Norman Vine writes:

 > 2) is a little more complicated but we allready have a good start
 >      if we leverage the Scenery directory structure

Agreed.

 >      I suggested using a quadtree for each 10x10 degree block
 >      but there are spherical indexing methods that might be better
 >      in that there is no cos(lat) shrink factor to account for when doing
 >      range lookups.

Remember Knuth's (?) warnings about premature optimization, though.
What are our use cases?  If this is only for warping when the user
wants to move to a new airport, then a 10 ms or even a 100 ms delay
might be acceptable, since it doesn't recur in the main loop.  In that
case, a simple linear search within the chunk and its neighbours is
probably acceptable; for that matter, a linear search through the
whole airport list wouldn't be that bad.

If, however, there's a reason that we'd want to redo the airport
search every frame or every few frames, like we do for the navaids,
then some kind of indexing will be essential.


All the best,


David

-- 
David Megginson, [EMAIL PROTECTED], http://www.megginson.com/

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