Astar.cc

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/*
 *  Copyright (C) 2000-2001  The Exult Team
 *
 *  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.
 */

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif


#include "Astar.h"

/*
 *  Find path from source to destination.
 *
 *  Output: 1 if successful, else 0.
 */
int Astar::NewPath(Tile_coord s, Tile_coord d, Pathfinder_client *client)
{
  extern Tile_coord *Find_path(Tile_coord, Tile_coord,
          Pathfinder_client *client, int& plen);
  src = s;      // Store start, destination.
  dest = d;
  path.clear();   // Clear out old path, if there.
  Tile_coord *t = Find_path(s, d, client, pathlen);
  bool success = (t != 0);
  for(int i=0;i<pathlen;i++)
    path.push_back(t[i]);
  delete [] t;  // Discard temporary storage
  next_index = 0;
  dir = 1;
  stop = pathlen;
  return (success);
}

/*
 *  Get next point on path to go to (in tile coords).
 *
 *  Output: 0 if all done.
 */
int Astar::GetNextStep(Tile_coord& n, bool& done)
{
  if (next_index == stop)
    {
    done = true;
    return (0);
    }
  n = path[next_index];
  next_index += dir;
  done = (next_index == stop);
  return 1;
}

/*
 *  Set to traverse backwards.
 *
 *  Output: 1 always (we succeeded).
 */
int Astar::set_backwards
  (
  )
  {
  dir = -1;
  stop = -1;
  next_index = pathlen - 1;
  return 1;
  }

/*
 *  Get # steps left.
 */
int Astar::get_num_steps
  (
  )
  {
  return (stop - next_index)*dir;
  }

/*
 *  Delete.
 */
Astar::~Astar
  (
  )
  {
  }

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