constructor(w, x, m, b, k, l) {

    this.wallPos = w;

    this.pos = x;

    this.vel = 0;

    this.acc = 0;

    this.x = 0;

    this.m = m;

    this.b = b;

    this.k = k;

    this.l = l;

    this.pMouse = 0;

  }

  springForce() {

    this.x = this.pos - this.l;

    this.acc = -this.k / this.m * this.x - this.b / this.m * this.vel;

  }

  mouseInput() {

    if (mouseIsPressed && mouseY > 0 && mouseY < height) {

      this.vel = 0;

      this.pos += mouseX - this.pMouse;

    }

    this.pMouse = mouseX;

  }

  update() {

    this.springForce();

    this.vel += this.acc;

    this.mouseInput();

    this.pos += this.vel;

    this.acc = 0;

  }

  show() {

    push();

    strokeWeight(3);

    fill(0, 0, 255);

    noStroke();

    rectMode(CENTER);

    rect(this.pos, height / 2, 35, 70);

    if (this.x < 0) {

      stroke(255, 0, 0);

    } else {

      stroke(0 ,255, 0);

    }

    let d = (this.pos - this.wallPos) / 16;

    line(this.wallPos, height / 2, this.wallPos + d, height / 2);

    line(this.wallPos + d, height / 2, this.wallPos + 2 * d, height / 2 - 20);

    line(this.wallPos + 2 * d, height / 2 - 20, this.wallPos + 4 * d, height / 2 + 20);

    line(this.wallPos + 4 * d, height / 2 + 20, this.wallPos + 6 * d, height / 2 - 20);

    line(this.wallPos + 6 * d, height / 2 - 20, this.wallPos + 8 * d, height / 2 + 20);

    line(this.wallPos + 8 * d, height / 2 + 20, this.wallPos + 10 * d, height / 2 - 20);

    line(this.wallPos + 10 * d, height / 2 - 20, this.wallPos + 12 * d, height / 2 + 20);

    line(this.wallPos + 12 * d, height / 2 + 20, this.wallPos + 14 * d, height / 2 - 20);

    line(this.wallPos + 14 * d, height / 2 - 20, this.wallPos + 15 * d, height / 2);

    line(this.wallPos + 15 * d, height / 2, this.wallPos + 16 * d, height / 2);

    pop();

  }

}