 operation that,
            when enabled,
            is applied between the incoming RGBA color
            and the RGBA color at the corresponding location in the
            frame buffer.
            To enable or disable the logical operation, call
            <a class="citerefentry" href="glEnable"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a> and <a class="citerefentry" href="glDisable"><span class="citerefentry"><span class="refentrytitle">glDisable</span></span></