Changeset 152212 in webkit

Timestamp:

Jun 29, 2013 1:19:43 PM (11 years ago)

Author:

Simon Fraser

Message:

Avoid doing work in RenderBox::outlineBoundsForRepaint() when the repaintContainer is this
​https://bugs.webkit.org/show_bug.cgi?id=118215

Reviewed by Tim Horton.

When the RenderGeometryMap code path was added, RenderBox::outlineBoundsForRepaint()
actually got slower if no coordinate mapping was needed. So avoid doing work when
we can, including avoiding the FloatQuad construction.

Speeds up scrolling overflow:scroll areas with large numbers of layer children.

• rendering/RenderBox.cpp:

(WebCore::RenderBox::outlineBoundsForRepaint):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/RenderBox.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-06-29  Simon Fraser  <simon.fraser@apple.com>
+
+        Avoid doing work in RenderBox::outlineBoundsForRepaint() when the repaintContainer is this
+        https://bugs.webkit.org/show_bug.cgi?id=118215
+
+        Reviewed by Tim Horton.
+
+        When the RenderGeometryMap code path was added, RenderBox::outlineBoundsForRepaint()
+        actually got slower if no coordinate mapping was needed. So avoid doing work when
+        we can, including avoiding the FloatQuad construction.
+        
+        Speeds up scrolling overflow:scroll areas with large numbers of layer children.
+
+        * rendering/RenderBox.cpp:
+        (WebCore::RenderBox::outlineBoundsForRepaint):
+
 2013-06-29  Kangil Han  <kangil.han@samsung.com>
 

trunk/Source/WebCore/rendering/RenderBox.cpp

@@ -538 +538 @@
     adjustRectForOutlineAndShadow(box);
 
-    FloatQuad containerRelativeQuad;
-    if (geometryMap)
-        containerRelativeQuad = geometryMap->mapToContainer(box, repaintContainer);
-    else
-        containerRelativeQuad = localToContainerQuad(FloatRect(box), repaintContainer);
-
-    box = containerRelativeQuad.enclosingBoundingBox();
-
+    if (repaintContainer != this) {
+        FloatQuad containerRelativeQuad;
+        if (geometryMap)
+            containerRelativeQuad = geometryMap->mapToContainer(box, repaintContainer);
+        else
+            containerRelativeQuad = localToContainerQuad(FloatRect(box), repaintContainer);
+
+        box = containerRelativeQuad.enclosingBoundingBox();
+    }
+    
     // FIXME: layoutDelta needs to be applied in parts before/after transforms and
     // repaint containers. https://bugs.webkit.org/show_bug.cgi?id=23308