/*
    Chorus.cpp - Chorus and Flange effects

    Original ZynAddSubFX author Nasca Octavian Paul
    Copyright (C) 2002-2009 Nasca Octavian Paul
    Copyright 2009-2011, Alan Calvert
    Copyright 2014, Will Godfrey

    This file is part of yoshimi, which is free software: you can redistribute
    it and/or modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either version 2 of
    the License, or (at your option) any later version.

    yoshimi 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 along with
    yoshimi; if not, write to the Free Software Foundation, Inc., 51 Franklin
    Street, Fifth Floor, Boston, MA  02110-1301, USA.

    This file is derivative of ZynAddSubFX original code, modified September 2014
*/

#include "Misc/SynthEngine.h"
#include "Effects/Chorus.h"

#define MAX_CHORUS_DELAY 250.0f // ms

Chorus::Chorus(bool insertion_, float *const efxoutl_, float *efxoutr_, SynthEngine *_synth) :
    Effect(insertion_, efxoutl_, efxoutr_, NULL, 0),
    lfo(_synth),
    synth(_synth)
{
    dlk = drk = 0;
    maxdelay = (int)(MAX_CHORUS_DELAY / 1000.0f * synth->samplerate_f);
    delayl = new float[maxdelay];
    delayr = new float[maxdelay];
    setpreset(Ppreset);
    changepar(1, 64);
    lfo.effectlfoout(&lfol, &lfor);
    dl2 = getdelay(lfol);
    dr2 = getdelay(lfor);
    cleanup();
}


// get the delay value in samples; xlfo is the current lfo value
float Chorus::getdelay(float xlfo)
{
    float result = (Pflangemode) ? 0 : (delay + xlfo * depth) * synth->samplerate_f;

    //check if it is too big delay (caused bu erroneous setDelay() and setDepth()
    if ((result + 0.5) >= maxdelay)
    {
        synth->getRuntime().Log("WARNING: Chorus.C::getDelay(..) too big delay (see setdelay and setdepth funcs.)");
        result = maxdelay - 1.0;
    }
    return result;
}


// Apply the effect
void Chorus::out(float *smpsl, float *smpsr)
{
    const float one = 1.0f;
    dl1 = dl2;
    dr1 = dr2;
    lfo.effectlfoout(&lfol, &lfor);

    dl2 = getdelay(lfol);
    dr2 = getdelay(lfor);

    float inL, inR, tmpL, tmpR, tmp;
    for (int i = 0; i < synth->p_buffersize; ++i)
    {
        tmpL = smpsl[i];
        tmpR = smpsr[i];
        // LRcross
        inL = tmpL * (1.0f - lrcross) + tmpR * lrcross;
        inR = tmpR * (1.0f - lrcross) + tmpL * lrcross;

        // Left channel

        // compute the delay in samples using linear interpolation between the lfo delays
        mdel = (dl1 * (synth->p_buffersize - i) + dl2 * i) / synth->p_buffersize_f;
        if (++dlk >= maxdelay)
            dlk = 0;
        tmp = dlk - mdel + maxdelay * 2.0f; // where should I get the sample from
        // F2I(tmp, dlhi);
        dlhi = (tmp > 0.0f) ? (int)truncf(tmp) : (int)truncf(tmp - 1.0f);
        dlhi %= maxdelay;

        dlhi2 = (dlhi - 1 + maxdelay) % maxdelay;
        dllo = 1.0f - fmodf(tmp, one);
        efxoutl[i] = delayl[dlhi2] * dllo + delayl[dlhi] * (1.0f - dllo);
        delayl[dlk] = inL + efxoutl[i] * fb;

        // Right channel

        // compute the delay in samples using linear interpolation between the lfo delays
        mdel = (dr1 * (synth->p_buffersize - i) + dr2 * i) / synth->p_buffersize_f;
        if (++drk >= maxdelay)
            drk = 0;
        tmp = drk * 1.0f - mdel + maxdelay * 2.0f; // where should I get the sample from
        // F2I(tmp, dlhi);
        dlhi = (tmp > 0.0f) ? (int)truncf(tmp) : (int)truncf(tmp - 1.0f);
        dlhi %= maxdelay;
        dlhi2 = (dlhi - 1 + maxdelay) % maxdelay;
        dllo = 1.0f - fmodf(tmp, one);
        efxoutr[i] = delayr[dlhi2] * dllo + delayr[dlhi] * (1.0f - dllo);
        delayr[dlk] = inR + efxoutr[i] * fb;
    }

    if (Poutsub)
        for (int i = 0; i < synth->p_buffersize; ++i)
        {
            efxoutl[i] *= -1.0f;
            efxoutr[i] *= -1.0f;
        }

    for (int i = 0; i < synth->p_buffersize; ++i)
    {
        efxoutl[i] *= pangainL;
        efxoutr[i] *= pangainR;
    }
}


// Cleanup the effect
void Chorus::cleanup(void)
{
    for (int i = 0; i < maxdelay; ++i)
        delayl[i] = delayr[i] = 0.0f;
}


// Parameter control
void Chorus::setdepth(unsigned char Pdepth_)
{
    Pdepth = Pdepth_;
    depth = (powf(8.0f, (Pdepth / 127.0f) * 2.0f) - 1.0f) / 1000.0f; // seconds
}


void Chorus::setdelay(unsigned char Pdelay_)
{
    Pdelay = Pdelay_;
    delay = (powf(10.0f, (Pdelay / 127.0f) * 2.0f) - 1.0f) / 1000.0f; // seconds
}


void Chorus::setfb(unsigned char Pfb_)
{
    Pfb = Pfb_;
    fb = (Pfb - 64.0f) / 64.1f;
}


void Chorus::setvolume(unsigned char Pvolume_)
{
    Pvolume = Pvolume_;
    outvolume = Pvolume / 127.0f;
    volume = (!insertion) ? 1.0f : outvolume;
}


void Chorus::setpreset(unsigned char npreset)
{
    const int PRESET_SIZE = 12;
    const int NUM_PRESETS = 10;
    unsigned char presets[NUM_PRESETS][PRESET_SIZE] = {
        // Chorus1
        { 64, 64, 50, 0, 0, 90, 40, 85, 64, 119, 0, 0 },
        // Chorus2
        {64, 64, 45, 0, 0, 98, 56, 90, 64, 19, 0, 0 },
        // Chorus3
        {64, 64, 29, 0, 1, 42, 97, 95, 90, 127, 0, 0 },
        // Celeste1
        {64, 64, 26, 0, 0, 42, 115, 18, 90, 127, 0, 0 },
        // Celeste2
        {64, 64, 29, 117, 0, 50, 115, 9, 31, 127, 0, 1 },
        // Flange1
        {64, 64, 57, 0, 0, 60, 23, 3, 62, 0, 0, 0 },
        // Flange2
        {64, 64, 33, 34, 1, 40, 35, 3, 109, 0, 0, 0 },
        // Flange3
        {64, 64, 53, 34, 1, 94, 35, 3, 54, 0, 0, 1 },
        // Flange4
        {64, 64, 40, 0, 1, 62, 12, 19, 97, 0, 0, 0 },
        // Flange5
        {64, 64, 55, 105, 0, 24, 39, 19, 17, 0, 0, 1 }
    };

    if (npreset < 0xf)
    {
        if (npreset >= NUM_PRESETS)
            npreset = NUM_PRESETS - 1;
        for (int n = 0; n < PRESET_SIZE; ++n)
            changepar(n, presets[npreset][n]);
        Ppreset = npreset;
    }
    else
    {
        unsigned char preset = npreset & 0xf;
        unsigned char param = npreset >> 4;
        if (param == 0xf)
            param = 0;
        changepar(param, presets[preset][param]);
        if (insertion && (param == 0))
            changepar(0, presets[preset][0] / 2);
    }
}


void Chorus::changepar(int npar, unsigned char value)
{
    switch (npar)
    {
        case 0:
            setvolume(value);
            break;
        case 1:
            setpanning(value);
            break;
        case 2:
            lfo.Pfreq = value;
            lfo.updateparams();
            break;
        case 3:
            lfo.Prandomness = value;
            lfo.updateparams();
            break;
        case 4:
            lfo.PLFOtype = value;
            lfo.updateparams();
            break;
        case 5:
            lfo.Pstereo = value;
            lfo.updateparams();
            break;
        case 6:
            setdepth(value);
            break;
        case 7:
            setdelay(value);
            break;
        case 8:
            setfb(value);
            break;
        case 9:
            setlrcross(value);
            break;
        case 10:
            Pflangemode = (value > 1) ? 1 : value;
            break;
        case 11:
            Poutsub = (value > 1) ? 1 : value;
            break;
    }
}


unsigned char Chorus::getpar(int npar)
{
    switch (npar)
    {
        case 0:  return Pvolume;
        case 1:  return Ppanning;
        case 2:  return lfo.Pfreq;
        case 3:  return lfo.Prandomness;
        case 4:  return lfo.PLFOtype;
        case 5:  return lfo.Pstereo;
        case 6:  return Pdepth;
        case 7:  return Pdelay;
        case 8:  return Pfb;
        case 9:  return Plrcross;
        case 10: return Pflangemode;
        case 11: return Poutsub;
        default: return 0;
    }
}
