[Webkit-unassigned] [Bug 186129] REGRESSION (r232186): Hardware-accelerated CSS animations using steps() timing function no longer work

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=186129

--- Comment #11 from Frédéric Wang (:fredw) <fred.wang at free.fr> ---
(In reply to Frédéric Wang (:fredw) from comment #9)
> (In reply to Antoine Quint from comment #8)
> > Animating margin-left instead of transform behaves as expected. This is an
> > issue with hardware-accelerated animations only.
> 
> Also, note that GraphicsLayerCA::animationCanBeAccelerated returns false for
> the steps() timing function (which is the case failing in the attached
> testcase). So maybe the implementation with webAnimationCSSIntegration
> enabled does not handle transform for non-accelerated animations?

Comparing the stack traces, webAnimationCSSIntegration disabled gives:

WebCore::GraphicsLayerCA::animationCanBeAccelerated
WebCore::GraphicsLayerCA::addAnimation
WebCore::RenderLayerBacking::startAnimation
WebCore::RenderBoxModelObject::startAnimation
WebCore::KeyframeAnimation::startAnimation
WebCore::AnimationBase::updateStateMachine
...

while webAnimationCSSIntegration enabled gives:

WebCore::GraphicsLayerCA::animationCanBeAccelerated
WebCore::GraphicsLayerCA::addAnimation
WebCore::RenderLayerBacking::startAnimation
WebCore::RenderBoxModelObject::startAnimation
WebCore::KeyframeEffectReadOnly::applyPendingAcceleratedActions
WebCore::WebAnimation::applyPendingAcceleratedActions
...

Note that in the former case, the AnimationBase becomes non-accelerated when startAnimation returns false (e.g. when animationCanBeAccelerated returns false) but in the latter case, the WebAnimation just ignores the boolean returned by startAnimation. It looks like it should somewhat fallback to non-accelerated mode too.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20180618/e94c3881/attachment-0001.html>