#include "generator.hpp"
/*
   sonnenlicht poly ensemble

   Copyright 2024 Gordon JC Pearce <gordonjcp@gjcp.net>

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
   SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
   OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

#include <math.h>
#include <string.h>

#include <cstdio>

#include "DistrhoPluginInfo.h"
#include "svf.hpp"

extern double sampleRate;
extern uint32_t bufferSize;

// unit-local global
static float envTc[2];

// Generator::Generator(uint32_t bufferSize, double xSampleRate) {
Generator::Generator() {
    // sampleRate = xSampleRate;
    output = new float[bufferSize];
    // create the phase increments for each semitone
    for (uint8_t i = 0; i < 12; i++) {
        phase[i] = 0;
        uint32_t f;
        f = (1 << 31) * (32.703 * powf(2, 0.083334 * i) / sampleRate);
        omega[i] = f;
    }

    // output filters
    // trumpet 4200 2.5
    // horn 1500 2.5
    tr2 = SVF(9500.0f, 0.707f);
    setEnvelope(0.5, 0.5);
}

Generator::~Generator() {
    delete output;
}

void Generator::runBlock(uint32_t frames) {
    Voice *v;
    uint32_t i;
    uint8_t k, p, d;
    float n;

    memset(output, 0, frames * sizeof(float));

    for (i = 0; i < frames; i++) {
        for (p = 0; p < 12; p++) {
            phase[p] += omega[p];
        }

        for (k = 0; k < NUM_VOICES; k++) {
            v = &voices[k];

            d = (phase[v->semi] & (0x20000000 >> v->oct)) != 0;
            n = d ? 0.25 : -0.25;
            v->vc34 = ((n - v->vc34) * v->c34) + v->vc34;
            n -= v->vc34;
            n *= d ? 1 : 0;
            v->vc78 = ((n - v->vc78) * v->c78) + v->vc78;
            v->vc107 = ((v->vc78 - v->vc107) * v->c107) + v->vc107;

            d = (phase[v->semi] & (0x40000000 >> v->oct)) != 0;
            n = d ? 0.25 : -0.25;
            v->vc33 = ((n - v->vc33) * v->c33) + v->vc33;
            n -= v->vc33;
            n *= d ? 1 : 0;
            v->vc22 = ((n - v->vc22) * v->c22) + v->vc22;
            v->vc31 = ((v->vc22 - v->vc31) * v->c31) + v->vc31;

            v->vca = ((v->gate - v->vca) * envTc[v->vcatc]) + v->vca;

            float v4 = (v->vc78 - v->vc107);
            float v8 = (v->vc22 - v->vc31);

            output[i] += 0.25 * (v4 + v8) * v->vca;
        }
    }
    tr2.runSVF(output, output, frames);
}

void Voice::startNote(uint8_t key) {
    // start a new note
    // violin and viola filter params
    float fc = 88.4 * powf(2, 0.083334 * (key - 24));
    c34 = 1 - exp(-6.283 * fc / sampleRate);
    c33 = 1 - exp(-6.283 * fc / 2 / sampleRate);

    // violin register
    fc = 4000 + 65.8 * powf(2, 0.08 * (key - 24));
    c78 = 1 - exp(-6.283 * fc / sampleRate);
    c107 = 1 - exp(-6.283 * 154.0 / sampleRate);

    // viola register
    fc = 3000 + 65.8 * powf(2, 0.07 * (key - 24));
    c22 = 1 - exp(-6.283 * fc / sampleRate);
    c31 = 1 - exp(-6.283 * 150.0 / sampleRate);

    gate = 1;
    vcatc = 0;
    semi = key % 12, oct = (key / 12 - 3);
}

void Voice::stopNote() {
    gate = 0;
    vcatc = 1;
}

void Generator::setEnvelope(float attack, float sustain) {
    envTc[0] = ((96 * powf(100, -attack)) / sampleRate);
    envTc[1] = ((48 * powf(100, -sustain)) / sampleRate);
}