Bug 63493

Summary:

Overlap map for compositing needs to consider clipping

Product:

WebKit

Reporter:

Adrienne Walker <enne>

Component:

WebCore Misc.

Assignee:

Adrienne Walker <enne>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

enne, jamesr, simon.fraser, vangelis

Priority:

Version:

528+ (Nightly build)

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
Test case	none
Patch	simon.fraser: review+

Adrienne Walker

Reported 2011-06-27 16:38:20 PDT

The overlap map in RenderLayerCompositor currently doesn't consider clipping. So, if there is a large layer that is clipped, it may cause other layers to unnecessarily become composited, even though they aren't truly overlapping once clip is considered. See: http://crbug.com/85438

Attachments
Test case (1.37 KB, text/html) 2011-06-27 16:57 PDT, Adrienne Walker	no flags	Details
Patch (14.17 KB, patch) 2011-06-27 17:49 PDT, Adrienne Walker	simon.fraser: review+	Details Formatted Diff Diff
View All Add attachment proposed patch, testcase, etc.

Simon Fraser (smfr)

Comment 1 2011-06-27 16:52:45 PDT

I can haz testcase?

Adrienne Walker

Comment 2 2011-06-27 16:57:37 PDT

Created attachment 98815 [details] Test case Here's a test case. I have a patch too, but it changes the expected output from limit-layer-bounds-clipping-ancestor, so I need to clean that up first.

Adrienne Walker

Comment 3 2011-06-27 17:49:06 PDT

Created attachment 98830 [details] Patch

Adrienne Walker

Comment 4 2011-07-13 15:55:19 PDT

(In reply to comment #3) > Created an attachment (id=98830) [details] > Patch smfr: ping?

Simon Fraser (smfr)

Comment 5 2011-07-13 16:07:33 PDT

Comment on attachment 98830 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=98830&action=review > Source/WebCore/rendering/RenderLayerCompositor.cpp:569 > + IntRect clipRect = layer->backgroundClipRect(rootRenderLayer(), true); This is another walk up the layer tree, sadly.

James Robinson

Comment 6 2011-07-13 16:10:11 PDT

That one should hit cache (saved m_clipRects on the parent layer) most of the time, at least.

Simon Fraser (smfr)

Comment 7 2011-07-13 16:20:04 PDT

(In reply to comment #6) > That one should hit cache (saved m_clipRects on the parent layer) most of the time, at least. No, temporaryClipRects = true.

Adrienne Walker

Comment 8 2011-07-15 14:54:34 PDT

Committed r91114: <http://trac.webkit.org/changeset/91114>

Simon Fraser (smfr)

Comment 9 2012-05-19 07:56:22 PDT

The perf hit from this was significant: bug 84410

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