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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.
*
* 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"
#if ENABLE(SVG)
#include "RenderSVGResourceClipper.h"
#include "AffineTransform.h"
#include "FloatRect.h"
#include "GraphicsContext.h"
#include "HitTestRequest.h"
#include "HitTestResult.h"
#include "ImageBuffer.h"
#include "IntRect.h"
#include "RenderObject.h"
#include "RenderSVGResource.h"
#include "RenderStyle.h"
#include "SVGClipPathElement.h"
#include "SVGElement.h"
#include "SVGImageBufferTools.h"
#include "SVGNames.h"
#include "SVGRenderSupport.h"
#include "SVGResources.h"
#include "SVGStyledElement.h"
#include "SVGStyledTransformableElement.h"
#include "SVGUnitTypes.h"
#include "SVGUseElement.h"
#include <wtf/UnusedParam.h>
namespace WebCore {
RenderSVGResourceType RenderSVGResourceClipper::s_resourceType = ClipperResourceType;
RenderSVGResourceClipper::RenderSVGResourceClipper(SVGClipPathElement* node)
: RenderSVGResourceContainer(node)
, m_invalidationBlocked(false)
{
}
RenderSVGResourceClipper::~RenderSVGResourceClipper()
{
if (m_clipper.isEmpty())
return;
deleteAllValues(m_clipper);
m_clipper.clear();
}
void RenderSVGResourceClipper::removeAllClientsFromCache(bool markForInvalidation)
{
if (m_invalidationBlocked)
return;
m_clipBoundaries = FloatRect();
if (!m_clipper.isEmpty()) {
deleteAllValues(m_clipper);
m_clipper.clear();
}
markAllClientsForInvalidation(markForInvalidation ? LayoutAndBoundariesInvalidation : ParentOnlyInvalidation);
}
void RenderSVGResourceClipper::removeClientFromCache(RenderObject* client, bool markForInvalidation)
{
ASSERT(client);
if (m_invalidationBlocked)
return;
if (m_clipper.contains(client))
delete m_clipper.take(client);
markClientForInvalidation(client, markForInvalidation ? BoundariesInvalidation : ParentOnlyInvalidation);
}
bool RenderSVGResourceClipper::applyResource(RenderObject* object, RenderStyle*, GraphicsContext*& context, unsigned short resourceMode)
{
ASSERT(object);
ASSERT(context);
#ifndef NDEBUG
ASSERT(resourceMode == ApplyToDefaultMode);
#else
UNUSED_PARAM(resourceMode);
#endif
return applyClippingToContext(object, object->objectBoundingBox(), object->repaintRectInLocalCoordinates(), context);
}
bool RenderSVGResourceClipper::pathOnlyClipping(GraphicsContext* context, 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 = node()->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() || !static_cast<SVGElement*>(childNode)->isStyledTransformable())
continue;
SVGStyledTransformableElement* styled = static_cast<SVGStyledTransformableElement*>(childNode);
RenderStyle* style = renderer->style();
if (!style || 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 (static_cast<SVGClipPathElement*>(node())->clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
AffineTransform transform;
transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
clipPath.transform(transform);
}
// 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(RenderObject* object, const FloatRect& objectBoundingBox,
const FloatRect& repaintRect, GraphicsContext* context)
{
if (!m_clipper.contains(object))
m_clipper.set(object, new ClipperData);
bool shouldCreateClipData = false;
ClipperData* clipperData = m_clipper.get(object);
if (!clipperData->clipMaskImage) {
if (pathOnlyClipping(context, objectBoundingBox))
return true;
shouldCreateClipData = true;
}
AffineTransform absoluteTransform;
SVGImageBufferTools::calculateTransformationToOutermostSVGCoordinateSystem(object, absoluteTransform);
FloatRect absoluteTargetRect = absoluteTransform.mapRect(repaintRect);
FloatRect clampedAbsoluteTargetRect = SVGImageBufferTools::clampedAbsoluteTargetRectForRenderer(object, absoluteTargetRect);
if (shouldCreateClipData && !clampedAbsoluteTargetRect.isEmpty()) {
if (!SVGImageBufferTools::createImageBuffer(absoluteTargetRect, clampedAbsoluteTargetRect, clipperData->clipMaskImage, ColorSpaceDeviceRGB))
return false;
GraphicsContext* maskContext = clipperData->clipMaskImage->context();
ASSERT(maskContext);
// The save/restore pair is needed for clipToImageBuffer - it doesn't work without it on non-Cg platforms.
maskContext->save();
maskContext->translate(-clampedAbsoluteTargetRect.x(), -clampedAbsoluteTargetRect.y());
maskContext->concatCTM(absoluteTransform);
// clipPath can also be clipped by another clipPath.
if (SVGResources* resources = SVGResourcesCache::cachedResourcesForRenderObject(this)) {
if (RenderSVGResourceClipper* clipper = resources->clipper()) {
if (!clipper->applyClippingToContext(this, objectBoundingBox, repaintRect, maskContext)) {
maskContext->restore();
return false;
}
}
}
drawContentIntoMaskImage(clipperData, objectBoundingBox);
maskContext->restore();
}
if (!clipperData->clipMaskImage)
return false;
SVGImageBufferTools::clipToImageBuffer(context, absoluteTransform, clampedAbsoluteTargetRect, clipperData->clipMaskImage);
return true;
}
bool RenderSVGResourceClipper::drawContentIntoMaskImage(ClipperData* clipperData, const FloatRect& objectBoundingBox)
{
ASSERT(clipperData);
ASSERT(clipperData->clipMaskImage);
GraphicsContext* maskContext = clipperData->clipMaskImage->context();
ASSERT(maskContext);
AffineTransform maskContentTransformation;
SVGClipPathElement* clipPath = static_cast<SVGClipPathElement*>(node());
if (clipPath->clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
maskContentTransformation.translate(objectBoundingBox.x(), objectBoundingBox.y());
maskContentTransformation.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
maskContext->concatCTM(maskContentTransformation);
}
// Draw all clipPath children into a global mask.
for (Node* childNode = node()->firstChild(); childNode; childNode = childNode->nextSibling()) {
RenderObject* renderer = childNode->renderer();
if (!childNode->isSVGElement() || !static_cast<SVGElement*>(childNode)->isStyled() || !renderer)
continue;
RenderStyle* style = renderer->style();
if (!style || style->display() == NONE || style->visibility() != VISIBLE)
continue;
WindRule newClipRule = style->svgStyle()->clipRule();
bool isUseElement = renderer->isSVGShadowTreeRootContainer();
if (isUseElement) {
SVGUseElement* useElement = static_cast<SVGUseElement*>(childNode);
renderer = useElement->rendererClipChild();
if (!renderer)
continue;
if (!useElement->hasAttribute(SVGNames::clip_ruleAttr))
newClipRule = renderer->style()->svgStyle()->clipRule();
}
// Only shapes, paths and texts are allowed for clipping.
if (!renderer->isSVGPath() && !renderer->isSVGText())
continue;
// Save the old RenderStyle of the current object for restoring after drawing
// it to the MaskImage. The new intermediate RenderStyle needs to inherit from
// the old one.
RefPtr<RenderStyle> oldRenderStyle = renderer->style();
RefPtr<RenderStyle> newRenderStyle = RenderStyle::clone(oldRenderStyle.get());
SVGRenderStyle* svgStyle = newRenderStyle.get()->accessSVGStyle();
svgStyle->setFillPaint(SVGPaint::defaultFill());
svgStyle->setStrokePaint(SVGPaint::defaultStroke());
svgStyle->setFillRule(newClipRule);
newRenderStyle.get()->setOpacity(1.0f);
svgStyle->setFillOpacity(1.0f);
svgStyle->setStrokeOpacity(1.0f);
svgStyle->setFilterResource(String());
svgStyle->setMaskerResource(String());
// The setStyle() call results in a styleDidChange() call, which in turn invalidations the resources.
// As we're mutating the resource on purpose, block updates until we've resetted the style again.
m_invalidationBlocked = true;
renderer->setStyle(newRenderStyle.release());
// 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.
SVGImageBufferTools::renderSubtreeToImageBuffer(clipperData->clipMaskImage.get(), isUseElement ? childNode->renderer() : renderer, maskContentTransformation);
renderer->setStyle(oldRenderStyle.release());
m_invalidationBlocked = false;
}
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 = node()->firstChild(); childNode; childNode = childNode->nextSibling()) {
RenderObject* renderer = childNode->renderer();
if (!childNode->isSVGElement() || !static_cast<SVGElement*>(childNode)->isStyled() || !renderer)
continue;
if (!renderer->isSVGPath() && !renderer->isSVGText() && !renderer->isSVGShadowTreeRootContainer())
continue;
RenderStyle* style = renderer->style();
if (!style || style->display() == NONE || style->visibility() != VISIBLE)
continue;
m_clipBoundaries.unite(renderer->localToParentTransform().mapRect(renderer->repaintRectInLocalCoordinates()));
}
}
bool RenderSVGResourceClipper::hitTestClipContent(const FloatRect& objectBoundingBox, const FloatPoint& nodeAtPoint)
{
FloatPoint point = nodeAtPoint;
if (!SVGRenderSupport::pointInClippingArea(this, point))
return false;
if (static_cast<SVGClipPathElement*>(node())->clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
AffineTransform transform;
transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
point = transform.inverse().mapPoint(point);
}
for (Node* childNode = node()->firstChild(); childNode; childNode = childNode->nextSibling()) {
RenderObject* renderer = childNode->renderer();
if (!childNode->isSVGElement() || !static_cast<SVGElement*>(childNode)->isStyled() || !renderer)
continue;
if (!renderer->isSVGPath() && !renderer->isSVGText() && !renderer->isSVGShadowTreeRootContainer())
continue;
IntPoint hitPoint;
HitTestResult result(hitPoint);
if (renderer->nodeAtFloatPoint(HitTestRequest(HitTestRequest::SVGClipContent), result, point, HitTestForeground))
return true;
}
return false;
}
FloatRect RenderSVGResourceClipper::resourceBoundingBox(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 (static_cast<SVGClipPathElement*>(node())->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;
}
}
#endif // ENABLE(SVG)