C++ TParticle::GetFirstDaughter方法代码示例

void kine_daughters(IlcEveTrack* parent,  IlcStack* stack,
		    Double_t     min_pt,  Double_t  min_p,
		    Bool_t       pdg_col, Bool_t    recurse)
{
  TParticle *p = stack->Particle(parent->GetLabel());
  if (p->GetNDaughters() > 0)
  {
    TEveTrackPropagator* rs = parent->GetPropagator();
    for (int d=p->GetFirstDaughter(); d>0 && d<=p->GetLastDaughter(); ++d)
    {
      TParticle* dp = stack->Particle(d);
      if (dp->Pt() < min_pt && dp->P() < min_p) continue;

      IlcEveTrack* dtrack = new IlcEveTrack(dp, d, rs);
      char form[1000];
      sprintf(form,"%s [%d]", dp->GetName(), d);
      dtrack->SetName(form);
      dtrack->SetStdTitle();
      set_track_color(dtrack, pdg_col);

      gEve->AddElement(dtrack, parent);

      if (recurse)
	kine_daughters(dtrack, stack, min_pt, min_p, pdg_col, recurse);
    }
  }
}

void GetFinalDecayProducts(Int_t ind, IlcStack & stack , TArrayI & ar){

  // Recursive algorithm to get the final decay products of a particle
  //
  // ind is the index of the particle in the IlcStack
  // stack is the particle stack from the generator
  // ar contains the indexes of the final decay products
  // ar[0] is the number of final decay products

  if (ind<0 || ind>stack.GetNtrack()) {
    cerr << "Invalid index of the particle " << ind << endl;
    return;
  } 
  if (ar.GetSize()==0) {
    ar.Set(10);
    ar[0] = 0;
  }

  TParticle * part = stack.Particle(ind);

  Int_t iFirstDaughter = part->GetFirstDaughter();
  if( iFirstDaughter<0) {
    // This particle is a final decay product, add its index to the array
    ar[0]++;
    if (ar.GetSize() <= ar[0]) ar.Set(ar.GetSize()+10); // resize if needed
    ar[ar[0]] = ind;
    return;
  } 

  Int_t iLastDaughter = part->GetLastDaughter();

  for (Int_t id=iFirstDaughter; id<=iLastDaughter;id++) {
    // Now search for final decay products of the daughters
    GetFinalDecayProducts(id,stack,ar);
  }
}

TEveElement*
kine_track(Int_t  label,
	   Bool_t import_mother, Bool_t import_daughters,
	   Bool_t pdg_col,       Bool_t recurse,
           TEveElement* cont)
{
  // Create mother and daughters tracks with given label.
  // mother     -> particle with label
  // daughters  -> daughters of label

  if (label < 0) {
    Warning("kine_track", "label not set.");
    return 0;
  }

  IlcRunLoader* rl =  IlcEveEventManager::AssertRunLoader();
  rl->LoadKinematics();
  IlcStack* stack = rl->Stack();
  if (!stack)
  {
     Warning("kine_track", "can not get kinematics.");
    return 0;
  }
  if (label >= stack->GetNtrack())
  {
    Warning("kine_track", "label out of range.");
    return 0;
  }

  TParticle* p = stack->Particle(label);

  if (import_mother || (import_daughters && p->GetNDaughters()))
  {
    TEveTrackPropagator* rs = 0;

    if (cont == 0)
    {
      TEveTrackList* tlist = new TEveTrackList
	(Form("Kinematics of %d %d", label, p->GetNDaughters()));
      cont = tlist;

      TEveTrackPropagator* trkProp = tlist->GetPropagator();

      kine_track_propagator_setup(trkProp);

      char tooltip[1000];
      sprintf(tooltip,"Ndaughters=%d", p->GetNDaughters());
      tlist->SetTitle(tooltip);
      trkProp->SetMaxOrbs(2);
      trkProp->SetEditPathMarks(kTRUE);

      gEve->AddElement(cont);
      rs = tlist->GetPropagator();
    }
    else
    {
      // check if container is TEveTrackList or IlcEveTrack (has rnr-style)
      IlcEveTrack* t = dynamic_cast<IlcEveTrack*>(cont);
      if (t) {
	rs = t->GetPropagator();
      } else {
        TEveTrackList* l = dynamic_cast<TEveTrackList*>(cont);
        if (l)
	  rs = l->GetPropagator();
        else
	  Error("kine_tracks.C", "TrackRenderStyle not set.");
      }
    }

    if (import_mother)
    {
      IlcEveTrack* track = new IlcEveTrack(p, label, rs);
      char form[1000];
      sprintf(form,"%s [%d]", p->GetName(), label);
      track->SetName(form);
      track->SetStdTitle();
      set_track_color(track, pdg_col);

      track->MakeTrack();
      gEve->AddElement(track, cont);
      cont = track;
    }

    if (import_daughters && p->GetNDaughters())
    {
      for (int d=p->GetFirstDaughter(); d>0 && d<=p->GetLastDaughter(); ++d)
      {
	TParticle* dp = stack->Particle(d);
	IlcEveTrack* track = new IlcEveTrack(dp, d, rs);
	char form[1000];
	sprintf(form,"%s [%d]", dp->GetName(), d);
	track->SetName(form);
	track->SetStdTitle();
	set_track_color(track, pdg_col);

        track->MakeTrack();
	gEve->AddElement(track, cont);

	if (recurse)
	  kine_daughters(track, stack, 0, 0, pdg_col, recurse);
//.........这里部分代码省略.........