SingleHoughSpaceFastInterceptFinder.h

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
#pragma once
 
#include <tracking/trackingUtilities/findlets/base/Findlet.h>
 
#include <bitset>
#include <array>
#include <unordered_map>
 
namespace Belle2 {
  class ModuleParamList;
 
  namespace vxdHoughTracking {
    class VXDHoughState;

    class SingleHoughSpaceFastInterceptFinder : public TrackingUtilities::Findlet<VXDHoughState, std::vector<VXDHoughState*>> {
      using Super = TrackingUtilities::Findlet<VXDHoughState, std::vector<VXDHoughState*>>;
 
    public:
      SingleHoughSpaceFastInterceptFinder();

      void exposeParameters(ModuleParamList* moduleParamList, const std::string& prefix) override;

      void initialize() override;

      void apply(std::vector<VXDHoughState>& hits, std::vector<std::vector<VXDHoughState*>>& rawTrackCandidates) override;
 
    private:

      static inline unsigned short layerFilter(const std::bitset<8>& layer)
      {
        ushort layercount = static_cast<ushort>(layer.count());
        return (layercount >= 3 ? layercount : 0);
      }

      void fastInterceptFinder2d(const std::vector<VXDHoughState*>& hits, const ushort xmin, const ushort xmax,
                                 const ushort ymin, const ushort ymax, const ushort currentRecursion);

      void FindHoughSpaceCluster();

      void DepthFirstSearch(const uint lastGlobalSectorIndex);
 
      // Parameters
      ushort m_maxRecursionLevel = 9;

      ushort m_nAngleSectors = 512;

      ushort m_nVerticalSectors = 512;

      float m_verticalHoughSpaceSize = 0.16;

      float m_minimumX = -3.168;
      float m_maximumX = 3.168;

      ushort m_MinimumHSClusterSize = 1;
      ushort m_MaximumHSClusterSize = 12;
      ushort m_MaximumHSClusterSizeX = 2;
      ushort m_MaximumHSClusterSizeY = 12;
 
      // class variables
      float m_unitX = 0;
      float m_unitY = 0;

      static const ushort c_maxAllowedRecusionLevel = 10;
      static constexpr ushort c_maxHSSectorNumber = (1 << c_maxAllowedRecusionLevel);
      static constexpr ushort c_xIndexBitMask = c_maxHSSectorNumber - 1;
      static constexpr ushort c_maxLUTSize = c_maxHSSectorNumber + 1;

      std::array<float, c_maxLUTSize> m_HSSinValuesLUT = {0};
      std::array<float, c_maxLUTSize> m_HSCosValuesLUT = {0};
      std::array<float, c_maxHSSectorNumber> m_HSCenterSinValuesLUT = {0};
      std::array<float, c_maxHSSectorNumber> m_HSCenterCosValuesLUT = {0};

      std::unordered_map<uint, std::vector<VXDHoughState*>> m_activeSectorsMap;
      std::vector<uint> m_activeSectorsIndices;

      ushort m_clusterCount = 0;
      ushort m_clusterSize = 0;

      std::pair<ushort, ushort> m_clusterInitialPosition = std::make_pair(0, 0);

      std::vector<VXDHoughState*> m_currentTrackCandidate;

      std::vector<std::vector<VXDHoughState*>> m_trackCandidates;
 
    };
 
  }
}