// -------------------------------------------------------------------------
// -----                    CbmFieldConst header file                  -----
// -----                Created 12/01/04  by M. Al-Turany              -----
// -----                Redesign 13/02/06  by V. Friese                -----
// -------------------------------------------------------------------------


/** CbmFieldConst.h
 ** @author M.Al-Turany <m.al/turany@gsi.de>
 ** @author V.Friese <v.friese@gsi.de>
 ** @since 12.01.2004
 ** @version1.0
 **
 ** A constant (homogeneous) magnetic field
 **/


#ifndef CBMFIELDCONST_H
#define CBMFIELDCONST_H 1


#include "CbmField.h"


class CbmFieldPar;


class CbmFieldConst : public CbmField
{

 public:    

  /** Default constructor **/
  CbmFieldConst();


  /** Standard constructor 
   ** @param name   Object name
   ** @param xMin,xMax   x region of field (global coordinates)
   ** @param yMin,yMax   y region of field (global coordinates)
   ** @param zMin,zMax   z region of field (global coordinates)
   ** @param bX,bY,bZ    Field values [kG]
   **/
  CbmFieldConst(const char* name, Double_t xMin, Double_t xMax,
		Double_t yMin, Double_t yMax, Double_t zMin,
		Double_t zMax, Double_t bX, Double_t bY, Double_t bZ);


  /** Constructor from CbmFieldPar **/
  CbmFieldConst(CbmFieldPar* fieldPar);


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


  /** Set the field region
   ** @param xMin,xMax   x region of field (global coordinates)
   ** @param yMin,yMax   y region of field (global coordinates)
   ** @param zMin,zMax   z region of field (global coordinates)
   **/
  void SetFieldRegion(Double_t xMin, Double_t xMax, Double_t yMin, 
		      Double_t yMax, Double_t zMin, Double_t zMax);


  /** Set the field values
   ** @param bX,bY,bZ    Field values [kG]
   **/
  void SetField(Double_t bX, Double_t bY, Double_t bZ);
  

  /** Get components of field at a given point 
   ** @param x,y,z   Point coordinates [cm]
   **/
  virtual Double_t GetBx(Double_t x, Double_t y, Double_t z);
  virtual Double_t GetBy(Double_t x, Double_t y, Double_t z);
  virtual Double_t GetBz(Double_t x, Double_t y, Double_t z);


  /** Accessors to field region **/
  Double_t GetXmin() const { return fXmin; }
  Double_t GetXmax() const { return fXmax; }
  Double_t GetYmin() const { return fYmin; }
  Double_t GetYmax() const { return fYmax; }
  Double_t GetZmin() const { return fZmin; }
  Double_t GetZmax() const { return fZmax; }


  /** Accessors to field values **/
  Double_t GetBx() const { return fBx; }
  Double_t GetBy() const { return fBy; }
  Double_t GetBz() const { return fBz; }


  /** Screen output **/
  virtual void Print();


 private:

  /** Limits of the field region **/
  Double_t fXmin;   
  Double_t fXmax;
  Double_t fYmin;
  Double_t fYmax;
  Double_t fZmin;
  Double_t fZmax;
  
  /** Field components inside the field region **/
  Double_t fBx;
  Double_t fBy;
  Double_t fBz;

  ClassDef(CbmFieldConst, 1);

};


#endif