RA tweaks

Core/GameEngine/Source/GameNetwork/ConnectionManager.cpp

@@ -1278,13 +1278,102 @@ void ConnectionManager::updateRunAhead(Int oldRunAhead, Int frameRate, Bool didS
 			// TheSuperHackers @bugfix Mauller 21/08/2025 calculate the runahead so it always follows the latency
 			// The runahead should always be rounded up to the next integer value to prevent variations in latency from causing stutter
 			// The network slack pushes the runahead up to the next value when the latency is within the slack percentage of the current runahead
-			const Real runAheadSlackScale = 1.0f + ((Real)TheGlobalData->m_networkRunAheadSlack / 100.0f);
 
-			Int newRunAhead = ceilf((getMaximumLatency()) * runAheadSlackScale * (Real)minFps);
+			Real configuredSlack = (Real)TheGlobalData->m_networkRunAheadSlack / 100.0f;
+
+			Real effectiveSlack = configuredSlack;
+
+#if defined(GENERALS_ONLINE)
+			if (TheNGMPGame != nullptr)
+			{
+				// dynamic slack based on jitter
+				NetworkMesh* pMesh = NGMP_OnlineServicesManager::GetNetworkMesh();
+				if (pMesh != nullptr)
+				{
+					// 1) Current max latency (RTT)
+					int maxLatMs = pMesh->getMaximumLatency();
+
+					// 2) Compute worst-case jitter (max - min) across recent history
+					int jitterMs = 0;
+
+					auto& connections = pMesh->GetAllConnections();
+					for (auto& kvPair : connections)
+					{
+						PlayerConnection& conn = kvPair.second;
+
+						if (conn.m_vecLatencyHistory.size() > 1)
+						{
+							int minL = INT_MAX;
+							int maxL = 0;
+
+							for (int l : conn.m_vecLatencyHistory)
+							{
+								if (l < minL) minL = l;
+								if (l > maxL) maxL = l;
+							}
+
+							int span = maxL - minL;
+							if (span > jitterMs)
+							{
+								jitterMs = span;
+							}
+						}
+					}
+
+					// 3) Convert jitter to a 0–1+ ratio relative to latency
+					Real jitterRatio = 0.0f;
+					if (maxLatMs > 0)
+					{
+						jitterRatio = (Real)jitterMs / (Real)maxLatMs;
+					}
+
+					// 4) Map jitter ratio into a slack range based on latency
+					//    Lower latency: tighter slack
+					//    Higher latency: allow more slack to hide jitter
+					Real minSlack = 0.20f;
+					Real maxSlack = 0.60f;
+
+					if (maxLatMs > 300)
+					{
+						// At high RTT, allow more headroom
+						minSlack = 0.35f;
+						maxSlack = 0.90f;
+					}
+					else if (maxLatMs > 200)
+					{
+						// Medium-high latency (200–300 ms)
+						minSlack = 0.30f;
+						maxSlack = 0.80f;
+					}
+
+					// Clamp jitterRatio to [0,1] when mapping
+					if (jitterRatio < 0.0f) jitterRatio = 0.0f;
+					if (jitterRatio > 1.0f) jitterRatio = 1.0f;
+
+					Real dynamicSlack = minSlack + (maxSlack - minSlack) * jitterRatio;
+
+					// ignore service slack and use our own dynamic slack
+					effectiveSlack = dynamicSlack;
+				}
+			}
+#endif
+
+			const Real runAheadSlackScale = 1.0f + effectiveSlack;
+
+			Int newRunAhead = ceilf(getMaximumLatency() * runAheadSlackScale * (Real)minFps);
 
 			// TheSuperHackers @info if the runahead goes below 3 logic frames it can start to introduce stutter
 			// We also limit the upper range of the runahead to prevent it getting out of hand
-			newRunAhead = clamp<Int>(MIN_RUNAHEAD, newRunAhead, MAX_FRAMES_AHEAD / 2);
+			Int minRunAheadForClamp = MIN_RUNAHEAD;
+
+#if defined(GENERALS_ONLINE)
+			if (TheNGMPGame != nullptr)
+			{
+				minRunAheadForClamp = 3;
+			}
+#endif
+
+			newRunAhead = clamp<Int>(minRunAheadForClamp, newRunAhead, MAX_FRAMES_AHEAD / 2);
 
 			NetRunAheadCommandMsg* msg = newInstance(NetRunAheadCommandMsg);
 			msg->setPlayerID(m_localSlot);