-- File:	CurveTool.cdl
-- Created:	Tue Mar  3 18:07:18 1992
-- Author:	Herve LEGRAND
--		<hl@topsn3>
---Copyright:	 Matra Datavision 1992


deferred generic class CurveTool from LProp (Curve as any;
				             Pnt   as any;
                                             Vec   as any)

is

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

    D2   (myclass; C : Curve; U : Real; P : out Pnt; V1, V2 : out Vec);
    ---Purpose: Computes the point <P>, the first derivative <V1> and second
    --          derivative <V2> of parameter <U> on the curve <C>.
    
    D3   (myclass; C : Curve; U : Real; 
              P : out Pnt; V1, V2, V3 : out Vec);
    ---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) 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) returns Real;
     ---Purpose: returns the first parameter bound of the curve.
     --          
     
     LastParameter(myclass; C : Curve) returns Real;
     ---Purpose: returns the last parameter bound of the curve.
     --          FirstParameter must be less than LastParamenter.

end CurveTool;