Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: f34545487d2f0ae366253ef8daab7088a3e830fc
https://github.com/WebKit/WebKit/commit/f34545487d2f0ae366253ef8daab7088a3e830fc
Author: Antoine Quint <[email protected]>
Date: 2026-05-20 (Wed, 20 May 2026)
Changed paths:
M Source/WebKit/UIProcess/RemoteLayerTree/RemoteAnimationStack.h
M Source/WebKit/UIProcess/RemoteLayerTree/RemoteAnimationStack.mm
M
Source/WebKit/UIProcess/RemoteLayerTree/ios/RemoteScrollingCoordinatorProxyIOS.mm
M
Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteLayerTreeEventDispatcher.h
M
Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteLayerTreeEventDispatcher.mm
Log Message:
-----------
[threaded-animations] stuttery animation on bmwusa.com configurator page with
60Hz display
https://bugs.webkit.org/show_bug.cgi?id=315209
rdar://176420489
Reviewed by Simon Fraser.
On macOS, an animation update is triggered both when a display refresh occurs
on the
scrolling thread, somewhere under
`RemoteLayerTreeEventDispatcher::didRefreshDisplay()`,
and when a page rendering update has completed on the main thread, in
`RemoteLayerTreeEventDispatcher::renderingUpdateComplete()`.
The latter call was added in 303810@main to ensure that programmatic scrolls
would
correctly update progress-based animations. However, this has the undesired
effects
that when the page rendering is updated, all animations, including those
contained
in animation stacks that only contain time-based animations, are updated twice.
In the case of a Pro Motion display, typically this would mean that we update
animations
twice every other frame, since page rendering updates still occur near 60Hz by
default.
But on a display set to refresh at 60Hz, the issue is made worse since we end up
updating animations twice on every frame.
To address this, at least for the case where only time-based animations are
used (the
vast majority of cases at this currently), we no longer update animation stacks
that
only contain time-based animations when
`RemoteLayerTreeEventDispatcher::renderingUpdateComplete()`
is called. We do so by adding a new enum argument to `updateAnimations()` and
only
advance monotonic timelines and update animation stacks containing time-based
animations
if the argument indicates that all animation stacks should be updated, as
opposed to those
containing at least one progress-based animation.
* Source/WebKit/UIProcess/RemoteLayerTree/RemoteAnimationStack.h:
* Source/WebKit/UIProcess/RemoteLayerTree/RemoteAnimationStack.mm:
(WebKit::RemoteAnimationStack::RemoteAnimationStack):
(WebKit::RemoteAnimationStack::isTimeDependent const): Deleted.
*
Source/WebKit/UIProcess/RemoteLayerTree/ios/RemoteScrollingCoordinatorProxyIOS.mm:
(WebKit::RemoteScrollingCoordinatorProxyIOS::updateTimeDependentAnimationStacks):
* Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteLayerTreeEventDispatcher.h:
* Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteLayerTreeEventDispatcher.mm:
(WebKit::RemoteLayerTreeEventDispatcher::renderingUpdateComplete):
(WebKit::RemoteLayerTreeEventDispatcher::updateAnimations):
Canonical link: https://commits.webkit.org/313647@main
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