Herwig HepMC3 interface

Implement Herwig HepMC3 interface

Generators/Herwig7_i/src/Herwig7HepMC.cxx

@@ -25,6 +25,83 @@
 
 #include "ThePEG/Vectors/HepMCConverter.h"
 #ifdef HWVER_IS_72
+#ifdef HEPMC3
+#include "HepMC3/GenEvent.h"
+#include "HepMC3/GenParticle.h"
+#include "HepMC3/GenVertex.h"
+namespace ThePEG {
+  template<>
+  struct HepMCTraits<HepMC3::GenEvent>
+    : public HepMCTraitsBase<HepMC3::GenEvent,
+                             HepMC3::GenParticle,
+                             HepMC3::GenParticlePtr,
+                             HepMC3::GenVertex,
+                             HepMC3::GenVertexPtr,
+                             std::pair<double,double>,
+                             HepMC3::GenPdfInfo>
+  {
+    static bool hasUnits() {
+      return true;
+    }
+
+
+  /** Set the \a scale, \f$\alpha_S\f$ (\a aS) and \f$\alpha_{EM}\f$
+      (\a aEM) for the event \a e. The scale will be scaled with \a
+      unit before given to the GenEvent. */
+  static void setScaleAndAlphas(HepMC3::GenEvent & e, Energy2 scale,
+				double aS,  double aEM, Energy unit) {
+    e.add_attribute("event_scale",std::make_shared<HepMC3::DoubleAttribute>(sqrt(scale)/unit));
+    e.add_attribute("alphaQCD",std::make_shared<HepMC3::DoubleAttribute>(aS));
+    e.add_attribute("alphaQED",std::make_shared<HepMC3::DoubleAttribute>(aEM));
+  }
+
+  /** Set the primary vertex, \a v, for the event \a e. */
+  static void setSignalProcessVertex(HepMC3::GenEvent & e, HepMC3::GenVertexPtr v) {
+  e.add_attribute("signal_process_vertex",std::make_shared<HepMC3::IntAttribute>(v->id()));
+  }
+
+  /** Set the polarization directions, \a the and \a phi, for particle
+      \a p. */
+  static void setPolarization(HepMC3::GenParticle & genp, double the, double phi) {
+    genp.add_attribute("theta",std::make_shared<HepMC3::DoubleAttribute>(the));
+    genp.add_attribute("phi",std::make_shared<HepMC3::DoubleAttribute>(phi));
+  }
+
+  /** Set the colour line (with index \a indx) to \a coline for
+      particle \a p. */
+  static void setColourLine(HepMC3::GenParticle & p, int indx, int coline) {
+	  p.add_attribute("flow"+std::to_string(indx),std::make_shared<HepMC3::IntAttribute>(coline));
+  }
+    /** Set the beam particles for the event.*/
+  static void setBeamParticles(HepMC3::GenEvent & e, HepMC3::GenParticlePtr p1, HepMC3::GenParticlePtr p2) {
+    p1->set_status(4);
+    p2->set_status(4);
+    e.set_beam_particles(p1,p2);
+  }
+  
+    static HepMC3::GenParticlePtr newParticle(const Lorentz5Momentum & p,
+				 long id, int status, Energy unit) {
+    // Note that according to the documentation the momentum is stored in a
+    // HepLorentzVector in GeV (event though the CLHEP standard is MeV).
+    LorentzVector<double> p_scalar = p/unit;
+   HepMC3::GenParticlePtr genp = std::make_shared<HepMC3::GenParticle>(HepMC::FourVector(p_scalar.x(),p_scalar.y(),p_scalar.z(),p_scalar.e()), id, status);
+   genp->set_generated_mass(p.mass()/unit);
+    return genp;
+  }
+    /** Set the position \a p for the vertex, \a v. The length will be
+      scaled with \a unit which normally should be millimeters. */
+  static void setPosition( HepMC3::GenVertex & v, const LorentzPoint & p, Length unit) {
+    LorentzVector<double> p_scaled = p/unit;
+    v.set_position(HepMC::FourVector(p_scaled.x(),p_scaled.y(),p_scaled.z(),p_scaled.t()));
+  }
+  
+    /** Create a new vertex. */
+  static HepMC3::GenVertexPtr newVertex() {
+    return  std::make_shared<HepMC3::GenVertex>();
+  }
+    };
+}
+#else
 namespace ThePEG {
   template<>
   struct HepMCTraits<HepMC::GenEvent>
@@ -41,6 +118,7 @@ namespace ThePEG {
     }
   };
 }
+#endif
 #else
 namespace ThePEG {
   template<>