/*************************************************************************/
/*  main.cpp                                                             */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/

#include "main.h"

#include "core/config/project_settings.h"
#include "core/core_globals.h"
#include "core/core_string_names.h"
#include "core/crypto/crypto.h"
#include "core/debugger/engine_debugger.h"
#include "core/extension/extension_api_dump.h"
#include "core/extension/gdnative_interface_dump.gen.h"
#include "core/extension/native_extension_manager.h"
#include "core/input/input.h"
#include "core/input/input_map.h"
#include "core/io/dir_access.h"
#include "core/io/file_access_network.h"
#include "core/io/file_access_pack.h"
#include "core/io/file_access_zip.h"
#include "core/io/image_loader.h"
#include "core/io/ip.h"
#include "core/io/resource_loader.h"
#include "core/object/message_queue.h"
#include "core/os/os.h"
#include "core/os/time.h"
#include "core/register_core_types.h"
#include "core/string/translation.h"
#include "core/version.h"
#include "drivers/register_driver_types.h"
#include "main/app_icon.gen.h"
#include "main/main_timer_sync.h"
#include "main/performance.h"
#include "main/splash.gen.h"
#include "modules/register_module_types.h"
#include "platform/register_platform_apis.h"
#include "scene/main/scene_tree.h"
#include "scene/main/window.h"
#include "scene/register_scene_types.h"
#include "scene/resources/packed_scene.h"
#include "scene/theme/theme_db.h"
#include "servers/audio_server.h"
#include "servers/camera_server.h"
#include "servers/display_server.h"
#include "servers/movie_writer/movie_writer.h"
#include "servers/movie_writer/movie_writer_mjpeg.h"
#include "servers/navigation_server_2d.h"
#include "servers/navigation_server_3d.h"
#include "servers/physics_server_2d.h"
#include "servers/physics_server_3d.h"
#include "servers/register_server_types.h"
#include "servers/rendering/rendering_server_default.h"
#include "servers/text/text_server_dummy.h"
#include "servers/text_server.h"
#include "servers/xr_server.h"

#ifdef TESTS_ENABLED
#include "tests/test_main.h"
#endif

#ifdef TOOLS_ENABLED
#include "editor/debugger/editor_debugger_node.h"
#include "editor/doc_data_class_path.gen.h"
#include "editor/doc_tools.h"
#include "editor/editor_node.h"
#include "editor/editor_paths.h"
#include "editor/editor_settings.h"
#include "editor/editor_translation.h"
#include "editor/progress_dialog.h"
#include "editor/project_converter_3_to_4.h"
#include "editor/project_manager.h"
#include "editor/register_editor_types.h"
#ifndef NO_EDITOR_SPLASH
#include "main/splash_editor.gen.h"
#endif
#endif

#include "modules/modules_enabled.gen.h" // For mono.

/* Static members */

// Singletons

// Initialized in setup()
static Engine *engine = nullptr;
static ProjectSettings *globals = nullptr;
static Input *input = nullptr;
static InputMap *input_map = nullptr;
static TranslationServer *translation_server = nullptr;
static Performance *performance = nullptr;
static PackedData *packed_data = nullptr;
static Time *time_singleton = nullptr;
#ifdef MINIZIP_ENABLED
static ZipArchive *zip_packed_data = nullptr;
#endif
static FileAccessNetworkClient *file_access_network_client = nullptr;
static MessageQueue *message_queue = nullptr;

// Initialized in setup2()
static AudioServer *audio_server = nullptr;
static DisplayServer *display_server = nullptr;
static RenderingServer *rendering_server = nullptr;
static CameraServer *camera_server = nullptr;
static XRServer *xr_server = nullptr;
static TextServerManager *tsman = nullptr;
static PhysicsServer3DManager *physics_server_3d_manager = nullptr;
static PhysicsServer3D *physics_server_3d = nullptr;
static PhysicsServer2DManager *physics_server_2d_manager = nullptr;
static PhysicsServer2D *physics_server_2d = nullptr;
static NavigationServer3D *navigation_server_3d = nullptr;
static NavigationServer2D *navigation_server_2d = nullptr;
static ThemeDB *theme_db = nullptr;
// We error out if setup2() doesn't turn this true
static bool _start_success = false;

// Drivers

String tablet_driver = "";
String text_driver = "";
String rendering_driver = "";
String rendering_method = "";
static int text_driver_idx = -1;
static int display_driver_idx = -1;
static int audio_driver_idx = -1;

// Engine config/tools

static bool single_window = false;
static bool editor = false;
static bool project_manager = false;
static bool cmdline_tool = false;
static String locale;
static bool show_help = false;
static bool auto_quit = false;
static OS::ProcessID editor_pid = 0;
#ifdef TOOLS_ENABLED
static bool found_project = false;
static bool auto_build_solutions = false;
static String debug_server_uri;
static int converter_max_kb_file = 4 * 1024; // 4MB
static int converter_max_line_length = 100000;

HashMap<Main::CLIScope, Vector<String>> forwardable_cli_arguments;
#endif
bool use_startup_benchmark = false;
String startup_benchmark_file;

// Display

static DisplayServer::WindowMode window_mode = DisplayServer::WINDOW_MODE_WINDOWED;
static DisplayServer::ScreenOrientation window_orientation = DisplayServer::SCREEN_LANDSCAPE;
static DisplayServer::VSyncMode window_vsync_mode = DisplayServer::VSYNC_ENABLED;
static uint32_t window_flags = 0;
static Size2i window_size = Size2i(1152, 648);

static int init_screen = -1;
static bool init_fullscreen = false;
static bool init_maximized = false;
static bool init_windowed = false;
static bool init_always_on_top = false;
static bool init_use_custom_pos = false;
static Vector2 init_custom_pos;

// Debug

static bool use_debug_profiler = false;
#ifdef DEBUG_ENABLED
static bool debug_collisions = false;
static bool debug_paths = false;
static bool debug_navigation = false;
#endif
static int frame_delay = 0;
static bool disable_render_loop = false;
static int fixed_fps = -1;
static MovieWriter *movie_writer = nullptr;
static bool disable_vsync = false;
static bool print_fps = false;
#ifdef TOOLS_ENABLED
static bool dump_gdnative_interface = false;
static bool dump_extension_api = false;
#endif
bool profile_gpu = false;

/* Helper methods */

bool Main::is_cmdline_tool() {
	return cmdline_tool;
}

#ifdef TOOLS_ENABLED
const Vector<String> &Main::get_forwardable_cli_arguments(Main::CLIScope p_scope) {
	return forwardable_cli_arguments[p_scope];
}
#endif

static String unescape_cmdline(const String &p_str) {
	return p_str.replace("%20", " ");
}

static String get_full_version_string() {
	String hash = String(VERSION_HASH);
	if (!hash.is_empty()) {
		hash = "." + hash.left(9);
	}
	return String(VERSION_FULL_BUILD) + hash;
}

// FIXME: Could maybe be moved to have less code in main.cpp.
void initialize_physics() {
	/// 3D Physics Server
	physics_server_3d = PhysicsServer3DManager::get_singleton()->new_server(
			GLOBAL_GET(PhysicsServer3DManager::setting_property_name));
	if (!physics_server_3d) {
		// Physics server not found, Use the default physics
		physics_server_3d = PhysicsServer3DManager::get_singleton()->new_default_server();
	}
	ERR_FAIL_COND(!physics_server_3d);
	physics_server_3d->init();

	// 2D Physics server
	physics_server_2d = PhysicsServer2DManager::get_singleton()->new_server(
			GLOBAL_GET(PhysicsServer2DManager::get_singleton()->setting_property_name));
	if (!physics_server_2d) {
		// Physics server not found, Use the default physics
		physics_server_2d = PhysicsServer2DManager::get_singleton()->new_default_server();
	}
	ERR_FAIL_COND(!physics_server_2d);
	physics_server_2d->init();
}

void finalize_physics() {
	physics_server_3d->finish();
	memdelete(physics_server_3d);

	physics_server_2d->finish();
	memdelete(physics_server_2d);
}

void finalize_display() {
	rendering_server->finish();
	memdelete(rendering_server);

	memdelete(display_server);
}

void initialize_navigation_server() {
	ERR_FAIL_COND(navigation_server_3d != nullptr);

	navigation_server_3d = NavigationServer3DManager::new_default_server();
	navigation_server_2d = memnew(NavigationServer2D);
}

void finalize_navigation_server() {
	memdelete(navigation_server_3d);
	navigation_server_3d = nullptr;

	memdelete(navigation_server_2d);
	navigation_server_2d = nullptr;
}

void initialize_theme_db() {
	theme_db = memnew(ThemeDB);
	theme_db->initialize_theme();
}

void finalize_theme_db() {
	memdelete(theme_db);
	theme_db = nullptr;
}

//#define DEBUG_INIT
#ifdef DEBUG_INIT
#define MAIN_PRINT(m_txt) print_line(m_txt)
#else
#define MAIN_PRINT(m_txt)
#endif

void Main::print_help(const char *p_binary) {
	print_line(String(VERSION_NAME) + " v" + get_full_version_string() + " - " + String(VERSION_WEBSITE));
	OS::get_singleton()->print("Free and open source software under the terms of the MIT license.\n");
	OS::get_singleton()->print("(c) 2007-2022 Juan Linietsky, Ariel Manzur.\n");
	OS::get_singleton()->print("(c) 2014-2022 Godot Engine contributors.\n");
	OS::get_singleton()->print("\n");
	OS::get_singleton()->print("Usage: %s [options] [path to scene or 'project.godot' file]\n", p_binary);
	OS::get_singleton()->print("\n");

	OS::get_singleton()->print("General options:\n");
	OS::get_singleton()->print("  -h, --help                                   Display this help message.\n");
	OS::get_singleton()->print("  --version                                    Display the version string.\n");
	OS::get_singleton()->print("  -v, --verbose                                Use verbose stdout mode.\n");
	OS::get_singleton()->print("  -q, --quiet                                  Quiet mode, silences stdout messages. Errors are still displayed.\n");
	OS::get_singleton()->print("\n");

	OS::get_singleton()->print("Run options:\n");
	OS::get_singleton()->print("  --, ++                                       Separator for user-provided arguments. Following arguments are not used by the engine, but can be read from `OS.get_cmdline_user_args()`.\n");
#ifdef TOOLS_ENABLED
	OS::get_singleton()->print("  -e, --editor                                 Start the editor instead of running the scene.\n");
	OS::get_singleton()->print("  -p, --project-manager                        Start the project manager, even if a project is auto-detected.\n");
	OS::get_singleton()->print("  --debug-server <uri>                         Start the editor debug server (<protocol>://<host/IP>[:<port>], e.g. tcp://127.0.0.1:6007)\n");
#endif
	OS::get_singleton()->print("  --quit                                       Quit after the first iteration.\n");
	OS::get_singleton()->print("  -l, --language <locale>                      Use a specific locale (<locale> being a two-letter code).\n");
	OS::get_singleton()->print("  --path <directory>                           Path to a project (<directory> must contain a 'project.godot' file).\n");
	OS::get_singleton()->print("  -u, --upwards                                Scan folders upwards for project.godot file.\n");
	OS::get_singleton()->print("  --main-pack <file>                           Path to a pack (.pck) file to load.\n");
	OS::get_singleton()->print("  --render-thread <mode>                       Render thread mode ('unsafe', 'safe', 'separate').\n");
	OS::get_singleton()->print("  --remote-fs <address>                        Remote filesystem (<host/IP>[:<port>] address).\n");
	OS::get_singleton()->print("  --remote-fs-password <password>              Password for remote filesystem.\n");

	OS::get_singleton()->print("  --audio-driver <driver>                      Audio driver [");
	for (int i = 0; i < AudioDriverManager::get_driver_count(); i++) {
		if (i > 0) {
			OS::get_singleton()->print(", ");
		}
		OS::get_singleton()->print("'%s'", AudioDriverManager::get_driver(i)->get_name());
	}
	OS::get_singleton()->print("].\n");

	OS::get_singleton()->print("  --display-driver <driver>                    Display driver (and rendering driver) [");
	for (int i = 0; i < DisplayServer::get_create_function_count(); i++) {
		if (i > 0) {
			OS::get_singleton()->print(", ");
		}
		OS::get_singleton()->print("'%s' (", DisplayServer::get_create_function_name(i));
		Vector<String> rd = DisplayServer::get_create_function_rendering_drivers(i);
		for (int j = 0; j < rd.size(); j++) {
			if (j > 0) {
				OS::get_singleton()->print(", ");
			}
			OS::get_singleton()->print("'%s'", rd[j].utf8().get_data());
		}
		OS::get_singleton()->print(")");
	}
	OS::get_singleton()->print("].\n");

	OS::get_singleton()->print("  --rendering-method <renderer>                   Renderer name. Requires driver support.\n");
	OS::get_singleton()->print("  --rendering-driver <driver>                  Rendering driver (depends on display driver).\n");
	OS::get_singleton()->print("  --gpu-index <device_index>                   Use a specific GPU (run with --verbose to get available device list).\n");
	OS::get_singleton()->print("  --text-driver <driver>                       Text driver (Fonts, BiDi, shaping)\n");
	OS::get_singleton()->print("  --tablet-driver <driver>                     Pen tablet input driver.\n");
	OS::get_singleton()->print("  --headless                                   Enable headless mode (--display-driver headless --audio-driver Dummy). Useful for servers and with --script.\n");
	OS::get_singleton()->print("  --write-movie <file>                         Run the engine in a way that a movie is written (by default .avi MJPEG). Fixed FPS is forced when enabled, but can be used to change movie FPS. Disabling vsync can speed up movie writing but makes interaction more difficult.\n");
	OS::get_singleton()->print("  --disable-vsync                              Force disabling of vsync. Run the engine in a way that a movie is written (by default .avi MJPEG). Fixed FPS is forced when enabled, but can be used to change movie FPS.\n");

	OS::get_singleton()->print("\n");

	OS::get_singleton()->print("Display options:\n");
	OS::get_singleton()->print("  -f, --fullscreen                             Request fullscreen mode.\n");
	OS::get_singleton()->print("  -m, --maximized                              Request a maximized window.\n");
	OS::get_singleton()->print("  -w, --windowed                               Request windowed mode.\n");
	OS::get_singleton()->print("  -t, --always-on-top                          Request an always-on-top window.\n");
	OS::get_singleton()->print("  --resolution <W>x<H>                         Request window resolution.\n");
	OS::get_singleton()->print("  --position <X>,<Y>                           Request window position.\n");
	OS::get_singleton()->print("  --single-window                              Use a single window (no separate subwindows).\n");
	OS::get_singleton()->print("  --xr-mode <mode>                             Select XR mode (default/off/on).\n");
	OS::get_singleton()->print("\n");

	OS::get_singleton()->print("Debug options:\n");
	OS::get_singleton()->print("  -d, --debug                                  Debug (local stdout debugger).\n");
	OS::get_singleton()->print("  -b, --breakpoints                            Breakpoint list as source::line comma-separated pairs, no spaces (use %%20 instead).\n");
	OS::get_singleton()->print("  --profiling                                  Enable profiling in the script debugger.\n");
	OS::get_singleton()->print("  --gpu-profile                                Show a GPU profile of the tasks that took the most time during frame rendering.\n");
	OS::get_singleton()->print("  --gpu-validation                             Enable graphics API validation layers for debugging.\n");
#if DEBUG_ENABLED
	OS::get_singleton()->print("  --gpu-abort                                  Abort on graphics API usage errors (usually validation layer errors). May help see the problem if your system freezes.\n");
#endif
	OS::get_singleton()->print("  --remote-debug <uri>                         Remote debug (<protocol>://<host/IP>[:<port>], e.g. tcp://127.0.0.1:6007).\n");
#if defined(DEBUG_ENABLED)
	OS::get_singleton()->print("  --debug-collisions                           Show collision shapes when running the scene.\n");
	OS::get_singleton()->print("  --debug-paths                                Show path lines when running the scene.\n");
	OS::get_singleton()->print("  --debug-navigation                           Show navigation polygons when running the scene.\n");
	OS::get_singleton()->print("  --debug-stringnames                          Print all StringName allocations to stdout when the engine quits.\n");
#endif
	OS::get_singleton()->print("  --frame-delay <ms>                           Simulate high CPU load (delay each frame by <ms> milliseconds).\n");
	OS::get_singleton()->print("  --time-scale <scale>                         Force time scale (higher values are faster, 1.0 is normal speed).\n");
	OS::get_singleton()->print("  --disable-render-loop                        Disable render loop so rendering only occurs when called explicitly from script.\n");
	OS::get_singleton()->print("  --disable-crash-handler                      Disable crash handler when supported by the platform code.\n");
	OS::get_singleton()->print("  --fixed-fps <fps>                            Force a fixed number of frames per second. This setting disables real-time synchronization.\n");
	OS::get_singleton()->print("  --print-fps                                  Print the frames per second to the stdout.\n");
	OS::get_singleton()->print("\n");

	OS::get_singleton()->print("Standalone tools:\n");
	OS::get_singleton()->print("  -s, --script <script>                        Run a script.\n");
	OS::get_singleton()->print("  --check-only                                 Only parse for errors and quit (use with --script).\n");
#ifdef TOOLS_ENABLED
	OS::get_singleton()->print("  --export-release <preset> <path>             Export the project in release mode using the given preset and output path. The preset name should match one defined in export_presets.cfg.\n");
	OS::get_singleton()->print("                                               <path> should be absolute or relative to the project directory, and include the filename for the binary (e.g. 'builds/game.exe').\n");
	OS::get_singleton()->print("                                               The target directory must exist.\n");
	OS::get_singleton()->print("  --export-debug <preset> <path>               Export the project in debug mode using the given preset and output path. The preset name should match one defined in export_presets.cfg.\n");
	OS::get_singleton()->print("  --export-pack <preset> <path>                Export the project data only using the given preset and output path. The <path> extension determines whether it will be in PCK or ZIP format.\n");
	OS::get_singleton()->print("  --convert-3to4 [<max_file_kb>] [<max_line_size>]              Converts project from Godot 3.x to Godot 4.x.\n");
	OS::get_singleton()->print("  --validate-conversion-3to4 [<max_file_kb>] [<max_line_size>]  Shows what elements will be renamed when converting project from Godot 3.x to Godot 4.x.\n");
	OS::get_singleton()->print("  --doctool [<path>]                           Dump the engine API reference to the given <path> (defaults to current dir) in XML format, merging if existing files are found.\n");
	OS::get_singleton()->print("  --no-docbase                                 Disallow dumping the base types (used with --doctool).\n");
	OS::get_singleton()->print("  --build-solutions                            Build the scripting solutions (e.g. for C# projects). Implies --editor and requires a valid project to edit.\n");
	OS::get_singleton()->print("  --dump-gdextension-interface                 Generate GDExtension header file 'gdnative_interface.h' in the current folder. This file is the base file required to implement a GDExtension.\n");
	OS::get_singleton()->print("  --dump-extension-api                         Generate JSON dump of the Godot API for GDExtension bindings named 'extension_api.json' in the current folder.\n");
	OS::get_singleton()->print("  --startup-benchmark                          Benchmark the startup time and print it to console.\n");
	OS::get_singleton()->print("  --startup-benchmark-file <path>              Benchmark the startup time and save it to a given file in JSON format.\n");
#ifdef TESTS_ENABLED
	OS::get_singleton()->print("  --test [--help]                              Run unit tests. Use --test --help for more information.\n");
#endif
#endif
	OS::get_singleton()->print("\n");
}

#ifdef TESTS_ENABLED
// The order is the same as in `Main::setup()`, only core and some editor types
// are initialized here. This also combines `Main::setup2()` initialization.
Error Main::test_setup() {
	OS::get_singleton()->initialize();

	engine = memnew(Engine);

	register_core_types();
	register_core_driver_types();

	packed_data = memnew(PackedData);

	globals = memnew(ProjectSettings);

	register_core_settings(); // Here globals are present.

	translation_server = memnew(TranslationServer);
	tsman = memnew(TextServerManager);

	if (tsman) {
		Ref<TextServerDummy> ts;
		ts.instantiate();
		tsman->add_interface(ts);
	}

	physics_server_3d_manager = memnew(PhysicsServer3DManager);
	physics_server_2d_manager = memnew(PhysicsServer2DManager);

	// From `Main::setup2()`.
	initialize_modules(MODULE_INITIALIZATION_LEVEL_CORE);
	register_core_extensions();

	register_core_singletons();

	/** INITIALIZE SERVERS **/
	register_server_types();
	XRServer::set_xr_mode(XRServer::XRMODE_OFF); // Skip in tests.
	initialize_modules(MODULE_INITIALIZATION_LEVEL_SERVERS);
	NativeExtensionManager::get_singleton()->initialize_extensions(NativeExtension::INITIALIZATION_LEVEL_SERVERS);

	translation_server->setup(); //register translations, load them, etc.
	if (!locale.is_empty()) {
		translation_server->set_locale(locale);
	}
	translation_server->load_translations();
	ResourceLoader::load_translation_remaps(); //load remaps for resources

	ResourceLoader::load_path_remaps();

	register_scene_types();
	register_driver_types();

	initialize_modules(MODULE_INITIALIZATION_LEVEL_SCENE);
	NativeExtensionManager::get_singleton()->initialize_extensions(NativeExtension::INITIALIZATION_LEVEL_SCENE);

#ifdef TOOLS_ENABLED
	ClassDB::set_current_api(ClassDB::API_EDITOR);
	register_editor_types();

	initialize_modules(MODULE_INITIALIZATION_LEVEL_EDITOR);
	NativeExtensionManager::get_singleton()->initialize_extensions(NativeExtension::INITIALIZATION_LEVEL_EDITOR);

	ClassDB::set_current_api(ClassDB::API_CORE);
#endif
	register_platform_apis();

	// Theme needs modules to be initialized so that sub-resources can be loaded.
	initialize_theme_db();
	register_scene_singletons();

	ERR_FAIL_COND_V(TextServerManager::get_singleton()->get_interface_count() == 0, ERR_CANT_CREATE);

	/* Use one with the most features available. */
	int max_features = 0;
	for (int i = 0; i < TextServerManager::get_singleton()->get_interface_count(); i++) {
		uint32_t features = TextServerManager::get_singleton()->get_interface(i)->get_features();
		int feature_number = 0;
		while (features) {
			feature_number += features & 1;
			features >>= 1;
		}
		if (feature_number >= max_features) {
			max_features = feature_number;
			text_driver_idx = i;
		}
	}
	if (text_driver_idx >= 0) {
		TextServerManager::get_singleton()->set_primary_interface(TextServerManager::get_singleton()->get_interface(text_driver_idx));
	} else {
		ERR_FAIL_V_MSG(ERR_CANT_CREATE, "TextServer: Unable to create TextServer interface.");
	}

	ClassDB::set_current_api(ClassDB::API_NONE);

	_start_success = true;

	return OK;
}
// The order is the same as in `Main::cleanup()`.
void Main::test_cleanup() {
	ERR_FAIL_COND(!_start_success);

	EngineDebugger::deinitialize();

	ResourceLoader::remove_custom_loaders();
	ResourceSaver::remove_custom_savers();

#ifdef TOOLS_ENABLED
	NativeExtensionManager::get_singleton()->deinitialize_extensions(NativeExtension::INITIALIZATION_LEVEL_EDITOR);
	uninitialize_modules(MODULE_INITIALIZATION_LEVEL_EDITOR);
	unregister_editor_types();
#endif

	NativeExtensionManager::get_singleton()->deinitialize_extensions(NativeExtension::INITIALIZATION_LEVEL_SCENE);
	uninitialize_modules(MODULE_INITIALIZATION_LEVEL_SCENE);
	unregister_platform_apis();
	unregister_driver_types();
	unregister_scene_types();

	finalize_theme_db();

	NativeExtensionManager::get_singleton()->deinitialize_extensions(NativeExtension::INITIALIZATION_LEVEL_SERVERS);
	uninitialize_modules(MODULE_INITIALIZATION_LEVEL_SERVERS);
	unregister_server_types();

	OS::get_singleton()->finalize();

	if (translation_server) {
		memdelete(translation_server);
	}
	if (tsman) {
		memdelete(tsman);
	}
	if (physics_server_3d_manager) {
		memdelete(physics_server_3d_manager);
	}
	if (physics_server_2d_manager) {
		memdelete(physics_server_2d_manager);
	}
	if (globals) {
		memdelete(globals);
	}
	if (packed_data) {
		memdelete(packed_data);
	}
	if (engine) {
		memdelete(engine);
	}

	unregister_core_driver_types();
	uninitialize_modules(MODULE_INITIALIZATION_LEVEL_CORE);
	unregister_core_extensions();
	unregister_core_types();

	OS::get_singleton()->finalize_core();
}
#endif

int Main::test_entrypoint(int argc, char *argv[], bool &tests_need_run) {
#ifdef TESTS_ENABLED
	for (int x = 0; x < argc; x++) {
		if ((strncmp(argv[x], "--test", 6) == 0) && (strlen(argv[x]) == 6)) {
			tests_need_run = true;
			// TODO: need to come up with different test contexts.
			// Not every test requires high-level functionality like `ClassDB`.
			test_setup();
			int status = test_main(argc, argv);
			test_cleanup();
			return status;
		}
	}
#endif
	tests_need_run = false;
	return 0;
}

/* Engine initialization
 *
 * Consists of several methods that are called by each platform's specific main(argc, argv).
 * To fully understand engine init, one should therefore start from the platform's main and
 * see how it calls into the Main class' methods.
 *
 * The initialization is typically done in 3 steps (with the setup2 step triggered either
 * automatically by setup, or manually in the platform's main).
 *
 * - setup(execpath, argc, argv, p_second_phase) is the main entry point for all platforms,
 *   responsible for the initialization of all low level singletons and core types, and parsing
 *   command line arguments to configure things accordingly.
 *   If p_second_phase is true, it will chain into setup2() (default behavior). This is
 *   disabled on some platforms (Android, iOS, UWP) which trigger the second step in their
 *   own time.
 *
 * - setup2(p_main_tid_override) registers high level servers and singletons, displays the
 *   boot splash, then registers higher level types (scene, editor, etc.).
 *
 * - start() is the last step and that's where command line tools can run, or the main loop
 *   can be created eventually and the project settings put into action. That's also where
 *   the editor node is created, if relevant.
 *   start() does it own argument parsing for a subset of the command line arguments described
 *   in help, it's a bit messy and should be globalized with the setup() parsing somehow.
 */

Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_phase) {
	OS::get_singleton()->initialize();

	engine = memnew(Engine);

	MAIN_PRINT("Main: Initialize CORE");
	engine->startup_begin();
	engine->startup_benchmark_begin_measure("core");

	register_core_types();
	register_core_driver_types();

	MAIN_PRINT("Main: Initialize Globals");

	input_map = memnew(InputMap);
	time_singleton = memnew(Time);
	globals = memnew(ProjectSettings);

	register_core_settings(); //here globals are present

	translation_server = memnew(TranslationServer);
	performance = memnew(Performance);
	GDREGISTER_CLASS(Performance);
	engine->add_singleton(Engine::Singleton("Performance", performance));

	// Only flush stdout in debug builds by default, as spamming `print()` will
	// decrease performance if this is enabled.
	GLOBAL_DEF_RST("application/run/flush_stdout_on_print", false);
	GLOBAL_DEF_RST("application/run/flush_stdout_on_print.debug", true);

	MAIN_PRINT("Main: Parse CMDLine");

	/* argument parsing and main creation */
	List<String> args;
	List<String> main_args;
	List<String> user_args;
	bool adding_user_args = false;
	List<String> platform_args = OS::get_singleton()->get_cmdline_platform_args();

	// Add command line arguments.
	for (int i = 0; i < argc; i++) {
		args.push_back(String::utf8(argv[i]));
	}

	// Add arguments received from macOS LaunchService (URL schemas, file associations).
	for (const String &arg : platform_args) {
		args.push_back(arg);
	}

	List<String>::Element *I = args.front();

	while (I) {
		I->get() = unescape_cmdline(I->get().strip_edges());
		I = I->next();
	}

	String display_driver = "";
	String audio_driver = "";
	String project_path = ".";
	bool upwards = false;
	String debug_uri = "";
	bool skip_breakpoints = false;
	String main_pack;
	bool quiet_stdout = false;
	int rtm = -1;

	String remotefs;
	String remotefs_pass;

	Vector<String> breakpoints;
	bool use_custom_res = true;
	bool force_res = false;

	String default_renderer = "";
	String default_renderer_mobile = "";
	String renderer_hints = "";

	packed_data = PackedData::get_singleton();
	if (!packed_data) {
		packed_data = memnew(PackedData);
	}

#ifdef MINIZIP_ENABLED

	//XXX: always get_singleton() == 0x0
	zip_packed_data = ZipArchive::get_singleton();
	//TODO: remove this temporary fix
	if (!zip_packed_data) {
		zip_packed_data = memnew(ZipArchive);
	}

	packed_data->add_pack_source(zip_packed_data);
#endif

	// Default exit code, can be modified for certain errors.
	Error exit_code = ERR_INVALID_PARAMETER;

	I = args.front();
	while (I) {
#ifdef MACOS_ENABLED
		// Ignore the process serial number argument passed by macOS Gatekeeper.
		// Otherwise, Godot would try to open a non-existent project on the first start and abort.
		if (I->get().begins_with("-psn_")) {
			I = I->next();
			continue;
		}
#endif

		List<String>::Element *N = I->next();

#ifdef TOOLS_ENABLED
		if (I->get() == "--debug" ||
				I->get() == "--verbose" ||
				I->get() == "--disable-crash-handler") {
			forwardable_cli_arguments[CLI_SCOPE_TOOL].push_back(I->get());
			forwardable_cli_arguments[CLI_SCOPE_PROJECT].push_back(I->get());
		}
		if (I->get() == "--single-window") {
			forwardable_cli_arguments[CLI_SCOPE_TOOL].push_back(I->get());
		}
		if (I->get() == "--audio-driver" ||
				I->get() == "--display-driver" ||
				I->get() == "--rendering-method" ||
				I->get() == "--rendering-driver") {
			if (I->next()) {
				forwardable_cli_arguments[CLI_SCOPE_TOOL].push_back(I->get());
				forwardable_cli_arguments[CLI_SCOPE_TOOL].push_back(I->next()->get());
			}
		}
#endif

		if (adding_user_args) {
			user_args.push_back(I->get());
		} else if (I->get() == "-h" || I->get() == "--help" || I->get() == "/?") { // display help

			show_help = true;
			exit_code = ERR_HELP; // Hack to force an early exit in `main()` with a success code.
			goto error;

		} else if (I->get() == "--version") {
			print_line(get_full_version_string());
			exit_code = ERR_HELP; // Hack to force an early exit in `main()` with a success code.
			goto error;

		} else if (I->get() == "-v" || I->get() == "--verbose") { // verbose output

			OS::get_singleton()->_verbose_stdout = true;
		} else if (I->get() == "-q" || I->get() == "--quiet") { // quieter output

			quiet_stdout = true;

		} else if (I->get() == "--audio-driver") { // audio driver

			if (I->next()) {
				audio_driver = I->next()->get();

				bool found = false;
				for (int i = 0; i < AudioDriverManager::get_driver_count(); i++) {
					if (audio_driver == AudioDriverManager::get_driver(i)->get_name()) {
						found = true;
					}
				}

				if (!found) {
					OS::get_singleton()->print("Unknown audio driver '%s', aborting.\nValid options are ",
							audio_driver.utf8().get_data());

					for (int i = 0; i < AudioDriverManager::get_driver_count(); i++) {
						if (i == AudioDriverManager::get_driver_count() - 1) {
							OS::get_singleton()->print(" and ");
						} else if (i != 0) {
							OS::get_singleton()->print(", ");
						}

						OS::get_singleton()->print("'%s'", AudioDriverManager::get_driver(i)->get_name());
					}

					OS::get_singleton()->print(".\n");

					goto error;
				}

				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing audio driver argument, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--text-driver") {
			if (I->next()) {
				text_driver = I->next()->get();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing text driver argument, aborting.\n");
				goto error;
			}

		} else if (I->get() == "--display-driver") { // force video driver

			if (I->next()) {
				display_driver = I->next()->get();

				bool found = false;
				for (int i = 0; i < DisplayServer::get_create_function_count(); i++) {
					if (display_driver == DisplayServer::get_create_function_name(i)) {
						found = true;
					}
				}

				if (!found) {
					OS::get_singleton()->print("Unknown display driver '%s', aborting.\nValid options are ",
							display_driver.utf8().get_data());

					for (int i = 0; i < DisplayServer::get_create_function_count(); i++) {
						if (i == DisplayServer::get_create_function_count() - 1) {
							OS::get_singleton()->print(" and ");
						} else if (i != 0) {
							OS::get_singleton()->print(", ");
						}

						OS::get_singleton()->print("'%s'", DisplayServer::get_create_function_name(i));
					}

					OS::get_singleton()->print(".\n");

					goto error;
				}

				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing display driver argument, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--rendering-method") {
			if (I->next()) {
				rendering_method = I->next()->get();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing renderer name argument, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--rendering-driver") {
			if (I->next()) {
				rendering_driver = I->next()->get();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing rendering driver argument, aborting.\n");
				goto error;
			}
		} else if (I->get() == "-f" || I->get() == "--fullscreen") { // force fullscreen

			init_fullscreen = true;
		} else if (I->get() == "-m" || I->get() == "--maximized") { // force maximized window

			init_maximized = true;
			window_mode = DisplayServer::WINDOW_MODE_MAXIMIZED;

		} else if (I->get() == "-w" || I->get() == "--windowed") { // force windowed window

			init_windowed = true;
		} else if (I->get() == "--gpu-index") {
			if (I->next()) {
				Engine::singleton->gpu_idx = I->next()->get().to_int();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing GPU index argument, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--gpu-validation") {
			Engine::singleton->use_validation_layers = true;
#ifdef DEBUG_ENABLED
		} else if (I->get() == "--gpu-abort") {
			Engine::singleton->abort_on_gpu_errors = true;
#endif
		} else if (I->get() == "--tablet-driver") {
			if (I->next()) {
				tablet_driver = I->next()->get();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing tablet driver argument, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--single-window") { // force single window

			single_window = true;
		} else if (I->get() == "-t" || I->get() == "--always-on-top") { // force always-on-top window

			init_always_on_top = true;
		} else if (I->get() == "--resolution") { // force resolution

			if (I->next()) {
				String vm = I->next()->get();

				if (!vm.contains("x")) { // invalid parameter format

					OS::get_singleton()->print("Invalid resolution '%s', it should be e.g. '1280x720'.\n",
							vm.utf8().get_data());
					goto error;
				}

				int w = vm.get_slice("x", 0).to_int();
				int h = vm.get_slice("x", 1).to_int();

				if (w <= 0 || h <= 0) {
					OS::get_singleton()->print("Invalid resolution '%s', width and height must be above 0.\n",
							vm.utf8().get_data());
					goto error;
				}

				window_size.width = w;
				window_size.height = h;
				force_res = true;

				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing resolution argument, aborting.\n");
				goto error;
			}

		} else if (I->get() == "--position") { // set window position

			if (I->next()) {
				String vm = I->next()->get();

				if (!vm.contains(",")) { // invalid parameter format

					OS::get_singleton()->print("Invalid position '%s', it should be e.g. '80,128'.\n",
							vm.utf8().get_data());
					goto error;
				}

				int x = vm.get_slice(",", 0).to_int();
				int y = vm.get_slice(",", 1).to_int();

				init_custom_pos = Point2(x, y);
				init_use_custom_pos = true;

				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing position argument, aborting.\n");
				goto error;
			}

		} else if (I->get() == "--headless") { // enable headless mode (no audio, no rendering).

			audio_driver = "Dummy";
			display_driver = "headless";

		} else if (I->get() == "--profiling") { // enable profiling

			use_debug_profiler = true;

		} else if (I->get() == "-l" || I->get() == "--language") { // language

			if (I->next()) {
				locale = I->next()->get();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing language argument, aborting.\n");
				goto error;
			}

		} else if (I->get() == "--remote-fs") { // remote filesystem

			if (I->next()) {
				remotefs = I->next()->get();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing remote filesystem address, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--remote-fs-password") { // remote filesystem password

			if (I->next()) {
				remotefs_pass = I->next()->get();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing remote filesystem password, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--render-thread") { // render thread mode

			if (I->next()) {
				if (I->next()->get() == "safe") {
					rtm = OS::RENDER_THREAD_SAFE;
				} else if (I->next()->get() == "unsafe") {
					rtm = OS::RENDER_THREAD_UNSAFE;
				} else if (I->next()->get() == "separate") {
					rtm = OS::RENDER_SEPARATE_THREAD;
				}

				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing render thread mode argument, aborting.\n");
				goto error;
			}
#ifdef TOOLS_ENABLED
		} else if (I->get() == "-e" || I->get() == "--editor") { // starts editor

			editor = true;
		} else if (I->get() == "-p" || I->get() == "--project-manager") { // starts project manager
			project_manager = true;
		} else if (I->get() == "--debug-server") {
			if (I->next()) {
				debug_server_uri = I->next()->get();
				if (!debug_server_uri.contains("://")) { // wrong address
					OS::get_singleton()->print("Invalid debug server uri. It should be of the form <protocol>://<bind_address>:<port>.\n");
					goto error;
				}
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing remote debug server uri, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--build-solutions") { // Build the scripting solution such C#

			auto_build_solutions = true;
			editor = true;
			cmdline_tool = true;
		} else if (I->get() == "--dump-gdextension-interface") {
			// Register as an editor instance to use low-end fallback if relevant.
			editor = true;
			cmdline_tool = true;
			dump_gdnative_interface = true;
			print_line("Dumping gdnative interface header file");
			// Hack. Not needed but otherwise we end up detecting that this should
			// run the project instead of a cmdline tool.
			// Needs full refactoring to fix properly.
			main_args.push_back(I->get());
		} else if (I->get() == "--dump-extension-api") {
			// Register as an editor instance to use low-end fallback if relevant.
			editor = true;
			cmdline_tool = true;
			dump_extension_api = true;
			print_line("Dumping Extension API");
			// Hack. Not needed but otherwise we end up detecting that this should
			// run the project instead of a cmdline tool.
			// Needs full refactoring to fix properly.
			main_args.push_back(I->get());
		} else if (I->get() == "--export-release" || I->get() == "--export-debug" ||
				I->get() == "--export-pack") { // Export project
			// Actually handling is done in start().
			editor = true;
			cmdline_tool = true;
			main_args.push_back(I->get());
		} else if (I->get() == "--convert-3to4") {
			// Actually handling is done in start().
			cmdline_tool = true;
			main_args.push_back(I->get());

			if (I->next() && !I->next()->get().begins_with("-")) {
				if (itos(I->next()->get().to_int()) == I->next()->get()) {
					converter_max_kb_file = I->next()->get().to_int();
				}
				if (I->next()->next() && !I->next()->next()->get().begins_with("-")) {
					if (itos(I->next()->next()->get().to_int()) == I->next()->next()->get()) {
						converter_max_line_length = I->next()->next()->get().to_int();
					}
				}
			}
		} else if (I->get() == "--validate-conversion-3to4") {
			// Actually handling is done in start().
			cmdline_tool = true;
			main_args.push_back(I->get());

			if (I->next() && !I->next()->get().begins_with("-")) {
				if (itos(I->next()->get().to_int()) == I->next()->get()) {
					converter_max_kb_file = I->next()->get().to_int();
				}
				if (I->next()->next() && !I->next()->next()->get().begins_with("-")) {
					if (itos(I->next()->next()->get().to_int()) == I->next()->next()->get()) {
						converter_max_line_length = I->next()->next()->get().to_int();
					}
				}
			}
		} else if (I->get() == "--doctool") {
			// Actually handling is done in start().
			cmdline_tool = true;

			// `--doctool` implies `--headless` to avoid spawning an unnecessary window
			// and speed up class reference generation.
			audio_driver = "Dummy";
			display_driver = "headless";
			main_args.push_back(I->get());
#endif
		} else if (I->get() == "--path") { // set path of project to start or edit

			if (I->next()) {
				String p = I->next()->get();
				if (OS::get_singleton()->set_cwd(p) != OK) {
					OS::get_singleton()->print("Invalid project path specified: \"%s\", aborting.\n", p.utf8().get_data());
					goto error;
				}
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing relative or absolute path, aborting.\n");
				goto error;
			}
		} else if (I->get() == "-u" || I->get() == "--upwards") { // scan folders upwards
			upwards = true;
		} else if (I->get() == "--quit") { // Auto quit at the end of the first main loop iteration
			auto_quit = true;
		} else if (I->get().ends_with("project.godot")) {
			String path;
			String file = I->get();
			int sep = MAX(file.rfind("/"), file.rfind("\\"));
			if (sep == -1) {
				path = ".";
			} else {
				path = file.substr(0, sep);
			}
			if (OS::get_singleton()->set_cwd(path) == OK) {
				// path already specified, don't override
			} else {
				project_path = path;
			}
#ifdef TOOLS_ENABLED
			editor = true;
#endif
		} else if (I->get() == "-b" || I->get() == "--breakpoints") { // add breakpoints

			if (I->next()) {
				String bplist = I->next()->get();
				breakpoints = bplist.split(",");
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing list of breakpoints, aborting.\n");
				goto error;
			}

		} else if (I->get() == "--frame-delay") { // force frame delay

			if (I->next()) {
				frame_delay = I->next()->get().to_int();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing frame delay argument, aborting.\n");
				goto error;
			}

		} else if (I->get() == "--time-scale") { // force time scale

			if (I->next()) {
				Engine::get_singleton()->set_time_scale(I->next()->get().to_float());
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing time scale argument, aborting.\n");
				goto error;
			}

		} else if (I->get() == "--main-pack") {
			if (I->next()) {
				main_pack = I->next()->get();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing path to main pack file, aborting.\n");
				goto error;
			};

		} else if (I->get() == "-d" || I->get() == "--debug") {
			debug_uri = "local://";
			OS::get_singleton()->_debug_stdout = true;
#if defined(DEBUG_ENABLED)
		} else if (I->get() == "--debug-collisions") {
			debug_collisions = true;
		} else if (I->get() == "--debug-paths") {
			debug_paths = true;
		} else if (I->get() == "--debug-navigation") {
			debug_navigation = true;
		} else if (I->get() == "--debug-stringnames") {
			StringName::set_debug_stringnames(true);
#endif
		} else if (I->get() == "--remote-debug") {
			if (I->next()) {
				debug_uri = I->next()->get();
				if (!debug_uri.contains("://")) { // wrong address
					OS::get_singleton()->print(
							"Invalid debug host address, it should be of the form <protocol>://<host/IP>:<port>.\n");
					goto error;
				}
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing remote debug host address, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--editor-pid") { // not exposed to user
			if (I->next()) {
				editor_pid = I->next()->get().to_int();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing editor PID argument, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--disable-render-loop") {
			disable_render_loop = true;
		} else if (I->get() == "--fixed-fps") {
			if (I->next()) {
				fixed_fps = I->next()->get().to_int();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing fixed-fps argument, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--write-movie") {
			if (I->next()) {
				Engine::get_singleton()->set_write_movie_path(I->next()->get());
				N = I->next()->next();
				if (fixed_fps == -1) {
					fixed_fps = 60;
				}
				OS::get_singleton()->_writing_movie = true;
			} else {
				OS::get_singleton()->print("Missing write-movie argument, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--disable-vsync") {
			disable_vsync = true;
		} else if (I->get() == "--print-fps") {
			print_fps = true;
		} else if (I->get() == "--profile-gpu") {
			profile_gpu = true;
		} else if (I->get() == "--disable-crash-handler") {
			OS::get_singleton()->disable_crash_handler();
		} else if (I->get() == "--skip-breakpoints") {
			skip_breakpoints = true;
		} else if (I->get() == "--xr-mode") {
			if (I->next()) {
				String xr_mode = I->next()->get().to_lower();
				N = I->next()->next();
				if (xr_mode == "default") {
					XRServer::set_xr_mode(XRServer::XRMODE_DEFAULT);
				} else if (xr_mode == "off") {
					XRServer::set_xr_mode(XRServer::XRMODE_OFF);
				} else if (xr_mode == "on") {
					XRServer::set_xr_mode(XRServer::XRMODE_ON);
				} else {
					OS::get_singleton()->print("Unknown --xr-mode argument \"%s\", aborting.\n", xr_mode.ascii().get_data());
					goto error;
				}
			} else {
				OS::get_singleton()->print("Missing --xr-mode argument, aborting.\n");
				goto error;
			}

		} else if (I->get() == "--startup-benchmark") {
			use_startup_benchmark = true;
		} else if (I->get() == "--startup-benchmark-file") {
			if (I->next()) {
				use_startup_benchmark = true;
				startup_benchmark_file = I->next()->get();
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing <path> argument for --startup-benchmark-file <path>.\n");
				goto error;
			}

		} else if (I->get() == "--" || I->get() == "++") {
			adding_user_args = true;
		} else {
			main_args.push_back(I->get());
		}

		I = N;
	}

#ifdef TOOLS_ENABLED
	if (editor && project_manager) {
		OS::get_singleton()->print(
				"Error: Command line arguments implied opening both editor and project manager, which is not possible. Aborting.\n");
		goto error;
	}
#endif

	// Network file system needs to be configured before globals, since globals are based on the
	// 'project.godot' file which will only be available through the network if this is enabled
	FileAccessNetwork::configure();
	if (!remotefs.is_empty()) {
		file_access_network_client = memnew(FileAccessNetworkClient);
		int port;
		if (remotefs.contains(":")) {
			port = remotefs.get_slicec(':', 1).to_int();
			remotefs = remotefs.get_slicec(':', 0);
		} else {
			port = 6010;
		}

		Error err = file_access_network_client->connect(remotefs, port, remotefs_pass);
		if (err) {
			OS::get_singleton()->printerr("Could not connect to remotefs: %s:%i.\n", remotefs.utf8().get_data(), port);
			goto error;
		}

		FileAccess::make_default<FileAccessNetwork>(FileAccess::ACCESS_RESOURCES);
	}

	if (globals->setup(project_path, main_pack, upwards, editor) == OK) {
#ifdef TOOLS_ENABLED
		found_project = true;
#endif
	} else {
#ifdef TOOLS_ENABLED
		editor = false;
#else
		const String error_msg = "Error: Couldn't load project data at path \"" + project_path + "\". Is the .pck file missing?\nIf you've renamed the executable, the associated .pck file should also be renamed to match the executable's name (without the extension).\n";
		OS::get_singleton()->print("%s", error_msg.utf8().get_data());
		OS::get_singleton()->alert(error_msg);

		goto error;
#endif
	}

	// Initialize user data dir.
	OS::get_singleton()->ensure_user_data_dir();

	initialize_modules(MODULE_INITIALIZATION_LEVEL_CORE);
	register_core_extensions(); // core extensions must be registered after globals setup and before display

	ResourceUID::get_singleton()->load_from_cache(); // load UUIDs from cache.

	ProjectSettings::get_singleton()->set_custom_property_info("memory/limits/multithreaded_server/rid_pool_prealloc",
			PropertyInfo(Variant::INT,
					"memory/limits/multithreaded_server/rid_pool_prealloc",
					PROPERTY_HINT_RANGE,
					"0,500,1")); // No negative and limit to 500 due to crashes
	GLOBAL_DEF("network/limits/debugger/max_chars_per_second", 32768);
	ProjectSettings::get_singleton()->set_custom_property_info("network/limits/debugger/max_chars_per_second",
			PropertyInfo(Variant::INT,
					"network/limits/debugger/max_chars_per_second",
					PROPERTY_HINT_RANGE,
					"0, 4096, 1, or_greater"));
	GLOBAL_DEF("network/limits/debugger/max_queued_messages", 2048);
	ProjectSettings::get_singleton()->set_custom_property_info("network/limits/debugger/max_queued_messages",
			PropertyInfo(Variant::INT,
					"network/limits/debugger/max_queued_messages",
					PROPERTY_HINT_RANGE,
					"0, 8192, 1, or_greater"));
	GLOBAL_DEF("network/limits/debugger/max_errors_per_second", 400);
	ProjectSettings::get_singleton()->set_custom_property_info("network/limits/debugger/max_errors_per_second",
			PropertyInfo(Variant::INT,
					"network/limits/debugger/max_errors_per_second",
					PROPERTY_HINT_RANGE,
					"0, 200, 1, or_greater"));
	GLOBAL_DEF("network/limits/debugger/max_warnings_per_second", 400);
	ProjectSettings::get_singleton()->set_custom_property_info("network/limits/debugger/max_warnings_per_second",
			PropertyInfo(Variant::INT,
					"network/limits/debugger/max_warnings_per_second",
					PROPERTY_HINT_RANGE,
					"0, 200, 1, or_greater"));

	EngineDebugger::initialize(debug_uri, skip_breakpoints, breakpoints, []() {
		if (editor_pid) {
			DisplayServer::get_singleton()->enable_for_stealing_focus(editor_pid);
		}
	});

#ifdef TOOLS_ENABLED
	if (editor) {
		packed_data->set_disabled(true);
		globals->set_disable_feature_overrides(true);
		Engine::get_singleton()->set_editor_hint(true);
		main_args.push_back("--editor");
		if (!init_windowed) {
			init_maximized = true;
			window_mode = DisplayServer::WINDOW_MODE_MAXIMIZED;
		}
	}

	if (!project_manager && !editor) {
		// If we didn't find a project, we fall back to the project manager.
		project_manager = !found_project && !cmdline_tool;
	}

	if (project_manager) {
		Engine::get_singleton()->set_project_manager_hint(true);
	}
#endif

	GLOBAL_DEF("debug/file_logging/enable_file_logging", false);
	// Only file logging by default on desktop platforms as logs can't be
	// accessed easily on mobile/Web platforms (if at all).
	// This also prevents logs from being created for the editor instance, as feature tags
	// are disabled while in the editor (even if they should logically apply).
	GLOBAL_DEF("debug/file_logging/enable_file_logging.pc", true);
	GLOBAL_DEF("debug/file_logging/log_path", "user://logs/godot.log");
	GLOBAL_DEF("debug/file_logging/max_log_files", 5);
	ProjectSettings::get_singleton()->set_custom_property_info("debug/file_logging/max_log_files",
			PropertyInfo(Variant::INT,
					"debug/file_logging/max_log_files",
					PROPERTY_HINT_RANGE,
					"0,20,1,or_greater")); //no negative numbers
	if (!project_manager && !editor && FileAccess::get_create_func(FileAccess::ACCESS_USERDATA) &&
			GLOBAL_GET("debug/file_logging/enable_file_logging")) {
		// Don't create logs for the project manager as they would be written to
		// the current working directory, which is inconvenient.
		String base_path = GLOBAL_GET("debug/file_logging/log_path");
		int max_files = GLOBAL_GET("debug/file_logging/max_log_files");
		OS::get_singleton()->add_logger(memnew(RotatedFileLogger(base_path, max_files)));
	}

	if (main_args.size() == 0 && String(GLOBAL_GET("application/run/main_scene")) == "") {
#ifdef TOOLS_ENABLED
		if (!editor && !project_manager) {
#endif
			const String error_msg = "Error: Can't run project: no main scene defined in the project.\n";
			OS::get_singleton()->print("%s", error_msg.utf8().get_data());
			OS::get_singleton()->alert(error_msg);
			goto error;
#ifdef TOOLS_ENABLED
		}
#endif
	}

	if (editor || project_manager) {
		Engine::get_singleton()->set_editor_hint(true);
		use_custom_res = false;
		input_map->load_default(); //keys for editor
	} else {
		input_map->load_from_project_settings(); //keys for game
	}

	if (bool(GLOBAL_GET("application/run/disable_stdout"))) {
		quiet_stdout = true;
	}
	if (bool(GLOBAL_GET("application/run/disable_stderr"))) {
		CoreGlobals::print_error_enabled = false;
	};

	if (quiet_stdout) {
		CoreGlobals::print_line_enabled = false;
	}

	Logger::set_flush_stdout_on_print(GLOBAL_GET("application/run/flush_stdout_on_print"));

	OS::get_singleton()->set_cmdline(execpath, main_args, user_args);

	{
		String driver_hints = "";
#ifdef VULKAN_ENABLED
		driver_hints = "vulkan";
#endif

		String default_driver = driver_hints.get_slice(",", 0);

		// For now everything defaults to vulkan when available. This can change in future updates.
		GLOBAL_DEF("rendering/rendering_device/driver", default_driver);
		GLOBAL_DEF("rendering/rendering_device/driver.windows", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/rendering_device/driver.windows",
				PropertyInfo(Variant::STRING, "rendering/rendering_device/driver.windows", PROPERTY_HINT_ENUM, driver_hints));
		GLOBAL_DEF("rendering/rendering_device/driver.linuxbsd", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/rendering_device/driver.linuxbsd",
				PropertyInfo(Variant::STRING, "rendering/rendering_device/driver.linuxbsd", PROPERTY_HINT_ENUM, driver_hints));
		GLOBAL_DEF("rendering/rendering_device/driver.android", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/rendering_device/driver.android",
				PropertyInfo(Variant::STRING, "rendering/rendering_device/driver.android", PROPERTY_HINT_ENUM, driver_hints));
		GLOBAL_DEF("rendering/rendering_device/driver.ios", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/rendering_device/driver.ios",
				PropertyInfo(Variant::STRING, "rendering/rendering_device/driver.ios", PROPERTY_HINT_ENUM, driver_hints));
		GLOBAL_DEF("rendering/rendering_device/driver.macos", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/rendering_device/driver.macos",
				PropertyInfo(Variant::STRING, "rendering/rendering_device/driver.macos", PROPERTY_HINT_ENUM, driver_hints));

		driver_hints = "";
#ifdef GLES3_ENABLED
		driver_hints += "opengl3";
#endif

		default_driver = driver_hints.get_slice(",", 0);

		GLOBAL_DEF("rendering/gl_compatibility/driver", default_driver);
		GLOBAL_DEF("rendering/gl_compatibility/driver.windows", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/gl_compatibility/driver.windows",
				PropertyInfo(Variant::STRING, "rendering/gl_compatibility/driver.windows", PROPERTY_HINT_ENUM, driver_hints));
		GLOBAL_DEF("rendering/gl_compatibility/driver.linuxbsd", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/gl_compatibility/driver.linuxbsd",
				PropertyInfo(Variant::STRING, "rendering/gl_compatibility/driver.linuxbsd", PROPERTY_HINT_ENUM, driver_hints));
		GLOBAL_DEF("rendering/gl_compatibility/driver.web", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/gl_compatibility/driver.web",
				PropertyInfo(Variant::STRING, "rendering/gl_compatibility/driver.web", PROPERTY_HINT_ENUM, driver_hints));
		GLOBAL_DEF("rendering/gl_compatibility/driver.android", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/gl_compatibility/driver.android",
				PropertyInfo(Variant::STRING, "rendering/gl_compatibility/driver.android", PROPERTY_HINT_ENUM, driver_hints));
		GLOBAL_DEF("rendering/gl_compatibility/driver.ios", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/gl_compatibility/driver.ios",
				PropertyInfo(Variant::STRING, "rendering/gl_compatibility/driver.ios", PROPERTY_HINT_ENUM, driver_hints));
		GLOBAL_DEF("rendering/gl_compatibility/driver.macos", default_driver);
		ProjectSettings::get_singleton()->set_custom_property_info("rendering/gl_compatibility/driver.macos",
				PropertyInfo(Variant::STRING, "rendering/gl_compatibility/driver.macos", PROPERTY_HINT_ENUM, driver_hints));
	}

	// Start with RenderingDevice-based backends. Should be included if any RD driver present.
#ifdef VULKAN_ENABLED
	renderer_hints = "forward_plus,mobile";
	default_renderer_mobile = "mobile";
#endif

	// And Compatibility next, or first if Vulkan is disabled.
#ifdef GLES3_ENABLED
	if (!renderer_hints.is_empty()) {
		renderer_hints += ",";
	}
	renderer_hints += "gl_compatibility";
	if (default_renderer_mobile.is_empty()) {
		default_renderer_mobile = "gl_compatibility";
	}
	// Default to Compatibility when using the project manager.
	if (rendering_driver.is_empty() && rendering_method.is_empty() && project_manager) {
		rendering_driver = "opengl3";
		rendering_method = "gl_compatibility";
		default_renderer_mobile = "gl_compatibility";
	}
#endif
	if (renderer_hints.is_empty()) {
		ERR_PRINT("No renderers available.");
	}

	if (!rendering_method.is_empty()) {
		if (rendering_method != "forward_plus" &&
				rendering_method != "mobile" &&
				rendering_method != "gl_compatibility") {
			OS::get_singleton()->print("Unknown renderer name '%s', aborting. Valid options are: %s\n", rendering_method.utf8().get_data(), renderer_hints.utf8().get_data());
			goto error;
		}
	}

	if (!rendering_driver.is_empty()) {
		// As the rendering drivers available may depend on the display driver and renderer
		// selected, we can't do an exhaustive check here, but we can look through all
		// the options in all the display drivers for a match.

		bool found = false;
		for (int i = 0; i < DisplayServer::get_create_function_count(); i++) {
			Vector<String> r_drivers = DisplayServer::get_create_function_rendering_drivers(i);

			for (int d = 0; d < r_drivers.size(); d++) {
				if (rendering_driver == r_drivers[d]) {
					found = true;
					break;
				}
			}
		}

		if (!found) {
			OS::get_singleton()->print("Unknown rendering driver '%s', aborting.\nValid options are ",
					rendering_driver.utf8().get_data());

			for (int i = 0; i < DisplayServer::get_create_function_count(); i++) {
				Vector<String> r_drivers = DisplayServer::get_create_function_rendering_drivers(i);

				for (int d = 0; d < r_drivers.size(); d++) {
					OS::get_singleton()->print("'%s', ", r_drivers[d].utf8().get_data());
				}
			}

			OS::get_singleton()->print(".\n");

			goto error;
		}

		// Set a default renderer if none selected. Try to choose one that matches the driver.
		if (rendering_method.is_empty()) {
			if (rendering_driver == "opengl3") {
				rendering_method = "gl_compatibility";
			} else {
				rendering_method = "forward_plus";
			}
		}

		// Now validate whether the selected driver matches with the renderer.
		bool valid_combination = false;
		Vector<String> available_drivers;
#ifdef VULKAN_ENABLED
		if (rendering_method == "forward_plus" || rendering_method == "mobile") {
			available_drivers.push_back("vulkan");
		}
#endif
#ifdef GLES3_ENABLED
		if (rendering_method == "gl_compatibility") {
			available_drivers.push_back("opengl3");
		}
#endif
		if (available_drivers.is_empty()) {
			OS::get_singleton()->print("Unknown renderer name '%s', aborting.\n", rendering_method.utf8().get_data());
			goto error;
		}

		for (int i = 0; i < available_drivers.size(); i++) {
			if (rendering_driver == available_drivers[i]) {
				valid_combination = true;
				break;
			}
		}

		if (!valid_combination) {
			OS::get_singleton()->print("Invalid renderer/driver combination '%s' and '%s', aborting. %s only supports the following drivers ", rendering_method.utf8().get_data(), rendering_driver.utf8().get_data(), rendering_method.utf8().get_data());

			for (int d = 0; d < available_drivers.size(); d++) {
				OS::get_singleton()->print("'%s', ", available_drivers[d].utf8().get_data());
			}

			OS::get_singleton()->print(".\n");

			goto error;
		}
	}

	default_renderer = renderer_hints.get_slice(",", 0);
	GLOBAL_DEF_RST_BASIC("rendering/renderer/rendering_method", default_renderer);
	GLOBAL_DEF_RST_BASIC("rendering/renderer/rendering_method.mobile", default_renderer_mobile);
	GLOBAL_DEF_RST_BASIC("rendering/renderer/rendering_method.web", "gl_compatibility"); // This is a bit of a hack until we have WebGPU support.

	ProjectSettings::get_singleton()->set_custom_property_info("rendering/renderer/rendering_method",
			PropertyInfo(Variant::STRING,
					"rendering/renderer/rendering_method",
					PROPERTY_HINT_ENUM, renderer_hints));

	// Default to ProjectSettings default if nothing set on the command line.
	if (rendering_method.is_empty()) {
		rendering_method = GLOBAL_GET("rendering/renderer/rendering_method");
	}

	if (rendering_driver.is_empty()) {
		if (rendering_method == "gl_compatibility") {
			rendering_driver = GLOBAL_GET("rendering/gl_compatibility/driver");
		} else {
			rendering_driver = GLOBAL_GET("rendering/rendering_device/driver");
		}
	}

	// note this is the desired rendering driver, it doesn't mean we will get it.
	// TODO - make sure this is updated in the case of fallbacks, so that the user interface
	// shows the correct driver string.
	OS::get_singleton()->set_current_rendering_driver_name(rendering_driver);
	OS::get_singleton()->set_current_rendering_method(rendering_method);

	// always convert to lower case for consistency in the code
	rendering_driver = rendering_driver.to_lower();

	if (use_custom_res) {
		if (!force_res) {
			window_size.width = GLOBAL_GET("display/window/size/viewport_width");
			window_size.height = GLOBAL_GET("display/window/size/viewport_height");

			if (globals->has_setting("display/window/size/window_width_override") &&
					globals->has_setting("display/window/size/window_height_override")) {
				int desired_width = globals->get("display/window/size/window_width_override");
				if (desired_width > 0) {
					window_size.width = desired_width;
				}
				int desired_height = globals->get("display/window/size/window_height_override");
				if (desired_height > 0) {
					window_size.height = desired_height;
				}
			}
		}

		if (!bool(GLOBAL_GET("display/window/size/resizable"))) {
			window_flags |= DisplayServer::WINDOW_FLAG_RESIZE_DISABLED_BIT;
		}
		if (bool(GLOBAL_GET("display/window/size/borderless"))) {
			window_flags |= DisplayServer::WINDOW_FLAG_BORDERLESS_BIT;
		}
		if (bool(GLOBAL_GET("display/window/size/always_on_top"))) {
			window_flags |= DisplayServer::WINDOW_FLAG_ALWAYS_ON_TOP_BIT;
		}
		if (bool(GLOBAL_GET("display/window/size/transparent"))) {
			window_flags |= DisplayServer::WINDOW_FLAG_TRANSPARENT_BIT;
		}
		if (bool(GLOBAL_GET("display/window/size/extend_to_title"))) {
			window_flags |= DisplayServer::WINDOW_FLAG_EXTEND_TO_TITLE_BIT;
		}
		if (bool(GLOBAL_GET("display/window/size/no_focus"))) {
			window_flags |= DisplayServer::WINDOW_FLAG_NO_FOCUS_BIT;
		}
		window_mode = (DisplayServer::WindowMode)(GLOBAL_GET("display/window/size/mode").operator int());
	}

	GLOBAL_DEF("internationalization/locale/include_text_server_data", false);

	OS::get_singleton()->_allow_hidpi = GLOBAL_DEF("display/window/dpi/allow_hidpi", true);
	OS::get_singleton()->_allow_layered = GLOBAL_DEF("display/window/per_pixel_transparency/allowed", false);

	if (editor || project_manager) {
		// The editor and project manager always detect and use hiDPI if needed
		OS::get_singleton()->_allow_hidpi = true;
	}

	if (rtm == -1) {
		rtm = GLOBAL_DEF("rendering/driver/threads/thread_model", OS::RENDER_THREAD_SAFE);
	}

	if (rtm >= 0 && rtm < 3) {
		if (editor) {
			rtm = OS::RENDER_THREAD_SAFE;
		}
		OS::get_singleton()->_render_thread_mode = OS::RenderThreadMode(rtm);
	}

	/* Determine audio and video drivers */

	// Display driver, e.g. X11, Wayland.
	// Make sure that headless is the last one, which it is assumed to be by design.
	DEV_ASSERT(String("headless") == DisplayServer::get_create_function_name(DisplayServer::get_create_function_count() - 1));
	for (int i = 0; i < DisplayServer::get_create_function_count(); i++) {
		String name = DisplayServer::get_create_function_name(i);
		if (display_driver == name) {
			display_driver_idx = i;
			break;
		}
	}

	if (display_driver_idx < 0) {
		// If the requested driver wasn't found, pick the first entry.
		// If all else failed it would be the headless server.
		display_driver_idx = 0;
	}

	// Store this in a globally accessible place, so we can retrieve the rendering drivers
	// list from the display driver for the editor UI.
	OS::get_singleton()->set_display_driver_id(display_driver_idx);

	GLOBAL_DEF_RST_NOVAL("audio/driver/driver", AudioDriverManager::get_driver(0)->get_name());
	if (audio_driver.is_empty()) { // Specified in project.godot.
		audio_driver = GLOBAL_GET("audio/driver/driver");
	}

	// Make sure that dummy is the last one, which it is assumed to be by design.
	DEV_ASSERT(String("Dummy") == AudioDriverManager::get_driver(AudioDriverManager::get_driver_count() - 1)->get_name());
	for (int i = 0; i < AudioDriverManager::get_driver_count(); i++) {
		if (audio_driver == AudioDriverManager::get_driver(i)->get_name()) {
			audio_driver_idx = i;
			break;
		}
	}

	if (audio_driver_idx < 0) {
		// If the requested driver wasn't found, pick the first entry.
		// If all else failed it would be the dummy driver (no sound).
		audio_driver_idx = 0;
	}

	if (Engine::get_singleton()->get_write_movie_path() != String()) {
		// Always use dummy driver for audio driver (which is last), also in no threaded mode.
		audio_driver_idx = AudioDriverManager::get_driver_count() - 1;
		AudioDriverDummy::get_dummy_singleton()->set_use_threads(false);
	}

	{
		window_orientation = DisplayServer::ScreenOrientation(int(GLOBAL_DEF_BASIC("display/window/handheld/orientation", DisplayServer::ScreenOrientation::SCREEN_LANDSCAPE)));
	}
	{
		window_vsync_mode = DisplayServer::VSyncMode(int(GLOBAL_DEF("display/window/vsync/vsync_mode", DisplayServer::VSyncMode::VSYNC_ENABLED)));
		if (disable_vsync) {
			window_vsync_mode = DisplayServer::VSyncMode::VSYNC_DISABLED;
		}
	}
	Engine::get_singleton()->set_physics_ticks_per_second(GLOBAL_DEF_BASIC("physics/common/physics_ticks_per_second", 60));
	ProjectSettings::get_singleton()->set_custom_property_info("physics/common/physics_ticks_per_second",
			PropertyInfo(Variant::INT, "physics/common/physics_ticks_per_second",
					PROPERTY_HINT_RANGE, "1,1000,1"));

	Engine::get_singleton()->set_max_physics_steps_per_frame(GLOBAL_DEF("physics/common/max_physics_steps_per_frame", 8));
	ProjectSettings::get_singleton()->set_custom_property_info("physics/common/max_physics_steps_per_frame",
			PropertyInfo(Variant::INT, "physics/common/max_physics_steps_per_frame",
					PROPERTY_HINT_RANGE, "1,100,1"));

	Engine::get_singleton()->set_physics_jitter_fix(GLOBAL_DEF("physics/common/physics_jitter_fix", 0.5));
	Engine::get_singleton()->set_max_fps(GLOBAL_DEF("application/run/max_fps", 0));
	ProjectSettings::get_singleton()->set_custom_property_info("application/run/max_fps",
			PropertyInfo(Variant::INT,
					"application/run/max_fps",
					PROPERTY_HINT_RANGE, "0,1000,1"));

	GLOBAL_DEF("debug/settings/stdout/print_fps", false);
	GLOBAL_DEF("debug/settings/stdout/print_gpu_profile", false);
	GLOBAL_DEF("debug/settings/stdout/verbose_stdout", false);

	if (!OS::get_singleton()->_verbose_stdout) { // Not manually overridden.
		OS::get_singleton()->_verbose_stdout = GLOBAL_GET("debug/settings/stdout/verbose_stdout");
	}

	if (frame_delay == 0) {
		frame_delay = GLOBAL_DEF("application/run/frame_delay_msec", 0);
		ProjectSettings::get_singleton()->set_custom_property_info("application/run/frame_delay_msec",
				PropertyInfo(Variant::INT,
						"application/run/frame_delay_msec",
						PROPERTY_HINT_RANGE,
						"0,100,1,or_greater")); // No negative numbers
	}

	OS::get_singleton()->set_low_processor_usage_mode(GLOBAL_DEF("application/run/low_processor_mode", false));
	OS::get_singleton()->set_low_processor_usage_mode_sleep_usec(
			GLOBAL_DEF("application/run/low_processor_mode_sleep_usec", 6900)); // Roughly 144 FPS
	ProjectSettings::get_singleton()->set_custom_property_info("application/run/low_processor_mode_sleep_usec",
			PropertyInfo(Variant::INT,
					"application/run/low_processor_mode_sleep_usec",
					PROPERTY_HINT_RANGE,
					"0,33200,1,or_greater")); // No negative numbers

	GLOBAL_DEF("display/window/ios/allow_high_refresh_rate", true);
	GLOBAL_DEF("display/window/ios/hide_home_indicator", true);
	GLOBAL_DEF("display/window/ios/hide_status_bar", true);
	GLOBAL_DEF("display/window/ios/suppress_ui_gesture", true);
	GLOBAL_DEF("input_devices/pointing/ios/touch_delay", 0.15);
	ProjectSettings::get_singleton()->set_custom_property_info("input_devices/pointing/ios/touch_delay",
			PropertyInfo(Variant::FLOAT,
					"input_devices/pointing/ios/touch_delay",
					PROPERTY_HINT_RANGE, "0,1,0.001"));

	// XR project settings.
	GLOBAL_DEF_RST_BASIC("xr/openxr/enabled", false);
	GLOBAL_DEF_BASIC("xr/openxr/default_action_map", "res://openxr_action_map.tres");
	ProjectSettings::get_singleton()->set_custom_property_info("xr/openxr/default_action_map", PropertyInfo(Variant::STRING, "xr/openxr/default_action_map", PROPERTY_HINT_FILE, "*.tres"));

	GLOBAL_DEF_BASIC("xr/openxr/form_factor", "0");
	ProjectSettings::get_singleton()->set_custom_property_info("xr/openxr/form_factor", PropertyInfo(Variant::INT, "xr/openxr/form_factor", PROPERTY_HINT_ENUM, "Head Mounted,Handheld"));

	GLOBAL_DEF_BASIC("xr/openxr/view_configuration", "1");
	ProjectSettings::get_singleton()->set_custom_property_info("xr/openxr/view_configuration", PropertyInfo(Variant::INT, "xr/openxr/view_configuration", PROPERTY_HINT_ENUM, "Mono,Stereo")); // "Mono,Stereo,Quad,Observer"

	GLOBAL_DEF_BASIC("xr/openxr/reference_space", "1");
	ProjectSettings::get_singleton()->set_custom_property_info("xr/openxr/reference_space", PropertyInfo(Variant::INT, "xr/openxr/reference_space", PROPERTY_HINT_ENUM, "Local,Stage"));

#ifdef TOOLS_ENABLED
	// Disabled for now, using XR inside of the editor we'll be working on during the coming months.

	// editor settings (it seems we're too early in the process when setting up rendering, to access editor settings...)
	// EDITOR_DEF_RST("xr/openxr/in_editor", false);
	// GLOBAL_DEF("xr/openxr/in_editor", false);
#endif

	Engine::get_singleton()->set_frame_delay(frame_delay);

	message_queue = memnew(MessageQueue);

	engine->startup_benchmark_end_measure(); // core

	if (p_second_phase) {
		return setup2();
	}

	return OK;

error:

	text_driver = "";
	display_driver = "";
	audio_driver = "";
	tablet_driver = "";
	Engine::get_singleton()->set_write_movie_path(String());
	project_path = "";

	args.clear();
	main_args.clear();

	if (show_help) {
		print_help(execpath);
	}

	EngineDebugger::deinitialize();

	if (performance) {
		memdelete(performance);
	}
	if (input_map) {
		memdelete(input_map);
	}
	if (time_singleton) {
		memdelete(time_singleton);
	}
	if (translation_server) {
		memdelete(translation_server);
	}
	if (globals) {
		memdelete(globals);
	}
	if (engine) {
		memdelete(engine);
	}
	if (packed_data) {
		memdelete(packed_data);
	}
	if (file_access_network_client) {
		memdelete(file_access_network_client);
	}

	unregister_core_driver_types();
	unregister_core_extensions();
	unregister_core_types();

	OS::get_singleton()->_cmdline.clear();
	OS::get_singleton()->_user_args.clear();

	if (message_queue) {
		memdelete(message_queue);
	}
	OS::get_singleton()->finalize_core();
	locale = String();

	return exit_code;
}

Error Main::setup2(Thread::ID p_main_tid_override) {
	// Print engine name and version
	print_line(String(VERSION_NAME) + " v" + get_full_version_string() + " - " + String(VERSION_WEBSITE));

	engine->startup_benchmark_begin_measure("servers");

	tsman = memnew(TextServerManager);

	if (tsman) {
		Ref<TextServerDummy> ts;
		ts.instantiate();
		tsman->add_interface(ts);
	}

	physics_server_3d_manager = memnew(PhysicsServer3DManager);
	physics_server_2d_manager = memnew(PhysicsServer2DManager);

	register_server_types();
	initialize_modules(MODULE_INITIALIZATION_LEVEL_SERVERS);
	NativeExtensionManager::get_singleton()->initialize_extensions(NativeExtension::INITIALIZATION_LEVEL_SERVERS);

	if (p_main_tid_override) {
		Thread::main_thread_id = p_main_tid_override;
	}

#ifdef TOOLS_ENABLED
	if (editor || project_manager || cmdline_tool) {
		EditorPaths::create();
		if (found_project && EditorPaths::get_singleton()->is_self_contained()) {
			if (ProjectSettings::get_singleton()->get_resource_path() == OS::get_singleton()->get_executable_path().get_base_dir()) {
				ERR_PRINT("You are trying to run a self-contained editor at the same location as a project. This is not allowed, since editor files will mix with project files.");
				OS::get_singleton()->set_exit_code(EXIT_FAILURE);
				return FAILED;
			}
		}
	}
#endif

	/* Initialize Input */

	input = memnew(Input);

	/* Initialize Display Server */

	{
		String display_driver = DisplayServer::get_create_function_name(display_driver_idx);

		Vector2i *window_position = nullptr;
		Vector2i position = init_custom_pos;
		if (init_use_custom_pos) {
			window_position = &position;
		}

		// rendering_driver now held in static global String in main and initialized in setup()
		Error err;
		display_server = DisplayServer::create(display_driver_idx, rendering_driver, window_mode, window_vsync_mode, window_flags, window_position, window_size, err);
		if (err != OK || display_server == nullptr) {
			// We can't use this display server, try other ones as fallback.
			// Skip headless (always last registered) because that's not what users
			// would expect if they didn't request it explicitly.
			for (int i = 0; i < DisplayServer::get_create_function_count() - 1; i++) {
				if (i == display_driver_idx) {
					continue; // Don't try the same twice.
				}
				display_server = DisplayServer::create(i, rendering_driver, window_mode, window_vsync_mode, window_flags, window_position, window_size, err);
				if (err == OK && display_server != nullptr) {
					break;
				}
			}
		}

		if (err != OK || display_server == nullptr) {
			ERR_PRINT("Unable to create DisplayServer, all display drivers failed.");
			return err;
		}
	}

	if (display_server->has_feature(DisplayServer::FEATURE_ORIENTATION)) {
		display_server->screen_set_orientation(window_orientation);
	}

	if (GLOBAL_GET("debug/settings/stdout/print_fps") || print_fps) {
		// Print requested V-Sync mode at startup to diagnose the printed FPS not going above the monitor refresh rate.
		switch (window_vsync_mode) {
			case DisplayServer::VSyncMode::VSYNC_DISABLED:
				print_line("Requested V-Sync mode: Disabled");
				break;
			case DisplayServer::VSyncMode::VSYNC_ENABLED:
				print_line("Requested V-Sync mode: Enabled - FPS will likely be capped to the monitor refresh rate.");
				break;
			case DisplayServer::VSyncMode::VSYNC_ADAPTIVE:
				print_line("Requested V-Sync mode: Adaptive");
				break;
			case DisplayServer::VSyncMode::VSYNC_MAILBOX:
				print_line("Requested V-Sync mode: Mailbox");
				break;
		}
	}

	/* Initialize Pen Tablet Driver */

	{
		GLOBAL_DEF_RST_NOVAL("input_devices/pen_tablet/driver", "");
		GLOBAL_DEF_RST_NOVAL("input_devices/pen_tablet/driver.windows", "");
		ProjectSettings::get_singleton()->set_custom_property_info("input_devices/pen_tablet/driver.windows", PropertyInfo(Variant::STRING, "input_devices/pen_tablet/driver.windows", PROPERTY_HINT_ENUM, "wintab,winink"));
	}

	if (tablet_driver.is_empty()) { // specified in project.godot
		tablet_driver = GLOBAL_GET("input_devices/pen_tablet/driver");
		if (tablet_driver.is_empty()) {
			tablet_driver = DisplayServer::get_singleton()->tablet_get_driver_name(0);
		}
	}

	for (int i = 0; i < DisplayServer::get_singleton()->tablet_get_driver_count(); i++) {
		if (tablet_driver == DisplayServer::get_singleton()->tablet_get_driver_name(i)) {
			DisplayServer::get_singleton()->tablet_set_current_driver(DisplayServer::get_singleton()->tablet_get_driver_name(i));
			break;
		}
	}

	if (DisplayServer::get_singleton()->tablet_get_current_driver().is_empty()) {
		DisplayServer::get_singleton()->tablet_set_current_driver(DisplayServer::get_singleton()->tablet_get_driver_name(0));
	}

	print_verbose("Using \"" + tablet_driver + "\" pen tablet driver...");

	/* Initialize Rendering Server */

	rendering_server = memnew(RenderingServerDefault(OS::get_singleton()->get_render_thread_mode() == OS::RENDER_SEPARATE_THREAD));

	rendering_server->init();
	//rendering_server->call_set_use_vsync(OS::get_singleton()->_use_vsync);
	rendering_server->set_render_loop_enabled(!disable_render_loop);

	if (profile_gpu || (!editor && bool(GLOBAL_GET("debug/settings/stdout/print_gpu_profile")))) {
		rendering_server->set_print_gpu_profile(true);
	}

	if (Engine::get_singleton()->get_write_movie_path() != String()) {
		movie_writer = MovieWriter::find_writer_for_file(Engine::get_singleton()->get_write_movie_path());
		if (movie_writer == nullptr) {
			ERR_PRINT("Can't find movie writer for file type, aborting: " + Engine::get_singleton()->get_write_movie_path());
			Engine::get_singleton()->set_write_movie_path(String());
		}
	}

#ifdef UNIX_ENABLED
	// Print warning after initializing the renderer but before initializing audio.
	if (OS::get_singleton()->get_environment("USER") == "root" && !OS::get_singleton()->has_environment("GODOT_SILENCE_ROOT_WARNING")) {
		WARN_PRINT("Started the engine as `root`/superuser. This is a security risk, and subsystems like audio may not work correctly.\nSet the environment variable `GODOT_SILENCE_ROOT_WARNING` to 1 to silence this warning.");
	}
#endif

	OS::get_singleton()->initialize_joypads();

	/* Initialize Audio Driver */

	AudioDriverManager::initialize(audio_driver_idx);

	print_line(" "); //add a blank line for readability

	if (init_use_custom_pos) {
		display_server->window_set_position(init_custom_pos);
	}

	// right moment to create and initialize the audio server

	audio_server = memnew(AudioServer);
	audio_server->init();

	// also init our xr_server from here
	xr_server = memnew(XRServer);

	register_core_singletons();

	MAIN_PRINT("Main: Setup Logo");

#if defined(WEB_ENABLED) || defined(ANDROID_ENABLED)
	bool show_logo = false;
#else
	bool show_logo = true;
#endif

	if (init_screen != -1) {
		DisplayServer::get_singleton()->window_set_current_screen(init_screen);
	}
	if (init_windowed) {
		//do none..
	} else if (init_maximized) {
		DisplayServer::get_singleton()->window_set_mode(DisplayServer::WINDOW_MODE_MAXIMIZED);
	} else if (init_fullscreen) {
		DisplayServer::get_singleton()->window_set_mode(DisplayServer::WINDOW_MODE_FULLSCREEN);
	}
	if (init_always_on_top) {
		DisplayServer::get_singleton()->window_set_flag(DisplayServer::WINDOW_FLAG_ALWAYS_ON_TOP, true);
	}

	MAIN_PRINT("Main: Load Boot Image");

	Color clear = GLOBAL_DEF_BASIC("rendering/environment/defaults/default_clear_color", Color(0.3, 0.3, 0.3));
	RenderingServer::get_singleton()->set_default_clear_color(clear);

	if (show_logo) { //boot logo!
		const bool boot_logo_image = GLOBAL_DEF_BASIC("application/boot_splash/show_image", true);
		const String boot_logo_path = String(GLOBAL_DEF_BASIC("application/boot_splash/image", String())).strip_edges();
		const bool boot_logo_scale = GLOBAL_DEF_BASIC("application/boot_splash/fullsize", true);
		const bool boot_logo_filter = GLOBAL_DEF_BASIC("application/boot_splash/use_filter", true);
		ProjectSettings::get_singleton()->set_custom_property_info("application/boot_splash/image",
				PropertyInfo(Variant::STRING,
						"application/boot_splash/image",
						PROPERTY_HINT_FILE, "*.png"));

		Ref<Image> boot_logo;

		if (boot_logo_image) {
			if (!boot_logo_path.is_empty()) {
				boot_logo.instantiate();
				Error load_err = ImageLoader::load_image(boot_logo_path, boot_logo);
				if (load_err) {
					ERR_PRINT("Non-existing or invalid boot splash at '" + boot_logo_path + "'. Loading default splash.");
				}
			}
		} else {
			// Create a 1×1 transparent image. This will effectively hide the splash image.
			boot_logo.instantiate();
			boot_logo->initialize_data(1, 1, false, Image::FORMAT_RGBA8);
			boot_logo->set_pixel(0, 0, Color(0, 0, 0, 0));
		}

		Color boot_bg_color = GLOBAL_DEF_BASIC("application/boot_splash/bg_color", boot_splash_bg_color);

#if defined(TOOLS_ENABLED) && !defined(NO_EDITOR_SPLASH)
		boot_bg_color =
				GLOBAL_DEF_BASIC("application/boot_splash/bg_color",
						(editor || project_manager) ? boot_splash_editor_bg_color : boot_splash_bg_color);
#endif
		if (boot_logo.is_valid()) {
			RenderingServer::get_singleton()->set_boot_image(boot_logo, boot_bg_color, boot_logo_scale,
					boot_logo_filter);

		} else {
#ifndef NO_DEFAULT_BOOT_LOGO
			MAIN_PRINT("Main: Create bootsplash");
#if defined(TOOLS_ENABLED) && !defined(NO_EDITOR_SPLASH)
			Ref<Image> splash = (editor || project_manager) ? memnew(Image(boot_splash_editor_png)) : memnew(Image(boot_splash_png));
#else
			Ref<Image> splash = memnew(Image(boot_splash_png));
#endif

			MAIN_PRINT("Main: ClearColor");
			RenderingServer::get_singleton()->set_default_clear_color(boot_bg_color);
			MAIN_PRINT("Main: Image");
			RenderingServer::get_singleton()->set_boot_image(splash, boot_bg_color, false);
#endif
		}

#ifdef TOOLS_ENABLED
		if (OS::get_singleton()->get_bundle_icon_path().is_empty()) {
			Ref<Image> icon = memnew(Image(app_icon_png));
			DisplayServer::get_singleton()->set_icon(icon);
		}
#endif
	}

	MAIN_PRINT("Main: DCC");
	RenderingServer::get_singleton()->set_default_clear_color(
			GLOBAL_GET("rendering/environment/defaults/default_clear_color"));

	GLOBAL_DEF("application/config/icon", String());
	ProjectSettings::get_singleton()->set_custom_property_info("application/config/icon",
			PropertyInfo(Variant::STRING, "application/config/icon",
					PROPERTY_HINT_FILE, "*.png,*.webp,*.svg"));

	GLOBAL_DEF("application/config/macos_native_icon", String());
	ProjectSettings::get_singleton()->set_custom_property_info("application/config/macos_native_icon",
			PropertyInfo(Variant::STRING,
					"application/config/macos_native_icon",
					PROPERTY_HINT_FILE, "*.icns"));

	GLOBAL_DEF("application/config/windows_native_icon", String());
	ProjectSettings::get_singleton()->set_custom_property_info("application/config/windows_native_icon",
			PropertyInfo(Variant::STRING,
					"application/config/windows_native_icon",
					PROPERTY_HINT_FILE, "*.ico"));

	Input *id = Input::get_singleton();
	if (id) {
		agile_input_event_flushing = GLOBAL_DEF("input_devices/buffering/agile_event_flushing", false);

		if (bool(GLOBAL_DEF("input_devices/pointing/emulate_touch_from_mouse", false)) &&
				!(editor || project_manager)) {
			bool found_touchscreen = false;
			for (int i = 0; i < DisplayServer::get_singleton()->get_screen_count(); i++) {
				if (DisplayServer::get_singleton()->screen_is_touchscreen(i)) {
					found_touchscreen = true;
				}
			}
			if (!found_touchscreen) {
				//only if no touchscreen ui hint, set emulation
				id->set_emulate_touch_from_mouse(true);
			}
		}

		id->set_emulate_mouse_from_touch(bool(GLOBAL_DEF("input_devices/pointing/emulate_mouse_from_touch", true)));
	}

	MAIN_PRINT("Main: Load Translations and Remaps");

	translation_server->setup(); //register translations, load them, etc.
	if (!locale.is_empty()) {
		translation_server->set_locale(locale);
	}
	translation_server->load_translations();
	ResourceLoader::load_translation_remaps(); //load remaps for resources

	ResourceLoader::load_path_remaps();

	MAIN_PRINT("Main: Load TextServer");

	/* Enum text drivers */
	GLOBAL_DEF_RST("internationalization/rendering/text_driver", "");
	String text_driver_options;
	for (int i = 0; i < TextServerManager::get_singleton()->get_interface_count(); i++) {
		const String driver_name = TextServerManager::get_singleton()->get_interface(i)->get_name();
		if (driver_name == "Dummy") {
			// Dummy text driver cannot draw any text, making the editor unusable if selected.
			continue;
		}
		if (!text_driver_options.is_empty() && text_driver_options.find(",") == -1) {
			// Not the first option; add a comma before it as a separator for the property hint.
			text_driver_options += ",";
		}
		text_driver_options += driver_name;
	}
	ProjectSettings::get_singleton()->set_custom_property_info("internationalization/rendering/text_driver", PropertyInfo(Variant::STRING, "internationalization/rendering/text_driver", PROPERTY_HINT_ENUM, text_driver_options));

	/* Determine text driver */
	if (text_driver.is_empty()) {
		text_driver = GLOBAL_GET("internationalization/rendering/text_driver");
	}

	if (!text_driver.is_empty()) {
		/* Load user selected text server. */
		for (int i = 0; i < TextServerManager::get_singleton()->get_interface_count(); i++) {
			if (TextServerManager::get_singleton()->get_interface(i)->get_name() == text_driver) {
				text_driver_idx = i;
				break;
			}
		}
	}

	if (text_driver_idx < 0) {
		/* If not selected, use one with the most features available. */
		int max_features = 0;
		for (int i = 0; i < TextServerManager::get_singleton()->get_interface_count(); i++) {
			uint32_t features = TextServerManager::get_singleton()->get_interface(i)->get_features();
			int feature_number = 0;
			while (features) {
				feature_number += features & 1;
				features >>= 1;
			}
			if (feature_number >= max_features) {
				max_features = feature_number;
				text_driver_idx = i;
			}
		}
	}
	if (text_driver_idx >= 0) {
		TextServerManager::get_singleton()->set_primary_interface(TextServerManager::get_singleton()->get_interface(text_driver_idx));
	} else {
		ERR_FAIL_V_MSG(ERR_CANT_CREATE, "TextServer: Unable to create TextServer interface.");
	}

	engine->startup_benchmark_end_measure(); // servers

	MAIN_PRINT("Main: Load Scene Types");

	engine->startup_benchmark_begin_measure("scene");

	register_scene_types();
	register_driver_types();

	initialize_modules(MODULE_INITIALIZATION_LEVEL_SCENE);
	NativeExtensionManager::get_singleton()->initialize_extensions(NativeExtension::INITIALIZATION_LEVEL_SCENE);

#ifdef TOOLS_ENABLED
	ClassDB::set_current_api(ClassDB::API_EDITOR);
	register_editor_types();
	initialize_modules(MODULE_INITIALIZATION_LEVEL_EDITOR);
	NativeExtensionManager::get_singleton()->initialize_extensions(NativeExtension::INITIALIZATION_LEVEL_EDITOR);

	ClassDB::set_current_api(ClassDB::API_CORE);

#endif

	MAIN_PRINT("Main: Load Modules");

	register_platform_apis();

	// Theme needs modules to be initialized so that sub-resources can be loaded.
	initialize_theme_db();
	register_scene_singletons();

	GLOBAL_DEF_BASIC("display/mouse_cursor/custom_image", String());
	GLOBAL_DEF_BASIC("display/mouse_cursor/custom_image_hotspot", Vector2());
	GLOBAL_DEF_BASIC("display/mouse_cursor/tooltip_position_offset", Point2(10, 10));
	ProjectSettings::get_singleton()->set_custom_property_info("display/mouse_cursor/custom_image",
			PropertyInfo(Variant::STRING,
					"display/mouse_cursor/custom_image",
					PROPERTY_HINT_FILE, "*.png,*.webp"));

	if (String(GLOBAL_GET("display/mouse_cursor/custom_image")) != String()) {
		Ref<Texture2D> cursor = ResourceLoader::load(
				GLOBAL_GET("display/mouse_cursor/custom_image"));
		if (cursor.is_valid()) {
			Vector2 hotspot = GLOBAL_GET("display/mouse_cursor/custom_image_hotspot");
			Input::get_singleton()->set_custom_mouse_cursor(cursor, Input::CURSOR_ARROW, hotspot);
		}
	}

	camera_server = CameraServer::create();

	MAIN_PRINT("Main: Load Physics");

	initialize_physics();
	initialize_navigation_server();
	register_server_singletons();

	// This loads global classes, so it must happen before custom loaders and savers are registered
	ScriptServer::init_languages();

	audio_server->load_default_bus_layout();

	if (use_debug_profiler && EngineDebugger::is_active()) {
		// Start the "scripts" profiler, used in local debugging.
		// We could add more, and make the CLI arg require a comma-separated list of profilers.
		EngineDebugger::get_singleton()->profiler_enable("scripts", true);
	}

	if (!project_manager) {
		// If not running the project manager, and now that the engine is
		// able to load resources, load the global shader variables.
		// If running on editor, don't load the textures because the editor
		// may want to import them first. Editor will reload those later.
		rendering_server->global_shader_parameters_load_settings(!editor);
	}

	_start_success = true;

	ClassDB::set_current_api(ClassDB::API_NONE); //no more APIs are registered at this point

	print_verbose("CORE API HASH: " + uitos(ClassDB::get_api_hash(ClassDB::API_CORE)));
	print_verbose("EDITOR API HASH: " + uitos(ClassDB::get_api_hash(ClassDB::API_EDITOR)));
	MAIN_PRINT("Main: Done");

	engine->startup_benchmark_end_measure(); // scene

	return OK;
}

String Main::get_rendering_driver_name() {
	return rendering_driver;
}

// everything the main loop needs to know about frame timings
static MainTimerSync main_timer_sync;

bool Main::start() {
	ERR_FAIL_COND_V(!_start_success, false);

	bool hasicon = false;
	String positional_arg;
	String game_path;
	String script;
	bool check_only = false;

#ifdef TOOLS_ENABLED
	String doc_tool_path;
	bool doc_base = true;
	String _export_preset;
	bool export_debug = false;
	bool export_pack_only = false;
	bool converting_project = false;
	bool validating_converting_project = false;
#endif

	main_timer_sync.init(OS::get_singleton()->get_ticks_usec());
	List<String> args = OS::get_singleton()->get_cmdline_args();

	for (int i = 0; i < args.size(); i++) {
		// First check parameters that do not have an argument to the right.

		// Doctest Unit Testing Handler
		// Designed to override and pass arguments to the unit test handler.
		if (args[i] == "--check-only") {
			check_only = true;
#ifdef TOOLS_ENABLED
		} else if (args[i] == "--no-docbase") {
			doc_base = false;
		} else if (args[i] == "--convert-3to4") {
			converting_project = true;
		} else if (args[i] == "--validate-conversion-3to4") {
			validating_converting_project = true;
		} else if (args[i] == "-e" || args[i] == "--editor") {
			editor = true;
		} else if (args[i] == "-p" || args[i] == "--project-manager") {
			project_manager = true;
#endif
		} else if (args[i].length() && args[i][0] != '-' && positional_arg.is_empty()) {
			positional_arg = args[i];

			if (args[i].ends_with(".scn") ||
					args[i].ends_with(".tscn") ||
					args[i].ends_with(".escn") ||
					args[i].ends_with(".res") ||
					args[i].ends_with(".tres")) {
				// Only consider the positional argument to be a scene path if it ends with
				// a file extension associated with Godot scenes. This makes it possible
				// for projects to parse command-line arguments for custom CLI arguments
				// or other file extensions without trouble. This can be used to implement
				// "drag-and-drop onto executable" logic, which can prove helpful
				// for non-game applications.
				game_path = args[i];
			}
		}
		// Then parameters that have an argument to the right.
		else if (i < (args.size() - 1)) {
			bool parsed_pair = true;
			if (args[i] == "-s" || args[i] == "--script") {
				script = args[i + 1];
#ifdef TOOLS_ENABLED
			} else if (args[i] == "--doctool") {
				doc_tool_path = args[i + 1];
				if (doc_tool_path.begins_with("-")) {
					// Assuming other command line arg, so default to cwd.
					doc_tool_path = ".";
					parsed_pair = false;
				}
			} else if (args[i] == "--export-release") {
				editor = true; //needs editor
				_export_preset = args[i + 1];
			} else if (args[i] == "--export-debug") {
				editor = true; //needs editor
				_export_preset = args[i + 1];
				export_debug = true;
			} else if (args[i] == "--export-pack") {
				editor = true;
				_export_preset = args[i + 1];
				export_pack_only = true;
#endif
			} else {
				// The parameter does not match anything known, don't skip the next argument
				parsed_pair = false;
			}
			if (parsed_pair) {
				i++;
			}
		}
#ifdef TOOLS_ENABLED
		// Handle case where no path is given to --doctool.
		else if (args[i] == "--doctool") {
			doc_tool_path = ".";
		}
#endif
	}

	uint64_t minimum_time_msec = GLOBAL_DEF("application/boot_splash/minimum_display_time", 0);
	ProjectSettings::get_singleton()->set_custom_property_info("application/boot_splash/minimum_display_time",
			PropertyInfo(Variant::INT,
					"application/boot_splash/minimum_display_time",
					PROPERTY_HINT_RANGE,
					"0,100,1,or_greater,suffix:ms")); // No negative numbers.

#ifdef TOOLS_ENABLED
	if (!doc_tool_path.is_empty()) {
		// Needed to instance editor-only classes for their default values
		Engine::get_singleton()->set_editor_hint(true);

		// Translate the class reference only when `-l LOCALE` parameter is given.
		if (!locale.is_empty() && locale != "en") {
			load_doc_translations(locale);
		}

		{
			Ref<DirAccess> da = DirAccess::open(doc_tool_path);
			ERR_FAIL_COND_V_MSG(da.is_null(), false, "Argument supplied to --doctool must be a valid directory path.");
		}

		Error err;
		DocTools doc;
		doc.generate(doc_base);

		DocTools docsrc;
		HashMap<String, String> doc_data_classes;
		HashSet<String> checked_paths;
		print_line("Loading docs...");

		for (int i = 0; i < _doc_data_class_path_count; i++) {
			// Custom modules are always located by absolute path.
			String path = _doc_data_class_paths[i].path;
			if (path.is_relative_path()) {
				path = doc_tool_path.path_join(path);
			}
			String name = _doc_data_class_paths[i].name;
			doc_data_classes[name] = path;
			if (!checked_paths.has(path)) {
				checked_paths.insert(path);

				// Create the module documentation directory if it doesn't exist
				Ref<DirAccess> da = DirAccess::create_for_path(path);
				err = da->make_dir_recursive(path);
				ERR_FAIL_COND_V_MSG(err != OK, false, "Error: Can't create directory: " + path + ": " + itos(err));

				print_line("Loading docs from: " + path);
				err = docsrc.load_classes(path);
				ERR_FAIL_COND_V_MSG(err != OK, false, "Error loading docs from: " + path + ": " + itos(err));
			}
		}

		String index_path = doc_tool_path.path_join("doc/classes");
		// Create the main documentation directory if it doesn't exist
		Ref<DirAccess> da = DirAccess::create_for_path(index_path);
		err = da->make_dir_recursive(index_path);
		ERR_FAIL_COND_V_MSG(err != OK, false, "Error: Can't create index directory: " + index_path + ": " + itos(err));

		print_line("Loading classes from: " + index_path);
		err = docsrc.load_classes(index_path);
		ERR_FAIL_COND_V_MSG(err != OK, false, "Error loading classes from: " + index_path + ": " + itos(err));
		checked_paths.insert(index_path);

		print_line("Merging docs...");
		doc.merge_from(docsrc);

		for (const String &E : checked_paths) {
			print_line("Erasing old docs at: " + E);
			err = DocTools::erase_classes(E);
			ERR_FAIL_COND_V_MSG(err != OK, false, "Error erasing old docs at: " + E + ": " + itos(err));
		}

		print_line("Generating new docs...");
		err = doc.save_classes(index_path, doc_data_classes);
		ERR_FAIL_COND_V_MSG(err != OK, false, "Error saving new docs:" + itos(err));

		OS::get_singleton()->set_exit_code(EXIT_SUCCESS);
		return false;
	}

	if (dump_gdnative_interface) {
		GDNativeInterfaceDump::generate_gdnative_interface_file("gdnative_interface.h");
	}

	if (dump_extension_api) {
		NativeExtensionAPIDump::generate_extension_json_file("extension_api.json");
	}

	if (dump_gdnative_interface || dump_extension_api) {
		return false;
	}

	if (converting_project) {
		int exit_code = ProjectConverter3To4(converter_max_kb_file, converter_max_line_length).convert();
		OS::get_singleton()->set_exit_code(exit_code);
		return false;
	}
	if (validating_converting_project) {
		int exit_code = ProjectConverter3To4(converter_max_kb_file, converter_max_line_length).validate_conversion();
		OS::get_singleton()->set_exit_code(exit_code);
		return false;
	}

#endif

	if (script.is_empty() && game_path.is_empty() && String(GLOBAL_GET("application/run/main_scene")) != "") {
		game_path = GLOBAL_GET("application/run/main_scene");
	}

#ifdef TOOLS_ENABLED
	if (!editor && !project_manager && !cmdline_tool && script.is_empty() && game_path.is_empty()) {
		// If we end up here, it means we didn't manage to detect what we want to run.
		// Let's throw an error gently. The code leading to this is pretty brittle so
		// this might end up triggered by valid usage, in which case we'll have to
		// fine-tune further.
		OS::get_singleton()->alert("Couldn't detect whether to run the editor, the project manager or a specific project. Aborting.");
		ERR_FAIL_V_MSG(false, "Couldn't detect whether to run the editor, the project manager or a specific project. Aborting.");
	}
#endif

	MainLoop *main_loop = nullptr;
	if (editor) {
		main_loop = memnew(SceneTree);
	}
	String main_loop_type = GLOBAL_DEF("application/run/main_loop_type", "SceneTree");

	if (!script.is_empty()) {
		Ref<Script> script_res = ResourceLoader::load(script);
		ERR_FAIL_COND_V_MSG(script_res.is_null(), false, "Can't load script: " + script);

		if (check_only) {
			if (!script_res->is_valid()) {
				OS::get_singleton()->set_exit_code(EXIT_FAILURE);
			} else {
				OS::get_singleton()->set_exit_code(EXIT_SUCCESS);
			}
			return false;
		}

		if (script_res->can_instantiate()) {
			StringName instance_type = script_res->get_instance_base_type();
			Object *obj = ClassDB::instantiate(instance_type);
			MainLoop *script_loop = Object::cast_to<MainLoop>(obj);
			if (!script_loop) {
				if (obj) {
					memdelete(obj);
				}
				OS::get_singleton()->alert(vformat("Can't load the script \"%s\" as it doesn't inherit from SceneTree or MainLoop.", script));
				ERR_FAIL_V_MSG(false, vformat("Can't load the script \"%s\" as it doesn't inherit from SceneTree or MainLoop.", script));
			}

			script_loop->set_initialize_script(script_res);
			main_loop = script_loop;
		} else {
			return false;
		}
	} else { // Not based on script path.
		if (!editor && !ClassDB::class_exists(main_loop_type) && ScriptServer::is_global_class(main_loop_type)) {
			String script_path = ScriptServer::get_global_class_path(main_loop_type);
			Ref<Script> script_res = ResourceLoader::load(script_path);
			if (script_res.is_null()) {
				OS::get_singleton()->alert("Error: Could not load MainLoop script type: " + main_loop_type);
				ERR_FAIL_V_MSG(false, vformat("Could not load global class %s.", main_loop_type));
			}
			StringName script_base = script_res->get_instance_base_type();
			Object *obj = ClassDB::instantiate(script_base);
			MainLoop *script_loop = Object::cast_to<MainLoop>(obj);
			if (!script_loop) {
				if (obj) {
					memdelete(obj);
				}
				OS::get_singleton()->alert("Error: Invalid MainLoop script base type: " + script_base);
				ERR_FAIL_V_MSG(false, vformat("The global class %s does not inherit from SceneTree or MainLoop.", main_loop_type));
			}
			script_loop->set_initialize_script(script_res);
			main_loop = script_loop;
		}
	}

	if (!main_loop && main_loop_type.is_empty()) {
		main_loop_type = "SceneTree";
	}

	if (!main_loop) {
		if (!ClassDB::class_exists(main_loop_type)) {
			OS::get_singleton()->alert("Error: MainLoop type doesn't exist: " + main_loop_type);
			return false;
		} else {
			Object *ml = ClassDB::instantiate(main_loop_type);
			ERR_FAIL_COND_V_MSG(!ml, false, "Can't instance MainLoop type.");

			main_loop = Object::cast_to<MainLoop>(ml);
			if (!main_loop) {
				memdelete(ml);
				ERR_FAIL_V_MSG(false, "Invalid MainLoop type.");
			}
		}
	}

	SceneTree *sml = Object::cast_to<SceneTree>(main_loop);
	if (sml) {
#ifdef DEBUG_ENABLED
		if (debug_collisions) {
			sml->set_debug_collisions_hint(true);
		}
		if (debug_paths) {
			sml->set_debug_paths_hint(true);
		}
		if (debug_navigation) {
			sml->set_debug_navigation_hint(true);
			NavigationServer3D::get_singleton()->set_active(true);
			NavigationServer3D::get_singleton_mut()->set_debug_enabled(true);
		}
#endif

		bool embed_subwindows = GLOBAL_DEF("display/window/subwindows/embed_subwindows", true);

		if (single_window || (!project_manager && !editor && embed_subwindows) || !DisplayServer::get_singleton()->has_feature(DisplayServer::Feature::FEATURE_SUBWINDOWS)) {
			sml->get_root()->set_embedding_subwindows(true);
		}

		ResourceLoader::add_custom_loaders();
		ResourceSaver::add_custom_savers();

		if (!project_manager && !editor) { // game
			if (!game_path.is_empty() || !script.is_empty()) {
				//autoload
				Engine::get_singleton()->startup_benchmark_begin_measure("load_autoloads");
				HashMap<StringName, ProjectSettings::AutoloadInfo> autoloads = ProjectSettings::get_singleton()->get_autoload_list();

				//first pass, add the constants so they exist before any script is loaded
				for (const KeyValue<StringName, ProjectSettings::AutoloadInfo> &E : autoloads) {
					const ProjectSettings::AutoloadInfo &info = E.value;

					if (info.is_singleton) {
						for (int i = 0; i < ScriptServer::get_language_count(); i++) {
							ScriptServer::get_language(i)->add_global_constant(info.name, Variant());
						}
					}
				}

				//second pass, load into global constants
				List<Node *> to_add;
				for (const KeyValue<StringName, ProjectSettings::AutoloadInfo> &E : autoloads) {
					const ProjectSettings::AutoloadInfo &info = E.value;

					Node *n = nullptr;
					if (ResourceLoader::get_resource_type(info.path) == "PackedScene") {
						// Cache the scene reference before loading it (for cyclic references)
						Ref<PackedScene> scn;
						scn.instantiate();
						scn->set_path(info.path);
						scn->reload_from_file();
						ERR_CONTINUE_MSG(!scn.is_valid(), vformat("Can't autoload: %s.", info.path));

						if (scn.is_valid()) {
							n = scn->instantiate();
						}
					} else {
						Ref<Resource> res = ResourceLoader::load(info.path);
						ERR_CONTINUE_MSG(res.is_null(), vformat("Can't autoload: %s.", info.path));

						Ref<Script> script_res = res;
						if (script_res.is_valid()) {
							StringName ibt = script_res->get_instance_base_type();
							bool valid_type = ClassDB::is_parent_class(ibt, "Node");
							ERR_CONTINUE_MSG(!valid_type, vformat("Script does not inherit from Node: %s.", info.path));

							Object *obj = ClassDB::instantiate(ibt);

							ERR_CONTINUE_MSG(!obj, vformat("Cannot instance script for autoload, expected 'Node' inheritance, got: %s."));

							n = Object::cast_to<Node>(obj);
							n->set_script(script_res);
						}
					}

					ERR_CONTINUE_MSG(!n, vformat("Path in autoload not a node or script: %s.", info.path));
					n->set_name(info.name);

					//defer so references are all valid on _ready()
					to_add.push_back(n);

					if (info.is_singleton) {
						for (int i = 0; i < ScriptServer::get_language_count(); i++) {
							ScriptServer::get_language(i)->add_global_constant(info.name, n);
						}
					}
				}

				for (Node *E : to_add) {
					sml->get_root()->add_child(E);
				}
				Engine::get_singleton()->startup_benchmark_end_measure(); // load autoloads
			}
		}

#ifdef TOOLS_ENABLED
		EditorNode *editor_node = nullptr;
		if (editor) {
			Engine::get_singleton()->startup_benchmark_begin_measure("editor");
			editor_node = memnew(EditorNode);
			sml->get_root()->add_child(editor_node);

			if (!_export_preset.is_empty()) {
				editor_node->export_preset(_export_preset, positional_arg, export_debug, export_pack_only);
				game_path = ""; // Do not load anything.
			}

			Engine::get_singleton()->startup_benchmark_end_measure();

			editor_node->set_use_startup_benchmark(use_startup_benchmark, startup_benchmark_file);
			// Editor takes over
			use_startup_benchmark = false;
			startup_benchmark_file = String();
		}
#endif
		GLOBAL_DEF_BASIC("display/window/stretch/mode", "disabled");
		ProjectSettings::get_singleton()->set_custom_property_info("display/window/stretch/mode",
				PropertyInfo(Variant::STRING,
						"display/window/stretch/mode",
						PROPERTY_HINT_ENUM,
						"disabled,canvas_items,viewport"));
		GLOBAL_DEF_BASIC("display/window/stretch/aspect", "keep");
		ProjectSettings::get_singleton()->set_custom_property_info("display/window/stretch/aspect",
				PropertyInfo(Variant::STRING,
						"display/window/stretch/aspect",
						PROPERTY_HINT_ENUM,
						"ignore,keep,keep_width,keep_height,expand"));
		GLOBAL_DEF_BASIC("display/window/stretch/scale", 1.0);
		ProjectSettings::get_singleton()->set_custom_property_info("display/window/stretch/scale",
				PropertyInfo(Variant::FLOAT,
						"display/window/stretch/scale",
						PROPERTY_HINT_RANGE,
						"0.5,8.0,0.01"));
		sml->set_auto_accept_quit(GLOBAL_DEF("application/config/auto_accept_quit", true));
		sml->set_quit_on_go_back(GLOBAL_DEF("application/config/quit_on_go_back", true));
		GLOBAL_DEF_BASIC("gui/common/snap_controls_to_pixels", true);
		GLOBAL_DEF_BASIC("gui/fonts/dynamic_fonts/use_oversampling", true);

		GLOBAL_DEF_BASIC("rendering/textures/canvas_textures/default_texture_filter", 1);
		ProjectSettings::get_singleton()->set_custom_property_info(
				"rendering/textures/canvas_textures/default_texture_filter",
				PropertyInfo(Variant::INT, "rendering/textures/canvas_textures/default_texture_filter", PROPERTY_HINT_ENUM,
						"Nearest,Linear,Linear Mipmap,Nearest Mipmap"));
		GLOBAL_DEF_BASIC("rendering/textures/canvas_textures/default_texture_repeat", 0);
		ProjectSettings::get_singleton()->set_custom_property_info(
				"rendering/textures/canvas_textures/default_texture_repeat",
				PropertyInfo(Variant::INT, "rendering/textures/canvas_textures/default_texture_repeat", PROPERTY_HINT_ENUM,
						"Disable,Enable,Mirror"));

		if (!editor && !project_manager) {
			//standard helpers that can be changed from main config

			String stretch_mode = GLOBAL_GET("display/window/stretch/mode");
			String stretch_aspect = GLOBAL_GET("display/window/stretch/aspect");
			Size2i stretch_size = Size2i(GLOBAL_GET("display/window/size/viewport_width"),
					GLOBAL_GET("display/window/size/viewport_height"));
			real_t stretch_scale = GLOBAL_GET("display/window/stretch/scale");

			Window::ContentScaleMode cs_sm = Window::CONTENT_SCALE_MODE_DISABLED;
			if (stretch_mode == "canvas_items") {
				cs_sm = Window::CONTENT_SCALE_MODE_CANVAS_ITEMS;
			} else if (stretch_mode == "viewport") {
				cs_sm = Window::CONTENT_SCALE_MODE_VIEWPORT;
			}

			Window::ContentScaleAspect cs_aspect = Window::CONTENT_SCALE_ASPECT_IGNORE;
			if (stretch_aspect == "keep") {
				cs_aspect = Window::CONTENT_SCALE_ASPECT_KEEP;
			} else if (stretch_aspect == "keep_width") {
				cs_aspect = Window::CONTENT_SCALE_ASPECT_KEEP_WIDTH;
			} else if (stretch_aspect == "keep_height") {
				cs_aspect = Window::CONTENT_SCALE_ASPECT_KEEP_HEIGHT;
			} else if (stretch_aspect == "expand") {
				cs_aspect = Window::CONTENT_SCALE_ASPECT_EXPAND;
			}

			sml->get_root()->set_content_scale_mode(cs_sm);
			sml->get_root()->set_content_scale_aspect(cs_aspect);
			sml->get_root()->set_content_scale_size(stretch_size);
			sml->get_root()->set_content_scale_factor(stretch_scale);

			sml->set_auto_accept_quit(GLOBAL_GET("application/config/auto_accept_quit"));
			sml->set_quit_on_go_back(GLOBAL_GET("application/config/quit_on_go_back"));
			String appname = GLOBAL_GET("application/config/name");
			appname = TranslationServer::get_singleton()->translate(appname);
#ifdef DEBUG_ENABLED
			// Append a suffix to the window title to denote that the project is running
			// from a debug build (including the editor). Since this results in lower performance,
			// this should be clearly presented to the user.
			DisplayServer::get_singleton()->window_set_title(vformat("%s (DEBUG)", appname));
#else
			DisplayServer::get_singleton()->window_set_title(appname);
#endif

			// Define a very small minimum window size to prevent bugs such as GH-37242.
			// It can still be overridden by the user in a script.
			DisplayServer::get_singleton()->window_set_min_size(Size2i(64, 64));

			bool snap_controls = GLOBAL_GET("gui/common/snap_controls_to_pixels");
			sml->get_root()->set_snap_controls_to_pixels(snap_controls);

			bool font_oversampling = GLOBAL_GET("gui/fonts/dynamic_fonts/use_oversampling");
			sml->get_root()->set_use_font_oversampling(font_oversampling);

			int texture_filter = GLOBAL_GET("rendering/textures/canvas_textures/default_texture_filter");
			int texture_repeat = GLOBAL_GET("rendering/textures/canvas_textures/default_texture_repeat");
			sml->get_root()->set_default_canvas_item_texture_filter(
					Viewport::DefaultCanvasItemTextureFilter(texture_filter));
			sml->get_root()->set_default_canvas_item_texture_repeat(
					Viewport::DefaultCanvasItemTextureRepeat(texture_repeat));
		}

#ifdef TOOLS_ENABLED
		if (editor) {
			bool editor_embed_subwindows = EditorSettings::get_singleton()->get_setting(
					"interface/editor/single_window_mode");

			if (editor_embed_subwindows) {
				sml->get_root()->set_embedding_subwindows(true);
			}
		}
#endif

		String local_game_path;
		if (!game_path.is_empty() && !project_manager) {
			local_game_path = game_path.replace("\\", "/");

			if (!local_game_path.begins_with("res://")) {
				bool absolute =
						(local_game_path.size() > 1) && (local_game_path[0] == '/' || local_game_path[1] == ':');

				if (!absolute) {
					if (ProjectSettings::get_singleton()->is_using_datapack()) {
						local_game_path = "res://" + local_game_path;

					} else {
						int sep = local_game_path.rfind("/");

						if (sep == -1) {
							Ref<DirAccess> da = DirAccess::create(DirAccess::ACCESS_FILESYSTEM);
							local_game_path = da->get_current_dir().path_join(local_game_path);
						} else {
							Ref<DirAccess> da = DirAccess::open(local_game_path.substr(0, sep));
							if (da.is_valid()) {
								local_game_path = da->get_current_dir().path_join(
										local_game_path.substr(sep + 1, local_game_path.length()));
							}
						}
					}
				}
			}

			local_game_path = ProjectSettings::get_singleton()->localize_path(local_game_path);

#ifdef TOOLS_ENABLED
			if (editor) {
				if (game_path != String(GLOBAL_GET("application/run/main_scene")) || !editor_node->has_scenes_in_session()) {
					Error serr = editor_node->load_scene(local_game_path);
					if (serr != OK) {
						ERR_PRINT("Failed to load scene");
					}
				}
				DisplayServer::get_singleton()->set_context(DisplayServer::CONTEXT_EDITOR);
				if (!debug_server_uri.is_empty()) {
					EditorDebuggerNode::get_singleton()->start(debug_server_uri);
					EditorDebuggerNode::get_singleton()->set_keep_open(true);
				}
			}
#endif
			if (!editor) {
				DisplayServer::get_singleton()->set_context(DisplayServer::CONTEXT_ENGINE);
			}
		}

		if (!project_manager && !editor) { // game

			Engine::get_singleton()->startup_benchmark_begin_measure("game_load");

			// Load SSL Certificates from Project Settings (or builtin).
			Crypto::load_default_certificates(GLOBAL_GET("network/tls/certificate_bundle_override"));

			if (!game_path.is_empty()) {
				Node *scene = nullptr;
				Ref<PackedScene> scenedata = ResourceLoader::load(local_game_path);
				if (scenedata.is_valid()) {
					scene = scenedata->instantiate();
				}

				ERR_FAIL_COND_V_MSG(!scene, false, "Failed loading scene: " + local_game_path);
				sml->add_current_scene(scene);

#ifdef MACOS_ENABLED
				String mac_iconpath = GLOBAL_GET("application/config/macos_native_icon");
				if (!mac_iconpath.is_empty()) {
					DisplayServer::get_singleton()->set_native_icon(mac_iconpath);
					hasicon = true;
				}
#endif

#ifdef WINDOWS_ENABLED
				String win_iconpath = GLOBAL_GET("application/config/windows_native_icon");
				if (!win_iconpath.is_empty()) {
					DisplayServer::get_singleton()->set_native_icon(win_iconpath);
					hasicon = true;
				}
#endif

				String iconpath = GLOBAL_GET("application/config/icon");
				if ((!iconpath.is_empty()) && (!hasicon)) {
					Ref<Image> icon;
					icon.instantiate();
					if (ImageLoader::load_image(iconpath, icon) == OK) {
						DisplayServer::get_singleton()->set_icon(icon);
						hasicon = true;
					}
				}
			}

			Engine::get_singleton()->startup_benchmark_end_measure(); // game_load
		}

#ifdef TOOLS_ENABLED
		if (project_manager) {
			Engine::get_singleton()->startup_benchmark_begin_measure("project_manager");
			Engine::get_singleton()->set_editor_hint(true);
			ProjectManager *pmanager = memnew(ProjectManager);
			ProgressDialog *progress_dialog = memnew(ProgressDialog);
			pmanager->add_child(progress_dialog);
			sml->get_root()->add_child(pmanager);
			DisplayServer::get_singleton()->set_context(DisplayServer::CONTEXT_PROJECTMAN);
			Engine::get_singleton()->startup_benchmark_end_measure();
		}

		if (project_manager || editor) {
			// Load SSL Certificates from Editor Settings (or builtin)
			Crypto::load_default_certificates(
					EditorSettings::get_singleton()->get_setting("network/tls/editor_tls_certificates").operator String());
		}
#endif
	}

	if (!hasicon && OS::get_singleton()->get_bundle_icon_path().is_empty()) {
		Ref<Image> icon = memnew(Image(app_icon_png));
		DisplayServer::get_singleton()->set_icon(icon);
	}

	OS::get_singleton()->set_main_loop(main_loop);

	if (movie_writer) {
		movie_writer->begin(DisplayServer::get_singleton()->window_get_size(), fixed_fps, Engine::get_singleton()->get_write_movie_path());
	}

	if (minimum_time_msec) {
		uint64_t minimum_time = 1000 * minimum_time_msec;
		uint64_t elapsed_time = OS::get_singleton()->get_ticks_usec();
		if (elapsed_time < minimum_time) {
			OS::get_singleton()->delay_usec(minimum_time - elapsed_time);
		}
	}

	if (use_startup_benchmark) {
		Engine::get_singleton()->startup_dump(startup_benchmark_file);
		startup_benchmark_file = String();
	}

	return true;
}

/* Main iteration
 *
 * This is the iteration of the engine's game loop, advancing the state of physics,
 * rendering and audio.
 * It's called directly by the platform's OS::run method, where the loop is created
 * and monitored.
 *
 * The OS implementation can impact its draw step with the Main::force_redraw() method.
 */

uint64_t Main::last_ticks = 0;
uint32_t Main::frames = 0;
uint32_t Main::hide_print_fps_attempts = 3;
uint32_t Main::frame = 0;
bool Main::force_redraw_requested = false;
int Main::iterating = 0;
bool Main::agile_input_event_flushing = false;

bool Main::is_iterating() {
	return iterating > 0;
}

// For performance metrics.
static uint64_t physics_process_max = 0;
static uint64_t process_max = 0;

bool Main::iteration() {
	//for now do not error on this
	//ERR_FAIL_COND_V(iterating, false);

	iterating++;

	const uint64_t ticks = OS::get_singleton()->get_ticks_usec();
	Engine::get_singleton()->_frame_ticks = ticks;
	main_timer_sync.set_cpu_ticks_usec(ticks);
	main_timer_sync.set_fixed_fps(fixed_fps);

	const uint64_t ticks_elapsed = ticks - last_ticks;

	const int physics_ticks_per_second = Engine::get_singleton()->get_physics_ticks_per_second();
	const double physics_step = 1.0 / physics_ticks_per_second;

	const double time_scale = Engine::get_singleton()->get_time_scale();

	MainFrameTime advance = main_timer_sync.advance(physics_step, physics_ticks_per_second);
	double process_step = advance.process_step;
	double scaled_step = process_step * time_scale;

	Engine::get_singleton()->_process_step = process_step;
	Engine::get_singleton()->_physics_interpolation_fraction = advance.interpolation_fraction;

	uint64_t physics_process_ticks = 0;
	uint64_t process_ticks = 0;

	frame += ticks_elapsed;

	last_ticks = ticks;

	const int max_physics_steps = Engine::get_singleton()->get_max_physics_steps_per_frame();
	if (fixed_fps == -1 && advance.physics_steps > max_physics_steps) {
		process_step -= (advance.physics_steps - max_physics_steps) * physics_step;
		advance.physics_steps = max_physics_steps;
	}

	bool exit = false;

	// process all our active interfaces
	XRServer::get_singleton()->_process();

	for (int iters = 0; iters < advance.physics_steps; ++iters) {
		if (Input::get_singleton()->is_using_input_buffering() && agile_input_event_flushing) {
			Input::get_singleton()->flush_buffered_events();
		}

		Engine::get_singleton()->_in_physics = true;

		uint64_t physics_begin = OS::get_singleton()->get_ticks_usec();

		PhysicsServer3D::get_singleton()->sync();
		PhysicsServer3D::get_singleton()->flush_queries();

		PhysicsServer2D::get_singleton()->sync();
		PhysicsServer2D::get_singleton()->flush_queries();

		if (OS::get_singleton()->get_main_loop()->physics_process(physics_step * time_scale)) {
			exit = true;
			break;
		}

		NavigationServer3D::get_singleton_mut()->process(physics_step * time_scale);

		message_queue->flush();

		PhysicsServer3D::get_singleton()->end_sync();
		PhysicsServer3D::get_singleton()->step(physics_step * time_scale);

		PhysicsServer2D::get_singleton()->end_sync();
		PhysicsServer2D::get_singleton()->step(physics_step * time_scale);

		message_queue->flush();

		physics_process_ticks = MAX(physics_process_ticks, OS::get_singleton()->get_ticks_usec() - physics_begin); // keep the largest one for reference
		physics_process_max = MAX(OS::get_singleton()->get_ticks_usec() - physics_begin, physics_process_max);
		Engine::get_singleton()->_physics_frames++;

		Engine::get_singleton()->_in_physics = false;
	}

	if (Input::get_singleton()->is_using_input_buffering() && agile_input_event_flushing) {
		Input::get_singleton()->flush_buffered_events();
	}

	uint64_t process_begin = OS::get_singleton()->get_ticks_usec();

	if (OS::get_singleton()->get_main_loop()->process(process_step * time_scale)) {
		exit = true;
	}
	message_queue->flush();

	RenderingServer::get_singleton()->sync(); //sync if still drawing from previous frames.

	if (DisplayServer::get_singleton()->can_any_window_draw() &&
			RenderingServer::get_singleton()->is_render_loop_enabled()) {
		if ((!force_redraw_requested) && OS::get_singleton()->is_in_low_processor_usage_mode()) {
			if (RenderingServer::get_singleton()->has_changed()) {
				RenderingServer::get_singleton()->draw(true, scaled_step); // flush visual commands
				Engine::get_singleton()->frames_drawn++;
			}
		} else {
			RenderingServer::get_singleton()->draw(true, scaled_step); // flush visual commands
			Engine::get_singleton()->frames_drawn++;
			force_redraw_requested = false;
		}
	}

	process_ticks = OS::get_singleton()->get_ticks_usec() - process_begin;
	process_max = MAX(process_ticks, process_max);
	uint64_t frame_time = OS::get_singleton()->get_ticks_usec() - ticks;

	for (int i = 0; i < ScriptServer::get_language_count(); i++) {
		ScriptServer::get_language(i)->frame();
	}

	AudioServer::get_singleton()->update();

	if (EngineDebugger::is_active()) {
		EngineDebugger::get_singleton()->iteration(frame_time, process_ticks, physics_process_ticks, physics_step);
	}

	frames++;
	Engine::get_singleton()->_process_frames++;

	if (frame > 1000000) {
		// Wait a few seconds before printing FPS, as FPS reporting just after the engine has started is inaccurate.
		if (hide_print_fps_attempts == 0) {
			if (editor || project_manager) {
				if (print_fps) {
					print_line(vformat("Editor FPS: %d (%s mspf)", frames, rtos(1000.0 / frames).pad_decimals(2)));
				}
			} else if (print_fps || GLOBAL_GET("debug/settings/stdout/print_fps")) {
				print_line(vformat("Project FPS: %d (%s mspf)", frames, rtos(1000.0 / frames).pad_decimals(2)));
			}
		} else {
			hide_print_fps_attempts--;
		}

		Engine::get_singleton()->_fps = frames;
		performance->set_process_time(USEC_TO_SEC(process_max));
		performance->set_physics_process_time(USEC_TO_SEC(physics_process_max));
		process_max = 0;
		physics_process_max = 0;

		frame %= 1000000;
		frames = 0;
	}

	iterating--;

	// Needed for OSs using input buffering regardless accumulation (like Android)
	if (Input::get_singleton()->is_using_input_buffering() && !agile_input_event_flushing) {
		Input::get_singleton()->flush_buffered_events();
	}

	if (movie_writer) {
		RID main_vp_rid = RenderingServer::get_singleton()->viewport_find_from_screen_attachment(DisplayServer::MAIN_WINDOW_ID);
		RID main_vp_texture = RenderingServer::get_singleton()->viewport_get_texture(main_vp_rid);
		Ref<Image> vp_tex = RenderingServer::get_singleton()->texture_2d_get(main_vp_texture);
		movie_writer->add_frame(vp_tex);
	}

	if (fixed_fps != -1) {
		return exit;
	}

	OS::get_singleton()->add_frame_delay(DisplayServer::get_singleton()->window_can_draw());

#ifdef TOOLS_ENABLED
	if (auto_build_solutions) {
		auto_build_solutions = false;
		// Only relevant when running the editor.
		if (!editor) {
			ERR_FAIL_V_MSG(true,
					"Command line option --build-solutions was passed, but no project is being edited. Aborting.");
		}
		if (!EditorNode::get_singleton()->call_build()) {
			ERR_FAIL_V_MSG(true,
					"Command line option --build-solutions was passed, but the build callback failed. Aborting.");
		}
	}
#endif

	return exit || auto_quit;
}

void Main::force_redraw() {
	force_redraw_requested = true;
}

/* Engine deinitialization
 *
 * Responsible for freeing all the memory allocated by previous setup steps,
 * so that the engine closes cleanly without leaking memory or crashing.
 * The order matters as some of those steps are linked with each other.
 */
void Main::cleanup(bool p_force) {
	if (!p_force) {
		ERR_FAIL_COND(!_start_success);
	}

	if (movie_writer) {
		movie_writer->end();
	}

	ResourceLoader::remove_custom_loaders();
	ResourceSaver::remove_custom_savers();

	// Flush before uninitializing the scene, but delete the MessageQueue as late as possible.
	message_queue->flush();

	OS::get_singleton()->delete_main_loop();

	OS::get_singleton()->_cmdline.clear();
	OS::get_singleton()->_user_args.clear();
	OS::get_singleton()->_execpath = "";
	OS::get_singleton()->_local_clipboard = "";

	ResourceLoader::clear_translation_remaps();
	ResourceLoader::clear_path_remaps();

	ScriptServer::finish_languages();

	// Sync pending commands that may have been queued from a different thread during ScriptServer finalization
	RenderingServer::get_singleton()->sync();

	//clear global shader variables before scene and other graphics stuff are deinitialized.
	rendering_server->global_shader_parameters_clear();

	if (xr_server) {
		// Now that we're unregistering properly in plugins we need to keep access to xr_server for a little longer
		// We do however unset our primary interface
		xr_server->set_primary_interface(Ref<XRInterface>());
	}

#ifdef TOOLS_ENABLED
	NativeExtensionManager::get_singleton()->deinitialize_extensions(NativeExtension::INITIALIZATION_LEVEL_EDITOR);
	uninitialize_modules(MODULE_INITIALIZATION_LEVEL_EDITOR);
	unregister_editor_types();

#endif

	ImageLoader::cleanup();

	NativeExtensionManager::get_singleton()->deinitialize_extensions(NativeExtension::INITIALIZATION_LEVEL_SCENE);
	uninitialize_modules(MODULE_INITIALIZATION_LEVEL_SCENE);

	unregister_platform_apis();
	unregister_driver_types();
	unregister_scene_types();

	finalize_theme_db();

	// Before deinitializing server extensions, finalize servers which may be loaded as extensions.
	finalize_physics();

	NativeExtensionManager::get_singleton()->deinitialize_extensions(NativeExtension::INITIALIZATION_LEVEL_SERVERS);
	uninitialize_modules(MODULE_INITIALIZATION_LEVEL_SERVERS);
	unregister_server_types();

	EngineDebugger::deinitialize();

	if (xr_server) {
		memdelete(xr_server);
	}

	if (audio_server) {
		audio_server->finish();
		memdelete(audio_server);
	}

	if (camera_server) {
		memdelete(camera_server);
	}

	OS::get_singleton()->finalize();

	finalize_navigation_server();
	finalize_display();

	if (input) {
		memdelete(input);
	}

	if (packed_data) {
		memdelete(packed_data);
	}
	if (file_access_network_client) {
		memdelete(file_access_network_client);
	}
	if (performance) {
		memdelete(performance);
	}
	if (input_map) {
		memdelete(input_map);
	}
	if (time_singleton) {
		memdelete(time_singleton);
	}
	if (translation_server) {
		memdelete(translation_server);
	}
	if (tsman) {
		memdelete(tsman);
	}
	if (physics_server_3d_manager) {
		memdelete(physics_server_3d_manager);
	}
	if (physics_server_2d_manager) {
		memdelete(physics_server_2d_manager);
	}
	if (globals) {
		memdelete(globals);
	}
	if (engine) {
		memdelete(engine);
	}

	if (OS::get_singleton()->is_restart_on_exit_set()) {
		//attempt to restart with arguments
		List<String> args = OS::get_singleton()->get_restart_on_exit_arguments();
		OS::get_singleton()->create_instance(args);
		OS::get_singleton()->set_restart_on_exit(false, List<String>()); //clear list (uses memory)
	}

	// Now should be safe to delete MessageQueue (famous last words).
	message_queue->flush();
	memdelete(message_queue);

	unregister_core_driver_types();
	unregister_core_extensions();
	uninitialize_modules(MODULE_INITIALIZATION_LEVEL_CORE);
	unregister_core_types();

	OS::get_singleton()->finalize_core();
}