 and <em class="parameter"><code>y</code></em> screen coordinates correspond to lower
        <em class="parameter"><code>s</code></em> and <em class="parameter"><code>t</code></em> texture
        coordinates.</p><p>If any of the pixels within the specified rectangle of
        the color buffer are outside the window associated with the
        current rendering context, then the values obtained for those
        pixels are undefined.</p></div><div class="refsect1" title="Notes"><a id="notes"></a><h2>Notes