Is there a code like SDL_VIDEO_CENTERED=1

I’m looking for make DOSBox svn window set to
center of gameshell screen.
I found sdl code. there is SDL_VIDEO_CENTERED=1 this code.
and gameshell does has code like that one?

SDL_VIDEO_CENTERED=1 is a env variable

not sure what you mean

I think this code is nothing to do with gameshell self, you can use it and the DOSBox svn window should be in the center

yep Im using DOSBox svn.
but with surface option window is not being in the center…
surface mod is faster than overlay… but if I change to fullscreen
then overlay mod is only choice…

then I guess DosBox svn surface mod should do something to deal the SDL_VIDEO_CENTERED=1

SDL self won’t auto deal with the SDL_VIDEO_CENTERED=1

yep but now I cant know where I can fix that SDL_VIDEO_CENTERED=1