OLD | NEW |
1 /* | 1 /* |
2 * Copyright 2013 Google Inc. | 2 * Copyright 2013 Google Inc. |
3 * | 3 * |
4 * Use of this source code is governed by a BSD-style license that can be | 4 * Use of this source code is governed by a BSD-style license that can be |
5 * found in the LICENSE file. | 5 * found in the LICENSE file. |
6 */ | 6 */ |
7 | 7 |
8 #ifndef SkDecodingImageGenerator_DEFINED | 8 #ifndef SkDecodingImageGenerator_DEFINED |
9 #define SkDecodingImageGenerator_DEFINED | 9 #define SkDecodingImageGenerator_DEFINED |
10 | 10 |
11 #include "SkDiscardableMemory.h" | 11 #include "SkBitmap.h" |
12 #include "SkImageGenerator.h" | 12 #include "SkImageGenerator.h" |
13 #include "SkImageInfo.h" | |
14 | 13 |
15 class SkBitmap; | 14 class SkData; |
16 class SkStreamRewindable; | 15 class SkStreamRewindable; |
17 | 16 |
18 /** | 17 /** |
19 * Calls into SkImageDecoder::DecodeMemoryToTarget to implement a | 18 * An implementation of SkImageGenerator that calls into |
20 * SkImageGenerator | 19 * SkImageDecoder. |
21 */ | 20 */ |
22 class SkDecodingImageGenerator : public SkImageGenerator { | 21 class SkDecodingImageGenerator : public SkImageGenerator { |
23 public: | 22 public: |
24 /* | 23 virtual ~SkDecodingImageGenerator(); |
25 * The constructor will take a reference to the SkData. The | 24 virtual SkData* refEncodedData() SK_OVERRIDE; |
26 * destructor will unref() it. | 25 // This implementaion of getInfo() always returns true. |
| 26 virtual bool getInfo(SkImageInfo* info) SK_OVERRIDE; |
| 27 virtual bool getPixels(const SkImageInfo& info, |
| 28 void* pixels, |
| 29 size_t rowBytes) SK_OVERRIDE; |
| 30 /** |
| 31 * These options will be passed on to the image decoder. The |
| 32 * defaults are sensible. |
| 33 * |
| 34 * @param fSampleSize If set to > 1, tells the decoder to return a |
| 35 * smaller than original bitmap, sampling 1 pixel for |
| 36 * every size pixels. e.g. if sample size is set to 3, |
| 37 * then the returned bitmap will be 1/3 as wide and high, |
| 38 * and will contain 1/9 as many pixels as the original. |
| 39 * Note: this is a hint, and the codec may choose to |
| 40 * ignore this, or only approximate the sample size. |
| 41 * |
| 42 * @param fDitherImage Set to true if the the decoder should try to |
| 43 * dither the resulting image when decoding to a smaller |
| 44 * color-space. The default is true. |
| 45 * |
| 46 * @param fRequestedColorType If not given, then use whichever |
| 47 * config the decoder wants. Else try to use this color |
| 48 * type. If the decoder won't support this color type, |
| 49 * SkDecodingImageGenerator::Create will return |
| 50 * NULL. kIndex_8_SkColorType is not supported. |
27 */ | 51 */ |
28 explicit SkDecodingImageGenerator(SkData* data); | 52 struct Options { |
| 53 Options() |
| 54 : fSampleSize(1) |
| 55 , fDitherImage(true) |
| 56 , fUseRequestedColorType(false) |
| 57 , fRequestedColorType() { } |
| 58 Options(int sampleSize, bool dither) |
| 59 : fSampleSize(sampleSize) |
| 60 , fDitherImage(dither) |
| 61 , fUseRequestedColorType(false) |
| 62 , fRequestedColorType() { } |
| 63 Options(int sampleSize, bool dither, SkColorType colorType) |
| 64 : fSampleSize(sampleSize) |
| 65 , fDitherImage(dither) |
| 66 , fUseRequestedColorType(true) |
| 67 , fRequestedColorType(colorType) { } |
| 68 const int fSampleSize; |
| 69 const bool fDitherImage; |
| 70 const bool fUseRequestedColorType; |
| 71 const SkColorType fRequestedColorType; |
| 72 }; |
29 | 73 |
30 /* | 74 /** |
31 * The SkData version of this constructor is preferred. If the | 75 * These two functions return a SkImageGenerator that calls into |
32 * stream has an underlying SkData (such as a SkMemoryStream) | 76 * SkImageDecoder. They return NULL on failure. |
33 * pass that in. | |
34 * | 77 * |
35 * This object will unref the stream when done. Since streams | 78 * The SkData version of this function is preferred. If the stream |
36 * have internal state (position), the caller should not pass a | 79 * has an underlying SkData (such as a SkMemoryStream) pass that in. |
37 * shared stream in. Pass either a new duplicated stream in or | 80 * |
38 * transfer ownership of the stream. In the latter case, be sure | 81 * This object will unref the stream when done or on failure. Since |
39 * that there are no other consumers of the stream who will | 82 * streams have internal state (position), the caller should not pass |
40 * modify the stream's position. This constructor asserts | 83 * a shared stream in. Pass either a new duplicated stream in or |
| 84 * transfer ownership of the stream. This factory asserts |
41 * stream->unique(). | 85 * stream->unique(). |
42 * | 86 * |
43 * For example: | 87 * For example: |
44 * SkStreamRewindable* stream; | 88 * SkStreamRewindable* stream; |
45 * ... | 89 * ... |
46 * SkImageGenerator* gen | 90 * SkImageGenerator* gen |
47 * = SkNEW_ARGS(SkDecodingImageGenerator, | 91 * = SkDecodingImageGenerator::Create( |
48 * (stream->duplicate())); | 92 * stream->duplicate(), SkDecodingImageGenerator::Options()); |
49 * ... | 93 * ... |
50 * SkDELETE(gen); | 94 * SkDELETE(gen); |
| 95 * |
| 96 * @param Options (see above) |
| 97 * |
| 98 * @return NULL on failure, a new SkImageGenerator on success. |
51 */ | 99 */ |
52 explicit SkDecodingImageGenerator(SkStreamRewindable* stream); | 100 static SkImageGenerator* Create(SkStreamRewindable* stream, |
53 | 101 const Options& opt); |
54 virtual ~SkDecodingImageGenerator(); | |
55 | |
56 virtual SkData* refEncodedData() SK_OVERRIDE; | |
57 | |
58 virtual bool getInfo(SkImageInfo* info) SK_OVERRIDE; | |
59 | |
60 virtual bool getPixels(const SkImageInfo& info, | |
61 void* pixels, | |
62 size_t rowBytes) SK_OVERRIDE; | |
63 | 102 |
64 /** | 103 /** |
65 * Install the SkData into the destination bitmap, using a new | 104 * @param data Contains the encoded image data that will be used by |
66 * SkDiscardablePixelRef and a new SkDecodingImageGenerator. | 105 * the SkDecodingImageGenerator. Will be ref()ed by the |
67 * | 106 * SkImageGenerator constructor and and unref()ed on deletion. |
68 * @param data Contains the encoded image data that will be used | |
69 * by the SkDecodingImageGenerator. Will be ref()ed. | |
70 * | |
71 * @param destination Upon success, this bitmap will be | |
72 * configured and have a pixelref installed. | |
73 * | |
74 * @param factory If not NULL, this object will be used as a | |
75 * source of discardable memory when decoding. If NULL, then | |
76 * SkDiscardableMemory::Create() will be called. | |
77 * | |
78 * @return true iff successful. | |
79 */ | 107 */ |
80 static bool Install(SkData* data, SkBitmap* destination, | 108 static SkImageGenerator* Create(SkData* data, const Options& opt); |
81 SkDiscardableMemory::Factory* factory = NULL); | |
82 /** | |
83 * Install the stream into the destination bitmap, using a new | |
84 * SkDiscardablePixelRef and a new SkDecodingImageGenerator. | |
85 * | |
86 * The SkData version of this function is preferred. If the | |
87 * stream has an underlying SkData (such as a SkMemoryStream) | |
88 * pass that in. | |
89 * | |
90 * @param stream The source of encoded data that will be passed | |
91 * to the decoder. The installed SkDecodingImageGenerator will | |
92 * unref the stream when done. If false is returned, this | |
93 * function will perform the unref. Since streams have internal | |
94 * state (position), the caller should not pass a shared stream | |
95 * in. Pass either a new duplicated stream in or transfer | |
96 * ownership of the stream. In the latter case, be sure that | |
97 * there are no other consumers of the stream who will modify the | |
98 * stream's position. This function will fail if | |
99 * (!stream->unique()). | |
100 * | |
101 * @param destination Upon success, this bitmap will be | |
102 * configured and have a pixelref installed. | |
103 * | |
104 * @param factory If not NULL, this object will be used as a | |
105 * source of discardable memory when decoding. If NULL, then | |
106 * SkDiscardableMemory::Create() will be called. | |
107 * | |
108 * @return true iff successful. | |
109 */ | |
110 static bool Install(SkStreamRewindable* stream, SkBitmap* destination, | |
111 SkDiscardableMemory::Factory* factory = NULL); | |
112 | 109 |
113 private: | 110 private: |
114 SkData* fData; | 111 SkData* fData; |
115 SkStreamRewindable* fStream; | 112 SkStreamRewindable* fStream; |
116 SkImageInfo fInfo; | 113 const SkImageInfo fInfo; |
117 bool fHasInfo; | 114 const int fSampleSize; |
118 bool fDoCopyTo; | 115 const bool fDitherImage; |
| 116 const SkBitmap::Config fRequestedConfig; |
| 117 SkDecodingImageGenerator(SkData* data, |
| 118 SkStreamRewindable* stream, |
| 119 const SkImageInfo& info, |
| 120 int sampleSize, |
| 121 bool ditherImage, |
| 122 SkBitmap::Config requestedConfig); |
| 123 static SkImageGenerator* Create(SkData*, SkStreamRewindable*, |
| 124 const Options&); |
| 125 typedef SkImageGenerator INHERITED; |
119 }; | 126 }; |
| 127 |
| 128 // // Example of most basic use case: |
| 129 // |
| 130 // bool install_data(SkData* data, SkBitmap* dst) { |
| 131 // return SkInstallDiscardablePixelRef( |
| 132 // SkDecodingImageGenerator::Create( |
| 133 // data, SkDecodingImageGenerator::Options()), dst, NULL); |
| 134 // } |
| 135 // bool install_stream(SkStreamRewindable* stream, SkBitmap* dst) { |
| 136 // return SkInstallDiscardablePixelRef( |
| 137 // SkDecodingImageGenerator::Create( |
| 138 // stream, SkDecodingImageGenerator::Options()), dst, NULL); |
| 139 // } |
| 140 |
120 #endif // SkDecodingImageGenerator_DEFINED | 141 #endif // SkDecodingImageGenerator_DEFINED |
OLD | NEW |