-- File:	Extrema_GenLocateExtPS.cdl
-- Created:	Tue Jul 18 08:22:37 1995
-- Author:	Modelistation
--		<model@metrox>
---Copyright:	 Matra Datavision 1995


class   GenLocateExtPS from Extrema
					 
    	---Purpose: With a close point, it calculates the distance 
    	--          between a point and a surface.
    	--          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 GenLocateExtPS;

    Create (P: Pnt; S: Surface from Adaptor3d; U0,V0: Real; TolU,TolV: Real)
    	returns GenLocateExtPS
    	---Purpose: Calculates the distance with a close point.
    	--          The close point is defined by the parameter values
    	--          U0 and V0.
    	--          The function F(u,v)=distance(S(u,v),p) has an
    	--          extremun when gradient(F)=0. The algorithm searchs
    	--          a zero near the close point.
    	raises  DomainError;
	    	-- if U0,V0 are outside the definition ranges of the 
	    	-- surface.
    
    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;

    Point (me) returns POnSurf
    	---Purpose: Returns the point of the extremum distance.
    	raises  NotDone from StdFail
	    	-- if IsDone(me)=False.
    	is static;

fields
    myDone : Boolean;
    mySqDist: Real;
    myPoint: POnSurf from Extrema;

end GenLocateExtPS;