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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 "renderer/passes/sky-pass.hpp"
- #include "resources/resource-manager.hpp"
- #include "resources/string-table.hpp"
- #include "gl/rasterizer.hpp"
- #include "gl/framebuffer.hpp"
- #include "gl/shader-program.hpp"
- #include "gl/shader-input.hpp"
- #include "gl/vertex-buffer.hpp"
- #include "gl/vertex-array.hpp"
- #include "gl/vertex-attribute-type.hpp"
- #include "gl/drawing-mode.hpp"
- #include "gl/texture-2d.hpp"
- #include "gl/texture-wrapping.hpp"
- #include "gl/texture-filter.hpp"
- #include "renderer/vertex-attributes.hpp"
- #include "renderer/render-context.hpp"
- #include "renderer/model.hpp"
- #include "renderer/material.hpp"
- #include "scene/camera.hpp"
- #include "utility/fundamental-types.hpp"
- #include "color/color.hpp"
- #include "astro/illuminance.hpp"
- #include "math/interpolation.hpp"
- #include "geom/cartesian.hpp"
- #include "geom/spherical.hpp"
- #include "physics/orbit/orbit.hpp"
- #include "physics/light/photometry.hpp"
- #include <cmath>
- #include <stdexcept>
- #include <glad/glad.h>
- #include <iostream>
-
- sky_pass::sky_pass(gl::rasterizer* rasterizer, const gl::framebuffer* framebuffer, resource_manager* resource_manager):
- render_pass(rasterizer, framebuffer),
- mouse_position({0.0f, 0.0f}),
- sky_model(nullptr),
- sky_material(nullptr),
- sky_model_vao(nullptr),
- sky_shader_program(nullptr),
- moon_model(nullptr),
- moon_material(nullptr),
- moon_model_vao(nullptr),
- moon_shader_program(nullptr),
- time_tween(nullptr),
- observer_altitude_tween(0.0f, math::lerp<float, float>),
- sun_position_tween(float3{1.0f, 0.0f, 0.0f}, math::lerp<float3, float>),
- sun_color_tween(float3{1.0f, 1.0f, 1.0f}, math::lerp<float3, float>),
- topocentric_frame_translation({0, 0, 0}, math::lerp<float3, float>),
- topocentric_frame_rotation(math::quaternion<float>::identity(), math::nlerp<float>)
- {
- // Load star catalog
- string_table* star_catalog = resource_manager->load<string_table>("stars.csv");
-
- // Allocate star catalog vertex data
- star_count = 0;
- if (star_catalog->size() > 0)
- star_count = star_catalog->size() - 1;
- std::size_t star_vertex_size = 6;
- 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;
-
- // 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];
-
- double ra = 0.0;
- double dec = 0.0;
- double vmag = 0.0;
- double bv_color = 0.0;
-
- // Parse star catalog entry
- try
- {
- ra = std::stod(catalog_row[1]);
- dec = std::stod(catalog_row[2]);
- vmag = std::stod(catalog_row[3]);
- bv_color = std::stod(catalog_row[4]);
- }
- catch (const std::exception& e)
- {
- continue;
- }
-
- // Convert right ascension and declination from degrees to radians
- ra = math::wrap_radians(math::radians(ra));
- dec = math::wrap_radians(math::radians(dec));
-
- // Transform spherical equatorial coordinates to rectangular equatorial coordinates
- double3 position_bci = geom::spherical::to_cartesian(double3{1.0, dec, ra});
-
- // Transform coordinates from equatorial space to inertial space
- physics::frame<double> bci_to_inertial = physics::orbit::inertial::to_bci({0, 0, 0}, 0.0, math::radians(23.4393)).inverse();
- double3 position_inertial = bci_to_inertial * position_bci;
-
- // Convert color index to color temperature
- double cct = color::index::bv_to_cct(bv_color);
-
- // Calculate XYZ color from color temperature
- double3 color_xyz = color::cct::to_xyz(cct);
-
- // Transform XYZ color to ACEScg colorspace
- double3 color_acescg = color::xyz::to_acescg(color_xyz);
-
- // Convert apparent magnitude to irradiance (W/m^2)
- double vmag_irradiance = std::pow(10.0, 0.4 * (-vmag - 19.0 + 0.4));
-
- // Convert irradiance to illuminance
- double vmag_illuminance = vmag_irradiance * (683.0 * 0.14);
-
- // Scale color by illuminance
- double3 scaled_color = color_acescg * vmag_illuminance;
-
- // Build vertex
- *(star_vertex++) = static_cast<float>(position_inertial.x);
- *(star_vertex++) = static_cast<float>(position_inertial.y);
- *(star_vertex++) = static_cast<float>(position_inertial.z);
- *(star_vertex++) = static_cast<float>(scaled_color.x);
- *(star_vertex++) = static_cast<float>(scaled_color.y);
- *(star_vertex++) = static_cast<float>(scaled_color.z);
- }
-
- // Unload star catalog
- resource_manager->unload("stars.csv");
-
- // Create star catalog VBO
- star_catalog_vbo = new gl::vertex_buffer(star_count * star_vertex_stride, star_vertex_data);
-
- // Create star catalog VAO
- star_catalog_vao = new gl::vertex_array();
-
- // Bind star catalog vertex attributes
- std::size_t vao_offset = 0;
- star_catalog_vao->bind_attribute(VERTEX_POSITION_LOCATION, *star_catalog_vbo, 3, gl::vertex_attribute_type::float_32, star_vertex_stride, 0);
- vao_offset += 3;
- star_catalog_vao->bind_attribute(VERTEX_COLOR_LOCATION, *star_catalog_vbo, 3, gl::vertex_attribute_type::float_32, star_vertex_stride, sizeof(float) * vao_offset);
-
- // Free star catalog vertex data
- delete[] star_vertex_data;
-
- // Load star shader
- star_shader_program = resource_manager->load<gl::shader_program>("star.glsl");
- star_model_view_input = star_shader_program->get_input("model_view");
- star_projection_input = star_shader_program->get_input("projection");
- star_distance_input = star_shader_program->get_input("star_distance");
- star_exposure_input = star_shader_program->get_input("camera.exposure");
- }
-
- sky_pass::~sky_pass()
- {}
-
- void sky_pass::render(render_context* context) const
- {
- rasterizer->use_framebuffer(*framebuffer);
-
- glDisable(GL_BLEND);
- glDisable(GL_DEPTH_TEST);
- glDepthMask(GL_FALSE);
- glEnable(GL_CULL_FACE);
- glCullFace(GL_BACK);
-
- auto viewport = framebuffer->get_dimensions();
- rasterizer->set_viewport(0, 0, std::get<0>(viewport), std::get<1>(viewport));
-
- float time = (*time_tween)[context->alpha];
- float2 resolution = {static_cast<float>(std::get<0>(viewport)), static_cast<float>(std::get<1>(viewport))};
-
- const scene::camera& camera = *context->camera;
- float clip_near = camera.get_clip_near_tween().interpolate(context->alpha);
- float clip_far = camera.get_clip_far_tween().interpolate(context->alpha);
- float3 model_scale = float3{1.0f, 1.0f, 1.0f} * (clip_near + clip_far) * 0.5f;
- float4x4 model = math::scale(math::identity4x4<float>, model_scale);
- float4x4 view = math::resize<4, 4>(math::resize<3, 3>(camera.get_view_tween().interpolate(context->alpha)));
- float4x4 model_view = view * model;
- float4x4 projection = camera.get_projection_tween().interpolate(context->alpha);
- float4x4 view_projection = projection * view;
- float4x4 model_view_projection = projection * model_view;
- float exposure = std::exp2(camera.get_exposure_tween().interpolate(context->alpha));
-
- // Interpolate observer altitude
- float observer_altitude = observer_altitude_tween.interpolate(context->alpha);
-
- // Construct tweened inertial to topocentric frame
- physics::frame<float> topocentric_frame =
- {
- topocentric_frame_translation.interpolate(context->alpha),
- topocentric_frame_rotation.interpolate(context->alpha)
- };
-
- // Get topocentric space direction to sun
- float3 sun_position = sun_position_tween.interpolate(context->alpha);
- float3 sun_direction = math::normalize(sun_position);
-
- // Interpolate sun color
- float3 sun_color = sun_color_tween.interpolate(context->alpha);
-
- // Draw sky model
- {
- rasterizer->use_program(*sky_shader_program);
-
- // Upload shader parameters
- if (model_view_projection_input)
- model_view_projection_input->upload(model_view_projection);
- if (mouse_input)
- mouse_input->upload(mouse_position);
- if (resolution_input)
- resolution_input->upload(resolution);
- if (time_input)
- time_input->upload(time);
- if (exposure_input)
- exposure_input->upload(exposure);
-
- if (observer_altitude_input)
- observer_altitude_input->upload(observer_altitude);
- if (sun_direction_input)
- sun_direction_input->upload(sun_direction);
- if (sun_angular_radius_input)
- sun_angular_radius_input->upload(sun_angular_radius);
- if (sun_color_input)
- sun_color_input->upload(sun_color);
- if (scale_height_rm_input)
- scale_height_rm_input->upload(scale_height_rm);
- if (rayleigh_scattering_input)
- rayleigh_scattering_input->upload(rayleigh_scattering);
- if (mie_scattering_input)
- mie_scattering_input->upload(mie_scattering);
- if (mie_anisotropy_input)
- mie_anisotropy_input->upload(mie_anisotropy);
- if (atmosphere_radii_input)
- atmosphere_radii_input->upload(atmosphere_radii);
-
- sky_material->upload(context->alpha);
-
- rasterizer->draw_arrays(*sky_model_vao, sky_model_drawing_mode, sky_model_start_index, sky_model_index_count);
- }
-
- glEnable(GL_BLEND);
- //glBlendFunc(GL_SRC_ALPHA, GL_ONE);
- glBlendFunc(GL_ONE, GL_ONE);
-
- // Draw moon model
- /*
- float3 moon_position = {0, 0, 0};
- if (moon_position.y >= -moon_angular_radius)
- {
-
-
- float moon_distance = (clip_near + clip_far) * 0.5f;
- float moon_radius = moon_angular_radius * moon_distance;
-
- math::transform<float> moon_transform;
- moon_transform.translation = moon_position * -moon_distance;
- moon_transform.rotation = math::quaternion<float>::identity();
- moon_transform.scale = {moon_radius, moon_radius, moon_radius};
-
- model = math::matrix_cast(moon_transform);
- model_view = view * model;
- model_view_projection = projection * model_view;
- float3x3 normal_model = math::transpose(math::inverse(math::resize<3, 3>(model)));
-
- rasterizer->use_program(*moon_shader_program);
- if (moon_model_view_projection_input)
- moon_model_view_projection_input->upload(model_view_projection);
- if (moon_normal_model_input)
- moon_normal_model_input->upload(normal_model);
- if (moon_moon_position_input)
- moon_moon_position_input->upload(moon_position);
- if (moon_sun_position_input)
- moon_sun_position_input->upload(sun_position);
- moon_material->upload(context->alpha);
- rasterizer->draw_arrays(*moon_model_vao, moon_model_drawing_mode, moon_model_start_index, moon_model_index_count);
- }
- */
-
- // Draw stars
- {
- float star_distance = (clip_near + clip_far) * 0.5f;
-
- model = math::resize<4, 4>(math::matrix_cast<float>(topocentric_frame.rotation));
- model = math::scale(model, {star_distance, star_distance, star_distance});
-
- model_view = view * model;
-
- rasterizer->use_program(*star_shader_program);
- if (star_model_view_input)
- star_model_view_input->upload(model_view);
- if (star_projection_input)
- star_projection_input->upload(projection);
- if (star_distance_input)
- star_distance_input->upload(star_distance);
- if (star_exposure_input)
- star_exposure_input->upload(exposure);
-
- rasterizer->draw_arrays(*star_catalog_vao, gl::drawing_mode::points, 0, star_count);
- }
- }
-
- void sky_pass::set_sky_model(const model* model)
- {
- sky_model = model;
-
- if (sky_model)
- {
- sky_model_vao = model->get_vertex_array();
-
- const std::vector<model_group*>& groups = *model->get_groups();
- for (model_group* group: groups)
- {
- sky_material = group->get_material();
- sky_model_drawing_mode = group->get_drawing_mode();
- sky_model_start_index = group->get_start_index();
- sky_model_index_count = group->get_index_count();
- }
-
- if (sky_material)
- {
- sky_shader_program = sky_material->get_shader_program();
-
- if (sky_shader_program)
- {
- model_view_projection_input = sky_shader_program->get_input("model_view_projection");
- mouse_input = sky_shader_program->get_input("mouse");
- resolution_input = sky_shader_program->get_input("resolution");
- time_input = sky_shader_program->get_input("time");
- exposure_input = sky_shader_program->get_input("camera.exposure");
-
- observer_altitude_input = sky_shader_program->get_input("observer_altitude");
- sun_direction_input = sky_shader_program->get_input("sun_direction");
- sun_color_input = sky_shader_program->get_input("sun_color");
- sun_angular_radius_input = sky_shader_program->get_input("sun_angular_radius");
- scale_height_rm_input = sky_shader_program->get_input("scale_height_rm");
- rayleigh_scattering_input = sky_shader_program->get_input("rayleigh_scattering");
- mie_scattering_input = sky_shader_program->get_input("mie_scattering");
- mie_anisotropy_input = sky_shader_program->get_input("mie_anisotropy");
- atmosphere_radii_input = sky_shader_program->get_input("atmosphere_radii");
- }
- }
- }
- else
- {
- sky_model_vao = nullptr;
- }
- }
-
- void sky_pass::set_moon_model(const model* model)
- {
- moon_model = model;
-
- if (moon_model)
- {
- moon_model_vao = model->get_vertex_array();
-
- const std::vector<model_group*>& groups = *model->get_groups();
- for (model_group* group: groups)
- {
- moon_material = group->get_material();
- moon_model_drawing_mode = group->get_drawing_mode();
- moon_model_start_index = group->get_start_index();
- moon_model_index_count = group->get_index_count();
- }
-
- if (moon_material)
- {
- moon_shader_program = moon_material->get_shader_program();
-
- if (moon_shader_program)
- {
- moon_model_view_projection_input = moon_shader_program->get_input("model_view_projection");
- moon_normal_model_input = moon_shader_program->get_input("normal_model");
- moon_moon_position_input = moon_shader_program->get_input("moon_position");
- moon_sun_position_input = moon_shader_program->get_input("sun_position");
- }
- }
- }
- else
- {
- moon_model = nullptr;
- }
- }
-
- void sky_pass::update_tweens()
- {
- observer_altitude_tween.update();
- sun_position_tween.update();
- sun_color_tween.update();
- topocentric_frame_translation.update();
- topocentric_frame_rotation.update();
- }
-
- void sky_pass::set_time_tween(const tween<double>* time)
- {
- this->time_tween = time;
- }
-
- void sky_pass::set_topocentric_frame(const physics::frame<float>& frame)
- {
- topocentric_frame_translation[1] = frame.translation;
- topocentric_frame_rotation[1] = frame.rotation;
- }
-
- void sky_pass::set_sun_position(const float3& position)
- {
- sun_position_tween[1] = position;
- }
-
- void sky_pass::set_sun_color(const float3& color)
- {
- sun_color_tween[1] = color;
- }
-
- void sky_pass::set_sun_angular_radius(float radius)
- {
- sun_angular_radius = radius;
- }
-
- void sky_pass::set_observer_altitude(float altitude)
- {
- observer_altitude_tween[1] = altitude;
- }
-
- void sky_pass::set_scale_heights(float rayleigh, float mie)
- {
- scale_height_rm = {rayleigh, mie};
- }
-
- void sky_pass::set_scattering_coefficients(const float3& r, const float3& m)
- {
- rayleigh_scattering = r;
- mie_scattering = m;
- }
-
- void sky_pass::set_mie_anisotropy(float g)
- {
- mie_anisotropy = {g, g * g};
- }
-
- void sky_pass::set_atmosphere_radii(float inner, float outer)
- {
- atmosphere_radii.x = inner;
- atmosphere_radii.y = outer;
- atmosphere_radii.z = outer * outer;
- }
-
- void sky_pass::handle_event(const mouse_moved_event& event)
- {
- mouse_position = {static_cast<float>(event.x), static_cast<float>(event.y)};
- }
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