Allegro 5 api
#include <allegro5/allegro.h> void al_set_new_display_adapter(int adapter)
Sets the adapter to use for new displays created by the calling thread. The adapter has a monitor attached to it. Information about the monitor can be gotten using al_get_num_video_adapters(3alleg5) and al_get_monitor_info(3alleg5).
To return to the default behaviour, pass ALLEGRO_DEFAULT_DISPLAY_ADAPTER.
al_get_num_video_adapters(3alleg5), al_get_monitor_info(3alleg5)