noise.h

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/*
    Copyright (C) 2000-2007 Paul Davis

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#ifndef NOISE_H
#define NOISE_H

/* Can be overrriden with any code that produces whitenoise between 0.0f and
 * 1.0f, eg (random() / (float)RAND_MAX) should be a good source of noise, but
 * its expensive */
#ifndef GDITHER_NOISE
#define GDITHER_NOISE gdither_noise()
#endif

inline static float gdither_noise()
{
    static uint32_t rnd = 23232323;
    rnd = (rnd * 196314165) + 907633515;

    return rnd * 2.3283064365387e-10f;
}

#endif