BDSFieldEM.hh

/* 
Beam Delivery Simulation (BDSIM) Copyright (C) Royal Holloway, 
University of London 2001 - 2023.
 
This file is part of BDSIM.
 
BDSIM is free software: you can redistribute it and/or modify 
it under the terms of the GNU General Public License as published 
by the Free Software Foundation version 3 of the License.
 
BDSIM is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with BDSIM.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef BDSFIELDEM_H
#define BDSFIELDEM_H
 
#include "globals.hh" // geant4 types / globals
#include "G4ElectroMagneticField.hh"
#include "G4ThreeVector.hh"
#include "G4Transform3D.hh"
 
#include <utility>
 
class BDSModulator;
 
class BDSFieldEM: public G4ElectroMagneticField
{
public:
  BDSFieldEM();
  explicit BDSFieldEM(G4Transform3D transformIn);
  virtual ~BDSFieldEM(){;}
 
  virtual std::pair<G4ThreeVector,G4ThreeVector> GetField(const G4ThreeVector& position,
                                                          const G4double       t = 0) const = 0;
  
  virtual G4bool TimeVarying() const {return false;}
  
  virtual void GetFieldValue(const G4double point[4],
                             G4double* field) const;
 
  virtual std::pair<G4ThreeVector,G4ThreeVector> GetFieldTransformed(const G4ThreeVector& position,
                                                                     const G4double       t) const;
 
  virtual void SetTransform(const G4Transform3D& transformIn);
 
  virtual G4bool DoesFieldChangeEnergy() const {return true;}
  
  void SetModulator(BDSModulator* modulatorIn) {modulator = modulatorIn;}
 
  inline G4bool FiniteStrength() const {return finiteStrength;}
  
protected:
  G4bool finiteStrength; 
  
  G4Transform3D transform;
  
  G4bool transformIsNotIdentity; 
  BDSModulator* modulator; 
 
private:
  G4Transform3D inverseTransform;
};
 
#endif