vpFeaturePoint.cpp

/*
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2025 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:
 * 2D point visual feature.
 */

 
#include <visp3/visual_features/vpBasicFeature.h>
#include <visp3/visual_features/vpFeaturePoint.h>
 
// Exception
#include <visp3/core/vpException.h>
#include <visp3/visual_features/vpFeatureException.h>
 
// Debug trace
#include <visp3/core/vpDebug.h>
 
// math
#include <visp3/core/vpMath.h>
 
#include <visp3/core/vpFeatureDisplay.h>
 
/*
 
attributes and members directly related to the vpBasicFeature needs
other functionalities ar useful but not mandatory
 
*/
 
BEGIN_VISP_NAMESPACE
void vpFeaturePoint::init()
{
  // feature dimension
  dim_s = 2;
  nbParameters = 3;
 
  // memory allocation
  s.resize(dim_s);
  if (flags == nullptr)
    flags = new bool[nbParameters];
  for (unsigned int i = 0; i < nbParameters; i++)
    flags[i] = false;
 
  // default value Z (1 meters)
  Z = 1;
}

vpFeaturePoint::vpFeaturePoint() : Z(1.) { init(); }

void vpFeaturePoint::set_Z(double Z_)
{
  this->Z = Z_;
  flags[2] = true;
}

double vpFeaturePoint::get_Z() const { return Z; }

void vpFeaturePoint::set_x(double x)
{
  s[0] = x;
  flags[0] = true;
}

double vpFeaturePoint::get_x() const { return s[0]; }

void vpFeaturePoint::set_y(double y)
{
  s[1] = y;
  flags[1] = true;
}

double vpFeaturePoint::get_y() const { return s[1]; }

void vpFeaturePoint::set_xyZ(double x_, double y_, double Z_)
{
  set_x(x_);
  set_y(y_);
  set_Z(Z_);
  for (unsigned int i = 0; i < nbParameters; i++)
    flags[i] = true;
}

vpMatrix vpFeaturePoint::interaction(unsigned int select)
{
  vpMatrix L;
 
  L.resize(0, 6);
 
  if (deallocate == vpBasicFeature::user) {
    for (unsigned int i = 0; i < nbParameters; i++) {
      if (flags[i] == false) {
        switch (i) {
        case 0:
          vpTRACE("Warning !!!  The interaction matrix is computed but x was "
                  "not set yet");
          break;
        case 1:
          vpTRACE("Warning !!!  The interaction matrix is computed but y was "
                  "not set yet");
          break;
        case 2:
          vpTRACE("Warning !!!  The interaction matrix is computed but Z was "
                  "not set yet");
          break;
        default:
          vpTRACE("Problem during the reading of the variable flags");
        }
      }
    }
    resetFlags();
  }
 
  double x_ = get_x();
  double y_ = get_y();
  double Z_ = get_Z();
 
  if (Z_ < 0) {
    vpERROR_TRACE("Point is behind the camera ");
    std::cout << "Z = " << Z_ << std::endl;
 
    throw(vpFeatureException(vpFeatureException::badInitializationError, "Point is behind the camera "));
  }
 
  if (fabs(Z_) < 1e-6) {
    vpERROR_TRACE("Point Z coordinates is null ");
    std::cout << "Z = " << Z_ << std::endl;
 
    throw(vpFeatureException(vpFeatureException::badInitializationError, "Point Z coordinates is null"));
  }
 
  if (vpFeaturePoint::selectX() & select) {
    vpMatrix Lx(1, 6);
    Lx = 0;
 
    Lx[0][0] = -1 / Z_;
    Lx[0][1] = 0;
    Lx[0][2] = x_ / Z_;
    Lx[0][3] = x_ * y_;
    Lx[0][4] = -(1 + x_ * x_);
    Lx[0][5] = y_;
 
    L = vpMatrix::stack(L, Lx);
  }
 
  if (vpFeaturePoint::selectY() & select) {
    vpMatrix Ly(1, 6);
    Ly = 0;
 
    Ly[0][0] = 0;
    Ly[0][1] = -1 / Z_;
    Ly[0][2] = y_ / Z_;
    Ly[0][3] = 1 + y_ * y_;
    Ly[0][4] = -x_ * y_;
    Ly[0][5] = -x_;
 
    L = vpMatrix::stack(L, Ly);
  }
  return L;
}

vpColVector vpFeaturePoint::error(const vpBasicFeature &s_star, unsigned int select)
{
  vpColVector e(0);
 
  try {
    if (vpFeaturePoint::selectX() & select) {
      vpColVector ex(1);
      ex[0] = s[0] - s_star[0];
 
      e = vpColVector::stack(e, ex);
    }
 
    if (vpFeaturePoint::selectY() & select) {
      vpColVector ey(1);
      ey[0] = s[1] - s_star[1];
      e = vpColVector::stack(e, ey);
    }
  }
  catch (...) {
    throw;
  }
 
  return e;
}

void vpFeaturePoint::print(unsigned int select) const
{
 
  std::cout << "Point:  Z=" << get_Z();
  if (vpFeaturePoint::selectX() & select)
    std::cout << " x=" << get_x();
  if (vpFeaturePoint::selectY() & select)
    std::cout << " y=" << get_y();
  std::cout << std::endl;
}

vpFeaturePoint &vpFeaturePoint::buildFrom(const double &x_, const double &y_, const double &Z_)
{
 
  s[0] = x_;
  s[1] = y_;
 
  this->Z = Z_;
 
  if (Z_ < 0) {
    vpERROR_TRACE("Point is behind the camera ");
    std::cout << "Z = " << Z_ << std::endl;
 
    throw(vpFeatureException(vpFeatureException::badInitializationError, "Point is behind the camera "));
  }
 
  if (fabs(Z_) < 1e-6) {
    vpERROR_TRACE("Point Z coordinates is null ");
    std::cout << "Z = " << Z_ << std::endl;
 
    throw(vpFeatureException(vpFeatureException::badInitializationError, "Point Z coordinates is null"));
  }
 
  for (unsigned int i = 0; i < nbParameters; ++i) {
    flags[i] = true;
  }
  return *this;
}

void vpFeaturePoint::display(const vpCameraParameters &cam, const vpImage<unsigned char> &I, const vpColor &color,
                             unsigned int thickness) const
{
  try {
    double x, y;
    x = get_x();
    y = get_y();
 
    vpFeatureDisplay::displayPoint(x, y, cam, I, color, thickness);
 
  }
  catch (...) {
    vpERROR_TRACE("Error caught");
    throw;
  }
}

void vpFeaturePoint::display(const vpCameraParameters &cam, const vpImage<vpRGBa> &I, const vpColor &color,
                             unsigned int thickness) const
{
  try {
    double x, y;
    x = get_x();
    y = get_y();
 
    vpFeatureDisplay::displayPoint(x, y, cam, I, color, thickness);
 
  }
  catch (...) {
    vpERROR_TRACE("Error caught");
    throw;
  }
}

vpFeaturePoint *vpFeaturePoint::duplicate() const
{
  vpFeaturePoint *feature = new vpFeaturePoint;
  return feature;
}

unsigned int vpFeaturePoint::selectX() { return FEATURE_LINE[0]; }

unsigned int vpFeaturePoint::selectY() { return FEATURE_LINE[1]; }
END_VISP_NAMESPACE