[OSM-talk] Milestone

[Steve Chilton]

Andy

Have looked at the link on mapnik pages and can see real benefit in
defining colours once, and icon paths. Much of the layer
identification/specification stuff is ripe for enter once/repeat too.
Not so sure how splitting file into layers files would work in practice
- they would have to be continually merged to test render changes as far
as I can see, although if possible would make understanding and working
with the code possibly a lot easier.
How long are you going to be in Aberdeen for SoC conf? Maybe we could
put some time aside to work together on this (3 weeks holiday before
then so no spare time) - eg the Tuesday afternoon.
NB: my main requirement is less fiddling with colours and more adding
new features in AND getting them in the right relative place in the
painting/stacking process.

Cheers
STEVE

Steve Chilton, Learning Support Fellow
Manager of e-Learning Academic Development
Centre for Learning and Quality Enhancement
Middlesex University
phone/fax: 020 8411 5355
email: steve8 at mdx.ac.uk
http://www.mdx.ac.uk/schools/hssc/staff/profiles/technical/chiltons.asp

Chair of the Society of Cartographers: http://www.soc.org.uk/

SoC conference 2008:
http://www.abdn.ac.uk/cartographers08/
-----Original Message-----
From: Andy Allan [mailto:gravitystorm at gmail.com] 
Sent: 31 July 2008 18:09
To: Steve Chilton
Cc: talk at openstreetmap.org
Subject: Re: [OSM-talk] Milestone

On Mon, Jul 28, 2008 at 6:47 PM, Steve Chilton <S.L.Chilton at mdx.ac.uk>
wrote:

> So, if anyone feels like getting their hands dirty and doing some
collaborative work on mapnik style improvements then just drop me a
line.

I've spent quite a while making maps based on the osm.xml file - not
just the cycle map, but others too - and it's a bit of a pain* to
maintain a fork or even just use the main one as a base to work from.
I wonder if making this easier will build more of a community around
the mapnik stylesheet and therefore get more things fed back in.

So what does everyone think about raising the minimum requirements to
mapnik + libxml xmparser support**? For the basics, that would allow
defining all the colours in one place at the top of the file (and only
use each hex code once***). Most of what I've seen people wanting to
do is fiddle with the colours and it's currently pretty hard to do,
and a pain to keep in sync.

Beyond that, we could look at splitting layers into separate files,
again for ease of following changes since diffs of large repetitive
files can be erratic (and editing too, I would suspect, since I often
lose track of whether I'm in the middle of a roads-casing or
minor-roads-fill stylename).

Thoughts?

Andy

* Understatement
** http://trac.mapnik.org/wiki/ManagingLargeXmlFiles
*** for example: "grep '809bc0' osm.xml | wc -l" alone gives 30
recurrences