elements.c

#include <stdlib.h>

#include "elements.h"
#include "domain.h"

// Creates elements and stores it in the triangular elements list
int create_triangular_elements_for_cartesian_domain(domain* cartesian_domain)
{
  int i, j;
  int nT, sqid, tid;
  vertex* vertex1;
  vertex* vertex2;
  vertex* vertex3;
  vertex* vertex4;

#define CDN (cartesian_domain->cartesian_grid->N + 1)
#define CDV (cartesian_domain->vertices)

  nT = 2 * (CDN - 1) * (CDN - 1);
  _total_grid_elements = 0;
  _triangular_elements = calloc(nT, sizeof(triangular_element));

  for(i = 0; i < CDN - 1; i++)
    {
      for(j = 0; j < CDN - 1; j++)
        {
          sqid = i * (CDN - 1) + j;
          tid = 2 * sqid;

          vertex1 = &CDV[i * CDN + j];
          vertex2 = &CDV[i * CDN + j + 1];
          vertex3 = &CDV[(i + 1) * CDN + j];
          vertex4 = &CDV[(i + 1) * CDN + j + 1];

          _triangular_elements[tid].id = tid;
          _triangular_elements[tid].cartesian_domain = cartesian_domain;
          _triangular_elements[tid].grid_vertex[0] = vertex3;
          _triangular_elements[tid].grid_vertex[1] = vertex1;
          _triangular_elements[tid].grid_vertex[2] = vertex4;
          _total_grid_elements++;

          _triangular_elements[tid + 1].id = tid + 1;
          _triangular_elements[tid + 1].cartesian_domain = cartesian_domain;
          _triangular_elements[tid + 1].grid_vertex[0] = vertex2;
          _triangular_elements[tid + 1].grid_vertex[1] = vertex4;
          _triangular_elements[tid + 1].grid_vertex[2] = vertex1;
          _total_grid_elements++;
        }
    }

#undef CDN
#undef CDV

  return 0;
}

// Add element indices to subdomains
int add_triangular_elements_to_subdomains(domain* cartesian_domain, int idx)
{
  int i, j, count;
  int nT, sqid, tid;

#define CSD (cartesian_domain->subdomains)
#define CDN (cartesian_domain->cartesian_grid->N + 1)

  nT = 2 * (CSD[idx].dimX - 1) * (CSD[idx].dimY - 1);
  CSD[idx].elements = calloc(nT, sizeof(int));
  CSD[idx].elements_count = 0;

  count = 0;
  for(i = CSD[idx].bottom_left_y; i < CSD[idx].top_right_y; i++)
    {
      for(j = CSD[idx].bottom_left_x; j < CSD[idx].top_right_x; j++)
        {
          sqid = i * (CDN - 1) + j;
          tid = 2 * sqid;
          CSD[idx].elements[count++] = tid++;
          CSD[idx].elements[count++] = tid;
          CSD[idx].elements_count += 2;           // Even though this can be initialized
          // like allocating space, this can be used to debug later
        }
    }

#undef CSD
#undef CDN

  return 0;
}


// Remove all triangular elements from heap
int cleanup_triangular_elements()
{
  if(_triangular_elements != NULL)
    {
      free(_triangular_elements);
    }

  return 0;
}