Initial support for conversion from 4C to deal.II

Author: sebproell

src/CMakeLists.txt

@@ -22,6 +22,9 @@ add_subdirectory(contact_constitutivelaw)
 add_subdirectory(core)
 add_subdirectory(coupling)
 add_subdirectory(cut)
+if(FOUR_C_WITH_DEAL_II)
+  add_subdirectory(deal_ii)
+endif()
 add_subdirectory(ehl)
 add_subdirectory(elch)
 add_subdirectory(fbi)

src/deal_ii/CMakeLists.txt

@@ -0,0 +1,11 @@
+# This file is part of 4C multiphysics licensed under the
+# GNU Lesser General Public License v3.0 or later.
+#
+# See the LICENSE.md file in the top-level for license information.
+#
+# SPDX-License-Identifier: LGPL-3.0-or-later
+
+four_c_auto_define_module(NO_CYCLES)
+
+# deal.II support is a pure extension of the core module and may not depend on any other module
+four_c_add_dependency(${AUTO_DEFINED_MODULE_NAME} core)

src/deal_ii/src/4C_deal_ii_context.hpp

@@ -0,0 +1,42 @@
+// This file is part of 4C multiphysics licensed under the
+// GNU Lesser General Public License v3.0 or later.
+//
+// See the LICENSE.md file in the top-level for license information.
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+#ifndef FOUR_C_DEAL_II_CONTEXT_HPP
+#define FOUR_C_DEAL_II_CONTEXT_HPP
+
+#include "4C_config.hpp"
+
+#include <memory>
+
+FOUR_C_NAMESPACE_OPEN
+
+namespace DealiiWrappers
+{
+
+  // forward declaration
+  namespace Internal
+  {
+    template <int dim, int spacedim>
+    struct ContextImplementation;
+  }
+
+  /**
+   * This class holds data which helps other classes and functions in this namespace to understand
+   * the link between 4C and deal.II data structures. There is no documented and supported
+   * functionality for this class. In fact, you should not try to do anything with the internals of
+   * this class.
+   */
+  template <int dim, int spacedim = dim>
+  struct Context
+  {
+    std::shared_ptr<Internal::ContextImplementation<dim, spacedim>> pimpl_;
+  };
+}  // namespace DealiiWrappers
+
+FOUR_C_NAMESPACE_CLOSE
+
+#endif

src/deal_ii/src/4C_deal_ii_context_implementation.hpp

@@ -0,0 +1,42 @@
+// This file is part of 4C multiphysics licensed under the
+// GNU Lesser General Public License v3.0 or later.
+//
+// See the LICENSE.md file in the top-level for license information.
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+#ifndef FOUR_C_DEAL_II_CONTEXT_IMPLEMENTATION_HPP
+#define FOUR_C_DEAL_II_CONTEXT_IMPLEMENTATION_HPP
+
+#include "4C_config.hpp"
+
+#include "4C_deal_ii_context.hpp"
+#include "4C_fem_discretization.hpp"
+
+#include <deal.II/hp/fe_collection.h>
+#include <deal.II/hp/mapping_collection.h>
+
+#include <unordered_map>
+#include <vector>
+
+FOUR_C_NAMESPACE_OPEN
+
+namespace DealiiWrappers::Internal
+{
+  template <int dim, int spacedim = dim>
+  struct ContextImplementation
+  {
+    //! Store the local mapping between deal.II cells and 4C elements
+    std::unordered_map<int, int> cell_index_to_element_lid;
+
+    //! All dealii::FiniteElement objects that are required for the original 4C discretization.
+    dealii::hp::FECollection<dim, spacedim> finite_elements;
+
+    //! The names of the FiniteElements in #finite_elements.
+    std::vector<std::string> finite_element_names;
+  };
+}  // namespace DealiiWrappers::Internal
+
+FOUR_C_NAMESPACE_CLOSE
+
+#endif

src/deal_ii/src/4C_deal_ii_dofs.cpp

@@ -0,0 +1,64 @@
+// This file is part of 4C multiphysics licensed under the
+// GNU Lesser General Public License v3.0 or later.
+//
+// See the LICENSE.md file in the top-level for license information.
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+#include "4C_deal_ii_dofs.hpp"
+
+#include "4C_deal_ii_context_implementation.hpp"
+#include "4C_deal_ii_element_conversion.hpp"
+#include "4C_fem_discretization.hpp"
+
+#include <deal.II/fe/fe_system.h>
+#include <deal.II/fe/fe_tools.h>
+#include <deal.II/fe/mapping_q.h>
+#include <deal.II/hp/mapping_collection.h>
+
+FOUR_C_NAMESPACE_OPEN
+
+namespace DealiiWrappers
+{
+
+  template <int dim, int spacedim>
+  void assign_fes_and_dofs(dealii::DoFHandler<dim, spacedim>& dof_handler,
+      const Core::FE::Discretization& discretization, Context<dim, spacedim>& context)
+  {
+    const auto& fe_collection = context.pimpl_->finite_elements;
+    const auto& fe_names = context.pimpl_->finite_element_names;
+
+    // Loop all cells again and set the correct fe index within the collection
+    for (const auto& cell : dof_handler.active_cell_iterators())
+    {
+      if (!cell->is_locally_owned()) continue;
+
+      const auto four_c_element_lid = context.pimpl_->cell_index_to_element_lid[cell->index()];
+      const auto* four_c_element = discretization.l_row_element(four_c_element_lid);
+
+      auto iter = std::find(fe_names.begin(), fe_names.end(),
+          ElementConversion::dealii_fe_name(four_c_element->shape()));
+      FOUR_C_ASSERT(iter != fe_names.end(),
+          "The finite element name '{}' is not in the list of finite element names.",
+          ElementConversion::dealii_fe_name(four_c_element->shape()));
+
+      const unsigned index = std::distance(fe_names.begin(), iter);
+      cell->set_active_fe_index(index);
+    }
+
+    // Now distribute the dofs, which will use the previously set index
+    dof_handler.distribute_dofs(fe_collection);
+
+    // Depending on the element types we need to construct an appropriate mapping collection
+    FOUR_C_ASSERT(fe_collection.size() == 1,
+        "The current implementation only supports a single finite element type per "
+        "discretization.");
+  }
+
+
+  // explicit instantiation
+  template void assign_fes_and_dofs(dealii::DoFHandler<3, 3>&,
+      const Core::FE::Discretization& discretization, Context<3, 3>& context);
+}  // namespace DealiiWrappers
+
+FOUR_C_NAMESPACE_CLOSE

src/deal_ii/src/4C_deal_ii_dofs.hpp

@@ -0,0 +1,42 @@
+// This file is part of 4C multiphysics licensed under the
+// GNU Lesser General Public License v3.0 or later.
+//
+// See the LICENSE.md file in the top-level for license information.
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+#ifndef FOUR_C_DEAL_II_DOFS_HPP
+#define FOUR_C_DEAL_II_DOFS_HPP
+
+#include "4C_config.hpp"
+
+#include "4C_deal_ii_context.hpp"
+
+#include <deal.II/dofs/dof_handler.h>
+
+FOUR_C_NAMESPACE_OPEN
+
+namespace Core::FE
+{
+  class Discretization;
+}
+
+namespace DealiiWrappers
+{
+  /**
+   * @brief Assigns a finite element and degrees of freedom to the given @p dof_handler.
+   *
+   * The information about the finite element and degrees of freedom is taken from the
+   * @p context object, which was created during create_triangulation(). After calling this
+   * function, the @p dof_handler will be set up to mimic the finite element space inside
+   * the @p discretization object.
+   */
+  template <int dim, int spacedim>
+  void assign_fes_and_dofs(dealii::DoFHandler<dim, spacedim>& dof_handler,
+      const Core::FE::Discretization& discretization, Context<dim, spacedim>& context);
+
+}  // namespace DealiiWrappers
+
+FOUR_C_NAMESPACE_CLOSE
+
+#endif