al_set_new_window_position - Allegro 5 API

       Sets  where  the  top  left pixel of the client area of newly created windows (non-fullscreen) will be on
       screen, for displays created by the calling thread.   Negative  values  are  allowed  on  some  multihead
       systems.

       To reset to the default behaviour, pass (INT_MAX, INT_MAX).

       al_set_new_window_position - Allegro 5 API

al_get_new_window_position(3alleg5)

Allegro reference manual                                                     al_set_new_window_position(3alleg5)

              #include <allegro5/allegro.h>

              void al_set_new_window_position(int x, int y)