Implemented a remapper for parent identification in the particle tree when adding...

diff --git a/EVGEN/AliGenExtFile.cxx b/EVGEN/AliGenExtFile.cxx
index a32f12062c81fd43a7823aea39904c4a4afa0693..0ed34556b2db701fddf02a4590478ff339a36ec2 100644 (file)
--- a/EVGEN/AliGenExtFile.cxx
+++ b/EVGEN/AliGenExtFile.cxx
@@ -157,11 +157,28 @@ void AliGenExtFile::Generate()
     //
     // Stack filling loop
     //
+    map<Int_t,Int_t> newIdMap;
+    map<Int_t,Int_t> newFirstMotherMap;
     fNprimaries = 0;
     for (i = 0; i < nTracks; i++) {
-       TParticle* jparticle = fReader->NextParticle();
-       Bool_t selected = KinematicSelection(jparticle,0); 
-       if (!selected) continue;
+       TParticle* jparticle = fReader->NextParticle();
+       Int_t parent = jparticle->GetFirstMother();
+       if (parent > -1) {
+          Int_t parentNewId = newIdMap[parent];
+          if (parentNewId == -1) { // if parent was skipped
+             parent = newFirstMotherMap[parent]; // re-adjust parent using stored information
+          } else {
+             parent = parentNewId; // otherwise re-map parent to new id
+          }
+       }
+       newFirstMotherMap[i] = parent; // store re-mapped parent data so child nodes can use it
+       Bool_t selected = KinematicSelection(jparticle,0);
+       if (!selected) {
+          newIdMap[i] = -1; // -1 marks this particle was skipped
+          continue;
+       }
+       newIdMap[i] = fNprimaries; // maps old id to new id
+
        p[0] = jparticle->Px();
        p[1] = jparticle->Py();
        p[2] = jparticle->Pz();
@@ -187,7 +204,6 @@ void AliGenExtFile::Generate()
            time = fTime + jparticle->T();
        }
        Int_t doTracking = fTrackIt && selected && (jparticle->TestBit(kTransportBit));
-       Int_t parent     = jparticle->GetFirstMother();
        
        PushTrack(doTracking, parent, idpart,
                  p[0], p[1], p[2], p[3], origin[0], origin[1], origin[2], time,