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| 1 | +// JAVA REFERENCE IMPLEMENTATION OF IMPROVED NOISE - COPYRIGHT 2002 KEN PERLIN. |
| 2 | + |
| 3 | +public final class PerlinNoise { |
| 4 | + static public double noise(double x, double y, double z) { |
| 5 | + int X = (int)Math.floor(x) & 255, // FIND UNIT CUBE THAT |
| 6 | + Y = (int)Math.floor(y) & 255, // CONTAINS POINT. |
| 7 | + Z = (int)Math.floor(z) & 255; |
| 8 | + x -= Math.floor(x); // FIND RELATIVE X,Y,Z |
| 9 | + y -= Math.floor(y); // OF POINT IN CUBE. |
| 10 | + z -= Math.floor(z); |
| 11 | + double u = fade(x), // COMPUTE FADE CURVES |
| 12 | + v = fade(y), // FOR EACH OF X,Y,Z. |
| 13 | + w = fade(z); |
| 14 | + int A = p[X ]+Y, AA = p[A]+Z, AB = p[A+1]+Z, // HASH COORDINATES OF |
| 15 | + B = p[X+1]+Y, BA = p[B]+Z, BB = p[B+1]+Z; // THE 8 CUBE CORNERS, |
| 16 | + |
| 17 | + return lerp(w, lerp(v, lerp(u, grad(p[AA ], x , y , z ), // AND ADD |
| 18 | + grad(p[BA ], x-1, y , z )), // BLENDED |
| 19 | + lerp(u, grad(p[AB ], x , y-1, z ), // RESULTS |
| 20 | + grad(p[BB ], x-1, y-1, z ))),// FROM 8 |
| 21 | + lerp(v, lerp(u, grad(p[AA+1], x , y , z-1 ), // CORNERS |
| 22 | + grad(p[BA+1], x-1, y , z-1 )), // OF CUBE |
| 23 | + lerp(u, grad(p[AB+1], x , y-1, z-1 ), |
| 24 | + grad(p[BB+1], x-1, y-1, z-1 )))); |
| 25 | + } |
| 26 | + static double fade(double t) { return t * t * t * (t * (t * 6 - 15) + 10); } |
| 27 | + static double lerp(double t, double a, double b) { return a + t * (b - a); } |
| 28 | + static double grad(int hash, double x, double y, double z) { |
| 29 | + int h = hash & 15; // CONVERT LO 4 BITS OF HASH CODE |
| 30 | + double u = h<8 ? x : y, // INTO 12 GRADIENT DIRECTIONS. |
| 31 | + v = h<4 ? y : h==12||h==14 ? x : z; |
| 32 | + return ((h&1) == 0 ? u : -u) + ((h&2) == 0 ? v : -v); |
| 33 | + } |
| 34 | + static final int p[] = new int[512], permutation[] = { 151,160,137,91,90,15, |
| 35 | + 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, |
| 36 | + 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, |
| 37 | + 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, |
| 38 | + 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, |
| 39 | + 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, |
| 40 | + 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, |
| 41 | + 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, |
| 42 | + 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, |
| 43 | + 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, |
| 44 | + 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, |
| 45 | + 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, |
| 46 | + 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180 |
| 47 | + }; |
| 48 | + static { for (int i=0; i < 256 ; i++) p[256+i] = p[i] = permutation[i]; } |
| 49 | +} |
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