include/Geant4/G4TCachedMagneticField.hh

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0026
0027 #ifndef TCACHED_MAGNETIC_FIELD_DEF
0028 #define TCACHED_MAGNETIC_FIELD_DEF
0029
0030 #include "G4Types.hh"
0031 #include "G4ThreeVector.hh"
0032 #include "G4MagneticField.hh"
0033
0034 template <class T_Field>
0035 class G4TCachedMagneticField : public G4MagneticField
0036 {
0037  public:  // with description
0038   G4TCachedMagneticField(T_Field* pTField, G4double distance)
0039     : G4MagneticField()
0040     , fLastLocation(DBL_MAX, DBL_MAX, DBL_MAX)
0041     , fLastValue(DBL_MAX, DBL_MAX, DBL_MAX)
0042     , fCountCalls(0)
0043     , fCountEvaluations(0)
0044   {
0045     fpMagneticField = pTField;
0046     fDistanceConst  = distance;
0047
0048     // G4cout << " Cached-B-Field constructor> Distance = " << distance <<
0049     // G4endl;
0050     this->ClearCounts();
0051   }
0052
0053   G4TCachedMagneticField(const G4TCachedMagneticField<T_Field>& rightCMF)
0054   {
0055     fpMagneticField = rightCMF.fpMagneticField;
0056     fDistanceConst  = rightCMF.fDistanceConst;
0057     fLastLocation   = rightCMF.fLastLocation;
0058     fLastValue      = rightCMF.fLastValue;
0059     this->ClearCounts();
0060   }
0061
0062   G4TCachedMagneticField* Clone() const
0063   {
0064     G4cout << "Clone is called" << G4endl;
0065     // Cannot use copy constructor: I need to clone the associated magnetif
0066     // field
0067     T_Field* aF = this->fpMagneticField->T_Field::Clone();
0068     G4TCachedMagneticField* cloned =
0069       new G4TCachedMagneticField(aF, this->fDistanceConst);
0070     cloned->fLastLocation = this->fLastLocation;
0071     cloned->fLastValue    = this->fLastValue;
0072     return cloned;
0073   }
0074
0075   virtual ~G4TCachedMagneticField() { ; }
0076   // Constructor and destructor. No actions.
0077
0078   void ReportStatistics()
0079   {
0080     G4cout << " Cached field: " << G4endl
0081            << "   Number of calls:        " << fCountCalls << G4endl
0082            << "   Number of evaluations : " << fCountEvaluations << G4endl;
0083   }
0084
0085   virtual void GetFieldValue(const G4double Point[4], G4double* Bfield) const
0086   {
0087     G4ThreeVector newLocation(Point[0], Point[1], Point[2]);
0088
0089     G4double distSq = (newLocation - fLastLocation).mag2();
0090     fCountCalls++;
0091     if(distSq < fDistanceConst * fDistanceConst)
0092     {
0093       Bfield[0] = fLastValue.x();
0094       Bfield[1] = fLastValue.y();
0095       Bfield[2] = fLastValue.z();
0096     }
0097     else
0098     {
0099       // G4CachedMagneticField* thisNonC=
0100       // const_cast<G4CachedMagneticField*>(this);
0101       fpMagneticField->T_Field::GetFieldValue(Point, Bfield);
0102       // G4cout << " Evaluating. " << G4endl;
0103       fCountEvaluations++;
0104       // thisNonC->
0105       fLastLocation = G4ThreeVector(Point[0], Point[1], Point[2]);
0106       // thisNonC->
0107       fLastValue = G4ThreeVector(Bfield[0], Bfield[1], Bfield[2]);
0108     }
0109   }
0110
0111   G4double GetConstDistance() const { return fDistanceConst; }
0112   void SetConstDistance(G4double dist) { fDistanceConst = dist; }
0113
0114   G4int GetCountCalls() const { return fCountCalls; }
0115   G4int GetCountEvaluations() const { return fCountEvaluations; }
0116   void ClearCounts()
0117   {
0118     fCountCalls       = 0;
0119     fCountEvaluations = 0;
0120   }
0121
0122   G4TCachedMagneticField& operator=(const G4TCachedMagneticField& right)
0123   {
0124     if(&right == this)
0125       return *this;
0126
0127     fpMagneticField = right.fpMagneticField;
0128
0129     fDistanceConst= right.fDistanceConst;
0130     fLastLocation = right.fLastLocation;
0131     fLastValue = right.fLastValue;
0132
0133     fCountCalls = 0;
0134     fCountEvaluations = 0;
0135
0136     return *this;
0137  }
0138
0139  private:
0140   T_Field* fpMagneticField;
0141   // When the field is evaluated within this distance it will not change
0142   G4double fDistanceConst;
0143   // Caching state
0144   mutable G4ThreeVector fLastLocation;
0145   mutable G4ThreeVector fLastValue;
0146
0147  protected:
0148   mutable G4int fCountCalls, fCountEvaluations;
0149 };
0150
0151 #endif /* TCACHED_MAGNETIC_FIELD_DEF */