diff -r 000000000000 -r 4f2f89ce4247 WebCore/rendering/RenderSVGResourceClipper.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/WebCore/rendering/RenderSVGResourceClipper.cpp Fri Sep 17 09:02:29 2010 +0300 @@ -0,0 +1,345 @@ +/* + * Copyright (C) 2004, 2005, 2007, 2008 Nikolas Zimmermann + * 2004, 2005, 2006, 2007, 2008 Rob Buis + * 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 "RenderStyle.h" +#include "RenderSVGResource.h" +#include "SVGClipPathElement.h" +#include "SVGElement.h" +#include "SVGRenderSupport.h" +#include "SVGStyledElement.h" +#include "SVGStyledTransformableElement.h" +#include "SVGUnitTypes.h" +#include "SVGUseElement.h" +#include + +namespace WebCore { + +RenderSVGResourceType RenderSVGResourceClipper::s_resourceType = ClipperResourceType; + +RenderSVGResourceClipper::RenderSVGResourceClipper(SVGClipPathElement* node) + : RenderSVGResourceContainer(node) + , m_invalidationBlocked(false) +{ +} + +RenderSVGResourceClipper::~RenderSVGResourceClipper() +{ + deleteAllValues(m_clipper); + m_clipper.clear(); +} + +void RenderSVGResourceClipper::invalidateClients() +{ + if (m_invalidationBlocked) + return; + + HashMap::const_iterator end = m_clipper.end(); + for (HashMap::const_iterator it = m_clipper.begin(); it != end; ++it) + markForLayoutAndResourceInvalidation(it->first); + + deleteAllValues(m_clipper); + m_clipper.clear(); + m_clipBoundaries = FloatRect(); +} + +void RenderSVGResourceClipper::invalidateClient(RenderObject* object) +{ + if (m_invalidationBlocked) + return; + + ASSERT(object); + if (!m_clipper.contains(object)) + return; + + delete m_clipper.take(object); + markForLayoutAndResourceInvalidation(object); +} + +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 + + // Early exit, if this resource contains a child which references ourselves. + if (containsCyclicReference(node())) + return false; + + applyClippingToContext(object, object->objectBoundingBox(), object->repaintRectInLocalCoordinates(), context); + return true; +} + +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(childNode)->isStyledTransformable()) + continue; + SVGStyledTransformableElement* styled = static_cast(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()) { + clipPath = styled->toClipPath(); + 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(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->beginPath(); + context->addPath(clipPath); + context->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); + + ClipperData* clipperData = m_clipper.get(object); + if (!clipperData->clipMaskImage) { + if (pathOnlyClipping(context, objectBoundingBox)) + return true; + createClipData(clipperData, objectBoundingBox, repaintRect); + } + + if (!clipperData->clipMaskImage) + return false; + + context->clipToImageBuffer(repaintRect, clipperData->clipMaskImage.get()); + return true; +} + +bool RenderSVGResourceClipper::createClipData(ClipperData* clipperData, const FloatRect& objectBoundingBox, const FloatRect& repaintRect) +{ + IntRect clipMaskRect = enclosingIntRect(repaintRect); + clipperData->clipMaskImage = ImageBuffer::create(clipMaskRect.size()); + if (!clipperData->clipMaskImage) + return false; + + GraphicsContext* maskContext = clipperData->clipMaskImage->context(); + ASSERT(maskContext); + + maskContext->save(); + maskContext->translate(-repaintRect.x(), -repaintRect.y()); + + // clipPath can also be clipped by another clipPath. + if (RenderSVGResourceClipper* clipper = getRenderSVGResourceById(this->document(), style()->svgStyle()->clipperResource())) { + if (!clipper->applyClippingToContext(this, objectBoundingBox, repaintRect, maskContext)) { + maskContext->restore(); + return false; + } + } + + SVGClipPathElement* clipPath = static_cast(node()); + if (clipPath->clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) { + maskContext->translate(objectBoundingBox.x(), objectBoundingBox.y()); + maskContext->scale(objectBoundingBox.size()); + } + + // 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(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(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->isRenderPath() && !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 oldRenderStyle = renderer->style(); + RefPtr 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 element, we obtained its renderere above, to retrieve its clipRule. + // We hsve to pass the renderer itself to renderSubtreeToImage() 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. + SVGRenderSupport::renderSubtreeToImage(clipperData->clipMaskImage.get(), isUseElement ? childNode->renderer() : renderer); + + renderer->setStyle(oldRenderStyle.release()); + m_invalidationBlocked = false; + } + + maskContext->restore(); + + 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(childNode)->isStyled() || !renderer) + continue; + if (!renderer->isRenderPath() && !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) +{ + // FIXME: We should be able to check whether m_clipper.contains(object) - this doesn't work at the moment + // as resourceBoundingBox() has already created ClipperData, even if applyResource() returned false. + // Early exit, if this resource contains a child which references ourselves. + if (containsCyclicReference(node())) + return false; + + FloatPoint point = nodeAtPoint; + if (!SVGRenderSupport::pointInClippingArea(this, point)) + return false; + + if (static_cast(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(childNode)->isStyled() || !renderer) + continue; + if (!renderer->isRenderPath() && !renderer->isSVGText() && !renderer->isSVGShadowTreeRootContainer()) + continue; + IntPoint hitPoint; + HitTestResult result(hitPoint); + if (renderer->nodeAtFloatPoint(HitTestRequest(HitTestRequest::SVGClipContent), result, point, HitTestForeground)) + return true; + } + + return false; +} + +bool RenderSVGResourceClipper::childElementReferencesResource(const SVGRenderStyle* style, const String& referenceId) const +{ + if (!style->hasClipper()) + return false; + + return style->clipperResource() == referenceId; +} + +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(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)