lwgeom_count_rings()

uint32_t lwgeom_count_rings ( const LWGEOM *  geom )

extern

Count the total number of rings in any LWGEOM.

Multipolygons and other collections get counted, not the same as OGC st_numrings.

Count the total number of rings in any LWGEOM.

Definition at line 1339 of file lwgeom.c.

{
        int result = 0;
 
        /* Null? Empty? Zero. */
        if( ! geom || lwgeom_is_empty(geom) )
                return 0;
 
        switch (geom->type)
        {
        case POINTTYPE:
        case CIRCSTRINGTYPE:
        case COMPOUNDTYPE:
        case MULTICURVETYPE:
        case MULTIPOINTTYPE:
        case MULTILINETYPE:
        case LINETYPE:
                result = 0;
                break;
        case TRIANGLETYPE:
                result = 1;
                break;
        case POLYGONTYPE:
                result = ((LWPOLY *)geom)->nrings;
                break;
        case CURVEPOLYTYPE:
                result = ((LWCURVEPOLY *)geom)->nrings;
                break;
        case MULTISURFACETYPE:
        case MULTIPOLYGONTYPE:
        case POLYHEDRALSURFACETYPE:
        case TINTYPE:
        case COLLECTIONTYPE:
        {
                LWCOLLECTION *col = (LWCOLLECTION*)geom;
                uint32_t i = 0;
                for( i = 0; i < col->ngeoms; i++ )
                        result += lwgeom_count_rings(col->geoms[i]);
                break;
        }
        default:
                lwerror("lwgeom_count_rings: unsupported input geometry type: %s", lwtype_name(geom->type));
                break;
        }
        LWDEBUGF(3, "counted %d rings", result);
        return result;
}

References CIRCSTRINGTYPE, COLLECTIONTYPE, COMPOUNDTYPE, CURVEPOLYTYPE, LWCOLLECTION::geoms, LINETYPE, LWDEBUGF, lwerror(), lwgeom_count_rings(), lwgeom_is_empty(), lwtype_name(), MULTICURVETYPE, MULTILINETYPE, MULTIPOINTTYPE, MULTIPOLYGONTYPE, MULTISURFACETYPE, LWCOLLECTION::ngeoms, POINTTYPE, POLYGONTYPE, POLYHEDRALSURFACETYPE, TINTYPE, TRIANGLETYPE, and LWGEOM::type.

Referenced by lwgeom_count_rings(), and LWGEOM_nrings().

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