/* Copyright 2020 Rodolphe Belouin * * 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/>. */ #pragma once #include <stdbool.h> #include "debug.h" #include "timer.h" // Maximum number of steps: 256 #ifndef SEQUENCER_STEPS # define SEQUENCER_STEPS 16 #endif // Maximum number of tracks: 8 #ifndef SEQUENCER_TRACKS # define SEQUENCER_TRACKS 8 #endif #ifndef SEQUENCER_TRACK_THROTTLE # define SEQUENCER_TRACK_THROTTLE 3 #endif #ifndef SEQUENCER_PHASE_RELEASE_TIMEOUT # define SEQUENCER_PHASE_RELEASE_TIMEOUT 30 #endif /** * Make sure that the items of this enumeration follow the powers of 2, separated by a ternary variant. * Check the implementation of `get_step_duration` for further explanation. */ typedef enum { SQ_RES_2, SQ_RES_2T, SQ_RES_4, SQ_RES_4T, SQ_RES_8, SQ_RES_8T, SQ_RES_16, SQ_RES_16T, SQ_RES_32, SEQUENCER_RESOLUTIONS } sequencer_resolution_t; typedef struct { bool enabled; uint8_t steps[SEQUENCER_STEPS]; uint16_t track_notes[SEQUENCER_TRACKS]; uint8_t tempo; // Is a maximum tempo of 255 reasonable? sequencer_resolution_t resolution; } sequencer_config_t; /** * Because Digital Audio Workstations get overwhelmed when too many MIDI signals are sent concurrently, * We use a "phase" state machine to delay some of the events. */ typedef enum sequencer_phase_t { SEQUENCER_PHASE_ATTACK, // t=0ms, send the MIDI note on signal SEQUENCER_PHASE_RELEASE, // t=SEQUENCER_PHASE_RELEASE_TIMEOUT ms, send the MIDI note off signal SEQUENCER_PHASE_PAUSE // t=step duration ms, loop } sequencer_phase_t; typedef struct { uint8_t active_tracks; uint8_t current_track; uint8_t current_step; uint16_t timer; sequencer_phase_t phase; } sequencer_state_t; extern sequencer_config_t sequencer_config; // We expose the internal state to make the feature more "unit-testable" extern sequencer_state_t sequencer_internal_state; bool is_sequencer_on(void); void sequencer_toggle(void); void sequencer_on(void); void sequencer_off(void); void sequencer_set_track_notes(const uint16_t track_notes[SEQUENCER_TRACKS]); bool is_sequencer_track_active(uint8_t track); void sequencer_set_track_activation(uint8_t track, bool value); void sequencer_toggle_track_activation(uint8_t track); void sequencer_toggle_single_active_track(uint8_t track); #define sequencer_activate_track(track) sequencer_set_track_activation(track, true) #define sequencer_deactivate_track(track) sequencer_set_track_activation(track, false) bool is_sequencer_step_on(uint8_t step); bool is_sequencer_step_on_for_track(uint8_t step, uint8_t track); void sequencer_set_step(uint8_t step, bool value); void sequencer_toggle_step(uint8_t step); void sequencer_set_all_steps(bool value); #define sequencer_set_step_on(step) sequencer_set_step(step, true) #define sequencer_set_step_off(step) sequencer_set_step(step, false) #define sequencer_set_all_steps_on() sequencer_set_all_steps(true) #define sequencer_set_all_steps_off() sequencer_set_all_steps(false) uint8_t sequencer_get_tempo(void); void sequencer_set_tempo(uint8_t tempo); void sequencer_increase_tempo(void); void sequencer_decrease_tempo(void); sequencer_resolution_t sequencer_get_resolution(void); void sequencer_set_resolution(sequencer_resolution_t resolution); void sequencer_increase_resolution(void); void sequencer_decrease_resolution(void); uint8_t sequencer_get_current_step(void); uint16_t sequencer_get_beat_duration(void); uint16_t sequencer_get_step_duration(void); uint16_t get_beat_duration(uint8_t tempo); uint16_t get_step_duration(uint8_t tempo, sequencer_resolution_t resolution); void sequencer_task(void);