-- File:	Conic.cdl
-- Created:	Tue Feb 11 16:07:09 1992
-- Author:	Laurent BUCHARD
--		<lbr@phobox>
---Copyright:	 Matra Datavision 1992


class Conic from IntAna2d

	---Purpose: Definition of a conic by its implicit quadaratic equation:
	--          A.X**2 + B.Y**2 + 2.C.X*Y + 2.D.X + 2.E.Y + F = 0.

uses XY        from gp,
     Ax2d      from gp,
     Circ2d    from gp,
     Elips2d   from gp,
     Parab2d   from gp,
     Hypr2d    from gp,
     Lin2d     from gp

is


    Create(C: Circ2d from gp)
    	
	returns Conic from IntAna2d;


    Create(C: Lin2d from gp)
    	
	returns Conic from IntAna2d;
	
	
    Create(C: Parab2d from gp)
    	
	returns Conic from IntAna2d;


    Create(C: Hypr2d from gp)
    	
	returns Conic from IntAna2d;


    Create(C: Elips2d from gp)
    	
	returns Conic from IntAna2d;
		

    Value(me; X,Y: Real)
    
    	---Purpose: value of the function F at the point X,Y.
    	
	returns Real
	
	is static;


    Grad(me; X,Y: Real)

    	---Purpose: returns the value of the gradient of F at the point X,Y.

    	returns XY from gp

    	is static;


    ValAndGrad(me; X,Y: Real; Val: out Real; Grd: out XY from gp)
    
	---Purpose: Returns the value of the function and its gradient at
	--          the point X,Y.
    
    	is static;


    Coefficients(me; A,B,C,D,E,F: out Real)

	---Purpose: returns the coefficients of the polynomial equation
	--          wich defines the conic:
	--          A.X**2 + B.Y**2 + 2.C.X*Y + 2.D.X + 2.E.Y + F = 0.
    
    	is static;


    NewCoefficients(me; A,B,C,D,E,F: in out Real ; Axis: Ax2d from gp)
	---Purpose: Returns the coefficients of the polynomial equation
	--          ( written in the natural coordinates system )
	--          A x x + B y y + 2 C x y + 2 D x + 2 E y + F
	--          in the local coordinates system defined by Axis
    
    	is static;
   
fields

a: Real;
b: Real;
c: Real;
d: Real;
e: Real;
f: Real;

end Conic;