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#include "voices.h"
#include "stdlib.h"
// these are imported from audio.c
extern uint16_t envelope_index;
extern float note_timbre;
extern float polyphony_rate;
voice_type voice = duty_osc;
void set_voice(voice_type v) {
voice = v;
}
void voice_iterate() {
voice = (voice + 1) % number_of_voices;
}
void voice_deiterate() {
voice = (voice - 1) % number_of_voices;
}
float voice_envelope(float frequency) {
// envelope_index ranges from 0 to 0xFFFF, which is preserved at 880.0 Hz
uint16_t compensated_index = (uint16_t)((float)envelope_index * (880.0 / frequency));
switch (voice) {
case default_voice:
note_timbre = TIMBRE_50;
polyphony_rate = 0;
break;
case butts_fader:
polyphony_rate = 0;
switch (compensated_index) {
case 0 ... 9:
frequency = frequency / 4;
note_timbre = TIMBRE_12;
break;
case 10 ... 19:
frequency = frequency / 2;
note_timbre = TIMBRE_12;
break;
case 20 ... 200:
note_timbre = .125 - pow(((float)compensated_index - 20) / (200 - 20), 2)*.125;
break;
default:
note_timbre = 0;
break;
}
break;
case octave_crunch:
polyphony_rate = 0;
switch (compensated_index) {
case 0 ... 9:
case 20 ... 24:
case 30 ... 32:
frequency = frequency / 2;
note_timbre = TIMBRE_12;
break;
case 10 ... 19:
case 25 ... 29:
case 33 ... 35:
frequency = frequency * 2;
note_timbre = TIMBRE_12;
break;
default:
note_timbre = TIMBRE_12;
break;
}
break;
case duty_osc:
// This slows the loop down a substantial amount, so higher notes may freeze
polyphony_rate = 0;
switch (compensated_index) {
default:
#define OCS_SPEED 10
#define OCS_AMP .25
// sine wave is slow
// note_timbre = (sin((float)compensated_index/10000*OCS_SPEED) * OCS_AMP / 2) + .5;
// triangle wave is a bit faster
note_timbre = (float)abs((compensated_index*OCS_SPEED % 3000) - 1500) * ( OCS_AMP / 1500 ) + (1 - OCS_AMP) / 2;
break;
}
break;
case duty_octave_down:
polyphony_rate = 0;
note_timbre = (envelope_index % 2) * .125 + .375 * 2;
if ((envelope_index % 4) == 0)
note_timbre = 0.5;
if ((envelope_index % 8) == 0)
note_timbre = 0;
break;
case duty_fifth_down:
note_timbre = 0.5;
if ((envelope_index % 5) == 0)
note_timbre = 0.75;
break;
case duty_fourth_down:
if ((envelope_index % 12) == 0)
note_timbre = 0.25;
else
note_timbre = 0.5;
break;
default:
break;
}
return frequency;
}
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