al_x_set_initial_icon - Allegro 5 API

       On  some  window managers (notably Ubuntu’s Unity) al_set_display_icon doesn’t work and you need to use a
       .desktop file.  But with this function you can set an icon before calling al_create_display.  This  works
       by setting the icon before XMapWindow.

       al_x_set_initial_icon - Allegro 5 API

       5.2.3

              [UnstableAPI]: New API.

Allegro reference manual                                                          al_x_set_initial_icon(3alleg5)

              #include <allegro5/allegro_x.h>

              bool al_x_set_initial_icon(ALLEGRO_BITMAP *bitmap)