On Sat, Jan 9, 2010 at 4:41 AM, Frederik Ramm <frede...@remote.org> wrote:
> Now either we provide that information, by making a rule and hoping > everyone understands and adheres to it (unlikely), or else we just try and > keep our nodes close enough to each other because that will then reduce the > error introduced by the ambiguity discussed above, to something that we do > not have to care about. > FWIW, I think we should do both. And, thinking about it a bit, I guess the proper rule is that (10, 10) -> (30, 30) passes through (20, 20), since it's completely unrealistic to assume that the basic renderers will do otherwise. My understanding is that this is equivalent to say saying that the line is "straight in the Mercator projection", as my understanding is that the Mercator projection represents each pixel as a fixed length and width in degrees. And what that also means is that a straight line on earth which is more than a certain length is not properly represented by a way with two points. --- One thing I can't quite get my mind wrapped around is whether or not a geodesic is what we'd call a straight line on the earth. If we put a few million (?) rulers end-to-end as best we could, would that form a geodesic, and if not, what would it form? I'm fairly certain it wouldn't pass (10, 10) -> (30, 30) through (20, 20), since 20 degrees of longitude does not (generally) equal 20 degrees of latitude in length. But I'm not sure if it'd be a geodesic or not. I'd love for someone to answer that question and provide a link or source to back up their answer.
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