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(3alleg), request_video_bitmap(3alleg),
gfx_capabilities(3alleg), scroll_screen(3alleg)