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/*
* Copyright (C) 2007, 2008 Rob Buis <buis@kde.org>
* Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
* Copyright (C) 2007 Eric Seidel <eric@webkit.org>
* Copyright (C) 2009 Google, Inc. All rights reserved.
* Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
* Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
* Copyright (C) 2018 Adobe Systems Incorporated. All rights reserved.
* Copyright (C) 2022 Apple Inc. 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"
#include "SVGRenderingContext.h"
#include "BasicShapes.h"
#include "Frame.h"
#include "FrameView.h"
#include "RenderLayer.h"
#include "RenderSVGImage.h"
#include "RenderSVGResourceClipper.h"
#include "RenderSVGResourceFilter.h"
#include "RenderSVGResourceMasker.h"
#include "RenderView.h"
#include "SVGElementTypeHelpers.h"
#include "SVGGraphicsElement.h"
#include "SVGLengthContext.h"
#include "SVGResources.h"
#include "SVGResourcesCache.h"
#include <wtf/MathExtras.h>
namespace WebCore {
static inline bool isRenderingMaskImage(const RenderObject& object)
{
return object.view().frameView().paintBehavior().contains(PaintBehavior::RenderingSVGMask);
}
SVGRenderingContext::~SVGRenderingContext()
{
// Fast path if we don't need to restore anything.
if (!(m_renderingFlags & ActionsNeeded))
return;
ASSERT(m_renderer && m_paintInfo);
if (m_renderingFlags & EndFilterLayer) {
ASSERT(m_filter);
GraphicsContext* contextPtr = &m_paintInfo->context();
m_filter->postApplyResource(*m_renderer, contextPtr, { }, nullptr, nullptr);
m_paintInfo->setContext(*m_savedContext);
m_paintInfo->rect = m_savedPaintRect;
}
if (m_renderingFlags & EndOpacityLayer)
m_paintInfo->context().endTransparencyLayer();
if (m_renderingFlags & RestoreGraphicsContext)
m_paintInfo->context().restore();
}
void SVGRenderingContext::prepareToRenderSVGContent(RenderElement& renderer, PaintInfo& paintInfo, NeedsGraphicsContextSave needsGraphicsContextSave)
{
#ifndef NDEBUG
// This function must not be called twice!
ASSERT(!(m_renderingFlags & PrepareToRenderSVGContentWasCalled));
m_renderingFlags |= PrepareToRenderSVGContentWasCalled;
#endif
m_renderer = &renderer;
m_paintInfo = &paintInfo;
m_filter = nullptr;
// We need to save / restore the context even if the initialization failed.
if (needsGraphicsContextSave == SaveGraphicsContext) {
m_paintInfo->context().save();
m_renderingFlags |= RestoreGraphicsContext;
}
auto& style = m_renderer->style();
// Setup transparency layers before setting up SVG resources!
bool isRenderingMask = isRenderingMaskImage(*m_renderer);
// RenderLayer takes care of root opacity.
float opacity = (renderer.isLegacySVGRoot() || isRenderingMask) ? 1 : style.opacity();
bool hasBlendMode = style.hasBlendMode();
bool hasIsolation = style.hasIsolation();
bool isolateMaskForBlending = false;
#if ENABLE(CSS_COMPOSITING)
if (style.hasPositionedMask() && is<SVGGraphicsElement>(downcast<SVGElement>(*renderer.element()))) {
SVGGraphicsElement& graphicsElement = downcast<SVGGraphicsElement>(*renderer.element());
isolateMaskForBlending = graphicsElement.shouldIsolateBlending();
}
#endif
if (opacity < 1 || hasBlendMode || isolateMaskForBlending || hasIsolation) {
FloatRect repaintRect = m_renderer->repaintRectInLocalCoordinates();
m_paintInfo->context().clip(repaintRect);
if (opacity < 1 || hasBlendMode || isolateMaskForBlending || hasIsolation) {
if (hasBlendMode)
m_paintInfo->context().setCompositeOperation(m_paintInfo->context().compositeOperation(), style.blendMode());
m_paintInfo->context().beginTransparencyLayer(opacity);
if (hasBlendMode)
m_paintInfo->context().setCompositeOperation(m_paintInfo->context().compositeOperation(), BlendMode::Normal);
m_renderingFlags |= EndOpacityLayer;
}
}
PathOperation* clipPathOperation = style.clipPath();
bool hasCSSClipping = is<ShapePathOperation>(clipPathOperation) || is<BoxPathOperation>(clipPathOperation);
if (hasCSSClipping)
SVGRenderSupport::clipContextToCSSClippingArea(m_paintInfo->context(), renderer);
auto* resources = SVGResourcesCache::cachedResourcesForRenderer(*m_renderer);
if (!resources) {
if (style.hasReferenceFilterOnly())
return;
m_renderingFlags |= RenderingPrepared;
return;
}
if (!isRenderingMask) {
if (RenderSVGResourceMasker* masker = resources->masker()) {
GraphicsContext* contextPtr = &m_paintInfo->context();
bool result = masker->applyResource(*m_renderer, style, contextPtr, { });
m_paintInfo->setContext(*contextPtr);
if (!result)
return;
}
}
RenderSVGResourceClipper* clipper = resources->clipper();
if (!hasCSSClipping && clipper) {
GraphicsContext* contextPtr = &m_paintInfo->context();
bool result = clipper->applyResource(*m_renderer, style, contextPtr, { });
m_paintInfo->setContext(*contextPtr);
if (!result)
return;
}
if (!isRenderingMask) {
m_filter = resources->filter();
if (m_filter) {
m_savedContext = &m_paintInfo->context();
m_savedPaintRect = m_paintInfo->rect;
// Return with false here may mean that we don't need to draw the content
// (because it was either drawn before or empty) but we still need to apply the filter.
m_renderingFlags |= EndFilterLayer;
GraphicsContext* contextPtr = &m_paintInfo->context();
bool result = m_filter->applyResource(*m_renderer, style, contextPtr, { });
m_paintInfo->setContext(*contextPtr);
if (!result)
return;
// Since we're caching the resulting bitmap and do not invalidate it on repaint rect
// changes, we need to paint the whole filter region. Otherwise, elements not visible
// at the time of the initial paint (due to scrolling, window size, etc.) will never
// be drawn.
m_paintInfo->rect = IntRect(m_filter->drawingRegion(m_renderer));
}
}
m_renderingFlags |= RenderingPrepared;
}
static AffineTransform& currentContentTransformation()
{
static NeverDestroyed<AffineTransform> s_currentContentTransformation;
return s_currentContentTransformation;
}
float SVGRenderingContext::calculateScreenFontSizeScalingFactor(const RenderObject& renderer)
{
AffineTransform ctm = calculateTransformationToOutermostCoordinateSystem(renderer);
return narrowPrecisionToFloat(std::hypot(ctm.xScale(), ctm.yScale()) / sqrtOfTwoDouble);
}
AffineTransform SVGRenderingContext::calculateTransformationToOutermostCoordinateSystem(const RenderObject& renderer)
{
AffineTransform absoluteTransform = currentContentTransformation();
float deviceScaleFactor = renderer.document().deviceScaleFactor();
// Walk up the render tree, accumulating SVG transforms.
const RenderObject* ancestor = &renderer;
while (ancestor) {
absoluteTransform = ancestor->localToParentTransform() * absoluteTransform;
if (ancestor->isSVGRootOrLegacySVGRoot())
break;
ancestor = ancestor->parent();
}
// Continue walking up the layer tree, accumulating CSS transforms.
RenderLayer* layer = ancestor ? ancestor->enclosingLayer() : nullptr;
while (layer) {
if (TransformationMatrix* layerTransform = layer->transform())
absoluteTransform = layerTransform->toAffineTransform() * absoluteTransform;
// We can stop at compositing layers, to match the backing resolution.
if (layer->isComposited())
break;
layer = layer->parent();
}
absoluteTransform.scale(deviceScaleFactor);
return absoluteTransform;
}
void SVGRenderingContext::renderSubtreeToContext(GraphicsContext& context, RenderElement& item, const AffineTransform& subtreeContentTransformation)
{
// Rendering into a buffer implies we're being used for masking, clipping, patterns or filters. In each of these
// cases we don't want to paint the selection.
PaintInfo info(context, LayoutRect::infiniteRect(), PaintPhase::Foreground, PaintBehavior::SkipSelectionHighlight);
AffineTransform& contentTransformation = currentContentTransformation();
AffineTransform savedContentTransformation = contentTransformation;
contentTransformation = subtreeContentTransformation * contentTransformation;
ASSERT(!item.needsLayout());
item.paint(info, { });
contentTransformation = savedContentTransformation;
}
void SVGRenderingContext::clipToImageBuffer(GraphicsContext& context, const FloatRect& targetRect, const FloatSize& scale, RefPtr<ImageBuffer>& imageBuffer, bool safeToClear)
{
if (!imageBuffer)
return;
AffineTransform absoluteTransform;
absoluteTransform.scale(scale.width(), scale.height());
auto absoluteTargetRect = calculateImageBufferRect(targetRect, absoluteTransform);
// The mask image has been created in the absolute coordinate space, as the image should not be scaled.
// So the actual masking process has to be done in the absolute coordinate space as well.
context.concatCTM(valueOrDefault(absoluteTransform.inverse()));
context.clipToImageBuffer(*imageBuffer, absoluteTargetRect);
context.concatCTM(absoluteTransform);
// When nesting resources, with objectBoundingBox as content unit types, there's no use in caching the
// resulting image buffer as the parent resource already caches the result.
if (safeToClear && !currentContentTransformation().isIdentity())
imageBuffer = nullptr;
}
bool SVGRenderingContext::bufferForeground(RefPtr<ImageBuffer>& imageBuffer)
{
ASSERT(m_paintInfo);
ASSERT(is<RenderSVGImage>(*m_renderer));
FloatRect boundingBox = m_renderer->objectBoundingBox();
// Invalidate an existing buffer if the scale is not correct.
if (imageBuffer) {
AffineTransform transform = m_paintInfo->context().getCTM(GraphicsContext::DefinitelyIncludeDeviceScale);
IntSize expandedBoundingBox = expandedIntSize(boundingBox.size());
IntSize bufferSize(static_cast<int>(ceil(expandedBoundingBox.width() * transform.xScale())), static_cast<int>(ceil(expandedBoundingBox.height() * transform.yScale())));
if (bufferSize != imageBuffer->backendSize())
imageBuffer = nullptr;
}
// Create a new buffer and paint the foreground into it.
if (!imageBuffer) {
imageBuffer = m_paintInfo->context().createAlignedImageBuffer(expandedIntSize(boundingBox.size()));
if (!imageBuffer)
return false;
}
GraphicsContext& bufferedRenderingContext = imageBuffer->context();
bufferedRenderingContext.translate(-boundingBox.location());
PaintInfo bufferedInfo(*m_paintInfo);
bufferedInfo.setContext(bufferedRenderingContext);
downcast<RenderSVGImage>(*m_renderer).paintForeground(bufferedInfo);
m_paintInfo->context().drawImageBuffer(*imageBuffer, boundingBox);
return true;
}
}