SimulationAlg.cpp

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#include "MCHit.h"
#include "MCTrack.h"
 
#include <Gaudi/Accumulators.h>
#include <Gaudi/Functional/Transformer.h>
 
#include <cmath>
 
namespace {
  std::pair<float, float> sincos( float arg ) { return { std::sin( arg ), std::cos( arg ) }; }
} // namespace
 
namespace Gaudi::Example::TinyExperiment {

  class SimulationAlg : public Functional::Transformer<MCHits( MCTracks const& )> {
  public:
    SimulationAlg( const std::string& name, ISvcLocator* pSvcLocator )
        : Transformer( name, pSvcLocator, { { "MCTracksLocation", "/Event/MCTracks" } },
                       { "MCHitsLocation", "/Event/MCHits" } ) {}
 
    MCHits operator()( MCTracks const& tracks ) const override {
      MCHits hits;
      hits.reserve( tracks.size() * m_nbHitsPerTrack );
      for ( auto const& track : tracks ) {
        auto [s, c] = sincos( track.theta );
        for ( unsigned int i = 0; i < m_nbHitsPerTrack; i++ ) {
          hits.emplace_back( i * c, i * s );
          ++n_hits;
        }
      }
      return hits;
    };
 
  private:
    Gaudi::Property<unsigned int>          m_nbHitsPerTrack{ this, "NbHitsPerTrack", 10 };
    mutable Gaudi::Accumulators::Counter<> n_hits{ this, "Number of MCHits" };
  };
 
  DECLARE_COMPONENT( SimulationAlg )
 
} // namespace Gaudi::Example::TinyExperiment