enum VertexLabel{ NotPicked, PickedCandidate, MovedCandidate, OnAxis, Fixed, Moved };
enum VertexLabels{ AllMoved, AllFixed, MovedAndFixed };

class Vertex{
public:
	int         birthStage;
	Vector      position;
	Vector2D    texcoord;
	VertexLabel label;
	Vertex     *parent;
	Vertex     *child;

	Vertex( Vector &position, Vector2D &texcoord ){ this->birthStage = 0; this->position = position; this->texcoord = texcoord; parent = child = NULL; }
	void labelPickedCandidate( Vector &position, double margin=0.01){ label = position.distance( this->position ) < margin ? PickedCandidate : NotPicked; }

	VertexLabel setLabel( Fold &fold, double margin=0.01 ){ return label = fold.vertexLabel( position, margin ); }

	Vertex( Vertex &vertex1, Vertex &vertex2, int birthStage, Fold &fold ){
		this->birthStage = birthStage;
		position = fold.newVertexPosition( vertex1.position, vertex2.position );
		double m = vertex1.position.distance( position );
		double n = vertex2.position.distance( position );
		texcoord.divide( vertex1.texcoord, vertex2.texcoord, m, n );
		parent = child = NULL;
	}

	Vertex( Vertex &parentVertex, int birthStage, Fold &fold ){
		this->birthStage = birthStage;
		position = fold.rotateVertexPosition( parentVertex.position );
		texcoord = parentVertex.texcoord;
		parent = &parentVertex;
		child  = NULL;
	}

	void renew( int birthStage, Fold &fold ){
		if( label == MovedCandidate ){
			label = Moved;
			child = new Vertex( *this, birthStage, fold );
		}
	}

	void glTexCoord(){ texcoord.glTexCoord(); }
	void glVertex(){ position.glVertex(); }
	void glTranslate(){ position.glTranslate(); }
};

// ------------------------- other classes member functions -----------------------------------------
Vector Fold::pickedVertexPosition(){ return vertex->position; }

enum VertexLabel Fold::vertexLabel( Vector &position, double margin ){
	Vector v = position - boundary.passage;
	double distance = boundary.normal * v;
	if( fabs( distance ) < margin ) return OnAxis;
	else if( distance < 0 )         return MovedCandidate;
	else                            return Fixed;
}

void Fold::modify( double position ){
	destination = destination2;
	type        = type2;
	boundary    = boundary2;
	axis        = axis2;
	angle       = angle2;
	if( position < 1.0 ){
		if( type == TuckIn ){
			destination.divide( vertex->position, destination, position, 1.0-position );
		}else{
			if( type == FoldUp ) type = BendUp;
			else if( type == FoldDown ) type = BendDown;
			angle *= position;
			destination = this->rotateVertexPosition( vertex->position );
		}
	}
}