G4bool EstimateIntersectionPoint(const G4FieldTrack &curveStartPointTangent, const G4FieldTrack &curveEndPointTangent, const G4ThreeVector &trialPoint, G4FieldTrack &intersectPointTangent, G4bool &recalculatedEndPoint, G4double &fPreviousSafety, G4ThreeVector &fPreviousSftOrigin)