// -------------------------------------------------------------------------
// -----                      CbmField header file                     -----
// -----                Created 06/01/04  by M. Al-Turany              -----
// -----                Redesign 13/02/06  by V. Friese                -----
// -----                Redesign 04/08/06  by M. Al-Turany               -----
// -------------------------------------------------------------------------


/** CbmField.h
 ** @author M.Al-Turany <m.al/turany@gsi.de>
 ** @author V.Friese <v.friese@gsi.de>
 ** @since 06.01.2004
 ** @version1.0
 **
 ** Abstract base class for magnetic fields in CBM 
 ** Concrete field must implement the pure virtual methods
 ** GetBx, GetBy and GetBz
 **
 ** Note: Field values should be returned in kG (thanks to GEANT3)
 **/


#ifndef CBMFIELD_H
#define CBMFIELD_H 1


#include "TNamed.h"
#include <iostream>

class CbmField : public TNamed 
{

public:    

  /** Default constructor **/
  CbmField();


  /** Constructor with name and title **/
  CbmField(const char* name, const char* title = "CBM Magnetic Field");


  /** Destructor **/
  virtual ~CbmField();


  /** Intialisation. E.g. read in the field map. If needed, to be
   ** implemented in the concrete class. 
   **/
  virtual void Init() { };

  /** Test whether field type is Constant **/
  Bool_t IsConst();


  /** Test whether field typ is Map **/
  Bool_t IsMap();


  /** Field type ( 0=constant, 1=map, 2=map sym2, 3 = map sym3 ) **/
  Int_t GetType() const { return fType; }


  /** Get x component of magnetic field [kG]
   ** @param x,y,z    Position [cm]
   **/
  virtual Double_t GetBx(Double_t x, Double_t y, Double_t z) {std::cout << "GetBx Should be implimented" << std::endl; return 0;}


  /** Get y component of magnetic field [kG]
   ** @param x,y,z    Position [cm]
   **/
  virtual Double_t GetBy(Double_t x, Double_t y, Double_t z) {std::cout << "GetBy Should be implimented" << std::endl; return 0;}


  /** Get z component of magnetic field [kG]
   ** @param x,y,z    Position [cm]
   **/
  virtual Double_t GetBz(Double_t x, Double_t y, Double_t z) {std::cout << "GetBz Should be implimented" << std::endl; return 0;}


  /** Get magnetic field. For use of GEANT3
   ** @param point            Coordinates [cm]
   ** @param bField (return)  Field components [kG] 
   **/
  virtual void GetFieldValue(const Double_t point[3], Double_t* bField);


  /** Screen output. To be implemented in the concrete class. **/
  virtual void Print() { };


 protected:

  /** Field type. 1 = constant field, 2 = field map. **/
  Int_t fType;
  

protected:


  ClassDef(CbmField,2);

};




#endif