nativePWM
pulse width modulation oscillator with "active" control Bandwith limited
Inlets
bool32 active
frac32.bipolar pitch
frac32.bipolar pulse width. Zero corresponds to 50% duty cycle.
Outlets
frac32buffer.bipolar pwm wave, anti-aliased
Parameters
frac32.s.map.pitch pitch
Declaration
int32_t osc_p;
static const int blepvoices = 8;
int16_t *oscp[blepvoices];
uint32_t nextvoice;
int32_t pwmp;
Init
int j;
for (j = 0; j < blepvoices; j++)
oscp[j] = &blept[BLEPSIZE - 1];
nextvoice = 0;
Control Rate
if (inlet_active > 0) {
uint32_t freq;
MTOFEXTENDED(param_pitch + inlet_pitch, freq);
int j;
int16_t *lastblep = &blept[BLEPSIZE - 1];
for (j = 0; j < BUFSIZE; j++) {
int i;
int p;
p = osc_p;
osc_p = p + freq;
int32_t sum = 0;
if (((int32_t)osc_p) >= ((int32_t)(osc_p - pwmp))) {
if ((osc_p > 0) && !(p > 0)) { // dispatch
nextvoice = (nextvoice + 1) & (blepvoices - 1);
int32_t x = 0;
if (freq >> 24)
x = osc_p / (freq >> 6);
else if (freq)
x = (osc_p << 6) / freq;
oscp[nextvoice] = &blept[x];
pwmp = ((1 << 27) + inlet_pw) << 4;
}
if (((osc_p - pwmp) > 0) && !((p - pwmp) > 0)) { // dispatch
nextvoice = (nextvoice + 1) & (blepvoices - 1);
uint32_t x = 0;
if (freq >> 24)
x = (osc_p - pwmp) / (freq >> 6);
else if (freq)
x = ((osc_p - pwmp) << 6) / (freq);
oscp[nextvoice] = &blept[x];
}
} else {
if (((osc_p - pwmp) > 0) && !((p - pwmp) > 0)) { // dispatch
nextvoice = (nextvoice + 1) & (blepvoices - 1);
uint32_t x = 0;
if (freq >> 24)
x = (osc_p - pwmp) / (freq >> 6);
else if (freq)
x = ((osc_p - pwmp) << 6) / (freq);
oscp[nextvoice] = &blept[x];
}
if ((osc_p > 0) && !(p > 0)) { // dispatch
nextvoice = (nextvoice + 1) & (blepvoices - 1);
int32_t x = 0;
if (freq >> 24)
x = osc_p / (freq >> 6);
else if (freq)
x = (osc_p << 6) / freq;
oscp[nextvoice] = &blept[x];
pwmp = ((1 << 27) + inlet_pw) << 4;
}
}
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;
outlet_wave[j] = sum << 13;
}
}
Audio Rate
if (inlet_active == 0) {
outlet_wave = 0;
}