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 33namespace blink { 34 35CrossfadeGeneratedImage::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 44void 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 85void 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 98void 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