quantum/audio/voices.c

   1 #include "voices.h"
   2 #include "audio.h"
   3 #include "stdlib.h"
   4
   5 // these are imported from audio.c
   6 extern uint16_t envelope_index;
   7 extern float note_timbre;
   8 extern float polyphony_rate;
   9
  10 voice_type voice = default_voice;
  11
  12 void set_voice(voice_type v) {
  13     voice = v;
  14 }
  15
  16 void voice_iterate() {
  17     voice = (voice + 1) % number_of_voices;
  18 }
  19
  20 void voice_deiterate() {
  21     voice = (voice - 1) % number_of_voices;
  22 }
  23
  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));
  27
  28     switch (voice) {
  29         case default_voice:
  30             note_timbre = TIMBRE_50;
  31             polyphony_rate = 0;
  32                 break;
  33
  34         case butts_fader:
  35             polyphony_rate = 0;
  36             switch (compensated_index) {
  37                 case 0 ... 9:
  38                     frequency = frequency / 4;
  39                     note_timbre = TIMBRE_12;
  40                         break;
  41
  42                 case 10 ... 19:
  43                     frequency = frequency / 2;
  44                     note_timbre = TIMBRE_12;
  45                         break;
  46
  47                 case 20 ... 200:
  48                     note_timbre = .125 - pow(((float)compensated_index - 20) / (200 - 20), 2)*.125;
  49                         break;
  50
  51                 default:
  52                     note_timbre = 0;
  53                         break;
  54             }
  55             break;
  56
  57         // case octave_crunch:
  58         //     polyphony_rate = 0;
  59         //     switch (compensated_index) {
  60         //         case 0 ... 9:
  61         //         case 20 ... 24:
  62         //         case 30 ... 32:
  63         //             frequency = frequency / 2;
  64         //             note_timbre = TIMBRE_12;
  65         //         break;
  66
  67         //         case 10 ... 19:
  68         //         case 25 ... 29:
  69         //         case 33 ... 35:
  70         //             frequency = frequency * 2;
  71         //             note_timbre = TIMBRE_12;
  72                //          break;
  73
  74         //         default:
  75         //             note_timbre = TIMBRE_12;
  76         //              break;
  77         //     }
  78                //  break;
  79
  80         case duty_osc:
  81             // This slows the loop down a substantial amount, so higher notes may freeze
  82             polyphony_rate = 0;
  83             switch (compensated_index) {
  84                 default:
  85                     #define OCS_SPEED 10
  86                     #define OCS_AMP   .25
  87                     // sine wave is slow
  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;
  91                         break;
  92             }
  93                 break;
  94
  95         case duty_octave_down:
  96             polyphony_rate = 0;
  97             note_timbre = (envelope_index % 2) * .125 + .375 * 2;
  98             if ((envelope_index % 4) == 0)
  99                 note_timbre = 0.5;
 100             if ((envelope_index % 8) == 0)
 101                 note_timbre = 0;
 102             break;
 103         case delayed_vibrato:
 104             polyphony_rate = 0;
 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:
 110                     break;
 111                 default:
 112                     frequency = frequency * vibrato_lut[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1))/1000*VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)];
 113                     break;
 114             }
 115             break;
 116         // case delayed_vibrato_octave:
 117         //     polyphony_rate = 0;
 118         //     if ((envelope_index % 2) == 1) {
 119         //         note_timbre = 0.55;
 120         //     } else {
 121         //         note_timbre = 0.45;
 122         //     }
 123         //     #define VOICE_VIBRATO_DELAY 150
 124         //     #define VOICE_VIBRATO_SPEED 50
 125         //     switch (compensated_index) {
 126         //         case 0 ... VOICE_VIBRATO_DELAY:
 127         //             break;
 128         //         default:
 129         //             frequency = frequency * VIBRATO_LUT[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1))/1000*VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)];
 130         //             break;
 131         //     }
 132         //     break;
 133         // case duty_fifth_down:
 134         //     note_timbre = 0.5;
 135         //     if ((envelope_index % 3) == 0)
 136         //         note_timbre = 0.75;
 137         //     break;
 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;
 144         //     break;
 145         // case duty_third_down:
 146         //     note_timbre = 0.5;
 147         //     if ((envelope_index % 5) == 0)
 148         //         note_timbre = 0.75;
 149         //     break;
 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;
 156         //     break;
 157
 158                 default:
 159                         break;
 160     }
 161
 162     return frequency;
 163 }
 164
 165