title: Multisampling with triangles sharing the edge
body: <p>According to my understanding:</p>
  
  <p><strong>Multisampling</strong>:
  Consider we have primitive with 4X multisampling and only 1 sample is covered by primitive. So it calculates the percentage (pixel coverage based on how many samples passed the test) i.e. 25% and blends with the background color and we get blended color for that pixel which is copied to all the 4 samples when fragment shader is executed. </p>
  
  <p><strong>Antialiasing:</strong>
  OpenGL calculates the amount of a pixel that is covered by a primitive (point, line, or triangle) and uses it to generate an alpha value for each fragment. This alpha value is multiplied by the alpha value of the fragment produced by your shader and so has an effect on blending when either the source or destination blend factor includes the source alpha term.</p>
  
  <p>Please correct me it is wrong. </p>
  
  <p>In case of multisampling we get 50-50 blend but with anti-aliasing we get 25-25-50 blend, hows that?</p>
  
  <p>In case of multisampling when we render one triangle it will update the FBO with 25-75 pixel color and when second triangle being rendered it will blend with the background color, so we should get background color instead of 50-50, but this is not the case. </p>
  
  <p>Here by multisampling, I meant to say enabling it with glEnable(GL_MULTISAMPLE) and by antialiasing, i meant enabling it with GL_POLYGON_SMOOTH</p>