listener.cpp

This example can be found in examples\cpp\listener\listener.cpp. 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::Listener 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.). On Windows, the Visual Studio project files are configured to use a relative path to the Redist directory as the working directory. If the examples have been copied, please ensure the working directory is still valid.

 
#ifdef WIN32
#include <windows.h>
#else
#include <csignal>
#endif
 
/*
 * Define handler functions required to ensure a clean shutdown of the PST Tracker when the
 * application is terminated.
 */
 
static void Exithandler(int sig);
 
#ifdef WIN32
BOOL WINAPI ConsoleHandler(DWORD CEvent)
{
    Exithandler(CEvent);
    return TRUE;
}
#endif
 
/* End of handler functions */
 
#include <iostream>
#include <thread>
#include <chrono>
#include <atomic>
 
#include "pstsdk_cpp.h"
#include "TrackerExceptions.h"
#include "PstStringIoStream.h"
 
/*
 * Helper function for clear printing of 4x4 matrices.
 */
static inline void PrintMatrix(const PSTech::Utils::PstArray<float, 16>& mat)
{    
    for (int y = 0; y < 4; ++y)
    {
        for (int x = 0; x < 4; ++x)
        {
            std::cout << mat[x + y * 4] << "\t";
        }
        std::cout << "\n";
    }
}
 
/* Control variable for main loop */
static std::atomic<bool> running(true);
 
/* Flag for signaling tracker restart */
static std::atomic<bool> restart(false);
 
/* Number of data points to grab before application termination */
static const uint32_t numberOfSamplesToGrab = 100;
 
/*
 * Implementation of the PSTech::pstsdk::Listener class to receive tracking data.
 */
class MyListener : public PSTech::pstsdk::Listener
{
    /*
     * The OnTrackerData() callback function receives the data as soon as it
     * becomes available and prints the tracking target pose to the command line.
     */
    virtual void OnTrackerData(const PSTech::pstsdk::TrackerData& td)
    {
        static uint32_t samplesGrabbed = 0;
        if (samplesGrabbed++ >= numberOfSamplesToGrab)
            running = false;
 
        for (int d = 0; d < td.targetlist.size(); ++d)
        {
            auto& mat = td.targetlist[d].pose;
            std::cout << "Pose for " << td.targetlist[d].name << "\n";
            PrintMatrix(mat);
        }
    }
 
    /*
     * The OnTrackerMode() callback function receives tracking status information
     * as soon as the tracking mode changes and prints the tracking mode to the
     * command line.
     */
    virtual void OnTrackerMode(const PSTech::pstsdk::TrackerMode mode)
    {
        switch(mode)
        {
        case PSTech::pstsdk::TrackerMode::TRACKING:
            std::cout << "Tracker tracking" << std::endl;
            break;
        case PSTech::pstsdk::TrackerMode::LOWPOWER:
            std::cout << "Tracker paused" << std::endl;
            break;
        case PSTech::pstsdk::TrackerMode::DISCONNECT:
            std::cout << "Tracker disconnected" << std::endl;
            break;
        case PSTech::pstsdk::TrackerMode::RECONNECT:
            std::cout << "Tracker reconnected" << std::endl;
            restart = true; // Tracker reconnects in paused state. Attempt restart.
            break;
        default:
            std::cout << "Mode " << static_cast<int>(mode) << std::endl;
            break;
        }
    }
} listener;
 
/*
 * Implement the exit handler to shut-down the PST Tracker connection on application termination.
 */
static void Exithandler(int sig)
{
    PSTech::pstsdk::Tracker::Shutdown();
    running = false;
}
 
int main(int argc, char *argv[])
{
    // Register the exit handler with the application
#ifdef WIN32
    SetConsoleCtrlHandler((PHANDLER_ROUTINE)ConsoleHandler, TRUE);
#else
    signal(SIGTERM, Exithandler);
    signal(SIGKILL, Exithandler);
    signal(SIGQUIT, Exithandler);
    signal(SIGINT, Exithandler);
#endif
 
    // 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.
#ifdef WIN32
        PSTech::pstsdk::Tracker pst;
#else
        // On Linux, specify the type of grabber that needs to be used as the last parameter: 
        // "basler_ace" for PST HD or "basler_dart" for PST Pico
        PSTech::pstsdk::Tracker pst("","config.cfg","models.db",argv[1]);
#endif
 
        // Check if calibration information is available for all cameras. When this is not the case, provide a warning.
        if (pst.GetUncalibratedCameraUrls(true).size() > 0)
        {
            std::cout << "\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";
            std::cout << "Press enter to continue...\n";
            std::cin.get();
            return 1;
        }
 
        // Print version number of the tracker server being used.
        std::cout << "Running PST Server version " << pst.GetVersionInfo() << "\n";
 
        // Register the listener object to the tracker server.
        pst.AddTrackerListener(&listener);
        
        std::cout << "Put the Reference card in front of the PST in order to see tracking results.\n\n";
        
        // Start the tracker server.
        pst.Start();
        
        // Perform a system check to see if the tracker server is running OK and print the result.
        std::cout << "System check: " << (int)pst.Systemcheck() << "\n";
        
        // Set the frame rate to 30 Hz.
        pst.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().
        std::cout << "Frame rate set to " << pst.GetFramerate() << "\n";
 
        // Main loop, wait for auto-termination.
        while (running)
        {
            // If tracker has reconnected, restart it.
            if(restart)
            {
                pst.Start();
                restart = false;
            }
 
            std::this_thread::sleep_for(std::chrono::milliseconds(100));
        }
    }
    catch (PSTech::TrackerException &e)
    {
        // Catch PSTech::TrackerException exceptions and print error messages.
        std::cout << e.full_description() << "\n";
 
        // Pause command line to see error message.
        std::cout << "Press enter to continue...\n";
        std::cin.get();
    }
 
    // Make sure that the connection to the PST Tracker is shut down properly.
    PSTech::pstsdk::Tracker::Shutdown();
 
    return 0;
}