title: Use OpenGL without a window
body: <p>I want to use the nice z-buffer functions of OpenGL, but I really don't want my program to open a window each time it runs (because I want it run as fast as possible).</p>
  
  <p>I am quite new to OpenGL, and I followed the tutorial to learn it. In the tutorial every example starts with:</p>
  
  <ol>
  <li>initialize GLFW</li>
  <li>open a window</li>
  <li>initialize GLEW</li>
  <li>the real stuff</li>
  </ol>
  
  <p>So I was thinking: hmm, since I only want to keep the real stuff, let's get rid of step 1-3. --I ended up with "segmentation error"</p>
  
  <p>Then I was thinking: well, maybe GLEW is related to my real stuff, but GLFW, by its name, only does the window stuff. So I tried deleting step 1, and deleting step 1-2. --Both gave me a "failed to initialize GLEW"</p>
  
  <p>Now I'm confused... What should I do?</p>