-- File:	MakeParabola.cdl
-- Created:	Mon Sep 28 11:49:29 1992
-- Author:	Remi GILET
--		<reg@sdsun2>
---Copyright:	 Matra Datavision 1992

class MakeParabola from GCE2d inherits Root from GCE2d

    	---Purpose :This class implements the following algorithms used to 
    	--          create Parabola from Geom2d.
    	--          * Create an Parabola from two apex  and the center.
    	--  Defines the parabola in the parameterization range  :
    	--  ]-infinite,+infinite[
    	--  The vertex of the parabola is the "Location" point of the 
    	--  local coordinate system "XAxis" of the parabola. 
    	--  The "XAxis" of the parabola is its axis of symmetry.
    	--  The "Xaxis" is oriented from the vertex of the parabola to the 
    	--  Focus of the parabola.
    	--  The equation of the parabola in the local coordinate system is
    	--  Y**2 = (2*P) * X
    	--  P is the distance between the focus and the directrix of the 
   	--  parabola called Parameter). 
    	--  The focal length F = P/2 is the distance between the vertex 
    	--  and the focus of the parabola.

uses Pnt2d    from gp,
     Parab2d  from gp,
     Ax2d     from gp,
     Ax22d    from gp,
     Parabola from Geom2d

raises NotDone from StdFail

is

Create (Prb : Parab2d from gp) returns MakeParabola;
    	--- Purpose : Creates a parabola from a non persistent one.

Create (Axis       : Ax22d from gp        ; 
    	Focal      : Real from Standard   ) returns MakeParabola;
    	--- Purpose : Creates a parabola with its local coordinate system and it's focal 
	--  length "Focal".
    	--  The "Location" point of "Axis" is the vertex of the parabola
    	--- Status is "NegativeFocusLength" if Focal < 0.0

Create (MirrorAxis : Ax2d    from gp      ; 
    	Focal      : Real    from Standard;
    	Sense      : Boolean from Standard) returns MakeParabola;
    	--- Purpose : Creates a parabola with its "MirrorAxis" and it's focal length "Focal".
    	--  MirrorAxis is the axis of symmetry of the curve, it is the
    	--  "XAxis". The "YAxis" is parallel to the directrix of the
    	--  parabola. The "Location" point of "MirrorAxis" is the vertex of the parabola
    	--- Status is "NegativeFocusLength" if Focal < 0.0

Create (D     : Ax22d from gp  ; 
    	F     : Pnt2d from gp  ) returns MakeParabola;
    	--- Purpose : Creates a parabola with the local coordinate system and the focus point.
    	--  The sense of parametrization is given by Sense.

Create (D     : Ax2d  from gp                        ; 
    	F     : Pnt2d from gp                        ;
    	Sense : Boolean from Standard = Standard_True) returns MakeParabola;
        --- Purpose :
        --  D is the directrix of the parabola and F the focus point.
        --  The symmetry axis "XAxis" of the parabola is normal to the
        --  directrix and pass through the focus point F, but its
        --  "Location" point is the vertex of the parabola.
        --  The "YAxis" of the parabola is parallel to D and its "Location"
        --  point is the vertex of the parabola.

Create(S1,O  : Pnt2d from gp) returns MakeParabola;
    	---Purpose: Make a parabola with focal point S1 and 
    	--          center O
    	--          The branch of the parabola returned will have <S1> as
    	--          focal point
    	-- The implicit orientation of the parabola is:
    	-- -   the same one as the parabola Prb,
    	-- -   the sense defined by the coordinate system Axis or the directrix D,
    	-- -   the trigonometric sense if Sense is not given or is true, or
    	-- -   the opposite sense if Sense is false.
    	-- Warning
    	-- The MakeParabola class does not prevent the
    	-- construction of a parabola with a null focal distance.
    	-- If an error occurs (that is, when IsDone returns
	-- false), the Status function returns:
    	-- -   gce_NullFocusLength if Focal is less than 0.0, or
    	-- -   gce_NullAxis if points S1 and O are coincident.
        
Value(me) returns Parabola from Geom2d
    raises NotDone
    is static;
    	---C++: return const&
    	---Purpose: Returns the constructed parabola.
    	-- Exceptions StdFail_NotDone if no parabola is constructed.
    
Operator(me) returns Parabola from Geom2d
    is static;
    	---C++: return const&
    	---C++: alias "Standard_EXPORT operator Handle_Geom2d_Parabola() const;"

fields

    TheParabola : Parabola from Geom2d;
    --The solution from Geom2d.
    
end MakeParabola;