Label Cache Performance

[Frank Warmerdam]

Steve Lime wrote:
> I did think of one other gotcha. The cache is not just used for physical
> overlap, there
> are other tests applied. For example, MINDISTANCE, which filters out
> like labels based
> on proximity. That requires direct comparison of the bounding polygons.
> One might be
> able to reduce that to a test on label points (in fact that might be
> what's there now,
> I'd have to check) but that still requires traversing placed labels
> (albeit only those
> within a particular layer)...

Steve(s),

Another approach that would address requirement is a spatial index
(ie. quadtree, or just a grid) which would make it easy to find all the
labels within a certain distance.

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo, http://osgeo.org