mirror of
https://github.com/librempeg/librempeg
synced 2024-11-22 09:02:20 +00:00
102 lines
3.1 KiB
C
102 lines
3.1 KiB
C
/*
|
|
* Perlin noise generator
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg 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
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* Perlin Noise generator
|
|
*/
|
|
|
|
#ifndef AVFILTER_PERLIN_H
|
|
#define AVFILTER_PERLIN_H
|
|
|
|
#include <stdint.h>
|
|
|
|
enum FFPerlinRandomMode {
|
|
FF_PERLIN_RANDOM_MODE_RANDOM,
|
|
FF_PERLIN_RANDOM_MODE_KEN,
|
|
FF_PERLIN_RANDOM_MODE_SEED,
|
|
FF_PERLIN_RANDOM_MODE_NB
|
|
};
|
|
|
|
/**
|
|
* Perlin generator context. This needs to be initialized with the
|
|
* parameters used to generate the Perlin noise.
|
|
*/
|
|
typedef struct FFPerlin {
|
|
/**
|
|
* spatial repeat period, if negative it is ignored
|
|
*/
|
|
double period;
|
|
|
|
/**
|
|
* total number of components making up the noise, each one with
|
|
* doubled frequency
|
|
*/
|
|
int octaves;
|
|
|
|
/**
|
|
* ratio used to compute the amplitude of the next octave
|
|
* component with respect to the previous component
|
|
*/
|
|
double persistence;
|
|
|
|
/**
|
|
* permutations array used to compute the Perlin noise hash
|
|
*/
|
|
uint8_t permutations[512];
|
|
|
|
/**
|
|
* define how to compute the permutations array
|
|
*/
|
|
enum FFPerlinRandomMode random_mode;
|
|
|
|
/**
|
|
* when random_mode is set FF_PERLIN_RANDOM_MODE_RANDOM, set random
|
|
* seed used to compute the permutations array
|
|
*/
|
|
unsigned int random_seed;
|
|
} FFPerlin;
|
|
|
|
/**
|
|
* Initialize the Perlin noise generator with parameters.
|
|
*
|
|
* @param perlin Perlin noise generator context
|
|
* @param period spatial repeat period, if negative it is ignored
|
|
* @param octaves total number of components making up the noise, each one with doubled frequency
|
|
* @param persistence define ratio used to compute the amplitude of the next octave
|
|
* component with respect to the previous component
|
|
* @param random_mode define how to compute the permutations array
|
|
* @param random_seed when random_mode is set to FF_PERLIN_RANDOM_MODE_RANDOM, set random
|
|
* seed used to compute the permutations array
|
|
* @return a negative AVERROR code in case of error, a non negative value otherwise
|
|
*/
|
|
int ff_perlin_init(FFPerlin *perlin, double period, int octaves, double persistence,
|
|
enum FFPerlinRandomMode random_mode, unsigned int random_seed);
|
|
|
|
/**
|
|
* Compute Perlin noise given the x, y, z coordinates.
|
|
*
|
|
* @param perlin Perlin noise generator context
|
|
* @return normalized value for the perlin noise, in the range [0, 1]
|
|
*/
|
|
double ff_perlin_get(FFPerlin *perlin, double x, double y, double z);
|
|
|
|
#endif /* AVFILTER_PERLIN_H */
|