David Mann 5781847da3 Paint: Lock Transparency blends source-atop on semi-transparent pixels (#5783) ...

With alpha kept (Lock Transparent Pixels, Fill's Preserve Transparency),
the brush, mixer, Fill, Gradient and Paint Bucket composited source-over
and then restored the old alpha, so a half-transparent pixel took the new
colour by as / ao instead of as. They now blend source-atop, as Photoshop
does: Co = (1-as)*Cb + as*B(Cb,Cs), alpha unchanged. New shared helper
blend::composite_atop; over_native's lock branch lerps by the source alpha.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

2026-10-14 23:15:43 +02:00

..

src

Paint: Lock Transparency blends source-atop on semi-transparent pixels (#5783)

2026-10-14 23:15:43 +02:00

Cargo.toml

more algorithms, progress

2026-10-01 08:25:06 -04:00