let y = [];

let fourierX;

let fourierY;

let time = 0;

let path = [];

​

function setup() {

  createCanvas(600, 400);

  let angle;

  for (let i = 0; i < 500; i++) {

    x[i] = 200 * noise(i / 50);

    y[i] = 200 * noise(i / 50 + 1000);

  }

​

  fourierX = dft(x);

  fourierY = dft(y);

​

  fourierX.sort((a, b) => b.amp - a.amp);

  fourierY.sort((a, b) => b.amp - a.amp);

}

​

function epiCycles(x, y, rotation, fourier) {

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

    let prevx = x;

    let prevy = y;

​

    let freq = fourier[i].freq;

    let radius = fourier[i].amp;

    let phase = fourier[i].phase;

    x += radius * cos(freq * time + phase + rotation);

    y += radius * sin(freq * time + phase + rotation);

​

    stroke(255, 100);

    noFill();

    ellipse(prevx, prevy, radius * 2);

    stroke(255);

    line(prevx, prevy, x, y);

  }

  return createVector(x, y);

}

​

function draw() {

  background(0);

​

  let vx = epiCycles(300, 50, 0, fourierX);

  let vy = epiCycles(50, 200, HALF_PI, fourierY);

  let v = createVector(vx.x, vy.y);

  path.unshift(v);

​

  line(vx.x, vx.y, v.x, v.y);

  line(vy.x, vy.y, v.x, v.y);

  beginShape();

  noFill();

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

    vertex(path[i].x, path[i].y);

  }

  endShape();

​

  const dt = TWO_PI / fourierY.length;

  time += dt;

  if (time > TWO_PI) {

    time = 0;

    path = [];

  }

​

  // if (wave.length > 250) {

  //   wave.pop();

  // }

}