createCanvas(800, 400);

}

​

let r = 30;

let x = r;

let y = 30;

let dx = 10;

let dy = 5;

let ddy = 9;

​

function draw() {

  background(0);

  stroke(255);

  strokeWeight(1);

  ellipse(x,y,r,r);

  x += dx;

  y += dy;

  dy += ddy;

  if (x > width - r) {

    x = -r;

  }

  if (y > height - r) {

    y = height - r;

    dy = -60;

  }

}