G4BOptnForceCommonTruncatedExp.cc

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#include "G4BOptnForceCommonTruncatedExp.hh"
#include "G4ILawCommonTruncatedExp.hh"
#include "G4TransportationManager.hh"

#include "Randomize.hh"
#include "G4BiasingProcessInterface.hh"

G4BOptnForceCommonTruncatedExp::G4BOptnForceCommonTruncatedExp(G4String name)
  : G4VBiasingOperation(name),
    fInteractionOccured(false)
{
  fCommonTruncatedExpLaw = new G4ILawCommonTruncatedExp("ExpLawForOperation"+name);
  fCommonTruncatedExpLaw->SetOperation( this );
  fTotalCrossSection = 0.0;
}

G4BOptnForceCommonTruncatedExp::~G4BOptnForceCommonTruncatedExp()
{}

const G4VBiasingInteractionLaw* G4BOptnForceCommonTruncatedExp::ProvideOccurenceBiasingInteractionLaw( const G4BiasingProcessInterface* )
{
  return fCommonTruncatedExpLaw;
}

G4ForceCondition  G4BOptnForceCommonTruncatedExp::ProposeForceCondition( const G4ForceCondition )
{
  return Forced;
}

G4double G4BOptnForceCommonTruncatedExp::ProposeAlongStepLimit( const G4BiasingProcessInterface* callingProcess )
{
  if ( callingProcess->GetWrappedProcess() ==  fProcessToApply )
    return  fCommonTruncatedExpLaw->GetInteractionDistance();
  else return DBL_MAX;
}

G4GPILSelection   G4BOptnForceCommonTruncatedExp::ProposeGPILSelection( const G4GPILSelection )
{
  return CandidateForSelection;
}

G4bool G4BOptnForceCommonTruncatedExp::DenyProcessPostStepDoIt( const G4BiasingProcessInterface* callingProcess,
                                const G4Track*, const G4Step* step, G4double& )
{
  G4double processGPIL = callingProcess->GetPostStepGPIL() < callingProcess->GetAlongStepGPIL() ?
    callingProcess->GetPostStepGPIL() : callingProcess->GetAlongStepGPIL() ;
  if ( processGPIL <= step->GetStepLength() )
    {
      G4bool denyProcess = (callingProcess->GetWrappedProcess() != fProcessToApply );
      fInteractionOccured = (fInteractionOccured || !denyProcess);
      return denyProcess;
    }
  else return true;
}

G4double G4BOptnForceCommonTruncatedExp::GetTriggeredProcessXSfraction()
{
  return fCrossSections[fProcessToApply] / fTotalCrossSection;
}

void G4BOptnForceCommonTruncatedExp::PostStepInteractionOccured( const G4VProcess* )
{
}

void G4BOptnForceCommonTruncatedExp::AddCrossSection( const G4VProcess* process, G4double crossSection )
{
  fTotalCrossSection += crossSection;
  fCrossSections[process] = crossSection;
  fNumberOfSharing = fCrossSections.size();
  fCommonTruncatedExpLaw->SetNumberOfSharing  ( fNumberOfSharing );
  fCommonTruncatedExpLaw->SetForceCrossSection( fTotalCrossSection );
}


void G4BOptnForceCommonTruncatedExp::Initialize( const G4Track* track )
{
  fCrossSections.clear();
  fTotalCrossSection  = 0.0;
  fNumberOfSharing    = 0;
  fProcessToApply     = 0;
  fInitialMomentum    = track->GetMomentum();

  fCommonTruncatedExpLaw->reset();
  G4VSolid* currentSolid = track->GetVolume()->GetLogicalVolume()->GetSolid();
  G4ThreeVector  localPosition = (G4TransportationManager::GetTransportationManager()->
                  GetNavigatorForTracking()->
                  GetGlobalToLocalTransform()).TransformPoint(track->GetPosition());
  G4ThreeVector localDirection = (G4TransportationManager::GetTransportationManager()->
                  GetNavigatorForTracking()->
                  GetGlobalToLocalTransform()).TransformAxis(track->GetMomentumDirection());
  fMaximumDistance = currentSolid->DistanceToOut(localPosition, localDirection);
  if ( fMaximumDistance <= DBL_MIN )  fMaximumDistance = 0.0;
  fCommonTruncatedExpLaw->SetMaximumDistance( fMaximumDistance );
}


void G4BOptnForceCommonTruncatedExp::UpdateForStep( const G4Step* step )
{
  fCrossSections.clear();
  fTotalCrossSection  = 0.0;
  fNumberOfSharing    = 0;
  fProcessToApply     = 0;

  fCommonTruncatedExpLaw->UpdateForStep( step->GetStepLength() );
  fMaximumDistance = fCommonTruncatedExpLaw->GetMaximumDistance();
}

void G4BOptnForceCommonTruncatedExp::Sample()
{
  fCommonTruncatedExpLaw->reset();
  fCommonTruncatedExpLaw->Sample();
  ChooseProcessToApply(); 
}


void G4BOptnForceCommonTruncatedExp::ChooseProcessToApply()
{
  G4double sigmaRand = G4UniformRand() * fTotalCrossSection;
  G4double sigmaSelect = 0.0;
  for ( std::map< const G4VProcess*, G4double>::const_iterator it = fCrossSections.begin();
    it != fCrossSections.end();
    it++)
    {
      sigmaSelect += (*it).second;
      if ( sigmaRand <= sigmaSelect )
    {
      fProcessToApply = (*it).first;
      break;
    }
    }
}