intel edison synthesizer

index.js

"use strict";

var express = require("express");
var app = express();
var http = require("http").Server(app);
var io = require("socket.io")(http);
var os = require("os");
var flock = require("flocking");

/* Server */

app.use(express.static("static"));

app.get("/", function (req,res) {
    res.sendFile(__dirname + "/static/keyboard.html");
});

var server = http.listen(3000, function () {
    /* get ip address */
    var interfaces = os.networkInterfaces();
    var wlan = interfaces["wlan0"];
    var addr, host, port;

    addr = server.address();
    port = addr.port;

    if (wlan && wlan.length > 0) {
        host = wlan[0].address;
    } else {
        host = addr.address;
    }

    console.log("keyboard is at http://" + host + ":" + port + "/");
});

io.on("connection", function (socket) {
    console.log("user connected");
    socket.on("pressStart", pressStart);
    socket.on("pressEnd", pressEnd);
});

/* Synth */
var enviro = flock.init();
var notes = {
    "c1":      440 * Math.pow(2, -9 / 12),
    "c#1":    440 * Math.pow(2, -8 / 12),
    "d1":      440 * Math.pow(2, -7 / 12),
    "d#1":    440 * Math.pow(2, -6 / 12),
    "e1":      440 * Math.pow(2, -5 / 12),
    "f1":      440 * Math.pow(2, -4 / 12),
    "f#1":    440 * Math.pow(2, -3 / 12),
    "g1":      440 * Math.pow(2, -2 / 12),
    "g#1":    440 * Math.pow(2, -1 / 12),
    "a1":      440 * Math.pow(2,  0 / 12),
    "a#1":    440 * Math.pow(2,  1 / 12),
    "b1":      440 * Math.pow(2,  2 / 12),
    "c2":      440 * Math.pow(2,  3 / 12),
    "c#2":    440 * Math.pow(2,  4 / 12),
    "d2":      440 * Math.pow(2,  5 / 12),
    "d#2":    440 * Math.pow(2,  6 / 12),
    "e2":      440 * Math.pow(2,  7 / 12),
};

/* 以下変更 */

var sources_num = 5; /* max */
var sources = [];
var sources_used = [];
var s = flock.synth({
    synthDef: {
        ugen: "flock.ugen.sum",
        sources: (function () {
            for (var i = 0; i < sources_num; i++) {
                sources_used[i] = null;
                sources[i] = {
                    id: "osc" + i,
                    ugen: "flock.ugen.sin",
                    freq: 880,
                    mul: {
                        ugen: "flock.ugen.envGen",
                        envelope: {
                            type: "flock.envelope.adsr",
                            attack: 0,
                            decay: 1.0,
                            peak: 0.15,
                            sustain: 1.0,
                            release: 1.0,
                        },
                        gate: 0.0
                    }
                };
            }
            return sources;
        })()
    }
});

enviro.play();

function pressStart(key) {
    if (! (key in notes)) {
        console.log("invalid key", key);
        return;
    }

    for (var i = 0; i < sources_num; i++) {
        if (sources_used[i] == null) {
            sources_used[i] = key;
            s.set("osc" + i + ".freq", notes[key]);
            s.set("osc" + i + ".mul.gate", 1.0);
            console.log("start", key, "osc: ", i);
            break;
        }
    }
}

function pressEnd(key) {
    if (! (key in notes)) {
        console.log("invalid key", key);
        return;
    }
    for (var i = 0; i < sources_num; i++) {
        if (sources_used[i] == key) {
            s.set("osc" + i + ".mul.gate", 0.0);
            sources_used[i] = null;
            console.log("end", key, "osc: ", i);
            break;
        }
    }
}