PostGIS  2.2.8dev-r@@SVN_REVISION@@

◆ topologypreservesimplify()

Datum topologypreservesimplify ( PG_FUNCTION_ARGS  )

Definition at line 976 of file postgis/lwgeom_geos.c.

References buffer(), GEOS2POSTGIS(), gserialized_get_srid(), gserialized_has_z(), gserialized_is_empty(), HANDLE_GEOS_ERROR, lwgeom_geos_error(), PG_FUNCTION_INFO_V1(), and POSTGIS2GEOS().

Referenced by convexhull().

977 {
978  GSERIALIZED *geom1;
979  double tolerance;
980  GEOSGeometry *g1, *g3;
981  GSERIALIZED *result;
982 
983  geom1 = PG_GETARG_GSERIALIZED_P(0);
984  tolerance = PG_GETARG_FLOAT8(1);
985 
986  /* Empty.Simplify() == Empty */
987  if ( gserialized_is_empty(geom1) )
988  PG_RETURN_POINTER(geom1);
989 
990  initGEOS(lwpgnotice, lwgeom_geos_error);
991 
992  g1 = (GEOSGeometry *)POSTGIS2GEOS(geom1);
993  if ( 0 == g1 ) /* exception thrown at construction */
994  {
995  HANDLE_GEOS_ERROR("First argument geometry could not be converted to GEOS");
996  PG_RETURN_NULL();
997  }
998 
999  g3 = GEOSTopologyPreserveSimplify(g1,tolerance);
1000  GEOSGeom_destroy(g1);
1001 
1002  if (g3 == NULL)
1003  {
1004  HANDLE_GEOS_ERROR("GEOSTopologyPreserveSimplify");
1005  PG_RETURN_NULL(); /* never get here */
1006  }
1007 
1008  POSTGIS_DEBUGF(3, "result: %s", GEOSGeomToWKT(g3));
1009 
1010  GEOSSetSRID(g3, gserialized_get_srid(geom1));
1011 
1012  result = GEOS2POSTGIS(g3, gserialized_has_z(geom1));
1013  GEOSGeom_destroy(g3);
1014 
1015  if (result == NULL)
1016  {
1017  elog(ERROR,"GEOS topologypreservesimplify() threw an error (result postgis geometry formation)!");
1018  PG_RETURN_NULL(); /* never get here */
1019  }
1020 
1021  PG_FREE_IF_COPY(geom1, 0);
1022  PG_RETURN_POINTER(result);
1023 }
int gserialized_has_z(const GSERIALIZED *gser)
Check if a GSERIALIZED has a Z ordinate.
Definition: g_serialized.c:24
int gserialized_is_empty(const GSERIALIZED *g)
Check if a GSERIALIZED is empty without deserializing first.
Definition: g_serialized.c:139
void lwgeom_geos_error(const char *fmt,...)
GEOSGeometry * POSTGIS2GEOS(GSERIALIZED *pglwgeom)
GSERIALIZED * GEOS2POSTGIS(GEOSGeom geom, char want3d)
#define HANDLE_GEOS_ERROR(label)
int32_t gserialized_get_srid(const GSERIALIZED *s)
Extract the SRID from the serialized form (it is packed into three bytes so this is a handy function)...
Definition: g_serialized.c:69
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