constructor() {

    this.pos = createVector(width/2, height/2);

  }

  show() {

    fill(255);

    stroke(255)

    strokeWeight(8);

    point(this.pos.x, this.pos.y);

  }

  update() {

    this.vel = createVector(randomGaussian(0, 4), randomGaussian(0, 4));

    if (this.pos.x > width || this.pos.x < 0) {

      this.pos.x = this.pos.x

      this.vel.x = this.vel.x * -1

    } else if (this.pos.y > height || this.pos.y < 0) {

      this.pos.y = this.pos.y 

      this.vel.y = this.vel.y * -1

    }

    this.pos.add(this.vel);

  }

}

​

function setup() {

  createCanvas(400, 400);

  walker = new Walker();

}

​

function draw() {

  background(20);

  walker.update()

  walker.show()

}