Implemented NDMetaGrid for easier usage of the VTIWriter without a proper mesh data structure

/***************************************************************************

                          NDMetaGrid.h  -  description

                             -------------------

    begin                : Dec 09, 2021

    copyright            : (C) 2021 by Tomas Oberhuber et al.

    email                : tomas.oberhuber@fjfi.cvut.cz

 ***************************************************************************/

/* See Copyright Notice in tnl/Copyright */

// Implemented by: Jakub Klinkovský

#pragma once

#include <TNL/Containers/StaticVector.h>

namespace TNL {

namespace Meshes {

/**

 * \brief Minimal class usable as \e Mesh in the \ref VTIWriter.

 *

 * It does not have a \e Device template argument, because it does not describe

 * a data structure - it contains only the information describing the domain of

 * the grid (i.e., the metadata of the \e ImageData tag in the VTI file

 * format). Note that VTK supports only 1, 2, or 3-dimensional grids.

 */

template< int Dimension, typename Real, typename Index >

class NDMetaGrid

{

public:

   using RealType = Real;

   using GlobalIndexType = Index;

   using PointType = Containers::StaticVector< Dimension, Real >;

   using CoordinatesType = Containers::StaticVector< Dimension, Index >;

   //! \brief Returns the spatial dimension of the grid.

   static constexpr int getMeshDimension()

   {

      return Dimension;

   }

   //! \brief Sets the grid dimensions/size.

   void setDimensions( const CoordinatesType& dimensions )

   {

      this->dimensions = dimensions;

   }

   //! \brief Returns the grid dimensions/size.

   const CoordinatesType& getDimensions() const

   {

      return dimensions;

   }

   //! \brief Sets the origin of the grid (coordinates of the left bottom front

   //! corner).

   void setOrigin( const PointType& origin )

   {

      this->origin = origin;

   }

   //! \brief Returns the origin of the grid (coordinates of the left bottom

   //! front corner).

   const PointType& getOrigin() const

   {

      return origin;

   }

   //! \brief Sets the domain of the grid (i.e., the origin and

   //! proportions/length). Note that space steps are computed using the

   //! current grid dimensions.

   void setDomain( const PointType& origin,

                   const PointType& proportions )

   {

      this->origin = origin;

      this->spaceSteps = proportions / dimensions;

   }

   //! \brief Sets the space steps of the grid, i.e. the parameters usually

   //! denoted as \e hx, \e hy, \e hz.

   void setSpaceSteps( const PointType& spaceSteps )

   {

      this->spaceSteps = spaceSteps;

   }

   //! \brief Returns the space steps of the grid.

   const PointType& getSpaceSteps() const

   {

      return spaceSteps;

   }

protected:

   CoordinatesType dimensions;

   PointType origin;

   PointType spaceSteps;

};

} // namespace Meshes

} // namespace TNL