Make squashing work with subpixel layout

Source/core/rendering/compositing/RenderLayerCompositor.cpp

 /*
  * Copyright (C) 2009, 2010 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 630 matching lines @@
     // If a fixed position layer gained/lost a compositedLayerMapping or the reason not compositing it changed,
     // the scrolling coordinator needs to recalculate whether it can do fast scrolling.
     if (compositedLayerMappingChanged || nonCompositedReasonChanged) {
         if (ScrollingCoordinator* scrollingCoordinator = this->scrollingCoordinator())
             scrollingCoordinator->frameViewFixedObjectsDidChange(m_renderView.frameView());
     }
 
     return compositedLayerMappingChanged || nonCompositedReasonChanged;
 }
 
-static IntPoint computeOffsetFromAbsolute(RenderLayer* layer)
+static LayoutPoint computeOffsetFromAbsolute(RenderLayer* layer)
 {
     TransformState transformState(TransformState::ApplyTransformDirection, FloatPoint());
     layer->renderer()->mapLocalToContainer(0, transformState, ApplyContainerFlip);
     transformState.flatten();
-    return roundedIntPoint(transformState.lastPlanarPoint());
+    return LayoutPoint(transformState.lastPlanarPoint());
 }
 
 bool RenderLayerCompositor::updateSquashingAssignment(RenderLayer* layer, SquashingState& squashingState, const CompositingStateTransitionType compositedLayerUpdate)
 {
 
     // NOTE: In the future as we generalize this, the background of this layer may need to be assigned to a different backing than
     // the squashed RenderLayer's own primary contents. This would happen when we have a composited negative z-index element that needs
     // to paint on top of the background, but below the layer's main contents. For now, because we always composite layers
     // when they have a composited negative z-index child, such layers will never need squashing so it is not yet an issue.
     if (compositedLayerUpdate == PutInSquashingLayer) {
         // A layer that is squashed with other layers cannot have its own CompositedLayerMapping.
         ASSERT(!layer->hasCompositedLayerMapping());
         ASSERT(squashingState.hasMostRecentMapping);
 
-        IntPoint offsetFromAbsoluteForSquashedLayer = computeOffsetFromAbsolute(layer);
+        LayoutPoint offsetFromAbsoluteForSquashedLayer = computeOffsetFromAbsolute(layer);
 
-        IntSize offsetFromSquashingCLM(offsetFromAbsoluteForSquashedLayer.x() - squashingState.offsetFromAbsoluteForSquashingCLM.x(),
+        LayoutSize offsetFromSquashingCLM(offsetFromAbsoluteForSquashedLayer.x() - squashingState.offsetFromAbsoluteForSquashingCLM.x(),
             offsetFromAbsoluteForSquashedLayer.y() - squashingState.offsetFromAbsoluteForSquashingCLM.y());
 
         bool changedSquashingLayer =
             squashingState.mostRecentMapping->updateSquashingLayerAssignment(layer, offsetFromSquashingCLM, squashingState.nextSquashedLayerIndex);
         squashingState.nextSquashedLayerIndex++;
 
         if (!changedSquashingLayer)
             return true;
 
         layer->clipper().clearClipRectsIncludingDescendants();
@@ skipping 449 matching lines @@
 
     if (!willBeCompositedOrSquashed && layer->parent())
         layer->parent()->setHasNonCompositedChild(true);
 
     descendantHas3DTransform |= anyDescendantHas3DTransform || layer->has3DTransform();
 
     if (overlapMap)
         overlapMap->geometryMap().popMappingsToAncestor(ancestorLayer);
 }
 
-void RenderLayerCompositor::SquashingState::updateSquashingStateForNewMapping(CompositedLayerMappingPtr newCompositedLayerMapping, bool hasNewCompositedLayerMapping, IntPoint newOffsetFromAbsoluteForSquashingCLM, RenderLayer* newClippingAncestorForMostRecentMapping)
+void RenderLayerCompositor::SquashingState::updateSquashingStateForNewMapping(CompositedLayerMappingPtr newCompositedLayerMapping, bool hasNewCompositedLayerMapping, LayoutPoint newOffsetFromAbsoluteForSquashingCLM, RenderLayer* newClippingAncestorForMostRecentMapping)
 {
     // The most recent backing is done accumulating any more squashing layers.
     if (hasMostRecentMapping)
         mostRecentMapping->finishAccumulatingSquashingLayers(nextSquashedLayerIndex);
 
     nextSquashedLayerIndex = 0;
     mostRecentMapping = newCompositedLayerMapping;
     hasMostRecentMapping = hasNewCompositedLayerMapping;
     offsetFromAbsoluteForSquashingCLM = newOffsetFromAbsoluteForSquashingCLM;
     clippingAncestorForMostRecentMapping = newClippingAncestorForMostRecentMapping;
@@ skipping 46 matching lines @@
     if (layer->stackingNode()->isStackingContainer()) {
         RenderLayerStackingNodeIterator iterator(*layer->stackingNode(), NegativeZOrderChildren);
         while (RenderLayerStackingNode* curNode = iterator.next())
             assignLayersToBackingsInternal(curNode->layer(), squashingState, layersChanged, clippingAncestor);
     }
 
     if (layerSquashingEnabled()) {
         // At this point, if the layer is to be "separately" composited, then its backing becomes the most recent in paint-order.
         if (layer->compositingState() == PaintsIntoOwnBacking || layer->compositingState() == HasOwnBackingButPaintsIntoAncestor) {
             ASSERT(!requiresSquashing(layer->compositingReasons()));
-            IntPoint offsetFromAbsoluteForSquashingCLM = computeOffsetFromAbsolute(layer);
+            LayoutPoint offsetFromAbsoluteForSquashingCLM = computeOffsetFromAbsolute(layer);
             squashingState.updateSquashingStateForNewMapping(layer->compositedLayerMapping(), layer->hasCompositedLayerMapping(), offsetFromAbsoluteForSquashingCLM, clippingAncestor);
         }
     }
 
     RenderLayerStackingNodeIterator iterator(*layer->stackingNode(), NormalFlowChildren | PositiveZOrderChildren);
     while (RenderLayerStackingNode* curNode = iterator.next())
         assignLayersToBackingsInternal(curNode->layer(), squashingState, layersChanged, clippingAncestor);
 }
 
 void RenderLayerCompositor::setCompositingParent(RenderLayer* childLayer, RenderLayer* parentLayer)
@@ skipping 1022 matching lines @@
     } else if (graphicsLayer == m_scrollLayer.get()) {
         name = "LocalFrame Scrolling Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore