Configuring nodes

An application would usually want to fully configure a node before it starts streaming data. For that reason, OpenNI defines a flow in which configuration can take place, and once all configuration is set, the node xn::Generator::StartGenerating() method can be called to make it start streaming the data.

The following code creates a depth generator, configures it to VGA resolution, 30 FPS, and then starts it:

// Create a DepthGenerator node
xn::DepthGenerator depth;
nRetVal = depth.Create(context);
// TODO: check error code

XnMapOutputMode outputMode;
outputMode.nXRes = 640;
outputMode.nYRes = 480;
outputMode.nFPS = 30;
nRetVal = depth.SetMapOutputMode(outputMode);
// TODO: check error code

// We're done configuring it. Make it start generating data
nRetVal = context.StartGeneratingAll();
// TODO: check error code

// Main loop
while (bShouldRun)
{
    // Wait for new data to be available
    nRetVal = context.WaitOneUpdateAll(depth);
    if (nRetVal != XN_STATUS_OK)
    {
        printf("Failed updating data: %s\n", xnGetStatusString(nRetVal));
        continue;
    }

    // Take current depth map
    const XnDepthPixel* pDepthMap = depth.GetDepthMap();

    // TODO: process depth map
}