add imgui menu bar draft

framework/imgui/CMakeLists.txt

@@ -7,6 +7,10 @@ project(imgui_lib CXX)
 add_library(imgui_service
 	./src/mm/services/imgui_s.hpp
 	./src/mm/services/imgui_s.cpp
+
+	# sneak
+	./src/mm/services/imgui_menu_bar.hpp
+	./src/mm/services/imgui_menu_bar.cpp
 )
 
 target_include_directories(imgui_service PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/src")

framework/imgui/src/mm/services/imgui_menu_bar.cpp

@@ -0,0 +1,98 @@
+#include "./imgui_menu_bar.hpp"
+
+#include <mm/engine.hpp>
+#include <entt/core/hashed_string.hpp>
+
+#include <imgui/imgui.h>
+
+#include <unordered_set>
+
+#include <mm/logger.hpp>
+#define LOG_CRIT(...)		__LOG_CRIT(	"ImGuiMenuBar", __VA_ARGS__)
+#define LOG_ERROR(...)		__LOG_ERROR("ImGuiMenuBar", __VA_ARGS__)
+#define LOG_WARN(...)		__LOG_WARN(	"ImGuiMenuBar", __VA_ARGS__)
+#define LOG_INFO(...)		__LOG_INFO(	"ImGuiMenuBar", __VA_ARGS__)
+#define LOG_DEBUG(...)		__LOG_DEBUG("ImGuiMenuBar", __VA_ARGS__)
+#define LOG_TRACE(...)		__LOG_TRACE("ImGuiMenuBar", __VA_ARGS__)
+
+namespace MM::Services {
+
+	bool ImGuiMenuBar::enable(Engine& engine) {
+		MM::Logger::initSectionLogger("ImGuiMenuBar");
+
+		auto* sdl_ss = engine.tryService<MM::Services::SDLService>();
+		if (sdl_ss) {
+			_event_handle = sdl_ss->addEventHandler([this](const SDL_Event& e) -> bool {
+				if (e.type == SDL_KEYDOWN && !e.key.repeat && e.key.keysym.sym == toggle_key) {
+					show_menu_bar = !show_menu_bar;
+				}
+				return false; // invis
+			});
+		} else {
+			LOG_WARN("no SDLService, skipping toggle hotkey");
+		}
+
+		return true;
+	}
+
+	void ImGuiMenuBar::disable(Engine& engine) {
+		if (_event_handle) {
+			auto* sdl_ss = engine.tryService<MM::Services::SDLService>();
+			sdl_ss->removeEventHandler(_event_handle);
+			_event_handle = nullptr;
+		}
+	}
+
+	std::vector<UpdateStrategies::UpdateCreationInfo> ImGuiMenuBar::registerUpdates(void) {
+	using namespace entt::literals;
+		return {
+			{
+				"ImGuiMenuBar::render"_hs,
+				"ImGuiMenuBar::render",
+				[this](Engine& e){ renderImGui(e); }
+			}
+		};
+	}
+
+	void ImGuiMenuBar::renderImGui(Engine& engine) {
+		if (show_menu_bar && ImGui::BeginMainMenuBar()) {
+
+			// TODO: better solution?
+			std::unordered_set<std::string> done;
+
+			// we dont check for errors in section_order
+			for (const auto& section_key : section_order) {
+				if (menu_tree.count(section_key)) {
+					renderSection(engine, section_key, menu_tree[section_key]);
+
+					done.emplace(section_key);
+				}
+			}
+
+			for (auto& [section_key, section_data] : menu_tree) {
+				if (done.count(section_key)) {
+					continue;
+				}
+
+				renderSection(engine, section_key, section_data);
+
+				done.emplace(section_key); // we dont need this
+			}
+
+
+			ImGui::Text("%.1fFPS", ImGui::GetIO().Framerate);
+			ImGui::EndMainMenuBar();
+		}
+	}
+
+	void ImGuiMenuBar::renderSection(Engine& engine, const std::string& section_key, section_t& section) {
+		if (ImGui::BeginMenu(section_key.c_str())) {
+			for (auto& item : section) {
+				item.second(engine);
+			}
+			ImGui::EndMenu();
+		}
+	}
+
+} // namespace MM::Services
+

framework/imgui/src/mm/services/imgui_menu_bar.hpp

@@ -0,0 +1,49 @@
+#pragma once
+
+#include <mm/services/sdl_service.hpp>
+
+#include <map>
+#include <variant>
+#include <functional>
+
+namespace MM::Services {
+
+	class ImGuiMenuBar : public Service {
+		public:
+			const char* name(void) override { return "ImGuiMenuBar"; }
+
+			bool enable(Engine& engine) override;
+			void disable(Engine& engine) override;
+
+			std::vector<UpdateStrategies::UpdateCreationInfo> registerUpdates(void) override;
+
+		public:
+			bool show_menu_bar = true;
+
+			SDL_Keycode toggle_key = SDLK_F2;
+
+			using menu_item_callback_t = std::function<void(MM::Engine&)>;
+
+			using section_t = std::map<std::string, menu_item_callback_t>;
+
+			// menu tree
+			// section -> section_t -> menu_item_t
+			// section is stable id key
+			// menus contain stable id keys
+			std::map<std::string, section_t> menu_tree;
+
+			std::vector<std::string> section_order {
+				"Engine",
+			};
+
+		private:
+			MM::Services::SDLService::EventHandlerHandle _event_handle = nullptr;
+
+		private:
+			void renderImGui(Engine& engine);
+
+			void renderSection(Engine& engine, const std::string& section_key, section_t& section);
+	};
+
+} // namespace MM::Services
+