let mic, sound;
let audio = document.getElementById('audio');
let fft;
let currentLine = 0;
var file;


function preload() {
    file = loadSound(audio.src);
}

function setup() {
    createCanvas(windowWidth, windowHeight);

    var smoothing = 0.6;
    var bins = 2048;
    fft = new p5.FFT(smoothing, bins);
    fft.setInput(file);

    file.loop();

    background(0);
}

function draw() {
    var spectrum = fft.analyze();

    // iterate thru current freq spectrum
    for (var i = 0; i < spectrum.length; i++) {
        var value = spectrum[i];

        var c = value;
        fill(c);
        noStroke();

        var hauteurDuRectangle = height / (spectrum.length);
        var y = map(i, 0, spectrum.length, height - hauteurDuRectangle, 0);
        rect(currentLine, y, 4, hauteurDuRectangle);
    }

    currentLine = currentLine + 4;
    if (currentLine > width) currentLine = 0;

}


function logScale(index, total, opt_base) {
    var base = opt_base || 2;
    var logmax = logBase(total + 1, base);
    var exp = logmax * index / total;
    return Math.round(Math.pow(base, exp) - 1);
}

function logBase(val, base) {
    return Math.log(val) / Math.log(base);
}