1 /*
2 * Copyright (C) Research In Motion Limited 2010. All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB. If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 */
19
20 #include "config.h"
21
22 #if ENABLE(SVG)
23 #include "SVGImageBufferTools.h"
24
25 #include "FrameView.h"
26 #include "GraphicsContext.h"
27 #include "RenderObject.h"
28 #include "RenderSVGContainer.h"
29 #include "RenderSVGRoot.h"
30
31 namespace WebCore {
32
currentContentTransformation()33 static AffineTransform& currentContentTransformation()
34 {
35 DEFINE_STATIC_LOCAL(AffineTransform, s_currentContentTransformation, ());
36 return s_currentContentTransformation;
37 }
38
calculateTransformationToOutermostSVGCoordinateSystem(const RenderObject * renderer,AffineTransform & absoluteTransform)39 void SVGImageBufferTools::calculateTransformationToOutermostSVGCoordinateSystem(const RenderObject* renderer, AffineTransform& absoluteTransform)
40 {
41 const RenderObject* current = renderer;
42 ASSERT(current);
43
44 absoluteTransform = currentContentTransformation();
45 while (current) {
46 absoluteTransform = current->localToParentTransform() * absoluteTransform;
47 if (current->isSVGRoot())
48 break;
49 current = current->parent();
50 }
51 }
52
createImageBuffer(const FloatRect & absoluteTargetRect,const FloatRect & clampedAbsoluteTargetRect,OwnPtr<ImageBuffer> & imageBuffer,ColorSpace colorSpace)53 bool SVGImageBufferTools::createImageBuffer(const FloatRect& absoluteTargetRect, const FloatRect& clampedAbsoluteTargetRect, OwnPtr<ImageBuffer>& imageBuffer, ColorSpace colorSpace)
54 {
55 IntSize imageSize(roundedImageBufferSize(clampedAbsoluteTargetRect.size()));
56 IntSize unclampedImageSize(SVGImageBufferTools::roundedImageBufferSize(absoluteTargetRect.size()));
57
58 // Don't create empty ImageBuffers.
59 if (imageSize.isEmpty())
60 return false;
61
62 OwnPtr<ImageBuffer> image = ImageBuffer::create(imageSize, colorSpace);
63 if (!image)
64 return false;
65
66 GraphicsContext* imageContext = image->context();
67 ASSERT(imageContext);
68
69 // Compensate rounding effects, as the absolute target rect is using floating-point numbers and the image buffer size is integer.
70 imageContext->scale(FloatSize(unclampedImageSize.width() / absoluteTargetRect.width(), unclampedImageSize.height() / absoluteTargetRect.height()));
71
72 imageBuffer = image.release();
73 return true;
74 }
75
renderSubtreeToImageBuffer(ImageBuffer * image,RenderObject * item,const AffineTransform & subtreeContentTransformation)76 void SVGImageBufferTools::renderSubtreeToImageBuffer(ImageBuffer* image, RenderObject* item, const AffineTransform& subtreeContentTransformation)
77 {
78 ASSERT(item);
79 ASSERT(image);
80 ASSERT(image->context());
81
82 PaintInfo info(image->context(), PaintInfo::infiniteRect(), PaintPhaseForeground, 0, 0, 0);
83
84 AffineTransform& contentTransformation = currentContentTransformation();
85 AffineTransform savedContentTransformation = contentTransformation;
86 contentTransformation = subtreeContentTransformation * contentTransformation;
87
88 item->layoutIfNeeded();
89 item->paint(info, 0, 0);
90
91 contentTransformation = savedContentTransformation;
92 }
93
clipToImageBuffer(GraphicsContext * context,const AffineTransform & absoluteTransform,const FloatRect & clampedAbsoluteTargetRect,OwnPtr<ImageBuffer> & imageBuffer)94 void SVGImageBufferTools::clipToImageBuffer(GraphicsContext* context, const AffineTransform& absoluteTransform, const FloatRect& clampedAbsoluteTargetRect, OwnPtr<ImageBuffer>& imageBuffer)
95 {
96 ASSERT(context);
97 ASSERT(imageBuffer);
98
99 // The mask image has been created in the absolute coordinate space, as the image should not be scaled.
100 // So the actual masking process has to be done in the absolute coordinate space as well.
101 context->concatCTM(absoluteTransform.inverse());
102 context->clipToImageBuffer(imageBuffer.get(), clampedAbsoluteTargetRect);
103 context->concatCTM(absoluteTransform);
104
105 // When nesting resources, with objectBoundingBox as content unit types, there's no use in caching the
106 // resulting image buffer as the parent resource already caches the result.
107 if (!currentContentTransformation().isIdentity())
108 imageBuffer.clear();
109 }
110
roundedImageBufferSize(const FloatSize & size)111 IntSize SVGImageBufferTools::roundedImageBufferSize(const FloatSize& size)
112 {
113 return IntSize(static_cast<int>(lroundf(size.width())), static_cast<int>(lroundf(size.height())));
114 }
115
clampedAbsoluteTargetRectForRenderer(const RenderObject * renderer,const FloatRect & absoluteTargetRect)116 FloatRect SVGImageBufferTools::clampedAbsoluteTargetRectForRenderer(const RenderObject* renderer, const FloatRect& absoluteTargetRect)
117 {
118 ASSERT(renderer);
119
120 const RenderSVGRoot* svgRoot = SVGRenderSupport::findTreeRootObject(renderer);
121 FloatRect clampedAbsoluteTargetRect = absoluteTargetRect;
122 clampedAbsoluteTargetRect.intersect(svgRoot->contentBoxRect());
123 return clampedAbsoluteTargetRect;
124 }
125
126 }
127
128 #endif // ENABLE(SVG)
129