Ask HN: A technical write-up of the original QuickDraw region algorithms?

So this is maybe more of a rant than a question, but I just spent almost an hour trying and failing to find a blog that I read a few years ago. It had multiple articles explaining how Bill Atkinson's famous QuickDraw regions worked (maybe also including how he did the roundrect thing), and how they allowed for fast graphics on early Apple machines.

It's not any of these links [0][1][2][3][4][5], although admittedly they probably already got me 80% of the way of what there is to understand about regions. And I know the original source code has been released[6], but since I can't read 68K assembly that's not going to help me unless I turn this into a long-term project.

I'm honestly a bit surprised by this. Plenty of articles gushing about how important these algorithms were to the success of Apple and why they were patented, lots of PDFs of original manuals, old forum discussions on the expiration of patents, but no detailed articles that try to give a detailed explanation of how it all worked? It kind of feels like preserving history by saving the marketing but not the product itself.

So my slightly upset rant aside, I'm kind of hoping that I'm just unlucky with search engines getting worse at finding these type of technical articles with a niche audience. Does anyone remember the blog posts I was talking about and happen to have them bookmarked?

[0] https://www.folklore.org/StoryView.py?project=Macintosh&stor...

[1] https://www.folklore.org/StoryView.py?story=Round_Rects_Are_...

[1] http://basalgangster.macgui.com/RetroMacComputing/The_Long_V...

[3] https://www.info-mac.org/viewtopic.php?t=17328

[4] http://wg20.criticalcodestudies.com/index.php?p=/discussion/...

[5] http://www.verycomputer.com/275_4a6b5f879a8d4eab_1.htm

[6] www.computerhistory.org/highlights/macpaint/