Added new tool: tnl-decompose-mesh

cmake/FindMETIS.cmake

+# This module will try to find METIS and define the following:
+#  METIS_FOUND - True iff METIS was found
+#  METIS_INCLUDE_DIRS - METIS include directories
+#  METIS_LIBRARIES - METIS library paths
+
+find_path(METIS_INCLUDE_DIR metis.h
+          PATHS /usr/include /usr/local/include
+          DOC "METIS include directory")
+
+find_library(METIS_LIBRARY metis
+             PATHS /usr/lib /usr/local/lib ${PROJECT_SOURCE_DIR}/metis
+             DOC "Path to METIS library")
+
+include(FindPackageHandleStandardArgs)
+# handle the QUIETLY and REQUIRED arguments and set METIS_FOUND to TRUE
+# if all listed variables are TRUE
+find_package_handle_standard_args(METIS  DEFAULT_MSG
+                                  METIS_LIBRARY METIS_INCLUDE_DIR)
+
+mark_as_advanced(METIS_INCLUDE_DIR METIS_LIBRARY)
+
+set(METIS_LIBRARIES ${METIS_LIBRARY})
+set(METIS_INCLUDE_DIRS ${METIS_INCLUDE_DIR})

src/TNL/Meshes/VTKTraits.h

@@ -157,6 +157,44 @@ inline std::string getTypeName( std::uint64_t ) { return "UInt64"; }
 inline std::string getTypeName( float ) { return "Float32"; }
 inline std::string getTypeName( double ) { return "Float64"; }
 
+/**
+ * Ghost points and ghost cells
+ *
+ * The following bit fields are consistent with the corresponding VTK enums [1], which in turn
+ * are consistent with VisIt ghost zones specification [2].
+ *
+ * - [1] https://github.com/Kitware/VTK/blob/060f626b8df0b8144ec8f10c41f936b712c0330b/Common/DataModel/vtkDataSetAttributes.h#L118-L138
+ * - [2] http://www.visitusers.org/index.php?title=Representing_ghost_data
+ */
+enum class CellGhostTypes
+: std::uint8_t
+{
+   DUPLICATECELL = 1,        // the cell is present on multiple processors
+   HIGHCONNECTIVITYCELL = 2, // the cell has more neighbors than in a regular mesh
+   LOWCONNECTIVITYCELL = 4,  // the cell has less neighbors than in a regular mesh
+   REFINEDCELL = 8,          // other cells are present that refines it.
+   EXTERIORCELL = 16,        // the cell is on the exterior of the data set
+   HIDDENCELL = 32           // the cell is needed to maintain connectivity, but the data values should be ignored.
+};
+
+enum class PointGhostTypes
+: std::uint8_t
+{
+   DUPLICATEPOINT = 1,  // the cell is present on multiple processors
+   HIDDENPOINT = 2      // the point is needed to maintain connectivity, but the data values should be ignored.
+};
+
+/**
+ * A DataArray with this name is used in the parallel VTK files to indicate ghost regions.
+ * Each value must be assigned according to the bit fields PointGhostTypes or CellGhostType.
+ *
+ * For details, see https://blog.kitware.com/ghost-and-blanking-visibility-changes/
+ */
+inline const char* ghostArrayName()
+{
+   return "vtkGhostType";
+}
+
 } // namespace VTK
 } // namespace Meshes
 } // namespace TNL

src/Tools/CMakeLists.txt

@@ -41,6 +41,23 @@ if( tinyxml2_FOUND )
    target_link_libraries(tnl-mesh-converter tinyxml2::tinyxml2)
 endif()
 
+find_package( METIS QUIET )
+if( METIS_FOUND )
+   add_executable(tnl-decompose-mesh tnl-decompose-mesh.cpp)
+   target_include_directories(tnl-decompose-mesh PUBLIC ${METIS_INCLUDE_DIRS})
+   target_link_libraries(tnl-decompose-mesh ${METIS_LIBRARIES})
+   if( ZLIB_FOUND )
+      target_compile_definitions(tnl-decompose-mesh PUBLIC "-DHAVE_ZLIB")
+      target_include_directories(tnl-decompose-mesh PUBLIC ${ZLIB_INCLUDE_DIRS})
+      target_link_libraries(tnl-decompose-mesh ${ZLIB_LIBRARIES})
+   endif()
+   if( tinyxml2_FOUND )
+      target_compile_definitions(tnl-decompose-mesh PUBLIC "-DHAVE_TINYXML2")
+      target_link_libraries(tnl-decompose-mesh tinyxml2::tinyxml2)
+   endif()
+   install( TARGETS tnl-decompose-mesh DESTINATION bin )
+endif()
+
 IF( BUILD_CUDA )
    CUDA_ADD_EXECUTABLE( tnl-cuda-arch tnl-cuda-arch.cu )
    INSTALL( TARGETS tnl-cuda-arch