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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 "game/world.hpp"
- #include "scene/text.hpp"
- #include "physics/light/vmag.hpp"
- #include "color/color.hpp"
- #include "game/component/atmosphere.hpp"
- #include "game/component/blackbody.hpp"
- #include "game/component/celestial-body.hpp"
- #include "game/component/orbit.hpp"
- #include "game/component/terrain.hpp"
- #include "game/component/transform.hpp"
- #include "game/component/observer.hpp"
- #include "game/system/astronomy.hpp"
- #include "game/system/orbit.hpp"
- #include "game/system/atmosphere.hpp"
- #include "entity/commands.hpp"
- #include "entity/archetype.hpp"
- #include "geom/spherical.hpp"
- #include "gl/drawing-mode.hpp"
- #include "gl/vertex-array.hpp"
- #include "gl/vertex-attribute.hpp"
- #include "gl/vertex-buffer.hpp"
- #include "physics/light/photometry.hpp"
- #include "physics/orbit/orbit.hpp"
- #include "physics/orbit/ephemeris.hpp"
- #include "physics/time/gregorian.hpp"
- #include "physics/time/constants.hpp"
- #include "physics/time/utc.hpp"
- #include "render/material.hpp"
- #include "render/model.hpp"
- #include "render/passes/shadow-map-pass.hpp"
- #include "render/vertex-attribute.hpp"
- #include "resources/resource-manager.hpp"
- #include "scene/ambient-light.hpp"
- #include "scene/directional-light.hpp"
- #include "gl/texture-wrapping.hpp"
- #include "gl/texture-filter.hpp"
- #include "render/material-flags.hpp"
- #include "geom/solid-angle.hpp"
- #include "config.hpp"
- #include <iostream>
-
- namespace game {
- namespace world {
-
- /// Loads an ephemeris.
- static void load_ephemeris(game::context& ctx);
-
- /// Creates the fixed stars.
- static void create_stars(game::context& ctx);
-
- /// Creates the Sun.
- static void create_sun(game::context& ctx);
-
- /// Creates the Earth-Moon system.
- static void create_earth_moon_system(game::context& ctx);
-
- /// Creates the Earth.
- static void create_earth(game::context& ctx);
-
- /// Creates the Moon.
- static void create_moon(game::context& ctx);
-
- void cosmogenesis(game::context& ctx)
- {
- ctx.logger->push_task("Generating cosmos");
-
- load_ephemeris(ctx);
- create_stars(ctx);
- create_sun(ctx);
- create_earth_moon_system(ctx);
-
- ctx.logger->pop_task(EXIT_SUCCESS);
- }
-
- void create_observer(game::context& ctx)
- {
- ctx.logger->push_task("Creating observer");
-
- try
- {
- // Create observer entity
- entity::id observer_eid = ctx.entity_registry->create();
- ctx.entities["observer"] = observer_eid;
-
- // Construct observer component
- game::component::observer observer;
-
- // Set observer reference body
- if (auto it = ctx.entities.find("earth"); it != ctx.entities.end())
- observer.reference_body_eid = it->second;
- else
- observer.reference_body_eid = entt::null;
-
- // Set observer location
- observer.elevation = 0.0;
- observer.latitude = 0.0;
- observer.longitude = 0.0;
-
- // Assign observer component to observer entity
- ctx.entity_registry->emplace<game::component::observer>(observer_eid, observer);
-
- // Set atmosphere system active atmosphere
- ctx.atmosphere_system->set_active_atmosphere(observer.reference_body_eid);
-
- // Set astronomy system observer
- ctx.astronomy_system->set_observer(observer_eid);
- }
- catch (const std::exception&)
- {
- ctx.logger->pop_task(EXIT_FAILURE);
- return;
- }
-
- ctx.logger->pop_task(EXIT_SUCCESS);
- }
-
- void set_location(game::context& ctx, double elevation, double latitude, double longitude)
- {
- if (auto it = ctx.entities.find("observer"); it != ctx.entities.end())
- {
- entity::id observer_eid = it->second;
-
- if (ctx.entity_registry->valid(observer_eid) && ctx.entity_registry->all_of<game::component::observer>(observer_eid))
- {
- // Update observer location
- ctx.entity_registry->patch<game::component::observer>
- (
- observer_eid,
- [&](auto& component)
- {
- component.elevation = elevation;
- component.latitude = latitude;
- component.longitude = longitude;
- }
- );
- }
- }
- }
-
- void set_time(game::context& ctx, double t)
- {
- ctx.logger->push_task("Setting time to UT1 " + std::to_string(t));
- try
- {
- ctx.astronomy_system->set_time(t);
- ctx.orbit_system->set_time(t);
- }
- catch (const std::exception&)
- {
- ctx.logger->pop_task(EXIT_FAILURE);
- return;
- }
- ctx.logger->pop_task(EXIT_SUCCESS);
- }
-
- void set_time(game::context& ctx, int year, int month, int day, int hour, int minute, double second)
- {
- double longitude = 0.0;
-
- // Get longitude of observer
- if (auto it = ctx.entities.find("observer"); it != ctx.entities.end())
- {
- entity::id observer_eid = it->second;
- if (ctx.entity_registry->valid(observer_eid))
- {
- const auto observer = ctx.entity_registry->try_get<game::component::observer>(observer_eid);
- if (observer)
- longitude = observer->longitude;
- }
- }
-
- // Calculate UTC offset at longitude
- const double utc_offset = physics::time::utc::offset<double>(longitude);
-
- // Convert time from Gregorian to UT1
- const double t = physics::time::gregorian::to_ut1<double>(year, month, day, hour, minute, second, utc_offset);
-
- set_time(ctx, t);
- }
-
- void set_time_scale(game::context& ctx, double scale)
- {
- // Convert time scale from seconds to days
- const double astronomical_scale = scale / physics::time::seconds_per_day<double>;
-
- ctx.orbit_system->set_time_scale(astronomical_scale);
- ctx.astronomy_system->set_time_scale(astronomical_scale);
- }
-
- void load_ephemeris(game::context& ctx)
- {
- ctx.logger->push_task("Loading ephemeris");
-
- try
- {
- std::string ephemeris_filename;
- if (ctx.config->contains("ephemeris"))
- {
- ephemeris_filename = (*ctx.config)["ephemeris"].get<std::string>();
- }
- else
- {
- ctx.logger->warning("No ephemeris set in config");
- ctx.logger->pop_task(EXIT_FAILURE);
- return;
- }
-
- ctx.orbit_system->set_ephemeris(ctx.resource_manager->load<physics::orbit::ephemeris<double>>(ephemeris_filename));
- }
- catch (const std::exception&)
- {
- ctx.logger->pop_task(EXIT_FAILURE);
- return;
- }
-
- ctx.logger->pop_task(EXIT_SUCCESS);
- }
-
- void create_stars(game::context& ctx)
- {
- ctx.logger->push_task("Generating fixed stars");
-
- // Load star catalog
- string_table* star_catalog = nullptr;
- try
- {
- std::string star_catalog_filename;
- if (ctx.config->contains("star_catalog"))
- {
- star_catalog_filename = (*ctx.config)["star_catalog"].get<std::string>();
- }
- else
- {
- ctx.logger->warning("No star catalog set in config");
- ctx.logger->pop_task(EXIT_FAILURE);
- return;
- }
-
- star_catalog = ctx.resource_manager->load<string_table>(star_catalog_filename);
- }
- catch (const std::exception&)
- {
- ctx.logger->pop_task(EXIT_FAILURE);
- return;
- }
-
- // Allocate star catalog vertex data
- std::size_t star_count = 0;
- if (star_catalog->size() > 0)
- star_count = star_catalog->size() - 1;
- std::size_t star_vertex_size = 7;
- std::size_t star_vertex_stride = star_vertex_size * sizeof(float);
- float* star_vertex_data = new float[star_count * star_vertex_size];
- float* star_vertex = star_vertex_data;
-
- // Init starlight illuminance
- double3 starlight_illuminance = {0, 0, 0};
-
- // Build star catalog vertex data
- for (std::size_t i = 1; i < star_catalog->size(); ++i)
- {
- const string_table_row& catalog_row = (*star_catalog)[i];
-
- // Parse star catalog item
- double ra = 0.0;
- double dec = 0.0;
- double vmag = 0.0;
- double bv = 0.0;
- try
- {
- ra = std::stod(catalog_row[1]);
- dec = std::stod(catalog_row[2]);
- vmag = std::stod(catalog_row[3]);
- bv = std::stod(catalog_row[4]);
- }
- catch (const std::exception&)
- {
- ctx.logger->warning("Invalid star catalog item on row " + std::to_string(i));
- }
-
- // Convert right ascension and declination from degrees to radians
- ra = math::wrap_radians(math::radians(ra));
- dec = math::wrap_radians(math::radians(dec));
-
- // Convert ICRF coordinates from spherical to Cartesian
- double3 position = physics::orbit::frame::bci::cartesian(double3{1.0, dec, ra});
-
- // Convert color index to color temperature
- double cct = color::index::bv_to_cct(bv);
-
- // Calculate XYZ color from color temperature
- double3 color_xyz = color::cct::to_xyz(cct);
-
- // Transform XYZ color to ACEScg colorspace
- double3 color_acescg = color::aces::ap1<double>.from_xyz * color_xyz;
-
- // Convert apparent magnitude to brightness factor relative to a 0th magnitude star
- double brightness = physics::light::vmag::to_brightness(vmag);
-
- // Build vertex
- *(star_vertex++) = static_cast<float>(position.x());
- *(star_vertex++) = static_cast<float>(position.y());
- *(star_vertex++) = static_cast<float>(position.z());
- *(star_vertex++) = static_cast<float>(color_acescg.x());
- *(star_vertex++) = static_cast<float>(color_acescg.y());
- *(star_vertex++) = static_cast<float>(color_acescg.z());
- *(star_vertex++) = static_cast<float>(brightness);
-
- // Calculate spectral illuminance
- double3 illuminance = color_acescg * physics::light::vmag::to_illuminance(vmag);
-
- // Add spectral illuminance to total starlight illuminance
- starlight_illuminance += illuminance;
- }
-
- // Unload star catalog
- ctx.resource_manager->unload("stars.csv");
-
- // Allocate stars model
- render::model* stars_model = new render::model();
-
- // Get model VBO and VAO
- gl::vertex_buffer* vbo = stars_model->get_vertex_buffer();
- gl::vertex_array* vao = stars_model->get_vertex_array();
-
- // Resize model VBO and upload vertex data
- vbo->resize(star_count * star_vertex_stride, star_vertex_data);
-
- // Free star catalog vertex data
- delete[] star_vertex_data;
-
- std::size_t attribute_offset = 0;
-
- // Define position vertex attribute
- gl::vertex_attribute position_attribute;
- position_attribute.buffer = vbo;
- position_attribute.offset = attribute_offset;
- position_attribute.stride = star_vertex_stride;
- position_attribute.type = gl::vertex_attribute_type::float_32;
- position_attribute.components = 3;
- attribute_offset += position_attribute.components * sizeof(float);
-
- // Define color vertex attribute
- gl::vertex_attribute color_attribute;
- color_attribute.buffer = vbo;
- color_attribute.offset = attribute_offset;
- color_attribute.stride = star_vertex_stride;
- color_attribute.type = gl::vertex_attribute_type::float_32;
- color_attribute.components = 4;
- attribute_offset += color_attribute.components * sizeof(float);
-
- // Bind vertex attributes to VAO
- vao->bind(render::vertex_attribute::position, position_attribute);
- vao->bind(render::vertex_attribute::color, color_attribute);
-
- // Load star material
- render::material* star_material = ctx.resource_manager->load<render::material>("fixed-star.mtl");
-
- // Create model group
- render::model_group* stars_model_group = stars_model->add_group("stars");
- stars_model_group->set_material(star_material);
- stars_model_group->set_drawing_mode(gl::drawing_mode::points);
- stars_model_group->set_start_index(0);
- stars_model_group->set_index_count(star_count);
-
- // Pass stars model to sky pass
- ctx.sky_pass->set_stars_model(stars_model);
-
- // Pass starlight illuminance to astronomy system
- ctx.astronomy_system->set_starlight_illuminance(starlight_illuminance);
-
- ctx.logger->pop_task(EXIT_SUCCESS);
- }
-
- void create_sun(game::context& ctx)
- {
- ctx.logger->push_task("Generating Sun");
-
- try
- {
- // Create sun entity
- entity::archetype* sun_archetype = ctx.resource_manager->load<entity::archetype>("sun.ent");
- entity::id sun_eid = sun_archetype->create(*ctx.entity_registry);
- ctx.entities["sun"] = sun_eid;
-
- // Create sun directional light scene object
- scene::directional_light* sun_light = new scene::directional_light();
- sun_light->set_color({0, 0, 0});
- sun_light->update_tweens();
-
- // Create sky ambient light scene object
- scene::ambient_light* sky_light = new scene::ambient_light();
- sky_light->set_color({0, 0, 0});
- sky_light->update_tweens();
-
- // Create bounce directional light scene object
- scene::directional_light* bounce_light = new scene::directional_light();
- bounce_light->set_color({0, 0, 0});
- bounce_light->look_at({0, 0, 0}, {0, 1, 0}, {1, 0, 0});
- bounce_light->update_tweens();
-
- // Add sun light scene objects to surface scene
- ctx.surface_scene->add_object(sun_light);
- ctx.surface_scene->add_object(sky_light);
- //ctx.surface_scene->add_object(bounce_light);
-
- // Pass direct sun light scene object to shadow map pass and astronomy system
- ctx.surface_shadow_map_pass->set_light(sun_light);
- ctx.astronomy_system->set_sun_light(sun_light);
- ctx.astronomy_system->set_sky_light(sky_light);
- ctx.astronomy_system->set_bounce_light(bounce_light);
- }
- catch (const std::exception&)
- {
- ctx.logger->pop_task(EXIT_FAILURE);
- return;
- }
-
- ctx.logger->pop_task(EXIT_SUCCESS);
- }
-
- void create_earth_moon_system(game::context& ctx)
- {
- ctx.logger->push_task("Generating Earth-Moon system");
-
- try
- {
- // Create Earth-Moon barycenter entity
- entity::archetype* em_bary_archetype = ctx.resource_manager->load<entity::archetype>("em-bary.ent");
- entity::id em_bary_eid = em_bary_archetype->create(*ctx.entity_registry);
- ctx.entities["em_bary"] = em_bary_eid;
-
- // Create Earth
- create_earth(ctx);
-
- // Create Moon
- create_moon(ctx);
- }
- catch (const std::exception&)
- {
- ctx.logger->pop_task(EXIT_FAILURE);
- return;
- }
-
- ctx.logger->pop_task(EXIT_SUCCESS);
- }
-
- void create_earth(game::context& ctx)
- {
- ctx.logger->push_task("Generating Earth");
-
- try
- {
- // Create earth entity
- entity::archetype* earth_archetype = ctx.resource_manager->load<entity::archetype>("earth.ent");
- entity::id earth_eid = earth_archetype->create(*ctx.entity_registry);
- ctx.entities["earth"] = earth_eid;
-
- // Assign orbital parent
- ctx.entity_registry->get<game::component::orbit>(earth_eid).parent = ctx.entities["em_bary"];
- }
- catch (const std::exception&)
- {
- ctx.logger->pop_task(EXIT_FAILURE);
- return;
- }
-
- ctx.logger->pop_task(EXIT_SUCCESS);
- }
-
- void create_moon(game::context& ctx)
- {
- ctx.logger->push_task("Generating Moon");
-
- try
- {
- // Create lunar entity
- entity::archetype* moon_archetype = ctx.resource_manager->load<entity::archetype>("moon.ent");
- entity::id moon_eid = moon_archetype->create(*ctx.entity_registry);
- ctx.entities["moon"] = moon_eid;
-
- // Assign orbital parent
- ctx.entity_registry->get<game::component::orbit>(moon_eid).parent = ctx.entities["em_bary"];
-
- // Pass moon model to sky pass
- ctx.sky_pass->set_moon_model(ctx.resource_manager->load<render::model>("moon.mdl"));
-
- // Create moon directional light scene object
- scene::directional_light* moon_light = new scene::directional_light();
- moon_light->set_color({0, 0, 0});
- moon_light->update_tweens();
-
- // Add moon light scene objects to surface scene
- ctx.surface_scene->add_object(moon_light);
-
- // Pass moon light scene object to astronomy system
- ctx.astronomy_system->set_moon_light(moon_light);
- }
- catch (const std::exception&)
- {
- ctx.logger->pop_task(EXIT_FAILURE);
- return;
- }
-
- ctx.logger->pop_task(EXIT_SUCCESS);
- }
-
- } // namespace world
- } // namespace game
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