CI: packaging lint passes again (wasm-bindgen install step as an if, not A && B || C)

actionlint's shellcheck flagged SC2015 on release.yml's Install wasm-bindgen CLI step, failing
the Packaging lint workflow on main and release since 2 October.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -221,8 +221,9 @@ jobs:
       - name: Install wasm-bindgen CLI
         run: |
           # Must match the wasm-bindgen version in Cargo.lock exactly (cargo xtask web checks it).
-          command -v wasm-bindgen >/dev/null && wasm-bindgen --version | grep -q "$WASM_BINDGEN_VERSION" \
-            || cargo install wasm-bindgen-cli --version "$WASM_BINDGEN_VERSION" --locked
+          if ! { command -v wasm-bindgen >/dev/null && wasm-bindgen --version | grep -q "$WASM_BINDGEN_VERSION"; }; then
+            cargo install wasm-bindgen-cli --version "$WASM_BINDGEN_VERSION" --locked
+          fi
           wasm-bindgen --version
       - name: Apply version override
         if: inputs.version != ''

AGENTS.md

@@ -3,6 +3,39 @@
 These rules apply to every human and AI contributor. `CLAUDE.md` holds the working instructions; this
 file holds the rules that must never be broken. When the two disagree, this file wins.
 
+## Never crash
+
+People trust EffectCraft with hours of work. A malformed project, PSD, SVG, Lottie or media file, a bad
+expression or script, a broken plug-in, a bad control-channel or MCP argument, a corrupt preferences file
+or a full disk must produce an error the user (or agent) can act on, never a crash and never lost work.
+**This rule outranks feature work:** don't ship a feature by adding a panic path, and fix a crash before
+building on top of it. Full standard: [craftrules `standards/never-crash.md`](https://github.com/storytold/craftrules/blob/main/standards/never-crash.md).
+
+- **Fail with `Result<T, E>`** through the crate's error type and propagate with `?`; add context
+  (`map_err`, an error variant) rather than discarding it. Lenient readers fall back and record the repair.
+- **No panicking shortcuts in non-test code:** no `unwrap()`, `expect()`, `panic!`, `unreachable!`,
+  `todo!` or `unimplemented!`. Use `?`, `ok_or(..)?`, `let … else`, `if let`, or `unwrap_or*` where a
+  fallback is genuinely correct (never where it would silently corrupt a document). Unfinished features
+  return an "unsupported" error. The only exception is a provably infallible literal, written as
+  `#[allow(clippy::expect_used)]` + `.expect("why this cannot fail")`.
+- **No `unsafe`** (`unsafe_code = "forbid"` for the workspace).
+- **Every input-derived number is hostile.** Use `get()` instead of `[i]`/`[a..b]` when the position
+  comes from a file, a user, an agent or arithmetic on those; slice strings only at char boundaries; use
+  checked or saturating arithmetic for lengths, offsets and counts; guard division by zero and NaN/inf
+  casts; cap allocations sized by input.
+- **Bound recursion:** projects, precomps, expressions and SVG/PSD trees can be cyclic or deeply nested;
+  walk them with seen-sets or depth limits.
+- **Don't cascade:** handle lock poisoning (`lock().unwrap_or_else(PoisonError::into_inner)` or an
+  error), and treat worker-thread join results as `Result`s.
+- **Last-resort guard:** the app wraps command execution and file import/export in a panic hook /
+  `catch_unwind` boundary that turns an escaped panic into an error and keeps the document. It is a
+  safety net, not a substitute for the rules above; keep `panic = "unwind"`.
+- **Prove it:** every crash fix comes with a small synthetic regression test that panicked before the fix.
+
+Tests, benches, fuzz targets and `xtask` may `unwrap()`; `clippy.toml` allows it in tests. Crates that are
+clean carry `#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented,
+clippy::todo, clippy::unreachable)]`; new crates start with it.
+
 ## 1. Assets: no Adobe artwork, every asset licensed and attributed
 
 This rule is absolute. Breaking it is the most serious mistake a contributor can make on this project.

CLAUDE.md

@@ -10,6 +10,7 @@ EffectCraft is a clean-room, open-source, pure-Rust motion graphics and visual e
 
 ## Non-negotiables
 **Read [`AGENTS.md`](AGENTS.md) first; its rules override everything here.** No Adobe assets, every asset licensed + attributed (`cargo xtask assets`).
+- **Never crash** (AGENTS.md "Never crash"; outranks feature work: a crash loses people's work). Non-test code has no `unwrap()`/`expect()`/`panic!`/`unreachable!`/`todo!`/`unimplemented!` and no `unsafe`: return `Result` and use `?`, `ok_or`, `let … else`. Input-derived indices, slices and arithmetic use `get()` and checked/saturating math; recursion is depth-limited; locks handle poisoning. The app's last-resort guard turns an escaped panic into an error and keeps the document. Every crash fix gets a regression test. Standard: [craftrules `standards/never-crash.md`](https://github.com/storytold/craftrules/blob/main/standards/never-crash.md).
 - **Clean-room.** Behaviour and public docs only. No GPL/LGPL/AGPL code. ffmpeg only as an external test oracle.
 - **Pure Rust.** Media codecs come from FilmCraft crates (git deps behind `crates/media`, see `plan/adr/0001`).
 - **Layering** (`cargo xtask layers`): nothing below L5 depends on egui/eframe/winit/rfd/cpal; L0–L4 build for wasm32.

CONTRIBUTING.md

@@ -24,6 +24,10 @@ cargo xtask ci                           # what every commit must pass
 - **Everything is a command.** New features are engine commands with an id, label, menu path,
   shortcut and parameters, so the UI, the CLI and the MCP server get them at once. Interactive
   widgets register an automation id.
+- **Never crash.** Non-test code returns errors instead of panicking: no `unwrap()`, `expect()`,
+  `panic!`, `unreachable!`, `todo!`, `unimplemented!` or `unsafe`, checked indexing and arithmetic on
+  input-derived values, and a regression test with every crash fix. See the "Never crash" section of
+  [AGENTS.md](AGENTS.md).
 - **Tests with every change**, and green `cargo xtask ci` before every commit. One task per commit.
 
 ## How to add…

Cargo.lock

@@ -1134,7 +1134,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "cpal",
  "effectcraft-engine",
@@ -1155,7 +1155,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-automation"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-engine",
  "effectcraft-host",
@@ -1167,14 +1167,14 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-av1enc"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "filmcraft-av1",
 ]
 
 [[package]]
 name = "effectcraft-cli"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "cpu-time",
  "effectcraft-automation",
@@ -1190,7 +1190,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-color"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "proptest",
  "serde",
@@ -1198,7 +1198,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-effects"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-geom",
@@ -1214,7 +1214,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-engine"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-effects",
@@ -1246,7 +1246,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-export"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-av1enc",
  "effectcraft-color",
@@ -1275,7 +1275,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-expr"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "boa_engine",
  "effectcraft-color",
@@ -1292,7 +1292,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-geom"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "proptest",
  "serde",
@@ -1300,7 +1300,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-gpu"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "bytemuck",
  "effectcraft-color",
@@ -1319,14 +1319,14 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-hevcenc"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "filmcraft-hevc",
 ]
 
 [[package]]
 name = "effectcraft-host"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-engine",
  "effectcraft-export",
@@ -1348,7 +1348,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-interchange"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-keyframe",
@@ -1367,7 +1367,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-keyframe"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-geom",
@@ -1379,7 +1379,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-lottie"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-effects",
@@ -1396,7 +1396,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-media"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-model",
  "effectcraft-pdf",
@@ -1421,7 +1421,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-model"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-geom",
  "image",
@@ -1432,14 +1432,14 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-opusenc"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "filmcraft-opus",
 ]
 
 [[package]]
 name = "effectcraft-path"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-geom",
  "effectcraft-keyframe",
@@ -1451,7 +1451,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-pdf"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-raster",
  "effectcraft-svg",
@@ -1465,7 +1465,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-plugin"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-effects",
  "effectcraft-keyframe",
@@ -1477,7 +1477,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-project"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-geom",
@@ -1490,14 +1490,14 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-psd"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "miniz_oxide 0.8.9",
 ]
 
 [[package]]
 name = "effectcraft-raster"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-geom",
@@ -1506,7 +1506,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-render"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-effects",
@@ -1528,7 +1528,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-script"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "boa_engine",
  "effectcraft-engine",
@@ -1543,7 +1543,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-svg"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-geom",
  "effectcraft-path",
@@ -1555,7 +1555,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-text"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-keyframe",
  "harfrust",
@@ -1567,7 +1567,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-time"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "proptest",
  "serde",
@@ -1575,7 +1575,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-track"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-raster",
  "rayon",
@@ -1586,7 +1586,7 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-ui-egui"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-color",
  "effectcraft-engine",
@@ -1614,11 +1614,11 @@ dependencies = [
 
 [[package]]
 name = "effectcraft-vp9enc"
-version = "0.1.1"
+version = "0.2.0"
 
 [[package]]
 name = "effectcraft-web"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "effectcraft-engine",
  "effectcraft-export",
@@ -6318,7 +6318,7 @@ checksum = "e450f9b2ed1dff33c94c12589a87338689467b9c4f5d8a5710bd09a847d2c8a7"
 
 [[package]]
 name = "xtask"
-version = "0.1.1"
+version = "0.2.0"
 dependencies = [
  "serde_json",
 ]

Cargo.toml

@@ -4,7 +4,7 @@ members = ["crates/*", "apps/*", "xtask"]
 default-members = ["crates/*", "apps/*"]
 
 [workspace.package]
-version = "0.1.1"
+version = "0.2.0"
 edition = "2024"
 license = "MIT OR Apache-2.0"
 rust-version = "1.95"
@@ -116,7 +116,7 @@ cpal = "0.16"
 # filmcraft-isobmff = { path = "../filmcraft/crates/isobmff" }
 
 [workspace.lints.rust]
-unsafe_code = "deny"
+unsafe_code = "forbid"
 
 [workspace.lints.clippy]
 dbg_macro = "warn"

ROADMAP.md

@@ -9,8 +9,8 @@ once.
 | M0 | Skeleton: crates, compositor, the After Effects style shell, control channel, `cargo xtask` | Done (web build: [docs/web.md](docs/web.md)) |
 | M1 | Keyframes: temporal and spatial interpolation, Easy Ease, roving, velocity | Done |
 | M2 | Compositing: 38 blend modes, track mattes, parenting, adjustment layers | Done |
-| M3 | Project operations: settings dialogs, layer commands, `.ecproj`, undo, After Effects menu bar | Mostly done |
-| M4 | Preview: precomps, motion blur, cached playback | Mostly done |
+| M3 | Project operations: settings dialogs, layer commands, `.ecproj`, undo, After Effects menu bar | Done (unsaved-changes prompts, Solid / Layer Settings, lock-aware layer commands, safe project files; View ▸ New Viewer still opens only the one locked viewer) |
+| M4 | Preview: precomps, motion blur, cached playback | Mostly done (Preserve frame rate / resolution when nested, one motion blur gate, RAM preview fixes, Cache Frames When Idle, motion blur of collapsed precomps and of animated shape / text content; left: content-keyed RAM preview frames) |
 | M5 | Timeline depth: graph editor, keyframe clipboard and dialogs, time remapping, pick-whips, expression editor | Done |
 | M6 | Shapes, masks and footage: shape operators, masks and the pen tool, video and image import | Done |
 | M7 | 3D: 3D layers, cameras, lights, shadows, depth of field, 3D views and camera tools | In review |
@@ -33,6 +33,6 @@ Measured feature by feature in [docs/parity.md](docs/parity.md) (4 October 2026)
 - **≈ 8.5 agent-hours of work remain**: about **2–3 hours of wall-clock time** with five Claude
   Opus 5.5 agents in parallel, ≈ 1 hour without learned models for Roto Brush and face tracking.
 - What is left: GPU kernels for the remaining visual effects, and learned-model quality for Roto
-  Brush and face tracking.
+  Brush and face tracking; in previews, content-keyed RAM preview frames ([parity.md](docs/parity.md#highest-value-gaps-in-order)).
 
 Come tell us what matters most to you on [Discord](https://discord.gg/artcraft).

apps/effectcraft-cli/src/main.rs

@@ -34,6 +34,8 @@
 //! `<comp>` is a comp id or name (`-` = the active comp); `<layer>` an id, `#n` or name; `<value>`
 //! is JSON (`50`, `[960,540]`, `"#ff0000"`) or a bare string. See `docs/agents.md`.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 use effectcraft_automation::tools::{self, Reply};
 use effectcraft_automation::{Backend, McpServer};
 use serde_json::{Value, json};

apps/effectcraft-web/src/lib.rs

@@ -20,6 +20,8 @@
 //!
 //! [`store`] is portable (unit-tested natively); everything else is `wasm32`-only.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 pub mod store;
 
 #[cfg(target_arch = "wasm32")]

apps/effectcraft-web/src/persist.rs

@@ -167,7 +167,7 @@ pub fn restore(s: &mut Session) -> bool {
     }
     if meta.dirty {
         // Unsaved changes stay unsaved.
-        s.bump();
+        s.mark_unsaved();
     }
     SNAP.with(|c| c.set((s.revision, 0.0)));
     log::info!("restored the last session ({})", meta.path.as_deref().unwrap_or("untitled"));

apps/effectcraft/src/main.rs

@@ -5,6 +5,8 @@
 //! `--control <port>` (or `EFFECTCRAFT_CONTROL_PORT`) starts a localhost JSON-lines control server;
 //! see `effectcraft_ui_egui::control` for the methods.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 mod audio_out;
 mod control_server;
 #[cfg(target_os = "macos")]
@@ -26,6 +28,7 @@ fn app_icon() -> egui::IconData {
 fn main() -> eframe::Result {
     // Help ▸ Enable Logging writes through this logger; warnings feed the compatibility report.
     effectcraft_engine::logging::install();
+    effectcraft_engine::logging::install_panic_hook();
     let mut control_port: Option<u16> = std::env::var("EFFECTCRAFT_CONTROL_PORT").ok().and_then(|p| p.parse().ok());
     let mut files = Vec::new();
     let mut demo = true;

clippy.toml

@@ -0,0 +1,4 @@
+allow-unwrap-in-tests = true
+allow-expect-in-tests = true
+allow-panic-in-tests = true
+allow-indexing-slicing-in-tests = true

crates/automation/src/lib.rs

@@ -13,6 +13,8 @@
 //! Layering: depends on `effectcraft-engine` only (never egui); the CLI injects a fully wired
 //! session (`effectcraft_host::session()`).
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 pub mod backend;
 pub mod base64;
 pub mod bridge;

crates/av1enc/src/decide.rs

@@ -378,7 +378,13 @@ impl<'a> Decider<'a> {
                 }
             }
         }
-        let (_, y_mode, tx_type_y, ty, recon) = best.expect("an intra mode");
+        // 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 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]));
         let tx_type_y = if ty.nonzero { tx_type_y } else { DCT_DCT };
         self.mark_decoded(0, r, c, n4);
@@ -414,16 +420,17 @@ impl<'a> Decider<'a> {
         let uv_mode = best_uv.1;
         let uv_tx = tx_size_for(clog2);
         let uv_type = intra_uv_tx_type(uv_mode, uv_tx);
-        let mut tuv = Vec::with_capacity(2);
-        for i in 0..2 {
+        let mut code_uv = |i: usize| {
             predict_intra(&ced[i], &ce[i], uv_mode, &mut pred);
-            tuv.push(self.code_tx(1 + i, c * 2, r * 2, clog2, uv_type, &pred[..cn * cn], true));
+            let t = self.code_tx(1 + i, c * 2, r * 2, clog2, uv_type, &pred[..cn * cn], true);
             self.mark_decoded(1 + i, r, c, n4);
-        }
-        let skip = !ty.nonzero && !tuv[0].nonzero && !tuv[1].nonzero;
-        let dist = ty.dist + tuv[0].dist + tuv[1].dist;
-        let bits = if skip { 1.0 } else { ty.bits + tuv[0].bits + tuv[1].bits + 1.0 } + MODE_BITS_INTRA + 2.0;
-        let [u, v]: [TxResult; 2] = tuv.try_into().ok().expect("two chroma planes");
+            t
+        };
+        let u = code_uv(0);
+        let v = code_uv(1);
+        let skip = !ty.nonzero && !u.nonzero && !v.nonzero;
+        let dist = ty.dist + u.dist + v.dist;
+        let bits = if skip { 1.0 } else { ty.bits + u.bits + v.bits + 1.0 } + MODE_BITS_INTRA + 2.0;
         let leaf = Leaf { bsize, is_inter: false, y_mode, uv_mode, tx_type_y, mv: [0, 0], skip, coefs: [ty.levels, u.levels, v.levels] };
         (leaf, dist + self.lambda * bits)
     }
@@ -432,8 +439,9 @@ impl<'a> Decider<'a> {
         let n4 = NUM_4X4_BLOCKS_WIDE[bsize] as usize;
         let n = n4 * 4;
         let log2 = n.trailing_zeros();
+        // Inter blocks are only decided with a reference frame; without one, code intra.
+        let Some(refr) = self.refr else { return self.intra_leaf(r, c, bsize) };
         let (mv, mv_bits) = self.motion_search(r, c, n, parent_mv);
-        let refr = self.refr.expect("reference frame");
         let mut pred = vec![0u16; n * n];
         let mut tx = Vec::with_capacity(3);
         let mut dist = 0.0;
@@ -461,7 +469,16 @@ impl<'a> Decider<'a> {
         }
         let skip = tx.iter().all(|t| !t.nonzero);
         let bits = mode_bits + if skip { 1.0 } else { 1.0 + tx.iter().map(|t| t.bits).sum::<f64>() };
-        let [y, u, v]: [TxResult; 3] = tx.try_into().ok().expect("three planes");
+        let [y, u, v]: [TxResult; 3] = match tx.try_into() {
+            Ok(planes) => planes,
+            // One transform block per plane was coded above.
+            Err(_) => {
+                return (
+                    Leaf { bsize, is_inter: true, y_mode: NEWMV, uv_mode: DC_PRED, tx_type_y: DCT_DCT, mv, skip: true, coefs: Default::default() },
+                    f64::INFINITY,
+                );
+            }
+        };
         let leaf = Leaf { bsize, is_inter: true, y_mode: NEWMV, uv_mode: DC_PRED, tx_type_y: DCT_DCT, mv, skip, coefs: [y.levels, u.levels, v.levels] };
         (leaf, dist + self.lambda * bits)
     }
@@ -470,7 +487,7 @@ impl<'a> Decider<'a> {
     /// Returns the vector and an estimate of its coding cost in bits.
     fn motion_search(&self, r: usize, c: usize, n: usize, parent_mv: Option<[i32; 2]>) -> ([i32; 2], f64) {
         let g = self.g;
-        let refr = self.refr.expect("reference frame");
+        let Some(refr) = self.refr else { return ([0, 0], 0.0) };
         let mi = |rr: usize, cc: usize| self.mvs[rr * g.mi_cols + cc];
         let mut pred_mv = [0, 0];
         let mut cands: Vec<[i32; 2]> = vec![[0, 0]];
@@ -579,7 +596,7 @@ impl<'a> Decider<'a> {
     /// Approximate luma prediction for motion search: exact at whole and half-sample
     /// positions (precomputed planes), averaged neighbours at quarter-sample positions.
     fn search_block(&self, mv: [i32; 2], x: usize, y: usize, n: usize, out: &mut [u16]) {
-        let refr = self.refr.expect("reference frame");
+        let Some(refr) = self.refr else { return };
         let (w, h) = (self.g.width as i32, self.g.height as i32);
         // per axis: up to two (integer offset, half) taps
         let axis = |v: i32| -> ([(i32, bool); 2], usize) {

crates/av1enc/src/lib.rs

@@ -8,6 +8,8 @@
 //!
 //! The public API below is the contract `crates/export` codes against; keep it stable.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 mod bitw;
 mod cdf;
 mod decide;
@@ -444,7 +446,16 @@ impl Encoder {
         let src = self.load_source(frame);
         let (frame_obu, rf) = match self.cfg.rate {
             RateControl::ConstantQ(q) => self.encode_frame(&src, key, q.max(1)),
-            RateControl::Bitrate { .. } => self.encode_rate_controlled(&src, key),
+            RateControl::Bitrate { .. } => match self.rc.take() {
+                Some(mut rc) => {
+                    let out = self.encode_rate_controlled(&src, key, &mut rc);
+                    self.rc = Some(rc);
+                    out
+                }
+                // The state is created with the encoder for bitrate mode; without it, encode at a
+                // middle quantizer rather than fail.
+                None => self.encode_frame(&src, key, 128),
+            },
         };
         self.refr = Some(rf);
         self.frame_num += 1;
@@ -456,9 +467,8 @@ impl Encoder {
         Packet { data, keyframe: key }
     }
 
-    fn encode_rate_controlled(&mut self, src: &[Plane; 3], key: bool) -> (Vec<u8>, RefFrame) {
+    fn encode_rate_controlled(&mut self, src: &[Plane; 3], key: bool, rc: &mut RateState) -> (Vec<u8>, RefFrame) {
         let first = self.frame_num == 0;
-        let rc = self.rc.as_ref().expect("rate control state");
         let (frame_bits, debt, q_inter) = (rc.frame_bits, rc.debt, rc.q);
         // key frames get a lower quantizer and a larger share of the budget
         let key_boost = 1.0 + (self.cfg.keyint.clamp(1, 60) as f64 - 1.0).sqrt() * 0.75;
@@ -481,8 +491,8 @@ impl Encoder {
                 q = (q + 30.0 * err).clamp(1.0, 255.0);
             }
         }
-        let (obu, rf, bits) = best.expect("encoded");
-        let rc = self.rc.as_mut().expect("rate control state");
+        // At least one pass ran, so `best` is set.
+        let Some((obu, rf, bits)) = best else { return self.encode_frame(src, key, q.round().clamp(1.0, 255.0) as u8) };
         rc.debt += bits - budget;
         // adapt the inter quantizer: about 30 index steps per doubling of the rate
         let err = (bits / target).log2().clamp(-1.0, 1.0);

crates/av1enc/src/transform.rs

@@ -290,7 +290,11 @@ pub(crate) fn kinds(tx_type: usize) -> (Kind, Kind) {
         ADST_DCT => (Kind::Adst, Kind::Dct),
         DCT_ADST => (Kind::Dct, Kind::Adst),
         ADST_ADST => (Kind::Adst, Kind::Adst),
-        _ => unreachable!("unsupported transform type {tx_type}"),
+        // The encoder only chooses the four types above.
+        _ => {
+            debug_assert!(false, "unsupported transform type {tx_type}");
+            (Kind::Dct, Kind::Dct)
+        }
     }
 }
 

crates/av1enc/src/writer.rs

@@ -211,7 +211,8 @@ impl<'a> TileWriter<'a> {
                 debug_assert_eq!(leaf.bsize, bsize);
                 self.block(r, c, leaf);
             }
-            Node::Out => unreachable!("decided block inside the frame"),
+            // Blocks inside the frame are always decided; nothing is coded outside it.
+            Node::Out => debug_assert!(false, "undecided block inside the frame"),
         }
     }
 
@@ -460,10 +461,11 @@ impl<'a> TileWriter<'a> {
                 if set > 0 && self.qidx > 0 {
                     let sqr = TX_SIZE_SQR[tx_sz] as usize;
                     if b.is_inter {
-                        let s = TX_TYPE_INTER_INV_SET3.iter().position(|&v| v as usize == t).expect("inter tx type in set");
+                        // 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).expect("intra tx type in set");
+                        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 {

crates/color/src/lib.rs

@@ -5,6 +5,8 @@
 //! standard definitions of the "classic" photographic modes; they are applied to un-premultiplied
 //! colour and composited with Porter-Duff source-over on premultiplied pixels.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 pub mod blend;
 pub mod icc;
 pub mod space;

crates/effects/src/keylight.rs

@@ -610,6 +610,9 @@ mod tests {
         let g = run_fx("ec.keying.keylight", &[("screenColour", green()), ("screenGain", num(150.0))], plate(), 0.0, EffectEnv::default());
         assert!(g.img.get(27, 5)[3] < out.img.get(27, 5)[3]);
         assert_eq!(crate::lookup("Keylight (1.2)").map(|s| s.id), Some("ec.keying.keylight"));
+        // Searches find it by After Effects' name as well as its own.
+        let spec = crate::find("ec.keying.keylight").unwrap();
+        assert!(crate::name_matches(spec, "keylight") && crate::name_matches(spec, "key light") && !crate::name_matches(spec, "blur"));
     }
 
     /// Instances saved with the flat layout get their parameters moved into the twirl-downs.

crates/effects/src/lib.rs

@@ -6,6 +6,8 @@
 //! [`instantiate`]), so parameters animate, take expressions and are addressable like any other
 //! property.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 pub mod audio_fx;
 mod blur2;
 mod blur3;
@@ -502,14 +504,25 @@ pub fn categories() -> Vec<&'static str> {
     v
 }
 
+/// After Effects' third-party display names of effects we register under a generic name.
+const ALIASES: &[(&str, &[&str])] = &[("ec.keying.keylight", keylight::KEYLIGHT_ALIASES)];
+
+/// Other names effect `id` answers to (in [`lookup`] and searches).
+pub fn aliases(id: &str) -> &'static [&'static str] {
+    ALIASES.iter().find(|(i, _)| *i == id).map_or(&[], |(_, a)| a)
+}
+
+/// Search (Effects & Presets, `effect.list`): the display name or one of its [`aliases`]
+/// contains `query` (lowercase).
+pub fn name_matches(spec: &EffectSpec, query: &str) -> bool {
+    std::iter::once(spec.name).chain(aliases(spec.id).iter().copied()).any(|n| n.to_lowercase().contains(query))
+}
+
 /// Find by id or (case-insensitive) display name.
 pub fn lookup(name_or_id: &str) -> Option<&'static EffectSpec> {
     find(name_or_id)
         .or_else(|| all().into_iter().find(|s| s.name.eq_ignore_ascii_case(name_or_id)))
-        .or_else(|| {
-            // After Effects' third-party display names we register under a generic name.
-            keylight::KEYLIGHT_ALIASES.iter().any(|a| a.eq_ignore_ascii_case(name_or_id)).then(|| find("ec.keying.keylight")).flatten()
-        })
+        .or_else(|| ALIASES.iter().find(|(_, names)| names.iter().any(|a| a.eq_ignore_ascii_case(name_or_id))).and_then(|(id, _)| find(id)))
         .or_else(|| {
             // Display names of earlier versions.
             migrate::EFFECT_NAME_ALIASES.iter().find(|(old, _)| old.eq_ignore_ascii_case(name_or_id)).and_then(|(_, id)| find(id))
@@ -551,8 +564,8 @@ pub fn instantiate(spec: &EffectSpec, ids: &mut Ids, instance_name: &str, layer_
         if matches!(ps.ui, ParamUi::Checkbox | ParamUi::Popup { .. } | ParamUi::Layer) {
             pr.hold_only = true;
         }
-        match path {
-            Some(path) => nested_group(&mut g, ids, path).children.push(pr.into()),
+        match path.and_then(|path| nested_group(&mut g, ids, path)) {
+            Some(sub) => sub.children.push(pr.into()),
             None => g.children.push(pr.into()),
         }
         // Layer parameters carry a source choice (Source / Masks / Effects & Masks) unless the
@@ -563,8 +576,8 @@ pub fn instantiate(spec: &EffectSpec, ids: &mut Ids, instance_name: &str, layer_
         if matches!(ps.ui, ParamUi::Layer) && !spec.params.iter().any(|q| q.id == sid) {
             let mut src = Property::new(ids.alloc(), &layer_source_id(leaf), &format!("{} Source", ps.name), Value::Enum(2)).with_ui(ParamUi::Hidden);
             src.hold_only = true;
-            match path {
-                Some(path) => nested_group(&mut g, ids, path).children.push(src.into()),
+            match path.and_then(|path| nested_group(&mut g, ids, path)) {
+                Some(sub) => sub.children.push(src.into()),
                 None => g.children.push(src.into()),
             }
         }
@@ -765,7 +778,7 @@ fn group_name(m: &str) -> &str {
 }
 
 /// The nested group at `path` (`borders/autoScale`) under `g`, created on first use.
-fn nested_group<'a>(g: &'a mut PropGroup, ids: &mut Ids, path: &str) -> &'a mut PropGroup {
+fn nested_group<'a>(g: &'a mut PropGroup, ids: &mut Ids, path: &str) -> Option<&'a mut PropGroup> {
     let (first, rest) = match path.split_once('/') {
         Some((a, b)) => (a, Some(b)),
         None => (path, None),
@@ -773,10 +786,10 @@ fn nested_group<'a>(g: &'a mut PropGroup, ids: &mut Ids, path: &str) -> &'a mut
     if g.sub(first).is_none() {
         g.children.push(ids.group(first, group_name(first)).into());
     }
-    let sub = g.sub_mut(first).expect("just added");
+    let sub = g.sub_mut(first)?;
     match rest {
         Some(r) => nested_group(sub, ids, r),
-        None => sub,
+        None => Some(sub),
     }
 }
 

crates/effects/src/migrate.rs

@@ -192,7 +192,7 @@ fn prop_at<'a>(g: &'a mut PropGroup, id: &str) -> Option<&'a mut Property> {
     }
 }
 
-fn group_at<'a>(g: &'a mut PropGroup, ids: &mut Ids, path: &str) -> &'a mut PropGroup {
+fn group_at<'a>(g: &'a mut PropGroup, ids: &mut Ids, path: &str) -> Option<&'a mut PropGroup> {
     let (first, rest) = match path.split_once('/') {
         Some((a, b)) => (a, Some(b)),
         None => (path, None),
@@ -200,10 +200,10 @@ fn group_at<'a>(g: &'a mut PropGroup, ids: &mut Ids, path: &str) -> &'a mut Prop
     if g.sub(first).is_none() {
         g.children.push(ids.group(first, group_name(first)).into());
     }
-    let sub = g.sub_mut(first).expect("just added");
+    let sub = g.sub_mut(first)?;
     match rest {
         Some(r) => group_at(sub, ids, r),
-        None => sub,
+        None => Some(sub),
     }
 }
 
@@ -288,8 +288,8 @@ pub fn upgrade_instance(spec: &EffectSpec, g: &mut PropGroup, ids: &mut Ids, lay
                     pr
                 }
             };
-            match path {
-                Some(path) => group_at(g, ids, path).children.push(pr.into()),
+            match path.and_then(|path| group_at(g, ids, path)) {
+                Some(sub) => sub.children.push(pr.into()),
                 None => g.children.push(pr.into()),
             }
         }
@@ -310,8 +310,8 @@ pub fn upgrade_instance(spec: &EffectSpec, g: &mut PropGroup, ids: &mut Ids, lay
                 src.hold_only = true;
                 src
             });
-            match path {
-                Some(path) => group_at(g, ids, path).children.push(src.into()),
+            match path.and_then(|path| group_at(g, ids, path)) {
+                Some(sub) => sub.children.push(src.into()),
                 None => g.children.push(src.into()),
             }
         }
@@ -363,7 +363,7 @@ mod tests {
         let removed = spec.params.last().unwrap().id;
         g.children.retain(|c| c.match_id() != removed);
         let popup = spec.params.iter().find(|p| matches!(p.ui, ParamUi::Popup { .. })).expect("Gaussian Blur has a popup");
-        let ParamUi::Popup { options } = &popup.ui else { unreachable!() };
+        let ParamUi::Popup { options } = &popup.ui else { panic!("not a popup") };
         {
             let pr = g.get_mut(popup.id).unwrap();
             pr.name = "Old Name".into();

crates/effects/src/ocio.rs

@@ -128,10 +128,14 @@ const fn sp(name: &'static str, prims: [[f64; 2]; 3], white: [f64; 2], tf: Tf) -
 }
 
 /// The built-in configuration's colour spaces, in popup order.
+const ACES2065_1: Space = sp("ACES2065-1", AP0, ACES_WHITE, Tf::Linear);
+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] = &[
-    sp("ACES2065-1", AP0, ACES_WHITE, Tf::Linear),
-    sp("ACEScg", AP1, ACES_WHITE, Tf::Linear),
-    sp("ACEScct", AP1, ACES_WHITE, Tf::AcesCct),
+    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)),
@@ -147,6 +151,7 @@ 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))
 }
@@ -778,7 +783,7 @@ fn ocio_look(ctx: &EffectCtx, mut b: Buf) -> Buf {
     }
     let (src, dst) = (space_at(ctx.params.e("source")), space_at(ctx.params.e("destination")));
     let inv = ctx.params.e("direction") == 1;
-    let cct = space_by_name("ACEScct").expect("built-in");
+    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);
@@ -805,8 +810,8 @@ fn profile(ctx: &EffectCtx, i: u32) -> (Space, bool) {
         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 => *space_by_name("ACEScg").expect("built-in"),
-        ColorSpace::Aces2065 => *space_by_name("ACES2065-1").expect("built-in"),
+        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)),
     };
@@ -816,8 +821,8 @@ fn profile(ctx: &EffectCtx, i: u32) -> (Space, bool) {
         2 => (ws(ColorSpace::Rec709), false),
         3 => (ws(ColorSpace::Rec2020), false),
         4 => (ws(ColorSpace::DisplayP3), false),
-        5 => (*space_by_name("ACEScg").expect("built-in"), true),
-        _ => (*space_by_name("ACES2065-1").expect("built-in"), true),
+        5 => (ACES_CG, true),
+        _ => (ACES2065_1, true),
     }
 }
 
@@ -1089,7 +1094,7 @@ pub fn color_program(id: &str, ctx: &EffectCtx) -> Option<(Vec<ColorOp>, Straigh
             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 = space_by_name("ACEScct").expect("built-in");
+                let cct = &ACES_CCT;
                 let (a, z) = if inv { (dst, src) } else { (src, dst) };
                 if inv {
                     list.reverse();
@@ -1157,7 +1162,7 @@ fn curve3(xs: [f64; 3], ys: [f64; 3], v: f64) -> f64 {
     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 x > pts.last().expect("non-empty").0 + 1e-4 && x < 1.0 - 1e-4 {
+        if pts.last().is_some_and(|l| x > l.0 + 1e-4) && x < 1.0 - 1e-4 {
             pts.push((x, y));
         }
     }
@@ -1196,7 +1201,7 @@ pub fn color_stabilizer_maps(ctx: &EffectCtx, b: &Buf) -> Option<[Vec<(f64, f64)
                 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 x > v.last().expect("non-empty").0 + 1e-4 && x < 1.0 - 1e-4 {
+                    if v.last().is_some_and(|l| x > l.0 + 1e-4) && x < 1.0 - 1e-4 {
                         v.push((x, y));
                     }
                 }

crates/effects/src/textfx.rs

@@ -686,13 +686,10 @@ fn path_text_passes(ctx: &EffectCtx, b: &Buf) -> Vec<TextPass> {
             let js = if j_scale != 0.0 { (1.0 + rnd(i, 4) * j_scale).max(0.05) } else { 1.0 };
             let jb = if j_base != 0.0 { rnd(i, 1) * j_base } else { 0.0 };
             let left = ink_left(c, true);
-            let set = match polys_by_alpha.iter_mut().find(|(a, _)| (*a - alpha).abs() < 1e-4) {
-                Some((_, v)) => v,
-                None => {
-                    polys_by_alpha.push((alpha, Vec::new()));
-                    &mut polys_by_alpha.last_mut().expect("pushed").1
-                }
-            };
+            if !polys_by_alpha.iter().any(|(a, _)| (*a - alpha).abs() < 1e-4) {
+                polys_by_alpha.push((alpha, Vec::new()));
+            }
+            let Some((_, set)) = polys_by_alpha.iter_mut().find(|(a, _)| (*a - alpha).abs() < 1e-4) else { continue };
             for st in parse_glyph(c) {
                 set.push(
                     st.iter()

crates/engine/src/autosave.rs

@@ -245,16 +245,17 @@ pub fn end(store: &dyn ConfigStore) {
 }
 
 /// After Effects' Increment and Save name: `Intro.ecproj` → `Intro 2.ecproj`, `Intro 2.ecproj`
-/// → `Intro 3.ecproj` (skipping names that exist).
+/// → `Intro 3.ecproj` (skipping names that exist; the extension, `.ecprojx` too, is kept).
 pub fn increment_path(path: &str, exists: impl Fn(&str) -> bool) -> String {
     let p = Path::new(path);
     let stem = p.file_stem().map(|s| s.to_string_lossy().to_string()).unwrap_or_default();
+    let ext = p.extension().map(|e| e.to_string_lossy().to_string()).unwrap_or_else(|| EXT.to_string());
     let (base, mut n) = match stem.rsplit_once(' ') {
         Some((b, n)) if !n.is_empty() && n.chars().all(|c| c.is_ascii_digit()) => (b.to_string(), n.parse::<u32>().unwrap_or(1) + 1),
         _ => (stem.clone(), 2),
     };
     loop {
-        let cand = p.with_file_name(format!("{base} {n}.{EXT}")).to_string_lossy().to_string();
+        let cand = p.with_file_name(format!("{base} {n}.{ext}")).to_string_lossy().to_string();
         if !exists(&cand) {
             return cand;
         }

crates/engine/src/camera_track.rs

@@ -382,7 +382,7 @@ impl Session {
         if !job.is_finished() {
             return false;
         }
-        let mut job = self.camera_job.take().expect("job");
+        let Some(mut job) = self.camera_job.take() else { return false };
         if let Some(t) = job.thread.take() {
             let _ = t.join();
         }

crates/engine/src/commands/anim.rs

@@ -6,7 +6,7 @@ use effectcraft_project::{LayerId, Property, Uid};
 use effectcraft_time::Tick;
 use serde_json::{Value, json};
 
-use super::prop::{edit_keys, prop_ref};
+use super::prop::prop_ref;
 use super::{CommandSpec, bad, comp_id, f_p, has_comp, has_keys, layers_p, merge_p, str_p, time_p};
 use crate::{EngineError, KeyClip, KeyRef, Result, Session, cmd, query};
 
@@ -73,11 +73,19 @@ fn paste(s: &mut Session, p: &Value) -> Result<Value> {
         let path = str_p(p, "path")?;
         comp.layer(*targets.first()?)?.props.prop(path).map(|pr| pr.uid)
     });
+    // Keys copied from several layers, pasted onto as many layers: the first copied layer's keys
+    // go to the first target and so on (else every target gets every copied property).
+    let mut sources: Vec<LayerId> = clip.iter().map(|c| c.layer).collect();
+    sources.dedup();
+    let paired = sources.len() > 1 && sources.len() == targets.len();
     // (layer, prop uid, clip index)
     let mut plan: Vec<(LayerId, Uid, usize)> = vec![];
-    for lid in &targets {
+    for (ti, lid) in targets.iter().enumerate() {
         let Some(l) = comp.layer(*lid) else { continue };
         for (ci, c) in clip.iter().enumerate() {
+            if paired && sources.get(ti) != Some(&c.layer) {
+                continue;
+            }
             let Some(sample) = c.keys.first().map(|k| &k.value) else { continue };
             let target = if clip.len() == 1 {
                 explicit
@@ -131,7 +139,14 @@ fn select_all(s: &mut Session, p: &Value) -> Result<Value> {
     let (cid, mut layers) = layers_p(s, p)?;
     let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
     let mut sel = vec![];
-    if p.get("layers").is_none() && p.get("layer").is_none() && !s.state.selected_props.is_empty() {
+    if let Some(visible) = super::visible_p(p) {
+        // Ctrl+Alt+A in the Timeline: every key it shows (its revealed properties).
+        for (lid, uid) in visible {
+            if let Some(pr) = comp.layer(lid).and_then(|l| l.props.find(uid)) {
+                sel.extend(pr.keys.iter().map(|k| KeyRef { layer: lid, prop: uid, time: k.time }));
+            }
+        }
+    } else if p.get("layers").is_none() && p.get("layer").is_none() && !s.state.selected_props.is_empty() {
         for (lid, uid) in &s.state.selected_props {
             if let Some(pr) = comp.layer(*lid).and_then(|l| l.props.find(*uid)) {
                 sel.extend(pr.keys.iter().map(|k| KeyRef { layer: *lid, prop: *uid, time: k.time }));
@@ -145,6 +160,37 @@ fn select_all(s: &mut Session, p: &Value) -> Result<Value> {
             l.props.walk("", &mut |_, pr| sel.extend(pr.keys.iter().map(|k| KeyRef { layer: l.id, prop: pr.uid, time: k.time })));
         }
     }
+    // Keys of locked layers can't be selected.
+    sel.retain(|k| comp.layer(k.layer).is_some_and(|l| !l.switches.locked));
+    s.state.selected_keys = sel;
+    Ok(json!(s.state.selected_keys.len()))
+}
+
+/// The keyframe context menu's Select Equal / Previous / Following Keyframes: in every property
+/// with a selected key, its keys with the same value as a selected one / before the first
+/// selected one / after the last selected one (the selected keys stay selected).
+fn select_related(s: &mut Session, which: &str) -> Result<Value> {
+    let comp = s.active_comp().ok_or(EngineError::NoComp)?;
+    let mut sel = s.state.selected_keys.clone();
+    let mut props: Vec<(LayerId, Uid)> = sel.iter().map(|k| (k.layer, k.prop)).collect();
+    props.sort();
+    props.dedup();
+    for (lid, uid) in props {
+        let Some(pr) = comp.layer(lid).and_then(|l| l.props.find(uid)) else { continue };
+        let picked: Vec<&Keyframe> = pr.keys.iter().filter(|k| sel.iter().any(|r| r.layer == lid && r.prop == uid && r.time == k.time)).collect();
+        let (Some(first), Some(last)) = (picked.iter().map(|k| k.time).min(), picked.iter().map(|k| k.time).max()) else { continue };
+        for k in &pr.keys {
+            let hit = match which {
+                "equal" => picked.iter().any(|p| p.value == k.value),
+                "previous" => k.time < first,
+                _ => k.time > last,
+            };
+            let r = KeyRef { layer: lid, prop: uid, time: k.time };
+            if hit && !sel.contains(&r) {
+                sel.push(r);
+            }
+        }
+    }
     s.state.selected_keys = sel;
     Ok(json!(s.state.selected_keys.len()))
 }
@@ -153,11 +199,8 @@ fn select_all(s: &mut Session, p: &Value) -> Result<Value> {
 fn nudge(s: &mut Session, p: &Value) -> Result<Value> {
     let frames = p.get("frames").and_then(Value::as_i64).ok_or_else(|| bad("keys.nudge", "missing `frames`"))?;
     let comp = s.active_comp().ok_or(EngineError::NoComp)?;
-    let d = Tick(comp.frame_duration().0 * frames);
-    edit_keys(s, "Nudge Keyframes", merge_p(p), move |_, _, t| {
-        *t += d;
-        true
-    })
+    let d = Tick(comp.frame_duration().0.saturating_mul(frames));
+    super::prop::shift_keys(s, "Nudge Keyframes", merge_p(p), d)
 }
 
 /// Edit one key directly: move it in time and/or set its value (Graph Editor drags).
@@ -386,7 +429,15 @@ pub fn specs() -> Vec<CommandSpec> {
     vec![
         cmd!("keys.copy", "Copy Keyframes", [], None, "{}", has_keys, copy),
         cmd!("keys.paste", "Paste Keyframes", [], None, "{layers?, prop?|path?, time?}", has_key_clip, paste),
-        cmd!("keys.selectAll", "Select All Keyframes", [], Some("Cmd+Alt+A"), "{layers?}", keys_or_layers, select_all),
+        cmd!(
+            "keys.selectAll",
+            "Select All Keyframes",
+            [],
+            Some("Cmd+Alt+A"),
+            "{layers?, visible?: [{layer, prop}] (every key of these properties)}",
+            keys_or_layers,
+            select_all
+        ),
         cmd!("keys.nudge", "Nudge Keyframes", [], None, "{frames, merge?}", has_keys, nudge),
         cmd!("keys.nudgeForward", "Move Keyframes 1 Frame Later", [], Some("Alt+ArrowRight"), "{}", has_keys, |s, _| nudge(s, &json!({"frames": 1}))),
         cmd!("keys.nudgeBackward", "Move Keyframes 1 Frame Earlier", [], Some("Alt+ArrowLeft"), "{}", has_keys, |s, _| nudge(s, &json!({"frames": -1}))),
@@ -399,6 +450,9 @@ pub fn specs() -> Vec<CommandSpec> {
             &json!({"frames": -10})
         )),
         cmd!("keys.set", "Edit Keyframe", [], None, "{layer?, path|prop, time (layer s), newTime?, value?, merge?}", has_comp, set_key),
+        cmd!("keys.selectEqual", "Select Equal Keyframes", [], None, "{}", has_keys, |s, _| select_related(s, "equal")),
+        cmd!("keys.selectPrevious", "Select Previous Keyframes", [], None, "{}", has_keys, |s, _| select_related(s, "previous")),
+        cmd!("keys.selectFollowing", "Select Following Keyframes", [], None, "{}", has_keys, |s, _| select_related(s, "following")),
         cmd!(
             "keys.setEase",
             "Set Keyframe Ease",

crates/engine/src/commands/app_more.rs

@@ -128,7 +128,7 @@ fn clear_recent_presets(s: &mut Session, _: &Value) -> Result<Value> {
 
 fn save_copy_xml(s: &mut Session, p: &Value) -> Result<Value> {
     let path = str_p(p, "path").ok_or_else(|| bad("file.saveCopyAsXml", "missing `path` (.ecprojx)"))?;
-    let xml = crate::xml_project::to_xml(&s.project.to_json()).map_err(EngineError::Other)?;
+    let xml = crate::xml_project::to_xml(&s.project.to_file_json()?).map_err(EngineError::Other)?;
     s.services.write_file(path, xml.as_bytes()).map_err(|e| EngineError::Other(format!("cannot write {path}: {e}")))?;
     s.toast(format!("Saved an XML copy to {path}"));
     Ok(json!({"path": path, "bytes": xml.len()}))

crates/engine/src/commands/autotrace.rs

@@ -162,7 +162,7 @@ fn run(s: &mut Session, p: &Value) -> Result<Value> {
         let base = masks.children.len();
         for k in 0..n_masks {
             // Depth decides the mode: outlines add, holes subtract.
-            let first = frames.iter().find_map(|f| f.get(k)).expect("mask");
+            let Some(first) = frames.iter().find_map(|f| f.get(k)) else { continue };
             let mode = if first.depth % 2 == 0 { MaskMode::Add } else { MaskMode::Subtract };
             let mode = if k == 0 { MaskMode::Add } else { mode };
             let mut g = build::mask(
@@ -173,14 +173,16 @@ fn run(s: &mut Session, p: &Value) -> Result<Value> {
                 build::MASK_COLORS[(base + k) % build::MASK_COLORS.len()],
             );
             if frames.len() > 1 {
-                let path = g.get_mut("path").expect("path");
-                for (f, lt) in frames.iter().zip(&layer_times) {
-                    if let Some(tr) = f.get(k) {
-                        effectcraft_keyframe::set_key(&mut path.keys, Keyframe::new(*lt, KV::Path(tr.path.clone())));
+                if let Some(path) = g.get_mut("path") {
+                    for (f, lt) in frames.iter().zip(&layer_times) {
+                        if let Some(tr) = f.get(k) {
+                            effectcraft_keyframe::set_key(&mut path.keys, Keyframe::new(*lt, KV::Path(tr.path.clone())));
+                        }
                     }
                 }
-                let op = g.get_mut("opacity").expect("opacity");
-                if frames.iter().any(|f| f.get(k).is_none()) {
+                if let Some(op) = g.get_mut("opacity")
+                    && frames.iter().any(|f| f.get(k).is_none())
+                {
                     for (f, lt) in frames.iter().zip(&layer_times) {
                         let mut key = Keyframe::new(*lt, KV::Scalar(if f.get(k).is_some() { 100.0 } else { 0.0 }));
                         key.in_interp = Interp::Hold;

crates/engine/src/commands/comp.rs

@@ -12,6 +12,14 @@ pub(crate) fn rate_p(p: &Value) -> Option<FrameRate> {
     f_p(p, "frameRate").or(f_p(p, "fps")).map(FrameRate::from_f64)
 }
 
+/// A zero, negative or tiny rate would make a zero-length frame (and divide by zero later).
+fn check_rate(p: &Value, cmd: &str) -> Result<()> {
+    match f_p(p, "frameRate").or(f_p(p, "fps")) {
+        Some(f) if !(0.001..=1000.0).contains(&f) => Err(bad(cmd, "frameRate: fps from 0.001 to 1000")),
+        _ => Ok(()),
+    }
+}
+
 fn apply_settings(c: &mut Comp, p: &Value) {
     let (ow, oh) = (c.width, c.height);
     if let Some(w) = p.get("width").and_then(Value::as_u64) {
@@ -90,9 +98,16 @@ fn apply_settings(c: &mut Comp, p: &Value) {
     if let Some(n) = p.get("adaptiveSampleLimit").and_then(Value::as_u64) {
         c.motion_blur_adaptive_limit = (n as u32).clamp(16, 256);
     }
+    if let Some(b) = p.get("preserveFrameRate").and_then(Value::as_bool) {
+        c.preserve_frame_rate = b;
+    }
+    if let Some(b) = p.get("preserveResolution").and_then(Value::as_bool) {
+        c.preserve_resolution = b;
+    }
 }
 
 fn new_comp(s: &mut Session, p: &Value) -> Result<Value> {
+    check_rate(p, "comp.new")?;
     let name = str_p(p, "name").unwrap_or("Comp 1").to_string();
     let rate = rate_p(p).unwrap_or(FrameRate::FPS_29_97);
     let mut c = Comp::new(1920, 1080, rate, rate.snap_nearest(Tick::from_seconds_f64(10.0)));
@@ -119,6 +134,7 @@ fn new_comp(s: &mut Session, p: &Value) -> Result<Value> {
 }
 
 fn settings(s: &mut Session, p: &Value) -> Result<Value> {
+    check_rate(p, "comp.settings")?;
     let cid = comp_id(s, p)?;
     s.edit("Composition Settings", None, |proj, _| {
         if let Some(n) = str_p(p, "name")
@@ -252,7 +268,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "New Composition...",
             ["Composition"],
             Some("Cmd+N"),
-            "{name?, width?, height?, frameRate?, duration? (s), startTime? (s) | startTimecode?, background? [r,g,b]|#hex, pixelAspect?, shutterAngle?, shutterPhase?, motionBlurSamples?, adaptiveSampleLimit? (16–256), renderer? classic3D|advanced3D, anchor?, open?}",
+            "{name?, width?, height?, frameRate?, duration? (s), startTime? (s) | startTimecode?, background? [r,g,b]|#hex, pixelAspect?, shutterAngle?, shutterPhase?, motionBlurSamples?, adaptiveSampleLimit? (16–256), preserveFrameRate?: bool, preserveResolution?: bool, renderer? classic3D|advanced3D, anchor?, open?}",
             always,
             new_comp
         ),
@@ -261,7 +277,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Composition Settings...",
             ["Composition"],
             Some("Cmd+K"),
-            "{comp?, name?, width?, height?, anchor? 0-8 (resize anchor, 4 = center), frameRate?, duration?, startTime? (s) | startTimecode?, background?, shutterAngle?, shutterPhase?, motionBlurSamples?, adaptiveSampleLimit? (16–256), pixelAspect?, renderer? classic3D|advanced3D}",
+            "{comp?, name?, width?, height?, anchor? 0-8 (resize anchor, 4 = center), frameRate?, duration?, startTime? (s) | startTimecode?, background?, shutterAngle?, shutterPhase?, motionBlurSamples?, adaptiveSampleLimit? (16–256), preserveFrameRate?: bool (nested or in the render queue it shows only its own frames), preserveResolution?: bool (nested, it renders at full size), pixelAspect?, renderer? classic3D|advanced3D}",
             has_comp,
             settings
         ),

crates/engine/src/commands/edit.rs

@@ -1,7 +1,7 @@
 //! Edit menu.
 
 use effectcraft_color::Label;
-use effectcraft_project::{Expression, ItemKind, Layer, LayerId, LayerSource};
+use effectcraft_project::{Comp, Expression, ItemKind, Layer, LayerId, LayerSource, TrackMatte};
 use effectcraft_time::Tick;
 use serde_json::{Value, json};
 
@@ -60,8 +60,9 @@ fn select_all(s: &mut Session, _: &Value) -> Result<Value> {
     if let Some(r) = super::puppet::select_all_of_kind(s) {
         return Ok(r);
     }
+    // Locked layers (and shy layers while they are hidden) can't be selected.
     if let Some(c) = s.active_comp() {
-        s.state.selected_layers = c.layers.iter().map(|l| l.id).collect();
+        s.state.selected_layers = c.layers.iter().filter(|l| super::selectable(c, l)).map(|l| l.id).collect();
     }
     Ok(json!(s.state.selected_layers.len()))
 }
@@ -73,6 +74,17 @@ fn deselect_all(s: &mut Session, _: &Value) -> Result<Value> {
     Ok(Value::Null)
 }
 
+/// Copied layers keep their parent and track matte: the copy of that layer when it was copied
+/// too, else the layer itself when it is in `comp`, else none. `map`: (original, copy).
+fn relink_copies(comp: &mut Comp, map: &[(LayerId, LayerId)]) {
+    let present: Vec<LayerId> = comp.layers.iter().map(|l| l.id).collect();
+    let link = |id: LayerId| map.iter().find(|(o, _)| *o == id).map(|(_, c)| *c).or(present.contains(&id).then_some(id));
+    for l in comp.layers.iter_mut().filter(|l| map.iter().any(|(_, c)| *c == l.id)) {
+        l.parent = l.parent.and_then(link);
+        l.track_matte = l.track_matte.and_then(|m| link(m.layer).map(|layer| TrackMatte { layer, ..m }));
+    }
+}
+
 /// Fresh ids for a copied layer (and its property uids).
 pub(crate) fn reid(layer: &mut Layer, next: &mut u64) {
     layer.id = LayerId(*next);
@@ -98,14 +110,17 @@ fn duplicate(s: &mut Session, p: &Value) -> Result<Value> {
         let mut next = proj.next_id;
         let comp = proj.comp_mut(cid).ok_or(crate::EngineError::NoComp)?;
         let mut created = vec![];
+        let mut map = vec![];
         for id in &ids {
             let Some(i) = comp.layers.iter().position(|l| l.id == *id) else { continue };
             let mut l = comp.layers[i].clone();
             reid(&mut l, &mut next);
             l.name = comp.unique_layer_name(&l.name);
             created.push(l.id);
+            map.push((*id, l.id));
             comp.layers.insert(i, l);
         }
+        relink_copies(comp, &map);
         proj.next_id = next;
         st.selected_layers = created.clone();
         Ok(created)
@@ -133,12 +148,20 @@ fn delete(s: &mut Session, p: &Value) -> Result<Value> {
         return s.execute("effect.remove", json!({}));
     }
     let (cid, ids) = layers_p(s, p)?;
+    let ids = super::unlocked(s, cid, ids, "edit.clear")?;
+    // Children of deleted layers are unparented where they are (like After Effects).
+    let comp = s.project.comp(cid).ok_or(crate::EngineError::NoComp)?;
+    let orphans: Vec<LayerId> = comp.layers.iter().filter(|l| !ids.contains(&l.id) && l.parent.is_some_and(|p| ids.contains(&p))).map(|l| l.id).collect();
+    let fixes = super::layer::parent_fixes(s, cid, &orphans, None);
     s.edit("Clear", None, |proj, st| {
         let comp = proj.comp_mut(cid).ok_or(crate::EngineError::NoComp)?;
         comp.layers.retain(|l| !ids.contains(&l.id));
         for l in &mut comp.layers {
             if l.parent.is_some_and(|p| ids.contains(&p)) {
                 l.parent = None;
+                if let Some(f) = fixes.iter().find(|f| f.layer == l.id) {
+                    f.apply(l);
+                }
             }
             if l.track_matte.is_some_and(|m| ids.contains(&m.layer)) {
                 l.track_matte = None;
@@ -276,46 +299,6 @@ fn copy_expression_only(s: &mut Session, _: &Value) -> Result<Value> {
 }
 
 /// Paste the keyframe clipboard at the CTI onto the selected layers (same property paths).
-fn paste_keys(s: &mut Session, reversed: bool) -> Result<Value> {
-    let cid = s.active_comp_id().ok_or(EngineError::NoComp)?;
-    let ids = s.state.selected_layers.clone();
-    if ids.is_empty() {
-        return Err(EngineError::Other("select a layer to paste keyframes into".into()));
-    }
-    let clip = s.state.key_clipboard.clone();
-    let t = s.time();
-    let n = s.edit(if reversed { "Paste Reversed Keyframes" } else { "Paste Keyframes" }, None, |proj, st| {
-        let mut n = 0;
-        st.selected_keys.clear();
-        for lid in &ids {
-            let l = super::layer_mut(proj, cid, *lid)?;
-            let lt = l.layer_time(t);
-            for c in &clip {
-                let Some(pr) = l.props.prop_mut(&c.path) else { continue };
-                let span = c.keys.last().map(|k| k.time).unwrap_or(Tick::ZERO);
-                for k in &c.keys {
-                    let mut k = k.clone();
-                    if std::mem::discriminant(&k.value) != std::mem::discriminant(&pr.value) {
-                        continue;
-                    }
-                    if reversed {
-                        k.time = span - k.time;
-                        std::mem::swap(&mut k.in_interp, &mut k.out_interp);
-                        std::mem::swap(&mut k.in_ease, &mut k.out_ease);
-                        std::mem::swap(&mut k.spatial_in, &mut k.spatial_out);
-                    }
-                    k.time += lt;
-                    st.selected_keys.push(crate::KeyRef { layer: *lid, prop: pr.uid, time: k.time });
-                    effectcraft_keyframe::set_key(&mut pr.keys, k);
-                    n += 1;
-                }
-            }
-        }
-        Ok(n)
-    })?;
-    Ok(json!({"keys": n}))
-}
-
 fn paste_links(s: &mut Session, clip: LinkClip) -> Result<Value> {
     let cid = s.active_comp_id().ok_or(EngineError::NoComp)?;
     let ids = s.state.selected_layers.clone();
@@ -374,14 +357,16 @@ fn paste(s: &mut Session, p: &Value) -> Result<Value> {
         let comp = proj.comp_mut(cid).ok_or(crate::EngineError::NoComp)?;
         let at = st.selected_layers.first().and_then(|id| comp.layers.iter().position(|l| l.id == *id)).unwrap_or(0);
         let mut created = vec![];
+        let mut map = vec![];
         for (k, mut l) in clip.into_iter().enumerate() {
+            let original = l.id;
             reid(&mut l, &mut next);
             l.name = comp.unique_layer_name(&l.name);
-            l.parent = None;
-            l.track_matte = None;
             created.push(l.id);
+            map.push((original, l.id));
             comp.layers.insert(at + k, l);
         }
+        relink_copies(comp, &map);
         proj.next_id = next;
         st.selected_layers = created.clone();
         Ok(created)
@@ -445,8 +430,34 @@ fn label(s: &mut Session, p: &Value) -> Result<Value> {
     Ok(Value::Null)
 }
 
-fn paste_reversed(s: &mut Session, _: &Value) -> Result<Value> {
-    paste_keys(s, true)
+/// Edit ▸ Paste Reversed Keyframes: the copied keys mirrored in time over their whole span (the
+/// last key first, incoming and outgoing eases swapped), pasted like Edit ▸ Paste
+/// (`keys.paste`: at the current time, into the selected or the same properties).
+fn paste_reversed(s: &mut Session, p: &Value) -> Result<Value> {
+    let original = s.state.key_clipboard.clone();
+    let span = original.iter().flat_map(|c| c.keys.iter().map(|k| k.time)).max().unwrap_or(Tick::ZERO);
+    s.state.key_clipboard = original
+        .iter()
+        .map(|c| crate::KeyClip {
+            keys: c
+                .keys
+                .iter()
+                .rev()
+                .map(|k| {
+                    let mut k = k.clone();
+                    k.time = span - k.time;
+                    std::mem::swap(&mut k.in_interp, &mut k.out_interp);
+                    std::mem::swap(&mut k.in_ease, &mut k.out_ease);
+                    std::mem::swap(&mut k.spatial_in, &mut k.spatial_out);
+                    k
+                })
+                .collect(),
+            ..c.clone()
+        })
+        .collect();
+    let r = s.execute("keys.paste", p.clone());
+    s.state.key_clipboard = original;
+    r
 }
 
 /// Lift (leave a gap) or extract (close the gap) the work area from the selected layers (all
@@ -544,6 +555,7 @@ fn purge_caches(s: &mut Session, p: &Value) -> Result<Value> {
     let disk = matches!(what.as_str(), "all" | "memoryAndDisk" | "disk");
     if memory {
         s.layer_cache.clear();
+        s.footage.purge();
     }
     let mut disk_entries = 0;
     if disk && let Some(dc) = &s.disk_cache {
@@ -556,7 +568,11 @@ fn purge_caches(s: &mut Session, p: &Value) -> Result<Value> {
     if matches!(what.as_str(), "all" | "image" | "memory" | "memoryAndDisk") {
         effectcraft_effects::roto::purge();
     }
-    s.events.push(crate::Event::PurgeCaches);
+    // The viewers' RAM preview goes with the memory purges (and the 3D one, whose renders it
+    // holds); purging the disk cache or the snapshot leaves it.
+    if memory || what == "3d" {
+        s.events.push(crate::Event::PurgeCaches);
+    }
     s.toast(format!("Purged {what} cache"));
     Ok(json!({"purged": what, "diskEntries": disk_entries}))
 }
@@ -637,7 +653,7 @@ pub fn specs() -> Vec<CommandSpec> {
         ),
         cmd!("edit.copyExpressionOnly", "Copy Expression Only", ["Edit"], None, "{}", has_props_or_layers, copy_expression_only),
         cmd!("edit.paste", "Paste", ["Edit"], Some("Cmd+V"), "{} (layers, keyframes at the CTI, or property links / expressions)", has_clip, paste),
-        cmd!("edit.pasteReversedKeyframes", "Paste Reversed Keyframes", ["Edit"], None, "{}", has_key_clip, paste_reversed),
+        cmd!("edit.pasteReversedKeyframes", "Paste Reversed Keyframes", ["Edit"], None, "{layers?, prop?|path?, time?}", has_key_clip, paste_reversed),
         cmd!("edit.clear", "Clear", ["Edit"], Some("Delete"), "{layers?}", layers_or_keys, delete),
         cmd!("edit.duplicate", "Duplicate", ["Edit"], Some("Cmd+D"), "{layers?}", has_layers, duplicate),
         cmd!("edit.splitLayer", "Split Layer", ["Edit"], Some("Cmd+Shift+D"), "{layers?}", has_layers, split),

crates/engine/src/commands/effect.rs

@@ -4,7 +4,7 @@ use effectcraft_project::build::Ids;
 use effectcraft_project::{GroupKind, LayerId, PropGroup, Uid};
 use serde_json::{Value, json};
 
-use super::{CommandSpec, b_p, bad, has_layers, layer_mut, layers_p, str_p};
+use super::{CommandSpec, b_p, bad, f_p, has_layers, layer_mut, layers_p, str_p};
 use crate::{EngineError, Result, Session, cmd};
 
 /// `effect.plugins.list`: the registered plug-in effects (WebAssembly or Rust).
@@ -132,6 +132,52 @@ fn find_fx(s: &Session, p: &Value, cmd: &str) -> Result<(effectcraft_project::It
     Ok((cid, lid, g.uid))
 }
 
+/// A colour parameter's eyedropper on a keyer (Effect Controls): the colour of the effect's input
+/// (the layer's pixels before this effect, so a keyed screen can still be picked) at a
+/// layer-space point, set on the parameter. `average` takes the 5 × 5 pixels around it.
+fn pick_color(s: &mut Session, p: &Value) -> Result<Value> {
+    let cmd = "effect.pickColor";
+    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 comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let layer = comp.layer(lid).ok_or(EngineError::NoComp)?;
+    let fx = layer.effects().ok_or_else(|| bad(cmd, "no effects"))?;
+    let index = fx.groups().position(|g| g.uid == fx_uid).ok_or_else(|| bad(cmd, "no such effect"))?;
+    let g = fx.groups().nth(index).ok_or_else(|| bad(cmd, "no such effect"))?;
+    let prop = match (p.get("prop").and_then(Value::as_u64), str_p(p, "param")) {
+        (Some(uid), _) => g.find(uid),
+        (None, Some(path)) => g.prop(path),
+        _ => return Err(bad(cmd, "missing `param` (e.g. `screenColour`) or `prop` (uid)")),
+    }
+    .filter(|pr| pr.ui == effectcraft_project::ParamUi::Color)
+    .ok_or_else(|| bad(cmd, "not a colour parameter of this 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 mut r = effectcraft_render::Renderer::new(&s.project, &*s.footage, effectcraft_render::RenderOpts::default());
+    r.expr = s.expr.as_deref();
+    r.cache = Some(&s.layer_cache);
+    let buf = r.layer_input(&ctx, layer, index).ok_or_else(|| bad(cmd, "this layer has no pixels"))?;
+    let (px, py) = buf.to_px([x, y]);
+    let (cx, cy) = (px.floor() as i64, py.floor() as i64);
+    let rad = if b_p(p, "average") == Some(true) { 2 } else { 0 };
+    let mut sum = [0.0f32; 4];
+    for yy in cy.saturating_sub(rad)..=cy.saturating_add(rad) {
+        for xx in cx.saturating_sub(rad)..=cx.saturating_add(rad) {
+            // Outside the layer reads as transparent.
+            let c = buf.img.get(xx, yy);
+            (0..4).for_each(|i| sum[i] += c[i]);
+        }
+    }
+    if sum[3] <= 1e-6 {
+        return Err(bad(cmd, "nothing to sample there (transparent or outside the layer)"));
+    }
+    // Straight colour of the (averaged) premultiplied pixels.
+    let color: Vec<f64> = (0..3).map(|i| (sum[i] / sum[3]).clamp(0.0, 1.0) as f64).chain([1.0]).collect();
+    let uid = prop.uid;
+    s.execute("prop.set", json!({"comp": cid.0, "layer": lid.0, "prop": uid, "value": color}))?;
+    Ok(json!({"prop": uid, "color": color}))
+}
+
 fn remove(s: &mut Session, p: &Value) -> Result<Value> {
     let cid = super::comp_id(s, p)?;
     let fx = effects_p(s, p, "effect.remove")?;
@@ -355,11 +401,11 @@ fn last(s: &mut Session, p: &Value) -> Result<Value> {
 }
 
 fn list(_: &mut Session, p: &Value) -> Result<Value> {
-    let filter = str_p(p, "filter").map(str::to_ascii_lowercase);
+    let filter = str_p(p, "filter").map(str::to_lowercase);
     let v: Vec<Value> = effectcraft_effects::all()
         .into_iter()
         .filter(|e| {
-            filter.as_ref().is_none_or(|f| e.name.to_ascii_lowercase().contains(f) || e.id.contains(f.as_str()) || e.category.to_ascii_lowercase().contains(f))
+            filter.as_ref().is_none_or(|f| effectcraft_effects::name_matches(e, f) || e.id.contains(f.as_str()) || e.category.to_ascii_lowercase().contains(f))
         })
         .map(|e| {
             json!({"id": e.id, "name": e.name, "category": e.category, "gpu": e.gpu, "float": e.float, "params": e.params.iter().map(|p| json!({"id": p.id, "name": p.name, "default": p.default.to_json()})).collect::<Vec<_>>()})
@@ -371,6 +417,15 @@ fn list(_: &mut Session, p: &Value) -> Result<Value> {
 pub fn specs() -> Vec<CommandSpec> {
     vec![
         cmd!("effect.apply", "Apply Effect", [], None, "{effect: id|name (e.g. Gaussian Blur), layers?}", has_layers, apply),
+        cmd!(
+            "effect.pickColor",
+            "Pick Effect Colour",
+            [],
+            None,
+            "{layer?, effect?: index|uid|name, param: id (e.g. screenColour) | prop: uid, x, y (layer px), average?: bool (5×5), time?} — the colour of the effect's input there",
+            has_layers,
+            pick_color
+        ),
         cmd!("effect.applyLast", "Last Effect", ["Effect"], Some("Cmd+Alt+Shift+E"), "{layers?}", has_layers, last),
         cmd!("effect.removeAll", "Remove All", ["Effect"], Some("Cmd+Shift+E"), "{layers?}", has_layers, remove_all),
         cmd!("effect.remove", "Remove Effect", [], None, "{layer?, effect: index|uid|name}", has_layers, remove),

crates/engine/src/commands/expr_tools.rs

@@ -2,7 +2,7 @@
 //! Language menu (the ⓕ button next to an expression), written from the public Expression
 //! Language Reference.
 
-use effectcraft_project::{ItemId, Layer, Property};
+use effectcraft_project::{Expression, ItemId, Layer, Property};
 use effectcraft_render::EvalCtx;
 use effectcraft_time::Tick;
 use serde::Serialize;
@@ -45,14 +45,13 @@ pub fn errors(s: &Session, cid: ItemId, t: Tick) -> Vec<ExprError> {
     let ctx = EvalCtx { footage: Some(s.footage.as_ref()), expr: s.expr.as_deref(), ..EvalCtx::new(&s.project, cid, comp, t) };
     let mut out = vec![];
     for (i, l) in comp.layers.iter().enumerate() {
-        let mut props: Vec<&Property> = vec![];
+        let mut props: Vec<(&Property, &Expression)> = vec![];
         l.props.walk("", &mut |_, p| {
-            if p.expr.as_ref().is_some_and(|e| !e.text.trim().is_empty()) {
-                props.push(p);
+            if let Some(e) = p.expr.as_ref().filter(|e| !e.text.trim().is_empty()) {
+                props.push((p, e));
             }
         });
-        for p in props {
-            let e = p.expr.as_ref().expect("filtered");
+        for (p, e) in props {
             let msg = if e.enabled {
                 match &ctx.expr {
                     Some(h) => h.eval(&ctx, l, p, &p.value_at(l.layer_time(t))).err(),

crates/engine/src/commands/file.rs

@@ -42,21 +42,35 @@ pub(crate) fn open(s: &mut Session, p: &Value) -> Result<Value> {
     let text = String::from_utf8(bytes).map_err(|_| EngineError::Other("not a text project file".into()))?;
     // XML copies (File ▸ Save a Copy As XML…) open like the JSON project.
     let text = if crate::xml_project::is_xml(&text) { crate::xml_project::from_xml(&text).map_err(EngineError::Other)? } else { text };
-    let proj = Project::from_json(&text)?;
+    let proj = Project::from_json(&text).map_err(|e| EngineError::Other(format!("{path} is not a project EffectCraft can open: {e}")))?;
     s.replace_project(proj, Some(path.to_string()));
     s.note_project_path(path);
+    // Written by a newer EffectCraft: what this version doesn't know would be lost on saving.
+    let saved_by = effectcraft_project::saved_by(&text);
+    if let Some(v) = saved_by.as_deref().filter(|v| effectcraft_project::is_newer_version(v, effectcraft_project::APP_VERSION)) {
+        s.toast(format!(
+            "This project was saved by EffectCraft {v}, newer than this version ({}). Settings this version doesn't know are lost if you save it.",
+            effectcraft_project::APP_VERSION
+        ));
+    }
     // Lazy open: footage is checked in the background (Progress panel), not before the
     // project shows.
     if s.check_footage_on_open {
         crate::footage_check::start(s, None, false)?;
     }
-    Ok(json!({"path": path}))
+    Ok(json!({"path": path, "savedBy": saved_by}))
+}
+
+/// The project file's text for `path`: `.ecproj` JSON, or XML for `.ecprojx` / `.xml` (a
+/// project opened from an XML copy saves as XML again). Fails, writing nothing, when the project
+/// wouldn't read back.
+pub(crate) fn file_text(s: &Session, path: &str) -> Result<String> {
+    let json = s.project.to_file_json()?;
+    if crate::xml_project::is_xml_path(path) { crate::xml_project::to_xml(&json).map_err(EngineError::Other) } else { Ok(json) }
 }
 
 fn save_to(s: &mut Session, path: &str) -> Result<Value> {
-    let json = s.project.to_json();
-    // A project opened from an XML copy saves as XML again.
-    let json = if crate::xml_project::is_xml_path(path) { crate::xml_project::to_xml(&json).map_err(EngineError::Other)? } else { json };
+    let json = file_text(s, path)?;
     s.services.write_file(path, json.as_bytes()).map_err(|e| EngineError::Other(format!("cannot write {path}: {e}")))?;
     s.path = Some(path.to_string());
     s.mark_saved();

crates/engine/src/commands/file_more.rs

@@ -9,7 +9,7 @@ use effectcraft_project::{AlphaMode, Comp, Footage, FootageKind, ItemId, ItemKin
 use effectcraft_time::{FrameRate, Tick};
 use serde_json::{Value, json};
 
-use super::{CommandSpec, always, bad, f_p, has_comp, has_project_selection, str_p};
+use super::{CommandSpec, always, b_p, bad, f_p, has_comp, has_project_selection, str_p};
 use crate::{EngineError, Result, Session, cmd};
 
 fn has_footage_selection(s: &Session) -> std::result::Result<(), String> {
@@ -77,7 +77,7 @@ fn close_project(s: &mut Session, _: &Value) -> Result<Value> {
 
 fn save_copy(s: &mut Session, p: &Value) -> Result<Value> {
     let path = str_p(p, "path").ok_or_else(|| bad("file.saveCopy", "missing `path`"))?;
-    let json = s.project.to_json();
+    let json = super::file::file_text(s, path)?;
     s.services.write_file(path, json.as_bytes()).map_err(|e| EngineError::Other(format!("cannot write {path}: {e}")))?;
     Ok(json!({"path": path, "bytes": json.len()}))
 }
@@ -150,29 +150,88 @@ fn import_solid(s: &mut Session, p: &Value) -> Result<Value> {
     Ok(json!({"item": id.0}))
 }
 
+/// File ▸ New Comp from Selection. Each selected item becomes a composition of its size, pixel
+/// aspect, frame rate and duration holding it as a layer; with `single`, one composition holds
+/// them all (first selected on top), with the settings of item `dimensionsFrom` (an index into
+/// the selection, default 0), as long as the longest item, or with `sequence` the layers one
+/// after another (Sequence Layers: `overlap`, `overlapDuration` seconds, `transition`).
+/// `duration`: seconds for stills (default: Settings ▸ Import ▸ Still Footage when it is a
+/// duration, else 10 s).
+/// `addToRenderQueue` queues the new compositions. One undo step.
 fn new_comp_from_selection(s: &mut Session, p: &Value) -> Result<Value> {
     let items: Vec<ItemId> = s.state.project_selection.iter().copied().filter(|i| s.project.item(*i).is_some_and(|x| !x.is_folder())).collect();
     if items.is_empty() {
         return Err(bad("file.newCompFromSelection", "select footage in the Project panel"));
     }
-    let mut made = vec![];
-    for item in items {
-        let it = s.project.item(item).ok_or(EngineError::NoComp)?.clone();
-        let (w, h) = it.dimensions().unwrap_or((1920, 1080));
-        let rate = it.frame_rate().unwrap_or(FrameRate::FPS_29_97);
-        let dur = it.duration().filter(|d| *d > Tick::ZERO).unwrap_or(Tick::from_seconds_f64(f_p(p, "duration").unwrap_or(10.0)));
-        let name = it.name.rsplit_once('.').map(|(a, _)| a.to_string()).unwrap_or(it.name.clone());
-        let c = Comp::new(w.max(1), h.max(1), rate, dur);
-        let cid = s.edit("New Comp from Selection", None, |proj, st| {
-            let cid = proj.add_item(&name, Label::Sandstone, None, ItemKind::Comp(c.into()));
-            st.project_selection = vec![cid];
-            Ok(cid)
-        })?;
-        s.open_comp(cid);
-        s.execute("layer.addItem", json!({"comp": cid.0, "item": item.0}))?;
-        made.push(cid.0);
+    let single = b_p(p, "single").unwrap_or(false) && items.len() > 1;
+    let from = p.get("dimensionsFrom").and_then(Value::as_u64).unwrap_or(0) as usize;
+    if single && from >= items.len() {
+        return Err(bad("file.newCompFromSelection", format!("`dimensionsFrom` must be below {}", items.len())));
     }
-    Ok(json!({"comps": made}))
+    let still = f_p(p, "duration")
+        .or((s.prefs.import.still_footage == "seconds").then_some(s.prefs.import.still_seconds))
+        .filter(|d| d.is_finite() && *d > 0.0)
+        .unwrap_or(10.0);
+    // Layer ▸ Keyframe Assistant ▸ Sequence Layers' parameters.
+    let sequence = b_p(p, "sequence").unwrap_or(false).then(|| {
+        json!({
+            "overlap": b_p(p, "overlap").unwrap_or(false),
+            "duration": f_p(p, "overlapDuration").filter(|d| d.is_finite() && *d >= 0.0).unwrap_or(1.0),
+            "transition": str_p(p, "transition").unwrap_or("off"),
+        })
+    });
+    let queue = b_p(p, "addToRenderQueue").unwrap_or(false);
+    let proj = s.project.clone();
+    let duration = |i: ItemId| proj.item(i).and_then(|it| it.duration()).filter(|d| *d > Tick::ZERO).unwrap_or(Tick::from_seconds_f64(still));
+    let groups: Vec<Vec<ItemId>> = if single { vec![items.clone()] } else { items.iter().map(|i| vec![*i]).collect() };
+    super::app_more::grouped(s, "New Comp from Selection", |s| {
+        let mut made = vec![];
+        for g in groups {
+            let lead = g.get(if single { from } else { 0 }).and_then(|i| proj.item(*i)).ok_or(EngineError::NoComp)?;
+            let (w, h) = lead.dimensions().unwrap_or((1920, 1080));
+            let rate = lead.frame_rate().unwrap_or(FrameRate::FPS_29_97);
+            let pixel_aspect = match &lead.kind {
+                ItemKind::Footage(f) => f.pixel_aspect,
+                ItemKind::Solid(so) => so.pixel_aspect,
+                ItemKind::Comp(c) => c.pixel_aspect,
+                ItemKind::Folder => 1.0,
+            };
+            let overlap =
+                sequence.as_ref().filter(|q| q["overlap"] == true).map_or(Tick::ZERO, |q| Tick::from_seconds_f64(q["duration"].as_f64().unwrap_or(1.0)));
+            let dur = match &sequence {
+                Some(_) if g.len() > 1 => g.iter().map(|i| duration(*i)).fold(Tick::ZERO, |a, d| a + d) - Tick(overlap.0.saturating_mul(g.len() as i64 - 1)),
+                _ => g.iter().map(|i| duration(*i)).max().unwrap_or(Tick::from_seconds_f64(still)),
+            }
+            .max(rate.frame_duration());
+            let name = lead.name.rsplit_once('.').map(|(a, _)| a.to_string()).unwrap_or(lead.name.clone());
+            let c = Comp { pixel_aspect, ..Comp::new(w.max(1), h.max(1), rate, dur) };
+            let cid = s.edit("New Comp from Selection", None, |proj, st| {
+                let cid = proj.add_item(&name, Label::Sandstone, None, ItemKind::Comp(c.into()));
+                st.project_selection = vec![cid];
+                Ok(cid)
+            })?;
+            s.open_comp(cid);
+            // Added bottom first, so the first selected ends up on top.
+            let mut layers = vec![];
+            for item in g.iter().rev() {
+                layers.push(s.execute("layer.addItem", json!({"comp": cid.0, "item": item.0, "duration": still}))?["layer"].clone());
+            }
+            layers.reverse();
+            if let Some(q) = &sequence
+                && layers.len() > 1
+            {
+                let mut q = q.clone();
+                q["comp"] = json!(cid.0);
+                q["layers"] = json!(layers);
+                s.execute("layer.sequence", q)?;
+            }
+            if queue {
+                s.execute("renderQueue.add", json!({"comp": cid.0}))?;
+            }
+            made.push(cid.0);
+        }
+        Ok(json!({"comps": made}))
+    })
 }
 
 // ---------------------------------------------------------------- dependencies
@@ -834,7 +893,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "New Comp from Selection...",
             ["File"],
             Some("Cmd+Alt+\\"),
-            "{duration? (s, for stills)}",
+            "{duration? (s, for stills), single?: bool (one comp for all), dimensionsFrom?: index, sequence?: bool, overlap?: bool, overlapDuration? (s), transition?: off|dissolveFront|crossDissolve, addToRenderQueue?: bool} → {comps}",
             has_project_selection,
             new_comp_from_selection
         ),

crates/engine/src/commands/frontend.rs

@@ -85,7 +85,7 @@ pub fn specs() -> Vec<CommandSpec> {
         fe!("window.saveWorkspaceAs", "Save as New Workspace...", ["Window", "Workspace"], None, "{name}", always),
         fe!("window.editWorkspaces", "Edit Workspaces...", ["Window", "Workspace"], None, "{name, rename?: new name, delete?: bool}", always),
         fe!("window.resetWorkspace", "Reset to Saved Layout", ["Window", "Workspace"], None, "{}", always),
-        fe!("comp.flowchart", "Composition Flowchart", ["Composition"], Some("Cmd+F11"), "{}", always),
+        fe!("comp.flowchart", "Composition Flowchart", ["Composition"], Some("Cmd+Shift+F11"), "{}", always),
         fe!("comp.miniFlowchart", "Composition Mini-Flowchart", ["Composition"], Some("Tab"), "{}", has_comp),
         fe!("layer.openLayer", "Open Layer", ["Layer"], None, "{layer?}", has_layers),
         fe!("effect.manage", "Manage Effects...", ["Effect"], None, "{}", always),

crates/engine/src/commands/help.rs

@@ -47,7 +47,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Other ArtCraft Apps",
             [],
             None,
-            "{app: photocraft|drawcraft|filmcraft|lightcraft|printcraft|designcraft, kind?: page|github}",
+            "{app: photocraft|vectorcraft|filmcraft|lightcraft|printcraft|designcraft, kind?: page|github}",
             always,
             sibling
         ),

crates/engine/src/commands/key_transform.rs

@@ -19,11 +19,25 @@ fn v3(v: Option<&Value>) -> Option<[f64; 3]> {
 /// Transform the selected keys: times scale about `timeAnchor` (comp seconds, default the first
 /// selected key) by `timeScale` and move by `timeOffset`; values scale about `valueAnchor` by
 /// `valueScale` and move by `valueOffset` (every dimension, or only `dim`). Times land on frames.
+/// With `fromStart` (drags), each step of one merged gesture gives the whole transform since the
+/// drag started and applies to the keys as they were then: keys squeezed onto one frame on the
+/// way, or rounded steps, are never lost; only the final position counts.
 fn transform(s: &mut Session, p: &Value) -> Result<Value> {
     let cid = s.active_comp_id().ok_or(EngineError::NoComp)?;
-    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let merge = merge_p(p);
+    let from_start = b_p(p, "fromStart").unwrap_or(false) && merge.is_some();
+    let gesture = from_start && merge.is_some_and(|m| s.history.merge_key.as_deref() == Some(m)) && s.key_move.as_ref().map(|g| g.merge.as_str()) == merge;
+    let (sel, base) = match (&s.key_move, s.history.undo.last()) {
+        (Some(g), Some((_, b))) if gesture => (g.from.clone(), Some(b.clone())),
+        _ => (s.state.selected_keys.clone(), None),
+    };
+    if from_start {
+        s.key_move = merge.map(|m| crate::KeyMove { merge: m.to_string(), from: sel.clone(), total: Tick::ZERO });
+    }
+    // The comp as it was when the drag started (its keys are what the transform applies to).
+    let start = base.clone().unwrap_or_else(|| s.project.clone());
+    let comp = start.comp(cid).ok_or(EngineError::NoComp)?;
     let fr = comp.frame_rate;
-    let sel = s.state.selected_keys.clone();
     let ts = f_p(p, "timeScale").unwrap_or(1.0);
     let toff = f_p(p, "timeOffset").unwrap_or(0.0);
     let vs = f_p(p, "valueScale").unwrap_or(1.0);
@@ -46,7 +60,10 @@ fn transform(s: &mut Session, p: &Value) -> Result<Value> {
         fr.snap_nearest(Tick::from_seconds_f64(x.max(0.0)))
     };
     let touch_values = vs != 1.0 || voff != 0.0;
-    s.edit("Transform Keyframes", merge_p(p), |proj, st| {
+    s.edit("Transform Keyframes", merge, |proj, st| {
+        if let Some(b) = base {
+            *proj = (*b).clone();
+        }
         let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
         let mut groups: std::collections::BTreeMap<(LayerId, Uid), Vec<Tick>> = Default::default();
         for k in &sel {
@@ -136,7 +153,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Transform Keyframes",
             [],
             None,
-            "{timeScale?, timeAnchor? (comp s), timeOffset? (s), valueScale?, valueAnchor?, valueOffset?, dim? | dims?: [d…], merge?}",
+            "{timeScale?, timeAnchor? (comp s), timeOffset? (s), valueScale?, valueAnchor?, valueOffset?, dim? | dims?: [d…], merge?, fromStart?: bool (with merge: values are the whole transform since the drag started)}",
             has_keys,
             transform
         ),

crates/engine/src/commands/layer.rs

@@ -9,7 +9,7 @@ use effectcraft_project::{
 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};
+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]> {
@@ -49,11 +49,12 @@ fn new_solid_like(s: &mut Session, p: &Value, adjustment: bool) -> Result<Value>
     let color = color_p(p, "color").unwrap_or(if adjustment { [1.0, 1.0, 1.0] } else { [0.85, 0.2, 0.2] });
     let w = p.get("width").and_then(Value::as_u64).map(|v| v as u32).unwrap_or(comp.width);
     let h = p.get("height").and_then(Value::as_u64).map(|v| v as u32).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: comp.pixel_aspect }));
+        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;
@@ -64,6 +65,14 @@ fn new_solid_like(s: &mut Session, p: &Value, adjustment: bool) -> Result<Value>
     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),
+    }
+}
+
 fn new_solid(s: &mut Session, p: &Value) -> Result<Value> {
     new_solid_like(s, p, false)
 }
@@ -237,8 +246,12 @@ fn add_item(s: &mut Session, p: &Value) -> Result<Value> {
     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 => {
-            // Settings ▸ Import ▸ Still Footage: length of the composition or a duration.
-            let d = (s.prefs.import.still_footage == "seconds").then(|| Tick::from_seconds_f64(s.prefs.import.still_seconds));
+            // `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 => {
@@ -306,17 +319,17 @@ fn select_step(s: &mut Session, p: &Value, dir: i64) -> Result<Value> {
     }
     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;
-    let i = match cur {
-        Some(i) => (i as i64 + dir).clamp(0, n - 1),
-        None => {
-            if dir > 0 {
-                0
-            } else {
-                n - 1
-            }
-        }
-    } as usize;
-    let id = comp.layers[i].id;
+    // 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) {
@@ -504,6 +517,101 @@ fn track_matte(s: &mut Session, p: &Value) -> Result<Value> {
     Ok(Value::Null)
 }
 
+/// How a 2D layer's transform changes so it stays where it is when its parent changes.
+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],
+}
+
+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 };
+        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]])
+            });
+        }
+    }
+}
+
+/// Like the pick-whip, a parent change keeps 2D layers where they are: their transform 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);
+    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 }
+        })
+        .collect()
+}
+
 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)?;
@@ -524,59 +632,13 @@ fn set_parent(s: &mut Session, p: &Value) -> Result<Value> {
     // 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 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 })
-    };
-    // Per layer: (id, position transform, rotation delta, scale factors).
-    let mut fixes: Vec<(LayerId, effectcraft_geom::Mat3, f64, [f64; 2])> = vec![];
-    if compensate {
-        let new_m = space(parent);
-        for l in comp.layers.iter().filter(|l| ids.contains(&l.id) && !l.is_3d() && l.parent != parent) {
-            let old_m = space(l.parent);
-            let Some(inv) = new_m.inverse() else { continue };
-            let (ro, sxo, syo) = decompose(&old_m);
-            let (rn, sxn, syn) = decompose(&new_m);
-            let k = [if sxn.abs() > 1e-12 { sxo / sxn } else { 1.0 }, if syn.abs() > 1e-12 { syo / syn } else { 1.0 }];
-            fixes.push((l.id, inv * old_m, ro - rn, k));
-        }
-    }
+    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;
-            let Some((_, m, dr, k)) = fixes.iter().find(|f| f.0 == l.id) else { continue };
-            let Some(tr) = l.props.sub_mut("transform") else { continue };
-            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);
-                }
-            };
-            if tr.get("positionX").is_none()
-                && 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]])
-                });
-            }
-            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]])
-                });
+            if let Some(f) = fixes.iter().find(|f| f.layer == l.id) {
+                f.apply(l);
             }
         }
         Ok(())
@@ -687,6 +749,7 @@ fn slip(s: &mut Session, p: &Value) -> Result<Value> {
 
 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).
@@ -703,10 +766,29 @@ fn arrange(s: &mut Session, p: &Value) -> Result<Value> {
     };
     s.edit("Arrange Layers", None, |proj, _| {
         let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        let n = comp.layers.len();
+        // 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();
-        let first_idx = comp.layers.iter().position(|l| ids.contains(&l.id)).unwrap_or(0);
-        let last_idx = comp.layers.iter().rposition(|l| ids.contains(&l.id)).unwrap_or(0);
         comp.layers.retain(|l| {
             if ids.contains(&l.id) {
                 picked.push(l.clone());
@@ -718,13 +800,9 @@ fn arrange(s: &mut Session, p: &Value) -> Result<Value> {
         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()),
-            ("front", _) => 0,
             ("back", _) => comp.layers.len(),
-            ("forward", _) => first_idx.saturating_sub(1),
-            ("backward", _) => (last_idx + 2 - picked.len()).min(comp.layers.len()),
             _ => 0,
         };
-        let _ = n;
         for (k, l) in picked.into_iter().enumerate() {
             comp.layers.insert((at + k).min(comp.layers.len()), l);
         }
@@ -766,8 +844,7 @@ fn precompose(s: &mut Session, p: &Value) -> Result<Value> {
             _ => comp.duration,
         };
         let new = s.edit("Pre-compose", None, |proj, st| {
-            let mut inner = Comp::new(w, h, comp.frame_rate, dur);
-            inner.background = comp.background;
+            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);
@@ -791,8 +868,7 @@ fn precompose(s: &mut Session, p: &Value) -> Result<Value> {
     };
     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::new(comp.width, comp.height, comp.frame_rate, dur);
-        inner.background = comp.background;
+        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)) {
@@ -955,8 +1031,8 @@ fn set_text(s: &mut Session, p: &Value) -> Result<Value> {
         && 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 e = s.state.text_edit.as_mut().expect("checked");
         let mut st = e.pending.clone().unwrap_or_else(|| doc.insertion_style(r.start));
         let mut any = false;
         for (k, v) in obj {
@@ -990,8 +1066,26 @@ fn set_text(s: &mut Session, p: &Value) -> Result<Value> {
     Ok(Value::Null)
 }
 
+/// 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));
+    }
+}
+
 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();
@@ -1012,7 +1106,7 @@ fn transform_op(s: &mut Session, p: &Value) -> Result<Value> {
             match op.as_str() {
                 "reset" => {
                     set(tr, "anchor", KV::Vec3([w / 2.0, h / 2.0, 0.0]));
-                    set(tr, "position", KV::Vec3([cw / 2.0, ch / 2.0, 0.0]));
+                    update_position(tr, lt, |_| [cw / 2.0, ch / 2.0, 0.0]);
                     set(tr, "scale", KV::Vec3([100.0; 3]));
                     set(tr, "rotation", KV::Scalar(0.0));
                     set(tr, "rotationX", KV::Scalar(0.0));
@@ -1020,16 +1114,19 @@ fn transform_op(s: &mut Session, p: &Value) -> Result<Value> {
                     set(tr, "orientation", KV::Vec3([0.0; 3]));
                     set(tr, "opacity", KV::Scalar(100.0));
                 }
-                "center" => set(tr, "position", KV::Vec3([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),
                     };
-                    set(tr, "scale", KV::Vec3([sx * 100.0, sy * 100.0, 100.0]));
-                    set(tr, "position", KV::Vec3([cw / 2.0, ch / 2.0, 0.0]));
-                    set(tr, "anchor", KV::Vec3([w / 2.0, h / 2.0, 0.0]));
+                    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]);
@@ -1044,6 +1141,11 @@ fn transform_op(s: &mut Session, p: &Value) -> Result<Value> {
     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).
@@ -1053,32 +1155,53 @@ fn layer_settings(s: &mut Session, p: &Value) -> Result<Value> {
         _ => {}
     }
     let color = color_p(p, "color");
-    let w = p.get("width").and_then(Value::as_u64).map(|v| v as u32);
-    let h = p.get("height").and_then(Value::as_u64).map(|v| v as u32);
-    let name = str_p(p, "name").map(str::to_string);
-    s.edit("Layer Settings", None, |proj, _| {
-        let l = layer_mut(proj, cid, lid)?;
+    let w = p.get("width").and_then(Value::as_u64).map(|v| v.max(1) as u32);
+    let h = p.get("height").and_then(Value::as_u64).map(|v| v.max(1) as u32);
+    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 {
-            l.name = n.clone();
+            layer_mut(proj, cid, lid)?.name = n.clone();
         }
-        let src = l.source.clone();
-        if let LayerSource::Solid { item } = src
-            && let Some(it) = proj.item_mut(item)
-            && let ItemKind::Solid(so) = &mut it.kind
-        {
-            if let Some(c) = color {
-                so.color = c;
-            }
-            if let Some(w) = w {
-                so.width = w.max(1);
-            }
-            if let Some(h) = h {
-                so.height = h.max(1);
-            }
+        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();
         }
-        Ok(())
+        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(Value::Null)
+    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 {
@@ -1098,7 +1221,7 @@ pub fn specs() -> Vec<CommandSpec> {
             has_comp,
             new_text
         ),
-        cmd!("layer.newSolid", "Solid...", ["Layer", "New"], Some("Cmd+Y"), "{name?, color? #hex|[r,g,b], width?, height?}", has_comp, new_solid),
+        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",
@@ -1110,8 +1233,16 @@ pub fn specs() -> Vec<CommandSpec> {
             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?}", has_layers, layer_settings),
-        cmd!("layer.addItem", "Add Footage to Comp", ["File"], Some("Cmd+/"), "{item: id|name, time?}", has_comp, add_item),
+        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?, duration? (s, for a still)}", has_comp, add_item),
         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),

crates/engine/src/commands/layer_menu.rs

@@ -209,6 +209,7 @@ fn set_transform(s: &mut Session, p: &Value) -> Result<Value> {
 
 fn center_anchor(s: &mut Session, p: &Value) -> Result<Value> {
     let (cid, ids) = layers_p(s, p)?;
+    let ids = super::unlocked(s, cid, ids, "layer.centerAnchor")?;
     let t = s.time();
     let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
     let ctx = effectcraft_render::EvalCtx::new(&s.project, cid, comp, t);
@@ -234,17 +235,25 @@ fn center_anchor(s: &mut Session, p: &Value) -> Result<Value> {
             if let Some(a) = tr.get_mut("anchor") {
                 a.set_value_at(lt, KV::Vec3([c[0], c[1], anchor[2]]));
             }
-            if let Some(pos) = tr.get_mut("position") {
-                // Shift every key so the layer stays put over its whole animation.
-                if pos.keys.is_empty() {
-                    let v = pos.value.as_vec3();
-                    pos.value = KV::Vec3([v[0] + shift[0], v[1] + shift[1], v[2]]);
-                } else {
-                    for k in &mut pos.keys {
-                        let v = k.value.as_vec3();
-                        k.value = KV::Vec3([v[0] + shift[0], v[1] + shift[1], v[2]]);
+            // Shift every key so the layer stays put over its whole animation (X and Y Position
+            // when the dimensions are separated).
+            let offset = |pr: &mut effectcraft_project::Property, f: &dyn Fn(&KV) -> KV| {
+                pr.value = f(&pr.value);
+                for k in &mut pr.keys {
+                    k.value = f(&k.value);
+                }
+            };
+            if tr.get("positionX").is_some() {
+                for (m, d) in [("positionX", shift[0]), ("positionY", shift[1])] {
+                    if let Some(pr) = tr.get_mut(m) {
+                        offset(pr, &|v| KV::Scalar(v.as_f64() + d));
                     }
                 }
+            } else if let Some(pr) = tr.get_mut("position") {
+                offset(pr, &|v| {
+                    let c = v.as_vec3();
+                    KV::Vec3([c[0] + shift[0], c[1] + shift[1], c[2]])
+                });
             }
         }
         Ok(())

crates/engine/src/commands/mod.rs

@@ -497,6 +497,33 @@ pub(crate) fn layers_p(s: &Session, p: &Value) -> Result<(ItemId, Vec<LayerId>)>
     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") {

crates/engine/src/commands/paths.rs

@@ -450,16 +450,8 @@ pub fn specs() -> Vec<CommandSpec> {
     vec![
         cmd!("path.rotoBezier", "RotoBezier", ["Layer", "Mask and Shape Path"], None, "{layer?, mask?, value?}", has_layers, roto_bezier),
         cmd!("path.convertToBezier", "Convert To Bezier Path", ["Layer", "Mask and Shape Path"], None, "{layer?, mask?}", has_layers, convert_to_bezier),
-        cmd!("path.groupShapes", "Group Shapes", ["Layer", "Mask and Shape Path"], Some("Cmd+G"), "{layer?, items?: [uid]}", has_shape_items, group_shapes),
-        cmd!(
-            "path.ungroupShapes",
-            "Ungroup Shapes",
-            ["Layer", "Mask and Shape Path"],
-            Some("Cmd+Shift+G"),
-            "{layer?, items?: [group uid]}",
-            has_shape_items,
-            ungroup_shapes
-        ),
+        cmd!("path.groupShapes", "Group Shapes", ["Layer"], Some("Cmd+G"), "{layer?, items?: [uid]}", has_shape_items, group_shapes),
+        cmd!("path.ungroupShapes", "Ungroup Shapes", ["Layer"], Some("Cmd+Shift+G"), "{layer?, items?: [group uid]}", has_shape_items, ungroup_shapes),
         cmd!(
             "path.setFirstVertex",
             "Set First Vertex",

crates/engine/src/commands/prop.rs

@@ -335,7 +335,19 @@ fn select_keys(s: &mut Session, p: &Value) -> Result<Value> {
             sel.push(KeyRef { layer: l, prop: pr.uid, time: kt });
         }
     }
-    if b_p(p, "add").unwrap_or(false) {
+    // Keys of locked layers can't be selected (so nothing edits them).
+    sel.retain(|k| comp.layer(k.layer).is_some_and(|l| !l.switches.locked));
+    if b_p(p, "toggle").unwrap_or(false) {
+        // Shift+click: in and out of the selection.
+        for k in sel {
+            match s.state.selected_keys.iter().position(|x| *x == k) {
+                Some(i) => {
+                    s.state.selected_keys.remove(i);
+                }
+                None => s.state.selected_keys.push(k),
+            }
+        }
+    } else if b_p(p, "add").unwrap_or(false) {
         for k in sel {
             if !s.state.selected_keys.contains(&k) {
                 s.state.selected_keys.push(k);
@@ -400,14 +412,72 @@ pub(crate) fn edit_keys(s: &mut Session, label: &str, merge: Option<&str>, f: im
     })
 }
 
+/// Move the selected keys by `d` comp seconds, snapped to the comp's frames in comp time (keys
+/// of time-stretched layers move with the pointer, not by the layer-time distance). Keys of
+/// locked layers stay. A key landing on another key of its property replaces it.
+pub(crate) fn shift_keys(s: &mut Session, label: &str, merge: Option<&str>, d: Tick) -> Result<Value> {
+    let cid = s.active_comp_id().ok_or(EngineError::NoComp)?;
+    // A drag (steps with one merge key) starts again from the keys before it each step.
+    let gesture = merge.is_some_and(|m| s.history.merge_key.as_deref() == Some(m)) && s.key_move.as_ref().map(|g| g.merge.as_str()) == merge;
+    let (from, total, base) = match (&s.key_move, s.history.undo.last()) {
+        (Some(g), Some((_, base))) if gesture => (g.from.clone(), g.total + d, Some(base.clone())),
+        _ => (s.state.selected_keys.clone(), d, None),
+    };
+    s.key_move = merge.map(|m| crate::KeyMove { merge: m.to_string(), from: from.clone(), total });
+    s.edit(label, merge, |proj, st| {
+        if let Some(b) = base {
+            *proj = (*b).clone();
+        }
+        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        let fr = comp.frame_rate;
+        let mut groups: std::collections::BTreeMap<(LayerId, Uid), Vec<Tick>> = Default::default();
+        for k in &from {
+            groups.entry((k.layer, k.prop)).or_default().push(k.time);
+        }
+        let mut sel = vec![];
+        for ((lid, uid), times) in groups {
+            let Some(l) = comp.layer_mut(lid) else { continue };
+            let to = |t: Tick| l.layer_time(fr.snap_nearest(l.comp_time(t) + total));
+            let moves: Vec<(Tick, Tick)> = times.iter().map(|t| (*t, to(*t))).collect();
+            if l.switches.locked {
+                sel.extend(times.iter().map(|t| KeyRef { layer: lid, prop: uid, time: *t }));
+                continue;
+            }
+            let Some(pr) = l.props.find_mut(uid) else { continue };
+            // Take the moving keys out, then put them back at their new times.
+            let mut moved = vec![];
+            for (old, new) in &moves {
+                if let Some(i) = key_at(&pr.keys, *old) {
+                    let mut k = pr.keys.remove(i);
+                    k.time = *new;
+                    moved.push(k);
+                }
+            }
+            for k in moved {
+                sel.push(KeyRef { layer: lid, prop: uid, time: k.time });
+                match pr.keys.binary_search_by(|x| x.time.cmp(&k.time)) {
+                    Ok(j) => pr.keys[j] = k,
+                    Err(j) => pr.keys.insert(j, k),
+                }
+            }
+            // Roving keys follow their neighbours: keep the selection on them.
+            let before: Vec<Tick> = pr.keys.iter().map(|k| k.time).collect();
+            if effectcraft_keyframe::retime_roving(&mut pr.keys, pr.spatial) {
+                for r in sel.iter_mut().filter(|r| r.layer == lid && r.prop == uid) {
+                    if let Some(i) = before.iter().position(|t| *t == r.time) {
+                        r.time = pr.keys[i].time;
+                    }
+                }
+            }
+        }
+        st.selected_keys = sel;
+        Ok(json!(st.selected_keys.len()))
+    })
+}
+
 fn move_keys(s: &mut Session, p: &Value) -> Result<Value> {
     let d = Tick::from_seconds_f64(f_p(p, "delta").ok_or_else(|| bad("keys.move", "missing `delta` (seconds)"))?);
-    let fr = s.active_comp().map(|c| c.frame_rate);
-    edit_keys(s, "Move Keyframes", merge_p(p), move |_, _, t| {
-        let nt = *t + d;
-        *t = fr.map(|r| r.snap_nearest(nt)).unwrap_or(nt);
-        true
-    })
+    shift_keys(s, "Move Keyframes", merge_p(p), d)
 }
 
 fn delete_keys(s: &mut Session, _: &Value) -> Result<Value> {
@@ -543,7 +613,14 @@ fn interpolation(s: &mut Session, p: &Value) -> Result<Value> {
 fn toggle_hold(s: &mut Session, _: &Value) -> Result<Value> {
     edit_keys(s, "Toggle Hold Keyframe", None, |keys, i, _| {
         let k = &mut keys[i];
-        k.out_interp = if k.out_interp == Interp::Hold { Interp::Linear } else { Interp::Hold };
+        // Off again: back to Bezier when the key eases (its other side, auto / continuous, or
+        // an outgoing ease), else Linear.
+        let bezier = k.auto_bezier || k.continuous || k.in_interp == Interp::Bezier || !k.out_ease.is_empty();
+        k.out_interp = match k.out_interp {
+            Interp::Hold if bezier => Interp::Bezier,
+            Interp::Hold => Interp::Linear,
+            _ => Interp::Hold,
+        };
         false
     })
 }
@@ -667,7 +744,15 @@ pub fn specs() -> Vec<CommandSpec> {
             has_layers,
             convert_expr_to_keys
         ),
-        cmd!("keys.select", "Select Keyframes", [], None, "{keys: [{layer, prop: uid | path (or `path`), time (layer s)}], add?}", has_comp, select_keys),
+        cmd!(
+            "keys.select",
+            "Select Keyframes",
+            [],
+            None,
+            "{keys: [{layer, prop: uid | path (or `path`), time (layer s)}], add?, toggle?: bool (Shift+click: in or out of the selection)}",
+            has_comp,
+            select_keys
+        ),
         cmd!("keys.move", "Move Keyframes", [], None, "{delta (s), merge?}", has_keys, move_keys),
         cmd!("keys.delete", "Delete Keyframes", [], None, "{}", has_keys, delete_keys),
         cmd!("keys.easyEase", "Easy Ease", ["Animation", "Keyframe Assistant"], Some("F9"), "{which?: both|in|out}", has_keys, ease),

crates/engine/src/commands/query.rs

@@ -79,6 +79,7 @@ fn comp_info(s: &mut Session, p: &Value) -> Result<Value> {
     Ok(json!({
         "id": cid.0, "name": name, "width": c.width, "height": c.height, "frameRate": c.frame_rate.as_f64(), "duration": c.duration.seconds(),
         "workArea": [c.work_area.0.seconds(), c.work_area.1.seconds()], "background": c.background,
+        "preserveFrameRate": c.preserve_frame_rate, "preserveResolution": c.preserve_resolution,
         "layers": c.layers.iter().enumerate().map(|(i, l)| layer_json(l, i + 1)).collect::<Vec<_>>(),
     }))
 }

crates/engine/src/commands/scene_detect.rs

@@ -136,7 +136,7 @@ fn apply(s: &mut Session, cid: ItemId, lid: LayerId, mode: Mode, cuts: &[Tick])
         let i = cm.layers.iter().position(|l| l.id == lid).ok_or(EngineError::NoComp)?;
         let mut ids = vec![lid];
         for t in cuts {
-            let cur = cm.layers.iter().position(|l| l.id == *ids.last().expect("piece")).unwrap_or(i);
+            let cur = ids.last().and_then(|last| cm.layers.iter().position(|l| l.id == *last)).unwrap_or(i);
             let l = &mut cm.layers[cur];
             if !(*t > l.in_point && *t < l.out_point) {
                 continue;

crates/engine/src/commands/text_anim.rs

@@ -72,14 +72,11 @@ fn animator_uid(s: &Session, l: &Layer, p: &Value, cmd: &str) -> Result<u64> {
 /// Add the properties of `kind` to an animator's Properties group (skipping ones it has).
 fn add_props(ids: &mut Ids, anim: &mut PropGroup, kind: &str, three_d: bool) -> usize {
     let list = build::text_anim_props(ids, kind, three_d);
-    let props = match anim.sub_mut("properties") {
-        Some(p) => p,
-        None => {
-            let g = ids.group("properties", "Properties");
-            anim.children.push(g.into());
-            anim.sub_mut("properties").expect("just added")
-        }
-    };
+    if anim.sub("properties").is_none() {
+        let g = ids.group("properties", "Properties");
+        anim.children.push(g.into());
+    }
+    let Some(props) = anim.sub_mut("properties") else { return 0 };
     let mut n = 0;
     for pr in list {
         if props.get(&pr.match_id).is_none() {
@@ -161,14 +158,11 @@ pub(crate) fn add_selector(s: &mut Session, p: &Value) -> Result<Value> {
         let mut ids = Ids(&mut next);
         let l = layer_mut(proj, cid, lid)?;
         let anim = l.props.find_group_mut(auid).ok_or_else(|| bad(C, "no such animator"))?;
-        let sels = match anim.sub_mut("selectors") {
-            Some(g) => g,
-            None => {
-                let g = ids.group("selectors", "Selectors");
-                anim.children.insert(0, g.into());
-                anim.sub_mut("selectors").expect("just added")
-            }
-        };
+        if anim.sub("selectors").is_none() {
+            let g = ids.group("selectors", "Selectors");
+            anim.children.insert(0, g.into());
+        }
+        let sels = anim.sub_mut("selectors").ok_or_else(|| bad(C, "the animator has no Selectors group"))?;
         let (m, label) = match kind.as_str() {
             "range" => ("rangeSelector", "Range Selector"),
             "wiggly" => ("wigglySelector", "Wiggly Selector"),

crates/engine/src/commands/text_edit.rs

@@ -455,8 +455,9 @@ pub(crate) fn sanitize(s: &mut Session) {
     match layer_doc(s, e.layer) {
         Some(d) => {
             let n = d.char_len();
-            if e.anchor > n || e.caret > n {
-                let ed = s.state.text_edit.as_mut().expect("checked");
+            if (e.anchor > n || e.caret > n)
+                && let Some(ed) = s.state.text_edit.as_mut()
+            {
                 ed.anchor = ed.anchor.min(n);
                 ed.caret = ed.caret.min(n);
             }

crates/engine/src/commands/time.rs

@@ -71,6 +71,7 @@ fn go(s: &mut Session, p: &Value) -> Result<Value> {
     let t = s.time();
     let to = str_p(p, "to").unwrap_or("start");
     let sel_layer = s.state.selected_layers.first().and_then(|id| comp.layer(*id));
+    let visible = super::visible_p(p);
     let target = match to {
         "start" => Tick::ZERO,
         "end" => comp.duration - comp.frame_duration(),
@@ -78,8 +79,25 @@ fn go(s: &mut Session, p: &Value) -> Result<Value> {
         "workEnd" => comp.work_area.1 - comp.frame_duration(),
         "layerIn" => sel_layer.map(|l| l.in_point).unwrap_or(t),
         "layerOut" => sel_layer.map(|l| l.out_point - comp.frame_duration()).unwrap_or(t),
+        "nextKey" | "prevKey" if visible.is_some() => {
+            // What the Timeline shows: keys of its revealed properties, layer and comp markers
+            // and the work area (After Effects' "visible items").
+            let mut times: Vec<Tick> = comp.markers.iter().map(|m| m.time).collect();
+            times.extend([comp.work_area.0, comp.work_area.1 - comp.frame_duration()]);
+            for l in comp.layers.iter().filter(|l| !(comp.hide_shy && l.switches.shy)) {
+                times.extend(l.markers.iter().map(|m| l.comp_time(m.time)));
+            }
+            for (lid, uid) in visible.iter().flatten() {
+                if let Some(l) = comp.layer(*lid)
+                    && let Some(pr) = l.props.find(*uid)
+                {
+                    times.extend(pr.keys.iter().map(|k| l.comp_time(k.time)));
+                }
+            }
+            step_to(times, t, comp.frame_duration(), to == "nextKey")
+        }
         "nextKey" | "prevKey" => {
-            // Keyframes (of visible/selected layers) and markers, in comp time.
+            // Keyframes (of visible/selected layers), markers and the work area, in comp time.
             let mut times: Vec<Tick> = comp.markers.iter().map(|m| m.time).collect();
             let layers: Vec<_> = if s.state.selected_layers.is_empty() {
                 comp.layers.iter().collect()
@@ -90,6 +108,9 @@ fn go(s: &mut Session, p: &Value) -> Result<Value> {
             let only = p.get("prop").and_then(Value::as_u64);
             if only.is_some() {
                 times.clear();
+            } else {
+                // The work area's start and end too, as in After Effects.
+                times.extend([comp.work_area.0, comp.work_area.1 - comp.frame_duration()]);
             }
             for l in layers {
                 l.props.walk("", &mut |_, pr| {
@@ -104,14 +125,7 @@ fn go(s: &mut Session, p: &Value) -> Result<Value> {
                     times.extend(l.markers.iter().map(|m| l.comp_time(m.time)));
                 }
             }
-            times.sort();
-            times.dedup();
-            let half = comp.frame_duration().0 / 2;
-            if to == "nextKey" {
-                times.into_iter().find(|x| x.0 > t.0 + half).unwrap_or(t)
-            } else {
-                times.into_iter().rev().find(|x| x.0 < t.0 - half).unwrap_or(t)
-            }
+            step_to(times, t, comp.frame_duration(), to == "nextKey")
         }
         _ => return Err(super::bad("time.go", "to: start|end|workStart|workEnd|layerIn|layerOut|nextKey|prevKey")),
     };
@@ -119,6 +133,22 @@ fn go(s: &mut Session, p: &Value) -> Result<Value> {
     Ok(report(s))
 }
 
+/// The nearest time in `times` after (or before) `t`, more than half a frame away; `t` itself
+/// when there is none.
+fn step_to(mut times: Vec<Tick>, t: Tick, frame: Tick, next: bool) -> Tick {
+    times.sort();
+    times.dedup();
+    let half = frame.0 / 2;
+    if next { times.into_iter().find(|x| x.0 > t.0 + half).unwrap_or(t) } else { times.into_iter().rev().find(|x| x.0 < t.0 - half).unwrap_or(t) }
+}
+
+/// `p` with `to` set (J / K pass their other parameters on).
+fn with_to(p: &Value, to: &str) -> Value {
+    let mut p = if p.is_object() { p.clone() } else { json!({}) };
+    p["to"] = json!(to);
+    p
+}
+
 pub fn specs() -> Vec<CommandSpec> {
     vec![
         cmd!("time.set", "Go to Time...", ["View"], Some("Alt+Shift+J"), "{time? (s) | frame? | timecode?}", has_comp, set),
@@ -131,8 +161,27 @@ pub fn specs() -> Vec<CommandSpec> {
         cmd!("time.end", "Go to End", [], Some("End"), "{}", has_comp, |s, _| go(s, &json!({"to": "end"}))),
         cmd!("time.layerIn", "Go to Layer In Point", [], Some("I"), "{}", has_comp, |s, _| go(s, &json!({"to": "layerIn"}))),
         cmd!("time.layerOut", "Go to Layer Out Point", [], Some("O"), "{}", has_comp, |s, _| go(s, &json!({"to": "layerOut"}))),
-        cmd!("time.nextKey", "Go to Next Keyframe or Marker", [], Some("K"), "{}", has_comp, |s, _| go(s, &json!({"to": "nextKey"}))),
-        cmd!("time.previousKey", "Go to Previous Keyframe or Marker", [], Some("J"), "{}", has_comp, |s, _| go(s, &json!({"to": "prevKey"}))),
-        cmd!("time.go", "Go To", [], None, "{to: start|end|workStart|workEnd|layerIn|layerOut|nextKey|prevKey, prop?: uid}", has_comp, go),
+        cmd!(
+            "time.nextKey",
+            "Go to Next Keyframe or Marker",
+            [],
+            Some("K"),
+            "{visible?: [{layer, prop}] (only these properties' keys, as the Timeline shows them)}",
+            has_comp,
+            |s, p| go(s, &with_to(p, "nextKey"))
+        ),
+        cmd!("time.previousKey", "Go to Previous Keyframe or Marker", [], Some("J"), "{visible?: [{layer, prop}]}", has_comp, |s, p| go(
+            s,
+            &with_to(p, "prevKey")
+        )),
+        cmd!(
+            "time.go",
+            "Go To",
+            [],
+            None,
+            "{to: start|end|workStart|workEnd|layerIn|layerOut|nextKey|prevKey, prop?: uid, visible?: [{layer, prop}]}",
+            has_comp,
+            go
+        ),
     ]
 }

crates/engine/src/commands/track.rs

@@ -214,7 +214,7 @@ fn create(s: &mut Session, p: &V, cmd: &str) -> Result<V> {
         let mut ids = Ids(&mut next);
         let g = tracking::tracker(&mut ids, &name, st, &pts);
         let uid = g.uid;
-        l.motion_trackers_mut(&mut ids).children.push(g.into());
+        l.motion_trackers_mut(&mut ids).ok_or_else(|| bad(cmd, "the layer has no Motion Trackers group"))?.children.push(g.into());
         proj.next_id = next;
         state.current_track = Some((lid, uid));
         state.selected_layers = vec![lid];

crates/engine/src/guard.rs

@@ -0,0 +1,65 @@
+//! The last-resort guard: a panic that escapes a command (a bug, never an expected error) is
+//! turned into an [`EngineError`] instead of taking the app, and the user's open project, down
+//! with it. Edits work on a copy of the project (see [`crate::Session::edit`]), so an edit that
+//! panics leaves the project as it was. This is a safety net, not a substitute for returning
+//! errors (AGENTS.md, "Never crash").
+
+use crate::{EngineError, Result};
+
+/// Run `f`; a panic inside it becomes an error naming `what`. The panic itself is logged by
+/// the panic hook ([`crate::logging::install_panic_hook`]).
+pub fn guarded<T>(what: &str, f: impl FnOnce() -> Result<T>) -> Result<T> {
+    match std::panic::catch_unwind(std::panic::AssertUnwindSafe(f)) {
+        Ok(r) => r,
+        Err(payload) => {
+            let msg = payload
+                .downcast_ref::<&str>()
+                .map(|s| s.to_string())
+                .or_else(|| payload.downcast_ref::<String>().cloned())
+                .unwrap_or_else(|| "unknown error".into());
+            log::error!("{what} panicked: {msg}");
+            Err(EngineError::Other(format!("{what} failed with an internal error ({msg}); it was stopped and your project is still open")))
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn a_panic_becomes_an_error() {
+        let r: Result<()> = guarded("command `test.panic`", || panic!("boom"));
+        let e = r.unwrap_err().to_string();
+        assert!(e.contains("test.panic") && e.contains("boom"), "{e}");
+        let r: Result<u8> = guarded("x", || {
+            let v: Vec<u8> = vec![];
+            Ok(v[3])
+        });
+        assert!(r.is_err());
+        assert_eq!(guarded("ok", || Ok(7)).unwrap(), 7);
+        assert!(matches!(guarded::<()>("err", || Err(EngineError::NoComp)), Err(EngineError::NoComp)));
+    }
+
+    #[test]
+    fn the_session_survives_a_panicking_edit() {
+        let mut s = crate::Session::new();
+        let before = s.project.clone();
+        let r: Result<()> = guarded("command `test.edit`", || {
+            s.edit("Broken", None, |p, _| {
+                p.next_id += 1;
+                panic!("bug in the middle of an edit")
+            })
+        });
+        assert!(r.is_err());
+        assert!(std::sync::Arc::ptr_eq(&before, &s.project), "the project is untouched");
+        // Later edits still work.
+        let next = s.project.next_id;
+        s.edit("Fine", None, |p, _| {
+            p.next_id += 1;
+            Ok(())
+        })
+        .unwrap();
+        assert_eq!(s.project.next_id, next + 1);
+    }
+}

crates/engine/src/lib.rs

@@ -8,12 +8,15 @@
 //! The project is an `Arc<Project>` edited copy-on-write; undo keeps whole-project snapshots
 //! (compositions are `Arc`s, so untouched comps are shared).
 
+#![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 footage_check;
+pub mod guard;
 pub mod history;
 pub mod jobs;
 pub mod learn;
@@ -131,6 +134,17 @@ pub struct KeyRef {
     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 {
@@ -370,6 +384,10 @@ pub struct Session {
     /// The last physical-memory reading (Settings ▸ Memory & CPU budgets); `None` = unknown
     /// (headless sessions don't query it, see [`Session::memory_tick`]).
     pub sys_memory: Option<sysinfo::SysMemory>,
+    /// The keyframe drag in progress (`keys.move` with a merge key).
+    pub key_move: Option<KeyMove>,
+    /// Reads the system's memory in the background for [`Session::memory_tick`].
+    pub memory_watch: sysinfo::MemoryWatch,
     /// 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
@@ -462,6 +480,8 @@ impl Default for Session {
             plugin_loader: None,
             script_ui: scriptui::ScriptUi::default(),
             sys_memory: None,
+            key_move: None,
+            memory_watch: Default::default(),
             applied_nested_switches: None,
             offload: None,
             offloaded: vec![],
@@ -495,7 +515,8 @@ impl Session {
                 return Err(EngineError::Disabled(id.to_string(), why));
             }
         }
-        let r = (spec.run)(self, &params)?;
+        // 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));
@@ -631,6 +652,13 @@ impl Session {
         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?)
     }
@@ -926,6 +954,8 @@ mod tests_fidelity;
 #[cfg(test)]
 mod tests_frame_export;
 #[cfg(test)]
+mod tests_keylight;
+#[cfg(test)]
 mod tests_lottie;
 #[cfg(test)]
 mod tests_m137;
@@ -940,6 +970,8 @@ 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;

crates/engine/src/links.rs

@@ -12,7 +12,7 @@ pub const ISSUES: &str = "https://github.com/storytold/effectcraft/issues";
 /// Sibling apps of the ArtCraft family: (name, what it is, GitHub repo, app page).
 pub const SIBLINGS: &[(&str, &str)] = &[
     ("PhotoCraft", "photocraft"),
-    ("DrawCraft", "drawcraft"),
+    ("VectorCraft", "vectorcraft"),
     ("FilmCraft", "filmcraft"),
     ("LightCraft", "lightcraft"),
     ("PrintCraft", "printcraft"),

crates/engine/src/logging.rs

@@ -62,6 +62,16 @@ pub fn install() {
     }
 }
 
+/// Log every panic (message and location) through the logger, then run the previous hook
+/// (which prints it). Panics in commands are then caught by [`crate::guard::guarded`].
+pub fn install_panic_hook() {
+    let previous = std::panic::take_hook();
+    std::panic::set_hook(Box::new(move |info| {
+        log::error!("panic: {info}");
+        previous(info);
+    }));
+}
+
 /// The log file inside `config_dir` (the settings folder), or the temporary folder.
 pub fn log_path(config_dir: Option<&Path>) -> PathBuf {
     config_dir.map(Path::to_path_buf).unwrap_or_else(std::env::temp_dir).join("Logs").join("EffectCraft Log.txt")

crates/engine/src/mask_track.rs

@@ -439,8 +439,7 @@ impl Session {
             }
             self.bump();
         }
-        if finished {
-            let mut job = self.mask_job.take().expect("job");
+        if finished && let Some(mut job) = self.mask_job.take() {
             if let Some(t) = job.thread.take() {
                 let _ = t.join();
             }

crates/engine/src/menus.rs

@@ -196,7 +196,13 @@ pub fn top_level() -> Vec<&'static str> {
 /// The menu bar for this platform.
 pub fn menu_bar() -> &'static [MenuNode] {
     static BAR: OnceLock<Vec<MenuNode>> = OnceLock::new();
-    BAR.get_or_init(|| parse(TREE, cfg!(target_os = "macos")).expect("menu tree parses"))
+    BAR.get_or_init(|| {
+        // The tree is a constant (a test parses it on every platform); never panic over it.
+        parse(TREE, cfg!(target_os = "macos")).unwrap_or_else(|e| {
+            log::error!("menu tree: {e}");
+            Vec::new()
+        })
+    })
 }
 
 /// Every entry with its submenu path (`["Layer", "Blending Mode"]`), depth first.
@@ -344,6 +350,15 @@ pub fn checked(s: &Session, command: &str, params: &Value) -> Option<bool> {
     }
 }
 
+/// Labels that name the platform's own tools: "Reveal in Finder" is "Reveal in Explorer" on
+/// Windows (as in After Effects) and "Reveal in File Manager" elsewhere.
+fn platform_label(label: &str, mac: bool) -> String {
+    match label.strip_prefix("Reveal in Finder") {
+        Some(rest) if !mac => format!("Reveal in {}{rest}", if cfg!(target_os = "windows") { "Explorer" } else { "File Manager" }),
+        _ => label.to_string(),
+    }
+}
+
 /// Parse the tree text. `mac` selects `[mac]` / `[!mac]` lines.
 pub fn parse(text: &str, mac: bool) -> Result<Vec<MenuNode>, String> {
     struct Line<'a> {
@@ -378,7 +393,7 @@ pub fn parse(text: &str, mac: bool) -> Result<Vec<MenuNode>, String> {
         }
         lines.push(Line { depth, body });
     }
-    fn build(lines: &[Line], i: &mut usize, depth: usize) -> Result<Vec<MenuNode>, String> {
+    fn build(lines: &[Line], i: &mut usize, depth: usize, mac: bool) -> Result<Vec<MenuNode>, String> {
         let mut out = vec![];
         while *i < lines.len() {
             let l = &lines[*i];
@@ -402,7 +417,7 @@ pub fn parse(text: &str, mac: bool) -> Result<Vec<MenuNode>, String> {
                 continue;
             }
             let mut parts = l.body.split(" | ");
-            let label = parts.next().unwrap_or_default().trim().to_string();
+            let label = platform_label(parts.next().unwrap_or_default().trim(), mac);
             match parts.next() {
                 Some(cmd) => {
                     let cmd = cmd.trim();
@@ -416,7 +431,7 @@ pub fn parse(text: &str, mac: bool) -> Result<Vec<MenuNode>, String> {
                     out.push(MenuNode::Item(MenuEntry { label, command, params, shortcut }));
                 }
                 None => {
-                    let children = build(lines, i, depth + 1)?;
+                    let children = build(lines, i, depth + 1, mac)?;
                     if children.is_empty() {
                         return Err(format!("`{label}` has neither a command nor children"));
                     }
@@ -427,7 +442,7 @@ pub fn parse(text: &str, mac: bool) -> Result<Vec<MenuNode>, String> {
         Ok(out)
     }
     let mut i = 0;
-    build(&lines, &mut i, 0)
+    build(&lines, &mut i, 0, mac)
 }
 
 /// Effect ▸ category submenus from the effect registry.
@@ -744,8 +759,6 @@ Layer
     RotoBezier | path.rotoBezier
     Closed | mask.setClosed
     Convert To Bezier Path | path.convertToBezier
-    Group Shapes | path.groupShapes
-    Ungroup Shapes | path.ungroupShapes
     Set First Vertex | path.setFirstVertex
     Free Transform Points | path.freeTransform
   Quality
@@ -782,7 +795,7 @@ Layer
     ---
     Flip Horizontal | layer.transform {"op":"flipH"}
     Flip Vertical | layer.transform {"op":"flipV"}
-    Center In View | layer.transform {"op":"center"}
+    Center In View | layer.transform {"op":"center"} | Cmd+Home
     Center Anchor Point in Layer Content | layer.centerAnchor
     Fit to Comp | layer.transform {"op":"fit"} | Cmd+Alt+F
     Fit to Comp Width | layer.transform {"op":"fitWidth"} | Cmd+Alt+Shift+H
@@ -883,6 +896,8 @@ Layer
     Color Overlay | layer.style.colorOverlay
     Gradient Overlay | layer.style.gradientOverlay
     Stroke | layer.style.stroke
+  Group Shapes | path.groupShapes
+  Ungroup Shapes | path.ungroupShapes
   ---
   Arrange
     Bring Layer to Front | layer.arrange {"to":"front"} | Cmd+Shift+]
@@ -1151,6 +1166,7 @@ Window
   Effects & Presets | window.panel {"panel":"effectsPresets"} | Cmd+5
   Essential Graphics | window.panel {"panel":"essentialGraphics"}
   Info | window.panel {"panel":"info"} | Cmd+2
+  Learn | help.inAppTutorials
   Lumetri Scopes | window.panel {"panel":"lumetriScopes"}
   Mask Interpolation | window.panel {"panel":"maskInterpolation"}
   Media Browser | window.panel {"panel":"mediaBrowser"}
@@ -1169,7 +1185,7 @@ Window
   ---
   Composition | window.panel {"panel":"composition"}
   Effect Controls | window.panel {"panel":"effectControls"} | F3
-  Flowchart | window.panel {"panel":"flowchart"}
+  Flowchart | window.panel {"panel":"flowchart"} | Cmd+F11
   Footage | window.panel {"panel":"footage"}
   Layer | window.panel {"panel":"layer"}
   Project | window.panel {"panel":"project"} | Cmd+0

crates/engine/src/menus/tests.rs

@@ -155,3 +155,27 @@ fn parse_rejects_bad_trees() {
     assert!(parse("File\n   Odd | file.save\n", true).is_err());
     assert!(parse("File\n  Bad | file.save {nope}\n", true).is_err());
 }
+
+#[test]
+fn m3_13_entries_follow_after_effects() {
+    let find = |mac: bool, path: &[&str], label: &str| platform_entries(mac).into_iter().find(|(p, e)| p == path && e.label == label).map(|(_, e)| e);
+    // Group / Ungroup Shapes sit in the Layer menu itself.
+    for mac in [true, false] {
+        assert_eq!(find(mac, &["Layer"], "Group Shapes").unwrap().shortcut.as_deref(), Some("Cmd+G"));
+        assert_eq!(find(mac, &["Layer"], "Ungroup Shapes").unwrap().shortcut.as_deref(), Some("Cmd+Shift+G"));
+        assert!(find(mac, &["Layer", "Mask and Shape Path"], "Group Shapes").is_none());
+        // Composition Flowchart Ctrl+Shift+F11, Window ▸ Flowchart Ctrl+F11; Window ▸ Learn.
+        assert_eq!(find(mac, &["Composition"], "Composition Flowchart").unwrap().shortcut.as_deref(), Some("Cmd+Shift+F11"));
+        assert_eq!(find(mac, &["Window"], "Flowchart").unwrap().shortcut.as_deref(), Some("Cmd+F11"));
+        assert_eq!(find(mac, &["Window"], "Learn").unwrap().command, "help.inAppTutorials");
+        assert_eq!(find(mac, &["Layer", "Transform"], "Center In View").unwrap().shortcut.as_deref(), Some("Cmd+Home"));
+    }
+    // "Reveal in Finder" names the platform's file browser.
+    assert!(find(true, &["File"], "Reveal in Finder").is_some());
+    let other = if cfg!(target_os = "windows") { "Reveal in Explorer" } else { "Reveal in File Manager" };
+    for path in [&["File"][..], &["Layer"], &["Layer", "Reveal"]] {
+        assert!(find(false, path, other).is_some(), "{path:?}");
+        assert!(find(false, path, "Reveal in Finder").is_none(), "{path:?}");
+    }
+    assert_eq!(platform_label("Reveal Layer Source in Project", false), "Reveal Layer Source in Project");
+}

crates/engine/src/perf.rs

@@ -3,6 +3,10 @@
 //! frame). The UI-side numbers (first UI frame, timeline and Project panel draw) live in
 //! `effectcraft-ui-egui`'s `bench` module. See `docs/architecture.md` ▸ Performance.
 
+// A benchmark harness (`effectcraft-cli bench --ops`, tests): a failed step should fail loudly,
+// as in tests and benches (AGENTS.md, "Never crash"). Nothing here runs in the app.
+#![allow(clippy::expect_used)]
+
 use std::sync::Arc;
 
 use effectcraft_keyframe::Value as KValue;

crates/engine/src/render_queue.rs

@@ -513,8 +513,8 @@ impl Session {
                         off.cancel(r.id);
                     }
                     self.drain_remote_render();
-                    let j = self.render_job.as_ref().expect("job");
-                    let r = j.remote.as_ref().expect("remote");
+                    let Some(j) = self.render_job.as_ref() else { return true };
+                    let Some(r) = j.remote.as_ref() else { return true };
                     let finished: Vec<u64> =
                         lock(&j.shared.updates).iter().filter_map(|u| if let ItemUpdate::Finished { id, .. } = u { Some(*id) } else { None }).collect();
                     for id in &r.ids {
@@ -570,8 +570,7 @@ impl Session {
             }
             self.bump();
         }
-        if finished {
-            let mut job = self.render_job.take().expect("job");
+        if finished && let Some(mut job) = self.render_job.take() {
             if let Some(t) = job.thread.take() {
                 let _ = t.join();
             }

crates/engine/src/roto.rs

@@ -587,7 +587,7 @@ impl Session {
         if !job.is_finished() {
             return false;
         }
-        let mut job = self.roto_job.take().expect("job");
+        let Some(mut job) = self.roto_job.take() else { return false };
         if let Some(t) = job.thread.take() {
             let _ = t.join();
         }

crates/engine/src/session_settings.rs

@@ -75,11 +75,13 @@ impl Session {
         self.footage.set_cache_budget(b.media);
     }
 
-    /// Re-read the system's memory (desktop frontends call this every few seconds) and re-apply
-    /// the cache budgets when the reading changes them. Returns the effective budgets.
+    /// 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.
     pub fn memory_tick(&mut self) -> crate::prefs::CacheBudgets {
         let before = self.prefs.cache_budgets(self.sys_memory);
-        self.sys_memory = crate::sysinfo::memory().or(self.sys_memory);
+        self.sys_memory = self.memory_watch.latest().or(self.sys_memory);
+        self.memory_watch.poll();
         let after = self.prefs.cache_budgets(self.sys_memory);
         if after != before {
             self.apply_cache_budgets();

crates/engine/src/sysinfo.rs

@@ -4,7 +4,11 @@
 //! 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.
+//! 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.
+
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex, PoisonError};
 
 use serde::Serialize;
 
@@ -23,10 +27,51 @@ 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>>>,
+    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) {
+        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);
+            }
+            busy.store(false, Ordering::Release);
+        };
+        #[cfg(not(target_arch = "wasm32"))]
+        if std::thread::Builder::new().name("ec-memory".into()).spawn(read).is_err() {
+            self.busy.store(false, Ordering::Release);
+        }
+        #[cfg(target_arch = "wasm32")]
+        read();
+    }
+
+    /// The last reading (`None` until one finished).
+    pub fn latest(&self) -> Option<SysMemory> {
+        *self.latest.lock().unwrap_or_else(PoisonError::into_inner)
+    }
+}
+
 #[cfg(not(target_arch = "wasm32"))]
 #[allow(dead_code)]
 fn run(cmd: &str, args: &[&str]) -> Option<String> {
-    let out = std::process::Command::new(cmd).args(args).output().ok()?;
+    let mut c = std::process::Command::new(cmd);
+    c.args(args);
+    // 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
+    let out = c.output().ok()?;
     out.status.success().then(|| String::from_utf8_lossy(&out.stdout).to_string())
 }
 

crates/engine/src/tests.rs

@@ -301,6 +301,17 @@ fn comp_settings_anchor_start_timecode_renderer() {
     assert_eq!(c.renderer, crate::project::Renderer::Advanced3D);
 }
 
+#[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();

crates/engine/src/tests_effects.rs

@@ -185,7 +185,7 @@ fn opening_an_old_project_upgrades_effect_instances() {
     {
         let comp = std::sync::Arc::make_mut(match &mut old.items.get_mut(&cid).unwrap().kind {
             effectcraft_project::ItemKind::Comp(c) => c,
-            _ => unreachable!(),
+            _ => panic!("not a composition"),
         });
         let l = comp.layers.iter_mut().find(|l| l.id == LayerId(a)).unwrap();
         for n in &mut l.props.sub_mut("effects").unwrap().children {

crates/engine/src/tests_history.rs

@@ -175,3 +175,18 @@ fn modified_mark_follows_undo_and_no_op_edits_record_nothing() {
     assert!(!s.is_dirty(), "rolled back");
     let _ = std::fs::remove_file(path);
 }
+
+#[test]
+fn a_session_restored_with_unsaved_changes_stays_modified() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "H", "width": 64, "height": 64, "duration": 2})).unwrap();
+    let p = (*s.project).clone();
+    // The web app reopens the last visit's project, which had unsaved changes.
+    s.replace_project(p, None);
+    assert!(!s.is_dirty());
+    s.mark_unsaved();
+    assert!(s.is_dirty());
+    solid(&mut s, "A");
+    s.execute("edit.undo", json!({})).unwrap();
+    assert!(s.is_dirty(), "undo doesn't reach a saved state");
+}

crates/engine/src/tests_keylight.rs

@@ -0,0 +1,135 @@
+//! Key Light end to end: a green-screen plate (uneven screen, a subject with green spill and a
+//! soft edge) keyed through the commands an agent uses: `effect.apply` by its After Effects name,
+//! `effect.pickColor` on the screen (the effect's input, as the eyedropper does) and a render.
+
+use std::sync::Arc;
+
+use effectcraft_project::{Footage, FootageKind, ItemId};
+use effectcraft_raster::Image;
+use effectcraft_time::{FrameRate, Tick};
+use serde_json::json;
+
+use crate::Session;
+use crate::render::{FootageSource, RenderOpts};
+
+const W: u32 = 96;
+const H: u32 = 64;
+const SKIN: [f32; 3] = [0.86, 0.62, 0.52];
+
+/// The plate's straight colour and alpha (opaque everywhere) at a pixel.
+fn plate(x: u32, y: u32) -> [f32; 3] {
+    // Screen: a slightly uneven, noisy green.
+    let noise = (((x * 7919 + y * 104_729) % 97) as f32 / 97.0 - 0.5) * 0.02;
+    let screen = [0.18 + noise, 0.66 + (x as f32 / W as f32 - 0.5) * 0.04 + noise, 0.30 - noise];
+    let r = ((x as f32 + 0.5 - 48.0).powi(2) + (y as f32 + 0.5 - 32.0).powi(2)).sqrt();
+    // Subject: skin, with green spill in its outer 3 px and a 3 px soft edge.
+    let mut subject = SKIN;
+    if r > 13.0 {
+        subject[1] += 0.12;
+    }
+    let a = ((19.0 - r) / 3.0).clamp(0.0, 1.0);
+    [0, 1, 2].map(|i| subject[i] * a + screen[i] * (1.0 - a))
+}
+
+struct Plate;
+
+impl FootageSource for Plate {
+    fn frame(&self, _: ItemId, _: &Footage, _: Tick) -> Option<Arc<Image>> {
+        let mut img = Image::new(W, H);
+        for y in 0..H {
+            for x in 0..W {
+                let c = plate(x, y);
+                img.set(x, y, [c[0], c[1], c[2], 1.0]);
+            }
+        }
+        Some(Arc::new(img))
+    }
+}
+
+struct Probe;
+impl crate::Importer for Probe {
+    fn probe(&self, path: &str) -> Result<Footage, String> {
+        Ok(Footage {
+            path: path.into(),
+            kind: FootageKind::Still,
+            width: W,
+            height: H,
+            has_video: true,
+            frame_rate: FrameRate::from_f64(24.0),
+            duration: Tick::ZERO,
+            ..Default::default()
+        })
+    }
+}
+
+fn keyed() -> (Session, ItemId) {
+    let mut s = Session { footage: Arc::new(Plate), importer: Some(Arc::new(Probe)), ..Default::default() };
+    let item = s.execute("file.import", json!({"paths": ["/plates/greenscreen.png"]})).unwrap()["items"][0].as_u64().unwrap();
+    s.execute("comp.new", json!({"name": "Key", "width": W, "height": H, "frameRate": 24, "duration": 1})).unwrap();
+    let c = s.active_comp_id().unwrap();
+    s.execute("layer.addItem", json!({"item": item})).unwrap();
+    // After Effects' name finds it; MCP's add_effect / list_effects go through the same lookup.
+    let r = s.execute_checked("effect.apply", json!({"effect": "Keylight (1.2)"})).unwrap();
+    assert_eq!(r["effect"], "ec.keying.keylight");
+    (s, c)
+}
+
+#[test]
+fn key_light_removes_a_green_screen() {
+    let (mut s, c) = keyed();
+    let steps = s.history.undo.len();
+    // The default screen colour (pure green) already keys the screen, so the shown frame is
+    // transparent there; the eyedropper samples the effect's input instead.
+    let picked = s.execute_checked("effect.pickColor", json!({"effect": 1, "param": "screenColour", "x": 6, "y": 6, "average": true})).unwrap();
+    let col: Vec<f64> = picked["color"].as_array().unwrap().iter().map(|v| v.as_f64().unwrap()).collect();
+    let want = plate(6, 6);
+    assert!((0..3).all(|i| (col[i] - want[i] as f64).abs() < 0.02), "{col:?} vs {want:?}");
+    let tree = s.execute("layer.tree", json!({})).unwrap().to_string();
+    assert!(tree.contains("Screen Colour"), "{tree}");
+    // One undo step.
+    assert_eq!(s.history.undo.len(), steps + 1);
+    // Clean the matte as one does in Screen Matte view: Clip Black for the uneven screen, Clip
+    // White for the spill's partial transparency.
+    for (path, v) in [("effects/#1/screenMatte/clipBlack", 10), ("effects/#1/screenMatte/clipWhite", 85)] {
+        s.execute_checked("prop.set", json!({"path": path, "value": v})).unwrap();
+    }
+
+    let img = s.render(c, Tick::ZERO, RenderOpts::default());
+    let px = |x, y| img.get(x, y);
+    // The whole screen goes (corners, both ends of the gradient, noise).
+    for (x, y) in [(1, 1), (94, 1), (1, 62), (94, 62), (20, 32), (76, 32)] {
+        assert!(px(x, y)[3] < 0.03, "screen at {x},{y}: {:?}", px(x, y));
+    }
+    // The subject stays, with its colour.
+    let fg = px(48, 32);
+    assert!(fg[3] > 0.99 && (0..3).all(|i| (fg[i] - SKIN[i]).abs() < 0.02), "{fg:?}");
+    // Spill on the subject's edge is suppressed: no green cast left.
+    let sp = px(48, 32 - 14);
+    assert!(sp[3] > 0.99 && sp[1] <= 0.5 * (sp[0] + sp[2]) + 0.01, "spill {sp:?}");
+    // The soft edge keeps partial alpha, and its recovered colour has no green fringe.
+    let e = px(48, 32 - 18);
+    assert!(e[3] > 0.15 && e[3] < 0.85, "edge {e:?}");
+    let a = e[3];
+    assert!(e[1] / a <= 0.5 * (e[0] + e[2]) / a + 0.02, "edge fringe {e:?}");
+}
+
+#[test]
+fn pick_color_rejects_bad_targets_and_screen_matte_view_shows_the_key() {
+    let (mut s, c) = keyed();
+    // Not a colour parameter / outside the layer.
+    assert!(s.execute_checked("effect.pickColor", json!({"effect": 1, "param": "screenGain", "x": 6, "y": 6})).is_err());
+    assert!(s.execute_checked("effect.pickColor", json!({"effect": 1, "param": "screenColour", "x": -50, "y": 6})).is_err());
+    assert!(s.execute_checked("effect.pickColor", json!({"effect": 1, "param": "screenColour", "x": 1e300, "y": -1e300, "average": true})).is_err());
+    assert!(s.execute_checked("effect.pickColor", json!({"effect": 1, "param": "screenColour"})).is_err());
+    s.execute_checked("effect.pickColor", json!({"effect": 1, "param": "screenColour", "x": 90, "y": 60})).unwrap();
+    // View ▸ Screen Matte: black screen (once Clip Black takes the uneven screen), white subject.
+    for (path, v) in [("effects/#1/view", 4), ("effects/#1/screenMatte/clipBlack", 25)] {
+        s.execute_checked("prop.set", json!({"path": path, "value": v})).unwrap();
+    }
+    let img = s.render(c, Tick::ZERO, RenderOpts::default());
+    assert!(img.get(2, 2)[0] < 0.03 && img.get(48, 32)[0] > 0.97, "{:?} {:?}", img.get(2, 2), img.get(48, 32));
+    // The Effects & Presets / list_effects search finds it by After Effects' name too.
+    let list = s.execute("effect.list", json!({"filter": "Keylight (1.2)"})).unwrap();
+    assert_eq!(list.as_array().map(|a| a.len()), Some(1), "{list}");
+    assert_eq!(list[0]["id"], "ec.keying.keylight");
+}

crates/engine/src/tests_menu_cmds.rs

@@ -263,9 +263,35 @@ fn label_group_purge_and_edit_original() {
     s.execute("layer.select", json!({"layers": [a]})).unwrap();
     s.execute("edit.selectLabelGroup", json!({})).unwrap();
     assert_eq!(s.state.selected_layers.len(), 2);
+    // A footage source that counts purges (the media pool drops its decoded frames).
+    struct Counting(std::sync::atomic::AtomicUsize);
+    impl crate::render::FootageSource for Counting {
+        fn frame(
+            &self,
+            _: effectcraft_project::ItemId,
+            _: &effectcraft_project::Footage,
+            _: effectcraft_time::Tick,
+        ) -> Option<std::sync::Arc<crate::render::Image>> {
+            None
+        }
+        fn purge(&self) {
+            self.0.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
+        }
+    }
+    let src = std::sync::Arc::new(Counting(Default::default()));
+    s.footage = src.clone();
     s.drain_events();
     s.execute("edit.purge", json!({"what": "memory"})).unwrap();
     assert!(s.drain_events().contains(&Event::PurgeCaches));
+    assert_eq!(src.0.load(std::sync::atomic::Ordering::SeqCst), 1, "decoded footage frames are dropped");
+    // The disk cache and the snapshot purge alone: the RAM preview stays.
+    for what in ["disk", "snapshot"] {
+        s.execute("edit.purge", json!({"what": what})).unwrap();
+        assert!(!s.drain_events().contains(&Event::PurgeCaches), "{what}");
+    }
+    assert_eq!(src.0.load(std::sync::atomic::Ordering::SeqCst), 1);
+    s.execute("edit.purge", json!({"what": "3d"})).unwrap();
+    assert!(s.drain_events().contains(&Event::PurgeCaches));
     assert!(!s.is_enabled("edit.editOriginal"));
 }
 
@@ -492,3 +518,539 @@ fn frontend_commands_emit_events_and_stubs_are_disabled() {
         assert!(matches!(s.execute(id, json!({})), Err(EngineError::Disabled(..))), "{id}");
     }
 }
+
+fn solid_of(s: &Session, l: u64) -> (u64, effectcraft_project::Solid, String) {
+    let effectcraft_project::LayerSource::Solid { item } = layer(s, l).source else { panic!("not a solid") };
+    let it = s.project.item(item).unwrap();
+    let ItemKind::Solid(so) = &it.kind else { panic!("not a solid item") };
+    (item.0, so.clone(), it.name.clone())
+}
+
+#[test]
+fn layer_settings_edit_the_solid_or_give_the_layer_its_own() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    s.execute("layer.select", json!({"layers": [a]})).unwrap();
+    let b = s.execute("edit.duplicate", json!({})).unwrap()[0].as_u64().unwrap();
+    assert_eq!(solid_of(&s, a).0, solid_of(&s, b).0, "the duplicate shares the solid");
+    // Nothing given: nothing recorded.
+    let steps = s.history.undo.len();
+    s.execute("layer.settings", json!({"layer": b})).unwrap();
+    assert_eq!(s.history.undo.len(), steps);
+    // Affect all off: the duplicate gets its own solid; the original keeps its colour.
+    let r = s.execute("layer.settings", json!({"layer": b, "color": "#0000ff", "name": "Blue", "affectAll": false})).unwrap();
+    let (bi, bs, bn) = solid_of(&s, b);
+    assert_eq!(r, json!({"layer": b, "solid": bi}));
+    assert_ne!(bi, solid_of(&s, a).0);
+    assert_eq!((bs.color, bn.as_str(), layer(&s, b).name.as_str()), ([0.0, 0.0, 1.0], "Blue", "Blue"));
+    assert_eq!(solid_of(&s, a).1.color, [1.0, 0.0, 0.0]);
+    assert_eq!(
+        s.project.item(effectcraft_project::ItemId(bi)).unwrap().parent,
+        s.project.item(effectcraft_project::ItemId(solid_of(&s, a).0)).unwrap().parent,
+        "same folder"
+    );
+    // Affect all (the default) changes the shared solid in place; size and pixel aspect too.
+    s.execute("layer.select", json!({"layers": [a]})).unwrap();
+    let c = s.execute("edit.duplicate", json!({})).unwrap()[0].as_u64().unwrap();
+    s.execute("layer.settings", json!({"layer": a, "width": 320, "height": 90, "pixelAspect": 2.0})).unwrap();
+    assert_eq!(solid_of(&s, a).0, solid_of(&s, c).0);
+    let so = solid_of(&s, c).1;
+    assert_eq!((so.width, so.height, so.pixel_aspect), (320, 90, 2.0));
+    assert!(s.execute("layer.settings", json!({"layer": a, "pixelAspect": 0})).is_err());
+    // One undo step each.
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(solid_of(&s, a).1.width, 200);
+    // A new solid takes a pixel aspect too.
+    let d = s.execute("layer.newSolid", json!({"color": "#00ff00", "pixelAspect": 0.9091})).unwrap()["layer"].as_u64().unwrap();
+    assert_eq!(solid_of(&s, d).1.pixel_aspect, 0.9091);
+    // Text and shape layers have no settings.
+    assert!(s.is_enabled("layer.settings"));
+    s.execute("layer.newText", json!({"text": "T"})).unwrap();
+    assert!(!s.is_enabled("layer.settings"));
+}
+
+fn order(s: &Session) -> Vec<u64> {
+    s.active_comp().unwrap().layers.iter().map(|l| l.id.0).collect()
+}
+
+fn pos(s: &Session, l: u64) -> [f64; 3] {
+    let ly = layer(s, l);
+    let tr = ly.transform().unwrap();
+    match tr.get("positionX") {
+        Some(x) => [x.value.as_f64(), tr.get("positionY").unwrap().value.as_f64(), tr.get("positionZ").map(|z| z.value.as_f64()).unwrap_or(0.0)],
+        None => tr.get("position").unwrap().value.as_vec3(),
+    }
+}
+
+#[test]
+fn locked_layers_are_not_selected_deleted_or_moved() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    let b = solid(&mut s, "#00ff00");
+    s.execute("layer.setSwitch", json!({"layers": [b], "switch": "lock", "value": true})).unwrap();
+    assert!(layer(&s, b).switches.locked);
+    s.execute("edit.selectAll", json!({})).unwrap();
+    assert_eq!(s.state.selected_layers.iter().map(|l| l.0).collect::<Vec<_>>(), vec![a]);
+    // Ctrl+Up / Down step over it.
+    s.execute("layer.select", json!({"layers": [a]})).unwrap();
+    s.execute("layer.selectPrevious", json!({})).unwrap();
+    assert_eq!(s.state.selected_layers[0].0, a, "nothing above the locked layer to step to");
+    // Deleting, arranging or transforming only the locked layer is refused; with others, it stays.
+    let e = s.execute("edit.clear", json!({"layers": [b]})).unwrap_err().to_string();
+    assert!(e.contains("locked"), "{e}");
+    assert!(s.execute("layer.arrange", json!({"layers": [b], "to": "back"})).is_err());
+    assert!(s.execute("layer.transform", json!({"layers": [b], "op": "center"})).is_err());
+    s.execute("edit.clear", json!({"layers": [a, b]})).unwrap();
+    assert_eq!(order(&s), vec![b]);
+}
+
+#[test]
+fn deleting_a_parent_keeps_its_children_in_place() {
+    let mut s = comp();
+    let parent = solid(&mut s, "#ff0000");
+    s.execute("prop.set", json!({"layer": parent, "path": "transform/position", "value": [300, 200]})).unwrap();
+    s.execute("prop.set", json!({"layer": parent, "path": "transform/rotation", "value": 90})).unwrap();
+    let child = solid(&mut s, "#00ff00");
+    s.execute("prop.set", json!({"layer": child, "path": "transform/position", "value": [210, 160]})).unwrap();
+    s.execute("layer.setParent", json!({"layers": [child], "parent": parent})).unwrap();
+    assert_ne!(pos(&s, child)[..2], [210.0, 160.0], "expressed in the parent's space");
+    s.execute("edit.clear", json!({"layers": [parent]})).unwrap();
+    let p = pos(&s, child);
+    assert!((p[0] - 210.0).abs() < 1e-6 && (p[1] - 160.0).abs() < 1e-6, "{p:?}");
+    assert_eq!(layer(&s, child).parent, None);
+    let r = layer(&s, child).transform().unwrap().get("rotation").unwrap().value.as_f64();
+    assert!(r.abs() < 1e-6, "{r}");
+    // One undo step restores both.
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(layer(&s, child).parent.map(|l| l.0), Some(parent));
+}
+
+#[test]
+fn bring_forward_and_send_backward_move_each_layer_one_step() {
+    let mut s = comp();
+    let ids: Vec<u64> = (0..4).map(|_| solid(&mut s, "#ffffff")).collect();
+    let top = order(&s);
+    assert_eq!(top, ids.iter().rev().copied().collect::<Vec<_>>());
+    let (l0, l1, l2, l3) = (top[0], top[1], top[2], top[3]);
+    // A non-contiguous selection: each moves down one step.
+    s.execute("layer.arrange", json!({"layers": [l0, l2], "to": "backward"})).unwrap();
+    assert_eq!(order(&s), vec![l1, l0, l3, l2]);
+    // Forward again; a layer already at the top stays there.
+    s.execute("layer.arrange", json!({"layers": [l0, l2], "to": "forward"})).unwrap();
+    assert_eq!(order(&s), vec![l0, l1, l2, l3]);
+    s.execute("layer.arrange", json!({"layers": [l0, l2], "to": "forward"})).unwrap();
+    assert_eq!(order(&s), vec![l0, l2, l1, l3]);
+    // Front / Back keep the layers' order.
+    s.execute("layer.arrange", json!({"layers": [l0, l1], "to": "back"})).unwrap();
+    assert_eq!(order(&s), vec![l2, l3, l0, l1]);
+}
+
+#[test]
+fn transform_commands_keep_depth_and_follow_separated_dimensions() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    s.execute("layer.setSwitch", json!({"layers": [a], "switch": "threeD", "value": true})).unwrap();
+    s.execute("prop.set", json!({"layer": a, "path": "transform/position", "value": [10, 20, -300]})).unwrap();
+    s.execute("layer.transform", json!({"layers": [a], "op": "center"})).unwrap();
+    assert_eq!(pos(&s, a), [320.0, 180.0, -300.0]);
+    s.execute("layer.transform", json!({"layers": [a], "op": "fit"})).unwrap();
+    assert_eq!(pos(&s, a), [320.0, 180.0, -300.0]);
+    let b = solid(&mut s, "#00ff00");
+    s.execute("prop.set", json!({"layer": b, "path": "transform/position", "value": [10, 20]})).unwrap();
+    s.execute("prop.separateDimensions", json!({"layer": b, "value": true})).unwrap();
+    s.execute("layer.transform", json!({"layers": [b], "op": "center"})).unwrap();
+    assert_eq!(pos(&s, b)[..2], [320.0, 180.0]);
+    s.execute("layer.transform", json!({"layers": [b], "op": "reset"})).unwrap();
+    assert_eq!(pos(&s, b)[..2], [320.0, 180.0]);
+    // Center Anchor Point moves separated X / Y Position too, so the layer stays put.
+    s.execute("prop.set", json!({"layer": b, "path": "transform/anchor", "value": [0, 0]})).unwrap();
+    s.execute("prop.set", json!({"layer": b, "path": "transform/positionX", "value": 100})).unwrap();
+    s.execute("prop.set", json!({"layer": b, "path": "transform/positionY", "value": 50})).unwrap();
+    s.execute("layer.centerAnchor", json!({"layers": [b]})).unwrap();
+    assert_eq!(pos(&s, b)[..2], [200.0, 100.0], "the 200×100 solid's centre");
+}
+
+#[test]
+fn duplicated_and_pasted_layers_keep_their_links() {
+    let mut s = comp();
+    let parent = solid(&mut s, "#ff0000");
+    let matte = solid(&mut s, "#ffffff");
+    let child = solid(&mut s, "#00ff00");
+    s.execute("layer.setParent", json!({"layers": [child], "parent": parent})).unwrap();
+    s.execute("layer.setTrackMatte", json!({"layer": child, "matte": matte, "kind": "alpha"})).unwrap();
+    let m = layer(&s, child).track_matte.unwrap().layer;
+    assert_eq!(m.0, matte);
+    // Duplicating the child alone keeps the original parent and matte.
+    let d = s.execute("edit.duplicate", json!({"layers": [child]})).unwrap()[0].as_u64().unwrap();
+    assert_eq!((layer(&s, d).parent.map(|l| l.0), layer(&s, d).track_matte.map(|t| t.layer)), (Some(parent), Some(m)));
+    // Duplicating parent and child together: the copy follows the copied parent.
+    let r = s.execute("edit.duplicate", json!({"layers": [parent, child]})).unwrap();
+    let (p2, c2) = (r[0].as_u64().unwrap(), r[1].as_u64().unwrap());
+    assert_eq!(layer(&s, c2).parent.map(|l| l.0), Some(p2));
+    // Copy / paste in the same composition keeps the links; in another one they are dropped.
+    s.execute("layer.select", json!({"layers": [child]})).unwrap();
+    s.execute("edit.copy", json!({})).unwrap();
+    let pasted = s.execute("edit.paste", json!({})).unwrap()[0].as_u64().unwrap();
+    assert_eq!(layer(&s, pasted).parent.map(|l| l.0), Some(parent));
+    assert_eq!(layer(&s, pasted).track_matte.map(|t| t.layer), Some(m));
+    s.execute("comp.new", json!({"name": "Other", "width": 64, "height": 64})).unwrap();
+    let other = s.execute("edit.paste", json!({})).unwrap()[0].as_u64().unwrap();
+    assert_eq!((layer(&s, other).parent, layer(&s, other).track_matte), (None, None));
+}
+
+#[test]
+fn precompose_takes_the_compositions_settings() {
+    let mut s = Session::default();
+    s.execute(
+        "comp.new",
+        json!({"name": "Main", "width": 640, "height": 360, "pixelAspect": 2.0, "shutterAngle": 90, "motionBlurSamples": 8, "renderer": "advanced3D", "background": [0.2, 0.3, 0.4]}),
+    )
+    .unwrap();
+    let a = solid(&mut s, "#ff0000");
+    let r = s.execute("layer.precompose", json!({"layers": [a], "name": "Inner"})).unwrap();
+    let inner = s.project.comp(effectcraft_project::ItemId(r["comp"].as_u64().unwrap())).unwrap();
+    assert_eq!((inner.pixel_aspect, inner.shutter_angle, inner.motion_blur_samples), (2.0, 90.0, 8));
+    assert_eq!((inner.renderer, inner.background), (effectcraft_project::Renderer::Advanced3D, [0.2, 0.3, 0.4]));
+}
+
+#[test]
+fn new_comp_from_selection_is_one_undo_step_with_the_dialog_options() {
+    let mut s = Session::default();
+    let still = |s: &mut Session, name: &str, w: u32, par: f64| {
+        let f = effectcraft_project::Footage {
+            kind: effectcraft_project::FootageKind::Still,
+            width: w,
+            height: 100,
+            pixel_aspect: par,
+            has_video: true,
+            ..Default::default()
+        };
+        std::sync::Arc::make_mut(&mut s.project).add_item(name, effectcraft_color::Label::None, None, ItemKind::Footage(f))
+    };
+    let a = still(&mut s, "a.png", 200, 1.0);
+    let b = still(&mut s, "b.png", 300, 2.0);
+    s.state.project_selection = vec![a, b];
+    // Multiple compositions (the default): one per item, its size and pixel aspect; one undo step.
+    let steps = s.history.undo.len();
+    let r = s.execute("file.newCompFromSelection", json!({"duration": 4})).unwrap();
+    let comps: Vec<u64> = r["comps"].as_array().unwrap().iter().map(|v| v.as_u64().unwrap()).collect();
+    assert_eq!(comps.len(), 2);
+    let cb = s.project.comp(effectcraft_project::ItemId(comps[1])).unwrap();
+    assert_eq!((cb.width, cb.pixel_aspect, cb.duration.seconds()), (300, 2.0, 4.0));
+    assert_eq!(s.history.undo.len(), steps + 1);
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(s.project.comps().count(), 0);
+    // One composition holding both, sized like the second, sequenced with a 1 s overlap, queued.
+    s.state.project_selection = vec![a, b];
+    let r = s
+        .execute(
+            "file.newCompFromSelection",
+            json!({"single": true, "dimensionsFrom": 1, "duration": 3, "sequence": true, "overlap": true, "overlapDuration": 1, "addToRenderQueue": true}),
+        )
+        .unwrap();
+    let c = s.project.comp(effectcraft_project::ItemId(r["comps"][0].as_u64().unwrap())).unwrap();
+    assert_eq!((c.width, c.pixel_aspect, c.duration.seconds()), (300, 2.0, 5.0));
+    let names: Vec<&str> = c.layers.iter().map(|l| l.name.as_str()).collect();
+    assert_eq!(names, ["a.png", "b.png"], "first selected on top");
+    // Stills have no rate: the comp is 29.97 fps and the second layer starts on the frame nearest 2 s.
+    assert_eq!(c.layers[0].in_point.seconds(), 0.0);
+    assert!((c.layers[1].in_point.seconds() - 2.0).abs() < 1.0 / 29.97, "{}", c.layers[1].in_point.seconds());
+    assert_eq!(s.project.render_queue.len(), 1);
+    assert_eq!(s.history.undo.len(), steps + 1);
+    s.execute("edit.undo", json!({})).unwrap();
+    assert!(s.project.render_queue.is_empty() && s.project.comps().count() == 0);
+    s.state.project_selection = vec![a, b];
+    assert!(s.execute("file.newCompFromSelection", json!({"single": true, "dimensionsFrom": 2})).is_err());
+}
+
+#[test]
+fn project_files_keep_their_format_warn_about_newer_versions_and_never_save_unreadable() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    let path = tmp("Safe.ecproj");
+    s.execute("file.saveAs", json!({"path": path})).unwrap();
+    let saved = std::fs::read_to_string(&path).unwrap();
+    assert_eq!(effectcraft_project::saved_by(&saved).as_deref(), Some(effectcraft_project::APP_VERSION));
+    // Save a Copy and Increment and Save keep an XML project XML.
+    let copy = tmp("Copy.ecprojx");
+    s.execute("file.saveCopy", json!({"path": copy})).unwrap();
+    assert!(std::fs::read_to_string(&copy).unwrap().starts_with("<?xml"));
+    s.execute("file.saveAs", json!({"path": tmp("Xml.ecprojx")})).unwrap();
+    let r = s.execute("file.incrementAndSave", json!({})).unwrap();
+    let inc = r["path"].as_str().unwrap().to_string();
+    assert!(inc.ends_with("Xml 2.ecprojx"), "{inc}");
+    assert!(std::fs::read_to_string(&inc).unwrap().starts_with("<?xml"));
+    let r = s.execute("file.open", json!({"path": inc})).unwrap();
+    assert_eq!(r["savedBy"], json!(effectcraft_project::APP_VERSION));
+    // A project from a newer version opens with a warning.
+    let newer = tmp("Newer.ecproj");
+    std::fs::write(&newer, saved.replacen(effectcraft_project::APP_VERSION, "999.0.0", 1)).unwrap();
+    s.drain_events();
+    let r = s.execute("file.open", json!({"path": newer})).unwrap();
+    assert_eq!(r["savedBy"], json!("999.0.0"));
+    let warned = s.drain_events().into_iter().any(|e| matches!(e, Event::Toast { message, .. } if message.contains("newer than this version")));
+    assert!(warned);
+    // A value a project file can't hold: Save fails and the file on disk is left as it was.
+    s.execute("file.open", json!({"path": path})).unwrap();
+    let cid = s.state.active_comp.unwrap();
+    std::sync::Arc::make_mut(&mut s.project)
+        .comp_mut(cid)
+        .unwrap()
+        .layer_mut(effectcraft_project::LayerId(a))
+        .unwrap()
+        .props
+        .prop_mut("transform/opacity")
+        .unwrap()
+        .value = KV::Scalar(f64::NAN);
+    let e = s.execute("file.save", json!({})).unwrap_err().to_string();
+    assert!(e.contains("can't be saved"), "{e}");
+    assert_eq!(std::fs::read_to_string(&path).unwrap(), saved);
+    // Not a project: a clear message.
+    let junk = tmp("Junk.ecproj");
+    std::fs::write(&junk, "{ not json").unwrap();
+    let e = s.execute("file.open", json!({"path": junk})).unwrap_err().to_string();
+    assert!(e.contains("is not a project EffectCraft can open"), "{e}");
+}
+
+#[test]
+fn comp_settings_preserve_frame_rate_and_resolution() {
+    let mut s = comp();
+    let info = s.execute("comp.info", json!({})).unwrap();
+    assert_eq!((info["preserveFrameRate"].clone(), info["preserveResolution"].clone()), (json!(false), json!(false)));
+    s.execute_checked("comp.settings", json!({"preserveFrameRate": true, "preserveResolution": true})).unwrap();
+    let info = s.execute("comp.info", json!({})).unwrap();
+    assert_eq!((info["preserveFrameRate"].clone(), info["preserveResolution"].clone()), (json!(true), json!(true)));
+    // Pre-compose keeps them; one undo step clears them.
+    let a = solid(&mut s, "#ff0000");
+    let r = s.execute("layer.precompose", json!({"layers": [a], "name": "Inner"})).unwrap();
+    let inner = s.project.comp(effectcraft_project::ItemId(r["comp"].as_u64().unwrap())).unwrap();
+    assert!(inner.preserve_frame_rate && inner.preserve_resolution);
+    // Undo Pre-compose and the solid; then one more step undoes the settings.
+    s.execute("edit.undo", json!({})).unwrap();
+    s.execute("edit.undo", json!({})).unwrap();
+    assert!(s.active_comp().unwrap().preserve_frame_rate);
+    s.execute("edit.undo", json!({})).unwrap();
+    assert!(!s.active_comp().unwrap().preserve_frame_rate && !s.active_comp().unwrap().preserve_resolution);
+}
+
+#[test]
+fn new_comp_from_selection_survives_hostile_sequence_numbers() {
+    let mut s = Session::default();
+    let still = |s: &mut Session, name: &str| {
+        let f = effectcraft_project::Footage {
+            kind: effectcraft_project::FootageKind::Still,
+            width: 64,
+            height: 64,
+            pixel_aspect: 1.0,
+            has_video: true,
+            ..Default::default()
+        };
+        std::sync::Arc::make_mut(&mut s.project).add_item(name, effectcraft_color::Label::None, None, ItemKind::Footage(f))
+    };
+    let a = still(&mut s, "a.png");
+    let b = still(&mut s, "b.png");
+    let c = still(&mut s, "c.png");
+    for overlap in [json!(1e30), json!(-5), json!(f64::MAX)] {
+        s.state.project_selection = vec![a, b, c];
+        // A huge overlap overflowed the duration arithmetic (a panic with overflow checks, a
+        // wrapped, too long comp without them).
+        let r = s
+            .execute("file.newCompFromSelection", json!({"single": true, "sequence": true, "overlap": true, "overlapDuration": overlap, "duration": 2}))
+            .unwrap();
+        let c = s.project.comp(effectcraft_project::ItemId(r["comps"][0].as_u64().unwrap())).unwrap();
+        assert!(c.duration.seconds() <= 6.0 && c.duration > effectcraft_time::Tick::ZERO, "{overlap}: {}", c.duration.seconds());
+    }
+    s.state.project_selection = vec![a, b];
+    assert!(s.execute("file.newCompFromSelection", json!({"single": true, "dimensionsFrom": 99})).is_err());
+}
+
+fn key_times(s: &Session, l: u64) -> Vec<f64> {
+    layer(s, l).props.prop("transform/opacity").unwrap().keys.iter().map(|k| (k.time.seconds() * 30.0).round() / 30.0).collect()
+}
+
+fn opacity_keys(s: &mut Session, l: u64, times: &[f64]) {
+    for (i, t) in times.iter().enumerate() {
+        s.execute("prop.addKey", json!({"layer": l, "path": "transform/opacity", "time": t, "value": i as f64 * 10.0})).unwrap();
+    }
+}
+
+#[test]
+fn dragging_a_key_past_another_keeps_it() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    opacity_keys(&mut s, a, &[1.0, 2.0]);
+    s.execute("keys.select", json!({"keys": [{"layer": a, "path": "transform/opacity", "time": 1.0}]})).unwrap();
+    // One drag, frame by frame, from 1 s over the 2 s key to 3 s.
+    for _ in 0..60 {
+        s.execute("keys.move", json!({"delta": 1.0 / 30.0, "merge": "key-drag"})).unwrap();
+    }
+    assert_eq!(key_times(&s, a), vec![2.0, 3.0], "the 2 s key passed over is still there");
+    // Dropped exactly on a key: it replaces it, as in After Effects.
+    s.history.merge_key = None;
+    s.execute("keys.move", json!({"delta": -1.0, "merge": "key-drag-2"})).unwrap();
+    assert_eq!(key_times(&s, a), vec![2.0]);
+    // The whole drag was one undo step.
+    s.execute("edit.undo", json!({})).unwrap();
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(key_times(&s, a), vec![1.0, 2.0]);
+}
+
+#[test]
+fn keys_of_a_stretched_layer_move_with_the_pointer() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    opacity_keys(&mut s, a, &[0.0, 1.0]);
+    s.execute_checked("layer.timeStretch", json!({"layers": [a], "percent": 200})).unwrap();
+    assert_eq!(layer(&s, a).stretch, 200.0);
+    let comp_time = |s: &Session, i: usize| {
+        let l = layer(s, a);
+        l.comp_time(l.props.prop("transform/opacity").unwrap().keys[i].time).seconds()
+    };
+    let before = comp_time(&s, 1);
+    s.execute("keys.select", json!({"keys": [{"layer": a, "path": "transform/opacity", "time": 1.0}]})).unwrap();
+    s.execute("keys.move", json!({"delta": 0.5})).unwrap();
+    assert!((comp_time(&s, 1) - (before + 0.5)).abs() < 1.0 / 30.0, "{} → {}", before, comp_time(&s, 1));
+    s.execute("keys.nudge", json!({"frames": 3})).unwrap();
+    assert!((comp_time(&s, 1) - (before + 0.6)).abs() < 1.0 / 60.0, "three comp frames");
+}
+
+#[test]
+fn key_selection_toggles_and_skips_locked_layers_and_hold_restores_bezier() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    opacity_keys(&mut s, a, &[0.0, 1.0]);
+    let k = |t: f64| json!({"layer": a, "path": "transform/opacity", "time": t});
+    s.execute("keys.select", json!({"keys": [k(0.0)]})).unwrap();
+    s.execute("keys.select", json!({"keys": [k(1.0)], "toggle": true})).unwrap();
+    assert_eq!(s.state.selected_keys.len(), 2);
+    s.execute("keys.select", json!({"keys": [k(0.0)], "toggle": true})).unwrap();
+    assert_eq!(s.state.selected_keys.len(), 1, "toggled out");
+    // Hold off returns an eased key to Bezier.
+    s.execute("keys.easyEase", json!({})).unwrap();
+    s.execute("keys.toggleHold", json!({})).unwrap();
+    s.execute("keys.toggleHold", json!({})).unwrap();
+    let kf = layer(&s, a).props.prop("transform/opacity").unwrap().keys[1].clone();
+    assert_eq!(kf.out_interp, effectcraft_keyframe::Interp::Bezier);
+    // Locked: its keys can't be selected.
+    s.execute("layer.setSwitch", json!({"layers": [a], "switch": "lock", "value": true})).unwrap();
+    s.execute("keys.select", json!({"keys": [k(0.0)]})).unwrap();
+    assert!(s.state.selected_keys.is_empty());
+    s.execute("keys.selectAll", json!({"layers": [a]})).unwrap();
+    assert!(s.state.selected_keys.is_empty());
+}
+
+#[test]
+fn transform_drags_apply_their_whole_offset_to_the_keys_they_started_with() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    opacity_keys(&mut s, a, &[0.0, 1.0, 2.0]);
+    s.execute("keys.selectAll", json!({"layers": [a]})).unwrap();
+    // Squeezed onto one frame on the way, then back: the three keys survive.
+    for k in [0.5, 0.01, 0.0001, 1.0] {
+        s.execute("keys.transform", json!({"timeScale": k, "timeAnchor": 0.0, "merge": "box", "fromStart": true})).unwrap();
+    }
+    assert_eq!(key_times(&s, a), vec![0.0, 1.0, 2.0]);
+    // A slow move in tiny steps still arrives (each step is the whole offset).
+    s.history.merge_key = None;
+    for i in 1..=30 {
+        s.execute("keys.transform", json!({"timeOffset": i as f64 * 0.1 / 30.0, "merge": "move", "fromStart": true})).unwrap();
+    }
+    assert_eq!(key_times(&s, a), vec![0.1, 1.1, 2.1]);
+}
+
+#[test]
+fn select_equal_previous_and_following_keyframes() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    for (t, v) in [(0.0, 20.0), (1.0, 50.0), (2.0, 20.0), (3.0, 70.0)] {
+        s.execute("prop.addKey", json!({"layer": a, "path": "transform/opacity", "time": t, "value": v})).unwrap();
+    }
+    let pick = |s: &mut Session, t: f64| s.execute("keys.select", json!({"keys": [{"layer": a, "path": "transform/opacity", "time": t}]})).unwrap();
+    let times = |s: &Session| {
+        let mut v: Vec<f64> = s.state.selected_keys.iter().map(|k| k.time.seconds()).collect();
+        v.sort_by(f64::total_cmp);
+        v
+    };
+    pick(&mut s, 0.0);
+    s.execute("keys.selectEqual", json!({})).unwrap();
+    assert_eq!(times(&s), vec![0.0, 2.0]);
+    pick(&mut s, 2.0);
+    s.execute("keys.selectPrevious", json!({})).unwrap();
+    assert_eq!(times(&s), vec![0.0, 1.0, 2.0]);
+    pick(&mut s, 1.0);
+    s.execute("keys.selectFollowing", json!({})).unwrap();
+    assert_eq!(times(&s), vec![1.0, 2.0, 3.0]);
+}
+
+#[test]
+fn keys_from_several_layers_paste_in_order_and_paste_reversed_respects_stretch() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    let b = solid(&mut s, "#00ff00");
+    opacity_keys(&mut s, a, &[0.0, 1.0]);
+    s.execute("prop.addKey", json!({"layer": b, "path": "transform/opacity", "time": 0.0, "value": 77})).unwrap();
+    let c = solid(&mut s, "#0000ff");
+    let d = solid(&mut s, "#ffffff");
+    // Copy A's and B's Opacity keys, paste onto C and D: A → C, B → D (in order).
+    s.execute("keys.selectAll", json!({"layers": [a, b]})).unwrap();
+    s.execute("keys.copy", json!({})).unwrap();
+    s.execute("time.set", json!({"time": 2.0})).unwrap();
+    s.execute("layer.select", json!({"layers": [c, d]})).unwrap();
+    s.execute("keys.paste", json!({})).unwrap();
+    assert_eq!(key_times(&s, c), vec![2.0, 3.0], "A's two keys");
+    assert_eq!(key_times(&s, d), vec![2.0], "B's one key");
+    // Paste Reversed onto a layer stretched to 200 %: the reversed keys land 2 s apart there too.
+    let e = solid(&mut s, "#808080");
+    s.execute_checked("layer.timeStretch", json!({"layers": [e], "percent": 200})).unwrap();
+    s.execute("keys.selectAll", json!({"layers": [a]})).unwrap();
+    s.execute("keys.copy", json!({})).unwrap();
+    s.execute("time.set", json!({"time": 0.0})).unwrap();
+    s.execute("layer.select", json!({"layers": [e]})).unwrap();
+    s.execute("edit.pasteReversedKeyframes", json!({})).unwrap();
+    let pr = layer(&s, e).props.prop("transform/opacity").unwrap().clone();
+    let l = layer(&s, e);
+    let ct: Vec<f64> = pr.keys.iter().map(|k| l.comp_time(k.time).seconds()).collect();
+    let vals: Vec<f64> = pr.keys.iter().map(|k| k.value.as_f64()).collect();
+    assert!(ct.len() == 2 && (ct[1] - ct[0] - 1.0).abs() < 1e-6, "keys 1 s apart in comp time: {ct:?}");
+    assert_eq!(vals, vec![10.0, 0.0], "reversed");
+}
+
+#[test]
+fn j_and_k_stop_at_keys_markers_and_the_work_area() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    opacity_keys(&mut s, a, &[2.0]);
+    s.execute("comp.workArea", json!({"start": 1.0, "end": 3.0})).unwrap();
+    s.execute("layer.select", json!({"layers": [a]})).unwrap();
+    let mut stops = vec![];
+    for _ in 0..4 {
+        s.execute("time.nextKey", json!({})).unwrap();
+        stops.push((s.time().seconds() * 30.0).round() / 30.0);
+    }
+    let last = (3.0 * 30.0 - 1.0) / 30.0;
+    assert_eq!(stops, vec![1.0, 2.0, (last * 30.0f64).round() / 30.0, (last * 30.0f64).round() / 30.0]);
+}
+
+#[test]
+fn j_k_and_select_all_use_only_the_properties_the_timeline_shows() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    opacity_keys(&mut s, a, &[1.0]);
+    s.execute("prop.addKey", json!({"layer": a, "path": "transform/rotation", "time": 2.0, "value": 45})).unwrap();
+    let op = layer(&s, a).props.prop("transform/opacity").unwrap().uid;
+    // Only Opacity is revealed: K skips the hidden Rotation key at 2 s, stopping at 1 s and then
+    // at the work area's end.
+    let visible = json!([{"layer": a, "prop": op}]);
+    s.execute_checked("time.nextKey", json!({"visible": visible})).unwrap();
+    assert_eq!(s.time().seconds(), 1.0);
+    s.execute_checked("time.nextKey", json!({"visible": visible})).unwrap();
+    assert!(s.time().seconds() > 3.9, "work area end, not the hidden key: {}", s.time().seconds());
+    // Without `visible` (agents), every key of the layers counts, as before.
+    s.execute("time.set", json!({"time": 1.0})).unwrap();
+    s.execute("time.nextKey", json!({})).unwrap();
+    assert_eq!(s.time().seconds(), 2.0);
+    // Select All Keyframes: the shown properties' keys only.
+    s.execute_checked("keys.selectAll", json!({"visible": visible})).unwrap();
+    assert_eq!(s.state.selected_keys.len(), 1);
+    assert_eq!(s.state.selected_keys[0].prop, op);
+}

crates/engine/src/tests_motion_blur_depth.rs

@@ -0,0 +1,122 @@
+//! Motion blur of collapsed precomps (the precomp layer's own motion; the containing comp's
+//! shutter) and of animated shape content, rendered through the commands.
+
+use effectcraft_raster::Image;
+use effectcraft_time::Tick;
+use serde_json::{Value, json};
+
+use crate::Session;
+use crate::render::RenderOpts;
+
+const W: u32 = 160;
+const H: u32 = 90;
+
+fn id(v: &Value, k: &str) -> u64 {
+    v[k].as_u64().unwrap()
+}
+
+fn render(s: &Session, comp: u64) -> Image {
+    s.render(effectcraft_project::ItemId(comp), Tick::from_seconds_f64(0.5), RenderOpts::default())
+}
+
+/// Pixels with partial alpha (motion-blur smear).
+fn partial(img: &Image) -> usize {
+    img.data.iter().filter(|p| p[3] > 0.05 && p[3] < 0.95).count()
+}
+
+fn max_diff(a: &Image, b: &Image) -> f32 {
+    a.data.iter().zip(&b.data).flat_map(|(p, q)| (0..4).map(move |c| (p[c] - q[c]).abs())).fold(0.0, f32::max)
+}
+
+/// "Main" holding "Pre" (a 20×20 white square in the middle), the precomp layer moving 480 px/s
+/// (20 px a frame at 24 fps) with motion blur on. `inner_move`: the square moves inside Pre too
+/// (with its own motion blur switch), and Pre's shutter is closed (0°).
+fn scene(collapse: bool, inner_move: bool) -> (Session, u64) {
+    let mut s = Session::default();
+    let pre = id(&s.execute("comp.new", json!({"name": "Pre", "width": W, "height": H, "frameRate": 24, "duration": 2})).unwrap(), "comp");
+    let sq = id(&s.execute("layer.newSolid", json!({"name": "Square", "color": "#ffffff", "width": 20, "height": 20})).unwrap(), "layer");
+    if inner_move {
+        s.execute("comp.settings", json!({"shutterAngle": 0})).unwrap();
+        s.execute("comp.setSwitch", json!({"switch": "motionBlur", "value": true})).unwrap();
+        s.execute("layer.setSwitch", json!({"layers": [sq], "switch": "motionBlur", "value": true})).unwrap();
+        for (t, x) in [(0.0, -160.0), (1.0, 320.0)] {
+            s.execute("prop.addKey", json!({"layer": sq, "path": "transform/position", "time": t, "value": [x, 45.0]})).unwrap();
+        }
+    }
+    let main = id(&s.execute("comp.new", json!({"name": "Main", "width": W, "height": H, "frameRate": 24, "duration": 2})).unwrap(), "comp");
+    s.execute("comp.setSwitch", json!({"switch": "motionBlur", "value": true})).unwrap();
+    let l = id(&s.execute("layer.addItem", json!({"item": pre})).unwrap(), "layer");
+    s.execute("layer.setSwitch", json!({"layers": [l], "switch": "motionBlur", "value": true})).unwrap();
+    s.execute("layer.setSwitch", json!({"layers": [l], "switch": "collapse", "value": collapse})).unwrap();
+    if !inner_move {
+        for (t, x) in [(0.0, -160.0), (1.0, 320.0)] {
+            s.execute("prop.addKey", json!({"layer": l, "path": "transform/position", "time": t, "value": [x, 45.0]})).unwrap();
+        }
+    }
+    (s, main)
+}
+
+#[test]
+fn a_collapsed_precomp_layer_blurs_with_its_own_motion() {
+    let (s, main) = scene(true, false);
+    let collapsed = render(&s, main);
+    // The square sits at x = 80 at 0.5 s and smears over 10 px (180° of 20 px).
+    assert!(partial(&collapsed) > 100, "smeared: {}", partial(&collapsed));
+    // As blurred as the same precomp rendered flat.
+    let (s, main) = scene(false, false);
+    let flat = render(&s, main);
+    assert!(max_diff(&collapsed, &flat) < 0.08, "{}", max_diff(&collapsed, &flat));
+    // Motion blur off for the render: sharp.
+    let sharp = s.render(effectcraft_project::ItemId(main), Tick::from_seconds_f64(0.5), RenderOpts { motion_blur: false, ..Default::default() });
+    assert!(partial(&sharp) < 10, "{}", partial(&sharp));
+}
+
+#[test]
+fn collapsed_layers_use_the_containing_comps_shutter() {
+    // Pre's own shutter is closed; drawn into Main (180°) the square's own motion blurs.
+    let (s, main) = scene(true, true);
+    assert!(partial(&render(&s, main)) > 100, "{}", partial(&render(&s, main)));
+    // Rendered flat, Pre uses its own (closed) shutter.
+    let (s, main) = scene(false, true);
+    assert!(partial(&render(&s, main)) < 10, "{}", partial(&render(&s, main)));
+}
+
+/// A shape layer whose rectangle moves inside its contents (not its transform): motion blur
+/// smears it like the same move made with the layer's Position.
+#[test]
+fn animated_shape_content_is_motion_blurred() {
+    let shape = |content: bool, blur: bool| {
+        let mut s = Session::default();
+        let c = id(&s.execute("comp.new", json!({"name": "S", "width": W, "height": H, "frameRate": 24, "duration": 2})).unwrap(), "comp");
+        s.execute("comp.setSwitch", json!({"switch": "motionBlur", "value": true})).unwrap();
+        let l = id(&s.execute("layer.newShape", json!({"kind": "rect", "size": [20, 20], "fill": "#ffffff", "position": [80, 45]})).unwrap(), "layer");
+        s.execute("layer.setSwitch", json!({"layers": [l], "switch": "motionBlur", "value": blur})).unwrap();
+        let (target, base) = if content {
+            let layer = s.active_comp().unwrap().layer(effectcraft_project::LayerId(l)).unwrap().clone();
+            let mut found = None;
+            layer.props.group("contents").unwrap().walk("contents", &mut |_, p| {
+                if found.is_none() && p.match_id == "position" {
+                    found = Some((json!({"prop": p.uid}), p.value.as_vec2()));
+                }
+            });
+            found.unwrap()
+        } else {
+            (json!({"path": "transform/position"}), [80.0, 45.0])
+        };
+        for (t, dx) in [(0.0, -240.0), (1.0, 240.0)] {
+            let mut p = target.clone();
+            p["layer"] = json!(l);
+            p["time"] = json!(t);
+            p["value"] = json!([base[0] + dx, base[1]]);
+            s.execute("prop.addKey", p).unwrap();
+        }
+        render(&s, c)
+    };
+    let content = shape(true, true);
+    assert!(partial(&content) > 100, "smeared: {}", partial(&content));
+    // Like the layer moved by its transform…
+    let moved = shape(false, true);
+    assert!(max_diff(&content, &moved) < 0.15, "{}", max_diff(&content, &moved));
+    // …and sharp with the layer's motion blur switch off.
+    assert!(partial(&shape(true, false)) < 40, "{}", partial(&shape(true, false)));
+}

crates/engine/src/tests_proxy.rs

@@ -182,7 +182,7 @@ fn interpret_proxy_settings_apply_to_the_proxy() {
     assert!(px.footage.invert_alpha);
     let f = match &s.project.item(full).unwrap().kind {
         ItemKind::Footage(f) => f.clone(),
-        _ => unreachable!(),
+        _ => panic!("not footage"),
     };
     assert_eq!(f.alpha, AlphaMode::Straight, "the main footage keeps its interpretation");
 }
@@ -243,7 +243,7 @@ fn guess_alpha_invert_and_linear_light() {
     let h = import(&mut s, "/m/half.png");
     let foot = |s: &Session, i: ItemId| match &s.project.item(i).unwrap().kind {
         ItemKind::Footage(f) => f.clone(),
-        _ => unreachable!(),
+        _ => panic!("not footage"),
     };
     s.execute("file.interpretFootage", json!({"items": [b.0, w.0, h.0], "alpha": "guess"})).unwrap();
     assert_eq!(foot(&s, b).alpha, AlphaMode::Premultiplied);

crates/engine/src/tests_settings.rs

@@ -464,3 +464,25 @@ fn open_recent_increment_and_revert() {
     assert_eq!(autosave::increment_path("/x/v1.ecproj", |p| p.ends_with("v1 2.ecproj")), "/x/v1 3.ecproj");
     let _ = std::fs::remove_dir_all(d);
 }
+
+#[test]
+fn memory_tick_never_waits_for_the_system() {
+    let mut s = Session::default();
+    let t0 = std::time::Instant::now();
+    s.memory_tick();
+    s.memory_tick();
+    // Reading the system's memory starts PowerShell on Windows (about a second): the UI thread
+    // only takes the last reading.
+    assert!(t0.elapsed() < std::time::Duration::from_millis(200), "{:?}", t0.elapsed());
+    if crate::sysinfo::memory().is_some() {
+        let mut got = None;
+        for _ in 0..200 {
+            got = s.memory_watch.latest();
+            if got.is_some() {
+                break;
+            }
+            std::thread::sleep(std::time::Duration::from_millis(50));
+        }
+        assert!(got.is_some_and(|m| m.total > 0), "the reading arrives in the background");
+    }
+}

crates/engine/src/tracking.rs

@@ -407,8 +407,7 @@ impl Session {
             }
             self.bump();
         }
-        if finished {
-            let mut job = self.track_job.take().expect("job");
+        if finished && let Some(mut job) = self.track_job.take() {
             if let Some(t) = job.thread.take() {
                 let _ = t.join();
             }

crates/engine/src/warp.rs

@@ -375,7 +375,7 @@ impl Session {
         if !job.is_finished() {
             return false;
         }
-        let mut job = self.warp_job.take().expect("job");
+        let Some(mut job) = self.warp_job.take() else { return false };
         if let Some(t) = job.thread.take() {
             let _ = t.join();
         }

crates/export/src/lib.rs

@@ -28,6 +28,8 @@
 //! H.264 requires even dimensions: odd output sizes are cropped by one pixel (padded when the
 //! output is a single pixel wide/high).
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 mod encode;
 mod hevc_av1;
 mod out;

crates/expr/src/lib.rs

@@ -24,6 +24,8 @@
 //!   the project through memoized host requests (see [`host`]), so nothing borrowed ever enters
 //!   the JS heap. Expressions reading each other nest up to [`MAX_DEPTH`] levels.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 pub mod host;
 mod noise;
 pub mod rewrite;
@@ -182,6 +184,7 @@ pub fn eval_property(project: &Project, comp: ItemId, layer: LayerId, path: &str
 
 /// Syntax-check an expression (after the array-maths rewrite) without evaluating it.
 pub fn check_syntax(text: &str) -> Result<(), String> {
+    rewrite::check_nesting(text)?;
     runtime::check(text)
 }
 

crates/expr/src/prelude.js

@@ -34,6 +34,15 @@ function __begin(t, v, c, l, path, uid, idx, fd, ti, tt, sv) {
 }
 
 function __finish(r) {
+  // Rethrow from this frame so the runtime's stack unwinds (see `Runtime::script`).
+  try {
+    return __result(r);
+  } catch (e) {
+    throw e;
+  }
+}
+
+function __result(r) {
   r = __v(r);
   if (r !== null && typeof r === 'object' && r.__isLayer) return r.index;
   if (r !== null && typeof r === 'object' && r.__isTextStyle) return r.__out();

crates/expr/src/rewrite.rs

@@ -304,8 +304,11 @@ fn build(toks: Vec<Tok>) -> Vec<Item> {
     for t in toks {
         if t.kind == Kind::Punct && matches!(t.text.as_str(), "(" | "[" | "{") {
             stack.push((t, std::mem::take(&mut cur)));
-        } else if t.kind == Kind::Punct && matches!(t.text.as_str(), ")" | "]" | "}") && stack.last().is_some_and(|(o, _)| closer(&o.text) == t.text) {
-            let (open, parent) = stack.pop().unwrap_or_else(|| unreachable!());
+        } else if t.kind == Kind::Punct
+            && matches!(t.text.as_str(), ")" | "]" | "}")
+            && stack.last().is_some_and(|(o, _)| closer(&o.text) == t.text)
+            && let Some((open, parent)) = stack.pop()
+        {
             let inner = std::mem::replace(&mut cur, parent);
             cur.push(Item::Group { open, inner, close: Some(t) });
         } else {
@@ -545,17 +548,67 @@ fn push_piece(out: &mut String, p: Piece) {
     out.push_str(&p.body);
 }
 
-/// Rewrite an expression's source for array-aware arithmetic. Line breaks are preserved.
-pub fn rewrite(src: &str) -> String {
+/// The deepest nesting (brackets, plus chains of prefix operators) an expression may have,
+/// before and after the rewrite (which nests a call per arithmetic operator). The JavaScript
+/// parser recurses per level and a 2 MiB thread overflows its stack (aborting the app) at
+/// about 60 levels, so deeper expressions are rejected with an error instead.
+pub const MAX_NESTING: usize = 32;
+
+fn nesting(toks: &[Tok]) -> usize {
+    let (mut depth, mut prefix, mut max) = (0usize, 0usize, 0usize);
+    for t in toks {
+        if t.kind == Kind::Punct && matches!(t.text.as_str(), "(" | "[" | "{") {
+            depth += 1;
+        } else if t.kind == Kind::Punct && matches!(t.text.as_str(), ")" | "]" | "}") {
+            depth = depth.saturating_sub(1);
+        }
+        let is_prefix = (t.kind == Kind::Punct && matches!(t.text.as_str(), "!" | "~" | "-" | "+")) || t.is_kw(&["typeof", "void", "delete"]);
+        prefix = if is_prefix { prefix + 1 } else { 0 };
+        max = max.max(depth + prefix);
+    }
+    max
+}
+
+/// An error when `src` nests deeper than [`MAX_NESTING`] levels (before or after the rewrite).
+pub fn check_nesting(src: &str) -> Result<(), String> {
     let (toks, tail) = tokenize(src);
+    if nesting(&toks) > MAX_NESTING {
+        return Err(too_deep());
+    }
     let mut out = rewrite_seq(&build(toks));
     out.push_str(&tail);
+    if nesting(&tokenize(&out).0) > MAX_NESTING {
+        return Err(too_deep());
+    }
+    Ok(())
+}
+
+fn too_deep() -> String {
+    format!("Error: expression is nested too deeply (more than {MAX_NESTING} levels of brackets or chained operators)")
+}
+
+/// Rewrite an expression's source for array-aware arithmetic. Line breaks are preserved.
+/// An expression nested deeper than [`MAX_NESTING`] becomes a `throw` of that error.
+pub fn rewrite(src: &str) -> String {
+    let (toks, tail) = tokenize(src);
+    if nesting(&toks) > MAX_NESTING {
+        return throw_too_deep();
+    }
+    let mut out = rewrite_seq(&build(toks));
+    out.push_str(&tail);
+    if nesting(&tokenize(&out).0) > MAX_NESTING {
+        return throw_too_deep();
+    }
     out
 }
 
+fn throw_too_deep() -> String {
+    format!("throw new RangeError({:?})", too_deep().trim_start_matches("Error: "))
+}
+
 #[cfg(test)]
 mod tests {
-    use super::rewrite;
+    use super::{MAX_NESTING, check_nesting, rewrite};
 
     /// Compare ignoring spaces (newlines are significant).
     fn n(s: &str) -> String {
@@ -599,4 +652,25 @@ mod tests {
         assert_eq!(n(&rewrite("i++ + 1")), n("__add(i++,  1)"));
         assert_eq!(n(&rewrite("2 ** 3 * 2")), n("__mul(2 ** 3,  2)"));
     }
+
+    #[test]
+    fn deep_nesting_is_an_error_not_a_stack_overflow() {
+        // Each level costs the JavaScript parser stack: ~60 nested brackets overflowed a 2 MiB
+        // thread and aborted the app; 100 000 overflowed the rewriter itself.
+        for n in [MAX_NESTING + 1, 100, 100_000] {
+            let parens = "(".repeat(n) + "1" + &")".repeat(n);
+            let unclosed = "[".repeat(n);
+            let sum = vec!["x"; n + 1].join(" + ");
+            let nots = "!".repeat(n) + "x";
+            for src in [parens, unclosed, sum, nots] {
+                assert!(rewrite(&src).starts_with("throw new RangeError("), "{n}");
+                assert!(check_nesting(&src).is_err());
+                assert!(crate::check_syntax(&src).unwrap_err().contains("nested too deeply"));
+            }
+        }
+        let ok = "(".repeat(MAX_NESTING - 2) + "a + b" + &")".repeat(MAX_NESTING - 2);
+        assert!(check_nesting(&ok).is_ok());
+        assert!(crate::check_syntax(&ok).is_ok());
+        assert!(check_nesting(&vec!["x"; 20].join(" + ")).is_ok());
+    }
 }

crates/expr/src/runtime.rs

@@ -238,8 +238,11 @@ impl Runtime {
             self.scripts.clear();
         }
         // A block keeps `let`/`const` local to one evaluation; `{` shares line 1 with the code so
-        // error line numbers match the user's text.
-        let src = format!("{{{}\n}}", crate::rewrite::rewrite(text));
+        // error line numbers match the user's text. Errors are rethrown from the script's own
+        // frame: boa leaves the stack of the inner frames behind when an exception leaves the
+        // script from a nested call (every host request does), and the thread's runtime would
+        // fail every expression with "reached the maximum stack size" after a few hundred.
+        let src = format!("try{{{}\n}}catch(__e){{throw __e}}", crate::rewrite::rewrite(text));
         let s = Script::parse(Source::from_bytes(src.as_bytes()), None, &mut self.ctx).map_err(|e| format_error(&e.to_string(), line_count(text)));
         self.scripts.insert(text.to_string(), s.clone());
         s

crates/expr/src/tests.rs

@@ -388,6 +388,22 @@ fn circular_references_terminate() {
     assert!(matches!(r, Ok(Value::Scalar(_))) || r.is_err(), "{r:?}");
 }
 
+#[test]
+fn errors_and_property_reads_keep_the_runtime_usable() {
+    // Errors thrown inside helpers, and the aborts every property read makes until the host
+    // answers, must not use up the thread's runtime (it used to fail every expression after a
+    // few hundred with "reached the maximum stack size").
+    let f = fx();
+    for _ in 0..3000 {
+        assert!(f.ev(f.b, ROT, "thisComp.layer('Ghost').position", 0.0).is_err());
+    }
+    for i in 0..1000 {
+        let t = i as f64 / 1000.0;
+        assert_close!(f.ev(f.b, ROT, "thisComp.layer('A').transform.rotation", t).unwrap().as_f64(), 90.0 * t);
+    }
+    assert_close!(f.num("time * 2", 1.0), 2.0);
+}
+
 #[test]
 fn effect_slider_reference() {
     let f = fx();

crates/geom/src/lib.rs

@@ -5,6 +5,8 @@
 //! clockwise on screen, 3D uses a left-handed system with +z pointing into the screen, and a 3D
 //! layer's rotation is Orientation (X, Y, Z) followed by X Rotation, Y Rotation, Z Rotation.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 use std::ops::{Add, AddAssign, Div, Mul, MulAssign, Neg, Sub, SubAssign};
 
 use serde::{Deserialize, Serialize};

crates/gpu/src/context.rs

@@ -507,9 +507,12 @@ impl GpuContext {
             .map_err(|e| format!("no device: {e}"))?;
         device.on_uncaptured_error(Arc::new(|e| {
             // Under test a validation error (a WGSL typo invalidates every kernel) fails loudly.
-            if cfg!(test) {
-                panic!("wgpu: {e}");
+            #[cfg(test)]
+            #[allow(clippy::panic)] // test builds only
+            {
+                panic!("wgpu: {e}")
             }
+            #[cfg(not(test))]
             log::error!("wgpu: {e}")
         }));
         GpuContext::new(&adapter, device, queue)

crates/gpu/src/lib.rs

@@ -51,6 +51,8 @@
 //! skip readback entirely with [`Gpu::render_display`], which leaves an RGBA8 texture for
 //! egui-wgpu to draw.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 mod adv3d;
 mod bokeh;
 mod classic3d;

crates/hevcenc/src/frame.rs

@@ -380,7 +380,9 @@ impl<'a> FrameCoder<'a> {
                 return cost;
             }
         }
-        let (cost, e, snap, mode) = best.expect("a coding unit decision");
+        // A coding unit always has at least one candidate mode (intra, or skip/merge in P
+        // slices); without one, report an infinite cost.
+        let Some((cost, e, snap, mode)) = best else { return f64::INFINITY };
         self.restore(&snap);
         *est = e;
         decs.push(CuDec { x: x as u32, y: y as u32, log2, mode });
@@ -452,7 +454,8 @@ impl<'a> FrameCoder<'a> {
                 let mv = match mode {
                     CuMode::Skip { idx } | CuMode::Merge { idx } => self.merge_list(x, y, n)[idx as usize],
                     CuMode::Amvp { mv, .. } => mv,
-                    CuMode::Intra { .. } => unreachable!(),
+                    // Handled by the arm above.
+                    CuMode::Intra { .. } => [0, 0],
                 };
                 let amvp = if let CuMode::Amvp { .. } = mode { self.amvp(x, y, n) } else { [[0; 2]; 2] };
                 let skip = matches!(mode, CuMode::Skip { .. });
@@ -503,7 +506,8 @@ impl<'a> FrameCoder<'a> {
                             self.write_tt(s, x, y, x, y, log2, 0, 0, [true, true], false, false, &mut ti);
                         }
                     }
-                    CuMode::Intra { .. } => unreachable!(),
+                    // Handled by the arm above.
+                    CuMode::Intra { .. } => {}
                 }
                 (eff, self.cu_dist(x, y, n))
             }
@@ -864,7 +868,8 @@ impl<'a> FrameCoder<'a> {
     }
 
     fn predict_inter(&mut self, x: usize, y: usize, n: usize, mv: [i16; 2]) {
-        let refp = self.refp.expect("reference picture");
+        // Inter modes are only tried in P slices, which have a reference picture.
+        let Some(refp) = self.refp else { return };
         for c in 0..3 {
             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 };
@@ -882,7 +887,7 @@ impl<'a> FrameCoder<'a> {
 
     /// Best merge index by SATD of the (approximate) luma prediction.
     fn best_merge(&self, x: usize, y: usize, n: usize, list: &[[i16; 2]; MAX_MERGE_CAND]) -> (usize, u64) {
-        let me = self.me.expect("motion search reference");
+        let Some(me) = self.me else { return (0, u64::MAX / 4) };
         let mut buf = vec![0u16; n * n];
         let mut best = (0, u64::MAX);
         for (i, &mv) in list.iter().enumerate() {
@@ -901,7 +906,7 @@ impl<'a> FrameCoder<'a> {
 
     /// Integer then fractional motion search. Returns (mv, mvp index, SATD cost).
     fn motion_search(&self, x: usize, y: usize, n: usize, amvp: &[[i16; 2]; 2], merge: &[[i16; 2]; MAX_MERGE_CAND]) -> ([i16; 2], u8, u64) {
-        let me = self.me.expect("motion search reference");
+        let Some(me) = self.me else { return (amvp[0], 0, u64::MAX / 4) };
         let (xi, yi) = (x as i32, y as i32);
         let src = &self.src[0][y * self.w + x..];
         let ls = self.lambda_sad;
@@ -1168,7 +1173,8 @@ fn residual_coding<S: Sink>(s: &mut S, lv: &[i32], log2: u32, c: usize, scan_idx
             }
         }
     }
-    let (last_sb, last_pos) = last.expect("residual_coding of an all-zero block");
+    // Callers only code blocks with a nonzero level (coded_block_flag = 1).
+    let Some((last_sb, last_pos)) = last else { return };
     let lx = sb_scan[last_sb].0 as u32 * 4 + pos_scan[last_pos].0 as u32;
     let ly = sb_scan[last_sb].1 as u32 * 4 + pos_scan[last_pos].1 as u32;
     let (cx, cy) = if scan_idx == 2 { (ly, lx) } else { (lx, ly) };

crates/hevcenc/src/lib.rs

@@ -14,6 +14,7 @@
 //! let _hvcc = enc.hvcc();
 //! ```
 
+#![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)]
 
@@ -287,7 +288,7 @@ impl Encoder {
             for y in 0..ch {
                 let row = &src[y.min(h - 1) * stride..][..w];
                 plane.extend(row.iter().map(|&v| (v as u32).min(max) as u16));
-                let last = *plane.last().unwrap();
+                let last = plane.last().copied().unwrap_or(0);
                 plane.extend(std::iter::repeat_n(last, cw - w));
             }
         }

crates/host/src/lib.rs

@@ -3,6 +3,8 @@
 //! Render Queue export through `effectcraft-export` (FilmCraft's encoders). Frontends (desktop,
 //! CLI, MCP, web) start here.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 use std::sync::Arc;
 
 use effectcraft_engine::project::render_queue::OutputFormat;

crates/interchange/src/export.rs

@@ -254,7 +254,7 @@ pub fn export(project: &Project, comp: ItemId, opts: &ExportOptions, prerendered
         bins: HashMap::new(),
         stack: vec![],
     };
-    let seq = ex.sequence(comp);
+    let seq = ex.sequence(comp).ok_or(Error::NoComp(comp.0))?;
     let fc_opts = filmcraft_interchange::ExportOptions { relative_to: opts.relative_to.clone(), name: Some(name), ..Default::default() };
     let (bytes, report) = filmcraft_interchange::export(&ex.fp, seq, opts.format.fc(), &fc_opts)?;
     for e in report.entries {
@@ -390,12 +390,12 @@ impl Exporter<'_> {
         id
     }
 
-    /// The sequence for a comp (created once).
-    fn sequence(&mut self, cid: ItemId) -> fp::ItemId {
+    /// The sequence for a comp (created once); None if `cid` is not a composition.
+    fn sequence(&mut self, cid: ItemId) -> Option<fp::ItemId> {
         if let Some(s) = self.seqs.get(&cid) {
-            return *s;
+            return Some(*s);
         }
-        let comp = self.p.comp_arc(cid).expect("comp");
+        let comp = self.p.comp_arc(cid)?;
         let it = self.p.item(cid);
         let name = it.map(|i| i.name.clone()).unwrap_or_default();
         let settings = fp::SequenceSettings {
@@ -430,12 +430,13 @@ impl Exporter<'_> {
                 Plan::Render(why) => match self.pre.get(&(cid, l.id)).cloned() {
                     Some(r) => {
                         let item = self.prerendered_item(&format!("{} (pre-rendered)", l.name), &r);
-                        let mut ti = self.track_item(item, &l.name, fp::TrackKind::Video, &tm, rate);
-                        ti.source_in = filmcraft_time::Tick::ZERO;
-                        ti.speed = 1.0;
-                        ti.reverse = false;
-                        self.out.prerendered += 1;
-                        Some(ti)
+                        self.track_item(item, &l.name, fp::TrackKind::Video, &tm, rate).map(|mut ti| {
+                            ti.source_in = filmcraft_time::Tick::ZERO;
+                            ti.speed = 1.0;
+                            ti.reverse = false;
+                            self.out.prerendered += 1;
+                            ti
+                        })
                     }
                     None => {
                         self.warn(format!("layer \"{}\" was left out ({why}; pre-rendering is off or unavailable)", l.name));
@@ -457,16 +458,16 @@ impl Exporter<'_> {
                             Some(ItemKind::Solid(s)) => Some(self.solid_item(*item, s.color, &comp)),
                             _ => None,
                         },
-                        LayerSource::Comp { item } if !self.stack.contains(item) => Some(self.sequence(*item)),
+                        LayerSource::Comp { item } if !self.stack.contains(item) => self.sequence(*item),
                         _ => None,
                     };
-                    item.map(|item| {
-                        let mut ti = self.track_item(item, &l.name, fp::TrackKind::Video, &tm, rate);
+                    item.and_then(|item| {
+                        let mut ti = self.track_item(item, &l.name, fp::TrackKind::Video, &tm, rate)?;
                         self.motion(&mut ti, l, &comp, &tm);
                         if let Some(h) = l.props.get("timeRemap").filter(|p| !p.is_animated()) {
                             ti.frame_hold = Some(tick_out(Tick::from_seconds_f64(h.value.as_f64())));
                         }
-                        ti
+                        Some(ti)
                     })
                 }
             };
@@ -486,14 +487,14 @@ impl Exporter<'_> {
                     _ => None,
                 },
                 LayerSource::Comp { item } if self.p.comp(*item).is_some_and(|c| comp_has_audio(self.p, c)) && !self.stack.contains(item) => {
-                    Some(self.sequence(*item))
+                    self.sequence(*item)
                 }
                 _ => None,
             };
             if let Some(item) = sound
                 && !matches!(pl, Plan::Skip(_))
+                && let Some(mut ti) = self.track_item(item, &l.name, fp::TrackKind::Audio, &tm, rate)
             {
-                let mut ti = self.track_item(item, &l.name, fp::TrackKind::Audio, &tm, rate);
                 ti.enabled = l.switches.audio;
                 ti.link = has_video_clip.then_some(link);
                 self.levels(&mut ti, l, &tm);
@@ -529,18 +530,18 @@ impl Exporter<'_> {
             seq.work_area = None;
         }
         self.stack.pop();
-        sid
+        Some(sid)
     }
 
-    fn track_item(&mut self, item: fp::ItemId, name: &str, kind: fp::TrackKind, tm: &Timing, rate: FrameRate) -> fp::TrackItem {
+    fn track_item(&mut self, item: fp::ItemId, name: &str, kind: fp::TrackKind, tm: &Timing, rate: FrameRate) -> Option<fp::TrackItem> {
         let range = filmcraft_time::TimeRange::new(tick_out(tm.source_in), tick_out(Tick((tm.duration.0 as f64 * tm.speed).round() as i64)));
-        let mut ti = self.fp.make_track_item(item, kind, tick_out(tm.start), range, rate_out(rate)).expect("item exists");
+        let mut ti = self.fp.make_track_item(item, kind, tick_out(tm.start), range, rate_out(rate))?;
         ti.name = name.to_string();
         ti.duration = tick_out(tm.duration);
         ti.source_in = tick_out(tm.source_in);
         ti.speed = tm.speed;
         ti.reverse = tm.reverse;
-        ti
+        Some(ti)
     }
 
     /// Transform → Motion + Opacity (clip-time keyframes).
@@ -554,7 +555,7 @@ impl Exporter<'_> {
             _ => (comp.width, comp.height),
         };
         let center = |x: f64, y: f64| -> fp::ParamValue { fp::ParamValue::Vec2(Vec2 { x, y }) };
-        let mut m = ti.effect("motion").cloned().unwrap_or_else(|| fp::find_effect("motion").expect("motion").instance());
+        let Some(mut m) = effect_or_new(ti, "motion") else { return };
         if let Some(p) = tr.get("position") {
             let def = [comp.width as f64 / 2.0, comp.height as f64 / 2.0];
             if p.is_animated() || differs(&p.value, def) {
@@ -594,8 +595,9 @@ impl Exporter<'_> {
             m.params.insert("rotation".into(), param_out(p, &to_clip, |v| fp::ParamValue::Float(v.as_f64())));
         }
         set_effect(ti, m);
-        if let Some(p) = tr.get("opacity") {
-            let mut o = ti.effect("opacity").cloned().unwrap_or_else(|| fp::find_effect("opacity").expect("opacity").instance());
+        if let Some(p) = tr.get("opacity")
+            && let Some(mut o) = effect_or_new(ti, "opacity")
+        {
             o.params.insert("opacity".into(), param_out(p, &to_clip, |v| fp::ParamValue::Float(v.as_f64())));
             if l.blend_mode != effectcraft_color::BlendMode::Normal
                 && let Some(i) = fp::effect::BLEND_MODES.iter().position(|m| m.eq_ignore_ascii_case(l.blend_mode.label()))
@@ -615,7 +617,7 @@ impl Exporter<'_> {
         if (p.value.as_vec2()[0] - p.value.as_vec2()[1]).abs() > 1e-9 {
             self.warn("separate left/right audio levels were exported as the left level");
         }
-        let mut v = ti.effect("volume").cloned().unwrap_or_else(|| fp::find_effect("volume").expect("volume").instance());
+        let Some(mut v) = effect_or_new(ti, "volume") else { return };
         v.params.insert("level".into(), param_out(p, &to_clip, |v| fp::ParamValue::Float(v.as_vec2()[0])));
         set_effect(ti, v);
     }
@@ -634,6 +636,11 @@ fn differs(v: &Value, def: [f64; 2]) -> bool {
     (a[0] - def[0]).abs() > 1e-6 || (a[1] - def[1]).abs() > 1e-6
 }
 
+/// The clip's `id` effect, or a new instance of it (None if the registry has no such effect).
+fn effect_or_new(ti: &fp::TrackItem, id: &str) -> Option<fp::EffectInstance> {
+    ti.effect(id).cloned().or_else(|| fp::find_effect(id).map(|e| e.instance()))
+}
+
 fn set_effect(ti: &mut fp::TrackItem, e: fp::EffectInstance) {
     match ti.effects.iter_mut().find(|x| x.effect == e.effect) {
         Some(x) => *x = e,

crates/interchange/src/import.rs

@@ -45,6 +45,83 @@ pub struct ImportResult {
 
 /// Import a timeline document into `project`. `probe` reads a media file's footage metadata
 /// (None = missing or unreadable: the item becomes a placeholder with the document's metadata).
+/// The deepest element / array nesting accepted in XML and OTIO documents. Real timelines nest
+/// a few levels per nested sequence; parsing several thousand levels overflowed the stack.
+pub const MAX_DEPTH: usize = 256;
+
+/// The deepest element nesting of an XML document (a quick scan that skips comments, CDATA,
+/// processing instructions, declarations and quoted attribute values).
+pub(crate) fn xml_depth(b: &[u8]) -> usize {
+    let (mut i, mut depth, mut max) = (0usize, 0usize, 0usize);
+    let skip_to = |from: usize, end: &[u8]| b.get(from..).and_then(|r| r.windows(end.len()).position(|w| w == end)).map_or(b.len(), |p| from + p + end.len());
+    while let Some(&c) = b.get(i) {
+        if c != b'<' {
+            i += 1;
+            continue;
+        }
+        let rest = b.get(i..).unwrap_or_default();
+        if rest.starts_with(b"<!--") {
+            i = skip_to(i + 4, b"-->");
+        } else if rest.starts_with(b"<![CDATA[") {
+            i = skip_to(i + 9, b"]]>");
+        } else if rest.starts_with(b"<?") {
+            i = skip_to(i + 2, b"?>");
+        } else if rest.starts_with(b"<!") {
+            i = skip_to(i + 2, b">");
+        } else if rest.starts_with(b"</") {
+            depth = depth.saturating_sub(1);
+            i = skip_to(i + 2, b">");
+        } else {
+            // A start tag: find its end outside quotes; `/>` closes it at once.
+            let mut j = i + 1;
+            let mut quote = None;
+            while let Some(&c) = b.get(j) {
+                match quote {
+                    Some(q) if c == q => quote = None,
+                    Some(_) => {}
+                    None if c == b'"' || c == b'\'' => quote = Some(c),
+                    None if c == b'>' => break,
+                    None => {}
+                }
+                j += 1;
+            }
+            if b.get(j.wrapping_sub(1)) != Some(&b'/') {
+                depth += 1;
+                max = max.max(depth);
+            }
+            i = j + 1;
+        }
+    }
+    max
+}
+
+/// The deepest array / object nesting of a JSON document (strings skipped).
+pub(crate) fn json_depth(b: &[u8]) -> usize {
+    let (mut depth, mut max, mut in_str, mut esc) = (0usize, 0usize, false, false);
+    for &c in b {
+        if in_str {
+            if esc {
+                esc = false;
+            } else if c == b'\\' {
+                esc = true;
+            } else if c == b'"' {
+                in_str = false;
+            }
+            continue;
+        }
+        match c {
+            b'"' => in_str = true,
+            b'[' | b'{' => {
+                depth += 1;
+                max = max.max(depth);
+            }
+            b']' | b'}' => depth = depth.saturating_sub(1),
+            _ => {}
+        }
+    }
+    max
+}
+
 pub fn import(
     project: &mut Project,
     bytes: &[u8],
@@ -56,6 +133,16 @@ pub fn import(
         Some(f) => f,
         None => TimelineFormat::detect(bytes, Some(&opts.name)).ok_or(Error::UnknownFormat)?,
     };
+    // The XML and JSON parsers recurse per nesting level: a small file nested thousands of levels
+    // deep overflowed the stack and aborted the app.
+    let depth = match format {
+        TimelineFormat::Fcp7Xml | TimelineFormat::Fcpxml => xml_depth(bytes),
+        TimelineFormat::Otio => json_depth(bytes),
+        _ => 0,
+    };
+    if depth > MAX_DEPTH {
+        return Err(Error::TooDeep(MAX_DEPTH));
+    }
     let fc_opts = filmcraft_interchange::ImportOptions {
         base_dir: opts.base_dir.clone(),
         edl_frame_rate: opts.edl_frame_rate.map(|f| {
@@ -434,7 +521,7 @@ impl Importer<'_> {
         }
         let fit = if ti.scale_to_frame && size.0 > 0 && size.1 > 0 { (comp.width as f64 / size.0 as f64).min(comp.height as f64 / size.1 as f64) } else { 1.0 };
         let lc = l.clone();
-        let tr = l.transform_mut().expect("transform");
+        let Some(tr) = l.transform_mut() else { return };
         // Position / anchor (NaN = centred).
         for (src, dst) in [("position", "position"), ("anchor", "anchor")] {
             let Some(p) = m.param(src) else { continue };

crates/interchange/src/lib.rs

@@ -29,6 +29,8 @@
 //! This crate is L3 and does no file I/O: media files are probed through a callback, pre-rendered
 //! media come in as paths, and documents are bytes.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 mod export;
 mod import;
 #[cfg(test)]
@@ -156,6 +158,8 @@ pub enum Error {
     UnknownFormat,
     #[error("no composition {0}")]
     NoComp(u64),
+    #[error("the timeline document nests more than {0} levels deep")]
+    TooDeep(usize),
 }
 
 pub type Result<T> = std::result::Result<T, Error>;

crates/interchange/src/tests.rs

@@ -498,3 +498,42 @@ fn formats_parse() {
     assert_eq!(par_fraction(0.9), (9, 10));
     assert_eq!(par_fraction(1.0), (1, 1));
 }
+
+#[test]
+fn export_survives_a_precomp_layer_pointing_at_a_non_comp() {
+    // A damaged project: the precomp layer's source is a footage item (or a deleted item).
+    let (mut p, cid) = ae_project();
+    let footage = p.items.iter().find(|(_, i)| matches!(i.kind, ItemKind::Footage(_))).map(|(id, _)| *id).unwrap();
+    for bad in [footage, ItemId(9_999)] {
+        let mut c = (*p.comp_arc(cid).unwrap()).clone();
+        for l in &mut c.layers {
+            if matches!(l.source, LayerSource::Comp { .. }) {
+                l.source = LayerSource::Comp { item: bad };
+            }
+        }
+        p.item_mut(cid).unwrap().kind = ItemKind::Comp(Arc::new(c));
+        for format in [TimelineFormat::Fcp7Xml, TimelineFormat::Fcpxml, TimelineFormat::Otio] {
+            let out = export(&p, cid, &ExportOptions { format, prerender: PrerenderMode::None, ..Default::default() }, &HashMap::new()).unwrap();
+            assert_eq!(out.sequences, 1);
+        }
+    }
+    assert!(matches!(export(&p, footage, &ExportOptions::default(), &HashMap::new()), Err(Error::NoComp(_))));
+}
+
+#[test]
+fn deeply_nested_documents_error_instead_of_overflowing_the_stack() {
+    // A few hundred kilobytes nested 100 000 levels deep overflowed the parsers' stack.
+    let n = 100_000;
+    let docs = [
+        (TimelineFormat::Fcp7Xml, format!("<?xml version=\"1.0\"?><xmeml version=\"5\">{}{}</xmeml>", "<a>".repeat(n), "</a>".repeat(n))),
+        (TimelineFormat::Fcpxml, format!("<?xml version=\"1.0\"?><fcpxml version=\"1.9\">{}{}</fcpxml>", "<a>".repeat(n), "</a>".repeat(n))),
+        (TimelineFormat::Otio, format!("{{\"OTIO_SCHEMA\":\"Timeline.1\",\"tracks\":{}{}}}", "[".repeat(n), "]".repeat(n))),
+    ];
+    for (format, doc) in docs {
+        let mut p = Project::default();
+        let r = import(&mut p, doc.as_bytes(), Some(format), &ImportOptions::default(), &mut |_| None);
+        assert!(matches!(r, Err(Error::TooDeep(_))), "{format:?}");
+    }
+    assert_eq!(super::import::xml_depth(b"<a><!-- <b><b> --><c x='>'/><![CDATA[<d>]]><e></e></a>"), 2);
+    assert_eq!(super::import::json_depth(br#"{"a": "[[[{{", "b": [[1], {"c": "\\\"["}]}"#), 3);
+}

crates/keyframe/src/lib.rs

@@ -441,7 +441,9 @@ pub fn segment_value(keys: &[Keyframe], i: usize, t: Tick, spatial: bool) -> Val
     let dur = (t1 - t0).max(1e-12);
     let x = ((secs(t) - t0) / dur).clamp(0.0, 1.0);
     let lin_out = a.out_interp == Interp::Linear;
-    let lin_in = b.in_interp == Interp::Linear;
+    // A Hold in-side only matters for the segment it ends, which the out side above decides:
+    // it shapes the incoming segment like a linear side, as in the Graph Editor and Lottie export.
+    let lin_in = b.in_interp != Interp::Bezier;
     let is_spatial = spatial && matches!(a.value, Value::Vec2(_) | Value::Vec3(_));
     if is_spatial {
         let p0 = v3(&a.value);
@@ -584,6 +586,17 @@ mod tests {
         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()];

crates/lottie/src/anim.rs

@@ -372,5 +372,5 @@ pub(crate) fn to_bool(j: &Json) -> Option<Value> {
 
 /// Lottie 1-based enum → 0-based popup index.
 pub(crate) fn to_enum1(j: &Json) -> Option<Value> {
-    to_scalar(j).map(|v| Value::Enum((v.as_f64().round() as i64 - 1).max(0) as u32))
+    to_scalar(j).map(|v| Value::Enum((v.as_f64().round() as i64).saturating_sub(1).max(0) as u32))
 }

crates/lottie/src/lib.rs

@@ -18,6 +18,8 @@
 //! Keyframe times in Lottie are frames of the layer's local time, which is EffectCraft's layer
 //! time; layer `ip`/`op`/`st` are composition frames and `sr` is the stretch factor.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 mod anim;
 mod base64;
 mod export;

crates/lottie/src/shapes.rs

@@ -359,10 +359,10 @@ fn import_blend(j: &Json, g: &mut PropGroup) {
 fn import_stroke(im: &Im, j: &Json, g: &mut PropGroup) {
     set(im, g, "width", j.get("w"), &anim::to_scalar);
     if let Some(lc) = int(j, "lc") {
-        set_enum(g, "cap", (lc - 1).clamp(0, 2) as u32);
+        set_enum(g, "cap", lc.saturating_sub(1).clamp(0, 2) as u32);
     }
     if let Some(lj) = int(j, "lj") {
-        set_enum(g, "join", (lj - 1).clamp(0, 2) as u32);
+        set_enum(g, "join", lj.saturating_sub(1).clamp(0, 2) as u32);
     }
     if let Some(p) = g.get_mut("miter") {
         if let Some(ml) = j.get("ml").and_then(Json::as_f64) {
@@ -541,7 +541,7 @@ pub(crate) fn import_items(im: &mut Im, ids: &mut Ids, items: &[Json]) -> Vec<Pr
                     "op" => {
                         set(im, &mut g, "amount", j.get("a"), &anim::to_scalar);
                         if let Some(lj) = int(j, "lj") {
-                            set_enum(&mut g, "join", (lj - 1).clamp(0, 2) as u32);
+                            set_enum(&mut g, "join", lj.saturating_sub(1).clamp(0, 2) as u32);
                         }
                         if let (Some(ml), Some(p)) = (j.get("ml").and_then(Json::as_f64), g.get_mut("miter")) {
                             p.value = Value::Scalar(ml);
@@ -561,7 +561,7 @@ pub(crate) fn import_items(im: &mut Im, ids: &mut Ids, items: &[Json]) -> Vec<Pr
                     }
                     _ => {
                         if let Some(m) = int(j, "mm") {
-                            set_enum(&mut g, "mode", (m - 1).clamp(0, 4) as u32);
+                            set_enum(&mut g, "mode", m.saturating_sub(1).clamp(0, 4) as u32);
                         }
                     }
                 }

crates/lottie/src/tests.rs

@@ -725,3 +725,31 @@ fn text_style_runs_export_as_range_animators() {
     // Played back as an animator, it looks the same.
     compare_renders(&p, cid, &q, nc, 2.0 / 255.0);
 }
+
+#[test]
+fn extreme_enum_numbers_do_not_overflow() {
+    // Line cap / join / merge mode / text-selector enums are 1-based; a huge negative number
+    // (-1e308 rounds to i64::MIN) overflowed the `- 1`.
+    let path = format!("{}/tests/fixtures/shapes-gradient.json", env!("CARGO_MANIFEST_DIR"));
+    let mut doc: Json = serde_json::from_slice(&std::fs::read(path).unwrap()).unwrap();
+    let mut hits = 0;
+    fn patch(j: &mut Json, hits: &mut usize) {
+        match j {
+            Json::Object(o) => {
+                for k in ["lc", "lj", "mm"] {
+                    if o.contains_key(k) {
+                        o.insert(k.into(), json!(-1e308));
+                        *hits += 1;
+                    }
+                }
+                o.values_mut().for_each(|v| patch(v, hits));
+            }
+            Json::Array(a) => a.iter_mut().for_each(|v| patch(v, hits)),
+            _ => {}
+        }
+    }
+    patch(&mut doc, &mut hits);
+    assert!(hits > 0);
+    let mut q = Project::default();
+    import(&mut q, doc.to_string().as_bytes(), "x", "", &mut |_| None).unwrap();
+}

crates/lottie/src/text.rs

@@ -363,7 +363,7 @@ pub(crate) fn import_text(im: &mut Im, ids: &mut Ids, t: &Json, tg: &mut PropGro
                 let mut en = |m: &str, key: &str, max: u32| {
                     let v = s.get(key).and_then(|v| if v.is_object() { v.get("k") } else { Some(v) }).and_then(anim::nums).and_then(|n| n.first().copied());
                     if let (Some(v), Some(p)) = (v, adv.get_mut(m)) {
-                        p.value = Value::Enum(((v.round() as i64 - 1).max(0) as u32).min(max));
+                        p.value = Value::Enum((((v.round() as i64).saturating_sub(1)).max(0) as u32).min(max));
                     }
                 };
                 en("units", "r", 1);

crates/media/src/layered.rs

@@ -73,7 +73,9 @@ pub(crate) fn decode(path: &str, bytes: &[u8], footage: &Footage, op: AlphaOp) -
     if effectcraft_psd::is_psd(bytes) {
         let psd = effectcraft_psd::Psd::parse(bytes.to_vec()).map_err(|e| MediaError::Decode(format!("{path}: {e}")))?;
         // A smart object's embedded file: an embedded document's merged image, or an image.
-        if let Some(uuid) = footage.layer.as_ref().and_then(|l| l.embedded.as_deref()) {
+        if let Some(l) = footage.layer.as_ref()
+            && let Some(uuid) = l.embedded.as_deref()
+        {
             let data = psd.linked_data(uuid).ok_or_else(|| MediaError::Decode(format!("{path}: no embedded file {uuid}")))?;
             let px = if effectcraft_psd::is_psd(data) {
                 let inner = effectcraft_psd::Psd::parse(data.to_vec()).map_err(|e| MediaError::Decode(format!("{path} (smart object): {e}")))?;
@@ -84,7 +86,6 @@ pub(crate) fn decode(path: &str, bytes: &[u8], footage: &Footage, op: AlphaOp) -
                 effectcraft_psd::Pixels { width: rgba.width(), height: rgba.height(), data: rgba.pixels().map(|p| p.0).collect() }
             };
             // A perspective quad or a warp: baked as placed.
-            let l = footage.layer.as_ref().expect("embedded implies a layer");
             if l.placed
                 && let Some(so) = psd.layers.get(l.index as usize).and_then(|pl| pl.smart_object.as_ref())
             {

crates/media/src/lib.rs

@@ -13,6 +13,8 @@
 //! (PNG, JPEG, GIF, WebP, TIFF, BMP, OpenEXR); Photoshop documents (merged image or one layer) come
 //! from `effectcraft-psd` and SVG from `effectcraft-svg` (rasterised at any scale).
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 mod convert;
 pub mod exr_channels;
 mod layered;

crates/media/src/pool.rs

@@ -233,12 +233,16 @@ impl MediaPool {
         }
     }
 
-    /// Drop every cached frame and decoder.
-    pub fn clear(&self) {
+    /// Drop every cached frame (decoders stay open).
+    pub fn clear_frames(&self) {
         let mut c = lock(&self.inner.cache);
         c.lru = Lru::default();
         c.last.clear();
-        drop(c);
+    }
+
+    /// Drop every cached frame and decoder.
+    pub fn clear(&self) {
+        self.clear_frames();
         lock(&self.inner.sources).clear();
     }
 
@@ -602,6 +606,9 @@ impl FootageSource for MediaPool {
     fn set_cache_budget(&self, bytes: usize) {
         self.set_budget(bytes);
     }
+    fn purge(&self) {
+        self.clear_frames();
+    }
     fn cache_budget(&self) -> Option<usize> {
         Some(self.budget())
     }

crates/model/src/lib.rs

@@ -12,6 +12,8 @@
 //! Models are in their own units with +Y up (glTF's convention); the renderer maps them into
 //! After Effects' Y-down pixel space.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 pub mod extrude;
 pub mod gltf;
 pub mod obj;

crates/opusenc/src/lib.rs

@@ -23,6 +23,7 @@
 //! assert_eq!(voip.mode(), Mode::Silk);
 //! ```
 
+#![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)]
 
@@ -317,23 +318,26 @@ impl OpusEncoder {
             }
             Mode::Silk => {
                 let x = self.silk_input(pcm);
-                let sp = self.silk.as_mut().expect("SILK state");
-                let target = sp.target_bits + 0.25 * sp.reservoir;
-                let mut enc = RangeEncoder::new();
-                sp.enc.encode(&x, target.max(24.0), (MAX_FRAME_BYTES * 8) as i32, &mut enc);
-                let bytes = (enc.tell() as usize).div_ceil(8).max(2);
-                let lim = 4.0 * sp.target_bits;
-                sp.reservoir = (sp.reservoir + sp.target_bits - (bytes * 8) as f64).clamp(-lim, lim);
-                packet.extend_from_slice(&enc.done(bytes));
+                // The SILK state exists whenever the mode uses SILK (set with the mode).
+                if let Some(sp) = self.silk.as_mut() {
+                    let target = sp.target_bits + 0.25 * sp.reservoir;
+                    let mut enc = RangeEncoder::new();
+                    sp.enc.encode(&x, target.max(24.0), (MAX_FRAME_BYTES * 8) as i32, &mut enc);
+                    let bytes = (enc.tell() as usize).div_ceil(8).max(2);
+                    let lim = 4.0 * sp.target_bits;
+                    sp.reservoir = (sp.reservoir + sp.target_bits - (bytes * 8) as f64).clamp(-lim, lim);
+                    packet.extend_from_slice(&enc.done(bytes));
+                }
             }
             Mode::Hybrid => {
                 let x = self.silk_input(pcm);
                 let len = self.frame_bytes;
                 let total = (len * 8) as i32;
-                let sp = self.silk.as_mut().expect("SILK state");
                 let celt_min = (total / 5).max(80);
                 let mut enc = RangeEncoder::new();
-                sp.enc.encode(&x, sp.target_bits, total - celt_min, &mut enc);
+                if let Some(sp) = self.silk.as_mut() {
+                    sp.enc.encode(&x, sp.target_bits, total - celt_min, &mut enc);
+                }
                 // No redundancy (RFC 6716 §4.5.1); the flag is present when there is room.
                 if enc.tell() + 17 + 20 <= total {
                     enc.bit_logp(false, 12);
@@ -349,7 +353,7 @@ impl OpusEncoder {
     /// Decimates the input to the SILK internal rate (16-bit scale), one vector per channel.
     fn silk_input(&mut self, pcm: &[f32]) -> Vec<Vec<f32>> {
         let c = self.channels;
-        let sp = self.silk.as_mut().expect("SILK state");
+        let Some(sp) = self.silk.as_mut() else { return vec![vec![]; c] };
         let mut out = Vec::with_capacity(c);
         let mut tmp = vec![0f32; N];
         for ch in 0..c {

crates/path/src/boolean.rs

@@ -1,7 +1,7 @@
 //! Curve-preserving boolean operations on filled [`BezPath`]s, built on `linesweeper`'s robust
 //! sweep-line topology (MIT OR Apache-2.0).
 //!
-//! Adapted from DrawCraft's `vectorcraft-pathops` (`crates/pathops/src/boolean.rs`; our own code,
+//! Adapted from VectorCraft's `vectorcraft-pathops` (`crates/pathops/src/boolean.rs`; our own code,
 //! MIT OR Apache-2.0), reworked to take and return kurbo paths directly.
 //!
 //! Inputs are closed implicitly (a filled open path is painted as if closed). The sweep splits

crates/path/src/fit.rs

@@ -1,4 +1,4 @@
-//! Adapted from DrawCraft's `vectorcraft-pathops` (`crates/pathops/src/fit.rs`; our own code,
+//! Adapted from VectorCraft's `vectorcraft-pathops` (`crates/pathops/src/fit.rs`; our own code,
 //! MIT OR Apache-2.0).
 //!
 //! Least-squares cubic Bézier fitting of point sequences (the classic "fit a cubic with fixed end
@@ -72,8 +72,7 @@ fn bern(t: f64) -> [f64; 4] {
 
 /// Solve the 2x2 normal equations for the handle lengths along the fixed tangents.
 fn generate(pts: &[Point], u: &[f64], t0: Vec2, t1: Vec2) -> CubicBez {
-    let p0 = pts[0];
-    let p3 = *pts.last().unwrap();
+    let (Some(&p0), Some(&p3)) = (pts.first(), pts.last()) else { return CubicBez::new(Point::ZERO, Point::ZERO, Point::ZERO, Point::ZERO) };
     let dir_in = -t1; // handle at the end points backwards
     let (mut c00, mut c01, mut c11, mut x0, mut x1) = (0.0, 0.0, 0.0, 0.0, 0.0);
     for (p, &t) in pts.iter().zip(u) {

crates/path/src/lib.rs

@@ -5,6 +5,8 @@
 //! pucker & bloat, zig zag, twist, wiggle, offset, merge) live in [`ops`]; curve-preserving booleans
 //! (for Merge Paths) in [`boolean`] and curve offsetting in [`offset`].
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 pub mod boolean;
 pub mod feather;
 mod fit;