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 *
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Library General Public
11 * License as published by the Free Software Foundation; either
12 * version 2 of the License, or (at your option) any later version.
13 *
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Library General Public License for more details.
18 *
19 * You should have received a copy of the GNU Library General Public License
20 * along with this library; see the file COPYING.LIB. If not, write to
21 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
22 * Boston, MA 02110-1301, USA.
23 */
24
25 #include "config.h"
26
27 #include "core/rendering/svg/SVGRenderingContext.h"
28
29 #include "core/frame/Frame.h"
30 #include "core/frame/FrameView.h"
31 #include "core/page/Page.h"
32 #include "core/rendering/RenderLayer.h"
33 #include "core/rendering/svg/RenderSVGImage.h"
34 #include "core/rendering/svg/RenderSVGResource.h"
35 #include "core/rendering/svg/RenderSVGResourceFilter.h"
36 #include "core/rendering/svg/RenderSVGResourceMasker.h"
37 #include "core/rendering/svg/SVGResources.h"
38 #include "core/rendering/svg/SVGResourcesCache.h"
39
40 static int kMaxImageBufferSize = 4096;
41
42 namespace WebCore {
43
isRenderingMaskImage(RenderObject * object)44 static inline bool isRenderingMaskImage(RenderObject* object)
45 {
46 if (object->frame() && object->frame()->view())
47 return object->frame()->view()->paintBehavior() & PaintBehaviorRenderingSVGMask;
48 return false;
49 }
50
~SVGRenderingContext()51 SVGRenderingContext::~SVGRenderingContext()
52 {
53 // Fast path if we don't need to restore anything.
54 if (!(m_renderingFlags & ActionsNeeded))
55 return;
56
57 ASSERT(m_object && m_paintInfo);
58
59 if (m_renderingFlags & PostApplyResources) {
60 ASSERT(m_masker || m_clipper || m_filter);
61 ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object));
62
63 if (m_filter) {
64 ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object)->filter() == m_filter);
65 m_filter->postApplyResource(m_object, m_paintInfo->context, ApplyToDefaultMode, 0, 0);
66 m_paintInfo->context = m_savedContext;
67 m_paintInfo->rect = m_savedPaintRect;
68 }
69
70 if (m_clipper) {
71 ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object)->clipper() == m_clipper);
72 m_clipper->postApplyStatefulResource(m_object, m_paintInfo->context, m_clipperContext);
73 }
74
75 if (m_masker) {
76 ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object)->masker() == m_masker);
77 m_masker->postApplyResource(m_object, m_paintInfo->context, ApplyToDefaultMode, 0, 0);
78 }
79 }
80
81 if (m_renderingFlags & EndOpacityLayer)
82 m_paintInfo->context->endLayer();
83
84 if (m_renderingFlags & RestoreGraphicsContext)
85 m_paintInfo->context->restore();
86 }
87
prepareToRenderSVGContent(RenderObject * object,PaintInfo & paintInfo,NeedsGraphicsContextSave needsGraphicsContextSave)88 void SVGRenderingContext::prepareToRenderSVGContent(RenderObject* object, PaintInfo& paintInfo, NeedsGraphicsContextSave needsGraphicsContextSave)
89 {
90 ASSERT(object);
91
92 #ifndef NDEBUG
93 // This function must not be called twice!
94 ASSERT(!(m_renderingFlags & PrepareToRenderSVGContentWasCalled));
95 m_renderingFlags |= PrepareToRenderSVGContentWasCalled;
96 #endif
97
98 m_object = object;
99 m_paintInfo = &paintInfo;
100 m_filter = 0;
101
102 // We need to save / restore the context even if the initialization failed.
103 if (needsGraphicsContextSave == SaveGraphicsContext) {
104 m_paintInfo->context->save();
105 m_renderingFlags |= RestoreGraphicsContext;
106 }
107
108 RenderStyle* style = m_object->style();
109 ASSERT(style);
110
111 const SVGRenderStyle* svgStyle = style->svgStyle();
112 ASSERT(svgStyle);
113
114 // Setup transparency layers before setting up SVG resources!
115 bool isRenderingMask = isRenderingMaskImage(m_object);
116 float opacity = isRenderingMask ? 1 : style->opacity();
117 blink::WebBlendMode blendMode = isRenderingMask ? blink::WebBlendModeNormal : style->blendMode();
118 if (opacity < 1 || blendMode != blink::WebBlendModeNormal) {
119 FloatRect repaintRect = m_object->repaintRectInLocalCoordinates();
120
121 if (opacity < 1 || blendMode != blink::WebBlendModeNormal) {
122 m_paintInfo->context->clip(repaintRect);
123 if (blendMode != blink::WebBlendModeNormal) {
124 if (!(m_renderingFlags & RestoreGraphicsContext)) {
125 m_paintInfo->context->save();
126 m_renderingFlags |= RestoreGraphicsContext;
127 }
128 m_paintInfo->context->setCompositeOperation(CompositeSourceOver, blendMode);
129 }
130 m_paintInfo->context->beginTransparencyLayer(opacity);
131 m_renderingFlags |= EndOpacityLayer;
132 }
133 }
134
135 ClipPathOperation* clipPathOperation = style->clipPath();
136 if (clipPathOperation && clipPathOperation->type() == ClipPathOperation::SHAPE) {
137 ShapeClipPathOperation* clipPath = toShapeClipPathOperation(clipPathOperation);
138 m_paintInfo->context->clipPath(clipPath->path(object->objectBoundingBox()), clipPath->windRule());
139 }
140
141 SVGResources* resources = SVGResourcesCache::cachedResourcesForRenderObject(m_object);
142 if (!resources) {
143 if (svgStyle->hasFilter())
144 return;
145
146 m_renderingFlags |= RenderingPrepared;
147 return;
148 }
149
150 if (!isRenderingMask) {
151 if (RenderSVGResourceMasker* masker = resources->masker()) {
152 if (!masker->applyResource(m_object, style, m_paintInfo->context, ApplyToDefaultMode))
153 return;
154 m_masker = masker;
155 m_renderingFlags |= PostApplyResources;
156 }
157 }
158
159 RenderSVGResourceClipper* clipper = resources->clipper();
160 if (!clipPathOperation && clipper) {
161 if (!clipper->applyStatefulResource(m_object, m_paintInfo->context, m_clipperContext))
162 return;
163 m_clipper = clipper;
164 m_renderingFlags |= PostApplyResources;
165 }
166
167 if (!isRenderingMask) {
168 m_filter = resources->filter();
169 if (m_filter) {
170 m_savedContext = m_paintInfo->context;
171 m_savedPaintRect = m_paintInfo->rect;
172 // Return with false here may mean that we don't need to draw the content
173 // (because it was either drawn before or empty) but we still need to apply the filter.
174 m_renderingFlags |= PostApplyResources;
175 if (!m_filter->applyResource(m_object, style, m_paintInfo->context, ApplyToDefaultMode))
176 return;
177
178 // Since we're caching the resulting bitmap and do not invalidate it on repaint rect
179 // changes, we need to paint the whole filter region. Otherwise, elements not visible
180 // at the time of the initial paint (due to scrolling, window size, etc.) will never
181 // be drawn.
182 m_paintInfo->rect = IntRect(m_filter->drawingRegion(m_object));
183 }
184 }
185
186 m_renderingFlags |= RenderingPrepared;
187 }
188
currentContentTransformation()189 static AffineTransform& currentContentTransformation()
190 {
191 DEFINE_STATIC_LOCAL(AffineTransform, s_currentContentTransformation, ());
192 return s_currentContentTransformation;
193 }
194
calculateScreenFontSizeScalingFactor(const RenderObject * renderer)195 float SVGRenderingContext::calculateScreenFontSizeScalingFactor(const RenderObject* renderer)
196 {
197 ASSERT(renderer);
198
199 AffineTransform ctm;
200 calculateTransformationToOutermostCoordinateSystem(renderer, ctm);
201 return narrowPrecisionToFloat(sqrt((pow(ctm.xScale(), 2) + pow(ctm.yScale(), 2)) / 2));
202 }
203
calculateTransformationToOutermostCoordinateSystem(const RenderObject * renderer,AffineTransform & absoluteTransform)204 void SVGRenderingContext::calculateTransformationToOutermostCoordinateSystem(const RenderObject* renderer, AffineTransform& absoluteTransform)
205 {
206 ASSERT(renderer);
207 absoluteTransform = currentContentTransformation();
208
209 float deviceScaleFactor = 1;
210 if (Page* page = renderer->document().page())
211 deviceScaleFactor = page->deviceScaleFactor();
212
213 // Walk up the render tree, accumulating SVG transforms.
214 while (renderer) {
215 absoluteTransform = renderer->localToParentTransform() * absoluteTransform;
216 if (renderer->isSVGRoot())
217 break;
218 renderer = renderer->parent();
219 }
220
221 // Continue walking up the layer tree, accumulating CSS transforms.
222 RenderLayer* layer = renderer ? renderer->enclosingLayer() : 0;
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 // FIXME: should we be computing the transform to the nearest composited layer,
229 // or the nearest composited layer that does not paint into its ancestor?
230 // I think this is the nearest composited ancestor since we will inherit its
231 // transforms in the composited layer tree.
232 if (layer->hasCompositedLayerMapping())
233 break;
234
235 layer = layer->parent();
236 }
237
238 if (deviceScaleFactor != 1)
239 absoluteTransform.scale(deviceScaleFactor);
240 }
241
renderSubtree(GraphicsContext * context,RenderObject * item,const AffineTransform & subtreeContentTransformation)242 void SVGRenderingContext::renderSubtree(GraphicsContext* context, RenderObject* item, const AffineTransform& subtreeContentTransformation)
243 {
244 ASSERT(item);
245 ASSERT(context);
246
247 PaintInfo info(context, PaintInfo::infiniteRect(), PaintPhaseForeground, PaintBehaviorNormal);
248
249 AffineTransform& contentTransformation = currentContentTransformation();
250 AffineTransform savedContentTransformation = contentTransformation;
251 contentTransformation = subtreeContentTransformation * contentTransformation;
252
253 ASSERT(!item->needsLayout());
254 item->paint(info, IntPoint());
255
256 contentTransformation = savedContentTransformation;
257 }
258
clampedAbsoluteTargetRect(const FloatRect & absoluteTargetRect)259 FloatRect SVGRenderingContext::clampedAbsoluteTargetRect(const FloatRect& absoluteTargetRect)
260 {
261 const FloatSize maxImageBufferSize(kMaxImageBufferSize, kMaxImageBufferSize);
262 return FloatRect(absoluteTargetRect.location(), absoluteTargetRect.size().shrunkTo(maxImageBufferSize));
263 }
264
clear2DRotation(AffineTransform & transform)265 void SVGRenderingContext::clear2DRotation(AffineTransform& transform)
266 {
267 AffineTransform::DecomposedType decomposition;
268 transform.decompose(decomposition);
269 decomposition.angle = 0;
270 transform.recompose(decomposition);
271 }
272
bufferForeground(OwnPtr<ImageBuffer> & imageBuffer)273 bool SVGRenderingContext::bufferForeground(OwnPtr<ImageBuffer>& imageBuffer)
274 {
275 ASSERT(m_paintInfo);
276 ASSERT(m_object->isSVGImage());
277 FloatRect boundingBox = m_object->objectBoundingBox();
278
279 // Invalidate an existing buffer if the scale is not correct.
280 if (imageBuffer) {
281 AffineTransform transform = m_paintInfo->context->getCTM(GraphicsContext::DefinitelyIncludeDeviceScale);
282 IntSize expandedBoundingBox = expandedIntSize(boundingBox.size());
283 IntSize bufferSize(static_cast<int>(ceil(expandedBoundingBox.width() * transform.xScale())), static_cast<int>(ceil(expandedBoundingBox.height() * transform.yScale())));
284 if (bufferSize != imageBuffer->size())
285 imageBuffer.clear();
286 }
287
288 // Create a new buffer and paint the foreground into it.
289 if (!imageBuffer) {
290 if ((imageBuffer = m_paintInfo->context->createCompatibleBuffer(expandedIntSize(boundingBox.size())))) {
291 GraphicsContext* bufferedRenderingContext = imageBuffer->context();
292 bufferedRenderingContext->translate(-boundingBox.x(), -boundingBox.y());
293 PaintInfo bufferedInfo(*m_paintInfo);
294 bufferedInfo.context = bufferedRenderingContext;
295 toRenderSVGImage(m_object)->paintForeground(bufferedInfo);
296 } else
297 return false;
298 }
299
300 m_paintInfo->context->drawImageBuffer(imageBuffer.get(), boundingBox);
301 return true;
302 }
303
304 }
305