synchronization-algorithms

name	synchronization-algorithms
version	2.0.0
description	Network synchronization, lag compensation, client prediction, and state consistency for responsive multiplayer games.
sasmp_version	1.3.0
bonded_agent	05-networking-multiplayer
bond_type	PRIMARY_BOND
parameters	[{"name":"technique","type":"string","required":false,"validation":{"enum":["prediction","interpolation","reconciliation","rollback","lockstep"]}},{"name":"game_type","type":"string","required":false,"validation":{"enum":["fps","fighting","rts","mmo","racing"]}}]
retry_policy	{"enabled":true,"max_attempts":5,"backoff":"exponential","jitter":true}
observability	{"log_events":["start","complete","error","desync"],"metrics":["prediction_error_ms","rollback_count","resync_frequency"]}

Multiplayer Synchronization

Synchronization Techniques

┌─────────────────────────────────────────────────────────────┐
│                    SYNC TECHNIQUES OVERVIEW                  │
├─────────────────────────────────────────────────────────────┤
│  CLIENT PREDICTION:                                          │
│  → Execute input locally before server confirms             │
│  → Feels responsive, requires reconciliation               │
│  Best for: FPS, action games                                │
├─────────────────────────────────────────────────────────────┤
│  INTERPOLATION:                                              │
│  → Display positions between known states                   │
│  → Smooth visuals, adds latency                            │
│  Best for: Other players, NPCs                              │
├─────────────────────────────────────────────────────────────┤
│  ROLLBACK NETCODE:                                           │
│  → Rewind game state on correction                          │
│  → Re-simulate with corrected data                          │
│  Best for: Fighting games, precise timing                   │
├─────────────────────────────────────────────────────────────┤
│  LOCKSTEP:                                                   │
│  → All clients advance together                             │
│  → Deterministic, waits for slowest                        │
│  Best for: RTS, turn-based                                  │
└─────────────────────────────────────────────────────────────┘

Client Prediction & Reconciliation

PREDICTION FLOW:
┌─────────────────────────────────────────────────────────────┐
│  Frame N:                                                    │
│  1. Capture input                                           │
│  2. Predict result locally (immediate response)            │
│  3. Store input + predicted state                          │
│  4. Send input to server                                   │
│                                                              │
│  Frame N+RTT:                                                │
│  5. Receive server state for Frame N                       │
│  6. Compare with stored prediction                         │
│  7. If mismatch: RECONCILE                                 │
│     a. Snap to server state                                │
│     b. Re-apply all inputs since Frame N                   │
│     c. Smooth correction to avoid visual pop               │
└─────────────────────────────────────────────────────────────┘

// ✅ Production-Ready: Prediction Buffer
public class PredictionBuffer
{
    private const int BUFFER_SIZE = ;
      PredictionEntry[] _buffer =  PredictionEntry[BUFFER_SIZE];

    
    {
         index = ()(tick % BUFFER_SIZE);
        _buffer[index] =  PredictionEntry
        {
            Tick = tick,
            Input = input,
            PredictedState = predictedState
        };
    }

    
    {
         index = ()(serverTick % BUFFER_SIZE);
         entry = _buffer[index];

         (entry.Tick != serverTick) ; 

         error = Vector3.Distance(entry.PredictedState.Position, serverState.Position);
         (error < ) ; 

        
        PlayerState currentState = serverState;

        
         ( t = serverTick + ; t <= CurrentTick; t++)
        {
             idx = ()(t % BUFFER_SIZE);
             (_buffer[idx].Tick == t)
            {
                currentState = SimulateInput(currentState, _buffer[idx].Input);
            }
        }

        
        ApplyCorrectedState(currentState);
    }
}