poleaxis.h

/*
    SPDX-FileCopyrightText: 2020 Chris Rowland <chris.rowland@cherryfield.me.uk>
 
    SPDX-License-Identifier: GPL-2.0-or-later
*/
 
#pragma once
 
#include <dms.h>
#include <skypoint.h>
#include "rotations.h"
 
/**
 *@class PoleAxis
 *@short PoleAxis class handles determining the mount Ha axis position given three positions taken with the same mount declination.
 *
 *@author Chris Rowland
 *@version 1.0
 */
class PoleAxis
{
    public:
        ///
        /// \brief dirCos converts primary and secondary angles to a directional cosine
        /// \param primary angle, can be Ra, Ha, Azimuth or the corresponding axis values
        /// \param secondary angle, can be Dec, Altitude.  90 deg is the pole
        /// \return V3 containing the directional cosine.
        static Rotations::V3 dirCos(const dms primary, const dms secondary);
 
        ///
        /// \brief dirCos converts a SkyPoint to a directional cosine
        /// \param sp SkyPoint with the position
        /// \return  V3 containing the directional cosine.
        ///
        static Rotations::V3 dirCos(const SkyPoint sp);
 
        ///
        /// \brief primary returns the primary dms value in the directional cosine
        /// \param dirCos
        /// \return primary angle, Ra, Ha, Azimuth etc.
        ///
        static dms primary(Rotations::V3 dirCos);
 
        ///
        /// \brief secondary returns the secondary dms angle in the directional cosine
        /// \param dirCos
        /// \return
        ///
        static dms secondary(Rotations::V3 dirCos);
 
        ///
        /// \brief skyPoint returns a skypoint derived from the directional cosine vector
        /// \param dc
        /// \return
        ///
        static SkyPoint skyPoint(Rotations::V3 dc);
 
        ///
        /// \brief poleAxis returns the pole axis vector given three SkyPoints with the same mount declination
        /// \param p1
        /// \param p2
        /// \param p3
        /// \return vector giving the direction of the pole. The rotation between the three points determines which pole
        /// the other pole can be determined either by reversing the sign of the declination and adding 12 hrs to the Ha or
        /// by negating the vector
        ///
        static Rotations::V3 poleAxis(SkyPoint p1, SkyPoint p2, SkyPoint p3);
 
};