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constraint.h

//$Header: /home/ben/Mapper/include/RCS/constraint.h,v 6.4 2002/06/10 22:16:16 ben Exp $
#ifndef CONSTRAINT_H
#define CONSTRAINT_H
// Copyright Benedict Adamson 2002.
// This file is part of Mapper.

// Mapper 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.

// Mapper is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Mapper; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

#include <vector>

#include "vector2.h"



class constraint
{
   public: //Constructors and destructors.
      constraint(
         const double u
         );

      virtual ~constraint(void);

   public: //Attributes

      double energy(
         const double tol
         ) const;



      virtual void energy(
         const double tol,
         const vector< vector2 > &p,
         double &e, //output
         vector< vector2 > &dedp //output
         ) const = 0;

      inline double uncertainty(void) const;
      
   public: //Relationships

      inline vector< vector2 * > &points(void);

      inline const vector< vector2 * > &points(void) const;

   public: //Messages

      void uncertainty(
         const double u
         );

   private: //State

      double uncertainty_;

   protected: //State
      vector< vector2 * > points_;

};



inline double constraint::uncertainty(void) const
{
   //A measure of how loose the constraint is.
   return this->uncertainty_;
}


      
inline vector< vector2 * > &constraint::points(void)
{
   //The points whose position the constraint directly applies to.
   //Moving these points can change the energy of the constraint;
   //Moving anyother points never changes the ernegy of the constraint.
   return this->points_;
}



inline const vector< vector2 * > &constraint::points(void) const
{
   //The points whose position the constraint directly applies to.
   //Moving these points can change the energy of the constraint;
   //Moving anyother points never changes the ernegy of the constraint.
   return this->points_;
}



#endif

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