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 return (clamp(a*255) << 24) | (clamp(r) << 16) | (clamp(g) << 8) | (clamp(b) << 0); 16} 17 18// returns [r, g, b, a] from a color 19// where a is scaled between 0 and 1.0 20CanvasKit.getColorComponents = function(color) { 21 return [ 22 (color >> 16) & 0xFF, 23 (color >> 8) & 0xFF, 24 (color >> 0) & 0xFF, 25 ((color >> 24) & 0xFF) / 255, 26 ] 27} 28 29CanvasKit.multiplyByAlpha = function(color, alpha) { 30 if (alpha === 1) { 31 return color; 32 } 33 // extract as int from 0 to 255 34 var a = (color >> 24) & 0xFF; 35 a *= alpha; 36 // mask off the old alpha 37 color &= 0xFFFFFF; 38 return clamp(a) << 24 | color; 39} 40 41function radiansToDegrees(rad) { 42 return (rad / Math.PI) * 180; 43} 44 45function degreesToRadians(deg) { 46 return (deg / 180) * Math.PI; 47} 48 49// See https://stackoverflow.com/a/31090240 50// This contraption keeps closure from minifying away the check 51// if btoa is defined *and* prevents runtime "btoa" or "window" is not defined. 52// Defined outside any scopes to make it available in all files. 53var isNode = !(new Function("try {return this===window;}catch(e){ return false;}")()); 54 55function almostEqual(floata, floatb) { 56 return Math.abs(floata - floatb) < 0.00001; 57} 58 59 60var nullptr = 0; // emscripten doesn't like to take null as uintptr_t 61 62// arr can be a normal JS array or a TypedArray 63// dest is something like CanvasKit.HEAPF32 64function copy1dArray(arr, dest) { 65 if (!arr || !arr.length) { 66 return nullptr; 67 } 68 var ptr = CanvasKit._malloc(arr.length * dest.BYTES_PER_ELEMENT); 69 // In c++ terms, the WASM heap is a uint8_t*, a long buffer/array of single 70 // byte elements. When we run _malloc, we always get an offset/pointer into 71 // that block of memory. 72 // CanvasKit exposes some different views to make it easier to work with 73 // different types. HEAPF32 for example, exposes it as a float* 74 // However, to make the ptr line up, we have to do some pointer arithmetic. 75 // Concretely, we need to convert ptr to go from an index into a 1-byte-wide 76 // buffer to an index into a 4-byte-wide buffer (in the case of HEAPF32) 77 // and thus we divide ptr by 4. 78 dest.set(arr, ptr / dest.BYTES_PER_ELEMENT); 79 return ptr; 80} 81 82// arr should be a non-jagged 2d JS array (TypedArrays can't be nested 83// inside themselves.) 84// dest is something like CanvasKit.HEAPF32 85function copy2dArray(arr, dest) { 86 if (!arr || !arr.length) { 87 return nullptr; 88 } 89 var ptr = CanvasKit._malloc(arr.length * arr[0].length * dest.BYTES_PER_ELEMENT); 90 var idx = 0; 91 var adjustedPtr = ptr / dest.BYTES_PER_ELEMENT; 92 for (var r = 0; r < arr.length; r++) { 93 for (var c = 0; c < arr[0].length; c++) { 94 dest[adjustedPtr + idx] = arr[r][c]; 95 idx++; 96 } 97 } 98 return ptr; 99} 100 101// arr should be a non-jagged 3d JS array (TypedArrays can't be nested 102// inside themselves.) 103// dest is something like CanvasKit.HEAPF32 104function copy3dArray(arr, dest) { 105 if (!arr || !arr.length || !arr[0].length) { 106 return nullptr; 107 } 108 var ptr = CanvasKit._malloc(arr.length * arr[0].length * arr[0][0].length * dest.BYTES_PER_ELEMENT); 109 var idx = 0; 110 var adjustedPtr = ptr / dest.BYTES_PER_ELEMENT; 111 for (var x = 0; x < arr.length; x++) { 112 for (var y = 0; y < arr[0].length; y++) { 113 for (var z = 0; z < arr[0][0].length; z++) { 114 dest[adjustedPtr + idx] = arr[x][y][z]; 115 idx++; 116 } 117 } 118 } 119 return ptr; 120} 121 122// Caching the Float32Arrays can save having to reallocate them 123// over and over again. 124var Float32ArrayCache = {}; 125 126// Takes a 2D array of commands and puts them into the WASM heap 127// as a 1D array. This allows them to referenced from the C++ code. 128// Returns a 2 element array, with the first item being essentially a 129// pointer to the array and the second item being the length of 130// the new 1D array. 131// 132// Example usage: 133// let cmds = [ 134// [CanvasKit.MOVE_VERB, 0, 10], 135// [CanvasKit.LINE_VERB, 30, 40], 136// [CanvasKit.QUAD_VERB, 20, 50, 45, 60], 137// ]; 138function loadCmdsTypedArray(arr) { 139 var len = 0; 140 for (var r = 0; r < arr.length; r++) { 141 len += arr[r].length; 142 } 143 144 var ta; 145 if (Float32ArrayCache[len]) { 146 ta = Float32ArrayCache[len]; 147 } else { 148 ta = new Float32Array(len); 149 Float32ArrayCache[len] = ta; 150 } 151 // Flatten into a 1d array 152 var i = 0; 153 for (var r = 0; r < arr.length; r++) { 154 for (var c = 0; c < arr[r].length; c++) { 155 var item = arr[r][c]; 156 ta[i] = item; 157 i++; 158 } 159 } 160 161 var ptr = copy1dArray(ta, CanvasKit.HEAPF32); 162 return [ptr, len]; 163} 164