include/opencascade/GeomEval_ParaboloidSurface.hxx

0001 // Copyright (c) 2025 OPEN CASCADE SAS
0002 //
0003 // This file is part of Open CASCADE Technology software library.
0004 //
0005 // This library is free software; you can redistribute it and/or modify it under
0006 // the terms of the GNU Lesser General Public License version 2.1 as published
0007 // by the Free Software Foundation, with special exception defined in the file
0008 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
0009 // distribution for complete text of the license and disclaimer of any warranty.
0010 //
0011 // Alternatively, this file may be used under the terms of Open CASCADE
0012 // commercial license or contractual agreement.
0013
0014 #ifndef _GeomEval_ParaboloidSurface_HeaderFile
0015 #define _GeomEval_ParaboloidSurface_HeaderFile
0016
0017 #include <Geom_ElementarySurface.hxx>
0018
0019 //! Describes a circular paraboloid surface of revolution.
0020 //! A paraboloid is defined by its focal distance and is positioned
0021 //! in space by a coordinate system (a gp_Ax3 object), the origin
0022 //! of which is the vertex of the paraboloid.
0023 //!
0024 //! The parametric equation of the paraboloid is:
0025 //! @code
0026 //!   P(u,v) = O + v*cos(u)*XDir + v*sin(u)*YDir + v^2/(4*F)*ZDir
0027 //! @endcode
0028 //! where:
0029 //! - O, XDir, YDir and ZDir are respectively the origin,
0030 //!   the "X Direction", the "Y Direction" and the "Z Direction"
0031 //!   of its local coordinate system, and
0032 //! - F is the focal distance.
0033 //!
0034 //! The parametric range is:
0035 //! - [0, 2*Pi] for u, and
0036 //! - (-inf, +inf) for v.
0037 //!
0038 //! The implicit equation in local coordinates is:
0039 //! @code
0040 //!   X^2 + Y^2 - 4*F*Z = 0
0041 //! @endcode
0042 class GeomEval_ParaboloidSurface : public Geom_ElementarySurface
0043 {
0044 public:
0045   //! Creates a paraboloid surface with the given local coordinate system
0046   //! and focal distance.
0047   //! @param[in] thePosition the local coordinate system
0048   //! @param[in] theFocal the focal distance (must be > 0)
0049   //! @throw Standard_ConstructionError if theFocal <= 0
0050   Standard_EXPORT GeomEval_ParaboloidSurface(const gp_Ax3& thePosition, double theFocal);
0051
0052   //! Returns the focal distance of this paraboloid.
0053   Standard_EXPORT double Focal() const;
0054
0055   //! Assigns the value theFocal to the focal distance of this paraboloid.
0056   //! @param[in] theFocal the new focal distance (must be > 0)
0057   //! @throw Standard_ConstructionError if theFocal <= 0
0058   Standard_EXPORT void SetFocal(double theFocal);
0059
0060   //! Reversal is not supported for this eval surface.
0061   //! @throw Standard_NotImplemented
0062   Standard_EXPORT void UReverse() final;
0063
0064   //! Reversal is not supported for this eval surface.
0065   //! @throw Standard_NotImplemented
0066   Standard_EXPORT void VReverse() final;
0067
0068   //! Reversal is not supported for this eval surface.
0069   //! @throw Standard_NotImplemented
0070   Standard_EXPORT double UReversedParameter(const double U) const final;
0071
0072   //! Reversal is not supported for this eval surface.
0073   //! @throw Standard_NotImplemented
0074   Standard_EXPORT double VReversedParameter(const double V) const final;
0075
0076   //! Returns the parametric bounds U1, U2, V1 and V2 of this paraboloid.
0077   //! @param[out] U1 lower U bound (0)
0078   //! @param[out] U2 upper U bound (2*Pi)
0079   //! @param[out] V1 lower V bound (-Precision::Infinite())
0080   //! @param[out] V2 upper V bound (Precision::Infinite())
0081   Standard_EXPORT void Bounds(double& U1, double& U2, double& V1, double& V2) const final;
0082
0083   //! Returns True. The paraboloid is closed in U (period 2*Pi).
0084   Standard_EXPORT bool IsUClosed() const final;
0085
0086   //! Returns False.
0087   Standard_EXPORT bool IsVClosed() const final;
0088
0089   //! Returns True. The paraboloid is periodic in U (period 2*Pi).
0090   Standard_EXPORT bool IsUPeriodic() const final;
0091
0092   //! Returns False.
0093   Standard_EXPORT bool IsVPeriodic() const final;
0094
0095   //! Computes the U isoparametric curve.
0096   //! For a paraboloid, the U isoparametric curve is a parabola,
0097   //! which is not a standard Geom_Curve type.
0098   //! @throw Standard_NotImplemented
0099   Standard_EXPORT occ::handle<Geom_Curve> UIso(const double U) const final;
0100
0101   //! Computes the V isoparametric curve.
0102   //! For a paraboloid, the V isoparametric curve is a circle of radius |v|,
0103   //! which degenerates to a point at v=0.
0104   //! @throw Standard_NotImplemented
0105   Standard_EXPORT occ::handle<Geom_Curve> VIso(const double V) const final;
0106
0107   //! Computes the point P(U, V) on the surface.
0108   //! @code
0109   //!   P(U, V) = O + V*cos(U)*XDir + V*sin(U)*YDir + V^2/(4*F)*ZDir
0110   //! @endcode
0111   Standard_EXPORT gp_Pnt EvalD0(const double U, const double V) const final;
0112
0113   //! Computes the point and the first partial derivatives at (U, V).
0114   Standard_EXPORT Geom_Surface::ResD1 EvalD1(const double U, const double V) const final;
0115
0116   //! Computes the point and partial derivatives up to 2nd order at (U, V).
0117   Standard_EXPORT Geom_Surface::ResD2 EvalD2(const double U, const double V) const final;
0118
0119   //! Computes the point and partial derivatives up to 3rd order at (U, V).
0120   Standard_EXPORT Geom_Surface::ResD3 EvalD3(const double U, const double V) const final;
0121
0122   //! Computes the derivative of order Nu in the direction u
0123   //! and Nv in the direction v.
0124   //! @param[in] U the u parameter
0125   //! @param[in] V the v parameter
0126   //! @param[in] Nu derivative order in u (must be >= 0)
0127   //! @param[in] Nv derivative order in v (must be >= 0)
0128   //! @return the derivative vector
0129   //! @throw Geom_UndefinedDerivative if Nu + Nv < 1 or Nu < 0 or Nv < 0
0130   Standard_EXPORT gp_Vec EvalDN(const double U,
0131                                 const double V,
0132                                 const int    Nu,
0133                                 const int    Nv) const final;
0134
0135   //! Transformation is not supported for this eval geometry.
0136   //! @throw Standard_NotImplemented
0137   Standard_EXPORT void Transform(const gp_Trsf& T) final;
0138
0139   //! Creates a new object which is a copy of this paraboloid.
0140   Standard_EXPORT occ::handle<Geom_Geometry> Copy() const final;
0141
0142   //! Dumps the content of me into the stream.
0143   Standard_EXPORT void DumpJson(Standard_OStream& theOStream, int theDepth = -1) const final;
0144
0145   //! Returns the coefficients of the implicit equation of the
0146   //! quadric in the absolute Cartesian coordinate system:
0147   //! @code
0148   //!   A1*X^2 + A2*Y^2 + A3*Z^2 + 2*(B1*X*Y + B2*X*Z + B3*Y*Z) +
0149   //!   2*(C1*X + C2*Y + C3*Z) + D = 0
0150   //! @endcode
0151   //! In local coordinates the equation is: X^2 + Y^2 - 4*F*Z = 0.
0152   Standard_EXPORT void Coefficients(double& A1,
0153                                     double& A2,
0154                                     double& A3,
0155                                     double& B1,
0156                                     double& B2,
0157                                     double& B3,
0158                                     double& C1,
0159                                     double& C2,
0160                                     double& C3,
0161                                     double& D) const;
0162
0163   DEFINE_STANDARD_RTTIEXT(GeomEval_ParaboloidSurface, Geom_ElementarySurface)
0164
0165 private:
0166   double myFocal;
0167 };
0168
0169 #endif // _GeomEval_ParaboloidSurface_HeaderFile