title: Combine Two Translucent Unpremultiplied Textures in Open GL With Blend Modes?
body: <p>I'm trying to figure out how to use Open GL to combine two unpremultiplied textures (one on top of the other). </p>
  
  <p>Both textures have areas with 0-alpha.  I'd like the combined result to be unpremultiplied as well.  I've tried multiple combinations of GL_ONE, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, etc but haven't had any luck yet.</p>
  
  <p>Here's what I mean (Texture1 and Texture2 are the input textures, Combo is the desired combination):</p>
  
  <p><img src="https://i.stack.imgur.com/0YAvA.png" alt="enter image description here"></p>