I threw in a quick little feature to make the display of solid links more interesting.
The links with three connectors are drawn a little larger than the two-connector links. It would have been cool if I could figure out how the links all connected and alternated the sizes. Then that effect that you can see at connector F (middle left) would be seen at places like connector B (upper right). Still, this is nice and makes the mechanism look a little more refined where it does show up.
This took two lines of code so I think that I will leave it in. I don’t design things that are solid but someone might and this might help them.
Now if I can only fix the design flaw in the program where the selection of links is handled by the mechanism document but that code has no information about the nature of a solid link. That code does not know how things are displayed so a user must still click with the mouse along the invisible line between connectors to select a solid link.