cycle-midi #

Cycle.js drivers to send and receive notes using Web MIDI.

Drivers ##

- connectionDriver
- instrumentDriver

$3

connectionDriver accepts a stream. Whenever that stream dispatches, it tries to connect to the instrument over Web MIDI. It returns a stream that dispatches true when the connection attempt succeeds and false when it fails.

$3

instrumentDriver accepts a stream of notes to send to the instrument. It may eventually return a stream of notes played on the instrument, but it doesn't do that yet.

Example ##

``javascript
function Background({ messages: message$, instrumentConnection: instrumentAvailability$ }) {
const connectionRequest$ = message$.filter(
message => message.type === 'connect_to_instrument'
);

const playRandomNote$ = message$.filter(
message => message.type === 'play_random_note'
);

return {
instrumentConnection: connectionRequest$,
instrument: playRandomNote$.map(
() => (
{
// the MIDI ID of the note, from 21 for A0 to 108 for C8
note,

// number of milliseconds to play a note for
duration: 150,

// 1 is very soft; 128 is very hard
velocity: Math.random() * 128,

// number of milliseconds since the instrument connection to wait
// before playing this note
time: 0,
}
)
),
messages: instrumentAvailability$.map(
isAvailable => (
{
type: 'instrument_availability_changed',
payload: true,
}
)
),
}
}
`

To see an real extension written with these drivers, check out the midicast source code.

Installation ##

`
yarn add cycle-midi
`

Usage ##

Because the two drivers share a single connection to the instrument, you must instantiate them together with makeInstrumentAndConnectionDriver():

`javascript
import {
makeInstrumentAndConnectionDriver,
} from 'cycle-midi';

const {
instrumentDriver,
connectionDriver,
} = makeInstrumentAndConnectionDriver();

run(
Background,
{
instrument: instrumentDriver,
instrumentConnection: connectionDriver,
}
);
``

License ##

Apache 2.0