request_scroll(3)               Allegro manual               request_scroll(3)



NAME
       request_scroll - Queues a hardware scroll request with triple
       buffering. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>


       int request_scroll(int x, int y);

DESCRIPTION
       This function is used for triple buffering. It requests a hardware
       scroll to the specified position, but returns immediately rather than
       waiting for a retrace. The scroll will then take place during the next
       vertical retrace, but you can carry on running other code in the
       meantime and use the poll_scroll() routine to detect when the flip has
       actually taken place.

       Triple buffering is only possible with certain drivers: you can look at
       the GFX_CAN_TRIPLE_BUFFER bit in the gfx_capabilities flag to see if it
       will work with the current driver.

RETURN VALUE
       This function returns zero on success, non-zero otherwise.


SEE ALSO
       poll_scroll(3), request_video_bitmap(3), gfx_capabilities(3),
       scroll_screen(3)



Allegro                          version 4.2.3               request_scroll(3)
