grid_reg2d.c

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// Copyright (c) 2024 The YAC Authors
//
// SPDX-License-Identifier: BSD-3-Clause
 
#include "grids/basic_grid_data.h"
#include "grid_reg2d_common.h"
#include "geometry.h"
#include "utils_common.h"
 
static struct yac_basic_grid_data yac_generate_basic_grid_data_reg_2d_(
  size_t nbr_vertices[2], int cyclic[2],
  double *lon_vertices, double *lat_vertices,
  void (*LLtoXYZ_ptr)(double, double, double[])) {
 
  YAC_ASSERT(!cyclic[1], "cyclic[1] != 0 not yet supported")
 
  size_t num_cells_2d[2] =
    {nbr_vertices[0] - (cyclic[0]?0:1), nbr_vertices[1] - (cyclic[1]?0:1)};
  size_t num_vertices_2d[2] = {num_cells_2d[0] + (cyclic[0]?0:1), num_cells_2d[1] + 1};
  size_t num_vertices = num_vertices_2d[0] * num_vertices_2d[1];
  size_t num_edges =
    (num_cells_2d[0] + (cyclic[0]?0:1)) * num_cells_2d[1] +
    num_cells_2d[0] * (num_cells_2d[1] + 1);
 
  yac_coordinate_pointer vertex_coordinates =
    xmalloc(num_vertices * sizeof(*vertex_coordinates));
  for (size_t i = 0, k = 0; i < num_vertices_2d[1]; ++i) {
    for (size_t j = 0; j < num_vertices_2d[0]; ++j, ++k) {
      LLtoXYZ_ptr(lon_vertices[j], lat_vertices[i],
                  &(vertex_coordinates[k][0]));
    }
  }
 
  enum yac_edge_type * edge_type = xmalloc(num_edges * sizeof(*edge_type));
  if (!cyclic[0]) {
    for (size_t i = 0, k = 0; i < num_cells_2d[1]; ++i) {
      for (size_t j = 0; j < num_vertices_2d[0]; ++j, k += 2) {
        edge_type[k] = YAC_LAT_CIRCLE_EDGE;
        edge_type[k+1] = YAC_LON_CIRCLE_EDGE;
      }
      --k;
      edge_type[k-1] = YAC_LON_CIRCLE_EDGE;
    }
  } else {
    for (size_t i = 1; i < num_edges; ++i)
      edge_type[i] = (i&1)?YAC_LAT_CIRCLE_EDGE:YAC_LON_CIRCLE_EDGE;
    for (size_t i = 0; i < num_cells_2d[1]; ++i) {
      edge_type[2*i*num_cells_2d[0]] = YAC_LAT_CIRCLE_EDGE;
      edge_type[2*(i+1)*num_cells_2d[0]-1] = YAC_LON_CIRCLE_EDGE;
    }
  }
  for (size_t i = num_edges - num_cells_2d[0]; i < num_edges; ++i)
    edge_type[i] = YAC_LAT_CIRCLE_EDGE;
 
  struct yac_basic_grid_data grid =
    yac_generate_basic_grid_data_reg2d_common(nbr_vertices, cyclic);
  grid.vertex_coordinates = vertex_coordinates;
  grid.edge_type = edge_type;
  return grid;
}
 
struct yac_basic_grid_data yac_generate_basic_grid_data_reg_2d(
  size_t nbr_vertices[2], int cyclic[2],
  double *lon_vertices, double *lat_vertices) {
 
  return
    yac_generate_basic_grid_data_reg_2d_(
      nbr_vertices, cyclic, lon_vertices, lat_vertices, LLtoXYZ);
}
 
struct yac_basic_grid_data yac_generate_basic_grid_data_reg_2d_deg(
  size_t nbr_vertices[2], int cyclic[2],
  double *lon_vertices, double *lat_vertices) {
 
  return
    yac_generate_basic_grid_data_reg_2d_(
      nbr_vertices, cyclic, lon_vertices, lat_vertices, LLtoXYZ_deg);
}