vtudata.hpp

This header file provides a data structure for storing data in the VTK (Visualization Toolkit) unstructured grid format. It includes facilities for managing point and cell data, as well as methods for writing the data to a VTK file.

Classes and Types

class VTUData

This struct provides facilities for storing point and cell data in the VTK (Visualization Toolkit) unstructured mesh format, which is commonly used for visualization purposes in scientific computing. Refer to VTK File Formats - Unstructured grid and cell-types.

Attributes:

• coord: Vector storing 3D coordinates of points.

• value: Vector storing values associated with points.

• connect: Vector storing connectivity information for cells.

• offset: Vector storing offset information for cells.

• types: Vector storing cell types.

Methods:

• WriteVTK(fname, comm=Comm::Self()): Writes the VTU data to a VTK file.

Usage guide: Using VTUData class

#ifndef _SCTL_VTUDATA_HPP_
#define _SCTL_VTUDATA_HPP_

#include <cstdint>            // for int32_t, uint8_t
#include <string>             // for string

#include "sctl/common.hpp"    // for Integer, sctl
#include "sctl/comm.hpp"      // for Comm
#include "sctl/vector.hpp"    // for Vector

namespace sctl {

/**
 * This struct provides facilities for storing point and cell data in the VTK (Visualization Toolkit) unstructured mesh
 * format, which is commonly used for visualization purposes in scientific computing.
 * Refer to <a href="https://docs.vtk.org/en/latest/design_documents/VTKFileFormats.html#unstructured-grid">VTK File Formats - Unstructured grid</a> and
 * <a href="https://raw.githubusercontent.com/Kitware/vtk-examples/gh-pages/src/Testing/Baseline/Cxx/GeometricObjects/TestLinearCellDemo.png">cell-types</a>.
 */
class VTUData {
  public:
    /**
     * Type alias for the real type used in VTK output. Fixed to `float` for
     * ParaView/VTK compatibility; higher-precision inputs are silently
     * narrowed when written into `coord`/`value`. Fine for visualization,
     * not for numerical round-trips.
     */
    typedef float VTKReal;

    // Point data
    Vector<VTKReal> coord;  //!< Vector storing 3D coordinates of points.
    Vector<VTKReal> value;  //!< Vector storing values associated with points.

    // Cell data
    Vector<int32_t> connect;  //!< Vector storing connectivity information for cells.
    Vector<int32_t> offset;   //!< Vector storing offset information for cells.
    Vector<uint8_t> types;    //!< Vector storing cell types.

    /**
     * Write the VTU data to a VTK file.
     *
     * @param fname File name for the output VTK file.
     * @param comm MPI communicator.
     */
    void WriteVTK(const std::string& fname, const Comm& comm = Comm::Self()) const;

    /**
     * Example code showing how to use the VTUData class.
     */
    static void test();
};

}

#endif // _SCTL_VTUDATA_HPP_