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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 #ifndef NativeImageSkia_h | |
32 #define NativeImageSkia_h | |
33 | |
34 #include "SkBitmap.h" | |
35 #include "SkRect.h" | |
36 #include "SkSize.h" | |
37 #include "SkXfermode.h" | |
38 #include "platform/geometry/IntSize.h" | |
39 #include "platform/graphics/GraphicsTypes.h" | |
40 #include "wtf/Forward.h" | |
41 #include "wtf/PassRefPtr.h" | |
42 #include "wtf/RefCounted.h" | |
43 | |
44 class SkMatrix; | |
45 class SkPaint; | |
46 | |
47 namespace WebCore { | |
48 | |
49 class FloatPoint; | |
50 class FloatRect; | |
51 class FloatSize; | |
52 class GraphicsContext; | |
53 | |
54 // Used by computeResamplingMode to tell how bitmaps should be resampled. | |
55 enum ResamplingMode { | |
56 // Nearest neighbor resampling. Used when we detect that the page is | |
57 // trying to make a pattern by stretching a small bitmap very large. | |
58 NoResampling, | |
59 | |
60 // Default skia resampling. Used for large growing of images where high | |
61 // quality resampling doesn't get us very much except a slowdown. | |
62 LinearResampling, | |
63 | |
64 // High quality resampling. | |
65 AwesomeResampling, | |
66 }; | |
67 | |
68 // This object is used as the "native image" in our port. When WebKit uses | |
69 // PassNativeImagePtr / NativeImagePtr, it is a smart pointer to this type. | |
70 // It has an SkBitmap, and also stores a cached resized image. | |
71 class NativeImageSkia : public RefCounted<NativeImageSkia> { | |
72 public: | |
73 static PassRefPtr<NativeImageSkia> create() | |
74 { | |
75 return adoptRef(new NativeImageSkia()); | |
76 } | |
77 | |
78 // This factory method does a shallow copy of the passed-in SkBitmap | |
79 // (ie., it references the same pixel data and bumps the refcount). Use | |
80 // only when you want sharing semantics. | |
81 static PassRefPtr<NativeImageSkia> create(const SkBitmap& bitmap, float reso
lutionScale = 1) | |
82 { | |
83 return adoptRef(new NativeImageSkia(bitmap, resolutionScale)); | |
84 } | |
85 | |
86 // This method does a shallow copy of the internal SkBitmap (ie., it | |
87 // references the same pixel data and bumps the refcount). Use only when | |
88 // you want sharing semantics. | |
89 PassRefPtr<NativeImageSkia> clone() const | |
90 { | |
91 return adoptRef(new NativeImageSkia(m_image, m_resolutionScale, m_resize
dImage, m_cachedImageInfo, m_resizeRequests)); | |
92 } | |
93 | |
94 ~NativeImageSkia(); | |
95 | |
96 // Returns the number of bytes of image data. This includes the cached | |
97 // resized version if there is one. | |
98 int decodedSize() const; | |
99 | |
100 // Sets the immutable flag on the bitmap, indicating that the image data | |
101 // will not be modified any further. This is called by the image decoder | |
102 // when all data is complete, used by us to know whether we can cache | |
103 // resized images, and used by Skia for various optimizations. | |
104 void setDataComplete() { m_image.setImmutable(); } | |
105 | |
106 // Returns true if the entire image has been decoded. | |
107 bool isDataComplete() const { return m_image.isImmutable(); } | |
108 | |
109 // Get reference to the internal SkBitmap representing this image. | |
110 const SkBitmap& bitmap() const { return m_image; } | |
111 SkBitmap& bitmap() { return m_image; } | |
112 | |
113 float resolutionScale() const { return m_resolutionScale; } | |
114 | |
115 // We can keep a resized version of the bitmap cached on this object. | |
116 // This function will return true if there is a cached version of the given | |
117 // scale and subset. | |
118 bool hasResizedBitmap(const SkISize& scaledImageSize, const SkIRect& scaledI
mageSubset) const; | |
119 | |
120 // This will return an existing resized image subset, or generate a new one | |
121 // of the specified size and subset and possibly cache it. | |
122 // | |
123 // scaledImageSize | |
124 // Dimensions of the scaled full image. | |
125 // | |
126 // scaledImageSubset | |
127 // Rectangle of the subset in the scaled image. | |
128 SkBitmap resizedBitmap(const SkISize& scaledImageSize, const SkIRect& scaled
ImageSubset) const; | |
129 | |
130 void draw(GraphicsContext*, const SkRect& srcRect, const SkRect& destRect, P
assRefPtr<SkXfermode>) const; | |
131 void drawPattern( | |
132 GraphicsContext*, | |
133 const FloatRect& srcRect, | |
134 const FloatSize& scale, | |
135 const FloatPoint& phase, | |
136 CompositeOperator, | |
137 const FloatRect& destRect, | |
138 blink::WebBlendMode, | |
139 const IntSize& repeatSpacing) const; | |
140 | |
141 private: | |
142 NativeImageSkia(); | |
143 | |
144 NativeImageSkia(const SkBitmap&, float resolutionScale); | |
145 | |
146 // ImageResourceInfo is used to uniquely identify cached or requested image | |
147 // resizes. | |
148 // Image resize is identified by the scaled image size and scaled image subs
et. | |
149 struct ImageResourceInfo { | |
150 SkISize scaledImageSize; | |
151 SkIRect scaledImageSubset; | |
152 | |
153 ImageResourceInfo(); | |
154 | |
155 bool isEqual(const SkISize& otherScaledImageSize, const SkIRect& otherSc
aledImageSubset) const; | |
156 void set(const SkISize& otherScaledImageSize, const SkIRect& otherScaled
ImageSubset); | |
157 SkIRect rectInSubset(const SkIRect& otherScaledImageRect); | |
158 }; | |
159 | |
160 NativeImageSkia(const SkBitmap& image, float resolutionScale, const SkBitmap
& resizedImage, const ImageResourceInfo&, int resizeRequests); | |
161 | |
162 // Returns true if the given resize operation should either resize the whole | |
163 // image and cache it, or resize just the part it needs and throw the result | |
164 // away. | |
165 // | |
166 // Calling this function may increment a request count that can change the | |
167 // result of subsequent calls. | |
168 // | |
169 // On the one hand, if only a small subset is desired, then we will waste a | |
170 // lot of time resampling the entire thing, so we only want to do exactly | |
171 // what's required. On the other hand, resampling the entire bitmap is | |
172 // better if we're going to be using it more than once (like a bitmap | |
173 // scrolling on and off the screen. Since we only cache when doing the | |
174 // entire thing, it's best to just do it up front. | |
175 bool shouldCacheResampling(const SkISize& scaledImageSize, const SkIRect& sc
aledImageSubset) const; | |
176 | |
177 ResamplingMode computeResamplingMode(const SkMatrix&, float srcWidth, float
srcHeight, float destWidth, float destHeight) const; | |
178 SkBitmap extractScaledImageFragment(const SkRect& srcRect, float scaleX, flo
at scaleY, SkRect* scaledSrcRect) const; | |
179 void drawResampledBitmap(GraphicsContext*, SkPaint&, const SkRect& srcRect,
const SkRect& destRect) const; | |
180 | |
181 // The original image. | |
182 SkBitmap m_image; | |
183 float m_resolutionScale; | |
184 | |
185 // The cached bitmap fragment. This is a subset of the scaled version of | |
186 // |m_image|. empty() returns true if there is no cached image. | |
187 mutable SkBitmap m_resizedImage; | |
188 | |
189 // References how many times that the image size has been requested for | |
190 // the last size. | |
191 // | |
192 // Every time we get a call to shouldCacheResampling, if it matches the | |
193 // m_cachedImageInfo, we'll increment the counter, and if not, we'll reset | |
194 // the counter and save the dimensions. | |
195 // | |
196 // This allows us to see if many requests have been made for the same | |
197 // resized image, we know that we should probably cache it, even if all of | |
198 // those requests individually are small and would not otherwise be cached. | |
199 // | |
200 // We also track scaling information and destination subset for the scaled | |
201 // image. See comments for ImageResourceInfo. | |
202 mutable ImageResourceInfo m_cachedImageInfo; | |
203 mutable int m_resizeRequests; | |
204 }; | |
205 | |
206 } | |
207 #endif // NativeImageSkia_h | |
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