From 92a74808feafed93bd194e54cee3bc51f03784f7 Mon Sep 17 00:00:00 2001
From: Regalis <regalis@undertowgames.com>
Date: Tue, 18 Apr 2017 21:37:23 +0300
Subject: [PATCH] Fix to oxygen distribution logic: gaps used to move a fixed
 amount of oxygen between hulls every frame, causing the oxygen levels to
 fluctuate constantly. While it wasn't noticeable in regular sized hulls,
 smaller hulls created excessive amounts of NetworkEvents due to large
 fluctuations in the oxygen percentage.

Now the gaps make the oxygen percentages settle to the average value, and hulls have a minimum delay of 0.5s between the creation of NetworkEvents.
---
 Subsurface/Source/Map/Gap.cs  |  7 +++++--
 Subsurface/Source/Map/Hull.cs | 23 +++++++++++++++--------
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/Subsurface/Source/Map/Gap.cs b/Subsurface/Source/Map/Gap.cs
index f7b23a11b..e2aa312f2 100644
--- a/Subsurface/Source/Map/Gap.cs
+++ b/Subsurface/Source/Map/Gap.cs
@@ -629,9 +629,12 @@ namespace Barotrauma
 
             float totalOxygen = hull1.Oxygen + hull2.Oxygen;
             float totalVolume = (hull1.FullVolume + hull2.FullVolume);
+            
+            float deltaOxygen = (totalOxygen * hull1.FullVolume / totalVolume) - hull1.Oxygen;
+            deltaOxygen = MathHelper.Clamp(deltaOxygen, -Hull.OxygenDistributionSpeed, Hull.OxygenDistributionSpeed);
 
-            hull1.Oxygen += Math.Sign(totalOxygen * hull1.FullVolume / (totalVolume) - hull1.Oxygen) * Hull.OxygenDistributionSpeed;
-            hull2.Oxygen += Math.Sign(totalOxygen * hull2.FullVolume / (totalVolume) - hull2.Oxygen) * Hull.OxygenDistributionSpeed;            
+            hull1.Oxygen += deltaOxygen;
+            hull2.Oxygen -= deltaOxygen;            
         }
 
         public static Gap FindAdjacent(List<Gap> gaps, Vector2 worldPos, float allowedOrthogonalDist)
diff --git a/Subsurface/Source/Map/Hull.cs b/Subsurface/Source/Map/Hull.cs
index 5708719ea..94cbdec9b 100644
--- a/Subsurface/Source/Map/Hull.cs
+++ b/Subsurface/Source/Map/Hull.cs
@@ -15,6 +15,8 @@ namespace Barotrauma
 
     class Hull : MapEntity, IPropertyObject, IServerSerializable
     {
+        const float NetworkUpdateInterval = 0.5f;
+
         public static List<Hull> hullList = new List<Hull>();
         private static List<EntityGrid> entityGrids = new List<EntityGrid>();
         public static List<EntityGrid> EntityGrids
@@ -74,7 +76,7 @@ namespace Barotrauma
         float[] rightDelta;
 
         private float lastSentVolume, lastSentOxygen;
-        private float lastNetworkUpdate;
+        private float sendUpdateTimer;
         
         public List<Gap> ConnectedGaps;
 
@@ -361,8 +363,6 @@ namespace Barotrauma
                     entityGrid.RemoveEntity(this);
                 }
             }
-
-
         }
 
         public void AddFireSource(FireSource fireSource)
@@ -460,7 +460,17 @@ namespace Barotrauma
             if (Math.Abs(lastSentVolume - volume) > FullVolume * 0.1f ||
                 Math.Abs(lastSentOxygen - OxygenPercentage) > 5f)
             {
-                if (GameMain.Server != null) GameMain.Server.CreateEntityEvent(this); 
+                if (GameMain.Server != null)
+                {
+                    sendUpdateTimer -= deltaTime;
+                    if (sendUpdateTimer < 0.0f)
+                    {
+                        GameMain.Server.CreateEntityEvent(this);
+                        lastSentVolume = volume;
+                        lastSentOxygen = OxygenPercentage;
+                        sendUpdateTimer = NetworkUpdateInterval;
+                    }
+                }
             }
 
             if (!update)
@@ -622,7 +632,7 @@ namespace Barotrauma
                     isHighlighted ? Color.LightBlue * 0.5f : Color.Red * 0.5f, true, 0, (int)Math.Max((1.5f / GameScreen.Selected.Cam.Zoom), 1.0f));
             }
         }
-        
+                
         public void Render(GraphicsDevice graphicsDevice, Camera cam)
         {
             if (renderer.PositionInBuffer > renderer.vertices.Length - 6) return;
@@ -842,9 +852,6 @@ namespace Barotrauma
                     message.WriteRangedSingle(MathHelper.Clamp(fireSource.Size.X / rect.Width, 0.0f, 1.0f), 0, 1.0f, 8);
                 }
             }
-
-            lastSentVolume = volume;
-            lastSentOxygen = OxygenPercentage;
         }
 
         public void ClientRead(ServerNetObject type, NetBuffer message, float sendingTime)