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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/>.
- */
-
- #include "sequencer.h"
-
- #ifdef MIDI_ENABLE
- # include "process_midi.h"
- #endif
-
- #ifdef MIDI_MOCKED
- # include "tests/midi_mock.h"
- #endif
-
- sequencer_config_t sequencer_config = {
- false, // enabled
- {false}, // steps
- {0}, // track notes
- 60, // tempo
- SQ_RES_4, // resolution
- };
-
- sequencer_state_t sequencer_internal_state = {0, 0, 0, 0, SEQUENCER_PHASE_ATTACK};
-
- bool is_sequencer_on(void) { return sequencer_config.enabled; }
-
- void sequencer_on(void) {
- dprintln("sequencer on");
- sequencer_config.enabled = true;
- sequencer_internal_state.current_track = 0;
- sequencer_internal_state.current_step = 0;
- sequencer_internal_state.timer = timer_read();
- sequencer_internal_state.phase = SEQUENCER_PHASE_ATTACK;
- }
-
- void sequencer_off(void) {
- dprintln("sequencer off");
- sequencer_config.enabled = false;
- sequencer_internal_state.current_step = 0;
- }
-
- void sequencer_toggle(void) {
- if (is_sequencer_on()) {
- sequencer_off();
- } else {
- sequencer_on();
- }
- }
-
- void sequencer_set_track_notes(const uint16_t track_notes[SEQUENCER_TRACKS]) {
- for (uint8_t i = 0; i < SEQUENCER_TRACKS; i++) {
- sequencer_config.track_notes[i] = track_notes[i];
- }
- }
-
- bool is_sequencer_track_active(uint8_t track) { return (sequencer_internal_state.active_tracks >> track) & true; }
-
- void sequencer_set_track_activation(uint8_t track, bool value) {
- if (value) {
- sequencer_internal_state.active_tracks |= (1 << track);
- } else {
- sequencer_internal_state.active_tracks &= ~(1 << track);
- }
- dprintf("sequencer: track %d is %s\n", track, value ? "active" : "inactive");
- }
-
- void sequencer_toggle_track_activation(uint8_t track) { sequencer_set_track_activation(track, !is_sequencer_track_active(track)); }
-
- void sequencer_toggle_single_active_track(uint8_t track) {
- if (is_sequencer_track_active(track)) {
- sequencer_internal_state.active_tracks = 0;
- } else {
- sequencer_internal_state.active_tracks = 1 << track;
- }
- }
-
- bool is_sequencer_step_on(uint8_t step) { return step < SEQUENCER_STEPS && (sequencer_config.steps[step] & sequencer_internal_state.active_tracks) > 0; }
-
- bool is_sequencer_step_on_for_track(uint8_t step, uint8_t track) { return step < SEQUENCER_STEPS && (sequencer_config.steps[step] >> track) & true; }
-
- void sequencer_set_step(uint8_t step, bool value) {
- if (step < SEQUENCER_STEPS) {
- if (value) {
- sequencer_config.steps[step] |= sequencer_internal_state.active_tracks;
- } else {
- sequencer_config.steps[step] &= ~sequencer_internal_state.active_tracks;
- }
- dprintf("sequencer: step %d is %s\n", step, value ? "on" : "off");
- } else {
- dprintf("sequencer: step %d is out of range\n", step);
- }
- }
-
- void sequencer_toggle_step(uint8_t step) {
- if (is_sequencer_step_on(step)) {
- sequencer_set_step_off(step);
- } else {
- sequencer_set_step_on(step);
- }
- }
-
- void sequencer_set_all_steps(bool value) {
- for (uint8_t step = 0; step < SEQUENCER_STEPS; step++) {
- if (value) {
- sequencer_config.steps[step] |= sequencer_internal_state.active_tracks;
- } else {
- sequencer_config.steps[step] &= ~sequencer_internal_state.active_tracks;
- }
- }
- dprintf("sequencer: all steps are %s\n", value ? "on" : "off");
- }
-
- uint8_t sequencer_get_tempo(void) { return sequencer_config.tempo; }
-
- void sequencer_set_tempo(uint8_t tempo) {
- if (tempo > 0) {
- sequencer_config.tempo = tempo;
- dprintf("sequencer: tempo set to %d bpm\n", tempo);
- } else {
- dprintln("sequencer: cannot set tempo to 0");
- }
- }
-
- void sequencer_increase_tempo(void) {
- // Handling potential uint8_t overflow
- if (sequencer_config.tempo < UINT8_MAX) {
- sequencer_set_tempo(sequencer_config.tempo + 1);
- } else {
- dprintf("sequencer: cannot set tempo above %d\n", UINT8_MAX);
- }
- }
-
- void sequencer_decrease_tempo(void) { sequencer_set_tempo(sequencer_config.tempo - 1); }
-
- sequencer_resolution_t sequencer_get_resolution(void) { return sequencer_config.resolution; }
-
- void sequencer_set_resolution(sequencer_resolution_t resolution) {
- if (resolution >= 0 && resolution < SEQUENCER_RESOLUTIONS) {
- sequencer_config.resolution = resolution;
- dprintf("sequencer: resolution set to %d\n", resolution);
- } else {
- dprintf("sequencer: resolution %d is out of range\n", resolution);
- }
- }
-
- void sequencer_increase_resolution(void) { sequencer_set_resolution(sequencer_config.resolution + 1); }
-
- void sequencer_decrease_resolution(void) { sequencer_set_resolution(sequencer_config.resolution - 1); }
-
- uint8_t sequencer_get_current_step(void) { return sequencer_internal_state.current_step; }
-
- void sequencer_phase_attack(void) {
- dprintf("sequencer: step %d\n", sequencer_internal_state.current_step);
- dprintf("sequencer: time %d\n", timer_read());
-
- if (sequencer_internal_state.current_track == 0) {
- sequencer_internal_state.timer = timer_read();
- }
-
- if (timer_elapsed(sequencer_internal_state.timer) < sequencer_internal_state.current_track * SEQUENCER_TRACK_THROTTLE) {
- return;
- }
-
- #if defined(MIDI_ENABLE) || defined(MIDI_MOCKED)
- if (is_sequencer_step_on_for_track(sequencer_internal_state.current_step, sequencer_internal_state.current_track)) {
- process_midi_basic_noteon(midi_compute_note(sequencer_config.track_notes[sequencer_internal_state.current_track]));
- }
- #endif
-
- if (sequencer_internal_state.current_track < SEQUENCER_TRACKS - 1) {
- sequencer_internal_state.current_track++;
- } else {
- sequencer_internal_state.phase = SEQUENCER_PHASE_RELEASE;
- }
- }
-
- void sequencer_phase_release(void) {
- if (timer_elapsed(sequencer_internal_state.timer) < SEQUENCER_PHASE_RELEASE_TIMEOUT + sequencer_internal_state.current_track * SEQUENCER_TRACK_THROTTLE) {
- return;
- }
- #if defined(MIDI_ENABLE) || defined(MIDI_MOCKED)
- if (is_sequencer_step_on_for_track(sequencer_internal_state.current_step, sequencer_internal_state.current_track)) {
- process_midi_basic_noteoff(midi_compute_note(sequencer_config.track_notes[sequencer_internal_state.current_track]));
- }
- #endif
- if (sequencer_internal_state.current_track > 0) {
- sequencer_internal_state.current_track--;
- } else {
- sequencer_internal_state.phase = SEQUENCER_PHASE_PAUSE;
- }
- }
-
- void sequencer_phase_pause(void) {
- if (timer_elapsed(sequencer_internal_state.timer) < sequencer_get_step_duration()) {
- return;
- }
-
- sequencer_internal_state.current_step = (sequencer_internal_state.current_step + 1) % SEQUENCER_STEPS;
- sequencer_internal_state.phase = SEQUENCER_PHASE_ATTACK;
- }
-
- void sequencer_task(void) {
- if (!sequencer_config.enabled) {
- return;
- }
-
- if (sequencer_internal_state.phase == SEQUENCER_PHASE_PAUSE) {
- sequencer_phase_pause();
- }
-
- if (sequencer_internal_state.phase == SEQUENCER_PHASE_RELEASE) {
- sequencer_phase_release();
- }
-
- if (sequencer_internal_state.phase == SEQUENCER_PHASE_ATTACK) {
- sequencer_phase_attack();
- }
- }
-
- uint16_t sequencer_get_beat_duration(void) { return get_beat_duration(sequencer_config.tempo); }
-
- uint16_t sequencer_get_step_duration(void) { return get_step_duration(sequencer_config.tempo, sequencer_config.resolution); }
-
- uint16_t get_beat_duration(uint8_t tempo) {
- // Don’t crash in the unlikely case where the given tempo is 0
- if (tempo == 0) {
- return get_beat_duration(60);
- }
-
- /**
- * Given
- * t = tempo and d = duration, both strictly greater than 0
- * When
- * t beats / minute = 1 beat / d ms
- * Then
- * t beats / 60000ms = 1 beat / d ms
- * d ms = 60000ms / t
- */
- return 60000 / tempo;
- }
-
- uint16_t get_step_duration(uint8_t tempo, sequencer_resolution_t resolution) {
- /**
- * Resolution cheatsheet:
- * 1/2 => 2 steps per 4 beats
- * 1/2T => 3 steps per 4 beats
- * 1/4 => 4 steps per 4 beats
- * 1/4T => 6 steps per 4 beats
- * 1/8 => 8 steps per 4 beats
- * 1/8T => 12 steps per 4 beats
- * 1/16 => 16 steps per 4 beats
- * 1/16T => 24 steps per 4 beats
- * 1/32 => 32 steps per 4 beats
- *
- * The number of steps for binary resolutions follows the powers of 2.
- * The ternary variants are simply 1.5x faster.
- */
- bool is_binary = resolution % 2 == 0;
- uint8_t binary_steps = 2 << (resolution / 2);
- uint16_t binary_step_duration = get_beat_duration(tempo) * 4 / binary_steps;
-
- return is_binary ? binary_step_duration : 2 * binary_step_duration / 3;
- }
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