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 "include/core/SkRect.h" 12#include "include/core/SkRefCnt.h" 13#include "include/core/SkSamplingOptions.h" 14#include "include/core/SkShader.h" 15#include "include/core/SkTileMode.h" 16#include "include/core/SkTypes.h" 17 18class SkCanvas; 19class SkData; 20struct SkDeserialProcs; 21class SkImage; 22class SkMatrix; 23struct SkSerialProcs; 24class SkStream; 25class SkWStream; 26 27/** \class SkPicture 28 SkPicture records drawing commands made to SkCanvas. The command stream may be 29 played in whole or in part at a later time. 30 31 SkPicture is an abstract class. SkPicture may be generated by SkPictureRecorder 32 or SkDrawable, or from SkPicture previously saved to SkData or SkStream. 33 34 SkPicture may contain any SkCanvas drawing command, as well as one or more 35 SkCanvas matrix or SkCanvas clip. SkPicture has a cull SkRect, which is used as 36 a bounding box hint. To limit SkPicture bounds, use SkCanvas clip when 37 recording or drawing SkPicture. 38*/ 39class SK_API SkPicture : public SkRefCnt { 40public: 41 ~SkPicture() override; 42 43 /** Recreates SkPicture that was serialized into a stream. Returns constructed SkPicture 44 if successful; otherwise, returns nullptr. Fails if data does not permit 45 constructing valid SkPicture. 46 47 procs->fPictureProc permits supplying a custom function to decode SkPicture. 48 If procs->fPictureProc is nullptr, default decoding is used. procs->fPictureCtx 49 may be used to provide user context to procs->fPictureProc; procs->fPictureProc 50 is called with a pointer to data, data byte length, and user context. 51 52 @param stream container for serial data 53 @param procs custom serial data decoders; may be nullptr 54 @return SkPicture constructed from stream data 55 */ 56 static sk_sp<SkPicture> MakeFromStream(SkStream* stream, 57 const SkDeserialProcs* procs = nullptr); 58 59 /** Recreates SkPicture that was serialized into data. Returns constructed SkPicture 60 if successful; otherwise, returns nullptr. Fails if data does not permit 61 constructing valid SkPicture. 62 63 procs->fPictureProc permits supplying a custom function to decode SkPicture. 64 If procs->fPictureProc is nullptr, default decoding is used. procs->fPictureCtx 65 may be used to provide user context to procs->fPictureProc; procs->fPictureProc 66 is called with a pointer to data, data byte length, and user context. 67 68 @param data container for serial data 69 @param procs custom serial data decoders; may be nullptr 70 @return SkPicture constructed from data 71 */ 72 static sk_sp<SkPicture> MakeFromData(const SkData* data, 73 const SkDeserialProcs* procs = nullptr); 74 75 /** 76 77 @param data pointer to serial data 78 @param size size of data 79 @param procs custom serial data decoders; may be nullptr 80 @return SkPicture constructed from data 81 */ 82 static sk_sp<SkPicture> MakeFromData(const void* data, size_t size, 83 const SkDeserialProcs* procs = nullptr); 84 85 /** \class SkPicture::AbortCallback 86 AbortCallback is an abstract class. An implementation of AbortCallback may 87 passed as a parameter to SkPicture::playback, to stop it before all drawing 88 commands have been processed. 89 90 If AbortCallback::abort returns true, SkPicture::playback is interrupted. 91 */ 92 class SK_API AbortCallback { 93 public: 94 /** Has no effect. 95 */ 96 virtual ~AbortCallback() = default; 97 98 /** Stops SkPicture playback when some condition is met. A subclass of 99 AbortCallback provides an override for abort() that can stop SkPicture::playback. 100 101 The part of SkPicture drawn when aborted is undefined. SkPicture instantiations are 102 free to stop drawing at different points during playback. 103 104 If the abort happens inside one or more calls to SkCanvas::save(), stack 105 of SkCanvas matrix and SkCanvas clip values is restored to its state before 106 SkPicture::playback was called. 107 108 @return true to stop playback 109 110 example: https://fiddle.skia.org/c/@Picture_AbortCallback_abort 111 */ 112 virtual bool abort() = 0; 113 114 protected: 115 AbortCallback() = default; 116 AbortCallback(const AbortCallback&) = delete; 117 AbortCallback& operator=(const AbortCallback&) = delete; 118 }; 119 120 /** Replays the drawing commands on the specified canvas. In the case that the 121 commands are recorded, each command in the SkPicture is sent separately to canvas. 122 123 To add a single command to draw SkPicture to recording canvas, call 124 SkCanvas::drawPicture instead. 125 126 @param canvas receiver of drawing commands 127 @param callback allows interruption of playback 128 129 example: https://fiddle.skia.org/c/@Picture_playback 130 */ 131 virtual void playback(SkCanvas* canvas, AbortCallback* callback = nullptr) const = 0; 132 133 /** Returns cull SkRect for this picture, passed in when SkPicture was created. 134 Returned SkRect does not specify clipping SkRect for SkPicture; cull is hint 135 of SkPicture bounds. 136 137 SkPicture is free to discard recorded drawing commands that fall outside 138 cull. 139 140 @return bounds passed when SkPicture was created 141 142 example: https://fiddle.skia.org/c/@Picture_cullRect 143 */ 144 virtual SkRect cullRect() const = 0; 145 146 /** Returns a non-zero value unique among SkPicture in Skia process. 147 148 @return identifier for SkPicture 149 */ 150 uint32_t uniqueID() const { return fUniqueID; } 151 152 /** Returns storage containing SkData describing SkPicture, using optional custom 153 encoders. 154 155 procs->fPictureProc permits supplying a custom function to encode SkPicture. 156 If procs->fPictureProc is nullptr, default encoding is used. procs->fPictureCtx 157 may be used to provide user context to procs->fPictureProc; procs->fPictureProc 158 is called with a pointer to SkPicture and user context. 159 160 @param procs custom serial data encoders; may be nullptr 161 @return storage containing serialized SkPicture 162 163 example: https://fiddle.skia.org/c/@Picture_serialize 164 */ 165 sk_sp<SkData> serialize(const SkSerialProcs* procs = nullptr) const; 166 167 /** Writes picture to stream, using optional custom encoders. 168 169 procs->fPictureProc permits supplying a custom function to encode SkPicture. 170 If procs->fPictureProc is nullptr, default encoding is used. procs->fPictureCtx 171 may be used to provide user context to procs->fPictureProc; procs->fPictureProc 172 is called with a pointer to SkPicture and user context. 173 174 @param stream writable serial data stream 175 @param procs custom serial data encoders; may be nullptr 176 177 example: https://fiddle.skia.org/c/@Picture_serialize_2 178 */ 179 void serialize(SkWStream* stream, const SkSerialProcs* procs = nullptr) const; 180 181 /** Returns a placeholder SkPicture. Result does not draw, and contains only 182 cull SkRect, a hint of its bounds. Result is immutable; it cannot be changed 183 later. Result identifier is unique. 184 185 Returned placeholder can be intercepted during playback to insert other 186 commands into SkCanvas draw stream. 187 188 @param cull placeholder dimensions 189 @return placeholder with unique identifier 190 191 example: https://fiddle.skia.org/c/@Picture_MakePlaceholder 192 */ 193 static sk_sp<SkPicture> MakePlaceholder(SkRect cull); 194 195 /** Returns the approximate number of operations in SkPicture. Returned value 196 may be greater or less than the number of SkCanvas calls 197 recorded: some calls may be recorded as more than one operation, other 198 calls may be optimized away. 199 200 @param nested if true, include the op-counts of nested pictures as well, else 201 just return count the ops in the top-level picture. 202 @return approximate operation count 203 204 example: https://fiddle.skia.org/c/@Picture_approximateOpCount 205 */ 206 virtual int approximateOpCount(bool nested = false) const = 0; 207 208 /** Returns the approximate byte size of SkPicture. Does not include large objects 209 referenced by SkPicture. 210 211 @return approximate size 212 213 example: https://fiddle.skia.org/c/@Picture_approximateBytesUsed 214 */ 215 virtual size_t approximateBytesUsed() const = 0; 216 217 /** Return a new shader that will draw with this picture. 218 * 219 * @param tmx The tiling mode to use when sampling in the x-direction. 220 * @param tmy The tiling mode to use when sampling in the y-direction. 221 * @param mode How to filter the tiles 222 * @param localMatrix Optional matrix used when sampling 223 * @param tile The tile rectangle in picture coordinates: this represents the subset 224 * (or superset) of the picture used when building a tile. It is not 225 * affected by localMatrix and does not imply scaling (only translation 226 * and cropping). If null, the tile rect is considered equal to the picture 227 * bounds. 228 * @return Returns a new shader object. Note: this function never returns null. 229 */ 230 sk_sp<SkShader> makeShader(SkTileMode tmx, SkTileMode tmy, SkFilterMode mode, 231 const SkMatrix* localMatrix, const SkRect* tileRect) const; 232 233 sk_sp<SkShader> makeShader(SkTileMode tmx, SkTileMode tmy, SkFilterMode mode) const { 234 return this->makeShader(tmx, tmy, mode, nullptr, nullptr); 235 } 236 237private: 238 // Allowed subclasses. 239 SkPicture(); 240 friend class SkBigPicture; 241 friend class SkEmptyPicture; 242 friend class SkPicturePriv; 243 template <typename> friend class SkMiniPicture; 244 245 void serialize(SkWStream*, const SkSerialProcs*, class SkRefCntSet* typefaces, 246 bool textBlobsOnly=false) const; 247 static sk_sp<SkPicture> MakeFromStream(SkStream*, const SkDeserialProcs*, 248 class SkTypefacePlayback*); 249 friend class SkPictureData; 250 251 /** Return true if the SkStream/Buffer represents a serialized picture, and 252 fills out SkPictInfo. After this function returns, the data source is not 253 rewound so it will have to be manually reset before passing to 254 MakeFromStream or MakeFromBuffer. Note, MakeFromStream and 255 MakeFromBuffer perform this check internally so these entry points are 256 intended for stand alone tools. 257 If false is returned, SkPictInfo is unmodified. 258 */ 259 static bool StreamIsSKP(SkStream*, struct SkPictInfo*); 260 static bool BufferIsSKP(class SkReadBuffer*, struct SkPictInfo*); 261 friend bool SkPicture_StreamIsSKP(SkStream*, struct SkPictInfo*); 262 263 // Returns NULL if this is not an SkBigPicture. 264 virtual const class SkBigPicture* asSkBigPicture() const { return nullptr; } 265 266 friend struct SkPathCounter; 267 268 static bool IsValidPictInfo(const struct SkPictInfo& info); 269 static sk_sp<SkPicture> Forwardport(const struct SkPictInfo&, 270 const class SkPictureData*, 271 class SkReadBuffer* buffer); 272 273 struct SkPictInfo createHeader() const; 274 class SkPictureData* backport() const; 275 276 uint32_t fUniqueID; 277 mutable std::atomic<bool> fAddedToCache{false}; 278}; 279 280#endif 281