title: What does setting the GL color before doing a texture mapping operation do?
body: <p>I am looking at some sample code in a book that creates a jittered antialiasing effect by repeatedly rendering a scene (at different offsets) onto a offscreen texture, then using that texture to repeatedly draw a quad in the main view with some blend stuff set up.</p>
  
  <p>To accumulate the color "correctly", the code is setting the color like so:</p>
  
  <pre><code>glColor4f(f, f, f, 1);
  </code></pre>
  
  <p>where f is <code>1.0/number_of_samples</code>, and then binding the offscreen texture and rendering it.</p>
  
  <p>Since textures come with their own color and alpha data, what is the effect (mathematically and intuitively) that setting the overall "color" in advance achieves?</p>
  
  <p>Thanks.</p>