path: root/client/index.js

import Tone from 'tone'
import WebMidi from 'webmidi'
import Nexus from 'nexusui'
import keys from './lib/keys'
import kalimba from './lib/kalimba'
import scales from './lib/scales'
import { requestAudioContext, ftom, dataURItoBlob } from './lib/util'
import { saveAs } from 'file-saver/FileSaver'

import * as data from './data'

const MidiWriter = require('midi-writer-js')

const DEFAULT_BPM = 60

const nx = window.nx = {}

let midi
let exporting = false
let recording = false
let recorder = null

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],
]

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) {
      midi = filtered[0]
    }
  }
  midi = midi || WebMidi.outputs[0]
  console.log(midi.name)
}

let i = 0, datasets = {}, dataset = {}, bounds = {}, diff = []
let play_fn = play_sequence
data.load().then(lists => {
  // nx.dataset.choices = Object.keys(lists)
  console.log(lists) 
  datasets = lists
  pick_dataset('housing costs and income inequality')
  requestAudioContext(ready)
})

function pick_dataset(key){
  console.log('pick dataset:', key)
  i = 0
  dataset = datasets[key]
  bounds = get_bounds(dataset)
  diff = get_diff_bounds(bounds.rows)
}
var behaviors = {
  sequence: { name: 'Sequence', fn: play_sequence },
  interval: { name: 'Intervals', fn: play_interval_sequence },
}
function pick_behavior(name){
  play_fn = behaviors[name].fn
}
function play_next(){
  let note_time = 120000 / Tone.Transport.bpm.value * note_values[nx.timing.active][0] * nx.duration.value
  setTimeout(play_next, note_time)
  let [new_i, notes] = play_fn(i, note_time)
  i = new_i
  if (recording) {
    let timing = note_values[nx.timing.active][2]
    if (timing.length) timing = timing[i % timing.length]
    recorder.addEvent(new MidiWriter.NoteEvent({ pitch: notes, duration: 't' + timing }))
  }
}
function play_sequence(i, note_time) {
  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( norm(n, min, max) * nx.multiply.value, note_time)
  return [i, [midi_note]]
}
function play_interval_sequence(i, note_time) {
  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_time)
  })
  i += 1
  return [i, notes]
}

function norm(n, min, max){
  return (n - min) / (max - min)
}
function get_diff_bounds(rows){
  const diffs = rows.map(row => {
    const row_min = Math.min.apply(Math, row)
    const row_max = Math.max.apply(Math, row)
    return row_max - row_min
  })
  const min = Math.min.apply(Math, diffs)
  const max = Math.max.apply(Math, diffs)
  return { min, max }
}
function get_bounds(dataset){
  let rows = dataset.lines
  rows.forEach(row => row.shift())
  rows = rows.map(a => a.map(n => parseFloat(n)))
  const max = rows.reduce((a,b) => {
    return b.reduce((z,bb) => {
      return Math.max(z, bb)
    }, a)
  }, -Infinity)
  const min = rows.reduce((a,b) => {
    return b.reduce((z,bb) => {
      return Math.min(z, bb)
    }, a)
  }, Infinity)
  return { rows, max, min }
}
function play(index, duration){
  // 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 ((midi || exporting) && midi_note > 127) return 0
  const note = Tone.Frequency(Math.floor(midi_note), "midi").toNote()
  if (exporting || midi) {
    duration = duration || 60000 / Tone.Transport.bpm.value
    if (! exporting) {
      midi.playNote(note, "all", { duration })
      midi.sendPitchBend(cents, "all")
    }
  } else {
    kalimba.play(freq)
  }
  return note
}

function update_value_on_change(el, id, is_int, fn) {
  const label = document.querySelector(id + ' + .val')
  const update = v => {
    label.innerHTML = is_int ? parseInt(v) : v.toFixed(2)
    fn && fn(v)
  }
  el.on('change', update)
  update(el.value)
  el.update = update
}
function update_radio_value_on_change(el, id, values, fn) {
  let old_v = el.active
  const label = document.querySelector(id + ' + .val')
  const update = v => {
    if (v === -1) {
      v = el.active = old_v
    } else {
      old_v = v
    }
    label.innerHTML = values[v][1]
    fn && fn(v)
  }
  el.on('change', update)
  update(el.active)
  el.update = update
}
function build_options(el, lists, fn) {
  Object.keys(lists).forEach(key => {
    const list = lists[key]
    const option = document.createElement('option')
    option.innerHTML = list.name
    option.value = key
    el.appendChild(option)
  })
  el.addEventListener('input', function(e){
    fn(e.target.value)
  })
}
function ready () {
  scales.build_options(document.querySelector('#scale'))
  build_options(document.querySelector('#dataset'), datasets, pick_dataset)
  build_options(document.querySelector('#behavior'), behaviors, pick_behavior)
  // nx.colorize('#f4d142')

	Tone.Transport.bpm.value = DEFAULT_BPM
  nx.tempo = new Nexus.Dial('#tempo', {
    min: 10,
    max: 300,
    step: 1,
    value: DEFAULT_BPM,
  })
  update_value_on_change(nx.tempo, '#tempo', true, v => Tone.Transport.bpm.value = v)

  nx.timing = new Nexus.RadioButton('#timing', {
    size: [400,25],
    numberOfButtons: note_values.length,
    active: 6,
  })
  update_radio_value_on_change(nx.timing, '#timing', note_values)

  nx.duration = new Nexus.Dial('#duration', {
    min: 0,
    max: 2,
    step: 0.01,
    value: 0.8,
  })
  update_value_on_change(nx.duration, '#duration', false)

  nx.offset = new Nexus.Dial('#offset', {
    min: -24,
    max: 24,
    step: 1,
    value: 0,
  })
  update_value_on_change(nx.offset, '#offset', true)

  nx.octave = new Nexus.Dial('#octave', {
    min: -4,
    max: 4,
    step: 1,
    value: 0,
  })
  update_value_on_change(nx.octave, '#octave', true)

  nx.multiply = new Nexus.Dial('#multiply', {
    min: -64,
    max: 64,
    step: 1,
    value: 7,
  })
  update_value_on_change(nx.multiply, '#multiply', true)

  nx.interval = new Nexus.Dial('#interval', {
    min: -64,
    max: 64,
    step: 1,
    value: 10,
  })
  update_value_on_change(nx.interval, '#interval', true)

  const export_midi_button = document.querySelector('#export_midi')
  export_midi_button.addEventListener('click', export_pattern_as_midi)

  const record_midi_button = document.querySelector('#record_midi')
  record_midi_button.addEventListener('click', () => {
    if (recording) {
      record_midi_button.innerHTML = 'Record MIDI'
      document.body.classList.remove('recording')
      recording = false
      const writer = new MidiWriter.Writer([recorder])
      const blob = dataURItoBlob(writer.dataUri())
      saveAs(blob, 'Recording - ' + dataset.name + '.mid')
    } else {
      record_midi_button.innerHTML = 'Save Recording'
      document.body.classList.add('recording')
      recording = true
      recorder = new MidiWriter.Track()
      recorder.setTempo(nx.tempo.value)
    }
  })

  document.querySelector('.loading').classList.remove('loading')
  play_next()
}
function export_pattern_as_midi(){
  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[nx.timing.active][2]
  exporting = true
  let midi_track = new MidiWriter.Track()
  midi_track.setTempo(nx.tempo.value)
  for (let i = 0, len = count; i < len; i++) {
    notes = play_fn(i)[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 - ' + dataset.name + '.mid')
  exporting = false
}

keys.listen(index => {
  nx.offset.value = index
  nx.offset.update(index)
})