Bug 242183

Summary:	Janky motion path animation in STP 148 / MacBook Pro with ProMotion
Product:	WebKit	Reporter:	Kiet Ho <kiet.ho>
Component:	Animations	Assignee:	Nikos Mouchtaris <nmouchtaris>
Status:	NEW ---
Severity:	Normal	CC:	dino, graouts, graouts, kiet.ho, simon.fraser, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	Safari Technology Preview
Hardware:	Mac (Apple Silicon)
OS:	Unspecified
URL:	https://codepen.io/team/css-tricks/pen/zEpLpK
Bug Depends on:
Bug Blocks:	203847

Description Kiet Ho 2022-06-30 06:01:45 PDT

Bug is reported here https://github.com/WebKit/WebKit/pull/806#issuecomment-1170759817. 

Animation is very janky on a MacBook Pro with M1 Max and ProMotion. The animation becomes even more janky when ProMotion is turned off and the refresh rate is set to 60hz fixed. Issue doesn't occur on WebKit 614.1.19 on a M1 MacBook Pro (no ProMotion, fixed 60hz refresh rate), so I believe this has something to do with the variable refresh rate.

Comment 1 Radar WebKit Bug Importer 2022-06-30 08:46:12 PDT

<rdar://problem/96221664>

Comment 2 Simon Fraser (smfr) 2022-06-30 10:31:43 PDT

Offset path animations aren't yet implemented in the compositor, so run on the main thread and should run at 60Hz (but still look smooth). I ran the test on a ProMotion MacBook Pro and it looked smooth.

Comment 3 Kiet Ho 2022-06-30 10:38:24 PDT

I borrowed a MBP with ProMotion too and it looks pretty alright (not 120fps smooth but not as bad as the one in the Github issue)

Comment 4 Alexey Proskuryakov 2022-06-30 11:33:53 PDT

*** Bug 242182 has been marked as a duplicate of this bug. ***