From 7625d048073d7ab4a485327416636b03e7f16400 Mon Sep 17 00:00:00 2001
From: Joonas Rikkonen <poe.regalis@gmail.com>
Date: Sun, 3 Sep 2017 13:11:53 +0300
Subject: [PATCH] Fixed exceptions during level generation if two tunnel nodes
 happen to be placed at the same position

---
 Barotrauma/BarotraumaShared/Source/Map/Levels/Level.cs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/Barotrauma/BarotraumaShared/Source/Map/Levels/Level.cs b/Barotrauma/BarotraumaShared/Source/Map/Levels/Level.cs
index 4a3d45a50..9ec3fd5e9 100644
--- a/Barotrauma/BarotraumaShared/Source/Map/Levels/Level.cs
+++ b/Barotrauma/BarotraumaShared/Source/Map/Levels/Level.cs
@@ -752,11 +752,16 @@ namespace Barotrauma
             while (currLength < tunnelLength)
             {
                 Vector2 dir = Rand.Vector(1.0f, Rand.RandSync.Server);
-
+                                
                 dir.Y += Math.Sign(tunnelNodes[tunnelNodes.Count - 1].Y - Size.Y / 2) * 0.5f;
                 if (tunnelNodes.Count > 1)
                 {
-                    dir += Vector2.Normalize(tunnelNodes[tunnelNodes.Count - 1] - tunnelNodes[tunnelNodes.Count - 2]) * 0.5f;
+                    //keep heading roughly in the same direction as the previous nodes
+                    Vector2 prevNodeDiff = tunnelNodes[tunnelNodes.Count - 1] - tunnelNodes[tunnelNodes.Count - 2];
+                    if (prevNodeDiff != Vector2.Zero)
+                    {
+                        dir += Vector2.Normalize(tunnelNodes[tunnelNodes.Count - 1] - tunnelNodes[tunnelNodes.Count - 2]) * 0.5f;
+                    }
                 }
 
                 float avoidDist = 20000.0f;