PostGIS  2.5.0dev-r@@SVN_REVISION@@

◆ ST_ClipByBox2d()

Datum ST_ClipByBox2d ( PG_FUNCTION_ARGS  )

Definition at line 1413 of file postgis/lwgeom_geos.c.

References GBOX::flags, gbox_contains_2d(), gbox_overlaps_2d(), geometry_serialize(), lwgeom_clip_by_rect(), lwgeom_construct_empty(), lwgeom_free(), lwgeom_from_gserialized(), lwgeom_get_bbox(), POSTGIS_GEOS_VERSION, LWGEOM::srid, LWGEOM::type, GBOX::xmax, GBOX::xmin, GBOX::ymax, and GBOX::ymin.

Referenced by centroid().

1414 {
1415 #if POSTGIS_GEOS_VERSION < 35
1416 
1417  lwpgerror("The GEOS version this PostGIS binary "
1418  "was compiled against (%d) doesn't support "
1419  "'GEOSClipByRect' function (3.5.0+ required)",
1421  PG_RETURN_NULL();
1422 
1423 #else /* POSTGIS_GEOS_VERSION >= 35 */
1424 
1425  GSERIALIZED *geom1;
1426  GSERIALIZED *result;
1427  LWGEOM *lwgeom1, *lwresult ;
1428  const GBOX *bbox1;
1429  GBOX *bbox2;
1430 
1431  geom1 = PG_GETARG_GSERIALIZED_P(0);
1432  lwgeom1 = lwgeom_from_gserialized(geom1) ;
1433 
1434  bbox1 = lwgeom_get_bbox(lwgeom1);
1435  if ( ! bbox1 )
1436  {
1437  /* empty clips to empty, no matter rect */
1438  lwgeom_free(lwgeom1);
1439  PG_RETURN_POINTER(geom1);
1440  }
1441 
1442  /* WARNING: this is really a BOX2DF, use only xmin and ymin fields */
1443  bbox2 = (GBOX *)PG_GETARG_POINTER(1);
1444  bbox2->flags = 0;
1445 
1446  /* If bbox1 outside of bbox2, return empty */
1447  if ( ! gbox_overlaps_2d(bbox1, bbox2) )
1448  {
1449  lwresult = lwgeom_construct_empty(lwgeom1->type, lwgeom1->srid, 0, 0);
1450  lwgeom_free(lwgeom1);
1451  PG_FREE_IF_COPY(geom1, 0);
1452  result = geometry_serialize(lwresult) ;
1453  lwgeom_free(lwresult) ;
1454  PG_RETURN_POINTER(result);
1455  }
1456 
1457  /* if bbox1 is covered by bbox2, return lwgeom1 */
1458  if ( gbox_contains_2d(bbox2, bbox1) )
1459  {
1460  lwgeom_free(lwgeom1);
1461  PG_RETURN_POINTER(geom1);
1462  }
1463 
1464  lwresult = lwgeom_clip_by_rect(lwgeom1, bbox2->xmin, bbox2->ymin,
1465  bbox2->xmax, bbox2->ymax);
1466 
1467  lwgeom_free(lwgeom1);
1468  PG_FREE_IF_COPY(geom1, 0);
1469 
1470  if (!lwresult) PG_RETURN_NULL();
1471 
1472  result = geometry_serialize(lwresult) ;
1473  lwgeom_free(lwresult) ;
1474  PG_RETURN_POINTER(result);
1475 
1476 #endif /* POSTGIS_GEOS_VERSION >= 35 */
1477 }
#define POSTGIS_GEOS_VERSION
Definition: sqldefines.h:10
LWGEOM * lwgeom_from_gserialized(const GSERIALIZED *g)
Allocate a new LWGEOM from a GSERIALIZED.
double xmax
Definition: liblwgeom.h:295
void lwgeom_free(LWGEOM *geom)
Definition: lwgeom.c:1144
LWGEOM * lwgeom_clip_by_rect(const LWGEOM *geom1, double x0, double y0, double x1, double y1)
int gbox_contains_2d(const GBOX *g1, const GBOX *g2)
Return LW_TRUE if the first GBOX contains the second on the 2d plane, LW_FALSE otherwise.
Definition: g_box.c:346
int32_t srid
Definition: liblwgeom.h:401
double ymin
Definition: liblwgeom.h:296
double xmin
Definition: liblwgeom.h:294
const GBOX * lwgeom_get_bbox(const LWGEOM *lwgeom)
Get a non-empty geometry bounding box, computing and caching it if not already there.
Definition: lwgeom.c:734
double ymax
Definition: liblwgeom.h:297
LWGEOM * lwgeom_construct_empty(uint8_t type, int srid, char hasz, char hasm)
Definition: lwgeom.c:2085
uint8_t flags
Definition: liblwgeom.h:293
int gbox_overlaps_2d(const GBOX *g1, const GBOX *g2)
Return LW_TRUE if the GBOX overlaps on the 2d plane, LW_FALSE otherwise.
Definition: g_box.c:330
GSERIALIZED * geometry_serialize(LWGEOM *lwgeom)
uint8_t type
Definition: liblwgeom.h:398
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