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//
// -------------------------------------------------------------------
//
// GEANT4 Class header file
//
//
// File name:  G4RiGeAngularGenerator
//
// Authors:       Gerardo Depaola & Ricardo Pacheco
// 
// Creation date: 29 October 2024
//
// -------------------------------------------------------------------
//

#ifndef G4RiGeAngularGenerator_h
#define G4RiGeAngularGenerator_h 1

#include "G4ios.hh"
#include "globals.hh"
#include "G4VEmAngularDistribution.hh"
#include "G4LorentzVector.hh"

class G4RiGeAngularGenerator : public G4VEmAngularDistribution
{

public:

  G4RiGeAngularGenerator();

  ~G4RiGeAngularGenerator() override = default;

  G4ThreeVector& SampleDirection(const G4DynamicParticle* dp,
                                 G4double gEnergy, G4int Z,
                                 const G4Material* mat = nullptr) override;

  void Sample5DPairDirections(const G4DynamicParticle* dp,
			      G4ThreeVector& dirElectron,
			      G4ThreeVector& dirPositron,
			      const G4double gEnergy, const G4double q2,
			      const G4double gMomentum,
			      G4double muFinalMomentum,
			      G4double muFinalEnergy,
			      const G4double* randNumbs,
			      const G4double* W);

  void PhiRotation(G4ThreeVector& dir, G4double phi);

  G4LorentzVector eDP2(G4double x1, G4double x2, G4double x3, G4double x4, G4double x5);

  G4LorentzVector pDP2(G4double x3, const G4LorentzVector& x6);

  void PrintGeneratorInformation() const override;

  // hide assignment operator 
  G4RiGeAngularGenerator& operator=(const G4RiGeAngularGenerator& right) = delete;
  G4RiGeAngularGenerator(const G4RiGeAngularGenerator&) = delete;

private:

  G4double SampleCosTheta(G4double primKinEnergy, G4double gEnergy, G4double mass);

};

#endif