190 lines
7.1 KiB
JavaScript
190 lines
7.1 KiB
JavaScript
// http://mrl.nyu.edu/~perlin/noise/
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const ImprovedNoise = function () {
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const p = [151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225, 140, 36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10,
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23, 190, 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 11, 32, 57, 177, 33, 88, 237, 149, 56, 87,
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174, 20, 125, 136, 171, 168, 68, 175, 74, 165, 71, 134, 139, 48, 27, 166, 77, 146, 158, 231, 83, 111, 229, 122, 60, 211,
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133, 230, 220, 105, 92, 41, 55, 46, 245, 40, 244, 102, 143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208,
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89, 18, 169, 200, 196, 135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 226, 250, 124, 123, 5,
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202, 38, 147, 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42, 223, 183, 170, 213, 119,
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248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9, 129, 22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232,
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178, 185, 112, 104, 218, 246, 97, 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81, 51, 145, 235, 249,
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14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157, 184, 84, 204, 176, 115, 121, 50, 45, 127, 4, 150, 254, 138, 236, 205,
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93, 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156, 180];
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for (let i = 0; i < 256; i++) {
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p[256 + i] = p[i];
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}
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function fade(t) {
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return t * t * t * (t * (t * 6 - 15) + 10);
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}
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function lerp(t, a, b) {
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return a + t * (b - a);
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}
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function grad(hash, x, y, z) {
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const h = hash & 15;
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const u = h < 8 ? x : y; const
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v = h < 4 ? y : h == 12 || h == 14 ? x : z;
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return ((h & 1) == 0 ? u : -u) + ((h & 2) == 0 ? v : -v);
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}
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return {
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noise(x, y, z) {
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const floorX = Math.floor(x); const floorY = Math.floor(y); const
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floorZ = Math.floor(z);
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const X = floorX & 255; const Y = floorY & 255; const
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Z = floorZ & 255;
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x -= floorX;
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y -= floorY;
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z -= floorZ;
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const xMinus1 = x - 1; const yMinus1 = y - 1; const
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zMinus1 = z - 1;
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const u = fade(x); const v = fade(y); const
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w = fade(z);
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const A = p[X] + Y; const AA = p[A] + Z; const AB = p[A + 1] + Z; const B = p[X + 1] + Y; const BA = p[B] + Z; const
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BB = p[B + 1] + Z;
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return lerp(w, lerp(v, lerp(u, grad(p[AA], x, y, z),
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grad(p[BA], xMinus1, y, z)),
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lerp(u, grad(p[AB], x, yMinus1, z),
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grad(p[BB], xMinus1, yMinus1, z))),
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lerp(v, lerp(u, grad(p[AA + 1], x, y, zMinus1),
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grad(p[BA + 1], xMinus1, y, z - 1)),
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lerp(u, grad(p[AB + 1], x, yMinus1, zMinus1),
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grad(p[BB + 1], xMinus1, yMinus1, zMinus1))));
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},
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};
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};
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const currentRandom = Math.random;
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// Pseudo-random generator
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function Marsaglia(i1, i2) {
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// from http://www.math.uni-bielefeld.de/~sillke/ALGORITHMS/random/marsaglia-c
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let z = i1 || 362436069; let
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w = i2 || 521288629;
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const nextInt = function () {
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z = (36969 * (z & 65535) + (z >>> 16)) & 0xFFFFFFFF;
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w = (18000 * (w & 65535) + (w >>> 16)) & 0xFFFFFFFF;
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return (((z & 0xFFFF) << 16) | (w & 0xFFFF)) & 0xFFFFFFFF;
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};
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this.nextDouble = function () {
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const i = nextInt() / 4294967296;
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return i < 0 ? 1 + i : i;
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};
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this.nextInt = nextInt;
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}
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Marsaglia.createRandomized = function () {
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const now = new Date();
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return new Marsaglia((now / 60000) & 0xFFFFFFFF, now & 0xFFFFFFFF);
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};
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// Noise functions and helpers
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function PerlinNoise(seed) {
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const rnd = seed !== undefined ? new Marsaglia(seed) : Marsaglia.createRandomized();
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let i; let
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j;
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// http://www.noisemachine.com/talk1/17b.html
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// http://mrl.nyu.edu/~perlin/noise/
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// generate permutation
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const p = new Array(512);
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for (i = 0; i < 256; ++i) { p[i] = i; }
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for (i = 0; i < 256; ++i) { const t = p[j = rnd.nextInt() & 0xFF]; p[j] = p[i]; p[i] = t; }
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// copy to avoid taking mod in p[0];
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for (i = 0; i < 256; ++i) { p[i + 256] = p[i]; }
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function grad3d(i, x, y, z) {
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const h = i & 15; // convert into 12 gradient directions
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const u = h < 8 ? x : y;
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const v = h < 4 ? y : h === 12 || h === 14 ? x : z;
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return ((h & 1) === 0 ? u : -u) + ((h & 2) === 0 ? v : -v);
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}
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function grad2d(i, x, y) {
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const v = (i & 1) === 0 ? x : y;
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return (i & 2) === 0 ? -v : v;
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}
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function grad1d(i, x) {
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return (i & 1) === 0 ? -x : x;
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}
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function lerp(t, a, b) { return a + t * (b - a); }
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this.noise3d = function (x, y, z) {
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const X = Math.floor(x) & 255; const Y = Math.floor(y) & 255; const
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Z = Math.floor(z) & 255;
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x -= Math.floor(x); y -= Math.floor(y); z -= Math.floor(z);
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const fx = (3 - 2 * x) * x * x; const fy = (3 - 2 * y) * y * y; const
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fz = (3 - 2 * z) * z * z;
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const p0 = p[X] + Y; const p00 = p[p0] + Z; const p01 = p[p0 + 1] + Z; const p1 = p[X + 1] + Y; const p10 = p[p1] + Z; const
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p11 = p[p1 + 1] + Z;
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return lerp(fz,
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lerp(fy, lerp(fx, grad3d(p[p00], x, y, z), grad3d(p[p10], x - 1, y, z)),
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lerp(fx, grad3d(p[p01], x, y - 1, z), grad3d(p[p11], x - 1, y - 1, z))),
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lerp(fy, lerp(fx, grad3d(p[p00 + 1], x, y, z - 1), grad3d(p[p10 + 1], x - 1, y, z - 1)),
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lerp(fx, grad3d(p[p01 + 1], x, y - 1, z - 1), grad3d(p[p11 + 1], x - 1, y - 1, z - 1))));
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};
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this.noise2d = function (x, y) {
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const X = Math.floor(x) & 255; const
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Y = Math.floor(y) & 255;
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x -= Math.floor(x); y -= Math.floor(y);
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const fx = (3 - 2 * x) * x * x; const
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fy = (3 - 2 * y) * y * y;
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const p0 = p[X] + Y; const
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p1 = p[X + 1] + Y;
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return lerp(fy,
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lerp(fx, grad2d(p[p0], x, y), grad2d(p[p1], x - 1, y)),
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lerp(fx, grad2d(p[p0 + 1], x, y - 1), grad2d(p[p1 + 1], x - 1, y - 1)));
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};
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this.noise1d = function (x) {
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const X = Math.floor(x) & 255;
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x -= Math.floor(x);
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const fx = (3 - 2 * x) * x * x;
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return lerp(fx, grad1d(p[X], x), grad1d(p[X + 1], x - 1));
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};
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}
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// these are lifted from Processing.js
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// processing defaults
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const noiseProfile = {
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generator: undefined, octaves: 4, fallout: 0.5, seed: undefined,
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};
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module.exports = function noise(x, y, z) {
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if (noiseProfile.generator === undefined) {
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// caching
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noiseProfile.generator = new PerlinNoise(noiseProfile.seed);
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}
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const generator = noiseProfile.generator;
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let effect = 1; let k = 1; let
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sum = 0;
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for (let i = 0; i < noiseProfile.octaves; ++i) {
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effect *= noiseProfile.fallout;
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switch (arguments.length) {
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case 1:
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sum += effect * (1 + generator.noise1d(k * x)) / 2; break;
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case 2:
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sum += effect * (1 + generator.noise2d(k * x, k * y)) / 2; break;
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case 3:
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sum += effect * (1 + generator.noise3d(k * x, k * y, k * z)) / 2; break;
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}
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k *= 2;
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}
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return sum;
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};
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