LWGEOM_makeline_garray()

Datum LWGEOM_makeline_garray

(

PG_FUNCTION_ARGS

)

Definition at line 1389 of file lwgeom_functions_basic.c.

{
        ArrayType *array;
        int nelems;
        GSERIALIZED *result = NULL;
        LWGEOM **geoms;
        LWGEOM *outlwg;
        uint32 ngeoms;
        int srid = SRID_UNKNOWN;
 
        ArrayIterator iterator;
        Datum value;
        bool isnull;
 
        POSTGIS_DEBUGF(2, "%s called", __func__);
 
        /* Return null on null input */
        if ( PG_ARGISNULL(0) )
                PG_RETURN_NULL();
 
        /* Get actual ArrayType */
        array = PG_GETARG_ARRAYTYPE_P(0);
 
        /* Get number of geometries in array */
        nelems = ArrayGetNItems(ARR_NDIM(array), ARR_DIMS(array));
 
        POSTGIS_DEBUGF(3, "%s: array has %d elements", __func__, nelems);
 
        /* Return null on 0-elements input array */
        if ( nelems == 0 )
                PG_RETURN_NULL();
 
 
        /*
         * Deserialize all point geometries in array into the
         * geoms pointers array.
         * Count actual number of points.
         */
 
        /* possibly more then required */
        geoms = palloc(sizeof(LWGEOM *) * nelems);
        ngeoms = 0;
 
#if POSTGIS_PGSQL_VERSION >= 95
        iterator = array_create_iterator(array, 0, NULL);
#else
        iterator = array_create_iterator(array, 0);
#endif
 
        while( array_iterate(iterator, &value, &isnull) )
        {
                GSERIALIZED *geom;
 
                if ( isnull )
                        continue;
 
                geom = (GSERIALIZED *)DatumGetPointer(value);
 
                if ( gserialized_get_type(geom) != POINTTYPE &&
                     gserialized_get_type(geom) != LINETYPE &&
                     gserialized_get_type(geom) != MULTIPOINTTYPE)
                {
                        continue;
                }
 
                geoms[ngeoms++] = lwgeom_from_gserialized(geom);
 
                /* Check SRID homogeneity */
                if ( ngeoms == 1 )
                {
                        /* Get first geometry SRID */
                        srid = geoms[ngeoms-1]->srid;
                        /* TODO: also get ZMflags */
                }
                else
                {
                        error_if_srid_mismatch(geoms[ngeoms-1]->srid, srid);
                }
 
                POSTGIS_DEBUGF(3, "%s: element %d deserialized", __func__, ngeoms);
        }
        array_free_iterator(iterator);
 
        /* Return null on 0-points input array */
        if ( ngeoms == 0 )
        {
                /* TODO: should we return LINESTRING EMPTY here ? */
                elog(NOTICE, "No points or linestrings in input array");
                PG_RETURN_NULL();
        }
 
        POSTGIS_DEBUGF(3, "LWGEOM_makeline_garray: elements: %d", ngeoms);
 
        outlwg = (LWGEOM *)lwline_from_lwgeom_array(srid, ngeoms, geoms);
 
        result = geometry_serialize(outlwg);
 
        PG_RETURN_POINTER(result);
}

References error_if_srid_mismatch(), geometry_serialize(), gserialized_get_type(), LINETYPE, lwgeom_from_gserialized(), lwline_from_lwgeom_array(), MULTIPOINTTYPE, POINTTYPE, LWGEOM::srid, SRID_UNKNOWN, and genraster::value.

Referenced by pgis_geometry_makeline_finalfn().

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