lwgeom_unaryunion()

LWGEOM* lwgeom_unaryunion

(

const LWGEOM *

geom1

)

Definition at line 689 of file liblwgeom/lwgeom_geos.c.

References LWGEOM::flags, FLAGS_GET_Z, GEOS2LWGEOM(), LWDEBUGF, lwerror(), LWGEOM2GEOS(), lwgeom_clone_deep(), lwgeom_geos_errmsg, lwgeom_geos_error(), lwgeom_is_empty(), lwnotice(), and LWGEOM::srid.

Referenced by lwt_AddLine(), and ST_UnaryUnion().

{
        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_deep(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 ;
}

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