create_video_bitmap (3) - Linux Man Pages
create_video_bitmap: Creates a video memory bitmap. Allegro game programming library.
NAMEcreate_video_bitmap - Creates a video memory bitmap. Allegro game programming library.
DESCRIPTIONAllocates a video memory bitmap of the specified size. This can be used to allocate offscreen video memory for storing source graphics ready for a hardware accelerated blitting operation, or to create multiple video memory pages which can then be displayed by calling show_video_bitmap(). Read the introduction of this chapter for a comparison with other types of bitmaps and other specific details.
Warning: video memory bitmaps are usually allocated from the same space as the screen bitmap, so they may overlap with it; it is therefore not a good idea to use the global screen at the same time as any surfaces returned by this function.