let angle = 0;

let radius = 30; //distance of cirle

​

function setup() {

  createCanvas(400, 400);

​

  describe('A circle rotates around the mouse position.');

}

​

function draw() {

  background(240);

​

  // center to mouse

  translate(mouseX, mouseY);

​

  // make circle rotate

  let x = cos(angle) * radius;

  let y = sin(angle) * radius;

​

  // angle increase

  angle += 0.05; // speed

​

  // circle

  fill('black');

  ellipse(x, y, 10, 10);

}