title: glPoint Alpha Blending issue
body: <p>I am having issues alpha blending glPoints. The alpha blending works correctly when the glPoint is over the background but when a glPoint overlaps another glPoint the background color is visible rather then the underlying glPoint.</p>
  
  <p><img src="https://i.stack.imgur.com/bdlin.png" alt="enter image description here"></p>
  
  <pre><code>// create texture
  
      GLuint tex;
      glGenTextures(1, &amp;tex);
      glBindTexture(GL_TEXTURE_2D, tex);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
      glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, spriteData);
  
      // Draw
  
      glEnable(GL_DEPTH_TEST);
      glEnable(GL_BLEND);
      glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
      glBindTexture(GL_TEXTURE_2D, tex);
      ....
      glDrawArrays(GL_POINTS, 0, numberOfPoints);
  
      // Frag Shader
  
      uniform sampler2D Texture; 
  
      void main(void) 
      {
          gl_FragColor = texture2D(Texture, gl_PointCoord); 
      }
  </code></pre>
  
  <p>What am i doing wrong?</p>