src/mt32/freeverb/comb.h

// Comb filter class declaration
//
// Written by Jezar at Dreampoint, June 2000
// http://www.dreampoint.co.uk
// This code is public domain

#ifndef _comb_
#define _comb_

#include "denormals.h"
#include "../FileStream.h"

class comb
{
public:
                        comb();
                void    setbuffer(float *buf, int size);
                void    deletebuffer();
        inline  float   process(float input);
                void    mute();
                void    setdamp(float val);
                float   getdamp();
                void    setfeedback(float val);
                float   getfeedback();

                                        void saveState( std::ostream &stream );
                                        void loadState( std::istream &stream );
private:
        float   feedback = 0;
        float   filterstore;
        float   damp1 = 0;
        float   damp2 = 0;
        float   *buffer = NULL;
        int     bufsize = 0;
        int     bufidx;
};


// Big to inline - but crucial for speed

inline float comb::process(float input)
{
        float output;

        output = undenormalise(buffer[bufidx]);

        filterstore = undenormalise((output*damp2) + (filterstore*damp1));

        buffer[bufidx] = input + (filterstore*feedback);

        if (++bufidx>=bufsize) bufidx = 0;

        return output;
}

#endif //_comb_