From 9695cc2771c3cae811894a278ba3a0c5ea489a48 Mon Sep 17 00:00:00 2001
From: Patrick Shriwise <pshriwise@gmail.com>
Date: Mon, 13 Jan 2020 11:34:15 -0600
Subject: [PATCH] Updating unstructured mesh constructors to take a filename
 (template). Exposing unstructured mesh addition via CAPI.

---
 include/openmc/capi.h |  1 +
 include/openmc/mesh.h | 15 +++++++++++++--
 src/mesh.cpp          | 43 ++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 56 insertions(+), 3 deletions(-)

diff --git a/include/openmc/capi.h b/include/openmc/capi.h
index a36f0e280c..64b62f3e5b 100644
--- a/include/openmc/capi.h
+++ b/include/openmc/capi.h
@@ -47,6 +47,7 @@ extern "C" {
   int openmc_get_mesh_index(int32_t id, int32_t* index);
   int openmc_get_n_batches(int* n_batches, bool get_max_batches);
   int openmc_get_nuclide_index(const char name[], int* index);
+  int openmc_add_unstructured_mesh(const char filename[], const char library[], int* id);
   int64_t openmc_get_seed();
   int openmc_get_tally_index(int32_t id, int32_t* index);
   void openmc_get_tally_next_id(int32_t* id);
diff --git a/include/openmc/mesh.h b/include/openmc/mesh.h
index 5e16c6a62e..77c01bd3aa 100644
--- a/include/openmc/mesh.h
+++ b/include/openmc/mesh.h
@@ -266,17 +266,23 @@ public:
 
 class UnstructuredMeshBase : public Mesh {
 public:
+  // constructors
+  UnstructuredMeshBase() {};
   UnstructuredMeshBase(pugi::xml_node node);
+  UnstructuredMeshBase(const std::string& filename);
+
   std::string filename_;
 };
 
 #ifdef DAGMC
 
-class UnstructuredMesh : public Mesh {
+class UnstructuredMesh : public UnstructuredMeshBase {
 
 public:
+
   UnstructuredMesh() = default;
   UnstructuredMesh(pugi::xml_node);
+  UnstructuredMesh(const std::string& filename);
   ~UnstructuredMesh() = default;
 
   void bins_crossed(const Particle& p,
@@ -447,8 +453,9 @@ class LibMesh : public UnstructuredMeshBase {
   typedef std::vector<std::pair<double, const libMesh::Elem*>> UnstructuredMeshHits;
 
 public:
-  // Constructor
+  // Constructors
   LibMesh(pugi::xml_node node);
+  LibMesh(const std::string& filename);
 
   // Methods
 
@@ -489,6 +496,10 @@ public:
 
 private:
 
+  //! Setup method for the mesh. Builds data structures,
+  //! element mapping, etc.
+  void initialize();
+
   //! Translate a bin value to an element pointer
   const libMesh::Elem* get_element_from_bin(int bin) const;
 
diff --git a/src/mesh.cpp b/src/mesh.cpp
index a3985de1d4..063c3a9047 100644
--- a/src/mesh.cpp
+++ b/src/mesh.cpp
@@ -1295,6 +1295,27 @@ openmc_extend_meshes(int32_t n, const char* type, int32_t* index_start,
   return 0;
 }
 
+//! Adds a new unstructured mesh to OpenMC
+extern "C" int openmc_add_unstrucutred_mesh(const char filename[],
+                                            const char library[],
+                                            int* mesh_id)
+{
+  if (library == "moab") {
+    model::meshes.push_back(std::move(std::make_unique<UnstructuredMesh>(filename)));
+  } else if (library == "libmesh") {
+    model::meshes.push_back(std::move(std::make_unique<LibMesh>(filename)));
+  } else {
+    set_errmsg("Mesh library " + std::string(library) + \
+               "is not supported by this build of OpenMC");
+    return OPENMC_E_INVALID_ARGUMENT;
+  }
+
+  *mesh_id = model::meshes.back()->id_;
+
+  return 0;
+}
+
+
 //! Return the index in the meshes array of a mesh with a given ID
 extern "C" int
 openmc_get_mesh_index(int32_t id, int32_t* index)
@@ -1452,6 +1473,7 @@ openmc_rectilinear_mesh_set_grid(int32_t index, const double* grid_x,
 
 #ifdef DAGMC
 
+<<<<<<< HEAD
 UnstructuredMesh::UnstructuredMesh(pugi::xml_node node) : Mesh(node)
 {
   // unstructured always assumed to be 3D
@@ -1472,7 +1494,18 @@ UnstructuredMesh::UnstructuredMesh(pugi::xml_node node) : Mesh(node)
     fatal_error("No filename supplied for unstructured mesh with ID: " +
                 std::to_string(id_));
   }
+=======
+UnstructuredMesh::UnstructuredMesh(pugi::xml_node node) : UnstructuredMeshBase(node) {
+  initialize();
+}
 
+UnstructuredMesh::UnstructuredMesh(const std::string& filename) {
+  filename_ = filename;
+  initialize();
+}
+>>>>>>> Updating unstructured mesh constructors to take a filename (template). Exposing unstructured mesh addition via CAPI.
+
+void UnstructuredMesh::initialize() {
   // create MOAB instance
   mbi_ = std::make_unique<moab::Core>();
   // load unstructured mesh file
@@ -2057,8 +2090,16 @@ UnstructuredMeshBase::UnstructuredMeshBase(pugi::xml_node node) : Mesh(node) {
 
 #ifdef LIBMESH
 LibMesh::LibMesh(pugi::xml_node node) : UnstructuredMeshBase(node) {
+  initialize();
+}
 
-  // always 3 for unstructured meshes
+LibMesh::LibMesh(const std::string& filename) {
+  filename_ = filename;
+  initialize();
+}
+
+void LibMesh::initialize() {
+    // always 3 for unstructured meshes
   n_dimension_ = 3;
 
   m_ = std::unique_ptr<libMesh::Mesh>(new libMesh::Mesh(settings::LMI->comm(), 3));