Fix equipped weapons rendering wrong for one frame

src/Items/Items.cs

@@ -57,5 +57,8 @@ public class Items : Node2D, IItems
         node.SetProcessInput(value);
         node.SetProcessUnhandledInput(value);
         node.Visible = value;
+        // Call _Process when an item is equipped so it
+        // has a chance to update before it gets drawn.
+        if (value) node._Process(0);
     }
 }

src/Items/Weapon.cs

@@ -47,8 +47,6 @@ public class Weapon : Sprite
 
     public override void _Process(float delta)
     {
-        // FIXME: Need to run _Process after switching to a weapon.
-
         _currentSpreadInc = Mathf.Max(0, _currentSpreadInc - Mathf.Deg2Rad(SpreadRegen) * delta);
         _currentRecoil    = Mathf.Max(0, _currentRecoil    - Mathf.Deg2Rad(RecoilRegen) * delta);