Changeset 249120 in webkit

Timestamp:

Aug 26, 2019, 3:21:38 PM (7 years ago)

Author:

Simon Fraser

Message:

Optimize computation of AbsoluteClipRects clip rects
​https://bugs.webkit.org/show_bug.cgi?id=201148

Reviewed by Zalan Bujtas.

When adding layers to the compositing overlap map, we compute AbsoluteClipRects for every
layer which is expensive. This was more expensive than necessary because we converted them
to TemporaryClipRects when crossing painting boundaries, but AbsoluteClipRects don't
care about painting boundaries, so don't do this.

• rendering/RenderLayer.cpp:

(WebCore::RenderLayer::calculateClipRects const):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/RenderLayer.cpp (modified) (2 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-08-26  Simon Fraser  <simon.fraser@apple.com>
+
+        Optimize computation of AbsoluteClipRects clip rects
+        https://bugs.webkit.org/show_bug.cgi?id=201148
+
+        Reviewed by Zalan Bujtas.
+
+        When adding layers to the compositing overlap map, we compute AbsoluteClipRects for every
+        layer which is expensive. This was more expensive than necessary because we converted them
+        to TemporaryClipRects when crossing painting boundaries, but AbsoluteClipRects don't
+        care about painting boundaries, so don't do this.
+
+        * rendering/RenderLayer.cpp:
+        (WebCore::RenderLayer::calculateClipRects const):
+
 2019-08-26  Chris Dumez  <cdumez@apple.com>
 

trunk/Source/WebCore/rendering/RenderLayer.cpp

@@ -5632 +5632 @@
             parentContext.overlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize; // FIXME: why?
             
-            if (parentContext.clipRectsType != TemporaryClipRects && clipCrossesPaintingBoundary())
+            if ((parentContext.clipRectsType != TemporaryClipRects && parentContext.clipRectsType != AbsoluteClipRects) && clipCrossesPaintingBoundary())
                 parentContext.clipRectsType = TemporaryClipRects;
 
@@ -5698 +5698 @@
         return temporaryParentClipRects(clipRectsContext);
 
-    if (clipCrossesPaintingBoundary()) {
+    if (clipRectsContext.clipRectsType != AbsoluteClipRects && clipCrossesPaintingBoundary()) {
         ClipRectsContext tempClipRectsContext(clipRectsContext);
         tempClipRectsContext.clipRectsType = TemporaryClipRects;