al_get_current_shader - Allegro 5 API

       Return the shader of the target bitmap, or NULL if one isn’t being used.

       al_get_current_shader - Allegro 5 API

al_use_shader(3alleg5)

Allegro reference manual                                                          al_get_current_shader(3alleg5)

       5.2.9

              #include <allegro5/allegro.h>

              ALLEGRO_SHADER *al_get_current_shader()