not as accurate.
If you need a deeper you can modify the parameters to
<code> glXChooseVisual</code> in your code.
</p>


<h2>3.3 Why Isn't depth buffering working at all?</h2>
<p>
Be sure you're requesting a depth buffered-visual.  If you set the MESA_DEBUG
environment variable it will warn you about trying to enable depth testing
when you don't have a depth buffer.
</p>
<p>Specifically, make sure <code>glutInitDisplayMode</code> is being called
with <code>GLUT_DEPTH</code> or <code>glXChooseVisual</code> 