GLenum which,
                                           _GLUfuncptr CallBackFunc )

PARAMETERS
       quad          Specifies    the    quadrics    object    (created    with
                     gluNewQuadric).

       which         Specifies the callback  being  defined.   The  only  valid
                     value is GLU_ERROR.

       CallBackFunc  Specifies the function to be called.

DESCRIPTION
       gluQuadricCallback  is  used  to  define  a new callback to be used by a
       quadrics object.  If the specified callback is already defined, then  it
       is  replaced.  If  CallBackFunc  is  NULL, then any existing callback is
       erased.

       The one legal callback is GLU_ERROR:

       GLU_ERROR      The function is called when an error is encountered.  Its
                      single  argument  is of type GLenum, and it indicates the
                      specific error that occurred.  Character strings describ‐
                      ing these errors can be retrieved with the gluErrorString
                      call.

SEE ALSO
       gluErrorString, gluNewQuadric

                                                         GLUQUADRICCALLBACK(3G)