Splash screen minimum display time does not work properly on macOS

[bmercury]

Godot version

4.0 beta 5

System information

MacOS Monterey M1

Issue description

Setting the "minimum display time" parameter in project settings under Application>Boot splash does not show the custom image (nor the default one) for that amount of time. Instead when the app is run either from an editor or the project manager, it waits until that time is over and then splashes for a very short time (as if no custom time was set)

This happens when run from the editor.
This happens when run from the project manager.

Steps to reproduce

1. Create a new project
2. Set a custom image for splash screen (or leave default)
3. Set minimum display time to some notable duration (e.g 4 seconds / 4000ms )
4. Run the project
5. The game window is not visible (although shown in the doc)
6. After the time is over (4s in this case) the window is finally shown with the custom splash image(visible for less than a second) and then loads the main scene

Minimal reproduction project

No response

[Calinou]

If you have access to Windows or Linux machines, can you reproduce the issue there? Splash screen drawing is OS-specific.

[bmercury]

If you have access to Windows or Linux machines, can you reproduce the issue there? Splash screen drawing is OS-specific.

Unfortunately I do not have other operating systems available at the moment.

[RumblingTurtle]

If you have access to Windows or Linux machines, can you reproduce the issue there? Splash screen drawing is OS-specific.

Not reproducible on Ubuntu 20.04.4 LTS

[lostminds]

I get the same issue on macOS 13, Godot 4.0.beta7. I set the minimum_display_time to try out and see how a custom boot splash image would appear, but at least on macOS it seems that the wait time that property controls happens before the game window is displayed on screen like @bmercury described.

It seems that this delay is happening in

godot/main/main.cpp

Lines 3062 to 3068 in 829d49b

	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);
	}
	}

which is after the window has been created. But perhaps on macOS the system window server has not yet had time to move the window on screen when the delay happens so it's not visible?

[Calinou]

For reference, this feature was implemented in #41833.

cc @dalexeev

[dalexeev]

I don't have access to macOS and don't know Godot core, but here's what I found.

The boot splash delay occurs at the end of Main::start.

godot/main/main.cpp

Lines 3062 to 3068 in a7937fe

	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);
	}
	}

This function is called in the corresponding main for different platforms.

Details

godot/platform/macos/godot_main_macos.mm

Lines 77 to 89 in a7937fe

	err = Main::setup(argv[0], argc - first_arg, &argv[first_arg]);
	if (err == ERR_HELP) { // Returned by --help and --version, so success.
	return 0;
	} else if (err != OK) {
	return 255;
	}
	if (Main::start()) {
	os.run(); // It is actually the OS that decides how to run.
	}
	Main::cleanup();

godot/platform/linuxbsd/godot_linuxbsd.cpp

Lines 61 to 75 in a7937fe

	Error err = Main::setup(argv[0], argc - 1, &argv[1]);
	if (err != OK) {
	free(cwd);
	if (err == ERR_HELP) { // Returned by --help and --version, so success.
	return 0;
	}
	return 255;
	}
	if (Main::start()) {
	os.set_exit_code(EXIT_SUCCESS);
	os.run(); // it is actually the OS that decides how to run
	}
	Main::cleanup();

godot/platform/windows/godot_windows.cpp

Lines 164 to 181 in a7937fe

	Error err = Main::setup(argv_utf8[0], argc - 1, &argv_utf8[1]);
	if (err != OK) {
	for (int i = 0; i < argc; ++i) {
	delete[] argv_utf8[i];
	}
	delete[] argv_utf8;
	if (err == ERR_HELP) { // Returned by --help and --version, so success.
	return 0;
	}
	return 255;
	}
	if (Main::start()) {
	os.run();
	}
	Main::cleanup();

Inside which the MainLoop functions are called.

Details

godot/platform/macos/os_macos.mm

Lines 665 to 689 in a7937fe

	void OS_MacOS::run() {
	if (!main_loop) {
	return;
	}
	main_loop->initialize();
	bool quit = false;
	while (!quit) {
	@try {
	if (DisplayServer::get_singleton()) {
	DisplayServer::get_singleton()->process_events(); // Get rid of pending events.
	}
	joypad_macos->process_joypads();
	if (Main::iteration()) {
	quit = true;
	}
	} @catch (NSException *exception) {
	ERR_PRINT("NSException: " + String::utf8([exception reason].UTF8String));
	}
	}
	main_loop->finalize();
	}

godot/platform/linuxbsd/os_linuxbsd.cpp

Lines 861 to 884 in a7937fe

	void OS_LinuxBSD::run() {
	if (!main_loop) {
	return;
	}
	main_loop->initialize();
	//uint64_t last_ticks=get_ticks_usec();
	//int frames=0;
	//uint64_t frame=0;
	while (true) {
	DisplayServer::get_singleton()->process_events(); // get rid of pending events
	#ifdef JOYDEV_ENABLED
	joypad->process_joypads();
	#endif
	if (Main::iteration()) {
	break;
	}
	}
	main_loop->finalize();
	}

godot/platform/windows/os_windows.cpp

Lines 1265 to 1280 in a7937fe

	void OS_Windows::run() {
	if (!main_loop) {
	return;
	}
	main_loop->initialize();
	while (true) {
	DisplayServer::get_singleton()->process_events(); // get rid of pending events
	if (Main::iteration()) {
	break;
	}
	}
	main_loop->finalize();
	}

MainLoop::initialize() is the same for all platforms.

godot/core/os/main_loop.cpp

Lines 59 to 65 in a7937fe

	void MainLoop::initialize() {
	if (initialize_script.is_valid()) {
	set_script(initialize_script);
	}
	GDVIRTUAL_CALL(_initialize);
	}

I guess there is some difference between platforms in

if (Main::start()) { 
    os.run();
} 

That is, on MacOS something is called in os.run(), and on other platforms in Main::start() or earlier. But comparing these files, I did not notice any clues.