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