[OSM-talk] Merchandise

MP singularita at gmail.com
Sun Oct 25 23:02:07 GMT 2009


On 25/10/2009, Ævar Arnfjörð Bjarmason <avarab at gmail.com> wrote:
> On Sun, Oct 25, 2009 at 3:59 PM, MP <singularita at gmail.com> wrote:
>
> > Some java applet, that will download OSM XML. [...]
>
>  The problem is that if you want something that looks like the OSM maps
>  that's going to rely on a lot of things (mapnik et al) that aren't
>  Java programs, so it really can't viably run on someone's computer
>  without installing a lot of things.

Mapnik is good for displaying on screen, but for generating PDF and
printing it is better to generate vector-based, not image-based map.

Converting OSM XML to some set of vector commands (stored as PDF
operators) is not trivial considering number of map features and other
factors, but it can be done without any external dependencies - OSM
XML goes in, PDF with map goes out :)

Well, Java applet is one way, there are many another - like running
some PHP script, while having some PDF generating extensinon installed
on server.

>  Even if it were just an applet having to run an applet automatically
>  turns a lot of people away from the service.
>
>  It's not *that* computationally expensive to do this sort of thing anyway:)

No, not for generating once, but once people start requesting new
atlas every ten seconds in average and server needs over minute to
generate it, then you have trouble.

Martin




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