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 using namespace std; 34 35 namespace WebCore { 36 37 CrossfadeGeneratedImage::CrossfadeGeneratedImage(Image* fromImage, Image* toImage, float percentage, IntSize crossfadeSize, const IntSize& size) 38 : m_fromImage(fromImage) 39 , m_toImage(toImage) 40 , m_percentage(percentage) 41 , m_crossfadeSize(crossfadeSize) 42 { 43 m_size = size; 44 } 45 46 void CrossfadeGeneratedImage::drawCrossfade(GraphicsContext* context) 47 { 48 float inversePercentage = 1 - m_percentage; 49 50 IntSize fromImageSize = m_fromImage->size(); 51 IntSize toImageSize = m_toImage->size(); 52 53 // Draw nothing if either of the images hasn't loaded yet. 54 if (m_fromImage == Image::nullImage() || m_toImage == Image::nullImage()) 55 return; 56 57 GraphicsContextStateSaver stateSaver(*context); 58 59 context->clip(IntRect(IntPoint(), m_crossfadeSize)); 60 context->beginTransparencyLayer(1); 61 62 // Draw the image we're fading away from. 63 context->save(); 64 if (m_crossfadeSize != fromImageSize) { 65 context->scale( 66 static_cast<float>(m_crossfadeSize.width()) / fromImageSize.width(), 67 static_cast<float>(m_crossfadeSize.height()) / fromImageSize.height()); 68 } 69 context->setAlphaAsFloat(inversePercentage); 70 context->drawImage(m_fromImage, IntPoint()); 71 context->restore(); 72 73 // Draw the image we're fading towards. 74 context->save(); 75 if (m_crossfadeSize != toImageSize) { 76 context->scale( 77 static_cast<float>(m_crossfadeSize.width()) / toImageSize.width(), 78 static_cast<float>(m_crossfadeSize.height()) / toImageSize.height()); 79 } 80 context->setAlphaAsFloat(m_percentage); 81 context->drawImage(m_toImage, IntPoint(), CompositePlusLighter); 82 context->restore(); 83 84 context->endLayer(); 85 } 86 87 void CrossfadeGeneratedImage::draw(GraphicsContext* context, const FloatRect& dstRect, const FloatRect& srcRect, CompositeOperator compositeOp, blink::WebBlendMode blendMode) 88 { 89 GraphicsContextStateSaver stateSaver(*context); 90 context->setCompositeOperation(compositeOp, blendMode); 91 context->clip(dstRect); 92 context->translate(dstRect.x(), dstRect.y()); 93 if (dstRect.size() != srcRect.size()) 94 context->scale(dstRect.width() / srcRect.width(), dstRect.height() / srcRect.height()); 95 context->translate(-srcRect.x(), -srcRect.y()); 96 97 drawCrossfade(context); 98 } 99 100 void CrossfadeGeneratedImage::drawPattern(GraphicsContext* context, const FloatRect& srcRect, const FloatSize& scale, const FloatPoint& phase, CompositeOperator compositeOp, const FloatRect& dstRect, blink::WebBlendMode blendMode, const IntSize& repeatSpacing) 101 { 102 OwnPtr<ImageBuffer> imageBuffer = context->createCompatibleBuffer(m_size); 103 if (!imageBuffer) 104 return; 105 106 // Fill with the cross-faded image. 107 GraphicsContext* graphicsContext = imageBuffer->context(); 108 drawCrossfade(graphicsContext); 109 110 // Tile the image buffer into the context. 111 imageBuffer->drawPattern(context, srcRect, scale, phase, compositeOp, dstRect, blendMode, repeatSpacing); 112 } 113 114 } 115