JavaのMidiChannelを参考にしたWebMIDIのラッパー

MidiChannel.js

function MidiChannel(midiOutput, channel) {
  this.output = midiOutput;
  this.channel = channel;
}

MidiChannel.prototype = {
  /*
   * Channel voice messages
   */
  noteOff: function(noteNumber, velocity, timestamp) {
    this.output.send([0x80 | this.channel, noteNumber, velocity], timestamp);
  },
  noteOn: function(noteNumber, velocity, timestamp) {
    this.output.send([0x90 | this.channel, noteNumber, velocity], timestamp);
  },
  polyPressure: function(noteNumber, pressure, timestamp) {
    this.output.send([0xA0 | this.channel, noteNumber, pressure], timestamp)
  },
  controlChange: function(controller, value, timestamp) {
    this.output.send([0xB0 | this.channel, controller, value], timestamp)
  },
  programChange: function(program, timestamp) {
    this.output.send([0xC0 | this.channel, program], timestamp)
  },
  channelPressure: function(pressure, timestamp) {
    this.output.send([0xD0 | this.channel, pressure], timestamp)
  },
  pitchBend: function(bend, timestamp) {
    this.output.send([0xE0 | this.channel, bend & 0x7F, bend >> 7 & 0x7F], timestamp);
  },

  /*
   * Channel mode messages
   */
  allSoundOff: function(timestamp) {
    this.output.send([0xB0 | this.channel, 0x78, 0x00], timestamp)
  },
  resetAllController: function(timestamp) {
    this.output.send([0xB0 | this.channel, 0x79, 0x00], timestamp)
  },
  localControl: function(on, timestamp) {
    this.output.send([0xB0 | this.channel, 0x7A, on ? 0x7F : 0x00], timestamp)
  },
  allNotesOff: function(timestamp) {
    this.output.send([0xB0 | this.channel, 0x7B, 0x00], timestamp)
  },
  omni: function(on, timestamp) {
    this.output.send([0xB0 | this.channel, on ? 0x7C : 0x7D, 0x00], timestamp)
  },
  poly: function(on, timestamp) {
    this.output.send([0xB0 | this.channel, on ? 0x7E : 0x7F, 0x00], timestamp)
  }
};