-- File:	Law_BSpFunc.cdl
-- Created:	Wed Nov 15 16:16:24 1995
-- Author:	Laurent BOURESCHE
--		<lbo@phylox>
---Copyright:	 Matra Datavision 1995


class BSpFunc from Law inherits Function from Law

	---Purpose: Law Function based on a BSpline curve 1d.  Package
	--          methods and classes are implemented in package Law
	--          to    construct  the  basis    curve with  several
	--          constraints.

uses
    BSpline from Law,
    Array1OfReal    from TColStd,
    Shape           from GeomAbs
      
raises OutOfRange from Standard   

is

    Create returns mutable BSpFunc from Law;
    
    Create(C  : BSpline from Law; First, Last: Real) 
    returns mutable BSpFunc from Law;
    
    Continuity(me) returns Shape from GeomAbs
    is redefined static;
    
    NbIntervals(me; S : Shape from GeomAbs) returns Integer
	---Purpose: Returns  the number  of  intervals for  continuity
	--          <S>. May be one if Continuity(me) >= <S>
    is redefined static;
    
    Intervals(me; T : in out Array1OfReal from TColStd; 
    	          S : Shape from GeomAbs)
	---Purpose: Stores in <T> the  parameters bounding the intervals
	--          of continuity <S>.
	--          
	--          The array must provide  enough room to  accomodate
	--          for the parameters. i.e. T.Length() > NbIntervals()
    raises
    	OutOfRange from Standard 
    is redefined static;

    Value(me: mutable; X: Real from Standard)
    returns Real from Standard;
	
    D1(me: mutable; X: Real from Standard; F,D: out Real from Standard); 
    
    D2(me: mutable; X: Real from Standard; 
       F,D, D2: out Real from Standard);
    

    Trim(me; PFirst, PLast, Tol :Real from Standard) returns Function
    
    ---Purpose:   Returns a  law equivalent of  <me>  between
	--        parameters <First>  and <Last>. <Tol>  is used  to
	--        test for 3d points confusion.
	--        It is usfule to determines the derivatives 
	--        in these values <First> and <Last> if 
        --        the Law is not Cn.          
    	is redefined static;    
    
    Bounds(me: mutable; PFirst,PLast: out Real from Standard);
    
    Curve(me) returns mutable BSpline from Law;

    SetCurve(me : mutable; 
             C  : BSpline from Law);

fields
    curv : BSpline from Law; -- is protected;To force Curve() and 
                             -- SetCurve() to  be  used.  
    first  : Real;
    last   : Real;
end BSpFunc;