Where did Toady ever say that the world that the game generates is meant to be a sphere?
The point of what I'm saying is that it's not meant to be the whole world, just a slice.
He's said that he would have made the world into a sphere, but programming anything but a rectangle would have been a serious pain.
However, more to my point, he's also said that it's not the whole world, but a region where populations walk in or out (moreso in the past), including the still very-much-observable fact that any new start of an Adventurer allows for a start as a "Human Outsider". Meaning, not from that region.
The quotes I was specifically thinking of were from one of the DF talks, I believe, but those things are frustratingly difficult to actually search if you can't precisely remember the terms, so I came up with a quote that was as close to the one I was thinking of as possible.
A flat projection of a sphere is somewhat tricky. You can't represent everything with a rectangle, anyway, not without distortion or tearing. You can't even do a portion of a sphere without distortion. So, the current world is distorted, if you assume it's spherical in the first place. Right now the edge blocks, but what did you want? If you wrap around the left/right edges, you have a cylindrical world. If you walk off the top, you have to decide where you want that to go as well, and you can either end up with a torus or some kind of weird projective space depending on how you define it, but you're not going to get a sphere if you want a rectangular map. An actual sphere would require significant revisions to world map storage and how it interprets the local maps in that space.<P>We have lots of land now because water is relatively pointless space. This can change when ships go in, yeah. It also doesn't simulate an entire world so that repopulation can occur from the edges and shores of edge-touching oceans. I haven't done the Life Cycles arc, but even after I do, world population will probably always have a downward trend if the world is self-contained, unless the game is relatively non-violent.
As for the intent to make a sphere, best evidence is to
see this older post.
The limits of the world are just set up the easy way right now. It would be very tricky to make the world a sphere, just because it is impossible to tile a sphere evenly with squares, so the current map storage system wouldn't work. Making the world a torus or a cylinder would be easier When I set up the universe/world parameters generator, the limits of the world could be any sort of thing -- just a mist that you walk into to go to a different world, or a drop-off into the void, whatever. Making the world round will be much harder.
It's meant to be as close to a spheric world as possible without screwing around with complex mechanics that wouldn't add too much to the game, anyway. (Unless Toady eventually wants to start having trade with "distant lands" you can't actually enter, and are just abstracted.)