PostGIS  2.2.7dev-r@@SVN_REVISION@@
Datum ST_CollectionExtract ( PG_FUNCTION_ARGS  )

Definition at line 2526 of file lwgeom_functions_basic.c.

References LWGEOM::flags, FLAGS_GET_M, FLAGS_GET_Z, geometry_serialize(), LINETYPE, lwcollection_as_lwgeom(), lwcollection_extract(), lwgeom_construct_empty(), lwgeom_free(), lwgeom_from_gserialized(), lwgeom_is_collection(), lwgeom_is_empty(), POINTTYPE, POLYGONTYPE, LWGEOM::srid, and LWGEOM::type.

2527 {
2528  GSERIALIZED *input = PG_GETARG_GSERIALIZED_P(0);
2529  GSERIALIZED *output;
2530  LWGEOM *lwgeom = lwgeom_from_gserialized(input);
2531  LWGEOM *lwcol = NULL;
2532  int type = PG_GETARG_INT32(1);
2533  int lwgeom_type = lwgeom->type;
2534 
2535  /* Ensure the right type was input */
2536  if ( ! ( type == POINTTYPE || type == LINETYPE || type == POLYGONTYPE ) )
2537  {
2538  lwgeom_free(lwgeom);
2539  elog(ERROR, "ST_CollectionExtract: only point, linestring and polygon may be extracted");
2540  PG_RETURN_NULL();
2541  }
2542 
2543  /* Mirror non-collections right back */
2544  if ( ! lwgeom_is_collection(lwgeom) )
2545  {
2546  /* Non-collections of the matching type go back */
2547  if(lwgeom_type == type)
2548  {
2549  lwgeom_free(lwgeom);
2550  PG_RETURN_POINTER(input);
2551  }
2552  /* Others go back as EMPTY */
2553  else
2554  {
2555  lwcol = lwgeom_construct_empty(type, lwgeom->srid, FLAGS_GET_Z(lwgeom->flags), FLAGS_GET_M(lwgeom->flags));
2556  }
2557  }
2558  else
2559  {
2560  lwcol = lwcollection_as_lwgeom(lwcollection_extract((LWCOLLECTION*)lwgeom, type));
2561  }
2562 
2563 #if 0
2565  {
2566  lwgeom_free(lwgeom);
2567  PG_RETURN_NULL();
2568  }
2569 #endif
2570  output = geometry_serialize((LWGEOM*)lwcol);
2571  lwgeom_free(lwgeom);
2572  lwgeom_free(lwcol);
2573 
2574  PG_RETURN_POINTER(output);
2575 }
#define LINETYPE
Definition: liblwgeom.h:71
int lwgeom_is_collection(const LWGEOM *lwgeom)
Determine whether a LWGEOM can contain sub-geometries or not.
Definition: lwgeom.c:991
LWCOLLECTION * lwcollection_extract(LWCOLLECTION *col, int type)
Takes a potentially heterogeneous collection and returns a homogeneous collection consisting only of ...
Definition: lwcollection.c:353
LWGEOM * lwgeom_from_gserialized(const GSERIALIZED *g)
Allocate a new LWGEOM from a GSERIALIZED.
#define POLYGONTYPE
Definition: liblwgeom.h:72
uint8_t flags
Definition: liblwgeom.h:381
void lwgeom_free(LWGEOM *geom)
Definition: lwgeom.c:1050
int32_t srid
Definition: liblwgeom.h:383
#define FLAGS_GET_Z(flags)
Macros for manipulating the 'flags' byte.
Definition: liblwgeom.h:124
LWGEOM * lwgeom_construct_empty(uint8_t type, int srid, char hasz, char hasm)
Definition: lwgeom.c:1807
GSERIALIZED * geometry_serialize(LWGEOM *lwgeom)
#define POINTTYPE
LWTYPE numbers, used internally by PostGIS.
Definition: liblwgeom.h:70
#define FLAGS_GET_M(flags)
Definition: liblwgeom.h:125
uint8_t type
Definition: liblwgeom.h:380
int lwgeom_is_empty(const LWGEOM *geom)
Return true or false depending on whether a geometry is an "empty" geometry (no vertices members) ...
Definition: lwgeom.c:1297
LWGEOM * lwcollection_as_lwgeom(const LWCOLLECTION *obj)
Definition: lwgeom.c:219

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