💿🐜 Antkeeper source code
https://antkeeper.com
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71 lines
2.2 KiB
71 lines
2.2 KiB
/*
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* Copyright (C) 2021 Christopher J. Howard
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*
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* This file is part of Antkeeper source code.
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*
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* Antkeeper source code is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Antkeeper source code is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "ecs/systems/solar-system.hpp"
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#include "astro/coordinates.hpp"
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#include "astro/orbit.hpp"
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#include "astro/constants.hpp"
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#include "ecs/components/celestial-body-component.hpp"
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#include "ecs/entity.hpp"
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namespace ecs {
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static constexpr double seconds_per_day = 24.0 * 60.0 * 60.0;
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solar_system::solar_system(ecs::registry& registry):
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entity_system(registry),
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universal_time(0.0),
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days_per_timestep(1.0 / seconds_per_day),
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ke_tolerance(1e-6),
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ke_iterations(10)
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{}
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void solar_system::update(double t, double dt)
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{
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// Add scaled timestep to current time
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set_universal_time(universal_time + dt * days_per_timestep);
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// Update orbital state of intrasolar celestial bodies
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registry.view<celestial_body_component>().each(
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[&](ecs::entity entity, auto& body)
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{
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astro::orbital_elements elements = body.orbital_elements;
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elements.a += body.orbital_rate.a * universal_time;
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elements.ec += body.orbital_rate.ec * universal_time;
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elements.w += body.orbital_rate.w * universal_time;
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elements.ma += body.orbital_rate.ma * universal_time;
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elements.i += body.orbital_rate.i * universal_time;
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elements.om += body.orbital_rate.om * universal_time;
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// Calculate ecliptic orbital position
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body.orbital_state.r = astro::orbital_elements_to_ecliptic(elements, ke_tolerance, ke_iterations);
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});
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}
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void solar_system::set_universal_time(double time)
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{
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universal_time = time;
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}
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void solar_system::set_time_scale(double scale)
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{
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days_per_timestep = scale / seconds_per_day;
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}
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} // namespace ecs
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