show_video_bitmap - Flips the hardware screen to use the specified page. Allegro game programming

       Attempts to page flip the hardware screen to display the specified video bitmap object, which must be the
       same size as the physical screen, and should have been  obtained  by  calling  the  create_video_bitmap()
       function.

       Allegro  will handle any necessary vertical retrace synchronisation when page flipping, so you don't need
       to call vsync() before it. This means that show_video_bitmap() has the same time delay effects as vsync()
       by default. This can be adjusted with the  "disable_vsync"  config  key  in  the  [graphics]  section  of
       allegro.cfg. Example:

          int current_page;
          BITMAP *video_page[2];
          ...
          /* Create pages for page flipping */
          video_page[0] = create_video_bitmap(SCREEN_W, SCREEN_H);
          video_page[1] = create_video_bitmap(SCREEN_W, SCREEN_H);
          current_page = 0;
          ...
          /* draw the screen and flip pages */
          draw_screen(video_page[current_page]);
          show_video_bitmap(video_page[current_page]);
          current_page = (current_page+1)%2;
          ...

       show_video_bitmap  -  Flips  the  hardware  screen  to  use  the specified page. Allegro game programming
       library.

       Returns zero on success and non-zero on failure.

scroll_screen(3alleg4),       create_video_bitmap(3alleg4),       exaccel(3alleg4),      exflip(3alleg4),
       exupdate(3alleg4)

Allegro                                           version 4.4.3                       show_video_bitmap(3alleg4)

#include<allegro.h>intshow_video_bitmap(BITMAP*bitmap);