💿🐜 Antkeeper source code https://antkeeper.com
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/*
* 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 <http://www.gnu.org/licenses/>.
*/
#ifndef ANTKEEPER_ECS_ASTRONOMY_SYSTEM_HPP
#define ANTKEEPER_ECS_ASTRONOMY_SYSTEM_HPP
#include "entity-system.hpp"
#include "ecs/entity.hpp"
#include "scene/directional-light.hpp"
#include "utility/fundamental-types.hpp"
#include "physics/frame.hpp"
#include "renderer/passes/sky-pass.hpp"
namespace ecs {
/**
* Calculates apparent properties of celestial bodies relative to an observer (magnitude, angular radius, horizontal coordinates) and modifies their model component and/or light component to render them accordingly.
*/
class astronomy_system:
public entity_system
{
public:
astronomy_system(ecs::registry& registry);
/**
* Scales then adds the timestep `dt` to the current time, then recalculates the positions of celestial bodies.
*
* @param t Time, in seconds.
* @param dt Delta time, in seconds.
*/
virtual void update(double t, double dt);
/**
* Sets the current universal time.
*
* @param time Universal time, in days.
*/
void set_universal_time(double time);
/**
* Sets the factor by which the timestep `dt` will be scaled before being added to the current universal time.
*
* @param scale Factor by which to scale the timestep.
*/
void set_time_scale(double scale);
/**
* Sets the reference body, from which observations are taking place.
*
* @param entity Entity of the reference body.
*/
void set_reference_body(ecs::entity entity);
/**
* Sets the axial tilt of the reference body.
*
* @param angle Angle between the reference body's rotational axis and its orbital axis, in radians.
*/
void set_reference_body_axial_tilt(double angle);
/**
* Sets the location of the observer using spherical coordinates in BCBF space.
*
* @param location Spherical coordinates of the observer, in reference body BCBF space, in the ISO order of radial distance, polar angle (radians), and azimuthal angle (radians).
*/
void set_observer_location(const double3& location);
void set_sun_light(scene::directional_light* light);
void set_sky_pass(sky_pass* pass);
private:
double universal_time;
double time_scale;
ecs::entity reference_body;
double reference_body_axial_tilt;
double reference_body_axial_rotation;
double3 observer_location;
scene::directional_light* sun_light;
sky_pass* sky_pass;
physics::frame<double> inertial_to_bcbf;
physics::frame<double> bcbf_to_topocentric;
physics::frame<double> inertial_to_topocentric;
physics::frame<double> sez_to_ezs;
physics::frame<double> ezs_to_sez;
};
} // namespace ecs
#endif // ANTKEEPER_ECS_ASTRONOMY_SYSTEM_HPP