New L3 crate effectcraft-gpu: a wgpu compute backend for the per-frame
compositing walk (layer transforms with the CPU's nearest/bilinear/bicubic
sampling and minification pre-filter, motion-blur accumulation, track
mattes, Preserve Transparency, layer style passes and knockout, all 38
blend modes as a WGSL port of color::blend, 8/16 bpc clamp+quantise,
colour-space conversions). 3D runs, adjustment and wireframe layers run on
the CPU between GPU steps. GPU effects with the CPU semantics: Gaussian,
Fast Box and Directional Blur, Glow, Levels, Curves, Hue/Saturation, Tint,
Fill, Gradient Ramp, Fractal Noise, Drop Shadow, Brightness & Contrast,
Exposure, Invert, Transform (registry gpu badge from effects::GPU_EFFECTS).
render: Backend (Cpu/Gpu/Auto) in RenderOpts, the Accelerator trait and
Renderer::accel, GPU effect chains in the effect stack, hooks for the GPU
walk. Project setting gpu_acceleration (Mercury GPU Acceleration / Software
Only), render.backend command, file.projectSettings renderer. Session and
Render Queue exports carry the accelerator. CLI --gpu and bench --gpu.
Tests compare GPU vs CPU renders (blend modes x bit depths, transforms,
masks, mattes, motion blur, colour management, styles, collapse,
adjustment fallback, every GPU effect) and skip without an adapter.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
