1 /* 2 * Copyright 2006 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 SkCanvas_DEFINED 9 #define SkCanvas_DEFINED 10 11 #include "SkTypes.h" 12 #include "SkBitmap.h" 13 #include "SkDeque.h" 14 #include "SkClipStack.h" 15 #include "SkPaint.h" 16 #include "SkRefCnt.h" 17 #include "SkPath.h" 18 #include "SkRegion.h" 19 #include "SkSurfaceProps.h" 20 #include "SkXfermode.h" 21 22 #ifdef SK_SUPPORT_LEGACY_DRAWTEXT_VIRTUAL 23 #define SK_LEGACY_DRAWTEXT_VIRTUAL virtual 24 #else 25 #define SK_LEGACY_DRAWTEXT_VIRTUAL 26 #endif 27 28 class SkCanvasClipVisitor; 29 class SkBaseDevice; 30 class SkDraw; 31 class SkDrawFilter; 32 class SkImage; 33 class SkMetaData; 34 class SkPicture; 35 class SkRRect; 36 class SkSurface; 37 class SkSurface_Base; 38 class SkTextBlob; 39 class GrContext; 40 class GrRenderTarget; 41 42 class SkCanvasState; 43 44 namespace SkCanvasStateUtils { 45 SK_API SkCanvasState* CaptureCanvasState(SkCanvas*); 46 } 47 48 /** \class SkCanvas 49 50 A Canvas encapsulates all of the state about drawing into a device (bitmap). 51 This includes a reference to the device itself, and a stack of matrix/clip 52 values. For any given draw call (e.g. drawRect), the geometry of the object 53 being drawn is transformed by the concatenation of all the matrices in the 54 stack. The transformed geometry is clipped by the intersection of all of 55 the clips in the stack. 56 57 While the Canvas holds the state of the drawing device, the state (style) 58 of the object being drawn is held by the Paint, which is provided as a 59 parameter to each of the draw() methods. The Paint holds attributes such as 60 color, typeface, textSize, strokeWidth, shader (e.g. gradients, patterns), 61 etc. 62 */ 63 class SK_API SkCanvas : public SkRefCnt { 64 public: 65 SK_DECLARE_INST_COUNT(SkCanvas) 66 67 /** 68 * Attempt to allocate an offscreen raster canvas, matching the ImageInfo. 69 * On success, return a new canvas that will draw into that offscreen. 70 * 71 * The caller can access the pixels after drawing into this canvas by 72 * calling readPixels() or peekPixels(). 73 * 74 * If the requested ImageInfo is opaque (either the colortype is 75 * intrinsically opaque like RGB_565, or the info's alphatype is kOpaque) 76 * then the pixel memory may be uninitialized. Otherwise, the pixel memory 77 * will be initialized to 0, which is interpreted as transparent. 78 * 79 * On failure, return NULL. This can fail for several reasons: 80 * 1. the memory allocation failed (e.g. request is too large) 81 * 2. invalid ImageInfo (e.g. negative dimensions) 82 * 3. unsupported ImageInfo for a canvas 83 * - kUnknown_SkColorType, kIndex_8_SkColorType 84 * - kIgnore_SkAlphaType 85 * - this list is not complete, so others may also be unsupported 86 * 87 * Note: it is valid to request a supported ImageInfo, but with zero 88 * dimensions. 89 */ 90 static SkCanvas* NewRaster(const SkImageInfo&); 91 92 static SkCanvas* NewRasterN32(int width, int height) { 93 return NewRaster(SkImageInfo::MakeN32Premul(width, height)); 94 } 95 96 /** 97 * Attempt to allocate raster canvas, matching the ImageInfo, that will draw directly into the 98 * specified pixels. To access the pixels after drawing to them, the caller should call 99 * flush() or call peekPixels(...). 100 * 101 * On failure, return NULL. This can fail for several reasons: 102 * 1. invalid ImageInfo (e.g. negative dimensions) 103 * 2. unsupported ImageInfo for a canvas 104 * - kUnknown_SkColorType, kIndex_8_SkColorType 105 * - kIgnore_SkAlphaType 106 * - this list is not complete, so others may also be unsupported 107 * 108 * Note: it is valid to request a supported ImageInfo, but with zero 109 * dimensions. 110 */ 111 static SkCanvas* NewRasterDirect(const SkImageInfo&, void*, size_t); 112 113 static SkCanvas* NewRasterDirectN32(int width, int height, SkPMColor* pixels, size_t rowBytes) { 114 return NewRasterDirect(SkImageInfo::MakeN32Premul(width, height), pixels, rowBytes); 115 } 116 117 /** 118 * Creates an empty canvas with no backing device/pixels, and zero 119 * dimensions. 120 */ 121 SkCanvas(); 122 123 /** 124 * Creates a canvas of the specified dimensions, but explicitly not backed 125 * by any device/pixels. Typically this use used by subclasses who handle 126 * the draw calls in some other way. 127 */ 128 SkCanvas(int width, int height); 129 130 /** Construct a canvas with the specified device to draw into. 131 132 @param device Specifies a device for the canvas to draw into. 133 */ 134 explicit SkCanvas(SkBaseDevice* device); 135 136 /** Construct a canvas with the specified bitmap to draw into. 137 @param bitmap Specifies a bitmap for the canvas to draw into. Its 138 structure are copied to the canvas. 139 */ 140 explicit SkCanvas(const SkBitmap& bitmap); 141 virtual ~SkCanvas(); 142 143 SkMetaData& getMetaData(); 144 145 /** 146 * Return ImageInfo for this canvas. If the canvas is not backed by pixels 147 * (cpu or gpu), then the info's ColorType will be kUnknown_SkColorType. 148 */ 149 SkImageInfo imageInfo() const; 150 151 /////////////////////////////////////////////////////////////////////////// 152 153 /** 154 * Trigger the immediate execution of all pending draw operations. 155 */ 156 void flush(); 157 158 /** 159 * Gets the size of the base or root layer in global canvas coordinates. The 160 * origin of the base layer is always (0,0). The current drawable area may be 161 * smaller (due to clipping or saveLayer). 162 */ 163 SkISize getBaseLayerSize() const; 164 165 /** 166 * DEPRECATED: call getBaseLayerSize 167 */ 168 SkISize getDeviceSize() const { return this->getBaseLayerSize(); } 169 170 /** 171 * DEPRECATED. 172 * Return the canvas' device object, which may be null. The device holds 173 * the bitmap of the pixels that the canvas draws into. The reference count 174 * of the returned device is not changed by this call. 175 */ 176 #ifndef SK_SUPPORT_LEGACY_GETDEVICE 177 protected: // Can we make this private? 178 #endif 179 SkBaseDevice* getDevice() const; 180 public: 181 182 /** 183 * saveLayer() can create another device (which is later drawn onto 184 * the previous device). getTopDevice() returns the top-most device current 185 * installed. Note that this can change on other calls like save/restore, 186 * so do not access this device after subsequent canvas calls. 187 * The reference count of the device is not changed. 188 * 189 * @param updateMatrixClip If this is true, then before the device is 190 * returned, we ensure that its has been notified about the current 191 * matrix and clip. Note: this happens automatically when the device 192 * is drawn to, but is optional here, as there is a small perf hit 193 * sometimes. 194 */ 195 #ifndef SK_SUPPORT_LEGACY_GETTOPDEVICE 196 private: 197 #endif 198 SkBaseDevice* getTopDevice(bool updateMatrixClip = false) const; 199 public: 200 201 /** 202 * Create a new surface matching the specified info, one that attempts to 203 * be maximally compatible when used with this canvas. If there is no matching Surface type, 204 * NULL is returned. 205 * 206 * If surfaceprops is specified, those are passed to the new surface, otherwise the new surface 207 * inherits the properties of the surface that owns this canvas. If this canvas has no parent 208 * surface, then the new surface is created with default properties. 209 */ 210 SkSurface* newSurface(const SkImageInfo&, const SkSurfaceProps* = NULL); 211 212 /** 213 * Return the GPU context of the device that is associated with the canvas. 214 * For a canvas with non-GPU device, NULL is returned. 215 */ 216 GrContext* getGrContext(); 217 218 /////////////////////////////////////////////////////////////////////////// 219 220 /** 221 * If the canvas has writable pixels in its top layer (and is not recording to a picture 222 * or other non-raster target) and has direct access to its pixels (i.e. they are in 223 * local RAM) return the address of those pixels, and if not null, 224 * return the ImageInfo, rowBytes and origin. The returned address is only valid 225 * while the canvas object is in scope and unchanged. Any API calls made on 226 * canvas (or its parent surface if any) will invalidate the 227 * returned address (and associated information). 228 * 229 * On failure, returns NULL and the info, rowBytes, and origin parameters are ignored. 230 */ 231 void* accessTopLayerPixels(SkImageInfo* info, size_t* rowBytes, SkIPoint* origin = NULL); 232 233 /** 234 * If the canvas has readable pixels in its base layer (and is not recording to a picture 235 * or other non-raster target) and has direct access to its pixels (i.e. they are in 236 * local RAM) return the const-address of those pixels, and if not null, 237 * return the ImageInfo and rowBytes. The returned address is only valid 238 * while the canvas object is in scope and unchanged. Any API calls made on 239 * canvas (or its parent surface if any) will invalidate the 240 * returned address (and associated information). 241 * 242 * On failure, returns NULL and the info and rowBytes parameters are 243 * ignored. 244 */ 245 const void* peekPixels(SkImageInfo* info, size_t* rowBytes); 246 247 /** 248 * Copy the pixels from the base-layer into the specified buffer (pixels + rowBytes), 249 * converting them into the requested format (SkImageInfo). The base-layer pixels are read 250 * starting at the specified (srcX,srcY) location in the coordinate system of the base-layer. 251 * 252 * The specified ImageInfo and (srcX,srcY) offset specifies a source rectangle 253 * 254 * srcR.setXYWH(srcX, srcY, dstInfo.width(), dstInfo.height()); 255 * 256 * srcR is intersected with the bounds of the base-layer. If this intersection is not empty, 257 * then we have two sets of pixels (of equal size). Replace the dst pixels with the 258 * corresponding src pixels, performing any colortype/alphatype transformations needed 259 * (in the case where the src and dst have different colortypes or alphatypes). 260 * 261 * This call can fail, returning false, for several reasons: 262 * - If srcR does not intersect the base-layer bounds. 263 * - If the requested colortype/alphatype cannot be converted from the base-layer's types. 264 * - If this canvas is not backed by pixels (e.g. picture or PDF) 265 */ 266 bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes, 267 int srcX, int srcY); 268 269 /** 270 * Helper for calling readPixels(info, ...). This call will check if bitmap has been allocated. 271 * If not, it will attempt to call allocPixels(). If this fails, it will return false. If not, 272 * it calls through to readPixels(info, ...) and returns its result. 273 */ 274 bool readPixels(SkBitmap* bitmap, int srcX, int srcY); 275 276 /** 277 * Helper for allocating pixels and then calling readPixels(info, ...). The bitmap is resized 278 * to the intersection of srcRect and the base-layer bounds. On success, pixels will be 279 * allocated in bitmap and true returned. On failure, false is returned and bitmap will be 280 * set to empty. 281 */ 282 bool readPixels(const SkIRect& srcRect, SkBitmap* bitmap); 283 284 /** 285 * This method affects the pixels in the base-layer, and operates in pixel coordinates, 286 * ignoring the matrix and clip. 287 * 288 * The specified ImageInfo and (x,y) offset specifies a rectangle: target. 289 * 290 * target.setXYWH(x, y, info.width(), info.height()); 291 * 292 * Target is intersected with the bounds of the base-layer. If this intersection is not empty, 293 * then we have two sets of pixels (of equal size), the "src" specified by info+pixels+rowBytes 294 * and the "dst" by the canvas' backend. Replace the dst pixels with the corresponding src 295 * pixels, performing any colortype/alphatype transformations needed (in the case where the 296 * src and dst have different colortypes or alphatypes). 297 * 298 * This call can fail, returning false, for several reasons: 299 * - If the src colortype/alphatype cannot be converted to the canvas' types 300 * - If this canvas is not backed by pixels (e.g. picture or PDF) 301 */ 302 bool writePixels(const SkImageInfo&, const void* pixels, size_t rowBytes, int x, int y); 303 304 /** 305 * Helper for calling writePixels(info, ...) by passing its pixels and rowbytes. If the bitmap 306 * is just wrapping a texture, returns false and does nothing. 307 */ 308 bool writePixels(const SkBitmap& bitmap, int x, int y); 309 310 /////////////////////////////////////////////////////////////////////////// 311 312 enum SaveFlags { 313 /** save the matrix state, restoring it on restore() */ 314 // [deprecated] kMatrix_SaveFlag = 0x01, 315 kMatrix_SaveFlag = 0x01, 316 /** save the clip state, restoring it on restore() */ 317 // [deprecated] kClip_SaveFlag = 0x02, 318 kClip_SaveFlag = 0x02, 319 /** the layer needs to support per-pixel alpha */ 320 kHasAlphaLayer_SaveFlag = 0x04, 321 /** the layer needs to support 8-bits per color component */ 322 kFullColorLayer_SaveFlag = 0x08, 323 /** 324 * the layer should clip against the bounds argument 325 * 326 * if SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG is undefined, this is treated as always on. 327 */ 328 kClipToLayer_SaveFlag = 0x10, 329 330 // helper masks for common choices 331 // [deprecated] kMatrixClip_SaveFlag = 0x03, 332 kMatrixClip_SaveFlag = 0x03, 333 #ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG 334 kARGB_NoClipLayer_SaveFlag = 0x0F, 335 #endif 336 kARGB_ClipLayer_SaveFlag = 0x1F 337 }; 338 339 /** This call saves the current matrix, clip, and drawFilter, and pushes a 340 copy onto a private stack. Subsequent calls to translate, scale, 341 rotate, skew, concat or clipRect, clipPath, and setDrawFilter all 342 operate on this copy. 343 When the balancing call to restore() is made, the previous matrix, clip, 344 and drawFilter are restored. 345 346 @return The value to pass to restoreToCount() to balance this save() 347 */ 348 int save(); 349 350 /** This behaves the same as save(), but in addition it allocates an 351 offscreen bitmap. All drawing calls are directed there, and only when 352 the balancing call to restore() is made is that offscreen transfered to 353 the canvas (or the previous layer). 354 @param bounds (may be null) This rect, if non-null, is used as a hint to 355 limit the size of the offscreen, and thus drawing may be 356 clipped to it, though that clipping is not guaranteed to 357 happen. If exact clipping is desired, use clipRect(). 358 @param paint (may be null) This is copied, and is applied to the 359 offscreen when restore() is called 360 @return The value to pass to restoreToCount() to balance this save() 361 */ 362 int saveLayer(const SkRect* bounds, const SkPaint* paint); 363 364 /** DEPRECATED - use saveLayer(const SkRect*, const SkPaint*) instead. 365 366 This behaves the same as saveLayer(const SkRect*, const SkPaint*), 367 but it allows fine-grained control of which state bits to be saved 368 (and subsequently restored). 369 370 @param bounds (may be null) This rect, if non-null, is used as a hint to 371 limit the size of the offscreen, and thus drawing may be 372 clipped to it, though that clipping is not guaranteed to 373 happen. If exact clipping is desired, use clipRect(). 374 @param paint (may be null) This is copied, and is applied to the 375 offscreen when restore() is called 376 @param flags LayerFlags 377 @return The value to pass to restoreToCount() to balance this save() 378 */ 379 SK_ATTR_EXTERNALLY_DEPRECATED("SaveFlags use is deprecated") 380 int saveLayer(const SkRect* bounds, const SkPaint* paint, SaveFlags flags); 381 382 /** This behaves the same as save(), but in addition it allocates an 383 offscreen bitmap. All drawing calls are directed there, and only when 384 the balancing call to restore() is made is that offscreen transfered to 385 the canvas (or the previous layer). 386 @param bounds (may be null) This rect, if non-null, is used as a hint to 387 limit the size of the offscreen, and thus drawing may be 388 clipped to it, though that clipping is not guaranteed to 389 happen. If exact clipping is desired, use clipRect(). 390 @param alpha This is applied to the offscreen when restore() is called. 391 @return The value to pass to restoreToCount() to balance this save() 392 */ 393 int saveLayerAlpha(const SkRect* bounds, U8CPU alpha); 394 395 /** DEPRECATED - use saveLayerAlpha(const SkRect*, U8CPU) instead. 396 397 This behaves the same as saveLayerAlpha(const SkRect*, U8CPU), 398 but it allows fine-grained control of which state bits to be saved 399 (and subsequently restored). 400 401 @param bounds (may be null) This rect, if non-null, is used as a hint to 402 limit the size of the offscreen, and thus drawing may be 403 clipped to it, though that clipping is not guaranteed to 404 happen. If exact clipping is desired, use clipRect(). 405 @param alpha This is applied to the offscreen when restore() is called. 406 @param flags LayerFlags 407 @return The value to pass to restoreToCount() to balance this save() 408 */ 409 SK_ATTR_EXTERNALLY_DEPRECATED("SaveFlags use is deprecated") 410 int saveLayerAlpha(const SkRect* bounds, U8CPU alpha, SaveFlags flags); 411 412 /** This call balances a previous call to save(), and is used to remove all 413 modifications to the matrix/clip/drawFilter state since the last save 414 call. 415 It is an error to call restore() more times than save() was called. 416 */ 417 void restore(); 418 419 /** Returns the number of matrix/clip states on the SkCanvas' private stack. 420 This will equal # save() calls - # restore() calls + 1. The save count on 421 a new canvas is 1. 422 */ 423 int getSaveCount() const; 424 425 /** Efficient way to pop any calls to save() that happened after the save 426 count reached saveCount. It is an error for saveCount to be greater than 427 getSaveCount(). To pop all the way back to the initial matrix/clip context 428 pass saveCount == 1. 429 @param saveCount The number of save() levels to restore from 430 */ 431 void restoreToCount(int saveCount); 432 433 /** Returns true if drawing is currently going to a layer (from saveLayer) 434 * rather than to the root device. 435 */ 436 virtual bool isDrawingToLayer() const; 437 438 /** Preconcat the current matrix with the specified translation 439 @param dx The distance to translate in X 440 @param dy The distance to translate in Y 441 */ 442 void translate(SkScalar dx, SkScalar dy); 443 444 /** Preconcat the current matrix with the specified scale. 445 @param sx The amount to scale in X 446 @param sy The amount to scale in Y 447 */ 448 void scale(SkScalar sx, SkScalar sy); 449 450 /** Preconcat the current matrix with the specified rotation. 451 @param degrees The amount to rotate, in degrees 452 */ 453 void rotate(SkScalar degrees); 454 455 /** Preconcat the current matrix with the specified skew. 456 @param sx The amount to skew in X 457 @param sy The amount to skew in Y 458 */ 459 void skew(SkScalar sx, SkScalar sy); 460 461 /** Preconcat the current matrix with the specified matrix. 462 @param matrix The matrix to preconcatenate with the current matrix 463 */ 464 void concat(const SkMatrix& matrix); 465 466 /** Replace the current matrix with a copy of the specified matrix. 467 @param matrix The matrix that will be copied into the current matrix. 468 */ 469 void setMatrix(const SkMatrix& matrix); 470 471 /** Helper for setMatrix(identity). Sets the current matrix to identity. 472 */ 473 void resetMatrix(); 474 475 /** 476 * Modify the current clip with the specified rectangle. 477 * @param rect The rect to combine with the current clip 478 * @param op The region op to apply to the current clip 479 * @param doAntiAlias true if the clip should be antialiased 480 */ 481 void clipRect(const SkRect& rect, 482 SkRegion::Op op = SkRegion::kIntersect_Op, 483 bool doAntiAlias = false); 484 485 /** 486 * Modify the current clip with the specified SkRRect. 487 * @param rrect The rrect to combine with the current clip 488 * @param op The region op to apply to the current clip 489 * @param doAntiAlias true if the clip should be antialiased 490 */ 491 void clipRRect(const SkRRect& rrect, 492 SkRegion::Op op = SkRegion::kIntersect_Op, 493 bool doAntiAlias = false); 494 495 /** 496 * Modify the current clip with the specified path. 497 * @param path The path to combine with the current clip 498 * @param op The region op to apply to the current clip 499 * @param doAntiAlias true if the clip should be antialiased 500 */ 501 void clipPath(const SkPath& path, 502 SkRegion::Op op = SkRegion::kIntersect_Op, 503 bool doAntiAlias = false); 504 505 /** EXPERIMENTAL -- only used for testing 506 Set to false to force clips to be hard, even if doAntiAlias=true is 507 passed to clipRect or clipPath. 508 */ 509 void setAllowSoftClip(bool allow) { 510 fAllowSoftClip = allow; 511 } 512 513 /** EXPERIMENTAL -- only used for testing 514 Set to simplify clip stack using path ops. 515 */ 516 void setAllowSimplifyClip(bool allow) { 517 fAllowSimplifyClip = allow; 518 } 519 520 /** Modify the current clip with the specified region. Note that unlike 521 clipRect() and clipPath() which transform their arguments by the current 522 matrix, clipRegion() assumes its argument is already in device 523 coordinates, and so no transformation is performed. 524 @param deviceRgn The region to apply to the current clip 525 @param op The region op to apply to the current clip 526 */ 527 void clipRegion(const SkRegion& deviceRgn, 528 SkRegion::Op op = SkRegion::kIntersect_Op); 529 530 /** Helper for clipRegion(rgn, kReplace_Op). Sets the current clip to the 531 specified region. This does not intersect or in any other way account 532 for the existing clip region. 533 @param deviceRgn The region to copy into the current clip. 534 */ 535 void setClipRegion(const SkRegion& deviceRgn) { 536 this->clipRegion(deviceRgn, SkRegion::kReplace_Op); 537 } 538 539 /** Return true if the specified rectangle, after being transformed by the 540 current matrix, would lie completely outside of the current clip. Call 541 this to check if an area you intend to draw into is clipped out (and 542 therefore you can skip making the draw calls). 543 @param rect the rect to compare with the current clip 544 @return true if the rect (transformed by the canvas' matrix) does not 545 intersect with the canvas' clip 546 */ 547 bool quickReject(const SkRect& rect) const; 548 549 /** Return true if the specified path, after being transformed by the 550 current matrix, would lie completely outside of the current clip. Call 551 this to check if an area you intend to draw into is clipped out (and 552 therefore you can skip making the draw calls). Note, for speed it may 553 return false even if the path itself might not intersect the clip 554 (i.e. the bounds of the path intersects, but the path does not). 555 @param path The path to compare with the current clip 556 @return true if the path (transformed by the canvas' matrix) does not 557 intersect with the canvas' clip 558 */ 559 bool quickReject(const SkPath& path) const; 560 561 /** Return true if the horizontal band specified by top and bottom is 562 completely clipped out. This is a conservative calculation, meaning 563 that it is possible that if the method returns false, the band may still 564 in fact be clipped out, but the converse is not true. If this method 565 returns true, then the band is guaranteed to be clipped out. 566 @param top The top of the horizontal band to compare with the clip 567 @param bottom The bottom of the horizontal and to compare with the clip 568 @return true if the horizontal band is completely clipped out (i.e. does 569 not intersect the current clip) 570 */ 571 bool quickRejectY(SkScalar top, SkScalar bottom) const { 572 SkASSERT(top <= bottom); 573 574 #ifndef SK_WILL_NEVER_DRAW_PERSPECTIVE_TEXT 575 // TODO: add a hasPerspective method similar to getLocalClipBounds. This 576 // would cache the SkMatrix::hasPerspective result. Alternatively, have 577 // the MC stack just set a hasPerspective boolean as it is updated. 578 if (this->getTotalMatrix().hasPerspective()) { 579 // TODO: consider implementing some half-plane test between the 580 // two Y planes and the device-bounds (i.e., project the top and 581 // bottom Y planes and then determine if the clip bounds is completely 582 // outside either one). 583 return false; 584 } 585 #endif 586 587 const SkRect& clipR = this->getLocalClipBounds(); 588 // In the case where the clip is empty and we are provided with a 589 // negative top and positive bottom parameter then this test will return 590 // false even though it will be clipped. We have chosen to exclude that 591 // check as it is rare and would result double the comparisons. 592 return top >= clipR.fBottom || bottom <= clipR.fTop; 593 } 594 595 /** Return the bounds of the current clip (in local coordinates) in the 596 bounds parameter, and return true if it is non-empty. This can be useful 597 in a way similar to quickReject, in that it tells you that drawing 598 outside of these bounds will be clipped out. 599 */ 600 virtual bool getClipBounds(SkRect* bounds) const; 601 602 /** Return the bounds of the current clip, in device coordinates; returns 603 true if non-empty. Maybe faster than getting the clip explicitly and 604 then taking its bounds. 605 */ 606 virtual bool getClipDeviceBounds(SkIRect* bounds) const; 607 608 609 /** Fill the entire canvas' bitmap (restricted to the current clip) with the 610 specified ARGB color, using the specified mode. 611 @param a the alpha component (0..255) of the color to fill the canvas 612 @param r the red component (0..255) of the color to fill the canvas 613 @param g the green component (0..255) of the color to fill the canvas 614 @param b the blue component (0..255) of the color to fill the canvas 615 @param mode the mode to apply the color in (defaults to SrcOver) 616 */ 617 void drawARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b, 618 SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode); 619 620 /** Fill the entire canvas' bitmap (restricted to the current clip) with the 621 specified color and mode. 622 @param color the color to draw with 623 @param mode the mode to apply the color in (defaults to SrcOver) 624 */ 625 void drawColor(SkColor color, 626 SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode); 627 628 /** 629 * This erases the entire drawing surface to the specified color, 630 * irrespective of the clip. It does not blend with the previous pixels, 631 * but always overwrites them. 632 * 633 * It is roughly equivalent to the following: 634 * canvas.save(); 635 * canvas.clipRect(hugeRect, kReplace_Op); 636 * paint.setColor(color); 637 * paint.setXfermodeMode(kSrc_Mode); 638 * canvas.drawPaint(paint); 639 * canvas.restore(); 640 * though it is almost always much more efficient. 641 */ 642 virtual void clear(SkColor); 643 644 /** 645 * This makes the contents of the canvas undefined. Subsequent calls that 646 * require reading the canvas contents will produce undefined results. Examples 647 * include blending and readPixels. The actual implementation is backend- 648 * dependent and one legal implementation is to do nothing. Like clear(), this 649 * ignores the clip. 650 * 651 * This function should only be called if the caller intends to subsequently 652 * draw to the canvas. The canvas may do real work at discard() time in order 653 * to optimize performance on subsequent draws. Thus, if you call this and then 654 * never draw to the canvas subsequently you may pay a perfomance penalty. 655 */ 656 void discard() { this->onDiscard(); } 657 658 /** 659 * Fill the entire canvas' bitmap (restricted to the current clip) with the 660 * specified paint. 661 * @param paint The paint used to fill the canvas 662 */ 663 virtual void drawPaint(const SkPaint& paint); 664 665 enum PointMode { 666 /** drawPoints draws each point separately */ 667 kPoints_PointMode, 668 /** drawPoints draws each pair of points as a line segment */ 669 kLines_PointMode, 670 /** drawPoints draws the array of points as a polygon */ 671 kPolygon_PointMode 672 }; 673 674 /** Draw a series of points, interpreted based on the PointMode mode. For 675 all modes, the count parameter is interpreted as the total number of 676 points. For kLine mode, count/2 line segments are drawn. 677 For kPoint mode, each point is drawn centered at its coordinate, and its 678 size is specified by the paint's stroke-width. It draws as a square, 679 unless the paint's cap-type is round, in which the points are drawn as 680 circles. 681 For kLine mode, each pair of points is drawn as a line segment, 682 respecting the paint's settings for cap/join/width. 683 For kPolygon mode, the entire array is drawn as a series of connected 684 line segments. 685 Note that, while similar, kLine and kPolygon modes draw slightly 686 differently than the equivalent path built with a series of moveto, 687 lineto calls, in that the path will draw all of its contours at once, 688 with no interactions if contours intersect each other (think XOR 689 xfermode). drawPoints always draws each element one at a time. 690 @param mode PointMode specifying how to draw the array of points. 691 @param count The number of points in the array 692 @param pts Array of points to draw 693 @param paint The paint used to draw the points 694 */ 695 virtual void drawPoints(PointMode mode, size_t count, const SkPoint pts[], 696 const SkPaint& paint); 697 698 /** Helper method for drawing a single point. See drawPoints() for a more 699 details. 700 */ 701 void drawPoint(SkScalar x, SkScalar y, const SkPaint& paint); 702 703 /** Draws a single pixel in the specified color. 704 @param x The X coordinate of which pixel to draw 705 @param y The Y coordiante of which pixel to draw 706 @param color The color to draw 707 */ 708 void drawPoint(SkScalar x, SkScalar y, SkColor color); 709 710 /** Draw a line segment with the specified start and stop x,y coordinates, 711 using the specified paint. NOTE: since a line is always "framed", the 712 paint's Style is ignored. 713 @param x0 The x-coordinate of the start point of the line 714 @param y0 The y-coordinate of the start point of the line 715 @param x1 The x-coordinate of the end point of the line 716 @param y1 The y-coordinate of the end point of the line 717 @param paint The paint used to draw the line 718 */ 719 void drawLine(SkScalar x0, SkScalar y0, SkScalar x1, SkScalar y1, 720 const SkPaint& paint); 721 722 /** Draw the specified rectangle using the specified paint. The rectangle 723 will be filled or stroked based on the Style in the paint. 724 @param rect The rect to be drawn 725 @param paint The paint used to draw the rect 726 */ 727 virtual void drawRect(const SkRect& rect, const SkPaint& paint); 728 729 /** Draw the specified rectangle using the specified paint. The rectangle 730 will be filled or framed based on the Style in the paint. 731 @param rect The rect to be drawn 732 @param paint The paint used to draw the rect 733 */ 734 void drawIRect(const SkIRect& rect, const SkPaint& paint) { 735 SkRect r; 736 r.set(rect); // promotes the ints to scalars 737 this->drawRect(r, paint); 738 } 739 740 /** Draw the specified rectangle using the specified paint. The rectangle 741 will be filled or framed based on the Style in the paint. 742 @param left The left side of the rectangle to be drawn 743 @param top The top side of the rectangle to be drawn 744 @param right The right side of the rectangle to be drawn 745 @param bottom The bottom side of the rectangle to be drawn 746 @param paint The paint used to draw the rect 747 */ 748 void drawRectCoords(SkScalar left, SkScalar top, SkScalar right, 749 SkScalar bottom, const SkPaint& paint); 750 751 /** Draw the specified oval using the specified paint. The oval will be 752 filled or framed based on the Style in the paint. 753 @param oval The rectangle bounds of the oval to be drawn 754 @param paint The paint used to draw the oval 755 */ 756 virtual void drawOval(const SkRect& oval, const SkPaint&); 757 758 /** 759 * Draw the specified RRect using the specified paint The rrect will be filled or stroked 760 * based on the Style in the paint. 761 * 762 * @param rrect The round-rect to draw 763 * @param paint The paint used to draw the round-rect 764 */ 765 virtual void drawRRect(const SkRRect& rrect, const SkPaint& paint); 766 767 /** 768 * Draw the annulus formed by the outer and inner rrects. The results 769 * are undefined if the outer does not contain the inner. 770 */ 771 void drawDRRect(const SkRRect& outer, const SkRRect& inner, const SkPaint&); 772 773 /** Draw the specified circle using the specified paint. If radius is <= 0, 774 then nothing will be drawn. The circle will be filled 775 or framed based on the Style in the paint. 776 @param cx The x-coordinate of the center of the cirle to be drawn 777 @param cy The y-coordinate of the center of the cirle to be drawn 778 @param radius The radius of the cirle to be drawn 779 @param paint The paint used to draw the circle 780 */ 781 void drawCircle(SkScalar cx, SkScalar cy, SkScalar radius, 782 const SkPaint& paint); 783 784 /** Draw the specified arc, which will be scaled to fit inside the 785 specified oval. If the sweep angle is >= 360, then the oval is drawn 786 completely. Note that this differs slightly from SkPath::arcTo, which 787 treats the sweep angle mod 360. 788 @param oval The bounds of oval used to define the shape of the arc 789 @param startAngle Starting angle (in degrees) where the arc begins 790 @param sweepAngle Sweep angle (in degrees) measured clockwise 791 @param useCenter true means include the center of the oval. For filling 792 this will draw a wedge. False means just use the arc. 793 @param paint The paint used to draw the arc 794 */ 795 void drawArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, 796 bool useCenter, const SkPaint& paint); 797 798 /** Draw the specified round-rect using the specified paint. The round-rect 799 will be filled or framed based on the Style in the paint. 800 @param rect The rectangular bounds of the roundRect to be drawn 801 @param rx The x-radius of the oval used to round the corners 802 @param ry The y-radius of the oval used to round the corners 803 @param paint The paint used to draw the roundRect 804 */ 805 void drawRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, 806 const SkPaint& paint); 807 808 /** Draw the specified path using the specified paint. The path will be 809 filled or framed based on the Style in the paint. 810 @param path The path to be drawn 811 @param paint The paint used to draw the path 812 */ 813 virtual void drawPath(const SkPath& path, const SkPaint& paint); 814 815 virtual void drawImage(const SkImage* image, SkScalar left, SkScalar top, 816 const SkPaint* paint = NULL); 817 818 virtual void drawImageRect(const SkImage* image, const SkRect* src, 819 const SkRect& dst, 820 const SkPaint* paint = NULL); 821 822 /** Draw the specified bitmap, with its top/left corner at (x,y), using the 823 specified paint, transformed by the current matrix. Note: if the paint 824 contains a maskfilter that generates a mask which extends beyond the 825 bitmap's original width/height, then the bitmap will be drawn as if it 826 were in a Shader with CLAMP mode. Thus the color outside of the original 827 width/height will be the edge color replicated. 828 829 If a shader is present on the paint it will be ignored, except in the 830 case where the bitmap is kAlpha_8_SkColorType. In that case, the color is 831 generated by the shader. 832 833 @param bitmap The bitmap to be drawn 834 @param left The position of the left side of the bitmap being drawn 835 @param top The position of the top side of the bitmap being drawn 836 @param paint The paint used to draw the bitmap, or NULL 837 */ 838 virtual void drawBitmap(const SkBitmap& bitmap, SkScalar left, SkScalar top, 839 const SkPaint* paint = NULL); 840 841 enum DrawBitmapRectFlags { 842 kNone_DrawBitmapRectFlag = 0x0, 843 /** 844 * When filtering is enabled, allow the color samples outside of 845 * the src rect (but still in the src bitmap) to bleed into the 846 * drawn portion 847 */ 848 kBleed_DrawBitmapRectFlag = 0x1, 849 }; 850 851 /** Draw the specified bitmap, with the specified matrix applied (before the 852 canvas' matrix is applied). 853 @param bitmap The bitmap to be drawn 854 @param src Optional: specify the subset of the bitmap to be drawn 855 @param dst The destination rectangle where the scaled/translated 856 image will be drawn 857 @param paint The paint used to draw the bitmap, or NULL 858 */ 859 virtual void drawBitmapRectToRect(const SkBitmap& bitmap, const SkRect* src, 860 const SkRect& dst, 861 const SkPaint* paint = NULL, 862 DrawBitmapRectFlags flags = kNone_DrawBitmapRectFlag); 863 864 void drawBitmapRect(const SkBitmap& bitmap, const SkRect& dst, 865 const SkPaint* paint = NULL) { 866 this->drawBitmapRectToRect(bitmap, NULL, dst, paint, kNone_DrawBitmapRectFlag); 867 } 868 869 void drawBitmapRect(const SkBitmap& bitmap, const SkIRect* isrc, 870 const SkRect& dst, const SkPaint* paint = NULL, 871 DrawBitmapRectFlags flags = kNone_DrawBitmapRectFlag) { 872 SkRect realSrcStorage; 873 SkRect* realSrcPtr = NULL; 874 if (isrc) { 875 realSrcStorage.set(*isrc); 876 realSrcPtr = &realSrcStorage; 877 } 878 this->drawBitmapRectToRect(bitmap, realSrcPtr, dst, paint, flags); 879 } 880 881 virtual void drawBitmapMatrix(const SkBitmap& bitmap, const SkMatrix& m, 882 const SkPaint* paint = NULL); 883 884 /** 885 * Draw the bitmap stretched differentially to fit into dst. 886 * center is a rect within the bitmap, and logically divides the bitmap 887 * into 9 sections (3x3). For example, if the middle pixel of a [5x5] 888 * bitmap is the "center", then the center-rect should be [2, 2, 3, 3]. 889 * 890 * If the dst is >= the bitmap size, then... 891 * - The 4 corners are not stretched at all. 892 * - The sides are stretched in only one axis. 893 * - The center is stretched in both axes. 894 * Else, for each axis where dst < bitmap, 895 * - The corners shrink proportionally 896 * - The sides (along the shrink axis) and center are not drawn 897 */ 898 virtual void drawBitmapNine(const SkBitmap& bitmap, const SkIRect& center, 899 const SkRect& dst, const SkPaint* paint = NULL); 900 901 /** Draw the specified bitmap, with its top/left corner at (x,y), 902 NOT transformed by the current matrix. Note: if the paint 903 contains a maskfilter that generates a mask which extends beyond the 904 bitmap's original width/height, then the bitmap will be drawn as if it 905 were in a Shader with CLAMP mode. Thus the color outside of the original 906 width/height will be the edge color replicated. 907 @param bitmap The bitmap to be drawn 908 @param left The position of the left side of the bitmap being drawn 909 @param top The position of the top side of the bitmap being drawn 910 @param paint The paint used to draw the bitmap, or NULL 911 */ 912 virtual void drawSprite(const SkBitmap& bitmap, int left, int top, 913 const SkPaint* paint = NULL); 914 915 /** Draw the text, with origin at (x,y), using the specified paint. 916 The origin is interpreted based on the Align setting in the paint. 917 @param text The text to be drawn 918 @param byteLength The number of bytes to read from the text parameter 919 @param x The x-coordinate of the origin of the text being drawn 920 @param y The y-coordinate of the origin of the text being drawn 921 @param paint The paint used for the text (e.g. color, size, style) 922 */ 923 SK_LEGACY_DRAWTEXT_VIRTUAL void drawText(const void* text, size_t byteLength, SkScalar x, 924 SkScalar y, const SkPaint& paint); 925 926 /** Draw the text, with each character/glyph origin specified by the pos[] 927 array. The origin is interpreted by the Align setting in the paint. 928 @param text The text to be drawn 929 @param byteLength The number of bytes to read from the text parameter 930 @param pos Array of positions, used to position each character 931 @param paint The paint used for the text (e.g. color, size, style) 932 */ 933 SK_LEGACY_DRAWTEXT_VIRTUAL void drawPosText(const void* text, size_t byteLength, 934 const SkPoint pos[], const SkPaint& paint); 935 936 /** Draw the text, with each character/glyph origin specified by the x 937 coordinate taken from the xpos[] array, and the y from the constY param. 938 The origin is interpreted by the Align setting in the paint. 939 @param text The text to be drawn 940 @param byteLength The number of bytes to read from the text parameter 941 @param xpos Array of x-positions, used to position each character 942 @param constY The shared Y coordinate for all of the positions 943 @param paint The paint used for the text (e.g. color, size, style) 944 */ 945 SK_LEGACY_DRAWTEXT_VIRTUAL void drawPosTextH(const void* text, size_t byteLength, 946 const SkScalar xpos[], SkScalar constY, 947 const SkPaint& paint); 948 949 /** Draw the text, with origin at (x,y), using the specified paint, along 950 the specified path. The paint's Align setting determins where along the 951 path to start the text. 952 @param text The text to be drawn 953 @param byteLength The number of bytes to read from the text parameter 954 @param path The path the text should follow for its baseline 955 @param hOffset The distance along the path to add to the text's 956 starting position 957 @param vOffset The distance above(-) or below(+) the path to 958 position the text 959 @param paint The paint used for the text 960 */ 961 void drawTextOnPathHV(const void* text, size_t byteLength, 962 const SkPath& path, SkScalar hOffset, 963 SkScalar vOffset, const SkPaint& paint); 964 965 /** Draw the text, with origin at (x,y), using the specified paint, along 966 the specified path. The paint's Align setting determins where along the 967 path to start the text. 968 @param text The text to be drawn 969 @param byteLength The number of bytes to read from the text parameter 970 @param path The path the text should follow for its baseline 971 @param matrix (may be null) Applied to the text before it is 972 mapped onto the path 973 @param paint The paint used for the text 974 */ 975 SK_LEGACY_DRAWTEXT_VIRTUAL void drawTextOnPath(const void* text, size_t byteLength, 976 const SkPath& path, const SkMatrix* matrix, 977 const SkPaint& paint); 978 979 /** Draw the text blob, offset by (x,y), using the specified paint. 980 @param blob The text blob to be drawn 981 @param x The x-offset of the text being drawn 982 @param y The y-offset of the text being drawn 983 @param paint The paint used for the text (e.g. color, size, style) 984 */ 985 void drawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y, const SkPaint& paint); 986 987 /** PRIVATE / EXPERIMENTAL -- do not call 988 Perform back-end analysis/optimization of a picture. This may attach 989 optimization data to the picture which can be used by a later 990 drawPicture call. 991 @param picture The recorded drawing commands to analyze/optimize 992 */ 993 void EXPERIMENTAL_optimize(const SkPicture* picture); 994 995 /** Draw the picture into this canvas. This method effective brackets the 996 playback of the picture's draw calls with save/restore, so the state 997 of this canvas will be unchanged after this call. 998 @param picture The recorded drawing commands to playback into this 999 canvas. 1000 */ 1001 void drawPicture(const SkPicture* picture); 1002 1003 /** 1004 * Draw the picture into this canvas. 1005 * 1006 * If matrix is non-null, apply that matrix to the CTM when drawing this picture. This is 1007 * logically equivalent to 1008 * save/concat/drawPicture/restore 1009 * 1010 * If paint is non-null, draw the picture into a temporary buffer, and then apply the paint's 1011 * alpha/colorfilter/imagefilter/xfermode to that buffer as it is drawn to the canvas. 1012 * This is logically equivalent to 1013 * saveLayer(paint)/drawPicture/restore 1014 */ 1015 void drawPicture(const SkPicture*, const SkMatrix* matrix, const SkPaint* paint); 1016 1017 enum VertexMode { 1018 kTriangles_VertexMode, 1019 kTriangleStrip_VertexMode, 1020 kTriangleFan_VertexMode 1021 }; 1022 1023 /** Draw the array of vertices, interpreted as triangles (based on mode). 1024 1025 If both textures and vertex-colors are NULL, it strokes hairlines with 1026 the paint's color. This behavior is a useful debugging mode to visualize 1027 the mesh. 1028 1029 @param vmode How to interpret the array of vertices 1030 @param vertexCount The number of points in the vertices array (and 1031 corresponding texs and colors arrays if non-null) 1032 @param vertices Array of vertices for the mesh 1033 @param texs May be null. If not null, specifies the coordinate 1034 in _texture_ space (not uv space) for each vertex. 1035 @param colors May be null. If not null, specifies a color for each 1036 vertex, to be interpolated across the triangle. 1037 @param xmode Used if both texs and colors are present. In this 1038 case the colors are combined with the texture using mode, 1039 before being drawn using the paint. If mode is null, then 1040 kModulate_Mode is used. 1041 @param indices If not null, array of indices to reference into the 1042 vertex (texs, colors) array. 1043 @param indexCount number of entries in the indices array (if not null) 1044 @param paint Specifies the shader/texture if present. 1045 */ 1046 virtual void drawVertices(VertexMode vmode, int vertexCount, 1047 const SkPoint vertices[], const SkPoint texs[], 1048 const SkColor colors[], SkXfermode* xmode, 1049 const uint16_t indices[], int indexCount, 1050 const SkPaint& paint); 1051 1052 /** 1053 Draw a cubic coons patch 1054 1055 @param cubic specifies the 4 bounding cubic bezier curves of a patch with clockwise order 1056 starting at the top left corner. 1057 @param colors specifies the colors for the corners which will be bilerp across the patch, 1058 their order is clockwise starting at the top left corner. 1059 @param texCoords specifies the texture coordinates that will be bilerp across the patch, 1060 their order is the same as the colors. 1061 @param xmode specifies how are the colors and the textures combined if both of them are 1062 present. 1063 @param paint Specifies the shader/texture if present. 1064 */ 1065 void drawPatch(const SkPoint cubics[12], const SkColor colors[4], 1066 const SkPoint texCoords[4], SkXfermode* xmode, const SkPaint& paint); 1067 1068 /** Send a blob of data to the canvas. 1069 For canvases that draw, this call is effectively a no-op, as the data 1070 is not parsed, but just ignored. However, this call exists for 1071 subclasses like SkPicture's recording canvas, that can store the data 1072 and then play it back later (via another call to drawData). 1073 */ 1074 virtual void drawData(const void* data, size_t length) { 1075 // do nothing. Subclasses may do something with the data 1076 } 1077 1078 /** Add comments. beginCommentGroup/endCommentGroup open/close a new group. 1079 Each comment added via addComment is notionally attached to its 1080 enclosing group. Top-level comments simply belong to no group. 1081 */ 1082 virtual void beginCommentGroup(const char* description) { 1083 // do nothing. Subclasses may do something 1084 } 1085 virtual void addComment(const char* kywd, const char* value) { 1086 // do nothing. Subclasses may do something 1087 } 1088 virtual void endCommentGroup() { 1089 // do nothing. Subclasses may do something 1090 } 1091 1092 /** 1093 * With this call the client asserts that subsequent draw operations (up to the 1094 * matching popCull()) are fully contained within the given bounding box. The assertion 1095 * is not enforced, but the information might be used to quick-reject command blocks, 1096 * so an incorrect bounding box may result in incomplete rendering. 1097 */ 1098 void pushCull(const SkRect& cullRect); 1099 1100 /** 1101 * Terminates the current culling block, and restores the previous one (if any). 1102 */ 1103 void popCull(); 1104 1105 ////////////////////////////////////////////////////////////////////////// 1106 1107 /** Get the current filter object. The filter's reference count is not 1108 affected. The filter is saved/restored, just like the matrix and clip. 1109 @return the canvas' filter (or NULL). 1110 */ 1111 SkDrawFilter* getDrawFilter() const; 1112 1113 /** Set the new filter (or NULL). Pass NULL to clear any existing filter. 1114 As a convenience, the parameter is returned. If an existing filter 1115 exists, its refcnt is decrement. If the new filter is not null, its 1116 refcnt is incremented. The filter is saved/restored, just like the 1117 matrix and clip. 1118 @param filter the new filter (or NULL) 1119 @return the new filter 1120 */ 1121 virtual SkDrawFilter* setDrawFilter(SkDrawFilter* filter); 1122 1123 ////////////////////////////////////////////////////////////////////////// 1124 1125 /** 1126 * Return true if the current clip is empty (i.e. nothing will draw). 1127 * Note: this is not always a free call, so it should not be used 1128 * more often than necessary. However, once the canvas has computed this 1129 * result, subsequent calls will be cheap (until the clip state changes, 1130 * which can happen on any clip..() or restore() call. 1131 */ 1132 virtual bool isClipEmpty() const; 1133 1134 /** 1135 * Returns true if the current clip is just a (non-empty) rectangle. 1136 * Returns false if the clip is empty, or if it is complex. 1137 */ 1138 virtual bool isClipRect() const; 1139 1140 /** Return the current matrix on the canvas. 1141 This does not account for the translate in any of the devices. 1142 @return The current matrix on the canvas. 1143 */ 1144 const SkMatrix& getTotalMatrix() const; 1145 1146 /** Return the clip stack. The clip stack stores all the individual 1147 * clips organized by the save/restore frame in which they were 1148 * added. 1149 * @return the current clip stack ("list" of individual clip elements) 1150 */ 1151 const SkClipStack* getClipStack() const { 1152 return &fClipStack; 1153 } 1154 1155 typedef SkCanvasClipVisitor ClipVisitor; 1156 /** 1157 * Replays the clip operations, back to front, that have been applied to 1158 * the canvas, calling the appropriate method on the visitor for each 1159 * clip. All clips have already been transformed into device space. 1160 */ 1161 void replayClips(ClipVisitor*) const; 1162 1163 /////////////////////////////////////////////////////////////////////////// 1164 1165 /** After calling saveLayer(), there can be any number of devices that make 1166 up the top-most drawing area. LayerIter can be used to iterate through 1167 those devices. Note that the iterator is only valid until the next API 1168 call made on the canvas. Ownership of all pointers in the iterator stays 1169 with the canvas, so none of them should be modified or deleted. 1170 */ 1171 class SK_API LayerIter /*: SkNoncopyable*/ { 1172 public: 1173 /** Initialize iterator with canvas, and set values for 1st device */ 1174 LayerIter(SkCanvas*, bool skipEmptyClips); 1175 ~LayerIter(); 1176 1177 /** Return true if the iterator is done */ 1178 bool done() const { return fDone; } 1179 /** Cycle to the next device */ 1180 void next(); 1181 1182 // These reflect the current device in the iterator 1183 1184 SkBaseDevice* device() const; 1185 const SkMatrix& matrix() const; 1186 const SkRegion& clip() const; 1187 const SkPaint& paint() const; 1188 int x() const; 1189 int y() const; 1190 1191 private: 1192 // used to embed the SkDrawIter object directly in our instance, w/o 1193 // having to expose that class def to the public. There is an assert 1194 // in our constructor to ensure that fStorage is large enough 1195 // (though needs to be a compile-time-assert!). We use intptr_t to work 1196 // safely with 32 and 64 bit machines (to ensure the storage is enough) 1197 intptr_t fStorage[32]; 1198 class SkDrawIter* fImpl; // this points at fStorage 1199 SkPaint fDefaultPaint; 1200 bool fDone; 1201 }; 1202 1203 // don't call 1204 GrRenderTarget* internal_private_accessTopLayerRenderTarget(); 1205 1206 protected: 1207 // default impl defers to getDevice()->newSurface(info) 1208 virtual SkSurface* onNewSurface(const SkImageInfo&, const SkSurfaceProps&); 1209 1210 // default impl defers to its device 1211 virtual const void* onPeekPixels(SkImageInfo*, size_t* rowBytes); 1212 virtual void* onAccessTopLayerPixels(SkImageInfo*, size_t* rowBytes); 1213 1214 // Subclass save/restore notifiers. 1215 // Overriders should call the corresponding INHERITED method up the inheritance chain. 1216 // willSaveLayer()'s return value may suppress full layer allocation. 1217 enum SaveLayerStrategy { 1218 kFullLayer_SaveLayerStrategy, 1219 kNoLayer_SaveLayerStrategy 1220 }; 1221 1222 virtual void willSave() {} 1223 virtual SaveLayerStrategy willSaveLayer(const SkRect*, const SkPaint*, SaveFlags) { 1224 return kFullLayer_SaveLayerStrategy; 1225 } 1226 virtual void willRestore() {} 1227 virtual void didRestore() {} 1228 virtual void didConcat(const SkMatrix&) {} 1229 virtual void didSetMatrix(const SkMatrix&) {} 1230 1231 virtual void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&); 1232 1233 virtual void onDrawText(const void* text, size_t byteLength, SkScalar x, 1234 SkScalar y, const SkPaint& paint); 1235 1236 virtual void onDrawPosText(const void* text, size_t byteLength, 1237 const SkPoint pos[], const SkPaint& paint); 1238 1239 virtual void onDrawPosTextH(const void* text, size_t byteLength, 1240 const SkScalar xpos[], SkScalar constY, 1241 const SkPaint& paint); 1242 1243 virtual void onDrawTextOnPath(const void* text, size_t byteLength, 1244 const SkPath& path, const SkMatrix* matrix, 1245 const SkPaint& paint); 1246 1247 virtual void onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y, 1248 const SkPaint& paint); 1249 1250 virtual void onDrawPatch(const SkPoint cubics[12], const SkColor colors[4], 1251 const SkPoint texCoords[4], SkXfermode* xmode, const SkPaint& paint); 1252 1253 enum ClipEdgeStyle { 1254 kHard_ClipEdgeStyle, 1255 kSoft_ClipEdgeStyle 1256 }; 1257 1258 virtual void onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle edgeStyle); 1259 virtual void onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle edgeStyle); 1260 virtual void onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle edgeStyle); 1261 virtual void onClipRegion(const SkRegion& deviceRgn, SkRegion::Op op); 1262 1263 virtual void onDiscard(); 1264 1265 virtual void onDrawPicture(const SkPicture*, const SkMatrix*, const SkPaint*); 1266 1267 // Returns the canvas to be used by DrawIter. Default implementation 1268 // returns this. Subclasses that encapsulate an indirect canvas may 1269 // need to overload this method. The impl must keep track of this, as it 1270 // is not released or deleted by the caller. 1271 virtual SkCanvas* canvasForDrawIter(); 1272 1273 // Clip rectangle bounds. Called internally by saveLayer. 1274 // returns false if the entire rectangle is entirely clipped out 1275 // If non-NULL, The imageFilter parameter will be used to expand the clip 1276 // and offscreen bounds for any margin required by the filter DAG. 1277 bool clipRectBounds(const SkRect* bounds, SaveFlags flags, 1278 SkIRect* intersection, 1279 const SkImageFilter* imageFilter = NULL); 1280 1281 // notify our surface (if we have one) that we are about to draw, so it 1282 // can perform copy-on-write or invalidate any cached images 1283 void predrawNotify(); 1284 1285 virtual void onPushCull(const SkRect& cullRect); 1286 virtual void onPopCull(); 1287 1288 private: 1289 class MCRec; 1290 1291 SkClipStack fClipStack; 1292 SkDeque fMCStack; 1293 // points to top of stack 1294 MCRec* fMCRec; 1295 // the first N recs that can fit here mean we won't call malloc 1296 uint32_t fMCRecStorage[32]; 1297 1298 const SkSurfaceProps fProps; 1299 1300 int fSaveLayerCount; // number of successful saveLayer calls 1301 int fCullCount; // number of active culls 1302 1303 SkMetaData* fMetaData; 1304 1305 SkSurface_Base* fSurfaceBase; 1306 SkSurface_Base* getSurfaceBase() const { return fSurfaceBase; } 1307 void setSurfaceBase(SkSurface_Base* sb) { 1308 fSurfaceBase = sb; 1309 } 1310 friend class SkSurface_Base; 1311 friend class SkSurface_Gpu; 1312 1313 bool fDeviceCMDirty; // cleared by updateDeviceCMCache() 1314 void updateDeviceCMCache(); 1315 1316 friend class SkDrawIter; // needs setupDrawForLayerDevice() 1317 friend class AutoDrawLooper; 1318 friend class SkLua; // needs top layer size and offset 1319 friend class SkDebugCanvas; // needs experimental fAllowSimplifyClip 1320 friend class SkDeferredDevice; // needs getTopDevice() 1321 friend class SkSurface_Raster; // needs getDevice() 1322 friend class SkRecorder; // InitFlags 1323 friend class SkNoSaveLayerCanvas; // InitFlags 1324 1325 enum InitFlags { 1326 kDefault_InitFlags = 0, 1327 kConservativeRasterClip_InitFlag = 1 << 0, 1328 }; 1329 SkCanvas(int width, int height, InitFlags); 1330 SkCanvas(SkBaseDevice*, const SkSurfaceProps*, InitFlags); 1331 SkCanvas(const SkBitmap&, const SkSurfaceProps&); 1332 1333 // needs gettotalclip() 1334 friend SkCanvasState* SkCanvasStateUtils::CaptureCanvasState(SkCanvas*); 1335 1336 SkBaseDevice* createLayerDevice(const SkImageInfo&); 1337 1338 // call this each time we attach ourselves to a device 1339 // - constructor 1340 // - internalSaveLayer 1341 void setupDevice(SkBaseDevice*); 1342 1343 SkBaseDevice* init(SkBaseDevice*, InitFlags); 1344 1345 /** 1346 * DEPRECATED 1347 * 1348 * Specify a device for this canvas to draw into. If it is not null, its 1349 * reference count is incremented. If the canvas was already holding a 1350 * device, its reference count is decremented. The new device is returned. 1351 */ 1352 SkBaseDevice* setRootDevice(SkBaseDevice* device); 1353 1354 /** 1355 * Gets the size/origin of the top level layer in global canvas coordinates. We don't want this 1356 * to be public because it exposes decisions about layer sizes that are internal to the canvas. 1357 */ 1358 SkISize getTopLayerSize() const; 1359 SkIPoint getTopLayerOrigin() const; 1360 1361 // internal methods are not virtual, so they can safely be called by other 1362 // canvas apis, without confusing subclasses (like SkPictureRecording) 1363 void internalDrawBitmap(const SkBitmap&, const SkMatrix& m, const SkPaint* paint); 1364 void internalDrawBitmapRect(const SkBitmap& bitmap, const SkRect* src, 1365 const SkRect& dst, const SkPaint* paint, 1366 DrawBitmapRectFlags flags); 1367 void internalDrawBitmapNine(const SkBitmap& bitmap, const SkIRect& center, 1368 const SkRect& dst, const SkPaint* paint); 1369 void internalDrawPaint(const SkPaint& paint); 1370 int internalSaveLayer(const SkRect* bounds, const SkPaint* paint, 1371 SaveFlags, bool justForImageFilter, SaveLayerStrategy strategy); 1372 void internalDrawDevice(SkBaseDevice*, int x, int y, const SkPaint*); 1373 1374 // shared by save() and saveLayer() 1375 int internalSave(); 1376 void internalRestore(); 1377 static void DrawRect(const SkDraw& draw, const SkPaint& paint, 1378 const SkRect& r, SkScalar textSize); 1379 static void DrawTextDecorations(const SkDraw& draw, const SkPaint& paint, 1380 const char text[], size_t byteLength, 1381 SkScalar x, SkScalar y); 1382 1383 // only for canvasutils 1384 const SkRegion& internal_private_getTotalClip() const; 1385 1386 /* These maintain a cache of the clip bounds in local coordinates, 1387 (converted to 2s-compliment if floats are slow). 1388 */ 1389 mutable SkRect fCachedLocalClipBounds; 1390 mutable bool fCachedLocalClipBoundsDirty; 1391 bool fAllowSoftClip; 1392 bool fAllowSimplifyClip; 1393 bool fConservativeRasterClip; 1394 1395 const SkRect& getLocalClipBounds() const { 1396 if (fCachedLocalClipBoundsDirty) { 1397 if (!this->getClipBounds(&fCachedLocalClipBounds)) { 1398 fCachedLocalClipBounds.setEmpty(); 1399 } 1400 fCachedLocalClipBoundsDirty = false; 1401 } 1402 return fCachedLocalClipBounds; 1403 } 1404 1405 class AutoValidateClip : ::SkNoncopyable { 1406 public: 1407 explicit AutoValidateClip(SkCanvas* canvas) : fCanvas(canvas) { 1408 fCanvas->validateClip(); 1409 } 1410 ~AutoValidateClip() { fCanvas->validateClip(); } 1411 1412 private: 1413 const SkCanvas* fCanvas; 1414 }; 1415 1416 #ifdef SK_DEBUG 1417 // The cull stack rects are in device-space 1418 SkTDArray<SkIRect> fCullStack; 1419 void validateCull(const SkIRect&); 1420 void validateClip() const; 1421 #else 1422 void validateClip() const {} 1423 #endif 1424 1425 typedef SkRefCnt INHERITED; 1426 }; 1427 1428 /** Stack helper class to automatically call restoreToCount() on the canvas 1429 when this object goes out of scope. Use this to guarantee that the canvas 1430 is restored to a known state. 1431 */ 1432 class SkAutoCanvasRestore : SkNoncopyable { 1433 public: 1434 SkAutoCanvasRestore(SkCanvas* canvas, bool doSave) : fCanvas(canvas), fSaveCount(0) { 1435 if (fCanvas) { 1436 fSaveCount = canvas->getSaveCount(); 1437 if (doSave) { 1438 canvas->save(); 1439 } 1440 } 1441 } 1442 ~SkAutoCanvasRestore() { 1443 if (fCanvas) { 1444 fCanvas->restoreToCount(fSaveCount); 1445 } 1446 } 1447 1448 /** 1449 * Perform the restore now, instead of waiting for the destructor. Will 1450 * only do this once. 1451 */ 1452 void restore() { 1453 if (fCanvas) { 1454 fCanvas->restoreToCount(fSaveCount); 1455 fCanvas = NULL; 1456 } 1457 } 1458 1459 private: 1460 SkCanvas* fCanvas; 1461 int fSaveCount; 1462 }; 1463 #define SkAutoCanvasRestore(...) SK_REQUIRE_LOCAL_VAR(SkAutoCanvasRestore) 1464 1465 /** Stack helper class to automatically open and close a comment block 1466 */ 1467 class SkAutoCommentBlock : SkNoncopyable { 1468 public: 1469 SkAutoCommentBlock(SkCanvas* canvas, const char* description) { 1470 fCanvas = canvas; 1471 if (fCanvas) { 1472 fCanvas->beginCommentGroup(description); 1473 } 1474 } 1475 1476 ~SkAutoCommentBlock() { 1477 if (fCanvas) { 1478 fCanvas->endCommentGroup(); 1479 } 1480 } 1481 1482 private: 1483 SkCanvas* fCanvas; 1484 }; 1485 #define SkAutoCommentBlock(...) SK_REQUIRE_LOCAL_VAR(SkAutoCommentBlock) 1486 1487 /** 1488 * If the caller wants read-only access to the pixels in a canvas, it can just 1489 * call canvas->peekPixels(), since that is the fastest way to "peek" at the 1490 * pixels on a raster-backed canvas. 1491 * 1492 * If the canvas has pixels, but they are not readily available to the CPU 1493 * (e.g. gpu-backed), then peekPixels() will fail, but readPixels() will 1494 * succeed (though be slower, since it will return a copy of the pixels). 1495 * 1496 * SkAutoROCanvasPixels encapsulates these two techniques, trying first to call 1497 * peekPixels() (for performance), but if that fails, calling readPixels() and 1498 * storing the copy locally. 1499 * 1500 * The caller must respect the restrictions associated with peekPixels(), since 1501 * that may have been called: The returned information is invalidated if... 1502 * - any API is called on the canvas (or its parent surface if present) 1503 * - the canvas goes out of scope 1504 */ 1505 class SkAutoROCanvasPixels : SkNoncopyable { 1506 public: 1507 SkAutoROCanvasPixels(SkCanvas* canvas); 1508 1509 // returns NULL on failure 1510 const void* addr() const { return fAddr; } 1511 1512 // undefined if addr() == NULL 1513 size_t rowBytes() const { return fRowBytes; } 1514 1515 // undefined if addr() == NULL 1516 const SkImageInfo& info() const { return fInfo; } 1517 1518 // helper that, if returns true, installs the pixels into the bitmap. Note 1519 // that the bitmap may reference the address returned by peekPixels(), so 1520 // the caller must respect the restrictions associated with peekPixels(). 1521 bool asROBitmap(SkBitmap*) const; 1522 1523 private: 1524 SkBitmap fBitmap; // used if peekPixels() fails 1525 const void* fAddr; // NULL on failure 1526 SkImageInfo fInfo; 1527 size_t fRowBytes; 1528 }; 1529 1530 static inline SkCanvas::SaveFlags operator|(const SkCanvas::SaveFlags lhs, 1531 const SkCanvas::SaveFlags rhs) { 1532 return static_cast<SkCanvas::SaveFlags>(static_cast<int>(lhs) | static_cast<int>(rhs)); 1533 } 1534 1535 static inline SkCanvas::SaveFlags& operator|=(SkCanvas::SaveFlags& lhs, 1536 const SkCanvas::SaveFlags rhs) { 1537 lhs = lhs | rhs; 1538 return lhs; 1539 } 1540 1541 class SkCanvasClipVisitor { 1542 public: 1543 virtual ~SkCanvasClipVisitor(); 1544 virtual void clipRect(const SkRect&, SkRegion::Op, bool antialias) = 0; 1545 virtual void clipRRect(const SkRRect&, SkRegion::Op, bool antialias) = 0; 1546 virtual void clipPath(const SkPath&, SkRegion::Op, bool antialias) = 0; 1547 }; 1548 1549 #endif 1550
