[OSM-talk] simplifying mapnik layout definition

Tom Hughes tom at compton.nu
Tue May 27 16:03:19 BST 2008


In message <20080527144058.GP2178 at mails.so.argh.org>
        Andreas Barth <aba at not.so.argh.org> wrote:

> The differences are only within the scales. So it would make sense to
> split the scales off - and make them as small as possible. The smaller
> it is, the easier one can make changes. So this could be written as:
>
> <Style name="tunnels-casing">
>       <Rules filter="([highway] = 'motorway' or [highway]='motorway_link') and ([tunnel] = 'yes' or [tunnel] ='true')"/>
>       <CssParameter name="stroke">#506077</CssParameter>
>       <CssParameter name="stroke-dasharray">4,2</CssParameter>
>       <ScaleDenominator max="200000" min="100000">
>         <CssParameter name="stroke-width">3</CssParameter>
>       </ScaleDenominator>
>       <ScaleDenominator max="100000" min="20000">
>         <CssParameter name="stroke-width">5.5</CssParameter>
>       </ScaleDenominator>
>     </Rules>
>
>
> This drops the (IMHO unnecessary) LineSymbolizer (one can make it up
> from the stuff around it) and emphasizes the differences. If this looks
> ok-ish, I could write an converter from the new to the old format as an
> starter.

That doesn't look valid to me though, as you aren't telling it
what symbolizer to use to draw the object. Have you actually checked
that mapnik accepts that syntax and does the right thing?

Tom

-- 
Tom Hughes (tom at compton.nu)
http://www.compton.nu/




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