PostGIS  2.5.1dev-r@@SVN_REVISION@@

◆ lwgeom_union()

LWGEOM* lwgeom_union ( const LWGEOM geom1,
const LWGEOM geom2 
)

Definition at line 825 of file liblwgeom/lwgeom_geos.c.

References AUTOFIX, LWGEOM::flags, FLAGS_GET_Z, GEOS2LWGEOM(), GEOS_FAIL, GEOS_FREE, GEOS_FREE_AND_FAIL, LWGEOM2GEOS(), lwgeom_clone_deep(), lwgeom_geos_error(), lwgeom_is_empty(), lwnotice(), RESULT_SRID, and SRID_INVALID.

Referenced by _lwt_AddLine(), and geos_geomunion().

826 {
827  LWGEOM* result;
828  int32_t srid = RESULT_SRID(geom1, geom2);
829  uint8_t is3d = (FLAGS_GET_Z(geom1->flags) || FLAGS_GET_Z(geom2->flags));
830  GEOSGeometry *g1, *g2, *g3;
831 
832  if (srid == SRID_INVALID) return NULL;
833 
834  /* A.Union(empty) == A */
835  if (lwgeom_is_empty(geom1)) return lwgeom_clone_deep(geom2);
836 
837  /* B.Union(empty) == B */
838  if (lwgeom_is_empty(geom2)) return lwgeom_clone_deep(geom1);
839 
840  initGEOS(lwnotice, lwgeom_geos_error);
841 
842  if (!(g1 = LWGEOM2GEOS(geom1, AUTOFIX))) GEOS_FAIL();
843  if (!(g2 = LWGEOM2GEOS(geom2, AUTOFIX))) GEOS_FREE_AND_FAIL(g1);
844 
845  g3 = GEOSUnion(g1, g2);
846 
847  if (!g3) GEOS_FREE_AND_FAIL(g1, g2);
848  GEOSSetSRID(g3, srid);
849 
850  if (!(result = GEOS2LWGEOM(g3, is3d)))
851  GEOS_FREE_AND_FAIL(g1, g2, g3);
852 
853  GEOS_FREE(g1, g2, g3);
854  return result;
855 }
#define GEOS_FAIL()
LWGEOM * GEOS2LWGEOM(const GEOSGeometry *geom, uint8_t want3d)
void lwnotice(const char *fmt,...)
Write a notice out to the notice handler.
Definition: lwutil.c:177
uint8_t flags
Definition: liblwgeom.h:399
#define GEOS_FREE_AND_FAIL(...)
#define GEOS_FREE(...)
LWGEOM * lwgeom_clone_deep(const LWGEOM *lwgeom)
Deep clone an LWGEOM, everything is copied.
Definition: lwgeom.c:520
#define RESULT_SRID(...)
#define AUTOFIX
void lwgeom_geos_error(const char *fmt,...)
#define SRID_INVALID
Definition: liblwgeom.h:191
#define FLAGS_GET_Z(flags)
Macros for manipulating the 'flags' byte.
Definition: liblwgeom.h:139
GEOSGeometry * LWGEOM2GEOS(const LWGEOM *lwgeom, uint8_t autofix)
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:1393
unsigned char uint8_t
Definition: uthash.h:79
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