text: /*
   * Copyright 2005-2016 ECMWF.
   *
   * This software is licensed under the terms of the Apache Licence Version 2.0
   * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
   *
   * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
   * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
   */
  
  /*************************************************
   * Enrico Fucile
   ***********************************************/
  
  #include "grib_api_internal.h"
  #include <math.h>
  /*
     This is used by make_class.pl
  
     START_CLASS_DEF
     CLASS      = accessor
     SUPER      = grib_accessor_class_long
     IMPLEMENTS = unpack_long
     IMPLEMENTS = init
     IMPLEMENTS = pack_long
     MEMBERS=const char*                  N
     MEMBERS=const char*                  Ni
     MEMBERS=const char*                  plpresent
     MEMBERS=const char*                  pl
     END_CLASS_DEF
  
   */
  
  /* START_CLASS_IMP */
  
  /*
  
  Don't edit anything between START_CLASS_IMP and END_CLASS_IMP
  Instead edit values between START_CLASS_DEF and END_CLASS_DEF
  or edit "accessor.class" and rerun ./make_class.pl
  
  */
  
  static int pack_long(grib_accessor*, const long* val,size_t *len);
  static int unpack_long(grib_accessor*, long* val,size_t *len);
  static void init(grib_accessor*,const long, grib_arguments* );
  static void init_class(grib_accessor_class*);
  
  typedef struct grib_accessor_octahedral_gaussian {
      grib_accessor          att;
  /* Members defined in gen */
  /* Members defined in long */
  /* Members defined in octahedral_gaussian */
  	const char*                  N;
  	const char*                  Ni;
  	const char*                  plpresent;
  	const char*                  pl;
  } grib_accessor_octahedral_gaussian;
  
  extern grib_accessor_class* grib_accessor_class_long;
  
  static grib_accessor_class _grib_accessor_class_octahedral_gaussian = {
      &grib_accessor_class_long,                      /* super                     */
      "octahedral_gaussian",                      /* name                      */
      sizeof(grib_accessor_octahedral_gaussian),  /* size                      */
      0,                           /* inited */
      &init_class,                 /* init_class */
      &init,                       /* init                      */
      0,                  /* post_init                      */
      0,                    /* free mem                       */
      0,                       /* describes himself         */
      0,                /* get length of section     */
      0,              /* get length of string      */
      0,                /* get number of values      */
      0,                 /* get number of bytes      */
      0,                /* get offset to bytes           */
      0,            /* get native type               */
      0,                /* get sub_section                */
      0,               /* grib_pack procedures long      */
      0,                 /* grib_pack procedures long      */
      &pack_long,                  /* grib_pack procedures long      */
      &unpack_long,                /* grib_unpack procedures long    */
      0,                /* grib_pack procedures double    */
      0,              /* grib_unpack procedures double  */
      0,                /* grib_pack procedures string    */
      0,              /* grib_unpack procedures string  */
      0,          /* grib_pack array procedures string    */
      0,        /* grib_unpack array procedures string  */
      0,                 /* grib_pack procedures bytes     */
      0,               /* grib_unpack procedures bytes   */
      0,            /* pack_expression */
      0,              /* notify_change   */
      0,                /* update_size   */
      0,            /* preferred_size   */
      0,                    /* resize   */
      0,      /* nearest_smaller_value */
      0,                       /* next accessor    */
      0,                    /* compare vs. another accessor   */
      0,     /* unpack only ith value          */
      0,     /* unpack a subarray         */
      0,              		/* clear          */
      0,               		/* clone accessor          */
  };
  
  
  grib_accessor_class* grib_accessor_class_octahedral_gaussian = &_grib_accessor_class_octahedral_gaussian;
  
  
  static void init_class(grib_accessor_class* c)
  {
  	c->dump	=	(*(c->super))->dump;
  	c->next_offset	=	(*(c->super))->next_offset;
  	c->string_length	=	(*(c->super))->string_length;
  	c->value_count	=	(*(c->super))->value_count;
  	c->byte_count	=	(*(c->super))->byte_count;
  	c->byte_offset	=	(*(c->super))->byte_offset;
  	c->get_native_type	=	(*(c->super))->get_native_type;
  	c->sub_section	=	(*(c->super))->sub_section;
  	c->pack_missing	=	(*(c->super))->pack_missing;
  	c->is_missing	=	(*(c->super))->is_missing;
  	c->pack_double	=	(*(c->super))->pack_double;
  	c->unpack_double	=	(*(c->super))->unpack_double;
  	c->pack_string	=	(*(c->super))->pack_string;
  	c->unpack_string	=	(*(c->super))->unpack_string;
  	c->pack_string_array	=	(*(c->super))->pack_string_array;
  	c->unpack_string_array	=	(*(c->super))->unpack_string_array;
  	c->pack_bytes	=	(*(c->super))->pack_bytes;
  	c->unpack_bytes	=	(*(c->super))->unpack_bytes;
  	c->pack_expression	=	(*(c->super))->pack_expression;
  	c->notify_change	=	(*(c->super))->notify_change;
  	c->update_size	=	(*(c->super))->update_size;
  	c->preferred_size	=	(*(c->super))->preferred_size;
  	c->resize	=	(*(c->super))->resize;
  	c->nearest_smaller_value	=	(*(c->super))->nearest_smaller_value;
  	c->next	=	(*(c->super))->next;
  	c->compare	=	(*(c->super))->compare;
  	c->unpack_double_element	=	(*(c->super))->unpack_double_element;
  	c->unpack_double_subarray	=	(*(c->super))->unpack_double_subarray;
  	c->clear	=	(*(c->super))->clear;
  	c->make_clone	=	(*(c->super))->make_clone;
  }
  
  /* END_CLASS_IMP */
  
  static void init(grib_accessor* a,const long l, grib_arguments* c)
  {
      grib_accessor_octahedral_gaussian* self = (grib_accessor_octahedral_gaussian*)a;
      int n = 0;
  
      self->N            = grib_arguments_get_name(grib_handle_of_accessor(a),c,n++);
      self->Ni           = grib_arguments_get_name(grib_handle_of_accessor(a),c,n++);
      self->plpresent    = grib_arguments_get_name(grib_handle_of_accessor(a),c,n++);
      self->pl           = grib_arguments_get_name(grib_handle_of_accessor(a),c,n++);
  }
  
  /* For an Octahedral grid, this is the number of points on the top-most latitude (near pole) */
  #define NUM_POINTS_ON_LAT_NEAR_POLE 20
  
  static int unpack_long(grib_accessor* a, long* val, size_t *len)
  {
      grib_accessor_octahedral_gaussian* self = (grib_accessor_octahedral_gaussian*)a;
      int ret = GRIB_SUCCESS;
      long N,Ni;
      long plpresent=0;
      long* pl=NULL; /* pl array */
      size_t plsize=0, i=0, mid=0;
  
      grib_context* c=a->context;
  
      if((ret = grib_get_long_internal(grib_handle_of_accessor(a), self->N,&N)) != GRIB_SUCCESS)
          return ret;
  
      if((ret = grib_get_long_internal(grib_handle_of_accessor(a), self->Ni,&Ni)) != GRIB_SUCCESS)
          return ret;
  
      /* If Ni is not missing, then this is a plain gaussian grid and not reduced. */
      /* So it cannot be an octahedral grid */
      if (Ni != GRIB_MISSING_LONG) {
          *val=0;
          return GRIB_SUCCESS;
      }
  
      if((ret = grib_get_long_internal(grib_handle_of_accessor(a), self->plpresent,&plpresent)) != GRIB_SUCCESS)
          return ret;
      if (!plpresent) {
          *val = 0; /* Not octahedral */
          return GRIB_SUCCESS;
      }
  
      if((ret = grib_get_size(grib_handle_of_accessor(a),self->pl,&plsize)) != GRIB_SUCCESS)
          return ret;
      Assert(plsize);
      if (plsize != 2*N) {
          *val=0; /* Not octahedral */
          return GRIB_SUCCESS;
      }
      pl=(long*)grib_context_malloc_clear(c,sizeof(long)*plsize);
      if (!pl) {
          return GRIB_OUT_OF_MEMORY;
      }
      if ((ret = grib_get_long_array_internal(grib_handle_of_accessor(a),self->pl,pl, &plsize)) != GRIB_SUCCESS)
          return ret;
      if (pl[0] != NUM_POINTS_ON_LAT_NEAR_POLE) {
          *val=0; /* Not octahedral */
          grib_context_free(c, pl);
          return GRIB_SUCCESS;
      }
      mid = plsize/2;
      /* Check pl values and symmetry */
      for(i=0; i<mid; ++i) {
          const long expected = 4*(i+1) + 16; /* Octahedral rule */
          if ( pl[i] != expected || (pl[i] != pl[plsize-1-i]) ) {
              *val = 0; /* Not octahedral */
              grib_context_free(c, pl);
              return GRIB_SUCCESS;
          }
      }
      grib_context_free(c, pl);
  
      *val=1;  /* It is Octahedral */
      return ret;
  }
  
  static int pack_long(grib_accessor* a, const long* val, size_t *len)
  {
      return GRIB_NOT_IMPLEMENTED;
  }
  