1 // Created on: 1993-03-24
3 // Copyright (c) 1993-1999 Matra Datavision
4 // Copyright (c) 1999-2014 OPEN CASCADE SAS
6 // This file is part of Open CASCADE Technology software library.
8 // This library is free software; you can redistribute it and/or modify it under
9 // the terms of the GNU Lesser General Public License version 2.1 as published
10 // by the Free Software Foundation, with special exception defined in the file
11 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
12 // distribution for complete text of the license and disclaimer of any warranty.
14 // Alternatively, this file may be used under the terms of Open CASCADE
15 // commercial license or contractual agreement.
17 #ifndef _Geom2d_Conic_HeaderFile
18 #define _Geom2d_Conic_HeaderFile
20 #include <Standard.hxx>
21 #include <Standard_Type.hxx>
23 #include <gp_Ax22d.hxx>
24 #include <Geom2d_Curve.hxx>
25 #include <Standard_Real.hxx>
26 #include <GeomAbs_Shape.hxx>
27 #include <Standard_Boolean.hxx>
28 #include <Standard_Integer.hxx>
29 class Standard_ConstructionError;
30 class Standard_DomainError;
37 DEFINE_STANDARD_HANDLE(Geom2d_Conic, Geom2d_Curve)
39 //! The abstract class Conic describes the common
40 //! behavior of conic curves in 2D space and, in
41 //! particular, their general characteristics. The Geom2d
42 //! package provides four specific classes of conics:
43 //! Geom2d_Circle, Geom2d_Ellipse,
44 //! Geom2d_Hyperbola and Geom2d_Parabola.
45 //! A conic is positioned in the plane with a coordinate
46 //! system (gp_Ax22d object), where the origin is the
47 //! center of the conic (or the apex in case of a parabola).
48 //! This coordinate system is the local coordinate
49 //! system of the conic. It gives the conic an explicit
50 //! orientation, determining the direction in which the
51 //! parameter increases along the conic. The "X Axis" of
52 //! the local coordinate system also defines the origin of
53 //! the parameter of the conic.
54 class Geom2d_Conic : public Geom2d_Curve
60 //! Modifies this conic, redefining its local coordinate system
61 //! partially, by assigning P as its origin
62 Standard_EXPORT void SetAxis (const gp_Ax22d& A);
64 Standard_EXPORT void SetXAxis (const gp_Ax2d& A);
66 //! Assigns the origin and unit vector of axis A to the
67 //! origin of the local coordinate system of this conic and either:
68 //! - its "X Direction", or
69 //! - its "Y Direction".
70 //! The other unit vector of the local coordinate system
71 //! of this conic is recomputed normal to A, without
72 //! changing the orientation of the local coordinate
73 //! system (right-handed or left-handed).
74 Standard_EXPORT void SetYAxis (const gp_Ax2d& A);
76 //! Modifies this conic, redefining its local coordinate
77 //! system fully, by assigning A as this coordinate system.
78 Standard_EXPORT void SetLocation (const gp_Pnt2d& P);
81 //! Returns the "XAxis" of the conic.
82 //! This axis defines the origin of parametrization of the conic.
83 //! This axis and the "Yaxis" define the local coordinate system
85 //! -C++: return const&
86 Standard_EXPORT gp_Ax2d XAxis() const;
89 //! Returns the "YAxis" of the conic.
90 //! The "YAxis" is perpendicular to the "Xaxis".
91 Standard_EXPORT gp_Ax2d YAxis() const;
94 //! returns the eccentricity value of the conic e.
95 //! e = 0 for a circle
96 //! 0 < e < 1 for an ellipse (e = 0 if MajorRadius = MinorRadius)
97 //! e > 1 for a hyperbola
98 //! e = 1 for a parabola
99 Standard_EXPORT virtual Standard_Real Eccentricity() const = 0;
102 //! Returns the location point of the conic.
103 //! For the circle, the ellipse and the hyperbola it is the center of
104 //! the conic. For the parabola it is the vertex of the parabola.
105 Standard_EXPORT gp_Pnt2d Location() const;
108 //! Returns the local coordinates system of the conic.
109 Standard_EXPORT const gp_Ax22d& Position() const;
112 //! Reverses the direction of parameterization of <me>.
113 //! The local coordinate system of the conic is modified.
114 Standard_EXPORT void Reverse();
116 //! Returns the parameter on the reversed curve for
117 //! the point of parameter U on <me>.
118 Standard_EXPORT virtual Standard_Real ReversedParameter (const Standard_Real U) const = 0;
120 //! Returns GeomAbs_CN which is the global continuity of any conic.
121 Standard_EXPORT GeomAbs_Shape Continuity() const;
124 //! Returns True, the order of continuity of a conic is infinite.
125 Standard_EXPORT Standard_Boolean IsCN (const Standard_Integer N) const;
130 DEFINE_STANDARD_RTTI(Geom2d_Conic,Geom2d_Curve)
151 #endif // _Geom2d_Conic_HeaderFile