Review follow-up. "A GPU device exists" does not mean the GPU draws the
view: soft proofs and the HDR range render on the CPU, and a LUT profile,
refined masks or a photo past a GPU limit fall back per render. Those drags
had become full-size CPU renders.
region::DragScale now picks the draft size when a drag starts and keeps it
until the drag ends (no resolution jump mid-gesture): full size where the
GPU draws the view (not soft-proofed, no HDR range) and no earlier drag of
the same control on this photo went over the 16 ms slider budget at full
size; 0.6 otherwise. Full-size drafts are timed as they land (the first,
rebuilding stage caches, is left out; the median decides).
ViewSizes carries one `draft: Option<f32>` instead of a scale and a flag
that could disagree. Tests: DragScale unit tests (budget, lock, hostile
times) and headless drags for a remembered slow drag and a soft-proofed
drag, each checked to fail without its guard.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
