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(3alleg4),
request_video_bitmap(3alleg4),
gfx_capabilities(3alleg4),
scroll_screen(3alleg4)