vpLine.cpp

/****************************************************************************
 *
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2019 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 http://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:
 * Line feature.
 *
 * Authors:
 * Eric Marchand
 *
 *****************************************************************************/

#include <visp3/core/vpLine.h>

#include <visp3/core/vpDebug.h>
#include <visp3/core/vpMath.h>

#include <visp3/core/vpFeatureDisplay.h>

void vpLine::init()
{
  oP.resize(8);
  cP.resize(8);
  p.resize(2);
}

vpLine::vpLine() { init(); }

void vpLine::setWorldCoordinates(const double &A1, const double &B1, const double &C1, const double &D1,
                                 const double &A2, const double &B2, const double &C2, const double &D2)
{
  oP[0] = A1;
  oP[1] = B1;
  oP[2] = C1;
  oP[3] = D1;

  oP[4] = A2;
  oP[5] = B2;
  oP[6] = C2;
  oP[7] = D2;
}

void vpLine::setWorldCoordinates(const vpColVector &oP_)
{
  if (oP_.getRows() != 8)
    throw vpException(vpException::dimensionError, "Size of oP is not equal to 8 as it should be");

  this->oP = oP_;
}

void vpLine::setWorldCoordinates(const vpColVector &oP1, const vpColVector &oP2)
{
  if (oP1.getRows() != 4)
    throw vpException(vpException::dimensionError, "Size of oP1 is not equal to 4 as it should be");

  if (oP2.getRows() != 4)
    throw vpException(vpException::dimensionError, "Size of oP2 is not equal to 4 as it should be");

  for (unsigned int i = 0; i < 4; i++) {
    oP[i] = oP1[i];
    oP[i + 4] = oP2[i];
  }
}

void vpLine::projection()
{
  projection(cP, p);
}

void vpLine::projection(const vpColVector &cP_, vpColVector &p_)
{
  // projection

  if (cP.getRows() != 8)
    throw vpException(vpException::dimensionError, "Size of cP is not equal to 8 as it should be");

  double A1, A2, B1, B2, C1, C2, D1, D2;

  A1 = cP_[0];
  B1 = cP_[1];
  C1 = cP_[2];
  D1 = cP_[3];

  A2 = cP_[4];
  B2 = cP_[5];
  C2 = cP_[6];
  D2 = cP_[7];

  double a, b, c, s;
  a = A2 * D1 - A1 * D2;
  b = B2 * D1 - B1 * D2;
  c = C2 * D1 - C1 * D2;
  s = a * a + b * b;
  if (s <= 1e-8) // seuil pas terrible
  {
    printf("Degenerate case: the image of the straight line is a point!\n");
    throw vpException(vpException::fatalError, "Degenerate case: the image of the straight line is a point!");
  }
  s = 1.0 / sqrt(s);

  double rho = -c * s;
  double theta = atan2(b, a);

  if (p.getRows() != 2)
    p.resize(2);

  p_[0] = rho;
  p_[1] = theta;
}

void vpLine::changeFrame(const vpHomogeneousMatrix &cMo) { changeFrame(cMo, cP); }

void vpLine::changeFrame(const vpHomogeneousMatrix &cMo, vpColVector &cP_)
{

  double a1, a2, b1, b2, c1, c2, d1, d2;
  double A1, A2, B1, B2, C1, C2, D1, D2;

  // in case of verification
  // double x,y,z,ap1,ap2,bp1,bp2,cp1,cp2,dp1,dp2;

  if (cP.getRows() != 8)
    cP.resize(8);

  a1 = oP[0];
  b1 = oP[1];
  c1 = oP[2];
  d1 = oP[3];

  a2 = oP[4];
  b2 = oP[5];
  c2 = oP[6];
  d2 = oP[7];

  A1 = cMo[0][0] * a1 + cMo[0][1] * b1 + cMo[0][2] * c1;
  B1 = cMo[1][0] * a1 + cMo[1][1] * b1 + cMo[1][2] * c1;
  C1 = cMo[2][0] * a1 + cMo[2][1] * b1 + cMo[2][2] * c1;
  D1 = d1 - (cMo[0][3] * A1 + cMo[1][3] * B1 + cMo[2][3] * C1);

  A2 = cMo[0][0] * a2 + cMo[0][1] * b2 + cMo[0][2] * c2;
  B2 = cMo[1][0] * a2 + cMo[1][1] * b2 + cMo[1][2] * c2;
  C2 = cMo[2][0] * a2 + cMo[2][1] * b2 + cMo[2][2] * c2;
  D2 = d2 - (cMo[0][3] * A2 + cMo[1][3] * B2 + cMo[2][3] * C2);

  // in case of verification
  // ap1 = A1; bp1 = B1; cp1 = C1; dp1 = D1;
  // ap2 = A2; bp2 = B2; cp2 = C2; dp2 = D2;

  //  vpERROR_TRACE("A1 B1 C1 D1 %f %f %f %f  ", A1, B1, C1, D1) ;
  //  vpERROR_TRACE("A2 B2 C2 D2 %f %f %f %f  ", A2, B2, C2, D2) ;

  // Adding constraints on the straight line to have a unique representation

  // direction of the straight line = N1 x N2
  a2 = B1 * C2 - C1 * B2;
  b2 = C1 * A2 - A1 * C2;
  c2 = A1 * B2 - B1 * A2;

  // Constraint D1 = 0 (the origin belongs to P1)
  a1 = A2 * D1 - A1 * D2;
  b1 = B2 * D1 - B1 * D2;
  c1 = C2 * D1 - C1 * D2;

  if (fabs(D2) < fabs(D1)) // to be sure that D2 <> 0
  {
    A2 = A1;
    B2 = B1;
    C2 = C1;
    D2 = D1;
  }

  // Constraint A1^2 + B1^2 + C1^2 = 1
  d1 = 1.0 / sqrt(a1 * a1 + b1 * b1 + c1 * c1);
  cP_[0] = A1 = a1 * d1;
  cP_[1] = B1 = b1 * d1;
  cP_[2] = C1 = c1 * d1;
  cP_[3] = 0;

  // Constraint A1 A2 + B1 B2 + C1 C2 = 0 (P2 orthogonal to P1)
  // N2_new = (N1 x N2) x N1_new
  a1 = b2 * C1 - c2 * B1;
  b1 = c2 * A1 - a2 * C1;
  c1 = a2 * B1 - b2 * A1;

  // Constraint A2^2 + B2^2 + C2^2 = 1
  d1 = 1.0 / sqrt(a1 * a1 + b1 * b1 + c1 * c1);
  a1 *= d1;
  b1 *= d1;
  c1 *= d1;

  // D2_new = D2 / (N2^T . N2_new)
  D2 /= (A2 * a1 + B2 * b1 + C2 * c1);
  A2 = a1;
  B2 = b1;
  C2 = c1;

  // Constraint D2 < 0
  if (D2 > 0) {
    A2 = -A2;
    B2 = -B2;
    C2 = -C2;
    D2 = -D2;
  }
  //  vpERROR_TRACE("A1 B1 C1 D1 %f %f %f %f  ", A1, B1, C1, D1) ;
  //  vpERROR_TRACE("A2 B2 C2 D2 %f %f %f %f  ", A2, B2, C2, D2) ;

  cP_[4] = A2;
  cP_[5] = B2;
  cP_[6] = C2;
  cP_[7] = D2;

  // in case of verification
  /*
  x = -A2*D2;
  y = -B2*D2;
  z = -C2*D2;
  d1 = ap1*x+bp1*y+cp1*z+dp1;
  d2 = ap2*x+bp2*y+cp2*z+dp2;
  if ((fabs(d1) > 1e-8) || (fabs(d2) > 1e-8))
    {
      printf("PB in VPline: P1 : 0 = %lf, P2: 0 = %lf\n",d1,d2);
      exit(-1);
    }
  d1 = A1*x+B1*y+C1*z+D1;
  d2 = A2*x+B2*y+C2*z+D2;
  if ((fabs(d1) > 1e-8) || (fabs(d2) > 1e-8))
    {
      printf("PB in VPline: Pn1 : 0 = %lf, Pn2: 0 = %lf\n",d1,d2);
      exit(-1);
    }
  */
}

void vpLine::display(const vpImage<unsigned char> &I, const vpCameraParameters &cam, const vpColor &color,
                     unsigned int thickness)
{
  vpFeatureDisplay::displayLine(p[0], p[1], cam, I, color, thickness);
}

// non destructive wrt. cP and p
void vpLine::display(const vpImage<unsigned char> &I, const vpHomogeneousMatrix &cMo, const vpCameraParameters &cam,
                     const vpColor &color, unsigned int thickness)
{
  vpColVector _cP, _p;
  changeFrame(cMo, _cP);
  try {
    projection(_cP, _p);
    vpFeatureDisplay::displayLine(_p[0], _p[1], cam, I, color, thickness);
  }
  catch(...) {
    // Skip potential exception: due to a degenerate case: the image of the straight line is a point!
  }
}

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