class Particle extends p5.Vector {

  constructor(x, y) {

    super(x,y);

    // this.pos = createVector(x, y);

    this.vel = p5.Vector.random2D();

    this.vel.mult(random(0.5, 2));

    this.acc = createVector(0, 0);

    this.r = 4;

    this.lifetime = 255;

  }

​

  finished() {

    return this.lifetime < 0;

  }

​

  applyForce(force) {

    this.acc.add(force);

  }

​

  edges() {

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

      this.pos.y = height - this.r;

      this.vel.y *= -1;

    }

​

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

      this.pos.x = width - this.r;

      this.vel.x *= -1;

    } else if (this.pos.x <= this.r) {

      this.pos.x = this.r;

      this.vel.x *= -1;

    }

  }

​

  update() {

    this.vel.add(this.acc);

    this.add(this.vel);

    this.acc.set(0, 0);

​

    this.lifetime -= 5;

  }

​

  show() {

    stroke(255, this.lifetime);

    strokeWeight(2);

    fill(255, this.lifetime);

​

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

  }

}

​