PostGIS  2.3.8dev-r@@SVN_REVISION@@

◆ lwgeom_make_valid()

LWGEOM* lwgeom_make_valid ( LWGEOM geom)

Attempts to make an invalid geometries valid w/out losing points.

NOTE: this is only available when liblwgeom is built against GEOS 3.3.0 or higher

Definition at line 979 of file liblwgeom/lwgeom_geos_clean.c.

References LWGEOM::bbox, LWGEOM::flags, FLAGS_GET_Z, GEOS2LWGEOM(), lwalloc(), lwcollection_construct(), LWDEBUG, LWDEBUGF, lwerror(), LWGEOM2GEOS(), lwgeom_geos_errmsg, lwgeom_geos_error(), LWGEOM_GEOS_makeValid(), lwgeom_is_collection(), lwgeom_make_geos_friendly(), MULTITYPE, LWGEOM::srid, and LWGEOM::type.

Referenced by _lwt_AddLineEdge(), _lwt_EdgeMotionArea(), lwgeom_clean(), rt_raster_gdal_polygonize(), rt_raster_surface(), ST_MakeValid(), and test_lwgeom_make_valid().

980 {
981  int is3d;
982  GEOSGeom geosgeom;
983  GEOSGeometry* geosout;
984  LWGEOM *lwgeom_out;
985 
986  is3d = FLAGS_GET_Z(lwgeom_in->flags);
987 
988  /*
989  * Step 1 : try to convert to GEOS, if impossible, clean that up first
990  * otherwise (adding only duplicates of existing points)
991  */
992 
994 
995  lwgeom_out = lwgeom_in;
996  geosgeom = LWGEOM2GEOS(lwgeom_out, 0);
997  if ( ! geosgeom )
998  {
999  LWDEBUGF(4,
1000  "Original geom can't be converted to GEOS (%s)"
1001  " - will try cleaning that up first",
1003 
1004 
1005  lwgeom_out = lwgeom_make_geos_friendly(lwgeom_out);
1006  if ( ! lwgeom_out )
1007  {
1008  lwerror("Could not make a valid geometry out of input");
1009  }
1010 
1011  /* try again as we did cleanup now */
1012  /* TODO: invoke LWGEOM2GEOS directly with autoclean ? */
1013  geosgeom = LWGEOM2GEOS(lwgeom_out, 0);
1014  if ( ! geosgeom )
1015  {
1016  lwerror("Couldn't convert POSTGIS geom to GEOS: %s",
1018  return NULL;
1019  }
1020 
1021  }
1022  else
1023  {
1024  LWDEBUG(4, "original geom converted to GEOS");
1025  lwgeom_out = lwgeom_in;
1026  }
1027 
1028  geosout = LWGEOM_GEOS_makeValid(geosgeom);
1029  GEOSGeom_destroy(geosgeom);
1030  if ( ! geosout )
1031  {
1032  return NULL;
1033  }
1034 
1035  lwgeom_out = GEOS2LWGEOM(geosout, is3d);
1036  GEOSGeom_destroy(geosout);
1037 
1038  if ( lwgeom_is_collection(lwgeom_in) && ! lwgeom_is_collection(lwgeom_out) )
1039  {{
1040  LWGEOM **ogeoms = lwalloc(sizeof(LWGEOM*));
1041  LWGEOM *ogeom;
1042  LWDEBUG(3, "lwgeom_make_valid: forcing multi");
1043  /* NOTE: this is safe because lwgeom_out is surely not lwgeom_in or
1044  * otherwise we couldn't have a collection and a non-collection */
1045  assert(lwgeom_in != lwgeom_out);
1046  ogeoms[0] = lwgeom_out;
1047  ogeom = (LWGEOM *)lwcollection_construct(MULTITYPE[lwgeom_out->type],
1048  lwgeom_out->srid, lwgeom_out->bbox, 1, ogeoms);
1049  lwgeom_out->bbox = NULL;
1050  lwgeom_out = ogeom;
1051  }}
1052 
1053  lwgeom_out->srid = lwgeom_in->srid;
1054  return lwgeom_out;
1055 }
GBOX * bbox
Definition: liblwgeom.h:397
int lwgeom_is_collection(const LWGEOM *lwgeom)
Determine whether a LWGEOM can contain sub-geometries or not.
Definition: lwgeom.c:1004
static LWGEOM * lwgeom_make_geos_friendly(LWGEOM *geom)
LWCOLLECTION * lwcollection_construct(uint8_t type, int srid, GBOX *bbox, uint32_t ngeoms, LWGEOM **geoms)
Definition: lwcollection.c:43
uint8_t flags
Definition: liblwgeom.h:396
char lwgeom_geos_errmsg[LWGEOM_GEOS_ERRMSG_MAXSIZE]
#define LWDEBUG(level, msg)
Definition: lwgeom_log.h:83
static GEOSGeometry * LWGEOM_GEOS_makeValid(const GEOSGeometry *)
int32_t srid
Definition: liblwgeom.h:398
void lwgeom_geos_error(const char *fmt,...)
#define FLAGS_GET_Z(flags)
Macros for manipulating the 'flags' byte.
Definition: liblwgeom.h:139
GEOSGeometry * LWGEOM2GEOS(const LWGEOM *lwgeom, int autofix)
uint8_t MULTITYPE[NUMTYPES]
Look-up for the correct MULTI* type promotion for singleton types.
Definition: lwgeom.c:277
LWGEOM * GEOS2LWGEOM(const GEOSGeometry *geom, char want3d)
uint8_t type
Definition: liblwgeom.h:395
void * lwalloc(size_t size)
Definition: lwutil.c:227
#define LWDEBUGF(level, msg,...)
Definition: lwgeom_log.h:88
void lwerror(const char *fmt,...)
Write a notice out to the error handler.
Definition: lwutil.c:102
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