// -*- C++ -*-
#ifndef RIVET_FinalStateBREIT_HH
#define RIVET_FinalStateBREIT_HH

#include "Rivet/Particle.hh"
#include "Rivet/Event.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/DISKinematics.hh"
#include "Rivet/Projection.hh"
#include "Rivet/Projections/DISLepton.hh"
#include "Rivet/Projections/Beam.hh"

 namespace Rivet {
 
    /// Project all final state particles 
   /// boosted to the breit frame, and store any in the current hemisphere.
   class FinalStateBreit: public FinalState {
 
   public:
     /// Constructor for Final State Breit
     FinalStateBreit(const DISKinematics& kinematicsp);

     /// Constructor for specific hemisphere 
     /// hemisphere ==0 no cut,=1 current frame, =2 remnant frame
     /// elim =0 not cut, =n cut on greater than n
     FinalStateBreit(const DISKinematics& kinematicsp,const int& hemisphere, const double& elim);
     
     /// Clone on the heap.
     virtual const Projection* clone() const {
       return new FinalStateBreit(*this);
     }

     ///Get the FSB Particles
     virtual const ParticleVector& fsbparticles() const {return _theFSBParticles;}

     virtual const FourMomentum& pgamma() const {return _pgammab;}
     
   protected:

     mutable FourMomentum _pgammab;

     mutable ParticleVector _theFSBParticles; 
     
     /// Apply the projection on the supplied event.
    void project(const Event& e);
  
     /// Compare projections.
     int compare(const Projection& p) const;
  
   };
 
 }

 #endif