Fix (or a workaround) to characters teleporting inside/through colliders when leaving a sub (see #552). Gaps do a raycast out from the sub to see if there are obstacles outside, and if so, ragdolls place a collider at the corresponding position inside the sub. The collider is simply a straight axis-aligned line atm, so it doesn't work accurately with sloped ice/submarine walls, but does prevent the ragdoll from ending up inside the obstacles. TODO: use a few edges to approximate the shape of the obstacles more closely?

Barotrauma/BarotraumaShared/Source/Map/Gap.cs

@@ -1,4 +1,5 @@
 using Barotrauma.Items.Components;
+using FarseerPhysics;
 using Microsoft.Xna.Framework;
 using System;
 using System.Collections.Generic;
@@ -13,6 +14,8 @@ namespace Barotrauma
 
         public static bool ShowGaps = true;
 
+        const float OutsideColliderRaycastInterval = 0.1f;
+
         public readonly bool IsHorizontal;
         
         //a value between 0.0f-1.0f (0.0 = closed, 1.0f = open)
@@ -26,12 +29,18 @@ namespace Barotrauma
         private float lowerSurface;
         
         private Vector2 lerpedFlowForce;
-
+        
         //if set to true, hull connections of this gap won't be updated when changes are being done to hulls
         public bool DisableHullRechecks;
         
         //can ambient light get through the gap even if it's not open
         public bool PassAmbientLight;
+        
+        //position of a collider outside the gap (for example an ice wall next to the sub)
+        //used by ragdolls to prevent them from ending up inside colliders when teleporting out of the sub
+        private Vector2? outsideColliderPos;
+        private Vector2? outsideColliderNormal;
+        private float outsideColliderRaycastTimer;
 
         public float Open
         {
@@ -191,6 +200,8 @@ namespace Barotrauma
         {
             flowForce = Vector2.Zero;
 
+            outsideColliderRaycastTimer -= deltaTime;
+
             if (open == 0.0f || linkedTo.Count == 0)
             {
                 lerpedFlowForce = Vector2.Zero;
@@ -505,7 +516,51 @@ namespace Barotrauma
                     hull1.LethalPressure += (Submarine != null && Submarine.AtDamageDepth) ? 100.0f * deltaTime : 10.0f * deltaTime;
                 }
             }
+        }
 
+        public bool GetOutsideCollider(out Vector2? simPosition, out Vector2? normal)
+        {
+            simPosition = null;
+            normal = null;
+
+            if (IsRoomToRoom || Submarine == null || open <= 0.0f) return false;
+
+            if (outsideColliderRaycastTimer <= 0.0f)
+            {
+                UpdateOutsideColliderPos((Hull)linkedTo[0]);
+                outsideColliderRaycastTimer = OutsideColliderRaycastInterval;
+            }
+
+            simPosition = outsideColliderPos;
+            normal = outsideColliderNormal;
+            return simPosition != null;
+        }
+
+        private void UpdateOutsideColliderPos(Hull hull)
+        {
+            outsideColliderNormal = null;
+            outsideColliderPos = null;
+
+            if (Submarine == null) return;
+
+            Vector2 rayDir;
+            if (IsHorizontal)
+            {
+                rayDir = new Vector2(Math.Sign(rect.Center.X - hull.Rect.Center.X), 0);
+            }
+            else
+            {
+                rayDir = new Vector2(0, Math.Sign((rect.Y - rect.Height / 2) - (hull.Rect.Y - hull.Rect.Height / 2)));
+            }
+
+            Vector2 rayStart = ConvertUnits.ToSimUnits(WorldPosition);
+            Vector2 rayEnd = rayStart + rayDir * 500.0f;
+
+            if (Submarine.CheckVisibility(rayStart, rayEnd) != null)
+            {
+                outsideColliderNormal = -rayDir;
+                outsideColliderPos = Submarine.LastPickedPosition;
+            }
         }
 
         private void UpdateOxygen()

Barotrauma/BarotraumaShared/Source/Map/Submarine.cs

@@ -75,6 +75,7 @@ namespace Barotrauma
 
         private static Vector2 lastPickedPosition;
         private static float lastPickedFraction;
+        private static Vector2 lastPickedNormal;
 
         private Md5Hash hash;
         
@@ -120,6 +121,11 @@ namespace Barotrauma
             get { return lastPickedFraction; }
         }
 
+        public static Vector2 LastPickedNormal
+        {
+            get { return lastPickedNormal; }
+        }
+
         public bool Loading
         {
             get;
@@ -593,6 +599,7 @@ namespace Barotrauma
             }
 
             float closestFraction = 1.0f;
+            Vector2 closestNormal = Vector2.Zero;
             Body closestBody = null;
             GameMain.World.RayCast((fixture, point, normal, fraction) =>
             {
@@ -616,6 +623,7 @@ namespace Barotrauma
                 if (fraction < closestFraction)
                 {
                     closestFraction = fraction;
+                    closestNormal = normal;
                     if (fixture.Body != null) closestBody = fixture.Body;
                 }
                 return fraction;
@@ -624,6 +632,7 @@ namespace Barotrauma
 
             lastPickedPosition = rayStart + (rayEnd - rayStart) * closestFraction;
             lastPickedFraction = closestFraction;
+            lastPickedNormal = closestNormal;
             
             return closestBody;
         }
@@ -636,6 +645,7 @@ namespace Barotrauma
         {
             Body closestBody = null;
             float closestFraction = 1.0f;
+            Vector2 closestNormal = Vector2.Zero;
 
             if (Vector2.Distance(rayStart, rayEnd) < 0.01f)
             {
@@ -664,6 +674,7 @@ namespace Barotrauma
                 {
                     closestBody = fixture.Body;
                     closestFraction = fraction;
+                    closestNormal = normal;
                 }
                 return closestFraction;
             }
@@ -672,6 +683,7 @@ namespace Barotrauma
 
             lastPickedPosition = rayStart + (rayEnd - rayStart) * closestFraction;
             lastPickedFraction = closestFraction;
+            lastPickedNormal = closestNormal;
             return closestBody;
         }