e class="varname">gl_out[]</code>
            array, in the case of the tessellation control shader)
            is undefined after the vertex, tessellation control, and tessellation evaluation
            shading stages if the corresponding shader executable does
            not write to gl_ClipDistance. It is also undefined after the geometry processing stage if the geometry shader executable calls
            <a class="citerefentry" href="EmitVertex"><span class="citerefentry"><span class="refentrytitle"