Parameters
cbfun
Pointer to a callback function that will be called every time the mouse wheel is moved. The
function should have the following C language prototype:
void GLFWCALL functionname( int pos );
Where functionname is the name of the callback function, and pos is the mouse wheel position.
If cbfun is NULL, any previously selected callback function will be deselected.
Return values
none
Description
The function selects which function to be called upon a mouse wheel event.
A window has to be opened for this function to have any effect.
Notes
Mouse wheel events are recorded continuously, but only reported when glfwPollEvents,
glfwWaitEvents or glfwSwapBuffers is called.