 vec4 gl_Position;
        float gl_PointSize;
        float gl_ClipDistance[];
    };</pre>
        <p>
        </p>
      </div>
      <div class="refsect1" id="description">
        <h2>Description</h2>
        <p>
            In the vertex, tessellation evaluation and geometry languages, a single
            global instance of the <code class="varname">gl_PerVertex</code> named block is available and
            its <code class="varname">gl_PointSize</code> member is an output that receives the
        