1/*
2 * Copyright (C) 2007, 2008 Rob Buis <buis@kde.org>
3 * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
4 * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
5 * Copyright (C) 2009 Google, Inc. All rights reserved.
6 * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
7 * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
8 * Copyright (C) 2018 Adobe Systems Incorporated. All rights reserved.
9 *
10 * This library is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Library General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Library General Public License for more details.
19 *
20 * You should have received a copy of the GNU Library General Public License
21 * along with this library; see the file COPYING.LIB. If not, write to
22 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
23 * Boston, MA 02110-1301, USA.
24 */
25
26#include "config.h"
27#include "SVGRenderingContext.h"
28
29#include "BasicShapes.h"
30#include "Frame.h"
31#include "FrameView.h"
32#include "RenderLayer.h"
33#include "RenderSVGImage.h"
34#include "RenderSVGResourceClipper.h"
35#include "RenderSVGResourceFilter.h"
36#include "RenderSVGResourceMasker.h"
37#include "RenderView.h"
38#include "SVGLengthContext.h"
39#include "SVGResources.h"
40#include "SVGResourcesCache.h"
41
42namespace WebCore {
43
44static inline bool isRenderingMaskImage(const RenderObject& object)
45{
46 return object.view().frameView().paintBehavior().contains(PaintBehavior::RenderingSVGMask);
47}
48
49SVGRenderingContext::~SVGRenderingContext()
50{
51 // Fast path if we don't need to restore anything.
52 if (!(m_renderingFlags & ActionsNeeded))
53 return;
54
55 ASSERT(m_renderer && m_paintInfo);
56
57 if (m_renderingFlags & EndFilterLayer) {
58 ASSERT(m_filter);
59 GraphicsContext* contextPtr = &m_paintInfo->context();
60 m_filter->postApplyResource(*m_renderer, contextPtr, { }, nullptr, nullptr);
61 m_paintInfo->setContext(*m_savedContext);
62 m_paintInfo->rect = m_savedPaintRect;
63 }
64
65 if (m_renderingFlags & EndOpacityLayer)
66 m_paintInfo->context().endTransparencyLayer();
67
68 if (m_renderingFlags & EndShadowLayer)
69 m_paintInfo->context().endTransparencyLayer();
70
71 if (m_renderingFlags & RestoreGraphicsContext)
72 m_paintInfo->context().restore();
73}
74
75void SVGRenderingContext::prepareToRenderSVGContent(RenderElement& renderer, PaintInfo& paintInfo, NeedsGraphicsContextSave needsGraphicsContextSave)
76{
77#ifndef NDEBUG
78 // This function must not be called twice!
79 ASSERT(!(m_renderingFlags & PrepareToRenderSVGContentWasCalled));
80 m_renderingFlags |= PrepareToRenderSVGContentWasCalled;
81#endif
82
83 m_renderer = &renderer;
84 m_paintInfo = &paintInfo;
85 m_filter = nullptr;
86
87 // We need to save / restore the context even if the initialization failed.
88 if (needsGraphicsContextSave == SaveGraphicsContext) {
89 m_paintInfo->context().save();
90 m_renderingFlags |= RestoreGraphicsContext;
91 }
92
93 auto& style = m_renderer->style();
94
95 const SVGRenderStyle& svgStyle = style.svgStyle();
96
97 // Setup transparency layers before setting up SVG resources!
98 bool isRenderingMask = isRenderingMaskImage(*m_renderer);
99 // RenderLayer takes care of root opacity.
100 float opacity = (renderer.isSVGRoot() || isRenderingMask) ? 1 : style.opacity();
101 const ShadowData* shadow = svgStyle.shadow();
102 bool hasBlendMode = style.hasBlendMode();
103 bool hasIsolation = style.hasIsolation();
104 bool isolateMaskForBlending = false;
105
106#if ENABLE(CSS_COMPOSITING)
107 if (svgStyle.hasMasker() && is<SVGGraphicsElement>(downcast<SVGElement>(*renderer.element()))) {
108 SVGGraphicsElement& graphicsElement = downcast<SVGGraphicsElement>(*renderer.element());
109 isolateMaskForBlending = graphicsElement.shouldIsolateBlending();
110 }
111#endif
112
113 if (opacity < 1 || shadow || hasBlendMode || isolateMaskForBlending || hasIsolation) {
114 FloatRect repaintRect = m_renderer->repaintRectInLocalCoordinates();
115 m_paintInfo->context().clip(repaintRect);
116
117 if (opacity < 1 || hasBlendMode || isolateMaskForBlending || hasIsolation) {
118
119 if (hasBlendMode)
120 m_paintInfo->context().setCompositeOperation(m_paintInfo->context().compositeOperation(), style.blendMode());
121
122 m_paintInfo->context().beginTransparencyLayer(opacity);
123
124 if (hasBlendMode)
125 m_paintInfo->context().setCompositeOperation(m_paintInfo->context().compositeOperation(), BlendMode::Normal);
126
127 m_renderingFlags |= EndOpacityLayer;
128 }
129
130 if (shadow) {
131 m_paintInfo->context().setShadow(IntSize(roundToInt(shadow->x()), roundToInt(shadow->y())), shadow->radius(), shadow->color());
132 m_paintInfo->context().beginTransparencyLayer(1);
133 m_renderingFlags |= EndShadowLayer;
134 }
135 }
136
137 ClipPathOperation* clipPathOperation = style.clipPath();
138 bool hasCSSClipping = is<ShapeClipPathOperation>(clipPathOperation) || is<BoxClipPathOperation>(clipPathOperation);
139 if (hasCSSClipping)
140 SVGRenderSupport::clipContextToCSSClippingArea(m_paintInfo->context(), renderer);
141
142 auto* resources = SVGResourcesCache::cachedResourcesForRenderer(*m_renderer);
143 if (!resources) {
144 if (style.hasReferenceFilterOnly())
145 return;
146
147 m_renderingFlags |= RenderingPrepared;
148 return;
149 }
150
151 if (!isRenderingMask) {
152 if (RenderSVGResourceMasker* masker = resources->masker()) {
153 GraphicsContext* contextPtr = &m_paintInfo->context();
154 bool result = masker->applyResource(*m_renderer, style, contextPtr, { });
155 m_paintInfo->setContext(*contextPtr);
156 if (!result)
157 return;
158 }
159 }
160
161 RenderSVGResourceClipper* clipper = resources->clipper();
162 if (!hasCSSClipping && clipper) {
163 GraphicsContext* contextPtr = &m_paintInfo->context();
164 bool result = clipper->applyResource(*m_renderer, style, contextPtr, { });
165 m_paintInfo->setContext(*contextPtr);
166 if (!result)
167 return;
168 }
169
170 if (!isRenderingMask) {
171 m_filter = resources->filter();
172 if (m_filter) {
173 m_savedContext = &m_paintInfo->context();
174 m_savedPaintRect = m_paintInfo->rect;
175 // Return with false here may mean that we don't need to draw the content
176 // (because it was either drawn before or empty) but we still need to apply the filter.
177 m_renderingFlags |= EndFilterLayer;
178 GraphicsContext* contextPtr = &m_paintInfo->context();
179 bool result = m_filter->applyResource(*m_renderer, style, contextPtr, { });
180 m_paintInfo->setContext(*contextPtr);
181 if (!result)
182 return;
183
184 // Since we're caching the resulting bitmap and do not invalidate it on repaint rect
185 // changes, we need to paint the whole filter region. Otherwise, elements not visible
186 // at the time of the initial paint (due to scrolling, window size, etc.) will never
187 // be drawn.
188 m_paintInfo->rect = IntRect(m_filter->drawingRegion(m_renderer));
189 }
190 }
191
192 m_renderingFlags |= RenderingPrepared;
193}
194
195static AffineTransform& currentContentTransformation()
196{
197 static NeverDestroyed<AffineTransform> s_currentContentTransformation;
198 return s_currentContentTransformation;
199}
200
201float SVGRenderingContext::calculateScreenFontSizeScalingFactor(const RenderObject& renderer)
202{
203 AffineTransform ctm = calculateTransformationToOutermostCoordinateSystem(renderer);
204 return narrowPrecisionToFloat(sqrt((pow(ctm.xScale(), 2) + pow(ctm.yScale(), 2)) / 2));
205}
206
207AffineTransform SVGRenderingContext::calculateTransformationToOutermostCoordinateSystem(const RenderObject& renderer)
208{
209 AffineTransform absoluteTransform = currentContentTransformation();
210
211 float deviceScaleFactor = renderer.document().deviceScaleFactor();
212 // Walk up the render tree, accumulating SVG transforms.
213 const RenderObject* ancestor = &renderer;
214 while (ancestor) {
215 absoluteTransform = ancestor->localToParentTransform() * absoluteTransform;
216 if (ancestor->isSVGRoot())
217 break;
218 ancestor = ancestor->parent();
219 }
220
221 // Continue walking up the layer tree, accumulating CSS transforms.
222 RenderLayer* layer = ancestor ? ancestor->enclosingLayer() : nullptr;
223 while (layer) {
224 if (TransformationMatrix* layerTransform = layer->transform())
225 absoluteTransform = layerTransform->toAffineTransform() * absoluteTransform;
226
227 // We can stop at compositing layers, to match the backing resolution.
228 if (layer->isComposited())
229 break;
230
231 layer = layer->parent();
232 }
233
234 absoluteTransform.scale(deviceScaleFactor);
235 return absoluteTransform;
236}
237
238std::unique_ptr<ImageBuffer> SVGRenderingContext::createImageBuffer(const FloatRect& targetRect, const AffineTransform& absoluteTransform, ColorSpace colorSpace, RenderingMode renderingMode, const GraphicsContext* context)
239{
240 IntRect paintRect = calculateImageBufferRect(targetRect, absoluteTransform);
241 // Don't create empty ImageBuffers.
242 if (paintRect.isEmpty())
243 return nullptr;
244
245 FloatSize scale;
246 FloatSize clampedSize = ImageBuffer::clampedSize(paintRect.size(), scale);
247
248#if USE(DIRECT2D)
249 auto imageBuffer = ImageBuffer::create(clampedSize, renderingMode, context, 1, colorSpace);
250#else
251 UNUSED_PARAM(context);
252 auto imageBuffer = ImageBuffer::create(clampedSize, renderingMode, 1, colorSpace);
253#endif
254 if (!imageBuffer)
255 return nullptr;
256
257 AffineTransform transform;
258 transform.scale(scale).translate(-paintRect.location()).multiply(absoluteTransform);
259
260 GraphicsContext& imageContext = imageBuffer->context();
261 imageContext.concatCTM(transform);
262
263 return imageBuffer;
264}
265
266std::unique_ptr<ImageBuffer> SVGRenderingContext::createImageBuffer(const FloatRect& targetRect, const FloatRect& clampedRect, ColorSpace colorSpace, RenderingMode renderingMode, const GraphicsContext* context)
267{
268 IntSize clampedSize = roundedIntSize(clampedRect.size());
269 FloatSize unclampedSize = roundedIntSize(targetRect.size());
270
271 // Don't create empty ImageBuffers.
272 if (clampedSize.isEmpty())
273 return nullptr;
274
275#if USE(DIRECT2D)
276 auto imageBuffer = ImageBuffer::create(clampedSize, renderingMode, context, 1, colorSpace);
277#else
278 UNUSED_PARAM(context);
279 auto imageBuffer = ImageBuffer::create(clampedSize, renderingMode, 1, colorSpace);
280#endif
281 if (!imageBuffer)
282 return nullptr;
283
284 GraphicsContext& imageContext = imageBuffer->context();
285
286 // Compensate rounding effects, as the absolute target rect is using floating-point numbers and the image buffer size is integer.
287 imageContext.scale(unclampedSize / targetRect.size());
288
289 return imageBuffer;
290}
291
292void SVGRenderingContext::renderSubtreeToImageBuffer(ImageBuffer* image, RenderElement& item, const AffineTransform& subtreeContentTransformation)
293{
294 ASSERT(image);
295
296 // Rendering into a buffer implies we're being used for masking, clipping, patterns or filters. In each of these
297 // cases we don't want to paint the selection.
298 PaintInfo info(image->context(), LayoutRect::infiniteRect(), PaintPhase::Foreground, PaintBehavior::SkipSelectionHighlight);
299
300 AffineTransform& contentTransformation = currentContentTransformation();
301 AffineTransform savedContentTransformation = contentTransformation;
302 contentTransformation = subtreeContentTransformation * contentTransformation;
303
304 ASSERT(!item.needsLayout());
305 item.paint(info, { });
306
307 contentTransformation = savedContentTransformation;
308}
309
310void SVGRenderingContext::clipToImageBuffer(GraphicsContext& context, const AffineTransform& absoluteTransform, const FloatRect& targetRect, std::unique_ptr<ImageBuffer>& imageBuffer, bool safeToClear)
311{
312 if (!imageBuffer)
313 return;
314
315 FloatRect absoluteTargetRect = calculateImageBufferRect(targetRect, absoluteTransform);
316
317 // The mask image has been created in the absolute coordinate space, as the image should not be scaled.
318 // So the actual masking process has to be done in the absolute coordinate space as well.
319 context.concatCTM(absoluteTransform.inverse().valueOr(AffineTransform()));
320 context.clipToImageBuffer(*imageBuffer, absoluteTargetRect);
321 context.concatCTM(absoluteTransform);
322
323 // When nesting resources, with objectBoundingBox as content unit types, there's no use in caching the
324 // resulting image buffer as the parent resource already caches the result.
325 if (safeToClear && !currentContentTransformation().isIdentity())
326 imageBuffer.reset();
327}
328
329void SVGRenderingContext::clear2DRotation(AffineTransform& transform)
330{
331 AffineTransform::DecomposedType decomposition;
332 transform.decompose(decomposition);
333 decomposition.angle = 0;
334 transform.recompose(decomposition);
335}
336
337bool SVGRenderingContext::bufferForeground(std::unique_ptr<ImageBuffer>& imageBuffer)
338{
339 ASSERT(m_paintInfo);
340 ASSERT(is<RenderSVGImage>(*m_renderer));
341 FloatRect boundingBox = m_renderer->objectBoundingBox();
342
343 // Invalidate an existing buffer if the scale is not correct.
344 if (imageBuffer) {
345 AffineTransform transform = m_paintInfo->context().getCTM(GraphicsContext::DefinitelyIncludeDeviceScale);
346 IntSize expandedBoundingBox = expandedIntSize(boundingBox.size());
347 IntSize bufferSize(static_cast<int>(ceil(expandedBoundingBox.width() * transform.xScale())), static_cast<int>(ceil(expandedBoundingBox.height() * transform.yScale())));
348 if (bufferSize != imageBuffer->internalSize())
349 imageBuffer.reset();
350 }
351
352 // Create a new buffer and paint the foreground into it.
353 if (!imageBuffer) {
354 if ((imageBuffer = ImageBuffer::createCompatibleBuffer(expandedIntSize(boundingBox.size()), ColorSpaceSRGB, m_paintInfo->context()))) {
355 GraphicsContext& bufferedRenderingContext = imageBuffer->context();
356 bufferedRenderingContext.translate(-boundingBox.location());
357 PaintInfo bufferedInfo(*m_paintInfo);
358 bufferedInfo.setContext(bufferedRenderingContext);
359 downcast<RenderSVGImage>(*m_renderer).paintForeground(bufferedInfo);
360 } else
361 return false;
362 }
363
364 m_paintInfo->context().drawImageBuffer(*imageBuffer, boundingBox);
365 return true;
366}
367
368}
369