title: OpenGL: Weird transparency blending result
body: <p>I'm working on creating a transparent GUI in OpenGL, and am trying to get text rendered over some semi-transparent quads, but the results are odd.</p>
  
  <p>If I render the text by itself, with nothing behind it, it looks fine:</p>
  
  <p><img src="https://i.stack.imgur.com/slVex.jpg" alt="Text without transparent background"></p>
  
  <p>However, if I render a semi-transparent quad behind it (rendering the quad before rendering the text), I get this:</p>
  
  <p><img src="https://i.stack.imgur.com/1znIu.jpg" alt="Text with transparent background"></p>
  
  <p>I have blending set to (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA). The font texture is an all-white texture with the character shapes in the alpha channel.</p>
  
  <p>Do I need to be doing something special when performing alpha-transparency over an existing layer of transparency? Or is there something else I need to check?</p>