ITS: fix time assignment

Author: f3sch

DataFormats/Detectors/ITSMFT/ITS/include/DataFormatsITS/TrackITS.h

@@ -37,7 +37,7 @@ namespace its
 class TrackITS : public o2::track::TrackParCov
 {
   enum UserBits {
-    kSharedClusters = 1 << 29
+    kSharedClusters = 1 << 28
   };
 
   using Cluster = o2::itsmft::Cluster;
@@ -93,7 +93,7 @@ class TrackITS : public o2::track::TrackParCov
 
   GPUhdi() void setChi2(float chi2) { mChi2 = chi2; }
 
-  bool isBetter(const TrackITS& best, float maxChi2) const;
+  bool isBetter(const TrackITS& best, float maxChi2 = o2::constants::math::VeryBig) const;
 
   auto& getTimeStamp() { return mTime; }
   const auto& getTimeStamp() const { return mTime; }

Detectors/ITSMFT/ITS/tracking/src/Configuration.cxx

@@ -24,7 +24,7 @@ using namespace o2::its;
 
 std::string TrackingParameters::asString() const
 {
-  std::string str = std::format("NZb:{} NPhB:{} PerVtx:{} DropFail:{} ClSh:{} TrklMinPt:{:.2f} MinCl:{}", ZBins, PhiBins, PerPrimaryVertexProcessing, DropTFUponFailure, ClusterSharing, TrackletMinPt, MinTrackLength);
+  std::string str = std::format("NZb:{} NPhB:{} PerVtx:{} DropFail:{} ClSh:{} TrklMinPt:{:.2f} MinCl:{} NSigma:{}", ZBins, PhiBins, PerPrimaryVertexProcessing, DropTFUponFailure, ClusterSharing, TrackletMinPt, MinTrackLength, NSigmaCut);
   bool first = true;
   for (int il = NLayers; il >= MinTrackLength; il--) {
     int slot = NLayers - il;

Detectors/ITSMFT/ITS/tracking/src/TrackerTraits.cxx

@@ -570,8 +570,9 @@ void TrackerTraits<NLayers>::findCellSeeds(const int iteration)
         int rof = mTimeFrame->getClusterROF(i, cls[i]);
         int rofStartBC = mTimeFrame->getROFOverlapTableView().getLayer(i).getROFStartInBC(rof);
         int rofEndBC = mTimeFrame->getROFOverlapTableView().getLayer(i).getROFEndInBC(rof);
-        startBC = o2::gpu::CAMath::Min(startBC, rofStartBC);
-        endBC = o2::gpu::CAMath::Max(endBC, rofEndBC);
+        // if the start/end of the cluster is after/before the current bracket need to enlarge
+        startBC = (rofStartBC <= startBC) ? rofStartBC : o2::gpu::CAMath::Max(startBC, rofStartBC);
+        endBC = (rofEndBC >= endBC) ? rofEndBC : o2::gpu::CAMath::Min(endBC, rofEndBC);
       }
       if (endBC - startBC < 0) { // this should not happen
         ltracks[iCell].markDead();
@@ -1143,15 +1144,17 @@ void TrackerTraits<NLayers>::findRoads(const int iteration)
       }
 
       deepVectorClear(trackSeeds);
+      // sort tracks in quality (accounting for 1. length; 2. chi2)
+      // needed since then tracks with shared clusters can be marked/discarded
       tbb::parallel_sort(tracks.begin(), tracks.end(), [](const auto& a, const auto& b) {
-        return a.getChi2() < b.getChi2();
+        return a.isBetter(b);
       });
     });
 
     for (auto& track : tracks) {
       int nShared = 0;
       bool isFirstShared{false};
-      int firstLayer{-1}, firstCluster{-1};
+      int firstLayer{constants::UnusedIndex}, firstCluster{constants::UnusedIndex};
       for (int iLayer{0}; iLayer < mRecoParams[iteration].params.NLayers; ++iLayer) {
         if (track.getClusterIndex(iLayer) == constants::UnusedIndex) {
           continue;
@@ -1172,17 +1175,20 @@ void TrackerTraits<NLayers>::findRoads(const int iteration)
 
       // here we can do the calculation of the time bracket simply
       // by checkig in which rofs the clusters are
+      // also mark used clusters for the next iteration
       int bcStart{0}, bcEnd{std::numeric_limits<int>::max()};
       for (int iLayer{0}; iLayer < mRecoParams[iteration].params.NLayers; ++iLayer) {
         if (track.getClusterIndex(iLayer) == constants::UnusedIndex) {
           continue;
         }
         mTimeFrame->markUsedCluster(iLayer, track.getClusterIndex(iLayer));
         int currentROF = mTimeFrame->getClusterROF(iLayer, track.getClusterIndex(iLayer));
-        int bcClsSta = mTimeFrame->getROFOverlapTableView().getLayer(iLayer).getROFStartInBC(currentROF);
-        int bcClsEnd = mTimeFrame->getROFOverlapTableView().getLayer(iLayer).getROFEndInBC(currentROF);
-        bcStart = std::max(bcStart, bcClsSta);
-        bcEnd = std::min(bcEnd, bcClsEnd);
+        // need to account for the imposed delay
+        int bcClsSta = mTimeFrame->getROFOverlapTableView().getLayer(iLayer).getROFStartInBC(currentROF, true);
+        int bcClsEnd = mTimeFrame->getROFOverlapTableView().getLayer(iLayer).getROFEndInBC(currentROF, true);
+        // if the start/end of the cluster is after/before the current bracket need to enlarge
+        bcStart = (bcClsEnd <= bcStart) ? bcClsSta : o2::gpu::CAMath::Max(bcStart, bcClsSta);
+        bcEnd = (bcClsSta >= bcEnd) ? bcClsEnd : o2::gpu::CAMath::Min(bcEnd, bcClsEnd);
       }
       track.getTimeStamp().setTimeStamp(bcStart);
       track.getTimeStamp().setTimeStampError(bcEnd - bcStart + 1);