// Daniel Shiffman

// http://natureofcode.com

​

// PolarToCartesian

// Convert a polar coordinate (r,theta) to cartesian (x,y):

// x = r * cos(theta)

// y = r * sin(theta)

​

let r;

let theta;

​

function setup() {

  createCanvas(640, 360);

  // Initialize all values

  r = 0;

  theta = 0;

  background(51);

}

​

function draw() {

​

  // Translate the origin point to the center of the screen

  translate(width / 2, height / 2);

​

  // Convert polar to cartesian

  let x = r * cos(theta);

  let y = r * sin(theta);

​

  // Draw the ellipse at the cartesian coordinate

  ellipseMode(CENTER);

  fill(127);

  noStroke();

  // stroke(255);

  // strokeWeight(2);

  //line(0, 0, x, y);

  ellipse(x, y, 10, 10);

​

  // Increase the angle over time

  r += 0.1;

  theta += 0.02;

}