172 lines
6.9 KiB
C
172 lines
6.9 KiB
C
|
/* Copyright (c) 2007-2012 Eliot Eshelman
|
||
|
|
*
|
||
|
|
* 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 3 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, see <http://www.gnu.org/licenses/>.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
|
||
|
|
#ifndef SIMPLEX_H_
|
||
|
|
#define SIMPLEX_H_
|
||
|
|
|
||
|
|
#include <stdint.h>
|
||
|
|
|
||
|
|
/* 2D, 3D and 4D Simplex Noise functions return 'random' values in (-1, 1).
|
||
|
|
|
||
|
|
This algorithm was originally designed by Ken Perlin, but my code has been
|
||
|
|
adapted from the implementation written by Stefan Gustavson (stegu@itn.liu.se)
|
||
|
|
|
||
|
|
Raw Simplex noise functions return the value generated by Ken's algorithm.
|
||
|
|
|
||
|
|
Scaled Raw Simplex noise functions adjust the range of values returned from the
|
||
|
|
traditional (-1, 1) to whichever bounds are passed to the function.
|
||
|
|
|
||
|
|
Multi-Octave Simplex noise functions compine multiple noise values to create a
|
||
|
|
more complex result. Each successive layer of noise is adjusted and scaled.
|
||
|
|
|
||
|
|
Scaled Multi-Octave Simplex noise functions scale the values returned from the
|
||
|
|
traditional (-1,1) range to whichever range is passed to the function.
|
||
|
|
|
||
|
|
In many cases, you may think you only need a 1D noise function, but in practice
|
||
|
|
2D is almost always better. For instance, if you're using the current frame
|
||
|
|
number as the parameter for the noise, all objects will end up with the same
|
||
|
|
noise value at each frame. By adding a second parameter on the second
|
||
|
|
dimension, you can ensure that each gets a unique noise value and they don't
|
||
|
|
all look identical.
|
||
|
|
*/
|
||
|
|
|
||
|
|
//from http://www.6by9.net/simplex-noise-for-c-and-python/
|
||
|
|
|
||
|
|
// Multi-octave Simplex noise
|
||
|
|
// For each octave, a higher frequency/lower amplitude function will be added to the original.
|
||
|
|
// The higher the persistence [0-1], the more of each succeeding octave will be added.
|
||
|
|
float octave_noise_2d(const float octaves,
|
||
|
|
const float persistence,
|
||
|
|
const float scale,
|
||
|
|
const float x,
|
||
|
|
const float y);
|
||
|
|
float octave_noise_3d(const float octaves,
|
||
|
|
const float persistence,
|
||
|
|
const float scale,
|
||
|
|
const float x,
|
||
|
|
const float y,
|
||
|
|
const float z);
|
||
|
|
float octave_noise_4d(const float octaves,
|
||
|
|
const float persistence,
|
||
|
|
const float scale,
|
||
|
|
const float x,
|
||
|
|
const float y,
|
||
|
|
const float z,
|
||
|
|
const float w);
|
||
|
|
|
||
|
|
|
||
|
|
// Scaled Multi-octave Simplex noise
|
||
|
|
// The result will be between the two parameters passed.
|
||
|
|
float scaled_octave_noise_2d( const float octaves,
|
||
|
|
const float persistence,
|
||
|
|
const float scale,
|
||
|
|
const float loBound,
|
||
|
|
const float hiBound,
|
||
|
|
const float x,
|
||
|
|
const float y);
|
||
|
|
float scaled_octave_noise_3d( const float octaves,
|
||
|
|
const float persistence,
|
||
|
|
const float scale,
|
||
|
|
const float loBound,
|
||
|
|
const float hiBound,
|
||
|
|
const float x,
|
||
|
|
const float y,
|
||
|
|
const float z);
|
||
|
|
float scaled_octave_noise_4d( const float octaves,
|
||
|
|
const float persistence,
|
||
|
|
const float scale,
|
||
|
|
const float loBound,
|
||
|
|
const float hiBound,
|
||
|
|
const float x,
|
||
|
|
const float y,
|
||
|
|
const float z,
|
||
|
|
const float w);
|
||
|
|
|
||
|
|
// Scaled Raw Simplex noise
|
||
|
|
// The result will be between the two parameters passed.
|
||
|
|
float scaled_raw_noise_2d( const float loBound,
|
||
|
|
const float hiBound,
|
||
|
|
const float x,
|
||
|
|
const float y);
|
||
|
|
float scaled_raw_noise_3d( const float loBound,
|
||
|
|
const float hiBound,
|
||
|
|
const float x,
|
||
|
|
const float y,
|
||
|
|
const float z);
|
||
|
|
float scaled_raw_noise_4d( const float loBound,
|
||
|
|
const float hiBound,
|
||
|
|
const float x,
|
||
|
|
const float y,
|
||
|
|
const float z,
|
||
|
|
const float w);
|
||
|
|
|
||
|
|
|
||
|
|
// Raw Simplex noise - a single noise value.
|
||
|
|
float raw_noise_2d(const float x, const float y);
|
||
|
|
float raw_noise_3d(const float x, const float y, const float z);
|
||
|
|
float raw_noise_4d(const float x, const float y, const float, const float w);
|
||
|
|
|
||
|
|
|
||
|
|
int fastfloor(const float x);
|
||
|
|
|
||
|
|
float dot(const int8_t* g, const float x, const float y);
|
||
|
|
float dot(const int8_t* g, const float x, const float y, const float z);
|
||
|
|
float dot(const int8_t* g, const float x, const float y, const float z, const float w);
|
||
|
|
|
||
|
|
|
||
|
|
// The gradients are the midpoints of the vertices of a cube.
|
||
|
|
static const int8_t grad3[12][3] = {
|
||
|
|
{1,1,0}, {-1,1,0}, {1,-1,0}, {-1,-1,0},
|
||
|
|
{1,0,1}, {-1,0,1}, {1,0,-1}, {-1,0,-1},
|
||
|
|
{0,1,1}, {0,-1,1}, {0,1,-1}, {0,-1,-1}
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
// The gradients are the midpoints of the vertices of a hypercube.
|
||
|
|
static const int8_t grad4[32][4]= {
|
||
|
|
{0,1,1,1}, {0,1,1,-1}, {0,1,-1,1}, {0,1,-1,-1},
|
||
|
|
{0,-1,1,1}, {0,-1,1,-1}, {0,-1,-1,1}, {0,-1,-1,-1},
|
||
|
|
{1,0,1,1}, {1,0,1,-1}, {1,0,-1,1}, {1,0,-1,-1},
|
||
|
|
{-1,0,1,1}, {-1,0,1,-1}, {-1,0,-1,1}, {-1,0,-1,-1},
|
||
|
|
{1,1,0,1}, {1,1,0,-1}, {1,-1,0,1}, {1,-1,0,-1},
|
||
|
|
{-1,1,0,1}, {-1,1,0,-1}, {-1,-1,0,1}, {-1,-1,0,-1},
|
||
|
|
{1,1,1,0}, {1,1,-1,0}, {1,-1,1,0}, {1,-1,-1,0},
|
||
|
|
{-1,1,1,0}, {-1,1,-1,0}, {-1,-1,1,0}, {-1,-1,-1,0}
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
// Permutation table. The same list is repeated twice.
|
||
|
|
// removed const
|
||
|
|
extern uint8_t perm[512];
|
||
|
|
|
||
|
|
|
||
|
|
// A lookup table to traverse the simplex around a given point in 4D.
|
||
|
|
static const uint8_t simplex[64][4] = {
|
||
|
|
{0,1,2,3},{0,1,3,2},{0,0,0,0},{0,2,3,1},{0,0,0,0},{0,0,0,0},{0,0,0,0},{1,2,3,0},
|
||
|
|
{0,2,1,3},{0,0,0,0},{0,3,1,2},{0,3,2,1},{0,0,0,0},{0,0,0,0},{0,0,0,0},{1,3,2,0},
|
||
|
|
{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},
|
||
|
|
{1,2,0,3},{0,0,0,0},{1,3,0,2},{0,0,0,0},{0,0,0,0},{0,0,0,0},{2,3,0,1},{2,3,1,0},
|
||
|
|
{1,0,2,3},{1,0,3,2},{0,0,0,0},{0,0,0,0},{0,0,0,0},{2,0,3,1},{0,0,0,0},{2,1,3,0},
|
||
|
|
{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},
|
||
|
|
{2,0,1,3},{0,0,0,0},{0,0,0,0},{0,0,0,0},{3,0,1,2},{3,0,2,1},{0,0,0,0},{3,1,2,0},
|
||
|
|
{2,1,0,3},{0,0,0,0},{0,0,0,0},{0,0,0,0},{3,1,0,2},{0,0,0,0},{3,2,0,1},{3,2,1,0}
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
#endif /*SIMPLEX_H_*/
|