tune
scaled tuning module for controlling the pitch oscillators scale is controlled by the rescale module the piano-control adds a frequency offset to each next note, starting from middle C (center can be adjusted using "offset"). This allows for a piano-like offset (though the frequency offset calculation is only a crude approximation to a real piano).
Inlets
frac32 pitch
int32 root
Outlets
frac32 scaled
Parameters
frac32.s.map piano
frac32.s.map offset
Attributes
objref scale
Declaration
;
int8_t octave;
int8_t semitone;
float32_t freq;
int32_t scaled;
int32_t frac_log(int32_t a) {
Float_t f;
f.f = a;
int32_t r1 = ((f.parts.exponent & 0x7F) - 18) << 24;
int32_t r3 = logt[f.parts.mantissa >> 15] << 10;
return r1 + r3;
}
Float_t f;
float32_t intfreq;
float32_t LOG1;
float32_t LOG2;
float32_t LOG3;
int32_t r1;
int32_t r2;
float32_t base;
float32_t scale[12];
Init
base = ((float32_t)330) / 1000;
f.f = 2 << 21;
r1 = ((f.parts.exponent & 0x7F) - 18) << 24;
r2 = logt[f.parts.mantissa >> 15] << 10;
LOG3 = r1 + r2;
f.f = base * (4 << 21);
r1 = ((f.parts.exponent & 0x7F) - 18) << 24;
r2 = logt[f.parts.mantissa >> 15] << 10;
LOG2 = r1 + r2;
Control Rate
int32_t pitch = (inlet_pitch >> 21) + 48;
octave = pitch / 12;
semitone = pitch - octave * 12;
octave = octave - 4;
int32_t root = inlet_root * 7;
root = root - (root / 12) * 12;
root = root < 0 ? root + 12 : root;
if (octave >= 0) {
intfreq = (base * attr_scale.scale[semitone]) * (1 << octave) *
attr_scale.scale[root];
}
if (octave < 0) {
intfreq = (base * attr_scale.scale[semitone]) / (1 << -octave) *
attr_scale.scale[root];
}
f.f = intfreq * (4 << 21);
r1 = ((f.parts.exponent & 0x7F) - 18) << 24;
r2 = logt[f.parts.mantissa >> 15] << 10;
LOG1 = r1 + r2;
scaled = ((LOG1 - LOG2) / LOG3) * (36 << 21);
int32_t piano;
piano = ___SMMUL(scaled + param_offset, param_piano);
int32_t P = piano;
P = P > 0 ? P : -P;
piano = ___SMMUL(piano << 3, P << 2);
outlet_scaled = scaled + piano;