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// $Id: G4ParallelWeightWindowProcess.hh,v 1.10 2006/06/29 21:10:20 gunter Exp $
// GEANT4 tag $Name: geant4-08-01 $
//
// ----------------------------------------------------------------------
// Class G4ParallelWeightWindowProcess
//
// Class description:
//
// Used internally by weight window technique in a "parallel" geometry.
// This process is a forced post step process. It will apply
// weight window biasing on collisions or on collisions and
// boundaries according to the G4PlaceOfAction argument. 
// It is not used in the case where it should apply only on boundaries.

// Author: Michael Dressel (Michael.Dressel@cern.ch)
// ----------------------------------------------------------------------
#ifndef G4ParallelWeightWindowProcess_hh
#define G4ParallelWeightWindowProcess_hh G4ParallelWeightWindowProcess_hh

#include "G4VProcess.hh"
#include "G4VTrackTerminator.hh"
#include "G4PlaceOfAction.hh"

class G4SamplingPostStepAction;
class G4VWeightWindowExaminer;
class G4Nsplit_Weight;
class G4VParallelStepper;
class G4VParallelStepper;

class G4ParallelWeightWindowProcess : public G4VProcess,\
                                      public G4VTrackTerminator
{

public:  // with description

  G4ParallelWeightWindowProcess(const G4VWeightWindowExaminer 
                                &aWeightWindowExaminer,
                                G4VParallelStepper &aStepper,
                                const G4VTrackTerminator *TrackTerminator,
                                G4PlaceOfAction placeOfAction,
                                const G4String &aName = 
                                "ParallelWeightWindowProcess");  
    // initialise G4ParallelTransport and members

  virtual ~G4ParallelWeightWindowProcess();

  virtual G4double 
  PostStepGetPhysicalInteractionLength(const G4Track& aTrack,
                                       G4double   previousStepSize,
                                       G4ForceCondition* condition);
    // make process beeing forced
  virtual G4VParticleChange *PostStepDoIt(const G4Track&, const G4Step&);
    // apply weight window sampliing

  virtual void KillTrack() const;
    // used in case no scoring process follows that does the killing

  virtual const G4String &GetName() const;


public:  // without description

  //  no operation in  AtRestDoIt and  AlongStepDoIt

  virtual G4double 
  AlongStepGetPhysicalInteractionLength(const G4Track&,
                                        G4double  ,
                                        G4double  ,
                                        G4double& ,
                                        G4GPILSelection*);
  virtual G4double 
  AtRestGetPhysicalInteractionLength(const G4Track& ,
                                     G4ForceCondition*);
  
  virtual G4VParticleChange* 
  AtRestDoIt(const G4Track&, const G4Step&);


  virtual G4VParticleChange* 
  AlongStepDoIt(const G4Track&, const G4Step&);
  

private:

  G4ParallelWeightWindowProcess(const G4ParallelWeightWindowProcess &);
  G4ParallelWeightWindowProcess &operator=(const G4ParallelWeightWindowProcess &);
  
  virtual void Error(const G4String &m);

private:

  G4ParticleChange *fParticleChange;
  const G4VWeightWindowExaminer &fWeightWindowExaminer;
  G4VParallelStepper &fStepper;
  G4SamplingPostStepAction *fPostStepAction;
  G4PlaceOfAction fPlaceOfAction;
};

#endif