Using File IO to Save and Load Games - Learn C++ for Game Development - page 248

virtual void OnSave(std::ofstream & file);
virtual void OnLoad(std::ifstream & file);
Pointer GetPointer() const { return m_pointer; }
};
Now any time any part of our code wishes to store a shared_ptr to a Serializable object, it should
be retrieving the pointer from a shared place. The easiest place for this to be is on the object itself,
which is registered with the SerializationManager via its unique ID.
The Room class has to save and load the state of its dynamic options. Listing 24-15 shows the save
and load methods.
Listing 24-15. Room::OnSave and Room::OnLoad
void Room::OnSave(std::ofstream& file)
{
file << m_dynamicOptions.size();
file << std::endl;
for (auto& dynamicOption : m_dynamicOptions)
{
file << dynamicOption->GetId();
file << std::endl;
}
}
void Room::OnLoad(std::ifstream& file)
{
m_dynamicOptions.clear();
unsigned int numDynamicOptions;
file >> numDynamicOptions;
if (numDynamicOptions > 0)
{
for (unsigned int i = 0; i < numDynamicOptions; ++i)
{
unsigned int optionId;
file >> optionId;
Option* pOption =
dynamic_cast<Option*>(
SerializationManager::GetSingleton().GetSerializable(optionId));
if (pOption)
{
Option::Pointer sharedPointer = pOption->GetPointer();
m_dynamicOptions.emplace_back{ sharedPointer };
}
}
}
}