title: opengl es 2.0 alpha blending
body: <p>I'm using the following to enable alpha blending</p>
  
  <pre><code>glEnable(GL_BLEND);
  glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
  </code></pre>
  
  <p>The transparency is taken from a texture which seems to work, using the simplest of fragment shaders:</p>
  
  <pre><code>void main(void) {
    gl_FragColor = texture2D(texture, texCoordOut);
  }
  </code></pre>
  
  <p>While it blends nicely with the background color it doesn't work with other objects using the same alpha blending. I don't really know how to explain this so here's a picture:</p>
  
  <p><img src="https://i.stack.imgur.com/xwGkY.png" alt="alpha blending going wrong"></p>
  
  <p>What am I doing wrong?</p>