constructor(x, y) {

    this.position = createVector(x, y);

    this.velocity = createVector(0, 0);

    this.acceleration = createVector(0, 0);

    this.r = 4;

    this.lifetime = 255;

  }

​

  applyForce(force) {

    this.acceleration.add(force);

  }

​

  edges() {

    if (this.position.y >= height - this.r) {

      this.position.y = height - this.r;

      this.velocity.y *= -1;

    }

​

    if (this.position.x >= width - this.r) {

      this.position.x = width - this.r;

      this.velocity.x *= -1;

    }

​

    if (this.position.x <= this.r) {

      this.position.x = this.r;

      this.velocity.x *= -1;

    }

  }

​

  update() {

    this.velocity.add(this.acceleration);

    this.position.add(this.velocity);

    this.acceleration.set(0, 0); //resetting acceleration to zero at every fraame

    this.lifetime -=1;

  }

​

  display() {

    stroke(255, this.lifetime);

    strokeWeight(2);

    fill(200, this.lifetime);

    ellipse(this.position.x, this.position.y, this.r * 2);

  }

}

​