clipper.js

/*******************************************************************************
 *                                                                              *
 * Author    :  Angus Johnson                                                   *
 * Version   :  6.4.2                                                           *
 * Date      :  27 February 2017                                                *
 * Website   :  http://www.angusj.com                                           *
 * Copyright :  Angus Johnson 2010-2017                                         *
 *                                                                              *
 * License:                                                                     *
 * Use, modification & distribution is subject to Boost Software License Ver 1. *
 * http://www.boost.org/LICENSE_1_0.txt                                         *
 *                                                                              *
 * Attributions:                                                                *
 * The code in this library is an extension of Bala Vatti's clipping algorithm: *
 * "A generic solution to polygon clipping"                                     *
 * Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63.             *
 * http://portal.acm.org/citation.cfm?id=129906                                 *
 *                                                                              *
 * Computer graphics and geometric modeling: implementation and algorithms      *
 * By Max K. Agoston                                                            *
 * Springer; 1 edition (January 4, 2005)                                        *
 * http://books.google.com/books?q=vatti+clipping+agoston                       *
 *                                                                              *
 * See also:                                                                    *
 * "Polygon Offsetting by Computing Winding Numbers"                            *
 * Paper no. DETC2005-85513 pp. 565-575                                         *
 * ASME 2005 International Design Engineering Technical Conferences             *
 * and Computers and Information in Engineering Conference (IDETC/CIE2005)      *
 * September 24-28, 2005 , Long Beach, California, USA                          *
 * http://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf              *
 *                                                                              *
 *******************************************************************************/
/*******************************************************************************
 *                                                                              *
 * Author    :  Timo                                                            *
 * Version   :  6.4.2.2 (FPoint)                                                *
 * Date      :  8 September 2017                                                *
 *                                                                              *
 * This is a translation of the C# Clipper library to Javascript.               *
 *                                                                              *
 *******************************************************************************/
(function ()
{
	"use strict";
	var ClipperLib = {};
	ClipperLib.version = '6.4.2.2';

	//UseLines: Enables open path clipping. Adds a very minor cost to performance.
	ClipperLib.use_lines = true;

	//ClipperLib.use_xyz: adds a Z member to FPoint. Adds a minor cost to performance.
	ClipperLib.use_xyz = false;

	var isNode = false;
	if (typeof module !== 'undefined' && module.exports)
	{
		module.exports = ClipperLib;
		isNode = true;
	}
	else
	{
		if (typeof (document) !== "undefined") window.ClipperLib = ClipperLib;
		else self['ClipperLib'] = ClipperLib;
	}
	var navigator_appName;
	if (!isNode)
	{
		var nav = navigator.userAgent.toString().toLowerCase();
		navigator_appName = navigator.appName;
	}
	else
	{
		var nav = "chrome"; // Node.js uses Chrome's V8 engine
		navigator_appName = "Netscape"; // Firefox, Chrome and Safari returns "Netscape", so Node.js should also
	}
	// Browser test to speedup performance critical functions
	var browser = {};

	if (nav.indexOf("chrome") != -1 && nav.indexOf("chromium") == -1) browser.chrome = 1;
	else browser.chrome = 0;
	if (nav.indexOf("chromium") != -1) browser.chromium = 1;
	else browser.chromium = 0;
	if (nav.indexOf("safari") != -1 && nav.indexOf("chrome") == -1 && nav.indexOf("chromium") == -1) browser.safari = 1;
	else browser.safari = 0;
	if (nav.indexOf("firefox") != -1) browser.firefox = 1;
	else browser.firefox = 0;
	if (nav.indexOf("firefox/17") != -1) browser.firefox17 = 1;
	else browser.firefox17 = 0;
	if (nav.indexOf("firefox/15") != -1) browser.firefox15 = 1;
	else browser.firefox15 = 0;
	if (nav.indexOf("firefox/3") != -1) browser.firefox3 = 1;
	else browser.firefox3 = 0;
	if (nav.indexOf("opera") != -1) browser.opera = 1;
	else browser.opera = 0;
	if (nav.indexOf("msie 10") != -1) browser.msie10 = 1;
	else browser.msie10 = 0;
	if (nav.indexOf("msie 9") != -1) browser.msie9 = 1;
	else browser.msie9 = 0;
	if (nav.indexOf("msie 8") != -1) browser.msie8 = 1;
	else browser.msie8 = 0;
	if (nav.indexOf("msie 7") != -1) browser.msie7 = 1;
	else browser.msie7 = 0;
	if (nav.indexOf("msie ") != -1) browser.msie = 1;
	else browser.msie = 0;

	// Here starts the actual Clipper library:
	// Helper function to support Inheritance in Javascript
	var Inherit = function (ce, ce2)
	{
		var p;
		if (typeof (Object.getOwnPropertyNames) === 'undefined')
		{
			for (p in ce2.prototype)
				if (typeof (ce.prototype[p]) === 'undefined' || ce.prototype[p] === Object.prototype[p]) ce.prototype[p] = ce2.prototype[p];
			for (p in ce2)
				if (typeof (ce[p]) === 'undefined') ce[p] = ce2[p];
			ce.$baseCtor = ce2;
		}
		else
		{
			var props = Object.getOwnPropertyNames(ce2.prototype);
			for (var i = 0; i < props.length; i++)
				if (typeof (Object.getOwnPropertyDescriptor(ce.prototype, props[i])) === 'undefined') Object.defineProperty(ce.prototype, props[i], Object.getOwnPropertyDescriptor(ce2.prototype, props[i]));
			for (p in ce2)
				if (typeof (ce[p]) === 'undefined') ce[p] = ce2[p];
			ce.$baseCtor = ce2;
		}
	};

	/**
	* @constructor
	*/
	ClipperLib.Path = function ()
	{
		return [];
	};

	ClipperLib.Path.prototype.push = Array.prototype.push;

	/**
	* @constructor
	*/
	ClipperLib.Paths = function ()
	{
		return []; // Was previously [[]], but caused problems when pushed
	};

	ClipperLib.Paths.prototype.push = Array.prototype.push;

	// PolyTree & PolyNode start
	/**
	* @suppress {missingProperties}
	*/
	ClipperLib.PolyNode = function ()
	{
		this.m_Parent = null;
		this.m_polygon = new ClipperLib.Path();
		this.m_Index = 0;
		this.m_jointype = 0;
		this.m_endtype = 0;
		this.m_Childs = [];
		this.IsOpen = false;
	};

	ClipperLib.PolyNode.prototype.IsHoleNode = function ()
	{
		var result = true;
		var node = this.m_Parent;
		while (node !== null)
		{
			result = !result;
			node = node.m_Parent;
		}
		return result;
	};

	ClipperLib.PolyNode.prototype.ChildCount = function ()
	{
		return this.m_Childs.length;
	};

	ClipperLib.PolyNode.prototype.Contour = function ()
	{
		return this.m_polygon;
	};

	ClipperLib.PolyNode.prototype.AddChild = function (Child)
	{
		var cnt = this.m_Childs.length;
		this.m_Childs.push(Child);
		Child.m_Parent = this;
		Child.m_Index = cnt;
	};

	ClipperLib.PolyNode.prototype.GetNext = function ()
	{
		if (this.m_Childs.length > 0)
			return this.m_Childs[0];
		else
			return this.GetNextSiblingUp();
	};

	ClipperLib.PolyNode.prototype.GetNextSiblingUp = function ()
	{
		if (this.m_Parent === null)
			return null;
		else if (this.m_Index === this.m_Parent.m_Childs.length - 1)
			return this.m_Parent.GetNextSiblingUp();
		else
			return this.m_Parent.m_Childs[this.m_Index + 1];
	};

	ClipperLib.PolyNode.prototype.Childs = function ()
	{
		return this.m_Childs;
	};

	ClipperLib.PolyNode.prototype.Parent = function ()
	{
		return this.m_Parent;
	};

	ClipperLib.PolyNode.prototype.IsHole = function ()
	{
		return this.IsHoleNode();
	};

	// PolyTree : PolyNode
	/**
	 * @suppress {missingProperties}
	 * @constructor
	 */
	ClipperLib.PolyTree = function ()
	{
		this.m_AllPolys = [];
		ClipperLib.PolyNode.call(this);
	};

	ClipperLib.PolyTree.prototype.Clear = function ()
	{
		for (var i = 0, ilen = this.m_AllPolys.length; i < ilen; i++)
			this.m_AllPolys[i] = null;
		this.m_AllPolys.length = 0;
		this.m_Childs.length = 0;
	};

	ClipperLib.PolyTree.prototype.GetFirst = function ()
	{
		if (this.m_Childs.length > 0)
			return this.m_Childs[0];
		else
			return null;
	};

	ClipperLib.PolyTree.prototype.Total = function ()
	{
		var result = this.m_AllPolys.length;
		//with negative offsets, ignore the hidden outer polygon ...
		if (result > 0 && this.m_Childs[0] !== this.m_AllPolys[0]) result--;
		return result;
	};

	Inherit(ClipperLib.PolyTree, ClipperLib.PolyNode);

	// PolyTree & PolyNode end

	ClipperLib.Clear = function (a)
	{
		a.length = 0;
	};

	//ClipperLib.MaxSteps = 64; // How many steps at maximum in arc in BuildArc() function
	ClipperLib.PI = 3.141592653589793;
	ClipperLib.PI2 = 2 * 3.141592653589793;
	/**
	* @constructor
	*/
	ClipperLib.FPoint = function ()
	{
		var a = arguments,
			alen = a.length;
		this.X = 0;
		this.Y = 0;
		if (ClipperLib.use_xyz)
		{
			this.Z = 0;
			if (alen === 3) // public FPoint(cInt x, cInt y, cInt z = 0)
			{
				this.X = a[0];
				this.Y = a[1];
				this.Z = a[2];
			}
			else if (alen === 2) // public FPoint(cInt x, cInt y)
			{
				this.X = a[0];
				this.Y = a[1];
				this.Z = 0;
			}
			else if (alen === 1)
			{
				if (a[0] instanceof ClipperLib.FPoint) // public FPoint(FPoint dp)
				{
					var dp = a[0];
					this.X = dp.X;
					this.Y = dp.Y;
					this.Z = 0;
				}
				else // public FPoint(FPoint pt)
				{
					var pt = a[0];
					if (typeof (pt.Z) === "undefined") pt.Z = 0;
					this.X = pt.X;
					this.Y = pt.Y;
					this.Z = pt.Z;
				}
			}
			else // public FPoint()
			{
				this.X = 0;
				this.Y = 0;
				this.Z = 0;
			}
		}
		else // if (!ClipperLib.use_xyz)
		{
			if (alen === 2) // public FPoint(cInt X, cInt Y)
			{
				this.X = a[0];
				this.Y = a[1];
			}
			else if (alen === 1)
			{
				if (a[0] instanceof ClipperLib.FPoint) // public FPoint(FPoint dp)
				{
					var dp = a[0];
					this.X = dp.X;
					this.Y = dp.Y;
				}
				else // public FPoint(FPoint pt)
				{
					var pt = a[0];
					this.X = pt.X;
					this.Y = pt.Y;
				}
			}
			else // public FPoint(FPoint pt)
			{
				this.X = 0;
				this.Y = 0;
			}
		}
	};

	ClipperLib.FPoint.op_Equality = function (a, b)
	{
		//return a == b;
		return a.X === b.X && a.Y === b.Y;
	};

	ClipperLib.FPoint.op_Inequality = function (a, b)
	{
		//return a !== b;
		return a.X !== b.X || a.Y !== b.Y;
	};

	/*
  ClipperLib.FPoint.prototype.Equals = function (obj)
  {
    if (obj === null)
        return false;
    if (obj instanceof ClipperLib.FPoint)
    {
        var a = Cast(obj, ClipperLib.FPoint);
        return (this.X == a.X) && (this.Y == a.Y);
    }
    else
        return false;
  };

	*/

	/**
	* @constructor
	*/
	ClipperLib.FPoint0 = function ()
	{
		this.X = 0;
		this.Y = 0;
		if (ClipperLib.use_xyz)
			this.Z = 0;
	};

	ClipperLib.FPoint0.prototype = ClipperLib.FPoint.prototype;

	/**
	* @constructor
	*/
	ClipperLib.FPoint1 = function (pt)
	{
		this.X = pt.X;
		this.Y = pt.Y;
		if (ClipperLib.use_xyz)
		{
			if (typeof pt.Z === "undefined") this.Z = 0;
			else this.Z = pt.Z;
		}
	};

	ClipperLib.FPoint1.prototype = ClipperLib.FPoint.prototype;

	/**
	* @constructor
	*/
	ClipperLib.FPoint1dp = function (dp)
	{
		this.X = dp.X;
		this.Y = dp.Y;
		if (ClipperLib.use_xyz)
			this.Z = 0;
	};

	ClipperLib.FPoint1dp.prototype = ClipperLib.FPoint.prototype;

	/**
	* @constructor
	*/
	ClipperLib.FPoint2 = function (x, y, z)
	{
		this.X = x;
		this.Y = y;
		if (ClipperLib.use_xyz)
		{
			if (typeof z === "undefined") this.Z = 0;
			else this.Z = z;
		}
	};

	ClipperLib.FPoint2.prototype = ClipperLib.FPoint.prototype;

	/**
	* @constructor
	*/
	ClipperLib.FRect = function ()
	{
		var a = arguments,
			alen = a.length;
		if (alen === 4) // function (l, t, r, b)
		{
			this.left = a[0];
			this.top = a[1];
			this.right = a[2];
			this.bottom = a[3];
		}
		else if (alen === 1) // function (ir)
		{
			var ir = a[0];
			this.left = ir.left;
			this.top = ir.top;
			this.right = ir.right;
			this.bottom = ir.bottom;
		}
		else // function ()
		{
			this.left = 0;
			this.top = 0;
			this.right = 0;
			this.bottom = 0;
		}
	};

	/**
	* @constructor
	*/
	ClipperLib.FRect0 = function ()
	{
		this.left = 0;
		this.top = 0;
		this.right = 0;
		this.bottom = 0;
	};

	ClipperLib.FRect0.prototype = ClipperLib.FRect.prototype;

	/**
	* @constructor
	*/
	ClipperLib.FRect1 = function (ir)
	{
		this.left = ir.left;
		this.top = ir.top;
		this.right = ir.right;
		this.bottom = ir.bottom;
	};

	ClipperLib.FRect1.prototype = ClipperLib.FRect.prototype;

	/**
	* @constructor
	*/
	ClipperLib.FRect4 = function (l, t, r, b)
	{
		this.left = l;
		this.top = t;
		this.right = r;
		this.bottom = b;
	};

	ClipperLib.FRect4.prototype = ClipperLib.FRect.prototype;

	ClipperLib.ClipType = {
		ctIntersection: 0,
		ctUnion: 1,
		ctDifference: 2,
		ctXor: 3
	};

	ClipperLib.PolyType = {
		ptSubject: 0,
		ptClip: 1
	};

	ClipperLib.PolyFillType = {
		pftEvenOdd: 0,
		pftNonZero: 1,
		pftPositive: 2,
		pftNegative: 3
	};

	ClipperLib.JoinType = {
		jtSquare: 0,
		jtRound: 1,
		jtMiter: 2
	};

	ClipperLib.EndType = {
		etOpenSquare: 0,
		etOpenRound: 1,
		etOpenButt: 2,
		etClosedLine: 3,
		etClosedPolygon: 4
	};

	ClipperLib.EdgeSide = {
		esLeft: 0,
		esRight: 1
	};

	ClipperLib.Direction = {
		dRightToLeft: 0,
		dLeftToRight: 1
	};

	/**
	* @constructor
	*/
	ClipperLib.TEdge = function ()
	{
		this.Bot = new ClipperLib.FPoint0();
		this.Curr = new ClipperLib.FPoint0(); //current (updated for every new scanbeam)
		this.Top = new ClipperLib.FPoint0();
		this.Delta = new ClipperLib.FPoint0();
		this.Dx = 0;
		this.PolyTyp = ClipperLib.PolyType.ptSubject;
		this.Side = ClipperLib.EdgeSide.esLeft; //side only refers to current side of solution poly
		this.WindDelta = 0; //1 or -1 depending on winding direction
		this.WindCnt = 0;
		this.WindCnt2 = 0; //winding count of the opposite polytype
		this.OutIdx = 0;
		this.Next = null;
		this.Prev = null;
		this.NextInLML = null;
		this.NextInAEL = null;
		this.PrevInAEL = null;
		this.NextInSEL = null;
		this.PrevInSEL = null;
	};

	/**
	* @constructor
	*/
	ClipperLib.IntersectNode = function ()
	{
		this.Edge1 = null;
		this.Edge2 = null;
		this.Pt = new ClipperLib.FPoint0();
	};

	ClipperLib.MyIntersectNodeSort = function () {};

	ClipperLib.MyIntersectNodeSort.Compare = function (node1, node2)
	{
		var i = node2.Pt.Y - node1.Pt.Y;
		if (i > 0) return 1;
		else if (i < 0) return -1;
		else return 0;
	};

	/**
	* @constructor
	*/
	ClipperLib.LocalMinima = function ()
	{
		this.Y = 0;
		this.LeftBound = null;
		this.RightBound = null;
		this.Next = null;
	};

	/**
	* @constructor
	*/
	ClipperLib.Scanbeam = function ()
	{
		this.Y = 0;
		this.Next = null;
	};

	/**
	* @constructor
	*/
	ClipperLib.Maxima = function ()
	{
		this.X = 0;
		this.Next = null;
		this.Prev = null;
	};

	//OutRec: contains a path in the clipping solution. Edges in the AEL will
	//carry a pointer to an OutRec when they are part of the clipping solution.
	/**
	* @constructor
	*/
	ClipperLib.OutRec = function ()
	{
		this.Idx = 0;
		this.IsHole = false;
		this.IsOpen = false;
		this.FirstLeft = null; //see comments in clipper.pas
		this.Pts = null;
		this.BottomPt = null;
		this.PolyNode = null;
	};

	/**
	* @constructor
	*/
	ClipperLib.OutPt = function ()
	{
		this.Idx = 0;
		this.Pt = new ClipperLib.FPoint0();
		this.Next = null;
		this.Prev = null;
	};

	/**
	* @constructor
	*/
	ClipperLib.Join = function ()
	{
		this.OutPt1 = null;
		this.OutPt2 = null;
		this.OffPt = new ClipperLib.FPoint0();
	};

	ClipperLib.ClipperBase = function ()
	{
		this.m_MinimaList = null;
		this.m_CurrentLM = null;
		this.m_edges = new Array();
		this.m_HasOpenPaths = false;
		this.PreserveCollinear = false;
		this.m_Scanbeam = null;
		this.m_PolyOuts = null;
		this.m_ActiveEdges = null;
	};

	ClipperLib.ClipperBase.horizontal = -3.4E+38;
	ClipperLib.ClipperBase.Skip = -2;
	ClipperLib.ClipperBase.Unassigned = -1;
	ClipperLib.ClipperBase.tolerance = 1E-20;

	// The MAX_VALUE property has a value of 1.7976931348623157e+308. Values larger than MAX_VALUE are represented as "Infinity".
	//MIN_VALUE has a value of 5e-324. Values smaller than MIN_VALUE ("underflow values") are converted to 0.
	ClipperLib.ClipperBase.maxValue = Math.sqrt(Number.MAX_VALUE); // 1.3407807929942596e+154
	ClipperLib.ClipperBase.minValue = Math.sqrt(Number.MIN_VALUE); // 2.2227587494850775e-162

	ClipperLib.ClipperBase.near_zero = function (val)
	{
		return (val > -ClipperLib.ClipperBase.tolerance) && (val < ClipperLib.ClipperBase.tolerance);
	};

	ClipperLib.ClipperBase.IsHorizontal = function (e)
	{
		return e.Delta.Y === 0;
	};

	ClipperLib.ClipperBase.prototype.PointIsVertex = function (pt, pp)
	{
		var pp2 = pp;
		do {
			if (ClipperLib.FPoint.op_Equality(pp2.Pt, pt))
				return true;
			pp2 = pp2.Next;
		}
		while (pp2 !== pp)
		return false;
	};

	ClipperLib.ClipperBase.prototype.PointOnLineSegment = function (pt, linePt1, linePt2)
	{
			return ((pt.X === linePt1.X) && (pt.Y === linePt1.Y)) || ((pt.X === linePt2.X) && (pt.Y === linePt2.Y)) || (((pt.X > linePt1.X) === (pt.X < linePt2.X)) && ((pt.Y > linePt1.Y) === (pt.Y < linePt2.Y)) && ((pt.X - linePt1.X) * (linePt2.Y - linePt1.Y) === (linePt2.X - linePt1.X) * (pt.Y - linePt1.Y)));
	};

	ClipperLib.ClipperBase.prototype.PointOnPolygon = function (pt, pp)
	{
		var pp2 = pp;
		while (true)
		{
			if (this.PointOnLineSegment(pt, pp2.Pt, pp2.Next.Pt))
				return true;
			pp2 = pp2.Next;
			if (pp2 === pp)
				break;
		}
		return false;
	};

	ClipperLib.ClipperBase.prototype.SlopesEqual = ClipperLib.ClipperBase.SlopesEqual = function ()
	{
		var a = arguments,
			alen = a.length;
		var e1, e2, pt1, pt2, pt3, pt4;
		if (alen === 2) // function (e1, e2)
		{
			e1 = a[0];
			e2 = a[1];
			return e1.Delta.Y * e2.Delta.X === e1.Delta.X * e2.Delta.Y;
		}
		else if (alen === 3) // function (pt1, pt2, pt3)
		{
			pt1 = a[0];
			pt2 = a[1];
			pt3 = a[2];
			return (pt1.Y - pt2.Y) * (pt2.X - pt3.X) - (pt1.X - pt2.X) * (pt2.Y - pt3.Y) === 0;
		}
		else // function (pt1, pt2, pt3, pt4)
		{
			pt1 = a[0];
			pt2 = a[1];
			pt3 = a[2];
			pt4 = a[3];
			return (pt1.Y - pt2.Y) * (pt3.X - pt4.X) - (pt1.X - pt2.X) * (pt3.Y - pt4.Y) === 0;
		}
	};

	ClipperLib.ClipperBase.SlopesEqual3 = function (e1, e2)
	{
		return e1.Delta.Y * e2.Delta.X === e1.Delta.X * e2.Delta.Y;
	};

	ClipperLib.ClipperBase.SlopesEqual4 = function (pt1, pt2, pt3)
	{
		return (pt1.Y - pt2.Y) * (pt2.X - pt3.X) - (pt1.X - pt2.X) * (pt2.Y - pt3.Y) === 0;
	};

	ClipperLib.ClipperBase.SlopesEqual5 = function (pt1, pt2, pt3, pt4)
	{
		return (pt1.Y - pt2.Y) * (pt3.X - pt4.X) - (pt1.X - pt2.X) * (pt3.Y - pt4.Y) === 0;
	};

	ClipperLib.ClipperBase.prototype.Clear = function ()
	{
		this.DisposeLocalMinimaList();
		for (var i = 0, ilen = this.m_edges.length; i < ilen; ++i)
		{
			for (var j = 0, jlen = this.m_edges[i].length; j < jlen; ++j)
				this.m_edges[i][j] = null;
			ClipperLib.Clear(this.m_edges[i]);
		}
		ClipperLib.Clear(this.m_edges);
		this.m_HasOpenPaths = false;
	};

	ClipperLib.ClipperBase.prototype.DisposeLocalMinimaList = function ()
	{
		while (this.m_MinimaList !== null)
		{
			var tmpLm = this.m_MinimaList.Next;
			this.m_MinimaList = null;
			this.m_MinimaList = tmpLm;
		}
		this.m_CurrentLM = null;
	};

	ClipperLib.ClipperBase.prototype.RangeTest = function (pt)
	{
		if(pt.X > ClipperLib.ClipperBase.maxValue || pt.X < -ClipperLib.ClipperBase.maxValue
		|| pt.Y > ClipperLib.ClipperBase.maxValue || pt.Y < -ClipperLib.ClipperBase.maxValue
|| (pt.X > 0 && pt.X < ClipperLib.ClipperBase.minValue)
|| (pt.Y > 0 && pt.Y < ClipperLib.ClipperBase.minValue)
|| (pt.X < 0 && pt.X > -ClipperLib.ClipperBase.minValue)
|| (pt.Y < 0 && pt.Y > -ClipperLib.ClipperBase.minValue))
			ClipperLib.Error("Coordinate outside allowed range in RangeTest().");
	};

	ClipperLib.ClipperBase.prototype.InitEdge = function (e, eNext, ePrev, pt)
	{
		e.Next = eNext;
		e.Prev = ePrev;
		//e.Curr = pt;
		e.Curr.X = pt.X;
		e.Curr.Y = pt.Y;
		if (ClipperLib.use_xyz) e.Curr.Z = pt.Z;
		e.OutIdx = -1;
	};

	ClipperLib.ClipperBase.prototype.InitEdge2 = function (e, polyType)
	{
		if (e.Curr.Y >= e.Next.Curr.Y)
		{
			//e.Bot = e.Curr;
			e.Bot.X = e.Curr.X;
			e.Bot.Y = e.Curr.Y;
			if (ClipperLib.use_xyz) e.Bot.Z = e.Curr.Z;
			//e.Top = e.Next.Curr;
			e.Top.X = e.Next.Curr.X;
			e.Top.Y = e.Next.Curr.Y;
			if (ClipperLib.use_xyz) e.Top.Z = e.Next.Curr.Z;
		}
		else
		{
			//e.Top = e.Curr;
			e.Top.X = e.Curr.X;
			e.Top.Y = e.Curr.Y;
			if (ClipperLib.use_xyz) e.Top.Z = e.Curr.Z;
			//e.Bot = e.Next.Curr;
			e.Bot.X = e.Next.Curr.X;
			e.Bot.Y = e.Next.Curr.Y;
			if (ClipperLib.use_xyz) e.Bot.Z = e.Next.Curr.Z;
		}
		this.SetDx(e);
		e.PolyTyp = polyType;
	};

	ClipperLib.ClipperBase.prototype.FindNextLocMin = function (E)
	{
		var E2;
		for (;;)
		{
			while (ClipperLib.FPoint.op_Inequality(E.Bot, E.Prev.Bot) || ClipperLib.FPoint.op_Equality(E.Curr, E.Top))
				E = E.Next;
			if (E.Dx !== ClipperLib.ClipperBase.horizontal && E.Prev.Dx !== ClipperLib.ClipperBase.horizontal)
				break;
			while (E.Prev.Dx === ClipperLib.ClipperBase.horizontal)
				E = E.Prev;
			E2 = E;
			while (E.Dx === ClipperLib.ClipperBase.horizontal)
				E = E.Next;
			if (E.Top.Y === E.Prev.Bot.Y)
				continue;
			//ie just an intermediate horz.
			if (E2.Prev.Bot.X < E.Bot.X)
				E = E2;
			break;
		}
		return E;
	};

	ClipperLib.ClipperBase.prototype.ProcessBound = function (E, LeftBoundIsForward)
	{
		var EStart;
		var Result = E;
		var Horz;

		if (Result.OutIdx === ClipperLib.ClipperBase.Skip)
		{
			//check if there are edges beyond the skip edge in the bound and if so
			//create another LocMin and calling ProcessBound once more ...
			E = Result;
			if (LeftBoundIsForward)
			{
				while (E.Top.Y === E.Next.Bot.Y) E = E.Next;
				while (E !== Result && E.Dx === ClipperLib.ClipperBase.horizontal) E = E.Prev;
			}
			else
			{
				while (E.Top.Y === E.Prev.Bot.Y) E = E.Prev;
				while (E !== Result && E.Dx === ClipperLib.ClipperBase.horizontal) E = E.Next;
			}
			if (E === Result)
			{
				if (LeftBoundIsForward) Result = E.Next;
				else Result = E.Prev;
			}
			else
			{
				//there are more edges in the bound beyond result starting with E
				if (LeftBoundIsForward)
					E = Result.Next;
				else
					E = Result.Prev;
				var locMin = new ClipperLib.LocalMinima();
				locMin.Next = null;
				locMin.Y = E.Bot.Y;
				locMin.LeftBound = null;
				locMin.RightBound = E;
				E.WindDelta = 0;
				Result = this.ProcessBound(E, LeftBoundIsForward);
				this.InsertLocalMinima(locMin);
			}
			return Result;
		}

		if (E.Dx === ClipperLib.ClipperBase.horizontal)
		{
			//We need to be careful with open paths because this may not be a
			//true local minima (ie E may be following a skip edge).
			//Also, consecutive horz. edges may start heading left before going right.
			if (LeftBoundIsForward) EStart = E.Prev;
			else EStart = E.Next;

			if (EStart.Dx === ClipperLib.ClipperBase.horizontal) //ie an adjoining horizontal skip edge
			{
				if (EStart.Bot.X !== E.Bot.X && EStart.Top.X !== E.Bot.X)
					this.ReverseHorizontal(E);
			}
			else if (EStart.Bot.X !== E.Bot.X)
				this.ReverseHorizontal(E);
		}

		EStart = E;
		if (LeftBoundIsForward)
		{
			while (Result.Top.Y === Result.Next.Bot.Y && Result.Next.OutIdx !== ClipperLib.ClipperBase.Skip)
				Result = Result.Next;
			if (Result.Dx === ClipperLib.ClipperBase.horizontal && Result.Next.OutIdx !== ClipperLib.ClipperBase.Skip)
			{
				//nb: at the top of a bound, horizontals are added to the bound
				//only when the preceding edge attaches to the horizontal's left vertex
				//unless a Skip edge is encountered when that becomes the top divide
				Horz = Result;
				while (Horz.Prev.Dx === ClipperLib.ClipperBase.horizontal)
					Horz = Horz.Prev;
				if (Horz.Prev.Top.X > Result.Next.Top.X)
					Result = Horz.Prev;
			}
			while (E !== Result)
			{
				E.NextInLML = E.Next;
				if (E.Dx === ClipperLib.ClipperBase.horizontal && E !== EStart && E.Bot.X !== E.Prev.Top.X)
					this.ReverseHorizontal(E);
				E = E.Next;
			}
			if (E.Dx === ClipperLib.ClipperBase.horizontal && E !== EStart && E.Bot.X !== E.Prev.Top.X)
				this.ReverseHorizontal(E);
			Result = Result.Next;
			//move to the edge just beyond current bound
		}
		else
		{
			while (Result.Top.Y === Result.Prev.Bot.Y && Result.Prev.OutIdx !== ClipperLib.ClipperBase.Skip)
				Result = Result.Prev;
			if (Result.Dx === ClipperLib.ClipperBase.horizontal && Result.Prev.OutIdx !== ClipperLib.ClipperBase.Skip)
			{
				Horz = Result;
				while (Horz.Next.Dx === ClipperLib.ClipperBase.horizontal)
					Horz = Horz.Next;
				if (Horz.Next.Top.X === Result.Prev.Top.X || Horz.Next.Top.X > Result.Prev.Top.X)
				{
					Result = Horz.Next;
				}
			}
			while (E !== Result)
			{
				E.NextInLML = E.Prev;
				if (E.Dx === ClipperLib.ClipperBase.horizontal && E !== EStart && E.Bot.X !== E.Next.Top.X)
					this.ReverseHorizontal(E);
				E = E.Prev;
			}
			if (E.Dx === ClipperLib.ClipperBase.horizontal && E !== EStart && E.Bot.X !== E.Next.Top.X)
				this.ReverseHorizontal(E);
			Result = Result.Prev;
			//move to the edge just beyond current bound
		}

		return Result;
	};

	ClipperLib.ClipperBase.prototype.AddPath = function (pg, polyType, Closed)
	{
		if (ClipperLib.use_lines)
		{
			if (!Closed && polyType === ClipperLib.PolyType.ptClip)
				ClipperLib.Error("AddPath: Open paths must be subject.");
		}
		else
		{
			if (!Closed)
				ClipperLib.Error("AddPath: Open paths have been disabled.");
		}
		var highI = pg.length - 1;
		if (Closed)
			while (highI > 0 && (ClipperLib.FPoint.op_Equality(pg[highI], pg[0])))
				--highI;
		while (highI > 0 && (ClipperLib.FPoint.op_Equality(pg[highI], pg[highI - 1])))
			--highI;
		if ((Closed && highI < 2) || (!Closed && highI < 1))
			return false;
		//create a new edge array ...
		var edges = new Array();
		for (var i = 0; i <= highI; i++)
			edges.push(new ClipperLib.TEdge());
		var IsFlat = true;
		//1. Basic (first) edge initialization ...

		//edges[1].Curr = pg[1];
		edges[1].Curr.X = pg[1].X;
		edges[1].Curr.Y = pg[1].Y;
		if (ClipperLib.use_xyz) edges[1].Curr.Z = pg[1].Z;

		this.RangeTest(pg[0]);

		this.RangeTest(pg[highI]);

		this.InitEdge(edges[0], edges[1], edges[highI], pg[0]);
		this.InitEdge(edges[highI], edges[0], edges[highI - 1], pg[highI]);
		for (var i = highI - 1; i >= 1; --i)
		{
			this.RangeTest(pg[i]);

			this.InitEdge(edges[i], edges[i + 1], edges[i - 1], pg[i]);
		}

		var eStart = edges[0];
		//2. Remove duplicate vertices, and (when closed) collinear edges ...
		var E = eStart,
			eLoopStop = eStart;
		for (;;)
		{
			//console.log(E.Next, eStart);
			//nb: allows matching start and end points when not Closed ...
			if (E.Curr === E.Next.Curr && (Closed || E.Next !== eStart))
			{
				if (E === E.Next)
					break;
				if (E === eStart)
					eStart = E.Next;
				E = this.RemoveEdge(E);
				eLoopStop = E;
				continue;
			}
			if (E.Prev === E.Next)
				break;
			else if (Closed && ClipperLib.ClipperBase.SlopesEqual4(E.Prev.Curr, E.Curr, E.Next.Curr) && (!this.PreserveCollinear || !this.Pt2IsBetweenPt1AndPt3(E.Prev.Curr, E.Curr, E.Next.Curr)))
			{
				//Collinear edges are allowed for open paths but in closed paths
				//the default is to merge adjacent collinear edges into a single edge.
				//However, if the PreserveCollinear property is enabled, only overlapping
				//collinear edges (ie spikes) will be removed from closed paths.
				if (E === eStart)
					eStart = E.Next;
				E = this.RemoveEdge(E);
				E = E.Prev;
				eLoopStop = E;
				continue;
			}
			E = E.Next;
			if ((E === eLoopStop) || (!Closed && E.Next === eStart)) break;
		}
		if ((!Closed && (E === E.Next)) || (Closed && (E.Prev === E.Next)))
			return false;
		if (!Closed)
		{
			this.m_HasOpenPaths = true;
			eStart.Prev.OutIdx = ClipperLib.ClipperBase.Skip;
		}
		//3. Do second stage of edge initialization ...
		E = eStart;
		do {
			this.InitEdge2(E, polyType);
			E = E.Next;
			if (IsFlat && E.Curr.Y !== eStart.Curr.Y)
				IsFlat = false;
		}
		while (E !== eStart)
		//4. Finally, add edge bounds to LocalMinima list ...
		//Totally flat paths must be handled differently when adding them
		//to LocalMinima list to avoid endless loops etc ...
		if (IsFlat)
		{
			if (Closed)
				return false;

			E.Prev.OutIdx = ClipperLib.ClipperBase.Skip;

			var locMin = new ClipperLib.LocalMinima();
			locMin.Next = null;
			locMin.Y = E.Bot.Y;
			locMin.LeftBound = null;
			locMin.RightBound = E;
			locMin.RightBound.Side = ClipperLib.EdgeSide.esRight;
			locMin.RightBound.WindDelta = 0;

			for (;;)
			{
				if (E.Bot.X !== E.Prev.Top.X) this.ReverseHorizontal(E);
				if (E.Next.OutIdx === ClipperLib.ClipperBase.Skip) break;
				E.NextInLML = E.Next;
				E = E.Next;
			}
			this.InsertLocalMinima(locMin);
			this.m_edges.push(edges);
			return true;
		}
		this.m_edges.push(edges);
		var leftBoundIsForward;
		var EMin = null;

		//workaround to avoid an endless loop in the while loop below when
		//open paths have matching start and end points ...
		if (ClipperLib.FPoint.op_Equality(E.Prev.Bot, E.Prev.Top))
			E = E.Next;

		for (;;)
		{
			E = this.FindNextLocMin(E);
			if (E === EMin)
				break;
			else if (EMin === null)
				EMin = E;
			//E and E.Prev now share a local minima (left aligned if horizontal).
			//Compare their slopes to find which starts which bound ...
			var locMin = new ClipperLib.LocalMinima();
			locMin.Next = null;
			locMin.Y = E.Bot.Y;
			if (E.Dx < E.Prev.Dx)
			{
				locMin.LeftBound = E.Prev;
				locMin.RightBound = E;
				leftBoundIsForward = false;
				//Q.nextInLML = Q.prev
			}
			else
			{
				locMin.LeftBound = E;
				locMin.RightBound = E.Prev;
				leftBoundIsForward = true;
				//Q.nextInLML = Q.next
			}
			locMin.LeftBound.Side = ClipperLib.EdgeSide.esLeft;
			locMin.RightBound.Side = ClipperLib.EdgeSide.esRight;
			if (!Closed)
				locMin.LeftBound.WindDelta = 0;
			else if (locMin.LeftBound.Next === locMin.RightBound)
				locMin.LeftBound.WindDelta = -1;
			else
				locMin.LeftBound.WindDelta = 1;
			locMin.RightBound.WindDelta = -locMin.LeftBound.WindDelta;
			E = this.ProcessBound(locMin.LeftBound, leftBoundIsForward);
			if (E.OutIdx === ClipperLib.ClipperBase.Skip)
				E = this.ProcessBound(E, leftBoundIsForward);
			var E2 = this.ProcessBound(locMin.RightBound, !leftBoundIsForward);
			if (E2.OutIdx === ClipperLib.ClipperBase.Skip) E2 = this.ProcessBound(E2, !leftBoundIsForward);
			if (locMin.LeftBound.OutIdx === ClipperLib.ClipperBase.Skip)
				locMin.LeftBound = null;
			else if (locMin.RightBound.OutIdx === ClipperLib.ClipperBase.Skip)
				locMin.RightBound = null;
			this.InsertLocalMinima(locMin);
			if (!leftBoundIsForward)
				E = E2;
		}
		return true;
	};

	ClipperLib.ClipperBase.prototype.AddPaths = function (ppg, polyType, closed)
	{
		//  console.log("-------------------------------------------");
		//  console.log(JSON.stringify(ppg));
		var result = false;
		for (var i = 0, ilen = ppg.length; i < ilen; ++i)
			if (this.AddPath(ppg[i], polyType, closed))
				result = true;
		return result;
	};

	ClipperLib.ClipperBase.prototype.Pt2IsBetweenPt1AndPt3 = function (pt1, pt2, pt3)
	{
		if ((ClipperLib.FPoint.op_Equality(pt1, pt3)) || (ClipperLib.FPoint.op_Equality(pt1, pt2)) || (ClipperLib.FPoint.op_Equality(pt3, pt2)))

			//if ((pt1 == pt3) || (pt1 == pt2) || (pt3 == pt2))
			return false;

		else if (pt1.X !== pt3.X)
			return (pt2.X > pt1.X) === (pt2.X < pt3.X);
		else
			return (pt2.Y > pt1.Y) === (pt2.Y < pt3.Y);
	};

	ClipperLib.ClipperBase.prototype.RemoveEdge = function (e)
	{
		//removes e from double_linked_list (but without removing from memory)
		e.Prev.Next = e.Next;
		e.Next.Prev = e.Prev;
		var result = e.Next;
		e.Prev = null; //flag as removed (see ClipperBase.Clear)
		return result;
	};

	ClipperLib.ClipperBase.prototype.SetDx = function (e)
	{
		e.Delta.X = (e.Top.X - e.Bot.X);
		e.Delta.Y = (e.Top.Y - e.Bot.Y);
		if (e.Delta.Y === 0) e.Dx = ClipperLib.ClipperBase.horizontal;
		else e.Dx = (e.Delta.X) / (e.Delta.Y);
	};

	ClipperLib.ClipperBase.prototype.InsertLocalMinima = function (newLm)
	{
		if (this.m_MinimaList === null)
		{
			this.m_MinimaList = newLm;
		}
		else if (newLm.Y >= this.m_MinimaList.Y)
		{
			newLm.Next = this.m_MinimaList;
			this.m_MinimaList = newLm;
		}
		else
		{
			var tmpLm = this.m_MinimaList;
			while (tmpLm.Next !== null && (newLm.Y < tmpLm.Next.Y))
				tmpLm = tmpLm.Next;
			newLm.Next = tmpLm.Next;
			tmpLm.Next = newLm;
		}
	};

	ClipperLib.ClipperBase.prototype.PopLocalMinima = function (Y, current)
	{
		current.v = this.m_CurrentLM;
		if (this.m_CurrentLM !== null && this.m_CurrentLM.Y === Y)
		{
			this.m_CurrentLM = this.m_CurrentLM.Next;
			return true;
		}
		return false;
	};

	ClipperLib.ClipperBase.prototype.ReverseHorizontal = function (e)
	{
		//swap horizontal edges' top and bottom x's so they follow the natural
		//progression of the bounds - ie so their xbots will align with the
		//adjoining lower edge. [Helpful in the ProcessHorizontal() method.]
		var tmp = e.Top.X;
		e.Top.X = e.Bot.X;
		e.Bot.X = tmp;
		if (ClipperLib.use_xyz)
		{
			tmp = e.Top.Z;
			e.Top.Z = e.Bot.Z;
			e.Bot.Z = tmp;
		}
	};

	ClipperLib.ClipperBase.prototype.Reset = function ()
	{
		this.m_CurrentLM = this.m_MinimaList;
		if (this.m_CurrentLM === null) //ie nothing to process
			return;
		//reset all edges ...
		this.m_Scanbeam = null;
		var lm = this.m_MinimaList;
		while (lm !== null)
		{
			this.InsertScanbeam(lm.Y);
			var e = lm.LeftBound;
			if (e !== null)
			{
				//e.Curr = e.Bot;
				e.Curr.X = e.Bot.X;
				e.Curr.Y = e.Bot.Y;
				if (ClipperLib.use_xyz) e.Curr.Z = e.Bot.Z;
				e.OutIdx = ClipperLib.ClipperBase.Unassigned;
			}
			e = lm.RightBound;
			if (e !== null)
			{
				//e.Curr = e.Bot;
				e.Curr.X = e.Bot.X;
				e.Curr.Y = e.Bot.Y;
				if (ClipperLib.use_xyz) e.Curr.Z = e.Bot.Z;
				e.OutIdx = ClipperLib.ClipperBase.Unassigned;
			}
			lm = lm.Next;
		}
		this.m_ActiveEdges = null;
	};

	ClipperLib.ClipperBase.prototype.InsertScanbeam = function (Y)
	{
		//single-linked list: sorted descending, ignoring dups.
		if (this.m_Scanbeam === null)
		{
			this.m_Scanbeam = new ClipperLib.Scanbeam();
			this.m_Scanbeam.Next = null;
			this.m_Scanbeam.Y = Y;
		}
		else if (Y > this.m_Scanbeam.Y)
		{
			var newSb = new ClipperLib.Scanbeam();
			newSb.Y = Y;
			newSb.Next = this.m_Scanbeam;
			this.m_Scanbeam = newSb;
		}
		else
		{
			var sb2 = this.m_Scanbeam;
			while (sb2.Next !== null && Y <= sb2.Next.Y)
			{
				sb2 = sb2.Next;
			}
			if (Y === sb2.Y)
			{
				return;
			} //ie ignores duplicates
			var newSb1 = new ClipperLib.Scanbeam();
			newSb1.Y = Y;
			newSb1.Next = sb2.Next;
			sb2.Next = newSb1;
		}
	};

	ClipperLib.ClipperBase.prototype.PopScanbeam = function (Y)
	{
		if (this.m_Scanbeam === null)
		{
			Y.v = 0;
			return false;
		}
		Y.v = this.m_Scanbeam.Y;
		this.m_Scanbeam = this.m_Scanbeam.Next;
		return true;
	};

	ClipperLib.ClipperBase.prototype.LocalMinimaPending = function ()
	{
		return (this.m_CurrentLM !== null);
	};

	ClipperLib.ClipperBase.prototype.CreateOutRec = function ()
	{
		var result = new ClipperLib.OutRec();
		result.Idx = ClipperLib.ClipperBase.Unassigned;
		result.IsHole = false;
		result.IsOpen = false;
		result.FirstLeft = null;
		result.Pts = null;
		result.BottomPt = null;
		result.PolyNode = null;
		this.m_PolyOuts.push(result);
		result.Idx = this.m_PolyOuts.length - 1;
		return result;
	};

	ClipperLib.ClipperBase.prototype.DisposeOutRec = function (index)
	{
		var outRec = this.m_PolyOuts[index];
		outRec.Pts = null;
		outRec = null;
		this.m_PolyOuts[index] = null;
	};

	ClipperLib.ClipperBase.prototype.UpdateEdgeIntoAEL = function (e)
	{
		if (e.NextInLML === null)
		{
			ClipperLib.Error("UpdateEdgeIntoAEL: invalid call");
		}
		var AelPrev = e.PrevInAEL;
		var AelNext = e.NextInAEL;
		e.NextInLML.OutIdx = e.OutIdx;
		if (AelPrev !== null)
		{
			AelPrev.NextInAEL = e.NextInLML;
		}
		else
		{
			this.m_ActiveEdges = e.NextInLML;
		}
		if (AelNext !== null)
		{
			AelNext.PrevInAEL = e.NextInLML;
		}
		e.NextInLML.Side = e.Side;
		e.NextInLML.WindDelta = e.WindDelta;
		e.NextInLML.WindCnt = e.WindCnt;
		e.NextInLML.WindCnt2 = e.WindCnt2;
		e = e.NextInLML;
		e.Curr.X = e.Bot.X;
		e.Curr.Y = e.Bot.Y;
		e.PrevInAEL = AelPrev;
		e.NextInAEL = AelNext;
		if (!ClipperLib.ClipperBase.IsHorizontal(e))
		{
			this.InsertScanbeam(e.Top.Y);
		}
		return e;
	};

	ClipperLib.ClipperBase.prototype.SwapPositionsInAEL = function (edge1, edge2)
	{
		//check that one or other edge hasn't already been removed from AEL ...
		if (edge1.NextInAEL === edge1.PrevInAEL || edge2.NextInAEL === edge2.PrevInAEL)
		{
			return;
		}

		if (edge1.NextInAEL === edge2)
		{
			var next = edge2.NextInAEL;
			if (next !== null)
			{
				next.PrevInAEL = edge1;
			}
			var prev = edge1.PrevInAEL;
			if (prev !== null)
			{
				prev.NextInAEL = edge2;
			}
			edge2.PrevInAEL = prev;
			edge2.NextInAEL = edge1;
			edge1.PrevInAEL = edge2;
			edge1.NextInAEL = next;
		}
		else if (edge2.NextInAEL === edge1)
		{
			var next1 = edge1.NextInAEL;
			if (next1 !== null)
			{
				next1.PrevInAEL = edge2;
			}
			var prev1 = edge2.PrevInAEL;
			if (prev1 !== null)
			{
				prev1.NextInAEL = edge1;
			}
			edge1.PrevInAEL = prev1;
			edge1.NextInAEL = edge2;
			edge2.PrevInAEL = edge1;
			edge2.NextInAEL = next1;
		}
		else
		{
			var next2 = edge1.NextInAEL;
			var prev2 = edge1.PrevInAEL;
			edge1.NextInAEL = edge2.NextInAEL;
			if (edge1.NextInAEL !== null)
			{
				edge1.NextInAEL.PrevInAEL = edge1;
			}
			edge1.PrevInAEL = edge2.PrevInAEL;
			if (edge1.PrevInAEL !== null)
			{
				edge1.PrevInAEL.NextInAEL = edge1;
			}
			edge2.NextInAEL = next2;
			if (edge2.NextInAEL !== null)
			{
				edge2.NextInAEL.PrevInAEL = edge2;
			}
			edge2.PrevInAEL = prev2;
			if (edge2.PrevInAEL !== null)
			{
				edge2.PrevInAEL.NextInAEL = edge2;
			}
		}

		if (edge1.PrevInAEL === null)
		{
			this.m_ActiveEdges = edge1;
		}
		else
		{
			if (edge2.PrevInAEL === null)
			{
				this.m_ActiveEdges = edge2;
			}
		}
	};

	ClipperLib.ClipperBase.prototype.DeleteFromAEL = function (e)
	{
		var AelPrev = e.PrevInAEL;
		var AelNext = e.NextInAEL;
		if (AelPrev === null && AelNext === null && e !== this.m_ActiveEdges)
		{
			return;
		} //already deleted
		if (AelPrev !== null)
		{
			AelPrev.NextInAEL = AelNext;
		}
		else
		{
			this.m_ActiveEdges = AelNext;
		}
		if (AelNext !== null)
		{
			AelNext.PrevInAEL = AelPrev;
		}
		e.NextInAEL = null;
		e.PrevInAEL = null;
	}

	// public Clipper(int InitOptions = 0)
	/**
	 * @suppress {missingProperties}
	 */
	ClipperLib.Clipper = function (InitOptions)
	{
		if (typeof (InitOptions) === "undefined") InitOptions = 0;
		this.m_PolyOuts = null;
		this.m_ClipType = ClipperLib.ClipType.ctIntersection;
		this.m_Scanbeam = null;
		this.m_Maxima = null;
		this.m_ActiveEdges = null;
		this.m_SortedEdges = null;
		this.m_IntersectList = null;
		this.m_IntersectNodeComparer = null;
		this.m_ExecuteLocked = false;
		this.m_ClipFillType = ClipperLib.PolyFillType.pftEvenOdd;
		this.m_SubjFillType = ClipperLib.PolyFillType.pftEvenOdd;
		this.m_Joins = null;
		this.m_GhostJoins = null;
		this.m_UsingPolyTree = false;
		this.ReverseSolution = false;
		this.StrictlySimple = false;

		ClipperLib.ClipperBase.call(this);

		this.m_Scanbeam = null;
		this.m_Maxima = null;
		this.m_ActiveEdges = null;
		this.m_SortedEdges = null;
		this.m_IntersectList = new Array();
		this.m_IntersectNodeComparer = ClipperLib.MyIntersectNodeSort.Compare;
		this.m_ExecuteLocked = false;
		this.m_UsingPolyTree = false;
		this.m_PolyOuts = new Array();
		this.m_Joins = new Array();
		this.m_GhostJoins = new Array();
		this.ReverseSolution = (1 & InitOptions) !== 0;
		this.StrictlySimple = (2 & InitOptions) !== 0;
		this.PreserveCollinear = (4 & InitOptions) !== 0;
		if (ClipperLib.use_xyz)
		{
			this.ZFillFunction = null; // function (FPoint bot1, FPoint top1, FPoint bot2, FPoint top2, ref FPoint intersectPt);
		}
	};

	ClipperLib.Clipper.ioReverseSolution = 1;
	ClipperLib.Clipper.ioStrictlySimple = 2;
	ClipperLib.Clipper.ioPreserveCollinear = 4;

	ClipperLib.Clipper.prototype.Clear = function ()
	{
		if (this.m_edges.length === 0)
			return;
		//avoids problems with ClipperBase destructor
		this.DisposeAllPolyPts();
		ClipperLib.ClipperBase.prototype.Clear.call(this);
	};

	ClipperLib.Clipper.prototype.InsertMaxima = function (X)
	{
		//double-linked list: sorted ascending, ignoring dups.
		var newMax = new ClipperLib.Maxima();
		newMax.X = X;
		if (this.m_Maxima === null)
		{
			this.m_Maxima = newMax;
			this.m_Maxima.Next = null;
			this.m_Maxima.Prev = null;
		}
		else if (X < this.m_Maxima.X)
		{
			newMax.Next = this.m_Maxima;
			newMax.Prev = null;
			this.m_Maxima = newMax;
		}
		else
		{
			var m = this.m_Maxima;
			while (m.Next !== null && X >= m.Next.X)
			{
				m = m.Next;
			}
			if (X === m.X)
			{
				return;
			} //ie ignores duplicates (& CG to clean up newMax)
			//insert newMax between m and m.Next ...
			newMax.Next = m.Next;
			newMax.Prev = m;
			if (m.Next !== null)
			{
				m.Next.Prev = newMax;
			}
			m.Next = newMax;
		}
	};

	// ************************************
	ClipperLib.Clipper.prototype.Execute = function ()
	{
		var a = arguments,
			alen = a.length,
			ispolytree = a[1] instanceof ClipperLib.PolyTree;
		if (alen === 4 && !ispolytree) // function (clipType, solution, subjFillType, clipFillType)
		{
			var clipType = a[0],
				solution = a[1],
				subjFillType = a[2],
				clipFillType = a[3];
			if (this.m_ExecuteLocked)
				return false;
			if (this.m_HasOpenPaths)
				ClipperLib.Error("Error: PolyTree struct is needed for open path clipping.");
			this.m_ExecuteLocked = true;
			ClipperLib.Clear(solution);
			this.m_SubjFillType = subjFillType;
			this.m_ClipFillType = clipFillType;
			this.m_ClipType = clipType;
			this.m_UsingPolyTree = false;
			try
			{
				var succeeded = this.ExecuteInternal();
				//build the return polygons ...
				if (succeeded) this.BuildResult(solution);
			}
			finally
			{
				this.DisposeAllPolyPts();
				this.m_ExecuteLocked = false;
			}
			return succeeded;
		}
		else if (alen === 4 && ispolytree) // function (clipType, polytree, subjFillType, clipFillType)
		{
			var clipType = a[0],
				polytree = a[1],
				subjFillType = a[2],
				clipFillType = a[3];
			if (this.m_ExecuteLocked)
				return false;
			this.m_ExecuteLocked = true;
			this.m_SubjFillType = subjFillType;
			this.m_ClipFillType = clipFillType;
			this.m_ClipType = clipType;
			this.m_UsingPolyTree = true;
			try
			{
				var succeeded = this.ExecuteInternal();
				//build the return polygons ...
				if (succeeded) this.BuildResult2(polytree);
			}
			finally
			{
				this.DisposeAllPolyPts();
				this.m_ExecuteLocked = false;
			}
			return succeeded;
		}
		else if (alen === 2 && !ispolytree) // function (clipType, solution)
		{
			var clipType = a[0],
				solution = a[1];
			return this.Execute(clipType, solution, ClipperLib.PolyFillType.pftEvenOdd, ClipperLib.PolyFillType.pftEvenOdd);
		}
		else if (alen === 2 && ispolytree) // function (clipType, polytree)
		{
			var clipType = a[0],
				polytree = a[1];
			return this.Execute(clipType, polytree, ClipperLib.PolyFillType.pftEvenOdd, ClipperLib.PolyFillType.pftEvenOdd);
		}
	};

	ClipperLib.Clipper.prototype.FixHoleLinkage = function (outRec)
	{
		//skip if an outermost polygon or
		//already already points to the correct FirstLeft ...
		if (outRec.FirstLeft === null || (outRec.IsHole !== outRec.FirstLeft.IsHole && outRec.FirstLeft.Pts !== null))
			return;
		var orfl = outRec.FirstLeft;
		while (orfl !== null && ((orfl.IsHole === outRec.IsHole) || orfl.Pts === null))
			orfl = orfl.FirstLeft;
		outRec.FirstLeft = orfl;
	};

	ClipperLib.Clipper.prototype.ExecuteInternal = function ()
	{
		try
		{
			this.Reset();
			this.m_SortedEdges = null;
			this.m_Maxima = null;

			var botY = {},
				topY = {};

			if (!this.PopScanbeam(botY))
			{
				return false;
			}
			this.InsertLocalMinimaIntoAEL(botY.v);
			while (this.PopScanbeam(topY) || this.LocalMinimaPending())
			{
				this.ProcessHorizontals();
				this.m_GhostJoins.length = 0;
				if (!this.ProcessIntersections(topY.v))
				{
					return false;
				}
				this.ProcessEdgesAtTopOfScanbeam(topY.v);
				botY.v = topY.v;
				this.InsertLocalMinimaIntoAEL(botY.v);
			}

			//fix orientations ...
			var outRec, i, ilen;
			//fix orientations ...
			for (i = 0, ilen = this.m_PolyOuts.length; i < ilen; i++)
			{
				outRec = this.m_PolyOuts[i];
				if (outRec.Pts === null || outRec.IsOpen) continue;
				if ((outRec.IsHole ^ this.ReverseSolution) == (this.Area$1(outRec) > 0))
					this.ReversePolyPtLinks(outRec.Pts);
			}

			this.JoinCommonEdges();

			for (i = 0, ilen = this.m_PolyOuts.length; i < ilen; i++)
			{
				outRec = this.m_PolyOuts[i];
				if (outRec.Pts === null)
					continue;
				else if (outRec.IsOpen)
					this.FixupOutPolyline(outRec);
				else
					this.FixupOutPolygon(outRec);
			}

			if (this.StrictlySimple) this.DoSimplePolygons();
			return true;
		}
		//catch { return false; }
		finally
		{
			this.m_Joins.length = 0;
			this.m_GhostJoins.length = 0;
		}
	};

	ClipperLib.Clipper.prototype.DisposeAllPolyPts = function ()
	{
		for (var i = 0, ilen = this.m_PolyOuts.length; i < ilen; ++i)
			this.DisposeOutRec(i);
		ClipperLib.Clear(this.m_PolyOuts);
	};

	ClipperLib.Clipper.prototype.AddJoin = function (Op1, Op2, OffPt)
	{
		var j = new ClipperLib.Join();
		j.OutPt1 = Op1;
		j.OutPt2 = Op2;
		//j.OffPt = OffPt;
		j.OffPt.X = OffPt.X;
		j.OffPt.Y = OffPt.Y;
		if (ClipperLib.use_xyz) j.OffPt.Z = OffPt.Z;
		this.m_Joins.push(j);
	};

	ClipperLib.Clipper.prototype.AddGhostJoin = function (Op, OffPt)
	{
		var j = new ClipperLib.Join();
		j.OutPt1 = Op;
		//j.OffPt = OffPt;
		j.OffPt.X = OffPt.X;
		j.OffPt.Y = OffPt.Y;
		if (ClipperLib.use_xyz) j.OffPt.Z = OffPt.Z;
		this.m_GhostJoins.push(j);
	};

	//if (ClipperLib.use_xyz)
	//{
	ClipperLib.Clipper.prototype.SetZ = function (pt, e1, e2)
	{
		if (this.ZFillFunction !== null)
		{
			if (pt.Z !== 0 || this.ZFillFunction === null) return;
			else if (ClipperLib.FPoint.op_Equality(pt, e1.Bot)) pt.Z = e1.Bot.Z;
			else if (ClipperLib.FPoint.op_Equality(pt, e1.Top)) pt.Z = e1.Top.Z;
			else if (ClipperLib.FPoint.op_Equality(pt, e2.Bot)) pt.Z = e2.Bot.Z;
			else if (ClipperLib.FPoint.op_Equality(pt, e2.Top)) pt.Z = e2.Top.Z;
			else this.ZFillFunction(e1.Bot, e1.Top, e2.Bot, e2.Top, pt);
		}
	};
	//}

	ClipperLib.Clipper.prototype.InsertLocalMinimaIntoAEL = function (botY)
	{
		var lm = {};

		var lb;
		var rb;
		while (this.PopLocalMinima(botY, lm))
		{
			lb = lm.v.LeftBound;
			rb = lm.v.RightBound;

			var Op1 = null;
			if (lb === null)
			{
				this.InsertEdgeIntoAEL(rb, null);
				this.SetWindingCount(rb);
				if (this.IsContributing(rb))
					Op1 = this.AddOutPt(rb, rb.Bot);
			}
			else if (rb === null)
			{
				this.InsertEdgeIntoAEL(lb, null);
				this.SetWindingCount(lb);
				if (this.IsContributing(lb))
					Op1 = this.AddOutPt(lb, lb.Bot);
				this.InsertScanbeam(lb.Top.Y);
			}
			else
			{
				this.InsertEdgeIntoAEL(lb, null);
				this.InsertEdgeIntoAEL(rb, lb);
				this.SetWindingCount(lb);
				rb.WindCnt = lb.WindCnt;
				rb.WindCnt2 = lb.WindCnt2;
				if (this.IsContributing(lb))
					Op1 = this.AddLocalMinPoly(lb, rb, lb.Bot);
				this.InsertScanbeam(lb.Top.Y);
			}
			if (rb !== null)
			{
				if (ClipperLib.ClipperBase.IsHorizontal(rb))
				{
					if (rb.NextInLML !== null)
					{
						this.InsertScanbeam(rb.NextInLML.Top.Y);
					}
					this.AddEdgeToSEL(rb);
				}
				else
				{
					this.InsertScanbeam(rb.Top.Y);
				}
			}
			if (lb === null || rb === null) continue;
			//if output polygons share an Edge with a horizontal rb, they'll need joining later ...
			if (Op1 !== null && ClipperLib.ClipperBase.IsHorizontal(rb) && this.m_GhostJoins.length > 0 && rb.WindDelta !== 0)
			{
				for (var i = 0, ilen = this.m_GhostJoins.length; i < ilen; i++)
				{
					//if the horizontal Rb and a 'ghost' horizontal overlap, then convert
					//the 'ghost' join to a real join ready for later ...
					var j = this.m_GhostJoins[i];

					if (this.HorzSegmentsOverlap(j.OutPt1.Pt.X, j.OffPt.X, rb.Bot.X, rb.Top.X))
						this.AddJoin(j.OutPt1, Op1, j.OffPt);
				}
			}

			if (lb.OutIdx >= 0 && lb.PrevInAEL !== null &&
				lb.PrevInAEL.Curr.X === lb.Bot.X &&
				lb.PrevInAEL.OutIdx >= 0 &&
				ClipperLib.ClipperBase.SlopesEqual5(lb.PrevInAEL.Curr, lb.PrevInAEL.Top, lb.Curr, lb.Top) &&
				lb.WindDelta !== 0 && lb.PrevInAEL.WindDelta !== 0)
			{
				var Op2 = this.AddOutPt(lb.PrevInAEL, lb.Bot);
				this.AddJoin(Op1, Op2, lb.Top);
			}
			if (lb.NextInAEL !== rb)
			{
				if (rb.OutIdx >= 0 && rb.PrevInAEL.OutIdx >= 0 &&
					ClipperLib.ClipperBase.SlopesEqual5(rb.PrevInAEL.Curr, rb.PrevInAEL.Top, rb.Curr, rb.Top) &&
					rb.WindDelta !== 0 && rb.PrevInAEL.WindDelta !== 0)
				{
					var Op2 = this.AddOutPt(rb.PrevInAEL, rb.Bot);
					this.AddJoin(Op1, Op2, rb.Top);
				}
				var e = lb.NextInAEL;
				if (e !== null)
					while (e !== rb)
					{
						//nb: For calculating winding counts etc, IntersectEdges() assumes
						//that param1 will be to the right of param2 ABOVE the intersection ...
						this.IntersectEdges(rb, e, lb.Curr);
						//order important here
						e = e.NextInAEL;
					}
			}
		}
	};

	ClipperLib.Clipper.prototype.InsertEdgeIntoAEL = function (edge, startEdge)
	{
		if (this.m_ActiveEdges === null)
		{
			edge.PrevInAEL = null;
			edge.NextInAEL = null;
			this.m_ActiveEdges = edge;
		}
		else if (startEdge === null && this.E2InsertsBeforeE1(this.m_ActiveEdges, edge))
		{
			edge.PrevInAEL = null;
			edge.NextInAEL = this.m_ActiveEdges;
			this.m_ActiveEdges.PrevInAEL = edge;
			this.m_ActiveEdges = edge;
		}
		else
		{
			if (startEdge === null)
				startEdge = this.m_ActiveEdges;
			while (startEdge.NextInAEL !== null && !this.E2InsertsBeforeE1(startEdge.NextInAEL, edge))
				startEdge = startEdge.NextInAEL;
			edge.NextInAEL = startEdge.NextInAEL;
			if (startEdge.NextInAEL !== null)
				startEdge.NextInAEL.PrevInAEL = edge;
			edge.PrevInAEL = startEdge;
			startEdge.NextInAEL = edge;
		}
	};

	ClipperLib.Clipper.prototype.E2InsertsBeforeE1 = function (e1, e2)
	{
		if (e2.Curr.X === e1.Curr.X)
		{
			if (e2.Top.Y > e1.Top.Y)
				return e2.Top.X < ClipperLib.Clipper.TopX(e1, e2.Top.Y);
			else
				return e1.Top.X > ClipperLib.Clipper.TopX(e2, e1.Top.Y);
		}
		else
			return e2.Curr.X < e1.Curr.X;
	};

	ClipperLib.Clipper.prototype.IsEvenOddFillType = function (edge)
	{
		if (edge.PolyTyp === ClipperLib.PolyType.ptSubject)
			return this.m_SubjFillType === ClipperLib.PolyFillType.pftEvenOdd;
		else
			return this.m_ClipFillType === ClipperLib.PolyFillType.pftEvenOdd;
	};

	ClipperLib.Clipper.prototype.IsEvenOddAltFillType = function (edge)
	{
		if (edge.PolyTyp === ClipperLib.PolyType.ptSubject)
			return this.m_ClipFillType === ClipperLib.PolyFillType.pftEvenOdd;
		else
			return this.m_SubjFillType === ClipperLib.PolyFillType.pftEvenOdd;
	};

	ClipperLib.Clipper.prototype.IsContributing = function (edge)
	{
		var pft, pft2;
		if (edge.PolyTyp === ClipperLib.PolyType.ptSubject)
		{
			pft = this.m_SubjFillType;
			pft2 = this.m_ClipFillType;
		}
		else
		{
			pft = this.m_ClipFillType;
			pft2 = this.m_SubjFillType;
		}
		switch (pft)
		{
		case ClipperLib.PolyFillType.pftEvenOdd:
			if (edge.WindDelta === 0 && edge.WindCnt !== 1)
				return false;
			break;
		case ClipperLib.PolyFillType.pftNonZero:
			if (Math.abs(edge.WindCnt) !== 1)
				return false;
			break;
		case ClipperLib.PolyFillType.pftPositive:
			if (edge.WindCnt !== 1)
				return false;
			break;
		default:
			if (edge.WindCnt !== -1)
				return false;
			break;
		}
		switch (this.m_ClipType)
		{
		case ClipperLib.ClipType.ctIntersection:
			switch (pft2)
			{
			case ClipperLib.PolyFillType.pftEvenOdd:
			case ClipperLib.PolyFillType.pftNonZero:
				return (edge.WindCnt2 !== 0);
			case ClipperLib.PolyFillType.pftPositive:
				return (edge.WindCnt2 > 0);
			default:
				return (edge.WindCnt2 < 0);
			}
		case ClipperLib.ClipType.ctUnion:
			switch (pft2)
			{
			case ClipperLib.PolyFillType.pftEvenOdd:
			case ClipperLib.PolyFillType.pftNonZero:
				return (edge.WindCnt2 === 0);
			case ClipperLib.PolyFillType.pftPositive:
				return (edge.WindCnt2 <= 0);
			default:
				return (edge.WindCnt2 >= 0);
			}
		case ClipperLib.ClipType.ctDifference:
			if (edge.PolyTyp === ClipperLib.PolyType.ptSubject)
				switch (pft2)
				{
				case ClipperLib.PolyFillType.pftEvenOdd:
				case ClipperLib.PolyFillType.pftNonZero:
					return (edge.WindCnt2 === 0);
				case ClipperLib.PolyFillType.pftPositive:
					return (edge.WindCnt2 <= 0);
				default:
					return (edge.WindCnt2 >= 0);
				}
			else
				switch (pft2)
				{
				case ClipperLib.PolyFillType.pftEvenOdd:
				case ClipperLib.PolyFillType.pftNonZero:
					return (edge.WindCnt2 !== 0);
				case ClipperLib.PolyFillType.pftPositive:
					return (edge.WindCnt2 > 0);
				default:
					return (edge.WindCnt2 < 0);
				}
		case ClipperLib.ClipType.ctXor:
			if (edge.WindDelta === 0)
				switch (pft2)
				{
				case ClipperLib.PolyFillType.pftEvenOdd:
				case ClipperLib.PolyFillType.pftNonZero:
					return (edge.WindCnt2 === 0);
				case ClipperLib.PolyFillType.pftPositive:
					return (edge.WindCnt2 <= 0);
				default:
					return (edge.WindCnt2 >= 0);
				}
			else
				return true;
		}
		return true;
	};

	ClipperLib.Clipper.prototype.SetWindingCount = function (edge)
	{
		var e = edge.PrevInAEL;
		//find the edge of the same polytype that immediately preceeds 'edge' in AEL
		while (e !== null && ((e.PolyTyp !== edge.PolyTyp) || (e.WindDelta === 0)))
			e = e.PrevInAEL;
		if (e === null)
		{
			var pft = (edge.PolyTyp === ClipperLib.PolyType.ptSubject ? this.m_SubjFillType : this.m_ClipFillType);
			if (edge.WindDelta === 0)
			{
				edge.WindCnt = (pft === ClipperLib.PolyFillType.pftNegative ? -1 : 1);
			}
			else
			{
				edge.WindCnt = edge.WindDelta;
			}
			edge.WindCnt2 = 0;
			e = this.m_ActiveEdges;
			//ie get ready to calc WindCnt2
		}
		else if (edge.WindDelta === 0 && this.m_ClipType !== ClipperLib.ClipType.ctUnion)
		{
			edge.WindCnt = 1;
			edge.WindCnt2 = e.WindCnt2;
			e = e.NextInAEL;
			//ie get ready to calc WindCnt2
		}
		else if (this.IsEvenOddFillType(edge))
		{
			//EvenOdd filling ...
			if (edge.WindDelta === 0)
			{
				//are we inside a subj polygon ...
				var Inside = true;
				var e2 = e.PrevInAEL;
				while (e2 !== null)
				{
					if (e2.PolyTyp === e.PolyTyp && e2.WindDelta !== 0)
						Inside = !Inside;
					e2 = e2.PrevInAEL;
				}
				edge.WindCnt = (Inside ? 0 : 1);
			}
			else
			{
				edge.WindCnt = edge.WindDelta;
			}
			edge.WindCnt2 = e.WindCnt2;
			e = e.NextInAEL;
			//ie get ready to calc WindCnt2
		}
		else
		{
			//nonZero, Positive or Negative filling ...
			if (e.WindCnt * e.WindDelta < 0)
			{
				//prev edge is 'decreasing' WindCount (WC) toward zero
				//so we're outside the previous polygon ...
				if (Math.abs(e.WindCnt) > 1)
				{
					//outside prev poly but still inside another.
					//when reversing direction of prev poly use the same WC
					if (e.WindDelta * edge.WindDelta < 0)
						edge.WindCnt = e.WindCnt;
					else
						edge.WindCnt = e.WindCnt + edge.WindDelta;
				}
				else
					edge.WindCnt = (edge.WindDelta === 0 ? 1 : edge.WindDelta);
			}
			else
			{
				//prev edge is 'increasing' WindCount (WC) away from zero
				//so we're inside the previous polygon ...
				if (edge.WindDelta === 0)
					edge.WindCnt = (e.WindCnt < 0 ? e.WindCnt - 1 : e.WindCnt + 1);
				else if (e.WindDelta * edge.WindDelta < 0)
					edge.WindCnt = e.WindCnt;
				else
					edge.WindCnt = e.WindCnt + edge.WindDelta;
			}
			edge.WindCnt2 = e.WindCnt2;
			e = e.NextInAEL;
			//ie get ready to calc WindCnt2
		}
		//update WindCnt2 ...
		if (this.IsEvenOddAltFillType(edge))
		{
			//EvenOdd filling ...
			while (e !== edge)
			{
				if (e.WindDelta !== 0)
					edge.WindCnt2 = (edge.WindCnt2 === 0 ? 1 : 0);
				e = e.NextInAEL;
			}
		}
		else
		{
			//nonZero, Positive or Negative filling ...
			while (e !== edge)
			{
				edge.WindCnt2 += e.WindDelta;
				e = e.NextInAEL;
			}
		}
	};

	ClipperLib.Clipper.prototype.AddEdgeToSEL = function (edge)
	{
		//SEL pointers in PEdge are use to build transient lists of horizontal edges.
		//However, since we don't need to worry about processing order, all additions
		//are made to the front of the list ...
		if (this.m_SortedEdges === null)
		{
			this.m_SortedEdges = edge;
			edge.PrevInSEL = null;
			edge.NextInSEL = null;
		}
		else
		{
			edge.NextInSEL = this.m_SortedEdges;
			edge.PrevInSEL = null;
			this.m_SortedEdges.PrevInSEL = edge;
			this.m_SortedEdges = edge;
		}
	};

	ClipperLib.Clipper.prototype.PopEdgeFromSEL = function (e)
	{
		//Pop edge from front of SEL (ie SEL is a FILO list)
		e.v = this.m_SortedEdges;
		if (e.v === null)
		{
			return false;
		}
		var oldE = e.v;
		this.m_SortedEdges = e.v.NextInSEL;
		if (this.m_SortedEdges !== null)
		{
			this.m_SortedEdges.PrevInSEL = null;
		}
		oldE.NextInSEL = null;
		oldE.PrevInSEL = null;
		return true;
	};

	ClipperLib.Clipper.prototype.CopyAELToSEL = function ()
	{
		var e = this.m_ActiveEdges;
		this.m_SortedEdges = e;
		while (e !== null)
		{
			e.PrevInSEL = e.PrevInAEL;
			e.NextInSEL = e.NextInAEL;
			e = e.NextInAEL;
		}
	};

	ClipperLib.Clipper.prototype.SwapPositionsInSEL = function (edge1, edge2)
	{
		if (edge1.NextInSEL === null && edge1.PrevInSEL === null)
			return;
		if (edge2.NextInSEL === null && edge2.PrevInSEL === null)
			return;
		if (edge1.NextInSEL === edge2)
		{
			var next = edge2.NextInSEL;
			if (next !== null)
				next.PrevInSEL = edge1;
			var prev = edge1.PrevInSEL;
			if (prev !== null)
				prev.NextInSEL = edge2;
			edge2.PrevInSEL = prev;
			edge2.NextInSEL = edge1;
			edge1.PrevInSEL = edge2;
			edge1.NextInSEL = next;
		}
		else if (edge2.NextInSEL === edge1)
		{
			var next = edge1.NextInSEL;
			if (next !== null)
				next.PrevInSEL = edge2;
			var prev = edge2.PrevInSEL;
			if (prev !== null)
				prev.NextInSEL = edge1;
			edge1.PrevInSEL = prev;
			edge1.NextInSEL = edge2;
			edge2.PrevInSEL = edge1;
			edge2.NextInSEL = next;
		}
		else
		{
			var next = edge1.NextInSEL;
			var prev = edge1.PrevInSEL;
			edge1.NextInSEL = edge2.NextInSEL;
			if (edge1.NextInSEL !== null)
				edge1.NextInSEL.PrevInSEL = edge1;
			edge1.PrevInSEL = edge2.PrevInSEL;
			if (edge1.PrevInSEL !== null)
				edge1.PrevInSEL.NextInSEL = edge1;
			edge2.NextInSEL = next;
			if (edge2.NextInSEL !== null)
				edge2.NextInSEL.PrevInSEL = edge2;
			edge2.PrevInSEL = prev;
			if (edge2.PrevInSEL !== null)
				edge2.PrevInSEL.NextInSEL = edge2;
		}
		if (edge1.PrevInSEL === null)
			this.m_SortedEdges = edge1;
		else if (edge2.PrevInSEL === null)
			this.m_SortedEdges = edge2;
	};

	ClipperLib.Clipper.prototype.AddLocalMaxPoly = function (e1, e2, pt)
	{
		this.AddOutPt(e1, pt);
		if (e2.WindDelta === 0) this.AddOutPt(e2, pt);
		if (e1.OutIdx === e2.OutIdx)
		{
			e1.OutIdx = -1;
			e2.OutIdx = -1;
		}
		else if (e1.OutIdx < e2.OutIdx)
			this.AppendPolygon(e1, e2);
		else
			this.AppendPolygon(e2, e1);
	};

	ClipperLib.Clipper.prototype.AddLocalMinPoly = function (e1, e2, pt)
	{
		var result;
		var e, prevE;
		if (ClipperLib.ClipperBase.IsHorizontal(e2) || (e1.Dx > e2.Dx))
		{
			result = this.AddOutPt(e1, pt);
			e2.OutIdx = e1.OutIdx;
			e1.Side = ClipperLib.EdgeSide.esLeft;
			e2.Side = ClipperLib.EdgeSide.esRight;
			e = e1;
			if (e.PrevInAEL === e2)
				prevE = e2.PrevInAEL;
			else
				prevE = e.PrevInAEL;
		}
		else
		{
			result = this.AddOutPt(e2, pt);
			e1.OutIdx = e2.OutIdx;
			e1.Side = ClipperLib.EdgeSide.esRight;
			e2.Side = ClipperLib.EdgeSide.esLeft;
			e = e2;
			if (e.PrevInAEL === e1)
				prevE = e1.PrevInAEL;
			else
				prevE = e.PrevInAEL;
		}

		if (prevE !== null && prevE.OutIdx >= 0 && prevE.Top.Y < pt.Y && e.Top.Y < pt.Y)
		{
			var xPrev = ClipperLib.Clipper.TopX(prevE, pt.Y);
			var xE = ClipperLib.Clipper.TopX(e, pt.Y);
			if ((xPrev === xE) && (e.WindDelta !== 0) && (prevE.WindDelta !== 0) && ClipperLib.ClipperBase.SlopesEqual5(new ClipperLib.FPoint2(xPrev, pt.Y), prevE.Top, new ClipperLib.FPoint2(xE, pt.Y), e.Top))
			{
				var outPt = this.AddOutPt(prevE, pt);
				this.AddJoin(result, outPt, e.Top);
			}
		}
		return result;
	};

	ClipperLib.Clipper.prototype.AddOutPt = function (e, pt)
	{
		if (e.OutIdx < 0)
		{
			var outRec = this.CreateOutRec();
			outRec.IsOpen = (e.WindDelta === 0);
			var newOp = new ClipperLib.OutPt();
			outRec.Pts = newOp;
			newOp.Idx = outRec.Idx;
			//newOp.Pt = pt;
			newOp.Pt.X = pt.X;
			newOp.Pt.Y = pt.Y;
			if (ClipperLib.use_xyz) newOp.Pt.Z = pt.Z;
			newOp.Next = newOp;
			newOp.Prev = newOp;
			if (!outRec.IsOpen)
				this.SetHoleState(e, outRec);
			e.OutIdx = outRec.Idx;
			//nb: do this after SetZ !
			return newOp;
		}
		else
		{
			var outRec = this.m_PolyOuts[e.OutIdx];
			//OutRec.Pts is the 'Left-most' point & OutRec.Pts.Prev is the 'Right-most'
			var op = outRec.Pts;
			var ToFront = (e.Side === ClipperLib.EdgeSide.esLeft);
			if (ToFront && ClipperLib.FPoint.op_Equality(pt, op.Pt))
				return op;
			else if (!ToFront && ClipperLib.FPoint.op_Equality(pt, op.Prev.Pt))
				return op.Prev;
			var newOp = new ClipperLib.OutPt();
			newOp.Idx = outRec.Idx;
			//newOp.Pt = pt;
			newOp.Pt.X = pt.X;
			newOp.Pt.Y = pt.Y;
			if (ClipperLib.use_xyz) newOp.Pt.Z = pt.Z;
			newOp.Next = op;
			newOp.Prev = op.Prev;
			newOp.Prev.Next = newOp;
			op.Prev = newOp;
			if (ToFront)
				outRec.Pts = newOp;
			return newOp;
		}
	};

	ClipperLib.Clipper.prototype.GetLastOutPt = function (e)
	{
		var outRec = this.m_PolyOuts[e.OutIdx];
		if (e.Side === ClipperLib.EdgeSide.esLeft)
		{
			return outRec.Pts;
		}
		else
		{
			return outRec.Pts.Prev;
		}
	};

	ClipperLib.Clipper.prototype.SwapPoints = function (pt1, pt2)
	{
		var tmp = new ClipperLib.FPoint1(pt1.Value);
		//pt1.Value = pt2.Value;
		pt1.Value.X = pt2.Value.X;
		pt1.Value.Y = pt2.Value.Y;
		if (ClipperLib.use_xyz) pt1.Value.Z = pt2.Value.Z;
		//pt2.Value = tmp;
		pt2.Value.X = tmp.X;
		pt2.Value.Y = tmp.Y;
		if (ClipperLib.use_xyz) pt2.Value.Z = tmp.Z;
	};

	ClipperLib.Clipper.prototype.HorzSegmentsOverlap = function (seg1a, seg1b, seg2a, seg2b)
	{
		var tmp;
		if (seg1a > seg1b)
		{
			tmp = seg1a;
			seg1a = seg1b;
			seg1b = tmp;
		}
		if (seg2a > seg2b)
		{
			tmp = seg2a;
			seg2a = seg2b;
			seg2b = tmp;
		}
		return (seg1a < seg2b) && (seg2a < seg1b);
	}

	ClipperLib.Clipper.prototype.SetHoleState = function (e, outRec)
	{
		var e2 = e.PrevInAEL;
		var eTmp = null;
		while (e2 !== null)
		{
			if (e2.OutIdx >= 0 && e2.WindDelta !== 0)
			{
				if (eTmp === null)
					eTmp = e2;
				else if (eTmp.OutIdx === e2.OutIdx)
					eTmp = null; //paired
			}
			e2 = e2.PrevInAEL;
		}

		if (eTmp === null)
		{
			outRec.FirstLeft = null;
			outRec.IsHole = false;
		}
		else
		{
			outRec.FirstLeft = this.m_PolyOuts[eTmp.OutIdx];
			outRec.IsHole = !outRec.FirstLeft.IsHole;
		}
	};

	ClipperLib.Clipper.prototype.GetDx = function (pt1, pt2)
	{
		if (pt1.Y === pt2.Y)
			return ClipperLib.ClipperBase.horizontal;
		else
			return (pt2.X - pt1.X) / (pt2.Y - pt1.Y);
	};

	ClipperLib.Clipper.prototype.FirstIsBottomPt = function (btmPt1, btmPt2)
	{
		var p = btmPt1.Prev;
		while ((ClipperLib.FPoint.op_Equality(p.Pt, btmPt1.Pt)) && (p !== btmPt1))
			p = p.Prev;
		var dx1p = Math.abs(this.GetDx(btmPt1.Pt, p.Pt));
		p = btmPt1.Next;
		while ((ClipperLib.FPoint.op_Equality(p.Pt, btmPt1.Pt)) && (p !== btmPt1))
			p = p.Next;
		var dx1n = Math.abs(this.GetDx(btmPt1.Pt, p.Pt));
		p = btmPt2.Prev;
		while ((ClipperLib.FPoint.op_Equality(p.Pt, btmPt2.Pt)) && (p !== btmPt2))
			p = p.Prev;
		var dx2p = Math.abs(this.GetDx(btmPt2.Pt, p.Pt));
		p = btmPt2.Next;
		while ((ClipperLib.FPoint.op_Equality(p.Pt, btmPt2.Pt)) && (p !== btmPt2))
			p = p.Next;
		var dx2n = Math.abs(this.GetDx(btmPt2.Pt, p.Pt));

		if (Math.max(dx1p, dx1n) === Math.max(dx2p, dx2n) && Math.min(dx1p, dx1n) === Math.min(dx2p, dx2n))
		{
			return this.Area(btmPt1) > 0; //if otherwise identical use orientation
		}
		else
		{
			return (dx1p >= dx2p && dx1p >= dx2n) || (dx1n >= dx2p && dx1n >= dx2n);
		}
	};

	ClipperLib.Clipper.prototype.GetBottomPt = function (pp)
	{
		var dups = null;
		var p = pp.Next;
		while (p !== pp)
		{
			if (p.Pt.Y > pp.Pt.Y)
			{
				pp = p;
				dups = null;
			}
			else if (p.Pt.Y === pp.Pt.Y && p.Pt.X <= pp.Pt.X)
			{
				if (p.Pt.X < pp.Pt.X)
				{
					dups = null;
					pp = p;
				}
				else
				{
					if (p.Next !== pp && p.Prev !== pp)
						dups = p;
				}
			}
			p = p.Next;
		}
		if (dups !== null)
		{
			//there appears to be at least 2 vertices at bottomPt so ...
			while (dups !== p)
			{
				if (!this.FirstIsBottomPt(p, dups))
					pp = dups;
				dups = dups.Next;
				while (ClipperLib.FPoint.op_Inequality(dups.Pt, pp.Pt))
					dups = dups.Next;
			}
		}
		return pp;
	};

	ClipperLib.Clipper.prototype.GetLowermostRec = function (outRec1, outRec2)
	{
		//work out which polygon fragment has the correct hole state ...
		if (outRec1.BottomPt === null)
			outRec1.BottomPt = this.GetBottomPt(outRec1.Pts);
		if (outRec2.BottomPt === null)
			outRec2.BottomPt = this.GetBottomPt(outRec2.Pts);
		var bPt1 = outRec1.BottomPt;
		var bPt2 = outRec2.BottomPt;
		if (bPt1.Pt.Y > bPt2.Pt.Y)
			return outRec1;
		else if (bPt1.Pt.Y < bPt2.Pt.Y)
			return outRec2;
		else if (bPt1.Pt.X < bPt2.Pt.X)
			return outRec1;
		else if (bPt1.Pt.X > bPt2.Pt.X)
			return outRec2;
		else if (bPt1.Next === bPt1)
			return outRec2;
		else if (bPt2.Next === bPt2)
			return outRec1;
		else if (this.FirstIsBottomPt(bPt1, bPt2))
			return outRec1;
		else
			return outRec2;
	};

	ClipperLib.Clipper.prototype.OutRec1RightOfOutRec2 = function (outRec1, outRec2)
	{
		do {
			outRec1 = outRec1.FirstLeft;
			if (outRec1 === outRec2)
				return true;
		}
		while (outRec1 !== null)
		return false;
	};

	ClipperLib.Clipper.prototype.GetOutRec = function (idx)
	{
		var outrec = this.m_PolyOuts[idx];
		while (outrec !== this.m_PolyOuts[outrec.Idx])
			outrec = this.m_PolyOuts[outrec.Idx];
		return outrec;
	};

	ClipperLib.Clipper.prototype.AppendPolygon = function (e1, e2)
	{
		//get the start and ends of both output polygons ...
		var outRec1 = this.m_PolyOuts[e1.OutIdx];
		var outRec2 = this.m_PolyOuts[e2.OutIdx];
		var holeStateRec;
		if (this.OutRec1RightOfOutRec2(outRec1, outRec2))
			holeStateRec = outRec2;
		else if (this.OutRec1RightOfOutRec2(outRec2, outRec1))
			holeStateRec = outRec1;
		else
			holeStateRec = this.GetLowermostRec(outRec1, outRec2);

		//get the start and ends of both output polygons and
		//join E2 poly onto E1 poly and delete pointers to E2 ...

		var p1_lft = outRec1.Pts;
		var p1_rt = p1_lft.Prev;
		var p2_lft = outRec2.Pts;
		var p2_rt = p2_lft.Prev;
		//join e2 poly onto e1 poly and delete pointers to e2 ...
		if (e1.Side === ClipperLib.EdgeSide.esLeft)
		{
			if (e2.Side === ClipperLib.EdgeSide.esLeft)
			{
				//z y x a b c
				this.ReversePolyPtLinks(p2_lft);
				p2_lft.Next = p1_lft;
				p1_lft.Prev = p2_lft;
				p1_rt.Next = p2_rt;
				p2_rt.Prev = p1_rt;
				outRec1.Pts = p2_rt;
			}
			else
			{
				//x y z a b c
				p2_rt.Next = p1_lft;
				p1_lft.Prev = p2_rt;
				p2_lft.Prev = p1_rt;
				p1_rt.Next = p2_lft;
				outRec1.Pts = p2_lft;
			}
		}
		else
		{
			if (e2.Side === ClipperLib.EdgeSide.esRight)
			{
				//a b c z y x
				this.ReversePolyPtLinks(p2_lft);
				p1_rt.Next = p2_rt;
				p2_rt.Prev = p1_rt;
				p2_lft.Next = p1_lft;
				p1_lft.Prev = p2_lft;
			}
			else
			{
				//a b c x y z
				p1_rt.Next = p2_lft;
				p2_lft.Prev = p1_rt;
				p1_lft.Prev = p2_rt;
				p2_rt.Next = p1_lft;
			}
		}
		outRec1.BottomPt = null;
		if (holeStateRec === outRec2)
		{
			if (outRec2.FirstLeft !== outRec1)
				outRec1.FirstLeft = outRec2.FirstLeft;
			outRec1.IsHole = outRec2.IsHole;
		}
		outRec2.Pts = null;
		outRec2.BottomPt = null;
		outRec2.FirstLeft = outRec1;
		var OKIdx = e1.OutIdx;
		var ObsoleteIdx = e2.OutIdx;
		e1.OutIdx = -1;
		//nb: safe because we only get here via AddLocalMaxPoly
		e2.OutIdx = -1;
		var e = this.m_ActiveEdges;
		while (e !== null)
		{
			if (e.OutIdx === ObsoleteIdx)
			{
				e.OutIdx = OKIdx;
				e.Side = e1.Side;
				break;
			}
			e = e.NextInAEL;
		}
		outRec2.Idx = outRec1.Idx;
	};

	ClipperLib.Clipper.prototype.ReversePolyPtLinks = function (pp)
	{
		if (pp === null)
			return;
		var pp1;
		var pp2;
		pp1 = pp;
		do {
			pp2 = pp1.Next;
			pp1.Next = pp1.Prev;
			pp1.Prev = pp2;
			pp1 = pp2;
		}
		while (pp1 !== pp)
	};

	ClipperLib.Clipper.SwapSides = function (edge1, edge2)
	{
		var side = edge1.Side;
		edge1.Side = edge2.Side;
		edge2.Side = side;
	};

	ClipperLib.Clipper.SwapPolyIndexes = function (edge1, edge2)
	{
		var outIdx = edge1.OutIdx;
		edge1.OutIdx = edge2.OutIdx;
		edge2.OutIdx = outIdx;
	};

	ClipperLib.Clipper.prototype.IntersectEdges = function (e1, e2, pt)
	{
		//e1 will be to the left of e2 BELOW the intersection. Therefore e1 is before
		//e2 in AEL except when e1 is being inserted at the intersection point ...
		var e1Contributing = (e1.OutIdx >= 0);
		var e2Contributing = (e2.OutIdx >= 0);

		if (ClipperLib.use_xyz)
			this.SetZ(pt, e1, e2);

		if (ClipperLib.use_lines)
		{
			//if either edge is on an OPEN path ...
			if (e1.WindDelta === 0 || e2.WindDelta === 0)
			{
				//ignore subject-subject open path intersections UNLESS they
				//are both open paths, AND they are both 'contributing maximas' ...
				if (e1.WindDelta === 0 && e2.WindDelta === 0) return;
				//if intersecting a subj line with a subj poly ...
				else if (e1.PolyTyp === e2.PolyTyp &&
					e1.WindDelta !== e2.WindDelta && this.m_ClipType === ClipperLib.ClipType.ctUnion)
				{
					if (e1.WindDelta === 0)
					{
						if (e2Contributing)
						{
							this.AddOutPt(e1, pt);
							if (e1Contributing)
								e1.OutIdx = -1;
						}
					}
					else
					{
						if (e1Contributing)
						{
							this.AddOutPt(e2, pt);
							if (e2Contributing)
								e2.OutIdx = -1;
						}
					}
				}
				else if (e1.PolyTyp !== e2.PolyTyp)
				{
					if ((e1.WindDelta === 0) && Math.abs(e2.WindCnt) === 1 &&
						(this.m_ClipType !== ClipperLib.ClipType.ctUnion || e2.WindCnt2 === 0))
					{
						this.AddOutPt(e1, pt);
						if (e1Contributing)
							e1.OutIdx = -1;
					}
					else if ((e2.WindDelta === 0) && (Math.abs(e1.WindCnt) === 1) &&
						(this.m_ClipType !== ClipperLib.ClipType.ctUnion || e1.WindCnt2 === 0))
					{
						this.AddOutPt(e2, pt);
						if (e2Contributing)
							e2.OutIdx = -1;
					}
				}
				return;
			}
		}
		//update winding counts...
		//assumes that e1 will be to the Right of e2 ABOVE the intersection
		if (e1.PolyTyp === e2.PolyTyp)
		{
			if (this.IsEvenOddFillType(e1))
			{
				var oldE1WindCnt = e1.WindCnt;
				e1.WindCnt = e2.WindCnt;
				e2.WindCnt = oldE1WindCnt;
			}
			else
			{
				if (e1.WindCnt + e2.WindDelta === 0)
					e1.WindCnt = -e1.WindCnt;
				else
					e1.WindCnt += e2.WindDelta;
				if (e2.WindCnt - e1.WindDelta === 0)
					e2.WindCnt = -e2.WindCnt;
				else
					e2.WindCnt -= e1.WindDelta;
			}
		}
		else
		{
			if (!this.IsEvenOddFillType(e2))
				e1.WindCnt2 += e2.WindDelta;
			else
				e1.WindCnt2 = (e1.WindCnt2 === 0) ? 1 : 0;
			if (!this.IsEvenOddFillType(e1))
				e2.WindCnt2 -= e1.WindDelta;
			else
				e2.WindCnt2 = (e2.WindCnt2 === 0) ? 1 : 0;
		}
		var e1FillType, e2FillType, e1FillType2, e2FillType2;
		if (e1.PolyTyp === ClipperLib.PolyType.ptSubject)
		{
			e1FillType = this.m_SubjFillType;
			e1FillType2 = this.m_ClipFillType;
		}
		else
		{
			e1FillType = this.m_ClipFillType;
			e1FillType2 = this.m_SubjFillType;
		}
		if (e2.PolyTyp === ClipperLib.PolyType.ptSubject)
		{
			e2FillType = this.m_SubjFillType;
			e2FillType2 = this.m_ClipFillType;
		}
		else
		{
			e2FillType = this.m_ClipFillType;
			e2FillType2 = this.m_SubjFillType;
		}
		var e1Wc, e2Wc;
		switch (e1FillType)
		{
		case ClipperLib.PolyFillType.pftPositive:
			e1Wc = e1.WindCnt;
			break;
		case ClipperLib.PolyFillType.pftNegative:
			e1Wc = -e1.WindCnt;
			break;
		default:
			e1Wc = Math.abs(e1.WindCnt);
			break;
		}
		switch (e2FillType)
		{
		case ClipperLib.PolyFillType.pftPositive:
			e2Wc = e2.WindCnt;
			break;
		case ClipperLib.PolyFillType.pftNegative:
			e2Wc = -e2.WindCnt;
			break;
		default:
			e2Wc = Math.abs(e2.WindCnt);
			break;
		}
		if (e1Contributing && e2Contributing)
		{
			if ((e1Wc !== 0 && e1Wc !== 1) || (e2Wc !== 0 && e2Wc !== 1) ||
				(e1.PolyTyp !== e2.PolyTyp && this.m_ClipType !== ClipperLib.ClipType.ctXor))
			{
				this.AddLocalMaxPoly(e1, e2, pt);
			}
			else
			{
				this.AddOutPt(e1, pt);
				this.AddOutPt(e2, pt);
				ClipperLib.Clipper.SwapSides(e1, e2);
				ClipperLib.Clipper.SwapPolyIndexes(e1, e2);
			}
		}
		else if (e1Contributing)
		{
			if (e2Wc === 0 || e2Wc === 1)
			{
				this.AddOutPt(e1, pt);
				ClipperLib.Clipper.SwapSides(e1, e2);
				ClipperLib.Clipper.SwapPolyIndexes(e1, e2);
			}
		}
		else if (e2Contributing)
		{
			if (e1Wc === 0 || e1Wc === 1)
			{
				this.AddOutPt(e2, pt);
				ClipperLib.Clipper.SwapSides(e1, e2);
				ClipperLib.Clipper.SwapPolyIndexes(e1, e2);
			}
		}
		else if ((e1Wc === 0 || e1Wc === 1) && (e2Wc === 0 || e2Wc === 1))
		{
			//neither edge is currently contributing ...
			var e1Wc2, e2Wc2;
			switch (e1FillType2)
			{
			case ClipperLib.PolyFillType.pftPositive:
				e1Wc2 = e1.WindCnt2;
				break;
			case ClipperLib.PolyFillType.pftNegative:
				e1Wc2 = -e1.WindCnt2;
				break;
			default:
				e1Wc2 = Math.abs(e1.WindCnt2);
				break;
			}
			switch (e2FillType2)
			{
			case ClipperLib.PolyFillType.pftPositive:
				e2Wc2 = e2.WindCnt2;
				break;
			case ClipperLib.PolyFillType.pftNegative:
				e2Wc2 = -e2.WindCnt2;
				break;
			default:
				e2Wc2 = Math.abs(e2.WindCnt2);
				break;
			}
			if (e1.PolyTyp !== e2.PolyTyp)
			{
				this.AddLocalMinPoly(e1, e2, pt);
			}
			else if (e1Wc === 1 && e2Wc === 1)
				switch (this.m_ClipType)
				{
				case ClipperLib.ClipType.ctIntersection:
					if (e1Wc2 > 0 && e2Wc2 > 0)
						this.AddLocalMinPoly(e1, e2, pt);
					break;
				case ClipperLib.ClipType.ctUnion:
					if (e1Wc2 <= 0 && e2Wc2 <= 0)
						this.AddLocalMinPoly(e1, e2, pt);
					break;
				case ClipperLib.ClipType.ctDifference:
					if (((e1.PolyTyp === ClipperLib.PolyType.ptClip) && (e1Wc2 > 0) && (e2Wc2 > 0)) ||
						((e1.PolyTyp === ClipperLib.PolyType.ptSubject) && (e1Wc2 <= 0) && (e2Wc2 <= 0)))
						this.AddLocalMinPoly(e1, e2, pt);
					break;
				case ClipperLib.ClipType.ctXor:
					this.AddLocalMinPoly(e1, e2, pt);
					break;
				}
			else
				ClipperLib.Clipper.SwapSides(e1, e2);
		}
	};

	ClipperLib.Clipper.prototype.DeleteFromSEL = function (e)
	{
		var SelPrev = e.PrevInSEL;
		var SelNext = e.NextInSEL;
		if (SelPrev === null && SelNext === null && (e !== this.m_SortedEdges))
			return;
		//already deleted
		if (SelPrev !== null)
			SelPrev.NextInSEL = SelNext;
		else
			this.m_SortedEdges = SelNext;
		if (SelNext !== null)
			SelNext.PrevInSEL = SelPrev;
		e.NextInSEL = null;
		e.PrevInSEL = null;
	};

	ClipperLib.Clipper.prototype.ProcessHorizontals = function ()
	{
		var horzEdge = {}; //m_SortedEdges;
		while (this.PopEdgeFromSEL(horzEdge))
		{
			this.ProcessHorizontal(horzEdge.v);
		}
	};

	ClipperLib.Clipper.prototype.GetHorzDirection = function (HorzEdge, $var)
	{
		if (HorzEdge.Bot.X < HorzEdge.Top.X)
		{
			$var.Left = HorzEdge.Bot.X;
			$var.Right = HorzEdge.Top.X;
			$var.Dir = ClipperLib.Direction.dLeftToRight;
		}
		else
		{
			$var.Left = HorzEdge.Top.X;
			$var.Right = HorzEdge.Bot.X;
			$var.Dir = ClipperLib.Direction.dRightToLeft;
		}
	};

	ClipperLib.Clipper.prototype.ProcessHorizontal = function (horzEdge)
	{
		var $var = {
			Dir: null,
			Left: null,
			Right: null
		};

		this.GetHorzDirection(horzEdge, $var);
		var dir = $var.Dir;
		var horzLeft = $var.Left;
		var horzRight = $var.Right;

		var IsOpen = horzEdge.WindDelta === 0;

		var eLastHorz = horzEdge,
			eMaxPair = null;
		while (eLastHorz.NextInLML !== null && ClipperLib.ClipperBase.IsHorizontal(eLastHorz.NextInLML))
			eLastHorz = eLastHorz.NextInLML;
		if (eLastHorz.NextInLML === null)
			eMaxPair = this.GetMaximaPair(eLastHorz);

		var currMax = this.m_Maxima;
		if (currMax !== null)
		{
			//get the first maxima in range (X) ...
			if (dir === ClipperLib.Direction.dLeftToRight)
			{
				while (currMax !== null && currMax.X <= horzEdge.Bot.X)
				{
					currMax = currMax.Next;
				}
				if (currMax !== null && currMax.X >= eLastHorz.Top.X)
				{
					currMax = null;
				}
			}
			else
			{
				while (currMax.Next !== null && currMax.Next.X < horzEdge.Bot.X)
				{
					currMax = currMax.Next;
				}
				if (currMax.X <= eLastHorz.Top.X)
				{
					currMax = null;
				}
			}
		}
		var op1 = null;
		for (;;) //loop through consec. horizontal edges
		{
			var IsLastHorz = (horzEdge === eLastHorz);
			var e = this.GetNextInAEL(horzEdge, dir);
			while (e !== null)
			{
				//this code block inserts extra coords into horizontal edges (in output
				//polygons) whereever maxima touch these horizontal edges. This helps
				//'simplifying' polygons (ie if the Simplify property is set).
				if (currMax !== null)
				{
					if (dir === ClipperLib.Direction.dLeftToRight)
					{
						while (currMax !== null && currMax.X < e.Curr.X)
						{
							if (horzEdge.OutIdx >= 0 && !IsOpen)
							{
								this.AddOutPt(horzEdge, new ClipperLib.FPoint2(currMax.X, horzEdge.Bot.Y));
							}
							currMax = currMax.Next;
						}
					}
					else
					{
						while (currMax !== null && currMax.X > e.Curr.X)
						{
							if (horzEdge.OutIdx >= 0 && !IsOpen)
							{
								this.AddOutPt(horzEdge, new ClipperLib.FPoint2(currMax.X, horzEdge.Bot.Y));
							}
							currMax = currMax.Prev;
						}
					}
				}

				if ((dir === ClipperLib.Direction.dLeftToRight && e.Curr.X > horzRight) || (dir === ClipperLib.Direction.dRightToLeft && e.Curr.X < horzLeft))
				{
					break;
				}

				//Also break if we've got to the end of an intermediate horizontal edge ...
				//nb: Smaller Dx's are to the right of larger Dx's ABOVE the horizontal.
				if (e.Curr.X === horzEdge.Top.X && horzEdge.NextInLML !== null && e.Dx < horzEdge.NextInLML.Dx)
					break;

				if (horzEdge.OutIdx >= 0 && !IsOpen) //note: may be done multiple times
				{
					if (ClipperLib.use_xyz)
					{
						if (dir === ClipperLib.Direction.dLeftToRight)
							this.SetZ(e.Curr, horzEdge, e);
						else this.SetZ(e.Curr, e, horzEdge);
					}

					op1 = this.AddOutPt(horzEdge, e.Curr);
					var eNextHorz = this.m_SortedEdges;
					while (eNextHorz !== null)
					{
						if (eNextHorz.OutIdx >= 0 && this.HorzSegmentsOverlap(horzEdge.Bot.X, horzEdge.Top.X, eNextHorz.Bot.X, eNextHorz.Top.X))
						{
							var op2 = this.GetLastOutPt(eNextHorz);
							this.AddJoin(op2, op1, eNextHorz.Top);
						}
						eNextHorz = eNextHorz.NextInSEL;
					}
					this.AddGhostJoin(op1, horzEdge.Bot);
				}

				//OK, so far we're still in range of the horizontal Edge  but make sure
				//we're at the last of consec. horizontals when matching with eMaxPair
				if (e === eMaxPair && IsLastHorz)
				{
					if (horzEdge.OutIdx >= 0)
					{
						this.AddLocalMaxPoly(horzEdge, eMaxPair, horzEdge.Top);
					}
					this.DeleteFromAEL(horzEdge);
					this.DeleteFromAEL(eMaxPair);
					return;
				}

				if (dir === ClipperLib.Direction.dLeftToRight)
				{
					var Pt = new ClipperLib.FPoint2(e.Curr.X, horzEdge.Curr.Y);
					this.IntersectEdges(horzEdge, e, Pt);
				}
				else
				{
					var Pt = new ClipperLib.FPoint2(e.Curr.X, horzEdge.Curr.Y);
					this.IntersectEdges(e, horzEdge, Pt);
				}
				var eNext = this.GetNextInAEL(e, dir);
				this.SwapPositionsInAEL(horzEdge, e);
				e = eNext;
			} //end while(e !== null)

			//Break out of loop if HorzEdge.NextInLML is not also horizontal ...
			if (horzEdge.NextInLML === null || !ClipperLib.ClipperBase.IsHorizontal(horzEdge.NextInLML))
			{
				break;
			}

			horzEdge = this.UpdateEdgeIntoAEL(horzEdge);
			if (horzEdge.OutIdx >= 0)
			{
				this.AddOutPt(horzEdge, horzEdge.Bot);
			}

			$var = {
				Dir: dir,
				Left: horzLeft,
				Right: horzRight
			};

			this.GetHorzDirection(horzEdge, $var);
			dir = $var.Dir;
			horzLeft = $var.Left;
			horzRight = $var.Right;

		} //end for (;;)

		if (horzEdge.OutIdx >= 0 && op1 === null)
		{
			op1 = this.GetLastOutPt(horzEdge);
			var eNextHorz = this.m_SortedEdges;
			while (eNextHorz !== null)
			{
				if (eNextHorz.OutIdx >= 0 && this.HorzSegmentsOverlap(horzEdge.Bot.X, horzEdge.Top.X, eNextHorz.Bot.X, eNextHorz.Top.X))
				{
					var op2 = this.GetLastOutPt(eNextHorz);
					this.AddJoin(op2, op1, eNextHorz.Top);
				}
				eNextHorz = eNextHorz.NextInSEL;
			}
			this.AddGhostJoin(op1, horzEdge.Top);
		}

		if (horzEdge.NextInLML !== null)
		{
			if (horzEdge.OutIdx >= 0)
			{
				op1 = this.AddOutPt(horzEdge, horzEdge.Top);

				horzEdge = this.UpdateEdgeIntoAEL(horzEdge);
				if (horzEdge.WindDelta === 0)
				{
					return;
				}
				//nb: HorzEdge is no longer horizontal here
				var ePrev = horzEdge.PrevInAEL;
				var eNext = horzEdge.NextInAEL;
				if (ePrev !== null && ePrev.Curr.X === horzEdge.Bot.X && ePrev.Curr.Y === horzEdge.Bot.Y && ePrev.WindDelta === 0 && (ePrev.OutIdx >= 0 && ePrev.Curr.Y > ePrev.Top.Y && ClipperLib.ClipperBase.SlopesEqual3(horzEdge, ePrev)))
				{
					var op2 = this.AddOutPt(ePrev, horzEdge.Bot);
					this.AddJoin(op1, op2, horzEdge.Top);
				}
				else if (eNext !== null && eNext.Curr.X === horzEdge.Bot.X && eNext.Curr.Y === horzEdge.Bot.Y && eNext.WindDelta !== 0 && eNext.OutIdx >= 0 && eNext.Curr.Y > eNext.Top.Y && ClipperLib.ClipperBase.SlopesEqual3(horzEdge, eNext))
				{
					var op2 = this.AddOutPt(eNext, horzEdge.Bot);
					this.AddJoin(op1, op2, horzEdge.Top);
				}
			}
			else
			{
				horzEdge = this.UpdateEdgeIntoAEL(horzEdge);
			}
		}
		else
		{
			if (horzEdge.OutIdx >= 0)
			{
				this.AddOutPt(horzEdge, horzEdge.Top);
			}
			this.DeleteFromAEL(horzEdge);
		}
	};

	ClipperLib.Clipper.prototype.GetNextInAEL = function (e, Direction)
	{
		return Direction === ClipperLib.Direction.dLeftToRight ? e.NextInAEL : e.PrevInAEL;
	};

	ClipperLib.Clipper.prototype.IsMinima = function (e)
	{
		return e !== null && (e.Prev.NextInLML !== e) && (e.Next.NextInLML !== e);
	};

	ClipperLib.Clipper.prototype.IsMaxima = function (e, Y)
	{
		return (e !== null && e.Top.Y === Y && e.NextInLML === null);
	};

	ClipperLib.Clipper.prototype.IsIntermediate = function (e, Y)
	{
		return (e.Top.Y === Y && e.NextInLML !== null);
	};

	ClipperLib.Clipper.prototype.GetMaximaPair = function (e)
	{
		if ((ClipperLib.FPoint.op_Equality(e.Next.Top, e.Top)) && e.Next.NextInLML === null)
		{
			return e.Next;
		}
		else
		{
			if ((ClipperLib.FPoint.op_Equality(e.Prev.Top, e.Top)) && e.Prev.NextInLML === null)
			{
				return e.Prev;
			}
			else
			{
				return null;
			}
		}
	};

	ClipperLib.Clipper.prototype.GetMaximaPairEx = function (e)
	{
		//as above but returns null if MaxPair isn't in AEL (unless it's horizontal)
		var result = this.GetMaximaPair(e);
		if (result === null || result.OutIdx === ClipperLib.ClipperBase.Skip ||
			((result.NextInAEL === result.PrevInAEL) && !ClipperLib.ClipperBase.IsHorizontal(result)))
		{
			return null;
		}
		return result;
	};

	ClipperLib.Clipper.prototype.ProcessIntersections = function (topY)
	{
		if (this.m_ActiveEdges === null)
			return true;
		try
		{
			this.BuildIntersectList(topY);
			if (this.m_IntersectList.length === 0)
				return true;
			if (this.m_IntersectList.length === 1 || this.FixupIntersectionOrder())
				this.ProcessIntersectList();
			else
				return false;
		}
		catch ($$e2)
		{
			this.m_SortedEdges = null;
			this.m_IntersectList.length = 0;
			ClipperLib.Error("ProcessIntersections error");
		}
		this.m_SortedEdges = null;
		return true;
	};

	ClipperLib.Clipper.prototype.BuildIntersectList = function (topY)
	{
		if (this.m_ActiveEdges === null)
			return;
		//prepare for sorting ...
		var e = this.m_ActiveEdges;
		//console.log(JSON.stringify(JSON.decycle( e )));
		this.m_SortedEdges = e;
		while (e !== null)
		{
			e.PrevInSEL = e.PrevInAEL;
			e.NextInSEL = e.NextInAEL;
			e.Curr.X = ClipperLib.Clipper.TopX(e, topY);
			e = e.NextInAEL;
		}
		//bubblesort ...
		var isModified = true;
		while (isModified && this.m_SortedEdges !== null)
		{
			isModified = false;
			e = this.m_SortedEdges;
			while (e.NextInSEL !== null)
			{
				var eNext = e.NextInSEL;
				var pt = new ClipperLib.FPoint0();
				//console.log("e.Curr.X: " + e.Curr.X + " eNext.Curr.X" + eNext.Curr.X);
				if (e.Curr.X > eNext.Curr.X)
				{
					this.IntersectPoint(e, eNext, pt);
					if (pt.Y < topY)
					{
						pt = new ClipperLib.FPoint2(ClipperLib.Clipper.TopX(e, topY), topY);
					}
					var newNode = new ClipperLib.IntersectNode();
					newNode.Edge1 = e;
					newNode.Edge2 = eNext;
					//newNode.Pt = pt;
					newNode.Pt.X = pt.X;
					newNode.Pt.Y = pt.Y;
					if (ClipperLib.use_xyz) newNode.Pt.Z = pt.Z;
					this.m_IntersectList.push(newNode);
					this.SwapPositionsInSEL(e, eNext);
					isModified = true;
				}
				else
					e = eNext;
			}
			if (e.PrevInSEL !== null)
				e.PrevInSEL.NextInSEL = null;
			else
				break;
		}
		this.m_SortedEdges = null;
	};

	ClipperLib.Clipper.prototype.EdgesAdjacent = function (inode)
	{
		return (inode.Edge1.NextInSEL === inode.Edge2) || (inode.Edge1.PrevInSEL === inode.Edge2);
	};

	ClipperLib.Clipper.IntersectNodeSort = function (node1, node2)
	{
		//the following typecast is safe because the differences in Pt.Y will
		//be limited to the height of the scanbeam.
		return (node2.Pt.Y - node1.Pt.Y);
	};

	ClipperLib.Clipper.prototype.FixupIntersectionOrder = function ()
	{
		//pre-condition: intersections are sorted bottom-most first.
		//Now it's crucial that intersections are made only between adjacent edges,
		//so to ensure this the order of intersections may need adjusting ...
		this.m_IntersectList.sort(this.m_IntersectNodeComparer);
		this.CopyAELToSEL();
		var cnt = this.m_IntersectList.length;
		for (var i = 0; i < cnt; i++)
		{
			if (!this.EdgesAdjacent(this.m_IntersectList[i]))
			{
				var j = i + 1;
				while (j < cnt && !this.EdgesAdjacent(this.m_IntersectList[j]))
					j++;
				if (j === cnt)
					return false;
				var tmp = this.m_IntersectList[i];
				this.m_IntersectList[i] = this.m_IntersectList[j];
				this.m_IntersectList[j] = tmp;
			}
			this.SwapPositionsInSEL(this.m_IntersectList[i].Edge1, this.m_IntersectList[i].Edge2);
		}
		return true;
	};

	ClipperLib.Clipper.prototype.ProcessIntersectList = function ()
	{
		for (var i = 0, ilen = this.m_IntersectList.length; i < ilen; i++)
		{
			var iNode = this.m_IntersectList[i];
			this.IntersectEdges(iNode.Edge1, iNode.Edge2, iNode.Pt);
			this.SwapPositionsInAEL(iNode.Edge1, iNode.Edge2);
		}
		this.m_IntersectList.length = 0;
	};

	ClipperLib.Clipper.TopX = function (edge, currentY)
	{
		//if (edge.Bot == edge.Curr) alert ("edge.Bot = edge.Curr");
		//if (edge.Bot == edge.Top) alert ("edge.Bot = edge.Top");
		if (currentY === edge.Top.Y)
			return edge.Top.X;
		return edge.Bot.X + edge.Dx * (currentY - edge.Bot.Y);
	};

	ClipperLib.Clipper.prototype.IntersectPoint = function (edge1, edge2, ip)
	{
		ip.X = 0;
		ip.Y = 0;
		var b1, b2;
		//nb: with very large coordinate values, it's possible for SlopesEqual() to
		//return false but for the edge.Dx value be equal due to double precision rounding.
		if (edge1.Dx === edge2.Dx)
		{
			ip.Y = edge1.Curr.Y;
			ip.X = ClipperLib.Clipper.TopX(edge1, ip.Y);
			return;
		}
		if (edge1.Delta.X === 0)
		{
			ip.X = edge1.Bot.X;
			if (ClipperLib.ClipperBase.IsHorizontal(edge2))
			{
				ip.Y = edge2.Bot.Y;
			}
			else
			{
				b2 = edge2.Bot.Y - (edge2.Bot.X / edge2.Dx);
				ip.Y = ip.X / edge2.Dx + b2;
			}
		}
		else if (edge2.Delta.X === 0)
		{
			ip.X = edge2.Bot.X;
			if (ClipperLib.ClipperBase.IsHorizontal(edge1))
			{
				ip.Y = edge1.Bot.Y;
			}
			else
			{
				b1 = edge1.Bot.Y - (edge1.Bot.X / edge1.Dx);
				ip.Y = ip.X / edge1.Dx + b1;
			}
		}
		else
		{
			b1 = edge1.Bot.X - edge1.Bot.Y * edge1.Dx;
			b2 = edge2.Bot.X - edge2.Bot.Y * edge2.Dx;
			var q = (b2 - b1) / (edge1.Dx - edge2.Dx);
			ip.Y = q;
			if (Math.abs(edge1.Dx) < Math.abs(edge2.Dx))
				ip.X = edge1.Dx * q + b1;
			else
				ip.X = edge2.Dx * q + b2;
		}
		if (ip.Y < edge1.Top.Y || ip.Y < edge2.Top.Y)
		{
			if (edge1.Top.Y > edge2.Top.Y)
			{
				ip.Y = edge1.Top.Y;
				ip.X = ClipperLib.Clipper.TopX(edge2, edge1.Top.Y);
				return ip.X < edge1.Top.X;
			}
			else
				ip.Y = edge2.Top.Y;
			if (Math.abs(edge1.Dx) < Math.abs(edge2.Dx))
				ip.X = ClipperLib.Clipper.TopX(edge1, ip.Y);
			else
				ip.X = ClipperLib.Clipper.TopX(edge2, ip.Y);
		}
		//finally, don't allow 'ip' to be BELOW curr.Y (ie bottom of scanbeam) ...
		if (ip.Y > edge1.Curr.Y)
		{
			ip.Y = edge1.Curr.Y;
			//better to use the more vertical edge to derive X ...
			if (Math.abs(edge1.Dx) > Math.abs(edge2.Dx))
				ip.X = ClipperLib.Clipper.TopX(edge2, ip.Y);
			else
				ip.X = ClipperLib.Clipper.TopX(edge1, ip.Y);
		}
	};

	ClipperLib.Clipper.prototype.ProcessEdgesAtTopOfScanbeam = function (topY)
	{
		var e = this.m_ActiveEdges;

		while (e !== null)
		{
			//1. process maxima, treating them as if they're 'bent' horizontal edges,
			//   but exclude maxima with horizontal edges. nb: e can't be a horizontal.
			var IsMaximaEdge = this.IsMaxima(e, topY);
			if (IsMaximaEdge)
			{
				var eMaxPair = this.GetMaximaPairEx(e);
				IsMaximaEdge = (eMaxPair === null || !ClipperLib.ClipperBase.IsHorizontal(eMaxPair));
			}
			if (IsMaximaEdge)
			{
				if (this.StrictlySimple)
				{
					this.InsertMaxima(e.Top.X);
				}
				var ePrev = e.PrevInAEL;
				this.DoMaxima(e);
				if (ePrev === null)
					e = this.m_ActiveEdges;
				else
					e = ePrev.NextInAEL;
			}
			else
			{
				//2. promote horizontal edges, otherwise update Curr.X and Curr.Y ...
				if (this.IsIntermediate(e, topY) && ClipperLib.ClipperBase.IsHorizontal(e.NextInLML))
				{
					e = this.UpdateEdgeIntoAEL(e);
					if (e.OutIdx >= 0)
						this.AddOutPt(e, e.Bot);
					this.AddEdgeToSEL(e);
				}
				else
				{
					e.Curr.X = ClipperLib.Clipper.TopX(e, topY);
					e.Curr.Y = topY;
				}

				if (ClipperLib.use_xyz)
				{
					if (e.Top.Y === topY) e.Curr.Z = e.Top.Z;
					else if (e.Bot.Y === topY) e.Curr.Z = e.Bot.Z;
					else e.Curr.Z = 0;
				}

				//When StrictlySimple and 'e' is being touched by another edge, then
				//make sure both edges have a vertex here ...
				if (this.StrictlySimple)
				{
					var ePrev = e.PrevInAEL;
					if ((e.OutIdx >= 0) && (e.WindDelta !== 0) && ePrev !== null &&
						(ePrev.OutIdx >= 0) && (ePrev.Curr.X === e.Curr.X) &&
						(ePrev.WindDelta !== 0))
					{
						var ip = new ClipperLib.FPoint1(e.Curr);

						if (ClipperLib.use_xyz)
						{
							this.SetZ(ip, ePrev, e);
						}

						var op = this.AddOutPt(ePrev, ip);
						var op2 = this.AddOutPt(e, ip);
						this.AddJoin(op, op2, ip); //StrictlySimple (type-3) join
					}
				}
				e = e.NextInAEL;
			}
		}
		//3. Process horizontals at the Top of the scanbeam ...
		this.ProcessHorizontals();
		this.m_Maxima = null;
		//4. Promote intermediate vertices ...
		e = this.m_ActiveEdges;
		while (e !== null)
		{
			if (this.IsIntermediate(e, topY))
			{
				var op = null;
				if (e.OutIdx >= 0)
					op = this.AddOutPt(e, e.Top);
				e = this.UpdateEdgeIntoAEL(e);
				//if output polygons share an edge, they'll need joining later ...
				var ePrev = e.PrevInAEL;
				var eNext = e.NextInAEL;

				if (ePrev !== null && ePrev.Curr.X === e.Bot.X && ePrev.Curr.Y === e.Bot.Y && op !== null && ePrev.OutIdx >= 0 && ePrev.Curr.Y === ePrev.Top.Y && ClipperLib.ClipperBase.SlopesEqual5(e.Curr, e.Top, ePrev.Curr, ePrev.Top) && (e.WindDelta !== 0) && (ePrev.WindDelta !== 0))
				{
					var op2 = this.AddOutPt(ePrev2, e.Bot);
					this.AddJoin(op, op2, e.Top);
				}
				else if (eNext !== null && eNext.Curr.X === e.Bot.X && eNext.Curr.Y === e.Bot.Y && op !== null && eNext.OutIdx >= 0 && eNext.Curr.Y === eNext.Top.Y && ClipperLib.ClipperBase.SlopesEqual5(e.Curr, e.Top, eNext.Curr, eNext.Top) && (e.WindDelta !== 0) && (eNext.WindDelta !== 0))
				{
					var op2 = this.AddOutPt(eNext, e.Bot);
					this.AddJoin(op, op2, e.Top);
				}
			}
			e = e.NextInAEL;
		}
	};

	ClipperLib.Clipper.prototype.DoMaxima = function (e)
	{
		var eMaxPair = this.GetMaximaPairEx(e);
		if (eMaxPair === null)
		{
			if (e.OutIdx >= 0)
				this.AddOutPt(e, e.Top);
			this.DeleteFromAEL(e);
			return;
		}
		var eNext = e.NextInAEL;
		while (eNext !== null && eNext !== eMaxPair)
		{
			this.IntersectEdges(e, eNext, e.Top);
			this.SwapPositionsInAEL(e, eNext);
			eNext = e.NextInAEL;
		}
		if (e.OutIdx === -1 && eMaxPair.OutIdx === -1)
		{
			this.DeleteFromAEL(e);
			this.DeleteFromAEL(eMaxPair);
		}
		else if (e.OutIdx >= 0 && eMaxPair.OutIdx >= 0)
		{
			if (e.OutIdx >= 0) this.AddLocalMaxPoly(e, eMaxPair, e.Top);
			this.DeleteFromAEL(e);
			this.DeleteFromAEL(eMaxPair);
		}
		else if (ClipperLib.use_lines && e.WindDelta === 0)
		{
			if (e.OutIdx >= 0)
			{
				this.AddOutPt(e, e.Top);
				e.OutIdx = ClipperLib.ClipperBase.Unassigned;
			}
			this.DeleteFromAEL(e);
			if (eMaxPair.OutIdx >= 0)
			{
				this.AddOutPt(eMaxPair, e.Top);
				eMaxPair.OutIdx = ClipperLib.ClipperBase.Unassigned;
			}
			this.DeleteFromAEL(eMaxPair);
		}
		else
			ClipperLib.Error("DoMaxima error");
	};

	ClipperLib.Clipper.ReversePaths = function (polys)
	{
		for (var i = 0, len = polys.length; i < len; i++)
			polys[i].reverse();
	};

	ClipperLib.Clipper.Orientation = function (poly)
	{
		return ClipperLib.Clipper.Area(poly) >= 0;
	};

	ClipperLib.Clipper.prototype.PointCount = function (pts)
	{
		if (pts === null)
			return 0;
		var result = 0;
		var p = pts;
		do {
			result++;
			p = p.Next;
		}
		while (p !== pts)
		return result;
	};

	ClipperLib.Clipper.prototype.BuildResult = function (polyg)
	{
		ClipperLib.Clear(polyg);
		for (var i = 0, ilen = this.m_PolyOuts.length; i < ilen; i++)
		{
			var outRec = this.m_PolyOuts[i];
			if (outRec.Pts === null)
				continue;
			var p = outRec.Pts.Prev;
			var cnt = this.PointCount(p);
			if (cnt < 2)
				continue;
			var pg = new Array(cnt);
			for (var j = 0; j < cnt; j++)
			{
				pg[j] = p.Pt;
				p = p.Prev;
			}
			polyg.push(pg);
		}
	};

	ClipperLib.Clipper.prototype.BuildResult2 = function (polytree)
	{
		polytree.Clear();
		//add each output polygon/contour to polytree ...
		//polytree.m_AllPolys.set_Capacity(this.m_PolyOuts.length);
		for (var i = 0, ilen = this.m_PolyOuts.length; i < ilen; i++)
		{
			var outRec = this.m_PolyOuts[i];
			var cnt = this.PointCount(outRec.Pts);
			if ((outRec.IsOpen && cnt < 2) || (!outRec.IsOpen && cnt < 3))
				continue;
			this.FixHoleLinkage(outRec);
			var pn = new ClipperLib.PolyNode();
			polytree.m_AllPolys.push(pn);
			outRec.PolyNode = pn;
			pn.m_polygon.length = cnt;
			var op = outRec.Pts.Prev;
			for (var j = 0; j < cnt; j++)
			{
				pn.m_polygon[j] = op.Pt;
				op = op.Prev;
			}
		}
		//fixup PolyNode links etc ...
		//polytree.m_Childs.set_Capacity(this.m_PolyOuts.length);
		for (var i = 0, ilen = this.m_PolyOuts.length; i < ilen; i++)
		{
			var outRec = this.m_PolyOuts[i];
			if (outRec.PolyNode === null)
				continue;
			else if (outRec.IsOpen)
			{
				outRec.PolyNode.IsOpen = true;
				polytree.AddChild(outRec.PolyNode);
			}
			else if (outRec.FirstLeft !== null && outRec.FirstLeft.PolyNode !== null)
				outRec.FirstLeft.PolyNode.AddChild(outRec.PolyNode);
			else
				polytree.AddChild(outRec.PolyNode);
		}
	};

	ClipperLib.Clipper.prototype.FixupOutPolyline = function (outRec)
	{
		var pp = outRec.Pts;
		var lastPP = pp.Prev;
		while (pp !== lastPP)
		{
			pp = pp.Next;
			if (ClipperLib.FPoint.op_Equality(pp.Pt, pp.Prev.Pt))
			{
				if (pp === lastPP)
				{
					lastPP = pp.Prev;
				}
				var tmpPP = pp.Prev;
				tmpPP.Next = pp.Next;
				pp.Next.Prev = tmpPP;
				pp = tmpPP;
			}
		}
		if (pp === pp.Prev)
		{
			outRec.Pts = null;
		}
	};

	ClipperLib.Clipper.prototype.FixupOutPolygon = function (outRec)
	{
		//FixupOutPolygon() - removes duplicate points and simplifies consecutive
		//parallel edges by removing the middle vertex.
		var lastOK = null;
		outRec.BottomPt = null;
		var pp = outRec.Pts;
		var preserveCol = this.PreserveCollinear || this.StrictlySimple;
		for (;;)
		{
			if (pp.Prev === pp || pp.Prev === pp.Next)
			{
				outRec.Pts = null;
				return;
			}

			//test for duplicate points and collinear edges ...
			if ((ClipperLib.FPoint.op_Equality(pp.Pt, pp.Next.Pt)) || (ClipperLib.FPoint.op_Equality(pp.Pt, pp.Prev.Pt)) || (ClipperLib.ClipperBase.SlopesEqual4(pp.Prev.Pt, pp.Pt, pp.Next.Pt) && (!preserveCol || !this.Pt2IsBetweenPt1AndPt3(pp.Prev.Pt, pp.Pt, pp.Next.Pt))))
			{
				lastOK = null;
				pp.Prev.Next = pp.Next;
				pp.Next.Prev = pp.Prev;
				pp = pp.Prev;
			}
			else if (pp === lastOK)
				break;
			else
			{
				if (lastOK === null)
					lastOK = pp;
				pp = pp.Next;
			}
		}
		outRec.Pts = pp;
	};

	ClipperLib.Clipper.prototype.DupOutPt = function (outPt, InsertAfter)
	{
		var result = new ClipperLib.OutPt();
		//result.Pt = outPt.Pt;
		result.Pt.X = outPt.Pt.X;
		result.Pt.Y = outPt.Pt.Y;
		if (ClipperLib.use_xyz) result.Pt.Z = outPt.Pt.Z;
		result.Idx = outPt.Idx;
		if (InsertAfter)
		{
			result.Next = outPt.Next;
			result.Prev = outPt;
			outPt.Next.Prev = result;
			outPt.Next = result;
		}
		else
		{
			result.Prev = outPt.Prev;
			result.Next = outPt;
			outPt.Prev.Next = result;
			outPt.Prev = result;
		}
		return result;
	};

	ClipperLib.Clipper.prototype.GetOverlap = function (a1, a2, b1, b2, $val)
	{
		if (a1 < a2)
		{
			if (b1 < b2)
			{
				$val.Left = Math.max(a1, b1);
				$val.Right = Math.min(a2, b2);
			}
			else
			{
				$val.Left = Math.max(a1, b2);
				$val.Right = Math.min(a2, b1);
			}
		}
		else
		{
			if (b1 < b2)
			{
				$val.Left = Math.max(a2, b1);
				$val.Right = Math.min(a1, b2);
			}
			else
			{
				$val.Left = Math.max(a2, b2);
				$val.Right = Math.min(a1, b1);
			}
		}
		return $val.Left < $val.Right;
	};

	ClipperLib.Clipper.prototype.JoinHorz = function (op1, op1b, op2, op2b, Pt, DiscardLeft)
	{
		var Dir1 = (op1.Pt.X > op1b.Pt.X ? ClipperLib.Direction.dRightToLeft : ClipperLib.Direction.dLeftToRight);
		var Dir2 = (op2.Pt.X > op2b.Pt.X ? ClipperLib.Direction.dRightToLeft : ClipperLib.Direction.dLeftToRight);
		if (Dir1 === Dir2)
			return false;
		//When DiscardLeft, we want Op1b to be on the Left of Op1, otherwise we
		//want Op1b to be on the Right. (And likewise with Op2 and Op2b.)
		//So, to facilitate this while inserting Op1b and Op2b ...
		//when DiscardLeft, make sure we're AT or RIGHT of Pt before adding Op1b,
		//otherwise make sure we're AT or LEFT of Pt. (Likewise with Op2b.)
		if (Dir1 === ClipperLib.Direction.dLeftToRight)
		{
			while (op1.Next.Pt.X <= Pt.X &&
				op1.Next.Pt.X >= op1.Pt.X && op1.Next.Pt.Y === Pt.Y)
				op1 = op1.Next;
			if (DiscardLeft && (op1.Pt.X !== Pt.X))
				op1 = op1.Next;
			op1b = this.DupOutPt(op1, !DiscardLeft);
			if (ClipperLib.FPoint.op_Inequality(op1b.Pt, Pt))
			{
				op1 = op1b;
				//op1.Pt = Pt;
				op1.Pt.X = Pt.X;
				op1.Pt.Y = Pt.Y;
				if (ClipperLib.use_xyz) op1.Pt.Z = Pt.Z;
				op1b = this.DupOutPt(op1, !DiscardLeft);
			}
		}
		else
		{
			while (op1.Next.Pt.X >= Pt.X &&
				op1.Next.Pt.X <= op1.Pt.X && op1.Next.Pt.Y === Pt.Y)
				op1 = op1.Next;
			if (!DiscardLeft && (op1.Pt.X !== Pt.X))
				op1 = op1.Next;
			op1b = this.DupOutPt(op1, DiscardLeft);
			if (ClipperLib.FPoint.op_Inequality(op1b.Pt, Pt))
			{
				op1 = op1b;
				//op1.Pt = Pt;
				op1.Pt.X = Pt.X;
				op1.Pt.Y = Pt.Y;
				if (ClipperLib.use_xyz) op1.Pt.Z = Pt.Z;
				op1b = this.DupOutPt(op1, DiscardLeft);
			}
		}
		if (Dir2 === ClipperLib.Direction.dLeftToRight)
		{
			while (op2.Next.Pt.X <= Pt.X &&
				op2.Next.Pt.X >= op2.Pt.X && op2.Next.Pt.Y === Pt.Y)
				op2 = op2.Next;
			if (DiscardLeft && (op2.Pt.X !== Pt.X))
				op2 = op2.Next;
			op2b = this.DupOutPt(op2, !DiscardLeft);
			if (ClipperLib.FPoint.op_Inequality(op2b.Pt, Pt))
			{
				op2 = op2b;
				//op2.Pt = Pt;
				op2.Pt.X = Pt.X;
				op2.Pt.Y = Pt.Y;
				if (ClipperLib.use_xyz) op2.Pt.Z = Pt.Z;
				op2b = this.DupOutPt(op2, !DiscardLeft);
			}
		}
		else
		{
			while (op2.Next.Pt.X >= Pt.X &&
				op2.Next.Pt.X <= op2.Pt.X && op2.Next.Pt.Y === Pt.Y)
				op2 = op2.Next;
			if (!DiscardLeft && (op2.Pt.X !== Pt.X))
				op2 = op2.Next;
			op2b = this.DupOutPt(op2, DiscardLeft);
			if (ClipperLib.FPoint.op_Inequality(op2b.Pt, Pt))
			{
				op2 = op2b;
				//op2.Pt = Pt;
				op2.Pt.X = Pt.X;
				op2.Pt.Y = Pt.Y;
				if (ClipperLib.use_xyz) op2.Pt.Z = Pt.Z;
				op2b = this.DupOutPt(op2, DiscardLeft);
			}
		}
		if ((Dir1 === ClipperLib.Direction.dLeftToRight) === DiscardLeft)
		{
			op1.Prev = op2;
			op2.Next = op1;
			op1b.Next = op2b;
			op2b.Prev = op1b;
		}
		else
		{
			op1.Next = op2;
			op2.Prev = op1;
			op1b.Prev = op2b;
			op2b.Next = op1b;
		}
		return true;
	};

	ClipperLib.Clipper.prototype.JoinPoints = function (j, outRec1, outRec2)
	{
		var op1 = j.OutPt1,
			op1b = new ClipperLib.OutPt();
		var op2 = j.OutPt2,
			op2b = new ClipperLib.OutPt();
		//There are 3 kinds of joins for output polygons ...
		//1. Horizontal joins where Join.OutPt1 & Join.OutPt2 are vertices anywhere
		//along (horizontal) collinear edges (& Join.OffPt is on the same horizontal).
		//2. Non-horizontal joins where Join.OutPt1 & Join.OutPt2 are at the same
		//location at the Bottom of the overlapping segment (& Join.OffPt is above).
		//3. StrictlySimple joins where edges touch but are not collinear and where
		//Join.OutPt1, Join.OutPt2 & Join.OffPt all share the same point.
		var isHorizontal = (j.OutPt1.Pt.Y === j.OffPt.Y);
		if (isHorizontal && (ClipperLib.FPoint.op_Equality(j.OffPt, j.OutPt1.Pt)) && (ClipperLib.FPoint.op_Equality(j.OffPt, j.OutPt2.Pt)))
		{
			//Strictly Simple join ...
			if (outRec1 !== outRec2) return false;

			op1b = j.OutPt1.Next;
			while (op1b !== op1 && (ClipperLib.FPoint.op_Equality(op1b.Pt, j.OffPt)))
				op1b = op1b.Next;
			var reverse1 = (op1b.Pt.Y > j.OffPt.Y);
			op2b = j.OutPt2.Next;
			while (op2b !== op2 && (ClipperLib.FPoint.op_Equality(op2b.Pt, j.OffPt)))
				op2b = op2b.Next;
			var reverse2 = (op2b.Pt.Y > j.OffPt.Y);
			if (reverse1 === reverse2)
				return false;
			if (reverse1)
			{
				op1b = this.DupOutPt(op1, false);
				op2b = this.DupOutPt(op2, true);
				op1.Prev = op2;
				op2.Next = op1;
				op1b.Next = op2b;
				op2b.Prev = op1b;
				j.OutPt1 = op1;
				j.OutPt2 = op1b;
				return true;
			}
			else
			{
				op1b = this.DupOutPt(op1, true);
				op2b = this.DupOutPt(op2, false);
				op1.Next = op2;
				op2.Prev = op1;
				op1b.Prev = op2b;
				op2b.Next = op1b;
				j.OutPt1 = op1;
				j.OutPt2 = op1b;
				return true;
			}
		}
		else if (isHorizontal)
		{
			//treat horizontal joins differently to non-horizontal joins since with
			//them we're not yet sure where the overlapping is. OutPt1.Pt & OutPt2.Pt
			//may be anywhere along the horizontal edge.
			op1b = op1;
			while (op1.Prev.Pt.Y === op1.Pt.Y && op1.Prev !== op1b && op1.Prev !== op2)
				op1 = op1.Prev;
			while (op1b.Next.Pt.Y === op1b.Pt.Y && op1b.Next !== op1 && op1b.Next !== op2)
				op1b = op1b.Next;
			if (op1b.Next === op1 || op1b.Next === op2)
				return false;
			//a flat 'polygon'
			op2b = op2;
			while (op2.Prev.Pt.Y === op2.Pt.Y && op2.Prev !== op2b && op2.Prev !== op1b)
				op2 = op2.Prev;
			while (op2b.Next.Pt.Y === op2b.Pt.Y && op2b.Next !== op2 && op2b.Next !== op1)
				op2b = op2b.Next;
			if (op2b.Next === op2 || op2b.Next === op1)
				return false;
			//a flat 'polygon'
			//Op1 -. Op1b & Op2 -. Op2b are the extremites of the horizontal edges

			var $val = {
				Left: null,
				Right: null
			};

			if (!this.GetOverlap(op1.Pt.X, op1b.Pt.X, op2.Pt.X, op2b.Pt.X, $val))
				return false;
			var Left = $val.Left;
			var Right = $val.Right;

			//DiscardLeftSide: when overlapping edges are joined, a spike will created
			//which needs to be cleaned up. However, we don't want Op1 or Op2 caught up
			//on the discard Side as either may still be needed for other joins ...
			var Pt = new ClipperLib.FPoint0();
			var DiscardLeftSide;
			if (op1.Pt.X >= Left && op1.Pt.X <= Right)
			{
				//Pt = op1.Pt;
				Pt.X = op1.Pt.X;
				Pt.Y = op1.Pt.Y;
				if (ClipperLib.use_xyz) Pt.Z = op1.Pt.Z;
				DiscardLeftSide = (op1.Pt.X > op1b.Pt.X);
			}
			else if (op2.Pt.X >= Left && op2.Pt.X <= Right)
			{
				//Pt = op2.Pt;
				Pt.X = op2.Pt.X;
				Pt.Y = op2.Pt.Y;
				if (ClipperLib.use_xyz) Pt.Z = op2.Pt.Z;
				DiscardLeftSide = (op2.Pt.X > op2b.Pt.X);
			}
			else if (op1b.Pt.X >= Left && op1b.Pt.X <= Right)
			{
				//Pt = op1b.Pt;
				Pt.X = op1b.Pt.X;
				Pt.Y = op1b.Pt.Y;
				if (ClipperLib.use_xyz) Pt.Z = op1b.Pt.Z;
				DiscardLeftSide = op1b.Pt.X > op1.Pt.X;
			}
			else
			{
				//Pt = op2b.Pt;
				Pt.X = op2b.Pt.X;
				Pt.Y = op2b.Pt.Y;
				if (ClipperLib.use_xyz) Pt.Z = op2b.Pt.Z;
				DiscardLeftSide = (op2b.Pt.X > op2.Pt.X);
			}
			j.OutPt1 = op1;
			j.OutPt2 = op2;
			return this.JoinHorz(op1, op1b, op2, op2b, Pt, DiscardLeftSide);
		}
		else
		{
			//nb: For non-horizontal joins ...
			//    1. Jr.OutPt1.Pt.Y == Jr.OutPt2.Pt.Y
			//    2. Jr.OutPt1.Pt > Jr.OffPt.Y
			//make sure the polygons are correctly oriented ...
			op1b = op1.Next;
			while ((ClipperLib.FPoint.op_Equality(op1b.Pt, op1.Pt)) && (op1b !== op1))
				op1b = op1b.Next;
			var Reverse1 = ((op1b.Pt.Y > op1.Pt.Y) || !ClipperLib.ClipperBase.SlopesEqual4(op1.Pt, op1b.Pt, j.OffPt));
			if (Reverse1)
			{
				op1b = op1.Prev;
				while ((ClipperLib.FPoint.op_Equality(op1b.Pt, op1.Pt)) && (op1b !== op1))
					op1b = op1b.Prev;

				if ((op1b.Pt.Y > op1.Pt.Y) || !ClipperLib.ClipperBase.SlopesEqual4(op1.Pt, op1b.Pt, j.OffPt))
					return false;
			}
			op2b = op2.Next;
			while ((ClipperLib.FPoint.op_Equality(op2b.Pt, op2.Pt)) && (op2b !== op2))
				op2b = op2b.Next;

			var Reverse2 = ((op2b.Pt.Y > op2.Pt.Y) || !ClipperLib.ClipperBase.SlopesEqual4(op2.Pt, op2b.Pt, j.OffPt));
			if (Reverse2)
			{
				op2b = op2.Prev;
				while ((ClipperLib.FPoint.op_Equality(op2b.Pt, op2.Pt)) && (op2b !== op2))
					op2b = op2b.Prev;

				if ((op2b.Pt.Y > op2.Pt.Y) || !ClipperLib.ClipperBase.SlopesEqual4(op2.Pt, op2b.Pt, j.OffPt))
					return false;
			}
			if ((op1b === op1) || (op2b === op2) || (op1b === op2b) ||
				((outRec1 === outRec2) && (Reverse1 === Reverse2)))
				return false;
			if (Reverse1)
			{
				op1b = this.DupOutPt(op1, false);
				op2b = this.DupOutPt(op2, true);
				op1.Prev = op2;
				op2.Next = op1;
				op1b.Next = op2b;
				op2b.Prev = op1b;
				j.OutPt1 = op1;
				j.OutPt2 = op1b;
				return true;
			}
			else
			{
				op1b = this.DupOutPt(op1, true);
				op2b = this.DupOutPt(op2, false);
				op1.Next = op2;
				op2.Prev = op1;
				op1b.Prev = op2b;
				op2b.Next = op1b;
				j.OutPt1 = op1;
				j.OutPt2 = op1b;
				return true;
			}
		}
	};

	ClipperLib.Clipper.GetBounds = function (paths)
	{
		var i = 0,
			cnt = paths.length;
		while (i < cnt && paths[i].length === 0) i++;
		if (i === cnt) return new ClipperLib.FRect(0, 0, 0, 0);
		var result = new ClipperLib.FRect();
		result.left = paths[i][0].X;
		result.right = result.left;
		result.top = paths[i][0].Y;
		result.bottom = result.top;
		for (; i < cnt; i++)
			for (var j = 0, jlen = paths[i].length; j < jlen; j++)
			{
				if (paths[i][j].X < result.left) result.left = paths[i][j].X;
				else if (paths[i][j].X > result.right) result.right = paths[i][j].X;
				if (paths[i][j].Y < result.top) result.top = paths[i][j].Y;
				else if (paths[i][j].Y > result.bottom) result.bottom = paths[i][j].Y;
			}
		return result;
	}
	ClipperLib.Clipper.prototype.GetBounds2 = function (ops)
	{
		var opStart = ops;
		var result = new ClipperLib.FRect();
		result.left = ops.Pt.X;
		result.right = ops.Pt.X;
		result.top = ops.Pt.Y;
		result.bottom = ops.Pt.Y;
		ops = ops.Next;
		while (ops !== opStart)
		{
			if (ops.Pt.X < result.left)
				result.left = ops.Pt.X;
			if (ops.Pt.X > result.right)
				result.right = ops.Pt.X;
			if (ops.Pt.Y < result.top)
				result.top = ops.Pt.Y;
			if (ops.Pt.Y > result.bottom)
				result.bottom = ops.Pt.Y;
			ops = ops.Next;
		}
		return result;
	};

	ClipperLib.Clipper.PointInPolygon = function (pt, path)
	{
		//returns 0 if false, +1 if true, -1 if pt ON polygon boundary
		//See "The Point in Polygon Problem for Arbitrary Polygons" by Hormann & Agathos
		//http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.88.5498&rep=rep1&type=pdf
		var result = 0,
			cnt = path.length;
		if (cnt < 3)
			return 0;
		var ip = path[0];
		for (var i = 1; i <= cnt; ++i)
		{
			var ipNext = (i === cnt ? path[0] : path[i]);
			if (ipNext.Y === pt.Y)
			{
				if ((ipNext.X === pt.X) || (ip.Y === pt.Y && ((ipNext.X > pt.X) === (ip.X < pt.X))))
					return -1;
			}
			if ((ip.Y < pt.Y) !== (ipNext.Y < pt.Y))
			{
				if (ip.X >= pt.X)
				{
					if (ipNext.X > pt.X)
						result = 1 - result;
					else
					{
						var d = (ip.X - pt.X) * (ipNext.Y - pt.Y) - (ipNext.X - pt.X) * (ip.Y - pt.Y);
						if (d === 0)
							return -1;
						else if ((d > 0) === (ipNext.Y > ip.Y))
							result = 1 - result;
					}
				}
				else
				{
					if (ipNext.X > pt.X)
					{
						var d = (ip.X - pt.X) * (ipNext.Y - pt.Y) - (ipNext.X - pt.X) * (ip.Y - pt.Y);
						if (d === 0)
							return -1;
						else if ((d > 0) === (ipNext.Y > ip.Y))
							result = 1 - result;
					}
				}
			}
			ip = ipNext;
		}
		return result;
	};

	ClipperLib.Clipper.prototype.PointInPolygon = function (pt, op)
	{
		//returns 0 if false, +1 if true, -1 if pt ON polygon boundary
		var result = 0;
		var startOp = op;
		var ptx = pt.X,
			pty = pt.Y;
		var poly0x = op.Pt.X,
			poly0y = op.Pt.Y;
		do {
			op = op.Next;
			var poly1x = op.Pt.X,
				poly1y = op.Pt.Y;
			if (poly1y === pty)
			{
				if ((poly1x === ptx) || (poly0y === pty && ((poly1x > ptx) === (poly0x < ptx))))
					return -1;
			}
			if ((poly0y < pty) !== (poly1y < pty))
			{
				if (poly0x >= ptx)
				{
					if (poly1x > ptx)
						result = 1 - result;
					else
					{
						var d = (poly0x - ptx) * (poly1y - pty) - (poly1x - ptx) * (poly0y - pty);
						if (d === 0)
							return -1;
						if ((d > 0) === (poly1y > poly0y))
							result = 1 - result;
					}
				}
				else
				{
					if (poly1x > ptx)
					{
						var d = (poly0x - ptx) * (poly1y - pty) - (poly1x - ptx) * (poly0y - pty);
						if (d === 0)
							return -1;
						if ((d > 0) === (poly1y > poly0y))
							result = 1 - result;
					}
				}
			}
			poly0x = poly1x;
			poly0y = poly1y;
		} while (startOp !== op);

		return result;
	};

	ClipperLib.Clipper.prototype.Poly2ContainsPoly1 = function (outPt1, outPt2)
	{
		var op = outPt1;
		do {
			//nb: PointInPolygon returns 0 if false, +1 if true, -1 if pt on polygon
			var res = this.PointInPolygon(op.Pt, outPt2);
			if (res >= 0)
				return res > 0;
			op = op.Next;
		}
		while (op !== outPt1)
		return true;
	};

	ClipperLib.Clipper.prototype.FixupFirstLefts1 = function (OldOutRec, NewOutRec)
	{
		var outRec, firstLeft;
		for (var i = 0, ilen = this.m_PolyOuts.length; i < ilen; i++)
		{
			outRec = this.m_PolyOuts[i];
			firstLeft = ClipperLib.Clipper.ParseFirstLeft(outRec.FirstLeft);
			if (outRec.Pts !== null && firstLeft === OldOutRec)
			{
				if (this.Poly2ContainsPoly1(outRec.Pts, NewOutRec.Pts))
					outRec.FirstLeft = NewOutRec;
			}
		}
	}

	ClipperLib.Clipper.prototype.FixupFirstLefts2 = function (innerOutRec, outerOutRec)
	{
		//A polygon has split into two such that one is now the inner of the other.
		//It's possible that these polygons now wrap around other polygons, so check
		//every polygon that's also contained by OuterOutRec's FirstLeft container
		//(including nil) to see if they've become inner to the new inner polygon ...
		var orfl = outerOutRec.FirstLeft;
		var outRec, firstLeft;
		for (var i = 0, ilen = this.m_PolyOuts.length; i < ilen; i++)
		{
			outRec = this.m_PolyOuts[i];
			if (outRec.Pts === null || outRec === outerOutRec || outRec === innerOutRec)
				continue;
			firstLeft = ClipperLib.Clipper.ParseFirstLeft(outRec.FirstLeft);
			if (firstLeft !== orfl && firstLeft !== innerOutRec && firstLeft !== outerOutRec)
				continue;
			if (this.Poly2ContainsPoly1(outRec.Pts, innerOutRec.Pts))
				outRec.FirstLeft = innerOutRec;
			else if (this.Poly2ContainsPoly1(outRec.Pts, outerOutRec.Pts))
				outRec.FirstLeft = outerOutRec;
			else if (outRec.FirstLeft === innerOutRec || outRec.FirstLeft === outerOutRec)
				outRec.FirstLeft = orfl;
		}
	}

	ClipperLib.Clipper.prototype.FixupFirstLefts3 = function (OldOutRec, NewOutRec)
	{
		//same as FixupFirstLefts1 but doesn't call Poly2ContainsPoly1()
		var outRec;
		var firstLeft;
		for (var i = 0, ilen = this.m_PolyOuts.length; i < ilen; i++)
		{
			outRec = this.m_PolyOuts[i];
			firstLeft = ClipperLib.Clipper.ParseFirstLeft(outRec.FirstLeft);
			if (outRec.Pts !== null && firstLeft === OldOutRec)
				outRec.FirstLeft = NewOutRec;
		}
	}

	ClipperLib.Clipper.ParseFirstLeft = function (FirstLeft)
	{
		while (FirstLeft !== null && FirstLeft.Pts === null)
			FirstLeft = FirstLeft.FirstLeft;
		return FirstLeft;
	};

	ClipperLib.Clipper.prototype.JoinCommonEdges = function ()
	{
		for (var i = 0, ilen = this.m_Joins.length; i < ilen; i++)
		{
			var join = this.m_Joins[i];
			var outRec1 = this.GetOutRec(join.OutPt1.Idx);
			var outRec2 = this.GetOutRec(join.OutPt2.Idx);
			if (outRec1.Pts === null || outRec2.Pts === null)
				continue;

			if (outRec1.IsOpen || outRec2.IsOpen)
			{
				continue;
			}

			//get the polygon fragment with the correct hole state (FirstLeft)
			//before calling JoinPoints() ...
			var holeStateRec;
			if (outRec1 === outRec2)
				holeStateRec = outRec1;
			else if (this.OutRec1RightOfOutRec2(outRec1, outRec2))
				holeStateRec = outRec2;
			else if (this.OutRec1RightOfOutRec2(outRec2, outRec1))
				holeStateRec = outRec1;
			else
				holeStateRec = this.GetLowermostRec(outRec1, outRec2);

			if (!this.JoinPoints(join, outRec1, outRec2)) continue;

			if (outRec1 === outRec2)
			{
				//instead of joining two polygons, we've just created a new one by
				//splitting one polygon into two.
				outRec1.Pts = join.OutPt1;
				outRec1.BottomPt = null;
				outRec2 = this.CreateOutRec();
				outRec2.Pts = join.OutPt2;
				//update all OutRec2.Pts Idx's ...
				this.UpdateOutPtIdxs(outRec2);

				if (this.Poly2ContainsPoly1(outRec2.Pts, outRec1.Pts))
				{
					//outRec1 contains outRec2 ...
					outRec2.IsHole = !outRec1.IsHole;
					outRec2.FirstLeft = outRec1;
					if (this.m_UsingPolyTree)
						this.FixupFirstLefts2(outRec2, outRec1);
					if ((outRec2.IsHole ^ this.ReverseSolution) == (this.Area$1(outRec2) > 0))
						this.ReversePolyPtLinks(outRec2.Pts);
				}
				else if (this.Poly2ContainsPoly1(outRec1.Pts, outRec2.Pts))
				{
					//outRec2 contains outRec1 ...
					outRec2.IsHole = outRec1.IsHole;
					outRec1.IsHole = !outRec2.IsHole;
					outRec2.FirstLeft = outRec1.FirstLeft;
					outRec1.FirstLeft = outRec2;
					if (this.m_UsingPolyTree)
						this.FixupFirstLefts2(outRec1, outRec2);

					if ((outRec1.IsHole ^ this.ReverseSolution) == (this.Area$1(outRec1) > 0))
						this.ReversePolyPtLinks(outRec1.Pts);
				}
				else
				{
					//the 2 polygons are completely separate ...
					outRec2.IsHole = outRec1.IsHole;
					outRec2.FirstLeft = outRec1.FirstLeft;
					//fixup FirstLeft pointers that may need reassigning to OutRec2
					if (this.m_UsingPolyTree)
						this.FixupFirstLefts1(outRec1, outRec2);
				}
			}
			else
			{
				//joined 2 polygons together ...
				outRec2.Pts = null;
				outRec2.BottomPt = null;
				outRec2.Idx = outRec1.Idx;
				outRec1.IsHole = holeStateRec.IsHole;
				if (holeStateRec === outRec2)
					outRec1.FirstLeft = outRec2.FirstLeft;
				outRec2.FirstLeft = outRec1;
				//fixup FirstLeft pointers that may need reassigning to OutRec1
				if (this.m_UsingPolyTree)
					this.FixupFirstLefts3(outRec2, outRec1);
			}
		}
	};

	ClipperLib.Clipper.prototype.UpdateOutPtIdxs = function (outrec)
	{
		var op = outrec.Pts;
		do {
			op.Idx = outrec.Idx;
			op = op.Prev;
		}
		while (op !== outrec.Pts)
	};

	ClipperLib.Clipper.prototype.DoSimplePolygons = function ()
	{
		var i = 0;
		while (i < this.m_PolyOuts.length)
		{
			var outrec = this.m_PolyOuts[i++];
			var op = outrec.Pts;
			if (op === null || outrec.IsOpen)
				continue;
			do //for each Pt in Polygon until duplicate found do ...
			{
				var op2 = op.Next;
				while (op2 !== outrec.Pts)
				{
					if ((ClipperLib.FPoint.op_Equality(op.Pt, op2.Pt)) && op2.Next !== op && op2.Prev !== op)
					{
						//split the polygon into two ...
						var op3 = op.Prev;
						var op4 = op2.Prev;
						op.Prev = op4;
						op4.Next = op;
						op2.Prev = op3;
						op3.Next = op2;
						outrec.Pts = op;
						var outrec2 = this.CreateOutRec();
						outrec2.Pts = op2;
						this.UpdateOutPtIdxs(outrec2);
						if (this.Poly2ContainsPoly1(outrec2.Pts, outrec.Pts))
						{
							//OutRec2 is contained by OutRec1 ...
							outrec2.IsHole = !outrec.IsHole;
							outrec2.FirstLeft = outrec;
							if (this.m_UsingPolyTree) this.FixupFirstLefts2(outrec2, outrec);

						}
						else if (this.Poly2ContainsPoly1(outrec.Pts, outrec2.Pts))
						{
							//OutRec1 is contained by OutRec2 ...
							outrec2.IsHole = outrec.IsHole;
							outrec.IsHole = !outrec2.IsHole;
							outrec2.FirstLeft = outrec.FirstLeft;
							outrec.FirstLeft = outrec2;
							if (this.m_UsingPolyTree) this.FixupFirstLefts2(outrec, outrec2);
						}
						else
						{
							//the 2 polygons are separate ...
							outrec2.IsHole = outrec.IsHole;
							outrec2.FirstLeft = outrec.FirstLeft;
							if (this.m_UsingPolyTree) this.FixupFirstLefts1(outrec, outrec2);
						}
						op2 = op;
						//ie get ready for the next iteration
					}
					op2 = op2.Next;
				}
				op = op.Next;
			}
			while (op !== outrec.Pts)
		}
	};

	ClipperLib.Clipper.Area = function (poly)
	{
		if (!Array.isArray(poly))
			return 0;
		var cnt = poly.length;
		if (cnt < 3)
			return 0;
		var a = 0;
		for (var i = 0, j = cnt - 1; i < cnt; ++i)
		{
			a += (poly[j].X + poly[i].X) * (poly[j].Y - poly[i].Y);
			j = i;
		}
		return -a * 0.5;
	};

	ClipperLib.Clipper.prototype.Area = function (op)
	{
		var opFirst = op;
		if (op === null) return 0;
		var a = 0;
		do {
			a = a + (op.Prev.Pt.X + op.Pt.X) * (op.Prev.Pt.Y - op.Pt.Y);
			op = op.Next;
		} while (op !== opFirst); // && typeof op !== 'undefined');
		return a * 0.5;
	}

	ClipperLib.Clipper.prototype.Area$1 = function (outRec)
	{
		return this.Area(outRec.Pts);
	};

	ClipperLib.Clipper.SimplifyPolygon = function (poly, fillType)
	{
		var result = new Array();
		var c = new ClipperLib.Clipper(0);
		c.StrictlySimple = true;
		c.AddPath(poly, ClipperLib.PolyType.ptSubject, true);
		c.Execute(ClipperLib.ClipType.ctUnion, result, fillType, fillType);
		return result;
	};

	ClipperLib.Clipper.SimplifyPolygons = function (polys, fillType)
	{
		if (typeof (fillType) === "undefined") fillType = ClipperLib.PolyFillType.pftEvenOdd;
		var result = new Array();
		var c = new ClipperLib.Clipper(0);
		c.StrictlySimple = true;
		c.AddPaths(polys, ClipperLib.PolyType.ptSubject, true);
		c.Execute(ClipperLib.ClipType.ctUnion, result, fillType, fillType);
		return result;
	};

	ClipperLib.Clipper.DistanceSqrd = function (pt1, pt2)
	{
		var dx = (pt1.X - pt2.X);
		var dy = (pt1.Y - pt2.Y);
		return (dx * dx + dy * dy);
	};

	ClipperLib.Clipper.DistanceFromLineSqrd = function (pt, ln1, ln2)
	{
		//The equation of a line in general form (Ax + By + C = 0)
		//given 2 points (x¹,y¹) & (x²,y²) is ...
		//(y¹ - y²)x + (x² - x¹)y + (y² - y¹)x¹ - (x² - x¹)y¹ = 0
		//A = (y¹ - y²); B = (x² - x¹); C = (y² - y¹)x¹ - (x² - x¹)y¹
		//perpendicular distance of point (x³,y³) = (Ax³ + By³ + C)/Sqrt(A² + B²)
		//see http://en.wikipedia.org/wiki/Perpendicular_distance
		var A = ln1.Y - ln2.Y;
		var B = ln2.X - ln1.X;
		var C = A * ln1.X + B * ln1.Y;
		C = A * pt.X + B * pt.Y - C;
		return (C * C) / (A * A + B * B);
	};

	ClipperLib.Clipper.SlopesNearCollinear = function (pt1, pt2, pt3, distSqrd)
	{
		//this function is more accurate when the point that's GEOMETRICALLY
		//between the other 2 points is the one that's tested for distance.
		//nb: with 'spikes', either pt1 or pt3 is geometrically between the other pts
		if (Math.abs(pt1.X - pt2.X) > Math.abs(pt1.Y - pt2.Y))
		{
			if ((pt1.X > pt2.X) === (pt1.X < pt3.X))
				return ClipperLib.Clipper.DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
			else if ((pt2.X > pt1.X) === (pt2.X < pt3.X))
				return ClipperLib.Clipper.DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
			else
				return ClipperLib.Clipper.DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
		}
		else
		{
			if ((pt1.Y > pt2.Y) === (pt1.Y < pt3.Y))
				return ClipperLib.Clipper.DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
			else if ((pt2.Y > pt1.Y) === (pt2.Y < pt3.Y))
				return ClipperLib.Clipper.DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
			else
				return ClipperLib.Clipper.DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
		}
	}

	ClipperLib.Clipper.PointsAreClose = function (pt1, pt2, distSqrd)
	{
		var dx = pt1.X - pt2.X;
		var dy = pt1.Y - pt2.Y;
		return ((dx * dx) + (dy * dy) <= distSqrd);
	};

	ClipperLib.Clipper.ExcludeOp = function (op)
	{
		var result = op.Prev;
		result.Next = op.Next;
		op.Next.Prev = result;
		result.Idx = 0;
		return result;
	};

	ClipperLib.Clipper.CleanPolygon = function (path, distance)
	{
		if (typeof (distance) === "undefined") distance = 1.415;
		//distance = proximity in units/pixels below which vertices will be stripped.
		//Default ~= sqrt(2) so when adjacent vertices or semi-adjacent vertices have
		//both x & y coords within 1 unit, then the second vertex will be stripped.
		var cnt = path.length;
		if (cnt === 0)
			return new Array();
		var outPts = new Array(cnt);
		for (var i = 0; i < cnt; ++i)
			outPts[i] = new ClipperLib.OutPt();
		for (var i = 0; i < cnt; ++i)
		{
			outPts[i].Pt = path[i];
			outPts[i].Next = outPts[(i + 1) % cnt];
			outPts[i].Next.Prev = outPts[i];
			outPts[i].Idx = 0;
		}
		var distSqrd = distance * distance;
		var op = outPts[0];
		while (op.Idx === 0 && op.Next !== op.Prev)
		{
			if (ClipperLib.Clipper.PointsAreClose(op.Pt, op.Prev.Pt, distSqrd))
			{
				op = ClipperLib.Clipper.ExcludeOp(op);
				cnt--;
			}
			else if (ClipperLib.Clipper.PointsAreClose(op.Prev.Pt, op.Next.Pt, distSqrd))
			{
				ClipperLib.Clipper.ExcludeOp(op.Next);
				op = ClipperLib.Clipper.ExcludeOp(op);
				cnt -= 2;
			}
			else if (ClipperLib.Clipper.SlopesNearCollinear(op.Prev.Pt, op.Pt, op.Next.Pt, distSqrd))
			{
				op = ClipperLib.Clipper.ExcludeOp(op);
				cnt--;
			}
			else
			{
				op.Idx = 1;
				op = op.Next;
			}
		}
		if (cnt < 3)
			cnt = 0;
		var result = new Array(cnt);
		for (var i = 0; i < cnt; ++i)
		{
			result[i] = new ClipperLib.FPoint1(op.Pt);
			op = op.Next;
		}
		outPts = null;
		return result;
	};

	ClipperLib.Clipper.CleanPolygons = function (polys, distance)
	{
		var result = new Array(polys.length);
		for (var i = 0, ilen = polys.length; i < ilen; i++)
			result[i] = ClipperLib.Clipper.CleanPolygon(polys[i], distance);
		return result;
	};

	ClipperLib.Clipper.Minkowski = function (pattern, path, IsSum, IsClosed)
	{
		var delta = (IsClosed ? 1 : 0);
		var polyCnt = pattern.length;
		var pathCnt = path.length;
		var result = new Array();
		if (IsSum)
			for (var i = 0; i < pathCnt; i++)
			{
				var p = new Array(polyCnt);
				for (var j = 0, jlen = pattern.length, ip = pattern[j]; j < jlen; j++, ip = pattern[j])
					p[j] = new ClipperLib.FPoint2(path[i].X + ip.X, path[i].Y + ip.Y);
				result.push(p);
			}
		else
			for (var i = 0; i < pathCnt; i++)
			{
				var p = new Array(polyCnt);
				for (var j = 0, jlen = pattern.length, ip = pattern[j]; j < jlen; j++, ip = pattern[j])
					p[j] = new ClipperLib.FPoint2(path[i].X - ip.X, path[i].Y - ip.Y);
				result.push(p);
			}
		var quads = new Array();
		for (var i = 0; i < pathCnt - 1 + delta; i++)
			for (var j = 0; j < polyCnt; j++)
			{
				var quad = new Array();
				quad.push(result[i % pathCnt][j % polyCnt]);
				quad.push(result[(i + 1) % pathCnt][j % polyCnt]);
				quad.push(result[(i + 1) % pathCnt][(j + 1) % polyCnt]);
				quad.push(result[i % pathCnt][(j + 1) % polyCnt]);
				if (!ClipperLib.Clipper.Orientation(quad))
					quad.reverse();
				quads.push(quad);
			}
		return quads;
	};

	ClipperLib.Clipper.MinkowskiSum = function (pattern, path_or_paths, pathIsClosed)
	{
		if (!(path_or_paths[0] instanceof Array))
		{
			var path = path_or_paths;
			var paths = ClipperLib.Clipper.Minkowski(pattern, path, true, pathIsClosed);
			var c = new ClipperLib.Clipper();
			c.AddPaths(paths, ClipperLib.PolyType.ptSubject, true);
			c.Execute(ClipperLib.ClipType.ctUnion, paths, ClipperLib.PolyFillType.pftNonZero, ClipperLib.PolyFillType.pftNonZero);
			return paths;
		}
		else
		{
			var paths = path_or_paths;
			var solution = new ClipperLib.Paths();
			var c = new ClipperLib.Clipper();
			for (var i = 0; i < paths.length; ++i)
			{
				var tmp = ClipperLib.Clipper.Minkowski(pattern, paths[i], true, pathIsClosed);
				c.AddPaths(tmp, ClipperLib.PolyType.ptSubject, true);
				if (pathIsClosed)
				{
					var path = ClipperLib.Clipper.TranslatePath(paths[i], pattern[0]);
					c.AddPath(path, ClipperLib.PolyType.ptClip, true);
				}
			}
			c.Execute(ClipperLib.ClipType.ctUnion, solution,
				ClipperLib.PolyFillType.pftNonZero, ClipperLib.PolyFillType.pftNonZero);
			return solution;
		}
	}

	ClipperLib.Clipper.TranslatePath = function (path, delta)
	{
		var outPath = new ClipperLib.Path();
		for (var i = 0; i < path.length; i++)
			outPath.push(new ClipperLib.FPoint2(path[i].X + delta.X, path[i].Y + delta.Y));
		return outPath;
	}

	ClipperLib.Clipper.MinkowskiDiff = function (poly1, poly2)
	{
		var paths = ClipperLib.Clipper.Minkowski(poly1, poly2, false, true);
		var c = new ClipperLib.Clipper();
		c.AddPaths(paths, ClipperLib.PolyType.ptSubject, true);
		c.Execute(ClipperLib.ClipType.ctUnion, paths, ClipperLib.PolyFillType.pftNonZero, ClipperLib.PolyFillType.pftNonZero);
		return paths;
	}

	ClipperLib.Clipper.PolyTreeToPaths = function (polytree)
	{
		var result = new Array();
		//result.set_Capacity(polytree.get_Total());
		ClipperLib.Clipper.AddPolyNodeToPaths(polytree, ClipperLib.Clipper.NodeType.ntAny, result);
		return result;
	};

	ClipperLib.Clipper.AddPolyNodeToPaths = function (polynode, nt, paths)
	{
		var match = true;
		switch (nt)
		{
			case ClipperLib.Clipper.NodeType.ntOpen:
				return;
			case ClipperLib.Clipper.NodeType.ntClosed:
				match = !polynode.IsOpen;
				break;
			default:
				break;
		}
		if (polynode.m_polygon.length > 0 && match)
			paths.push(polynode.m_polygon);
		for (var $i3 = 0, $t3 = polynode.Childs(), $l3 = $t3.length, pn = $t3[$i3]; $i3 < $l3; $i3++, pn = $t3[$i3])
			ClipperLib.Clipper.AddPolyNodeToPaths(pn, nt, paths);
	};

	ClipperLib.Clipper.OpenPathsFromPolyTree = function (polytree)
	{
		var result = new ClipperLib.Paths();
		//result.set_Capacity(polytree.ChildCount());
		for (var i = 0, ilen = polytree.ChildCount(); i < ilen; i++)
			if (polytree.Childs()[i].IsOpen)
				result.push(polytree.Childs()[i].m_polygon);
		return result;
	};

	ClipperLib.Clipper.ClosedPathsFromPolyTree = function (polytree)
	{
		var result = new ClipperLib.Paths();
		//result.set_Capacity(polytree.Total());
		ClipperLib.Clipper.AddPolyNodeToPaths(polytree, ClipperLib.Clipper.NodeType.ntClosed, result);
		return result;
	};

	Inherit(ClipperLib.Clipper, ClipperLib.ClipperBase);
	ClipperLib.Clipper.NodeType = {
		ntAny: 0,
		ntOpen: 1,
		ntClosed: 2
	};

	/**
	* @constructor
	*/
	ClipperLib.ClipperOffset = function (miterLimit, arcTolerance)
	{
		if (typeof (miterLimit) === "undefined") miterLimit = 2;
		if (typeof (arcTolerance) === "undefined") arcTolerance = ClipperLib.ClipperOffset.def_arc_tolerance;
		this.m_destPolys = new ClipperLib.Paths();
		this.m_srcPoly = new ClipperLib.Path();
		this.m_destPoly = new ClipperLib.Path();
		this.m_normals = new Array();
		this.m_delta = 0;
		this.m_sinA = 0;
		this.m_sin = 0;
		this.m_cos = 0;
		this.m_miterLim = 0;
		this.m_StepsPerRad = 0;
		this.m_lowest = new ClipperLib.FPoint0();
		this.m_polyNodes = new ClipperLib.PolyNode();
		this.MiterLimit = miterLimit;
		this.ArcTolerance = arcTolerance;
		this.m_lowest.X = -1;
	};

	ClipperLib.ClipperOffset.two_pi = 6.28318530717959;
	ClipperLib.ClipperOffset.def_arc_tolerance = 0.25;
	ClipperLib.ClipperOffset.prototype.Clear = function ()
	{
		ClipperLib.Clear(this.m_polyNodes.Childs());
		this.m_lowest.X = -1;
	};

	ClipperLib.ClipperOffset.prototype.AddPath = function (path, joinType, endType)
	{
		var highI = path.length - 1;
		if (highI < 0)
			return;
		var newNode = new ClipperLib.PolyNode();
		newNode.m_jointype = joinType;
		newNode.m_endtype = endType;
		//strip duplicate points from path and also get index to the lowest point ...
		if (endType === ClipperLib.EndType.etClosedLine || endType === ClipperLib.EndType.etClosedPolygon)
			while (highI > 0 && ClipperLib.FPoint.op_Equality(path[0], path[highI]))
				highI--;
		//newNode.m_polygon.set_Capacity(highI + 1);
		newNode.m_polygon.push(path[0]);
		var j = 0,
			k = 0;
		for (var i = 1; i <= highI; i++)
			if (ClipperLib.FPoint.op_Inequality(newNode.m_polygon[j], path[i]))
			{
				j++;
				newNode.m_polygon.push(path[i]);
				if (path[i].Y > newNode.m_polygon[k].Y || (path[i].Y === newNode.m_polygon[k].Y && path[i].X < newNode.m_polygon[k].X))
					k = j;
			}
		if (endType === ClipperLib.EndType.etClosedPolygon && j < 2) return;

		this.m_polyNodes.AddChild(newNode);
		//if this path's lowest pt is lower than all the others then update m_lowest
		if (endType !== ClipperLib.EndType.etClosedPolygon)
			return;
		if (this.m_lowest.X < 0)
			this.m_lowest = new ClipperLib.FPoint2(this.m_polyNodes.ChildCount() - 1, k);
		else
		{
			var ip = this.m_polyNodes.Childs()[this.m_lowest.X].m_polygon[this.m_lowest.Y];
			if (newNode.m_polygon[k].Y > ip.Y || (newNode.m_polygon[k].Y === ip.Y && newNode.m_polygon[k].X < ip.X))
				this.m_lowest = new ClipperLib.FPoint2(this.m_polyNodes.ChildCount() - 1, k);
		}
	};

	ClipperLib.ClipperOffset.prototype.AddPaths = function (paths, joinType, endType)
	{
		for (var i = 0, ilen = paths.length; i < ilen; i++)
			this.AddPath(paths[i], joinType, endType);
	};

	ClipperLib.ClipperOffset.prototype.FixOrientations = function ()
	{
		//fixup orientations of all closed paths if the orientation of the
		//closed path with the lowermost vertex is wrong ...
		if (this.m_lowest.X >= 0 && !ClipperLib.Clipper.Orientation(this.m_polyNodes.Childs()[this.m_lowest.X].m_polygon))
		{
			for (var i = 0; i < this.m_polyNodes.ChildCount(); i++)
			{
				var node = this.m_polyNodes.Childs()[i];
				if (node.m_endtype === ClipperLib.EndType.etClosedPolygon || (node.m_endtype === ClipperLib.EndType.etClosedLine && ClipperLib.Clipper.Orientation(node.m_polygon)))
					node.m_polygon.reverse();
			}
		}
		else
		{
			for (var i = 0; i < this.m_polyNodes.ChildCount(); i++)
			{
				var node = this.m_polyNodes.Childs()[i];
				if (node.m_endtype === ClipperLib.EndType.etClosedLine && !ClipperLib.Clipper.Orientation(node.m_polygon))
					node.m_polygon.reverse();
			}
		}
	};

	ClipperLib.ClipperOffset.GetUnitNormal = function (pt1, pt2)
	{
		var dx = (pt2.X - pt1.X);
		var dy = (pt2.Y - pt1.Y);
		if ((dx === 0) && (dy === 0))
			return new ClipperLib.FPoint2(0, 0);
		var f = 1 / Math.sqrt(dx * dx + dy * dy);
		dx *= f;
		dy *= f;
		return new ClipperLib.FPoint2(dy, -dx);
	};

	ClipperLib.ClipperOffset.prototype.DoOffset = function (delta)
	{
		this.m_destPolys = new Array();
		this.m_delta = delta;
		//if Zero offset, just copy any CLOSED polygons to m_p and return ...
		if (ClipperLib.ClipperBase.near_zero(delta))
		{
			//this.m_destPolys.set_Capacity(this.m_polyNodes.ChildCount);
			for (var i = 0; i < this.m_polyNodes.ChildCount(); i++)
			{
				var node = this.m_polyNodes.Childs()[i];
				if (node.m_endtype === ClipperLib.EndType.etClosedPolygon)
					this.m_destPolys.push(node.m_polygon);
			}
			return;
		}
		//see offset_triginometry3.svg in the documentation folder ...
		if (this.MiterLimit > 2)
			this.m_miterLim = 2 / (this.MiterLimit * this.MiterLimit);
		else
			this.m_miterLim = 0.5;
		var y;
		if (this.ArcTolerance <= 0)
			y = ClipperLib.ClipperOffset.def_arc_tolerance;
		else if (this.ArcTolerance > Math.abs(delta) * ClipperLib.ClipperOffset.def_arc_tolerance)
			y = Math.abs(delta) * ClipperLib.ClipperOffset.def_arc_tolerance;
		else
			y = this.ArcTolerance;
		//see offset_triginometry2.svg in the documentation folder ...
		var steps = 3.14159265358979 / Math.acos(1 - y / Math.abs(delta));
		this.m_sin = Math.sin(ClipperLib.ClipperOffset.two_pi / steps);
		this.m_cos = Math.cos(ClipperLib.ClipperOffset.two_pi / steps);
		this.m_StepsPerRad = steps / ClipperLib.ClipperOffset.two_pi;
		if (delta < 0)
			this.m_sin = -this.m_sin;
		//this.m_destPolys.set_Capacity(this.m_polyNodes.ChildCount * 2);
		for (var i = 0; i < this.m_polyNodes.ChildCount(); i++)
		{
			var node = this.m_polyNodes.Childs()[i];
			this.m_srcPoly = node.m_polygon;
			var len = this.m_srcPoly.length;
			if (len === 0 || (delta <= 0 && (len < 3 || node.m_endtype !== ClipperLib.EndType.etClosedPolygon)))
				continue;
			this.m_destPoly = new Array();
			if (len === 1)
			{
				if (node.m_jointype === ClipperLib.JoinType.jtRound)
				{
					var X = 1,
						Y = 0;
					for (var j = 1; j <= steps; j++)
					{
						this.m_destPoly.push(new ClipperLib.FPoint2(this.m_srcPoly[0].X + X * delta, this.m_srcPoly[0].Y + Y * delta));
						var X2 = X;
						X = X * this.m_cos - this.m_sin * Y;
						Y = X2 * this.m_sin + Y * this.m_cos;
					}
				}
				else
				{
					var X = -1,
						Y = -1;
					for (var j = 0; j < 4; ++j)
					{
						this.m_destPoly.push(new ClipperLib.FPoint2(this.m_srcPoly[0].X + X * delta, this.m_srcPoly[0].Y + Y * delta));
						if (X < 0)
							X = 1;
						else if (Y < 0)
							Y = 1;
						else
							X = -1;
					}
				}
				this.m_destPolys.push(this.m_destPoly);
				continue;
			}
			//build m_normals ...
			this.m_normals.length = 0;
			//this.m_normals.set_Capacity(len);
			for (var j = 0; j < len - 1; j++)
				this.m_normals.push(ClipperLib.ClipperOffset.GetUnitNormal(this.m_srcPoly[j], this.m_srcPoly[j + 1]));
			if (node.m_endtype === ClipperLib.EndType.etClosedLine || node.m_endtype === ClipperLib.EndType.etClosedPolygon)
				this.m_normals.push(ClipperLib.ClipperOffset.GetUnitNormal(this.m_srcPoly[len - 1], this.m_srcPoly[0]));
			else
				this.m_normals.push(new ClipperLib.FPoint1(this.m_normals[len - 2]));
			if (node.m_endtype === ClipperLib.EndType.etClosedPolygon)
			{
				var k = len - 1;
				for (var j = 0; j < len; j++)
					k = this.OffsetPoint(j, k, node.m_jointype);
				this.m_destPolys.push(this.m_destPoly);
			}
			else if (node.m_endtype === ClipperLib.EndType.etClosedLine)
			{
				var k = len - 1;
				for (var j = 0; j < len; j++)
					k = this.OffsetPoint(j, k, node.m_jointype);
				this.m_destPolys.push(this.m_destPoly);
				this.m_destPoly = new Array();
				//re-build m_normals ...
				var n = this.m_normals[len - 1];
				for (var j = len - 1; j > 0; j--)
					this.m_normals[j] = new ClipperLib.FPoint2(-this.m_normals[j - 1].X, -this.m_normals[j - 1].Y);
				this.m_normals[0] = new ClipperLib.FPoint2(-n.X, -n.Y);
				k = 0;
				for (var j = len - 1; j >= 0; j--)
					k = this.OffsetPoint(j, k, node.m_jointype);
				this.m_destPolys.push(this.m_destPoly);
			}
			else
			{
				var k = 0;
				for (var j = 1; j < len - 1; ++j)
					k = this.OffsetPoint(j, k, node.m_jointype);
				var pt1;
				if (node.m_endtype === ClipperLib.EndType.etOpenButt)
				{
					var j = len - 1;
					pt1 = new ClipperLib.FPoint2(this.m_srcPoly[j].X + this.m_normals[j].X * delta, this.m_srcPoly[j].Y + this.m_normals[j].Y * delta);
					this.m_destPoly.push(pt1);
					pt1 = new ClipperLib.FPoint2(this.m_srcPoly[j].X - this.m_normals[j].X * delta, this.m_srcPoly[j].Y - this.m_normals[j].Y * delta);
					this.m_destPoly.push(pt1);
				}
				else
				{
					var j = len - 1;
					k = len - 2;
					this.m_sinA = 0;
					this.m_normals[j] = new ClipperLib.FPoint2(-this.m_normals[j].X, -this.m_normals[j].Y);
					if (node.m_endtype === ClipperLib.EndType.etOpenSquare)
						this.DoSquare(j, k);
					else
						this.DoRound(j, k);
				}
				//re-build m_normals ...
				for (var j = len - 1; j > 0; j--)
					this.m_normals[j] = new ClipperLib.FPoint2(-this.m_normals[j - 1].X, -this.m_normals[j - 1].Y);
				this.m_normals[0] = new ClipperLib.FPoint2(-this.m_normals[1].X, -this.m_normals[1].Y);
				k = len - 1;
				for (var j = k - 1; j > 0; --j)
					k = this.OffsetPoint(j, k, node.m_jointype);
				if (node.m_endtype === ClipperLib.EndType.etOpenButt)
				{
					pt1 = new ClipperLib.FPoint2(this.m_srcPoly[0].X - this.m_normals[0].X * delta, this.m_srcPoly[0].Y - this.m_normals[0].Y * delta);
					this.m_destPoly.push(pt1);
					pt1 = new ClipperLib.FPoint2(this.m_srcPoly[0].X + this.m_normals[0].X * delta, this.m_srcPoly[0].Y + this.m_normals[0].Y * delta);
					this.m_destPoly.push(pt1);
				}
				else
				{
					k = 1;
					this.m_sinA = 0;
					if (node.m_endtype === ClipperLib.EndType.etOpenSquare)
						this.DoSquare(0, 1);
					else
						this.DoRound(0, 1);
				}
				this.m_destPolys.push(this.m_destPoly);
			}
		}
	};

	ClipperLib.ClipperOffset.prototype.Execute = function ()
	{
		var a = arguments,
			ispolytree = a[0] instanceof ClipperLib.PolyTree;
		if (!ispolytree) // function (solution, delta)
		{
			var solution = a[0],
				delta = a[1];
			ClipperLib.Clear(solution);
			this.FixOrientations();
			this.DoOffset(delta);
			//now clean up 'corners' ...
			var clpr = new ClipperLib.Clipper(0);
			clpr.AddPaths(this.m_destPolys, ClipperLib.PolyType.ptSubject, true);
			if (delta > 0)
			{
				clpr.Execute(ClipperLib.ClipType.ctUnion, solution, ClipperLib.PolyFillType.pftPositive, ClipperLib.PolyFillType.pftPositive);
			}
			else
			{
				var r = ClipperLib.Clipper.GetBounds(this.m_destPolys);
				var outer = new ClipperLib.Path();
				outer.push(new ClipperLib.FPoint2(r.left - 10, r.bottom + 10));
				outer.push(new ClipperLib.FPoint2(r.right + 10, r.bottom + 10));
				outer.push(new ClipperLib.FPoint2(r.right + 10, r.top - 10));
				outer.push(new ClipperLib.FPoint2(r.left - 10, r.top - 10));
				clpr.AddPath(outer, ClipperLib.PolyType.ptSubject, true);
				clpr.ReverseSolution = true;
				clpr.Execute(ClipperLib.ClipType.ctUnion, solution, ClipperLib.PolyFillType.pftNegative, ClipperLib.PolyFillType.pftNegative);
				if (solution.length > 0)
					solution.splice(0, 1);
			}
			//console.log(JSON.stringify(solution));
		}
		else // function (polytree, delta)
		{
			var solution = a[0],
				delta = a[1];
			solution.Clear();
			this.FixOrientations();
			this.DoOffset(delta);
			//now clean up 'corners' ...
			var clpr = new ClipperLib.Clipper(0);
			clpr.AddPaths(this.m_destPolys, ClipperLib.PolyType.ptSubject, true);
			if (delta > 0)
			{
				clpr.Execute(ClipperLib.ClipType.ctUnion, solution, ClipperLib.PolyFillType.pftPositive, ClipperLib.PolyFillType.pftPositive);
			}
			else
			{
				var r = ClipperLib.Clipper.GetBounds(this.m_destPolys);
				var outer = new ClipperLib.Path();
				outer.push(new ClipperLib.FPoint2(r.left - 10, r.bottom + 10));
				outer.push(new ClipperLib.FPoint2(r.right + 10, r.bottom + 10));
				outer.push(new ClipperLib.FPoint2(r.right + 10, r.top - 10));
				outer.push(new ClipperLib.FPoint2(r.left - 10, r.top - 10));
				clpr.AddPath(outer, ClipperLib.PolyType.ptSubject, true);
				clpr.ReverseSolution = true;
				clpr.Execute(ClipperLib.ClipType.ctUnion, solution, ClipperLib.PolyFillType.pftNegative, ClipperLib.PolyFillType.pftNegative);
				//remove the outer PolyNode rectangle ...
				if (solution.ChildCount() === 1 && solution.Childs()[0].ChildCount() > 0)
				{
					var outerNode = solution.Childs()[0];
					//solution.Childs.set_Capacity(outerNode.ChildCount);
					solution.Childs()[0] = outerNode.Childs()[0];
					solution.Childs()[0].m_Parent = solution;
					for (var i = 1; i < outerNode.ChildCount(); i++)
						solution.AddChild(outerNode.Childs()[i]);
				}
				else
					solution.Clear();
			}
		}
	};

	ClipperLib.ClipperOffset.prototype.OffsetPoint = function (j, k, jointype)
	{
		//cross product ...
		this.m_sinA = (this.m_normals[k].X * this.m_normals[j].Y - this.m_normals[j].X * this.m_normals[k].Y);

		if (this.m_sinA === 0)
		{
      return k;
		}

/*
		else if (this.m_sinA < 0.00005 && this.m_sinA > -0.00005)
{
			console.log(this.m_sinA);
      return k;
}
*/
/*
		if (Math.abs(this.m_sinA * this.m_delta) < 1.0)
		{
			//dot product ...
			var cosA = (this.m_normals[k].X * this.m_normals[j].X + this.m_normals[j].Y * this.m_normals[k].Y);
			if (cosA > 0) // angle ==> 0 degrees
			{
				this.m_destPoly.push(new ClipperLib.FPoint2(this.m_srcPoly[j].X + this.m_normals[k].X * this.m_delta,
					this.m_srcPoly[j].Y + this.m_normals[k].Y * this.m_delta));
				return k;
			}
			//else angle ==> 180 degrees
		}
*/
		else if (this.m_sinA > 1)
			this.m_sinA = 1.0;
		else if (this.m_sinA < -1)
			this.m_sinA = -1.0;
		if (this.m_sinA * this.m_delta < 0)
		{
			this.m_destPoly.push(new ClipperLib.FPoint2(this.m_srcPoly[j].X + this.m_normals[k].X * this.m_delta,
				this.m_srcPoly[j].Y + this.m_normals[k].Y * this.m_delta));
			this.m_destPoly.push(new ClipperLib.FPoint1(this.m_srcPoly[j]));
			this.m_destPoly.push(new ClipperLib.FPoint2(this.m_srcPoly[j].X + this.m_normals[j].X * this.m_delta,
				this.m_srcPoly[j].Y + this.m_normals[j].Y * this.m_delta));
		}
		else
			switch (jointype)
			{
			case ClipperLib.JoinType.jtMiter:
				{
					var r = 1 + (this.m_normals[j].X * this.m_normals[k].X + this.m_normals[j].Y * this.m_normals[k].Y);
					if (r >= this.m_miterLim)
						this.DoMiter(j, k, r);
					else
						this.DoSquare(j, k);
					break;
				}
			case ClipperLib.JoinType.jtSquare:
				this.DoSquare(j, k);
				break;
			case ClipperLib.JoinType.jtRound:
				this.DoRound(j, k);
				break;
			}
		k = j;
		return k;
	};

	ClipperLib.ClipperOffset.prototype.DoSquare = function (j, k)
	{
		var dx = Math.tan(Math.atan2(this.m_sinA,
			this.m_normals[k].X * this.m_normals[j].X + this.m_normals[k].Y * this.m_normals[j].Y) / 4);
		this.m_destPoly.push(new ClipperLib.FPoint2(
			this.m_srcPoly[j].X + this.m_delta * (this.m_normals[k].X - this.m_normals[k].Y * dx),
			this.m_srcPoly[j].Y + this.m_delta * (this.m_normals[k].Y + this.m_normals[k].X * dx)));
		this.m_destPoly.push(new ClipperLib.FPoint2(
			this.m_srcPoly[j].X + this.m_delta * (this.m_normals[j].X + this.m_normals[j].Y * dx),
			this.m_srcPoly[j].Y + this.m_delta * (this.m_normals[j].Y - this.m_normals[j].X * dx)));
	};

	ClipperLib.ClipperOffset.prototype.DoMiter = function (j, k, r)
	{
		var q = this.m_delta / r;
		this.m_destPoly.push(new ClipperLib.FPoint2(
			this.m_srcPoly[j].X + (this.m_normals[k].X + this.m_normals[j].X) * q,
			this.m_srcPoly[j].Y + (this.m_normals[k].Y + this.m_normals[j].Y) * q));
	};

	ClipperLib.ClipperOffset.prototype.DoRound = function (j, k)
	{
		var a = Math.atan2(this.m_sinA,
			this.m_normals[k].X * this.m_normals[j].X + this.m_normals[k].Y * this.m_normals[j].Y);

		var steps = Math.max(Math.round(this.m_StepsPerRad * Math.abs(a)), 1);

		var X = this.m_normals[k].X,
			Y = this.m_normals[k].Y,
			X2;
		for (var i = 0; i < steps; ++i)
		{
			this.m_destPoly.push(new ClipperLib.FPoint2(
				this.m_srcPoly[j].X + X * this.m_delta,
				this.m_srcPoly[j].Y + Y * this.m_delta));
			X2 = X;
			X = X * this.m_cos - this.m_sin * Y;
			Y = X2 * this.m_sin + Y * this.m_cos;
		}
		this.m_destPoly.push(new ClipperLib.FPoint2(
			this.m_srcPoly[j].X + this.m_normals[j].X * this.m_delta,
			this.m_srcPoly[j].Y + this.m_normals[j].Y * this.m_delta));
	};

	ClipperLib.Error = function (message)
	{
		try
		{
			throw new Error(message);
		}
		catch (err)
		{
			alert(err.message);
		}
	};

	// ---------------------------------------------

	// JS extension by Timo 2013
	ClipperLib.JS = {};

	ClipperLib.JS.AreaOfPolygon = function (poly)
	{
		return ClipperLib.Clipper.Area(poly);
	};

	ClipperLib.JS.AreaOfPolygons = function (poly)
	{
		var area = 0;
		for (var i = 0; i < poly.length; i++)
		{
			area += ClipperLib.Clipper.Area(poly[i]);
		}
		return area;
	};

	ClipperLib.JS.BoundsOfPath = function (path)
	{
		return ClipperLib.JS.BoundsOfPaths([path]);
	};

	ClipperLib.JS.BoundsOfPaths = function (paths)
	{
		var bounds = ClipperLib.Clipper.GetBounds(paths);
		return bounds;
	};

	// Clean() joins vertices that are too near each other
	// and causes distortion to offsetted polygons without cleaning
	ClipperLib.JS.Clean = function (polygon, delta)
	{
		if (!(polygon instanceof Array)) return [];
		var isPolygons = polygon[0] instanceof Array;
		var polygon = ClipperLib.JS.Clone(polygon);
		if (typeof delta !== "number" || delta === null)
		{
			ClipperLib.Error("Delta is not a number in Clean().");
			return polygon;
		}
		if (polygon.length === 0 || (polygon.length === 1 && polygon[0].length === 0) || delta < 0) return polygon;
		if (!isPolygons) polygon = [polygon];
		var k_length = polygon.length;
		var len, poly, result, d, p, j, i;
		var results = [];
		for (var k = 0; k < k_length; k++)
		{
			poly = polygon[k];
			len = poly.length;
			if (len === 0) continue;
			else if (len < 3)
			{
				result = poly;
				results.push(result);
				continue;
			}
			result = poly;
			d = delta * delta;
			//d = Math.floor(c_delta * c_delta);
			p = poly[0];
			j = 1;
			for (i = 1; i < len; i++)
			{
				if ((poly[i].X - p.X) * (poly[i].X - p.X) +
					(poly[i].Y - p.Y) * (poly[i].Y - p.Y) <= d)
					continue;
				result[j] = poly[i];
				p = poly[i];
				j++;
			}
			p = poly[j - 1];
			if ((poly[0].X - p.X) * (poly[0].X - p.X) +
				(poly[0].Y - p.Y) * (poly[0].Y - p.Y) <= d)
				j--;
			if (j < len)
				result.splice(j, len - j);
			if (result.length) results.push(result);
		}
		if (!isPolygons && results.length) results = results[0];
		else if (!isPolygons && results.length === 0) results = [];
		else if (isPolygons && results.length === 0) results = [
			[]
		];
		return results;
	}
	// Make deep copy of Polygons or Polygon
	// so that also FPoint objects are cloned and not only referenced
	// This should be the fastest way
	ClipperLib.JS.Clone = function (polygon)
	{
		if (!(polygon instanceof Array)) return [];
		if (polygon.length === 0) return [];
		else if (polygon.length === 1 && polygon[0].length === 0) return [
			[]
		];
		var isPolygons = polygon[0] instanceof Array;
		if (!isPolygons) polygon = [polygon];
		var len = polygon.length,
			plen, i, j, result;
		var results = new Array(len);
		for (i = 0; i < len; i++)
		{
			plen = polygon[i].length;
			result = new Array(plen);
			for (j = 0; j < plen; j++)
			{
				result[j] = {
					X: polygon[i][j].X,
					Y: polygon[i][j].Y
				};

			}
			results[i] = result;
		}
		if (!isPolygons) results = results[0];
		return results;
	};

	// Removes points that doesn't affect much to the visual appearance.
	// If middle point is at or under certain distance (tolerance) of the line segment between
	// start and end point, the middle point is removed.
	ClipperLib.JS.Lighten = function (polygon, tolerance)
	{
		if (!(polygon instanceof Array)) return [];
		if (typeof tolerance !== "number" || tolerance === null)
		{
			ClipperLib.Error("Tolerance is not a number in Lighten().")
			return ClipperLib.JS.Clone(polygon);
		}
		if (polygon.length === 0 || (polygon.length === 1 && polygon[0].length === 0) || tolerance < 0)
		{
			return ClipperLib.JS.Clone(polygon);
		}
		var isPolygons = polygon[0] instanceof Array;
		if (!isPolygons) polygon = [polygon];
		var i, j, poly, k, poly2, plen, A, B, P, d, rem, addlast;
		var bxax, byay, l, ax, ay;
		var len = polygon.length;
		var toleranceSq = tolerance * tolerance;
		var results = [];
		for (i = 0; i < len; i++)
		{
			poly = polygon[i];
			plen = poly.length;
			if (plen === 0) continue;
			for (k = 0; k < 1000000; k++) // could be forever loop, but wiser to restrict max repeat count
			{
				poly2 = [];
				plen = poly.length;
				// the first have to added to the end, if first and last are not the same
				// this way we ensure that also the actual last point can be removed if needed
				if (poly[plen - 1].X !== poly[0].X || poly[plen - 1].Y !== poly[0].Y)
				{
					addlast = 1;
					poly.push(
					{
						X: poly[0].X,
						Y: poly[0].Y
					});
					plen = poly.length;
				}
				else addlast = 0;
				rem = []; // Indexes of removed points
				for (j = 0; j < plen - 2; j++)
				{
					A = poly[j]; // Start point of line segment
					P = poly[j + 1]; // Middle point. This is the one to be removed.
					B = poly[j + 2]; // End point of line segment
					ax = A.X;
					ay = A.Y;
					bxax = B.X - ax;
					byay = B.Y - ay;
					if (bxax !== 0 || byay !== 0) // To avoid Nan, when A==P && P==B. And to avoid peaks (A==B && A!=P), which have lenght, but not area.
					{
						l = ((P.X - ax) * bxax + (P.Y - ay) * byay) / (bxax * bxax + byay * byay);
						if (l > 1)
						{
							ax = B.X;
							ay = B.Y;
						}
						else if (l > 0)
						{
							ax += bxax * l;
							ay += byay * l;
						}
					}
					bxax = P.X - ax;
					byay = P.Y - ay;
					d = bxax * bxax + byay * byay;
					if (d <= toleranceSq)
					{
						rem[j + 1] = 1;
						j++; // when removed, transfer the pointer to the next one
					}
				}
				// add all unremoved points to poly2
				poly2.push(
				{
					X: poly[0].X,
					Y: poly[0].Y
				});
				for (j = 1; j < plen - 1; j++)
					if (!rem[j]) poly2.push(
					{
						X: poly[j].X,
						Y: poly[j].Y
					});
				poly2.push(
				{
					X: poly[plen - 1].X,
					Y: poly[plen - 1].Y
				});
				// if the first point was added to the end, remove it
				if (addlast) poly.pop();
				// break, if there was not anymore removed points
				if (!rem.length) break;
				// else continue looping using poly2, to check if there are points to remove
				else poly = poly2;
			}
			plen = poly2.length;
			// remove duplicate from end, if needed
			if (poly2[plen - 1].X === poly2[0].X && poly2[plen - 1].Y === poly2[0].Y)
			{
				poly2.pop();
			}
			if (poly2.length > 2) // to avoid two-point-polygons
				results.push(poly2);
		}
		if (!isPolygons)
		{
			results = results[0];
		}
		if (typeof (results) === "undefined")
		{
			results = [];
		}
		return results;
	}

	ClipperLib.JS.PerimeterOfPath = function (path, closed)
	{
		if (typeof (path) === "undefined") return 0;
		var sqrt = Math.sqrt;
		var perimeter = 0.0;
		var p1, p2, p1x = 0.0,
			p1y = 0.0,
			p2x = 0.0,
			p2y = 0.0;
		var j = path.length;
		if (j < 2) return 0;
		if (closed)
		{
			path[j] = path[0];
			j++;
		}
		while (--j)
		{
			p1 = path[j];
			p1x = p1.X;
			p1y = p1.Y;
			p2 = path[j - 1];
			p2x = p2.X;
			p2y = p2.Y;
			perimeter += sqrt((p1x - p2x) * (p1x - p2x) + (p1y - p2y) * (p1y - p2y));
		}
		if (closed) path.pop();
		return perimeter;
	};

	ClipperLib.JS.PerimeterOfPaths = function (paths, closed)
	{
		var perimeter = 0;
		for (var i = 0; i < paths.length; i++)
		{
			perimeter += ClipperLib.JS.PerimeterOfPath(paths[i], closed);
		}
		return perimeter;
	};

	/**
	* @constructor
	*/
	ClipperLib.ExPolygons = function ()
	{
		return [];
	}
	/**
	* @constructor
	*/
	ClipperLib.ExPolygon = function ()
	{
		this.outer = null;
		this.holes = null;
	};

	ClipperLib.JS.AddOuterPolyNodeToExPolygons = function (polynode, expolygons)
	{
		var ep = new ClipperLib.ExPolygon();
		ep.outer = polynode.Contour();
		var childs = polynode.Childs();
		var ilen = childs.length;
		ep.holes = new Array(ilen);
		var node, n, i, j, childs2, jlen;
		for (i = 0; i < ilen; i++)
		{
			node = childs[i];
			ep.holes[i] = node.Contour();
			//Add outer polygons contained by (nested within) holes ...
			for (j = 0, childs2 = node.Childs(), jlen = childs2.length; j < jlen; j++)
			{
				n = childs2[j];
				ClipperLib.JS.AddOuterPolyNodeToExPolygons(n, expolygons);
			}
		}
		expolygons.push(ep);
	};

	ClipperLib.JS.ExPolygonsToPaths = function (expolygons)
	{
		var a, i, alen, ilen;
		var paths = new ClipperLib.Paths();
		for (a = 0, alen = expolygons.length; a < alen; a++)
		{
			paths.push(expolygons[a].outer);
			for (i = 0, ilen = expolygons[a].holes.length; i < ilen; i++)
			{
				paths.push(expolygons[a].holes[i]);
			}
		}
		return paths;
	}
	ClipperLib.JS.PolyTreeToExPolygons = function (polytree)
	{
		var expolygons = new ClipperLib.ExPolygons();
		var node, i, childs, ilen;
		for (i = 0, childs = polytree.Childs(), ilen = childs.length; i < ilen; i++)
		{
			node = childs[i];
			ClipperLib.JS.AddOuterPolyNodeToExPolygons(node, expolygons);
		}
		return expolygons;
	};

})();