411 lines
11 KiB
C++
411 lines
11 KiB
C++
/*
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Minetest-c55
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Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <math.h>
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#include "noise.h"
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#include <iostream>
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#include "debug.h"
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#define NOISE_MAGIC_X 1619
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#define NOISE_MAGIC_Y 31337
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#define NOISE_MAGIC_Z 52591
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#define NOISE_MAGIC_SEED 1013
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double cos_lookup[16] = {
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1.0,0.9238,0.7071,0.3826,0,-0.3826,-0.7071,-0.9238,
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1.0,-0.9238,-0.7071,-0.3826,0,0.3826,0.7071,0.9238
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};
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double dotProduct(double vx, double vy, double wx, double wy){
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return vx*wx+vy*wy;
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}
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double easeCurve(double t){
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return 6*pow(t,5)-15*pow(t,4)+10*pow(t,3);
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}
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double linearInterpolation(double x0, double x1, double t){
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return x0+(x1-x0)*t;
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}
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double biLinearInterpolation(double x0y0, double x1y0, double x0y1, double x1y1, double x, double y){
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double tx = easeCurve(x);
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double ty = easeCurve(y);
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/*double tx = x;
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double ty = y;*/
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double u = linearInterpolation(x0y0,x1y0,tx);
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double v = linearInterpolation(x0y1,x1y1,tx);
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return linearInterpolation(u,v,ty);
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}
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double triLinearInterpolation(
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double v000, double v100, double v010, double v110,
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double v001, double v101, double v011, double v111,
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double x, double y, double z)
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{
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/*double tx = easeCurve(x);
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double ty = easeCurve(y);
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double tz = easeCurve(z);*/
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double tx = x;
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double ty = y;
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double tz = z;
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return(
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v000*(1-tx)*(1-ty)*(1-tz) +
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v100*tx*(1-ty)*(1-tz) +
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v010*(1-tx)*ty*(1-tz) +
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v110*tx*ty*(1-tz) +
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v001*(1-tx)*(1-ty)*tz +
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v101*tx*(1-ty)*tz +
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v011*(1-tx)*ty*tz +
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v111*tx*ty*tz
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);
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}
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double noise2d(int x, int y, int seed)
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{
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int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y
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+ NOISE_MAGIC_SEED * seed) & 0x7fffffff;
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n = (n>>13)^n;
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n = (n * (n*n*60493+19990303) + 1376312589) & 0x7fffffff;
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return 1.0 - (double)n/1073741824;
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}
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double noise3d(int x, int y, int z, int seed)
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{
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int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y + NOISE_MAGIC_Z * z
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+ NOISE_MAGIC_SEED * seed) & 0x7fffffff;
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n = (n>>13)^n;
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n = (n * (n*n*60493+19990303) + 1376312589) & 0x7fffffff;
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return 1.0 - (double)n/1073741824;
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}
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#if 0
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double noise2d_gradient(double x, double y, int seed)
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{
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// Calculate the integer coordinates
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int x0 = (x > 0.0 ? (int)x : (int)x - 1);
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int y0 = (y > 0.0 ? (int)y : (int)y - 1);
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// Calculate the remaining part of the coordinates
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double xl = x - (double)x0;
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double yl = y - (double)y0;
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// Calculate random cosine lookup table indices for the integer corners.
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// They are looked up as unit vector gradients from the lookup table.
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int n00 = (int)((noise2d(x0, y0, seed)+1)*8);
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int n10 = (int)((noise2d(x0+1, y0, seed)+1)*8);
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int n01 = (int)((noise2d(x0, y0+1, seed)+1)*8);
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int n11 = (int)((noise2d(x0+1, y0+1, seed)+1)*8);
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// Make a dot product for the gradients and the positions, to get the values
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double s = dotProduct(cos_lookup[n00], cos_lookup[(n00+12)%16], xl, yl);
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double u = dotProduct(-cos_lookup[n10], cos_lookup[(n10+12)%16], 1.-xl, yl);
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double v = dotProduct(cos_lookup[n01], -cos_lookup[(n01+12)%16], xl, 1.-yl);
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double w = dotProduct(-cos_lookup[n11], -cos_lookup[(n11+12)%16], 1.-xl, 1.-yl);
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// Interpolate between the values
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return biLinearInterpolation(s,u,v,w,xl,yl);
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}
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#endif
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#if 1
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double noise2d_gradient(double x, double y, int seed)
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{
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// Calculate the integer coordinates
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int x0 = (x > 0.0 ? (int)x : (int)x - 1);
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int y0 = (y > 0.0 ? (int)y : (int)y - 1);
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// Calculate the remaining part of the coordinates
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double xl = x - (double)x0;
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double yl = y - (double)y0;
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// Get values for corners of cube
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double v00 = noise2d(x0, y0, seed);
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double v10 = noise2d(x0+1, y0, seed);
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double v01 = noise2d(x0, y0+1, seed);
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double v11 = noise2d(x0+1, y0+1, seed);
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// Interpolate
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return biLinearInterpolation(v00,v10,v01,v11,xl,yl);
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}
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#endif
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double noise3d_gradient(double x, double y, double z, int seed)
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{
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// Calculate the integer coordinates
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int x0 = (x > 0.0 ? (int)x : (int)x - 1);
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int y0 = (y > 0.0 ? (int)y : (int)y - 1);
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int z0 = (z > 0.0 ? (int)z : (int)z - 1);
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// Calculate the remaining part of the coordinates
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double xl = x - (double)x0;
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double yl = y - (double)y0;
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double zl = z - (double)z0;
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// Get values for corners of cube
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double v000 = noise3d(x0, y0, z0, seed);
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double v100 = noise3d(x0+1, y0, z0, seed);
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double v010 = noise3d(x0, y0+1, z0, seed);
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double v110 = noise3d(x0+1, y0+1, z0, seed);
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double v001 = noise3d(x0, y0, z0+1, seed);
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double v101 = noise3d(x0+1, y0, z0+1, seed);
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double v011 = noise3d(x0, y0+1, z0+1, seed);
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double v111 = noise3d(x0+1, y0+1, z0+1, seed);
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// Interpolate
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return triLinearInterpolation(v000,v100,v010,v110,v001,v101,v011,v111,xl,yl,zl);
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}
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double noise2d_perlin(double x, double y, int seed,
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int octaves, double persistence)
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{
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double a = 0;
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double f = 1.0;
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double g = 1.0;
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for(int i=0; i<octaves; i++)
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{
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a += g * noise2d_gradient(x*f, y*f, seed+i);
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f *= 2.0;
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g *= persistence;
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}
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return a;
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}
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double noise2d_perlin_abs(double x, double y, int seed,
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int octaves, double persistence)
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{
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double a = 0;
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double f = 1.0;
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double g = 1.0;
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for(int i=0; i<octaves; i++)
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{
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a += g * fabs(noise2d_gradient(x*f, y*f, seed+i));
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f *= 2.0;
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g *= persistence;
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}
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return a;
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}
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double noise3d_perlin(double x, double y, double z, int seed,
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int octaves, double persistence)
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{
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double a = 0;
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double f = 1.0;
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double g = 1.0;
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for(int i=0; i<octaves; i++)
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{
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a += g * noise3d_gradient(x*f, y*f, z*f, seed+i);
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f *= 2.0;
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g *= persistence;
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}
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return a;
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}
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double noise3d_perlin_abs(double x, double y, double z, int seed,
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int octaves, double persistence)
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{
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double a = 0;
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double f = 1.0;
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double g = 1.0;
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for(int i=0; i<octaves; i++)
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{
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a += g * fabs(noise3d_gradient(x*f, y*f, z*f, seed+i));
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f *= 2.0;
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g *= persistence;
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}
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return a;
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}
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// -1->0, 0->1, 1->0
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double contour(double v)
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{
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v = fabs(v);
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if(v >= 1.0)
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return 0.0;
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return (1.0-v);
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}
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double noise3d_param(const NoiseParams ¶m, double x, double y, double z)
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{
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double s = param.pos_scale;
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x /= s;
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y /= s;
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z /= s;
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if(param.type == NOISE_PERLIN)
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{
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return param.noise_scale*noise3d_perlin(x,y,z, param.seed,
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param.octaves,
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param.persistence);
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}
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else if(param.type == NOISE_PERLIN_ABS)
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{
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return param.noise_scale*noise3d_perlin_abs(x,y,z, param.seed,
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param.octaves,
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param.persistence);
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}
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else if(param.type == NOISE_PERLIN_CONTOUR)
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{
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return contour(param.noise_scale*noise3d_perlin(x,y,z,
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param.seed, param.octaves,
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param.persistence));
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}
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else if(param.type == NOISE_PERLIN_CONTOUR_FLIP_YZ)
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{
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return contour(param.noise_scale*noise3d_perlin(x,z,y,
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param.seed, param.octaves,
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param.persistence));
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}
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else assert(0);
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}
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/*
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NoiseBuffer
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*/
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NoiseBuffer::NoiseBuffer():
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m_data(NULL)
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{
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}
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NoiseBuffer::~NoiseBuffer()
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{
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clear();
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}
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void NoiseBuffer::clear()
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{
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if(m_data)
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delete[] m_data;
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m_data = NULL;
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m_size_x = 0;
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m_size_y = 0;
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m_size_z = 0;
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}
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void NoiseBuffer::create(const NoiseParams ¶m,
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double first_x, double first_y, double first_z,
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double last_x, double last_y, double last_z,
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double samplelength_x, double samplelength_y, double samplelength_z)
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{
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clear();
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m_start_x = first_x - samplelength_x;
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m_start_y = first_y - samplelength_y;
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m_start_z = first_z - samplelength_z;
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m_samplelength_x = samplelength_x;
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m_samplelength_y = samplelength_y;
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m_samplelength_z = samplelength_z;
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m_size_x = (last_x - m_start_x)/samplelength_x + 2;
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m_size_y = (last_y - m_start_y)/samplelength_y + 2;
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m_size_z = (last_z - m_start_z)/samplelength_z + 2;
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m_data = new double[m_size_x*m_size_y*m_size_z];
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for(int x=0; x<m_size_x; x++)
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for(int y=0; y<m_size_y; y++)
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for(int z=0; z<m_size_z; z++)
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{
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double xd = (m_start_x + (double)x*m_samplelength_x);
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double yd = (m_start_y + (double)y*m_samplelength_y);
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double zd = (m_start_z + (double)z*m_samplelength_z);
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double a = noise3d_param(param, xd,yd,zd);
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intSet(x,y,z, a);
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}
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}
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void NoiseBuffer::multiply(const NoiseParams ¶m)
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{
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assert(m_data != NULL);
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for(int x=0; x<m_size_x; x++)
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for(int y=0; y<m_size_y; y++)
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for(int z=0; z<m_size_z; z++)
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{
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double xd = (m_start_x + (double)x*m_samplelength_x);
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double yd = (m_start_y + (double)y*m_samplelength_y);
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double zd = (m_start_z + (double)z*m_samplelength_z);
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double a = noise3d_param(param, xd,yd,zd);
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intMultiply(x,y,z, a);
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}
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}
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// Deprecated
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void NoiseBuffer::create(int seed, int octaves, double persistence,
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bool abs,
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double first_x, double first_y, double first_z,
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double last_x, double last_y, double last_z,
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double samplelength_x, double samplelength_y, double samplelength_z)
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{
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NoiseParams param;
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param.type = abs ? NOISE_PERLIN_ABS : NOISE_PERLIN;
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param.seed = seed;
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param.octaves = octaves;
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param.persistence = persistence;
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create(param, first_x, first_y, first_z,
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last_x, last_y, last_z,
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samplelength_x, samplelength_y, samplelength_z);
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}
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void NoiseBuffer::intSet(int x, int y, int z, double d)
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{
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int i = m_size_x*m_size_y*z + m_size_x*y + x;
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assert(i >= 0);
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assert(i < m_size_x*m_size_y*m_size_z);
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m_data[i] = d;
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}
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void NoiseBuffer::intMultiply(int x, int y, int z, double d)
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{
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int i = m_size_x*m_size_y*z + m_size_x*y + x;
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assert(i >= 0);
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assert(i < m_size_x*m_size_y*m_size_z);
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m_data[i] = m_data[i] * d;
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}
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double NoiseBuffer::intGet(int x, int y, int z)
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{
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int i = m_size_x*m_size_y*z + m_size_x*y + x;
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assert(i >= 0);
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assert(i < m_size_x*m_size_y*m_size_z);
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return m_data[i];
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}
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double NoiseBuffer::get(double x, double y, double z)
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{
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x -= m_start_x;
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y -= m_start_y;
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z -= m_start_z;
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x /= m_samplelength_x;
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y /= m_samplelength_y;
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z /= m_samplelength_z;
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// Calculate the integer coordinates
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int x0 = (x > 0.0 ? (int)x : (int)x - 1);
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int y0 = (y > 0.0 ? (int)y : (int)y - 1);
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int z0 = (z > 0.0 ? (int)z : (int)z - 1);
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// Calculate the remaining part of the coordinates
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double xl = x - (double)x0;
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double yl = y - (double)y0;
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double zl = z - (double)z0;
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// Get values for corners of cube
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double v000 = intGet(x0, y0, z0);
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double v100 = intGet(x0+1, y0, z0);
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double v010 = intGet(x0, y0+1, z0);
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double v110 = intGet(x0+1, y0+1, z0);
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double v001 = intGet(x0, y0, z0+1);
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double v101 = intGet(x0+1, y0, z0+1);
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double v011 = intGet(x0, y0+1, z0+1);
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double v111 = intGet(x0+1, y0+1, z0+1);
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// Interpolate
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return triLinearInterpolation(v000,v100,v010,v110,v001,v101,v011,v111,xl,yl,zl);
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}
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