-- File:	Extrema_GenLocateExtSS.cdl
-- Created:	Mon Jan 22 10:33:25 1996
-- Author:	Laurent PAINNOT
--		<lpa@nonox>
---Copyright:	 Matra Datavision 1996


class   GenLocateExtSS from Extrema
					 
    	---Purpose: With two close points it calculates the distance 
    	--          between two surfaces.
    	--          This distance can be a minimum or a maximum.

uses    POnSurf from Extrema,
        Pnt     from gp,
	Surface from Adaptor3d
 
raises  DomainError from Standard,
    	NotDone     from StdFail


is
    Create returns GenLocateExtSS;

    Create (S1, S2: Surface from Adaptor3d; U1,V1, U2,V2: Real; Tol1,Tol2: Real)
    	returns GenLocateExtSS
    	---Purpose: Calculates the distance with two close points.
    	--          The close points are defined by the parameter values
    	--          (U1,V1) for S1 and (U2,V2) for S2.
    	--          The function F(u1,v1,u2,v2)=distance(S1(u1,v1),S2(u2,v2)) 
    	--          has an extremun when gradient(F)=0. The algorithm searchs
    	--          a zero near the close points.
    	raises  DomainError;
	    	-- if U1,V1,U2,V2 are outside the definition ranges of the 
	    	-- surfaces.
    
    Perform(me: in out; S1, S2: Surface from Adaptor3d; 
    	    U1,V1, U2,V2: Real; Tol1,Tol2: Real) 
    is static;
    
    
    IsDone (me) returns Boolean
    	---Purpose: Returns True if the distance is found.
    	is static;

    SquareDistance (me) returns Real
    	---Purpose: Returns the value of the extremum square distance.
    	raises  NotDone from StdFail
	    	-- if IsDone(me)=False.
    	is static;

    PointOnS1 (me) returns POnSurf
    	---Purpose: Returns the point of the extremum distance on S1.
    	---C++: return const&
    	raises  NotDone from StdFail
	    	-- if IsDone(me)=False.
    	is static;


    PointOnS2 (me) returns POnSurf
    	---Purpose: Returns the point of the extremum distance on S2.
    	---C++: return const&
    	raises  NotDone from StdFail
	    	-- if IsDone(me)=False.
    	is static;

fields
    myDone  : Boolean;
    mySqDist: Real;
    myPoint1: POnSurf from Extrema;
    myPoint2: POnSurf from Extrema;

end GenLocateExtSS;