Datum ST_LocateBetweenElevations(PG_FUNCTION_ARGS)
{
GSERIALIZED *geom_in = PG_GETARG_GSERIALIZED_P(0);
double from = PG_GETARG_FLOAT8(1);
double to = PG_GETARG_FLOAT8(2);
LWCOLLECTION *geom_out = NULL;
LWGEOM *line_in = NULL;
static char ordinate = 'Z'; /* Z */
static double offset = 0.0;
if ( ! gserialized_has_z(geom_in) )
{
elog(ERROR,"This function only accepts LINESTRING or MULTILINESTRING with Z dimensions.");
PG_RETURN_NULL();
}
line_in = lwgeom_from_gserialized(geom_in);
geom_out = lwgeom_clip_to_ordinate_range(line_in, ordinate, from, to, offset);
lwgeom_free(line_in);
PG_FREE_IF_COPY(geom_in, 0);
if ( ! geom_out )
{
elog(ERROR,"lwline_clip_to_ordinate_range returned null");
PG_RETURN_NULL();
}
PG_RETURN_POINTER(geometry_serialize((LWGEOM*)geom_out));
}
Datum ST_LocateBetween(PG_FUNCTION_ARGS)
{
GSERIALIZED *geom_in = PG_GETARG_GSERIALIZED_P(0);
double from = PG_GETARG_FLOAT8(1);
double to = PG_GETARG_FLOAT8(2);
double offset = PG_GETARG_FLOAT8(3);
LWCOLLECTION *geom_out = NULL;
LWGEOM *line_in = NULL;
static char ordinate = 'M'; /* M */
if ( ! gserialized_has_m(geom_in) )
{
elog(ERROR,"This function only accepts geometries that have an M dimension.");
PG_RETURN_NULL();
}
/* This should be a call to ST_LocateAlong! */
if ( to == from )
{
PG_RETURN_DATUM(DirectFunctionCall3(ST_LocateAlong, PG_GETARG_DATUM(0), PG_GETARG_DATUM(1), PG_GETARG_DATUM(3)));
}
line_in = lwgeom_from_gserialized(geom_in);
geom_out = lwgeom_clip_to_ordinate_range(line_in, ordinate, from, to, offset);
lwgeom_free(line_in);
PG_FREE_IF_COPY(geom_in, 0);
if ( ! geom_out )
{
elog(ERROR,"lwline_clip_to_ordinate_range returned null");
PG_RETURN_NULL();
}
PG_RETURN_POINTER(geometry_serialize((LWGEOM*)geom_out));
}
LWCOLLECTION*
lwgeom_locate_between(const LWGEOM *lwin, double from, double to, double offset)
{
if ( ! lwgeom_has_m(lwin) )
lwerror("Input geometry does not have a measure dimension");
return lwgeom_clip_to_ordinate_range(lwin, 'M', from, to, offset);
}
