Blog Outline - Web MIDI API

MIDI.org itself says “the Web-MIDI API is the most significant advancement of MIDI since… MIDI itself!”

- Why its awesome
Enabled by default in chrome - no software or setup needed
Works on all platforms and devices. Anything with a web browser can run a Web-MIDI app and use local MIDI hardware.
Works with your existing MIDI setup. If your MIDI gear is connected to your computer, tablet or phone (by a cable or even wirelessly) that same connection will connect your MIDI gear to your Web-MIDI enabled browser.
Updates are automatic. No need to install new versions, the latest version is always available at the website URL.
Accessible anywhere. Apps and data in “the Cloud” are available anywhere you have an internet connection.
Browsers make it easy to connect you and your music to other people via social media and on-line MIDI communities.

- Basic Setup
requestMIDIAccess()
method returns a ‘MIDI Access’ object, which contains all of our connected device’s info. This ‘MIDI Access’ object gets passed to the onMIDISuccess

onMIDISuccess()
this is where you set up all your inputs/signals etc

onMidiMessage()
the heart of the midi controller. passes "message" with all midi data on every event on the keyboard


function onMIDISuccess(midiAccess){
	midi = midiAccess;
	var inputs = midi.inputs.values();
	// loop through all inputs
	for(var input = inputs.next(); input && !input.done; input = inputs.next()){
		// listen for midi messages
		input.value.onmidimessage = onMIDIMessage;

		listInputs(input);
	}
	// listen for connect/disconnect message
	midi.onstatechange = onStateChange;

	showMIDIPorts(midi);
}

function onMIDIMessage(event){
	data = event.data,
	cmd = data[0] >> 4,
	channel = data[0] & 0xf,
	type = data[0] & 0xf0, // channel agnostic message type. Thanks, Phil Burk.
	note = data[1],
	velocity = data[2];
	// with pressure and tilt off
	// note off: 128, cmd: 8
	// note on: 144, cmd: 9
	// pressure / tilt on
	// pressure: 176, cmd 11:
	// bend: 224, cmd: 14
	// log('MIDI data', data);
	switch(type){
		case 144: // noteOn message
			noteOn(note, velocity);
			break;
		case 128: // noteOff message
			noteOff(note, velocity);
			break;
	}
	data[0]
	144: note down
	128: note off
	data[1]
	the note!
	data[2]
	velocity
	
	then all we have to do is set up a player!