voices.c (12341B)
1 /* Copyright 2016 Jack Humbert 2 * Copyright 2020 JohSchneider 3 * 4 * This program is free software: you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation, either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program. If not, see <http://www.gnu.org/licenses/>. 16 */ 17 #include "voices.h" 18 #include "audio.h" 19 #include "timer.h" 20 #include <stdlib.h> 21 #include <math.h> 22 23 uint8_t note_timbre = TIMBRE_DEFAULT; 24 bool glissando = false; 25 bool vibrato = false; 26 float vibrato_strength = 0.5; 27 float vibrato_rate = 0.125; 28 29 uint16_t voices_timer = 0; 30 31 #ifdef AUDIO_VOICE_DEFAULT 32 voice_type voice = AUDIO_VOICE_DEFAULT; 33 #else 34 voice_type voice = default_voice; 35 #endif 36 37 void set_voice(voice_type v) { 38 voice = v; 39 } 40 41 void voice_iterate(void) { 42 voice = (voice + 1) % number_of_voices; 43 } 44 45 void voice_deiterate(void) { 46 voice = (voice - 1 + number_of_voices) % number_of_voices; 47 } 48 49 #ifdef AUDIO_VOICES 50 float mod(float a, int b) { 51 float r = fmod(a, b); 52 return r < 0 ? r + b : r; 53 } 54 55 // Effect: 'vibrate' a given target frequency slightly above/below its initial value 56 float voice_add_vibrato(float average_freq) { 57 float vibrato_counter = mod(timer_read() / (100 * vibrato_rate), VIBRATO_LUT_LENGTH); 58 59 return average_freq * pow(vibrato_lut[(int)vibrato_counter], vibrato_strength); 60 } 61 62 // Effect: 'slides' the 'frequency' from the starting-point, to the target frequency 63 float voice_add_glissando(float from_freq, float to_freq) { 64 if (to_freq != 0 && from_freq < to_freq && from_freq < to_freq * pow(2, -440 / to_freq / 12 / 2)) { 65 return from_freq * pow(2, 440 / from_freq / 12 / 2); 66 } else if (to_freq != 0 && from_freq > to_freq && from_freq > to_freq * pow(2, 440 / to_freq / 12 / 2)) { 67 return from_freq * pow(2, -440 / from_freq / 12 / 2); 68 } else { 69 return to_freq; 70 } 71 } 72 #endif 73 74 float voice_envelope(float frequency) { 75 // envelope_index ranges from 0 to 0xFFFF, which is preserved at 880.0 Hz 76 // __attribute__((unused)) uint16_t compensated_index = (uint16_t)((float)envelope_index * (880.0 / frequency)); 77 #ifdef AUDIO_VOICES 78 uint16_t envelope_index = timer_elapsed(voices_timer); // TODO: multiply in some factor? 79 uint16_t compensated_index = envelope_index / 100; // TODO: correct factor would be? 80 #endif 81 82 switch (voice) { 83 case default_voice: 84 glissando = false; 85 // note_timbre = TIMBRE_50; //Note: leave the user the possibility to adjust the timbre with 'audio_set_timbre' 86 break; 87 88 #ifdef AUDIO_VOICES 89 90 case vibrating: 91 glissando = false; 92 vibrato = true; 93 break; 94 95 case something: 96 glissando = false; 97 switch (compensated_index) { 98 case 0 ... 9: 99 note_timbre = TIMBRE_12; 100 break; 101 102 case 10 ... 19: 103 note_timbre = TIMBRE_25; 104 break; 105 106 case 20 ... 200: 107 note_timbre = 12 + 12; 108 break; 109 110 default: 111 note_timbre = 12; 112 break; 113 } 114 break; 115 116 case drums: 117 glissando = false; 118 // switch (compensated_index) { 119 // case 0 ... 10: 120 // note_timbre = 50; 121 // break; 122 // case 11 ... 20: 123 // note_timbre = 50 * (21 - compensated_index) / 10; 124 // break; 125 // default: 126 // note_timbre = 0; 127 // break; 128 // } 129 // frequency = (rand() % (int)(frequency * 1.2 - frequency)) + (frequency * 0.8); 130 131 if (frequency < 80.0) { 132 } else if (frequency < 160.0) { 133 // Bass drum: 60 - 100 Hz 134 frequency = (rand() % (int)(40)) + 60; 135 switch (envelope_index) { 136 case 0 ... 10: 137 note_timbre = 50; 138 break; 139 case 11 ... 20: 140 note_timbre = 50 * (21 - envelope_index) / 10; 141 break; 142 default: 143 note_timbre = 0; 144 break; 145 } 146 147 } else if (frequency < 320.0) { 148 // Snare drum: 1 - 2 KHz 149 frequency = (rand() % (int)(1000)) + 1000; 150 switch (envelope_index) { 151 case 0 ... 5: 152 note_timbre = 50; 153 break; 154 case 6 ... 20: 155 note_timbre = 50 * (21 - envelope_index) / 15; 156 break; 157 default: 158 note_timbre = 0; 159 break; 160 } 161 162 } else if (frequency < 640.0) { 163 // Closed Hi-hat: 3 - 5 KHz 164 frequency = (rand() % (int)(2000)) + 3000; 165 switch (envelope_index) { 166 case 0 ... 15: 167 note_timbre = 50; 168 break; 169 case 16 ... 20: 170 note_timbre = 50 * (21 - envelope_index) / 5; 171 break; 172 default: 173 note_timbre = 0; 174 break; 175 } 176 177 } else if (frequency < 1280.0) { 178 // Open Hi-hat: 3 - 5 KHz 179 frequency = (rand() % (int)(2000)) + 3000; 180 switch (envelope_index) { 181 case 0 ... 35: 182 note_timbre = 50; 183 break; 184 case 36 ... 50: 185 note_timbre = 50 * (51 - envelope_index) / 15; 186 break; 187 default: 188 note_timbre = 0; 189 break; 190 } 191 } 192 break; 193 case butts_fader: 194 glissando = true; 195 switch (compensated_index) { 196 case 0 ... 9: 197 frequency = frequency / 4; 198 note_timbre = TIMBRE_12; 199 break; 200 201 case 10 ... 19: 202 frequency = frequency / 2; 203 note_timbre = TIMBRE_12; 204 break; 205 206 case 20 ... 200: 207 note_timbre = 12 - (uint8_t)(pow(((float)compensated_index - 20) / (200 - 20), 2) * 12.5); 208 break; 209 210 default: 211 note_timbre = 0; 212 break; 213 } 214 break; 215 216 // case octave_crunch: 217 // switch (compensated_index) { 218 // case 0 ... 9: 219 // case 20 ... 24: 220 // case 30 ... 32: 221 // frequency = frequency / 2; 222 // note_timbre = TIMBRE_12; 223 // break; 224 225 // case 10 ... 19: 226 // case 25 ... 29: 227 // case 33 ... 35: 228 // frequency = frequency * 2; 229 // note_timbre = TIMBRE_12; 230 // break; 231 232 // default: 233 // note_timbre = TIMBRE_12; 234 // break; 235 // } 236 // break; 237 238 case duty_osc: 239 // This slows the loop down a substantial amount, so higher notes may freeze 240 glissando = true; 241 switch (compensated_index) { 242 default: 243 # define OCS_SPEED 10 244 # define OCS_AMP .25 245 // sine wave is slow 246 // note_timbre = (sin((float)compensated_index/10000*OCS_SPEED) * OCS_AMP / 2) + .5; 247 // triangle wave is a bit faster 248 note_timbre = (uint8_t)abs((compensated_index * OCS_SPEED % 3000) - 1500) * (OCS_AMP / 1500) + (1 - OCS_AMP) / 2; 249 break; 250 } 251 break; 252 253 case duty_octave_down: 254 glissando = true; 255 note_timbre = (uint8_t)(100 * (envelope_index % 2) * .125 + .375 * 2); 256 if ((envelope_index % 4) == 0) note_timbre = 50; 257 if ((envelope_index % 8) == 0) note_timbre = 0; 258 break; 259 case delayed_vibrato: 260 glissando = true; 261 note_timbre = TIMBRE_50; 262 # define VOICE_VIBRATO_DELAY 150 263 # define VOICE_VIBRATO_SPEED 50 264 switch (compensated_index) { 265 case 0 ... VOICE_VIBRATO_DELAY: 266 break; 267 default: 268 // TODO: merge/replace with voice_add_vibrato above 269 frequency = frequency * vibrato_lut[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1)) / 1000 * VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)]; 270 break; 271 } 272 break; 273 // case delayed_vibrato_octave: 274 // if ((envelope_index % 2) == 1) { 275 // note_timbre = 55; 276 // } else { 277 // note_timbre = 45; 278 // } 279 // #define VOICE_VIBRATO_DELAY 150 280 // #define VOICE_VIBRATO_SPEED 50 281 // switch (compensated_index) { 282 // case 0 ... VOICE_VIBRATO_DELAY: 283 // break; 284 // default: 285 // frequency = frequency * VIBRATO_LUT[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1))/1000*VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)]; 286 // break; 287 // } 288 // break; 289 // case duty_fifth_down: 290 // note_timbre = TIMBRE_50; 291 // if ((envelope_index % 3) == 0) 292 // note_timbre = TIMBRE_75; 293 // break; 294 // case duty_fourth_down: 295 // note_timbre = 0; 296 // if ((envelope_index % 12) == 0) 297 // note_timbre = TIMBRE_75; 298 // if (((envelope_index % 12) % 4) != 1) 299 // note_timbre = TIMBRE_75; 300 // break; 301 // case duty_third_down: 302 // note_timbre = TIMBRE_50; 303 // if ((envelope_index % 5) == 0) 304 // note_timbre = TIMBRE_75; 305 // break; 306 // case duty_fifth_third_down: 307 // note_timbre = TIMBRE_50; 308 // if ((envelope_index % 5) == 0) 309 // note_timbre = TIMBRE_75; 310 // if ((envelope_index % 3) == 0) 311 // note_timbre = TIMBRE_25; 312 // break; 313 314 #endif // AUDIO_VOICES 315 316 default: 317 break; 318 } 319 320 #ifdef AUDIO_VOICES 321 if (vibrato && (vibrato_strength > 0)) { 322 frequency = voice_add_vibrato(frequency); 323 } 324 325 if (glissando) { 326 // TODO: where to keep track of the start-frequency? 327 // frequency = voice_add_glissando(??, frequency); 328 } 329 #endif // AUDIO_VOICES 330 331 return frequency; 332 } 333 334 // Vibrato functions 335 336 void voice_set_vibrato_rate(float rate) { 337 vibrato_rate = rate; 338 } 339 void voice_increase_vibrato_rate(float change) { 340 vibrato_rate *= change; 341 } 342 void voice_decrease_vibrato_rate(float change) { 343 vibrato_rate /= change; 344 } 345 void voice_set_vibrato_strength(float strength) { 346 vibrato_strength = strength; 347 } 348 void voice_increase_vibrato_strength(float change) { 349 vibrato_strength *= change; 350 } 351 void voice_decrease_vibrato_strength(float change) { 352 vibrato_strength /= change; 353 } 354 355 // Timbre functions 356 357 void voice_set_timbre(uint8_t timbre) { 358 if ((timbre > 0) && (timbre < 100)) { 359 note_timbre = timbre; 360 } 361 } 362 uint8_t voice_get_timbre(void) { 363 return note_timbre; 364 }