// ____ ______ __ // / __ \ / ____// / // / /_/ // / / / // / ____// /___ / /___ PixInsight Class Library // /_/ \____//_____/ PCL 2.4.23 // ---------------------------------------------------------------------------- // pcl/ZenithalProjections.h - Released 2022-03-12T18:59:29Z // ---------------------------------------------------------------------------- // This file is part of the PixInsight Class Library (PCL). // PCL is a multiplatform C++ framework for development of PixInsight modules. // // Copyright (c) 2003-2022 Pleiades Astrophoto S.L. All Rights Reserved. // // Redistribution and use in both source and binary forms, with or without // modification, is permitted provided that the following conditions are met: // // 1. All redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // // 2. 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IN NO EVENT SHALL PLEIADES ASTROPHOTO OR ITS // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, // EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, BUSINESS // INTERRUPTION; PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; AND LOSS OF USE, // DATA OR PROFITS) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE // POSSIBILITY OF SUCH DAMAGE. // ---------------------------------------------------------------------------- #ifndef __PCL_ZenithalProjections_h #define __PCL_ZenithalProjections_h /// \file pcl/ZenithalProjections.h #include #include /* * Based on original work contributed by Andrés del Pozo. */ namespace pcl { // ---------------------------------------------------------------------------- /*! * \class ZenithalProjectionBase * \brief Base class of zenithal projection systems * * \ingroup astrometry_support */ class PCL_CLASS ZenithalProjectionBase : public ProjectionBase { protected: /*! * Default constructor. */ ZenithalProjectionBase() { m_theta0 = 90; } /*! * Copy constructor. */ ZenithalProjectionBase( const ZenithalProjectionBase& ) = default; /*! * Returns a dynamically allocated duplicate of this object. */ virtual ProjectionBase* Clone() const override = 0; /*! * Returns the WCS projection identifier for this projection system. */ virtual IsoString ProjCode() const override = 0; /*! * Returns the readable name of this projection system. */ virtual IsoString Name() const override = 0; protected: /*! * Transforms from world coordinates to native spherical coordinates. */ bool Project( DPoint& pW, const DPoint& pN ) const noexcept override { double rTheta = GetRTheta( pN ); double sinTheta, cosTheta; SinCos( Rad( pN.x ), sinTheta, cosTheta ); pW.x = rTheta * sinTheta; pW.y = -rTheta * cosTheta; return true; } /*! * Transforms from native spherical coordinates to world coordinates. */ bool Unproject( DPoint& pN, const DPoint& pW ) const noexcept override { pN.x = Deg( ArcTan( pW.x, -pW.y ) ); pN.y = GetTheta( Sqrt( pW.x*pW.x + pW.y*pW.y ) ); return true; } virtual double GetRTheta( const DPoint& np ) const = 0; virtual double GetTheta( double rTheta ) const = 0; }; // ---------------------------------------------------------------------------- /*! * \class ZenithalEqualAreaProjection * \brief Zenithal equal-area projection system * * \ingroup astrometry_support */ class PCL_CLASS ZenithalEqualAreaProjection: public ZenithalProjectionBase { public: /*! * Default constructor. */ ZenithalEqualAreaProjection() = default; /*! * Copy constructor. */ ZenithalEqualAreaProjection( const ZenithalEqualAreaProjection& ) = default; /*! * Returns a dynamically allocated duplicate of this object. */ ProjectionBase* Clone() const override { return new ZenithalEqualAreaProjection( *this ); } /*! * Returns the WCS projection identifier for this projection system. */ IsoString ProjCode() const override { return "ZEA"; } /*! * Returns the readable name of this projection system. */ IsoString Name() const override { return "Zenithal Equal Area"; } /*! * */ bool CheckBrokenLine( const DPoint& cp1, const DPoint& cp2 ) const noexcept override { DPoint np1 = m_sph.CelestialToNative( cp1 ); DPoint np2 = m_sph.CelestialToNative( cp2 ); return Min( Mod( Abs( np1.x - np2.x - 360 ), 360.0 ), Mod( Abs( np1.x - np2.x + 360 ), 360.0 ) ) < 180*Sin( Rad( 45 + (np1.y + np2.y)/2/2 ) ); } private: double GetRTheta( const DPoint& np ) const override { return 2 * Deg( Sin( Rad( (90 - np.y)/2 ) ) ); } double GetTheta( double rTheta ) const override { return 90 - 2*Deg( ArcSin( Rad( rTheta )/2 ) ); } }; // ---------------------------------------------------------------------------- /*! * \class StereographicProjection * \brief Stereographic projection system * * \ingroup astrometry_support */ class PCL_CLASS StereographicProjection: public ZenithalProjectionBase { public: /*! * Default constructor. */ StereographicProjection() = default; /*! * Copy constructor. */ StereographicProjection( const StereographicProjection& ) = default; /*! * Returns a dynamically allocated duplicate of this object. */ ProjectionBase* Clone() const override { return new StereographicProjection( *this ); } /*! * Returns the WCS projection identifier for this projection system. */ IsoString ProjCode() const override { return "STG"; } /*! * Returns the readable name of this projection system. */ IsoString Name() const override { return "Stereographic"; } /*! * */ bool CheckBrokenLine(const DPoint& cp1, const DPoint& cp2) const noexcept override { return true; } private: double GetRTheta( const DPoint& np ) const override { return 2 * Deg( Tan( Rad( (90 - np.y)/2 ) ) ); } double GetTheta( double rTheta ) const override { return 90 - 2*Deg( ArcTan( Rad( rTheta )/2 ) ); } }; // ---------------------------------------------------------------------------- } // pcl #endif // __PCL_ZenithalProjections_h // ---------------------------------------------------------------------------- // EOF pcl/ZenithalProjections.h - Released 2022-03-12T18:59:29Z