RenderRequest gains a sample format (OutputDepth: U8 for previews, U16, F32Linear); deep renders
run the per-pixel stage with the exact sRGB curve and return Rendered::deep alongside the 8-bit
image (GPU stays 8-bit: deep exports render on the CPU). Export encodes deep renders: 16-bit PNG and
TIFF, 32-bit float linear TIFF with a linear ICC profile we generate, 10-bit AVIF (YCbCr planes into
ravif). Output sharpening and watermarks work on deep images. ExportOptions.bitDepth with per-format
defaults (TIFF 16-bit, others 8-bit), export dialog bit depth choice (remembered with the last
export), MCP export schema. Tests: a smooth gradient has 1024 levels in a 16-bit TIFF vs 13 in
8-bit, float TIFF decodes to the same light as 16-bit, per-format depth rules, AVIF 10-bit.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Renders run in dedicated module Web Workers, each a second instance of the app's wasm module
(index.html compiles it once and posts the WebAssembly.Module to worker.js). A job crosses as
JSON (WireJob: source, settings, request); the worker reads originals and cached thumbnails from
browser storage itself, keeps decoded sources and per-view stage caches, and transfers RGBA back.
Jobs follow the worker that decoded the photo; the loupe waits for it. No wasm threads or
SharedArrayBuffer needed; falls back to inline rendering if no worker starts (?workers=0).
Thumbnail disk cache on the web: thumbs/<key>.jpg in OPFS/IndexedDB with an index on the main
thread, pruned to the desktop budget (2 GB → 80 %, LRU).
ui-egui: RenderOffload hook in the Renderer (queue/priorities/dedup stay in the UI).
engine: RenderJob.origin + MediaCache::origin_ref; preview: encode_jpeg/decode_jpeg public.
xtask web: copies worker.js; --serve sends COOP/COEP/CORP (documented in docs/web.md).
Headless Chrome, cold load + grid scroll, 24 demo photos: main-thread busy 12.4 s → 0.7–1.1 s,
long tasks 23 (max 1.1 s) → 0; grid filled in 6.3–8.4 s vs 13–16 s; slider job 4 ms.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
