Flexible config for start layer of ITS tracks

Author: mpuccio

Detectors/ITSMFT/ITS/tracking/include/ITStracking/Configuration.h

@@ -95,7 +95,7 @@ struct TrackingParameters {
   float MaxChi2ClusterAttachment = 60.f;
   float MaxChi2NDF = 30.f;
   std::vector<float> MinPt = {0.f, 0.f, 0.f, 0.f};
-  unsigned char StartLayerMask = 0x7F;
+  std::vector<unsigned short> StartLayerMask = std::vector<unsigned short>(1, 0xFFFF);
   bool FindShortTracks = false;
   bool PerPrimaryVertexProcessing = false;
   bool SaveTimeBenchmarks = false;

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

@@ -573,7 +573,7 @@ void TrackerTraits::findRoads(const int iteration)
     const int minimumLayer{startLevel - 1};
     std::vector<CellSeed> trackSeeds;
     for (int startLayer{mTrkParams[iteration].CellsPerRoad() - 1}; startLayer >= minimumLayer; --startLayer) {
-      if ((mTrkParams[iteration].StartLayerMask & (1 << (startLayer + 2))) == 0) {
+      if ((mTrkParams[iteration].StartLayerMask[mTrkParams[iteration].NLayers - (startLevel + 2)] & (1 << (startLayer + 2))) == 0) {
         continue;
       }
       CA_DEBUGGER(std::cout << "\t\t > Starting processing layer " << startLayer << std::endl);

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

@@ -48,12 +48,14 @@ void ITSTrackingInterface::initialise()
     trackParams[2].CellDeltaTanLambdaSigma *= 4.;
     trackParams[2].MinTrackLength = 4;
     trackParams[2].MinPt[3] = 0.2f;
-    trackParams[2].StartLayerMask = (1 << 6) + (1 << 3);
+    trackParams[2].StartLayerMask = std::vector<unsigned short>(trackParams[2].NLayers - trackParams[2].MinTrackLength + 1, 0x7F);
+    trackParams[2].StartLayerMask[3] = (1 << 6) + (1 << 3);
     if (o2::its::TrackerParamConfig::Instance().doUPCIteration) {
       trackParams[3].TrackletMinPt = 0.1f;
       trackParams[3].CellDeltaTanLambdaSigma *= 4.;
       trackParams[3].MinTrackLength = 4;
       trackParams[3].DeltaROF = 0; // UPC specific setting
+      trackParams[3].StartLayerMask = std::vector<unsigned short>(trackParams[2].NLayers - trackParams[2].MinTrackLength + 1, 0x7F);
     }
     for (auto& param : trackParams) {
       param.ZBins = 64;