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//
// class G4HelixMixedStepper
//
// Class description:
//
// G4HelixMixedStepper split the Method used for Integration in two:
//
// If Stepping Angle ( h / R_curve) < pi/3 : use Classical RK4Stepper
// Else use  HelixExplicitEuler Stepper
//
// History: 
// Derived from ExactHelicalStepper 18/05/07 
//
// -------------------------------------------------------------------

#ifndef G4HELIXMIXEDSTEPPER_HH
#define G4HELIXMIXEDSTEPPER_HH

#include "G4MagHelicalStepper.hh"


class G4HelixMixedStepper: public G4MagHelicalStepper
{

  public:  

  G4HelixMixedStepper(G4Mag_EqRhs *EqRhs);
  ~G4HelixMixedStepper();

   void Stepper( const G4double y[],
                  const G4double dydx[],
                        G4double h,
                        G4double yout[],
                        G4double yerr[]  );
      // Step 'integration' for step size 'h'
      // If SteppingAngle=h/R_curve<pi/3 uses RK4Stepper
      // Else Helix Fast Method 
      
  
    void DumbStepper( const G4double y[],
                            G4ThreeVector  Bfld,
                            G4double       h,
                            G4double       yout[]);
   G4double DistChord() const;
      // Estimate maximum distance of curved solution and chord ... 
  
   public:  // without description

    G4int IntegratorOrder() const { return 4; }
  
      // Mixed Integration RK4 for 'small' steps
        G4MagIntegratorStepper* fRK4Stepper;
   
   private:
    // Used for DistChord Calculation
    G4double         fLastStepSize;  // Length of last step
  
  
};

#endif /* G4HELIXMIXEDSTEPPER_HH */