Datum ST_LocateBetweenElevations(PG_FUNCTION_ARGS)
{
GSERIALIZED *geom_in = (GSERIALIZED *)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
double from = PG_GETARG_FLOAT8(1);
double to = PG_GETARG_FLOAT8(2);
LWCOLLECTION *geom_out = NULL;
LWGEOM *line_in = NULL;
char geomtype = gserialized_get_type(geom_in);
static int ordinate = 2; /* Z */
if ( ! ( geomtype == LINETYPE || geomtype == MULTILINETYPE ) )
{
elog(ERROR,"This function only accepts LINESTRING or MULTILINESTRING as arguments.");
PG_RETURN_NULL();
}
line_in = lwgeom_from_gserialized(geom_in);
if ( ! FLAGS_GET_Z(line_in->flags) )
{
elog(ERROR,"This function only accepts LINESTRING or MULTILINESTRING with Z values as arguments.");
PG_RETURN_NULL();
}
if ( geomtype == LINETYPE )
{
geom_out = lwline_clip_to_ordinate_range((LWLINE*)line_in, ordinate, from, to);
}
else if ( geomtype == MULTILINETYPE )
{
geom_out = lwmline_clip_to_ordinate_range((LWMLINE*)line_in, ordinate, from, to);
}
lwgeom_free(line_in);
if ( ! geom_out )
{
elog(ERROR,"The lwline_clip_to_ordinate_range returned null.");
PG_RETURN_NULL();
}
PG_FREE_IF_COPY(geom_in, 0);
PG_RETURN_POINTER(geometry_serialize((LWGEOM*)geom_out));
}
LWCOLLECTION*
lwgeom_clip_to_ordinate_range(const LWGEOM *lwin, char ordinate, double from, double to, double offset)
{
LWCOLLECTION *out_col;
LWCOLLECTION *out_offset;
int i;
if ( ! lwin )
lwerror("lwgeom_clip_to_ordinate_range: null input geometry!");
switch ( lwin->type )
{
case LINETYPE:
out_col = lwline_clip_to_ordinate_range((LWLINE*)lwin, ordinate, from, to);
break;
case MULTILINETYPE:
out_col = lwmline_clip_to_ordinate_range((LWMLINE*)lwin, ordinate, from, to);
break;
case MULTIPOINTTYPE:
out_col = lwmpoint_clip_to_ordinate_range((LWMPOINT*)lwin, ordinate, from, to);
break;
case POINTTYPE:
out_col = lwpoint_clip_to_ordinate_range((LWPOINT*)lwin, ordinate, from, to);
break;
default:
lwerror("This function does not accept %s geometries.", lwtype_name(lwin->type));
return NULL;;
}
/* Stop if result is NULL */
if ( out_col == NULL )
lwerror("lwgeom_clip_to_ordinate_range clipping routine returned NULL");
/* Return if we aren't going to offset the result */
if ( FP_EQUALS(offset, 0.0) || lwgeom_is_empty(lwcollection_as_lwgeom(out_col)) )
return out_col;
/* Construct a collection to hold our outputs. */
/* Things get ugly: GEOS offset drops Z's and M's so we have to drop ours */
out_offset = lwcollection_construct_empty(MULTILINETYPE, lwin->srid, 0, 0);
/* Try and offset the linear portions of the return value */
for ( i = 0; i < out_col->ngeoms; i++ )
{
int type = out_col->geoms[i]->type;
if ( type == POINTTYPE )
{
lwnotice("lwgeom_clip_to_ordinate_range cannot offset a clipped point");
continue;
}
else if ( type == LINETYPE )
{
/* lwgeom_offsetcurve(line, offset, quadsegs, joinstyle (round), mitrelimit) */
LWGEOM *lwoff = lwgeom_offsetcurve(lwgeom_as_lwline(out_col->geoms[i]), offset, 8, 1, 5.0);
if ( ! lwoff )
{
lwerror("lwgeom_offsetcurve returned null");
}
lwcollection_add_lwgeom(out_offset, lwoff);
}
else
{
lwerror("lwgeom_clip_to_ordinate_range found an unexpected type (%s) in the offset routine",lwtype_name(type));
}
}
return out_offset;
}
static void test_lwmline_clip(void)
{
LWCOLLECTION *c;
char *ewkt;
LWMLINE *mline = NULL;
LWLINE *line = NULL;
/*
** Set up the input line. Trivial one-member case.
*/
mline = (LWMLINE*)lwgeom_from_wkt("MULTILINESTRING((0 0,0 1,0 2,0 3,0 4))", LW_PARSER_CHECK_NONE);
/* Clip in the middle, mid-range. */
c = lwmline_clip_to_ordinate_range(mline, 'Y', 1.5, 2.5);
ewkt = lwgeom_to_ewkt((LWGEOM*)c);
//printf("c = %s\n", ewkt);
CU_ASSERT_STRING_EQUAL(ewkt, "MULTILINESTRING((0 1.5,0 2,0 2.5))");
lwfree(ewkt);
lwcollection_free(c);
lwmline_free(mline);
/*
** Set up the input line. Two-member case.
*/
mline = (LWMLINE*)lwgeom_from_wkt("MULTILINESTRING((1 0,1 1,1 2,1 3,1 4), (0 0,0 1,0 2,0 3,0 4))", LW_PARSER_CHECK_NONE);
/* Clip off the top. */
c = lwmline_clip_to_ordinate_range(mline, 'Y', 3.5, 5.5);
ewkt = lwgeom_to_ewkt((LWGEOM*)c);
//printf("c = %s\n", ewkt);
CU_ASSERT_STRING_EQUAL(ewkt, "MULTILINESTRING((1 3.5,1 4),(0 3.5,0 4))");
lwfree(ewkt);
lwcollection_free(c);
lwmline_free(mline);
/*
** Set up staggered input line to create multi-type output.
*/
mline = (LWMLINE*)lwgeom_from_wkt("MULTILINESTRING((1 0,1 -1,1 -2,1 -3,1 -4), (0 0,0 1,0 2,0 3,0 4))", LW_PARSER_CHECK_NONE);
/* Clip from 0 upwards.. */
c = lwmline_clip_to_ordinate_range(mline, 'Y', 0.0, 2.5);
ewkt = lwgeom_to_ewkt((LWGEOM*)c);
//printf("c = %s\n", ewkt);
CU_ASSERT_STRING_EQUAL(ewkt, "GEOMETRYCOLLECTION(POINT(1 0),LINESTRING(0 0,0 1,0 2,0 2.5))");
lwfree(ewkt);
lwcollection_free(c);
lwmline_free(mline);
/*
** Set up input line from MAC
*/
line = (LWLINE*)lwgeom_from_wkt("LINESTRING(0 0 0 0,1 1 1 1,2 2 2 2,3 3 3 3,4 4 4 4,3 3 3 5,2 2 2 6,1 1 1 7,0 0 0 8)", LW_PARSER_CHECK_NONE);
/* Clip from 3 to 3.5 */
c = lwline_clip_to_ordinate_range(line, 'Z', 3.0, 3.5);
ewkt = lwgeom_to_ewkt((LWGEOM*)c);
//printf("c = %s\n", ewkt);
CU_ASSERT_STRING_EQUAL(ewkt, "MULTILINESTRING((3 3 3 3,3.5 3.5 3.5 3.5),(3.5 3.5 3.5 4.5,3 3 3 5))");
lwfree(ewkt);
lwcollection_free(c);
/* Clip from 2 to 3.5 */
c = lwline_clip_to_ordinate_range(line, 'Z', 2.0, 3.5);
ewkt = lwgeom_to_ewkt((LWGEOM*)c);
//printf("c = %s\n", ewkt);
CU_ASSERT_STRING_EQUAL(ewkt, "MULTILINESTRING((2 2 2 2,3 3 3 3,3.5 3.5 3.5 3.5),(3.5 3.5 3.5 4.5,3 3 3 5,2 2 2 6))");
lwfree(ewkt);
lwcollection_free(c);
/* Clip from 3 to 4 */
c = lwline_clip_to_ordinate_range(line, 'Z', 3.0, 4.0);
ewkt = lwgeom_to_ewkt((LWGEOM*)c);
//printf("c = %s\n", ewkt);
CU_ASSERT_STRING_EQUAL(ewkt, "MULTILINESTRING((3 3 3 3,4 4 4 4,3 3 3 5))");
lwfree(ewkt);
lwcollection_free(c);
/* Clip from 2 to 3 */
c = lwline_clip_to_ordinate_range(line, 'Z', 2.0, 3.0);
ewkt = lwgeom_to_ewkt((LWGEOM*)c);
//printf("c = %s\n", ewkt);
CU_ASSERT_STRING_EQUAL(ewkt, "MULTILINESTRING((2 2 2 2,3 3 3 3),(3 3 3 5,2 2 2 6))");
lwfree(ewkt);
lwcollection_free(c);
lwline_free(line);
}
