plucky (3) al_get_backbuffer.3alleg5.gz

Provided by: allegro5-doc_5.2.10.1+dfsg-1_all bug

NAME
       al_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-bitmaps) as the source bitmap (e.g as
       the bitmap argument to al_draw_bitmap(3alleg5)).  Only untransformed operations are hardware accelerated.
       These   consist   of   al_draw_bitmap(3alleg5)   and   al_draw_bitmap_region(3alleg5)  when  the  current
       transformation is the identity.  If the transformation  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(3alleg5) and al_draw_bitmap_region(3alleg5)), and then use that temporary
       bitmap as the source bitmap.