/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

#include "AliTRDmcTrack.h"
#include "AliTRDgeometry.h"

ClassImp(AliTRDmcTrack)

//_____________________________________________________________________________
AliTRDmcTrack::AliTRDmcTrack() 
{ 

  //
  // Default constructor 
  //

  fLab = -1; 
  fPrimary = kFALSE; 
  fMass = 0; 
  fCharge = 0;
  fN = 0; 
  
  for(Int_t i=0; i<200; i++) fIndex[i]=-1;
  
  for(Int_t i=0; i<6; i++) {
    for(Int_t j=0; j<3; j++) { 
      Pin[i][j]=0.; 
      Pout[i][j] = 0.;
    }
  }

}

//_____________________________________________________________________________
AliTRDmcTrack::AliTRDmcTrack(Int_t label, Bool_t primary, Float_t mass
			    ,Int_t charge, Int_t pdg) 
{ 

  //
  // Main constructor 
  //

  fLab = label; 
  fPrimary = primary; 
  fMass = mass; 
  fCharge = charge;
  fPDG = pdg;
  fN = 0; 
  
  for(Int_t i=0; i<200; i++) fIndex[i]=-1;
  
  for(Int_t i=0; i<6; i++) {
    for(Int_t j=0; j<3; j++) { 
      Pin[i][j]=0.; 
      Pout[i][j] = 0.;
    }
  }

}

//_____________________________________________________________________________
void AliTRDmcTrack::GetPxPyPz(Double_t& px, Double_t& py, Double_t& pz, 
                              Int_t opt) const 
{
  //
  // Returns momentum components at the entrance (opt >= 0), or
  // exit (opt < 0) of TRD. 
  //

  Int_t i;

  if(opt >= 0) {
    for(i = 0; i < AliTRDgeometry::Nplan(); i++) {
      if(  Pin[i][0] * Pin[i][0]
         + Pin[i][1] * Pin[i][1]
         + Pin[i][2] * Pin[i][2] > 0.0005) break;
    }
    px = Pin[0][0]; py = Pin[0][1]; pz = Pin[0][2];
  }
  else {
    for(i = AliTRDgeometry::Nplan() - 1; i >= 0; i--) {
      if(  Pout[i][0] * Pout[i][0]
         + Pout[i][1] * Pout[i][1]
         + Pout[i][2] * Pout[i][2] > 0.0005) break;
    }
    px = Pout[i][0]; py = Pout[i][1]; pz = Pout[i][2];
  }

  return;

}

//_____________________________________________________________________________
void AliTRDmcTrack::GetPlanePxPyPz(Double_t& px, Double_t& py, Double_t& pz, 
                                   Int_t plane, Int_t opt) const 
{
  //
  // Returns momentum components at the entrance (opt >= 0), or
  // exit (opt < 0) of TRD plane <plane>. 
  //

  if(opt >= 0) {
    px = Pin[plane][0]; py = Pin[plane][1]; pz = Pin[plane][2];
  }
  else {
    px = Pout[plane][0]; py = Pout[plane][1]; pz = Pout[plane][2];
  }

  return;

}