​

function setup() {

  createCanvas(400, 400);

  r = 100;

  theta = -PI/4;

}

​

function draw() {

  background(0);

  translate(width / 2, height / 2);

  let x = r * cos(theta);

  let y = r * sin(theta);

  theta += 0.1;

​

  strokeWeight(8);

  stroke(255);

  point(x,y);

  strokeWeight(1);

  line(0,0,x,y);

​

}