Changeset 149969 in webkit

Timestamp:

May 12, 2013 11:46:37 AM (11 years ago)

Author:

Simon Fraser

Message:

Dropdowns on ​http://www.exploratorium.edu don't show anything
​https://bugs.webkit.org/show_bug.cgi?id=115991

Source/WebCore:

Reviewed by Dan Bernstein.

We can't optimize away the backing store of a layer by saying that
it paints into a composited ancestor if its composited bounds are not contained
by that ancestor.

Test: compositing/backing/no-backing-for-clip-overhang.html

• rendering/RenderLayerBacking.cpp:

(WebCore::RenderLayerBacking::updateGraphicsLayerGeometry): Pass in our
previously computed composited bounds relative to our composited ancestor,
and its composited bounds.

• rendering/RenderLayerCompositor.cpp:

(WebCore::RenderLayerCompositor::requiresOwnBackingStore): If the ancestor's
composited bounds don't contain the layer's composited bounds, the layer
needs its own backing store.

• rendering/RenderLayerCompositor.h:

LayoutTests:

Reviewed by Dan Bernstein.

Layer tree dump test with an overflow:hidden that projects outside its
ancestor, and is forced to composite by a composited child.

• compositing/backing/no-backing-for-clip-overhang-expected.txt: Added.
• compositing/backing/no-backing-for-clip-overhang.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/compositing/backing/no-backing-for-clip-overhang-expected.txt (added)
• LayoutTests/compositing/backing/no-backing-for-clip-overhang.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderLayerBacking.cpp (modified) (1 diff)
• Source/WebCore/rendering/RenderLayerCompositor.cpp (modified) (2 diffs)
• Source/WebCore/rendering/RenderLayerCompositor.h (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2013-05-12  Simon Fraser  <simon.fraser@apple.com>
+
+        Dropdowns on http://www.exploratorium.edu don't show anything
+        https://bugs.webkit.org/show_bug.cgi?id=115991
+
+        Reviewed by Dan Bernstein.
+        
+        Layer tree dump test with an overflow:hidden that projects outside its
+        ancestor, and is forced to composite by a composited child.
+
+        * compositing/backing/no-backing-for-clip-overhang-expected.txt: Added.
+        * compositing/backing/no-backing-for-clip-overhang.html: Added.
+
 2013-05-12  Andreas Kling  <akling@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-05-12  Simon Fraser  <simon.fraser@apple.com>
+
+        Dropdowns on http://www.exploratorium.edu don't show anything
+        https://bugs.webkit.org/show_bug.cgi?id=115991
+
+        Reviewed by Dan Bernstein.
+        
+        We can't optimize away the backing store of a layer by saying that
+        it paints into a composited ancestor if its composited bounds are not contained
+        by that ancestor.
+
+        Test: compositing/backing/no-backing-for-clip-overhang.html
+
+        * rendering/RenderLayerBacking.cpp:
+        (WebCore::RenderLayerBacking::updateGraphicsLayerGeometry): Pass in our 
+        previously computed composited bounds relative to our composited ancestor,
+        and its composited bounds.
+        * rendering/RenderLayerCompositor.cpp:
+        (WebCore::RenderLayerCompositor::requiresOwnBackingStore): If the ancestor's
+        composited bounds don't contain the layer's composited bounds, the layer
+        needs its own backing store.
+        * rendering/RenderLayerCompositor.h:
+
 2013-05-12  Commit Queue  <commit-queue@webkit.org>
 

trunk/Source/WebCore/rendering/RenderLayerBacking.cpp

@@ -859 +859 @@
 
     // If this layer was created just for clipping or to apply perspective, it doesn't need its own backing store.
-    setRequiresOwnBackingStore(compositor()->requiresOwnBackingStore(m_owningLayer, compAncestor));
+    setRequiresOwnBackingStore(compositor()->requiresOwnBackingStore(m_owningLayer, compAncestor, relativeCompositingBounds, ancestorCompositingBounds));
 
     bool didUpdateContentsRect = false;

trunk/Source/WebCore/rendering/RenderLayerCompositor.cpp

@@ -1752 +1752 @@
 }
 
-bool RenderLayerCompositor::requiresOwnBackingStore(const RenderLayer* layer, const RenderLayer* compositingAncestorLayer) const
+bool RenderLayerCompositor::requiresOwnBackingStore(const RenderLayer* layer, const RenderLayer* compositingAncestorLayer, const IntRect& layerCompositedBoundsInAncestor, const IntRect& ancestorCompositedBounds) const
 {
     RenderObject* renderer = layer->renderer();
@@ -1788 +1788 @@
             || reason == RenderLayer::IndirectCompositingForPreserve3D; // preserve-3d has to create backing store to ensure that 3d-transformed elements intersect.
     }
+
+    if (!ancestorCompositedBounds.contains(layerCompositedBoundsInAncestor))
+        return true;
+
     return false;
 }

trunk/Source/WebCore/rendering/RenderLayerCompositor.h

@@ -180 +180 @@
 
     // Returns true if the given layer needs it own backing store.
-    bool requiresOwnBackingStore(const RenderLayer*, const RenderLayer* compositingAncestorLayer) const;
+    bool requiresOwnBackingStore(const RenderLayer*, const RenderLayer* compositingAncestorLayer, const IntRect& layerCompositedBoundsInAncestor, const IntRect& ancestorCompositedBounds) const;
 
     RenderLayer* rootRenderLayer() const;