g4world.cc

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// g4world.cc : implementation of the Geant4 world builder and material initialization.
// gemc
#include "g4world.h"
#include "gfactory.h"
 
// g4system
#include "g4system_options.h"
#include "g4systemConventions.h"
#include "gsystemConventions.h"
#include "g4objectsFactories/g4native/g4NativeObjectsFactory.h"
#include "g4objectsFactories/cad/cadSystemFactory.h"
 
 
// c++
#include <vector>
 
G4World::G4World(const GWorld *gworld, const std::shared_ptr<GOptions> &gopts)
    : GBase(gopts, G4SYSTEM_LOGGER) {
    auto gsystemMap = gworld->getSystemsMap();
 
    // Phase 1: create and initialize a Geant4 object factory for each system.
    // The factory provides solid/logical/physical creation for volumes in that system.
    createG4SystemFactory(gopts,
                          gsystemMap,
                          gopts->getScalarString("useBackupMaterial"),
                          gopts->getScalarInt("check_overlaps")
    );
 
    // Phase 2: build all materials across systems, resolving dependencies iteratively.
    buildMaterials(gsystemMap);
 
    // Phase 3: ensure common isotopes/elements/materials exist (used by typical configurations).
    buildDefaultMaterialsElementsAndIsotopes();
 
    // Phase 4: build volumes. Some volumes depend on mothers that may not exist yet,
    // so we iterate until the remaining list becomes empty or the dependency resolution stalls.
    std::vector<GVolume *> thisIterationRemainingVolumes;
    unsigned long previousRemainingVolumes = 0;
 
    do {
        thisIterationRemainingVolumes.clear();
 
        // Loop over all systems and attempt to build all volumes in each system.
        for (auto &[systemName, gsystem]: *gsystemMap) {
            std::string g4Factory = g4FactoryNameFromSystemFactory(gsystem->getFactoryName());
            auto objectsFactory = get_factory(g4Factory);
 
            for (auto &[volumeName, gvolumePtr]: gsystem->getGVolumesMap()) {
                auto *gvolume = gvolumePtr.get();
 
                // Try to build; if dependencies are missing, remember it for the next iteration.
                if (!build_g4volume(gvolume, objectsFactory)) {
                    // Only track volumes that are meant to exist; nonexistent volumes are skipped quietly.
                    if (gvolume->getExistence()) {
                        log->info(2, " >> adding volumeName <", volumeName, "> to the list of remaining volumes");
                        thisIterationRemainingVolumes.push_back(gvolume);
                    }
                }
            }
 
            // Diagnostic listing of the volumes that could not be built due to missing mothers.
            if (!thisIterationRemainingVolumes.empty()) {
                log->info(2, "G4World: ", systemName, " : ",
                          thisIterationRemainingVolumes.size(),
                          " remaining motherless g4volumes to be built:");
                for (auto *gvolumeLeft: thisIterationRemainingVolumes) {
                    log->info(2, "G4World: ", gvolumeLeft->getName(),
                              " with mother <", gvolumeLeft->getG4MotherName(), "> ");
                }
            }
        }
 
        // Dependency-stall detection: error only when the remaining count fails to strictly
        // decrease across iterations (a strictly smaller count means progress was made).
        if (previousRemainingVolumes != 0 && !thisIterationRemainingVolumes.empty() &&
            thisIterationRemainingVolumes.size() >= previousRemainingVolumes) {
            for (auto *gvolumeLeft: thisIterationRemainingVolumes) {
                log->warning(" >> ", gvolumeLeft->getName(),
                             " with mother <", gvolumeLeft->getG4MotherName(), "> not built");
            }
            log->error(ERR_G4DEPENDENCIESNOTSOLVED,
                       "dependencies are not being resolved: their number should diminish. "
                       "Above are the outstanding gvolumes");
        }
        previousRemainingVolumes = thisIterationRemainingVolumes.size();
    } while (!thisIterationRemainingVolumes.empty());
 
    // Phase 5: build optical surfaces (mirrors), now that all logical/physical volumes exist.
    buildOpticalSurfaces(gsystemMap);
 
    // Optional diagnostic output: list known materials from the Geant4 NIST manager.
    if (gopts->getSwitch("showPredefinedMaterials")) { G4NistManager::Instance()->ListMaterials("all"); }
 
    // Optional diagnostic output: print materials used in the simulation.
    if (gopts->getSwitch("printSystemsMaterials")) {
        auto matTable = (G4MaterialTable *) G4Material::GetMaterialTable();
        for (auto thisMat: *matTable) {
            log->info(0, 2, "G4World: GEMC Material: <", thisMat->GetName(), ">, density: ",
                      thisMat->GetDensity() / (CLHEP::g / CLHEP::cm3), "g/cm3");
 
            // Print each component; negative/zero values mean "fractional mass", positive means "number of atoms".
            for (auto &[material, component]: thisMat->GetMatComponents()) {
                if (component > 0.0) {
                    log->info(0, "element", material->GetName(), "number of atoms: ", component);
                } else { log->info(0, "element", material->GetName(), "fractional mass: ", component); }
            }
        }
    }
}
 
/*──────────────────────── look-ups ──────────────────────────*/
 
const G4Volume *G4World::getG4Volume(const std::string &volumeName) const {
    auto it = g4volumesMap.find(volumeName);
    return (it != g4volumesMap.end()) ? it->second : nullptr;
}
 
void G4World::setFieldManagerForVolume(const std::string &volumeName,
                                       G4FieldManager *fm,
                                       bool forceToAllDaughters) {
    auto it = g4volumesMap.find(volumeName);
    if (it != g4volumesMap.end()) it->second->setFieldManager(fm, forceToAllDaughters);
}
 
// ---- g4FactoryNameFromSystemFactory -----------------------------------------------------------
std::string G4World::g4FactoryNameFromSystemFactory(const std::string &factory) const {
    // Map GEMC system factory labels to g4system object factory labels.
    if (factory == GSYSTEMASCIIFACTORYLABEL ||
        factory == GSYSTEMSQLITETFACTORYLABEL ||
        factory == GSYSTEMMYSQLTFACTORYLABEL) { return G4SYSTEMNATFACTORY; } else if (
        factory == GSYSTEMCADTFACTORYLABEL) { return G4SYSTEMCADFACTORY; } else {
        log->error(ERR_G4SYSTEMFACTORYNOTFOUND,
                   "gsystemFactory factory <", factory, "> is not mapped to any G4SystemFactory");
    }
}
 
void G4World::createG4SystemFactory(const std::shared_ptr<GOptions> &gopts,
                                    SystemMap *gsystemsMap,
                                    const std::string &backup_material,
                                    int check_overlaps) {
    // Instantiate a manager used to register and create factories.
    GManager manager(gopts);
 
    // Creating the native factory no matter what (it is the default for ASCII/SQLite/MySQL systems).
    log->info(2, "G4World: registering default factory <", G4SYSTEMNATFACTORY, ">");
    manager.RegisterObjectFactory<G4NativeSystemFactory>(G4SYSTEMNATFACTORY, gopts);
 
    // Register factories based on the system factory label, then create/initialize them lazily.
    for (auto &[gsystemName, gsystem]: *gsystemsMap) {
        std::string factory = gsystem->getFactoryName();
        std::string g4Factory = g4FactoryNameFromSystemFactory(factory);
 
        log->info(2, "G4World: creating factory <", g4Factory, "> to for system <", gsystemName, ">");
 
        // Register needed factory types:
        // this will always be false for the default native label because it was registered above.
        if (factory == GSYSTEMASCIIFACTORYLABEL || factory == GSYSTEMSQLITETFACTORYLABEL ||
            factory == GSYSTEMMYSQLTFACTORYLABEL) {
            if (g4systemFactory.find(g4Factory) == g4systemFactory.end()) {
                manager.RegisterObjectFactory<G4NativeSystemFactory>(g4Factory, gopts);
            }
        } else if (factory == GSYSTEMCADTFACTORYLABEL) {
            if (g4systemFactory.find(GSYSTEMCADTFACTORYLABEL) == g4systemFactory.end()) {
                manager.RegisterObjectFactory<G4CadSystemFactory>(g4Factory, gopts);
            }
        }
 
        // Create and initialize the concrete factory instance once per label.
        if (g4systemFactory.find(g4Factory) == g4systemFactory.end()) {
            g4systemFactory[g4Factory] = manager.CreateObject<G4ObjectsFactory>(g4Factory);
            g4systemFactory[g4Factory]->initialize_context(check_overlaps, backup_material);
        }
    }
}
 
void G4World::buildMaterials(SystemMap *system_map) {
    // Build materials across all systems. Some materials may depend on other materials/elements,
    // so we iterate until all dependencies are resolved or the resolution stalls.
    std::vector<GMaterial *> thisIterationRemainingMaterials;
    unsigned long previousRemainingMaterials = 0;
    do {
        thisIterationRemainingMaterials.clear();
 
        for (const auto &[systemName, system]: *system_map) {
            // Loop over the material map in each system and attempt to build each material.
            for (const auto &[gmaterialName, gmaterialPtr]: system->getGMaterialMap()) {
                if (createG4Material(gmaterialPtr) == false) {
                    thisIterationRemainingMaterials.push_back(gmaterialPtr.get());
                }
            }
        }
 
        // Dependency-stall detection for material building: error only when the remaining
        // count fails to strictly decrease across iterations.
        if (previousRemainingMaterials != 0 && !thisIterationRemainingMaterials.empty() &&
            thisIterationRemainingMaterials.size() >= previousRemainingMaterials) {
            for (auto &gmaterialLeft: thisIterationRemainingMaterials) { log->warning(gmaterialLeft->getName()); }
            log->error(ERR_G4DEPENDENCIESNOTSOLVED,
                       "Dependencies are not being resolved: their number should diminish. Above are the Outstanding gmaterials");
        }
        previousRemainingMaterials = thisIterationRemainingMaterials.size();
    } while (!thisIterationRemainingMaterials.empty());
}
 
bool G4World::build_g4volume(const GVolume *s, G4ObjectsFactory *objectsFactory) {
    log->info(2, "G4World: using factory <", objectsFactory->className(),
              "> to build g4volume <", s->getG4Name(), ">");
 
    return objectsFactory->build_g4volume(s, &g4volumesMap);
}