text: //==============================================================================
  /*
      Software License Agreement (BSD License)
      Copyright (c) 2003-2016, CHAI3D.
      (www.chai3d.org)
  
      All rights reserved.
  
      Redistribution and use in source and binary forms, with or without
      modification, are permitted provided that the following conditions
      are met:
  
      * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
  
      * Redistributions in binary form must reproduce the above
      copyright notice, this list of conditions and the following
      disclaimer in the documentation and/or other materials provided
      with the distribution.
  
      * Neither the name of CHAI3D nor the names of its contributors may
      be used to endorse or promote products derived from this software
      without specific prior written permission.
  
      THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
      FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
      COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
      INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
      BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
      LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
      CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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      ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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      \author    <http://www.chai3d.org>
      \author    Francois Conti
      \version   3.2.0 $Rev: 1869 $
  */
  //==============================================================================
  
  //------------------------------------------------------------------------------
  #ifndef CGenericForceAlgorithmH
  #define CGenericForceAlgorithmH
  //------------------------------------------------------------------------------
  #include "math/CVector3d.h"
  #include "world/CGenericObject.h"
  //------------------------------------------------------------------------------
  #include <vector>
  //------------------------------------------------------------------------------
  
  //------------------------------------------------------------------------------
  namespace chai3d {
  //------------------------------------------------------------------------------
  
  //------------------------------------------------------------------------------
  class cWorld;
  //------------------------------------------------------------------------------
  
  //==============================================================================
  /*!
      \file       CGenericForceAlgorithm.h
  
      \brief
      Implements a base class for force rendering algorithms.
  */
  //==============================================================================
  
  //==============================================================================
  /*!   
      \class      cGenericForceAlgorithm
      \ingroup    forces
      
      \brief
      This class implements a base class for modeling force rendering algorithms.
  
      \details
      cGenericForceAlgorithm is an abstract class for modeling algorithms that 
      compute single point interation forces.
  */
  //==============================================================================
  class cGenericForceAlgorithm
  {
      //--------------------------------------------------------------------------
      // CONSTRUCTOR & DESTRUCTOR:
      //--------------------------------------------------------------------------
  
  public:
  
      //! Constructor of cGenericForceAlgorithm.
      cGenericForceAlgorithm();
      
      //! Destructor of cGenericForceAlgorithm.
      virtual ~cGenericForceAlgorithm() {};
  
  
      //--------------------------------------------------------------------------
      // PUBLIC METHODS:
      //--------------------------------------------------------------------------
  
  public:
  
      //! This method returns a pointer to the world in which the force algorithm is operating.
      cWorld* getWorld() { return (m_world); }
  
      //! This method initializes the algorithm by passing the starting position of the haptic device.
      virtual void initialize(cWorld* a_world, const cVector3d& a_initialPos) {};
  
      //! This method computes the next force given the updated position of the haptic device.
      virtual cVector3d computeForces(const cVector3d& a_toolPos, const cVector3d& a_toolVel)
          { return (cVector3d(0.0, 0.0, 0.0)); }
  
      // This method enables or disables graphic rendering of the force rendering algorithm.
      void setShowEnabled(bool a_showEnabled) { m_showEnabled = a_showEnabled; }
  
      // This method returns __true__ if the graphic rendering mode is enabled, __false__ otherwise.
      bool getShowEnabled() { return (m_showEnabled); }
  
  
      //--------------------------------------------------------------------------
      // PROTECTED METHODS - GRAPHICS
      //--------------------------------------------------------------------------
  
  protected:
  
      //! This method renders the force algorithm graphically using OpenGL. (For debug purposes)
      virtual void render(cRenderOptions& a_options) {}
  
  
      //--------------------------------------------------------------------------
      // PROTECTED MEMBERS:
      //--------------------------------------------------------------------------
  
  protected:
  
      //! Pointer to the world in which the force algorithm operates.
      cWorld* m_world;
  
      //! If __true__ then the graphic display mode is enabled.
      bool m_showEnabled;
  };
  
  //------------------------------------------------------------------------------
  } // namespace chai3d
  //------------------------------------------------------------------------------
  
  //------------------------------------------------------------------------------
  #endif
  //------------------------------------------------------------------------------
  
  