1 /* 2 * Copyright (c) 2008, Google 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 are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include "config.h" 32 33 #if !PLATFORM(ANDROID) 34 #include "skia/ext/image_operations.h" 35 #endif 36 37 #include "NativeImageSkia.h" 38 #include "SharedGraphicsContext3D.h" 39 #include "SkiaUtils.h" 40 41 namespace WebCore { 42 43 NativeImageSkia::NativeImageSkia() 44 : m_isDataComplete(false), 45 m_lastRequestSize(0, 0), 46 m_resizeRequests(0) 47 { 48 } 49 50 NativeImageSkia::NativeImageSkia(const SkBitmap& other) 51 : SkBitmap(other), 52 m_isDataComplete(false), 53 m_lastRequestSize(0, 0), 54 m_resizeRequests(0) 55 { 56 } 57 58 59 NativeImageSkia::~NativeImageSkia() 60 { 61 #if PLATFORM(ANDROID) 62 // SharedGraphicsContext3D::removeTexturesFor() takes a NativeImagePtr. On 63 // Chromium, this is NativeImageSkia, which inherits from SkBitmap. On 64 // Android, NativeImagePtr is a SkBitmapRef, which is a wrapper around 65 // SkBitmap. Failing to call removeTexturesFor() probably causes a leak. 66 // TODO: Fix this. See http://b/3047425 67 #else 68 SharedGraphicsContext3D::removeTexturesFor(this); 69 #endif 70 } 71 72 int NativeImageSkia::decodedSize() const 73 { 74 return getSize() + m_resizedImage.getSize(); 75 } 76 77 bool NativeImageSkia::hasResizedBitmap(int w, int h) const 78 { 79 if (m_lastRequestSize.width() == w && m_lastRequestSize.height() == h) 80 m_resizeRequests++; 81 else { 82 m_lastRequestSize = IntSize(w, h); 83 m_resizeRequests = 0; 84 } 85 86 return m_resizedImage.width() == w && m_resizedImage.height() == h; 87 } 88 89 // FIXME: don't cache when image is in-progress. 90 91 SkBitmap NativeImageSkia::resizedBitmap(int w, int h) const 92 { 93 #if !PLATFORM(ANDROID) 94 if (m_resizedImage.width() != w || m_resizedImage.height() != h) 95 m_resizedImage = skia::ImageOperations::Resize(*this, skia::ImageOperations::RESIZE_LANCZOS3, w, h); 96 #endif 97 98 return m_resizedImage; 99 } 100 101 bool NativeImageSkia::shouldCacheResampling(int destWidth, 102 int destHeight, 103 int destSubsetWidth, 104 int destSubsetHeight) const 105 { 106 // We can not cache incomplete frames. This might be a good optimization in 107 // the future, were we know how much of the frame has been decoded, so when 108 // we incrementally draw more of the image, we only have to resample the 109 // parts that are changed. 110 if (!m_isDataComplete) 111 return false; 112 113 // If the destination bitmap is small, we'll always allow caching, since 114 // there is not very much penalty for computing it and it may come in handy. 115 static const int kSmallBitmapSize = 4096; 116 if (destWidth * destHeight <= kSmallBitmapSize) 117 return true; 118 119 // If "too many" requests have been made for this bitmap, we assume that 120 // many more will be made as well, and we'll go ahead and cache it. 121 static const int kManyRequestThreshold = 4; 122 if (m_lastRequestSize.width() == destWidth && 123 m_lastRequestSize.height() == destHeight) { 124 if (m_resizeRequests >= kManyRequestThreshold) 125 return true; 126 } else { 127 // When a different size is being requested, count this as a query 128 // (hasResizedBitmap) and reset the counter. 129 m_lastRequestSize = IntSize(destWidth, destHeight); 130 m_resizeRequests = 0; 131 } 132 133 // Otherwise, use the heuristic that if more than 1/4 of the image is 134 // requested, it's worth caching. 135 int destSize = destWidth * destHeight; 136 int destSubsetSize = destSubsetWidth * destSubsetHeight; 137 return destSize / 4 < destSubsetSize; 138 } 139 140 } // namespace WebCore 141