I've done some things with multitouch buttons. Now I would however make a multitouch to a singletouch.
Only the first touch generates a down. All other touches, which are added as long as the first touch was still active, should be ignored. So I have to remember the highest ID, if the first TouchID, which has generated the down, disappears. Then again a touch is generated again when a new ID comes. Would that be logical? Or is it better to wait until no touches are left. Anyone experience with that case.