quantum/audio/audio.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 //#include <math.h>
   4 #include <avr/pgmspace.h>
   5 #include <avr/interrupt.h>
   6 #include <avr/io.h>
   7 #include "print.h"
   8 #include "audio.h"
   9 #include "keymap.h"
  10
  11 #include "eeconfig.h"
  12
  13 #define CPU_PRESCALER 8
  14
  15 // -----------------------------------------------------------------------------
  16 // Timer Abstractions
  17 // -----------------------------------------------------------------------------
  18
  19 // TIMSK3 - Timer/Counter #3 Interrupt Mask Register
  20 // Turn on/off 3A interputs, stopping/enabling the ISR calls
  21 #define ENABLE_AUDIO_COUNTER_3_ISR TIMSK3 |= _BV(OCIE3A)
  22 #define DISABLE_AUDIO_COUNTER_3_ISR TIMSK3 &= ~_BV(OCIE3A)
  23
  24 // TCCR3A: Timer/Counter #3 Control Register
  25 // Compare Output Mode (COM3An) = 0b00 = Normal port operation, OC3A disconnected from PC6
  26 #define ENABLE_AUDIO_COUNTER_3_OUTPUT TCCR3A |= _BV(COM3A1);
  27 #define DISABLE_AUDIO_COUNTER_3_OUTPUT TCCR3A &= ~(_BV(COM3A1) | _BV(COM3A0));
  28
  29 // Fast PWM Mode Controls
  30 #define TIMER_3_PERIOD     ICR3
  31 #define TIMER_3_DUTY_CYCLE OCR3A
  32
  33 // -----------------------------------------------------------------------------
  34
  35
  36 int voices = 0;
  37 int voice_place = 0;
  38 float frequency = 0;
  39 int volume = 0;
  40 long position = 0;
  41
  42 float frequencies[8] = {0, 0, 0, 0, 0, 0, 0, 0};
  43 int volumes[8] = {0, 0, 0, 0, 0, 0, 0, 0};
  44 bool sliding = false;
  45
  46 float place = 0;
  47
  48 uint8_t * sample;
  49 uint16_t sample_length = 0;
  50
  51 bool     playing_notes = false;
  52 bool     playing_note = false;
  53 float    note_frequency = 0;
  54 float    note_length = 0;
  55 uint8_t  note_tempo = TEMPO_DEFAULT;
  56 float    note_timbre = TIMBRE_DEFAULT;
  57 uint16_t note_position = 0;
  58 float (* notes_pointer)[][2];
  59 uint16_t notes_count;
  60 bool     notes_repeat;
  61 float    notes_rest;
  62 bool     note_resting = false;
  63
  64 uint8_t current_note = 0;
  65 uint8_t rest_counter = 0;
  66
  67 #ifdef VIBRATO_ENABLE
  68 float vibrato_counter = 0;
  69 float vibrato_strength = .5;
  70 float vibrato_rate = 0.125;
  71 #endif
  72
  73 float polyphony_rate = 0;
  74
  75 static bool audio_initialized = false;
  76
  77 audio_config_t audio_config;
  78
  79 uint16_t envelope_index = 0;
  80 bool glissando = true;
  81
  82 void audio_init()
  83 {
  84
  85     // Check EEPROM
  86     if (!eeconfig_is_enabled())
  87     {
  88         eeconfig_init();
  89     }
  90     audio_config.raw = eeconfig_read_audio();
  91
  92         // Set port PC6 (OC3A and /OC4A) as output
  93     DDRC |= _BV(PORTC6);
  94
  95     DISABLE_AUDIO_COUNTER_3_ISR;
  96
  97         // TCCR3A / TCCR3B: Timer/Counter #3 Control Registers
  98         // Compare Output Mode (COM3An) = 0b00 = Normal port operation, OC3A disconnected from PC6
  99         // Waveform Generation Mode (WGM3n) = 0b1110 = Fast PWM Mode 14 (Period = ICR3, Duty Cycle = OCR3A)
 100         // Clock Select (CS3n) = 0b010 = Clock / 8
 101     TCCR3A = (0 << COM3A1) | (0 << COM3A0) | (1 << WGM31) | (0 << WGM30);
 102     TCCR3B = (1 << WGM33)  | (1 << WGM32)  | (0 << CS32)  | (1 << CS31) | (0 << CS30);
 103
 104     audio_initialized = true;
 105 }
 106
 107 void stop_all_notes()
 108 {
 109     if (!audio_initialized) {
 110         audio_init();
 111     }
 112     voices = 0;
 113
 114     DISABLE_AUDIO_COUNTER_3_ISR;
 115     DISABLE_AUDIO_COUNTER_3_OUTPUT;
 116
 117     playing_notes = false;
 118     playing_note = false;
 119     frequency = 0;
 120     volume = 0;
 121
 122     for (uint8_t i = 0; i < 8; i++)
 123     {
 124         frequencies[i] = 0;
 125         volumes[i] = 0;
 126     }
 127 }
 128
 129 void stop_note(float freq)
 130 {
 131     if (playing_note) {
 132         if (!audio_initialized) {
 133             audio_init();
 134         }
 135         for (int i = 7; i >= 0; i--) {
 136             if (frequencies[i] == freq) {
 137                 frequencies[i] = 0;
 138                 volumes[i] = 0;
 139                 for (int j = i; (j < 7); j++) {
 140                     frequencies[j] = frequencies[j+1];
 141                     frequencies[j+1] = 0;
 142                     volumes[j] = volumes[j+1];
 143                     volumes[j+1] = 0;
 144                 }
 145                 break;
 146             }
 147         }
 148         voices--;
 149         if (voices < 0)
 150             voices = 0;
 151         if (voice_place >= voices) {
 152             voice_place = 0;
 153         }
 154         if (voices == 0) {
 155             DISABLE_AUDIO_COUNTER_3_ISR;
 156             DISABLE_AUDIO_COUNTER_3_OUTPUT;
 157             frequency = 0;
 158             volume = 0;
 159             playing_note = false;
 160         }
 161     }
 162 }
 163
 164 #ifdef VIBRATO_ENABLE
 165
 166 float mod(float a, int b)
 167 {
 168     float r = fmod(a, b);
 169     return r < 0 ? r + b : r;
 170 }
 171
 172 float vibrato(float average_freq) {
 173     #ifdef VIBRATO_STRENGTH_ENABLE
 174         float vibrated_freq = average_freq * pow(vibrato_lut[(int)vibrato_counter], vibrato_strength);
 175     #else
 176         float vibrated_freq = average_freq * vibrato_lut[(int)vibrato_counter];
 177     #endif
 178     vibrato_counter = mod((vibrato_counter + vibrato_rate * (1.0 + 440.0/average_freq)), VIBRATO_LUT_LENGTH);
 179     return vibrated_freq;
 180 }
 181
 182 #endif
 183
 184 ISR(TIMER3_COMPA_vect)
 185 {
 186         float freq;
 187
 188         if (playing_note) {
 189                 if (voices > 0) {
 190                         if (polyphony_rate > 0) {
 191                                 if (voices > 1) {
 192                                         voice_place %= voices;
 193                                         if (place++ > (frequencies[voice_place] / polyphony_rate / CPU_PRESCALER)) {
 194                                                 voice_place = (voice_place + 1) % voices;
 195                                                 place = 0.0;
 196                                         }
 197                                 }
 198
 199                                 #ifdef VIBRATO_ENABLE
 200                                         if (vibrato_strength > 0) {
 201                                                 freq = vibrato(frequencies[voice_place]);
 202                                         } else {
 203                                                 freq = frequencies[voice_place];
 204                                         }
 205                                 #else
 206                                         freq = frequencies[voice_place];
 207                                 #endif
 208                         } else {
 209                                 if (glissando) {
 210                                         if (frequency != 0 && frequency < frequencies[voices - 1] && frequency < frequencies[voices - 1] * pow(2, -440/frequencies[voices - 1]/12/2)) {
 211                                                 frequency = frequency * pow(2, 440/frequency/12/2);
 212                                         } else if (frequency != 0 && frequency > frequencies[voices - 1] && frequency > frequencies[voices - 1] * pow(2, 440/frequencies[voices - 1]/12/2)) {
 213                                                 frequency = frequency * pow(2, -440/frequency/12/2);
 214                                         } else {
 215                                                 frequency = frequencies[voices - 1];
 216                                         }
 217                                 } else {
 218                                         frequency = frequencies[voices - 1];
 219                                 }
 220
 221                                 #ifdef VIBRATO_ENABLE
 222                                         if (vibrato_strength > 0) {
 223                                                 freq = vibrato(frequency);
 224                                         } else {
 225                                                 freq = frequency;
 226                                         }
 227                                 #else
 228                                         freq = frequency;
 229                                 #endif
 230                         }
 231
 232                         if (envelope_index < 65535) {
 233                                 envelope_index++;
 234                         }
 235
 236                         freq = voice_envelope(freq);
 237
 238                         if (freq < 30.517578125) {
 239                                 freq = 30.52;
 240                         }
 241
 242                         TIMER_3_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
 243                         TIMER_3_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
 244                 }
 245         }
 246
 247         if (playing_notes) {
 248                 if (note_frequency > 0) {
 249                         #ifdef VIBRATO_ENABLE
 250                                 if (vibrato_strength > 0) {
 251                                         freq = vibrato(note_frequency);
 252                                 } else {
 253                                         freq = note_frequency;
 254                                 }
 255                         #else
 256                                         freq = note_frequency;
 257                         #endif
 258
 259                         if (envelope_index < 65535) {
 260                                 envelope_index++;
 261                         }
 262                         freq = voice_envelope(freq);
 263
 264                         TIMER_3_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
 265                         TIMER_3_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
 266                 } else {
 267                         TIMER_3_PERIOD = 0;
 268                         TIMER_3_DUTY_CYCLE = 0;
 269                 }
 270
 271                 note_position++;
 272                 bool end_of_note = false;
 273                 if (TIMER_3_PERIOD > 0) {
 274                         end_of_note = (note_position >= (note_length / TIMER_3_PERIOD * 0xFFFF));
 275                 } else {
 276                         end_of_note = (note_position >= (note_length * 0x7FF));
 277                 }
 278
 279                 if (end_of_note) {
 280                         current_note++;
 281                         if (current_note >= notes_count) {
 282                                 if (notes_repeat) {
 283                                         current_note = 0;
 284                                 } else {
 285                                         DISABLE_AUDIO_COUNTER_3_ISR;
 286                                         DISABLE_AUDIO_COUNTER_3_OUTPUT;
 287                                         playing_notes = false;
 288                                         return;
 289                                 }
 290                         }
 291                         if (!note_resting && (notes_rest > 0)) {
 292                                 note_resting = true;
 293                                 note_frequency = 0;
 294                                 note_length = notes_rest;
 295                                 current_note--;
 296                         } else {
 297                                 note_resting = false;
 298                                 envelope_index = 0;
 299                                 note_frequency = (*notes_pointer)[current_note][0];
 300                                 note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
 301                         }
 302
 303                         note_position = 0;
 304                 }
 305         }
 306
 307         if (!audio_config.enable) {
 308                 playing_notes = false;
 309                 playing_note = false;
 310         }
 311 }
 312
 313 void play_note(float freq, int vol) {
 314
 315     if (!audio_initialized) {
 316         audio_init();
 317     }
 318
 319         if (audio_config.enable && voices < 8) {
 320             DISABLE_AUDIO_COUNTER_3_ISR;
 321
 322             // Cancel notes if notes are playing
 323             if (playing_notes)
 324                 stop_all_notes();
 325
 326             playing_note = true;
 327
 328             envelope_index = 0;
 329
 330             if (freq > 0) {
 331                 frequencies[voices] = freq;
 332                 volumes[voices] = vol;
 333                 voices++;
 334             }
 335
 336         ENABLE_AUDIO_COUNTER_3_ISR;
 337         ENABLE_AUDIO_COUNTER_3_OUTPUT;
 338         }
 339
 340 }
 341
 342 void play_notes(float (*np)[][2], uint16_t n_count, bool n_repeat, float n_rest)
 343 {
 344
 345     if (!audio_initialized) {
 346         audio_init();
 347     }
 348
 349         if (audio_config.enable) {
 350
 351             DISABLE_AUDIO_COUNTER_3_ISR;
 352
 353                 // Cancel note if a note is playing
 354             if (playing_note)
 355                 stop_all_notes();
 356
 357             playing_notes = true;
 358
 359             notes_pointer = np;
 360             notes_count = n_count;
 361             notes_repeat = n_repeat;
 362             notes_rest = n_rest;
 363
 364             place = 0;
 365             current_note = 0;
 366
 367         note_frequency = (*notes_pointer)[current_note][0];
 368         note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
 369             note_position = 0;
 370
 371
 372         ENABLE_AUDIO_COUNTER_3_ISR;
 373         ENABLE_AUDIO_COUNTER_3_OUTPUT;
 374         }
 375
 376 }
 377
 378 bool is_playing_notes(void) {
 379         return playing_notes;
 380 }
 381
 382 bool is_audio_on(void) {
 383     return (audio_config.enable != 0);
 384 }
 385
 386 void audio_toggle(void) {
 387     audio_config.enable ^= 1;
 388     eeconfig_update_audio(audio_config.raw);
 389     if (audio_config.enable)
 390         audio_on_user();
 391 }
 392
 393 void audio_on(void) {
 394     audio_config.enable = 1;
 395     eeconfig_update_audio(audio_config.raw);
 396     audio_on_user();
 397 }
 398
 399 void audio_off(void) {
 400     audio_config.enable = 0;
 401     eeconfig_update_audio(audio_config.raw);
 402 }
 403
 404 #ifdef VIBRATO_ENABLE
 405
 406 // Vibrato rate functions
 407
 408 void set_vibrato_rate(float rate) {
 409     vibrato_rate = rate;
 410 }
 411
 412 void increase_vibrato_rate(float change) {
 413     vibrato_rate *= change;
 414 }
 415
 416 void decrease_vibrato_rate(float change) {
 417     vibrato_rate /= change;
 418 }
 419
 420 #ifdef VIBRATO_STRENGTH_ENABLE
 421
 422 void set_vibrato_strength(float strength) {
 423     vibrato_strength = strength;
 424 }
 425
 426 void increase_vibrato_strength(float change) {
 427     vibrato_strength *= change;
 428 }
 429
 430 void decrease_vibrato_strength(float change) {
 431     vibrato_strength /= change;
 432 }
 433
 434 #endif  /* VIBRATO_STRENGTH_ENABLE */
 435
 436 #endif /* VIBRATO_ENABLE */
 437
 438 // Polyphony functions
 439
 440 void set_polyphony_rate(float rate) {
 441     polyphony_rate = rate;
 442 }
 443
 444 void enable_polyphony() {
 445     polyphony_rate = 5;
 446 }
 447
 448 void disable_polyphony() {
 449     polyphony_rate = 0;
 450 }
 451
 452 void increase_polyphony_rate(float change) {
 453     polyphony_rate *= change;
 454 }
 455
 456 void decrease_polyphony_rate(float change) {
 457     polyphony_rate /= change;
 458 }
 459
 460 // Timbre function
 461
 462 void set_timbre(float timbre) {
 463     note_timbre = timbre;
 464 }
 465
 466 // Tempo functions
 467
 468 void set_tempo(uint8_t tempo) {
 469     note_tempo = tempo;
 470 }
 471
 472 void decrease_tempo(uint8_t tempo_change) {
 473     note_tempo += tempo_change;
 474 }
 475
 476 void increase_tempo(uint8_t tempo_change) {
 477     if (note_tempo - tempo_change < 10) {
 478         note_tempo = 10;
 479     } else {
 480         note_tempo -= tempo_change;
 481     }
 482 }