Next: 7.10 glutSpaceballMotionFunc Up: 7 Callback Registration Previous: 7.8 glutEntryFunc

## 7.9 glutSpecialFunc

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

Usage

    void glutSpecialFunc(void (*func)(int key, int x, int y));

`func`
  The new entry callback function.

Description

`glutSpecialFunc` sets the special keyboard callback for the current window. The special keyboard callback is triggered when keyboard function or directional keys are pressed. The `key` callback parameter is a `GLUT_KEY_`* constant for the special key pressed. The `x` and `y` callback parameters indicate the mouse in window relative coordinates when the key was pressed. When a new window is created, no special callback is initially registered and special key strokes in the window are ignored. Passing `NULL` to `glutSpecialFunc` disables the generation of special callbacks.

During a special callback, `glutGetModifiers` may be called to determine the state of modifier keys when the keystroke generating the callback occurred.

An implementation should do its best to provide ways to generate all the `GLUT_KEY_`* special keys. The available `GLUT_KEY_`* values are:

`GLUT_KEY_F1`
  F1 function key.
`GLUT_KEY_F2`
  F2 function key.
`GLUT_KEY_F3`
  F3 function key.
`GLUT_KEY_F4`
  F4 function key.
`GLUT_KEY_F5`
  F5 function key.
`GLUT_KEY_F6`
  F6 function key.
`GLUT_KEY_F7`
  F7 function key.
`GLUT_KEY_F8`
  F8 function key.
`GLUT_KEY_F9`
  F9 function key.
`GLUT_KEY_F10`
  F10 function key.
`GLUT_KEY_F11`
  F11 function key.
`GLUT_KEY_F12`
  F12 function key.
`GLUT_KEY_LEFT`
  Left directional key.
`GLUT_KEY_UP`
  Up directional key.
`GLUT_KEY_RIGHT`
  Right directional key.
`GLUT_KEY_DOWN`
  Down directional key.
`GLUT_KEY_PAGE_UP`
  Page up directional key.
`GLUT_KEY_PAGE_DOWN`
  Page down directional key.
`GLUT_KEY_HOME`
  Home directional key.
`GLUT_KEY_END`
  End directional key.
`GLUT_KEY_INSERT`
  Inset directional key.

Note that the escape, backspace, and delete keys are generated as an ASCII character.

Next: 7.10 glutSpaceballMotionFunc Up: 7 Callback Registration Previous: 7.8 glutEntryFunc