request_scroll (3) - Linux Man Pages

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

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.