//
// ZoneMinder Polygon Class Interfaces, $Date$, $Revision$
// Copyright (C) 2001-2008 Philip Coombes
// 
// 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
// 

#ifndef ZM_POLY_H
#define ZM_POLY_H

#include "zm.h"
#include "zm_coord.h"
#include "zm_box.h"

#include <math.h>

//
// Class used for storing a box, which is defined as a region
// defined by two coordinates
//
class Polygon
{
protected:
  struct Edge
  {
    int min_y;
    int max_y;
    double min_x;
    double _1_m;

    static int CompareYX( const void *p1, const void *p2 )
    {
      const Edge *e1 = (const Edge *)p1, *e2 = (const Edge *)p2;
      if ( e1->min_y == e2->min_y )
        return( int(e1->min_x - e2->min_x) );
      else
        return( int(e1->min_y - e2->min_y) );
    }
    static int CompareX( const void *p1, const void *p2 )
    {
      const Edge *e1 = (const Edge *)p1, *e2 = (const Edge *)p2;
      return( int(e1->min_x - e2->min_x) );
    }
  };

  struct Slice
  {
    int min_x;
    int max_x;
    int n_edges;
    int *edges;

    Slice()
    {
      n_edges = 0;
      edges = 0;
    }
    ~Slice()
    {
      delete edges;
    }
  };

protected:
  int n_coords;
  Coord *coords;
  Box extent;
  int area;
  Coord centre;
  Edge *edges;
  Slice *slices;

protected:
  void initialiseEdges();
  void calcArea();
  void calcCentre();

public:
  inline Polygon() : n_coords( 0 ), coords( 0 ), area( 0 )
  {
  }
  Polygon( int p_n_coords, const Coord *p_coords );
  Polygon( const Polygon &p_polygon );
  ~Polygon()
  {
    delete[] coords;
  }

  Polygon &operator=( const Polygon &p_polygon );

  inline int getNumCoords() const { return( n_coords ); }
  inline const Coord &getCoord( int index ) const
  {
    return( coords[index] );
  }

  inline const Box &Extent() const { return( extent ); }
  inline int LoX() const { return( extent.LoX() ); }
  inline int HiX() const { return( extent.HiX() ); }
  inline int LoY() const { return( extent.LoY() ); }
  inline int HiY() const { return( extent.HiY() ); }
  inline int Width() const { return( extent.Width() ); }
  inline int Height() const { return( extent.Height() ); }

  inline int Area() const { return( area ); }
  inline const Coord &Centre() const
  {
    return( centre );
  }
  bool isInside( const Coord &coord ) const;
};

#endif // ZM_POLY_H
