Akso - Audio DSP Platform

blepped3

$\text{[math]}$

blepped multi-waveform oscillator Bandwith limited

Author: Remco van der Most

License: BSD

Github: sss/osc/blepped3.axo

Inlets

int32 selects waveform

frac32 pitch

frac32 self

frac32.bipolar use frequency (note) offset to add to root pitch

frac32.bipolar beatrate

frac32buffer external mod width

Outlets

frac32buffer.bipolar triangle wave, anti-aliased

Parameters

int32 index2wave

int32 note2wave

frac32.s.map.pitch pitch

frac32.s.map.pitch Poffset

bool32.tgl PoffsetOn

bool32.tgl LFO

bool32.tgl negative

bool32.tgl sync

frac32.s.map self

frac32.s.map mod

int32.hradio wave

Declaration

uint32_t osc_p;
int32_t Osc_p;
bool trg;
int32_t preset;
int wave;
int k;
int32_t Offset;
int32_t beat;
static const int blepvoices = 8;
const int16_t *oscp[blepvoices];
int16_t *Oscp[blepvoices];
int16_t amp[blepvoices];
uint32_t nextvoice;
int32_t vgain[blepvoices];
int32_t i0;
int32_t sync;
int32_t max;
int32_t val;
int32_t dval1;
int32_t dval2;

int32_t in[attr_poly][BUFSIZE];
int32_t out[attr_poly][BUFSIZE];
int i;

int32_t SIN(int32_t pitch, int32_t fm, int32_t self) {

  uint32_t freq;
  MTOFEXTENDED(pitch, freq);
  freq += Offset + beat;
  int32_t FM;
  int32_t fM = ___SMMUL(fm << 4, freq) << 3;
  int32_t Fm = ___SMMUL(self << 2, freq);
  int j;
  for (j = 0; j < BUFSIZE; j++) {
    FM = ___SMMUL(in[parent->polyIndex][j] << 3, fM) +
             ___SMMUL(out[parent->polyIndex][j] << 3, Fm << 2)
         << 3;
    int32_t tfreq = freq + FM;
    if (((in[parent->polyIndex][j] > 0) && !trg) && sync) {
      trg = 1;
      osc_p = 0;
    } else if (in[parent->polyIndex][j] <= 0) {
      trg = 0;
    }
    osc_p += tfreq;
    int32_t sine;
    SINE2TINTERP(osc_p, sine)
    int32_t tmp = sine >> 5;
    val += (tmp - val) >> 10;
    out[parent->polyIndex][j] = tmp - val;
  }
}
int32_t TRI(int32_t pitch, int32_t fm, int32_t self) {

  uint32_t freq;
  MTOFEXTENDED(pitch, freq);
  freq += Offset + beat;
  int32_t FM;
  int32_t fM = ___SMMUL(fm << 4, freq) << 3;
  int32_t Fm = ___SMMUL(self << 2, freq);
  int j;
  const int16_t *lastblep = &blt[BLEPSIZE - 1];
  for (j = 0; j < BUFSIZE; j++) {
    FM = ___SMMUL(in[parent->polyIndex][j] << 3, fM) +
             ___SMMUL(out[parent->polyIndex][j] << 3, Fm << 2)
         << 3;
    int32_t tfreq = freq + FM;
    // tfreq=tfreq>0?tfreq:-tfreq+1;
    int i;
    uint32_t p;
    p = osc_p;
    int32_t p3 = p - 2 * tfreq;
    int32_t tri;
    if (p3 > 0) {
      tri = ((1 << 30) - (p3)) >> 4;
    } else {
      tri = (p3 + (1 << 30)) >> 4;
    }
    osc_p = p + tfreq;
    //
    int i1 = sync > 0 ? in[parent->polyIndex][j] >> 2 : 0;
    if ((i1 > 0) && !(i0 > 0)) { // phase reset
      nextvoice = (nextvoice + 1) & (blepvoices - 1);
      int32_t x = 64 - ((-i0 << 6) / (i1 - i0));
      oscp[nextvoice] = &blept[x];
      vgain[nextvoice] = vgain[nextvoice] =
          (((x * (tfreq >> 7)) + (((uint32_t)p) >> 1))) >> 18;
      osc_p = x * (tfreq >> 6);
    } else if ((osc_p > 0) && !(p > 0)) { // dispatch
      nextvoice = (nextvoice + 1) & (blepvoices - 1);
      int32_t x = osc_p / (tfreq >> 6);
      oscp[nextvoice] = &blept[x];
      vgain[nextvoice] = 1 << 13;
    }
    i0 = i1;
    //
    if ((((int32_t)osc_p) > 0) ^ (((int32_t)p) > 0)) { // dispatch
      if ((freq >> 6) > 0) {
        nextvoice = (nextvoice + 1) & (blepvoices - 1);
        int32_t x = (osc_p & 0x7FFFFFFF) / (((uint32_t)tfreq) >> 6);
        oscp[nextvoice] = &blt[x];
        amp[nextvoice] = (((int32_t)osc_p) < 0) ? tfreq >> 16 : -(tfreq >> 16);
      }
    }
    int32_t sum = 0;
    for (i = 0; i < blepvoices; i++) { // sample
      const int16_t *t = oscp[i];
      sum += (*t) * amp[i];
      t += 64;
      if (t >= lastblep)
        t = lastblep;
      oscp[i] = t;
    }
    int32_t tmp = tri + (sum >> 3);
    val += (tmp - val) >> 10;
    out[parent->polyIndex][j] = tmp - val;
  }
};

int32_t SQR(int32_t pitch, int32_t fm, int32_t self) {

  int32_t freq;
  MTOFEXTENDED(pitch, freq);
  freq += Offset + beat;
  int32_t FM;
  int32_t fM = ___SMMUL(fm << 4, freq) << 3;
  int32_t Fm = ___SMMUL(self << 2, freq);
  int j;
  int16_t *lastblep = &blept[BLEPSIZE - 1];
  for (j = 0; j < BUFSIZE; j++) {
    FM = ___SMMUL(in[parent->polyIndex][j] << 3, fM) +
             ___SMMUL(out[parent->polyIndex][j] << 3, Fm << 2)
         << 3;
    int32_t tfreq = freq + FM;
    tfreq = tfreq > 0 ? tfreq : -tfreq + 1;
    int i;
    int p;
    p = Osc_p;
    Osc_p = p + (tfreq << 1);
    int32_t sum = 0;
    int i1 = sync > 0 ? in[parent->polyIndex][j] >> 2 : 0;
    if ((i1 > 0) && !(i0 > 0)) { // phase reset
      int32_t x = 64 - ((-i0 << 6) / (i1 - i0));
      Osc_p = x * (tfreq >> 6);
      if (nextvoice & 1) {
        nextvoice = (nextvoice + 1) & (blepvoices - 1);
        oscp[nextvoice] = &blept[x];
      }
    } else if ((Osc_p > 0) && !(p > 0)) { // dispatch
      nextvoice = (nextvoice + 1) & (blepvoices - 1);
      int32_t x = Osc_p / (tfreq >> 5);
      Oscp[nextvoice] = &blept[x];
    }
    i0 = i1;
    for (i = 0; i < blepvoices; i++) { // sample
      int16_t *t = Oscp[i];
      if (i & 1)
        sum += *t;
      else
        sum -= *t;
      t += 64;
      if (t >= lastblep)
        t = lastblep;
      Oscp[i] = t;
    }
    sum -= ((((nextvoice + 1) & 1) << 1) - 1) << 13;
    int32_t tmp = sum << 13;
    val += (tmp - val) >> 10;
    out[parent->polyIndex][j] = tmp - val;
  }
}

int32_t SAW(int32_t pitch, int32_t fm, int32_t self, int dir) {

  int32_t freq;
  MTOFEXTENDED(pitch, freq);
  freq += Offset + beat;
  int32_t FM;
  int32_t fM = ___SMMUL(fm << 4, freq) << 3;
  int32_t Fm = ___SMMUL(self << 2, freq);
  int j;
  int16_t *lastblep = &blept[BLEPSIZE - 1];
  for (j = 0; j < BUFSIZE; j++) {
    int i;
    int p;
    FM = ___SMMUL(in[parent->polyIndex][j] << 3, fM) +
             ___SMMUL(out[parent->polyIndex][j] << 3, Fm << 2)
         << 3;
    int32_t tfreq = freq + FM;
    tfreq = tfreq > 0 ? tfreq : -tfreq + 1;
    p = Osc_p;
    Osc_p = p + tfreq;
    int32_t sum = 0;
    int i1 = sync > 0 ? in[parent->polyIndex][j] >> 2 : 0;
    if ((i1 > 0) && !(i0 > 0)) { // phase reset
      nextvoice = (nextvoice + 1) & (blepvoices - 1);
      int32_t x = 64 - ((-i0 << 6) / (i1 - i0));
      Oscp[nextvoice] = &blept[x];
      vgain[nextvoice] = vgain[nextvoice] =
          (((x * (tfreq >> 7)) + (((uint32_t)p) >> 1))) >> 18;
      Osc_p = x * (tfreq >> 6);
    } else if ((Osc_p > 0) && !(p > 0)) { // dispatch
      nextvoice = (nextvoice + 1) & (blepvoices - 1);
      int32_t x = Osc_p / (tfreq >> 6);
      Oscp[nextvoice] = &blept[x];
      vgain[nextvoice] = 1 << 13;
    }
    i0 = i1;

    for (i = 0; i < blepvoices; i++) { // sample
      int16_t *t = Oscp[i];
      sum += (16384 - (*t)) * vgain[i];
      t += 64;
      if (t >= lastblep)
        t = lastblep;
      Oscp[i] = t;
    }
    // sum = -sum;
    uint32_t g = Osc_p;
    int32_t tmp = ((g >> 5) + sum - (1 << 26)) * dir;
    val += (tmp - val) >> 10;
    out[parent->polyIndex][j] = tmp - val;
  }
}

Init

int j;
for (j = 0; j < blepvoices; j++) {
  oscp[j] = &blt[BLEPSIZE - 1];
  Oscp[j] = &blept[BLEPSIZE - 1];
  amp[j] = 0;
  i0 = 0;
}
nextvoice = 0;

Control Rate

sync = param_sync;
int32_t offset = (parent->polyIndex) * param_index2wave;
beat = inlet_beatrate >> 4;
preset = (param_wave + offset + inlet_wave);

wave = preset - preset / 5 * 5;
wave += wave < 0 ? 5 : 0;
int32_t Pitch = param_pitch + inlet_pitch;
// int32_t Not=(Pitch>>21)&255;
Offset = 0;
if (param_PoffsetOn > 0) {
  MTOFEXTENDED(inlet_Poffset + param_Poffset, Offset)
  if (param_LFO > 0) {
    Offset = Offset >> 10;
  }
  if (param_negative > 0) {
    Offset = -Offset;
  }
}

for (i = 0; i < BUFSIZE; i++) {
  in[parent->polyIndex][i] = inlet_mod[i];
}
int32_t P2 = Pitch + ((39 << 21) / 100);
int32_t Self = param_self + inlet_self << 1;
if (wave == 0) {
  SIN(Pitch, param_mod, Self);
}
if (wave == 1) {
  TRI(Pitch, param_mod, Self);
}
if (wave == 2) {
  SAW(Pitch, param_mod, Self, 1);
}
if (wave == 3) {
  SAW(Pitch, param_mod, Self, -1);
}
if (wave == 4) {
  SQR(Pitch, param_mod, Self);
}

for (i = 0; i < BUFSIZE; i++) {
  outlet_wave[i] = out[parent->polyIndex][i];
}