INTERFACE QuadEdge;

IMPORT Octf;

TYPE
  Pair = Octf.Pair;
  Arc = RECORD pair : Pair; d: Octf.DBit END;  (* Definition the scheme of
                                                representation the Edges in
                                                function the FacetEdge
                                                structure *)

(* ================= Function's QuadEdge ========= *)

PROCEDURE Flip(s : Arc) : Arc;

PROCEDURE Sym(s : Arc): Arc;

PROCEDURE Sym_(s : Arc): Arc;

PROCEDURE Onext(s : Arc): Arc;

PROCEDURE Oprev(s : Arc): Arc;

PROCEDURE Dual(s : Arc): Arc;

PROCEDURE Rot(s : Arc): Arc;

PROCEDURE Lnext(s : Arc): Arc;

PROCEDURE Rprev(s : Arc): Arc;

(* =================== Operator's QuadEdge ========== *)

PROCEDURE MakeEdge() : Arc;

PROCEDURE MakeLoop() : Arc;

PROCEDURE Splice(a,b : Arc);

PROCEDURE Splice_(a,b : Arc);

END QuadEdge.