title: Opengl uniform behaviour
body: <p>I've noticed some things that aren't well explained in the opengl docs. Please correct me if I'm wrong.</p>
  
  <ol>
  <li><p>You can't set the value of a uniform if the program isn't the one that opengl is using at that moment. That will generate an error.</p></li>
  <li><p>If you set the value of a uniform in program A, then switch to program B, then switch back to program A, the value stays. Is this reliable?</p></li>
  <li><p>There is no way to set a uniform value to a program that isn't being used at that moment. Is there a workaround?</p></li>
  </ol>