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 true if the canvas has recorded draw commands that have 93 * not yet been played back. 94 */ 95 bool hasPendingCommands() const; 96 97 /** 98 * Flushes pending draw commands, if any, and returns an image of the 99 * current state of the surface pixels up to this point. Subsequent 100 * changes to the surface (by drawing into its canvas) will not be 101 * reflected in this image. Will return NULL if the deferred canvas 102 * was not constructed from an SkSurface. 103 */ 104 SkImage* newImageSnapshot(); 105 106 /** 107 * Specify the maximum number of bytes to be allocated for the purpose 108 * of recording draw commands to this canvas. The default limit, is 109 * 64MB. 110 * @param maxStorage The maximum number of bytes to be allocated. 111 */ 112 void setMaxRecordingStorage(size_t maxStorage); 113 114 /** 115 * Returns the number of bytes currently allocated for the purpose of 116 * recording draw commands. 117 */ 118 size_t storageAllocatedForRecording() const; 119 120 /** 121 * Attempt to reduce the storage allocated for recording by evicting 122 * cache resources. 123 * @param bytesToFree minimum number of bytes that should be attempted to 124 * be freed. 125 * @return number of bytes actually freed. 126 */ 127 size_t freeMemoryIfPossible(size_t bytesToFree); 128 129 /** 130 * Specifies the maximum size (in bytes) allowed for a given image to be 131 * rendered using the deferred canvas. 132 */ 133 void setBitmapSizeThreshold(size_t sizeThreshold); 134 135 /** 136 * Executes all pending commands without drawing 137 */ 138 void silentFlush(); 139 140 // Overrides of the SkCanvas interface 141 virtual bool isDrawingToLayer() const SK_OVERRIDE; 142 virtual void clear(SkColor) SK_OVERRIDE; 143 virtual void drawPaint(const SkPaint& paint) SK_OVERRIDE; 144 virtual void drawPoints(PointMode mode, size_t count, const SkPoint pts[], 145 const SkPaint& paint) SK_OVERRIDE; 146 virtual void drawOval(const SkRect&, const SkPaint& paint) SK_OVERRIDE; 147 virtual void drawRect(const SkRect& rect, const SkPaint& paint) SK_OVERRIDE; 148 virtual void drawRRect(const SkRRect&, const SkPaint& paint) SK_OVERRIDE; 149 virtual void drawPath(const SkPath& path, const SkPaint& paint) 150 SK_OVERRIDE; 151 virtual void drawBitmap(const SkBitmap& bitmap, SkScalar left, 152 SkScalar top, const SkPaint* paint) 153 SK_OVERRIDE; 154 virtual void drawBitmapRectToRect(const SkBitmap& bitmap, const SkRect* src, 155 const SkRect& dst, const SkPaint* paint, 156 DrawBitmapRectFlags flags) SK_OVERRIDE; 157 158 virtual void drawBitmapMatrix(const SkBitmap& bitmap, const SkMatrix& m, 159 const SkPaint* paint) SK_OVERRIDE; 160 virtual void drawBitmapNine(const SkBitmap& bitmap, const SkIRect& center, 161 const SkRect& dst, const SkPaint* paint) 162 SK_OVERRIDE; 163 virtual void drawSprite(const SkBitmap& bitmap, int left, int top, 164 const SkPaint* paint) SK_OVERRIDE; 165 virtual void drawVertices(VertexMode vmode, int vertexCount, 166 const SkPoint vertices[], const SkPoint texs[], 167 const SkColor colors[], SkXfermode* xmode, 168 const uint16_t indices[], int indexCount, 169 const SkPaint& paint) SK_OVERRIDE; 170 virtual SkDrawFilter* setDrawFilter(SkDrawFilter* filter) SK_OVERRIDE; 171 172 protected: 173 virtual void willSave(SaveFlags) SK_OVERRIDE; 174 virtual SaveLayerStrategy willSaveLayer(const SkRect*, const SkPaint*, SaveFlags) SK_OVERRIDE; 175 virtual void willRestore() SK_OVERRIDE; 176 177 virtual void didConcat(const SkMatrix&) SK_OVERRIDE; 178 virtual void didSetMatrix(const SkMatrix&) SK_OVERRIDE; 179 180 virtual void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&) SK_OVERRIDE; 181 virtual void onDrawText(const void* text, size_t byteLength, SkScalar x, SkScalar y, 182 const SkPaint&) SK_OVERRIDE; 183 virtual void onDrawPosText(const void* text, size_t byteLength, const SkPoint pos[], 184 const SkPaint&) SK_OVERRIDE; 185 virtual void onDrawPosTextH(const void* text, size_t byteLength, const SkScalar xpos[], 186 SkScalar constY, const SkPaint&) SK_OVERRIDE; 187 virtual void onDrawTextOnPath(const void* text, size_t byteLength, const SkPath& path, 188 const SkMatrix* matrix, const SkPaint&) SK_OVERRIDE; 189 190 virtual void onClipRect(const SkRect&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE; 191 virtual void onClipRRect(const SkRRect&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE; 192 virtual void onClipPath(const SkPath&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE; 193 virtual void onClipRegion(const SkRegion&, SkRegion::Op) SK_OVERRIDE; 194 195 virtual void onDrawPicture(const SkPicture* picture) SK_OVERRIDE; 196 197 public: 198 class NotificationClient { 199 public: 200 virtual ~NotificationClient() {} 201 202 /** 203 * Called before executing one or several draw commands, which means 204 * once per flush when deferred rendering is enabled. 205 */ 206 virtual void prepareForDraw() {} 207 208 /** 209 * Called after a recording a draw command if additional memory 210 * had to be allocated for recording. 211 * @param newAllocatedStorage same value as would be returned by 212 * storageAllocatedForRecording(), for convenience. 213 */ 214 virtual void storageAllocatedForRecordingChanged( 215 size_t newAllocatedStorage) {} 216 217 /** 218 * Called after pending draw commands have been flushed 219 */ 220 virtual void flushedDrawCommands() {} 221 222 /** 223 * Called after pending draw commands have been skipped, meaning 224 * that they were optimized-out because the canvas is cleared 225 * or completely overwritten by the command currently being recorded. 226 */ 227 virtual void skippedPendingDrawCommands() {} 228 }; 229 230 protected: 231 virtual SkCanvas* canvasForDrawIter(); 232 SkDeferredDevice* getDeferredDevice() const; 233 234 private: 235 SkDeferredCanvas(SkDeferredDevice*); 236 237 void recordedDrawCommand(); 238 SkCanvas* drawingCanvas() const; 239 SkCanvas* immediateCanvas() const; 240 bool isFullFrame(const SkRect*, const SkPaint*) const; 241 void validate() const; 242 void init(); 243 bool fDeferredDrawing; 244 245 friend class SkDeferredCanvasTester; // for unit testing 246 typedef SkCanvas INHERITED; 247 }; 248 249 250 #endif 251
