constructor() {

    this.hue = random(255);

    this.firework = new Particle(random(width), height, this.hue, true);

    this.exploded = false;

    this.particles = [];

  }

​

  done() {

    if (this.exploded && this.particles.length === 0) {

      return true;

    } else {

      return false;

    }

  }

​

  update() {

    if (!this.exploded) {

      this.firework.applyForce(gravity);

      this.firework.update();

​

      if (this.firework.vel.y >= 0) {

        this.exploded = true;

        this.explode();

      }

    }

​

    for (let i = this.particles.length - 1; i >= 0; i--) {

      this.particles[i].applyForce(gravity);

      this.particles[i].update();

​

      if (this.particles[i].done()) {

        this.particles.splice(i, 1);

      }

    }

  }

​

  explode() {

    for (let i = 0; i < 100; i++) {

      const p = new Particle(this.firework.pos.x, this.firework.pos.y, this.hue, false);

      this.particles.push(p);

    }

  }

​

  show() {

    if (!this.exploded) {

      this.firework.show();

    }

​

    for (var i = 0; i < this.particles.length; i++) {

      this.particles[i].show();

    }

  }

}