 { (edge / (a + b)).min(1.0) } else { 1.0 };
+    let f = ratio(r[0], r[1], w).min(ratio(r[3], r[2], w)).min(ratio(r[0], r[3], h)).min(ratio(r[1], r[2], h));
+    if f < 1.0 {
+        for v in &mut r {
+            *v *= f;
+        }
+    }
+    let [tl, tr, br, bl] = r;
+    // Quarter-circle Bezier control distance.
+    const K: f64 = 0.552_284_749_830_793_6;
+    let mut p = BezPath::new();
+    p.move_to((x1, y0 + tr));
+    p.line_to((x1, y1 - br));
+    if br > 0.0 {
+        p.curve_to((x1, y1 - br + K * br), (x1 - br + K * br, y1), (x1 - br, y1));
+    }
+    p.line_to((x0 + bl, y1));
+    if bl > 0.0 {
+        p.curve_to((x0 + bl - K * bl, y1), (x0, y1 - bl + K * bl), (x0, y1 - bl));
+    }
+    p.line_to((x0, y0 + tl));
+    if tl > 0.0 {
+        p.curve_to((x0, y0 + tl - K * tl), (x0 + tl - K * tl, y0), (x0 + tl, y0));
+    }
+    p.line_to((x1 - tr, y0));
+    if tr > 0.0 {
+        p.curve_to((x1 - tr + K * tr, y0), (x1, y0 + tr - K * tr), (x1, y0 + tr));
+    }
+    p.close_path();
+    p
+}
+
 pub fn ellipse(size: [f64; 2], pos: [f64; 2]) -> BezPath {
     to_kurbo(&ShapePath::ellipse(pos, size[0], size[1]))
 }
@@ -419,6 +465,11 @@ mod tests {
         let round = ops::trim(&[rect([400.0, 300.0], [0.0, 0.0], 40.0)], 0.0, 25.0, 0.0);
         let (a, b) = ends(&round[0]);
         assert!(near(a, (200.0, -110.0)) && near(b, (110.0, 150.0)), "{a:?} {b:?}");
+        // Per-corner roundness starts and runs in the same order: ticking the checkbox must not
+        // move a Trim Paths contour.
+        let corners = ops::trim(&[rect_radii([400.0, 300.0], [0.0, 0.0], [40.0; 4])], 0.0, 25.0, 0.0);
+        let (a, b) = ends(&corners[0]);
+        assert!(near(a, (200.0, -110.0)) && near(b, (110.0, 150.0)), "per-corner: {a:?} {b:?}");
         // Start > End: AE draws 30..70 % (plain: from x 80 on the bottom up to y −130 on the left).
         let swapped = ops::trim(&[rect([400.0, 300.0], [0.0, 0.0], 0.0)], 70.0, 30.0, 0.0);
         let (a, b) = ends(&swapped[0]);
@@ -456,6 +507,32 @@ mod tests {
         assert!((area - 200.0).abs() < 1.0, "{area}");
     }
 
+    #[test]
+    fn rect_radii_uniform_matches_a_rounded_rect() {
+        for r in [0.0, 5.0, 25.0, 100.0] {
+            let p = rect_radii([100.0, 50.0], [10.0, 20.0], [r; 4]);
+            let clamped = r.min(25.0);
+            let expect = 100.0 * 50.0 - (4.0 - std::f64::consts::PI) * clamped * clamped;
+            assert!((p.area().abs() - expect).abs() < 1.0, "{r}: {} != {expect}", p.area());
+            assert!((p.area() - rect([100.0, 50.0], [10.0, 20.0], r).area()).abs() < 1e-6);
+        }
+    }
+
+    #[test]
+    fn rect_radii_mixes_corners_and_scales_overlaps() {
+        // Only the top-left and bottom-right corners round.
+        let p = rect_radii([100.0, 50.0], [0.0, 0.0], [10.0, 0.0, 20.0, 0.0]);
+        let expect = 100.0 * 50.0 - (1.0 - std::f64::consts::PI / 4.0) * (10.0 * 10.0 + 20.0 * 20.0);
+        assert!((p.area().abs() - expect).abs() < 1.0, "{}", p.area());
+        // Radii wider than the top edge scale down together, like CSS border-radius.
+        let p = rect_radii([50.0, 100.0], [0.0, 0.0], [40.0, 40.0, 0.0, 0.0]);
+        let scaled = rect_radii([50.0, 100.0], [0.0, 0.0], [25.0, 25.0, 0.0, 0.0]);
+        assert!((p.area() - scaled.area()).abs() < 1e-9);
+        // Negative and non-finite radii are square corners.
+        let p = rect_radii([50.0, 50.0], [0.0, 0.0], [-5.0, f64::NAN, f64::INFINITY, 0.0]);
+        assert!((p.area().abs() - 2500.0).abs() < 1e-9);
+    }
+
     #[test]
     fn stroke_has_area() {
         let r = rect([40.0, 40.0], [50.0, 50.0], 0.0);
diff --git a/crates/project/src/build.rs b/crates/project/src/build.rs
index 3ff61ba7d..1aa8d7c90 100644
--- a/crates/project/src/build.rs
+++ b/crates/project/src/build.rs
@@ -385,11 +385,18 @@ pub fn shape_group(ids: &mut Ids, name: &str, items: Vec<PropGroup>) -> PropGrou
 }
 
 pub fn shape_rect(ids: &mut Ids, size: [f64; 2], position: [f64; 2], roundness: f64) -> PropGroup {
+    // Per-corner radii start from the uniform Roundness, so ticking the box keeps the shape.
+    let r = if roundness.is_finite() { roundness.max(0.0) } else { 0.0 };
     indexed(ids.group("rect", "Rectangle Path 1"))
         .with(ids.prop("direction", "Path Direction", Value::Enum(0)).with_ui(ParamUi::Hidden))
         .with(ids.prop("size", "Size", Value::Vec2(size)).with_ui(ParamUi::Pixels))
         .with(ids.prop("position", "Position", Value::Vec2(position)).with_ui(ParamUi::Point))
         .with(ids.prop("roundness", "Roundness", Value::Scalar(roundness)).with_ui(ParamUi::Pixels))
+        .with(ids.prop("perCorner", "Per-Corner Roundness", Value::Bool(false)).with_ui(ParamUi::Checkbox))
+        .with(ids.prop("topLeftRoundness", "Top Left Roundness", Value::Scalar(r)).with_ui(ParamUi::Pixels))
+        .with(ids.prop("topRightRoundness", "Top Right Roundness", Value::Scalar(r)).with_ui(ParamUi::Pixels))
+        .with(ids.prop("bottomRightRoundness", "Bottom Right Roundness", Value::Scalar(r)).with_ui(ParamUi::Pixels))
+        .with(ids.prop("bottomLeftRoundness", "Bottom Left Roundness", Value::Scalar(r)).with_ui(ParamUi::Pixels))
 }
 
 pub fn shape_ellipse(ids: &mut Ids, size: [f64; 2], position: [f64; 2]) -> PropGroup {
diff --git a/crates/render/src/shapes.rs b/crates/render/src/shapes.rs
index bbc4283ff..2497ea807 100644
--- a/crates/render/src/shapes.rs
+++ b/crates/render/src/shapes.rs
@@ -269,7 +269,20 @@ fn collect_in(ctx: &EvalCtx, layer: &Layer, contents: &PropGroup, arena: &mut Ve
             "rect" => {
                 let size = ctx.v2(layer, g, "size", [100.0; 2]);
                 let pos = ctx.v2(layer, g, "position", [0.0; 2]);
-                let p = effectcraft_path::rect(size, pos, ctx.f(layer, g, "roundness", 0.0));
+                let p = if ctx.b(layer, g, "perCorner") {
+                    effectcraft_path::rect_radii(
+                        size,
+                        pos,
+                        [
+                            ctx.f(layer, g, "topLeftRoundness", 0.0),
+                            ctx.f(layer, g, "topRightRoundness", 0.0),
+                            ctx.f(layer, g, "bottomRightRoundness", 0.0),
+                            ctx.f(layer, g, "bottomLeftRoundness", 0.0),
+                        ],
+                    )
+                } else {
+                    effectcraft_path::rect(size, pos, ctx.f(layer, g, "roundness", 0.0))
+                };
                 push_shape(ctx, layer, g, p, arena, &mut live);
             }
             "ellipse" => {
diff --git a/crates/render/src/shapes/tests.rs b/crates/render/src/shapes/tests.rs
index e0c9086a7..ba7028a25 100644
--- a/crates/render/src/shapes/tests.rs
+++ b/crates/render/src/shapes/tests.rs
@@ -715,3 +715,33 @@ fn miter_corner_still_fits_its_buffer() {
     let b = shape_buf(&p, cid);
     assert!(b.img.height as f64 >= 50.0 + 20.0 * 4.0 * 0.5, "{}", b.img.height);
 }
+
+#[test]
+fn rect_per_corner_roundness_rounds_the_named_corners() {
+    let render = |per_corner: bool, radii: [f64; 4], roundness: f64| {
+        let (p, cid) = shape_comp_sized(200, 100, move |ids| {
+            let mut g = build::shape_rect(ids, [100.0, 100.0], [0.0, 0.0], roundness);
+            g.prop_mut("perCorner").unwrap().value = Value::Bool(per_corner);
+            for (m, v) in
+                [("topLeftRoundness", radii[0]), ("topRightRoundness", radii[1]), ("bottomRightRoundness", radii[2]), ("bottomLeftRoundness", radii[3])]
+            {
+                g.prop_mut(m).unwrap().value = Value::Scalar(v);
+            }
+            vec![g, build::shape_fill(ids, RED)]
+        });
+        frame(&p, cid)
+    };
+    // Only the top-left corner rounds: its corner pixels fade, the other three stay filled.
+    let img = render(true, [30.0, 0.0, 0.0, 0.0], 0.0);
+    assert!(alpha(&img, 52, 2) < 0.1, "top-left rounds: {}", alpha(&img, 52, 2));
+    for (x, y) in [(148, 2), (148, 98), (52, 98)] {
+        assert!(alpha(&img, x, y) > 0.9, "({x},{y}) stays square: {}", alpha(&img, x, y));
+    }
+    // The checkbox off ignores the four values (the single Roundness still rules).
+    let off = render(false, [30.0; 4], 0.0);
+    assert!((coverage(&off) - 100.0 * 100.0).abs() < 20.0, "{}", coverage(&off));
+    // Four equal per-corner radii render like the same Roundness.
+    let per = render(true, [25.0; 4], 0.0);
+    let uni = render(false, [0.0; 4], 25.0);
+    assert!((coverage(&per) - coverage(&uni)).abs() < 5.0, "{} vs {}", coverage(&per), coverage(&uni));
+}
diff --git a/crates/ui-egui/src/panels/timeline/tests.rs b/crates/ui-egui/src/panels/timeline/tests.rs
index 12259abf7..9a5c89f7d 100644
--- a/crates/ui-egui/src/panels/timeline/tests.rs
+++ b/crates/ui-egui/src/panels/timeline/tests.rs
@@ -195,6 +195,11 @@ fn shape_group_inner_contents_is_elided() {
             "        Size",
             "        Position",
             "        Roundness",
+            "        Per-Corner Roundness",
+            "        Top Left Roundness",
+            "        Top Right Roundness",
+            "        Bottom Right Roundness",
+            "        Bottom Left Roundness",
             "      >Fill 1",
             "        Composite",
             "        Fill Rule",
diff --git a/crates/ui-egui/tests/it/ui_timeline_shapes.rs b/crates/ui-egui/tests/it/ui_timeline_shapes.rs
index 73686ee99..cd56db825 100644
--- a/crates/ui-egui/tests/it/ui_timeline_shapes.rs
+++ b/crates/ui-egui/tests/it/ui_timeline_shapes.rs
@@ -340,6 +340,11 @@ fn timeline_colour_eyedropper_samples_the_comp() {
     let fill = fill.expect("a fill colour");
     fn groups(g: &effectcraft_engine::project::PropGroup, out: &mut Vec<u64>) {
         for c in g.groups() {
+            // The rectangle's path rows would push Fill below the rows the Timeline fits; the
+            // eyedropper only needs Fill, so leave that group collapsed.
+            if c.name == "Rectangle Path 1" {
+                continue;
+            }
             out.push(c.uid);
             groups(c, out);
         }

From d249f255ae7852e23f285a473640b9720cf1819e Mon Sep 17 00:00:00 2001
From: Camille Moine <ki2pixel@gmail.com>
Date: Mon, 19 Oct 2026 21:08:54 +0200
Subject: [PATCH 4/8] Shapes: export per-corner `rc.r` as a Lottie property

The equal-radii and zero fallback branches wrote a bare number where the
uniform branch (and every other Value field) writes `{a, k}`; external
players may reject that form even though our importer reads it. Write
`{"a": 0, "k": value}` in both branches and update the export assertions.
---
 crates/lottie/src/shapes.rs | 5 +++--
 crates/lottie/src/tests.rs  | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/crates/lottie/src/shapes.rs b/crates/lottie/src/shapes.rs
index fc823b775..5b9d29970 100644
--- a/crates/lottie/src/shapes.rs
+++ b/crates/lottie/src/shapes.rs
@@ -239,11 +239,12 @@ pub(crate) fn export_items(ex: &mut Ex, contents: &PropGroup, label: &str) -> Ve
                     let names = ["topLeftRoundness", "topRightRoundness", "bottomRightRoundness", "bottomLeftRoundness"];
                     let radii = names.map(|m| o.f(m));
                     // Lottie `rc` has one `r`: four equal static radii export as that value.
+                    // `r` is a property (`{a, k}`) like the uniform branch writes, not a bare number.
                     if radii.iter().all(|v| (v - radii[0]).abs() < 1e-6) && !names.iter().any(|m| o.animated(m)) && radii[0] >= 0.0 {
-                        o.raw("r", json!(r(radii[0])));
+                        o.raw("r", json!({"a": 0, "k": r(radii[0])}));
                     } else {
                         o.ex.warn(format!("{}: per-corner roundness has no Lottie rectangle equivalent (roundness 0 exported)", o.label));
-                        o.raw("r", json!(0));
+                        o.raw("r", json!({"a": 0, "k": 0}));
                     }
                 } else {
                     o.put("r", "roundness", &anim::num);
diff --git a/crates/lottie/src/tests.rs b/crates/lottie/src/tests.rs
index 24b4690eb..83c81e242 100644
--- a/crates/lottie/src/tests.rs
+++ b/crates/lottie/src/tests.rs
@@ -919,12 +919,12 @@ fn per_corner_roundness_exports_equal_radii_and_warns_when_mixed() {
     // Four equal static radii: `rc.r` carries the value, no warning.
     let (p, cid) = shape([12.0; 4], 5.0, true);
     let (_, _, warnings, json) = roundtrip(&p, cid, &ExportOptions::default());
-    assert_eq!(rc(&json)["r"], json!(12.0));
+    assert_eq!(rc(&json)["r"], json!({"a": 0, "k": 12.0}));
     assert!(!warnings.iter().any(|w| w.contains("per-corner")), "{warnings:?}");
     // Mixed radii: not representable, roundness 0 exported with a warning.
     let (p, cid) = shape([10.0, 20.0, 10.0, 20.0], 5.0, true);
     let (_, _, warnings, json) = roundtrip(&p, cid, &ExportOptions::default());
-    assert_eq!(rc(&json)["r"], json!(0));
+    assert_eq!(rc(&json)["r"], json!({"a": 0, "k": 0}));
     assert!(warnings.iter().any(|w| w.contains("per-corner roundness")), "{warnings:?}");
     // The checkbox off exports the single Roundness and ignores the four values.
     let (p, cid) = shape([10.0, 20.0, 10.0, 20.0], 5.0, false);

From 5bb66bad745fcec1f68e0f6a28a7697ba596aec1 Mon Sep 17 00:00:00 2001
From: bflatastic <bombayapirat@gmail.com>
Date: Fri, 30 Oct 2026 07:37:19 +0700
Subject: [PATCH 5/8] ScriptUI: a docked panel gets its dock's size and
 onResize (#2585)

A docked ScriptUI panel only ever saw its preferredSize: the host drew
it in a scroll area at max(dock, preferred) and the script's window never
learned the dock. scriptui.resize now gives a window a size: the script's
window takes it, lays itself out again and runs onResizing / onResize.
The dock host sends it whenever the panel's dock size changes, so
window.size is the dock's, as in After Effects.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 crates/engine/src/cmd/scripts.rs           |  9 ++++++
 crates/engine/src/scriptui.rs              | 11 ++++++++
 crates/script/src/scriptui.js              | 12 ++++++++
 crates/ui-egui/src/panels/scriptui_view.rs | 11 ++++++++
 crates/ui-egui/tests/it/ui_scriptui.rs     | 32 ++++++++++++++++++++++
 5 files changed, 75 insertions(+)

diff --git a/crates/engine/src/cmd/scripts.rs b/crates/engine/src/cmd/scripts.rs
index a523770e3..a92d484a7 100644
--- a/crates/engine/src/cmd/scripts.rs
+++ b/crates/engine/src/cmd/scripts.rs
@@ -467,6 +467,15 @@ pub fn specs() -> Vec<CommandSpec> {
             always,
             scriptui::mouse
         ),
+        cmd!(
+            "scriptui.resize",
+            "Resize Script Window",
+            [],
+            None,
+            "{window?, size: [width, height] (pixels)} → the window takes the size, lays itself out again and its onResizing / onResize run (a docked ScriptUI panel gets its dock's size)",
+            always,
+            scriptui::resize
+        ),
         cmd!(
             "scriptui.close",
             "Close Script Window",
diff --git a/crates/engine/src/scriptui.rs b/crates/engine/src/scriptui.rs
index af89932fa..d8f9f1d1e 100644
--- a/crates/engine/src/scriptui.rs
+++ b/crates/engine/src/scriptui.rs
@@ -765,6 +765,17 @@ pub(crate) fn mouse(s: &mut Session, p: &Value) -> Result<Value> {
     dispatch(s, ScriptUiEvent { window, widget, kind: (*ty).to_string(), value })
 }
 
+/// `scriptui.resize`: the host gave the window a new size (a docked panel's dock, #2585): the
+/// script's window takes it, lays itself out again and gets `onResizing` / `onResize`.
+pub(crate) fn resize(s: &mut Session, p: &Value) -> Result<Value> {
+    let c = "scriptui.resize";
+    let window = window_p(s, p, c)?;
+    let size = p.get("size").and_then(Value::as_array).ok_or_else(|| crate::commands::bad(c, "missing `size` [width, height]"))?;
+    let side = |i: usize| size.get(i).and_then(Value::as_f64).filter(|v| v.is_finite()).map(|v| v.round().clamp(1.0, 16384.0));
+    let (Some(w), Some(h)) = (side(0), side(1)) else { return Err(crate::commands::bad(c, "`size` must be [width, height] in pixels")) };
+    dispatch(s, ScriptUiEvent { window, widget: 0, kind: "resize".into(), value: json!([w, h]) })
+}
+
 /// `scriptui.close`: close a window (a dialog's `show()` returns `result`, default 2 = Cancel).
 pub(crate) fn close(s: &mut Session, p: &Value) -> Result<Value> {
     let window = window_p(s, p, "scriptui.close")?;
diff --git a/crates/script/src/scriptui.js b/crates/script/src/scriptui.js
index 178bd8be1..ddfbc1f3e 100644
--- a/crates/script/src/scriptui.js
+++ b/crates/script/src/scriptui.js
@@ -912,6 +912,18 @@ function __uiDispatch(winId, id, kind, valueJson) {
     w.close(v === null ? 2 : v);
     return;
   }
+  // The host gave the window a new size (a docked panel's dock): take it, lay out, tell the script.
+  if (kind === "resize") {
+    var nw = Number(v && v[0]), nh = Number(v && v[1]);
+    var b = w.__ub || w.__lb;
+    if (nw > 0 && nh > 0 && (b[2] - b[0] !== nw || b[3] - b[1] !== nh)) {
+      w.__ub = [b[0], b[1], b[0] + nw, b[1] + nh];
+      __uiLayout(w);
+      w.__fire("onResizing");
+      w.__fire("onResize");
+    }
+    return;
+  }
   var c = __uiFind(w, id);
   if (!c || c.enabled === false) return;
   var radio = function () {
diff --git a/crates/ui-egui/src/panels/scriptui_view.rs b/crates/ui-egui/src/panels/scriptui_view.rs
index 14460ed28..753b2884e 100644
--- a/crates/ui-egui/src/panels/scriptui_view.rs
+++ b/crates/ui-egui/src/panels/scriptui_view.rs
@@ -26,6 +26,8 @@ enum Act {
     Close(u32),
     /// A mouse event (`scriptui.mouse` parameters without window and widget).
     Mouse(u32, u32, Value),
+    /// A docked panel's new size (`scriptui.resize`).
+    Resize(u32, [f32; 2]),
 }
 
 fn rect_of(origin: egui::Pos2, b: [f64; 4]) -> Rect {
@@ -500,6 +502,7 @@ fn perform(app: &mut EffectcraftApp, ctx: &egui::Context, acts: Vec<Act>) {
             Act::Set(w, id, v) => ("scriptui.set", json!({"window": w, "widget": id, "value": v})),
             Act::Changing(w, id, v) => ("scriptui.set", json!({"window": w, "widget": id, "value": v, "changing": true})),
             Act::Close(w) => ("scriptui.close", json!({"window": w})),
+            Act::Resize(w, [x, y]) => ("scriptui.resize", json!({"window": w, "size": [x, y]})),
             Act::Mouse(w, id, mut v) => {
                 if let Some(o) = v.as_object_mut() {
                     o.insert("window".into(), json!(w));
@@ -582,6 +585,14 @@ pub fn panel(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect, id: u32) {
     // A modal script dialog blocks the panels too.
     let modal = app.session.script_ui.windows.iter().any(|w| w.modal);
     let mut acts = vec![];
+    // The script learns its dock's size when it changes (#2585), as After Effects tells a
+    // docked panel: its window takes the size and onResize runs.
+    let dock = [rect.width().round(), rect.height().round()];
+    let told = egui::Id::unique(("scriptui-dock-size", id));
+    if ui.data(|d| d.get_temp::<[f32; 2]>(told)) != Some(dock) && dock[0] >= 1.0 && dock[1] >= 1.0 {
+        ui.data_mut(|d| d.insert_temp(told, dock));
+        acts.push(Act::Resize(id, dock));
+    }
     let content = rect;
     egui::ScrollArea::both().id_salt(("scriptui-panel", id)).max_width(content.width()).max_height(content.height()).show(ui, |ui| {
         let (r, _) = ui.allocate_exact_size(vec2(w.root.bounds[2] as f32, w.root.bounds[3] as f32), Sense::hover());
diff --git a/crates/ui-egui/tests/it/ui_scriptui.rs b/crates/ui-egui/tests/it/ui_scriptui.rs
index 2669a2631..8a248155b 100644
--- a/crates/ui-egui/tests/it/ui_scriptui.rs
+++ b/crates/ui-egui/tests/it/ui_scriptui.rs
@@ -305,6 +305,38 @@ fn a_drag_keeps_its_control_past_the_window_edge() {
     h.state_mut().session.execute("scriptui.close", json!({})).unwrap();
 }
 
+/// #2585: a window the host resizes takes the size, lays out again and runs onResize; a docked
+/// ScriptUI panel gets its dock's size that way.
+#[test]
+fn script_windows_learn_the_size_they_are_given() {
+    let mut h = harness();
+    let code = r#"
+      var w = new Window("palette", "Sized");
+      var log = w.add("statictext", undefined, "", { name: "log" });
+      log.preferredSize = [200, 20];
+      w.onResize = function () { log.text = "resized " + w.size.width + "x" + w.size.height; };
+      w.show();
+    "#;
+    let r = h.state_mut().session.execute("script.run", json!({"code": code, "name": "sized.jsx"})).unwrap();
+    assert_eq!(r["ok"], true, "{r}");
+    h.run_steps(2);
+    h.state_mut().session.execute("scriptui.resize", json!({"window": "Sized", "size": [300, 180]})).unwrap();
+    let win = h.state().session.script_ui.windows[0].clone();
+    assert_eq!(win.root.lookup(&json!("log")).unwrap().text, "resized 300x180");
+    let list = h.state_mut().session.execute("scriptui.list", json!({})).unwrap();
+    assert_eq!(list[0]["size"], json!([300.0, 180.0]), "{list}");
+    assert!(h.state_mut().session.execute("scriptui.resize", json!({"window": "Sized", "size": ["wide", 1]})).is_err());
+    h.state_mut().session.execute("scriptui.close", json!({})).unwrap();
+    // A docked panel: its window is its dock's size, not its preferred size.
+    h.state_mut().session.execute("window.scriptPanel", json!({"name": "Layer Tools.jsx"})).unwrap();
+    h.run_steps(4);
+    let panel = h.state().session.script_ui.windows.iter().find(|w| w.script == "Layer Tools.jsx").unwrap().clone();
+    let dock = rect(&h, &format!("scriptui.{}", panel.id));
+    assert_eq!([panel.root.bounds[2].round(), panel.root.bounds[3].round()], [dock.width().round() as f64, dock.height().round() as f64]);
+    h.state_mut().close_panel(PanelKind::ScriptPanel(panel.id));
+    h.run_steps(2);
+}
+
 fn click_at(h: &mut Harness<'_, EffectcraftApp>, c: egui::Pos2) {
     h.input_mut().events.push(Event::PointerMoved(c));
     h.run_steps(1);

From df21aff0d80ab36583cb3cae3a5cf447902cb95d Mon Sep 17 00:00:00 2001
From: bflatastic <bombayapirat@gmail.com>
Date: Fri, 30 Oct 2026 07:46:50 +0700
Subject: [PATCH 6/8] Docs: ROADMAP progress log and ScriptUI parity for 30
 October's features

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 ROADMAP.md               | 11 ++++++++++-
 docs/scripting-parity.md |  2 +-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/ROADMAP.md b/ROADMAP.md
index f3e6750ed..740ec6010 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -2,7 +2,7 @@
 
 **Stage: alpha** · next: beta, ~30 points of "ready for real work" and ~350–620 h away
 
-> **Last reviewed:** 2026-10-22 · **Last updated:** 2026-10-30 · **Change:** minor (localization: 303 more panel/dialog rows in Japanese and the Chinese catalogs; recounted after #1774: Japanese 27% → 46%, Simplified Chinese 29% → 46%, Traditional Chinese 29% → 38%, overall 18% → 24%) · **Target:** Adobe After Effects 2026 (26.5.0.89)
+> **Last reviewed:** 2026-10-22 · **Last updated:** 2026-10-30 · **Change:** minor (features of 30 October in the progress log: text Line Join, Timeline drag-reorder and multi-select of effects, viewer edge pan, ScriptUI drag capture and dock size; previously: localization recount after #1774) · **Target:** Adobe After Effects 2026 (26.5.0.89)
 
 EffectCraft aims to do what After Effects does, with the same panels, menus and behaviour, written
 from scratch in Rust. This page is the one-page summary; the evidence is in
@@ -117,6 +117,14 @@ Come tell us what matters most to you on [Discord](https://discord.gg/artcraft).
 
 ## Progress log
 
+- 2026-10-30: Text strokes take a Line Join (Miter, Round or Bevel) in the Character panel,
+  Miter for new text as in After Effects (#2077). In the Timeline, effects, masks and shape items
+  drag to a new place in their stack (#2210) and Shift-click adds them to the selection, so one
+  animation preset can hold several (#2552). The Composition panel pans while a mask vertex is
+  held at its edge (#999). Effect buffers that pad a small layer stay within a memory budget
+  (#2261); an MP4 lasts as long as its edit list shows (#2592); the Render Queue's times tick
+  between frames (#2593). ScriptUI drags keep their control past the window edge with
+  `MouseEvent.buttons` (#2584), and docked panels get their dock's size and `onResize` (#2585).
 - 2026-10-28: A shape layer's Rectangle and Ellipse Size get the Constrain Proportions chain
   that Scale has, so a circle stays a circle while its size is typed, scrubbed or keyed; it
   starts off, so existing shapes behave as before (#2489).
@@ -169,6 +177,7 @@ Come tell us what matters most to you on [Discord](https://discord.gg/artcraft).
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-30 | minor | Progress log: text Line Join, Timeline drag-reorder and Shift multi-select of effects, viewer edge pan, effect padding budget, MP4 edit-list duration, Render Queue clock, ScriptUI drag capture and docked-panel size |
 | 2026-10-22 | minor | Localization: 300 more panel/dialog rows in Japanese and the Chinese catalogs, plus the review's three missing rows (Basic, Advanced, Play/Stop) — panel tabs, form and dialog labels, context menus, tracker/graph/text-panel controls, File-panel footers, credits; language shares recounted after #1774 (Japanese 27% → 46% with 297 effect names, Simplified Chinese 29% → 46% with 307 effect names, Traditional Chinese 29% → 38%, overall 18% → 24%) |
 | 2026-10-12 | minor | Open-issue count (134 to 216), crash list and localization share (12% to 18%) updated to match docs/gaps.md |
 | 2026-10-12 | patch | Roto Brush span validation after trimming; command regressions for both layer edges |
diff --git a/docs/scripting-parity.md b/docs/scripting-parity.md
index 8d2934518..96e298ece 100644
--- a/docs/scripting-parity.md
+++ b/docs/scripting-parity.md
@@ -20,7 +20,7 @@ our own scripts; no real-world script library has been run against both apps.
 | Expression performance | Cached, multi-frame | Per-thread boa contexts | unknown | No benchmark |
 | Scripting object model | `app`, `Project`, items, layers, properties, keys, eases, render queue, `TextDocument`, `Shape`, markers, `File`/`Folder`, `Socket`, `app.settings` | Same classes, edits run through undoable engine commands; match names table; layers, groups and properties are callable (`layer("Effects")(1)` is `.property(...)`) | good | `crates/script` tests (≈ 10 test files) |
 | `$.evalFile`, `BridgeTalk` | Evaluate another script file; identify the host application and message other Adobe applications | `$.evalFile` evaluates a file relative to the calling file (nested at most 32 deep, under the scripts' file gate) and returns its last value; `BridgeTalk` names the host honestly (`appName` `effectcraft`, its version); messaging other applications throws "not supported" | partial | `tests_evalfile.rs` (#760); no inter-application messaging |
-| ScriptUI | Dialogs, palettes, dockable panels, resource strings, `onDraw` / ScriptUIGraphics, mouse events | Same, dockable panels reopen at launch | good | `ui_scriptui`, `tests_ui*` |
+| ScriptUI | Dialogs, palettes, dockable panels, resource strings, `onDraw` / ScriptUIGraphics, mouse events | Same, dockable panels reopen at launch; a docked panel gets its dock's size and `onResize` (`scriptui.resize`, #2585); a drag keeps reaching the control it started on past the window edge, and `MouseEvent.buttons` reports the held buttons (#2584) | good | `ui_scriptui`, `tests_ui*` |
 | `app.scheduleTask` / `cancelTask` | One-shot and repeating tasks (polling, panel refresh) until `cancelTask` | Same: repeating tasks run every `delay` ms (at least 50 ms, at most 64 pending per script) until `cancelTask`, until they throw (reported once, then cancelled), or until their owner goes: a script's last window closing, or the project closing for scripts without windows (a Startup script's tasks go on until EffectCraft quits); frontends tick them every frame, agents with `script.runTasks` | good | `tests_tasks.rs` (#773); one-shot tasks of a script file still run right after it, not after their delay |
 | Scripts menu, ScriptUI Panels folder | yes | yes; a subfolder (one level) of either folder is a submenu named after it | same | [plugins.md](plugins.md) |
 | Startup / Shutdown folders | yes | `Scripts/Startup` runs at launch and `Scripts/Shutdown` runs as the desktop app quits, after the project is closed, each in alphabetical order | partial | `crates/script/src/tests/startup.rs`; each script has its own global scope, so a Startup script's variables and functions are not available to later scripts ([plugins.md](plugins.md)) |

From 1158022585666a11d046351cc5ca448509d83c72 Mon Sep 17 00:00:00 2001
From: bflatastic <bombayapirat@gmail.com>
Date: Fri, 30 Oct 2026 07:53:12 +0700
Subject: [PATCH 7/8] Settings: a dragged UI Scale applies on release (#2582)

Dragging an integer setting applied every step, so UI Scale resized the
interface under the pointer mid-drag. A dragged value now shows in its
field and applies when the button is released (a typed one already
waited for Enter).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 crates/ui-egui/src/panels/settings.rs | 13 ++++++++----
 crates/ui-egui/tests/it/ui_panels.rs  | 30 +++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/crates/ui-egui/src/panels/settings.rs b/crates/ui-egui/src/panels/settings.rs
index f4dd89bfc..562a90132 100644
--- a/crates/ui-egui/src/panels/settings.rs
+++ b/crates/ui-egui/src/panels/settings.rs
@@ -117,15 +117,20 @@ fn page_ui(app: &mut EffectcraftApp, ui: &mut egui::Ui, page: &Page, cur: &Value
                             ui.add_sized(vec2(label_w, 18.0), egui::Label::new(format!("{}:", tr(label))).truncate());
                             let r = match kind {
                                 Kind::Int(lo, hi, unit) => {
-                                    let mut x = v.as_i64().unwrap_or(0);
-                                    // A typed number applies once entered: typing 85 into UI Scale
-                                    // doesn't resize the interface to 75 % at its first digit.
+                                    // A dragged value applies on release, and a typed one once
+                                    // entered: UI Scale doesn't resize the interface under the
+                                    // pointer mid-drag (#2582) or at a typed number's first digit.
+                                    let held = egui::Id::unique(("settings-drag", key));
+                                    let mut x = ui.data(|d| d.get_temp::<i64>(held)).unwrap_or_else(|| v.as_i64().unwrap_or(0));
                                     let drag = egui::DragValue::new(&mut x).range(lo..=hi).speed(0.25).update_while_editing(false);
                                     let r = ui.add(crate::widgets::drag_value(drag));
                                     if !unit.is_empty() {
                                         ui.label(RichText::new(tr(unit)).color(t.text_dim));
                                     }
-                                    if r.changed() {
+                                    if r.dragged() {
+                                        ui.data_mut(|d| d.insert_temp(held, x));
+                                    } else if r.changed() || r.drag_stopped() {
+                                        ui.data_mut(|d| d.remove::<i64>(held));
                                         acts.push(Act::Set(key.into(), json!(x)));
                                     }
                                     r
diff --git a/crates/ui-egui/tests/it/ui_panels.rs b/crates/ui-egui/tests/it/ui_panels.rs
index db9ef7373..6d06c6bf7 100644
--- a/crates/ui-egui/tests/it/ui_panels.rs
+++ b/crates/ui-egui/tests/it/ui_panels.rs
@@ -664,3 +664,33 @@ fn transition_presets_apply_from_effects_and_presets() {
     assert_eq!(fx.name, "Radial Wipe");
     assert_eq!(fx.prop("completion").unwrap().keys.len(), 2);
 }
+
+/// #2582: dragging Settings' UI Scale doesn't resize the interface under the pointer; the value
+/// applies once the button is released.
+#[test]
+fn ui_scale_applies_when_the_drag_ends() {
+    let mut h = harness();
+    open_settings(&mut h);
+    let e = h.state().auto.find("settings.appearance.uiScale").expect("the UI Scale field");
+    let from = pos2(e.rect[0] + e.rect[2] / 2.0, e.rect[1] + e.rect[3] / 2.0);
+    h.input_mut().events.push(Event::PointerMoved(from));
+    h.input_mut().events.push(Event::PointerButton { pos: from, button: egui::PointerButton::Primary, pressed: true, modifiers: Default::default() });
+    h.step();
+    for k in 1..=8 {
+        h.input_mut().events.push(Event::PointerMoved(from + egui::vec2(10.0 * k as f32, 0.0)));
+        h.step();
+        assert_eq!(scale(&h), (100, 1.0), "nothing applies mid-drag");
+    }
+    h.input_mut().events.push(Event::PointerButton {
+        pos: from + egui::vec2(80.0, 0.0),
+        button: egui::PointerButton::Primary,
+        pressed: false,
+        modifiers: Default::default(),
+    });
+    h.run_steps(4);
+    let (pct, zoom) = scale(&h);
+    assert!(pct > 100 && (zoom - pct as f32 / 100.0).abs() < 1e-6, "applied on release: {pct} {zoom}");
+    click(&mut h, "settings.cancel");
+    h.run_steps(2);
+    assert_eq!(scale(&h), (100, 1.0));
+}

From f6222ff5d5c53dc2847c47e61774b10ce4567533 Mon Sep 17 00:00:00 2001
From: erythrofr <20369086+erythrofr@users.noreply.github.com>
Date: Fri, 30 Oct 2026 02:47:31 +0100
Subject: [PATCH 8/8] Tests: document crop/resize regressions

Describe the dimension, pixel-preservation and extreme-input scenarios and
their synthetic-frame helper to address the review's documentation warning.
Test logic and the crop/resize implementation are unchanged.

AI assistance: OpenAI Codex (GPT-6).
---
 crates/export/src/pipeline.rs             | 4 ++++
 crates/export/tests/it/render_settings.rs | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/crates/export/src/pipeline.rs b/crates/export/src/pipeline.rs
index 7b9e4111c..8e8c90561 100644
--- a/crates/export/src/pipeline.rs
+++ b/crates/export/src/pipeline.rs
@@ -1063,6 +1063,7 @@ mod tests {
         }
     }
 
+    /// Regress the locked-aspect example: cropping 1920x1080 must resize to 1280x1440.
     #[test]
     fn crop_resize_applies_margins_once() {
         use effectcraft_project::render_queue::{Crop, OutputModule, Resize};
@@ -1077,6 +1078,7 @@ mod tests {
         assert_eq!(img.data.len(), 1280 * 1440);
     }
 
+    /// Apply output-module geometry to a synthetic frame without rendering or writing files.
     fn run_crop_resize(img: Image, output: &effectcraft_project::render_queue::OutputModule, scale: f64) -> Image {
         use effectcraft_project::render_queue::RenderSettings;
         let project = Project::default();
@@ -1097,6 +1099,7 @@ mod tests {
         Cx::new(&job).crop_resize(img)
     }
 
+    /// Match predicted dimensions across crop, padding, ROI scale, aspect locks and resize qualities.
     #[test]
     fn crop_resize_dimensions_match_the_output_module() {
         use effectcraft_project::render_queue::{Crop, OutputModule, Resize};
@@ -1124,6 +1127,7 @@ mod tests {
         }
     }
 
+    /// Exercise zero/empty inputs, collapsed crops and existing caps on extreme single-axis resizes.
     #[test]
     fn crop_resize_zero_and_extreme_sizes_stay_bounded() {
         use effectcraft_project::render_queue::{Crop, OutputModule, Resize};
diff --git a/crates/export/tests/it/render_settings.rs b/crates/export/tests/it/render_settings.rs
index c2d7dcbfa..0fd6d471b 100644
--- a/crates/export/tests/it/render_settings.rs
+++ b/crates/export/tests/it/render_settings.rs
@@ -174,6 +174,8 @@ fn crop_roi_and_resize() {
     assert_eq!((z.width(), z.height()), (32, 24));
 }
 
+/// Resizing to the cropped frame's own dimensions must preserve every decoded PNG pixel.
+/// Compare against crop-only output for padding and scaled ROIs with both resize qualities.
 #[test]
 fn crop_resize_preserves_pixels_when_the_cropped_size_is_requested() {
     let (p, cid) = project(FrameRate::new(25, 1), |_, _| {});