G4CachedMagneticField.hh

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//
// G4CachedMagneticField
//
// Class description:
//
// Caches Magnetic Field value, for field whose evaluation is expensive.
 
// Author: J.Apostolakis, 20 July 2009.
// --------------------------------------------------------------------
#ifndef G4CACHED_MAGNETIC_FIELD_HH
#define G4CACHED_MAGNETIC_FIELD_HH
 
#include "G4Types.hh"
#include "G4ThreeVector.hh"
#include "G4MagneticField.hh"
 
class G4CachedMagneticField : public G4MagneticField
{
  public:
 
    G4CachedMagneticField(G4MagneticField*, G4double distanceConst);
    ~G4CachedMagneticField() override;
      // Constructor and destructor. No actions.
 
    G4CachedMagneticField(const G4CachedMagneticField& r);
    G4CachedMagneticField& operator = (const G4CachedMagneticField& p);
      // Copy constructor & assignment operator.
 
    void GetFieldValue( const G4double Point[4],
                              G4double* Bfield ) const override;
     
    G4double GetConstDistance() const { return fDistanceConst; } 
    void SetConstDistance( G4double dist ) { fDistanceConst= dist;}
 
    G4int GetCountCalls() const { return fCountCalls; }
    G4int GetCountEvaluations() const { return fCountEvaluations; } 
    void ClearCounts() { fCountCalls = 0; fCountEvaluations=0; }
    void ReportStatistics();
    
    G4Field* Clone() const override;
 
  protected:
 
    mutable G4int fCountCalls = 0, fCountEvaluations = 0;  
 
  private:
 
    G4MagneticField* fpMagneticField = nullptr;
    G4double fDistanceConst;
      // When the field is evaluated within this distance it will not change
 
    // Caching state
    //
    mutable G4ThreeVector fLastLocation;
    mutable G4ThreeVector fLastValue;
};
 
#endif /* G4CACHED_MAGNETIC_FIELD_DEF */