include/DDG4/Geant4Field.h

0001 //==========================================================================
0002 //  AIDA Detector description implementation
0003 //--------------------------------------------------------------------------
0004 // Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
0005 // All rights reserved.
0006 //
0007 // For the licensing terms see $DD4hepINSTALL/LICENSE.
0008 // For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
0009 //
0010 // Author     : M.Frank
0011 //
0012 //==========================================================================
0013
0014 #ifndef DDG4_GEANT4FIELD_H
0015 #define DDG4_GEANT4FIELD_H
0016
0017 // Framework include files
0018 #include <DD4hep/Detector.h>
0019
0020 // Geant 4 include files
0021 #include <G4ElectroMagneticField.hh>
0022 #include <G4MagneticField.hh>
0023
0024 /// Namespace for the AIDA detector description toolkit
0025 namespace dd4hep {
0026
0027   /// Namespace for the Geant4 based simulation part of the AIDA detector description toolkit
0028   namespace sim {
0029
0030     // Forward declarations
0031     class Geant4Field;
0032
0033     /// Mediator class to allow Geant4 accessing magnetic fields defined in dd4hep
0034     /**
0035      *  \author  M.Frank
0036      *  \version 1.0
0037      *  \ingroup DD4HEP_SIMULATION
0038      */
0039     class Geant4Field : public G4MagneticField {
0040     protected:
0041       /// Reference to the detector description field
0042       OverlayedField m_field;
0043
0044     public:
0045       /// Constructor. The sensitive detector element is identified by the detector name
0046       Geant4Field(OverlayedField field) : m_field(field) {   }
0047       /// Standard destructor
0048       virtual ~Geant4Field() {    }
0049       /// Access field values at a given point
0050       virtual void GetFieldValue(const double pos[4], double *arr) const;
0051       /// Does field change energy ?
0052       virtual G4bool DoesFieldChangeEnergy() const;
0053     };
0054
0055   }    // End namespace sim
0056 }      // End namespace dd4hep
0057 #endif // DDG4_GEANT4FIELD_H