-- File:	FaceExplorer.cdl
-- Created:	Tue Nov 17 16:39:19 1992
-- Author:	Remi LEQUETTE
--		<rle@phylox>
---Copyright:	 Matra Datavision 1992


deferred generic class FaceExplorer from TopClass 
     (TheEdge as any)

	---Purpose: Describe an exploration of a 2D face  suitable for
	--          classification.

uses
    Orientation from TopAbs,
    Pnt2d from gp,
    Lin2d from gp

is
    Reject(me;  P : Pnt2d from gp) returns Boolean
	---Purpose: Should  return  True  if the  point  is  outside a
	--          bounding volume of the face.
    is deferred;
    
    Segment(me;  P :  Pnt2d from gp;
    	         L : out Lin2d from gp; Par : out  Real)
	 ---Purpose: Returns  in <L>, <Par>  a segment having at least
	 --          one  intersection  with  the   face  boundary  to
	 --          compute  intersections. 
    is deferred;
    
    InitWires(me : in out)
	---Purpose: Starts an exploration of the wires.
    is deferred;
    
    MoreWires(me) returns Boolean
	---Purpose: Returns True if there is  a current wire.
	---C++: inline
    is deferred;
    	
    NextWire(me : in out)
	---Purpose: Sets the explorer  to the  next  wire and  returns
	--          False if there are no more wires.
    is deferred;
    
    RejectWire(me; L :  Lin2d from gp; Par : Real) returns Boolean
	---Purpose: Returns True  if the wire  bounding volume does not
	--          intersect the segment.
    is deferred;
    
    InitEdges(me : in out)
	---Purpose: Starts an exploration of the  edges of the current
	--          wire.
    is deferred;
    
    MoreEdges(me) returns Boolean
	---Purpose: Returns True if there is a current edge.
	---C++: inline
    is deferred;
    
    NextEdge(me  : in out)
	---Purpose: Sets the explorer  to the  next  wire and  returns
	--          False if there are no more wires.
    is deferred;

    RejectEdge(me; L :  Lin2d from gp; Par : Real) returns Boolean
	---Purpose: Returns True  if the edge  bounding volume does not
	--          intersect the segment.
    is deferred;
    
    CurrentEdge(me; E : out TheEdge; Or : out Orientation from TopAbs)
	---Purpose: Curent edge in current wire and its orientation
    is deferred;
    
end FaceExplorer;