NoiseGenerator.h

#ifndef NOISEGENERATOR_H
#define NOISEGENERATOR_H
/*
 * This is the Loris C++ Class Library, implementing analysis, 
 * manipulation, and synthesis of digitized sounds using the Reassigned 
 * Bandwidth-Enhanced Additive Sound Model.
 *
 * Loris is Copyright (c) 1999-2004 by Kelly Fitz and Lippold Haken
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *
 * NoiseGenerator.h
 *
 * Definition of a class representing a filtered noise generator, used 
 * as a modulator in bandwidth-enhanced synthesis.
 *
 * Kelly Fitz, 5 June 2003
 * loris@cerlsoundgroup.org
 *
 * http://www.cerlsoundgroup.org/Loris/
 *
 */

#include "Filter.h"

//  begin namespace
namespace Loris {

// ---------------------------------------------------------------------------
//  class NoiseGenerator
//
class NoiseGenerator
{
//  --- interface ---
public:
    //  construction
    //  copy and assign are free
    explicit NoiseGenerator( double initSeed = 1.0 );
    NoiseGenerator( const Filter & f, double initSeed = 1.0 );

    //  seed the random number generator and clear the filter's
    //  delay line:
    void reset( double newSeed );
    
    //  return the most-recently generated sample:
    double current( void ) const { return sample; }
    
    //  generate and return a new sample of 
    //  filtered noise:
    double next( void );
    double operator() ( void ) { return next(); }
    
    double next( double mean, double stddev = 1. );
    double operator() ( double mean, double stddev = 1. ) { return next( mean, stddev ); }


//  --- implementation ---
private:
    //  random number 
    inline double uniform( void );
    inline double gaussian_normal( void );

    double sample;  //  the most recently-computed noise sample
    Filter filter;  //  filter applied to random number generator

    // random number generator implementation:
    double u_seed;
    double gset;
    bool iset;
    
};


}   //  end of namespace Loris

#endif  /* ndef NOISEGENERATOR_H */

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