No matter how
complex XVR programs get, they are always based on 5 fundamental
functions;
these are the only predefined functions, and they constitute the bases
of any
project.
This is the place
where to put the initialisation code for the app. All commands are
executed
sequentially. All the other functions are not active until OnInit()
complete
its execution.
This is the place
for functions and calls that produce graphics output. This is the only
function
where the graphics context is visible. Placing graphics command outside
this
function would produce no results.
This function runs
indipendently by OnFrame and it’s the perfect place where to put
commands that
must be independent from the rendering task. Also, the timer is hi-res,
and you
can setup some parameters so that this function can be called up to 1k
times
per second.
This function is independend from both OnInit() and OnFrame(); it gets called whenever the application receive an event message. Event messages can be external (i.e. some Windows messages) or internal (i.e. generated anywhere in the XVR program). Events and Messages are supported in XVR cause they add flexibility to the programming environment for task where fixed timers are not the best option. If your app does not need them, you can ignore this function.
This function is
called when the app quits or the user closes the page your app is in.
If
you want
to be sure to perform some operations on exit, place your code here.