lwgeom_linemerge()

LWGEOM* lwgeom_linemerge

(

const LWGEOM *

geom1

)

Definition at line 683 of file liblwgeom/lwgeom_geos.c.

References COLLECTIONTYPE, LWGEOM::flags, FLAGS_GET_Z, GEOS2LWGEOM(), lwcollection_construct_empty(), LWDEBUG, LWDEBUGF, lwerror(), LWGEOM2GEOS(), lwgeom_geos_errmsg, lwgeom_geos_error(), lwgeom_has_m(), lwgeom_is_empty(), lwnotice(), and LWGEOM::srid.

Referenced by linemerge(), lwt_AddLine(), and test_geos_linemerge().

{
        LWGEOM *result ;
        GEOSGeometry *g1, *g3 ;
        int is3d = FLAGS_GET_Z(geom1->flags);
        int srid = geom1->srid;

        /* Empty.Linemerge() == Empty */
        if ( lwgeom_is_empty(geom1) )
                return (LWGEOM*)lwcollection_construct_empty( COLLECTIONTYPE, srid, is3d,
                                         lwgeom_has_m(geom1) );

        initGEOS(lwnotice, lwgeom_geos_error);

        LWDEBUG(3, "linemerge() START");

        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 ;
        }

        LWDEBUG(3, " constructed geometrys - calling geos");
        LWDEBUGF(3, " g1 = %s", GEOSGeomToWKT(g1));
        /*LWDEBUGF(3, "g1 is valid = %i",GEOSisvalid(g1)); */

        g3 = GEOSLineMerge(g1);

        LWDEBUG(3, " linemerge finished");

        if (g3 == NULL)
        {
                GEOSGeom_destroy(g1);
                lwerror("Error performing linemerge: %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 linemerge: GEOS2LWGEOM: %s",
                        lwgeom_geos_errmsg);
                return NULL ; /* never get here */
        }

        GEOSGeom_destroy(g1);
        GEOSGeom_destroy(g3);

        return result ;
}

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