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//
//
// $Id$
//
//
// class G4LineSection
//
// Class description:
//
// A utility class that calculates the distance of a point from a 
// line section.

// History:
// - Created. J. Apostolakis.
// --------------------------------------------------------------------

#ifndef G4LineSection_hh
#define G4LineSection_hh

#include "G4Types.hh" 
#include "G4ThreeVector.hh"

class G4LineSection
{
  public:  // with description

     inline G4LineSection( const G4ThreeVector& PntA, const G4ThreeVector& PntB );

     G4double Dist( G4ThreeVector OtherPnt ) const;

     inline G4double GetABdistanceSq() const;

     inline static G4double Distline( const G4ThreeVector& OtherPnt, 
                                      const G4ThreeVector& LinePntA, 
                                      const G4ThreeVector& LinePntB );
  private:

     G4ThreeVector   EndpointA;
     G4ThreeVector   VecAtoB;
     G4double fABdistanceSq ;
};

// Inline methods implementations

inline
G4LineSection::G4LineSection( const G4ThreeVector& PntA, 
			      const G4ThreeVector& PntB )
  : EndpointA(PntA), VecAtoB(PntB-PntA)
{ 
  fABdistanceSq = VecAtoB.mag2();  
}

inline
G4double G4LineSection::GetABdistanceSq() const
{
  return fABdistanceSq;
}

inline
G4double G4LineSection::Distline( const G4ThreeVector& OtherPnt, 
				  const G4ThreeVector& LinePntA, 
				  const G4ThreeVector& LinePntB )
{
  G4LineSection LineAB( LinePntA, LinePntB );  // Line from A to B
  return LineAB.Dist( OtherPnt );
}

#endif
