char *msudf_lineMerge(UDF_INIT *initid,UDF_ARGS *args, char *buf, unsigned long *length, char *is_null, char *error) { char *result; GEOSGeom geom1,geom2; DEBUG("msudf_lineMerge"); geom1 = msudf_getGeometry((unsigned char *)args->args[0],args->lengths[0]); if (geom1 == NULL) { strcpy(error,"Invalid geometry."); *is_null = 1; return NULL; } geom2 = GEOSLineMerge(geom1); if (geom2 != NULL) { GEOSSetSRID(geom2,GEOSGetSRID(geom1)); result = msudf_returnGeometry(initid,length,geom2); GEOSGeom_destroy(geom1); GEOSGeom_destroy(geom2); return result; } else { GEOSGeom_destroy(geom1); *is_null = 1; return NULL; } }
LWGEOM* lwgeom_node(const LWGEOM* lwgeom_in) { #if POSTGIS_GEOS_VERSION < 33 lwerror("The GEOS version this postgis binary " "was compiled against (%d) doesn't support " "'GEOSUnaryUnion' function (3.3.0+ required)", POSTGIS_GEOS_VERSION); return NULL; #else /* POSTGIS_GEOS_VERSION >= 33 */ GEOSGeometry *g1, *gu, *gm; LWGEOM *ep, *lines; LWCOLLECTION *col, *tc; int pn, ln, np, nl; if ( lwgeom_dimension(lwgeom_in) != 1 ) { lwerror("Noding geometries of dimension != 1 is unsupported"); return NULL; } initGEOS(lwgeom_geos_error, lwgeom_geos_error); g1 = LWGEOM2GEOS(lwgeom_in); if ( ! g1 ) { lwerror("LWGEOM2GEOS: %s", lwgeom_geos_errmsg); return NULL; } ep = lwgeom_extract_unique_endpoints(lwgeom_in); if ( ! ep ) { GEOSGeom_destroy(g1); lwerror("Error extracting unique endpoints from input"); return NULL; } /* Unary union input to fully node */ gu = GEOSUnaryUnion(g1); GEOSGeom_destroy(g1); if ( ! gu ) { lwgeom_free(ep); lwerror("GEOSUnaryUnion: %s", lwgeom_geos_errmsg); return NULL; } /* Linemerge (in case of overlaps) */ gm = GEOSLineMerge(gu); GEOSGeom_destroy(gu); if ( ! gm ) { lwgeom_free(ep); lwerror("GEOSLineMerge: %s", lwgeom_geos_errmsg); return NULL; } lines = GEOS2LWGEOM(gm, FLAGS_GET_Z(lwgeom_in->flags)); GEOSGeom_destroy(gm); if ( ! lines ) { lwgeom_free(ep); lwerror("Error during GEOS2LWGEOM"); return NULL; } /* * Reintroduce endpoints from input, using split-line-by-point. * Note that by now we can be sure that each point splits at * most _one_ segment as any point shared by multiple segments * would already be a node. Also we can be sure that any of * the segments endpoints won't split any other segment. * We can use the above 2 assertions to early exit the loop. */ col = lwcollection_construct_empty(MULTILINETYPE, lwgeom_in->srid, FLAGS_GET_Z(lwgeom_in->flags), FLAGS_GET_M(lwgeom_in->flags)); np = lwgeom_ngeoms(ep); for (pn=0; pn<np; ++pn) { /* for each point */ const LWPOINT* p = (LWPOINT*)lwgeom_subgeom(ep, pn); nl = lwgeom_ngeoms(lines); for (ln=0; ln<nl; ++ln) { /* for each line */ const LWLINE* l = (LWLINE*)lwgeom_subgeom(lines, ln); int s = lwline_split_by_point_to(l, p, (LWMLINE*)col); if ( ! s ) continue; /* not on this line */ if ( s == 1 ) { /* found on this line, but not splitting it */ break; } /* splits this line */ /* replace this line with the two splits */ if ( lwgeom_is_collection(lines) ) { tc = (LWCOLLECTION*)lines; lwcollection_reserve(tc, nl + 1); while (nl > ln+1) { tc->geoms[nl] = tc->geoms[nl-1]; --nl; } lwgeom_free(tc->geoms[ln]); tc->geoms[ln] = col->geoms[0]; tc->geoms[ln+1] = col->geoms[1]; tc->ngeoms++; } else { lwgeom_free(lines); /* transfer ownership rather than cloning */ lines = (LWGEOM*)lwcollection_clone_deep(col); assert(col->ngeoms == 2); lwgeom_free(col->geoms[0]); lwgeom_free(col->geoms[1]); } /* reset the vector */ assert(col->ngeoms == 2); col->ngeoms = 0; break; } } lwgeom_free(ep); lwcollection_free(col); lines->srid = lwgeom_in->srid; return (LWGEOM*)lines; #endif /* POSTGIS_GEOS_VERSION >= 33 */ }