Provided by: allegro4-doc_4.4.3.1-1_all bug


       vsync - Waits for a vertical retrace to begin. Allegro game programming library.


       #include <allegro.h>

       void vsync();


       Waits  for a vertical retrace to begin. The retrace happens when the electron beam in your
       monitor has reached the bottom of the screen and is moving  back  to  the  top  ready  for
       another  scan.  During  this  short period the graphics card isn't sending any data to the
       monitor, so you can do things to it that aren't possible at other times, such as  altering
       the  palette  without  causing  flickering  (snow).  Allegro will automatically wait for a
       retrace before altering the palette or doing any hardware scrolling, though, so you  don't
       normally need to bother with this function.


       set_palette(3alleg4), scroll_screen(3alleg4)