bool RenderSVGResourceClipper::drawContentIntoMaskImage(const ClipperMaskImage& clipperMaskImage, const FloatRect& objectBoundingBox)
{
ASSERT(clipperMaskImage);
GraphicsContext& maskContext = clipperMaskImage->context();
AffineTransform maskContentTransformation;
if (clipPathElement().clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
maskContentTransformation.translate(objectBoundingBox.x(), objectBoundingBox.y());
maskContentTransformation.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
maskContext.concatCTM(maskContentTransformation);
}
// Switch to a paint behavior where all children of this <clipPath> will be rendered using special constraints:
// - fill-opacity/stroke-opacity/opacity set to 1
// - masker/filter not applied when rendering the children
// - fill is set to the initial fill paint server (solid, black)
// - stroke is set to the initial stroke paint server (none)
PaintBehavior oldBehavior = view().frameView().paintBehavior();
view().frameView().setPaintBehavior(oldBehavior | PaintBehaviorRenderingSVGMask);
// Draw all clipPath children into a global mask.
for (auto& child : childrenOfType<SVGElement>(clipPathElement())) {
auto renderer = child.renderer();
if (!renderer)
continue;
if (renderer->needsLayout()) {
view().frameView().setPaintBehavior(oldBehavior);
return false;
}
const RenderStyle& style = renderer->style();
if (style.display() == NONE || style.visibility() != VISIBLE)
continue;
WindRule newClipRule = style.svgStyle().clipRule();
bool isUseElement = child.hasTagName(SVGNames::useTag);
if (isUseElement) {
SVGUseElement& useElement = downcast<SVGUseElement>(child);
renderer = useElement.rendererClipChild();
if (!renderer)
continue;
if (!useElement.hasAttributeWithoutSynchronization(SVGNames::clip_ruleAttr))
newClipRule = renderer->style().svgStyle().clipRule();
}
// Only shapes, paths and texts are allowed for clipping.
if (!renderer->isSVGShape() && !renderer->isSVGText())
continue;
maskContext.setFillRule(newClipRule);
// In the case of a <use> element, we obtained its renderere above, to retrieve its clipRule.
// We have to pass the <use> renderer itself to renderSubtreeToImageBuffer() to apply it's x/y/transform/etc. values when rendering.
// So if isUseElement is true, refetch the childNode->renderer(), as renderer got overriden above.
SVGRenderingContext::renderSubtreeToImageBuffer(clipperMaskImage.get(), isUseElement ? *child.renderer() : *renderer, maskContentTransformation);
}
view().frameView().setPaintBehavior(oldBehavior);
return true;
}
bool RenderSVGResourceClipper::hitTestClipContent(const FloatRect& objectBoundingBox, const FloatPoint& nodeAtPoint)
{
FloatPoint point = nodeAtPoint;
if (!SVGRenderSupport::pointInClippingArea(*this, point))
return false;
if (clipPathElement().clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
AffineTransform transform;
transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
point = transform.inverse().valueOr(AffineTransform()).mapPoint(point);
}
point = clipPathElement().animatedLocalTransform().inverse().valueOr(AffineTransform()).mapPoint(point);
for (Node* childNode = clipPathElement().firstChild(); childNode; childNode = childNode->nextSibling()) {
RenderObject* renderer = childNode->renderer();
if (!childNode->isSVGElement() || !renderer)
continue;
if (!renderer->isSVGShape() && !renderer->isSVGText() && !childNode->hasTagName(SVGNames::useTag))
continue;
IntPoint hitPoint;
HitTestResult result(hitPoint);
if (renderer->nodeAtFloatPoint(HitTestRequest(HitTestRequest::SVGClipContent | HitTestRequest::DisallowUserAgentShadowContent), result, point, HitTestForeground))
return true;
}
return false;
}
bool RenderSVGResourceClipper::pathOnlyClipping(GraphicsContext& context, const AffineTransform& animatedLocalTransform, const FloatRect& objectBoundingBox)
{
// If the current clip-path gets clipped itself, we have to fallback to masking.
if (!style().svgStyle().clipperResource().isEmpty())
return false;
WindRule clipRule = RULE_NONZERO;
Path clipPath = Path();
// If clip-path only contains one visible shape or path, we can use path-based clipping. Invisible
// shapes don't affect the clipping and can be ignored. If clip-path contains more than one
// visible shape, the additive clipping may not work, caused by the clipRule. EvenOdd
// as well as NonZero can cause self-clipping of the elements.
// See also http://www.w3.org/TR/SVG/painting.html#FillRuleProperty
for (Node* childNode = clipPathElement().firstChild(); childNode; childNode = childNode->nextSibling()) {
RenderObject* renderer = childNode->renderer();
if (!renderer)
continue;
// Only shapes or paths are supported for direct clipping. We need to fallback to masking for texts.
if (renderer->isSVGText())
return false;
if (!childNode->isSVGElement() || !downcast<SVGElement>(*childNode).isSVGGraphicsElement())
continue;
SVGGraphicsElement& styled = downcast<SVGGraphicsElement>(*childNode);
const RenderStyle& style = renderer->style();
if (style.display() == NONE || style.visibility() != VISIBLE)
continue;
const SVGRenderStyle& svgStyle = style.svgStyle();
// Current shape in clip-path gets clipped too. Fallback to masking.
if (!svgStyle.clipperResource().isEmpty())
return false;
// Fallback to masking, if there is more than one clipping path.
if (clipPath.isEmpty()) {
styled.toClipPath(clipPath);
clipRule = svgStyle.clipRule();
} else
return false;
}
// Only one visible shape/path was found. Directly continue clipping and transform the content to userspace if necessary.
if (clipPathElement().clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
AffineTransform transform;
transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
clipPath.transform(transform);
}
// Transform path by animatedLocalTransform.
clipPath.transform(animatedLocalTransform);
// The SVG specification wants us to clip everything, if clip-path doesn't have a child.
if (clipPath.isEmpty())
clipPath.addRect(FloatRect());
context.clipPath(clipPath, clipRule);
return true;
}
void RenderSVGResourceClipper::calculateClipContentRepaintRect()
{
// This is a rough heuristic to appraise the clip size and doesn't consider clip on clip.
for (Node* childNode = clipPathElement().firstChild(); childNode; childNode = childNode->nextSibling()) {
RenderObject* renderer = childNode->renderer();
if (!childNode->isSVGElement() || !renderer)
continue;
if (!renderer->isSVGShape() && !renderer->isSVGText() && !childNode->hasTagName(SVGNames::useTag))
continue;
const RenderStyle& style = renderer->style();
if (style.display() == NONE || style.visibility() != VISIBLE)
continue;
m_clipBoundaries.unite(renderer->localToParentTransform().mapRect(renderer->repaintRectInLocalCoordinates()));
}
m_clipBoundaries = clipPathElement().animatedLocalTransform().mapRect(m_clipBoundaries);
}
void SkSVGDevice::AutoElement::addClipResources(const SkDraw& draw, Resources* resources) {
SkASSERT(!draw.fClipStack->isWideOpen());
SkPath clipPath;
(void) draw.fClipStack->asPath(&clipPath);
SkString clipID = fResourceBucket->addClip();
const char* clipRule = clipPath.getFillType() == SkPath::kEvenOdd_FillType ?
"evenodd" : "nonzero";
{
// clipPath is in device space, but since we're only pushing transform attributes
// to the leaf nodes, so are all our elements => SVG userSpaceOnUse == device space.
AutoElement clipPathElement("clipPath", fWriter);
clipPathElement.addAttribute("id", clipID);
SkRect clipRect = SkRect::MakeEmpty();
if (clipPath.isEmpty() || clipPath.isRect(&clipRect)) {
AutoElement rectElement("rect", fWriter);
rectElement.addRectAttributes(clipRect);
rectElement.addAttribute("clip-rule", clipRule);
} else {
AutoElement pathElement("path", fWriter);
pathElement.addPathAttributes(clipPath);
pathElement.addAttribute("clip-rule", clipRule);
}
}
resources->fClip.printf("url(#%s)", clipID.c_str());
}
bool RenderSVGResourceClipper::applyClippingToContext(RenderElement& renderer, const FloatRect& objectBoundingBox,
const FloatRect& repaintRect, GraphicsContext* context)
{
bool missingClipperData = !m_clipper.contains(&renderer);
if (missingClipperData)
m_clipper.set(&renderer, std::make_unique<ClipperData>());
bool shouldCreateClipData = false;
AffineTransform animatedLocalTransform = clipPathElement().animatedLocalTransform();
ClipperData* clipperData = m_clipper.get(&renderer);
if (!clipperData->clipMaskImage) {
if (pathOnlyClipping(context, animatedLocalTransform, objectBoundingBox))
return true;
shouldCreateClipData = true;
}
AffineTransform absoluteTransform;
SVGRenderingContext::calculateTransformationToOutermostCoordinateSystem(&renderer, absoluteTransform);
if (shouldCreateClipData && !repaintRect.isEmpty()) {
if (!SVGRenderingContext::createImageBuffer(repaintRect, absoluteTransform, clipperData->clipMaskImage, ColorSpaceDeviceRGB, Unaccelerated))
return false;
GraphicsContext* maskContext = clipperData->clipMaskImage->context();
ASSERT(maskContext);
maskContext->concatCTM(animatedLocalTransform);
// clipPath can also be clipped by another clipPath.
SVGResources* resources = SVGResourcesCache::cachedResourcesForRenderObject(this);
RenderSVGResourceClipper* clipper;
bool succeeded;
if (resources && (clipper = resources->clipper())) {
GraphicsContextStateSaver stateSaver(*maskContext);
if (!clipper->applyClippingToContext(*this, objectBoundingBox, repaintRect, maskContext))
return false;
succeeded = drawContentIntoMaskImage(clipperData, objectBoundingBox);
// The context restore applies the clipping on non-CG platforms.
} else
succeeded = drawContentIntoMaskImage(clipperData, objectBoundingBox);
if (!succeeded)
clipperData->clipMaskImage.clear();
}
if (!clipperData->clipMaskImage)
return false;
SVGRenderingContext::clipToImageBuffer(context, absoluteTransform, repaintRect, clipperData->clipMaskImage, missingClipperData);
return true;
}
bool RenderSVGResourceClipper::applyClippingToContext(RenderElement& renderer, const FloatRect& objectBoundingBox, const FloatRect& repaintRect, GraphicsContext& context)
{
ClipperMaskImage& clipperMaskImage = addRendererToClipper(renderer);
bool shouldCreateClipperMaskImage = !clipperMaskImage;
AffineTransform animatedLocalTransform = clipPathElement().animatedLocalTransform();
if (shouldCreateClipperMaskImage && pathOnlyClipping(context, animatedLocalTransform, objectBoundingBox))
return true;
AffineTransform absoluteTransform = SVGRenderingContext::calculateTransformationToOutermostCoordinateSystem(renderer);
if (shouldCreateClipperMaskImage && !repaintRect.isEmpty()) {
// FIXME (149469): This image buffer should not be unconditionally unaccelerated. Making it match the context breaks nested clipping, though.
clipperMaskImage = SVGRenderingContext::createImageBuffer(repaintRect, absoluteTransform, ColorSpaceSRGB, Unaccelerated);
if (!clipperMaskImage)
return false;
GraphicsContext& maskContext = clipperMaskImage->context();
maskContext.concatCTM(animatedLocalTransform);
// clipPath can also be clipped by another clipPath.
auto* resources = SVGResourcesCache::cachedResourcesForRenderer(*this);
RenderSVGResourceClipper* clipper;
bool succeeded;
if (resources && (clipper = resources->clipper())) {
GraphicsContextStateSaver stateSaver(maskContext);
if (!clipper->applyClippingToContext(*this, objectBoundingBox, repaintRect, maskContext))
return false;
succeeded = drawContentIntoMaskImage(clipperMaskImage, objectBoundingBox);
// The context restore applies the clipping on non-CG platforms.
} else
succeeded = drawContentIntoMaskImage(clipperMaskImage, objectBoundingBox);
if (!succeeded)
clipperMaskImage.reset();
}
if (!clipperMaskImage)
return false;
SVGRenderingContext::clipToImageBuffer(context, absoluteTransform, repaintRect, clipperMaskImage, shouldCreateClipperMaskImage);
return true;
}
FloatRect RenderSVGResourceClipper::resourceBoundingBox(const RenderObject& object)
{
// Resource was not layouted yet. Give back the boundingBox of the object.
if (selfNeedsLayout())
return object.objectBoundingBox();
if (m_clipBoundaries.isEmpty())
calculateClipContentRepaintRect();
if (clipPathElement().clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
FloatRect objectBoundingBox = object.objectBoundingBox();
AffineTransform transform;
transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
return transform.mapRect(m_clipBoundaries);
}
return m_clipBoundaries;
}
