/**************************************************************************
 * 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.                  *
 **************************************************************************/

/*
$Log$
*/

#include <TParticle.h>

#include "AliGeant3.h"
#include "AliRun.h"
#include "TGeant3.h"
#include "AliCallf77.h" 

#ifndef WIN32

# define rxgtrak rxgtrak_
# define rxstrak rxstrak_
# define rxkeep  rxkeep_ 
# define rxouth  rxouth_
#else

# define rxgtrak RXGTRAK 
# define rxstrak RXSTRAK 
# define rxkeep  RXKEEP  
# define rxouth  RXOUTH
#endif

ClassImp(AliGeant3)

AliGeant3::AliGeant3()
{
  new TGeant3();
}

AliGeant3::AliGeant3(const char *title) : 
  AliVMC("ALICE Virtual MC for Geant3",title)
{
  new TGeant3(title);
}

void AliGeant3::FinishGeometry()
{
  gMC->FinishGeometry();
  //Create the color table
  gMC->SetColors();
}

void AliGeant3::BuildPhysics()
{
  ((TGeant3*)gMC)->Gphysi();
}

void AliGeant3::ProcessEvent()
{
  ((TGeant3*)gMC)->Gtrigi();
  ((TGeant3*)gMC)->Gtrigc();
  ((TGeant3*)gMC)->Gtrig();
}

//_____________________________________________________________________________
//
//                 Interfaces to Fortran
//
//_____________________________________________________________________________

extern "C" void type_of_call  rxgtrak (Int_t &mtrack, Int_t &ipart, Float_t *pmom, 
				       Float_t &e, Float_t *vpos, Float_t *polar,
				       Float_t &tof)
{
  //
  //     Fetches next track from the ROOT stack for transport. Called by the
  //     modified version of GTREVE.
  //
  //              Track number in the ROOT stack. If MTRACK=0 no
  //      mtrack  more tracks are left in the stack to be
  //              transported.
  //      ipart   Particle code in the GEANT conventions.
  //      pmom[3] Particle momentum in GeV/c
  //      e       Particle energy in GeV
  //      vpos[3] Particle position
  //      tof     Particle time of flight in seconds
  //
  Int_t pdg;
  gAlice->GetNextTrack(mtrack, pdg, pmom, e, vpos, polar, tof);
  ipart = gMC->IdFromPDG(pdg);
  mtrack++;
}

//_____________________________________________________________________________
extern "C" void type_of_call 
#ifndef WIN32
rxstrak (Int_t &keep, Int_t &parent, Int_t &ipart, Float_t *pmom, 
	       Float_t *vpos, Float_t &tof, const char* cmech, Int_t &ntr, const int cmlen)
#else
rxstrak (Int_t &keep, Int_t &parent, Int_t &ipart, Float_t *pmom,
	 Float_t *vpos, Float_t &tof, const char* cmech, const int cmlen,
	 Int_t &ntr)
#endif
{
  //
  //     Fetches next track from the ROOT stack for transport. Called by GUKINE
  //     and GUSTEP.
  //
  //              Status of the track. If keep=0 the track is put
  //      keep    on the ROOT stack but it is not fetched for
  //              transport.
  //      parent  Parent track. If parent=0 the track is a primary.
  //              In GUSTEP the routine is normally called to store
  //              secondaries generated by the current track whose
  //              ROOT stack number is MTRACK (common SCKINE.
  //      ipart   Particle code in the GEANT conventions.
  //      pmom[3] Particle momentum in GeV/c
  //      vpos[3] Particle position
  //      tof     Particle time of flight in seconds
  //
  //      cmech   (CHARACTER*10) Particle origin. This field is user
  //              defined and it is not used inside the GALICE code.
  //      ntr     Number assigned to the particle in the ROOT stack.
  //
  char mecha[11];
  Float_t polar[3]={0.,0.,0.};
  for(int i=0; i<10 && i<cmlen; i++) mecha[i]=cmech[i];
  mecha[10]=0;
  Int_t pdg=gMC->PDGFromId(ipart);
  gAlice->SetTrack(keep, parent-1, pdg, pmom, vpos, polar, tof, mecha, ntr);
  ntr++;
}

//_____________________________________________________________________________
extern "C" void type_of_call  rxkeep(const Int_t &n)
{
  if( NULL==gAlice ) exit(1);
  
  if( n<=0 || n>gAlice->Particles()->GetEntries() )
    {
      printf("  Bad index n=%d must be 0<n<=%d\n",
	     n,gAlice->Particles()->GetEntries());
      exit(1);
    }
  
  ((TParticle*)(gAlice->Particles()->UncheckedAt(n-1)))->SetBit(Keep_Bit);
}

//_____________________________________________________________________________
extern "C" void type_of_call  rxouth ()
{
  //
  // Called by Gtreve at the end of each primary track
  //
  gAlice->FinishPrimary();
}