al_get_parent_bitmap - Man Page

#include <allegro5/allegro.h>

ALLEGRO_BITMAP *al_get_parent_bitmap(ALLEGRO_BITMAP *bitmap)

Returns the bitmap this bitmap is a sub-bitmap of. Returns NULL if this bitmap is not a sub-bitmap. This function always returns the real bitmap, and never a sub-bitmap. This might NOT match what was passed to al_create_sub_bitmap(3). Consider this code, for instance:

ALLEGRO_BITMAP* a = al_create_bitmap(512, 512);
ALLEGRO_BITMAP* b = al_create_sub_bitmap(a, 128, 128, 256, 256);
ALLEGRO_BITMAP* c = al_create_sub_bitmap(b, 64, 64, 128, 128);
ASSERT(al_get_parent_bitmap(b) == a && al_get_parent_bitmap(c) == a);

The assertion will pass because only a is a real bitmap, and both b and c are its sub-bitmaps.

5.0.6, 5.1.2

al_create_sub_bitmap(3), al_is_sub_bitmap(3)

al_get_bitmap_x(3), al_get_bitmap_y(3), al_is_sub_bitmap(3), al_reparent_bitmap(3).