//
#ifndef G__TRKUTIL_H
#define G__TRKUTIL_H
//
#include <TVector3.h>
#include <TVectorD.h>
#include <TMatrixDSym.h>
#include <TRandom.h>
//
//
// Class test

class TrkUtil {
	//
	//
protected:
	Double_t fBz;							// Solenoid magnetic field
	//
	Int_t fGasSel;							// Gas selection: 0: He-Iso, 1: He, 2:Ar-Eth, 3: Ar
	Double_t fRmin;							// Lower		DCH radius
	Double_t fRmax;							// Higher	DCH radius
	Double_t fZmin;							// Lower		DCH z
	Double_t fZmax;							// Higher	DCH z
	//
	// Service routines
	//
	void SetB(Double_t Bz) { fBz = Bz; }
	TVectorD XPtoPar(TVector3 x, TVector3 p, Double_t Q);
	TVector3 ParToP(TVectorD Par);
	//
	// Conversion to ACTS parametrization
	//
	TVectorD ParToACTS(TVectorD Par);		// Parameter conversion
	TMatrixDSym CovToACTS(TVectorD Par, TMatrixDSym Cov);	// Covariance conversion
	//
	// Conversion to ILC parametrization
	//
	TVectorD ParToILC(TVectorD Par);		// Parameter conversion
	TMatrixDSym CovToILC(TMatrixDSym Cov);	// Covariance conversion
	//

public:
	//
	// Constructors
	TrkUtil();
	TrkUtil(Double_t Bz);
	// Destructor
	~TrkUtil();
	//
	// Overload methods to allow call without instantiating class
	//
	static Double_t cSpeed()
	{
		Double_t c = 2.99792458e8;	// speed of light m/sec
		//return TMath::C()*1.0e-9;	// Incompatible with root5
		return c*1.0e-9; 		// Reduced speed of light	
	}
	//
	// Service routines
	//
	static TVectorD XPtoPar(TVector3 x, TVector3 p, Double_t Q, Double_t Bz);
	static TVector3 ParToX(TVectorD Par);				// position of minimum distance from z axis
	static TVector3 ParToP(TVectorD Par, Double_t Bz);	// Get Momentum from track parameters
	static Double_t ParToQ(TVectorD Par);				// Get track charge
	//
	// Conversion from meters to mm
	//
	static TVectorD ParToMm(TVectorD Par);			// Parameter conversion
	static TMatrixDSym CovToMm(TMatrixDSym Cov);	// Covariance conversion
	//
	// Cluster counting in gas
	//
	void SetBfield(Double_t Bz) { fBz = Bz; }
	// Define gas volume (units = meters) 
	void SetDchBoundaries(Double_t Rmin, Double_t Rmax, Double_t Zmin, Double_t Zmax);
	// Gas mixture selection
	void SetGasMix(Int_t Opt);
	// Get number of ionization clusters
	Bool_t IonClusters(Double_t &Ncl, Double_t mass, TVectorD Par);
	Double_t Nclusters(Double_t bgam);	// mean clusters/meter vs beta*gamma
	static Double_t Nclusters(Double_t bgam, Int_t Opt);	// mean clusters/meter vs beta*gamma
	Double_t funcNcl(Double_t *xp, Double_t *par);
	Double_t TrkLen(TVectorD Par);					// Track length inside chamber
};

#endif