// -------------------------------------------------------------------------
// -----                      CbmFieldMap header file                  -----
// -----          Created 12/01/04  by M. Al/Turany (CbmField.h)       -----
// -----                Redesign 13/02/06  by V. Friese                -----
// -------------------------------------------------------------------------


/** CbmFieldMap.h
 ** @author M.Al/Turany <m.al-turany@gsi.de>
 ** @author V.Friese <v.friese@gsi.de>
 ** @since 12.01.2004
 ** @version1.0
 **
 ** Magnetic field map on a 3-D grid.
 ** Field values are hold and returned in kG.
 **/


#ifndef CBMFIELDMAP_H
#define CBMFIELDMAP_H 1


#include "FairField.h"

class TArrayF;
class CbmFieldMapCreator;
class CbmFieldMapData;
class CbmFieldPar;


class CbmFieldMap : public FairField {


public:


  /** Default constructor **/
  CbmFieldMap();


  /** Standard constructor
   ** @param name       Name of field map
   ** @param fileType   R = ROOT file, A = ASCII
   **/
  CbmFieldMap(const char* mapName, const char* fileType = "R");


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


  /** Constructor from CbmFieldMapCreator **/
  CbmFieldMap(CbmFieldMapCreator* creator);


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


  /** Initialisation (read map from file) **/
  virtual void Init();


  /** Get the field components at a certain point 
   ** @param x,y,z     Point coordinates (global) [cm]
   ** @value Bx,By,Bz  Field components [kG]
   **/
  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);


  /** Determine whether a point is inside the field map
   ** @param x,y,z              Point coordinates (global) [cm]
   ** @param ix,iy,iz (return)  Grid cell
   ** @param dx,dy,dz (return)  Distance from grid point [cm] if inside
   ** @value kTRUE if inside map, else kFALSE
   **/
  virtual Bool_t IsInside(Double_t x, Double_t y, Double_t z,
			  Int_t& ix, Int_t& iy, Int_t& iz,
			  Double_t& dx, Double_t& dy, Double_t& dz);

 
  /** 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; }


  /** Accessors to field parameters in local coordinate system **/
  Double_t GetXmin()  const { return fXmin; } 
  Double_t GetYmin()  const { return fYmin; }
  Double_t GetZmin()  const { return fZmin; }
  Double_t GetXmax()  const { return fXmax; }  
  Double_t GetYmax()  const { return fYmax; }
  Double_t GetZmax()  const { return fZmax; }
  Double_t GetXstep() const { return fXstep; }  
  Double_t GetYstep() const { return fYstep; }
  Double_t GetZstep() const { return fZstep; }
  Int_t    GetNx()    const { return fNx; }
  Int_t    GetNy()    const { return fNy; }
  Int_t    GetNz()    const { return fNz; }


  /** Accessor to field centre position in global system **/
  Double_t GetPositionX() const { return fPosX; }
  Double_t GetPositionY() const { return fPosY; }
  Double_t GetPositionZ() const { return fPosZ; }


  /** Accessor to global scaling factor  **/
  Double_t GetScale() const { return fScale; }


  /** Accessors to the field value arrays **/
  TArrayF* GetBx() const { return fBx; }
  TArrayF* GetBy() const { return fBy; }
  TArrayF* GetBz() const { return fBz; }


  /** Accessor to field map file **/
  const char* GetFileName() { return fFileName.Data(); }


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

	
 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);


  /** Set field parameters and data **/
  void SetField(const CbmFieldMapData* data);


  /** Get field values by interpolation of the grid.
   ** @param dx,dy,dz  Relative distance from grid point [cell units]
   **/
  Double_t Interpolate(Double_t dx, Double_t dy, Double_t dz); 


  /** Map file name **/
  TString fFileName;


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


  /** Field centre position in global coordinates  **/
  Double_t fPosX, fPosY, fPosZ; 


  /** Field limits in local coordinate system **/
  Double_t fXmin, fXmax, fXstep;
  Double_t fYmin, fYmax, fYstep;
  Double_t fZmin, fZmax, fZstep;


  /** Number of grid points  **/
  Int_t fNx, fNy, fNz;


  /** Arrays with the field values  **/
  TArrayF* fBx;
  TArrayF* fBy;
  TArrayF* fBz;


  /** Variables for temporary storage 
   ** Used in the very frequently called method GetFieldValue  **/
  Double_t fHa[2][2][2];            //! Field at corners of a grid cell
  Double_t fHb[2][2];               //! Interpolated field (2-dim)
  Double_t fHc[2];                  //! Interpolated field (1-dim)

 private:

  CbmFieldMap(const CbmFieldMap&);
  CbmFieldMap& operator=(const CbmFieldMap&);

  ClassDef(CbmFieldMap,1) 

};


#endif