al_get_backbuffer(3)al_get_backbuffer(3)NAMEal_get_backbuffer - Allegro 5 API
SYNOPSIS
#include <allegro5/allegro.h>
ALLEGRO_BITMAP *al_get_backbuffer(ALLEGRO_DISPLAY *display)
DESCRIPTION
Return a special bitmap representing the back-buffer of the display.
Care should be taken when using the backbuffer bitmap (and its sub-bit‐
maps) as the source bitmap (e.g as the bitmap argument to al_draw_bit‐
map(3)). Only untransformed operations are hardware accelerated. This
consists of al_draw_bitmap(3) and al_draw_bitmap_region(3) when the
current transformation is the identity. If the tranformation is not
the identity, or some other drawing operation is used, the call will be
routed through the memory bitmap routines, which are slow. If you need
those operations to be accelerated, then first copy a region of the
backbuffer into a temporary bitmap (via the al_draw_bitmap(3) and
al_draw_bitmap_region(3)), and then use that temporary bitmap as the
source bitmap.
Allegro reference manualal_get_backbuffer(3)