Next: 7.17 glutMenuStatusFunc Up: 7 Callback Registration Previous: 7.15 glutTabletMotionFunc

## 7.16 glutTabletButtonFunc

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

Usage

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

`func`
  The new entry callback function.

Description

`glutTabletButtonFunc` sets the tablet button callback for the current window. The tablet button callback for a window is called when the window has tablet input focus (normally, when the mouse is in the window) and the user generates tablet button presses. The `button` parameter will be the button number (starting at one). The number of available tablet buttons can be determined with `glutDeviceGet(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` callback 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 generation of tablet button callbacks. When a new window is created, no tablet button callback is initially registered.

Next: 7.17 glutMenuStatusFunc Up: 7 Callback Registration Previous: 7.15 glutTabletMotionFunc