From b03407900bd5af2c0f098b1ccc26500961850575 Mon Sep 17 00:00:00 2001
From: Andre Govinda Stahl Leiton <andre.govinda.stahl.leiton@cern.ch>
Date: Wed, 2 Oct 2024 16:28:49 +0200
Subject: [PATCH] Add HLT pixel thrust filter

---
 HLTrigger/special/plugins/BuildFile.xml       |  1 +
 .../special/plugins/HLTPixelThrustFilter.cc   | 79 +++++++++++++++++++
 2 files changed, 80 insertions(+)
 create mode 100644 HLTrigger/special/plugins/HLTPixelThrustFilter.cc

diff --git a/HLTrigger/special/plugins/BuildFile.xml b/HLTrigger/special/plugins/BuildFile.xml
index bb9a8e073b2e8..e4a71f8b463a8 100644
--- a/HLTrigger/special/plugins/BuildFile.xml
+++ b/HLTrigger/special/plugins/BuildFile.xml
@@ -54,4 +54,5 @@
 <use name="RecoEcal/EgammaCoreTools"/>
 <use name="TrackingTools/Records"/>
 <use name="TrackingTools/TransientTrack"/>
+<use name="PhysicsTools/CandUtils"/>
 <flags EDM_PLUGIN="1"/>
diff --git a/HLTrigger/special/plugins/HLTPixelThrustFilter.cc b/HLTrigger/special/plugins/HLTPixelThrustFilter.cc
new file mode 100644
index 0000000000000..ce76fc590fe3d
--- /dev/null
+++ b/HLTrigger/special/plugins/HLTPixelThrustFilter.cc
@@ -0,0 +1,79 @@
+#include "FWCore/Framework/interface/global/EDFilter.h"
+#include "FWCore/Framework/interface/Event.h"
+#include "FWCore/Framework/interface/EventSetup.h"
+#include "FWCore/ParameterSet/interface/ParameterSet.h"
+#include "FWCore/ParameterSet/interface/ConfigurationDescriptions.h"
+#include "FWCore/ParameterSet/interface/ParameterSetDescription.h"
+#include "DataFormats/Candidate/interface/LeafCandidate.h"
+#include "DataFormats/SiPixelCluster/interface/SiPixelCluster.h"
+#include "Geometry/CommonDetUnit/interface/PixelGeomDetUnit.h"
+#include "Geometry/TrackerGeometryBuilder/interface/TrackerGeometry.h"
+#include "Geometry/Records/interface/TrackerDigiGeometryRecord.h"
+#include "PhysicsTools/CandUtils/interface/Thrust.h"
+
+//
+// class declaration
+//
+
+class HLTPixelThrustFilter : public edm::global::EDFilter<> {
+public:
+  explicit HLTPixelThrustFilter(const edm::ParameterSet&);
+  ~HLTPixelThrustFilter() override = default;
+  static void fillDescriptions(edm::ConfigurationDescriptions& descriptions);
+  bool filter(edm::StreamID, edm::Event&, edm::EventSetup const&) const final;
+
+private:
+  const edm::ESGetToken<TrackerGeometry, TrackerDigiGeometryRecord> trackerGeometryRcdToken_;
+  const edm::EDGetTokenT<edmNew::DetSetVector<SiPixelCluster> > inputToken_;
+  const double min_thrust_;  // minimum thrust
+  const double max_thrust_;  // maximum thrust
+};
+
+//
+// constructors and destructor
+//
+
+HLTPixelThrustFilter::HLTPixelThrustFilter(const edm::ParameterSet& config)
+    : trackerGeometryRcdToken_(esConsumes()),
+      inputToken_(consumes<edmNew::DetSetVector<SiPixelCluster> >(config.getParameter<edm::InputTag>("inputTag"))),
+      min_thrust_(config.getParameter<double>("minThrust")),
+      max_thrust_(config.getParameter<double>("maxThrust")) {}
+
+void HLTPixelThrustFilter::fillDescriptions(edm::ConfigurationDescriptions& descriptions) {
+  edm::ParameterSetDescription desc;
+  desc.add<edm::InputTag>("inputTag", edm::InputTag("hltSiPixelClusters"));
+  desc.add<double>("minThrust", 0);
+  desc.add<double>("maxThrust", 0);
+  descriptions.add("hltPixelThrustFilter", desc);
+}
+
+//
+// member functions
+//
+// ------------ method called to produce the data  ------------
+bool HLTPixelThrustFilter::filter(edm::StreamID, edm::Event& event, edm::EventSetup const& iSetup) const {
+  // get hold of products from Event
+  auto const& clusters = event.get(inputToken_);
+  auto const& trackerGeo = iSetup.getData(trackerGeometryRcdToken_);
+
+  std::vector<reco::LeafCandidate> vec;
+  for (auto DSViter = clusters.begin(); DSViter != clusters.end(); DSViter++) {
+    auto const& pgdu = static_cast<const PixelGeomDetUnit*>(trackerGeo.idToDetUnit(DSViter->detId()));
+    for (auto const& cluster : *DSViter) {
+      auto const& pos = pgdu->surface().toGlobal(pgdu->specificTopology().localPosition({cluster.x(), cluster.y()}));
+      auto const mag = std::sqrt(pos.x() * pos.x() + pos.y() * pos.y());
+      vec.emplace_back(0, reco::Particle::LorentzVector(pos.x() / mag, pos.y() / mag, 0, 0));
+    }
+  }
+  auto const thrust = Thrust(vec.begin(), vec.end()).thrust();
+
+  bool accept = (thrust >= min_thrust_);
+  if (max_thrust_ > 0)
+    accept &= (thrust <= max_thrust_);
+  // return with final filter decision
+  return accept;
+}
+
+// define as a framework module
+#include "FWCore/Framework/interface/MakerMacros.h"
+DEFINE_FWK_MODULE(HLTPixelThrustFilter);