Provided by: libsdl3-doc_3.2.10+ds-1_all 

NAME
SDL_WINDOWPOS_UNDEFINED_DISPLAY - Used to indicate that you don't care what the window position is.
HEADER FILE
Defined in SDL3/SDL_video.h
SYNOPSIS
#include "SDL3/SDL.h" #define SDL_WINDOWPOS_UNDEFINED_DISPLAY(X) (SDL_WINDOWPOS_UNDEFINED_MASK|(X))
DESCRIPTION
If you _really_ don't care, SDL_WINDOWPOS_UNDEFINED is the same, but always uses the primary display instead of specifying one.
AVAILABILITY
This macro is available since SDL 3.2.0. Simple Directmedia Layer SDL 3.2.10 SDL_WINDOWPOS_UNDEFINED_DISPLAY(3)