extern SDL_Surface * screen;
extern text_type black_text, gold_text, white_text, white_small_text, white_big_text, blue_text, red_text, yellow_nums;
-extern int use_gl, use_joystick, use_fullscreen, debug_mode, show_fps;
+extern bool use_gl;
+extern bool use_joystick;
+extern bool use_fullscreen;
+extern bool debug_mode;
+extern bool show_fps;
/** The number of the joystick that will be use in the game */
extern int joystick_num;