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 SkDeferredCanvas_DEFINED 9 #define SkDeferredCanvas_DEFINED 10 11 #include "SkCanvas.h" 12 #include "SkPixelRef.h" 13 14 class SkDeferredDevice; 15 class SkImage; 16 class SkSurface; 17 18 /** \class SkDeferredCanvas 19 Subclass of SkCanvas that encapsulates an SkPicture or SkGPipe for deferred 20 drawing. The main difference between this class and SkPictureRecord (the 21 canvas provided by SkPicture) is that this is a full drop-in replacement 22 for SkCanvas, while SkPictureRecord only supports draw operations. 23 SkDeferredCanvas will transparently trigger the flushing of deferred 24 draw operations when an attempt is made to access the pixel data. 25 */ 26 class SK_API SkDeferredCanvas : public SkCanvas { 27 public: 28 class SK_API NotificationClient; 29 30 /** Construct a canvas with the specified surface to draw into. 31 This factory must be used for newImageSnapshot to work. 32 @param surface Specifies a surface for the canvas to draw into. 33 */ 34 static SkDeferredCanvas* Create(SkSurface* surface); 35 36 // static SkDeferredCanvas* Create(SkBaseDevice* device); 37 38 virtual ~SkDeferredCanvas(); 39 40 /** 41 * Specify the surface to be used by this canvas. Calling setSurface will 42 * release the previously set surface or device. Takes a reference on the 43 * surface. 44 * 45 * @param surface The surface that the canvas will raw into 46 * @return The surface argument, for convenience. 47 */ 48 SkSurface* setSurface(SkSurface* surface); 49 50 /** 51 * Specify a NotificationClient to be used by this canvas. Calling 52 * setNotificationClient will release the previously set 53 * NotificationClient, if any. SkDeferredCanvas does not take ownership 54 * of the notification client. Therefore user code is resposible 55 * for its destruction. The notification client must be unregistered 56 * by calling setNotificationClient(NULL) if it is destroyed before 57 * this canvas. 58 * Note: Must be called after the device is set with setDevice. 59 * 60 * @param notificationClient interface for dispatching notifications 61 * @return The notificationClient argument, for convenience. 62 */ 63 NotificationClient* setNotificationClient(NotificationClient* notificationClient); 64 65 /** 66 * Enable or disable deferred drawing. When deferral is disabled, 67 * pending draw operations are immediately flushed and from then on, 68 * the SkDeferredCanvas behaves just like a regular SkCanvas. 69 * This method must not be called while the save/restore stack is in use. 70 * @param deferred true/false 71 */ 72 void setDeferredDrawing(bool deferred); 73 74 /** 75 * Returns true if deferred drawing is currenlty enabled. 76 */ 77 bool isDeferredDrawing() const; 78 79 /** 80 * Returns true if the canvas contains a fresh frame. A frame is 81 * considered fresh when its content do not depend on the contents 82 * of the previous frame. For example, if a canvas is cleared before 83 * drawing each frame, the frames will all be considered fresh. 84 * A frame is defined as the graphics image produced by as a result 85 * of all the canvas draws operation executed between two successive 86 * calls to isFreshFrame. The result of isFreshFrame is computed 87 * conservatively, so it may report false negatives. 88 */ 89 bool isFreshFrame() const; 90 91 /** 92 * Returns canvas's size. 93 */ 94 SkISize getCanvasSize() const; 95 96 /** 97 * Returns true if the canvas has recorded draw commands that have 98 * not yet been played back. 99 */ 100 bool hasPendingCommands() const; 101 102 /** 103 * Flushes pending draw commands, if any, and returns an image of the 104 * current state of the surface pixels up to this point. Subsequent 105 * changes to the surface (by drawing into its canvas) will not be 106 * reflected in this image. Will return NULL if the deferred canvas 107 * was not constructed from an SkSurface. 108 */ 109 SkImage* newImageSnapshot(); 110 111 /** 112 * Specify the maximum number of bytes to be allocated for the purpose 113 * of recording draw commands to this canvas. The default limit, is 114 * 64MB. 115 * @param maxStorage The maximum number of bytes to be allocated. 116 */ 117 void setMaxRecordingStorage(size_t maxStorage); 118 119 /** 120 * Returns the number of bytes currently allocated for the purpose of 121 * recording draw commands. 122 */ 123 size_t storageAllocatedForRecording() const; 124 125 /** 126 * Attempt to reduce the storage allocated for recording by evicting 127 * cache resources. 128 * @param bytesToFree minimum number of bytes that should be attempted to 129 * be freed. 130 * @return number of bytes actually freed. 131 */ 132 size_t freeMemoryIfPossible(size_t bytesToFree); 133 134 /** 135 * Specifies the maximum size (in bytes) allowed for a given image to be 136 * rendered using the deferred canvas. 137 */ 138 void setBitmapSizeThreshold(size_t sizeThreshold); 139 size_t getBitmapSizeThreshold() const { return fBitmapSizeThreshold; } 140 141 /** 142 * Executes all pending commands without drawing 143 */ 144 void silentFlush(); 145 146 // Overrides of the SkCanvas interface 147 virtual bool isDrawingToLayer() const SK_OVERRIDE; 148 virtual void clear(SkColor) SK_OVERRIDE; 149 virtual void drawPaint(const SkPaint& paint) SK_OVERRIDE; 150 virtual void drawPoints(PointMode mode, size_t count, const SkPoint pts[], 151 const SkPaint& paint) SK_OVERRIDE; 152 virtual void drawOval(const SkRect&, const SkPaint& paint) SK_OVERRIDE; 153 virtual void drawRect(const SkRect& rect, const SkPaint& paint) SK_OVERRIDE; 154 virtual void drawRRect(const SkRRect&, const SkPaint& paint) SK_OVERRIDE; 155 virtual void drawPath(const SkPath& path, const SkPaint& paint) 156 SK_OVERRIDE; 157 virtual void drawBitmap(const SkBitmap& bitmap, SkScalar left, 158 SkScalar top, const SkPaint* paint) 159 SK_OVERRIDE; 160 virtual void drawBitmapRectToRect(const SkBitmap& bitmap, const SkRect* src, 161 const SkRect& dst, const SkPaint* paint, 162 DrawBitmapRectFlags flags) SK_OVERRIDE; 163 164 virtual void drawBitmapMatrix(const SkBitmap& bitmap, const SkMatrix& m, 165 const SkPaint* paint) SK_OVERRIDE; 166 virtual void drawBitmapNine(const SkBitmap& bitmap, const SkIRect& center, 167 const SkRect& dst, const SkPaint* paint) 168 SK_OVERRIDE; 169 virtual void drawSprite(const SkBitmap& bitmap, int left, int top, 170 const SkPaint* paint) SK_OVERRIDE; 171 virtual void drawVertices(VertexMode vmode, int vertexCount, 172 const SkPoint vertices[], const SkPoint texs[], 173 const SkColor colors[], SkXfermode* xmode, 174 const uint16_t indices[], int indexCount, 175 const SkPaint& paint) SK_OVERRIDE; 176 virtual SkDrawFilter* setDrawFilter(SkDrawFilter* filter) SK_OVERRIDE; 177 178 protected: 179 virtual void willSave() SK_OVERRIDE; 180 virtual SaveLayerStrategy willSaveLayer(const SkRect*, const SkPaint*, SaveFlags) SK_OVERRIDE; 181 virtual void willRestore() SK_OVERRIDE; 182 183 virtual void didConcat(const SkMatrix&) SK_OVERRIDE; 184 virtual void didSetMatrix(const SkMatrix&) SK_OVERRIDE; 185 186 virtual void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&) SK_OVERRIDE; 187 virtual void onDrawText(const void* text, size_t byteLength, SkScalar x, SkScalar y, 188 const SkPaint&) SK_OVERRIDE; 189 virtual void onDrawPosText(const void* text, size_t byteLength, const SkPoint pos[], 190 const SkPaint&) SK_OVERRIDE; 191 virtual void onDrawPosTextH(const void* text, size_t byteLength, const SkScalar xpos[], 192 SkScalar constY, const SkPaint&) SK_OVERRIDE; 193 virtual void onDrawTextOnPath(const void* text, size_t byteLength, const SkPath& path, 194 const SkMatrix* matrix, const SkPaint&) SK_OVERRIDE; 195 virtual void onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y, 196 const SkPaint& paint) SK_OVERRIDE; 197 virtual void onDrawPatch(const SkPoint cubics[12], const SkColor colors[4], 198 const SkPoint texCoords[4], SkXfermode* xmode, 199 const SkPaint& paint) SK_OVERRIDE; 200 201 virtual void onClipRect(const SkRect&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE; 202 virtual void onClipRRect(const SkRRect&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE; 203 virtual void onClipPath(const SkPath&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE; 204 virtual void onClipRegion(const SkRegion&, SkRegion::Op) SK_OVERRIDE; 205 206 virtual void onDrawPicture(const SkPicture*, const SkMatrix*, const SkPaint*) SK_OVERRIDE; 207 208 public: 209 class NotificationClient { 210 public: 211 virtual ~NotificationClient() {} 212 213 /** 214 * Called before executing one or several draw commands, which means 215 * once per flush when deferred rendering is enabled. 216 */ 217 virtual void prepareForDraw() {} 218 219 /** 220 * Called after a recording a draw command if additional memory 221 * had to be allocated for recording. 222 * @param newAllocatedStorage same value as would be returned by 223 * storageAllocatedForRecording(), for convenience. 224 */ 225 virtual void storageAllocatedForRecordingChanged( 226 size_t newAllocatedStorage) {} 227 228 /** 229 * Called after pending draw commands have been flushed 230 */ 231 virtual void flushedDrawCommands() {} 232 233 /** 234 * Called after pending draw commands have been skipped, meaning 235 * that they were optimized-out because the canvas is cleared 236 * or completely overwritten by the command currently being recorded. 237 */ 238 virtual void skippedPendingDrawCommands() {} 239 }; 240 241 protected: 242 virtual SkCanvas* canvasForDrawIter(); 243 SkDeferredDevice* getDeferredDevice() const; 244 245 private: 246 SkDeferredCanvas(SkDeferredDevice*); 247 248 void recordedDrawCommand(); 249 SkCanvas* drawingCanvas() const; 250 SkCanvas* immediateCanvas() const; 251 bool isFullFrame(const SkRect*, const SkPaint*) const; 252 void validate() const; 253 void init(); 254 255 size_t fBitmapSizeThreshold; 256 bool fDeferredDrawing; 257 258 mutable SkISize fCachedCanvasSize; 259 mutable bool fCachedCanvasSizeDirty; 260 261 friend class SkDeferredCanvasTester; // for unit testing 262 typedef SkCanvas INHERITED; 263 }; 264 265 266 #endif 267
