siscone/protocones.h

// -*- C++ -*-
// File: protocones.h                                                        //
// Description: header file for stable cones determination (Cstable_cones)   //
// This file is part of the SISCone project.                                 //
// For more details, see http://projects.hepforge.org/siscone                //
//                                                                           //
// Copyright (c) 2006 Gavin Salam and Gregory Soyez                          //
//                                                                           //
// 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 St, Fifth Floor, Boston, MA 02110-1301, USA //
//                                                                           //
// $Revision:: 224                                                          $//
// $Date:: 2008-05-16 19:58:30 +0200 (Fri, 16 May 2008)                     $//

#ifndef __PROTOCONES_H__
#define __PROTOCONES_H__

#include "momentum.h"
#include "vicinity.h"
#include <stdio.h>
#include <vector>
#include <list>
#include "hash.h"

#include "defines.h"

namespace siscone{

class Cborder_store{
public:
  Cborder_store(Cmomentum * momentum, double centre_eta, double centre_phi) : 
    mom(momentum),  is_in(false) {
    angle = atan2(mom->phi - centre_phi, mom->eta - centre_eta);
  }

  Cmomentum * mom;  
  double angle;     
  bool   is_in;     
};


inline bool operator<(const Cborder_store & a, const Cborder_store & b) {
  return a.angle < b.angle;
}


class Cstable_cones : public Cvicinity{
 public:
  Cstable_cones();

  Cstable_cones(std::vector<Cmomentum> &_particle_list);

  ~Cstable_cones();

  void init(std::vector<Cmomentum> &_particle_list);

  int get_stable_cones(double _radius);

  std::vector<Cmomentum> protocones;

  hash_cones *hc;

  int nb_tot;
#ifdef DEBUG_STABLE_CONES
  int nb_hash_cones, nb_hash_occupied;
#endif

 protected:
  double R;

  double R2;

 private:
  Cmomentum cone;

  Cmomentum *child;

  Cvicinity_elm *centre;

  unsigned int centre_idx;

  unsigned int first_cone;

  int init_cone();

  int test_cone();

  int update_cone();

  /*
   * run through the vicinity of the current parent and for each child
   * indicate which members are cocircular...
   */
  void prepare_cocircular_lists();

  bool cocircular_check();

  void test_cone_cocircular(Cmomentum & borderless_cone, 
                            std::list<Cmomentum *> & border_list);

  void test_stability(Cmomentum & candidate, 
                      const std::vector<Cborder_store> & border_vect);

  void compute_cone_contents();

  void recompute_cone_contents();

  /*
   * if we have gone beyond the acceptable threshold of change, compute
   * the cone momentum from particle list.  in this version, we use the
   * 'pincluded' information from the Cvicinity class, but we don't
   * change the member cone, only the locally supplied one
   */
  void recompute_cone_contents_if_needed(Cmomentum & this_cone, double & this_dpt);

  int proceed_with_stability();

  /*
   * circle intersection.
   * computes the intersection with a circle of given centre and radius.
   * The output takes the form of a checkxor of the intersection's particles
   *  - cx    circle centre x coordinate
   *  - cy    circle centre y coordinate
   * return the checkxor for the intersection
   ******************************************************************/
  Creference circle_intersect(double cx, double cy);

  Cmomentum cone_candidate;

  std::vector<Cmomentum*> child_list;

  std::vector< std::pair<Creference,Creference> > multiple_centre_done;

  // information for updating cone contents to avoid rounding errors
  double dpt;          

  inline bool is_inside(Cmomentum *centre, Cmomentum *v);
};

/*
 * compute the absolute value of the difference between 2 angles.
 * We take care of the 2pi periodicity
 * \param angle1   first angle
 * \param angle2   second angle
 * \return the absolute value of the difference between the angles
 *****************************************************************/
inline double abs_dangle(double &angle1, double &angle2);

}
#endif