Thu, 28 Dec 2023

Welcome to the Fediverse

— SjG @ 5:03 pm

I’ve hooked up this blog to the fediverse. The improved visibility will doubtless increase readership from none to the lofty realms of zero.

Posts will federate as posts/toots/notes from @admin. Presumably, comments/responses will propagate back somehow too. I could read the manual, but I’m just going to sit back and see what happens.

Sat, 9 Dec 2023

A Dead-Simple Slideshow

— SjG @ 12:30 pm

I have tens of thousands of photos I’ve taken over the years.

I think some of these photos are pretty good, but most are languishing unseen on random hard drives.

To share them, I’ve been a member of Flickr, I’ve posted on the late lamented Twitter, and I post some onto Mastodon. I’ve also created numerous gallery applications/server scripts/web sites (e.g., Statgal), but they’ve generally been clumsy or take too much work to maintain. So I’ve been working on a dumb PHP/JavaScript slideshow thing that will scan directories, cache the details, etc.

Here’s introducing PhotoSpinner. It’s a quick’n’dirty script to provide photos. It’s very simple and allows me to publish categories of pictures without a lot of effort. Source code’s at Codeberg.

Sat, 2 Dec 2023

Tilings and Rotations

— SjG @ 2:29 pm

My math is abandoning me. I started out with the design below, which can be used to tile a plane. My thought was that I would rotate the “blade-like” hexagonal elements, since their shapes mesh almost gear-like when rotated in opposite directions. Behind them, the pinwheels would also rotate in alternating directions.

Hexagonal-design with pinwheels and blade-like elements

It’s not hard to convert a hexagonal tiling into rectangle tiles that will evenly cover a plane. In this case, drawing a rectangle from the centers of the the blade-like elements at 2, 4, 8, and 10 o’clock will work. Ah, but not necessarily if the elements are rotating! The rotations won’t match up. I’d need to expand the pattern and cut a larger tile from the expanded pattern.

Of course, it also quickly became obvious that I need to consider it a triangular tiling, not the hexagonal tiling that was in my head. With a triangular tiling, I can’t have the blade-like elements rotating in opposite directions because you run into this problem:

Uh-oh! Odd number of elements can’t rotate in opposite directions.

Naturally, any odd-numbered circuit will have the same issue. But say we treat the center blade-like element from the initial design differently, and replace it with a different shape, say. The six elements around it could rotate in alternating directions.

Separate treatment of the hexagon’s center

You’ll no doubt see where this is going. With this design, I could tile the plane. But what if I wanted a variation of this where the center elements, different though they were, still rotated? I end up back with a variation on my triangle problem.

So after that, I briefly considered going back and altering the original design, but instead decided I didn’t want to animate it after all.


Filed in: