132 lines
No EOL
3.8 KiB
C
132 lines
No EOL
3.8 KiB
C
#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 % 3) == 0)
|
|
note_timbre = 0.75;
|
|
break;
|
|
case duty_fourth_down:
|
|
note_timbre = 0.0;
|
|
if ((envelope_index % 12) == 0)
|
|
note_timbre = 0.75;
|
|
if (((envelope_index % 12) % 4) != 1)
|
|
note_timbre = 0.75;
|
|
break;
|
|
case duty_third_down:
|
|
note_timbre = 0.5;
|
|
if ((envelope_index % 5) == 0)
|
|
note_timbre = 0.75;
|
|
break;
|
|
case duty_fifth_third_down:
|
|
note_timbre = 0.5;
|
|
if ((envelope_index % 5) == 0)
|
|
note_timbre = 0.75;
|
|
if ((envelope_index % 3) == 0)
|
|
note_timbre = 0.25;
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return frequency;
|
|
} |