ElementDofLayout.h

// Copyright (C) 2019 Chris Richardson and Garth N. Wells
//
// This file is part of DOLFINx (https://www.fenicsproject.org)
//
// SPDX-License-Identifier:    LGPL-3.0-or-later
 
#pragma once
 
#include <array>
#include <cstdint>
#include <span>
#include <vector>
 
namespace dolfinx::mesh
{
enum class CellType : std::int8_t;
}
 
namespace dolfinx::fem
{
 
// TODO: For this class/concept to be robust, the topology of the
//       reference cell needs to be defined.
//
// TODO: Handle block dofmaps properly

class ElementDofLayout
{
public:
  ElementDofLayout(
      int block_size,
      const std::vector<std::vector<std::vector<int>>>& entity_dofs,
      const std::vector<std::vector<std::vector<int>>>& entity_closure_dofs,
      const std::vector<int>& parent_map,
      const std::vector<ElementDofLayout>& sub_layouts);

  ElementDofLayout copy() const;

  ElementDofLayout(const ElementDofLayout& dofmap) = default;

  ElementDofLayout(ElementDofLayout&& dofmap) = default;

  ~ElementDofLayout() = default;

  ElementDofLayout& operator=(const ElementDofLayout& dofmap) = default;

  ElementDofLayout& operator=(ElementDofLayout&& dofmap) = default;

  bool operator==(const ElementDofLayout& layout) const;

  int num_dofs() const;

  const std::vector<int>& entity_dofs(int dim, int entity_index) const;

  const std::vector<int>& entity_closure_dofs(int dim, int entity_index) const;

  const std::vector<std::vector<std::vector<int>>>& entity_dofs_all() const;

  const std::vector<std::vector<std::vector<int>>>&
  entity_closure_dofs_all() const;

  int num_sub_dofmaps() const;

  const ElementDofLayout& sub_layout(std::span<const int> component) const;

  std::vector<int> sub_view(std::span<const int> component) const;

  int block_size() const;

  bool is_view() const;
 
private:
  // Block size
  int _block_size;
 
  // Mapping of dofs to this ElementDofLayout's immediate parent
  std::vector<int> _parent_map;
 
  // Total number of dofs on this element dofmap
  int _num_dofs;
 
  // List of dofs per entity, ordered by dimension.
  // dof = _entity_dofs[dim][entity][i]
  std::vector<std::vector<std::vector<int>>> _entity_dofs;
 
  // List of dofs with connected entities of lower dimension
  std::vector<std::vector<std::vector<int>>> _entity_closure_dofs;
 
  // List of sub dofmaps
  // std::vector<std::shared_ptr<const ElementDofLayout>> _sub_dofmaps;
  std::vector<ElementDofLayout> _sub_dofmaps;
};
 
} // namespace dolfinx::fem