request_refresh_rate - Requests a specific refresh rate during graphic mode
switch. Allegro game programming library.
#include <allegro.h>
void request_refresh_rate(int rate);
Requests that the next call to set_gfx_mode() try to use the specified refresh
rate, if possible. Not all drivers are able to control this at all, and even
when they can, not all rates will be possible on all hardware, so the actual
settings may differ from what you requested. After you call set_gfx_mode(),
you can use get_refresh_rate() to find out what was actually selected. At the
moment only the DOS VESA 3.0, X DGA 2.0 and some Windows DirectX drivers
support this function. The speed is specified in Hz, eg. 60, 70. To return to
the normal default selection, pass a rate value of zero. Example:
request_refresh_rate(60);
if (set_gfx_mode(GFX_AUTODETECT, 640, 480, 0, 0) != 0)
abort_on_error("Couldn't set graphic mode!");
if (get_refresh_rate() != 60)
abort_on_error("Couldn't set refresh rate to 60Hz!");
set_gfx_mode(3), get_refresh_rate(3)