/* Copyright 2016 Jack Humbert * Copyright 2020 JohSchneider * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "voices.h" #include "audio.h" #include <stdlib.h> uint8_t note_timbre = TIMBRE_DEFAULT; bool glissando = false; bool vibrato = false; float vibrato_strength = 0.5; float vibrato_rate = 0.125; uint16_t voices_timer = 0; #ifdef AUDIO_VOICE_DEFAULT voice_type voice = AUDIO_VOICE_DEFAULT; #else voice_type voice = default_voice; #endif void set_voice(voice_type v) { voice = v; } void voice_iterate() { voice = (voice + 1) % number_of_voices; } void voice_deiterate() { voice = (voice - 1 + number_of_voices) % number_of_voices; } #ifdef AUDIO_VOICES float mod(float a, int b) { float r = fmod(a, b); return r < 0 ? r + b : r; } // Effect: 'vibrate' a given target frequency slightly above/below its initial value float voice_add_vibrato(float average_freq) { float vibrato_counter = mod(timer_read() / (100 * vibrato_rate), VIBRATO_LUT_LENGTH); return average_freq * pow(vibrato_lut[(int)vibrato_counter], vibrato_strength); } // Effect: 'slides' the 'frequency' from the starting-point, to the target frequency float voice_add_glissando(float from_freq, float to_freq) { if (to_freq != 0 && from_freq < to_freq && from_freq < to_freq * pow(2, -440 / to_freq / 12 / 2)) { return from_freq * pow(2, 440 / from_freq / 12 / 2); } else if (to_freq != 0 && from_freq > to_freq && from_freq > to_freq * pow(2, 440 / to_freq / 12 / 2)) { return from_freq * pow(2, -440 / from_freq / 12 / 2); } else { return to_freq; } } #endif float voice_envelope(float frequency) { // envelope_index ranges from 0 to 0xFFFF, which is preserved at 880.0 Hz // __attribute__((unused)) uint16_t compensated_index = (uint16_t)((float)envelope_index * (880.0 / frequency)); #ifdef AUDIO_VOICES uint16_t envelope_index = timer_elapsed(voices_timer); // TODO: multiply in some factor? uint16_t compensated_index = envelope_index / 100; // TODO: correct factor would be? #endif switch (voice) { case default_voice: glissando = false; // note_timbre = TIMBRE_50; //Note: leave the user the possibility to adjust the timbre with 'audio_set_timbre' break; #ifdef AUDIO_VOICES case vibrating: glissando = false; vibrato = true; break; case something: glissando = false; switch (compensated_index) { case 0 ... 9: note_timbre = TIMBRE_12; break; case 10 ... 19: note_timbre = TIMBRE_25; break; case 20 ... 200: note_timbre = 12 + 12; break; default: note_timbre = 12; break; } break; case drums: glissando = false; // switch (compensated_index) { // case 0 ... 10: // note_timbre = 50; // break; // case 11 ... 20: // note_timbre = 50 * (21 - compensated_index) / 10; // break; // default: // note_timbre = 0; // break; // } // frequency = (rand() % (int)(frequency * 1.2 - frequency)) + (frequency * 0.8); if (frequency < 80.0) { } else if (frequency < 160.0) { // Bass drum: 60 - 100 Hz frequency = (rand() % (int)(40)) + 60; switch (envelope_index) { case 0 ... 10: note_timbre = 50; break; case 11 ... 20: note_timbre = 50 * (21 - envelope_index) / 10; break; default: note_timbre = 0; break; } } else if (frequency < 320.0) { // Snare drum: 1 - 2 KHz frequency = (rand() % (int)(1000)) + 1000; switch (envelope_index) { case 0 ... 5: note_timbre = 50; break; case 6 ... 20: note_timbre = 50 * (21 - envelope_index) / 15; break; default: note_timbre = 0; break; } } else if (frequency < 640.0) { // Closed Hi-hat: 3 - 5 KHz frequency = (rand() % (int)(2000)) + 3000; switch (envelope_index) { case 0 ... 15: note_timbre = 50; break; case 16 ... 20: note_timbre = 50 * (21 - envelope_index) / 5; break; default: note_timbre = 0; break; } } else if (frequency < 1280.0) { // Open Hi-hat: 3 - 5 KHz frequency = (rand() % (int)(2000)) + 3000; switch (envelope_index) { case 0 ... 35: note_timbre = 50; break; case 36 ... 50: note_timbre = 50 * (51 - envelope_index) / 15; break; default: note_timbre = 0; break; } } break; case butts_fader: glissando = true; switch (compensated_index) { case 0 ... 9: frequency = frequency / 4; note_timbre = TIMBRE_12; break; case 10 ... 19: frequency = frequency / 2; note_timbre = TIMBRE_12; break; case 20 ... 200: note_timbre = 12 - (uint8_t)(pow(((float)compensated_index - 20) / (200 - 20), 2) * 12.5); break; default: note_timbre = 0; break; } break; // case octave_crunch: // switch (compensated_index) { // case 0 ... 9: // case 20 ... 24: // case 30 ... 32: // frequency = frequency / 2; // note_timbre = TIMBRE_12; // break; // case 10 ... 19: // case 25 ... 29: // case 33 ... 35: // frequency = frequency * 2; // note_timbre = TIMBRE_12; // break; // default: // note_timbre = TIMBRE_12; // break; // } // break; case duty_osc: // This slows the loop down a substantial amount, so higher notes may freeze glissando = true; switch (compensated_index) { default: # define OCS_SPEED 10 # define OCS_AMP .25 // sine wave is slow // note_timbre = (sin((float)compensated_index/10000*OCS_SPEED) * OCS_AMP / 2) + .5; // triangle wave is a bit faster note_timbre = (uint8_t)abs((compensated_index * OCS_SPEED % 3000) - 1500) * (OCS_AMP / 1500) + (1 - OCS_AMP) / 2; break; } break; case duty_octave_down: glissando = true; note_timbre = (uint8_t)(100 * (envelope_index % 2) * .125 + .375 * 2); if ((envelope_index % 4) == 0) note_timbre = 50; if ((envelope_index % 8) == 0) note_timbre = 0; break; case delayed_vibrato: glissando = true; note_timbre = TIMBRE_50; # define VOICE_VIBRATO_DELAY 150 # define VOICE_VIBRATO_SPEED 50 switch (compensated_index) { case 0 ... VOICE_VIBRATO_DELAY: break; default: // TODO: merge/replace with voice_add_vibrato above frequency = frequency * vibrato_lut[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1)) / 1000 * VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)]; break; } break; // case delayed_vibrato_octave: // if ((envelope_index % 2) == 1) { // note_timbre = 55; // } else { // note_timbre = 45; // } // #define VOICE_VIBRATO_DELAY 150 // #define VOICE_VIBRATO_SPEED 50 // switch (compensated_index) { // case 0 ... VOICE_VIBRATO_DELAY: // break; // default: // frequency = frequency * VIBRATO_LUT[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1))/1000*VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)]; // break; // } // break; // case duty_fifth_down: // note_timbre = TIMBRE_50; // if ((envelope_index % 3) == 0) // note_timbre = TIMBRE_75; // break; // case duty_fourth_down: // note_timbre = 0; // if ((envelope_index % 12) == 0) // note_timbre = TIMBRE_75; // if (((envelope_index % 12) % 4) != 1) // note_timbre = TIMBRE_75; // break; // case duty_third_down: // note_timbre = TIMBRE_50; // if ((envelope_index % 5) == 0) // note_timbre = TIMBRE_75; // break; // case duty_fifth_third_down: // note_timbre = TIMBRE_50; // if ((envelope_index % 5) == 0) // note_timbre = TIMBRE_75; // if ((envelope_index % 3) == 0) // note_timbre = TIMBRE_25; // break; #endif // AUDIO_VOICES default: break; } #ifdef AUDIO_VOICES if (vibrato && (vibrato_strength > 0)) { frequency = voice_add_vibrato(frequency); } if (glissando) { // TODO: where to keep track of the start-frequency? // frequency = voice_add_glissando(??, frequency); } #endif // AUDIO_VOICES return frequency; } // Vibrato functions void voice_set_vibrato_rate(float rate) { vibrato_rate = rate; } void voice_increase_vibrato_rate(float change) { vibrato_rate *= change; } void voice_decrease_vibrato_rate(float change) { vibrato_rate /= change; } void voice_set_vibrato_strength(float strength) { vibrato_strength = strength; } void voice_increase_vibrato_strength(float change) { vibrato_strength *= change; } void voice_decrease_vibrato_strength(float change) { vibrato_strength /= change; } // Timbre functions void voice_set_timbre(uint8_t timbre) { if ((timbre > 0) && (timbre < 100)) { note_timbre = timbre; } } uint8_t voice_get_timbre(void) { return note_timbre; }