/* Copyright_License {

  XCSoar Glide Computer - http://www.xcsoar.org/
  Copyright (C) 2000-2015 The XCSoar Project
  A detailed list of copyright holders can be found in the file "AUTHORS".

  This program 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.

  This program 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 this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
}
 */

#ifndef AATISOLINESEGMENT_HPP
#define AATISOLINESEGMENT_HPP

#include "AATIsoline.hpp"

/**
 *  Specialisation of AATIsoline such that the segment of
 *  the isoline within the task point's observation zone is
 *  determined.  This allows for parametric representation
 *  of all points along the isoline within the OZ.
 * 
 *  End-points of segments are searched for and so this
 *  class is slow to instantiate.
 */
class AATIsolineSegment: public AATIsoline
{
  fixed t_up;
  fixed t_down;

public:
  /**
   * Constructor.  This performs the search for the isoline
   * segment and so is slow.
   *
   * @param ap The AAT point for which the isoline is sought
   *
   * @return Initialised object
   */
  AATIsolineSegment(const AATPoint &ap, const FlatProjection &projection);

  /**
   * Test whether segment is valid (nonzero length)
   *
   * @return True if segment is valid
   */
  bool IsValid() const;

  /**
   * Parametric representation of points on the isoline segment.
   *
   * @param t Parameter (0,1)
   *
   * @return Location of point on isoline segment
   */
  GeoPoint Parametric(const fixed t) const;
};

#endif
