initial import, >900commits predate this

systems/fast_sky_sun/CMakeLists.txt

@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.2)
+project(fast_sky_sun_system CXX)
+
+add_library(fast_sky_sun_system
+	src/mm/systems/fast_sky_sun_system.hpp
+	src/mm/systems/fast_sky_sun_system.cpp
+)
+
+target_include_directories(fast_sky_sun_system PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/src")
+
+target_link_libraries(fast_sky_sun_system
+	engine
+	fast_sky_render_task
+)
+
+if(EMSCRIPTEN)
+	set_target_properties(fast_sky_sun_system PROPERTIES COMPILE_FLAGS "-s USE_SDL=2")
+	set_target_properties(fast_sky_sun_system PROPERTIES LINK_FLAGS "-s USE_SDL=2")
+endif()
+

systems/fast_sky_sun/src/mm/systems/fast_sky_sun_system.cpp

@@ -0,0 +1,23 @@
+#include "./fast_sky_sun_system.hpp"
+
+#include <mm/services/scene_service_interface.hpp>
+
+#include <entt/entity/registry.hpp>
+
+#include <mm/opengl/render_tasks/fast_sky_render_task.hpp>
+
+#include <glm/trigonometric.hpp>
+
+namespace MM::Systems {
+
+void FastSkySun(Scene& scene, float delta) {
+	auto& sky_ctx = scene.ctx<MM::OpenGL::RenderTasks::FastSkyContext>();
+
+	sky_ctx.time += delta * 0.2f;
+
+	sky_ctx.fsun.y = glm::sin(sky_ctx.time * 0.01f);
+	sky_ctx.fsun.z = glm::cos(sky_ctx.time * 0.01f);
+}
+
+} // MM::Systems
+

systems/fast_sky_sun/src/mm/systems/fast_sky_sun_system.hpp

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <mm/engine_fwd.hpp>
+
+namespace MM::Systems {
+
+	// this system updates time and sun depending on time with the time delta
+	void FastSkySun(Scene& scene, float delta);
+
+} // MM::Systems
+