MidiFile _CreateMidiFile()
{
var file = new MidiFile();
// we'll need a track 0 for our tempo map
var track0 = new MidiSequence();
// set the tempo at the first position
track0.Events.Add(new MidiEvent(0, new MidiMessageMetaTempo((double)TempoUpDown.Value)));
// compute the length of our loop
var len = ((int)BarsUpDown.Value) * 4 * file.TimeBase;
// add an end of track marker just so all
// of our tracks will be the loop length
track0.Events.Add(new MidiEvent(len, new MidiMessageMetaEndOfTrack()));
// here we need a track end with an
// absolute position for the MIDI end
// of track meta message. We'll use this
// later to set the length of the track
var trackEnd = new MidiSequence();
trackEnd.Events.Add(new MidiEvent(len, new MidiMessageMetaEndOfTrack()));
// add track 0 (our tempo map)
file.Tracks.Add(track0);
// create track 1 (our drum track)
var track1 = new MidiSequence();
// we're going to create a new sequence for
// each one of the drum sequencer tracks in
// the UI
var trks = new List <MidiSequence>(BeatsPanel.Controls.Count);
foreach (var ctl in BeatsPanel.Controls)
{
var beat = ctl as BeatControl;
// get the note for the drum
var note = beat.NoteId;
// it's easier to use a note map
// to build the drum sequence
var noteMap = new List <MidiNote>();
for (int ic = beat.Steps.Count, i = 0; i < ic; ++i)
{
// if the step is pressed create
// a note for it
if (beat.Steps[i])
{
noteMap.Add(new MidiNote(i * (file.TimeBase / 4), 9, note, 127, file.TimeBase / 4 - 1));
}
}
// convert the note map to a sequence
// and add it to our working tracks
trks.Add(MidiSequence.FromNoteMap(noteMap));
}
// now we merge the sequences into one
var t = MidiSequence.Merge(trks);
// we merge everything down to track 1
track1 = MidiSequence.Merge(track1, t, trackEnd);
// .. and add it to the file
file.Tracks.Add(track1);
return(file);
}