Bug 265362 - Element flickers when transitioning boxShadow with large spread value
Summary: Element flickers when transitioning boxShadow with large spread value
Status: RESOLVED MOVED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: Safari 17
Hardware: Mac (Apple Silicon) macOS 14
: P2 Normal
Assignee: Nobody
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2023-11-26 22:15 PST by Ethan Wong
Modified: 2023-12-21 15:07 PST (History)
6 users (show)

See Also:

Attachments
a page to reproduce the flickering issue (724 bytes, text/html)
2023-11-26 22:15 PST, Ethan Wong 		no flags Details
screen recording for the flickering issue (5.07 MB, video/quicktime)
2023-11-26 22:15 PST, Ethan Wong 		no flags Details
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Description Ethan Wong 2023-11-26 22:15:00 PST 
Created attachment 468761 [details]
a page to reproduce the flickering issue

Element flickers when transitioning `box-shadow` with a large spread value, see the attached html file and screen recording.

This issue happens when the element has non-zero `border-radius` and non-integer `margin`s.

It happens only on macOS 14.

Force using using `PathRoundedRect::Strategy::PreferBezier` for `PathCG::addRoundedRect(const FloatRoundedRect&, PathRoundedRect::Strategy)` seems to work around this issue.
Comment 1 Ethan Wong 2023-11-26 22:15:34 PST 
Created attachment 468762 [details]
screen recording for the flickering issue
Comment 2 Radar WebKit Bug Importer 2023-11-27 10:35:27 PST 
<rdar://problem/118840547>
Comment 3 Simon Fraser (smfr) 2023-11-27 10:36:46 PST 
Thanks for the report. This is a bug in a system component below webkit.
Comment 4 Brent Fulgham 2023-12-21 15:07:06 PST 
The actual work for this fix was done under <rdar://118793261>.