Add new constructor for MOAB Unstructured Mesh class, taking a pointer to an external MOAB instance as an argument

include/openmc/mesh.h

@@ -366,6 +366,7 @@ public:
   MOABMesh() = default;
   MOABMesh(pugi::xml_node);
   MOABMesh(const std::string& filename);
+  MOABMesh(std::shared_ptr<moab::Interface> external_mbi);
 
   // Overridden Methods
 

src/mesh.cpp

@@ -160,7 +160,6 @@ StructuredMesh::bin_label(int bin) const {
 //==============================================================================
 
 UnstructuredMesh::UnstructuredMesh(pugi::xml_node node) : Mesh(node) {
-  n_dimension_ = 3;
 
   // check the mesh type
   if (check_for_node(node, "type")) {
@@ -1582,6 +1581,12 @@ MOABMesh::MOABMesh(const std::string& filename) {
   initialize();
 }
 
+MOABMesh::MOABMesh(std::shared_ptr<moab::Interface> external_mbi) {
+  mbi_ = external_mbi;
+  filename_ = "unknown (external file)";
+  initialize();
+}
+
 void MOABMesh::initialize() {
 
   // Create the MOAB interface and load data from file
@@ -1590,6 +1595,9 @@ void MOABMesh::initialize() {
   // Initialise MOAB error code
   moab::ErrorCode rval = moab::MB_SUCCESS;
 
+  // Set the dimension
+  n_dimension_ = 3;
+
   // set member range of tetrahedral entities
   rval = mbi_->get_entities_by_dimension(0, n_dimension_, ehs_);
   if (rval != moab::MB_SUCCESS) {
@@ -1621,6 +1629,7 @@ void MOABMesh::initialize() {
 void
 MOABMesh::create_interface()
 {
+  // Do not create a MOAB instance if one is already in memory
   if(mbi_ == nullptr){
     // create MOAB instance
     mbi_ = std::make_shared<moab::Core>();

tests/regression_tests/external_moab/main.cpp

@@ -9,6 +9,15 @@ int main(int argc, char * argv[]){
   using namespace openmc;
   int openmc_err;
 
+  // Initialise OpenMC
+  openmc_err = openmc_init(argc, argv, nullptr);
+  if (openmc_err == -1) {
+    // This happens for the -h and -v flags
+    return EXIT_SUCCESS;
+  } else if (openmc_err) {
+    fatal_error(openmc_err_msg);
+  }
+
   // Create MOAB interface
   std::shared_ptr<moab::Interface> moabPtrLocal =
     std::make_shared<moab::Core>();
@@ -20,23 +29,29 @@ int main(int argc, char * argv[]){
     fatal_error("Failed to load the unstructured mesh file: " + filename);
   }
   else{
-    std::cout<<"Loaded external mesh from file "<<filename<<std::endl;
+    std::cout<<"Loaded external MOAB mesh from file "<<filename<<std::endl;
   }
 
-  // Initialise OpenMC
-  openmc_err = openmc_init(argc, argv, nullptr);
+  // Add a new unstructured mesh to openmc using new constructor
+  model::meshes.push_back(std::make_unique<MOABMesh>(moabPtrLocal));
 
-  if (openmc_err == -1) {
-    // This happens for the -h and -v flags
-    return EXIT_SUCCESS;
-  } else if (openmc_err) {
-    fatal_error(openmc_err_msg);
+  // Check we now have 2 copies of the shared ptr
+  if(moabPtrLocal.use_count()!=2){
+     fatal_error("Incorrect number of MOAB shared pointers");
   }
 
-  // Create a new unstructured mesh tally using new constructor
+  // Set mesh ID (-1 signifies auto-assign)
+  model::meshes.back()->set_id(-1);
+  int mesh_id = model::meshes.back()->id_;
+
+  // Check we now have 2 meshes and id was correctly set
+  if(model::meshes.size()!=2)
+     fatal_error("Wrong number of meshes.");
+   else if(mesh_id!=2)
+     fatal_error("Mesh ID is incorrect");
+
+  // Add a new mesh filter tally
 
-  // Add unstructured mesh tally to openmc
-  
   // Run OpenMC
   openmc_err = openmc_run();
   if (openmc_err) fatal_error(openmc_err_msg);

tests/regression_tests/external_moab/test.py

@@ -39,7 +39,7 @@ def cpp_driver(request):
             target_link_libraries(main OpenMC::libopenmc)
             set_target_properties(main PROPERTIES CXX_STANDARD 14 CXX_STANDARD_REQUIRED YES CXX_EXTENSIONS NO)
             set(CMAKE_CXX_FLAGS "-pedantic-errors")
-
+            add_compile_definitions(DAGMC=1)
             """.format(openmc_dir)))
 
     # Create temporary build directory and change to there
@@ -93,7 +93,7 @@ class ExternalMoabTest(PyAPITestHarness):
 
     def _test_output_created(self):
         pass
-    
+
     # Directly compare results of unstructured  mesh with internal and external moab
     def _compare_results(self):