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>
- memory::budget (default min(25% RAM, 1.5 GiB); LIGHTCRAFT_MEMORY_MB, app.memoryBudget):
half for engine caches (sources + rendered previews, LRU across them via a global
use tick; the photo on screen stays), a quarter for decodes in flight (WorkGate:
thumbnails, prefetch and import probes wait; loupe/export loads never wait), an
eighth for the GPU free pool.
- GPU: best-fit buffer reuse (<= 25% slack), buffers released outside a render are
pooled at once (no stranded retired lists), pool trimmed after 3 s idle.
- Decodes drop file bytes and raw samples early, colour/crop/orient in place.
- macOS: apps install malloc_zone_pressure_relief as the release hook (after each
decode, import and idle trim): freed large blocks no longer stay resident.
14 raws + loupe + 12 steps (M4 Pro): peak RSS 1.9-2.3 GB -> 0.83-0.99 GB, footprint
2.5-2.6 GB -> 0.91-0.96 GB, heap peak 930 -> 656 MB; stepping median ~13 ms.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- Once the current photo's loupe render is done, the next and previous photos in filmstrip
order get a background loupe job (Slot::Prefetch, priority below on-screen thumbnails,
once per settings): the decoded 2560 px source is kept in the engine's bounded preview
LRU and the view render is cached, so stepping to a neighbour shows its developed image
in ~50 ms and then re-renders only on the GPU.
- lightcraft_gpu::warm_up (called when the app is created) builds the device and kernels on
a background thread; gpu::ready() answers without blocking and ui.inspect uses it, so the
UI thread never waits for device creation.
- docs/gpu-pipeline.md: opening-a-photo section.
Stepping through 24 MP raws in the loupe (real app): full render 220–580 ms → 45–62 ms.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
`media::develop` renders on the GPU when available (views, render_now, exports;
thumbnails stay on the CPU) and falls back to the CPU otherwise. `app.gpu
{enabled?}` toggles it at runtime, `LIGHTCRAFT_GPU=0` disables it for the process,
`ui.inspect` reports the adapter under perf.gpu.
Performance: dropped device buffers are recycled once their thread has submitted
(fresh 100-300 MB allocations per pass cost as much as the passes), Gaussian
passes ping-pong between two buffers and read all channels of a pixel at once,
and long box radii slide over longer chunks. LIGHTCRAFT_PROFILE prints real GPU
stage timings. render_bench prints CPU and GPU columns and the CPU/GPU difference.
24 MP ARW, loaded machine, min of 7: cold loupe 415 -> 32 ms, exposure drag
22-42 -> 3.9 ms, NR drag (1920) 301+ -> 18 ms, export render 1037+ -> 291 ms;
max 1 LSB difference. docs/gpu-pipeline.md describes the implementation.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
New L3 crate `lightcraft-gpu`: a wgpu device (Metal/Vulkan/DX12; none on wasm32),
WGSL kernels compiled once, buffer/dispatch/readback helpers, and a renderer that
runs the per-pixel stage (tone map, highlights/shadows, clarity/texture/sharpen,
dehaze, local mask terms, OkLCh colour ops, grading, vignette, gamut map, sRGB
encode, curves, grain) on the device. Earlier stages still run on the CPU and are
uploaded (per-stage hybrid). Stage results are cached per view next to the CPU
StageCache (new `StageCache::extension`).
The CPU pipeline stays the oracle and shares its resolved parameters with the
kernels: `finish::FinishParams` / `mask_terms`, `pipeline::plan` (stage-cache keys),
`local::plane_sigmas` / `nr_params` / `wb_matrix_for`, exact LUTs and OkLab
matrices exported for the shader prelude. Equivalence tests (skip without an
adapter): mean |d| < 0.5 LSB, max <= 3 LSB; measured max 1 LSB on Apple M4 Pro.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>