-- File:	Contap_SurfProps.cdl
-- Created:	Fri Feb 24 15:30:15 1995
-- Author:	Jacques GOUSSARD
--		<jag@topsn2>
---Copyright:	 Matra Datavision 1995


generic class SurfProps from Contap 
    (TheSurface     as any;
     TheSurfaceTool as any) -- as SurfaceTool from Contap

	---Purpose: Internal tool used  to compute the  normal and its
	--          derivatives. 

uses Pnt from gp,
     Vec from gp

is

    Normale(myclass; S: TheSurface; U,V: Real from Standard;
                     P: out Pnt from gp;
		     N: out Vec from gp);

	---Purpose: Computes  the point <P>, and  normal vector <N> on
	--          <S> at parameters U,V.



    DerivAndNorm(myclass; S: TheSurface; U,V: Real from Standard;
                          P      : out Pnt from gp;
			  d1u,d1v: out Vec from gp;
		          N      : out Vec from gp);

	---Purpose: Computes  the point <P>, and  normal vector <N> on
	--          <S> at parameters U,V.



    NormAndDn(myclass; S: TheSurface; U,V: Real from Standard;
                       P        : out Pnt from gp;
		       N,Dnu,Dnv: out Vec from gp);

	---Purpose: Computes the point <P>, normal vector <N>, and its
	--          derivatives <Dnu> and <Dnv> on <S> at parameters U,V.


end SurfProps;