MeshData.hpp

#pragma once
 
#include <Eigen/Core>
#include <cstdint>
#include <map>
#include <nlohmann/json.hpp>
#include <string>
#include <variant>
#include <vector>
 
namespace wmtk {
 
// Values agree with VTK's linear cell types. Connectivity always indexes rows of V.
enum class CellType {
    Point = 1,
    Edge = 3,
    Triangle = 5,
    Quad = 9,
    Tetrahedron = 10,
    Prism = 13,
    Pyramid = 14
};
template <typename T>
using DataMatrix = Eigen::Matrix<T, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor>;
using AttributeValues = std::variant<DataMatrix<double>, DataMatrix<int64_t>, DataMatrix<uint8_t>>;
 
struct MeshAttribute
{
    AttributeValues values = DataMatrix<double>();
    // Optional labels for columns, e.g. the names of overlapping material tags.
    std::vector<std::string> labels;
 
    Eigen::Index rows() const;
    Eigen::Index cols() const;
    DataMatrix<double> doubles() const;
    DataMatrix<int64_t> integers() const;
};
using MeshAttributes = std::map<std::string, MeshAttribute>;
 
struct CellData
{
    DataMatrix<int64_t> connectivity;
    MeshAttributes attributes;
};
 
// An owning interchange value, independent of the mutable topology/attribute machinery.
struct MeshData
{
    DataMatrix<double> V{0, 3};
    MeshAttributes vertex_attributes;
    std::map<CellType, CellData> cells;
 
    void validate() const;
    const CellData& cell(CellType type) const;
};
 
using MeshMap = std::map<std::string, MeshData>;
using ComponentResult = std::pair<MeshMap, nlohmann::json>;
 
int cell_size(CellType type);
int cell_dimension(CellType type);
 
} // namespace wmtk