Bug 218016 - Accelerated animations should use the same start time as software animations
Summary: Accelerated animations should use the same start time as software animations
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: Animations (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Nobody
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2020-10-21 05:45 PDT by Antoine Quint
Modified: 2020-10-21 05:50 PDT (History)
3 users (show)

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Description Antoine Quint 2020-10-21 05:45:03 PDT 
Right now accelerated animations share a start time for a given transaction, and software animations share a start time for a given rendering update, but there's no guarantee that those shared start times are the same for accelerated and software animations started as a result of the same rendering update.
Comment 1 Radar WebKit Bug Importer 2020-10-21 05:45:28 PDT 
<rdar://problem/70526060>
Comment 2 Antoine Quint 2020-10-21 05:48:00 PDT 
One way to fix this would be to use the time used by accelerated animations as obtained through GraphicsLayerCA::platformCALayerAnimationStarted() and feed that back to the software animations.
Comment 3 Antoine Quint 2020-10-21 05:50:44 PDT 
We should also consider not using the animation begin time to bake the time offset in, and instead use nested animations with groups to use the timeOffset property of the CA animation. This way we won't need to hard set a beginTime for animations with an offset in GraphicsLayerCA::updateAnimations().