Carla/source/backend/native/zynaddsubfx/Effects/Distorsion.cpp

/*
  ZynAddSubFX - a software synthesizer

  Distorsion.cpp - Distorsion effect
  Copyright (C) 2002-2005 Nasca Octavian Paul
  Author: Nasca Octavian Paul

  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 or later) 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

*/

#include "Distorsion.h"
#include "../DSP/AnalogFilter.h"
#include "../Misc/WaveShapeSmps.h"
#include <cmath>

Distorsion::Distorsion(bool insertion_, float *efxoutl_, float *efxoutr_)
    :Effect(insertion_, efxoutl_, efxoutr_, NULL, 0),
      Pvolume(50),
      Pdrive(90),
      Plevel(64),
      Ptype(0),
      Pnegate(0),
      Plpf(127),
      Phpf(0),
      Pstereo(0),
      Pprefiltering(0)
{
    lpfl = new AnalogFilter(2, 22000, 1, 0);
    lpfr = new AnalogFilter(2, 22000, 1, 0);
    hpfl = new AnalogFilter(3, 20, 1, 0);
    hpfr = new AnalogFilter(3, 20, 1, 0);
    setpreset(Ppreset);
    cleanup();
}

Distorsion::~Distorsion()
{
    delete lpfl;
    delete lpfr;
    delete hpfl;
    delete hpfr;
}

//Cleanup the effect
void Distorsion::cleanup(void)
{
    lpfl->cleanup();
    hpfl->cleanup();
    lpfr->cleanup();
    hpfr->cleanup();
}


//Apply the filters
void Distorsion::applyfilters(float *efxoutl, float *efxoutr)
{
    lpfl->filterout(efxoutl);
    hpfl->filterout(efxoutl);
    if(Pstereo != 0) { //stereo
        lpfr->filterout(efxoutr);
        hpfr->filterout(efxoutr);
    }
}


//Effect output
void Distorsion::out(const Stereo<float *> &smp)
{
    float inputvol = powf(5.0f, (Pdrive - 32.0f) / 127.0f);
    if(Pnegate)
        inputvol *= -1.0f;

    if(Pstereo) //Stereo
        for(int i = 0; i < synth->buffersize; ++i) {
            efxoutl[i] = smp.l[i] * inputvol * pangainL;
            efxoutr[i] = smp.r[i] * inputvol * pangainR;
        }
    else //Mono
        for(int i = 0; i < synth->buffersize; ++i)
            efxoutl[i] = (smp.l[i] * pangainL + smp.r[i] * pangainR) * inputvol;

    if(Pprefiltering)
        applyfilters(efxoutl, efxoutr);

    waveShapeSmps(synth->buffersize, efxoutl, Ptype + 1, Pdrive);
    if(Pstereo)
        waveShapeSmps(synth->buffersize, efxoutr, Ptype + 1, Pdrive);

    if(!Pprefiltering)
        applyfilters(efxoutl, efxoutr);

    if(!Pstereo)
        memcpy(efxoutr, efxoutl, synth->bufferbytes);

    float level = dB2rap(60.0f * Plevel / 127.0f - 40.0f);
    for(int i = 0; i < synth->buffersize; ++i) {
        float lout = efxoutl[i];
        float rout = efxoutr[i];
        float l    = lout * (1.0f - lrcross) + rout * lrcross;
        float r    = rout * (1.0f - lrcross) + lout * lrcross;
        lout = l;
        rout = r;

        efxoutl[i] = lout * 2.0f * level;
        efxoutr[i] = rout * 2.0f * level;
    }
}


//Parameter control
void Distorsion::setvolume(unsigned char _Pvolume)
{
    Pvolume = _Pvolume;

    if(insertion == 0) {
        outvolume = powf(0.01f, (1.0f - Pvolume / 127.0f)) * 4.0f;
        volume    = 1.0f;
    }
    else
        volume = outvolume = Pvolume / 127.0f;
    if(Pvolume == 0)
        cleanup();
}

void Distorsion::setlpf(unsigned char _Plpf)
{
    Plpf = _Plpf;
    float fr = expf(powf(Plpf / 127.0f, 0.5f) * logf(25000.0f)) + 40.0f;
    lpfl->setfreq(fr);
    lpfr->setfreq(fr);
}

void Distorsion::sethpf(unsigned char _Phpf)
{
    Phpf = _Phpf;
    float fr = expf(powf(Phpf / 127.0f, 0.5f) * logf(25000.0f)) + 20.0f;
    hpfl->setfreq(fr);
    hpfr->setfreq(fr);
}


void Distorsion::setpreset(unsigned char npreset)
{
    const int     PRESET_SIZE = 11;
    const int     NUM_PRESETS = 6;
    unsigned char presets[NUM_PRESETS][PRESET_SIZE] = {
        //Overdrive 1
        {127, 64, 35, 56, 70, 0, 0, 96,  0,   0, 0},
        //Overdrive 2
        {127, 64, 35, 29, 75, 1, 0, 127, 0,   0, 0},
        //A. Exciter 1
        {64,  64, 35, 75, 80, 5, 0, 127, 105, 1, 0},
        //A. Exciter 2
        {64,  64, 35, 85, 62, 1, 0, 127, 118, 1, 0},
        //Guitar Amp
        {127, 64, 35, 63, 75, 2, 0, 55,  0,   0, 0},
        //Quantisize
        {127, 64, 35, 88, 75, 4, 0, 127, 0,   1, 0}
    };

    if(npreset >= NUM_PRESETS)
        npreset = NUM_PRESETS - 1;
    for(int n = 0; n < PRESET_SIZE; ++n)
        changepar(n, presets[npreset][n]);
    if(!insertion) //lower the volume if this is system effect
        changepar(0, (int) (presets[npreset][0] / 1.5f));
    Ppreset = npreset;
    cleanup();
}


void Distorsion::changepar(int npar, unsigned char value)
{
    switch(npar) {
        case 0:
            setvolume(value);
            break;
        case 1:
            setpanning(value);
            break;
        case 2:
            setlrcross(value);
            break;
        case 3:
            Pdrive = value;
            break;
        case 4:
            Plevel = value;
            break;
        case 5:
            if(value > 13)
                Ptype = 13;  //this must be increased if more distorsion types are added
            else
                Ptype = value;
            break;
        case 6:
            if(value > 1)
                Pnegate = 1;
            else
                Pnegate = value;
            break;
        case 7:
            setlpf(value);
            break;
        case 8:
            sethpf(value);
            break;
        case 9:
            Pstereo = (value > 1) ? 1 : value;
            break;
        case 10:
            Pprefiltering = value;
            break;
    }
}

unsigned char Distorsion::getpar(int npar) const
{
    switch(npar) {
        case 0:  return Pvolume;
        case 1:  return Ppanning;
        case 2:  return Plrcross;
        case 3:  return Pdrive;
        case 4:  return Plevel;
        case 5:  return Ptype;
        case 6:  return Pnegate;
        case 7:  return Plpf;
        case 8:  return Phpf;
        case 9:  return Pstereo;
        case 10: return Pprefiltering;
        default: return 0; //in case of bogus parameter number
    }
}