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- /* 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 <http://www.gnu.org/licenses/>.
- */
- #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;
- }
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