// Filtered Impulse Trains
class Fit {
public:
  int32_t coefLP[8];
  int32_t out[8];
  int32_t amp[8];
  int32_t y0[8];
  int32_t y1[8];
  uint32_t intPer;
  uint32_t subPer;
  uint32_t subSpl;
  uint16_t nextSpl;
  uint16_t cpt;
  void setFandFilters(float freq) {
    float period = 48000.0f / freq;
    intPer = (int)period;
    subPer = arm::float_to_q(period - intPer, 27);
    float c = 10.0f * freq / 48000.0f;
    for (int oct = 7; oct >= 0; oct--) {
      coefLP[oct] = arm::float_to_q(c, 32);
      c *= 0.5f;
    }
  }
  void setF(float freq) {
    float period = 48000.0f / freq;
    intPer = (int)period;
    subPer = arm::float_to_q(period - intPer, 27);
  }
  void init(void) {
    for (int oct = 0; oct < 8; oct++) {
      out[oct] = y0[oct] = y1[oct] = amp[oct] = 0;
    }
    nextSpl = subSpl = 0;
    cpt = 0;
  }
  int32_t proc(uint16_t spl) {
    if (spl == nextSpl) {
      int32_t _subSpl = (1 << 27) - subSpl;
      y0[7] = ___SMMUL(subSpl, amp[7]);
      y1[7] = ___SMMUL(_subSpl, amp[7]);
      if ((cpt & 1) == 0) {
        y0[6] = ___SMMUL(subSpl, amp[6]);
        y1[6] = ___SMMUL(_subSpl, amp[6]);
        if ((cpt & 3) == 0) {
          y0[5] = ___SMMUL(subSpl, amp[5]);
          y1[5] = ___SMMUL(_subSpl, amp[5]);
          if ((cpt & 7) == 0) {
            y0[4] = ___SMMUL(subSpl, amp[4]);
            y1[4] = ___SMMUL(_subSpl, amp[4]);
            if ((cpt & 15) == 0) {
              y0[3] = ___SMMUL(subSpl, amp[3]);
              y1[3] = ___SMMUL(_subSpl, amp[3]);
              if ((cpt & 31) == 0) {
                y0[2] = ___SMMUL(subSpl, amp[2]);
                y1[2] = ___SMMUL(_subSpl, amp[2]);
                if ((cpt & 63) == 0) {
                  y0[1] = ___SMMUL(subSpl, amp[1]);
                  y1[1] = ___SMMUL(_subSpl, amp[1]);
                  if ((cpt & 127) == 0) {
                    y0[0] = ___SMMUL(subSpl, amp[0]);
                    y1[0] = ___SMMUL(_subSpl, amp[0]);
                  }
                }
              }
            }
          }
        }
      }
      nextSpl = spl + intPer;
      subSpl += subPer;
      if (subSpl >= 1 << 27) {
        subSpl -= 1 << 27;
        nextSpl++;
      }
      cpt++;
    }
    int32_t outFit = 0;
    for (int oct = 0; oct < 8; oct++) {
      int32_t tmp = out[oct];
      tmp += y1[oct];
      tmp = ___SMMLS(coefLP[oct], tmp, tmp);
      // if(tmp<(1<<21)) tmp = 1<<21;
      outFit += tmp; //-(1<<21);
      out[oct] = tmp;

      y1[oct] = y0[oct];
      y0[oct] = 0;
    }

    return outFit * 4;
  }
};

uint32_t spl = 0;
Fit fits[12];

int8_t gates[128];
int32_t envs[8 * 12];
int32_t envc[8 * 12];

float f = 4186.009f / 2;
f *= 1.059463094f;
for (int i = 0; i < 12; i++) {
  fits[i].init();
  fits[i].setFandFilters(f);
  f *= 1.059463094f;
}

for (int i = 0; i < 128; i++) {
  gates[i] = 0;
}
for (int i = 0; i < 8 * 12; i++) {
  envs[i] = 0;
  envc[i] = 0;
}

float vib0 = inlet_vib0 * 1e-10f;
float vib1 = inlet_vib1 * 1e-10f;
float vib2 = inlet_vib2 * 1e-10f;
// C#
float f = 0.5f * 4186.009f * 1.059463094f;
fits[0].setF(f *vib0 + f);
f *= 1.059463094f;
fits[1].setF(0.5f * f * vib0 + f);
f *= 1.059463094f;
fits[2].setF(-f *vib0 + f);
f *= 1.059463094f;
fits[3].setF(f *vib1 + f);
f *= 1.059463094f;
fits[4].setF(-f *vib1 + f);
f *= 1.059463094f;
fits[5].setF(-f *vib2 + f);
f *= 1.059463094f;
fits[6].setF(0.9f * f * vib2 + f);
f *= 1.059463094f;
fits[7].setF(-0.9f * f * vib1 + f);
f *= 1.059463094f;
fits[8].setF(f *vib1 + f);
f *= 1.059463094f;
fits[9].setF(-f *vib0 + f);
f *= 1.059463094f;
fits[10].setF(0.7f * f * vib2 + f);
f *= 1.059463094f;
fits[11].setF(0.5f * f * vib2 + f);

float envTot = 0;
for (int i = 0; i < 8 * 12; i++) {
  int32_t b = envs[i];
  if (gates[13 + i] > 10)
    envs[i] = ___SMMLA(0x7FFFFFFF - param_A, (100 << 20) - b, b >> 1)
              << 1; // ascending
  else if (b > param_L)
    envs[i] = ___SMMUL(b, param_R1) << 1;
  else
    envs[i] = ___SMMUL(b, param_R2) << 1;
  envTot += envs[i];
}
int32_t comp = arm::float_to_q(10000000 / sqrtf(envTot + (1 << 27)), 27);
for (int i = 0; i < 8 * 12; i++) {
  envc[i] = ___SMMUL(envs[i], comp);
}
float totAmp = 0;
for (int i = 0; i < 12; i++) {
  for (int oct = 0; oct < 8; oct++) {
    totAmp += (fits[i].amp[oct] = envc[i + 12 * oct] << 4);
  }
}

int32_t accu = 0;
for (int nBlit = 0; nBlit < 12; nBlit++) {
  accu += fits[nBlit].proc(spl);
}

outlet_out = accu;

spl++;

if (status == MIDI_NOTE_ON + attr_midichannel) {
  gates[data1 & 0x7F] = data2 ? 100 : 0;
} else if (status == MIDI_NOTE_OFF + attr_midichannel) {
  gates[data1 & 0x7F] = 0;
} else if ((status == attr_midichannel + MIDI_CONTROL_CHANGE) &&
           (data1 == MIDI_C_ALL_NOTES_OFF)) {
  for (int i = 0; i < 128; i++)
    gates[data1 & 0x7F] = 0;
}