static LWGEOM* lwline_split_by_point(const LWLINE* lwline_in, const LWPOINT* blade_in) { LWMLINE* out; out = lwmline_construct_empty(lwline_in->srid, FLAGS_GET_Z(lwline_in->flags), FLAGS_GET_M(lwline_in->flags)); if ( lwline_split_by_point_to(lwline_in, blade_in, out) < 2 ) { lwmline_add_lwline(out, lwline_clone_deep(lwline_in)); } /* Turn multiline into collection */ out->type = COLLECTIONTYPE; return (LWGEOM*)out; }
static LWGEOM* lwline_split_by_mpoint(const LWLINE* lwline_in, const LWMPOINT* mp) { LWMLINE* out; int i, j; out = lwmline_construct_empty(lwline_in->srid, FLAGS_GET_Z(lwline_in->flags), FLAGS_GET_M(lwline_in->flags)); lwmline_add_lwline(out, lwline_clone_deep(lwline_in)); for (i=0; i<mp->ngeoms; ++i) { for (j=0; j<out->ngeoms; ++j) { lwline_in = out->geoms[j]; LWPOINT *blade_in = mp->geoms[i]; int ret = lwline_split_by_point_to(lwline_in, blade_in, out); if ( 2 == ret ) { /* the point splits this line, * 2 splits were added to collection. * We'll move the latest added into * the slot of the current one. */ lwline_free(out->geoms[j]); out->geoms[j] = out->geoms[--out->ngeoms]; } } } /* Turn multiline into collection */ out->type = COLLECTIONTYPE; return (LWGEOM*)out; }
static void test_lwline_split_by_point_to(void) { #if POSTGIS_GEOS_VERSION >= 33 LWLINE *line; LWPOINT *point; LWMLINE *coll; int ret; /* Because i don't trust that much prior tests... ;) */ cu_error_msg_reset(); coll = lwmline_construct_empty(SRID_UNKNOWN, 0, 0); CU_ASSERT_EQUAL(coll->ngeoms, 0); line = lwgeom_as_lwline(lwgeom_from_wkt("LINESTRING(0 0,5 5, 10 0)", LW_PARSER_CHECK_NONE)); CU_ASSERT(line != NULL); point = lwgeom_as_lwpoint(lwgeom_from_wkt( "POINT(0 0)", LW_PARSER_CHECK_NONE)); ret = lwline_split_by_point_to(line, point, coll); CU_ASSERT_EQUAL(ret, 1); CU_ASSERT_EQUAL(coll->ngeoms, 0); lwpoint_free(point); point = lwgeom_as_lwpoint(lwgeom_from_wkt( "POINT(10 0)", LW_PARSER_CHECK_NONE)); ret = lwline_split_by_point_to(line, point, coll); CU_ASSERT_EQUAL(ret, 1); CU_ASSERT_EQUAL(coll->ngeoms, 0); lwpoint_free(point); point = lwgeom_as_lwpoint(lwgeom_from_wkt( "POINT(5 0)", LW_PARSER_CHECK_NONE)); ret = lwline_split_by_point_to(line, point, coll); CU_ASSERT_EQUAL(ret, 0); CU_ASSERT_EQUAL(coll->ngeoms, 0); lwpoint_free(point); point = lwgeom_as_lwpoint(lwgeom_from_wkt( "POINT(5 5)", LW_PARSER_CHECK_NONE)); ret = lwline_split_by_point_to(line, point, coll); CU_ASSERT_EQUAL(ret, 2); CU_ASSERT_EQUAL(coll->ngeoms, 2); lwpoint_free(point); point = lwgeom_as_lwpoint(lwgeom_from_wkt( "POINT(2 2)", LW_PARSER_CHECK_NONE)); ret = lwline_split_by_point_to(line, point, coll); CU_ASSERT_EQUAL(ret, 2); CU_ASSERT_EQUAL(coll->ngeoms, 4); lwpoint_free(point); lwcollection_free((LWCOLLECTION*)coll); lwline_free(line); #endif /* POSTGIS_GEOS_VERSION >= 33 */ }
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 */ }