title: OpenGL draw rectangle composed of lines with vertex array
body: <p>So I have a vertex array batcher, and I want to use it to render rectangles that are lines instead of filled in. Currently I am using <code>glPolyGonMode()</code>, but since my "shapes" are all uploaded to the graphics card as triangles, I get a line running down the middle of my rectangle, like this:<img src="https://i.stack.imgur.com/aLSsA.png" alt="enter image description here"></p>
  
  <p>Obviously this is happening because there are two triangles to a rectangle. But I want to render only the rectangle without the middle line. How could I accomplish this?</p>