glutSpaceballButtonFunc - sets the Spaceball button callback for the current
window.
void glutSpaceballButtonFunc(void (*func)(int button, int state));
- func
- The new spaceball button callback function.
glutSpaceballButtonFunc sets the Spaceball button callback for the current
window. The Spaceball button callback for a window is called when the window
has Spaceball input focus (normally, when the mouse is in the window) and the
user generates Spaceball button presses. The button parameter will be the
button number (starting at one). The number of available Spaceball buttons can
be determined with glutDeviceGet(GLUT_NUM_SPACEBALL_BUTTONS). The state is
either GLUT_UP or GLUT_DOWN indicating whether the callback was due to a
release or press respectively.
Registering a Spaceball button callback when a Spaceball device is
not available is ineffectual and not an error. In this case, no Spaceball
button callbacks will be generated.
Passing NULL to glutSpaceballButtonFunc disables the generation of
Spaceball button callbacks. When a new window is created, no Spaceball
button callback is initially registered.
glutSpaceballMotionFunc, glutSpaceballRotateFunc, glutMouseFunc,
glutButtonBoxFunc, glutTabletButtonFunc, glutJoystickFunc, glutDeviceGet
Mark J. Kilgard (mjk@nvidia.com)