title: Check if AlphaTest supported on a render system
body: <p>I have an application using on multi-platform and I want to check whether current <code>render system</code> support <code>AlphaTest</code> or not, usign <code>Ogre</code>.<br>
  I couldn't find the argument I need to pass to <code>hasCapability</code>.<br>
  any help?   </p>
  
  <p><strong>CODE:</strong></p>
  
  <pre><code>const RenderSystemCapabilities *caps = Root::getSingleton().getRenderSystem()-&gt;getCapabilities();
  bool AlphaTestSupport = caps-&gt;hasCapability(/*???*/);
  </code></pre>