-- File:	Curve2dTool.cdl
-- Created:	Thu Mar 26 13:38:57 1992
-- Author:	Herve LEGRAND
--		<hl@topsn3>
---Copyright:	 Matra Datavision 1992

class Curve2dTool from Geom2dLProp

uses Vec2d   from gp,
     Pnt2d   from gp,     
     Dir2d   from gp,
     Curve from Geom2d

is

    Value(myclass; C : Curve from Geom2d; U : Real;
    	           P : out Pnt2d);
    ---Purpose: Computes the point <P> of parameter <U> on the curve <C>.
     	
    D1   (myclass; C : Curve from Geom2d; U : Real; 
                   P : out Pnt2d; V1 : out Vec2d);
    ---Purpose: Computes the point <P> and first derivative <V1> of 
    --          parameter <U> on the curve <C>.

    D2   (myclass; C : Curve from Geom2d; U : Real;
                   P : out Pnt2d; V1, V2 : out Vec2d);
    ---Purpose: Computes the point <P>, the first derivative <V1> and second
    --          derivative <V2> of parameter <U> on the curve <C>.
    
    D3   (myclass; C : Curve from Geom2d; U : Real; 
              P : out Pnt2d; V1, V2, V3 : out Vec2d);
    ---Purpose: Computes the point <P>, the first derivative <V1>, the 
    --          second derivative <V2> and third derivative <V3> of 
    --          parameter <U> on the curve <C>.

     Continuity(myclass; C : Curve from Geom2d) returns Integer;
     ---Purpose: returns the order of continuity of the curve <C>.
     --          returns 1 : first derivative only is computable
     --          returns 2 : first and second derivative only are computable.
     --          returns 3 : first, second and third are computable.

     FirstParameter(myclass; C : Curve from Geom2d) returns Real;
     ---Purpose: returns the first parameter bound of the curve.
     --          
     
     LastParameter(myclass; C : Curve from Geom2d) returns Real;
     ---Purpose: returns the last parameter bound of the curve.
     --          FirstParameter must be less than LastParameter.

end Curve2dTool;