1 /* 2 * Copyright 2013 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef SkImageGenerator_DEFINED 9 #define SkImageGenerator_DEFINED 10 11 #include "SkColor.h" 12 #include "SkImageInfo.h" 13 14 class SkBitmap; 15 class SkData; 16 class SkImageGenerator; 17 18 /** 19 * Takes ownership of SkImageGenerator. If this method fails for 20 * whatever reason, it will return false and immediatetely delete 21 * the generator. If it succeeds, it will modify destination 22 * bitmap. 23 * 24 * If generator is NULL, will safely return false. 25 * 26 * If this fails or when the SkDiscardablePixelRef that is 27 * installed into destination is destroyed, it will call 28 * SkDELETE() on the generator. Therefore, generator should be 29 * allocated with SkNEW() or SkNEW_ARGS(). 30 * 31 * @param destination Upon success, this bitmap will be 32 * configured and have a pixelref installed. 33 * 34 * @return true iff successful. 35 */ 36 SK_API bool SkInstallDiscardablePixelRef(SkImageGenerator*, SkBitmap* destination); 37 38 39 /** 40 * An interface that allows a purgeable PixelRef (such as a 41 * SkDiscardablePixelRef) to decode and re-decode an image as needed. 42 */ 43 class SK_API SkImageGenerator { 44 public: 45 /** 46 * The PixelRef which takes ownership of this SkImageGenerator 47 * will call the image generator's destructor. 48 */ 49 virtual ~SkImageGenerator() { } 50 51 #ifdef SK_SUPPORT_LEGACY_IMAGEGENERATORAPI 52 virtual SkData* refEncodedData() { return this->onRefEncodedData(); } 53 virtual bool getInfo(SkImageInfo* info) { return this->onGetInfo(info); } 54 virtual bool getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes) { 55 return this->onGetPixels(info, pixels, rowBytes, NULL, NULL); 56 } 57 #else 58 /** 59 * Return a ref to the encoded (i.e. compressed) representation, 60 * of this data. 61 * 62 * If non-NULL is returned, the caller is responsible for calling 63 * unref() on the data when it is finished. 64 */ 65 SkData* refEncodedData() { return this->onRefEncodedData(); } 66 67 /** 68 * Return some information about the image, allowing the owner of 69 * this object to allocate pixels. 70 * 71 * Repeated calls to this function should give the same results, 72 * allowing the PixelRef to be immutable. 73 * 74 * @return false if anything goes wrong. 75 */ 76 bool getInfo(SkImageInfo* info); 77 78 /** 79 * Decode into the given pixels, a block of memory of size at 80 * least (info.fHeight - 1) * rowBytes + (info.fWidth * 81 * bytesPerPixel) 82 * 83 * Repeated calls to this function should give the same results, 84 * allowing the PixelRef to be immutable. 85 * 86 * @param info A description of the format (config, size) 87 * expected by the caller. This can simply be identical 88 * to the info returned by getInfo(). 89 * 90 * This contract also allows the caller to specify 91 * different output-configs, which the implementation can 92 * decide to support or not. 93 * 94 * If info is kIndex8_SkColorType, then the caller must provide storage for up to 256 95 * SkPMColor values in ctable. On success the generator must copy N colors into that storage, 96 * (where N is the logical number of table entries) and set ctableCount to N. 97 * 98 * If info is not kIndex8_SkColorType, then the last two parameters may be NULL. If ctableCount 99 * is not null, it will be set to 0. 100 * 101 * @return false if anything goes wrong or if the image info is 102 * unsupported. 103 */ 104 bool getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, 105 SkPMColor ctable[], int* ctableCount); 106 107 /** 108 * Simplified version of getPixels() that asserts that info is NOT kIndex8_SkColorType. 109 */ 110 bool getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes); 111 #endif 112 113 /** 114 * If planes or rowBytes is NULL or if any entry in planes is NULL or if any entry in rowBytes 115 * is 0, this imagegenerator should output the sizes and return true if it can efficiently 116 * return YUV planar data. If it cannot, it should return false. Note that either planes and 117 * rowBytes are both fully defined and non NULL/non 0 or they are both NULL or have NULL or 0 118 * entries only. Having only partial planes/rowBytes information is not supported. 119 * 120 * If all planes and rowBytes entries are non NULL or non 0, then it should copy the 121 * associated YUV data into those planes of memory supplied by the caller. It should validate 122 * that the sizes match what it expected. If the sizes do not match, it should return false. 123 */ 124 bool getYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3], 125 SkYUVColorSpace* colorSpace); 126 127 protected: 128 virtual SkData* onRefEncodedData(); 129 virtual bool onGetInfo(SkImageInfo* info); 130 virtual bool onGetPixels(const SkImageInfo& info, 131 void* pixels, size_t rowBytes, 132 SkPMColor ctable[], int* ctableCount); 133 virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3]); 134 virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3], 135 SkYUVColorSpace* colorSpace); 136 }; 137 138 #endif // SkImageGenerator_DEFINED 139
