Merge WebKit at r75993: Initial merge by git.

Change-Id: I602bbdc3974787a3b0450456a30a7868286921c3

1 files changed, 349 insertions, 0 deletions

diff --git a/Source/WebCore/rendering/svg/RenderSVGResourceClipper.cpp b/Source/WebCore/rendering/svg/RenderSVGResourceClipper.cpp
new file mode 100644
index 0000000..c57f8b0
--- /dev/null
+++ b/Source/WebCore/rendering/svg/RenderSVGResourceClipper.cpp
@@ -0,0 +1,349 @@
+/*
+ * 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)