let mic, fft;

let numSamples = 20;

let bandNum;

let barHeight;

let oldX = 500;

let oldY = 500;

let dim;

let theta;

let spectrum;

let c1, c2, c3;

let circles = [];

let spectrumStart = 0.1;

let spectrumWidth = 0.3;

​

function setup() {

  createCanvas(1080, 1080);

  heatmap = createGraphics(1920, 1920);

  colorMode(HSB, 360, 100, 100, 100);

  c1 = color(63, 100, 82, 100);

  c2 = color(62, 50, 30);

  c3 = color(62, 100, 33);

​

  mic = new p5.AudioIn();

  mic.start();

  fft = new p5.FFT();

  fft.setInput(mic);

}

​

function draw() {

  fill(255, 100);

  rect(0, 0, width, height);

  fft.smooth(0.8);

  spectrum = fft.analyze();

  //console.log(spectrum.length);

  heatmap.colorMode(HSB, 360, 100, 100, 100);

  //heatmap.clear();

  heatmap.noStroke();

  heatmap.fill(0);

  drawDot(heatmap, 64);

  blendMode(BLEND);

  image(heatmap, 0, 0);

}

​

function drawDot(layer, sampleCount) {

  let maxVal = 0;

  let maxIndex = 0;

  for (i = 0; i < sampleCount; i++) {

    bandNum = Math.floor((spectrum.length * spectrumStart) + (spectrum.length * spectrumWidth) / sampleCount * i);

    barHeight = fft.getEnergy(bandNum) * 2;

    if (barHeight > maxVal) {

      maxVal = barHeight;

      maxIndex = i;

    }

  }

  let varience = random(2 * Math.PI / sampleCount)*2;

  theta = (2 * Math.PI / sampleCount * maxIndex); // + varience;

​

  let maxR = min(width / 2, height / 2) * 1;

  let maxDotR = min(width / 2, height / 2) * 2;

​

  let finalRad = maxVal + random(-240, 40);

​

  let x = (maxR - finalRad) * cos(theta) + width / 2;

  let y = (maxR - finalRad) * sin(theta) + height / 2;

​

  drawGradient(layer, x, y, maxVal*0.2, c1);

}

​

function drawGradient(layer, x, y, rad, col) {

  if (rad > 0) {

    let xxx = int(x);

    let yyy = int(y);

    let radius = int(rad);

    let c = col;

    let alph = 100 / radius * 0.1;

    let subLayer = createGraphics(radius * 2, radius * 2);

    subLayer.colorMode(HSB, 360, 100, 100, 100);

    c.setAlpha(alph);

    for (let r = radius; r > 0; --r) {

      c.setAlpha(alph);

      subLayer.noFill();

      subLayer.strokeWeight(1);

      subLayer.stroke(c);

      subLayer.ellipse(radius, radius, r, r);

      alph = alph + 100 / radius * 0.1;

    }

    layer.blendMode(DODGE);

    layer.image(subLayer, x - radius, y - radius);

  }

}