title: OpenGL color index mode not working, color map has size 0
body: <p>I am learning some OpenGL through <a href="http://www.glprogramming.com/red/" rel="nofollow">this guide</a> and I have arrived at an example that uses color index mode. In Chapter 6, example 6-4 establishes antialising of lines in color-index mode. I wrote the code in and compiled it. The code runs but the problem is that the lines that should be colored are just white. I stuck this line in my init() function:</p>
  
  <pre><code>printf("The size of the color map is %d entries\n", glutGet(GLUT_WINDOW_COLORMAP_SIZE));
  </code></pre>
  
  <p>which printed "The size of the color map is 0 entries"</p>
  
  <p>Did I intialize somethign wrong or does my implementation of OpenGL really not have any color-index color map entries? Is it so unused? Is that strange?</p>