M13.32: View ▸ New Viewer — several Composition viewers

- PanelKind::Viewer(n): more Composition viewers (panels::viewers). One is active (the full
  interactive viewer, showing the active comp); the others show their own comp's frame at that
  comp's current time (CPU or GPU frames, their own textures) and become active on a click or
  their tab, their comp becoming the active comp.
- view.newViewer (View menu, the Composition panel menu, Alt+Shift+N): a new viewer of the
  active comp next to the one in use, which is locked. Opening a comp while the active viewer
  is locked shows it in an unlocked viewer, or a new one when every viewer is locked. Closing
  the active viewer hands over to another with its comp. Tabs are named after their comp, with
  their own lock and swatch; Preview full screen maximizes the active viewer.
- UI state: viewers (comp per viewer) and active_viewer (serde).
- Tests: ui_viewers (lock on New Viewer, routing, click to activate, all locked → new viewer,
  close hand-over, tab titles; an ignored snapshot). The bounded-drag frames test asserts what
  holds when freed addresses are reused. Docs: parity, control protocol.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

docs/control-protocol.md

@@ -86,7 +86,8 @@ Points are logical window coordinates. A target is `{id}` (the element's centre;
 
 Element ids are stable, for example `tools.Selection`, `panel.Timeline`, `panel.tab.EffectControls`,
 `panel.tab.Timeline.<comp>` (one Timeline tab per open comp; `panel.tab.Timeline` is the shown
-one), `header.workspace.Animation`, `project.item.<id>` (a double-click opens the item, Enter
+one), `panel.tab.Viewer(<n>)` and `viewers.<n>` (View ▸ New Viewer's other Composition viewers;
+`viewers.0` is the Composition panel while another viewer is active), `header.workspace.Animation`, `project.item.<id>` (a double-click opens the item, Enter
 renames it), `viewer.comp`, `viewer.handle.<layer>.<i>`,
 `timeline.layer.<id>.bar`, `timeline.layer.<id>.twirl`, `timeline.layer.<id>.row` (click selects,
 Enter or a double-click renames, drag reorders), `timeline.prop.<uid>.stopwatch`,

docs/parity.md

@@ -163,7 +163,7 @@ the disk cache in the formats wave; the 3D Camera Tracker in M12.6.)
 | Web | 98% | 0.1 | No shared-memory threads inside one engine instance (the decided design is one engine instance per worker; a threaded build needs nightly `build-std`) (M13.30: Render Queue, analyses and Content-Aware Fill render on each job worker's own WebGPU device in passes, particles and Advanced 3D read back under keys, layer buffers in the browser's disk cache; browser storage, Web Audio, Web Worker renders/analyses, WebGPU viewer and offline install landed in M15.2; viewer frames in frame workers fed by project diffs, Roto Brush propagation in a worker, non-blocking `wait: true` jobs and a browser Media Browser (File System Access folders, browser storage) in M13.10; WEB-1 in M13.24: GPU effects and the GPU compositor in the frame workers on their own WebGPU devices with deferred readbacks (frames render in passes; Backend Auto per comp), the disk cache in the Origin Private File System (written by the workers with sync access handles, LRU under the settings' limit, served after a reload), the storage manager (Settings ▸ Disk ▸ Browser Storage, `storage.info` / `storage.persist` / `storage.clear`), and a WGSL constant Chrome rejected (it disabled every GPU kernel in Chrome) fixed) |
 | 3D | 88% | 5.5 | multi-view layouts, the Extended Viewer for Advanced 3D comps (Classic 3D Extended Viewer landed in M13.5 UI completion); collapsed precomps of another size seen through the parent's camera render (fixed in M13.2); stereo rigs, orbit nulls, lights controlled by the camera, cameras/lights from glTF models, environment backgrounds, Advanced 3D motion blur, blend modes and track mattes landed in M7.7; Classic 3D iris-shaped bokeh with highlights, progressive depth of field on tilted layers and the focus-link commands landed in M13.5; Advanced 3D depth of field with the iris and highlight options, collapsed precomps as real Advanced 3D geometry and extruded text/shape strokes landed in M13.8; Advanced 3D (glTF/OBJ models, primitives, extruded text and shapes, PBR, image-based light, shadow maps, GPU rasteriser) in M7.4–M7.6; Advanced 3D end to end on the GPU (motion blur, iris depth of field, compositing) in M13.11 |
 | Effects | ≈ 85% | 3.0 | GPU versions of the remaining effects (280 run on the GPU since M13.29, EFF-5: M13.28 added the remaining pixel effects and the geometry and audio generators (Lightning, Advanced Lightning, Beam, Lens Flare, Radio Waves, Vegas, Stroke, Scribble, Write-on, Paint Bucket, Eyedropper Fill, CC Glue Gun, CC Threads, Audio Spectrum / Waveform, Basic / Path Text); M13.29 added the particle effects (CC Particle World / Systems II, Particle Playground, CC Ball Action, CC Pixel Polly, CC Scatterize, Curl Noise) and removed the fallbacks of Shatter's wireframe views, Foam's extras, Timewarp's Matte Layer, strong Warp Fisheye / Twist bends and custom `.ocio` configs; M13.23 added the 3D Channel and Immersive Video families, Apply Color LUT, the OCIO effects, Color Profile Converter and the simulations' render passes (Card Wipe included); M13.22 added the CC light family, the CC transitions, Block Dissolve, Radial Shadow, CC Bender / Blobbylize / Cylinder / Sphere / Spotlight / Environment, 3D Glasses, Numbers, Timecode and the time effects joined the 166 of M13.13; Fractal and the analysis / tool effects still render on the CPU) and the missing controls listed as partial in [effects.md](effects.md) (every After Effects effect exists since M9.11, M12.5 and M12.6; parameter names, order, twirl-downs, popups, units and defaults were aligned in M9.12) |
-| Interface | 75% | 5.0 | more Learn tutorials and pixel-level fidelity of dialogs; View ▸ New Viewer (several unlocked viewers) (an automation id on every control of Composition and Solid Settings, Group / Ungroup Shapes in the Layer menu, Window ▸ Learn, the flowchart shortcuts and Reveal in Explorer landed in M3.10 and M3.13; the Home ▸ Templates gallery (eight original built-in templates, user templates from File ▸ Save as Template…) and View ▸ Simulate Output ▸ My Custom RGB… landed in M13.25; Timeline layer reordering by drag, a non-snapping viewer pan, a working rename field and twirl arrows, and the full set of property reveal shortcuts — double presses, Alt+Shift keyframes, Ctrl+` — landed in M13.17–M13.20; the Home ▸ Learn tab with interactive tutorials and a UI fidelity pass landed in M13.5 UI completion; visual editors for Lumetri RGB / hue-saturation curves, Colorama's output cycle wheel, Glow's colour map and Reshape's correspondence points (viewer handles), a scrolling Preview panel and AE-style Composition / Timeline tabs (close, label swatch, viewer lock) landed in M13.10; Timeline outline and Project panel columns scroll horizontally, the Layer Style dialog, ROI resize handles, Pan Behind snapping and 3D Reference Axes landed in M13.5; native macOS menu bar, Timeline columns/search/reveal-add, Home screen with recent projects and all AE workspaces landed; viewer rulers/snapping/channels/snapshots landed in M0.13) |
+| Interface | 75% | 5.0 | more Learn tutorials and pixel-level fidelity of dialogs (View ▸ New Viewer landed in M13.32; an automation id on every control of Composition and Solid Settings, Group / Ungroup Shapes in the Layer menu, Window ▸ Learn, the flowchart shortcuts and Reveal in Explorer landed in M3.10 and M3.13; the Home ▸ Templates gallery (eight original built-in templates, user templates from File ▸ Save as Template…) and View ▸ Simulate Output ▸ My Custom RGB… landed in M13.25; Timeline layer reordering by drag, a non-snapping viewer pan, a working rename field and twirl arrows, and the full set of property reveal shortcuts — double presses, Alt+Shift keyframes, Ctrl+` — landed in M13.17–M13.20; the Home ▸ Learn tab with interactive tutorials and a UI fidelity pass landed in M13.5 UI completion; visual editors for Lumetri RGB / hue-saturation curves, Colorama's output cycle wheel, Glow's colour map and Reshape's correspondence points (viewer handles), a scrolling Preview panel and AE-style Composition / Timeline tabs (close, label swatch, viewer lock) landed in M13.10; Timeline outline and Project panel columns scroll horizontally, the Layer Style dialog, ROI resize handles, Pan Behind snapping and 3D Reference Axes landed in M13.5; native macOS menu bar, Timeline columns/search/reveal-add, Home screen with recent projects and all AE workspaces landed; viewer rulers/snapping/channels/snapshots landed in M0.13) |
 | Project | ≈ 68% | 5.5 | OCIO displays beyond the built-in tone map; relative footage paths and relinking when a project moves (unsaved-changes prompts, a modified mark that follows undo and project files that name their version and always reopen landed in M3.9 and M3.14; auto-save and crash recovery in M3.7; Color Engine with OCIO/ACES working spaces, HDR compand/tone mapping, Rec. 2100 PQ/HLG output, Feet + Frames, display colour management, Simulate Output and the locked viewer landed in M7.7; proxies and Interpret Footage fields / pixel aspect / alpha guess landed: PRJ-8, PRJ-3) |
 | Masks & roto | 74% | 5.0 | Roto Brush's learned (3.0) segmentation model (variable-width mask feather points with the Mask Feather tool landed in M13.5; mask tracking and Mask Interpolation landed in M6.6; Roto Brush & Refine Edge with graph-cut segmentation, flow propagation, edge matting, decontamination and Freeze in M6.7) |
 | Preview | 77% | 2.8 | GPU effects for the audio-driven effects and the stepped particle systems; content-keyed RAM preview frames (an edit drops every comp's), audio scrubbing, more snapshot slots (RAM preview keys with the render options, least-recently-shown eviction, Auto resolution while playing, Cache Before Playback that fits, an achieved-fps readout, Cache Frames When Idle and purges that clear what they name landed in M4.5–M4.8; 3D channel, VR, OCIO, Card Wipe and the simulations' render passes run on the GPU since M13.23; Advanced 3D layers with blend modes / track mattes / Preserve Transparency and environment backgrounds composite on the GPU since M13.22; pooled GPU textures and fused quantisation since M13.13: Lower Third GPU warm 21 → 4 ms/frame, and Auto now picks the CPU or the GPU per comp from measured frame times; Advanced 3D runs — raster, motion blur, iris depth of field, compositing — and wireframes run on the GPU since M13.11: CPU warm 3394 → GPU warm 290 ms/frame at 1920×1080 (11.7×; Half 968 → 85 ms), GPU ≠ CPU on 0.005 % of pixels, on an M4 Pro under load; Classic 3D bokeh depth of field — iris shapes, highlights, fringe, progressive blur on tilted planes — runs in WGSL since M13.6: 3D Showcase GPU warm 205 → 54 ms/frame at full size on an M4 Pro; the Preview panel's five shortcuts with their own Include / Loop / Cache Before Playback / Range / Play From / Frame Rate / Skip / Resolution / Full Screen / stop options and `playback.settings.get/set` landed in M13.8; Classic 3D runs and adjustment layers composite on the GPU since M12.7; persistent disk cache with the blue cache bar landed; region of interest, snapshots, exposure and Fast Previews landed in M0.13) |
@@ -422,6 +422,14 @@ layers); the Graph Editor has Auto-Select Graph Type (the default: the speed gra
 spatial properties are shown, else the value graph; choosing Value or Speed turns it off). Graph
 Editor keys are small squares whatever their interpolation, as in After Effects.
 
+Since (M13.32): View ▸ New Viewer (Alt+Shift+N, also in the Composition panel menu) opens
+another Composition viewer as its own panel, as in After Effects. The viewer in use is locked,
+so it keeps its comp. One viewer is active: it is the interactive one and shows the active comp.
+The others show their own comp's frame at that comp's current time, and a click (or their tab)
+makes them active. Opening a comp while the active viewer is locked shows it in an unlocked
+viewer, or in a new one if every viewer is locked. Closing a viewer hands over to another one,
+with that viewer's comp. Each viewer's tab is named after its comp, with its own lock.
+
 Since (M4.14): RAM preview frames are keyed by their comp's content, not the project revision. An
 edit keeps the cached frames (the green bar) of every comp it doesn't touch, and undo finds the
 frames of the state it returns to, as in After Effects. The identity costs about 0.1 ms on the
@@ -743,7 +751,7 @@ are pinned bit for bit by golden hashes (`crates/effects/tests/particle_golden.r
     animators).~~ (M4.13)
 17. ~~Content-keyed RAM preview frames, so an edit keeps the frames of comps it doesn't touch.~~
     (M4.14)
-18. View ▸ New Viewer (several unlocked Composition viewers), nested comp markers on the
+18. ~~View ▸ New Viewer (several Composition viewers)~~ (M13.32); nested comp markers on the
     precomp layer bar, audio scrubbing.
 
 At the original audit the engine underneath (keyframes, expressions, shape operators, text