Radio buttons usually appear as a group of two or more and, in turn, provide a choice among several options. Thus, we first must create a group, which is accomplished with a call to the constructor

        GLUI_RadioGroup

The constructor requires four parameters, the first of which is a pointer to the panel that will hold the buttons. Similar to creating a spinner, the second and third parameters are a pointer to a live variable and an integer id. We set these to NULL and -1, respectively. The fourth and last parameter is the name of our handler for the button group.

Next, we create each button in the group with a call to

         GLUI_RadioButton

Since we have not need to reference the objects after they are constructed, we do not save the pointers. The constructor has two parameters. The first is a pointer to the group that the button belongs to and the second is a string that labels the button.

The final call we make for establishing our group is to set the button that is initially "on". The buttons within a group are implicitly numbered, starting with 1. Since we want decal to be the initial method, we initialize the groups value with 2, as seen in the call

     methodGroup->set_int_val(2);