Filter.h

/*
 * This file is part of libsidplayfp, a SID player engine.
 *
 * Copyright 2011-2017 Leandro Nini <drfiemost@users.sourceforge.net>
 * Copyright 2007-2010 Antti Lankila
 * Copyright 2004 Dag Lem <resid@nimrod.no>
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
 
#ifndef FILTER_H
#define FILTER_H
 
namespace reSIDfp
{
 
class Filter
{
protected:
    unsigned short* currentGain;
 
    unsigned short* currentMixer;
 
    unsigned short* currentSummer;
 
    unsigned short* currentResonance;
 
    int Vhp;
 
    int Vbp;
 
    int Vlp;
 
    int ve;
 
    unsigned int fc;
 
    bool filt1, filt2, filt3, filtE;
 
    bool voice3off;
 
    bool hp, bp, lp;
 
    unsigned char vol;
 
private:
    bool enabled;
 
    unsigned char filt;
 
protected:
    virtual void updatedCenterFrequency() = 0;
 
    virtual void updateResonance(unsigned char res) = 0;
 
    virtual void updatedMixing() = 0;
 
public:
    Filter() :
        currentGain(nullptr),
        currentMixer(nullptr),
        currentSummer(nullptr),
        currentResonance(nullptr),
        Vhp(0),
        Vbp(0),
        Vlp(0),
        ve(0),
        fc(0),
        filt1(false),
        filt2(false),
        filt3(false),
        filtE(false),
        voice3off(false),
        hp(false),
        bp(false),
        lp(false),
        vol(0),
        enabled(true),
        filt(0) {}
 
    virtual ~Filter() {}
 
    virtual int clock(int v1, int v2, int v3) = 0;
 
    void enable(bool enable);
 
    void reset();
 
    void writeFC_LO(unsigned char fc_lo);
 
    void writeFC_HI(unsigned char fc_hi);
 
    void writeRES_FILT(unsigned char res_filt);
 
    void writeMODE_VOL(unsigned char mode_vol);
 
    virtual void input(int input) = 0;
};
 
} // namespace reSIDfp
 
#endif