-- File:	 ParabolaToBSplineCurve.cdl
-- Created:	 Thu Oct 10 14:52:24 1991
-- Author:	 Jean Claude VAUTHIER
---Copyright:	 Matra Datavision 1991, 1992



class ParabolaToBSplineCurve   from Convert   inherits ConicToBSplineCurve

        --- Purpose :
        --  This algorithm converts a parabola into a non rational B-spline
        --  curve.
        --  The parabola is a Parab2d from package gp with the parametrization
        --  P (U) = Loc + F * (U*U * Xdir + 2 * U * Ydir) where Loc is the 
        --  apex of the parabola, Xdir is the normalized direction of the 
        --  symmetry axis of the parabola, Ydir is the normalized direction of
        --  the directrix and F is the focal length.
        --- KeyWords :
        --  Convert, Parabola, BSplineCurve, 2D .

uses Parab2d from gp

is


  Create (Prb : Parab2d; U1, U2 : Real)   returns ParabolaToBSplineCurve;
        --- Purpose : 
        --  The parabola Prb is limited between the parametric values U1, U2
        --  and the equivalent B-spline curve as the same orientation as the
        --  parabola Prb.


end ParabolaToBSplineCurve;