enum EdgeLabel{ UndoneEdge, MovedEdge, FixedEdge, DividedEdge };

class Edge{
public:
	int         birthStage;
	class Face *face[2];
	Vertex     *vertex[2];
	EdgeLabel   label;
	Vertex     *newVertex;
	Edge       *parent;
	Edge       *children[2];

	Edge(){ birthStage = 0; face[0] = face[1] = NULL; vertex[0] = vertex[1] = newVertex = NULL; label = FixedEdge; parent = children[0] = children[1] = NULL; }
	Vertex *primaryVertex( Face &face ); // face.h

	double distance( Vector &p0, Vector &p1 ){
		Line e( vertex[0]->position, vertex[1]->position );
		double d0 = e.distance( p0 );
		double d1 = e.distance( p1);
		return d0 > d1 ? d0 : d1;
	}

	//renew
	Edge(Face * &children0, Face * &children1, int birthStage ){ this->birthStage = birthStage; face[0] = children0; face[1] = children1; vertex[0] = vertex[1] = newVertex = NULL; label = FixedEdge; parent = children[0] = children[1] = NULL; }

	Edge( Edge &parentEdge, int birthStage  ){
		this->birthStage = birthStage;
		face[0]   = parentEdge.face[0];
		face[1]   = parentEdge.face[1];
		vertex[0] = vertex[1] = newVertex = NULL;
		parent    = &parentEdge;
		children[0] = children[1] = NULL;
	}

	Face *connectFace( Face &face ){ return &face == this->face[0] ? this->face[1] : this->face[0]; }

	void renew( int birthStage, Fold &fold ){
		if( label != UndoneEdge ) return;
		if( vertex[0]->label == Moved && vertex[1]->label == Fixed || vertex[1]->label == Moved && vertex[0]->label == Fixed ){
			label = DividedEdge;
			children[0] = new Edge( *this, birthStage  );
			children[1] = new Edge( *this, birthStage );
			newVertex   = new Vertex( *vertex[0], *vertex[1], birthStage, fold );
			children[0]->vertex[0] = vertex[0];
			children[0]->vertex[1] = newVertex;
			children[1]->vertex[0] = newVertex;
			children[1]->vertex[1] = vertex[1];
			children[0]->label = vertex[0]->label == Moved ? MovedEdge : FixedEdge;
			children[1]->label = vertex[1]->label == Moved ? MovedEdge : FixedEdge;
		}else if( vertex[0]->label == Moved || vertex[1]->label == Moved ){
			label = MovedEdge;
		}else{
			label = FixedEdge;
		}
	}

	void renewPointer(); // face.h

	//reset
	void resetPointer( int deleteStage ); // face.h
	~Edge(){ if( newVertex != NULL ) delete newVertex; }

	void reset( int deleteStage ){
		if( vertex[0]->child != NULL ){ delete vertex[0]->child; vertex[0]->child = NULL; }
		if( vertex[1]->child != NULL ){ delete vertex[1]->child; vertex[1]->child = NULL; }
		if( children[0] != NULL ){ delete children[0]; children[0] = NULL; }
		if( children[1] != NULL ){ delete children[1]; children[1] = NULL; }
		if( newVertex   != NULL ){ delete newVertex; newVertex = NULL; }
	}

	void print(){
		printf( "birthStage %d\n", birthStage );
		switch( label ){
			case MovedEdge:   printf( "MovedEdge\n" ); break;
			case FixedEdge:   printf( "FixedEdge\n" ); break;
			case DividedEdge: printf( "DividedEdge\n" ); break;
			case UndoneEdge:  printf( "UndoneEdge\n" ); break;
		}
		if( face[0] == NULL ) printf( "Face0 None\n" ); else printf( "Face0 Exist\n" );
		if( face[1] == NULL ) printf( "Face1 None\n" ); else printf( "Face1 Exist\n" );
		for( int i=0; i<2; i++ ){
			switch( vertex[i]->label ){
				case Moved:  printf( "MovedVertex " ); break;
				case Fixed:  printf( "FixedVertex " ); break;
				case OnAxis: printf( "OnAxis " ); break;
			}
			vertex[i]->position.print();
		}
	}
};