constructor(size, speed) {

    this.size = createVector(size, size);

    this.pos = createVector(random(width - size), random(height - size));

    this.vel = p5.Vector.fromAngle(PI * .25, speed);

    this.newColor();

  }

  newColor() {

    this.color = createVector(random(), random(), random()).setMag(255);

  }

​

  update() {

        this.pos.add(this.vel);

    const left   = this.pos.x < 0;

    const top    = this.pos.y < 0;

    const right  = this.pos.x + this.size.x >= width;

    const bottom = this.pos.y + this.size.y >= height;

    const horz   = left || right;

    const vert   = top  || bottom;

    const any    = horz || vert;

    if (horz) {

      this.pos.x = (left ? 0 : (width - this.size.x) * 2) - this.pos.x;

            this.vel.x *= -1;

    }

    if (vert) {

      this.pos.y = (top ? 0 : (height - this.size.y) * 2) - this.pos.y;

            this.vel.y *= -1;

    }

    if (any) this.newColor();

    return this;

  }

​

  render() {

    fill(this.color.array());

        rect(this.pos.x, this.pos.y, this.size.x, this.size.y);

  }

}