RESOLVED FIXED324156
[Win] steps() animations are incorrectly accelerated after 320878@main 
https://bugs.webkit.org/show_bug.cgi?id=324156
Summary [Win] steps() animations are incorrectly accelerated after 320878@main
johnjamesjacoby
Reported 2026-09-14 09:32:27 PDT
320878@main changed KeyframeEffect::canBeAccelerated() so the steps() and linear()-with-points restrictions only apply when USE(CA). This unintentionally enables acceleration for the USE(GRAPHICS_LAYER_WC) backend, although the change and its supporting TextureMapperAnimation work were intended for GTK and WPE. Windows EWS runs based on 320876@main do not fail animations/steps-transform-rendering-updates.html: https://ews-build.webkit.org/#/builders/60/builds/100823 The failure appears consistently in runs based on 320880@main and later: https://ews-build.webkit.org/#/builders/60/builds/100825 The original change is: https://commits.webkit.org/320878@main The proposed fix retains these restrictions for USE(CA) || USE(GRAPHICS_LAYER_WC), preserving the intended GTK/WPE behavior.
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Radar WebKit Bug Importer
Comment 1 2026-09-21 09:33:13 PDT
<rdar://problem/187995435>
johnjamesjacoby
Comment 2 2026-09-21 14:01:50 PDT
Proposed fix: https://github.com/WebKit/WebKit/pull/73966
EWS
Comment 3 2026-09-24 09:50:35 PDT
Committed 321799@main (32f5f3ff4c19): <https://commits.webkit.org/321799@main> Reviewed commits have been landed. Closing PR #73966 and removing active labels.
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