How NoteInputs, filter masks, and onMidi callbacks work in Bitwig controller scripts

BitwigScriptingDefaultNoteInput.control.js

loadAPI(1);

host.defineController("Script Lab", "NoteInput Testing", "1.0", "d5a765f7-647a-488e-938f-dcb653742457");
host.defineMidiPorts(1, 0);

var input;

function init()
{
  var mi = host.getMidiInPort(0);
  mi.setMidiCallback(onMidi);
  
  // MIDI input with default MIDI message filter
  input = mi.createNoteInput("");
   
  println("initialized");
}

function onMidi(status, data1, data2)
{
  var command = status & 0xf0;
  var channel = (status & 0x0f) + 1;
  println("channel=" + channel + ", command=" + command + ", data1=" + data1 + ", data2=" + data2);
}

function exit() { }