/*
  This file is part of CDO. CDO is a collection of Operators to manipulate and analyse Climate model Data.

  Author: Uwe Schulzweida

*/

#include <vector>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <numbers>

namespace
{
struct dimension
{
  int lower;
  int extent;
  int mult;
};

struct array
{
  char *addr;
  int offset;
  struct dimension dim[3];
};

struct cart
{
  double x[3] = { 0, 0, 0 };
};

struct geo
{
  double lon;
  double lat;
};

struct polygon
{
  int type;
  struct geo center;
  struct geo boundary[6];
};
}  // namespace

constexpr double pid5 = 0.2 * std::numbers::pi;
// constexpr double pid180 = 180.0/std::numbers::pi;

constexpr int ispokes[12] = {
  1, 0, -1, -1, 0, 1, 0, 1, 1, 0, -1, -1,
};

constexpr int pentagon = 5;
constexpr int hexagon = 6;

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

void
gme_factorni(int kni, int *kni2, int *kni3)
{
  /**********************************************************************/
  /* factorni computes the factors of the integer input kni, assuming   */
  /* that kni decomposes into kni3 factors (kni3 either 0 or 1) of "3"  */
  /* and kni2 (kni2 > 0) factors of "2". The subroutine returns the     */
  /* number of factors of "3", kni3, number of factors of "2", kni2.    */
  /* Bails out in case of error.                                        */
  /**********************************************************************/
  /*  Author: D. Majewski, DWD, January 2000                            */
  /**********************************************************************/
  /*  Input                                                             */
  /*  kni     INT   number of intervals on a main triangle side         */
  /**********************************************************************/
  /*  Output                                                            */
  /*  kni2    INT      exponent of "2", kni2 > 0                        */
  /*  kni3    INT      exponent of "3", either 0 or 1                   */
  /**********************************************************************/

  unsigned lim = 9999;
  int mx = kni;

  *kni2 = 0;
  *kni3 = 0;

  while (mx > 1 && --lim)
  {
    if (mx % 2 == 0)
    {
      *kni2 = *kni2 + 1;
      mx = mx / 2;
    }
    else if (mx % 3 == 0)
    {
      *kni3 = *kni3 + 1;
      mx = mx / 3;
    }
    else
    { /* error return */
    }
  }

  // kni3 must not be greater than
  if (*kni3 > 1) { /* error return */ }
}

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

static int
pow_ii(int x, int n)
{
  if (n <= 0)
  {
    if (n == 0 || x == 1) return 1;
    if (x != -1) return (x == 0) ? 1 / x : 0;
    n = -n;
  }

  int pow;
  for (pow = 1;;)
  {
    if (n & 01) pow *= x;
    if (n >>= 1)
      x *= x;
    else
      break;
  }

  return pow;
}

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

static struct cart
circum_center(struct cart *v0, struct cart *v1, struct cart *v2)
{
  struct cart center;
  struct cart e1;
  struct cart e2;
  struct cart cu;

  double *ptmp1 = e1.x;
  double *ptmp2 = v1->x;
  double *ptmp3 = v0->x;

  for (int j = 0; j < 3; ++j)
  {
    {
      *ptmp1 = *ptmp2 - *ptmp3;
      ptmp1++;
    }
    ptmp3++;
    ptmp2++;
  }

  ptmp1 = e2.x;
  ptmp2 = v2->x;
  ptmp3 = v0->x;
  for (int j = 0; j < 3; ++j)
  {
    {
      *ptmp1 = *ptmp2 - *ptmp3;
      ptmp1++;
    }
    ptmp3++;
    ptmp2++;
  }

  cu.x[0] = e1.x[1] * e2.x[2] - e1.x[2] * e2.x[1];
  cu.x[1] = e1.x[2] * e2.x[0] - e1.x[0] * e2.x[2];
  cu.x[2] = e1.x[0] * e2.x[1] - e1.x[1] * e2.x[0];

  auto cnorm = std::sqrt(cu.x[0] * cu.x[0] + cu.x[1] * cu.x[1] + cu.x[2] * cu.x[2]);

  ptmp1 = center.x;
  ptmp2 = cu.x;
  for (int j = 0; j < 3; ++j)
  {
    {
      *ptmp1 = *ptmp2 / cnorm;
      ptmp1++;
    }
    ptmp2++;
  }

  return center;
}

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

static struct cart
gc2cc(struct geo *position)
{
  auto sln = std::sin(position->lon);
  auto cln = std::cos(position->lon);
  auto slt = std::sin(position->lat);
  auto clt = std::cos(position->lat);

  struct cart x;
  x.x[0] = cln * clt;
  x.x[1] = sln * clt;
  x.x[2] = slt;

  return x;
}

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

static struct geo
cc2gc(struct cart *x)
{
  struct geo position;

  if (std::abs(x->x[0]) <= 0.0) { position.lon = (x->x[1] >= 0.0) ? 0.5 * std::numbers::pi : 1.5 * std::numbers::pi; }
  else
  {
    auto tln = x->x[1] / x->x[0];
    position.lon = std::atan(tln);
    if (x->x[0] < 0.0) position.lon += std::numbers::pi;
    if (position.lon < 0.0) position.lon += 2 * std::numbers::pi;
  }

  auto r = std::sqrt(x->x[0] * x->x[0] + x->x[1] * x->x[1]);

  if (std::abs(r) <= 0.0) { position.lat = (x->x[2] > 0.0) ? 0.5 * std::numbers::pi : -0.5 * std::numbers::pi; }
  else
  {
    auto tlt = x->x[2] / r;
    position.lat = std::atan(tlt);
  }

  return position;
}

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

static void
boundary(struct polygon *poly, int kip1s, int kip1e, int kip2s, int kip2e, int knd)
{
  struct polygon *ptmp1;

  struct cart c;
  struct cart x1;
  struct cart x2;
  struct cart v[6];

  int jm, jm1, jm2;

  struct array polyinfo;

  int tmp1, tmp2, tmp3, tmp4, tmp5;

  polyinfo.offset = 0;
  polyinfo.dim[0].lower = kip1s;
  tmp1 = kip1e - polyinfo.dim[0].lower + 1;
  if (tmp1 < 0) tmp1 = 0;
  polyinfo.dim[0].extent = tmp1;
  polyinfo.dim[0].mult = 1;
  polyinfo.offset -= polyinfo.dim[0].lower;
  tmp2 = tmp1;
  polyinfo.dim[1].lower = kip2s;
  tmp1 = kip2e - polyinfo.dim[1].lower + 1;
  if (tmp1 < 0) tmp1 = 0;
  polyinfo.dim[1].extent = tmp1;
  polyinfo.dim[1].mult = tmp2;
  polyinfo.offset -= polyinfo.dim[1].lower * polyinfo.dim[1].mult;
  tmp2 *= tmp1;
  polyinfo.dim[2].lower = 1;
  tmp1 = knd;
  if (tmp1 < 0) tmp1 = 0;
  polyinfo.dim[2].extent = tmp1;
  polyinfo.dim[2].mult = tmp2;
  polyinfo.offset -= polyinfo.dim[2].mult;
  tmp4 = polyinfo.dim[1].mult;
  tmp5 = polyinfo.dim[2].mult;
  tmp3 = polyinfo.offset;

  for (int jd = 1; jd <= knd; jd++)
  {
    for (int j2 = kip2s; j2 <= kip2e; ++j2)
    {
      for (int j1 = kip1s; j1 <= kip1e; ++j1)
      {
        ptmp1 = &poly[j1 + tmp4 * j2 + tmp5 * jd + tmp3];
        c = gc2cc(&ptmp1->center);
        for (jm = 1; jm <= ptmp1->type; jm++)
        {
          jm1 = jm;
          jm2 = (jm % ptmp1->type) + 1;
          x1 = gc2cc(&ptmp1->boundary[jm1 - 1]);
          x2 = gc2cc(&ptmp1->boundary[jm2 - 1]);
          if (jd < 6) { v[jm - 1] = circum_center(&c, &x1, &x2); }
          else
          {
            v[jm - 1] = circum_center(&c, &x2, &x1);
          }
        }
        if (jd < 6)
          for (jm = 0; jm < ptmp1->type; jm++) ptmp1->boundary[jm] = cc2gc(&v[jm]);
        else
          for (jm = 0; jm < ptmp1->type; jm++) ptmp1->boundary[ptmp1->type - jm - 1] = cc2gc(&v[jm]);
      }
    }
  }

  return;
}

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

static void
neighbours(double *px1, double *px2, int kipx1s, int kipx1e, int kipx2s, int kipx2e, int kndx, struct polygon *poly, int kip1s,
           int kip1e, int kip2s, int kip2e, int knd)
{
  struct polygon *ptmp1;
  struct array px1info, px2info, polyinfo;

  int tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8, tmp9;
  int tmp10, tmp11, tmp12, tmp13, tmp14, tmp15;

  px1info.offset = 0;
  px1info.dim[0].lower = kipx1s;
  tmp1 = kipx1e - px1info.dim[0].lower + 1;
  if (tmp1 < 0) tmp1 = 0;
  px1info.dim[0].extent = tmp1;
  px1info.dim[0].mult = 1;
  px1info.offset -= px1info.dim[0].lower;
  tmp2 = tmp1;
  px1info.dim[1].lower = kipx2s;
  tmp1 = kipx2e - px1info.dim[1].lower + 1;
  if (tmp1 < 0) tmp1 = 0;
  px1info.dim[1].extent = tmp1;
  px1info.dim[1].mult = tmp2;
  px1info.offset -= px1info.dim[1].lower * px1info.dim[1].mult;
  tmp2 *= tmp1;
  px1info.dim[2].lower = 1;
  tmp1 = kndx;
  if (tmp1 < 0) tmp1 = 0;
  px1info.dim[2].extent = tmp1;
  px1info.dim[2].mult = tmp2;
  px1info.offset -= px1info.dim[2].mult;
  tmp4 = px1info.dim[1].mult;
  tmp5 = px1info.dim[2].mult;
  tmp3 = px1info.offset;

  px2info.offset = 0;
  px2info.dim[0].lower = kipx1s;
  tmp6 = kipx1e - px2info.dim[0].lower + 1;
  if (tmp6 < 0) tmp6 = 0;
  px2info.dim[0].extent = tmp6;
  px2info.dim[0].mult = 1;
  px2info.offset -= px2info.dim[0].lower;
  tmp7 = tmp6;
  px2info.dim[1].lower = kipx2s;
  tmp6 = kipx2e - px2info.dim[1].lower + 1;
  if (tmp6 < 0) tmp6 = 0;
  px2info.dim[1].extent = tmp6;
  px2info.dim[1].mult = tmp7;
  px2info.offset -= px2info.dim[1].lower * px2info.dim[1].mult;
  tmp7 *= tmp6;
  px2info.dim[2].lower = 1;
  tmp6 = kndx;
  if (tmp6 < 0) tmp6 = 0;
  px2info.dim[2].extent = tmp6;
  px2info.dim[2].mult = tmp7;
  px2info.offset -= px2info.dim[2].mult;
  tmp9 = px2info.dim[1].mult;
  tmp10 = px2info.dim[2].mult;
  tmp8 = px2info.offset;

  polyinfo.offset = 0;
  polyinfo.dim[0].lower = kip1s;
  tmp11 = kip1e - polyinfo.dim[0].lower + 1;
  if (tmp11 < 0) tmp11 = 0;
  polyinfo.dim[0].extent = tmp11;
  polyinfo.dim[0].mult = 1;
  polyinfo.offset -= polyinfo.dim[0].lower;
  tmp12 = tmp11;
  polyinfo.dim[1].lower = kip2s;
  tmp11 = kip2e - polyinfo.dim[1].lower + 1;
  if (tmp11 < 0) tmp11 = 0;
  polyinfo.dim[1].extent = tmp11;
  polyinfo.dim[1].mult = tmp12;
  polyinfo.offset -= polyinfo.dim[1].lower * polyinfo.dim[1].mult;
  tmp12 *= tmp11;
  polyinfo.dim[2].lower = 1;
  tmp11 = knd;
  if (tmp11 < 0) tmp11 = 0;
  polyinfo.dim[2].extent = tmp11;
  polyinfo.dim[2].mult = tmp12;
  polyinfo.offset -= polyinfo.dim[2].mult;
  tmp14 = polyinfo.dim[1].mult;
  tmp15 = polyinfo.dim[2].mult;
  tmp13 = polyinfo.offset;

  for (int jd = 1; jd <= kndx; jd++)
  {
    for (int j2 = kipx2s + 1; j2 <= kipx2e - 1; ++j2)
    {
      for (int j1 = kipx1s + 1; j1 <= kipx1e - 1; ++j1)
      {
        ptmp1 = &poly[j1 + tmp14 * j2 + tmp15 * jd + tmp13];
        ptmp1->center.lon = px1[j1 + tmp4 * j2 + tmp5 * jd + tmp3];
        ptmp1->center.lat = px2[j1 + tmp9 * j2 + tmp10 * jd + tmp8];

        if (j1 == kipx1s + 1 && j2 == kipx2s + 1)
        {
          ptmp1->type = pentagon;

          for (int jm = 1; jm <= 5; jm++)
          {
            if (jd < 6)
            {
              ptmp1->boundary[jm - 1].lon = px1[kipx1s + 1 + tmp4 * (kipx2s + 2) + tmp5 * (jm) + tmp3];
              ptmp1->boundary[jm - 1].lat = px2[kipx1s + 1 + tmp9 * (kipx2s + 2) + tmp10 * (jm) + tmp8];
            }
            else
            {
              ptmp1->boundary[jm - 1].lon = px1[kipx1s + 1 + tmp4 * (kipx2s + 2) + tmp5 * (jm + 5) + tmp3];
              ptmp1->boundary[jm - 1].lat = px2[kipx1s + 1 + tmp9 * (kipx2s + 2) + tmp10 * (jm + 5) + tmp8];
            }
          }
        }
        else if (j1 == kipx1e - 1 && j2 == kipx2s + 1)
        {
          ptmp1->type = pentagon;

          ptmp1->boundary[0].lon = px1[kipx1e - 1 + tmp4 * (kipx2s + 2) + tmp5 * jd + tmp3];
          ptmp1->boundary[0].lat = px2[kipx1e - 1 + tmp9 * (kipx2s + 2) + tmp10 * jd + tmp8];
          ptmp1->boundary[1].lon = px1[kipx1e - 2 + tmp4 * (kipx2s + 2) + tmp5 * jd + tmp3];
          ptmp1->boundary[1].lat = px2[kipx1e - 2 + tmp9 * (kipx2s + 2) + tmp10 * jd + tmp8];
          ptmp1->boundary[2].lon = px1[kipx1e - 2 + tmp4 * (kipx2s + 1) + tmp5 * jd + tmp3];
          ptmp1->boundary[2].lat = px2[kipx1e - 2 + tmp9 * (kipx2s + 1) + tmp10 * jd + tmp8];
          ptmp1->boundary[3].lon = px1[kipx1e - 1 + tmp4 * (kipx2s) + tmp5 * jd + tmp3];
          ptmp1->boundary[3].lat = px2[kipx1e - 1 + tmp9 * (kipx2s) + tmp10 * jd + tmp8];
          ptmp1->boundary[4].lon = px1[kipx1e + tmp4 * (kipx2s + 1) + tmp5 * jd + tmp3];
          ptmp1->boundary[4].lat = px2[kipx1e + tmp9 * (kipx2s + 1) + tmp10 * jd + tmp8];
        }
        else if (j1 == kipx1s + 1 && j2 == kipx2e - 1)
        {
          ptmp1->type = pentagon;

          ptmp1->boundary[0].lon = px1[kipx1s + 2 + tmp4 * (kipx2e - 2) + tmp5 * jd + tmp3];
          ptmp1->boundary[0].lat = px2[kipx1s + 2 + tmp9 * (kipx2e - 2) + tmp10 * jd + tmp8];
          ptmp1->boundary[1].lon = px1[kipx1s + 2 + tmp4 * (kipx2e - 1) + tmp5 * jd + tmp3];
          ptmp1->boundary[1].lat = px2[kipx1s + 2 + tmp9 * (kipx2e - 1) + tmp10 * jd + tmp8];
          ptmp1->boundary[2].lon = px1[kipx1s + 1 + tmp4 * (kipx2e) + tmp5 * jd + tmp3];
          ptmp1->boundary[2].lat = px2[kipx1s + 1 + tmp9 * (kipx2e) + tmp10 * jd + tmp8];
          ptmp1->boundary[3].lon = px1[kipx1s + tmp4 * (kipx2e - 1) + tmp5 * jd + tmp3];
          ptmp1->boundary[3].lat = px2[kipx1s + tmp9 * (kipx2e - 1) + tmp10 * jd + tmp8];
          ptmp1->boundary[4].lon = px1[kipx1s + 1 + tmp4 * (kipx2e - 2) + tmp5 * jd + tmp3];
          ptmp1->boundary[4].lat = px2[kipx1s + 1 + tmp9 * (kipx2e - 2) + tmp10 * jd + tmp8];
        }
        else if (j1 == kipx1e - 1 && j2 == kipx2e - 1)
        {
          ptmp1->type = pentagon;

          ptmp1->boundary[0].lon = px1[kipx1e + tmp4 * (kipx2e) + tmp5 * jd + tmp3];
          ptmp1->boundary[0].lat = px2[kipx1e + tmp9 * (kipx2e) + tmp10 * jd + tmp8];
          ptmp1->boundary[1].lon = px1[kipx1e - 2 + tmp4 * (kipx2e) + tmp5 * jd + tmp3];
          ptmp1->boundary[1].lat = px2[kipx1e - 2 + tmp9 * (kipx2e) + tmp10 * jd + tmp8];
          ptmp1->boundary[2].lon = px1[kipx1e - 2 + tmp4 * (kipx2e - 1) + tmp5 * jd + tmp3];
          ptmp1->boundary[2].lat = px2[kipx1e - 2 + tmp9 * (kipx2e - 1) + tmp10 * jd + tmp8];
          ptmp1->boundary[3].lon = px1[kipx1e - 1 + tmp4 * (kipx2e - 2) + tmp5 * jd + tmp3];
          ptmp1->boundary[3].lat = px2[kipx1e - 1 + tmp9 * (kipx2e - 2) + tmp10 * jd + tmp8];
          ptmp1->boundary[4].lon = px1[kipx1e + tmp4 * (kipx2e - 2) + tmp5 * jd + tmp3];
          ptmp1->boundary[4].lat = px2[kipx1e + tmp9 * (kipx2e - 2) + tmp10 * jd + tmp8];
        }
        else
        {
          for (int jm = 1; jm <= 6; jm++)
          {
            ptmp1->type = hexagon;

            int js1 = j1 + ispokes[jm - 1];
            int js2 = j2 + ispokes[jm + 5];
            ptmp1->boundary[jm - 1].lon = px1[js1 + tmp4 * js2 + tmp5 * jd + tmp3];
            ptmp1->boundary[jm - 1].lat = px2[js1 + tmp9 * js2 + tmp10 * jd + tmp8];
          }
        }
      }
    }
  }

  return;
}

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

static void
xd(double *p, int kip1s, int kip1e, int kip2s, int kip2e, int knd, double *px, int kipx1s, int kipx1e, int kipx2s, int kipx2e,
   int kndx)
{
  struct array pinfo, pxinfo;

  int tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8, tmp9, tmp10;

  pinfo.offset = 0;
  pinfo.dim[0].lower = kip1s;
  tmp1 = kip1e - pinfo.dim[0].lower + 1;
  if (tmp1 < 0) tmp1 = 0;
  pinfo.dim[0].extent = tmp1;
  pinfo.dim[0].mult = 1;
  pinfo.offset -= pinfo.dim[0].lower;
  tmp2 = tmp1;
  pinfo.dim[1].lower = kip2s;
  tmp1 = kip2e - pinfo.dim[1].lower + 1;
  if (tmp1 < 0) tmp1 = 0;
  pinfo.dim[1].extent = tmp1;
  pinfo.dim[1].mult = tmp2;
  pinfo.offset -= pinfo.dim[1].lower * pinfo.dim[1].mult;
  tmp2 *= tmp1;
  pinfo.dim[2].lower = 1;
  tmp1 = knd;
  if (tmp1 < 0) tmp1 = 0;
  pinfo.dim[2].extent = tmp1;
  pinfo.dim[2].mult = tmp2;
  pinfo.offset -= pinfo.dim[2].mult;
  tmp4 = pinfo.dim[1].mult;
  tmp5 = pinfo.dim[2].mult;
  tmp3 = pinfo.offset;

  pxinfo.offset = 0;
  pxinfo.dim[0].lower = kipx1s;
  tmp6 = kipx1e - pxinfo.dim[0].lower + 1;
  if (tmp6 < 0) tmp6 = 0;
  pxinfo.dim[0].extent = tmp6;
  pxinfo.dim[0].mult = 1;
  pxinfo.offset -= pxinfo.dim[0].lower;
  tmp7 = tmp6;
  pxinfo.dim[1].lower = kipx2s;
  tmp6 = kipx2e - pxinfo.dim[1].lower + 1;
  if (tmp6 < 0) tmp6 = 0;
  pxinfo.dim[1].extent = tmp6;
  pxinfo.dim[1].mult = tmp7;
  pxinfo.offset -= pxinfo.dim[1].lower * pxinfo.dim[1].mult;
  tmp7 *= tmp6;
  pxinfo.dim[2].lower = 1;
  tmp6 = kndx;
  if (tmp6 < 0) tmp6 = 0;
  pxinfo.dim[2].extent = tmp6;
  pxinfo.dim[2].mult = tmp7;
  pxinfo.offset -= pxinfo.dim[2].mult;
  tmp9 = pxinfo.dim[1].mult;
  tmp10 = pxinfo.dim[2].mult;
  tmp8 = pxinfo.offset;
  // tmp1 = pxinfo.dim[0].extent;
  // tmp2 = pxinfo.dim[1].extent;
  // tmp6 = pxinfo.dim[2].extent;

  for (int jd = 1; jd <= knd; jd++)
  {
    for (int j2 = kip2s; j2 <= kip2e; ++j2)
    {
      for (int j1 = kip1s; j1 <= kip1e; ++j1) { px[j1 + tmp9 * j2 + tmp10 * jd + tmp8] = p[j1 + tmp4 * j2 + tmp5 * jd + tmp3]; }
    }
  }

  int mi1sm1 = kip1s - 1;
  int mi1ep1 = kip1e + 1;
  int mi2sm1 = kip2s - 1;
  int mi2ep1 = kip2e + 1;

  for (int jd = 1; jd <= knd; jd++)
  {
    int mns = (jd - 1) / 5;
    int mpe = jd + 1 - (jd / (5 * (1 + mns))) * 5;
    int mpw = jd - 1 + ((mns * 10 + 6 - jd) / (5 * (1 + mns))) * 5;
    int mae = jd + 5 - 9 * mns - 5 * (jd / 10);
    int maw = jd + 4 + ((6 - jd) / 5) * 5 - 9 * mns;
    int mpp = jd + 3 - ((jd + 2) / 5) * 5 + 5 * mns;
    for (int j = kip2s; j <= kip1e; ++j)
    {
      px[j + tmp9 * mi2sm1 + tmp10 * jd + tmp8] = p[kip1s + 1 + tmp4 * j + tmp5 * mpw + tmp3];
      px[mi1sm1 + tmp9 * (j + 1) + tmp10 * jd + tmp8] = p[j - 1 + tmp4 * (kip2s + 1) + tmp5 * mpe + tmp3];
      px[mi1ep1 + tmp9 * j + tmp10 * jd + tmp8] = p[kip1e + 1 - j + tmp4 * (kip2e - 1) + tmp5 * maw + tmp3];
      px[j - 1 + tmp9 * mi2ep1 + tmp10 * jd + tmp8] = p[kip1e - 1 + tmp4 * (kip2e + 1 - j) + tmp5 * mae + tmp3];
    }
    px[mi1sm1 + tmp9 * kip2s + tmp10 * jd + tmp8] = p[kip1s + 1 + tmp4 * kip2s + tmp5 * mpp + tmp3];
    px[kip1s + tmp9 * mi2sm1 + tmp10 * jd + tmp8] = p[kip1s + 1 + tmp4 * kip2s + tmp5 * mpp + tmp3];

    px[mi1ep1 + tmp9 * mi2sm1 + tmp10 * jd + tmp8] = px[kip1e + tmp9 * mi2sm1 + tmp10 * jd + tmp8];
    px[mi1sm1 + tmp9 * mi2ep1 + tmp10 * jd + tmp8] = px[mi1sm1 + tmp9 * kip2e + tmp10 * jd + tmp8];

    px[mi1ep1 + tmp9 * kip2e + tmp10 * jd + tmp8] = p[kip1e - 1 + tmp4 * kip2s + tmp5 * mae + tmp3];
    px[kip1e + tmp9 * mi2ep1 + tmp10 * jd + tmp8] = p[kip1e - 1 + tmp4 * kip2s + tmp5 * mae + tmp3];

    px[mi1sm1 + tmp9 * mi2sm1 + tmp10 * jd + tmp8] = px[kip1s + tmp9 * mi2sm1 + tmp10 * jd + tmp8];
    px[mi1ep1 + tmp9 * mi2ep1 + tmp10 * jd + tmp8] = px[kip1e + tmp9 * mi2ep1 + tmp10 * jd + tmp8];
  }

  return;
}

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

static void
tricntr(double *pxn, int kig1s, int kig1e, int kig2s, int kig2e, int knd, int kjd, int kni)
{
  (void) knd;

  int id1 = kig1e - kig1s + 1;
  int id2 = id1 * (kig2e - kig2s + 1);
  int id3 = id2 * 3;
  int ioffset = -(id1 + id2 + id3);

  for (int j = 1; j <= 2; ++j)
  {
    int mi1 = j * kni / 3;
    int mi2 = (j - 1) * kni + 1;
    pxn[mi1 + id1 * (mi1 + 1) + id2 * 1 + id3 * kjd + ioffset] = pxn[mi2 - 1 + id1 * (mi2) + id2 * 1 + id3 * kjd + ioffset]
                                                                 + pxn[kni + id1 * 1 + id2 * 1 + id3 * kjd + ioffset]
                                                                 + pxn[0 + id1 * (kni + 1) + id2 * 1 + id3 * kjd + ioffset];
    pxn[mi1 + id1 * (mi1 + 1) + id2 * 2 + id3 * kjd + ioffset] = pxn[mi2 - 1 + id1 * (mi2) + id2 * 2 + id3 * kjd + ioffset]
                                                                 + pxn[kni + id1 * 1 + id2 * 2 + id3 * kjd + ioffset]
                                                                 + pxn[0 + id1 * (kni + 1) + id2 * 2 + id3 * kjd + ioffset];
    pxn[mi1 + id1 * (mi1 + 1) + id2 * 3 + id3 * kjd + ioffset] = pxn[mi2 - 1 + id1 * (mi2) + id2 * 3 + id3 * kjd + ioffset]
                                                                 + pxn[kni + id1 * 1 + id2 * 3 + id3 * kjd + ioffset]
                                                                 + pxn[0 + id1 * (kni + 1) + id2 * 3 + id3 * kjd + ioffset];
    /* Normalize to unit-sphere */

    double r1 = pxn[mi1 + id1 * (mi1 + 1) + id2 * 1 + id3 * kjd + ioffset];
    double r2 = pxn[mi1 + id1 * (mi1 + 1) + id2 * 2 + id3 * kjd + ioffset];
    double r3 = pxn[mi1 + id1 * (mi1 + 1) + id2 * 3 + id3 * kjd + ioffset];
    double zxnorm = 1.0 / std::sqrt(r1 * r1 + r2 * r2 + r3 * r3);

    pxn[mi1 + id1 * (mi1 + 1) + id2 * 1 + id3 * kjd + ioffset]
        = zxnorm * pxn[mi1 + id1 * (mi1 + 1) + id2 * 1 + id3 * kjd + ioffset];
    pxn[mi1 + id1 * (mi1 + 1) + id2 * 2 + id3 * kjd + ioffset]
        = zxnorm * pxn[mi1 + id1 * (mi1 + 1) + id2 * 2 + id3 * kjd + ioffset];
    pxn[mi1 + id1 * (mi1 + 1) + id2 * 3 + id3 * kjd + ioffset]
        = zxnorm * pxn[mi1 + id1 * (mi1 + 1) + id2 * 3 + id3 * kjd + ioffset];
  }

  return;
} /* tricntr */

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

static void
gcpt(double *pxn, int kig1s, int kig1e, int kig2s, int kig2e, int knd, int kjd, double pgamma, int ki1, int kj1, int ki2, int kj2,
     int ki, int kj)
{
  (void) knd;

  // Calculate "zchord", the Cartesian distance between x1 and x2

  int id1 = kig1e - kig1s + 1;
  int id2 = id1 * (kig2e - kig2s + 1);
  int id3 = id2 * 3;
  int ioffset = -(id1 + id2 + id3);

  int kij = ki + id1 * kj + id3 * kjd + ioffset;
  int kij1 = ki1 + id1 * kj1 + id3 * kjd + ioffset;
  int kij2 = ki2 + id1 * kj2 + id3 * kjd + ioffset;
  double r1 = (pxn[kij2 + id2 * 1] - pxn[kij1 + id2 * 1]);
  double r2 = (pxn[kij2 + id2 * 2] - pxn[kij1 + id2 * 2]);
  double r3 = (pxn[kij2 + id2 * 3] - pxn[kij1 + id2 * 3]);

  double zchord = std::sqrt((r1 * r1) + (r2 * r2) + (r3 * r3));

  // Calculate "ztheta", the great circle angle between x1 and x2
  double ztheta = 2.0 * std::asin(zchord * 0.5);

  // Calculate the weighting factors which follow from the condition that x is a point on the unit-sphere, too.
  double zbeta = std::sin(pgamma * ztheta) / std::sin(ztheta);
  double zalpha = std::sin((1.0 - pgamma) * ztheta) / std::sin(ztheta);

  // Store the (x,y,z) coordinates of the point x into the array pxn
  pxn[kij + id2 * 1] = zalpha * pxn[kij1 + id2 * 1] + zbeta * pxn[kij2 + id2 * 1];
  pxn[kij + id2 * 2] = zalpha * pxn[kij1 + id2 * 2] + zbeta * pxn[kij2 + id2 * 2];
  pxn[kij + id2 * 3] = zalpha * pxn[kij1 + id2 * 3] + zbeta * pxn[kij2 + id2 * 3];

  return;
}  // gcpt

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

static void
glo_coor(double *pxn, double *prlon, double *prlat, int kig1s, int kig1e, int kig2s, int kig2e, int knd, int kni2, int kni3)
{
  /*
   * Calculate the Cartesian coordinates of the gridpoints of the icosahedral grid on the unit sphere.
   * The grid resolution corresponds to a subdivision of the edges of the original icosahedral triangles into mni equal parts.
   */
  std::vector<int> mcosv(knd);

  int id1 = kig1e - kig1s + 1;
  int id2 = id1 * (kig2e - kig2s + 1);
  int id3 = id2 * 3;
  int ioffset = -(id1 + id2 + id3);
  int joffset = -(id1 + id2);

  // Compute angles associated with the icosahedron.
  double zw = std::acos(1.0 / (std::sin(pid5) * 2.0)) * 2.0;
  double zcosw = std::cos(zw);
  double zsinw = std::sin(zw);
  int mni = pow_ii(2, kni2) * pow_ii(3, kni3);

  // Compute the local array mcosv, i.e. the meridian angle locations
  for (int jd = 1; jd <= knd; ++jd)
  {
    if (jd % 2 == 1) { mcosv[(jd + 1) / 2 - 1] = jd - 2 - knd * ((jd - 1) / 7); }
    else
    {
      mcosv[jd / 2 + 4] = jd - 2 - knd * ((jd - 1) / 7);
    }
  }

  /**************************************************************************/
  /*     Loop over the ten diamonds computing diamond vertices (x,y,z)      */
  /*     coordinates and then iteratively bisecting them kni2 times.        */
  /*     First a trisection is performed, if required (kni3=1).             */
  for (int jd = 1; jd <= knd; ++jd)
  {
    // Toggle the hemisphere
    double zsgn = (jd >= 6) ? -1.0 : 1.0;

    // Compute the meridian angle for each diamond "home" vertex.
    double zrlon = mcosv[jd - 1] * pid5;

    /*     Every diamond has one vertex at a pole (N or S). */
    /*     Label this point (0,1,,) in each diamond, and */
    /*     initialize it to have the (x,y,z) coordinates of */
    /*     the pole point on the unit sphere. */
    int offset = id3 * jd + ioffset;
    pxn[0 + id1 + id2 * 1 + offset] = 0.0;
    pxn[0 + id1 + id2 * 2 + offset] = 0.0;
    pxn[0 + id1 + id2 * 3 + offset] = zsgn;

    /*     Now initialize the (x,y,z) coordinates of the "home" vertex, */
    /*     which defines which diamond we are talking about, and label  */
    /*     this point (mni,1,,). */
    pxn[mni + id1 + id2 * 1 + offset] = zsinw * std::cos(zrlon);
    pxn[mni + id1 + id2 * 2 + offset] = zsinw * std::sin(zrlon);
    pxn[mni + id1 + id2 * 3 + offset] = zcosw * zsgn;

    /*     Next initialize the (x,y,z) coordinates for the corner of the */
    /*     diamond on the same latitude as the (mni,1,,) vertex, which   */
    /*     is (0,mni+1,,) */
    pxn[0 + id1 * (mni + 1) + id2 * 1 + offset] = zsinw * std::cos(zrlon + 2 * pid5);
    pxn[0 + id1 * (mni + 1) + id2 * 2 + offset] = zsinw * std::sin(zrlon + 2 * pid5);
    pxn[0 + id1 * (mni + 1) + id2 * 3 + offset] = zcosw * zsgn;

    /*     Initialize the last diamond vertex, which is located */
    /*     in the opposite hemisphere as (mni,mni+1,,)          */
    pxn[mni + id1 * (mni + 1) + id2 * 1 + offset] = zsinw * std::cos(zrlon + pid5);
    pxn[mni + id1 * (mni + 1) + id2 * 2 + offset] = zsinw * std::sin(zrlon + pid5);
    pxn[mni + id1 * (mni + 1) + id2 * 3 + offset] = -(zcosw * zsgn);

    /***********************************************************************/
    /*     First a trisection is performed, if required (kni3=1).          */
    if (kni3 == 1)
    {
      int ml3 = mni / 3;

      // Trisect the rows of the diamond.
      for (int j1 = 1; j1 <= 2; ++j1)
      {
        for (int j2 = 1; j2 <= 2; ++j2)
        {
          int mi1 = (j1 - 1) * mni;
          int mi2 = j2 * ml3 + 1;
          double zgamma = (double) j2 / 3.0;
          gcpt(pxn, kig1s, kig1e, kig2s, kig2e, knd, jd, zgamma, mi1, 1, mi1, mni + 1, mi1, mi2);
        }
      }

      // Trisect the columns of the diamond.
      for (int j1 = 1; j1 <= 2; ++j1)
      {
        for (int j2 = 1; j2 <= 2; ++j2)
        {
          int mi1 = j2 * ml3;
          int mi2 = (j1 - 1) * mni + 1;
          double zgamma = (double) j2 / 3.0;
          gcpt(pxn, kig1s, kig1e, kig2s, kig2e, knd, jd, zgamma, 0, mi2, mni, mi2, mi1, mi2);
        }
      }

      // Trisect the diagonal of the diamond.
      for (int j2 = 1; j2 <= 2; ++j2)
      {
        int mi1 = mni - j2 * ml3;
        int mi2 = j2 * ml3 + 1;
        double zgamma = (double) j2 / 3.0;
        gcpt(pxn, kig1s, kig1e, kig2s, kig2e, knd, jd, zgamma, mni, 1, 0, mni + 1, mi1, mi2);
      }

      // Compute coordinates of icosahedral triangle centers.
      tricntr(pxn, kig1s, kig1e, kig2s, kig2e, knd, jd, mni);
    }

    /***********************************************************************/
    /*     Find the coordinates of the triangle nodes by iteratively       */
    /*     bisecting the diamond intervals.                                */
    for (int jb = 0; jb <= kni2 - 1; ++jb)
    {
      int mm = pow_ii(3, kni3) * pow_ii(2, jb);
      int ml = mni / mm;
      int ml2 = ml / 2;

      // Compute the rows of the diamond.
      for (int j1 = 1; j1 <= mm + 1; ++j1)
      {
        for (int j2 = 1; j2 <= mm; ++j2)
        {
          int mi1 = (j1 - 1) * ml;
          int mi2 = (j2 - 1) * ml + ml2 + 1;
          gcpt(pxn, kig1s, kig1e, kig2s, kig2e, knd, jd, 0.5, mi1, mi2 - ml2, mi1, mi2 + ml2, mi1, mi2);
        }
      }

      // Compute the columns of diamond.
      for (int j1 = 1; j1 <= mm + 1; ++j1)
      {
        for (int j2 = 1; j2 <= mm; ++j2)
        {
          int mi1 = (j2 - 1) * ml + ml2;
          int mi2 = (j1 - 1) * ml + 1;
          gcpt(pxn, kig1s, kig1e, kig2s, kig2e, knd, jd, 0.5, mi1 - ml2, mi2, mi1 + ml2, mi2, mi1, mi2);
        }
      }

      // Compute the diagonals of the diamond.
      for (int j1 = 1; j1 <= mm; ++j1)
      {
        for (int j2 = 1; j2 <= mm; ++j2)
        {
          int mi1 = (j1 - 1) * ml + ml2;
          int mi2 = (j2 - 1) * ml + ml2 + 1;
          gcpt(pxn, kig1s, kig1e, kig2s, kig2e, knd, jd, 0.5, mi1 - ml2, mi2 + ml2, mi1 + ml2, mi2 - ml2, mi1, mi2);
        }
      }
    }

    /***********************************************************************/
    /* Set pxn to 0 if it is less than 2.5 e-14 to avoid round-off errors  */
    for (int j2 = kig2s; j2 <= kig2e; ++j2)
    {
      for (int j1 = kig1s; j1 <= kig1e; ++j1)
      {
        int j12 = j1 + id1 * j2;
        if (std::abs(pxn[j12 + id2 * 1 + offset]) < 2.5e-14) { pxn[j12 + id2 * 1 + offset] = 0.0; }
        if (std::abs(pxn[j12 + id2 * 2 + offset]) < 2.5e-14) { pxn[j12 + id2 * 2 + offset] = 0.0; }
        if (std::abs(pxn[j12 + id2 * 3 + offset]) < 2.5e-14) { pxn[j12 + id2 * 3 + offset] = 0.0; }
      }
    }
  }

  /*************************************************************************/
  /*     Calculate the longitude "prlon" and the latitude "prlat";         */
  /*     only for the core of the diamonds, not the extended ones.         */

  for (int jd = 1; jd <= knd; ++jd)
  {
    int offset = id3 * jd + ioffset;
    for (int j2 = kig2s; j2 <= kig2e; ++j2)
    {
      for (int j1 = kig1s; j1 <= kig1e; ++j1)
      {
        int j12offset = j1 + id1 * j2 + id2 * jd + joffset;
        prlon[j12offset] = std::atan2(pxn[j1 + id1 * j2 + id2 * 2 + offset], pxn[j1 + id1 * j2 + id2 * 1 + offset] + 1.0e-20);
        prlat[j12offset] = std::asin(pxn[j1 + id1 * j2 + id2 * 3 + offset]);
      }
    }
  }
}  // glo_coor

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

static void
initmask(int *mask, int ni, int nd)
{
  char *ptmp2;

  struct array section;
  struct array maskinfo;

  maskinfo.offset = 0;
  maskinfo.dim[0].lower = 0;
  int tmp1 = ni + 1;
  if (tmp1 < 0) tmp1 = 0;
  maskinfo.dim[0].extent = tmp1;
  maskinfo.dim[0].mult = 1;
  maskinfo.offset -= 0;
  int tmp2 = tmp1;
  maskinfo.dim[1].lower = 1;
  tmp1 = ni + 1;
  if (tmp1 < 0) tmp1 = 0;
  maskinfo.dim[1].extent = tmp1;
  maskinfo.dim[1].mult = tmp2;
  maskinfo.offset -= maskinfo.dim[1].mult;
  tmp2 *= tmp1;
  maskinfo.dim[2].lower = 1;
  tmp1 = nd;
  if (tmp1 < 0) tmp1 = 0;
  maskinfo.dim[2].extent = tmp1;
  maskinfo.dim[2].mult = tmp2;
  maskinfo.offset -= maskinfo.dim[2].mult;
  // tmp4 = maskinfo.dim[1].mult;
  // tmp5 = maskinfo.dim[2].mult;
  // tmp3 = maskinfo.offset;
  tmp1 = maskinfo.dim[0].extent;
  tmp2 = maskinfo.dim[1].extent;
  int tmp9 = maskinfo.dim[2].extent;

  int *ptmp1 = mask;
  for (int tmp8 = 0; tmp8 < tmp9; tmp8++)
  {
    for (int tmp7 = 0; tmp7 < tmp2; tmp7++)
    {
      for (int tmp6 = 0; tmp6 < tmp1; tmp6++) *ptmp1++ = 1;
    }
  }

  for (int jd = 1; jd <= 10; jd++)
  {
    switch (jd)
    {
      case 1: break;
      case 3:
      case 4:
      case 2:
        tmp1 = 1;
        ptmp1 = mask;
        tmp2 = maskinfo.dim[0].extent;
        if (tmp2 < 0) tmp2 = 0;
        tmp1 *= maskinfo.dim[0].extent;
        tmp1 *= maskinfo.dim[1].extent;
        ptmp1 += tmp1 * (jd - 1);
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++) *ptmp1++ = 0;
        break;
      case 5:
        tmp1 = 1;
        ptmp1 = mask;
        tmp2 = maskinfo.dim[0].extent;
        if (tmp2 < 0) tmp2 = 0;
        tmp1 *= maskinfo.dim[0].extent;
        tmp1 *= maskinfo.dim[1].extent;
        ptmp1 += tmp1 * (jd - 1);
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++) *ptmp1++ = 0;

        tmp1 = 4;
        section.addr = (char *) mask;
        section.offset = 0;
        tmp1 *= maskinfo.dim[0].extent;
        section.dim[0].mult = tmp1;
        section.dim[0].extent = maskinfo.dim[1].extent;
        if (section.dim[0].extent < 0) section.dim[0].extent = 0;
        section.offset -= section.dim[0].mult;
        section.dim[0].lower = 1;
        tmp1 *= maskinfo.dim[1].extent;
        section.addr += tmp1 * (jd - 1);
        tmp2 = section.dim[0].extent;
        ptmp2 = section.addr;
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++)
        {
          *((int *) ptmp2) = 0;
          ptmp2 += section.dim[0].mult;
        }
        break;
      case 6:
        tmp1 = 1;
        ptmp1 = mask;
        tmp2 = maskinfo.dim[0].extent;
        if (tmp2 < 0) tmp2 = 0;
        tmp1 *= maskinfo.dim[0].extent;
        ptmp1 += tmp1 * ni;
        tmp1 *= maskinfo.dim[1].extent;
        ptmp1 += tmp1 * (jd - 1);
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++) *ptmp1++ = 0;

        tmp1 = 4;
        section.addr = (char *) mask;
        section.offset = 0;
        section.addr += tmp1 * ni;
        tmp1 *= maskinfo.dim[0].extent;
        section.dim[0].mult = tmp1;
        section.dim[0].extent = maskinfo.dim[1].extent;
        if (section.dim[0].extent < 0) section.dim[0].extent = 0;
        section.offset -= section.dim[0].mult;
        section.dim[0].lower = 1;
        tmp1 *= maskinfo.dim[1].extent;
        section.addr += tmp1 * (jd - 1);
        tmp2 = section.dim[0].extent;
        ptmp2 = section.addr;
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++)
        {
          *((int *) ptmp2) = 0;
          ptmp2 += section.dim[0].mult;
        }
        break;
      case 8:
      case 9:
      case 7:
        tmp1 = 1;
        ptmp1 = mask;
        tmp2 = maskinfo.dim[0].extent;
        if (tmp2 < 0) tmp2 = 0;
        tmp1 *= maskinfo.dim[0].extent;
        tmp1 *= maskinfo.dim[1].extent;
        ptmp1 += tmp1 * (jd - 1);
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++) *ptmp1++ = 0;

        tmp1 = 1;
        ptmp1 = mask;
        tmp2 = maskinfo.dim[0].extent;
        if (tmp2 < 0) tmp2 = 0;
        tmp1 *= maskinfo.dim[0].extent;
        ptmp1 += tmp1 * ni;
        tmp1 *= maskinfo.dim[1].extent;
        ptmp1 += tmp1 * (jd - 1);
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++) *ptmp1++ = 0;

        tmp1 = 4;
        section.addr = (char *) mask;
        section.offset = 0;
        section.addr += tmp1 * ni;
        tmp1 *= maskinfo.dim[0].extent;
        section.dim[0].mult = tmp1;
        section.dim[0].extent = maskinfo.dim[1].extent;
        if (section.dim[0].extent < 0) section.dim[0].extent = 0;
        section.offset -= section.dim[0].mult;
        section.dim[0].lower = 1;
        tmp1 *= maskinfo.dim[1].extent;
        section.addr += tmp1 * (jd - 1);
        tmp2 = section.dim[0].extent;
        ptmp2 = section.addr;
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++)
        {
          *((int *) ptmp2) = 0;
          ptmp2 += section.dim[0].mult;
        }
        break;
      case 10:

        tmp1 = 1;
        ptmp1 = mask;
        tmp2 = maskinfo.dim[0].extent;
        if (tmp2 < 0) tmp2 = 0;
        tmp1 *= maskinfo.dim[0].extent;
        tmp1 *= maskinfo.dim[1].extent;
        ptmp1 += tmp1 * (jd - 1);
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++) *ptmp1++ = 0;

        tmp1 = 1;
        ptmp1 = mask;
        tmp2 = maskinfo.dim[0].extent;
        if (tmp2 < 0) tmp2 = 0;
        tmp1 *= maskinfo.dim[0].extent;
        ptmp1 += tmp1 * ni;
        tmp1 *= maskinfo.dim[1].extent;
        ptmp1 += tmp1 * (jd - 1);
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++) *ptmp1++ = 0;

        tmp1 = 4;
        section.addr = (char *) mask;
        section.offset = 0;
        tmp1 *= maskinfo.dim[0].extent;
        section.dim[0].mult = tmp1;
        section.dim[0].extent = maskinfo.dim[1].extent;
        if (section.dim[0].extent < 0) section.dim[0].extent = 0;
        section.offset -= section.dim[0].mult;
        section.dim[0].lower = 1;
        tmp1 *= maskinfo.dim[1].extent;
        section.addr += tmp1 * (jd - 1);
        tmp2 = section.dim[0].extent;
        ptmp2 = section.addr;
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++)
        {
          *((int *) ptmp2) = 0;
          ptmp2 += section.dim[0].mult;
        }

        tmp1 = 4;
        section.addr = (char *) mask;
        section.offset = 0;
        section.addr += tmp1 * ni;
        tmp1 *= maskinfo.dim[0].extent;
        section.dim[0].mult = tmp1;
        section.dim[0].extent = maskinfo.dim[1].extent;
        if (section.dim[0].extent < 0) section.dim[0].extent = 0;
        section.offset -= section.dim[0].mult;
        section.dim[0].lower = 1;
        tmp1 *= maskinfo.dim[1].extent;
        section.addr += tmp1 * (jd - 1);
        tmp2 = section.dim[0].extent;
        ptmp2 = section.addr;
        for (int tmp6 = 0; tmp6 < tmp2; tmp6++)
        {
          *((int *) ptmp2) = 0;
          ptmp2 += section.dim[0].mult;
        }
        break;
    }
  }

  return;
}

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

template <typename T>
void
gme_grid_restore(T *p, int ni, int nd)
{
  struct array pinfo;

  pinfo.offset = 0;
  pinfo.dim[0].lower = 0;
  int tmp1 = ni + 1;
  if (tmp1 < 0) tmp1 = 0;
  pinfo.dim[0].extent = tmp1;
  pinfo.dim[0].mult = 1;
  pinfo.offset -= 0;
  int tmp2 = tmp1;
  pinfo.dim[1].lower = 1;
  tmp1 = ni + 1;
  if (tmp1 < 0) tmp1 = 0;
  pinfo.dim[1].extent = tmp1;
  pinfo.dim[1].mult = tmp2;
  pinfo.offset -= pinfo.dim[1].mult;
  tmp2 *= tmp1;
  pinfo.dim[2].lower = 1;
  tmp1 = nd;
  if (tmp1 < 0) tmp1 = 0;
  pinfo.dim[2].extent = tmp1;
  pinfo.dim[2].mult = tmp2;
  pinfo.offset -= pinfo.dim[2].mult;
  int tmp4 = pinfo.dim[1].mult;
  int tmp5 = pinfo.dim[2].mult;
  int tmp3 = pinfo.offset;

  for (int jd = 1; jd <= 10; jd++)
  {
    switch (jd)
    {
      case 1: break;
      case 2:
      case 3:
      case 4:
        for (int j = 0; j <= ni; ++j) p[j + tmp4 + tmp5 * jd + tmp3] = p[tmp4 * (j + 1) + tmp5 * (jd - 1) + tmp3];
        break;
      case 5:
        for (int j = 0; j <= ni; ++j) p[j + tmp4 + tmp5 * jd + tmp3] = p[tmp4 * (j + 1) + tmp5 * (jd - 1) + tmp3];
        for (int j = 0; j <= ni; ++j) p[tmp4 * (j + 1) + tmp5 * 5 + tmp3] = p[j + tmp4 + tmp5 + tmp3];
        break;
      case 6:
        for (int j = 0; j <= ni; ++j) p[j + tmp4 * (ni + 1) + tmp5 * 6 + tmp3] = p[ni + tmp4 * (ni + 1 - j) + tmp5 * 2 + tmp3];
        for (int j = 0; j <= ni; ++j) p[ni + tmp4 * (j + 1) + tmp5 * 6 + tmp3] = p[ni - j + tmp4 * (ni + 1) + tmp5 + tmp3];
        break;
      case 7:
      case 8:
      case 9:
        for (int j = 0; j <= ni; ++j)
          p[j + tmp4 * (ni + 1) + tmp5 * jd + tmp3] = p[ni + tmp4 * (ni + 1 - j) + tmp5 * (jd - 4) + tmp3];
        for (int j = 0; j <= ni; ++j)
          p[ni + tmp4 * (j + 1) + tmp5 * jd + tmp3] = p[ni - j + tmp4 * (ni + 1) + tmp5 * (jd - 5) + tmp3];
        for (int j = 0; j <= ni; ++j) p[j + tmp4 + tmp5 * jd + tmp3] = p[tmp4 * (j + 1) + tmp5 * (jd - 1) + tmp3];
        break;
      case 10:
        for (int j = 0; j <= ni; ++j) p[j + tmp4 + tmp5 * 10 + tmp3] = p[tmp4 * (j + 1) + tmp5 * 9 + tmp3];
        for (int j = 0; j <= ni; ++j) p[tmp4 * (j + 1) + tmp5 * 10 + tmp3] = p[j + tmp4 + tmp5 * 6 + tmp3];
        for (int j = 0; j <= ni; ++j) p[j + tmp4 * (ni + 1) + tmp5 * 10 + tmp3] = p[ni + tmp4 * (ni + 1 - j) + tmp5 + tmp3];
        for (int j = 0; j <= ni; ++j) p[ni + tmp4 * (j + 1) + tmp5 * 10 + tmp3] = p[ni - j + tmp4 * (ni + 1) + tmp5 * 5 + tmp3];
        break;
    }
  }

  return;
}

// Explicit instantiation
template void gme_grid_restore(float *p, int ni, int nd);
template void gme_grid_restore(double *p, int ni, int nd);

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

void
gme_grid(int withBounds, size_t gridsize, double *rlon, double *rlat, double *blon, double *blat, int *imask, int ni, int nd,
         int ni2, int ni3)
{
  // check gridsize
  if ((size_t) (ni + 1) * (ni + 1) * nd != gridsize)
  {
    std::fprintf(stderr, "gme_grid: Calculation of the global GME grid failed (ni=%d)!\n", ni);
    if ((size_t) (ni + 1) * (ni + 1) * nd > gridsize)
    {
      std::fprintf(stderr, "gme_grid: Resulting grid size is greater than the predetermined grid size of %zu.\n", gridsize);
      std::fprintf(stderr, "gme_grid: Maybe this is only a part of a global GME grid without further information.\n");
    }
    std::exit(-1);
  }

  std::vector<double> xn(gridsize * 3, 0.0);
  std::vector<double> rlonx((ni + 3) * (ni + 3) * nd);
  std::vector<double> rlatx((ni + 3) * (ni + 3) * nd);

  int im1s = 0;
  int im1e = ni;
  int im2s = 1;
  int im2e = ni + 1;

  glo_coor(xn.data(), rlon, rlat, im1s, im1e, im2s, im2e, nd, ni2, ni3);

  // check coordinates
  size_t inull = 0;
  for (size_t i = 0; i < gridsize; ++i)
  {
    if ((std::abs(xn[i * 3 + 0]) <= 0 || std::isnan(xn[i * 3 + 0])) && (std::abs(xn[i * 3 + 1]) <= 0 || std::isnan(xn[i * 3 + 1]))
        && (std::abs(xn[i * 3 + 2]) <= 0 || std::isnan(xn[i * 3 + 2])))
      inull++;
  }
  if (inull > gridsize / 4)
  {
    std::fprintf(stderr, "gme_grid: Coordinates calculation of the global GME grid failed (ni=%d)!\n", ni);
    std::exit(-1);
  }

  xd(rlon, im1s, im1e, im2s, im2e, nd, rlonx.data(), im1s - 1, im1e + 1, im2s - 1, im2e + 1, nd);
  xd(rlat, im1s, im1e, im2s, im2e, nd, rlatx.data(), im1s - 1, im1e + 1, im2s - 1, im2e + 1, nd);

  initmask(imask, ni, nd);

  if (withBounds)
  {
    std::vector<struct polygon> poly((ni + 1) * (ni + 1) * nd);

    neighbours(rlonx.data(), rlatx.data(), im1s - 1, im1e + 1, im2s - 1, im2e + 1, nd, poly.data(), im1s, im1e, im2s, im2e, nd);

    boundary(poly.data(), im1s, im1e, im2s, im2e, nd);

    for (size_t i = 0; i < gridsize; ++i)
    {
      for (int j = 0; j < poly[i].type; ++j)
      {
        blon[i * 6 + j] = poly[i].boundary[j].lon;
        blat[i * 6 + j] = poly[i].boundary[j].lat;
      }
      if (poly[i].type == pentagon)
      {
        blon[i * 6 + 5] = blon[i * 6 + 4];
        blat[i * 6 + 5] = blat[i * 6 + 4];
      }
    }
  }
}

#ifdef TEST_GME_GRID
int
main(int argc, char *argv[])
{
  int ni2, ni3;
  int im1s, im1e, im2s, im2e;

  int nd = 10;
  int ni = 2;

  gme_factorni(ni, &ni2, &ni3);

  std::vector<struct polygon> poly((ni + 1) * (ni + 1) * nd);
  std::vector<double> xn((ni + 1) * (ni + 1) * 3 * nd);
  std::vector<double> rlon((ni + 1) * (ni + 1) * nd);
  std::vector<double> rlat((ni + 1) * (ni + 1) * nd);
  std::vector<double> rlonx((ni + 3) * (ni + 3) * nd);
  std::vector<double> rlatx((ni + 3) * (ni + 3) * nd);
  std::vector<int> mask((ni + 1) * (ni + 1) * nd);
  std::vector<double> area((ni + 1) * (ni + 1) * nd);

  im1s = 0;
  im1e = ni;
  im2s = 1;
  im2e = ni + 1;

  glo_coor(xn.data(), rlon.data(), rlat.data(), im1s, im1e, im2s, im2e, nd, ni2, ni3);

  xd(rlon.data(), im1s, im1e, im2s, im2e, nd, rlonx.data(), im1s - 1, im1e + 1, im2s - 1, im2e + 1, nd);
  xd(rlat.data(), im1s, im1e, im2s, im2e, nd, rlatx.data(), im1s - 1, im1e + 1, im2s - 1, im2e + 1, nd);

  initmask(mask.data(), ni, nd);

  {
    int id1 = ni + 1;
    int id2 = id1 * (ni + 1);
    int ioffset = -(id1 + id2);

    auto out = std::fopen("mask.dat", "w");
    if (out == nullptr)
    {
      std::perror("couldn't open mask.dat");
      std::exit(-1);
    }

    for (jd = 1; jd <= nd; jd++)
    {
      std::fprintf(out, "%d-------------------------------------------------\n", jd);
      for (j2 = 1; j2 <= ni + 1; ++j2)
      {
        for (j1 = 0; j1 <= ni; ++j1) { std::fprintf(out, "%8d", mask[j1 + id1 * j2 + id2 * jd + ioffset]); }
        std::fprintf(out, "\n");
      }
    }

    std::fclose(out);
  }

  neighbours(rlonx.data(), rlatx.data(), im1s - 1, im1e + 1, im2s - 1, im2e + 1, nd, poly.data(), im1s, im1e, im2s, im2e, nd);

  boundary(poly.data(), im1s, im1e, im2s, im2e, nd);

  {
    int jm;

    int id1 = ni + 1;
    int id2 = id1 * (ni + 1);
    int ioffset = -(id1 + id2);

    auto out = std::fopen("dual.dat", "w");
    if (out == nullptr)
    {
      std::perror("couldn't open dual.dat");
      std::exit(-1);
    }

    for (int jd = 1; jd <= nd; jd++)
    {
      for (int j2 = 1; j2 <= ni + 1; ++j2)
      {
        for (int j1 = 0; j1 <= ni; ++j1)
        {
          if (mask[j1 + id1 * j2 + id2 * jd + ioffset])
          {
            std::fprintf(out, ">\n");
            for (jm = 1; jm <= poly[j1 + id1 * j2 + id2 * jd + ioffset].type; jm++)
            {
              std::fprintf(out, "%8.2f%8.2f\n", pid180 * poly[j1 + id1 * j2 + id2 * jd + ioffset].boundary[jm - 1].lon,
                           pid180 * poly[j1 + id1 * j2 + id2 * jd + ioffset].boundary[jm - 1].lat);
            }
          }
        }
      }
    }
    std::fclose(out);
  }

  {
    struct geo p1, p2, p3;
    struct cart c1, c2, c3;
    int jm, jl;

    int id1 = ni + 1;
    int id2 = id1 * (ni + 1);
    int ioffset = -(id1 + id2);

    double total_area = 0.0;

    for (int jd = 1; jd <= nd; jd++)
    {
      for (int j2 = 1; j2 <= ni + 1; ++j2)
      {
        for (int j1 = 0; j1 <= ni; ++j1)
        {
          area[j1 + id1 * j2 + id2 * jd + ioffset] = 0.0;
          if (mask[j1 + id1 * j2 + id2 * jd + ioffset])
          {
            p3.lon = poly[j1 + id1 * j2 + id2 * jd + ioffset].center.lon;
            p3.lat = poly[j1 + id1 * j2 + id2 * jd + ioffset].center.lat;
            c3 = gc2cc(&p3);
            for (jm = 1; jm <= poly[j1 + id1 * j2 + id2 * jd + ioffset].type; jm++)
            {
              jl = jm - 1;
              if (jm == poly[j1 + id1 * j2 + id2 * jd + ioffset].type)
              {
                p1.lon = poly[j1 + id1 * j2 + id2 * jd + ioffset].boundary[0].lon;
                p1.lat = poly[j1 + id1 * j2 + id2 * jd + ioffset].boundary[0].lat;
                p2.lon = poly[j1 + id1 * j2 + id2 * jd + ioffset].boundary[jl].lon;
                p2.lat = poly[j1 + id1 * j2 + id2 * jd + ioffset].boundary[jl].lat;
                c1 = gc2cc(&p1);
                c2 = gc2cc(&p2);
              }
              else
              {
                p1.lon = poly[j1 + id1 * j2 + id2 * jd + ioffset].boundary[jl].lon;
                p1.lat = poly[j1 + id1 * j2 + id2 * jd + ioffset].boundary[jl].lat;
                p2.lon = poly[j1 + id1 * j2 + id2 * jd + ioffset].boundary[jl + 1].lon;
                p2.lat = poly[j1 + id1 * j2 + id2 * jd + ioffset].boundary[jl + 1].lat;
                c1 = gc2cc(&p1);
                c2 = gc2cc(&p2);
              }
              area[j1 + id1 * j2 + id2 * jd + ioffset] = area[j1 + id1 * j2 + id2 * jd + ioffset] + areas(&c1, &c2, &c3);
            }
            total_area = total_area + area[j1 + id1 * j2 + id2 * jd + ioffset];
          }
        }
      }
    }
  }

  return 0;
}
#endif
