std::set<Entity*> EntityManager::getEntities(const Filter& filter)
{
std::set<Entity*> entities;
if (!filter.getOne().empty())
{
for (auto& iter : filter.getOne())
getEntities(iter, entities);
}
if (!filter.getAll().empty())
{
auto iter = filter.getAll().begin();
Type typeId = *iter;
std::set<Entity*> suspects;
getEntities(typeId, suspects);
if (!suspects.empty())
{
iter++;
for (; iter != filter.getAll().end(); ++iter)
{
typeId = *iter;
std::set<Entity*> ents;
getEntities(typeId, ents);
if (ents.empty())
{
suspects.clear();
break;
}
std::set<Entity*> newSuspects;
for (auto& siter : suspects)
{
if (ents.find(siter) != ents.end())
newSuspects.insert(siter);
}
suspects = newSuspects;
}
}
// if there's no "one of" requirement, add all these entities
if (filter.getOne().empty())
entities = suspects;
else
{
std::set<Entity*> newEntities;
// otherwise, we have to check that the entity exists in both sets
for (auto iter = entities.begin(); iter != entities.end(); ++iter)
{
if (suspects.end() != suspects.find(*iter))
newEntities.insert(*iter);
}
entities = newEntities;
}
}
if (!filter.getExcept().empty())
{
std::set<Entity*> excluded;
// add all entities that don't have those things in
for (auto iter = m_componentTypeToEntities.begin(); iter != m_componentTypeToEntities.end(); ++iter)
{
for (auto fIter = filter.getExcept().begin(); fIter != filter.getExcept().end(); ++fIter)
{
if (fIter->isDerivedFrom(iter->first))
excluded.insert(iter->second.begin(), iter->second.end());
}
}
if (filter.getAll().empty() && filter.getOne().empty())
entities = excluded;
else
{
std::set<Entity*> newEntities;
// otherwise, we have to check that the entity exists in both sets
for (auto iter = entities.begin(); iter != entities.end(); ++iter)
{
if (excluded.end() != excluded.find(*iter))
newEntities.insert(*iter);
}
entities = newEntities;
}
}
return entities;
}
