#ifndef AliHBTTwoTrackEffFctn_H
#define AliHBTTwoTrackEffFctn_H
//____________________________________________________________________
//////////////////////////////////////////////////////////////////////
//                                                                  //
//  class AliHBTTwoTrackEffFctn                                     //
//                                                                  //
//  classes for calculating two track efficiency of the tracking    //
//  binning is done using value of simulated pair montum difference // 
//  pair must be recontructed, that is why we need both pairs       //
//  (simulated and recontructed), thus functions are "two pair"     //
//  Piotr.Skowronski@cern.ch                                        //
//                                                                  //
//////////////////////////////////////////////////////////////////////
#include "AliHBTPair.h"
#include "AliHBTFunction.h"

class AliHBTTwoTrackEffFctn: public AliHBTOnePairFctn1D, public AliHBTCorrelFunction
 {
  public:
    AliHBTTwoTrackEffFctn();
    AliHBTTwoTrackEffFctn(Int_t nbins, Double_t maxval, Double_t minval);
    virtual ~AliHBTTwoTrackEffFctn(){}
    TH1* GetResult();
  protected:
    Double_t GetValue(AliHBTPair* pair){return pair->GetDeltaP();}
  private:
    ClassDef(AliHBTTwoTrackEffFctn,2)
 };

class AliHBTTwoTrackEffFctn3D: public AliHBTOnePairFctn3D, public AliHBTCorrelFunction
 {
  public:
    AliHBTTwoTrackEffFctn3D();
    virtual ~AliHBTTwoTrackEffFctn3D(){}

    void ProcessSameEventParticles(AliHBTPair* /*pair*/){}
    void ProcessDiffEventParticles(AliHBTPair* /*pair*/){}

  protected:
    void GetValues(AliHBTPair*,Double_t&, Double_t&,Double_t&);
  private:
    ClassDef(AliHBTTwoTrackEffFctn3D,2)
 };
#endif