class Emitter {

  constructor(x, y) {

    this.position = createVector(x, y);

    this.particles = [];

  }

​

  emit(num) {

    for (let i = 0; i < num; i++) {

      this.particles.push(new Particle(this.position.x, this.position.y));

    }

  }

​

  update() {

    for (let particle of this.particles) {

      let gravity = createVector(0, 0.2);

      particle.applyForce(gravity);

      particle.update();

    }

​

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

      if (this.particles[i].finished()) {

        this.particles.splice(i, 1);

      }

    }

  }

​

  show() {

    for (let particle of this.particles) {

      particle.show();

    }

  }

}

​