Integrate standalone FSUI into Panda SDL frontend

include/config.hpp

@@ -1,6 +1,7 @@
 #pragma once
 #include <filesystem>
 #include <string>
+#include <vector>
 
 #include "audio/dsp_core.hpp"
 #include "frontend_settings.hpp"
@@ -110,6 +111,15 @@ struct EmulatorConfig {
 
 	static constexpr size_t maxRecentGames = 8;
 	std::vector<std::filesystem::path> recentlyPlayed;
+	std::vector<std::filesystem::path> fsuiGameListPaths;
+	std::vector<std::filesystem::path> fsuiGameListRecursivePaths;
+	std::filesystem::path fsuiCoversPath = "";
+	int fsuiDefaultGameView = 0;
+	int fsuiGameSort = 0;
+	bool fsuiGameSortReverse = false;
+	std::string fsuiTheme = "Dark";
+	std::string fsuiPromptIconPack = "Auto";
+	std::filesystem::path fsuiBackgroundImagePath = "";
 
 	// Frontend window settings
 	struct WindowSettings {

include/emulator.hpp

@@ -126,6 +126,7 @@ class Emulator {
 	ServiceManager& getServiceManager() { return kernel.getServiceManager(); }
 	LuaManager& getLua() { return lua; }
 	AudioDeviceInterface& getAudioDevice() { return audioDevice; }
+	const std::optional<std::filesystem::path>& getROMPath() const { return romPath; }
 
 	RendererType getRendererType() const { return config.rendererType; }
 	Renderer* getRenderer() { return gpu.getRenderer(); }

include/frontend_settings.hpp

@@ -28,6 +28,7 @@ struct FrontendSettings {
 	WindowIcon icon = WindowIcon::Rpog;
 	std::string language = "en";
 	bool showImGuiDebugPanel = true;
+	bool enableFullscreenUI = false;
 	#ifdef IMGUI_FRONTEND
 	bool stretchImGuiOutputToWindow = true;
 	#else
@@ -39,4 +40,5 @@ struct FrontendSettings {
 
 	static WindowIcon iconFromString(std::string inString);
 	static const char* iconToString(WindowIcon icon);
+	static bool defaultFullscreenUIEnabled();
 };

include/panda_sdl/imgui_layer.hpp

@@ -4,10 +4,17 @@
 
 #include <SDL.h>
 
+#include <filesystem>
 #include <functional>
+#include <memory>
 #include <optional>
 
 #include "emulator.hpp"
+#include "fsui/backend_sdl.hpp"
+#include "fsui/fsui.hpp"
+#include "panda_sdl/panda_fsui.hpp"
+
+struct ImFont;
 
 class ImGuiLayer {
   public:
@@ -30,13 +37,24 @@ class ImGuiLayer {
 	void showPauseMenuFromController();
 
   private:
+	bool useFullscreenUI();
 	void drawDebugPanel();
-	void drawPausePanel();
-	void drawSettingsPanel();
+	void drawClassicPausePanel();
+	void drawClassicSettingsPanel();
+	void drawSettingsGeneralSection(bool& reloadSettings);
+	void drawSettingsWindowSection(bool& reloadSettings);
+	void drawSettingsUISection(bool& reloadSettings);
+	void drawSettingsGraphicsSection(bool& reloadSettings);
+	void drawSettingsAudioSection(bool& reloadSettings);
+	void drawSettingsBatterySection(bool& reloadSettings);
+	void drawSettingsSDSection(bool& reloadSettings);
 
 	SDL_Window* window = nullptr;
 	SDL_GLContext glContext = nullptr;
 	Emulator& emu;
+	fsui::FontStack fontStack;
+	fsui::SdlImGuiBackend imguiBackend;
+	PandaFsuiAdapter fsuiAdapter;
 
 	bool showDebug = true;
 	bool showPauseMenu = false;
@@ -44,6 +62,7 @@ class ImGuiLayer {
 	bool isPaused = false;
 	bool captureKeyboard = false;
 	bool captureMouse = false;
+	bool fullscreenSelectorMode = false;
 
 	std::function<void(bool)> onPauseChange;
 	std::function<void(bool)> onVsyncChange;

include/panda_sdl/panda_fsui.hpp

@@ -0,0 +1,92 @@
+#pragma once
+
+#ifdef IMGUI_FRONTEND
+
+#include <SDL.h>
+
+#include <filesystem>
+#include <functional>
+#include <optional>
+#include <vector>
+
+#include "fsui/fsui.hpp"
+
+class Emulator;
+
+class PandaFsuiAdapter {
+  public:
+	enum class ClassicUiRequest {
+		None,
+		Return,
+		OpenSettings,
+	};
+
+	PandaFsuiAdapter(SDL_Window* window, Emulator& emu);
+
+	bool initialize(const fsui::FontStack& fonts);
+	void shutdown(bool clear_state);
+	void render();
+	void consumeCommands();
+
+	void setSelectorMode(bool selector_mode);
+	bool isSelectorMode() const;
+	bool hasActiveWindow() const;
+	void openPauseMenu();
+	void returnToPreviousWindow();
+	void returnToMainWindow();
+	void switchToSettings();
+
+	std::optional<std::filesystem::path> consumeLaunchPath();
+	bool consumeCloseSelector();
+	ClassicUiRequest consumeClassicUiRequest();
+
+	void setPauseCallback(std::function<void(bool)> callback);
+	void setVsyncCallback(std::function<void(bool)> callback);
+	void setExitToSelectorCallback(std::function<void()> callback);
+
+  private:
+	struct ParsedMetadata;
+	struct LanguageOption;
+
+	void syncUiStateFromConfig();
+	void persistUiState(bool reload);
+	void seedGameListPathsIfNeeded();
+	std::vector<std::filesystem::path> currentScanRoots() const;
+	bool hasSupportedExtension(const std::filesystem::path& path) const;
+	std::vector<fsui::GameEntry> buildGameList();
+	std::vector<fsui::SettingsPageDescriptor> buildSettingsPages(fsui::SettingsScope scope);
+	fsui::CurrentGameInfo buildCurrentGameInfo();
+	std::vector<fsui::MenuItemDescriptor> buildLandingItems();
+	std::vector<fsui::MenuItemDescriptor> buildStartItems();
+	std::vector<fsui::MenuItemDescriptor> buildExitItems();
+	std::vector<fsui::MenuItemDescriptor> buildPauseItems();
+	std::vector<fsui::MenuItemDescriptor> buildGameLaunchOptions(const fsui::GameEntry& entry);
+
+	std::optional<ParsedMetadata> readMetadataForPath(const std::filesystem::path& path) const;
+	fsui::GameEntry buildGameListEntry(const std::filesystem::directory_entry& entry) const;
+	std::filesystem::path defaultCoverDirectory() const;
+	std::filesystem::path findCoverPath(const std::filesystem::path& rom_path, const std::string& title_id) const;
+	std::string currentGameTitle() const;
+	std::string currentGameSubtitle() const;
+	std::string formatPercent(float value) const;
+	std::string formatInteger(int value) const;
+	std::string formatTitleId(std::uint64_t program_id) const;
+	void openFileAndLaunch();
+	void requestLaunchPath(const std::filesystem::path& path);
+	void requestClassicUi(bool open_settings);
+	void openUnsupportedPrompt(std::string title, std::string message) const;
+
+	SDL_Window* window = nullptr;
+	Emulator& emu;
+	fsui::UiContext fsuiContext;
+	fsui::UiState uiState;
+	std::vector<fsui::GameEntry> cachedGameList;
+	std::optional<std::filesystem::path> pendingLaunchPath;
+	bool closeSelectorRequested = false;
+	ClassicUiRequest pendingClassicUiRequest = ClassicUiRequest::None;
+	std::function<void(bool)> onPauseChange;
+	std::function<void(bool)> onVsyncChange;
+	std::function<void()> onExitToSelector;
+};
+
+#endif