coord.js

define(function () {

  /** Coordinate object. Represents a point in 2-space.
   */
  function Coord(opt) {
    this.x = 0;
    this.y = 0;
    this.initialize(opt);
  //  this.x = (x || 0);
  //  this.y = (y || 0);
  }


  Coord.prototype.initialize = function (opt) {
    var key = null,
        default_args = {
          x : 0,
          y : 0
        };

    opt = (opt || default_args);

    for(key in default_args) {
      if(typeof opt[key] == "undefined") opt[key] = default_args[key];
    }

    // opt[] has all the data - user provided and optional.
    for(key in opt) {
      //console.log(key + " = " + opt[key]);
      this[key] = opt[key];
    }
  };


  /** Move this Coord to a new (x, y) location.
   * @param {Number} x
   * @param {Number} y
   */
  Coord.prototype.move = function (x, y) {
    this.x = x;
    this.y = y;

    return this;
  };

  /** Add [Coord] other to this and return the result.
   * @param {Coord} other
   */
  Coord.prototype.plus = function (other) {
    return new Coord({x : this.x + other.x, y : this.y + other.y});
  };

  /** Subtracts [Coord] other from this and return the result.
   * @param {Coord} other
   */
  Coord.prototype.minus = function (other) {
    return new Coord({x : this.x - other.x, y : this.y - other.y});
  };

  /** Scales this [Coord] by the factor specified.
   * @param {Number} scale
   */
  Coord.prototype.scale = function (scale) {
    return new Coord({x : this.x * scale, y : this.y * scale});
  };

  /** Returns distance from this [Coord] to [Coord] b.
   * @param {Coord}
   */
  Coord.prototype.dist = function (b) {
    return Math.sqrt((this.x - b.x)*(this.x - b.x) + (this.y - b.y)*(this.y - b.y));
  };

  /** Returns the midpoint of this [Coord] and [Coord] b.
   * @param {Coord}
   */
  Coord.prototype.midpoint = function (b) {
    return new Coord({x : (this.x + b.x) / 2, y : (this.y + b.y) / 2});
  //  return new Coord((this.x + b.x) / 2, (this.y + b.y) / 2);
  };


  return Coord;
});