// Copyright (c) 2001-2010, Purdue University. All rights reserved.// Copyright (C) 2015 Apple Inc. All rights reserved.//// Redistribution and use in source and binary forms, with or without// modification, are permitted provided that the following conditions are met:// * Redistributions of source code must retain the above copyright// notice, this list of conditions and the following disclaimer.// * Redistributions in binary form must reproduce the above copyright// notice, this list of conditions and the following disclaimer in the// documentation and/or other materials provided with the distribution.// * Neither the name of the Purdue University nor the// names of its contributors may be used to endorse or promote products// derived from this software without specific prior written permission.//// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.function Vector2D(x, y) {this.x = x;this.y = y;}Vector2D.prototype.plus = function(other) {return new Vector2D(this.x + other.x,this.y + other.y);};Vector2D.prototype.minus = function(other) {return new Vector2D(this.x - other.x,this.y - other.y);};Vector2D.prototype.toString = function() {return "[" + this.x + ", " + this.y + "]";};Vector2D.prototype.compareTo = function(other) {var result = compareNumbers(this.x, other.x);if (result)return result;return compareNumbers(this.y, other.y);};