#include "Generators/Trigger.h"

#include "TParticle.h"

#include <iostream>

// a very simple trigger example, examining generated particles

o2::eventgen::Trigger trigger()

{

//

return [](const std::vector<TParticle>& particles) -> bool {

std::cout << "Running trigger on event with size " << particles.size() << "\n";

if (particles.size() > 10000) {

return true;

}

return false;

};

}

#include "Pythia8/Pythia.h"

#include "Pythia8/HIInfo.h"

#include <fairlogger/Logger.h>

// a deep trigger example, looking into the internal generator state

o2::eventgen::DeepTrigger

trigger_impactb_pythia8(double bmin = 5., double bmax = 10.)

{

return [bmin, bmax](void* interface, std::string name) -> bool {

if (!name.compare("pythia8")) {

auto py8 = reinterpret_cast<Pythia8::Pythia*>(interface);

#if PYTHIA_VERSION_INTEGER < 8300

auto hiinfo = py8->info.hiinfo;

#else

auto hiinfo = py8->info.hiInfo;

#endif

if (!hiinfo) {

LOG(fatal) << "Cannot define impact parameter: is \'pythia8\' running in heavy-ion mode?";

}

auto b = hiinfo->b();

auto selected = (b > bmin && b < bmax);

LOG(info) << "Impact parameter = " << b << " fm: " << (selected ? "selected" : "rejected");

return selected;

} else {

LOG(fatal) << "Cannot define impact parameter for generator interface \'" << name << "\'";

}

return false;

};

}