          <span class="term">
                <code class="constant">GL_FRAMEBUFFER_BARRIER_BIT</code>
              </span>
            </dt>
            <dd>
              <p>
                        Reads and writes via framebuffer object
                        attachments after the barrier will reflect data written by shaders
                        prior to the barrier.  Additionally, framebuffer writes issued after
                        the barrier will wait on the completion of all shader writes i