|
/*
|
|
* 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 "game/system/atmosphere.hpp"
|
|
#include "physics/gas/atmosphere.hpp"
|
|
#include "physics/gas/ozone.hpp"
|
|
#include "physics/number-density.hpp"
|
|
|
|
namespace game {
|
|
namespace system {
|
|
|
|
atmosphere::atmosphere(entity::registry& registry):
|
|
updatable(registry),
|
|
rgb_wavelengths{0, 0, 0},
|
|
rgb_ozone_cross_sections{0, 0, 0},
|
|
active_atmosphere_eid(entt::null),
|
|
sky_pass(nullptr)
|
|
{
|
|
registry.on_construct<game::component::atmosphere>().connect<&atmosphere::on_atmosphere_construct>(this);
|
|
registry.on_update<game::component::atmosphere>().connect<&atmosphere::on_atmosphere_update>(this);
|
|
registry.on_destroy<game::component::atmosphere>().connect<&atmosphere::on_atmosphere_destroy>(this);
|
|
}
|
|
|
|
atmosphere::~atmosphere()
|
|
{
|
|
registry.on_construct<game::component::atmosphere>().disconnect<&atmosphere::on_atmosphere_construct>(this);
|
|
registry.on_update<game::component::atmosphere>().disconnect<&atmosphere::on_atmosphere_update>(this);
|
|
registry.on_destroy<game::component::atmosphere>().disconnect<&atmosphere::on_atmosphere_destroy>(this);
|
|
}
|
|
|
|
void atmosphere::update(double t, double dt)
|
|
{}
|
|
|
|
void atmosphere::set_rgb_wavelengths(const double3& wavelengths)
|
|
{
|
|
rgb_wavelengths = wavelengths;
|
|
|
|
// Update ozone cross sections
|
|
rgb_ozone_cross_sections =
|
|
{
|
|
physics::gas::ozone::cross_section_293k<double>(wavelengths.x() * 1e9),
|
|
physics::gas::ozone::cross_section_293k<double>(wavelengths.y() * 1e9),
|
|
physics::gas::ozone::cross_section_293k<double>(wavelengths.z() * 1e9)
|
|
};
|
|
|
|
// Update atmosphere components
|
|
registry.view<component::atmosphere>().each
|
|
(
|
|
[&](entity::id entity_id, auto& component)
|
|
{
|
|
update_atmosphere(entity_id);
|
|
}
|
|
);
|
|
}
|
|
|
|
void atmosphere::set_sky_pass(::render::sky_pass* pass)
|
|
{
|
|
sky_pass = pass;
|
|
update_sky_pass();
|
|
}
|
|
|
|
void atmosphere::set_active_atmosphere(entity::id entity_id)
|
|
{
|
|
if (entity_id != active_atmosphere_eid)
|
|
{
|
|
active_atmosphere_eid = entity_id;
|
|
update_sky_pass();
|
|
}
|
|
}
|
|
|
|
void atmosphere::update_atmosphere(entity::id entity_id)
|
|
{
|
|
// Get atmosphere component of the entity
|
|
game::component::atmosphere* component = registry.try_get<game::component::atmosphere>(entity_id);
|
|
|
|
// Abort if entity has no atmosphere component
|
|
if (!component)
|
|
return;
|
|
|
|
// Calculate Rayleigh scattering coefficients
|
|
const double rayleigh_density = physics::number_density(component->rayleigh_concentration);
|
|
const double rayleigh_polarization = physics::gas::atmosphere::polarization(component->index_of_refraction, rayleigh_density);
|
|
component->rayleigh_scattering =
|
|
{
|
|
physics::gas::atmosphere::scattering(rayleigh_density, rayleigh_polarization, rgb_wavelengths.x()),
|
|
physics::gas::atmosphere::scattering(rayleigh_density, rayleigh_polarization, rgb_wavelengths.y()),
|
|
physics::gas::atmosphere::scattering(rayleigh_density, rayleigh_polarization, rgb_wavelengths.z())
|
|
};
|
|
|
|
// Calculate Mie scattering and extinction coefficients
|
|
const double mie_density = physics::number_density(component->mie_concentration);
|
|
const double mie_polarization = physics::gas::atmosphere::polarization(component->index_of_refraction, mie_density);
|
|
component->mie_scattering = physics::gas::atmosphere::scattering(mie_density, mie_polarization);
|
|
component->mie_extinction = physics::gas::atmosphere::extinction(component->mie_scattering, component->mie_albedo);
|
|
|
|
// Calculate ozone absorption coefficients
|
|
const double ozone_density = physics::number_density(component->ozone_concentration);
|
|
component->ozone_absorption =
|
|
{
|
|
physics::gas::ozone::absorption(rgb_ozone_cross_sections.x(), ozone_density),
|
|
physics::gas::ozone::absorption(rgb_ozone_cross_sections.y(), ozone_density),
|
|
physics::gas::ozone::absorption(rgb_ozone_cross_sections.z(), ozone_density)
|
|
};
|
|
|
|
// Update sky pass parameters
|
|
if (entity_id == active_atmosphere_eid)
|
|
{
|
|
update_sky_pass();
|
|
}
|
|
}
|
|
|
|
void atmosphere::update_sky_pass()
|
|
{
|
|
// Abort if no sky pass set
|
|
if (!sky_pass)
|
|
return;
|
|
|
|
// Abort if active atmosphere entity is not valid
|
|
if (!registry.valid(active_atmosphere_eid))
|
|
return;
|
|
|
|
// Get atmosphere component of the entity
|
|
game::component::atmosphere* component = registry.try_get<game::component::atmosphere>(active_atmosphere_eid);
|
|
|
|
// Abort if entity has no atmosphere component
|
|
if (!component)
|
|
return;
|
|
|
|
sky_pass->set_atmosphere_upper_limit(static_cast<float>(component->upper_limit));
|
|
sky_pass->set_rayleigh_parameters(static_cast<float>(component->rayleigh_scale_height), math::type_cast<float>(component->rayleigh_scattering));
|
|
sky_pass->set_mie_parameters(static_cast<float>(component->mie_scale_height), static_cast<float>(component->mie_scattering), static_cast<float>(component->mie_extinction), static_cast<float>(component->mie_anisotropy));
|
|
sky_pass->set_ozone_parameters(static_cast<float>(component->ozone_lower_limit), static_cast<float>(component->ozone_upper_limit), static_cast<float>(component->ozone_mode), math::type_cast<float>(component->ozone_absorption));
|
|
sky_pass->set_airglow_illuminance(math::type_cast<float>(component->airglow_illuminance));
|
|
}
|
|
|
|
void atmosphere::on_atmosphere_construct(entity::registry& registry, entity::id entity_id)
|
|
{
|
|
update_atmosphere(entity_id);
|
|
}
|
|
|
|
void atmosphere::on_atmosphere_update(entity::registry& registry, entity::id entity_id)
|
|
{
|
|
update_atmosphere(entity_id);
|
|
}
|
|
|
|
void atmosphere::on_atmosphere_destroy(entity::registry& registry, entity::id entity_id)
|
|
{
|
|
if (entity_id == active_atmosphere_eid)
|
|
active_atmosphere_eid = entt::null;
|
|
}
|
|
|
|
} // namespace system
|
|
} // namespace game
|