Add converter from VPHits to VPLightClusters

Needed for Moore!1703 (merged)

Pr/PrPixel/src/PrVPHitsToVPLightClusters.cpp

+/*****************************************************************************\
+* (c) Copyright 2000-2023 CERN for the benefit of the LHCb Collaboration      *
+*                                                                             *
+* This software is distributed under the terms of the GNU General Public      *
+* Licence version 3 (GPL Version 3), copied verbatim in the file "COPYING".   *
+*                                                                             *
+* In applying this licence, CERN does not waive the privileges and immunities *
+* granted to it by virtue of its status as an Intergovernmental Organization  *
+* or submit itself to any jurisdiction.                                       *
+\*****************************************************************************/
+#include <array>
+#include <tuple>
+#include <vector>
+
+// Gaudi
+#include "LHCbAlgs/Transformer.h"
+
+// LHCb
+#include "Detector/VP/VPChannelID.h"
+#include "Event/PrHits.h"
+#include "Event/VPLightCluster.h"
+#include "Kernel/STLExtensions.h"
+#include "PrKernel/VeloPixelInfo.h"
+
+namespace LHCb::Pr::Velo {
+  class PrVPHitsToVPLightClusters
+      : public LHCb::Algorithm::MultiTransformer<std::tuple<
+            std::vector<VPLightCluster>, std::array<unsigned, VeloInfo::Numbers::NOffsets>>( const VP::Hits& )> {
+  public:
+    PrVPHitsToVPLightClusters( const std::string& name, ISvcLocator* pSvcLocator )
+        : MultiTransformer( name, pSvcLocator, {KeyValue{"HitsLocation", "Raw/VP/Hits"}},
+                            {KeyValue{"ClusterLocation", VPClusterLocation::Light},
+                             KeyValue{"ClusterOffsets", "Raw/VP/LightClustersOffsets"}} ) {}
+
+    std::tuple<std::vector<VPLightCluster>, std::array<unsigned, VeloInfo::Numbers::NOffsets>>
+    operator()( const VP::Hits& hits ) const override {
+      auto result = std::tuple<std::vector<VPLightCluster>, std::array<unsigned, VeloInfo::Numbers::NOffsets>>{};
+
+      auto& [pool, offsets] = result;
+      pool.reserve( hits.size() );
+
+      for ( const auto hit : hits.scalar() ) {
+        Detector::VPChannelID cid{static_cast<unsigned>( hit.template get<VP::VPHitsTag::ChannelId>().cast() )};
+        float                 gx = hit.template get<VP::VPHitsTag::pos>().x().cast();
+        float                 gy = hit.template get<VP::VPHitsTag::pos>().y().cast();
+        float                 gz = hit.template get<VP::VPHitsTag::pos>().z().cast();
+        pool.emplace_back( 1, 1, gx, gy, gz, cid );
+        ++offsets[cid.module()];
+      }
+
+      std::partial_sum( offsets.begin(), offsets.end(), offsets.begin() );
+
+      // sorting in phi for even modules
+      auto cmp_phi_for_odd_modules = []( const VPLightCluster& a, const VPLightCluster& b ) {
+        return ( a.y() < 0.f && b.y() > 0.f ) ||
+               // same y side even and odd modules, check y1/x1 < y2/x2
+               ( ( a.y() * b.y() ) > 0.f && ( a.y() * b.x() < b.y() * a.x() ) );
+      };
+
+      // sorting in phi for odd modules
+      auto cmp_phi_for_even_modules = []( const VPLightCluster& a, const VPLightCluster& b ) {
+        return ( a.y() > 0.f && b.y() < 0.f ) ||
+               // same y side even and odd modules, check y1/x1 < y2/x2
+               ( ( a.y() * b.y() ) > 0.f && ( a.y() * b.x() < b.y() * a.x() ) );
+      };
+
+      auto sort_module = [pool = std::ref( pool ), offsets = std::ref( offsets )]( auto id, auto cmp ) {
+        std::sort( pool.get().begin() + offsets.get()[id], pool.get().begin() + offsets.get()[id + 1], cmp );
+      };
+
+      for ( size_t moduleID = 0; moduleID < VeloInfo::Numbers::NModules; ++moduleID ) {
+        if ( moduleID % 2 == 1 ) {
+          sort_module( moduleID, cmp_phi_for_odd_modules );
+        } else {
+          sort_module( moduleID, cmp_phi_for_even_modules );
+        }
+      }
+
+      m_nbClustersCounter += pool.size();
+      return result;
+    }
+
+  private:
+    mutable Gaudi::Accumulators::SummingCounter<> m_nbClustersCounter{this, "Nb of Produced Clusters"};
+  };
+} // namespace LHCb::Pr::Velo
+
+DECLARE_COMPONENT_WITH_ID( LHCb::Pr::Velo::PrVPHitsToVPLightClusters, "PrVPHitsToVPLightClusters" )