Check if window is (real) fullscreen SDL3

Game Development
1

How would I check if a window is (real) fullscreen without SDL_WINDOW_FULLSCREEN_DESKTOP? (it’s removed in SDL3)

2

There is still SDL_WINDOW_FULLSCREEN. Isn’t that enough?

3

You’re right, I can check whether the window is fullscreen with that, but how would I check if it’s borderless or real fullscreen?

4

I don’t know, but the migration guide says

SDL_WINDOW_FULLSCREEN_DESKTOP has been removed, and you can call SDL_GetWindowFullscreenMode() to see whether an exclusive fullscreen mode will be used or the fullscreen desktop mode will be used when the window is fullscreen.

The docs for SDL_GetWindowFullscreenMode says

Returns a pointer to the fullscreen mode to use or NULL for desktop mode

Does this mean, if SDL_GetWindowFullscreenMode does not return NULL it uses (or will use) “real fullscreen” mode? I haven’t tested so I could be wrong.

5

I have tested, it always returns a pointer

6

Even after calling SDL_SetWindowFullscreenMode(window, NULL); to request “desktop mode”?

7

upon double checking, I misremembered, it always returns NIL whether fullscreen or not

8

I think you still need to check the window flags to know whether it’s in fullscreen.

if (SDL_GetWindowFlags(window) & SDL_WINDOW_FULLSCREEN)
{
	if (SDL_GetWindowFullscreenMode(window) != NULL)
	{
		printf("exclusive fullscreen mode"); // what you call "real fullscreen" 
	}
	else
	{
		printf("desktop fullscreen mode");
	}
}
else
{
	printf("windowed mode");
}

I haven’t got SDL3 installed so I haven’t tested it but this is how I understand it.

2 Likes
9

It works! Thanks!‍‍‍