[OT] This feels wrong (pthreads question)

Steve smorrey at gmail.com
Mon Jan 29 15:48:45 MST 2007


By my reading of the STL container class deffinitions, I thought
std::map and std::multimap were rtrees.  Am I wrong in this?

On 1/29/07, Levi Pearson <levi at cold.org> wrote:
> Steve <smorrey at gmail.com> writes:
>
> > Almost forgot to mention that I'm  using an array of 3 "long long"s
> > to represent x,y,z.
> >
> > My multimap based SceneGraph is indexed by the entities position.x
> > Is there anything I need to be concerned with performance wise here?
> >
> > Thanks in advance!
>
> Did you miss the performance concern I mentioned just a little
> earlier?  A large cluster of objects with similar X coordinates and
> widely dispersed Y and/or Z coordinates will return a bunch of
> extraneous objects that you'll have to check Y and Z coordinates for.
>
> You really ought to consider R-trees, as there has been extensive
> reasearch on them and they are widely used in practice for just the
> kind of thing you're doing.
>
>                 --Levi
>
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