/*
* 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_HORIZONTAL_HPP
#define ANTKEEPER_COORDINATES_HORIZONTAL_HPP
#include "coordinates/rectangular.hpp"
#include "coordinates/spherical.hpp"
#include "utility/fundamental-types.hpp"
#include
namespace coordinates {
namespace rectangular {
/// Rectangular local horizontal coordinate system in which the x-axis points north, the y-axis points east, and the z-axis points to the vertical.
namespace horizontal {
/**
* Produces a matrix which rotates rectangular coordinates from local horizontal space into equatorial space.
*
* @param lat Observer's latitude, in radians.
* @param lst Local sidereal time, in radians.
* @return Rotation matrix.
*
* @see coordinates::equatorial
*/
template
math::matrix3 to_equatorial(T lat, T lst);
/**
* Rotates rectangular coordinates from local horizontal space into equatorial space.
*
* @param v Rectangular coordinates in local horizontal space.
* @param lat Observer's latitude, in radians.
* @param lst Local sidereal time, in radians.
* @return Rectangular coordinates in equatorial space.
*
* @see coordinates::equatorial
*/
template
math::vector3 to_equatorial(const math::vector3& v, T lat, T lst);
/**
* Produces a matrix which rotates rectangular coordinates from local horizontal space into 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 Rotation matrix.
*
* @see coordinates::ecliptic
*/
template
math::matrix3 to_ecliptic(T ecl, T lat, T lst);
/**
* Rotates rectangular coordinates from local horizontal space into ecliptic space.
*
* @param v Rectangular coordinates in 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 Rectangular coordinates in ecliptic space.
*
* @see coordinates::ecliptic
*/
template
math::vector3 to_ecliptic(const math::vector3& v, T ecl, T lat, T lst);
} // namespace horizontal
} // namespace rectangular
namespace spherical {
/// Spherical local horizontal coordinate system.
namespace horizontal {
/**
* Rotates spherical coordinates from local horizontal space into equatorial space.
*
* @param v Spherical coordinates in local horizontal space, in the ISO order of radial distance, altitude (radians), and azimuth (radians).
* @param lat Observer's latitude, in radians.
* @param lst Local sidereal time, in radians.
* @return Spherical coordinates in equatorial space, in the ISO order of radial distance, declination (radians), and right ascension (radians).
*
* @see coordinates::equatorial
*/
template
math::vector3 to_equatorial(const math::vector3& v, T lat, T lst);
/**
* Rotates spherical coordinates from local horizontal space into ecliptic space.
*
* @param v Spherical coordinates in local horizontal space, in the ISO order of radial distance, altitude (radians), and azimuth (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 ecliptic space, in the ISO order of radial distance, ecliptic latitude (radians), and ecliptic longitude (radians).
*
* @see coordinates::ecliptic
*/
template
math::vector3 to_ecliptic(const math::vector3& v, T ecl, T lat, T lst);
} // namespace horizontal
} // namespace spherical
namespace rectangular {
namespace horizontal {
template
math::matrix3 to_equatorial(T lat, T lst)
{
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
{
c_lst * s_lat, s_lst * s_lat, -c_lat,
s_lst, c_lst, T(0.0),
c_lst * c_lat, s_lst * c_lat, s_lat
};
}
template
math::vector3 to_equatorial(const math::vector3& v, T lat, T lst)
{
return to_equatorial(lat, lst) * v;
}
template
math::matrix3 to_ecliptic(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_lat * s_lst * c_ecl - c_lat * s_ecl, s_lat * s_lst * -s_ecl - c_lat * c_ecl,
s_lst, -c_lst * c_ecl, c_lst * s_ecl,
c_lat * c_lst, c_lat * s_lst * c_ecl + s_lat * s_ecl, c_lat * s_lst * -s_ecl + s_lat * c_ecl
};
}
template
math::vector3 to_ecliptic(const math::vector3& v, T ecl, T lat, T lst)
{
return to_ecliptic(ecl, lat, lst) * v;
}
} // namespace horizontal
} // namespace rectangular
namespace spherical {
namespace horizontal {
template
math::vector3 to_equatorial(const math::vector3& v, T lat, T lst)
{
return coordinates::rectangular::to_spherical
(
coordinates::rectangular::horizontal::to_equatorial
(
coordinates::spherical::to_rectangular(v),
lat,
lst
)
);
}
template
math::vector3 to_ecliptic(const math::vector3& v, T ecl, T lat, T lst)
{
return coordinates::rectangular::to_spherical
(
coordinates::rectangular::horizontal::to_ecliptic
(
coordinates::spherical::to_rectangular(v),
ecl,
lat,
lst
)
);
}
} // namespace horizontal
} // namespace spherical
} // namespace coordinates
#endif // ANTKEEPER_COORDINATES_HORIZONTAL_HPP