3 Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24 #define NOISE_MAGIC_X 1619
25 #define NOISE_MAGIC_Y 31337
26 #define NOISE_MAGIC_Z 52591
27 #define NOISE_MAGIC_SEED 1013
29 double cos_lookup[16] = {
30 1.0,0.9238,0.7071,0.3826,0,-0.3826,-0.7071,-0.9238,
31 1.0,-0.9238,-0.7071,-0.3826,0,0.3826,0.7071,0.9238
34 double dotProduct(double vx, double vy, double wx, double wy){
38 double easeCurve(double t){
39 return 6*pow(t,5)-15*pow(t,4)+10*pow(t,3);
42 double linearInterpolation(double x0, double x1, double t){
46 double biLinearInterpolation(double x0y0, double x1y0, double x0y1, double x1y1, double x, double y){
47 double tx = easeCurve(x);
48 double ty = easeCurve(y);
49 double u = linearInterpolation(x0y0,x1y0,tx);
50 double v = linearInterpolation(x0y1,x1y1,tx);
51 return linearInterpolation(u,v,ty);
54 double triLinearInterpolation(
55 double v000, double v100, double v010, double v110,
56 double v001, double v101, double v011, double v111,
57 double x, double y, double z)
59 /*double tx = easeCurve(x);
60 double ty = easeCurve(y);
61 double tz = easeCurve(z);*/
66 v000*(1-tx)*(1-ty)*(1-tz) +
67 v100*tx*(1-ty)*(1-tz) +
68 v010*(1-tx)*ty*(1-tz) +
70 v001*(1-tx)*(1-ty)*tz +
77 double noise2d(int x, int y, int seed)
79 int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y
80 + NOISE_MAGIC_SEED * seed) & 0x7fffffff;
82 n = (n * (n*n*60493+19990303) + 1376312589) & 0x7fffffff;
83 return 1.0 - (double)n/1073741824;
86 double noise3d(int x, int y, int z, int seed)
88 int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y + NOISE_MAGIC_Z * z
89 + NOISE_MAGIC_SEED * seed) & 0x7fffffff;
91 n = (n * (n*n*60493+19990303) + 1376312589) & 0x7fffffff;
92 return 1.0 - (double)n/1073741824;
95 double noise2d_gradient(double x, double y, int seed)
97 // Calculate the integer coordinates
98 int x0 = (x > 0.0 ? (int)x : (int)x - 1);
99 int y0 = (y > 0.0 ? (int)y : (int)y - 1);
100 // Calculate the remaining part of the coordinates
101 double xl = x - (double)x0;
102 double yl = y - (double)y0;
103 // Calculate random cosine lookup table indices for the integer corners.
104 // They are looked up as unit vector gradients from the lookup table.
105 int n00 = (int)((noise2d(x0, y0, seed)+1)*8);
106 int n10 = (int)((noise2d(x0+1, y0, seed)+1)*8);
107 int n01 = (int)((noise2d(x0, y0+1, seed)+1)*8);
108 int n11 = (int)((noise2d(x0+1, y0+1, seed)+1)*8);
109 // Make a dot product for the gradients and the positions, to get the values
110 double s = dotProduct(cos_lookup[n00], cos_lookup[(n00+12)%16], xl, yl);
111 double u = dotProduct(-cos_lookup[n10], cos_lookup[(n10+12)%16], 1.-xl, yl);
112 double v = dotProduct(cos_lookup[n01], -cos_lookup[(n01+12)%16], xl, 1.-yl);
113 double w = dotProduct(-cos_lookup[n11], -cos_lookup[(n11+12)%16], 1.-xl, 1.-yl);
114 // Interpolate between the values
115 return biLinearInterpolation(s,u,v,w,xl,yl);
118 double noise3d_gradient(double x, double y, double z, int seed)
120 // Calculate the integer coordinates
121 int x0 = (x > 0.0 ? (int)x : (int)x - 1);
122 int y0 = (y > 0.0 ? (int)y : (int)y - 1);
123 int z0 = (z > 0.0 ? (int)z : (int)z - 1);
124 // Calculate the remaining part of the coordinates
125 double xl = x - (double)x0;
126 double yl = y - (double)y0;
127 double zl = y - (double)z0;
128 // Get values for corners of cube
129 double v000 = noise3d(x0, y0, z0, seed);
130 double v100 = noise3d(x0+1, y0, z0, seed);
131 double v010 = noise3d(x0, y0+1, z0, seed);
132 double v110 = noise3d(x0+1, y0+1, z0, seed);
133 double v001 = noise3d(x0, y0, z0+1, seed);
134 double v101 = noise3d(x0+1, y0, z0+1, seed);
135 double v011 = noise3d(x0, y0+1, z0+1, seed);
136 double v111 = noise3d(x0+1, y0+1, z0+1, seed);
138 return triLinearInterpolation(v000,v100,v010,v110,v001,v101,v011,v111,xl,yl,zl);
141 double noise2d_perlin(double x, double y, int seed,
142 int octaves, double persistence)
147 for(int i=0; i<octaves; i++)
149 a += g * noise2d_gradient(x*f, y*f, seed+i);
156 double noise3d_perlin(double x, double y, double z, int seed,
157 int octaves, double persistence)
162 for(int i=0; i<octaves; i++)
164 a += g * noise3d_gradient(x*f, y*f, z*f, seed+i);