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 */
}
