generators/HIJINGFlipAfterburner/HIJINGFlipAfterburner.cc

0001
0002 #include "HIJINGFlipAfterburner.h"
0003
0004 #include <fun4all/Fun4AllReturnCodes.h>
0005
0006 #include <phool/PHCompositeNode.h>
0007 #include <phool/getClass.h>
0008 // phhepmc
0009 #include <phhepmc/PHHepMCGenEvent.h>
0010 #include <phhepmc/PHHepMCGenEventMap.h>
0011
0012 // hepmc
0013 #pragma GCC diagnostic push
0014 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
0015 #include <HepMC/GenEvent.h>
0016 #include <HepMC/GenParticle.h>  // for GenParticle
0017 #include <HepMC/GenVertex.h>    // for GenVertex, GenVertex::part...
0018 #include <HepMC/SimpleVector.h>
0019 #pragma GCC diagnostic pop
0020
0021 #include <cassert>
0022
0023 //____________________________________________________________________________..
0024 HIJINGFlipAfterburner::HIJINGFlipAfterburner(const std::string &name)
0025   : SubsysReco(name)
0026 {
0027 }
0028
0029 //____________________________________________________________________________..
0030 int HIJINGFlipAfterburner::process_event(PHCompositeNode *topNode)
0031 {
0032   if (!doFlip)
0033   {
0034     doFlip = true;
0035   }
0036   else
0037   {
0038     doFlip = false;
0039     PHHepMCGenEventMap *genevtmap = findNode::getClass<PHHepMCGenEventMap>(topNode, "PHHepMCGenEventMap");
0040     for (auto &iter : *genevtmap)
0041     {
0042       PHHepMCGenEvent *genevt = iter.second;
0043       HepMC::GenEvent *evt = genevt->getEvent();
0044       assert(evt);
0045       flipZDirection(evt);
0046     }
0047   }
0048
0049   return Fun4AllReturnCodes::EVENT_OK;
0050 }
0051
0052 void HIJINGFlipAfterburner::flipZDirection(HepMC::GenEvent *event)
0053 {
0054   assert(event);
0055
0056   for (auto v = event->vertices_begin(); v != event->vertices_end(); ++v)
0057   {
0058     HepMC::FourVector position = (*v)->position();
0059
0060     position.setZ(-position.z());
0061     position.setX(-position.x());
0062
0063     (*v)->set_position(position);
0064   }
0065
0066   for (auto p = event->particles_begin(); p != event->particles_end(); ++p)
0067   {
0068     HepMC::FourVector momentum = (*p)->momentum();
0069
0070     momentum.setPz(-momentum.pz());
0071     momentum.setPx(-momentum.px());
0072
0073     (*p)->set_momentum(momentum);
0074   }
0075 }