NAME¶
al_get_backbuffer - Allegro 5 API
SYNOPSIS¶
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#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. This consists of
al_draw_bitmap(3alleg5) and al_draw_bitmap_region(3alleg5) 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(3alleg5) and al_draw_bitmap_region(3alleg5)),
and then use that temporary bitmap as the source bitmap.