SkPicture.h revision 14bdd527eebb3616227ef37a9ed23bc450a8bb5a
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 17class SkBBoxHierarchy; 18class SkCanvas; 19class SkDrawPictureCallback; 20class SkData; 21class SkPicturePlayback; 22class SkPictureRecord; 23class SkStream; 24class SkWStream; 25 26struct 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*/ 33class SK_API SkPicture : public SkRefCnt { 34public: 35 SK_DECLARE_INST_COUNT(SkPicture) 36 37 // AccelData provides a base class for device-specific acceleration 38 // data. It is added to the picture via a call to a device's optimize 39 // method. 40 class AccelData : public SkRefCnt { 41 public: 42 typedef uint8_t Domain; 43 typedef uint32_t Key; 44 45 AccelData(Key key) : fKey(key) { } 46 47 const Key& getKey() const { return fKey; } 48 49 // This entry point allows user's to get a unique domain prefix 50 // for their keys 51 static Domain GenerateDomain(); 52 private: 53 Key fKey; 54 55 typedef SkRefCnt INHERITED; 56 }; 57 58 /** The constructor prepares the picture to record. 59 @param width the width of the virtual device the picture records. 60 @param height the height of the virtual device the picture records. 61 */ 62 SkPicture(); 63 /** Make a copy of the contents of src. If src records more drawing after 64 this call, those elements will not appear in this picture. 65 */ 66 SkPicture(const SkPicture& src); 67 68 /** PRIVATE / EXPERIMENTAL -- do not call */ 69 void EXPERIMENTAL_addAccelData(const AccelData* data) { 70 SkRefCnt_SafeAssign(fAccelData, data); 71 } 72 /** PRIVATE / EXPERIMENTAL -- do not call */ 73 const AccelData* EXPERIMENTAL_getAccelData(AccelData::Key key) const { 74 if (NULL != fAccelData && fAccelData->getKey() == key) { 75 return fAccelData; 76 } 77 return NULL; 78 } 79 80 /** 81 * Function signature defining a function that sets up an SkBitmap from encoded data. On 82 * success, the SkBitmap should have its Config, width, height, rowBytes and pixelref set. 83 * If the installed pixelref has decoded the data into pixels, then the src buffer need not be 84 * copied. If the pixelref defers the actual decode until its lockPixels() is called, then it 85 * must make a copy of the src buffer. 86 * @param src Encoded data. 87 * @param length Size of the encoded data, in bytes. 88 * @param dst SkBitmap to install the pixel ref on. 89 * @param bool Whether or not a pixel ref was successfully installed. 90 */ 91 typedef bool (*InstallPixelRefProc)(const void* src, size_t length, SkBitmap* dst); 92 93 /** 94 * Recreate a picture that was serialized into a stream. 95 * @param SkStream Serialized picture data. 96 * @param proc Function pointer for installing pixelrefs on SkBitmaps representing the 97 * encoded bitmap data from the stream. 98 * @return A new SkPicture representing the serialized data, or NULL if the stream is 99 * invalid. 100 */ 101 static SkPicture* CreateFromStream(SkStream*, 102 InstallPixelRefProc proc = &SkImageDecoder::DecodeMemory); 103 104 /** 105 * Recreate a picture that was serialized into a buffer. If the creation requires bitmap 106 * decoding, the decoder must be set on the SkReadBuffer parameter by calling 107 * SkReadBuffer::setBitmapDecoder() before calling SkPicture::CreateFromBuffer(). 108 * @param SkReadBuffer Serialized picture data. 109 * @return A new SkPicture representing the serialized data, or NULL if the buffer is 110 * invalid. 111 */ 112 static SkPicture* CreateFromBuffer(SkReadBuffer&); 113 114 virtual ~SkPicture(); 115 116 /** 117 * Swap the contents of the two pictures. Guaranteed to succeed. 118 */ 119 void swap(SkPicture& other); 120 121 /** 122 * Creates a thread-safe clone of the picture that is ready for playback. 123 */ 124 SkPicture* clone() const; 125 126 /** 127 * Creates multiple thread-safe clones of this picture that are ready for 128 * playback. The resulting clones are stored in the provided array of 129 * SkPictures. 130 */ 131 void clone(SkPicture* pictures, int count) const; 132 133 enum RecordingFlags { 134 /* This flag specifies that when clipPath() is called, the path will 135 be faithfully recorded, but the recording canvas' current clip will 136 only see the path's bounds. This speeds up the recording process 137 without compromising the fidelity of the playback. The only side- 138 effect for recording is that calling getTotalClip() or related 139 clip-query calls will reflect the path's bounds, not the actual 140 path. 141 */ 142 kUsePathBoundsForClip_RecordingFlag = 0x01, 143 /* This flag causes the picture to compute bounding boxes and build 144 up a spatial hierarchy (currently an R-Tree), plus a tree of Canvas' 145 usually stack-based clip/etc state. This requires an increase in 146 recording time (often ~2x; likely more for very complex pictures), 147 but allows us to perform much faster culling at playback time, and 148 completely avoid some unnecessary clips and other operations. This 149 is ideal for tiled rendering, or any other situation where you're 150 drawing a fraction of a large scene into a smaller viewport. 151 152 In most cases the record cost is offset by the playback improvement 153 after a frame or two of tiled rendering (and complex pictures that 154 induce the worst record times will generally get the largest 155 speedups at playback time). 156 157 Note: Currently this is not serializable, the bounding data will be 158 discarded if you serialize into a stream and then deserialize. 159 */ 160 kOptimizeForClippedPlayback_RecordingFlag = 0x02, 161 }; 162 163 /** Returns the canvas that records the drawing commands. 164 @param width the base width for the picture, as if the recording 165 canvas' bitmap had this width. 166 @param height the base width for the picture, as if the recording 167 canvas' bitmap had this height. 168 @param recordFlags optional flags that control recording. 169 @return the picture canvas. 170 */ 171 SkCanvas* beginRecording(int width, int height, uint32_t recordFlags = 0); 172 173 /** Returns the recording canvas if one is active, or NULL if recording is 174 not active. This does not alter the refcnt on the canvas (if present). 175 */ 176 SkCanvas* getRecordingCanvas() const; 177 /** Signal that the caller is done recording. This invalidates the canvas 178 returned by beginRecording/getRecordingCanvas, and prepares the picture 179 for drawing. Note: this happens implicitly the first time the picture 180 is drawn. 181 */ 182 void endRecording(); 183 184 /** Replays the drawing commands on the specified canvas. This internally 185 calls endRecording() if that has not already been called. 186 @param canvas the canvas receiving the drawing commands. 187 */ 188 void draw(SkCanvas* canvas, SkDrawPictureCallback* = NULL); 189 190 /** Return the width of the picture's recording canvas. This 191 value reflects what was passed to setSize(), and does not necessarily 192 reflect the bounds of what has been recorded into the picture. 193 @return the width of the picture's recording canvas 194 */ 195 int width() const { return fWidth; } 196 197 /** Return the height of the picture's recording canvas. This 198 value reflects what was passed to setSize(), and does not necessarily 199 reflect the bounds of what has been recorded into the picture. 200 @return the height of the picture's recording canvas 201 */ 202 int height() const { return fHeight; } 203 204 /** 205 * Function to encode an SkBitmap to an SkData. A function with this 206 * signature can be passed to serialize() and SkWriteBuffer. 207 * Returning NULL will tell the SkWriteBuffer to use 208 * SkBitmap::flatten() to store the bitmap. 209 * 210 * @param pixelRefOffset DEPRECATED -- caller assumes it will return 0. 211 * @return SkData If non-NULL, holds encoded data representing the passed 212 * in bitmap. The caller is responsible for calling unref(). 213 */ 214 typedef SkData* (*EncodeBitmap)(size_t* pixelRefOffset, const SkBitmap& bm); 215 216 /** 217 * Serialize to a stream. If non NULL, encoder will be used to encode 218 * any bitmaps in the picture. 219 * encoder will never be called with a NULL pixelRefOffset. 220 */ 221 void serialize(SkWStream*, EncodeBitmap encoder = NULL) const; 222 223 /** 224 * Serialize to a buffer. 225 */ 226 void flatten(SkWriteBuffer&) const; 227 228 /** 229 * Returns true if any bitmaps may be produced when this SkPicture 230 * is replayed. 231 * Returns false if called while still recording. 232 */ 233 bool willPlayBackBitmaps() const; 234 235#ifdef SK_BUILD_FOR_ANDROID 236 /** Signals that the caller is prematurely done replaying the drawing 237 commands. This can be called from a canvas virtual while the picture 238 is drawing. Has no effect if the picture is not drawing. 239 @deprecated preserving for legacy purposes 240 */ 241 void abortPlayback(); 242#endif 243 244 /** Return true if the SkStream/Buffer represents a serialized picture, and 245 fills out SkPictInfo. After this function returns, the data source is not 246 rewound so it will have to be manually reset before passing to 247 CreateFromStream or CreateFromBuffer. Note, CreateFromStream and 248 CreateFromBuffer perform this check internally so these entry points are 249 intended for stand alone tools. 250 If false is returned, SkPictInfo is unmodified. 251 */ 252 static bool InternalOnly_StreamIsSKP(SkStream*, SkPictInfo*); 253 static bool InternalOnly_BufferIsSKP(SkReadBuffer&, SkPictInfo*); 254 255 /** Enable/disable all the picture recording optimizations (i.e., 256 those in SkPictureRecord). It is mainly intended for testing the 257 existing optimizations (i.e., to actually have the pattern 258 appear in an .skp we have to disable the optimization). Call right 259 after 'beginRecording'. 260 */ 261 void internalOnly_EnableOpts(bool enableOpts); 262 263protected: 264 // V2 : adds SkPixelRef's generation ID. 265 // V3 : PictInfo tag at beginning, and EOF tag at the end 266 // V4 : move SkPictInfo to be the header 267 // V5 : don't read/write FunctionPtr on cross-process (we can detect that) 268 // V6 : added serialization of SkPath's bounds (and packed its flags tighter) 269 // V7 : changed drawBitmapRect(IRect) to drawBitmapRectToRect(Rect) 270 // V8 : Add an option for encoding bitmaps 271 // V9 : Allow the reader and writer of an SKP disagree on whether to support 272 // SK_SUPPORT_HINTING_SCALE_FACTOR 273 // V10: add drawRRect, drawOval, clipRRect 274 // V11: modify how readBitmap and writeBitmap store their info. 275 // V12: add conics to SkPath, use new SkPathRef flattening 276 // V13: add flag to drawBitmapRectToRect 277 // parameterize blurs by sigma rather than radius 278 // V14: Add flags word to PathRef serialization 279 // V15: Remove A1 bitmpa config (and renumber remaining configs) 280 // V16: Move SkPath's isOval flag to SkPathRef 281 // V17: SkPixelRef now writes SkImageInfo 282 // V18: SkBitmap now records x,y for its pixelref origin, instead of offset. 283 // V19: encode matrices and regions into the ops stream 284 // V20: added bool to SkPictureImageFilter's serialization (to allow SkPicture serialization) 285 // V21: add pushCull, popCull 286 // V22: SK_PICT_FACTORY_TAG's size is now the chunk size in bytes 287 288 // Note: If the picture version needs to be increased then please follow the 289 // steps to generate new SKPs in (only accessible to Googlers): http://goo.gl/qATVcw 290 291 // Only SKPs within the min/current picture version range (inclusive) can be read. 292 static const uint32_t MIN_PICTURE_VERSION = 19; 293 static const uint32_t CURRENT_PICTURE_VERSION = 22; 294 295 // fPlayback, fRecord, fWidth & fHeight are protected to allow derived classes to 296 // install their own SkPicturePlayback-derived players,SkPictureRecord-derived 297 // recorders and set the picture size 298 SkPicturePlayback* fPlayback; 299 SkPictureRecord* fRecord; 300 int fWidth, fHeight; 301 const AccelData* fAccelData; 302 303 // Create a new SkPicture from an existing SkPicturePlayback. Ref count of 304 // playback is unchanged. 305 SkPicture(SkPicturePlayback*, int width, int height); 306 307 // For testing. Derived classes may instantiate an alternate 308 // SkBBoxHierarchy implementation 309 virtual SkBBoxHierarchy* createBBoxHierarchy() const; 310private: 311 void createHeader(SkPictInfo* info) const; 312 static bool IsValidPictInfo(const SkPictInfo& info); 313 314 friend class SkFlatPicture; 315 friend class SkPicturePlayback; 316 317 typedef SkRefCnt INHERITED; 318}; 319 320/** 321 * Subclasses of this can be passed to canvas.drawPicture. During the drawing 322 * of the picture, this callback will periodically be invoked. If its 323 * abortDrawing() returns true, then picture playback will be interrupted. 324 * 325 * The resulting drawing is undefined, as there is no guarantee how often the 326 * callback will be invoked. If the abort happens inside some level of nested 327 * calls to save(), restore will automatically be called to return the state 328 * to the same level it was before the drawPicture call was made. 329 */ 330class SK_API SkDrawPictureCallback { 331public: 332 SkDrawPictureCallback() {} 333 virtual ~SkDrawPictureCallback() {} 334 335 virtual bool abortDrawing() = 0; 336}; 337 338#endif 339