[Openstreetmap-dev] Recent improvements to the editing applet

SteveC steve at asklater.com
Sun Jan 1 22:20:01 GMT 2006


* @ 31/12/05 12:56:30 PM cjb at cjb.ie wrote:
> Hmmm. Would it be worthwhile moving some of the tile processing into the 
> applet? Given that at levels of zoom that are useful for editing, tiles 
> look like they're generated by magnifying and gaussian-blurring tiles 
> from lower levels of zoom - for higher zoom levels, could the applet 
> cache tiles from lower zoom levels, and magnify/blur those itself as 
> appropriate? This should cut down significantly on both CPU and 
> bandwidth usage on the server, and hopefully make the applet seem more 
> responsive too.
> 
> Feel free to shoot this idea down in flames if it's idiotic :)

In theory the applet could grab the points directly. It used to with the
old applet but there are two constraints. Firstly bandwidth, which you
can mitigate with gzip-encoding. The other is that an applet is allowed
some arbitrary small amount of memory and something I ran in to was
java.lang.OutOfMemoryException's with too many (eg a reasonable number)
of points in memory. Even as doubles in a simple array.

If someone knows the size allowances for code / data and whether these
are seperate and change between jvm's...

have fun,

SteveC steve at asklater.com http://www.asklater.com/steve/




More information about the dev mailing list