-void set_display_callback(DisplayFuncType display);
-void set_keyboard_callback(KeyboardFuncType keyboard);
-void set_mouse_button_callback(MouseButtonFuncType mouse_button);
-void set_mouse_motion_callback(MouseMotionFuncType mouse_motion);
+typedef void (*DisplayFuncType)(Window* win);
+typedef void (*KeyboardFuncType)(Window* win, int key, bool pressed);
+typedef void (*MouseButtonFuncType)(Window *win, int bn, bool pressed, int x, int y);
+typedef void (*MouseMotionFuncType)(Window *win, int x, int y);