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// $Id: G4PrimaryTransformer.cc,v 1.27 2006/06/29 18:09:58 gunter Exp $
// GEANT4 tag $Name: geant4-09-03 $
//

#include "G4PrimaryTransformer.hh"
#include "G4Event.hh"
#include "G4PrimaryVertex.hh"
#include "G4ParticleDefinition.hh"
#include "G4DynamicParticle.hh"
#include "G4Track.hh"
#include "G4ThreeVector.hh"
#include "G4DecayProducts.hh"
#include "G4UnitsTable.hh"
#include "G4ios.hh"
#include "Randomize.hh"

G4PrimaryTransformer::G4PrimaryTransformer()
:verboseLevel(0),trackID(0),unknown(0),unknownParticleDefined(false)
{
  particleTable = G4ParticleTable::GetParticleTable();
  CheckUnknown();
}

G4PrimaryTransformer::~G4PrimaryTransformer()
{;}

void G4PrimaryTransformer::CheckUnknown()
{
  unknown = particleTable->FindParticle("unknown");
  if(unknown) 
  { unknownParticleDefined = true; }
  else
  { unknownParticleDefined = false; }
}
    
G4TrackVector* G4PrimaryTransformer::GimmePrimaries(G4Event* anEvent,G4int trackIDCounter)
{
  trackID = trackIDCounter;

  //TV.clearAndDestroy();
  for( size_t ii=0; ii<TV.size();ii++)
  { delete TV[ii]; }
  TV.clear();
  G4int n_vertex = anEvent->GetNumberOfPrimaryVertex();
  if(n_vertex==0) return 0; 
  for( G4int i=0; i<n_vertex; i++ )
  { GenerateTracks( anEvent->GetPrimaryVertex(i) ); }
  return &TV;
}

void G4PrimaryTransformer::GenerateTracks(G4PrimaryVertex* primaryVertex)
{
  G4double X0 = primaryVertex->GetX0();
  G4double Y0 = primaryVertex->GetY0();
  G4double Z0 = primaryVertex->GetZ0();
  G4double T0 = primaryVertex->GetT0();
  G4double WV = primaryVertex->GetWeight();

#ifdef G4VERBOSE
  if(verboseLevel>1)
  { 
    G4cout << "G4PrimaryTransformer::PrimaryVertex ("
           << X0 / mm << "(mm),"
           << Y0 / mm << "(mm),"
           << Z0 / mm << "(mm),"
           << T0 / nanosecond << "(nsec))" << G4endl;
  }
#endif

  G4PrimaryParticle* primaryParticle = primaryVertex->GetPrimary();
  while( primaryParticle != 0 )
  {
    GenerateSingleTrack( primaryParticle, X0, Y0, Z0, T0, WV );
    primaryParticle = primaryParticle->GetNext();
  }
}

void G4PrimaryTransformer::GenerateSingleTrack
     (G4PrimaryParticle* primaryParticle,
      G4double x0,G4double y0,G4double z0,G4double t0,G4double wv)
{
  static G4ParticleDefinition* optPhoton = 0;
  static G4int nWarn = 0;
  if(!optPhoton) optPhoton = particleTable->FindParticle("opticalphoton");

  G4ParticleDefinition* partDef = GetDefinition(primaryParticle);
  if(!IsGoodForTrack(partDef))
  // The particle cannot be converted to G4Track, check daughters
  {
#ifdef G4VERBOSE
    if(verboseLevel>2)
    {
      G4cout << "Primary particle (PDGcode " << primaryParticle->GetPDGcode()
             << ") --- Ignored" << G4endl;
    }
#endif 
    G4PrimaryParticle* daughter = primaryParticle->GetDaughter();
    while(daughter)
    {
      GenerateSingleTrack(daughter,x0,y0,z0,t0,wv);
      daughter = daughter->GetNext();
    }
  }

  // The particle is defined in GEANT4
  else
  {
    // Create G4DynamicParticle object
#ifdef G4VERBOSE
    if(verboseLevel>1)
    {
      G4cout << "Primary particle (" << partDef->GetParticleName()
             << ") --- Transfered with momentum " << primaryParticle->GetMomentum()
             << G4endl;
    }
#endif
    G4DynamicParticle* DP = 
      new G4DynamicParticle(partDef,primaryParticle->GetMomentum());
    if(partDef==optPhoton && primaryParticle->GetPolarization().mag2()==0.)
    {
      if(nWarn<10)
      {
        G4Exception("G4PrimaryTransformer::GenerateSingleTrack","ZeroPolarization",JustWarning,
                    "Polarization of the optical photon is null. Random polarization is assumed.");
        G4cerr << "This warning message is issued up to 10 times." << G4endl;
        nWarn++;
      }

      G4double angle = G4UniformRand() * 360.0*deg;
      G4ThreeVector normal (1., 0., 0.);
      G4ThreeVector kphoton = DP->GetMomentumDirection();
      G4ThreeVector product = normal.cross(kphoton);
      G4double modul2       = product*product;

      G4ThreeVector e_perpend (0., 0., 1.);
      if (modul2 > 0.) e_perpend = (1./std::sqrt(modul2))*product;
      G4ThreeVector e_paralle    = e_perpend.cross(kphoton);

      G4ThreeVector polar = std::cos(angle)*e_paralle + std::sin(angle)*e_perpend;
      DP->SetPolarization(polar.x(),polar.y(),polar.z());
    }
    else
    {
      DP->SetPolarization(primaryParticle->GetPolX(),
                          primaryParticle->GetPolY(),
                          primaryParticle->GetPolZ());
    }
    if(primaryParticle->GetProperTime()>0.0)
    { DP->SetPreAssignedDecayProperTime(primaryParticle->GetProperTime()); }
    // Set Charge if it is specified
    if (primaryParticle->GetCharge()<DBL_MAX) {
      DP->SetCharge(primaryParticle->GetCharge());
    } 
    // Set Mass if it is specified
    G4double pmas = primaryParticle->GetMass();
    if(pmas>=0.)
    { DP->SetMass(pmas); }
    // Set decay products to the DynamicParticle
    SetDecayProducts( primaryParticle, DP );
    // Set primary particle
    DP->SetPrimaryParticle(primaryParticle);
    // Set PDG code if it is different from G4ParticleDefinition
    if(partDef->GetPDGEncoding()==0 && primaryParticle->GetPDGcode()!=0)
    {
      DP->SetPDGcode(primaryParticle->GetPDGcode());
    }
    // Check the particle is properly constructed
    if(!CheckDynamicParticle(DP))
    {
      delete DP;
      return;
    }
    // Create G4Track object
    G4Track* track = new G4Track(DP,t0,G4ThreeVector(x0,y0,z0));
    // Set trackID and let primary particle know it
    trackID++;
    track->SetTrackID(trackID);
    primaryParticle->SetTrackID(trackID);
    // Set parentID to 0 as a primary particle
    track->SetParentID(0);
    // Set weight ( vertex weight * particle weight )
    track->SetWeight(wv*(primaryParticle->GetWeight()));
    // Store it to G4TrackVector
    TV.push_back( track );
  }
}

void G4PrimaryTransformer::SetDecayProducts
      (G4PrimaryParticle* mother, G4DynamicParticle* motherDP)
{
  G4PrimaryParticle* daughter = mother->GetDaughter();
  if(!daughter) return;
  G4DecayProducts* decayProducts = (G4DecayProducts*)(motherDP->GetPreAssignedDecayProducts() );
  if(!decayProducts)
  {
    decayProducts = new G4DecayProducts(*motherDP);
    motherDP->SetPreAssignedDecayProducts(decayProducts);
  }
  while(daughter)
  {
    G4ParticleDefinition* partDef = GetDefinition(daughter);
    if(!IsGoodForTrack(partDef))
    { 
#ifdef G4VERBOSE
      if(verboseLevel>2)
      {
        G4cout << " >> Decay product (PDGcode " << daughter->GetPDGcode()
               << ") --- Ignored" << G4endl;
      }
#endif 
      SetDecayProducts(daughter,motherDP);
    }
    else
    {
#ifdef G4VERBOSE
      if(verboseLevel>1)
      {
        G4cout << " >> Decay product (" << partDef->GetParticleName()
               << ") --- Attached with momentum " << daughter->GetMomentum()
               << G4endl;
      }
#endif
      G4DynamicParticle*DP 
        = new G4DynamicParticle(partDef,daughter->GetMomentum());
      DP->SetPrimaryParticle(daughter);
      // Decay proper time for daughter
      if(daughter->GetProperTime()>0.0)
      { DP->SetPreAssignedDecayProperTime(daughter->GetProperTime()); }
      // Set Charge is specified
      if (daughter->GetCharge()<DBL_MAX) {
        DP->SetCharge(daughter->GetCharge());
      } 
      G4double pmas = daughter->GetMass();
      if(pmas>=0.)
      { DP->SetMass(pmas); }
      decayProducts->PushProducts(DP);
      SetDecayProducts(daughter,DP);
      // Check the particle is properly constructed
      if(!CheckDynamicParticle(DP))
      {
        delete DP;
        return;
      }
    }
    daughter = daughter->GetNext();
  }
}

void G4PrimaryTransformer::SetUnknnownParticleDefined(G4bool vl)
{
  unknownParticleDefined = vl;
  if(unknownParticleDefined && !unknown)
  { G4cerr << "unknownParticleDefined cannot be set true because G4UnknownParticle is not defined in the physics list."
           << G4endl << "Command ignored." << G4endl;
    unknownParticleDefined = false;
  }
}

G4bool G4PrimaryTransformer::CheckDynamicParticle(G4DynamicParticle*DP)
{
  if(IsGoodForTrack(DP->GetDefinition())) return true;
  G4DecayProducts* decayProducts = (G4DecayProducts*)(DP->GetPreAssignedDecayProducts());
  if(decayProducts && decayProducts->entries()>0) return true;
  G4cerr << G4endl
         << "G4PrimaryTransformer: a shortlived primary particle is found" << G4endl
         << " without any valid decay table nor pre-assigned decay mode." << G4endl;
  G4Exception("G4PrimaryTransformer","InvalidPrimary",JustWarning,
              "This primary particle will be ignored.");
  return false;
}

G4ParticleDefinition* G4PrimaryTransformer::GetDefinition(G4PrimaryParticle*pp)
{
  G4ParticleDefinition* partDef = pp->GetG4code();
  if(!partDef) partDef = particleTable->FindParticle(pp->GetPDGcode());
  if(unknownParticleDefined && ((!partDef)||partDef->IsShortLived())) partDef = unknown;
  return partDef;
}

G4bool G4PrimaryTransformer::IsGoodForTrack(G4ParticleDefinition* pd)
{
  if(!pd)
  { return false; }
  else if(!(pd->IsShortLived()))
  { return true; }
// Following two lines should be removed if the user does not want to make shortlived 
// primary particle with proper decay table to be converted into a track.
  else if(pd->GetDecayTable())
  { return true; }
  return false;
}