#include <pcl/io/openni_grabber.h>
#include <pcl/visualization/cloud_viewer.h>
#include <pcl/io/pcd_io.h>

class SimpleOpenNIViewer
{
public:
   SimpleOpenNIViewer () : viewer ("PCL OpenNI Viewer") {}

   void cloud_cb_2_ (const pcl::PointCloud<pcl::PointXYZRGBA>::ConstPtr &cloud)
   {
      //do nothing...
   }

   void cloud_cb_ (const pcl::PointCloud<pcl::PointXYZRGBA>::ConstPtr &cloud)
   {
      //show cloud
      if (!viewer.wasStopped())
         viewer.showCloud (cloud);
   }

   void run ()
   {
      //**********************************
      //start first kinect
      pcl::Grabber* interface = new pcl::OpenNIGrabber("#1");

      boost::function<void (const pcl::PointCloud<pcl::PointXYZRGBA>::ConstPtr&)> f =
         boost::bind (&SimpleOpenNIViewer::cloud_cb_, this, _1);

      interface->registerCallback (f);
      interface->start();
      //**********************************

      //**********************************
      //start second kinect
       pcl::Grabber* interface2 = new pcl::OpenNIGrabber("#2");
       boost::function<void (const pcl::PointCloud<pcl::PointXYZRGBA>::ConstPtr&)> f2 =
         boost::bind (&SimpleOpenNIViewer::cloud_cb_2_, this, _1);

       interface2->registerCallback (f2);

       interface2->start();
      //**********************************


       while (!viewer.wasStopped())
       {
         sleep (1);
       }

       interface->stop ();
       interface2->stop ();
     }

     pcl::visualization::CloudViewer viewer;
 };

 int main ()
 {
   SimpleOpenNIViewer v;
   v.run ();
   return 0;
 }