Bug 50800

Summary: Font flicker issues on hover transition.
Product: WebKit Reporter: Pete Milkman <pmilkman>
Component: CSSAssignee: Nobody <webkit-unassigned>
Status: UNCONFIRMED ---    
Severity: Normal CC: jonlee, mitz, mmaxfield, otherleek, simon.fraser
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Macintosh Intel   
OS: OS X 10.6   
URL: http://www.petemilkman.com/css3-2d-pg.php
See Also: https://bugs.webkit.org/show_bug.cgi?id=23364
Description Flags
Here's another case of this phenomenon. none

Description Pete Milkman 2010-12-09 20:56:59 PST
If you hover over one of the squares in the grid, you'll notice the text in the grid squares after it in the grid get lighter during the transition, and then return to normal when the transition is complete. 

- It only happens to the squares after the one you hover over.
- Happens during the transition but not before or after.
- Doesn't happen in Chrome, FF4 or Opera.
- The 'lightening' of the text happens immediately and reverts immediately (not a smooth transition).
- The 'lightening' problem was not intended in the code at all.
Comment 1 Pete Milkman 2010-12-09 21:02:41 PST
This also occurs in Safari 5.
Comment 2 mitz 2010-12-10 00:05:55 PST
The squares go in and out of compositing mode, and when subpixel antialiasing is on (which is the default on Mac OS X), text rendering in composited layers is different. A workaround would be to permanently disable subpixel antialiasing on the page, using "-webkit-font-smoothing: antialiased;".

There may already be bugs in the database covering the issues seen in this case.
Comment 3 Simon Fraser (smfr) 2010-12-10 08:34:24 PST
Related to bug 23364.
Comment 4 Pete Milkman 2011-02-25 19:37:59 PST
23364 has been closed, but this is stil happening in the latest nightly.
Comment 5 Joshua Merrill 2011-08-02 13:18:44 PDT
Created attachment 102691 [details]
Here's another case of this phenomenon.
Comment 6 Klim Lee 2015-06-21 22:41:10 PDT
It’s 2015, and the issue is still there.
Comment 7 Myles C. Maxfield 2015-07-09 20:41:39 PDT
Seems likely this is due to compositing layers.
Comment 8 Myles C. Maxfield 2015-07-09 20:42:08 PDT
Ah, I didn't read what Mitz said. Yep.