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
NativeImageSkia()43 NativeImageSkia::NativeImageSkia()
44 : m_isDataComplete(false),
45 m_lastRequestSize(0, 0),
46 m_resizeRequests(0)
47 {
48 }
49
NativeImageSkia(const SkBitmap & other)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
~NativeImageSkia()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
decodedSize() const72 int NativeImageSkia::decodedSize() const
73 {
74 return getSize() + m_resizedImage.getSize();
75 }
76
hasResizedBitmap(int w,int h) const77 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
resizedBitmap(int w,int h) const91 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
shouldCacheResampling(int destWidth,int destHeight,int destSubsetWidth,int destSubsetHeight) const101 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