1 files changed, 230 insertions, 51 deletions

diff --git a/quantum/audio/audio.h b/quantum/audio/audio.h
index dccf03d5f..56b9158a1 100644
--- a/quantum/audio/audio.h
+++ b/quantum/audio/audio.h
@@ -1,4 +1,5 @@
-/* Copyright 2016 Jack Humbert
+/* Copyright 2016-2020 Jack Humbert
+ * Copyright 2020 JohSchneider
  *
  * 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
@@ -13,28 +14,30 @@
  * 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 <stdint.h>
 #include <stdbool.h>
-#if defined(__AVR__)
-#    include <avr/io.h>
-#endif
-#include "wait.h"
 #include "musical_notes.h"
 #include "song_list.h"
 #include "voices.h"
 #include "quantum.h"
 #include <math.h>
 
-// Largely untested PWM audio mode (doesn't sound as good)
-// #define PWM_AUDIO
-
-// #define VIBRATO_ENABLE
+#if defined(__AVR__)
+#    include <avr/io.h>
+#    if defined(AUDIO_DRIVER_PWM)
+#        include "driver_avr_pwm.h"
+#    endif
+#endif
 
-// Enable vibrato strength/amplitude - slows down ISR too much
-// #define VIBRATO_STRENGTH_ENABLE
+#if defined(PROTOCOL_CHIBIOS)
+#    if defined(AUDIO_DRIVER_PWM)
+#        include "driver_chibios_pwm.h"
+#    elif defined(AUDIO_DRIVER_DAC)
+#        include "driver_chibios_dac.h"
+#    endif
+#endif
 
 typedef union {
     uint8_t raw;
@@ -45,62 +48,238 @@ typedef union {
     };
 } audio_config_t;
 
-bool is_audio_on(void);
+// AVR/LUFA has a MIN, arm/chibios does not
+#ifndef MIN
+#    define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/*
+ * a 'musical note' is represented by pitch and duration; a 'musical tone' adds intensity and timbre
+ * https://en.wikipedia.org/wiki/Musical_tone
+ * "A musical tone is characterized by its duration, pitch, intensity (or loudness), and timbre (or quality)"
+ */
+typedef struct {
+    uint16_t time_started;  // timestamp the tone/note was started, system time runs with 1ms resolution -> 16bit timer overflows every ~64 seconds, long enough under normal circumstances; but might be too soon for long-duration notes when the note_tempo is set to a very low value
+    float    pitch;         // aka frequency, in Hz
+    uint16_t duration;      // in ms, converted from the musical_notes.h unit which has 64parts to a beat, factoring in the current tempo in beats-per-minute
+    // float intensity;    // aka volume [0,1] TODO: not used at the moment; pwm drivers can't handle it
+    // uint8_t timbre;     // range: [0,100] TODO: this currently kept track of globally, should we do this per tone instead?
+} musical_tone_t;
+
+// public interface
+
+/**
+ * @brief one-time initialization called by quantum/quantum.c
+ * @details usually done lazy, when some tones are to be played
+ *
+ * @post audio system (and hardware) initialized and ready to play tones
+ */
+void audio_init(void);
+void audio_startup(void);
+
+/**
+ * @brief en-/disable audio output, save this choice to the eeprom
+ */
 void audio_toggle(void);
+/**
+ * @brief enable audio output, save this choice to the eeprom
+ */
 void audio_on(void);
+/**
+ * @brief disable audio output, save this choice to the eeprom
+ */
 void audio_off(void);
+/**
+ * @brief query the if audio output is enabled
+ */
+bool audio_is_on(void);
 
-// Vibrato rate functions
+/**
+ * @brief start playback of a tone with the given frequency and duration
+ *
+ * @details starts the playback of a given note, which is automatically stopped
+ *          at the the end of its duration = fire&forget
+ *
+ * @param[in] pitch frequency of the tone be played
+ * @param[in] duration in milliseconds, use 'audio_duration_to_ms' to convert
+ *                     from the musical_notes.h unit to ms
+ */
+void audio_play_note(float pitch, uint16_t duration);
+// TODO: audio_play_note(float pitch, uint16_t duration, float intensity, float timbre);
+// audio_play_note_with_instrument ifdef AUDIO_ENABLE_VOICES
 
-#ifdef VIBRATO_ENABLE
+/**
+ * @brief start playback of a tone with the given frequency
+ *
+ * @details the 'frequency' is put on-top the internal stack of active tones,
+ *          as a new tone with indefinite duration. this tone is played by
+ *          the hardware until a call to 'audio_stop_tone'.
+ *          should a tone with that frequency already be active, its entry
+ *          is put on the top of said internal stack - so no duplicate
+ *          entries are kept.
+ *          'hardware_start' is called upon the first note.
+ *
+ * @param[in] pitch frequency of the tone be played
+ */
+void audio_play_tone(float pitch);
 
-void set_vibrato_rate(float rate);
-void increase_vibrato_rate(float change);
-void decrease_vibrato_rate(float change);
+/**
+ * @brief stop a given tone/frequency
+ *
+ * @details removes a tone matching the given frequency from the internal
+ *          playback stack
+ *          the hardware is stopped in case this was the last/only frequency
+ *          being played.
+ *
+ * @param[in] pitch tone/frequency to be stopped
+ */
+void audio_stop_tone(float pitch);
 
-#    ifdef VIBRATO_STRENGTH_ENABLE
+/**
+ * @brief play a melody
+ *
+ * @details starts playback of a melody passed in from a SONG definition - an
+ *          array of {pitch, duration} float-tuples
+ *
+ * @param[in] np note-pointer to the SONG array
+ * @param[in] n_count number of MUSICAL_NOTES of the SONG
+ * @param[in] n_repeat false for onetime, true for looped playback
+ */
+void audio_play_melody(float (*np)[][2], uint16_t n_count, bool n_repeat);
 
-void set_vibrato_strength(float strength);
-void increase_vibrato_strength(float change);
-void decrease_vibrato_strength(float change);
+/**
+ * @brief play a short tone of a specific frequency to emulate a 'click'
+ *
+ * @details constructs a two-note melody (one pause plus a note) and plays it through
+ *          audio_play_melody. very short durations might not quite work due to
+ *          hardware limitations (DAC: added pulses from zero-crossing feature;...)
+ *
+ * @param[in] delay in milliseconds, length for the pause before the pulses, can be zero
+ * @param[in] pitch
+ * @param[in] duration in milliseconds, length of the 'click'
+ */
+void audio_play_click(uint16_t delay, float pitch, uint16_t duration);
 
-#    endif
+/**
+ * @brief stops all playback
+ *
+ * @details stops playback of both a melody as well as single tones, resetting
+ *          the internal state
+ */
+void audio_stop_all(void);
 
-#endif
+/**
+ * @brief query if one/multiple tones are playing
+ */
+bool audio_is_playing_note(void);
 
-// Polyphony functions
+/**
+ * @brief query if a melody/SONG is playing
+ */
+bool audio_is_playing_melody(void);
 
-void set_polyphony_rate(float rate);
-void enable_polyphony(void);
-void disable_polyphony(void);
-void increase_polyphony_rate(float change);
-void decrease_polyphony_rate(float change);
+// These macros are used to allow audio_play_melody to play an array of indeterminate
+// length. This works around the limitation of C's sizeof operation on pointers.
+// The global float array for the song must be used here.
+#define NOTE_ARRAY_SIZE(x) ((int16_t)(sizeof(x) / (sizeof(x[0]))))
 
-void set_timbre(float timbre);
-void set_tempo(uint8_t tempo);
+/**
+ * @brief convenience macro, to play a melody/SONG once
+ */
+#define PLAY_SONG(note_array) audio_play_melody(&note_array, NOTE_ARRAY_SIZE((note_array)), false)
+// TODO: a 'song' is a melody plus singing/vocals -> PLAY_MELODY
+/**
+ * @brief convenience macro, to play a melody/SONG in a loop, until stopped by 'audio_stop_all'
+ */
+#define PLAY_LOOP(note_array) audio_play_melody(&note_array, NOTE_ARRAY_SIZE((note_array)), true)
 
-void increase_tempo(uint8_t tempo_change);
-void decrease_tempo(uint8_t tempo_change);
+// Tone-Multiplexing functions
+// this feature only makes sense for hardware setups which can't do proper
+// audio-wave synthesis = have no DAC and need to use PWM for tone generation
+#ifdef AUDIO_ENABLE_TONE_MULTIPLEXING
+#    ifndef AUDIO_TONE_MULTIPLEXING_RATE_DEFAULT
+#        define AUDIO_TONE_MULTIPLEXING_RATE_DEFAULT 0
+//       0=off, good starting value is 4; the lower the value the higher the cpu-load
+#    endif
+void audio_set_tone_multiplexing_rate(uint16_t rate);
+void audio_enable_tone_multiplexing(void);
+void audio_disable_tone_multiplexing(void);
+void audio_increase_tone_multiplexing_rate(uint16_t change);
+void audio_decrease_tone_multiplexing_rate(uint16_t change);
+#endif
+
+// Tempo functions
+
+void audio_set_tempo(uint8_t tempo);
+void audio_increase_tempo(uint8_t tempo_change);
+void audio_decrease_tempo(uint8_t tempo_change);
+
+// conversion macros, from 64parts-to-a-beat to milliseconds and back
+uint16_t audio_duration_to_ms(uint16_t duration_bpm);
+uint16_t audio_ms_to_duration(uint16_t duration_ms);
 
-void audio_init(void);
 void audio_startup(void);
 
-#ifdef PWM_AUDIO
-void play_sample(uint8_t* s, uint16_t l, bool r);
-#endif
-void play_note(float freq, int vol);
-void stop_note(float freq);
-void stop_all_notes(void);
-void play_notes(float (*np)[][2], uint16_t n_count, bool n_repeat);
+// hardware interface
 
-#define SCALE \
-    (int8_t[]) { 0 + (12 * 0), 2 + (12 * 0), 4 + (12 * 0), 5 + (12 * 0), 7 + (12 * 0), 9 + (12 * 0), 11 + (12 * 0), 0 + (12 * 1), 2 + (12 * 1), 4 + (12 * 1), 5 + (12 * 1), 7 + (12 * 1), 9 + (12 * 1), 11 + (12 * 1), 0 + (12 * 2), 2 + (12 * 2), 4 + (12 * 2), 5 + (12 * 2), 7 + (12 * 2), 9 + (12 * 2), 11 + (12 * 2), 0 + (12 * 3), 2 + (12 * 3), 4 + (12 * 3), 5 + (12 * 3), 7 + (12 * 3), 9 + (12 * 3), 11 + (12 * 3), 0 + (12 * 4), 2 + (12 * 4), 4 + (12 * 4), 5 + (12 * 4), 7 + (12 * 4), 9 + (12 * 4), 11 + (12 * 4), }
+// implementation in the driver_avr/arm_* respective parts
+void audio_driver_initialize(void);
+void audio_driver_start(void);
+void audio_driver_stop(void);
 
-// These macros are used to allow play_notes to play an array of indeterminate
-// length. This works around the limitation of C's sizeof operation on pointers.
-// The global float array for the song must be used here.
-#define NOTE_ARRAY_SIZE(x) ((int16_t)(sizeof(x) / (sizeof(x[0]))))
-#define PLAY_SONG(note_array) play_notes(&note_array, NOTE_ARRAY_SIZE((note_array)), false)
-#define PLAY_LOOP(note_array) play_notes(&note_array, NOTE_ARRAY_SIZE((note_array)), true)
+/**
+ * @brief get the number of currently active tones
+ * @return number, 0=none active
+ */
+uint8_t audio_get_number_of_active_tones(void);
+
+/**
+ * @brief access to the raw/unprocessed frequency for a specific tone
+ * @details each active tone has a frequency associated with it, which
+ *          the internal state keeps track of, and is usually influenced
+ *          by various effects
+ * @param[in] tone_index, ranging from 0 to number_of_active_tones-1, with the
+ *            first being the most recent and each increment yielding the next
+ *            older one
+ * @return a positive frequency, in Hz; or zero if the tone is a pause
+ */
+float audio_get_frequency(uint8_t tone_index);
+
+/**
+ * @brief calculate and return the frequency for the requested tone
+ * @details effects like glissando, vibrato, ... are post-processed onto the
+ *          each active tones 'base'-frequency; this function returns the
+ *          post-processed result.
+ * @param[in] tone_index, ranging from 0 to number_of_active_tones-1, with the
+ *            first being the most recent and each increment yielding the next
+ *            older one
+ * @return a positive frequency, in Hz; or zero if the tone is a pause
+ */
+float audio_get_processed_frequency(uint8_t tone_index);
+
+/**
+ * @brief   update audio internal state: currently playing and active tones,...
+ * @details This function is intended to be called by the audio-hardware
+ *          specific implementation on a somewhat regular basis while a SONG
+ *          or notes (pitch+duration) are playing to 'advance' the internal
+ *          state (current playing notes, position in the melody, ...)
+ *
+ * @return true if something changed in the currently active tones, which the
+ *         hardware might need to react to
+ */
+bool audio_update_state(void);
+
+// legacy and back-warts compatibility stuff
+
+#define is_audio_on() audio_is_on()
+#define is_playing_notes() audio_is_playing_melody()
+#define is_playing_note() audio_is_playing_note()
+#define stop_all_notes() audio_stop_all()
+#define stop_note(f) audio_stop_tone(f)
+#define play_note(f, v) audio_play_tone(f)
 
-bool is_playing_notes(void);
+#define set_timbre(t) voice_set_timbre(t)
+#define set_tempo(t) audio_set_tempo(t)
+#define increase_tempo(t) audio_increase_tempo(t)
+#define decrease_tempo(t) audio_decrease_tempo(t)
+// vibrato functions are not used in any keyboards