Comment 4 for bug 166252

I will follow your advice to work around the problem.

But there is something I really do not understand. My
squares are almost of the same color and touching each
other. With AA, their borders should merge. Yet, instead
we see a gap made of the background color between the
squares. Somehow, I feel that this is a AA bug.

AA might generate shaggy borders, but the other "side" of
the border should have the color of the other object, not
the background color which is in theory totally hidden by
the two objects touching themselves.

In other words, AA should not even let these gaps appear in
the first place. So the question is, why AA merge the
borders with the background instead of the adjacent object?

I wish I had the time to get involve with this because
somehow, I feel that a solution for straight lines touching
themselves would be possible. When an object is droped, its
border is checked against its neighbourghs and borders that
meet are recorded. When rendering time comes, on these
borders AA is applied using the colors of the two objects,
not that of the background. I do not see how gaps would
show up in that scenario.

I agree that curves are difficult. But for straight lines,
this should be possible and I bet most people suffering of
this problem have them with straight lines anyway. If the
problem is solved only for straight lines, its still a major
improvement.