listener.cs

This example can be found in examples\csharp\listener\listener.cs. When the PST SDK has been installed through the PST Software Suite installer the examples can be found in the Development folder.

This example shows how to implement the PST SDK using the PSTech.Pstsdk.Tracker class and how to receive data and tracker mode changes by implementing the PSTech.Pstsdk.Tracker.TrackerListener class. The example initializes the PST Tracker and grabs 100 datapoints.

In order to be able to run this example, the PST Tracker has to be initialized first. This can be done by starting the PST-Server and the PST-Client applications and making sure the calibration files have been downloaded and a tracking target is available. The tracking target can be the default Reference target or a newly trained or imported target. For more information, please see the Initialization section or check the PST Manual.

When compiling and running this example, please make sure that the required dependencies can be found by the executable (e.g. by copying the Redist directory into the build directory. When the PST SDK has been installed through the PST Software Suite installer the Redist folder can be found in the Development folder.).

// Copyright PS-Tech B.V. All Rights Reserved.
 
using System;
using System.Runtime.InteropServices;
using System.Threading;
using PSTech.Pstsdk;
 
namespace PSTech.Listener
{
    public class Listener
    {
        //Registering control handler function.
        [DllImport("Kernel32")]
        private static extern bool SetConsoleCtrlHandler(ConsoleEventHandler handler, bool add);
 
        private delegate bool ConsoleEventHandler(CtrlType sig);
        static ConsoleEventHandler ConsoleCtrlEventHandler;
 
        public enum CtrlType
        {
            CtrlCEvent = 0,
            CtrlBreakEvent = 1,
            CtrlCloseEvent = 2,
            CtrlLogOffEvent = 5,
            CtrlShutdownEvent = 6,
        }

        private static bool ConsoleHandler(CtrlType sig)
        {
            Exithandler((int)sig);
            return true;
        }

        public static void PrintMatrix(float[] matrix)
        {
            for (int i = 0; i < 4; i++)
            {
                for (int j = 0; j < 4; j++)
                {
                    Console.Write(matrix[j + i * 4] + "\t");
                }
                Console.WriteLine();
            }
        }
 
        // Control variable for main loop.
        static bool Running = true;
 
        // Flag for signaling tracker restart.
        static bool Restart = false;
 
        // Number of data points to grab before application termination
        static int NumberOfSamplesToGrab = 100;
        static int SamplesGrabbed = 0;

        class MyTrackerListener : TrackerListener
        {
            public override void OnTrackerData(TrackerData data, ErrorStatus status)
            {
                if (SamplesGrabbed++ >= NumberOfSamplesToGrab)
                {
                    Running = false;
                }
 
                for (int d = 0; d < data.TargetPoseList.Length; ++d)
                {
                    var mat = data.TargetPoseList[d].PoseMatrix;
                    Console.Write("Pose for " + data.TargetPoseList[d].Target.Name + "\n");
                    PrintMatrix(mat);
                }
            }

            public override void OnTrackerMode(ETrackerMode mode)
            {
                switch (mode)
                {
                    case ETrackerMode.ModeTracking:
                        Console.WriteLine("Tracker tracking");
                        break;
                    case ETrackerMode.ModeLowpower:
                        Console.WriteLine("Tracker paused");
                        break;
                    case ETrackerMode.ModeDisconnect:
                        Console.WriteLine("Tracker disconnected");
                        break;
                    case ETrackerMode.ModeReconnect:
                        Console.WriteLine("Tracker reconnected");
                        Restart = true; // Tracker reconnects in paused state. Attempt restart.
                        break;
                    default:
                        Console.WriteLine("Mode " + (int) mode);
                        break;
                }
            }
        }

        static void Exithandler(int sig)
        {
            Tracker.Shutdown(); // Cleans up native resources only; does NOT remove listeners
            Running = false;
        }
 
        static int Main(string[] args)
        {
            // Register the exit handler with the application
            ConsoleCtrlEventHandler += new ConsoleEventHandler(ConsoleHandler);
            SetConsoleCtrlHandler(ConsoleCtrlEventHandler, true);
 
            // Implement error handling of PSTech.TrackerException exceptions to prevent
            // improper PST Tracker shutdown on errors.
            try
            {
                // Create an instance of the Tracker object using the default configuration path and file names.
                // Wrap the Tracker in a using statement to ensure Dispose() is called automatically
                using (Tracker tracker = new Tracker())
                {
 
                    // Check if calibration information is available for all cameras. When this is not the case, provide a warning.
                    if (tracker.GetUncalibratedCameraUrls().Length > 0)
                    {
                        Console.Write("\nNo calibration information could be found in the configuration directory. " +
                                     "Please use the PST Server and PST Client application to initialize the PST Tracker and create/import a tracking target. " +
                                     "More information can be found in the Initialization section of the PST SDK manual and the PST Manual.\n\n");
                        Console.Write("Press enter to continue...\n");
                        Console.Read();
                        return 1;
                    }
 
                    // Print version number of the tracker server being used.
                    Console.Write("Running PST Server version " + tracker.GetVersionInfo() + "\n");
 
                    //Create tracker listener with callback functions for data and/or mode updates.
                    TrackerListener listener = new MyTrackerListener();
 
                    // Register the TrackerListener object to the tracker server.
                    tracker.AddTrackerListener(listener);
 
                    Console.Write("Put the Reference card in front of the PST in order to see tracking results.\n\n");
 
                    // Start the tracker server.
                    tracker.StartTracker();
 
                    // Perform a system check to see if the tracker server is running OK and print the result.
                    Console.Write("System check: " + tracker.Systemcheck() + "\n");
 
                    // Set the frame rate to 30 Hz.
                    tracker.SetFramerate(30);
 
                    // Print the new frame rate to see if it was set correctly. Note that for PST HD and Pico
                    // trackers the frame rate actually being set can differ from the value provided to SetFramerate().
                    Console.Write("Frame rate set to " + tracker.GetFramerate() + "\n");
 
                    // Main loop, wait for auto-termination.
                    while (Running)
                    {
                        // If tracker has reconnected, restart it.
                        if (Restart)
                        {
                            tracker.StartTracker();
                            Restart = false;
                        }
 
                        Thread.Sleep(100); ;
                    }
                }
            }
            catch (Exception e)
            {
                // Catch PSTech.TrackerException exceptions and print error messages.
                Console.Write(e + "\n");
                // Pause command line to see error message.
                Console.Write("Press enter to continue...\n");
                Console.Read();
            }
 
            return 0;
        }
    }
}