src/third_party/WebKit/Source/core/rendering/svg/RenderSVGResourcePattern.cpp

   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/platform/graphics/GraphicsContext.h"
  26 #include "core/rendering/svg/SVGRenderSupport.h"
  27 #include "core/rendering/svg/SVGRenderingContext.h"
  28 #include "core/svg/PatternAttributes.h"
  29 #include "core/svg/SVGFitToViewBox.h"
  30
  31 namespace WebCore {
  32
  33 const RenderSVGResourceType RenderSVGResourcePattern::s_resourceType = PatternResourceType;
  34
  35 RenderSVGResourcePattern::RenderSVGResourcePattern(SVGPatternElement* node)
  36     : RenderSVGResourceContainer(node)
  37     , m_shouldCollectPatternAttributes(true)
  38 {
  39 }
  40
  41 void RenderSVGResourcePattern::removeAllClientsFromCache(bool markForInvalidation)
  42 {
  43     m_patternMap.clear();
  44     m_shouldCollectPatternAttributes = true;
  45     markAllClientsForInvalidation(markForInvalidation ? RepaintInvalidation : ParentOnlyInvalidation);
  46 }
  47
  48 void RenderSVGResourcePattern::removeClientFromCache(RenderObject* client, bool markForInvalidation)
  49 {
  50     ASSERT(client);
  51     m_patternMap.remove(client);
  52     markClientForInvalidation(client, markForInvalidation ? RepaintInvalidation : ParentOnlyInvalidation);
  53 }
  54
  55 PatternData* RenderSVGResourcePattern::buildPattern(RenderObject* object, unsigned short resourceMode)
  56 {
  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::calculateTransformationToOutermostCoordinateSystem(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     FloatRect clampedAbsoluteTileBoundaries;
  94
  95     // Scale the tile size to match the scale level of the patternTransform.
  96     absoluteTileBoundaries.scale(static_cast<float>(m_attributes.patternTransform().xScale()),
  97         static_cast<float>(m_attributes.patternTransform().yScale()));
  98
  99     // Build tile image.
 100     OwnPtr<ImageBuffer> tileImage = createTileImage(m_attributes, tileBoundaries, absoluteTileBoundaries, tileImageTransform, clampedAbsoluteTileBoundaries);
 101     if (!tileImage)
 102         return 0;
 103
 104     RefPtr<Image> copiedImage = tileImage->copyImage(CopyBackingStore);
 105     if (!copiedImage)
 106         return 0;
 107
 108     // Build pattern.
 109     OwnPtr<PatternData> patternData = adoptPtr(new PatternData);
 110     patternData->pattern = Pattern::create(copiedImage, true, true);
 111
 112     // Compute pattern space transformation.
 113     const IntSize tileImageSize = tileImage->logicalSize();
 114     patternData->transform.translate(tileBoundaries.x(), tileBoundaries.y());
 115     patternData->transform.scale(tileBoundaries.width() / tileImageSize.width(), tileBoundaries.height() / tileImageSize.height());
 116
 117     AffineTransform patternTransform = m_attributes.patternTransform();
 118     if (!patternTransform.isIdentity())
 119         patternData->transform = patternTransform * patternData->transform;
 120
 121     // Account for text drawing resetting the context to non-scaled, see SVGInlineTextBox::paintTextWithShadows.
 122     if (resourceMode & ApplyToTextMode) {
 123         AffineTransform additionalTextTransformation;
 124         if (shouldTransformOnTextPainting(object, additionalTextTransformation))
 125             patternData->transform *= additionalTextTransformation;
 126     }
 127     patternData->pattern->setPatternSpaceTransform(patternData->transform);
 128
 129     // Various calls above may trigger invalidations in some fringe cases (ImageBuffer allocation
 130     // failures in the SVG image cache for example). To avoid having our PatternData deleted by
 131     // removeAllClientsFromCache(), we only make it visible in the cache at the very end.
 132     return m_patternMap.set(object, patternData.release()).iterator->value.get();
 133 }
 134
 135 bool RenderSVGResourcePattern::applyResource(RenderObject* object, RenderStyle* style, GraphicsContext*& context, unsigned short resourceMode)
 136 {
 137     ASSERT(object);
 138     ASSERT(style);
 139     ASSERT(context);
 140     ASSERT(resourceMode != ApplyToDefaultMode);
 141
 142     // Spec: When the geometry of the applicable element has no width or height and objectBoundingBox is specified,
 143     // then the given effect (e.g. a gradient or a filter) will be ignored.
 144     FloatRect objectBoundingBox = object->objectBoundingBox();
 145     if (m_attributes.patternUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX && objectBoundingBox.isEmpty())
 146         return false;
 147
 148     PatternData* patternData = buildPattern(object, resourceMode);
 149     if (!patternData)
 150         return false;
 151
 152     // Draw pattern
 153     context->save();
 154
 155     const SVGRenderStyle* svgStyle = style->svgStyle();
 156     ASSERT(svgStyle);
 157
 158     if (resourceMode & ApplyToFillMode) {
 159         context->setAlpha(svgStyle->fillOpacity());
 160         context->setFillPattern(patternData->pattern);
 161         context->setFillRule(svgStyle->fillRule());
 162     } else if (resourceMode & ApplyToStrokeMode) {
 163         if (svgStyle->vectorEffect() == VE_NON_SCALING_STROKE)
 164             patternData->pattern->setPatternSpaceTransform(transformOnNonScalingStroke(object, patternData->transform));
 165         context->setAlpha(svgStyle->strokeOpacity());
 166         context->setStrokePattern(patternData->pattern);
 167         SVGRenderSupport::applyStrokeStyleToContext(context, style, object);
 168     }
 169
 170     if (resourceMode & ApplyToTextMode) {
 171         if (resourceMode & ApplyToFillMode)
 172             context->setTextDrawingMode(TextModeFill);
 173         else if (resourceMode & ApplyToStrokeMode)
 174             context->setTextDrawingMode(TextModeStroke);
 175     }
 176
 177     return true;
 178 }
 179
 180 void RenderSVGResourcePattern::postApplyResource(RenderObject*, GraphicsContext*& context, unsigned short resourceMode, const Path* path, const RenderSVGShape* shape)
 181 {
 182     ASSERT(context);
 183     ASSERT(resourceMode != ApplyToDefaultMode);
 184
 185     if (resourceMode & ApplyToFillMode) {
 186         if (path)
 187             context->fillPath(*path);
 188         else if (shape)
 189             shape->fillShape(context);
 190     }
 191     if (resourceMode & ApplyToStrokeMode) {
 192         if (path)
 193             context->strokePath(*path);
 194         else if (shape)
 195             shape->strokeShape(context);
 196     }
 197
 198     context->restore();
 199 }
 200
 201 static inline FloatRect calculatePatternBoundaries(const PatternAttributes& attributes,
 202                                                    const FloatRect& objectBoundingBox,
 203                                                    const SVGPatternElement* patternElement)
 204 {
 205     ASSERT(patternElement);
 206     return SVGLengthContext::resolveRectangle(patternElement, attributes.patternUnits(), objectBoundingBox, attributes.x(), attributes.y(), attributes.width(), attributes.height());
 207 }
 208
 209 bool RenderSVGResourcePattern::buildTileImageTransform(RenderObject* renderer,
 210                                                        const PatternAttributes& attributes,
 211                                                        const SVGPatternElement* patternElement,
 212                                                        FloatRect& patternBoundaries,
 213                                                        AffineTransform& tileImageTransform) const
 214 {
 215     ASSERT(renderer);
 216     ASSERT(patternElement);
 217
 218     FloatRect objectBoundingBox = renderer->objectBoundingBox();
 219     patternBoundaries = calculatePatternBoundaries(attributes, objectBoundingBox, patternElement);
 220     if (patternBoundaries.width() <= 0 || patternBoundaries.height() <= 0)
 221         return false;
 222
 223     AffineTransform viewBoxCTM = SVGFitToViewBox::viewBoxToViewTransform(attributes.viewBox(), attributes.preserveAspectRatio(), patternBoundaries.width(), patternBoundaries.height());
 224
 225     // Apply viewBox/objectBoundingBox transformations.
 226     if (!viewBoxCTM.isIdentity())
 227         tileImageTransform = viewBoxCTM;
 228     else if (attributes.patternContentUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX)
 229         tileImageTransform.scale(objectBoundingBox.width(), objectBoundingBox.height());
 230
 231     return true;
 232 }
 233
 234 PassOwnPtr<ImageBuffer> RenderSVGResourcePattern::createTileImage(const PatternAttributes& attributes,
 235                                                                   const FloatRect& tileBoundaries,
 236                                                                   const FloatRect& absoluteTileBoundaries,
 237                                                                   const AffineTransform& tileImageTransform,
 238                                                                   FloatRect& clampedAbsoluteTileBoundaries) const
 239 {
 240     clampedAbsoluteTileBoundaries = SVGRenderingContext::clampedAbsoluteTargetRect(absoluteTileBoundaries);
 241
 242     OwnPtr<ImageBuffer> tileImage;
 243
 244     if (!SVGRenderingContext::createImageBufferForPattern(absoluteTileBoundaries, clampedAbsoluteTileBoundaries, tileImage, Unaccelerated))
 245         return nullptr;
 246
 247     GraphicsContext* tileImageContext = tileImage->context();
 248     ASSERT(tileImageContext);
 249
 250     // The image buffer represents the final rendered size, so the content has to be scaled (to avoid pixelation).
 251     tileImageContext->scale(FloatSize(clampedAbsoluteTileBoundaries.width() / tileBoundaries.width(),
 252                                       clampedAbsoluteTileBoundaries.height() / tileBoundaries.height()));
 253
 254     // Apply tile image transformations.
 255     if (!tileImageTransform.isIdentity())
 256         tileImageContext->concatCTM(tileImageTransform);
 257
 258     AffineTransform contentTransformation;
 259     if (attributes.patternContentUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX)
 260         contentTransformation = tileImageTransform;
 261
 262     // Draw the content into the ImageBuffer.
 263     for (Node* node = attributes.patternContentElement()->firstChild(); node; node = node->nextSibling()) {
 264         if (!node->isSVGElement() || !node->renderer())
 265             continue;
 266         if (node->renderer()->needsLayout())
 267             return nullptr;
 268         SVGRenderingContext::renderSubtree(tileImage->context(), node->renderer(), contentTransformation);
 269     }
 270
 271     return tileImage.release();
 272 }
 273
 274 }