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; }