TrkExchangeData.cxx

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//--------------------------------------------------------------------------
// File and Version Information:
//      $Id: TrkExchangeData.cxx,v 1.3 2010/03/25 09:56:26 zhangy Exp $
//
//  Description:
//  Class TrkExchangeData;
//
// Environment:
//      Software developed for the BaBar Detector at the SLAC B-Factory.
//
// Copyright Infomation;
//  Copyright (C) 2000  Lawrence Berkeley Laboratory
//
// Author(s): Dave Brown
//
//------------------------------------------------------------------------
#include "TrkBase/TrkExchangeData.h"
#include "MdcGeom/Constants.h"
#include "MdcRecoUtil/ComPackBase.h"
#include "MdcRecoUtil/ComPackFlatFloat.h"
#include "MdcRecoUtil/ComPackSignedExpFloat.h"
#include <assert.h>
#include <math.h>
#define BITSPERBYTE 8
 
// packing statics.  Note that these define the meaning of the data
// and should NEVER BE CHANGED.  Or, if they must be changed, this
// class will need to be subclassed and any persistent data based on it
// have its schema 'migrated'.
 
const ComPackSignedExpFloat TrkExchangeData::_packd0( 16, 6, 128.0 );
const ComPackFlatFloat      TrkExchangeData::_packphi0( -Constants::pi, Constants::pi, 16 );
const ComPackSignedExpFloat TrkExchangeData::_packomega( 16, 6, 0.5 );
const ComPackSignedExpFloat TrkExchangeData::_packz0( 16, 6, 256.0 );
const ComPackFlatFloat TrkExchangeData::_packlambda( -Constants::pi / 2.0, Constants::pi / 2.0,
                                                     16 );
 
const ComPackBase<double>& TrkExchangeData::paramPacker( int index ) {
  switch ( index )
  {
  case TrkExchangePar::ex_d0: return _packd0;
  case TrkExchangePar::ex_phi0: return _packphi0;
  case TrkExchangePar::ex_omega: return _packomega;
  case TrkExchangePar::ex_z0: return _packz0;
  case TrkExchangePar::ex_tanDip: return _packlambda;
  default: assert( 0 ); return _packd0;
  }
}
 
TrkExchangeData::TrkExchangeData() {
  for ( unsigned ipar = 0; ipar < TrkExchangePar::nParam; ipar++ ) _params[ipar] = 0;
}
 
TrkExchangeData::TrkExchangeData( const TrkExchangePar* traj ) {
  // pack the parameters and the diagonal errors
  assert( traj != 0 );
  for ( int ipar = TrkExchangePar::ex_d0; ipar < TrkExchangePar::nParam; ipar++ )
  {
    unsigned                   parpack( 0 );
    const ComPackBase<double>& packpar = paramPacker( ipar );
    // convert from tandip to dip
    double pval( 0 );
    switch ( ipar )
    {
    case TrkExchangePar::ex_d0: pval = traj->d0(); break;
    case TrkExchangePar::ex_phi0: pval = traj->phi0(); break;
    case TrkExchangePar::ex_omega: pval = traj->omega(); break;
    case TrkExchangePar::ex_z0: pval = traj->z0(); break;
    case TrkExchangePar::ex_tanDip: pval = atan( traj->tanDip() ); break;
    }
    ComPackBaseBase::StatusCode pcode = packpar.pack( pval, parpack );
    assert( pcode != ComPackBaseBase::TAG_BAD );
    _params[ipar] = parpack;
  }
}
 
TrkExchangeData::TrkExchangeData( const TrkExchangeData& other ) { *this = other; }
 
TrkExchangeData& TrkExchangeData::operator=( const TrkExchangeData& other ) {
  if ( this != &other )
  {
    for ( int ipar = TrkExchangePar::ex_d0; ipar < TrkExchangePar::nParam; ipar++ )
      _params[ipar] = other._params[ipar];
  }
  return *this;
}
 
TrkExchangeData::~TrkExchangeData() {}
 
TrkExchangePar* TrkExchangeData::exchange() const {
  // unpack the parameters and the errors
  HepVector pvec( 5, 0 );
  for ( int ipar = TrkExchangePar::ex_d0; ipar < TrkExchangePar::nParam; ipar++ )
  {
    const ComPackBase<double>&  packpar = paramPacker( ipar );
    ComPackBaseBase::StatusCode pcode   = packpar.unpack( _params[ipar], pvec[ipar] );
    assert( pcode != ComPackBaseBase::TAG_BAD );
  }
  // convert back from dip to tandip
  pvec[TrkExchangePar::ex_tanDip] = tan( pvec[TrkExchangePar::ex_tanDip] );
  return new TrkExchangePar( pvec );
}