Re: [Flightgear-devel] Global data positional lookup

[Mathias <Mat...@gm...>]

Hi David,

On Tuesday 21 February 2006 01:04, David Luff wrote:
> Thanks for all the suggestions guys.  I'm ashamed to say that I'd never
> heard of the kd tree or the quad-tree before.  Yes, the current bucket
> approach works, and yes I'll probably use it this time (Special User
> Airspace records for display on the kln89 map page), but the possibility =
of
> a more elegant approach is something that's been bugging me for a while.

It took a bit longer than expected, but here it is:
A map working on a hierarchical triangular mesh like described in the other=
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references in this thread.
It could be used just like a std::map with the addition that there is a=20
range_iterator and a const_range_iterator which can be used to iterate fast=
=20
over a small subset of the sphere.
There is a small test program included that I used to test for correctness,=
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that shows how that class could be used.
It can stand several improovements and there are some FIXME's left.
Anyway it is basically working ...
But before I spend some more time with that class I wanted to konw if it is=
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useful for your given problem and if it is really faster than what you have=
=20
now.
It is available from
ftp://ftp.uni-duisburg.de/FlightGear/Misc_maf/SGHTMMap-20060223

Let's see where that prooves useful ...
:)

BTW: I am leaving tomorrow morning for the FOSEM in Brussels. Anybody else=
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there?

    Greetings

          Mathias

=2D-=20
Mathias Fr=F6hlich, email: Mat...@gm...