/* Copyright 2016 Jack Humbert * * 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 . */ #include "voices.h" #include "audio.h" #include "stdlib.h" // these are imported from audio.c extern uint16_t envelope_index; extern float note_timbre; extern float polyphony_rate; extern bool glissando; voice_type voice = default_voice; 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; } 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)); switch (voice) { case default_voice: glissando = false; note_timbre = TIMBRE_50; polyphony_rate = 0; break; #ifdef AUDIO_VOICES case something: glissando = false; polyphony_rate = 0; switch (compensated_index) { case 0 ... 9: note_timbre = TIMBRE_12; break; case 10 ... 19: note_timbre = TIMBRE_25; break; case 20 ... 200: note_timbre = .125 + .125; break; default: note_timbre = .125; break; } break; case drums: glissando = false; polyphony_rate = 0; // switch (compensated_index) { // case 0 ... 10: // note_timbre = 0.5; // break; // case 11 ... 20: // note_timbre = 0.5 * (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 = 0.5; break; case 11 ... 20: note_timbre = 0.5 * (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 = 0.5; break; case 6 ... 20: note_timbre = 0.5 * (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 = 0.5; break; case 16 ... 20: note_timbre = 0.5 * (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 = 0.5; break; case 36 ... 50: note_timbre = 0.5 * (51 - envelope_index) / 15; break; default: note_timbre = 0; break; } } break; case butts_fader: glissando = true; polyphony_rate = 0; 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 = .125 - pow(((float)compensated_index - 20) / (200 - 20), 2)*.125; break; default: note_timbre = 0; break; } break; // case octave_crunch: // polyphony_rate = 0; // 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; polyphony_rate = 0; 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 = (float)abs((compensated_index*OCS_SPEED % 3000) - 1500) * ( OCS_AMP / 1500 ) + (1 - OCS_AMP) / 2; break; } break; case duty_octave_down: glissando = true; polyphony_rate = 0; note_timbre = (envelope_index % 2) * .125 + .375 * 2; if ((envelope_index % 4) == 0) note_timbre = 0.5; if ((envelope_index % 8) == 0) note_timbre = 0; break; case delayed_vibrato: glissando = true; polyphony_rate = 0; note_timbre = TIMBRE_50; #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 delayed_vibrato_octave: // polyphony_rate = 0; // if ((envelope_index % 2) == 1) { // note_timbre = 0.55; // } else { // note_timbre = 0.45; // } // #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 = 0.5; // if ((envelope_index % 3) == 0) // note_timbre = 0.75; // break; // case duty_fourth_down: // note_timbre = 0.0; // if ((envelope_index % 12) == 0) // note_timbre = 0.75; // if (((envelope_index % 12) % 4) != 1) // note_timbre = 0.75; // break; // case duty_third_down: // note_timbre = 0.5; // if ((envelope_index % 5) == 0) // note_timbre = 0.75; // break; // case duty_fifth_third_down: // note_timbre = 0.5; // if ((envelope_index % 5) == 0) // note_timbre = 0.75; // if ((envelope_index % 3) == 0) // note_timbre = 0.25; // break; #endif default: break; } return frequency; }