Simple MapEntity visibility culling (structures outside the camera view or items with nothing to render aren't drawn)

Could be optimized further, but already gives a pretty nice performance boost

Subsurface/Source/Map/Structure.cs

@@ -475,6 +475,15 @@ namespace Barotrauma
             if (convexHulls != null) convexHulls.ForEach(x => x.Remove());
         }
 
+        public override bool IsVisible(Rectangle WorldView)
+        {
+            Rectangle worldRect = WorldRect;
+
+            if (worldRect.X > WorldView.Right || worldRect.Right < WorldView.X) return false;
+            if (worldRect.Y < WorldView.Y - WorldView.Height || worldRect.Y - worldRect.Height > WorldView.Y) return false;
+
+            return true;
+        }
 
         public override void Draw(SpriteBatch spriteBatch, bool editing, bool back = true)
         {
@@ -514,7 +523,7 @@ namespace Barotrauma
                         spriteBatch,
                         new Vector2(rect.X + drawOffset.X, -(rect.Y + drawOffset.Y)),
                         new Vector2(rect.Width, rect.Height),
-                        Vector2.Zero, color, Point.Zero);
+                        color, Point.Zero);
                 }
             }
 
@@ -553,7 +562,7 @@ namespace Barotrauma
                         spriteBatch,
                         new Vector2(sections[i].rect.X + drawOffset.X, -(sections[i].rect.Y + drawOffset.Y)),
                         new Vector2(sections[i].rect.Width, sections[i].rect.Height),
-                        Vector2.Zero, color,
+                        color,
                         textureOffset, depth);
                 }
             }