Allegro 5 api
#include <allegro5/allegro.h> void al_set_display_icon(ALLEGRO_DISPLAY *display, ALLEGRO_BITMAP *icon)
Changes the icon associated with the display (window). Same as al_set_display_icons(3alleg5) with one icon.
al_set_display_icons(3alleg5), al_set_window_title(3alleg5)