man key_shifts () - Bitmask containing the current state of modifier keys. Allegro game programming library.
NAME
key_shifts - Bitmask containing the current state of modifier keys. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
extern volatile int key_shifts;
DESCRIPTION
Bitmask containing the current state of shift/ctrl/alt, the special Windows keys, and the accent escape characters. Wherever possible this value will be updated asynchronously, but if keyboard_needs_poll() returns TRUE, you must manually call poll_keyboard() to update it with the current input state. This can contain any of the flags:
KB_SHIFT_FLAG KB_CTRL_FLAG KB_ALT_FLAG KB_LWIN_FLAG KB_RWIN_FLAG KB_MENU_FLAG KB_COMMAND_FLAG KB_SCROLOCK_FLAG KB_NUMLOCK_FLAG KB_CAPSLOCK_FLAG KB_INALTSEQ_FLAG KB_ACCENT1_FLAG KB_ACCENT2_FLAG KB_ACCENT3_FLAG KB_ACCENT4_FLAG
Example:
if (key[KEY_W]) {
if (key_shifts & KB_SHIFT_FLAG) {
/* User is pressing shift + W. */
} else {
/* Hmmm... lower case W then. */
}
}