The canvas blit used a nearest sampler, so the upscaled low-res proxy looked
blocky. Added a Linear sampler + `CanvasBlitPipeline::blit_smooth`; the raster
render uses it only for the proxy path (full-res canvas stays nearest/crisp). The
bind-group layout already declares the canvas texture filterable, so no layout
change was needed.
Scrubbing onto a paged-out raster keyframe flashed blank for the 1-2 frames its
full pixels took to page in. Now a low-res proxy is shown in that gap.
- core: `MediaKind::RasterProxy` (id derived from the keyframe id via
`raster_proxy_media_id`); `brush_engine::encode_raster_proxy_png` downscales a full
RGBA buffer to a ≤192px-long-edge PNG. Save writes a proxy beside each resident
frame's full PNG (paged-out frames keep their existing proxy row, like the full).
Load eagerly decodes proxies (small) into `RasterKeyframe::proxy`.
- editor: a separate `proxy_layer_cache` in the GPU brush (own recency LRU, budget 64
since each is ~1/100th a full frame) + `ensure_proxy_texture`/`get_proxy_texture`.
The raster render, when the full texture isn't resident, blits the proxy mapped to
the keyframe's FULL logical dims so it upscales via the sampler. F3 VRAM figure now
includes proxy textures.
When the full pixels land (async fault-in), the full path takes over automatically.
Proxies only exist after a save+reload; freshly-painted unsaved frames stay resident
so they need none.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
`raster_layer_cache` (one ~w·h·16-byte Rgba16Float CanvasPair per keyframe) had no
size cap — scrubbing a long timeline grew VRAM without bound (~33 MB/frame at 1080p),
the largest unbounded consumer. Added a recency LRU (RASTER_LAYER_CACHE_MAX = 12):
`ensure_layer_texture` bumps the frame to most-recent and evicts the oldest past the
budget; the shown frame (and any rendered this pass) is always most-recent so it's
never the victim. Evicted textures re-upload cheaply from the resident/faulted-in
pixels on revisit. `remove_layer_texture` keeps the LRU in sync.
F3 debug overlay now reports the tracked VRAM (raster cache MB + frame count), pushed
from the GPU brush whenever the cache changes (wgpu exposes no allocator query).
Color correctness:
- Unpremultiply before the sRGB OETF on the display and export blits;
encoding premultiplied color corrupted antialiased/transparent edges.
- Tag exported video as full-range BT.709 (matrix/primaries/transfer).
- Run perception effects (invert, brightness/contrast, hue/saturation)
in gamma space to match standard editors.
- Interpolate gradients in gamma space across the raster and vector paths.
- Render effect thumbnails in the same linear space as the live pipeline.
Brush performance:
- Store the raster canvas as Rgba16Float (no shadow banding from 8-bit
linear), with an incremental per-tile ping-pong sync replacing the
per-frame full-canvas copy.
- Do the linear->sRGB readback conversion on the GPU and reuse a cached
scratch texture, dropping a ~110ms-per-stroke CPU decode.
Cleanup:
- Single COLOR_WGSL prelude and shared CPU sRGB scalars instead of ~8
duplicated copies of the transfer functions.
- Shared compute-pipeline builder; smudge folded onto the tile-sync path.
Skyler Lehmkuhl