arr_lm_random_generator.h

很多二维 三维几何计算算法 C++ 类库

// Copyright (c) 2005  Tel-Aviv University (Israel).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh://scm.gforge.inria.fr/svn/cgal/branches/CGAL-3.3-branch/Arrangement_2/include/CGAL/Arr_point_location/Arr_lm_random_generator.h $
// $Id: Arr_lm_random_generator.h 30322 2006-04-14 15:07:17Z lsaboret $
// 
//
// Author(s)     : Idit Haran   <[e-mail]>
#ifndef CGAL_ARR_LM_RANDOM_GENERATOR_H
#define CGAL_ARR_LM_RANDOM_GENERATOR_H

/*! \file
* Definition of the Arr_random_landmarks_generator<Arrangement> template.
*/

#include <CGAL/Arr_point_location/Arr_lm_generator.h>
#include <CGAL/Random.h>

CGAL_BEGIN_NAMESPACE

/*! \class
* This class is related to the Landmarks point location, and given as 
* a parameter (or template parameter) to it. 
* It inherites from Arr_lm_generator and  implements the 
* function called "void _create_point_list(Point_list &)" 
* to creates the set of random landmarks.
*/
template <class Arrangement_, 
      class Nearest_neighbor_ 
        = Arr_landmarks_nearest_neighbor <typename Arrangement_::Traits_2> >
class Arr_random_landmarks_generator 
  : public Arr_landmarks_generator <Arrangement_, Nearest_neighbor_>
{
public:
  typedef Arrangement_                          Arrangement_2;
  typedef typename Arrangement_2::Traits_2      Traits_2;
  typedef Arr_random_landmarks_generator<Arrangement_2, Nearest_neighbor_>   
                                                Self;
  typedef typename Traits_2::Point_2            Point_2;
  typedef std::vector<Point_2>                  Points_set;
  typedef typename Arrangement_2::Vertex_const_iterator  
                                                Vertex_const_iterator;

protected:

  // Data members:
  int number_of_landmarks; 

private:

  /*! Copy constructor - not supported. */
  Arr_random_landmarks_generator (const Self& );

  /*! Assignment operator - not supported. */
  Self& operator= (const Self& );

  
public: 
    /*! Constructor. */
    Arr_random_landmarks_generator 
      (const Arrangement_2& arr, int lm_num = -1) : 
        Arr_landmarks_generator<Arrangement_2, Nearest_neighbor_> (arr), 
      number_of_landmarks (lm_num)
    {
      CGAL_PRINT_DEBUG("Arr_random_landmarks_generator constructor. "
        <<"number_of_landmarks = "<< number_of_landmarks); 

      this->build_landmarks_set();
    }

 /*! Destructor. */
  ~Arr_random_landmarks_generator () 
  {
    CGAL_PRINT_DEBUG("destructor lm_gen. number_of_lm = "<< number_of_landmarks);
  }

protected:
  /*!
   * create a set of random points. 
   * the number of points is given as a parametr to this class' constructor.
   * the random coordinates are chosen using CGAL::Random function.
   * The coordinates are of type double, and are selected randomly in the 
   * Arrangement's bounding rectangle. This is actually the bounding rectangle 
   * of the Arrangement's vertices 
   */
  virtual void _create_points_set (Points_set & points)
  {
    CGAL_PRINT_DEBUG("create_random_points_list");

    //find bounding box
    double x_min=0, x_max=0, y_min=0, y_max=0;
    double x,y;
    Vertex_const_iterator vit; 
    Arrangement_2 *arr = this->arrangement();

    for (vit=arr->vertices_begin(); vit != arr->vertices_end(); vit++)
    {
      x = CGAL::to_double(vit->point().x());
      y = CGAL::to_double(vit->point().y());
      if (x < x_min) x_min = x;
      if (x > x_max) x_max = x;
      if (y < y_min) y_min = y;
      if (y > y_max) y_max = y;
    }

    CGAL::Random     random;

    // n is the number of random points.
    //if n is not given in the constructor then this number
    //is set to be the number of vertices in the arrangement.
    int n; 
    if (number_of_landmarks > 0)
      n = number_of_landmarks;
    else
      n= arr->number_of_vertices();

    //loop n time 
    for (int i=0; i<n; i++) 
    {
      //create the random point
      double px = random.get_double(x_min, x_max);
      double py = random.get_double(y_min, y_max);
      Point_2 p(px, py);

      //put in a list 
      points.push_back(p); 

      CGAL_PRINT_DEBUG("random point "<<i<< " is= " << p);
    }
    CGAL_PRINT_DEBUG("end create_random_points_list");

  }

};

CGAL_END_NAMESPACE


#endif