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// $Id: G4FieldManager.cc 68055 2013-03-13 14:43:28Z gcosmo $
//
// -------------------------------------------------------------------

#include "G4FieldManager.hh"
#include "G4Field.hh"
#include "G4MagneticField.hh"
#include "G4ChordFinder.hh"
#include "G4FieldManagerStore.hh"

G4FieldManager::G4FieldManager(G4Field       *detectorField, 
			       G4ChordFinder *pChordFinder, 
			       G4bool        fieldChangesEnergy
			      )
   : fDetectorField(detectorField), 
     fChordFinder(pChordFinder), 
     fAllocatedChordFinder(false),
     fEpsilonMinDefault(5.0e-5), 
     fEpsilonMaxDefault(0.001),
     fDefault_Delta_One_Step_Value(0.01),    // mm
     fDefault_Delta_Intersection_Val(0.001), // mm
     fEpsilonMin( fEpsilonMinDefault ),
     fEpsilonMax( fEpsilonMaxDefault)
{ 
   fDelta_One_Step_Value= fDefault_Delta_One_Step_Value;
   fDelta_Intersection_Val= fDefault_Delta_Intersection_Val;
   if ( detectorField )
     fFieldChangesEnergy= detectorField->DoesFieldChangeEnergy();
   else
     fFieldChangesEnergy= fieldChangesEnergy;

   // Add to store
   G4FieldManagerStore::Register(this);
}

G4FieldManager::G4FieldManager(G4MagneticField *detectorField)
   : fDetectorField(detectorField), fAllocatedChordFinder(true),
     fEpsilonMinDefault(5.0e-5), 
     fEpsilonMaxDefault(0.001),
     fFieldChangesEnergy(false), 
     fDefault_Delta_One_Step_Value(0.01),    // mm
     fDefault_Delta_Intersection_Val(0.001), // mm
     fEpsilonMin( fEpsilonMinDefault ),
     fEpsilonMax( fEpsilonMaxDefault)
{
   fChordFinder= new G4ChordFinder( detectorField );
   fDelta_One_Step_Value= fDefault_Delta_One_Step_Value;
   fDelta_Intersection_Val= fDefault_Delta_Intersection_Val;
   // Add to store
   G4FieldManagerStore::Register(this);
}

G4FieldManager* G4FieldManager::Clone() const
{
    G4Field* aField = 0;
    G4FieldManager* aFM = 0;
    G4ChordFinder* aCF = 0;
    try {
        if ( this->fDetectorField )
            aField = this->fDetectorField->Clone();

        //Create a new field manager, note that we do not set any chordfinder now.
        aFM = new G4FieldManager( aField , 0 , this->fFieldChangesEnergy );

        //Check if orignally we have the fAllocatedChordFinder variable set, in case, call chord
        //constructor
        if ( this->fAllocatedChordFinder )
        {
            aFM->CreateChordFinder( dynamic_cast<G4MagneticField*>(aField) );
        }
        else
        {
            //Chord was specified by user, should we clone?
            //TODO: For the moment copy pointer, to be understood if cloning of ChordFinder is needed
            aCF = this->fChordFinder;/*->Clone*/
            aFM->fChordFinder = aCF;
        }
        //Copy values of other variables
        aFM->fEpsilonMax = this->fEpsilonMax;
        aFM->fEpsilonMin = this->fEpsilonMin;
        aFM->fDefault_Delta_Intersection_Val = this->fDefault_Delta_Intersection_Val;
        aFM->fDefault_Delta_One_Step_Value = this->fDefault_Delta_One_Step_Value;
        aFM->fDelta_Intersection_Val = this->fDelta_Intersection_Val;
        aFM->fDelta_One_Step_Value = this->fDelta_One_Step_Value;
        //TODO: Should we really add to the store the cloned FM? Who will use this?
    }
    catch ( ... )
    {
        //Failed creating clone: probably user did not implement Clone method
        //in derived classes?
        //Perform clean-up after ourselves...
        delete aField;
        delete aFM;
        delete aCF;
        throw;
    }
    return aFM;
}

void G4FieldManager::ConfigureForTrack( const G4Track * ) 
{
   // Default is to do nothing!
   ;
}

G4FieldManager::~G4FieldManager()
{
   if( fAllocatedChordFinder ){
      delete fChordFinder;
   }
   G4FieldManagerStore::DeRegister(this);
}

void
G4FieldManager::CreateChordFinder(G4MagneticField *detectorMagField)
{
   if ( fAllocatedChordFinder )
      delete fChordFinder;
   fChordFinder= new G4ChordFinder( detectorMagField );
   fAllocatedChordFinder= true;
}

G4bool G4FieldManager::SetDetectorField(G4Field *pDetectorField)
{
   fDetectorField= pDetectorField;

   if ( pDetectorField )
     fFieldChangesEnergy= pDetectorField->DoesFieldChangeEnergy();
   else
     fFieldChangesEnergy= false;   //  No field 

   return false;
}