Used to indicate that you don't care what the window position is.
Defined in <SDL3/SDL_video.h>
#define SDL_WINDOWPOS_UNDEFINED_DISPLAY(X) (SDL_WINDOWPOS_UNDEFINED_MASK|(X))
X | the SDL_DisplayID of the display to use. |
If you really don't care, SDL_WINDOWPOS_UNDEFINED is the same, but always uses the primary display instead of specifying one.
This macro is available since SDL 3.1.3.