From: Sandro Santilli <strk@keybit.net>
Date: Wed, 19 Aug 2015 10:52:19 +0000 (+0000)
Subject: Add lwgeom_unaryunion to liblwgeom
X-Git-Tag: 2.2.0rc1~144
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c50e8ff6f835805e112f3f424f675a227706e937;p=postgis

Add lwgeom_unaryunion to liblwgeom

Includes postgis change to use liblwgeom version

git-svn-id: http://svn.osgeo.org/postgis/trunk@13941 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/NEWS b/NEWS
index 201e7fc9d..91210da25 100644
--- a/NEWS
+++ b/NEWS
@@ -35,6 +35,7 @@ PostGIS 2.2.0
 
   - Topology API in liblwgeom
     (Sandro Santilli / Regione Toscana - SITA)
+  - New lwgeom_unaryunion method in liblwgeom
   - New lwgeom_linemerge method in liblwgeom
   - New lwgeom_is_simple method in liblwgeom
   - #3117, Add SFCGAL 1.1 support: add ST_3DDifference, ST_3DUnion,
diff --git a/liblwgeom/liblwgeom.h.in b/liblwgeom/liblwgeom.h.in
index 16584e610..574fe5cd2 100644
--- a/liblwgeom/liblwgeom.h.in
+++ b/liblwgeom/liblwgeom.h.in
@@ -2047,6 +2047,7 @@ LWGEOM *lwgeom_difference(const LWGEOM *geom1, const LWGEOM *geom2);
 LWGEOM *lwgeom_symdifference(const LWGEOM* geom1, const LWGEOM* geom2);
 LWGEOM *lwgeom_union(const LWGEOM *geom1, const LWGEOM *geom2);
 LWGEOM *lwgeom_linemerge(const LWGEOM *geom1);
+LWGEOM *lwgeom_unaryunion(const LWGEOM *geom1);
 LWGEOM *lwgeom_clip_by_rect(const LWGEOM *geom1, double x0, double y0, double x1, double y1);
 LWCOLLECTION *lwgeom_subdivide(const LWGEOM *geom, int maxvertices);
 
diff --git a/liblwgeom/lwgeom_geos.c b/liblwgeom/lwgeom_geos.c
index 4394fbb25..dc6052c42 100644
--- a/liblwgeom/lwgeom_geos.c
+++ b/liblwgeom/lwgeom_geos.c
@@ -679,6 +679,58 @@ lwgeom_linemerge(const LWGEOM *geom1)
 	return result ;
 }
 
+LWGEOM *
+lwgeom_unaryunion(const LWGEOM *geom1)
+{
+	LWGEOM *result ;
+	GEOSGeometry *g1, *g3 ;
+	int is3d = FLAGS_GET_Z(geom1->flags);
+	int srid = geom1->srid;
+
+	/* Empty.UnaryUnion() == Empty */
+	if ( lwgeom_is_empty(geom1) )
+		return lwgeom_clone(geom1);
+
+	initGEOS(lwnotice, lwgeom_geos_error);
+
+	g1 = LWGEOM2GEOS(geom1, 0);
+	if ( 0 == g1 )   /* exception thrown at construction */
+	{
+		lwerror("First argument geometry could not be converted to GEOS: %s", lwgeom_geos_errmsg);
+		return NULL ;
+	}
+
+	g3 = GEOSUnaryUnion(g1);
+
+	if (g3 == NULL)
+	{
+		GEOSGeom_destroy(g1);
+		lwerror("Error performing unaryunion: %s",
+		        lwgeom_geos_errmsg);
+		return NULL; /* never get here */
+	}
+
+	LWDEBUGF(3, "result: %s", GEOSGeomToWKT(g3) ) ;
+
+	GEOSSetSRID(g3, srid);
+
+	result = GEOS2LWGEOM(g3, is3d);
+
+	if (result == NULL)
+	{
+		GEOSGeom_destroy(g1);
+		GEOSGeom_destroy(g3);
+		lwerror("Error performing unaryunion: GEOS2LWGEOM: %s",
+		        lwgeom_geos_errmsg);
+		return NULL ; /* never get here */
+	}
+
+	GEOSGeom_destroy(g1);
+	GEOSGeom_destroy(g3);
+
+	return result ;
+}
+
 LWGEOM *
 lwgeom_difference(const LWGEOM *geom1, const LWGEOM *geom2)
 {
diff --git a/postgis/lwgeom_geos.c b/postgis/lwgeom_geos.c
index 5d473db52..576f91040 100644
--- a/postgis/lwgeom_geos.c
+++ b/postgis/lwgeom_geos.c
@@ -736,75 +736,24 @@ Datum pgis_union_geometry_array(PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1(ST_UnaryUnion);
 Datum ST_UnaryUnion(PG_FUNCTION_ARGS)
 {
-#if POSTGIS_GEOS_VERSION < 33
-	PG_RETURN_NULL();
-	lwpgerror("The GEOS version this PostGIS binary "
-	        "was compiled against (%d) doesn't support "
-	        "'GEOSUnaryUnion' function (3.3.0+ required)",
-	        POSTGIS_GEOS_VERSION);
-	PG_RETURN_NULL();
-#else /* POSTGIS_GEOS_VERSION >= 33 */
 	GSERIALIZED *geom1;
-	int is3d;
-	int srid;
-	GEOSGeometry *g1, *g3;
 	GSERIALIZED *result;
-
-	POSTGIS_DEBUG(2, "in ST_UnaryUnion");
+	LWGEOM *lwgeom1, *lwresult ;
 
 	geom1 = PG_GETARG_GSERIALIZED_P(0);
 
-	/* UnaryUnion(empty) == (empty) */
-	if ( gserialized_is_empty(geom1) )
-		PG_RETURN_POINTER(geom1);
-
-	is3d = ( gserialized_has_z(geom1) );
-
-	srid = gserialized_get_srid(geom1);
-
-	initGEOS(lwpgnotice, lwgeom_geos_error);
-
-	g1 = (GEOSGeometry *)POSTGIS2GEOS(geom1);
-
-	if ( 0 == g1 )   /* exception thrown at construction */
-	{
-		HANDLE_GEOS_ERROR("First argument geometry could not be converted to GEOS");
-		PG_RETURN_NULL();
-	}
-
-	POSTGIS_DEBUGF(3, "g1=%s", GEOSGeomToWKT(g1));
-
-	g3 = GEOSUnaryUnion(g1);
-
-	POSTGIS_DEBUGF(3, "g3=%s", GEOSGeomToWKT(g3));
 
-	GEOSGeom_destroy(g1);
-
-	if (g3 == NULL)
-	{
-		HANDLE_GEOS_ERROR("GEOSUnion");
-		PG_RETURN_NULL(); /* never get here */
-	}
-
-
-	GEOSSetSRID(g3, srid);
-
-	result = GEOS2POSTGIS(g3, is3d);
-
-	GEOSGeom_destroy(g3);
+	lwgeom1 = lwgeom_from_gserialized(geom1) ;
 
-	if (result == NULL)
-	{
-		elog(ERROR, "ST_UnaryUnion failed converting GEOS result Geometry to PostGIS format");
-		PG_RETURN_NULL(); /*never get here */
-	}
+	lwresult = lwgeom_unaryunion(lwgeom1);
+	result = geometry_serialize(lwresult) ;
 
-	/* compressType(result); */
+	lwgeom_free(lwgeom1) ;
+	lwgeom_free(lwresult) ;
 
 	PG_FREE_IF_COPY(geom1, 0);
 
 	PG_RETURN_POINTER(result);
-#endif /* POSTGIS_GEOS_VERSION >= 33 */
 }