160;    buffer_t&amp; buffer() { <span class="keywordflow">return</span> _row_buffer; }</div><div class="line"><a name="l00158"></a><span class="lineno">  158</span>&#160;</div><div class="line"><a name="l00159"></a><span class="lineno">  159</span>&#160;<span class="keyword">private</span>:</div><div class="line"><a name="l00160"></a><span class="lineno">  160</span>&#160;</div><div class="line"><a name="l00161"></a><span class="lineno">  161</span>&#160;    <span class="comment">// For instance 25 pixels 