- Added "LevelTriggers", areas that apply statuseffects and/or damage to entities. Atm can only be attached to background sprites.

- Moved background sprites to the shared project.
- The debug textures of physics bodies have a maximum size of 128x128 pixels to prevent large bodies from taking up excessive amounts of memory.
- Attacks can be set to only affect humans.

Barotrauma/BarotraumaShared/Source/Map/Levels/LevelTrigger.cs

@@ -0,0 +1,134 @@
+using FarseerPhysics;
+using FarseerPhysics.Dynamics;
+using Microsoft.Xna.Framework;
+using System;
+using System.Collections.Generic;
+using System.Xml.Linq;
+
+namespace Barotrauma
+{
+    partial class LevelTrigger
+    {
+        private PhysicsBody physicsBody;
+
+        /// <summary>
+        /// Effects applied to entities that are inside the trigger
+        /// </summary>
+        private List<StatusEffect> statusEffects = new List<StatusEffect>();
+
+        /// <summary>
+        /// Attacks applied to entities that are inside the trigger
+        /// </summary>
+        private List<Attack> attacks = new List<Attack>();
+
+        private List<Entity> triggerers = new List<Entity>();
+
+        public Vector2 WorldPosition
+        {
+            get { return ConvertUnits.ToDisplayUnits(physicsBody.Position); }
+            set { physicsBody.SetTransform(ConvertUnits.ToSimUnits(value), physicsBody.Rotation); }
+        }
+
+        public float Rotation
+        {
+            get { return physicsBody.Rotation; }
+            set { physicsBody.SetTransform(physicsBody.Position, value); }
+        }
+
+        public PhysicsBody PhysicsBody
+        {
+            get { return physicsBody; }
+        }
+
+        public LevelTrigger(XElement element, Vector2 position, float rotation, float scale = 1.0f)
+        {
+            physicsBody = new PhysicsBody(element, scale);
+            physicsBody.CollisionCategories = Physics.CollisionLevel;
+            physicsBody.CollidesWith = Physics.CollisionCharacter | Physics.CollisionItem | Physics.CollisionProjectile | Physics.CollisionWall;
+            physicsBody.FarseerBody.OnCollision += PhysicsBody_OnCollision;
+            physicsBody.FarseerBody.OnSeparation += PhysicsBody_OnSeparation;
+            physicsBody.FarseerBody.IsSensor = true;
+            physicsBody.FarseerBody.IsStatic = true;
+            physicsBody.FarseerBody.IsKinematic = true;
+
+            physicsBody.SetTransform(ConvertUnits.ToSimUnits(position), rotation);
+            
+            foreach (XElement subElement in element.Elements())
+            {
+                switch (subElement.Name.ToString().ToLowerInvariant())
+                {
+                    case "statuseffect":
+                        statusEffects.Add(StatusEffect.Load(subElement));
+                        break;
+                    case "attack":
+                    case "damage":
+                        attacks.Add(new Attack(subElement));
+                        break;
+                }
+            }
+        }
+
+        private bool PhysicsBody_OnCollision(Fixture fixtureA, Fixture fixtureB, FarseerPhysics.Dynamics.Contacts.Contact contact)
+        {
+            Entity entity = GetEntity(fixtureB);
+            if (entity == null) return false;
+
+            if (!triggerers.Contains(entity))
+            {
+                triggerers.Add(entity);
+            }
+            return true;
+        }
+
+        private void PhysicsBody_OnSeparation(Fixture fixtureA, Fixture fixtureB)
+        {
+            Entity entity = GetEntity(fixtureB);
+            if (entity == null) return;
+
+            if (triggerers.Contains(entity))
+            {
+                triggerers.Remove(entity);
+            }
+        }
+
+        private Entity GetEntity(Fixture fixture)
+        {
+            if (fixture.Body == null || fixture.Body.UserData == null) return null;
+
+            var entity = fixture.Body.UserData as Entity;
+            if (entity != null) return entity;
+            
+            var limb = fixture.Body.UserData as Limb;
+            if (limb != null) return limb.character;
+
+            return null;
+        }
+
+        public void Update(float deltaTime)
+        {
+            foreach (Entity triggerer in triggerers)
+            {
+                foreach (StatusEffect effect in statusEffects)
+                {
+                    if (triggerer is Character)
+                    {
+                        effect.Apply(effect.type, deltaTime, triggerer, (Character)triggerer);
+                    }
+                    else if (triggerer is Item)
+                    {
+                        effect.Apply(effect.type, deltaTime, triggerer, ((Item)triggerer).AllPropertyObjects);
+                    }
+                }
+
+                IDamageable damageable = triggerer as IDamageable;
+                if (damageable != null)
+                {
+                    foreach (Attack attack in attacks)
+                    {
+                        attack.DoDamage(null, damageable, WorldPosition, deltaTime, false);
+                    }
+                }
+            }
+        }
+    }
+}