PostGIS 3.0.6dev-r@@SVN_REVISION@@
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◆ LWGEOM_asKML()

Datum LWGEOM_asKML ( PG_FUNCTION_ARGS  )

Definition at line 170 of file postgis/lwgeom_transform.c.

171{
172 LWGEOM *lwgeom;
173 char *kml;
174 text *result;
175 const char *default_prefix = ""; /* default prefix */
176 char *prefixbuf;
177 const char *prefix = default_prefix;
178 int32_t srid_from;
179 const int32_t srid_to = 4326;
180
181 /* Get the geometry */
182 GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P_COPY(0);
183 int precision = PG_GETARG_INT32(1);
184 text *prefix_text = PG_GETARG_TEXT_P(2);
185 srid_from = gserialized_get_srid(geom);
186
187 if ( srid_from == SRID_UNKNOWN )
188 {
189 PG_FREE_IF_COPY(geom, 0);
190 elog(ERROR, "ST_AsKML: Input geometry has unknown (%d) SRID", SRID_UNKNOWN);
191 PG_RETURN_NULL();
192 }
193
194 /* Condition precision */
195 if (precision > DBL_DIG)
196 precision = DBL_DIG;
197 if (precision < 0)
198 precision = 0;
199
200 if (VARSIZE_ANY_EXHDR(prefix_text) > 0)
201 {
202 /* +2 is one for the ':' and one for term null */
203 prefixbuf = palloc(VARSIZE_ANY_EXHDR(prefix_text)+2);
204 memcpy(prefixbuf, VARDATA(prefix_text),
205 VARSIZE_ANY_EXHDR(prefix_text));
206 /* add colon and null terminate */
207 prefixbuf[VARSIZE_ANY_EXHDR(prefix_text)] = ':';
208 prefixbuf[VARSIZE_ANY_EXHDR(prefix_text)+1] = '\0';
209 prefix = prefixbuf;
210 }
211
212 lwgeom = lwgeom_from_gserialized(geom);
213
214 if (srid_from != srid_to)
215 {
216 LWPROJ *pj;
217 if (GetPJUsingFCInfo(fcinfo, srid_from, srid_to, &pj) == LW_FAILURE)
218 {
219 PG_FREE_IF_COPY(geom, 0);
220 elog(ERROR, "ST_AsKML: Failure reading projections from spatial_ref_sys.");
221 PG_RETURN_NULL();
222 }
223 lwgeom_transform(lwgeom, pj);
224 }
225
226 kml = lwgeom_to_kml2(lwgeom, precision, prefix);
227 lwgeom_free(lwgeom);
228 PG_FREE_IF_COPY(geom, 0);
229
230 if (!kml)
231 PG_RETURN_NULL();
232
233 result = cstring_to_text(kml);
234 lwfree(kml);
235
236 PG_RETURN_POINTER(result);
237}
static uint8_t precision
Definition cu_in_twkb.c:25
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)...
LWGEOM * lwgeom_from_gserialized(const GSERIALIZED *g)
Allocate a new LWGEOM from a GSERIALIZED.
#define LW_FAILURE
Definition liblwgeom.h:110
int lwgeom_transform(LWGEOM *geom, LWPROJ *pj)
Transform (reproject) a geometry in-place.
void lwgeom_free(LWGEOM *geom)
Definition lwgeom.c:1138
char * lwgeom_to_kml2(const LWGEOM *geom, int precision, const char *prefix)
Definition lwout_kml.c:44
void lwfree(void *mem)
Definition lwutil.c:242
#define SRID_UNKNOWN
Unknown SRID value.
Definition liblwgeom.h:229

References gserialized_get_srid(), LW_FAILURE, lwfree(), lwgeom_free(), lwgeom_from_gserialized(), lwgeom_to_kml2(), lwgeom_transform(), precision, and SRID_UNKNOWN.

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