Cary Clark | 8032b98 | 2017-07-28 11:04:54 -0400 | [diff] [blame^] | 1 | #Topic Canvas |
| 2 | |
| 3 | Canvas provides an interface for drawing, and how the drawing is clipped and transformed. |
| 4 | Canvas contains a stack of Matrix and Clip values. |
| 5 | |
| 6 | Canvas and Paint together provide the state to draw into Surface or Device. |
| 7 | Each Canvas draw call transforms the geometry of the object by the concatenation of all Matrix |
| 8 | values in the stack. |
| 9 | The transformed geometry is clipped by the intersection of all of Clip values in the stack. |
| 10 | The Canvas draw calls take Paint parameter for drawing state. |
| 11 | Create Paint to supply the drawing state, such as Color, |
| 12 | Typeface, Paint_Text_Size, Paint_Stroke_Width, Shader and so on. |
| 13 | |
| 14 | To draw to a pixel-based destination, create Raster_Surface or GPU_Surface. |
| 15 | Request Canvas from Surface to obtain the interface to draw. |
| 16 | Canvas generated by Raster_Surface draws to memory visible to the CPU. |
| 17 | Canvas generated by GPU_Surface uses Vulkan or OpenGL to draw to the GPU. |
| 18 | |
| 19 | Canvas can be constructed to draw to Bitmap without first creating Raster_Surface. |
| 20 | This approach may be deprecated in the future. |
| 21 | |
| 22 | To draw to a document, obtain Canvas from SVG_Canvas, Document_PDF, or Picture_Recorder. |
| 23 | Document-based Canvas and other Canvas subclasses reference Device describing the destination. |
| 24 | |
| 25 | #Class SkCanvas |
| 26 | |
| 27 | #Topic Overview |
| 28 | |
| 29 | #Subtopic Subtopics |
| 30 | #Table |
| 31 | #Legend |
| 32 | # topics # description ## |
| 33 | #Legend ## |
| 34 | #ToDo generate a TOC here ## |
| 35 | #Table ## |
| 36 | #Subtopic ## |
| 37 | |
| 38 | #Subtopic Constants |
| 39 | #Table |
| 40 | #Legend |
| 41 | # constants # description ## |
| 42 | #Legend ## |
| 43 | # Lattice::Flags # Controls Lattice transparency. ## |
| 44 | # PointMode # Sets drawPoints options. ## |
| 45 | # SaveLayerFlags # Sets SaveLayerRec options. ## |
| 46 | # SrcRectConstraint # Sets drawImageRect options. ## |
| 47 | #Table ## |
| 48 | #Subtopic ## |
| 49 | |
| 50 | #Subtopic Structs |
| 51 | #Table |
| 52 | #Legend |
| 53 | # struct # description ## |
| 54 | #Legend ## |
| 55 | # Lattice # Divides Bitmap, Image into a rectangular grid. ## |
| 56 | # SaveLayerRec # Contains state to create the layer offscreen. ## |
| 57 | #Table ## |
| 58 | #Subtopic ## |
| 59 | |
| 60 | #Subtopic Constructors |
| 61 | |
| 62 | Create the desired type of Surface to obtain its Canvas when possible. Constructors are useful |
| 63 | when no Surface is required, and some helpers implicitly create Raster_Surface. |
| 64 | |
| 65 | #Table |
| 66 | #Legend |
| 67 | # # description ## |
| 68 | #Legend ## |
| 69 | # SkCanvas() # No Surface, no dimensions. ## |
| 70 | # SkCanvas(int width, int height, const SkSurfaceProps* = NULL) # No Surface, set dimensions, Surface_Properties. ## |
| 71 | # SkCanvas(SkBaseDevice* device) # Existing Device. (SkBaseDevice is private.) ## |
| 72 | # SkCanvas(const SkBitmap& bitmap) # Uses existing Bitmap. ## |
| 73 | # SkCanvas(const SkBitmap& bitmap, const SkSurfaceProps& props) # Uses existing Bitmap and Surface_Properties. ## |
| 74 | # MakeRasterDirect # Creates from SkImageInfo and Pixel_Storage. ## |
| 75 | # MakeRasterDirectN32 # Creates from image data and Pixel_Storage. ## |
| 76 | #ToDo incomplete ## |
| 77 | #Table ## |
| 78 | #Subtopic ## |
| 79 | |
| 80 | #Subtopic Member_Functions |
| 81 | #Table |
| 82 | #Legend |
| 83 | # function # description ## |
| 84 | #Legend ## |
| 85 | # accessTopLayerPixels # Returns writable pixel access if available. ## |
| 86 | # accessTopRasterHandle # Returns context that tracks Clip and Matrix. ## |
| 87 | # clear() # Fills Clip with Color. ## |
| 88 | # clipPath # Combines Clip with Path. ## |
| 89 | # clipRRect # Combines Clip with Round_Rect. ## |
| 90 | # clipRect # Combines Clip with Rect. ## |
| 91 | # clipRegion # Combines Clip with Region. ## |
| 92 | # concat() # Multiplies Matrix by Matrix. ## |
| 93 | # discard() # Makes Canvas contents undefined. ## |
| 94 | # drawAnnotation # Associates a Rect with a key-value pair.## |
| 95 | # drawArc # Draws Arc using Clip, Matrix, and Paint.## |
| 96 | # drawAtlas # Draws sprites using Clip, Matrix, and Paint.## |
| 97 | # drawBitmap # Draws Bitmap at (x, y) position. ## |
| 98 | # drawBitmapLattice # Draws differentially stretched Bitmap. ## |
| 99 | # drawBitmapNine # Draws Nine_Patch Bitmap. ## |
| 100 | # drawBitmapRect # Draws Bitmap, source Rect to destination Rect. ## |
| 101 | # drawCircle # Draws Circle using Clip, Matrix, and Paint. ## |
| 102 | # drawColor # Fills Clip with Color and Blend_Mode. ## |
| 103 | # drawDRRect # Draws double Round_Rect stroked or filled. ## |
| 104 | # drawDrawable # Draws Drawable, encapsulated drawing commands. ## |
| 105 | # drawIRect # Draws IRect using Clip, Matrix, and Paint. ## |
| 106 | # drawImage # Draws Image at (x, y) position. ## |
| 107 | # drawImageLattice # Draws differentially stretched Image. ## |
| 108 | # drawImageNine # Draws Nine_Patch Image. ## |
| 109 | # drawImageRect # Draws Image, source Rect to destination Rect. ## |
| 110 | # drawLine # Draws line segment between two points.## |
| 111 | # drawOval # Draws Oval using Clip, Matrix, and Paint. ## |
| 112 | # drawPaint # Fills Clip with Paint. ## |
| 113 | # drawPatch # Draws cubic Coons patch. ## |
| 114 | # drawPath # Draws Path using Clip, Matrix, and Paint. ## |
| 115 | # drawPicture # Draws Picture using Clip and Matrix. ## |
| 116 | # drawPoint # Draws point at (x, y) position. ## |
| 117 | # drawPoints # Draws array as points, lines, polygon. ## |
| 118 | # drawPosText # Draws text at array of (x, y) positions. ## |
| 119 | # drawPosTextH # Draws text at x positions with common baseline. ## |
| 120 | # drawRRect # Draws Round_Rect using Clip, Matrix, and Paint. ## |
| 121 | # drawRect # Draws Rect using Clip, Matrix, and Paint. ## |
| 122 | # drawRegion # Draws Region using Clip, Matrix, and Paint. ## |
| 123 | # drawRoundRect # Draws Round_Rect using Clip, Matrix, and Paint. ## |
| 124 | # drawText # Draws text at (x, y), using font advance. ## |
| 125 | # drawTextBlob # Draws text with arrays of positions and Paint. ## |
| 126 | # drawTextOnPath # Draws text following Path contour. ## |
| 127 | # drawTextOnPathHV # Draws text following Path with offsets. ## |
| 128 | # drawTextRSXform # Draws text with array of RSXform. ## |
| 129 | # drawString # Draws null terminated string at (x, y) using font advance. ## |
| 130 | # drawVertices # Draws Vertices, a triangle mesh. ## |
| 131 | # flush() # Triggers execution of all pending draw operations. ## |
| 132 | # getBaseLayerSize # Gets size of base layer in global coordinates. ## |
| 133 | # getDeviceClipBounds # Returns IRect bounds of Clip. ## |
| 134 | # getDrawFilter # Legacy; to be deprecated. ## |
| 135 | # getGrContext # Returns GPU_Context of the GPU_Surface. ## |
| 136 | # getLocalClipBounds # Returns Clip bounds in source coordinates. ## |
| 137 | # getMetaData # Associates additional data with the canvas. ## |
| 138 | # getProps # Copies Surface_Properties if available. ## |
| 139 | # getSaveCount # Returns depth of stack containing Clip and Matrix. ## |
| 140 | # getTotalMatrix # Returns Matrix. ## |
| 141 | # imageInfo # Returns Image_Info for Canvas. ## |
| 142 | # isClipEmpty # Returns if Clip is empty. ## |
| 143 | # isClipRect # Returns if Clip is Rect and not empty. ## |
| 144 | # MakeRasterDirect # Creates Canvas from SkImageInfo and pixel data. ## |
| 145 | # MakeRasterDirectN32 # Creates Canvas from image specifications and pixel data. ## |
| 146 | # makeSurface # Creates Surface matching SkImageInfo and SkSurfaceProps. ## |
| 147 | # peekPixels # Returns if Canvas has direct access to its pixels. ## |
| 148 | # quickReject # Returns if Rect is outside Clip. ## |
| 149 | # readPixels # Copies and converts rectangle of pixels from Canvas. ## |
| 150 | # resetMatrix # Resets Matrix to identity. ## |
| 151 | # restore() # Restores changes to Clip and Matrix, pops save stack. ## |
| 152 | # restoreToCount # Restores changes to Clip and Matrix to given depth. ## |
| 153 | # rotate() # Rotates Matrix. ## |
| 154 | # save() # Saves Clip and Matrix on stack. ## |
| 155 | # saveLayer # Saves Clip and Matrix on stack; creates offscreen. ## |
| 156 | # saveLayerAlpha # Saves Clip and Matrix on stack; creates offscreen; sets opacity. ## |
| 157 | # saveLayerPreserveLCDTextRequests # Saves Clip and Matrix on stack; creates offscreen for LCD text. ## |
| 158 | # scale() # Scales Matrix. ## |
| 159 | # setAllowSimplifyClip # Experimental. ## |
| 160 | # setDrawFilter # Legacy; to be deprecated. ## |
| 161 | # setMatrix # Sets Matrix. ## |
| 162 | # skew() # Skews Matrix. # |
| 163 | # translate() # Translates Matrix. ## |
| 164 | # writePixels # Copies and converts rectangle of pixels to Canvas. ## |
| 165 | #Table ## |
| 166 | #Subtopic ## |
| 167 | |
| 168 | #Topic Overview ## |
| 169 | |
| 170 | # ------------------------------------------------------------------------------ |
| 171 | |
| 172 | #Method static std::unique_ptr<SkCanvas> MakeRasterDirect(const SkImageInfo& info, |
| 173 | void* pixels, size_t rowBytes) |
| 174 | |
| 175 | Allocates raster canvas that will draw directly into pixels. |
| 176 | To access pixels after drawing, call flush() or peekPixels. |
| 177 | |
| 178 | #Param info Width, height, Image_Color_Type, Image_Alpha_Type, Color_Space, of Raster_Surface. |
| 179 | Width, or height, or both, may be zero. |
| 180 | ## |
| 181 | #Param pixels Pointer to destination pixels buffer. Buffer size should be info height |
| 182 | times rowBytes times bytes required for Image_Color_Type. |
| 183 | ## |
| 184 | #Param rowBytes The interval from one Surface row to the next; equal to or greater than |
| 185 | info width times bytes required for Image_Color_Type. |
| 186 | ## |
| 187 | |
| 188 | #Return Canvas if all parameters are valid; otherwise, nullptr. |
| 189 | Valid parameters include: info dimensions must be zero or positive, and other checks; |
| 190 | info must contain Image_Color_Type and Image_Alpha_Type supported by Raster_Surface; |
| 191 | pixels must be not be nullptr; |
| 192 | rowBytes must be zero or large enough to contain width pixels of Image_Color_Type. |
| 193 | ## |
| 194 | |
| 195 | #Example |
| 196 | #Description |
| 197 | Allocates a three by three bitmap, clears it to white, and draws a black pixel |
| 198 | in the center. |
| 199 | ## |
| 200 | void draw(SkCanvas* ) {
|
| 201 | SkImageInfo info = SkImageInfo::MakeN32Premul(3, 3); // device aligned, 32 bpp, premultipled
|
| 202 | const size_t minRowBytes = info.minRowBytes(); // bytes used by one bitmap row
|
| 203 | const size_t size = info.getSafeSize(minRowBytes); // bytes used by all rows
|
| 204 | SkAutoTMalloc<SkPMColor> storage(size); // allocate storage for pixels
|
| 205 | SkPMColor* pixels = storage.get(); // get pointer to allocated storage
|
| 206 | // create a SkCanvas backed by a raster device, and delete it when the
|
| 207 | // function goes out of scope.
|
| 208 | std::unique_ptr<SkCanvas> canvas = SkCanvas::MakeRasterDirect(info, pixels, minRowBytes);
|
| 209 | canvas->clear(SK_ColorWHITE); // white is unpremultiplied, in ARGB order
|
| 210 | canvas->flush(); // ensure that pixels are cleared
|
| 211 | SkPMColor pmWhite = pixels[0]; // the premultiplied format may vary
|
| 212 | SkPaint paint; // by default, draws black
|
| 213 | canvas->drawPoint(1, 1, paint); // draw in the center
|
| 214 | canvas->flush(); // ensure that point was drawn
|
| 215 | for (int y = 0; y < info.height(); ++y) {
|
| 216 | for (int x = 0; x < info.width(); ++x) {
|
| 217 | SkDebugf("%c", *pixels++ == pmWhite ? '-' : 'x');
|
| 218 | }
|
| 219 | SkDebugf("\n");
|
| 220 | }
|
| 221 | } |
| 222 | #StdOut |
| 223 | --- |
| 224 | -x- |
| 225 | --- |
| 226 | ## |
| 227 | ## |
| 228 | |
| 229 | #ToDo incomplete ## |
| 230 | |
| 231 | #SeeAlso MakeRasterDirectN32 SkSurface::MakeRasterDirect |
| 232 | ## |
| 233 | |
| 234 | # ------------------------------------------------------------------------------ |
| 235 | |
| 236 | #Method static std::unique_ptr<SkCanvas> MakeRasterDirectN32(int width, int height, SkPMColor* pixels, |
| 237 | size_t rowBytes) |
| 238 | |
| 239 | Creates Canvas with Raster_Surface with inline image specification that draws into pixels. |
| 240 | Image_Color_Type is set to kN32_SkColorType. |
| 241 | Image_Alpha_Type is set to kPremul_SkAlphaType. |
| 242 | To access pixels after drawing, call flush() or peekPixels. |
| 243 | |
| 244 | #Param width Pixel column count on Raster_Surface created. Must be zero or greater. ## |
| 245 | #Param height Pixel row count on Raster_Surface created. Must be zero or greater. ## |
| 246 | #Param pixels Pointer to destination pixels buffer. Buffer size should be height |
| 247 | times rowBytes times four. |
| 248 | ## |
| 249 | #Param rowBytes The interval from one Surface row to the next; equal to or greater than |
| 250 | width times four. |
| 251 | ## |
| 252 | |
| 253 | #Return Canvas if all parameters are valid; otherwise, nullptr. |
| 254 | Valid parameters include: width and height must be zero or positive; |
| 255 | pixels must be not be nullptr; |
| 256 | rowBytes must be zero or large enough to contain width pixels of Image_Color_Type. |
| 257 | ## |
| 258 | |
| 259 | #Example |
| 260 | #Description |
| 261 | Allocates a three by three bitmap, clears it to white, and draws a black pixel |
| 262 | in the center. |
| 263 | ## |
| 264 | void draw(SkCanvas* ) { |
| 265 | const int width = 3; |
| 266 | const int height = 3; |
| 267 | SkPMColor pixels[height][width]; // allocate a 3x3 premultiplied bitmap on the stack |
| 268 | // create a SkCanvas backed by a raster device, and delete it when the |
| 269 | // function goes out of scope. |
| 270 | std::unique_ptr<SkCanvas> canvas = SkCanvas::MakeRasterDirectN32( |
| 271 | width, |
| 272 | height, |
| 273 | pixels[0], // top left of the bitmap |
| 274 | sizeof(pixels[0])); // byte width of the each row |
| 275 | // write a pre-multiplied value for white into all pixels in the bitmap |
| 276 | canvas->clear(SK_ColorWHITE); |
| 277 | SkPMColor pmWhite = pixels[0][0]; // the premultiplied format may vary |
| 278 | SkPaint paint; // by default, draws black |
| 279 | canvas->drawPoint(1, 1, paint); // draw in the center |
| 280 | canvas->flush(); // ensure that pixels is ready to be read |
| 281 | for (int y = 0; y < height; ++y) { |
| 282 | for (int x = 0; x < width; ++x) { |
| 283 | SkDebugf("%c", pixels[y][x] == pmWhite ? '-' : 'x'); |
| 284 | } |
| 285 | SkDebugf("\n"); |
| 286 | } |
| 287 | } |
| 288 | #StdOut |
| 289 | --- |
| 290 | -x- |
| 291 | --- |
| 292 | ## |
| 293 | ## |
| 294 | |
| 295 | #ToDo incomplete ## |
| 296 | |
| 297 | ## |
| 298 | |
| 299 | # ------------------------------------------------------------------------------ |
| 300 | |
| 301 | #Method SkCanvas() |
| 302 | |
| 303 | Creates an empty canvas with no backing device/pixels, and zero |
| 304 | dimensions. |
| 305 | |
| 306 | #Return An empty canvas. ## |
| 307 | |
| 308 | #Example |
| 309 | |
| 310 | #Description |
| 311 | Passes a placeholder to a function that requires one. |
| 312 | ## |
| 313 | |
| 314 | #Function |
| 315 | // Returns true if either the canvas rotates the text by 90 degrees, or the paint does.
|
| 316 | static void check_for_up_and_down_text(const SkCanvas* canvas, const SkPaint& paint) {
|
| 317 | bool paintHasVertical = paint.isVerticalText();
|
| 318 | const SkMatrix& matrix = canvas->getTotalMatrix();
|
| 319 | bool matrixIsVertical = matrix.preservesRightAngles() && !matrix.isScaleTranslate();
|
| 320 | SkDebugf("paint draws text %s\n", paintHasVertical != matrixIsVertical ?
|
| 321 | "top to bottom" : "left to right");
|
| 322 | }
|
| 323 |
|
| 324 | static void check_for_up_and_down_text(const SkPaint& paint) {
|
| 325 | SkCanvas canvas; // placeholder only, does not have an associated device
|
| 326 | check_for_up_and_down_text(&canvas, paint);
|
| 327 | }
|
| 328 |
|
| 329 | ## |
| 330 | void draw(SkCanvas* canvas) {
|
| 331 | SkPaint paint;
|
| 332 | check_for_up_and_down_text(paint); // paint draws text left to right
|
| 333 | paint.setVerticalText(true);
|
| 334 | check_for_up_and_down_text(paint); // paint draws text top to bottom
|
| 335 | paint.setVerticalText(false);
|
| 336 | canvas->rotate(90);
|
| 337 | check_for_up_and_down_text(canvas, paint); // paint draws text top to bottom
|
| 338 | }
|
| 339 | |
| 340 | #StdOut |
| 341 | paint draws text left to right |
| 342 | paint draws text top to bottom |
| 343 | paint draws text top to bottom |
| 344 | ## |
| 345 | ## |
| 346 | |
| 347 | #ToDo incomplete ## |
| 348 | |
| 349 | ## |
| 350 | |
| 351 | # ------------------------------------------------------------------------------ |
| 352 | |
| 353 | #Method SkCanvas(int width, int height, const SkSurfaceProps* props = NULL) |
| 354 | |
| 355 | Creates Canvas of the specified dimensions without a Surface. |
| 356 | Used by subclasses with custom implementations for draw methods. |
| 357 | |
| 358 | #Param width Zero or greater. ## |
| 359 | #Param height Zero or greater. ## |
| 360 | #Param props The LCD striping orientation and setting for device independent fonts. |
| 361 | If nullptr, use Legacy_Font_Host settings. ## |
| 362 | |
| 363 | #Return Canvas placeholder with dimensions. ## |
| 364 | |
| 365 | #Example |
| 366 | SkCanvas canvas(10, 20); // 10 units wide, 20 units high |
| 367 | canvas.clipRect(SkRect::MakeXYWH(30, 40, 5, 10)); // clip is outside canvas' device |
| 368 | SkDebugf("canvas %s empty\n", canvas.getDeviceClipBounds().isEmpty() ? "is" : "is not"); |
| 369 | |
| 370 | #StdOut |
| 371 | canvas is empty |
| 372 | ## |
| 373 | ## |
| 374 | |
| 375 | #ToDo incomplete ## |
| 376 | |
| 377 | ## |
| 378 | |
| 379 | # ------------------------------------------------------------------------------ |
| 380 | |
| 381 | #Method explicit SkCanvas(SkBaseDevice* device) |
| 382 | |
| 383 | Construct a canvas that draws into device. |
| 384 | Used by child classes of SkCanvas. |
| 385 | |
| 386 | #ToDo Since SkBaseDevice is private, shouldn't this be private also? ## |
| 387 | |
| 388 | #Param device Specifies a device for the canvas to draw into. ## |
| 389 | |
| 390 | #Return Canvas that can be used to draw into device. ## |
| 391 | |
| 392 | #Example |
| 393 | #Error "Unsure how to create a meaningful example." |
| 394 | SkPDFCanvas::SkPDFCanvas(const sk_sp<SkPDFDevice>& dev) |
| 395 | : SkCanvas(dev.get()) {} |
| 396 | ## |
| 397 | |
| 398 | #ToDo either remove doc of figure out a way to fiddle it ## |
| 399 | |
| 400 | ## |
| 401 | |
| 402 | # ------------------------------------------------------------------------------ |
| 403 | |
| 404 | #Method explicit SkCanvas(const SkBitmap& bitmap) |
| 405 | |
| 406 | Construct a canvas that draws into bitmap. |
| 407 | Sets SkSurfaceProps::kLegacyFontHost_InitType in constructed Surface. |
| 408 | |
| 409 | #ToDo Should be deprecated? ## |
| 410 | |
| 411 | #Param bitmap Width, height, Image_Color_Type, Image_Alpha_Type, and pixel storage of Raster_Surface. |
| 412 | Bitmap is copied so that subsequently editing bitmap will not affect |
| 413 | constructed Canvas. |
| 414 | ## |
| 415 | |
| 416 | #Return Canvas that can be used to draw into bitmap. ## |
| 417 | |
| 418 | #Example |
| 419 | #Description |
| 420 | The actual output depends on the installed fonts. |
| 421 | ## |
| 422 | SkBitmap bitmap; |
| 423 | // create a bitmap 5 wide and 11 high |
| 424 | bitmap.allocPixels(SkImageInfo::MakeN32Premul(5, 11)); |
| 425 | SkCanvas canvas(bitmap); |
| 426 | canvas.clear(SK_ColorWHITE); // white is unpremultiplied, in ARGB order |
| 427 | SkPixmap pixmap; // provides guaranteed access to the drawn pixels |
| 428 | if (!canvas.peekPixels(&pixmap)) { |
| 429 | SkDebugf("peekPixels should never fail.\n"); |
| 430 | } |
| 431 | const SkPMColor* pixels = pixmap.addr32(); // points to top left of bitmap |
| 432 | SkPMColor pmWhite = pixels[0]; // the premultiplied format may vary |
| 433 | SkPaint paint; // by default, draws black, 12 point text |
| 434 | canvas.drawString("!", 1, 10, paint); // 1 char at baseline (1, 10) |
| 435 | for (int y = 0; y < bitmap.height(); ++y) { |
| 436 | for (int x = 0; x < bitmap.width(); ++x) { |
| 437 | SkDebugf("%c", *pixels++ == pmWhite ? '-' : 'x'); |
| 438 | } |
| 439 | SkDebugf("\n"); |
| 440 | } |
| 441 | |
| 442 | #StdOut |
| 443 | ----- |
| 444 | --x-- |
| 445 | --x-- |
| 446 | --x-- |
| 447 | --x-- |
| 448 | --x-- |
| 449 | --x-- |
| 450 | ----- |
| 451 | --x-- |
| 452 | --x-- |
| 453 | ----- |
| 454 | #StdOut ## |
| 455 | ## |
| 456 | |
| 457 | #ToDo incomplete ## |
| 458 | |
| 459 | ## |
| 460 | |
| 461 | #Enum ColorBehavior |
| 462 | |
| 463 | #ToDo exclude this during build phase |
| 464 | (use SK_BUILD_FOR_ANDROID_FRAMEWORK as exclude directive) |
| 465 | ## |
| 466 | |
| 467 | #Private |
| 468 | Android framework only. |
| 469 | ## |
| 470 | |
| 471 | #Code |
| 472 | enum class ColorBehavior { |
| 473 | kLegacy, |
| 474 | }; |
| 475 | ## |
| 476 | #Const kLegacy 0 |
| 477 | ## |
| 478 | ## |
| 479 | |
| 480 | |
| 481 | # ------------------------------------------------------------------------------ |
| 482 | |
| 483 | #Method SkCanvas(const SkBitmap& bitmap, const SkSurfaceProps& props) |
| 484 | |
| 485 | Construct a canvas that draws into bitmap. |
| 486 | Use props to match the device characteristics, like LCD striping. |
| 487 | |
| 488 | #Param bitmap Width, height, Image_Color_Type, Image_Alpha_Type, and pixel storage of Raster_Surface. |
| 489 | Bitmap is copied so that subsequently editing bitmap will not affect |
| 490 | constructed Canvas. |
| 491 | ## |
| 492 | #Param props The order and orientation of RGB striping; and whether to use |
| 493 | device independent fonts. |
| 494 | ## |
| 495 | |
| 496 | #Return Canvas that can be used to draw into bitmap. ## |
| 497 | |
| 498 | #Example |
| 499 | #Description |
| 500 | The actual output depends on the installed fonts. |
| 501 | ## |
| 502 | SkBitmap bitmap; |
| 503 | // create a bitmap 5 wide and 11 high |
| 504 | bitmap.allocPixels(SkImageInfo::MakeN32Premul(5, 11)); |
| 505 | SkCanvas canvas(bitmap, SkSurfaceProps(0, kUnknown_SkPixelGeometry)); |
| 506 | canvas.clear(SK_ColorWHITE); // white is unpremultiplied, in ARGB order |
| 507 | SkPixmap pixmap; // provides guaranteed access to the drawn pixels |
| 508 | if (!canvas.peekPixels(&pixmap)) { |
| 509 | SkDebugf("peekPixels should never fail.\n"); |
| 510 | } |
| 511 | const SkPMColor* pixels = pixmap.addr32(); // points to top left of bitmap |
| 512 | SkPMColor pmWhite = pixels[0]; // the premultiplied format may vary |
| 513 | SkPaint paint; // by default, draws black, 12 point text |
| 514 | canvas.drawString("!", 1, 10, paint); // 1 char at baseline (1, 10) |
| 515 | for (int y = 0; y < bitmap.height(); ++y) { |
| 516 | for (int x = 0; x < bitmap.width(); ++x) { |
| 517 | SkDebugf("%c", *pixels++ == pmWhite ? '-' : 'x'); |
| 518 | } |
| 519 | SkDebugf("\n"); |
| 520 | } |
| 521 | |
| 522 | #StdOut |
| 523 | ----- |
| 524 | ---x- |
| 525 | ---x- |
| 526 | ---x- |
| 527 | ---x- |
| 528 | ---x- |
| 529 | ---x- |
| 530 | ----- |
| 531 | ---x- |
| 532 | ---x- |
| 533 | ----- |
| 534 | #StdOut ## |
| 535 | ## |
| 536 | |
| 537 | #ToDo incomplete ## |
| 538 | |
| 539 | ## |
| 540 | |
| 541 | # ------------------------------------------------------------------------------ |
| 542 | |
| 543 | #Method virtual ~SkCanvas() |
| 544 | |
| 545 | Draws State_Stack_Layer, if any. |
| 546 | Free up resources used by Canvas. |
| 547 | |
| 548 | #Example |
| 549 | #Error "Haven't thought of a useful example to put here." |
| 550 | ## |
| 551 | |
| 552 | #ToDo create example to show how draw happens when canvas goes out of scope ## |
| 553 | |
| 554 | ## |
| 555 | |
| 556 | # ------------------------------------------------------------------------------ |
| 557 | |
| 558 | #Method SkMetaData& getMetaData() |
| 559 | |
| 560 | Associates additional data with the canvas. |
| 561 | The storage is freed when Canvas is deleted. |
| 562 | |
| 563 | #Return storage that can be read from and written to. ## |
| 564 | |
| 565 | #Example |
| 566 | const char* kHelloMetaData = "HelloMetaData"; |
| 567 | SkCanvas canvas; |
| 568 | SkMetaData& metaData = canvas.getMetaData(); |
| 569 | SkDebugf("before: %s\n", metaData.findString(kHelloMetaData)); |
| 570 | metaData.setString(kHelloMetaData, "Hello!"); |
| 571 | SkDebugf("during: %s\n", metaData.findString(kHelloMetaData)); |
| 572 | metaData.removeString(kHelloMetaData); |
| 573 | SkDebugf("after: %s\n", metaData.findString(kHelloMetaData)); |
| 574 | |
| 575 | #StdOut |
| 576 | before: (null) |
| 577 | during: Hello! |
| 578 | after: (null) |
| 579 | #StdOut ## |
| 580 | ## |
| 581 | |
| 582 | #ToDo incomplete ## |
| 583 | |
| 584 | ## |
| 585 | |
| 586 | # ------------------------------------------------------------------------------ |
| 587 | |
| 588 | #Method SkImageInfo imageInfo() const |
| 589 | |
| 590 | Returns Image_Info for Canvas. If Canvas is not associated with Raster_Surface or |
| 591 | GPU_Surface, returns SkImageInfo::SkImageInfo() is returned Image_Color_Type is set to kUnknown_SkColorType. |
| 592 | |
| 593 | #Return dimensions and Image_Color_Type of Canvas. ## |
| 594 | |
| 595 | #Example |
| 596 | SkCanvas canvas; |
| 597 | SkImageInfo canvasInfo = canvas.imageInfo(); |
| 598 | SkImageInfo emptyInfo; |
| 599 | SkDebugf("emptyInfo %c= canvasInfo\n", emptyInfo == canvasInfo ? '=' : '!'); |
| 600 | ## |
| 601 | |
| 602 | #ToDo incomplete ## |
| 603 | |
| 604 | ## |
| 605 | |
| 606 | # ------------------------------------------------------------------------------ |
| 607 | |
| 608 | #Method bool getProps(SkSurfaceProps* props) const |
| 609 | |
| 610 | If Canvas is associated with Raster_Surface or |
| 611 | GPU_Surface, copies Surface_Properties and returns true. Otherwise, |
| 612 | return false and leave props unchanged. |
| 613 | |
| 614 | #Param props Pointer to writable SkSurfaceProps. ## |
| 615 | |
| 616 | #Return true if Surface_Properties was copied. ## |
| 617 | |
| 618 | #ToDo This seems old style. Deprecate? ## |
| 619 | |
| 620 | #Example |
| 621 | SkBitmap bitmap; |
| 622 | SkCanvas canvas(bitmap, SkSurfaceProps(0, kRGB_V_SkPixelGeometry)); |
| 623 | SkSurfaceProps surfaceProps(0, kUnknown_SkPixelGeometry); |
| 624 | SkDebugf("isRGB:%d\n", SkPixelGeometryIsRGB(surfaceProps.pixelGeometry())); |
| 625 | if (!canvas.getProps(&surfaceProps)) { |
| 626 | SkDebugf("getProps failed unexpectedly.\n"); |
| 627 | } |
| 628 | SkDebugf("isRGB:%d\n", SkPixelGeometryIsRGB(surfaceProps.pixelGeometry())); |
| 629 | |
| 630 | #StdOut |
| 631 | isRGB:0 |
| 632 | isRGB:1 |
| 633 | #StdOut ## |
| 634 | ## |
| 635 | |
| 636 | #ToDo incomplete ## |
| 637 | |
| 638 | ## |
| 639 | |
| 640 | # ------------------------------------------------------------------------------ |
| 641 | |
| 642 | #Method void flush() |
| 643 | |
| 644 | Triggers the immediate execution of all pending draw operations. |
| 645 | If Canvas is associated with GPU_Surface, resolve all pending GPU operations. |
| 646 | |
| 647 | #Example |
| 648 | #Error "haven't thought of a useful example to put here" |
| 649 | ## |
| 650 | |
| 651 | #ToDo incomplete ## |
| 652 | |
| 653 | ## |
| 654 | |
| 655 | # ------------------------------------------------------------------------------ |
| 656 | |
| 657 | #Method virtual SkISize getBaseLayerSize() const |
| 658 | |
| 659 | Gets the size of the base or root layer in global canvas coordinates. The |
| 660 | origin of the base layer is always (0,0). The current drawable area may be |
| 661 | smaller (due to clipping or saveLayer). |
| 662 | |
| 663 | #Return Integral width and height of base layer. ## |
| 664 | |
| 665 | #Example |
| 666 | SkBitmap bitmap; |
| 667 | bitmap.allocPixels(SkImageInfo::MakeN32Premul(20, 30)); |
| 668 | SkCanvas canvas(bitmap, SkSurfaceProps(0, kUnknown_SkPixelGeometry)); |
| 669 | canvas.clipRect(SkRect::MakeWH(10, 40)); |
| 670 | SkIRect clipDeviceBounds = canvas.getDeviceClipBounds(); |
| 671 | if (clipDeviceBounds.isEmpty()) { |
| 672 | SkDebugf("Empty clip bounds is unexpected!\n"); |
| 673 | } |
| 674 | SkDebugf("clip=%d,%d\n", clipDeviceBounds.width(), clipDeviceBounds.height()); |
| 675 | SkISize baseLayerSize = canvas.getBaseLayerSize(); |
| 676 | SkDebugf("size=%d,%d\n", baseLayerSize.width(), baseLayerSize.height()); |
| 677 | |
| 678 | #StdOut |
| 679 | clip=10,30 |
| 680 | size=20,30 |
| 681 | ## |
| 682 | ## |
| 683 | |
| 684 | #ToDo is this the same as the width and height of surface? ## |
| 685 | |
| 686 | ## |
| 687 | |
| 688 | # ------------------------------------------------------------------------------ |
| 689 | |
| 690 | #Method sk_sp<SkSurface> makeSurface(const SkImageInfo& info, const SkSurfaceProps* props = nullptr) |
| 691 | |
| 692 | Creates Surface matching info and props, and associates it with Canvas. |
| 693 | If Canvas is already associated with Surface, it cannot create a new Surface. |
| 694 | |
| 695 | #Param info Initialize Surface with width, height, Image_Color_Type, Image_Alpha_Type, and Color_Space. ## |
| 696 | #Param props Use to match if provided, or use the Surface_Properties in Canvas otherwise. ## |
| 697 | |
| 698 | #Return Surface matching info and props, or nullptr if no match is available. ## |
| 699 | |
| 700 | #Example |
| 701 | sk_sp<SkSurface> surface = SkSurface::MakeRasterN32Premul(5, 6); |
| 702 | SkCanvas* smallCanvas = surface->getCanvas(); |
| 703 | SkImageInfo imageInfo = SkImageInfo::MakeN32Premul(3, 4); |
| 704 | sk_sp<SkSurface> compatible = smallCanvas->makeSurface(imageInfo); |
| 705 | SkDebugf("compatible %c= nullptr\n", compatible == nullptr ? '=' : '!'); |
| 706 | SkDebugf("size = %d, %d\n", compatible->width(), compatible->height()); |
| 707 | |
| 708 | #StdOut |
| 709 | compatible != nullptr
|
| 710 | size = 3, 4 |
| 711 | ## |
| 712 | ## |
| 713 | |
| 714 | #ToDo incomplete ## |
| 715 | |
| 716 | ## |
| 717 | |
| 718 | # ------------------------------------------------------------------------------ |
| 719 | |
| 720 | #Method virtual GrContext* getGrContext() |
| 721 | |
| 722 | Returns GPU_Context of the GPU_Surface associated with Canvas. |
| 723 | |
| 724 | #Return GPU_Context, if available; nullptr otherwise. ## |
| 725 | |
| 726 | #Example |
| 727 | void draw(SkCanvas* canvas) { |
| 728 | if (canvas->getGrContext()) { |
| 729 | canvas->clear(SK_ColorRED); |
| 730 | } else { |
| 731 | canvas->clear(SK_ColorBLUE); |
| 732 | } |
| 733 | } |
| 734 | ## |
| 735 | |
| 736 | #ToDo fiddle should show both CPU and GPU out ## |
| 737 | |
| 738 | ## |
| 739 | |
| 740 | # ------------------------------------------------------------------------------ |
| 741 | |
| 742 | #Method void* accessTopLayerPixels(SkImageInfo* info, size_t* rowBytes, SkIPoint* origin = NULL) |
| 743 | |
| 744 | Returns the pixel base address, Image_Info, rowBytes, and origin if the pixels |
| 745 | can be read directly. |
| 746 | The returned address is only valid |
| 747 | while Canvas is in scope and unchanged. Any Canvas call or Surface call |
| 748 | may invalidate the returned address and other returned values. |
| 749 | |
| 750 | If pixels are inaccessible, info, rowBytes, and origin are unchanged. |
| 751 | |
| 752 | #Param info If not nullptr, copies writable pixels' Image_Info. ## |
| 753 | #Param rowBytes If not nullptr, copies writable pixels' row bytes. ## |
| 754 | #Param origin If not nullptr, copies Canvas top layer origin, its top left corner. ## |
| 755 | |
| 756 | #Return Address of pixels, or nullptr if inaccessible. ## |
| 757 | |
| 758 | #Example |
| 759 | void draw(SkCanvas* canvas) { |
| 760 | if (canvas->accessTopLayerPixels(nullptr, nullptr)) { |
| 761 | canvas->clear(SK_ColorRED); |
| 762 | } else { |
| 763 | canvas->clear(SK_ColorBLUE); |
| 764 | } |
| 765 | } |
| 766 | ## |
| 767 | |
| 768 | #Example |
| 769 | #Description |
| 770 | Draws "ABC" on the device. Then draws "DEF" in an offscreen layer, and reads the |
| 771 | offscreen to add a large dotted "DEF". Finally blends the offscreen with the |
| 772 | device. |
| 773 | |
| 774 | The offscreen and blended result appear on the CPU and GPU but the large dotted |
| 775 | "DEF" appear only on the CPU. |
| 776 | ## |
| 777 | void draw(SkCanvas* canvas) { |
| 778 | SkPaint paint;
|
| 779 | paint.setTextSize(100);
|
| 780 | canvas->drawString("ABC", 20, 160, paint);
|
| 781 | SkRect layerBounds = SkRect::MakeXYWH(32, 32, 192, 192);
|
| 782 | canvas->saveLayerAlpha(&layerBounds, 128);
|
| 783 | canvas->clear(SK_ColorWHITE);
|
| 784 | canvas->drawString("DEF", 20, 160, paint);
|
| 785 | SkImageInfo imageInfo;
|
| 786 | size_t rowBytes;
|
| 787 | SkIPoint origin;
|
| 788 | uint32_t* access = (uint32_t*) canvas->accessTopLayerPixels(&imageInfo, &rowBytes, &origin);
|
| 789 | if (access) {
|
| 790 | int h = imageInfo.height();
|
| 791 | int v = imageInfo.width();
|
| 792 | int rowWords = rowBytes / sizeof(uint32_t);
|
| 793 | for (int y = 0; y < h; ++y) {
|
| 794 | int newY = (y - h / 2) * 2 + h / 2;
|
| 795 | if (newY < 0 || newY >= h) {
|
| 796 | continue;
|
| 797 | }
|
| 798 | for (int x = 0; x < v; ++x) {
|
| 799 | int newX = (x - v / 2) * 2 + v / 2;
|
| 800 | if (newX < 0 || newX >= v) {
|
| 801 | continue;
|
| 802 | }
|
| 803 | if (access[y * rowWords + x] == SK_ColorBLACK) {
|
| 804 | access[newY * rowWords + newX] = SK_ColorGRAY;
|
| 805 | }
|
| 806 | }
|
| 807 | }
|
| 808 |
|
| 809 | }
|
| 810 | canvas->restore(); |
| 811 | } |
| 812 | ## |
| 813 | |
| 814 | #ToDo there are no callers of this that I can find. Deprecate? ## |
| 815 | #ToDo fiddle should show both CPU and GPU out ## |
| 816 | |
| 817 | ## |
| 818 | |
| 819 | # ------------------------------------------------------------------------------ |
| 820 | |
| 821 | #Method SkRasterHandleAllocator::Handle accessTopRasterHandle() const |
| 822 | |
| 823 | Returns custom context that tracks the Matrix and Clip. |
| 824 | |
| 825 | Use Raster_Handle_Allocator to blend Skia drawing with custom drawing, typically performed |
| 826 | by the host platform's user interface. This accessor returns the custom context created |
| 827 | when SkRasterHandleAllocator::MakeCanvas creates a custom canvas with raster storage for |
| 828 | the drawing destination. |
| 829 | |
| 830 | #Return Context of custom allocator. ## |
| 831 | |
| 832 | #Example |
| 833 | #Description |
| 834 | #ToDo ## |
| 835 | ## |
| 836 | #Function |
| 837 | static void DeleteCallback(void*, void* context) { |
| 838 | delete (char*) context; |
| 839 | } |
| 840 | |
| 841 | class CustomAllocator : public SkRasterHandleAllocator { |
| 842 | public: |
| 843 | bool allocHandle(const SkImageInfo& info, Rec* rec) override { |
| 844 | char* context = new char[4]{'s', 'k', 'i', 'a'}; |
| 845 | rec->fReleaseProc = DeleteCallback; |
| 846 | rec->fReleaseCtx = context; |
| 847 | rec->fHandle = context; |
| 848 | rec->fPixels = context; |
| 849 | rec->fRowBytes = 4; |
| 850 | return true; |
| 851 | } |
| 852 | |
| 853 | void updateHandle(Handle handle, const SkMatrix& ctm, const SkIRect& clip_bounds) override { |
| 854 | // apply canvas matrix and clip to custom environment |
| 855 | } |
| 856 | }; |
| 857 | |
| 858 | ## |
| 859 | void draw(SkCanvas* canvas) { |
| 860 | const SkImageInfo info = SkImageInfo::MakeN32Premul(1, 1); |
| 861 | std::unique_ptr<SkCanvas> c2 = |
| 862 | SkRasterHandleAllocator::MakeCanvas(std::unique_ptr<CustomAllocator>( |
| 863 | new CustomAllocator()), info); |
| 864 | char* context = (char*) c2->accessTopRasterHandle(); |
| 865 | SkDebugf("context = %.4s\n", context); |
| 866 | |
| 867 | } |
| 868 | #StdOut |
| 869 | context = skia |
| 870 | ## |
| 871 | #ToDo skstd::make_unique could not be used because def is private -- note to fix in c++14? ## |
| 872 | ## |
| 873 | |
| 874 | #SeeAlso SkRasterHandleAllocator |
| 875 | |
| 876 | ## |
| 877 | |
| 878 | # ------------------------------------------------------------------------------ |
| 879 | |
| 880 | #Method bool peekPixels(SkPixmap* pixmap) |
| 881 | |
| 882 | Returns true if Canvas has direct access to its pixels. |
| 883 | |
| 884 | Pixels are readable when Device is raster. Pixels are not readable when SkCanvas is returned from |
| 885 | GPU_Surface, returned by SkDocument::beginPage, returned by SkPictureRecorder::beginRecording, |
| 886 | or SkCanvas is the base of a utility class like SkDumpCanvas. |
| 887 | |
| 888 | pixmap pixel address is only valid while Canvas is in scope and unchanged. Any Canvas or Surface call may |
| 889 | invalidate the pixmap values. |
| 890 | |
| 891 | #Param pixmap storage for Canvas pixel state if Canvas pixels are readable; otherwise, ignored. ## |
| 892 | |
| 893 | #Return true if Canvas has direct access to pixels. ## |
| 894 | |
| 895 | #Example |
| 896 | SkPixmap pixmap; |
| 897 | if (canvas->peekPixels(&pixmap)) { |
| 898 | SkDebugf("width=%d height=%d\n", pixmap.bounds().width(), pixmap.bounds().height()); |
| 899 | } |
| 900 | #StdOut |
| 901 | width=256 height=256 |
| 902 | ## |
| 903 | ## |
| 904 | |
| 905 | ## |
| 906 | |
| 907 | # ------------------------------------------------------------------------------ |
| 908 | |
| 909 | #Method bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes, |
| 910 | int srcX, int srcY) |
| 911 | |
| 912 | Copies rectangle of pixels from Canvas into dstPixels, converting their Image_Color_Type and Image_Alpha_Type. |
| 913 | Pixels are readable when Device is raster. Pixels are not readable when SkCanvas is returned from |
| 914 | GPU_Surface, returned by SkDocument::beginPage, returned by SkPictureRecorder::beginRecording, |
| 915 | or SkCanvas is the base of a utility class like SkDumpCanvas. |
| 916 | |
| 917 | Pixel values are converted only if Canvas Image_Color_Type and Image_Alpha_Type does not match dstInfo. |
| 918 | Only pixels within the rectangle that intersect Canvas pixels are copied. |
| 919 | dstPixels outside the rectangle intersection are unchanged. |
| 920 | |
| 921 | #Table |
| 922 | #Legend |
| 923 | # source rectangle # value ## |
| 924 | ## |
| 925 | # left # srcX ## |
| 926 | # top # srcY ## |
| 927 | # width # dstInfo.width() ## |
| 928 | # height # dstInfo.height() ## |
| 929 | ## |
| 930 | |
| 931 | #Table |
| 932 | #Legend |
| 933 | # canvas pixel bounds # value ## |
| 934 | ## |
| 935 | # left # 0 ## |
| 936 | # top # 0 ## |
| 937 | # width # imageInfo().width() ## |
| 938 | # height # imageInfo().height() ## |
| 939 | ## |
| 940 | |
| 941 | Does not copy, and returns false if: |
| 942 | |
| 943 | #List |
| 944 | # Source rectangle and canvas pixel bounds do not intersect. ## |
| 945 | # Canvas pixels could not be converted to dstInfo Image_Color_Type or dstInfo Image_Alpha_Type. ## |
| 946 | # Canvas pixels are not readable; for instance, Canvas is not raster, or is document-based. ## |
| 947 | # dstRowBytes is too small to contain one row of pixels. ## |
| 948 | ## |
| 949 | |
| 950 | #Param dstInfo Dimensions, Image_Color_Type, and Image_Alpha_Type of dstPixels. ## |
| 951 | #Param dstPixels Storage for pixels, of size dstInfo.height() times dstRowBytes. ## |
| 952 | #Param dstRowBytes Size of one destination row, dstInfo.width() times pixel size. ## |
| 953 | #Param srcX Offset into readable pixels in x. ## |
| 954 | #Param srcY Offset into readable pixels in y. ## |
| 955 | |
| 956 | #Return true if pixels were copied. ## |
| 957 | |
| 958 | #Example |
| 959 | #Description |
| 960 | Canvas returned by Raster_Surface has premultiplied pixel values. |
| 961 | clear() takes unpremultiplied input with Color_Alpha equal 0x80 |
| 962 | and Color_RGB equal 0x55, 0xAA, 0xFF. Color_RGB is multipled by Color_Alpha |
| 963 | to generate premultipled value 0x802B5580. readPixels converts pixel back |
| 964 | to unpremultipled value 0x8056A9FF, introducing error. |
| 965 | ## |
| 966 | canvas->clear(0x8055aaff); |
| 967 | for (SkAlphaType alphaType : { kPremul_SkAlphaType, kUnpremul_SkAlphaType } ) { |
| 968 | uint32_t pixel = 0; |
| 969 | SkImageInfo info = SkImageInfo::Make(1, 1, kBGRA_8888_SkColorType, alphaType); |
| 970 | if (canvas->readPixels(info, &pixel, 4, 0, 0)) { |
| 971 | SkDebugf("pixel = %08x\n", pixel); |
| 972 | } |
| 973 | } |
| 974 | |
| 975 | #StdOut |
| 976 | pixel = 802b5580 |
| 977 | pixel = 8056a9ff |
| 978 | ## |
| 979 | ## |
| 980 | |
| 981 | #ToDo incomplete ## |
| 982 | |
| 983 | ## |
| 984 | |
| 985 | # ------------------------------------------------------------------------------ |
| 986 | |
| 987 | #Method bool readPixels(const SkPixmap& pixmap, int srcX, int srcY) |
| 988 | |
| 989 | Copies rectangle of pixels from Canvas into Pixmap, converting their Image_Color_Type and Image_Alpha_Type. |
| 990 | Pixels are readable when Device is raster. Pixels are not readable when SkCanvas is returned from |
| 991 | GPU_Surface, returned by SkDocument::beginPage, returned by SkPictureRecorder::beginRecording, |
| 992 | or SkCanvas is the base of a utility class like SkDumpCanvas. |
| 993 | |
| 994 | Pixel values are converted only if Canvas Image_Color_Type and Image_Alpha_Type does not match bitmap Image_Info. |
| 995 | Only Pixmap pixels within the rectangle that intersect Canvas pixels are copied. |
| 996 | Pixmap pixels outside the rectangle intersection are unchanged. |
| 997 | |
| 998 | #Table |
| 999 | #Legend |
| 1000 | # source rectangle # value ## |
| 1001 | ## |
| 1002 | # left # srcX ## |
| 1003 | # top # srcY ## |
| 1004 | # width # bitmap.width() ## |
| 1005 | # height # bitmap.height() ## |
| 1006 | ## |
| 1007 | |
| 1008 | #Table |
| 1009 | #Legend |
| 1010 | # canvas pixel bounds # value ## |
| 1011 | ## |
| 1012 | # left # 0 ## |
| 1013 | # top # 0 ## |
| 1014 | # width # imageInfo().width() ## |
| 1015 | # height # imageInfo().height() ## |
| 1016 | ## |
| 1017 | |
| 1018 | Does not copy, and returns false if: |
| 1019 | |
| 1020 | #List |
| 1021 | # Source rectangle and canvas pixel bounds do not intersect. ## |
| 1022 | # Canvas pixels could not be converted to bitmap Image_Color_Type or bitmap Image_Alpha_Type. ## |
| 1023 | # Canvas pixels are not readable; for instance, Canvas is not raster, or is document-based. ## |
| 1024 | # bitmap pixels could not be allocated. ## |
| 1025 | # Bitmap_Row_Bytes is too small to contain one row of pixels. ## |
| 1026 | ## |
| 1027 | |
| 1028 | #Param pixmap Receives pixels copied from Canvas. ## |
| 1029 | #Param srcX Offset into readable pixels in x. ## |
| 1030 | #Param srcY Offset into readable pixels in y. ## |
| 1031 | |
| 1032 | #Return true if pixels were copied. ## |
| 1033 | |
| 1034 | #Example |
| 1035 | void draw(SkCanvas* canvas) { |
| 1036 | canvas->clear(0x8055aaff); |
| 1037 | uint32_t pixels[1] = { 0 }; |
| 1038 | SkPixmap pixmap(SkImageInfo::MakeN32Premul(1, 1), pixels, 4);
|
| 1039 | canvas->readPixels(pixmap, 0, 0); |
| 1040 | SkDebugf("pixel = %08x\n", pixels[0]); |
| 1041 | } |
| 1042 | #StdOut |
| 1043 | pixel = 802b5580 |
| 1044 | ## |
| 1045 | ## |
| 1046 | |
| 1047 | #ToDo incomplete ## |
| 1048 | |
| 1049 | ## |
| 1050 | |
| 1051 | # ------------------------------------------------------------------------------ |
| 1052 | |
| 1053 | #Method bool readPixels(const SkBitmap& bitmap, int srcX, int srcY) |
| 1054 | |
| 1055 | Copies pixels enclosed by bitmap offset to (x, y) from Canvas into bitmap, converting their Image_Color_Type and Image_Alpha_Type. |
| 1056 | Pixels are readable when Device is raster. Pixels are not readable when SkCanvas is returned from |
| 1057 | GPU_Surface, returned by SkDocument::beginPage, returned by SkPictureRecorder::beginRecording, |
| 1058 | or SkCanvas is the base of a utility class like SkDumpCanvas. |
| 1059 | Allocates pixel storage in bitmap if needed. |
| 1060 | |
| 1061 | Pixel values are converted only if Canvas Image_Color_Type and Image_Alpha_Type does not match bitmap Image_Info. |
| 1062 | Only pixels within the rectangle that intersect Canvas pixels are copied. |
| 1063 | Bitamp pixels outside the rectangle intersection are unchanged. |
| 1064 | |
| 1065 | #Table |
| 1066 | #Legend |
| 1067 | # canvas pixel bounds # value ## |
| 1068 | ## |
| 1069 | # left # 0 ## |
| 1070 | # top # 0 ## |
| 1071 | # width # imageInfo().width() ## |
| 1072 | # height # imageInfo().height() ## |
| 1073 | ## |
| 1074 | |
| 1075 | Does not copy, and returns false if: |
| 1076 | |
| 1077 | #List |
| 1078 | # Bounds formed by (x, y) and bitmap (width, height) and canvas pixel bounds do not intersect. ## |
| 1079 | # Canvas pixels could not be converted to bitmap Image_Color_Type or bitmap Image_Alpha_Type. ## |
| 1080 | # Canvas pixels are not readable; for instance, Canvas is not raster, or is document-based. ## |
| 1081 | # bitmap pixels could not be allocated. ## |
| 1082 | # Bitmap_Row_Bytes is too small to contain one row of pixels. ## |
| 1083 | ## |
| 1084 | |
| 1085 | #Param bitmap Receives pixels copied from Canvas. ## |
| 1086 | #Param srcX Offset into readable pixels in x. ## |
| 1087 | #Param srcY Offset into readable pixels in y. ## |
| 1088 | |
| 1089 | #Return true if pixels were copied. ## |
| 1090 | |
| 1091 | #Example |
| 1092 | void draw(SkCanvas* canvas) { |
| 1093 | canvas->clear(0x8055aaff); |
| 1094 | SkBitmap bitmap; |
| 1095 | bitmap.allocPixels(SkImageInfo::MakeN32Premul(1, 1)); |
| 1096 | canvas->readPixels(bitmap, 0, 0); |
| 1097 | SkDebugf("pixel = %08x\n", bitmap.getAddr32(0, 0)[0]); |
| 1098 | } |
| 1099 | #StdOut |
| 1100 | pixel = 802b5580 |
| 1101 | ## |
| 1102 | ## |
| 1103 | |
| 1104 | #ToDo incomplete ## |
| 1105 | |
| 1106 | ## |
| 1107 | |
| 1108 | # ------------------------------------------------------------------------------ |
| 1109 | |
| 1110 | #Method bool writePixels(const SkImageInfo& info, const void* pixels, size_t rowBytes, int x, int y) |
| 1111 | |
| 1112 | Copies to Canvas pixels, ignoring the Matrix and Clip, converting to match |
| 1113 | info Image_Color_Type and info Image_Alpha_Type. |
| 1114 | |
| 1115 | Pixel values are converted only if Canvas Image_Color_Type and Image_Alpha_Type does not match info. |
| 1116 | Only pixels within the source rectangle that intersect Canvas pixel bounds are copied. |
| 1117 | Canvas pixels outside the rectangle intersection are unchanged. |
| 1118 | |
| 1119 | #Table |
| 1120 | #Legend |
| 1121 | # source rectangle # value ## |
| 1122 | ## |
| 1123 | # left # x ## |
| 1124 | # top # y ## |
| 1125 | # width # info.width() ## |
| 1126 | # height # info.height() ## |
| 1127 | ## |
| 1128 | |
| 1129 | #Table |
| 1130 | #Legend |
| 1131 | # canvas pixel bounds # value ## |
| 1132 | ## |
| 1133 | # left # 0 ## |
| 1134 | # top # 0 ## |
| 1135 | # width # imageInfo().width() ## |
| 1136 | # height # imageInfo().height() ## |
| 1137 | ## |
| 1138 | |
| 1139 | Does not copy, and returns false if: |
| 1140 | |
| 1141 | #List |
| 1142 | # Source rectangle and canvas pixel bounds do not intersect. ## |
| 1143 | # pixels could not be converted to Canvas Image_Color_Type or Canvas Image_Alpha_Type. ## |
| 1144 | # Canvas pixels are not writable; for instance, Canvas is document-based. ## |
| 1145 | # rowBytes is too small to contain one row of pixels. ## |
| 1146 | ## |
| 1147 | |
| 1148 | #Param info Dimensions, Image_Color_Type, and Image_Alpha_Type of pixels. ## |
| 1149 | #Param pixels Pixels to copy, of size info.height() times rowBytes. ## |
| 1150 | #Param rowBytes Offset from one row to the next, usually info.width() times pixel size. ## |
| 1151 | #Param x Offset into Canvas writable pixels in x. ## |
| 1152 | #Param y Offset into Canvas writable pixels in y. ## |
| 1153 | |
| 1154 | #Return true if pixels were written to Canvas. ## |
| 1155 | |
| 1156 | #Example |
| 1157 | SkImageInfo imageInfo = SkImageInfo::MakeN32(256, 1, kPremul_SkAlphaType); |
| 1158 | for (int y = 0; y < 256; ++y) { |
| 1159 | uint32_t pixels[256]; |
| 1160 | for (int x = 0; x < 256; ++x) { |
| 1161 | pixels[x] = SkColorSetARGB(x, x + y, x, x - y); |
| 1162 | } |
| 1163 | canvas->writePixels(imageInfo, &pixels, sizeof(pixels), 0, y); |
| 1164 | } |
| 1165 | ## |
| 1166 | |
| 1167 | #ToDo incomplete ## |
| 1168 | |
| 1169 | ## |
| 1170 | |
| 1171 | # ------------------------------------------------------------------------------ |
| 1172 | |
| 1173 | #Method bool writePixels(const SkBitmap& bitmap, int x, int y) |
| 1174 | |
| 1175 | Writes to Canvas pixels, ignoring the Matrix and Clip, converting to match |
| 1176 | bitmap Image_Color_Type and bitmap Image_Alpha_Type. |
| 1177 | |
| 1178 | Pixel values are converted only if Canvas Image_Color_Type and Image_Alpha_Type does not match bitmap. |
| 1179 | Only pixels within the source rectangle that intersect Canvas pixel bounds are copied. |
| 1180 | Canvas pixels outside the rectangle intersection are unchanged. |
| 1181 | |
| 1182 | #Table |
| 1183 | #Legend |
| 1184 | # source rectangle # value ## |
| 1185 | ## |
| 1186 | # left # x ## |
| 1187 | # top # y ## |
| 1188 | # width # bitmap.width() ## |
| 1189 | # height # bitmap.height() ## |
| 1190 | ## |
| 1191 | |
| 1192 | #Table |
| 1193 | #Legend |
| 1194 | # canvas pixel bounds # value ## |
| 1195 | ## |
| 1196 | # left # 0 ## |
| 1197 | # top # 0 ## |
| 1198 | # width # imageInfo().width() ## |
| 1199 | # height # imageInfo().height() ## |
| 1200 | ## |
| 1201 | |
| 1202 | Does not copy, and returns false if: |
| 1203 | |
| 1204 | #List |
| 1205 | # Source rectangle and Canvas pixel bounds do not intersect. ## |
| 1206 | # bitmap does not have allocated pixels. ## |
| 1207 | # bitmap pixels could not be converted to Canvas Image_Color_Type or Canvas Image_Alpha_Type. ## |
| 1208 | # Canvas pixels are not writable; for instance, Canvas is document-based. ## |
| 1209 | # bitmap pixels are inaccessible; for instance, bitmap wraps a texture. ## |
| 1210 | ## |
| 1211 | |
| 1212 | #Param bitmap Provides pixels copied to Canvas. ## |
| 1213 | #Param x Offset into Canvas writable pixels in x. ## |
| 1214 | #Param y Offset into Canvas writable pixels in y. ## |
| 1215 | |
| 1216 | #Return true if pixels were written to Canvas. ## |
| 1217 | |
| 1218 | #Example |
| 1219 | void draw(SkCanvas* canvas) { |
| 1220 | SkImageInfo imageInfo = SkImageInfo::MakeN32Premul(2, 2); |
| 1221 | SkBitmap bitmap; |
| 1222 | bitmap.setInfo(imageInfo); |
| 1223 | uint32_t pixels[4]; |
| 1224 | bitmap.setPixels(pixels); |
| 1225 | for (int y = 0; y < 256; y += 2) { |
| 1226 | for (int x = 0; x < 256; x += 2) { |
| 1227 | pixels[0] = SkColorSetRGB(x, y, x | y); |
| 1228 | pixels[1] = SkColorSetRGB(x ^ y, y, x); |
| 1229 | pixels[2] = SkColorSetRGB(x, x & y, y); |
| 1230 | pixels[3] = SkColorSetRGB(~x, ~y, x); |
| 1231 | canvas->writePixels(bitmap, x, y); |
| 1232 | } |
| 1233 | } |
| 1234 | } |
| 1235 | ## |
| 1236 | |
| 1237 | #ToDo incomplete ## |
| 1238 | |
| 1239 | ## |
| 1240 | |
| 1241 | # ------------------------------------------------------------------------------ |
| 1242 | #Topic State_Stack |
| 1243 | |
| 1244 | Canvas maintains a stack of state that allows hierarchical drawing, commonly used |
| 1245 | to implement windows and views. The initial state has an identity matrix and and an infinite clip. |
| 1246 | Even with a wide-open clip, drawing is constrained by the bounds of the |
| 1247 | Canvas Surface or Device. |
| 1248 | |
| 1249 | Canvas savable state consists of Clip, Matrix, and Draw_Filter. |
| 1250 | Clip describes the area that may be drawn to. |
| 1251 | Matrix transforms the geometry. |
| 1252 | Draw_Filter (deprecated on most platforms) modifies the paint before drawing. |
| 1253 | |
| 1254 | save(), saveLayer, saveLayerPreserveLCDTextRequests, and saveLayerAlpha |
| 1255 | save state and return the depth of the stack. |
| 1256 | |
| 1257 | restore() and restoreToCount revert state to its value when saved. |
| 1258 | |
| 1259 | Each state on the stack intersects Clip with the previous Clip, |
| 1260 | and concatenates Matrix with the previous Matrix. |
| 1261 | The intersected Clip makes the drawing area the same or smaller; |
| 1262 | the concatenated Matrix may move the origin and potentially scale or rotate |
| 1263 | the coordinate space. |
| 1264 | |
| 1265 | Canvas does not require balancing the state stack but it is a good idea |
| 1266 | to do so. Calling save() without restore() will eventually cause Skia to fail; |
| 1267 | mismatched save() and restore() create hard to find bugs. |
| 1268 | |
| 1269 | It is not possible to use state to draw outside of the clip defined by the |
| 1270 | previous state. |
| 1271 | |
| 1272 | #Example |
| 1273 | #Description |
| 1274 | Draw to ever smaller clips; then restore drawing to full canvas. |
| 1275 | Note that the second clipRect is not permitted to enlarge Clip. |
| 1276 | ## |
| 1277 | #Height 160 |
| 1278 | void draw(SkCanvas* canvas) {
|
| 1279 | SkPaint paint;
|
| 1280 | canvas->save(); // records stack depth to restore
|
| 1281 | canvas->clipRect(SkRect::MakeWH(100, 100)); // constrains drawing to clip
|
| 1282 | canvas->clear(SK_ColorRED); // draws to limit of clip
|
| 1283 | canvas->save(); // records stack depth to restore
|
| 1284 | canvas->clipRect(SkRect::MakeWH(50, 150)); // Rect below 100 is ignored
|
| 1285 | canvas->clear(SK_ColorBLUE); // draws to smaller clip
|
| 1286 | canvas->restore(); // enlarges clip
|
| 1287 | canvas->drawLine(20, 20, 150, 150, paint); // line below 100 is not drawn
|
| 1288 | canvas->restore(); // enlarges clip
|
| 1289 | canvas->drawLine(150, 20, 50, 120, paint); // line below 100 is drawn
|
| 1290 | } |
| 1291 | ## |
| 1292 | |
| 1293 | Each Clip uses the current Matrix for its coordinates. |
| 1294 | |
| 1295 | #Example |
| 1296 | #Description |
| 1297 | While clipRect is given the same rectangle twice, Matrix makes the second |
| 1298 | clipRect draw at half the size of the first. |
| 1299 | ## |
| 1300 | #Height 128 |
| 1301 | void draw(SkCanvas* canvas) {
|
| 1302 | canvas->clipRect(SkRect::MakeWH(100, 100));
|
| 1303 | canvas->clear(SK_ColorRED);
|
| 1304 | canvas->scale(.5, .5);
|
| 1305 | canvas->clipRect(SkRect::MakeWH(100, 100));
|
| 1306 | canvas->clear(SK_ColorBLUE);
|
| 1307 | } |
| 1308 | ## |
| 1309 | |
| 1310 | #SeeAlso save() saveLayer saveLayerPreserveLCDTextRequests saveLayerAlpha restore() restoreToCount |
| 1311 | |
| 1312 | #Method int save() |
| 1313 | |
| 1314 | Saves Matrix, Clip, and Draw_Filter (Draw_Filter deprecated on most platforms). |
| 1315 | Calling restore() discards changes to Matrix, Clip, and Draw_Filter, |
| 1316 | restoring the Matrix, Clip, and Draw_Filter to their state when save() was called. |
| 1317 | |
| 1318 | Matrix may be changed by translate(), scale(), rotate(), skew(), concat(), setMatrix, and resetMatrix. |
| 1319 | Clip may be changed by clipRect, clipRRect, clipPath, clipRegion. |
| 1320 | |
| 1321 | Saved Canvas state is put on a stack; multiple calls to save() should be balance by an equal number of |
| 1322 | calls to restore(). |
| 1323 | |
| 1324 | Call restoreToCount with result to restore this and subsequent saves. |
| 1325 | |
| 1326 | #Return Depth of saved stack. ## |
| 1327 | |
| 1328 | #Example |
| 1329 | #Description |
| 1330 | The black square is translated 50 pixels down and to the right. |
| 1331 | Restoring Canvas state removes translate() from Canvas stack; |
| 1332 | the red square is not translated, and is drawn at the origin. |
| 1333 | ## |
| 1334 | #Height 100 |
| 1335 | void draw(SkCanvas* canvas) { |
| 1336 | SkPaint paint; |
| 1337 | SkRect rect = { 0, 0, 25, 25 }; |
| 1338 | canvas->drawRect(rect, paint); |
| 1339 | canvas->save(); |
| 1340 | canvas->translate(50, 50); |
| 1341 | canvas->drawRect(rect, paint); |
| 1342 | canvas->restore(); |
| 1343 | paint.setColor(SK_ColorRED); |
| 1344 | canvas->drawRect(rect, paint); |
| 1345 | } |
| 1346 | ## |
| 1347 | |
| 1348 | #ToDo incomplete ## |
| 1349 | |
| 1350 | ## |
| 1351 | |
| 1352 | # ------------------------------------------------------------------------------ |
| 1353 | #Subtopic Layer |
| 1354 | |
| 1355 | Layer allocates a temporary offscreen Bitmap to draw into. When the drawing is complete, |
| 1356 | the Bitmap is drawn into the Canvas. |
| 1357 | |
| 1358 | Layer is saved in a stack along with other saved state. When state with a Layer |
| 1359 | is restored, the offscreen Bitmap is drawn into the previous layer. |
| 1360 | |
| 1361 | Layer may be initialized with the contents of the previous layer. When Layer is |
| 1362 | restored, its Bitmap can be modified by Paint passed to Layer to apply Color_Alpha, |
| 1363 | Color_Filter, Image_Filter, and Blend_Mode. |
| 1364 | |
| 1365 | #Method int saveLayer(const SkRect* bounds, const SkPaint* paint) |
| 1366 | |
| 1367 | Saves Matrix, Clip, and Draw_Filter (Draw_Filter deprecated on most platforms), |
| 1368 | and allocates an offscreen Bitmap for subsequent drawing. |
| 1369 | Calling restore() discards changes to Matrix, Clip, and Draw_Filter, |
| 1370 | and draws the offscreen bitmap. |
| 1371 | The Matrix, Clip, and Draw_Filter are restored to their state when save() was called. |
| 1372 | |
| 1373 | Matrix may be changed by translate(), scale(), rotate(), skew(), concat(), setMatrix, and resetMatrix. |
| 1374 | Clip may be changed by clipRect, clipRRect, clipPath, clipRegion. |
| 1375 | |
| 1376 | Rect bounds suggests but does not define the offscreen size. To clip drawing to a specific rectangle, |
| 1377 | use clipRect. |
| 1378 | |
| 1379 | Optional Paint paint applies Color_Alpha, Color_Filter, Image_Filter, and Blend_Mode when restore() is called. |
| 1380 | |
| 1381 | Call restoreToCount with result to restore this and subsequent saves. |
| 1382 | |
| 1383 | #Param bounds Used as a hint to limit the size of the offscreen; may be nullptr. ## |
| 1384 | #Param paint Used when restore() is called to draw the offscreen; may be nullptr. ## |
| 1385 | |
| 1386 | #Return Depth of saved stack. ## |
| 1387 | |
| 1388 | #Example |
| 1389 | #Description |
| 1390 | Rectangles are blurred by Image_Filter when restore() draws offscreen to main Canvas. |
| 1391 | ## |
| 1392 | #Height 128 |
| 1393 | void draw(SkCanvas* canvas) { |
| 1394 | SkPaint paint, blur; |
| 1395 | blur.setImageFilter(SkImageFilter::MakeBlur(3, 3, nullptr)); |
| 1396 | canvas->saveLayer(nullptr, &blur); |
| 1397 | SkRect rect = { 25, 25, 50, 50}; |
| 1398 | canvas->drawRect(rect, paint); |
| 1399 | canvas->translate(50, 50); |
| 1400 | paint.setColor(SK_ColorRED); |
| 1401 | canvas->drawRect(rect, paint); |
| 1402 | canvas->restore(); |
| 1403 | } |
| 1404 | ## |
| 1405 | |
| 1406 | #ToDo incomplete ## |
| 1407 | |
| 1408 | ## |
| 1409 | |
| 1410 | #Method int saveLayer(const SkRect& bounds, const SkPaint* paint) |
| 1411 | |
| 1412 | Saves Matrix, Clip, and Draw_Filter (Draw_Filter deprecated on most platforms), |
| 1413 | and allocates an offscreen Bitmap for subsequent drawing. |
| 1414 | Calling restore() discards changes to Matrix, Clip, and Draw_Filter, |
| 1415 | and draws the offscreen Bitmap. |
| 1416 | The Matrix, Clip, and Draw_Filter are restored to their state when save() was called. |
| 1417 | |
| 1418 | Matrix may be changed by translate(), scale(), rotate(), skew(), concat(), setMatrix, and resetMatrix. |
| 1419 | Clip may be changed by clipRect, clipRRect, clipPath, clipRegion. |
| 1420 | |
| 1421 | bounds suggests but does not define the offscreen size. To clip drawing to a specific rectangle, |
| 1422 | use clipRect. |
| 1423 | |
| 1424 | Optional Paint paint applies Color_Alpha, Color_Filter, Image_Filter, and Blend_Mode when restore() is called. |
| 1425 | |
| 1426 | Call restoreToCount with result to restore this and subsequent saves. |
| 1427 | |
| 1428 | #Param bounds Used as a hint to limit the size of the offscreen; may be nullptr. ## |
| 1429 | #Param paint Used when restore() is called to draw the offscreen; may be nullptr. ## |
| 1430 | |
| 1431 | #Return Depth of saved stack. ## |
| 1432 | |
| 1433 | #Example |
| 1434 | #Description |
| 1435 | Rectangles are blurred by Image_Filter when restore() draws offscreen to main Canvas. |
| 1436 | The red rectangle is clipped; it does not fully fit on the offscreen Canvas. |
| 1437 | Image_Filter blurs past edge of offscreen so red rectangle is blurred on all sides. |
| 1438 | ## |
| 1439 | #Height 128 |
| 1440 | void draw(SkCanvas* canvas) { |
| 1441 | SkPaint paint, blur; |
| 1442 | blur.setImageFilter(SkImageFilter::MakeBlur(3, 3, nullptr)); |
| 1443 | canvas->saveLayer(SkRect::MakeWH(90, 90), &blur); |
| 1444 | SkRect rect = { 25, 25, 50, 50}; |
| 1445 | canvas->drawRect(rect, paint); |
| 1446 | canvas->translate(50, 50); |
| 1447 | paint.setColor(SK_ColorRED); |
| 1448 | canvas->drawRect(rect, paint); |
| 1449 | canvas->restore(); |
| 1450 | } |
| 1451 | ## |
| 1452 | |
| 1453 | #ToDo incomplete ## |
| 1454 | |
| 1455 | ## |
| 1456 | |
| 1457 | #Method int saveLayerPreserveLCDTextRequests(const SkRect* bounds, const SkPaint* paint) |
| 1458 | |
| 1459 | Saves Matrix, Clip, and Draw_Filter (Draw_Filter deprecated on most platforms), |
| 1460 | and allocates an offscreen bitmap for subsequent drawing. |
| 1461 | LCD_Text is preserved when the offscreen is drawn to the prior layer. |
| 1462 | |
| 1463 | Draw text on an opaque background so that LCD_Text blends correctly with the prior layer. |
| 1464 | |
| 1465 | Calling restore() discards changes to Matrix, Clip, and Draw_Filter, |
| 1466 | and draws the offscreen bitmap. |
| 1467 | The Matrix, Clip, and Draw_Filter are restored to their state when save() was called. |
| 1468 | |
| 1469 | Matrix may be changed by translate(), scale(), rotate(), skew(), concat(), setMatrix, and resetMatrix. |
| 1470 | Clip may be changed by clipRect, clipRRect, clipPath, clipRegion. |
| 1471 | |
| 1472 | Draw LCD_Text on an opaque background to get good results. |
| 1473 | |
| 1474 | bounds suggests but does not define the offscreen size. To clip drawing to a specific rectangle, |
| 1475 | use clipRect. |
| 1476 | |
| 1477 | paint modifies how the offscreen overlays the prior layer. Color_Alpha, Blend_Mode, |
| 1478 | Color_Filter, Draw_Looper, Image_Filter, and Mask_Filter, affect the offscreen draw. |
| 1479 | |
| 1480 | Call restoreToCount with result to restore this and subsequent saves. |
| 1481 | |
| 1482 | #Param bounds Used as a hint to limit the size of the offscreen; may be nullptr. ## |
| 1483 | #Param paint Used when restore() is called to draw the offscreen; may be nullptr. ## |
| 1484 | |
| 1485 | #Return Depth of saved stack. ## |
| 1486 | |
| 1487 | #Example |
| 1488 | SkPaint paint;
|
| 1489 | paint.setAntiAlias(true);
|
| 1490 | paint.setLCDRenderText(true);
|
| 1491 | paint.setTextSize(20);
|
| 1492 | for (auto preserve : { false, true } ) {
|
| 1493 | preserve ? canvas->saveLayerPreserveLCDTextRequests(nullptr, nullptr)
|
| 1494 | : canvas->saveLayer(nullptr, nullptr);
|
| 1495 | SkPaint p;
|
| 1496 | p.setColor(SK_ColorWHITE);
|
| 1497 | // Comment out the next line to draw on a non-opaque background.
|
| 1498 | canvas->drawRect(SkRect::MakeLTRB(25, 40, 200, 70), p);
|
| 1499 | canvas->drawString("Hamburgefons", 30, 60, paint);
|
| 1500 |
|
| 1501 | p.setColor(0xFFCCCCCC);
|
| 1502 | canvas->drawRect(SkRect::MakeLTRB(25, 70, 200, 100), p);
|
| 1503 | canvas->drawString("Hamburgefons", 30, 90, paint);
|
| 1504 |
|
| 1505 | canvas->restore();
|
| 1506 | canvas->translate(0, 80);
|
| 1507 | } |
| 1508 | ## |
| 1509 | |
| 1510 | #ToDo incomplete ## |
| 1511 | |
| 1512 | ## |
| 1513 | |
| 1514 | #Method int saveLayerAlpha(const SkRect* bounds, U8CPU alpha) |
| 1515 | |
| 1516 | Saves Matrix, Clip, and Draw_Filter (Draw_Filter deprecated on most platforms), |
| 1517 | and allocates an offscreen bitmap for subsequent drawing. |
| 1518 | |
| 1519 | Calling restore() discards changes to Matrix, Clip, and Draw_Filter, |
| 1520 | and blends the offscreen bitmap with alpha opacity onto the prior layer. |
| 1521 | The Matrix, Clip, and Draw_Filter are restored to their state when save() was called. |
| 1522 | |
| 1523 | Matrix may be changed by translate(), scale(), rotate(), skew(), concat(), setMatrix, and resetMatrix. |
| 1524 | Clip may be changed by clipRect, clipRRect, clipPath, clipRegion. |
| 1525 | |
| 1526 | bounds suggests but does not define the offscreen size. To clip drawing to a specific rectangle, |
| 1527 | use clipRect. |
| 1528 | |
| 1529 | Call restoreToCount with result to restore this and subsequent saves. |
| 1530 | |
| 1531 | #Param bounds Used as a hint to limit the size of the offscreen; may be nullptr. ## |
| 1532 | #Param alpha The opacity of the offscreen; zero is fully transparent, 255 is fully opaque. ## |
| 1533 | |
| 1534 | #Return Depth of saved stack. ## |
| 1535 | |
| 1536 | #Example |
| 1537 | SkPaint paint;
|
| 1538 | paint.setColor(SK_ColorRED);
|
| 1539 | canvas->drawCircle(50, 50, 50, paint);
|
| 1540 | canvas->saveLayerAlpha(nullptr, 128);
|
| 1541 | paint.setColor(SK_ColorBLUE);
|
| 1542 | canvas->drawCircle(100, 50, 50, paint);
|
| 1543 | paint.setColor(SK_ColorGREEN);
|
| 1544 | paint.setAlpha(128);
|
| 1545 | canvas->drawCircle(75, 90, 50, paint);
|
| 1546 | canvas->restore(); |
| 1547 | ## |
| 1548 | |
| 1549 | #ToDo incomplete ## |
| 1550 | |
| 1551 | ## |
| 1552 | |
| 1553 | #Enum SaveLayerFlags |
| 1554 | |
| 1555 | #Code |
| 1556 | enum { |
| 1557 | kIsOpaque_SaveLayerFlag = 1 << 0, |
| 1558 | kPreserveLCDText_SaveLayerFlag = 1 << 1, |
| 1559 | kInitWithPrevious_SaveLayerFlag = 1 << 2, |
| 1560 | }; |
| 1561 | |
| 1562 | typedef uint32_t SaveLayerFlags; |
| 1563 | ## |
| 1564 | |
| 1565 | SaveLayerFlags provides options that may be used in any combination in SaveLayerRec, |
| 1566 | defining how the offscreen allocated by saveLayer operates. |
| 1567 | |
| 1568 | #Const kIsOpaque_SaveLayerFlag 1 |
| 1569 | Creates offscreen without transparency. Flag is ignored if layer Paint contains |
| 1570 | Image_Filter or Color_Filter. |
| 1571 | ## |
| 1572 | |
| 1573 | #Const kPreserveLCDText_SaveLayerFlag 2 |
| 1574 | Creates offscreen for LCD text. Flag is ignored if layer Paint contains |
| 1575 | Image_Filter or Color_Filter. |
| 1576 | ## |
| 1577 | |
| 1578 | #Const kInitWithPrevious_SaveLayerFlag 4 |
| 1579 | Initializes offscreen with the contents of the previous layer. |
| 1580 | ## |
| 1581 | |
| 1582 | #Example |
| 1583 | #Height 160 |
| 1584 | #Description |
| 1585 | Canvas layer captures red and blue circles scaled up by four. |
| 1586 | scalePaint blends offscreen back with transparency. |
| 1587 | ## |
| 1588 | void draw(SkCanvas* canvas) {
|
| 1589 | SkPaint redPaint, bluePaint, scalePaint;
|
| 1590 | redPaint.setColor(SK_ColorRED);
|
| 1591 | canvas->drawCircle(21, 21, 8, redPaint);
|
| 1592 | bluePaint.setColor(SK_ColorBLUE);
|
| 1593 | canvas->drawCircle(31, 21, 8, bluePaint);
|
| 1594 | SkMatrix matrix;
|
| 1595 | matrix.setScale(4, 4);
|
| 1596 | scalePaint.setAlpha(0x40);
|
| 1597 | scalePaint.setImageFilter(
|
| 1598 | SkImageFilter::MakeMatrixFilter(matrix, kNone_SkFilterQuality, nullptr));
|
| 1599 | SkCanvas::SaveLayerRec saveLayerRec(nullptr, &scalePaint,
|
| 1600 | SkCanvas::kInitWithPrevious_SaveLayerFlag);
|
| 1601 | canvas->saveLayer(saveLayerRec);
|
| 1602 | canvas->restore();
|
| 1603 | } |
| 1604 | ## |
| 1605 | |
| 1606 | #ToDo incomplete ## |
| 1607 | |
| 1608 | #Enum ## |
| 1609 | |
| 1610 | #Struct SaveLayerRec |
| 1611 | |
| 1612 | #Code |
| 1613 | struct SaveLayerRec { |
| 1614 | SaveLayerRec*(... |
| 1615 | |
| 1616 | const SkRect* fBounds; |
| 1617 | const SkPaint* fPaint; |
| 1618 | const SkImageFilter* fBackdrop; |
| 1619 | SaveLayerFlags fSaveLayerFlags; |
| 1620 | }; |
| 1621 | ## |
| 1622 | |
| 1623 | SaveLayerRec contains the state used to create the layer offscreen. |
| 1624 | |
| 1625 | #Member const SkRect* fBounds |
| 1626 | fBounds is used as a hint to limit the size of the offscreen; may be nullptr. |
| 1627 | fBounds suggests but does not define the offscreen size. To clip drawing to a specific rectangle, |
| 1628 | use clipRect. |
| 1629 | ## |
| 1630 | |
| 1631 | #Member const SkPaint* fPaint |
| 1632 | fPaint modifies how the offscreen overlays the prior layer; may be nullptr. Color_Alpha, Blend_Mode, |
| 1633 | Color_Filter, Draw_Looper, Image_Filter, and Mask_Filter affect the offscreen draw. |
| 1634 | ## |
| 1635 | |
| 1636 | #Member const SkImageFilter* fBackdrop |
| 1637 | fBackdrop applies Image_Filter to the prior layer when copying to the layer offscreen; may be nullptr. |
| 1638 | Use kInitWithPrevious_SaveLayerFlag to copy the prior layer without a Image_Filter. |
| 1639 | ## |
| 1640 | |
| 1641 | #Member const SkImage* fClipMask |
| 1642 | #ToDo header documentation is incomplete ## |
| 1643 | may be nullptr. |
| 1644 | ## |
| 1645 | |
| 1646 | #Member const SkMatrix* fClipMatrix |
| 1647 | #ToDo header documentation is incomplete ## |
| 1648 | may be nullptr. |
| 1649 | ## |
| 1650 | |
| 1651 | #Member SaveLayerFlags fSaveLayerFlags |
| 1652 | fSaveLayerFlags are used to create layer offscreen without transparency, create layer offscreen for |
| 1653 | LCD text, and to create layer offscreen with the contents of the previous layer. |
| 1654 | ## |
| 1655 | |
| 1656 | #Example |
| 1657 | #Height 160 |
| 1658 | #Description |
| 1659 | Canvas layer captures a red anti-aliased circle and a blue aliased circle scaled up by four. |
| 1660 | After drawing another unscaled red circle on top, the offscreen is transferred to the main canvas. |
| 1661 | ## |
| 1662 | void draw(SkCanvas* canvas) {
|
| 1663 | SkPaint redPaint, bluePaint;
|
| 1664 | redPaint.setAntiAlias(true);
|
| 1665 | redPaint.setColor(SK_ColorRED);
|
| 1666 | canvas->drawCircle(21, 21, 8, redPaint);
|
| 1667 | bluePaint.setColor(SK_ColorBLUE);
|
| 1668 | canvas->drawCircle(31, 21, 8, bluePaint);
|
| 1669 | SkMatrix matrix;
|
| 1670 | matrix.setScale(4, 4);
|
| 1671 | auto scaler = SkImageFilter::MakeMatrixFilter(matrix, kNone_SkFilterQuality, nullptr);
|
| 1672 | SkCanvas::SaveLayerRec saveLayerRec(nullptr, nullptr, scaler.get(), 0);
|
| 1673 | canvas->saveLayer(saveLayerRec);
|
| 1674 | canvas->drawCircle(125, 85, 8, redPaint);
|
| 1675 | canvas->restore();
|
| 1676 | } |
| 1677 | ## |
| 1678 | |
| 1679 | #Method SaveLayerRec() |
| 1680 | |
| 1681 | Sets fBounds, fPaint, and fBackdrop to nullptr. Clears fSaveLayerFlags. |
| 1682 | |
| 1683 | #Return empty SaveLayerRec. ## |
| 1684 | |
| 1685 | #Example |
| 1686 | SkCanvas::SaveLayerRec rec1;
|
| 1687 | rec1.fSaveLayerFlags = SkCanvas::kIsOpaque_SaveLayerFlag;
|
| 1688 | SkCanvas::SaveLayerRec rec2(nullptr, nullptr, SkCanvas::kIsOpaque_SaveLayerFlag);
|
| 1689 | SkDebugf("rec1 %c= rec2\n", rec1.fBounds == rec2.fBounds
|
| 1690 | && rec1.fPaint == rec2.fPaint
|
| 1691 | && rec1.fBackdrop == rec2.fBackdrop
|
| 1692 | && rec1.fSaveLayerFlags == rec2.fSaveLayerFlags ? '=' : '!'); |
| 1693 | #StdOut |
| 1694 | rec1 == rec2 |
| 1695 | ## |
| 1696 | ## |
| 1697 | |
| 1698 | ## |
| 1699 | |
| 1700 | #Method SaveLayerRec(const SkRect* bounds, const SkPaint* paint, SaveLayerFlags saveLayerFlags = 0) |
| 1701 | |
| 1702 | Sets fBounds, fPaint, and fSaveLayerFlags; sets fBackdrop to nullptr. |
| 1703 | |
| 1704 | #Param bounds Offscreen dimensions; may be nullptr. ## |
| 1705 | #Param paint Applied to offscreen when overlaying prior layer; may be nullptr. ## |
| 1706 | #Param saveLayerFlags SaveLayerRec options to modify offscreen. ## |
| 1707 | |
| 1708 | #Return SaveLayerRec with empty backdrop. ## |
| 1709 | |
| 1710 | #Example |
| 1711 | SkCanvas::SaveLayerRec rec1;
|
| 1712 | SkCanvas::SaveLayerRec rec2(nullptr, nullptr);
|
| 1713 | SkDebugf("rec1 %c= rec2\n", rec1.fBounds == rec2.fBounds
|
| 1714 | && rec1.fPaint == rec2.fPaint
|
| 1715 | && rec1.fBackdrop == rec2.fBackdrop
|
| 1716 | && rec1.fSaveLayerFlags == rec2.fSaveLayerFlags ? '=' : '!'); |
| 1717 | #StdOut |
| 1718 | rec1 == rec2 |
| 1719 | ## |
| 1720 | ## |
| 1721 | |
| 1722 | ## |
| 1723 | |
| 1724 | #Method SaveLayerRec(const SkRect* bounds, const SkPaint* paint, const SkImageFilter* backdrop, |
| 1725 | SaveLayerFlags saveLayerFlags) |
| 1726 | |
| 1727 | Sets fBounds, fPaint, fBackdrop, and fSaveLayerFlags. |
| 1728 | |
| 1729 | #Param bounds Offscreen dimensions; may be nullptr. ## |
| 1730 | #Param paint Applied to offscreen when overlaying prior layer; may be nullptr. ## |
| 1731 | #Param backdrop Copies prior layer to offscreen with Image_Filter; may be nullptr. ## |
| 1732 | #Param saveLayerFlags SaveLayerRec options to modify offscreen. ## |
| 1733 | |
| 1734 | #Return SaveLayerRec fully specified. ## |
| 1735 | |
| 1736 | #Example |
| 1737 | SkCanvas::SaveLayerRec rec1;
|
| 1738 | SkCanvas::SaveLayerRec rec2(nullptr, nullptr, nullptr, 0);
|
| 1739 | SkDebugf("rec1 %c= rec2\n", rec1.fBounds == rec2.fBounds
|
| 1740 | && rec1.fPaint == rec2.fPaint
|
| 1741 | && rec1.fBackdrop == rec2.fBackdrop
|
| 1742 | && rec1.fSaveLayerFlags == rec2.fSaveLayerFlags ? '=' : '!'); |
| 1743 | #StdOut |
| 1744 | rec1 == rec2 |
| 1745 | ## |
| 1746 | ## |
| 1747 | |
| 1748 | ## |
| 1749 | |
| 1750 | #Method SaveLayerRec(const SkRect* bounds, const SkPaint* paint, const SkImageFilter* backdrop, |
| 1751 | const SkImage* clipMask, const SkMatrix* clipMatrix, |
| 1752 | SaveLayerFlags saveLayerFlags) |
| 1753 | |
| 1754 | #Experimental |
| 1755 | Not ready for general use. |
| 1756 | ## |
| 1757 | |
| 1758 | #Param bounds Offscreen dimensions; may be nullptr. ## |
| 1759 | #Param paint Applied to offscreen when overlaying prior layer; may be nullptr. ## |
| 1760 | #Param backdrop Copies prior layer to offscreen with Image_Filter; may be nullptr. ## |
| 1761 | #Param clipMask May be nullptr. ## |
| 1762 | #Param clipMatrix May be nullptr. ## |
| 1763 | #Param saveLayerFlags SaveLayerRec options to modify offscreen. ## |
| 1764 | |
| 1765 | #Return SaveLayerRec fully specified. ## |
| 1766 | |
| 1767 | #ToDo incomplete ## |
| 1768 | |
| 1769 | ## |
| 1770 | |
| 1771 | #Struct ## |
| 1772 | |
| 1773 | #Method int saveLayer(const SaveLayerRec& layerRec) |
| 1774 | |
| 1775 | Saves Matrix, Clip, and Draw_Filter (Draw_Filter deprecated on most platforms), |
| 1776 | and allocates an offscreen bitmap for subsequent drawing. |
| 1777 | |
| 1778 | Calling restore() discards changes to Matrix, Clip, and Draw_Filter, |
| 1779 | and blends the offscreen bitmap with alpha opacity onto the prior layer. |
| 1780 | The Matrix, Clip, and Draw_Filter are restored to their state when save() was called. |
| 1781 | |
| 1782 | Matrix may be changed by translate(), scale(), rotate(), skew(), concat(), setMatrix, and resetMatrix. |
| 1783 | Clip may be changed by clipRect, clipRRect, clipPath, clipRegion. |
| 1784 | |
| 1785 | SaveLayerRec contains the state used to create the layer offscreen. |
| 1786 | |
| 1787 | Call restoreToCount with result to restore this and subsequent saves. |
| 1788 | |
| 1789 | #Param layerRec offscreen state. ## |
| 1790 | |
| 1791 | #Return depth of save state stack. ## |
| 1792 | |
| 1793 | #Example |
| 1794 | #Description |
| 1795 | The example draws an image, and saves it into a layer with kInitWithPrevious_SaveLayerFlag. |
| 1796 | Next it punches a hole in the layer and restore with SkBlendMode::kPlus. |
| 1797 | Where the layer was cleared, the original image will draw unchanged. |
| 1798 | Outside of the circle the mandrill is brightened. |
| 1799 | ## |
| 1800 | #Image 3 |
| 1801 | // sk_sp<SkImage> image = GetResourceAsImage("mandrill_256.png"); |
| 1802 | canvas->drawImage(image, 0, 0, nullptr); |
| 1803 | SkCanvas::SaveLayerRec rec; |
| 1804 | SkPaint paint; |
| 1805 | paint.setBlendMode(SkBlendMode::kPlus); |
| 1806 | rec.fSaveLayerFlags = SkCanvas::kInitWithPrevious_SaveLayerFlag; |
| 1807 | rec.fPaint = &paint; |
| 1808 | canvas->saveLayer(rec); |
| 1809 | paint.setBlendMode(SkBlendMode::kClear); |
| 1810 | canvas->drawCircle(128, 128, 96, paint); |
| 1811 | canvas->restore(); |
| 1812 | ## |
| 1813 | |
| 1814 | #ToDo above example needs to replace GetResourceAsImage with way to select image in fiddle ## |
| 1815 | |
| 1816 | ## |
| 1817 | |
| 1818 | #Subtopic Layer ## |
| 1819 | |
| 1820 | # ------------------------------------------------------------------------------ |
| 1821 | |
| 1822 | #Method void restore() |
| 1823 | |
| 1824 | Removes changes to Matrix, Clip, and Draw_Filter since Canvas state was |
| 1825 | last saved. The state is removed from the stack. |
| 1826 | |
| 1827 | Does nothing if the stack is empty. |
| 1828 | |
| 1829 | #Example |
| 1830 | void draw(SkCanvas* canvas) {
|
| 1831 | SkCanvas simple;
|
| 1832 | SkDebugf("depth = %d\n", simple.getSaveCount());
|
| 1833 | simple.restore();
|
| 1834 | SkDebugf("depth = %d\n", simple.getSaveCount());
|
| 1835 | } |
| 1836 | ## |
| 1837 | |
| 1838 | ## |
| 1839 | |
| 1840 | # ------------------------------------------------------------------------------ |
| 1841 | |
| 1842 | #Method int getSaveCount() const |
| 1843 | |
| 1844 | Returns the number of saved states, each containing: Matrix, Clip, and Draw_Filter. |
| 1845 | Equals the number of save() calls less the number of restore() calls plus one. |
| 1846 | The save count of a new canvas is one. |
| 1847 | |
| 1848 | #Return depth of save state stack. ## |
| 1849 | |
| 1850 | #Example |
| 1851 | void draw(SkCanvas* canvas) {
|
| 1852 | SkCanvas simple;
|
| 1853 | SkDebugf("depth = %d\n", simple.getSaveCount());
|
| 1854 | simple.save();
|
| 1855 | SkDebugf("depth = %d\n", simple.getSaveCount());
|
| 1856 | simple.restore();
|
| 1857 | SkDebugf("depth = %d\n", simple.getSaveCount());
|
| 1858 | } |
| 1859 | #StdOut |
| 1860 | depth = 1
|
| 1861 | depth = 2
|
| 1862 | depth = 1 |
| 1863 | ## |
| 1864 | ## |
| 1865 | |
| 1866 | ## |
| 1867 | |
| 1868 | # ------------------------------------------------------------------------------ |
| 1869 | |
| 1870 | #Method void restoreToCount(int saveCount) |
| 1871 | |
| 1872 | Restores state to Matrix, Clip, and Draw_Filter |
| 1873 | values when save(), saveLayer, saveLayerPreserveLCDTextRequests, or saveLayerAlpha |
| 1874 | returned saveCount. |
| 1875 | |
| 1876 | Does nothing if saveCount is greater than state stack count. |
| 1877 | Restores state to initial values if saveCount is less than or equal to one. |
| 1878 | |
| 1879 | #Param saveCount The depth of state stack to restore. ## |
| 1880 | |
| 1881 | #Example |
| 1882 | void draw(SkCanvas* canvas) {
|
| 1883 | SkDebugf("depth = %d\n", canvas->getSaveCount());
|
| 1884 | canvas->save();
|
| 1885 | canvas->save();
|
| 1886 | SkDebugf("depth = %d\n", canvas->getSaveCount());
|
| 1887 | canvas->restoreToCount(0);
|
| 1888 | SkDebugf("depth = %d\n", canvas->getSaveCount());
|
| 1889 | } |
| 1890 | #StdOut |
| 1891 | depth = 1
|
| 1892 | depth = 3
|
| 1893 | depth = 1 |
| 1894 | ## |
| 1895 | ## |
| 1896 | |
| 1897 | ## |
| 1898 | |
| 1899 | #Topic State_Stack ## |
| 1900 | |
| 1901 | # ------------------------------------------------------------------------------ |
| 1902 | #Topic Matrix |
| 1903 | |
| 1904 | #Method void translate(SkScalar dx, SkScalar dy) |
| 1905 | |
| 1906 | Translate Matrix by dx along the x-axis and dy along the y-axis. |
| 1907 | |
| 1908 | Mathematically, replace Matrix with a translation matrix |
| 1909 | pre-multiplied with Matrix. |
| 1910 | |
| 1911 | This has the effect of moving the drawing by (dx, dy) before transforming |
| 1912 | the result with Matrix. |
| 1913 | |
| 1914 | #Param dx The distance to translate in x. ## |
| 1915 | #Param dy The distance to translate in y. ## |
| 1916 | |
| 1917 | #Example |
| 1918 | #Height 128 |
| 1919 | #Description |
| 1920 | scale() followed by translate() produces different results from translate() followed |
| 1921 | by scale(). |
| 1922 | |
| 1923 | The blue stroke follows translate of (50, 50); a black |
| 1924 | fill follows scale of (2, 1/2.f). After restoring the clip, which resets |
| 1925 | Matrix, a red frame follows the same scale of (2, 1/2.f); a gray fill |
| 1926 | follows translate of (50, 50). |
| 1927 | ## |
| 1928 | void draw(SkCanvas* canvas) {
|
| 1929 | SkPaint filledPaint;
|
| 1930 | SkPaint outlinePaint;
|
| 1931 | outlinePaint.setStyle(SkPaint::kStroke_Style);
|
| 1932 | outlinePaint.setColor(SK_ColorBLUE);
|
| 1933 | canvas->save();
|
| 1934 | canvas->translate(50, 50);
|
| 1935 | canvas->drawCircle(28, 28, 15, outlinePaint); // blue center: (50+28, 50+28)
|
| 1936 | canvas->scale(2, 1/2.f);
|
| 1937 | canvas->drawCircle(28, 28, 15, filledPaint); // black center: (50+(28*2), 50+(28/2))
|
| 1938 | canvas->restore();
|
| 1939 | filledPaint.setColor(SK_ColorGRAY);
|
| 1940 | outlinePaint.setColor(SK_ColorRED);
|
| 1941 | canvas->scale(2, 1/2.f);
|
| 1942 | canvas->drawCircle(28, 28, 15, outlinePaint); // red center: (28*2, 28/2)
|
| 1943 | canvas->translate(50, 50);
|
| 1944 | canvas->drawCircle(28, 28, 15, filledPaint); // gray center: ((50+28)*2, (50+28)/2)
|
| 1945 | } |
| 1946 | ## |
| 1947 | |
| 1948 | #ToDo incomplete ## |
| 1949 | |
| 1950 | ## |
| 1951 | |
| 1952 | # ------------------------------------------------------------------------------ |
| 1953 | |
| 1954 | #Method void scale(SkScalar sx, SkScalar sy) |
| 1955 | |
| 1956 | Scale Matrix by sx on the x-axis and sy on the y-axis. |
| 1957 | |
| 1958 | Mathematically, replace Matrix with a scale matrix |
| 1959 | pre-multiplied with Matrix. |
| 1960 | |
| 1961 | This has the effect of scaling the drawing by (sx, sy) before transforming |
| 1962 | the result with Matrix. |
| 1963 | |
| 1964 | #Param sx The amount to scale in x. ## |
| 1965 | #Param sy The amount to scale in y. ## |
| 1966 | |
| 1967 | #Example |
| 1968 | #Height 160 |
| 1969 | void draw(SkCanvas* canvas) {
|
| 1970 | SkPaint paint;
|
| 1971 | SkRect rect = { 10, 20, 60, 120 };
|
| 1972 | canvas->translate(20, 20);
|
| 1973 | canvas->drawRect(rect, paint);
|
| 1974 | canvas->scale(2, .5f);
|
| 1975 | paint.setColor(SK_ColorGRAY);
|
| 1976 | canvas->drawRect(rect, paint);
|
| 1977 | } |
| 1978 | ## |
| 1979 | |
| 1980 | #ToDo incomplete ## |
| 1981 | |
| 1982 | ## |
| 1983 | |
| 1984 | # ------------------------------------------------------------------------------ |
| 1985 | |
| 1986 | #Method void rotate(SkScalar degrees) |
| 1987 | |
| 1988 | Rotate Matrix by degrees. Positive degrees rotates clockwise. |
| 1989 | |
| 1990 | Mathematically, replace Matrix with a rotation matrix |
| 1991 | pre-multiplied with Matrix. |
| 1992 | |
| 1993 | This has the effect of rotating the drawing by degrees before transforming |
| 1994 | the result with Matrix. |
| 1995 | |
| 1996 | #Param degrees The amount to rotate, in degrees. ## |
| 1997 | |
| 1998 | #Example |
| 1999 | #Description |
| 2000 | Draw clock hands at time 5:10. The hour hand and minute hand point up and |
| 2001 | are rotated clockwise. |
| 2002 | ## |
| 2003 | void draw(SkCanvas* canvas) {
|
| 2004 | SkPaint paint;
|
| 2005 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2006 | canvas->translate(128, 128);
|
| 2007 | canvas->drawCircle(0, 0, 60, paint);
|
| 2008 | canvas->save();
|
| 2009 | canvas->rotate(10 * 360 / 60); // 10 minutes of 60 scaled to 360 degrees
|
| 2010 | canvas->drawLine(0, 0, 0, -50, paint);
|
| 2011 | canvas->restore();
|
| 2012 | canvas->rotate((5 + 10.f/60) * 360 / 12); // 5 and 10/60 hours of 12 scaled to 360 degrees
|
| 2013 | canvas->drawLine(0, 0, 0, -30, paint);
|
| 2014 | } |
| 2015 | ## |
| 2016 | |
| 2017 | #ToDo incomplete ## |
| 2018 | |
| 2019 | ## |
| 2020 | |
| 2021 | # ------------------------------------------------------------------------------ |
| 2022 | |
| 2023 | #Method void rotate(SkScalar degrees, SkScalar px, SkScalar py) |
| 2024 | |
| 2025 | Rotate Matrix by degrees about a point at (px, py). Positive degrees rotates clockwise. |
| 2026 | |
| 2027 | Mathematically, construct a rotation matrix. Pre-multiply the rotation matrix by |
| 2028 | a translation matrix, then replace Matrix with the resulting matrix |
| 2029 | pre-multiplied with Matrix. |
| 2030 | |
| 2031 | This has the effect of rotating the drawing about a given point before transforming |
| 2032 | the result with Matrix. |
| 2033 | |
| 2034 | #Param degrees The amount to rotate, in degrees. ## |
| 2035 | #Param px The x coordinate of the point to rotate about. ## |
| 2036 | #Param py The y coordinate of the point to rotate about. ## |
| 2037 | |
| 2038 | #Example |
| 2039 | #Height 192 |
| 2040 | void draw(SkCanvas* canvas) {
|
| 2041 | SkPaint paint;
|
| 2042 | paint.setTextSize(96);
|
| 2043 | canvas->drawString("A1", 130, 100, paint);
|
| 2044 | canvas->rotate(180, 130, 100);
|
| 2045 | canvas->drawString("A1", 130, 100, paint);
|
| 2046 | } |
| 2047 | ## |
| 2048 | |
| 2049 | #ToDo incomplete ## |
| 2050 | |
| 2051 | ## |
| 2052 | |
| 2053 | # ------------------------------------------------------------------------------ |
| 2054 | |
| 2055 | #Method void skew(SkScalar sx, SkScalar sy) |
| 2056 | |
| 2057 | Skew Matrix by sx on the x-axis and sy on the y-axis. A positive value of sx skews the |
| 2058 | drawing right as y increases; a positive value of sy skews the drawing down as x increases. |
| 2059 | |
| 2060 | Mathematically, replace Matrix with a skew matrix |
| 2061 | pre-multiplied with Matrix. |
| 2062 | |
| 2063 | Preconcat the current matrix with the specified skew. |
| 2064 | #Param sx The amount to skew in x. ## |
| 2065 | #Param sy The amount to skew in y. ## |
| 2066 | |
| 2067 | This has the effect of scaling the drawing by (sx, sy) before transforming |
| 2068 | the result with Matrix. |
| 2069 | |
| 2070 | #Example |
| 2071 | #Description |
| 2072 | Black text mimics an oblique text style by using a negative skew in x that |
| 2073 | shifts the geometry to the right as the y values decrease. |
| 2074 | Red text uses a positive skew in y to shift the geometry down as the x values |
| 2075 | increase. |
| 2076 | Blue text combines x and y skew to rotate and scale. |
| 2077 | ## |
| 2078 | SkPaint paint;
|
| 2079 | paint.setTextSize(128);
|
| 2080 | canvas->translate(30, 130);
|
| 2081 | canvas->save();
|
| 2082 | canvas->skew(-.5, 0);
|
| 2083 | canvas->drawString("A1", 0, 0, paint);
|
| 2084 | canvas->restore();
|
| 2085 | canvas->save();
|
| 2086 | canvas->skew(0, .5);
|
| 2087 | paint.setColor(SK_ColorRED);
|
| 2088 | canvas->drawString("A1", 0, 0, paint);
|
| 2089 | canvas->restore();
|
| 2090 | canvas->skew(-.5, .5);
|
| 2091 | paint.setColor(SK_ColorBLUE);
|
| 2092 | canvas->drawString("A1", 0, 0, paint); |
| 2093 | ## |
| 2094 | |
| 2095 | #ToDo incomplete ## |
| 2096 | |
| 2097 | ## |
| 2098 | |
| 2099 | # ------------------------------------------------------------------------------ |
| 2100 | |
| 2101 | #Method void concat(const SkMatrix& matrix) |
| 2102 | |
| 2103 | Replace Matrix with matrix pre-multiplied with Matrix. |
| 2104 | |
| 2105 | This has the effect of transforming the drawn geometry by matrix, before transforming |
| 2106 | the result with Matrix. |
| 2107 | |
| 2108 | #Param matrix Pre-multiply with Matrix. ## |
| 2109 | |
| 2110 | #Example |
| 2111 | void draw(SkCanvas* canvas) {
|
| 2112 | SkPaint paint;
|
| 2113 | paint.setTextSize(80);
|
| 2114 | paint.setTextScaleX(.3);
|
| 2115 | SkMatrix matrix;
|
| 2116 | SkRect rect[2] = {{ 10, 20, 90, 110 }, { 40, 130, 140, 180 }};
|
| 2117 | matrix.setRectToRect(rect[0], rect[1], SkMatrix::kFill_ScaleToFit);
|
| 2118 | canvas->drawRect(rect[0], paint);
|
| 2119 | canvas->drawRect(rect[1], paint);
|
| 2120 | paint.setColor(SK_ColorWHITE);
|
| 2121 | canvas->drawString("Here", rect[0].fLeft + 10, rect[0].fBottom - 10, paint);
|
| 2122 | canvas->concat(matrix);
|
| 2123 | canvas->drawString("There", rect[0].fLeft + 10, rect[0].fBottom - 10, paint);
|
| 2124 | } |
| 2125 | ## |
| 2126 | |
| 2127 | #ToDo incomplete ## |
| 2128 | |
| 2129 | ## |
| 2130 | |
| 2131 | # ------------------------------------------------------------------------------ |
| 2132 | |
| 2133 | #Method void setMatrix(const SkMatrix& matrix) |
| 2134 | |
| 2135 | Replace Matrix with matrix. |
| 2136 | Unlike concat(), any prior matrix state is overwritten. |
| 2137 | |
| 2138 | #Param matrix Copied into Matrix. ## |
| 2139 | |
| 2140 | #Example |
| 2141 | #Height 128 |
| 2142 | void draw(SkCanvas* canvas) {
|
| 2143 | SkPaint paint;
|
| 2144 | canvas->scale(4, 6);
|
| 2145 | canvas->drawString("truth", 2, 10, paint);
|
| 2146 | SkMatrix matrix;
|
| 2147 | matrix.setScale(2.8f, 6);
|
| 2148 | canvas->setMatrix(matrix);
|
| 2149 | canvas->drawString("consequences", 2, 20, paint);
|
| 2150 | } |
| 2151 | ## |
| 2152 | |
| 2153 | #ToDo incomplete ## |
| 2154 | |
| 2155 | ## |
| 2156 | |
| 2157 | # ------------------------------------------------------------------------------ |
| 2158 | |
| 2159 | #Method void resetMatrix() |
| 2160 | |
| 2161 | Sets Matrix to the identity matrix. |
| 2162 | Any prior matrix state is overwritten. |
| 2163 | |
| 2164 | #Example |
| 2165 | #Height 128 |
| 2166 | void draw(SkCanvas* canvas) {
|
| 2167 | SkPaint paint;
|
| 2168 | canvas->scale(4, 6);
|
| 2169 | canvas->drawString("truth", 2, 10, paint);
|
| 2170 | canvas->resetMatrix();
|
| 2171 | canvas->scale(2.8f, 6);
|
| 2172 | canvas->drawString("consequences", 2, 20, paint);
|
| 2173 | } |
| 2174 | ## |
| 2175 | |
| 2176 | #ToDo incomplete ## |
| 2177 | |
| 2178 | ## |
| 2179 | |
| 2180 | # ------------------------------------------------------------------------------ |
| 2181 | |
| 2182 | #Method const SkMatrix& getTotalMatrix() const |
| 2183 | |
| 2184 | Returns Matrix. |
| 2185 | This does not account for translation by Device or Surface. |
| 2186 | |
| 2187 | #Return Matrix on Canvas. ## |
| 2188 | |
| 2189 | #Example |
| 2190 | SkDebugf("isIdentity %s\n", canvas->getTotalMatrix().isIdentity() ? "true" : "false");
|
| 2191 | #StdOut
|
| 2192 | isIdentity true
|
| 2193 | ##
|
| 2194 | ## |
| 2195 | |
| 2196 | #ToDo incomplete ## |
| 2197 | |
| 2198 | ## |
| 2199 | |
| 2200 | #Topic Matrix ## |
| 2201 | |
| 2202 | # ------------------------------------------------------------------------------ |
| 2203 | #Topic Clip |
| 2204 | |
| 2205 | Clip is built from a stack of clipping paths. Each Path in the |
| 2206 | stack can be constructed from one or more Path_Contour elements. The |
| 2207 | Path_Contour may be composed of any number of Path_Verb segments. Each |
| 2208 | Path_Contour forms a closed area; Path_Fill_Type defines the area enclosed |
| 2209 | by Path_Contour. |
| 2210 | |
| 2211 | Clip stack of Path elements successfully restrict the Path area. Each |
| 2212 | Path is transformed by Matrix, then intersected with or subtracted from the |
| 2213 | prior Clip to form the replacement Clip. Use SkClipOp::kDifference |
| 2214 | to subtract Path from Clip; use SkClipOp::kIntersect to intersect Path |
| 2215 | with Clip. |
| 2216 | |
| 2217 | A clipping Path may be anti-aliased; if Path, after transformation, is |
| 2218 | composed of horizontal and vertical lines, clearing Anti-alias allows whole pixels |
| 2219 | to either be inside or outside the clip. The fastest drawing has a aliased, |
| 2220 | rectanglar clip. |
| 2221 | |
| 2222 | If clipping Path has Anti-alias set, clip may partially clip a pixel, requiring |
| 2223 | that drawing blend partially with the destination along the edge. A rotated |
| 2224 | rectangular anti-aliased clip looks smoother but draws slower. |
| 2225 | |
| 2226 | Clip can combine with Rect and Round_Rect primitives; like |
| 2227 | Path, these are transformed by Matrix before they are combined with Clip. |
| 2228 | |
| 2229 | Clip can combine with Region. Region is assumed to be in Device coordinates |
| 2230 | and is unaffected by Matrix. |
| 2231 | |
| 2232 | #Example |
| 2233 | #Height 90 |
| 2234 | #Description |
| 2235 | Draw a red circle with an aliased clip and an anti-aliased clip. |
| 2236 | Use an image filter to zoom into the pixels drawn. |
| 2237 | The edge of the aliased clip fully draws pixels in the red circle. |
| 2238 | The edge of the anti-aliased clip partially draws pixels in the red circle. |
| 2239 | ## |
| 2240 | SkPaint redPaint, scalePaint;
|
| 2241 | redPaint.setAntiAlias(true);
|
| 2242 | redPaint.setColor(SK_ColorRED);
|
| 2243 | canvas->save();
|
| 2244 | for (bool antialias : { false, true } ) {
|
| 2245 | canvas->save();
|
| 2246 | canvas->clipRect(SkRect::MakeWH(19.5f, 11.5f), antialias);
|
| 2247 | canvas->drawCircle(17, 11, 8, redPaint);
|
| 2248 | canvas->restore();
|
| 2249 | canvas->translate(16, 0);
|
| 2250 | }
|
| 2251 | canvas->restore();
|
| 2252 | SkMatrix matrix;
|
| 2253 | matrix.setScale(6, 6);
|
| 2254 | scalePaint.setImageFilter(
|
| 2255 | SkImageFilter::MakeMatrixFilter(matrix, kNone_SkFilterQuality, nullptr));
|
| 2256 | SkCanvas::SaveLayerRec saveLayerRec(
|
| 2257 | nullptr, &scalePaint, SkCanvas::kInitWithPrevious_SaveLayerFlag);
|
| 2258 | canvas->saveLayer(saveLayerRec);
|
| 2259 | canvas->restore(); |
| 2260 | ## |
| 2261 | |
| 2262 | #Method void clipRect(const SkRect& rect, SkClipOp op, bool doAntiAlias) |
| 2263 | |
| 2264 | Replace Clip with the intersection or difference of Clip and rect, |
| 2265 | with an aliased or anti-aliased clip edge. rect is transformed by Matrix |
| 2266 | before it is combined with Clip. |
| 2267 | |
| 2268 | #Param rect Rectangle to combine with Clip. ## |
| 2269 | #Param op Clip_Op to apply to Clip. ## |
| 2270 | #Param doAntiAlias true if Clip is to be anti-aliased. ## |
| 2271 | |
| 2272 | #Example |
| 2273 | #Height 128 |
| 2274 | void draw(SkCanvas* canvas) {
|
| 2275 | canvas->rotate(10);
|
| 2276 | SkPaint paint;
|
| 2277 | paint.setAntiAlias(true);
|
| 2278 | for (auto alias: { false, true } ) {
|
| 2279 | canvas->save();
|
| 2280 | canvas->clipRect(SkRect::MakeWH(90, 80), SkClipOp::kIntersect, alias);
|
| 2281 | canvas->drawCircle(100, 60, 60, paint);
|
| 2282 | canvas->restore();
|
| 2283 | canvas->translate(80, 0);
|
| 2284 | }
|
| 2285 | } |
| 2286 | ## |
| 2287 | |
| 2288 | #ToDo incomplete ## |
| 2289 | |
| 2290 | ## |
| 2291 | |
| 2292 | #Method void clipRect(const SkRect& rect, SkClipOp op) |
| 2293 | |
| 2294 | Replace Clip with the intersection or difference of Clip and rect. |
| 2295 | Resulting Clip is aliased; pixels are fully contained by the clip. |
| 2296 | rect is transformed by Matrix |
| 2297 | before it is combined with Clip. |
| 2298 | |
| 2299 | #Param rect Rectangle to combine with Clip. ## |
| 2300 | #Param op Clip_Op to apply to Clip. ## |
| 2301 | |
| 2302 | #Example |
| 2303 | #Height 192 |
| 2304 | #Width 280 |
| 2305 | void draw(SkCanvas* canvas) {
|
| 2306 | SkPaint paint;
|
| 2307 | for (SkClipOp op: { SkClipOp::kIntersect, SkClipOp::kDifference } ) {
|
| 2308 | canvas->save();
|
| 2309 | canvas->clipRect(SkRect::MakeWH(90, 120), op, false);
|
| 2310 | canvas->drawCircle(100, 100, 60, paint);
|
| 2311 | canvas->restore();
|
| 2312 | canvas->translate(80, 0);
|
| 2313 | }
|
| 2314 | } |
| 2315 | ## |
| 2316 | |
| 2317 | #ToDo incomplete ## |
| 2318 | |
| 2319 | ## |
| 2320 | |
| 2321 | #Method void clipRect(const SkRect& rect, bool doAntiAlias = false) |
| 2322 | |
| 2323 | Replace Clip with the intersection of Clip and rect. |
| 2324 | Resulting Clip is aliased; pixels are fully contained by the clip. |
| 2325 | rect is transformed by Matrix |
| 2326 | before it is combined with Clip. |
| 2327 | |
| 2328 | #Param rect Rectangle to combine with Clip. ## |
| 2329 | #Param doAntiAlias true if Clip is to be anti-aliased. ## |
| 2330 | |
| 2331 | #Example |
| 2332 | #Height 133 |
| 2333 | #Description |
| 2334 | A circle drawn in pieces looks uniform when drawn aliased. |
| 2335 | The same circle pieces blend with pixels more than once when anti-aliased, |
| 2336 | visible as a thin pair of lines through the right circle. |
| 2337 | ## |
| 2338 | void draw(SkCanvas* canvas) {
|
| 2339 | canvas->clear(SK_ColorWHITE);
|
| 2340 | SkPaint paint;
|
| 2341 | paint.setAntiAlias(true);
|
| 2342 | paint.setColor(0x8055aaff);
|
| 2343 | SkRect clipRect = { 0, 0, 87.4f, 87.4f };
|
| 2344 | for (auto alias: { false, true } ) {
|
| 2345 | canvas->save();
|
| 2346 | canvas->clipRect(clipRect, SkClipOp::kIntersect, alias);
|
| 2347 | canvas->drawCircle(67, 67, 60, paint);
|
| 2348 | canvas->restore();
|
| 2349 | canvas->save();
|
| 2350 | canvas->clipRect(clipRect, SkClipOp::kDifference, alias);
|
| 2351 | canvas->drawCircle(67, 67, 60, paint);
|
| 2352 | canvas->restore();
|
| 2353 | canvas->translate(120, 0);
|
| 2354 | }
|
| 2355 | } |
| 2356 | ## |
| 2357 | |
| 2358 | #ToDo incomplete ## |
| 2359 | |
| 2360 | ## |
| 2361 | |
| 2362 | #Method void androidFramework_setDeviceClipRestriction(const SkIRect& rect) |
| 2363 | |
| 2364 | Sets the max clip rectangle, which can be set by clipRect, clipRRect and |
| 2365 | clipPath and intersect the current clip with the specified rect. |
| 2366 | The max clip affects only future ops (it is not retroactive). |
| 2367 | The clip restriction is not recorded in pictures. |
| 2368 | |
| 2369 | #Private |
| 2370 | This is private API to be used only by Android framework. |
| 2371 | ## |
| 2372 | |
| 2373 | #Param rect The maximum allowed clip in device coordinates. |
| 2374 | Empty rect means max clip is not enforced. ## |
| 2375 | |
| 2376 | ## |
| 2377 | |
| 2378 | #Method void clipRRect(const SkRRect& rrect, SkClipOp op, bool doAntiAlias) |
| 2379 | |
| 2380 | Replace Clip with the intersection or difference of Clip and rrect, |
| 2381 | with an aliased or anti-aliased clip edge. |
| 2382 | rrect is transformed by Matrix |
| 2383 | before it is combined with Clip. |
| 2384 | |
| 2385 | #Param rrect Round_Rect to combine with Clip. ## |
| 2386 | #Param op Clip_Op to apply to Clip. ## |
| 2387 | #Param doAntiAlias true if Clip is to be antialiased. ## |
| 2388 | |
| 2389 | #Example |
| 2390 | #Height 128 |
| 2391 | void draw(SkCanvas* canvas) {
|
| 2392 | canvas->clear(SK_ColorWHITE);
|
| 2393 | SkPaint paint;
|
| 2394 | paint.setAntiAlias(true);
|
| 2395 | paint.setColor(0x8055aaff);
|
| 2396 | SkRRect oval;
|
| 2397 | oval.setOval({10, 20, 90, 100});
|
| 2398 | canvas->clipRRect(oval, SkClipOp::kIntersect, true);
|
| 2399 | canvas->drawCircle(70, 100, 60, paint);
|
| 2400 | } |
| 2401 | ## |
| 2402 | |
| 2403 | #ToDo incomplete ## |
| 2404 | |
| 2405 | ## |
| 2406 | |
| 2407 | #Method void clipRRect(const SkRRect& rrect, SkClipOp op) |
| 2408 | |
| 2409 | Replace Clip with the intersection or difference of Clip and rrect. |
| 2410 | Resulting Clip is aliased; pixels are fully contained by the clip. |
| 2411 | rrect is transformed by Matrix |
| 2412 | before it is combined with Clip. |
| 2413 | |
| 2414 | #Param rrect Round_Rect to combine with Clip. ## |
| 2415 | #Param op Clip_Op to apply to Clip. ## |
| 2416 | |
| 2417 | #Example |
| 2418 | #Height 128 |
| 2419 | void draw(SkCanvas* canvas) {
|
| 2420 | SkPaint paint;
|
| 2421 | paint.setColor(0x8055aaff);
|
| 2422 | auto oval = SkRRect::MakeOval({10, 20, 90, 100});
|
| 2423 | canvas->clipRRect(oval, SkClipOp::kIntersect);
|
| 2424 | canvas->drawCircle(70, 100, 60, paint);
|
| 2425 | } |
| 2426 | ## |
| 2427 | |
| 2428 | #ToDo incomplete ## |
| 2429 | |
| 2430 | ## |
| 2431 | |
| 2432 | #Method void clipRRect(const SkRRect& rrect, bool doAntiAlias = false) |
| 2433 | |
| 2434 | Replace Clip with the intersection of Clip and rrect, |
| 2435 | with an aliased or anti-aliased clip edge. |
| 2436 | rrect is transformed by Matrix |
| 2437 | before it is combined with Clip. |
| 2438 | |
| 2439 | #Param rrect Round_Rect to combine with Clip. ## |
| 2440 | #Param doAntiAlias true if Clip is to be antialiased. ## |
| 2441 | |
| 2442 | #Example |
| 2443 | #Height 128 |
| 2444 | void draw(SkCanvas* canvas) {
|
| 2445 | SkPaint paint;
|
| 2446 | paint.setAntiAlias(true);
|
| 2447 | auto oval = SkRRect::MakeRectXY({10, 20, 90, 100}, 9, 13);
|
| 2448 | canvas->clipRRect(oval, true);
|
| 2449 | canvas->drawCircle(70, 100, 60, paint);
|
| 2450 | } |
| 2451 | ## |
| 2452 | |
| 2453 | #ToDo incomplete ## |
| 2454 | |
| 2455 | ## |
| 2456 | |
| 2457 | #Method void clipPath(const SkPath& path, SkClipOp op, bool doAntiAlias) |
| 2458 | |
| 2459 | Replace Clip with the intersection or difference of Clip and path, |
| 2460 | with an aliased or anti-aliased clip edge. Path_Fill_Type determines if path |
| 2461 | describes the area inside or outside its contours; and if Path_Contour overlaps |
| 2462 | itself or another Path_Contour, whether the overlaps form part of the area. |
| 2463 | path is transformed by Matrix |
| 2464 | before it is combined with Clip. |
| 2465 | |
| 2466 | #Param path Path to combine with Clip. ## |
| 2467 | #Param op Clip_Op to apply to Clip. ## |
| 2468 | #Param doAntiAlias true if Clip is to be antialiased. ## |
| 2469 | |
| 2470 | #Example |
| 2471 | #Description |
| 2472 | Top figure uses SkPath::kInverseWinding_FillType and SkClipOp::kDifference; |
| 2473 | area outside clip is subtracted from circle. |
| 2474 | |
| 2475 | Bottom figure uses SkPath::kWinding_FillType and SkClipOp::kIntersect; |
| 2476 | area inside clip is intersected with circle. |
| 2477 | ## |
| 2478 | void draw(SkCanvas* canvas) {
|
| 2479 | SkPaint paint;
|
| 2480 | paint.setAntiAlias(true);
|
| 2481 | SkPath path;
|
| 2482 | path.addRect({20, 30, 100, 110});
|
| 2483 | path.setFillType(SkPath::kInverseWinding_FillType);
|
| 2484 | canvas->save();
|
| 2485 | canvas->clipPath(path, SkClipOp::kDifference, false);
|
| 2486 | canvas->drawCircle(70, 100, 60, paint);
|
| 2487 | canvas->restore();
|
| 2488 | canvas->translate(100, 100);
|
| 2489 | path.setFillType(SkPath::kWinding_FillType);
|
| 2490 | canvas->clipPath(path, SkClipOp::kIntersect, false);
|
| 2491 | canvas->drawCircle(70, 100, 60, paint);
|
| 2492 | } |
| 2493 | ## |
| 2494 | |
| 2495 | #ToDo incomplete ## |
| 2496 | |
| 2497 | ## |
| 2498 | |
| 2499 | #Method void clipPath(const SkPath& path, SkClipOp op) |
| 2500 | |
| 2501 | Replace Clip with the intersection or difference of Clip and path. |
| 2502 | Resulting Clip is aliased; pixels are fully contained by the clip. |
| 2503 | Path_Fill_Type determines if path |
| 2504 | describes the area inside or outside its contours; and if Path_Contour overlaps |
| 2505 | itself or another Path_Contour, whether the overlaps form part of the area. |
| 2506 | path is transformed by Matrix |
| 2507 | before it is combined with Clip. |
| 2508 | |
| 2509 | #Param path Path to combine with Clip. ## |
| 2510 | #Param op Clip_Op to apply to Clip. ## |
| 2511 | |
| 2512 | #Example |
| 2513 | #Description |
| 2514 | Overlapping Rects form a clip. When clip's Path_Fill_Type is set to |
| 2515 | SkPath::kWinding_FillType, the overlap is included. Set to |
| 2516 | SkPath::kEvenOdd_FillType, the overlap is excluded and forms a hole. |
| 2517 | ## |
| 2518 | void draw(SkCanvas* canvas) {
|
| 2519 | SkPaint paint;
|
| 2520 | paint.setAntiAlias(true);
|
| 2521 | SkPath path;
|
| 2522 | path.addRect({20, 15, 100, 95});
|
| 2523 | path.addRect({50, 65, 130, 135});
|
| 2524 | path.setFillType(SkPath::kWinding_FillType);
|
| 2525 | canvas->save();
|
| 2526 | canvas->clipPath(path, SkClipOp::kIntersect);
|
| 2527 | canvas->drawCircle(70, 85, 60, paint);
|
| 2528 | canvas->restore();
|
| 2529 | canvas->translate(100, 100);
|
| 2530 | path.setFillType(SkPath::kEvenOdd_FillType);
|
| 2531 | canvas->clipPath(path, SkClipOp::kIntersect);
|
| 2532 | canvas->drawCircle(70, 85, 60, paint);
|
| 2533 | } |
| 2534 | ## |
| 2535 | |
| 2536 | #ToDo incomplete ## |
| 2537 | |
| 2538 | ## |
| 2539 | |
| 2540 | #Method void clipPath(const SkPath& path, bool doAntiAlias = false) |
| 2541 | |
| 2542 | Replace Clip with the intersection of Clip and path. |
| 2543 | Resulting Clip is aliased; pixels are fully contained by the clip. |
| 2544 | Path_Fill_Type determines if path |
| 2545 | describes the area inside or outside its contours; and if Path_Contour overlaps |
| 2546 | itself or another Path_Contour, whether the overlaps form part of the area. |
| 2547 | path is transformed by Matrix |
| 2548 | before it is combined with Clip. |
| 2549 | |
| 2550 | #Param path Path to combine with Clip. ## |
| 2551 | #Param doAntiAlias true if Clip is to be antialiased. ## |
| 2552 | |
| 2553 | #Example |
| 2554 | #Height 212 |
| 2555 | #Description |
| 2556 | Clip loops over itself covering its center twice. When clip's Path_Fill_Type |
| 2557 | is set to SkPath::kWinding_FillType, the overlap is included. Set to |
| 2558 | SkPath::kEvenOdd_FillType, the overlap is excluded and forms a hole. |
| 2559 | ## |
| 2560 | void draw(SkCanvas* canvas) {
|
| 2561 | SkPaint paint;
|
| 2562 | paint.setAntiAlias(true);
|
| 2563 | SkPath path;
|
| 2564 | SkPoint poly[] = {{20, 20}, { 80, 20}, { 80, 80}, {40, 80},
|
| 2565 | {40, 40}, {100, 40}, {100, 100}, {20, 100}};
|
| 2566 | path.addPoly(poly, SK_ARRAY_COUNT(poly), true);
|
| 2567 | path.setFillType(SkPath::kWinding_FillType);
|
| 2568 | canvas->save();
|
| 2569 | canvas->clipPath(path, SkClipOp::kIntersect);
|
| 2570 | canvas->drawCircle(50, 50, 45, paint);
|
| 2571 | canvas->restore();
|
| 2572 | canvas->translate(100, 100);
|
| 2573 | path.setFillType(SkPath::kEvenOdd_FillType);
|
| 2574 | canvas->clipPath(path, SkClipOp::kIntersect);
|
| 2575 | canvas->drawCircle(50, 50, 45, paint);
|
| 2576 | } |
| 2577 | ## |
| 2578 | |
| 2579 | #ToDo incomplete ## |
| 2580 | |
| 2581 | ## |
| 2582 | |
| 2583 | # ------------------------------------------------------------------------------ |
| 2584 | |
| 2585 | #Method void setAllowSimplifyClip(bool allow) |
| 2586 | |
| 2587 | #Experimental |
| 2588 | Only used for testing. |
| 2589 | ## |
| 2590 | |
| 2591 | Set to simplify clip stack using path ops. |
| 2592 | |
| 2593 | ## |
| 2594 | |
| 2595 | # ------------------------------------------------------------------------------ |
| 2596 | |
| 2597 | #Method void clipRegion(const SkRegion& deviceRgn, SkClipOp op = SkClipOp::kIntersect) |
| 2598 | |
| 2599 | Replace Clip with the intersection or difference of Clip and Region deviceRgn. |
| 2600 | Resulting Clip is aliased; pixels are fully contained by the clip. |
| 2601 | deviceRgn is unaffected by Matrix. |
| 2602 | |
| 2603 | #Param deviceRgn Region to combine with Clip. ## |
| 2604 | #Param op Clip_Op to apply to Clip. ## |
| 2605 | |
| 2606 | #Example |
| 2607 | #Description
|
| 2608 | region is unaffected by canvas rotation; rect is affected by canvas rotation.
|
| 2609 | Both clips are aliased; this is unnoticable on Region clip because it
|
| 2610 | aligns to pixel boundaries.
|
| 2611 | ##
|
| 2612 | void draw(SkCanvas* canvas) {
|
| 2613 | SkPaint paint;
|
| 2614 | paint.setAntiAlias(true);
|
| 2615 | SkIRect iRect = {30, 40, 120, 130 };
|
| 2616 | SkRegion region(iRect);
|
| 2617 | canvas->rotate(10);
|
| 2618 | canvas->save();
|
| 2619 | canvas->clipRegion(region, SkClipOp::kIntersect);
|
| 2620 | canvas->drawCircle(50, 50, 45, paint);
|
| 2621 | canvas->restore();
|
| 2622 | canvas->translate(100, 100);
|
| 2623 | canvas->clipRect(SkRect::Make(iRect), SkClipOp::kIntersect);
|
| 2624 | canvas->drawCircle(50, 50, 45, paint);
|
| 2625 | } |
| 2626 | ## |
| 2627 | |
| 2628 | #ToDo incomplete ## |
| 2629 | |
| 2630 | ## |
| 2631 | |
| 2632 | #Method bool quickReject(const SkRect& rect) const |
| 2633 | |
| 2634 | Return true if Rect rect, transformed by Matrix, can be quickly determined to be |
| 2635 | outside of Clip. May return false even though rect is outside of Clip. |
| 2636 | |
| 2637 | Use to check if an area to be drawn is clipped out, to skip subsequent draw calls. |
| 2638 | |
| 2639 | #Param rect Rect to compare with Clip. ## |
| 2640 | |
| 2641 | #Return true if rect, transformed by Matrix, does not intersect Clip. ## |
| 2642 | |
| 2643 | #Example |
| 2644 | void draw(SkCanvas* canvas) {
|
| 2645 | SkRect testRect = {30, 30, 120, 129 };
|
| 2646 | SkRect clipRect = {30, 130, 120, 230 };
|
| 2647 | canvas->save();
|
| 2648 | canvas->clipRect(clipRect);
|
| 2649 | SkDebugf("quickReject %s\n", canvas->quickReject(testRect) ? "true" : "false");
|
| 2650 | canvas->restore();
|
| 2651 | canvas->rotate(10);
|
| 2652 | canvas->clipRect(clipRect);
|
| 2653 | SkDebugf("quickReject %s\n", canvas->quickReject(testRect) ? "true" : "false");
|
| 2654 | } |
| 2655 | #StdOut |
| 2656 | quickReject true
|
| 2657 | quickReject false |
| 2658 | ## |
| 2659 | ## |
| 2660 | |
| 2661 | #ToDo incomplete ## |
| 2662 | |
| 2663 | ## |
| 2664 | |
| 2665 | #Method bool quickReject(const SkPath& path) const |
| 2666 | |
| 2667 | Return true if path, transformed by Matrix, can be quickly determined to be |
| 2668 | outside of Clip. May return false even though path is outside of Clip. |
| 2669 | |
| 2670 | Use to check if an area to be drawn is clipped out, to skip subsequent draw calls. |
| 2671 | |
| 2672 | #Param path Path to compare with Clip. ## |
| 2673 | |
| 2674 | #Return true if path, transformed by Matrix, does not intersect Clip. ## |
| 2675 | |
| 2676 | #Example |
| 2677 | void draw(SkCanvas* canvas) {
|
| 2678 | SkPoint testPoints[] = {{30, 30}, {120, 30}, {120, 129} };
|
| 2679 | SkPoint clipPoints[] = {{30, 130}, {120, 130}, {120, 230} };
|
| 2680 | SkPath testPath, clipPath;
|
| 2681 | testPath.addPoly(testPoints, SK_ARRAY_COUNT(testPoints), true);
|
| 2682 | clipPath.addPoly(clipPoints, SK_ARRAY_COUNT(clipPoints), true);
|
| 2683 | canvas->save();
|
| 2684 | canvas->clipPath(clipPath);
|
| 2685 | SkDebugf("quickReject %s\n", canvas->quickReject(testPath) ? "true" : "false");
|
| 2686 | canvas->restore();
|
| 2687 | canvas->rotate(10);
|
| 2688 | canvas->clipPath(clipPath);
|
| 2689 | SkDebugf("quickReject %s\n", canvas->quickReject(testPath) ? "true" : "false");
|
| 2690 | #StdOut |
| 2691 | quickReject true
|
| 2692 | quickReject false |
| 2693 | ## |
| 2694 | } |
| 2695 | ## |
| 2696 | |
| 2697 | #ToDo incomplete ## |
| 2698 | |
| 2699 | ## |
| 2700 | |
| 2701 | #Method SkRect getLocalClipBounds() const |
| 2702 | |
| 2703 | Return bounds of Clip, transformed by inverse of Matrix. If Clip is empty, |
| 2704 | return SkRect::MakeEmpty, where all Rect sides equal zero. |
| 2705 | |
| 2706 | Rect returned is outset by one to account for partial pixel coverage if Clip |
| 2707 | is anti-aliased. |
| 2708 | |
| 2709 | #Return bounds of Clip in local coordinates. ## |
| 2710 | |
| 2711 | #Example |
| 2712 | #Description |
| 2713 | Initial bounds is device bounds outset by 1 on all sides. |
| 2714 | Clipped bounds is clipPath bounds outset by 1 on all sides. |
| 2715 | Scaling the canvas by two in x and y scales the local bounds by 1/2 in x and y. |
| 2716 | ## |
| 2717 | SkCanvas local(256, 256);
|
| 2718 | canvas = &local;
|
| 2719 | SkRect bounds = canvas->getLocalClipBounds();
|
| 2720 | SkDebugf("left:%g top:%g right:%g bottom:%g\n",
|
| 2721 | bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
|
| 2722 | SkPoint clipPoints[] = {{30, 130}, {120, 130}, {120, 230} };
|
| 2723 | SkPath clipPath;
|
| 2724 | clipPath.addPoly(clipPoints, SK_ARRAY_COUNT(clipPoints), true);
|
| 2725 | canvas->clipPath(clipPath);
|
| 2726 | bounds = canvas->getLocalClipBounds();
|
| 2727 | SkDebugf("left:%g top:%g right:%g bottom:%g\n",
|
| 2728 | bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
|
| 2729 | canvas->scale(2, 2);
|
| 2730 | bounds = canvas->getLocalClipBounds();
|
| 2731 | SkDebugf("left:%g top:%g right:%g bottom:%g\n",
|
| 2732 | bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
|
| 2733 | #StdOut
|
| 2734 | left:-1 top:-1 right:257 bottom:257
|
| 2735 | left:29 top:129 right:121 bottom:231
|
| 2736 | left:14.5 top:64.5 right:60.5 bottom:115.5
|
| 2737 | ##
|
| 2738 | ## |
| 2739 | |
| 2740 | # local canvas in example works around bug in fiddle ## |
| 2741 | #Bug 6524 ## |
| 2742 | |
| 2743 | ## |
| 2744 | |
| 2745 | #Method bool getLocalClipBounds(SkRect* bounds) const |
| 2746 | |
| 2747 | Return bounds of Clip, transformed by inverse of Matrix. If Clip is empty, |
| 2748 | return false, and set bounds to SkRect::MakeEmpty, where all Rect sides equal zero. |
| 2749 | |
| 2750 | bounds is outset by one to account for partial pixel coverage if Clip |
| 2751 | is anti-aliased. |
| 2752 | |
| 2753 | #Param bounds Rect of Clip in local coordinates. ## |
| 2754 | |
| 2755 | #Return true if Clip bounds is not empty. ## |
| 2756 | |
| 2757 | #Example |
| 2758 | void draw(SkCanvas* canvas) {
|
| 2759 | SkCanvas local(256, 256);
|
| 2760 | canvas = &local;
|
| 2761 | SkRect bounds;
|
| 2762 | SkDebugf("local bounds empty = %s\n", canvas->getLocalClipBounds(&bounds)
|
| 2763 | ? "false" : "true");
|
| 2764 | SkPath path;
|
| 2765 | canvas->clipPath(path);
|
| 2766 | SkDebugf("local bounds empty = %s\n", canvas->getLocalClipBounds(&bounds)
|
| 2767 | ? "false" : "true");
|
| 2768 | } |
| 2769 | #StdOut |
| 2770 | local bounds empty = false
|
| 2771 | local bounds empty = true |
| 2772 | ## |
| 2773 | ## |
| 2774 | |
| 2775 | # local canvas in example works around bug in fiddle ## |
| 2776 | #Bug 6524 ## |
| 2777 | |
| 2778 | ## |
| 2779 | |
| 2780 | #Method SkIRect getDeviceClipBounds() const |
| 2781 | |
| 2782 | Return IRect bounds of Clip, unaffected by Matrix. If Clip is empty, |
| 2783 | return SkRect::MakeEmpty, where all Rect sides equal zero. |
| 2784 | |
| 2785 | Unlike getLocalClipBounds, returned IRect is not outset. |
| 2786 | |
| 2787 | #Return bounds of Clip in Device coordinates. ## |
| 2788 | |
| 2789 | #Example |
| 2790 | void draw(SkCanvas* canvas) {
|
| 2791 | #Description
|
| 2792 | Initial bounds is device bounds, not outset. |
| 2793 | Clipped bounds is clipPath bounds, not outset. |
| 2794 | Scaling the canvas by 1/2 in x and y scales the device bounds by 1/2 in x and y. |
| 2795 | ##
|
| 2796 | SkCanvas device(256, 256);
|
| 2797 | canvas = &device;
|
| 2798 | SkIRect bounds = canvas->getDeviceClipBounds();
|
| 2799 | SkDebugf("left:%d top:%d right:%d bottom:%d\n",
|
| 2800 | bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
|
| 2801 | SkPoint clipPoints[] = {{30, 130}, {120, 130}, {120, 230} };
|
| 2802 | SkPath clipPath;
|
| 2803 | clipPath.addPoly(clipPoints, SK_ARRAY_COUNT(clipPoints), true);
|
| 2804 | canvas->save();
|
| 2805 | canvas->clipPath(clipPath);
|
| 2806 | bounds = canvas->getDeviceClipBounds();
|
| 2807 | SkDebugf("left:%d top:%d right:%d bottom:%d\n",
|
| 2808 | bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
|
| 2809 | canvas->restore();
|
| 2810 | canvas->scale(1.f/2, 1.f/2);
|
| 2811 | canvas->clipPath(clipPath);
|
| 2812 | bounds = canvas->getDeviceClipBounds();
|
| 2813 | SkDebugf("left:%d top:%d right:%d bottom:%d\n",
|
| 2814 | bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
|
| 2815 | #StdOut |
| 2816 | left:0 top:0 right:256 bottom:256
|
| 2817 | left:30 top:130 right:120 bottom:230
|
| 2818 | left:15 top:65 right:60 bottom:115 |
| 2819 | ## |
| 2820 | } |
| 2821 | ## |
| 2822 | |
| 2823 | #ToDo some confusion on why with an identity Matrix local and device are different ## |
| 2824 | |
| 2825 | # device canvas in example works around bug in fiddle ## |
| 2826 | #Bug 6524 ## |
| 2827 | |
| 2828 | ## |
| 2829 | |
| 2830 | #Method bool getDeviceClipBounds(SkIRect* bounds) const |
| 2831 | |
| 2832 | Return IRect bounds of Clip, unaffected by Matrix. If Clip is empty, |
| 2833 | return false, and set bounds to SkRect::MakeEmpty, where all Rect sides equal zero. |
| 2834 | |
| 2835 | Unlike getLocalClipBounds, bounds is not outset. |
| 2836 | |
| 2837 | #Param bounds Rect of Clip in device coordinates. ## |
| 2838 | |
| 2839 | #Return true if Clip bounds is not empty. ## |
| 2840 | |
| 2841 | #Example |
| 2842 | void draw(SkCanvas* canvas) {
|
| 2843 | SkIRect bounds;
|
| 2844 | SkDebugf("device bounds empty = %s\n", canvas->getDeviceClipBounds(&bounds)
|
| 2845 | ? "false" : "true");
|
| 2846 | SkPath path;
|
| 2847 | canvas->clipPath(path);
|
| 2848 | SkDebugf("device bounds empty = %s\n", canvas->getDeviceClipBounds(&bounds)
|
| 2849 | ? "false" : "true");
|
| 2850 | } |
| 2851 | #StdOut |
| 2852 | device bounds empty = false
|
| 2853 | device bounds empty = true |
| 2854 | ## |
| 2855 | ## |
| 2856 | |
| 2857 | #ToDo incomplete ## |
| 2858 | |
| 2859 | ## |
| 2860 | |
| 2861 | #Topic Clip ## |
| 2862 | |
| 2863 | # ------------------------------------------------------------------------------ |
| 2864 | |
| 2865 | #Method void drawColor(SkColor color, SkBlendMode mode = SkBlendMode::kSrcOver) |
| 2866 | |
| 2867 | Fill Clip with Color color. |
| 2868 | mode determines how Color_ARGB is combined with destination. |
| 2869 | |
| 2870 | #Param color Unpremultiplied Color_ARGB. ## |
| 2871 | #Param mode SkBlendMode used to combine source color and destination. ## |
| 2872 | |
| 2873 | #Example |
| 2874 | canvas->drawColor(SK_ColorRED);
|
| 2875 | canvas->clipRect(SkRect::MakeWH(150, 150));
|
| 2876 | canvas->drawColor(SkColorSetARGB(0x80, 0x00, 0xFF, 0x00), SkBlendMode::kPlus);
|
| 2877 | canvas->clipRect(SkRect::MakeWH(75, 75));
|
| 2878 | canvas->drawColor(SkColorSetARGB(0x80, 0x00, 0x00, 0xFF), SkBlendMode::kPlus);
|
| 2879 | ## |
| 2880 | |
| 2881 | #ToDo incomplete ## |
| 2882 | |
| 2883 | ## |
| 2884 | |
| 2885 | # ------------------------------------------------------------------------------ |
| 2886 | |
| 2887 | #Method void clear(SkColor color) |
| 2888 | |
| 2889 | Fill Clip with Color color using SkBlendMode::kSrc. |
| 2890 | This has the effect of replacing all pixels contained by Clip with color. |
| 2891 | |
| 2892 | #Param color Unpremultiplied Color_ARGB. ## |
| 2893 | |
| 2894 | #Example |
| 2895 | void draw(SkCanvas* canvas) {
|
| 2896 | canvas->save();
|
| 2897 | canvas->clipRect(SkRect::MakeWH(256, 128));
|
| 2898 | canvas->clear(SkColorSetARGB(0x80, 0xFF, 0x00, 0x00));
|
| 2899 | canvas->restore();
|
| 2900 | canvas->save();
|
| 2901 | canvas->clipRect(SkRect::MakeWH(150, 192));
|
| 2902 | canvas->clear(SkColorSetARGB(0x80, 0x00, 0xFF, 0x00));
|
| 2903 | canvas->restore();
|
| 2904 | canvas->clipRect(SkRect::MakeWH(75, 256));
|
| 2905 | canvas->clear(SkColorSetARGB(0x80, 0x00, 0x00, 0xFF));
|
| 2906 | } |
| 2907 | ## |
| 2908 | |
| 2909 | #ToDo incomplete ## |
| 2910 | |
| 2911 | ## |
| 2912 | |
| 2913 | # ------------------------------------------------------------------------------ |
| 2914 | |
| 2915 | #Method void discard() |
| 2916 | |
| 2917 | Make Canvas contents undefined. Subsequent calls that read Canvas pixels, |
| 2918 | such as drawing with SkBlendMode, return undefined results. discard() does |
| 2919 | not change Clip or Matrix. |
| 2920 | |
| 2921 | discard() may do nothing, depending on the implementation of Surface or Device |
| 2922 | that created Canvas. |
| 2923 | |
| 2924 | discard() allows optimized performance on subsequent draws by removing |
| 2925 | cached data associated with Surface or Device. |
| 2926 | It is not necessary to call discard() once done with Canvas; |
| 2927 | any cached data is deleted when owning Surface or Device is deleted. |
| 2928 | |
| 2929 | #ToDo example? not sure how to make this meaningful w/o more implementation detail ## |
| 2930 | |
| 2931 | #NoExample |
| 2932 | ## |
| 2933 | |
| 2934 | ## |
| 2935 | |
| 2936 | # ------------------------------------------------------------------------------ |
| 2937 | |
| 2938 | #Method void drawPaint(const SkPaint& paint) |
| 2939 | |
| 2940 | Fill Clip with Paint paint. drawPaint is affected by Paint components |
| 2941 | Rasterizer, Mask_Filter, Shader, Color_Filter, Image_Filter, and Blend_Mode; but not by |
| 2942 | Path_Effect. |
| 2943 | |
| 2944 | # can Path_Effect in paint ever alter drawPaint? |
| 2945 | |
| 2946 | #Param paint Used to fill the canvas. ## |
| 2947 | |
| 2948 | #Example |
| 2949 | void draw(SkCanvas* canvas) {
|
| 2950 | SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
|
| 2951 | SkScalar pos[] = { 0, SK_Scalar1/2, SK_Scalar1 };
|
| 2952 | SkPaint paint;
|
| 2953 | paint.setShader(SkGradientShader::MakeSweep(256, 256, colors, pos, SK_ARRAY_COUNT(colors)));
|
| 2954 | canvas->drawPaint(paint);
|
| 2955 | } |
| 2956 | ## |
| 2957 | |
| 2958 | #ToDo incomplete ## |
| 2959 | |
| 2960 | ## |
| 2961 | |
| 2962 | # ------------------------------------------------------------------------------ |
| 2963 | |
| 2964 | #Enum PointMode |
| 2965 | |
| 2966 | #Code |
| 2967 | enum PointMode { |
| 2968 | kPoints_PointMode, |
| 2969 | kLines_PointMode, |
| 2970 | kPolygon_PointMode |
| 2971 | }; |
| 2972 | ## |
| 2973 | |
| 2974 | Selects if an array of points are drawn as discrete points, as lines, or as |
| 2975 | an open polygon. |
| 2976 | |
| 2977 | #Const kPoints_PointMode 0 |
| 2978 | Draw each point separately. |
| 2979 | ## |
| 2980 | |
| 2981 | #Const kLines_PointMode 1 |
| 2982 | Draw each pair of points as a line segment. |
| 2983 | ## |
| 2984 | |
| 2985 | #Const kPolygon_PointMode 2 |
| 2986 | Draw the array of points as a open polygon. |
| 2987 | ## |
| 2988 | |
| 2989 | #Example |
| 2990 | #Description |
| 2991 | The upper left corner shows three squares when drawn as points. |
| 2992 | The upper right corner shows one line; when drawn as lines, two points are required per line. |
| 2993 | The lower right corner shows two lines; when draw as polygon, no miter is drawn at the corner. |
| 2994 | The lower left corner shows two lines with a miter when path contains polygon. |
| 2995 | ## |
| 2996 | void draw(SkCanvas* canvas) {
|
| 2997 | SkPaint paint;
|
| 2998 | paint.setStyle(SkPaint::kStroke_Style);
|
| 2999 | paint.setStrokeWidth(10);
|
| 3000 | SkPoint points[] = {{64, 32}, {96, 96}, {32, 96}};
|
| 3001 | canvas->drawPoints(SkCanvas::kPoints_PointMode, 3, points, paint);
|
| 3002 | canvas->translate(128, 0);
|
| 3003 | canvas->drawPoints(SkCanvas::kLines_PointMode, 3, points, paint);
|
| 3004 | canvas->translate(0, 128);
|
| 3005 | canvas->drawPoints(SkCanvas::kPolygon_PointMode, 3, points, paint);
|
| 3006 | SkPath path;
|
| 3007 | path.addPoly(points, 3, false);
|
| 3008 | canvas->translate(-128, 0);
|
| 3009 | canvas->drawPath(path, paint);
|
| 3010 | } |
| 3011 | ## |
| 3012 | |
| 3013 | #ToDo incomplete ## |
| 3014 | |
| 3015 | ## |
| 3016 | |
| 3017 | # ------------------------------------------------------------------------------ |
| 3018 | |
| 3019 | #Method void drawPoints(PointMode mode, size_t count, const SkPoint pts[], const SkPaint& paint) |
| 3020 | |
| 3021 | Draw pts using Clip, Matrix and Paint paint. |
| 3022 | count is the number of points; if count is less than one, drawPoints has no effect. |
| 3023 | mode may be one of: kPoints_PointMode, kLines_PointMode, or kPolygon_PointMode. |
| 3024 | |
| 3025 | If mode is kPoints_PointMode, the shape of point drawn depends on paint Paint_Stroke_Cap. |
| 3026 | If paint is set to SkPaint::kRound_Cap, each point draws a circle of diameter Paint_Stroke_Width. |
| 3027 | If paint is set to SkPaint::kSquare_Cap or SkPaint::kButt_Cap, |
| 3028 | each point draws a square of width and height Paint_Stroke_Width. |
| 3029 | |
| 3030 | If mode is kLines_PointMode, each pair of points draws a line segment. |
| 3031 | One line is drawn for every two points; each point is used once. If count is odd, |
| 3032 | the final point is ignored. |
| 3033 | |
| 3034 | If mode is kPolygon_PointMode, each adjacent pair of points draws a line segment. |
| 3035 | count minus one lines are drawn; the first and last point are used once. |
| 3036 | |
| 3037 | Each line segment respects paint Paint_Stroke_Cap and Paint_Stroke_Width. |
| 3038 | Paint_Style is ignored, as if were set to SkPaint::kStroke_Style. |
| 3039 | |
| 3040 | drawPoints always draws each element one at a time; drawPoints is not affected by |
| 3041 | Paint_Stroke_Join, and unlike drawPath, does not create a mask from all points and lines |
| 3042 | before drawing. |
| 3043 | |
| 3044 | #Param mode Whether pts draws points or lines. ## |
| 3045 | #Param count The number of points in the array. ## |
| 3046 | #Param pts Array of points to draw. ## |
| 3047 | #Param paint Stroke, blend, color, and so on, used to draw. ## |
| 3048 | |
| 3049 | #Example |
| 3050 | #Height 200 |
| 3051 | #Description |
| 3052 | #List |
| 3053 | # The first column draws points. ## |
| 3054 | # The second column draws points as lines. ## |
| 3055 | # The third column draws points as a polygon. ## |
| 3056 | # The fourth column draws points as a polygonal path. ## |
| 3057 | # The first row uses a round cap and round join. ## |
| 3058 | # The second row uses a square cap and a miter join. ## |
| 3059 | # The third row uses a butt cap and a bevel join. ## |
| 3060 | ## |
| 3061 | The transparent color makes multiple line draws visible; |
| 3062 | the path is drawn all at once. |
| 3063 | ## |
| 3064 | void draw(SkCanvas* canvas) {
|
| 3065 | SkPaint paint;
|
| 3066 | paint.setAntiAlias(true);
|
| 3067 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3068 | paint.setStrokeWidth(10);
|
| 3069 | paint.setColor(0x80349a45);
|
| 3070 | const SkPoint points[] = {{32, 16}, {48, 48}, {16, 32}};
|
| 3071 | const SkPaint::Join join[] = { SkPaint::kRound_Join,
|
| 3072 | SkPaint::kMiter_Join,
|
| 3073 | SkPaint::kBevel_Join };
|
| 3074 | int joinIndex = 0;
|
| 3075 | SkPath path;
|
| 3076 | path.addPoly(points, 3, false);
|
| 3077 | for (const auto cap : { SkPaint::kRound_Cap, SkPaint::kSquare_Cap, SkPaint::kButt_Cap } ) {
|
| 3078 | paint.setStrokeCap(cap);
|
| 3079 | paint.setStrokeJoin(join[joinIndex++]);
|
| 3080 | for (const auto mode : { SkCanvas::kPoints_PointMode,
|
| 3081 | SkCanvas::kLines_PointMode,
|
| 3082 | SkCanvas::kPolygon_PointMode } ) {
|
| 3083 | canvas->drawPoints(mode, 3, points, paint);
|
| 3084 | canvas->translate(64, 0);
|
| 3085 | }
|
| 3086 | canvas->drawPath(path, paint);
|
| 3087 | canvas->translate(-192, 64);
|
| 3088 | }
|
| 3089 | } |
| 3090 | ## |
| 3091 | |
| 3092 | #ToDo incomplete ## |
| 3093 | |
| 3094 | ## |
| 3095 | |
| 3096 | # ------------------------------------------------------------------------------ |
| 3097 | |
| 3098 | #Method void drawPoint(SkScalar x, SkScalar y, const SkPaint& paint) |
| 3099 | |
| 3100 | Draw point at (x, y) using Clip, Matrix and Paint paint. |
| 3101 | |
| 3102 | The shape of point drawn depends on paint Paint_Stroke_Cap. |
| 3103 | If paint is set to SkPaint::kRound_Cap, draw a circle of diameter Paint_Stroke_Width. |
| 3104 | If paint is set to SkPaint::kSquare_Cap or SkPaint::kButt_Cap, |
| 3105 | draw a square of width and height Paint_Stroke_Width. |
| 3106 | Paint_Style is ignored, as if were set to SkPaint::kStroke_Style. |
| 3107 | |
| 3108 | #Param x Left edge of circle or square. ## |
| 3109 | #Param y Top edge of circle or square. ## |
| 3110 | #Param paint Stroke, blend, color, and so on, used to draw. ## |
| 3111 | |
| 3112 | #Example |
| 3113 | void draw(SkCanvas* canvas) {
|
| 3114 | SkPaint paint;
|
| 3115 | paint.setAntiAlias(true);
|
| 3116 | paint.setColor(0x80349a45);
|
| 3117 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3118 | paint.setStrokeWidth(100);
|
| 3119 | paint.setStrokeCap(SkPaint::kRound_Cap);
|
| 3120 | canvas->scale(1, 1.2f);
|
| 3121 | canvas->drawPoint(64, 96, paint);
|
| 3122 | canvas->scale(.6f, .8f);
|
| 3123 | paint.setColor(SK_ColorWHITE);
|
| 3124 | canvas->drawPoint(106, 120, paint);
|
| 3125 | } |
| 3126 | ## |
| 3127 | |
| 3128 | #ToDo incomplete ## |
| 3129 | |
| 3130 | ## |
| 3131 | |
| 3132 | # ------------------------------------------------------------------------------ |
| 3133 | |
| 3134 | #Method void drawLine(SkScalar x0, SkScalar y0, SkScalar x1, SkScalar y1, const SkPaint& paint) |
| 3135 | |
| 3136 | Draw line segment from (x0, y0) to (x1, y1) using Clip, Matrix, and Paint paint. |
| 3137 | In paint: Paint_Stroke_Width describes the line thickness; Paint_Stroke_Cap draws the end rounded or square; |
| 3138 | Paint_Style is ignored, as if were set to SkPaint::kStroke_Style. |
| 3139 | |
| 3140 | #Param x0 Start of line segment on x-axis. ## |
| 3141 | #Param y0 Start of line segment on y-axis. ## |
| 3142 | #Param x1 End of line segment on x-axis. ## |
| 3143 | #Param y1 End of line segment on y-axis. ## |
| 3144 | #Param paint Stroke, blend, color, and so on, used to draw. ## |
| 3145 | |
| 3146 | #Example |
| 3147 | SkPaint paint;
|
| 3148 | paint.setAntiAlias(true);
|
| 3149 | paint.setColor(0xFF9a67be);
|
| 3150 | paint.setStrokeWidth(20);
|
| 3151 | canvas->skew(1, 0);
|
| 3152 | canvas->drawLine(32, 96, 32, 160, paint);
|
| 3153 | canvas->skew(-2, 0);
|
| 3154 | canvas->drawLine(288, 96, 288, 160, paint);
|
| 3155 | ## |
| 3156 | |
| 3157 | #ToDo incomplete ## |
| 3158 | |
| 3159 | ## |
| 3160 | |
| 3161 | # ------------------------------------------------------------------------------ |
| 3162 | |
| 3163 | #Method void drawRect(const SkRect& rect, const SkPaint& paint) |
| 3164 | |
| 3165 | Draw Rect rect using Clip, Matrix, and Paint paint. |
| 3166 | In paint: Paint_Style determines if rectangle is stroked or filled; |
| 3167 | if stroked, Paint_Stroke_Width describes the line thickness, and |
| 3168 | Paint_Stroke_Join draws the corners rounded or square. |
| 3169 | |
| 3170 | #Param rect The rectangle to be drawn. ## |
| 3171 | #Param paint Stroke or fill, blend, color, and so on, used to draw. ## |
| 3172 | |
| 3173 | #Example |
| 3174 | void draw(SkCanvas* canvas) {
|
| 3175 | SkPoint rectPts[] = { {64, 48}, {192, 160} };
|
| 3176 | SkPaint paint;
|
| 3177 | paint.setAntiAlias(true);
|
| 3178 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3179 | paint.setStrokeWidth(20);
|
| 3180 | paint.setStrokeJoin(SkPaint::kRound_Join);
|
| 3181 | SkMatrix rotator;
|
| 3182 | rotator.setRotate(30, 128, 128);
|
| 3183 | for (auto color : { SK_ColorRED, SK_ColorBLUE, SK_ColorYELLOW, SK_ColorMAGENTA } ) {
|
| 3184 | paint.setColor(color);
|
| 3185 | SkRect rect;
|
| 3186 | rect.set(rectPts[0], rectPts[1]);
|
| 3187 | canvas->drawRect(rect, paint);
|
| 3188 | rotator.mapPoints(rectPts, 2);
|
| 3189 | }
|
| 3190 | } |
| 3191 | ## |
| 3192 | |
| 3193 | #ToDo incomplete ## |
| 3194 | |
| 3195 | ## |
| 3196 | |
| 3197 | # ------------------------------------------------------------------------------ |
| 3198 | |
| 3199 | #Method void drawIRect(const SkIRect& rect, const SkPaint& paint) |
| 3200 | |
| 3201 | Draw IRect rect using Clip, Matrix, and Paint paint. |
| 3202 | In paint: Paint_Style determines if rectangle is stroked or filled; |
| 3203 | if stroked, Paint_Stroke_Width describes the line thickness, and |
| 3204 | Paint_Stroke_Join draws the corners rounded or square. |
| 3205 | |
| 3206 | #Param rect The rectangle to be drawn. ## |
| 3207 | #Param paint Stroke or fill, blend, color, and so on, used to draw. ## |
| 3208 | |
| 3209 | #Example |
| 3210 | SkIRect rect = { 64, 48, 192, 160 };
|
| 3211 | SkPaint paint;
|
| 3212 | paint.setAntiAlias(true);
|
| 3213 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3214 | paint.setStrokeWidth(20);
|
| 3215 | paint.setStrokeJoin(SkPaint::kRound_Join);
|
| 3216 | for (auto color : { SK_ColorRED, SK_ColorBLUE, SK_ColorYELLOW, SK_ColorMAGENTA } ) {
|
| 3217 | paint.setColor(color);
|
| 3218 | canvas->drawIRect(rect, paint);
|
| 3219 | canvas->rotate(30, 128, 128);
|
| 3220 | }
|
| 3221 | ## |
| 3222 | |
| 3223 | #ToDo incomplete ## |
| 3224 | |
| 3225 | ## |
| 3226 | |
| 3227 | # ------------------------------------------------------------------------------ |
| 3228 | |
| 3229 | #Method void drawRegion(const SkRegion& region, const SkPaint& paint) |
| 3230 | |
| 3231 | Draw Region region using Clip, Matrix, and Paint paint. |
| 3232 | In paint: Paint_Style determines if rectangle is stroked or filled; |
| 3233 | if stroked, Paint_Stroke_Width describes the line thickness, and |
| 3234 | Paint_Stroke_Join draws the corners rounded or square. |
| 3235 | |
| 3236 | #Param region The region to be drawn. ## |
| 3237 | #Param paint Paint stroke or fill, blend, color, and so on, used to draw. ## |
| 3238 | |
| 3239 | #Example |
| 3240 | void draw(SkCanvas* canvas) {
|
| 3241 | SkRegion region;
|
| 3242 | region.op( 10, 10, 50, 50, SkRegion::kUnion_Op);
|
| 3243 | region.op( 10, 50, 90, 90, SkRegion::kUnion_Op);
|
| 3244 | SkPaint paint;
|
| 3245 | paint.setAntiAlias(true);
|
| 3246 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3247 | paint.setStrokeWidth(20);
|
| 3248 | paint.setStrokeJoin(SkPaint::kRound_Join);
|
| 3249 | canvas->drawRegion(region, paint);
|
| 3250 | } |
| 3251 | ## |
| 3252 | |
| 3253 | #ToDo incomplete ## |
| 3254 | |
| 3255 | ## |
| 3256 | |
| 3257 | # ------------------------------------------------------------------------------ |
| 3258 | |
| 3259 | #Method void drawOval(const SkRect& oval, const SkPaint& paint) |
| 3260 | |
| 3261 | Draw Oval oval using Clip, Matrix, and Paint. |
| 3262 | In paint: Paint_Style determines if Oval is stroked or filled; |
| 3263 | if stroked, Paint_Stroke_Width describes the line thickness. |
| 3264 | |
| 3265 | #Param oval Rect bounds of Oval. ## |
| 3266 | #Param paint Paint stroke or fill, blend, color, and so on, used to draw. ## |
| 3267 | |
| 3268 | #Example |
| 3269 | void draw(SkCanvas* canvas) {
|
| 3270 | canvas->clear(0xFF3f5f9f);
|
| 3271 | SkColor kColor1 = SkColorSetARGB(0xff, 0xff, 0x7f, 0);
|
| 3272 | SkColor g1Colors[] = { kColor1, SkColorSetA(kColor1, 0x20) };
|
| 3273 | SkPoint g1Points[] = { { 0, 0 }, { 0, 100 } };
|
| 3274 | SkScalar pos[] = { 0.2f, 1.0f };
|
| 3275 | SkRect bounds = SkRect::MakeWH(80, 70);
|
| 3276 | SkPaint paint;
|
| 3277 | paint.setAntiAlias(true);
|
| 3278 | paint.setShader(SkGradientShader::MakeLinear(g1Points, g1Colors, pos, SK_ARRAY_COUNT(g1Colors),
|
| 3279 | SkShader::kClamp_TileMode));
|
| 3280 | canvas->drawOval(bounds , paint);
|
| 3281 | } |
| 3282 | ## |
| 3283 | |
| 3284 | #ToDo incomplete ## |
| 3285 | |
| 3286 | ## |
| 3287 | |
| 3288 | # ------------------------------------------------------------------------------ |
| 3289 | |
| 3290 | #Method void drawRRect(const SkRRect& rrect, const SkPaint& paint) |
| 3291 | |
| 3292 | Draw Round_Rect rrect using Clip, Matrix, and Paint paint. |
| 3293 | In paint: Paint_Style determines if rrect is stroked or filled; |
| 3294 | if stroked, Paint_Stroke_Width describes the line thickness. |
| 3295 | |
| 3296 | rrect may represent a rectangle, circle, oval, uniformly rounded rectangle, or may have |
| 3297 | any combination of positive non-square radii for the four corners. |
| 3298 | |
| 3299 | #Param rrect Round_Rect with up to eight corner radii to draw. ## |
| 3300 | #Param paint Paint stroke or fill, blend, color, and so on, used to draw. ## |
| 3301 | |
| 3302 | #Example |
| 3303 | void draw(SkCanvas* canvas) {
|
| 3304 | SkPaint paint;
|
| 3305 | paint.setAntiAlias(true);
|
| 3306 | SkRect outer = {30, 40, 210, 220};
|
| 3307 | SkRect radii = {30, 50, 70, 90 };
|
| 3308 | SkRRect rRect;
|
| 3309 | rRect.setNinePatch(outer, radii.fLeft, radii.fTop, radii.fRight, radii.fBottom);
|
| 3310 | canvas->drawRRect(rRect, paint);
|
| 3311 | paint.setColor(SK_ColorWHITE);
|
| 3312 | canvas->drawLine(outer.fLeft + radii.fLeft, outer.fTop,
|
| 3313 | outer.fLeft + radii.fLeft, outer.fBottom, paint);
|
| 3314 | canvas->drawLine(outer.fRight - radii.fRight, outer.fTop,
|
| 3315 | outer.fRight - radii.fRight, outer.fBottom, paint);
|
| 3316 | canvas->drawLine(outer.fLeft, outer.fTop + radii.fTop,
|
| 3317 | outer.fRight, outer.fTop + radii.fTop, paint);
|
| 3318 | canvas->drawLine(outer.fLeft, outer.fBottom - radii.fBottom,
|
| 3319 | outer.fRight, outer.fBottom - radii.fBottom, paint);
|
| 3320 | }
|
| 3321 | ## |
| 3322 | |
| 3323 | #ToDo incomplete ## |
| 3324 | |
| 3325 | ## |
| 3326 | |
| 3327 | # ------------------------------------------------------------------------------ |
| 3328 | |
| 3329 | #Method void drawDRRect(const SkRRect& outer, const SkRRect& inner, const SkPaint& paint) |
| 3330 | |
| 3331 | Draw Round_Rect outer and inner |
| 3332 | using Clip, Matrix, and Paint paint. |
| 3333 | outer must contain inner or the drawing is undefined. |
| 3334 | In paint: Paint_Style determines if rrect is stroked or filled; |
| 3335 | if stroked, Paint_Stroke_Width describes the line thickness. |
| 3336 | If stroked and Round_Rect corner has zero length radii, Paint_Stroke_Join can draw |
| 3337 | corners rounded or square. |
| 3338 | |
| 3339 | GPU-backed platforms take advantage of drawDRRect since both outer and inner are |
| 3340 | concave and outer contains inner. These platforms may not be able to draw |
| 3341 | Path built with identical data as fast. |
| 3342 | |
| 3343 | #Param outer Round_Rect outer bounds to draw. ## |
| 3344 | #Param inner Round_Rect inner bounds to draw. ## |
| 3345 | #Param paint Paint stroke or fill, blend, color, and so on, used to draw. ## |
| 3346 | |
| 3347 | #Example |
| 3348 | void draw(SkCanvas* canvas) {
|
| 3349 | SkRRect outer = SkRRect::MakeRect({20, 40, 210, 200});
|
| 3350 | SkRRect inner = SkRRect::MakeOval({60, 70, 170, 160});
|
| 3351 | SkPaint paint;
|
| 3352 | canvas->drawDRRect(outer, inner, paint);
|
| 3353 | } |
| 3354 | ## |
| 3355 | |
| 3356 | #Example |
| 3357 | #Description |
| 3358 | Outer Rect has no corner radii, but stroke join is rounded. |
| 3359 | Inner Round_Rect has corner radii; outset stroke increases radii of corners. |
| 3360 | Stroke join does not affect inner Round_Rect since it has no sharp corners. |
| 3361 | ## |
| 3362 | void draw(SkCanvas* canvas) {
|
| 3363 | SkRRect outer = SkRRect::MakeRect({20, 40, 210, 200});
|
| 3364 | SkRRect inner = SkRRect::MakeRectXY({60, 70, 170, 160}, 10, 10);
|
| 3365 | SkPaint paint;
|
| 3366 | paint.setAntiAlias(true);
|
| 3367 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3368 | paint.setStrokeWidth(20);
|
| 3369 | paint.setStrokeJoin(SkPaint::kRound_Join);
|
| 3370 | canvas->drawDRRect(outer, inner, paint);
|
| 3371 | paint.setStrokeWidth(1);
|
| 3372 | paint.setColor(SK_ColorWHITE);
|
| 3373 | canvas->drawDRRect(outer, inner, paint);
|
| 3374 | } |
| 3375 | ## |
| 3376 | |
| 3377 | #ToDo incomplete ## |
| 3378 | |
| 3379 | ## |
| 3380 | |
| 3381 | # ------------------------------------------------------------------------------ |
| 3382 | |
| 3383 | #Method void drawCircle(SkScalar cx, SkScalar cy, SkScalar radius, const SkPaint& paint) |
| 3384 | |
| 3385 | Draw Circle at (cx, cy) with radius using Clip, Matrix, and Paint paint. |
| 3386 | If radius is zero or less, nothing is drawn. |
| 3387 | In paint: Paint_Style determines if Circle is stroked or filled; |
| 3388 | if stroked, Paint_Stroke_Width describes the line thickness. |
| 3389 | |
| 3390 | #Param cx Circle center on the x-axis. ## |
| 3391 | #Param cy Circle center on the y-axis. ## |
| 3392 | #Param radius Half the diameter of Circle. ## |
| 3393 | #Param paint Paint stroke or fill, blend, color, and so on, used to draw. ## |
| 3394 | |
| 3395 | #Example |
| 3396 | void draw(SkCanvas* canvas) {
|
| 3397 | SkPaint paint;
|
| 3398 | paint.setAntiAlias(true);
|
| 3399 | canvas->drawCircle(128, 128, 90, paint);
|
| 3400 | paint.setColor(SK_ColorWHITE);
|
| 3401 | canvas->drawCircle(86, 86, 20, paint);
|
| 3402 | canvas->drawCircle(160, 76, 20, paint);
|
| 3403 | canvas->drawCircle(140, 150, 35, paint);
|
| 3404 | }
|
| 3405 | ## |
| 3406 | |
| 3407 | #ToDo incomplete ## |
| 3408 | |
| 3409 | ## |
| 3410 | |
| 3411 | # ------------------------------------------------------------------------------ |
| 3412 | |
| 3413 | #Method void drawArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, |
| 3414 | bool useCenter, const SkPaint& paint) |
| 3415 | |
| 3416 | Draw Arc using Clip, Matrix, and Paint paint. |
| 3417 | Arc is part of Oval bounded by oval, sweeping from startAngle to startAngle plus |
| 3418 | sweepAngle. startAngle and sweepAngle are in degrees. |
| 3419 | startAngle of zero places start point at the right middle edge of oval. |
| 3420 | A positive sweepAngle places Arc end point clockwise from start point; |
| 3421 | a negative sweepAngle places Arc end point counterclockwise from start point. |
| 3422 | sweepAngle may exceed 360 degrees, a full circle. |
| 3423 | If useCenter is true, draw a wedge that includes lines from oval |
| 3424 | center to Arc end points. If useCenter is false, draw Arc between end points. |
| 3425 | |
| 3426 | If Rect oval is empty or sweepAngle is zero, nothing is drawn. |
| 3427 | |
| 3428 | #Param oval Rect bounds of Oval containing Arc to draw. ## |
| 3429 | #Param startAngle Angle in degrees where Arc begins. ## |
| 3430 | #Param sweepAngle Sweep angle in degrees; positive is clockwise. ## |
| 3431 | #Param useCenter If true include the center of the oval. ## |
| 3432 | #Param paint Paint stroke or fill, blend, color, and so on, used to draw. ## |
| 3433 | |
| 3434 | #Example |
| 3435 | void draw(SkCanvas* canvas) {
|
| 3436 | SkPaint paint;
|
| 3437 | paint.setAntiAlias(true);
|
| 3438 | SkRect oval = { 4, 4, 60, 60};
|
| 3439 | for (auto useCenter : { false, true } ) {
|
| 3440 | for (auto style : { SkPaint::kFill_Style, SkPaint::kStroke_Style } ) {
|
| 3441 | paint.setStyle(style);
|
| 3442 | for (auto degrees : { 45, 90, 180, 360} ) {
|
| 3443 | canvas->drawArc(oval, 0, degrees , useCenter, paint);
|
| 3444 | canvas->translate(64, 0);
|
| 3445 | }
|
| 3446 | canvas->translate(-256, 64);
|
| 3447 | }
|
| 3448 | }
|
| 3449 | } |
| 3450 | ## |
| 3451 | |
| 3452 | #Example |
| 3453 | #Height 64 |
| 3454 | void draw(SkCanvas* canvas) {
|
| 3455 | SkPaint paint;
|
| 3456 | paint.setAntiAlias(true);
|
| 3457 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3458 | paint.setStrokeWidth(4);
|
| 3459 | SkRect oval = { 4, 4, 60, 60};
|
| 3460 | float intervals[] = { 5, 5 };
|
| 3461 | paint.setPathEffect(SkDashPathEffect::Make(intervals, 2, 2.5f));
|
| 3462 | for (auto degrees : { 270, 360, 540, 720 } ) {
|
| 3463 | canvas->drawArc(oval, 0, degrees, false, paint);
|
| 3464 | canvas->translate(64, 0);
|
| 3465 | }
|
| 3466 | } |
| 3467 | ## |
| 3468 | |
| 3469 | #ToDo incomplete ## |
| 3470 | |
| 3471 | ## |
| 3472 | |
| 3473 | # ------------------------------------------------------------------------------ |
| 3474 | |
| 3475 | #Method void drawRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, const SkPaint& paint) |
| 3476 | |
| 3477 | Draw Round_Rect bounded by Rect rect, with corner radii (rx, ry) using Clip, Matrix, |
| 3478 | and Paint paint. |
| 3479 | In paint: Paint_Style determines if Round_Rect is stroked or filled; |
| 3480 | if stroked, Paint_Stroke_Width describes the line thickness. |
| 3481 | If rx or ry are less than zero, they are treated as if they are zero. |
| 3482 | If rx plus ry exceeds rect width or rect height, radii are scaled down to fit. |
| 3483 | If rx and ry are zero, Round_Rect is drawn as Rect and if stroked is affected by Paint_Stroke_Join. |
| 3484 | |
| 3485 | #Param rect Rect bounds of Round_Rect to draw. ## |
| 3486 | #Param rx Semiaxis length in x of oval describing rounded corners. ## |
| 3487 | #Param ry Semiaxis length in y of oval describing rounded corners. ## |
| 3488 | #Param paint Stroke, blend, color, and so on, used to draw. ## |
| 3489 | |
| 3490 | #Example |
| 3491 | #Description |
| 3492 | Top row has a zero radius a generates a rectangle. |
| 3493 | Second row radii sum to less than sides. |
| 3494 | Third row radii sum equals sides. |
| 3495 | Fourth row radii sum exceeds sides; radii are scaled to fit. |
| 3496 | ## |
| 3497 | void draw(SkCanvas* canvas) {
|
| 3498 | SkVector radii[] = { {0, 20}, {10, 10}, {10, 20}, {10, 40} };
|
| 3499 | SkPaint paint;
|
| 3500 | paint.setStrokeWidth(15);
|
| 3501 | paint.setStrokeJoin(SkPaint::kRound_Join);
|
| 3502 | paint.setAntiAlias(true);
|
| 3503 | for (auto style : { SkPaint::kStroke_Style, SkPaint::kFill_Style } ) {
|
| 3504 | paint.setStyle(style );
|
| 3505 | for (size_t i = 0; i < SK_ARRAY_COUNT(radii); ++i) {
|
| 3506 | canvas->drawRoundRect({10, 10, 60, 40}, radii[i].fX, radii[i].fY, paint);
|
| 3507 | canvas->translate(0, 60);
|
| 3508 | }
|
| 3509 | canvas->translate(80, -240);
|
| 3510 | }
|
| 3511 | } |
| 3512 | ## |
| 3513 | |
| 3514 | #ToDo incomplete ## |
| 3515 | |
| 3516 | ## |
| 3517 | |
| 3518 | # ------------------------------------------------------------------------------ |
| 3519 | |
| 3520 | #Method void drawPath(const SkPath& path, const SkPaint& paint) |
| 3521 | |
| 3522 | Draw Path path using Clip, Matrix, and Paint paint. |
| 3523 | Path contains an array of Path_Contour, each of which may be open or closed. |
| 3524 | |
| 3525 | In paint: Paint_Style determines if Round_Rect is stroked or filled: |
| 3526 | if filled, Path_Fill_Type determines whether Path_Contour describes inside or outside of fill; |
| 3527 | if stroked, Paint_Stroke_Width describes the line thickness, Paint_Stroke_Cap describes line ends, |
| 3528 | and Paint_Stroke_Join describes how corners are drawn. |
| 3529 | |
| 3530 | #Param path Path to draw. ## |
| 3531 | #Param paint Stroke, blend, color, and so on, used to draw. ## |
| 3532 | |
| 3533 | #Example |
| 3534 | #Description |
| 3535 | Top rows draw stroked path with combinations of joins and caps. The open contour |
| 3536 | is affected by caps; the closed contour is affected by joins. |
| 3537 | Bottom row draws fill the same for open and closed contour. |
| 3538 | First bottom column shows winding fills overlap. |
| 3539 | Second bottom column shows even odd fills exclude overlap. |
| 3540 | Third bottom column shows inverse winding fills area outside both contours. |
| 3541 | ## |
| 3542 | void draw(SkCanvas* canvas) {
|
| 3543 | SkPath path;
|
| 3544 | path.moveTo(20, 20);
|
| 3545 | path.quadTo(60, 20, 60, 60);
|
| 3546 | path.close();
|
| 3547 | path.moveTo(60, 20);
|
| 3548 | path.quadTo(60, 60, 20, 60);
|
| 3549 | SkPaint paint;
|
| 3550 | paint.setStrokeWidth(10);
|
| 3551 | paint.setAntiAlias(true);
|
| 3552 | paint.setStyle(SkPaint::kStroke_Style);
|
| 3553 | for (auto join: { SkPaint::kBevel_Join, SkPaint::kRound_Join, SkPaint::kMiter_Join } ) {
|
| 3554 | paint.setStrokeJoin(join);
|
| 3555 | for (auto cap: { SkPaint::kButt_Cap, SkPaint::kSquare_Cap, SkPaint::kRound_Cap } ) {
|
| 3556 | paint.setStrokeCap(cap);
|
| 3557 | canvas->drawPath(path, paint);
|
| 3558 | canvas->translate(80, 0);
|
| 3559 | }
|
| 3560 | canvas->translate(-240, 60);
|
| 3561 | }
|
| 3562 | paint.setStyle(SkPaint::kFill_Style);
|
| 3563 | for (auto fill : { SkPath::kWinding_FillType,
|
| 3564 | SkPath::kEvenOdd_FillType,
|
| 3565 | SkPath::kInverseWinding_FillType } ) {
|
| 3566 | path.setFillType(fill);
|
| 3567 | canvas->save();
|
| 3568 | canvas->clipRect({0, 10, 80, 70});
|
| 3569 | canvas->drawPath(path, paint);
|
| 3570 | canvas->restore();
|
| 3571 | canvas->translate(80, 0);
|
| 3572 | }
|
| 3573 | } |
| 3574 | ## |
| 3575 | |
| 3576 | #ToDo incomplete ## |
| 3577 | |
| 3578 | ## |
| 3579 | |
| 3580 | # ------------------------------------------------------------------------------ |
| 3581 | #Topic Draw_Image |
| 3582 | |
| 3583 | drawImage, drawImageRect, and drawImageNine can be called with a bare pointer or a smart pointer as a convenience. |
| 3584 | The pairs of calls are otherwise identical. |
| 3585 | |
| 3586 | |
| 3587 | #Method void drawImage(const SkImage* image, SkScalar left, SkScalar top, const SkPaint* paint = NULL) |
| 3588 | |
| 3589 | Draw Image image, with its top-left corner at (left, top), |
| 3590 | using Clip, Matrix, and optional Paint paint. |
| 3591 | |
| 3592 | If paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 3593 | If image is kAlpha_8_SkColorType, apply Shader. |
| 3594 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 3595 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 3596 | SkImage::makeShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 3597 | color when it samples outside of its bounds. |
| 3598 | |
| 3599 | #Param image Uncompressed rectangular map of pixels. ## |
| 3600 | #Param left Left side of image. ## |
| 3601 | #Param top Top side of image. ## |
| 3602 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 3603 | |
| 3604 | #Example |
| 3605 | #Height 64 |
| 3606 | #Image 4 |
| 3607 | void draw(SkCanvas* canvas) {
|
| 3608 | // sk_sp<SkImage> image;
|
| 3609 | SkImage* imagePtr = image.get();
|
| 3610 | canvas->drawImage(imagePtr, 0, 0);
|
| 3611 | SkPaint paint;
|
| 3612 | canvas->drawImage(imagePtr, 80, 0, &paint);
|
| 3613 | paint.setAlpha(0x80);
|
| 3614 | canvas->drawImage(imagePtr, 160, 0, &paint);
|
| 3615 | } |
| 3616 | ## |
| 3617 | |
| 3618 | #ToDo incomplete ## |
| 3619 | |
| 3620 | ## |
| 3621 | |
| 3622 | # ------------------------------------------------------------------------------ |
| 3623 | |
| 3624 | #Method void drawImage(const sk_sp<SkImage>& image, SkScalar left, SkScalar top, |
| 3625 | const SkPaint* paint = NULL) |
| 3626 | |
| 3627 | Draw Image image, with its top-left corner at (left, top), |
| 3628 | using Clip, Matrix, and optional Paint paint. |
| 3629 | |
| 3630 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 3631 | If image is kAlpha_8_SkColorType, apply Shader. |
| 3632 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 3633 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 3634 | SkImage::makeShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 3635 | color when it samples outside of its bounds. |
| 3636 | |
| 3637 | #Param image Uncompressed rectangular map of pixels. ## |
| 3638 | #Param left Left side of image. ## |
| 3639 | #Param top Top side of image. ## |
| 3640 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 3641 | |
| 3642 | #Example |
| 3643 | #Height 64 |
| 3644 | #Image 4 |
| 3645 | void draw(SkCanvas* canvas) {
|
| 3646 | // sk_sp<SkImage> image;
|
| 3647 | canvas->drawImage(image, 0, 0);
|
| 3648 | SkPaint paint;
|
| 3649 | canvas->drawImage(image, 80, 0, &paint);
|
| 3650 | paint.setAlpha(0x80);
|
| 3651 | canvas->drawImage(image, 160, 0, &paint);
|
| 3652 | } |
| 3653 | ## |
| 3654 | |
| 3655 | #ToDo incomplete ## |
| 3656 | |
| 3657 | ## |
| 3658 | |
| 3659 | # ------------------------------------------------------------------------------ |
| 3660 | |
| 3661 | #Enum SrcRectConstraint |
| 3662 | |
| 3663 | #Code |
| 3664 | enum SrcRectConstraint { |
| 3665 | kStrict_SrcRectConstraint, |
| 3666 | kFast_SrcRectConstraint, |
| 3667 | }; |
| 3668 | ## |
| 3669 | |
| 3670 | SrcRectConstraint controls the behavior at the edge of the Rect src, provided to drawImageRect, |
| 3671 | trading off speed for precision. |
| 3672 | |
| 3673 | Image_Filter in Paint may sample multiple pixels in the image. |
| 3674 | Rect src restricts the bounds of pixels that may be read. Image_Filter may slow |
| 3675 | down if it cannot read outside the bounds, when sampling near the edge of Rect src. |
| 3676 | SrcRectConstraint specifies whether an Image_Filter is allowed to read pixels |
| 3677 | outside Rect src. |
| 3678 | |
| 3679 | #Const kStrict_SrcRectConstraint |
| 3680 | Requires Image_Filter to respect Rect src, |
| 3681 | sampling only inside of its bounds, possibly with a performance penalty. |
| 3682 | ## |
| 3683 | |
| 3684 | #Const kFast_SrcRectConstraint |
| 3685 | Permits Image_Filter to sample outside of Rect src |
| 3686 | by half the width of Image_Filter, permitting it to run faster but with |
| 3687 | error at the image edges. |
| 3688 | ## |
| 3689 | |
| 3690 | #Example |
| 3691 | #Height 64 |
| 3692 | #Description |
| 3693 | redBorder contains a black and white checkerboard bordered by red. |
| 3694 | redBorder is drawn scaled by 16 on the left. |
| 3695 | The middle and right bitmaps are filtered checkboards. |
| 3696 | Drawing the checkerboard with kStrict_SrcRectConstraint shows only a blur of black and white. |
| 3697 | Drawing the checkerboard with kFast_SrcRectConstraint allows red to bleed in the corners. |
| 3698 | ## |
| 3699 | void draw(SkCanvas* canvas) {
|
| 3700 | SkBitmap redBorder;
|
| 3701 | redBorder.allocPixels(SkImageInfo::MakeN32Premul(4, 4));
|
| 3702 | SkCanvas checkRed(redBorder);
|
| 3703 | checkRed.clear(SK_ColorRED);
|
| 3704 | uint32_t checkers[][2] = { { SK_ColorBLACK, SK_ColorWHITE },
|
| 3705 | { SK_ColorWHITE, SK_ColorBLACK } };
|
| 3706 | checkRed.writePixels(
|
| 3707 | SkImageInfo::MakeN32Premul(2, 2), (void*) checkers, sizeof(checkers[0]), 1, 1);
|
| 3708 | canvas->scale(16, 16);
|
| 3709 | canvas->drawBitmap(redBorder, 0, 0, nullptr);
|
| 3710 | canvas->resetMatrix();
|
| 3711 | sk_sp<SkImage> image = SkImage::MakeFromBitmap(redBorder);
|
| 3712 | SkPaint lowPaint;
|
| 3713 | lowPaint.setFilterQuality(kLow_SkFilterQuality);
|
| 3714 | for (auto constraint : { SkCanvas::kStrict_SrcRectConstraint,
|
| 3715 | SkCanvas::kFast_SrcRectConstraint } ) {
|
| 3716 | canvas->translate(80, 0);
|
| 3717 | canvas->drawImageRect(image.get(), SkRect::MakeLTRB(1, 1, 3, 3),
|
| 3718 | SkRect::MakeLTRB(16, 16, 48, 48), &lowPaint, constraint);
|
| 3719 | }
|
| 3720 | } |
| 3721 | ## |
| 3722 | |
| 3723 | #ToDo incomplete ## |
| 3724 | |
| 3725 | ## |
| 3726 | |
| 3727 | # ------------------------------------------------------------------------------ |
| 3728 | |
| 3729 | #Method void drawImageRect(const SkImage* image, const SkRect& src, const SkRect& dst, |
| 3730 | const SkPaint* paint, |
| 3731 | SrcRectConstraint constraint = kStrict_SrcRectConstraint) |
| 3732 | |
| 3733 | Draw Rect src of Image image, scaled and translated to fill Rect dst. |
| 3734 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 3735 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 3736 | If image is kAlpha_8_SkColorType, apply Shader. |
| 3737 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 3738 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 3739 | SkImage::makeShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 3740 | color when it samples outside of its bounds. |
| 3741 | constraint set to kStrict_SrcRectConstraint limits Paint Filter_Quality to sample within src; |
| 3742 | set to kFast_SrcRectConstraint allows sampling outside to improve performance. |
| 3743 | |
| 3744 | #Param image Image containing pixels, dimensions, and format. ## |
| 3745 | #Param src Source Rect of image to draw from. ## |
| 3746 | #Param dst Destination Rect of image to draw to. ## |
| 3747 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 3748 | #Param constraint Filter strictly within src or draw faster. ## |
| 3749 | |
| 3750 | #Example |
| 3751 | #Height 64 |
| 3752 | #Description |
| 3753 | The left bitmap draws with Paint default kNone_SkFilterQuality, and stays within |
| 3754 | its bounds; there's no bleeding with kFast_SrcRectConstraint. |
| 3755 | the middle and right bitmaps draw with kLow_SkFilterQuality; with |
| 3756 | kStrict_SrcRectConstraint, the filter remains within the checkerboard, and |
| 3757 | with kFast_SrcRectConstraint red bleeds on the edges. |
| 3758 | ## |
| 3759 | void draw(SkCanvas* canvas) {
|
| 3760 | uint32_t pixels[][4] = {
|
| 3761 | { 0xFFFF0000, 0xFFFF0000, 0xFFFF0000, 0xFFFF0000 },
|
| 3762 | { 0xFFFF0000, 0xFF000000, 0xFFFFFFFF, 0xFFFF0000 },
|
| 3763 | { 0xFFFF0000, 0xFFFFFFFF, 0xFF000000, 0xFFFF0000 },
|
| 3764 | { 0xFFFF0000, 0xFFFF0000, 0xFFFF0000, 0xFFFF0000 } };
|
| 3765 | SkBitmap redBorder;
|
| 3766 | redBorder.installPixels(SkImageInfo::MakeN32Premul(4, 4),
|
| 3767 | (void*) pixels, sizeof(pixels[0]));
|
| 3768 | sk_sp<SkImage> image = SkImage::MakeFromBitmap(redBorder);
|
| 3769 | SkPaint lowPaint;
|
| 3770 | for (auto constraint : {
|
| 3771 | SkCanvas::kFast_SrcRectConstraint,
|
| 3772 | SkCanvas::kStrict_SrcRectConstraint,
|
| 3773 | SkCanvas::kFast_SrcRectConstraint } ) {
|
| 3774 | canvas->drawImageRect(image.get(), SkRect::MakeLTRB(1, 1, 3, 3),
|
| 3775 | SkRect::MakeLTRB(16, 16, 48, 48), &lowPaint, constraint);
|
| 3776 | lowPaint.setFilterQuality(kLow_SkFilterQuality);
|
| 3777 | canvas->translate(80, 0);
|
| 3778 | }
|
| 3779 | }
|
| 3780 | ## |
| 3781 | |
| 3782 | #ToDo incomplete ## |
| 3783 | |
| 3784 | ## |
| 3785 | |
| 3786 | # ------------------------------------------------------------------------------ |
| 3787 | |
| 3788 | #Method void drawImageRect(const SkImage* image, const SkIRect& isrc, const SkRect& dst, |
| 3789 | const SkPaint* paint, SrcRectConstraint constraint = kStrict_SrcRectConstraint) |
| 3790 | |
| 3791 | Draw IRect isrc of Image image, scaled and translated to fill Rect dst. |
| 3792 | Note that isrc is on integer pixel boundaries; dst may include fractional boundaries. |
| 3793 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 3794 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 3795 | If image is kAlpha_8_SkColorType, apply Shader. |
| 3796 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 3797 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 3798 | SkImage::makeShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 3799 | color when it samples outside of its bounds. |
| 3800 | constraint set to kStrict_SrcRectConstraint limits Paint Filter_Quality to sample within src; |
| 3801 | set to kFast_SrcRectConstraint allows sampling outside to improve performance. |
| 3802 | |
| 3803 | #Param image Image containing pixels, dimensions, and format. ## |
| 3804 | #Param isrc Source IRect of image to draw from. ## |
| 3805 | #Param dst Destination Rect of image to draw to. ## |
| 3806 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 3807 | #Param constraint Filter strictly within src or draw faster. ## |
| 3808 | |
| 3809 | #Example |
| 3810 | #Image 4 |
| 3811 | void draw(SkCanvas* canvas) {
|
| 3812 | // sk_sp<SkImage> image;
|
| 3813 | for (auto i : { 1, 2, 4, 8 } ) {
|
| 3814 | canvas->drawImageRect(image.get(), SkIRect::MakeLTRB(0, 0, 100, 100),
|
| 3815 | SkRect::MakeXYWH(i * 20, i * 20, i * 20, i * 20), nullptr);
|
| 3816 | }
|
| 3817 | } |
| 3818 | ## |
| 3819 | |
| 3820 | #ToDo incomplete ## |
| 3821 | |
| 3822 | ## |
| 3823 | |
| 3824 | # ------------------------------------------------------------------------------ |
| 3825 | |
| 3826 | #Method void drawImageRect(const SkImage* image, const SkRect& dst, const SkPaint* paint, |
| 3827 | SrcRectConstraint constraint = kStrict_SrcRectConstraint) |
| 3828 | |
| 3829 | Draw Image image, scaled and translated to fill Rect dst, |
| 3830 | using Clip, Matrix, and optional Paint paint. |
| 3831 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 3832 | If image is kAlpha_8_SkColorType, apply Shader. |
| 3833 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 3834 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 3835 | SkImage::makeShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 3836 | color when it samples outside of its bounds. |
| 3837 | Use constaint to choose kStrict_SrcRectConstraint or kFast_SrcRectConstraint. |
| 3838 | |
| 3839 | #Param image Image containing pixels, dimensions, and format. ## |
| 3840 | #Param dst Destination Rect of image to draw to. ## |
| 3841 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 3842 | #Param constraint Filter strictly within src or draw faster. ## |
| 3843 | |
| 3844 | #Example |
| 3845 | #Image 4 |
| 3846 | void draw(SkCanvas* canvas) {
|
| 3847 | // sk_sp<SkImage> image;
|
| 3848 | for (auto i : { 20, 40, 80, 160 } ) {
|
| 3849 | canvas->drawImageRect(image.get(), SkRect::MakeXYWH(i, i, i, i), nullptr);
|
| 3850 | }
|
| 3851 | } |
| 3852 | ## |
| 3853 | |
| 3854 | #ToDo incomplete ## |
| 3855 | |
| 3856 | ## |
| 3857 | |
| 3858 | # ------------------------------------------------------------------------------ |
| 3859 | |
| 3860 | #Method void drawImageRect(const sk_sp<SkImage>& image, const SkRect& src, const SkRect& dst, |
| 3861 | const SkPaint* paint, |
| 3862 | SrcRectConstraint constraint = kStrict_SrcRectConstraint) |
| 3863 | |
| 3864 | Draw Rect src of Image image, scaled and translated to fill Rect dst. |
| 3865 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 3866 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 3867 | If image is kAlpha_8_SkColorType, apply Shader. |
| 3868 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 3869 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 3870 | SkImage::makeShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 3871 | color when it samples outside of its bounds. |
| 3872 | constraint set to kStrict_SrcRectConstraint limits Paint Filter_Quality to sample within src; |
| 3873 | set to kFast_SrcRectConstraint allows sampling outside to improve performance. |
| 3874 | |
| 3875 | #Param image Image containing pixels, dimensions, and format. ## |
| 3876 | #Param src Source Rect of image to draw from. ## |
| 3877 | #Param dst Destination Rect of image to draw to. ## |
| 3878 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 3879 | #Param constraint Filter strictly within src or draw faster. ## |
| 3880 | |
| 3881 | #Example |
| 3882 | #Height 64 |
| 3883 | #Description |
| 3884 | Canvas scales and translates; transformation from src to dst also scales. |
| 3885 | The two matrices are concatenated to create the final transformation. |
| 3886 | ## |
| 3887 | void draw(SkCanvas* canvas) {
|
| 3888 | uint32_t pixels[][2] = { { SK_ColorBLACK, SK_ColorWHITE },
|
| 3889 | { SK_ColorWHITE, SK_ColorBLACK } };
|
| 3890 | SkBitmap bitmap;
|
| 3891 | bitmap.installPixels(SkImageInfo::MakeN32Premul(2, 2),
|
| 3892 | (void*) pixels, sizeof(pixels[0]));
|
| 3893 | sk_sp<SkImage> image = SkImage::MakeFromBitmap(bitmap);
|
| 3894 | SkPaint paint;
|
| 3895 | canvas->scale(4, 4);
|
| 3896 | for (auto alpha : { 50, 100, 150, 255 } ) {
|
| 3897 | paint.setAlpha(alpha);
|
| 3898 | canvas->drawImageRect(image, SkRect::MakeWH(2, 2), SkRect::MakeWH(8, 8), &paint);
|
| 3899 | canvas->translate(8, 0);
|
| 3900 | }
|
| 3901 | }
|
| 3902 | ## |
| 3903 | |
| 3904 | #ToDo incomplete ## |
| 3905 | |
| 3906 | ## |
| 3907 | |
| 3908 | # ------------------------------------------------------------------------------ |
| 3909 | |
| 3910 | #Method void drawImageRect(const sk_sp<SkImage>& image, const SkIRect& isrc, const SkRect& dst, |
| 3911 | const SkPaint* paint, SrcRectConstraint constraint = kStrict_SrcRectConstraint) |
| 3912 | |
| 3913 | Draw IRect isrc of Image image, scaled and translated to fill Rect dst. |
| 3914 | Note that isrc is on integer pixel boundaries; dst may include fractional boundaries. |
| 3915 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 3916 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 3917 | If image is kAlpha_8_SkColorType, apply Shader. |
| 3918 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 3919 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 3920 | SkShader::MakeBitmapShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 3921 | color when it samples outside of its bounds. |
| 3922 | cons set to kStrict_SrcRectConstraint limits Paint Filter_Quality to sample within src; |
| 3923 | set to kFast_SrcRectConstraint allows sampling outside to improve performance. |
| 3924 | |
| 3925 | #Param image Image containing pixels, dimensions, and format. ## |
| 3926 | #Param isrc Source IRect of image to draw from. ## |
| 3927 | #Param dst Destination Rect of image to draw to. ## |
| 3928 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 3929 | #Param constraint Filter strictly within src or draw faster. ## |
| 3930 | |
| 3931 | #Example |
| 3932 | #Height 64 |
| 3933 | void draw(SkCanvas* canvas) {
|
| 3934 | uint32_t pixels[][2] = { { 0x00000000, 0x55555555},
|
| 3935 | { 0xAAAAAAAA, 0xFFFFFFFF} };
|
| 3936 | SkBitmap bitmap;
|
| 3937 | bitmap.installPixels(SkImageInfo::MakeN32Premul(2, 2),
|
| 3938 | (void*) pixels, sizeof(pixels[0]));
|
| 3939 | sk_sp<SkImage> image = SkImage::MakeFromBitmap(bitmap);
|
| 3940 | SkPaint paint;
|
| 3941 | canvas->scale(4, 4);
|
| 3942 | for (auto color : { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN } ) {
|
| 3943 | paint.setColorFilter(SkColorFilter::MakeModeFilter(color, SkBlendMode::kPlus));
|
| 3944 | canvas->drawImageRect(image, SkIRect::MakeWH(2, 2), SkRect::MakeWH(8, 8), &paint);
|
| 3945 | canvas->translate(8, 0);
|
| 3946 | }
|
| 3947 | } |
| 3948 | ## |
| 3949 | |
| 3950 | #ToDo incomplete ## |
| 3951 | ## |
| 3952 | |
| 3953 | # ------------------------------------------------------------------------------ |
| 3954 | |
| 3955 | #Method void drawImageRect(const sk_sp<SkImage>& image, const SkRect& dst, const SkPaint* paint, |
| 3956 | SrcRectConstraint constraint = kStrict_SrcRectConstraint) |
| 3957 | |
| 3958 | Draw Image image, scaled and translated to fill Rect dst, |
| 3959 | using Clip, Matrix, and optional Paint paint. |
| 3960 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 3961 | If image is kAlpha_8_SkColorType, apply Shader. |
| 3962 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 3963 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 3964 | SkImage::makeShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 3965 | color when it samples outside of its bounds. |
| 3966 | constraint set to kStrict_SrcRectConstraint limits Paint Filter_Quality to sample within src; |
| 3967 | set to kFast_SrcRectConstraint allows sampling outside to improve performance. |
| 3968 | |
| 3969 | #Param image Image containing pixels, dimensions, and format. ## |
| 3970 | #Param dst Destination Rect of image to draw to. ## |
| 3971 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 3972 | #Param constraint Filter strictly within src or draw faster. ## |
| 3973 | |
| 3974 | #Example |
| 3975 | #Height 64 |
| 3976 | void draw(SkCanvas* canvas) {
|
| 3977 | uint32_t pixels[][2] = { { 0x00000000, 0x55550000},
|
| 3978 | { 0xAAAA0000, 0xFFFF0000} };
|
| 3979 | SkBitmap bitmap;
|
| 3980 | bitmap.installPixels(SkImageInfo::MakeN32Premul(2, 2),
|
| 3981 | (void*) pixels, sizeof(pixels[0]));
|
| 3982 | sk_sp<SkImage> image = SkImage::MakeFromBitmap(bitmap);
|
| 3983 | SkPaint paint;
|
| 3984 | canvas->scale(4, 4);
|
| 3985 | for (auto color : { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN } ) {
|
| 3986 | paint.setColorFilter(SkColorFilter::MakeModeFilter(color, SkBlendMode::kPlus));
|
| 3987 | canvas->drawImageRect(image, SkRect::MakeWH(8, 8), &paint);
|
| 3988 | canvas->translate(8, 0);
|
| 3989 | }
|
| 3990 | } |
| 3991 | ## |
| 3992 | |
| 3993 | #ToDo incomplete ## |
| 3994 | |
| 3995 | ## |
| 3996 | |
| 3997 | # ------------------------------------------------------------------------------ |
| 3998 | |
| 3999 | #Method void drawImageNine(const SkImage* image, const SkIRect& center, const SkRect& dst, |
| 4000 | const SkPaint* paint = nullptr) |
| 4001 | |
| 4002 | Draw Image image stretched differentially to fit into Rect dst. |
| 4003 | IRect center divides the image into nine sections: four sides, four corners, and the center. |
| 4004 | corners are unscaled or scaled down proportionately if their sides are larger than dst; |
| 4005 | center and four sides are scaled to fit remaining space, if any. |
| 4006 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 4007 | If paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 4008 | If image is kAlpha_8_SkColorType, apply Shader. |
| 4009 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 4010 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 4011 | SkShader::MakeBitmapShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 4012 | color when it samples outside of its bounds. |
| 4013 | |
| 4014 | #Param image Image containing pixels, dimensions, and format. ## |
| 4015 | #Param center IRect edge of image corners and sides. ## |
| 4016 | #Param dst Destination Rect of image to draw to. ## |
| 4017 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 4018 | |
| 4019 | #Example |
| 4020 | #Height 128 |
| 4021 | #Description |
| 4022 | The leftmost image is smaller than center; only corners are drawn, all scaled to fit. |
| 4023 | The second image equals the size of center; only corners are drawn, unscaled. |
| 4024 | The remaining images are larger than center. All corners draw unscaled. The sides |
| 4025 | and center are scaled if needed to take up the remaining space. |
| 4026 | ## |
| 4027 | void draw(SkCanvas* canvas) {
|
| 4028 | SkIRect center = { 20, 10, 50, 40 };
|
| 4029 | SkBitmap bitmap;
|
| 4030 | bitmap.allocPixels(SkImageInfo::MakeN32Premul(60, 60));
|
| 4031 | SkCanvas bitCanvas(bitmap);
|
| 4032 | SkPaint paint;
|
| 4033 | SkColor gray = 0xFF000000;
|
| 4034 | int left = 0;
|
| 4035 | for (auto right: { center.fLeft, center.fRight, bitmap.width() } ) {
|
| 4036 | int top = 0;
|
| 4037 | for (auto bottom: { center.fTop, center.fBottom, bitmap.height() } ) {
|
| 4038 | paint.setColor(gray);
|
| 4039 | bitCanvas.drawIRect(SkIRect::MakeLTRB(left, top, right, bottom), paint);
|
| 4040 | gray += 0x001f1f1f;
|
| 4041 | top = bottom;
|
| 4042 | }
|
| 4043 | left = right;
|
| 4044 | }
|
| 4045 | sk_sp<SkImage> image = SkImage::MakeFromBitmap(bitmap);
|
| 4046 | SkImage* imagePtr = image.get();
|
| 4047 | for (auto dest: { 20, 30, 40, 60, 90 } ) {
|
| 4048 | canvas->drawImageNine(imagePtr, center, SkRect::MakeWH(dest, dest), nullptr);
|
| 4049 | canvas->translate(dest + 4, 0);
|
| 4050 | }
|
| 4051 | } |
| 4052 | ## |
| 4053 | |
| 4054 | #ToDo incomplete ## |
| 4055 | |
| 4056 | ## |
| 4057 | |
| 4058 | # ------------------------------------------------------------------------------ |
| 4059 | |
| 4060 | #Method void drawImageNine(const sk_sp<SkImage>& image, const SkIRect& center, const SkRect& dst, |
| 4061 | const SkPaint* paint = nullptr) |
| 4062 | |
| 4063 | Draw Image image stretched differentially to fit into Rect dst. |
| 4064 | IRect center divides the image into nine sections: four sides, four corners, and the center. |
| 4065 | corners are unscaled or scaled down proportionately if their sides are larger than dst; |
| 4066 | center and four sides are scaled to fit remaining space, if any. |
| 4067 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 4068 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 4069 | If image is kAlpha_8_SkColorType, apply Shader. |
| 4070 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 4071 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 4072 | SkShader::MakeBitmapShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 4073 | color when it samples outside of its bounds. |
| 4074 | |
| 4075 | #Param image Image containing pixels, dimensions, and format. ## |
| 4076 | #Param center IRect edge of image corners and sides. ## |
| 4077 | #Param dst Destination Rect of image to draw to. ## |
| 4078 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 4079 | |
| 4080 | #Example |
| 4081 | #Height 128 |
| 4082 | #Description |
| 4083 | The two leftmost images has four corners and sides to the left and right of center. |
| 4084 | The leftmost image scales the width of corners proportionately to fit. |
| 4085 | The third and fourth image corners are unscaled; the sides and center are scaled to |
| 4086 | fill the remaining space. |
| 4087 | The rightmost image has four corners scaled vertically to fit, and uses sides above |
| 4088 | and below center to fill the remaining space. |
| 4089 | ## |
| 4090 | void draw(SkCanvas* canvas) {
|
| 4091 | SkIRect center = { 20, 10, 50, 40 };
|
| 4092 | SkBitmap bitmap;
|
| 4093 | bitmap.allocPixels(SkImageInfo::MakeN32Premul(60, 60));
|
| 4094 | SkCanvas bitCanvas(bitmap);
|
| 4095 | SkPaint paint;
|
| 4096 | SkColor gray = 0xFF000000;
|
| 4097 | int left = 0;
|
| 4098 | for (auto right: { center.fLeft, center.fRight, bitmap.width() } ) {
|
| 4099 | int top = 0;
|
| 4100 | for (auto bottom: { center.fTop, center.fBottom, bitmap.height() } ) {
|
| 4101 | paint.setColor(gray);
|
| 4102 | bitCanvas.drawIRect(SkIRect::MakeLTRB(left, top, right, bottom), paint);
|
| 4103 | gray += 0x001f1f1f;
|
| 4104 | top = bottom;
|
| 4105 | }
|
| 4106 | left = right;
|
| 4107 | }
|
| 4108 | sk_sp<SkImage> image = SkImage::MakeFromBitmap(bitmap);
|
| 4109 | for (auto dest: { 20, 30, 40, 60, 90 } ) {
|
| 4110 | canvas->drawImageNine(image, center, SkRect::MakeWH(dest, 110 - dest), nullptr);
|
| 4111 | canvas->translate(dest + 4, 0);
|
| 4112 | }
|
| 4113 | } |
| 4114 | ## |
| 4115 | |
| 4116 | #ToDo incomplete ## |
| 4117 | |
| 4118 | ## |
| 4119 | |
| 4120 | # ------------------------------------------------------------------------------ |
| 4121 | |
| 4122 | #Method void drawBitmap(const SkBitmap& bitmap, SkScalar left, SkScalar top, |
| 4123 | const SkPaint* paint = NULL) |
| 4124 | |
| 4125 | Draw Bitmap bitmap, with its top-left corner at (left, top), |
| 4126 | using Clip, Matrix, and optional Paint paint. |
| 4127 | If paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 4128 | If bitmap is kAlpha_8_SkColorType, apply Shader. |
| 4129 | if paint contains Mask_Filter, generate mask from bitmap bounds. If generated mask extends |
| 4130 | beyond bitmap bounds, replicate bitmap edge colors, just as Shader made from |
| 4131 | SkShader::MakeBitmapShader with SkShader::kClamp_TileMode set replicates the bitmap's edge |
| 4132 | color when it samples outside of its bounds. |
| 4133 | |
| 4134 | #Param bitmap Bitmap containing pixels, dimensions, and format. ## |
| 4135 | #Param left Left side of bitmap. ## |
| 4136 | #Param top Top side of bitmap. ## |
| 4137 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 4138 | |
| 4139 | #Example |
| 4140 | #Height 64 |
| 4141 | void draw(SkCanvas* canvas) {
|
| 4142 | uint8_t pixels[][8] = { { 0x00, 0x00, 0x00, 0xFF, 0xFF, 0x00, 0x00, 0x00},
|
| 4143 | { 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00},
|
| 4144 | { 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00},
|
| 4145 | { 0xFF, 0xFF, 0x00, 0xFF, 0xFF, 0x00, 0xFF, 0xFF},
|
| 4146 | { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
|
| 4147 | { 0x00, 0x00, 0xFF, 0x00, 0x00, 0xFF, 0x00, 0x00},
|
| 4148 | { 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0x00, 0xFF, 0x00},
|
| 4149 | { 0xFF, 0x00, 0xFF, 0x00, 0x00, 0xFF, 0x00, 0xFF} };
|
| 4150 | SkBitmap bitmap;
|
| 4151 | bitmap.installPixels(SkImageInfo::MakeA8(8, 8),
|
| 4152 | (void*) pixels, sizeof(pixels[0]));
|
| 4153 | SkPaint paint;
|
| 4154 | canvas->scale(4, 4);
|
| 4155 | for (auto color : { SK_ColorRED, SK_ColorBLUE, 0xFF007F00} ) {
|
| 4156 | paint.setColor(color);
|
| 4157 | canvas->drawBitmap(bitmap, 0, 0, &paint);
|
| 4158 | canvas->translate(12, 0);
|
| 4159 | }
|
| 4160 | } |
| 4161 | ## |
| 4162 | |
| 4163 | #ToDo incomplete ## |
| 4164 | |
| 4165 | ## |
| 4166 | |
| 4167 | # ------------------------------------------------------------------------------ |
| 4168 | |
| 4169 | #Method void drawBitmapRect(const SkBitmap& bitmap, const SkRect& src, const SkRect& dst, |
| 4170 | const SkPaint* paint, SrcRectConstraint constraint = kStrict_SrcRectConstraint) |
| 4171 | |
| 4172 | Draw Rect src of Bitmap bitmap, scaled and translated to fill Rect dst. |
| 4173 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 4174 | If paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 4175 | If bitmap is kAlpha_8_SkColorType, apply Shader. |
| 4176 | if paint contains Mask_Filter, generate mask from bitmap bounds. If generated mask extends |
| 4177 | beyond bitmap bounds, replicate bitmap edge colors, just as Shader made from |
| 4178 | SkShader::MakeBitmapShader with SkShader::kClamp_TileMode set replicates the bitmap's edge |
| 4179 | color when it samples outside of its bounds. |
| 4180 | constraint set to kStrict_SrcRectConstraint limits Paint Filter_Quality to sample within src; |
| 4181 | set to kFast_SrcRectConstraint allows sampling outside to improve performance. |
| 4182 | |
| 4183 | #Param bitmap Bitmap containing pixels, dimensions, and format. ## |
| 4184 | #Param src Source Rect of image to draw from. ## |
| 4185 | #Param dst Destination Rect of image to draw to. ## |
| 4186 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 4187 | #Param constraint Filter strictly within src or draw faster. ## |
| 4188 | |
| 4189 | #Example |
| 4190 | #Height 64 |
| 4191 | void draw(SkCanvas* canvas) {
|
| 4192 | uint8_t pixels[][8] = { { 0x00, 0x00, 0x00, 0xFF, 0xFF, 0x00, 0x00, 0x00},
|
| 4193 | { 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00},
|
| 4194 | { 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00},
|
| 4195 | { 0xFF, 0xFF, 0x00, 0xFF, 0xFF, 0x00, 0xFF, 0xFF},
|
| 4196 | { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
|
| 4197 | { 0x00, 0x00, 0xFF, 0x00, 0x00, 0xFF, 0x00, 0x00},
|
| 4198 | { 0x00, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0x00},
|
| 4199 | { 0x00, 0x00, 0xFF, 0x00, 0x00, 0xFF, 0x00, 0x00} };
|
| 4200 | SkBitmap bitmap;
|
| 4201 | bitmap.installPixels(SkImageInfo::MakeA8(8, 8),
|
| 4202 | (void*) pixels, sizeof(pixels[0]));
|
| 4203 | SkPaint paint;
|
| 4204 | paint.setMaskFilter(SkBlurMaskFilter::Make(kSolid_SkBlurStyle, 6));
|
| 4205 | for (auto color : { SK_ColorRED, SK_ColorBLUE, 0xFF007F00} ) {
|
| 4206 | paint.setColor(color);
|
| 4207 | canvas->drawBitmapRect(bitmap, SkRect::MakeWH(8, 8), SkRect::MakeWH(32, 32), &paint);
|
| 4208 | canvas->translate(48, 0);
|
| 4209 | }
|
| 4210 | } |
| 4211 | ## |
| 4212 | |
| 4213 | #ToDo incomplete ## |
| 4214 | |
| 4215 | ## |
| 4216 | |
| 4217 | # ------------------------------------------------------------------------------ |
| 4218 | |
| 4219 | #Method void drawBitmapRect(const SkBitmap& bitmap, const SkIRect& isrc, const SkRect& dst, |
| 4220 | const SkPaint* paint, SrcRectConstraint constraint = kStrict_SrcRectConstraint) |
| 4221 | |
| 4222 | Draw IRect isrc of Bitmap bitmap, scaled and translated to fill Rect dst. |
| 4223 | Note that isrc is on integer pixel boundaries; dst may include fractional boundaries. |
| 4224 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 4225 | If paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 4226 | If bitmap is kAlpha_8_SkColorType, apply Shader. |
| 4227 | if paint contains Mask_Filter, generate mask from bitmap bounds. If generated mask extends |
| 4228 | beyond bitmap bounds, replicate bitmap edge colors, just as Shader made from |
| 4229 | SkShader::MakeBitmapShader with SkShader::kClamp_TileMode set replicates the bitmap's edge |
| 4230 | color when it samples outside of its bounds. |
| 4231 | constraint set to kStrict_SrcRectConstraint limits Paint Filter_Quality to sample within src; |
| 4232 | set to kFast_SrcRectConstraint allows sampling outside to improve performance. |
| 4233 | |
| 4234 | #Param bitmap Bitmap containing pixels, dimensions, and format. ## |
| 4235 | #Param isrc Source IRect of image to draw from. ## |
| 4236 | #Param dst Destination Rect of image to draw to. ## |
| 4237 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 4238 | #Param constraint Filter strictly within src or draw faster. ## |
| 4239 | |
| 4240 | #Example |
| 4241 | #Height 64 |
| 4242 | void draw(SkCanvas* canvas) {
|
| 4243 | uint8_t pixels[][8] = { { 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00},
|
| 4244 | { 0x00, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0x00},
|
| 4245 | { 0xFF, 0x00, 0xFF, 0x00, 0xFF, 0x00, 0x00, 0xFF},
|
| 4246 | { 0xFF, 0x00, 0xFF, 0x00, 0xFF, 0x00, 0x00, 0xFF},
|
| 4247 | { 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF},
|
| 4248 | { 0xFF, 0x00, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0xFF},
|
| 4249 | { 0x00, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0x00},
|
| 4250 | { 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00} };
|
| 4251 | SkBitmap bitmap;
|
| 4252 | bitmap.installPixels(SkImageInfo::MakeA8(8, 8),
|
| 4253 | (void*) pixels, sizeof(pixels[0]));
|
| 4254 | SkPaint paint;
|
| 4255 | paint.setFilterQuality(kHigh_SkFilterQuality);
|
| 4256 | for (auto color : { SK_ColorRED, SK_ColorBLUE, 0xFF007F00, 0xFF7f007f} ) {
|
| 4257 | paint.setColor(color);
|
| 4258 | canvas->drawBitmapRect(bitmap, SkIRect::MakeWH(8, 8), SkRect::MakeWH(32, 32), &paint);
|
| 4259 | canvas->translate(48.25f, 0);
|
| 4260 | }
|
| 4261 | } |
| 4262 | ## |
| 4263 | |
| 4264 | #ToDo incomplete ## |
| 4265 | |
| 4266 | ## |
| 4267 | |
| 4268 | # ------------------------------------------------------------------------------ |
| 4269 | |
| 4270 | #Method void drawBitmapRect(const SkBitmap& bitmap, const SkRect& dst, const SkPaint* paint, |
| 4271 | SrcRectConstraint constraint = kStrict_SrcRectConstraint) |
| 4272 | |
| 4273 | Draw Bitmap bitmap, scaled and translated to fill Rect dst. |
| 4274 | Note that isrc is on integer pixel boundaries; dst may include fractional boundaries. |
| 4275 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 4276 | If paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 4277 | If bitmap is kAlpha_8_SkColorType, apply Shader. |
| 4278 | if paint contains Mask_Filter, generate mask from bitmap bounds. If generated mask extends |
| 4279 | beyond bitmap bounds, replicate bitmap edge colors, just as Shader made from |
| 4280 | SkShader::MakeBitmapShader with SkShader::kClamp_TileMode set replicates the bitmap's edge |
| 4281 | color when it samples outside of its bounds. |
| 4282 | constraint set to kStrict_SrcRectConstraint limits Paint Filter_Quality to sample within src; |
| 4283 | set to kFast_SrcRectConstraint allows sampling outside to improve performance. |
| 4284 | |
| 4285 | #Param bitmap Bitmap containing pixels, dimensions, and format. ## |
| 4286 | #Param dst Destination Rect of image to draw to. ## |
| 4287 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 4288 | #Param constraint Filter strictly within src or draw faster. ## |
| 4289 | |
| 4290 | #Example |
| 4291 | #Height 64 |
| 4292 | void draw(SkCanvas* canvas) {
|
| 4293 | uint32_t pixels[][2] = { { 0x00000000, 0x55550000},
|
| 4294 | { 0xAAAA0000, 0xFFFF0000} };
|
| 4295 | SkBitmap bitmap;
|
| 4296 | bitmap.installPixels(SkImageInfo::MakeN32Premul(2, 2),
|
| 4297 | (void*) pixels, sizeof(pixels[0]));
|
| 4298 | SkPaint paint;
|
| 4299 | canvas->scale(4, 4);
|
| 4300 | for (auto color : { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN } ) {
|
| 4301 | paint.setColorFilter(SkColorFilter::MakeModeFilter(color, SkBlendMode::kPlus));
|
| 4302 | canvas->drawBitmapRect(bitmap, SkRect::MakeWH(8, 8), &paint);
|
| 4303 | canvas->translate(8, 0);
|
| 4304 | }
|
| 4305 | } |
| 4306 | ## |
| 4307 | |
| 4308 | #ToDo incomplete ## |
| 4309 | |
| 4310 | ## |
| 4311 | |
| 4312 | # ------------------------------------------------------------------------------ |
| 4313 | |
| 4314 | #Method void drawBitmapNine(const SkBitmap& bitmap, const SkIRect& center, const SkRect& dst, |
| 4315 | const SkPaint* paint = NULL) |
| 4316 | |
| 4317 | Draw Bitmap bitmap stretched differentially to fit into Rect dst. |
| 4318 | IRect center divides the bitmap into nine sections: four sides, four corners, and the center. |
| 4319 | corners are unscaled or scaled down proportionately if their sides are larger than dst; |
| 4320 | center and four sides are scaled to fit remaining space, if any. |
| 4321 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 4322 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 4323 | If bitmap is kAlpha_8_SkColorType, apply Shader. |
| 4324 | if paint contains Mask_Filter, generate mask from bitmap bounds. If generated mask extends |
| 4325 | beyond bitmap bounds, replicate bitmap edge colors, just as Shader made from |
| 4326 | SkShader::MakeBitmapShader with SkShader::kClamp_TileMode set replicates the bitmap's edge |
| 4327 | color when it samples outside of its bounds. |
| 4328 | |
| 4329 | #Param bitmap Bitmap containing pixels, dimensions, and format. ## |
| 4330 | #Param center IRect edge of image corners and sides. ## |
| 4331 | #Param dst Destination Rect of image to draw to. ## |
| 4332 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 4333 | |
| 4334 | #Example |
| 4335 | #Height 128 |
| 4336 | #Description |
| 4337 | The two leftmost bitmap draws has four corners and sides to the left and right of center. |
| 4338 | The leftmost bitmap draw scales the width of corners proportionately to fit. |
| 4339 | The third and fourth draw corners are unscaled; the sides and center are scaled to |
| 4340 | fill the remaining space. |
| 4341 | The rightmost bitmap draw has four corners scaled vertically to fit, and uses sides above |
| 4342 | and below center to fill the remaining space. |
| 4343 | ## |
| 4344 | void draw(SkCanvas* canvas) {
|
| 4345 | SkIRect center = { 20, 10, 50, 40 };
|
| 4346 | SkBitmap bitmap;
|
| 4347 | bitmap.allocPixels(SkImageInfo::MakeN32Premul(60, 60));
|
| 4348 | SkCanvas bitCanvas(bitmap);
|
| 4349 | SkPaint paint;
|
| 4350 | SkColor gray = 0xFF000000;
|
| 4351 | int left = 0;
|
| 4352 | for (auto right: { center.fLeft, center.fRight, bitmap.width() } ) {
|
| 4353 | int top = 0;
|
| 4354 | for (auto bottom: { center.fTop, center.fBottom, bitmap.height() } ) {
|
| 4355 | paint.setColor(gray);
|
| 4356 | bitCanvas.drawIRect(SkIRect::MakeLTRB(left, top, right, bottom), paint);
|
| 4357 | gray += 0x001f1f1f;
|
| 4358 | top = bottom;
|
| 4359 | }
|
| 4360 | left = right;
|
| 4361 | }
|
| 4362 | for (auto dest: { 20, 30, 40, 60, 90 } ) {
|
| 4363 | canvas->drawBitmapNine(bitmap, center, SkRect::MakeWH(dest, 110 - dest), nullptr);
|
| 4364 | canvas->translate(dest + 4, 0);
|
| 4365 | }
|
| 4366 | } |
| 4367 | ## |
| 4368 | |
| 4369 | #ToDo incomplete ## |
| 4370 | |
| 4371 | ## |
| 4372 | |
| 4373 | # ------------------------------------------------------------------------------ |
| 4374 | #Struct Lattice |
| 4375 | |
| 4376 | Lattice divides Bitmap or Image into a rectangular grid. |
| 4377 | Grid entries on even columns and even rows are fixed; these entries are |
| 4378 | always drawn at their original size if the destination is large enough. |
| 4379 | If the destination side is too small to hold the fixed entries, all fixed |
| 4380 | entries are proportionately scaled down to fit. |
| 4381 | The grid entries not on even columns and rows are scaled to fit the |
| 4382 | remaining space, if any. |
| 4383 | |
| 4384 | #Code |
| 4385 | struct Lattice { |
| 4386 | enum Flags {... |
| 4387 | |
| 4388 | const int* fXDivs; |
| 4389 | const int* fYDivs; |
| 4390 | const Flags* fFlags; |
| 4391 | int fXCount; |
| 4392 | int fYCount; |
| 4393 | const SkIRect* fBounds; |
| 4394 | }; |
| 4395 | ## |
| 4396 | |
| 4397 | #Enum Flags |
| 4398 | #Code |
| 4399 | enum Flags : uint8_t { |
| 4400 | kTransparent_Flags = 1 << 0, |
| 4401 | }; |
| 4402 | ## |
| 4403 | |
| 4404 | Optional setting per rectangular grid entry to make it transparent. |
| 4405 | |
| 4406 | #Const kTransparent_Flags 1 |
| 4407 | Set to skip lattice rectangle by making it transparent. |
| 4408 | ## |
| 4409 | ## |
| 4410 | |
| 4411 | #Member const int* fXDivs |
| 4412 | Array of x-coordinates that divide the bitmap vertically. |
| 4413 | Array entries must be unique, increasing, greater than or equal to fBounds left edge, |
| 4414 | and less than fBounds right edge. |
| 4415 | Set the first element to fBounds left to collapse the left column of fixed grid entries. |
| 4416 | ## |
| 4417 | |
| 4418 | #Member const int* fYDivs |
| 4419 | Array of y-coordinates that divide the bitmap horizontally. |
| 4420 | Array entries must be unique, increasing, greater than or equal to fBounds top edge, |
| 4421 | and less than fBounds bottom edge. |
| 4422 | Set the first element to fBounds top to collapse the top row of fixed grid entries. |
| 4423 | ## |
| 4424 | |
| 4425 | #Member const Flags* fFlags |
| 4426 | Optional array of Flags, one per rectangular grid entry: |
| 4427 | array length must be (fXCount + 1) * (fYCount + 1). |
| 4428 | Array entries correspond to the rectangular grid entries, ascending |
| 4429 | left to right and then top to bottom. |
| 4430 | ## |
| 4431 | |
| 4432 | #Member int fXCount |
| 4433 | Number of entries in fXDivs array; one less than the number of horizontal divisions. |
| 4434 | ## |
| 4435 | |
| 4436 | #Member int fYCount |
| 4437 | Number of entries in fYDivs array; one less than the number of vertical divisions. |
| 4438 | ## |
| 4439 | |
| 4440 | #Member const SkIRect* fBounds |
| 4441 | Optional subset IRect source to draw from. |
| 4442 | If nullptr, source bounds is dimensions of Bitmap or Image. |
| 4443 | ## |
| 4444 | |
| 4445 | #Struct Lattice ## |
| 4446 | |
| 4447 | #Method void drawBitmapLattice(const SkBitmap& bitmap, const Lattice& lattice, const SkRect& dst, |
| 4448 | const SkPaint* paint = nullptr) |
| 4449 | |
| 4450 | Draw Bitmap bitmap stretched differentially to fit into Rect dst. |
| 4451 | |
| 4452 | Lattice lattice divides bitmap into a rectangular grid. |
| 4453 | Each intersection of an even-numbered row and column is fixed; like the corners |
| 4454 | of drawBitmapNine, fixed lattice elements never scale larger than their initial size |
| 4455 | and shrink proportionately when all fixed elements exceed the bitmap's dimension. |
| 4456 | All other grid elements scale to fill the available space, if any. |
| 4457 | |
| 4458 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 4459 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 4460 | If bitmap is kAlpha_8_SkColorType, apply Shader. |
| 4461 | if paint contains Mask_Filter, generate mask from bitmap bounds. If generated mask extends |
| 4462 | beyond bitmap bounds, replicate bitmap edge colors, just as Shader made from |
| 4463 | SkShader::MakeBitmapShader with SkShader::kClamp_TileMode set replicates the bitmap's edge |
| 4464 | color when it samples outside of its bounds. |
| 4465 | |
| 4466 | #Param bitmap Bitmap containing pixels, dimensions, and format. ## |
| 4467 | #Param lattice Division of bitmap into fixed and variable rectangles. ## |
| 4468 | #Param dst Destination Rect of image to draw to. ## |
| 4469 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 4470 | |
| 4471 | #Example |
| 4472 | #Height 128 |
| 4473 | #Description |
| 4474 | The two leftmost bitmap draws has four corners and sides to the left and right of center. |
| 4475 | The leftmost bitmap draw scales the width of corners proportionately to fit. |
| 4476 | The third and fourth draw corners are unscaled; the sides are scaled to |
| 4477 | fill the remaining space; the center is transparent. |
| 4478 | The rightmost bitmap draw has four corners scaled vertically to fit, and uses sides above |
| 4479 | and below center to fill the remaining space. |
| 4480 | ## |
| 4481 | void draw(SkCanvas* canvas) {
|
| 4482 | SkIRect center = { 20, 10, 50, 40 };
|
| 4483 | SkBitmap bitmap;
|
| 4484 | bitmap.allocPixels(SkImageInfo::MakeN32Premul(60, 60));
|
| 4485 | SkCanvas bitCanvas(bitmap);
|
| 4486 | SkPaint paint;
|
| 4487 | SkColor gray = 0xFF000000;
|
| 4488 | int left = 0;
|
| 4489 | for (auto right: { center.fLeft, center.fRight, bitmap.width() } ) {
|
| 4490 | int top = 0;
|
| 4491 | for (auto bottom: { center.fTop, center.fBottom, bitmap.height() } ) {
|
| 4492 | paint.setColor(gray);
|
| 4493 | bitCanvas.drawIRect(SkIRect::MakeLTRB(left, top, right, bottom), paint);
|
| 4494 | gray += 0x001f1f1f;
|
| 4495 | top = bottom;
|
| 4496 | }
|
| 4497 | left = right;
|
| 4498 | }
|
| 4499 | const int xDivs[] = { center.fLeft, center.fRight };
|
| 4500 | const int yDivs[] = { center.fTop, center.fBottom };
|
| 4501 | SkCanvas::Lattice::Flags flags[3][3];
|
| 4502 | memset(flags, 0, sizeof(flags));
|
| 4503 | flags[1][1] = SkCanvas::Lattice::kTransparent_Flags;
|
| 4504 | SkCanvas::Lattice lattice = { xDivs, yDivs, flags[0], SK_ARRAY_COUNT(xDivs),
|
| 4505 | SK_ARRAY_COUNT(yDivs), nullptr };
|
| 4506 | for (auto dest: { 20, 30, 40, 60, 90 } ) {
|
| 4507 | canvas->drawBitmapLattice(bitmap, lattice , SkRect::MakeWH(dest, 110 - dest), nullptr);
|
| 4508 | canvas->translate(dest + 4, 0);
|
| 4509 | }
|
| 4510 | } |
| 4511 | ## |
| 4512 | |
| 4513 | #ToDo incomplete ## |
| 4514 | |
| 4515 | ## |
| 4516 | |
| 4517 | # ------------------------------------------------------------------------------ |
| 4518 | |
| 4519 | #Method void drawImageLattice(const SkImage* image, const Lattice& lattice, const SkRect& dst, |
| 4520 | const SkPaint* paint = nullptr) |
| 4521 | |
| 4522 | Draw Image image stretched differentially to fit into Rect dst. |
| 4523 | |
| 4524 | Lattice lattice divides image into a rectangular grid. |
| 4525 | Each intersection of an even-numbered row and column is fixed; like the corners |
| 4526 | of drawImageNine, fixed lattice elements never scale larger than their initial size |
| 4527 | and shrink proportionately when all fixed elements exceed the bitmap's dimension. |
| 4528 | All other grid elements scale to fill the available space, if any. |
| 4529 | |
| 4530 | Additionally transform draw using Clip, Matrix, and optional Paint paint. |
| 4531 | If Paint paint is supplied, apply Color_Filter, Color_Alpha, Image_Filter, Blend_Mode, and Draw_Looper. |
| 4532 | If image is kAlpha_8_SkColorType, apply Shader. |
| 4533 | if paint contains Mask_Filter, generate mask from image bounds. If generated mask extends |
| 4534 | beyond image bounds, replicate image edge colors, just as Shader made from |
| 4535 | SkShader::MakeBitmapShader with SkShader::kClamp_TileMode set replicates the image's edge |
| 4536 | color when it samples outside of its bounds. |
| 4537 | |
| 4538 | #Param image Image containing pixels, dimensions, and format. ## |
| 4539 | #Param lattice Division of bitmap into fixed and variable rectangles. ## |
| 4540 | #Param dst Destination Rect of image to draw to. ## |
| 4541 | #Param paint Paint containing Blend_Mode, Color_Filter, Image_Filter, and so on; or nullptr. ## |
| 4542 | |
| 4543 | #Example |
| 4544 | #Height 128 |
| 4545 | #Description |
| 4546 | The leftmost image is smaller than center; only corners are drawn, all scaled to fit. |
| 4547 | The second image equals the size of center; only corners are drawn, unscaled. |
| 4548 | The remaining images are larger than center. All corners draw unscaled. The sides |
| 4549 | are scaled if needed to take up the remaining space; the center is transparent. |
| 4550 | ## |
| 4551 | void draw(SkCanvas* canvas) {
|
| 4552 | SkIRect center = { 20, 10, 50, 40 };
|
| 4553 | SkBitmap bitmap;
|
| 4554 | bitmap.allocPixels(SkImageInfo::MakeN32Premul(60, 60));
|
| 4555 | SkCanvas bitCanvas(bitmap);
|
| 4556 | SkPaint paint;
|
| 4557 | SkColor gray = 0xFF000000;
|
| 4558 | int left = 0;
|
| 4559 | for (auto right: { center.fLeft, center.fRight, bitmap.width() } ) {
|
| 4560 | int top = 0;
|
| 4561 | for (auto bottom: { center.fTop, center.fBottom, bitmap.height() } ) {
|
| 4562 | paint.setColor(gray);
|
| 4563 | bitCanvas.drawIRect(SkIRect::MakeLTRB(left, top, right, bottom), paint);
|
| 4564 | gray += 0x001f1f1f;
|
| 4565 | top = bottom;
|
| 4566 | }
|
| 4567 | left = right;
|
| 4568 | }
|
| 4569 | const int xDivs[] = { center.fLeft, center.fRight };
|
| 4570 | const int yDivs[] = { center.fTop, center.fBottom };
|
| 4571 | SkCanvas::Lattice::Flags flags[3][3];
|
| 4572 | memset(flags, 0, sizeof(flags));
|
| 4573 | flags[1][1] = SkCanvas::Lattice::kTransparent_Flags;
|
| 4574 | SkCanvas::Lattice lattice = { xDivs, yDivs, flags[0], SK_ARRAY_COUNT(xDivs),
|
| 4575 | SK_ARRAY_COUNT(yDivs), nullptr };
|
| 4576 | sk_sp<SkImage> image = SkImage::MakeFromBitmap(bitmap);
|
| 4577 | SkImage* imagePtr = image.get();
|
| 4578 | for (auto dest: { 20, 30, 40, 60, 90 } ) {
|
| 4579 | canvas->drawImageNine(imagePtr, center, SkRect::MakeWH(dest, dest), nullptr);
|
| 4580 | canvas->translate(dest + 4, 0);
|
| 4581 | }
|
| 4582 | } |
| 4583 | ## |
| 4584 | |
| 4585 | #ToDo incomplete ## |
| 4586 | |
| 4587 | ## |
| 4588 | |
| 4589 | #Topic Draw_Image ## |
| 4590 | |
| 4591 | # ------------------------------------------------------------------------------ |
| 4592 | |
| 4593 | #Method void drawText(const void* text, size_t byteLength, SkScalar x, SkScalar y, |
| 4594 | const SkPaint& paint) |
| 4595 | |
| 4596 | Draw text, with origin at (x, y), using Clip, Matrix, and Paint paint. |
| 4597 | text's meaning depends on Paint_Text_Encoding; by default, text encoding is UTF-8. |
| 4598 | x and y meaning depends on Paint_Text_Align and Paint_Vertical_Text; by default text |
| 4599 | draws left to right, positioning the first glyph's left side bearing at x and its |
| 4600 | baseline at y. Text size is affected by Matrix and Paint_Text_Size. |
| 4601 | |
| 4602 | All elements of paint: Path_Effect, Rasterizer, Mask_Filter, Shader, Color_Filter, |
| 4603 | Image_Filter, and Draw_Looper; apply to text. By default, drawText draws filled 12 point black |
| 4604 | glyphs. |
| 4605 | |
| 4606 | #Param text Character code points or glyphs drawn. ## |
| 4607 | #Param byteLength Byte length of text array. ## |
| 4608 | #Param x Start of text on x-axis. ## |
| 4609 | #Param y Start of text on y-axis. ## |
| 4610 | #Param paint Text size, blend, color, and so on, used to draw. ## |
| 4611 | |
| 4612 | #Example |
| 4613 | #Height 200 |
| 4614 | #Description |
| 4615 | The same text is drawn varying Paint_Text_Size and varying |
| 4616 | Matrix. |
| 4617 | ## |
| 4618 | void draw(SkCanvas* canvas) {
|
| 4619 | SkPaint paint;
|
| 4620 | paint.setAntiAlias(true);
|
| 4621 | float textSizes[] = { 12, 18, 24, 36 };
|
| 4622 | for (auto size: textSizes ) {
|
| 4623 | paint.setTextSize(size);
|
| 4624 | canvas->drawText("Aa", 2, 10, 20, paint);
|
| 4625 | canvas->translate(0, size * 2);
|
| 4626 | }
|
| 4627 | paint.reset();
|
| 4628 | paint.setAntiAlias(true);
|
| 4629 | float yPos = 20;
|
| 4630 | for (auto size: textSizes ) {
|
| 4631 | float scale = size / 12.f;
|
| 4632 | canvas->resetMatrix();
|
| 4633 | canvas->translate(100, 0);
|
| 4634 | canvas->scale(scale, scale);
|
| 4635 | canvas->drawText("Aa", 2, 10 / scale, yPos / scale, paint);
|
| 4636 | yPos += size * 2;
|
| 4637 | }
|
| 4638 | }
|
| 4639 | ## |
| 4640 | |
| 4641 | #ToDo incomplete ## |
| 4642 | |
| 4643 | ## |
| 4644 | |
| 4645 | #Method void drawString(const char* string, SkScalar x, SkScalar y, const SkPaint& paint) |
| 4646 | |
| 4647 | Draw null terminated string, with origin at (x, y), using Clip, Matrix, and Paint paint. |
| 4648 | string's meaning depends on Paint_Text_Encoding; by default, string encoding is UTF-8. |
| 4649 | Other values of Paint_Text_Encoding are unlikely to produce the desired results, since |
| 4650 | zero bytes may be embedded in the string. |
| 4651 | x and y meaning depends on Paint_Text_Align and Paint_Vertical_Text; by default string |
| 4652 | draws left to right, positioning the first glyph's left side bearing at x and its |
| 4653 | baseline at y. Text size is affected by Matrix and Paint_Text_Size. |
| 4654 | |
| 4655 | All elements of paint: Path_Effect, Rasterizer, Mask_Filter, Shader, Color_Filter, |
| 4656 | Image_Filter, and Draw_Looper; apply to string. By default, drawString draws filled 12 point black |
| 4657 | glyphs. |
| 4658 | |
| 4659 | #Param string Character code points or glyphs drawn, ending with a char value of zero. ## |
| 4660 | #Param x Start of string on x-axis. ## |
| 4661 | #Param y Start of string on y-axis. ## |
| 4662 | #Param paint Text size, blend, color, and so on, used to draw. ## |
| 4663 | |
| 4664 | #Example |
| 4665 | SkPaint paint; |
| 4666 | canvas->drawString("a small hello", 20, 20, paint); |
| 4667 | ## |
| 4668 | |
| 4669 | #SeeAlso drawText |
| 4670 | |
| 4671 | ## |
| 4672 | |
| 4673 | #Method void drawString(const SkString& string, SkScalar x, SkScalar y, const SkPaint& paint) |
| 4674 | |
| 4675 | Draw null terminated string, with origin at (x, y), using Clip, Matrix, and Paint paint. |
| 4676 | string's meaning depends on Paint_Text_Encoding; by default, string encoding is UTF-8. |
| 4677 | Other values of Paint_Text_Encoding are unlikely to produce the desired results, since |
| 4678 | zero bytes may be embedded in the string. |
| 4679 | x and y meaning depends on Paint_Text_Align and Paint_Vertical_Text; by default string |
| 4680 | draws left to right, positioning the first glyph's left side bearing at x and its |
| 4681 | baseline at y. Text size is affected by Matrix and Paint_Text_Size. |
| 4682 | |
| 4683 | All elements of paint: Path_Effect, Rasterizer, Mask_Filter, Shader, Color_Filter, |
| 4684 | Image_Filter, and Draw_Looper; apply to string. By default, drawString draws filled 12 point black |
| 4685 | glyphs. |
| 4686 | |
| 4687 | #Param string Character code points or glyphs drawn, ending with a char value of zero. ## |
| 4688 | #Param x Start of string on x-axis. ## |
| 4689 | #Param y Start of string on y-axis. ## |
| 4690 | #Param paint Text size, blend, color, and so on, used to draw. ## |
| 4691 | |
| 4692 | #Example |
| 4693 | SkPaint paint; |
| 4694 | SkString string("a small hello"); |
| 4695 | canvas->drawString(string, 20, 20, paint); |
| 4696 | ## |
| 4697 | |
| 4698 | #SeeAlso drawText |
| 4699 | |
| 4700 | ## |
| 4701 | |
| 4702 | # ------------------------------------------------------------------------------ |
| 4703 | |
| 4704 | #Method void drawPosText(const void* text, size_t byteLength, const SkPoint pos[], |
| 4705 | const SkPaint& paint) |
| 4706 | |
| 4707 | Draw each glyph in text with the origin in pos array, using Clip, Matrix, and Paint paint. |
| 4708 | The number of entries in pos array must match the number of glyphs described by byteLength of text. |
| 4709 | text's meaning depends on Paint_Text_Encoding; by default, text encoding is UTF-8. |
| 4710 | pos elements' meaning depends on Paint_Text_Align and Paint_Vertical_Text; by default each |
| 4711 | glyph's left side bearing is positioned at x and its |
| 4712 | baseline is positioned at y. Text size is affected by Matrix and Paint_Text_Size. |
| 4713 | |
| 4714 | All elements of paint: Path_Effect, Rasterizer, Mask_Filter, Shader, Color_Filter, |
| 4715 | Image_Filter, and Draw_Looper; apply to text. By default, drawPosText draws filled 12 point black |
| 4716 | glyphs. |
| 4717 | |
| 4718 | Layout engines such as Harfbuzz typically use drawPosText to position each glyph |
| 4719 | rather than using the font's advance widths. |
| 4720 | |
| 4721 | #Param text Character code points or glyphs drawn. ## |
| 4722 | #Param byteLength Byte length of text array. ## |
| 4723 | #Param pos Array of glyph origins. ## |
| 4724 | #Param paint Text size, blend, color, and so on, used to draw. ## |
| 4725 | |
| 4726 | #Example |
| 4727 | #Height 120 |
| 4728 | void draw(SkCanvas* canvas) {
|
| 4729 | const char hello[] = "HeLLo!";
|
| 4730 | const SkPoint pos[] = { {40, 100}, {82, 95}, {115, 110}, {130, 95}, {145, 85},
|
| 4731 | {172, 100} };
|
| 4732 | SkPaint paint;
|
| 4733 | paint.setTextSize(60);
|
| 4734 | canvas->drawPosText(hello, strlen(hello), pos, paint);
|
| 4735 | } |
| 4736 | ## |
| 4737 | |
| 4738 | #ToDo incomplete ## |
| 4739 | |
| 4740 | ## |
| 4741 | |
| 4742 | # ------------------------------------------------------------------------------ |
| 4743 | |
| 4744 | #Method void drawPosTextH(const void* text, size_t byteLength, const SkScalar xpos[], SkScalar constY, |
| 4745 | const SkPaint& paint) |
| 4746 | |
| 4747 | Draw each glyph in text with its (x, y) origin composed from xpos array and constY, using Clip, Matrix, and Paint paint. |
| 4748 | The number of entries in xpos array must match the number of glyphs described by byteLength of text. |
| 4749 | text's meaning depends on Paint_Text_Encoding; by default, text encoding is UTF-8. |
| 4750 | pos elements' meaning depends on Paint_Text_Align and Paint_Vertical_Text; by default each |
| 4751 | glyph's left side bearing is positioned at an xpos element and its |
| 4752 | baseline is positioned at constY. Text size is affected by Matrix and Paint_Text_Size. |
| 4753 | |
| 4754 | All elements of paint: Path_Effect, Rasterizer, Mask_Filter, Shader, Color_Filter, |
| 4755 | Image_Filter, and Draw_Looper; apply to text. By default, drawPosTextH draws filled 12 point black |
| 4756 | glyphs. |
| 4757 | |
| 4758 | Layout engines such as Harfbuzz typically use drawPosTextH to position each glyph |
| 4759 | rather than using the font's advance widths if all glyphs share the same baseline. |
| 4760 | |
| 4761 | #Param text Character code points or glyphs drawn. ## |
| 4762 | #Param byteLength Byte length of text array. ## |
| 4763 | #Param xpos Array of x positions, used to position each glyph. ## |
| 4764 | #Param constY Shared y coordinate for all of x positions. ## |
| 4765 | #Param paint Text size, blend, color, and so on, used to draw. ## |
| 4766 | |
| 4767 | #Example |
| 4768 | #Height 40 |
| 4769 | void draw(SkCanvas* canvas) {
|
| 4770 | SkScalar xpos[] = { 20, 40, 80, 160 };
|
| 4771 | SkPaint paint;
|
| 4772 | canvas->drawPosTextH("XXXX", 4, xpos, 20, paint);
|
| 4773 | }
|
| 4774 | ## |
| 4775 | |
| 4776 | #ToDo incomplete ## |
| 4777 | |
| 4778 | ## |
| 4779 | |
| 4780 | # ------------------------------------------------------------------------------ |
| 4781 | |
| 4782 | #Method void drawTextOnPathHV(const void* text, size_t byteLength, const SkPath& path, SkScalar hOffset, |
| 4783 | SkScalar vOffset, const SkPaint& paint) |
| 4784 | |
| 4785 | Draw text on Path path, using Clip, Matrix, and Paint paint. |
| 4786 | Origin of text is at distance hOffset along the path, offset by a perpendicular vector of |
| 4787 | length vOffset. If the path section corresponding the glyph advance is curved, the glyph |
| 4788 | is drawn curved to match; control points in the glyph are mapped to projected points parallel |
| 4789 | to the path. If the text's advance is larger than the path length, the excess text is clipped. |
| 4790 | |
| 4791 | text's meaning depends on Paint_Text_Encoding; by default, text encoding is UTF-8. |
| 4792 | Origin meaning depends on Paint_Text_Align and Paint_Vertical_Text; by default text |
| 4793 | positions the first glyph's left side bearing at origin x and its |
| 4794 | baseline at origin y. Text size is affected by Matrix and Paint_Text_Size. |
| 4795 | |
| 4796 | All elements of paint: Path_Effect, Rasterizer, Mask_Filter, Shader, Color_Filter, |
| 4797 | Image_Filter, and Draw_Looper; apply to text. By default, drawTextOnPathHV draws filled 12 point black |
| 4798 | glyphs. |
| 4799 | |
| 4800 | #Param text Character code points or glyphs drawn. ## |
| 4801 | #Param byteLength Byte length of text array. ## |
| 4802 | #Param path Path providing text baseline. ## |
| 4803 | #Param hOffset Distance along path to offset origin. ## |
| 4804 | #Param vOffset Offset of text above (if negative) or below (if positive) the path. ## |
| 4805 | #Param paint Text size, blend, color, and so on, used to draw. ## |
| 4806 | |
| 4807 | #Example |
| 4808 | void draw(SkCanvas* canvas) {
|
| 4809 | const char aero[] = "correo a" "\xC3" "\xA9" "reo";
|
| 4810 | const size_t len = sizeof(aero) - 1;
|
| 4811 | SkPath path;
|
| 4812 | path.addOval({43-26, 43-26, 43+26, 43+26}, SkPath::kCW_Direction, 3);
|
| 4813 | SkPaint paint;
|
| 4814 | paint.setTextSize(24);
|
| 4815 | for (auto offset : { 0, 10, 20 } ) {
|
| 4816 | canvas->drawTextOnPathHV(aero, len, path, 0, -offset, paint);
|
| 4817 | canvas->translate(70 + offset, 70 + offset);
|
| 4818 | }
|
| 4819 | }
|
| 4820 | ## |
| 4821 | |
| 4822 | #ToDo incomplete ## |
| 4823 | |
| 4824 | ## |
| 4825 | |
| 4826 | # ------------------------------------------------------------------------------ |
| 4827 | |
| 4828 | #Method void drawTextOnPath(const void* text, size_t byteLength, const SkPath& path, |
| 4829 | const SkMatrix* matrix, const SkPaint& paint) |
| 4830 | |
| 4831 | Draw text on Path path, using Clip, Matrix, and Paint paint. |
| 4832 | Origin of text is at beginning of path offset by matrix, if provided, before it is mapped to path. |
| 4833 | If the path section corresponding the glyph advance is curved, the glyph |
| 4834 | is drawn curved to match; control points in the glyph are mapped to projected points parallel |
| 4835 | to the path. If the text's advance is larger than the path length, the excess text is clipped. |
| 4836 | |
| 4837 | text's meaning depends on Paint_Text_Encoding; by default, text encoding is UTF-8. |
| 4838 | Origin meaning depends on Paint_Text_Align and Paint_Vertical_Text; by default text |
| 4839 | positions the first glyph's left side bearing at origin x and its |
| 4840 | baseline at origin y. Text size is affected by Matrix and Paint_Text_Size. |
| 4841 | |
| 4842 | All elements of paint: Path_Effect, Rasterizer, Mask_Filter, Shader, Color_Filter, |
| 4843 | Image_Filter, and Draw_Looper; apply to text. By default, drawTextOnPath draws filled 12 point black |
| 4844 | glyphs. |
| 4845 | |
| 4846 | #Param text Character code points or glyphs drawn. ## |
| 4847 | #Param byteLength Byte length of text array. ## |
| 4848 | #Param path Path providing text baseline. ## |
| 4849 | #Param matrix Optional transform of glyphs before mapping to path; or nullptr. ## |
| 4850 | #Param paint Text size, blend, color, and so on, used to draw. ## |
| 4851 | |
| 4852 | #Example |
| 4853 | void draw(SkCanvas* canvas) {
|
| 4854 | const char roller[] = "rollercoaster";
|
| 4855 | const size_t len = sizeof(roller) - 1;
|
| 4856 | SkPath path;
|
| 4857 | path.cubicTo(40, -80, 120, 80, 160, -40);
|
| 4858 | SkPaint paint;
|
| 4859 | paint.setTextSize(32);
|
| 4860 | paint.setStyle(SkPaint::kStroke_Style);
|
| 4861 | SkMatrix matrix;
|
| 4862 | matrix.setIdentity();
|
| 4863 | for (int i = 0; i < 3; ++i) {
|
| 4864 | canvas->translate(25, 60);
|
| 4865 | canvas->drawPath(path, paint);
|
| 4866 | canvas->drawTextOnPath(roller, len, path, &matrix, paint);
|
| 4867 | matrix.preTranslate(0, 10);
|
| 4868 | }
|
| 4869 | }
|
| 4870 | ## |
| 4871 | |
| 4872 | #ToDo incomplete ## |
| 4873 | |
| 4874 | ## |
| 4875 | |
| 4876 | # ------------------------------------------------------------------------------ |
| 4877 | |
| 4878 | #Method void drawTextRSXform(const void* text, size_t byteLength, const SkRSXform xform[], |
| 4879 | const SkRect* cullRect, const SkPaint& paint) |
| 4880 | |
| 4881 | Draw text, transforming each glyph by the corresponding SkRSXform, |
| 4882 | using Clip, Matrix, and Paint paint. |
| 4883 | RSXform array specifies a separate square scale, rotation, and translation for |
| 4884 | each glyph. |
| 4885 | Optional Rect cullRect is a conservative bounds of text, |
| 4886 | taking into account RSXform and paint. If cullrect is outside of Clip, canvas can |
| 4887 | skip drawing. |
| 4888 | |
| 4889 | All elements of paint: Path_Effect, Rasterizer, Mask_Filter, Shader, Color_Filter, |
| 4890 | Image_Filter, and Draw_Looper; apply to text. By default, drawTextRSXform draws filled 12 point black |
| 4891 | glyphs. |
| 4892 | |
| 4893 | #Param text Character code points or glyphs drawn. ## |
| 4894 | #Param byteLength Byte length of text array. ## |
| 4895 | #Param xform RSXform rotates, scales, and translates each glyph individually. ## |
| 4896 | #Param cullRect Rect bounds of text for efficient clipping; or nullptr. ## |
| 4897 | #Param paint Text size, blend, color, and so on, used to draw. ## |
| 4898 | |
| 4899 | #Example |
| 4900 | void draw(SkCanvas* canvas) {
|
| 4901 | const int iterations = 26;
|
| 4902 | SkRSXform transforms[iterations];
|
| 4903 | char alphabet[iterations];
|
| 4904 | SkScalar angle = 0;
|
| 4905 | SkScalar scale = 1;
|
| 4906 | for (size_t i = 0; i < SK_ARRAY_COUNT(transforms); ++i) {
|
| 4907 | const SkScalar s = SkScalarSin(angle) * scale;
|
| 4908 | const SkScalar c = SkScalarCos(angle) * scale;
|
| 4909 | transforms[i] = SkRSXform::Make(-c, -s, -s * 16, c * 16);
|
| 4910 | angle += .45;
|
| 4911 | scale += .2;
|
| 4912 | alphabet[i] = 'A' + i;
|
| 4913 | }
|
| 4914 | SkPaint paint;
|
| 4915 | paint.setTextAlign(SkPaint::kCenter_Align);
|
| 4916 | canvas->translate(110, 138);
|
| 4917 | canvas->drawTextRSXform(alphabet, sizeof(alphabet), transforms, nullptr, paint);
|
| 4918 | } |
| 4919 | ## |
| 4920 | |
| 4921 | #ToDo incomplete ## |
| 4922 | |
| 4923 | ## |
| 4924 | |
| 4925 | # ------------------------------------------------------------------------------ |
| 4926 | |
| 4927 | #Method void drawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y, const SkPaint& paint) |
| 4928 | |
| 4929 | Draw Text_Blob blob at (x, y), using Clip, Matrix, and Paint paint. |
| 4930 | blob contains glyphs, their positions, and paint attributes specific to text: |
| 4931 | Typeface, Paint_Text_Size, Paint_Text_Scale_X, Paint_Text_Skew_X, Paint_Text_Align, |
| 4932 | Paint_Hinting, Anti-alias, Paint_Fake_Bold, Font_Embedded_Bitmaps, Full_Hinting_Spacing, |
| 4933 | LCD_Text, Linear_Text, Subpixel_Text, and Paint_Vertical_Text. |
| 4934 | |
| 4935 | Elements of paint: Path_Effect, Rasterizer, Mask_Filter, Shader, Color_Filter, |
| 4936 | Image_Filter, and Draw_Looper; apply to blob. |
| 4937 | |
| 4938 | #Param blob Glyphs, positions, and their paints' text size, typeface, and so on. ## |
| 4939 | #Param x Horizontal offset applied to blob. ## |
| 4940 | #Param y Vertical offset applied to blob. ## |
| 4941 | #Param paint Blend, color, stroking, and so on, used to draw. ## |
| 4942 | |
| 4943 | #Example |
| 4944 | #Height 120 |
| 4945 | void draw(SkCanvas* canvas) {
|
| 4946 | SkTextBlobBuilder textBlobBuilder;
|
| 4947 | const char bunny[] = "/(^x^)\\";
|
| 4948 | const int len = sizeof(bunny) - 1;
|
| 4949 | uint16_t glyphs[len];
|
| 4950 | SkPaint paint;
|
| 4951 | paint.textToGlyphs(bunny, len, glyphs);
|
| 4952 | int runs[] = { 3, 1, 3 };
|
| 4953 | SkPoint textPos = { 20, 100 };
|
| 4954 | int glyphIndex = 0;
|
| 4955 | for (auto runLen : runs) {
|
| 4956 | paint.setTextSize(1 == runLen ? 20 : 50);
|
| 4957 | const SkTextBlobBuilder::RunBuffer& run =
|
| 4958 | textBlobBuilder.allocRun(paint, runLen, textPos.fX, textPos.fY);
|
| 4959 | memcpy(run.glyphs, &glyphs[glyphIndex], sizeof(glyphs[0]) * runLen);
|
| 4960 | textPos.fX += paint.measureText(&bunny[glyphIndex], runLen, nullptr);
|
| 4961 | glyphIndex += runLen;
|
| 4962 | }
|
| 4963 | sk_sp<const SkTextBlob> blob = textBlobBuilder.make();
|
| 4964 | paint.reset();
|
| 4965 | canvas->drawTextBlob(blob.get(), 0, 0, paint);
|
| 4966 | } |
| 4967 | ## |
| 4968 | |
| 4969 | #ToDo incomplete ## |
| 4970 | |
| 4971 | ## |
| 4972 | |
| 4973 | # ------------------------------------------------------------------------------ |
| 4974 | |
| 4975 | #Method void drawTextBlob(const sk_sp<SkTextBlob>& blob, SkScalar x, SkScalar y, const SkPaint& paint) |
| 4976 | |
| 4977 | Draw Text_Blob blob at (x, y), using Clip, Matrix, and Paint paint. |
| 4978 | blob contains glyphs, their positions, and paint attributes specific to text: |
| 4979 | Typeface, Paint_Text_Size, Paint_Text_Scale_X, Paint_Text_Skew_X, Paint_Text_Align, |
| 4980 | Paint_Hinting, Anti-alias, Paint_Fake_Bold, Font_Embedded_Bitmaps, Full_Hinting_Spacing, |
| 4981 | LCD_Text, Linear_Text, Subpixel_Text, and Paint_Vertical_Text. |
| 4982 | |
| 4983 | Elements of paint: Path_Effect, Rasterizer, Mask_Filter, Shader, Color_Filter, |
| 4984 | Image_Filter, and Draw_Looper; apply to blob. |
| 4985 | |
| 4986 | #Param blob Glyphs, positions, and their paints' text size, typeface, and so on. ## |
| 4987 | #Param x Horizontal offset applied to blob. ## |
| 4988 | #Param y Vertical offset applied to blob. ## |
| 4989 | #Param paint Blend, color, stroking, and so on, used to draw. ## |
| 4990 | |
| 4991 | #Example |
| 4992 | #Height 120 |
| 4993 | #Description |
| 4994 | Paint attributes unrelated to text, like color, have no effect on paint in allocated Text_Blob. |
| 4995 | Paint attributes related to text, like text size, have no effect on paint passed to drawTextBlob. |
| 4996 | ## |
| 4997 | void draw(SkCanvas* canvas) {
|
| 4998 | SkTextBlobBuilder textBlobBuilder;
|
| 4999 | SkPaint paint;
|
| 5000 | paint.setTextSize(50);
|
| 5001 | paint.setColor(SK_ColorRED);
|
| 5002 | const SkTextBlobBuilder::RunBuffer& run =
|
| 5003 | textBlobBuilder.allocRun(paint, 1, 20, 100);
|
| 5004 | run.glyphs[0] = 20;
|
| 5005 | sk_sp<const SkTextBlob> blob = textBlobBuilder.make();
|
| 5006 | paint.setTextSize(10);
|
| 5007 | paint.setColor(SK_ColorBLUE);
|
| 5008 | canvas->drawTextBlob(blob.get(), 0, 0, paint);
|
| 5009 | }
|
| 5010 | ## |
| 5011 | |
| 5012 | #ToDo incomplete ## |
| 5013 | |
| 5014 | ## |
| 5015 | |
| 5016 | # ------------------------------------------------------------------------------ |
| 5017 | |
| 5018 | #Method void drawPicture(const SkPicture* picture) |
| 5019 | |
| 5020 | Draw Picture picture, using Clip and Matrix. |
| 5021 | Clip and Matrix are unchanged by picture contents, as if |
| 5022 | save() was called before and restore() was called after drawPicture. |
| 5023 | |
| 5024 | Picture records a series of draw commands for later playback. |
| 5025 | |
| 5026 | #Param picture Recorded drawing commands to play. ## |
| 5027 | |
| 5028 | #Example |
| 5029 | void draw(SkCanvas* canvas) {
|
| 5030 | SkPictureRecorder recorder;
|
| 5031 | SkCanvas* recordingCanvas = recorder.beginRecording(50, 50);
|
| 5032 | for (auto color : { SK_ColorRED, SK_ColorBLUE, 0xff007f00 } ) {
|
| 5033 | SkPaint paint;
|
| 5034 | paint.setColor(color);
|
| 5035 | recordingCanvas->drawRect({10, 10, 30, 40}, paint);
|
| 5036 | recordingCanvas->translate(10, 10);
|
| 5037 | recordingCanvas->scale(1.2f, 1.4f);
|
| 5038 | }
|
| 5039 | sk_sp<SkPicture> playback = recorder.finishRecordingAsPicture();
|
| 5040 | const SkPicture* playbackPtr = playback.get();
|
| 5041 | canvas->drawPicture(playback);
|
| 5042 | canvas->scale(2, 2);
|
| 5043 | canvas->translate(50, 0);
|
| 5044 | canvas->drawPicture(playback);
|
| 5045 | } |
| 5046 | ## |
| 5047 | |
| 5048 | #ToDo incomplete ## |
| 5049 | |
| 5050 | ## |
| 5051 | |
| 5052 | # ------------------------------------------------------------------------------ |
| 5053 | |
| 5054 | #Method void drawPicture(const sk_sp<SkPicture>& picture) |
| 5055 | |
| 5056 | Draw Picture picture, using Clip and Matrix. |
| 5057 | Clip and Matrix are unchanged by picture contents, as if |
| 5058 | save() was called before and restore() was called after drawPicture. |
| 5059 | |
| 5060 | Picture records a series of draw commands for later playback. |
| 5061 | |
| 5062 | #Param picture Recorded drawing commands to play. ## |
| 5063 | |
| 5064 | #Example |
| 5065 | void draw(SkCanvas* canvas) {
|
| 5066 | SkPictureRecorder recorder;
|
| 5067 | SkCanvas* recordingCanvas = recorder.beginRecording(50, 50);
|
| 5068 | for (auto color : { SK_ColorRED, SK_ColorBLUE, 0xff007f00 } ) {
|
| 5069 | SkPaint paint;
|
| 5070 | paint.setColor(color);
|
| 5071 | recordingCanvas->drawRect({10, 10, 30, 40}, paint);
|
| 5072 | recordingCanvas->translate(10, 10);
|
| 5073 | recordingCanvas->scale(1.2f, 1.4f);
|
| 5074 | }
|
| 5075 | sk_sp<SkPicture> playback = recorder.finishRecordingAsPicture();
|
| 5076 | canvas->drawPicture(playback);
|
| 5077 | canvas->scale(2, 2);
|
| 5078 | canvas->translate(50, 0);
|
| 5079 | canvas->drawPicture(playback);
|
| 5080 | } |
| 5081 | ## |
| 5082 | |
| 5083 | #ToDo incomplete ## |
| 5084 | |
| 5085 | ## |
| 5086 | |
| 5087 | # ------------------------------------------------------------------------------ |
| 5088 | |
| 5089 | #Method void drawPicture(const SkPicture* picture, const SkMatrix* matrix, const SkPaint* paint) |
| 5090 | |
| 5091 | Draw Picture picture, using Clip and Matrix; |
| 5092 | transforming picture with Matrix matrix, if provided; |
| 5093 | and use Paint paint Color_Alpha, Color_Filter, Image_Filter, and Blend_Mode, if provided. |
| 5094 | |
| 5095 | matrix transformation is equivalent to: save(), concat(), drawPicture, restore(). |
| 5096 | paint use is equivalent to: saveLayer, drawPicture, restore(). |
| 5097 | |
| 5098 | #Param picture Recorded drawing commands to play. ## |
| 5099 | #Param matrix Optional Matrix to rotate, scale, translate, and so on; or nullptr. ## |
| 5100 | #Param paint Optional Paint to apply transparency, filtering, and so on; or nullptr. ## |
| 5101 | |
| 5102 | #Example |
| 5103 | void draw(SkCanvas* canvas) {
|
| 5104 | SkPaint paint;
|
| 5105 | SkPictureRecorder recorder;
|
| 5106 | SkCanvas* recordingCanvas = recorder.beginRecording(50, 50);
|
| 5107 | for (auto color : { SK_ColorRED, SK_ColorBLUE, 0xff007f00 } ) {
|
| 5108 | paint.setColor(color);
|
| 5109 | recordingCanvas->drawRect({10, 10, 30, 40}, paint);
|
| 5110 | recordingCanvas->translate(10, 10);
|
| 5111 | recordingCanvas->scale(1.2f, 1.4f);
|
| 5112 | }
|
| 5113 | sk_sp<SkPicture> playback = recorder.finishRecordingAsPicture();
|
| 5114 | const SkPicture* playbackPtr = playback.get();
|
| 5115 | SkMatrix matrix;
|
| 5116 | matrix.reset();
|
| 5117 | for (auto alpha : { 70, 140, 210 } ) {
|
| 5118 | paint.setAlpha(alpha);
|
| 5119 | canvas->drawPicture(playbackPtr, &matrix, &paint);
|
| 5120 | matrix.preTranslate(70, 70);
|
| 5121 | }
|
| 5122 | } |
| 5123 | ## |
| 5124 | |
| 5125 | #ToDo incomplete ## |
| 5126 | |
| 5127 | ## |
| 5128 | |
| 5129 | # ------------------------------------------------------------------------------ |
| 5130 | |
| 5131 | #Method void drawPicture(const sk_sp<SkPicture>& picture, const SkMatrix* matrix, const SkPaint* paint) |
| 5132 | |
| 5133 | Draw Picture picture, using Clip and Matrix; |
| 5134 | transforming picture with Matrix matrix, if provided; |
| 5135 | and use Paint paint Color_Alpha, Color_Filter, Image_Filter, and Blend_Mode, if provided. |
| 5136 | |
| 5137 | matrix transformation is equivalent to: save(), concat(), drawPicture, restore(). |
| 5138 | paint use is equivalent to: saveLayer, drawPicture, restore(). |
| 5139 | |
| 5140 | #Param picture Recorded drawing commands to play. ## |
| 5141 | #Param matrix Optional Matrix to rotate, scale, translate, and so on; or nullptr. ## |
| 5142 | #Param paint Optional Paint to apply transparency, filtering, and so on; or nullptr. ## |
| 5143 | |
| 5144 | #Example |
| 5145 | void draw(SkCanvas* canvas) {
|
| 5146 | SkPaint paint;
|
| 5147 | SkPictureRecorder recorder;
|
| 5148 | SkCanvas* recordingCanvas = recorder.beginRecording(50, 50);
|
| 5149 | for (auto color : { SK_ColorRED, SK_ColorBLUE, 0xff007f00 } ) {
|
| 5150 | paint.setColor(color);
|
| 5151 | recordingCanvas->drawRect({10, 10, 30, 40}, paint);
|
| 5152 | recordingCanvas->translate(10, 10);
|
| 5153 | recordingCanvas->scale(1.2f, 1.4f);
|
| 5154 | }
|
| 5155 | sk_sp<SkPicture> playback = recorder.finishRecordingAsPicture();
|
| 5156 | SkMatrix matrix;
|
| 5157 | matrix.reset();
|
| 5158 | for (auto alpha : { 70, 140, 210 } ) {
|
| 5159 | paint.setAlpha(alpha);
|
| 5160 | canvas->drawPicture(playback, &matrix, &paint);
|
| 5161 | matrix.preTranslate(70, 70);
|
| 5162 | }
|
| 5163 | } |
| 5164 | ## |
| 5165 | |
| 5166 | #ToDo incomplete ## |
| 5167 | |
| 5168 | ## |
| 5169 | |
| 5170 | # ------------------------------------------------------------------------------ |
| 5171 | |
| 5172 | #Method void drawVertices(const SkVertices* vertices, SkBlendMode mode, const SkPaint& paint) |
| 5173 | |
| 5174 | Draw Vertices vertices, a triangle mesh, using Clip and Matrix. |
| 5175 | If Vertices_Texs and Vertices_Colors are defined in vertices, and Paint paint contains Shader, |
| 5176 | Blend_Mode mode combines Vertices_Colors with Shader. |
| 5177 | |
| 5178 | #Param vertices The triangle mesh to draw. ## |
| 5179 | #Param mode Combines Vertices_Colors with Shader, if both are present. ## |
| 5180 | #Param paint Specifies the Shader, used as Vertices texture, if present. ## |
| 5181 | |
| 5182 | #Example |
| 5183 | void draw(SkCanvas* canvas) {
|
| 5184 | SkPaint paint;
|
| 5185 | SkPoint points[] = { { 0, 0 }, { 250, 0 }, { 100, 100 }, { 0, 250 } };
|
| 5186 | SkColor colors[] = { SK_ColorRED, SK_ColorBLUE, SK_ColorYELLOW, SK_ColorCYAN };
|
| 5187 | auto vertices = SkVertices::MakeCopy(SkVertices::kTriangleFan_VertexMode,
|
| 5188 | SK_ARRAY_COUNT(points), points, nullptr, colors);
|
| 5189 | canvas->drawVertices(vertices.get(), SkBlendMode::kSrc, paint);
|
| 5190 | }
|
| 5191 | ## |
| 5192 | |
| 5193 | #ToDo incomplete ## |
| 5194 | |
| 5195 | ## |
| 5196 | |
| 5197 | # ------------------------------------------------------------------------------ |
| 5198 | |
| 5199 | #Method void drawVertices(const sk_sp<SkVertices>& vertices, SkBlendMode mode, const SkPaint& paint) |
| 5200 | |
| 5201 | Draw Vertices vertices, a triangle mesh, using Clip and Matrix. |
| 5202 | If Vertices_Texs and Vertices_Colors are defined in vertices, and Paint paint contains Shader, |
| 5203 | Blend_Mode mode combines Vertices_Colors with Shader. |
| 5204 | |
| 5205 | #Param vertices The triangle mesh to draw. ## |
| 5206 | #Param mode Combines Vertices_Colors with Shader, if both are present. ## |
| 5207 | #Param paint Specifies the Shader, used as Vertices texture, if present. ## |
| 5208 | |
| 5209 | #Example |
| 5210 | void draw(SkCanvas* canvas) {
|
| 5211 | SkPaint paint;
|
| 5212 | SkPoint points[] = { { 0, 0 }, { 250, 0 }, { 100, 100 }, { 0, 250 } };
|
| 5213 | SkPoint texs[] = { { 0, 0 }, { 0, 250 }, { 250, 250 }, { 250, 0 } };
|
| 5214 | SkColor colors[] = { SK_ColorRED, SK_ColorBLUE, SK_ColorYELLOW, SK_ColorCYAN };
|
| 5215 | paint.setShader(SkGradientShader::MakeLinear(points, colors, nullptr, 4,
|
| 5216 | SkShader::kClamp_TileMode));
|
| 5217 | auto vertices = SkVertices::MakeCopy(SkVertices::kTriangleFan_VertexMode,
|
| 5218 | SK_ARRAY_COUNT(points), points, texs, colors);
|
| 5219 | canvas->drawVertices(vertices.get(), SkBlendMode::kDarken, paint);
|
| 5220 | } |
| 5221 | ## |
| 5222 | |
| 5223 | #ToDo incomplete ## |
| 5224 | |
| 5225 | ## |
| 5226 | |
| 5227 | # ------------------------------------------------------------------------------ |
| 5228 | |
| 5229 | #Method void drawPatch(const SkPoint cubics[12], const SkColor colors[4], |
| 5230 | const SkPoint texCoords[4], SkBlendMode mode, const SkPaint& paint) |
| 5231 | |
| 5232 | Draw a cubic Coons patch: the interpolation of four cubics with shared corners, |
| 5233 | associating a color, and optionally a texture coordinate, with each corner. |
| 5234 | |
| 5235 | #ToDo can patch use image filter? ## |
| 5236 | |
| 5237 | The Coons patch uses Clip and Matrix, Paint paint's Shader, Color_Filter, Color_Alpha, |
| 5238 | Image_Filter, and Blend_Mode. If Shader is provided it is treated as the Coons |
| 5239 | patch texture; Blend_Mode mode combines Color colors and Shader if both are provided. |
| 5240 | |
| 5241 | #Param cubics Point array cubics specifying the four cubics starting at the top left corner, |
| 5242 | in clockwise order, sharing every fourth point. The last cubic ends at the first point. ## |
| 5243 | #Param colors Color array color associating colors with corners in top left, top right, bottom right, |
| 5244 | bottom left order. ## |
| 5245 | #Param texCoords Point array texCoords mapping Shader as texture to corners in same order, if paint |
| 5246 | contains Shader; or nullptr. ## |
| 5247 | #Param mode Blend_Mode for colors and Shader if present. ## |
| 5248 | #Param paint Shader, Color_Filter, Blend_Mode, used to draw. ## |
| 5249 | |
| 5250 | #Example |
| 5251 | #Image 5 |
| 5252 | void draw(SkCanvas* canvas) {
|
| 5253 | // SkBitmap source = cmbkygk;
|
| 5254 | SkPaint paint;
|
| 5255 | paint.setFilterQuality(kLow_SkFilterQuality);
|
| 5256 | paint.setAntiAlias(true);
|
| 5257 | SkPoint cubics[] = { { 3, 1 }, { 4, 2 }, { 5, 1 }, { 7, 3 },
|
| 5258 | /* { 7, 3 }, */ { 6, 4 }, { 7, 5 }, { 5, 7 },
|
| 5259 | /* { 5, 7 }, */ { 4, 6 }, { 3, 7 }, { 1, 5 },
|
| 5260 | /* { 1, 5 }, */ { 2, 4 }, { 1, 3 }, /* { 3, 1 } */ };
|
| 5261 | SkColor colors[] = { 0xbfff0000, 0xbf0000ff, 0xbfff00ff, 0xbf00ffff };
|
| 5262 | SkPoint texCoords[] = { { -30, -30 }, { 162, -30}, { 162, 162}, { -30, 162} };
|
| 5263 | paint.setShader(SkShader::MakeBitmapShader(source, SkShader::kClamp_TileMode,
|
| 5264 | SkShader::kClamp_TileMode, nullptr));
|
| 5265 | canvas->scale(15, 15);
|
| 5266 | for (auto blend : { SkBlendMode::kSrcOver, SkBlendMode::kModulate, SkBlendMode::kXor } ) {
|
| 5267 | canvas->drawPatch(cubics, colors, texCoords, blend, paint);
|
| 5268 | canvas->translate(4, 4);
|
| 5269 | }
|
| 5270 | } |
| 5271 | ## |
| 5272 | |
| 5273 | #ToDo incomplete ## |
| 5274 | |
| 5275 | ## |
| 5276 | |
| 5277 | # ------------------------------------------------------------------------------ |
| 5278 | |
| 5279 | #Method void drawPatch(const SkPoint cubics[12], const SkColor colors[4], |
| 5280 | const SkPoint texCoords[4], const SkPaint& paint) |
| 5281 | |
| 5282 | Draw a cubic Coons patch: the interpolation of four cubics with shared corners, |
| 5283 | associating a color, a texture coordinate, or both, with each corner. |
| 5284 | |
| 5285 | The Coons patch uses Clip and Matrix, Paint paint's Shader, Color_Filter, Color_Alpha, |
| 5286 | Image_Filter, (?) and Blend_Mode. If Shader is provided it is treated as the Coons |
| 5287 | patch texture. |
| 5288 | |
| 5289 | #Param cubics Point array cubics specifying the four cubics starting at the top left corner, |
| 5290 | in clockwise order, sharing every fourth point. The last cubic ends at the first point. ## |
| 5291 | #Param colors Color array color associating colors with corners in top left, top right, bottom right, |
| 5292 | bottom left order; or nullptr. ## |
| 5293 | #Param texCoords Point array texCoords mapping Shader as texture to corners in same order, if paint |
| 5294 | contains Shader; or nullptr. ## |
| 5295 | #Param paint Shader, Color_Filter, Blend_Mode, used to draw. ## |
| 5296 | |
| 5297 | #Example |
| 5298 | void draw(SkCanvas* canvas) {
|
| 5299 | SkPaint paint;
|
| 5300 | paint.setAntiAlias(true);
|
| 5301 | SkPoint cubics[] = { { 3, 1 }, { 4, 2 }, { 5, 1 }, { 7, 3 },
|
| 5302 | /* { 7, 3 }, */ { 6, 4 }, { 7, 5 }, { 5, 7 },
|
| 5303 | /* { 5, 7 }, */ { 4, 6 }, { 3, 7 }, { 1, 5 },
|
| 5304 | /* { 1, 5 }, */ { 2, 4 }, { 1, 3 }, /* { 3, 1 } */ };
|
| 5305 | SkColor colors[] = { SK_ColorRED, SK_ColorBLUE, SK_ColorYELLOW, SK_ColorCYAN };
|
| 5306 | canvas->scale(30, 30);
|
| 5307 | canvas->drawPatch(cubics, colors, nullptr, paint);
|
| 5308 | SkPoint text[] = { {3,0.9f}, {4,2.5f}, {5,0.9f}, {7.5f,3.2f}, {5.5f,4.2f},
|
| 5309 | {7.5f,5.2f}, {5,7.5f}, {4,5.9f}, {3,7.5f}, {0.5f,5.2f}, {2.5f,4.2f},
|
| 5310 | {0.5f,3.2f} };
|
| 5311 | paint.setTextSize(18.f / 30);
|
| 5312 | paint.setTextAlign(SkPaint::kCenter_Align);
|
| 5313 | for (int i = 0; i< 10; ++i) {
|
| 5314 | char digit = '0' + i;
|
| 5315 | canvas->drawText(&digit, 1, text[i].fX, text[i].fY, paint);
|
| 5316 | }
|
| 5317 | canvas->drawString("10", text[10].fX, text[10].fY, paint);
|
| 5318 | canvas->drawString("11", text[11].fX, text[11].fY, paint);
|
| 5319 | paint.setStyle(SkPaint::kStroke_Style);
|
| 5320 | canvas->drawPoints(SkCanvas::kPolygon_PointMode, 12, cubics, paint);
|
| 5321 | canvas->drawLine(cubics[11].fX, cubics[11].fY, cubics[0].fX, cubics[0].fY, paint);
|
| 5322 | } |
| 5323 | ## |
| 5324 | |
| 5325 | #Example |
| 5326 | #Image 6 |
| 5327 | void draw(SkCanvas* canvas) {
|
| 5328 | // SkBitmap source = checkerboard;
|
| 5329 | SkPaint paint;
|
| 5330 | paint.setFilterQuality(kLow_SkFilterQuality);
|
| 5331 | paint.setAntiAlias(true);
|
| 5332 | SkPoint cubics[] = { { 3, 1 }, { 4, 2 }, { 5, 1 }, { 7, 3 },
|
| 5333 | /* { 7, 3 }, */ { 6, 4 }, { 7, 5 }, { 5, 7 },
|
| 5334 | /* { 5, 7 }, */ { 4, 6 }, { 3, 7 }, { 1, 5 },
|
| 5335 | /* { 1, 5 }, */ { 2, 4 }, { 1, 3 }, /* { 3, 1 } */ };
|
| 5336 | SkPoint texCoords[] = { { 0, 0 }, { 0, 62}, { 62, 62}, { 62, 0 } };
|
| 5337 | paint.setShader(SkShader::MakeBitmapShader(source, SkShader::kClamp_TileMode,
|
| 5338 | SkShader::kClamp_TileMode, nullptr));
|
| 5339 | canvas->scale(30, 30);
|
| 5340 | canvas->drawPatch(cubics, nullptr, texCoords, paint);
|
| 5341 | } |
| 5342 | ## |
| 5343 | |
| 5344 | #ToDo incomplete ## |
| 5345 | |
| 5346 | ## |
| 5347 | |
| 5348 | # ------------------------------------------------------------------------------ |
| 5349 | |
| 5350 | #Method void drawAtlas(const SkImage* atlas, const SkRSXform xform[], const SkRect tex[], |
| 5351 | const SkColor colors[], int count, SkBlendMode mode, const SkRect* cullRect, |
| 5352 | const SkPaint* paint) |
| 5353 | |
| 5354 | Draw a set of sprites from atlas, using Clip, Matrix, and optional Paint paint. |
| 5355 | paint uses Anti-alias, Color_Alpha, Color_Filter, Image_Filter, and Blend_Mode to draw, if present. |
| 5356 | For each entry in the array, Rect tex locates sprite in atlas, and RSXform xform transforms it |
| 5357 | into destination space. |
| 5358 | xform, text, and colors if present, must contain count entries. |
| 5359 | Optional colors is applied for each sprite using Blend_Mode. |
| 5360 | Optional cullRect is a conservative bounds of all transformed sprites. |
| 5361 | If cullrect is outside of Clip, canvas can skip drawing. |
| 5362 | |
| 5363 | #Param atlas Image containing sprites. ## |
| 5364 | #Param xform RSXform mappings for sprites in atlas. ## |
| 5365 | #Param tex Rect locations of sprites in atlas. ## |
| 5366 | #Param colors Color, one per sprite, blended with sprite using Blend_Mode; or nullptr. ## |
| 5367 | #Param count Number of sprites to draw. ## |
| 5368 | #Param mode Blend_Mode combining colors and sprites. ## |
| 5369 | #Param cullRect Rect bounds of transformed sprites for efficient clipping; or nullptr. ## |
| 5370 | #Param paint Paint Color_Filter, Image_Filter, Blend_Mode, and so on; or nullptr. ## |
| 5371 | |
| 5372 | #Example |
| 5373 | #Image 3 |
| 5374 | void draw(SkCanvas* canvas) {
|
| 5375 | // SkBitmap source = mandrill;
|
| 5376 | SkRSXform xforms[] = { { .5f, 0, 0, 0 }, {0, .5f, 200, 100 } };
|
| 5377 | SkRect tex[] = { { 0, 0, 250, 250 }, { 0, 0, 250, 250 } };
|
| 5378 | SkColor colors[] = { 0x7f55aa00, 0x7f3333bf };
|
| 5379 | const SkImage* imagePtr = image.get();
|
| 5380 | canvas->drawAtlas(imagePtr, xforms, tex, colors, 2, SkBlendMode::kSrcOver, nullptr, nullptr);
|
| 5381 | } |
| 5382 | ## |
| 5383 | |
| 5384 | #ToDo incomplete ## |
| 5385 | |
| 5386 | ## |
| 5387 | |
| 5388 | # ------------------------------------------------------------------------------ |
| 5389 | |
| 5390 | #Method void drawAtlas(const sk_sp<SkImage>& atlas, const SkRSXform xform[], const SkRect tex[], |
| 5391 | const SkColor colors[], int count, SkBlendMode mode, const SkRect* cullRect, |
| 5392 | const SkPaint* paint) |
| 5393 | |
| 5394 | Draw a set of sprites from atlas, using Clip, Matrix, and optional Paint paint. |
| 5395 | paint uses Anti-alias, Color_Alpha, Color_Filter, Image_Filter, and Blend_Mode to draw, if present. |
| 5396 | For each entry in the array, Rect tex locates sprite in atlas, and RSXform xform transforms it |
| 5397 | into destination space. |
| 5398 | xform, text, and colors if present, must contain count entries. |
| 5399 | Optional colors is applied for each sprite using Blend_Mode. |
| 5400 | Optional cullRect is a conservative bounds of all transformed sprites. |
| 5401 | If cullrect is outside of Clip, canvas can skip drawing. |
| 5402 | |
| 5403 | #Param atlas Image containing sprites. ## |
| 5404 | #Param xform RSXform mappings for sprites in atlas. ## |
| 5405 | #Param tex Rect locations of sprites in atlas. ## |
| 5406 | #Param colors Color, one per sprite, blended with sprite using Blend_Mode; or nullptr. ## |
| 5407 | #Param count Number of sprites to draw. ## |
| 5408 | #Param mode Blend_Mode combining colors and sprites. ## |
| 5409 | #Param cullRect Rect bounds of transformed sprites for efficient clipping; or nullptr. ## |
| 5410 | #Param paint Paint Color_Filter, Image_Filter, Blend_Mode, and so on; or nullptr. ## |
| 5411 | |
| 5412 | #Example |
| 5413 | #Image 3 |
| 5414 | void draw(SkCanvas* canvas) {
|
| 5415 | // SkBitmap source = mandrill;
|
| 5416 | SkRSXform xforms[] = { { .5f, 0, 0, 0 }, {0, .5f, 200, 100 } };
|
| 5417 | SkRect tex[] = { { 0, 0, 250, 250 }, { 0, 0, 250, 250 } };
|
| 5418 | SkColor colors[] = { 0x7f55aa00, 0x7f3333bf };
|
| 5419 | SkPaint paint;
|
| 5420 | paint.setAlpha(127);
|
| 5421 | canvas->drawAtlas(image, xforms, tex, colors, 2, SkBlendMode::kPlus, nullptr, &paint);
|
| 5422 | } |
| 5423 | ## |
| 5424 | |
| 5425 | #ToDo bug in example on cpu side, gpu looks ok ## |
| 5426 | |
| 5427 | ## |
| 5428 | |
| 5429 | # ------------------------------------------------------------------------------ |
| 5430 | |
| 5431 | #Method void drawAtlas(const SkImage* atlas, const SkRSXform xform[], const SkRect tex[], int count, |
| 5432 | const SkRect* cullRect, const SkPaint* paint) |
| 5433 | |
| 5434 | Draw a set of sprites from atlas, using Clip, Matrix, and optional Paint paint. |
| 5435 | paint uses Anti-alias, Color_Alpha, Color_Filter, Image_Filter, and Blend_Mode to draw, if present. |
| 5436 | For each entry in the array, Rect tex locates sprite in atlas, and RSXform xform transforms it |
| 5437 | into destination space. |
| 5438 | xform and text must contain count entries. |
| 5439 | Optional cullRect is a conservative bounds of all transformed sprites. |
| 5440 | If cullrect is outside of Clip, canvas can skip drawing. |
| 5441 | |
| 5442 | #Param atlas Image containing sprites. ## |
| 5443 | #Param xform RSXform mappings for sprites in atlas. ## |
| 5444 | #Param tex Rect locations of sprites in atlas. ## |
| 5445 | #Param count Number of sprites to draw. ## |
| 5446 | #Param cullRect Rect bounds of transformed sprites for efficient clipping; or nullptr. ## |
| 5447 | #Param paint Paint Color_Filter, Image_Filter, Blend_Mode, and so on; or nullptr. ## |
| 5448 | |
| 5449 | #Example |
| 5450 | #Image 3 |
| 5451 | void draw(SkCanvas* canvas) {
|
| 5452 | // sk_sp<SkImage> image = mandrill;
|
| 5453 | SkRSXform xforms[] = { { .5f, 0, 0, 0 }, {0, .5f, 200, 100 } };
|
| 5454 | SkRect tex[] = { { 0, 0, 250, 250 }, { 0, 0, 250, 250 } };
|
| 5455 | const SkImage* imagePtr = image.get();
|
| 5456 | canvas->drawAtlas(imagePtr, xforms, tex, 2, nullptr, nullptr);
|
| 5457 | } |
| 5458 | ## |
| 5459 | |
| 5460 | #ToDo incomplete ## |
| 5461 | |
| 5462 | ## |
| 5463 | |
| 5464 | # ------------------------------------------------------------------------------ |
| 5465 | |
| 5466 | #Method void drawAtlas(const sk_sp<SkImage>& atlas, const SkRSXform xform[], const SkRect tex[], |
| 5467 | int count, const SkRect* cullRect, const SkPaint* paint) |
| 5468 | |
| 5469 | Draw a set of sprites from atlas, using Clip, Matrix, and optional Paint paint. |
| 5470 | paint uses Anti-alias, Color_Alpha, Color_Filter, Image_Filter, and Blend_Mode to draw, if present. |
| 5471 | For each entry in the array, Rect tex locates sprite in atlas, and RSXform xform transforms it |
| 5472 | into destination space. |
| 5473 | xform and text must contain count entries. |
| 5474 | Optional cullRect is a conservative bounds of all transformed sprites. |
| 5475 | If cullrect is outside of Clip, canvas can skip drawing. |
| 5476 | |
| 5477 | #Param atlas Image containing sprites. ## |
| 5478 | #Param xform RSXform mappings for sprites in atlas. ## |
| 5479 | #Param tex Rect locations of sprites in atlas. ## |
| 5480 | #Param count Number of sprites to draw. ## |
| 5481 | #Param cullRect Rect bounds of transformed sprites for efficient clipping; or nullptr. ## |
| 5482 | #Param paint Paint Color_Filter, Image_Filter, Blend_Mode, and so on; or nullptr. ## |
| 5483 | |
| 5484 | #Example |
| 5485 | #Image 3 |
| 5486 | void draw(SkCanvas* canvas) {
|
| 5487 | // sk_sp<SkImage> image = mandrill;
|
| 5488 | SkRSXform xforms[] = { { 1, 0, 0, 0 }, {0, 1, 300, 100 } };
|
| 5489 | SkRect tex[] = { { 0, 0, 200, 200 }, { 200, 0, 400, 200 } };
|
| 5490 | canvas->drawAtlas(image, xforms, tex, 2, nullptr, nullptr);
|
| 5491 | } |
| 5492 | ## |
| 5493 | |
| 5494 | #ToDo incomplete ## |
| 5495 | |
| 5496 | ## |
| 5497 | |
| 5498 | # ------------------------------------------------------------------------------ |
| 5499 | |
| 5500 | #Method void drawDrawable(SkDrawable* drawable, const SkMatrix* matrix = NULL) |
| 5501 | |
| 5502 | Draw Drawable drawable using Clip and Matrix, concatenated with |
| 5503 | optional matrix. |
| 5504 | |
| 5505 | If Canvas has an asynchronous implementation, as is the case |
| 5506 | when it is recording into Picture, then drawable will be referenced, |
| 5507 | so that SkDrawable::draw() can be called when the operation is finalized. To force |
| 5508 | immediate drawing, call SkDrawable::draw() instead. |
| 5509 | |
| 5510 | #Param drawable Custom struct encapsulating drawing commands. ## |
| 5511 | #Param matrix Transformation applied to drawing; or nullptr. ## |
| 5512 | |
| 5513 | #Example |
| 5514 | #Height 100 |
| 5515 | #Function |
| 5516 | struct MyDrawable : public SkDrawable {
|
| 5517 | SkRect onGetBounds() override { return SkRect::MakeWH(50, 100); }
|
| 5518 |
|
| 5519 | void onDraw(SkCanvas* canvas) override {
|
| 5520 | SkPath path;
|
| 5521 | path.conicTo(10, 90, 50, 90, 0.9f);
|
| 5522 | SkPaint paint;
|
| 5523 | paint.setColor(SK_ColorBLUE);
|
| 5524 | canvas->drawRect(path.getBounds(), paint);
|
| 5525 | paint.setAntiAlias(true);
|
| 5526 | paint.setColor(SK_ColorWHITE);
|
| 5527 | canvas->drawPath(path, paint);
|
| 5528 | }
|
| 5529 | };
|
| 5530 |
|
| 5531 | #Function ##
|
| 5532 | void draw(SkCanvas* canvas) {
|
| 5533 | sk_sp<SkDrawable> drawable(new MyDrawable);
|
| 5534 | SkMatrix matrix;
|
| 5535 | matrix.setTranslate(10, 10);
|
| 5536 | canvas->drawDrawable(drawable.get(), &matrix);
|
| 5537 | } |
| 5538 | ## |
| 5539 | |
| 5540 | #ToDo incomplete ## |
| 5541 | |
| 5542 | ## |
| 5543 | |
| 5544 | # ------------------------------------------------------------------------------ |
| 5545 | |
| 5546 | #Method void drawDrawable(SkDrawable* drawable, SkScalar x, SkScalar y) |
| 5547 | |
| 5548 | Draw Drawable drawable using Clip and Matrix, offset by (x, y). |
| 5549 | |
| 5550 | If Canvas has an asynchronous implementation, as is the case |
| 5551 | when it is recording into Picture, then drawable will be referenced, |
| 5552 | so that SkDrawable::draw() can be called when the operation is finalized. To force |
| 5553 | immediate drawing, call SkDrawable::draw() instead. |
| 5554 | |
| 5555 | #Param drawable Custom struct encapsulating drawing commands. ## |
| 5556 | #Param x Offset into Canvas writable pixels in x. ## |
| 5557 | #Param y Offset into Canvas writable pixels in y. ## |
| 5558 | |
| 5559 | #Example |
| 5560 | #Height 100 |
| 5561 | #Function |
| 5562 | struct MyDrawable : public SkDrawable {
|
| 5563 | SkRect onGetBounds() override { return SkRect::MakeWH(50, 100); }
|
| 5564 |
|
| 5565 | void onDraw(SkCanvas* canvas) override {
|
| 5566 | SkPath path;
|
| 5567 | path.conicTo(10, 90, 50, 90, 0.9f);
|
| 5568 | SkPaint paint;
|
| 5569 | paint.setColor(SK_ColorBLUE);
|
| 5570 | canvas->drawRect(path.getBounds(), paint);
|
| 5571 | paint.setAntiAlias(true);
|
| 5572 | paint.setColor(SK_ColorWHITE);
|
| 5573 | canvas->drawPath(path, paint);
|
| 5574 | }
|
| 5575 | };
|
| 5576 |
|
| 5577 | #Function ##
|
| 5578 | void draw(SkCanvas* canvas) {
|
| 5579 | sk_sp<SkDrawable> drawable(new MyDrawable);
|
| 5580 | canvas->drawDrawable(drawable.get(), 10, 10);
|
| 5581 | } |
| 5582 | ## |
| 5583 | |
| 5584 | #ToDo incomplete ## |
| 5585 | |
| 5586 | ## |
| 5587 | |
| 5588 | # ------------------------------------------------------------------------------ |
| 5589 | |
| 5590 | #Method void drawAnnotation(const SkRect& rect, const char key[], SkData* value) |
| 5591 | |
| 5592 | Associate Rect on Canvas when an annotation; a key-value pair, where the key is |
| 5593 | a null-terminated utf8 string, and optional value is stored as Data. |
| 5594 | |
| 5595 | Only some canvas implementations, such as recording to Picture, or drawing to |
| 5596 | Document_PDF, use annotations. |
| 5597 | |
| 5598 | #Param rect Rect extent of canvas to annotate. ## |
| 5599 | #Param key String used for lookup. ## |
| 5600 | #Param value Data holding value stored in annotation. ## |
| 5601 | |
| 5602 | #Example |
| 5603 | #Height 1 |
| 5604 | const char text[] = "Click this link!"; |
| 5605 | SkRect bounds; |
| 5606 | SkPaint paint; |
| 5607 | paint.setTextSize(40); |
| 5608 | (void)paint.measureText(text, strlen(text), &bounds); |
| 5609 | const char url[] = "https://www.google.com/"; |
| 5610 | sk_sp<SkData> urlData(SkData::MakeWithCString(url)); |
| 5611 | canvas->drawAnnotation(bounds, "url_key", urlData.get()); |
| 5612 | ## |
| 5613 | |
| 5614 | #ToDo incomplete ## |
| 5615 | |
| 5616 | ## |
| 5617 | |
| 5618 | # ------------------------------------------------------------------------------ |
| 5619 | |
| 5620 | #Method void drawAnnotation(const SkRect& rect, const char key[], const sk_sp<SkData>& value) |
| 5621 | |
| 5622 | Associate Rect on Canvas when an annotation; a key-value pair, where the key is |
| 5623 | a null-terminated utf8 string, and optional value is stored as Data. |
| 5624 | |
| 5625 | Only some canvas implementations, such as recording to Picture, or drawing to |
| 5626 | Document_PDF, use annotations. |
| 5627 | |
| 5628 | #Param rect Rect extent of canvas to annotate. ## |
| 5629 | #Param key String used for lookup. ## |
| 5630 | #Param value Data holding value stored in annotation. ## |
| 5631 | |
| 5632 | #Example |
| 5633 | #Height 1 |
| 5634 | const char text[] = "Click this link!"; |
| 5635 | SkRect bounds; |
| 5636 | SkPaint paint; |
| 5637 | paint.setTextSize(40); |
| 5638 | (void)paint.measureText(text, strlen(text), &bounds); |
| 5639 | const char url[] = "https://www.google.com/"; |
| 5640 | sk_sp<SkData> urlData(SkData::MakeWithCString(url)); |
| 5641 | canvas->drawAnnotation(bounds, "url_key", urlData.get()); |
| 5642 | ## |
| 5643 | |
| 5644 | #ToDo incomplete ## |
| 5645 | |
| 5646 | ## |
| 5647 | |
| 5648 | #Method SkDrawFilter* getDrawFilter() const |
| 5649 | |
| 5650 | Legacy call to be deprecated. |
| 5651 | |
| 5652 | #Deprecated |
| 5653 | ## |
| 5654 | |
| 5655 | ## |
| 5656 | |
| 5657 | #Method virtual SkDrawFilter* setDrawFilter(SkDrawFilter* filter) |
| 5658 | |
| 5659 | Legacy call to be deprecated. |
| 5660 | |
| 5661 | #Deprecated |
| 5662 | ## |
| 5663 | |
| 5664 | ## |
| 5665 | |
| 5666 | # ------------------------------------------------------------------------------ |
| 5667 | |
| 5668 | #Method virtual bool isClipEmpty() const |
| 5669 | |
| 5670 | Returns true if Clip is empty; that is, nothing will draw. |
| 5671 | |
| 5672 | isClipEmpty may do work when called; it should not be called |
| 5673 | more often than needed. However, once called, subsequent calls perform no |
| 5674 | work until Clip changes. |
| 5675 | |
| 5676 | #Return true if Clip is empty. ## |
| 5677 | |
| 5678 | #Example |
| 5679 | void draw(SkCanvas* canvas) {
|
| 5680 | SkDebugf("clip is%s empty\n", canvas->isClipEmpty() ? "" : " not");
|
| 5681 | SkPath path;
|
| 5682 | canvas->clipPath(path);
|
| 5683 | SkDebugf("clip is%s empty\n", canvas->isClipEmpty() ? "" : " not");
|
| 5684 | } |
| 5685 | #StdOut |
| 5686 | clip is not empty
|
| 5687 | clip is empty |
| 5688 | ## |
| 5689 | ## |
| 5690 | |
| 5691 | #ToDo incomplete ## |
| 5692 | |
| 5693 | ## |
| 5694 | |
| 5695 | # ------------------------------------------------------------------------------ |
| 5696 | |
| 5697 | #Method virtual bool isClipRect() const |
| 5698 | |
| 5699 | Returns true if Clip is Rect and not empty. |
| 5700 | Returns false if the clip is empty, or if it is not Rect. |
| 5701 | |
| 5702 | #Return true if Clip is Rect and not empty. ## |
| 5703 | |
| 5704 | #Example |
| 5705 | void draw(SkCanvas* canvas) {
|
| 5706 | SkDebugf("clip is%s rect\n", canvas->isClipRect() ? "" : " not");
|
| 5707 | canvas->clipRect({0, 0, 0, 0});
|
| 5708 | SkDebugf("clip is%s rect\n", canvas->isClipRect() ? "" : " not");
|
| 5709 | } |
| 5710 | #StdOut |
| 5711 | clip is rect
|
| 5712 | clip is not rect |
| 5713 | ## |
| 5714 | ## |
| 5715 | |
| 5716 | #ToDo incomplete ## |
| 5717 | |
| 5718 | ## |
| 5719 | |
| 5720 | #Class SkCanvas ## |
| 5721 | #Topic Canvas ## |