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

Source/core/rendering/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 199 matching lines @@
     if (m_isMainFrameRenderViewLayer)
         m_graphicsLayer->contentLayer()->setDrawCheckerboardForMissingTiles(true);
 #endif
 
     updateOpacity(renderer()->style());
     updateTransform(renderer()->style());
     updateFilters(renderer()->style());
 
     if (RuntimeEnabledFeatures::cssCompositingEnabled())
         updateLayerBlendMode(renderer()->style());
+    if (RuntimeEnabledFeatures::cssCompositingEnabled())

[enne (OOO), 2013/11/07 22:59:07]

Put these under the same conditional.

[rosca, 2013/11/08 15:36:32]

Done.

+        updateIsRootForIsolatedGroup();
 }
 
 void CompositedLayerMapping::destroyGraphicsLayers()
 {
     if (m_graphicsLayer)
         m_graphicsLayer->removeFromParent();
 
     m_ancestorClippingLayer = nullptr;
     m_graphicsLayer = nullptr;
     m_foregroundLayer = nullptr;
@@ skipping 36 matching lines @@
         //
         // Similarly, if filters used to be painted in the compositor and are now painted in software, we need to:
         // (1) Create a FilterEffectRenderer.
         // (2) Repaint the layer contents to apply a software filter because the compositor won't apply it.
         //
         m_owningLayer->updateOrRemoveFilterEffectRenderer();
         setContentsNeedDisplay();
     }
 }
 
-void CompositedLayerMapping::updateLayerBlendMode(const RenderStyle*)
+void CompositedLayerMapping::updateLayerBlendMode(const RenderStyle* style)
 {
+    setBlendMode(style->blendMode());
+}
+
+void CompositedLayerMapping::updateIsRootForIsolatedGroup()
+{
+    m_graphicsLayer->setIsRootForIsolatedGroup(m_owningLayer->hasCompositedBlendingDescendants()

[enne (OOO), 2013/11/07 22:59:07]

Whoa there.  If you have a tree of RenderLayers creating stacking contexts with
a blending child at the bottom, then all of them will be set as roots for
isolated groups and needlessly become composited layers?  And therefore also in
Chromium all of them will needlessly become render surfaces?

[rosca, 2013/11/08 15:36:32]

No. hasCompositedBlendingDescendants is true only if the layer has a descendant
in the current stacking context, descendants that are enclosed in a descendant
stacking contexts are not taken into account.
I agree that the function name doesn't suggest the same thing. I renamed it to
requiresIsolationForCompositedStackingContext. It will be set to true for all
the layers nodes between the blending layer up to its stacking context layer.
Only the stacking contexts having this flag set will request an isolated group.

+        && m_owningLayer->stackingNode()->isStackingContext());
 }
 
 void CompositedLayerMapping::updateContentsOpaque()
 {
     // For non-root layers, background is always painted by the primary graphics layer.
     ASSERT(m_isMainFrameRenderViewLayer || !m_backgroundLayer);
     if (m_backgroundLayer) {
         m_graphicsLayer->setContentsOpaque(false);
         m_backgroundLayer->setContentsOpaque(m_owningLayer->backgroundIsKnownToBeOpaqueInRect(compositedBounds()));
     } else {
@@ skipping 226 matching lines @@
     // is affected by the layer dimensions.
     if (!renderer()->animation().isRunningAcceleratedAnimationOnRenderer(renderer(), CSSPropertyWebkitTransform))
         updateTransform(renderer()->style());
 
     // Set opacity, if it is not animating.
     if (!renderer()->animation().isRunningAcceleratedAnimationOnRenderer(renderer(), CSSPropertyOpacity))
         updateOpacity(renderer()->style());
 
     if (RuntimeEnabledFeatures::cssCompositingEnabled())
         updateLayerBlendMode(renderer()->style());
+    if (RuntimeEnabledFeatures::cssCompositingEnabled())
+        updateIsRootForIsolatedGroup();
 
     bool isSimpleContainer = isSimpleContainerCompositingLayer();
 
     m_owningLayer->updateDescendantDependentFlags();
 
     // m_graphicsLayer is the corresponding GraphicsLayer for this RenderLayer and its non-compositing
     // descendants. So, the visibility flag for m_graphicsLayer should be true if there are any
     // non-compositing visible layers.
     bool contentsVisible = m_owningLayer->hasVisibleContent() || hasVisibleNonCompositingDescendantLayers();
     if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled() && renderer()->isVideo()) {
@@ skipping 1011 matching lines @@
     m_requiresOwnBackingStore = requiresOwnBacking;
 
     // This affects the answer to paintsIntoCompositedAncestor(), which in turn affects
     // cached clip rects, so when it changes we have to clear clip rects on descendants.
     m_owningLayer->clipper().clearClipRectsIncludingDescendants(PaintingClipRects);
     m_owningLayer->repainter().computeRepaintRectsIncludingDescendants();
 
     compositor()->repaintInCompositedAncestor(m_owningLayer, compositedBounds());
 }
 
-void CompositedLayerMapping::setBlendMode(BlendMode)
+void CompositedLayerMapping::setBlendMode(BlendMode blendMode)
 {
+    if (m_ancestorClippingLayer) {
+        ASSERT(childForSuperlayers() == m_ancestorClippingLayer.get());
+        m_graphicsLayer->setBlendMode(BlendModeNormal);
+    } else {
+        ASSERT(childForSuperlayers() == m_graphicsLayer.get());
+    }
+    childForSuperlayers()->setBlendMode(blendMode);
 }
 
 void CompositedLayerMapping::setContentsNeedDisplay()
 {
     ASSERT(!paintsIntoCompositedAncestor());
 
     if (m_graphicsLayer && m_graphicsLayer->drawsContent())
         m_graphicsLayer->setNeedsDisplay();
 
     if (m_foregroundLayer && m_foregroundLayer->drawsContent())
@@ skipping 402 matching lines @@
     } else if (graphicsLayer == m_scrollingContentsLayer.get()) {
         name = "Scrolling Contents Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore