al_set_display_icon - Allegro 5 API

       Changes  the  icon  associated with the display (window).  Same as al_set_display_icons(3alleg5) with one
       icon.

       al_set_display_icon - Allegro 5 API

al_set_display_icons(3alleg5), al_set_window_title(3alleg5)

Allegro reference manual                                                            al_set_display_icon(3alleg5)

              #include <allegro5/allegro.h>

              void al_set_display_icon(ALLEGRO_DISPLAY *display, ALLEGRO_BITMAP *icon)