al_get_d3d_system_texture - Allegro 5 API

       Returns  the  system  texture  (stored  with  the D3DPOOL_SYSTEMMEM flags).  This texture is used for the
       render-to-texture feature set.

       Returns: A pointer to the Direct3D system texture.

Allegro reference manual                                                      al_get_d3d_system_texture(3alleg5)

       al_get_d3d_system_texture - Allegro 5 API

              #include <allegro5/allegro_direct3d.h>

              LPDIRECT3DTEXTURE9 al_get_d3d_system_texture(ALLEGRO_BITMAP *bitmap)