@user1118321 submitted an answer that was useful but did not answer my question exactly; I did not want to use anti-aliasing for the edge of the circle. I've thanked him and suggested that he submit a different answer if it interests him.
I am also interested in @Pikalek's as-yet unsubmitted answer as he mentioned using an alternative method using the mid-point algorithm.
I have since updated my original post with an update on my progress instead of submitting it as an answer, even though I think it would qualify as "an answer".
My questions are:
Pikalek played a role in my solution and I would acknowledge this in an answer if I submit one. It feels very rude but I do acknowledge his answer and state why it was insufficient. Is it acceptable to modify someone else's answer for my own and accept it when I also asked the question? The difference in code is subtle but the result is significant.
I submitted my solution as an update to my question instead of rushing to answer it myself to not discourage others from submitting their own. I'm effectively baiting more answers with a solution in reserve. Am I wrong to manage my question in this way? If a better solution comes along, I will accept that instead.
I suppose that, while I do have an answer, I'm not satisfied with it. And since it is my question, I feel that my actions are justified.
I'm seeking advice on whether I'm handled this situation appropriately.