package org.pushingpixels.substance.internal.utils;
/**
* A class for producing Perlin-inspired noise. The code written by Ken Perlin.
*
* @author Ken Perlin http://mrl.nyu.edu/~perlin/
*/
public class PerlinNoiseGenerator {
/**
* Returns noise for the specified coordinates.
*
* @param x
* X coordinate.
* @param y
* Y coordinate.
* @param z
* Z coordinate.
* @return Noise for the specified coordinates.
*/
static public double noise(double x, double y, double z) {
int X = (int) Math.floor(x) & 255, // FIND UNIT CUBE THAT
Y = (int) Math.floor(y) & 255, // CONTAINS POINT.
Z = (int) Math.floor(z) & 255;
x -= Math.floor(x); // FIND RELATIVE X,Y,Z
y -= Math.floor(y); // OF POINT IN CUBE.
z -= Math.floor(z);
double u = fade(x), // COMPUTE FADE CURVES
v = fade(y), // FOR EACH OF X,Y,Z.
w = fade(z);
int A = p[X] + Y, AA = p[A] + Z, AB = p[A + 1] + Z, // HASH COORDINATES
// OF
B = p[X + 1] + Y, BA = p[B] + Z, BB = p[B + 1] + Z; // THE 8 CUBE
// CORNERS,
return lerp(w, lerp(v, lerp(u, grad(p[AA], x, y, z), // AND ADD
grad(p[BA], x - 1, y, z)), // BLENDED
lerp(u, grad(p[AB], x, y - 1, z), // RESULTS
grad(p[BB], x - 1, y - 1, z))),// FROM 8
lerp(v, lerp(u, grad(p[AA + 1], x, y, z - 1), // CORNERS
grad(p[BA + 1], x - 1, y, z - 1)), // OF CUBE
lerp(u, grad(p[AB + 1], x, y - 1, z - 1), grad(
p[BB + 1], x - 1, y - 1, z - 1))));
}
/**
* Fades the specified value.
*
* @param t
* Value to fade.
* @return faded value.
*/
static double fade(double t) {
return t * t * t * (t * (t * 6 - 15) + 10);
}
/**
* Interpolates the specified value.
*
* @param t
* Value.
* @param a
* Starting interpolation value.
* @param b
* Ending interpolation value.
* @return Interpolated value.
*/
static double lerp(double t, double a, double b) {
return a + t * (b - a);
}
/**
* @param hash
* @param x
* @param y
* @param z
* @return
*/
static double grad(int hash, double x, double y, double z) {
int h = hash & 15; // CONVERT LO 4 BITS OF HASH CODE
double u = h < 8 ? x : y, // INTO 12 GRADIENT DIRECTIONS.
v = h < 4 ? y : (h == 12) || (h == 14) ? x : z;
return ((h & 1) == 0 ? u : -u) + ((h & 2) == 0 ? v : -v);
}
/**
* Permutations.
*/
static final int p[] = new int[512];
/**
* Permutations.
*/
static final int permutation[] = { 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, 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, 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, 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, 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,
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, 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, 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, 195, 78, 66, 215, 61, 156, 180 };
static {
for (int i = 0; i < 256; i++)
p[256 + i] = p[i] = permutation[i];
}
}