Take into account inactive cells, change name local->lgrIjk, add test…

… lgr with inac cell

CMakeLists_files.cmake

@@ -116,7 +116,7 @@ if(Boost_VERSION_STRING VERSION_GREATER 1.53)
 	  tests/cpgrid/grid_lgr_test.cpp
 	  tests/cpgrid/inactiveCell_lgr_test.cpp
 	  tests/cpgrid/lgr_cartesian_idx_test.cpp
-	  tests/cpgrid/localIJK_test.cpp
+	  tests/cpgrid/lgrIJK_test.cpp
 	  tests/cpgrid/lookUpCellCentroid_cpgrid_test.cpp
 	  tests/cpgrid/lookupdataCpGrid_test.cpp
 	  tests/cpgrid/replace_lgr1_corner_idx_by_lgr2_corner_idx_test.cpp

opm/grid/cpgrid/CpGridUtilities.cpp

@@ -26,7 +26,7 @@
 
 namespace Opm {
 
-std::vector<std::array<int,3>> localIJK(const Dune::CpGrid& grid, const std::string& lgr_name)
+std::vector<std::array<int,3>> lgrIJK(const Dune::CpGrid& grid, const std::string& lgr_name)
 {
     // Check lgr_name exists in lgr_names_
     const auto& lgr_names = grid.getLgrNameToLevel();
@@ -35,23 +35,39 @@ std::vector<std::array<int,3>> localIJK(const Dune::CpGrid& grid, const std::str
         OPM_THROW(std::runtime_error, "LGR name not found: " + lgr_name);
     }
 
-    const Opm::LevelCartesianIndexMapper<Dune::CpGrid> levelCartMapp(grid);
+    const Opm::LevelCartesianIndexMapper<Dune::CpGrid> levelCartMapper(grid);
     const auto& level = it->second;
 
-    std::vector<std::array<int, 3>> localIJK;
-    localIJK.resize(grid.levelGridView(level).size(0));
+    // Determine the logical Cartesian size of the LGR and total cells (including inactive ones)
+    const auto lgr_dim = grid.currentData()[level]->logicalCartesianSize();
+    const int lgr_cells = lgr_dim[0] * lgr_dim[1] * lgr_dim[2]; // (including inactive ones)
+    // Actual size is given by grid.levelGridView(level).size(0)
 
-    // To be improved 
-    const auto& leaf_to_lgr_idx = grid.mapLeafIndexSetToLocalCartesianIndexSets();
+    // Initialize level IJKs with inactive values
+    static constexpr std::array<int, 3> inactiveIJK = { -1, -1, -1 };
+    std::vector<std::array<int, 3>> lgrIJK(lgr_cells);
+    lgrIJK.assign(lgr_cells, inactiveIJK);  // Ensures all elements are set to inactive
+
+    // Iterate over active elements in the grid. Rewrite ijks at the specified refined level active cells.
+    //
+    // Note: to avoid go over all the leaf elements and replace this approach with the
+    // corresponding grid.levelGridView(level), a map relating level_to_lgr_idx is needed.
     for (const auto& element : Dune::elements(grid.leafGridView())) {
-        if (element.level() == level)
-        {
-            std::array<int, 3> local_ijk;
-            levelCartMapp.cartesianCoordinate( element.getLevelElem().index(), local_ijk, level);
-            localIJK[  leaf_to_lgr_idx[element.index()][1] ] = local_ijk;
+        if (element.level() != level) {
+            continue;
         }
+
+        std::array<int, 3> ijk;
+        levelCartMapper.cartesianCoordinate(element.getLevelElem().index(), ijk, level);
+        // In general, element.getLevelElem().index() != element.getLevelCartesianIdx().
+        // - element.getLevelElem().index() : integer between 0 and "total active cells - 1" on the level grid.
+        // - element.getLevelCartesianIdx() : integer between 0 and "lgr_cells - 1", representing an index of
+        //                                    the underlying Cartesian grid for the level (with/without INACTIVE cells).
+
+        const int lgr_cart_index = element.getLevelCartesianIdx();
+        lgrIJK[lgr_cart_index] = ijk;
     }
-    return localIJK;
+    return lgrIJK;
 }
 
 }

opm/grid/cpgrid/CpGridUtilities.hpp

@@ -25,14 +25,16 @@
 namespace Opm
 {
 
-/// @brief Retrieves the local IJKs of cells within a specified LGR.
+/// @brief Retrieves the local grid refinement (LGR) IJKs of cells.
 ///
 /// This method returns a vector of IJK indices corresponding to underlying Cartesian grid of the local
-/// grid refinement (LGR) specified by its name. If the specified LGR name is not found, it throws.
+/// grid refinement (LGR) specified by its name. If the specified name is not found, an exception is thrown.
+/// For inactive cells—i.e., non-existing child cells of inactive coarse cells defined by the CARFIN keyword—
+/// the corresponding IJK index is set to {-1, -1, -1}.
 ///
 /// @param lgr_name The name of the LGR whose local IJK coordinates are requested.
 /// @return std::vector<std::array<int, 3>> A list of (i, j, k)'s for each cell in the LGR.
-std::vector<std::array<int,3>> localIJK(const Dune::CpGrid& grid, const std::string& lgr_name);
+std::vector<std::array<int,3>> lgrIJK(const Dune::CpGrid& grid, const std::string& lgr_name);
 
 }