Bug 58397

Summary: [chromium] Descendants of layers whose parent preserves-3d don't always render in DOM order
Product: WebKit Reporter: Vangelis Kokkevis <vangelis>
Component: WebCore Misc.Assignee: Vangelis Kokkevis <vangelis>
Status: RESOLVED FIXED    
Severity: Normal CC: commit-queue, jamesr
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: PC   
OS: OS X 10.5   
Attachments:
Description Flags
Patch none

Vangelis Kokkevis
Reported 2011-04-12 17:10:14 PDT
The chromium compositor sorts all descendants of a layer that sets the preserves-3d property based on the layer center's z coordinate. The algorithm relies on the properties of stable sort to keep layers with the same z coordinate render with their correct DOM order. The z coordinate of layers whose parent doesn't preserve 3d are set to the z coordinate of their parent. Due to a bug in the code, we grab the z coordinate of the parent layer before it's actually set so as things animate, child layers use the z coordinate of their parent from the previous frame, messing up the sorting order.
Attachments
Patch (12.15 KB, patch)
2011-04-12 17:40 PDT, Vangelis Kokkevis 		no flags
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Vangelis Kokkevis
Comment 1 2011-04-12 17:40:05 PDT
Created attachment 89319 [details] Patch
Vangelis Kokkevis
Comment 2 2011-04-12 17:41:57 PDT
I should probably mention that I put the layout test under platform/chromium as it's really a regression test for a bug found in chrome. Not worth adding to the common test pool...
James Robinson
Comment 3 2011-04-12 17:55:42 PDT
Comment on attachment 89319 [details] Patch Good catch!
WebKit Commit Bot
Comment 4 2011-04-12 21:13:53 PDT
Comment on attachment 89319 [details] Patch Clearing flags on attachment: 89319 Committed r83694: <http://trac.webkit.org/changeset/83694>
WebKit Commit Bot
Comment 5 2011-04-12 21:14:00 PDT
All reviewed patches have been landed. Closing bug.
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