/*
  ZynAddSubFX - a software synthesizer

  SV Filter.h - Several state-variable filters
  Copyright (C) 2002-2005 Nasca Octavian Paul
  Author: Nasca Octavian Paul

  Modified for rakarrack by Josep Andreu

  This program is free software; you can redistribute it and/or modify
  it under the terms of version 2 of the GNU General Public License
  as published by the Free Software Foundation.

  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 (version 2) for more details.

  You should have received a copy of the GNU General Public License (version 2)
  along with this program; if not, write to the Free Software Foundation,
  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

*/

#ifndef SV_FILTER_H
#define SV_FILTER_H

#include "global.h"
#include "Filter_.h"
class SVFilter:public Filter_
{
public:
    SVFilter (unsigned char Ftype, float Ffreq, float Fq,
              unsigned char Fstages);
    ~SVFilter ();
    void filterout (float * smp);
    void setfreq (float frequency);
    void setfreq_and_q (float frequency, float q_);
    void setq (float q_);

    void settype (int type_);
    void setgain (float dBgain);
    void setstages (int stages_);
    void cleanup ();

private:
    struct fstage {
        float low, high, band, notch;
    } st[MAX_FILTER_STAGES + 1];

    struct parameters {
        float f, q, q_sqrt;
    } par, ipar;


    void singlefilterout (float * smp, fstage & x, parameters & par);
    void computefiltercoefs ();
    int type;			//The type of the filter (LPF1,HPF1,LPF2,HPF2...)
    int stages;			//how many times the filter is applied (0->1,1->2,etc.)
    int abovenq;			//this is 1 if the frequency is above the nyquist
    int oldabovenq;
    int needsinterpolation, firsttime;

    float freq;		//Frequency given in Hz
    float q;			//Q factor (resonance or Q factor)
    float gain;		//the gain of the filter (if are shelf/peak) filters

};


#endif
