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