mix-blend-mode implementation for accelerated layers - blink part

Source/core/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 3883 matching lines @@
         // compositor, the compositing layer bounds need to change from including filter outsets to
         // excluding filter outsets, on platforms whose compositors compute their own outsets.
         // Similarly for the reverse change from compositor-painted to software-painted filters.
         return true;
     }
 #endif
 
     return false;
 }
 
+inline bool RenderLayer::needsCompositingLayersRebuiltForBlending(const RenderStyle* oldStyle, const RenderStyle* newStyle) const
+{
+    ASSERT(newStyle);
+    if (!hasCompositedLayerMapping())
+        return false;
+    return (shouldIsolateCompositedDescendants() && !stackingNode()->isStackingContext())
+        || (oldStyle && (oldStyle->hasBlendMode() != newStyle->hasBlendMode()));
+}
+
 void RenderLayer::updateFilters(const RenderStyle* oldStyle, const RenderStyle* newStyle)
 {
     if (!hasOrHadFilters(oldStyle, newStyle))
         return;
 
     updateOrRemoveFilterClients();
     // During an accelerated animation, both WebKit and the compositor animate properties.
     // However, WebKit shouldn't ask the compositor to update its filters if the compositor is performing the animation.
     if (hasCompositedLayerMapping() && (RuntimeEnabledFeatures::webAnimationsCSSEnabled()
         ? !hasActiveAnimationsOnCompositor(*renderer(), CSSPropertyWebkitFilter)
@@ skipping 26 matching lines @@
     bool didPaintWithFilters = false;
 
     if (paintsWithFilters())
         didPaintWithFilters = true;
     updateFilters(oldStyle, renderer()->style());
 
     const RenderStyle* newStyle = renderer()->style();
     if (compositor()->updateLayerCompositingState(this)
         || needsCompositingLayersRebuiltForClip(oldStyle, newStyle)
         || needsCompositingLayersRebuiltForOverflow(oldStyle, newStyle)
-        || needsCompositingLayersRebuiltForFilters(oldStyle, newStyle, didPaintWithFilters))
+        || needsCompositingLayersRebuiltForFilters(oldStyle, newStyle, didPaintWithFilters)
+        || needsCompositingLayersRebuiltForBlending(oldStyle, newStyle))

[rosca, 2013/11/25 21:11:41]

I added this new check. The tree must be rebuilt if blending is turned on/off or
if the isolating stacking context doesn't need to be stacking context any
longer.
Added a new LayoutTest for this as well.

         compositor()->setCompositingLayersNeedRebuild();
     else if (hasCompositedLayerMapping())
         compositedLayerMapping()->updateGraphicsLayerGeometry();
 }
 
 bool RenderLayer::scrollsOverflow() const
 {
     if (RenderLayerScrollableArea* scrollableArea = this->scrollableArea())
         return scrollableArea->scrollsOverflow();
 
@@ skipping 159 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif