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87 lines
3.9 KiB
JavaScript
87 lines
3.9 KiB
JavaScript
export const Noise = (function() {
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var p = [151,160,137,91,90,15,131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
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190,6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,88,237,149,56,87,174,20,125,136,171,168,
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68,175,74,165,71,134,139,48,27,166,77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
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102,143,54,65,25,63,161,1,216,80,73,209,76,132,187,208,89,18,169,200,196,135,130,116,188,159,86,164,100,109,198,173,
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186,3,64,52,217,226,250,124,123,5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
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223,183,170,213,119,248,152,2,44,154,163,70,221,153,101,155,167,43,172,9,129,22,39,253,19,98,108,110,79,113,224,232,
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178,185,112,104,218,246,97,228,251,34,242,193,238,210,144,12,191,179,162,241,81,51,145,235,249,14,239,107,49,192,
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214,31,181,199,106,157,184,84,204,176,115,121,50,45,127,4,150,254,138,236,205,93,222,114,67,29,24,72,243,141,128,
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195,78,66,215,61,156,180];
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for (var i=0; i < 256 ; i++) p[256+i] = p[i];
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function fade(t) { return t * t * t * (t * (t * 6 - 15) + 10); }
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function lerp(t, a, b) { return a + t * (b - a); }
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function grad(hash, x, y, z) {
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var h = hash & 15;
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var u = h<8 ? x : y, 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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perlin2: function(x, y) {
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var X = Math.floor(x) & 255, Y = Math.floor(y) & 255;
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x -= Math.floor(x); y -= Math.floor(y);
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var u = fade(x), v = fade(y);
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var A = p[X]+Y, AA = p[A], AB = p[A+1], B = p[X+1]+Y, BA = p[B], BB = p[B+1];
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return lerp(v, lerp(u, grad(p[AA], x, y, 0), grad(p[BA], x-1, y, 0)),
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lerp(u, grad(p[AB], x, y-1, 0), grad(p[BB], x-1, y-1, 0)));
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}
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};
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})();
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export const SimplexNoise = (function() {
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function SimplexNoise(random) {
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if (!random) random = Math.random;
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this.p = new Uint8Array(256);
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this.perm = new Uint8Array(512);
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this.permMod12 = new Uint8Array(512);
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for (var i = 0; i < 256; i++) {
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this.p[i] = Math.floor(random() * 256);
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}
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for (i = 0; i < 512; i++) {
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this.perm[i] = this.p[i & 255];
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this.permMod12[i] = this.perm[i] % 12;
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}
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}
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SimplexNoise.prototype.dot = function(g, x, y) {
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return g[0] * x + g[1] * y;
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};
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SimplexNoise.prototype.noise2D = function(xin, yin) {
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var grad3 = [[1, 1], [-1, 1], [1, -1], [-1, -1],
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[1, 0], [-1, 0], [1, 0], [-1, 0],
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[0, 1], [0, -1], [0, 1], [0, -1]];
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var n0, n1, n2;
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var F2 = 0.5 * (Math.sqrt(3.0) - 1.0);
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var G2 = (3.0 - Math.sqrt(3.0)) / 6.0;
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var s = (xin + yin) * F2;
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var i = Math.floor(xin + s);
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var j = Math.floor(yin + s);
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var t = (i + j) * G2;
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var X0 = i - t;
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var Y0 = j - t;
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var x0 = xin - X0;
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var y0 = yin - Y0;
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var i1, j1;
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if (x0 > y0) { i1 = 1; j1 = 0; } else { i1 = 0; j1 = 1; }
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var x1 = x0 - i1 + G2;
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var y1 = y0 - j1 + G2;
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var x2 = x0 - 1.0 + 2.0 * G2;
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var y2 = y0 - 1.0 + 2.0 * G2;
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var ii = i & 255;
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var jj = j & 255;
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var gi0 = this.permMod12[ii + this.perm[jj]];
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var gi1 = this.permMod12[ii + i1 + this.perm[jj + j1]];
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var gi2 = this.permMod12[ii + 1 + this.perm[jj + 1]];
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var t0 = 0.5 - x0 * x0 - y0 * y0;
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if (t0 < 0) n0 = 0.0;
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else { t0 *= t0; n0 = t0 * t0 * this.dot(grad3[gi0], x0, y0); }
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var t1 = 0.5 - x1 * x1 - y1 * y1;
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if (t1 < 0) n1 = 0.0;
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else { t1 *= t1; n1 = t1 * t1 * this.dot(grad3[gi1], x1, y1); }
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var t2 = 0.5 - x2 * x2 - y2 * y2;
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if (t2 < 0) n2 = 0.0;
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else { t2 *= t2; n2 = t2 * t2 * this.dot(grad3[gi2], x2, y2); }
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return 70.0 * (n0 + n1 + n2);
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};
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return SimplexNoise;
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})();
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