Video initialization does not take into consideration multi-monitor setups

[MiltosKoutsokeras]

If you have more than one monitors attached to the graphics card, the game automatically uses only the first display returned by SDL_GetNumVideoDisplays and does not consider portrait or landscape displays. If the user has a setup with a primary monitor that is not suitable (portrait display, etc.) there is not option in-game to choose the monitor to use. As a workaround the user can disable the non-suitable monitor (e.g. with xrandr in Linux) prior to launching a game. Not very user-friendly option.

[MiltosKoutsokeras]

Pull request with fix: #96

[arrowgent]

for nvidia in linux:

#set monitor for sdl
#games recognize the two screens as being one big screen 0=full, 1=one screen
export SDL_VIDEO_FULLSCREEN_HEAD=1
#set 0 display 0 set 1 display 1 (left-right)
#export SDL_VIDEO_FULLSCREEN_DISPLAY=1
#prevent window from minimizing when move my mouse to another monitor on Linux when playing in fullscreen mode
export SDL_VIDEO_MINIMIZE_ON_FOCUS_LOSS=0

you can set this in your terminal, in script to launch doom64ex, or your ~/.profile

doom64ex devs could fix this also. as gzdoom has no flaws reguarding this.