P_ROWS</code>, and <code class="constant">GL_PACK_SKIP_IMAGES</code></span></dt><dd><p>
                        These values are provided as a convenience to the programmer;
                        they provide no functionality that cannot be duplicated simply by
                        incrementing the pointer passed to <a class="citerefentry" href="glReadPixels"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a>.
                        Setting <code class="constant">GL_