PostGIS  2.5.1dev-r@@SVN_REVISION@@

◆ geography_distance_uncached()

Datum geography_distance_uncached ( PG_FUNCTION_ARGS  )

Definition at line 133 of file geography_measurement.c.

References SPHEROID::a, SPHEROID::b, distance(), error_if_srid_mismatch(), FP_TOLERANCE, geography_distance(), gserialized_get_srid(), lwgeom_add_bbox_deep(), lwgeom_distance_spheroid(), lwgeom_free(), lwgeom_from_gserialized(), lwgeom_is_empty(), PG_FUNCTION_INFO_V1(), SPHEROID::radius, and s.

Referenced by geography_distance_knn().

134 {
135  LWGEOM *lwgeom1 = NULL;
136  LWGEOM *lwgeom2 = NULL;
137  GSERIALIZED *g1 = NULL;
138  GSERIALIZED *g2 = NULL;
139  double distance;
140  double tolerance = FP_TOLERANCE;
141  bool use_spheroid = true;
142  SPHEROID s;
143 
144  /* Get our geometry objects loaded into memory. */
145  g1 = PG_GETARG_GSERIALIZED_P(0);
146  g2 = PG_GETARG_GSERIALIZED_P(1);
147 
148  /* Read our tolerance value. */
149  if ( PG_NARGS() > 2 && ! PG_ARGISNULL(2) )
150  tolerance = PG_GETARG_FLOAT8(2);
151 
152  /* Read our calculation type. */
153  if ( PG_NARGS() > 3 && ! PG_ARGISNULL(3) )
154  use_spheroid = PG_GETARG_BOOL(3);
155 
157 
158  /* Initialize spheroid */
159  spheroid_init_from_srid(fcinfo, gserialized_get_srid(g1), &s);
160 
161  /* Set to sphere if requested */
162  if ( ! use_spheroid )
163  s.a = s.b = s.radius;
164 
165  lwgeom1 = lwgeom_from_gserialized(g1);
166  lwgeom2 = lwgeom_from_gserialized(g2);
167 
168  /* Return NULL on empty arguments. */
169  if ( lwgeom_is_empty(lwgeom1) || lwgeom_is_empty(lwgeom2) )
170  {
171  PG_FREE_IF_COPY(g1, 0);
172  PG_FREE_IF_COPY(g2, 1);
173  PG_RETURN_NULL();
174  }
175 
176  /* Make sure we have boxes attached */
177  lwgeom_add_bbox_deep(lwgeom1, NULL);
178  lwgeom_add_bbox_deep(lwgeom2, NULL);
179 
180  distance = lwgeom_distance_spheroid(lwgeom1, lwgeom2, &s, tolerance);
181 
182  POSTGIS_DEBUGF(2, "[GIST] '%s' got distance %g", __func__, distance);
183 
184  /* Clean up */
185  lwgeom_free(lwgeom1);
186  lwgeom_free(lwgeom2);
187  PG_FREE_IF_COPY(g1, 0);
188  PG_FREE_IF_COPY(g2, 1);
189 
190  /* Something went wrong, negative return... should already be eloged, return NULL */
191  if ( distance < 0.0 )
192  {
193  PG_RETURN_NULL();
194  }
195 
196  PG_RETURN_FLOAT8(distance);
197 }
void lwgeom_add_bbox_deep(LWGEOM *lwgeom, GBOX *gbox)
Compute a box for geom and all sub-geometries, if not already computed.
Definition: lwgeom.c:705
LWGEOM * lwgeom_from_gserialized(const GSERIALIZED *g)
Allocate a new LWGEOM from a GSERIALIZED.
double b
Definition: liblwgeom.h:316
void lwgeom_free(LWGEOM *geom)
Definition: lwgeom.c:1144
double radius
Definition: liblwgeom.h:320
void error_if_srid_mismatch(int srid1, int srid2)
Definition: lwutil.c:338
#define FP_TOLERANCE
Floating point comparators.
char * s
Definition: cu_in_wkt.c:23
Datum distance(PG_FUNCTION_ARGS)
double a
Definition: liblwgeom.h:315
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:2100
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
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
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