1 2 /* 3 * Copyright 2007 The Android Open Source Project 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 #ifndef SkPicture_DEFINED 11 #define SkPicture_DEFINED 12 13 #include "SkBitmap.h" 14 #include "SkImageDecoder.h" 15 #include "SkRefCnt.h" 16 17 class SkBBoxHierarchy; 18 class SkCanvas; 19 class SkDrawPictureCallback; 20 class SkData; 21 class SkPicturePlayback; 22 class SkPictureRecord; 23 class SkStream; 24 class SkWStream; 25 26 struct SkPictInfo; 27 28 /** \class SkPicture 29 30 The SkPicture class records the drawing commands made to a canvas, to 31 be played back at a later time. 32 */ 33 class SK_API SkPicture : public SkRefCnt { 34 public: 35 SK_DECLARE_INST_COUNT(SkPicture) 36 37 /** The constructor prepares the picture to record. 38 @param width the width of the virtual device the picture records. 39 @param height the height of the virtual device the picture records. 40 */ 41 SkPicture(); 42 /** Make a copy of the contents of src. If src records more drawing after 43 this call, those elements will not appear in this picture. 44 */ 45 SkPicture(const SkPicture& src); 46 47 /** 48 * Function signature defining a function that sets up an SkBitmap from encoded data. On 49 * success, the SkBitmap should have its Config, width, height, rowBytes and pixelref set. 50 * If the installed pixelref has decoded the data into pixels, then the src buffer need not be 51 * copied. If the pixelref defers the actual decode until its lockPixels() is called, then it 52 * must make a copy of the src buffer. 53 * @param src Encoded data. 54 * @param length Size of the encoded data, in bytes. 55 * @param dst SkBitmap to install the pixel ref on. 56 * @param bool Whether or not a pixel ref was successfully installed. 57 */ 58 typedef bool (*InstallPixelRefProc)(const void* src, size_t length, SkBitmap* dst); 59 60 /** 61 * Recreate a picture that was serialized into a stream. 62 * @param SkStream Serialized picture data. 63 * @param proc Function pointer for installing pixelrefs on SkBitmaps representing the 64 * encoded bitmap data from the stream. 65 * @return A new SkPicture representing the serialized data, or NULL if the stream is 66 * invalid. 67 */ 68 static SkPicture* CreateFromStream(SkStream*, 69 InstallPixelRefProc proc = &SkImageDecoder::DecodeMemory); 70 71 virtual ~SkPicture(); 72 73 /** 74 * Swap the contents of the two pictures. Guaranteed to succeed. 75 */ 76 void swap(SkPicture& other); 77 78 /** 79 * Creates a thread-safe clone of the picture that is ready for playback. 80 */ 81 SkPicture* clone() const; 82 83 /** 84 * Creates multiple thread-safe clones of this picture that are ready for 85 * playback. The resulting clones are stored in the provided array of 86 * SkPictures. 87 */ 88 void clone(SkPicture* pictures, int count) const; 89 90 enum RecordingFlags { 91 /* This flag specifies that when clipPath() is called, the path will 92 be faithfully recorded, but the recording canvas' current clip will 93 only see the path's bounds. This speeds up the recording process 94 without compromising the fidelity of the playback. The only side- 95 effect for recording is that calling getTotalClip() or related 96 clip-query calls will reflect the path's bounds, not the actual 97 path. 98 */ 99 kUsePathBoundsForClip_RecordingFlag = 0x01, 100 /* This flag causes the picture to compute bounding boxes and build 101 up a spatial hierarchy (currently an R-Tree), plus a tree of Canvas' 102 usually stack-based clip/etc state. This requires an increase in 103 recording time (often ~2x; likely more for very complex pictures), 104 but allows us to perform much faster culling at playback time, and 105 completely avoid some unnecessary clips and other operations. This 106 is ideal for tiled rendering, or any other situation where you're 107 drawing a fraction of a large scene into a smaller viewport. 108 109 In most cases the record cost is offset by the playback improvement 110 after a frame or two of tiled rendering (and complex pictures that 111 induce the worst record times will generally get the largest 112 speedups at playback time). 113 114 Note: Currently this is not serializable, the bounding data will be 115 discarded if you serialize into a stream and then deserialize. 116 */ 117 kOptimizeForClippedPlayback_RecordingFlag = 0x02, 118 /* 119 This flag disables all the picture recording optimizations (i.e., 120 those in SkPictureRecord). It is mainly intended for testing the 121 existing optimizations (i.e., to actually have the pattern 122 appear in an .skp we have to disable the optimization). This 123 option doesn't affect the optimizations controlled by 124 'kOptimizeForClippedPlayback_RecordingFlag'. 125 */ 126 kDisableRecordOptimizations_RecordingFlag = 0x04 127 }; 128 129 /** Returns the canvas that records the drawing commands. 130 @param width the base width for the picture, as if the recording 131 canvas' bitmap had this width. 132 @param height the base width for the picture, as if the recording 133 canvas' bitmap had this height. 134 @param recordFlags optional flags that control recording. 135 @return the picture canvas. 136 */ 137 SkCanvas* beginRecording(int width, int height, uint32_t recordFlags = 0); 138 139 /** Returns the recording canvas if one is active, or NULL if recording is 140 not active. This does not alter the refcnt on the canvas (if present). 141 */ 142 SkCanvas* getRecordingCanvas() const; 143 /** Signal that the caller is done recording. This invalidates the canvas 144 returned by beginRecording/getRecordingCanvas, and prepares the picture 145 for drawing. Note: this happens implicitly the first time the picture 146 is drawn. 147 */ 148 void endRecording(); 149 150 /** Replays the drawing commands on the specified canvas. This internally 151 calls endRecording() if that has not already been called. 152 @param canvas the canvas receiving the drawing commands. 153 */ 154 void draw(SkCanvas* canvas, SkDrawPictureCallback* = NULL); 155 156 /** Return the width of the picture's recording canvas. This 157 value reflects what was passed to setSize(), and does not necessarily 158 reflect the bounds of what has been recorded into the picture. 159 @return the width of the picture's recording canvas 160 */ 161 int width() const { return fWidth; } 162 163 /** Return the height of the picture's recording canvas. This 164 value reflects what was passed to setSize(), and does not necessarily 165 reflect the bounds of what has been recorded into the picture. 166 @return the height of the picture's recording canvas 167 */ 168 int height() const { return fHeight; } 169 170 /** 171 * Function to encode an SkBitmap to an SkData. A function with this 172 * signature can be passed to serialize() and SkOrderedWriteBuffer. 173 * Returning NULL will tell the SkOrderedWriteBuffer to use 174 * SkBitmap::flatten() to store the bitmap. 175 * @param pixelRefOffset Output parameter, telling the deserializer what 176 * offset in the bm's pixelRef corresponds to the encoded data. 177 * @return SkData If non-NULL, holds encoded data representing the passed 178 * in bitmap. The caller is responsible for calling unref(). 179 */ 180 typedef SkData* (*EncodeBitmap)(size_t* pixelRefOffset, const SkBitmap& bm); 181 182 /** 183 * Serialize to a stream. If non NULL, encoder will be used to encode 184 * any bitmaps in the picture. 185 * encoder will never be called with a NULL pixelRefOffset. 186 */ 187 void serialize(SkWStream*, EncodeBitmap encoder = NULL) const; 188 189 #ifdef SK_BUILD_FOR_ANDROID 190 /** Signals that the caller is prematurely done replaying the drawing 191 commands. This can be called from a canvas virtual while the picture 192 is drawing. Has no effect if the picture is not drawing. 193 @deprecated preserving for legacy purposes 194 */ 195 void abortPlayback(); 196 #endif 197 198 protected: 199 // V2 : adds SkPixelRef's generation ID. 200 // V3 : PictInfo tag at beginning, and EOF tag at the end 201 // V4 : move SkPictInfo to be the header 202 // V5 : don't read/write FunctionPtr on cross-process (we can detect that) 203 // V6 : added serialization of SkPath's bounds (and packed its flags tighter) 204 // V7 : changed drawBitmapRect(IRect) to drawBitmapRectToRect(Rect) 205 // V8 : Add an option for encoding bitmaps 206 // V9 : Allow the reader and writer of an SKP disagree on whether to support 207 // SK_SUPPORT_HINTING_SCALE_FACTOR 208 // V10: add drawRRect, drawOval, clipRRect 209 // V11: modify how readBitmap and writeBitmap store their info. 210 // V12: add conics to SkPath, use new SkPathRef flattening 211 static const uint32_t PICTURE_VERSION = 12; 212 213 // fPlayback, fRecord, fWidth & fHeight are protected to allow derived classes to 214 // install their own SkPicturePlayback-derived players,SkPictureRecord-derived 215 // recorders and set the picture size 216 SkPicturePlayback* fPlayback; 217 SkPictureRecord* fRecord; 218 int fWidth, fHeight; 219 220 // Create a new SkPicture from an existing SkPicturePlayback. Ref count of 221 // playback is unchanged. 222 SkPicture(SkPicturePlayback*, int width, int height); 223 224 // For testing. Derived classes may instantiate an alternate 225 // SkBBoxHierarchy implementation 226 virtual SkBBoxHierarchy* createBBoxHierarchy() const; 227 228 // Return true if the SkStream represents a serialized picture, and fills out 229 // SkPictInfo. After this function returns, the SkStream is not rewound; it 230 // will be ready to be parsed to create an SkPicturePlayback. 231 // If false is returned, SkPictInfo is unmodified. 232 static bool StreamIsSKP(SkStream*, SkPictInfo*); 233 private: 234 friend class SkFlatPicture; 235 friend class SkPicturePlayback; 236 237 typedef SkRefCnt INHERITED; 238 }; 239 240 class SkAutoPictureRecord : SkNoncopyable { 241 public: 242 SkAutoPictureRecord(SkPicture* pict, int width, int height, 243 uint32_t recordingFlags = 0) { 244 fPicture = pict; 245 fCanvas = pict->beginRecording(width, height, recordingFlags); 246 } 247 ~SkAutoPictureRecord() { 248 fPicture->endRecording(); 249 } 250 251 /** Return the canvas to draw into for recording into the picture. 252 */ 253 SkCanvas* getRecordingCanvas() const { return fCanvas; } 254 255 private: 256 SkPicture* fPicture; 257 SkCanvas* fCanvas; 258 }; 259 260 /** 261 * Subclasses of this can be passed to canvas.drawPicture. During the drawing 262 * of the picture, this callback will periodically be invoked. If its 263 * abortDrawing() returns true, then picture playback will be interrupted. 264 * 265 * The resulting drawing is undefined, as there is no guarantee how often the 266 * callback will be invoked. If the abort happens inside some level of nested 267 * calls to save(), restore will automatically be called to return the state 268 * to the same level it was before the drawPicture call was made. 269 */ 270 class SK_API SkDrawPictureCallback { 271 public: 272 SkDrawPictureCallback() {} 273 virtual ~SkDrawPictureCallback() {} 274 275 virtual bool abortDrawing() = 0; 276 }; 277 278 #endif 279
