LWGEOM_interiorringn_polygon()

Datum LWGEOM_interiorringn_polygon

(

PG_FUNCTION_ARGS

)

Definition at line 460 of file lwgeom_ogc.c.

{
        GSERIALIZED *geom;
        int32 wanted_index;
        LWCURVEPOLY *curvepoly = NULL;
        LWPOLY *poly = NULL;
        POINTARRAY *ring;
        LWLINE *line;
        LWGEOM *lwgeom;
        GSERIALIZED *result;
        GBOX *bbox = NULL;
        int type;
 
        POSTGIS_DEBUG(2, "LWGEOM_interiorringn_polygon called.");
 
        wanted_index = PG_GETARG_INT32(1);
        if ( wanted_index < 1 )
        {
                PG_RETURN_NULL(); /* index out of range */
        }
 
        geom = PG_GETARG_GSERIALIZED_P(0);
        type = gserialized_get_type(geom);
 
        if ( (type != POLYGONTYPE) && (type != CURVEPOLYTYPE) )
        {
                PG_FREE_IF_COPY(geom, 0);
                PG_RETURN_NULL();
        }
 
        lwgeom = lwgeom_from_gserialized(geom);
        if( lwgeom_is_empty(lwgeom) )
        {
                lwpoly_free(poly);
                PG_FREE_IF_COPY(geom, 0);
                PG_RETURN_NULL();
        }
 
        if ( type == POLYGONTYPE)
        {
                poly = lwgeom_as_lwpoly(lwgeom_from_gserialized(geom));
 
                /* Ok, now we have a polygon. Let's see if it has enough holes */
                if ( wanted_index >= (int32)poly->nrings )
                {
                        lwpoly_free(poly);
                        PG_FREE_IF_COPY(geom, 0);
                        PG_RETURN_NULL();
                }
 
                ring = poly->rings[wanted_index];
 
                /* COMPUTE_BBOX==TAINTING */
                if ( poly->bbox )
                {
                        bbox = lwalloc(sizeof(GBOX));
                        ptarray_calculate_gbox_cartesian(ring, bbox);
                }
 
                /* This is a LWLINE constructed by interior ring POINTARRAY */
                line = lwline_construct(poly->srid, bbox, ring);
 
 
                result = geometry_serialize((LWGEOM *)line);
                lwline_release(line);
                lwpoly_free(poly);
        }
        else
        {
                curvepoly = lwgeom_as_lwcurvepoly(lwgeom_from_gserialized(geom));
 
                if (wanted_index >= (int32)curvepoly->nrings)
                {
                        PG_FREE_IF_COPY(geom, 0);
                        lwgeom_release((LWGEOM *)curvepoly);
                        PG_RETURN_NULL();
                }
 
                result = geometry_serialize(curvepoly->rings[wanted_index]);
                lwgeom_free((LWGEOM*)curvepoly);
        }
 
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_POINTER(result);
}

References LWPOLY::bbox, CURVEPOLYTYPE, geometry_serialize(), gserialized_get_type(), lwalloc(), lwgeom_as_lwcurvepoly(), lwgeom_as_lwpoly(), lwgeom_free(), lwgeom_from_gserialized(), lwgeom_is_empty(), lwgeom_release(), lwline_construct(), lwline_release(), lwpoly_free(), LWPOLY::nrings, LWCURVEPOLY::nrings, POLYGONTYPE, ptarray_calculate_gbox_cartesian(), LWPOLY::rings, LWCURVEPOLY::rings, and LWPOLY::srid.

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