1 /* 2 * Copyright 2007 The Android Open Source Project 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 SkPicture_DEFINED 9 #define SkPicture_DEFINED 10 11 #include "SkImageDecoder.h" 12 #include "SkRefCnt.h" 13 #include "SkTypes.h" 14 15 class GrContext; 16 class SkBigPicture; 17 class SkBitmap; 18 class SkCanvas; 19 class SkPictureData; 20 class SkPixelSerializer; 21 class SkRefCntSet; 22 class SkStream; 23 class SkTypefacePlayback; 24 class SkWStream; 25 struct SkPictInfo; 26 27 /** \class SkPicture 28 29 An SkPicture records drawing commands made to a canvas to be played back at a later time. 30 This base class handles serialization and a few other miscellany. 31 */ 32 class SK_API SkPicture : public SkRefCnt { 33 public: 34 virtual ~SkPicture(); 35 36 /** 37 * Function signature defining a function that sets up an SkBitmap from encoded data. On 38 * success, the SkBitmap should have its Config, width, height, rowBytes and pixelref set. 39 * If the installed pixelref has decoded the data into pixels, then the src buffer need not be 40 * copied. If the pixelref defers the actual decode until its lockPixels() is called, then it 41 * must make a copy of the src buffer. 42 * @param src Encoded data. 43 * @param length Size of the encoded data, in bytes. 44 * @param dst SkBitmap to install the pixel ref on. 45 * @param bool Whether or not a pixel ref was successfully installed. 46 */ 47 typedef bool (*InstallPixelRefProc)(const void* src, size_t length, SkBitmap* dst); 48 49 /** 50 * Recreate a picture that was serialized into a stream. 51 * @param SkStream Serialized picture data. Ownership is unchanged by this call. 52 * @param proc Function pointer for installing pixelrefs on SkBitmaps representing the 53 * encoded bitmap data from the stream. 54 * @return A new SkPicture representing the serialized data, or NULL if the stream is 55 * invalid. 56 */ 57 static SkPicture* CreateFromStream(SkStream*, InstallPixelRefProc proc); 58 59 /** 60 * Recreate a picture that was serialized into a stream. 61 * 62 * Any serialized images in the stream will be passed to 63 * SkImageGenerator::NewFromEncoded. 64 * 65 * @param SkStream Serialized picture data. Ownership is unchanged by this call. 66 * @return A new SkPicture representing the serialized data, or NULL if the stream is 67 * invalid. 68 */ 69 static SkPicture* CreateFromStream(SkStream*); 70 71 /** 72 * Recreate a picture that was serialized into a buffer. If the creation requires bitmap 73 * decoding, the decoder must be set on the SkReadBuffer parameter by calling 74 * SkReadBuffer::setBitmapDecoder() before calling SkPicture::CreateFromBuffer(). 75 * @param SkReadBuffer Serialized picture data. 76 * @return A new SkPicture representing the serialized data, or NULL if the buffer is 77 * invalid. 78 */ 79 static SkPicture* CreateFromBuffer(SkReadBuffer&); 80 81 /** 82 * Subclasses of this can be passed to playback(). During the playback 83 * of the picture, this callback will periodically be invoked. If its 84 * abort() returns true, then picture playback will be interrupted. 85 * 86 * The resulting drawing is undefined, as there is no guarantee how often the 87 * callback will be invoked. If the abort happens inside some level of nested 88 * calls to save(), restore will automatically be called to return the state 89 * to the same level it was before the playback call was made. 90 */ 91 class SK_API AbortCallback { 92 public: 93 AbortCallback() {} 94 virtual ~AbortCallback() {} 95 virtual bool abort() = 0; 96 }; 97 98 /** Replays the drawing commands on the specified canvas. Note that 99 this has the effect of unfurling this picture into the destination 100 canvas. Using the SkCanvas::drawPicture entry point gives the destination 101 canvas the option of just taking a ref. 102 @param canvas the canvas receiving the drawing commands. 103 @param callback a callback that allows interruption of playback 104 */ 105 virtual void playback(SkCanvas*, AbortCallback* = NULL) const = 0; 106 107 /** Return a cull rect for this picture. 108 Ops recorded into this picture that attempt to draw outside the cull might not be drawn. 109 */ 110 virtual SkRect cullRect() const = 0; 111 112 /** Returns a non-zero value unique among all pictures. */ 113 uint32_t uniqueID() const; 114 115 /** 116 * Serialize to a stream. If non NULL, serializer will be used to serialize 117 * bitmaps and images in the picture. 118 */ 119 void serialize(SkWStream*, SkPixelSerializer* = NULL) const; 120 121 /** 122 * Serialize to a buffer. 123 */ 124 void flatten(SkWriteBuffer&) const; 125 126 /** 127 * Returns true if any bitmaps may be produced when this SkPicture 128 * is replayed. 129 */ 130 virtual bool willPlayBackBitmaps() const = 0; 131 132 /** Return the approximate number of operations in this picture. This 133 * number may be greater or less than the number of SkCanvas calls 134 * recorded: some calls may be recorded as more than one operation, or some 135 * calls may be optimized away. 136 */ 137 virtual int approximateOpCount() const = 0; 138 139 /** Return true if this picture contains text. 140 */ 141 virtual bool hasText() const = 0; 142 143 /** Returns the approximate byte size of this picture, not including large ref'd objects. */ 144 virtual size_t approximateBytesUsed() const = 0; 145 146 /** Return true if the SkStream/Buffer represents a serialized picture, and 147 fills out SkPictInfo. After this function returns, the data source is not 148 rewound so it will have to be manually reset before passing to 149 CreateFromStream or CreateFromBuffer. Note, CreateFromStream and 150 CreateFromBuffer perform this check internally so these entry points are 151 intended for stand alone tools. 152 If false is returned, SkPictInfo is unmodified. 153 */ 154 static bool InternalOnly_StreamIsSKP(SkStream*, SkPictInfo*); 155 static bool InternalOnly_BufferIsSKP(SkReadBuffer*, SkPictInfo*); 156 157 /** Return true if the picture is suitable for rendering on the GPU. */ 158 bool suitableForGpuRasterization(GrContext*, const char** whyNot = NULL) const; 159 160 // Sent via SkMessageBus from destructor. 161 struct DeletionMessage { int32_t fUniqueID; }; // TODO: -> uint32_t? 162 163 // Returns NULL if this is not an SkBigPicture. 164 virtual const SkBigPicture* asSkBigPicture() const { return NULL; } 165 166 // Global setting to enable or disable security precautions for serialization. 167 static void SetPictureIOSecurityPrecautionsEnabled_Dangerous(bool set); 168 static bool PictureIOSecurityPrecautionsEnabled(); 169 170 private: 171 // Subclass whitelist. 172 SkPicture(); 173 friend class SkBigPicture; 174 friend class SkEmptyPicture; 175 template <typename> friend class SkMiniPicture; 176 177 void serialize(SkWStream*, SkPixelSerializer*, SkRefCntSet* typefaces) const; 178 static SkPicture* CreateFromStream(SkStream*, 179 InstallPixelRefProc proc, 180 SkTypefacePlayback*); 181 friend class SkPictureData; 182 183 virtual int numSlowPaths() const = 0; 184 friend struct SkPathCounter; 185 186 // V35: Store SkRect (rather then width & height) in header 187 // V36: Remove (obsolete) alphatype from SkColorTable 188 // V37: Added shadow only option to SkDropShadowImageFilter (last version to record CLEAR) 189 // V38: Added PictureResolution option to SkPictureImageFilter 190 // V39: Added FilterLevel option to SkPictureImageFilter 191 // V40: Remove UniqueID serialization from SkImageFilter. 192 // V41: Added serialization of SkBitmapSource's filterQuality parameter 193 // V42: Added a bool to SkPictureShader serialization to indicate did-we-serialize-a-picture? 194 // V43: Added DRAW_IMAGE and DRAW_IMAGE_RECT opt codes to serialized data 195 196 // Only SKPs within the min/current picture version range (inclusive) can be read. 197 static const uint32_t MIN_PICTURE_VERSION = 35; // Produced by Chrome M39. 198 static const uint32_t CURRENT_PICTURE_VERSION = 43; 199 200 static_assert(MIN_PICTURE_VERSION <= 41, 201 "Remove kFontFileName and related code from SkFontDescriptor.cpp."); 202 203 static_assert(MIN_PICTURE_VERSION <= 42, 204 "Remove COMMENT API handlers from SkPicturePlayback.cpp"); 205 206 static_assert(MIN_PICTURE_VERSION <= 43, 207 "Remove SkBitmapSourceDeserializer."); 208 209 static bool IsValidPictInfo(const SkPictInfo& info); 210 static SkPicture* Forwardport(const SkPictInfo&, const SkPictureData*); 211 212 SkPictInfo createHeader() const; 213 SkPictureData* backport() const; 214 215 mutable uint32_t fUniqueID; 216 }; 217 218 #endif 219
