PostGIS  2.2.8dev-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 993 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().

994 {
995  int is3d;
996  GEOSGeom geosgeom;
997  GEOSGeometry* geosout;
998  LWGEOM *lwgeom_out;
999 
1000  is3d = FLAGS_GET_Z(lwgeom_in->flags);
1001 
1002  /*
1003  * Step 1 : try to convert to GEOS, if impossible, clean that up first
1004  * otherwise (adding only duplicates of existing points)
1005  */
1006 
1008 
1009  lwgeom_out = lwgeom_in;
1010  geosgeom = LWGEOM2GEOS(lwgeom_out, 0);
1011  if ( ! geosgeom )
1012  {
1013  LWDEBUGF(4,
1014  "Original geom can't be converted to GEOS (%s)"
1015  " - will try cleaning that up first",
1017 
1018 
1019  lwgeom_out = lwgeom_make_geos_friendly(lwgeom_out);
1020  if ( ! lwgeom_out )
1021  {
1022  lwerror("Could not make a valid geometry out of input");
1023  }
1024 
1025  /* try again as we did cleanup now */
1026  /* TODO: invoke LWGEOM2GEOS directly with autoclean ? */
1027  geosgeom = LWGEOM2GEOS(lwgeom_out, 0);
1028  if ( ! geosgeom )
1029  {
1030  lwerror("Couldn't convert POSTGIS geom to GEOS: %s",
1032  return NULL;
1033  }
1034 
1035  }
1036  else
1037  {
1038  LWDEBUG(4, "original geom converted to GEOS");
1039  lwgeom_out = lwgeom_in;
1040  }
1041 
1042  geosout = LWGEOM_GEOS_makeValid(geosgeom);
1043  GEOSGeom_destroy(geosgeom);
1044  if ( ! geosout )
1045  {
1046  return NULL;
1047  }
1048 
1049  lwgeom_out = GEOS2LWGEOM(geosout, is3d);
1050  GEOSGeom_destroy(geosout);
1051 
1052  if ( lwgeom_is_collection(lwgeom_in) && ! lwgeom_is_collection(lwgeom_out) )
1053  {{
1054  LWGEOM **ogeoms = lwalloc(sizeof(LWGEOM*));
1055  LWGEOM *ogeom;
1056  LWDEBUG(3, "lwgeom_make_valid: forcing multi");
1057  /* NOTE: this is safe because lwgeom_out is surely not lwgeom_in or
1058  * otherwise we couldn't have a collection and a non-collection */
1059  assert(lwgeom_in != lwgeom_out);
1060  ogeoms[0] = lwgeom_out;
1061  ogeom = (LWGEOM *)lwcollection_construct(MULTITYPE[lwgeom_out->type],
1062  lwgeom_out->srid, lwgeom_out->bbox, 1, ogeoms);
1063  lwgeom_out->bbox = NULL;
1064  lwgeom_out = ogeom;
1065  }}
1066 
1067  lwgeom_out->srid = lwgeom_in->srid;
1068  return lwgeom_out;
1069 }
GBOX * bbox
Definition: liblwgeom.h:382
int lwgeom_is_collection(const LWGEOM *lwgeom)
Determine whether a LWGEOM can contain sub-geometries or not.
Definition: lwgeom.c:991
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:30
uint8_t flags
Definition: liblwgeom.h:381
char lwgeom_geos_errmsg[LWGEOM_GEOS_ERRMSG_MAXSIZE]
#define LWDEBUG(level, msg)
Definition: lwgeom_log.h:50
static GEOSGeometry * LWGEOM_GEOS_makeValid(const GEOSGeometry *)
int32_t srid
Definition: liblwgeom.h:383
void lwgeom_geos_error(const char *fmt,...)
#define FLAGS_GET_Z(flags)
Macros for manipulating the 'flags' byte.
Definition: liblwgeom.h:124
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:264
LWGEOM * GEOS2LWGEOM(const GEOSGeometry *geom, char want3d)
uint8_t type
Definition: liblwgeom.h:380
void * lwalloc(size_t size)
Definition: lwutil.c:199
#define LWDEBUGF(level, msg,...)
Definition: lwgeom_log.h:55
void lwerror(const char *fmt,...)
Write a notice out to the error handler.
Definition: lwutil.c:74
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