/*
* A speed-improved simplex noise algorithm for 2D, 3D and 4D in Java.
*
* Based on example code by Stefan Gustavson (stegu@itn.liu.se).
* Optimisations by Peter Eastman (peastman@drizzle.stanford.edu).
* Better rank ordering method by Stefan Gustavson in 2012.
*
* This could be speeded up even further, but it's useful as it is.
*
* Version 2012-03-09
*
* This code was placed in the public domain by its original author,
* Stefan Gustavson. You may use it as you see fit, but
* attribution is appreciated.
*
* Update by NightCabbage (2013-11-05) NightCabbage@gmail.com
*
* Working with Stefan (thanks!) I have compiled all of the
* improvements I could find and put them into this code.
*
* Note that for corner contribution I have made the decision here to
* use 0.6 instead of 0.5, as I believe it looks a bit better for 2d
* purposes (0.5 made it a bit more grey, and also had more pulsating for
* integral inputs). If you're using it for bumpmaps or similar, feel
* free to change it - and the final scale factor is 76 (as opposed to 32).
*/
using System;
namespace Noise
{
public class NoiseGen
{
public double XScale = 0.02;
public double YScale = 0.02;
public double ZScale = 1;
public byte Octaves = 1;
public double Scale
{
set
{
XScale = value;
YScale = value;
}
}
public NoiseGen()
{
}
public NoiseGen(double pScale, byte pOctaves)
{
XScale = pScale;
YScale = pScale;
Octaves = pOctaves;
}
public NoiseGen(double pXScale, double pYScale, byte pOctaves)
{
XScale = pXScale;
YScale = pYScale;
Octaves = pOctaves;
}
public float GetNoise(double x, double y, double z)
{
if(Octaves > 1)
return Noise.GetOctaveNoise(x * XScale, y * YScale, z * ZScale, Octaves);
else
return Noise.GetNoise(x * XScale, y * YScale, z * ZScale);
}
}
// Simplex noise in 3D
public static class Noise
{
// Inner class to speed up gradient computations
// (array access is a lot slower than member access)
private struct Grad
{
public double x, y, z, w;
public Grad(double x, double y, double z)
{
this.x = x;
this.y = y;
this.z = z;
this.w = 0;
}
}
private static Grad[] grad3 = new Grad[] {
new Grad(1,1,0), new Grad(-1,1,0), new Grad(1,-1,0), new Grad(-1,-1,0),
new Grad(1,0,1), new Grad(-1,0,1), new Grad(1,0,-1), new Grad(-1,0,-1),
new Grad(0,1,1), new Grad(0,-1,1), new Grad(0,1,-1), new Grad(0,-1,-1)
};
private static short[] p = new short[] {
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
};
// To remove the need for index wrapping, double the permutation table length
private static short[] perm = new short[512];
private static short[] permMod12 = new short[512];
static Noise()
{
for(int i = 0; i < 512; i++)
{
perm[i] = p[i & 255];
permMod12[i] = (short)(perm[i] % 12);
}
}
// Skewing and unskewing factors for 2, 3, and 4 dimensions
private static double F3 = 1.0 / 3.0;
private static double G3 = 1.0 / 6.0;
// This method is a *lot* faster than using (int)Math.floor(x)
private static int fastfloor(double x)
{
int xi = (int)x;
return x < xi ? xi - 1 : xi;
}
private static double dot(Grad g, double x, double y, double z)
{
return g.x * x + g.y * y + g.z * z;
}
// 3D simplex noise
public static float GetNoise(double xin, double yin, double zin)
{
double n0, n1, n2, n3; // Noise contributions from the four corners
// Skew the input space to determine which simplex cell we're in
double s = (xin+yin+zin)*F3; // Very nice and simple skew factor for 3D
int i = fastfloor(xin+s);
int j = fastfloor(yin+s);
int k = fastfloor(zin+s);
double t = (i+j+k)*G3;
double X0 = i-t; // Unskew the cell origin back to (x,y,z) space
double Y0 = j-t;
double Z0 = k-t;
double x0 = xin-X0; // The x,y,z distances from the cell origin
double y0 = yin-Y0;
double z0 = zin-Z0;
// For the 3D case, the simplex shape is a slightly irregular tetrahedron.
// Determine which simplex we are in.
int i1, j1, k1; // Offsets for second corner of simplex in (i,j,k) coords
int i2, j2, k2; // Offsets for third corner of simplex in (i,j,k) coords
if(x0>=y0) {
if(y0>=z0)
{ i1=1; j1=0; k1=0; i2=1; j2=1; k2=0; } // X Y Z order
else if(x0>=z0) { i1=1; j1=0; k1=0; i2=1; j2=0; k2=1; } // X Z Y order
else { i1=0; j1=0; k1=1; i2=1; j2=0; k2=1; } // Z X Y order
}
else { // x0