Implement iris-canvas Phase 2: viewport, compositor, and blend pass#7
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- Exclude crates/appthere-canvas from workspace members (external path dep) - Fix workspace appthere-canvas path (was ../appthere-canvas, now crates/appthere-canvas) - Add features = ["gpu", "font-cache"] to appthere-canvas workspace dep - Uncomment appthere-canvas (+ dioxus feature), vello, wgpu in iris-canvas/Cargo.toml - Replace iris-canvas/src/lib.rs TODO stub: re-export CacheKey, CacheTier, ScrollPhase, ScrollState, GpuTexture, PageSource, RenderError from appthere_canvas; compile-time assertion that TileCoord satisfies CacheKey - ADR/006: status Proposed → Accepted; add Implementation notes section - CLAUDE.md: iris-canvas gate updated to GATE OPEN (ADR 006) cargo check --workspace: zero errors cargo test --workspace: 55 tests, 0 failures https://claude.ai/code/session_01X8kb2QAMhu3VtT8C2CkdYa
…ompositor, IrisCanvas - TileKey: (LayerId, TileCoord) composite key satisfying appthere_canvas::CacheKey - CanvasViewport: screen-center-anchored pan, zoom/rotation math, screen↔doc round-trip transforms, visible_doc_rect AABB for culling, zoom_to anchor-stable - Compositor: lazy BlendPass pipeline (Normal blend via PREMULTIPLIED_ALPHA_BLENDING render pipeline), DFS bottom-to-top layer iteration, tile upload to Rgba16Float, tile_params NDC quad corners per viewport transform - IrisCanvas Dioxus component (placeholder div, BLOCKED on appthere-canvas paint hook) with complete IrisPageSource / PageSource<Key = ()> implementation - Integration tests: viewport round-trips, TileKey hash, LayerTree structure - Upgrade wgpu workspace dep 22→26 to match appthere-canvas; add bytemuck, dioxus deps - Split compositor/mod.rs under 100-line ceiling into mod.rs + composite.rs - All 11 iris-canvas tests pass; clippy -D warnings clean; cargo test --workspace green https://claude.ai/code/session_01X8kb2QAMhu3VtT8C2CkdYa
…urce
- Add anyrender_vello = "0.6.2" dep to iris-canvas (Option B: bridge in iris-canvas)
- New paint_bridge.rs: IrisCanvasPaintSource implements anyrender_vello::CustomPaintSource
- resume(): clones DeviceHandle (wgpu::Device + Queue are Clone in wgpu 26)
- suspend(): drops device handle and last registered TextureHandle
- render(): reads viewport/tree from Arc<Mutex<>>, calls compositor.composite(),
unregisters old TextureHandle, calls ctx.register_texture(gpu_texture.inner),
returns Some(TextureHandle) — None skips the frame (Blitz reuses last texture)
- Update canvas_widget.rs: replace placeholder div with working use_wgpu integration
- shared_viewport and shared_tree are Arc<Mutex<>> updated on each Dioxus re-render
- use_wgpu captures cloned Arcs via FnOnce; auto-unregisters on component drop
- RSX: <canvas "src"="{canvas_id}"> (quoted attr bypasses Dioxus schema;
blitz-dom reads "src" on <canvas> elements to load custom paint sources)
- Add #[derive(Clone)] to LayerTree in iris-pixel (all fields already Clone)
- All 11 iris-canvas tests pass; clippy -D warnings clean; cargo test --workspace green
API discoveries vs audit assumptions:
- DeviceHandle.device / .queue are public fields (not getters) — direct field access
- TextureHandle: Clone — can clone for storage while returning from render()
- anyrender_vello uses wgpu = "26" — same as iris-canvas, types compatible
- use_wgpu is at dioxus::native::use_wgpu (not dioxus::prelude)
- canvas src attribute must be quoted "src" in RSX (not in Dioxus element schema)
https://claude.ai/code/session_01X8kb2QAMhu3VtT8C2CkdYa
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Summary
Implements the core Iris infinite-canvas rendering pipeline (Phase 2 per SPEC.md §6.2):
use_wgpuhook andCustomPaintSourcebridgeThis unblocks Phase 2 delivery and establishes the foundation for Phase 3+ (vector/text layers, additional blend modes).
Key Changes
New modules
viewport.rs(221 lines):CanvasViewportstruct with screen↔document coordinate transforms, zoom anchoring, and visible-rect culling. Includes 8 unit tests covering round-trip transforms, rotation, and zoom clamping.compositor/mod.rs(66 lines):Compositorwrapper managing lazyBlendPassinitialization and the maincomposite()entry point.compositor/pass.rs(193 lines):BlendPasswgpu render pipeline (vertex/fragment shaders, bind groups, sampler) for Normal blend viaPREMULTIPLIED_ALPHA_BLENDING.compositor/composite.rs(133 lines): Core composite logic—layer iteration (DFS bottom-to-top), tile selection via visible rect, NDC quad computation, and blend pass invocation.compositor/upload.rs(95 lines): CPU→GPU tile upload helpers (upload_tile,transparent_tile) forRgba16Floattextures.canvas_widget.rs(136 lines):IrisCanvasDioxus component with reactive signals for viewport/tree,use_wgpuhook integration, andIrisPageSourcefor headless rendering.paint_bridge.rs(93 lines):IrisCanvasPaintSourceimplementingCustomPaintSourceto bridgeCompositorinto Blitz's paint loop.key.rs(41 lines):TileKeycache key type (layer ID + tile coordinate) for future page-cache integration.shaders/normal_blend.wgsl(65 lines): Vertex/fragment shaders with bilinear corner interpolation for rotated tiles and premultiplied-alpha blending.Modified files
lib.rs: Expose public API (CanvasViewport,IrisCanvas,CompositorError, re-exports fromappthere-canvas).Cargo.toml: Uncommentappthere-canvas,anyrender-vello,wgpu,kurbo,bytemuck,thiserrordependencies (gate now open per ADR 006).tests/integration.rs: Add 5 integration tests covering viewport transforms, tile selection, andTileKeyhashing.ADR/006-shared-canvas-extraction.md: Update status to "Accepted" and document implementation completion.SPEC.md: Update §6.2 to reflect screen-center pan convention (Q1 decision).CLAUDE.md: Update gating table—iris-canvasgate is now open.Cargo.toml: Excludeappthere-canvasfrom workspace (external dependency).Implementation Details
Pan convention (Q1 decision)
Document-space coordinate visible at the screen center, not top-left. Rotation is always around screen center. This avoids undefined behavior when rotation is non-zero.
Blend mode phasing
Phase 2 supports Normal blend only via hardware
PREMULTIPLIED_ALPHA_BLENDING. Non-Normal modes log a warning and skip the layer. Phase 4 will add compute shaders for additional blend modes (SPEC.md §4.8).Tile rendering
Rgba16Floattextures (f16 RGBA, straight alphahttps://claude.ai/code/session_01X8kb2QAMhu3VtT8C2CkdYa