[Tilesathome] Avoiding name duplications on dual carriageways

[Frederik Ramm]

Hi,

Knut Arne Bjørndal wrote:
> I've been thinking we may want to do real collision avoidance, or at
> least put what effort we spend on it into something that may one day
> do it properly.

> I think it makes sense to do that as a post-processor, yes it will
> have to handle some stuff like labels that are drawn in two rounds
> (core&casing-like), but that shouldn't be /too/ hard. This will allow
> it to be used where it's feasible to run perl (or whatever it ends up
> being written in), and it will be a reasonably separate component.

I think it's a bit ugly to make assumptions about font sizes. The SVG 
renderer is the one who decides how big a certain letter will be, 
depending on available fonts; even after we have generated our SVG 
output, the user could still fiddle with the font sizes in his editor. I 
view this as an advantage compared to the Mapnik-Cairo-SVG output which 
has all fonts rendered as paths and thus completely unchangeable.

Also, I don't even like total collision avoidance (like in Mapnik where 
it tends to drop the name of a road because there's a pub there or the 
other way round). If anything, it would have to be finely controllable 
(even "professional" maps allow text overlaps if the font sizes/colors 
are different enough for the eye to follow one or the other).

> Real collision avoidance in XSLT will probably never happen, and I'd
> love for this to be available to osmarender/xsl output as well.

Mmh... on a platform where Perl is readily available, one could just use 
or/p. And on a platform where one doesn't have Perl, a collision 
avoidance postprocessor written in Perl will not be of any use?

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"