Refactor RTree.

Runtime/external/RTree.cs

         }
     }
 
-    public partial class RTree<T>
+    public class RTree<T> where T : ISpatialData
     {
         public class RTreeNode : ISpatialData
         {
                 _Rect = GetEnclosingRect(children);
             }
         }
-    }
-
-    public partial class RTree<T>
-    {
         #region Search
 
         private List<T> DoSearch(in Rect boundingBox)
                 rTreeNode.children.Sort(CompareMinX);
         }
 
-        private double GetPotentialSplitMargins(List<ISpatialData> children)
+        private float GetPotentialSplitMargins(List<ISpatialData> children)
-        private double GetPotentialEnclosingMargins(List<ISpatialData> children)
+        private float GetPotentialEnclosingMargins(List<ISpatialData> children)
         {
             var rect = Rect.zero;
             var i = 0;
         }
 
         #endregion
-    }
-
-    public partial class RTree<T> where T : ISpatialData
-    {
-        private const double DefaultFillFactor = 0.4;
+        private const float DefaultFillFactor = 0.4f;
 
         private readonly EqualityComparer<T> comparer;
         private readonly int maxEntries;