From a69baeaed55d8a738e25907ebd1380ee9a0e5333 Mon Sep 17 00:00:00 2001
From: Sterling Harper <smharper@mit.edu>
Date: Fri, 2 Mar 2018 02:12:31 -0500
Subject: [PATCH] Populate C++ Universe vector

---
 src/cell.cpp    | 21 +++++++++++++++++++++
 src/cell.h      | 10 +++++++---
 src/constants.h | 13 +++++++++++++
 src/surface.h   | 10 ++--------
 4 files changed, 43 insertions(+), 11 deletions(-)
 create mode 100644 src/constants.h

diff --git a/src/cell.cpp b/src/cell.cpp
index fe04f8c69..136f36e06 100644
--- a/src/cell.cpp
+++ b/src/cell.cpp
@@ -5,6 +5,7 @@
 #include <sstream>
 #include <string>
 
+#include "constants.h"
 #include "error.h"
 #include "hdf5_interface.h"
 #include "surface.h"
@@ -204,6 +205,12 @@ Cell::Cell(pugi::xml_node cell_node)
     universe = 0;
   }
 
+  if (check_for_node(cell_node, "fill")) {
+    fill = stoi(get_node_value(cell_node, "fill"));
+  } else {
+    fill = C_NONE;
+  }
+
   std::string region_spec {""};
   if (check_for_node(cell_node, "region")) {
     region_spec = get_node_value(cell_node, "region");
@@ -405,6 +412,20 @@ read_cells(pugi::xml_node *node)
   for (pugi::xml_node cell_node: node->children("cell")) {
     cells_c.push_back(new Cell(cell_node));
   }
+
+  // Populate the Universe vector and dictionary.
+  for (Cell *c : cells_c) {
+    int32_t uid = c->universe;
+    auto it = universe_dict.find(uid);
+    if (it == universe_dict.end()) {
+      universes_c.push_back(new Universe());
+      universes_c.back()->id = uid;
+      universes_c.back()->cells.push_back(c);
+      universe_dict[uid] = universes_c.size() - 1;
+    } else {
+      universes_c[it->second]->cells.push_back(c);
+    }
+  }
 }
 
 //==============================================================================
diff --git a/src/cell.h b/src/cell.h
index de5e25aa7..8b540be35 100644
--- a/src/cell.h
+++ b/src/cell.h
@@ -21,8 +21,11 @@ extern "C" {int32_t n_cells {0};}
 
 class Cell;
 std::vector<Cell*> cells_c;
+std::map<int32_t, int32_t> cell_dict;
 
-std::map<int, int> cell_dict;
+class Universe;
+std::vector<Universe*> universes_c;
+std::map<int32_t, int32_t> universe_dict;
 
 //==============================================================================
 //! A geometry primitive that fills all space and contains cells.
@@ -30,10 +33,10 @@ std::map<int, int> cell_dict;
 
 class Universe
 {
-  public:
+public:
   int32_t id;                  //! Unique ID
   int32_t type;
-  std::vector<int32_t> cells;  //! Cells within this universe
+  std::vector<Cell*> cells;    //! Cells within this universe
   double x0, y0, z0;           //! Translation coordinates.
 };
 
@@ -47,6 +50,7 @@ public:
   int32_t id;                //!< Unique ID
   std::string name{""};      //!< User-defined name
   int32_t universe;          //!< Universe # this cell is in
+  int32_t fill;              //!< Universe # filling this cell
 
   //! Definition of spatial region as Boolean expression of half-spaces
   std::vector<std::int32_t> region;
diff --git a/src/constants.h b/src/constants.h
new file mode 100644
index 000000000..b725809fe
--- /dev/null
+++ b/src/constants.h
@@ -0,0 +1,13 @@
+#ifndef CONSTANTS_H
+#define CONSTANTS_H
+
+
+namespace openmc{
+
+extern "C" double FP_COINCIDENT;
+constexpr double INFTY{std::numeric_limits<double>::max()};
+constexpr int C_NONE {-1};
+
+} // namespace openmc
+
+#endif // CONSTANTS_H
diff --git a/src/surface.h b/src/surface.h
index 046610daa..2be21c063 100644
--- a/src/surface.h
+++ b/src/surface.h
@@ -8,6 +8,8 @@
 #include "hdf5.h"
 #include "pugixml/pugixml.hpp"
 
+#include "constants.h"
+
 
 namespace openmc {
 
@@ -20,14 +22,6 @@ extern "C" const int BC_VACUUM;
 extern "C" const int BC_REFLECT;
 extern "C" const int BC_PERIODIC;
 
-//==============================================================================
-// Constants that should eventually be moved out of this file
-//==============================================================================
-
-extern "C" double FP_COINCIDENT;
-constexpr double INFTY{std::numeric_limits<double>::max()};
-constexpr int C_NONE {-1};
-
 //==============================================================================
 // Global variables
 //==============================================================================