Bill: As to speed testing, I noticed the same things you did. I would swap out tests to offset that. Stupid Windows was preparing an update yesterday, which was messing up things in the background, for instance.
Naming: I wonder how many will fail to realize this puppy makes circles, too? Sure, a circle is just an degenerate ellipse, every community has one, but what else do we have to call it, oval? Hey, how about OVAL FILL? Wait, The Oval Team sounds too much like a 1960s drink option. Oval is more for egg shaped drawings, anyway. Naming things is a real botch sometimes.I like the flatellipsefill name in the current sub calls, except for the possible confusion with... "Well, where's the round ellipse function?"
Other Features: If we threw in a SELECT CASE and an extra parameter, we could include Bill's tilt-a-swirl formula in the non-default case. Zero, the default goes to flat ellipse, while any degree passed goes to CASE ELSE and results in the tilt formula being used. I don't know how much adding SELECT CASE and passing an extra parameter would affect the speed.
Anyway, just some stuff to consider for anyone pressing on...
What I know for sure is after several tests, it doesn't matter how much we try an tweak the one we are concentrating on now, Bill's with modified variable types with loops replacing for/next, and Bill's modified with my SQR replacing the inner loop, both run about the same. That was also true when I added varying sized ellipses to Mark's test program. I thought varying the sizes might show one outperformed but no. The testing, did however, show that Mark's SQR (which he already deduced ran slower), Steve' find, and Vince's modified Steve's find always ran considerably slower. That would probably be even more evident on my machine, because it has a tiny cpu. Hey, it's how it uses it that counts!
I would be for using Bill's modified with or without the SQR modification. What do you guys think about that, the naming, and keeping this just as a "flat" ellipse fill or including a tilt option, if that's OK with Bill? Also, if anyone has any disagreement with my statements, let me have it! I like to provoke thought... my wife says I could leave the thought part off, but you know...
Pete