include/Geant4/G4CachedMagneticField.hh

0001 //
0002 // ********************************************************************
0003 // * License and Disclaimer                                           *
0004 // *                                                                  *
0005 // * The  Geant4 software  is  copyright of the Copyright Holders  of *
0006 // * the Geant4 Collaboration.  It is provided  under  the terms  and *
0007 // * conditions of the Geant4 Software License,  included in the file *
0008 // * LICENSE and available at  http://cern.ch/geant4/license .  These *
0009 // * include a list of copyright holders.                             *
0010 // *                                                                  *
0011 // * Neither the authors of this software system, nor their employing *
0012 // * institutes,nor the agencies providing financial support for this *
0013 // * work  make  any representation or  warranty, express or implied, *
0014 // * regarding  this  software system or assume any liability for its *
0015 // * use.  Please see the license in the file  LICENSE  and URL above *
0016 // * for the full disclaimer and the limitation of liability.         *
0017 // *                                                                  *
0018 // * This  code  implementation is the result of  the  scientific and *
0019 // * technical work of the GEANT4 collaboration.                      *
0020 // * By using,  copying,  modifying or  distributing the software (or *
0021 // * any work based  on the software)  you  agree  to acknowledge its *
0022 // * use  in  resulting  scientific  publications,  and indicate your *
0023 // * acceptance of all terms of the Geant4 Software license.          *
0024 // ********************************************************************
0025 //
0026 // G4CachedMagneticField
0027 //
0028 // Class description:
0029 //
0030 // Caches Magnetic Field value, for field whose evaluation is expensive.
0031
0032 // Author: J.Apostolakis, 20 July 2009.
0033 // --------------------------------------------------------------------
0034 #ifndef G4CACHED_MAGNETIC_FIELD_HH
0035 #define G4CACHED_MAGNETIC_FIELD_HH
0036
0037 #include "G4Types.hh"
0038 #include "G4ThreeVector.hh"
0039 #include "G4MagneticField.hh"
0040
0041 class G4CachedMagneticField : public G4MagneticField
0042 {
0043   public:
0044
0045     G4CachedMagneticField(G4MagneticField*, G4double distanceConst);
0046     ~G4CachedMagneticField() override;
0047       // Constructor and destructor. No actions.
0048
0049     G4CachedMagneticField(const G4CachedMagneticField& r);
0050     G4CachedMagneticField& operator = (const G4CachedMagneticField& p);
0051       // Copy constructor & assignment operator.
0052
0053     void GetFieldValue( const G4double Point[4],
0054                               G4double* Bfield ) const override;
0055
0056     G4double GetConstDistance() const { return fDistanceConst; }
0057     void SetConstDistance( G4double dist ) { fDistanceConst= dist;}
0058
0059     G4int GetCountCalls() const { return fCountCalls; }
0060     G4int GetCountEvaluations() const { return fCountEvaluations; }
0061     void ClearCounts() { fCountCalls = 0; fCountEvaluations=0; }
0062     void ReportStatistics();
0063
0064     G4Field* Clone() const override;
0065
0066   protected:
0067
0068     mutable G4int fCountCalls = 0, fCountEvaluations = 0;
0069
0070   private:
0071
0072     G4MagneticField* fpMagneticField = nullptr;
0073     G4double fDistanceConst;
0074       // When the field is evaluated within this distance it will not change
0075
0076     // Caching state
0077     //
0078     mutable G4ThreeVector fLastLocation;
0079     mutable G4ThreeVector fLastValue;
0080 };
0081
0082 #endif /* G4CACHED_MAGNETIC_FIELD_DEF */