al_get_bitmap_depth - Man Page
Allegro 5 API
Synopsis
#include <allegro5/allegro.h> int al_get_bitmap_depth(ALLEGRO_BITMAP *bitmap)
Description
Return the depthbuffer depth used by this bitmap if it is used with al_set_target_bitmap(3).
Since
5.2.1
[Unstable API]: This is an experimental feature and currently only works for the OpenGL backend.
Info
Allegro reference manual