Remove updatePaintingInfoForFragments() and per-fragment shouldPaintContent flag.

Source/core/paint/LayerPainter.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/paint/LayerPainter.h"
 
 #include "core/frame/Settings.h"
 #include "core/page/Page.h"
 #include "core/rendering/ClipPathOperation.h"
@@ skipping 239 matching lines @@
     bool createTransparencyLayerForBlendMode = !m_renderLayer.renderer()->isDocumentElement() && m_renderLayer.stackingNode()->isStackingContext() && m_renderLayer.hasNonIsolatedDescendantWithBlendMode();
 
     if (createTransparencyLayerForBlendMode)
         beginTransparencyLayers(context, paintingInfo.rootLayer, paintingInfo.paintDirtyRect, paintingInfo.subPixelAccumulation, paintingInfo.paintBehavior);
 
     LayerPaintingInfo localPaintingInfo(paintingInfo);
     bool haveFilterEffect = m_renderLayer.filterRenderer() && m_renderLayer.paintsWithFilters();
 
     LayerFragments layerFragments;
     if (shouldPaintContent || shouldPaintOutline || isPaintingOverlayScrollbars) {
-        // Collect the fragments. This will compute the clip rectangles and paint offsets for each layer fragment, as well as whether or not the content of each
-        // fragment should paint.
+        // Collect the fragments. This will compute the clip rectangles and paint offsets for each layer fragment.
         m_renderLayer.collectFragments(layerFragments, localPaintingInfo.rootLayer, localPaintingInfo.paintDirtyRect,
             (paintFlags & PaintLayerUncachedClipRects) ? UncachedClipRects : PaintingClipRects, IgnoreOverlayScrollbarSize,
             shouldRespectOverflowClip(paintFlags, m_renderLayer.renderer()), &offsetFromRoot, localPaintingInfo.subPixelAccumulation);
-        updatePaintingInfoForFragments(layerFragments, localPaintingInfo, paintFlags, shouldPaintContent, &offsetFromRoot);
+        if (shouldPaintContent)
+            shouldPaintContent = atLeastOneFragmentIntersectsDamageRect(layerFragments, localPaintingInfo, paintFlags, offsetFromRoot);
     }
 
     bool selectionOnly  = localPaintingInfo.paintBehavior & PaintBehaviorSelectionOnly;
     // If this layer's renderer is a child of the paintingRoot, we render unconditionally, which
     // is done by passing a nil paintingRoot down to our renderer (as if no paintingRoot was ever set).
     // Else, our renderer tree may or may not contain the painting root, so we pass that root along
     // so it will be tested against as we descend through the renderers.
     RenderObject* paintingRootForRenderer = 0;
     if (localPaintingInfo.paintingRoot && !m_renderLayer.renderer()->isDescendantOf(localPaintingInfo.paintingRoot))
         paintingRootForRenderer = localPaintingInfo.paintingRoot;
@@ skipping 138 matching lines @@
             LayoutPoint delta;
             layer->convertToLayerCoords(localPaintingInfo.rootLayer, delta);
             clipRecorder.addRoundedRectClip(layer->renderer()->style()->getRoundedInnerBorderFor(LayoutRect(delta, layer->size())));
         }
 
         if (layer == localPaintingInfo.rootLayer)
             break;
     }
 }
 
-void LayerPainter::updatePaintingInfoForFragments(LayerFragments& fragments, const LayerPaintingInfo& localPaintingInfo, PaintLayerFlags localPaintFlags,
-    bool shouldPaintContent, const LayoutPoint* offsetFromRoot)
+bool LayerPainter::atLeastOneFragmentIntersectsDamageRect(LayerFragments& fragments, const LayerPaintingInfo& localPaintingInfo, PaintLayerFlags localPaintFlags, const LayoutPoint& offsetFromRoot)
 {
-    ASSERT(offsetFromRoot);
-    for (size_t i = 0; i < fragments.size(); ++i) {
-        LayerFragment& fragment = fragments.at(i);
-        fragment.shouldPaintContent = shouldPaintContent;
-        if (&m_renderLayer != localPaintingInfo.rootLayer || !(localPaintFlags & PaintLayerPaintingOverflowContents)) {
-            LayoutPoint newOffsetFromRoot = *offsetFromRoot + fragment.paginationOffset;
-            fragment.shouldPaintContent &= m_renderLayer.intersectsDamageRect(fragment.layerBounds, fragment.backgroundRect.rect(), localPaintingInfo.rootLayer, &newOffsetFromRoot);
-        }
+    if (m_renderLayer.enclosingPaginationLayer())
+        return true; // The fragments created have already been found to intersect with the damage rect.
+
+    if (&m_renderLayer == localPaintingInfo.rootLayer && (localPaintFlags & PaintLayerPaintingOverflowContents))
+        return true;
+
+    for (LayerFragment& fragment: fragments) {
+        LayoutPoint newOffsetFromRoot = offsetFromRoot + fragment.paginationOffset;
+        // Note that this really only works reliably on the first fragment. If the layer has visible
+        // overflow and a subsequent fragment doesn't intersect with the border box of the layer
+        // (i.e. only contains an overflow portion of the layer), intersection will fail. The reason
+        // for this is that fragment.layerBounds is set to the border box, not the bounding box, of
+        // the layer.
+        if (m_renderLayer.intersectsDamageRect(fragment.layerBounds, fragment.backgroundRect.rect(), localPaintingInfo.rootLayer, &newOffsetFromRoot))
+            return true;
     }
+    return false;
 }
 
 void LayerPainter::paintLayerByApplyingTransform(GraphicsContext* context, const LayerPaintingInfo& paintingInfo, PaintLayerFlags paintFlags, const LayoutPoint& translationOffset)
 {
     // This involves subtracting out the position of the layer in our current coordinate space, but preserving
     // the accumulated error for sub-pixel layout.
     LayoutPoint delta;
     m_renderLayer.convertToLayerCoords(paintingInfo.rootLayer, delta);
     delta.moveBy(translationOffset);
     TransformationMatrix transform(m_renderLayer.renderableTransform(paintingInfo.paintBehavior));
@@ skipping 219 matching lines @@
             currLogicalTopOffset -= blockDelta;
     }
 }
 
 void LayerPainter::paintBackgroundForFragments(const LayerFragments& layerFragments, GraphicsContext* context,
     const LayoutRect& transparencyPaintDirtyRect, bool haveTransparency, const LayerPaintingInfo& localPaintingInfo, PaintBehavior paintBehavior,
     RenderObject* paintingRootForRenderer, PaintLayerFlags paintFlags)
 {
     for (size_t i = 0; i < layerFragments.size(); ++i) {
         const LayerFragment& fragment = layerFragments.at(i);
-        if (!fragment.shouldPaintContent)
-            continue;
 
         // Begin transparency layers lazily now that we know we have to paint something.
         if (haveTransparency || m_renderLayer.paintsWithBlendMode())
             beginTransparencyLayers(context, localPaintingInfo.rootLayer, transparencyPaintDirtyRect, localPaintingInfo.subPixelAccumulation, localPaintingInfo.paintBehavior);
 
         OwnPtr<ClipRecorder> clipRecorder;
 
         if (localPaintingInfo.clipToDirtyRect && needsToClip(localPaintingInfo, fragment.backgroundRect)) {
             clipRecorder = adoptPtr(new ClipRecorder(&m_renderLayer, context, ClipDisplayItem::LayerBackground, fragment.backgroundRect));
             applyRoundedRectClips(localPaintingInfo, context, fragment.backgroundRect, paintFlags, *clipRecorder);
         }
 
         // Paint the background.
         // FIXME: Eventually we will collect the region from the fragment itself instead of just from the paint info.
         PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.backgroundRect.rect()), PaintPhaseBlockBackground, paintBehavior, paintingRootForRenderer, 0, localPaintingInfo.rootLayer->renderer());
         m_renderLayer.renderer()->paint(paintInfo, toPoint(fragment.layerBounds.location() - m_renderLayer.renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, m_renderLayer.compositingState())));
     }
 }
 
 void LayerPainter::paintForegroundForFragments(const LayerFragments& layerFragments, GraphicsContext* context,
     const LayoutRect& transparencyPaintDirtyRect, bool haveTransparency, const LayerPaintingInfo& localPaintingInfo, PaintBehavior paintBehavior,
     RenderObject* paintingRootForRenderer, bool selectionOnly, PaintLayerFlags paintFlags)
 {
     // Begin transparency if we have something to paint.
     if (haveTransparency || m_renderLayer.paintsWithBlendMode()) {
         for (size_t i = 0; i < layerFragments.size(); ++i) {
             const LayerFragment& fragment = layerFragments.at(i);
-            if (fragment.shouldPaintContent && !fragment.foregroundRect.isEmpty()) {
+            if (!fragment.foregroundRect.isEmpty()) {
                 beginTransparencyLayers(context, localPaintingInfo.rootLayer, transparencyPaintDirtyRect, localPaintingInfo.subPixelAccumulation, localPaintingInfo.paintBehavior);
                 break;
             }
         }
     }
 
     // Optimize clipping for the single fragment case.
-    bool shouldClip = localPaintingInfo.clipToDirtyRect && layerFragments.size() == 1 && layerFragments[0].shouldPaintContent && !layerFragments[0].foregroundRect.isEmpty();
+    bool shouldClip = localPaintingInfo.clipToDirtyRect && layerFragments.size() == 1 && !layerFragments[0].foregroundRect.isEmpty();
 
     OwnPtr<ClipRecorder> clipRecorder;
     if (shouldClip && needsToClip(localPaintingInfo, layerFragments[0].foregroundRect)) {
         clipRecorder = adoptPtr(new ClipRecorder(&m_renderLayer, context, ClipDisplayItem::LayerForeground, layerFragments[0].foregroundRect));
         applyRoundedRectClips(localPaintingInfo, context, layerFragments[0].foregroundRect, paintFlags, *clipRecorder);
     }
 
     // We have to loop through every fragment multiple times, since we have to issue paint invalidations in each specific phase in order for
     // interleaving of the fragments to work properly.
     paintForegroundForFragmentsWithPhase(selectionOnly ? PaintPhaseSelection : PaintPhaseChildBlockBackgrounds, layerFragments,
         context, localPaintingInfo, paintBehavior, paintingRootForRenderer, paintFlags);
 
     if (!selectionOnly) {
         paintForegroundForFragmentsWithPhase(PaintPhaseFloat, layerFragments, context, localPaintingInfo, paintBehavior, paintingRootForRenderer, paintFlags);
         paintForegroundForFragmentsWithPhase(PaintPhaseForeground, layerFragments, context, localPaintingInfo, paintBehavior, paintingRootForRenderer, paintFlags);
         paintForegroundForFragmentsWithPhase(PaintPhaseChildOutlines, layerFragments, context, localPaintingInfo, paintBehavior, paintingRootForRenderer, paintFlags);
     }
 }
 
 void LayerPainter::paintForegroundForFragmentsWithPhase(PaintPhase phase, const LayerFragments& layerFragments, GraphicsContext* context,
     const LayerPaintingInfo& localPaintingInfo, PaintBehavior paintBehavior, RenderObject* paintingRootForRenderer, PaintLayerFlags paintFlags)
 {
     bool shouldClip = localPaintingInfo.clipToDirtyRect && layerFragments.size() > 1;
 
     for (size_t i = 0; i < layerFragments.size(); ++i) {
         const LayerFragment& fragment = layerFragments.at(i);
-        if (!fragment.shouldPaintContent || fragment.foregroundRect.isEmpty())
+        if (fragment.foregroundRect.isEmpty())
             continue;
 
         OwnPtr<ClipRecorder> clipRecorder;
         if (shouldClip && needsToClip(localPaintingInfo, fragment.foregroundRect)) {
             // Note: this method only clips when there is more than one fragment.
             ClipDisplayItem::ClipType clipType = ClipDisplayItem::LayerFragmentFloat;
             switch (phase) {
             case PaintPhaseFloat:
                 break;
             case PaintPhaseForeground:
@@ skipping 39 matching lines @@
         PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.outlineRect.rect()), PaintPhaseSelfOutline, paintBehavior, paintingRootForRenderer, 0, localPaintingInfo.rootLayer->renderer());
         m_renderLayer.renderer()->paint(paintInfo, toPoint(fragment.layerBounds.location() - m_renderLayer.renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, m_renderLayer.compositingState())));
     }
 }
 
 void LayerPainter::paintMaskForFragments(const LayerFragments& layerFragments, GraphicsContext* context, const LayerPaintingInfo& localPaintingInfo,
     RenderObject* paintingRootForRenderer, PaintLayerFlags paintFlags)
 {
     for (size_t i = 0; i < layerFragments.size(); ++i) {
         const LayerFragment& fragment = layerFragments.at(i);
-        if (!fragment.shouldPaintContent)
-            continue;
-
         OwnPtr<ClipRecorder> clipRecorder;
         if (localPaintingInfo.clipToDirtyRect && needsToClip(localPaintingInfo, fragment.backgroundRect)) {
             clipRecorder = adoptPtr(new ClipRecorder(&m_renderLayer, context, ClipDisplayItem::LayerFragmentMask, fragment.backgroundRect));
             applyRoundedRectClips(localPaintingInfo, context, fragment.backgroundRect, paintFlags, *clipRecorder, DoNotIncludeSelfForBorderRadius); // Mask painting will handle clipping to self.
         }
 
         // Paint the mask.
         // FIXME: Eventually we will collect the region from the fragment itself instead of just from the paint info.
         PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.backgroundRect.rect()), PaintPhaseMask, PaintBehaviorNormal, paintingRootForRenderer, 0, localPaintingInfo.rootLayer->renderer());
         m_renderLayer.renderer()->paint(paintInfo, toPoint(fragment.layerBounds.location() - m_renderLayer.renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, m_renderLayer.compositingState())));
     }
 }
 
 void LayerPainter::paintChildClippingMaskForFragments(const LayerFragments& layerFragments, GraphicsContext* context, const LayerPaintingInfo& localPaintingInfo,
     RenderObject* paintingRootForRenderer, PaintLayerFlags paintFlags)
 {
     for (size_t i = 0; i < layerFragments.size(); ++i) {
         const LayerFragment& fragment = layerFragments.at(i);
-        if (!fragment.shouldPaintContent)
-            continue;
-
         OwnPtr<ClipRecorder> clipRecorder;
         if (localPaintingInfo.clipToDirtyRect && needsToClip(localPaintingInfo, fragment.foregroundRect)) {
             clipRecorder = adoptPtr(new ClipRecorder(&m_renderLayer, context, ClipDisplayItem::LayerFragmentClippingMask, fragment.foregroundRect));
             applyRoundedRectClips(localPaintingInfo, context, fragment.foregroundRect, paintFlags, *clipRecorder, IncludeSelfForBorderRadius); // Child clipping mask painting will handle clipping to self.
         }
 
         // Paint the the clipped mask.
         PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.backgroundRect.rect()), PaintPhaseClippingMask, PaintBehaviorNormal, paintingRootForRenderer, 0, localPaintingInfo.rootLayer->renderer());
         m_renderLayer.renderer()->paint(paintInfo, toPoint(fragment.layerBounds.location() - m_renderLayer.renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, m_renderLayer.compositingState())));
     }
@@ skipping 42 matching lines @@
         if (needsToClip(paintingInfo, clipRect)) {
             clipRecorder = adoptPtr(new ClipRecorder(m_renderLayer.parent(), context, ClipDisplayItem::LayerFragmentParent, clipRect));
             LayerPainter(*m_renderLayer.parent()).applyRoundedRectClips(paintingInfo, context, clipRect, paintFlags, *clipRecorder, DoNotIncludeSelfForBorderRadius); // Child clipping mask painting will handle clipping to self.
         }
 
         paintLayerByApplyingTransform(context, paintingInfo, paintFlags, fragment.paginationOffset);
     }
 }
 
 } // namespace blink