​

function setup() {

  createCanvas(400, 400);

​

  for (let i = 0; i < 2; i++) {

    let angle = random(TWO_PI);

    let speed = random(1, 3);

    balls.push(

      new Ball(

        width / 2,

        height / 2,

        cos(angle) * speed,

        sin(angle) * speed,

        false

      )

    );

  }

}

​

class Ball {

  constructor(x, y, xspeed, yspeed, followsMouse) {

    this.x = x;

    this.y = y;

    this.xSpeed = xspeed;

    this.ySpeed = yspeed;

    this.followsMouse = followsMouse;

  }

​

  move() {

    if (this.followsMouse) {

      let speed = 0.5;

      let angle = atan2(mouseY - this.y, mouseX - this.x);

      this.xSpeed = cos(angle) * speed;

      this.ySpeed = sin(angle) * speed;

    }

    this.x += this.xSpeed;

    this.y += this.ySpeed;

  }

​

  bounce() {

    if (this.x <= 0 || this.x >= width) {

      this.xSpeed *= -1;

    }

    if (this.y <= 0 || this.y >= height) {

      this.ySpeed *= -1;

    }

  }

​

  display() {

    ellipse(this.x, this.y, 50, 50);

  }

}

​

function draw() {

  background(220);

​

  for (let ball of balls) {

    ball.move();

    ball.bounce();

    ball.display();

  }

}

​

function mousePressed() {

  balls.push(new Ball(mouseX, mouseY, 0, 0, true));

}

​