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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/>.
- */
-
- #include "ecs/systems/solar-system.hpp"
- #include "ecs/components/celestial-body-component.hpp"
- #include "ecs/entity.hpp"
-
- namespace ecs {
-
- static constexpr double seconds_per_day = 24.0 * 60.0 * 60.0;
-
- solar_system::solar_system(ecs::registry& registry):
- entity_system(registry),
- universal_time(0.0),
- days_per_timestep(1.0 / seconds_per_day),
- ke_tolerance(1e-6),
- ke_iterations(10)
- {}
-
- void solar_system::update(double t, double dt)
- {
- // Add scaled timestep to current time
- set_universal_time(universal_time + dt * days_per_timestep);
-
- // Update orbital state of intrasolar celestial bodies
- registry.view<celestial_body_component>().each(
- [&](ecs::entity entity, auto& body)
- {
- auto elements = body.orbital_elements;
- elements.a += body.orbital_rate.a * universal_time;
- elements.e += body.orbital_rate.e * universal_time;
- elements.w += body.orbital_rate.w * universal_time;
- elements.ta += body.orbital_rate.ta * universal_time;
- elements.i += body.orbital_rate.i * universal_time;
- elements.raan += body.orbital_rate.raan * universal_time;
-
- // Calculate ecliptic orbital position
- //body.orbital_state.r = astro::orbital_elements_to_ecliptic(elements, ke_tolerance, ke_iterations);
- });
- }
-
- void solar_system::set_universal_time(double time)
- {
- universal_time = time;
- }
-
- void solar_system::set_time_scale(double scale)
- {
- days_per_timestep = scale / seconds_per_day;
- }
-
- } // namespace ecs
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