/*
* Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
* 2008 Eric Seidel <eric@webkit.org>
* 2008 Dirk Schulze <krit@webkit.org>
* Copyright (C) Research In Motion Limited 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 "RenderSVGResourceGradient.h"
#include "GradientAttributes.h"
#include "GraphicsContext.h"
#include "SVGRenderSupport.h"
#include <wtf/UnusedParam.h>
namespace WebCore {
RenderSVGResourceGradient::RenderSVGResourceGradient(SVGGradientElement* node)
: RenderSVGResourceContainer(node)
#if PLATFORM(CG)
, m_savedContext(0)
#endif
{
}
RenderSVGResourceGradient::~RenderSVGResourceGradient()
{
deleteAllValues(m_gradient);
m_gradient.clear();
}
void RenderSVGResourceGradient::invalidateClients()
{
const HashMap<RenderObject*, GradientData*>::const_iterator end = m_gradient.end();
for (HashMap<RenderObject*, GradientData*>::const_iterator it = m_gradient.begin(); it != end; ++it)
markForLayoutAndResourceInvalidation(it->first, false);
deleteAllValues(m_gradient);
m_gradient.clear();
}
void RenderSVGResourceGradient::invalidateClient(RenderObject* object)
{
ASSERT(object);
if (!m_gradient.contains(object))
return;
delete m_gradient.take(object);
markForLayoutAndResourceInvalidation(object, false);
}
#if PLATFORM(CG)
static inline AffineTransform absoluteTransformFromContext(GraphicsContext* context)
{
// Extract current transformation matrix used in the original context. Note that this coordinate
// system is flipped compared to SVGs internal coordinate system, done in WebKit level. Fix
// this transformation by flipping the y component.
return context->getCTM() * AffineTransform().flipY();
}
static inline bool createMaskAndSwapContextForTextGradient(GraphicsContext*& context,
GraphicsContext*& savedContext,
OwnPtr<ImageBuffer>& imageBuffer,
const RenderObject* object)
{
const RenderObject* textRootBlock = SVGRenderSupport::findTextRootObject(object);
AffineTransform transform(absoluteTransformFromContext(context));
FloatRect maskAbsoluteBoundingBox = transform.mapRect(textRootBlock->repaintRectInLocalCoordinates());
IntRect maskImageRect = enclosingIntRect(maskAbsoluteBoundingBox);
if (maskImageRect.isEmpty())
return false;
// Allocate an image buffer as big as the absolute unclipped size of the object
OwnPtr<ImageBuffer> maskImage = ImageBuffer::create(maskImageRect.size());
if (!maskImage)
return false;
GraphicsContext* maskImageContext = maskImage->context();
// Transform the mask image coordinate system to absolute screen coordinates
maskImageContext->translate(-maskAbsoluteBoundingBox.x(), -maskAbsoluteBoundingBox.y());
maskImageContext->concatCTM(transform);
imageBuffer = maskImage.release();
savedContext = context;
context = maskImageContext;
return true;
}
static inline AffineTransform clipToTextMask(GraphicsContext* context,
OwnPtr<ImageBuffer>& imageBuffer,
const RenderObject* object,
GradientData* gradientData)
{
const RenderObject* textRootBlock = SVGRenderSupport::findTextRootObject(object);
// The mask image has been created in the device coordinate space, as the image should not be scaled.
// So the actual masking process has to be done in the device coordinate space as well.
AffineTransform transform(absoluteTransformFromContext(context));
context->concatCTM(transform.inverse());
context->clipToImageBuffer(transform.mapRect(textRootBlock->repaintRectInLocalCoordinates()), imageBuffer.get());
context->concatCTM(transform);
AffineTransform matrix;
if (gradientData->boundingBoxMode) {
FloatRect maskBoundingBox = textRootBlock->objectBoundingBox();
matrix.translate(maskBoundingBox.x(), maskBoundingBox.y());
matrix.scaleNonUniform(maskBoundingBox.width(), maskBoundingBox.height());
}
matrix.multLeft(gradientData->transform);
return matrix;
}
#endif
bool RenderSVGResourceGradient::applyResource(RenderObject* object, RenderStyle* style, GraphicsContext*& context, unsigned short resourceMode)
{
ASSERT(object);
ASSERT(style);
ASSERT(context);
ASSERT(resourceMode != ApplyToDefaultMode);
// Be sure to synchronize all SVG properties on the gradientElement _before_ processing any further.
// Otherwhise the call to collectGradientAttributes() in createTileImage(), may cause the SVG DOM property
// synchronization to kick in, which causes invalidateClients() to be called, which in turn deletes our
// GradientData object! Leaving out the line below will cause svg/dynamic-updates/SVG*GradientElement-svgdom* to crash.
SVGGradientElement* gradientElement = static_cast<SVGGradientElement*>(node());
if (!gradientElement)
return false;
gradientElement->updateAnimatedSVGAttribute(anyQName());
if (!m_gradient.contains(object))
m_gradient.set(object, new GradientData);
GradientData* gradientData = m_gradient.get(object);
bool isPaintingText = resourceMode & ApplyToTextMode;
// Create gradient object
if (!gradientData->gradient) {
buildGradient(gradientData, gradientElement);
// CG platforms will handle the gradient space transform for text after applying the
// resource, so don't apply it here. For non-CG platforms, we want the text bounding
// box applied to the gradient space transform now, so the gradient shader can use it.
#if PLATFORM(CG)
if (gradientData->boundingBoxMode && !isPaintingText) {
#else
if (gradientData->boundingBoxMode) {
#endif
FloatRect objectBoundingBox = object->objectBoundingBox();
gradientData->userspaceTransform.translate(objectBoundingBox.x(), objectBoundingBox.y());
gradientData->userspaceTransform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
}
gradientData->userspaceTransform.multLeft(gradientData->transform);
gradientData->gradient->setGradientSpaceTransform(gradientData->userspaceTransform);
}
if (!gradientData->gradient)
return false;
// Draw gradient
context->save();
if (isPaintingText) {
#if PLATFORM(CG)
if (!createMaskAndSwapContextForTextGradient(context, m_savedContext, m_imageBuffer, object)) {
context->restore();
return false;
}
#endif
context->setTextDrawingMode(resourceMode & ApplyToFillMode ? cTextFill : cTextStroke);
}
const SVGRenderStyle* svgStyle = style->svgStyle();
ASSERT(svgStyle);
if (resourceMode & ApplyToFillMode) {
context->setAlpha(svgStyle->fillOpacity());
context->setFillGradient(gradientData->gradient);
context->setFillRule(svgStyle->fillRule());
} else if (resourceMode & ApplyToStrokeMode) {
if (svgStyle->vectorEffect() == VE_NON_SCALING_STROKE)
gradientData->gradient->setGradientSpaceTransform(transformOnNonScalingStroke(object, gradientData->userspaceTransform));
context->setAlpha(svgStyle->strokeOpacity());
context->setStrokeGradient(gradientData->gradient);
SVGRenderSupport::applyStrokeStyleToContext(context, style, object);
}
return true;
}
void RenderSVGResourceGradient::postApplyResource(RenderObject* object, GraphicsContext*& context, unsigned short resourceMode)
{
ASSERT(context);
ASSERT(resourceMode != ApplyToDefaultMode);
if (resourceMode & ApplyToTextMode) {
#if PLATFORM(CG)
// CG requires special handling for gradient on text
if (m_savedContext && m_gradient.contains(object)) {
GradientData* gradientData = m_gradient.get(object);
// Restore on-screen drawing context
context = m_savedContext;
m_savedContext = 0;
gradientData->gradient->setGradientSpaceTransform(clipToTextMask(context, m_imageBuffer, object, gradientData));
context->setFillGradient(gradientData->gradient);
const RenderObject* textRootBlock = SVGRenderSupport::findTextRootObject(object);
context->fillRect(textRootBlock->repaintRectInLocalCoordinates());
m_imageBuffer.clear();
}
#else
UNUSED_PARAM(object);
#endif
} else {
if (resourceMode & ApplyToFillMode)
context->fillPath();
else if (resourceMode & ApplyToStrokeMode)
context->strokePath();
}
context->restore();
}
void RenderSVGResourceGradient::addStops(GradientData* gradientData, const Vector<Gradient::ColorStop>& stops) const
{
ASSERT(gradientData->gradient);
const Vector<Gradient::ColorStop>::const_iterator end = stops.end();
for (Vector<Gradient::ColorStop>::const_iterator it = stops.begin(); it != end; ++it)
gradientData->gradient->addColorStop(*it);
}
}
#endif