PostGIS  3.0.6dev-r@@SVN_REVISION@@

◆ geography_dwithin()

Datum geography_dwithin ( PG_FUNCTION_ARGS  )

Definition at line 275 of file geography_measurement.c.

276 {
277  GSERIALIZED *g1 = PG_GETARG_GSERIALIZED_P(0);
278  GSERIALIZED *g2 = PG_GETARG_GSERIALIZED_P(1);
279  SPHEROID s;
280  double tolerance = 0.0;
281  bool use_spheroid = true;
282  double distance;
283  int dwithin = LW_FALSE;
284 
285  gserialized_error_if_srid_mismatch(g1, g2, __func__);
286 
287  /* Read our tolerance value. */
288  if ( PG_NARGS() > 2 && ! PG_ARGISNULL(2) )
289  tolerance = PG_GETARG_FLOAT8(2);
290 
291  /* Read our calculation type. */
292  if ( PG_NARGS() > 3 && ! PG_ARGISNULL(3) )
293  use_spheroid = PG_GETARG_BOOL(3);
294 
295  /* Initialize spheroid */
296  spheroid_init_from_srid(fcinfo, gserialized_get_srid(g1), &s);
297 
298  /* Set to sphere if requested */
299  if ( ! use_spheroid )
300  s.a = s.b = s.radius;
301 
302  /* Return FALSE on empty arguments. */
304  PG_RETURN_BOOL(false);
305 
306  /* Do the brute force calculation if the cached calculation doesn't tick over */
307  if ( LW_FAILURE == geography_dwithin_cache(fcinfo, g1, g2, &s, tolerance, &dwithin) )
308  {
309  LWGEOM* lwgeom1 = lwgeom_from_gserialized(g1);
310  LWGEOM* lwgeom2 = lwgeom_from_gserialized(g2);
311  distance = lwgeom_distance_spheroid(lwgeom1, lwgeom2, &s, tolerance);
312  /* Something went wrong... */
313  if ( distance < 0.0 )
314  elog(ERROR, "lwgeom_distance_spheroid returned negative!");
315  dwithin = (distance <= tolerance);
316  lwgeom_free(lwgeom1);
317  lwgeom_free(lwgeom2);
318  }
319 
320  PG_FREE_IF_COPY(g1, 0);
321  PG_FREE_IF_COPY(g2, 1);
322  PG_RETURN_BOOL(dwithin);
323 }
char * s
Definition: cu_in_wkt.c:23
int geography_dwithin_cache(FunctionCallInfo fcinfo, const GSERIALIZED *g1, const GSERIALIZED *g2, const SPHEROID *s, double tolerance, int *dwithin)
void gserialized_error_if_srid_mismatch(const GSERIALIZED *g1, const GSERIALIZED *g2, const char *funcname)
Definition: gserialized.c:404
int32_t gserialized_get_srid(const GSERIALIZED *g)
Extract the SRID from the serialized form (it is packed into three bytes so this is a handy function)...
Definition: gserialized.c:126
LWGEOM * lwgeom_from_gserialized(const GSERIALIZED *g)
Allocate a new LWGEOM from a GSERIALIZED.
Definition: gserialized.c:239
int gserialized_is_empty(const GSERIALIZED *g)
Check if a GSERIALIZED is empty without deserializing first.
Definition: gserialized.c:152
#define LW_FALSE
Definition: liblwgeom.h:108
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:2187
#define LW_FAILURE
Definition: liblwgeom.h:110
void lwgeom_free(LWGEOM *geom)
Definition: lwgeom.c:1138
static double distance(double x1, double y1, double x2, double y2)
Definition: lwtree.c:1032

References distance(), geography_dwithin_cache(), gserialized_error_if_srid_mismatch(), gserialized_get_srid(), gserialized_is_empty(), LW_FAILURE, LW_FALSE, lwgeom_distance_spheroid(), lwgeom_free(), lwgeom_from_gserialized(), and s.

Referenced by geography_intersects().

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