-- File:	GeomLib_DenominatorMultiplier.cdl
-- Created:	Tue May 13 10:36:30 1997
-- Author:	Stagiaire Francois DUMONT
--		<dum@brunox.paris1.matra-dtv.fr>
---Copyright:	 Matra Datavision 1997



class DenominatorMultiplier from GeomLib

	---Purpose: this class is used to  construct the BSpline curve
	--          from an Approximation ( ApproxAFunction from AdvApprox).
    	

uses

    BSplineSurface    from Geom,
    Array1OfReal      from TColStd
   
raises

    OutOfRange from Standard,
    ConstructionError from Standard
is

    Create( Surface           : BSplineSurface from Geom ;
    	    KnotVector        : Array1OfReal   from TColStd)
    returns DenominatorMultiplier from GeomLib
    raises
        ConstructionError from Standard;
       
     ---Purpose: if the surface is rational this will define the evaluator
     --          of a real function of 2 variables a(u,v) such that
     --          if we define a new surface by :
     --                       a(u,v) * N(u,v) 
     --          NewF(u,v) = ----------------
     --                       a(u,v) * D(u,v) 
    
    
    Value(me; UParameter : in Real from Standard ;
    	      VParameter : in Real from Standard) 

    returns Real from Standard
    raises
    	OutOfRange from Standard
    	---Purpose: Returns the value of 
    	--          a(UParameter,VParameter)=
    	--          
    	--            H0(UParameter)/Denominator(Umin,Vparameter)
    	--            
    	--            D Denominator(Umin,Vparameter)
        --          - ------------------------------[H1(u)]/(Denominator(Umin,Vparameter)^2)
        --            D U
        --            
        --          + H3(UParameter)/Denominator(Umax,Vparameter)
        --          
        --            D Denominator(Umax,Vparameter)
        --          - ------------------------------[H2(u)]/(Denominator(Umax,Vparameter)^2)
        --            D U
    is static;

    
fields
    
    mySurface          : BSplineSurface  from Geom  ;
    myKnotFlatVector   : Array1OfReal from TColStd  ;              
    

end MakeCurvefromApprox;