CODEWITHSUNDEEP
iosmidicoremidi
Meda
Meda

Reputation: 2936

Using MusicTrackNewMIDINoteEvent to add note while playing

I'm building a drum machine to learn how to use MIDIs on iOS. I managed to get it working to one point, however, I have the following problem. When the user taps a certain button I need to add a sound to my MIDI loop while the MIDI player is playing and unfortunately I can't simply do: 

MusicTrackNewMIDINoteEvent(track, 0, &message);

although the track is looping and has a determined length, so theoretically it should come back to 0 at one point. I also tried this:

MusicTrackNewMIDINoteEvent(track, noteTimestamp, &message);

where noteTimestamp is the timestamp I receive from the player. Finally, I managed to get it working with something like this:

MusicTrackNewMIDINoteEvent(track, noteTimestamp+.5, &message);

but it's needless to say that the .5 delay is not really what I would want for my drum machine, which should be as responsive as possible.

So, how does one tackle this problem? How can you push a note on the track as soon as possible, without any delay?

Upvotes: 2

Views: 596

Answers (1)

bob
bob

Reputation: 7985

You're laying down an event on the track, and by the time you lay the event down the "playhead" is already past the point where it can do anything with it.

So continue to do what you're doing (without shifting the time) as a means to "record" the event for the next time the loop "comes around", but you'll need to fire off a midi message manually -- apart from the track as:

(int) note = 60;
(int) velocuty = 127;
(int) offset = 0;
MusicDeviceMIDIEvent(_yourSamplerUnit, kMIDIMessage_NoteOn << 4 | 0, note, velocity, offset);

Again, firing a manual midi event will allow the listener to hear the sound, and laying down the event into the track will allow your track to "record" it for the next time 'round.

Upvotes: 1

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