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/FrameHost.h"
30 #include "core/frame/FrameView.h"
31 #include "core/frame/LocalFrame.h"
32 #include "core/frame/Settings.h"
33 #include "core/paint/SVGImagePainter.h"
34 #include "core/rendering/RenderLayer.h"
35 #include "core/rendering/svg/RenderSVGImage.h"
36 #include "core/rendering/svg/RenderSVGResource.h"
37 #include "core/rendering/svg/RenderSVGResourceFilter.h"
38 #include "core/rendering/svg/RenderSVGResourceMasker.h"
39 #include "core/rendering/svg/SVGResources.h"
40 #include "core/rendering/svg/SVGResourcesCache.h"
41 #include "platform/FloatConversion.h"
42
43 static int kMaxImageBufferSize = 4096;
44
45 namespace blink {
46
isRenderingMaskImage(RenderObject * object)47 static inline bool isRenderingMaskImage(RenderObject* object)
48 {
49 if (object->frame() && object->frame()->view())
50 return object->frame()->view()->paintBehavior() & PaintBehaviorRenderingSVGMask;
51 return false;
52 }
53
~SVGRenderingContext()54 SVGRenderingContext::~SVGRenderingContext()
55 {
56 // Fast path if we don't need to restore anything.
57 if (!(m_renderingFlags & ActionsNeeded))
58 return;
59
60 ASSERT(m_object && m_paintInfo);
61
62 if (m_renderingFlags & PostApplyResources) {
63 ASSERT(m_masker || m_clipper || m_filter);
64 ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object));
65
66 if (m_filter) {
67 ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object)->filter() == m_filter);
68 m_filter->postApplyResource(m_object, m_paintInfo->context);
69 m_paintInfo->context = m_savedContext;
70 m_paintInfo->rect = m_savedPaintRect;
71 }
72
73 if (m_clipper) {
74 ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object)->clipper() == m_clipper);
75 m_clipper->postApplyStatefulResource(m_object, m_paintInfo->context, m_clipperState);
76 }
77
78 if (m_masker) {
79 ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object)->masker() == m_masker);
80 m_masker->postApplyResource(m_object, m_paintInfo->context);
81 }
82 }
83
84 if (m_renderingFlags & EndOpacityLayer)
85 m_paintInfo->context->endLayer();
86
87 if (m_renderingFlags & RestoreGraphicsContext)
88 m_paintInfo->context->restore();
89 }
90
prepareToRenderSVGContent(RenderObject * object,PaintInfo & paintInfo)91 void SVGRenderingContext::prepareToRenderSVGContent(RenderObject* object, PaintInfo& paintInfo)
92 {
93 ASSERT(object);
94
95 #if ENABLE(ASSERT)
96 // This function must not be called twice!
97 ASSERT(!(m_renderingFlags & PrepareToRenderSVGContentWasCalled));
98 m_renderingFlags |= PrepareToRenderSVGContentWasCalled;
99 #endif
100
101 m_object = object;
102 m_paintInfo = &paintInfo;
103 m_filter = 0;
104
105 RenderStyle* style = m_object->style();
106 ASSERT(style);
107
108 const SVGRenderStyle& svgStyle = style->svgStyle();
109
110 // Setup transparency layers before setting up SVG resources!
111 bool isRenderingMask = isRenderingMaskImage(m_object);
112 // RenderLayer takes care of root opacity.
113 float opacity = (object->isSVGRoot() || isRenderingMask) ? 1 : style->opacity();
114 bool hasBlendMode = style->hasBlendMode() && !isRenderingMask;
115
116 if (opacity < 1 || hasBlendMode || style->hasIsolation()) {
117 FloatRect paintInvalidationRect = m_object->paintInvalidationRectInLocalCoordinates();
118 m_paintInfo->context->clip(paintInvalidationRect);
119
120 if (hasBlendMode) {
121 if (!(m_renderingFlags & RestoreGraphicsContext)) {
122 m_paintInfo->context->save();
123 m_renderingFlags |= RestoreGraphicsContext;
124 }
125 m_paintInfo->context->setCompositeOperation(CompositeSourceOver, style->blendMode());
126 }
127
128 m_paintInfo->context->beginTransparencyLayer(opacity);
129
130 if (hasBlendMode)
131 m_paintInfo->context->setCompositeOperation(CompositeSourceOver, WebBlendModeNormal);
132
133 m_renderingFlags |= EndOpacityLayer;
134 }
135
136 ClipPathOperation* clipPathOperation = style->clipPath();
137 if (clipPathOperation && clipPathOperation->type() == ClipPathOperation::SHAPE) {
138 ShapeClipPathOperation* clipPath = toShapeClipPathOperation(clipPathOperation);
139 m_paintInfo->context->clipPath(clipPath->path(object->objectBoundingBox()), clipPath->windRule());
140 }
141
142 SVGResources* resources = SVGResourcesCache::cachedResourcesForRenderObject(m_object);
143 if (!resources) {
144 if (svgStyle.hasFilter())
145 return;
146
147 m_renderingFlags |= RenderingPrepared;
148 return;
149 }
150
151 if (!isRenderingMask) {
152 if (RenderSVGResourceMasker* masker = resources->masker()) {
153 if (!masker->applyResource(m_object, style, m_paintInfo->context, ApplyToDefaultMode))
154 return;
155 m_masker = masker;
156 m_renderingFlags |= PostApplyResources;
157 }
158 }
159
160 RenderSVGResourceClipper* clipper = resources->clipper();
161 if (!clipPathOperation && clipper) {
162 if (!clipper->applyStatefulResource(m_object, m_paintInfo->context, m_clipperState))
163 return;
164 m_clipper = clipper;
165 m_renderingFlags |= PostApplyResources;
166 }
167
168 if (!isRenderingMask) {
169 m_filter = resources->filter();
170 if (m_filter) {
171 m_savedContext = m_paintInfo->context;
172 m_savedPaintRect = m_paintInfo->rect;
173 // Return with false here may mean that we don't need to draw the content
174 // (because it was either drawn before or empty) but we still need to apply the filter.
175 m_renderingFlags |= PostApplyResources;
176 if (!m_filter->applyResource(m_object, style, m_paintInfo->context, ApplyToDefaultMode))
177 return;
178
179 // Since we're caching the resulting bitmap and do not invalidate it on paint invalidation rect
180 // changes, we need to paint the whole filter region. Otherwise, elements not visible
181 // at the time of the initial paint (due to scrolling, window size, etc.) will never
182 // be drawn.
183 m_paintInfo->rect = IntRect(m_filter->drawingRegion(m_object));
184 }
185 }
186
187 m_renderingFlags |= RenderingPrepared;
188 }
189
currentContentTransformation()190 static AffineTransform& currentContentTransformation()
191 {
192 DEFINE_STATIC_LOCAL(AffineTransform, s_currentContentTransformation, ());
193 return s_currentContentTransformation;
194 }
195
calculateScreenFontSizeScalingFactor(const RenderObject * renderer)196 float SVGRenderingContext::calculateScreenFontSizeScalingFactor(const RenderObject* renderer)
197 {
198 ASSERT(renderer);
199
200 AffineTransform ctm;
201 // FIXME: calculateDeviceSpaceTransformation() queries layer compositing state - which is not
202 // supported during layout. Hence, the result may not include all CSS transforms.
203 calculateDeviceSpaceTransformation(renderer, ctm);
204 return narrowPrecisionToFloat(sqrt((pow(ctm.xScale(), 2) + pow(ctm.yScale(), 2)) / 2));
205 }
206
calculateDeviceSpaceTransformation(const RenderObject * renderer,AffineTransform & absoluteTransform)207 void SVGRenderingContext::calculateDeviceSpaceTransformation(const RenderObject* renderer, AffineTransform& absoluteTransform)
208 {
209 // FIXME: trying to compute a device space transform at record time is wrong. All clients
210 // should be updated to avoid relying on this information, and the method should be removed.
211
212 ASSERT(renderer);
213 // We're about to possibly clear renderer, so save the deviceScaleFactor now.
214 float deviceScaleFactor = renderer->document().frameHost()->deviceScaleFactor();
215
216 // Walk up the render tree, accumulating SVG transforms.
217 absoluteTransform = currentContentTransformation();
218 while (renderer) {
219 absoluteTransform = renderer->localToParentTransform() * absoluteTransform;
220 if (renderer->isSVGRoot())
221 break;
222 renderer = renderer->parent();
223 }
224
225 // Continue walking up the layer tree, accumulating CSS transforms.
226 RenderLayer* layer = renderer ? renderer->enclosingLayer() : 0;
227 while (layer && layer->isAllowedToQueryCompositingState()) {
228 // We can stop at compositing layers, to match the backing resolution.
229 // FIXME: should we be computing the transform to the nearest composited layer,
230 // or the nearest composited layer that does not paint into its ancestor?
231 // I think this is the nearest composited ancestor since we will inherit its
232 // transforms in the composited layer tree.
233 if (layer->compositingState() != NotComposited)
234 break;
235
236 if (TransformationMatrix* layerTransform = layer->transform())
237 absoluteTransform = layerTransform->toAffineTransform() * absoluteTransform;
238
239 layer = layer->parent();
240 }
241
242 absoluteTransform.scale(deviceScaleFactor);
243 }
244
renderSubtree(GraphicsContext * context,RenderObject * item,const AffineTransform & subtreeContentTransformation)245 void SVGRenderingContext::renderSubtree(GraphicsContext* context, RenderObject* item, const AffineTransform& subtreeContentTransformation)
246 {
247 ASSERT(item);
248 ASSERT(context);
249
250 PaintInfo info(context, PaintInfo::infiniteRect(), PaintPhaseForeground, PaintBehaviorNormal);
251
252 AffineTransform& contentTransformation = currentContentTransformation();
253 AffineTransform savedContentTransformation = contentTransformation;
254 contentTransformation = subtreeContentTransformation * contentTransformation;
255
256 ASSERT(!item->needsLayout());
257 item->paint(info, IntPoint());
258
259 contentTransformation = savedContentTransformation;
260 }
261
clampedAbsoluteTargetRect(const FloatRect & absoluteTargetRect)262 FloatRect SVGRenderingContext::clampedAbsoluteTargetRect(const FloatRect& absoluteTargetRect)
263 {
264 const FloatSize maxImageBufferSize(kMaxImageBufferSize, kMaxImageBufferSize);
265 return FloatRect(absoluteTargetRect.location(), absoluteTargetRect.size().shrunkTo(maxImageBufferSize));
266 }
267
clear2DRotation(AffineTransform & transform)268 void SVGRenderingContext::clear2DRotation(AffineTransform& transform)
269 {
270 AffineTransform::DecomposedType decomposition;
271 transform.decompose(decomposition);
272 decomposition.angle = 0;
273 transform.recompose(decomposition);
274 }
275
bufferForeground(OwnPtr<ImageBuffer> & imageBuffer)276 bool SVGRenderingContext::bufferForeground(OwnPtr<ImageBuffer>& imageBuffer)
277 {
278 ASSERT(m_paintInfo);
279 ASSERT(m_object->isSVGImage());
280 FloatRect boundingBox = m_object->objectBoundingBox();
281
282 // Invalidate an existing buffer if the scale is not correct.
283 if (imageBuffer) {
284 AffineTransform transform = m_paintInfo->context->getCTM();
285 IntSize expandedBoundingBox = expandedIntSize(boundingBox.size());
286 IntSize bufferSize(static_cast<int>(ceil(expandedBoundingBox.width() * transform.xScale())), static_cast<int>(ceil(expandedBoundingBox.height() * transform.yScale())));
287 if (bufferSize != imageBuffer->size())
288 imageBuffer.clear();
289 }
290
291 // Create a new buffer and paint the foreground into it.
292 if (!imageBuffer) {
293 if ((imageBuffer = m_paintInfo->context->createRasterBuffer(expandedIntSize(boundingBox.size())))) {
294 GraphicsContext* bufferedRenderingContext = imageBuffer->context();
295 bufferedRenderingContext->translate(-boundingBox.x(), -boundingBox.y());
296 PaintInfo bufferedInfo(*m_paintInfo);
297 bufferedInfo.context = bufferedRenderingContext;
298 SVGImagePainter::paintForeground(toRenderSVGImage(*m_object), bufferedInfo);
299 } else
300 return false;
301 }
302
303 m_paintInfo->context->drawImageBuffer(imageBuffer.get(), boundingBox);
304 return true;
305 }
306
307 } // namespace blink
308