sandbox/acastillo/output_fields/vtu/output_vtu_helpers.h

    #ifndef OUTPUT_VTU_HELPERS_H
#define OUTPUT_VTU_HELPERS_H

    Helper functions for output_vtu.h

    This file acts as a bundle header for all VTU-related helper functions. It defines the core macros (shortcut_facets, shortcut_slice) and geometry functions (count_vertices_and_facets, populate_vertex_and_offset_arrays) that are required for VOF reconstruction.

    It also includes helper modules for writing XML and binary data.

    #include "geometry.h"
#include "fractions.h"

#if dimension == 1
coord mycs(Point point, scalar c)
{
  coord n = {1.};
  return n;
}
#elif dimension == 2
#include "myc2d.h"
#define mfacets int m = facets(n, alpha, v);
#else // dimension == 3
#include "myc.h"
#define mfacets int m = facets(n, alpha, v, 1.);
#endif

    Macro to simplify facets calculation

    #define shortcut_facets               \
  coord n;                            \
  n = mycs(point, c);                 \
  double alpha = plane_alpha(c[], n); \
  coord v[12];                        \
  mfacets;

    Macro to simplify dealing with slices

    #define shortcut_slice(n, _alpha)                                \
  double alpha = (_alpha - n.x * x - n.y * y - n.z * z) / Delta; \
  if (fabs(alpha) > 0.87)                                        \
    continue;

    Other functions

    Count the number of vertices and facets

    void count_vertices_and_facets(scalar c, long *nverts, long *nfacets) {
  foreach (serial, noauto){
    #if EMBED
    if ((c[] > 1e-6 && c[] < 1. - 1e-6) && cs[] == 1)
    #else
    if (c[] > 1e-6 && c[] < 1. - 1e-6)
    #endif
    {
      shortcut_facets
      for (int i = 0; i < m; i++)(*nverts)++;
      if (m > 0)
        (*nfacets)++;
    }
  }
}

    Populate vertex coordinates and facet offsets

    void populate_vertex_and_offset_arrays(scalar c, long nverts, long nfacets, double *pt_array_x, double *pt_array_y, double *pt_array_z, long *offsets) {
  long iverts = 0, ifacet = 0, offset = 0;
  foreach (serial, noauto){
    #if EMBED
    if ((c[] > 1e-6 && c[] < 1. - 1e-6) && cs[] == 1)
    #else
    if (c[] > 1e-6 && c[] < 1. - 1e-6)
    #endif
    {
      shortcut_facets // we cycle if cell is not at the interface

      // Calculate and store vertex coordinates
      coord _p = {x, y, z};
      for (int i = 0; i < m; i++){
        pt_array_x[iverts] = _p.x + v[i].x * Delta;
        pt_array_y[iverts] = _p.y + v[i].y * Delta;
        #if dimension == 3
          pt_array_z[iverts] = _p.z + v[i].z * Delta;
        #endif
        iverts++;
      }
      // Store facet offset if there are vertices in the facet
      if (m > 0){
        offset += m;
        offsets[ifacet] = offset;
        ifacet++;
      }
    }
  }
}

    Populate arrays with values at the facets

    void populate_facet_arrays(scalar c, scalar s, long nverts, long nfacets, double *val_array_s) {
  long ifacet = 0;
  foreach (serial, noauto){
    #if EMBED
    if ((c[] > 1e-6 && c[] < 1. - 1e-6) && cs[] == 1)
    #else
    if (c[] > 1e-6 && c[] < 1. - 1e-6)
    #endif
    {
      shortcut_facets // we cycle if cell is not at the interface

      if (m > 0){
        val_array_s[ifacet] = s[];
        ifacet++;
      }
    }
  }
}

    XML Formatting Helpers

    Includes functions for writing VTU/PVTU headers and XML metadata (light data).

    Binary Data Writing Helpers

    Includes functions for iterating over the grid and writing heavy binary data.

    #include "output_vtu_helpers_data.h"

#endif