• Home
  • History
  • Annotate
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2011 Apple Inc. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include "config.h"
27 #include "platform/graphics/CrossfadeGeneratedImage.h"
28 
29 #include "platform/geometry/FloatRect.h"
30 #include "platform/graphics/GraphicsContextStateSaver.h"
31 #include "platform/graphics/ImageBuffer.h"
32 
33 namespace blink {
34 
CrossfadeGeneratedImage(Image * fromImage,Image * toImage,float percentage,IntSize crossfadeSize,const IntSize & size)35 CrossfadeGeneratedImage::CrossfadeGeneratedImage(Image* fromImage, Image* toImage, float percentage, IntSize crossfadeSize, const IntSize& size)
36     : m_fromImage(fromImage)
37     , m_toImage(toImage)
38     , m_percentage(percentage)
39     , m_crossfadeSize(crossfadeSize)
40 {
41     m_size = size;
42 }
43 
drawCrossfade(GraphicsContext * context)44 void CrossfadeGeneratedImage::drawCrossfade(GraphicsContext* context)
45 {
46     float inversePercentage = 1 - m_percentage;
47 
48     IntSize fromImageSize = m_fromImage->size();
49     IntSize toImageSize = m_toImage->size();
50 
51     // Draw nothing if either of the images hasn't loaded yet.
52     if (m_fromImage == Image::nullImage() || m_toImage == Image::nullImage())
53         return;
54 
55     GraphicsContextStateSaver stateSaver(*context);
56 
57     context->clip(IntRect(IntPoint(), m_crossfadeSize));
58     context->beginTransparencyLayer(1);
59 
60     // Draw the image we're fading away from.
61     context->save();
62     if (m_crossfadeSize != fromImageSize) {
63         context->scale(
64             static_cast<float>(m_crossfadeSize.width()) / fromImageSize.width(),
65             static_cast<float>(m_crossfadeSize.height()) / fromImageSize.height());
66     }
67     context->setAlphaAsFloat(inversePercentage);
68     context->drawImage(m_fromImage, IntPoint());
69     context->restore();
70 
71     // Draw the image we're fading towards.
72     context->save();
73     if (m_crossfadeSize != toImageSize) {
74         context->scale(
75             static_cast<float>(m_crossfadeSize.width()) / toImageSize.width(),
76             static_cast<float>(m_crossfadeSize.height()) / toImageSize.height());
77     }
78     context->setAlphaAsFloat(m_percentage);
79     context->drawImage(m_toImage, IntPoint(), CompositePlusLighter);
80     context->restore();
81 
82     context->endLayer();
83 }
84 
draw(GraphicsContext * context,const FloatRect & dstRect,const FloatRect & srcRect,CompositeOperator compositeOp,WebBlendMode blendMode)85 void CrossfadeGeneratedImage::draw(GraphicsContext* context, const FloatRect& dstRect, const FloatRect& srcRect, CompositeOperator compositeOp, WebBlendMode blendMode)
86 {
87     GraphicsContextStateSaver stateSaver(*context);
88     context->setCompositeOperation(compositeOp, blendMode);
89     context->clip(dstRect);
90     context->translate(dstRect.x(), dstRect.y());
91     if (dstRect.size() != srcRect.size())
92         context->scale(dstRect.width() / srcRect.width(), dstRect.height() / srcRect.height());
93     context->translate(-srcRect.x(), -srcRect.y());
94 
95     drawCrossfade(context);
96 }
97 
drawPattern(GraphicsContext * context,const FloatRect & srcRect,const FloatSize & scale,const FloatPoint & phase,CompositeOperator compositeOp,const FloatRect & dstRect,WebBlendMode blendMode,const IntSize & repeatSpacing)98 void CrossfadeGeneratedImage::drawPattern(GraphicsContext* context, const FloatRect& srcRect, const FloatSize& scale, const FloatPoint& phase, CompositeOperator compositeOp, const FloatRect& dstRect, WebBlendMode blendMode, const IntSize& repeatSpacing)
99 {
100     OwnPtr<ImageBuffer> imageBuffer = context->createRasterBuffer(m_size);
101     if (!imageBuffer)
102         return;
103 
104     // Fill with the cross-faded image.
105     GraphicsContext* graphicsContext = imageBuffer->context();
106     drawCrossfade(graphicsContext);
107 
108     // Tile the image buffer into the context.
109     imageBuffer->drawPattern(context, srcRect, scale, phase, compositeOp, dstRect, blendMode, repeatSpacing);
110 }
111 
112 } // namespace blink
113