* engine: display LUT without the 32-bit preview for the GPU canvas shader; keep values above 1.0 in texture_buffer
ColorState::gpu_canvas_lut leaves View > 32-bit Preview Options out of the display LUT
(the canvas shader applies exposure/gamma before it, on unclipped float texels), and
ColorState::hdr_preview returns the active preview. CanvasDisplay::texture_buffer no
longer clamps linear values to 1.0 before sRGB-encoding them (the 8-bit path clamps
afterwards with the same result).
Refs #46
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* GPU canvas: Rgba16Float display texture for 16/32-bit documents (#46)
16- and 32-bit documents get an Rgba16Float canvas texture when the adapter can
sample, filter, render to and copy it (Rgba8Unorm stays for 8-bit documents, as the
fallback, and for high-bit documents over 100 MP, about 1.07 GB with mips), so smooth
gradients no longer band through 8 bits. Both the wgpu compositor path (encode pass
with 16F pipelines; no upper clamp) and the CPU band/rect upload path (f32 -> half
conversion, reused band buffer) write it. The 32-bit preview (exposure/gamma) moves
into the canvas shader, before the colour-management/proof LUT, so values above 1.0
are exposed into range instead of clipped. GpuCanvas::read_texels / texture_info for
tests and benchmarks; PHOTOCRAFT_CANVAS_F16=0/1 disables the float canvas / ignores
the budget. large_image_bench gains --depth 16|32.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
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