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//
// G4RepleteEofM
//
// Class description:
//
// This is the right-hand side of equation of motion in a combined
// field, including: magnetic, electric, gravity, and gradient B field,
// as well as spin tracking.

// Author: Peter Gumplinger (TRIUMF), 08.04.2013
// -------------------------------------------------------------------
#ifndef G4EOFM_HH
#define G4EOFM_HH

#include "G4ChargeState.hh"
#include "G4EquationOfMotion.hh"

class G4Field;

/**
 * @brief G4RepleteEofM is the right-hand side of equation of motion in a
 * combined field, including: magnetic, electric, gravity, and gradient
 * B field, as well as spin tracking.
 */

class G4RepleteEofM : public G4EquationOfMotion
{
  public:

    /**
     * Constructor for G4EquationOfMotion.
     *  @param[in] field Pointer to the field.
     *  @param[in] nvar The number of integration variables.
     */
    G4RepleteEofM(G4Field* field, G4int nvar = 8);

    /**
     * Default Destructor.
     */
    ~G4RepleteEofM() override = default;

    /**
     * Sets the charge, momentum and mass of the current particle.
     * Used to set the equation's coefficients.
     *  @param[in] particleCharge Magnetic charge and moments in e+ units.
     *  @param[in] MomentumXc Particle momentum.
     *  @param[in] mass Particle mass.
     */
    void SetChargeMomentumMass(G4ChargeState particleCharge, // in e+ units
                               G4double MomentumXc,
                               G4double mass) override;

    /**
     * Calculates the value of the derivative, given the value of the field.
     *  @param[in] y Coefficients array.
     *  @param[in] Field Field value.
     *  @param[out] dydx Derivatives array.
     */
    void EvaluateRhsGivenB(const G4double y[],
                           const G4double Field[],
                                 G4double dydx[] ) const override;

    /**
     * Setter and getter for the magnetic anomaly.
     */
    inline void SetAnomaly(G4double a) { anomaly = a; }
    inline G4double GetAnomaly() const { return anomaly; }

    /**
     * Modifiers.
     */
    inline void SetBField() { fBfield = true; }
    inline void SetEField() { fEfield = true; }
    inline void SetgradB()  { fgradB  = true; }
    inline void SetSpin()   { fSpin   = true; }

  private:

    G4int fNvar = 0;

    G4bool fBfield=false, fEfield=false,
           fGfield=false, fgradB=false, fSpin=false;

    G4double charge=0.0, mass=0.0, magMoment=0.0, spin=0.0;

    G4double ElectroMagCof=0.0;

    G4double omegac=0.0, anomaly=0.0;
    G4double beta=0.0, gamma=0.0;
};

#endif