A variable that controls what KMSDRM device to use.
Defined in <SDL3/SDL_hints.h>
#define SDL_HINT_KMSDRM_DEVICE_INDEX "SDL_KMSDRM_DEVICE_INDEX"
SDL might open something like "/dev/dri/cardNN" to access KMSDRM functionality, where "NN" is a device index number. SDL makes a guess at the best index to use (usually zero), but the app or user can set this hint to a number between 0 and 99 to force selection.
This hint should be set before SDL is initialized.
This hint is available since SDL 3.0.0.