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// $Id: G4VParallelStepper.hh,v 1.8 2006/06/29 18:16:47 gunter Exp $
// GEANT4 tag $Name: geant4-08-01 $
//
// ----------------------------------------------------------------------
// Class G4VParallelStepper
//
// Class description:
//
// This interface is used internally by importance sampling and scoring
// in a "parallel" geometry.
// It abstracts a parallel stepper which servs to comunicate
// information about a G4GeometryCellStep between the "transportation"
// (done by G4ParallelTransport) of a track in a "parallel" geometry
// and a scorer for that geometry.

// Author: Michael Dressel (Michael.Dressel@cern.ch)
// ----------------------------------------------------------------------
#ifndef G4VParallelStepper_hh
#define G4VParallelStepper_hh G4VParallelStepper_hh

#include "G4GeometryCellStep.hh"

class G4VParallelStepper
{

public:  // with description

  G4VParallelStepper();
  virtual ~G4VParallelStepper();

  virtual G4GeometryCellStep GetPStep() const = 0;
    // get the current G4GeometryCellStep

  virtual void Init(const G4GeometryCell &agCell) = 0;
    // initialise the parallel stepper and the G4GeometryCellStep
    // pre and post G4GeometryCell of the step are set equal

  virtual void Update(const G4GeometryCell &agCell) = 0;
    // to be called when crossing a boundary of the 
    // "parallel" geometry to update the G4GeometryCellStep

  virtual void UnSetCrossBoundary() = 0;
    // to be called to unset the fCrossBoundary member of the G4GeometryCellStep

};

#endif