Always open to suggestions! I don't claim this to be any kind of novel method, or even a "good method". It's just an explanation of one way to do it, which is (IMO) relatively easy to understand, and implement.

When researching about this, I didn’t find a lot of writing. Macromedia definitely had this a long time ago, but I don't think you can look up how it was implemented. Not to my knowledge, at least.

Do you have an example of the algorithm you describe? Or a more detailed explanation? I don't quite get how it would work from what you've described.