From fbf82040fafad43fc32f7ade6754136f16376587 Mon Sep 17 00:00:00 2001
From: Adam Mitchell <adammitchelldev@gmail.com>
Date: Thu, 14 Jan 2021 09:29:56 +0000
Subject: [PATCH] Improve smoothness in tickrate

---
 OpenRA.Game/Game.cs                 | 12 +++++++++---
 OpenRA.Game/Network/OrderManager.cs |  4 ++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/OpenRA.Game/Game.cs b/OpenRA.Game/Game.cs
index ee417049c6d6..ec8c19bdd645 100644
--- a/OpenRA.Game/Game.cs
+++ b/OpenRA.Game/Game.cs
@@ -35,7 +35,7 @@ public static class Game
 		public const int NewNetcodeNetTickScale = 1; // Net tick every world frame
 		public const int Timestep = 40;
 		public const int TimestepJankThreshold = 250; // Don't catch up for delays larger than 250ms
-		public const double NetCatchupFactor = 0.25;
+		public const double NetCatchupFactor = 0.1;
 		public static InstalledMods Mods { get; private set; }
 		public static ExternalMods ExternalMods { get; private set; }
 
@@ -600,6 +600,8 @@ static void InnerLogicTick(OrderManager orderManager)
 				worldTimestep = Timestep;
 			else if (world.IsLoadingGameSave)
 				worldTimestep = 1;
+			else if (orderManager.IsStalling)
+				worldTimestep = 1;
 			else if (orderManager.CatchUpFrames > 0)
 				worldTimestep = (int)Math.Floor(world.Timestep / (1.0 + NetCatchupFactor * orderManager.CatchUpFrames)); // Smooth catchup
 			else
@@ -805,8 +807,11 @@ static void Loop()
 				var maxFramerate = Settings.Graphics.CapFramerate ? Settings.Graphics.MaxFramerate.Clamp(1, 1000) : 1000;
 				var renderInterval = 1000 / maxFramerate;
 
+				if (OrderManager.IsStalling)
+					logicInterval = 1;
+
 				// TODO: limit rendering if we are taking too long to catch up
-				if (OrderManager.CatchUpFrames > 0)
+				else if (OrderManager.CatchUpFrames > 0)
 					logicInterval = (int)Math.Floor(logicInterval / (1.0 + NetCatchupFactor * OrderManager.CatchUpFrames));
 
 				// Tick as fast as possible while restoring game saves, capping rendering at 5 FPS
@@ -835,7 +840,8 @@ static void Loop()
 						LogicTick();
 
 						// Force at least one render per tick during regular gameplay
-						if (!(OrderManager.CatchUpFrames > 0) && OrderManager.World != null && !OrderManager.World.IsLoadingGameSave && !OrderManager.World.IsReplay)
+						// TODO: Have OrderManager tell us when we should force render
+						if (!OrderManager.IsStalling && !(OrderManager.CatchUpFrames > 2) && OrderManager.World != null && !OrderManager.World.IsLoadingGameSave && !OrderManager.World.IsReplay)
 							renderBeforeNextTick = true;
 					}
 
diff --git a/OpenRA.Game/Network/OrderManager.cs b/OpenRA.Game/Network/OrderManager.cs
index c3d0c0c17aae..0288c9aeaebc 100644
--- a/OpenRA.Game/Network/OrderManager.cs
+++ b/OpenRA.Game/Network/OrderManager.cs
@@ -47,6 +47,7 @@ public sealed class OrderManager : IDisposable
 		public int OrderLatency; // Set during lobby by a "SyncInfo" packet, see UnitOrders
 		public int NextOrderFrame;
 		public int CatchUpFrames { get; private set; }
+		public bool IsStalling { get; private set; }
 
 		public long LastTickTime = Game.RunTime;
 
@@ -197,6 +198,7 @@ void CheckSync(byte[] packet)
 
 		void CompensateForLatency()
 		{
+			// NOTE: subtract 1 because we are only interested in *excess* frames
 			var catchUpNetFrames = frameData.BufferSizeForClient(Connection.LocalClientId) - 1;
 			if (catchUpNetFrames < 0)
 				catchUpNetFrames = 0;
@@ -309,6 +311,8 @@ public bool TryTick()
 				willTick = frameData.IsReadyForFrame();
 				if (willTick)
 					ProcessOrders();
+
+				IsStalling = !willTick;
 			}
 
 			if (willTick)