al value is <code class="constant">GL_KEEP</code>.
                </p></dd><dt><span class="term"><em class="parameter"><code>dpfail</code></em></span></dt><dd><p>
                    Specifies the stencil action when the stencil test passes,
                    but the depth test fails.
                    <em class="parameter"><code>dpfail</code></em> accepts the same symbolic constants as <em class="parameter"><code>sfail</code></em>. The initial value
                    is <code class="constant">GL_KE