Jody Garnett ha scritto:
> You are correct this technique would only show the maximum size; and
> use it to query. The style data structure is available so you can
> perform the calculations yourself (to see if which rules have been
> used).
> 
> There are a couple different approaches to selection in an interactive
> map; I mentioned one hack with respect to checking the pixels; a more
> involved technique involves rendering as a zbuffer; you would need to
> rewrite the renderer (or supply a hint) asking it to write down an
> integer for each feature drawn; and then check the raster at the end
> of the day to see what feature was "on top" in order to be clicked on.
> Not very much fun which is why I have not done it yet.

Actually, you can do that by rendering on top of a black and white
buffered image, and attach a rendering listener that checks pixels
after each rendered image, if the pixel in question is black, then
the feature has been clicked on. Then turn the pixel back to white
and allow the renderer to go to the next feature.
Never actually implemented this, but should be doable.

Cheers
Andrea


-- 
Andrea Aime
OpenGeo - http://opengeo.org
Expert service straight from the developers.

------------------------------------------------------------------------------
Crystal Reports - New Free Runtime and 30 Day Trial
Check out the new simplified licensign option that enables unlimited
royalty-free distribution of the report engine for externally facing 
server and web deployment.
http://p.sf.net/sfu/businessobjects
_______________________________________________
Geotools-gt2-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users

Reply via email to