-- File:	Extrema_GenExtCC.cdl
-- Created:	Tue Jul 18 17:41:35 1995
-- Author:	Modelistation
--		<model@metrox>
---Copyright:	 Matra Datavision 1995



generic class   GenExtCC from Extrema 
(Curve1    as any;
 Tool1     as any;   -- as ToolCurve(Curve1)
 Curve2    as any;
 Tool2     as any;   -- as ToolCurve(Curve2)
 Cache     as Transient from Standard;   -- CurveCache from Extrema
 ArrayOfPnt as Transient from Standard; -- as returned by Extrema_CurveCache::Points()
 POnC      as any;
 Pnt       as any;
 Vec       as any)

	---Purpose: It calculates all the distance between two curves.
	--          These distances can be maximum or minimum.

raises  InfiniteSolutions from StdFail,
    	NotDone           from StdFail,
    	OutOfRange        from Standard
	
private class CCF instantiates FuncExtCC from Extrema (Curve1, Tool1,  
    	    	    	    	    	    	       Curve2, Tool2,  
    	    	    	    	    	    	       POnC, Pnt, Vec);

is

    Create returns GenExtCC;
    	---Purpose: Calculates all the distances as above
    	--          between Uinf and Usup for C1 and  between Vinf and Vsup 
    	--          for C2.

    Create (C1: Curve1; C2: Curve2; NbU,NbV: Integer; TolU,TolV: Real) returns GenExtCC;
      	---Purpose: It calculates all the distances.
        --          The function F(u,v)=distance(C1(u),C2(v)) has an 
        --          extremum when gradient(f)=0. The algorithm searchs
        --          all the zeros.
      	--          NbU,NbV are used to locate the close points to
      	--          find the zeros. They must be great enough such that
      	--          if there is N extrema, there will be N extrema 
      	--          between the segment and the grid.
      	--          TolU and TolV are used to determinethe conditions
      	--          to stop the iterations; at the iteration number n:
      	--           (Un - Un-1) < TolU and (Vn - Vn-1) < TolV .

    Create (C1: Curve1; C2: Curve2; Uinf, Usup, Vinf, Vsup: Real;
    	    NbU,NbV: Integer; TolU,TolV: Real) returns GenExtCC;
    	---Purpose: Calculates all the distances as above
    	--          between Uinf and Usup for C1 and  between Vinf and Vsup 
    	--          for C2.

    SetCurveCache (me: in out; theRank: Integer; theCache: Cache);
        ---Purpose: 

    SetTolerance (me: in out; Tol: Real);
        ---Purpose:

    Perform(me: in out) is static;
    	---Purpose: Performs calculations.


    IsDone (me) returns Boolean
    	---Purpose: Returns True if the distances are found.
    	is static;

    NbExt (me) returns Integer
    	---Purpose: Returns the number of extremum distances.
    	raises  NotDone from StdFail,
	    	-- if IsDone(me)=False.
    	    	InfiniteSolutions from StdFail
		-- if IsParallel(me)= True.
    	is static;

    SquareDistance (me; N: Integer =1) returns Real
    	---Purpose: Returns the value of the Nth square extremum distance.
    	raises  NotDone from StdFail,
	    	-- if IsDone(me)=False.
    	    	InfiniteSolutions from StdFail,
		-- if IsParallel(me)= True and N > 1.
    	    	OutOfRange
		-- if N < 1 or N > NbExt(me)
    	is static;

    Points (me; N: Integer; P1,P2: out POnC)
    	---Purpose: Returns the points of the Nth extremum distance.
    	--          P1 is on the first curve, P2 on the second one.
    	raises  NotDone from StdFail,
	    	-- if IsDone(me)=False.
    	    	InfiniteSolutions from StdFail,
		-- if IsParallel(me)= True.
    	    	OutOfRange
		-- if N < 1 or N > NbExt(me)
    	is static;

fields
    myF    : CCF from Extrema;
    myDone : Boolean;
    myCache: Cache [2];

end GenExtCC;