constructor(x, y, width, height) {

    this.x = x;

    this.y = y;

    this.width = width;

    this.height = height;

  }

​

  getLeft() {

    return this.x;

  }

​

  getRight() {

    return this.x + this.width;

  }

​

  getBottom() {

    return this.y + this.height;

  }

​

  getTop() {

    return this.y;

  }

  overlaps(shape){

    // based on https://stackoverflow.com/a/4098512

    return !(this.getRight() < shape.x || 

             this.getBottom() < shape.y || 

             this.x > shape.getRight() || 

             this.y > shape.getBottom());

  }

​

  contains(x, y) {

    return x >= this.x && // check within left edge

      x <= (this.x + this.width) && // check within right edge

      y >= this.y && // check within top edge

      y <= (this.y + this.height); // check within bottom edge

  }

}