-- File:	TopClass_Intersection3d.cdl
-- Created:	Wed Mar 30 14:37:00 1994
-- Author:	Laurent BUCHARD
--		<lbr@fuegox>
---Copyright:	 Matra Datavision 1994





deferred class Intersection3d from TopClass 
    ---Purpose: Template class for the intersection algorithm required 
    --          by the 3D classifications. 
    --          
    --          (a intersection point near the origin of the line, ie. 
    --          at a distance less or equal than <tolerance>, will be 
    --          returned even if it has a negative parameter.)
    --          

uses 
    Lin               from gp,
    Pnt               from gp,
    Face              from TopoDS,
    State             from TopAbs,
    IntersectionPoint from IntCurveSurface
    
is

    Initialize;
    	---Purpose: Empty constructor.
    	          
    Perform(me: in out;  L    : Lin     from gp;
    	                 Prm  : Real    from Standard;
			 Tol  : Real    from Standard;
			 Face : Face    from TopoDS) 
	---Purpose: Perform the intersection between the 
	--          segment L(0) ... L(Prm) and the Face <Face>.
	--          
	--          Only the point with the smallest parameter on the 
	--          line is returned. 
	--          
	--          The Tolerance <Tol> is used to determine if the 
	--          first point of the segment is near the face. In 
	--          that case, the parameter of the intersection point 
	--          on the line can be a negative value (greater than -Tol).
    is deferred;
    
    
    IsDone(me)  
    	---Purpose: True is returned when the intersection have been computed.
    returns Boolean from Standard
    is deferred;
    
    
    HasAPoint(me) 
    	---Purpose: True is returned if a point has been found.
    returns Boolean from Standard
    is deferred;
    
	 
    Point(me) 
        ---Purpose: Returns the Intersection Point.
        --
        ---C++: return const & 
    returns IntersectionPoint from IntCurveSurface
    is deferred;

     
    State(me) 
    	---Purpose: Returns the state of the point on the face.
    	--          The values can be either TopAbs_IN 
    	--             ( the point is in the face)
    	--           or TopAbs_ON
    	--             ( the point is on a boudary of the face).
       
    returns State from TopAbs
    is deferred;
    
	---------------------- Loacl Geometry avec courbureS dans une 
	--                     direction et la direction normale     
end Intersection3d;