public static bool IsInSameMeasure(MIDIEventHelper a, MIDIEventHelper b)
{
int measure_a = Mathf.FloorToInt(a.TimeMeasures);
int measure_b = Mathf.FloorToInt(b.TimeMeasures);
return(measure_a == measure_b);
}
public bool GetEvent(int index, out MIDIEventHelper @event)
{
bool result = index >= 0 && index < _Events.Count;
if (result)
{
@event = _Events[index];
}
else
{
@event = null;
}
return(result);
}
public MIDIEventList(MidiData midi_data, TrackChunk track, MIDIEventFilter filter)
{
// TODO: get beats per measure by reading all
// Midi.Events.MetaEvents.TimeSignatureEvents
// along with the notes in the track (i.e.
// time signature changes, etc.)
float beats_per_measure = 4f;
// Calculate the time scale as the reciprocal
// of the MIDI time_division
// time_division is also known as PPQ
// https://en.wikipedia.org/wiki/Pulses_per_quarter_note
float time_beats_scale = 1f / midi_data.header.time_division;
float time_beats_to_measures_scale = 1f / beats_per_measure;
// Instatiate the event list
pEvents = new List <MIDIEventHelper>();
// Starting from time zero
float time_beats = 0f;
float time_measures = 0f;
// Keep track of the last note-on events and
// match them with note-off events that follow,
// then store the time between the events as
// the duration in the event helper
MIDIEventHelper[] notes_on_last = new MIDIEventHelper[256];
// Keep track of the valid event index
int index = 0;
// Add all of the events needed for this track to the backing list (pEvents)
MIDIEventHelper previous_helper = null;
var track_filtered = track.events.Where(MIDIEventListFilter);
foreach (var midi_event in track_filtered)
{
if (filter.Accepts(midi_event))
{
// Calculate the event time based on delta_time
// delta_time is measured in ticks
float delta_time = (float)midi_event.delta_time;
time_beats += time_beats_scale * delta_time;
// Quantize to 32nd notes
time_beats = Quantize(time_beats, 32);
time_measures += time_beats_to_measures_scale * time_beats;
// Create an event helper (wrapper for event and details)
MIDIEventHelper current_event_helper = new MIDIEventHelper()
{
MIDIEvent = midi_event,
Index = index,
TimeBeats = time_beats,
TimeMeasures = time_measures,
DurationBeats = 0f,
};
// Add the event helper to the backing list
pEvents.Add(current_event_helper);
// If this event is a note off event
if (midi_event is NoteOffEvent)
{
var note_off = midi_event as NoteOffEvent;
int number = note_off.note_number;
var on_event_helper = notes_on_last[number];
if (on_event_helper != null)
{
float duration = time_beats - on_event_helper.TimeBeats;
on_event_helper.DurationBeats = duration;
current_event_helper.DurationBeats = duration;
}
// The note off event is not accounted for when consolidating
}
// If this event is a note on event
else if (midi_event is NoteOnEvent)
{
// Store it as the last note-on event for this note number
var note_on = midi_event as NoteOnEvent;
int number = note_on.note_number;
notes_on_last[number] = current_event_helper;
}
index++;
previous_helper = current_event_helper;
}
else if (MIDIEventFilter.TrackNameFilter.Accepts(midi_event))
{
Name = track.chunk_ID ?? "";
// TODO: get this working
//var name = (m_e.Element as Midi.Events.MetaEvents.SequenceOrTrackNameEvent).name;
// Small workaround for bug in MIDI parsing library
//Name = name.Trim(new[] {'\0'});
}
}
}
