void PaintLayerClipper::calculateClipRects(const ClipRectsContext& context, ClipRects& clipRects) const
{
bool rootLayerScrolls = m_layoutObject.document().settings() && m_layoutObject.document().settings()->rootLayerScrolls();
if (!m_layoutObject.layer()->parent() && !rootLayerScrolls) {
// The root layer's clip rect is always infinite.
clipRects.reset(LayoutRect(LayoutRect::infiniteIntRect()));
return;
}
bool isClippingRoot = m_layoutObject.layer() == context.rootLayer;
// For transformed layers, the root layer was shifted to be us, so there is no need to
// examine the parent. We want to cache clip rects with us as the root.
PaintLayer* parentLayer = !isClippingRoot ? m_layoutObject.layer()->parent() : 0;
// Ensure that our parent's clip has been calculated so that we can examine the values.
if (parentLayer) {
// FIXME: Why don't we just call getClipRects here?
if (context.usesCache() && parentLayer->clipper().cachedClipRects(context)) {
clipRects = *parentLayer->clipper().cachedClipRects(context);
} else {
parentLayer->clipper().calculateClipRects(context, clipRects);
}
} else {
clipRects.reset(LayoutRect(LayoutRect::infiniteIntRect()));
}
adjustClipRectsForChildren(m_layoutObject, clipRects);
if ((m_layoutObject.hasOverflowClip() && shouldRespectOverflowClip(context)) || m_layoutObject.hasClip()) {
// This offset cannot use convertToLayerCoords, because sometimes our rootLayer may be across
// some transformed layer boundary, for example, in the PaintLayerCompositor overlapMap, where
// clipRects are needed in view space.
applyClipRects(context, m_layoutObject, roundedLayoutPoint(m_layoutObject.localToContainerPoint(FloatPoint(), context.rootLayer->layoutObject())), clipRects);
}
}
void PaintLayerClipper::calculateRects(const ClipRectsContext& context, const LayoutRect& paintDirtyRect, LayoutRect& layerBounds,
ClipRect& backgroundRect, ClipRect& foregroundRect, const LayoutPoint* offsetFromRoot) const
{
bool isClippingRoot = m_layoutObject.layer() == context.rootLayer;
if (!isClippingRoot && m_layoutObject.layer()->parent()) {
backgroundRect = backgroundClipRect(context);
backgroundRect.move(context.subPixelAccumulation);
backgroundRect.intersect(paintDirtyRect);
} else {
backgroundRect = paintDirtyRect;
}
foregroundRect = backgroundRect;
LayoutPoint offset;
if (offsetFromRoot)
offset = *offsetFromRoot;
else
m_layoutObject.layer()->convertToLayerCoords(context.rootLayer, offset);
layerBounds = LayoutRect(offset, LayoutSize(m_layoutObject.layer()->size()));
// Update the clip rects that will be passed to child layers.
if (m_layoutObject.hasOverflowClip() && shouldRespectOverflowClip(context)) {
foregroundRect.intersect(toLayoutBox(m_layoutObject).overflowClipRect(offset, context.scrollbarRelevancy));
if (m_layoutObject.style()->hasBorderRadius())
foregroundRect.setHasRadius(true);
// FIXME: Does not do the right thing with columns yet, since we don't yet factor in the
// individual column boxes as overflow.
// The LayoutView is special since its overflow clipping rect may be larger than its box rect (crbug.com/492871).
LayoutRect layerBoundsWithVisualOverflow = m_layoutObject.isLayoutView() ? toLayoutView(m_layoutObject).viewRect() : toLayoutBox(m_layoutObject).visualOverflowRect();
toLayoutBox(m_layoutObject).flipForWritingMode(layerBoundsWithVisualOverflow); // PaintLayer are in physical coordinates, so the overflow has to be flipped.
layerBoundsWithVisualOverflow.moveBy(offset);
backgroundRect.intersect(layerBoundsWithVisualOverflow);
}
// CSS clip (different than clipping due to overflow) can clip to any box, even if it falls outside of the border box.
if (m_layoutObject.hasClip()) {
// Clip applies to *us* as well, so go ahead and update the damageRect.
LayoutRect newPosClip = toLayoutBox(m_layoutObject).clipRect(offset);
backgroundRect.intersect(newPosClip);
backgroundRect.setIsClippedByClipCss();
foregroundRect.intersect(newPosClip);
foregroundRect.setIsClippedByClipCss();
}
}
PaintLayerPainter::PaintResult PaintLayerPainter::paintLayerWithTransform(GraphicsContext* context, const PaintLayerPaintingInfo& paintingInfo, PaintLayerFlags paintFlags)
{
TransformationMatrix layerTransform = m_paintLayer.renderableTransform(paintingInfo.globalPaintFlags());
// If the transform can't be inverted, then don't paint anything.
if (!layerTransform.isInvertible())
return FullyPainted;
// FIXME: We should make sure that we don't walk past paintingInfo.rootLayer here.
// m_paintLayer may be the "root", and then we should avoid looking at its parent.
PaintLayer* parentLayer = m_paintLayer.parent();
ClipRect ancestorBackgroundClipRect;
if (parentLayer) {
// Calculate the clip rectangle that the ancestors establish.
ClipRectsContext clipRectsContext(paintingInfo.rootLayer, (paintFlags & PaintLayerUncachedClipRects) ? UncachedClipRects : PaintingClipRects, IgnoreOverlayScrollbarSize);
if (shouldRespectOverflowClip(paintFlags, m_paintLayer.layoutObject()) == IgnoreOverflowClip)
clipRectsContext.setIgnoreOverflowClip();
ancestorBackgroundClipRect = m_paintLayer.clipper().backgroundClipRect(clipRectsContext);
}
PaintLayer* paginationLayer = m_paintLayer.enclosingPaginationLayer();
PaintLayerFragments fragments;
if (paginationLayer) {
// FIXME: This is a mess. Look closely at this code and the code in Layer and fix any
// issues in it & refactor to make it obvious from code structure what it does and that it's
// correct.
ClipRectsCacheSlot cacheSlot = (paintFlags & PaintLayerUncachedClipRects) ? UncachedClipRects : PaintingClipRects;
ShouldRespectOverflowClip respectOverflowClip = shouldRespectOverflowClip(paintFlags, m_paintLayer.layoutObject());
// Calculate the transformed bounding box in the current coordinate space, to figure out
// which fragmentainers (e.g. columns) we need to visit.
LayoutRect transformedExtent = PaintLayer::transparencyClipBox(&m_paintLayer, paginationLayer, PaintLayer::PaintingTransparencyClipBox, PaintLayer::RootOfTransparencyClipBox, paintingInfo.subPixelAccumulation, paintingInfo.globalPaintFlags());
// FIXME: we don't check if paginationLayer is within paintingInfo.rootLayer here.
paginationLayer->collectFragments(fragments, paintingInfo.rootLayer, paintingInfo.paintDirtyRect, cacheSlot, IgnoreOverlayScrollbarSize, respectOverflowClip, 0, paintingInfo.subPixelAccumulation, &transformedExtent);
} else {
// We don't need to collect any fragments in the regular way here. We have already
// calculated a clip rectangle for the ancestry if it was needed, and clipping this
// layer is something that can be done further down the path, when the transform has
// been applied.
PaintLayerFragment fragment;
fragment.backgroundRect = paintingInfo.paintDirtyRect;
fragments.append(fragment);
}
bool needsScope = fragments.size() > 1;
PaintResult result = FullyPainted;
for (const auto& fragment : fragments) {
Optional<ScopeRecorder> scopeRecorder;
if (needsScope)
scopeRecorder.emplace(*context);
Optional<LayerClipRecorder> clipRecorder;
if (parentLayer) {
ClipRect clipRectForFragment(ancestorBackgroundClipRect);
clipRectForFragment.moveBy(fragment.paginationOffset);
clipRectForFragment.intersect(fragment.backgroundRect);
if (clipRectForFragment.isEmpty())
continue;
if (needsToClip(paintingInfo, clipRectForFragment)) {
if (m_paintLayer.layoutObject()->style()->position() != StaticPosition && clipRectForFragment.isClippedByClipCss())
UseCounter::count(m_paintLayer.layoutObject()->document(), UseCounter::ClipCssOfPositionedElement);
clipRecorder.emplace(*context, *parentLayer->layoutObject(), DisplayItem::ClipLayerParent, clipRectForFragment, &paintingInfo, fragment.paginationOffset, paintFlags);
}
}
if (paintFragmentByApplyingTransform(context, paintingInfo, paintFlags, fragment.paginationOffset) == MaybeNotFullyPainted)
result = MaybeNotFullyPainted;
}
return result;
}
bool PaintLayerClipper::shouldClipOverflow(
const ClipRectsContext& context) const {
return (m_layer.layoutObject()->hasOverflowClip() ||
m_layer.layoutObject()->styleRef().containsPaint()) &&
shouldRespectOverflowClip(context);
}
PaintLayerPainter::PaintResult PaintLayerPainter::paintLayerContentsInternal(GraphicsContext* context, const PaintLayerPaintingInfo& paintingInfoArg, PaintLayerFlags paintFlags, FragmentPolicy fragmentPolicy)
{
ASSERT(m_paintLayer.isSelfPaintingLayer() || m_paintLayer.hasSelfPaintingLayerDescendant());
ASSERT(!(paintFlags & PaintLayerAppliedTransform));
bool isSelfPaintingLayer = m_paintLayer.isSelfPaintingLayer();
bool isPaintingOverlayScrollbars = paintFlags & PaintLayerPaintingOverlayScrollbars;
bool isPaintingScrollingContent = paintFlags & PaintLayerPaintingCompositingScrollingPhase;
bool isPaintingCompositedForeground = paintFlags & PaintLayerPaintingCompositingForegroundPhase;
bool isPaintingCompositedBackground = paintFlags & PaintLayerPaintingCompositingBackgroundPhase;
bool isPaintingOverflowContents = paintFlags & PaintLayerPaintingOverflowContents;
// Outline always needs to be painted even if we have no visible content. Also,
// the outline is painted in the background phase during composited scrolling.
// If it were painted in the foreground phase, it would move with the scrolled
// content. When not composited scrolling, the outline is painted in the
// foreground phase. Since scrolled contents are moved by paint invalidation in this
// case, the outline won't get 'dragged along'.
bool shouldPaintOutline = isSelfPaintingLayer && !isPaintingOverlayScrollbars
&& ((isPaintingScrollingContent && isPaintingCompositedBackground)
|| (!isPaintingScrollingContent && isPaintingCompositedForeground));
bool shouldPaintContent = m_paintLayer.hasVisibleContent() && isSelfPaintingLayer && !isPaintingOverlayScrollbars;
PaintResult result = FullyPainted;
if (paintFlags & PaintLayerPaintingRootBackgroundOnly && !m_paintLayer.layoutObject()->isLayoutView() && !m_paintLayer.layoutObject()->isDocumentElement())
return result;
PaintLayerPaintingInfo paintingInfo = paintingInfoArg;
// Ensure our lists are up-to-date.
m_paintLayer.stackingNode()->updateLayerListsIfNeeded();
LayoutPoint offsetFromRoot;
m_paintLayer.convertToLayerCoords(paintingInfo.rootLayer, offsetFromRoot);
if (m_paintLayer.compositingState() == PaintsIntoOwnBacking)
offsetFromRoot.move(m_paintLayer.subpixelAccumulation());
else
offsetFromRoot.move(paintingInfo.subPixelAccumulation);
LayoutRect bounds = m_paintLayer.physicalBoundingBox(offsetFromRoot);
if (!paintingInfo.paintDirtyRect.contains(bounds))
result = MaybeNotFullyPainted;
LayoutRect rootRelativeBounds;
bool rootRelativeBoundsComputed = false;
if (paintingInfo.ancestorHasClipPathClipping && m_paintLayer.layoutObject()->style()->position() != StaticPosition)
UseCounter::count(m_paintLayer.layoutObject()->document(), UseCounter::ClipPathOfPositionedElement);
// These helpers output clip and compositing operations using a RAII pattern. Stack-allocated-varibles are destructed in the reverse order of construction,
// so they are nested properly.
ClipPathHelper clipPathHelper(context, m_paintLayer, paintingInfo, rootRelativeBounds, rootRelativeBoundsComputed, offsetFromRoot, paintFlags);
Optional<CompositingRecorder> compositingRecorder;
// Blending operations must be performed only with the nearest ancestor stacking context.
// Note that there is no need to composite if we're painting the root.
// FIXME: this should be unified further into PaintLayer::paintsWithTransparency().
bool shouldCompositeForBlendMode = (!m_paintLayer.layoutObject()->isDocumentElement() || m_paintLayer.layoutObject()->isSVGRoot()) && m_paintLayer.stackingNode()->isStackingContext() && m_paintLayer.hasNonIsolatedDescendantWithBlendMode();
if (shouldCompositeForBlendMode || m_paintLayer.paintsWithTransparency(paintingInfo.globalPaintFlags())) {
FloatRect compositingBounds = FloatRect(m_paintLayer.paintingExtent(paintingInfo.rootLayer, paintingInfo.subPixelAccumulation, paintingInfo.globalPaintFlags()));
compositingRecorder.emplace(*context, *m_paintLayer.layoutObject(),
WebCoreCompositeToSkiaComposite(CompositeSourceOver, m_paintLayer.layoutObject()->style()->blendMode()),
m_paintLayer.layoutObject()->opacity(), &compositingBounds);
}
PaintLayerPaintingInfo localPaintingInfo(paintingInfo);
if (m_paintLayer.compositingState() == PaintsIntoOwnBacking)
localPaintingInfo.subPixelAccumulation = m_paintLayer.subpixelAccumulation();
PaintLayerFragments layerFragments;
if (shouldPaintContent || shouldPaintOutline || isPaintingOverlayScrollbars) {
// Collect the fragments. This will compute the clip rectangles and paint offsets for each layer fragment.
ClipRectsCacheSlot cacheSlot = (paintFlags & PaintLayerUncachedClipRects) ? UncachedClipRects : PaintingClipRects;
ShouldRespectOverflowClip respectOverflowClip = shouldRespectOverflowClip(paintFlags, m_paintLayer.layoutObject());
if (fragmentPolicy == ForceSingleFragment)
m_paintLayer.appendSingleFragmentIgnoringPagination(layerFragments, localPaintingInfo.rootLayer, localPaintingInfo.paintDirtyRect, cacheSlot, IgnoreOverlayScrollbarSize, respectOverflowClip, &offsetFromRoot, localPaintingInfo.subPixelAccumulation);
else
m_paintLayer.collectFragments(layerFragments, localPaintingInfo.rootLayer, localPaintingInfo.paintDirtyRect, cacheSlot, IgnoreOverlayScrollbarSize, respectOverflowClip, &offsetFromRoot, localPaintingInfo.subPixelAccumulation);
if (shouldPaintContent) {
// TODO(wangxianzhu): This is for old slow scrolling. Implement similar optimization for slimming paint v2.
shouldPaintContent = atLeastOneFragmentIntersectsDamageRect(layerFragments, localPaintingInfo, paintFlags, offsetFromRoot);
if (!shouldPaintContent)
result = MaybeNotFullyPainted;
}
}
bool selectionOnly = localPaintingInfo.globalPaintFlags() & GlobalPaintSelectionOnly;
// If this layer's layoutObject is a child of the paintingRoot, we paint unconditionally, which
// is done by passing a nil paintingRoot down to our layoutObject (as if no paintingRoot was ever set).
// Else, our layout 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 layoutObjects.
LayoutObject* paintingRootForLayoutObject = 0;
if (localPaintingInfo.paintingRoot && !m_paintLayer.layoutObject()->isDescendantOf(localPaintingInfo.paintingRoot))
paintingRootForLayoutObject = localPaintingInfo.paintingRoot;
{ // Begin block for the lifetime of any filter.
FilterPainter filterPainter(m_paintLayer, context, offsetFromRoot, layerFragments.isEmpty() ? ClipRect() : layerFragments[0].backgroundRect, localPaintingInfo, paintFlags,
rootRelativeBounds, rootRelativeBoundsComputed);
bool shouldPaintBackground = isPaintingCompositedBackground && shouldPaintContent && !selectionOnly;
bool shouldPaintNegZOrderList = (isPaintingScrollingContent && isPaintingOverflowContents) || (!isPaintingScrollingContent && isPaintingCompositedBackground);
bool shouldPaintOwnContents = isPaintingCompositedForeground && shouldPaintContent;
bool shouldPaintNormalFlowAndPosZOrderLists = isPaintingCompositedForeground;
bool shouldPaintOverlayScrollbars = isPaintingOverlayScrollbars;
if (shouldPaintBackground) {
paintBackgroundForFragments(layerFragments, context, paintingInfo.paintDirtyRect,
localPaintingInfo, paintingRootForLayoutObject, paintFlags);
}
if (shouldPaintNegZOrderList) {
if (paintChildren(NegativeZOrderChildren, context, paintingInfo, paintFlags) == MaybeNotFullyPainted)
result = MaybeNotFullyPainted;
}
if (shouldPaintOwnContents) {
paintForegroundForFragments(layerFragments, context, paintingInfo.paintDirtyRect,
localPaintingInfo, paintingRootForLayoutObject, selectionOnly, paintFlags);
}
if (shouldPaintOutline)
paintOutlineForFragments(layerFragments, context, localPaintingInfo, paintingRootForLayoutObject, paintFlags);
if (shouldPaintNormalFlowAndPosZOrderLists) {
if (paintChildren(NormalFlowChildren | PositiveZOrderChildren, context, paintingInfo, paintFlags) == MaybeNotFullyPainted)
result = MaybeNotFullyPainted;
}
if (shouldPaintOverlayScrollbars)
paintOverflowControlsForFragments(layerFragments, context, localPaintingInfo, paintFlags);
} // FilterPainter block
bool shouldPaintMask = (paintFlags & PaintLayerPaintingCompositingMaskPhase) && shouldPaintContent && m_paintLayer.layoutObject()->hasMask() && !selectionOnly;
bool shouldPaintClippingMask = (paintFlags & PaintLayerPaintingChildClippingMaskPhase) && shouldPaintContent && !selectionOnly;
if (shouldPaintMask)
paintMaskForFragments(layerFragments, context, localPaintingInfo, paintingRootForLayoutObject, paintFlags);
if (shouldPaintClippingMask) {
// Paint the border radius mask for the fragments.
paintChildClippingMaskForFragments(layerFragments, context, localPaintingInfo, paintingRootForLayoutObject, paintFlags);
}
m_paintLayer.setPreviousScrollOffsetAccumulationForPainting(paintingInfoArg.scrollOffsetAccumulation);
return result;
}
