get_gfx_mode - Returns the id of the current graphics driver. Allegro game programming library.

       This  function  will  let you determine which graphics driver is currently set by allegro. If no graphics
       driver is set, it will return GFX_NONE.

       get_gfx_mode - Returns the id of the current graphics driver. Allegro game programming library.

       Returns the id of the current graphics driver if there is one, or GFX_NONE if none is set.

set_gfx_mode(3alleg4), is_windowed_mode(3alleg4)

Allegro                                           version 4.4.3                            get_gfx_mode(3alleg4)

#include<allegro.h>intget_gfx_mode();