From 092fb61dc4090e23b9709cb0fdf4d787e0a40cd3 Mon Sep 17 00:00:00 2001
From: Sandro Santilli <strk@keybit.net>
Date: Mon, 6 Sep 2004 12:24:17 +0000
Subject: [PATCH] Added IsEmpty()

git-svn-id: http://svn.osgeo.org/postgis/trunk@770 b70326c6-7e19-0410-871a-916f4a2858ee
---
 lwgeom/MISSING_OBJECTS          |  9 ++++-----
 lwgeom/lwgeom_functions_basic.c | 11 +++++++++++
 lwgeom/lwgeom_inout.c           |  2 +-
 lwgeom/lwpostgis.sql.in         |  5 +++++
 4 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/lwgeom/MISSING_OBJECTS b/lwgeom/MISSING_OBJECTS
index 0c6bd4556..586eb232c 100644
--- a/lwgeom/MISSING_OBJECTS
+++ b/lwgeom/MISSING_OBJECTS
@@ -3,19 +3,16 @@
 FNCAST: KEEPING FNCAST geometry(text) (see CAST)
 FUNC: KEEPING FUNCTION: [line_interpolate_point(geometry, double precision)]
 FUNC: KEEPING FUNCTION: [simplify(geometry, double precision)]
+FUNC: KEEPING FUNCTION: [segmentize(geometry, double precision)]
 FUNC: KEEPING FUNCTION: [asbinary(geometry)]
 FUNC: KEEPING FUNCTION: [asbinary(geometry, text)]
-FUNC: KEEPING FUNCTION: [boundary(geometry)]
-FUNC: KEEPING FUNCTION: [equals(geometry, geometry)]
-FUNC: KEEPING FUNCTION: [isempty(geometry)]
-FUNC: KEEPING FUNCTION: [segmentize(geometry, double precision)]
-FUNC: KEEPING FUNCTION: [unite_garray(geometry[])]
 
 --- OBSOLETED ?
 FUNC: KEEPING FUNCTION: [geometry_size(geometry, internal)]
 FUNC: KEEPING FUNCTION: [optimistic_overlap(geometry, geometry, double precision)]
 
 --- GEOS
+FUNC: KEEPING FUNCTION: [unite_garray(geometry[])]
 FUNC: KEEPING FUNCTION: [centroid(geometry)]  (Also !GEOS implementation)
 AGGREGATE: KEEPING AGGREGATE [memgeomunion(geometry)]
 AGGREGATE: KEEPING AGGREGATE [geomunion(geometry)]
@@ -40,6 +37,8 @@ FUNC: KEEPING FUNCTION: [geomunion(geometry, geometry)]
 FUNC: KEEPING FUNCTION: [geosnoop(geometry)]
 FUNC: KEEPING FUNCTION: [intersection(geometry, geometry)]
 FUNC: KEEPING FUNCTION: [intersects(geometry, geometry)]
+FUNC: KEEPING FUNCTION: [equals(geometry, geometry)]
+FUNC: KEEPING FUNCTION: [boundary(geometry)]
 
 --- CHIP
 FUNC: KEEPING FUNCTION: [chip_in(cstring)]
diff --git a/lwgeom/lwgeom_functions_basic.c b/lwgeom/lwgeom_functions_basic.c
index 32930638f..edfa8531e 100644
--- a/lwgeom/lwgeom_functions_basic.c
+++ b/lwgeom/lwgeom_functions_basic.c
@@ -40,6 +40,7 @@ Datum LWGEOM_collect_garray(PG_FUNCTION_ARGS);
 Datum LWGEOM_expand(PG_FUNCTION_ARGS);
 Datum LWGEOM_to_BOX(PG_FUNCTION_ARGS);
 Datum LWGEOM_envelope(PG_FUNCTION_ARGS);
+Datum LWGEOM_isempty(PG_FUNCTION_ARGS);
 
 // internal
 char * lwgeom_summary_recursive(char *serialized, int offset);
@@ -2336,3 +2337,13 @@ Datum LWGEOM_envelope(PG_FUNCTION_ARGS)
 	
 	PG_RETURN_POINTER(result);
 }
+
+PG_FUNCTION_INFO_V1(LWGEOM_isempty);
+Datum LWGEOM_isempty(PG_FUNCTION_ARGS)
+{
+	LWGEOM *geom = (LWGEOM *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
+
+	if ( lwgeom_getnumgeometries(SERIALIZED_FORM(geom)) == 0 )
+		PG_RETURN_BOOL(TRUE);
+	PG_RETURN_BOOL(FALSE);
+}
diff --git a/lwgeom/lwgeom_inout.c b/lwgeom/lwgeom_inout.c
index ac542cba5..053fe2fab 100644
--- a/lwgeom/lwgeom_inout.c
+++ b/lwgeom/lwgeom_inout.c
@@ -189,7 +189,7 @@ Datum WKBFromLWGEOM(PG_FUNCTION_ARGS)
 	char *lwgeom_input = (char *)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
 
 	// SRID=#;<hexized wkb>
-	char *hexized_wkb_srid =unparse_WKB(lwgeom_input,palloc_fn,free_fn);
+	char *hexized_wkb_srid = unparse_WKB(lwgeom_input,palloc_fn,free_fn);
 
 	char *hexized_wkb; // hexized_wkb_srid w/o srid
 	char *result; //wkb
diff --git a/lwgeom/lwpostgis.sql.in b/lwgeom/lwpostgis.sql.in
index c32396c3f..7d80bae14 100644
--- a/lwgeom/lwpostgis.sql.in
+++ b/lwgeom/lwpostgis.sql.in
@@ -968,6 +968,11 @@ CREATEFUNCTION IsClosed(geometry)
 	AS '@MODULE_FILENAME@', 'LWGEOM_isclosed_linestring'
 	LANGUAGE 'C' WITH (isstrict);
 
+CREATEFUNCTION IsEmpty(geometry)
+	RETURNS boolean
+	AS '@MODULE_FILENAME@', 'LWGEOM_isempty'
+	LANGUAGE 'C' WITH (isstrict);
+
 CREATEFUNCTION SRID(geometry) 
 	RETURNS int4
 	AS '@MODULE_FILENAME@','LWGEOM_getSRID'
-- 
2.40.0