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/* 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 <stdint.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);
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