radialmonsterandClaude Opus 5.5 1bfa617a5a GPU: black pixels take the colour tools and a light vignette as on the CPU ...

The GPU colour tools took the hue of every pixel with atan2(a, b). For a black pixel both are
0, and WGSL leaves atan2(0, 0) undefined: on an RTX 3090 (Vulkan) it is NaN, so with any
colour tool on (saturation, vibrance, the mixer) every exactly black pixel became NaN. NaN is
written as 0, so it stayed black and nothing showed, until a later step lightened it: with a
positive vignette the CPU lifts the black corners and the GPU left them black (up to 127
levels apart in 8-bit). A neutral pixel now gets hue 0, as Rust's atan2 gives on the CPU.

Regression test: black bars under a light vignette with saturation, vibrance or the mixer
(fails on main: mean 12.8, max 127 levels).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014ti8KemZbjE2ZgHgV1q1BM

2026-10-28 13:58:46 -04:00

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it

GPU: black pixels take the colour tools and a light vignette as on the CPU

2026-10-28 13:58:46 -04:00

memory.rs

feat(testkit): #1037 tests record why they skip

2026-10-11 16:33:54 -05:00

shutdown_first.rs

LR-BEHAV-GPU: no render is inside the GPU driver when the app quits (issue #620)

2026-10-10 00:46:24 -05:00

shutdown.rs

feat(testkit): #1037 tests record why they skip

2026-10-11 16:33:54 -05:00