//-----------------------------------------------------------------------------+
// Copyright (C), 1998-2007, Beijing Tangent Software Co. Ltd.
// = FileName	:   TPGeEdge.h
// = Version	:   ver2.0
// = Author		:   xlc
// = CreateDate	:   2002-09-09
// = Description:   类的声明 有向边

// = Maintainers: 
//                  
//-----------------------------------------------------------------------------+
#ifndef _TPGEEDGE_H_
#define _TPGEEDGE_H_

#ifndef _TWFLAG_H_
#include "TWFlag.h"
#endif

#ifndef _TPGEEDGEPATH_H_
#include "TPGeEdgePath.h"
#endif

class TGNode;
class TPGeCurve2D;

class GEOAPI TPGeEdge : public TWFlag
{
public:
	
	TPGeEdge(TPGeCurve2D*p);
	
	virtual	~TPGeEdge();

	TPGeCurve2D* FetchEdge();
	
	TGNode* EndNode()const;

	void SetNode(TGNode*p1,TGNode*p2);

	//path找从经过这一边的可能的唯一环路(或者说是第一个环路)
	bool FindLoop(TPGeEdgePath&path);

	bool operator >(const TPGeEdge&)const;

	bool operator <(const TPGeEdge&)const;
	
protected:

	//不封闭曲线段或一端无限曲线
	TPGeCurve2D *pSeg;
	
	//起点
	TGNode *pNodeStart;
	
	//终点
	TGNode *pNodeEnd; 
};

#endif