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1 /*
2  * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
3  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Library General Public
7  * License as published by the Free Software Foundation; either
8  * version 2 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Library General Public License for more details.
14  *
15  * You should have received a copy of the GNU Library General Public License
16  * along with this library; see the file COPYING.LIB.  If not, write to
17  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18  * Boston, MA 02110-1301, USA.
19  */
20 
21 #include "config.h"
22 
23 #include "core/rendering/svg/RenderSVGResourcePattern.h"
24 
25 #include "core/rendering/svg/SVGRenderSupport.h"
26 #include "core/rendering/svg/SVGRenderingContext.h"
27 #include "core/svg/SVGFitToViewBox.h"
28 #include "platform/graphics/GraphicsContext.h"
29 
30 namespace WebCore {
31 
32 const RenderSVGResourceType RenderSVGResourcePattern::s_resourceType = PatternResourceType;
33 
RenderSVGResourcePattern(SVGPatternElement * node)34 RenderSVGResourcePattern::RenderSVGResourcePattern(SVGPatternElement* node)
35     : RenderSVGResourceContainer(node)
36     , m_shouldCollectPatternAttributes(true)
37 {
38 }
39 
removeAllClientsFromCache(bool markForInvalidation)40 void RenderSVGResourcePattern::removeAllClientsFromCache(bool markForInvalidation)
41 {
42     m_patternMap.clear();
43     m_shouldCollectPatternAttributes = true;
44     markAllClientsForInvalidation(markForInvalidation ? RepaintInvalidation : ParentOnlyInvalidation);
45 }
46 
removeClientFromCache(RenderObject * client,bool markForInvalidation)47 void RenderSVGResourcePattern::removeClientFromCache(RenderObject* client, bool markForInvalidation)
48 {
49     ASSERT(client);
50     m_patternMap.remove(client);
51     markClientForInvalidation(client, markForInvalidation ? RepaintInvalidation : ParentOnlyInvalidation);
52 }
53 
buildPattern(RenderObject * object,unsigned short resourceMode)54 PatternData* RenderSVGResourcePattern::buildPattern(RenderObject* object, unsigned short resourceMode)
55 {
56     ASSERT(object);
57     PatternData* currentData = m_patternMap.get(object);
58     if (currentData && currentData->pattern)
59         return currentData;
60 
61     SVGPatternElement* patternElement = toSVGPatternElement(element());
62     if (!patternElement)
63         return 0;
64 
65     if (m_shouldCollectPatternAttributes) {
66         patternElement->synchronizeAnimatedSVGAttribute(anyQName());
67 
68         m_attributes = PatternAttributes();
69         patternElement->collectPatternAttributes(m_attributes);
70         m_shouldCollectPatternAttributes = false;
71     }
72 
73     // If we couldn't determine the pattern content element root, stop here.
74     if (!m_attributes.patternContentElement())
75         return 0;
76 
77     // An empty viewBox disables rendering.
78     if (m_attributes.hasViewBox() && m_attributes.viewBox().isEmpty())
79         return 0;
80 
81     // Compute all necessary transformations to build the tile image & the pattern.
82     FloatRect tileBoundaries;
83     AffineTransform tileImageTransform;
84     if (!buildTileImageTransform(object, m_attributes, patternElement, tileBoundaries, tileImageTransform))
85         return 0;
86 
87     AffineTransform absoluteTransformIgnoringRotation;
88     SVGRenderingContext::calculateDeviceSpaceTransformation(object, absoluteTransformIgnoringRotation);
89 
90     // Ignore 2D rotation, as it doesn't affect the size of the tile.
91     SVGRenderingContext::clear2DRotation(absoluteTransformIgnoringRotation);
92     FloatRect absoluteTileBoundaries = absoluteTransformIgnoringRotation.mapRect(tileBoundaries);
93 
94     // Scale the tile size to match the scale level of the patternTransform.
95     absoluteTileBoundaries.scale(static_cast<float>(m_attributes.patternTransform().xScale()),
96         static_cast<float>(m_attributes.patternTransform().yScale()));
97 
98     // Build tile image.
99     OwnPtr<ImageBuffer> tileImage = createTileImage(m_attributes, tileBoundaries, absoluteTileBoundaries, tileImageTransform);
100     if (!tileImage)
101         return 0;
102 
103     RefPtr<Image> copiedImage = tileImage->copyImage(CopyBackingStore);
104     if (!copiedImage)
105         return 0;
106 
107     // Build pattern.
108     OwnPtr<PatternData> patternData = adoptPtr(new PatternData);
109     patternData->pattern = Pattern::create(copiedImage, true, true);
110 
111     // Compute pattern space transformation.
112     const IntSize tileImageSize = tileImage->size();
113     patternData->transform.translate(tileBoundaries.x(), tileBoundaries.y());
114     patternData->transform.scale(tileBoundaries.width() / tileImageSize.width(), tileBoundaries.height() / tileImageSize.height());
115 
116     AffineTransform patternTransform = m_attributes.patternTransform();
117     if (!patternTransform.isIdentity())
118         patternData->transform = patternTransform * patternData->transform;
119 
120     // Various calls above may trigger invalidations in some fringe cases (ImageBuffer allocation
121     // failures in the SVG image cache for example). To avoid having our PatternData deleted by
122     // removeAllClientsFromCache(), we only make it visible in the cache at the very end.
123     return m_patternMap.set(object, patternData.release()).storedValue->value.get();
124 }
125 
applyResource(RenderObject * object,RenderStyle * style,GraphicsContext * & context,unsigned short resourceMode)126 bool RenderSVGResourcePattern::applyResource(RenderObject* object, RenderStyle* style, GraphicsContext*& context, unsigned short resourceMode)
127 {
128     ASSERT(object);
129     ASSERT(style);
130     ASSERT(context);
131     ASSERT(resourceMode != ApplyToDefaultMode);
132 
133     clearInvalidationMask();
134 
135     // Spec: When the geometry of the applicable element has no width or height and objectBoundingBox is specified,
136     // then the given effect (e.g. a gradient or a filter) will be ignored.
137     FloatRect objectBoundingBox = object->objectBoundingBox();
138     if (m_attributes.patternUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX && objectBoundingBox.isEmpty())
139         return false;
140 
141     PatternData* patternData = buildPattern(object, resourceMode);
142     if (!patternData)
143         return false;
144 
145     const SVGRenderStyle* svgStyle = style->svgStyle();
146     ASSERT(svgStyle);
147 
148     AffineTransform computedPatternSpaceTransform = computeResourceSpaceTransform(object, patternData->transform, svgStyle, resourceMode);
149     patternData->pattern->setPatternSpaceTransform(computedPatternSpaceTransform);
150 
151     // Draw pattern
152     context->save();
153 
154     if (resourceMode & ApplyToFillMode) {
155         context->setAlphaAsFloat(svgStyle->fillOpacity());
156         context->setFillPattern(patternData->pattern);
157         context->setFillRule(svgStyle->fillRule());
158     } else if (resourceMode & ApplyToStrokeMode) {
159         context->setAlphaAsFloat(svgStyle->strokeOpacity());
160         context->setStrokePattern(patternData->pattern);
161         SVGRenderSupport::applyStrokeStyleToContext(context, style, object);
162     }
163 
164     if (resourceMode & ApplyToTextMode) {
165         if (resourceMode & ApplyToFillMode)
166             context->setTextDrawingMode(TextModeFill);
167         else if (resourceMode & ApplyToStrokeMode)
168             context->setTextDrawingMode(TextModeStroke);
169     }
170 
171     return true;
172 }
173 
postApplyResource(RenderObject *,GraphicsContext * & context,unsigned short resourceMode,const Path * path,const RenderSVGShape * shape)174 void RenderSVGResourcePattern::postApplyResource(RenderObject*, GraphicsContext*& context, unsigned short resourceMode, const Path* path, const RenderSVGShape* shape)
175 {
176     ASSERT(context);
177     ASSERT(resourceMode != ApplyToDefaultMode);
178 
179     if (resourceMode & ApplyToFillMode) {
180         if (path)
181             context->fillPath(*path);
182         else if (shape)
183             shape->fillShape(context);
184     }
185     if (resourceMode & ApplyToStrokeMode) {
186         if (path)
187             context->strokePath(*path);
188         else if (shape)
189             shape->strokeShape(context);
190     }
191 
192     context->restore();
193 }
194 
calculatePatternBoundaries(const PatternAttributes & attributes,const FloatRect & objectBoundingBox,const SVGPatternElement * patternElement)195 static inline FloatRect calculatePatternBoundaries(const PatternAttributes& attributes,
196                                                    const FloatRect& objectBoundingBox,
197                                                    const SVGPatternElement* patternElement)
198 {
199     ASSERT(patternElement);
200     return SVGLengthContext::resolveRectangle(patternElement, attributes.patternUnits(), objectBoundingBox, attributes.x(), attributes.y(), attributes.width(), attributes.height());
201 }
202 
buildTileImageTransform(RenderObject * renderer,const PatternAttributes & attributes,const SVGPatternElement * patternElement,FloatRect & patternBoundaries,AffineTransform & tileImageTransform) const203 bool RenderSVGResourcePattern::buildTileImageTransform(RenderObject* renderer,
204                                                        const PatternAttributes& attributes,
205                                                        const SVGPatternElement* patternElement,
206                                                        FloatRect& patternBoundaries,
207                                                        AffineTransform& tileImageTransform) const
208 {
209     ASSERT(renderer);
210     ASSERT(patternElement);
211 
212     FloatRect objectBoundingBox = renderer->objectBoundingBox();
213     patternBoundaries = calculatePatternBoundaries(attributes, objectBoundingBox, patternElement);
214     if (patternBoundaries.width() <= 0 || patternBoundaries.height() <= 0)
215         return false;
216 
217     AffineTransform viewBoxCTM = SVGFitToViewBox::viewBoxToViewTransform(attributes.viewBox(), attributes.preserveAspectRatio(), patternBoundaries.width(), patternBoundaries.height());
218 
219     // Apply viewBox/objectBoundingBox transformations.
220     if (!viewBoxCTM.isIdentity())
221         tileImageTransform = viewBoxCTM;
222     else if (attributes.patternContentUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX)
223         tileImageTransform.scale(objectBoundingBox.width(), objectBoundingBox.height());
224 
225     return true;
226 }
227 
createTileImage(const PatternAttributes & attributes,const FloatRect & tileBoundaries,const FloatRect & absoluteTileBoundaries,const AffineTransform & tileImageTransform) const228 PassOwnPtr<ImageBuffer> RenderSVGResourcePattern::createTileImage(const PatternAttributes& attributes,
229                                                                   const FloatRect& tileBoundaries,
230                                                                   const FloatRect& absoluteTileBoundaries,
231                                                                   const AffineTransform& tileImageTransform) const
232 {
233     FloatRect clampedAbsoluteTileBoundaries = SVGRenderingContext::clampedAbsoluteTargetRect(absoluteTileBoundaries);
234 
235     IntSize imageSize(roundedIntSize(clampedAbsoluteTileBoundaries.size()));
236     if (imageSize.isEmpty())
237         return nullptr;
238     OwnPtr<ImageBuffer> tileImage = ImageBuffer::create(imageSize);
239     if (!tileImage)
240         return nullptr;
241 
242     GraphicsContext* tileImageContext = tileImage->context();
243     ASSERT(tileImageContext);
244     IntSize unclampedImageSize(roundedIntSize(absoluteTileBoundaries.size()));
245     tileImageContext->scale(unclampedImageSize.width() / absoluteTileBoundaries.width(), unclampedImageSize.height() / absoluteTileBoundaries.height());
246 
247     // The image buffer represents the final rendered size, so the content has to be scaled (to avoid pixelation).
248     tileImageContext->scale(
249         clampedAbsoluteTileBoundaries.width() / tileBoundaries.width(),
250         clampedAbsoluteTileBoundaries.height() / tileBoundaries.height());
251 
252     // Apply tile image transformations.
253     if (!tileImageTransform.isIdentity())
254         tileImageContext->concatCTM(tileImageTransform);
255 
256     AffineTransform contentTransformation;
257     if (attributes.patternContentUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX)
258         contentTransformation = tileImageTransform;
259 
260     // Draw the content into the ImageBuffer.
261     for (Element* element = ElementTraversal::firstWithin(*attributes.patternContentElement()); element; element = ElementTraversal::nextSibling(*element)) {
262         if (!element->isSVGElement() || !element->renderer())
263             continue;
264         if (element->renderer()->needsLayout())
265             return nullptr;
266         SVGRenderingContext::renderSubtree(tileImage->context(), element->renderer(), contentTransformation);
267     }
268 
269     return tileImage.release();
270 }
271 
272 }
273