PostGIS  2.5.0dev-r@@SVN_REVISION@@

◆ cluster_within_distance_garray()

Datum cluster_within_distance_garray ( PG_FUNCTION_ARGS  )

Definition at line 3148 of file postgis/lwgeom_geos.c.

References ARRAY2LWGEOM(), array_nelems_not_null(), cluster_within_distance(), gserialized_from_lwgeom(), linemerge(), LW_SUCCESS, lwgeom_free(), lwgeom_geos_error(), PG_FUNCTION_INFO_V1(), and SRID_UNKNOWN.

Referenced by clusterintersecting_garray(), and pgis_geometry_clusterwithin_finalfn().

3149 {
3150  Datum* result_array_data;
3151  ArrayType *array, *result;
3152  int is3d = 0;
3153  uint32 nelems, nclusters, i;
3154  LWGEOM** lw_inputs;
3155  LWGEOM** lw_results;
3156  double tolerance;
3157  int srid=SRID_UNKNOWN;
3158 
3159  /* Parameters used to construct a result array */
3160  int16 elmlen;
3161  bool elmbyval;
3162  char elmalign;
3163 
3164  /* Null array, null geometry (should be empty?) */
3165  if (PG_ARGISNULL(0))
3166  PG_RETURN_NULL();
3167 
3168  array = PG_GETARG_ARRAYTYPE_P(0);
3169 
3170  tolerance = PG_GETARG_FLOAT8(1);
3171  if (tolerance < 0)
3172  {
3173  lwpgerror("Tolerance must be a positive number.");
3174  PG_RETURN_NULL();
3175  }
3176 
3177  nelems = array_nelems_not_null(array);
3178 
3179  POSTGIS_DEBUGF(3, "cluster_within_distance_garray: number of non-null elements: %d", nelems);
3180 
3181  if ( nelems == 0 ) PG_RETURN_NULL();
3182 
3183  /* TODO short-circuit for one element? */
3184 
3185  /* Ok, we really need geos now ;) */
3186  initGEOS(lwpgnotice, lwgeom_geos_error);
3187 
3188  lw_inputs = ARRAY2LWGEOM(array, nelems, &is3d, &srid);
3189  if (!lw_inputs)
3190  {
3191  PG_RETURN_NULL();
3192  }
3193 
3194  if (cluster_within_distance(lw_inputs, nelems, tolerance, &lw_results, &nclusters) != LW_SUCCESS)
3195  {
3196  elog(ERROR, "cluster_within: Error performing clustering");
3197  PG_RETURN_NULL();
3198  }
3199  pfree(lw_inputs); /* don't need to destroy items because GeometryCollections have taken ownership */
3200 
3201  if (!lw_results) PG_RETURN_NULL();
3202 
3203  result_array_data = palloc(nclusters * sizeof(Datum));
3204  for (i=0; i<nclusters; ++i)
3205  {
3206  result_array_data[i] = PointerGetDatum(gserialized_from_lwgeom(lw_results[i], NULL));
3207  lwgeom_free(lw_results[i]);
3208  }
3209  pfree(lw_results);
3210 
3211  get_typlenbyvalalign(array->elemtype, &elmlen, &elmbyval, &elmalign);
3212  result = construct_array(result_array_data, nclusters, array->elemtype, elmlen, elmbyval, elmalign);
3213 
3214  if (!result)
3215  {
3216  elog(ERROR, "clusterwithin: Error constructing return-array");
3217  PG_RETURN_NULL();
3218  }
3219 
3220  PG_RETURN_POINTER(result);
3221 }
uint32_t array_nelems_not_null(ArrayType *array)
void lwgeom_free(LWGEOM *geom)
Definition: lwgeom.c:1144
#define LW_SUCCESS
Definition: liblwgeom.h:79
int cluster_within_distance(LWGEOM **geoms, uint32_t num_geoms, double tolerance, LWGEOM ***clusterGeoms, uint32_t *num_clusters)
Takes an array of LWGEOM* and constructs an array of LWGEOM*, where each element in the constructed a...
LWGEOM ** ARRAY2LWGEOM(ArrayType *array, uint32_t nelems, int *is3d, int *srid)
void lwgeom_geos_error(const char *fmt,...)
#define SRID_UNKNOWN
Unknown SRID value.
Definition: liblwgeom.h:187
GSERIALIZED * gserialized_from_lwgeom(LWGEOM *geom, size_t *size)
Allocate a new GSERIALIZED from an LWGEOM.
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