glutAddSubMenu adds a sub-menu trigger to the bottom of the current menu.
Usage
void glutAddSubMenu(char *name, int menu);
Description
glutAddSubMenu adds a sub-menu trigger to the bottom of the current menu. The string name will be displayed for the newly added sub-menu trigger. If the sub-menu trigger is entered, the sub-menu numbered menu will be cascaded, allowing sub-menu menu items to be selected.