libcruft-util/perlin.hpp

/*
 * This file is part of libgim.
 *
 * libgim 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.
 * 
 * libgim 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 libgim.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Copyright 2011 Danny Robson <danny@nerdcruft.net>
 */

#ifndef __UTIL_PERLIN_HPP
#define __UTIL_PERLIN_HPP

#include <cstdint>
#include <cstdlib>


namespace util {
    struct perlin {
        typedef size_t seed_t;

        unsigned octaves;
        double   frequency;
        double   persistence;
        seed_t   seed;

        perlin ();
        perlin (unsigned octaves,
                double   frequency,
                double   persistence,
                seed_t   seed);

        double sample (double x, double y) const;

    protected:
        double generate (intmax_t x, intmax_t y) const;
        double eval     (double   x, double   y) const;
    };

    void perlin2d (uint8_t *restrict pixels, size_t width, size_t height, const perlin&);
}


#endif