  16 or 256. If <em class="parameter"><code>level</code></em> is 0, only one mip-level
        of texture indices is described in <em class="parameter"><code>data</code></em>. Otherwise,
        the negative value of <em class="parameter"><code>level</code></em>
        specifies up to which mip-level the texture indices are described.
        A possibly remaining pad nibble for the lowest resolution
        mip-level is ignored.</p></div><div class="refsect1" title="Notes"><a id="notes"></a><h2>Notes</h2><