// -------------------------------------------------------------------------
// -----                      R3BFieldMap header file                  -----
// -------------------------------------------------------------------------


/** R3BFieldMap.h
 ** @since 12.01.2004
 ** @version1.0
 **
 ** Magnetic field map on a 3-D grid.
 ** Field values are hold and returned in kG.
 **/


#ifndef R3BFIELDMAP_H
#define R3BFIELDMAP_H 1


#include "FairField.h"
#include "TRotation.h"
#include "TVector3.h"

class TArrayI;
class TArrayF;
class R3BFieldPar;

class R3BFieldMap : public FairField {

public:
  /** Default constructor **/
  R3BFieldMap();
  /** Standard constructor
   ** @param name       Name of field map
   ** @param fileType   R = ROOT file, A = ASCII
   **/
  R3BFieldMap(const char* mapName, const char* fileType = "R");
  /** Constructor from R3BFieldPar **/
  R3BFieldMap(R3BFieldPar* fieldPar);
  R3BFieldMap(Int_t ftype,Bool_t verbosity=kFALSE);


  /** Destructor **/
  virtual ~R3BFieldMap();
  /** Initialisation (read map from file) **/
  virtual void Init();
  /** Write the field map to an ASCII file **/
  void WriteAsciiFile(const char* fileName);
  /** Write field map data to a ROOT file **/
  void WriteRootFile(const char* fileName, const char* mapName);
  /** Set the position of the field centre **/
  virtual void SetPosition(Double_t x, Double_t y, Double_t z);
  /** Set a global field scaling factor **/
  virtual void SetScale(Double_t factor) { fScale = factor; }
  /** Accessor to global scaling factor  **/
  Double_t GetScale() const { return fScale; }
  /** Screen output **/
  virtual void Print();
  /** Main GetField function */
  virtual void GetFieldValue(const Double_t point[3], Double_t* bField);

  void SetVerbose(Bool_t verbosity){ fVerbose = verbosity;}



 protected:
  /** Reset the field parameters and data **/
  void Reset();
  /** Read the field map from an ASCII file **/
  void ReadAsciiFile(const char* fileName);
  /** Read field map from a ROOT file **/	
  void ReadRootFile(const char* fileName, const char* mapName);

  Int_t GetLineForPosition(TVector3*  pos) const;
  Int_t GetPositionForLine(Int_t line, TVector3* pos) const;
  Int_t GetLinesArrayForPosition(TVector3* pos, TArrayI* lines);

  /** Map file name **/
  TString fFileName;
  /** Global scaling factor (w.r.t. map on file) **/
  Double_t fScale;             

  /** Local Variables **/
  Int_t stepsInX;
  Int_t stepsInY;
  Int_t stepsInZ;       //steps in the field map along each direction
  Double_t initialX;
  Double_t initialY;
  Double_t initialZ; //initial coordinates in field map
  Double_t gridStep;                     //distance between points in field map

  Double_t* Bxfield;                     //!field values obtained from field map
  Double_t* Byfield;                     //!
  Double_t* Bzfield;                     //!


  Int_t typeField;  // 0 for ALADIN field map,
                    // 1 for R3B map, 2 for other possib .
                    // 3 ALADIN inverted for back tracking

  TRotation* gRot;
  TVector3* gTrans;

  Bool_t fVerbose;

  ClassDef(R3BFieldMap,1)

};


#endif