// This code implementation is the intellectual property of
// the GEANT4 collaboration.
//
// By copying, distributing or modifying the Program (or any work
// based on the Program) you indicate your acceptance of this statement,
// and all its terms.
//
// $Id: G4Gamma.hh,v 1.3 1999/12/15 14:50:52 gunter Exp $
// GEANT4 tag $Name: geant4-02-00 $
//
// 
// ------------------------------------------------------------
//      GEANT 4 class header file
//
//      For information related to this code contact:
//      CERN, CN Division, ASD group
//      History: first implementation, based on object model of
//      4-th April 1996, G.Cosmo
// ****************************************************************
//  Added particle definitions, H.Kurashige, 19 April 1996
//  Revised, G.Cosmo, 6 June 1996
//  Added SetCuts, L.Urban, 12 June 1996
//  Added not static GetEnergyCuts() and GetLengthCuts(), G.Cosmo, 11 July 1996
// ----------------------------------------------------------------

// Each class inheriting from G4VBoson
// corresponds to a particle type; one and only one
// instance for each class is guaranteed.

#ifndef G4Gamma_h
#define G4Gamma_h 1

#include "globals.hh"
#include "G4ios.hh"
#include "G4VBoson.hh"

// ######################################################################
// ###                           GAMMA                                ###
// ######################################################################

class G4Gamma : public G4VBoson
{
 private:
   static G4Gamma theGamma;
   static G4double  theGammaLengthCut;
   static G4double* theGammaKineticEnergyCuts;
   
   //-------- the followings are used privately in G4Gamma ----
 private:
    typedef G4LossTable G4CrossSectionTable;
    void BuildAbsorptionLengthVector(
                              const G4Material* aMaterial,
			      const G4CrossSectionTable* aCrossSectionTable,
			      G4double       maxEnergy,     
			      G4double       aMass,
                              G4RangeVector* absorptionLengthVector 
			     );
    G4double ComputeCrossSection(
                              G4double AtomicNumber,
                              G4double KineticEnergy
                             ) const;

 //--------------for SetCuts----------------------------------------------
 protected:    
    G4double ComputeLoss(G4double AtomicNumber,G4double KineticEnergy) const
    {
      return ComputeCrossSection(AtomicNumber,KineticEnergy);
    };

    void BuildRangeVector(
                                  const G4Material* aMaterial,
				  const G4LossTable* aLossTable,
				  G4double       maxEnergy,     
				  G4double       aMass,
                                  G4RangeVector* rangeVector)
    {
        BuildAbsorptionLengthVector(aMaterial,
				    (const G4CrossSectionTable*)aLossTable,
                                    maxEnergy, aMass, rangeVector);
    }

    G4double ConvertCutToKineticEnergy(
                                 G4RangeVector* absorptionLengthVector
                                ) const;


 private: // hide conxtructor as private
   G4Gamma(
       const G4String&     aName,        G4double            mass,
       G4double            width,        G4double            charge,   
       G4int               iSpin,        G4int               iParity,    
       G4int               iConjugation, G4int               iIsospin,   
       G4int               iIsospin3,    G4int               gParity,
       const G4String&     pType,        G4int               lepton,      
       G4int               baryon,       G4int               encoding,
       G4bool              stable,       G4double            lifetime,
       G4DecayTable        *decaytable
   );

 public:
   virtual ~G4Gamma(){}

   static G4Gamma* GammaDefinition();
   static G4Gamma* Gamma();
   static G4double  GetCuts() {return theGammaLengthCut;}   
   static G4double* GetCutsInEnergy() {return theGammaKineticEnergyCuts;};

   virtual void SetCuts(G4double aCut); 
};

inline void G4Gamma::SetCuts(G4double aCut)
{
  CalcEnergyCuts(aCut);
  theGammaLengthCut = theCutInMaxInteractionLength;  
  theGammaKineticEnergyCuts = theKineticEnergyCuts;
  
}

inline G4Gamma* G4Gamma::Gamma()
{ return &theGamma; }

#endif