PostGIS  2.5.0dev-r@@SVN_REVISION@@
Datum geography_dwithin_uncached ( PG_FUNCTION_ARGS  )

Definition at line 396 of file geography_measurement.c.

References SPHEROID::a, SPHEROID::b, distance(), error_if_srid_mismatch(), gserialized_get_srid(), lwgeom_distance_spheroid(), lwgeom_free(), lwgeom_from_gserialized(), lwgeom_is_empty(), SPHEROID::radius, and s.

397 {
398  LWGEOM *lwgeom1 = NULL;
399  LWGEOM *lwgeom2 = NULL;
400  GSERIALIZED *g1 = NULL;
401  GSERIALIZED *g2 = NULL;
402  double tolerance = 0.0;
403  double distance;
404  bool use_spheroid = true;
405  SPHEROID s;
406 
407  /* Get our geometry objects loaded into memory. */
408  g1 = PG_GETARG_GSERIALIZED_P(0);
409  g2 = PG_GETARG_GSERIALIZED_P(1);
410 
411  /* Read our tolerance value. */
412  if ( PG_NARGS() > 2 && ! PG_ARGISNULL(2) )
413  tolerance = PG_GETARG_FLOAT8(2);
414 
415  /* Read our calculation type. */
416  if ( PG_NARGS() > 3 && ! PG_ARGISNULL(3) )
417  use_spheroid = PG_GETARG_BOOL(3);
418 
420 
421  /* Initialize spheroid */
422  spheroid_init_from_srid(fcinfo, gserialized_get_srid(g1), &s);
423 
424  /* Set to sphere if requested */
425  if ( ! use_spheroid )
426  s.a = s.b = s.radius;
427 
428  lwgeom1 = lwgeom_from_gserialized(g1);
429  lwgeom2 = lwgeom_from_gserialized(g2);
430 
431  /* Return FALSE on empty arguments. */
432  if ( lwgeom_is_empty(lwgeom1) || lwgeom_is_empty(lwgeom2) )
433  {
434  PG_RETURN_BOOL(false);
435  }
436 
437  distance = lwgeom_distance_spheroid(lwgeom1, lwgeom2, &s, tolerance);
438 
439  /* Clean up */
440  lwgeom_free(lwgeom1);
441  lwgeom_free(lwgeom2);
442  PG_FREE_IF_COPY(g1, 0);
443  PG_FREE_IF_COPY(g2, 1);
444 
445  /* Something went wrong... should already be eloged, return FALSE */
446  if ( distance < 0.0 )
447  {
448  elog(ERROR, "lwgeom_distance_spheroid returned negative!");
449  PG_RETURN_BOOL(false);
450  }
451 
452  PG_RETURN_BOOL(distance <= tolerance);
453 }
LWGEOM * lwgeom_from_gserialized(const GSERIALIZED *g)
Allocate a new LWGEOM from a GSERIALIZED.
double b
Definition: liblwgeom.h:313
void lwgeom_free(LWGEOM *geom)
Definition: lwgeom.c:1137
double radius
Definition: liblwgeom.h:317
void error_if_srid_mismatch(int srid1, int srid2)
Definition: lwutil.c:338
char * s
Definition: cu_in_wkt.c:23
Datum distance(PG_FUNCTION_ARGS)
double a
Definition: liblwgeom.h:312
double lwgeom_distance_spheroid(const LWGEOM *lwgeom1, const LWGEOM *lwgeom2, const SPHEROID *spheroid, double tolerance)
Calculate the geodetic distance from lwgeom1 to lwgeom2 on the spheroid.
Definition: lwgeodetic.c:2096
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:1386
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:99

Here is the call graph for this function: