// Copyright (c) 2025 OPEN CASCADE SAS // // This file is part of Open CASCADE Technology software library. // // This library is free software; you can redistribute it and/or modify it under // the terms of the GNU Lesser General Public License version 2.1 as published // by the Free Software Foundation, with special exception defined in the file // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT // distribution for complete text of the license and disclaimer of any warranty. // // Alternatively, this file may be used under the terms of Open CASCADE // commercial license or contractual agreement. #ifndef _Geom2dEval_LogarithmicSpiralCurve_HeaderFile #define _Geom2dEval_LogarithmicSpiralCurve_HeaderFile #include "Geom2d_Curve.hxx" #include "gp_Ax2d.hxx" class gp_Trsf2d; class Geom2d_Geometry; //! Describes a 2D logarithmic (equiangular) spiral curve. //! The polar equation is r = a*exp(b*t). //! //! The parametric equation is: //! @code //! C(t) = O + a*exp(b*t)*cos(t)*XDir + a*exp(b*t)*sin(t)*YDir //! @endcode //! where: //! - O, XDir are from the local coordinate system, //! - YDir is the perpendicular to XDir, //! - a is the scale factor (> 0), //! - b is the growth exponent (> 0). //! //! The parameter range is (-inf, +inf). //! The angle between tangent and radial direction is constant = atan(1/b). class Geom2dEval_LogarithmicSpiralCurve : public Geom2d_Curve { public: //! Creates a logarithmic spiral. //! @param[in] thePosition the local coordinate system //! @param[in] theScale the scale factor (must be > 0) //! @param[in] theGrowthExponent the growth exponent (must be > 0) //! @throw Standard_ConstructionError if theScale <= 0 or theGrowthExponent <= 0 Standard_EXPORT Geom2dEval_LogarithmicSpiralCurve(const gp_Ax2d& thePosition, double theScale, double theGrowthExponent); //! Returns the local coordinate system. Standard_EXPORT const gp_Ax2d& Position() const; //! Returns the scale factor. Standard_EXPORT double Scale() const; //! Returns the growth exponent. Standard_EXPORT double GrowthExponent() const; //! Reversal is not supported for this eval curve. //! @throw Standard_NotImplemented Standard_EXPORT void Reverse() final; //! Reversal is not supported for this eval curve. //! @throw Standard_NotImplemented Standard_EXPORT double ReversedParameter(const double U) const final; //! Returns -Precision::Infinite(). Standard_EXPORT double FirstParameter() const final; //! Returns Precision::Infinite(). Standard_EXPORT double LastParameter() const final; //! Returns false. Standard_EXPORT bool IsClosed() const final; //! Returns false. Standard_EXPORT bool IsPeriodic() const final; //! Returns GeomAbs_CN. Standard_EXPORT GeomAbs_Shape Continuity() const final; //! Returns true for any N >= 0. Standard_EXPORT bool IsCN(const int N) const final; //! Computes the point at parameter U. Standard_EXPORT gp_Pnt2d EvalD0(const double U) const final; //! Computes the point and first derivative at parameter U. Standard_EXPORT Geom2d_Curve::ResD1 EvalD1(const double U) const final; //! Computes the point and first two derivatives at parameter U. Standard_EXPORT Geom2d_Curve::ResD2 EvalD2(const double U) const final; //! Computes the point and first three derivatives at parameter U. Standard_EXPORT Geom2d_Curve::ResD3 EvalD3(const double U) const final; //! Computes the N-th derivative at parameter U. //! @throw Standard_RangeError if N < 1 Standard_EXPORT gp_Vec2d EvalDN(const double U, const int N) const final; //! Transformation is not supported for this eval geometry. //! @throw Standard_NotImplemented Standard_EXPORT void Transform(const gp_Trsf2d& T) final; //! Creates a new object which is a copy of this curve. Standard_EXPORT occ::handle Copy() const final; //! Dumps the content of me into the stream. Standard_EXPORT void DumpJson(Standard_OStream& theOStream, int theDepth = -1) const final; DEFINE_STANDARD_RTTIEXT(Geom2dEval_LogarithmicSpiralCurve, Geom2d_Curve) private: gp_Ax2d myPosition; //!< Local coordinate system double myScale; //!< Scale factor (> 0) double myGrowthExponent; //!< Growth exponent (> 0) }; #endif // _Geom2dEval_LogarithmicSpiralCurve_HeaderFile