Renamed project folders from Subsurface to Barotrauma

Barotrauma/Source/Characters/AI/AIController.cs

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+using Lidgren.Network;
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+
+namespace Barotrauma
+{
+    class AIController : ISteerable
+    {
+
+        public enum AiState { None, Attack, GoTo, Escape }
+        public enum SteeringState { Wander, Seek, Escape }
+
+        public bool Enabled;
+
+        public readonly Character Character;
+        
+        protected AiState state;
+
+        protected SteeringManager steeringManager;
+
+        public SteeringManager SteeringManager
+        {
+            get { return steeringManager; }
+        }
+
+        public Vector2 Steering
+        {
+            get { return Character.AnimController.TargetMovement; }
+            set { Character.AnimController.TargetMovement = value; }
+        }
+        
+        public Vector2 SimPosition
+        {
+            get { return Character.SimPosition; }
+        }
+
+        public Vector2 WorldPosition
+        {
+            get { return Character.WorldPosition; }
+        }
+
+        public Vector2 Velocity
+        {
+            get { return Character.AnimController.Collider.LinearVelocity; }
+        }
+
+        public AiState State
+        {
+            get { return state; }
+            set { state = value; }
+        }
+
+        public AIController (Character c)
+        {
+            Character = c;
+
+            Enabled = true;
+        }
+
+        public virtual void DebugDraw(SpriteBatch spriteBatch) { }
+
+        public virtual void OnAttacked(IDamageable attacker, float amount) { }
+
+        public virtual void SelectTarget(AITarget target) { }
+
+        public virtual void Update(float deltaTime) { }
+
+        //protected Structure lastStructurePicked;
+        
+    }
+}

Barotrauma/Source/Characters/AI/AITarget.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Collections.Generic;
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+
+namespace Barotrauma
+{
+    class AITarget
+    {
+        public static bool ShowAITargets;
+
+        public static List<AITarget> List = new List<AITarget>();
+
+        public readonly Entity Entity;
+
+        private float soundRange;
+        private float sightRange;
+        
+        public float SoundRange
+        {
+            get { return soundRange; }
+            set { soundRange = Math.Max(value, 0.0f); }
+        }
+
+        public float SightRange
+        {
+            get { return sightRange; }
+            set { sightRange = Math.Max(value, 0.0f); }
+        }
+
+        public Vector2 WorldPosition
+        {
+            get { return Entity.WorldPosition; }
+        }
+
+        public Vector2 SimPosition
+        {
+            get { return Entity.SimPosition; }
+        }
+
+        public AITarget(Entity e)
+        {
+            Entity = e;
+            List.Add(this);
+        }
+
+        public void Remove()
+        {
+            List.Remove(this);
+        }
+
+        public void Draw(SpriteBatch spriteBatch)
+        {
+            if (!ShowAITargets) return;
+
+            var rangeSprite = GUI.SubmarineIcon;
+
+            if (soundRange > 0.0f)
+                rangeSprite.Draw(spriteBatch,
+                    new Vector2(WorldPosition.X, -WorldPosition.Y),
+                    Color.Cyan * 0.1f, rangeSprite.Origin,
+                    0.0f, soundRange / rangeSprite.size.X);
+
+            if (sightRange > 0.0f)
+                rangeSprite.Draw(spriteBatch,
+                    new Vector2(WorldPosition.X, -WorldPosition.Y),
+                    Color.Orange * 0.1f, rangeSprite.Origin,
+                    0.0f, sightRange / rangeSprite.size.X);
+        }
+
+    }
+}

Barotrauma/Source/Characters/AI/CrewCommander.cs

@@ -0,0 +1,313 @@
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+using System;
+using System.Linq;
+using System.Collections.Generic;
+
+namespace Barotrauma
+{
+    class CrewCommander
+    {
+        private CrewManager crewManager;
+
+        private GUIFrame frame;
+        //GUIListBox characterList;
+
+        private bool infoTextShown;
+
+        private int characterFrameBottom;
+
+        public GUIFrame Frame
+        {
+            get { return IsOpen ? frame : null; }
+        }
+
+        public bool IsOpen
+        {
+            get;
+            private set;
+        }
+
+        public CrewCommander(CrewManager crewManager)
+        {
+            this.crewManager = crewManager;
+        }
+
+        public void ToggleGUIFrame()
+        {
+            IsOpen = !IsOpen;
+
+            if (IsOpen) 
+            {
+                if (!infoTextShown)
+                {
+                    GUI.AddMessage("Press " + GameMain.Config.KeyBind(InputType.CrewOrders) + " to open/close the command menu", Color.Cyan, 5.0f);
+                    infoTextShown = true;
+                }
+
+                if (frame == null) CreateGUIFrame();
+                UpdateCharacters();
+            }
+        }
+
+        private void CreateGUIFrame()
+        {
+            frame = new GUIFrame(Rectangle.Empty, Color.Black * 0.6f, null);
+            frame.Padding = new Vector4(200.0f, 100.0f, 200.0f, 100.0f);
+
+            GUIButton closeButton = new GUIButton(new Rectangle(0, 50, 100, 20), "Close", Alignment.BottomCenter, "", frame);
+            closeButton.OnClicked = (GUIButton button, object userData) =>
+            {
+                ToggleGUIFrame();
+                return false;
+            };
+
+            //UpdateCharacters();
+
+            int buttonWidth = 130;
+            int spacing = 20;
+
+            int y = 50;
+
+            for (int n = 0; n<2; n++)
+            {                                      
+                List<Order> orders = (n==0) ? 
+                    Order.PrefabList.FindAll(o => o.ItemComponentType == null && string.IsNullOrEmpty(o.ItemName)) : 
+                    Order.PrefabList.FindAll(o => o.ItemComponentType != null || !string.IsNullOrEmpty(o.ItemName));
+
+                int startX = -(buttonWidth * orders.Count + spacing * (orders.Count - 1)) / 2;
+                
+                int i=0;
+                foreach (Order order in orders)
+                {
+                    int x = startX + (buttonWidth + spacing) * (i % orders.Count);
+
+                    if (order.ItemComponentType!=null || !string.IsNullOrEmpty(order.ItemName))
+                    {
+                        List<Item> matchingItems = !string.IsNullOrEmpty(order.ItemName) ?
+                            Item.ItemList.FindAll(it => it.Name == order.ItemName) :
+                            Item.ItemList.FindAll(it => it.components.Any(ic => ic.GetType() == order.ItemComponentType));
+
+                        int y2 = y;
+                        foreach (Item it in matchingItems)
+                        {
+                            var newOrder = new Order(order, it.components.Find(ic => ic.GetType() == order.ItemComponentType));
+
+                            CreateOrderButton(new Rectangle(x + buttonWidth / 2, y2, buttonWidth, 20), newOrder, y2==y);
+                            y2 += 25;
+                        }
+                    }
+                    else
+                    {
+                        CreateOrderButton(new Rectangle(x + buttonWidth / 2, y, buttonWidth, 20), order);
+                    }
+                    i++;
+                }
+
+                y += 100;
+            }
+        }
+
+        private GUIButton CreateOrderButton(Rectangle rect, Order order, bool createSymbol = true)
+        {
+            var orderButton = new GUIButton(rect, order.Name, null, Alignment.TopCenter, Alignment.Center, "GUITextBox", frame);
+            orderButton.Padding = new Vector4(5.0f, 5.0f, 5.0f, 5.0f);
+            /*orderButton.TextColor = Color.White;
+            orderButton.Color = Color.Black * 0.5f;
+            orderButton.HoverColor = Color.LightGray * 0.5f;
+            orderButton.OutlineColor = Color.LightGray * 0.8f;*/
+            orderButton.UserData = order;
+            orderButton.OnClicked = SetOrder;
+            
+            if (createSymbol)
+            {
+                var symbol = new GUIImage(new Rectangle(0,-60,64,64), order.SymbolSprite, Alignment.TopCenter, orderButton);
+                symbol.Color = order.Color;
+
+                orderButton.children.Insert(0, symbol);
+                orderButton.children.RemoveAt(orderButton.children.Count-1);
+            }
+            
+            return orderButton;
+        }
+
+        public void UpdateCharacters()
+        {
+            CreateGUIFrame();
+
+            List<GUIComponent> prevCharacterFrames = new List<GUIComponent>();
+            foreach (GUIComponent child in frame.children)
+            {
+                if (!(child.UserData is Character)) continue;
+
+                prevCharacterFrames.Add(child);
+            }
+            
+            foreach (GUIComponent child in prevCharacterFrames)
+            {
+                frame.RemoveChild(child);
+            }
+
+            List<Character> aliveCharacters = crewManager.characters.FindAll(c => !c.IsDead && c.AIController is HumanAIController);
+
+            characterFrameBottom = 0;
+
+            int charactersPerRow = 4;
+
+            int spacing = 5;
+
+            int i = 0;
+            foreach (Character character in aliveCharacters)
+            {
+                int rowCharacterCount = Math.Min(charactersPerRow, aliveCharacters.Count);
+                //if (i >= aliveCharacters.Count - charactersPerRow && aliveCharacters.Count % charactersPerRow > 0) rowCharacterCount = aliveCharacters.Count % charactersPerRow;
+
+               // rowCharacterCount = Math.Min(rowCharacterCount, aliveCharacters.Count - i);
+                int startX = -(150 * rowCharacterCount + spacing * (rowCharacterCount - 1)) / 2;
+
+
+                int x = startX + (150 + spacing) * (i % Math.Min(charactersPerRow, aliveCharacters.Count));
+                int y = (105 + spacing)*((int)Math.Floor((double)i / charactersPerRow));
+
+                GUIButton characterButton = new GUIButton(new Rectangle(x+75, y, 150, 40), "", null, Alignment.TopCenter, "GUITextBox", frame);
+                
+                characterButton.UserData = character;
+                characterButton.Padding = new Vector4(5.0f, 5.0f, 5.0f, 5.0f);
+                
+                characterButton.Color = Character.Controlled == character ? Color.Gold : Color.White;
+                /*characterButton.HoverColor = Color.LightGray * 0.5f;
+                characterButton.SelectedColor = Color.Gold * 0.6f;
+                characterButton.OutlineColor = Color.LightGray * 0.8f;*/
+
+                characterFrameBottom = Math.Max(characterFrameBottom, characterButton.Rect.Bottom);
+                
+                string name = character.Info.Name;
+                if (character.Info.Job != null) name += '\n' + "(" + character.Info.Job.Name + ")";
+
+                GUITextBlock textBlock = new GUITextBlock(
+                    new Rectangle(40, 0, 0, 25),
+                    name,
+                    Color.Transparent, null,
+                    Alignment.Left, Alignment.Left,
+                    "", characterButton, false);
+                textBlock.Font = GUI.SmallFont;
+                textBlock.Padding = new Vector4(5.0f, 0.0f, 5.0f, 0.0f);
+
+                new GUIImage(new Rectangle(-5, -5, 0, 0), character.AnimController.Limbs[0].sprite, Alignment.Left, characterButton);
+
+                var humanAi = character.AIController as HumanAIController;
+                if (humanAi != null && humanAi.CurrentOrder != null)
+                {
+                    CreateCharacterOrderFrame(characterButton, humanAi.CurrentOrder, humanAi.CurrentOrderOption);
+                }
+
+                i++;
+            }
+
+            foreach (GUIComponent child in frame.children)
+            {
+                if (!(child.UserData is Order)) continue;
+
+                Rectangle rect = child.Rect;
+                rect.Y += characterFrameBottom;
+
+                child.Rect = rect;
+            }
+        }
+
+        public void SelectCharacter(Character character)
+        {
+            var characterButton = frame.FindChild(character) as GUIButton;
+
+            if (characterButton == null) return;
+
+            characterButton.Selected = true;
+        }
+
+        private bool SetOrder(GUIButton button, object userData)
+        {
+            Order order = userData as Order;
+
+            foreach (GUIComponent child in frame.children)
+            {
+                var characterButton = child as GUIButton;
+                characterButton.State = GUIComponent.ComponentState.None;
+
+                if (!characterButton.Selected) continue;
+                characterButton.Selected = false;
+
+                CreateCharacterOrderFrame(characterButton, order, "");
+
+                var humanAi = (characterButton.UserData as Character).AIController as HumanAIController;
+
+                humanAi.SetOrder(order, "");
+            }
+
+            //characterList.Deselect();
+
+            return true;
+        }
+
+        private void CreateCharacterOrderFrame(GUIComponent characterFrame, Order order, string selectedOption)
+        {
+            var character = characterFrame.UserData as Character;
+            if (character == null) return;
+
+            var humanAi = character.AIController as HumanAIController;
+            if (humanAi == null) return;
+
+            var existingOrder = characterFrame.children.Find(c => c.UserData is Order);
+            if (existingOrder != null) characterFrame.RemoveChild(existingOrder);
+
+            var orderFrame = new GUIFrame(new Rectangle(-5, characterFrame.Rect.Height, characterFrame.Rect.Width, 30 + order.Options.Length * 15), "InnerFrame", characterFrame);
+            /*orderFrame.OutlineColor = Color.LightGray * 0.5f;*/
+            orderFrame.Padding = new Vector4(5.0f, 5.0f, 5.0f, 5.0f);
+            orderFrame.UserData = order;
+
+            var img = new GUIImage(new Rectangle(0, 0, 20, 20), order.SymbolSprite, Alignment.TopLeft, orderFrame);
+            img.Scale = 20.0f / img.SourceRect.Width;
+            img.Color = order.Color;
+            img.CanBeFocused = false;
+
+            new GUITextBlock(new Rectangle(img.Rect.Width, 0, 0, 20), order.DoingText, "", Alignment.TopLeft, Alignment.CenterLeft, orderFrame);
+            
+            var optionList = new GUIListBox(new Rectangle(0, 20, 0, 80), Color.Transparent, null, orderFrame);
+            optionList.UserData = order;
+
+            for (int i = 0; i < order.Options.Length; i++ )
+            {
+                var optionBox = new GUITextBlock(new Rectangle(0, 0, 0, 15), order.Options[i], "", Alignment.TopLeft, Alignment.CenterLeft, optionList);
+                optionBox.Font = GUI.SmallFont;
+                optionBox.UserData = order.Options[i];
+
+                if (selectedOption == order.Options[i])
+                {
+                    optionList.Select(i);
+                }
+            }
+            optionList.OnSelected = SelectOrderOption;
+
+        }
+
+        private bool SelectOrderOption(GUIComponent component, object userData)
+        {
+            string option = userData.ToString();
+            Order order = component.Parent.UserData as Order;
+            Character character = component.Parent.Parent.Parent.UserData as Character;
+
+            var humanAi = character.AIController as HumanAIController;
+            if (humanAi == null) return false;
+
+            humanAi.SetOrder(order, option);
+
+            return true;
+        }
+
+        public void Draw(SpriteBatch spriteBatch)
+        {
+            if (!IsOpen) return;
+
+            frame.Draw(spriteBatch);
+        }
+    }
+}

Barotrauma/Source/Characters/AI/EnemyAIController.cs

@@ -0,0 +1,576 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Xml.Linq;
+using FarseerPhysics;
+using Lidgren.Network;
+using Microsoft.Xna.Framework;
+using FarseerPhysics.Dynamics;
+using Microsoft.Xna.Framework.Graphics;
+
+namespace Barotrauma
+{
+    
+    class EnemyAIController : AIController
+    {
+        private const float UpdateTargetsInterval = 0.5f;
+
+        private const float RaycastInterval = 1.0f;
+
+        private bool attackWhenProvoked;
+        
+        //the preference to attack a specific type of target (-1.0 - 1.0)
+        //0.0 = doesn't attack targets of the type
+        //positive values = attacks targets of this type
+        //negative values = escapes targets of this type        
+        private float attackRooms, attackHumans, attackWeaker, attackStronger;
+
+        private SteeringManager outsideSteering, insideSteering;
+
+        private float updateTargetsTimer;
+
+        private float raycastTimer;
+        
+        //a timer for attacks such as biting that last for a specific amount of time
+        //the duration is determined by the attackDuration of the attacking limb
+        private float attackTimer;
+        
+        //a "cooldown time" after an attack during which the Character doesn't try to attack again
+        private float attackCoolDown;
+        private float coolDownTimer;
+        
+        //a point in a wall which the Character is currently targeting
+        private Vector2 wallAttackPos;
+        //the entity (a wall) which the Character is targeting
+        private IDamageable targetEntity;
+
+        //the limb selected for the current attack
+        private Limb attackingLimb;
+        
+        private AITarget selectedAiTarget;
+        private AITargetMemory selectedTargetMemory;
+        private float targetValue;
+        
+        private Dictionary<AITarget, AITargetMemory> targetMemories;
+
+        //the eyesight of the NPC (0.0 = blind, 1.0 = sees every target within sightRange)
+        private float sight;
+        //how far the NPC can hear targets from (0.0 = deaf, 1.0 = hears every target within soundRange)
+        private float hearing;
+
+        public AITarget SelectedAiTarget
+        {
+            get { return selectedAiTarget; }
+        }
+                        
+        public EnemyAIController(Character c, string file) : base(c)
+        {
+            targetMemories = new Dictionary<AITarget, AITargetMemory>();
+
+            XDocument doc = ToolBox.TryLoadXml(file);
+            if (doc == null || doc.Root == null) return;
+
+            XElement aiElement = doc.Root.Element("ai");
+            if (aiElement == null) return;
+
+            attackRooms     = ToolBox.GetAttributeFloat(aiElement, "attackrooms", 0.0f) / 100.0f;
+            attackHumans    = ToolBox.GetAttributeFloat(aiElement, "attackhumans", 0.0f) / 100.0f;
+            attackWeaker    = ToolBox.GetAttributeFloat(aiElement, "attackweaker", 0.0f) / 100.0f;
+            attackStronger  = ToolBox.GetAttributeFloat(aiElement, "attackstronger", 0.0f) / 100.0f;
+
+            attackCoolDown  = ToolBox.GetAttributeFloat(aiElement, "attackcooldown", 5.0f);
+
+            sight           = ToolBox.GetAttributeFloat(aiElement, "sight", 0.0f);
+            hearing         = ToolBox.GetAttributeFloat(aiElement, "hearing", 0.0f);
+
+            attackWhenProvoked = ToolBox.GetAttributeBool(aiElement, "attackwhenprovoked", false);
+
+            outsideSteering = new SteeringManager(this);
+            insideSteering = new IndoorsSteeringManager(this, false);
+
+            steeringManager = outsideSteering;
+
+            state = AiState.None;
+        }
+
+        public override void SelectTarget(AITarget target)
+        {
+            selectedAiTarget = target;
+            selectedTargetMemory = FindTargetMemory(target);
+
+            targetValue = 100.0f;
+        }
+        
+        public override void Update(float deltaTime)
+        {
+            bool ignorePlatforms = (-Character.AnimController.TargetMovement.Y > Math.Abs(Character.AnimController.TargetMovement.X));
+
+            if (steeringManager is IndoorsSteeringManager)
+            {
+                var currPath = ((IndoorsSteeringManager)steeringManager).CurrentPath;
+                if (currPath != null && currPath.CurrentNode != null)
+                {
+                    if (currPath.CurrentNode.SimPosition.Y < Character.AnimController.GetColliderBottom().Y)
+                    {
+                        ignorePlatforms = true;
+                    }
+                }
+            }
+            
+            Character.AnimController.IgnorePlatforms = ignorePlatforms;
+
+            if (Character.AnimController is HumanoidAnimController)
+            {
+                if (Math.Abs(Character.AnimController.movement.X) > 0.1f && !Character.AnimController.InWater)
+                {
+                    Character.AnimController.TargetDir = Character.AnimController.movement.X > 0.0f ? Direction.Right : Direction.Left;
+                }
+            }
+
+            if (updateTargetsTimer > 0.0)
+            {
+                updateTargetsTimer -= deltaTime;
+            }
+            else
+            {
+                UpdateTargets(Character);
+                updateTargetsTimer = UpdateTargetsInterval;
+
+                if (selectedAiTarget == null)
+                {
+                    state = AiState.None;
+                }
+                else
+                {
+                    state = (targetValue > 0.0f) ? AiState.Attack : AiState.Escape;
+                }
+                //if (coolDownTimer >= 0.0f) return;
+            }
+
+            steeringManager = Character.Submarine == null ? outsideSteering : insideSteering;
+
+            switch (state)
+            {
+                case AiState.None:
+                    UpdateNone(deltaTime);
+                    break;
+                case AiState.Attack:
+                    UpdateAttack(deltaTime);
+                    break;
+            }
+
+            steeringManager.Update();
+        }
+
+        private void UpdateNone(float deltaTime)
+        {
+            //wander around randomly
+            if (Character.Submarine==null && SimPosition.Y < ConvertUnits.ToSimUnits(SubmarineBody.DamageDepth*0.5f))
+            {
+                steeringManager.SteeringManual(deltaTime, Vector2.UnitY);
+            }
+            else
+            {
+                steeringManager.SteeringAvoid(deltaTime, 0.1f);
+                steeringManager.SteeringWander(0.5f);
+            }
+
+            attackingLimb = null;
+            attackTimer = 0.0f;
+
+            coolDownTimer -= deltaTime;  
+        }
+        
+        private void UpdateAttack(float deltaTime)
+        {
+            if (selectedAiTarget == null || selectedAiTarget.Entity == null || selectedAiTarget.Entity.Removed)
+            {
+                state = AiState.None;
+                return;
+            }
+
+            selectedTargetMemory.Priority -= deltaTime;
+
+            Vector2 attackSimPosition = Character.Submarine == null ? ConvertUnits.ToSimUnits(selectedAiTarget.WorldPosition) : selectedAiTarget.SimPosition;
+            if (wallAttackPos != Vector2.Zero && targetEntity != null)
+            {
+                attackSimPosition = wallAttackPos;
+
+                if (selectedAiTarget.Entity != null && Character.Submarine == null && selectedAiTarget.Entity.Submarine != null) attackSimPosition += ConvertUnits.ToSimUnits(selectedAiTarget.Entity.Submarine.Position);
+            }
+            
+            if (Math.Abs(Character.AnimController.movement.X) > 0.1f && !Character.AnimController.InWater)
+            {
+                Character.AnimController.TargetDir = Character.SimPosition.X < attackSimPosition.X ? Direction.Right : Direction.Left;
+            }
+
+            if (coolDownTimer > 0.0f)
+            {
+                UpdateCoolDown(attackSimPosition, deltaTime);
+                return;
+            }
+
+            if (raycastTimer > 0.0)
+            {
+                raycastTimer -= deltaTime;
+            }
+            else
+            {
+                GetTargetEntity();
+
+                raycastTimer = RaycastInterval;
+            }
+
+            //steeringManager.SteeringAvoid(deltaTime, 1.0f);
+
+            Limb attackLimb = attackingLimb;
+            //check if any of the limbs is close enough to attack the target
+            if (attackingLimb == null)
+            {
+                foreach (Limb limb in Character.AnimController.Limbs)
+                {
+                    if (limb.attack==null) continue;
+                    attackLimb = limb;
+
+                    if (ConvertUnits.ToDisplayUnits(Vector2.Distance(limb.SimPosition, attackSimPosition)) > limb.attack.Range) continue;
+                                        
+                    attackingLimb = limb;
+                    break;   
+                }
+
+                if (Character.IsRemotePlayer)
+                {
+                    if (!Character.IsKeyDown(InputType.Attack)) return;
+                }
+            }
+            if (attackLimb != null)
+            {
+                steeringManager.SteeringSeek(attackSimPosition - (attackLimb.SimPosition - SimPosition));
+
+                if (steeringManager is IndoorsSteeringManager)
+                {
+                    var indoorsSteering = (IndoorsSteeringManager)steeringManager;
+                    if (indoorsSteering.CurrentPath!=null && (indoorsSteering.CurrentPath.Finished || indoorsSteering.CurrentPath.Unreachable))
+                    {
+                        steeringManager.SteeringManual(deltaTime, attackSimPosition - attackLimb.SimPosition);
+                    }
+                }
+
+                if (attackingLimb != null) UpdateLimbAttack(deltaTime, attackingLimb, attackSimPosition);
+            }   
+        }
+
+        private void UpdateCoolDown(Vector2 attackPosition, float deltaTime)
+        {
+            coolDownTimer -= deltaTime;
+            attackingLimb = null;
+            
+            if (selectedAiTarget.Entity is Hull ||
+                Vector2.Distance(attackPosition, Character.AnimController.Limbs[0].SimPosition) < ConvertUnits.ToSimUnits(500.0f))
+            {
+                steeringManager.SteeringSeek(attackPosition, -0.8f);
+                steeringManager.SteeringAvoid(deltaTime, 1.0f);
+            }
+            else
+            {
+                steeringManager.SteeringSeek(attackPosition, -0.5f);
+                steeringManager.SteeringAvoid(deltaTime, 1.0f);
+            }
+        }
+
+        private void GetTargetEntity()
+        {
+            targetEntity = null;
+
+            if (Character.AnimController.CurrentHull != null)
+            {
+                wallAttackPos = Vector2.Zero;
+                return;
+            }
+            
+            //check if there's a wall between the target and the Character   
+            Vector2 rayStart = Character.SimPosition;
+            Vector2 rayEnd = selectedAiTarget.SimPosition;
+
+            if (selectedAiTarget.Entity.Submarine!=null && Character.Submarine==null)
+            {
+                rayStart -= ConvertUnits.ToSimUnits(selectedAiTarget.Entity.Submarine.Position);
+            }
+
+            Body closestBody = Submarine.CheckVisibility(rayStart, rayEnd);
+
+            if (Submarine.LastPickedFraction == 1.0f || closestBody == null)
+            {
+                wallAttackPos = Vector2.Zero;
+                return;
+            }
+            
+            Structure wall = closestBody.UserData as Structure;
+            if (wall == null)
+            {
+                wallAttackPos = Submarine.LastPickedPosition;
+                if (selectedAiTarget.Entity.Submarine!=null && Character.Submarine == null) wallAttackPos -= ConvertUnits.ToSimUnits(selectedAiTarget.Entity.Submarine.Position);
+            
+            }
+            else
+            {
+                int sectionIndex = wall.FindSectionIndex(ConvertUnits.ToDisplayUnits(Submarine.LastPickedPosition));
+
+                float sectionDamage = wall.SectionDamage(sectionIndex);
+                for (int i = sectionIndex - 2; i <= sectionIndex + 2; i++)
+                {
+                    if (wall.SectionBodyDisabled(i))
+                    {
+                        sectionIndex = i;
+                        break;
+                    }
+                    if (wall.SectionDamage(i) > sectionDamage) sectionIndex = i;
+                }
+                wallAttackPos = wall.SectionPosition(sectionIndex);
+                //if (wall.Submarine != null) wallAttackPos += wall.Submarine.Position;
+                wallAttackPos = ConvertUnits.ToSimUnits(wallAttackPos);
+            }
+            
+            targetEntity = closestBody.UserData as IDamageable;            
+        }
+
+        public override void OnAttacked(IDamageable attacker, float amount)
+        {
+            updateTargetsTimer = Math.Min(updateTargetsTimer, 0.1f);
+            coolDownTimer *= 0.1f;
+
+            if (amount > 0.1f && attackWhenProvoked)
+            {
+                attackHumans = 100.0f;
+                attackRooms = 100.0f;
+            }
+
+            if (attacker==null || attacker.AiTarget==null) return;
+            AITargetMemory targetMemory = FindTargetMemory(attacker.AiTarget);
+            targetMemory.Priority += amount;
+        }
+
+        private void UpdateLimbAttack(float deltaTime, Limb limb, Vector2 attackPosition)
+        {
+            var damageTarget = (wallAttackPos != Vector2.Zero && targetEntity != null) ? targetEntity : selectedAiTarget.Entity as IDamageable;
+
+            limb.UpdateAttack(deltaTime, attackPosition, damageTarget);
+
+            if (limb.AttackTimer >= limb.attack.Duration)
+            {
+                wallAttackPos = Vector2.Zero;
+                limb.AttackTimer = 0.0f;
+                coolDownTimer = attackCoolDown;                
+            }
+        }
+        
+        //goes through all the AItargets, evaluates how preferable it is to attack the target,
+        //whether the Character can see/hear the target and chooses the most preferable target within
+        //sight/hearing range
+        public void UpdateTargets(Character character)
+        {
+            var prevAiTarget = selectedAiTarget;
+
+            selectedAiTarget = null;
+            selectedTargetMemory = null;
+            targetValue = 0.0f;
+
+            UpdateTargetMemories();
+            
+            foreach (AITarget target in AITarget.List)
+            {
+                if (Level.Loaded != null && target.WorldPosition.Y > Level.Loaded.Size.Y)
+                {
+                    continue;
+                }
+
+                float valueModifier = 0.0f;
+                float dist = 0.0f;
+                
+                IDamageable targetDamageable = target.Entity as IDamageable;
+                if (targetDamageable!=null && targetDamageable.Health <= 0.0f) continue;
+
+                Character targetCharacter = target.Entity as Character;
+
+                //ignore the aitarget if it is the Character itself
+                if (targetCharacter == character) continue;
+                                
+                if (targetCharacter!=null)
+                {
+                    if (attackHumans == 0.0f || targetCharacter.SpeciesName != "human") continue;
+                    
+                    valueModifier = attackHumans;                  
+                }
+                else if (target.Entity!=null && attackRooms != 0.0f)
+                {
+                    //skip the target if it's the room the Character is inside of
+                    if (character.AnimController.CurrentHull != null && character.AnimController.CurrentHull == target.Entity as Hull) continue;
+
+                    valueModifier = attackRooms;
+                }
+
+                dist = Vector2.Distance(character.WorldPosition, target.WorldPosition);
+
+                //if the target has been within range earlier, the character will notice it more easily
+                //(i.e. remember where the target was)
+                if (targetMemories.ContainsKey(target)) dist *= 0.1f;
+
+                //ignore target if it's too far to see or hear
+                if (dist > target.SightRange * sight && dist > target.SoundRange * hearing) continue;
+
+                AITargetMemory targetMemory = FindTargetMemory(target);
+                valueModifier = valueModifier * targetMemory.Priority / dist;
+
+                if (Math.Abs(valueModifier) > Math.Abs(targetValue))
+                {                  
+                    Vector2 rayStart = character.AnimController.Limbs[0].SimPosition;
+                    Vector2 rayEnd = target.SimPosition;
+
+                    if (target.Entity.Submarine != null && character.Submarine==null)
+                    {
+                        rayStart -= ConvertUnits.ToSimUnits(target.Entity.Submarine.Position);
+                    }
+
+                    Body closestBody = Submarine.CheckVisibility(rayStart, rayEnd);
+                    Structure closestStructure = (closestBody == null) ? null : closestBody.UserData as Structure;
+
+                    if (targetDamageable != null)
+                    {
+                        valueModifier = valueModifier / targetDamageable.Health;                            
+                    }
+                    else if (closestStructure!=null)
+                    {
+                        valueModifier = valueModifier / ((IDamageable)closestStructure).Health;
+                    }
+                    else
+                    {
+                        valueModifier = valueModifier / 1000.0f;
+                    }
+
+                    if (selectedAiTarget == null || Math.Abs(valueModifier) > Math.Abs(targetValue))
+                    {
+                        selectedAiTarget = target;
+                        selectedTargetMemory = targetMemory;
+
+                        targetValue = valueModifier;
+                    }
+                }
+            }
+
+            if (selectedAiTarget != prevAiTarget)
+            {
+                wallAttackPos = Vector2.Zero;
+            }
+           
+        }
+
+        //find the targetMemory that corresponds to some AItarget or create if there isn't one yet
+        private AITargetMemory FindTargetMemory(AITarget target)
+        {
+            AITargetMemory memory = null;
+            if (targetMemories.TryGetValue(target, out memory))
+            {
+                return memory;
+            }
+
+            memory = new AITargetMemory(100.0f);
+            targetMemories.Add(target, memory);
+
+            return memory;
+        }
+
+        //go through all the targetmemories and delete ones that don't
+        //have a corresponding AItarget or whose priority is 0.0f
+        private void UpdateTargetMemories()
+        {
+
+            List<AITarget> toBeRemoved = new List<AITarget>();
+            foreach(KeyValuePair<AITarget, AITargetMemory> memory in targetMemories)
+            {
+                memory.Value.Priority += 0.5f;
+                if (Math.Abs(memory.Value.Priority) < 1.0f || !AITarget.List.Contains(memory.Key)) toBeRemoved.Add(memory.Key);
+            }
+
+            foreach (AITarget target in toBeRemoved)
+            {
+                targetMemories.Remove(target);
+            }
+        }
+
+        public override void DebugDraw(SpriteBatch spriteBatch)
+        {
+            if (Character.IsDead) return;
+
+            Vector2 pos = Character.WorldPosition;
+            pos.Y = -pos.Y;
+
+            if (selectedAiTarget!=null)
+            {
+                GUI.DrawLine(spriteBatch, pos, new Vector2(selectedAiTarget.WorldPosition.X, -selectedAiTarget.WorldPosition.Y), Color.Red);
+
+                if (wallAttackPos!=Vector2.Zero)
+                {
+                    GUI.DrawRectangle(spriteBatch, ConvertUnits.ToDisplayUnits(new Vector2(wallAttackPos.X, -wallAttackPos.Y)) - new Vector2(10.0f, 10.0f), new Vector2(20.0f, 20.0f), Color.Red, false);
+                }
+
+                GUI.Font.DrawString(spriteBatch, targetValue.ToString(), pos - Vector2.UnitY*20.0f, Color.Red);
+            }
+
+            if (selectedAiTarget != null)
+            {
+                GUI.DrawLine(spriteBatch,
+                    new Vector2(Character.DrawPosition.X, -Character.DrawPosition.Y),
+                    new Vector2(selectedAiTarget.WorldPosition.X, -selectedAiTarget.WorldPosition.Y), Color.Red);
+            }
+
+            GUI.Font.DrawString(spriteBatch, targetValue.ToString(), pos - Vector2.UnitY * 80.0f, Color.Red);
+
+            GUI.Font.DrawString(spriteBatch, "updatetargets: "+updateTargetsTimer, pos - Vector2.UnitY * 100.0f, Color.Red);
+            GUI.Font.DrawString(spriteBatch, "cooldown: " + coolDownTimer, pos - Vector2.UnitY * 120.0f, Color.Red);
+
+
+            IndoorsSteeringManager pathSteering = steeringManager as IndoorsSteeringManager;
+            if (pathSteering == null || pathSteering.CurrentPath == null || pathSteering.CurrentPath.CurrentNode == null) return;
+
+            GUI.DrawLine(spriteBatch,
+                new Vector2(Character.DrawPosition.X, -Character.DrawPosition.Y),
+                new Vector2(pathSteering.CurrentPath.CurrentNode.DrawPosition.X, -pathSteering.CurrentPath.CurrentNode.DrawPosition.Y),
+                Color.LightGreen);
+
+
+            for (int i = 1; i < pathSteering.CurrentPath.Nodes.Count; i++)
+            {
+                GUI.DrawLine(spriteBatch,
+                    new Vector2(pathSteering.CurrentPath.Nodes[i].DrawPosition.X, -pathSteering.CurrentPath.Nodes[i].DrawPosition.Y),
+                    new Vector2(pathSteering.CurrentPath.Nodes[i - 1].DrawPosition.X, -pathSteering.CurrentPath.Nodes[i - 1].DrawPosition.Y),
+                    Color.LightGreen);
+
+                GUI.SmallFont.DrawString(spriteBatch,
+                    pathSteering.CurrentPath.Nodes[i].ID.ToString(),
+                    new Vector2(pathSteering.CurrentPath.Nodes[i].DrawPosition.X, -pathSteering.CurrentPath.Nodes[i].DrawPosition.Y - 10),
+                    Color.LightGreen);
+            }
+        }
+    }
+
+    //the "memory" of the Character 
+    //keeps track of how preferable it is to attack a specific target
+    //(if the Character can't inflict much damage the target, the priority decreases
+    //and if the target attacks the Character, the priority increases)
+    class AITargetMemory
+    {
+        private float priority;
+        
+        public float Priority
+        {
+            get { return priority; }
+            set { priority = MathHelper.Clamp(value, 1.0f, 100.0f); }
+        }
+
+        public AITargetMemory(float priority)
+        {
+            this.priority = priority;
+        }
+
+    }
+}

Barotrauma/Source/Characters/AI/HumanAIController.cs

@@ -0,0 +1,196 @@
+using Microsoft.Xna.Framework;
+using System;
+
+namespace Barotrauma
+{
+    class HumanAIController : AIController
+    {
+        public static bool DisableCrewAI;
+
+        const float UpdateObjectiveInterval = 0.5f;
+
+        private AIObjectiveManager objectiveManager;
+        
+        private AITarget selectedAiTarget;
+
+        private float updateObjectiveTimer;
+
+        public Order CurrentOrder
+        {
+            get;
+            private set;
+        }
+
+        public string CurrentOrderOption
+        {
+            get;
+            private set;
+        }
+
+        public HumanAIController(Character c) : base(c)
+        {
+            steeringManager = new IndoorsSteeringManager(this, true);
+
+            objectiveManager = new AIObjectiveManager(c);
+            objectiveManager.AddObjective(new AIObjectiveFindSafety(c));
+            objectiveManager.AddObjective(new AIObjectiveIdle(c));
+
+            updateObjectiveTimer = Rand.Range(0.0f, UpdateObjectiveInterval);
+
+            if (GameMain.GameSession!=null && GameMain.GameSession.CrewManager!=null)
+            {
+                CurrentOrder = Order.PrefabList.Find(o => o.Name.ToLowerInvariant() == "dismissed");
+                objectiveManager.SetOrder(CurrentOrder, "");
+                GameMain.GameSession.CrewManager.SetCharacterOrder(Character, CurrentOrder);
+            }
+
+        }
+
+        public override void Update(float deltaTime)
+        {
+            if (DisableCrewAI || Character.IsUnconscious) return;
+
+            Character.ClearInputs();
+
+            //steeringManager = Character.AnimController.CurrentHull == null ? outdoorsSteeringManager : indoorsSteeringManager;
+
+            if (updateObjectiveTimer>0.0f)
+            {
+                updateObjectiveTimer -= deltaTime;
+            }
+            else
+            {
+                objectiveManager.UpdateObjectives();
+                updateObjectiveTimer = UpdateObjectiveInterval;
+            }
+
+            objectiveManager.DoCurrentObjective(deltaTime);
+         
+            float currObjectivePriority = objectiveManager.GetCurrentPriority(Character);
+            float moveSpeed = MathHelper.Clamp(currObjectivePriority/10.0f, 1.0f, 3.0f);
+            
+            steeringManager.Update(moveSpeed);
+
+            bool ignorePlatforms = Character.AnimController.TargetMovement.Y < -0.5f &&
+                (-Character.AnimController.TargetMovement.Y > Math.Abs(Character.AnimController.TargetMovement.X));
+
+            var currPath = (steeringManager as IndoorsSteeringManager).CurrentPath;
+            if (currPath != null && currPath.CurrentNode != null)
+            {
+                if (currPath.CurrentNode.SimPosition.Y < Character.AnimController.GetColliderBottom().Y)
+                {
+                    ignorePlatforms = true;
+                }
+            }
+
+            Character.AnimController.IgnorePlatforms = ignorePlatforms;
+            (Character.AnimController as HumanoidAnimController).Crouching = false;
+
+            if (!Character.AnimController.InWater)
+            {
+                Character.AnimController.TargetMovement = new Vector2(
+                    Character.AnimController.TargetMovement.X,
+                    MathHelper.Clamp(Character.AnimController.TargetMovement.Y, -1.0f, 1.0f)) * Character.SpeedMultiplier;
+
+                Character.SpeedMultiplier = 1.0f;
+            }
+
+            if (Character.SelectedConstruction != null && Character.SelectedConstruction.GetComponent<Items.Components.Ladder>()!=null)
+            {
+                if (currPath != null && currPath.CurrentNode != null && currPath.CurrentNode.Ladders != null)
+                {
+                    Character.AnimController.TargetMovement = new Vector2( 0.0f, Math.Sign(Character.AnimController.TargetMovement.Y));
+                }
+            }
+
+            //suit can be taken off if there character is inside a hull and there's air in the room
+            bool canTakeOffSuit = Character.AnimController.CurrentHull != null &&
+                Character.AnimController.CurrentHull.OxygenPercentage > 30.0f &&
+                Character.AnimController.CurrentHull.Volume < Character.AnimController.CurrentHull.FullVolume * 0.3f;
+
+            //the suit can be taken off and the character is running out of oxygen (couldn't find a tank for the suit?) or idling
+            //-> take the suit off
+            if (canTakeOffSuit && (Character.Oxygen < 50.0f || objectiveManager.CurrentObjective is AIObjectiveIdle))
+            {
+                var divingSuit = Character.Inventory.FindItem("Diving Suit");
+                if (divingSuit != null) divingSuit.Drop(Character);
+            }
+
+            if (Character.IsKeyDown(InputType.Aim))
+            {
+                var cursorDiffX = Character.CursorPosition.X - Character.Position.X;
+                if (cursorDiffX > 10.0f)
+                {
+                    Character.AnimController.TargetDir = Direction.Right;
+                }
+                else if (cursorDiffX < -10.0f)
+                {
+                    Character.AnimController.TargetDir = Direction.Left;
+                }
+
+                if (Character.SelectedConstruction != null) Character.SelectedConstruction.SecondaryUse(deltaTime, Character);
+
+            }
+            else if (Math.Abs(Character.AnimController.TargetMovement.X) > 0.1f && !Character.AnimController.InWater)
+            {
+                Character.AnimController.TargetDir = Character.AnimController.TargetMovement.X > 0.0f ? Direction.Right : Direction.Left;
+            }
+        }
+
+        public override void OnAttacked(IDamageable attacker, float amount)
+        {
+            if (amount <= 0.0f) return;
+
+            var enemy = attacker as Character;
+            if (enemy == null || enemy == Character) return;
+
+            objectiveManager.AddObjective(new AIObjectiveCombat(Character, enemy));
+        }
+
+        public void SetOrder(Order order, string option)
+        {
+            CurrentOrderOption = option;
+            CurrentOrder = order;
+            objectiveManager.SetOrder(order, option);
+
+            GameMain.GameSession.CrewManager.SetCharacterOrder(Character, order);
+        }
+
+        public override void SelectTarget(AITarget target)
+        {
+            selectedAiTarget = target;
+        }
+
+        public override void DebugDraw(Microsoft.Xna.Framework.Graphics.SpriteBatch spriteBatch)
+        {
+            if (selectedAiTarget != null)
+            {
+                GUI.DrawLine(spriteBatch,
+                    new Vector2(Character.DrawPosition.X, -Character.DrawPosition.Y), 
+                    new Vector2(selectedAiTarget.WorldPosition.X, -selectedAiTarget.WorldPosition.Y), Color.Red);
+            }
+
+            IndoorsSteeringManager pathSteering = steeringManager as IndoorsSteeringManager;
+            if (pathSteering == null || pathSteering.CurrentPath == null || pathSteering.CurrentPath.CurrentNode==null) return;
+
+            GUI.DrawLine(spriteBatch,
+                new Vector2(Character.DrawPosition.X, -Character.DrawPosition.Y),
+                new Vector2(pathSteering.CurrentPath.CurrentNode.DrawPosition.X, -pathSteering.CurrentPath.CurrentNode.DrawPosition.Y),
+                Color.LightGreen);
+
+
+            for (int i = 1; i < pathSteering.CurrentPath.Nodes.Count; i++)
+            {
+                GUI.DrawLine(spriteBatch,
+                    new Vector2(pathSteering.CurrentPath.Nodes[i].DrawPosition.X, -pathSteering.CurrentPath.Nodes[i].DrawPosition.Y),
+                    new Vector2(pathSteering.CurrentPath.Nodes[i - 1].DrawPosition.X, -pathSteering.CurrentPath.Nodes[i - 1].DrawPosition.Y),
+                    Color.LightGreen);
+
+                GUI.SmallFont.DrawString(spriteBatch, 
+                    pathSteering.CurrentPath.Nodes[i].ID.ToString(), 
+                    new Vector2(pathSteering.CurrentPath.Nodes[i].DrawPosition.X, -pathSteering.CurrentPath.Nodes[i].DrawPosition.Y - 10), 
+                    Color.LightGreen);
+            }
+        }
+    }
+}

Barotrauma/Source/Characters/AI/ISteerable.cs

@@ -0,0 +1,32 @@
+using Microsoft.Xna.Framework;
+
+namespace Barotrauma
+{
+    interface ISteerable
+    {
+
+        Vector2 Steering
+        {
+            get;
+            set;
+        }
+
+        Vector2 Velocity
+        {
+            get;
+        }
+        
+        Vector2 SimPosition 
+        {
+            get;
+        }
+
+        Vector2 WorldPosition
+        { 
+            get;
+        }
+        
+
+
+    }
+}

Barotrauma/Source/Characters/AI/IndoorsSteeringManager.cs

@@ -0,0 +1,313 @@
+using System;
+using System.Linq;
+using Microsoft.Xna.Framework;
+using Barotrauma.Items.Components;
+
+namespace Barotrauma
+{
+    class IndoorsSteeringManager : SteeringManager
+    {
+        private PathFinder pathFinder;
+        private SteeringPath currentPath;
+
+        private bool canOpenDoors;
+
+        private Character character;
+
+        private Vector2 currentTarget;
+
+        private float findPathTimer;
+
+        public SteeringPath CurrentPath
+        {
+            get { return currentPath; }
+        }
+
+        public PathFinder PathFinder
+        {
+            get { return pathFinder; }
+        }
+
+        public Vector2 CurrentTarget
+        {
+            get { return currentTarget; }
+        }
+
+        public IndoorsSteeringManager(ISteerable host, bool canOpenDoors)
+            : base(host)
+        {
+            pathFinder = new PathFinder(WayPoint.WayPointList.FindAll(wp => wp.SpawnType == SpawnType.Path), true);
+            pathFinder.GetNodePenalty = GetNodePenalty;
+
+            this.canOpenDoors = canOpenDoors;
+
+            character = (host as AIController).Character;
+
+            findPathTimer = Rand.Range(0.0f, 1.0f);
+        }
+
+        public override void Update(float speed = 1)
+        {
+            base.Update(speed);
+
+            findPathTimer -= 1.0f / 60.0f;
+        }
+
+        public void SetPath(SteeringPath path)
+        {
+            currentPath = path;
+            if (path.Nodes.Any()) currentTarget = path.Nodes[path.Nodes.Count - 1].SimPosition;
+            findPathTimer = 1.0f;
+        }
+
+
+        protected override Vector2 DoSteeringSeek(Vector2 target, float speed = 1)
+        {
+            //find a new path if one hasn't been found yet or the target is different from the current target
+            if (currentPath == null || Vector2.Distance(target, currentTarget)>1.0f || findPathTimer < -5.0f)
+            {
+                if (findPathTimer > 0.0f) return Vector2.Zero;
+
+                currentTarget = target;
+                Vector2 pos = host.SimPosition;
+                if (character != null && character.Submarine == null)
+                {
+                    var targetHull = Hull.FindHull(FarseerPhysics.ConvertUnits.ToDisplayUnits(target), null, false);
+                    if (targetHull!=null && targetHull.Submarine != null)
+                    {
+                        pos -= targetHull.SimPosition;
+                    }
+                }   
+
+                currentPath = pathFinder.FindPath(pos, target);
+
+                findPathTimer = Rand.Range(1.0f,1.2f);
+
+                return DiffToCurrentNode();
+            }
+                        
+            Vector2 diff = DiffToCurrentNode();
+            
+            var collider = character.AnimController.Collider;
+            //if not in water and the waypoint is between the top and bottom of the collider, no need to move vertically
+            if (!character.AnimController.InWater && 
+                character.AnimController.Anim != AnimController.Animation.Climbing &&
+                diff.Y < collider.height / 2 + collider.radius)
+            {
+                diff.Y = 0.0f;
+            }
+
+            if (diff.LengthSquared() < 0.001f) return -host.Steering;
+
+            return Vector2.Normalize(diff) * speed;          
+        }
+
+        private Vector2 DiffToCurrentNode()
+        {
+            if (currentPath == null || currentPath.Finished || currentPath.Unreachable) return Vector2.Zero;
+
+            if (currentPath.Finished)
+            {
+                Vector2 pos2 = host.SimPosition;
+                if (character != null && character.Submarine == null && CurrentPath.Nodes.Last().Submarine != null)
+                {
+                    //todo: take multiple subs into account
+                    pos2 -= CurrentPath.Nodes.Last().Submarine.SimPosition;
+                }   
+                return currentTarget-pos2;
+            }
+
+            if (canOpenDoors && !character.LockHands) CheckDoorsInPath();
+            
+            Vector2 pos = host.SimPosition;
+
+            if (character != null && currentPath.CurrentNode != null)
+            {
+                if (CurrentPath.CurrentNode.Submarine != null)
+                {
+                    if (character.Submarine == null)
+                    {
+                        pos -= CurrentPath.CurrentNode.Submarine.SimPosition;
+                    }
+                    else if (character.Submarine != currentPath.CurrentNode.Submarine)
+                    {
+                        pos -= FarseerPhysics.ConvertUnits.ToSimUnits(currentPath.CurrentNode.Submarine.Position-character.Submarine.Position);
+                    }
+                }
+
+            }
+
+            if (currentPath.CurrentNode!= null && currentPath.CurrentNode.Ladders!=null)
+            {
+                if (character.SelectedConstruction != currentPath.CurrentNode.Ladders.Item && currentPath.CurrentNode.Ladders.Item.IsInsideTrigger(character.WorldPosition))
+                {
+                    currentPath.CurrentNode.Ladders.Item.Pick(character, false, true);
+                }
+            }
+
+            var collider = character.AnimController.Collider;
+            Vector2 colliderBottom = character.AnimController.GetColliderBottom();
+
+            if (Math.Abs(collider.SimPosition.X - currentPath.CurrentNode.SimPosition.X) < collider.radius * 2 &&
+                currentPath.CurrentNode.SimPosition.Y > colliderBottom.Y &&
+                currentPath.CurrentNode.SimPosition.Y < colliderBottom.Y + 1.5f)
+            {
+                currentPath.SkipToNextNode();
+            }
+
+            if (currentPath.CurrentNode == null) return Vector2.Zero;
+            
+            if (character.AnimController.Anim == AnimController.Animation.Climbing)
+            {
+                Vector2 diff = currentPath.CurrentNode.SimPosition - pos;
+                
+                if (currentPath.CurrentNode.Ladders != null)
+                {
+                    //climbing ladders -> don't move horizontally
+                    diff.X = 0.0f;
+
+                    //at the same height as the waypoint
+                    if (Math.Abs(collider.SimPosition.Y - currentPath.CurrentNode.SimPosition.Y) < collider.height / 2 + collider.radius)
+                    {
+                        float heightFromFloor = character.AnimController.GetColliderBottom().Y - character.AnimController.FloorY;
+
+                        //we can safely skip to the next waypoint if the character is at a safe height above the floor,
+                        //or if the next waypoint in the path is also on ladders
+                        if ((heightFromFloor > 0.0f && heightFromFloor < collider.height) || 
+                            (currentPath.NextNode != null && currentPath.NextNode.Ladders != null))
+                        {
+                            currentPath.SkipToNextNode();
+                        }
+                    }
+                }
+
+                character.AnimController.IgnorePlatforms = false;
+                return diff;
+            }
+
+            return currentPath.CurrentNode.SimPosition - pos;
+        }
+
+        private void CheckDoorsInPath()
+        {
+            for (int i = 0; i < 2; i++)
+            {
+                WayPoint node = null;
+                WayPoint nextNode = null;
+                
+                if (i==0)
+                {
+                    node = currentPath.CurrentNode;
+                    nextNode = currentPath.NextNode;
+                }
+                else
+                {
+                    node = currentPath.PrevNode;
+                    nextNode = currentPath.CurrentNode;
+                }
+
+                if (node == null || node.ConnectedGap == null || node.ConnectedGap.ConnectedDoor == null) continue;
+
+                if (nextNode == null) continue;
+
+                var door = node.ConnectedGap.ConnectedDoor;
+
+                bool shouldBeOpen = false;
+
+                if (door.LinkedGap.isHorizontal)
+                {
+                    int currentDir = Math.Sign(nextNode.WorldPosition.X - door.Item.WorldPosition.X);
+
+                    shouldBeOpen = (door.Item.WorldPosition.X - character.WorldPosition.X) * currentDir > -50.0f;
+                }
+                else
+                {
+                    int currentDir = Math.Sign(nextNode.WorldPosition.Y - door.Item.WorldPosition.Y);
+
+                    shouldBeOpen = (door.Item.WorldPosition.Y - character.WorldPosition.Y) * currentDir > -80.0f;
+                }
+                
+
+                //toggle the door if it's the previous node and open, or if it's current node and closed
+                if (door.IsOpen != shouldBeOpen)
+                {
+                    var buttons = door.Item.GetConnectedComponents<Controller>(true);
+
+                    Controller closestButton = null;
+                    float closestDist = 0.0f;
+
+                    foreach (Controller controller in buttons)
+                    {
+                        float dist = Vector2.Distance(controller.Item.WorldPosition, character.WorldPosition);
+                        if (dist > controller.Item.PickDistance * 2.0f) continue;
+
+                        if (dist < closestDist || closestButton == null)
+                        {
+                            closestButton = controller;
+                            closestDist = dist;
+                        }
+                    }
+
+                    if (closestButton != null)
+                    {
+                        if (!closestButton.HasRequiredItems(character, false) && shouldBeOpen)
+                        {
+                            currentPath.Unreachable = true;
+                            return;
+                        }
+
+                        closestButton.Item.Pick(character, false, true);
+                        break;
+                    }
+                }
+            }
+        }
+
+        private float? GetNodePenalty(PathNode node, PathNode nextNode)
+        {
+            if (character == null) return 0.0f;
+            
+            float penalty = 0.0f;
+            if (nextNode.Waypoint.ConnectedGap != null && nextNode.Waypoint.ConnectedGap.Open < 0.9f)
+            {
+                if (nextNode.Waypoint.ConnectedGap.ConnectedDoor == null)
+                {
+                    penalty = 100.0f;
+                }
+
+                //door closed and the character can't open doors -> node can't be traversed
+                if (!canOpenDoors || character.LockHands) return null;
+
+                var doorButtons = nextNode.Waypoint.ConnectedGap.ConnectedDoor.Item.GetConnectedComponents<Controller>();
+                if (!doorButtons.Any()) return null;
+
+                foreach (Controller button in doorButtons)
+                {
+                    if (Math.Sign(button.Item.Position.X - nextNode.Waypoint.Position.X) !=
+                        Math.Sign(node.Position.X - nextNode.Position.X)) continue;
+
+                    if (!button.HasRequiredItems(character, false)) return null;
+                }
+            }
+
+            if (node.Waypoint!=null && node.Waypoint.CurrentHull!=null)
+            {
+                var hull = node.Waypoint.CurrentHull;
+
+                if (hull.FireSources.Count > 0)
+                {
+                    foreach (FireSource fs in hull.FireSources)
+                    {
+                        penalty += fs.Size.X * 10.0f;
+                    }
+                }
+
+                if (character.NeedsAir && hull.Volume / hull.Rect.Width > 100.0f) penalty += 500.0f;
+                if (character.PressureProtection < 10.0f && hull.Volume > hull.FullVolume) penalty += 1000.0f;
+            }
+
+            return penalty;
+        }
+    }
+    
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjective.cs

@@ -0,0 +1,88 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Barotrauma
+{
+    class AIObjective
+    {
+        protected List<AIObjective> subObjectives;
+
+        protected float priority;
+
+        protected Character character;
+
+        protected string option;
+
+        public virtual bool IsCompleted()
+        {
+            return false;
+        }
+
+        public virtual bool CanBeCompleted
+        {
+            get { return true; }
+        }
+
+        public string Option
+        {
+            get { return option; }
+        }
+            
+
+        public AIObjective(Character character, string option)
+        {
+            subObjectives = new List<AIObjective>();
+
+            this.character = character;
+
+            this.option = option;
+
+#if DEBUG
+            IsDuplicate(null);
+#endif
+        }
+
+        /// <summary>
+        /// makes the character act according to the objective, or according to any subobjectives that
+        /// need to be completed before this one
+        /// </summary>
+        public void TryComplete(float deltaTime)
+        {
+            subObjectives.RemoveAll(s => s.IsCompleted() || !s.CanBeCompleted);
+
+            foreach (AIObjective objective in subObjectives)
+            {
+                objective.TryComplete(deltaTime);
+                return;
+            }
+
+            Act(deltaTime);
+        }
+
+        protected virtual void Act(float deltaTime) { }
+
+        public void AddSubObjective(AIObjective objective)
+        {
+            if (subObjectives.Any(o => o.IsDuplicate(objective))) return;
+
+            subObjectives.Add(objective);
+        }
+
+        public virtual float GetPriority(Character character)
+        {
+            return 0.0f;
+        }
+
+        public virtual bool IsDuplicate(AIObjective otherObjective)
+        {
+#if DEBUG
+            throw new NotImplementedException();
+#else
+            return (this.GetType() == otherObjective.GetType());
+#endif
+
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveCombat.cs

@@ -0,0 +1,130 @@
+using Microsoft.Xna.Framework;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Barotrauma
+{
+    class AIObjectiveCombat : AIObjective
+    {
+        const float CoolDown = 10.0f;
+
+        private Character enemy;
+
+        private AIObjectiveFindSafety escapeObjective;
+
+        float coolDownTimer;
+
+        private readonly float enemyStrength;
+
+        public AIObjectiveCombat (Character character, Character enemy)
+            : base(character, "")
+        {
+            this.enemy = enemy;
+
+            foreach (Limb limb in enemy.AnimController.Limbs)
+            {
+                if (limb.attack == null) continue;
+                enemyStrength += limb.attack.GetDamage(1.0f);
+            }
+
+            coolDownTimer = CoolDown;
+
+        }
+
+        protected override void Act(float deltaTime)
+        {
+            coolDownTimer -= deltaTime;
+
+            var weapon = character.Inventory.FindItem("weapon");
+            
+            if (weapon==null)
+            {
+                Escape(deltaTime);
+            }
+            else
+            {
+                if (!character.SelectedItems.Contains(weapon))
+                {
+                    character.Inventory.TryPutItem(weapon, 3, false);
+                    weapon.Equip(character);
+                }
+                character.CursorPosition = enemy.Position;
+                character.SetInput(InputType.Aim, false, true);
+
+                Vector2 enemyDiff = Vector2.Normalize(enemy.Position - character.Position);
+                float weaponAngle = ((weapon.body.Dir == 1.0f) ? weapon.body.Rotation : weapon.body.Rotation - MathHelper.Pi);
+                Vector2 weaponDir = new Vector2((float)Math.Cos(weaponAngle), (float)Math.Sin(weaponAngle));
+
+                if (Vector2.Dot(enemyDiff, weaponDir) < 0.9f) return;
+
+                List<FarseerPhysics.Dynamics.Body> ignoredBodies = new List<FarseerPhysics.Dynamics.Body>();
+                foreach (Limb limb in character.AnimController.Limbs)
+                {
+                    ignoredBodies.Add(limb.body.FarseerBody);
+                }
+
+                var pickedBody = Submarine.PickBody(character.SimPosition, enemy.SimPosition, ignoredBodies);
+                if (pickedBody != null && !(pickedBody.UserData is Limb)) return;
+
+               weapon.Use(deltaTime, character);
+            }
+        }
+
+        private void Escape(float deltaTime)
+        {
+            if (escapeObjective == null)
+            {
+                escapeObjective = new AIObjectiveFindSafety(character);
+            }
+            
+            if (enemy.AnimController.CurrentHull == character.AnimController.CurrentHull)
+            {
+                escapeObjective.OverrideCurrentHullSafety = 0.0f;
+            }
+            else
+            {
+                escapeObjective.OverrideCurrentHullSafety = null;
+            }
+
+            escapeObjective.TryComplete(deltaTime);
+
+            //if (Vector2.Distance(character.SimPosition, enemy.SimPosition) < 3.0f)
+            //{
+            //    character.AIController.SteeringManager.SteeringManual(deltaTime, 
+            //        new Vector2(Math.Sign(character.SimPosition.X - enemy.SimPosition.X), 0.0f));            
+            //    coolDownTimer = CoolDown;
+            //}
+        }
+
+        public override bool IsCompleted()
+        {
+            return enemy.IsDead || coolDownTimer <= 0.0f;
+        }
+
+        public override float GetPriority(Character character)
+        {
+            //clamp the strength to the health of this character
+            //(it doesn't make a difference whether the enemy does 200 or 600 damage, it's one hit kill anyway)
+
+            float enemyDanger = Math.Min(enemyStrength, character.Health) + enemy.Health / 10.0f;
+
+            EnemyAIController enemyAI = enemy.AIController as EnemyAIController;
+            if (enemyAI != null)
+            {
+                if (enemyAI.SelectedAiTarget == character.AiTarget) enemyDanger *= 2.0f;
+            }
+
+            return Math.Max(enemyDanger, AIObjectiveManager.OrderPriority);
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            AIObjectiveCombat objective = otherObjective as AIObjectiveCombat;
+            if (objective == null) return false;
+
+            return objective.enemy == enemy;
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveContainItem.cs

@@ -0,0 +1,90 @@
+using Barotrauma.Items.Components;
+using Microsoft.Xna.Framework;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Barotrauma
+{
+    class AIObjectiveContainItem: AIObjective
+    {
+        private string itemName;
+
+        private ItemContainer container;
+        
+        bool isCompleted;
+
+        public bool IgnoreAlreadyContainedItems;
+        
+        public AIObjectiveContainItem(Character character, string itemName, ItemContainer container)
+            : base (character, "")
+        {
+            this.itemName = itemName;
+            this.container = container;
+
+            //check if the container has room for more items
+            //canBeCompleted = false;
+            //foreach (Item contained in container.inventory.Items)
+            //{
+            //    if (contained != null) continue;
+            //    canBeCompleted = true;
+            //    break;
+            //}
+        }
+
+        public override bool IsCompleted()
+        {
+            return isCompleted || container.Inventory.FindItem(itemName)!=null;
+        }
+
+        protected override void Act(float deltaTime)
+        {
+            if (isCompleted) return;
+
+            //get the item that should be contained
+            var itemToContain = character.Inventory.FindItem(itemName);
+            if (itemToContain == null)
+            {
+                var getItem = new AIObjectiveGetItem(character, itemName);
+                getItem.IgnoreContainedItems = IgnoreAlreadyContainedItems;
+                AddSubObjective(getItem);
+                return;
+            }
+
+            if (container.Item.ParentInventory == character.Inventory)
+            {
+                var containedItems = container.Inventory.Items;
+                //if there's already something in the mask (empty oxygen tank?), drop it
+                var existingItem = containedItems.FirstOrDefault(i => i != null);
+                if (existingItem != null) existingItem.Drop(character);
+                
+                character.Inventory.RemoveItem(itemToContain);
+                container.Inventory.TryPutItem(itemToContain, null);
+            }
+            else
+            {
+                if (Vector2.Distance(character.Position, container.Item.Position) > container.Item.PickDistance
+                    && !container.Item.IsInsideTrigger(character.Position))
+                {
+                    AddSubObjective(new AIObjectiveGoTo(container.Item, character));
+                    return;
+                }
+
+                container.Combine(itemToContain);
+            }
+
+            isCompleted = true;
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            AIObjectiveContainItem objective = otherObjective as AIObjectiveContainItem;
+            if (objective == null) return false;
+
+            return objective.itemName == itemName && objective.container == container;
+        }
+
+    
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveFindDivingGear.cs

@@ -0,0 +1,89 @@
+using Barotrauma.Items.Components;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Barotrauma
+{
+    class AIObjectiveFindDivingGear : AIObjective
+    {
+        private AIObjective subObjective;
+
+        private string gearName;
+
+        public override bool IsCompleted()
+        {
+            var item = character.Inventory.FindItem(gearName);
+            if (item == null) return false;
+
+            var containedItems = item.ContainedItems;
+            var oxygenTank = Array.Find(containedItems, i => i.Name == "Oxygen Tank" && i.Condition > 0.0f);
+            return oxygenTank != null;
+        }
+
+        public AIObjectiveFindDivingGear(Character character, bool needDivingSuit)
+            : base(character, "")
+        {
+            gearName = needDivingSuit ? "Diving Suit" : "diving";
+        }
+
+        protected override void Act(float deltaTime)
+        {
+            var item = character.Inventory.FindItem(gearName);
+            if (item == null)
+            {
+                //get a diving mask/suit first
+                if (!(subObjective is AIObjectiveGetItem))
+                {
+                    subObjective = new AIObjectiveGetItem(character, gearName, true);
+                }
+            }
+            else
+            {
+                var containedItems = item.ContainedItems;
+                if (containedItems == null) return;
+
+                //check if there's an oxygen tank in the mask
+                var oxygenTank = Array.Find(containedItems, i => i.Name == "Oxygen Tank");
+
+                if (oxygenTank != null)
+                {
+                    if (oxygenTank.Condition > 0.0f)
+                    {
+                        return;
+                    }
+                    else
+                    {
+                        oxygenTank.Drop();
+                    }
+                }
+
+
+                if (!(subObjective is AIObjectiveContainItem) || subObjective.IsCompleted())
+                {
+                    subObjective = new AIObjectiveContainItem(character, "Oxygen Tank", item.GetComponent<ItemContainer>());
+                }
+            }
+
+            if (subObjective != null)
+            {
+                subObjective.TryComplete(deltaTime);
+
+                //isCompleted = subObjective.IsCompleted();
+            }
+        }
+
+        public override float GetPriority(Character character)
+        {
+            if (character.AnimController.CurrentHull == null) return 100.0f;
+
+            return 100.0f - character.Oxygen;
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            return otherObjective is AIObjectiveFindDivingGear;
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveFindSafety.cs

@@ -0,0 +1,216 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Barotrauma
+{
+    class AIObjectiveFindSafety : AIObjective
+    {
+        const float SearchHullInterval = 3.0f;
+        const float MinSafety = 50.0f;
+
+        private AIObjectiveGoTo goToObjective;
+
+        private List<Hull> unreachable;
+
+        private float currenthullSafety;
+
+        private float searchHullTimer;
+
+        private AIObjective divingGearObjective;
+
+        public float? OverrideCurrentHullSafety;
+
+        public AIObjectiveFindSafety(Character character)
+            : base(character, "")
+        {
+            unreachable = new List<Hull>();
+        }
+
+        protected override void Act(float deltaTime)
+        {
+
+            var currentHull = character.AnimController.CurrentHull;
+
+            currenthullSafety = OverrideCurrentHullSafety == null ?
+                GetHullSafety(currentHull, character) : (float)OverrideCurrentHullSafety;
+
+            if (currentHull != null)
+            {
+                if (NeedsDivingGear())
+                {
+                    if (!FindDivingGear(deltaTime)) return;
+                }
+
+                if (currenthullSafety > MinSafety)
+                {
+                    if (Math.Abs(currentHull.WorldPosition.X - character.WorldPosition.X) > 100.0f)
+                    {
+                        character.AIController.SteeringManager.SteeringSeek(currentHull.SimPosition, 0.5f);
+                    }
+                    else
+                    {
+
+                        character.AIController.SteeringManager.Reset();
+                    }
+
+                    character.AIController.SelectTarget(null);
+
+                    goToObjective = null;
+                    return;
+                }
+            }
+
+            if (searchHullTimer > 0.0f)
+            {
+                searchHullTimer -= deltaTime;
+            }
+            else
+            {
+                var bestHull = FindBestHull();
+                if (bestHull != null)
+                {
+                    goToObjective = new AIObjectiveGoTo(bestHull, character);
+                }
+
+                searchHullTimer = SearchHullInterval;
+            }
+
+            if (goToObjective != null)
+            {
+                var pathSteering = character.AIController.SteeringManager as IndoorsSteeringManager;
+                if (pathSteering!=null && pathSteering.CurrentPath!= null && 
+                    pathSteering.CurrentPath.Unreachable && !unreachable.Contains(goToObjective.Target))
+                {
+                    unreachable.Add(goToObjective.Target as Hull);
+                }
+
+
+                goToObjective.TryComplete(deltaTime);
+            }
+        }
+
+        private bool FindDivingGear(float deltaTime)
+        {
+            if (divingGearObjective==null)
+            {
+                divingGearObjective = new AIObjectiveFindDivingGear(character, false);
+            }
+
+            if (divingGearObjective.IsCompleted()) return true;
+
+            divingGearObjective.TryComplete(deltaTime);
+            return divingGearObjective.IsCompleted();
+        }
+
+        private Hull FindBestHull()
+        {
+            Hull bestHull = null;
+            float bestValue = currenthullSafety;
+
+            foreach (Hull hull in Hull.hullList)
+            {
+                if (hull == character.AnimController.CurrentHull || unreachable.Contains(hull)) continue;
+
+                float hullValue = GetHullSafety(hull, character);
+                hullValue -= (float)Math.Sqrt(Math.Abs(character.Position.X - hull.Position.X));
+                hullValue -= (float)Math.Sqrt(Math.Abs(character.Position.Y - hull.Position.Y) * 2.0f);
+
+                if (bestHull == null || hullValue > bestValue)
+                {
+                    bestHull = hull;
+                    bestValue = hullValue;
+                }
+            }
+
+            return bestHull;
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            return (otherObjective is AIObjectiveFindSafety);
+        }
+
+        private bool NeedsDivingGear()
+        {
+            var currentHull = character.AnimController.CurrentHull;
+            if (currentHull == null) return true;
+
+            //there's lots of water in the room -> get a suit
+            if (currentHull.Volume / currentHull.FullVolume > 0.5f) return true;
+
+            if (currentHull.OxygenPercentage < 30.0f) return true;
+
+            return false;
+        }
+
+        public override float GetPriority(Character character)
+        {
+            if (character.Oxygen < 80.0f)
+            {
+                return 150.0f - character.Oxygen;
+            }
+
+            if (character.AnimController.CurrentHull == null) return 5.0f;
+            currenthullSafety = GetHullSafety(character.AnimController.CurrentHull, character);
+            priority = 100.0f - currenthullSafety;
+
+            var nearbyHulls = character.AnimController.CurrentHull.GetConnectedHulls(3);
+
+            foreach (Hull hull in nearbyHulls)
+            {
+                foreach (FireSource fireSource in hull.FireSources)
+                {
+                    //increase priority if almost within damage range of a fire
+                    if (character.Position.X > fireSource.Position.X - fireSource.DamageRange * 2 &&
+                        character.Position.X < fireSource.Position.X + fireSource.Size.X + fireSource.DamageRange * 2 &&
+                        character.Position.Y > hull.Rect.Y - hull.Rect.Height &&
+                        character.Position.Y < hull.Rect.Y)
+                    {
+                        priority += Math.Max(fireSource.Size.X, 50.0f);
+                    }
+                }
+            }
+
+
+            if (NeedsDivingGear())
+            {
+                if (divingGearObjective != null && !divingGearObjective.IsCompleted()) priority += 20.0f;
+            }
+           
+            return priority;
+        }
+
+        private static float GetHullSafety(Hull hull, Character character)
+        {
+            if (hull == null) return 0.0f;
+
+            float waterPercentage = (hull.Volume / hull.FullVolume) * 100.0f;
+            float fireAmount = 0.0f;
+
+            var nearbyHulls = hull.GetConnectedHulls(3);
+
+            foreach (Hull hull2 in nearbyHulls)
+            {
+                foreach (FireSource fireSource in hull2.FireSources)
+                {
+                    //increase priority if almost within damage range of a fire
+                    if (character.Position.X > fireSource.Position.X - fireSource.DamageRange * 2 &&
+                        character.Position.X < fireSource.Position.X + fireSource.Size.X + fireSource.DamageRange * 2 &&
+                        character.Position.Y > hull2.Rect.Y - hull2.Rect.Height &&
+                        character.Position.Y < hull2.Rect.Y)
+                    {
+                        fireAmount += Math.Max(fireSource.Size.X, 50.0f);
+                    }
+                }
+            }
+
+            float safety = 100.0f - fireAmount;
+
+            if (waterPercentage > 30.0f && character.OxygenAvailable <= 0.0f) safety -= waterPercentage;
+            if (hull.OxygenPercentage < 30.0f) safety -= (30.0f - hull.OxygenPercentage) * 5.0f;
+
+            return safety;
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveFixLeak.cs

@@ -0,0 +1,98 @@
+using Barotrauma.Items.Components;
+using FarseerPhysics;
+using Microsoft.Xna.Framework;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Barotrauma
+{
+    class AIObjectiveFixLeak : AIObjective
+    {
+        private Gap leak;
+
+        public Gap Leak
+        {
+            get { return leak; }
+        }
+
+        public AIObjectiveFixLeak(Gap leak, Character character)
+            : base (character, "")
+        {
+            this.leak = leak;
+        }
+
+        public override float GetPriority(Character character)
+        {
+            if (leak.Open == 0.0f) return 0.0f;
+
+            float leakSize = (leak.isHorizontal ? leak.Rect.Height : leak.Rect.Width) * Math.Max(leak.Open, 0.1f);
+
+            float dist = Vector2.DistanceSquared(character.SimPosition, leak.SimPosition);
+            dist = Math.Max(dist/100.0f, 1.0f);
+            return Math.Min(leakSize/dist, 40.0f);
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            AIObjectiveFixLeak fixLeak = otherObjective as AIObjectiveFixLeak;
+            if (fixLeak == null) return false;
+            return fixLeak.leak == leak;
+        }
+
+        protected override void Act(float deltaTime)
+        {
+            var weldingTool = character.Inventory.FindItem("Welding Tool");
+
+            if (weldingTool == null)
+            {
+                subObjectives.Add(new AIObjectiveGetItem(character, "Welding Tool", true));
+                return;
+            }
+            else
+            {
+                var containedItems = weldingTool.ContainedItems;
+                if (containedItems == null) return;
+                
+                var fuelTank = Array.Find(containedItems, i => i.Name == "Welding Fuel Tank" && i.Condition > 0.0f);
+
+                if (fuelTank == null)
+                {
+                    AddSubObjective(new AIObjectiveContainItem(character, "Welding Fuel Tank", weldingTool.GetComponent<ItemContainer>()));
+                }
+            }
+
+            var repairTool = weldingTool.GetComponent<RepairTool>();
+            if (repairTool == null) return;
+
+            if (Vector2.Distance(character.WorldPosition, leak.WorldPosition) > 300.0f)
+            {
+                AddSubObjective(new AIObjectiveGoTo(ConvertUnits.ToSimUnits(GetStandPosition()), character));
+            }
+            else
+            {
+                AddSubObjective(new AIObjectiveOperateItem(repairTool, character, "", leak));
+            }            
+        }
+
+        private Vector2 GetStandPosition()
+        {
+            Vector2 standPos = leak.Position;
+            var hull = leak.FlowTargetHull;
+
+            if (hull == null) return standPos;
+            
+            if (leak.isHorizontal)
+            {
+                standPos += Vector2.UnitX * Math.Sign(hull.Position.X - leak.Position.X) * leak.Rect.Width;
+            }
+            else
+            {
+                standPos += Vector2.UnitY * Math.Sign(hull.Position.Y - leak.Position.Y) * leak.Rect.Height;
+            }
+
+            return standPos;            
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveFixLeaks.cs

@@ -0,0 +1,101 @@
+using System;
+using Microsoft.Xna.Framework;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Barotrauma
+{
+    class AIObjectiveFixLeaks : AIObjective
+    {
+        const float UpdateGapListInterval = 10.0f;
+
+        private float updateGapListTimer;
+
+        private AIObjectiveIdle idleObjective;
+
+        private List<AIObjectiveFixLeak> objectiveList;
+
+        public AIObjectiveFixLeaks(Character character)
+            : base (character, "")
+        {
+            objectiveList = new List<AIObjectiveFixLeak>();
+        }
+
+        public override bool IsCompleted()
+        {
+            return false;
+        }
+
+        protected override void Act(float deltaTime)
+        {
+            updateGapListTimer -= deltaTime;
+
+            if (updateGapListTimer<=0.0f)
+            {
+                UpdateGapList();
+
+                updateGapListTimer = UpdateGapListInterval;
+            }
+
+            if (objectiveList.Any())
+            {
+                objectiveList[objectiveList.Count - 1].TryComplete(deltaTime);
+
+                if (!objectiveList[objectiveList.Count - 1].CanBeCompleted ||
+                    objectiveList[objectiveList.Count - 1].IsCompleted())
+                {
+                    objectiveList.RemoveAt(objectiveList.Count - 1);
+                }
+            }
+            else
+            {
+                if (idleObjective == null) idleObjective = new AIObjectiveIdle(character);
+                idleObjective.TryComplete(deltaTime);
+            }
+        }
+
+        private void UpdateGapList()
+        {
+            objectiveList.Clear();
+            
+            foreach (Gap gap in Gap.GapList)
+            {
+                if (gap.ConnectedWall == null) continue;
+                if (gap.ConnectedDoor != null || gap.Open <= 0.0f) continue;
+
+                float gapPriority = GetGapFixPriority(gap);
+
+                int index = 0;
+                while (index < objectiveList.Count &&
+                    GetGapFixPriority(objectiveList[index].Leak) < gapPriority)
+                {
+                    index++;
+                }
+
+                objectiveList.Insert(index, new AIObjectiveFixLeak(gap, character));
+            }
+        }
+
+        private float GetGapFixPriority(Gap gap)
+        {
+            if (gap == null) return 0.0f;
+
+            //larger gap -> higher priority
+            float gapPriority = (gap.isHorizontal ? gap.Rect.Width : gap.Rect.Height) * gap.Open;
+
+            //prioritize gaps that are close
+            gapPriority /= Math.Max(Vector2.Distance(character.WorldPosition, gap.WorldPosition), 1.0f);
+
+            //gaps to outside are much higher priority
+            if (!gap.IsRoomToRoom) gapPriority *= 10.0f;
+
+            return gapPriority;
+
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            return otherObjective is AIObjectiveFixLeaks;
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveGetItem.cs

@@ -0,0 +1,183 @@
+using Barotrauma.Items.Components;
+using Microsoft.Xna.Framework;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Barotrauma
+{
+    class AIObjectiveGetItem : AIObjective
+    {
+        private string itemName;
+
+        private Item targetItem, moveToTarget;
+
+        private int currSearchIndex;
+
+        private bool canBeCompleted;
+
+        public bool IgnoreContainedItems;
+
+        private AIObjectiveGoTo goToObjective;
+
+        private bool equip;
+
+        public override bool CanBeCompleted
+        {
+            get { return canBeCompleted; }
+        }
+
+        public AIObjectiveGetItem(Character character, Item targetItem, bool equip = false)
+            : base(character, "")
+        {
+            canBeCompleted = true;
+
+            this.equip = equip;
+
+            currSearchIndex = 0;
+
+            this.targetItem = targetItem;
+        }
+
+        public AIObjectiveGetItem(Character character, string itemName, bool equip=false)
+            : base (character, "")
+        {
+            canBeCompleted = true;
+
+            this.equip = equip;
+
+            currSearchIndex = 0;
+            
+            this.itemName = itemName;
+        }
+
+        protected override void Act(float deltaTime)
+        {
+            FindTargetItem();
+            if (targetItem == null || moveToTarget == null) return;
+
+            if (Vector2.Distance(character.Position, moveToTarget.Position) < targetItem.PickDistance*2.0f)
+            {
+                int targetSlot = -1;
+                if (equip)
+                {
+                    var pickable = targetItem.GetComponent<Pickable>();
+                    if (pickable == null)
+                    {
+                        canBeCompleted = false;
+                        return;
+                    }
+
+                    //check if all the slots required by the item are free
+                    foreach (InvSlotType slots in pickable.AllowedSlots)
+                    {
+                        if (slots.HasFlag(InvSlotType.Any)) continue;
+                            
+                        for (int i = 0; i<character.Inventory.Items.Length; i++)
+                        {
+                            //slot not needed by the item, continue
+                            if (!slots.HasFlag(CharacterInventory.limbSlots[i])) continue;
+
+                            targetSlot = i;
+
+                            //slot free, continue
+                            if (character.Inventory.Items[i] == null) continue;
+
+                            //try to move the existing item to LimbSlot.Any and continue if successful
+                            if (character.Inventory.TryPutItem(character.Inventory.Items[i], new List<InvSlotType>() { InvSlotType.Any })) continue;
+
+                            //if everything else fails, simply drop the existing item
+                            character.Inventory.Items[i].Drop();
+                        }
+                    }
+                }
+
+                targetItem.Pick(character, false, true);
+
+                if (targetSlot > -1 && character.Inventory.IsInLimbSlot(targetItem, InvSlotType.Any))
+                {
+                    character.Inventory.TryPutItem(targetItem, targetSlot, false);
+                }
+            }
+            else
+            {
+                if (goToObjective == null) 
+                {
+                    bool gettingDivingGear = itemName == "diving" || itemName == "Diving Gear";
+                    goToObjective = new AIObjectiveGoTo(moveToTarget, character, false, !gettingDivingGear);
+                }
+
+                goToObjective.TryComplete(deltaTime);
+            }
+            
+        }
+
+        /// <summary>
+        /// searches for an item that matches the desired item and adds a goto subobjective if one is found
+        /// </summary>
+        private void FindTargetItem()
+        {
+            if (itemName == null)
+            {
+                if (targetItem == null) canBeCompleted = false;
+                return;
+            }
+
+            float currDist = moveToTarget == null ? 0.0f : Vector2.DistanceSquared(moveToTarget.Position, character.Position);
+            
+            for (int i = 0; i < 10 && currSearchIndex < Item.ItemList.Count - 2; i++)
+            {
+                currSearchIndex++;
+
+                var item = Item.ItemList[currSearchIndex];
+
+                if (item.CurrentHull == null || item.Condition <= 0.0f) continue;
+                if (IgnoreContainedItems && item.Container != null) continue;
+                if (item.Name != itemName && !item.HasTag(itemName)) continue;
+
+                //if the item is inside a character's inventory, don't steal it
+                if (item.ParentInventory is CharacterInventory) continue;
+
+                //if the item is inside an item, which is inside a character's inventory, don't steal it
+                if (item.ParentInventory != null && item.ParentInventory.Owner is Item)
+                {
+                    if (((Item)item.ParentInventory.Owner).ParentInventory is CharacterInventory) continue;
+                }
+
+                //ignore if item is further away than the currently targeted item
+                Item rootContainer = item.GetRootContainer();
+                if (moveToTarget != null && Vector2.DistanceSquared((rootContainer ?? item).Position, character.Position) > currDist) continue;
+                
+                targetItem = item;
+                moveToTarget = rootContainer ?? item;
+            }
+
+            //if searched through all the items and a target wasn't found, can't be completed
+            if (currSearchIndex >= Item.ItemList.Count && targetItem == null) canBeCompleted = false;
+        }
+                
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            AIObjectiveGetItem getItem = otherObjective as AIObjectiveGetItem;
+            if (getItem == null) return false;
+            return (getItem.itemName == itemName);
+        }
+
+        public override bool IsCompleted()
+        {
+            if (itemName!=null)
+            {
+                return character.Inventory.FindItem(itemName) != null;
+            }
+            else if (targetItem!= null)
+            {
+                return character.Inventory.Items.Contains(targetItem);
+            }
+            else
+            {
+                return false;
+            }
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveGoTo.cs

@@ -0,0 +1,150 @@
+using Barotrauma.Items.Components;
+using FarseerPhysics;
+using Microsoft.Xna.Framework;
+using System;
+
+namespace Barotrauma
+{
+    class AIObjectiveGoTo : AIObjective
+    {
+        private Entity target;
+
+        private Vector2 targetPos;
+
+        private bool repeat;
+
+        //how long until the path to the target is declared unreachable
+        private float waitUntilPathUnreachable;
+
+        private bool getDivingGearIfNeeded;
+
+        public override bool CanBeCompleted
+        {
+            get
+            {
+                if (repeat || waitUntilPathUnreachable > 0.0f) return true;
+                var pathSteering = character.AIController.SteeringManager as IndoorsSteeringManager;
+
+                //path doesn't exist (= hasn't been searched for yet), assume for now that the target is reachable
+                if (pathSteering.CurrentPath == null) return true;
+
+                return (!pathSteering.CurrentPath.Unreachable);
+            }
+        }
+
+        public Entity Target
+        {
+            get { return target; }
+        }
+
+        public AIObjectiveGoTo(Entity target, Character character, bool repeat = false, bool getDivingGearIfNeeded = true)
+            : base (character, "")
+        {
+            this.target = target;
+            this.repeat = repeat;
+
+            waitUntilPathUnreachable = 5.0f;
+            this.getDivingGearIfNeeded = getDivingGearIfNeeded;
+        }
+
+
+        public AIObjectiveGoTo(Vector2 simPos, Character character, bool repeat = false, bool getDivingGearIfNeeded = true)
+            : base(character, "")
+        {
+            this.targetPos = simPos;
+            this.repeat = repeat;
+
+            waitUntilPathUnreachable = 5.0f;
+            this.getDivingGearIfNeeded = getDivingGearIfNeeded;
+        }
+
+        protected override void Act(float deltaTime)
+        {
+            if (target == character)
+            {
+                character.AIController.SteeringManager.Reset();
+
+                return;
+            }
+
+            waitUntilPathUnreachable -= deltaTime;
+
+            if (character.SelectedConstruction!=null && character.SelectedConstruction.GetComponent<Ladder>()==null)
+            {
+                character.SelectedConstruction = null;
+            }
+
+            if (target != null) character.AIController.SelectTarget(target.AiTarget);
+
+            Vector2 currTargetPos = Vector2.Zero;
+
+            if (target == null)
+            {
+                currTargetPos = targetPos;
+            }
+            else
+            {
+                currTargetPos = target.SimPosition;
+                
+                //if character is outside the sub and target isn't, transform the position
+                if (character.Submarine != null && target.Submarine == null)
+                {
+                    currTargetPos -= character.Submarine.SimPosition;
+                }
+            }
+
+            if (Vector2.Distance(currTargetPos, character.SimPosition) < 1.0f)
+            {
+                character.AIController.SteeringManager.Reset();
+                character.AnimController.TargetDir = currTargetPos.X > character.SimPosition.X ? Direction.Right : Direction.Left;
+            }
+            else
+            {
+                character.AIController.SteeringManager.SteeringSeek(currTargetPos);
+
+                var indoorsSteering = character.AIController.SteeringManager as IndoorsSteeringManager;
+
+                if (indoorsSteering.CurrentPath==null || indoorsSteering.CurrentPath.Unreachable)
+                {
+                    indoorsSteering.SteeringWander();
+                }
+                else if (getDivingGearIfNeeded && indoorsSteering.CurrentPath != null && indoorsSteering.CurrentPath.HasOutdoorsNodes)
+                {
+                    AddSubObjective(new AIObjectiveFindDivingGear(character, true));
+                }
+            }
+        }
+
+        public override bool IsCompleted()
+        {
+            if (repeat) return false;
+
+            bool completed = false;
+
+            float allowedDistance = 0.5f;
+            var item = target as Item;
+
+            if (item != null)
+            {
+                allowedDistance = Math.Max(ConvertUnits.ToSimUnits(item.PickDistance), allowedDistance);
+                if (item.IsInsideTrigger(character.WorldPosition)) completed = true;
+            }
+
+            completed = completed || Vector2.Distance(target != null ? target.SimPosition : targetPos, character.SimPosition) < allowedDistance;
+
+            if (completed) character.AIController.SteeringManager.Reset();
+
+            return completed;
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            AIObjectiveGoTo objective = otherObjective as AIObjectiveGoTo;
+            if (objective == null) return false;
+
+            if (objective.target == target) return true;
+
+            return (objective.targetPos == targetPos);
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveIdle.cs

@@ -0,0 +1,149 @@
+using Microsoft.Xna.Framework;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Barotrauma
+{
+    class AIObjectiveIdle : AIObjective
+    {
+        const float WallAvoidDistance = 150.0f;
+
+        AITarget currentTarget;
+        private float newTargetTimer;
+
+        public AIObjectiveIdle(Character character) : base(character, "")
+        {
+
+        }
+
+        public override float GetPriority(Character character)
+        {
+            return 1.0f;
+        }
+
+        protected override void Act(float deltaTime)
+        {
+
+            var pathSteering = character.AIController.SteeringManager as IndoorsSteeringManager;
+
+            if (pathSteering==null)
+            {
+                return;
+            }
+
+            if (newTargetTimer <= 0.0f)
+            {
+                currentTarget = FindRandomTarget();
+
+                if (currentTarget != null)
+                {
+                    Vector2 pos = character.SimPosition;
+                    if (character != null && character.Submarine == null) pos -= Submarine.MainSub.SimPosition;
+                    
+                    var path = pathSteering.PathFinder.FindPath(pos, currentTarget.SimPosition);
+                    if (path.Cost > 200.0f && character.AnimController.CurrentHull!=null) return;
+
+                    pathSteering.SetPath(path);
+                }
+
+
+                newTargetTimer = currentTarget == null ? 5.0f : 15.0f;
+            }
+            
+            newTargetTimer -= deltaTime;
+
+                  
+            //wander randomly 
+            // - if reached the end of the path 
+            // - if the target is unreachable
+            // - if the path requires going outside
+            if (pathSteering==null || (pathSteering.CurrentPath != null && 
+                (pathSteering.CurrentPath.NextNode == null || pathSteering.CurrentPath.Unreachable || pathSteering.CurrentPath.HasOutdoorsNodes)))
+            {
+                //steer away from edges of the hull
+                if (character.AnimController.CurrentHull!=null)
+                {
+                    float leftDist = character.Position.X - character.AnimController.CurrentHull.Rect.X;
+                    float rightDist = character.AnimController.CurrentHull.Rect.Right - character.Position.X;
+
+                    if (leftDist < WallAvoidDistance && rightDist < WallAvoidDistance)
+                    {
+                        if (Math.Abs(rightDist - leftDist) > WallAvoidDistance / 2)
+                        {
+                            pathSteering.SteeringManual(deltaTime, Vector2.UnitX * Math.Sign(rightDist - leftDist));
+                        }
+                        else
+                        {
+                            pathSteering.Reset();
+                            return;
+                        }
+                    }
+                    else if (leftDist < WallAvoidDistance)
+                    {
+                        pathSteering.SteeringManual(deltaTime, Vector2.UnitX * (WallAvoidDistance-leftDist)/WallAvoidDistance);
+                        pathSteering.WanderAngle = 0.0f;
+                        return;
+                    }
+                    else if (rightDist < WallAvoidDistance)
+                    {
+                        pathSteering.SteeringManual(deltaTime, -Vector2.UnitX * (WallAvoidDistance-rightDist)/WallAvoidDistance);
+                        pathSteering.WanderAngle = MathHelper.Pi;
+                        return;
+                    }
+                }
+
+                if (character.AnimController.InWater)
+                {
+                    character.AIController.SteeringManager.SteeringManual(deltaTime, new Vector2(0.0f, 0.5f));
+                }
+                else
+                {
+                    character.AIController.SteeringManager.SteeringWander();
+                    //reset vertical steering to prevent dropping down from platforms etc
+                    character.AIController.SteeringManager.ResetY();
+                }
+
+                return;                
+            }
+ 
+            if (currentTarget == null) return;
+            character.AIController.SteeringManager.SteeringSeek(currentTarget.SimPosition, 2.0f);
+        }
+
+        private AITarget FindRandomTarget()
+        {
+            if (Rand.Int(5)==1)
+            {
+                var idCard = character.Inventory.FindItem("ID Card");
+                if (idCard==null) return null;
+
+                foreach (WayPoint wp in WayPoint.WayPointList)
+                {
+                    if (wp.SpawnType != SpawnType.Human || wp.CurrentHull==null) continue;
+                 
+                    foreach (string tag in wp.IdCardTags)
+                    {
+                        if (idCard.HasTag(tag)) return wp.CurrentHull.AiTarget;
+                    }
+                }
+            }
+            else
+            {
+                List<Hull> targetHulls = new List<Hull>(Hull.hullList);
+                //ignore all hulls with fires or water in them
+                targetHulls.RemoveAll(h => h.FireSources.Any() || (h.Volume/h.FullVolume)>0.1f);
+                if (!targetHulls.Any()) return null;
+
+                return targetHulls[Rand.Range(0, targetHulls.Count)].AiTarget;
+            }
+
+            return null;
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            return (otherObjective is AIObjectiveIdle);
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveManager.cs

@@ -0,0 +1,95 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Barotrauma
+{
+    class AIObjectiveManager
+    {
+        public const float OrderPriority = 50.0f;
+
+        private List<AIObjective> objectives;
+
+        private Character character;
+
+        private AIObjective currentObjective;
+        
+        public AIObjective CurrentObjective
+        {
+            get
+            {
+                if (currentObjective != null) return currentObjective;
+                return objectives.Any() ? objectives[0] : null;
+            }
+        }
+
+        public AIObjectiveManager(Character character)
+        {
+            this.character = character;
+
+            objectives = new List<AIObjective>();
+        }
+
+        public void AddObjective(AIObjective objective)
+        {
+            if (objectives.Find(o => o.IsDuplicate(objective)) != null) return;
+
+            objectives.Add(objective);
+        }
+
+        public float GetCurrentPriority(Character character)
+        {
+            if (currentObjective != null) return OrderPriority;
+            return (CurrentObjective == null) ? 0.0f : CurrentObjective.GetPriority(character);
+        }
+
+        public void UpdateObjectives()
+        {
+            if (!objectives.Any()) return;
+
+            //remove completed objectives and ones that can't be completed
+            objectives = objectives.FindAll(o => !o.IsCompleted() && o.CanBeCompleted);
+
+            //sort objectives according to priority
+            objectives.Sort((x, y) => y.GetPriority(character).CompareTo(x.GetPriority(character)));
+        }
+
+        public void DoCurrentObjective(float deltaTime)
+        {
+            if (currentObjective != null && (!objectives.Any() || objectives[0].GetPriority(character) < OrderPriority))
+            {
+                currentObjective.TryComplete(deltaTime);
+                return;
+            }
+
+            if (!objectives.Any()) return;
+            objectives[0].TryComplete(deltaTime);
+        }
+
+        public void SetOrder(Order order, string option)
+        {
+            if (order == null) return;
+
+            currentObjective = null;
+
+            switch (order.Name.ToLowerInvariant())
+            {
+                case "follow":
+                    currentObjective = new AIObjectiveGoTo(Character.Controlled, character, true);
+                    break;
+                case "wait":
+                    currentObjective = new AIObjectiveGoTo(character, character, true);
+                    break;
+                case "fixleaks":
+                case "fix leaks":
+                    currentObjective = new AIObjectiveFixLeaks(character);
+                    break;
+                default:
+                    if (order.TargetItem == null) return;
+
+                    currentObjective = new AIObjectiveOperateItem(order.TargetItem, character, option, null, order.UseController);
+
+                    break;
+            }
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveOperateItem.cs

@@ -0,0 +1,96 @@
+using Barotrauma.Items.Components;
+using Microsoft.Xna.Framework;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Barotrauma
+{
+    class AIObjectiveOperateItem : AIObjective
+    {
+        private ItemComponent component, controller;
+
+        private Entity operateTarget;
+
+        private bool isCompleted;
+
+        private bool canBeCompleted;
+
+        public override bool CanBeCompleted
+        {
+            get
+            {
+                return canBeCompleted;
+            }
+        }
+
+        public Entity OperateTarget
+        {
+            get { return operateTarget; }
+        }
+
+        public AIObjectiveOperateItem(ItemComponent item, Character character, string option, Entity operateTarget = null, bool useController = false)
+            :base (character, option)
+        {
+            this.component = item;
+
+            this.operateTarget = operateTarget;
+
+            if (useController)
+            {
+                var controllers = item.Item.GetConnectedComponents<Controller>();
+                if (controllers.Any()) controller = controllers[0];
+            }
+
+
+            canBeCompleted = true;
+        }
+
+        protected override void Act(float deltaTime)
+        {
+            ItemComponent target = controller == null ? component : controller;
+
+            if (target.CanBeSelected)
+            { 
+                if (Vector2.Distance(character.Position, target.Item.Position) < target.Item.PickDistance
+                    || target.Item.IsInsideTrigger(character.WorldPosition))
+                {
+                    if (character.SelectedConstruction != target.Item && target.CanBeSelected)
+                    {
+                        target.Item.Pick(character, false, true);
+                    }
+
+                    if (component.AIOperate(deltaTime, character, this)) isCompleted = true;
+                    return;
+                }
+
+                AddSubObjective(new AIObjectiveGoTo(target.Item, character));
+            }
+            else
+            {
+                if (!character.Inventory.Items.Contains(component.Item))
+                {
+                    AddSubObjective(new AIObjectiveGetItem(character, component.Item, true));
+                }
+                else
+                {
+                    if (component.AIOperate(deltaTime, character, this)) isCompleted = true;
+                }
+            }
+        }
+
+        public override bool IsCompleted()
+        {
+            return isCompleted;
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            AIObjectiveOperateItem operateItem = otherObjective as AIObjectiveOperateItem;
+            if (operateItem == null) return false;
+
+            return (operateItem.component == component);
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveRescue.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Text;
+using Microsoft.Xna.Framework;
+
+namespace Barotrauma
+{
+    class AIObjectiveRescue : AIObjective
+    {
+        private readonly Character targetCharacter;
+
+        public AIObjectiveRescue(Character character, Character targetCharacter)
+            : base (character, "")
+        {
+            Debug.Assert(character != targetCharacter);
+
+            this.targetCharacter = targetCharacter;
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            AIObjectiveRescue rescueObjective = otherObjective as AIObjectiveRescue;
+            return rescueObjective != null && rescueObjective.targetCharacter == targetCharacter;
+        }
+
+        public override float GetPriority(Character character)
+        {
+            if (targetCharacter.AnimController.CurrentHull == null) return 0.0f;
+
+            float distance = Vector2.DistanceSquared(character.WorldPosition, targetCharacter.WorldPosition);
+
+            return targetCharacter.IsDead ? 1000.0f / distance : 10000.0f / distance;
+        }
+
+    }
+}

Barotrauma/Source/Characters/AI/Objectives/AIObjectiveRescureAll.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Barotrauma
+{
+    class AIObjectiveRescueAll : AIObjective
+    {
+        private List<Character> rescueTargets;
+        
+        public AIObjectiveRescueAll(Character character)
+            : base (character, "")
+        {
+            rescueTargets = new List<Character>();
+        }
+
+        public override bool IsDuplicate(AIObjective otherObjective)
+        {
+            return true;
+        }
+
+        public override float GetPriority(Character character)
+        {
+            GetRescueTargets();
+
+            //if there are targets to rescue, the priority is slightly less 
+            //than the priority of explicit orders given to the character
+            return rescueTargets.Any() ? AIObjectiveManager.OrderPriority - 5.0f : 0.0f;
+        }
+
+        private void GetRescueTargets()
+        {
+            rescueTargets = Character.CharacterList.FindAll(c => 
+                c.AIController is HumanAIController &&
+                c != character &&
+                (c.IsDead || c.IsUnconscious) &&
+                c.AnimController.CurrentHull != null &&
+                AIObjectiveFindSafety.GetHullSafety(c.AnimController.CurrentHull, c) < 50.0f);
+        }
+
+        protected override void Act(float deltaTime)
+        {
+            foreach (Character target in rescueTargets)
+            {
+                AddSubObjective(new AIObjectiveRescue(character, target));
+            }
+        }
+    }
+}

Barotrauma/Source/Characters/AI/Order.cs

@@ -0,0 +1,139 @@
+using Barotrauma.Items.Components;
+using Microsoft.Xna.Framework;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Xml.Linq;
+
+namespace Barotrauma
+{
+    class Order
+    {
+        private static string ConfigFile = Path.Combine("Content", "Orders.xml");
+
+        public static List<Order> PrefabList;
+
+        public readonly string Name;
+        public readonly string DoingText;
+
+        public readonly Sprite SymbolSprite;
+
+        public readonly Type ItemComponentType;
+        public readonly string ItemName;
+
+        public readonly Color Color;
+
+        public readonly bool UseController;
+
+        public ItemComponent TargetItem;
+
+        public readonly string[] Options;
+
+        static Order()
+        {
+            PrefabList = new List<Order>();
+
+            XDocument doc = ToolBox.TryLoadXml(ConfigFile);
+            if (doc == null || doc.Root == null) return;
+
+            foreach (XElement orderElement in doc.Root.Elements())
+            {
+                if (orderElement.Name.ToString().ToLowerInvariant() != "order") continue;
+
+                PrefabList.Add(new Order(orderElement));
+            }
+
+            //PrefabList.Add(new Order("Follow", "Following"));
+
+            //PrefabList.Add(new Order("Dismiss", "Dismissed"));
+
+            //PrefabList.Add(new Order("Wait", "Wait"));
+
+            //PrefabList.Add(new Order("Operate Reactor", "Operating reactor", typeof(Reactor), new string[] {"Power up", "Shutdown"}));
+            //PrefabList.Add(new Order("Operate Railgun", "Operating railgun", typeof(Turret), new string[] { "Fire at will", "Hold fire" }));
+
+
+        }
+
+        private Order(XElement orderElement)
+        {
+            Name = ToolBox.GetAttributeString(orderElement, "name", "Name not found");
+            DoingText = ToolBox.GetAttributeString(orderElement, "doingtext", "");
+
+            string targetItemName = ToolBox.GetAttributeString(orderElement, "targetitemtype", "");
+
+            if (!string.IsNullOrWhiteSpace(targetItemName))
+            {
+                try
+                {
+                    ItemComponentType = Type.GetType("Barotrauma.Items.Components." + targetItemName, true, true);
+                }
+
+                catch (Exception e)
+                {
+                    DebugConsole.ThrowError("Error in " + ConfigFile + ", item component type " + targetItemName + " not found", e);
+                }
+            }
+
+            ItemName = ToolBox.GetAttributeString(orderElement, "targetitemname", "");
+
+            Color = new Color(ToolBox.GetAttributeVector4(orderElement, "color", new Vector4(1.0f, 1.0f, 1.0f, 1.0f)));
+
+            UseController = ToolBox.GetAttributeBool(orderElement, "usecontroller", false);
+
+            string optionStr = ToolBox.GetAttributeString(orderElement, "options", "");
+
+            if (string.IsNullOrWhiteSpace(optionStr))
+            {
+                Options = new string[0];
+            }
+            else
+            {
+                Options = optionStr.Split(',');
+
+                for (int i = 0; i<Options.Length; i++)
+                {
+                    Options[i] = Options[i].Trim();
+                }
+            }
+
+
+
+            foreach (XElement subElement in orderElement.Elements())
+            {
+                if (subElement.Name.ToString().ToLowerInvariant() != "sprite") continue;
+                SymbolSprite = new Sprite(subElement);
+                break;
+            }
+        }
+
+        private Order(string name, string doingText, Type itemComponentType, string[] parameters = null)
+        {
+            Name = name;
+            DoingText = doingText;
+            ItemComponentType = itemComponentType;
+            Options = parameters == null ? new string[0] : parameters;
+        }
+
+        public Order(Order prefab, ItemComponent targetItem)
+        {
+            Name                = prefab.Name;
+            DoingText           = prefab.DoingText;
+            ItemComponentType   = prefab.ItemComponentType;
+            Options             = prefab.Options;
+            SymbolSprite        = prefab.SymbolSprite;
+            Color               = prefab.Color;
+            UseController       = prefab.UseController;
+
+            TargetItem = targetItem;
+        }
+
+        private Order(string name, string doingText, string[] parameters = null)
+            :this (name,doingText, null, parameters)
+        {
+        }
+    }
+
+}

Barotrauma/Source/Characters/AI/PathFinder.cs

@@ -0,0 +1,387 @@
+using Microsoft.Xna.Framework;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Barotrauma
+{
+    class PathNode
+    {
+        private WayPoint wayPoint;
+
+        private int wayPointID;
+
+        public int state;
+
+        public PathNode Parent;
+        
+        private Vector2 position;
+
+        public float F,G,H;
+
+        public List<PathNode> connections;
+        public List<float> distances;
+        
+        public WayPoint Waypoint
+        {
+            get { return wayPoint; }
+        }
+
+        public Vector2 Position
+        {
+            get {return position;}
+        }
+
+        public PathNode(WayPoint wayPoint)
+        {
+            this.wayPoint = wayPoint;
+            this.position = wayPoint.SimPosition;
+            wayPointID = wayPoint.ID;
+
+            connections = new List<PathNode>();
+        }
+
+        public static List<PathNode> GenerateNodes(List<WayPoint> wayPoints)
+        {
+            var nodes = new Dictionary<int, PathNode>();
+            foreach (WayPoint wayPoint in wayPoints)
+            {
+                if (wayPoint == null) continue;
+                if (nodes.ContainsKey(wayPoint.ID))
+                {
+                    DebugConsole.ThrowError("Error in PathFinder.GenerateNodes (duplicate ID \"" + wayPoint.ID + "\")");
+                    continue;
+                }
+                nodes.Add(wayPoint.ID, new PathNode(wayPoint));
+            }
+
+            foreach (KeyValuePair<int,PathNode> node in nodes)
+            {
+                foreach (MapEntity linked in node.Value.wayPoint.linkedTo)
+                {
+                    PathNode connectedNode = null;
+                    nodes.TryGetValue(linked.ID, out connectedNode);
+                    if (connectedNode == null) continue;
+
+                    node.Value.connections.Add(connectedNode);                    
+                }
+            }
+
+            var nodeList = nodes.Values.ToList();
+            nodeList.RemoveAll(n => n.connections.Count == 0);
+            foreach (PathNode node in nodeList)
+            {
+                node.distances = new List<float>();
+                for (int i = 0; i< node.connections.Count; i++)
+                {
+                    node.distances.Add(Vector2.Distance(node.position, node.connections[i].position));
+                }                
+            }
+
+            return nodeList;            
+        }
+    }
+
+    class PathFinder
+    {
+        public delegate float? GetNodePenaltyHandler(PathNode node, PathNode prevNode);
+        public GetNodePenaltyHandler GetNodePenalty;
+
+        private List<PathNode> nodes;
+
+        private bool insideSubmarine;
+
+        public PathFinder(List<WayPoint> wayPoints, bool insideSubmarine = false)
+        {
+            nodes = PathNode.GenerateNodes(wayPoints.FindAll(w => w.MoveWithLevel != insideSubmarine));
+
+            foreach (WayPoint wp in wayPoints)
+            {
+                wp.linkedTo.CollectionChanged += WaypointLinksChanged;
+            }
+
+            this.insideSubmarine = insideSubmarine;
+        }
+
+        void WaypointLinksChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
+        {
+            if (Submarine.Unloading) return;
+
+            var waypoints = sender as IEnumerable<MapEntity>;
+
+            foreach (MapEntity me in waypoints)
+            {
+                WayPoint wp = me as WayPoint;
+                if (me == null) continue;
+
+                var node = nodes.Find(n => n.Waypoint == wp);
+                if (node == null) return;
+
+                if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Remove)
+                {
+                    for (int i = node.connections.Count - 1; i >= 0; i--)
+                    {
+                        //remove connection if the waypoint isn't connected anymore
+                        if (wp.linkedTo.FirstOrDefault(l => l == node.connections[i].Waypoint) == null)
+                        {
+                            node.connections.RemoveAt(i);
+                            node.distances.RemoveAt(i);
+                        }
+                    }
+                }
+                else if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Add)
+                {
+                    for (int i = 0; i < wp.linkedTo.Count; i++)
+                    {
+                        WayPoint connected = wp.linkedTo[i] as WayPoint;
+                        if (connected == null) continue;
+
+                        //already connected, continue
+                        if (node.connections.Any(n => n.Waypoint == connected)) continue;
+
+                        var matchingNode = nodes.Find(n => n.Waypoint == connected);
+                        if (matchingNode == null)
+                        {
+#if DEBUG
+                            DebugConsole.ThrowError("Waypoint connections were changed, no matching path node found in PathFinder");
+#endif
+                            return;
+                        }
+
+                        node.connections.Add(matchingNode);
+                        node.distances.Add(Vector2.Distance(node.Position, matchingNode.Position));
+                    }
+                }
+            }
+        }
+
+        public SteeringPath FindPath(Vector2 start, Vector2 end)
+        {
+            System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
+            sw.Start();
+            
+            float closestDist = 0.0f;
+            PathNode startNode = null;
+            foreach (PathNode node in nodes)
+            {
+                Vector2 nodePos = node.Position;
+                
+                float dist = System.Math.Abs(start.X - nodePos.X) +
+                    System.Math.Abs(start.Y - nodePos.Y) * 10.0f; //higher cost for vertical movement
+
+                //prefer nodes that are closer to the end position
+                dist += Vector2.Distance(end, nodePos) / 10.0f;
+
+                if (dist<closestDist || startNode==null)
+                {
+                    //if searching for a path inside the sub, make sure the waypoint is visible
+                    if (insideSubmarine)
+                    {
+                        var body = Submarine.PickBody(
+                            start, node.Waypoint.SimPosition, null, 
+                            Physics.CollisionWall | Physics.CollisionLevel | Physics.CollisionStairs | Physics.CollisionPlatform);
+
+                        if (body != null)
+                        {
+                            if (body.UserData is Structure && !((Structure)body.UserData).IsPlatform) continue;
+                            if (body.UserData is Item && body.FixtureList[0].CollisionCategories.HasFlag(Physics.CollisionWall)) continue;
+
+                        }
+                    }
+
+                    closestDist = dist;
+                    startNode = node;
+                }
+            }
+
+            if (startNode == null)
+            {
+                DebugConsole.NewMessage("Pathfinding error, couldn't find a start node", Color.DarkRed);
+
+                return new SteeringPath();
+            }
+            
+            closestDist = 0.0f;
+            PathNode endNode = null;
+            foreach (PathNode node in nodes)
+            {
+                Vector2 nodePos = node.Position;
+
+                float dist = Vector2.Distance(end, nodePos);
+                if (dist < closestDist || endNode == null)
+                {
+                    //if searching for a path inside the sub, make sure the waypoint is visible
+                    if (insideSubmarine)
+                    {
+                        var body = Submarine.CheckVisibility(end, node.Waypoint.SimPosition);
+                        if (body != null && body.UserData is Structure) continue;
+                    }
+
+                    closestDist = dist;
+                    endNode = node;
+                }
+            }
+
+            if (endNode == null)
+            {
+                DebugConsole.NewMessage("Pathfinding error, couldn't find an end node", Color.DarkRed);
+                return new SteeringPath();
+            }
+
+
+            var path =  FindPath(startNode,endNode);
+
+            sw.Stop();
+            System.Diagnostics.Debug.WriteLine("findpath: " + sw.ElapsedMilliseconds+" ms");
+
+            return path;
+        }
+
+        public SteeringPath FindPath(WayPoint start, WayPoint end)
+        {
+            PathNode startNode=null, endNode=null;
+            foreach (PathNode node in nodes)
+            {
+                if (node.Waypoint == start)
+                {
+                    startNode = node;
+                    if (endNode != null) break;
+                }
+                if (node.Waypoint == end)
+                {
+                    endNode = node;
+                    if (startNode != null) break;
+                }
+            }
+
+
+            if (startNode == null || endNode == null)
+            {
+                DebugConsole.NewMessage("Pathfinding error, couldn't find matching pathnodes to waypoints", Color.DarkRed);
+                return new SteeringPath();
+            }
+
+            return FindPath(startNode, endNode);
+        }
+
+        private SteeringPath FindPath(PathNode start, PathNode end)
+        {
+            if (start == end)
+            {
+                var path1 = new SteeringPath();
+                path1.AddNode(start.Waypoint);
+
+                return path1;
+            }
+
+            foreach (PathNode node in nodes)
+            {
+                node.state = 0;
+                node.F = 0.0f;
+                node.G = 0.0f;
+                node.H = 0.0f;
+            }
+              
+            start.state = 1;
+            while (true)
+            {
+
+                PathNode currNode = null;
+                float dist = 10000.0f;
+                foreach (PathNode node in nodes)
+                {
+                    if (node.state != 1) continue;
+                    if (node.F < dist)
+                    {
+                        dist = node.F;
+                        currNode = node;
+                    }
+                }
+
+                if (currNode == null || currNode == end) break;
+
+                currNode.state = 2;
+
+                for (int i = 0; i < currNode.connections.Count; i++)
+                {
+                    PathNode nextNode = currNode.connections[i];
+                    
+                    //a node that hasn't been searched yet
+                    if (nextNode.state==0)
+                    {
+                        nextNode.H = Vector2.Distance(nextNode.Position,end.Position);
+
+                        if (GetNodePenalty != null)
+                        {
+                            float? nodePenalty =GetNodePenalty(currNode, nextNode);
+                            if (nodePenalty == null)
+                            {
+                                nextNode.state = -1;
+                                continue;
+                            }
+                            nextNode.H += (float)nodePenalty;
+                        }
+
+                        nextNode.G = currNode.G + currNode.distances[i];
+                        nextNode.F = nextNode.G + nextNode.H;
+                        nextNode.Parent = currNode;
+                        nextNode.state = 1;
+                    }
+                    //node that has been searched
+                    else if (nextNode.state==1)
+                    {
+                        float tempG = currNode.G + currNode.distances[i];
+                        //only use if this new route is better than the 
+                        //route the node was a part of
+                        if (tempG < nextNode.G)
+                        {
+                            nextNode.G = tempG;
+                            nextNode.F = nextNode.G + nextNode.H;
+                            nextNode.Parent = currNode;
+                        }
+                    }
+                }
+            }
+
+            if (end.state == 0 || end.Parent == null)
+            {
+                //path not found
+                return new SteeringPath(true);
+            }
+
+            SteeringPath path = new SteeringPath();
+            List<WayPoint> finalPath = new List<WayPoint>();
+
+            PathNode pathNode = end;
+            while (pathNode != start && pathNode != null)
+            {
+                finalPath.Add(pathNode.Waypoint);
+
+                //there was one bug report that seems to have been caused by this loop never terminating:
+                //couldn't reproduce or figure out what caused it, but here's a workaround that prevents the game from crashing in case it happens again
+                if (finalPath.Count > nodes.Count)
+                {
+                    DebugConsole.ThrowError("Pathfinding error: constructing final path failed");
+                    return new SteeringPath(true);
+                }
+
+                path.Cost += pathNode.F;
+                pathNode = pathNode.Parent;
+            }
+
+            finalPath.Add(start.Waypoint);
+
+            finalPath.Reverse();
+
+            foreach (WayPoint wayPoint in finalPath)
+            {
+                path.AddNode(wayPoint);
+            }
+            
+                
+            return path;
+        }
+    }
+}
+
+
+

Barotrauma/Source/Characters/AI/SteeringManager.cs

@@ -0,0 +1,190 @@
+using System;
+using Microsoft.Xna.Framework;
+using FarseerPhysics.Dynamics;
+
+namespace Barotrauma
+{
+    class SteeringManager
+    {
+        protected const float CircleDistance = 2.5f;
+        protected const float CircleRadius = 0.3f;
+
+        protected const float RayCastInterval = 0.5f;
+
+        protected ISteerable host;
+
+        private Vector2 steering;
+
+        //the steering amount when avoiding obstacles
+        //(needs a separate variable because it's only updated when a raycast is done to detect any nearby obstacles)
+        private Vector2 avoidSteering;
+        private float rayCastTimer;
+
+        private float wanderAngle;        
+        
+        public float WanderAngle
+        {
+            get { return wanderAngle; }
+            set { wanderAngle = value; }
+        }
+
+        public SteeringManager(ISteerable host)
+        {
+            this.host = host;
+
+            wanderAngle = Rand.Range(0.0f, MathHelper.TwoPi);
+        }
+
+        public void SteeringSeek(Vector2 targetSimPos, float speed = 1.0f)
+        {
+            steering += DoSteeringSeek(targetSimPos, speed);
+        }
+
+        public void SteeringWander(float speed = 1.0f)
+        {
+            steering += DoSteeringWander(speed);
+        }
+
+        public void SteeringAvoid(float deltaTime, float speed)
+        {
+            steering += DoSteeringAvoid(deltaTime, speed);
+        }
+
+        public void SteeringManual(float deltaTime, Vector2 velocity)
+        {
+            steering += velocity;
+        }
+
+        public void Reset()
+        {
+            steering = Vector2.Zero;
+        }
+
+        public void ResetX()
+        {
+            steering.X = 0.0f;
+        }
+
+        public void ResetY()
+        {
+            steering.Y = 0.0f;
+        }
+
+        public virtual void Update(float speed = 1.0f)
+        {
+            if (steering == Vector2.Zero || !MathUtils.IsValid(steering))
+            {
+                steering = Vector2.Zero;
+                host.Steering = Vector2.Zero;
+                return;
+            }
+
+            float steeringSpeed = steering.Length();
+            if (steeringSpeed>speed)
+            {
+               steering = Vector2.Normalize(steering) * Math.Abs(speed);
+            }
+
+            host.Steering = steering;
+        }
+
+        protected virtual Vector2 DoSteeringSeek(Vector2 target, float speed = 1.0f)
+        {
+            Vector2 targetVel = target - host.SimPosition;
+
+            if (targetVel.LengthSquared() < 0.00001f) return Vector2.Zero;
+
+            targetVel = Vector2.Normalize(targetVel) * speed;
+            Vector2 newSteering = targetVel - host.Steering;
+
+            if (newSteering==Vector2.Zero) return Vector2.Zero;
+
+            float steeringSpeed = (newSteering + host.Steering).Length();
+            if (steeringSpeed > Math.Abs(speed))
+            {
+                newSteering = Vector2.Normalize(newSteering)*Math.Abs(speed);
+            }
+
+            return newSteering;
+        }
+
+        protected virtual Vector2 DoSteeringWander(float speed = 1.0f)
+        {
+            Vector2 circleCenter = (host.Steering == Vector2.Zero) ? new Vector2(speed, 0.0f) : host.Steering;
+            circleCenter = Vector2.Normalize(circleCenter) * CircleDistance;
+
+            Vector2 displacement = new Vector2(
+                (float)Math.Cos(wanderAngle),
+                (float)Math.Sin(wanderAngle));
+            displacement = displacement * CircleRadius;
+
+            float angleChange = 1.5f;
+            
+            wanderAngle += Rand.Range(0.0f, 1.0f) * angleChange - angleChange * 0.5f;
+
+            Vector2 newSteering = circleCenter + displacement;
+            float steeringSpeed = (newSteering + host.Steering).Length();
+            if (steeringSpeed > speed)
+            {
+                newSteering = Vector2.Normalize(newSteering) * speed;
+            }
+
+            return newSteering;
+        }
+
+        protected virtual Vector2 DoSteeringAvoid(float deltaTime, float speed = 1.0f)
+        {
+            if (steering == Vector2.Zero || host.Steering == Vector2.Zero) return Vector2.Zero;
+
+            float maxDistance = 2.0f;
+
+            Vector2 ahead = host.SimPosition + Vector2.Normalize(host.Steering) * maxDistance;
+
+            if (rayCastTimer <= 0.0f)
+            {
+                rayCastTimer = RayCastInterval;
+                Body closestBody = Submarine.CheckVisibility(host.SimPosition, ahead);
+                if (closestBody == null)
+                {
+                    avoidSteering = Vector2.Zero;
+                    return Vector2.Zero;
+                }
+                else
+                {
+                    Structure closestStructure = closestBody.UserData as Structure;
+                    if (closestStructure != null)
+                    {
+                        Vector2 obstaclePosition = Submarine.LastPickedPosition;
+                        if (closestStructure.IsHorizontal)
+                        {
+                            obstaclePosition.Y = closestStructure.SimPosition.Y;
+                        }
+                        else
+                        {
+                            obstaclePosition.X = closestStructure.SimPosition.X;
+                        }
+
+                        avoidSteering = Vector2.Normalize(Submarine.LastPickedPosition - obstaclePosition);
+                    }
+                    else if (closestBody.UserData is Item)
+                    {
+                        Item item = (Item)closestBody.UserData;
+                        avoidSteering = Vector2.Normalize(Submarine.LastPickedPosition - item.SimPosition);
+                    }
+                    else
+                    {
+                        avoidSteering = Vector2.Normalize(host.SimPosition - Submarine.LastPickedPosition);
+                    }
+                }
+
+            }
+            else
+            {
+                rayCastTimer -= deltaTime;
+            }
+
+            return avoidSteering * speed;
+        }
+
+    }
+}

Barotrauma/Source/Characters/AI/SteeringPath.cs

@@ -0,0 +1,104 @@
+using System.Collections.Generic;
+using Microsoft.Xna.Framework;
+
+namespace Barotrauma
+{
+    class SteeringPath
+    {
+        private List<WayPoint> nodes;
+
+        int currentIndex;
+
+        public bool Unreachable
+        {
+            get;
+            set;
+        }
+
+        public SteeringPath(bool unreachable = false)
+        {
+            nodes = new List<WayPoint>();
+            Unreachable = unreachable;
+        }
+
+        public void AddNode(WayPoint node)
+        {
+            if (node == null) return;
+            nodes.Add(node);
+
+            if (node.CurrentHull == null) HasOutdoorsNodes = true;
+        }
+        
+        public bool HasOutdoorsNodes
+        {
+            get;
+            private set;
+        }
+
+        public int CurrentIndex
+        {
+            get { return currentIndex; }
+        }
+
+        public float Cost
+        {
+            get;
+            set;
+        }
+
+        public WayPoint PrevNode
+        {
+            get 
+            {
+                if (currentIndex-1 < 0 || currentIndex-1 > nodes.Count - 1) return null;
+                return nodes[currentIndex-1]; 
+            }
+        }
+
+        public WayPoint CurrentNode
+        {
+            get 
+            {
+                if (currentIndex < 0 || currentIndex > nodes.Count - 1) return null;
+                return nodes[currentIndex]; 
+            }
+        }
+
+        public List<WayPoint> Nodes
+        {
+            get { return nodes; }
+        }
+
+        public WayPoint NextNode
+        {
+            get
+            {
+                if (currentIndex+1 < 0 || currentIndex+1 > nodes.Count - 1) return null;
+                return nodes[currentIndex+1];
+            }
+        }
+
+        public bool Finished
+        {
+            get { return currentIndex >= nodes.Count; }
+        }
+
+        public void SkipToNextNode()
+        {
+            currentIndex++;
+        }
+
+        public WayPoint CheckProgress(Vector2 simPosition, float minSimDistance = 0.1f)
+        {
+            if (nodes.Count == 0 || currentIndex>nodes.Count-1) return null;
+            if (Vector2.Distance(simPosition, nodes[currentIndex].SimPosition) < minSimDistance) currentIndex++;
+
+            return CurrentNode;
+        }
+
+        public void ClearPath()
+        {
+            nodes.Clear();
+        }
+    }
+}