path: root/src/gp/gp_Elips.cdl

---Copyright:   Matra Datavision 1991, 1992



class Elips   from gp  inherits Storable
        --- Purpose :
        --      Describes an ellipse in 3D space.
        -- An ellipse is defined by its major and minor radii and
        -- positioned in space with a coordinate system (a gp_Ax2 object) as follows:
        -- -   the origin of the coordinate system is the center of the ellipse,
        -- -   its "X Direction" defines the major axis of the ellipse, and
        -- - its "Y Direction" defines the minor axis of the ellipse.
        -- Together, the origin, "X Direction" and "Y Direction" of
        -- this coordinate system define the plane of the ellipse.
        -- This coordinate system is the "local coordinate system"
        -- of the ellipse. In this coordinate system, the equation of
        -- the ellipse is:
        -- X*X / (MajorRadius**2) + Y*Y / (MinorRadius**2) = 1.0
        -- The "main Direction" of the local coordinate system gives
        -- the normal vector to the plane of the ellipse. This vector
        -- gives an implicit orientation to the ellipse (definition of the
        -- trigonometric sense). We refer to the "main Axis" of the
        -- local coordinate system as the "Axis" of the ellipse.
        -- See Also
        -- gce_MakeElips which provides functions for more
        -- complex ellipse constructions
        -- Geom_Ellipse which provides additional functions for
        -- constructing ellipses and works, in particular, with the
        -- parametric equations of ellipses

uses  Ax1  from gp,
      Ax2  from gp,
      Pnt  from gp,
      Trsf from gp,
      Vec  from gp

raises ConstructionError from Standard

is


  Create  returns Elips;
        ---C++:inline
        --- Purpose : Creates an indefinite ellipse.
 

  Create (A2 : Ax2; MajorRadius, MinorRadius : Real)   returns Elips
        ---C++: inline
	--- Purpose :
        --  The major radius of the ellipse is on the "XAxis" and the
        --  minor radius is on the "YAxis" of the ellipse. The "XAxis"
        --  is defined with the "XDirection" of A2 and the "YAxis" is
        --  defined with the "YDirection" of A2.
        -- Warnings :
        --  It is not forbidden to create an ellipse with MajorRadius =
        --  MinorRadius.  
        --  Raises ConstructionError if MajorRadius < MinorRadius or MinorRadius < 0. 
     raises ConstructionError;
	 


  SetAxis (me : in out; A1 : Ax1)
        ---C++:inline
        --- Purpose : 
        --  Changes the axis normal to the plane of the ellipse.
        --  It modifies the definition of this plane.
        --  The "XAxis" and the "YAxis" are recomputed.
        -- The local coordinate system is redefined so that:
        -- -   its origin and "main Direction" become those of the
        --   axis A1 (the "X Direction" and "Y Direction" are then
        --   recomputed in the same way as for any gp_Ax2), or
        --  Raises ConstructionError if the direction of A1
        -- is parallel to the direction of the "XAxis" of the ellipse.
    raises ConstructionError
      
     is static;


  SetLocation (me : in out; P : Pnt)   is static;
        ---C++: inline
        --- Purpose :Modifies this ellipse, by redefining its local coordinate
        -- so that its origin becomes P.


  SetMajorRadius (me : in out; MajorRadius : Real)
        ---C++: inline
        --- Purpose :
        --  The major radius of the ellipse is on the "XAxis" (major axis)
        --  of the ellipse.  
        --  Raises ConstructionError if MajorRadius < MinorRadius.
     raises ConstructionError
     is static;


  SetMinorRadius (me : in out; MinorRadius : Real)
        ---C++: inline
        --- Purpose :
        --  The minor radius of the ellipse is on the "YAxis" (minor axis)
        --  of the ellipse.
        --  Raises ConstructionError if MinorRadius > MajorRadius or MinorRadius < 0.
     raises ConstructionError
	
     is static;


  SetPosition (me : in out; A2 : Ax2)   is static;
        ---C++: inline
        --- Purpose : Modifies this ellipse, by redefining its local coordinate
        -- so that it becomes A2e.


  Area (me)   returns Real   is static;
 	--- Purpose : Computes the area of the Ellipse.
        ---C++: inline


  Axis (me)  returns Ax1   is static;
        ---C++: inline
        --- Purpose:
        --  Computes the axis normal to the plane of the ellipse.
    	---C++: return const&


  Directrix1 (me)  returns Ax1
        ---C++:inline
        --- Purpose : Computes the first or second directrix of this ellipse.
        -- These are the lines, in the plane of the ellipse, normal to
        -- the major axis, at a distance equal to
        -- MajorRadius/e from the center of the ellipse, where
        -- e is the eccentricity of the ellipse.
        -- The first directrix (Directrix1) is on the positive side of
        -- the major axis. The second directrix (Directrix2) is on
        -- the negative side.
        -- The directrix is returned as an axis (gp_Ax1 object), the
        -- origin of which is situated on the "X Axis" of the local
        -- coordinate system of this ellipse.
        -- Exceptions
        -- Standard_ConstructionError if the eccentricity is null
        -- (the ellipse has degenerated into a circle).

     raises ConstructionError
	
     is static;


  Directrix2 (me)    returns Ax1
        ---C++:inline
        --- Purpose :
        --  This line is obtained by the symmetrical transformation 
        --  of "Directrix1" with respect to the "YAxis" of the ellipse.
        -- Exceptions
        -- Standard_ConstructionError if the eccentricity is null
        -- (the ellipse has degenerated into a circle).
    raises ConstructionError
	
     is static;


  Eccentricity (me)   returns Real
        ---C++:inline
	--- Purpose :
	--  Returns the eccentricity of the ellipse  between 0.0 and 1.0
	--  If f is the distance between the center of the ellipse and
	--  the Focus1 then the eccentricity e = f / MajorRadius.   
        --   Raises ConstructionError if MajorRadius = 0.0
     raises ConstructionError
     is static;


  Focal (me)   returns Real   is static;
        ---C++:inline
	--- Purpose :
	--  Computes the focal distance. It is the distance between the
        --  two focus focus1 and focus2 of the ellipse.


  Focus1( me)   returns Pnt   is static;
        ---C++:inline
	--- Purpose :
	--  Returns the first focus of the ellipse. This focus is on the
        --  positive side of the "XAxis" of the ellipse.


  Focus2 (me)  returns Pnt  is static;
        ---C++:inline
        --- Purpose :
	--  Returns the second focus of the ellipse. This focus is on the
        --  negative side of the "XAxis" of the ellipse.


  Location (me)  returns Pnt   is static;
        ---C++:inline
        --- Purpose :
        --  Returns the center of the ellipse. It is the "Location"
        --  point of the coordinate system of the ellipse.
    	---C++: return const&


  MajorRadius (me)   returns Real   is static;
	--- Purpose : Returns the major radius of the ellipse.
        ---C++: inline


  MinorRadius (me)   returns Real  is static;
	--- Purpose : Returns the minor radius of the ellipse.
        ---C++: inline


  Parameter (me)   returns Real   is static;
        ---C++: inline
        --- Purpose :
        --  Returns p = (1 - e * e) * MajorRadius where e is the eccentricity 
        --  of the ellipse.
	--  Returns 0 if MajorRadius = 0
  

  Position (me)    returns Ax2    is static;
        --- Purpose : Returns the coordinate system of the ellipse.
        ---C++: inline
        ---C++: return const&
 

  XAxis (me)  returns Ax1   is static;
        ---C++:inline
        --- Purpose :
        --  Returns the "XAxis" of the ellipse whose origin
        -- is the center of this ellipse. It is the major axis of the
        --  ellipse.


  YAxis (me)  returns Ax1   is static;
        ---C++:inline
        --- Purpose :
        --  Returns the "YAxis" of the ellipse whose unit vector is the "X Direction" or the "Y Direction"
        --  of the local coordinate system of this ellipse.
        -- This is the minor axis of the ellipse.


  Mirror (me : in out; P : Pnt)  
	is static;

  Mirrored (me; P : Pnt)   returns Elips  is static;


        --- Purpose :
        --  Performs the symmetrical transformation of an ellipse with 
        --  respect to the point P which is the center of the symmetry.


  Mirror (me : in out; A1 : Ax1)
           is static;

  Mirrored (me; A1 : Ax1)   returns Elips  is static;

        --- Purpose :
        --  Performs the symmetrical transformation of an ellipse with
        --  respect to an axis placement which is the axis of the symmetry.

     
  Mirror (me : in out; A2 : Ax2) 
         is static;

  Mirrored (me; A2 : Ax2)  returns Elips  is static;

   --- Purpose :
        --  Performs the symmetrical transformation of an ellipse with
        --  respect to a plane. The axis placement A2 locates the plane
        --  of the symmetry (Location, XDirection, YDirection).

  Rotate (me : in out; A1 : Ax1; Ang : Real)
        ---C++: inline
         is static;

  Rotated (me; A1 : Ax1; Ang : Real)  returns Elips  is static;
        ---C++: inline
        --- Purpose :
        --  Rotates an ellipse. A1 is the axis of the rotation.
        --  Ang is the angular value of the rotation in radians.


   
       
  Scale (me : in out; P : Pnt; S : Real)          is static;
        ---C++: inline

  Scaled (me; P : Pnt; S : Real)   returns Elips  is static;
        ---C++: inline
        --- Purpose :
        --  Scales an ellipse. S is the scaling value.

     

  Transform (me : in out; T : Trsf)           is static;
        ---C++: inline

  Transformed (me; T : Trsf)   returns Elips  is static;
        ---C++: inline
        --- Purpose :
        --  Transforms an ellipse with the transformation T from class Trsf.



  Translate (me : in out; V : Vec)
        ---C++: inline
          is static;

  Translated (me; V : Vec)  returns Elips   is static;
        ---C++: inline
        --- Purpose :
        --  Translates an ellipse in the direction of the vector V.
        --  The magnitude of the translation is the vector's magnitude.

     

  Translate (me : in out; P1, P2 : Pnt) 
        ---C++: inline
         is static;

  Translated (me; P1, P2 : Pnt)   returns Elips  is static;
        ---C++: inline
        --- Purpose :
        --  Translates an ellipse from the point P1 to the point P2. 

fields

     pos         : Ax2;
     majorRadius : Real;
     minorRadius : Real;

end;