From 1b06786e63e91cde4d229ea86f442516a59a486b Mon Sep 17 00:00:00 2001
From: Guilhem Lavaux <guilhem.lavaux@laposte.net>
Date: Mon, 4 Mar 2013 22:48:13 -0500
Subject: [PATCH] Started work to support periodic boundaries in KDTree

---
 src/mykdtree.hpp           |  2 ++
 src/mykdtree.tcc           | 17 +++++++++++++++--
 src/replicateGenerator.hpp | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 src/replicateGenerator.hpp

diff --git a/src/mykdtree.hpp b/src/mykdtree.hpp
index 1a691c6..9d2c63c 100644
--- a/src/mykdtree.hpp
+++ b/src/mykdtree.hpp
@@ -184,6 +184,8 @@ namespace CosmoTool {
     Cell **sortingHelper;
     Cell *base_cell;
 
+    bool periodic;
+
     Node *buildTree(Cell **cell0,
 		    uint32_t NumCells,
 		    uint32_t depth,
diff --git a/src/mykdtree.tcc b/src/mykdtree.tcc
index a5e3abb..27ea18b 100644
--- a/src/mykdtree.tcc
+++ b/src/mykdtree.tcc
@@ -31,7 +31,8 @@ namespace CosmoTool {
   template<int N, typename ValType, typename CType, typename CellSplitter>
   KDTree<N,ValType,CType,CellSplitter>::KDTree(Cell *cells, uint32_t Ncells)
   {
-    
+    periodic = false; 
+
     base_cell = cells;
     numNodes = Ncells;
     nodes = new Node[numNodes];
@@ -365,7 +366,19 @@ namespace CosmoTool {
    CoordType R2 = INFINITY;
    Cell *best = 0;
 
-   recursiveNearest(root, 0, x, R2, best);   
+   recursiveNearest(root, 0, x, R2, best);
+   if (periodic)
+     {
+#if 0
+       ReplicateGenerator<N> replicate(x);
+
+       do
+         {
+           recursiveNearest(root, 0, replicate.getPosition(), R2, best); 
+         }
+       while (replicate.next());
+#endif
+     }
    
    return best;
  }
diff --git a/src/replicateGenerator.hpp b/src/replicateGenerator.hpp
new file mode 100644
index 0000000..270640f
--- /dev/null
+++ b/src/replicateGenerator.hpp
@@ -0,0 +1,37 @@
+#ifndef __REPLICATE_GENERATOR_HPP
+#define __REPLICATE_GENERATOR_HPP
+
+namespace CosmoTool
+{
+
+  template<typename Coord, int N>
+  class ReplicateGenerator
+  {
+  public:
+    ReplicateGenerator(const Coord x[N])
+    {
+      face = 0;
+    }
+
+    bool next()
+    {
+      if (face == (2*N))
+        return false;
+
+      face++;
+      
+    }
+
+    Coord getPosition()
+    {
+      return x_shifted;
+    }
+
+  private:
+    Coord x_shifted[N];
+    int face;
+  };
+
+};
+
+#endif