glutTabletButtonFunc  - sets the special keyboard callback
       for the current window.

SYNTAX

       void glutTabletButtonFunc(void (*func)(int button, int state,
                                 int x, int y));

ARGUMENTS

       func      The new tablet button callback function.

DESCRIPTION

       glutTabletButtonFunc sets the tablet button  callback  for
       the  current window. The tablet button callback for a win-
       dow is called when the window has tablet input focus (nor-
       mally,  when the mouse is in the window) and the user gen-
       erates tablet button presses. The button parameter will be
       the  button number (starting at one). The number of avail-
       able  tablet  buttons  can  be  determined  with   glutDe-
       viceGet(GLUT_NUM_TABLET_BUTTONS).   The  state  is  either
       GLUT_UP or GLUT_DOWN indicating whether the  callback  was
       due  to a release or press respectively. The x and y call-
       back parameters indicate the window  relative  coordinates
       when the tablet button state changed.

       Registering  a tablet button callback when a tablet device
       is not available is ineffectual and not an error. In  this
       case, no tablet button callbacks will be generated.

       Passing  NULL to glutTabletButtonFunc disables the genera-
       tion of tablet button callbacks. When a new window is cre-
       ated, no tablet button callback is initially registered.

SEE ALSO

       glutTabletMotionFunc, glutDeviceGet, glutMotionFunc,
       glutSpaceballMotionFunc

AUTHOR

       Mark J. Kilgard (mjk@nvidia.com)