1 /* 2 * Copyright 2012 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 SkImage_DEFINED 9 #define SkImage_DEFINED 10 11 #include "SkImageInfo.h" 12 #include "SkImageEncoder.h" 13 #include "SkRefCnt.h" 14 #include "SkScalar.h" 15 #include "SkShader.h" 16 17 class SkData; 18 class SkCanvas; 19 class SkImageGenerator; 20 class SkPaint; 21 class GrContext; 22 class GrTexture; 23 24 /** 25 * SkImage is an abstraction for drawing a rectagle of pixels, though the 26 * particular type of image could be actually storing its data on the GPU, or 27 * as drawing commands (picture or PDF or otherwise), ready to be played back 28 * into another canvas. 29 * 30 * The content of SkImage is always immutable, though the actual storage may 31 * change, if for example that image can be re-created via encoded data or 32 * other means. 33 */ 34 class SK_API SkImage : public SkRefCnt { 35 public: 36 SK_DECLARE_INST_COUNT(SkImage) 37 38 typedef SkImageInfo Info; 39 40 static SkImage* NewRasterCopy(const Info&, const void* pixels, size_t rowBytes); 41 static SkImage* NewRasterData(const Info&, SkData* pixels, size_t rowBytes); 42 43 /** 44 * GrTexture is a more logical parameter for this factory, but its 45 * interactions with scratch cache still has issues, so for now we take 46 * SkBitmap instead. This will be changed in the future. skbug.com/1449 47 */ 48 static SkImage* NewTexture(const SkBitmap&); 49 isOpaque()50 virtual bool isOpaque() const { return false; } 51 52 /** 53 * Construct a new SkImage based on the given ImageGenerator. 54 * This function will always take ownership of the passed 55 * ImageGenerator. Returns NULL on error. 56 */ 57 static SkImage* NewFromGenerator(SkImageGenerator*); 58 width()59 int width() const { return fWidth; } height()60 int height() const { return fHeight; } uniqueID()61 uint32_t uniqueID() const { return fUniqueID; } 62 63 /** 64 * Return the GrTexture that stores the image pixels. Calling getTexture 65 * does not affect the reference count of the GrTexture object. 66 * Will return NULL if the image does not use a texture. 67 */ 68 GrTexture* getTexture(); 69 70 virtual SkShader* newShader(SkShader::TileMode, 71 SkShader::TileMode, 72 const SkMatrix* localMatrix = NULL) const; 73 74 /** 75 * If the image has direct access to its pixels (i.e. they are in local 76 * RAM) return the (const) address of those pixels, and if not null, return 77 * the ImageInfo and rowBytes. The returned address is only valid while 78 * the image object is in scope. 79 * 80 * On failure, returns NULL and the info and rowBytes parameters are 81 * ignored. 82 */ 83 const void* peekPixels(SkImageInfo* info, size_t* rowBytes) const; 84 85 /** 86 * Encode the image's pixels and return the result as a new SkData, which 87 * the caller must manage (i.e. call unref() when they are done). 88 * 89 * If the image type cannot be encoded, or the requested encoder type is 90 * not supported, this will return NULL. 91 */ 92 SkData* encode(SkImageEncoder::Type t = SkImageEncoder::kPNG_Type, 93 int quality = 80) const; 94 95 void draw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*) const; 96 97 /** 98 * Draw the image, cropped to the src rect, to the dst rect of a canvas. 99 * If src is larger than the bounds of the image, the rest of the image is 100 * filled with transparent black pixels. 101 * 102 * See SkCanvas::drawBitmapRectToRect for similar behavior. 103 */ 104 void draw(SkCanvas*, const SkRect* src, const SkRect& dst, const SkPaint*) const; 105 106 protected: SkImage(int width,int height)107 SkImage(int width, int height) : 108 fWidth(width), 109 fHeight(height), 110 fUniqueID(NextUniqueID()) { 111 112 SkASSERT(width >= 0); 113 SkASSERT(height >= 0); 114 } 115 116 private: 117 const int fWidth; 118 const int fHeight; 119 const uint32_t fUniqueID; 120 121 static uint32_t NextUniqueID(); 122 123 typedef SkRefCnt INHERITED; 124 125 /** 126 * Return a copy of the image's pixels, limiting them to the subset 127 * rectangle's intersection wit the image bounds. If subset is NULL, then 128 * the entire image will be considered. 129 * 130 * If the bitmap's pixels have already been allocated, then readPixels() 131 * will succeed only if it can support converting the image's pixels into 132 * the bitmap's ColorType/AlphaType. Any pixels in the bitmap that do not 133 * intersect with the image's bounds and the subset (if not null) will be 134 * left untouched. 135 * 136 * If the bitmap is initially empty/unallocated, then it will be allocated 137 * using the default allocator, and the ColorType/AlphaType will be chosen 138 * to most closely fit the image's configuration. 139 * 140 * On failure, false will be returned, and bitmap will unmodified. 141 */ 142 // On ice for now: 143 // - should it respect the particular colortype/alphatype of the src 144 // - should it have separate entrypoints for preallocated and not bitmaps? 145 // - isn't it enough to allow the caller to draw() the image into a canvas? 146 bool readPixels(SkBitmap* bitmap, const SkIRect* subset = NULL) const; 147 }; 148 149 #endif 150