--- /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 <zimmermann@kde.org>
+ * 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 "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 <wtf/UnusedParam.h>
+
+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<RenderObject*, ClipperData*>::const_iterator end = m_clipper.end();
+ for (HashMap<RenderObject*, ClipperData*>::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<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()) {
+ 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<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->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<RenderSVGResourceClipper>(this->document(), style()->svgStyle()->clipperResource())) {
+ if (!clipper->applyClippingToContext(this, objectBoundingBox, repaintRect, maskContext)) {
+ maskContext->restore();
+ return false;
+ }
+ }
+
+ SVGClipPathElement* clipPath = static_cast<SVGClipPathElement*>(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<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->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<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 hsve to pass the <use> 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<SVGElement*>(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<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->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<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)