Optimise storage a quadrillion times (#37638)

* Optimise storage a quadrillion times

* How sweaty can we get

* Add fast angle checks

* Fix chunk indices

* Optimise the refresh method

Helps on client a lot as the clientside is suboptimal atm.

* Better name

* wawawewa

* Add single-angle path

* Okay FINE rider

Content.Shared/Item/SharedItemSystem.cs

@@ -5,6 +5,7 @@ using Content.Shared.Examine;
 using Content.Shared.Item.ItemToggle.Components;
 using Content.Shared.Storage;
 using JetBrains.Annotations;
+using Robust.Shared.Collections;
 using Robust.Shared.Containers;
 using Robust.Shared.GameStates;
 using Robust.Shared.Prototypes;
@@ -206,15 +207,21 @@ public abstract class SharedItemSystem : EntitySystem
     public IReadOnlyList<Box2i> GetAdjustedItemShape(Entity<ItemComponent?> entity, Angle rotation, Vector2i position)
     {
         if (!Resolve(entity, ref entity.Comp))
-            return new Box2i[] { };
+            return [];
 
+        var adjustedShapes = new List<Box2i>();
+        GetAdjustedItemShape(adjustedShapes, entity, rotation, position);
+        return adjustedShapes;
+    }
+
+    public void GetAdjustedItemShape(List<Box2i> adjustedShapes, Entity<ItemComponent?> entity, Angle rotation, Vector2i position)
+    {
         var shapes = GetItemShape(entity);
         var boundingShape = shapes.GetBoundingBox();
         var boundingCenter = ((Box2) boundingShape).Center;
         var matty = Matrix3Helpers.CreateTransform(boundingCenter, rotation);
         var drift = boundingShape.BottomLeft - matty.TransformBox(boundingShape).BottomLeft;
 
-        var adjustedShapes = new List<Box2i>();
         foreach (var shape in shapes)
         {
             var transformed = matty.TransformBox(shape).Translated(drift);
@@ -223,8 +230,6 @@ public abstract class SharedItemSystem : EntitySystem
 
             adjustedShapes.Add(translated);
         }
-
-        return adjustedShapes;
     }
 
     /// <summary>