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import Tone from 'tone'
import WebMidi from 'webmidi'
import scales from './scales'
import { ftom, norm } from './util'
import kalimba from './kalimba'
import { nx } from './ui'
let midiDevice
let sendPitchBend = false
export const MidiWriter = require('midi-writer-js')
export const note_values = [
[8, '8 measures', 8 * 512],
[4, '4 measures', 4 * 512],
[2, '2 measures', 2 * 512],
[1, 'whole note', 512],
[1/2, 'half note', 256],
[1/3, 'third note', [170, 170, 171]],
[1/4, 'quarter note', 128],
[1/5, 'fifth note', [51,51,51,51,52]],
[1/6, 'sixth note', [85, 85, 86, 85, 85, 86]],
[1/8, 'eighth note', 64],
[1/10, 'tenth note', [25,26,26,25,26,25,26,26,25,26]],
[1/12, 'twelfth note', [21,21,22, 21,21,22, 21,21,22, 21,21,22]],
[1/16, 'sixteenth note', 32],
[1/32, 'thirtysecond note', 16],
]
export function midi_init() {
WebMidi.enable(midi_ready)
function midi_ready(err) {
if (err) {
console.error('webmidi failed to initialize')
return
}
if (!WebMidi.outputs.length) {
console.error('no MIDI output found')
return
}
console.log(WebMidi.inputs)
console.log(WebMidi.outputs)
if (WebMidi.outputs.length > 1) {
const filtered = WebMidi.outputs.filter(output => output.name.match(/prodipe/i))
if (filtered.length) {
// midiDevice = filtered[0]
}
}
// midiDevice = midiDevice || WebMidi.outputs[0]
// console.log(midiDevice.name)
}
}
/* play a single note */
export function play_note(index, duration, channel="all", exporting=false, defer=0){
// console.log(index)
const scale = scales.current()
const freq = scale.index(index + Math.round(nx.offset.value), nx.octave.value)
let midi_note = ftom(freq)
let cents = midi_note % 1
if (cents > 0.5) {
midi_note += 1
cents -= 1
}
cents *= 2
midi_note = Math.floor(midi_note)
if ((midiDevice || exporting) && midi_note > 127) return 0
const note = Tone.Frequency(Math.floor(midi_note), "midi").toNote()
if (exporting || midiDevice) {
duration = duration || 60000 / Tone.Transport.bpm.value
if (! exporting) {
if (defer) {
setTimeout(() => {
play_midi_note(note, cents, channel, duration)
}, defer)
} else {
play_midi_note(note, cents, channel, duration)
}
}
} else {
kalimba.play(freq)
}
return note
}
export function play_midi_note(note, cents, channel, duration) {
midiDevice.playNote(note, channel, { duration })
if (sendPitchBend) {
midiDevice.sendPitchBend(cents, channel)
}
}
/* play the next note in sequence */
export function play_sequence(i, bounds, diff, note_time, channel="all", exporting) {
const { rows, min, max } = bounds
const count = rows.length * rows[0].length
if (i >= count) i = 0
const y = Math.floor(i / rows[0].length)
const x = i % rows[0].length
// if (!x) console.log(y)
const n = rows[y][x]
i += 1
if (i >= count) i = 0
const midi_note = play_note( norm(n, min, max) * nx.multiply.value, note_time, channel, exporting)
return [i, [midi_note]]
}
/* play the next row as an interval */
export function play_interval_sequence(i, bounds, diff, note_time, channel="all", exporting) {
const { rows, min, max } = bounds
const count = rows.length
if (i >= count) i = 0
const y = i % count
const row = rows[y]
if (! row) { i = 0; return }
const row_min = Math.min.apply(Math, row)
// const row_max = Math.max.apply(Math, row)
const row_f0 = norm(row_min, min, max)
const row_root = row_f0 * nx.multiply.value
const notes = row.map(n => {
const note = row_root + norm(n - row_min, diff.min, diff.max) * nx.interval.value
play_note(note, note_time, channel, exporting)
})
i += 1
return [i, notes]
}
/* generate a 1-track midi file by calling the play function repeatedly */
export function export_pattern_as_midi(datasetName, bounds, diff, tempo, timingIndex, play_fn) {
const behavior = document.querySelector('#behavior').value
const { rows } = bounds
let count = behavior === 'sequence' ? rows[0].length * rows.length : rows.length
let notes
let note_time
let timing = note_values[timingIndex][2]
let midi_track = new MidiWriter.Track()
midi_track.setTempo(tempo)
for (let i = 0, len = count; i < len; i++) {
notes = play_fn(i, bounds, note_time, "all", true)[1]
if (timing.length) {
note_time = timing[i % timing.length]
} else {
note_time = timing
}
midi_track.addEvent(new MidiWriter.NoteEvent({ pitch: notes, duration: 't' + note_time }))
}
const writer = new MidiWriter.Writer([midi_track])
const blob = dataURItoBlob(writer.dataUri())
saveAs(blob, 'Recording - ' + datasetName + '.mid')
}
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