title: Adapt existing code for OpenGL stereoscopic rendering?
body: <p>I'm trying to implement stereoscopic 3d in OpenGL using a side-by-side technique.</p>
  
  <p>I've read <a href="http://local.wasp.uwa.edu.au/~pbourke/miscellaneous/stereographics/stereorender/" rel="nofollow">this article</a> which in great detail explains how to set up the camera for left and right views. It uses a camera model and set up the left and right views using gluLookAt. </p>
  
  <p>However in my case I want to <strong>adapt existing code that already set up the projection</strong>.</p>
  
  <p>See the following example where "existingcode" represents the code that I cannot make changes to.</p>
  
  <pre><code>//Render left view
  
  // setUpCamera set the gl projection and model matrix
  existingcode.setUpCamera()
  
  ..
  here I want to somehow modify the current gl projection matrix for the left view
  ..
  
  existingcode.renderScene()
  
  //.. then render right view
  </code></pre>
  
  <p>Can it be done, perhaps by calling glGetMatrix and modify it somehow?</p>