title: Is it possible to set GLSL variables in between operations?
body: <p>I am aiming at the following case:</p>
  
  <pre><code>bind shader
  set uniform variable
  ..draw box..
  set uniform variable to different value
  ..draw another box, with the new variable applied in the vertex shader..
  </code></pre>
  
  <p>Is it possible to set GLSL variables in between operations?</p>