// @(#)root/g4root:$Id: TG4RootNavigator.h 20882 2007-11-19 11:31:26Z rdm $
// Author: Andrei Gheata   07/08/06

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#ifndef ROOT_TG4RootNavigator
#define ROOT_TG4RootNavigator


//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TG4Navigator                                                         //
//                                                                      //
// GEANT4 navigator using directly a TGeo geometry.                     //
//                                                                      //
// All navigation methods requred by G4 tracking are implemented by     //
// this class by invoking the corresponding functionality of ROOT       //
// geometry modeler.                                                    //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

#ifndef G4NAVIGATOR_HH
#include "G4Navigator.hh"
#endif

class TGeoManager;
class TG4RootDetectorConstruction;

class TG4RootNavigator : public G4Navigator {

protected:
   TGeoManager          *fGeometry;        // TGeo geometry manager
   TG4RootDetectorConstruction *fDetConstruction; // G4Root detector construction

   Bool_t                fStepEntering;    // Next step is entering daughter
   Bool_t                fStepExiting;     // Next step is exiting current volume
   G4ThreeVector         fNextPoint;       // Crossing point with next boundary
   G4ThreeVector         fSafetyOrig;      // Last computed safety origin
   G4double              fLastSafety;      // Last computed safety
private:
   G4VPhysicalVolume *SynchronizeHistory();
   TGeoNode          *SynchronizeGeoManager();
      
public:
   TG4RootNavigator();
   TG4RootNavigator(TG4RootDetectorConstruction *dc);
   virtual ~TG4RootNavigator();

   void              SetDetectorConstruction(TG4RootDetectorConstruction *dc);
   G4NavigationHistory *GetHistory() {return &fHistory;}
   
   // Virtual methods for navigation
   virtual  G4double ComputeStep(const G4ThreeVector &pGlobalPoint,
                                const G4ThreeVector &pDirection,
                                const G4double pCurrentProposedStepLength,
                                      G4double  &pNewSafety);
   virtual
   G4VPhysicalVolume* ResetHierarchyAndLocate(const G4ThreeVector &point,
                                              const G4ThreeVector &direction,
                                              const G4TouchableHistory &h);
   virtual
   G4VPhysicalVolume* LocateGlobalPointAndSetup(const G4ThreeVector& point,
                                              const G4ThreeVector* direction=0,
                                              const G4bool pRelativeSearch=true,
                                              const G4bool ignoreDirection=true);
   virtual void LocateGlobalPointWithinVolume(const G4ThreeVector& position);
//   virtual void LocateGlobalPointAndUpdateTouchableHandle(
//                 const G4ThreeVector&       position,
//                 const G4ThreeVector&       direction,
//                       G4TouchableHandle&   oldTouchableToUpdate,
//                 const G4bool               RelativeSearch = true);
   virtual G4double ComputeSafety(const G4ThreeVector &globalpoint,
                                  const G4double pProposedMaxLength = DBL_MAX);
   virtual G4TouchableHistoryHandle CreateTouchableHistoryHandle() const;
   virtual G4ThreeVector GetLocalExitNormal(G4bool* valid);

//   ClassDef(TG4RootNavigator,0)  // Class defining a G4Navigator based on ROOT geometry
};
#endif