/**
 * Function used to retrieve user keyboard input.
 * @return -1 if we don't use that specific key, so we can ignore it.
 *          ASCII value if simple key is pressed or 255+ASCII value if
 *          extended key captured.
 */
int get_keypress() {
    int x, y;
    x = getch();
    switch(x) {
        // check if we've captured an extended key
        case 224: {
            y = getch();
            return 255+y;
        } break;
        default: return x;
    }
}