1// helper JS that could be used anywhere in the glue code 2 3function clamp(c) { 4 return Math.round(Math.max(0, Math.min(c || 0, 255))); 5} 6 7// Colors are just a 32 bit number with 8 bits each of a, r, g, b 8// The API is the same as CSS's representation of color rgba(), that is 9// r,g,b are 0-255, and a is 0.0 to 1.0. 10// if a is omitted, it will be assumed to be 1.0 11CanvasKit.Color = function(r, g, b, a) { 12 if (a === undefined) { 13 a = 1; 14 } 15 // The >>> 0 converts the signed int to an unsigned int. Skia's 16 // SkColor object is an unsigned int. 17 // https://stackoverflow.com/a/14891172 18 return ((clamp(a*255) << 24) | (clamp(r) << 16) | (clamp(g) << 8) | (clamp(b) << 0)) >>> 0; 19} 20 21// returns [r, g, b, a] from a color 22// where a is scaled between 0 and 1.0 23CanvasKit.getColorComponents = function(color) { 24 return [ 25 (color >> 16) & 0xFF, 26 (color >> 8) & 0xFF, 27 (color >> 0) & 0xFF, 28 ((color >> 24) & 0xFF) / 255, 29 ] 30} 31 32CanvasKit.multiplyByAlpha = function(color, alpha) { 33 if (alpha === 1) { 34 return color; 35 } 36 // extract as int from 0 to 255 37 var a = (color >> 24) & 0xFF; 38 a *= alpha; 39 // mask off the old alpha 40 color &= 0xFFFFFF; 41 // back to unsigned int to match SkColor. 42 return (clamp(a) << 24 | color) >>> 0; 43} 44 45function radiansToDegrees(rad) { 46 return (rad / Math.PI) * 180; 47} 48 49function degreesToRadians(deg) { 50 return (deg / 180) * Math.PI; 51} 52 53// See https://stackoverflow.com/a/31090240 54// This contraption keeps closure from minifying away the check 55// if btoa is defined *and* prevents runtime "btoa" or "window" is not defined. 56// Defined outside any scopes to make it available in all files. 57var isNode = !(new Function("try {return this===window;}catch(e){ return false;}")()); 58 59function almostEqual(floata, floatb) { 60 return Math.abs(floata - floatb) < 0.00001; 61} 62 63 64var nullptr = 0; // emscripten doesn't like to take null as uintptr_t 65 66// arr can be a normal JS array or a TypedArray 67// dest is something like CanvasKit.HEAPF32 68// ptr can be optionally provided if the memory was already allocated. 69function copy1dArray(arr, dest, ptr) { 70 if (!arr || !arr.length) { 71 return nullptr; 72 } 73 if (!ptr) { 74 ptr = CanvasKit._malloc(arr.length * dest.BYTES_PER_ELEMENT); 75 } 76 // In c++ terms, the WASM heap is a uint8_t*, a long buffer/array of single 77 // byte elements. When we run _malloc, we always get an offset/pointer into 78 // that block of memory. 79 // CanvasKit exposes some different views to make it easier to work with 80 // different types. HEAPF32 for example, exposes it as a float* 81 // However, to make the ptr line up, we have to do some pointer arithmetic. 82 // Concretely, we need to convert ptr to go from an index into a 1-byte-wide 83 // buffer to an index into a 4-byte-wide buffer (in the case of HEAPF32) 84 // and thus we divide ptr by 4. 85 dest.set(arr, ptr / dest.BYTES_PER_ELEMENT); 86 return ptr; 87} 88 89// arr should be a non-jagged 2d JS array (TypedArrays can't be nested 90// inside themselves.) 91// dest is something like CanvasKit.HEAPF32 92// ptr can be optionally provided if the memory was already allocated. 93function copy2dArray(arr, dest, ptr) { 94 if (!arr || !arr.length) { 95 return nullptr; 96 } 97 if (!ptr) { 98 ptr = CanvasKit._malloc(arr.length * arr[0].length * dest.BYTES_PER_ELEMENT); 99 } 100 var idx = 0; 101 var adjustedPtr = ptr / dest.BYTES_PER_ELEMENT; 102 for (var r = 0; r < arr.length; r++) { 103 for (var c = 0; c < arr[0].length; c++) { 104 dest[adjustedPtr + idx] = arr[r][c]; 105 idx++; 106 } 107 } 108 return ptr; 109} 110 111// arr should be a non-jagged 3d JS array (TypedArrays can't be nested 112// inside themselves.) 113// dest is something like CanvasKit.HEAPF32 114// ptr can be optionally provided if the memory was already allocated. 115function copy3dArray(arr, dest, ptr) { 116 if (!arr || !arr.length || !arr[0].length) { 117 return nullptr; 118 } 119 if (!ptr) { 120 ptr = CanvasKit._malloc(arr.length * arr[0].length * arr[0][0].length * dest.BYTES_PER_ELEMENT); 121 } 122 var idx = 0; 123 var adjustedPtr = ptr / dest.BYTES_PER_ELEMENT; 124 for (var x = 0; x < arr.length; x++) { 125 for (var y = 0; y < arr[0].length; y++) { 126 for (var z = 0; z < arr[0][0].length; z++) { 127 dest[adjustedPtr + idx] = arr[x][y][z]; 128 idx++; 129 } 130 } 131 } 132 return ptr; 133} 134 135// Caching the Float32Arrays can save having to reallocate them 136// over and over again. 137var Float32ArrayCache = {}; 138 139// Takes a 2D array of commands and puts them into the WASM heap 140// as a 1D array. This allows them to referenced from the C++ code. 141// Returns a 2 element array, with the first item being essentially a 142// pointer to the array and the second item being the length of 143// the new 1D array. 144// 145// Example usage: 146// let cmds = [ 147// [CanvasKit.MOVE_VERB, 0, 10], 148// [CanvasKit.LINE_VERB, 30, 40], 149// [CanvasKit.QUAD_VERB, 20, 50, 45, 60], 150// ]; 151function loadCmdsTypedArray(arr) { 152 var len = 0; 153 for (var r = 0; r < arr.length; r++) { 154 len += arr[r].length; 155 } 156 157 var ta; 158 if (Float32ArrayCache[len]) { 159 ta = Float32ArrayCache[len]; 160 } else { 161 ta = new Float32Array(len); 162 Float32ArrayCache[len] = ta; 163 } 164 // Flatten into a 1d array 165 var i = 0; 166 for (var r = 0; r < arr.length; r++) { 167 for (var c = 0; c < arr[r].length; c++) { 168 var item = arr[r][c]; 169 ta[i] = item; 170 i++; 171 } 172 } 173 174 var ptr = copy1dArray(ta, CanvasKit.HEAPF32); 175 return [ptr, len]; 176} 177 178function saveBytesToFile(bytes, fileName) { 179 if (!isNode) { 180 // https://stackoverflow.com/a/32094834 181 var blob = new Blob([bytes], {type: 'application/octet-stream'}); 182 url = window.URL.createObjectURL(blob); 183 var a = document.createElement('a'); 184 document.body.appendChild(a); 185 a.href = url; 186 a.download = fileName; 187 a.click(); 188 // clean up after because FF might not download it synchronously 189 setTimeout(function() { 190 URL.revokeObjectURL(url); 191 a.remove(); 192 }, 50); 193 } else { 194 var fs = require('fs'); 195 // https://stackoverflow.com/a/42006750 196 // https://stackoverflow.com/a/47018122 197 fs.writeFile(fileName, new Buffer(bytes), function(err) { 198 if (err) throw err; 199 }); 200 } 201} 202/** 203 * Generic helper for dealing with an array of four floats. 204 */ 205CanvasKit.FourFloatArrayHelper = function() { 206 this._floats = []; 207 this._ptr = null; 208 209 Object.defineProperty(this, 'length', { 210 enumerable: true, 211 get: function() { 212 return this._floats.length / 4; 213 }, 214 }); 215} 216 217/** 218 * push the four floats onto the end of the array - if build() has already 219 * been called, the call will return without modifying anything. 220 */ 221CanvasKit.FourFloatArrayHelper.prototype.push = function(f1, f2, f3, f4) { 222 if (this._ptr) { 223 SkDebug('Cannot push more points - already built'); 224 return; 225 } 226 this._floats.push(f1, f2, f3, f4); 227} 228 229/** 230 * Set the four floats at a given index - if build() has already 231 * been called, the WASM memory will be written to directly. 232 */ 233CanvasKit.FourFloatArrayHelper.prototype.set = function(idx, f1, f2, f3, f4) { 234 if (idx < 0 || idx >= this._floats.length/4) { 235 SkDebug('Cannot set index ' + idx + ', it is out of range', this._floats.length/4); 236 return; 237 } 238 idx *= 4; 239 var BYTES_PER_ELEMENT = 4; 240 if (this._ptr) { 241 // convert this._ptr from uint8_t* to SkScalar* by dividing by 4 242 var floatPtr = (this._ptr / BYTES_PER_ELEMENT) + idx; 243 CanvasKit.HEAPF32[floatPtr] = f1; 244 CanvasKit.HEAPF32[floatPtr + 1] = f2; 245 CanvasKit.HEAPF32[floatPtr + 2] = f3; 246 CanvasKit.HEAPF32[floatPtr + 3] = f4; 247 return; 248 } 249 this._floats[idx] = f1; 250 this._floats[idx + 1] = f2; 251 this._floats[idx + 2] = f3; 252 this._floats[idx + 3] = f4; 253} 254 255/** 256 * Copies the float data to the WASM memory and returns a pointer 257 * to that allocated memory. Once build has been called, this 258 * float array cannot be made bigger. 259 */ 260CanvasKit.FourFloatArrayHelper.prototype.build = function() { 261 if (this._ptr) { 262 return this._ptr; 263 } 264 this._ptr = copy1dArray(this._floats, CanvasKit.HEAPF32); 265 return this._ptr; 266} 267 268/** 269 * Frees the wasm memory associated with this array. Of note, 270 * the points are not removed, so push/set/build can all 271 * be called to make a newly allocated (possibly bigger) 272 * float array. 273 */ 274CanvasKit.FourFloatArrayHelper.prototype.delete = function() { 275 if (this._ptr) { 276 CanvasKit._free(this._ptr); 277 this._ptr = null; 278 } 279} 280 281/** 282 * Generic helper for dealing with an array of unsigned ints. 283 */ 284CanvasKit.OneUIntArrayHelper = function() { 285 this._uints = []; 286 this._ptr = null; 287 288 Object.defineProperty(this, 'length', { 289 enumerable: true, 290 get: function() { 291 return this._uints.length; 292 }, 293 }); 294} 295 296/** 297 * push the unsigned int onto the end of the array - if build() has already 298 * been called, the call will return without modifying anything. 299 */ 300CanvasKit.OneUIntArrayHelper.prototype.push = function(u) { 301 if (this._ptr) { 302 SkDebug('Cannot push more points - already built'); 303 return; 304 } 305 this._uints.push(u); 306} 307 308/** 309 * Set the uint at a given index - if build() has already 310 * been called, the WASM memory will be written to directly. 311 */ 312CanvasKit.OneUIntArrayHelper.prototype.set = function(idx, u) { 313 if (idx < 0 || idx >= this._uints.length) { 314 SkDebug('Cannot set index ' + idx + ', it is out of range', this._uints.length); 315 return; 316 } 317 idx *= 4; 318 var BYTES_PER_ELEMENT = 4; 319 if (this._ptr) { 320 // convert this._ptr from uint8_t* to SkScalar* by dividing by 4 321 var uintPtr = (this._ptr / BYTES_PER_ELEMENT) + idx; 322 CanvasKit.HEAPU32[uintPtr] = u; 323 return; 324 } 325 this._uints[idx] = u; 326} 327 328/** 329 * Copies the uint data to the WASM memory and returns a pointer 330 * to that allocated memory. Once build has been called, this 331 * unit array cannot be made bigger. 332 */ 333CanvasKit.OneUIntArrayHelper.prototype.build = function() { 334 if (this._ptr) { 335 return this._ptr; 336 } 337 this._ptr = copy1dArray(this._uints, CanvasKit.HEAPU32); 338 return this._ptr; 339} 340 341/** 342 * Frees the wasm memory associated with this array. Of note, 343 * the points are not removed, so push/set/build can all 344 * be called to make a newly allocated (possibly bigger) 345 * uint array. 346 */ 347CanvasKit.OneUIntArrayHelper.prototype.delete = function() { 348 if (this._ptr) { 349 CanvasKit._free(this._ptr); 350 this._ptr = null; 351 } 352} 353 354/** 355 * Helper for building an array of SkRects (which are just structs 356 * of 4 floats). 357 * 358 * It can be more performant to use this helper, as 359 * the C++-side array is only allocated once (on the first call) 360 * to build. Subsequent set() operations operate directly on 361 * the C++-side array, avoiding having to re-allocate (and free) 362 * the array every time. 363 * 364 * Input points are taken as left, top, right, bottom 365 */ 366CanvasKit.SkRectBuilder = CanvasKit.FourFloatArrayHelper; 367/** 368 * Helper for building an array of RSXForms (which are just structs 369 * of 4 floats). 370 * 371 * It can be more performant to use this helper, as 372 * the C++-side array is only allocated once (on the first call) 373 * to build. Subsequent set() operations operate directly on 374 * the C++-side array, avoiding having to re-allocate (and free) 375 * the array every time. 376 * 377 * An RSXForm is a compressed form of a rotation+scale matrix. 378 * 379 * [ scos -ssin tx ] 380 * [ ssin scos ty ] 381 * [ 0 0 1 ] 382 * 383 * Input points are taken as scos, ssin, tx, ty 384 */ 385CanvasKit.RSXFormBuilder = CanvasKit.FourFloatArrayHelper; 386 387/** 388 * Helper for building an array of SkColor 389 * 390 * It can be more performant to use this helper, as 391 * the C++-side array is only allocated once (on the first call) 392 * to build. Subsequent set() operations operate directly on 393 * the C++-side array, avoiding having to re-allocate (and free) 394 * the array every time. 395 */ 396CanvasKit.SkColorBuilder = CanvasKit.OneUIntArrayHelper; 397