title: GLSL sampler2DShadow deprecated past version 120? What to use?
body: <p>I've been trying to implement percentage closer filtering for my shadow mapping as described here <a href="http://http.developer.nvidia.com/GPUGems/gpugems_ch11.html" rel="nofollow">Nvidia GPU Gems</a></p>
  
  <p>When I try to sample my shadow map using a uniform sampler2DShadow and shadow2D or shadow2DProj the GLSL compile fails and gives me the error </p>
  
  <pre><code>shadow2D deprecated after version 120
  </code></pre>
  
  <p>How would I go about implementing an equivalent solution in GLSL 330+? I'm currently just using a binary texture sample along with Poisson Sampling but the staircase aliasing is pretty bad.</p>