cpp/motions/coordinates.cpp
2024-08-23 18:33:38 +02:00

44 lines
1.3 KiB
C++

//
// Created by dominik on 8/22/24.
//
#include "coordinates.h"
#include <cmath>
#include <iostream>
#include <ostream>
SphericalPos rotate(const SphericalPos& old_pos, const double alpha, const double beta) {
const double sin_alpha{std::sin(alpha)};
const double cos_alpha{std::cos(alpha)};
const double sin_beta{std::sin(beta)};
const double cos_beta{std::cos(beta)};
const double cos_theta{old_pos.cos_theta};
if (std::abs(cos_theta) == 1) {
return xyz_to_spherical(CartesianPos{cos_alpha * cos_beta, cos_alpha * sin_beta, cos_alpha * cos_theta});
}
const double norm{std::sqrt(1 - cos_theta * cos_theta) + 1e-15};
auto [x, y , z] = spherical_to_xyz(old_pos);
const auto new_pos = CartesianPos{
cos_alpha * x + sin_alpha * (-x * z * sin_beta - y * cos_beta) / norm,
cos_alpha * y + sin_alpha * (-y * z * sin_beta + x * cos_beta) / norm,
cos_alpha * z + sin_alpha * norm * sin_beta
};
return xyz_to_spherical(new_pos);
}
CartesianPos spherical_to_xyz(const SphericalPos& pos) {
const double sin_theta = std::sin(std::acos(pos.cos_theta));
return {sin_theta * std::cos(pos.phi), sin_theta * std::sin(pos.phi), pos.cos_theta};
}
SphericalPos xyz_to_spherical(const CartesianPos& pos) {
return {pos.z, std::atan2(pos.y, pos.x)};
}