Unit test for the distance to next boundary method

Author: JoffreyDorville

include/openmc/mesh.h

@@ -181,7 +181,7 @@ class Mesh {
   //! \param[in] r Position of the particle
   //! \param[in] u Particle direction
   //! \return Distance to the next boundary
-  virtual double distance_to_next_boundary(Position r, Position u) const = 0;
+  virtual double distance_to_next_boundary(Position r, Direction u) const = 0;
 
   //! Get bin at a given position in space
   //
@@ -312,7 +312,7 @@ class StructuredMesh : public Mesh {
   void surface_bins_crossed(Position r0, Position r1, const Direction& u,
     vector<int>& bins) const override;
 
-  double distance_to_next_boundary(Position r, Position u) const override;
+  double distance_to_next_boundary(Position r, Direction u) const override;
 
   //! Determine which cell or surface bins were crossed by a particle
   //
@@ -696,7 +696,7 @@ class UnstructuredMesh : public Mesh {
   UnstructuredMesh(pugi::xml_node node);
   UnstructuredMesh(hid_t group);
 
-  double distance_to_next_boundary(Position r, Position u) const override;
+  double distance_to_next_boundary(Position r, Direction u) const override;
 
   static const std::string mesh_type;
   virtual std::string get_mesh_type() const override;

src/mesh.cpp

@@ -720,7 +720,7 @@ UnstructuredMesh::UnstructuredMesh(hid_t group) : Mesh(group)
   }
 }
 
-double UnstructuredMesh::distance_to_next_boundary(Position r, Position u) const
+double UnstructuredMesh::distance_to_next_boundary(Position r, Direction u) const
 {
   fatal_error("Not implemented");
   return -1.0;
@@ -1181,12 +1181,12 @@ void StructuredMesh::surface_bins_crossed(
   raytrace_mesh(r0, r1, u, SurfaceAggregator(this, bins));
 }
 
-double StructuredMesh::distance_to_next_boundary(Position r, Position u) const
+double StructuredMesh::distance_to_next_boundary(Position r, Direction u) const
 {
   Position global_r = r;
   Position local_r = local_coords(r);
 
-  double distance = INFTY;
+  double distance = 0.0;
   const int n = n_dimension_;
   bool in_mesh;
 

tests/cpp_unit_tests/test_mesh.cpp

@@ -255,3 +255,39 @@ TEST_CASE("Test multiple meshes HDF5 roundtrip - spherical")
   REQUIRE(regular_mesh_hdf5->lower_left() == regular_mesh_xml->lower_left());
   REQUIRE(regular_mesh_hdf5->upper_right() == regular_mesh_xml->upper_right());
 }
+
+TEST_CASE("Test distance_to_next_boundary() method for regular mesh")
+{
+  // The XML data as a string
+  std::string xml_string = R"(
+        <mesh id="1">
+            <dimension>2 2 2</dimension>
+            <lower_left>-1 -1 -1</lower_left>
+            <upper_right>1 1 1</upper_right>
+      </mesh>
+    )";
+
+  // Create the mesh from a file
+  pugi::xml_document doc;
+  pugi::xml_parse_result result = doc.load_string(xml_string.c_str());
+  pugi::xml_node root = doc.child("mesh");
+  auto mesh = RegularMesh(root);
+
+  Position r;
+  Position u;
+
+  // Test inside the mesh
+  r = Position(0.0, 0.0, 0.0);
+  u = Position(1.0, 0.0, 0.0);
+  REQUIRE(mesh.distance_to_next_boundary(r, u) == 1.0);
+
+  // Test outside the mesh, going toward the mesh
+  r = Position(-1.5, 0.0, 0.0);
+  u = Position(1.0, 0.0, 0.0);
+  REQUIRE(mesh.distance_to_next_boundary(r, u) == 0.5);
+
+  // Test outside the mesh, not going toward the mesh
+  r = Position(-2.0, 0.0, 0.0);
+  u = Position(-1.0, 0.0, 0.0);
+  REQUIRE(mesh.distance_to_next_boundary(r, u) == INFTY);
+}