5 // these are imported from audio.c
6 extern uint16_t envelope_index;
7 extern float note_timbre;
8 extern float polyphony_rate;
10 voice_type voice = default_voice;
12 void set_voice(voice_type v) {
16 void voice_iterate() {
17 voice = (voice + 1) % number_of_voices;
20 void voice_deiterate() {
21 voice = (voice - 1) % number_of_voices;
24 float voice_envelope(float frequency) {
25 // envelope_index ranges from 0 to 0xFFFF, which is preserved at 880.0 Hz
26 uint16_t compensated_index = (uint16_t)((float)envelope_index * (880.0 / frequency));
30 note_timbre = TIMBRE_50;
36 switch (compensated_index) {
38 frequency = frequency / 4;
39 note_timbre = TIMBRE_12;
43 frequency = frequency / 2;
44 note_timbre = TIMBRE_12;
48 note_timbre = .125 - pow(((float)compensated_index - 20) / (200 - 20), 2)*.125;
57 // case octave_crunch:
58 // polyphony_rate = 0;
59 // switch (compensated_index) {
63 // frequency = frequency / 2;
64 // note_timbre = TIMBRE_12;
70 // frequency = frequency * 2;
71 // note_timbre = TIMBRE_12;
75 // note_timbre = TIMBRE_12;
81 // This slows the loop down a substantial amount, so higher notes may freeze
83 switch (compensated_index) {
88 // note_timbre = (sin((float)compensated_index/10000*OCS_SPEED) * OCS_AMP / 2) + .5;
89 // triangle wave is a bit faster
90 note_timbre = (float)abs((compensated_index*OCS_SPEED % 3000) - 1500) * ( OCS_AMP / 1500 ) + (1 - OCS_AMP) / 2;
95 case duty_octave_down:
97 note_timbre = (envelope_index % 2) * .125 + .375 * 2;
98 if ((envelope_index % 4) == 0)
100 if ((envelope_index % 8) == 0)
103 case delayed_vibrato:
105 note_timbre = TIMBRE_50;
106 #define VOICE_VIBRATO_DELAY 150
107 #define VOICE_VIBRATO_SPEED 50
108 switch (compensated_index) {
109 case 0 ... VOICE_VIBRATO_DELAY:
112 frequency = frequency * vibrato_lut[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1))/1000*VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)];
116 // case delayed_vibrato_octave:
117 // polyphony_rate = 0;
118 // if ((envelope_index % 2) == 1) {
119 // note_timbre = 0.55;
121 // note_timbre = 0.45;
123 // #define VOICE_VIBRATO_DELAY 150
124 // #define VOICE_VIBRATO_SPEED 50
125 // switch (compensated_index) {
126 // case 0 ... VOICE_VIBRATO_DELAY:
129 // frequency = frequency * VIBRATO_LUT[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1))/1000*VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)];
133 // case duty_fifth_down:
134 // note_timbre = 0.5;
135 // if ((envelope_index % 3) == 0)
136 // note_timbre = 0.75;
138 // case duty_fourth_down:
139 // note_timbre = 0.0;
140 // if ((envelope_index % 12) == 0)
141 // note_timbre = 0.75;
142 // if (((envelope_index % 12) % 4) != 1)
143 // note_timbre = 0.75;
145 // case duty_third_down:
146 // note_timbre = 0.5;
147 // if ((envelope_index % 5) == 0)
148 // note_timbre = 0.75;
150 // case duty_fifth_third_down:
151 // note_timbre = 0.5;
152 // if ((envelope_index % 5) == 0)
153 // note_timbre = 0.75;
154 // if ((envelope_index % 3) == 0)
155 // note_timbre = 0.25;