Implementation of hybrid generator (#13699)

* Implementation of hybrid generator

This new meta-generator allows the users to use all the O2 implemented
generators combined together, configuring them via a JSON file. Each gen
will be defined as a subgenerator of the primary hybrid one, whose
initialisation happens at the GeneratorFactory level.

* Include SimExamples folder in installation

(cherry picked from commit d6a50f0)

Author: jackal1-66

Generators/CMakeLists.txt

@@ -24,6 +24,8 @@ o2_add_library(Generators
                        src/GeneratorTGenerator.cxx
                        src/GeneratorExternalParam.cxx
                        src/GeneratorFromFile.cxx
+                       src/GeneratorHybrid.cxx
+                       src/GeneratorHybridParam.cxx
                        src/GeneratorFromO2KineParam.cxx
                        src/GeneratorFileOrCmd.cxx
                        src/GeneratorFileOrCmdParam.cxx
@@ -67,6 +69,8 @@ set(headers
     include/Generators/GeneratorTGenerator.h
     include/Generators/GeneratorExternalParam.h
     include/Generators/GeneratorFromFile.h
+    include/Generators/GeneratorHybrid.h
+    include/Generators/GeneratorHybridParam.h
     include/Generators/GeneratorFromO2KineParam.h
     include/Generators/GeneratorFileOrCmd.h
     include/Generators/GeneratorFileOrCmdParam.h

Generators/include/Generators/BoxGenerator.h

@@ -17,6 +17,7 @@
 #include "Generators/Generator.h"
 #include "TParticle.h"
 #include <vector>
+#include <Generators/BoxGunParam.h>
 
 namespace o2::eventgen
 {
@@ -45,6 +46,13 @@ class BoxGenerator : public Generator
     SetPhiRange(phimin, phimax);
   }
 
+  BoxGenerator(BoxGenConfig const& config) : mPDG{config.pdg}, mMult{config.number}
+  {
+    SetEtaRange(config.eta[0], config.eta[1]);
+    SetPRange(config.prange[0], config.prange[1]);
+    SetPhiRange(config.phirange[0], config.phirange[1]);
+  }
+
   void SetPRange(Double32_t pmin = 0, Double32_t pmax = 10)
   {
     mPMin = pmin;

Generators/include/Generators/BoxGunParam.h

@@ -37,6 +37,14 @@ struct BoxGunParam : public o2::conf::ConfigurableParamHelper<BoxGunParam> {
   O2ParamDef(BoxGunParam, "BoxGun");
 };
 
+struct BoxGenConfig {
+  int pdg = 211;                   // which particle (default pion); could make this an enum
+  int number = 10;                 // how many particles
+  double eta[2] = {-1, 1};         // eta range
+  double prange[2] = {0.1, 5};     // energy range min, max in GeV
+  double phirange[2] = {0., 360.}; // phi range
+};
+
 } // end namespace eventgen
 } // end namespace o2
 

Generators/include/Generators/GeneratorExternalParam.h

@@ -34,6 +34,11 @@ struct GeneratorExternalParam : public o2::conf::ConfigurableParamHelper<Generat
   O2ParamDef(GeneratorExternalParam, "GeneratorExternal");
 };
 
+struct ExternalGenConfig {
+  std::string fileName = "";
+  std::string funcName = "";
+};
+
 } // end namespace eventgen
 } // end namespace o2
 

Generators/include/Generators/GeneratorFileOrCmd.h

@@ -35,6 +35,9 @@ struct GeneratorFileOrCmd {
    * function so as to better facilitate changes. */
   void setup(const GeneratorFileOrCmdParam& param,
              const conf::SimConfig& config);
+  // Configure with local parameters
+  void setup(const FileOrCmdGenConfig& param,
+             const conf::SimConfig& config);
   /**
    * Set command to execute in bacground rather than reading from
    * existing file(s)

Generators/include/Generators/GeneratorFileOrCmdParam.h

@@ -39,6 +39,11 @@ struct GeneratorFileOrCmdParam : public o2::conf::ConfigurableParamHelper<Genera
   O2ParamDef(GeneratorFileOrCmdParam, "GeneratorFileOrCmd");
 };
 
+struct FileOrCmdGenConfig {
+  std::string fileNames = "";
+  std::string cmd = ""; // Program command line to spawn
+};
+
 } // end namespace eventgen
 } // end namespace o2
 

Generators/include/Generators/GeneratorFromFile.h

@@ -16,6 +16,7 @@
 
 #include "FairGenerator.h"
 #include "Generators/Generator.h"
+#include "Generators/GeneratorFromO2KineParam.h"
 #include <TRandom3.h>
 #include <TGrid.h>
 
@@ -69,6 +70,7 @@ class GeneratorFromO2Kine : public o2::eventgen::Generator
  public:
   GeneratorFromO2Kine() = default;
   GeneratorFromO2Kine(const char* name);
+  GeneratorFromO2Kine(O2KineGenConfig const& pars);
 
   bool Init() override;
 
@@ -100,6 +102,7 @@ class GeneratorFromO2Kine : public o2::eventgen::Generator
   unsigned int mRngSeed = 0;     //! randomizer seed, 0 for random value
   bool mRandomPhi = false;       //! whether we want to randomize the phi angle of the particles
   TGrid* mAlienInstance = nullptr; // a cached connection to TGrid (needed for Alien locations)
+  std::unique_ptr<O2KineGenConfig> mConfig; //! Configuration object
 
   std::unique_ptr<o2::dataformats::MCEventHeader> mOrigMCEventHeader; //! the MC event header of the original file
 

Generators/include/Generators/GeneratorFromO2KineParam.h

@@ -39,6 +39,16 @@ struct GeneratorFromO2KineParam : public o2::conf::ConfigurableParamHelper<Gener
   O2ParamDef(GeneratorFromO2KineParam, "GeneratorFromO2Kine");
 };
 
+struct O2KineGenConfig {
+  bool skipNonTrackable = true;
+  bool continueMode = false;
+  bool roundRobin = false;   // read events with period boundary conditions
+  bool randomize = false;    // randomize the order of events
+  unsigned int rngseed = 0;  // randomizer seed, 0 for random value
+  bool randomphi = false;    // randomize phi angle
+  std::string fileName = ""; // filename to read from - takes precedence over SimConfig if given
+};
+
 } // end namespace eventgen
 } // end namespace o2
 

Generators/include/Generators/GeneratorHepMC.h

@@ -17,6 +17,7 @@
 #include "Generators/Generator.h"
 #include "Generators/GeneratorFileOrCmd.h"
 #include "Generators/GeneratorHepMCParam.h"
+#include "Generators/GeneratorFileOrCmdParam.h"
 
 #ifdef GENERATORS_WITH_HEPMC3_DEPRECATED
 namespace HepMC
@@ -69,6 +70,10 @@ class GeneratorHepMC : public Generator, public GeneratorFileOrCmd
   void setup(const GeneratorFileOrCmdParam& param0,
              const GeneratorHepMCParam& param,
              const conf::SimConfig& config);
+  // Generator configuration from external local parameters
+  void setup(const FileOrCmdGenConfig& param0,
+             const HepMCGenConfig& param,
+             const conf::SimConfig& config);
   /**
    * Generate a single event.  The event is read in from the current
    * input file.  Returns false if a new event could not be read.
@@ -83,6 +88,7 @@ class GeneratorHepMC : public Generator, public GeneratorFileOrCmd
 
   /** setters **/
   void setEventsToSkip(uint64_t val) { mEventsToSkip = val; };
+  void setVersion(const int& ver) { mVersion = ver; };
 
  protected:
   /** copy constructor **/

Generators/include/Generators/GeneratorHepMCParam.h

@@ -54,6 +54,14 @@ struct GeneratorHepMCParam : public o2::conf::ConfigurableParamHelper<GeneratorH
   O2ParamDef(GeneratorHepMCParam, "HepMC");
 };
 
+struct HepMCGenConfig {
+  // Same parameters as GeneratorHepMCParam
+  int version = 0;
+  uint64_t eventsToSkip = 0;
+  std::string fileName = "";
+  bool prune = false;
+};
+
 } // end namespace eventgen
 } // end namespace o2