Provided by: libsdl3-doc_3.2.20+ds-2_all 

NAME
SDL_WINDOWPOS_UNDEFINED_DISPLAY - Used to indicate that you don't care what the window position is.
SYNOPSIS
#include <SDL3/SDL_video.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.
MACRO PARAMETERS
X the SDL_DisplayID of the display to use.
AVAILABILITY
This macro is available since SDL 3.2.0.
Simple Directmedia Layer SDL 3.2.20 SDL_WINDOWPOS_UNDEFINED_DISPLAY(3)