Bug fix

[u/mrichter/AliRoot.git] / STEER / AliTrackReference.cxx

diff --git a/STEER/AliTrackReference.cxx b/STEER/AliTrackReference.cxx
index fac67b2b4800dfcfb102f634a74c23c6b2a198ab..1076bb8b67c90ec478ad520eb0c1e78277b60cf0 100644 (file)
--- a/STEER/AliTrackReference.cxx
+++ b/STEER/AliTrackReference.cxx
@@ -13,17 +13,129 @@
  * provided "as is" without express or implied warranty.                  *
  **************************************************************************/
 
+/* $Id$ */
+
+#include "TVirtualMC.h"
 
-#include "AliTrackReference.h"
-#include "TParticle.h"
 #include "AliRun.h"
+#include "AliTrackReference.h"
+#include "AliExternalTrackParam.h"
+#include "AliKalmanTrack.h"
+
+// 
+// Track Reference object is created every time particle is 
+// crossing detector bounds. The object is created by Step Manager
+//
+// The class stores the following informations:
+// track label, 
+// track position: X,Y,X
+// track momentum px, py, pz
+// track length and time of fligth: both in cm
+// status bits from Monte Carlo
+//
+
 
 ClassImp(AliTrackReference)
 
-AliTrackReference::AliTrackReference()
+//_______________________________________________________________________
+ AliTrackReference::AliTrackReference():
+   TObject(),
+   fTrack(0),
+   fX(0),
+   fY(0),
+   fZ(0),
+   fPx(0),
+   fPy(0),
+   fPz(0),
+   fLength(0),
+   fTime(0),
+   fUserId(0)
 {
   //
   // Default constructor
+  // Creates empty object
+
+  for(Int_t i=0; i<16; i++) ResetBit(BIT(i));
+}
+
+//_______________________________________________________________________
+AliTrackReference::AliTrackReference(Int_t label) :
+  TObject(),
+  fTrack(label),
+  fX(0),
+  fY(0),
+  fZ(0),
+  fPx(0),
+  fPy(0),
+  fPz(0),
+  fLength(gMC->TrackLength()),
+  fTime(gMC->TrackTime()),
+  fUserId(0)
+{
+  //
+  // Create Reference object out of label and
+  // data in TVirtualMC object
+  //
+  // Creates an object and fill all parameters 
+  // from data in VirtualMC
+  //
+  // Sylwester Radomski, (S.Radomski@gsi.de)
+  // GSI, Jan 31, 2003
   //
-  fTrack=0;    
+    
+  Double_t vec[4];
+  
+  gMC->TrackPosition(vec[0],vec[1],vec[2]);
+
+  fX = vec[0];
+  fY = vec[1];
+  fZ = vec[2];
+  
+  gMC->TrackMomentum(vec[0],vec[1],vec[2],vec[3]);
+  
+  fPx = vec[0];
+  fPy = vec[1];
+  fPz = vec[2];
+
+  // Set Up status code 
+  // Copy Bits from virtual MC
+
+  for(Int_t i=0; i<16; i++) ResetBit(BIT(i));
+
+  SetBit(BIT(0), gMC->IsNewTrack());
+  SetBit(BIT(1), gMC->IsTrackAlive());
+  SetBit(BIT(2), gMC->IsTrackDisappeared());
+  SetBit(BIT(3), gMC->IsTrackEntering());
+  SetBit(BIT(4), gMC->IsTrackExiting());
+  SetBit(BIT(5), gMC->IsTrackInside());
+  SetBit(BIT(6), gMC->IsTrackOut());
+  SetBit(BIT(7), gMC->IsTrackStop()); 
 }
+//_______________________________________________________________________
+AliExternalTrackParam * AliTrackReference::MakeTrack(const AliTrackReference *ref, Double_t mass)
+{
+  //
+  // Make dummy track from the track reference 
+  // negative mass means opposite charge 
+  //
+  Double_t xx[5];
+  Double_t cc[15];
+  for (Int_t i=0;i<15;i++) cc[i]=0;
+  Double_t x = ref->X(), y = ref->Y(), z = ref->Z();
+  Double_t alpha = TMath::ATan2(y,x);
+  Double_t xr = TMath::Sqrt(x*x+y*y);
+  xx[0] = ref->LocalY();
+  xx[1] = z;
+  xx[3] = ref->Pz()/ref->Pt();
+  xx[4] = 1./ref->Pt(); 
+  if (mass<0) xx[4]*=-1.;  // negative mass - negative direction
+  Double_t alphap = TMath::ATan2(ref->Py(),ref->Px())-alpha;
+  if (alphap> TMath::Pi()) alphap-=TMath::Pi();
+  if (alphap<-TMath::Pi()) alphap+=TMath::Pi();
+  xx[2] = TMath::Sin(alphap);
+
+  AliExternalTrackParam * track = new  AliExternalTrackParam(xr,alpha,xx,cc);
+  return track;
+}
+
+