G4BOptnForceFreeFlight.cc

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#include "G4BOptnForceFreeFlight.hh"
#include "G4ILawForceFreeFlight.hh"
#include "G4BiasingProcessInterface.hh"
#include "G4Step.hh"



G4BOptnForceFreeFlight::G4BOptnForceFreeFlight(G4String name)
  : G4VBiasingOperation    ( name ),
    fCumulatedWeightChange ( -1.0 ),
    fInitialTrackWeight    ( -1.0 ),
    fOperationComplete     ( true )
{
  fForceFreeFlightInteractionLaw = new G4ILawForceFreeFlight("LawForOperation"+name);
}

G4BOptnForceFreeFlight::~G4BOptnForceFreeFlight()
{
  if ( fForceFreeFlightInteractionLaw ) delete fForceFreeFlightInteractionLaw;
}

const G4VBiasingInteractionLaw* G4BOptnForceFreeFlight::ProvideOccurenceBiasingInteractionLaw( const G4BiasingProcessInterface*, G4ForceCondition& proposeForceCondition )
{
  fOperationComplete = false;
  proposeForceCondition = Forced;
  return fForceFreeFlightInteractionLaw;
}

G4bool G4BOptnForceFreeFlight::DenyProcessPostStepDoIt( const G4BiasingProcessInterface*, const G4Track*, const G4Step* step, G4double& proposedWeight )
{
  // -- force free flight always deny process to apply its doit.
  // -- if reaching boundary, track is restored with non-zero weight
  if ( fInitialTrackWeight <= DBL_MIN )
    {
      G4ExceptionDescription ed;
      ed << " Initial track weight is null ! " << G4endl;
      G4Exception(" G4BOptnForceFreeFlight::DenyProcessPostStepDoIt(...)",
          "BIAS.GEN.05",
          JustWarning,
          ed);
    }
  if ( fCumulatedWeightChange <= DBL_MIN )
    {
      G4ExceptionDescription ed;
      ed << " Cumulated weight is null ! " << G4endl;
      G4Exception(" G4BOptnForceFreeFlight::DenyProcessPostStepDoIt(...)",
          "BIAS.GEN.06",
          JustWarning,
          ed);
    }
  if ( step->GetPostStepPoint()->GetStepStatus() == fGeomBoundary )
    {
      if ( proposedWeight <= DBL_MIN ) proposedWeight  = fCumulatedWeightChange * fInitialTrackWeight;
      else                             proposedWeight *= fCumulatedWeightChange;
    }
  
  return true;
}

G4VParticleChange* G4BOptnForceFreeFlight::ApplyFinalStateBiasing( const G4BiasingProcessInterface* callingProcess,
                                   const G4Track* track,
                                   const G4Step* step,
                                   G4bool& forceFinalState)
{
  // -- If the track is reaching the volume boundary, its free flight ends. In this case, its zero
  // -- weight is brought back to non-zero value: its initial weight is restored by the first
  // -- ApplyFinalStateBiasing operation called, and the weight for force free flight is applied
  // -- is applied by each operation.
  // -- If the track is not reaching the volume boundary, it zero weight flight continues.

  fParticleChange.Initialize( *track );
  forceFinalState    = true;
  if ( step->GetPostStepPoint()->GetStepStatus() == fGeomBoundary )
    {
      // -- Sanity checks:
      if ( fInitialTrackWeight <= DBL_MIN )
    {
      G4ExceptionDescription ed;
      ed << " Initial track weight is null ! " << G4endl;
      G4Exception(" G4BOptnForceFreeFlight::ApplyFinalStateBiasing(...)",
              "BIAS.GEN.05",
              JustWarning,
              ed);
    }
      if ( fCumulatedWeightChange <= DBL_MIN )
    {
      G4ExceptionDescription ed;
      ed << " Cumulated weight is null ! " << G4endl;
      G4Exception(" G4BOptnForceFreeFlight::ApplyFinalStateBiasing(...)",
              "BIAS.GEN.06",
              JustWarning,
              ed);
    }

      G4double proposedWeight = track->GetWeight();
      if ( callingProcess->GetIsFirstPostStepDoItInterface() ) proposedWeight  = fCumulatedWeightChange * fInitialTrackWeight;
      else                                                     proposedWeight *= fCumulatedWeightChange;
      fParticleChange.ProposeWeight(proposedWeight);
      fOperationComplete = true;
    }
  
  return &fParticleChange;
}


void G4BOptnForceFreeFlight::AlongMoveBy( const G4BiasingProcessInterface*, const G4Step*, G4double weightChange )
{
  fCumulatedWeightChange *= weightChange;
}