lwpoly_from_wkb_state()

static LWPOLY* lwpoly_from_wkb_state ( wkb_parse_state *  s )

static

POLYGON Read a WKB polygon, starting just after the endian byte, type number and optional srid number.

Advance the parse state forward appropriately. First read the number of rings, then read each ring (which are structured as point arrays)

Definition at line 502 of file lwin_wkb.c.

References wkb_parse_state::check, wkb_parse_state::has_m, wkb_parse_state::has_z, integer_from_wkb_state(), LW_FAILURE, LW_PARSER_CHECK_CLOSURE, LW_PARSER_CHECK_MINPOINTS, LWDEBUG, LWDEBUGF, lwerror(), lwpoly_add_ring(), lwpoly_construct_empty(), wkb_parse_state::lwtype, lwtype_name(), POINTARRAY::npoints, ptarray_from_wkb_state(), ptarray_is_closed_2d(), and wkb_parse_state::srid.

Referenced by lwgeom_from_wkb_state().

{
        uint32_t nrings = integer_from_wkb_state(s);
        int i = 0;
        LWPOLY *poly = lwpoly_construct_empty(s->srid, s->has_z, s->has_m);

        LWDEBUGF(4,"Polygon has %d rings", nrings);

        /* Empty polygon? */
        if( nrings == 0 )
                return poly;

        for( i = 0; i < nrings; i++ )
        {
                POINTARRAY *pa = ptarray_from_wkb_state(s);
                if( pa == NULL )
                        continue;

                /* Check for at least four points. */
                if( s->check & LW_PARSER_CHECK_MINPOINTS && pa->npoints < 4 )
                {
                        LWDEBUGF(2, "%s must have at least four points in each ring", lwtype_name(s->lwtype));
                        lwerror("%s must have at least four points in each ring", lwtype_name(s->lwtype));
                        return NULL;
                }

                /* Check that first and last points are the same. */
                if( s->check & LW_PARSER_CHECK_CLOSURE && ! ptarray_is_closed_2d(pa) )
                {
                        LWDEBUGF(2, "%s must have closed rings", lwtype_name(s->lwtype));
                        lwerror("%s must have closed rings", lwtype_name(s->lwtype));
                        return NULL;
                }

                /* Add ring to polygon */
                if ( lwpoly_add_ring(poly, pa) == LW_FAILURE )
                {
                        LWDEBUG(2, "Unable to add ring to polygon");
                        lwerror("Unable to add ring to polygon");
                }

        }
        return poly;
}

Here is the call graph for this function:

Here is the caller graph for this function: