/*
* Copyright (C) 2021 Christopher J. Howard
*
* This file is part of Antkeeper source code.
*
* Antkeeper source code is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Antkeeper source code is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Antkeeper source code. If not, see .
*/
#ifndef ANTKEEPER_COORDINATES_ECLIPTIC_HPP
#define ANTKEEPER_COORDINATES_ECLIPTIC_HPP
#include "coordinates/rectangular.hpp"
#include "coordinates/spherical.hpp"
#include "utility/fundamental-types.hpp"
#include
namespace coordinates {
namespace rectangular {
/// Rectangular coordinate system with the plane of the Earth's orbit as the fundamental plane. This is a right-handed coordinate system with the x-axis pointing to the vernal equinox, the y-axis pointing east, and the z-axis is the north orbital pole.
namespace ecliptic {
/**
* Produces a matrix which rotates rectangular coordinates from ecliptic space into equatorial space.
*
* @param ecl Obliquity of the ecliptic, in radians.
* @return Rotation matrix.
*
* @see coordinates::rectangular::equatorial
*/
template
math::matrix3 to_equatorial(T ecl);
/**
* Rotates rectangular coordinates from ecliptic space into equatorial space.
*
* @param v Rectangular coordinates in ecliptic space.
* @param ecl Obliquity of the ecliptic, in radians.
* @return Rectangular coordinates in equatorial space.
*
* @see coordinates::rectangular::equatorial
*/
template
math::vector3 to_equatorial(const math::vector3& v, T ecl);
/**
* Produces a matrix which rotates rectangular coordinates from ecliptic space into local horizontal space.
*
* @param ecl Obliquity of the ecliptic, in radians.
* @param lat Observer's latitude, in radians.
* @param lst Local sidereal time, in radians.
* @return Rotation matrix.
*
* @see coordinates::rectangular::horizontal
*/
template
math::matrix3 to_horizontal(T ecl, T lat, T lst);
/**
* Rotates rectangular coordinates from ecliptic space into local horizontal space.
*
* @param v Rectangular coordinates in ecliptic space.
* @param ecl Obliquity of the ecliptic, in radians.
* @param lat Observer's latitude, in radians.
* @param lst Local sidereal time, in radians.
* @return Rectangular coordinates in local horizontal space.
*
* @see coordinates::rectangular::horizontal
*/
template
math::vector3 to_horizontal(const math::vector3& v, T ecl, T lat, T lst);
} // namespace ecliptic
} // namespace rectangular
namespace spherical {
/// Spherical ecliptic coordinate system.
namespace ecliptic {
/**
* Rotates spherical coordinates from ecliptic space into equatorial space.
*
* @param v Spherical coordinates in ecliptic space, in the ISO order of radial distance, ecliptic latitude (radians), and ecliptic longitude (radians).
* @param ecl Obliquity of the ecliptic, in radians.
* @return Spherical coordinates in equatorial space, in the ISO order of radial distance, declination (radians), and right ascension (radians).
*
* @see coordinates::spherical::equatorial
*/
template
math::vector3 to_equatorial(const math::vector3& v, T ecl);
/**
* Rotates spherical coordinates from ecliptic space into local horizontal space.
*
* @param v Spherical coordinates in ecliptic space, in the ISO order of radial distance, ecliptic latitude (radians), and ecliptic longitude (radians).
* @param ecl Obliquity of the ecliptic, in radians.
* @param lat Observer's latitude, in radians.
* @param lst Local sidereal time, in radians.
* @return Spherical coordinates in local horizontal space, in the ISO order of radial distance, altitude (radians), and azimuth (radians).
*
* @see coordinates::spherical::horizontal
*/
template
math::vector3 to_horizontal(const math::vector3& v, T ecl, T lat, T lst);
} // namespace ecliptic
} // namespace spherical
namespace rectangular {
namespace ecliptic {
template
math::matrix3 to_equatorial(T ecl)
{
const T c_ecl = std::cos(ecl);
const T s_ecl = std::sin(ecl);
return math::matrix3
{
T(1.0), T(0.0), T(0.0),
T(0.0), c_ecl, s_ecl,
T(0.0), -s_ecl, c_ecl
};
}
template
math::vector3 to_equatorial(const math::vector3& v, T ecl)
{
return to_equatorial(ecl) * v;
}
template
math::matrix3 to_horizontal(T ecl, T lat, T lst)
{
const T c_ecl = std::cos(ecl);
const T s_ecl = std::sin(ecl);
const T c_lat = std::cos(lat);
const T s_lat = std::sin(lat);
const T c_lst = std::cos(lst);
const T s_lst = std::sin(lst);
return math::matrix3
{
s_lat * c_lst, s_lst, c_lat * c_lst,
s_lat * s_lst * c_ecl - c_lat * s_ecl, -c_lst * c_ecl, c_lat * s_lst * c_ecl + s_lat * s_ecl,
s_lat * s_lst * -s_ecl - c_lat * c_ecl, c_lst * s_ecl, c_lat * s_lst * -s_ecl + s_lat * c_ecl
};
}
template
math::vector3 to_horizontal(const math::vector3& v, T ecl, T lat, T lst)
{
return to_horizontal(ecl, lat, lst) * v;
}
} // namespace ecliptic
} // namespace rectangular
namespace spherical {
namespace ecliptic {
template
math::vector3 to_equatorial(const math::vector3& v, T ecl)
{
return coordinates::rectangular::to_spherical
(
coordinates::rectangular::ecliptic::to_equatorial
(
coordinates::spherical::to_rectangular(v),
ecl
)
);
}
template
math::vector3 to_horizontal(const math::vector3& v, T ecl, T lat, T lst)
{
return coordinates::rectangular::to_spherical
(
coordinates::rectangular::ecliptic::to_horizontal
(
coordinates::spherical::to_rectangular(v),
ecl,
lat,
lst
)
);
}
} // namespace ecliptic
} // namespace spherical
} // namespace coordinates
#endif // ANTKEEPER_COORDINATES_ECLIPTIC_HPP