A variable overriding the display index used in SDL_Vulkan_CreateSurface()
Defined in <SDL3/SDL_hints.h>
#define SDL_HINT_VULKAN_DISPLAY "SDL_VULKAN_DISPLAY"
The display index starts at 0, which is the default.
This hint should be set before calling SDL_Vulkan_CreateSurface()
This hint is available since SDL 3.1.3.