Akso - Audio DSP Platform

sinoid

$\text{[math]}$

sine wave oscillator with a set of modulations fm=internal fm width (filtered output) phase=phase offset of "cosine" part of ring modulation feed=amount of ring modulation of sine and 2nd sineshape part. Increases feedback loop of output into the 2nd sineshaper. LP and HP filters filter the internal FM, ringmodulation and the output signal. An internal counter can switch the play-direction after x-amount of zero-crossings of the phase. This rate also updates the position of the internal sine-lfo as a phase-offset.

Author: Remco van der Most

License: BSD

Github: sss/osc/sinoid.axo

Inlets

frac32.bipolar pitch

frac32 fmw

frac32 rate

frac32buffer frequency

frac32buffer phase

bool32 rst

Outlets

frac32buffer.bipolar sine wave

Parameters

frac32.u.map phase

int32 Scnt

frac32.s.map.kpitch rate

frac32.s.map.pitch pitch

frac32.s.map.pitch hp

frac32.s.map.pitch lp

bool32.tgl dir

frac32.s.map FM

frac32.s.map feed

Declaration

uint32_t Phase;
int32_t val1;
int32_t val2;
int32_t feed;
int32_t cnt;
uint32_t pv;
int dir;
int trig;
int32_t offset;
uint32_t LFO;
int rst;

Init

Phase = 0;
dir = 1;

Control Rate

int32_t freq;
MTOFEXTENDED(param_pitch + inlet_pitch, freq);
if (param_dir > 0) {
  freq = freq * param_Scnt;
}
int32_t F;
MTOF(param_hp, F)
int32_t G;
MTOF(param_lp + inlet_pitch, G)
int32_t rate = param_rate;
rate = rate > 0 ? rate : -rate;
rate = ___SMMUL(param_rate << 3, rate << 2);
int32_t FM = ___SMMUL(freq, param_FM + inlet_fmw << 3) << 2;
int32_t RT;
MTOFEXTENDED(param_rate + inlet_rate, RT)
LFO += RT >> 8;

if ((inlet_rst > 0) && !rst) {
  rst = 1;
  LFO = 0;
} else if (inlet_rst <= 0) {
  rst = 0;
}

Audio Rate

int32_t Z = (freq + inlet_freq + (___SMMUL(val2 << 2, FM << 3) << 4)) * dir;
Phase += Z;

if (Z > 0) {
  if (pv > Phase) {
    cnt += 1;
    cnt = cnt > param_Scnt ? 0 : cnt;
    if (cnt == 0) {
      offset = LFO << 4;
      if (param_dir == 1) {
        dir = dir > 0 ? -1 : 1;
      }
    }
  }
}
if (Z < 0) {
  if (pv < Phase) {
    cnt += 1;
    cnt = cnt > param_Scnt ? 0 : cnt;
    if (cnt == 0) {
      offset = LFO << 4;
      if (param_dir == 1) {
        dir = dir > 0 ? -1 : 1;
      }
    }
  }
}

else if (feed < 0) {
  trig = 0;
}
int32_t r;
int32_t p2 = Phase + (inlet_phase << 4);
SINE2TINTERP(p2 + offset, r)
int32_t t;
SINE2TINTERP(p2 + (param_phase << 5), t)
r = r >> 6;
r += ___SMMUL(t >> 1, feed);

val1 = ___SMMLA((r - val1) << 1, F, val1);
val2 = ___SMMLA((r - val1 - val2) << 1, G, val2);
outlet_wave = val2;

feed = __SSAT(___SMMUL(val2, param_feed << 4) << 3, 29);
pv = Phase;