coord_system.C

/*
 * This file is part of the "Archon" framework.
 * (http://files3d.sourceforge.net)
 *
 * Copyright © 2002 by Kristian Spangsege and Brian Kristiansen.
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation under the terms of the GNU General Public License is
 * hereby granted. No representations are made about the suitability of
 * this software for any purpose. It is provided "as is" without express
 * or implied warranty. See the GNU General Public License
 * (http://www.gnu.org/copyleft/gpl.html) for more details.
 *
 * The characters in this file are ISO8859-1 encoded.
 *
 * The documentation in this file is in "Doxygen" style
 * (http://www.doxygen.org).
 */

#include <archon/math/coord_system.H>

using namespace std;

namespace Archon
{
  namespace Math
  {
    CoordSystem3x3 CoordSystem3x3::makeIdentity()
    {
      return CoordSystem3x3(Vector3::zero(), Matrix3x3::identity());
    }

    const CoordSystem3x3 &CoordSystem3x3::identity()
    {
      static CoordSystem3x3 v = makeIdentity();
      return v;
    }

    CoordSystem3x3::CoordSystem3x3(const double m[])
    {
      basis.x[0] = m[0];
      basis.x[1] = m[1]; 
      basis.x[2] = m[2]; 
      basis.y[0] = m[4]; 
      basis.y[1] = m[5]; 
      basis.y[2] = m[6]; 
      basis.z[0] = m[8]; 
      basis.z[1] = m[9]; 
      basis.z[2] = m[10]; 
      origin[0]  = m[12]; 
      origin[1]  = m[13]; 
      origin[2]  = m[14]; 
    }

    void CoordSystem3x3::setOpenGLMatrix(double m[])
    {
      m[0]  = basis.x[0];
      m[1]  = basis.x[1];
      m[2]  = basis.x[2];
      m[4]  = basis.y[0];
      m[5]  = basis.y[1];
      m[6]  = basis.y[2];
      m[8]  = basis.z[0];
      m[9]  = basis.z[1];
      m[10] = basis.z[2];
      m[12] = origin[0];
      m[13] = origin[1];
      m[14] = origin[2];
      m[3]  = m[7] = m[11] = 0;
      m[15] = 1;    
    }

    void CoordSystem3x3::minimalTurn(const Vector3 &point)
    {
      double p, angle;
      Vector3 v = point;
      v -= origin;
      v.normalize();
      p = dot(v, basis.z);
      if(p == -1) return; // Parallel same direction as negative z-axis
      if(p ==  1)         // Parallel opposite direction as negative z-axis
      {
        v = basis.y;
        angle = M_PI;
      }
      else
      {
        v *= basis.z;
        v.normalize();
        angle = acos(-p);
      }
      basis.rotateRightHandedOrthoNormal(Rotation3(v, angle));
    }

    std::ostream &operator<<(std::ostream &out, const CoordSystem3x3 &s)
    {
      out << "Origin: " << s.origin <<  "\n";
      out << "Basis:\n";
      out << s.basis;
      return out;
    }
  }
}

---