NAME
poll_keyboard - Polls the keyboard. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
int poll_keyboard();
DESCRIPTION
Wherever possible, Allegro will read the keyboard input asynchronously
(ie. from inside an interrupt handler), but on some platforms that may
not be possible, in which case you must call this routine at regular
intervals to update the keyboard state variables.
To help you test your keyboard polling code even if you are programming
on a platform that doesn't require it, after the first time that you
call this function Allegro will switch into polling mode, so from that
point onwards you will have to call this routine in order to get any
keyboard input at all, regardless of whether the current driver
actually needs to be polled or not.
The keypressed(), readkey(), and ureadkey() functions call
poll_keyboard() automatically, so you only need to use this function
when accessing the key[] array and key_shifts variable.
RETURN VALUE
Returns zero on success, or a negative number on failure (ie. no
keyboard driver installed).
SEE ALSO
keyboard_needs_poll(3alleg), install_keyboard(3alleg), key(3alleg),
key_shifts(3alleg), excamera(3alleg), exsample(3alleg), exstars(3alleg)