Saving in Multiplayer Games

1class GameObject {
2  int OwnerId; // Player with authority
3  Vector2 Position;
4  bool IsDirty; // Track if object needs saving
5
6public:
7  bool HasAuthority(int PlayerId) const {
8    return PlayerId == OwnerId;
9  }
10
11  void UpdatePosition(const Vector2& NewPos,
12                      int RequestingPlayer) {
13    if (HasAuthority(RequestingPlayer)) {
14      Position = NewPos;
15      IsDirty = true;
16      BroadcastUpdate(); // Tell other players
17    }
18  }
19};

1struct Modification {
2  int PlayerId;
3  int ObjectId;
4  // Use server time for consistency
5  int Timestamp;
6  Vector2 NewPosition;
7};
8
9class ConflictResolver {
10 public:
11  void HandleModification(
12    const Modification& Mod
13  ) {
14    auto& Object = GetObject(Mod.ObjectId);
15
16    if (Mod.Timestamp > Object.LastModified) {
17      // Accept newer modification
18      Object.Position = Mod.NewPosition;
19      Object.LastModified = Mod.Timestamp;
20    }
21  }
22};

1class GameServer {
2  std::unordered_map<int, GameObject> Objects;
3
4  void SaveGameState() {
5    GameState State;
6
7    for (const auto& [Id, Object] : Objects) {
8      if (Object.IsDirty) {
9        State.ModifiedObjects.push_back(Object);
10      }
11    }
12
13    if (!State.ModifiedObjects.empty()) {
14      WriteToDatabase(State);
15    }
16  }
17};