Event-based reading of users' data

You don't need to call nite::UserTracker::readFrame() and wait for it to return each time you want to read a frame of data from nite::UserTracker. This is because NiTE developers give us this ability to define a callback (also known as event listener) when a new frame becomes available, just as openni::VideoStream does. In this recipe, we are going to cover this feature and rewrite the first recipe of this chapter, this time based on events.

Getting ready

Create a project in Visual Studio and prepare it for working with OpenNI and NiTE using the Create a project in Visual Studio 2010 recipe in Chapter 2, OpenNI and C++.

How to do it...

1. Add the ReadLastCharOfLine() function from previous recipes to the top of your source code (just below #include lines).

2. Then add the HandleStatus() function from the previous recipe, right after the ReadLastCharOfLine() function.

3. Add these lines after the definition of the HandleStatus() function:

   struct uTrackerNewFrameListener...