Example: hwdrivers_kinect_online_offline_example

C++ example source code:

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2021, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

/*
  Example  : kinect-online-offline-demo
  Web page :
  https://www.mrpt.org/Switching_between_reading_live_Kinect_RGBD_dataset_for_debugging

  Purpose  : Demonstrate how to programmatically switch between online Kinect
              grabbing and offline parsing a Rawlog dataset. Refer to the launch
              of the grabbing thread in Test_KinectOnlineOffline()
*/

#include <mrpt/gui.h>
#include <mrpt/hwdrivers/CKinect.h>
#include <mrpt/img/TColor.h>
#include <mrpt/io/CFileGZInputStream.h>
#include <mrpt/maps/CColouredPointsMap.h>
#include <mrpt/obs/CRawlog.h>
#include <mrpt/opengl/CFrustum.h>
#include <mrpt/opengl/CGridPlaneXY.h>
#include <mrpt/opengl/CPlanarLaserScan.h>
#include <mrpt/opengl/CPointCloudColoured.h>
#include <mrpt/opengl/stock_objects.h>
#include <mrpt/serialization/CArchive.h>
#include <mrpt/system/CTicTac.h>
#include <mrpt/system/CTimeLogger.h>

#include <iostream>
#include <memory>

using namespace mrpt;
using namespace mrpt::hwdrivers;
using namespace mrpt::gui;
using namespace mrpt::obs;
using namespace mrpt::system;
using namespace mrpt::img;
using namespace mrpt::serialization;
using namespace mrpt::io;
using namespace std;

// Thread for online/offline capturing: This should be done in another thread
//   specially in the online mode, but also in offline to emulate the
//   possibility
//   of losing frames if our program doesn't process them quickly.
struct TThreadParam
{
    TThreadParam(
        bool _is_online, const string& _rawlog_file = string(),
        bool _generate_3D_pointcloud_in_this_thread = false)
        : is_online(_is_online),
          rawlog_file(_rawlog_file),
          generate_3D_pointcloud_in_this_thread(
              _generate_3D_pointcloud_in_this_thread),
          quit(false),
          Hz(0)
    {
    }

    const bool is_online;
    const string rawlog_file;
    const bool generate_3D_pointcloud_in_this_thread;

    volatile bool quit;
    volatile double Hz;

    CObservation3DRangeScan::Ptr new_obs;
};

// Only for offline operation:
//  Uncoment to force the simulated sensor to run at this given rate.
//  If commented out, the simulated sensor will reproduce the real rate
//  as indicated by timestamps in the dataset.
//#define FAKE_KINECT_FPS_RATE  10   // In Hz

// ----------------------------------------------------
// The online/offline grabbing thread
// ----------------------------------------------------
void thread_grabbing(TThreadParam& p)
{
    try
    {
        typedef std::unique_ptr<CKinect>
            CKinectPtr;  // This assures automatic destruction

        // Only one of these will be actually used:
        CKinectPtr kinect;
        CFileGZInputStream dataset;

        mrpt::system::TTimeStamp dataset_prev_tim = INVALID_TIMESTAMP;
        mrpt::system::TTimeStamp my_last_read_obs_tim = INVALID_TIMESTAMP;

        if (p.is_online)
        {
            // Online:
            // ---------------------
            kinect.reset(new CKinect());

            // Set params:
            kinect->enableGrabRGB(true);
            kinect->enableGrabDepth(true);
            kinect->enableGrabAccelerometers(false);
            kinect->enableGrab3DPoints(p.generate_3D_pointcloud_in_this_thread);

            // Open:
            cout << "Calling CKinect::initialize()...";
            kinect->initialize();
            cout << "OK\n";
        }
        else
        {
            // Offline:
            // ---------------------
            if (!dataset.open(p.rawlog_file))
                throw std::runtime_error(
                    "Couldn't open rawlog dataset file for input...");

            // Set external images directory:
            CImage::setImagesPathBase(
                CRawlog::detectImagesDirectory(p.rawlog_file));
        }

        CTicTac tictac;
        int nImgs = 0;

        while (!p.quit)
        {
            if (p.is_online)
            {
                // Grab new observation from the camera:
                bool there_is_obs = true, hard_error = false;

                // Smart pointers to observations. Memory pooling used inside
                auto obs = CObservation3DRangeScan::Create();
                kinect->getNextObservation(*obs, there_is_obs, hard_error);

                if (hard_error)
                    throw std::runtime_error(
                        "Sensor returned 'hardware error'");
                else if (there_is_obs)
                {
                    // Send object to the main thread:
                    std::atomic_store(&p.new_obs, obs);
                }
            }
            else
            {
                // Offline:
                CSerializable::Ptr obs;
                do
                {
                    try
                    {
                        archiveFrom(dataset) >> obs;
                    }
                    catch (const std::exception& e)
                    {
                        throw std::runtime_error(
                            string(
                                "\nError reading from dataset file (EOF?):\n") +
                            string(e.what()));
                    }
                    ASSERT_(obs);
                } while (!IS_CLASS(*obs, CObservation3DRangeScan));

                // We have one observation:
                CObservation3DRangeScan::Ptr obs3D =
                    std::dynamic_pointer_cast<CObservation3DRangeScan>(obs);
                obs3D->load();  // *Important* This is needed to load the range
                // image if stored as a separate file.

                // Do we have to wait to emulate real-time behavior?
                const mrpt::system::TTimeStamp cur_tim = obs3D->timestamp;
                const mrpt::system::TTimeStamp now_tim = mrpt::system::now();

                if (dataset_prev_tim != INVALID_TIMESTAMP &&
                    my_last_read_obs_tim != INVALID_TIMESTAMP)
                {
#ifndef FAKE_KINECT_FPS_RATE
                    const double At_dataset =
                        mrpt::system::timeDifference(dataset_prev_tim, cur_tim);
#else
                    const double At_dataset = 1.0 / FAKE_KINECT_FPS_RATE;
#endif
                    const double At_actual = mrpt::system::timeDifference(
                        my_last_read_obs_tim, now_tim);

                    const double need_to_wait_ms =
                        1000. * (At_dataset - At_actual);
                    // cout << "[Kinect grab thread] Need to wait (ms): " <<
                    // need_to_wait_ms << endl;
                    if (need_to_wait_ms > 0)
                        std::this_thread::sleep_for(
                            std::chrono::duration<double, std::milli>(
                                need_to_wait_ms));
                }

                // Send observation to main thread:
                std::atomic_store(&p.new_obs, obs3D);

                dataset_prev_tim = cur_tim;
                my_last_read_obs_tim = mrpt::system::now();
            }

            // Update Hz rate estimate
            nImgs++;
            if (nImgs > 10)
            {
                p.Hz = nImgs / tictac.Tac();
                nImgs = 0;
                tictac.Tic();
            }
        }
    }
    catch (const std::exception& e)
    {
        cout << "Exception in Kinect thread: " << e.what() << endl;
        p.quit = true;
    }
}

// ------------------------------------------------------
//              Test_KinectOnlineOffline
// ------------------------------------------------------
void Test_KinectOnlineOffline(
    bool is_online, const string& rawlog_file = string())
{
    // Launch grabbing thread:
    // --------------------------------------------------------
    TThreadParam thrPar(
        is_online, rawlog_file,
        false  // generate_3D_pointcloud_in_this_thread -> Don't, we'll do it in
        // this main thread.
    );

    std::thread thHandle(thread_grabbing, std::ref(thrPar));

    // Wait until data stream starts so we can say for sure the sensor has been
    // initialized OK:
    cout << "Waiting for sensor initialization...\n";
    do
    {
        CObservation3DRangeScan::Ptr newObs = std::atomic_load(&thrPar.new_obs);
        if (newObs && newObs->timestamp != INVALID_TIMESTAMP) break;
        else
            std::this_thread::sleep_for(10ms);
    } while (!thrPar.quit);

    // Check error condition:
    if (thrPar.quit) return;
    cout << "OK! Sensor started to emit observations.\n";

    // Create window and prepare OpenGL object in the scene:
    // --------------------------------------------------------
    mrpt::gui::CDisplayWindow3D win3D("Kinect 3D view", 800, 600);

    win3D.setCameraAzimuthDeg(140);
    win3D.setCameraElevationDeg(20);
    win3D.setCameraZoom(8.0);
    win3D.setFOV(90);
    win3D.setCameraPointingToPoint(2.5, 0, 0);

    mrpt::opengl::CPointCloudColoured::Ptr gl_points =
        mrpt::opengl::CPointCloudColoured::Create();
    gl_points->setPointSize(2.5);

    opengl::COpenGLViewport::Ptr
        viewInt;  // Extra viewports for the RGB images.
    {
        mrpt::opengl::COpenGLScene::Ptr& scene = win3D.get3DSceneAndLock();

        // Create the Opengl object for the point cloud:
        scene->insert(gl_points);
        scene->insert(mrpt::opengl::CGridPlaneXY::Create());
        scene->insert(mrpt::opengl::stock_objects::CornerXYZ());

        const double aspect_ratio = 480.0 / 640.0;
        const int VW_WIDTH =
            400;  // Size of the viewport into the window, in pixel units.
        const int VW_HEIGHT = aspect_ratio * VW_WIDTH;

        // Create an extra opengl viewport for the RGB image:
        viewInt = scene->createViewport("view2d_int");
        viewInt->setViewportPosition(5, 30, VW_WIDTH, VW_HEIGHT);
        win3D.addTextMessage(10, 30 + VW_HEIGHT + 10, "Intensity data", 2);

        win3D.addTextMessage(5, 5, "'o'/'i'-zoom out/in, ESC: quit", 110);

        win3D.unlockAccess3DScene();
        win3D.repaint();
    }

    mrpt::system::TTimeStamp last_obs_tim = INVALID_TIMESTAMP;

    while (win3D.isOpen() && !thrPar.quit)
    {
        CObservation3DRangeScan::Ptr newObs = std::atomic_load(&thrPar.new_obs);
        if (newObs && newObs->timestamp != INVALID_TIMESTAMP &&
            newObs->timestamp != last_obs_tim)
        {
            // It IS a new observation:
            last_obs_tim = newObs->timestamp;

            // Update visualization ---------------------------------------

            win3D.get3DSceneAndLock();

            // Estimated grabbing rate:
            win3D.addTextMessage(
                -350, -13,
                format(
                    "Timestamp: %s",
                    mrpt::system::dateTimeLocalToString(last_obs_tim).c_str()),
                100);
            win3D.addTextMessage(-100, -30, format("%.02f Hz", thrPar.Hz), 101);

            // Show intensity image:
            if (newObs->hasIntensityImage)
            {
                viewInt->setImageView(newObs->intensityImage);  // This is not
                // "_fast" since
                // the intensity
                // image may be
                // needed later
                // on.
            }
            win3D.unlockAccess3DScene();

            // -------------------------------------------------------
            //           Create 3D points from RGB+D data
            //
            // There are several methods to do this.
            //  Switch the #if's to select among the options:
            // See also:
            // https://www.mrpt.org/Generating_3D_point_clouds_from_RGB_D_observations
            // -------------------------------------------------------
            if (newObs->hasRangeImage)
            {
                static mrpt::system::CTimeLogger logger;
                logger.enter("RGBD->3D");

// Pathway: RGB+D --> PCL <PointXYZ> --> XYZ opengl
#if 0
                static pcl::PointCloud<pcl::PointXYZ> cloud;
                logger.enter("RGBD->3D.projectInto");
                newObs->unprojectInto(cloud, false /* without obs.sensorPose */);
                logger.leave("RGBD->3D.projectInto");

                win3D.get3DSceneAndLock();
                logger.enter("RGBD->3D.load in OpenGL");
                    gl_points->loadFromPointsMap(&cloud);
                logger.leave("RGBD->3D.load in OpenGL");
                win3D.unlockAccess3DScene();
#endif

// Pathway: RGB+D --> PCL <PointXYZRGB> --> XYZ+RGB opengl
#if 0
                static pcl::PointCloud<pcl::PointXYZRGB> cloud;
                logger.enter("RGBD->3D.projectInto");
                newObs->unprojectInto(cloud, false /* without obs.sensorPose */);
                logger.leave("RGBD->3D.projectInto");

                win3D.get3DSceneAndLock();
                logger.enter("RGBD->3D.load in OpenGL");
                    gl_points->loadFromPointsMap(&cloud);
                logger.leave("RGBD->3D.load in OpenGL");
                win3D.unlockAccess3DScene();
#endif

// Pathway: RGB+D --> XYZ+RGB opengl
#if 1
                win3D.get3DSceneAndLock();
                logger.enter("RGBD->3D.projectInto");
                mrpt::obs::T3DPointsProjectionParams pp;
                pp.takeIntoAccountSensorPoseOnRobot = false;

                newObs->unprojectInto(*gl_points, pp);

                logger.leave("RGBD->3D.projectInto");
                win3D.unlockAccess3DScene();
#endif

// Pathway: RGB+D --> XYZ+RGB opengl (With a 6D global pose of the robot)
#if 0
                const CPose3D globalPose(1,2,3,10.0_deg,20.0_deg,30.0_deg);
                win3D.get3DSceneAndLock();
                logger.enter("RGBD->3D.projectInto");
                    newObs->unprojectInto(*gl_points, false /* without obs.sensorPose */, &globalPose);
                logger.leave("RGBD->3D.projectInto");
                win3D.unlockAccess3DScene();
#endif

// Pathway: RGB+D --> internal local XYZ pointcloud --> XYZ+RGB point cloud map
// --> XYZ+RGB opengl
#if 0
                // Project 3D points:
                if (!newObs->hasPoints3D)
                {
                logger.enter("RGBD->3D.projectInto");
                    newObs->unprojectInto();
                logger.leave("RGBD->3D.projectInto");
                }

                CColouredPointsMap pntsMap;
                pntsMap.colorScheme.scheme = CColouredPointsMap::cmFromIntensityImage;
                pntsMap.loadFromRangeScan(*newObs);

                win3D.get3DSceneAndLock();
                logger.enter("RGBD->3D.load in OpenGL");
                    gl_points->loadFromPointsMap(&pntsMap);
                logger.leave("RGBD->3D.load in OpenGL");
                win3D.unlockAccess3DScene();
#endif

                logger.leave("RGBD->3D");
            }

            win3D.repaint();
        }  // end update visualization:

        // Process possible keyboard commands:
        // --------------------------------------
        if (win3D.keyHit())
        {
            const int key = tolower(win3D.getPushedKey());

            switch (key)
            {
                // Some of the keys are processed in this thread:
                case 'o':
                    win3D.setCameraZoom(win3D.getCameraZoom() * 1.2);
                    win3D.repaint();
                    break;
                case 'i':
                    win3D.setCameraZoom(win3D.getCameraZoom() / 1.2);
                    win3D.repaint();
                    break;
                case 27:  // ESC
                    thrPar.quit = true;
                    break;
                default: break;
            };
        }

        std::this_thread::sleep_for(1ms);
    }

    cout << "Waiting for grabbing thread to exit...\n";
    thrPar.quit = true;
    thHandle.join();
    cout << "Bye!\n";
}

int main(int argc, char** argv)
{
    try
    {
        // Determine online/offline operation:
        if (argc != 1 && argc != 2)
        {
            cerr << "Usage:\n"
                 << argv[0] << "                  --> Online grab from sensor\n"
                 << argv[0] << " [DATASET.rawlog] --> Offline from dataset\n";
            return 1;
        }

        if (argc == 1)
        {
            // Online
            cout << "Using online operation" << endl;
            Test_KinectOnlineOffline(true);
        }
        else
        {
            // Offline:
            cout << "Using offline operation with: " << argv[1] << endl;
            Test_KinectOnlineOffline(false, string(argv[1]));
        }

        std::this_thread::sleep_for(50ms);
        return 0;
    }
    catch (const std::exception& e)
    {
        std::cerr << "MRPT error: " << mrpt::exception_to_str(e) << std::endl;
        return -1;
    }
    catch (...)
    {
        printf("Another exception!!");
        return -1;
    }
}