#ifndef STNTUPLE_TStnSiIsect
#define STNTUPLE_TStnSiIsect
//-----------------------------------------------------------------------------
//  This is a definition of the intersection of a track with a silicon
//  half ladder.
//  These objects are contained in a TClonesArray in the
//  TSiIsectBlock.
//  If you are looping over tracks, then you can use the
//  correspondance object, TStnTrackLinkBlock, to get access to all
//  intersections for a given track.  You also have immediate access
//  to all silicon hits for this track for comparison.
//  To get all the intersections with a certain halfladder, use the ...
//
//  Author:    Aaron Dominguez (CDF/LBNL)
//  Date:      June 19 2001
//-----------------------------------------------------------------------------
#include "TObject.h"
#include "TVector3.h"
#include "Stntuple/obj/TStnSiDigiCode.hh"
#include "Stntuple/base/TBitset.hh"

class TStnSiIsect: public TObject {

public:
//------------------------------------------------------------------------------
//  data members
//------------------------------------------------------------------------------
  TVector3 fGlobal;         // Position of intersection in global CDF coordinates
  TVector3 fDirection;      // Direction of track at intersection point

  Float_t fStripNumPhi;     // Position in intersection strip units
  Float_t fStripNumZ;       // Position in intersection strip units

  Float_t fLocY;            // Position in cm in local y-coordinate
  Float_t fLocZ;            // Position in cm in local z-coordinate

  TStnSiDigiCode fDigiCode; // The (repacked) SiDigiCode of the detector element

  TBitset fActiveRegion;    // Did the track pass thru the active
			    // region(s) of the detector element?
                            // Bit   =1 -> Yes
                            // ---   ------------------------------
                            // 0     Phi area of side 0
                            // 1     Z area of side 0
                            // 2     Z area of side 1
                            // 4     Phi area of side 1

  Int_t fCdfTrackId;   //! The NON-STREAMED CdfTrack->id() for reference

//------------------------------------------------------------------------------
//  functions
//------------------------------------------------------------------------------
					// ****** constructors and destructor
  TStnSiIsect();
  virtual ~TStnSiIsect();
					// ****** accessors
  TVector3* Global()         {return &fGlobal;}
  TVector3* Direction()      {return &fDirection;}
  Float_t   StripNumPhi()    {return fStripNumPhi;}
  Float_t   StripNumZ()      {return fStripNumZ;}
  Float_t   LocY()           {return fLocY;}
  Float_t   LocZ()           {return fLocZ;}
  TStnSiDigiCode* DigiCode() {return &fDigiCode;}
  TBitset*  ActiveRegion()   {return &fActiveRegion;}

  void Print(Option_t* option = "") const;

  ClassDef(TStnSiIsect,4)
};

#endif