let dx, dy;

​

function setup() {

  createCanvas(800, 600);

  x = width / 2;

  y = height / 2;

  w = width / 5;

  h = height / 5;

  rectMode(CENTER);

}

​

function draw() {

  background(20);

  noStroke();

  fill(255, 10, 100);

  rect(x, y, w, h);

​

  dx = mouseX - x;

  dy = mouseY - y;

  x = x + dx * 0.05;

  y = y + dy * 0.05;

​

}