Walk render tree instead of render layers for paint.

sky/engine/core/rendering/RenderLayer.cpp

Index: sky/engine/core/rendering/RenderLayer.cpp
diff --git a/sky/engine/core/rendering/RenderLayer.cpp b/sky/engine/core/rendering/RenderLayer.cpp
index 2d8f89dd7b1f115563b6afd961843534682b7414..7ff87f2d4095716142753a5a4a348f8db3108143 100644
--- a/sky/engine/core/rendering/RenderLayer.cpp
+++ b/sky/engine/core/rendering/RenderLayer.cpp
@@ -741,13 +741,6 @@ void RenderLayer::updateStackingNode()
         m_stackingNode = nullptr;
 }
 
-void RenderLayer::paint(GraphicsContext* context, const LayoutRect& damageRect)
-{
-    TRACE_EVENT0("blink", "RenderLayer::paint");
-    LayerPaintingInfo paintingInfo(this, enclosingIntRect(damageRect), LayoutSize());
-    paintLayer(context, paintingInfo, PaintContent);
-}
-
 static bool inContainingBlockChain(RenderLayer* startLayer, RenderLayer* endLayer)
 {
     if (startLayer == endLayer)
@@ -795,231 +788,6 @@ void RenderLayer::restoreClip(GraphicsContext* context, const LayoutRect& paintD
     context->restore();
 }
 
-void RenderLayer::paintLayer(GraphicsContext* context, const LayerPaintingInfo& paintingInfo, PaintLayerFlags paintFlags)
-{
-    // Non self-painting leaf layers don't need to be painted as their renderer() should properly paint itself.
-    if (!isSelfPaintingLayer() && !hasSelfPaintingLayerDescendant())
-        return;
-
-    // If this layer is totally invisible then there is nothing to paint.
-    if (!renderer()->opacity())
-        return;
-
-    if (paintsWithTransform()) {
-        TransformationMatrix layerTransform = renderableTransform();
-        // If the transform can't be inverted, then don't paint anything.
-        if (!layerTransform.isInvertible())
-            return;
-
-        // If we have a transparency layer enclosing us and we are the root of a transform, then we need to establish the transparency
-        // layer from the parent now, assuming there is a parent
-        if (isTransparent()) {
-            if (parent())
-                parent()->beginTransparencyLayers(context, paintingInfo.rootLayer, paintingInfo.paintDirtyRect, paintingInfo.subPixelAccumulation);
-            else
-                beginTransparencyLayers(context, paintingInfo.rootLayer, paintingInfo.paintDirtyRect, paintingInfo.subPixelAccumulation);
-        }
-
-        // Make sure the parent's clip rects have been calculated.
-        ClipRect clipRect = paintingInfo.paintDirtyRect;
-        if (parent()) {
-            ClipRectsContext clipRectsContext(paintingInfo.rootLayer, PaintingClipRects);
-            clipRect = clipper().backgroundClipRect(clipRectsContext);
-            clipRect.intersect(paintingInfo.paintDirtyRect);
-
-            // Push the parent coordinate space's clip.
-            parent()->clipToRect(paintingInfo, context, clipRect);
-        }
-
-        paintLayerByApplyingTransform(context, paintingInfo, paintFlags);
-
-        // Restore the clip.
-        if (parent())
-            parent()->restoreClip(context, paintingInfo.paintDirtyRect, clipRect);
-
-        return;
-    }
-
-    paintLayerContents(context, paintingInfo, paintFlags);
-}
-
-void RenderLayer::paintLayerContents(GraphicsContext* context, const LayerPaintingInfo& paintingInfo, PaintLayerFlags paintFlags)
-{
-    ASSERT(isSelfPaintingLayer() || hasSelfPaintingLayerDescendant());
-
-    float deviceScaleFactor = blink::deviceScaleFactor(renderer()->frame());
-    context->setDeviceScaleFactor(deviceScaleFactor);
-
-    GraphicsContext* transparencyLayerContext = context;
-
-    m_stackingNode->updateLayerListsIfNeeded();
-
-    LayoutPoint offsetFromRoot;
-    convertToLayerCoords(paintingInfo.rootLayer, offsetFromRoot);
-
-    LayoutRect rootRelativeBounds;
-    bool rootRelativeBoundsComputed = false;
-
-    // Apply clip-path to context.
-    GraphicsContextStateSaver clipStateSaver(*context, false);
-    RenderStyle* style = renderer()->style();
-
-    // Clip-path, like border radius, must not be applied to the contents of a composited-scrolling container.
-    // It must, however, still be applied to the mask layer, so that the compositor can properly mask the
-    // scrolling contents and scrollbars.
-    if (renderer()->hasClipPath() && style) {
-        ASSERT(style->clipPath());
-        if (style->clipPath()->type() == ClipPathOperation::SHAPE) {
-            ShapeClipPathOperation* clipPath = toShapeClipPathOperation(style->clipPath());
-            if (clipPath->isValid()) {
-                clipStateSaver.save();
-
-                if (!rootRelativeBoundsComputed) {
-                    rootRelativeBounds = physicalBoundingBoxIncludingReflectionAndStackingChildren(paintingInfo.rootLayer, offsetFromRoot);
-                    rootRelativeBoundsComputed = true;
-                }
-
-                context->clipPath(clipPath->path(rootRelativeBounds), clipPath->windRule());
-            }
-        }
-    }
-
-    LayerPaintingInfo localPaintingInfo(paintingInfo);
-    FilterEffectRendererHelper filterPainter(filterRenderer() && paintsWithFilters());
-
-    LayoutRect layerBounds;
-    // FIXME(sky): Remove foregroundRect. It's unused.
-    ClipRect backgroundRect, foregroundRect;
-    ClipRectsContext clipRectsContext(localPaintingInfo.rootLayer, PaintingClipRects, localPaintingInfo.subPixelAccumulation);
-    clipper().calculateRects(clipRectsContext, localPaintingInfo.paintDirtyRect,
-        layerBounds, backgroundRect, foregroundRect,
-        &offsetFromRoot);
-
-    bool shouldPaintContent = isSelfPaintingLayer() && intersectsDamageRect(layerBounds, backgroundRect.rect(), localPaintingInfo.rootLayer, &offsetFromRoot);
-
-    bool haveTransparency = isTransparent();
-
-    if (filterPainter.haveFilterEffect()) {
-        ASSERT(this->filterInfo());
-
-        if (!rootRelativeBoundsComputed)
-            rootRelativeBounds = physicalBoundingBoxIncludingReflectionAndStackingChildren(paintingInfo.rootLayer, offsetFromRoot);
-
-        if (filterPainter.prepareFilterEffect(this, rootRelativeBounds, paintingInfo.paintDirtyRect)) {
-            // Rewire the old context to a memory buffer, so that we can capture the contents of the layer.
-            // NOTE: We saved the old context in the "transparencyLayerContext" local variable, to be able to start a transparency layer
-            // on the original context and avoid duplicating "beginFilterEffect" after each transparency layer call. Also, note that
-            // beginTransparencyLayers will only create a single lazy transparency layer, even though it is called twice in this method.
-            // With deferred filters, we don't need a separate context, but we do need to do transparency and clipping before starting
-            // filter processing.
-            // FIXME: when the legacy path is removed, remove the transparencyLayerContext as well.
-            if (haveTransparency) {
-                // If we have a filter and transparency, we have to eagerly start a transparency layer here, rather than risk a child layer lazily starts one after filter processing.
-                beginTransparencyLayers(context, localPaintingInfo.rootLayer, paintingInfo.paintDirtyRect, paintingInfo.subPixelAccumulation);
-            }
-            // We'll handle clipping to the dirty rect before filter rasterization.
-            // Filter processing will automatically expand the clip rect and the offscreen to accommodate any filter outsets.
-            // FIXME: It is incorrect to just clip to the damageRect here once multiple fragments are involved.
-            clipToRect(localPaintingInfo, context, backgroundRect);
-            // Subsequent code should not clip to the dirty rect, since we've already
-            // done it above, and doing it later will defeat the outsets.
-            localPaintingInfo.clipToDirtyRect = false;
-
-            context = filterPainter.beginFilterEffect(context);
-        }
-    }
-
-    LayoutPoint layerLocation = toPoint(layerBounds.location() - renderBoxLocation() + localPaintingInfo.subPixelAccumulation);
-
-    if (shouldPaintContent) {
-        paintForeground(context, transparencyLayerContext, paintingInfo.paintDirtyRect, haveTransparency,
-            localPaintingInfo, layerLocation, backgroundRect);
-    }
-
-    paintChildren(NormalFlowChildren | PositiveZOrderChildren, context, paintingInfo, paintFlags);
-
-    if (filterPainter.hasStartedFilterEffect()) {
-        context = filterPainter.applyFilterEffect();
-        restoreClip(transparencyLayerContext, localPaintingInfo.paintDirtyRect, backgroundRect);
-    }
-
-    // Make sure that we now use the original transparency context.
-    ASSERT(transparencyLayerContext == context);
-
-    // End our transparency layer
-    if (haveTransparency && m_usedTransparency) {
-        context->endLayer();
-        context->restore();
-        m_usedTransparency = false;
-    }
-}
-
-void RenderLayer::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;
-    convertToLayerCoords(paintingInfo.rootLayer, delta);
-    delta.moveBy(translationOffset);
-    TransformationMatrix transform(renderableTransform());
-    IntPoint roundedDelta = roundedIntPoint(delta);
-    transform.translateRight(roundedDelta.x(), roundedDelta.y());
-    LayoutSize adjustedSubPixelAccumulation = paintingInfo.subPixelAccumulation + (delta - roundedDelta);
-
-    // Apply the transform.
-    GraphicsContextStateSaver stateSaver(*context, false);
-    if (!transform.isIdentity()) {
-        stateSaver.save();
-        context->concatCTM(transform.toAffineTransform());
-    }
-
-    // Now do a paint with the root layer shifted to be us.
-    LayerPaintingInfo transformedPaintingInfo(this, enclosingIntRect(transform.inverse().mapRect(paintingInfo.paintDirtyRect)),
-        adjustedSubPixelAccumulation);
-    paintLayerContents(context, transformedPaintingInfo, paintFlags);
-}
-
-void RenderLayer::paintChildren(unsigned childrenToVisit, GraphicsContext* context, const LayerPaintingInfo& paintingInfo, PaintLayerFlags paintFlags)
-{
-    if (!hasSelfPaintingLayerDescendant())
-        return;
-
-#if ENABLE(ASSERT)
-    LayerListMutationDetector mutationChecker(m_stackingNode.get());
-#endif
-
-    RenderLayerStackingNodeIterator iterator(*m_stackingNode, childrenToVisit);
-    while (RenderLayerStackingNode* child = iterator.next()) {
-        child->layer()->paintLayer(context, paintingInfo, paintFlags);
-    }
-}
-
-void RenderLayer::paintForeground(GraphicsContext* context, GraphicsContext* transparencyLayerContext,
-    const LayoutRect& transparencyPaintDirtyRect, bool haveTransparency, const LayerPaintingInfo& localPaintingInfo,
-    LayoutPoint& layerLocation, ClipRect& layerForegroundRect)
-{
-    bool foregroundRectIsEmpty = layerForegroundRect.isEmpty();
-
-    // Begin transparency if we have something to paint.
-    if (haveTransparency && !foregroundRectIsEmpty)
-        beginTransparencyLayers(transparencyLayerContext, localPaintingInfo.rootLayer, transparencyPaintDirtyRect, localPaintingInfo.subPixelAccumulation);
-
-    // Optimize clipping for the single fragment case.
-    bool shouldClip = localPaintingInfo.clipToDirtyRect && !foregroundRectIsEmpty;
-    if (shouldClip)
-        clipToRect(localPaintingInfo, context, layerForegroundRect);
-
-    // TODO(ojan): We probably should early return at the beginning of this function
-    // if the rect is empty.
-    if (!foregroundRectIsEmpty) {
-        PaintInfo paintInfo(context, pixelSnappedIntRect(layerForegroundRect.rect()), localPaintingInfo.rootLayer->renderer());
-        renderer()->paint(paintInfo, layerLocation);
-    }
-
-    if (shouldClip)
-        restoreClip(context, localPaintingInfo.paintDirtyRect, layerForegroundRect);
-}
-
 static inline LayoutRect frameVisibleRect(RenderObject* renderer)
 {
     FrameView* frameView = renderer->document().view();