//-----------------------------------------------------------------------------+
// Copyright (C), 1998-2007, Beijing Tangent Software Co. Ltd.
// = FileName	:   TGraphArc.cpp
// = Version	:   ver2.0
// = Author		:   xlc
// = CreateDate	:   2002-09-09
// = Description:   类的定义
// = Maintainers: 
//                  
//-----------------------------------------------------------------------------+
#include "StdAfx.h"
#include "TGraphArc.h"
#include "TGraphNode.h"
#include "TGraphPath.h"

TGraphArc::TGraphArc(TGraphNode* pNode0,TGraphNode*pNode1)
	: m_pNode0(pNode0),m_pNode1(pNode1)
{

}

TGraphArc::~TGraphArc()
{
	UnConnect();
}

TGraphNode* TGraphArc::GetNode(long i)
{
	return i == 0?m_pNode0:m_pNode1;
}

void TGraphArc::SetNode(long i,TGraphNode*pNode)
{
	if (i == 0)
	{
		m_pNode0=pNode;
	}
	else
	{
		m_pNode1=pNode;
	}
}

bool TGraphArc::IsValid() const
{
	return m_pNode0 != NULL && m_pNode1 != NULL;
}

bool TGraphArc::IsClosed() const
{
	return m_pNode0 == m_pNode1;
}

int TGraphArc::CmpArc(const TGraphArc&a) const
{
	return (int)(this-(&a));
}

bool TGraphArc::operator == (const TGraphArc&a) const
{
	return CmpArc(a) == 0;
}

bool TGraphArc::operator != (const TGraphArc&a) const
{
	return CmpArc(a) != 0;
}

bool TGraphArc::operator> (const TGraphArc&a) const
{
	return CmpArc(a)>0;
}

bool TGraphArc::operator< (const TGraphArc&a) const
{
	return CmpArc(a)<0;
}

void TGraphArc::Connect()
{
	if (m_pNode0 != NULL)
	{
		m_pNode0->AppendArc(this);
	}

	if (m_pNode1 != NULL)
	{
		m_pNode1->AppendArc(this);
	}
}

void TGraphArc::UnConnect()
{
	if (m_pNode0 != NULL)
	{
		m_pNode0->RemoveArc(this);
	}
	if (m_pNode1 != NULL)
	{
		m_pNode1->RemoveArc(this);
	}
	m_pNode0=NULL;
	m_pNode1=NULL;
}

TGraphPath* TGraphArc::FindMesh(int type)
{
	TGraphPath *pMesh=new TGraphPath;

	TGraphNode* pNodeStart;
	pNodeStart=type == 0?m_pNode0:m_pNode1;
	pMesh->SetStartNode(pNodeStart);
	TGraphArc*pEdge=this;
	do
	{
		pMesh->AddTail(pEdge);
		pNodeStart=pEdge->GetOtherNode(pNodeStart);
		pEdge=pNodeStart->FindNextArc(pEdge);
	}while(pEdge != this && pEdge != NULL);

	if (pEdge == NULL)
	{
		pNodeStart=type == 0?m_pNode0:m_pNode1;
		TGraphArc* pEdge=this;
		while(true)
		{
			pEdge=pNodeStart->FindPreArc(pEdge);
			if (pEdge == NULL)
			{
				pMesh->SetStartNode(pNodeStart);
				break;
			}
			else
			{
				pMesh->InsertHead(pEdge);
				pNodeStart=pEdge->GetOtherNode(pNodeStart);
			}
		}
	}

	return pMesh;
}

TGraphNode* TGraphArc::GetOtherNode(TGraphNode* pNode) const
{
	if (pNode == m_pNode0)
	{
		return m_pNode1;
	}
	else
	{
		return m_pNode0;
	}
}