I wanted to make a point about the flexibility of the system, so I present you with the letter “A” stamped into the terrain. Doing this required no code changes; just creating the brush texture (which I’ve pasted over the screenshot in the image), and editing two data files (one to tell the cursor how to use the image, and one to add it as an action bar button). All up, it took about five minutes. (About half as long as it took me to write this post)
I don’t imagine that anyone will actually want to create a world with the letter “A” stamped into the terrain. But this approach is extremely flexible, and should make it much easier for folks to customise the interface to make it more convenient for themselves and/or others.
Now I just need to make the GUI not be quite so terrible, visually.