Update THcHallCSpectrometer and THcExtTarCor

THcHallCSpectrometer
  1) Add variables fMispointing_x and fMispointing_y
    which are filled by parameters hmispointing_x, hmispointing_y
      in PARAM/HMS/GEN/hmsflags.param and pmispointing_x, pmispointing_y
      in PARAM/SHMS/GEN/shmsflags.param .
   The offsets are used in THcExtTarCor and THaReactionPoint
  2) Modify argument to method CalculateTargetQuantities to be xtar
     instead of gbeam_y .

THcExtTarCor
   1) add call to get spectrometer pointing offsets
   2) The mispointing_x is added to xtar
   3) Set xtar to start as -beam_y = - vertex(1)+mispointing_x for first call to CalculateTargetQuantities
      After first call the xtar is recalculated using the returned xptar
      and a second call is done to get the target xptar,ytar,yptar and delta.
    4) Fill golden track with final xtar

src/THcExtTarCor.cxx

@@ -128,7 +128,8 @@ Int_t THcExtTarCor::Process( const THaEvData& )
   Double_t delta;
   Double_t p=0;
   TVector3 pvect;
-  Double_t xtar_new=vertex[1];
+  TVector3 pointing_off=spectro->GetPointingOffset();
+  Double_t xtar_new=-vertex[1];
   TClonesArray* tracks = spectro->GetTracks();
   if( !tracks ){
     return -2;
@@ -137,19 +138,18 @@ Int_t THcExtTarCor::Process( const THaEvData& )
     THaTrack* theTrack = static_cast<THaTrack*>( tracks->At(i) );
     if( theTrack == spectro->GetGoldenTrack() ) {
       // Calculate corrections & recalculate ,,,track parameters
-      //cout << " orig" << spectro->GetName() << " " <<theTrack->GetTTheta()<< " " << theTrack->GetDp() << endl;
-      Double_t x_tg = vertex[1];
+      Double_t x_tg = -vertex[1]+pointing_off[0]; // units of cm, beam position in spectrometer coordinate system
       spectro->CalculateTargetQuantities(theTrack,x_tg,xptar,ytar,yptar,delta);
       p  = spectro->GetPcentral() * ( 1.0+delta );
       spectro->TransportToLab( p, xptar, yptar, pvect );
       Double_t theta=spectro->GetThetaSph();
-      xtar_new = x_tg - xptar*ztarg*cos(theta);
+      xtar_new = x_tg - xptar*ztarg*cos(theta); //units of cm
       // Get a second-iteration value for x_tg based on the 
       spectro->CalculateTargetQuantities(theTrack,xtar_new,xptar,ytar,yptar,delta);
       fDeltaDp = delta*100 -theTrack->GetDp();
       fDeltaP = p - theTrack->GetP();
       fDeltaTh = xptar -  theTrack->GetTTheta();
-     theTrack->SetTarget(0.0, ytar*100.0, xptar, yptar);
+     theTrack->SetTarget(xtar_new, ytar*100.0, xptar, yptar);
     theTrack->SetDp(delta*100.0);	// Percent.  
     Double_t ptemp =spectro->GetPcentral()*(1+theTrack->GetDp()/100.0);
       theTrack->SetMomentum(ptemp);

src/THcHallCSpectrometer.cxx

@@ -207,6 +207,8 @@ Int_t THcHallCSpectrometer::ReadDatabase( const TDatime& date )
     {"theta_lab",             &fTheta_lab,             kDouble               },
     {"partmass",              &fPartMass,              kDouble               },
     {"phi_lab",               &fPhi_lab,               kDouble,         0,  1},
+    {"mispointing_x",               &fMispointing_x,               kDouble,         0,  1},
+    {"mispointing_y",               &fMispointing_y,               kDouble,         0,  1},
     {"sel_using_scin",        &fSelUsingScin,          kInt,            0,  1},
     {"sel_using_prune",       &fSelUsingPrune,         kInt,            0,  1},
     {"sel_ndegreesmin",       &fSelNDegreesMin,        kDouble,         0,  1},
@@ -238,6 +240,8 @@ Int_t THcHallCSpectrometer::ReadDatabase( const TDatime& date )
   fSelUsingPrune = 0;
   fPhi_lab = 0.;
   fSatCorr=0.;
+  fMispointing_x=0.;
+  fMispointing_y=0.;
   gHcParms->LoadParmValues((DBRequest*)&list,prefix);
 
   EnforcePruneLimits();
@@ -270,9 +274,8 @@ Int_t THcHallCSpectrometer::ReadDatabase( const TDatime& date )
   // Computes TRotation fToLabRot and fToTraRot
   Bool_t bend_down = kFALSE;
   SetCentralAngles(fTheta_lab, ph, bend_down);
-  Double_t off_x = 0.0, off_y = 0.0, off_z = 0.0;
-  fPointingOffset.SetXYZ( off_x, off_y, off_z );
-
+  Double_t off_z = 0.0;
+  fPointingOffset.SetXYZ( fMispointing_x, fMispointing_y, off_z );
   //
   ifstream ifile;
   ifile.open(reconCoeffFilename.c_str());
@@ -388,7 +391,7 @@ Int_t THcHallCSpectrometer::FindVertices( TClonesArray& tracks )
   return 0;
 }
 //
-void THcHallCSpectrometer::CalculateTargetQuantities(THaTrack* track,Double_t& gbeam_y,Double_t&  xptar,Double_t& ytar,Double_t& yptar,Double_t& delta) 
+void THcHallCSpectrometer::CalculateTargetQuantities(THaTrack* track,Double_t& xtar,Double_t&  xptar,Double_t& ytar,Double_t& yptar,Double_t& delta) 
 {
     Double_t hut[5];
     Double_t hut_rot[5];
@@ -398,7 +401,7 @@ void THcHallCSpectrometer::CalculateTargetQuantities(THaTrack* track,Double_t& g
     hut[2] = track->GetY()/100.0 + fZTrueFocus*track->GetPhi() + fDetOffset_y;//m
     hut[3] = track->GetPhi() + fAngOffset_y;//radians
 
-    hut[4] = -gbeam_y/100.0;
+    hut[4] = xtar/100.0;
 
     // Retrieve the focal plane coordnates
     // Do the transpormation

src/THcHallCSpectrometer.h

@@ -144,6 +144,8 @@ protected:
   Double_t fPCentralOffset; // Offset Central spectrometer momentum (%)
   Double_t fTheta_lab; // Central spectrometer angle (deg)
   Double_t fPhi_lab; // Central spectrometer angle (deg)
+  Double_t fMispointing_x; // Spectrometer Verticcal Mispointing
+  Double_t fMispointing_y; // Spectrometer Horizontal Mispointing
   // For spectrometer central momentum use fPcentral in THaSpectrometer.h
   //  THaScintillator *sc_ref;  // calculate time track hits this plane