TEveVector.cxx

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// @(#)root/eve:$Id$
// Author: Matevz Tadel 2007

/*************************************************************************
 * Copyright (C) 1995-2007, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#include "TEveVector.h"
#include "TVector3.h"

/** \class TEveVectorT
\ingroup TEve
Minimal, templated three-vector.
No TObject inheritance and virtual functions.
Also used in VSD.
*/

ClassImp(TEveVectorT<Float_t>);
ClassImp(TEveVectorT<Double_t>);

////////////////////////////////////////////////////////////////////////////////
/// Dump to stdout as "(x, y, z)\n".

template<typename TT> void TEveVectorT<TT>::Dump() const
{
   printf("(%f, %f, %f)\n", fX, fY, fZ);
}

////////////////////////////////////////////////////////////////////////////////
/// Set from TVector3.

template<typename TT> void TEveVectorT<TT>::Set(const TVector3& v)
{
   fX = v.x(); fY = v.y(); fZ = v.z();
}

////////////////////////////////////////////////////////////////////////////////
/// Calculate eta of the point, pretending it's a momentum vector.

template<typename TT> TT TEveVectorT<TT>::Eta() const
{
   TT cosTheta = CosTheta();
   if (cosTheta*cosTheta < 1) return -0.5* TMath::Log( (1.0-cosTheta)/(1.0+cosTheta) );
   Warning("Eta","transverse momentum = 0, returning +/- 1e10");
   return (fZ >= 0) ? 1e10 : -1e10;
}

////////////////////////////////////////////////////////////////////////////////
/// Normalize the vector to length if current length is non-zero.
/// Returns the old magnitude.

template<typename TT> TT TEveVectorT<TT>::Normalize(TT length)
{
   TT m = Mag();
   if (m != 0)
   {
      length /= m;
      fX *= length; fY *= length; fZ *= length;
   }
   return m;
}

////////////////////////////////////////////////////////////////////////////////
/// Returns an orthogonal vector (not normalized).

template<typename TT> TEveVectorT<TT> TEveVectorT<TT>::Orthogonal() const
{
   Float_t xx = fX < 0 ? -fX : fX;
   Float_t yy = fY < 0 ? -fY : fY;
   Float_t zz = fZ < 0 ? -fZ : fZ;
   if (xx < yy) {
      return xx < zz ? TEveVectorT<TT>(0,fZ,-fY) : TEveVectorT<TT>(fY,-fX,0);
   } else {
      return yy < zz ? TEveVectorT<TT>(-fZ,0,fX) : TEveVectorT<TT>(fY,-fX,0);
   }
}

////////////////////////////////////////////////////////////////////////////////
/// Set vectors a and b to be normal to this and among themselves,
/// both of length 1.

template<typename TT> void TEveVectorT<TT>::OrthoNormBase(TEveVectorT<TT>& a, TEveVectorT<TT>& b) const
{
   a = Orthogonal();
   TMath::Cross(this->Arr(), a.Arr(), b.Arr());
   a.Normalize();
   b.Normalize();
}

template class TEveVectorT<Float_t>;
template class TEveVectorT<Double_t>;

/** \class TEveVector4T
\ingroup TEve
Minimal, templated four-vector.
No TObject inheritance and virtual functions.
Also used in VSD.
*/

ClassImp(TEveVector4T<Float_t>);
ClassImp(TEveVector4T<Double_t>);

////////////////////////////////////////////////////////////////////////////////
/// Dump to stdout as "(x, y, z; t)\n".

template<typename TT> void TEveVector4T<TT>::Dump() const
{
   printf("(%f, %f, %f; %f)\n", TP::fX, TP::fY, TP::fZ, fT);
}

template class TEveVector4T<Float_t>;
template class TEveVector4T<Double_t>;

/** \class TEveVector2T
\ingroup TEve
Minimal, templated two-vector.
No TObject inheritance and virtual functions.
Also used in VSD.
*/

ClassImp(TEveVector2T<Float_t>);
ClassImp(TEveVector2T<Double_t>);

////////////////////////////////////////////////////////////////////////////////
/// Normalize the vector to length if current length is non-zero.

template<typename TT> void TEveVector2T<TT>::Normalize(TT length)
{
   Float_t m = Mag();
   if (m != 0)
   {
      m = length / m;
      fX *= m; fY *= m;
   }
}

////////////////////////////////////////////////////////////////////////////////
/// Dump to stdout as "(x, y)\n".

template<typename TT> void TEveVector2T<TT>::Dump() const
{
   printf("(%f, %f)\n", fX, fY);
}

template class TEveVector2T<Float_t>;
template class TEveVector2T<Double_t>;