PostGIS  2.5.1dev-r@@SVN_REVISION@@

◆ ST_FrechetDistance()

Datum ST_FrechetDistance ( PG_FUNCTION_ARGS  )

Definition at line 274 of file postgis/lwgeom_geos.c.

References gserialized_is_empty(), HANDLE_GEOS_ERROR, lwgeom_geos_error(), PG_FUNCTION_INFO_V1(), pgis_union_geometry_array(), POSTGIS2GEOS(), and POSTGIS_GEOS_VERSION.

Referenced by hausdorffdistancedensify().

275 {
276 #if POSTGIS_GEOS_VERSION < 37
277 
278  lwpgerror("The GEOS version this PostGIS binary "
279  "was compiled against (%d) doesn't support "
280  "'GEOSFechetDistance' function (3.7.0+ required)",
282  PG_RETURN_NULL();
283 
284 #else /* POSTGIS_GEOS_VERSION >= 37 */
285  GSERIALIZED *geom1;
286  GSERIALIZED *geom2;
287  GEOSGeometry *g1;
288  GEOSGeometry *g2;
289  double densifyFrac;
290  double result;
291  int retcode;
292 
293  geom1 = PG_GETARG_GSERIALIZED_P(0);
294  geom2 = PG_GETARG_GSERIALIZED_P(1);
295  densifyFrac = PG_GETARG_FLOAT8(2);
296 
297  if ( gserialized_is_empty(geom1) || gserialized_is_empty(geom2) )
298  PG_RETURN_NULL();
299 
300  initGEOS(lwpgnotice, lwgeom_geos_error);
301 
302  g1 = POSTGIS2GEOS(geom1);
303  if (!g1)
304  HANDLE_GEOS_ERROR("First argument geometry could not be converted to GEOS");
305 
306  g2 = POSTGIS2GEOS(geom2);
307  if (!g2)
308  {
309  GEOSGeom_destroy(g1);
310  HANDLE_GEOS_ERROR("Second argument geometry could not be converted to GEOS");
311  }
312 
313  if (densifyFrac <= 0.0)
314  {
315  retcode = GEOSFrechetDistance(g1, g2, &result);
316  }
317  else
318  {
319  retcode = GEOSFrechetDistanceDensify(g1, g2, densifyFrac, &result);
320  }
321 
322  GEOSGeom_destroy(g1);
323  GEOSGeom_destroy(g2);
324 
325  if (retcode == 0) HANDLE_GEOS_ERROR("GEOSFrechetDistance");
326 
327  PG_FREE_IF_COPY(geom1, 0);
328  PG_FREE_IF_COPY(geom2, 1);
329 
330  PG_RETURN_FLOAT8(result);
331 
332 #endif /* POSTGIS_GEOS_VERSION >= 37 */
333 }
#define POSTGIS_GEOS_VERSION
Definition: sqldefines.h:10
int gserialized_is_empty(const GSERIALIZED *g)
Check if a GSERIALIZED is empty without deserializing first.
Definition: g_serialized.c:178
void lwgeom_geos_error(const char *fmt,...)
GEOSGeometry * POSTGIS2GEOS(GSERIALIZED *pglwgeom)
#define HANDLE_GEOS_ERROR(label)
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