title: Passing varying array from vertex to geometry shader on Mac
body: <p>I'd like to be able to pass an arbitrary number of varying values per vertex from the vertex shader to the geometry shader. I know that OpenGL has no dynamic arrays, so the number should be specified at compile time. The whole thing should run on an Apple MacBook with a NVIDIA GeForce 9400M graphics card and a driver that only offers OpenGL 2.1, along with some extensions.</p>
  
  <p>The problem here seems to be that the geometry shader takes its input in the form or an array with one element per vertex. As far as I can tell, there are no arrays of arrays available in my setup, and no arrays of interface blocks containing arrays either. So far, the best solution I could come up with is specifying a number of variables to pass this information, extracted from an array in the vertex shader and turned back into an array with a certain stride length in the geometry shader. That way, access to the values can still be performed using computed indices.</p>
  
  <p>Is there a better, more elegant way?</p>