//
//  Filename         : Polygon.h
//  Author(s)        : Stephane Grabli
//  Purpose          : Class to define a polygon
//  Date of creation : 30/07/2002
//
///////////////////////////////////////////////////////////////////////////////


//
//  Copyright (C) : Please refer to the COPYRIGHT file distributed 
//   with this source distribution. 
//
//  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  POLYGON_H
# define POLYGON_H

# include <vector>
# include "Geom.h"
# include "GeomUtils.h"

using namespace std;

namespace Geometry {

template <class Point>
class Polygon
{
 public:

  inline Polygon() {
    _id = 0;
    userdata = 0;
    userdata2 = 0;
  }

  inline Polygon(const vector<Point>& vertices) {
    _vertices = vertices;
    computeBBox();
    _id = 0;
    userdata = 0;
    userdata2 = 0;
  }

  inline Polygon(const Polygon<Point>& poly) {
    Point p;
    for(typename vector<Point>::const_iterator it = poly.getVertices().begin();
	it != poly.getVertices().end();
	it++) {
      p = *it;
      _vertices.push_back(p);
    }

    _id = poly.getId();
    poly.getBBox(_min, _max);
    userdata = 0;
    userdata2 = 0;
  }
  
  virtual ~Polygon() {}

  //
  // Accessors
  //
  /////////////////////////////////////////////////////////////////////////////

  inline const vector<Point>& getVertices() const {
    return _vertices;
  }

  inline void getBBox(Point& min, Point& max) const {
    min = _min;
    max = _max;
  }

  inline Point& getBBoxCenter()
  {
    Point result;
    result = (_min + _max) / 2;
    return result;
  }

  inline Point& getCenter() {
    Point result;
    for (typename vector<Point>::iterator it = _vertices.begin();
	 it != _vertices.end();
	 it++)
      result += *it;
    result /= _vertices.size();
    return result;
  }

  inline unsigned getId() const {
    return _id;
  }

  //
  // Modifiers
  //
  /////////////////////////////////////////////////////////////////////////////

  inline void setVertices(const vector<Point>& vertices) {
    _vertices.clear();
    Point p;
    for (typename vector<Point>::const_iterator it = vertices.begin();
	 it != vertices.end();
	 it++) {
      p = *it;
      _vertices.push_back(p);
    }
    computeBBox();
  }

  inline void setId(unsigned id) {
    _id = id;
  }

  //
  // Other methods
  //
  /////////////////////////////////////////////////////////////////////////////

  inline void computeBBox() {
    if(_vertices.empty())
      return;
    
    _max = _vertices[0];
    _min = _vertices[0];

    for(typename vector<Point>::iterator it = _vertices.begin();
	it != _vertices.end();
        it++) {
      for(unsigned i = 0; i < Point::dim(); i++) {
	if((*it)[i] > _max[i])
	  _max[i] = (*it)[i];
	if((*it)[i] < _min[i])
	  _min[i] = (*it)[i];
      }
    }
  }
  
  // FIXME Is it possible to get rid of userdatas ?
  void* userdata;
  void* userdata2; // Used during ray casting
  
 protected:
  
  vector<Point>	_vertices;
  Point		_min;
  Point		_max;
  unsigned	_id;
};


//
// Polygon3r class
//
///////////////////////////////////////////////////////////////////////////////

class Polygon3r : public Polygon<Vec3r>
{
 public:

  inline Polygon3r() : Polygon<Vec3r>() {}

  inline Polygon3r(const vector<Vec3r>& vertices,
		   const Vec3r& normal) : Polygon<Vec3r>(vertices) {
    setNormal(normal);
  }

  inline Polygon3r(const Polygon3r& poly) : Polygon<Vec3r>(poly) {}
  
  virtual ~Polygon3r() {}

  void setNormal(const Vec3r& normal) {
    _normal = normal;
  }

  Vec3r getNormal() const {
    return _normal;
  }

  /*! Check whether the Polygon intersects with the ray or not */
  inline bool rayIntersect(Vec3r& orig, Vec3r& dir,
			   real& t, real& u, real& v, real epsilon = M_EPSILON) {
    //    if (_vertices.size() < 3)
    //      return false;
    return GeomUtils::intersectRayTriangle(orig, dir,
					   _vertices[0], _vertices[1], _vertices[2],
					   t, u, v, epsilon);
  }

 private:

  Vec3r	_normal;
};

} // end of namespace Geometry

#endif // POLYGON_H