/* 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 <stdio.h> #include <string.h> //#include <math.h> #include <avr/pgmspace.h> #include <avr/interrupt.h> #include <avr/io.h> #include "print.h" #include "audio.h" #include "keymap.h" #include "eeconfig.h" #define CPU_PRESCALER 8 // ----------------------------------------------------------------------------- // Timer Abstractions // ----------------------------------------------------------------------------- // TIMSK3 - Timer/Counter #3 Interrupt Mask Register // Turn on/off 3A interputs, stopping/enabling the ISR calls #define ENABLE_AUDIO_COUNTER_3_ISR TIMSK3 |= _BV(OCIE3A) #define DISABLE_AUDIO_COUNTER_3_ISR TIMSK3 &= ~_BV(OCIE3A) // TCCR3A: Timer/Counter #3 Control Register // Compare Output Mode (COM3An) = 0b00 = Normal port operation, OC3A disconnected from PC6 #define ENABLE_AUDIO_COUNTER_3_OUTPUT TCCR3A |= _BV(COM3A1); #define DISABLE_AUDIO_COUNTER_3_OUTPUT TCCR3A &= ~(_BV(COM3A1) | _BV(COM3A0)); // Fast PWM Mode Controls #define TIMER_3_PERIOD ICR3 #define TIMER_3_DUTY_CYCLE OCR3A // ----------------------------------------------------------------------------- int voices = 0; int voice_place = 0; float frequency = 0; int volume = 0; long position = 0; float frequencies[8] = {0, 0, 0, 0, 0, 0, 0, 0}; int volumes[8] = {0, 0, 0, 0, 0, 0, 0, 0}; bool sliding = false; float place = 0; uint8_t * sample; uint16_t sample_length = 0; bool playing_notes = false; bool playing_note = false; float note_frequency = 0; float note_length = 0; uint8_t note_tempo = TEMPO_DEFAULT; float note_timbre = TIMBRE_DEFAULT; uint16_t note_position = 0; float (* notes_pointer)[][2]; uint16_t notes_count; bool notes_repeat; float notes_rest; bool note_resting = false; uint8_t current_note = 0; uint8_t rest_counter = 0; #ifdef VIBRATO_ENABLE float vibrato_counter = 0; float vibrato_strength = .5; float vibrato_rate = 0.125; #endif float polyphony_rate = 0; static bool audio_initialized = false; audio_config_t audio_config; uint16_t envelope_index = 0; bool glissando = true; void audio_init() { // Check EEPROM if (!eeconfig_is_enabled()) { eeconfig_init(); } audio_config.raw = eeconfig_read_audio(); // Set port PC6 (OC3A and /OC4A) as output DDRC |= _BV(PORTC6); DISABLE_AUDIO_COUNTER_3_ISR; // TCCR3A / TCCR3B: Timer/Counter #3 Control Registers // Compare Output Mode (COM3An) = 0b00 = Normal port operation, OC3A disconnected from PC6 // Waveform Generation Mode (WGM3n) = 0b1110 = Fast PWM Mode 14 (Period = ICR3, Duty Cycle = OCR3A) // Clock Select (CS3n) = 0b010 = Clock / 8 TCCR3A = (0 << COM3A1) | (0 << COM3A0) | (1 << WGM31) | (0 << WGM30); TCCR3B = (1 << WGM33) | (1 << WGM32) | (0 << CS32) | (1 << CS31) | (0 << CS30); audio_initialized = true; } void stop_all_notes() { dprintf("audio stop all notes"); if (!audio_initialized) { audio_init(); } voices = 0; DISABLE_AUDIO_COUNTER_3_ISR; DISABLE_AUDIO_COUNTER_3_OUTPUT; playing_notes = false; playing_note = false; frequency = 0; volume = 0; for (uint8_t i = 0; i < 8; i++) { frequencies[i] = 0; volumes[i] = 0; } } void stop_note(float freq) { dprintf("audio stop note freq=%d", (int)freq); if (playing_note) { if (!audio_initialized) { audio_init(); } for (int i = 7; i >= 0; i--) { if (frequencies[i] == freq) { frequencies[i] = 0; volumes[i] = 0; for (int j = i; (j < 7); j++) { frequencies[j] = frequencies[j+1]; frequencies[j+1] = 0; volumes[j] = volumes[j+1]; volumes[j+1] = 0; } break; } } voices--; if (voices < 0) voices = 0; if (voice_place >= voices) { voice_place = 0; } if (voices == 0) { DISABLE_AUDIO_COUNTER_3_ISR; DISABLE_AUDIO_COUNTER_3_OUTPUT; frequency = 0; volume = 0; playing_note = false; } } } #ifdef VIBRATO_ENABLE float mod(float a, int b) { float r = fmod(a, b); return r < 0 ? r + b : r; } float vibrato(float average_freq) { #ifdef VIBRATO_STRENGTH_ENABLE float vibrated_freq = average_freq * pow(vibrato_lut[(int)vibrato_counter], vibrato_strength); #else float vibrated_freq = average_freq * vibrato_lut[(int)vibrato_counter]; #endif vibrato_counter = mod((vibrato_counter + vibrato_rate * (1.0 + 440.0/average_freq)), VIBRATO_LUT_LENGTH); return vibrated_freq; } #endif ISR(TIMER3_COMPA_vect) { float freq; if (playing_note) { if (voices > 0) { if (polyphony_rate > 0) { if (voices > 1) { voice_place %= voices; if (place++ > (frequencies[voice_place] / polyphony_rate / CPU_PRESCALER)) { voice_place = (voice_place + 1) % voices; place = 0.0; } } #ifdef VIBRATO_ENABLE if (vibrato_strength > 0) { freq = vibrato(frequencies[voice_place]); } else { freq = frequencies[voice_place]; } #else freq = frequencies[voice_place]; #endif } else { if (glissando) { if (frequency != 0 && frequency < frequencies[voices - 1] && frequency < frequencies[voices - 1] * pow(2, -440/frequencies[voices - 1]/12/2)) { frequency = frequency * pow(2, 440/frequency/12/2); } else if (frequency != 0 && frequency > frequencies[voices - 1] && frequency > frequencies[voices - 1] * pow(2, 440/frequencies[voices - 1]/12/2)) { frequency = frequency * pow(2, -440/frequency/12/2); } else { frequency = frequencies[voices - 1]; } } else { frequency = frequencies[voices - 1]; } #ifdef VIBRATO_ENABLE if (vibrato_strength > 0) { freq = vibrato(frequency); } else { freq = frequency; } #else freq = frequency; #endif } if (envelope_index < 65535) { envelope_index++; } freq = voice_envelope(freq); if (freq < 30.517578125) { freq = 30.52; } TIMER_3_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER)); TIMER_3_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre); } } if (playing_notes) { if (note_frequency > 0) { #ifdef VIBRATO_ENABLE if (vibrato_strength > 0) { freq = vibrato(note_frequency); } else { freq = note_frequency; } #else freq = note_frequency; #endif if (envelope_index < 65535) { envelope_index++; } freq = voice_envelope(freq); TIMER_3_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER)); TIMER_3_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre); } else { TIMER_3_PERIOD = 0; TIMER_3_DUTY_CYCLE = 0; } note_position++; bool end_of_note = false; if (TIMER_3_PERIOD > 0) { end_of_note = (note_position >= (note_length / TIMER_3_PERIOD * 0xFFFF)); } else { end_of_note = (note_position >= (note_length * 0x7FF)); } if (end_of_note) { current_note++; if (current_note >= notes_count) { if (notes_repeat) { current_note = 0; } else { DISABLE_AUDIO_COUNTER_3_ISR; DISABLE_AUDIO_COUNTER_3_OUTPUT; playing_notes = false; return; } } if (!note_resting && (notes_rest > 0)) { note_resting = true; note_frequency = 0; note_length = notes_rest; current_note--; } else { note_resting = false; envelope_index = 0; note_frequency = (*notes_pointer)[current_note][0]; note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100); } note_position = 0; } } if (!audio_config.enable) { playing_notes = false; playing_note = false; } } void play_note(float freq, int vol) { dprintf("audio play note freq=%d vol=%d", (int)freq, vol); if (!audio_initialized) { audio_init(); } if (audio_config.enable && voices < 8) { DISABLE_AUDIO_COUNTER_3_ISR; // Cancel notes if notes are playing if (playing_notes) stop_all_notes(); playing_note = true; envelope_index = 0; if (freq > 0) { frequencies[voices] = freq; volumes[voices] = vol; voices++; } ENABLE_AUDIO_COUNTER_3_ISR; ENABLE_AUDIO_COUNTER_3_OUTPUT; } } void play_notes(float (*np)[][2], uint16_t n_count, bool n_repeat, float n_rest) { if (!audio_initialized) { audio_init(); } if (audio_config.enable) { DISABLE_AUDIO_COUNTER_3_ISR; // Cancel note if a note is playing if (playing_note) stop_all_notes(); playing_notes = true; notes_pointer = np; notes_count = n_count; notes_repeat = n_repeat; notes_rest = n_rest; place = 0; current_note = 0; note_frequency = (*notes_pointer)[current_note][0]; note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100); note_position = 0; ENABLE_AUDIO_COUNTER_3_ISR; ENABLE_AUDIO_COUNTER_3_OUTPUT; } } bool is_playing_notes(void) { return playing_notes; } bool is_audio_on(void) { return (audio_config.enable != 0); } void audio_toggle(void) { audio_config.enable ^= 1; eeconfig_update_audio(audio_config.raw); if (audio_config.enable) audio_on_user(); } void audio_on(void) { audio_config.enable = 1; eeconfig_update_audio(audio_config.raw); audio_on_user(); } void audio_off(void) { audio_config.enable = 0; eeconfig_update_audio(audio_config.raw); } #ifdef VIBRATO_ENABLE // Vibrato rate functions void set_vibrato_rate(float rate) { vibrato_rate = rate; } void increase_vibrato_rate(float change) { vibrato_rate *= change; } void decrease_vibrato_rate(float change) { vibrato_rate /= change; } #ifdef VIBRATO_STRENGTH_ENABLE void set_vibrato_strength(float strength) { vibrato_strength = strength; } void increase_vibrato_strength(float change) { vibrato_strength *= change; } void decrease_vibrato_strength(float change) { vibrato_strength /= change; } #endif /* VIBRATO_STRENGTH_ENABLE */ #endif /* VIBRATO_ENABLE */ // Polyphony functions void set_polyphony_rate(float rate) { polyphony_rate = rate; } void enable_polyphony() { polyphony_rate = 5; } void disable_polyphony() { polyphony_rate = 0; } void increase_polyphony_rate(float change) { polyphony_rate *= change; } void decrease_polyphony_rate(float change) { polyphony_rate /= change; } // Timbre function void set_timbre(float timbre) { note_timbre = timbre; } // Tempo functions void set_tempo(uint8_t tempo) { note_tempo = tempo; } void decrease_tempo(uint8_t tempo_change) { note_tempo += tempo_change; } void increase_tempo(uint8_t tempo_change) { if (note_tempo - tempo_change < 10) { note_tempo = 10; } else { note_tempo -= tempo_change; } }