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PerlinNoise.cc
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PerlinNoise.cc
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#include "PerlinNoise.h"
#include "Math.h"
#include "Point.h"
// JAVA REFERENCE IMPLEMENTATION OF IMPROVED NOISE - COPYRIGHT 2002 KEN PERLIN.
// Derived from reference implementation - Steve Parker 2005
static int permute[] = { 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,
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 inline double fade(double t)
{
return t * t * t * (t * (t * 6 - 15) + 10);
}
static inline double lerp(double t, double a, double b)
{
return a + t * (b - a);
}
static inline 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);
}
double perlinNoise(const Point& p) {
// Compute lattice coordinates
int X = Floor(p.x());
int Y = Floor(p.y());
int Z = Floor(p.z());
// Find location of x,y,z in cell
double x = p.x()-X;
double y = p.y()-Y;
double z = p.z()-Z;
// Find unit cube that contains point
X &= 255;
Y &= 255;
Z &= 255;
// Compute fade curves for each of x,y,z
double u = fade(x);
double v = fade(y);
double w = fade(z);
// Hash coordinates of the 8 cube corners
int A = permute[X ]+Y, AA = permute[A]+Z, AB = permute[A+1]+Z,
B = permute[X+1]+Y, BA = permute[B]+Z, BB = permute[B+1]+Z;
// And add blended results from 8 corners of cube
return lerp(w, lerp(v, lerp(u, grad(permute[AA ], x , y , z ),
grad(permute[BA ], x-1, y , z )),
lerp(u, grad(permute[AB ], x , y-1, z ),
grad(permute[BB ], x-1, y-1, z ))),
lerp(v, lerp(u, grad(permute[AA+1], x , y , z-1 ),
grad(permute[BA+1], x-1, y , z-1 )),
lerp(u, grad(permute[AB+1], x , y-1, z-1 ),
grad(permute[BB+1], x-1, y-1, z-1 ))));
}
double turbulence(int octaves, const Point& p, double lacunarity, double gain)
{
double sum = 0;
double scale = 1;
double totalgain = 1;
for(int i=0;i<octaves;i++){
sum += totalgain*perlinNoise(Point(p.x()*scale, p.y()*scale, p.z()*scale));
scale *= lacunarity;
totalgain *= gain;
}
return sum;
}
double turbulenceAbs(int octaves, const Point& p, double lacunarity, double gain)
{
double sum = 0;
double scale = 1;
double totalgain = 1;
for(int i=0;i<octaves;i++){
sum += totalgain*Abs(perlinNoise(Point(p.x()*scale, p.y()*scale, p.z()*scale)));
scale *= lacunarity;
totalgain *= gain;
}
return sum;
}