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/*
* Copyright (C) 2004, 2005, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
* Copyright (C) 2004, 2005, 2006, 2007, 2008 Rob Buis <buis@kde.org>
* Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
* Copyright (C) 2011 Dirk Schulze <krit@webkit.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "config.h"
#include "RenderSVGResourceClipper.h"
#include "ElementIterator.h"
#include "Frame.h"
#include "FrameView.h"
#include "HitTestRequest.h"
#include "HitTestResult.h"
#include "IntRect.h"
#include "Logging.h"
#include "RenderSVGText.h"
#include "RenderStyle.h"
#include "RenderView.h"
#include "SVGNames.h"
#include "SVGRenderingContext.h"
#include "SVGResources.h"
#include "SVGResourcesCache.h"
#include "SVGUseElement.h"
#include <wtf/IsoMallocInlines.h>
#include <wtf/text/TextStream.h>
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(RenderSVGResourceClipper);
RenderSVGResourceClipper::RenderSVGResourceClipper(SVGClipPathElement& element, RenderStyle&& style)
: RenderSVGResourceContainer(element, WTFMove(style))
{
}
RenderSVGResourceClipper::~RenderSVGResourceClipper() = default;
void RenderSVGResourceClipper::removeAllClientsFromCache(bool markForInvalidation)
{
m_clipBoundaries = { };
m_clipper.clear();
markAllClientsForInvalidation(markForInvalidation ? LayoutAndBoundariesInvalidation : ParentOnlyInvalidation);
}
void RenderSVGResourceClipper::removeClientFromCache(RenderElement& client, bool markForInvalidation)
{
m_clipper.remove(&client);
markClientForInvalidation(client, markForInvalidation ? BoundariesInvalidation : ParentOnlyInvalidation);
}
bool RenderSVGResourceClipper::applyResource(RenderElement& renderer, const RenderStyle&, GraphicsContext*& context, OptionSet<RenderSVGResourceMode> resourceMode)
{
ASSERT(context);
ASSERT_UNUSED(resourceMode, !resourceMode);
auto repaintRect = renderer.repaintRectInLocalCoordinates();
if (repaintRect.isEmpty())
return true;
return applyClippingToContext(renderer, renderer.objectBoundingBox(), *context);
}
bool RenderSVGResourceClipper::pathOnlyClipping(GraphicsContext& context, const AffineTransform& animatedLocalTransform, const FloatRect& objectBoundingBox)
{
// If the current clip-path gets clipped itself, we have to fall back to masking.
if (style().clipPath())
return false;
WindRule clipRule = WindRule::NonZero;
Path clipPath;
// 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()) {
auto* renderer = childNode->renderer();
if (!renderer)
continue;
// Only shapes or paths are supported for direct clipping. We need to fall back to masking for texts.
if (is<RenderSVGText>(renderer))
return false;
if (!is<SVGGraphicsElement>(*childNode))
continue;
auto& style = renderer->style();
if (style.display() == DisplayType::None || style.visibility() != Visibility::Visible)
continue;
// Current shape in clip-path gets clipped too. Fall back to masking.
if (style.clipPath())
return false;
// Fall back to masking if there is more than one clipping path.
if (!clipPath.isEmpty())
return false;
clipPath = downcast<SVGGraphicsElement>(*childNode).toClipPath();
clipRule = style.svgStyle().clipRule();
}
// 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.location());
transform.scale(objectBoundingBox.size());
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;
}
bool RenderSVGResourceClipper::applyClippingToContext(RenderElement& renderer, const FloatRect& objectBoundingBox, GraphicsContext& context)
{
ClipperData& clipperData = addRendererToClipper(renderer);
LOG_WITH_STREAM(SVG, stream << "RenderSVGResourceClipper " << this << " applyClippingToContext: renderer " << &renderer << " objectBoundingBox " << objectBoundingBox << " (existing image buffer " << clipperData.imageBuffer.get() << ")");
AffineTransform animatedLocalTransform = clipPathElement().animatedLocalTransform();
if (!clipperData.imageBuffer && pathOnlyClipping(context, animatedLocalTransform, objectBoundingBox))
return true;
AffineTransform absoluteTransform = SVGRenderingContext::calculateTransformationToOutermostCoordinateSystem(renderer);
if (!clipperData.isValidForGeometry(objectBoundingBox, absoluteTransform)) {
// FIXME (149469): This image buffer should not be unconditionally unaccelerated. Making it match the context breaks nested clipping, though.
auto maskImage = SVGRenderingContext::createImageBuffer(objectBoundingBox, absoluteTransform, ColorSpace::SRGB, RenderingMode::Unaccelerated, &context);
if (!maskImage)
return false;
clipperData = { WTFMove(maskImage), objectBoundingBox, absoluteTransform };
GraphicsContext& maskContext = clipperData.imageBuffer->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, maskContext))
return false;
succeeded = drawContentIntoMaskImage(*clipperData.imageBuffer, objectBoundingBox);
// The context restore applies the clipping on non-CG platforms.
} else
succeeded = drawContentIntoMaskImage(*clipperData.imageBuffer, objectBoundingBox);
if (!succeeded)
clipperData = { };
}
if (!clipperData.imageBuffer)
return false;
SVGRenderingContext::clipToImageBuffer(context, absoluteTransform, objectBoundingBox, clipperData.imageBuffer, true);
return true;
}
bool RenderSVGResourceClipper::drawContentIntoMaskImage(ImageBuffer& maskImageBuffer, const FloatRect& objectBoundingBox)
{
GraphicsContext& maskContext = maskImageBuffer.context();
AffineTransform maskContentTransformation;
if (clipPathElement().clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
maskContentTransformation.translate(objectBoundingBox.location());
maskContentTransformation.scale(objectBoundingBox.size());
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)
auto oldBehavior = view().frameView().paintBehavior();
view().frameView().setPaintBehavior(oldBehavior | PaintBehavior::RenderingSVGMask);
// 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() == DisplayType::None || style.visibility() != 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 renderSubtreeToContext() to apply it's x/y/transform/etc. values when rendering.
// So if isUseElement is true, refetch the childNode->renderer(), as renderer got overridden above.
SVGRenderingContext::renderSubtreeToContext(maskContext, isUseElement ? *child.renderer() : *renderer, maskContentTransformation);
}
view().frameView().setPaintBehavior(oldBehavior);
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() == DisplayType::None || style.visibility() != Visibility::Visible)
continue;
m_clipBoundaries.unite(renderer->localToParentTransform().mapRect(renderer->repaintRectInLocalCoordinates()));
}
m_clipBoundaries = clipPathElement().animatedLocalTransform().mapRect(m_clipBoundaries);
}
RenderSVGResourceClipper::ClipperData& RenderSVGResourceClipper::addRendererToClipper(const RenderObject& object)
{
return m_clipper.add(&object, ClipperData()).iterator->value;
}
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.location());
transform.scale(objectBoundingBox.size());
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;
const RenderStyle& style = renderer->style();
if (is<ReferenceClipPathOperation>(style.clipPath())) {
auto& clipPath = downcast<ReferenceClipPathOperation>(*style.clipPath());
AtomString id(clipPath.fragment());
RenderSVGResourceClipper* clipper = getRenderSVGResourceById<RenderSVGResourceClipper>(document(), id);
if (clipper == this)
continue;
}
IntPoint hitPoint;
HitTestResult result(hitPoint);
constexpr OptionSet<HitTestRequest::RequestType> hitType { HitTestRequest::SVGClipContent, HitTestRequest::DisallowUserAgentShadowContent };
if (renderer->nodeAtFloatPoint(hitType, result, point, HitTestForeground))
return true;
}
return false;
}
FloatRect RenderSVGResourceClipper::resourceBoundingBox(const RenderObject& object)
{
// Resource was not layouted yet. Give back the boundingBox of the object.
if (selfNeedsLayout()) {
addRendererToClipper(object); // For selfNeedsClientInvalidation().
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.location());
transform.scale(objectBoundingBox.size());
return transform.mapRect(m_clipBoundaries);
}
return m_clipBoundaries;
}
}