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