// *************************************************** // 
// *** Macro for displaying firing tubes per event *** //
// *** Input: digi root file                       *** //
// *** Author: S.Costanza - April 2014             *** // 
// *************************************************** // 

#include <iostream>

read_digi() {

  gROOT->SetStyle("Plain");

  Int_t fVerbose = 1;

  TString namefile = "digi_complete.root";
  TFile InFile(namefile);

  TTree *tree = (TTree*) InFile.Get("cbmsim");
  TClonesArray *digi = new TClonesArray("PndSttHit");
  tree->SetBranchAddress("STTHit", &digi);

  PndSttHit *hit;

  TCanvas *geoCanvas = new TCanvas("geo", "geo", 0, 0, 800, 800);
  TH2F *h = new TH2F("h", "h", 100, 470, 670, 100, -100, 100);
  h->SetStats(kFALSE);

  TArc *straw = NULL;
  TArc *iso   = NULL;

  for (Int_t evt = 0; evt < tree->GetEntriesFast(); evt++) {
    char goOnChar;
    cout << "Press any key to see next event [type .q to exit]: " << endl;
    cin >> goOnChar;
    if (cin.get() == 'q')
      gROOT->ProcessLine(".q");

    tree->GetEntry(evt);

    if (evt%1 == 0)
      cout << "Event # " << evt << ", " 
	   << digi->GetEntriesFast() << " hits" << endl;
  
    h->Draw();

    for (Int_t i = 0; i < digi->GetEntriesFast(); i++) {
      hit = (PndSttHit*) digi->At(i);
      Double_t driftr = hit->GetIsochrone();
      Int_t tubeID = hit->GetTubeID();
      TVector3 pos;
      pos.SetXYZ(hit->GetX(), hit->GetY(), hit->GetZ());
      Double_t phi = TMath::ATan2(pos.Y(), pos.Z());
      if (fVerbose>0) 
	cout << "Tube " << tubeID << ", isochrone = " << driftr 
	     << "\t pos: (" << pos.Z() << ", " << pos.Y() << ")" 
	     << "\t phi " << phi << endl;
      straw = new TArc(pos.Z()*10, pos.Y()*10, 0.5*10);
      straw->Draw("SAME");
      iso = new TArc(pos.Z()*10, pos.Y()*10, driftr*10);
      iso->SetLineColor(kRed);
      iso->Draw("SAME");
    }
    cout << endl;
    geoCanvas->Update();
    geoCanvas->Modified();
  }

}