​

WebMidi.enable()

  .then(onEnabled)

  .catch((err) => alert(err));

​

function onEnabled() {

  // Inputs

  WebMidi.inputs.forEach((input) =>

    console.log(input.manufacturer, input.name)

  );

​

  // Outputs

  WebMidi.outputs.forEach((output) =>

    console.log(output.manufacturer, output.name)

  );

}

​

// dial ctrl values as encoded into BeatStep firmware.

dialMap = [10, 74, 71, 76, 77, 93, 73, 75, 114, 18, 19, 16, 17, 91, 79, 72];

let padMap = [44, 45, 46, 47, 48, 49, 50, 51, 36, 37, 38, 39, 40, 41, 42, 43];

class BeatStep {

  constructor(type) {

    this.device = type;

    this.init(this);

    this.avg = 33;

    this.dialsHis = [];

    this.dialsAvg = [];

    this.encoder = 0;

    this.dials = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];

    this.notesOn = [];

    this.MIDIon = [];

    this.pads = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];

    this.play = 0;

    this.synth = false;

    this.print = false;

    this.stop = 0;

    this.initAvg();

    this.initDom();

  }

  initAvg() {

    for (let i = 0; i < 16; i++) {

      this.dialsHis[i] = new Array();

    }

  }

  updatePad(data) {

    let n = data[1];

    let v = data[2];

    for (let i = 0; i < 16; i++) {

      if (n == padMap[i]) {

        this.pads[i] = v;

      }

    }

  }

  updateCtrl(data) {

    let n = data[1];

    let v = data[2];

    for (let i = 0; i < 16; i++) {

      if (n == dialMap[i]) {

        this.dials[i] = v;

      }

    }

    if (n == 7) {

      this.encoder = v;

    }

  }

  avgCtrl() {

    if (this.avg > 1) {

      for (let i = 0; i < 16; i++) {

        this.dialsHis[i].push(this.dials[i]);

        if (this.dialsHis[i].length >= this.avg) {

          this.dialsHis[i].splice(0, 1);

        }

​

        let t = 0;

        for (let s = 0; s < this.dialsHis[i].length; s++) {

          t += this.dialsHis[i][s];

        }

        t /= this.dialsHis[i].length;

        this.dialsAvg[i] = t;

      }

    }

  }

  updateSeq(data) {

    let n = data[1];

    let v = data[2];

  }

  initDom() {

    this.dialsDom = createP("");

    this.notes = createP("");

  }

  display() {

    this.dialsDom.html("dials = " + this.dials);

    //  this.dialsDom.html("notes on = " + this.notesOn);

  }

  init(ref) {

    WebMidi.enable(function (err) {

      //check if WebMidi.js is enabled

​

      if (err) {

        console.log("WebMidi could not be enabled.", err);

      } else {

        console.log("WebMidi enabled!");

      }

    })

      .then(function () {

        //name our visible MIDI input and output ports

        console.log("---");

        console.log("Inputs Ports: ");

        for (let i = 0; i < WebMidi.inputs.length; i++) {

          console.log(i + ": " + WebMidi.inputs[i].name);

        }

      })

      .then(function () {

        // take JS object argument to look for device name

        let index = WebMidi.inputs.findIndex((x) => x.name === ref.device);

        ref.inputSoftware = WebMidi.inputs[index];

​

        if (ref.inputSoftware) {

          console.log("connected to " + ref.device);

        } else {

          console.log("error connecting to MIDI device");

        }

      })

      .then(function () {

        // Listen to control change message on all channels

        ref.inputSoftware.addListener("controlchange", "all", function (e) {

          ref.ctrl = e;

          if (ref.print) {

            console.log(e.data);

          }

          ref.updateCtrl(e.data);

          ref.display();

        });

​

        // Listen to control change message on all channels

        ref.inputSoftware.addListener("noteon", "all", function (e) {

          ref.MIDIon.push(e.data[1]);

          ref.notesOn.push(e.note.identifier);

          if (e.data[1] >= 36 && e.data[1] <= 51) {

            ref.updatePad(e.data);

          }

​

          if (ref.print) {

            console.log(e.note.identifier, "on", e.message.channel);

            console.log(e.data[1], "on");

          }

          if (ref.synth) {

            polySynth.noteAttack(e.note.identifier, ref.synthVel);

          }

        });

​

        // Listen to control change message on all channels

        ref.inputSoftware.addListener("noteoff", "all", function (e) {

           if (e.data[1] >= 36 && e.data[1] <= 51) {

            ref.updatePad(e.data);

          }

          if (ref.print) {

            console.log(e.note.identifier, "off", e.message.channel);

​

            console.log(e.data[1], "off");

          }

          let match = (element) => element == e.noteIdentifier;

          let index = ref.notesOn.findIndex(match);

          ref.notesOn.splice(index, 1);

​

          if (ref.synth) {

            polySynth.noteRelease(e.note.identifier, ref.synthVel);

          }

​

          match = (element) => element == e.data[1];

          index = ref.notesOn.findIndex(match);

          ref.MIDIon.splice(index, 1);

        });

      });

​

    //

    //end of MIDI setup

    //

  }

}