Fixed bug where tighten would not be called on insert; ensured that n…

…on-leaf root node always has >= 2 entries

src/com/newbrightidea/util/RTree.java

@@ -165,12 +165,8 @@ public boolean delete(float[] coords, float[] dimensions, T entry)
     assert (coords.length == numDims);
     assert (dimensions.length == numDims);
     Node l = findLeaf(root, coords, dimensions, entry);
-    if (l == null )
-    {
-      System.out.println( "WTF?" );
-      findLeaf(root, coords, dimensions, entry);
-    }
-    assert (l.leaf);
+    assert (l != null) : "Could not find leaf for entry to delete";
+    assert (l.leaf) : "Entry is not found at leaf?!?";
     ListIterator<Node> li = l.children.listIterator();
     T removed = null;
     while (li.hasNext())
@@ -264,6 +260,11 @@ else if (!n.leaf && (n.children.size() < minEntries))
     {
       root = buildRoot(true);
     }
+    else if ( (root.children.size() == 1) && (!root.leaf) )
+    {
+      root = root.children.get(0);
+      root.parent = null;
+    }
     else
     {
       tighten(root);
@@ -277,6 +278,15 @@ else if (!n.leaf && (n.children.size() < minEntries))
     size -= q.size();
   }
 
+  /**
+   * Empties the RTree
+   */
+  public void clear()
+  {
+    root = buildRoot(true);
+    // let the GC take care of the rest.
+  }
+
   /**
    * Inserts the given entry into the RTree, associated with the given
    * rectangle.
@@ -309,15 +319,6 @@ public void insert(float[] coords, float[] dimensions, T entry)
     }
   }
 
-  /**
-   * Empties the RTree
-   */
-  public void clear()
-  {
-    root = buildRoot(true);
-    // let the GC take care of the rest.
-  }
-
   private void adjustTree(Node n, Node nn)
   {
     if (n == root)
@@ -344,7 +345,7 @@ private void adjustTree(Node n, Node nn)
         adjustTree(splits[0], splits[1]);
       }
     }
-    else if (n.parent != null)
+    if (n.parent != null)
     {
       adjustTree(n.parent, null);
     }
@@ -372,13 +373,17 @@ private Node[] splitNode(Node n)
       {
         nn[1].children.addAll(cc);
         cc.clear();
+        tighten(nn[0]); // Not sure this is required.
+        tighten(nn[1]);
         return nn;
       }
       else if ((nn[1].children.size() >= minEntries)
           && (nn[0].children.size() + cc.size() == minEntries))
       {
         nn[0].children.addAll(cc);
         cc.clear();
+        tighten(nn[0]); // Not sure this is required.
+        tighten(nn[1]);
         return nn;
       }
       Node c = cc.pop();

test/com/newbrightidea/util/TestRTree.java

@@ -262,23 +262,25 @@ class DataObject {
       }
     }
 
-    RTree<Integer> tree = new RTree<Integer>(4, 2, 3);
-    List<DataObject> rects = new ArrayList<DataObject>();
+    for ( int j = 0; j < 500; j++ )
+    {
+      RTree<Integer> tree = new RTree<Integer>(10, 2, 3);
+      List<DataObject> rects = new ArrayList<DataObject>();
 
-    for (int i = 0; i < 15; i++) {
-      rects.add(new DataObject(
-          new float[]{i, i * 2, i * 3},
-          new float[]{0, 0, 0},
-          i));
-      DataObject dataObject = rects.get(i);
-      tree.insert(dataObject.val, dataObject.dim, dataObject.id);
-    }
+      for (int i = 0; i < 100; i++) {
+        rects.add(new DataObject(
+            new float[]{i, i * 2, i * 3},
+            new float[]{0, 0, 0},
+            i));
+        DataObject dataObject = rects.get(i);
+        tree.insert(dataObject.val, dataObject.dim, dataObject.id);
+      }
 
-    for (int i = 0; i < 15; i++) {
-      DataObject dataObject = rects.get(i);
-      System.out.print(" " + i);
-      boolean deleted = tree.delete(dataObject.val, dataObject.dim, dataObject.id);
-      assert deleted;
+      for (int i = 0; i < 100; i++) {
+        DataObject dataObject = rects.get(i);
+        boolean deleted = tree.delete(dataObject.val, dataObject.dim, dataObject.id);
+        assert deleted;
+      }
     }
   }