AROgre.cpp

Example of augmented reality based on Ogre3D.

/****************************************************************************
 *
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2023 by Inria. All rights reserved.
 *
 * This software is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See https://visp.inria.fr for more information.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
 * Inria at visp@inria.fr
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Description:
 * Implementation of a simple augmented reality application using the vpAROgre
 * class.
 *
*****************************************************************************/
 
#include <iostream>
#include <visp3/core/vpConfig.h>
 
//#if defined(VISP_HAVE_OGRE) && (defined(VISP_HAVE_OPENCV) ||
// defined(VISP_HAVE_GDI) || defined(VISP_HAVE_D3D9) || defined(VISP_HAVE_GTK)
//|| (defined(VISP_HAVE_X11) && ! defined(APPLE)))
#if defined(VISP_HAVE_OGRE) &&                                                                                         \
    (defined(VISP_HAVE_OPENCV) || defined(VISP_HAVE_GDI) || defined(VISP_HAVE_D3D9) || defined(VISP_HAVE_GTK) ||       \
     (defined(VISP_HAVE_X11) && !(defined(__APPLE__) && defined(__MACH__))))
 
//#if defined(VISP_HAVE_X11) && ! defined(APPLE)
#if defined(VISP_HAVE_X11) && !(defined(__APPLE__) && defined(__MACH__))
// produce an error on OSX: ‘typedef int Cursor’
// /usr/X11R6/include/X11/X.h:108: error: ‘Cursor’ has a previous
// declaration as ‘typedef XID Cursor’. That's why it should not be
// used on APPLE platforms
#include <visp3/gui/vpDisplayX.h>
#endif
#include <visp3/ar/vpAROgre.h>
#include <visp3/blob/vpDot2.h>
#include <visp3/core/vpDebug.h>
#include <visp3/core/vpImagePoint.h>
#include <visp3/core/vpIoTools.h>
#include <visp3/core/vpPixelMeterConversion.h>
#include <visp3/core/vpPoint.h>
#include <visp3/gui/vpDisplayD3D.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/io/vpParseArgv.h>
#include <visp3/io/vpVideoReader.h>
#include <visp3/vision/vpPose.h>
 
// List of allowed command line options
#define GETOPTARGS "ci:p:h"
 
#ifdef ENABLE_VISP_NAMESPACE
using namespace VISP_NAMESPACE_NAME;
#endif
 
void usage(const char *name, const char *badparam, std::string ipath, std::string ppath)
{
#if VISP_HAVE_DATASET_VERSION >= 0x030600
  std::string ext("png");
#else
  std::string ext("pgm");
#endif
 
  fprintf(stdout, "\n\
Test augmented reality using the vpAROgre class.\n\
\n\
SYNOPSIS\n\
  %s [-i <test image path>] [-p <personal image path>]\n\
     [-c] [-h]\n", name);
 
  fprintf(stdout, "\n\
OPTIONS:                                               Default\n\
  -i <input image path>                                %s\n\
     Set image input path.\n\
     From this path read images \n\
     \"mire-2/image.%%04d.%s\". These \n\
     images come from visp-images-x.y.z.tar.gz available \n\
     on the ViSP website.\n\
     Setting the VISP_INPUT_IMAGE_PATH environment\n\
     variable produces the same behaviour than using\n\
     this option.\n\
 \n\
 -p <personal image path>                             %s\n\
     Specify a personal sequence containing images \n\
     to process.\n\
     By image sequence, we mean one file per image.\n\
     Example : \"/Temp/visp-images/cube/image.%%04d.%s\"\n\
     %%04d is for the image numbering.\n\
\n\
  -c\n\
     Disable the mouse click. Useful to automate the \n\
     execution of this program without human intervention.\n\
\n\
  -h\n\
     Print the help.\n",
          ipath.c_str(), ext.c_str(), ppath.c_str(), ext.c_str());
 
  if (badparam)
    fprintf(stdout, "\nERROR: Bad parameter [%s]\n", badparam);
}
bool getOptions(int argc, const char **argv, std::string &ipath, std::string &ppath, bool &click_allowed)
{
  const char *optarg_;
  int c;
  while ((c = vpParseArgv::parse(argc, argv, GETOPTARGS, &optarg_)) > 1) {
 
    switch (c) {
    case 'c':
      click_allowed = false;
      break;
    case 'i':
      ipath = optarg_;
      break;
    case 'p':
      ppath = optarg_;
      break;
    case 'h':
      usage(argv[0], nullptr, ipath, ppath);
      return false;
      break;
 
    default:
      usage(argv[0], optarg_, ipath, ppath);
      return false;
      break;
    }
  }
 
  if ((c == 1) || (c == -1)) {
    // standalone param or error
    usage(argv[0], nullptr, ipath, ppath);
    std::cerr << "ERROR: " << std::endl;
    std::cerr << "  Bad argument " << optarg_ << std::endl << std::endl;
    return false;
  }
 
  return true;
}
 
#ifndef DOXYGEN_SHOULD_SKIP_THIS
 
class vpAROgreExample : public vpAROgre
{
public:
  // The constructor doesn't change here
  vpAROgreExample(const vpCameraParameters &cam = vpCameraParameters(), unsigned int width = 640,
                  unsigned int height = 480, const char *resourcePath = nullptr)
    : vpAROgre(cam, width, height)
  {
    // Direction vectors
    if (resourcePath)
      mResourcePath = resourcePath;
    std::cout << "mResourcePath: " << mResourcePath << std::endl;
    vecDevant = Ogre::Vector3(0, -1, 0);
    robot = nullptr;
    mAnimationState = nullptr;
  }
 
protected:
  // Attributes
  // Vector to move
  Ogre::Vector3 vecDevant;
  // Animation attribute
  Ogre::AnimationState *mAnimationState;
  // The entity representing the robot
  Ogre::Entity *robot;
 
  // Our scene will just be a plane
  void createScene()
  {
    // Lumieres
    mSceneMgr->setAmbientLight(Ogre::ColourValue((float)0.6, (float)0.6, (float)0.6)); // Default value of lightning
    Ogre::Light *light = mSceneMgr->createLight();
    light->setDiffuseColour(1.0, 1.0, 1.0);  // scaled RGB values
    light->setSpecularColour(1.0, 1.0, 1.0); // scaled RGB values
    // Lumiere ponctuelle
    light->setPosition(-5, -5, 10);
    light->setType(Ogre::Light::LT_POINT);
    light->setAttenuation((Ogre::Real)100, (Ogre::Real)1.0, (Ogre::Real)0.045, (Ogre::Real)0.0075);
    // Ombres
    light->setCastShadows(true);
 
    // Create the Entity
    robot = mSceneMgr->createEntity("Robot", "robot.mesh");
    // Attach robot to scene graph
    Ogre::SceneNode *RobotNode = mSceneMgr->getRootSceneNode()->createChildSceneNode("Robot");
    RobotNode->attachObject(robot);
    RobotNode->scale((Ogre::Real)0.001, (Ogre::Real)0.001, (Ogre::Real)0.001);
    RobotNode->pitch(Ogre::Degree(90));
    RobotNode->yaw(Ogre::Degree(-90));
    robot->setCastShadows(true);
    mSceneMgr->setShadowTechnique(Ogre::SHADOWTYPE_STENCIL_MODULATIVE);
 
    // Add an animation
    // Set the good animation
    mAnimationState = robot->getAnimationState("Idle");
    // Start over when finished
    mAnimationState->setLoop(true);
    // Animation enabled
    mAnimationState->setEnabled(true);
 
    // Add a ground
    Ogre::Plane plan;
    plan.d = 0;
    plan.normal = Ogre::Vector3::UNIT_Z;
    Ogre::MeshManager::getSingleton().createPlane("sol", Ogre::ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME, plan,
                                                  (Ogre::Real)0.22, (Ogre::Real)0.16, 10, 10, true, 1, 1, 1);
    Ogre::Entity *ent = mSceneMgr->createEntity("Entitesol", "sol");
    Ogre::SceneNode *PlaneNode = mSceneMgr->getRootSceneNode()->createChildSceneNode("Entitesol");
    PlaneNode->attachObject(ent);
    ent->setMaterialName("Examples/GrassFloor");
  }
 
  bool customframeEnded(const Ogre::FrameEvent &evt)
  {
    // Update animation
    // To move, we add it the time since last frame
    mAnimationState->addTime(evt.timeSinceLastFrame);
    return true;
  }
 
#ifdef VISP_HAVE_OIS
  bool processInputEvent(const Ogre::FrameEvent & /*evt*/)
  {
    mKeyboard->capture();
    Ogre::Matrix3 rotmy;
    double angle = -M_PI / 8;
    if (mKeyboard->isKeyDown(OIS::KC_ESCAPE))
      return false;
 
    // Event telling that we will have to move, setting the animation to
    // "walk", if false, annimation goes to "Idle"
    bool event = false;
    // Check entries
    if (mKeyboard->isKeyDown(OIS::KC_Z) || mKeyboard->isKeyDown(OIS::KC_UP)) {
      mSceneMgr->getSceneNode("Robot")->setPosition(mSceneMgr->getSceneNode("Robot")->getPosition() +
                                                    (Ogre::Real)0.003 * vecDevant);
      event = true;
    }
    if (mKeyboard->isKeyDown(OIS::KC_S) || mKeyboard->isKeyDown(OIS::KC_DOWN)) {
      mSceneMgr->getSceneNode("Robot")->setPosition(mSceneMgr->getSceneNode("Robot")->getPosition() -
                                                    (Ogre::Real)0.003 * vecDevant);
      event = true;
    }
    if (mKeyboard->isKeyDown(OIS::KC_Q) || mKeyboard->isKeyDown(OIS::KC_LEFT)) {
      rotmy = Ogre::Matrix3((Ogre::Real)cos(-angle), (Ogre::Real)sin(-angle), 0, (Ogre::Real)(-sin(-angle)),
                            (Ogre::Real)cos(-angle), 0, 0, 0, 1);
      vecDevant = vecDevant * rotmy;
      mSceneMgr->getSceneNode("Robot")->yaw(Ogre::Radian((Ogre::Real)(-angle)));
      event = true;
    }
    if (mKeyboard->isKeyDown(OIS::KC_D) || mKeyboard->isKeyDown(OIS::KC_RIGHT)) {
      rotmy = Ogre::Matrix3((Ogre::Real)cos(angle), (Ogre::Real)sin(angle), 0, (Ogre::Real)(-sin(angle)),
                            (Ogre::Real)cos(angle), 0, 0, 0, 1);
      vecDevant = vecDevant * rotmy;
      mSceneMgr->getSceneNode("Robot")->yaw(Ogre::Radian((Ogre::Real)angle));
      event = true;
    }
 
    // Play the right animation
    if (event) {
      mAnimationState = robot->getAnimationState("Walk");
    }
    else
      mAnimationState = robot->getAnimationState("Idle");
 
    // Start over when finished
    mAnimationState->setLoop(true);
    // Animation enabled
    mAnimationState->setEnabled(true);
 
    return true;
  }
#endif
};
 
void computeInitialPose(vpCameraParameters *mcam, vpImage<unsigned char> &I, vpPose *mPose, vpDot2 *md,
                        vpImagePoint *mcog, vpHomogeneousMatrix *cMo, vpPoint *mP, const bool &opt_click_allowed)
{
  // ---------------------------------------------------
  //    Code inspired from ViSP example of camera pose
  // ----------------------------------------------------
  bool opt_display = true;
 
  //#if defined(VISP_HAVE_X11) && ! defined(APPLE)
#if defined(VISP_HAVE_X11) && !(defined(__APPLE__) && defined(__MACH__))
  // produce an error on OSX: ‘typedef int Cursor’
  // /usr/X11R6/include/X11/X.h:108: error: ‘Cursor’ has a previous
  // declaration as ‘typedef XID Cursor’. That's why it should not be
  // used on APPLE platforms
  vpDisplayX display;
#elif defined(VISP_HAVE_GTK)
  vpDisplayGTK display;
#elif defined(VISP_HAVE_GDI)
  vpDisplayGDI display;
#elif defined(HAVE_OPENCV_HIGHGUI)
  vpDisplayOpenCV display;
#elif defined(VISP_HAVE_D3D9)
  vpDisplayD3D display;
#endif
  for (unsigned int i = 0; i < 4; i++) {
    if (opt_display) {
      md[i].setGraphics(true);
    }
    else {
      md[i].setGraphics(false);
    }
  }
 
  if (opt_display) {
    try {
      // Display size is automatically defined by the image (I) size
      display.init(I, 100, 100, "Preliminary Pose Calculation");
      // display the image
      // The image class has a member that specify a pointer toward
      // the display that has been initialized in the display declaration
      // therefore is is no longer necessary to make a reference to the
      // display variable.
      vpDisplay::display(I);
      // Flush the display
      vpDisplay::flush(I);
 
    }
    catch (...) {
      vpERROR_TRACE("Error while displaying the image");
      return;
    }
  }
 
  std::cout << "*************************************************************"
    "***********************"
    << std::endl;
  std::cout << "*************************** Preliminary Pose Calculation "
    "***************************"
    << std::endl;
  std::cout << "******************************  Click on the 4 dots  "
    "*******************************"
    << std::endl;
  std::cout << "********Dot1 : (-x,-y,0), Dot2 : (x,-y,0), Dot3 : (x,y,0), "
    "Dot4 : (-x,y,0)**********"
    << std::endl;
  std::cout << "*************************************************************"
    "***********************"
    << std::endl;
 
  try {
    vpImagePoint ip[4];
    if (!opt_click_allowed) {
      ip[0].set_i(265);
      ip[0].set_j(93);
      ip[1].set_i(248);
      ip[1].set_j(242);
      ip[2].set_i(166);
      ip[2].set_j(215);
      ip[3].set_i(178);
      ip[3].set_j(85);
    }
    for (unsigned int i = 0; i < 4; i++) {
      // by using setGraphics, we request to see the edges of the dot
      // in red on the screen.
      // It uses the overlay image plane.
      // The default of this setting is that it is time consuming
 
      md[i].setGraphics(true);
      md[i].setGrayLevelPrecision(0.7);
      md[i].setSizePrecision(0.5);
 
      for (unsigned int j = 0; j < i; j++)
        md[j].display(I);
 
      // flush the display buffer
      vpDisplay::flush(I);
      try {
        if (opt_click_allowed)
          md[i].initTracking(I);
        else
          md[i].initTracking(I, ip[i]);
      }
      catch (...) {
      }
 
      mcog[i] = md[i].getCog();
      // an exception is thrown by the track method if
      //  - dot is lost
      //  - the number of pixel is too small
      //  - too many pixels are detected (this is usual when a "big"
      //  specularity
      //    occurs. The threshold can be modified using the
      //    setNbMaxPoint(int) method
      if (opt_display) {
        md[i].display(I);
        // flush the display buffer
        vpDisplay::flush(I);
      }
    }
  }
  catch (const vpException &e) {
    vpERROR_TRACE("Error while tracking dots");
    vpCTRACE << e;
    return;
  }
 
  if (opt_display) {
    // display a red cross (size 10) in the image at the dot center
    // of gravity location
    //
    // WARNING
    // in the vpDisplay class member's when pixel coordinates
    // are considered the first element is the row index and the second
    // is the column index:
    //   vpDisplay::displayCross(Image, row index, column index, size, color)
    //   therefore u and v are inverted wrt to the vpDot specification
    // Alternatively, to avoid this problem another set of member have
    // been defined in the vpDisplay class.
    // If the method name is postfixe with _uv the specification is :
    //   vpDisplay::displayCross_uv(Image, column index, row index, size,
    //   color)
 
    for (unsigned int i = 0; i < 4; i++)
      vpDisplay::displayCross(I, mcog[i], 10, vpColor::red);
 
    // flush the X11 buffer
    vpDisplay::flush(I);
  }
 
  // --------------------------------------------------------
  //             Now we will compute the pose
  // --------------------------------------------------------
 
  //  the list of point is cleared (if that's not done before)
  mPose->clearPoint();
 
  // we set the 3D points coordinates (in meter !) in the object/world frame
  double l = 0.06;
  double L = 0.07;
  mP[0].setWorldCoordinates(-L, -l, 0); // (X,Y,Z)
  mP[1].setWorldCoordinates(L, -l, 0);
  mP[2].setWorldCoordinates(L, l, 0);
  mP[3].setWorldCoordinates(-L, l, 0);
 
  // pixel-> meter conversion
  for (unsigned int i = 0; i < 4; i++) {
    // u[i]. v[i] are expressed in pixel
    // conversion in meter is achieved using
    // x = (u-u0)/px
    // y = (v-v0)/py
    // where px, py, u0, v0 are the intrinsic camera parameters
    double x = 0, y = 0;
    vpPixelMeterConversion::convertPoint(*mcam, mcog[i], x, y);
    mP[i].set_x(x);
    mP[i].set_y(y);
  }
 
  // The pose structure is build, we put in the point list the set of point
  // here both 2D and 3D world coordinates are known
  for (unsigned int i = 0; i < 4; i++) {
    mPose->addPoint(mP[i]); // and added to the pose computation point list
  }
 
  // compute the initial pose using Dementhon method followed by a non linear
  // minimization method
 
  // Compute initial pose
  mPose->computePose(vpPose::DEMENTHON_LAGRANGE_VIRTUAL_VS, *cMo);
 
  // Display briefly just to have a glimpse a the ViSP pose
  if (opt_display) {
    // Display the computed pose
    mPose->display(I, *cMo, *mcam, 0.05, vpColor::red);
    vpDisplay::flush(I);
    vpTime::wait(800);
  }
}
 
#endif
 
int main(int argc, const char **argv)
{
#if VISP_HAVE_DATASET_VERSION >= 0x030600
  std::string ext("png");
#else
  std::string ext("pgm");
#endif
  try {
    std::string env_ipath;
    std::string opt_ipath;
    std::string ipath;
    std::string opt_ppath;
    std::string dirname;
    std::string filename;
    bool opt_click_allowed = true;
 
    // Get the visp-images-data package path or VISP_INPUT_IMAGE_PATH
    // environment variable value
    env_ipath = vpIoTools::getViSPImagesDataPath();
 
    // Set the default input path
    if (!env_ipath.empty())
      ipath = env_ipath;
 
    // Read the command line options
    if (getOptions(argc, argv, opt_ipath, opt_ppath, opt_click_allowed) == false) {
      return EXIT_FAILURE;
    }
 
    // Get the option values
    if (!opt_ipath.empty())
      ipath = opt_ipath;
 
    // Compare ipath and env_ipath. If they differ, we take into account
    // the input path coming from the command line option
    if (!opt_ipath.empty() && !env_ipath.empty() && opt_ppath.empty()) {
      if (ipath != env_ipath) {
        std::cout << std::endl << "WARNING: " << std::endl;
        std::cout << "  Since -i <visp image path=" << ipath << "> "
          << "  is different from VISP_IMAGE_PATH=" << env_ipath << std::endl
          << "  we skip the environment variable." << std::endl;
      }
    }
 
    // Test if an input path is set
    if (opt_ipath.empty() && env_ipath.empty() && opt_ppath.empty()) {
      usage(argv[0], nullptr, ipath, opt_ppath);
      std::cerr << std::endl << "ERROR:" << std::endl;
      std::cerr << "  Use -i <visp image path> option or set VISP_INPUT_IMAGE_PATH " << std::endl
        << "  environment variable to specify the location of the " << std::endl
        << "  image path where test images are located." << std::endl
        << "  Use -p <personal image path> option if you want to " << std::endl
        << "  use personal images." << std::endl
        << std::endl;
 
      return EXIT_FAILURE;
    }
 
    std::ostringstream s;
 
    if (opt_ppath.empty()) {
      // Set the path location of the image sequence
      dirname = vpIoTools::createFilePath(ipath, "mire-2");
 
      // Build the name of the image file
 
      s.setf(std::ios::right, std::ios::adjustfield);
      s << "image.%04d.";
      s << ext;
      filename = vpIoTools::createFilePath(dirname, s.str());
    }
    else {
      filename = opt_ppath;
    }
 
    // We will read a sequence of images
    vpVideoReader grabber;
    grabber.setFirstFrameIndex(1);
    grabber.setFileName(filename.c_str());
    // Grey level image associated to a display in the initial pose
    // computation
    vpImage<unsigned char> Idisplay;
    // Grey level image to track points
    vpImage<unsigned char> I;
    // RGBa image to get background
    vpImage<vpRGBa> IC;
    // Matrix representing camera parameters
    vpHomogeneousMatrix cMo;
 
    // Variables used for pose computation purposes
    vpPose mPose;
    vpDot2 md[4];
    vpImagePoint mcog[4];
    vpPoint mP[4];
 
    // CameraParameters we got from calibration
    // Keep u0 and v0 as center of the screen
    vpCameraParameters mcam;
 
    try {
      vpCTRACE << "Load: " << filename << std::endl;
      grabber.open(Idisplay);
      grabber.acquire(Idisplay);
      vpCameraParameters mcamTmp(592, 570, grabber.getWidth() / 2, grabber.getHeight() / 2);
      // Compute the initial pose of the camera
      computeInitialPose(&mcamTmp, Idisplay, &mPose, md, mcog, &cMo, mP, opt_click_allowed);
      // Close the framegrabber
      grabber.close();
 
      // Associate the grabber to the RGBa image
      grabber.open(IC);
      mcam.init(mcamTmp);
    }
    catch (...) {
      std::cerr << std::endl << "ERROR:" << std::endl;
      std::cerr << "  Cannot read " << filename << std::endl;
      std::cerr << "  Check your -i " << ipath << " option " << std::endl
        << "  or VISP_INPUT_IMAGE_PATH environment variable." << std::endl;
      return EXIT_FAILURE;
    }
 
    // Create a vpRAOgre object with color background
    vpAROgreExample ogre(mcam, (unsigned int)grabber.getWidth(), (unsigned int)grabber.getHeight());
    // Initialize it
    ogre.init(IC);
 
    double t0 = vpTime::measureTimeMs();
 
    // Rendering loop
    while (ogre.continueRendering() && !grabber.end()) {
      // Acquire a frame
      grabber.acquire(IC);
 
      // Convert it to a grey level image for tracking purpose
      vpImageConvert::convert(IC, I);
 
      // kill the point list
      mPose.clearPoint();
 
      // track the dot
      for (int i = 0; i < 4; i++) {
        // track the point
        md[i].track(I, mcog[i]);
        md[i].setGrayLevelPrecision(0.90);
        // pixel->meter conversion
        {
          double x = 0, y = 0;
          vpPixelMeterConversion::convertPoint(mcam, mcog[i], x, y);
          mP[i].set_x(x);
          mP[i].set_y(y);
        }
 
        // and added to the pose computation point list
        mPose.addPoint(mP[i]);
      }
      // the pose structure has been updated
 
      // the pose is now updated using the virtual visual servoing approach
      // Dementhon or lagrange is no longer necessary, pose at the
      // previous iteration is sufficient
      mPose.computePose(vpPose::VIRTUAL_VS, cMo);
 
      // Display with ogre
      ogre.display(IC, cMo);
 
      // Wait so that the video does not go too fast
      double t1 = vpTime::measureTimeMs();
      std::cout << "\r> " << 1000 / (t1 - t0) << " fps";
      t0 = t1;
    }
    // Close the grabber
    grabber.close();
 
    return EXIT_SUCCESS;
  }
  catch (const vpException &e) {
    std::cout << "Catch a ViSP exception: " << e << std::endl;
    return EXIT_FAILURE;
  }
  catch (Ogre::Exception &e) {
    std::cout << "Catch an Ogre exception: " << e.getDescription() << std::endl;
    return EXIT_FAILURE;
  }
  catch (...) {
    std::cout << "Catch an exception " << std::endl;
    return EXIT_FAILURE;
  }
}
#else // VISP_HAVE_OGRE && VISP_HAVE_DISPLAY
int main()
{
#if (!(defined(VISP_HAVE_X11) || defined(VISP_HAVE_GTK) || defined(VISP_HAVE_GDI)))
  std::cout << "You do not have X11, or GTK, or GDI (Graphical Device Interface) functionalities to display images..."
    << std::endl;
  std::cout << "Tip if you are on a unix-like system:" << std::endl;
  std::cout << "- Install X11, configure again ViSP using cmake and build again this example" << std::endl;
  std::cout << "Tip if you are on a windows-like system:" << std::endl;
  std::cout << "- Install GDI, configure again ViSP using cmake and build again this example" << std::endl;
#else
  std::cout << "You do not have Ogre functionalities" << std::endl;
  std::cout << "Tip:" << std::endl;
  std::cout << "- Install Ogre3D, configure again ViSP using cmake and build again this example" << std::endl;
#endif
  return EXIT_SUCCESS;
  }
#endif